[PATCH v8 00/16] Linux RISC-V AIA Support

[PATCH v8 00/16] Linux RISC-V AIA Support

[Anup Patel]

The RISC-V AIA specification is now frozen as-per the RISC-V international
process. The latest frozen specifcation can be found at:
https://github.com/riscv/riscv-aia/releases/download/1.0/riscv-interrupts-1.0.pdf

At a high-level, the AIA specification adds three things:
1) AIA CSRs
   - Improved local interrupt support
2) Incoming Message Signaled Interrupt Controller (IMSIC)
   - Per-HART MSI controller
   - Support MSI virtualization
   - Support IPI along with virtualization
3) Advanced Platform-Level Interrupt Controller (APLIC)
   - Wired interrupt controller
   - In MSI-mode, converts wired interrupt into MSIs (i.e. MSI generator)
   - In Direct-mode, injects external interrupts directly into HARTs

For an overview of the AIA specification, refer the AIA virtualization
talk at KVM Forum 2022:
https://static.sched.com/hosted_files/kvmforum2022/a1/AIA_Virtualization_in_KVM_RISCV_final.pdf
https://www.youtube.com/watch?v=r071dL8Z0yo

To test this series, use QEMU v7.2 (or higher) and OpenSBI v1.2 (or higher).

These patches can also be found in the riscv_aia_v8 branch at:
https://github.com/avpatel/linux.git

Changes since v7:
 - Rebased on Linux-6.6-rc1
 - Addressed comments on PATCH1 of v7 series and split it into two PATCHes
 - Use DEFINE_SIMPLE_PROP() in PATCH2 of v7 series

Changes since v6:
 - Rebased on Linux-6.5-rc4
 - Updated PATCH2 to use IS_ENABLED(CONFIG_SPARC) instead of
   !IS_ENABLED(CONFIG_OF_IRQ)
 - Added new PATCH4 to fix syscore registration in PLIC driver
 - Update PATCH5 to convert PLIC driver into full-blown platform driver
   with a re-written probe function.

Changes since v5:
 - Rebased on Linux-6.5-rc2
 - Updated the overall series to ensure that only IPI, timer, and
   INTC drivers are probed very early whereas rest of the interrupt
   controllers (such as PLIC, APLIC, and IMISC) are probed as
   regular platform drivers.
 - Renamed riscv_fw_parent_hartid() to riscv_get_intc_hartid()
 - New PATCH1 to add fw_devlink support for msi-parent DT property
 - New PATCH2 to ensure all INTC suppliers are initialized which in-turn
   fixes the probing issue for PLIC, APLIC and IMSIC as platform driver
 - New PATCH3 to use platform driver probing for PLIC
 - Re-structured the IMSIC driver into two separate drivers: early and
   platform. The IMSIC early driver (PATCH7) only initialized IMSIC state
   and provides IPIs whereas the IMSIC platform driver (PATCH8) is probed
   provides MSI domain for platform devices.
 - Re-structure the APLIC platform driver into three separe sources: main,
   direct mode, and MSI mode.

Changes since v4:
 - Rebased on Linux-6.5-rc1
 - Added "Dependencies" in the APLIC bindings (PATCH6 in v4)
 - Dropped the PATCH6 which was changing the IOMMU DMA domain APIs
 - Dropped use of IOMMU DMA APIs in the IMSIC driver (PATCH4)

Changes since v3:
 - Rebased on Linux-6.4-rc6
 - Droped PATCH2 of v3 series instead we now set FWNODE_FLAG_BEST_EFFORT via
   IRQCHIP_DECLARE()
 - Extend riscv_fw_parent_hartid() to support both DT and ACPI in PATCH1
 - Extend iommu_dma_compose_msi_msg() instead of adding iommu_dma_select_msi()
   in PATCH6
 - Addressed Conor's comments in PATCH3
 - Addressed Conor's and Rob's comments in PATCH7

Changes since v2:
 - Rebased on Linux-6.4-rc1
 - Addressed Rob's comments on DT bindings patches 4 and 8.
 - Addessed Marc's comments on IMSIC driver PATCH5
 - Replaced use of OF apis in APLIC and IMSIC drivers with FWNODE apis
   this makes both drivers easily portable for ACPI support. This also
   removes unnecessary indirection from the APLIC and IMSIC drivers.
 - PATCH1 is a new patch for portability with ACPI support
 - PATCH2 is a new patch to fix probing in APLIC drivers for APLIC-only systems.
 - PATCH7 is a new patch which addresses the IOMMU DMA domain issues pointed
   out by SiFive

Changes since v1:
 - Rebased on Linux-6.2-rc2
 - Addressed comments on IMSIC DT bindings for PATCH4
 - Use raw_spin_lock_irqsave() on ids_lock for PATCH5
 - Improved MMIO alignment checks in PATCH5 to allow MMIO regions
   with holes.
 - Addressed comments on APLIC DT bindings for PATCH6
 - Fixed warning splat in aplic_msi_write_msg() caused by
   zeroed MSI message in PATCH7
 - Dropped DT property riscv,slow-ipi instead will have module
   parameter in future.

Anup Patel (16):
  RISC-V: Don't fail in riscv_of_parent_hartid() for disabled HARTs
  RISC-V: Add riscv_get_intc_hartid() function
  of: property: Add fw_devlink support for msi-parent
  drivers: irqchip/riscv-intc: Mark all INTC nodes as initialized
  irqchip/sifive-plic: Fix syscore registration for multi-socket systems
  irqchip/sifive-plic: Convert PLIC driver into a platform driver
  irqchip/riscv-intc: Add support for RISC-V AIA
  dt-bindings: interrupt-controller: Add RISC-V incoming MSI controller
  irqchip: Add RISC-V incoming MSI controller early driver
  irqchip/riscv-imsic: Add support for platform MSI irqdomain
  irqchip/riscv-imsic: Add support for PCI MSI irqdomain
  dt-bindings: interrupt-controller: Add RISC-V advanced PLIC
  irqchip: Add RISC-V advanced PLIC driver for direct-mode
  irqchip/riscv-aplic: Add support for MSI-mode
  RISC-V: Select APLIC and IMSIC drivers
  MAINTAINERS: Add entry for RISC-V AIA drivers

 .../interrupt-controller/riscv,aplic.yaml     | 172 ++++++
 .../interrupt-controller/riscv,imsics.yaml    | 172 ++++++
 MAINTAINERS                                   |  14 +
 arch/riscv/Kconfig                            |   2 +
 arch/riscv/include/asm/processor.h            |   4 +-
 arch/riscv/kernel/cpu.c                       |  24 +-
 drivers/irqchip/Kconfig                       |  25 +-
 drivers/irqchip/Makefile                      |   3 +
 drivers/irqchip/irq-riscv-aplic-direct.c      | 326 +++++++++++
 drivers/irqchip/irq-riscv-aplic-main.c        | 240 ++++++++
 drivers/irqchip/irq-riscv-aplic-main.h        |  53 ++
 drivers/irqchip/irq-riscv-aplic-msi.c         | 285 ++++++++++
 drivers/irqchip/irq-riscv-imsic-early.c       | 258 +++++++++
 drivers/irqchip/irq-riscv-imsic-platform.c    | 328 +++++++++++
 drivers/irqchip/irq-riscv-imsic-state.c       | 523 ++++++++++++++++++
 drivers/irqchip/irq-riscv-imsic-state.h       |  67 +++
 drivers/irqchip/irq-riscv-intc.c              |  46 +-
 drivers/irqchip/irq-sifive-plic.c             | 200 ++++---
 drivers/of/property.c                         |   2 +
 include/linux/irqchip/riscv-aplic.h           | 119 ++++
 include/linux/irqchip/riscv-imsic.h           |  86 +++
 21 files changed, 2847 insertions(+), 102 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/interrupt-controller/riscv,aplic.yaml
 create mode 100644 Documentation/devicetree/bindings/interrupt-controller/riscv,imsics.yaml
 create mode 100644 drivers/irqchip/irq-riscv-aplic-direct.c
 create mode 100644 drivers/irqchip/irq-riscv-aplic-main.c
 create mode 100644 drivers/irqchip/irq-riscv-aplic-main.h
 create mode 100644 drivers/irqchip/irq-riscv-aplic-msi.c
 create mode 100644 drivers/irqchip/irq-riscv-imsic-early.c
 create mode 100644 drivers/irqchip/irq-riscv-imsic-platform.c
 create mode 100644 drivers/irqchip/irq-riscv-imsic-state.c
 create mode 100644 drivers/irqchip/irq-riscv-imsic-state.h
 create mode 100644 include/linux/irqchip/riscv-aplic.h
 create mode 100644 include/linux/irqchip/riscv-imsic.h

-- 
2.34.1

[PATCH v8 00/16] Linux RISC-V AIA Support

[Anup Patel]

The RISC-V AIA specification is now frozen as-per the RISC-V international
process. The latest frozen specifcation can be found at:
https://github.com/riscv/riscv-aia/releases/download/1.0/riscv-interrupts-1.0.pdf

At a high-level, the AIA specification adds three things:
1) AIA CSRs
   - Improved local interrupt support
2) Incoming Message Signaled Interrupt Controller (IMSIC)
   - Per-HART MSI controller
   - Support MSI virtualization
   - Support IPI along with virtualization
3) Advanced Platform-Level Interrupt Controller (APLIC)
   - Wired interrupt controller
   - In MSI-mode, converts wired interrupt into MSIs (i.e. MSI generator)
   - In Direct-mode, injects external interrupts directly into HARTs

For an overview of the AIA specification, refer the AIA virtualization
talk at KVM Forum 2022:
https://static.sched.com/hosted_files/kvmforum2022/a1/AIA_Virtualization_in_KVM_RISCV_final.pdf
https://www.youtube.com/watch?v=r071dL8Z0yo

To test this series, use QEMU v7.2 (or higher) and OpenSBI v1.2 (or higher).

These patches can also be found in the riscv_aia_v8 branch at:
https://github.com/avpatel/linux.git

Changes since v7:
 - Rebased on Linux-6.6-rc1
 - Addressed comments on PATCH1 of v7 series and split it into two PATCHes
 - Use DEFINE_SIMPLE_PROP() in PATCH2 of v7 series

Changes since v6:
 - Rebased on Linux-6.5-rc4
 - Updated PATCH2 to use IS_ENABLED(CONFIG_SPARC) instead of
   !IS_ENABLED(CONFIG_OF_IRQ)
 - Added new PATCH4 to fix syscore registration in PLIC driver
 - Update PATCH5 to convert PLIC driver into full-blown platform driver
   with a re-written probe function.

Changes since v5:
 - Rebased on Linux-6.5-rc2
 - Updated the overall series to ensure that only IPI, timer, and
   INTC drivers are probed very early whereas rest of the interrupt
   controllers (such as PLIC, APLIC, and IMISC) are probed as
   regular platform drivers.
 - Renamed riscv_fw_parent_hartid() to riscv_get_intc_hartid()
 - New PATCH1 to add fw_devlink support for msi-parent DT property
 - New PATCH2 to ensure all INTC suppliers are initialized which in-turn
   fixes the probing issue for PLIC, APLIC and IMSIC as platform driver
 - New PATCH3 to use platform driver probing for PLIC
 - Re-structured the IMSIC driver into two separate drivers: early and
   platform. The IMSIC early driver (PATCH7) only initialized IMSIC state
   and provides IPIs whereas the IMSIC platform driver (PATCH8) is probed
   provides MSI domain for platform devices.
 - Re-structure the APLIC platform driver into three separe sources: main,
   direct mode, and MSI mode.

Changes since v4:
 - Rebased on Linux-6.5-rc1
 - Added "Dependencies" in the APLIC bindings (PATCH6 in v4)
 - Dropped the PATCH6 which was changing the IOMMU DMA domain APIs
 - Dropped use of IOMMU DMA APIs in the IMSIC driver (PATCH4)

Changes since v3:
 - Rebased on Linux-6.4-rc6
 - Droped PATCH2 of v3 series instead we now set FWNODE_FLAG_BEST_EFFORT via
   IRQCHIP_DECLARE()
 - Extend riscv_fw_parent_hartid() to support both DT and ACPI in PATCH1
 - Extend iommu_dma_compose_msi_msg() instead of adding iommu_dma_select_msi()
   in PATCH6
 - Addressed Conor's comments in PATCH3
 - Addressed Conor's and Rob's comments in PATCH7

Changes since v2:
 - Rebased on Linux-6.4-rc1
 - Addressed Rob's comments on DT bindings patches 4 and 8.
 - Addessed Marc's comments on IMSIC driver PATCH5
 - Replaced use of OF apis in APLIC and IMSIC drivers with FWNODE apis
   this makes both drivers easily portable for ACPI support. This also
   removes unnecessary indirection from the APLIC and IMSIC drivers.
 - PATCH1 is a new patch for portability with ACPI support
 - PATCH2 is a new patch to fix probing in APLIC drivers for APLIC-only systems.
 - PATCH7 is a new patch which addresses the IOMMU DMA domain issues pointed
   out by SiFive

Changes since v1:
 - Rebased on Linux-6.2-rc2
 - Addressed comments on IMSIC DT bindings for PATCH4
 - Use raw_spin_lock_irqsave() on ids_lock for PATCH5
 - Improved MMIO alignment checks in PATCH5 to allow MMIO regions
   with holes.
 - Addressed comments on APLIC DT bindings for PATCH6
 - Fixed warning splat in aplic_msi_write_msg() caused by
   zeroed MSI message in PATCH7
 - Dropped DT property riscv,slow-ipi instead will have module
   parameter in future.

Anup Patel (16):
  RISC-V: Don't fail in riscv_of_parent_hartid() for disabled HARTs
  RISC-V: Add riscv_get_intc_hartid() function
  of: property: Add fw_devlink support for msi-parent
  drivers: irqchip/riscv-intc: Mark all INTC nodes as initialized
  irqchip/sifive-plic: Fix syscore registration for multi-socket systems
  irqchip/sifive-plic: Convert PLIC driver into a platform driver
  irqchip/riscv-intc: Add support for RISC-V AIA
  dt-bindings: interrupt-controller: Add RISC-V incoming MSI controller
  irqchip: Add RISC-V incoming MSI controller early driver
  irqchip/riscv-imsic: Add support for platform MSI irqdomain
  irqchip/riscv-imsic: Add support for PCI MSI irqdomain
  dt-bindings: interrupt-controller: Add RISC-V advanced PLIC
  irqchip: Add RISC-V advanced PLIC driver for direct-mode
  irqchip/riscv-aplic: Add support for MSI-mode
  RISC-V: Select APLIC and IMSIC drivers
  MAINTAINERS: Add entry for RISC-V AIA drivers

 .../interrupt-controller/riscv,aplic.yaml     | 172 ++++++
 .../interrupt-controller/riscv,imsics.yaml    | 172 ++++++
 MAINTAINERS                                   |  14 +
 arch/riscv/Kconfig                            |   2 +
 arch/riscv/include/asm/processor.h            |   4 +-
 arch/riscv/kernel/cpu.c                       |  24 +-
 drivers/irqchip/Kconfig                       |  25 +-
 drivers/irqchip/Makefile                      |   3 +
 drivers/irqchip/irq-riscv-aplic-direct.c      | 326 +++++++++++
 drivers/irqchip/irq-riscv-aplic-main.c        | 240 ++++++++
 drivers/irqchip/irq-riscv-aplic-main.h        |  53 ++
 drivers/irqchip/irq-riscv-aplic-msi.c         | 285 ++++++++++
 drivers/irqchip/irq-riscv-imsic-early.c       | 258 +++++++++
 drivers/irqchip/irq-riscv-imsic-platform.c    | 328 +++++++++++
 drivers/irqchip/irq-riscv-imsic-state.c       | 523 ++++++++++++++++++
 drivers/irqchip/irq-riscv-imsic-state.h       |  67 +++
 drivers/irqchip/irq-riscv-intc.c              |  46 +-
 drivers/irqchip/irq-sifive-plic.c             | 200 ++++---
 drivers/of/property.c                         |   2 +
 include/linux/irqchip/riscv-aplic.h           | 119 ++++
 include/linux/irqchip/riscv-imsic.h           |  86 +++
 21 files changed, 2847 insertions(+), 102 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/interrupt-controller/riscv,aplic.yaml
 create mode 100644 Documentation/devicetree/bindings/interrupt-controller/riscv,imsics.yaml
 create mode 100644 drivers/irqchip/irq-riscv-aplic-direct.c
 create mode 100644 drivers/irqchip/irq-riscv-aplic-main.c
 create mode 100644 drivers/irqchip/irq-riscv-aplic-main.h
 create mode 100644 drivers/irqchip/irq-riscv-aplic-msi.c
 create mode 100644 drivers/irqchip/irq-riscv-imsic-early.c
 create mode 100644 drivers/irqchip/irq-riscv-imsic-platform.c
 create mode 100644 drivers/irqchip/irq-riscv-imsic-state.c
 create mode 100644 drivers/irqchip/irq-riscv-imsic-state.h
 create mode 100644 include/linux/irqchip/riscv-aplic.h
 create mode 100644 include/linux/irqchip/riscv-imsic.h

-- 
2.34.1


_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

[PATCH v8 01/16] RISC-V: Don't fail in riscv_of_parent_hartid() for disabled HARTs

[Anup Patel]

The riscv_of_processor_hartid() used by riscv_of_parent_hartid() fails
for HARTs disabled in the DT. This results in the following warning
thrown by the RISC-V INTC driver for the E-core on SiFive boards:

[    0.000000] riscv-intc: unable to find hart id for /cpus/cpu@0/interrupt-controller

The riscv_of_parent_hartid() is only expected to read the hartid from
the DT so we should directly call of_get_cpu_hwid() instead of calling
riscv_of_processor_hartid().

Fixes: ad635e723e17 ("riscv: cpu: Add 64bit hartid support on RV64")
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 arch/riscv/kernel/cpu.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index c17dacb1141c..157ace8b262c 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -125,13 +125,14 @@ int __init riscv_early_of_processor_hartid(struct device_node *node, unsigned lo
  */
 int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid)
 {
-	int rc;
-
 	for (; node; node = node->parent) {
 		if (of_device_is_compatible(node, "riscv")) {
-			rc = riscv_of_processor_hartid(node, hartid);
-			if (!rc)
-				return 0;
+			*hartid = (unsigned long)of_get_cpu_hwid(node, 0);
+			if (*hartid == ~0UL) {
+				pr_warn("Found CPU without hart ID\n");
+				return -ENODEV;
+			}
+			return 0;
 		}
 	}
 
-- 
2.34.1

[PATCH v8 01/16] RISC-V: Don't fail in riscv_of_parent_hartid() for disabled HARTs

[Anup Patel]

The riscv_of_processor_hartid() used by riscv_of_parent_hartid() fails
for HARTs disabled in the DT. This results in the following warning
thrown by the RISC-V INTC driver for the E-core on SiFive boards:

[    0.000000] riscv-intc: unable to find hart id for /cpus/cpu@0/interrupt-controller

The riscv_of_parent_hartid() is only expected to read the hartid from
the DT so we should directly call of_get_cpu_hwid() instead of calling
riscv_of_processor_hartid().

Fixes: ad635e723e17 ("riscv: cpu: Add 64bit hartid support on RV64")
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 arch/riscv/kernel/cpu.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index c17dacb1141c..157ace8b262c 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -125,13 +125,14 @@ int __init riscv_early_of_processor_hartid(struct device_node *node, unsigned lo
  */
 int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid)
 {
-	int rc;
-
 	for (; node; node = node->parent) {
 		if (of_device_is_compatible(node, "riscv")) {
-			rc = riscv_of_processor_hartid(node, hartid);
-			if (!rc)
-				return 0;
+			*hartid = (unsigned long)of_get_cpu_hwid(node, 0);
+			if (*hartid == ~0UL) {
+				pr_warn("Found CPU without hart ID\n");
+				return -ENODEV;
+			}
+			return 0;
 		}
 	}
 
-- 
2.34.1


_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

[PATCH v8 02/16] RISC-V: Add riscv_get_intc_hartid() function

[Anup Patel]

We add a common riscv_get_intc_hartid() which help device drivers to
get hartid of the HART associated with a INTC (i.e. local interrupt
controller) fwnode. This new function is more generic compared to
the existing riscv_of_parent_hartid() function hence we also replace
use of riscv_of_parent_hartid() with riscv_get_intc_hartid().

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 arch/riscv/include/asm/processor.h |  4 +++-
 arch/riscv/kernel/cpu.c            | 13 ++++++++++++-
 drivers/irqchip/irq-riscv-intc.c   |  2 +-
 drivers/irqchip/irq-sifive-plic.c  |  3 ++-
 4 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
index 3e23e1786d05..3ce64b3bea4e 100644
--- a/arch/riscv/include/asm/processor.h
+++ b/arch/riscv/include/asm/processor.h
@@ -119,7 +119,9 @@ static inline void wait_for_interrupt(void)
 struct device_node;
 int riscv_of_processor_hartid(struct device_node *node, unsigned long *hartid);
 int riscv_early_of_processor_hartid(struct device_node *node, unsigned long *hartid);
-int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid);
+
+struct fwnode_handle;
+int riscv_get_intc_hartid(struct fwnode_handle *node, unsigned long *hartid);
 
 extern void riscv_fill_hwcap(void);
 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index 157ace8b262c..ee583eac3c5b 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -123,7 +123,8 @@ int __init riscv_early_of_processor_hartid(struct device_node *node, unsigned lo
  * To achieve this, we walk up the DT tree until we find an active
  * RISC-V core (HART) node and extract the cpuid from it.
  */
-int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid)
+static int riscv_of_parent_hartid(struct device_node *node,
+				  unsigned long *hartid)
 {
 	for (; node; node = node->parent) {
 		if (of_device_is_compatible(node, "riscv")) {
@@ -139,6 +140,16 @@ int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid)
 	return -1;
 }
 
+/* Find hart ID of the INTC fwnode. */
+int riscv_get_intc_hartid(struct fwnode_handle *node, unsigned long *hartid)
+{
+	/* Extend this function ACPI in the future. */
+	if (!is_of_node(node))
+		return -ENODEV;
+
+	return riscv_of_parent_hartid(to_of_node(node), hartid);
+}
+
 DEFINE_PER_CPU(struct riscv_cpuinfo, riscv_cpuinfo);
 
 unsigned long riscv_cached_mvendorid(unsigned int cpu_id)
diff --git a/drivers/irqchip/irq-riscv-intc.c b/drivers/irqchip/irq-riscv-intc.c
index 4adeee1bc391..65f4a2afb381 100644
--- a/drivers/irqchip/irq-riscv-intc.c
+++ b/drivers/irqchip/irq-riscv-intc.c
@@ -143,7 +143,7 @@ static int __init riscv_intc_init(struct device_node *node,
 	int rc;
 	unsigned long hartid;
 
-	rc = riscv_of_parent_hartid(node, &hartid);
+	rc = riscv_get_intc_hartid(of_fwnode_handle(node), &hartid);
 	if (rc < 0) {
 		pr_warn("unable to find hart id for %pOF\n", node);
 		return 0;
diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
index e1484905b7bd..56b0544b1f27 100644
--- a/drivers/irqchip/irq-sifive-plic.c
+++ b/drivers/irqchip/irq-sifive-plic.c
@@ -477,7 +477,8 @@ static int __init __plic_init(struct device_node *node,
 			continue;
 		}
 
-		error = riscv_of_parent_hartid(parent.np, &hartid);
+		error = riscv_get_intc_hartid(of_fwnode_handle(parent.np),
+					      &hartid);
 		if (error < 0) {
 			pr_warn("failed to parse hart ID for context %d.\n", i);
 			continue;
-- 
2.34.1

[PATCH v8 02/16] RISC-V: Add riscv_get_intc_hartid() function

[Anup Patel]

We add a common riscv_get_intc_hartid() which help device drivers to
get hartid of the HART associated with a INTC (i.e. local interrupt
controller) fwnode. This new function is more generic compared to
the existing riscv_of_parent_hartid() function hence we also replace
use of riscv_of_parent_hartid() with riscv_get_intc_hartid().

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 arch/riscv/include/asm/processor.h |  4 +++-
 arch/riscv/kernel/cpu.c            | 13 ++++++++++++-
 drivers/irqchip/irq-riscv-intc.c   |  2 +-
 drivers/irqchip/irq-sifive-plic.c  |  3 ++-
 4 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
index 3e23e1786d05..3ce64b3bea4e 100644
--- a/arch/riscv/include/asm/processor.h
+++ b/arch/riscv/include/asm/processor.h
@@ -119,7 +119,9 @@ static inline void wait_for_interrupt(void)
 struct device_node;
 int riscv_of_processor_hartid(struct device_node *node, unsigned long *hartid);
 int riscv_early_of_processor_hartid(struct device_node *node, unsigned long *hartid);
-int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid);
+
+struct fwnode_handle;
+int riscv_get_intc_hartid(struct fwnode_handle *node, unsigned long *hartid);
 
 extern void riscv_fill_hwcap(void);
 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index 157ace8b262c..ee583eac3c5b 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -123,7 +123,8 @@ int __init riscv_early_of_processor_hartid(struct device_node *node, unsigned lo
  * To achieve this, we walk up the DT tree until we find an active
  * RISC-V core (HART) node and extract the cpuid from it.
  */
-int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid)
+static int riscv_of_parent_hartid(struct device_node *node,
+				  unsigned long *hartid)
 {
 	for (; node; node = node->parent) {
 		if (of_device_is_compatible(node, "riscv")) {
@@ -139,6 +140,16 @@ int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid)
 	return -1;
 }
 
+/* Find hart ID of the INTC fwnode. */
+int riscv_get_intc_hartid(struct fwnode_handle *node, unsigned long *hartid)
+{
+	/* Extend this function ACPI in the future. */
+	if (!is_of_node(node))
+		return -ENODEV;
+
+	return riscv_of_parent_hartid(to_of_node(node), hartid);
+}
+
 DEFINE_PER_CPU(struct riscv_cpuinfo, riscv_cpuinfo);
 
 unsigned long riscv_cached_mvendorid(unsigned int cpu_id)
diff --git a/drivers/irqchip/irq-riscv-intc.c b/drivers/irqchip/irq-riscv-intc.c
index 4adeee1bc391..65f4a2afb381 100644
--- a/drivers/irqchip/irq-riscv-intc.c
+++ b/drivers/irqchip/irq-riscv-intc.c
@@ -143,7 +143,7 @@ static int __init riscv_intc_init(struct device_node *node,
 	int rc;
 	unsigned long hartid;
 
-	rc = riscv_of_parent_hartid(node, &hartid);
+	rc = riscv_get_intc_hartid(of_fwnode_handle(node), &hartid);
 	if (rc < 0) {
 		pr_warn("unable to find hart id for %pOF\n", node);
 		return 0;
diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
index e1484905b7bd..56b0544b1f27 100644
--- a/drivers/irqchip/irq-sifive-plic.c
+++ b/drivers/irqchip/irq-sifive-plic.c
@@ -477,7 +477,8 @@ static int __init __plic_init(struct device_node *node,
 			continue;
 		}
 
-		error = riscv_of_parent_hartid(parent.np, &hartid);
+		error = riscv_get_intc_hartid(of_fwnode_handle(parent.np),
+					      &hartid);
 		if (error < 0) {
 			pr_warn("failed to parse hart ID for context %d.\n", i);
 			continue;
-- 
2.34.1


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[PATCH v8 03/16] of: property: Add fw_devlink support for msi-parent

[Anup Patel]

This allows fw_devlink to create device links between consumers of
a MSI and the supplier of the MSI.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 drivers/of/property.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/of/property.c b/drivers/of/property.c
index cf8dacf3e3b8..758ea822e46d 100644
--- a/drivers/of/property.c
+++ b/drivers/of/property.c
@@ -1267,6 +1267,7 @@ DEFINE_SIMPLE_PROP(resets, "resets", "#reset-cells")
 DEFINE_SIMPLE_PROP(leds, "leds", NULL)
 DEFINE_SIMPLE_PROP(backlight, "backlight", NULL)
 DEFINE_SIMPLE_PROP(panel, "panel", NULL)
+DEFINE_SIMPLE_PROP(msi_parent, "msi-parent", "#msi-cells")
 DEFINE_SUFFIX_PROP(regulators, "-supply", NULL)
 DEFINE_SUFFIX_PROP(gpio, "-gpio", "#gpio-cells")
 
@@ -1361,6 +1362,7 @@ static const struct supplier_bindings of_supplier_bindings[] = {
 	{ .parse_prop = parse_regulators, },
 	{ .parse_prop = parse_gpio, },
 	{ .parse_prop = parse_gpios, },
+	{ .parse_prop = parse_msi_parent, },
 	{}
 };
 
-- 
2.34.1

[PATCH v8 03/16] of: property: Add fw_devlink support for msi-parent

[Anup Patel]

This allows fw_devlink to create device links between consumers of
a MSI and the supplier of the MSI.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 drivers/of/property.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/of/property.c b/drivers/of/property.c
index cf8dacf3e3b8..758ea822e46d 100644
--- a/drivers/of/property.c
+++ b/drivers/of/property.c
@@ -1267,6 +1267,7 @@ DEFINE_SIMPLE_PROP(resets, "resets", "#reset-cells")
 DEFINE_SIMPLE_PROP(leds, "leds", NULL)
 DEFINE_SIMPLE_PROP(backlight, "backlight", NULL)
 DEFINE_SIMPLE_PROP(panel, "panel", NULL)
+DEFINE_SIMPLE_PROP(msi_parent, "msi-parent", "#msi-cells")
 DEFINE_SUFFIX_PROP(regulators, "-supply", NULL)
 DEFINE_SUFFIX_PROP(gpio, "-gpio", "#gpio-cells")
 
@@ -1361,6 +1362,7 @@ static const struct supplier_bindings of_supplier_bindings[] = {
 	{ .parse_prop = parse_regulators, },
 	{ .parse_prop = parse_gpio, },
 	{ .parse_prop = parse_gpios, },
+	{ .parse_prop = parse_msi_parent, },
 	{}
 };
 
-- 
2.34.1


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[PATCH v8 04/16] drivers: irqchip/riscv-intc: Mark all INTC nodes as initialized

[Anup Patel]

The RISC-V INTC local interrupts are per-HART (or per-CPU) so
we create INTC IRQ domain only for the INTC node belonging to
the boot HART. This means only the boot HART INTC node will be
marked as initialized and other INTC nodes won't be marked which
results downstream interrupt controllers (such as IMSIC and APLIC
direct-mode) not being probed due to missing device suppliers.

To address this issue, we mark all INTC node for which we don't
create IRQ domain as initialized.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 drivers/irqchip/irq-riscv-intc.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/irqchip/irq-riscv-intc.c b/drivers/irqchip/irq-riscv-intc.c
index 65f4a2afb381..4e2704bc25fb 100644
--- a/drivers/irqchip/irq-riscv-intc.c
+++ b/drivers/irqchip/irq-riscv-intc.c
@@ -155,8 +155,16 @@ static int __init riscv_intc_init(struct device_node *node,
 	 * for each INTC DT node. We only need to do INTC initialization
 	 * for the INTC DT node belonging to boot CPU (or boot HART).
 	 */
-	if (riscv_hartid_to_cpuid(hartid) != smp_processor_id())
+	if (riscv_hartid_to_cpuid(hartid) != smp_processor_id()) {
+		/*
+		 * The INTC nodes of each CPU are suppliers for downstream
+		 * interrupt controllers (such as IMSIC and APLIC direct-mode)
+		 * so we should mark an INTC node as initialized if we are
+		 * not creating IRQ domain for it.
+		 */
+		fwnode_dev_initialized(of_fwnode_handle(node), true);
 		return 0;
+	}
 
 	return riscv_intc_init_common(of_node_to_fwnode(node));
 }
-- 
2.34.1

[PATCH v8 04/16] drivers: irqchip/riscv-intc: Mark all INTC nodes as initialized

[Anup Patel]

The RISC-V INTC local interrupts are per-HART (or per-CPU) so
we create INTC IRQ domain only for the INTC node belonging to
the boot HART. This means only the boot HART INTC node will be
marked as initialized and other INTC nodes won't be marked which
results downstream interrupt controllers (such as IMSIC and APLIC
direct-mode) not being probed due to missing device suppliers.

To address this issue, we mark all INTC node for which we don't
create IRQ domain as initialized.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 drivers/irqchip/irq-riscv-intc.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/irqchip/irq-riscv-intc.c b/drivers/irqchip/irq-riscv-intc.c
index 65f4a2afb381..4e2704bc25fb 100644
--- a/drivers/irqchip/irq-riscv-intc.c
+++ b/drivers/irqchip/irq-riscv-intc.c
@@ -155,8 +155,16 @@ static int __init riscv_intc_init(struct device_node *node,
 	 * for each INTC DT node. We only need to do INTC initialization
 	 * for the INTC DT node belonging to boot CPU (or boot HART).
 	 */
-	if (riscv_hartid_to_cpuid(hartid) != smp_processor_id())
+	if (riscv_hartid_to_cpuid(hartid) != smp_processor_id()) {
+		/*
+		 * The INTC nodes of each CPU are suppliers for downstream
+		 * interrupt controllers (such as IMSIC and APLIC direct-mode)
+		 * so we should mark an INTC node as initialized if we are
+		 * not creating IRQ domain for it.
+		 */
+		fwnode_dev_initialized(of_fwnode_handle(node), true);
 		return 0;
+	}
 
 	return riscv_intc_init_common(of_node_to_fwnode(node));
 }
-- 
2.34.1


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[PATCH v8 05/16] irqchip/sifive-plic: Fix syscore registration for multi-socket systems

[Anup Patel]

On multi-socket systems, we will have a separate PLIC in each socket
so we should register syscore operation only once for multi-socket
systems.

Fixes: e80f0b6a2cf3 ("irqchip/irq-sifive-plic: Add syscore callbacks for hibernation")
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 drivers/irqchip/irq-sifive-plic.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
index 56b0544b1f27..62ba27553cc3 100644
--- a/drivers/irqchip/irq-sifive-plic.c
+++ b/drivers/irqchip/irq-sifive-plic.c
@@ -533,17 +533,18 @@ static int __init __plic_init(struct device_node *node,
 	}
 
 	/*
-	 * We can have multiple PLIC instances so setup cpuhp state only
-	 * when context handler for current/boot CPU is present.
+	 * We can have multiple PLIC instances so setup cpuhp state
+	 * and register syscore operations only when context handler
+	 * for current/boot CPU is present.
 	 */
 	handler = this_cpu_ptr(&plic_handlers);
 	if (handler->present && !plic_cpuhp_setup_done) {
 		cpuhp_setup_state(CPUHP_AP_IRQ_SIFIVE_PLIC_STARTING,
 				  "irqchip/sifive/plic:starting",
 				  plic_starting_cpu, plic_dying_cpu);
+		register_syscore_ops(&plic_irq_syscore_ops);
 		plic_cpuhp_setup_done = true;
 	}
-	register_syscore_ops(&plic_irq_syscore_ops);
 
 	pr_info("%pOFP: mapped %d interrupts with %d handlers for"
 		" %d contexts.\n", node, nr_irqs, nr_handlers, nr_contexts);
-- 
2.34.1

[PATCH v8 05/16] irqchip/sifive-plic: Fix syscore registration for multi-socket systems

[Anup Patel]

On multi-socket systems, we will have a separate PLIC in each socket
so we should register syscore operation only once for multi-socket
systems.

Fixes: e80f0b6a2cf3 ("irqchip/irq-sifive-plic: Add syscore callbacks for hibernation")
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 drivers/irqchip/irq-sifive-plic.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
index 56b0544b1f27..62ba27553cc3 100644
--- a/drivers/irqchip/irq-sifive-plic.c
+++ b/drivers/irqchip/irq-sifive-plic.c
@@ -533,17 +533,18 @@ static int __init __plic_init(struct device_node *node,
 	}
 
 	/*
-	 * We can have multiple PLIC instances so setup cpuhp state only
-	 * when context handler for current/boot CPU is present.
+	 * We can have multiple PLIC instances so setup cpuhp state
+	 * and register syscore operations only when context handler
+	 * for current/boot CPU is present.
 	 */
 	handler = this_cpu_ptr(&plic_handlers);
 	if (handler->present && !plic_cpuhp_setup_done) {
 		cpuhp_setup_state(CPUHP_AP_IRQ_SIFIVE_PLIC_STARTING,
 				  "irqchip/sifive/plic:starting",
 				  plic_starting_cpu, plic_dying_cpu);
+		register_syscore_ops(&plic_irq_syscore_ops);
 		plic_cpuhp_setup_done = true;
 	}
-	register_syscore_ops(&plic_irq_syscore_ops);
 
 	pr_info("%pOFP: mapped %d interrupts with %d handlers for"
 		" %d contexts.\n", node, nr_irqs, nr_handlers, nr_contexts);
-- 
2.34.1


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[PATCH v8 06/16] irqchip/sifive-plic: Convert PLIC driver into a platform driver

[Anup Patel]

The PLIC driver does not require very early initialization so let us
convert it into a platform driver.

As part of the conversion, the PLIC probing undergoes the following
changes:
1. Use dev_info(), dev_err() and dev_warn() instead of pr_info(),
   pr_err() and pr_warn()
2. Use devm_xyz() APIs wherever applicable
3. Use fwnode APIs to read PLIC properties so that PLIC driver
   is suitable for ACPI as well.
4. PLIC is now probed after CPUs are brought-up so we have to
   setup cpuhp state after context handler of all online CPUs
   are initialized otherwise we see crash on multi-socket systems

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 drivers/irqchip/irq-sifive-plic.c | 198 +++++++++++++++++-------------
 1 file changed, 112 insertions(+), 86 deletions(-)

diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
index 62ba27553cc3..72d6e06ef52b 100644
--- a/drivers/irqchip/irq-sifive-plic.c
+++ b/drivers/irqchip/irq-sifive-plic.c
@@ -3,7 +3,6 @@
  * Copyright (C) 2017 SiFive
  * Copyright (C) 2018 Christoph Hellwig
  */
-#define pr_fmt(fmt) "plic: " fmt
 #include <linux/cpu.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
@@ -13,8 +12,6 @@
 #include <linux/irqdomain.h>
 #include <linux/module.h>
 #include <linux/of.h>
-#include <linux/of_address.h>
-#include <linux/of_irq.h>
 #include <linux/platform_device.h>
 #include <linux/spinlock.h>
 #include <linux/syscore_ops.h>
@@ -64,6 +61,7 @@
 #define PLIC_QUIRK_EDGE_INTERRUPT	0
 
 struct plic_priv {
+	struct device *dev;
 	struct cpumask lmask;
 	struct irq_domain *irqdomain;
 	void __iomem *regs;
@@ -85,7 +83,6 @@ struct plic_handler {
 	struct plic_priv	*priv;
 };
 static int plic_parent_irq __ro_after_init;
-static bool plic_cpuhp_setup_done __ro_after_init;
 static DEFINE_PER_CPU(struct plic_handler, plic_handlers);
 
 static int plic_irq_set_type(struct irq_data *d, unsigned int type);
@@ -371,7 +368,8 @@ static void plic_handle_irq(struct irq_desc *desc)
 		int err = generic_handle_domain_irq(handler->priv->irqdomain,
 						    hwirq);
 		if (unlikely(err))
-			pr_warn_ratelimited("can't find mapping for hwirq %lu\n",
+			dev_warn_ratelimited(handler->priv->dev,
+					"can't find mapping for hwirq %lu\n",
 					hwirq);
 	}
 
@@ -406,57 +404,83 @@ static int plic_starting_cpu(unsigned int cpu)
 	return 0;
 }
 
-static int __init __plic_init(struct device_node *node,
-			      struct device_node *parent,
-			      unsigned long plic_quirks)
+static const struct of_device_id plic_match[] = {
+	{ .compatible = "sifive,plic-1.0.0" },
+	{ .compatible = "riscv,plic0" },
+	{ .compatible = "andestech,nceplic100",
+	  .data = (const void *)BIT(PLIC_QUIRK_EDGE_INTERRUPT) },
+	{ .compatible = "thead,c900-plic",
+	  .data = (const void *)BIT(PLIC_QUIRK_EDGE_INTERRUPT) },
+	{}
+};
+
+static int plic_probe(struct platform_device *pdev)
 {
-	int error = 0, nr_contexts, nr_handlers = 0, i;
-	u32 nr_irqs;
-	struct plic_priv *priv;
+	int rc, nr_contexts, nr_handlers = 0, i, cpu;
+	unsigned long plic_quirks = 0, hartid;
+	struct fwnode_reference_args parent;
+	struct device *dev = &pdev->dev;
 	struct plic_handler *handler;
-	unsigned int cpu;
+	struct irq_domain *domain;
+	struct plic_priv *priv;
+	irq_hw_number_t hwirq;
+	struct resource *res;
+	bool cpuhp_setup;
+	u32 nr_irqs;
+
+	if (is_of_node(dev->fwnode)) {
+		const struct of_device_id *id;
+
+		id = of_match_node(plic_match, to_of_node(dev->fwnode));
+		if (id)
+			plic_quirks = (unsigned long)id->data;
+	}
 
-	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;
-
+	priv->dev = dev;
 	priv->plic_quirks = plic_quirks;
 
-	priv->regs = of_iomap(node, 0);
-	if (WARN_ON(!priv->regs)) {
-		error = -EIO;
-		goto out_free_priv;
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "failed to get MMIO resource\n");
+		return -EINVAL;
+	}
+	priv->regs = devm_ioremap(dev, res->start, resource_size(res));
+	if (!priv->regs) {
+		dev_err(dev, "failed map MMIO registers\n");
+		return -EIO;
 	}
 
-	error = -EINVAL;
-	of_property_read_u32(node, "riscv,ndev", &nr_irqs);
-	if (WARN_ON(!nr_irqs))
-		goto out_iounmap;
-
+	rc = fwnode_property_read_u32_array(dev->fwnode, "riscv,ndev",
+						&nr_irqs, 1);
+	if (rc) {
+		dev_err(dev, "riscv,ndev property not available\n");
+		return rc;
+	}
 	priv->nr_irqs = nr_irqs;
 
-	priv->prio_save = bitmap_alloc(nr_irqs, GFP_KERNEL);
+	priv->prio_save = devm_bitmap_zalloc(dev, nr_irqs, GFP_KERNEL);
 	if (!priv->prio_save)
-		goto out_free_priority_reg;
-
-	nr_contexts = of_irq_count(node);
-	if (WARN_ON(!nr_contexts))
-		goto out_free_priority_reg;
+		return -ENOMEM;
 
-	error = -ENOMEM;
-	priv->irqdomain = irq_domain_add_linear(node, nr_irqs + 1,
-			&plic_irqdomain_ops, priv);
-	if (WARN_ON(!priv->irqdomain))
-		goto out_free_priority_reg;
+	nr_contexts = 0;
+	while (!fwnode_property_get_reference_args(dev->fwnode,
+				"interrupts-extended", "#interrupt-cells",
+				0, nr_contexts, &parent))
+		nr_contexts++;
+	if (WARN_ON(!nr_contexts)) {
+		dev_err(dev, "no PLIC context available\n");
+		return -EINVAL;
+	}
 
 	for (i = 0; i < nr_contexts; i++) {
-		struct of_phandle_args parent;
-		irq_hw_number_t hwirq;
-		int cpu;
-		unsigned long hartid;
-
-		if (of_irq_parse_one(node, i, &parent)) {
-			pr_err("failed to parse parent for context %d.\n", i);
+		rc = fwnode_property_get_reference_args(dev->fwnode,
+				"interrupts-extended", "#interrupt-cells",
+				0, i, &parent);
+		if (rc) {
+			dev_warn(dev, "parent irq for context%d not found\n", i);
 			continue;
 		}
 
@@ -477,22 +501,23 @@ static int __init __plic_init(struct device_node *node,
 			continue;
 		}
 
-		error = riscv_get_intc_hartid(of_fwnode_handle(parent.np),
-					      &hartid);
-		if (error < 0) {
-			pr_warn("failed to parse hart ID for context %d.\n", i);
+		rc = riscv_get_intc_hartid(parent.fwnode, &hartid);
+		if (rc < 0) {
+			dev_warn(dev, "failed to get hart ID for context%d.\n", i);
 			continue;
 		}
 
 		cpu = riscv_hartid_to_cpuid(hartid);
 		if (cpu < 0) {
-			pr_warn("Invalid cpuid for context %d\n", i);
+			dev_warn(dev, "Invalid cpuid for context %d\n", i);
 			continue;
 		}
 
 		/* Find parent domain and register chained handler */
-		if (!plic_parent_irq && irq_find_host(parent.np)) {
-			plic_parent_irq = irq_of_parse_and_map(node, i);
+		domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
+						  DOMAIN_BUS_ANY);
+		if (!plic_parent_irq && domain) {
+			plic_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT);
 			if (plic_parent_irq)
 				irq_set_chained_handler(plic_parent_irq,
 							plic_handle_irq);
@@ -505,7 +530,7 @@ static int __init __plic_init(struct device_node *node,
 		 */
 		handler = per_cpu_ptr(&plic_handlers, cpu);
 		if (handler->present) {
-			pr_warn("handler already present for context %d.\n", i);
+			dev_warn(dev, "handler already present for context%d.\n", i);
 			plic_set_threshold(handler, PLIC_DISABLE_THRESHOLD);
 			goto done;
 		}
@@ -519,10 +544,13 @@ static int __init __plic_init(struct device_node *node,
 			i * CONTEXT_ENABLE_SIZE;
 		handler->priv = priv;
 
-		handler->enable_save =  kcalloc(DIV_ROUND_UP(nr_irqs, 32),
-						sizeof(*handler->enable_save), GFP_KERNEL);
+		handler->enable_save =  devm_kcalloc(dev,
+						DIV_ROUND_UP(nr_irqs, 32),
+						sizeof(*handler->enable_save),
+						GFP_KERNEL);
 		if (!handler->enable_save)
-			goto out_free_enable_reg;
+			return -ENOMEM;
+
 done:
 		for (hwirq = 1; hwirq <= nr_irqs; hwirq++) {
 			plic_toggle(handler, hwirq, 0);
@@ -532,52 +560,50 @@ static int __init __plic_init(struct device_node *node,
 		nr_handlers++;
 	}
 
+	priv->irqdomain = irq_domain_create_linear(dev->fwnode, nr_irqs + 1,
+						   &plic_irqdomain_ops, priv);
+	if (WARN_ON(!priv->irqdomain))
+		return -ENOMEM;
+
 	/*
 	 * We can have multiple PLIC instances so setup cpuhp state
-	 * and register syscore operations only when context handler
-	 * for current/boot CPU is present.
+	 * and register syscore operations only after context handlers
+	 * of all online CPUs are initialized.
 	 */
-	handler = this_cpu_ptr(&plic_handlers);
-	if (handler->present && !plic_cpuhp_setup_done) {
+	cpuhp_setup = true;
+	for_each_online_cpu(cpu) {
+		handler = per_cpu_ptr(&plic_handlers, cpu);
+		if (!handler->present) {
+			cpuhp_setup = false;
+			break;
+		}
+	}
+	if (cpuhp_setup) {
 		cpuhp_setup_state(CPUHP_AP_IRQ_SIFIVE_PLIC_STARTING,
 				  "irqchip/sifive/plic:starting",
 				  plic_starting_cpu, plic_dying_cpu);
 		register_syscore_ops(&plic_irq_syscore_ops);
-		plic_cpuhp_setup_done = true;
 	}
 
-	pr_info("%pOFP: mapped %d interrupts with %d handlers for"
-		" %d contexts.\n", node, nr_irqs, nr_handlers, nr_contexts);
+	dev_info(dev, "mapped %d interrupts with %d handlers for"
+		" %d contexts.\n", nr_irqs, nr_handlers, nr_contexts);
 	return 0;
-
-out_free_enable_reg:
-	for_each_cpu(cpu, cpu_present_mask) {
-		handler = per_cpu_ptr(&plic_handlers, cpu);
-		kfree(handler->enable_save);
-	}
-out_free_priority_reg:
-	kfree(priv->prio_save);
-out_iounmap:
-	iounmap(priv->regs);
-out_free_priv:
-	kfree(priv);
-	return error;
-}
-
-static int __init plic_init(struct device_node *node,
-			    struct device_node *parent)
-{
-	return __plic_init(node, parent, 0);
 }
 
-IRQCHIP_DECLARE(sifive_plic, "sifive,plic-1.0.0", plic_init);
-IRQCHIP_DECLARE(riscv_plic0, "riscv,plic0", plic_init); /* for legacy systems */
+static struct platform_driver plic_driver = {
+	.driver = {
+		.name		= "riscv-plic",
+		.of_match_table	= plic_match,
+	},
+	.probe = plic_probe,
+};
 
-static int __init plic_edge_init(struct device_node *node,
-				 struct device_node *parent)
+static int __init plic_init(void)
 {
-	return __plic_init(node, parent, BIT(PLIC_QUIRK_EDGE_INTERRUPT));
+	/*
+	 * Register PLIC driver as early as possible so that PLIC
+	 * platform device is probed as soon as it is created.
+	 */
+	return platform_driver_register(&plic_driver);
 }
-
-IRQCHIP_DECLARE(andestech_nceplic100, "andestech,nceplic100", plic_edge_init);
-IRQCHIP_DECLARE(thead_c900_plic, "thead,c900-plic", plic_edge_init);
+core_initcall(plic_init);
-- 
2.34.1

[PATCH v8 06/16] irqchip/sifive-plic: Convert PLIC driver into a platform driver

[Anup Patel]

The PLIC driver does not require very early initialization so let us
convert it into a platform driver.

As part of the conversion, the PLIC probing undergoes the following
changes:
1. Use dev_info(), dev_err() and dev_warn() instead of pr_info(),
   pr_err() and pr_warn()
2. Use devm_xyz() APIs wherever applicable
3. Use fwnode APIs to read PLIC properties so that PLIC driver
   is suitable for ACPI as well.
4. PLIC is now probed after CPUs are brought-up so we have to
   setup cpuhp state after context handler of all online CPUs
   are initialized otherwise we see crash on multi-socket systems

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 drivers/irqchip/irq-sifive-plic.c | 198 +++++++++++++++++-------------
 1 file changed, 112 insertions(+), 86 deletions(-)

diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
index 62ba27553cc3..72d6e06ef52b 100644
--- a/drivers/irqchip/irq-sifive-plic.c
+++ b/drivers/irqchip/irq-sifive-plic.c
@@ -3,7 +3,6 @@
  * Copyright (C) 2017 SiFive
  * Copyright (C) 2018 Christoph Hellwig
  */
-#define pr_fmt(fmt) "plic: " fmt
 #include <linux/cpu.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
@@ -13,8 +12,6 @@
 #include <linux/irqdomain.h>
 #include <linux/module.h>
 #include <linux/of.h>
-#include <linux/of_address.h>
-#include <linux/of_irq.h>
 #include <linux/platform_device.h>
 #include <linux/spinlock.h>
 #include <linux/syscore_ops.h>
@@ -64,6 +61,7 @@
 #define PLIC_QUIRK_EDGE_INTERRUPT	0
 
 struct plic_priv {
+	struct device *dev;
 	struct cpumask lmask;
 	struct irq_domain *irqdomain;
 	void __iomem *regs;
@@ -85,7 +83,6 @@ struct plic_handler {
 	struct plic_priv	*priv;
 };
 static int plic_parent_irq __ro_after_init;
-static bool plic_cpuhp_setup_done __ro_after_init;
 static DEFINE_PER_CPU(struct plic_handler, plic_handlers);
 
 static int plic_irq_set_type(struct irq_data *d, unsigned int type);
@@ -371,7 +368,8 @@ static void plic_handle_irq(struct irq_desc *desc)
 		int err = generic_handle_domain_irq(handler->priv->irqdomain,
 						    hwirq);
 		if (unlikely(err))
-			pr_warn_ratelimited("can't find mapping for hwirq %lu\n",
+			dev_warn_ratelimited(handler->priv->dev,
+					"can't find mapping for hwirq %lu\n",
 					hwirq);
 	}
 
@@ -406,57 +404,83 @@ static int plic_starting_cpu(unsigned int cpu)
 	return 0;
 }
 
-static int __init __plic_init(struct device_node *node,
-			      struct device_node *parent,
-			      unsigned long plic_quirks)
+static const struct of_device_id plic_match[] = {
+	{ .compatible = "sifive,plic-1.0.0" },
+	{ .compatible = "riscv,plic0" },
+	{ .compatible = "andestech,nceplic100",
+	  .data = (const void *)BIT(PLIC_QUIRK_EDGE_INTERRUPT) },
+	{ .compatible = "thead,c900-plic",
+	  .data = (const void *)BIT(PLIC_QUIRK_EDGE_INTERRUPT) },
+	{}
+};
+
+static int plic_probe(struct platform_device *pdev)
 {
-	int error = 0, nr_contexts, nr_handlers = 0, i;
-	u32 nr_irqs;
-	struct plic_priv *priv;
+	int rc, nr_contexts, nr_handlers = 0, i, cpu;
+	unsigned long plic_quirks = 0, hartid;
+	struct fwnode_reference_args parent;
+	struct device *dev = &pdev->dev;
 	struct plic_handler *handler;
-	unsigned int cpu;
+	struct irq_domain *domain;
+	struct plic_priv *priv;
+	irq_hw_number_t hwirq;
+	struct resource *res;
+	bool cpuhp_setup;
+	u32 nr_irqs;
+
+	if (is_of_node(dev->fwnode)) {
+		const struct of_device_id *id;
+
+		id = of_match_node(plic_match, to_of_node(dev->fwnode));
+		if (id)
+			plic_quirks = (unsigned long)id->data;
+	}
 
-	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;
-
+	priv->dev = dev;
 	priv->plic_quirks = plic_quirks;
 
-	priv->regs = of_iomap(node, 0);
-	if (WARN_ON(!priv->regs)) {
-		error = -EIO;
-		goto out_free_priv;
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "failed to get MMIO resource\n");
+		return -EINVAL;
+	}
+	priv->regs = devm_ioremap(dev, res->start, resource_size(res));
+	if (!priv->regs) {
+		dev_err(dev, "failed map MMIO registers\n");
+		return -EIO;
 	}
 
-	error = -EINVAL;
-	of_property_read_u32(node, "riscv,ndev", &nr_irqs);
-	if (WARN_ON(!nr_irqs))
-		goto out_iounmap;
-
+	rc = fwnode_property_read_u32_array(dev->fwnode, "riscv,ndev",
+						&nr_irqs, 1);
+	if (rc) {
+		dev_err(dev, "riscv,ndev property not available\n");
+		return rc;
+	}
 	priv->nr_irqs = nr_irqs;
 
-	priv->prio_save = bitmap_alloc(nr_irqs, GFP_KERNEL);
+	priv->prio_save = devm_bitmap_zalloc(dev, nr_irqs, GFP_KERNEL);
 	if (!priv->prio_save)
-		goto out_free_priority_reg;
-
-	nr_contexts = of_irq_count(node);
-	if (WARN_ON(!nr_contexts))
-		goto out_free_priority_reg;
+		return -ENOMEM;
 
-	error = -ENOMEM;
-	priv->irqdomain = irq_domain_add_linear(node, nr_irqs + 1,
-			&plic_irqdomain_ops, priv);
-	if (WARN_ON(!priv->irqdomain))
-		goto out_free_priority_reg;
+	nr_contexts = 0;
+	while (!fwnode_property_get_reference_args(dev->fwnode,
+				"interrupts-extended", "#interrupt-cells",
+				0, nr_contexts, &parent))
+		nr_contexts++;
+	if (WARN_ON(!nr_contexts)) {
+		dev_err(dev, "no PLIC context available\n");
+		return -EINVAL;
+	}
 
 	for (i = 0; i < nr_contexts; i++) {
-		struct of_phandle_args parent;
-		irq_hw_number_t hwirq;
-		int cpu;
-		unsigned long hartid;
-
-		if (of_irq_parse_one(node, i, &parent)) {
-			pr_err("failed to parse parent for context %d.\n", i);
+		rc = fwnode_property_get_reference_args(dev->fwnode,
+				"interrupts-extended", "#interrupt-cells",
+				0, i, &parent);
+		if (rc) {
+			dev_warn(dev, "parent irq for context%d not found\n", i);
 			continue;
 		}
 
@@ -477,22 +501,23 @@ static int __init __plic_init(struct device_node *node,
 			continue;
 		}
 
-		error = riscv_get_intc_hartid(of_fwnode_handle(parent.np),
-					      &hartid);
-		if (error < 0) {
-			pr_warn("failed to parse hart ID for context %d.\n", i);
+		rc = riscv_get_intc_hartid(parent.fwnode, &hartid);
+		if (rc < 0) {
+			dev_warn(dev, "failed to get hart ID for context%d.\n", i);
 			continue;
 		}
 
 		cpu = riscv_hartid_to_cpuid(hartid);
 		if (cpu < 0) {
-			pr_warn("Invalid cpuid for context %d\n", i);
+			dev_warn(dev, "Invalid cpuid for context %d\n", i);
 			continue;
 		}
 
 		/* Find parent domain and register chained handler */
-		if (!plic_parent_irq && irq_find_host(parent.np)) {
-			plic_parent_irq = irq_of_parse_and_map(node, i);
+		domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
+						  DOMAIN_BUS_ANY);
+		if (!plic_parent_irq && domain) {
+			plic_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT);
 			if (plic_parent_irq)
 				irq_set_chained_handler(plic_parent_irq,
 							plic_handle_irq);
@@ -505,7 +530,7 @@ static int __init __plic_init(struct device_node *node,
 		 */
 		handler = per_cpu_ptr(&plic_handlers, cpu);
 		if (handler->present) {
-			pr_warn("handler already present for context %d.\n", i);
+			dev_warn(dev, "handler already present for context%d.\n", i);
 			plic_set_threshold(handler, PLIC_DISABLE_THRESHOLD);
 			goto done;
 		}
@@ -519,10 +544,13 @@ static int __init __plic_init(struct device_node *node,
 			i * CONTEXT_ENABLE_SIZE;
 		handler->priv = priv;
 
-		handler->enable_save =  kcalloc(DIV_ROUND_UP(nr_irqs, 32),
-						sizeof(*handler->enable_save), GFP_KERNEL);
+		handler->enable_save =  devm_kcalloc(dev,
+						DIV_ROUND_UP(nr_irqs, 32),
+						sizeof(*handler->enable_save),
+						GFP_KERNEL);
 		if (!handler->enable_save)
-			goto out_free_enable_reg;
+			return -ENOMEM;
+
 done:
 		for (hwirq = 1; hwirq <= nr_irqs; hwirq++) {
 			plic_toggle(handler, hwirq, 0);
@@ -532,52 +560,50 @@ static int __init __plic_init(struct device_node *node,
 		nr_handlers++;
 	}
 
+	priv->irqdomain = irq_domain_create_linear(dev->fwnode, nr_irqs + 1,
+						   &plic_irqdomain_ops, priv);
+	if (WARN_ON(!priv->irqdomain))
+		return -ENOMEM;
+
 	/*
 	 * We can have multiple PLIC instances so setup cpuhp state
-	 * and register syscore operations only when context handler
-	 * for current/boot CPU is present.
+	 * and register syscore operations only after context handlers
+	 * of all online CPUs are initialized.
 	 */
-	handler = this_cpu_ptr(&plic_handlers);
-	if (handler->present && !plic_cpuhp_setup_done) {
+	cpuhp_setup = true;
+	for_each_online_cpu(cpu) {
+		handler = per_cpu_ptr(&plic_handlers, cpu);
+		if (!handler->present) {
+			cpuhp_setup = false;
+			break;
+		}
+	}
+	if (cpuhp_setup) {
 		cpuhp_setup_state(CPUHP_AP_IRQ_SIFIVE_PLIC_STARTING,
 				  "irqchip/sifive/plic:starting",
 				  plic_starting_cpu, plic_dying_cpu);
 		register_syscore_ops(&plic_irq_syscore_ops);
-		plic_cpuhp_setup_done = true;
 	}
 
-	pr_info("%pOFP: mapped %d interrupts with %d handlers for"
-		" %d contexts.\n", node, nr_irqs, nr_handlers, nr_contexts);
+	dev_info(dev, "mapped %d interrupts with %d handlers for"
+		" %d contexts.\n", nr_irqs, nr_handlers, nr_contexts);
 	return 0;
-
-out_free_enable_reg:
-	for_each_cpu(cpu, cpu_present_mask) {
-		handler = per_cpu_ptr(&plic_handlers, cpu);
-		kfree(handler->enable_save);
-	}
-out_free_priority_reg:
-	kfree(priv->prio_save);
-out_iounmap:
-	iounmap(priv->regs);
-out_free_priv:
-	kfree(priv);
-	return error;
-}
-
-static int __init plic_init(struct device_node *node,
-			    struct device_node *parent)
-{
-	return __plic_init(node, parent, 0);
 }
 
-IRQCHIP_DECLARE(sifive_plic, "sifive,plic-1.0.0", plic_init);
-IRQCHIP_DECLARE(riscv_plic0, "riscv,plic0", plic_init); /* for legacy systems */
+static struct platform_driver plic_driver = {
+	.driver = {
+		.name		= "riscv-plic",
+		.of_match_table	= plic_match,
+	},
+	.probe = plic_probe,
+};
 
-static int __init plic_edge_init(struct device_node *node,
-				 struct device_node *parent)
+static int __init plic_init(void)
 {
-	return __plic_init(node, parent, BIT(PLIC_QUIRK_EDGE_INTERRUPT));
+	/*
+	 * Register PLIC driver as early as possible so that PLIC
+	 * platform device is probed as soon as it is created.
+	 */
+	return platform_driver_register(&plic_driver);
 }
-
-IRQCHIP_DECLARE(andestech_nceplic100, "andestech,nceplic100", plic_edge_init);
-IRQCHIP_DECLARE(thead_c900_plic, "thead,c900-plic", plic_edge_init);
+core_initcall(plic_init);
-- 
2.34.1


_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

[PATCH v8 07/16] irqchip/riscv-intc: Add support for RISC-V AIA

[Anup Patel]

The RISC-V advanced interrupt architecture (AIA) extends the per-HART
local interrupts in following ways:
1. Minimum 64 local interrupts for both RV32 and RV64
2. Ability to process multiple pending local interrupts in same
   interrupt handler
3. Priority configuration for each local interrupts
4. Special CSRs to configure/access the per-HART MSI controller

We add support for #1 and #2 described above in the RISC-V intc driver.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 drivers/irqchip/irq-riscv-intc.c | 34 ++++++++++++++++++++++++++------
 1 file changed, 28 insertions(+), 6 deletions(-)

diff --git a/drivers/irqchip/irq-riscv-intc.c b/drivers/irqchip/irq-riscv-intc.c
index 4e2704bc25fb..1a0fc87152c5 100644
--- a/drivers/irqchip/irq-riscv-intc.c
+++ b/drivers/irqchip/irq-riscv-intc.c
@@ -17,6 +17,7 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/smp.h>
+#include <asm/hwcap.h>
 
 static struct irq_domain *intc_domain;
 
@@ -30,6 +31,15 @@ static asmlinkage void riscv_intc_irq(struct pt_regs *regs)
 	generic_handle_domain_irq(intc_domain, cause);
 }
 
+static asmlinkage void riscv_intc_aia_irq(struct pt_regs *regs)
+{
+	unsigned long topi;
+
+	while ((topi = csr_read(CSR_TOPI)))
+		generic_handle_domain_irq(intc_domain,
+					  topi >> TOPI_IID_SHIFT);
+}
+
 /*
  * On RISC-V systems local interrupts are masked or unmasked by writing
  * the SIE (Supervisor Interrupt Enable) CSR.  As CSRs can only be written
@@ -39,12 +49,18 @@ static asmlinkage void riscv_intc_irq(struct pt_regs *regs)
 
 static void riscv_intc_irq_mask(struct irq_data *d)
 {
-	csr_clear(CSR_IE, BIT(d->hwirq));
+	if (IS_ENABLED(CONFIG_32BIT) && d->hwirq >= BITS_PER_LONG)
+		csr_clear(CSR_IEH, BIT(d->hwirq - BITS_PER_LONG));
+	else
+		csr_clear(CSR_IE, BIT(d->hwirq));
 }
 
 static void riscv_intc_irq_unmask(struct irq_data *d)
 {
-	csr_set(CSR_IE, BIT(d->hwirq));
+	if (IS_ENABLED(CONFIG_32BIT) && d->hwirq >= BITS_PER_LONG)
+		csr_set(CSR_IEH, BIT(d->hwirq - BITS_PER_LONG));
+	else
+		csr_set(CSR_IE, BIT(d->hwirq));
 }
 
 static void riscv_intc_irq_eoi(struct irq_data *d)
@@ -115,16 +131,20 @@ static struct fwnode_handle *riscv_intc_hwnode(void)
 
 static int __init riscv_intc_init_common(struct fwnode_handle *fn)
 {
-	int rc;
+	int rc, nr_irqs = riscv_isa_extension_available(NULL, SxAIA) ?
+			  64 : BITS_PER_LONG;
 
-	intc_domain = irq_domain_create_linear(fn, BITS_PER_LONG,
+	intc_domain = irq_domain_create_linear(fn, nr_irqs,
 					       &riscv_intc_domain_ops, NULL);
 	if (!intc_domain) {
 		pr_err("unable to add IRQ domain\n");
 		return -ENXIO;
 	}
 
-	rc = set_handle_irq(&riscv_intc_irq);
+	if (riscv_isa_extension_available(NULL, SxAIA))
+		rc = set_handle_irq(&riscv_intc_aia_irq);
+	else
+		rc = set_handle_irq(&riscv_intc_irq);
 	if (rc) {
 		pr_err("failed to set irq handler\n");
 		return rc;
@@ -132,7 +152,9 @@ static int __init riscv_intc_init_common(struct fwnode_handle *fn)
 
 	riscv_set_intc_hwnode_fn(riscv_intc_hwnode);
 
-	pr_info("%d local interrupts mapped\n", BITS_PER_LONG);
+	pr_info("%d local interrupts mapped%s\n",
+		nr_irqs, riscv_isa_extension_available(NULL, SxAIA) ?
+			 " using AIA" : "");
 
 	return 0;
 }
-- 
2.34.1

[PATCH v8 07/16] irqchip/riscv-intc: Add support for RISC-V AIA

[Anup Patel]

The RISC-V advanced interrupt architecture (AIA) extends the per-HART
local interrupts in following ways:
1. Minimum 64 local interrupts for both RV32 and RV64
2. Ability to process multiple pending local interrupts in same
   interrupt handler
3. Priority configuration for each local interrupts
4. Special CSRs to configure/access the per-HART MSI controller

We add support for #1 and #2 described above in the RISC-V intc driver.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 drivers/irqchip/irq-riscv-intc.c | 34 ++++++++++++++++++++++++++------
 1 file changed, 28 insertions(+), 6 deletions(-)

diff --git a/drivers/irqchip/irq-riscv-intc.c b/drivers/irqchip/irq-riscv-intc.c
index 4e2704bc25fb..1a0fc87152c5 100644
--- a/drivers/irqchip/irq-riscv-intc.c
+++ b/drivers/irqchip/irq-riscv-intc.c
@@ -17,6 +17,7 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/smp.h>
+#include <asm/hwcap.h>
 
 static struct irq_domain *intc_domain;
 
@@ -30,6 +31,15 @@ static asmlinkage void riscv_intc_irq(struct pt_regs *regs)
 	generic_handle_domain_irq(intc_domain, cause);
 }
 
+static asmlinkage void riscv_intc_aia_irq(struct pt_regs *regs)
+{
+	unsigned long topi;
+
+	while ((topi = csr_read(CSR_TOPI)))
+		generic_handle_domain_irq(intc_domain,
+					  topi >> TOPI_IID_SHIFT);
+}
+
 /*
  * On RISC-V systems local interrupts are masked or unmasked by writing
  * the SIE (Supervisor Interrupt Enable) CSR.  As CSRs can only be written
@@ -39,12 +49,18 @@ static asmlinkage void riscv_intc_irq(struct pt_regs *regs)
 
 static void riscv_intc_irq_mask(struct irq_data *d)
 {
-	csr_clear(CSR_IE, BIT(d->hwirq));
+	if (IS_ENABLED(CONFIG_32BIT) && d->hwirq >= BITS_PER_LONG)
+		csr_clear(CSR_IEH, BIT(d->hwirq - BITS_PER_LONG));
+	else
+		csr_clear(CSR_IE, BIT(d->hwirq));
 }
 
 static void riscv_intc_irq_unmask(struct irq_data *d)
 {
-	csr_set(CSR_IE, BIT(d->hwirq));
+	if (IS_ENABLED(CONFIG_32BIT) && d->hwirq >= BITS_PER_LONG)
+		csr_set(CSR_IEH, BIT(d->hwirq - BITS_PER_LONG));
+	else
+		csr_set(CSR_IE, BIT(d->hwirq));
 }
 
 static void riscv_intc_irq_eoi(struct irq_data *d)
@@ -115,16 +131,20 @@ static struct fwnode_handle *riscv_intc_hwnode(void)
 
 static int __init riscv_intc_init_common(struct fwnode_handle *fn)
 {
-	int rc;
+	int rc, nr_irqs = riscv_isa_extension_available(NULL, SxAIA) ?
+			  64 : BITS_PER_LONG;
 
-	intc_domain = irq_domain_create_linear(fn, BITS_PER_LONG,
+	intc_domain = irq_domain_create_linear(fn, nr_irqs,
 					       &riscv_intc_domain_ops, NULL);
 	if (!intc_domain) {
 		pr_err("unable to add IRQ domain\n");
 		return -ENXIO;
 	}
 
-	rc = set_handle_irq(&riscv_intc_irq);
+	if (riscv_isa_extension_available(NULL, SxAIA))
+		rc = set_handle_irq(&riscv_intc_aia_irq);
+	else
+		rc = set_handle_irq(&riscv_intc_irq);
 	if (rc) {
 		pr_err("failed to set irq handler\n");
 		return rc;
@@ -132,7 +152,9 @@ static int __init riscv_intc_init_common(struct fwnode_handle *fn)
 
 	riscv_set_intc_hwnode_fn(riscv_intc_hwnode);
 
-	pr_info("%d local interrupts mapped\n", BITS_PER_LONG);
+	pr_info("%d local interrupts mapped%s\n",
+		nr_irqs, riscv_isa_extension_available(NULL, SxAIA) ?
+			 " using AIA" : "");
 
 	return 0;
 }
-- 
2.34.1


_______________________________________________
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[PATCH v8 08/16] dt-bindings: interrupt-controller: Add RISC-V incoming MSI controller

[Anup Patel]

We add DT bindings document for the RISC-V incoming MSI controller
(IMSIC) defined by the RISC-V advanced interrupt architecture (AIA)
specification.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
 .../interrupt-controller/riscv,imsics.yaml    | 172 ++++++++++++++++++
 1 file changed, 172 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/interrupt-controller/riscv,imsics.yaml

diff --git a/Documentation/devicetree/bindings/interrupt-controller/riscv,imsics.yaml b/Documentation/devicetree/bindings/interrupt-controller/riscv,imsics.yaml
new file mode 100644
index 000000000000..84976f17a4a1
--- /dev/null
+++ b/Documentation/devicetree/bindings/interrupt-controller/riscv,imsics.yaml
@@ -0,0 +1,172 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/interrupt-controller/riscv,imsics.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: RISC-V Incoming MSI Controller (IMSIC)
+
+maintainers:
+  - Anup Patel <anup@brainfault.org>
+
+description: |
+  The RISC-V advanced interrupt architecture (AIA) defines a per-CPU incoming
+  MSI controller (IMSIC) for handling MSIs in a RISC-V platform. The RISC-V
+  AIA specification can be found at https://github.com/riscv/riscv-aia.
+
+  The IMSIC is a per-CPU (or per-HART) device with separate interrupt file
+  for each privilege level (machine or supervisor). The configuration of
+  a IMSIC interrupt file is done using AIA CSRs and it also has a 4KB MMIO
+  space to receive MSIs from devices. Each IMSIC interrupt file supports a
+  fixed number of interrupt identities (to distinguish MSIs from devices)
+  which is same for given privilege level across CPUs (or HARTs).
+
+  The device tree of a RISC-V platform will have one IMSIC device tree node
+  for each privilege level (machine or supervisor) which collectively describe
+  IMSIC interrupt files at that privilege level across CPUs (or HARTs).
+
+  The arrangement of IMSIC interrupt files in MMIO space of a RISC-V platform
+  follows a particular scheme defined by the RISC-V AIA specification. A IMSIC
+  group is a set of IMSIC interrupt files co-located in MMIO space and we can
+  have multiple IMSIC groups (i.e. clusters, sockets, chiplets, etc) in a
+  RISC-V platform. The MSI target address of a IMSIC interrupt file at given
+  privilege level (machine or supervisor) encodes group index, HART index,
+  and guest index (shown below).
+
+  XLEN-1            > (HART Index MSB)                  12    0
+  |                  |                                  |     |
+  -------------------------------------------------------------
+  |xxxxxx|Group Index|xxxxxxxxxxx|HART Index|Guest Index|  0  |
+  -------------------------------------------------------------
+
+allOf:
+  - $ref: /schemas/interrupt-controller.yaml#
+  - $ref: /schemas/interrupt-controller/msi-controller.yaml#
+
+properties:
+  compatible:
+    items:
+      - enum:
+          - qemu,imsics
+      - const: riscv,imsics
+
+  reg:
+    minItems: 1
+    maxItems: 16384
+    description:
+      Base address of each IMSIC group.
+
+  interrupt-controller: true
+
+  "#interrupt-cells":
+    const: 0
+
+  msi-controller: true
+
+  "#msi-cells":
+    const: 0
+
+  interrupts-extended:
+    minItems: 1
+    maxItems: 16384
+    description:
+      This property represents the set of CPUs (or HARTs) for which given
+      device tree node describes the IMSIC interrupt files. Each node pointed
+      to should be a riscv,cpu-intc node, which has a CPU node (i.e. RISC-V
+      HART) as parent.
+
+  riscv,num-ids:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 63
+    maximum: 2047
+    description:
+      Number of interrupt identities supported by IMSIC interrupt file.
+
+  riscv,num-guest-ids:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 63
+    maximum: 2047
+    description:
+      Number of interrupt identities are supported by IMSIC guest interrupt
+      file. When not specified it is assumed to be same as specified by the
+      riscv,num-ids property.
+
+  riscv,guest-index-bits:
+    minimum: 0
+    maximum: 7
+    default: 0
+    description:
+      Number of guest index bits in the MSI target address.
+
+  riscv,hart-index-bits:
+    minimum: 0
+    maximum: 15
+    description:
+      Number of HART index bits in the MSI target address. When not
+      specified it is calculated based on the interrupts-extended property.
+
+  riscv,group-index-bits:
+    minimum: 0
+    maximum: 7
+    default: 0
+    description:
+      Number of group index bits in the MSI target address.
+
+  riscv,group-index-shift:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 0
+    maximum: 55
+    default: 24
+    description:
+      The least significant bit position of the group index bits in the
+      MSI target address.
+
+required:
+  - compatible
+  - reg
+  - interrupt-controller
+  - msi-controller
+  - "#msi-cells"
+  - interrupts-extended
+  - riscv,num-ids
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    // Example 1 (Machine-level IMSIC files with just one group):
+
+    interrupt-controller@24000000 {
+      compatible = "qemu,imsics", "riscv,imsics";
+      interrupts-extended = <&cpu1_intc 11>,
+                            <&cpu2_intc 11>,
+                            <&cpu3_intc 11>,
+                            <&cpu4_intc 11>;
+      reg = <0x28000000 0x4000>;
+      interrupt-controller;
+      #interrupt-cells = <0>;
+      msi-controller;
+      #msi-cells = <0>;
+      riscv,num-ids = <127>;
+    };
+
+  - |
+    // Example 2 (Supervisor-level IMSIC files with two groups):
+
+    interrupt-controller@28000000 {
+      compatible = "qemu,imsics", "riscv,imsics";
+      interrupts-extended = <&cpu1_intc 9>,
+                            <&cpu2_intc 9>,
+                            <&cpu3_intc 9>,
+                            <&cpu4_intc 9>;
+      reg = <0x28000000 0x2000>, /* Group0 IMSICs */
+            <0x29000000 0x2000>; /* Group1 IMSICs */
+      interrupt-controller;
+      #interrupt-cells = <0>;
+      msi-controller;
+      #msi-cells = <0>;
+      riscv,num-ids = <127>;
+      riscv,group-index-bits = <1>;
+      riscv,group-index-shift = <24>;
+    };
+...
-- 
2.34.1


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[PATCH v8 08/16] dt-bindings: interrupt-controller: Add RISC-V incoming MSI controller

[Anup Patel]

We add DT bindings document for the RISC-V incoming MSI controller
(IMSIC) defined by the RISC-V advanced interrupt architecture (AIA)
specification.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
 .../interrupt-controller/riscv,imsics.yaml    | 172 ++++++++++++++++++
 1 file changed, 172 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/interrupt-controller/riscv,imsics.yaml

diff --git a/Documentation/devicetree/bindings/interrupt-controller/riscv,imsics.yaml b/Documentation/devicetree/bindings/interrupt-controller/riscv,imsics.yaml
new file mode 100644
index 000000000000..84976f17a4a1
--- /dev/null
+++ b/Documentation/devicetree/bindings/interrupt-controller/riscv,imsics.yaml
@@ -0,0 +1,172 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/interrupt-controller/riscv,imsics.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: RISC-V Incoming MSI Controller (IMSIC)
+
+maintainers:
+  - Anup Patel <anup@brainfault.org>
+
+description: |
+  The RISC-V advanced interrupt architecture (AIA) defines a per-CPU incoming
+  MSI controller (IMSIC) for handling MSIs in a RISC-V platform. The RISC-V
+  AIA specification can be found at https://github.com/riscv/riscv-aia.
+
+  The IMSIC is a per-CPU (or per-HART) device with separate interrupt file
+  for each privilege level (machine or supervisor). The configuration of
+  a IMSIC interrupt file is done using AIA CSRs and it also has a 4KB MMIO
+  space to receive MSIs from devices. Each IMSIC interrupt file supports a
+  fixed number of interrupt identities (to distinguish MSIs from devices)
+  which is same for given privilege level across CPUs (or HARTs).
+
+  The device tree of a RISC-V platform will have one IMSIC device tree node
+  for each privilege level (machine or supervisor) which collectively describe
+  IMSIC interrupt files at that privilege level across CPUs (or HARTs).
+
+  The arrangement of IMSIC interrupt files in MMIO space of a RISC-V platform
+  follows a particular scheme defined by the RISC-V AIA specification. A IMSIC
+  group is a set of IMSIC interrupt files co-located in MMIO space and we can
+  have multiple IMSIC groups (i.e. clusters, sockets, chiplets, etc) in a
+  RISC-V platform. The MSI target address of a IMSIC interrupt file at given
+  privilege level (machine or supervisor) encodes group index, HART index,
+  and guest index (shown below).
+
+  XLEN-1            > (HART Index MSB)                  12    0
+  |                  |                                  |     |
+  -------------------------------------------------------------
+  |xxxxxx|Group Index|xxxxxxxxxxx|HART Index|Guest Index|  0  |
+  -------------------------------------------------------------
+
+allOf:
+  - $ref: /schemas/interrupt-controller.yaml#
+  - $ref: /schemas/interrupt-controller/msi-controller.yaml#
+
+properties:
+  compatible:
+    items:
+      - enum:
+          - qemu,imsics
+      - const: riscv,imsics
+
+  reg:
+    minItems: 1
+    maxItems: 16384
+    description:
+      Base address of each IMSIC group.
+
+  interrupt-controller: true
+
+  "#interrupt-cells":
+    const: 0
+
+  msi-controller: true
+
+  "#msi-cells":
+    const: 0
+
+  interrupts-extended:
+    minItems: 1
+    maxItems: 16384
+    description:
+      This property represents the set of CPUs (or HARTs) for which given
+      device tree node describes the IMSIC interrupt files. Each node pointed
+      to should be a riscv,cpu-intc node, which has a CPU node (i.e. RISC-V
+      HART) as parent.
+
+  riscv,num-ids:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 63
+    maximum: 2047
+    description:
+      Number of interrupt identities supported by IMSIC interrupt file.
+
+  riscv,num-guest-ids:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 63
+    maximum: 2047
+    description:
+      Number of interrupt identities are supported by IMSIC guest interrupt
+      file. When not specified it is assumed to be same as specified by the
+      riscv,num-ids property.
+
+  riscv,guest-index-bits:
+    minimum: 0
+    maximum: 7
+    default: 0
+    description:
+      Number of guest index bits in the MSI target address.
+
+  riscv,hart-index-bits:
+    minimum: 0
+    maximum: 15
+    description:
+      Number of HART index bits in the MSI target address. When not
+      specified it is calculated based on the interrupts-extended property.
+
+  riscv,group-index-bits:
+    minimum: 0
+    maximum: 7
+    default: 0
+    description:
+      Number of group index bits in the MSI target address.
+
+  riscv,group-index-shift:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 0
+    maximum: 55
+    default: 24
+    description:
+      The least significant bit position of the group index bits in the
+      MSI target address.
+
+required:
+  - compatible
+  - reg
+  - interrupt-controller
+  - msi-controller
+  - "#msi-cells"
+  - interrupts-extended
+  - riscv,num-ids
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    // Example 1 (Machine-level IMSIC files with just one group):
+
+    interrupt-controller@24000000 {
+      compatible = "qemu,imsics", "riscv,imsics";
+      interrupts-extended = <&cpu1_intc 11>,
+                            <&cpu2_intc 11>,
+                            <&cpu3_intc 11>,
+                            <&cpu4_intc 11>;
+      reg = <0x28000000 0x4000>;
+      interrupt-controller;
+      #interrupt-cells = <0>;
+      msi-controller;
+      #msi-cells = <0>;
+      riscv,num-ids = <127>;
+    };
+
+  - |
+    // Example 2 (Supervisor-level IMSIC files with two groups):
+
+    interrupt-controller@28000000 {
+      compatible = "qemu,imsics", "riscv,imsics";
+      interrupts-extended = <&cpu1_intc 9>,
+                            <&cpu2_intc 9>,
+                            <&cpu3_intc 9>,
+                            <&cpu4_intc 9>;
+      reg = <0x28000000 0x2000>, /* Group0 IMSICs */
+            <0x29000000 0x2000>; /* Group1 IMSICs */
+      interrupt-controller;
+      #interrupt-cells = <0>;
+      msi-controller;
+      #msi-cells = <0>;
+      riscv,num-ids = <127>;
+      riscv,group-index-bits = <1>;
+      riscv,group-index-shift = <24>;
+    };
+...
-- 
2.34.1

[PATCH v8 09/16] irqchip: Add RISC-V incoming MSI controller early driver

[Anup Patel]

The RISC-V advanced interrupt architecture (AIA) specification
defines a new MSI controller called incoming message signalled
interrupt controller (IMSIC) which manages MSI on per-HART (or
per-CPU) basis. It also supports IPIs as software injected MSIs.
(For more details refer https://github.com/riscv/riscv-aia)

Let us add an early irqchip driver for RISC-V IMSIC which sets
up the IMSIC state and provide IPIs.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 drivers/irqchip/Kconfig                 |   7 +-
 drivers/irqchip/Makefile                |   1 +
 drivers/irqchip/irq-riscv-imsic-early.c | 258 ++++++++++++
 drivers/irqchip/irq-riscv-imsic-state.c | 523 ++++++++++++++++++++++++
 drivers/irqchip/irq-riscv-imsic-state.h |  66 +++
 include/linux/irqchip/riscv-imsic.h     |  86 ++++
 6 files changed, 940 insertions(+), 1 deletion(-)
 create mode 100644 drivers/irqchip/irq-riscv-imsic-early.c
 create mode 100644 drivers/irqchip/irq-riscv-imsic-state.c
 create mode 100644 drivers/irqchip/irq-riscv-imsic-state.h
 create mode 100644 include/linux/irqchip/riscv-imsic.h

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index f7149d0f3d45..ee99aacbefcc 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -30,7 +30,6 @@ config ARM_GIC_V2M
 
 config GIC_NON_BANKED
 	bool
-
 config ARM_GIC_V3
 	bool
 	select IRQ_DOMAIN_HIERARCHY
@@ -546,6 +545,12 @@ config SIFIVE_PLIC
 	select IRQ_DOMAIN_HIERARCHY
 	select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
 
+config RISCV_IMSIC
+	bool
+	depends on RISCV
+	select IRQ_DOMAIN_HIERARCHY
+	select GENERIC_MSI_IRQ
+
 config EXYNOS_IRQ_COMBINER
 	bool "Samsung Exynos IRQ combiner support" if COMPILE_TEST
 	depends on (ARCH_EXYNOS && ARM) || COMPILE_TEST
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index ffd945fe71aa..d714724387ce 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -95,6 +95,7 @@ obj-$(CONFIG_QCOM_MPM)			+= irq-qcom-mpm.o
 obj-$(CONFIG_CSKY_MPINTC)		+= irq-csky-mpintc.o
 obj-$(CONFIG_CSKY_APB_INTC)		+= irq-csky-apb-intc.o
 obj-$(CONFIG_RISCV_INTC)		+= irq-riscv-intc.o
+obj-$(CONFIG_RISCV_IMSIC)		+= irq-riscv-imsic-state.o irq-riscv-imsic-early.o
 obj-$(CONFIG_SIFIVE_PLIC)		+= irq-sifive-plic.o
 obj-$(CONFIG_IMX_IRQSTEER)		+= irq-imx-irqsteer.o
 obj-$(CONFIG_IMX_INTMUX)		+= irq-imx-intmux.o
diff --git a/drivers/irqchip/irq-riscv-imsic-early.c b/drivers/irqchip/irq-riscv-imsic-early.c
new file mode 100644
index 000000000000..1de89ce1ec2f
--- /dev/null
+++ b/drivers/irqchip/irq-riscv-imsic-early.c
@@ -0,0 +1,258 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+
+#define pr_fmt(fmt) "riscv-imsic: " fmt
+#include <linux/cpu.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/smp.h>
+
+#include "irq-riscv-imsic-state.h"
+
+/*
+ * The IMSIC driver uses 1 IPI for ID synchronization and
+ * arch/riscv/kernel/smp.c require 6 IPIs so we fix the
+ * total number of IPIs to 8.
+ */
+#define IMSIC_NR_IPI				8
+
+static int imsic_parent_irq;
+
+#ifdef CONFIG_SMP
+static irqreturn_t imsic_ids_sync_handler(int irq, void *data)
+{
+	imsic_ids_local_sync();
+	return IRQ_HANDLED;
+}
+
+void imsic_ids_remote_sync(void)
+{
+	struct cpumask amask;
+
+	/*
+	 * We simply inject ID synchronization IPI to all target CPUs
+	 * except current CPU. The ipi_send_mask() implementation of
+	 * IPI mux will inject ID synchronization IPI only for CPUs
+	 * that have enabled it so offline CPUs won't receive IPI.
+	 * An offline CPU will unconditionally synchronize IDs through
+	 * imsic_starting_cpu() when the CPU is brought up.
+	 */
+	cpumask_andnot(&amask, cpu_online_mask, cpumask_of(smp_processor_id()));
+	__ipi_send_mask(imsic->ipi_lsync_desc, &amask);
+}
+
+static void imsic_ipi_send(unsigned int cpu)
+{
+	struct imsic_local_config *local =
+				per_cpu_ptr(imsic->global.local, cpu);
+
+	writel(imsic->ipi_id, local->msi_va);
+}
+
+static void imsic_ipi_starting_cpu(void)
+{
+	/* Enable IPIs for current CPU. */
+	__imsic_id_enable(imsic->ipi_id);
+
+	/* Enable virtual IPI used for IMSIC ID synchronization */
+	enable_percpu_irq(imsic->ipi_virq, 0);
+}
+
+static void imsic_ipi_dying_cpu(void)
+{
+	/*
+	 * Disable virtual IPI used for IMSIC ID synchronization so
+	 * that we don't receive ID synchronization requests.
+	 */
+	disable_percpu_irq(imsic->ipi_virq);
+}
+
+static int __init imsic_ipi_domain_init(void)
+{
+	int virq;
+
+	/* Allocate interrupt identity for IPIs */
+	virq = imsic_ids_alloc(get_count_order(1));
+	if (virq < 0)
+		return virq;
+	imsic->ipi_id = virq;
+
+	/* Create IMSIC IPI multiplexing */
+	virq = ipi_mux_create(IMSIC_NR_IPI, imsic_ipi_send);
+	if (virq <= 0) {
+		imsic_ids_free(imsic->ipi_id, get_count_order(1));
+		return (virq < 0) ? virq : -ENOMEM;
+	}
+	imsic->ipi_virq = virq;
+
+	/* First vIRQ is used for IMSIC ID synchronization */
+	virq = request_percpu_irq(imsic->ipi_virq, imsic_ids_sync_handler,
+				  "riscv-imsic-lsync", imsic->global.local);
+	if (virq) {
+		imsic_ids_free(imsic->ipi_id, get_count_order(1));
+		return virq;
+	}
+	irq_set_status_flags(imsic->ipi_virq, IRQ_HIDDEN);
+	imsic->ipi_lsync_desc = irq_to_desc(imsic->ipi_virq);
+
+	/* Set vIRQ range */
+	riscv_ipi_set_virq_range(imsic->ipi_virq + 1, IMSIC_NR_IPI - 1, true);
+
+	/* Announce that IMSIC is providing IPIs */
+	pr_info("%pfwP: providing IPIs using interrupt %d\n",
+		imsic->fwnode, imsic->ipi_id);
+
+	return 0;
+}
+#else
+static void imsic_ipi_starting_cpu(void)
+{
+}
+
+static void imsic_ipi_dying_cpu(void)
+{
+}
+
+static int __init imsic_ipi_domain_init(void)
+{
+	/* Clear the IPI id because we are not using IPIs */
+	imsic->ipi_id = 0;
+	return 0;
+}
+#endif
+
+/*
+ * To handle an interrupt, we read the TOPEI CSR and write zero in one
+ * instruction. If TOPEI CSR is non-zero then we translate TOPEI.ID to
+ * Linux interrupt number and let Linux IRQ subsystem handle it.
+ */
+static void imsic_handle_irq(struct irq_desc *desc)
+{
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	irq_hw_number_t hwirq;
+	int err;
+
+	chained_irq_enter(chip, desc);
+
+	while ((hwirq = csr_swap(CSR_TOPEI, 0))) {
+		hwirq = hwirq >> TOPEI_ID_SHIFT;
+
+		if (hwirq == imsic->ipi_id) {
+#ifdef CONFIG_SMP
+			ipi_mux_process();
+#endif
+			continue;
+		}
+
+		if (unlikely(!imsic->base_domain))
+			continue;
+
+		err = generic_handle_domain_irq(imsic->base_domain, hwirq);
+		if (unlikely(err))
+			pr_warn_ratelimited(
+				"hwirq %lu mapping not found\n", hwirq);
+	}
+
+	chained_irq_exit(chip, desc);
+}
+
+static int imsic_starting_cpu(unsigned int cpu)
+{
+	/* Enable per-CPU parent interrupt */
+	enable_percpu_irq(imsic_parent_irq,
+			  irq_get_trigger_type(imsic_parent_irq));
+
+	/* Setup IPIs */
+	imsic_ipi_starting_cpu();
+
+	/*
+	 * Interrupts identities might have been enabled/disabled while
+	 * this CPU was not running so sync-up local enable/disable state.
+	 */
+	imsic_ids_local_sync();
+
+	/* Enable local interrupt delivery */
+	imsic_ids_local_delivery(true);
+
+	return 0;
+}
+
+static int imsic_dying_cpu(unsigned int cpu)
+{
+	/* Cleanup IPIs */
+	imsic_ipi_dying_cpu();
+
+	return 0;
+}
+
+static int __init imsic_early_probe(struct fwnode_handle *fwnode)
+{
+	int rc;
+	struct irq_domain *domain;
+
+	/* Setup IMSIC state */
+	rc = imsic_setup_state(fwnode);
+	if (rc) {
+		pr_err("%pfwP: failed to setup state (error %d)\n",
+			fwnode, rc);
+		return rc;
+	}
+
+	/* Find parent domain and register chained handler */
+	domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
+					  DOMAIN_BUS_ANY);
+	if (!domain) {
+		pr_err("%pfwP: Failed to find INTC domain\n", fwnode);
+		return -ENOENT;
+	}
+	imsic_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT);
+	if (!imsic_parent_irq) {
+		pr_err("%pfwP: Failed to create INTC mapping\n", fwnode);
+		return -ENOENT;
+	}
+	irq_set_chained_handler(imsic_parent_irq, imsic_handle_irq);
+
+	/* Initialize IPI domain */
+	rc = imsic_ipi_domain_init();
+	if (rc) {
+		pr_err("%pfwP: Failed to initialize IPI domain\n", fwnode);
+		return rc;
+	}
+
+	/*
+	 * Setup cpuhp state (must be done after setting imsic_parent_irq)
+	 *
+	 * Don't disable per-CPU IMSIC file when CPU goes offline
+	 * because this affects IPI and the masking/unmasking of
+	 * virtual IPIs is done via generic IPI-Mux
+	 */
+	cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
+			  "irqchip/riscv/imsic:starting",
+			  imsic_starting_cpu, imsic_dying_cpu);
+
+	return 0;
+}
+
+static int __init imsic_early_dt_init(struct device_node *node,
+				      struct device_node *parent)
+{
+	int rc;
+
+	/* Do early setup of IMSIC state and IPIs */
+	rc = imsic_early_probe(&node->fwnode);
+	if (rc)
+		return rc;
+
+	/* Ensure that OF platform device gets probed */
+	of_node_clear_flag(node, OF_POPULATED);
+	return 0;
+}
+IRQCHIP_DECLARE(riscv_imsic, "riscv,imsics", imsic_early_dt_init);
diff --git a/drivers/irqchip/irq-riscv-imsic-state.c b/drivers/irqchip/irq-riscv-imsic-state.c
new file mode 100644
index 000000000000..412b5b919dcc
--- /dev/null
+++ b/drivers/irqchip/irq-riscv-imsic-state.c
@@ -0,0 +1,523 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+
+#define pr_fmt(fmt) "riscv-imsic: " fmt
+#include <linux/bitmap.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/spinlock.h>
+#include <linux/smp.h>
+#include <asm/hwcap.h>
+
+#include "irq-riscv-imsic-state.h"
+
+#define IMSIC_DISABLE_EIDELIVERY		0
+#define IMSIC_ENABLE_EIDELIVERY			1
+#define IMSIC_DISABLE_EITHRESHOLD		1
+#define IMSIC_ENABLE_EITHRESHOLD		0
+
+#define imsic_csr_write(__c, __v)		\
+do {						\
+	csr_write(CSR_ISELECT, __c);		\
+	csr_write(CSR_IREG, __v);		\
+} while (0)
+
+#define imsic_csr_read(__c)			\
+({						\
+	unsigned long __v;			\
+	csr_write(CSR_ISELECT, __c);		\
+	__v = csr_read(CSR_IREG);		\
+	__v;					\
+})
+
+#define imsic_csr_set(__c, __v)			\
+do {						\
+	csr_write(CSR_ISELECT, __c);		\
+	csr_set(CSR_IREG, __v);			\
+} while (0)
+
+#define imsic_csr_clear(__c, __v)		\
+do {						\
+	csr_write(CSR_ISELECT, __c);		\
+	csr_clear(CSR_IREG, __v);		\
+} while (0)
+
+struct imsic_priv *imsic;
+
+const struct imsic_global_config *imsic_get_global_config(void)
+{
+	return (imsic) ? &imsic->global : NULL;
+}
+EXPORT_SYMBOL_GPL(imsic_get_global_config);
+
+void __imsic_eix_update(unsigned long base_id,
+			unsigned long num_id, bool pend, bool val)
+{
+	unsigned long i, isel, ireg;
+	unsigned long id = base_id, last_id = base_id + num_id;
+
+	while (id < last_id) {
+		isel = id / BITS_PER_LONG;
+		isel *= BITS_PER_LONG / IMSIC_EIPx_BITS;
+		isel += (pend) ? IMSIC_EIP0 : IMSIC_EIE0;
+
+		ireg = 0;
+		for (i = id & (__riscv_xlen - 1);
+		     (id < last_id) && (i < __riscv_xlen); i++) {
+			ireg |= BIT(i);
+			id++;
+		}
+
+		/*
+		 * The IMSIC EIEx and EIPx registers are indirectly
+		 * accessed via using ISELECT and IREG CSRs so we
+		 * need to access these CSRs without getting preempted.
+		 *
+		 * All existing users of this function call this
+		 * function with local IRQs disabled so we don't
+		 * need to do anything special here.
+		 */
+		if (val)
+			imsic_csr_set(isel, ireg);
+		else
+			imsic_csr_clear(isel, ireg);
+	}
+}
+
+void imsic_id_set_target(unsigned int id, unsigned int target_cpu)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
+	imsic->ids_target_cpu[id] = target_cpu;
+	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
+}
+
+unsigned int imsic_id_get_target(unsigned int id)
+{
+	unsigned int ret;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
+	ret = imsic->ids_target_cpu[id];
+	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
+
+	return ret;
+}
+
+void imsic_ids_local_sync(void)
+{
+	int i;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
+	for (i = 1; i <= imsic->global.nr_ids; i++) {
+		if (imsic->ipi_id == i)
+			continue;
+
+		if (test_bit(i, imsic->ids_enabled_bimap))
+			__imsic_id_enable(i);
+		else
+			__imsic_id_disable(i);
+	}
+	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
+}
+
+void imsic_ids_local_delivery(bool enable)
+{
+	if (enable) {
+		imsic_csr_write(IMSIC_EITHRESHOLD, IMSIC_ENABLE_EITHRESHOLD);
+		imsic_csr_write(IMSIC_EIDELIVERY, IMSIC_ENABLE_EIDELIVERY);
+	} else {
+		imsic_csr_write(IMSIC_EIDELIVERY, IMSIC_DISABLE_EIDELIVERY);
+		imsic_csr_write(IMSIC_EITHRESHOLD, IMSIC_DISABLE_EITHRESHOLD);
+	}
+}
+
+int imsic_ids_alloc(unsigned int order)
+{
+	int ret;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
+	ret = bitmap_find_free_region(imsic->ids_used_bimap,
+				      imsic->global.nr_ids + 1, order);
+	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
+
+	return ret;
+}
+
+void imsic_ids_free(unsigned int base_id, unsigned int order)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
+	bitmap_release_region(imsic->ids_used_bimap, base_id, order);
+	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
+}
+
+static int __init imsic_ids_init(void)
+{
+	int i;
+	struct imsic_global_config *global = &imsic->global;
+
+	raw_spin_lock_init(&imsic->ids_lock);
+
+	/* Allocate used bitmap */
+	imsic->ids_used_bimap = bitmap_zalloc(global->nr_ids + 1, GFP_KERNEL);
+	if (!imsic->ids_used_bimap)
+		return -ENOMEM;
+
+	/* Allocate enabled bitmap */
+	imsic->ids_enabled_bimap = bitmap_zalloc(global->nr_ids + 1,
+						GFP_KERNEL);
+	if (!imsic->ids_enabled_bimap) {
+		kfree(imsic->ids_used_bimap);
+		return -ENOMEM;
+	}
+
+	/* Allocate target CPU array */
+	imsic->ids_target_cpu = kcalloc(global->nr_ids + 1,
+				       sizeof(unsigned int), GFP_KERNEL);
+	if (!imsic->ids_target_cpu) {
+		bitmap_free(imsic->ids_enabled_bimap);
+		bitmap_free(imsic->ids_used_bimap);
+		return -ENOMEM;
+	}
+	for (i = 0; i <= global->nr_ids; i++)
+		imsic->ids_target_cpu[i] = UINT_MAX;
+
+	/* Reserve ID#0 because it is special and never implemented */
+	bitmap_set(imsic->ids_used_bimap, 0, 1);
+
+	return 0;
+}
+
+static void __init imsic_ids_cleanup(void)
+{
+	kfree(imsic->ids_target_cpu);
+	bitmap_free(imsic->ids_enabled_bimap);
+	bitmap_free(imsic->ids_used_bimap);
+}
+
+static int __init imsic_get_parent_hartid(struct fwnode_handle *fwnode,
+					  u32 index, unsigned long *hartid)
+{
+	int rc;
+	struct fwnode_reference_args parent;
+
+	rc = fwnode_property_get_reference_args(fwnode,
+			"interrupts-extended", "#interrupt-cells",
+			0, index, &parent);
+	if (rc)
+		return rc;
+
+	/*
+	 * Skip interrupts other than external interrupts for
+	 * current privilege level.
+	 */
+	if (parent.args[0] != RV_IRQ_EXT)
+		return -EINVAL;
+
+	return riscv_get_intc_hartid(parent.fwnode, hartid);
+}
+
+static int __init imsic_get_mmio_resource(struct fwnode_handle *fwnode,
+					  u32 index, struct resource *res)
+{
+	/*
+	 * Currently, only OF fwnode is support so extend this function
+	 * for other types of fwnode for ACPI support.
+	 */
+	if (!is_of_node(fwnode))
+		return -EINVAL;
+	return of_address_to_resource(to_of_node(fwnode), index, res);
+}
+
+int __init imsic_setup_state(struct fwnode_handle *fwnode)
+{
+	int rc, cpu;
+	phys_addr_t base_addr;
+	void __iomem **mmios_va = NULL;
+	struct resource res, *mmios = NULL;
+	struct imsic_local_config *local;
+	struct imsic_global_config *global;
+	unsigned long reloff, hartid;
+	u32 i, j, index, nr_parent_irqs, nr_handlers = 0, num_mmios = 0;
+
+	/*
+	 * Only one IMSIC instance allowed in a platform for clean
+	 * implementation of SMP IRQ affinity and per-CPU IPIs.
+	 *
+	 * This means on a multi-socket (or multi-die) platform we
+	 * will have multiple MMIO regions for one IMSIC instance.
+	 */
+	if (imsic) {
+		pr_err("%pfwP: already initialized hence ignoring\n",
+			fwnode);
+		return -EALREADY;
+	}
+
+	if (!riscv_isa_extension_available(NULL, SxAIA)) {
+		pr_err("%pfwP: AIA support not available\n", fwnode);
+		return -ENODEV;
+	}
+
+	imsic = kzalloc(sizeof(*imsic), GFP_KERNEL);
+	if (!imsic)
+		return -ENOMEM;
+	imsic->fwnode = fwnode;
+	global = &imsic->global;
+
+	global->local = alloc_percpu(typeof(*(global->local)));
+	if (!global->local) {
+		rc = -ENOMEM;
+		goto out_free_priv;
+	}
+
+	/* Find number of parent interrupts */
+	nr_parent_irqs = 0;
+	while (!imsic_get_parent_hartid(fwnode, nr_parent_irqs, &hartid))
+		nr_parent_irqs++;
+	if (!nr_parent_irqs) {
+		pr_err("%pfwP: no parent irqs available\n", fwnode);
+		rc = -EINVAL;
+		goto out_free_local;
+	}
+
+	/* Find number of guest index bits in MSI address */
+	rc = fwnode_property_read_u32_array(fwnode, "riscv,guest-index-bits",
+					    &global->guest_index_bits, 1);
+	if (rc)
+		global->guest_index_bits = 0;
+	i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT;
+	if (i < global->guest_index_bits) {
+		pr_err("%pfwP: guest index bits too big\n", fwnode);
+		rc = -EINVAL;
+		goto out_free_local;
+	}
+
+	/* Find number of HART index bits */
+	rc = fwnode_property_read_u32_array(fwnode, "riscv,hart-index-bits",
+					    &global->hart_index_bits, 1);
+	if (rc) {
+		/* Assume default value */
+		global->hart_index_bits = __fls(nr_parent_irqs);
+		if (BIT(global->hart_index_bits) < nr_parent_irqs)
+			global->hart_index_bits++;
+	}
+	i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT - global->guest_index_bits;
+	if (i < global->hart_index_bits) {
+		pr_err("%pfwP: HART index bits too big\n", fwnode);
+		rc = -EINVAL;
+		goto out_free_local;
+	}
+
+	/* Find number of group index bits */
+	rc = fwnode_property_read_u32_array(fwnode, "riscv,group-index-bits",
+					    &global->group_index_bits, 1);
+	if (rc)
+		global->group_index_bits = 0;
+	i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT -
+	    global->guest_index_bits - global->hart_index_bits;
+	if (i < global->group_index_bits) {
+		pr_err("%pfwP: group index bits too big\n", fwnode);
+		rc = -EINVAL;
+		goto out_free_local;
+	}
+
+	/*
+	 * Find first bit position of group index.
+	 * If not specified assumed the default APLIC-IMSIC configuration.
+	 */
+	rc = fwnode_property_read_u32_array(fwnode, "riscv,group-index-shift",
+					    &global->group_index_shift, 1);
+	if (rc)
+		global->group_index_shift = IMSIC_MMIO_PAGE_SHIFT * 2;
+	i = global->group_index_bits + global->group_index_shift - 1;
+	if (i >= BITS_PER_LONG) {
+		pr_err("%pfwP: group index shift too big\n", fwnode);
+		rc = -EINVAL;
+		goto out_free_local;
+	}
+
+	/* Find number of interrupt identities */
+	rc = fwnode_property_read_u32_array(fwnode, "riscv,num-ids",
+					    &global->nr_ids, 1);
+	if (rc) {
+		pr_err("%pfwP: number of interrupt identities not found\n",
+			fwnode);
+		goto out_free_local;
+	}
+	if ((global->nr_ids < IMSIC_MIN_ID) ||
+	    (global->nr_ids >= IMSIC_MAX_ID) ||
+	    ((global->nr_ids & IMSIC_MIN_ID) != IMSIC_MIN_ID)) {
+		pr_err("%pfwP: invalid number of interrupt identities\n",
+			fwnode);
+		rc = -EINVAL;
+		goto out_free_local;
+	}
+
+	/* Find number of guest interrupt identities */
+	if (fwnode_property_read_u32_array(fwnode, "riscv,num-guest-ids",
+					   &global->nr_guest_ids, 1))
+		global->nr_guest_ids = global->nr_ids;
+	if ((global->nr_guest_ids < IMSIC_MIN_ID) ||
+	    (global->nr_guest_ids >= IMSIC_MAX_ID) ||
+	    ((global->nr_guest_ids & IMSIC_MIN_ID) != IMSIC_MIN_ID)) {
+		pr_err("%pfwP: invalid number of guest interrupt identities\n",
+			fwnode);
+		rc = -EINVAL;
+		goto out_free_local;
+	}
+
+	/* Compute base address */
+	rc = imsic_get_mmio_resource(fwnode, 0, &res);
+	if (rc) {
+		pr_err("%pfwP: first MMIO resource not found\n", fwnode);
+		rc = -EINVAL;
+		goto out_free_local;
+	}
+	global->base_addr = res.start;
+	global->base_addr &= ~(BIT(global->guest_index_bits +
+				   global->hart_index_bits +
+				   IMSIC_MMIO_PAGE_SHIFT) - 1);
+	global->base_addr &= ~((BIT(global->group_index_bits) - 1) <<
+			       global->group_index_shift);
+
+	/* Find number of MMIO register sets */
+	while (!imsic_get_mmio_resource(fwnode, num_mmios, &res))
+		num_mmios++;
+
+	/* Allocate MMIO resource array */
+	mmios = kcalloc(num_mmios, sizeof(*mmios), GFP_KERNEL);
+	if (!mmios) {
+		rc = -ENOMEM;
+		goto out_free_local;
+	}
+
+	/* Allocate MMIO virtual address array */
+	mmios_va = kcalloc(num_mmios, sizeof(*mmios_va), GFP_KERNEL);
+	if (!mmios_va) {
+		rc = -ENOMEM;
+		goto out_iounmap;
+	}
+
+	/* Parse and map MMIO register sets */
+	for (i = 0; i < num_mmios; i++) {
+		rc = imsic_get_mmio_resource(fwnode, i, &mmios[i]);
+		if (rc) {
+			pr_err("%pfwP: unable to parse MMIO regset %d\n",
+				fwnode, i);
+			goto out_iounmap;
+		}
+
+		base_addr = mmios[i].start;
+		base_addr &= ~(BIT(global->guest_index_bits +
+				   global->hart_index_bits +
+				   IMSIC_MMIO_PAGE_SHIFT) - 1);
+		base_addr &= ~((BIT(global->group_index_bits) - 1) <<
+			       global->group_index_shift);
+		if (base_addr != global->base_addr) {
+			rc = -EINVAL;
+			pr_err("%pfwP: address mismatch for regset %d\n",
+				fwnode, i);
+			goto out_iounmap;
+		}
+
+		mmios_va[i] = ioremap(mmios[i].start, resource_size(&mmios[i]));
+		if (!mmios_va[i]) {
+			rc = -EIO;
+			pr_err("%pfwP: unable to map MMIO regset %d\n",
+				fwnode, i);
+			goto out_iounmap;
+		}
+	}
+
+	/* Initialize interrupt identity management */
+	rc = imsic_ids_init();
+	if (rc) {
+		pr_err("%pfwP: failed to initialize interrupt management\n",
+		       fwnode);
+		goto out_iounmap;
+	}
+
+	/* Configure handlers for target CPUs */
+	for (i = 0; i < nr_parent_irqs; i++) {
+		rc = imsic_get_parent_hartid(fwnode, i, &hartid);
+		if (rc) {
+			pr_warn("%pfwP: hart ID for parent irq%d not found\n",
+				fwnode, i);
+			continue;
+		}
+
+		cpu = riscv_hartid_to_cpuid(hartid);
+		if (cpu < 0) {
+			pr_warn("%pfwP: invalid cpuid for parent irq%d\n",
+				fwnode, i);
+			continue;
+		}
+
+		/* Find MMIO location of MSI page */
+		index = num_mmios;
+		reloff = i * BIT(global->guest_index_bits) *
+			 IMSIC_MMIO_PAGE_SZ;
+		for (j = 0; num_mmios; j++) {
+			if (reloff < resource_size(&mmios[j])) {
+				index = j;
+				break;
+			}
+
+			/*
+			 * MMIO region size may not be aligned to
+			 * BIT(global->guest_index_bits) * IMSIC_MMIO_PAGE_SZ
+			 * if holes are present.
+			 */
+			reloff -= ALIGN(resource_size(&mmios[j]),
+			BIT(global->guest_index_bits) * IMSIC_MMIO_PAGE_SZ);
+		}
+		if (index >= num_mmios) {
+			pr_warn("%pfwP: MMIO not found for parent irq%d\n",
+				fwnode, i);
+			continue;
+		}
+
+		local = per_cpu_ptr(global->local, cpu);
+		local->msi_pa = mmios[index].start + reloff;
+		local->msi_va = mmios_va[index] + reloff;
+
+		nr_handlers++;
+	}
+
+	/* If no CPU handlers found then can't take interrupts */
+	if (!nr_handlers) {
+		pr_err("%pfwP: No CPU handlers found\n", fwnode);
+		rc = -ENODEV;
+		goto out_ids_cleanup;
+	}
+
+	/* We don't need MMIO arrays anymore so let's free-up */
+	kfree(mmios_va);
+	kfree(mmios);
+
+	return 0;
+
+out_ids_cleanup:
+	imsic_ids_cleanup();
+out_iounmap:
+	for (i = 0; i < num_mmios; i++) {
+		if (mmios_va[i])
+			iounmap(mmios_va[i]);
+	}
+	kfree(mmios_va);
+	kfree(mmios);
+out_free_local:
+	free_percpu(imsic->global.local);
+out_free_priv:
+	kfree(imsic);
+	imsic = NULL;
+	return rc;
+}
diff --git a/drivers/irqchip/irq-riscv-imsic-state.h b/drivers/irqchip/irq-riscv-imsic-state.h
new file mode 100644
index 000000000000..3170018949a8
--- /dev/null
+++ b/drivers/irqchip/irq-riscv-imsic-state.h
@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+
+#ifndef _IRQ_RISCV_IMSIC_STATE_H
+#define _IRQ_RISCV_IMSIC_STATE_H
+
+#include <linux/irqchip/riscv-imsic.h>
+#include <linux/irqdomain.h>
+#include <linux/fwnode.h>
+
+struct imsic_priv {
+	/* Device details */
+	struct fwnode_handle *fwnode;
+
+	/* Global configuration common for all HARTs */
+	struct imsic_global_config global;
+
+	/* Global state of interrupt identities */
+	raw_spinlock_t ids_lock;
+	unsigned long *ids_used_bimap;
+	unsigned long *ids_enabled_bimap;
+	unsigned int *ids_target_cpu;
+
+	/* IPI interrupt identity and synchronization */
+	u32 ipi_id;
+	int ipi_virq;
+	struct irq_desc *ipi_lsync_desc;
+
+	/* IRQ domains (created by platform driver) */
+	struct irq_domain *base_domain;
+	struct irq_domain *plat_domain;
+};
+
+extern struct imsic_priv *imsic;
+
+void __imsic_eix_update(unsigned long base_id,
+			unsigned long num_id, bool pend, bool val);
+
+#define __imsic_id_enable(__id)		\
+	__imsic_eix_update((__id), 1, false, true)
+#define __imsic_id_disable(__id)	\
+	__imsic_eix_update((__id), 1, false, false)
+
+void imsic_id_set_target(unsigned int id, unsigned int target_cpu);
+unsigned int imsic_id_get_target(unsigned int id);
+
+void imsic_ids_local_sync(void);
+void imsic_ids_local_delivery(bool enable);
+
+#ifdef CONFIG_SMP
+void imsic_ids_remote_sync(void);
+#else
+static inline void imsic_ids_remote_sync(void)
+{
+}
+#endif
+
+int imsic_ids_alloc(unsigned int order);
+void imsic_ids_free(unsigned int base_id, unsigned int order);
+
+int imsic_setup_state(struct fwnode_handle *fwnode);
+
+#endif
diff --git a/include/linux/irqchip/riscv-imsic.h b/include/linux/irqchip/riscv-imsic.h
new file mode 100644
index 000000000000..1f6fc9a57218
--- /dev/null
+++ b/include/linux/irqchip/riscv-imsic.h
@@ -0,0 +1,86 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+#ifndef __LINUX_IRQCHIP_RISCV_IMSIC_H
+#define __LINUX_IRQCHIP_RISCV_IMSIC_H
+
+#include <linux/types.h>
+#include <asm/csr.h>
+
+#define IMSIC_MMIO_PAGE_SHIFT		12
+#define IMSIC_MMIO_PAGE_SZ		(1UL << IMSIC_MMIO_PAGE_SHIFT)
+#define IMSIC_MMIO_PAGE_LE		0x00
+#define IMSIC_MMIO_PAGE_BE		0x04
+
+#define IMSIC_MIN_ID			63
+#define IMSIC_MAX_ID			2048
+
+#define IMSIC_EIDELIVERY		0x70
+
+#define IMSIC_EITHRESHOLD		0x72
+
+#define IMSIC_EIP0			0x80
+#define IMSIC_EIP63			0xbf
+#define IMSIC_EIPx_BITS			32
+
+#define IMSIC_EIE0			0xc0
+#define IMSIC_EIE63			0xff
+#define IMSIC_EIEx_BITS			32
+
+#define IMSIC_FIRST			IMSIC_EIDELIVERY
+#define IMSIC_LAST			IMSIC_EIE63
+
+#define IMSIC_MMIO_SETIPNUM_LE		0x00
+#define IMSIC_MMIO_SETIPNUM_BE		0x04
+
+struct imsic_local_config {
+	phys_addr_t msi_pa;
+	void __iomem *msi_va;
+};
+
+struct imsic_global_config {
+	/*
+	 * MSI Target Address Scheme
+	 *
+	 * XLEN-1                                                12     0
+	 * |                                                     |     |
+	 * -------------------------------------------------------------
+	 * |xxxxxx|Group Index|xxxxxxxxxxx|HART Index|Guest Index|  0  |
+	 * -------------------------------------------------------------
+	 */
+
+	/* Bits representing Guest index, HART index, and Group index */
+	u32 guest_index_bits;
+	u32 hart_index_bits;
+	u32 group_index_bits;
+	u32 group_index_shift;
+
+	/* Global base address matching all target MSI addresses */
+	phys_addr_t base_addr;
+
+	/* Number of interrupt identities */
+	u32 nr_ids;
+
+	/* Number of guest interrupt identities */
+	u32 nr_guest_ids;
+
+	/* Per-CPU IMSIC addresses */
+	struct imsic_local_config __percpu *local;
+};
+
+#ifdef CONFIG_RISCV_IMSIC
+
+extern const struct imsic_global_config *imsic_get_global_config(void);
+
+#else
+
+static inline const struct imsic_global_config *imsic_get_global_config(void)
+{
+	return NULL;
+}
+
+#endif
+
+#endif
-- 
2.34.1

[PATCH v8 09/16] irqchip: Add RISC-V incoming MSI controller early driver

[Anup Patel]

The RISC-V advanced interrupt architecture (AIA) specification
defines a new MSI controller called incoming message signalled
interrupt controller (IMSIC) which manages MSI on per-HART (or
per-CPU) basis. It also supports IPIs as software injected MSIs.
(For more details refer https://github.com/riscv/riscv-aia)

Let us add an early irqchip driver for RISC-V IMSIC which sets
up the IMSIC state and provide IPIs.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 drivers/irqchip/Kconfig                 |   7 +-
 drivers/irqchip/Makefile                |   1 +
 drivers/irqchip/irq-riscv-imsic-early.c | 258 ++++++++++++
 drivers/irqchip/irq-riscv-imsic-state.c | 523 ++++++++++++++++++++++++
 drivers/irqchip/irq-riscv-imsic-state.h |  66 +++
 include/linux/irqchip/riscv-imsic.h     |  86 ++++
 6 files changed, 940 insertions(+), 1 deletion(-)
 create mode 100644 drivers/irqchip/irq-riscv-imsic-early.c
 create mode 100644 drivers/irqchip/irq-riscv-imsic-state.c
 create mode 100644 drivers/irqchip/irq-riscv-imsic-state.h
 create mode 100644 include/linux/irqchip/riscv-imsic.h

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index f7149d0f3d45..ee99aacbefcc 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -30,7 +30,6 @@ config ARM_GIC_V2M
 
 config GIC_NON_BANKED
 	bool
-
 config ARM_GIC_V3
 	bool
 	select IRQ_DOMAIN_HIERARCHY
@@ -546,6 +545,12 @@ config SIFIVE_PLIC
 	select IRQ_DOMAIN_HIERARCHY
 	select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
 
+config RISCV_IMSIC
+	bool
+	depends on RISCV
+	select IRQ_DOMAIN_HIERARCHY
+	select GENERIC_MSI_IRQ
+
 config EXYNOS_IRQ_COMBINER
 	bool "Samsung Exynos IRQ combiner support" if COMPILE_TEST
 	depends on (ARCH_EXYNOS && ARM) || COMPILE_TEST
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index ffd945fe71aa..d714724387ce 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -95,6 +95,7 @@ obj-$(CONFIG_QCOM_MPM)			+= irq-qcom-mpm.o
 obj-$(CONFIG_CSKY_MPINTC)		+= irq-csky-mpintc.o
 obj-$(CONFIG_CSKY_APB_INTC)		+= irq-csky-apb-intc.o
 obj-$(CONFIG_RISCV_INTC)		+= irq-riscv-intc.o
+obj-$(CONFIG_RISCV_IMSIC)		+= irq-riscv-imsic-state.o irq-riscv-imsic-early.o
 obj-$(CONFIG_SIFIVE_PLIC)		+= irq-sifive-plic.o
 obj-$(CONFIG_IMX_IRQSTEER)		+= irq-imx-irqsteer.o
 obj-$(CONFIG_IMX_INTMUX)		+= irq-imx-intmux.o
diff --git a/drivers/irqchip/irq-riscv-imsic-early.c b/drivers/irqchip/irq-riscv-imsic-early.c
new file mode 100644
index 000000000000..1de89ce1ec2f
--- /dev/null
+++ b/drivers/irqchip/irq-riscv-imsic-early.c
@@ -0,0 +1,258 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+
+#define pr_fmt(fmt) "riscv-imsic: " fmt
+#include <linux/cpu.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/smp.h>
+
+#include "irq-riscv-imsic-state.h"
+
+/*
+ * The IMSIC driver uses 1 IPI for ID synchronization and
+ * arch/riscv/kernel/smp.c require 6 IPIs so we fix the
+ * total number of IPIs to 8.
+ */
+#define IMSIC_NR_IPI				8
+
+static int imsic_parent_irq;
+
+#ifdef CONFIG_SMP
+static irqreturn_t imsic_ids_sync_handler(int irq, void *data)
+{
+	imsic_ids_local_sync();
+	return IRQ_HANDLED;
+}
+
+void imsic_ids_remote_sync(void)
+{
+	struct cpumask amask;
+
+	/*
+	 * We simply inject ID synchronization IPI to all target CPUs
+	 * except current CPU. The ipi_send_mask() implementation of
+	 * IPI mux will inject ID synchronization IPI only for CPUs
+	 * that have enabled it so offline CPUs won't receive IPI.
+	 * An offline CPU will unconditionally synchronize IDs through
+	 * imsic_starting_cpu() when the CPU is brought up.
+	 */
+	cpumask_andnot(&amask, cpu_online_mask, cpumask_of(smp_processor_id()));
+	__ipi_send_mask(imsic->ipi_lsync_desc, &amask);
+}
+
+static void imsic_ipi_send(unsigned int cpu)
+{
+	struct imsic_local_config *local =
+				per_cpu_ptr(imsic->global.local, cpu);
+
+	writel(imsic->ipi_id, local->msi_va);
+}
+
+static void imsic_ipi_starting_cpu(void)
+{
+	/* Enable IPIs for current CPU. */
+	__imsic_id_enable(imsic->ipi_id);
+
+	/* Enable virtual IPI used for IMSIC ID synchronization */
+	enable_percpu_irq(imsic->ipi_virq, 0);
+}
+
+static void imsic_ipi_dying_cpu(void)
+{
+	/*
+	 * Disable virtual IPI used for IMSIC ID synchronization so
+	 * that we don't receive ID synchronization requests.
+	 */
+	disable_percpu_irq(imsic->ipi_virq);
+}
+
+static int __init imsic_ipi_domain_init(void)
+{
+	int virq;
+
+	/* Allocate interrupt identity for IPIs */
+	virq = imsic_ids_alloc(get_count_order(1));
+	if (virq < 0)
+		return virq;
+	imsic->ipi_id = virq;
+
+	/* Create IMSIC IPI multiplexing */
+	virq = ipi_mux_create(IMSIC_NR_IPI, imsic_ipi_send);
+	if (virq <= 0) {
+		imsic_ids_free(imsic->ipi_id, get_count_order(1));
+		return (virq < 0) ? virq : -ENOMEM;
+	}
+	imsic->ipi_virq = virq;
+
+	/* First vIRQ is used for IMSIC ID synchronization */
+	virq = request_percpu_irq(imsic->ipi_virq, imsic_ids_sync_handler,
+				  "riscv-imsic-lsync", imsic->global.local);
+	if (virq) {
+		imsic_ids_free(imsic->ipi_id, get_count_order(1));
+		return virq;
+	}
+	irq_set_status_flags(imsic->ipi_virq, IRQ_HIDDEN);
+	imsic->ipi_lsync_desc = irq_to_desc(imsic->ipi_virq);
+
+	/* Set vIRQ range */
+	riscv_ipi_set_virq_range(imsic->ipi_virq + 1, IMSIC_NR_IPI - 1, true);
+
+	/* Announce that IMSIC is providing IPIs */
+	pr_info("%pfwP: providing IPIs using interrupt %d\n",
+		imsic->fwnode, imsic->ipi_id);
+
+	return 0;
+}
+#else
+static void imsic_ipi_starting_cpu(void)
+{
+}
+
+static void imsic_ipi_dying_cpu(void)
+{
+}
+
+static int __init imsic_ipi_domain_init(void)
+{
+	/* Clear the IPI id because we are not using IPIs */
+	imsic->ipi_id = 0;
+	return 0;
+}
+#endif
+
+/*
+ * To handle an interrupt, we read the TOPEI CSR and write zero in one
+ * instruction. If TOPEI CSR is non-zero then we translate TOPEI.ID to
+ * Linux interrupt number and let Linux IRQ subsystem handle it.
+ */
+static void imsic_handle_irq(struct irq_desc *desc)
+{
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	irq_hw_number_t hwirq;
+	int err;
+
+	chained_irq_enter(chip, desc);
+
+	while ((hwirq = csr_swap(CSR_TOPEI, 0))) {
+		hwirq = hwirq >> TOPEI_ID_SHIFT;
+
+		if (hwirq == imsic->ipi_id) {
+#ifdef CONFIG_SMP
+			ipi_mux_process();
+#endif
+			continue;
+		}
+
+		if (unlikely(!imsic->base_domain))
+			continue;
+
+		err = generic_handle_domain_irq(imsic->base_domain, hwirq);
+		if (unlikely(err))
+			pr_warn_ratelimited(
+				"hwirq %lu mapping not found\n", hwirq);
+	}
+
+	chained_irq_exit(chip, desc);
+}
+
+static int imsic_starting_cpu(unsigned int cpu)
+{
+	/* Enable per-CPU parent interrupt */
+	enable_percpu_irq(imsic_parent_irq,
+			  irq_get_trigger_type(imsic_parent_irq));
+
+	/* Setup IPIs */
+	imsic_ipi_starting_cpu();
+
+	/*
+	 * Interrupts identities might have been enabled/disabled while
+	 * this CPU was not running so sync-up local enable/disable state.
+	 */
+	imsic_ids_local_sync();
+
+	/* Enable local interrupt delivery */
+	imsic_ids_local_delivery(true);
+
+	return 0;
+}
+
+static int imsic_dying_cpu(unsigned int cpu)
+{
+	/* Cleanup IPIs */
+	imsic_ipi_dying_cpu();
+
+	return 0;
+}
+
+static int __init imsic_early_probe(struct fwnode_handle *fwnode)
+{
+	int rc;
+	struct irq_domain *domain;
+
+	/* Setup IMSIC state */
+	rc = imsic_setup_state(fwnode);
+	if (rc) {
+		pr_err("%pfwP: failed to setup state (error %d)\n",
+			fwnode, rc);
+		return rc;
+	}
+
+	/* Find parent domain and register chained handler */
+	domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
+					  DOMAIN_BUS_ANY);
+	if (!domain) {
+		pr_err("%pfwP: Failed to find INTC domain\n", fwnode);
+		return -ENOENT;
+	}
+	imsic_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT);
+	if (!imsic_parent_irq) {
+		pr_err("%pfwP: Failed to create INTC mapping\n", fwnode);
+		return -ENOENT;
+	}
+	irq_set_chained_handler(imsic_parent_irq, imsic_handle_irq);
+
+	/* Initialize IPI domain */
+	rc = imsic_ipi_domain_init();
+	if (rc) {
+		pr_err("%pfwP: Failed to initialize IPI domain\n", fwnode);
+		return rc;
+	}
+
+	/*
+	 * Setup cpuhp state (must be done after setting imsic_parent_irq)
+	 *
+	 * Don't disable per-CPU IMSIC file when CPU goes offline
+	 * because this affects IPI and the masking/unmasking of
+	 * virtual IPIs is done via generic IPI-Mux
+	 */
+	cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
+			  "irqchip/riscv/imsic:starting",
+			  imsic_starting_cpu, imsic_dying_cpu);
+
+	return 0;
+}
+
+static int __init imsic_early_dt_init(struct device_node *node,
+				      struct device_node *parent)
+{
+	int rc;
+
+	/* Do early setup of IMSIC state and IPIs */
+	rc = imsic_early_probe(&node->fwnode);
+	if (rc)
+		return rc;
+
+	/* Ensure that OF platform device gets probed */
+	of_node_clear_flag(node, OF_POPULATED);
+	return 0;
+}
+IRQCHIP_DECLARE(riscv_imsic, "riscv,imsics", imsic_early_dt_init);
diff --git a/drivers/irqchip/irq-riscv-imsic-state.c b/drivers/irqchip/irq-riscv-imsic-state.c
new file mode 100644
index 000000000000..412b5b919dcc
--- /dev/null
+++ b/drivers/irqchip/irq-riscv-imsic-state.c
@@ -0,0 +1,523 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+
+#define pr_fmt(fmt) "riscv-imsic: " fmt
+#include <linux/bitmap.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/spinlock.h>
+#include <linux/smp.h>
+#include <asm/hwcap.h>
+
+#include "irq-riscv-imsic-state.h"
+
+#define IMSIC_DISABLE_EIDELIVERY		0
+#define IMSIC_ENABLE_EIDELIVERY			1
+#define IMSIC_DISABLE_EITHRESHOLD		1
+#define IMSIC_ENABLE_EITHRESHOLD		0
+
+#define imsic_csr_write(__c, __v)		\
+do {						\
+	csr_write(CSR_ISELECT, __c);		\
+	csr_write(CSR_IREG, __v);		\
+} while (0)
+
+#define imsic_csr_read(__c)			\
+({						\
+	unsigned long __v;			\
+	csr_write(CSR_ISELECT, __c);		\
+	__v = csr_read(CSR_IREG);		\
+	__v;					\
+})
+
+#define imsic_csr_set(__c, __v)			\
+do {						\
+	csr_write(CSR_ISELECT, __c);		\
+	csr_set(CSR_IREG, __v);			\
+} while (0)
+
+#define imsic_csr_clear(__c, __v)		\
+do {						\
+	csr_write(CSR_ISELECT, __c);		\
+	csr_clear(CSR_IREG, __v);		\
+} while (0)
+
+struct imsic_priv *imsic;
+
+const struct imsic_global_config *imsic_get_global_config(void)
+{
+	return (imsic) ? &imsic->global : NULL;
+}
+EXPORT_SYMBOL_GPL(imsic_get_global_config);
+
+void __imsic_eix_update(unsigned long base_id,
+			unsigned long num_id, bool pend, bool val)
+{
+	unsigned long i, isel, ireg;
+	unsigned long id = base_id, last_id = base_id + num_id;
+
+	while (id < last_id) {
+		isel = id / BITS_PER_LONG;
+		isel *= BITS_PER_LONG / IMSIC_EIPx_BITS;
+		isel += (pend) ? IMSIC_EIP0 : IMSIC_EIE0;
+
+		ireg = 0;
+		for (i = id & (__riscv_xlen - 1);
+		     (id < last_id) && (i < __riscv_xlen); i++) {
+			ireg |= BIT(i);
+			id++;
+		}
+
+		/*
+		 * The IMSIC EIEx and EIPx registers are indirectly
+		 * accessed via using ISELECT and IREG CSRs so we
+		 * need to access these CSRs without getting preempted.
+		 *
+		 * All existing users of this function call this
+		 * function with local IRQs disabled so we don't
+		 * need to do anything special here.
+		 */
+		if (val)
+			imsic_csr_set(isel, ireg);
+		else
+			imsic_csr_clear(isel, ireg);
+	}
+}
+
+void imsic_id_set_target(unsigned int id, unsigned int target_cpu)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
+	imsic->ids_target_cpu[id] = target_cpu;
+	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
+}
+
+unsigned int imsic_id_get_target(unsigned int id)
+{
+	unsigned int ret;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
+	ret = imsic->ids_target_cpu[id];
+	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
+
+	return ret;
+}
+
+void imsic_ids_local_sync(void)
+{
+	int i;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
+	for (i = 1; i <= imsic->global.nr_ids; i++) {
+		if (imsic->ipi_id == i)
+			continue;
+
+		if (test_bit(i, imsic->ids_enabled_bimap))
+			__imsic_id_enable(i);
+		else
+			__imsic_id_disable(i);
+	}
+	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
+}
+
+void imsic_ids_local_delivery(bool enable)
+{
+	if (enable) {
+		imsic_csr_write(IMSIC_EITHRESHOLD, IMSIC_ENABLE_EITHRESHOLD);
+		imsic_csr_write(IMSIC_EIDELIVERY, IMSIC_ENABLE_EIDELIVERY);
+	} else {
+		imsic_csr_write(IMSIC_EIDELIVERY, IMSIC_DISABLE_EIDELIVERY);
+		imsic_csr_write(IMSIC_EITHRESHOLD, IMSIC_DISABLE_EITHRESHOLD);
+	}
+}
+
+int imsic_ids_alloc(unsigned int order)
+{
+	int ret;
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
+	ret = bitmap_find_free_region(imsic->ids_used_bimap,
+				      imsic->global.nr_ids + 1, order);
+	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
+
+	return ret;
+}
+
+void imsic_ids_free(unsigned int base_id, unsigned int order)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
+	bitmap_release_region(imsic->ids_used_bimap, base_id, order);
+	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
+}
+
+static int __init imsic_ids_init(void)
+{
+	int i;
+	struct imsic_global_config *global = &imsic->global;
+
+	raw_spin_lock_init(&imsic->ids_lock);
+
+	/* Allocate used bitmap */
+	imsic->ids_used_bimap = bitmap_zalloc(global->nr_ids + 1, GFP_KERNEL);
+	if (!imsic->ids_used_bimap)
+		return -ENOMEM;
+
+	/* Allocate enabled bitmap */
+	imsic->ids_enabled_bimap = bitmap_zalloc(global->nr_ids + 1,
+						GFP_KERNEL);
+	if (!imsic->ids_enabled_bimap) {
+		kfree(imsic->ids_used_bimap);
+		return -ENOMEM;
+	}
+
+	/* Allocate target CPU array */
+	imsic->ids_target_cpu = kcalloc(global->nr_ids + 1,
+				       sizeof(unsigned int), GFP_KERNEL);
+	if (!imsic->ids_target_cpu) {
+		bitmap_free(imsic->ids_enabled_bimap);
+		bitmap_free(imsic->ids_used_bimap);
+		return -ENOMEM;
+	}
+	for (i = 0; i <= global->nr_ids; i++)
+		imsic->ids_target_cpu[i] = UINT_MAX;
+
+	/* Reserve ID#0 because it is special and never implemented */
+	bitmap_set(imsic->ids_used_bimap, 0, 1);
+
+	return 0;
+}
+
+static void __init imsic_ids_cleanup(void)
+{
+	kfree(imsic->ids_target_cpu);
+	bitmap_free(imsic->ids_enabled_bimap);
+	bitmap_free(imsic->ids_used_bimap);
+}
+
+static int __init imsic_get_parent_hartid(struct fwnode_handle *fwnode,
+					  u32 index, unsigned long *hartid)
+{
+	int rc;
+	struct fwnode_reference_args parent;
+
+	rc = fwnode_property_get_reference_args(fwnode,
+			"interrupts-extended", "#interrupt-cells",
+			0, index, &parent);
+	if (rc)
+		return rc;
+
+	/*
+	 * Skip interrupts other than external interrupts for
+	 * current privilege level.
+	 */
+	if (parent.args[0] != RV_IRQ_EXT)
+		return -EINVAL;
+
+	return riscv_get_intc_hartid(parent.fwnode, hartid);
+}
+
+static int __init imsic_get_mmio_resource(struct fwnode_handle *fwnode,
+					  u32 index, struct resource *res)
+{
+	/*
+	 * Currently, only OF fwnode is support so extend this function
+	 * for other types of fwnode for ACPI support.
+	 */
+	if (!is_of_node(fwnode))
+		return -EINVAL;
+	return of_address_to_resource(to_of_node(fwnode), index, res);
+}
+
+int __init imsic_setup_state(struct fwnode_handle *fwnode)
+{
+	int rc, cpu;
+	phys_addr_t base_addr;
+	void __iomem **mmios_va = NULL;
+	struct resource res, *mmios = NULL;
+	struct imsic_local_config *local;
+	struct imsic_global_config *global;
+	unsigned long reloff, hartid;
+	u32 i, j, index, nr_parent_irqs, nr_handlers = 0, num_mmios = 0;
+
+	/*
+	 * Only one IMSIC instance allowed in a platform for clean
+	 * implementation of SMP IRQ affinity and per-CPU IPIs.
+	 *
+	 * This means on a multi-socket (or multi-die) platform we
+	 * will have multiple MMIO regions for one IMSIC instance.
+	 */
+	if (imsic) {
+		pr_err("%pfwP: already initialized hence ignoring\n",
+			fwnode);
+		return -EALREADY;
+	}
+
+	if (!riscv_isa_extension_available(NULL, SxAIA)) {
+		pr_err("%pfwP: AIA support not available\n", fwnode);
+		return -ENODEV;
+	}
+
+	imsic = kzalloc(sizeof(*imsic), GFP_KERNEL);
+	if (!imsic)
+		return -ENOMEM;
+	imsic->fwnode = fwnode;
+	global = &imsic->global;
+
+	global->local = alloc_percpu(typeof(*(global->local)));
+	if (!global->local) {
+		rc = -ENOMEM;
+		goto out_free_priv;
+	}
+
+	/* Find number of parent interrupts */
+	nr_parent_irqs = 0;
+	while (!imsic_get_parent_hartid(fwnode, nr_parent_irqs, &hartid))
+		nr_parent_irqs++;
+	if (!nr_parent_irqs) {
+		pr_err("%pfwP: no parent irqs available\n", fwnode);
+		rc = -EINVAL;
+		goto out_free_local;
+	}
+
+	/* Find number of guest index bits in MSI address */
+	rc = fwnode_property_read_u32_array(fwnode, "riscv,guest-index-bits",
+					    &global->guest_index_bits, 1);
+	if (rc)
+		global->guest_index_bits = 0;
+	i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT;
+	if (i < global->guest_index_bits) {
+		pr_err("%pfwP: guest index bits too big\n", fwnode);
+		rc = -EINVAL;
+		goto out_free_local;
+	}
+
+	/* Find number of HART index bits */
+	rc = fwnode_property_read_u32_array(fwnode, "riscv,hart-index-bits",
+					    &global->hart_index_bits, 1);
+	if (rc) {
+		/* Assume default value */
+		global->hart_index_bits = __fls(nr_parent_irqs);
+		if (BIT(global->hart_index_bits) < nr_parent_irqs)
+			global->hart_index_bits++;
+	}
+	i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT - global->guest_index_bits;
+	if (i < global->hart_index_bits) {
+		pr_err("%pfwP: HART index bits too big\n", fwnode);
+		rc = -EINVAL;
+		goto out_free_local;
+	}
+
+	/* Find number of group index bits */
+	rc = fwnode_property_read_u32_array(fwnode, "riscv,group-index-bits",
+					    &global->group_index_bits, 1);
+	if (rc)
+		global->group_index_bits = 0;
+	i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT -
+	    global->guest_index_bits - global->hart_index_bits;
+	if (i < global->group_index_bits) {
+		pr_err("%pfwP: group index bits too big\n", fwnode);
+		rc = -EINVAL;
+		goto out_free_local;
+	}
+
+	/*
+	 * Find first bit position of group index.
+	 * If not specified assumed the default APLIC-IMSIC configuration.
+	 */
+	rc = fwnode_property_read_u32_array(fwnode, "riscv,group-index-shift",
+					    &global->group_index_shift, 1);
+	if (rc)
+		global->group_index_shift = IMSIC_MMIO_PAGE_SHIFT * 2;
+	i = global->group_index_bits + global->group_index_shift - 1;
+	if (i >= BITS_PER_LONG) {
+		pr_err("%pfwP: group index shift too big\n", fwnode);
+		rc = -EINVAL;
+		goto out_free_local;
+	}
+
+	/* Find number of interrupt identities */
+	rc = fwnode_property_read_u32_array(fwnode, "riscv,num-ids",
+					    &global->nr_ids, 1);
+	if (rc) {
+		pr_err("%pfwP: number of interrupt identities not found\n",
+			fwnode);
+		goto out_free_local;
+	}
+	if ((global->nr_ids < IMSIC_MIN_ID) ||
+	    (global->nr_ids >= IMSIC_MAX_ID) ||
+	    ((global->nr_ids & IMSIC_MIN_ID) != IMSIC_MIN_ID)) {
+		pr_err("%pfwP: invalid number of interrupt identities\n",
+			fwnode);
+		rc = -EINVAL;
+		goto out_free_local;
+	}
+
+	/* Find number of guest interrupt identities */
+	if (fwnode_property_read_u32_array(fwnode, "riscv,num-guest-ids",
+					   &global->nr_guest_ids, 1))
+		global->nr_guest_ids = global->nr_ids;
+	if ((global->nr_guest_ids < IMSIC_MIN_ID) ||
+	    (global->nr_guest_ids >= IMSIC_MAX_ID) ||
+	    ((global->nr_guest_ids & IMSIC_MIN_ID) != IMSIC_MIN_ID)) {
+		pr_err("%pfwP: invalid number of guest interrupt identities\n",
+			fwnode);
+		rc = -EINVAL;
+		goto out_free_local;
+	}
+
+	/* Compute base address */
+	rc = imsic_get_mmio_resource(fwnode, 0, &res);
+	if (rc) {
+		pr_err("%pfwP: first MMIO resource not found\n", fwnode);
+		rc = -EINVAL;
+		goto out_free_local;
+	}
+	global->base_addr = res.start;
+	global->base_addr &= ~(BIT(global->guest_index_bits +
+				   global->hart_index_bits +
+				   IMSIC_MMIO_PAGE_SHIFT) - 1);
+	global->base_addr &= ~((BIT(global->group_index_bits) - 1) <<
+			       global->group_index_shift);
+
+	/* Find number of MMIO register sets */
+	while (!imsic_get_mmio_resource(fwnode, num_mmios, &res))
+		num_mmios++;
+
+	/* Allocate MMIO resource array */
+	mmios = kcalloc(num_mmios, sizeof(*mmios), GFP_KERNEL);
+	if (!mmios) {
+		rc = -ENOMEM;
+		goto out_free_local;
+	}
+
+	/* Allocate MMIO virtual address array */
+	mmios_va = kcalloc(num_mmios, sizeof(*mmios_va), GFP_KERNEL);
+	if (!mmios_va) {
+		rc = -ENOMEM;
+		goto out_iounmap;
+	}
+
+	/* Parse and map MMIO register sets */
+	for (i = 0; i < num_mmios; i++) {
+		rc = imsic_get_mmio_resource(fwnode, i, &mmios[i]);
+		if (rc) {
+			pr_err("%pfwP: unable to parse MMIO regset %d\n",
+				fwnode, i);
+			goto out_iounmap;
+		}
+
+		base_addr = mmios[i].start;
+		base_addr &= ~(BIT(global->guest_index_bits +
+				   global->hart_index_bits +
+				   IMSIC_MMIO_PAGE_SHIFT) - 1);
+		base_addr &= ~((BIT(global->group_index_bits) - 1) <<
+			       global->group_index_shift);
+		if (base_addr != global->base_addr) {
+			rc = -EINVAL;
+			pr_err("%pfwP: address mismatch for regset %d\n",
+				fwnode, i);
+			goto out_iounmap;
+		}
+
+		mmios_va[i] = ioremap(mmios[i].start, resource_size(&mmios[i]));
+		if (!mmios_va[i]) {
+			rc = -EIO;
+			pr_err("%pfwP: unable to map MMIO regset %d\n",
+				fwnode, i);
+			goto out_iounmap;
+		}
+	}
+
+	/* Initialize interrupt identity management */
+	rc = imsic_ids_init();
+	if (rc) {
+		pr_err("%pfwP: failed to initialize interrupt management\n",
+		       fwnode);
+		goto out_iounmap;
+	}
+
+	/* Configure handlers for target CPUs */
+	for (i = 0; i < nr_parent_irqs; i++) {
+		rc = imsic_get_parent_hartid(fwnode, i, &hartid);
+		if (rc) {
+			pr_warn("%pfwP: hart ID for parent irq%d not found\n",
+				fwnode, i);
+			continue;
+		}
+
+		cpu = riscv_hartid_to_cpuid(hartid);
+		if (cpu < 0) {
+			pr_warn("%pfwP: invalid cpuid for parent irq%d\n",
+				fwnode, i);
+			continue;
+		}
+
+		/* Find MMIO location of MSI page */
+		index = num_mmios;
+		reloff = i * BIT(global->guest_index_bits) *
+			 IMSIC_MMIO_PAGE_SZ;
+		for (j = 0; num_mmios; j++) {
+			if (reloff < resource_size(&mmios[j])) {
+				index = j;
+				break;
+			}
+
+			/*
+			 * MMIO region size may not be aligned to
+			 * BIT(global->guest_index_bits) * IMSIC_MMIO_PAGE_SZ
+			 * if holes are present.
+			 */
+			reloff -= ALIGN(resource_size(&mmios[j]),
+			BIT(global->guest_index_bits) * IMSIC_MMIO_PAGE_SZ);
+		}
+		if (index >= num_mmios) {
+			pr_warn("%pfwP: MMIO not found for parent irq%d\n",
+				fwnode, i);
+			continue;
+		}
+
+		local = per_cpu_ptr(global->local, cpu);
+		local->msi_pa = mmios[index].start + reloff;
+		local->msi_va = mmios_va[index] + reloff;
+
+		nr_handlers++;
+	}
+
+	/* If no CPU handlers found then can't take interrupts */
+	if (!nr_handlers) {
+		pr_err("%pfwP: No CPU handlers found\n", fwnode);
+		rc = -ENODEV;
+		goto out_ids_cleanup;
+	}
+
+	/* We don't need MMIO arrays anymore so let's free-up */
+	kfree(mmios_va);
+	kfree(mmios);
+
+	return 0;
+
+out_ids_cleanup:
+	imsic_ids_cleanup();
+out_iounmap:
+	for (i = 0; i < num_mmios; i++) {
+		if (mmios_va[i])
+			iounmap(mmios_va[i]);
+	}
+	kfree(mmios_va);
+	kfree(mmios);
+out_free_local:
+	free_percpu(imsic->global.local);
+out_free_priv:
+	kfree(imsic);
+	imsic = NULL;
+	return rc;
+}
diff --git a/drivers/irqchip/irq-riscv-imsic-state.h b/drivers/irqchip/irq-riscv-imsic-state.h
new file mode 100644
index 000000000000..3170018949a8
--- /dev/null
+++ b/drivers/irqchip/irq-riscv-imsic-state.h
@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+
+#ifndef _IRQ_RISCV_IMSIC_STATE_H
+#define _IRQ_RISCV_IMSIC_STATE_H
+
+#include <linux/irqchip/riscv-imsic.h>
+#include <linux/irqdomain.h>
+#include <linux/fwnode.h>
+
+struct imsic_priv {
+	/* Device details */
+	struct fwnode_handle *fwnode;
+
+	/* Global configuration common for all HARTs */
+	struct imsic_global_config global;
+
+	/* Global state of interrupt identities */
+	raw_spinlock_t ids_lock;
+	unsigned long *ids_used_bimap;
+	unsigned long *ids_enabled_bimap;
+	unsigned int *ids_target_cpu;
+
+	/* IPI interrupt identity and synchronization */
+	u32 ipi_id;
+	int ipi_virq;
+	struct irq_desc *ipi_lsync_desc;
+
+	/* IRQ domains (created by platform driver) */
+	struct irq_domain *base_domain;
+	struct irq_domain *plat_domain;
+};
+
+extern struct imsic_priv *imsic;
+
+void __imsic_eix_update(unsigned long base_id,
+			unsigned long num_id, bool pend, bool val);
+
+#define __imsic_id_enable(__id)		\
+	__imsic_eix_update((__id), 1, false, true)
+#define __imsic_id_disable(__id)	\
+	__imsic_eix_update((__id), 1, false, false)
+
+void imsic_id_set_target(unsigned int id, unsigned int target_cpu);
+unsigned int imsic_id_get_target(unsigned int id);
+
+void imsic_ids_local_sync(void);
+void imsic_ids_local_delivery(bool enable);
+
+#ifdef CONFIG_SMP
+void imsic_ids_remote_sync(void);
+#else
+static inline void imsic_ids_remote_sync(void)
+{
+}
+#endif
+
+int imsic_ids_alloc(unsigned int order);
+void imsic_ids_free(unsigned int base_id, unsigned int order);
+
+int imsic_setup_state(struct fwnode_handle *fwnode);
+
+#endif
diff --git a/include/linux/irqchip/riscv-imsic.h b/include/linux/irqchip/riscv-imsic.h
new file mode 100644
index 000000000000..1f6fc9a57218
--- /dev/null
+++ b/include/linux/irqchip/riscv-imsic.h
@@ -0,0 +1,86 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+#ifndef __LINUX_IRQCHIP_RISCV_IMSIC_H
+#define __LINUX_IRQCHIP_RISCV_IMSIC_H
+
+#include <linux/types.h>
+#include <asm/csr.h>
+
+#define IMSIC_MMIO_PAGE_SHIFT		12
+#define IMSIC_MMIO_PAGE_SZ		(1UL << IMSIC_MMIO_PAGE_SHIFT)
+#define IMSIC_MMIO_PAGE_LE		0x00
+#define IMSIC_MMIO_PAGE_BE		0x04
+
+#define IMSIC_MIN_ID			63
+#define IMSIC_MAX_ID			2048
+
+#define IMSIC_EIDELIVERY		0x70
+
+#define IMSIC_EITHRESHOLD		0x72
+
+#define IMSIC_EIP0			0x80
+#define IMSIC_EIP63			0xbf
+#define IMSIC_EIPx_BITS			32
+
+#define IMSIC_EIE0			0xc0
+#define IMSIC_EIE63			0xff
+#define IMSIC_EIEx_BITS			32
+
+#define IMSIC_FIRST			IMSIC_EIDELIVERY
+#define IMSIC_LAST			IMSIC_EIE63
+
+#define IMSIC_MMIO_SETIPNUM_LE		0x00
+#define IMSIC_MMIO_SETIPNUM_BE		0x04
+
+struct imsic_local_config {
+	phys_addr_t msi_pa;
+	void __iomem *msi_va;
+};
+
+struct imsic_global_config {
+	/*
+	 * MSI Target Address Scheme
+	 *
+	 * XLEN-1                                                12     0
+	 * |                                                     |     |
+	 * -------------------------------------------------------------
+	 * |xxxxxx|Group Index|xxxxxxxxxxx|HART Index|Guest Index|  0  |
+	 * -------------------------------------------------------------
+	 */
+
+	/* Bits representing Guest index, HART index, and Group index */
+	u32 guest_index_bits;
+	u32 hart_index_bits;
+	u32 group_index_bits;
+	u32 group_index_shift;
+
+	/* Global base address matching all target MSI addresses */
+	phys_addr_t base_addr;
+
+	/* Number of interrupt identities */
+	u32 nr_ids;
+
+	/* Number of guest interrupt identities */
+	u32 nr_guest_ids;
+
+	/* Per-CPU IMSIC addresses */
+	struct imsic_local_config __percpu *local;
+};
+
+#ifdef CONFIG_RISCV_IMSIC
+
+extern const struct imsic_global_config *imsic_get_global_config(void);
+
+#else
+
+static inline const struct imsic_global_config *imsic_get_global_config(void)
+{
+	return NULL;
+}
+
+#endif
+
+#endif
-- 
2.34.1


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[PATCH v8 10/16] irqchip/riscv-imsic: Add support for platform MSI irqdomain

[Anup Patel]

The Linux platform MSI support requires a platform MSI irqdomain so
let us add a platform irqchip driver for RISC-V IMSIC which provides
a base IRQ domain and platform MSI domain. This driver assumes that
the IMSIC state is already initialized by the IMSIC early driver.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 drivers/irqchip/Makefile                   |   2 +-
 drivers/irqchip/irq-riscv-imsic-platform.c | 280 +++++++++++++++++++++
 2 files changed, 281 insertions(+), 1 deletion(-)
 create mode 100644 drivers/irqchip/irq-riscv-imsic-platform.c

diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index d714724387ce..abca445a3229 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -95,7 +95,7 @@ obj-$(CONFIG_QCOM_MPM)			+= irq-qcom-mpm.o
 obj-$(CONFIG_CSKY_MPINTC)		+= irq-csky-mpintc.o
 obj-$(CONFIG_CSKY_APB_INTC)		+= irq-csky-apb-intc.o
 obj-$(CONFIG_RISCV_INTC)		+= irq-riscv-intc.o
-obj-$(CONFIG_RISCV_IMSIC)		+= irq-riscv-imsic-state.o irq-riscv-imsic-early.o
+obj-$(CONFIG_RISCV_IMSIC)		+= irq-riscv-imsic-state.o irq-riscv-imsic-early.o irq-riscv-imsic-platform.o
 obj-$(CONFIG_SIFIVE_PLIC)		+= irq-sifive-plic.o
 obj-$(CONFIG_IMX_IRQSTEER)		+= irq-imx-irqsteer.o
 obj-$(CONFIG_IMX_INTMUX)		+= irq-imx-intmux.o
diff --git a/drivers/irqchip/irq-riscv-imsic-platform.c b/drivers/irqchip/irq-riscv-imsic-platform.c
new file mode 100644
index 000000000000..b78f1b2ee3dc
--- /dev/null
+++ b/drivers/irqchip/irq-riscv-imsic-platform.c
@@ -0,0 +1,280 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+
+#include <linux/bitmap.h>
+#include <linux/cpu.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
+#include <linux/msi.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include <linux/smp.h>
+
+#include "irq-riscv-imsic-state.h"
+
+static int imsic_cpu_page_phys(unsigned int cpu,
+			       unsigned int guest_index,
+			       phys_addr_t *out_msi_pa)
+{
+	struct imsic_global_config *global;
+	struct imsic_local_config *local;
+
+	global = &imsic->global;
+	local = per_cpu_ptr(global->local, cpu);
+
+	if (BIT(global->guest_index_bits) <= guest_index)
+		return -EINVAL;
+
+	if (out_msi_pa)
+		*out_msi_pa = local->msi_pa +
+			      (guest_index * IMSIC_MMIO_PAGE_SZ);
+
+	return 0;
+}
+
+static int imsic_get_cpu(const struct cpumask *mask_val, bool force,
+			 unsigned int *out_target_cpu)
+{
+	unsigned int cpu;
+
+	if (force)
+		cpu = cpumask_first(mask_val);
+	else
+		cpu = cpumask_any_and(mask_val, cpu_online_mask);
+
+	if (cpu >= nr_cpu_ids)
+		return -EINVAL;
+
+	if (out_target_cpu)
+		*out_target_cpu = cpu;
+
+	return 0;
+}
+
+static void imsic_irq_mask(struct irq_data *d)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
+	bitmap_clear(imsic->ids_enabled_bimap, d->hwirq, 1);
+	__imsic_id_disable(d->hwirq);
+	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
+
+	imsic_ids_remote_sync();
+}
+
+static void imsic_irq_unmask(struct irq_data *d)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
+	bitmap_set(imsic->ids_enabled_bimap, d->hwirq, 1);
+	__imsic_id_enable(d->hwirq);
+	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
+
+	imsic_ids_remote_sync();
+}
+
+static void imsic_irq_compose_msi_msg(struct irq_data *d,
+				      struct msi_msg *msg)
+{
+	phys_addr_t msi_addr;
+	unsigned int cpu;
+	int err;
+
+	cpu = imsic_id_get_target(d->hwirq);
+	if (WARN_ON(cpu == UINT_MAX))
+		return;
+
+	err = imsic_cpu_page_phys(cpu, 0, &msi_addr);
+	if (WARN_ON(err))
+		return;
+
+	msg->address_hi = upper_32_bits(msi_addr);
+	msg->address_lo = lower_32_bits(msi_addr);
+	msg->data = d->hwirq;
+}
+
+#ifdef CONFIG_SMP
+static int imsic_irq_set_affinity(struct irq_data *d,
+				  const struct cpumask *mask_val,
+				  bool force)
+{
+	unsigned int target_cpu;
+	int rc;
+
+	rc = imsic_get_cpu(mask_val, force, &target_cpu);
+	if (rc)
+		return rc;
+
+	imsic_id_set_target(d->hwirq, target_cpu);
+	irq_data_update_effective_affinity(d, cpumask_of(target_cpu));
+
+	return IRQ_SET_MASK_OK;
+}
+#endif
+
+static struct irq_chip imsic_irq_base_chip = {
+	.name			= "IMSIC-BASE",
+	.irq_mask		= imsic_irq_mask,
+	.irq_unmask		= imsic_irq_unmask,
+#ifdef CONFIG_SMP
+	.irq_set_affinity	= imsic_irq_set_affinity,
+#endif
+	.irq_compose_msi_msg	= imsic_irq_compose_msi_msg,
+	.flags			= IRQCHIP_SKIP_SET_WAKE |
+				  IRQCHIP_MASK_ON_SUSPEND,
+};
+
+static int imsic_irq_domain_alloc(struct irq_domain *domain,
+				  unsigned int virq,
+				  unsigned int nr_irqs,
+				  void *args)
+{
+	int i, hwirq, err = 0;
+	unsigned int cpu;
+
+	err = imsic_get_cpu(cpu_online_mask, false, &cpu);
+	if (err)
+		return err;
+
+	hwirq = imsic_ids_alloc(get_count_order(nr_irqs));
+	if (hwirq < 0)
+		return hwirq;
+
+	for (i = 0; i < nr_irqs; i++) {
+		imsic_id_set_target(hwirq + i, cpu);
+		irq_domain_set_info(domain, virq + i, hwirq + i,
+				    &imsic_irq_base_chip, imsic,
+				    handle_simple_irq, NULL, NULL);
+		irq_set_noprobe(virq + i);
+		irq_set_affinity(virq + i, cpu_online_mask);
+		/*
+		 * IMSIC does not implement irq_disable() so Linux interrupt
+		 * subsystem will take a lazy approach for disabling an IMSIC
+		 * interrupt. This means IMSIC interrupts are left unmasked
+		 * upon system suspend and interrupts are not processed
+		 * immediately upon system wake up. To tackle this, we disable
+		 * the lazy approach for all IMSIC interrupts.
+		 */
+		irq_set_status_flags(virq + i, IRQ_DISABLE_UNLAZY);
+	}
+
+	return 0;
+}
+
+static void imsic_irq_domain_free(struct irq_domain *domain,
+				  unsigned int virq,
+				  unsigned int nr_irqs)
+{
+	struct irq_data *d = irq_domain_get_irq_data(domain, virq);
+
+	imsic_ids_free(d->hwirq, get_count_order(nr_irqs));
+	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
+}
+
+static const struct irq_domain_ops imsic_base_domain_ops = {
+	.alloc		= imsic_irq_domain_alloc,
+	.free		= imsic_irq_domain_free,
+};
+
+static struct irq_chip imsic_plat_irq_chip = {
+	.name			= "IMSIC-PLAT",
+};
+
+static struct msi_domain_ops imsic_plat_domain_ops = {
+};
+
+static struct msi_domain_info imsic_plat_domain_info = {
+	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
+	.ops	= &imsic_plat_domain_ops,
+	.chip	= &imsic_plat_irq_chip,
+};
+
+static int imsic_irq_domains_init(struct device *dev)
+{
+	/* Create Base IRQ domain */
+	imsic->base_domain = irq_domain_create_tree(dev->fwnode,
+					&imsic_base_domain_ops, imsic);
+	if (!imsic->base_domain) {
+		dev_err(dev, "failed to create IMSIC base domain\n");
+		return -ENOMEM;
+	}
+	irq_domain_update_bus_token(imsic->base_domain, DOMAIN_BUS_NEXUS);
+
+	/* Create Platform MSI domain */
+	imsic->plat_domain = platform_msi_create_irq_domain(dev->fwnode,
+						&imsic_plat_domain_info,
+						imsic->base_domain);
+	if (!imsic->plat_domain) {
+		dev_err(dev, "failed to create IMSIC platform domain\n");
+		irq_domain_remove(imsic->base_domain);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static int imsic_platform_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct imsic_global_config *global;
+	int rc;
+
+	if (!imsic) {
+		dev_err(dev, "early driver not probed\n");
+		return -ENODEV;
+	}
+
+	if (imsic->base_domain) {
+		dev_err(dev, "irq domain already created\n");
+		return -ENODEV;
+	}
+
+	global = &imsic->global;
+
+	/* Initialize IRQ and MSI domains */
+	rc = imsic_irq_domains_init(dev);
+	if (rc) {
+		dev_err(dev, "failed to initialize IRQ and MSI domains\n");
+		return rc;
+	}
+
+	dev_info(dev, "  hart-index-bits: %d,  guest-index-bits: %d\n",
+		 global->hart_index_bits, global->guest_index_bits);
+	dev_info(dev, " group-index-bits: %d, group-index-shift: %d\n",
+		 global->group_index_bits, global->group_index_shift);
+	dev_info(dev, " mapped %d interrupts at base PPN %pa\n",
+		 global->nr_ids, &global->base_addr);
+
+	return 0;
+}
+
+static const struct of_device_id imsic_platform_match[] = {
+	{ .compatible = "riscv,imsics" },
+	{}
+};
+
+static struct platform_driver imsic_platform_driver = {
+	.driver = {
+		.name		= "riscv-imsic",
+		.of_match_table	= imsic_platform_match,
+	},
+	.probe = imsic_platform_probe,
+};
+
+static int __init imsic_platform_init(void)
+{
+	/*
+	 * Register IMSIC driver as early as possible so that IMSIC
+	 * platform device is probed as soon as it is created.
+	 */
+	return platform_driver_register(&imsic_platform_driver);
+}
+core_initcall(imsic_platform_init);
-- 
2.34.1

[PATCH v8 10/16] irqchip/riscv-imsic: Add support for platform MSI irqdomain

[Anup Patel]

The Linux platform MSI support requires a platform MSI irqdomain so
let us add a platform irqchip driver for RISC-V IMSIC which provides
a base IRQ domain and platform MSI domain. This driver assumes that
the IMSIC state is already initialized by the IMSIC early driver.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 drivers/irqchip/Makefile                   |   2 +-
 drivers/irqchip/irq-riscv-imsic-platform.c | 280 +++++++++++++++++++++
 2 files changed, 281 insertions(+), 1 deletion(-)
 create mode 100644 drivers/irqchip/irq-riscv-imsic-platform.c

diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index d714724387ce..abca445a3229 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -95,7 +95,7 @@ obj-$(CONFIG_QCOM_MPM)			+= irq-qcom-mpm.o
 obj-$(CONFIG_CSKY_MPINTC)		+= irq-csky-mpintc.o
 obj-$(CONFIG_CSKY_APB_INTC)		+= irq-csky-apb-intc.o
 obj-$(CONFIG_RISCV_INTC)		+= irq-riscv-intc.o
-obj-$(CONFIG_RISCV_IMSIC)		+= irq-riscv-imsic-state.o irq-riscv-imsic-early.o
+obj-$(CONFIG_RISCV_IMSIC)		+= irq-riscv-imsic-state.o irq-riscv-imsic-early.o irq-riscv-imsic-platform.o
 obj-$(CONFIG_SIFIVE_PLIC)		+= irq-sifive-plic.o
 obj-$(CONFIG_IMX_IRQSTEER)		+= irq-imx-irqsteer.o
 obj-$(CONFIG_IMX_INTMUX)		+= irq-imx-intmux.o
diff --git a/drivers/irqchip/irq-riscv-imsic-platform.c b/drivers/irqchip/irq-riscv-imsic-platform.c
new file mode 100644
index 000000000000..b78f1b2ee3dc
--- /dev/null
+++ b/drivers/irqchip/irq-riscv-imsic-platform.c
@@ -0,0 +1,280 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+
+#include <linux/bitmap.h>
+#include <linux/cpu.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
+#include <linux/msi.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include <linux/smp.h>
+
+#include "irq-riscv-imsic-state.h"
+
+static int imsic_cpu_page_phys(unsigned int cpu,
+			       unsigned int guest_index,
+			       phys_addr_t *out_msi_pa)
+{
+	struct imsic_global_config *global;
+	struct imsic_local_config *local;
+
+	global = &imsic->global;
+	local = per_cpu_ptr(global->local, cpu);
+
+	if (BIT(global->guest_index_bits) <= guest_index)
+		return -EINVAL;
+
+	if (out_msi_pa)
+		*out_msi_pa = local->msi_pa +
+			      (guest_index * IMSIC_MMIO_PAGE_SZ);
+
+	return 0;
+}
+
+static int imsic_get_cpu(const struct cpumask *mask_val, bool force,
+			 unsigned int *out_target_cpu)
+{
+	unsigned int cpu;
+
+	if (force)
+		cpu = cpumask_first(mask_val);
+	else
+		cpu = cpumask_any_and(mask_val, cpu_online_mask);
+
+	if (cpu >= nr_cpu_ids)
+		return -EINVAL;
+
+	if (out_target_cpu)
+		*out_target_cpu = cpu;
+
+	return 0;
+}
+
+static void imsic_irq_mask(struct irq_data *d)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
+	bitmap_clear(imsic->ids_enabled_bimap, d->hwirq, 1);
+	__imsic_id_disable(d->hwirq);
+	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
+
+	imsic_ids_remote_sync();
+}
+
+static void imsic_irq_unmask(struct irq_data *d)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
+	bitmap_set(imsic->ids_enabled_bimap, d->hwirq, 1);
+	__imsic_id_enable(d->hwirq);
+	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
+
+	imsic_ids_remote_sync();
+}
+
+static void imsic_irq_compose_msi_msg(struct irq_data *d,
+				      struct msi_msg *msg)
+{
+	phys_addr_t msi_addr;
+	unsigned int cpu;
+	int err;
+
+	cpu = imsic_id_get_target(d->hwirq);
+	if (WARN_ON(cpu == UINT_MAX))
+		return;
+
+	err = imsic_cpu_page_phys(cpu, 0, &msi_addr);
+	if (WARN_ON(err))
+		return;
+
+	msg->address_hi = upper_32_bits(msi_addr);
+	msg->address_lo = lower_32_bits(msi_addr);
+	msg->data = d->hwirq;
+}
+
+#ifdef CONFIG_SMP
+static int imsic_irq_set_affinity(struct irq_data *d,
+				  const struct cpumask *mask_val,
+				  bool force)
+{
+	unsigned int target_cpu;
+	int rc;
+
+	rc = imsic_get_cpu(mask_val, force, &target_cpu);
+	if (rc)
+		return rc;
+
+	imsic_id_set_target(d->hwirq, target_cpu);
+	irq_data_update_effective_affinity(d, cpumask_of(target_cpu));
+
+	return IRQ_SET_MASK_OK;
+}
+#endif
+
+static struct irq_chip imsic_irq_base_chip = {
+	.name			= "IMSIC-BASE",
+	.irq_mask		= imsic_irq_mask,
+	.irq_unmask		= imsic_irq_unmask,
+#ifdef CONFIG_SMP
+	.irq_set_affinity	= imsic_irq_set_affinity,
+#endif
+	.irq_compose_msi_msg	= imsic_irq_compose_msi_msg,
+	.flags			= IRQCHIP_SKIP_SET_WAKE |
+				  IRQCHIP_MASK_ON_SUSPEND,
+};
+
+static int imsic_irq_domain_alloc(struct irq_domain *domain,
+				  unsigned int virq,
+				  unsigned int nr_irqs,
+				  void *args)
+{
+	int i, hwirq, err = 0;
+	unsigned int cpu;
+
+	err = imsic_get_cpu(cpu_online_mask, false, &cpu);
+	if (err)
+		return err;
+
+	hwirq = imsic_ids_alloc(get_count_order(nr_irqs));
+	if (hwirq < 0)
+		return hwirq;
+
+	for (i = 0; i < nr_irqs; i++) {
+		imsic_id_set_target(hwirq + i, cpu);
+		irq_domain_set_info(domain, virq + i, hwirq + i,
+				    &imsic_irq_base_chip, imsic,
+				    handle_simple_irq, NULL, NULL);
+		irq_set_noprobe(virq + i);
+		irq_set_affinity(virq + i, cpu_online_mask);
+		/*
+		 * IMSIC does not implement irq_disable() so Linux interrupt
+		 * subsystem will take a lazy approach for disabling an IMSIC
+		 * interrupt. This means IMSIC interrupts are left unmasked
+		 * upon system suspend and interrupts are not processed
+		 * immediately upon system wake up. To tackle this, we disable
+		 * the lazy approach for all IMSIC interrupts.
+		 */
+		irq_set_status_flags(virq + i, IRQ_DISABLE_UNLAZY);
+	}
+
+	return 0;
+}
+
+static void imsic_irq_domain_free(struct irq_domain *domain,
+				  unsigned int virq,
+				  unsigned int nr_irqs)
+{
+	struct irq_data *d = irq_domain_get_irq_data(domain, virq);
+
+	imsic_ids_free(d->hwirq, get_count_order(nr_irqs));
+	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
+}
+
+static const struct irq_domain_ops imsic_base_domain_ops = {
+	.alloc		= imsic_irq_domain_alloc,
+	.free		= imsic_irq_domain_free,
+};
+
+static struct irq_chip imsic_plat_irq_chip = {
+	.name			= "IMSIC-PLAT",
+};
+
+static struct msi_domain_ops imsic_plat_domain_ops = {
+};
+
+static struct msi_domain_info imsic_plat_domain_info = {
+	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
+	.ops	= &imsic_plat_domain_ops,
+	.chip	= &imsic_plat_irq_chip,
+};
+
+static int imsic_irq_domains_init(struct device *dev)
+{
+	/* Create Base IRQ domain */
+	imsic->base_domain = irq_domain_create_tree(dev->fwnode,
+					&imsic_base_domain_ops, imsic);
+	if (!imsic->base_domain) {
+		dev_err(dev, "failed to create IMSIC base domain\n");
+		return -ENOMEM;
+	}
+	irq_domain_update_bus_token(imsic->base_domain, DOMAIN_BUS_NEXUS);
+
+	/* Create Platform MSI domain */
+	imsic->plat_domain = platform_msi_create_irq_domain(dev->fwnode,
+						&imsic_plat_domain_info,
+						imsic->base_domain);
+	if (!imsic->plat_domain) {
+		dev_err(dev, "failed to create IMSIC platform domain\n");
+		irq_domain_remove(imsic->base_domain);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static int imsic_platform_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct imsic_global_config *global;
+	int rc;
+
+	if (!imsic) {
+		dev_err(dev, "early driver not probed\n");
+		return -ENODEV;
+	}
+
+	if (imsic->base_domain) {
+		dev_err(dev, "irq domain already created\n");
+		return -ENODEV;
+	}
+
+	global = &imsic->global;
+
+	/* Initialize IRQ and MSI domains */
+	rc = imsic_irq_domains_init(dev);
+	if (rc) {
+		dev_err(dev, "failed to initialize IRQ and MSI domains\n");
+		return rc;
+	}
+
+	dev_info(dev, "  hart-index-bits: %d,  guest-index-bits: %d\n",
+		 global->hart_index_bits, global->guest_index_bits);
+	dev_info(dev, " group-index-bits: %d, group-index-shift: %d\n",
+		 global->group_index_bits, global->group_index_shift);
+	dev_info(dev, " mapped %d interrupts at base PPN %pa\n",
+		 global->nr_ids, &global->base_addr);
+
+	return 0;
+}
+
+static const struct of_device_id imsic_platform_match[] = {
+	{ .compatible = "riscv,imsics" },
+	{}
+};
+
+static struct platform_driver imsic_platform_driver = {
+	.driver = {
+		.name		= "riscv-imsic",
+		.of_match_table	= imsic_platform_match,
+	},
+	.probe = imsic_platform_probe,
+};
+
+static int __init imsic_platform_init(void)
+{
+	/*
+	 * Register IMSIC driver as early as possible so that IMSIC
+	 * platform device is probed as soon as it is created.
+	 */
+	return platform_driver_register(&imsic_platform_driver);
+}
+core_initcall(imsic_platform_init);
-- 
2.34.1


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[PATCH v8 11/16] irqchip/riscv-imsic: Add support for PCI MSI irqdomain

[Anup Patel]

The Linux PCI framework requires it's own dedicated MSI irqdomain so
let us create PCI MSI irqdomain as child of the IMSIC base irqdomain.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 drivers/irqchip/Kconfig                    |  7 ++++
 drivers/irqchip/irq-riscv-imsic-platform.c | 48 ++++++++++++++++++++++
 drivers/irqchip/irq-riscv-imsic-state.h    |  1 +
 3 files changed, 56 insertions(+)

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index ee99aacbefcc..a6aad78076a0 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -551,6 +551,13 @@ config RISCV_IMSIC
 	select IRQ_DOMAIN_HIERARCHY
 	select GENERIC_MSI_IRQ
 
+config RISCV_IMSIC_PCI
+	bool
+	depends on RISCV_IMSIC
+	depends on PCI
+	depends on PCI_MSI
+	default RISCV_IMSIC
+
 config EXYNOS_IRQ_COMBINER
 	bool "Samsung Exynos IRQ combiner support" if COMPILE_TEST
 	depends on (ARCH_EXYNOS && ARM) || COMPILE_TEST
diff --git a/drivers/irqchip/irq-riscv-imsic-platform.c b/drivers/irqchip/irq-riscv-imsic-platform.c
index b78f1b2ee3dc..ff737b4e195f 100644
--- a/drivers/irqchip/irq-riscv-imsic-platform.c
+++ b/drivers/irqchip/irq-riscv-imsic-platform.c
@@ -12,6 +12,7 @@
 #include <linux/irqdomain.h>
 #include <linux/module.h>
 #include <linux/msi.h>
+#include <linux/pci.h>
 #include <linux/platform_device.h>
 #include <linux/spinlock.h>
 #include <linux/smp.h>
@@ -184,6 +185,39 @@ static const struct irq_domain_ops imsic_base_domain_ops = {
 	.free		= imsic_irq_domain_free,
 };
 
+#ifdef CONFIG_RISCV_IMSIC_PCI
+
+static void imsic_pci_mask_irq(struct irq_data *d)
+{
+	pci_msi_mask_irq(d);
+	irq_chip_mask_parent(d);
+}
+
+static void imsic_pci_unmask_irq(struct irq_data *d)
+{
+	pci_msi_unmask_irq(d);
+	irq_chip_unmask_parent(d);
+}
+
+static struct irq_chip imsic_pci_irq_chip = {
+	.name			= "IMSIC-PCI",
+	.irq_mask		= imsic_pci_mask_irq,
+	.irq_unmask		= imsic_pci_unmask_irq,
+	.irq_eoi		= irq_chip_eoi_parent,
+};
+
+static struct msi_domain_ops imsic_pci_domain_ops = {
+};
+
+static struct msi_domain_info imsic_pci_domain_info = {
+	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
+		   MSI_FLAG_PCI_MSIX | MSI_FLAG_MULTI_PCI_MSI),
+	.ops	= &imsic_pci_domain_ops,
+	.chip	= &imsic_pci_irq_chip,
+};
+
+#endif
+
 static struct irq_chip imsic_plat_irq_chip = {
 	.name			= "IMSIC-PLAT",
 };
@@ -208,12 +242,26 @@ static int imsic_irq_domains_init(struct device *dev)
 	}
 	irq_domain_update_bus_token(imsic->base_domain, DOMAIN_BUS_NEXUS);
 
+#ifdef CONFIG_RISCV_IMSIC_PCI
+	/* Create PCI MSI domain */
+	imsic->pci_domain = pci_msi_create_irq_domain(dev->fwnode,
+						&imsic_pci_domain_info,
+						imsic->base_domain);
+	if (!imsic->pci_domain) {
+		dev_err(dev, "failed to create IMSIC PCI domain\n");
+		irq_domain_remove(imsic->base_domain);
+		return -ENOMEM;
+	}
+#endif
+
 	/* Create Platform MSI domain */
 	imsic->plat_domain = platform_msi_create_irq_domain(dev->fwnode,
 						&imsic_plat_domain_info,
 						imsic->base_domain);
 	if (!imsic->plat_domain) {
 		dev_err(dev, "failed to create IMSIC platform domain\n");
+		if (imsic->pci_domain)
+			irq_domain_remove(imsic->pci_domain);
 		irq_domain_remove(imsic->base_domain);
 		return -ENOMEM;
 	}
diff --git a/drivers/irqchip/irq-riscv-imsic-state.h b/drivers/irqchip/irq-riscv-imsic-state.h
index 3170018949a8..ff3c377b9b33 100644
--- a/drivers/irqchip/irq-riscv-imsic-state.h
+++ b/drivers/irqchip/irq-riscv-imsic-state.h
@@ -31,6 +31,7 @@ struct imsic_priv {
 
 	/* IRQ domains (created by platform driver) */
 	struct irq_domain *base_domain;
+	struct irq_domain *pci_domain;
 	struct irq_domain *plat_domain;
 };
 
-- 
2.34.1

[PATCH v8 11/16] irqchip/riscv-imsic: Add support for PCI MSI irqdomain

[Anup Patel]

The Linux PCI framework requires it's own dedicated MSI irqdomain so
let us create PCI MSI irqdomain as child of the IMSIC base irqdomain.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 drivers/irqchip/Kconfig                    |  7 ++++
 drivers/irqchip/irq-riscv-imsic-platform.c | 48 ++++++++++++++++++++++
 drivers/irqchip/irq-riscv-imsic-state.h    |  1 +
 3 files changed, 56 insertions(+)

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index ee99aacbefcc..a6aad78076a0 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -551,6 +551,13 @@ config RISCV_IMSIC
 	select IRQ_DOMAIN_HIERARCHY
 	select GENERIC_MSI_IRQ
 
+config RISCV_IMSIC_PCI
+	bool
+	depends on RISCV_IMSIC
+	depends on PCI
+	depends on PCI_MSI
+	default RISCV_IMSIC
+
 config EXYNOS_IRQ_COMBINER
 	bool "Samsung Exynos IRQ combiner support" if COMPILE_TEST
 	depends on (ARCH_EXYNOS && ARM) || COMPILE_TEST
diff --git a/drivers/irqchip/irq-riscv-imsic-platform.c b/drivers/irqchip/irq-riscv-imsic-platform.c
index b78f1b2ee3dc..ff737b4e195f 100644
--- a/drivers/irqchip/irq-riscv-imsic-platform.c
+++ b/drivers/irqchip/irq-riscv-imsic-platform.c
@@ -12,6 +12,7 @@
 #include <linux/irqdomain.h>
 #include <linux/module.h>
 #include <linux/msi.h>
+#include <linux/pci.h>
 #include <linux/platform_device.h>
 #include <linux/spinlock.h>
 #include <linux/smp.h>
@@ -184,6 +185,39 @@ static const struct irq_domain_ops imsic_base_domain_ops = {
 	.free		= imsic_irq_domain_free,
 };
 
+#ifdef CONFIG_RISCV_IMSIC_PCI
+
+static void imsic_pci_mask_irq(struct irq_data *d)
+{
+	pci_msi_mask_irq(d);
+	irq_chip_mask_parent(d);
+}
+
+static void imsic_pci_unmask_irq(struct irq_data *d)
+{
+	pci_msi_unmask_irq(d);
+	irq_chip_unmask_parent(d);
+}
+
+static struct irq_chip imsic_pci_irq_chip = {
+	.name			= "IMSIC-PCI",
+	.irq_mask		= imsic_pci_mask_irq,
+	.irq_unmask		= imsic_pci_unmask_irq,
+	.irq_eoi		= irq_chip_eoi_parent,
+};
+
+static struct msi_domain_ops imsic_pci_domain_ops = {
+};
+
+static struct msi_domain_info imsic_pci_domain_info = {
+	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
+		   MSI_FLAG_PCI_MSIX | MSI_FLAG_MULTI_PCI_MSI),
+	.ops	= &imsic_pci_domain_ops,
+	.chip	= &imsic_pci_irq_chip,
+};
+
+#endif
+
 static struct irq_chip imsic_plat_irq_chip = {
 	.name			= "IMSIC-PLAT",
 };
@@ -208,12 +242,26 @@ static int imsic_irq_domains_init(struct device *dev)
 	}
 	irq_domain_update_bus_token(imsic->base_domain, DOMAIN_BUS_NEXUS);
 
+#ifdef CONFIG_RISCV_IMSIC_PCI
+	/* Create PCI MSI domain */
+	imsic->pci_domain = pci_msi_create_irq_domain(dev->fwnode,
+						&imsic_pci_domain_info,
+						imsic->base_domain);
+	if (!imsic->pci_domain) {
+		dev_err(dev, "failed to create IMSIC PCI domain\n");
+		irq_domain_remove(imsic->base_domain);
+		return -ENOMEM;
+	}
+#endif
+
 	/* Create Platform MSI domain */
 	imsic->plat_domain = platform_msi_create_irq_domain(dev->fwnode,
 						&imsic_plat_domain_info,
 						imsic->base_domain);
 	if (!imsic->plat_domain) {
 		dev_err(dev, "failed to create IMSIC platform domain\n");
+		if (imsic->pci_domain)
+			irq_domain_remove(imsic->pci_domain);
 		irq_domain_remove(imsic->base_domain);
 		return -ENOMEM;
 	}
diff --git a/drivers/irqchip/irq-riscv-imsic-state.h b/drivers/irqchip/irq-riscv-imsic-state.h
index 3170018949a8..ff3c377b9b33 100644
--- a/drivers/irqchip/irq-riscv-imsic-state.h
+++ b/drivers/irqchip/irq-riscv-imsic-state.h
@@ -31,6 +31,7 @@ struct imsic_priv {
 
 	/* IRQ domains (created by platform driver) */
 	struct irq_domain *base_domain;
+	struct irq_domain *pci_domain;
 	struct irq_domain *plat_domain;
 };
 
-- 
2.34.1


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[PATCH v8 12/16] dt-bindings: interrupt-controller: Add RISC-V advanced PLIC

[Anup Patel]

We add DT bindings document for RISC-V advanced platform level interrupt
controller (APLIC) defined by the RISC-V advanced interrupt architecture
(AIA) specification.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
---
 .../interrupt-controller/riscv,aplic.yaml     | 172 ++++++++++++++++++
 1 file changed, 172 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/interrupt-controller/riscv,aplic.yaml

diff --git a/Documentation/devicetree/bindings/interrupt-controller/riscv,aplic.yaml b/Documentation/devicetree/bindings/interrupt-controller/riscv,aplic.yaml
new file mode 100644
index 000000000000..190a6499c932
--- /dev/null
+++ b/Documentation/devicetree/bindings/interrupt-controller/riscv,aplic.yaml
@@ -0,0 +1,172 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/interrupt-controller/riscv,aplic.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: RISC-V Advanced Platform Level Interrupt Controller (APLIC)
+
+maintainers:
+  - Anup Patel <anup@brainfault.org>
+
+description:
+  The RISC-V advanced interrupt architecture (AIA) defines an advanced
+  platform level interrupt controller (APLIC) for handling wired interrupts
+  in a RISC-V platform. The RISC-V AIA specification can be found at
+  https://github.com/riscv/riscv-aia.
+
+  The RISC-V APLIC is implemented as hierarchical APLIC domains where all
+  interrupt sources connect to the root APLIC domain and a parent APLIC
+  domain can delegate interrupt sources to it's child APLIC domains. There
+  is one device tree node for each APLIC domain.
+
+allOf:
+  - $ref: /schemas/interrupt-controller.yaml#
+
+properties:
+  compatible:
+    items:
+      - enum:
+          - qemu,aplic
+      - const: riscv,aplic
+
+  reg:
+    maxItems: 1
+
+  interrupt-controller: true
+
+  "#interrupt-cells":
+    const: 2
+
+  interrupts-extended:
+    minItems: 1
+    maxItems: 16384
+    description:
+      Given APLIC domain directly injects external interrupts to a set of
+      RISC-V HARTS (or CPUs). Each node pointed to should be a riscv,cpu-intc
+      node, which has a CPU node (i.e. RISC-V HART) as parent.
+
+  msi-parent:
+    description:
+      Given APLIC domain forwards wired interrupts as MSIs to a AIA incoming
+      message signaled interrupt controller (IMSIC). If both "msi-parent" and
+      "interrupts-extended" properties are present then it means the APLIC
+      domain supports both MSI mode and Direct mode in HW. In this case, the
+      APLIC driver has to choose between MSI mode or Direct mode.
+
+  riscv,num-sources:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 1
+    maximum: 1023
+    description:
+      Specifies the number of wired interrupt sources supported by this
+      APLIC domain.
+
+  riscv,children:
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+    minItems: 1
+    maxItems: 1024
+    items:
+      maxItems: 1
+    description:
+      A list of child APLIC domains for the given APLIC domain. Each child
+      APLIC domain is assigned a child index in increasing order, with the
+      first child APLIC domain assigned child index 0. The APLIC domain child
+      index is used by firmware to delegate interrupts from the given APLIC
+      domain to a particular child APLIC domain.
+
+  riscv,delegation:
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+    minItems: 1
+    maxItems: 1024
+    items:
+      items:
+        - description: child APLIC domain phandle
+        - description: first interrupt number of the parent APLIC domain (inclusive)
+        - description: last interrupt number of the parent APLIC domain (inclusive)
+    description:
+      A interrupt delegation list where each entry is a triple consisting
+      of child APLIC domain phandle, first interrupt number of the parent
+      APLIC domain, and last interrupt number of the parent APLIC domain.
+      Firmware must configure interrupt delegation registers based on
+      interrupt delegation list.
+
+dependencies:
+  riscv,delegation: [ "riscv,children" ]
+
+required:
+  - compatible
+  - reg
+  - interrupt-controller
+  - "#interrupt-cells"
+  - riscv,num-sources
+
+anyOf:
+  - required:
+      - interrupts-extended
+  - required:
+      - msi-parent
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    // Example 1 (APLIC domains directly injecting interrupt to HARTs):
+
+    interrupt-controller@c000000 {
+      compatible = "qemu,aplic", "riscv,aplic";
+      interrupts-extended = <&cpu1_intc 11>,
+                            <&cpu2_intc 11>,
+                            <&cpu3_intc 11>,
+                            <&cpu4_intc 11>;
+      reg = <0xc000000 0x4080>;
+      interrupt-controller;
+      #interrupt-cells = <2>;
+      riscv,num-sources = <63>;
+      riscv,children = <&aplic1>, <&aplic2>;
+      riscv,delegation = <&aplic1 1 63>;
+    };
+
+    aplic1: interrupt-controller@d000000 {
+      compatible = "qemu,aplic", "riscv,aplic";
+      interrupts-extended = <&cpu1_intc 9>,
+                            <&cpu2_intc 9>;
+      reg = <0xd000000 0x4080>;
+      interrupt-controller;
+      #interrupt-cells = <2>;
+      riscv,num-sources = <63>;
+    };
+
+    aplic2: interrupt-controller@e000000 {
+      compatible = "qemu,aplic", "riscv,aplic";
+      interrupts-extended = <&cpu3_intc 9>,
+                            <&cpu4_intc 9>;
+      reg = <0xe000000 0x4080>;
+      interrupt-controller;
+      #interrupt-cells = <2>;
+      riscv,num-sources = <63>;
+    };
+
+  - |
+    // Example 2 (APLIC domains forwarding interrupts as MSIs):
+
+    interrupt-controller@c000000 {
+      compatible = "qemu,aplic", "riscv,aplic";
+      msi-parent = <&imsic_mlevel>;
+      reg = <0xc000000 0x4000>;
+      interrupt-controller;
+      #interrupt-cells = <2>;
+      riscv,num-sources = <63>;
+      riscv,children = <&aplic3>;
+      riscv,delegation = <&aplic3 1 63>;
+    };
+
+    aplic3: interrupt-controller@d000000 {
+      compatible = "qemu,aplic", "riscv,aplic";
+      msi-parent = <&imsic_slevel>;
+      reg = <0xd000000 0x4000>;
+      interrupt-controller;
+      #interrupt-cells = <2>;
+      riscv,num-sources = <63>;
+    };
+...
-- 
2.34.1

[PATCH v8 12/16] dt-bindings: interrupt-controller: Add RISC-V advanced PLIC

[Anup Patel]

We add DT bindings document for RISC-V advanced platform level interrupt
controller (APLIC) defined by the RISC-V advanced interrupt architecture
(AIA) specification.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
---
 .../interrupt-controller/riscv,aplic.yaml     | 172 ++++++++++++++++++
 1 file changed, 172 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/interrupt-controller/riscv,aplic.yaml

diff --git a/Documentation/devicetree/bindings/interrupt-controller/riscv,aplic.yaml b/Documentation/devicetree/bindings/interrupt-controller/riscv,aplic.yaml
new file mode 100644
index 000000000000..190a6499c932
--- /dev/null
+++ b/Documentation/devicetree/bindings/interrupt-controller/riscv,aplic.yaml
@@ -0,0 +1,172 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/interrupt-controller/riscv,aplic.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: RISC-V Advanced Platform Level Interrupt Controller (APLIC)
+
+maintainers:
+  - Anup Patel <anup@brainfault.org>
+
+description:
+  The RISC-V advanced interrupt architecture (AIA) defines an advanced
+  platform level interrupt controller (APLIC) for handling wired interrupts
+  in a RISC-V platform. The RISC-V AIA specification can be found at
+  https://github.com/riscv/riscv-aia.
+
+  The RISC-V APLIC is implemented as hierarchical APLIC domains where all
+  interrupt sources connect to the root APLIC domain and a parent APLIC
+  domain can delegate interrupt sources to it's child APLIC domains. There
+  is one device tree node for each APLIC domain.
+
+allOf:
+  - $ref: /schemas/interrupt-controller.yaml#
+
+properties:
+  compatible:
+    items:
+      - enum:
+          - qemu,aplic
+      - const: riscv,aplic
+
+  reg:
+    maxItems: 1
+
+  interrupt-controller: true
+
+  "#interrupt-cells":
+    const: 2
+
+  interrupts-extended:
+    minItems: 1
+    maxItems: 16384
+    description:
+      Given APLIC domain directly injects external interrupts to a set of
+      RISC-V HARTS (or CPUs). Each node pointed to should be a riscv,cpu-intc
+      node, which has a CPU node (i.e. RISC-V HART) as parent.
+
+  msi-parent:
+    description:
+      Given APLIC domain forwards wired interrupts as MSIs to a AIA incoming
+      message signaled interrupt controller (IMSIC). If both "msi-parent" and
+      "interrupts-extended" properties are present then it means the APLIC
+      domain supports both MSI mode and Direct mode in HW. In this case, the
+      APLIC driver has to choose between MSI mode or Direct mode.
+
+  riscv,num-sources:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 1
+    maximum: 1023
+    description:
+      Specifies the number of wired interrupt sources supported by this
+      APLIC domain.
+
+  riscv,children:
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+    minItems: 1
+    maxItems: 1024
+    items:
+      maxItems: 1
+    description:
+      A list of child APLIC domains for the given APLIC domain. Each child
+      APLIC domain is assigned a child index in increasing order, with the
+      first child APLIC domain assigned child index 0. The APLIC domain child
+      index is used by firmware to delegate interrupts from the given APLIC
+      domain to a particular child APLIC domain.
+
+  riscv,delegation:
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+    minItems: 1
+    maxItems: 1024
+    items:
+      items:
+        - description: child APLIC domain phandle
+        - description: first interrupt number of the parent APLIC domain (inclusive)
+        - description: last interrupt number of the parent APLIC domain (inclusive)
+    description:
+      A interrupt delegation list where each entry is a triple consisting
+      of child APLIC domain phandle, first interrupt number of the parent
+      APLIC domain, and last interrupt number of the parent APLIC domain.
+      Firmware must configure interrupt delegation registers based on
+      interrupt delegation list.
+
+dependencies:
+  riscv,delegation: [ "riscv,children" ]
+
+required:
+  - compatible
+  - reg
+  - interrupt-controller
+  - "#interrupt-cells"
+  - riscv,num-sources
+
+anyOf:
+  - required:
+      - interrupts-extended
+  - required:
+      - msi-parent
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    // Example 1 (APLIC domains directly injecting interrupt to HARTs):
+
+    interrupt-controller@c000000 {
+      compatible = "qemu,aplic", "riscv,aplic";
+      interrupts-extended = <&cpu1_intc 11>,
+                            <&cpu2_intc 11>,
+                            <&cpu3_intc 11>,
+                            <&cpu4_intc 11>;
+      reg = <0xc000000 0x4080>;
+      interrupt-controller;
+      #interrupt-cells = <2>;
+      riscv,num-sources = <63>;
+      riscv,children = <&aplic1>, <&aplic2>;
+      riscv,delegation = <&aplic1 1 63>;
+    };
+
+    aplic1: interrupt-controller@d000000 {
+      compatible = "qemu,aplic", "riscv,aplic";
+      interrupts-extended = <&cpu1_intc 9>,
+                            <&cpu2_intc 9>;
+      reg = <0xd000000 0x4080>;
+      interrupt-controller;
+      #interrupt-cells = <2>;
+      riscv,num-sources = <63>;
+    };
+
+    aplic2: interrupt-controller@e000000 {
+      compatible = "qemu,aplic", "riscv,aplic";
+      interrupts-extended = <&cpu3_intc 9>,
+                            <&cpu4_intc 9>;
+      reg = <0xe000000 0x4080>;
+      interrupt-controller;
+      #interrupt-cells = <2>;
+      riscv,num-sources = <63>;
+    };
+
+  - |
+    // Example 2 (APLIC domains forwarding interrupts as MSIs):
+
+    interrupt-controller@c000000 {
+      compatible = "qemu,aplic", "riscv,aplic";
+      msi-parent = <&imsic_mlevel>;
+      reg = <0xc000000 0x4000>;
+      interrupt-controller;
+      #interrupt-cells = <2>;
+      riscv,num-sources = <63>;
+      riscv,children = <&aplic3>;
+      riscv,delegation = <&aplic3 1 63>;
+    };
+
+    aplic3: interrupt-controller@d000000 {
+      compatible = "qemu,aplic", "riscv,aplic";
+      msi-parent = <&imsic_slevel>;
+      reg = <0xd000000 0x4000>;
+      interrupt-controller;
+      #interrupt-cells = <2>;
+      riscv,num-sources = <63>;
+    };
+...
-- 
2.34.1


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[PATCH v8 13/16] irqchip: Add RISC-V advanced PLIC driver for direct-mode

[Anup Patel]

The RISC-V advanced interrupt architecture (AIA) specification defines
advanced platform-level interrupt controller (APLIC) which has two modes
of operation: 1) Direct mode and 2) MSI mode.
(For more details, refer https://github.com/riscv/riscv-aia)

In APLIC direct-mode, wired interrupts are forwared to CPUs (or HARTs)
as a local external interrupt.

We add a platform irqchip driver for the RISC-V APLIC direct-mode to
support RISC-V platforms having only wired interrupts.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 drivers/irqchip/Kconfig                  |   5 +
 drivers/irqchip/Makefile                 |   1 +
 drivers/irqchip/irq-riscv-aplic-direct.c | 326 +++++++++++++++++++++++
 drivers/irqchip/irq-riscv-aplic-main.c   | 240 +++++++++++++++++
 drivers/irqchip/irq-riscv-aplic-main.h   |  45 ++++
 include/linux/irqchip/riscv-aplic.h      | 119 +++++++++
 6 files changed, 736 insertions(+)
 create mode 100644 drivers/irqchip/irq-riscv-aplic-direct.c
 create mode 100644 drivers/irqchip/irq-riscv-aplic-main.c
 create mode 100644 drivers/irqchip/irq-riscv-aplic-main.h
 create mode 100644 include/linux/irqchip/riscv-aplic.h

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index a6aad78076a0..44c455084d09 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -545,6 +545,11 @@ config SIFIVE_PLIC
 	select IRQ_DOMAIN_HIERARCHY
 	select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
 
+config RISCV_APLIC
+	bool
+	depends on RISCV
+	select IRQ_DOMAIN_HIERARCHY
+
 config RISCV_IMSIC
 	bool
 	depends on RISCV
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index abca445a3229..7f8289790ed8 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -95,6 +95,7 @@ obj-$(CONFIG_QCOM_MPM)			+= irq-qcom-mpm.o
 obj-$(CONFIG_CSKY_MPINTC)		+= irq-csky-mpintc.o
 obj-$(CONFIG_CSKY_APB_INTC)		+= irq-csky-apb-intc.o
 obj-$(CONFIG_RISCV_INTC)		+= irq-riscv-intc.o
+obj-$(CONFIG_RISCV_APLIC)		+= irq-riscv-aplic-main.o irq-riscv-aplic-direct.o
 obj-$(CONFIG_RISCV_IMSIC)		+= irq-riscv-imsic-state.o irq-riscv-imsic-early.o irq-riscv-imsic-platform.o
 obj-$(CONFIG_SIFIVE_PLIC)		+= irq-sifive-plic.o
 obj-$(CONFIG_IMX_IRQSTEER)		+= irq-imx-irqsteer.o
diff --git a/drivers/irqchip/irq-riscv-aplic-direct.c b/drivers/irqchip/irq-riscv-aplic-direct.c
new file mode 100644
index 000000000000..e36d655a1490
--- /dev/null
+++ b/drivers/irqchip/irq-riscv-aplic-direct.c
@@ -0,0 +1,326 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+
+#include <linux/bitops.h>
+#include <linux/cpu.h>
+#include <linux/interrupt.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqchip/riscv-aplic.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/printk.h>
+#include <linux/smp.h>
+
+#include "irq-riscv-aplic-main.h"
+
+#define APLIC_DISABLE_IDELIVERY		0
+#define APLIC_ENABLE_IDELIVERY		1
+#define APLIC_DISABLE_ITHRESHOLD	1
+#define APLIC_ENABLE_ITHRESHOLD		0
+
+struct aplic_direct {
+	struct aplic_priv	priv;
+	struct irq_domain	*irqdomain;
+	struct cpumask		lmask;
+};
+
+struct aplic_idc {
+	unsigned int		hart_index;
+	void __iomem		*regs;
+	struct aplic_direct	*direct;
+};
+
+static unsigned int aplic_direct_parent_irq;
+static DEFINE_PER_CPU(struct aplic_idc, aplic_idcs);
+
+static void aplic_direct_irq_eoi(struct irq_data *d)
+{
+	/*
+	 * The fasteoi_handler requires irq_eoi() callback hence
+	 * provide a dummy handler.
+	 */
+}
+
+#ifdef CONFIG_SMP
+static int aplic_direct_set_affinity(struct irq_data *d,
+				  const struct cpumask *mask_val, bool force)
+{
+	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
+	struct aplic_direct *direct =
+			container_of(priv, struct aplic_direct, priv);
+	struct aplic_idc *idc;
+	unsigned int cpu, val;
+	struct cpumask amask;
+	void __iomem *target;
+
+	cpumask_and(&amask, &direct->lmask, mask_val);
+
+	if (force)
+		cpu = cpumask_first(&amask);
+	else
+		cpu = cpumask_any_and(&amask, cpu_online_mask);
+
+	if (cpu >= nr_cpu_ids)
+		return -EINVAL;
+
+	idc = per_cpu_ptr(&aplic_idcs, cpu);
+	target = priv->regs + APLIC_TARGET_BASE;
+	target += (d->hwirq - 1) * sizeof(u32);
+	val = idc->hart_index & APLIC_TARGET_HART_IDX_MASK;
+	val <<= APLIC_TARGET_HART_IDX_SHIFT;
+	val |= APLIC_DEFAULT_PRIORITY;
+	writel(val, target);
+
+	irq_data_update_effective_affinity(d, cpumask_of(cpu));
+
+	return IRQ_SET_MASK_OK_DONE;
+}
+#endif
+
+static struct irq_chip aplic_direct_chip = {
+	.name		= "APLIC-DIRECT",
+	.irq_mask	= aplic_irq_mask,
+	.irq_unmask	= aplic_irq_unmask,
+	.irq_set_type	= aplic_irq_set_type,
+	.irq_eoi	= aplic_direct_irq_eoi,
+#ifdef CONFIG_SMP
+	.irq_set_affinity = aplic_direct_set_affinity,
+#endif
+	.flags		= IRQCHIP_SET_TYPE_MASKED |
+			  IRQCHIP_SKIP_SET_WAKE |
+			  IRQCHIP_MASK_ON_SUSPEND,
+};
+
+static int aplic_direct_irqdomain_translate(struct irq_domain *d,
+					 struct irq_fwspec *fwspec,
+					 unsigned long *hwirq,
+					 unsigned int *type)
+{
+	struct aplic_priv *priv = d->host_data;
+
+	return aplic_irqdomain_translate(fwspec, priv->gsi_base,
+					 hwirq, type);
+}
+
+static int aplic_direct_irqdomain_alloc(struct irq_domain *domain,
+				     unsigned int virq, unsigned int nr_irqs,
+				     void *arg)
+{
+	int i, ret;
+	unsigned int type;
+	irq_hw_number_t hwirq;
+	struct irq_fwspec *fwspec = arg;
+	struct aplic_priv *priv = domain->host_data;
+	struct aplic_direct *direct =
+			container_of(priv, struct aplic_direct, priv);
+
+	ret = aplic_irqdomain_translate(fwspec, priv->gsi_base,
+					&hwirq, &type);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < nr_irqs; i++) {
+		irq_domain_set_info(domain, virq + i, hwirq + i,
+				    &aplic_direct_chip, priv,
+				    handle_fasteoi_irq, NULL, NULL);
+		irq_set_affinity(virq + i, &direct->lmask);
+		/* See the reason described in aplic_msi_irqdomain_alloc() */
+		irq_set_status_flags(virq + i, IRQ_DISABLE_UNLAZY);
+	}
+
+	return 0;
+}
+
+static const struct irq_domain_ops aplic_direct_irqdomain_ops = {
+	.translate	= aplic_direct_irqdomain_translate,
+	.alloc		= aplic_direct_irqdomain_alloc,
+	.free		= irq_domain_free_irqs_top,
+};
+
+/*
+ * To handle an APLIC direct interrupts, we just read the CLAIMI register
+ * which will return highest priority pending interrupt and clear the
+ * pending bit of the interrupt. This process is repeated until CLAIMI
+ * register return zero value.
+ */
+static void aplic_direct_handle_irq(struct irq_desc *desc)
+{
+	struct aplic_idc *idc = this_cpu_ptr(&aplic_idcs);
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	struct irq_domain *irqdomain = idc->direct->irqdomain;
+	irq_hw_number_t hw_irq;
+	int irq;
+
+	chained_irq_enter(chip, desc);
+
+	while ((hw_irq = readl(idc->regs + APLIC_IDC_CLAIMI))) {
+		hw_irq = hw_irq >> APLIC_IDC_TOPI_ID_SHIFT;
+		irq = irq_find_mapping(irqdomain, hw_irq);
+
+		if (unlikely(irq <= 0))
+			dev_warn_ratelimited(idc->direct->priv.dev,
+					     "hw_irq %lu mapping not found\n",
+					     hw_irq);
+		else
+			generic_handle_irq(irq);
+	}
+
+	chained_irq_exit(chip, desc);
+}
+
+static void aplic_idc_set_delivery(struct aplic_idc *idc, bool en)
+{
+	u32 de = (en) ? APLIC_ENABLE_IDELIVERY : APLIC_DISABLE_IDELIVERY;
+	u32 th = (en) ? APLIC_ENABLE_ITHRESHOLD : APLIC_DISABLE_ITHRESHOLD;
+
+	/* Priority must be less than threshold for interrupt triggering */
+	writel(th, idc->regs + APLIC_IDC_ITHRESHOLD);
+
+	/* Delivery must be set to 1 for interrupt triggering */
+	writel(de, idc->regs + APLIC_IDC_IDELIVERY);
+}
+
+static int aplic_direct_dying_cpu(unsigned int cpu)
+{
+	if (aplic_direct_parent_irq)
+		disable_percpu_irq(aplic_direct_parent_irq);
+
+	return 0;
+}
+
+static int aplic_direct_starting_cpu(unsigned int cpu)
+{
+	if (aplic_direct_parent_irq)
+		enable_percpu_irq(aplic_direct_parent_irq,
+				irq_get_trigger_type(aplic_direct_parent_irq));
+
+	return 0;
+}
+
+int aplic_direct_setup(struct device *dev, void __iomem *regs)
+{
+	int i, j, rc, cpu, setup_count = 0;
+	struct fwnode_reference_args parent;
+	struct aplic_direct *direct;
+	struct aplic_priv *priv;
+	struct irq_domain *domain;
+	unsigned long hartid;
+	struct aplic_idc *idc;
+	u32 val;
+
+	direct = kzalloc(sizeof(*direct), GFP_KERNEL);
+	if (!direct)
+		return -ENOMEM;
+	priv = &direct->priv;
+
+	rc = aplic_setup_priv(priv, dev, regs);
+	if (rc) {
+		dev_err(dev, "failed to create APLIC context\n");
+		kfree(direct);
+		return rc;
+	}
+
+	/* Setup per-CPU IDC and target CPU mask */
+	for (i = 0; i < priv->nr_idcs; i++) {
+		rc = fwnode_property_get_reference_args(dev->fwnode,
+				"interrupts-extended", "#interrupt-cells",
+				0, i, &parent);
+		if (rc) {
+			dev_warn(dev, "parent irq for IDC%d not found\n", i);
+			continue;
+		}
+
+		/*
+		 * Skip interrupts other than external interrupts for
+		 * current privilege level.
+		 */
+		if (parent.args[0] != RV_IRQ_EXT)
+			continue;
+
+		rc = riscv_get_intc_hartid(parent.fwnode, &hartid);
+		if (rc) {
+			dev_warn(dev, "invalid hartid for IDC%d\n", i);
+			continue;
+		}
+
+		cpu = riscv_hartid_to_cpuid(hartid);
+		if (cpu < 0) {
+			dev_warn(dev, "invalid cpuid for IDC%d\n", i);
+			continue;
+		}
+
+		cpumask_set_cpu(cpu, &direct->lmask);
+
+		idc = per_cpu_ptr(&aplic_idcs, cpu);
+		idc->hart_index = i;
+		idc->regs = priv->regs + APLIC_IDC_BASE + i * APLIC_IDC_SIZE;
+		idc->direct = direct;
+
+		aplic_idc_set_delivery(idc, true);
+
+		/*
+		 * Boot cpu might not have APLIC hart_index = 0 so check
+		 * and update target registers of all interrupts.
+		 */
+		if (cpu == smp_processor_id() && idc->hart_index) {
+			val = idc->hart_index & APLIC_TARGET_HART_IDX_MASK;
+			val <<= APLIC_TARGET_HART_IDX_SHIFT;
+			val |= APLIC_DEFAULT_PRIORITY;
+			for (j = 1; j <= priv->nr_irqs; j++)
+				writel(val, priv->regs + APLIC_TARGET_BASE +
+					    (j - 1) * sizeof(u32));
+		}
+
+		setup_count++;
+	}
+
+	/* Find parent domain and register chained handler */
+	domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
+					  DOMAIN_BUS_ANY);
+	if (!aplic_direct_parent_irq && domain) {
+		aplic_direct_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT);
+		if (aplic_direct_parent_irq) {
+			irq_set_chained_handler(aplic_direct_parent_irq,
+						aplic_direct_handle_irq);
+
+			/*
+			 * Setup CPUHP notifier to enable parent
+			 * interrupt on all CPUs
+			 */
+			cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
+					  "irqchip/riscv/aplic:starting",
+					  aplic_direct_starting_cpu,
+					  aplic_direct_dying_cpu);
+		}
+	}
+
+	/* Fail if we were not able to setup IDC for any CPU */
+	if (!setup_count) {
+		kfree(direct);
+		return -ENODEV;
+	}
+
+	/* Setup global config and interrupt delivery */
+	aplic_init_hw_global(priv, false);
+
+	/* Create irq domain instance for the APLIC */
+	direct->irqdomain = irq_domain_create_linear(dev->fwnode,
+						   priv->nr_irqs + 1,
+						   &aplic_direct_irqdomain_ops,
+						   priv);
+	if (!direct->irqdomain) {
+		dev_err(dev, "failed to create direct irq domain\n");
+		kfree(direct);
+		return -ENOMEM;
+	}
+
+	/* Advertise the interrupt controller */
+	dev_info(dev, "%d interrupts directly connected to %d CPUs\n",
+		 priv->nr_irqs, priv->nr_idcs);
+
+	return 0;
+}
diff --git a/drivers/irqchip/irq-riscv-aplic-main.c b/drivers/irqchip/irq-riscv-aplic-main.c
new file mode 100644
index 000000000000..d62a096774c4
--- /dev/null
+++ b/drivers/irqchip/irq-riscv-aplic-main.c
@@ -0,0 +1,240 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+
+#include <linux/printk.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/irqchip/riscv-aplic.h>
+
+#include "irq-riscv-aplic-main.h"
+
+void aplic_irq_unmask(struct irq_data *d)
+{
+	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
+
+	writel(d->hwirq, priv->regs + APLIC_SETIENUM);
+}
+
+void aplic_irq_mask(struct irq_data *d)
+{
+	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
+
+	writel(d->hwirq, priv->regs + APLIC_CLRIENUM);
+}
+
+int aplic_irq_set_type(struct irq_data *d, unsigned int type)
+{
+	u32 val = 0;
+	void __iomem *sourcecfg;
+	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
+
+	switch (type) {
+	case IRQ_TYPE_NONE:
+		val = APLIC_SOURCECFG_SM_INACTIVE;
+		break;
+	case IRQ_TYPE_LEVEL_LOW:
+		val = APLIC_SOURCECFG_SM_LEVEL_LOW;
+		break;
+	case IRQ_TYPE_LEVEL_HIGH:
+		val = APLIC_SOURCECFG_SM_LEVEL_HIGH;
+		break;
+	case IRQ_TYPE_EDGE_FALLING:
+		val = APLIC_SOURCECFG_SM_EDGE_FALL;
+		break;
+	case IRQ_TYPE_EDGE_RISING:
+		val = APLIC_SOURCECFG_SM_EDGE_RISE;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	sourcecfg = priv->regs + APLIC_SOURCECFG_BASE;
+	sourcecfg += (d->hwirq - 1) * sizeof(u32);
+	writel(val, sourcecfg);
+
+	return 0;
+}
+
+int aplic_irqdomain_translate(struct irq_fwspec *fwspec, u32 gsi_base,
+			      unsigned long *hwirq, unsigned int *type)
+{
+	if (WARN_ON(fwspec->param_count < 2))
+		return -EINVAL;
+	if (WARN_ON(!fwspec->param[0]))
+		return -EINVAL;
+
+	/* For DT, gsi_base is always zero. */
+	*hwirq = fwspec->param[0] - gsi_base;
+	*type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
+
+	WARN_ON(*type == IRQ_TYPE_NONE);
+
+	return 0;
+}
+
+void aplic_init_hw_global(struct aplic_priv *priv, bool msi_mode)
+{
+	u32 val;
+#ifdef CONFIG_RISCV_M_MODE
+	u32 valH;
+
+	if (msi_mode) {
+		val = priv->msicfg.base_ppn;
+		valH = ((u64)priv->msicfg.base_ppn >> 32) &
+			APLIC_xMSICFGADDRH_BAPPN_MASK;
+		valH |= (priv->msicfg.lhxw & APLIC_xMSICFGADDRH_LHXW_MASK)
+			<< APLIC_xMSICFGADDRH_LHXW_SHIFT;
+		valH |= (priv->msicfg.hhxw & APLIC_xMSICFGADDRH_HHXW_MASK)
+			<< APLIC_xMSICFGADDRH_HHXW_SHIFT;
+		valH |= (priv->msicfg.lhxs & APLIC_xMSICFGADDRH_LHXS_MASK)
+			<< APLIC_xMSICFGADDRH_LHXS_SHIFT;
+		valH |= (priv->msicfg.hhxs & APLIC_xMSICFGADDRH_HHXS_MASK)
+			<< APLIC_xMSICFGADDRH_HHXS_SHIFT;
+		writel(val, priv->regs + APLIC_xMSICFGADDR);
+		writel(valH, priv->regs + APLIC_xMSICFGADDRH);
+	}
+#endif
+
+	/* Setup APLIC domaincfg register */
+	val = readl(priv->regs + APLIC_DOMAINCFG);
+	val |= APLIC_DOMAINCFG_IE;
+	if (msi_mode)
+		val |= APLIC_DOMAINCFG_DM;
+	writel(val, priv->regs + APLIC_DOMAINCFG);
+	if (readl(priv->regs + APLIC_DOMAINCFG) != val)
+		dev_warn(priv->dev, "unable to write 0x%x in domaincfg\n",
+			 val);
+}
+
+static void aplic_init_hw_irqs(struct aplic_priv *priv)
+{
+	int i;
+
+	/* Disable all interrupts */
+	for (i = 0; i <= priv->nr_irqs; i += 32)
+		writel(-1U, priv->regs + APLIC_CLRIE_BASE +
+			    (i / 32) * sizeof(u32));
+
+	/* Set interrupt type and default priority for all interrupts */
+	for (i = 1; i <= priv->nr_irqs; i++) {
+		writel(0, priv->regs + APLIC_SOURCECFG_BASE +
+			  (i - 1) * sizeof(u32));
+		writel(APLIC_DEFAULT_PRIORITY,
+		       priv->regs + APLIC_TARGET_BASE +
+		       (i - 1) * sizeof(u32));
+	}
+
+	/* Clear APLIC domaincfg */
+	writel(0, priv->regs + APLIC_DOMAINCFG);
+}
+
+int aplic_setup_priv(struct aplic_priv *priv, struct device *dev,
+		     void __iomem *regs)
+{
+	struct fwnode_reference_args parent;
+	int rc;
+
+	/* Save device pointer and register base */
+	priv->dev = dev;
+	priv->regs = regs;
+
+	/*
+	 * Find out GSI base number
+	 *
+	 * Note: DT does not define "riscv,gsi-base" property so GSI
+	 * base is always zero for DT.
+	 */
+	rc = fwnode_property_read_u32_array(dev->fwnode, "riscv,gsi-base",
+					    &priv->gsi_base, 1);
+	if (rc)
+		priv->gsi_base = 0;
+
+	/* Find out number of interrupt sources */
+	rc = fwnode_property_read_u32_array(dev->fwnode, "riscv,num-sources",
+					    &priv->nr_irqs, 1);
+	if (rc) {
+		dev_err(dev, "failed to get number of interrupt sources\n");
+		return rc;
+	}
+
+	/* Setup initial state APLIC interrupts */
+	aplic_init_hw_irqs(priv);
+
+	/*
+	 * Find out number of IDCs based on parent interrupts
+	 *
+	 * If "msi-parent" property is present then we ignore the
+	 * APLIC IDCs which forces the APLIC driver to use MSI mode.
+	 */
+	if (!fwnode_property_present(dev->fwnode, "msi-parent")) {
+		while (!fwnode_property_get_reference_args(dev->fwnode,
+				"interrupts-extended", "#interrupt-cells",
+				0, priv->nr_idcs, &parent))
+			priv->nr_idcs++;
+	}
+
+	return 0;
+}
+
+static int aplic_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct resource *res;
+	void __iomem *regs;
+	int rc;
+
+	/* Map the MMIO registers */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "failed to get MMIO resource\n");
+		return -EINVAL;
+	}
+	regs = devm_ioremap(&pdev->dev, res->start, resource_size(res));
+	if (!regs) {
+		dev_err(dev, "failed map MMIO registers\n");
+		return -ENOMEM;
+	}
+
+	/*
+	 * If msi-parent property is present then setup APLIC MSI mode
+	 * otherwise setup APLIC direct mode.
+	 */
+	if (fwnode_property_present(dev->fwnode, "msi-parent"))
+		rc = -ENODEV;
+	else
+		rc = aplic_direct_setup(dev, regs);
+	if (rc) {
+		dev_err(dev, "failed setup APLIC in %s mode\n",
+			fwnode_property_present(dev->fwnode, "msi-parent") ?
+			"MSI" : "direct");
+		return rc;
+	}
+
+	return 0;
+}
+
+static const struct of_device_id aplic_match[] = {
+	{ .compatible = "riscv,aplic" },
+	{}
+};
+
+static struct platform_driver aplic_driver = {
+	.driver = {
+		.name		= "riscv-aplic",
+		.of_match_table	= aplic_match,
+	},
+	.probe = aplic_probe,
+};
+
+static int __init aplic_init(void)
+{
+	/*
+	 * Register APLIC driver as early as possible so that APLIC
+	 * platform device is probed as soon as it is created.
+	 */
+	return platform_driver_register(&aplic_driver);
+}
+core_initcall(aplic_init);
diff --git a/drivers/irqchip/irq-riscv-aplic-main.h b/drivers/irqchip/irq-riscv-aplic-main.h
new file mode 100644
index 000000000000..474a04229334
--- /dev/null
+++ b/drivers/irqchip/irq-riscv-aplic-main.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+
+#ifndef _IRQ_RISCV_APLIC_MAIN_H
+#define _IRQ_RISCV_APLIC_MAIN_H
+
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/fwnode.h>
+
+#define APLIC_DEFAULT_PRIORITY		1
+
+struct aplic_msicfg {
+	phys_addr_t		base_ppn;
+	u32			hhxs;
+	u32			hhxw;
+	u32			lhxs;
+	u32			lhxw;
+};
+
+struct aplic_priv {
+	struct device		*dev;
+	u32			gsi_base;
+	u32			nr_irqs;
+	u32			nr_idcs;
+	void __iomem		*regs;
+	struct aplic_msicfg	msicfg;
+};
+
+void aplic_irq_unmask(struct irq_data *d);
+void aplic_irq_mask(struct irq_data *d);
+int aplic_irq_set_type(struct irq_data *d, unsigned int type);
+int aplic_irqdomain_translate(struct irq_fwspec *fwspec, u32 gsi_base,
+			      unsigned long *hwirq, unsigned int *type);
+void aplic_init_hw_global(struct aplic_priv *priv, bool msi_mode);
+int aplic_setup_priv(struct aplic_priv *priv, struct device *dev,
+		     void __iomem *regs);
+int aplic_direct_setup(struct device *dev, void __iomem *regs);
+
+#endif
diff --git a/include/linux/irqchip/riscv-aplic.h b/include/linux/irqchip/riscv-aplic.h
new file mode 100644
index 000000000000..97e198ea0109
--- /dev/null
+++ b/include/linux/irqchip/riscv-aplic.h
@@ -0,0 +1,119 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+#ifndef __LINUX_IRQCHIP_RISCV_APLIC_H
+#define __LINUX_IRQCHIP_RISCV_APLIC_H
+
+#include <linux/bitops.h>
+
+#define APLIC_MAX_IDC			BIT(14)
+#define APLIC_MAX_SOURCE		1024
+
+#define APLIC_DOMAINCFG			0x0000
+#define APLIC_DOMAINCFG_RDONLY		0x80000000
+#define APLIC_DOMAINCFG_IE		BIT(8)
+#define APLIC_DOMAINCFG_DM		BIT(2)
+#define APLIC_DOMAINCFG_BE		BIT(0)
+
+#define APLIC_SOURCECFG_BASE		0x0004
+#define APLIC_SOURCECFG_D		BIT(10)
+#define APLIC_SOURCECFG_CHILDIDX_MASK	0x000003ff
+#define APLIC_SOURCECFG_SM_MASK	0x00000007
+#define APLIC_SOURCECFG_SM_INACTIVE	0x0
+#define APLIC_SOURCECFG_SM_DETACH	0x1
+#define APLIC_SOURCECFG_SM_EDGE_RISE	0x4
+#define APLIC_SOURCECFG_SM_EDGE_FALL	0x5
+#define APLIC_SOURCECFG_SM_LEVEL_HIGH	0x6
+#define APLIC_SOURCECFG_SM_LEVEL_LOW	0x7
+
+#define APLIC_MMSICFGADDR		0x1bc0
+#define APLIC_MMSICFGADDRH		0x1bc4
+#define APLIC_SMSICFGADDR		0x1bc8
+#define APLIC_SMSICFGADDRH		0x1bcc
+
+#ifdef CONFIG_RISCV_M_MODE
+#define APLIC_xMSICFGADDR		APLIC_MMSICFGADDR
+#define APLIC_xMSICFGADDRH		APLIC_MMSICFGADDRH
+#else
+#define APLIC_xMSICFGADDR		APLIC_SMSICFGADDR
+#define APLIC_xMSICFGADDRH		APLIC_SMSICFGADDRH
+#endif
+
+#define APLIC_xMSICFGADDRH_L		BIT(31)
+#define APLIC_xMSICFGADDRH_HHXS_MASK	0x1f
+#define APLIC_xMSICFGADDRH_HHXS_SHIFT	24
+#define APLIC_xMSICFGADDRH_LHXS_MASK	0x7
+#define APLIC_xMSICFGADDRH_LHXS_SHIFT	20
+#define APLIC_xMSICFGADDRH_HHXW_MASK	0x7
+#define APLIC_xMSICFGADDRH_HHXW_SHIFT	16
+#define APLIC_xMSICFGADDRH_LHXW_MASK	0xf
+#define APLIC_xMSICFGADDRH_LHXW_SHIFT	12
+#define APLIC_xMSICFGADDRH_BAPPN_MASK	0xfff
+
+#define APLIC_xMSICFGADDR_PPN_SHIFT	12
+
+#define APLIC_xMSICFGADDR_PPN_HART(__lhxs) \
+	(BIT(__lhxs) - 1)
+
+#define APLIC_xMSICFGADDR_PPN_LHX_MASK(__lhxw) \
+	(BIT(__lhxw) - 1)
+#define APLIC_xMSICFGADDR_PPN_LHX_SHIFT(__lhxs) \
+	((__lhxs))
+#define APLIC_xMSICFGADDR_PPN_LHX(__lhxw, __lhxs) \
+	(APLIC_xMSICFGADDR_PPN_LHX_MASK(__lhxw) << \
+	 APLIC_xMSICFGADDR_PPN_LHX_SHIFT(__lhxs))
+
+#define APLIC_xMSICFGADDR_PPN_HHX_MASK(__hhxw) \
+	(BIT(__hhxw) - 1)
+#define APLIC_xMSICFGADDR_PPN_HHX_SHIFT(__hhxs) \
+	((__hhxs) + APLIC_xMSICFGADDR_PPN_SHIFT)
+#define APLIC_xMSICFGADDR_PPN_HHX(__hhxw, __hhxs) \
+	(APLIC_xMSICFGADDR_PPN_HHX_MASK(__hhxw) << \
+	 APLIC_xMSICFGADDR_PPN_HHX_SHIFT(__hhxs))
+
+#define APLIC_IRQBITS_PER_REG		32
+
+#define APLIC_SETIP_BASE		0x1c00
+#define APLIC_SETIPNUM			0x1cdc
+
+#define APLIC_CLRIP_BASE		0x1d00
+#define APLIC_CLRIPNUM			0x1ddc
+
+#define APLIC_SETIE_BASE		0x1e00
+#define APLIC_SETIENUM			0x1edc
+
+#define APLIC_CLRIE_BASE		0x1f00
+#define APLIC_CLRIENUM			0x1fdc
+
+#define APLIC_SETIPNUM_LE		0x2000
+#define APLIC_SETIPNUM_BE		0x2004
+
+#define APLIC_GENMSI			0x3000
+
+#define APLIC_TARGET_BASE		0x3004
+#define APLIC_TARGET_HART_IDX_SHIFT	18
+#define APLIC_TARGET_HART_IDX_MASK	0x3fff
+#define APLIC_TARGET_GUEST_IDX_SHIFT	12
+#define APLIC_TARGET_GUEST_IDX_MASK	0x3f
+#define APLIC_TARGET_IPRIO_MASK	0xff
+#define APLIC_TARGET_EIID_MASK	0x7ff
+
+#define APLIC_IDC_BASE			0x4000
+#define APLIC_IDC_SIZE			32
+
+#define APLIC_IDC_IDELIVERY		0x00
+
+#define APLIC_IDC_IFORCE		0x04
+
+#define APLIC_IDC_ITHRESHOLD		0x08
+
+#define APLIC_IDC_TOPI			0x18
+#define APLIC_IDC_TOPI_ID_SHIFT	16
+#define APLIC_IDC_TOPI_ID_MASK	0x3ff
+#define APLIC_IDC_TOPI_PRIO_MASK	0xff
+
+#define APLIC_IDC_CLAIMI		0x1c
+
+#endif
-- 
2.34.1

[PATCH v8 13/16] irqchip: Add RISC-V advanced PLIC driver for direct-mode

[Anup Patel]

The RISC-V advanced interrupt architecture (AIA) specification defines
advanced platform-level interrupt controller (APLIC) which has two modes
of operation: 1) Direct mode and 2) MSI mode.
(For more details, refer https://github.com/riscv/riscv-aia)

In APLIC direct-mode, wired interrupts are forwared to CPUs (or HARTs)
as a local external interrupt.

We add a platform irqchip driver for the RISC-V APLIC direct-mode to
support RISC-V platforms having only wired interrupts.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 drivers/irqchip/Kconfig                  |   5 +
 drivers/irqchip/Makefile                 |   1 +
 drivers/irqchip/irq-riscv-aplic-direct.c | 326 +++++++++++++++++++++++
 drivers/irqchip/irq-riscv-aplic-main.c   | 240 +++++++++++++++++
 drivers/irqchip/irq-riscv-aplic-main.h   |  45 ++++
 include/linux/irqchip/riscv-aplic.h      | 119 +++++++++
 6 files changed, 736 insertions(+)
 create mode 100644 drivers/irqchip/irq-riscv-aplic-direct.c
 create mode 100644 drivers/irqchip/irq-riscv-aplic-main.c
 create mode 100644 drivers/irqchip/irq-riscv-aplic-main.h
 create mode 100644 include/linux/irqchip/riscv-aplic.h

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index a6aad78076a0..44c455084d09 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -545,6 +545,11 @@ config SIFIVE_PLIC
 	select IRQ_DOMAIN_HIERARCHY
 	select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
 
+config RISCV_APLIC
+	bool
+	depends on RISCV
+	select IRQ_DOMAIN_HIERARCHY
+
 config RISCV_IMSIC
 	bool
 	depends on RISCV
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index abca445a3229..7f8289790ed8 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -95,6 +95,7 @@ obj-$(CONFIG_QCOM_MPM)			+= irq-qcom-mpm.o
 obj-$(CONFIG_CSKY_MPINTC)		+= irq-csky-mpintc.o
 obj-$(CONFIG_CSKY_APB_INTC)		+= irq-csky-apb-intc.o
 obj-$(CONFIG_RISCV_INTC)		+= irq-riscv-intc.o
+obj-$(CONFIG_RISCV_APLIC)		+= irq-riscv-aplic-main.o irq-riscv-aplic-direct.o
 obj-$(CONFIG_RISCV_IMSIC)		+= irq-riscv-imsic-state.o irq-riscv-imsic-early.o irq-riscv-imsic-platform.o
 obj-$(CONFIG_SIFIVE_PLIC)		+= irq-sifive-plic.o
 obj-$(CONFIG_IMX_IRQSTEER)		+= irq-imx-irqsteer.o
diff --git a/drivers/irqchip/irq-riscv-aplic-direct.c b/drivers/irqchip/irq-riscv-aplic-direct.c
new file mode 100644
index 000000000000..e36d655a1490
--- /dev/null
+++ b/drivers/irqchip/irq-riscv-aplic-direct.c
@@ -0,0 +1,326 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+
+#include <linux/bitops.h>
+#include <linux/cpu.h>
+#include <linux/interrupt.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqchip/riscv-aplic.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/printk.h>
+#include <linux/smp.h>
+
+#include "irq-riscv-aplic-main.h"
+
+#define APLIC_DISABLE_IDELIVERY		0
+#define APLIC_ENABLE_IDELIVERY		1
+#define APLIC_DISABLE_ITHRESHOLD	1
+#define APLIC_ENABLE_ITHRESHOLD		0
+
+struct aplic_direct {
+	struct aplic_priv	priv;
+	struct irq_domain	*irqdomain;
+	struct cpumask		lmask;
+};
+
+struct aplic_idc {
+	unsigned int		hart_index;
+	void __iomem		*regs;
+	struct aplic_direct	*direct;
+};
+
+static unsigned int aplic_direct_parent_irq;
+static DEFINE_PER_CPU(struct aplic_idc, aplic_idcs);
+
+static void aplic_direct_irq_eoi(struct irq_data *d)
+{
+	/*
+	 * The fasteoi_handler requires irq_eoi() callback hence
+	 * provide a dummy handler.
+	 */
+}
+
+#ifdef CONFIG_SMP
+static int aplic_direct_set_affinity(struct irq_data *d,
+				  const struct cpumask *mask_val, bool force)
+{
+	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
+	struct aplic_direct *direct =
+			container_of(priv, struct aplic_direct, priv);
+	struct aplic_idc *idc;
+	unsigned int cpu, val;
+	struct cpumask amask;
+	void __iomem *target;
+
+	cpumask_and(&amask, &direct->lmask, mask_val);
+
+	if (force)
+		cpu = cpumask_first(&amask);
+	else
+		cpu = cpumask_any_and(&amask, cpu_online_mask);
+
+	if (cpu >= nr_cpu_ids)
+		return -EINVAL;
+
+	idc = per_cpu_ptr(&aplic_idcs, cpu);
+	target = priv->regs + APLIC_TARGET_BASE;
+	target += (d->hwirq - 1) * sizeof(u32);
+	val = idc->hart_index & APLIC_TARGET_HART_IDX_MASK;
+	val <<= APLIC_TARGET_HART_IDX_SHIFT;
+	val |= APLIC_DEFAULT_PRIORITY;
+	writel(val, target);
+
+	irq_data_update_effective_affinity(d, cpumask_of(cpu));
+
+	return IRQ_SET_MASK_OK_DONE;
+}
+#endif
+
+static struct irq_chip aplic_direct_chip = {
+	.name		= "APLIC-DIRECT",
+	.irq_mask	= aplic_irq_mask,
+	.irq_unmask	= aplic_irq_unmask,
+	.irq_set_type	= aplic_irq_set_type,
+	.irq_eoi	= aplic_direct_irq_eoi,
+#ifdef CONFIG_SMP
+	.irq_set_affinity = aplic_direct_set_affinity,
+#endif
+	.flags		= IRQCHIP_SET_TYPE_MASKED |
+			  IRQCHIP_SKIP_SET_WAKE |
+			  IRQCHIP_MASK_ON_SUSPEND,
+};
+
+static int aplic_direct_irqdomain_translate(struct irq_domain *d,
+					 struct irq_fwspec *fwspec,
+					 unsigned long *hwirq,
+					 unsigned int *type)
+{
+	struct aplic_priv *priv = d->host_data;
+
+	return aplic_irqdomain_translate(fwspec, priv->gsi_base,
+					 hwirq, type);
+}
+
+static int aplic_direct_irqdomain_alloc(struct irq_domain *domain,
+				     unsigned int virq, unsigned int nr_irqs,
+				     void *arg)
+{
+	int i, ret;
+	unsigned int type;
+	irq_hw_number_t hwirq;
+	struct irq_fwspec *fwspec = arg;
+	struct aplic_priv *priv = domain->host_data;
+	struct aplic_direct *direct =
+			container_of(priv, struct aplic_direct, priv);
+
+	ret = aplic_irqdomain_translate(fwspec, priv->gsi_base,
+					&hwirq, &type);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < nr_irqs; i++) {
+		irq_domain_set_info(domain, virq + i, hwirq + i,
+				    &aplic_direct_chip, priv,
+				    handle_fasteoi_irq, NULL, NULL);
+		irq_set_affinity(virq + i, &direct->lmask);
+		/* See the reason described in aplic_msi_irqdomain_alloc() */
+		irq_set_status_flags(virq + i, IRQ_DISABLE_UNLAZY);
+	}
+
+	return 0;
+}
+
+static const struct irq_domain_ops aplic_direct_irqdomain_ops = {
+	.translate	= aplic_direct_irqdomain_translate,
+	.alloc		= aplic_direct_irqdomain_alloc,
+	.free		= irq_domain_free_irqs_top,
+};
+
+/*
+ * To handle an APLIC direct interrupts, we just read the CLAIMI register
+ * which will return highest priority pending interrupt and clear the
+ * pending bit of the interrupt. This process is repeated until CLAIMI
+ * register return zero value.
+ */
+static void aplic_direct_handle_irq(struct irq_desc *desc)
+{
+	struct aplic_idc *idc = this_cpu_ptr(&aplic_idcs);
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	struct irq_domain *irqdomain = idc->direct->irqdomain;
+	irq_hw_number_t hw_irq;
+	int irq;
+
+	chained_irq_enter(chip, desc);
+
+	while ((hw_irq = readl(idc->regs + APLIC_IDC_CLAIMI))) {
+		hw_irq = hw_irq >> APLIC_IDC_TOPI_ID_SHIFT;
+		irq = irq_find_mapping(irqdomain, hw_irq);
+
+		if (unlikely(irq <= 0))
+			dev_warn_ratelimited(idc->direct->priv.dev,
+					     "hw_irq %lu mapping not found\n",
+					     hw_irq);
+		else
+			generic_handle_irq(irq);
+	}
+
+	chained_irq_exit(chip, desc);
+}
+
+static void aplic_idc_set_delivery(struct aplic_idc *idc, bool en)
+{
+	u32 de = (en) ? APLIC_ENABLE_IDELIVERY : APLIC_DISABLE_IDELIVERY;
+	u32 th = (en) ? APLIC_ENABLE_ITHRESHOLD : APLIC_DISABLE_ITHRESHOLD;
+
+	/* Priority must be less than threshold for interrupt triggering */
+	writel(th, idc->regs + APLIC_IDC_ITHRESHOLD);
+
+	/* Delivery must be set to 1 for interrupt triggering */
+	writel(de, idc->regs + APLIC_IDC_IDELIVERY);
+}
+
+static int aplic_direct_dying_cpu(unsigned int cpu)
+{
+	if (aplic_direct_parent_irq)
+		disable_percpu_irq(aplic_direct_parent_irq);
+
+	return 0;
+}
+
+static int aplic_direct_starting_cpu(unsigned int cpu)
+{
+	if (aplic_direct_parent_irq)
+		enable_percpu_irq(aplic_direct_parent_irq,
+				irq_get_trigger_type(aplic_direct_parent_irq));
+
+	return 0;
+}
+
+int aplic_direct_setup(struct device *dev, void __iomem *regs)
+{
+	int i, j, rc, cpu, setup_count = 0;
+	struct fwnode_reference_args parent;
+	struct aplic_direct *direct;
+	struct aplic_priv *priv;
+	struct irq_domain *domain;
+	unsigned long hartid;
+	struct aplic_idc *idc;
+	u32 val;
+
+	direct = kzalloc(sizeof(*direct), GFP_KERNEL);
+	if (!direct)
+		return -ENOMEM;
+	priv = &direct->priv;
+
+	rc = aplic_setup_priv(priv, dev, regs);
+	if (rc) {
+		dev_err(dev, "failed to create APLIC context\n");
+		kfree(direct);
+		return rc;
+	}
+
+	/* Setup per-CPU IDC and target CPU mask */
+	for (i = 0; i < priv->nr_idcs; i++) {
+		rc = fwnode_property_get_reference_args(dev->fwnode,
+				"interrupts-extended", "#interrupt-cells",
+				0, i, &parent);
+		if (rc) {
+			dev_warn(dev, "parent irq for IDC%d not found\n", i);
+			continue;
+		}
+
+		/*
+		 * Skip interrupts other than external interrupts for
+		 * current privilege level.
+		 */
+		if (parent.args[0] != RV_IRQ_EXT)
+			continue;
+
+		rc = riscv_get_intc_hartid(parent.fwnode, &hartid);
+		if (rc) {
+			dev_warn(dev, "invalid hartid for IDC%d\n", i);
+			continue;
+		}
+
+		cpu = riscv_hartid_to_cpuid(hartid);
+		if (cpu < 0) {
+			dev_warn(dev, "invalid cpuid for IDC%d\n", i);
+			continue;
+		}
+
+		cpumask_set_cpu(cpu, &direct->lmask);
+
+		idc = per_cpu_ptr(&aplic_idcs, cpu);
+		idc->hart_index = i;
+		idc->regs = priv->regs + APLIC_IDC_BASE + i * APLIC_IDC_SIZE;
+		idc->direct = direct;
+
+		aplic_idc_set_delivery(idc, true);
+
+		/*
+		 * Boot cpu might not have APLIC hart_index = 0 so check
+		 * and update target registers of all interrupts.
+		 */
+		if (cpu == smp_processor_id() && idc->hart_index) {
+			val = idc->hart_index & APLIC_TARGET_HART_IDX_MASK;
+			val <<= APLIC_TARGET_HART_IDX_SHIFT;
+			val |= APLIC_DEFAULT_PRIORITY;
+			for (j = 1; j <= priv->nr_irqs; j++)
+				writel(val, priv->regs + APLIC_TARGET_BASE +
+					    (j - 1) * sizeof(u32));
+		}
+
+		setup_count++;
+	}
+
+	/* Find parent domain and register chained handler */
+	domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
+					  DOMAIN_BUS_ANY);
+	if (!aplic_direct_parent_irq && domain) {
+		aplic_direct_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT);
+		if (aplic_direct_parent_irq) {
+			irq_set_chained_handler(aplic_direct_parent_irq,
+						aplic_direct_handle_irq);
+
+			/*
+			 * Setup CPUHP notifier to enable parent
+			 * interrupt on all CPUs
+			 */
+			cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
+					  "irqchip/riscv/aplic:starting",
+					  aplic_direct_starting_cpu,
+					  aplic_direct_dying_cpu);
+		}
+	}
+
+	/* Fail if we were not able to setup IDC for any CPU */
+	if (!setup_count) {
+		kfree(direct);
+		return -ENODEV;
+	}
+
+	/* Setup global config and interrupt delivery */
+	aplic_init_hw_global(priv, false);
+
+	/* Create irq domain instance for the APLIC */
+	direct->irqdomain = irq_domain_create_linear(dev->fwnode,
+						   priv->nr_irqs + 1,
+						   &aplic_direct_irqdomain_ops,
+						   priv);
+	if (!direct->irqdomain) {
+		dev_err(dev, "failed to create direct irq domain\n");
+		kfree(direct);
+		return -ENOMEM;
+	}
+
+	/* Advertise the interrupt controller */
+	dev_info(dev, "%d interrupts directly connected to %d CPUs\n",
+		 priv->nr_irqs, priv->nr_idcs);
+
+	return 0;
+}
diff --git a/drivers/irqchip/irq-riscv-aplic-main.c b/drivers/irqchip/irq-riscv-aplic-main.c
new file mode 100644
index 000000000000..d62a096774c4
--- /dev/null
+++ b/drivers/irqchip/irq-riscv-aplic-main.c
@@ -0,0 +1,240 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+
+#include <linux/printk.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/irqchip/riscv-aplic.h>
+
+#include "irq-riscv-aplic-main.h"
+
+void aplic_irq_unmask(struct irq_data *d)
+{
+	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
+
+	writel(d->hwirq, priv->regs + APLIC_SETIENUM);
+}
+
+void aplic_irq_mask(struct irq_data *d)
+{
+	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
+
+	writel(d->hwirq, priv->regs + APLIC_CLRIENUM);
+}
+
+int aplic_irq_set_type(struct irq_data *d, unsigned int type)
+{
+	u32 val = 0;
+	void __iomem *sourcecfg;
+	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
+
+	switch (type) {
+	case IRQ_TYPE_NONE:
+		val = APLIC_SOURCECFG_SM_INACTIVE;
+		break;
+	case IRQ_TYPE_LEVEL_LOW:
+		val = APLIC_SOURCECFG_SM_LEVEL_LOW;
+		break;
+	case IRQ_TYPE_LEVEL_HIGH:
+		val = APLIC_SOURCECFG_SM_LEVEL_HIGH;
+		break;
+	case IRQ_TYPE_EDGE_FALLING:
+		val = APLIC_SOURCECFG_SM_EDGE_FALL;
+		break;
+	case IRQ_TYPE_EDGE_RISING:
+		val = APLIC_SOURCECFG_SM_EDGE_RISE;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	sourcecfg = priv->regs + APLIC_SOURCECFG_BASE;
+	sourcecfg += (d->hwirq - 1) * sizeof(u32);
+	writel(val, sourcecfg);
+
+	return 0;
+}
+
+int aplic_irqdomain_translate(struct irq_fwspec *fwspec, u32 gsi_base,
+			      unsigned long *hwirq, unsigned int *type)
+{
+	if (WARN_ON(fwspec->param_count < 2))
+		return -EINVAL;
+	if (WARN_ON(!fwspec->param[0]))
+		return -EINVAL;
+
+	/* For DT, gsi_base is always zero. */
+	*hwirq = fwspec->param[0] - gsi_base;
+	*type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
+
+	WARN_ON(*type == IRQ_TYPE_NONE);
+
+	return 0;
+}
+
+void aplic_init_hw_global(struct aplic_priv *priv, bool msi_mode)
+{
+	u32 val;
+#ifdef CONFIG_RISCV_M_MODE
+	u32 valH;
+
+	if (msi_mode) {
+		val = priv->msicfg.base_ppn;
+		valH = ((u64)priv->msicfg.base_ppn >> 32) &
+			APLIC_xMSICFGADDRH_BAPPN_MASK;
+		valH |= (priv->msicfg.lhxw & APLIC_xMSICFGADDRH_LHXW_MASK)
+			<< APLIC_xMSICFGADDRH_LHXW_SHIFT;
+		valH |= (priv->msicfg.hhxw & APLIC_xMSICFGADDRH_HHXW_MASK)
+			<< APLIC_xMSICFGADDRH_HHXW_SHIFT;
+		valH |= (priv->msicfg.lhxs & APLIC_xMSICFGADDRH_LHXS_MASK)
+			<< APLIC_xMSICFGADDRH_LHXS_SHIFT;
+		valH |= (priv->msicfg.hhxs & APLIC_xMSICFGADDRH_HHXS_MASK)
+			<< APLIC_xMSICFGADDRH_HHXS_SHIFT;
+		writel(val, priv->regs + APLIC_xMSICFGADDR);
+		writel(valH, priv->regs + APLIC_xMSICFGADDRH);
+	}
+#endif
+
+	/* Setup APLIC domaincfg register */
+	val = readl(priv->regs + APLIC_DOMAINCFG);
+	val |= APLIC_DOMAINCFG_IE;
+	if (msi_mode)
+		val |= APLIC_DOMAINCFG_DM;
+	writel(val, priv->regs + APLIC_DOMAINCFG);
+	if (readl(priv->regs + APLIC_DOMAINCFG) != val)
+		dev_warn(priv->dev, "unable to write 0x%x in domaincfg\n",
+			 val);
+}
+
+static void aplic_init_hw_irqs(struct aplic_priv *priv)
+{
+	int i;
+
+	/* Disable all interrupts */
+	for (i = 0; i <= priv->nr_irqs; i += 32)
+		writel(-1U, priv->regs + APLIC_CLRIE_BASE +
+			    (i / 32) * sizeof(u32));
+
+	/* Set interrupt type and default priority for all interrupts */
+	for (i = 1; i <= priv->nr_irqs; i++) {
+		writel(0, priv->regs + APLIC_SOURCECFG_BASE +
+			  (i - 1) * sizeof(u32));
+		writel(APLIC_DEFAULT_PRIORITY,
+		       priv->regs + APLIC_TARGET_BASE +
+		       (i - 1) * sizeof(u32));
+	}
+
+	/* Clear APLIC domaincfg */
+	writel(0, priv->regs + APLIC_DOMAINCFG);
+}
+
+int aplic_setup_priv(struct aplic_priv *priv, struct device *dev,
+		     void __iomem *regs)
+{
+	struct fwnode_reference_args parent;
+	int rc;
+
+	/* Save device pointer and register base */
+	priv->dev = dev;
+	priv->regs = regs;
+
+	/*
+	 * Find out GSI base number
+	 *
+	 * Note: DT does not define "riscv,gsi-base" property so GSI
+	 * base is always zero for DT.
+	 */
+	rc = fwnode_property_read_u32_array(dev->fwnode, "riscv,gsi-base",
+					    &priv->gsi_base, 1);
+	if (rc)
+		priv->gsi_base = 0;
+
+	/* Find out number of interrupt sources */
+	rc = fwnode_property_read_u32_array(dev->fwnode, "riscv,num-sources",
+					    &priv->nr_irqs, 1);
+	if (rc) {
+		dev_err(dev, "failed to get number of interrupt sources\n");
+		return rc;
+	}
+
+	/* Setup initial state APLIC interrupts */
+	aplic_init_hw_irqs(priv);
+
+	/*
+	 * Find out number of IDCs based on parent interrupts
+	 *
+	 * If "msi-parent" property is present then we ignore the
+	 * APLIC IDCs which forces the APLIC driver to use MSI mode.
+	 */
+	if (!fwnode_property_present(dev->fwnode, "msi-parent")) {
+		while (!fwnode_property_get_reference_args(dev->fwnode,
+				"interrupts-extended", "#interrupt-cells",
+				0, priv->nr_idcs, &parent))
+			priv->nr_idcs++;
+	}
+
+	return 0;
+}
+
+static int aplic_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct resource *res;
+	void __iomem *regs;
+	int rc;
+
+	/* Map the MMIO registers */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "failed to get MMIO resource\n");
+		return -EINVAL;
+	}
+	regs = devm_ioremap(&pdev->dev, res->start, resource_size(res));
+	if (!regs) {
+		dev_err(dev, "failed map MMIO registers\n");
+		return -ENOMEM;
+	}
+
+	/*
+	 * If msi-parent property is present then setup APLIC MSI mode
+	 * otherwise setup APLIC direct mode.
+	 */
+	if (fwnode_property_present(dev->fwnode, "msi-parent"))
+		rc = -ENODEV;
+	else
+		rc = aplic_direct_setup(dev, regs);
+	if (rc) {
+		dev_err(dev, "failed setup APLIC in %s mode\n",
+			fwnode_property_present(dev->fwnode, "msi-parent") ?
+			"MSI" : "direct");
+		return rc;
+	}
+
+	return 0;
+}
+
+static const struct of_device_id aplic_match[] = {
+	{ .compatible = "riscv,aplic" },
+	{}
+};
+
+static struct platform_driver aplic_driver = {
+	.driver = {
+		.name		= "riscv-aplic",
+		.of_match_table	= aplic_match,
+	},
+	.probe = aplic_probe,
+};
+
+static int __init aplic_init(void)
+{
+	/*
+	 * Register APLIC driver as early as possible so that APLIC
+	 * platform device is probed as soon as it is created.
+	 */
+	return platform_driver_register(&aplic_driver);
+}
+core_initcall(aplic_init);
diff --git a/drivers/irqchip/irq-riscv-aplic-main.h b/drivers/irqchip/irq-riscv-aplic-main.h
new file mode 100644
index 000000000000..474a04229334
--- /dev/null
+++ b/drivers/irqchip/irq-riscv-aplic-main.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+
+#ifndef _IRQ_RISCV_APLIC_MAIN_H
+#define _IRQ_RISCV_APLIC_MAIN_H
+
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/fwnode.h>
+
+#define APLIC_DEFAULT_PRIORITY		1
+
+struct aplic_msicfg {
+	phys_addr_t		base_ppn;
+	u32			hhxs;
+	u32			hhxw;
+	u32			lhxs;
+	u32			lhxw;
+};
+
+struct aplic_priv {
+	struct device		*dev;
+	u32			gsi_base;
+	u32			nr_irqs;
+	u32			nr_idcs;
+	void __iomem		*regs;
+	struct aplic_msicfg	msicfg;
+};
+
+void aplic_irq_unmask(struct irq_data *d);
+void aplic_irq_mask(struct irq_data *d);
+int aplic_irq_set_type(struct irq_data *d, unsigned int type);
+int aplic_irqdomain_translate(struct irq_fwspec *fwspec, u32 gsi_base,
+			      unsigned long *hwirq, unsigned int *type);
+void aplic_init_hw_global(struct aplic_priv *priv, bool msi_mode);
+int aplic_setup_priv(struct aplic_priv *priv, struct device *dev,
+		     void __iomem *regs);
+int aplic_direct_setup(struct device *dev, void __iomem *regs);
+
+#endif
diff --git a/include/linux/irqchip/riscv-aplic.h b/include/linux/irqchip/riscv-aplic.h
new file mode 100644
index 000000000000..97e198ea0109
--- /dev/null
+++ b/include/linux/irqchip/riscv-aplic.h
@@ -0,0 +1,119 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+#ifndef __LINUX_IRQCHIP_RISCV_APLIC_H
+#define __LINUX_IRQCHIP_RISCV_APLIC_H
+
+#include <linux/bitops.h>
+
+#define APLIC_MAX_IDC			BIT(14)
+#define APLIC_MAX_SOURCE		1024
+
+#define APLIC_DOMAINCFG			0x0000
+#define APLIC_DOMAINCFG_RDONLY		0x80000000
+#define APLIC_DOMAINCFG_IE		BIT(8)
+#define APLIC_DOMAINCFG_DM		BIT(2)
+#define APLIC_DOMAINCFG_BE		BIT(0)
+
+#define APLIC_SOURCECFG_BASE		0x0004
+#define APLIC_SOURCECFG_D		BIT(10)
+#define APLIC_SOURCECFG_CHILDIDX_MASK	0x000003ff
+#define APLIC_SOURCECFG_SM_MASK	0x00000007
+#define APLIC_SOURCECFG_SM_INACTIVE	0x0
+#define APLIC_SOURCECFG_SM_DETACH	0x1
+#define APLIC_SOURCECFG_SM_EDGE_RISE	0x4
+#define APLIC_SOURCECFG_SM_EDGE_FALL	0x5
+#define APLIC_SOURCECFG_SM_LEVEL_HIGH	0x6
+#define APLIC_SOURCECFG_SM_LEVEL_LOW	0x7
+
+#define APLIC_MMSICFGADDR		0x1bc0
+#define APLIC_MMSICFGADDRH		0x1bc4
+#define APLIC_SMSICFGADDR		0x1bc8
+#define APLIC_SMSICFGADDRH		0x1bcc
+
+#ifdef CONFIG_RISCV_M_MODE
+#define APLIC_xMSICFGADDR		APLIC_MMSICFGADDR
+#define APLIC_xMSICFGADDRH		APLIC_MMSICFGADDRH
+#else
+#define APLIC_xMSICFGADDR		APLIC_SMSICFGADDR
+#define APLIC_xMSICFGADDRH		APLIC_SMSICFGADDRH
+#endif
+
+#define APLIC_xMSICFGADDRH_L		BIT(31)
+#define APLIC_xMSICFGADDRH_HHXS_MASK	0x1f
+#define APLIC_xMSICFGADDRH_HHXS_SHIFT	24
+#define APLIC_xMSICFGADDRH_LHXS_MASK	0x7
+#define APLIC_xMSICFGADDRH_LHXS_SHIFT	20
+#define APLIC_xMSICFGADDRH_HHXW_MASK	0x7
+#define APLIC_xMSICFGADDRH_HHXW_SHIFT	16
+#define APLIC_xMSICFGADDRH_LHXW_MASK	0xf
+#define APLIC_xMSICFGADDRH_LHXW_SHIFT	12
+#define APLIC_xMSICFGADDRH_BAPPN_MASK	0xfff
+
+#define APLIC_xMSICFGADDR_PPN_SHIFT	12
+
+#define APLIC_xMSICFGADDR_PPN_HART(__lhxs) \
+	(BIT(__lhxs) - 1)
+
+#define APLIC_xMSICFGADDR_PPN_LHX_MASK(__lhxw) \
+	(BIT(__lhxw) - 1)
+#define APLIC_xMSICFGADDR_PPN_LHX_SHIFT(__lhxs) \
+	((__lhxs))
+#define APLIC_xMSICFGADDR_PPN_LHX(__lhxw, __lhxs) \
+	(APLIC_xMSICFGADDR_PPN_LHX_MASK(__lhxw) << \
+	 APLIC_xMSICFGADDR_PPN_LHX_SHIFT(__lhxs))
+
+#define APLIC_xMSICFGADDR_PPN_HHX_MASK(__hhxw) \
+	(BIT(__hhxw) - 1)
+#define APLIC_xMSICFGADDR_PPN_HHX_SHIFT(__hhxs) \
+	((__hhxs) + APLIC_xMSICFGADDR_PPN_SHIFT)
+#define APLIC_xMSICFGADDR_PPN_HHX(__hhxw, __hhxs) \
+	(APLIC_xMSICFGADDR_PPN_HHX_MASK(__hhxw) << \
+	 APLIC_xMSICFGADDR_PPN_HHX_SHIFT(__hhxs))
+
+#define APLIC_IRQBITS_PER_REG		32
+
+#define APLIC_SETIP_BASE		0x1c00
+#define APLIC_SETIPNUM			0x1cdc
+
+#define APLIC_CLRIP_BASE		0x1d00
+#define APLIC_CLRIPNUM			0x1ddc
+
+#define APLIC_SETIE_BASE		0x1e00
+#define APLIC_SETIENUM			0x1edc
+
+#define APLIC_CLRIE_BASE		0x1f00
+#define APLIC_CLRIENUM			0x1fdc
+
+#define APLIC_SETIPNUM_LE		0x2000
+#define APLIC_SETIPNUM_BE		0x2004
+
+#define APLIC_GENMSI			0x3000
+
+#define APLIC_TARGET_BASE		0x3004
+#define APLIC_TARGET_HART_IDX_SHIFT	18
+#define APLIC_TARGET_HART_IDX_MASK	0x3fff
+#define APLIC_TARGET_GUEST_IDX_SHIFT	12
+#define APLIC_TARGET_GUEST_IDX_MASK	0x3f
+#define APLIC_TARGET_IPRIO_MASK	0xff
+#define APLIC_TARGET_EIID_MASK	0x7ff
+
+#define APLIC_IDC_BASE			0x4000
+#define APLIC_IDC_SIZE			32
+
+#define APLIC_IDC_IDELIVERY		0x00
+
+#define APLIC_IDC_IFORCE		0x04
+
+#define APLIC_IDC_ITHRESHOLD		0x08
+
+#define APLIC_IDC_TOPI			0x18
+#define APLIC_IDC_TOPI_ID_SHIFT	16
+#define APLIC_IDC_TOPI_ID_MASK	0x3ff
+#define APLIC_IDC_TOPI_PRIO_MASK	0xff
+
+#define APLIC_IDC_CLAIMI		0x1c
+
+#endif
-- 
2.34.1


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[PATCH v8 14/16] irqchip/riscv-aplic: Add support for MSI-mode

[Anup Patel]

The RISC-V advanced platform-level interrupt controller (APLIC) has
two modes of operation: 1) Direct mode and 2) MSI mode.
(For more details, refer https://github.com/riscv/riscv-aia)

In APLIC MSI-mode, wired interrupts are forwared as message signaled
interrupts (MSIs) to CPUs via IMSIC.

We extend the existing APLIC irqchip driver to support MSI-mode for
RISC-V platforms having both wired interrupts and MSIs.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 drivers/irqchip/Kconfig                |   6 +
 drivers/irqchip/Makefile               |   1 +
 drivers/irqchip/irq-riscv-aplic-main.c |   2 +-
 drivers/irqchip/irq-riscv-aplic-main.h |   8 +
 drivers/irqchip/irq-riscv-aplic-msi.c  | 285 +++++++++++++++++++++++++
 5 files changed, 301 insertions(+), 1 deletion(-)
 create mode 100644 drivers/irqchip/irq-riscv-aplic-msi.c

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 44c455084d09..31c069bf7343 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -550,6 +550,12 @@ config RISCV_APLIC
 	depends on RISCV
 	select IRQ_DOMAIN_HIERARCHY
 
+config RISCV_APLIC_MSI
+	bool
+	depends on RISCV_APLIC
+	select GENERIC_MSI_IRQ
+	default RISCV_APLIC
+
 config RISCV_IMSIC
 	bool
 	depends on RISCV
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 7f8289790ed8..47995fdb2c60 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -96,6 +96,7 @@ obj-$(CONFIG_CSKY_MPINTC)		+= irq-csky-mpintc.o
 obj-$(CONFIG_CSKY_APB_INTC)		+= irq-csky-apb-intc.o
 obj-$(CONFIG_RISCV_INTC)		+= irq-riscv-intc.o
 obj-$(CONFIG_RISCV_APLIC)		+= irq-riscv-aplic-main.o irq-riscv-aplic-direct.o
+obj-$(CONFIG_RISCV_APLIC_MSI)		+= irq-riscv-aplic-msi.o
 obj-$(CONFIG_RISCV_IMSIC)		+= irq-riscv-imsic-state.o irq-riscv-imsic-early.o irq-riscv-imsic-platform.o
 obj-$(CONFIG_SIFIVE_PLIC)		+= irq-sifive-plic.o
 obj-$(CONFIG_IMX_IRQSTEER)		+= irq-imx-irqsteer.o
diff --git a/drivers/irqchip/irq-riscv-aplic-main.c b/drivers/irqchip/irq-riscv-aplic-main.c
index d62a096774c4..f225ac77ea3c 100644
--- a/drivers/irqchip/irq-riscv-aplic-main.c
+++ b/drivers/irqchip/irq-riscv-aplic-main.c
@@ -203,7 +203,7 @@ static int aplic_probe(struct platform_device *pdev)
 	 * otherwise setup APLIC direct mode.
 	 */
 	if (fwnode_property_present(dev->fwnode, "msi-parent"))
-		rc = -ENODEV;
+		rc = aplic_msi_setup(dev, regs);
 	else
 		rc = aplic_direct_setup(dev, regs);
 	if (rc) {
diff --git a/drivers/irqchip/irq-riscv-aplic-main.h b/drivers/irqchip/irq-riscv-aplic-main.h
index 474a04229334..78267ec58098 100644
--- a/drivers/irqchip/irq-riscv-aplic-main.h
+++ b/drivers/irqchip/irq-riscv-aplic-main.h
@@ -41,5 +41,13 @@ void aplic_init_hw_global(struct aplic_priv *priv, bool msi_mode);
 int aplic_setup_priv(struct aplic_priv *priv, struct device *dev,
 		     void __iomem *regs);
 int aplic_direct_setup(struct device *dev, void __iomem *regs);
+#ifdef CONFIG_RISCV_APLIC_MSI
+int aplic_msi_setup(struct device *dev, void __iomem *regs);
+#else
+static inline int aplic_msi_setup(struct device *dev, void __iomem *regs)
+{
+	return -ENODEV;
+}
+#endif
 
 #endif
diff --git a/drivers/irqchip/irq-riscv-aplic-msi.c b/drivers/irqchip/irq-riscv-aplic-msi.c
new file mode 100644
index 000000000000..086d00e0429e
--- /dev/null
+++ b/drivers/irqchip/irq-riscv-aplic-msi.c
@@ -0,0 +1,285 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+
+#include <linux/bitops.h>
+#include <linux/cpu.h>
+#include <linux/interrupt.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/riscv-aplic.h>
+#include <linux/irqchip/riscv-imsic.h>
+#include <linux/module.h>
+#include <linux/msi.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/printk.h>
+#include <linux/smp.h>
+
+#include "irq-riscv-aplic-main.h"
+
+static void aplic_msi_irq_unmask(struct irq_data *d)
+{
+	aplic_irq_unmask(d);
+	irq_chip_unmask_parent(d);
+}
+
+static void aplic_msi_irq_mask(struct irq_data *d)
+{
+	aplic_irq_mask(d);
+	irq_chip_mask_parent(d);
+}
+
+static void aplic_msi_irq_eoi(struct irq_data *d)
+{
+	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
+	u32 reg_off, reg_mask;
+
+	/*
+	 * EOI handling only required only for level-triggered
+	 * interrupts in APLIC MSI mode.
+	 */
+
+	reg_off = APLIC_CLRIP_BASE + ((d->hwirq / APLIC_IRQBITS_PER_REG) * 4);
+	reg_mask = BIT(d->hwirq % APLIC_IRQBITS_PER_REG);
+	switch (irqd_get_trigger_type(d)) {
+	case IRQ_TYPE_LEVEL_LOW:
+		if (!(readl(priv->regs + reg_off) & reg_mask))
+			writel(d->hwirq, priv->regs + APLIC_SETIPNUM_LE);
+		break;
+	case IRQ_TYPE_LEVEL_HIGH:
+		if (readl(priv->regs + reg_off) & reg_mask)
+			writel(d->hwirq, priv->regs + APLIC_SETIPNUM_LE);
+		break;
+	}
+}
+
+static struct irq_chip aplic_msi_chip = {
+	.name		= "APLIC-MSI",
+	.irq_mask	= aplic_msi_irq_mask,
+	.irq_unmask	= aplic_msi_irq_unmask,
+	.irq_set_type	= aplic_irq_set_type,
+	.irq_eoi	= aplic_msi_irq_eoi,
+#ifdef CONFIG_SMP
+	.irq_set_affinity = irq_chip_set_affinity_parent,
+#endif
+	.flags		= IRQCHIP_SET_TYPE_MASKED |
+			  IRQCHIP_SKIP_SET_WAKE |
+			  IRQCHIP_MASK_ON_SUSPEND,
+};
+
+static int aplic_msi_irqdomain_translate(struct irq_domain *d,
+					 struct irq_fwspec *fwspec,
+					 unsigned long *hwirq,
+					 unsigned int *type)
+{
+	struct aplic_priv *priv = platform_msi_get_host_data(d);
+
+	return aplic_irqdomain_translate(fwspec, priv->gsi_base, hwirq, type);
+}
+
+static int aplic_msi_irqdomain_alloc(struct irq_domain *domain,
+				     unsigned int virq, unsigned int nr_irqs,
+				     void *arg)
+{
+	int i, ret;
+	unsigned int type;
+	irq_hw_number_t hwirq;
+	struct irq_fwspec *fwspec = arg;
+	struct aplic_priv *priv = platform_msi_get_host_data(domain);
+
+	ret = aplic_irqdomain_translate(fwspec, priv->gsi_base, &hwirq, &type);
+	if (ret)
+		return ret;
+
+	ret = platform_msi_device_domain_alloc(domain, virq, nr_irqs);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < nr_irqs; i++) {
+		irq_domain_set_info(domain, virq + i, hwirq + i,
+				    &aplic_msi_chip, priv, handle_fasteoi_irq,
+				    NULL, NULL);
+		/*
+		 * APLIC does not implement irq_disable() so Linux interrupt
+		 * subsystem will take a lazy approach for disabling an APLIC
+		 * interrupt. This means APLIC interrupts are left unmasked
+		 * upon system suspend and interrupts are not processed
+		 * immediately upon system wake up. To tackle this, we disable
+		 * the lazy approach for all APLIC interrupts.
+		 */
+		irq_set_status_flags(virq + i, IRQ_DISABLE_UNLAZY);
+	}
+
+	return 0;
+}
+
+static const struct irq_domain_ops aplic_msi_irqdomain_ops = {
+	.translate	= aplic_msi_irqdomain_translate,
+	.alloc		= aplic_msi_irqdomain_alloc,
+	.free		= platform_msi_device_domain_free,
+};
+
+static void aplic_msi_write_msg(struct msi_desc *desc, struct msi_msg *msg)
+{
+	unsigned int group_index, hart_index, guest_index, val;
+	struct irq_data *d = irq_get_irq_data(desc->irq);
+	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
+	struct aplic_msicfg *mc = &priv->msicfg;
+	phys_addr_t tppn, tbppn, msg_addr;
+	void __iomem *target;
+
+	/* For zeroed MSI, simply write zero into the target register */
+	if (!msg->address_hi && !msg->address_lo && !msg->data) {
+		target = priv->regs + APLIC_TARGET_BASE;
+		target += (d->hwirq - 1) * sizeof(u32);
+		writel(0, target);
+		return;
+	}
+
+	/* Sanity check on message data */
+	WARN_ON(msg->data > APLIC_TARGET_EIID_MASK);
+
+	/* Compute target MSI address */
+	msg_addr = (((u64)msg->address_hi) << 32) | msg->address_lo;
+	tppn = msg_addr >> APLIC_xMSICFGADDR_PPN_SHIFT;
+
+	/* Compute target HART Base PPN */
+	tbppn = tppn;
+	tbppn &= ~APLIC_xMSICFGADDR_PPN_HART(mc->lhxs);
+	tbppn &= ~APLIC_xMSICFGADDR_PPN_LHX(mc->lhxw, mc->lhxs);
+	tbppn &= ~APLIC_xMSICFGADDR_PPN_HHX(mc->hhxw, mc->hhxs);
+	WARN_ON(tbppn != mc->base_ppn);
+
+	/* Compute target group and hart indexes */
+	group_index = (tppn >> APLIC_xMSICFGADDR_PPN_HHX_SHIFT(mc->hhxs)) &
+		     APLIC_xMSICFGADDR_PPN_HHX_MASK(mc->hhxw);
+	hart_index = (tppn >> APLIC_xMSICFGADDR_PPN_LHX_SHIFT(mc->lhxs)) &
+		     APLIC_xMSICFGADDR_PPN_LHX_MASK(mc->lhxw);
+	hart_index |= (group_index << mc->lhxw);
+	WARN_ON(hart_index > APLIC_TARGET_HART_IDX_MASK);
+
+	/* Compute target guest index */
+	guest_index = tppn & APLIC_xMSICFGADDR_PPN_HART(mc->lhxs);
+	WARN_ON(guest_index > APLIC_TARGET_GUEST_IDX_MASK);
+
+	/* Update IRQ TARGET register */
+	target = priv->regs + APLIC_TARGET_BASE;
+	target += (d->hwirq - 1) * sizeof(u32);
+	val = (hart_index & APLIC_TARGET_HART_IDX_MASK)
+				<< APLIC_TARGET_HART_IDX_SHIFT;
+	val |= (guest_index & APLIC_TARGET_GUEST_IDX_MASK)
+				<< APLIC_TARGET_GUEST_IDX_SHIFT;
+	val |= (msg->data & APLIC_TARGET_EIID_MASK);
+	writel(val, target);
+}
+
+int aplic_msi_setup(struct device *dev, void __iomem *regs)
+{
+	const struct imsic_global_config *imsic_global;
+	struct irq_domain *irqdomain;
+	struct aplic_priv *priv;
+	struct aplic_msicfg *mc;
+	phys_addr_t pa;
+	int rc;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	rc = aplic_setup_priv(priv, dev, regs);
+	if (!priv) {
+		dev_err(dev, "failed to create APLIC context\n");
+		return rc;
+	}
+	mc = &priv->msicfg;
+
+	/*
+	 * The APLIC outgoing MSI config registers assume target MSI
+	 * controller to be RISC-V AIA IMSIC controller.
+	 */
+	imsic_global = imsic_get_global_config();
+	if (!imsic_global) {
+		dev_err(dev, "IMSIC global config not found\n");
+		return -ENODEV;
+	}
+
+	/* Find number of guest index bits (LHXS) */
+	mc->lhxs = imsic_global->guest_index_bits;
+	if (APLIC_xMSICFGADDRH_LHXS_MASK < mc->lhxs) {
+		dev_err(dev, "IMSIC guest index bits big for APLIC LHXS\n");
+		return -EINVAL;
+	}
+
+	/* Find number of HART index bits (LHXW) */
+	mc->lhxw = imsic_global->hart_index_bits;
+	if (APLIC_xMSICFGADDRH_LHXW_MASK < mc->lhxw) {
+		dev_err(dev, "IMSIC hart index bits big for APLIC LHXW\n");
+		return -EINVAL;
+	}
+
+	/* Find number of group index bits (HHXW) */
+	mc->hhxw = imsic_global->group_index_bits;
+	if (APLIC_xMSICFGADDRH_HHXW_MASK < mc->hhxw) {
+		dev_err(dev, "IMSIC group index bits big for APLIC HHXW\n");
+		return -EINVAL;
+	}
+
+	/* Find first bit position of group index (HHXS) */
+	mc->hhxs = imsic_global->group_index_shift;
+	if (mc->hhxs < (2 * APLIC_xMSICFGADDR_PPN_SHIFT)) {
+		dev_err(dev, "IMSIC group index shift should be >= %d\n",
+			(2 * APLIC_xMSICFGADDR_PPN_SHIFT));
+		return -EINVAL;
+	}
+	mc->hhxs -= (2 * APLIC_xMSICFGADDR_PPN_SHIFT);
+	if (APLIC_xMSICFGADDRH_HHXS_MASK < mc->hhxs) {
+		dev_err(dev, "IMSIC group index shift big for APLIC HHXS\n");
+		return -EINVAL;
+	}
+
+	/* Compute PPN base */
+	mc->base_ppn = imsic_global->base_addr >> APLIC_xMSICFGADDR_PPN_SHIFT;
+	mc->base_ppn &= ~APLIC_xMSICFGADDR_PPN_HART(mc->lhxs);
+	mc->base_ppn &= ~APLIC_xMSICFGADDR_PPN_LHX(mc->lhxw, mc->lhxs);
+	mc->base_ppn &= ~APLIC_xMSICFGADDR_PPN_HHX(mc->hhxw, mc->hhxs);
+
+	/* Setup global config and interrupt delivery */
+	aplic_init_hw_global(priv, true);
+
+	/* Set the APLIC device MSI domain if not available */
+	if (!dev_get_msi_domain(dev)) {
+		/*
+		 * The device MSI domain for OF devices is only set at the
+		 * time of populating/creating OF device. If the device MSI
+		 * domain is discovered later after the OF device is created
+		 * then we need to set it explicitly before using any platform
+		 * MSI functions.
+		 *
+		 * In case of APLIC device, the parent MSI domain is always
+		 * IMSIC and the IMSIC MSI domains are created later through
+		 * the platform driver probing so we set it explicitly here.
+		 */
+		if (is_of_node(dev->fwnode))
+			of_msi_configure(dev, to_of_node(dev->fwnode));
+	}
+
+	/* Create irq domain instance for the APLIC MSI-mode */
+	irqdomain = platform_msi_create_device_domain(
+						dev, priv->nr_irqs + 1,
+						aplic_msi_write_msg,
+						&aplic_msi_irqdomain_ops,
+						priv);
+	if (!irqdomain) {
+		dev_err(dev, "failed to create MSI irq domain\n");
+		return -ENOMEM;
+	}
+
+	/* Advertise the interrupt controller */
+	pa = priv->msicfg.base_ppn << APLIC_xMSICFGADDR_PPN_SHIFT;
+	dev_info(dev, "%d interrupts forwared to MSI base %pa\n",
+		 priv->nr_irqs, &pa);
+
+	return 0;
+}
-- 
2.34.1


_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

[PATCH v8 14/16] irqchip/riscv-aplic: Add support for MSI-mode

[Anup Patel]

The RISC-V advanced platform-level interrupt controller (APLIC) has
two modes of operation: 1) Direct mode and 2) MSI mode.
(For more details, refer https://github.com/riscv/riscv-aia)

In APLIC MSI-mode, wired interrupts are forwared as message signaled
interrupts (MSIs) to CPUs via IMSIC.

We extend the existing APLIC irqchip driver to support MSI-mode for
RISC-V platforms having both wired interrupts and MSIs.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 drivers/irqchip/Kconfig                |   6 +
 drivers/irqchip/Makefile               |   1 +
 drivers/irqchip/irq-riscv-aplic-main.c |   2 +-
 drivers/irqchip/irq-riscv-aplic-main.h |   8 +
 drivers/irqchip/irq-riscv-aplic-msi.c  | 285 +++++++++++++++++++++++++
 5 files changed, 301 insertions(+), 1 deletion(-)
 create mode 100644 drivers/irqchip/irq-riscv-aplic-msi.c

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 44c455084d09..31c069bf7343 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -550,6 +550,12 @@ config RISCV_APLIC
 	depends on RISCV
 	select IRQ_DOMAIN_HIERARCHY
 
+config RISCV_APLIC_MSI
+	bool
+	depends on RISCV_APLIC
+	select GENERIC_MSI_IRQ
+	default RISCV_APLIC
+
 config RISCV_IMSIC
 	bool
 	depends on RISCV
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 7f8289790ed8..47995fdb2c60 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -96,6 +96,7 @@ obj-$(CONFIG_CSKY_MPINTC)		+= irq-csky-mpintc.o
 obj-$(CONFIG_CSKY_APB_INTC)		+= irq-csky-apb-intc.o
 obj-$(CONFIG_RISCV_INTC)		+= irq-riscv-intc.o
 obj-$(CONFIG_RISCV_APLIC)		+= irq-riscv-aplic-main.o irq-riscv-aplic-direct.o
+obj-$(CONFIG_RISCV_APLIC_MSI)		+= irq-riscv-aplic-msi.o
 obj-$(CONFIG_RISCV_IMSIC)		+= irq-riscv-imsic-state.o irq-riscv-imsic-early.o irq-riscv-imsic-platform.o
 obj-$(CONFIG_SIFIVE_PLIC)		+= irq-sifive-plic.o
 obj-$(CONFIG_IMX_IRQSTEER)		+= irq-imx-irqsteer.o
diff --git a/drivers/irqchip/irq-riscv-aplic-main.c b/drivers/irqchip/irq-riscv-aplic-main.c
index d62a096774c4..f225ac77ea3c 100644
--- a/drivers/irqchip/irq-riscv-aplic-main.c
+++ b/drivers/irqchip/irq-riscv-aplic-main.c
@@ -203,7 +203,7 @@ static int aplic_probe(struct platform_device *pdev)
 	 * otherwise setup APLIC direct mode.
 	 */
 	if (fwnode_property_present(dev->fwnode, "msi-parent"))
-		rc = -ENODEV;
+		rc = aplic_msi_setup(dev, regs);
 	else
 		rc = aplic_direct_setup(dev, regs);
 	if (rc) {
diff --git a/drivers/irqchip/irq-riscv-aplic-main.h b/drivers/irqchip/irq-riscv-aplic-main.h
index 474a04229334..78267ec58098 100644
--- a/drivers/irqchip/irq-riscv-aplic-main.h
+++ b/drivers/irqchip/irq-riscv-aplic-main.h
@@ -41,5 +41,13 @@ void aplic_init_hw_global(struct aplic_priv *priv, bool msi_mode);
 int aplic_setup_priv(struct aplic_priv *priv, struct device *dev,
 		     void __iomem *regs);
 int aplic_direct_setup(struct device *dev, void __iomem *regs);
+#ifdef CONFIG_RISCV_APLIC_MSI
+int aplic_msi_setup(struct device *dev, void __iomem *regs);
+#else
+static inline int aplic_msi_setup(struct device *dev, void __iomem *regs)
+{
+	return -ENODEV;
+}
+#endif
 
 #endif
diff --git a/drivers/irqchip/irq-riscv-aplic-msi.c b/drivers/irqchip/irq-riscv-aplic-msi.c
new file mode 100644
index 000000000000..086d00e0429e
--- /dev/null
+++ b/drivers/irqchip/irq-riscv-aplic-msi.c
@@ -0,0 +1,285 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (C) 2022 Ventana Micro Systems Inc.
+ */
+
+#include <linux/bitops.h>
+#include <linux/cpu.h>
+#include <linux/interrupt.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/riscv-aplic.h>
+#include <linux/irqchip/riscv-imsic.h>
+#include <linux/module.h>
+#include <linux/msi.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/printk.h>
+#include <linux/smp.h>
+
+#include "irq-riscv-aplic-main.h"
+
+static void aplic_msi_irq_unmask(struct irq_data *d)
+{
+	aplic_irq_unmask(d);
+	irq_chip_unmask_parent(d);
+}
+
+static void aplic_msi_irq_mask(struct irq_data *d)
+{
+	aplic_irq_mask(d);
+	irq_chip_mask_parent(d);
+}
+
+static void aplic_msi_irq_eoi(struct irq_data *d)
+{
+	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
+	u32 reg_off, reg_mask;
+
+	/*
+	 * EOI handling only required only for level-triggered
+	 * interrupts in APLIC MSI mode.
+	 */
+
+	reg_off = APLIC_CLRIP_BASE + ((d->hwirq / APLIC_IRQBITS_PER_REG) * 4);
+	reg_mask = BIT(d->hwirq % APLIC_IRQBITS_PER_REG);
+	switch (irqd_get_trigger_type(d)) {
+	case IRQ_TYPE_LEVEL_LOW:
+		if (!(readl(priv->regs + reg_off) & reg_mask))
+			writel(d->hwirq, priv->regs + APLIC_SETIPNUM_LE);
+		break;
+	case IRQ_TYPE_LEVEL_HIGH:
+		if (readl(priv->regs + reg_off) & reg_mask)
+			writel(d->hwirq, priv->regs + APLIC_SETIPNUM_LE);
+		break;
+	}
+}
+
+static struct irq_chip aplic_msi_chip = {
+	.name		= "APLIC-MSI",
+	.irq_mask	= aplic_msi_irq_mask,
+	.irq_unmask	= aplic_msi_irq_unmask,
+	.irq_set_type	= aplic_irq_set_type,
+	.irq_eoi	= aplic_msi_irq_eoi,
+#ifdef CONFIG_SMP
+	.irq_set_affinity = irq_chip_set_affinity_parent,
+#endif
+	.flags		= IRQCHIP_SET_TYPE_MASKED |
+			  IRQCHIP_SKIP_SET_WAKE |
+			  IRQCHIP_MASK_ON_SUSPEND,
+};
+
+static int aplic_msi_irqdomain_translate(struct irq_domain *d,
+					 struct irq_fwspec *fwspec,
+					 unsigned long *hwirq,
+					 unsigned int *type)
+{
+	struct aplic_priv *priv = platform_msi_get_host_data(d);
+
+	return aplic_irqdomain_translate(fwspec, priv->gsi_base, hwirq, type);
+}
+
+static int aplic_msi_irqdomain_alloc(struct irq_domain *domain,
+				     unsigned int virq, unsigned int nr_irqs,
+				     void *arg)
+{
+	int i, ret;
+	unsigned int type;
+	irq_hw_number_t hwirq;
+	struct irq_fwspec *fwspec = arg;
+	struct aplic_priv *priv = platform_msi_get_host_data(domain);
+
+	ret = aplic_irqdomain_translate(fwspec, priv->gsi_base, &hwirq, &type);
+	if (ret)
+		return ret;
+
+	ret = platform_msi_device_domain_alloc(domain, virq, nr_irqs);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < nr_irqs; i++) {
+		irq_domain_set_info(domain, virq + i, hwirq + i,
+				    &aplic_msi_chip, priv, handle_fasteoi_irq,
+				    NULL, NULL);
+		/*
+		 * APLIC does not implement irq_disable() so Linux interrupt
+		 * subsystem will take a lazy approach for disabling an APLIC
+		 * interrupt. This means APLIC interrupts are left unmasked
+		 * upon system suspend and interrupts are not processed
+		 * immediately upon system wake up. To tackle this, we disable
+		 * the lazy approach for all APLIC interrupts.
+		 */
+		irq_set_status_flags(virq + i, IRQ_DISABLE_UNLAZY);
+	}
+
+	return 0;
+}
+
+static const struct irq_domain_ops aplic_msi_irqdomain_ops = {
+	.translate	= aplic_msi_irqdomain_translate,
+	.alloc		= aplic_msi_irqdomain_alloc,
+	.free		= platform_msi_device_domain_free,
+};
+
+static void aplic_msi_write_msg(struct msi_desc *desc, struct msi_msg *msg)
+{
+	unsigned int group_index, hart_index, guest_index, val;
+	struct irq_data *d = irq_get_irq_data(desc->irq);
+	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
+	struct aplic_msicfg *mc = &priv->msicfg;
+	phys_addr_t tppn, tbppn, msg_addr;
+	void __iomem *target;
+
+	/* For zeroed MSI, simply write zero into the target register */
+	if (!msg->address_hi && !msg->address_lo && !msg->data) {
+		target = priv->regs + APLIC_TARGET_BASE;
+		target += (d->hwirq - 1) * sizeof(u32);
+		writel(0, target);
+		return;
+	}
+
+	/* Sanity check on message data */
+	WARN_ON(msg->data > APLIC_TARGET_EIID_MASK);
+
+	/* Compute target MSI address */
+	msg_addr = (((u64)msg->address_hi) << 32) | msg->address_lo;
+	tppn = msg_addr >> APLIC_xMSICFGADDR_PPN_SHIFT;
+
+	/* Compute target HART Base PPN */
+	tbppn = tppn;
+	tbppn &= ~APLIC_xMSICFGADDR_PPN_HART(mc->lhxs);
+	tbppn &= ~APLIC_xMSICFGADDR_PPN_LHX(mc->lhxw, mc->lhxs);
+	tbppn &= ~APLIC_xMSICFGADDR_PPN_HHX(mc->hhxw, mc->hhxs);
+	WARN_ON(tbppn != mc->base_ppn);
+
+	/* Compute target group and hart indexes */
+	group_index = (tppn >> APLIC_xMSICFGADDR_PPN_HHX_SHIFT(mc->hhxs)) &
+		     APLIC_xMSICFGADDR_PPN_HHX_MASK(mc->hhxw);
+	hart_index = (tppn >> APLIC_xMSICFGADDR_PPN_LHX_SHIFT(mc->lhxs)) &
+		     APLIC_xMSICFGADDR_PPN_LHX_MASK(mc->lhxw);
+	hart_index |= (group_index << mc->lhxw);
+	WARN_ON(hart_index > APLIC_TARGET_HART_IDX_MASK);
+
+	/* Compute target guest index */
+	guest_index = tppn & APLIC_xMSICFGADDR_PPN_HART(mc->lhxs);
+	WARN_ON(guest_index > APLIC_TARGET_GUEST_IDX_MASK);
+
+	/* Update IRQ TARGET register */
+	target = priv->regs + APLIC_TARGET_BASE;
+	target += (d->hwirq - 1) * sizeof(u32);
+	val = (hart_index & APLIC_TARGET_HART_IDX_MASK)
+				<< APLIC_TARGET_HART_IDX_SHIFT;
+	val |= (guest_index & APLIC_TARGET_GUEST_IDX_MASK)
+				<< APLIC_TARGET_GUEST_IDX_SHIFT;
+	val |= (msg->data & APLIC_TARGET_EIID_MASK);
+	writel(val, target);
+}
+
+int aplic_msi_setup(struct device *dev, void __iomem *regs)
+{
+	const struct imsic_global_config *imsic_global;
+	struct irq_domain *irqdomain;
+	struct aplic_priv *priv;
+	struct aplic_msicfg *mc;
+	phys_addr_t pa;
+	int rc;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	rc = aplic_setup_priv(priv, dev, regs);
+	if (!priv) {
+		dev_err(dev, "failed to create APLIC context\n");
+		return rc;
+	}
+	mc = &priv->msicfg;
+
+	/*
+	 * The APLIC outgoing MSI config registers assume target MSI
+	 * controller to be RISC-V AIA IMSIC controller.
+	 */
+	imsic_global = imsic_get_global_config();
+	if (!imsic_global) {
+		dev_err(dev, "IMSIC global config not found\n");
+		return -ENODEV;
+	}
+
+	/* Find number of guest index bits (LHXS) */
+	mc->lhxs = imsic_global->guest_index_bits;
+	if (APLIC_xMSICFGADDRH_LHXS_MASK < mc->lhxs) {
+		dev_err(dev, "IMSIC guest index bits big for APLIC LHXS\n");
+		return -EINVAL;
+	}
+
+	/* Find number of HART index bits (LHXW) */
+	mc->lhxw = imsic_global->hart_index_bits;
+	if (APLIC_xMSICFGADDRH_LHXW_MASK < mc->lhxw) {
+		dev_err(dev, "IMSIC hart index bits big for APLIC LHXW\n");
+		return -EINVAL;
+	}
+
+	/* Find number of group index bits (HHXW) */
+	mc->hhxw = imsic_global->group_index_bits;
+	if (APLIC_xMSICFGADDRH_HHXW_MASK < mc->hhxw) {
+		dev_err(dev, "IMSIC group index bits big for APLIC HHXW\n");
+		return -EINVAL;
+	}
+
+	/* Find first bit position of group index (HHXS) */
+	mc->hhxs = imsic_global->group_index_shift;
+	if (mc->hhxs < (2 * APLIC_xMSICFGADDR_PPN_SHIFT)) {
+		dev_err(dev, "IMSIC group index shift should be >= %d\n",
+			(2 * APLIC_xMSICFGADDR_PPN_SHIFT));
+		return -EINVAL;
+	}
+	mc->hhxs -= (2 * APLIC_xMSICFGADDR_PPN_SHIFT);
+	if (APLIC_xMSICFGADDRH_HHXS_MASK < mc->hhxs) {
+		dev_err(dev, "IMSIC group index shift big for APLIC HHXS\n");
+		return -EINVAL;
+	}
+
+	/* Compute PPN base */
+	mc->base_ppn = imsic_global->base_addr >> APLIC_xMSICFGADDR_PPN_SHIFT;
+	mc->base_ppn &= ~APLIC_xMSICFGADDR_PPN_HART(mc->lhxs);
+	mc->base_ppn &= ~APLIC_xMSICFGADDR_PPN_LHX(mc->lhxw, mc->lhxs);
+	mc->base_ppn &= ~APLIC_xMSICFGADDR_PPN_HHX(mc->hhxw, mc->hhxs);
+
+	/* Setup global config and interrupt delivery */
+	aplic_init_hw_global(priv, true);
+
+	/* Set the APLIC device MSI domain if not available */
+	if (!dev_get_msi_domain(dev)) {
+		/*
+		 * The device MSI domain for OF devices is only set at the
+		 * time of populating/creating OF device. If the device MSI
+		 * domain is discovered later after the OF device is created
+		 * then we need to set it explicitly before using any platform
+		 * MSI functions.
+		 *
+		 * In case of APLIC device, the parent MSI domain is always
+		 * IMSIC and the IMSIC MSI domains are created later through
+		 * the platform driver probing so we set it explicitly here.
+		 */
+		if (is_of_node(dev->fwnode))
+			of_msi_configure(dev, to_of_node(dev->fwnode));
+	}
+
+	/* Create irq domain instance for the APLIC MSI-mode */
+	irqdomain = platform_msi_create_device_domain(
+						dev, priv->nr_irqs + 1,
+						aplic_msi_write_msg,
+						&aplic_msi_irqdomain_ops,
+						priv);
+	if (!irqdomain) {
+		dev_err(dev, "failed to create MSI irq domain\n");
+		return -ENOMEM;
+	}
+
+	/* Advertise the interrupt controller */
+	pa = priv->msicfg.base_ppn << APLIC_xMSICFGADDR_PPN_SHIFT;
+	dev_info(dev, "%d interrupts forwared to MSI base %pa\n",
+		 priv->nr_irqs, &pa);
+
+	return 0;
+}
-- 
2.34.1

[PATCH v8 15/16] RISC-V: Select APLIC and IMSIC drivers

[Anup Patel]

The QEMU virt machine supports AIA emulation and we also have
quite a few RISC-V platforms with AIA support under development
so let us select APLIC and IMSIC drivers for all RISC-V platforms.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
---
 arch/riscv/Kconfig | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index d607ab0f7c6d..45c660f1219d 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -153,6 +153,8 @@ config RISCV
 	select PCI_DOMAINS_GENERIC if PCI
 	select PCI_MSI if PCI
 	select RISCV_ALTERNATIVE if !XIP_KERNEL
+	select RISCV_APLIC
+	select RISCV_IMSIC
 	select RISCV_INTC
 	select RISCV_TIMER if RISCV_SBI
 	select SIFIVE_PLIC
-- 
2.34.1


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[PATCH v8 15/16] RISC-V: Select APLIC and IMSIC drivers

[Anup Patel]

The QEMU virt machine supports AIA emulation and we also have
quite a few RISC-V platforms with AIA support under development
so let us select APLIC and IMSIC drivers for all RISC-V platforms.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
---
 arch/riscv/Kconfig | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index d607ab0f7c6d..45c660f1219d 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -153,6 +153,8 @@ config RISCV
 	select PCI_DOMAINS_GENERIC if PCI
 	select PCI_MSI if PCI
 	select RISCV_ALTERNATIVE if !XIP_KERNEL
+	select RISCV_APLIC
+	select RISCV_IMSIC
 	select RISCV_INTC
 	select RISCV_TIMER if RISCV_SBI
 	select SIFIVE_PLIC
-- 
2.34.1

[PATCH v8 16/16] MAINTAINERS: Add entry for RISC-V AIA drivers

[Anup Patel]

Add myself as maintainer for RISC-V AIA drivers including the
RISC-V INTC driver which supports both AIA and non-AIA platforms.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 MAINTAINERS | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 90f13281d297..6f331ac31d27 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -18410,6 +18410,20 @@ S:	Maintained
 F:	drivers/mtd/nand/raw/r852.c
 F:	drivers/mtd/nand/raw/r852.h
 
+RISC-V AIA DRIVERS
+M:	Anup Patel <anup@brainfault.org>
+L:	linux-riscv@lists.infradead.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/interrupt-controller/riscv,aplic.yaml
+F:	Documentation/devicetree/bindings/interrupt-controller/riscv,imsics.yaml
+F:	drivers/irqchip/irq-riscv-aplic-*.c
+F:	drivers/irqchip/irq-riscv-aplic-*.h
+F:	drivers/irqchip/irq-riscv-imsic-*.c
+F:	drivers/irqchip/irq-riscv-imsic-*.h
+F:	drivers/irqchip/irq-riscv-intc.c
+F:	include/linux/irqchip/riscv-aplic.h
+F:	include/linux/irqchip/riscv-imsic.h
+
 RISC-V ARCHITECTURE
 M:	Paul Walmsley <paul.walmsley@sifive.com>
 M:	Palmer Dabbelt <palmer@dabbelt.com>
-- 
2.34.1


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[PATCH v8 16/16] MAINTAINERS: Add entry for RISC-V AIA drivers

[Anup Patel]

Add myself as maintainer for RISC-V AIA drivers including the
RISC-V INTC driver which supports both AIA and non-AIA platforms.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
---
 MAINTAINERS | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 90f13281d297..6f331ac31d27 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -18410,6 +18410,20 @@ S:	Maintained
 F:	drivers/mtd/nand/raw/r852.c
 F:	drivers/mtd/nand/raw/r852.h
 
+RISC-V AIA DRIVERS
+M:	Anup Patel <anup@brainfault.org>
+L:	linux-riscv@lists.infradead.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/interrupt-controller/riscv,aplic.yaml
+F:	Documentation/devicetree/bindings/interrupt-controller/riscv,imsics.yaml
+F:	drivers/irqchip/irq-riscv-aplic-*.c
+F:	drivers/irqchip/irq-riscv-aplic-*.h
+F:	drivers/irqchip/irq-riscv-imsic-*.c
+F:	drivers/irqchip/irq-riscv-imsic-*.h
+F:	drivers/irqchip/irq-riscv-intc.c
+F:	include/linux/irqchip/riscv-aplic.h
+F:	include/linux/irqchip/riscv-imsic.h
+
 RISC-V ARCHITECTURE
 M:	Paul Walmsley <paul.walmsley@sifive.com>
 M:	Palmer Dabbelt <palmer@dabbelt.com>
-- 
2.34.1

Re: [PATCH v8 03/16] of: property: Add fw_devlink support for msi-parent

[Saravana Kannan]

On Tue, Sep 12, 2023 at 10:50 AM Anup Patel <apatel@ventanamicro.com> wrote:
>
> This allows fw_devlink to create device links between consumers of
> a MSI and the supplier of the MSI.
>
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> ---
>  drivers/of/property.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/of/property.c b/drivers/of/property.c
> index cf8dacf3e3b8..758ea822e46d 100644
> --- a/drivers/of/property.c
> +++ b/drivers/of/property.c
> @@ -1267,6 +1267,7 @@ DEFINE_SIMPLE_PROP(resets, "resets", "#reset-cells")
>  DEFINE_SIMPLE_PROP(leds, "leds", NULL)
>  DEFINE_SIMPLE_PROP(backlight, "backlight", NULL)
>  DEFINE_SIMPLE_PROP(panel, "panel", NULL)
> +DEFINE_SIMPLE_PROP(msi_parent, "msi-parent", "#msi-cells")
>  DEFINE_SUFFIX_PROP(regulators, "-supply", NULL)
>  DEFINE_SUFFIX_PROP(gpio, "-gpio", "#gpio-cells")
>
> @@ -1361,6 +1362,7 @@ static const struct supplier_bindings of_supplier_bindings[] = {
>         { .parse_prop = parse_regulators, },
>         { .parse_prop = parse_gpio, },
>         { .parse_prop = parse_gpios, },
> +       { .parse_prop = parse_msi_parent, },

Please follow the same ordering here as the DEFINE_SIMPLE_PROP macros.
So, this should come after the panel one.

-Saravana

Re: [PATCH v8 03/16] of: property: Add fw_devlink support for msi-parent

[Saravana Kannan]

On Tue, Sep 12, 2023 at 10:50 AM Anup Patel <apatel@ventanamicro.com> wrote:
>
> This allows fw_devlink to create device links between consumers of
> a MSI and the supplier of the MSI.
>
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> ---
>  drivers/of/property.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/of/property.c b/drivers/of/property.c
> index cf8dacf3e3b8..758ea822e46d 100644
> --- a/drivers/of/property.c
> +++ b/drivers/of/property.c
> @@ -1267,6 +1267,7 @@ DEFINE_SIMPLE_PROP(resets, "resets", "#reset-cells")
>  DEFINE_SIMPLE_PROP(leds, "leds", NULL)
>  DEFINE_SIMPLE_PROP(backlight, "backlight", NULL)
>  DEFINE_SIMPLE_PROP(panel, "panel", NULL)
> +DEFINE_SIMPLE_PROP(msi_parent, "msi-parent", "#msi-cells")
>  DEFINE_SUFFIX_PROP(regulators, "-supply", NULL)
>  DEFINE_SUFFIX_PROP(gpio, "-gpio", "#gpio-cells")
>
> @@ -1361,6 +1362,7 @@ static const struct supplier_bindings of_supplier_bindings[] = {
>         { .parse_prop = parse_regulators, },
>         { .parse_prop = parse_gpio, },
>         { .parse_prop = parse_gpios, },
> +       { .parse_prop = parse_msi_parent, },

Please follow the same ordering here as the DEFINE_SIMPLE_PROP macros.
So, this should come after the panel one.

-Saravana

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Re: [PATCH v8 09/16] irqchip: Add RISC-V incoming MSI controller early driver

[Emil Renner Berthing]

Anup Patel wrote:
> The RISC-V advanced interrupt architecture (AIA) specification
> defines a new MSI controller called incoming message signalled
> interrupt controller (IMSIC) which manages MSI on per-HART (or
> per-CPU) basis. It also supports IPIs as software injected MSIs.
> (For more details refer https://github.com/riscv/riscv-aia)
>
> Let us add an early irqchip driver for RISC-V IMSIC which sets
> up the IMSIC state and provide IPIs.
>
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> ---
>  drivers/irqchip/Kconfig                 |   7 +-
>  drivers/irqchip/Makefile                |   1 +
>  drivers/irqchip/irq-riscv-imsic-early.c | 258 ++++++++++++
>  drivers/irqchip/irq-riscv-imsic-state.c | 523 ++++++++++++++++++++++++
>  drivers/irqchip/irq-riscv-imsic-state.h |  66 +++
>  include/linux/irqchip/riscv-imsic.h     |  86 ++++
>  6 files changed, 940 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/irqchip/irq-riscv-imsic-early.c
>  create mode 100644 drivers/irqchip/irq-riscv-imsic-state.c
>  create mode 100644 drivers/irqchip/irq-riscv-imsic-state.h
>  create mode 100644 include/linux/irqchip/riscv-imsic.h
>
> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> index f7149d0f3d45..ee99aacbefcc 100644
> --- a/drivers/irqchip/Kconfig
> +++ b/drivers/irqchip/Kconfig
> @@ -30,7 +30,6 @@ config ARM_GIC_V2M
>
>  config GIC_NON_BANKED
>  	bool
> -

Hi Anup,

This change looks like a mistake to me.

/Emil

>  config ARM_GIC_V3
>  	bool
>  	select IRQ_DOMAIN_HIERARCHY
> @@ -546,6 +545,12 @@ config SIFIVE_PLIC
>  	select IRQ_DOMAIN_HIERARCHY
>  	select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
>
> +config RISCV_IMSIC
> +	bool
> +	depends on RISCV
> +	select IRQ_DOMAIN_HIERARCHY
> +	select GENERIC_MSI_IRQ
> +
>  config EXYNOS_IRQ_COMBINER
>  	bool "Samsung Exynos IRQ combiner support" if COMPILE_TEST
>  	depends on (ARCH_EXYNOS && ARM) || COMPILE_TEST
> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index ffd945fe71aa..d714724387ce 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -95,6 +95,7 @@ obj-$(CONFIG_QCOM_MPM)			+= irq-qcom-mpm.o
>  obj-$(CONFIG_CSKY_MPINTC)		+= irq-csky-mpintc.o
>  obj-$(CONFIG_CSKY_APB_INTC)		+= irq-csky-apb-intc.o
>  obj-$(CONFIG_RISCV_INTC)		+= irq-riscv-intc.o
> +obj-$(CONFIG_RISCV_IMSIC)		+= irq-riscv-imsic-state.o irq-riscv-imsic-early.o
>  obj-$(CONFIG_SIFIVE_PLIC)		+= irq-sifive-plic.o
>  obj-$(CONFIG_IMX_IRQSTEER)		+= irq-imx-irqsteer.o
>  obj-$(CONFIG_IMX_INTMUX)		+= irq-imx-intmux.o
> diff --git a/drivers/irqchip/irq-riscv-imsic-early.c b/drivers/irqchip/irq-riscv-imsic-early.c
> new file mode 100644
> index 000000000000..1de89ce1ec2f
> --- /dev/null
> +++ b/drivers/irqchip/irq-riscv-imsic-early.c
> @@ -0,0 +1,258 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> + * Copyright (C) 2022 Ventana Micro Systems Inc.
> + */
> +
> +#define pr_fmt(fmt) "riscv-imsic: " fmt
> +#include <linux/cpu.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/irq.h>
> +#include <linux/irqchip.h>
> +#include <linux/irqchip/chained_irq.h>
> +#include <linux/module.h>
> +#include <linux/spinlock.h>
> +#include <linux/smp.h>
> +
> +#include "irq-riscv-imsic-state.h"
> +
> +/*
> + * The IMSIC driver uses 1 IPI for ID synchronization and
> + * arch/riscv/kernel/smp.c require 6 IPIs so we fix the
> + * total number of IPIs to 8.
> + */
> +#define IMSIC_NR_IPI				8
> +
> +static int imsic_parent_irq;
> +
> +#ifdef CONFIG_SMP
> +static irqreturn_t imsic_ids_sync_handler(int irq, void *data)
> +{
> +	imsic_ids_local_sync();
> +	return IRQ_HANDLED;
> +}
> +
> +void imsic_ids_remote_sync(void)
> +{
> +	struct cpumask amask;
> +
> +	/*
> +	 * We simply inject ID synchronization IPI to all target CPUs
> +	 * except current CPU. The ipi_send_mask() implementation of
> +	 * IPI mux will inject ID synchronization IPI only for CPUs
> +	 * that have enabled it so offline CPUs won't receive IPI.
> +	 * An offline CPU will unconditionally synchronize IDs through
> +	 * imsic_starting_cpu() when the CPU is brought up.
> +	 */
> +	cpumask_andnot(&amask, cpu_online_mask, cpumask_of(smp_processor_id()));
> +	__ipi_send_mask(imsic->ipi_lsync_desc, &amask);
> +}
> +
> +static void imsic_ipi_send(unsigned int cpu)
> +{
> +	struct imsic_local_config *local =
> +				per_cpu_ptr(imsic->global.local, cpu);
> +
> +	writel(imsic->ipi_id, local->msi_va);
> +}
> +
> +static void imsic_ipi_starting_cpu(void)
> +{
> +	/* Enable IPIs for current CPU. */
> +	__imsic_id_enable(imsic->ipi_id);
> +
> +	/* Enable virtual IPI used for IMSIC ID synchronization */
> +	enable_percpu_irq(imsic->ipi_virq, 0);
> +}
> +
> +static void imsic_ipi_dying_cpu(void)
> +{
> +	/*
> +	 * Disable virtual IPI used for IMSIC ID synchronization so
> +	 * that we don't receive ID synchronization requests.
> +	 */
> +	disable_percpu_irq(imsic->ipi_virq);
> +}
> +
> +static int __init imsic_ipi_domain_init(void)
> +{
> +	int virq;
> +
> +	/* Allocate interrupt identity for IPIs */
> +	virq = imsic_ids_alloc(get_count_order(1));
> +	if (virq < 0)
> +		return virq;
> +	imsic->ipi_id = virq;
> +
> +	/* Create IMSIC IPI multiplexing */
> +	virq = ipi_mux_create(IMSIC_NR_IPI, imsic_ipi_send);
> +	if (virq <= 0) {
> +		imsic_ids_free(imsic->ipi_id, get_count_order(1));
> +		return (virq < 0) ? virq : -ENOMEM;
> +	}
> +	imsic->ipi_virq = virq;
> +
> +	/* First vIRQ is used for IMSIC ID synchronization */
> +	virq = request_percpu_irq(imsic->ipi_virq, imsic_ids_sync_handler,
> +				  "riscv-imsic-lsync", imsic->global.local);
> +	if (virq) {
> +		imsic_ids_free(imsic->ipi_id, get_count_order(1));
> +		return virq;
> +	}
> +	irq_set_status_flags(imsic->ipi_virq, IRQ_HIDDEN);
> +	imsic->ipi_lsync_desc = irq_to_desc(imsic->ipi_virq);
> +
> +	/* Set vIRQ range */
> +	riscv_ipi_set_virq_range(imsic->ipi_virq + 1, IMSIC_NR_IPI - 1, true);
> +
> +	/* Announce that IMSIC is providing IPIs */
> +	pr_info("%pfwP: providing IPIs using interrupt %d\n",
> +		imsic->fwnode, imsic->ipi_id);
> +
> +	return 0;
> +}
> +#else
> +static void imsic_ipi_starting_cpu(void)
> +{
> +}
> +
> +static void imsic_ipi_dying_cpu(void)
> +{
> +}
> +
> +static int __init imsic_ipi_domain_init(void)
> +{
> +	/* Clear the IPI id because we are not using IPIs */
> +	imsic->ipi_id = 0;
> +	return 0;
> +}
> +#endif
> +
> +/*
> + * To handle an interrupt, we read the TOPEI CSR and write zero in one
> + * instruction. If TOPEI CSR is non-zero then we translate TOPEI.ID to
> + * Linux interrupt number and let Linux IRQ subsystem handle it.
> + */
> +static void imsic_handle_irq(struct irq_desc *desc)
> +{
> +	struct irq_chip *chip = irq_desc_get_chip(desc);
> +	irq_hw_number_t hwirq;
> +	int err;
> +
> +	chained_irq_enter(chip, desc);
> +
> +	while ((hwirq = csr_swap(CSR_TOPEI, 0))) {
> +		hwirq = hwirq >> TOPEI_ID_SHIFT;
> +
> +		if (hwirq == imsic->ipi_id) {
> +#ifdef CONFIG_SMP
> +			ipi_mux_process();
> +#endif
> +			continue;
> +		}
> +
> +		if (unlikely(!imsic->base_domain))
> +			continue;
> +
> +		err = generic_handle_domain_irq(imsic->base_domain, hwirq);
> +		if (unlikely(err))
> +			pr_warn_ratelimited(
> +				"hwirq %lu mapping not found\n", hwirq);
> +	}
> +
> +	chained_irq_exit(chip, desc);
> +}
> +
> +static int imsic_starting_cpu(unsigned int cpu)
> +{
> +	/* Enable per-CPU parent interrupt */
> +	enable_percpu_irq(imsic_parent_irq,
> +			  irq_get_trigger_type(imsic_parent_irq));
> +
> +	/* Setup IPIs */
> +	imsic_ipi_starting_cpu();
> +
> +	/*
> +	 * Interrupts identities might have been enabled/disabled while
> +	 * this CPU was not running so sync-up local enable/disable state.
> +	 */
> +	imsic_ids_local_sync();
> +
> +	/* Enable local interrupt delivery */
> +	imsic_ids_local_delivery(true);
> +
> +	return 0;
> +}
> +
> +static int imsic_dying_cpu(unsigned int cpu)
> +{
> +	/* Cleanup IPIs */
> +	imsic_ipi_dying_cpu();
> +
> +	return 0;
> +}
> +
> +static int __init imsic_early_probe(struct fwnode_handle *fwnode)
> +{
> +	int rc;
> +	struct irq_domain *domain;
> +
> +	/* Setup IMSIC state */
> +	rc = imsic_setup_state(fwnode);
> +	if (rc) {
> +		pr_err("%pfwP: failed to setup state (error %d)\n",
> +			fwnode, rc);
> +		return rc;
> +	}
> +
> +	/* Find parent domain and register chained handler */
> +	domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
> +					  DOMAIN_BUS_ANY);
> +	if (!domain) {
> +		pr_err("%pfwP: Failed to find INTC domain\n", fwnode);
> +		return -ENOENT;
> +	}
> +	imsic_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT);
> +	if (!imsic_parent_irq) {
> +		pr_err("%pfwP: Failed to create INTC mapping\n", fwnode);
> +		return -ENOENT;
> +	}
> +	irq_set_chained_handler(imsic_parent_irq, imsic_handle_irq);
> +
> +	/* Initialize IPI domain */
> +	rc = imsic_ipi_domain_init();
> +	if (rc) {
> +		pr_err("%pfwP: Failed to initialize IPI domain\n", fwnode);
> +		return rc;
> +	}
> +
> +	/*
> +	 * Setup cpuhp state (must be done after setting imsic_parent_irq)
> +	 *
> +	 * Don't disable per-CPU IMSIC file when CPU goes offline
> +	 * because this affects IPI and the masking/unmasking of
> +	 * virtual IPIs is done via generic IPI-Mux
> +	 */
> +	cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
> +			  "irqchip/riscv/imsic:starting",
> +			  imsic_starting_cpu, imsic_dying_cpu);
> +
> +	return 0;
> +}
> +
> +static int __init imsic_early_dt_init(struct device_node *node,
> +				      struct device_node *parent)
> +{
> +	int rc;
> +
> +	/* Do early setup of IMSIC state and IPIs */
> +	rc = imsic_early_probe(&node->fwnode);
> +	if (rc)
> +		return rc;
> +
> +	/* Ensure that OF platform device gets probed */
> +	of_node_clear_flag(node, OF_POPULATED);
> +	return 0;
> +}
> +IRQCHIP_DECLARE(riscv_imsic, "riscv,imsics", imsic_early_dt_init);
> diff --git a/drivers/irqchip/irq-riscv-imsic-state.c b/drivers/irqchip/irq-riscv-imsic-state.c
> new file mode 100644
> index 000000000000..412b5b919dcc
> --- /dev/null
> +++ b/drivers/irqchip/irq-riscv-imsic-state.c
> @@ -0,0 +1,523 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> + * Copyright (C) 2022 Ventana Micro Systems Inc.
> + */
> +
> +#define pr_fmt(fmt) "riscv-imsic: " fmt
> +#include <linux/bitmap.h>
> +#include <linux/module.h>
> +#include <linux/of_address.h>
> +#include <linux/spinlock.h>
> +#include <linux/smp.h>
> +#include <asm/hwcap.h>
> +
> +#include "irq-riscv-imsic-state.h"
> +
> +#define IMSIC_DISABLE_EIDELIVERY		0
> +#define IMSIC_ENABLE_EIDELIVERY			1
> +#define IMSIC_DISABLE_EITHRESHOLD		1
> +#define IMSIC_ENABLE_EITHRESHOLD		0
> +
> +#define imsic_csr_write(__c, __v)		\
> +do {						\
> +	csr_write(CSR_ISELECT, __c);		\
> +	csr_write(CSR_IREG, __v);		\
> +} while (0)
> +
> +#define imsic_csr_read(__c)			\
> +({						\
> +	unsigned long __v;			\
> +	csr_write(CSR_ISELECT, __c);		\
> +	__v = csr_read(CSR_IREG);		\
> +	__v;					\
> +})
> +
> +#define imsic_csr_set(__c, __v)			\
> +do {						\
> +	csr_write(CSR_ISELECT, __c);		\
> +	csr_set(CSR_IREG, __v);			\
> +} while (0)
> +
> +#define imsic_csr_clear(__c, __v)		\
> +do {						\
> +	csr_write(CSR_ISELECT, __c);		\
> +	csr_clear(CSR_IREG, __v);		\
> +} while (0)
> +
> +struct imsic_priv *imsic;
> +
> +const struct imsic_global_config *imsic_get_global_config(void)
> +{
> +	return (imsic) ? &imsic->global : NULL;
> +}
> +EXPORT_SYMBOL_GPL(imsic_get_global_config);
> +
> +void __imsic_eix_update(unsigned long base_id,
> +			unsigned long num_id, bool pend, bool val)
> +{
> +	unsigned long i, isel, ireg;
> +	unsigned long id = base_id, last_id = base_id + num_id;
> +
> +	while (id < last_id) {
> +		isel = id / BITS_PER_LONG;
> +		isel *= BITS_PER_LONG / IMSIC_EIPx_BITS;
> +		isel += (pend) ? IMSIC_EIP0 : IMSIC_EIE0;
> +
> +		ireg = 0;
> +		for (i = id & (__riscv_xlen - 1);
> +		     (id < last_id) && (i < __riscv_xlen); i++) {
> +			ireg |= BIT(i);
> +			id++;
> +		}
> +
> +		/*
> +		 * The IMSIC EIEx and EIPx registers are indirectly
> +		 * accessed via using ISELECT and IREG CSRs so we
> +		 * need to access these CSRs without getting preempted.
> +		 *
> +		 * All existing users of this function call this
> +		 * function with local IRQs disabled so we don't
> +		 * need to do anything special here.
> +		 */
> +		if (val)
> +			imsic_csr_set(isel, ireg);
> +		else
> +			imsic_csr_clear(isel, ireg);
> +	}
> +}
> +
> +void imsic_id_set_target(unsigned int id, unsigned int target_cpu)
> +{
> +	unsigned long flags;
> +
> +	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> +	imsic->ids_target_cpu[id] = target_cpu;
> +	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> +}
> +
> +unsigned int imsic_id_get_target(unsigned int id)
> +{
> +	unsigned int ret;
> +	unsigned long flags;
> +
> +	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> +	ret = imsic->ids_target_cpu[id];
> +	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> +
> +	return ret;
> +}
> +
> +void imsic_ids_local_sync(void)
> +{
> +	int i;
> +	unsigned long flags;
> +
> +	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> +	for (i = 1; i <= imsic->global.nr_ids; i++) {
> +		if (imsic->ipi_id == i)
> +			continue;
> +
> +		if (test_bit(i, imsic->ids_enabled_bimap))
> +			__imsic_id_enable(i);
> +		else
> +			__imsic_id_disable(i);
> +	}
> +	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> +}
> +
> +void imsic_ids_local_delivery(bool enable)
> +{
> +	if (enable) {
> +		imsic_csr_write(IMSIC_EITHRESHOLD, IMSIC_ENABLE_EITHRESHOLD);
> +		imsic_csr_write(IMSIC_EIDELIVERY, IMSIC_ENABLE_EIDELIVERY);
> +	} else {
> +		imsic_csr_write(IMSIC_EIDELIVERY, IMSIC_DISABLE_EIDELIVERY);
> +		imsic_csr_write(IMSIC_EITHRESHOLD, IMSIC_DISABLE_EITHRESHOLD);
> +	}
> +}
> +
> +int imsic_ids_alloc(unsigned int order)
> +{
> +	int ret;
> +	unsigned long flags;
> +
> +	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> +	ret = bitmap_find_free_region(imsic->ids_used_bimap,
> +				      imsic->global.nr_ids + 1, order);
> +	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> +
> +	return ret;
> +}
> +
> +void imsic_ids_free(unsigned int base_id, unsigned int order)
> +{
> +	unsigned long flags;
> +
> +	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> +	bitmap_release_region(imsic->ids_used_bimap, base_id, order);
> +	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> +}
> +
> +static int __init imsic_ids_init(void)
> +{
> +	int i;
> +	struct imsic_global_config *global = &imsic->global;
> +
> +	raw_spin_lock_init(&imsic->ids_lock);
> +
> +	/* Allocate used bitmap */
> +	imsic->ids_used_bimap = bitmap_zalloc(global->nr_ids + 1, GFP_KERNEL);
> +	if (!imsic->ids_used_bimap)
> +		return -ENOMEM;
> +
> +	/* Allocate enabled bitmap */
> +	imsic->ids_enabled_bimap = bitmap_zalloc(global->nr_ids + 1,
> +						GFP_KERNEL);
> +	if (!imsic->ids_enabled_bimap) {
> +		kfree(imsic->ids_used_bimap);
> +		return -ENOMEM;
> +	}
> +
> +	/* Allocate target CPU array */
> +	imsic->ids_target_cpu = kcalloc(global->nr_ids + 1,
> +				       sizeof(unsigned int), GFP_KERNEL);
> +	if (!imsic->ids_target_cpu) {
> +		bitmap_free(imsic->ids_enabled_bimap);
> +		bitmap_free(imsic->ids_used_bimap);
> +		return -ENOMEM;
> +	}
> +	for (i = 0; i <= global->nr_ids; i++)
> +		imsic->ids_target_cpu[i] = UINT_MAX;
> +
> +	/* Reserve ID#0 because it is special and never implemented */
> +	bitmap_set(imsic->ids_used_bimap, 0, 1);
> +
> +	return 0;
> +}
> +
> +static void __init imsic_ids_cleanup(void)
> +{
> +	kfree(imsic->ids_target_cpu);
> +	bitmap_free(imsic->ids_enabled_bimap);
> +	bitmap_free(imsic->ids_used_bimap);
> +}
> +
> +static int __init imsic_get_parent_hartid(struct fwnode_handle *fwnode,
> +					  u32 index, unsigned long *hartid)
> +{
> +	int rc;
> +	struct fwnode_reference_args parent;
> +
> +	rc = fwnode_property_get_reference_args(fwnode,
> +			"interrupts-extended", "#interrupt-cells",
> +			0, index, &parent);
> +	if (rc)
> +		return rc;
> +
> +	/*
> +	 * Skip interrupts other than external interrupts for
> +	 * current privilege level.
> +	 */
> +	if (parent.args[0] != RV_IRQ_EXT)
> +		return -EINVAL;
> +
> +	return riscv_get_intc_hartid(parent.fwnode, hartid);
> +}
> +
> +static int __init imsic_get_mmio_resource(struct fwnode_handle *fwnode,
> +					  u32 index, struct resource *res)
> +{
> +	/*
> +	 * Currently, only OF fwnode is support so extend this function
> +	 * for other types of fwnode for ACPI support.
> +	 */
> +	if (!is_of_node(fwnode))
> +		return -EINVAL;
> +	return of_address_to_resource(to_of_node(fwnode), index, res);
> +}
> +
> +int __init imsic_setup_state(struct fwnode_handle *fwnode)
> +{
> +	int rc, cpu;
> +	phys_addr_t base_addr;
> +	void __iomem **mmios_va = NULL;
> +	struct resource res, *mmios = NULL;
> +	struct imsic_local_config *local;
> +	struct imsic_global_config *global;
> +	unsigned long reloff, hartid;
> +	u32 i, j, index, nr_parent_irqs, nr_handlers = 0, num_mmios = 0;
> +
> +	/*
> +	 * Only one IMSIC instance allowed in a platform for clean
> +	 * implementation of SMP IRQ affinity and per-CPU IPIs.
> +	 *
> +	 * This means on a multi-socket (or multi-die) platform we
> +	 * will have multiple MMIO regions for one IMSIC instance.
> +	 */
> +	if (imsic) {
> +		pr_err("%pfwP: already initialized hence ignoring\n",
> +			fwnode);
> +		return -EALREADY;
> +	}
> +
> +	if (!riscv_isa_extension_available(NULL, SxAIA)) {
> +		pr_err("%pfwP: AIA support not available\n", fwnode);
> +		return -ENODEV;
> +	}
> +
> +	imsic = kzalloc(sizeof(*imsic), GFP_KERNEL);
> +	if (!imsic)
> +		return -ENOMEM;
> +	imsic->fwnode = fwnode;
> +	global = &imsic->global;
> +
> +	global->local = alloc_percpu(typeof(*(global->local)));
> +	if (!global->local) {
> +		rc = -ENOMEM;
> +		goto out_free_priv;
> +	}
> +
> +	/* Find number of parent interrupts */
> +	nr_parent_irqs = 0;
> +	while (!imsic_get_parent_hartid(fwnode, nr_parent_irqs, &hartid))
> +		nr_parent_irqs++;
> +	if (!nr_parent_irqs) {
> +		pr_err("%pfwP: no parent irqs available\n", fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +
> +	/* Find number of guest index bits in MSI address */
> +	rc = fwnode_property_read_u32_array(fwnode, "riscv,guest-index-bits",
> +					    &global->guest_index_bits, 1);
> +	if (rc)
> +		global->guest_index_bits = 0;
> +	i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT;
> +	if (i < global->guest_index_bits) {
> +		pr_err("%pfwP: guest index bits too big\n", fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +
> +	/* Find number of HART index bits */
> +	rc = fwnode_property_read_u32_array(fwnode, "riscv,hart-index-bits",
> +					    &global->hart_index_bits, 1);
> +	if (rc) {
> +		/* Assume default value */
> +		global->hart_index_bits = __fls(nr_parent_irqs);
> +		if (BIT(global->hart_index_bits) < nr_parent_irqs)
> +			global->hart_index_bits++;
> +	}
> +	i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT - global->guest_index_bits;
> +	if (i < global->hart_index_bits) {
> +		pr_err("%pfwP: HART index bits too big\n", fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +
> +	/* Find number of group index bits */
> +	rc = fwnode_property_read_u32_array(fwnode, "riscv,group-index-bits",
> +					    &global->group_index_bits, 1);
> +	if (rc)
> +		global->group_index_bits = 0;
> +	i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT -
> +	    global->guest_index_bits - global->hart_index_bits;
> +	if (i < global->group_index_bits) {
> +		pr_err("%pfwP: group index bits too big\n", fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +
> +	/*
> +	 * Find first bit position of group index.
> +	 * If not specified assumed the default APLIC-IMSIC configuration.
> +	 */
> +	rc = fwnode_property_read_u32_array(fwnode, "riscv,group-index-shift",
> +					    &global->group_index_shift, 1);
> +	if (rc)
> +		global->group_index_shift = IMSIC_MMIO_PAGE_SHIFT * 2;
> +	i = global->group_index_bits + global->group_index_shift - 1;
> +	if (i >= BITS_PER_LONG) {
> +		pr_err("%pfwP: group index shift too big\n", fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +
> +	/* Find number of interrupt identities */
> +	rc = fwnode_property_read_u32_array(fwnode, "riscv,num-ids",
> +					    &global->nr_ids, 1);
> +	if (rc) {
> +		pr_err("%pfwP: number of interrupt identities not found\n",
> +			fwnode);
> +		goto out_free_local;
> +	}
> +	if ((global->nr_ids < IMSIC_MIN_ID) ||
> +	    (global->nr_ids >= IMSIC_MAX_ID) ||
> +	    ((global->nr_ids & IMSIC_MIN_ID) != IMSIC_MIN_ID)) {
> +		pr_err("%pfwP: invalid number of interrupt identities\n",
> +			fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +
> +	/* Find number of guest interrupt identities */
> +	if (fwnode_property_read_u32_array(fwnode, "riscv,num-guest-ids",
> +					   &global->nr_guest_ids, 1))
> +		global->nr_guest_ids = global->nr_ids;
> +	if ((global->nr_guest_ids < IMSIC_MIN_ID) ||
> +	    (global->nr_guest_ids >= IMSIC_MAX_ID) ||
> +	    ((global->nr_guest_ids & IMSIC_MIN_ID) != IMSIC_MIN_ID)) {
> +		pr_err("%pfwP: invalid number of guest interrupt identities\n",
> +			fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +
> +	/* Compute base address */
> +	rc = imsic_get_mmio_resource(fwnode, 0, &res);
> +	if (rc) {
> +		pr_err("%pfwP: first MMIO resource not found\n", fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +	global->base_addr = res.start;
> +	global->base_addr &= ~(BIT(global->guest_index_bits +
> +				   global->hart_index_bits +
> +				   IMSIC_MMIO_PAGE_SHIFT) - 1);
> +	global->base_addr &= ~((BIT(global->group_index_bits) - 1) <<
> +			       global->group_index_shift);
> +
> +	/* Find number of MMIO register sets */
> +	while (!imsic_get_mmio_resource(fwnode, num_mmios, &res))
> +		num_mmios++;
> +
> +	/* Allocate MMIO resource array */
> +	mmios = kcalloc(num_mmios, sizeof(*mmios), GFP_KERNEL);
> +	if (!mmios) {
> +		rc = -ENOMEM;
> +		goto out_free_local;
> +	}
> +
> +	/* Allocate MMIO virtual address array */
> +	mmios_va = kcalloc(num_mmios, sizeof(*mmios_va), GFP_KERNEL);
> +	if (!mmios_va) {
> +		rc = -ENOMEM;
> +		goto out_iounmap;
> +	}
> +
> +	/* Parse and map MMIO register sets */
> +	for (i = 0; i < num_mmios; i++) {
> +		rc = imsic_get_mmio_resource(fwnode, i, &mmios[i]);
> +		if (rc) {
> +			pr_err("%pfwP: unable to parse MMIO regset %d\n",
> +				fwnode, i);
> +			goto out_iounmap;
> +		}
> +
> +		base_addr = mmios[i].start;
> +		base_addr &= ~(BIT(global->guest_index_bits +
> +				   global->hart_index_bits +
> +				   IMSIC_MMIO_PAGE_SHIFT) - 1);
> +		base_addr &= ~((BIT(global->group_index_bits) - 1) <<
> +			       global->group_index_shift);
> +		if (base_addr != global->base_addr) {
> +			rc = -EINVAL;
> +			pr_err("%pfwP: address mismatch for regset %d\n",
> +				fwnode, i);
> +			goto out_iounmap;
> +		}
> +
> +		mmios_va[i] = ioremap(mmios[i].start, resource_size(&mmios[i]));
> +		if (!mmios_va[i]) {
> +			rc = -EIO;
> +			pr_err("%pfwP: unable to map MMIO regset %d\n",
> +				fwnode, i);
> +			goto out_iounmap;
> +		}
> +	}
> +
> +	/* Initialize interrupt identity management */
> +	rc = imsic_ids_init();
> +	if (rc) {
> +		pr_err("%pfwP: failed to initialize interrupt management\n",
> +		       fwnode);
> +		goto out_iounmap;
> +	}
> +
> +	/* Configure handlers for target CPUs */
> +	for (i = 0; i < nr_parent_irqs; i++) {
> +		rc = imsic_get_parent_hartid(fwnode, i, &hartid);
> +		if (rc) {
> +			pr_warn("%pfwP: hart ID for parent irq%d not found\n",
> +				fwnode, i);
> +			continue;
> +		}
> +
> +		cpu = riscv_hartid_to_cpuid(hartid);
> +		if (cpu < 0) {
> +			pr_warn("%pfwP: invalid cpuid for parent irq%d\n",
> +				fwnode, i);
> +			continue;
> +		}
> +
> +		/* Find MMIO location of MSI page */
> +		index = num_mmios;
> +		reloff = i * BIT(global->guest_index_bits) *
> +			 IMSIC_MMIO_PAGE_SZ;
> +		for (j = 0; num_mmios; j++) {
> +			if (reloff < resource_size(&mmios[j])) {
> +				index = j;
> +				break;
> +			}
> +
> +			/*
> +			 * MMIO region size may not be aligned to
> +			 * BIT(global->guest_index_bits) * IMSIC_MMIO_PAGE_SZ
> +			 * if holes are present.
> +			 */
> +			reloff -= ALIGN(resource_size(&mmios[j]),
> +			BIT(global->guest_index_bits) * IMSIC_MMIO_PAGE_SZ);
> +		}
> +		if (index >= num_mmios) {
> +			pr_warn("%pfwP: MMIO not found for parent irq%d\n",
> +				fwnode, i);
> +			continue;
> +		}
> +
> +		local = per_cpu_ptr(global->local, cpu);
> +		local->msi_pa = mmios[index].start + reloff;
> +		local->msi_va = mmios_va[index] + reloff;
> +
> +		nr_handlers++;
> +	}
> +
> +	/* If no CPU handlers found then can't take interrupts */
> +	if (!nr_handlers) {
> +		pr_err("%pfwP: No CPU handlers found\n", fwnode);
> +		rc = -ENODEV;
> +		goto out_ids_cleanup;
> +	}
> +
> +	/* We don't need MMIO arrays anymore so let's free-up */
> +	kfree(mmios_va);
> +	kfree(mmios);
> +
> +	return 0;
> +
> +out_ids_cleanup:
> +	imsic_ids_cleanup();
> +out_iounmap:
> +	for (i = 0; i < num_mmios; i++) {
> +		if (mmios_va[i])
> +			iounmap(mmios_va[i]);
> +	}
> +	kfree(mmios_va);
> +	kfree(mmios);
> +out_free_local:
> +	free_percpu(imsic->global.local);
> +out_free_priv:
> +	kfree(imsic);
> +	imsic = NULL;
> +	return rc;
> +}
> diff --git a/drivers/irqchip/irq-riscv-imsic-state.h b/drivers/irqchip/irq-riscv-imsic-state.h
> new file mode 100644
> index 000000000000..3170018949a8
> --- /dev/null
> +++ b/drivers/irqchip/irq-riscv-imsic-state.h
> @@ -0,0 +1,66 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> + * Copyright (C) 2022 Ventana Micro Systems Inc.
> + */
> +
> +#ifndef _IRQ_RISCV_IMSIC_STATE_H
> +#define _IRQ_RISCV_IMSIC_STATE_H
> +
> +#include <linux/irqchip/riscv-imsic.h>
> +#include <linux/irqdomain.h>
> +#include <linux/fwnode.h>
> +
> +struct imsic_priv {
> +	/* Device details */
> +	struct fwnode_handle *fwnode;
> +
> +	/* Global configuration common for all HARTs */
> +	struct imsic_global_config global;
> +
> +	/* Global state of interrupt identities */
> +	raw_spinlock_t ids_lock;
> +	unsigned long *ids_used_bimap;
> +	unsigned long *ids_enabled_bimap;
> +	unsigned int *ids_target_cpu;
> +
> +	/* IPI interrupt identity and synchronization */
> +	u32 ipi_id;
> +	int ipi_virq;
> +	struct irq_desc *ipi_lsync_desc;
> +
> +	/* IRQ domains (created by platform driver) */
> +	struct irq_domain *base_domain;
> +	struct irq_domain *plat_domain;
> +};
> +
> +extern struct imsic_priv *imsic;
> +
> +void __imsic_eix_update(unsigned long base_id,
> +			unsigned long num_id, bool pend, bool val);
> +
> +#define __imsic_id_enable(__id)		\
> +	__imsic_eix_update((__id), 1, false, true)
> +#define __imsic_id_disable(__id)	\
> +	__imsic_eix_update((__id), 1, false, false)
> +
> +void imsic_id_set_target(unsigned int id, unsigned int target_cpu);
> +unsigned int imsic_id_get_target(unsigned int id);
> +
> +void imsic_ids_local_sync(void);
> +void imsic_ids_local_delivery(bool enable);
> +
> +#ifdef CONFIG_SMP
> +void imsic_ids_remote_sync(void);
> +#else
> +static inline void imsic_ids_remote_sync(void)
> +{
> +}
> +#endif
> +
> +int imsic_ids_alloc(unsigned int order);
> +void imsic_ids_free(unsigned int base_id, unsigned int order);
> +
> +int imsic_setup_state(struct fwnode_handle *fwnode);
> +
> +#endif
> diff --git a/include/linux/irqchip/riscv-imsic.h b/include/linux/irqchip/riscv-imsic.h
> new file mode 100644
> index 000000000000..1f6fc9a57218
> --- /dev/null
> +++ b/include/linux/irqchip/riscv-imsic.h
> @@ -0,0 +1,86 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> + * Copyright (C) 2022 Ventana Micro Systems Inc.
> + */
> +#ifndef __LINUX_IRQCHIP_RISCV_IMSIC_H
> +#define __LINUX_IRQCHIP_RISCV_IMSIC_H
> +
> +#include <linux/types.h>
> +#include <asm/csr.h>
> +
> +#define IMSIC_MMIO_PAGE_SHIFT		12
> +#define IMSIC_MMIO_PAGE_SZ		(1UL << IMSIC_MMIO_PAGE_SHIFT)
> +#define IMSIC_MMIO_PAGE_LE		0x00
> +#define IMSIC_MMIO_PAGE_BE		0x04
> +
> +#define IMSIC_MIN_ID			63
> +#define IMSIC_MAX_ID			2048
> +
> +#define IMSIC_EIDELIVERY		0x70
> +
> +#define IMSIC_EITHRESHOLD		0x72
> +
> +#define IMSIC_EIP0			0x80
> +#define IMSIC_EIP63			0xbf
> +#define IMSIC_EIPx_BITS			32
> +
> +#define IMSIC_EIE0			0xc0
> +#define IMSIC_EIE63			0xff
> +#define IMSIC_EIEx_BITS			32
> +
> +#define IMSIC_FIRST			IMSIC_EIDELIVERY
> +#define IMSIC_LAST			IMSIC_EIE63
> +
> +#define IMSIC_MMIO_SETIPNUM_LE		0x00
> +#define IMSIC_MMIO_SETIPNUM_BE		0x04
> +
> +struct imsic_local_config {
> +	phys_addr_t msi_pa;
> +	void __iomem *msi_va;
> +};
> +
> +struct imsic_global_config {
> +	/*
> +	 * MSI Target Address Scheme
> +	 *
> +	 * XLEN-1                                                12     0
> +	 * |                                                     |     |
> +	 * -------------------------------------------------------------
> +	 * |xxxxxx|Group Index|xxxxxxxxxxx|HART Index|Guest Index|  0  |
> +	 * -------------------------------------------------------------
> +	 */
> +
> +	/* Bits representing Guest index, HART index, and Group index */
> +	u32 guest_index_bits;
> +	u32 hart_index_bits;
> +	u32 group_index_bits;
> +	u32 group_index_shift;
> +
> +	/* Global base address matching all target MSI addresses */
> +	phys_addr_t base_addr;
> +
> +	/* Number of interrupt identities */
> +	u32 nr_ids;
> +
> +	/* Number of guest interrupt identities */
> +	u32 nr_guest_ids;
> +
> +	/* Per-CPU IMSIC addresses */
> +	struct imsic_local_config __percpu *local;
> +};
> +
> +#ifdef CONFIG_RISCV_IMSIC
> +
> +extern const struct imsic_global_config *imsic_get_global_config(void);
> +
> +#else
> +
> +static inline const struct imsic_global_config *imsic_get_global_config(void)
> +{
> +	return NULL;
> +}
> +
> +#endif
> +
> +#endif
> --
> 2.34.1
>
>
> _______________________________________________
> linux-riscv mailing list
> linux-riscv@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-riscv

Re: [PATCH v8 09/16] irqchip: Add RISC-V incoming MSI controller early driver

[Emil Renner Berthing]

Anup Patel wrote:
> The RISC-V advanced interrupt architecture (AIA) specification
> defines a new MSI controller called incoming message signalled
> interrupt controller (IMSIC) which manages MSI on per-HART (or
> per-CPU) basis. It also supports IPIs as software injected MSIs.
> (For more details refer https://github.com/riscv/riscv-aia)
>
> Let us add an early irqchip driver for RISC-V IMSIC which sets
> up the IMSIC state and provide IPIs.
>
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> ---
>  drivers/irqchip/Kconfig                 |   7 +-
>  drivers/irqchip/Makefile                |   1 +
>  drivers/irqchip/irq-riscv-imsic-early.c | 258 ++++++++++++
>  drivers/irqchip/irq-riscv-imsic-state.c | 523 ++++++++++++++++++++++++
>  drivers/irqchip/irq-riscv-imsic-state.h |  66 +++
>  include/linux/irqchip/riscv-imsic.h     |  86 ++++
>  6 files changed, 940 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/irqchip/irq-riscv-imsic-early.c
>  create mode 100644 drivers/irqchip/irq-riscv-imsic-state.c
>  create mode 100644 drivers/irqchip/irq-riscv-imsic-state.h
>  create mode 100644 include/linux/irqchip/riscv-imsic.h
>
> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> index f7149d0f3d45..ee99aacbefcc 100644
> --- a/drivers/irqchip/Kconfig
> +++ b/drivers/irqchip/Kconfig
> @@ -30,7 +30,6 @@ config ARM_GIC_V2M
>
>  config GIC_NON_BANKED
>  	bool
> -

Hi Anup,

This change looks like a mistake to me.

/Emil

>  config ARM_GIC_V3
>  	bool
>  	select IRQ_DOMAIN_HIERARCHY
> @@ -546,6 +545,12 @@ config SIFIVE_PLIC
>  	select IRQ_DOMAIN_HIERARCHY
>  	select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
>
> +config RISCV_IMSIC
> +	bool
> +	depends on RISCV
> +	select IRQ_DOMAIN_HIERARCHY
> +	select GENERIC_MSI_IRQ
> +
>  config EXYNOS_IRQ_COMBINER
>  	bool "Samsung Exynos IRQ combiner support" if COMPILE_TEST
>  	depends on (ARCH_EXYNOS && ARM) || COMPILE_TEST
> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index ffd945fe71aa..d714724387ce 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -95,6 +95,7 @@ obj-$(CONFIG_QCOM_MPM)			+= irq-qcom-mpm.o
>  obj-$(CONFIG_CSKY_MPINTC)		+= irq-csky-mpintc.o
>  obj-$(CONFIG_CSKY_APB_INTC)		+= irq-csky-apb-intc.o
>  obj-$(CONFIG_RISCV_INTC)		+= irq-riscv-intc.o
> +obj-$(CONFIG_RISCV_IMSIC)		+= irq-riscv-imsic-state.o irq-riscv-imsic-early.o
>  obj-$(CONFIG_SIFIVE_PLIC)		+= irq-sifive-plic.o
>  obj-$(CONFIG_IMX_IRQSTEER)		+= irq-imx-irqsteer.o
>  obj-$(CONFIG_IMX_INTMUX)		+= irq-imx-intmux.o
> diff --git a/drivers/irqchip/irq-riscv-imsic-early.c b/drivers/irqchip/irq-riscv-imsic-early.c
> new file mode 100644
> index 000000000000..1de89ce1ec2f
> --- /dev/null
> +++ b/drivers/irqchip/irq-riscv-imsic-early.c
> @@ -0,0 +1,258 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> + * Copyright (C) 2022 Ventana Micro Systems Inc.
> + */
> +
> +#define pr_fmt(fmt) "riscv-imsic: " fmt
> +#include <linux/cpu.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/irq.h>
> +#include <linux/irqchip.h>
> +#include <linux/irqchip/chained_irq.h>
> +#include <linux/module.h>
> +#include <linux/spinlock.h>
> +#include <linux/smp.h>
> +
> +#include "irq-riscv-imsic-state.h"
> +
> +/*
> + * The IMSIC driver uses 1 IPI for ID synchronization and
> + * arch/riscv/kernel/smp.c require 6 IPIs so we fix the
> + * total number of IPIs to 8.
> + */
> +#define IMSIC_NR_IPI				8
> +
> +static int imsic_parent_irq;
> +
> +#ifdef CONFIG_SMP
> +static irqreturn_t imsic_ids_sync_handler(int irq, void *data)
> +{
> +	imsic_ids_local_sync();
> +	return IRQ_HANDLED;
> +}
> +
> +void imsic_ids_remote_sync(void)
> +{
> +	struct cpumask amask;
> +
> +	/*
> +	 * We simply inject ID synchronization IPI to all target CPUs
> +	 * except current CPU. The ipi_send_mask() implementation of
> +	 * IPI mux will inject ID synchronization IPI only for CPUs
> +	 * that have enabled it so offline CPUs won't receive IPI.
> +	 * An offline CPU will unconditionally synchronize IDs through
> +	 * imsic_starting_cpu() when the CPU is brought up.
> +	 */
> +	cpumask_andnot(&amask, cpu_online_mask, cpumask_of(smp_processor_id()));
> +	__ipi_send_mask(imsic->ipi_lsync_desc, &amask);
> +}
> +
> +static void imsic_ipi_send(unsigned int cpu)
> +{
> +	struct imsic_local_config *local =
> +				per_cpu_ptr(imsic->global.local, cpu);
> +
> +	writel(imsic->ipi_id, local->msi_va);
> +}
> +
> +static void imsic_ipi_starting_cpu(void)
> +{
> +	/* Enable IPIs for current CPU. */
> +	__imsic_id_enable(imsic->ipi_id);
> +
> +	/* Enable virtual IPI used for IMSIC ID synchronization */
> +	enable_percpu_irq(imsic->ipi_virq, 0);
> +}
> +
> +static void imsic_ipi_dying_cpu(void)
> +{
> +	/*
> +	 * Disable virtual IPI used for IMSIC ID synchronization so
> +	 * that we don't receive ID synchronization requests.
> +	 */
> +	disable_percpu_irq(imsic->ipi_virq);
> +}
> +
> +static int __init imsic_ipi_domain_init(void)
> +{
> +	int virq;
> +
> +	/* Allocate interrupt identity for IPIs */
> +	virq = imsic_ids_alloc(get_count_order(1));
> +	if (virq < 0)
> +		return virq;
> +	imsic->ipi_id = virq;
> +
> +	/* Create IMSIC IPI multiplexing */
> +	virq = ipi_mux_create(IMSIC_NR_IPI, imsic_ipi_send);
> +	if (virq <= 0) {
> +		imsic_ids_free(imsic->ipi_id, get_count_order(1));
> +		return (virq < 0) ? virq : -ENOMEM;
> +	}
> +	imsic->ipi_virq = virq;
> +
> +	/* First vIRQ is used for IMSIC ID synchronization */
> +	virq = request_percpu_irq(imsic->ipi_virq, imsic_ids_sync_handler,
> +				  "riscv-imsic-lsync", imsic->global.local);
> +	if (virq) {
> +		imsic_ids_free(imsic->ipi_id, get_count_order(1));
> +		return virq;
> +	}
> +	irq_set_status_flags(imsic->ipi_virq, IRQ_HIDDEN);
> +	imsic->ipi_lsync_desc = irq_to_desc(imsic->ipi_virq);
> +
> +	/* Set vIRQ range */
> +	riscv_ipi_set_virq_range(imsic->ipi_virq + 1, IMSIC_NR_IPI - 1, true);
> +
> +	/* Announce that IMSIC is providing IPIs */
> +	pr_info("%pfwP: providing IPIs using interrupt %d\n",
> +		imsic->fwnode, imsic->ipi_id);
> +
> +	return 0;
> +}
> +#else
> +static void imsic_ipi_starting_cpu(void)
> +{
> +}
> +
> +static void imsic_ipi_dying_cpu(void)
> +{
> +}
> +
> +static int __init imsic_ipi_domain_init(void)
> +{
> +	/* Clear the IPI id because we are not using IPIs */
> +	imsic->ipi_id = 0;
> +	return 0;
> +}
> +#endif
> +
> +/*
> + * To handle an interrupt, we read the TOPEI CSR and write zero in one
> + * instruction. If TOPEI CSR is non-zero then we translate TOPEI.ID to
> + * Linux interrupt number and let Linux IRQ subsystem handle it.
> + */
> +static void imsic_handle_irq(struct irq_desc *desc)
> +{
> +	struct irq_chip *chip = irq_desc_get_chip(desc);
> +	irq_hw_number_t hwirq;
> +	int err;
> +
> +	chained_irq_enter(chip, desc);
> +
> +	while ((hwirq = csr_swap(CSR_TOPEI, 0))) {
> +		hwirq = hwirq >> TOPEI_ID_SHIFT;
> +
> +		if (hwirq == imsic->ipi_id) {
> +#ifdef CONFIG_SMP
> +			ipi_mux_process();
> +#endif
> +			continue;
> +		}
> +
> +		if (unlikely(!imsic->base_domain))
> +			continue;
> +
> +		err = generic_handle_domain_irq(imsic->base_domain, hwirq);
> +		if (unlikely(err))
> +			pr_warn_ratelimited(
> +				"hwirq %lu mapping not found\n", hwirq);
> +	}
> +
> +	chained_irq_exit(chip, desc);
> +}
> +
> +static int imsic_starting_cpu(unsigned int cpu)
> +{
> +	/* Enable per-CPU parent interrupt */
> +	enable_percpu_irq(imsic_parent_irq,
> +			  irq_get_trigger_type(imsic_parent_irq));
> +
> +	/* Setup IPIs */
> +	imsic_ipi_starting_cpu();
> +
> +	/*
> +	 * Interrupts identities might have been enabled/disabled while
> +	 * this CPU was not running so sync-up local enable/disable state.
> +	 */
> +	imsic_ids_local_sync();
> +
> +	/* Enable local interrupt delivery */
> +	imsic_ids_local_delivery(true);
> +
> +	return 0;
> +}
> +
> +static int imsic_dying_cpu(unsigned int cpu)
> +{
> +	/* Cleanup IPIs */
> +	imsic_ipi_dying_cpu();
> +
> +	return 0;
> +}
> +
> +static int __init imsic_early_probe(struct fwnode_handle *fwnode)
> +{
> +	int rc;
> +	struct irq_domain *domain;
> +
> +	/* Setup IMSIC state */
> +	rc = imsic_setup_state(fwnode);
> +	if (rc) {
> +		pr_err("%pfwP: failed to setup state (error %d)\n",
> +			fwnode, rc);
> +		return rc;
> +	}
> +
> +	/* Find parent domain and register chained handler */
> +	domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
> +					  DOMAIN_BUS_ANY);
> +	if (!domain) {
> +		pr_err("%pfwP: Failed to find INTC domain\n", fwnode);
> +		return -ENOENT;
> +	}
> +	imsic_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT);
> +	if (!imsic_parent_irq) {
> +		pr_err("%pfwP: Failed to create INTC mapping\n", fwnode);
> +		return -ENOENT;
> +	}
> +	irq_set_chained_handler(imsic_parent_irq, imsic_handle_irq);
> +
> +	/* Initialize IPI domain */
> +	rc = imsic_ipi_domain_init();
> +	if (rc) {
> +		pr_err("%pfwP: Failed to initialize IPI domain\n", fwnode);
> +		return rc;
> +	}
> +
> +	/*
> +	 * Setup cpuhp state (must be done after setting imsic_parent_irq)
> +	 *
> +	 * Don't disable per-CPU IMSIC file when CPU goes offline
> +	 * because this affects IPI and the masking/unmasking of
> +	 * virtual IPIs is done via generic IPI-Mux
> +	 */
> +	cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
> +			  "irqchip/riscv/imsic:starting",
> +			  imsic_starting_cpu, imsic_dying_cpu);
> +
> +	return 0;
> +}
> +
> +static int __init imsic_early_dt_init(struct device_node *node,
> +				      struct device_node *parent)
> +{
> +	int rc;
> +
> +	/* Do early setup of IMSIC state and IPIs */
> +	rc = imsic_early_probe(&node->fwnode);
> +	if (rc)
> +		return rc;
> +
> +	/* Ensure that OF platform device gets probed */
> +	of_node_clear_flag(node, OF_POPULATED);
> +	return 0;
> +}
> +IRQCHIP_DECLARE(riscv_imsic, "riscv,imsics", imsic_early_dt_init);
> diff --git a/drivers/irqchip/irq-riscv-imsic-state.c b/drivers/irqchip/irq-riscv-imsic-state.c
> new file mode 100644
> index 000000000000..412b5b919dcc
> --- /dev/null
> +++ b/drivers/irqchip/irq-riscv-imsic-state.c
> @@ -0,0 +1,523 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> + * Copyright (C) 2022 Ventana Micro Systems Inc.
> + */
> +
> +#define pr_fmt(fmt) "riscv-imsic: " fmt
> +#include <linux/bitmap.h>
> +#include <linux/module.h>
> +#include <linux/of_address.h>
> +#include <linux/spinlock.h>
> +#include <linux/smp.h>
> +#include <asm/hwcap.h>
> +
> +#include "irq-riscv-imsic-state.h"
> +
> +#define IMSIC_DISABLE_EIDELIVERY		0
> +#define IMSIC_ENABLE_EIDELIVERY			1
> +#define IMSIC_DISABLE_EITHRESHOLD		1
> +#define IMSIC_ENABLE_EITHRESHOLD		0
> +
> +#define imsic_csr_write(__c, __v)		\
> +do {						\
> +	csr_write(CSR_ISELECT, __c);		\
> +	csr_write(CSR_IREG, __v);		\
> +} while (0)
> +
> +#define imsic_csr_read(__c)			\
> +({						\
> +	unsigned long __v;			\
> +	csr_write(CSR_ISELECT, __c);		\
> +	__v = csr_read(CSR_IREG);		\
> +	__v;					\
> +})
> +
> +#define imsic_csr_set(__c, __v)			\
> +do {						\
> +	csr_write(CSR_ISELECT, __c);		\
> +	csr_set(CSR_IREG, __v);			\
> +} while (0)
> +
> +#define imsic_csr_clear(__c, __v)		\
> +do {						\
> +	csr_write(CSR_ISELECT, __c);		\
> +	csr_clear(CSR_IREG, __v);		\
> +} while (0)
> +
> +struct imsic_priv *imsic;
> +
> +const struct imsic_global_config *imsic_get_global_config(void)
> +{
> +	return (imsic) ? &imsic->global : NULL;
> +}
> +EXPORT_SYMBOL_GPL(imsic_get_global_config);
> +
> +void __imsic_eix_update(unsigned long base_id,
> +			unsigned long num_id, bool pend, bool val)
> +{
> +	unsigned long i, isel, ireg;
> +	unsigned long id = base_id, last_id = base_id + num_id;
> +
> +	while (id < last_id) {
> +		isel = id / BITS_PER_LONG;
> +		isel *= BITS_PER_LONG / IMSIC_EIPx_BITS;
> +		isel += (pend) ? IMSIC_EIP0 : IMSIC_EIE0;
> +
> +		ireg = 0;
> +		for (i = id & (__riscv_xlen - 1);
> +		     (id < last_id) && (i < __riscv_xlen); i++) {
> +			ireg |= BIT(i);
> +			id++;
> +		}
> +
> +		/*
> +		 * The IMSIC EIEx and EIPx registers are indirectly
> +		 * accessed via using ISELECT and IREG CSRs so we
> +		 * need to access these CSRs without getting preempted.
> +		 *
> +		 * All existing users of this function call this
> +		 * function with local IRQs disabled so we don't
> +		 * need to do anything special here.
> +		 */
> +		if (val)
> +			imsic_csr_set(isel, ireg);
> +		else
> +			imsic_csr_clear(isel, ireg);
> +	}
> +}
> +
> +void imsic_id_set_target(unsigned int id, unsigned int target_cpu)
> +{
> +	unsigned long flags;
> +
> +	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> +	imsic->ids_target_cpu[id] = target_cpu;
> +	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> +}
> +
> +unsigned int imsic_id_get_target(unsigned int id)
> +{
> +	unsigned int ret;
> +	unsigned long flags;
> +
> +	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> +	ret = imsic->ids_target_cpu[id];
> +	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> +
> +	return ret;
> +}
> +
> +void imsic_ids_local_sync(void)
> +{
> +	int i;
> +	unsigned long flags;
> +
> +	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> +	for (i = 1; i <= imsic->global.nr_ids; i++) {
> +		if (imsic->ipi_id == i)
> +			continue;
> +
> +		if (test_bit(i, imsic->ids_enabled_bimap))
> +			__imsic_id_enable(i);
> +		else
> +			__imsic_id_disable(i);
> +	}
> +	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> +}
> +
> +void imsic_ids_local_delivery(bool enable)
> +{
> +	if (enable) {
> +		imsic_csr_write(IMSIC_EITHRESHOLD, IMSIC_ENABLE_EITHRESHOLD);
> +		imsic_csr_write(IMSIC_EIDELIVERY, IMSIC_ENABLE_EIDELIVERY);
> +	} else {
> +		imsic_csr_write(IMSIC_EIDELIVERY, IMSIC_DISABLE_EIDELIVERY);
> +		imsic_csr_write(IMSIC_EITHRESHOLD, IMSIC_DISABLE_EITHRESHOLD);
> +	}
> +}
> +
> +int imsic_ids_alloc(unsigned int order)
> +{
> +	int ret;
> +	unsigned long flags;
> +
> +	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> +	ret = bitmap_find_free_region(imsic->ids_used_bimap,
> +				      imsic->global.nr_ids + 1, order);
> +	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> +
> +	return ret;
> +}
> +
> +void imsic_ids_free(unsigned int base_id, unsigned int order)
> +{
> +	unsigned long flags;
> +
> +	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> +	bitmap_release_region(imsic->ids_used_bimap, base_id, order);
> +	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> +}
> +
> +static int __init imsic_ids_init(void)
> +{
> +	int i;
> +	struct imsic_global_config *global = &imsic->global;
> +
> +	raw_spin_lock_init(&imsic->ids_lock);
> +
> +	/* Allocate used bitmap */
> +	imsic->ids_used_bimap = bitmap_zalloc(global->nr_ids + 1, GFP_KERNEL);
> +	if (!imsic->ids_used_bimap)
> +		return -ENOMEM;
> +
> +	/* Allocate enabled bitmap */
> +	imsic->ids_enabled_bimap = bitmap_zalloc(global->nr_ids + 1,
> +						GFP_KERNEL);
> +	if (!imsic->ids_enabled_bimap) {
> +		kfree(imsic->ids_used_bimap);
> +		return -ENOMEM;
> +	}
> +
> +	/* Allocate target CPU array */
> +	imsic->ids_target_cpu = kcalloc(global->nr_ids + 1,
> +				       sizeof(unsigned int), GFP_KERNEL);
> +	if (!imsic->ids_target_cpu) {
> +		bitmap_free(imsic->ids_enabled_bimap);
> +		bitmap_free(imsic->ids_used_bimap);
> +		return -ENOMEM;
> +	}
> +	for (i = 0; i <= global->nr_ids; i++)
> +		imsic->ids_target_cpu[i] = UINT_MAX;
> +
> +	/* Reserve ID#0 because it is special and never implemented */
> +	bitmap_set(imsic->ids_used_bimap, 0, 1);
> +
> +	return 0;
> +}
> +
> +static void __init imsic_ids_cleanup(void)
> +{
> +	kfree(imsic->ids_target_cpu);
> +	bitmap_free(imsic->ids_enabled_bimap);
> +	bitmap_free(imsic->ids_used_bimap);
> +}
> +
> +static int __init imsic_get_parent_hartid(struct fwnode_handle *fwnode,
> +					  u32 index, unsigned long *hartid)
> +{
> +	int rc;
> +	struct fwnode_reference_args parent;
> +
> +	rc = fwnode_property_get_reference_args(fwnode,
> +			"interrupts-extended", "#interrupt-cells",
> +			0, index, &parent);
> +	if (rc)
> +		return rc;
> +
> +	/*
> +	 * Skip interrupts other than external interrupts for
> +	 * current privilege level.
> +	 */
> +	if (parent.args[0] != RV_IRQ_EXT)
> +		return -EINVAL;
> +
> +	return riscv_get_intc_hartid(parent.fwnode, hartid);
> +}
> +
> +static int __init imsic_get_mmio_resource(struct fwnode_handle *fwnode,
> +					  u32 index, struct resource *res)
> +{
> +	/*
> +	 * Currently, only OF fwnode is support so extend this function
> +	 * for other types of fwnode for ACPI support.
> +	 */
> +	if (!is_of_node(fwnode))
> +		return -EINVAL;
> +	return of_address_to_resource(to_of_node(fwnode), index, res);
> +}
> +
> +int __init imsic_setup_state(struct fwnode_handle *fwnode)
> +{
> +	int rc, cpu;
> +	phys_addr_t base_addr;
> +	void __iomem **mmios_va = NULL;
> +	struct resource res, *mmios = NULL;
> +	struct imsic_local_config *local;
> +	struct imsic_global_config *global;
> +	unsigned long reloff, hartid;
> +	u32 i, j, index, nr_parent_irqs, nr_handlers = 0, num_mmios = 0;
> +
> +	/*
> +	 * Only one IMSIC instance allowed in a platform for clean
> +	 * implementation of SMP IRQ affinity and per-CPU IPIs.
> +	 *
> +	 * This means on a multi-socket (or multi-die) platform we
> +	 * will have multiple MMIO regions for one IMSIC instance.
> +	 */
> +	if (imsic) {
> +		pr_err("%pfwP: already initialized hence ignoring\n",
> +			fwnode);
> +		return -EALREADY;
> +	}
> +
> +	if (!riscv_isa_extension_available(NULL, SxAIA)) {
> +		pr_err("%pfwP: AIA support not available\n", fwnode);
> +		return -ENODEV;
> +	}
> +
> +	imsic = kzalloc(sizeof(*imsic), GFP_KERNEL);
> +	if (!imsic)
> +		return -ENOMEM;
> +	imsic->fwnode = fwnode;
> +	global = &imsic->global;
> +
> +	global->local = alloc_percpu(typeof(*(global->local)));
> +	if (!global->local) {
> +		rc = -ENOMEM;
> +		goto out_free_priv;
> +	}
> +
> +	/* Find number of parent interrupts */
> +	nr_parent_irqs = 0;
> +	while (!imsic_get_parent_hartid(fwnode, nr_parent_irqs, &hartid))
> +		nr_parent_irqs++;
> +	if (!nr_parent_irqs) {
> +		pr_err("%pfwP: no parent irqs available\n", fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +
> +	/* Find number of guest index bits in MSI address */
> +	rc = fwnode_property_read_u32_array(fwnode, "riscv,guest-index-bits",
> +					    &global->guest_index_bits, 1);
> +	if (rc)
> +		global->guest_index_bits = 0;
> +	i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT;
> +	if (i < global->guest_index_bits) {
> +		pr_err("%pfwP: guest index bits too big\n", fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +
> +	/* Find number of HART index bits */
> +	rc = fwnode_property_read_u32_array(fwnode, "riscv,hart-index-bits",
> +					    &global->hart_index_bits, 1);
> +	if (rc) {
> +		/* Assume default value */
> +		global->hart_index_bits = __fls(nr_parent_irqs);
> +		if (BIT(global->hart_index_bits) < nr_parent_irqs)
> +			global->hart_index_bits++;
> +	}
> +	i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT - global->guest_index_bits;
> +	if (i < global->hart_index_bits) {
> +		pr_err("%pfwP: HART index bits too big\n", fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +
> +	/* Find number of group index bits */
> +	rc = fwnode_property_read_u32_array(fwnode, "riscv,group-index-bits",
> +					    &global->group_index_bits, 1);
> +	if (rc)
> +		global->group_index_bits = 0;
> +	i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT -
> +	    global->guest_index_bits - global->hart_index_bits;
> +	if (i < global->group_index_bits) {
> +		pr_err("%pfwP: group index bits too big\n", fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +
> +	/*
> +	 * Find first bit position of group index.
> +	 * If not specified assumed the default APLIC-IMSIC configuration.
> +	 */
> +	rc = fwnode_property_read_u32_array(fwnode, "riscv,group-index-shift",
> +					    &global->group_index_shift, 1);
> +	if (rc)
> +		global->group_index_shift = IMSIC_MMIO_PAGE_SHIFT * 2;
> +	i = global->group_index_bits + global->group_index_shift - 1;
> +	if (i >= BITS_PER_LONG) {
> +		pr_err("%pfwP: group index shift too big\n", fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +
> +	/* Find number of interrupt identities */
> +	rc = fwnode_property_read_u32_array(fwnode, "riscv,num-ids",
> +					    &global->nr_ids, 1);
> +	if (rc) {
> +		pr_err("%pfwP: number of interrupt identities not found\n",
> +			fwnode);
> +		goto out_free_local;
> +	}
> +	if ((global->nr_ids < IMSIC_MIN_ID) ||
> +	    (global->nr_ids >= IMSIC_MAX_ID) ||
> +	    ((global->nr_ids & IMSIC_MIN_ID) != IMSIC_MIN_ID)) {
> +		pr_err("%pfwP: invalid number of interrupt identities\n",
> +			fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +
> +	/* Find number of guest interrupt identities */
> +	if (fwnode_property_read_u32_array(fwnode, "riscv,num-guest-ids",
> +					   &global->nr_guest_ids, 1))
> +		global->nr_guest_ids = global->nr_ids;
> +	if ((global->nr_guest_ids < IMSIC_MIN_ID) ||
> +	    (global->nr_guest_ids >= IMSIC_MAX_ID) ||
> +	    ((global->nr_guest_ids & IMSIC_MIN_ID) != IMSIC_MIN_ID)) {
> +		pr_err("%pfwP: invalid number of guest interrupt identities\n",
> +			fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +
> +	/* Compute base address */
> +	rc = imsic_get_mmio_resource(fwnode, 0, &res);
> +	if (rc) {
> +		pr_err("%pfwP: first MMIO resource not found\n", fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +	global->base_addr = res.start;
> +	global->base_addr &= ~(BIT(global->guest_index_bits +
> +				   global->hart_index_bits +
> +				   IMSIC_MMIO_PAGE_SHIFT) - 1);
> +	global->base_addr &= ~((BIT(global->group_index_bits) - 1) <<
> +			       global->group_index_shift);
> +
> +	/* Find number of MMIO register sets */
> +	while (!imsic_get_mmio_resource(fwnode, num_mmios, &res))
> +		num_mmios++;
> +
> +	/* Allocate MMIO resource array */
> +	mmios = kcalloc(num_mmios, sizeof(*mmios), GFP_KERNEL);
> +	if (!mmios) {
> +		rc = -ENOMEM;
> +		goto out_free_local;
> +	}
> +
> +	/* Allocate MMIO virtual address array */
> +	mmios_va = kcalloc(num_mmios, sizeof(*mmios_va), GFP_KERNEL);
> +	if (!mmios_va) {
> +		rc = -ENOMEM;
> +		goto out_iounmap;
> +	}
> +
> +	/* Parse and map MMIO register sets */
> +	for (i = 0; i < num_mmios; i++) {
> +		rc = imsic_get_mmio_resource(fwnode, i, &mmios[i]);
> +		if (rc) {
> +			pr_err("%pfwP: unable to parse MMIO regset %d\n",
> +				fwnode, i);
> +			goto out_iounmap;
> +		}
> +
> +		base_addr = mmios[i].start;
> +		base_addr &= ~(BIT(global->guest_index_bits +
> +				   global->hart_index_bits +
> +				   IMSIC_MMIO_PAGE_SHIFT) - 1);
> +		base_addr &= ~((BIT(global->group_index_bits) - 1) <<
> +			       global->group_index_shift);
> +		if (base_addr != global->base_addr) {
> +			rc = -EINVAL;
> +			pr_err("%pfwP: address mismatch for regset %d\n",
> +				fwnode, i);
> +			goto out_iounmap;
> +		}
> +
> +		mmios_va[i] = ioremap(mmios[i].start, resource_size(&mmios[i]));
> +		if (!mmios_va[i]) {
> +			rc = -EIO;
> +			pr_err("%pfwP: unable to map MMIO regset %d\n",
> +				fwnode, i);
> +			goto out_iounmap;
> +		}
> +	}
> +
> +	/* Initialize interrupt identity management */
> +	rc = imsic_ids_init();
> +	if (rc) {
> +		pr_err("%pfwP: failed to initialize interrupt management\n",
> +		       fwnode);
> +		goto out_iounmap;
> +	}
> +
> +	/* Configure handlers for target CPUs */
> +	for (i = 0; i < nr_parent_irqs; i++) {
> +		rc = imsic_get_parent_hartid(fwnode, i, &hartid);
> +		if (rc) {
> +			pr_warn("%pfwP: hart ID for parent irq%d not found\n",
> +				fwnode, i);
> +			continue;
> +		}
> +
> +		cpu = riscv_hartid_to_cpuid(hartid);
> +		if (cpu < 0) {
> +			pr_warn("%pfwP: invalid cpuid for parent irq%d\n",
> +				fwnode, i);
> +			continue;
> +		}
> +
> +		/* Find MMIO location of MSI page */
> +		index = num_mmios;
> +		reloff = i * BIT(global->guest_index_bits) *
> +			 IMSIC_MMIO_PAGE_SZ;
> +		for (j = 0; num_mmios; j++) {
> +			if (reloff < resource_size(&mmios[j])) {
> +				index = j;
> +				break;
> +			}
> +
> +			/*
> +			 * MMIO region size may not be aligned to
> +			 * BIT(global->guest_index_bits) * IMSIC_MMIO_PAGE_SZ
> +			 * if holes are present.
> +			 */
> +			reloff -= ALIGN(resource_size(&mmios[j]),
> +			BIT(global->guest_index_bits) * IMSIC_MMIO_PAGE_SZ);
> +		}
> +		if (index >= num_mmios) {
> +			pr_warn("%pfwP: MMIO not found for parent irq%d\n",
> +				fwnode, i);
> +			continue;
> +		}
> +
> +		local = per_cpu_ptr(global->local, cpu);
> +		local->msi_pa = mmios[index].start + reloff;
> +		local->msi_va = mmios_va[index] + reloff;
> +
> +		nr_handlers++;
> +	}
> +
> +	/* If no CPU handlers found then can't take interrupts */
> +	if (!nr_handlers) {
> +		pr_err("%pfwP: No CPU handlers found\n", fwnode);
> +		rc = -ENODEV;
> +		goto out_ids_cleanup;
> +	}
> +
> +	/* We don't need MMIO arrays anymore so let's free-up */
> +	kfree(mmios_va);
> +	kfree(mmios);
> +
> +	return 0;
> +
> +out_ids_cleanup:
> +	imsic_ids_cleanup();
> +out_iounmap:
> +	for (i = 0; i < num_mmios; i++) {
> +		if (mmios_va[i])
> +			iounmap(mmios_va[i]);
> +	}
> +	kfree(mmios_va);
> +	kfree(mmios);
> +out_free_local:
> +	free_percpu(imsic->global.local);
> +out_free_priv:
> +	kfree(imsic);
> +	imsic = NULL;
> +	return rc;
> +}
> diff --git a/drivers/irqchip/irq-riscv-imsic-state.h b/drivers/irqchip/irq-riscv-imsic-state.h
> new file mode 100644
> index 000000000000..3170018949a8
> --- /dev/null
> +++ b/drivers/irqchip/irq-riscv-imsic-state.h
> @@ -0,0 +1,66 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> + * Copyright (C) 2022 Ventana Micro Systems Inc.
> + */
> +
> +#ifndef _IRQ_RISCV_IMSIC_STATE_H
> +#define _IRQ_RISCV_IMSIC_STATE_H
> +
> +#include <linux/irqchip/riscv-imsic.h>
> +#include <linux/irqdomain.h>
> +#include <linux/fwnode.h>
> +
> +struct imsic_priv {
> +	/* Device details */
> +	struct fwnode_handle *fwnode;
> +
> +	/* Global configuration common for all HARTs */
> +	struct imsic_global_config global;
> +
> +	/* Global state of interrupt identities */
> +	raw_spinlock_t ids_lock;
> +	unsigned long *ids_used_bimap;
> +	unsigned long *ids_enabled_bimap;
> +	unsigned int *ids_target_cpu;
> +
> +	/* IPI interrupt identity and synchronization */
> +	u32 ipi_id;
> +	int ipi_virq;
> +	struct irq_desc *ipi_lsync_desc;
> +
> +	/* IRQ domains (created by platform driver) */
> +	struct irq_domain *base_domain;
> +	struct irq_domain *plat_domain;
> +};
> +
> +extern struct imsic_priv *imsic;
> +
> +void __imsic_eix_update(unsigned long base_id,
> +			unsigned long num_id, bool pend, bool val);
> +
> +#define __imsic_id_enable(__id)		\
> +	__imsic_eix_update((__id), 1, false, true)
> +#define __imsic_id_disable(__id)	\
> +	__imsic_eix_update((__id), 1, false, false)
> +
> +void imsic_id_set_target(unsigned int id, unsigned int target_cpu);
> +unsigned int imsic_id_get_target(unsigned int id);
> +
> +void imsic_ids_local_sync(void);
> +void imsic_ids_local_delivery(bool enable);
> +
> +#ifdef CONFIG_SMP
> +void imsic_ids_remote_sync(void);
> +#else
> +static inline void imsic_ids_remote_sync(void)
> +{
> +}
> +#endif
> +
> +int imsic_ids_alloc(unsigned int order);
> +void imsic_ids_free(unsigned int base_id, unsigned int order);
> +
> +int imsic_setup_state(struct fwnode_handle *fwnode);
> +
> +#endif
> diff --git a/include/linux/irqchip/riscv-imsic.h b/include/linux/irqchip/riscv-imsic.h
> new file mode 100644
> index 000000000000..1f6fc9a57218
> --- /dev/null
> +++ b/include/linux/irqchip/riscv-imsic.h
> @@ -0,0 +1,86 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> + * Copyright (C) 2022 Ventana Micro Systems Inc.
> + */
> +#ifndef __LINUX_IRQCHIP_RISCV_IMSIC_H
> +#define __LINUX_IRQCHIP_RISCV_IMSIC_H
> +
> +#include <linux/types.h>
> +#include <asm/csr.h>
> +
> +#define IMSIC_MMIO_PAGE_SHIFT		12
> +#define IMSIC_MMIO_PAGE_SZ		(1UL << IMSIC_MMIO_PAGE_SHIFT)
> +#define IMSIC_MMIO_PAGE_LE		0x00
> +#define IMSIC_MMIO_PAGE_BE		0x04
> +
> +#define IMSIC_MIN_ID			63
> +#define IMSIC_MAX_ID			2048
> +
> +#define IMSIC_EIDELIVERY		0x70
> +
> +#define IMSIC_EITHRESHOLD		0x72
> +
> +#define IMSIC_EIP0			0x80
> +#define IMSIC_EIP63			0xbf
> +#define IMSIC_EIPx_BITS			32
> +
> +#define IMSIC_EIE0			0xc0
> +#define IMSIC_EIE63			0xff
> +#define IMSIC_EIEx_BITS			32
> +
> +#define IMSIC_FIRST			IMSIC_EIDELIVERY
> +#define IMSIC_LAST			IMSIC_EIE63
> +
> +#define IMSIC_MMIO_SETIPNUM_LE		0x00
> +#define IMSIC_MMIO_SETIPNUM_BE		0x04
> +
> +struct imsic_local_config {
> +	phys_addr_t msi_pa;
> +	void __iomem *msi_va;
> +};
> +
> +struct imsic_global_config {
> +	/*
> +	 * MSI Target Address Scheme
> +	 *
> +	 * XLEN-1                                                12     0
> +	 * |                                                     |     |
> +	 * -------------------------------------------------------------
> +	 * |xxxxxx|Group Index|xxxxxxxxxxx|HART Index|Guest Index|  0  |
> +	 * -------------------------------------------------------------
> +	 */
> +
> +	/* Bits representing Guest index, HART index, and Group index */
> +	u32 guest_index_bits;
> +	u32 hart_index_bits;
> +	u32 group_index_bits;
> +	u32 group_index_shift;
> +
> +	/* Global base address matching all target MSI addresses */
> +	phys_addr_t base_addr;
> +
> +	/* Number of interrupt identities */
> +	u32 nr_ids;
> +
> +	/* Number of guest interrupt identities */
> +	u32 nr_guest_ids;
> +
> +	/* Per-CPU IMSIC addresses */
> +	struct imsic_local_config __percpu *local;
> +};
> +
> +#ifdef CONFIG_RISCV_IMSIC
> +
> +extern const struct imsic_global_config *imsic_get_global_config(void);
> +
> +#else
> +
> +static inline const struct imsic_global_config *imsic_get_global_config(void)
> +{
> +	return NULL;
> +}
> +
> +#endif
> +
> +#endif
> --
> 2.34.1
>
>
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Re: [PATCH v8 09/16] irqchip: Add RISC-V incoming MSI controller early driver

[Anup Patel]

On Wed, Sep 13, 2023 at 4:03 PM Emil Renner Berthing
<emil.renner.berthing@canonical.com> wrote:
>
> Anup Patel wrote:
> > The RISC-V advanced interrupt architecture (AIA) specification
> > defines a new MSI controller called incoming message signalled
> > interrupt controller (IMSIC) which manages MSI on per-HART (or
> > per-CPU) basis. It also supports IPIs as software injected MSIs.
> > (For more details refer https://github.com/riscv/riscv-aia)
> >
> > Let us add an early irqchip driver for RISC-V IMSIC which sets
> > up the IMSIC state and provide IPIs.
> >
> > Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> > ---
> >  drivers/irqchip/Kconfig                 |   7 +-
> >  drivers/irqchip/Makefile                |   1 +
> >  drivers/irqchip/irq-riscv-imsic-early.c | 258 ++++++++++++
> >  drivers/irqchip/irq-riscv-imsic-state.c | 523 ++++++++++++++++++++++++
> >  drivers/irqchip/irq-riscv-imsic-state.h |  66 +++
> >  include/linux/irqchip/riscv-imsic.h     |  86 ++++
> >  6 files changed, 940 insertions(+), 1 deletion(-)
> >  create mode 100644 drivers/irqchip/irq-riscv-imsic-early.c
> >  create mode 100644 drivers/irqchip/irq-riscv-imsic-state.c
> >  create mode 100644 drivers/irqchip/irq-riscv-imsic-state.h
> >  create mode 100644 include/linux/irqchip/riscv-imsic.h
> >
> > diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> > index f7149d0f3d45..ee99aacbefcc 100644
> > --- a/drivers/irqchip/Kconfig
> > +++ b/drivers/irqchip/Kconfig
> > @@ -30,7 +30,6 @@ config ARM_GIC_V2M
> >
> >  config GIC_NON_BANKED
> >       bool
> > -
>
> Hi Anup,
>
> This change looks like a mistake to me.

Ahh, yes. This change creeped in accidentally.

I will remove this change in the next revision.

Regards,
Anup

>
> /Emil
>
> >  config ARM_GIC_V3
> >       bool
> >       select IRQ_DOMAIN_HIERARCHY
> > @@ -546,6 +545,12 @@ config SIFIVE_PLIC
> >       select IRQ_DOMAIN_HIERARCHY
> >       select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
> >
> > +config RISCV_IMSIC
> > +     bool
> > +     depends on RISCV
> > +     select IRQ_DOMAIN_HIERARCHY
> > +     select GENERIC_MSI_IRQ
> > +
> >  config EXYNOS_IRQ_COMBINER
> >       bool "Samsung Exynos IRQ combiner support" if COMPILE_TEST
> >       depends on (ARCH_EXYNOS && ARM) || COMPILE_TEST
> > diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> > index ffd945fe71aa..d714724387ce 100644
> > --- a/drivers/irqchip/Makefile
> > +++ b/drivers/irqchip/Makefile
> > @@ -95,6 +95,7 @@ obj-$(CONFIG_QCOM_MPM)                      += irq-qcom-mpm.o
> >  obj-$(CONFIG_CSKY_MPINTC)            += irq-csky-mpintc.o
> >  obj-$(CONFIG_CSKY_APB_INTC)          += irq-csky-apb-intc.o
> >  obj-$(CONFIG_RISCV_INTC)             += irq-riscv-intc.o
> > +obj-$(CONFIG_RISCV_IMSIC)            += irq-riscv-imsic-state.o irq-riscv-imsic-early.o
> >  obj-$(CONFIG_SIFIVE_PLIC)            += irq-sifive-plic.o
> >  obj-$(CONFIG_IMX_IRQSTEER)           += irq-imx-irqsteer.o
> >  obj-$(CONFIG_IMX_INTMUX)             += irq-imx-intmux.o
> > diff --git a/drivers/irqchip/irq-riscv-imsic-early.c b/drivers/irqchip/irq-riscv-imsic-early.c
> > new file mode 100644
> > index 000000000000..1de89ce1ec2f
> > --- /dev/null
> > +++ b/drivers/irqchip/irq-riscv-imsic-early.c
> > @@ -0,0 +1,258 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +
> > +#define pr_fmt(fmt) "riscv-imsic: " fmt
> > +#include <linux/cpu.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/io.h>
> > +#include <linux/irq.h>
> > +#include <linux/irqchip.h>
> > +#include <linux/irqchip/chained_irq.h>
> > +#include <linux/module.h>
> > +#include <linux/spinlock.h>
> > +#include <linux/smp.h>
> > +
> > +#include "irq-riscv-imsic-state.h"
> > +
> > +/*
> > + * The IMSIC driver uses 1 IPI for ID synchronization and
> > + * arch/riscv/kernel/smp.c require 6 IPIs so we fix the
> > + * total number of IPIs to 8.
> > + */
> > +#define IMSIC_NR_IPI                         8
> > +
> > +static int imsic_parent_irq;
> > +
> > +#ifdef CONFIG_SMP
> > +static irqreturn_t imsic_ids_sync_handler(int irq, void *data)
> > +{
> > +     imsic_ids_local_sync();
> > +     return IRQ_HANDLED;
> > +}
> > +
> > +void imsic_ids_remote_sync(void)
> > +{
> > +     struct cpumask amask;
> > +
> > +     /*
> > +      * We simply inject ID synchronization IPI to all target CPUs
> > +      * except current CPU. The ipi_send_mask() implementation of
> > +      * IPI mux will inject ID synchronization IPI only for CPUs
> > +      * that have enabled it so offline CPUs won't receive IPI.
> > +      * An offline CPU will unconditionally synchronize IDs through
> > +      * imsic_starting_cpu() when the CPU is brought up.
> > +      */
> > +     cpumask_andnot(&amask, cpu_online_mask, cpumask_of(smp_processor_id()));
> > +     __ipi_send_mask(imsic->ipi_lsync_desc, &amask);
> > +}
> > +
> > +static void imsic_ipi_send(unsigned int cpu)
> > +{
> > +     struct imsic_local_config *local =
> > +                             per_cpu_ptr(imsic->global.local, cpu);
> > +
> > +     writel(imsic->ipi_id, local->msi_va);
> > +}
> > +
> > +static void imsic_ipi_starting_cpu(void)
> > +{
> > +     /* Enable IPIs for current CPU. */
> > +     __imsic_id_enable(imsic->ipi_id);
> > +
> > +     /* Enable virtual IPI used for IMSIC ID synchronization */
> > +     enable_percpu_irq(imsic->ipi_virq, 0);
> > +}
> > +
> > +static void imsic_ipi_dying_cpu(void)
> > +{
> > +     /*
> > +      * Disable virtual IPI used for IMSIC ID synchronization so
> > +      * that we don't receive ID synchronization requests.
> > +      */
> > +     disable_percpu_irq(imsic->ipi_virq);
> > +}
> > +
> > +static int __init imsic_ipi_domain_init(void)
> > +{
> > +     int virq;
> > +
> > +     /* Allocate interrupt identity for IPIs */
> > +     virq = imsic_ids_alloc(get_count_order(1));
> > +     if (virq < 0)
> > +             return virq;
> > +     imsic->ipi_id = virq;
> > +
> > +     /* Create IMSIC IPI multiplexing */
> > +     virq = ipi_mux_create(IMSIC_NR_IPI, imsic_ipi_send);
> > +     if (virq <= 0) {
> > +             imsic_ids_free(imsic->ipi_id, get_count_order(1));
> > +             return (virq < 0) ? virq : -ENOMEM;
> > +     }
> > +     imsic->ipi_virq = virq;
> > +
> > +     /* First vIRQ is used for IMSIC ID synchronization */
> > +     virq = request_percpu_irq(imsic->ipi_virq, imsic_ids_sync_handler,
> > +                               "riscv-imsic-lsync", imsic->global.local);
> > +     if (virq) {
> > +             imsic_ids_free(imsic->ipi_id, get_count_order(1));
> > +             return virq;
> > +     }
> > +     irq_set_status_flags(imsic->ipi_virq, IRQ_HIDDEN);
> > +     imsic->ipi_lsync_desc = irq_to_desc(imsic->ipi_virq);
> > +
> > +     /* Set vIRQ range */
> > +     riscv_ipi_set_virq_range(imsic->ipi_virq + 1, IMSIC_NR_IPI - 1, true);
> > +
> > +     /* Announce that IMSIC is providing IPIs */
> > +     pr_info("%pfwP: providing IPIs using interrupt %d\n",
> > +             imsic->fwnode, imsic->ipi_id);
> > +
> > +     return 0;
> > +}
> > +#else
> > +static void imsic_ipi_starting_cpu(void)
> > +{
> > +}
> > +
> > +static void imsic_ipi_dying_cpu(void)
> > +{
> > +}
> > +
> > +static int __init imsic_ipi_domain_init(void)
> > +{
> > +     /* Clear the IPI id because we are not using IPIs */
> > +     imsic->ipi_id = 0;
> > +     return 0;
> > +}
> > +#endif
> > +
> > +/*
> > + * To handle an interrupt, we read the TOPEI CSR and write zero in one
> > + * instruction. If TOPEI CSR is non-zero then we translate TOPEI.ID to
> > + * Linux interrupt number and let Linux IRQ subsystem handle it.
> > + */
> > +static void imsic_handle_irq(struct irq_desc *desc)
> > +{
> > +     struct irq_chip *chip = irq_desc_get_chip(desc);
> > +     irq_hw_number_t hwirq;
> > +     int err;
> > +
> > +     chained_irq_enter(chip, desc);
> > +
> > +     while ((hwirq = csr_swap(CSR_TOPEI, 0))) {
> > +             hwirq = hwirq >> TOPEI_ID_SHIFT;
> > +
> > +             if (hwirq == imsic->ipi_id) {
> > +#ifdef CONFIG_SMP
> > +                     ipi_mux_process();
> > +#endif
> > +                     continue;
> > +             }
> > +
> > +             if (unlikely(!imsic->base_domain))
> > +                     continue;
> > +
> > +             err = generic_handle_domain_irq(imsic->base_domain, hwirq);
> > +             if (unlikely(err))
> > +                     pr_warn_ratelimited(
> > +                             "hwirq %lu mapping not found\n", hwirq);
> > +     }
> > +
> > +     chained_irq_exit(chip, desc);
> > +}
> > +
> > +static int imsic_starting_cpu(unsigned int cpu)
> > +{
> > +     /* Enable per-CPU parent interrupt */
> > +     enable_percpu_irq(imsic_parent_irq,
> > +                       irq_get_trigger_type(imsic_parent_irq));
> > +
> > +     /* Setup IPIs */
> > +     imsic_ipi_starting_cpu();
> > +
> > +     /*
> > +      * Interrupts identities might have been enabled/disabled while
> > +      * this CPU was not running so sync-up local enable/disable state.
> > +      */
> > +     imsic_ids_local_sync();
> > +
> > +     /* Enable local interrupt delivery */
> > +     imsic_ids_local_delivery(true);
> > +
> > +     return 0;
> > +}
> > +
> > +static int imsic_dying_cpu(unsigned int cpu)
> > +{
> > +     /* Cleanup IPIs */
> > +     imsic_ipi_dying_cpu();
> > +
> > +     return 0;
> > +}
> > +
> > +static int __init imsic_early_probe(struct fwnode_handle *fwnode)
> > +{
> > +     int rc;
> > +     struct irq_domain *domain;
> > +
> > +     /* Setup IMSIC state */
> > +     rc = imsic_setup_state(fwnode);
> > +     if (rc) {
> > +             pr_err("%pfwP: failed to setup state (error %d)\n",
> > +                     fwnode, rc);
> > +             return rc;
> > +     }
> > +
> > +     /* Find parent domain and register chained handler */
> > +     domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
> > +                                       DOMAIN_BUS_ANY);
> > +     if (!domain) {
> > +             pr_err("%pfwP: Failed to find INTC domain\n", fwnode);
> > +             return -ENOENT;
> > +     }
> > +     imsic_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT);
> > +     if (!imsic_parent_irq) {
> > +             pr_err("%pfwP: Failed to create INTC mapping\n", fwnode);
> > +             return -ENOENT;
> > +     }
> > +     irq_set_chained_handler(imsic_parent_irq, imsic_handle_irq);
> > +
> > +     /* Initialize IPI domain */
> > +     rc = imsic_ipi_domain_init();
> > +     if (rc) {
> > +             pr_err("%pfwP: Failed to initialize IPI domain\n", fwnode);
> > +             return rc;
> > +     }
> > +
> > +     /*
> > +      * Setup cpuhp state (must be done after setting imsic_parent_irq)
> > +      *
> > +      * Don't disable per-CPU IMSIC file when CPU goes offline
> > +      * because this affects IPI and the masking/unmasking of
> > +      * virtual IPIs is done via generic IPI-Mux
> > +      */
> > +     cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
> > +                       "irqchip/riscv/imsic:starting",
> > +                       imsic_starting_cpu, imsic_dying_cpu);
> > +
> > +     return 0;
> > +}
> > +
> > +static int __init imsic_early_dt_init(struct device_node *node,
> > +                                   struct device_node *parent)
> > +{
> > +     int rc;
> > +
> > +     /* Do early setup of IMSIC state and IPIs */
> > +     rc = imsic_early_probe(&node->fwnode);
> > +     if (rc)
> > +             return rc;
> > +
> > +     /* Ensure that OF platform device gets probed */
> > +     of_node_clear_flag(node, OF_POPULATED);
> > +     return 0;
> > +}
> > +IRQCHIP_DECLARE(riscv_imsic, "riscv,imsics", imsic_early_dt_init);
> > diff --git a/drivers/irqchip/irq-riscv-imsic-state.c b/drivers/irqchip/irq-riscv-imsic-state.c
> > new file mode 100644
> > index 000000000000..412b5b919dcc
> > --- /dev/null
> > +++ b/drivers/irqchip/irq-riscv-imsic-state.c
> > @@ -0,0 +1,523 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +
> > +#define pr_fmt(fmt) "riscv-imsic: " fmt
> > +#include <linux/bitmap.h>
> > +#include <linux/module.h>
> > +#include <linux/of_address.h>
> > +#include <linux/spinlock.h>
> > +#include <linux/smp.h>
> > +#include <asm/hwcap.h>
> > +
> > +#include "irq-riscv-imsic-state.h"
> > +
> > +#define IMSIC_DISABLE_EIDELIVERY             0
> > +#define IMSIC_ENABLE_EIDELIVERY                      1
> > +#define IMSIC_DISABLE_EITHRESHOLD            1
> > +#define IMSIC_ENABLE_EITHRESHOLD             0
> > +
> > +#define imsic_csr_write(__c, __v)            \
> > +do {                                         \
> > +     csr_write(CSR_ISELECT, __c);            \
> > +     csr_write(CSR_IREG, __v);               \
> > +} while (0)
> > +
> > +#define imsic_csr_read(__c)                  \
> > +({                                           \
> > +     unsigned long __v;                      \
> > +     csr_write(CSR_ISELECT, __c);            \
> > +     __v = csr_read(CSR_IREG);               \
> > +     __v;                                    \
> > +})
> > +
> > +#define imsic_csr_set(__c, __v)                      \
> > +do {                                         \
> > +     csr_write(CSR_ISELECT, __c);            \
> > +     csr_set(CSR_IREG, __v);                 \
> > +} while (0)
> > +
> > +#define imsic_csr_clear(__c, __v)            \
> > +do {                                         \
> > +     csr_write(CSR_ISELECT, __c);            \
> > +     csr_clear(CSR_IREG, __v);               \
> > +} while (0)
> > +
> > +struct imsic_priv *imsic;
> > +
> > +const struct imsic_global_config *imsic_get_global_config(void)
> > +{
> > +     return (imsic) ? &imsic->global : NULL;
> > +}
> > +EXPORT_SYMBOL_GPL(imsic_get_global_config);
> > +
> > +void __imsic_eix_update(unsigned long base_id,
> > +                     unsigned long num_id, bool pend, bool val)
> > +{
> > +     unsigned long i, isel, ireg;
> > +     unsigned long id = base_id, last_id = base_id + num_id;
> > +
> > +     while (id < last_id) {
> > +             isel = id / BITS_PER_LONG;
> > +             isel *= BITS_PER_LONG / IMSIC_EIPx_BITS;
> > +             isel += (pend) ? IMSIC_EIP0 : IMSIC_EIE0;
> > +
> > +             ireg = 0;
> > +             for (i = id & (__riscv_xlen - 1);
> > +                  (id < last_id) && (i < __riscv_xlen); i++) {
> > +                     ireg |= BIT(i);
> > +                     id++;
> > +             }
> > +
> > +             /*
> > +              * The IMSIC EIEx and EIPx registers are indirectly
> > +              * accessed via using ISELECT and IREG CSRs so we
> > +              * need to access these CSRs without getting preempted.
> > +              *
> > +              * All existing users of this function call this
> > +              * function with local IRQs disabled so we don't
> > +              * need to do anything special here.
> > +              */
> > +             if (val)
> > +                     imsic_csr_set(isel, ireg);
> > +             else
> > +                     imsic_csr_clear(isel, ireg);
> > +     }
> > +}
> > +
> > +void imsic_id_set_target(unsigned int id, unsigned int target_cpu)
> > +{
> > +     unsigned long flags;
> > +
> > +     raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> > +     imsic->ids_target_cpu[id] = target_cpu;
> > +     raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> > +}
> > +
> > +unsigned int imsic_id_get_target(unsigned int id)
> > +{
> > +     unsigned int ret;
> > +     unsigned long flags;
> > +
> > +     raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> > +     ret = imsic->ids_target_cpu[id];
> > +     raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> > +
> > +     return ret;
> > +}
> > +
> > +void imsic_ids_local_sync(void)
> > +{
> > +     int i;
> > +     unsigned long flags;
> > +
> > +     raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> > +     for (i = 1; i <= imsic->global.nr_ids; i++) {
> > +             if (imsic->ipi_id == i)
> > +                     continue;
> > +
> > +             if (test_bit(i, imsic->ids_enabled_bimap))
> > +                     __imsic_id_enable(i);
> > +             else
> > +                     __imsic_id_disable(i);
> > +     }
> > +     raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> > +}
> > +
> > +void imsic_ids_local_delivery(bool enable)
> > +{
> > +     if (enable) {
> > +             imsic_csr_write(IMSIC_EITHRESHOLD, IMSIC_ENABLE_EITHRESHOLD);
> > +             imsic_csr_write(IMSIC_EIDELIVERY, IMSIC_ENABLE_EIDELIVERY);
> > +     } else {
> > +             imsic_csr_write(IMSIC_EIDELIVERY, IMSIC_DISABLE_EIDELIVERY);
> > +             imsic_csr_write(IMSIC_EITHRESHOLD, IMSIC_DISABLE_EITHRESHOLD);
> > +     }
> > +}
> > +
> > +int imsic_ids_alloc(unsigned int order)
> > +{
> > +     int ret;
> > +     unsigned long flags;
> > +
> > +     raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> > +     ret = bitmap_find_free_region(imsic->ids_used_bimap,
> > +                                   imsic->global.nr_ids + 1, order);
> > +     raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> > +
> > +     return ret;
> > +}
> > +
> > +void imsic_ids_free(unsigned int base_id, unsigned int order)
> > +{
> > +     unsigned long flags;
> > +
> > +     raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> > +     bitmap_release_region(imsic->ids_used_bimap, base_id, order);
> > +     raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> > +}
> > +
> > +static int __init imsic_ids_init(void)
> > +{
> > +     int i;
> > +     struct imsic_global_config *global = &imsic->global;
> > +
> > +     raw_spin_lock_init(&imsic->ids_lock);
> > +
> > +     /* Allocate used bitmap */
> > +     imsic->ids_used_bimap = bitmap_zalloc(global->nr_ids + 1, GFP_KERNEL);
> > +     if (!imsic->ids_used_bimap)
> > +             return -ENOMEM;
> > +
> > +     /* Allocate enabled bitmap */
> > +     imsic->ids_enabled_bimap = bitmap_zalloc(global->nr_ids + 1,
> > +                                             GFP_KERNEL);
> > +     if (!imsic->ids_enabled_bimap) {
> > +             kfree(imsic->ids_used_bimap);
> > +             return -ENOMEM;
> > +     }
> > +
> > +     /* Allocate target CPU array */
> > +     imsic->ids_target_cpu = kcalloc(global->nr_ids + 1,
> > +                                    sizeof(unsigned int), GFP_KERNEL);
> > +     if (!imsic->ids_target_cpu) {
> > +             bitmap_free(imsic->ids_enabled_bimap);
> > +             bitmap_free(imsic->ids_used_bimap);
> > +             return -ENOMEM;
> > +     }
> > +     for (i = 0; i <= global->nr_ids; i++)
> > +             imsic->ids_target_cpu[i] = UINT_MAX;
> > +
> > +     /* Reserve ID#0 because it is special and never implemented */
> > +     bitmap_set(imsic->ids_used_bimap, 0, 1);
> > +
> > +     return 0;
> > +}
> > +
> > +static void __init imsic_ids_cleanup(void)
> > +{
> > +     kfree(imsic->ids_target_cpu);
> > +     bitmap_free(imsic->ids_enabled_bimap);
> > +     bitmap_free(imsic->ids_used_bimap);
> > +}
> > +
> > +static int __init imsic_get_parent_hartid(struct fwnode_handle *fwnode,
> > +                                       u32 index, unsigned long *hartid)
> > +{
> > +     int rc;
> > +     struct fwnode_reference_args parent;
> > +
> > +     rc = fwnode_property_get_reference_args(fwnode,
> > +                     "interrupts-extended", "#interrupt-cells",
> > +                     0, index, &parent);
> > +     if (rc)
> > +             return rc;
> > +
> > +     /*
> > +      * Skip interrupts other than external interrupts for
> > +      * current privilege level.
> > +      */
> > +     if (parent.args[0] != RV_IRQ_EXT)
> > +             return -EINVAL;
> > +
> > +     return riscv_get_intc_hartid(parent.fwnode, hartid);
> > +}
> > +
> > +static int __init imsic_get_mmio_resource(struct fwnode_handle *fwnode,
> > +                                       u32 index, struct resource *res)
> > +{
> > +     /*
> > +      * Currently, only OF fwnode is support so extend this function
> > +      * for other types of fwnode for ACPI support.
> > +      */
> > +     if (!is_of_node(fwnode))
> > +             return -EINVAL;
> > +     return of_address_to_resource(to_of_node(fwnode), index, res);
> > +}
> > +
> > +int __init imsic_setup_state(struct fwnode_handle *fwnode)
> > +{
> > +     int rc, cpu;
> > +     phys_addr_t base_addr;
> > +     void __iomem **mmios_va = NULL;
> > +     struct resource res, *mmios = NULL;
> > +     struct imsic_local_config *local;
> > +     struct imsic_global_config *global;
> > +     unsigned long reloff, hartid;
> > +     u32 i, j, index, nr_parent_irqs, nr_handlers = 0, num_mmios = 0;
> > +
> > +     /*
> > +      * Only one IMSIC instance allowed in a platform for clean
> > +      * implementation of SMP IRQ affinity and per-CPU IPIs.
> > +      *
> > +      * This means on a multi-socket (or multi-die) platform we
> > +      * will have multiple MMIO regions for one IMSIC instance.
> > +      */
> > +     if (imsic) {
> > +             pr_err("%pfwP: already initialized hence ignoring\n",
> > +                     fwnode);
> > +             return -EALREADY;
> > +     }
> > +
> > +     if (!riscv_isa_extension_available(NULL, SxAIA)) {
> > +             pr_err("%pfwP: AIA support not available\n", fwnode);
> > +             return -ENODEV;
> > +     }
> > +
> > +     imsic = kzalloc(sizeof(*imsic), GFP_KERNEL);
> > +     if (!imsic)
> > +             return -ENOMEM;
> > +     imsic->fwnode = fwnode;
> > +     global = &imsic->global;
> > +
> > +     global->local = alloc_percpu(typeof(*(global->local)));
> > +     if (!global->local) {
> > +             rc = -ENOMEM;
> > +             goto out_free_priv;
> > +     }
> > +
> > +     /* Find number of parent interrupts */
> > +     nr_parent_irqs = 0;
> > +     while (!imsic_get_parent_hartid(fwnode, nr_parent_irqs, &hartid))
> > +             nr_parent_irqs++;
> > +     if (!nr_parent_irqs) {
> > +             pr_err("%pfwP: no parent irqs available\n", fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +
> > +     /* Find number of guest index bits in MSI address */
> > +     rc = fwnode_property_read_u32_array(fwnode, "riscv,guest-index-bits",
> > +                                         &global->guest_index_bits, 1);
> > +     if (rc)
> > +             global->guest_index_bits = 0;
> > +     i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT;
> > +     if (i < global->guest_index_bits) {
> > +             pr_err("%pfwP: guest index bits too big\n", fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +
> > +     /* Find number of HART index bits */
> > +     rc = fwnode_property_read_u32_array(fwnode, "riscv,hart-index-bits",
> > +                                         &global->hart_index_bits, 1);
> > +     if (rc) {
> > +             /* Assume default value */
> > +             global->hart_index_bits = __fls(nr_parent_irqs);
> > +             if (BIT(global->hart_index_bits) < nr_parent_irqs)
> > +                     global->hart_index_bits++;
> > +     }
> > +     i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT - global->guest_index_bits;
> > +     if (i < global->hart_index_bits) {
> > +             pr_err("%pfwP: HART index bits too big\n", fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +
> > +     /* Find number of group index bits */
> > +     rc = fwnode_property_read_u32_array(fwnode, "riscv,group-index-bits",
> > +                                         &global->group_index_bits, 1);
> > +     if (rc)
> > +             global->group_index_bits = 0;
> > +     i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT -
> > +         global->guest_index_bits - global->hart_index_bits;
> > +     if (i < global->group_index_bits) {
> > +             pr_err("%pfwP: group index bits too big\n", fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +
> > +     /*
> > +      * Find first bit position of group index.
> > +      * If not specified assumed the default APLIC-IMSIC configuration.
> > +      */
> > +     rc = fwnode_property_read_u32_array(fwnode, "riscv,group-index-shift",
> > +                                         &global->group_index_shift, 1);
> > +     if (rc)
> > +             global->group_index_shift = IMSIC_MMIO_PAGE_SHIFT * 2;
> > +     i = global->group_index_bits + global->group_index_shift - 1;
> > +     if (i >= BITS_PER_LONG) {
> > +             pr_err("%pfwP: group index shift too big\n", fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +
> > +     /* Find number of interrupt identities */
> > +     rc = fwnode_property_read_u32_array(fwnode, "riscv,num-ids",
> > +                                         &global->nr_ids, 1);
> > +     if (rc) {
> > +             pr_err("%pfwP: number of interrupt identities not found\n",
> > +                     fwnode);
> > +             goto out_free_local;
> > +     }
> > +     if ((global->nr_ids < IMSIC_MIN_ID) ||
> > +         (global->nr_ids >= IMSIC_MAX_ID) ||
> > +         ((global->nr_ids & IMSIC_MIN_ID) != IMSIC_MIN_ID)) {
> > +             pr_err("%pfwP: invalid number of interrupt identities\n",
> > +                     fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +
> > +     /* Find number of guest interrupt identities */
> > +     if (fwnode_property_read_u32_array(fwnode, "riscv,num-guest-ids",
> > +                                        &global->nr_guest_ids, 1))
> > +             global->nr_guest_ids = global->nr_ids;
> > +     if ((global->nr_guest_ids < IMSIC_MIN_ID) ||
> > +         (global->nr_guest_ids >= IMSIC_MAX_ID) ||
> > +         ((global->nr_guest_ids & IMSIC_MIN_ID) != IMSIC_MIN_ID)) {
> > +             pr_err("%pfwP: invalid number of guest interrupt identities\n",
> > +                     fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +
> > +     /* Compute base address */
> > +     rc = imsic_get_mmio_resource(fwnode, 0, &res);
> > +     if (rc) {
> > +             pr_err("%pfwP: first MMIO resource not found\n", fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +     global->base_addr = res.start;
> > +     global->base_addr &= ~(BIT(global->guest_index_bits +
> > +                                global->hart_index_bits +
> > +                                IMSIC_MMIO_PAGE_SHIFT) - 1);
> > +     global->base_addr &= ~((BIT(global->group_index_bits) - 1) <<
> > +                            global->group_index_shift);
> > +
> > +     /* Find number of MMIO register sets */
> > +     while (!imsic_get_mmio_resource(fwnode, num_mmios, &res))
> > +             num_mmios++;
> > +
> > +     /* Allocate MMIO resource array */
> > +     mmios = kcalloc(num_mmios, sizeof(*mmios), GFP_KERNEL);
> > +     if (!mmios) {
> > +             rc = -ENOMEM;
> > +             goto out_free_local;
> > +     }
> > +
> > +     /* Allocate MMIO virtual address array */
> > +     mmios_va = kcalloc(num_mmios, sizeof(*mmios_va), GFP_KERNEL);
> > +     if (!mmios_va) {
> > +             rc = -ENOMEM;
> > +             goto out_iounmap;
> > +     }
> > +
> > +     /* Parse and map MMIO register sets */
> > +     for (i = 0; i < num_mmios; i++) {
> > +             rc = imsic_get_mmio_resource(fwnode, i, &mmios[i]);
> > +             if (rc) {
> > +                     pr_err("%pfwP: unable to parse MMIO regset %d\n",
> > +                             fwnode, i);
> > +                     goto out_iounmap;
> > +             }
> > +
> > +             base_addr = mmios[i].start;
> > +             base_addr &= ~(BIT(global->guest_index_bits +
> > +                                global->hart_index_bits +
> > +                                IMSIC_MMIO_PAGE_SHIFT) - 1);
> > +             base_addr &= ~((BIT(global->group_index_bits) - 1) <<
> > +                            global->group_index_shift);
> > +             if (base_addr != global->base_addr) {
> > +                     rc = -EINVAL;
> > +                     pr_err("%pfwP: address mismatch for regset %d\n",
> > +                             fwnode, i);
> > +                     goto out_iounmap;
> > +             }
> > +
> > +             mmios_va[i] = ioremap(mmios[i].start, resource_size(&mmios[i]));
> > +             if (!mmios_va[i]) {
> > +                     rc = -EIO;
> > +                     pr_err("%pfwP: unable to map MMIO regset %d\n",
> > +                             fwnode, i);
> > +                     goto out_iounmap;
> > +             }
> > +     }
> > +
> > +     /* Initialize interrupt identity management */
> > +     rc = imsic_ids_init();
> > +     if (rc) {
> > +             pr_err("%pfwP: failed to initialize interrupt management\n",
> > +                    fwnode);
> > +             goto out_iounmap;
> > +     }
> > +
> > +     /* Configure handlers for target CPUs */
> > +     for (i = 0; i < nr_parent_irqs; i++) {
> > +             rc = imsic_get_parent_hartid(fwnode, i, &hartid);
> > +             if (rc) {
> > +                     pr_warn("%pfwP: hart ID for parent irq%d not found\n",
> > +                             fwnode, i);
> > +                     continue;
> > +             }
> > +
> > +             cpu = riscv_hartid_to_cpuid(hartid);
> > +             if (cpu < 0) {
> > +                     pr_warn("%pfwP: invalid cpuid for parent irq%d\n",
> > +                             fwnode, i);
> > +                     continue;
> > +             }
> > +
> > +             /* Find MMIO location of MSI page */
> > +             index = num_mmios;
> > +             reloff = i * BIT(global->guest_index_bits) *
> > +                      IMSIC_MMIO_PAGE_SZ;
> > +             for (j = 0; num_mmios; j++) {
> > +                     if (reloff < resource_size(&mmios[j])) {
> > +                             index = j;
> > +                             break;
> > +                     }
> > +
> > +                     /*
> > +                      * MMIO region size may not be aligned to
> > +                      * BIT(global->guest_index_bits) * IMSIC_MMIO_PAGE_SZ
> > +                      * if holes are present.
> > +                      */
> > +                     reloff -= ALIGN(resource_size(&mmios[j]),
> > +                     BIT(global->guest_index_bits) * IMSIC_MMIO_PAGE_SZ);
> > +             }
> > +             if (index >= num_mmios) {
> > +                     pr_warn("%pfwP: MMIO not found for parent irq%d\n",
> > +                             fwnode, i);
> > +                     continue;
> > +             }
> > +
> > +             local = per_cpu_ptr(global->local, cpu);
> > +             local->msi_pa = mmios[index].start + reloff;
> > +             local->msi_va = mmios_va[index] + reloff;
> > +
> > +             nr_handlers++;
> > +     }
> > +
> > +     /* If no CPU handlers found then can't take interrupts */
> > +     if (!nr_handlers) {
> > +             pr_err("%pfwP: No CPU handlers found\n", fwnode);
> > +             rc = -ENODEV;
> > +             goto out_ids_cleanup;
> > +     }
> > +
> > +     /* We don't need MMIO arrays anymore so let's free-up */
> > +     kfree(mmios_va);
> > +     kfree(mmios);
> > +
> > +     return 0;
> > +
> > +out_ids_cleanup:
> > +     imsic_ids_cleanup();
> > +out_iounmap:
> > +     for (i = 0; i < num_mmios; i++) {
> > +             if (mmios_va[i])
> > +                     iounmap(mmios_va[i]);
> > +     }
> > +     kfree(mmios_va);
> > +     kfree(mmios);
> > +out_free_local:
> > +     free_percpu(imsic->global.local);
> > +out_free_priv:
> > +     kfree(imsic);
> > +     imsic = NULL;
> > +     return rc;
> > +}
> > diff --git a/drivers/irqchip/irq-riscv-imsic-state.h b/drivers/irqchip/irq-riscv-imsic-state.h
> > new file mode 100644
> > index 000000000000..3170018949a8
> > --- /dev/null
> > +++ b/drivers/irqchip/irq-riscv-imsic-state.h
> > @@ -0,0 +1,66 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only */
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +
> > +#ifndef _IRQ_RISCV_IMSIC_STATE_H
> > +#define _IRQ_RISCV_IMSIC_STATE_H
> > +
> > +#include <linux/irqchip/riscv-imsic.h>
> > +#include <linux/irqdomain.h>
> > +#include <linux/fwnode.h>
> > +
> > +struct imsic_priv {
> > +     /* Device details */
> > +     struct fwnode_handle *fwnode;
> > +
> > +     /* Global configuration common for all HARTs */
> > +     struct imsic_global_config global;
> > +
> > +     /* Global state of interrupt identities */
> > +     raw_spinlock_t ids_lock;
> > +     unsigned long *ids_used_bimap;
> > +     unsigned long *ids_enabled_bimap;
> > +     unsigned int *ids_target_cpu;
> > +
> > +     /* IPI interrupt identity and synchronization */
> > +     u32 ipi_id;
> > +     int ipi_virq;
> > +     struct irq_desc *ipi_lsync_desc;
> > +
> > +     /* IRQ domains (created by platform driver) */
> > +     struct irq_domain *base_domain;
> > +     struct irq_domain *plat_domain;
> > +};
> > +
> > +extern struct imsic_priv *imsic;
> > +
> > +void __imsic_eix_update(unsigned long base_id,
> > +                     unsigned long num_id, bool pend, bool val);
> > +
> > +#define __imsic_id_enable(__id)              \
> > +     __imsic_eix_update((__id), 1, false, true)
> > +#define __imsic_id_disable(__id)     \
> > +     __imsic_eix_update((__id), 1, false, false)
> > +
> > +void imsic_id_set_target(unsigned int id, unsigned int target_cpu);
> > +unsigned int imsic_id_get_target(unsigned int id);
> > +
> > +void imsic_ids_local_sync(void);
> > +void imsic_ids_local_delivery(bool enable);
> > +
> > +#ifdef CONFIG_SMP
> > +void imsic_ids_remote_sync(void);
> > +#else
> > +static inline void imsic_ids_remote_sync(void)
> > +{
> > +}
> > +#endif
> > +
> > +int imsic_ids_alloc(unsigned int order);
> > +void imsic_ids_free(unsigned int base_id, unsigned int order);
> > +
> > +int imsic_setup_state(struct fwnode_handle *fwnode);
> > +
> > +#endif
> > diff --git a/include/linux/irqchip/riscv-imsic.h b/include/linux/irqchip/riscv-imsic.h
> > new file mode 100644
> > index 000000000000..1f6fc9a57218
> > --- /dev/null
> > +++ b/include/linux/irqchip/riscv-imsic.h
> > @@ -0,0 +1,86 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only */
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +#ifndef __LINUX_IRQCHIP_RISCV_IMSIC_H
> > +#define __LINUX_IRQCHIP_RISCV_IMSIC_H
> > +
> > +#include <linux/types.h>
> > +#include <asm/csr.h>
> > +
> > +#define IMSIC_MMIO_PAGE_SHIFT                12
> > +#define IMSIC_MMIO_PAGE_SZ           (1UL << IMSIC_MMIO_PAGE_SHIFT)
> > +#define IMSIC_MMIO_PAGE_LE           0x00
> > +#define IMSIC_MMIO_PAGE_BE           0x04
> > +
> > +#define IMSIC_MIN_ID                 63
> > +#define IMSIC_MAX_ID                 2048
> > +
> > +#define IMSIC_EIDELIVERY             0x70
> > +
> > +#define IMSIC_EITHRESHOLD            0x72
> > +
> > +#define IMSIC_EIP0                   0x80
> > +#define IMSIC_EIP63                  0xbf
> > +#define IMSIC_EIPx_BITS                      32
> > +
> > +#define IMSIC_EIE0                   0xc0
> > +#define IMSIC_EIE63                  0xff
> > +#define IMSIC_EIEx_BITS                      32
> > +
> > +#define IMSIC_FIRST                  IMSIC_EIDELIVERY
> > +#define IMSIC_LAST                   IMSIC_EIE63
> > +
> > +#define IMSIC_MMIO_SETIPNUM_LE               0x00
> > +#define IMSIC_MMIO_SETIPNUM_BE               0x04
> > +
> > +struct imsic_local_config {
> > +     phys_addr_t msi_pa;
> > +     void __iomem *msi_va;
> > +};
> > +
> > +struct imsic_global_config {
> > +     /*
> > +      * MSI Target Address Scheme
> > +      *
> > +      * XLEN-1                                                12     0
> > +      * |                                                     |     |
> > +      * -------------------------------------------------------------
> > +      * |xxxxxx|Group Index|xxxxxxxxxxx|HART Index|Guest Index|  0  |
> > +      * -------------------------------------------------------------
> > +      */
> > +
> > +     /* Bits representing Guest index, HART index, and Group index */
> > +     u32 guest_index_bits;
> > +     u32 hart_index_bits;
> > +     u32 group_index_bits;
> > +     u32 group_index_shift;
> > +
> > +     /* Global base address matching all target MSI addresses */
> > +     phys_addr_t base_addr;
> > +
> > +     /* Number of interrupt identities */
> > +     u32 nr_ids;
> > +
> > +     /* Number of guest interrupt identities */
> > +     u32 nr_guest_ids;
> > +
> > +     /* Per-CPU IMSIC addresses */
> > +     struct imsic_local_config __percpu *local;
> > +};
> > +
> > +#ifdef CONFIG_RISCV_IMSIC
> > +
> > +extern const struct imsic_global_config *imsic_get_global_config(void);
> > +
> > +#else
> > +
> > +static inline const struct imsic_global_config *imsic_get_global_config(void)
> > +{
> > +     return NULL;
> > +}
> > +
> > +#endif
> > +
> > +#endif
> > --
> > 2.34.1
> >
> >
> > _______________________________________________
> > linux-riscv mailing list
> > linux-riscv@lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-riscv

Re: [PATCH v8 09/16] irqchip: Add RISC-V incoming MSI controller early driver

[Anup Patel]

On Wed, Sep 13, 2023 at 4:03 PM Emil Renner Berthing
<emil.renner.berthing@canonical.com> wrote:
>
> Anup Patel wrote:
> > The RISC-V advanced interrupt architecture (AIA) specification
> > defines a new MSI controller called incoming message signalled
> > interrupt controller (IMSIC) which manages MSI on per-HART (or
> > per-CPU) basis. It also supports IPIs as software injected MSIs.
> > (For more details refer https://github.com/riscv/riscv-aia)
> >
> > Let us add an early irqchip driver for RISC-V IMSIC which sets
> > up the IMSIC state and provide IPIs.
> >
> > Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> > ---
> >  drivers/irqchip/Kconfig                 |   7 +-
> >  drivers/irqchip/Makefile                |   1 +
> >  drivers/irqchip/irq-riscv-imsic-early.c | 258 ++++++++++++
> >  drivers/irqchip/irq-riscv-imsic-state.c | 523 ++++++++++++++++++++++++
> >  drivers/irqchip/irq-riscv-imsic-state.h |  66 +++
> >  include/linux/irqchip/riscv-imsic.h     |  86 ++++
> >  6 files changed, 940 insertions(+), 1 deletion(-)
> >  create mode 100644 drivers/irqchip/irq-riscv-imsic-early.c
> >  create mode 100644 drivers/irqchip/irq-riscv-imsic-state.c
> >  create mode 100644 drivers/irqchip/irq-riscv-imsic-state.h
> >  create mode 100644 include/linux/irqchip/riscv-imsic.h
> >
> > diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> > index f7149d0f3d45..ee99aacbefcc 100644
> > --- a/drivers/irqchip/Kconfig
> > +++ b/drivers/irqchip/Kconfig
> > @@ -30,7 +30,6 @@ config ARM_GIC_V2M
> >
> >  config GIC_NON_BANKED
> >       bool
> > -
>
> Hi Anup,
>
> This change looks like a mistake to me.

Ahh, yes. This change creeped in accidentally.

I will remove this change in the next revision.

Regards,
Anup

>
> /Emil
>
> >  config ARM_GIC_V3
> >       bool
> >       select IRQ_DOMAIN_HIERARCHY
> > @@ -546,6 +545,12 @@ config SIFIVE_PLIC
> >       select IRQ_DOMAIN_HIERARCHY
> >       select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
> >
> > +config RISCV_IMSIC
> > +     bool
> > +     depends on RISCV
> > +     select IRQ_DOMAIN_HIERARCHY
> > +     select GENERIC_MSI_IRQ
> > +
> >  config EXYNOS_IRQ_COMBINER
> >       bool "Samsung Exynos IRQ combiner support" if COMPILE_TEST
> >       depends on (ARCH_EXYNOS && ARM) || COMPILE_TEST
> > diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> > index ffd945fe71aa..d714724387ce 100644
> > --- a/drivers/irqchip/Makefile
> > +++ b/drivers/irqchip/Makefile
> > @@ -95,6 +95,7 @@ obj-$(CONFIG_QCOM_MPM)                      += irq-qcom-mpm.o
> >  obj-$(CONFIG_CSKY_MPINTC)            += irq-csky-mpintc.o
> >  obj-$(CONFIG_CSKY_APB_INTC)          += irq-csky-apb-intc.o
> >  obj-$(CONFIG_RISCV_INTC)             += irq-riscv-intc.o
> > +obj-$(CONFIG_RISCV_IMSIC)            += irq-riscv-imsic-state.o irq-riscv-imsic-early.o
> >  obj-$(CONFIG_SIFIVE_PLIC)            += irq-sifive-plic.o
> >  obj-$(CONFIG_IMX_IRQSTEER)           += irq-imx-irqsteer.o
> >  obj-$(CONFIG_IMX_INTMUX)             += irq-imx-intmux.o
> > diff --git a/drivers/irqchip/irq-riscv-imsic-early.c b/drivers/irqchip/irq-riscv-imsic-early.c
> > new file mode 100644
> > index 000000000000..1de89ce1ec2f
> > --- /dev/null
> > +++ b/drivers/irqchip/irq-riscv-imsic-early.c
> > @@ -0,0 +1,258 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +
> > +#define pr_fmt(fmt) "riscv-imsic: " fmt
> > +#include <linux/cpu.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/io.h>
> > +#include <linux/irq.h>
> > +#include <linux/irqchip.h>
> > +#include <linux/irqchip/chained_irq.h>
> > +#include <linux/module.h>
> > +#include <linux/spinlock.h>
> > +#include <linux/smp.h>
> > +
> > +#include "irq-riscv-imsic-state.h"
> > +
> > +/*
> > + * The IMSIC driver uses 1 IPI for ID synchronization and
> > + * arch/riscv/kernel/smp.c require 6 IPIs so we fix the
> > + * total number of IPIs to 8.
> > + */
> > +#define IMSIC_NR_IPI                         8
> > +
> > +static int imsic_parent_irq;
> > +
> > +#ifdef CONFIG_SMP
> > +static irqreturn_t imsic_ids_sync_handler(int irq, void *data)
> > +{
> > +     imsic_ids_local_sync();
> > +     return IRQ_HANDLED;
> > +}
> > +
> > +void imsic_ids_remote_sync(void)
> > +{
> > +     struct cpumask amask;
> > +
> > +     /*
> > +      * We simply inject ID synchronization IPI to all target CPUs
> > +      * except current CPU. The ipi_send_mask() implementation of
> > +      * IPI mux will inject ID synchronization IPI only for CPUs
> > +      * that have enabled it so offline CPUs won't receive IPI.
> > +      * An offline CPU will unconditionally synchronize IDs through
> > +      * imsic_starting_cpu() when the CPU is brought up.
> > +      */
> > +     cpumask_andnot(&amask, cpu_online_mask, cpumask_of(smp_processor_id()));
> > +     __ipi_send_mask(imsic->ipi_lsync_desc, &amask);
> > +}
> > +
> > +static void imsic_ipi_send(unsigned int cpu)
> > +{
> > +     struct imsic_local_config *local =
> > +                             per_cpu_ptr(imsic->global.local, cpu);
> > +
> > +     writel(imsic->ipi_id, local->msi_va);
> > +}
> > +
> > +static void imsic_ipi_starting_cpu(void)
> > +{
> > +     /* Enable IPIs for current CPU. */
> > +     __imsic_id_enable(imsic->ipi_id);
> > +
> > +     /* Enable virtual IPI used for IMSIC ID synchronization */
> > +     enable_percpu_irq(imsic->ipi_virq, 0);
> > +}
> > +
> > +static void imsic_ipi_dying_cpu(void)
> > +{
> > +     /*
> > +      * Disable virtual IPI used for IMSIC ID synchronization so
> > +      * that we don't receive ID synchronization requests.
> > +      */
> > +     disable_percpu_irq(imsic->ipi_virq);
> > +}
> > +
> > +static int __init imsic_ipi_domain_init(void)
> > +{
> > +     int virq;
> > +
> > +     /* Allocate interrupt identity for IPIs */
> > +     virq = imsic_ids_alloc(get_count_order(1));
> > +     if (virq < 0)
> > +             return virq;
> > +     imsic->ipi_id = virq;
> > +
> > +     /* Create IMSIC IPI multiplexing */
> > +     virq = ipi_mux_create(IMSIC_NR_IPI, imsic_ipi_send);
> > +     if (virq <= 0) {
> > +             imsic_ids_free(imsic->ipi_id, get_count_order(1));
> > +             return (virq < 0) ? virq : -ENOMEM;
> > +     }
> > +     imsic->ipi_virq = virq;
> > +
> > +     /* First vIRQ is used for IMSIC ID synchronization */
> > +     virq = request_percpu_irq(imsic->ipi_virq, imsic_ids_sync_handler,
> > +                               "riscv-imsic-lsync", imsic->global.local);
> > +     if (virq) {
> > +             imsic_ids_free(imsic->ipi_id, get_count_order(1));
> > +             return virq;
> > +     }
> > +     irq_set_status_flags(imsic->ipi_virq, IRQ_HIDDEN);
> > +     imsic->ipi_lsync_desc = irq_to_desc(imsic->ipi_virq);
> > +
> > +     /* Set vIRQ range */
> > +     riscv_ipi_set_virq_range(imsic->ipi_virq + 1, IMSIC_NR_IPI - 1, true);
> > +
> > +     /* Announce that IMSIC is providing IPIs */
> > +     pr_info("%pfwP: providing IPIs using interrupt %d\n",
> > +             imsic->fwnode, imsic->ipi_id);
> > +
> > +     return 0;
> > +}
> > +#else
> > +static void imsic_ipi_starting_cpu(void)
> > +{
> > +}
> > +
> > +static void imsic_ipi_dying_cpu(void)
> > +{
> > +}
> > +
> > +static int __init imsic_ipi_domain_init(void)
> > +{
> > +     /* Clear the IPI id because we are not using IPIs */
> > +     imsic->ipi_id = 0;
> > +     return 0;
> > +}
> > +#endif
> > +
> > +/*
> > + * To handle an interrupt, we read the TOPEI CSR and write zero in one
> > + * instruction. If TOPEI CSR is non-zero then we translate TOPEI.ID to
> > + * Linux interrupt number and let Linux IRQ subsystem handle it.
> > + */
> > +static void imsic_handle_irq(struct irq_desc *desc)
> > +{
> > +     struct irq_chip *chip = irq_desc_get_chip(desc);
> > +     irq_hw_number_t hwirq;
> > +     int err;
> > +
> > +     chained_irq_enter(chip, desc);
> > +
> > +     while ((hwirq = csr_swap(CSR_TOPEI, 0))) {
> > +             hwirq = hwirq >> TOPEI_ID_SHIFT;
> > +
> > +             if (hwirq == imsic->ipi_id) {
> > +#ifdef CONFIG_SMP
> > +                     ipi_mux_process();
> > +#endif
> > +                     continue;
> > +             }
> > +
> > +             if (unlikely(!imsic->base_domain))
> > +                     continue;
> > +
> > +             err = generic_handle_domain_irq(imsic->base_domain, hwirq);
> > +             if (unlikely(err))
> > +                     pr_warn_ratelimited(
> > +                             "hwirq %lu mapping not found\n", hwirq);
> > +     }
> > +
> > +     chained_irq_exit(chip, desc);
> > +}
> > +
> > +static int imsic_starting_cpu(unsigned int cpu)
> > +{
> > +     /* Enable per-CPU parent interrupt */
> > +     enable_percpu_irq(imsic_parent_irq,
> > +                       irq_get_trigger_type(imsic_parent_irq));
> > +
> > +     /* Setup IPIs */
> > +     imsic_ipi_starting_cpu();
> > +
> > +     /*
> > +      * Interrupts identities might have been enabled/disabled while
> > +      * this CPU was not running so sync-up local enable/disable state.
> > +      */
> > +     imsic_ids_local_sync();
> > +
> > +     /* Enable local interrupt delivery */
> > +     imsic_ids_local_delivery(true);
> > +
> > +     return 0;
> > +}
> > +
> > +static int imsic_dying_cpu(unsigned int cpu)
> > +{
> > +     /* Cleanup IPIs */
> > +     imsic_ipi_dying_cpu();
> > +
> > +     return 0;
> > +}
> > +
> > +static int __init imsic_early_probe(struct fwnode_handle *fwnode)
> > +{
> > +     int rc;
> > +     struct irq_domain *domain;
> > +
> > +     /* Setup IMSIC state */
> > +     rc = imsic_setup_state(fwnode);
> > +     if (rc) {
> > +             pr_err("%pfwP: failed to setup state (error %d)\n",
> > +                     fwnode, rc);
> > +             return rc;
> > +     }
> > +
> > +     /* Find parent domain and register chained handler */
> > +     domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
> > +                                       DOMAIN_BUS_ANY);
> > +     if (!domain) {
> > +             pr_err("%pfwP: Failed to find INTC domain\n", fwnode);
> > +             return -ENOENT;
> > +     }
> > +     imsic_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT);
> > +     if (!imsic_parent_irq) {
> > +             pr_err("%pfwP: Failed to create INTC mapping\n", fwnode);
> > +             return -ENOENT;
> > +     }
> > +     irq_set_chained_handler(imsic_parent_irq, imsic_handle_irq);
> > +
> > +     /* Initialize IPI domain */
> > +     rc = imsic_ipi_domain_init();
> > +     if (rc) {
> > +             pr_err("%pfwP: Failed to initialize IPI domain\n", fwnode);
> > +             return rc;
> > +     }
> > +
> > +     /*
> > +      * Setup cpuhp state (must be done after setting imsic_parent_irq)
> > +      *
> > +      * Don't disable per-CPU IMSIC file when CPU goes offline
> > +      * because this affects IPI and the masking/unmasking of
> > +      * virtual IPIs is done via generic IPI-Mux
> > +      */
> > +     cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
> > +                       "irqchip/riscv/imsic:starting",
> > +                       imsic_starting_cpu, imsic_dying_cpu);
> > +
> > +     return 0;
> > +}
> > +
> > +static int __init imsic_early_dt_init(struct device_node *node,
> > +                                   struct device_node *parent)
> > +{
> > +     int rc;
> > +
> > +     /* Do early setup of IMSIC state and IPIs */
> > +     rc = imsic_early_probe(&node->fwnode);
> > +     if (rc)
> > +             return rc;
> > +
> > +     /* Ensure that OF platform device gets probed */
> > +     of_node_clear_flag(node, OF_POPULATED);
> > +     return 0;
> > +}
> > +IRQCHIP_DECLARE(riscv_imsic, "riscv,imsics", imsic_early_dt_init);
> > diff --git a/drivers/irqchip/irq-riscv-imsic-state.c b/drivers/irqchip/irq-riscv-imsic-state.c
> > new file mode 100644
> > index 000000000000..412b5b919dcc
> > --- /dev/null
> > +++ b/drivers/irqchip/irq-riscv-imsic-state.c
> > @@ -0,0 +1,523 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +
> > +#define pr_fmt(fmt) "riscv-imsic: " fmt
> > +#include <linux/bitmap.h>
> > +#include <linux/module.h>
> > +#include <linux/of_address.h>
> > +#include <linux/spinlock.h>
> > +#include <linux/smp.h>
> > +#include <asm/hwcap.h>
> > +
> > +#include "irq-riscv-imsic-state.h"
> > +
> > +#define IMSIC_DISABLE_EIDELIVERY             0
> > +#define IMSIC_ENABLE_EIDELIVERY                      1
> > +#define IMSIC_DISABLE_EITHRESHOLD            1
> > +#define IMSIC_ENABLE_EITHRESHOLD             0
> > +
> > +#define imsic_csr_write(__c, __v)            \
> > +do {                                         \
> > +     csr_write(CSR_ISELECT, __c);            \
> > +     csr_write(CSR_IREG, __v);               \
> > +} while (0)
> > +
> > +#define imsic_csr_read(__c)                  \
> > +({                                           \
> > +     unsigned long __v;                      \
> > +     csr_write(CSR_ISELECT, __c);            \
> > +     __v = csr_read(CSR_IREG);               \
> > +     __v;                                    \
> > +})
> > +
> > +#define imsic_csr_set(__c, __v)                      \
> > +do {                                         \
> > +     csr_write(CSR_ISELECT, __c);            \
> > +     csr_set(CSR_IREG, __v);                 \
> > +} while (0)
> > +
> > +#define imsic_csr_clear(__c, __v)            \
> > +do {                                         \
> > +     csr_write(CSR_ISELECT, __c);            \
> > +     csr_clear(CSR_IREG, __v);               \
> > +} while (0)
> > +
> > +struct imsic_priv *imsic;
> > +
> > +const struct imsic_global_config *imsic_get_global_config(void)
> > +{
> > +     return (imsic) ? &imsic->global : NULL;
> > +}
> > +EXPORT_SYMBOL_GPL(imsic_get_global_config);
> > +
> > +void __imsic_eix_update(unsigned long base_id,
> > +                     unsigned long num_id, bool pend, bool val)
> > +{
> > +     unsigned long i, isel, ireg;
> > +     unsigned long id = base_id, last_id = base_id + num_id;
> > +
> > +     while (id < last_id) {
> > +             isel = id / BITS_PER_LONG;
> > +             isel *= BITS_PER_LONG / IMSIC_EIPx_BITS;
> > +             isel += (pend) ? IMSIC_EIP0 : IMSIC_EIE0;
> > +
> > +             ireg = 0;
> > +             for (i = id & (__riscv_xlen - 1);
> > +                  (id < last_id) && (i < __riscv_xlen); i++) {
> > +                     ireg |= BIT(i);
> > +                     id++;
> > +             }
> > +
> > +             /*
> > +              * The IMSIC EIEx and EIPx registers are indirectly
> > +              * accessed via using ISELECT and IREG CSRs so we
> > +              * need to access these CSRs without getting preempted.
> > +              *
> > +              * All existing users of this function call this
> > +              * function with local IRQs disabled so we don't
> > +              * need to do anything special here.
> > +              */
> > +             if (val)
> > +                     imsic_csr_set(isel, ireg);
> > +             else
> > +                     imsic_csr_clear(isel, ireg);
> > +     }
> > +}
> > +
> > +void imsic_id_set_target(unsigned int id, unsigned int target_cpu)
> > +{
> > +     unsigned long flags;
> > +
> > +     raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> > +     imsic->ids_target_cpu[id] = target_cpu;
> > +     raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> > +}
> > +
> > +unsigned int imsic_id_get_target(unsigned int id)
> > +{
> > +     unsigned int ret;
> > +     unsigned long flags;
> > +
> > +     raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> > +     ret = imsic->ids_target_cpu[id];
> > +     raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> > +
> > +     return ret;
> > +}
> > +
> > +void imsic_ids_local_sync(void)
> > +{
> > +     int i;
> > +     unsigned long flags;
> > +
> > +     raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> > +     for (i = 1; i <= imsic->global.nr_ids; i++) {
> > +             if (imsic->ipi_id == i)
> > +                     continue;
> > +
> > +             if (test_bit(i, imsic->ids_enabled_bimap))
> > +                     __imsic_id_enable(i);
> > +             else
> > +                     __imsic_id_disable(i);
> > +     }
> > +     raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> > +}
> > +
> > +void imsic_ids_local_delivery(bool enable)
> > +{
> > +     if (enable) {
> > +             imsic_csr_write(IMSIC_EITHRESHOLD, IMSIC_ENABLE_EITHRESHOLD);
> > +             imsic_csr_write(IMSIC_EIDELIVERY, IMSIC_ENABLE_EIDELIVERY);
> > +     } else {
> > +             imsic_csr_write(IMSIC_EIDELIVERY, IMSIC_DISABLE_EIDELIVERY);
> > +             imsic_csr_write(IMSIC_EITHRESHOLD, IMSIC_DISABLE_EITHRESHOLD);
> > +     }
> > +}
> > +
> > +int imsic_ids_alloc(unsigned int order)
> > +{
> > +     int ret;
> > +     unsigned long flags;
> > +
> > +     raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> > +     ret = bitmap_find_free_region(imsic->ids_used_bimap,
> > +                                   imsic->global.nr_ids + 1, order);
> > +     raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> > +
> > +     return ret;
> > +}
> > +
> > +void imsic_ids_free(unsigned int base_id, unsigned int order)
> > +{
> > +     unsigned long flags;
> > +
> > +     raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> > +     bitmap_release_region(imsic->ids_used_bimap, base_id, order);
> > +     raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> > +}
> > +
> > +static int __init imsic_ids_init(void)
> > +{
> > +     int i;
> > +     struct imsic_global_config *global = &imsic->global;
> > +
> > +     raw_spin_lock_init(&imsic->ids_lock);
> > +
> > +     /* Allocate used bitmap */
> > +     imsic->ids_used_bimap = bitmap_zalloc(global->nr_ids + 1, GFP_KERNEL);
> > +     if (!imsic->ids_used_bimap)
> > +             return -ENOMEM;
> > +
> > +     /* Allocate enabled bitmap */
> > +     imsic->ids_enabled_bimap = bitmap_zalloc(global->nr_ids + 1,
> > +                                             GFP_KERNEL);
> > +     if (!imsic->ids_enabled_bimap) {
> > +             kfree(imsic->ids_used_bimap);
> > +             return -ENOMEM;
> > +     }
> > +
> > +     /* Allocate target CPU array */
> > +     imsic->ids_target_cpu = kcalloc(global->nr_ids + 1,
> > +                                    sizeof(unsigned int), GFP_KERNEL);
> > +     if (!imsic->ids_target_cpu) {
> > +             bitmap_free(imsic->ids_enabled_bimap);
> > +             bitmap_free(imsic->ids_used_bimap);
> > +             return -ENOMEM;
> > +     }
> > +     for (i = 0; i <= global->nr_ids; i++)
> > +             imsic->ids_target_cpu[i] = UINT_MAX;
> > +
> > +     /* Reserve ID#0 because it is special and never implemented */
> > +     bitmap_set(imsic->ids_used_bimap, 0, 1);
> > +
> > +     return 0;
> > +}
> > +
> > +static void __init imsic_ids_cleanup(void)
> > +{
> > +     kfree(imsic->ids_target_cpu);
> > +     bitmap_free(imsic->ids_enabled_bimap);
> > +     bitmap_free(imsic->ids_used_bimap);
> > +}
> > +
> > +static int __init imsic_get_parent_hartid(struct fwnode_handle *fwnode,
> > +                                       u32 index, unsigned long *hartid)
> > +{
> > +     int rc;
> > +     struct fwnode_reference_args parent;
> > +
> > +     rc = fwnode_property_get_reference_args(fwnode,
> > +                     "interrupts-extended", "#interrupt-cells",
> > +                     0, index, &parent);
> > +     if (rc)
> > +             return rc;
> > +
> > +     /*
> > +      * Skip interrupts other than external interrupts for
> > +      * current privilege level.
> > +      */
> > +     if (parent.args[0] != RV_IRQ_EXT)
> > +             return -EINVAL;
> > +
> > +     return riscv_get_intc_hartid(parent.fwnode, hartid);
> > +}
> > +
> > +static int __init imsic_get_mmio_resource(struct fwnode_handle *fwnode,
> > +                                       u32 index, struct resource *res)
> > +{
> > +     /*
> > +      * Currently, only OF fwnode is support so extend this function
> > +      * for other types of fwnode for ACPI support.
> > +      */
> > +     if (!is_of_node(fwnode))
> > +             return -EINVAL;
> > +     return of_address_to_resource(to_of_node(fwnode), index, res);
> > +}
> > +
> > +int __init imsic_setup_state(struct fwnode_handle *fwnode)
> > +{
> > +     int rc, cpu;
> > +     phys_addr_t base_addr;
> > +     void __iomem **mmios_va = NULL;
> > +     struct resource res, *mmios = NULL;
> > +     struct imsic_local_config *local;
> > +     struct imsic_global_config *global;
> > +     unsigned long reloff, hartid;
> > +     u32 i, j, index, nr_parent_irqs, nr_handlers = 0, num_mmios = 0;
> > +
> > +     /*
> > +      * Only one IMSIC instance allowed in a platform for clean
> > +      * implementation of SMP IRQ affinity and per-CPU IPIs.
> > +      *
> > +      * This means on a multi-socket (or multi-die) platform we
> > +      * will have multiple MMIO regions for one IMSIC instance.
> > +      */
> > +     if (imsic) {
> > +             pr_err("%pfwP: already initialized hence ignoring\n",
> > +                     fwnode);
> > +             return -EALREADY;
> > +     }
> > +
> > +     if (!riscv_isa_extension_available(NULL, SxAIA)) {
> > +             pr_err("%pfwP: AIA support not available\n", fwnode);
> > +             return -ENODEV;
> > +     }
> > +
> > +     imsic = kzalloc(sizeof(*imsic), GFP_KERNEL);
> > +     if (!imsic)
> > +             return -ENOMEM;
> > +     imsic->fwnode = fwnode;
> > +     global = &imsic->global;
> > +
> > +     global->local = alloc_percpu(typeof(*(global->local)));
> > +     if (!global->local) {
> > +             rc = -ENOMEM;
> > +             goto out_free_priv;
> > +     }
> > +
> > +     /* Find number of parent interrupts */
> > +     nr_parent_irqs = 0;
> > +     while (!imsic_get_parent_hartid(fwnode, nr_parent_irqs, &hartid))
> > +             nr_parent_irqs++;
> > +     if (!nr_parent_irqs) {
> > +             pr_err("%pfwP: no parent irqs available\n", fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +
> > +     /* Find number of guest index bits in MSI address */
> > +     rc = fwnode_property_read_u32_array(fwnode, "riscv,guest-index-bits",
> > +                                         &global->guest_index_bits, 1);
> > +     if (rc)
> > +             global->guest_index_bits = 0;
> > +     i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT;
> > +     if (i < global->guest_index_bits) {
> > +             pr_err("%pfwP: guest index bits too big\n", fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +
> > +     /* Find number of HART index bits */
> > +     rc = fwnode_property_read_u32_array(fwnode, "riscv,hart-index-bits",
> > +                                         &global->hart_index_bits, 1);
> > +     if (rc) {
> > +             /* Assume default value */
> > +             global->hart_index_bits = __fls(nr_parent_irqs);
> > +             if (BIT(global->hart_index_bits) < nr_parent_irqs)
> > +                     global->hart_index_bits++;
> > +     }
> > +     i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT - global->guest_index_bits;
> > +     if (i < global->hart_index_bits) {
> > +             pr_err("%pfwP: HART index bits too big\n", fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +
> > +     /* Find number of group index bits */
> > +     rc = fwnode_property_read_u32_array(fwnode, "riscv,group-index-bits",
> > +                                         &global->group_index_bits, 1);
> > +     if (rc)
> > +             global->group_index_bits = 0;
> > +     i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT -
> > +         global->guest_index_bits - global->hart_index_bits;
> > +     if (i < global->group_index_bits) {
> > +             pr_err("%pfwP: group index bits too big\n", fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +
> > +     /*
> > +      * Find first bit position of group index.
> > +      * If not specified assumed the default APLIC-IMSIC configuration.
> > +      */
> > +     rc = fwnode_property_read_u32_array(fwnode, "riscv,group-index-shift",
> > +                                         &global->group_index_shift, 1);
> > +     if (rc)
> > +             global->group_index_shift = IMSIC_MMIO_PAGE_SHIFT * 2;
> > +     i = global->group_index_bits + global->group_index_shift - 1;
> > +     if (i >= BITS_PER_LONG) {
> > +             pr_err("%pfwP: group index shift too big\n", fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +
> > +     /* Find number of interrupt identities */
> > +     rc = fwnode_property_read_u32_array(fwnode, "riscv,num-ids",
> > +                                         &global->nr_ids, 1);
> > +     if (rc) {
> > +             pr_err("%pfwP: number of interrupt identities not found\n",
> > +                     fwnode);
> > +             goto out_free_local;
> > +     }
> > +     if ((global->nr_ids < IMSIC_MIN_ID) ||
> > +         (global->nr_ids >= IMSIC_MAX_ID) ||
> > +         ((global->nr_ids & IMSIC_MIN_ID) != IMSIC_MIN_ID)) {
> > +             pr_err("%pfwP: invalid number of interrupt identities\n",
> > +                     fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +
> > +     /* Find number of guest interrupt identities */
> > +     if (fwnode_property_read_u32_array(fwnode, "riscv,num-guest-ids",
> > +                                        &global->nr_guest_ids, 1))
> > +             global->nr_guest_ids = global->nr_ids;
> > +     if ((global->nr_guest_ids < IMSIC_MIN_ID) ||
> > +         (global->nr_guest_ids >= IMSIC_MAX_ID) ||
> > +         ((global->nr_guest_ids & IMSIC_MIN_ID) != IMSIC_MIN_ID)) {
> > +             pr_err("%pfwP: invalid number of guest interrupt identities\n",
> > +                     fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +
> > +     /* Compute base address */
> > +     rc = imsic_get_mmio_resource(fwnode, 0, &res);
> > +     if (rc) {
> > +             pr_err("%pfwP: first MMIO resource not found\n", fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +     global->base_addr = res.start;
> > +     global->base_addr &= ~(BIT(global->guest_index_bits +
> > +                                global->hart_index_bits +
> > +                                IMSIC_MMIO_PAGE_SHIFT) - 1);
> > +     global->base_addr &= ~((BIT(global->group_index_bits) - 1) <<
> > +                            global->group_index_shift);
> > +
> > +     /* Find number of MMIO register sets */
> > +     while (!imsic_get_mmio_resource(fwnode, num_mmios, &res))
> > +             num_mmios++;
> > +
> > +     /* Allocate MMIO resource array */
> > +     mmios = kcalloc(num_mmios, sizeof(*mmios), GFP_KERNEL);
> > +     if (!mmios) {
> > +             rc = -ENOMEM;
> > +             goto out_free_local;
> > +     }
> > +
> > +     /* Allocate MMIO virtual address array */
> > +     mmios_va = kcalloc(num_mmios, sizeof(*mmios_va), GFP_KERNEL);
> > +     if (!mmios_va) {
> > +             rc = -ENOMEM;
> > +             goto out_iounmap;
> > +     }
> > +
> > +     /* Parse and map MMIO register sets */
> > +     for (i = 0; i < num_mmios; i++) {
> > +             rc = imsic_get_mmio_resource(fwnode, i, &mmios[i]);
> > +             if (rc) {
> > +                     pr_err("%pfwP: unable to parse MMIO regset %d\n",
> > +                             fwnode, i);
> > +                     goto out_iounmap;
> > +             }
> > +
> > +             base_addr = mmios[i].start;
> > +             base_addr &= ~(BIT(global->guest_index_bits +
> > +                                global->hart_index_bits +
> > +                                IMSIC_MMIO_PAGE_SHIFT) - 1);
> > +             base_addr &= ~((BIT(global->group_index_bits) - 1) <<
> > +                            global->group_index_shift);
> > +             if (base_addr != global->base_addr) {
> > +                     rc = -EINVAL;
> > +                     pr_err("%pfwP: address mismatch for regset %d\n",
> > +                             fwnode, i);
> > +                     goto out_iounmap;
> > +             }
> > +
> > +             mmios_va[i] = ioremap(mmios[i].start, resource_size(&mmios[i]));
> > +             if (!mmios_va[i]) {
> > +                     rc = -EIO;
> > +                     pr_err("%pfwP: unable to map MMIO regset %d\n",
> > +                             fwnode, i);
> > +                     goto out_iounmap;
> > +             }
> > +     }
> > +
> > +     /* Initialize interrupt identity management */
> > +     rc = imsic_ids_init();
> > +     if (rc) {
> > +             pr_err("%pfwP: failed to initialize interrupt management\n",
> > +                    fwnode);
> > +             goto out_iounmap;
> > +     }
> > +
> > +     /* Configure handlers for target CPUs */
> > +     for (i = 0; i < nr_parent_irqs; i++) {
> > +             rc = imsic_get_parent_hartid(fwnode, i, &hartid);
> > +             if (rc) {
> > +                     pr_warn("%pfwP: hart ID for parent irq%d not found\n",
> > +                             fwnode, i);
> > +                     continue;
> > +             }
> > +
> > +             cpu = riscv_hartid_to_cpuid(hartid);
> > +             if (cpu < 0) {
> > +                     pr_warn("%pfwP: invalid cpuid for parent irq%d\n",
> > +                             fwnode, i);
> > +                     continue;
> > +             }
> > +
> > +             /* Find MMIO location of MSI page */
> > +             index = num_mmios;
> > +             reloff = i * BIT(global->guest_index_bits) *
> > +                      IMSIC_MMIO_PAGE_SZ;
> > +             for (j = 0; num_mmios; j++) {
> > +                     if (reloff < resource_size(&mmios[j])) {
> > +                             index = j;
> > +                             break;
> > +                     }
> > +
> > +                     /*
> > +                      * MMIO region size may not be aligned to
> > +                      * BIT(global->guest_index_bits) * IMSIC_MMIO_PAGE_SZ
> > +                      * if holes are present.
> > +                      */
> > +                     reloff -= ALIGN(resource_size(&mmios[j]),
> > +                     BIT(global->guest_index_bits) * IMSIC_MMIO_PAGE_SZ);
> > +             }
> > +             if (index >= num_mmios) {
> > +                     pr_warn("%pfwP: MMIO not found for parent irq%d\n",
> > +                             fwnode, i);
> > +                     continue;
> > +             }
> > +
> > +             local = per_cpu_ptr(global->local, cpu);
> > +             local->msi_pa = mmios[index].start + reloff;
> > +             local->msi_va = mmios_va[index] + reloff;
> > +
> > +             nr_handlers++;
> > +     }
> > +
> > +     /* If no CPU handlers found then can't take interrupts */
> > +     if (!nr_handlers) {
> > +             pr_err("%pfwP: No CPU handlers found\n", fwnode);
> > +             rc = -ENODEV;
> > +             goto out_ids_cleanup;
> > +     }
> > +
> > +     /* We don't need MMIO arrays anymore so let's free-up */
> > +     kfree(mmios_va);
> > +     kfree(mmios);
> > +
> > +     return 0;
> > +
> > +out_ids_cleanup:
> > +     imsic_ids_cleanup();
> > +out_iounmap:
> > +     for (i = 0; i < num_mmios; i++) {
> > +             if (mmios_va[i])
> > +                     iounmap(mmios_va[i]);
> > +     }
> > +     kfree(mmios_va);
> > +     kfree(mmios);
> > +out_free_local:
> > +     free_percpu(imsic->global.local);
> > +out_free_priv:
> > +     kfree(imsic);
> > +     imsic = NULL;
> > +     return rc;
> > +}
> > diff --git a/drivers/irqchip/irq-riscv-imsic-state.h b/drivers/irqchip/irq-riscv-imsic-state.h
> > new file mode 100644
> > index 000000000000..3170018949a8
> > --- /dev/null
> > +++ b/drivers/irqchip/irq-riscv-imsic-state.h
> > @@ -0,0 +1,66 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only */
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +
> > +#ifndef _IRQ_RISCV_IMSIC_STATE_H
> > +#define _IRQ_RISCV_IMSIC_STATE_H
> > +
> > +#include <linux/irqchip/riscv-imsic.h>
> > +#include <linux/irqdomain.h>
> > +#include <linux/fwnode.h>
> > +
> > +struct imsic_priv {
> > +     /* Device details */
> > +     struct fwnode_handle *fwnode;
> > +
> > +     /* Global configuration common for all HARTs */
> > +     struct imsic_global_config global;
> > +
> > +     /* Global state of interrupt identities */
> > +     raw_spinlock_t ids_lock;
> > +     unsigned long *ids_used_bimap;
> > +     unsigned long *ids_enabled_bimap;
> > +     unsigned int *ids_target_cpu;
> > +
> > +     /* IPI interrupt identity and synchronization */
> > +     u32 ipi_id;
> > +     int ipi_virq;
> > +     struct irq_desc *ipi_lsync_desc;
> > +
> > +     /* IRQ domains (created by platform driver) */
> > +     struct irq_domain *base_domain;
> > +     struct irq_domain *plat_domain;
> > +};
> > +
> > +extern struct imsic_priv *imsic;
> > +
> > +void __imsic_eix_update(unsigned long base_id,
> > +                     unsigned long num_id, bool pend, bool val);
> > +
> > +#define __imsic_id_enable(__id)              \
> > +     __imsic_eix_update((__id), 1, false, true)
> > +#define __imsic_id_disable(__id)     \
> > +     __imsic_eix_update((__id), 1, false, false)
> > +
> > +void imsic_id_set_target(unsigned int id, unsigned int target_cpu);
> > +unsigned int imsic_id_get_target(unsigned int id);
> > +
> > +void imsic_ids_local_sync(void);
> > +void imsic_ids_local_delivery(bool enable);
> > +
> > +#ifdef CONFIG_SMP
> > +void imsic_ids_remote_sync(void);
> > +#else
> > +static inline void imsic_ids_remote_sync(void)
> > +{
> > +}
> > +#endif
> > +
> > +int imsic_ids_alloc(unsigned int order);
> > +void imsic_ids_free(unsigned int base_id, unsigned int order);
> > +
> > +int imsic_setup_state(struct fwnode_handle *fwnode);
> > +
> > +#endif
> > diff --git a/include/linux/irqchip/riscv-imsic.h b/include/linux/irqchip/riscv-imsic.h
> > new file mode 100644
> > index 000000000000..1f6fc9a57218
> > --- /dev/null
> > +++ b/include/linux/irqchip/riscv-imsic.h
> > @@ -0,0 +1,86 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only */
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +#ifndef __LINUX_IRQCHIP_RISCV_IMSIC_H
> > +#define __LINUX_IRQCHIP_RISCV_IMSIC_H
> > +
> > +#include <linux/types.h>
> > +#include <asm/csr.h>
> > +
> > +#define IMSIC_MMIO_PAGE_SHIFT                12
> > +#define IMSIC_MMIO_PAGE_SZ           (1UL << IMSIC_MMIO_PAGE_SHIFT)
> > +#define IMSIC_MMIO_PAGE_LE           0x00
> > +#define IMSIC_MMIO_PAGE_BE           0x04
> > +
> > +#define IMSIC_MIN_ID                 63
> > +#define IMSIC_MAX_ID                 2048
> > +
> > +#define IMSIC_EIDELIVERY             0x70
> > +
> > +#define IMSIC_EITHRESHOLD            0x72
> > +
> > +#define IMSIC_EIP0                   0x80
> > +#define IMSIC_EIP63                  0xbf
> > +#define IMSIC_EIPx_BITS                      32
> > +
> > +#define IMSIC_EIE0                   0xc0
> > +#define IMSIC_EIE63                  0xff
> > +#define IMSIC_EIEx_BITS                      32
> > +
> > +#define IMSIC_FIRST                  IMSIC_EIDELIVERY
> > +#define IMSIC_LAST                   IMSIC_EIE63
> > +
> > +#define IMSIC_MMIO_SETIPNUM_LE               0x00
> > +#define IMSIC_MMIO_SETIPNUM_BE               0x04
> > +
> > +struct imsic_local_config {
> > +     phys_addr_t msi_pa;
> > +     void __iomem *msi_va;
> > +};
> > +
> > +struct imsic_global_config {
> > +     /*
> > +      * MSI Target Address Scheme
> > +      *
> > +      * XLEN-1                                                12     0
> > +      * |                                                     |     |
> > +      * -------------------------------------------------------------
> > +      * |xxxxxx|Group Index|xxxxxxxxxxx|HART Index|Guest Index|  0  |
> > +      * -------------------------------------------------------------
> > +      */
> > +
> > +     /* Bits representing Guest index, HART index, and Group index */
> > +     u32 guest_index_bits;
> > +     u32 hart_index_bits;
> > +     u32 group_index_bits;
> > +     u32 group_index_shift;
> > +
> > +     /* Global base address matching all target MSI addresses */
> > +     phys_addr_t base_addr;
> > +
> > +     /* Number of interrupt identities */
> > +     u32 nr_ids;
> > +
> > +     /* Number of guest interrupt identities */
> > +     u32 nr_guest_ids;
> > +
> > +     /* Per-CPU IMSIC addresses */
> > +     struct imsic_local_config __percpu *local;
> > +};
> > +
> > +#ifdef CONFIG_RISCV_IMSIC
> > +
> > +extern const struct imsic_global_config *imsic_get_global_config(void);
> > +
> > +#else
> > +
> > +static inline const struct imsic_global_config *imsic_get_global_config(void)
> > +{
> > +     return NULL;
> > +}
> > +
> > +#endif
> > +
> > +#endif
> > --
> > 2.34.1
> >
> >
> > _______________________________________________
> > linux-riscv mailing list
> > linux-riscv@lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-riscv

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Re: [PATCH v8 03/16] of: property: Add fw_devlink support for msi-parent

[Anup Patel]

On Wed, Sep 13, 2023 at 4:30 AM Saravana Kannan <saravanak@google.com> wrote:
>
> On Tue, Sep 12, 2023 at 10:50 AM Anup Patel <apatel@ventanamicro.com> wrote:
> >
> > This allows fw_devlink to create device links between consumers of
> > a MSI and the supplier of the MSI.
> >
> > Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> > ---
> >  drivers/of/property.c | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/of/property.c b/drivers/of/property.c
> > index cf8dacf3e3b8..758ea822e46d 100644
> > --- a/drivers/of/property.c
> > +++ b/drivers/of/property.c
> > @@ -1267,6 +1267,7 @@ DEFINE_SIMPLE_PROP(resets, "resets", "#reset-cells")
> >  DEFINE_SIMPLE_PROP(leds, "leds", NULL)
> >  DEFINE_SIMPLE_PROP(backlight, "backlight", NULL)
> >  DEFINE_SIMPLE_PROP(panel, "panel", NULL)
> > +DEFINE_SIMPLE_PROP(msi_parent, "msi-parent", "#msi-cells")
> >  DEFINE_SUFFIX_PROP(regulators, "-supply", NULL)
> >  DEFINE_SUFFIX_PROP(gpio, "-gpio", "#gpio-cells")
> >
> > @@ -1361,6 +1362,7 @@ static const struct supplier_bindings of_supplier_bindings[] = {
> >         { .parse_prop = parse_regulators, },
> >         { .parse_prop = parse_gpio, },
> >         { .parse_prop = parse_gpios, },
> > +       { .parse_prop = parse_msi_parent, },
>
> Please follow the same ordering here as the DEFINE_SIMPLE_PROP macros.
> So, this should come after the panel one.
>

Okay, I will update in the next revision.

Regards,
Anup

Re: [PATCH v8 03/16] of: property: Add fw_devlink support for msi-parent

[Anup Patel]

On Wed, Sep 13, 2023 at 4:30 AM Saravana Kannan <saravanak@google.com> wrote:
>
> On Tue, Sep 12, 2023 at 10:50 AM Anup Patel <apatel@ventanamicro.com> wrote:
> >
> > This allows fw_devlink to create device links between consumers of
> > a MSI and the supplier of the MSI.
> >
> > Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> > ---
> >  drivers/of/property.c | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/of/property.c b/drivers/of/property.c
> > index cf8dacf3e3b8..758ea822e46d 100644
> > --- a/drivers/of/property.c
> > +++ b/drivers/of/property.c
> > @@ -1267,6 +1267,7 @@ DEFINE_SIMPLE_PROP(resets, "resets", "#reset-cells")
> >  DEFINE_SIMPLE_PROP(leds, "leds", NULL)
> >  DEFINE_SIMPLE_PROP(backlight, "backlight", NULL)
> >  DEFINE_SIMPLE_PROP(panel, "panel", NULL)
> > +DEFINE_SIMPLE_PROP(msi_parent, "msi-parent", "#msi-cells")
> >  DEFINE_SUFFIX_PROP(regulators, "-supply", NULL)
> >  DEFINE_SUFFIX_PROP(gpio, "-gpio", "#gpio-cells")
> >
> > @@ -1361,6 +1362,7 @@ static const struct supplier_bindings of_supplier_bindings[] = {
> >         { .parse_prop = parse_regulators, },
> >         { .parse_prop = parse_gpio, },
> >         { .parse_prop = parse_gpios, },
> > +       { .parse_prop = parse_msi_parent, },
>
> Please follow the same ordering here as the DEFINE_SIMPLE_PROP macros.
> So, this should come after the panel one.
>

Okay, I will update in the next revision.

Regards,
Anup

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Re: [PATCH v8 01/16] RISC-V: Don't fail in riscv_of_parent_hartid() for disabled HARTs

[Atish Patra]

On Tue, Sep 12, 2023 at 10:50 AM Anup Patel <apatel@ventanamicro.com> wrote:
>
> The riscv_of_processor_hartid() used by riscv_of_parent_hartid() fails
> for HARTs disabled in the DT. This results in the following warning
> thrown by the RISC-V INTC driver for the E-core on SiFive boards:
>
> [    0.000000] riscv-intc: unable to find hart id for /cpus/cpu@0/interrupt-controller
>
> The riscv_of_parent_hartid() is only expected to read the hartid from
> the DT so we should directly call of_get_cpu_hwid() instead of calling
> riscv_of_processor_hartid().
>
> Fixes: ad635e723e17 ("riscv: cpu: Add 64bit hartid support on RV64")
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> ---
>  arch/riscv/kernel/cpu.c | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
> index c17dacb1141c..157ace8b262c 100644
> --- a/arch/riscv/kernel/cpu.c
> +++ b/arch/riscv/kernel/cpu.c
> @@ -125,13 +125,14 @@ int __init riscv_early_of_processor_hartid(struct device_node *node, unsigned lo
>   */
>  int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid)
>  {
> -       int rc;
> -
>         for (; node; node = node->parent) {
>                 if (of_device_is_compatible(node, "riscv")) {
> -                       rc = riscv_of_processor_hartid(node, hartid);
> -                       if (!rc)
> -                               return 0;
> +                       *hartid = (unsigned long)of_get_cpu_hwid(node, 0);
> +                       if (*hartid == ~0UL) {
> +                               pr_warn("Found CPU without hart ID\n");
> +                               return -ENODEV;
> +                       }
> +                       return 0;
>                 }
>         }
>
> --
> 2.34.1
>

LGTM.

Reviewed-by: Atish Patra <atishp@rivosinc.com>

-- 
Regards,
Atish

Re: [PATCH v8 01/16] RISC-V: Don't fail in riscv_of_parent_hartid() for disabled HARTs

[Atish Patra]

On Tue, Sep 12, 2023 at 10:50 AM Anup Patel <apatel@ventanamicro.com> wrote:
>
> The riscv_of_processor_hartid() used by riscv_of_parent_hartid() fails
> for HARTs disabled in the DT. This results in the following warning
> thrown by the RISC-V INTC driver for the E-core on SiFive boards:
>
> [    0.000000] riscv-intc: unable to find hart id for /cpus/cpu@0/interrupt-controller
>
> The riscv_of_parent_hartid() is only expected to read the hartid from
> the DT so we should directly call of_get_cpu_hwid() instead of calling
> riscv_of_processor_hartid().
>
> Fixes: ad635e723e17 ("riscv: cpu: Add 64bit hartid support on RV64")
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> ---
>  arch/riscv/kernel/cpu.c | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
> index c17dacb1141c..157ace8b262c 100644
> --- a/arch/riscv/kernel/cpu.c
> +++ b/arch/riscv/kernel/cpu.c
> @@ -125,13 +125,14 @@ int __init riscv_early_of_processor_hartid(struct device_node *node, unsigned lo
>   */
>  int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid)
>  {
> -       int rc;
> -
>         for (; node; node = node->parent) {
>                 if (of_device_is_compatible(node, "riscv")) {
> -                       rc = riscv_of_processor_hartid(node, hartid);
> -                       if (!rc)
> -                               return 0;
> +                       *hartid = (unsigned long)of_get_cpu_hwid(node, 0);
> +                       if (*hartid == ~0UL) {
> +                               pr_warn("Found CPU without hart ID\n");
> +                               return -ENODEV;
> +                       }
> +                       return 0;
>                 }
>         }
>
> --
> 2.34.1
>

LGTM.

Reviewed-by: Atish Patra <atishp@rivosinc.com>

-- 
Regards,
Atish

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Re: [PATCH v8 02/16] RISC-V: Add riscv_get_intc_hartid() function

[Atish Patra]

On Tue, Sep 12, 2023 at 10:50 AM Anup Patel <apatel@ventanamicro.com> wrote:
>
> We add a common riscv_get_intc_hartid() which help device drivers to
> get hartid of the HART associated with a INTC (i.e. local interrupt
> controller) fwnode. This new function is more generic compared to
> the existing riscv_of_parent_hartid() function hence we also replace
> use of riscv_of_parent_hartid() with riscv_get_intc_hartid().
>
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> ---
>  arch/riscv/include/asm/processor.h |  4 +++-
>  arch/riscv/kernel/cpu.c            | 13 ++++++++++++-
>  drivers/irqchip/irq-riscv-intc.c   |  2 +-
>  drivers/irqchip/irq-sifive-plic.c  |  3 ++-
>  4 files changed, 18 insertions(+), 4 deletions(-)
>
> diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
> index 3e23e1786d05..3ce64b3bea4e 100644
> --- a/arch/riscv/include/asm/processor.h
> +++ b/arch/riscv/include/asm/processor.h
> @@ -119,7 +119,9 @@ static inline void wait_for_interrupt(void)
>  struct device_node;
>  int riscv_of_processor_hartid(struct device_node *node, unsigned long *hartid);
>  int riscv_early_of_processor_hartid(struct device_node *node, unsigned long *hartid);
> -int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid);
> +
> +struct fwnode_handle;
> +int riscv_get_intc_hartid(struct fwnode_handle *node, unsigned long *hartid);
>
>  extern void riscv_fill_hwcap(void);
>  extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
> diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
> index 157ace8b262c..ee583eac3c5b 100644
> --- a/arch/riscv/kernel/cpu.c
> +++ b/arch/riscv/kernel/cpu.c
> @@ -123,7 +123,8 @@ int __init riscv_early_of_processor_hartid(struct device_node *node, unsigned lo
>   * To achieve this, we walk up the DT tree until we find an active
>   * RISC-V core (HART) node and extract the cpuid from it.
>   */
> -int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid)
> +static int riscv_of_parent_hartid(struct device_node *node,
> +                                 unsigned long *hartid)
>  {
>         for (; node; node = node->parent) {
>                 if (of_device_is_compatible(node, "riscv")) {
> @@ -139,6 +140,16 @@ int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid)
>         return -1;
>  }
>
> +/* Find hart ID of the INTC fwnode. */
> +int riscv_get_intc_hartid(struct fwnode_handle *node, unsigned long *hartid)
> +{
> +       /* Extend this function ACPI in the future. */
> +       if (!is_of_node(node))
> +               return -ENODEV;
> +
> +       return riscv_of_parent_hartid(to_of_node(node), hartid);
> +}
> +
>  DEFINE_PER_CPU(struct riscv_cpuinfo, riscv_cpuinfo);
>
>  unsigned long riscv_cached_mvendorid(unsigned int cpu_id)
> diff --git a/drivers/irqchip/irq-riscv-intc.c b/drivers/irqchip/irq-riscv-intc.c
> index 4adeee1bc391..65f4a2afb381 100644
> --- a/drivers/irqchip/irq-riscv-intc.c
> +++ b/drivers/irqchip/irq-riscv-intc.c
> @@ -143,7 +143,7 @@ static int __init riscv_intc_init(struct device_node *node,
>         int rc;
>         unsigned long hartid;
>
> -       rc = riscv_of_parent_hartid(node, &hartid);
> +       rc = riscv_get_intc_hartid(of_fwnode_handle(node), &hartid);
>         if (rc < 0) {
>                 pr_warn("unable to find hart id for %pOF\n", node);
>                 return 0;
> diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
> index e1484905b7bd..56b0544b1f27 100644
> --- a/drivers/irqchip/irq-sifive-plic.c
> +++ b/drivers/irqchip/irq-sifive-plic.c
> @@ -477,7 +477,8 @@ static int __init __plic_init(struct device_node *node,
>                         continue;
>                 }
>
> -               error = riscv_of_parent_hartid(parent.np, &hartid);
> +               error = riscv_get_intc_hartid(of_fwnode_handle(parent.np),
> +                                             &hartid);
>                 if (error < 0) {
>                         pr_warn("failed to parse hart ID for context %d.\n", i);
>                         continue;
> --
> 2.34.1
>


Reviewed-by: Atish Patra <atishp@rivosinc.com>
-- 
Regards,
Atish

Re: [PATCH v8 02/16] RISC-V: Add riscv_get_intc_hartid() function

[Atish Patra]

On Tue, Sep 12, 2023 at 10:50 AM Anup Patel <apatel@ventanamicro.com> wrote:
>
> We add a common riscv_get_intc_hartid() which help device drivers to
> get hartid of the HART associated with a INTC (i.e. local interrupt
> controller) fwnode. This new function is more generic compared to
> the existing riscv_of_parent_hartid() function hence we also replace
> use of riscv_of_parent_hartid() with riscv_get_intc_hartid().
>
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> ---
>  arch/riscv/include/asm/processor.h |  4 +++-
>  arch/riscv/kernel/cpu.c            | 13 ++++++++++++-
>  drivers/irqchip/irq-riscv-intc.c   |  2 +-
>  drivers/irqchip/irq-sifive-plic.c  |  3 ++-
>  4 files changed, 18 insertions(+), 4 deletions(-)
>
> diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
> index 3e23e1786d05..3ce64b3bea4e 100644
> --- a/arch/riscv/include/asm/processor.h
> +++ b/arch/riscv/include/asm/processor.h
> @@ -119,7 +119,9 @@ static inline void wait_for_interrupt(void)
>  struct device_node;
>  int riscv_of_processor_hartid(struct device_node *node, unsigned long *hartid);
>  int riscv_early_of_processor_hartid(struct device_node *node, unsigned long *hartid);
> -int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid);
> +
> +struct fwnode_handle;
> +int riscv_get_intc_hartid(struct fwnode_handle *node, unsigned long *hartid);
>
>  extern void riscv_fill_hwcap(void);
>  extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
> diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
> index 157ace8b262c..ee583eac3c5b 100644
> --- a/arch/riscv/kernel/cpu.c
> +++ b/arch/riscv/kernel/cpu.c
> @@ -123,7 +123,8 @@ int __init riscv_early_of_processor_hartid(struct device_node *node, unsigned lo
>   * To achieve this, we walk up the DT tree until we find an active
>   * RISC-V core (HART) node and extract the cpuid from it.
>   */
> -int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid)
> +static int riscv_of_parent_hartid(struct device_node *node,
> +                                 unsigned long *hartid)
>  {
>         for (; node; node = node->parent) {
>                 if (of_device_is_compatible(node, "riscv")) {
> @@ -139,6 +140,16 @@ int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid)
>         return -1;
>  }
>
> +/* Find hart ID of the INTC fwnode. */
> +int riscv_get_intc_hartid(struct fwnode_handle *node, unsigned long *hartid)
> +{
> +       /* Extend this function ACPI in the future. */
> +       if (!is_of_node(node))
> +               return -ENODEV;
> +
> +       return riscv_of_parent_hartid(to_of_node(node), hartid);
> +}
> +
>  DEFINE_PER_CPU(struct riscv_cpuinfo, riscv_cpuinfo);
>
>  unsigned long riscv_cached_mvendorid(unsigned int cpu_id)
> diff --git a/drivers/irqchip/irq-riscv-intc.c b/drivers/irqchip/irq-riscv-intc.c
> index 4adeee1bc391..65f4a2afb381 100644
> --- a/drivers/irqchip/irq-riscv-intc.c
> +++ b/drivers/irqchip/irq-riscv-intc.c
> @@ -143,7 +143,7 @@ static int __init riscv_intc_init(struct device_node *node,
>         int rc;
>         unsigned long hartid;
>
> -       rc = riscv_of_parent_hartid(node, &hartid);
> +       rc = riscv_get_intc_hartid(of_fwnode_handle(node), &hartid);
>         if (rc < 0) {
>                 pr_warn("unable to find hart id for %pOF\n", node);
>                 return 0;
> diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
> index e1484905b7bd..56b0544b1f27 100644
> --- a/drivers/irqchip/irq-sifive-plic.c
> +++ b/drivers/irqchip/irq-sifive-plic.c
> @@ -477,7 +477,8 @@ static int __init __plic_init(struct device_node *node,
>                         continue;
>                 }
>
> -               error = riscv_of_parent_hartid(parent.np, &hartid);
> +               error = riscv_get_intc_hartid(of_fwnode_handle(parent.np),
> +                                             &hartid);
>                 if (error < 0) {
>                         pr_warn("failed to parse hart ID for context %d.\n", i);
>                         continue;
> --
> 2.34.1
>


Reviewed-by: Atish Patra <atishp@rivosinc.com>
-- 
Regards,
Atish

_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

Re: [PATCH v8 02/16] RISC-V: Add riscv_get_intc_hartid() function

[Sunil V L]

Hi Anup,

On Tue, Sep 12, 2023 at 11:19:14PM +0530, Anup Patel wrote:
> We add a common riscv_get_intc_hartid() which help device drivers to
> get hartid of the HART associated with a INTC (i.e. local interrupt
> controller) fwnode. This new function is more generic compared to
> the existing riscv_of_parent_hartid() function hence we also replace
> use of riscv_of_parent_hartid() with riscv_get_intc_hartid().
> 
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> ---
>  arch/riscv/include/asm/processor.h |  4 +++-
>  arch/riscv/kernel/cpu.c            | 13 ++++++++++++-
>  drivers/irqchip/irq-riscv-intc.c   |  2 +-
>  drivers/irqchip/irq-sifive-plic.c  |  3 ++-
>  4 files changed, 18 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
> index 3e23e1786d05..3ce64b3bea4e 100644
> --- a/arch/riscv/include/asm/processor.h
> +++ b/arch/riscv/include/asm/processor.h
> @@ -119,7 +119,9 @@ static inline void wait_for_interrupt(void)
>  struct device_node;
>  int riscv_of_processor_hartid(struct device_node *node, unsigned long *hartid);
>  int riscv_early_of_processor_hartid(struct device_node *node, unsigned long *hartid);
> -int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid);
> +
> +struct fwnode_handle;
> +int riscv_get_intc_hartid(struct fwnode_handle *node, unsigned long *hartid);
>  
>  extern void riscv_fill_hwcap(void);
>  extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
> diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
> index 157ace8b262c..ee583eac3c5b 100644
> --- a/arch/riscv/kernel/cpu.c
> +++ b/arch/riscv/kernel/cpu.c
> @@ -123,7 +123,8 @@ int __init riscv_early_of_processor_hartid(struct device_node *node, unsigned lo
>   * To achieve this, we walk up the DT tree until we find an active
>   * RISC-V core (HART) node and extract the cpuid from it.
>   */
> -int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid)
> +static int riscv_of_parent_hartid(struct device_node *node,
> +				  unsigned long *hartid)
>  {
>  	for (; node; node = node->parent) {
>  		if (of_device_is_compatible(node, "riscv")) {
> @@ -139,6 +140,16 @@ int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid)
>  	return -1;
>  }
>  
> +/* Find hart ID of the INTC fwnode. */
> +int riscv_get_intc_hartid(struct fwnode_handle *node, unsigned long *hartid)
> +{
> +	/* Extend this function ACPI in the future. */

As per Marc's feedback, we can't use swnode for ACPI irchips. So, there
is no need to create this wrapper function and this patch can be
dropped.

Thanks,
Sunil

> +	if (!is_of_node(node))
> +		return -ENODEV;
> +
> +	return riscv_of_parent_hartid(to_of_node(node), hartid);
> +}
> +
>  DEFINE_PER_CPU(struct riscv_cpuinfo, riscv_cpuinfo);
>  
>  unsigned long riscv_cached_mvendorid(unsigned int cpu_id)
> diff --git a/drivers/irqchip/irq-riscv-intc.c b/drivers/irqchip/irq-riscv-intc.c
> index 4adeee1bc391..65f4a2afb381 100644
> --- a/drivers/irqchip/irq-riscv-intc.c
> +++ b/drivers/irqchip/irq-riscv-intc.c
> @@ -143,7 +143,7 @@ static int __init riscv_intc_init(struct device_node *node,
>  	int rc;
>  	unsigned long hartid;
>  
> -	rc = riscv_of_parent_hartid(node, &hartid);
> +	rc = riscv_get_intc_hartid(of_fwnode_handle(node), &hartid);
>  	if (rc < 0) {
>  		pr_warn("unable to find hart id for %pOF\n", node);
>  		return 0;
> diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
> index e1484905b7bd..56b0544b1f27 100644
> --- a/drivers/irqchip/irq-sifive-plic.c
> +++ b/drivers/irqchip/irq-sifive-plic.c
> @@ -477,7 +477,8 @@ static int __init __plic_init(struct device_node *node,
>  			continue;
>  		}
>  
> -		error = riscv_of_parent_hartid(parent.np, &hartid);
> +		error = riscv_get_intc_hartid(of_fwnode_handle(parent.np),
> +					      &hartid);
>  		if (error < 0) {
>  			pr_warn("failed to parse hart ID for context %d.\n", i);
>  			continue;
> -- 
> 2.34.1
> 

Re: [PATCH v8 02/16] RISC-V: Add riscv_get_intc_hartid() function

[Sunil V L]

Hi Anup,

On Tue, Sep 12, 2023 at 11:19:14PM +0530, Anup Patel wrote:
> We add a common riscv_get_intc_hartid() which help device drivers to
> get hartid of the HART associated with a INTC (i.e. local interrupt
> controller) fwnode. This new function is more generic compared to
> the existing riscv_of_parent_hartid() function hence we also replace
> use of riscv_of_parent_hartid() with riscv_get_intc_hartid().
> 
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> ---
>  arch/riscv/include/asm/processor.h |  4 +++-
>  arch/riscv/kernel/cpu.c            | 13 ++++++++++++-
>  drivers/irqchip/irq-riscv-intc.c   |  2 +-
>  drivers/irqchip/irq-sifive-plic.c  |  3 ++-
>  4 files changed, 18 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
> index 3e23e1786d05..3ce64b3bea4e 100644
> --- a/arch/riscv/include/asm/processor.h
> +++ b/arch/riscv/include/asm/processor.h
> @@ -119,7 +119,9 @@ static inline void wait_for_interrupt(void)
>  struct device_node;
>  int riscv_of_processor_hartid(struct device_node *node, unsigned long *hartid);
>  int riscv_early_of_processor_hartid(struct device_node *node, unsigned long *hartid);
> -int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid);
> +
> +struct fwnode_handle;
> +int riscv_get_intc_hartid(struct fwnode_handle *node, unsigned long *hartid);
>  
>  extern void riscv_fill_hwcap(void);
>  extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
> diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
> index 157ace8b262c..ee583eac3c5b 100644
> --- a/arch/riscv/kernel/cpu.c
> +++ b/arch/riscv/kernel/cpu.c
> @@ -123,7 +123,8 @@ int __init riscv_early_of_processor_hartid(struct device_node *node, unsigned lo
>   * To achieve this, we walk up the DT tree until we find an active
>   * RISC-V core (HART) node and extract the cpuid from it.
>   */
> -int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid)
> +static int riscv_of_parent_hartid(struct device_node *node,
> +				  unsigned long *hartid)
>  {
>  	for (; node; node = node->parent) {
>  		if (of_device_is_compatible(node, "riscv")) {
> @@ -139,6 +140,16 @@ int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid)
>  	return -1;
>  }
>  
> +/* Find hart ID of the INTC fwnode. */
> +int riscv_get_intc_hartid(struct fwnode_handle *node, unsigned long *hartid)
> +{
> +	/* Extend this function ACPI in the future. */

As per Marc's feedback, we can't use swnode for ACPI irchips. So, there
is no need to create this wrapper function and this patch can be
dropped.

Thanks,
Sunil

> +	if (!is_of_node(node))
> +		return -ENODEV;
> +
> +	return riscv_of_parent_hartid(to_of_node(node), hartid);
> +}
> +
>  DEFINE_PER_CPU(struct riscv_cpuinfo, riscv_cpuinfo);
>  
>  unsigned long riscv_cached_mvendorid(unsigned int cpu_id)
> diff --git a/drivers/irqchip/irq-riscv-intc.c b/drivers/irqchip/irq-riscv-intc.c
> index 4adeee1bc391..65f4a2afb381 100644
> --- a/drivers/irqchip/irq-riscv-intc.c
> +++ b/drivers/irqchip/irq-riscv-intc.c
> @@ -143,7 +143,7 @@ static int __init riscv_intc_init(struct device_node *node,
>  	int rc;
>  	unsigned long hartid;
>  
> -	rc = riscv_of_parent_hartid(node, &hartid);
> +	rc = riscv_get_intc_hartid(of_fwnode_handle(node), &hartid);
>  	if (rc < 0) {
>  		pr_warn("unable to find hart id for %pOF\n", node);
>  		return 0;
> diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
> index e1484905b7bd..56b0544b1f27 100644
> --- a/drivers/irqchip/irq-sifive-plic.c
> +++ b/drivers/irqchip/irq-sifive-plic.c
> @@ -477,7 +477,8 @@ static int __init __plic_init(struct device_node *node,
>  			continue;
>  		}
>  
> -		error = riscv_of_parent_hartid(parent.np, &hartid);
> +		error = riscv_get_intc_hartid(of_fwnode_handle(parent.np),
> +					      &hartid);
>  		if (error < 0) {
>  			pr_warn("failed to parse hart ID for context %d.\n", i);
>  			continue;
> -- 
> 2.34.1
> 

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Re: [PATCH v8 09/16] irqchip: Add RISC-V incoming MSI controller early driver

[Sunil V L]

Hi Anup,

On Tue, Sep 12, 2023 at 11:19:21PM +0530, Anup Patel wrote:
> The RISC-V advanced interrupt architecture (AIA) specification
> defines a new MSI controller called incoming message signalled
> interrupt controller (IMSIC) which manages MSI on per-HART (or
> per-CPU) basis. It also supports IPIs as software injected MSIs.
> (For more details refer https://github.com/riscv/riscv-aia)
> 
> Let us add an early irqchip driver for RISC-V IMSIC which sets
> up the IMSIC state and provide IPIs.
> 
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> ---
>  drivers/irqchip/Kconfig                 |   7 +-
>  drivers/irqchip/Makefile                |   1 +
>  drivers/irqchip/irq-riscv-imsic-early.c | 258 ++++++++++++
>  drivers/irqchip/irq-riscv-imsic-state.c | 523 ++++++++++++++++++++++++
>  drivers/irqchip/irq-riscv-imsic-state.h |  66 +++
>  include/linux/irqchip/riscv-imsic.h     |  86 ++++
>  6 files changed, 940 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/irqchip/irq-riscv-imsic-early.c
>  create mode 100644 drivers/irqchip/irq-riscv-imsic-state.c
>  create mode 100644 drivers/irqchip/irq-riscv-imsic-state.h
>  create mode 100644 include/linux/irqchip/riscv-imsic.h
> 
> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> index f7149d0f3d45..ee99aacbefcc 100644
> --- a/drivers/irqchip/Kconfig
> +++ b/drivers/irqchip/Kconfig
> @@ -30,7 +30,6 @@ config ARM_GIC_V2M
>  
>  config GIC_NON_BANKED
>  	bool
> -
>  config ARM_GIC_V3
>  	bool
>  	select IRQ_DOMAIN_HIERARCHY
> @@ -546,6 +545,12 @@ config SIFIVE_PLIC
>  	select IRQ_DOMAIN_HIERARCHY
>  	select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
>  
> +config RISCV_IMSIC
> +	bool
> +	depends on RISCV
> +	select IRQ_DOMAIN_HIERARCHY
> +	select GENERIC_MSI_IRQ
> +
>  config EXYNOS_IRQ_COMBINER
>  	bool "Samsung Exynos IRQ combiner support" if COMPILE_TEST
>  	depends on (ARCH_EXYNOS && ARM) || COMPILE_TEST
> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index ffd945fe71aa..d714724387ce 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -95,6 +95,7 @@ obj-$(CONFIG_QCOM_MPM)			+= irq-qcom-mpm.o
>  obj-$(CONFIG_CSKY_MPINTC)		+= irq-csky-mpintc.o
>  obj-$(CONFIG_CSKY_APB_INTC)		+= irq-csky-apb-intc.o
>  obj-$(CONFIG_RISCV_INTC)		+= irq-riscv-intc.o
> +obj-$(CONFIG_RISCV_IMSIC)		+= irq-riscv-imsic-state.o irq-riscv-imsic-early.o
>  obj-$(CONFIG_SIFIVE_PLIC)		+= irq-sifive-plic.o
>  obj-$(CONFIG_IMX_IRQSTEER)		+= irq-imx-irqsteer.o
>  obj-$(CONFIG_IMX_INTMUX)		+= irq-imx-intmux.o
> diff --git a/drivers/irqchip/irq-riscv-imsic-early.c b/drivers/irqchip/irq-riscv-imsic-early.c
> new file mode 100644
> index 000000000000..1de89ce1ec2f
> --- /dev/null
> +++ b/drivers/irqchip/irq-riscv-imsic-early.c
> @@ -0,0 +1,258 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> + * Copyright (C) 2022 Ventana Micro Systems Inc.
> + */
> +
> +#define pr_fmt(fmt) "riscv-imsic: " fmt
> +#include <linux/cpu.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/irq.h>
> +#include <linux/irqchip.h>
> +#include <linux/irqchip/chained_irq.h>
> +#include <linux/module.h>
> +#include <linux/spinlock.h>
> +#include <linux/smp.h>
> +
> +#include "irq-riscv-imsic-state.h"
> +
> +/*
> + * The IMSIC driver uses 1 IPI for ID synchronization and
> + * arch/riscv/kernel/smp.c require 6 IPIs so we fix the
> + * total number of IPIs to 8.
> + */
> +#define IMSIC_NR_IPI				8
> +
> +static int imsic_parent_irq;
> +
> +#ifdef CONFIG_SMP
> +static irqreturn_t imsic_ids_sync_handler(int irq, void *data)
> +{
> +	imsic_ids_local_sync();
> +	return IRQ_HANDLED;
> +}
> +
> +void imsic_ids_remote_sync(void)
> +{
> +	struct cpumask amask;
> +
> +	/*
> +	 * We simply inject ID synchronization IPI to all target CPUs
> +	 * except current CPU. The ipi_send_mask() implementation of
> +	 * IPI mux will inject ID synchronization IPI only for CPUs
> +	 * that have enabled it so offline CPUs won't receive IPI.
> +	 * An offline CPU will unconditionally synchronize IDs through
> +	 * imsic_starting_cpu() when the CPU is brought up.
> +	 */
> +	cpumask_andnot(&amask, cpu_online_mask, cpumask_of(smp_processor_id()));
> +	__ipi_send_mask(imsic->ipi_lsync_desc, &amask);
> +}
> +
> +static void imsic_ipi_send(unsigned int cpu)
> +{
> +	struct imsic_local_config *local =
> +				per_cpu_ptr(imsic->global.local, cpu);
> +
> +	writel(imsic->ipi_id, local->msi_va);
> +}
> +
> +static void imsic_ipi_starting_cpu(void)
> +{
> +	/* Enable IPIs for current CPU. */
> +	__imsic_id_enable(imsic->ipi_id);
> +
> +	/* Enable virtual IPI used for IMSIC ID synchronization */
> +	enable_percpu_irq(imsic->ipi_virq, 0);
> +}
> +
> +static void imsic_ipi_dying_cpu(void)
> +{
> +	/*
> +	 * Disable virtual IPI used for IMSIC ID synchronization so
> +	 * that we don't receive ID synchronization requests.
> +	 */
> +	disable_percpu_irq(imsic->ipi_virq);
> +}
> +
> +static int __init imsic_ipi_domain_init(void)
> +{
> +	int virq;
> +
> +	/* Allocate interrupt identity for IPIs */
> +	virq = imsic_ids_alloc(get_count_order(1));
> +	if (virq < 0)
> +		return virq;
> +	imsic->ipi_id = virq;
> +
> +	/* Create IMSIC IPI multiplexing */
> +	virq = ipi_mux_create(IMSIC_NR_IPI, imsic_ipi_send);
> +	if (virq <= 0) {
> +		imsic_ids_free(imsic->ipi_id, get_count_order(1));
> +		return (virq < 0) ? virq : -ENOMEM;
> +	}
> +	imsic->ipi_virq = virq;
> +
> +	/* First vIRQ is used for IMSIC ID synchronization */
> +	virq = request_percpu_irq(imsic->ipi_virq, imsic_ids_sync_handler,
> +				  "riscv-imsic-lsync", imsic->global.local);
> +	if (virq) {
> +		imsic_ids_free(imsic->ipi_id, get_count_order(1));
> +		return virq;
> +	}
> +	irq_set_status_flags(imsic->ipi_virq, IRQ_HIDDEN);
> +	imsic->ipi_lsync_desc = irq_to_desc(imsic->ipi_virq);
> +
> +	/* Set vIRQ range */
> +	riscv_ipi_set_virq_range(imsic->ipi_virq + 1, IMSIC_NR_IPI - 1, true);
> +
> +	/* Announce that IMSIC is providing IPIs */
> +	pr_info("%pfwP: providing IPIs using interrupt %d\n",
> +		imsic->fwnode, imsic->ipi_id);
> +
> +	return 0;
> +}
> +#else
> +static void imsic_ipi_starting_cpu(void)
> +{
> +}
> +
> +static void imsic_ipi_dying_cpu(void)
> +{
> +}
> +
> +static int __init imsic_ipi_domain_init(void)
> +{
> +	/* Clear the IPI id because we are not using IPIs */
> +	imsic->ipi_id = 0;
> +	return 0;
> +}
> +#endif
> +
> +/*
> + * To handle an interrupt, we read the TOPEI CSR and write zero in one
> + * instruction. If TOPEI CSR is non-zero then we translate TOPEI.ID to
> + * Linux interrupt number and let Linux IRQ subsystem handle it.
> + */
> +static void imsic_handle_irq(struct irq_desc *desc)
> +{
> +	struct irq_chip *chip = irq_desc_get_chip(desc);
> +	irq_hw_number_t hwirq;
> +	int err;
> +
> +	chained_irq_enter(chip, desc);
> +
> +	while ((hwirq = csr_swap(CSR_TOPEI, 0))) {
> +		hwirq = hwirq >> TOPEI_ID_SHIFT;
> +
> +		if (hwirq == imsic->ipi_id) {
> +#ifdef CONFIG_SMP
> +			ipi_mux_process();
> +#endif
> +			continue;
> +		}
> +
> +		if (unlikely(!imsic->base_domain))
> +			continue;
> +
> +		err = generic_handle_domain_irq(imsic->base_domain, hwirq);
> +		if (unlikely(err))
> +			pr_warn_ratelimited(
> +				"hwirq %lu mapping not found\n", hwirq);
> +	}
> +
> +	chained_irq_exit(chip, desc);
> +}
> +
> +static int imsic_starting_cpu(unsigned int cpu)
> +{
> +	/* Enable per-CPU parent interrupt */
> +	enable_percpu_irq(imsic_parent_irq,
> +			  irq_get_trigger_type(imsic_parent_irq));
> +
> +	/* Setup IPIs */
> +	imsic_ipi_starting_cpu();
> +
> +	/*
> +	 * Interrupts identities might have been enabled/disabled while
> +	 * this CPU was not running so sync-up local enable/disable state.
> +	 */
> +	imsic_ids_local_sync();
> +
> +	/* Enable local interrupt delivery */
> +	imsic_ids_local_delivery(true);
> +
> +	return 0;
> +}
> +
> +static int imsic_dying_cpu(unsigned int cpu)
> +{
> +	/* Cleanup IPIs */
> +	imsic_ipi_dying_cpu();
> +
> +	return 0;
> +}
> +
> +static int __init imsic_early_probe(struct fwnode_handle *fwnode)

Can this imsic_early_probe() take an additional pointer as parameter?
This parameter can be NULL for DT and we can use to pass the MADT
structure in case of ACPI since fwnode in ACPI will not have any
properties. The parameter needs to be passed to imsic_setup_state()
also.

> +{
> +	int rc;
> +	struct irq_domain *domain;
> +
> +	/* Setup IMSIC state */
> +	rc = imsic_setup_state(fwnode);
> +	if (rc) {
> +		pr_err("%pfwP: failed to setup state (error %d)\n",
> +			fwnode, rc);
> +		return rc;
> +	}
> +
> +	/* Find parent domain and register chained handler */
> +	domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
> +					  DOMAIN_BUS_ANY);
> +	if (!domain) {
> +		pr_err("%pfwP: Failed to find INTC domain\n", fwnode);
> +		return -ENOENT;
> +	}
> +	imsic_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT);
> +	if (!imsic_parent_irq) {
> +		pr_err("%pfwP: Failed to create INTC mapping\n", fwnode);
> +		return -ENOENT;
> +	}
> +	irq_set_chained_handler(imsic_parent_irq, imsic_handle_irq);
> +
> +	/* Initialize IPI domain */
> +	rc = imsic_ipi_domain_init();
> +	if (rc) {
> +		pr_err("%pfwP: Failed to initialize IPI domain\n", fwnode);
> +		return rc;
> +	}
> +
> +	/*
> +	 * Setup cpuhp state (must be done after setting imsic_parent_irq)
> +	 *
> +	 * Don't disable per-CPU IMSIC file when CPU goes offline
> +	 * because this affects IPI and the masking/unmasking of
> +	 * virtual IPIs is done via generic IPI-Mux
> +	 */
> +	cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
> +			  "irqchip/riscv/imsic:starting",
> +			  imsic_starting_cpu, imsic_dying_cpu);
> +
> +	return 0;
> +}
> +
> +static int __init imsic_early_dt_init(struct device_node *node,
> +				      struct device_node *parent)
> +{
> +	int rc;
> +
> +	/* Do early setup of IMSIC state and IPIs */
> +	rc = imsic_early_probe(&node->fwnode);
> +	if (rc)
> +		return rc;
> +
> +	/* Ensure that OF platform device gets probed */
> +	of_node_clear_flag(node, OF_POPULATED);
> +	return 0;
> +}
> +IRQCHIP_DECLARE(riscv_imsic, "riscv,imsics", imsic_early_dt_init);
> diff --git a/drivers/irqchip/irq-riscv-imsic-state.c b/drivers/irqchip/irq-riscv-imsic-state.c
> new file mode 100644
> index 000000000000..412b5b919dcc
> --- /dev/null
> +++ b/drivers/irqchip/irq-riscv-imsic-state.c
> @@ -0,0 +1,523 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> + * Copyright (C) 2022 Ventana Micro Systems Inc.
> + */
> +
> +#define pr_fmt(fmt) "riscv-imsic: " fmt
> +#include <linux/bitmap.h>
> +#include <linux/module.h>
> +#include <linux/of_address.h>
> +#include <linux/spinlock.h>
> +#include <linux/smp.h>
> +#include <asm/hwcap.h>
> +
> +#include "irq-riscv-imsic-state.h"
> +
> +#define IMSIC_DISABLE_EIDELIVERY		0
> +#define IMSIC_ENABLE_EIDELIVERY			1
> +#define IMSIC_DISABLE_EITHRESHOLD		1
> +#define IMSIC_ENABLE_EITHRESHOLD		0
> +
> +#define imsic_csr_write(__c, __v)		\
> +do {						\
> +	csr_write(CSR_ISELECT, __c);		\
> +	csr_write(CSR_IREG, __v);		\
> +} while (0)
> +
> +#define imsic_csr_read(__c)			\
> +({						\
> +	unsigned long __v;			\
> +	csr_write(CSR_ISELECT, __c);		\
> +	__v = csr_read(CSR_IREG);		\
> +	__v;					\
> +})
> +
> +#define imsic_csr_set(__c, __v)			\
> +do {						\
> +	csr_write(CSR_ISELECT, __c);		\
> +	csr_set(CSR_IREG, __v);			\
> +} while (0)
> +
> +#define imsic_csr_clear(__c, __v)		\
> +do {						\
> +	csr_write(CSR_ISELECT, __c);		\
> +	csr_clear(CSR_IREG, __v);		\
> +} while (0)
> +
> +struct imsic_priv *imsic;
> +
> +const struct imsic_global_config *imsic_get_global_config(void)
> +{
> +	return (imsic) ? &imsic->global : NULL;
> +}
> +EXPORT_SYMBOL_GPL(imsic_get_global_config);
> +
> +void __imsic_eix_update(unsigned long base_id,
> +			unsigned long num_id, bool pend, bool val)
> +{
> +	unsigned long i, isel, ireg;
> +	unsigned long id = base_id, last_id = base_id + num_id;
> +
> +	while (id < last_id) {
> +		isel = id / BITS_PER_LONG;
> +		isel *= BITS_PER_LONG / IMSIC_EIPx_BITS;
> +		isel += (pend) ? IMSIC_EIP0 : IMSIC_EIE0;
> +
> +		ireg = 0;
> +		for (i = id & (__riscv_xlen - 1);
> +		     (id < last_id) && (i < __riscv_xlen); i++) {
> +			ireg |= BIT(i);
> +			id++;
> +		}
> +
> +		/*
> +		 * The IMSIC EIEx and EIPx registers are indirectly
> +		 * accessed via using ISELECT and IREG CSRs so we
> +		 * need to access these CSRs without getting preempted.
> +		 *
> +		 * All existing users of this function call this
> +		 * function with local IRQs disabled so we don't
> +		 * need to do anything special here.
> +		 */
> +		if (val)
> +			imsic_csr_set(isel, ireg);
> +		else
> +			imsic_csr_clear(isel, ireg);
> +	}
> +}
> +
> +void imsic_id_set_target(unsigned int id, unsigned int target_cpu)
> +{
> +	unsigned long flags;
> +
> +	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> +	imsic->ids_target_cpu[id] = target_cpu;
> +	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> +}
> +
> +unsigned int imsic_id_get_target(unsigned int id)
> +{
> +	unsigned int ret;
> +	unsigned long flags;
> +
> +	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> +	ret = imsic->ids_target_cpu[id];
> +	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> +
> +	return ret;
> +}
> +
> +void imsic_ids_local_sync(void)
> +{
> +	int i;
> +	unsigned long flags;
> +
> +	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> +	for (i = 1; i <= imsic->global.nr_ids; i++) {
> +		if (imsic->ipi_id == i)
> +			continue;
> +
> +		if (test_bit(i, imsic->ids_enabled_bimap))
> +			__imsic_id_enable(i);
> +		else
> +			__imsic_id_disable(i);
> +	}
> +	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> +}
> +
> +void imsic_ids_local_delivery(bool enable)
> +{
> +	if (enable) {
> +		imsic_csr_write(IMSIC_EITHRESHOLD, IMSIC_ENABLE_EITHRESHOLD);
> +		imsic_csr_write(IMSIC_EIDELIVERY, IMSIC_ENABLE_EIDELIVERY);
> +	} else {
> +		imsic_csr_write(IMSIC_EIDELIVERY, IMSIC_DISABLE_EIDELIVERY);
> +		imsic_csr_write(IMSIC_EITHRESHOLD, IMSIC_DISABLE_EITHRESHOLD);
> +	}
> +}
> +
> +int imsic_ids_alloc(unsigned int order)
> +{
> +	int ret;
> +	unsigned long flags;
> +
> +	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> +	ret = bitmap_find_free_region(imsic->ids_used_bimap,
> +				      imsic->global.nr_ids + 1, order);
> +	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> +
> +	return ret;
> +}
> +
> +void imsic_ids_free(unsigned int base_id, unsigned int order)
> +{
> +	unsigned long flags;
> +
> +	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> +	bitmap_release_region(imsic->ids_used_bimap, base_id, order);
> +	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> +}
> +
> +static int __init imsic_ids_init(void)
> +{
> +	int i;
> +	struct imsic_global_config *global = &imsic->global;
> +
> +	raw_spin_lock_init(&imsic->ids_lock);
> +
> +	/* Allocate used bitmap */
> +	imsic->ids_used_bimap = bitmap_zalloc(global->nr_ids + 1, GFP_KERNEL);
> +	if (!imsic->ids_used_bimap)
> +		return -ENOMEM;
> +
> +	/* Allocate enabled bitmap */
> +	imsic->ids_enabled_bimap = bitmap_zalloc(global->nr_ids + 1,
> +						GFP_KERNEL);
> +	if (!imsic->ids_enabled_bimap) {
> +		kfree(imsic->ids_used_bimap);
> +		return -ENOMEM;
> +	}
> +
> +	/* Allocate target CPU array */
> +	imsic->ids_target_cpu = kcalloc(global->nr_ids + 1,
> +				       sizeof(unsigned int), GFP_KERNEL);
> +	if (!imsic->ids_target_cpu) {
> +		bitmap_free(imsic->ids_enabled_bimap);
> +		bitmap_free(imsic->ids_used_bimap);
> +		return -ENOMEM;
> +	}
> +	for (i = 0; i <= global->nr_ids; i++)
> +		imsic->ids_target_cpu[i] = UINT_MAX;
> +
> +	/* Reserve ID#0 because it is special and never implemented */
> +	bitmap_set(imsic->ids_used_bimap, 0, 1);
> +
> +	return 0;
> +}
> +
> +static void __init imsic_ids_cleanup(void)
> +{
> +	kfree(imsic->ids_target_cpu);
> +	bitmap_free(imsic->ids_enabled_bimap);
> +	bitmap_free(imsic->ids_used_bimap);
> +}
> +
> +static int __init imsic_get_parent_hartid(struct fwnode_handle *fwnode,
> +					  u32 index, unsigned long *hartid)
> +{
> +	int rc;
> +	struct fwnode_reference_args parent;
> +
> +	rc = fwnode_property_get_reference_args(fwnode,
> +			"interrupts-extended", "#interrupt-cells",
> +			0, index, &parent);
> +	if (rc)
> +		return rc;
> +
> +	/*
> +	 * Skip interrupts other than external interrupts for
> +	 * current privilege level.
> +	 */
> +	if (parent.args[0] != RV_IRQ_EXT)
> +		return -EINVAL;
> +
> +	return riscv_get_intc_hartid(parent.fwnode, hartid);
> +}
> +
> +static int __init imsic_get_mmio_resource(struct fwnode_handle *fwnode,
> +					  u32 index, struct resource *res)
> +{
> +	/*
> +	 * Currently, only OF fwnode is support so extend this function
> +	 * for other types of fwnode for ACPI support.
> +	 */
> +	if (!is_of_node(fwnode))
> +		return -EINVAL;
> +	return of_address_to_resource(to_of_node(fwnode), index, res);
> +}
> +
> +int __init imsic_setup_state(struct fwnode_handle *fwnode)
> +{
> +	int rc, cpu;
> +	phys_addr_t base_addr;
> +	void __iomem **mmios_va = NULL;
> +	struct resource res, *mmios = NULL;
> +	struct imsic_local_config *local;
> +	struct imsic_global_config *global;
> +	unsigned long reloff, hartid;
> +	u32 i, j, index, nr_parent_irqs, nr_handlers = 0, num_mmios = 0;
> +
> +	/*
> +	 * Only one IMSIC instance allowed in a platform for clean
> +	 * implementation of SMP IRQ affinity and per-CPU IPIs.
> +	 *
> +	 * This means on a multi-socket (or multi-die) platform we
> +	 * will have multiple MMIO regions for one IMSIC instance.
> +	 */
> +	if (imsic) {
> +		pr_err("%pfwP: already initialized hence ignoring\n",
> +			fwnode);
> +		return -EALREADY;
> +	}
> +
> +	if (!riscv_isa_extension_available(NULL, SxAIA)) {
> +		pr_err("%pfwP: AIA support not available\n", fwnode);
> +		return -ENODEV;
> +	}
> +
> +	imsic = kzalloc(sizeof(*imsic), GFP_KERNEL);
> +	if (!imsic)
> +		return -ENOMEM;
> +	imsic->fwnode = fwnode;
> +	global = &imsic->global;
> +
> +	global->local = alloc_percpu(typeof(*(global->local)));
> +	if (!global->local) {
> +		rc = -ENOMEM;
> +		goto out_free_priv;
> +	}
> +
> +	/* Find number of parent interrupts */
> +	nr_parent_irqs = 0;
> +	while (!imsic_get_parent_hartid(fwnode, nr_parent_irqs, &hartid))
> +		nr_parent_irqs++;
> +	if (!nr_parent_irqs) {
> +		pr_err("%pfwP: no parent irqs available\n", fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +
> +	/* Find number of guest index bits in MSI address */
> +	rc = fwnode_property_read_u32_array(fwnode, "riscv,guest-index-bits",
> +					    &global->guest_index_bits, 1);
> +	if (rc)
> +		global->guest_index_bits = 0;
> +	i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT;
> +	if (i < global->guest_index_bits) {
> +		pr_err("%pfwP: guest index bits too big\n", fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +
> +	/* Find number of HART index bits */
> +	rc = fwnode_property_read_u32_array(fwnode, "riscv,hart-index-bits",
> +					    &global->hart_index_bits, 1);
> +	if (rc) {
> +		/* Assume default value */
> +		global->hart_index_bits = __fls(nr_parent_irqs);
> +		if (BIT(global->hart_index_bits) < nr_parent_irqs)
> +			global->hart_index_bits++;
> +	}
> +	i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT - global->guest_index_bits;
> +	if (i < global->hart_index_bits) {
> +		pr_err("%pfwP: HART index bits too big\n", fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +
> +	/* Find number of group index bits */
> +	rc = fwnode_property_read_u32_array(fwnode, "riscv,group-index-bits",
> +					    &global->group_index_bits, 1);
> +	if (rc)
> +		global->group_index_bits = 0;
> +	i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT -
> +	    global->guest_index_bits - global->hart_index_bits;
> +	if (i < global->group_index_bits) {
> +		pr_err("%pfwP: group index bits too big\n", fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +
> +	/*
> +	 * Find first bit position of group index.
> +	 * If not specified assumed the default APLIC-IMSIC configuration.
> +	 */
> +	rc = fwnode_property_read_u32_array(fwnode, "riscv,group-index-shift",
> +					    &global->group_index_shift, 1);
> +	if (rc)
> +		global->group_index_shift = IMSIC_MMIO_PAGE_SHIFT * 2;
> +	i = global->group_index_bits + global->group_index_shift - 1;
> +	if (i >= BITS_PER_LONG) {
> +		pr_err("%pfwP: group index shift too big\n", fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +
> +	/* Find number of interrupt identities */
> +	rc = fwnode_property_read_u32_array(fwnode, "riscv,num-ids",
> +					    &global->nr_ids, 1);
> +	if (rc) {
> +		pr_err("%pfwP: number of interrupt identities not found\n",
> +			fwnode);
> +		goto out_free_local;
> +	}
> +	if ((global->nr_ids < IMSIC_MIN_ID) ||
> +	    (global->nr_ids >= IMSIC_MAX_ID) ||
> +	    ((global->nr_ids & IMSIC_MIN_ID) != IMSIC_MIN_ID)) {
> +		pr_err("%pfwP: invalid number of interrupt identities\n",
> +			fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +
> +	/* Find number of guest interrupt identities */
> +	if (fwnode_property_read_u32_array(fwnode, "riscv,num-guest-ids",
> +					   &global->nr_guest_ids, 1))
> +		global->nr_guest_ids = global->nr_ids;
> +	if ((global->nr_guest_ids < IMSIC_MIN_ID) ||
> +	    (global->nr_guest_ids >= IMSIC_MAX_ID) ||
> +	    ((global->nr_guest_ids & IMSIC_MIN_ID) != IMSIC_MIN_ID)) {
> +		pr_err("%pfwP: invalid number of guest interrupt identities\n",
> +			fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +

Could you create a separate function for DT to fill up this
imsic_global structure? In case of ACPI, we can not get this data from
the fwnode and hence need to have separate function to fill up this
structure.

Thanks!
Sunil
> +	/* Compute base address */
> +	rc = imsic_get_mmio_resource(fwnode, 0, &res);
> +	if (rc) {
> +		pr_err("%pfwP: first MMIO resource not found\n", fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +	global->base_addr = res.start;
> +	global->base_addr &= ~(BIT(global->guest_index_bits +
> +				   global->hart_index_bits +
> +				   IMSIC_MMIO_PAGE_SHIFT) - 1);
> +	global->base_addr &= ~((BIT(global->group_index_bits) - 1) <<
> +			       global->group_index_shift);
> +
> +	/* Find number of MMIO register sets */
> +	while (!imsic_get_mmio_resource(fwnode, num_mmios, &res))
> +		num_mmios++;
> +
> +	/* Allocate MMIO resource array */
> +	mmios = kcalloc(num_mmios, sizeof(*mmios), GFP_KERNEL);
> +	if (!mmios) {
> +		rc = -ENOMEM;
> +		goto out_free_local;
> +	}
> +
> +	/* Allocate MMIO virtual address array */
> +	mmios_va = kcalloc(num_mmios, sizeof(*mmios_va), GFP_KERNEL);
> +	if (!mmios_va) {
> +		rc = -ENOMEM;
> +		goto out_iounmap;
> +	}
> +
> +	/* Parse and map MMIO register sets */
> +	for (i = 0; i < num_mmios; i++) {
> +		rc = imsic_get_mmio_resource(fwnode, i, &mmios[i]);
> +		if (rc) {
> +			pr_err("%pfwP: unable to parse MMIO regset %d\n",
> +				fwnode, i);
> +			goto out_iounmap;
> +		}
> +
> +		base_addr = mmios[i].start;
> +		base_addr &= ~(BIT(global->guest_index_bits +
> +				   global->hart_index_bits +
> +				   IMSIC_MMIO_PAGE_SHIFT) - 1);
> +		base_addr &= ~((BIT(global->group_index_bits) - 1) <<
> +			       global->group_index_shift);
> +		if (base_addr != global->base_addr) {
> +			rc = -EINVAL;
> +			pr_err("%pfwP: address mismatch for regset %d\n",
> +				fwnode, i);
> +			goto out_iounmap;
> +		}
> +
> +		mmios_va[i] = ioremap(mmios[i].start, resource_size(&mmios[i]));
> +		if (!mmios_va[i]) {
> +			rc = -EIO;
> +			pr_err("%pfwP: unable to map MMIO regset %d\n",
> +				fwnode, i);
> +			goto out_iounmap;
> +		}
> +	}
> +
> +	/* Initialize interrupt identity management */
> +	rc = imsic_ids_init();
> +	if (rc) {
> +		pr_err("%pfwP: failed to initialize interrupt management\n",
> +		       fwnode);
> +		goto out_iounmap;
> +	}
> +
> +	/* Configure handlers for target CPUs */
> +	for (i = 0; i < nr_parent_irqs; i++) {
> +		rc = imsic_get_parent_hartid(fwnode, i, &hartid);
> +		if (rc) {
> +			pr_warn("%pfwP: hart ID for parent irq%d not found\n",
> +				fwnode, i);
> +			continue;
> +		}
> +
> +		cpu = riscv_hartid_to_cpuid(hartid);
> +		if (cpu < 0) {
> +			pr_warn("%pfwP: invalid cpuid for parent irq%d\n",
> +				fwnode, i);
> +			continue;
> +		}
> +
> +		/* Find MMIO location of MSI page */
> +		index = num_mmios;
> +		reloff = i * BIT(global->guest_index_bits) *
> +			 IMSIC_MMIO_PAGE_SZ;
> +		for (j = 0; num_mmios; j++) {
> +			if (reloff < resource_size(&mmios[j])) {
> +				index = j;
> +				break;
> +			}
> +
> +			/*
> +			 * MMIO region size may not be aligned to
> +			 * BIT(global->guest_index_bits) * IMSIC_MMIO_PAGE_SZ
> +			 * if holes are present.
> +			 */
> +			reloff -= ALIGN(resource_size(&mmios[j]),
> +			BIT(global->guest_index_bits) * IMSIC_MMIO_PAGE_SZ);
> +		}
> +		if (index >= num_mmios) {
> +			pr_warn("%pfwP: MMIO not found for parent irq%d\n",
> +				fwnode, i);
> +			continue;
> +		}
> +
> +		local = per_cpu_ptr(global->local, cpu);
> +		local->msi_pa = mmios[index].start + reloff;
> +		local->msi_va = mmios_va[index] + reloff;
> +
> +		nr_handlers++;
> +	}
> +
> +	/* If no CPU handlers found then can't take interrupts */
> +	if (!nr_handlers) {
> +		pr_err("%pfwP: No CPU handlers found\n", fwnode);
> +		rc = -ENODEV;
> +		goto out_ids_cleanup;
> +	}
> +
> +	/* We don't need MMIO arrays anymore so let's free-up */
> +	kfree(mmios_va);
> +	kfree(mmios);
> +
> +	return 0;
> +
> +out_ids_cleanup:
> +	imsic_ids_cleanup();
> +out_iounmap:
> +	for (i = 0; i < num_mmios; i++) {
> +		if (mmios_va[i])
> +			iounmap(mmios_va[i]);
> +	}
> +	kfree(mmios_va);
> +	kfree(mmios);
> +out_free_local:
> +	free_percpu(imsic->global.local);
> +out_free_priv:
> +	kfree(imsic);
> +	imsic = NULL;
> +	return rc;
> +}
> diff --git a/drivers/irqchip/irq-riscv-imsic-state.h b/drivers/irqchip/irq-riscv-imsic-state.h
> new file mode 100644
> index 000000000000..3170018949a8
> --- /dev/null
> +++ b/drivers/irqchip/irq-riscv-imsic-state.h
> @@ -0,0 +1,66 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> + * Copyright (C) 2022 Ventana Micro Systems Inc.
> + */
> +
> +#ifndef _IRQ_RISCV_IMSIC_STATE_H
> +#define _IRQ_RISCV_IMSIC_STATE_H
> +
> +#include <linux/irqchip/riscv-imsic.h>
> +#include <linux/irqdomain.h>
> +#include <linux/fwnode.h>
> +
> +struct imsic_priv {
> +	/* Device details */
> +	struct fwnode_handle *fwnode;
> +
> +	/* Global configuration common for all HARTs */
> +	struct imsic_global_config global;
> +
> +	/* Global state of interrupt identities */
> +	raw_spinlock_t ids_lock;
> +	unsigned long *ids_used_bimap;
> +	unsigned long *ids_enabled_bimap;
> +	unsigned int *ids_target_cpu;
> +
> +	/* IPI interrupt identity and synchronization */
> +	u32 ipi_id;
> +	int ipi_virq;
> +	struct irq_desc *ipi_lsync_desc;
> +
> +	/* IRQ domains (created by platform driver) */
> +	struct irq_domain *base_domain;
> +	struct irq_domain *plat_domain;
> +};
> +
> +extern struct imsic_priv *imsic;
> +
> +void __imsic_eix_update(unsigned long base_id,
> +			unsigned long num_id, bool pend, bool val);
> +
> +#define __imsic_id_enable(__id)		\
> +	__imsic_eix_update((__id), 1, false, true)
> +#define __imsic_id_disable(__id)	\
> +	__imsic_eix_update((__id), 1, false, false)
> +
> +void imsic_id_set_target(unsigned int id, unsigned int target_cpu);
> +unsigned int imsic_id_get_target(unsigned int id);
> +
> +void imsic_ids_local_sync(void);
> +void imsic_ids_local_delivery(bool enable);
> +
> +#ifdef CONFIG_SMP
> +void imsic_ids_remote_sync(void);
> +#else
> +static inline void imsic_ids_remote_sync(void)
> +{
> +}
> +#endif
> +
> +int imsic_ids_alloc(unsigned int order);
> +void imsic_ids_free(unsigned int base_id, unsigned int order);
> +
> +int imsic_setup_state(struct fwnode_handle *fwnode);
> +
> +#endif
> diff --git a/include/linux/irqchip/riscv-imsic.h b/include/linux/irqchip/riscv-imsic.h
> new file mode 100644
> index 000000000000..1f6fc9a57218
> --- /dev/null
> +++ b/include/linux/irqchip/riscv-imsic.h
> @@ -0,0 +1,86 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> + * Copyright (C) 2022 Ventana Micro Systems Inc.
> + */
> +#ifndef __LINUX_IRQCHIP_RISCV_IMSIC_H
> +#define __LINUX_IRQCHIP_RISCV_IMSIC_H
> +
> +#include <linux/types.h>
> +#include <asm/csr.h>
> +
> +#define IMSIC_MMIO_PAGE_SHIFT		12
> +#define IMSIC_MMIO_PAGE_SZ		(1UL << IMSIC_MMIO_PAGE_SHIFT)
> +#define IMSIC_MMIO_PAGE_LE		0x00
> +#define IMSIC_MMIO_PAGE_BE		0x04
> +
> +#define IMSIC_MIN_ID			63
> +#define IMSIC_MAX_ID			2048
> +
> +#define IMSIC_EIDELIVERY		0x70
> +
> +#define IMSIC_EITHRESHOLD		0x72
> +
> +#define IMSIC_EIP0			0x80
> +#define IMSIC_EIP63			0xbf
> +#define IMSIC_EIPx_BITS			32
> +
> +#define IMSIC_EIE0			0xc0
> +#define IMSIC_EIE63			0xff
> +#define IMSIC_EIEx_BITS			32
> +
> +#define IMSIC_FIRST			IMSIC_EIDELIVERY
> +#define IMSIC_LAST			IMSIC_EIE63
> +
> +#define IMSIC_MMIO_SETIPNUM_LE		0x00
> +#define IMSIC_MMIO_SETIPNUM_BE		0x04
> +
> +struct imsic_local_config {
> +	phys_addr_t msi_pa;
> +	void __iomem *msi_va;
> +};
> +
> +struct imsic_global_config {
> +	/*
> +	 * MSI Target Address Scheme
> +	 *
> +	 * XLEN-1                                                12     0
> +	 * |                                                     |     |
> +	 * -------------------------------------------------------------
> +	 * |xxxxxx|Group Index|xxxxxxxxxxx|HART Index|Guest Index|  0  |
> +	 * -------------------------------------------------------------
> +	 */
> +
> +	/* Bits representing Guest index, HART index, and Group index */
> +	u32 guest_index_bits;
> +	u32 hart_index_bits;
> +	u32 group_index_bits;
> +	u32 group_index_shift;
> +
> +	/* Global base address matching all target MSI addresses */
> +	phys_addr_t base_addr;
> +
> +	/* Number of interrupt identities */
> +	u32 nr_ids;
> +
> +	/* Number of guest interrupt identities */
> +	u32 nr_guest_ids;
> +
> +	/* Per-CPU IMSIC addresses */
> +	struct imsic_local_config __percpu *local;
> +};
> +
> +#ifdef CONFIG_RISCV_IMSIC
> +
> +extern const struct imsic_global_config *imsic_get_global_config(void);
> +
> +#else
> +
> +static inline const struct imsic_global_config *imsic_get_global_config(void)
> +{
> +	return NULL;
> +}
> +
> +#endif
> +
> +#endif
> -- 
> 2.34.1
> 

Re: [PATCH v8 09/16] irqchip: Add RISC-V incoming MSI controller early driver

[Sunil V L]

Hi Anup,

On Tue, Sep 12, 2023 at 11:19:21PM +0530, Anup Patel wrote:
> The RISC-V advanced interrupt architecture (AIA) specification
> defines a new MSI controller called incoming message signalled
> interrupt controller (IMSIC) which manages MSI on per-HART (or
> per-CPU) basis. It also supports IPIs as software injected MSIs.
> (For more details refer https://github.com/riscv/riscv-aia)
> 
> Let us add an early irqchip driver for RISC-V IMSIC which sets
> up the IMSIC state and provide IPIs.
> 
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> ---
>  drivers/irqchip/Kconfig                 |   7 +-
>  drivers/irqchip/Makefile                |   1 +
>  drivers/irqchip/irq-riscv-imsic-early.c | 258 ++++++++++++
>  drivers/irqchip/irq-riscv-imsic-state.c | 523 ++++++++++++++++++++++++
>  drivers/irqchip/irq-riscv-imsic-state.h |  66 +++
>  include/linux/irqchip/riscv-imsic.h     |  86 ++++
>  6 files changed, 940 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/irqchip/irq-riscv-imsic-early.c
>  create mode 100644 drivers/irqchip/irq-riscv-imsic-state.c
>  create mode 100644 drivers/irqchip/irq-riscv-imsic-state.h
>  create mode 100644 include/linux/irqchip/riscv-imsic.h
> 
> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> index f7149d0f3d45..ee99aacbefcc 100644
> --- a/drivers/irqchip/Kconfig
> +++ b/drivers/irqchip/Kconfig
> @@ -30,7 +30,6 @@ config ARM_GIC_V2M
>  
>  config GIC_NON_BANKED
>  	bool
> -
>  config ARM_GIC_V3
>  	bool
>  	select IRQ_DOMAIN_HIERARCHY
> @@ -546,6 +545,12 @@ config SIFIVE_PLIC
>  	select IRQ_DOMAIN_HIERARCHY
>  	select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
>  
> +config RISCV_IMSIC
> +	bool
> +	depends on RISCV
> +	select IRQ_DOMAIN_HIERARCHY
> +	select GENERIC_MSI_IRQ
> +
>  config EXYNOS_IRQ_COMBINER
>  	bool "Samsung Exynos IRQ combiner support" if COMPILE_TEST
>  	depends on (ARCH_EXYNOS && ARM) || COMPILE_TEST
> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index ffd945fe71aa..d714724387ce 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -95,6 +95,7 @@ obj-$(CONFIG_QCOM_MPM)			+= irq-qcom-mpm.o
>  obj-$(CONFIG_CSKY_MPINTC)		+= irq-csky-mpintc.o
>  obj-$(CONFIG_CSKY_APB_INTC)		+= irq-csky-apb-intc.o
>  obj-$(CONFIG_RISCV_INTC)		+= irq-riscv-intc.o
> +obj-$(CONFIG_RISCV_IMSIC)		+= irq-riscv-imsic-state.o irq-riscv-imsic-early.o
>  obj-$(CONFIG_SIFIVE_PLIC)		+= irq-sifive-plic.o
>  obj-$(CONFIG_IMX_IRQSTEER)		+= irq-imx-irqsteer.o
>  obj-$(CONFIG_IMX_INTMUX)		+= irq-imx-intmux.o
> diff --git a/drivers/irqchip/irq-riscv-imsic-early.c b/drivers/irqchip/irq-riscv-imsic-early.c
> new file mode 100644
> index 000000000000..1de89ce1ec2f
> --- /dev/null
> +++ b/drivers/irqchip/irq-riscv-imsic-early.c
> @@ -0,0 +1,258 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> + * Copyright (C) 2022 Ventana Micro Systems Inc.
> + */
> +
> +#define pr_fmt(fmt) "riscv-imsic: " fmt
> +#include <linux/cpu.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/irq.h>
> +#include <linux/irqchip.h>
> +#include <linux/irqchip/chained_irq.h>
> +#include <linux/module.h>
> +#include <linux/spinlock.h>
> +#include <linux/smp.h>
> +
> +#include "irq-riscv-imsic-state.h"
> +
> +/*
> + * The IMSIC driver uses 1 IPI for ID synchronization and
> + * arch/riscv/kernel/smp.c require 6 IPIs so we fix the
> + * total number of IPIs to 8.
> + */
> +#define IMSIC_NR_IPI				8
> +
> +static int imsic_parent_irq;
> +
> +#ifdef CONFIG_SMP
> +static irqreturn_t imsic_ids_sync_handler(int irq, void *data)
> +{
> +	imsic_ids_local_sync();
> +	return IRQ_HANDLED;
> +}
> +
> +void imsic_ids_remote_sync(void)
> +{
> +	struct cpumask amask;
> +
> +	/*
> +	 * We simply inject ID synchronization IPI to all target CPUs
> +	 * except current CPU. The ipi_send_mask() implementation of
> +	 * IPI mux will inject ID synchronization IPI only for CPUs
> +	 * that have enabled it so offline CPUs won't receive IPI.
> +	 * An offline CPU will unconditionally synchronize IDs through
> +	 * imsic_starting_cpu() when the CPU is brought up.
> +	 */
> +	cpumask_andnot(&amask, cpu_online_mask, cpumask_of(smp_processor_id()));
> +	__ipi_send_mask(imsic->ipi_lsync_desc, &amask);
> +}
> +
> +static void imsic_ipi_send(unsigned int cpu)
> +{
> +	struct imsic_local_config *local =
> +				per_cpu_ptr(imsic->global.local, cpu);
> +
> +	writel(imsic->ipi_id, local->msi_va);
> +}
> +
> +static void imsic_ipi_starting_cpu(void)
> +{
> +	/* Enable IPIs for current CPU. */
> +	__imsic_id_enable(imsic->ipi_id);
> +
> +	/* Enable virtual IPI used for IMSIC ID synchronization */
> +	enable_percpu_irq(imsic->ipi_virq, 0);
> +}
> +
> +static void imsic_ipi_dying_cpu(void)
> +{
> +	/*
> +	 * Disable virtual IPI used for IMSIC ID synchronization so
> +	 * that we don't receive ID synchronization requests.
> +	 */
> +	disable_percpu_irq(imsic->ipi_virq);
> +}
> +
> +static int __init imsic_ipi_domain_init(void)
> +{
> +	int virq;
> +
> +	/* Allocate interrupt identity for IPIs */
> +	virq = imsic_ids_alloc(get_count_order(1));
> +	if (virq < 0)
> +		return virq;
> +	imsic->ipi_id = virq;
> +
> +	/* Create IMSIC IPI multiplexing */
> +	virq = ipi_mux_create(IMSIC_NR_IPI, imsic_ipi_send);
> +	if (virq <= 0) {
> +		imsic_ids_free(imsic->ipi_id, get_count_order(1));
> +		return (virq < 0) ? virq : -ENOMEM;
> +	}
> +	imsic->ipi_virq = virq;
> +
> +	/* First vIRQ is used for IMSIC ID synchronization */
> +	virq = request_percpu_irq(imsic->ipi_virq, imsic_ids_sync_handler,
> +				  "riscv-imsic-lsync", imsic->global.local);
> +	if (virq) {
> +		imsic_ids_free(imsic->ipi_id, get_count_order(1));
> +		return virq;
> +	}
> +	irq_set_status_flags(imsic->ipi_virq, IRQ_HIDDEN);
> +	imsic->ipi_lsync_desc = irq_to_desc(imsic->ipi_virq);
> +
> +	/* Set vIRQ range */
> +	riscv_ipi_set_virq_range(imsic->ipi_virq + 1, IMSIC_NR_IPI - 1, true);
> +
> +	/* Announce that IMSIC is providing IPIs */
> +	pr_info("%pfwP: providing IPIs using interrupt %d\n",
> +		imsic->fwnode, imsic->ipi_id);
> +
> +	return 0;
> +}
> +#else
> +static void imsic_ipi_starting_cpu(void)
> +{
> +}
> +
> +static void imsic_ipi_dying_cpu(void)
> +{
> +}
> +
> +static int __init imsic_ipi_domain_init(void)
> +{
> +	/* Clear the IPI id because we are not using IPIs */
> +	imsic->ipi_id = 0;
> +	return 0;
> +}
> +#endif
> +
> +/*
> + * To handle an interrupt, we read the TOPEI CSR and write zero in one
> + * instruction. If TOPEI CSR is non-zero then we translate TOPEI.ID to
> + * Linux interrupt number and let Linux IRQ subsystem handle it.
> + */
> +static void imsic_handle_irq(struct irq_desc *desc)
> +{
> +	struct irq_chip *chip = irq_desc_get_chip(desc);
> +	irq_hw_number_t hwirq;
> +	int err;
> +
> +	chained_irq_enter(chip, desc);
> +
> +	while ((hwirq = csr_swap(CSR_TOPEI, 0))) {
> +		hwirq = hwirq >> TOPEI_ID_SHIFT;
> +
> +		if (hwirq == imsic->ipi_id) {
> +#ifdef CONFIG_SMP
> +			ipi_mux_process();
> +#endif
> +			continue;
> +		}
> +
> +		if (unlikely(!imsic->base_domain))
> +			continue;
> +
> +		err = generic_handle_domain_irq(imsic->base_domain, hwirq);
> +		if (unlikely(err))
> +			pr_warn_ratelimited(
> +				"hwirq %lu mapping not found\n", hwirq);
> +	}
> +
> +	chained_irq_exit(chip, desc);
> +}
> +
> +static int imsic_starting_cpu(unsigned int cpu)
> +{
> +	/* Enable per-CPU parent interrupt */
> +	enable_percpu_irq(imsic_parent_irq,
> +			  irq_get_trigger_type(imsic_parent_irq));
> +
> +	/* Setup IPIs */
> +	imsic_ipi_starting_cpu();
> +
> +	/*
> +	 * Interrupts identities might have been enabled/disabled while
> +	 * this CPU was not running so sync-up local enable/disable state.
> +	 */
> +	imsic_ids_local_sync();
> +
> +	/* Enable local interrupt delivery */
> +	imsic_ids_local_delivery(true);
> +
> +	return 0;
> +}
> +
> +static int imsic_dying_cpu(unsigned int cpu)
> +{
> +	/* Cleanup IPIs */
> +	imsic_ipi_dying_cpu();
> +
> +	return 0;
> +}
> +
> +static int __init imsic_early_probe(struct fwnode_handle *fwnode)

Can this imsic_early_probe() take an additional pointer as parameter?
This parameter can be NULL for DT and we can use to pass the MADT
structure in case of ACPI since fwnode in ACPI will not have any
properties. The parameter needs to be passed to imsic_setup_state()
also.

> +{
> +	int rc;
> +	struct irq_domain *domain;
> +
> +	/* Setup IMSIC state */
> +	rc = imsic_setup_state(fwnode);
> +	if (rc) {
> +		pr_err("%pfwP: failed to setup state (error %d)\n",
> +			fwnode, rc);
> +		return rc;
> +	}
> +
> +	/* Find parent domain and register chained handler */
> +	domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
> +					  DOMAIN_BUS_ANY);
> +	if (!domain) {
> +		pr_err("%pfwP: Failed to find INTC domain\n", fwnode);
> +		return -ENOENT;
> +	}
> +	imsic_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT);
> +	if (!imsic_parent_irq) {
> +		pr_err("%pfwP: Failed to create INTC mapping\n", fwnode);
> +		return -ENOENT;
> +	}
> +	irq_set_chained_handler(imsic_parent_irq, imsic_handle_irq);
> +
> +	/* Initialize IPI domain */
> +	rc = imsic_ipi_domain_init();
> +	if (rc) {
> +		pr_err("%pfwP: Failed to initialize IPI domain\n", fwnode);
> +		return rc;
> +	}
> +
> +	/*
> +	 * Setup cpuhp state (must be done after setting imsic_parent_irq)
> +	 *
> +	 * Don't disable per-CPU IMSIC file when CPU goes offline
> +	 * because this affects IPI and the masking/unmasking of
> +	 * virtual IPIs is done via generic IPI-Mux
> +	 */
> +	cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
> +			  "irqchip/riscv/imsic:starting",
> +			  imsic_starting_cpu, imsic_dying_cpu);
> +
> +	return 0;
> +}
> +
> +static int __init imsic_early_dt_init(struct device_node *node,
> +				      struct device_node *parent)
> +{
> +	int rc;
> +
> +	/* Do early setup of IMSIC state and IPIs */
> +	rc = imsic_early_probe(&node->fwnode);
> +	if (rc)
> +		return rc;
> +
> +	/* Ensure that OF platform device gets probed */
> +	of_node_clear_flag(node, OF_POPULATED);
> +	return 0;
> +}
> +IRQCHIP_DECLARE(riscv_imsic, "riscv,imsics", imsic_early_dt_init);
> diff --git a/drivers/irqchip/irq-riscv-imsic-state.c b/drivers/irqchip/irq-riscv-imsic-state.c
> new file mode 100644
> index 000000000000..412b5b919dcc
> --- /dev/null
> +++ b/drivers/irqchip/irq-riscv-imsic-state.c
> @@ -0,0 +1,523 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> + * Copyright (C) 2022 Ventana Micro Systems Inc.
> + */
> +
> +#define pr_fmt(fmt) "riscv-imsic: " fmt
> +#include <linux/bitmap.h>
> +#include <linux/module.h>
> +#include <linux/of_address.h>
> +#include <linux/spinlock.h>
> +#include <linux/smp.h>
> +#include <asm/hwcap.h>
> +
> +#include "irq-riscv-imsic-state.h"
> +
> +#define IMSIC_DISABLE_EIDELIVERY		0
> +#define IMSIC_ENABLE_EIDELIVERY			1
> +#define IMSIC_DISABLE_EITHRESHOLD		1
> +#define IMSIC_ENABLE_EITHRESHOLD		0
> +
> +#define imsic_csr_write(__c, __v)		\
> +do {						\
> +	csr_write(CSR_ISELECT, __c);		\
> +	csr_write(CSR_IREG, __v);		\
> +} while (0)
> +
> +#define imsic_csr_read(__c)			\
> +({						\
> +	unsigned long __v;			\
> +	csr_write(CSR_ISELECT, __c);		\
> +	__v = csr_read(CSR_IREG);		\
> +	__v;					\
> +})
> +
> +#define imsic_csr_set(__c, __v)			\
> +do {						\
> +	csr_write(CSR_ISELECT, __c);		\
> +	csr_set(CSR_IREG, __v);			\
> +} while (0)
> +
> +#define imsic_csr_clear(__c, __v)		\
> +do {						\
> +	csr_write(CSR_ISELECT, __c);		\
> +	csr_clear(CSR_IREG, __v);		\
> +} while (0)
> +
> +struct imsic_priv *imsic;
> +
> +const struct imsic_global_config *imsic_get_global_config(void)
> +{
> +	return (imsic) ? &imsic->global : NULL;
> +}
> +EXPORT_SYMBOL_GPL(imsic_get_global_config);
> +
> +void __imsic_eix_update(unsigned long base_id,
> +			unsigned long num_id, bool pend, bool val)
> +{
> +	unsigned long i, isel, ireg;
> +	unsigned long id = base_id, last_id = base_id + num_id;
> +
> +	while (id < last_id) {
> +		isel = id / BITS_PER_LONG;
> +		isel *= BITS_PER_LONG / IMSIC_EIPx_BITS;
> +		isel += (pend) ? IMSIC_EIP0 : IMSIC_EIE0;
> +
> +		ireg = 0;
> +		for (i = id & (__riscv_xlen - 1);
> +		     (id < last_id) && (i < __riscv_xlen); i++) {
> +			ireg |= BIT(i);
> +			id++;
> +		}
> +
> +		/*
> +		 * The IMSIC EIEx and EIPx registers are indirectly
> +		 * accessed via using ISELECT and IREG CSRs so we
> +		 * need to access these CSRs without getting preempted.
> +		 *
> +		 * All existing users of this function call this
> +		 * function with local IRQs disabled so we don't
> +		 * need to do anything special here.
> +		 */
> +		if (val)
> +			imsic_csr_set(isel, ireg);
> +		else
> +			imsic_csr_clear(isel, ireg);
> +	}
> +}
> +
> +void imsic_id_set_target(unsigned int id, unsigned int target_cpu)
> +{
> +	unsigned long flags;
> +
> +	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> +	imsic->ids_target_cpu[id] = target_cpu;
> +	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> +}
> +
> +unsigned int imsic_id_get_target(unsigned int id)
> +{
> +	unsigned int ret;
> +	unsigned long flags;
> +
> +	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> +	ret = imsic->ids_target_cpu[id];
> +	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> +
> +	return ret;
> +}
> +
> +void imsic_ids_local_sync(void)
> +{
> +	int i;
> +	unsigned long flags;
> +
> +	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> +	for (i = 1; i <= imsic->global.nr_ids; i++) {
> +		if (imsic->ipi_id == i)
> +			continue;
> +
> +		if (test_bit(i, imsic->ids_enabled_bimap))
> +			__imsic_id_enable(i);
> +		else
> +			__imsic_id_disable(i);
> +	}
> +	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> +}
> +
> +void imsic_ids_local_delivery(bool enable)
> +{
> +	if (enable) {
> +		imsic_csr_write(IMSIC_EITHRESHOLD, IMSIC_ENABLE_EITHRESHOLD);
> +		imsic_csr_write(IMSIC_EIDELIVERY, IMSIC_ENABLE_EIDELIVERY);
> +	} else {
> +		imsic_csr_write(IMSIC_EIDELIVERY, IMSIC_DISABLE_EIDELIVERY);
> +		imsic_csr_write(IMSIC_EITHRESHOLD, IMSIC_DISABLE_EITHRESHOLD);
> +	}
> +}
> +
> +int imsic_ids_alloc(unsigned int order)
> +{
> +	int ret;
> +	unsigned long flags;
> +
> +	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> +	ret = bitmap_find_free_region(imsic->ids_used_bimap,
> +				      imsic->global.nr_ids + 1, order);
> +	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> +
> +	return ret;
> +}
> +
> +void imsic_ids_free(unsigned int base_id, unsigned int order)
> +{
> +	unsigned long flags;
> +
> +	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> +	bitmap_release_region(imsic->ids_used_bimap, base_id, order);
> +	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> +}
> +
> +static int __init imsic_ids_init(void)
> +{
> +	int i;
> +	struct imsic_global_config *global = &imsic->global;
> +
> +	raw_spin_lock_init(&imsic->ids_lock);
> +
> +	/* Allocate used bitmap */
> +	imsic->ids_used_bimap = bitmap_zalloc(global->nr_ids + 1, GFP_KERNEL);
> +	if (!imsic->ids_used_bimap)
> +		return -ENOMEM;
> +
> +	/* Allocate enabled bitmap */
> +	imsic->ids_enabled_bimap = bitmap_zalloc(global->nr_ids + 1,
> +						GFP_KERNEL);
> +	if (!imsic->ids_enabled_bimap) {
> +		kfree(imsic->ids_used_bimap);
> +		return -ENOMEM;
> +	}
> +
> +	/* Allocate target CPU array */
> +	imsic->ids_target_cpu = kcalloc(global->nr_ids + 1,
> +				       sizeof(unsigned int), GFP_KERNEL);
> +	if (!imsic->ids_target_cpu) {
> +		bitmap_free(imsic->ids_enabled_bimap);
> +		bitmap_free(imsic->ids_used_bimap);
> +		return -ENOMEM;
> +	}
> +	for (i = 0; i <= global->nr_ids; i++)
> +		imsic->ids_target_cpu[i] = UINT_MAX;
> +
> +	/* Reserve ID#0 because it is special and never implemented */
> +	bitmap_set(imsic->ids_used_bimap, 0, 1);
> +
> +	return 0;
> +}
> +
> +static void __init imsic_ids_cleanup(void)
> +{
> +	kfree(imsic->ids_target_cpu);
> +	bitmap_free(imsic->ids_enabled_bimap);
> +	bitmap_free(imsic->ids_used_bimap);
> +}
> +
> +static int __init imsic_get_parent_hartid(struct fwnode_handle *fwnode,
> +					  u32 index, unsigned long *hartid)
> +{
> +	int rc;
> +	struct fwnode_reference_args parent;
> +
> +	rc = fwnode_property_get_reference_args(fwnode,
> +			"interrupts-extended", "#interrupt-cells",
> +			0, index, &parent);
> +	if (rc)
> +		return rc;
> +
> +	/*
> +	 * Skip interrupts other than external interrupts for
> +	 * current privilege level.
> +	 */
> +	if (parent.args[0] != RV_IRQ_EXT)
> +		return -EINVAL;
> +
> +	return riscv_get_intc_hartid(parent.fwnode, hartid);
> +}
> +
> +static int __init imsic_get_mmio_resource(struct fwnode_handle *fwnode,
> +					  u32 index, struct resource *res)
> +{
> +	/*
> +	 * Currently, only OF fwnode is support so extend this function
> +	 * for other types of fwnode for ACPI support.
> +	 */
> +	if (!is_of_node(fwnode))
> +		return -EINVAL;
> +	return of_address_to_resource(to_of_node(fwnode), index, res);
> +}
> +
> +int __init imsic_setup_state(struct fwnode_handle *fwnode)
> +{
> +	int rc, cpu;
> +	phys_addr_t base_addr;
> +	void __iomem **mmios_va = NULL;
> +	struct resource res, *mmios = NULL;
> +	struct imsic_local_config *local;
> +	struct imsic_global_config *global;
> +	unsigned long reloff, hartid;
> +	u32 i, j, index, nr_parent_irqs, nr_handlers = 0, num_mmios = 0;
> +
> +	/*
> +	 * Only one IMSIC instance allowed in a platform for clean
> +	 * implementation of SMP IRQ affinity and per-CPU IPIs.
> +	 *
> +	 * This means on a multi-socket (or multi-die) platform we
> +	 * will have multiple MMIO regions for one IMSIC instance.
> +	 */
> +	if (imsic) {
> +		pr_err("%pfwP: already initialized hence ignoring\n",
> +			fwnode);
> +		return -EALREADY;
> +	}
> +
> +	if (!riscv_isa_extension_available(NULL, SxAIA)) {
> +		pr_err("%pfwP: AIA support not available\n", fwnode);
> +		return -ENODEV;
> +	}
> +
> +	imsic = kzalloc(sizeof(*imsic), GFP_KERNEL);
> +	if (!imsic)
> +		return -ENOMEM;
> +	imsic->fwnode = fwnode;
> +	global = &imsic->global;
> +
> +	global->local = alloc_percpu(typeof(*(global->local)));
> +	if (!global->local) {
> +		rc = -ENOMEM;
> +		goto out_free_priv;
> +	}
> +
> +	/* Find number of parent interrupts */
> +	nr_parent_irqs = 0;
> +	while (!imsic_get_parent_hartid(fwnode, nr_parent_irqs, &hartid))
> +		nr_parent_irqs++;
> +	if (!nr_parent_irqs) {
> +		pr_err("%pfwP: no parent irqs available\n", fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +
> +	/* Find number of guest index bits in MSI address */
> +	rc = fwnode_property_read_u32_array(fwnode, "riscv,guest-index-bits",
> +					    &global->guest_index_bits, 1);
> +	if (rc)
> +		global->guest_index_bits = 0;
> +	i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT;
> +	if (i < global->guest_index_bits) {
> +		pr_err("%pfwP: guest index bits too big\n", fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +
> +	/* Find number of HART index bits */
> +	rc = fwnode_property_read_u32_array(fwnode, "riscv,hart-index-bits",
> +					    &global->hart_index_bits, 1);
> +	if (rc) {
> +		/* Assume default value */
> +		global->hart_index_bits = __fls(nr_parent_irqs);
> +		if (BIT(global->hart_index_bits) < nr_parent_irqs)
> +			global->hart_index_bits++;
> +	}
> +	i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT - global->guest_index_bits;
> +	if (i < global->hart_index_bits) {
> +		pr_err("%pfwP: HART index bits too big\n", fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +
> +	/* Find number of group index bits */
> +	rc = fwnode_property_read_u32_array(fwnode, "riscv,group-index-bits",
> +					    &global->group_index_bits, 1);
> +	if (rc)
> +		global->group_index_bits = 0;
> +	i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT -
> +	    global->guest_index_bits - global->hart_index_bits;
> +	if (i < global->group_index_bits) {
> +		pr_err("%pfwP: group index bits too big\n", fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +
> +	/*
> +	 * Find first bit position of group index.
> +	 * If not specified assumed the default APLIC-IMSIC configuration.
> +	 */
> +	rc = fwnode_property_read_u32_array(fwnode, "riscv,group-index-shift",
> +					    &global->group_index_shift, 1);
> +	if (rc)
> +		global->group_index_shift = IMSIC_MMIO_PAGE_SHIFT * 2;
> +	i = global->group_index_bits + global->group_index_shift - 1;
> +	if (i >= BITS_PER_LONG) {
> +		pr_err("%pfwP: group index shift too big\n", fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +
> +	/* Find number of interrupt identities */
> +	rc = fwnode_property_read_u32_array(fwnode, "riscv,num-ids",
> +					    &global->nr_ids, 1);
> +	if (rc) {
> +		pr_err("%pfwP: number of interrupt identities not found\n",
> +			fwnode);
> +		goto out_free_local;
> +	}
> +	if ((global->nr_ids < IMSIC_MIN_ID) ||
> +	    (global->nr_ids >= IMSIC_MAX_ID) ||
> +	    ((global->nr_ids & IMSIC_MIN_ID) != IMSIC_MIN_ID)) {
> +		pr_err("%pfwP: invalid number of interrupt identities\n",
> +			fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +
> +	/* Find number of guest interrupt identities */
> +	if (fwnode_property_read_u32_array(fwnode, "riscv,num-guest-ids",
> +					   &global->nr_guest_ids, 1))
> +		global->nr_guest_ids = global->nr_ids;
> +	if ((global->nr_guest_ids < IMSIC_MIN_ID) ||
> +	    (global->nr_guest_ids >= IMSIC_MAX_ID) ||
> +	    ((global->nr_guest_ids & IMSIC_MIN_ID) != IMSIC_MIN_ID)) {
> +		pr_err("%pfwP: invalid number of guest interrupt identities\n",
> +			fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +

Could you create a separate function for DT to fill up this
imsic_global structure? In case of ACPI, we can not get this data from
the fwnode and hence need to have separate function to fill up this
structure.

Thanks!
Sunil
> +	/* Compute base address */
> +	rc = imsic_get_mmio_resource(fwnode, 0, &res);
> +	if (rc) {
> +		pr_err("%pfwP: first MMIO resource not found\n", fwnode);
> +		rc = -EINVAL;
> +		goto out_free_local;
> +	}
> +	global->base_addr = res.start;
> +	global->base_addr &= ~(BIT(global->guest_index_bits +
> +				   global->hart_index_bits +
> +				   IMSIC_MMIO_PAGE_SHIFT) - 1);
> +	global->base_addr &= ~((BIT(global->group_index_bits) - 1) <<
> +			       global->group_index_shift);
> +
> +	/* Find number of MMIO register sets */
> +	while (!imsic_get_mmio_resource(fwnode, num_mmios, &res))
> +		num_mmios++;
> +
> +	/* Allocate MMIO resource array */
> +	mmios = kcalloc(num_mmios, sizeof(*mmios), GFP_KERNEL);
> +	if (!mmios) {
> +		rc = -ENOMEM;
> +		goto out_free_local;
> +	}
> +
> +	/* Allocate MMIO virtual address array */
> +	mmios_va = kcalloc(num_mmios, sizeof(*mmios_va), GFP_KERNEL);
> +	if (!mmios_va) {
> +		rc = -ENOMEM;
> +		goto out_iounmap;
> +	}
> +
> +	/* Parse and map MMIO register sets */
> +	for (i = 0; i < num_mmios; i++) {
> +		rc = imsic_get_mmio_resource(fwnode, i, &mmios[i]);
> +		if (rc) {
> +			pr_err("%pfwP: unable to parse MMIO regset %d\n",
> +				fwnode, i);
> +			goto out_iounmap;
> +		}
> +
> +		base_addr = mmios[i].start;
> +		base_addr &= ~(BIT(global->guest_index_bits +
> +				   global->hart_index_bits +
> +				   IMSIC_MMIO_PAGE_SHIFT) - 1);
> +		base_addr &= ~((BIT(global->group_index_bits) - 1) <<
> +			       global->group_index_shift);
> +		if (base_addr != global->base_addr) {
> +			rc = -EINVAL;
> +			pr_err("%pfwP: address mismatch for regset %d\n",
> +				fwnode, i);
> +			goto out_iounmap;
> +		}
> +
> +		mmios_va[i] = ioremap(mmios[i].start, resource_size(&mmios[i]));
> +		if (!mmios_va[i]) {
> +			rc = -EIO;
> +			pr_err("%pfwP: unable to map MMIO regset %d\n",
> +				fwnode, i);
> +			goto out_iounmap;
> +		}
> +	}
> +
> +	/* Initialize interrupt identity management */
> +	rc = imsic_ids_init();
> +	if (rc) {
> +		pr_err("%pfwP: failed to initialize interrupt management\n",
> +		       fwnode);
> +		goto out_iounmap;
> +	}
> +
> +	/* Configure handlers for target CPUs */
> +	for (i = 0; i < nr_parent_irqs; i++) {
> +		rc = imsic_get_parent_hartid(fwnode, i, &hartid);
> +		if (rc) {
> +			pr_warn("%pfwP: hart ID for parent irq%d not found\n",
> +				fwnode, i);
> +			continue;
> +		}
> +
> +		cpu = riscv_hartid_to_cpuid(hartid);
> +		if (cpu < 0) {
> +			pr_warn("%pfwP: invalid cpuid for parent irq%d\n",
> +				fwnode, i);
> +			continue;
> +		}
> +
> +		/* Find MMIO location of MSI page */
> +		index = num_mmios;
> +		reloff = i * BIT(global->guest_index_bits) *
> +			 IMSIC_MMIO_PAGE_SZ;
> +		for (j = 0; num_mmios; j++) {
> +			if (reloff < resource_size(&mmios[j])) {
> +				index = j;
> +				break;
> +			}
> +
> +			/*
> +			 * MMIO region size may not be aligned to
> +			 * BIT(global->guest_index_bits) * IMSIC_MMIO_PAGE_SZ
> +			 * if holes are present.
> +			 */
> +			reloff -= ALIGN(resource_size(&mmios[j]),
> +			BIT(global->guest_index_bits) * IMSIC_MMIO_PAGE_SZ);
> +		}
> +		if (index >= num_mmios) {
> +			pr_warn("%pfwP: MMIO not found for parent irq%d\n",
> +				fwnode, i);
> +			continue;
> +		}
> +
> +		local = per_cpu_ptr(global->local, cpu);
> +		local->msi_pa = mmios[index].start + reloff;
> +		local->msi_va = mmios_va[index] + reloff;
> +
> +		nr_handlers++;
> +	}
> +
> +	/* If no CPU handlers found then can't take interrupts */
> +	if (!nr_handlers) {
> +		pr_err("%pfwP: No CPU handlers found\n", fwnode);
> +		rc = -ENODEV;
> +		goto out_ids_cleanup;
> +	}
> +
> +	/* We don't need MMIO arrays anymore so let's free-up */
> +	kfree(mmios_va);
> +	kfree(mmios);
> +
> +	return 0;
> +
> +out_ids_cleanup:
> +	imsic_ids_cleanup();
> +out_iounmap:
> +	for (i = 0; i < num_mmios; i++) {
> +		if (mmios_va[i])
> +			iounmap(mmios_va[i]);
> +	}
> +	kfree(mmios_va);
> +	kfree(mmios);
> +out_free_local:
> +	free_percpu(imsic->global.local);
> +out_free_priv:
> +	kfree(imsic);
> +	imsic = NULL;
> +	return rc;
> +}
> diff --git a/drivers/irqchip/irq-riscv-imsic-state.h b/drivers/irqchip/irq-riscv-imsic-state.h
> new file mode 100644
> index 000000000000..3170018949a8
> --- /dev/null
> +++ b/drivers/irqchip/irq-riscv-imsic-state.h
> @@ -0,0 +1,66 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> + * Copyright (C) 2022 Ventana Micro Systems Inc.
> + */
> +
> +#ifndef _IRQ_RISCV_IMSIC_STATE_H
> +#define _IRQ_RISCV_IMSIC_STATE_H
> +
> +#include <linux/irqchip/riscv-imsic.h>
> +#include <linux/irqdomain.h>
> +#include <linux/fwnode.h>
> +
> +struct imsic_priv {
> +	/* Device details */
> +	struct fwnode_handle *fwnode;
> +
> +	/* Global configuration common for all HARTs */
> +	struct imsic_global_config global;
> +
> +	/* Global state of interrupt identities */
> +	raw_spinlock_t ids_lock;
> +	unsigned long *ids_used_bimap;
> +	unsigned long *ids_enabled_bimap;
> +	unsigned int *ids_target_cpu;
> +
> +	/* IPI interrupt identity and synchronization */
> +	u32 ipi_id;
> +	int ipi_virq;
> +	struct irq_desc *ipi_lsync_desc;
> +
> +	/* IRQ domains (created by platform driver) */
> +	struct irq_domain *base_domain;
> +	struct irq_domain *plat_domain;
> +};
> +
> +extern struct imsic_priv *imsic;
> +
> +void __imsic_eix_update(unsigned long base_id,
> +			unsigned long num_id, bool pend, bool val);
> +
> +#define __imsic_id_enable(__id)		\
> +	__imsic_eix_update((__id), 1, false, true)
> +#define __imsic_id_disable(__id)	\
> +	__imsic_eix_update((__id), 1, false, false)
> +
> +void imsic_id_set_target(unsigned int id, unsigned int target_cpu);
> +unsigned int imsic_id_get_target(unsigned int id);
> +
> +void imsic_ids_local_sync(void);
> +void imsic_ids_local_delivery(bool enable);
> +
> +#ifdef CONFIG_SMP
> +void imsic_ids_remote_sync(void);
> +#else
> +static inline void imsic_ids_remote_sync(void)
> +{
> +}
> +#endif
> +
> +int imsic_ids_alloc(unsigned int order);
> +void imsic_ids_free(unsigned int base_id, unsigned int order);
> +
> +int imsic_setup_state(struct fwnode_handle *fwnode);
> +
> +#endif
> diff --git a/include/linux/irqchip/riscv-imsic.h b/include/linux/irqchip/riscv-imsic.h
> new file mode 100644
> index 000000000000..1f6fc9a57218
> --- /dev/null
> +++ b/include/linux/irqchip/riscv-imsic.h
> @@ -0,0 +1,86 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> + * Copyright (C) 2022 Ventana Micro Systems Inc.
> + */
> +#ifndef __LINUX_IRQCHIP_RISCV_IMSIC_H
> +#define __LINUX_IRQCHIP_RISCV_IMSIC_H
> +
> +#include <linux/types.h>
> +#include <asm/csr.h>
> +
> +#define IMSIC_MMIO_PAGE_SHIFT		12
> +#define IMSIC_MMIO_PAGE_SZ		(1UL << IMSIC_MMIO_PAGE_SHIFT)
> +#define IMSIC_MMIO_PAGE_LE		0x00
> +#define IMSIC_MMIO_PAGE_BE		0x04
> +
> +#define IMSIC_MIN_ID			63
> +#define IMSIC_MAX_ID			2048
> +
> +#define IMSIC_EIDELIVERY		0x70
> +
> +#define IMSIC_EITHRESHOLD		0x72
> +
> +#define IMSIC_EIP0			0x80
> +#define IMSIC_EIP63			0xbf
> +#define IMSIC_EIPx_BITS			32
> +
> +#define IMSIC_EIE0			0xc0
> +#define IMSIC_EIE63			0xff
> +#define IMSIC_EIEx_BITS			32
> +
> +#define IMSIC_FIRST			IMSIC_EIDELIVERY
> +#define IMSIC_LAST			IMSIC_EIE63
> +
> +#define IMSIC_MMIO_SETIPNUM_LE		0x00
> +#define IMSIC_MMIO_SETIPNUM_BE		0x04
> +
> +struct imsic_local_config {
> +	phys_addr_t msi_pa;
> +	void __iomem *msi_va;
> +};
> +
> +struct imsic_global_config {
> +	/*
> +	 * MSI Target Address Scheme
> +	 *
> +	 * XLEN-1                                                12     0
> +	 * |                                                     |     |
> +	 * -------------------------------------------------------------
> +	 * |xxxxxx|Group Index|xxxxxxxxxxx|HART Index|Guest Index|  0  |
> +	 * -------------------------------------------------------------
> +	 */
> +
> +	/* Bits representing Guest index, HART index, and Group index */
> +	u32 guest_index_bits;
> +	u32 hart_index_bits;
> +	u32 group_index_bits;
> +	u32 group_index_shift;
> +
> +	/* Global base address matching all target MSI addresses */
> +	phys_addr_t base_addr;
> +
> +	/* Number of interrupt identities */
> +	u32 nr_ids;
> +
> +	/* Number of guest interrupt identities */
> +	u32 nr_guest_ids;
> +
> +	/* Per-CPU IMSIC addresses */
> +	struct imsic_local_config __percpu *local;
> +};
> +
> +#ifdef CONFIG_RISCV_IMSIC
> +
> +extern const struct imsic_global_config *imsic_get_global_config(void);
> +
> +#else
> +
> +static inline const struct imsic_global_config *imsic_get_global_config(void)
> +{
> +	return NULL;
> +}
> +
> +#endif
> +
> +#endif
> -- 
> 2.34.1
> 

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Re: [PATCH v8 13/16] irqchip: Add RISC-V advanced PLIC driver for direct-mode

[Sunil V L]

Hi Anup,

On Tue, Sep 12, 2023 at 11:19:25PM +0530, Anup Patel wrote:
> The RISC-V advanced interrupt architecture (AIA) specification defines
> advanced platform-level interrupt controller (APLIC) which has two modes
> of operation: 1) Direct mode and 2) MSI mode.
> (For more details, refer https://github.com/riscv/riscv-aia)
> 
> In APLIC direct-mode, wired interrupts are forwared to CPUs (or HARTs)
> as a local external interrupt.
> 
> We add a platform irqchip driver for the RISC-V APLIC direct-mode to
> support RISC-V platforms having only wired interrupts.
> 
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> ---
>  drivers/irqchip/Kconfig                  |   5 +
>  drivers/irqchip/Makefile                 |   1 +
>  drivers/irqchip/irq-riscv-aplic-direct.c | 326 +++++++++++++++++++++++
>  drivers/irqchip/irq-riscv-aplic-main.c   | 240 +++++++++++++++++
>  drivers/irqchip/irq-riscv-aplic-main.h   |  45 ++++
>  include/linux/irqchip/riscv-aplic.h      | 119 +++++++++
>  6 files changed, 736 insertions(+)
>  create mode 100644 drivers/irqchip/irq-riscv-aplic-direct.c
>  create mode 100644 drivers/irqchip/irq-riscv-aplic-main.c
>  create mode 100644 drivers/irqchip/irq-riscv-aplic-main.h
>  create mode 100644 include/linux/irqchip/riscv-aplic.h
> 
> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> index a6aad78076a0..44c455084d09 100644
> --- a/drivers/irqchip/Kconfig
> +++ b/drivers/irqchip/Kconfig
> @@ -545,6 +545,11 @@ config SIFIVE_PLIC
>  	select IRQ_DOMAIN_HIERARCHY
>  	select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
>  
> +config RISCV_APLIC
> +	bool
> +	depends on RISCV
> +	select IRQ_DOMAIN_HIERARCHY
> +
>  config RISCV_IMSIC
>  	bool
>  	depends on RISCV
> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index abca445a3229..7f8289790ed8 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -95,6 +95,7 @@ obj-$(CONFIG_QCOM_MPM)			+= irq-qcom-mpm.o
>  obj-$(CONFIG_CSKY_MPINTC)		+= irq-csky-mpintc.o
>  obj-$(CONFIG_CSKY_APB_INTC)		+= irq-csky-apb-intc.o
>  obj-$(CONFIG_RISCV_INTC)		+= irq-riscv-intc.o
> +obj-$(CONFIG_RISCV_APLIC)		+= irq-riscv-aplic-main.o irq-riscv-aplic-direct.o
>  obj-$(CONFIG_RISCV_IMSIC)		+= irq-riscv-imsic-state.o irq-riscv-imsic-early.o irq-riscv-imsic-platform.o
>  obj-$(CONFIG_SIFIVE_PLIC)		+= irq-sifive-plic.o
>  obj-$(CONFIG_IMX_IRQSTEER)		+= irq-imx-irqsteer.o
> diff --git a/drivers/irqchip/irq-riscv-aplic-direct.c b/drivers/irqchip/irq-riscv-aplic-direct.c
> new file mode 100644
> index 000000000000..e36d655a1490
> --- /dev/null
> +++ b/drivers/irqchip/irq-riscv-aplic-direct.c
> @@ -0,0 +1,326 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> + * Copyright (C) 2022 Ventana Micro Systems Inc.
> + */
> +
> +#include <linux/bitops.h>
> +#include <linux/cpu.h>
> +#include <linux/interrupt.h>
> +#include <linux/irqchip.h>
> +#include <linux/irqchip/chained_irq.h>
> +#include <linux/irqchip/riscv-aplic.h>
> +#include <linux/module.h>
> +#include <linux/of_address.h>
> +#include <linux/printk.h>
> +#include <linux/smp.h>
> +
> +#include "irq-riscv-aplic-main.h"
> +
> +#define APLIC_DISABLE_IDELIVERY		0
> +#define APLIC_ENABLE_IDELIVERY		1
> +#define APLIC_DISABLE_ITHRESHOLD	1
> +#define APLIC_ENABLE_ITHRESHOLD		0
> +
> +struct aplic_direct {
> +	struct aplic_priv	priv;
> +	struct irq_domain	*irqdomain;
> +	struct cpumask		lmask;
> +};
> +
> +struct aplic_idc {
> +	unsigned int		hart_index;
> +	void __iomem		*regs;
> +	struct aplic_direct	*direct;
> +};
> +
> +static unsigned int aplic_direct_parent_irq;
> +static DEFINE_PER_CPU(struct aplic_idc, aplic_idcs);
> +
> +static void aplic_direct_irq_eoi(struct irq_data *d)
> +{
> +	/*
> +	 * The fasteoi_handler requires irq_eoi() callback hence
> +	 * provide a dummy handler.
> +	 */
> +}
> +
> +#ifdef CONFIG_SMP
> +static int aplic_direct_set_affinity(struct irq_data *d,
> +				  const struct cpumask *mask_val, bool force)
> +{
> +	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
> +	struct aplic_direct *direct =
> +			container_of(priv, struct aplic_direct, priv);
> +	struct aplic_idc *idc;
> +	unsigned int cpu, val;
> +	struct cpumask amask;
> +	void __iomem *target;
> +
> +	cpumask_and(&amask, &direct->lmask, mask_val);
> +
> +	if (force)
> +		cpu = cpumask_first(&amask);
> +	else
> +		cpu = cpumask_any_and(&amask, cpu_online_mask);
> +
> +	if (cpu >= nr_cpu_ids)
> +		return -EINVAL;
> +
> +	idc = per_cpu_ptr(&aplic_idcs, cpu);
> +	target = priv->regs + APLIC_TARGET_BASE;
> +	target += (d->hwirq - 1) * sizeof(u32);
> +	val = idc->hart_index & APLIC_TARGET_HART_IDX_MASK;
> +	val <<= APLIC_TARGET_HART_IDX_SHIFT;
> +	val |= APLIC_DEFAULT_PRIORITY;
> +	writel(val, target);
> +
> +	irq_data_update_effective_affinity(d, cpumask_of(cpu));
> +
> +	return IRQ_SET_MASK_OK_DONE;
> +}
> +#endif
> +
> +static struct irq_chip aplic_direct_chip = {
> +	.name		= "APLIC-DIRECT",
> +	.irq_mask	= aplic_irq_mask,
> +	.irq_unmask	= aplic_irq_unmask,
> +	.irq_set_type	= aplic_irq_set_type,
> +	.irq_eoi	= aplic_direct_irq_eoi,
> +#ifdef CONFIG_SMP
> +	.irq_set_affinity = aplic_direct_set_affinity,
> +#endif
> +	.flags		= IRQCHIP_SET_TYPE_MASKED |
> +			  IRQCHIP_SKIP_SET_WAKE |
> +			  IRQCHIP_MASK_ON_SUSPEND,
> +};
> +
> +static int aplic_direct_irqdomain_translate(struct irq_domain *d,
> +					 struct irq_fwspec *fwspec,
> +					 unsigned long *hwirq,
> +					 unsigned int *type)
> +{
> +	struct aplic_priv *priv = d->host_data;
> +
> +	return aplic_irqdomain_translate(fwspec, priv->gsi_base,
> +					 hwirq, type);
> +}
> +
> +static int aplic_direct_irqdomain_alloc(struct irq_domain *domain,
> +				     unsigned int virq, unsigned int nr_irqs,
> +				     void *arg)
> +{
> +	int i, ret;
> +	unsigned int type;
> +	irq_hw_number_t hwirq;
> +	struct irq_fwspec *fwspec = arg;
> +	struct aplic_priv *priv = domain->host_data;
> +	struct aplic_direct *direct =
> +			container_of(priv, struct aplic_direct, priv);
> +
> +	ret = aplic_irqdomain_translate(fwspec, priv->gsi_base,
> +					&hwirq, &type);
> +	if (ret)
> +		return ret;
> +
> +	for (i = 0; i < nr_irqs; i++) {
> +		irq_domain_set_info(domain, virq + i, hwirq + i,
> +				    &aplic_direct_chip, priv,
> +				    handle_fasteoi_irq, NULL, NULL);
> +		irq_set_affinity(virq + i, &direct->lmask);
> +		/* See the reason described in aplic_msi_irqdomain_alloc() */
> +		irq_set_status_flags(virq + i, IRQ_DISABLE_UNLAZY);
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct irq_domain_ops aplic_direct_irqdomain_ops = {
> +	.translate	= aplic_direct_irqdomain_translate,
> +	.alloc		= aplic_direct_irqdomain_alloc,
> +	.free		= irq_domain_free_irqs_top,
> +};
> +
> +/*
> + * To handle an APLIC direct interrupts, we just read the CLAIMI register
> + * which will return highest priority pending interrupt and clear the
> + * pending bit of the interrupt. This process is repeated until CLAIMI
> + * register return zero value.
> + */
> +static void aplic_direct_handle_irq(struct irq_desc *desc)
> +{
> +	struct aplic_idc *idc = this_cpu_ptr(&aplic_idcs);
> +	struct irq_chip *chip = irq_desc_get_chip(desc);
> +	struct irq_domain *irqdomain = idc->direct->irqdomain;
> +	irq_hw_number_t hw_irq;
> +	int irq;
> +
> +	chained_irq_enter(chip, desc);
> +
> +	while ((hw_irq = readl(idc->regs + APLIC_IDC_CLAIMI))) {
> +		hw_irq = hw_irq >> APLIC_IDC_TOPI_ID_SHIFT;
> +		irq = irq_find_mapping(irqdomain, hw_irq);
> +
> +		if (unlikely(irq <= 0))
> +			dev_warn_ratelimited(idc->direct->priv.dev,
> +					     "hw_irq %lu mapping not found\n",
> +					     hw_irq);
> +		else
> +			generic_handle_irq(irq);
> +	}
> +
> +	chained_irq_exit(chip, desc);
> +}
> +
> +static void aplic_idc_set_delivery(struct aplic_idc *idc, bool en)
> +{
> +	u32 de = (en) ? APLIC_ENABLE_IDELIVERY : APLIC_DISABLE_IDELIVERY;
> +	u32 th = (en) ? APLIC_ENABLE_ITHRESHOLD : APLIC_DISABLE_ITHRESHOLD;
> +
> +	/* Priority must be less than threshold for interrupt triggering */
> +	writel(th, idc->regs + APLIC_IDC_ITHRESHOLD);
> +
> +	/* Delivery must be set to 1 for interrupt triggering */
> +	writel(de, idc->regs + APLIC_IDC_IDELIVERY);
> +}
> +
> +static int aplic_direct_dying_cpu(unsigned int cpu)
> +{
> +	if (aplic_direct_parent_irq)
> +		disable_percpu_irq(aplic_direct_parent_irq);
> +
> +	return 0;
> +}
> +
> +static int aplic_direct_starting_cpu(unsigned int cpu)
> +{
> +	if (aplic_direct_parent_irq)
> +		enable_percpu_irq(aplic_direct_parent_irq,
> +				irq_get_trigger_type(aplic_direct_parent_irq));
> +
> +	return 0;
> +}
> +
> +int aplic_direct_setup(struct device *dev, void __iomem *regs)
> +{
> +	int i, j, rc, cpu, setup_count = 0;
> +	struct fwnode_reference_args parent;
> +	struct aplic_direct *direct;
> +	struct aplic_priv *priv;
> +	struct irq_domain *domain;
> +	unsigned long hartid;
> +	struct aplic_idc *idc;
> +	u32 val;
> +
> +	direct = kzalloc(sizeof(*direct), GFP_KERNEL);
> +	if (!direct)
> +		return -ENOMEM;
> +	priv = &direct->priv;
> +
> +	rc = aplic_setup_priv(priv, dev, regs);
> +	if (rc) {
> +		dev_err(dev, "failed to create APLIC context\n");
> +		kfree(direct);
> +		return rc;
> +	}
> +
> +	/* Setup per-CPU IDC and target CPU mask */
> +	for (i = 0; i < priv->nr_idcs; i++) {
> +		rc = fwnode_property_get_reference_args(dev->fwnode,
> +				"interrupts-extended", "#interrupt-cells",
> +				0, i, &parent);
> +		if (rc) {
> +			dev_warn(dev, "parent irq for IDC%d not found\n", i);
> +			continue;
> +		}
> +
> +		/*
> +		 * Skip interrupts other than external interrupts for
> +		 * current privilege level.
> +		 */
> +		if (parent.args[0] != RV_IRQ_EXT)
> +			continue;
> +
> +		rc = riscv_get_intc_hartid(parent.fwnode, &hartid);
> +		if (rc) {
> +			dev_warn(dev, "invalid hartid for IDC%d\n", i);
> +			continue;
> +		}
> +
> +		cpu = riscv_hartid_to_cpuid(hartid);
> +		if (cpu < 0) {
> +			dev_warn(dev, "invalid cpuid for IDC%d\n", i);
> +			continue;
> +		}
> +
> +		cpumask_set_cpu(cpu, &direct->lmask);
> +
> +		idc = per_cpu_ptr(&aplic_idcs, cpu);
> +		idc->hart_index = i;
> +		idc->regs = priv->regs + APLIC_IDC_BASE + i * APLIC_IDC_SIZE;
> +		idc->direct = direct;
> +
> +		aplic_idc_set_delivery(idc, true);
> +
> +		/*
> +		 * Boot cpu might not have APLIC hart_index = 0 so check
> +		 * and update target registers of all interrupts.
> +		 */
> +		if (cpu == smp_processor_id() && idc->hart_index) {
> +			val = idc->hart_index & APLIC_TARGET_HART_IDX_MASK;
> +			val <<= APLIC_TARGET_HART_IDX_SHIFT;
> +			val |= APLIC_DEFAULT_PRIORITY;
> +			for (j = 1; j <= priv->nr_irqs; j++)
> +				writel(val, priv->regs + APLIC_TARGET_BASE +
> +					    (j - 1) * sizeof(u32));
> +		}
> +
> +		setup_count++;
> +	}
> +
> +	/* Find parent domain and register chained handler */
> +	domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
> +					  DOMAIN_BUS_ANY);
> +	if (!aplic_direct_parent_irq && domain) {
> +		aplic_direct_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT);
> +		if (aplic_direct_parent_irq) {
> +			irq_set_chained_handler(aplic_direct_parent_irq,
> +						aplic_direct_handle_irq);
> +
> +			/*
> +			 * Setup CPUHP notifier to enable parent
> +			 * interrupt on all CPUs
> +			 */
> +			cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
> +					  "irqchip/riscv/aplic:starting",
> +					  aplic_direct_starting_cpu,
> +					  aplic_direct_dying_cpu);
> +		}
> +	}
> +
> +	/* Fail if we were not able to setup IDC for any CPU */
> +	if (!setup_count) {
> +		kfree(direct);
> +		return -ENODEV;
> +	}
> +
> +	/* Setup global config and interrupt delivery */
> +	aplic_init_hw_global(priv, false);
> +
> +	/* Create irq domain instance for the APLIC */
> +	direct->irqdomain = irq_domain_create_linear(dev->fwnode,
> +						   priv->nr_irqs + 1,
> +						   &aplic_direct_irqdomain_ops,
> +						   priv);
> +	if (!direct->irqdomain) {
> +		dev_err(dev, "failed to create direct irq domain\n");
> +		kfree(direct);
> +		return -ENOMEM;
> +	}
> +
> +	/* Advertise the interrupt controller */
> +	dev_info(dev, "%d interrupts directly connected to %d CPUs\n",
> +		 priv->nr_irqs, priv->nr_idcs);
> +
> +	return 0;
> +}
> diff --git a/drivers/irqchip/irq-riscv-aplic-main.c b/drivers/irqchip/irq-riscv-aplic-main.c
> new file mode 100644
> index 000000000000..d62a096774c4
> --- /dev/null
> +++ b/drivers/irqchip/irq-riscv-aplic-main.c
> @@ -0,0 +1,240 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> + * Copyright (C) 2022 Ventana Micro Systems Inc.
> + */
> +
> +#include <linux/printk.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/irqchip/riscv-aplic.h>
> +
> +#include "irq-riscv-aplic-main.h"
> +
> +void aplic_irq_unmask(struct irq_data *d)
> +{
> +	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
> +
> +	writel(d->hwirq, priv->regs + APLIC_SETIENUM);
> +}
> +
> +void aplic_irq_mask(struct irq_data *d)
> +{
> +	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
> +
> +	writel(d->hwirq, priv->regs + APLIC_CLRIENUM);
> +}
> +
> +int aplic_irq_set_type(struct irq_data *d, unsigned int type)
> +{
> +	u32 val = 0;
> +	void __iomem *sourcecfg;
> +	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
> +
> +	switch (type) {
> +	case IRQ_TYPE_NONE:
> +		val = APLIC_SOURCECFG_SM_INACTIVE;
> +		break;
> +	case IRQ_TYPE_LEVEL_LOW:
> +		val = APLIC_SOURCECFG_SM_LEVEL_LOW;
> +		break;
> +	case IRQ_TYPE_LEVEL_HIGH:
> +		val = APLIC_SOURCECFG_SM_LEVEL_HIGH;
> +		break;
> +	case IRQ_TYPE_EDGE_FALLING:
> +		val = APLIC_SOURCECFG_SM_EDGE_FALL;
> +		break;
> +	case IRQ_TYPE_EDGE_RISING:
> +		val = APLIC_SOURCECFG_SM_EDGE_RISE;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	sourcecfg = priv->regs + APLIC_SOURCECFG_BASE;
> +	sourcecfg += (d->hwirq - 1) * sizeof(u32);
> +	writel(val, sourcecfg);
> +
> +	return 0;
> +}
> +
> +int aplic_irqdomain_translate(struct irq_fwspec *fwspec, u32 gsi_base,
> +			      unsigned long *hwirq, unsigned int *type)
> +{
> +	if (WARN_ON(fwspec->param_count < 2))
> +		return -EINVAL;
> +	if (WARN_ON(!fwspec->param[0]))
> +		return -EINVAL;
> +
> +	/* For DT, gsi_base is always zero. */
> +	*hwirq = fwspec->param[0] - gsi_base;
> +	*type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
> +
> +	WARN_ON(*type == IRQ_TYPE_NONE);
> +
> +	return 0;
> +}
> +
> +void aplic_init_hw_global(struct aplic_priv *priv, bool msi_mode)
> +{
> +	u32 val;
> +#ifdef CONFIG_RISCV_M_MODE
> +	u32 valH;
> +
> +	if (msi_mode) {
> +		val = priv->msicfg.base_ppn;
> +		valH = ((u64)priv->msicfg.base_ppn >> 32) &
> +			APLIC_xMSICFGADDRH_BAPPN_MASK;
> +		valH |= (priv->msicfg.lhxw & APLIC_xMSICFGADDRH_LHXW_MASK)
> +			<< APLIC_xMSICFGADDRH_LHXW_SHIFT;
> +		valH |= (priv->msicfg.hhxw & APLIC_xMSICFGADDRH_HHXW_MASK)
> +			<< APLIC_xMSICFGADDRH_HHXW_SHIFT;
> +		valH |= (priv->msicfg.lhxs & APLIC_xMSICFGADDRH_LHXS_MASK)
> +			<< APLIC_xMSICFGADDRH_LHXS_SHIFT;
> +		valH |= (priv->msicfg.hhxs & APLIC_xMSICFGADDRH_HHXS_MASK)
> +			<< APLIC_xMSICFGADDRH_HHXS_SHIFT;
> +		writel(val, priv->regs + APLIC_xMSICFGADDR);
> +		writel(valH, priv->regs + APLIC_xMSICFGADDRH);
> +	}
> +#endif
> +
> +	/* Setup APLIC domaincfg register */
> +	val = readl(priv->regs + APLIC_DOMAINCFG);
> +	val |= APLIC_DOMAINCFG_IE;
> +	if (msi_mode)
> +		val |= APLIC_DOMAINCFG_DM;
> +	writel(val, priv->regs + APLIC_DOMAINCFG);
> +	if (readl(priv->regs + APLIC_DOMAINCFG) != val)
> +		dev_warn(priv->dev, "unable to write 0x%x in domaincfg\n",
> +			 val);
> +}
> +
> +static void aplic_init_hw_irqs(struct aplic_priv *priv)
> +{
> +	int i;
> +
> +	/* Disable all interrupts */
> +	for (i = 0; i <= priv->nr_irqs; i += 32)
> +		writel(-1U, priv->regs + APLIC_CLRIE_BASE +
> +			    (i / 32) * sizeof(u32));
> +
> +	/* Set interrupt type and default priority for all interrupts */
> +	for (i = 1; i <= priv->nr_irqs; i++) {
> +		writel(0, priv->regs + APLIC_SOURCECFG_BASE +
> +			  (i - 1) * sizeof(u32));
> +		writel(APLIC_DEFAULT_PRIORITY,
> +		       priv->regs + APLIC_TARGET_BASE +
> +		       (i - 1) * sizeof(u32));
> +	}
> +
> +	/* Clear APLIC domaincfg */
> +	writel(0, priv->regs + APLIC_DOMAINCFG);
> +}
> +
> +int aplic_setup_priv(struct aplic_priv *priv, struct device *dev,
> +		     void __iomem *regs)
> +{
> +	struct fwnode_reference_args parent;
> +	int rc;
> +
> +	/* Save device pointer and register base */
> +	priv->dev = dev;
> +	priv->regs = regs;
> +
> +	/*
> +	 * Find out GSI base number
> +	 *
> +	 * Note: DT does not define "riscv,gsi-base" property so GSI
> +	 * base is always zero for DT.
> +	 */
> +	rc = fwnode_property_read_u32_array(dev->fwnode, "riscv,gsi-base",
> +					    &priv->gsi_base, 1);
For DT, you can just initialize this to 0 without reading the property.

> +	if (rc)
> +		priv->gsi_base = 0;
> +
> +	/* Find out number of interrupt sources */
> +	rc = fwnode_property_read_u32_array(dev->fwnode, "riscv,num-sources",
> +					    &priv->nr_irqs, 1);
> +	if (rc) {
> +		dev_err(dev, "failed to get number of interrupt sources\n");
> +		return rc;
> +	}
> +
> +	/* Setup initial state APLIC interrupts */
> +	aplic_init_hw_irqs(priv);
> +
> +	/*
> +	 * Find out number of IDCs based on parent interrupts
> +	 *
> +	 * If "msi-parent" property is present then we ignore the
> +	 * APLIC IDCs which forces the APLIC driver to use MSI mode.
> +	 */
> +	if (!fwnode_property_present(dev->fwnode, "msi-parent")) {
> +		while (!fwnode_property_get_reference_args(dev->fwnode,
> +				"interrupts-extended", "#interrupt-cells",
> +				0, priv->nr_idcs, &parent))
> +			priv->nr_idcs++;
> +	}
> +
Can this finding nr_idcs be done after aplic_init_hw_irqs() above?

> +	return 0;
> +}
> +
> +static int aplic_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct resource *res;
> +	void __iomem *regs;
> +	int rc;
> +
> +	/* Map the MMIO registers */
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!res) {
> +		dev_err(dev, "failed to get MMIO resource\n");
> +		return -EINVAL;
> +	}
> +	regs = devm_ioremap(&pdev->dev, res->start, resource_size(res));
> +	if (!regs) {
> +		dev_err(dev, "failed map MMIO registers\n");
> +		return -ENOMEM;
> +	}
> +
> +	/*
> +	 * If msi-parent property is present then setup APLIC MSI mode
> +	 * otherwise setup APLIC direct mode.
> +	 */
> +	if (fwnode_property_present(dev->fwnode, "msi-parent"))
Can this check be based on nr_idcs instead of checking for msi-parent
again?

Thanks!
Sunil
> +		rc = -ENODEV;
> +	else
> +		rc = aplic_direct_setup(dev, regs);
> +	if (rc) {
> +		dev_err(dev, "failed setup APLIC in %s mode\n",
> +			fwnode_property_present(dev->fwnode, "msi-parent") ?
> +			"MSI" : "direct");
> +		return rc;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id aplic_match[] = {
> +	{ .compatible = "riscv,aplic" },
> +	{}
> +};
> +
> +static struct platform_driver aplic_driver = {
> +	.driver = {
> +		.name		= "riscv-aplic",
> +		.of_match_table	= aplic_match,
> +	},
> +	.probe = aplic_probe,
> +};
> +
> +static int __init aplic_init(void)
> +{
> +	/*
> +	 * Register APLIC driver as early as possible so that APLIC
> +	 * platform device is probed as soon as it is created.
> +	 */
> +	return platform_driver_register(&aplic_driver);
> +}
> +core_initcall(aplic_init);
> diff --git a/drivers/irqchip/irq-riscv-aplic-main.h b/drivers/irqchip/irq-riscv-aplic-main.h
> new file mode 100644
> index 000000000000..474a04229334
> --- /dev/null
> +++ b/drivers/irqchip/irq-riscv-aplic-main.h
> @@ -0,0 +1,45 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> + * Copyright (C) 2022 Ventana Micro Systems Inc.
> + */
> +
> +#ifndef _IRQ_RISCV_APLIC_MAIN_H
> +#define _IRQ_RISCV_APLIC_MAIN_H
> +
> +#include <linux/device.h>
> +#include <linux/io.h>
> +#include <linux/irq.h>
> +#include <linux/irqdomain.h>
> +#include <linux/fwnode.h>
> +
> +#define APLIC_DEFAULT_PRIORITY		1
> +
> +struct aplic_msicfg {
> +	phys_addr_t		base_ppn;
> +	u32			hhxs;
> +	u32			hhxw;
> +	u32			lhxs;
> +	u32			lhxw;
> +};
> +
> +struct aplic_priv {
> +	struct device		*dev;
> +	u32			gsi_base;
> +	u32			nr_irqs;
> +	u32			nr_idcs;
> +	void __iomem		*regs;
> +	struct aplic_msicfg	msicfg;
> +};
> +
> +void aplic_irq_unmask(struct irq_data *d);
> +void aplic_irq_mask(struct irq_data *d);
> +int aplic_irq_set_type(struct irq_data *d, unsigned int type);
> +int aplic_irqdomain_translate(struct irq_fwspec *fwspec, u32 gsi_base,
> +			      unsigned long *hwirq, unsigned int *type);
> +void aplic_init_hw_global(struct aplic_priv *priv, bool msi_mode);
> +int aplic_setup_priv(struct aplic_priv *priv, struct device *dev,
> +		     void __iomem *regs);
> +int aplic_direct_setup(struct device *dev, void __iomem *regs);
> +
> +#endif
> diff --git a/include/linux/irqchip/riscv-aplic.h b/include/linux/irqchip/riscv-aplic.h
> new file mode 100644
> index 000000000000..97e198ea0109
> --- /dev/null
> +++ b/include/linux/irqchip/riscv-aplic.h
> @@ -0,0 +1,119 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> + * Copyright (C) 2022 Ventana Micro Systems Inc.
> + */
> +#ifndef __LINUX_IRQCHIP_RISCV_APLIC_H
> +#define __LINUX_IRQCHIP_RISCV_APLIC_H
> +
> +#include <linux/bitops.h>
> +
> +#define APLIC_MAX_IDC			BIT(14)
> +#define APLIC_MAX_SOURCE		1024
> +
> +#define APLIC_DOMAINCFG			0x0000
> +#define APLIC_DOMAINCFG_RDONLY		0x80000000
> +#define APLIC_DOMAINCFG_IE		BIT(8)
> +#define APLIC_DOMAINCFG_DM		BIT(2)
> +#define APLIC_DOMAINCFG_BE		BIT(0)
> +
> +#define APLIC_SOURCECFG_BASE		0x0004
> +#define APLIC_SOURCECFG_D		BIT(10)
> +#define APLIC_SOURCECFG_CHILDIDX_MASK	0x000003ff
> +#define APLIC_SOURCECFG_SM_MASK	0x00000007
> +#define APLIC_SOURCECFG_SM_INACTIVE	0x0
> +#define APLIC_SOURCECFG_SM_DETACH	0x1
> +#define APLIC_SOURCECFG_SM_EDGE_RISE	0x4
> +#define APLIC_SOURCECFG_SM_EDGE_FALL	0x5
> +#define APLIC_SOURCECFG_SM_LEVEL_HIGH	0x6
> +#define APLIC_SOURCECFG_SM_LEVEL_LOW	0x7
> +
> +#define APLIC_MMSICFGADDR		0x1bc0
> +#define APLIC_MMSICFGADDRH		0x1bc4
> +#define APLIC_SMSICFGADDR		0x1bc8
> +#define APLIC_SMSICFGADDRH		0x1bcc
> +
> +#ifdef CONFIG_RISCV_M_MODE
> +#define APLIC_xMSICFGADDR		APLIC_MMSICFGADDR
> +#define APLIC_xMSICFGADDRH		APLIC_MMSICFGADDRH
> +#else
> +#define APLIC_xMSICFGADDR		APLIC_SMSICFGADDR
> +#define APLIC_xMSICFGADDRH		APLIC_SMSICFGADDRH
> +#endif
> +
> +#define APLIC_xMSICFGADDRH_L		BIT(31)
> +#define APLIC_xMSICFGADDRH_HHXS_MASK	0x1f
> +#define APLIC_xMSICFGADDRH_HHXS_SHIFT	24
> +#define APLIC_xMSICFGADDRH_LHXS_MASK	0x7
> +#define APLIC_xMSICFGADDRH_LHXS_SHIFT	20
> +#define APLIC_xMSICFGADDRH_HHXW_MASK	0x7
> +#define APLIC_xMSICFGADDRH_HHXW_SHIFT	16
> +#define APLIC_xMSICFGADDRH_LHXW_MASK	0xf
> +#define APLIC_xMSICFGADDRH_LHXW_SHIFT	12
> +#define APLIC_xMSICFGADDRH_BAPPN_MASK	0xfff
> +
> +#define APLIC_xMSICFGADDR_PPN_SHIFT	12
> +
> +#define APLIC_xMSICFGADDR_PPN_HART(__lhxs) \
> +	(BIT(__lhxs) - 1)
> +
> +#define APLIC_xMSICFGADDR_PPN_LHX_MASK(__lhxw) \
> +	(BIT(__lhxw) - 1)
> +#define APLIC_xMSICFGADDR_PPN_LHX_SHIFT(__lhxs) \
> +	((__lhxs))
> +#define APLIC_xMSICFGADDR_PPN_LHX(__lhxw, __lhxs) \
> +	(APLIC_xMSICFGADDR_PPN_LHX_MASK(__lhxw) << \
> +	 APLIC_xMSICFGADDR_PPN_LHX_SHIFT(__lhxs))
> +
> +#define APLIC_xMSICFGADDR_PPN_HHX_MASK(__hhxw) \
> +	(BIT(__hhxw) - 1)
> +#define APLIC_xMSICFGADDR_PPN_HHX_SHIFT(__hhxs) \
> +	((__hhxs) + APLIC_xMSICFGADDR_PPN_SHIFT)
> +#define APLIC_xMSICFGADDR_PPN_HHX(__hhxw, __hhxs) \
> +	(APLIC_xMSICFGADDR_PPN_HHX_MASK(__hhxw) << \
> +	 APLIC_xMSICFGADDR_PPN_HHX_SHIFT(__hhxs))
> +
> +#define APLIC_IRQBITS_PER_REG		32
> +
> +#define APLIC_SETIP_BASE		0x1c00
> +#define APLIC_SETIPNUM			0x1cdc
> +
> +#define APLIC_CLRIP_BASE		0x1d00
> +#define APLIC_CLRIPNUM			0x1ddc
> +
> +#define APLIC_SETIE_BASE		0x1e00
> +#define APLIC_SETIENUM			0x1edc
> +
> +#define APLIC_CLRIE_BASE		0x1f00
> +#define APLIC_CLRIENUM			0x1fdc
> +
> +#define APLIC_SETIPNUM_LE		0x2000
> +#define APLIC_SETIPNUM_BE		0x2004
> +
> +#define APLIC_GENMSI			0x3000
> +
> +#define APLIC_TARGET_BASE		0x3004
> +#define APLIC_TARGET_HART_IDX_SHIFT	18
> +#define APLIC_TARGET_HART_IDX_MASK	0x3fff
> +#define APLIC_TARGET_GUEST_IDX_SHIFT	12
> +#define APLIC_TARGET_GUEST_IDX_MASK	0x3f
> +#define APLIC_TARGET_IPRIO_MASK	0xff
> +#define APLIC_TARGET_EIID_MASK	0x7ff
> +
> +#define APLIC_IDC_BASE			0x4000
> +#define APLIC_IDC_SIZE			32
> +
> +#define APLIC_IDC_IDELIVERY		0x00
> +
> +#define APLIC_IDC_IFORCE		0x04
> +
> +#define APLIC_IDC_ITHRESHOLD		0x08
> +
> +#define APLIC_IDC_TOPI			0x18
> +#define APLIC_IDC_TOPI_ID_SHIFT	16
> +#define APLIC_IDC_TOPI_ID_MASK	0x3ff
> +#define APLIC_IDC_TOPI_PRIO_MASK	0xff
> +
> +#define APLIC_IDC_CLAIMI		0x1c
> +
> +#endif
> -- 
> 2.34.1
> 

Re: [PATCH v8 13/16] irqchip: Add RISC-V advanced PLIC driver for direct-mode

[Sunil V L]

Hi Anup,

On Tue, Sep 12, 2023 at 11:19:25PM +0530, Anup Patel wrote:
> The RISC-V advanced interrupt architecture (AIA) specification defines
> advanced platform-level interrupt controller (APLIC) which has two modes
> of operation: 1) Direct mode and 2) MSI mode.
> (For more details, refer https://github.com/riscv/riscv-aia)
> 
> In APLIC direct-mode, wired interrupts are forwared to CPUs (or HARTs)
> as a local external interrupt.
> 
> We add a platform irqchip driver for the RISC-V APLIC direct-mode to
> support RISC-V platforms having only wired interrupts.
> 
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> ---
>  drivers/irqchip/Kconfig                  |   5 +
>  drivers/irqchip/Makefile                 |   1 +
>  drivers/irqchip/irq-riscv-aplic-direct.c | 326 +++++++++++++++++++++++
>  drivers/irqchip/irq-riscv-aplic-main.c   | 240 +++++++++++++++++
>  drivers/irqchip/irq-riscv-aplic-main.h   |  45 ++++
>  include/linux/irqchip/riscv-aplic.h      | 119 +++++++++
>  6 files changed, 736 insertions(+)
>  create mode 100644 drivers/irqchip/irq-riscv-aplic-direct.c
>  create mode 100644 drivers/irqchip/irq-riscv-aplic-main.c
>  create mode 100644 drivers/irqchip/irq-riscv-aplic-main.h
>  create mode 100644 include/linux/irqchip/riscv-aplic.h
> 
> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> index a6aad78076a0..44c455084d09 100644
> --- a/drivers/irqchip/Kconfig
> +++ b/drivers/irqchip/Kconfig
> @@ -545,6 +545,11 @@ config SIFIVE_PLIC
>  	select IRQ_DOMAIN_HIERARCHY
>  	select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
>  
> +config RISCV_APLIC
> +	bool
> +	depends on RISCV
> +	select IRQ_DOMAIN_HIERARCHY
> +
>  config RISCV_IMSIC
>  	bool
>  	depends on RISCV
> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index abca445a3229..7f8289790ed8 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -95,6 +95,7 @@ obj-$(CONFIG_QCOM_MPM)			+= irq-qcom-mpm.o
>  obj-$(CONFIG_CSKY_MPINTC)		+= irq-csky-mpintc.o
>  obj-$(CONFIG_CSKY_APB_INTC)		+= irq-csky-apb-intc.o
>  obj-$(CONFIG_RISCV_INTC)		+= irq-riscv-intc.o
> +obj-$(CONFIG_RISCV_APLIC)		+= irq-riscv-aplic-main.o irq-riscv-aplic-direct.o
>  obj-$(CONFIG_RISCV_IMSIC)		+= irq-riscv-imsic-state.o irq-riscv-imsic-early.o irq-riscv-imsic-platform.o
>  obj-$(CONFIG_SIFIVE_PLIC)		+= irq-sifive-plic.o
>  obj-$(CONFIG_IMX_IRQSTEER)		+= irq-imx-irqsteer.o
> diff --git a/drivers/irqchip/irq-riscv-aplic-direct.c b/drivers/irqchip/irq-riscv-aplic-direct.c
> new file mode 100644
> index 000000000000..e36d655a1490
> --- /dev/null
> +++ b/drivers/irqchip/irq-riscv-aplic-direct.c
> @@ -0,0 +1,326 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> + * Copyright (C) 2022 Ventana Micro Systems Inc.
> + */
> +
> +#include <linux/bitops.h>
> +#include <linux/cpu.h>
> +#include <linux/interrupt.h>
> +#include <linux/irqchip.h>
> +#include <linux/irqchip/chained_irq.h>
> +#include <linux/irqchip/riscv-aplic.h>
> +#include <linux/module.h>
> +#include <linux/of_address.h>
> +#include <linux/printk.h>
> +#include <linux/smp.h>
> +
> +#include "irq-riscv-aplic-main.h"
> +
> +#define APLIC_DISABLE_IDELIVERY		0
> +#define APLIC_ENABLE_IDELIVERY		1
> +#define APLIC_DISABLE_ITHRESHOLD	1
> +#define APLIC_ENABLE_ITHRESHOLD		0
> +
> +struct aplic_direct {
> +	struct aplic_priv	priv;
> +	struct irq_domain	*irqdomain;
> +	struct cpumask		lmask;
> +};
> +
> +struct aplic_idc {
> +	unsigned int		hart_index;
> +	void __iomem		*regs;
> +	struct aplic_direct	*direct;
> +};
> +
> +static unsigned int aplic_direct_parent_irq;
> +static DEFINE_PER_CPU(struct aplic_idc, aplic_idcs);
> +
> +static void aplic_direct_irq_eoi(struct irq_data *d)
> +{
> +	/*
> +	 * The fasteoi_handler requires irq_eoi() callback hence
> +	 * provide a dummy handler.
> +	 */
> +}
> +
> +#ifdef CONFIG_SMP
> +static int aplic_direct_set_affinity(struct irq_data *d,
> +				  const struct cpumask *mask_val, bool force)
> +{
> +	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
> +	struct aplic_direct *direct =
> +			container_of(priv, struct aplic_direct, priv);
> +	struct aplic_idc *idc;
> +	unsigned int cpu, val;
> +	struct cpumask amask;
> +	void __iomem *target;
> +
> +	cpumask_and(&amask, &direct->lmask, mask_val);
> +
> +	if (force)
> +		cpu = cpumask_first(&amask);
> +	else
> +		cpu = cpumask_any_and(&amask, cpu_online_mask);
> +
> +	if (cpu >= nr_cpu_ids)
> +		return -EINVAL;
> +
> +	idc = per_cpu_ptr(&aplic_idcs, cpu);
> +	target = priv->regs + APLIC_TARGET_BASE;
> +	target += (d->hwirq - 1) * sizeof(u32);
> +	val = idc->hart_index & APLIC_TARGET_HART_IDX_MASK;
> +	val <<= APLIC_TARGET_HART_IDX_SHIFT;
> +	val |= APLIC_DEFAULT_PRIORITY;
> +	writel(val, target);
> +
> +	irq_data_update_effective_affinity(d, cpumask_of(cpu));
> +
> +	return IRQ_SET_MASK_OK_DONE;
> +}
> +#endif
> +
> +static struct irq_chip aplic_direct_chip = {
> +	.name		= "APLIC-DIRECT",
> +	.irq_mask	= aplic_irq_mask,
> +	.irq_unmask	= aplic_irq_unmask,
> +	.irq_set_type	= aplic_irq_set_type,
> +	.irq_eoi	= aplic_direct_irq_eoi,
> +#ifdef CONFIG_SMP
> +	.irq_set_affinity = aplic_direct_set_affinity,
> +#endif
> +	.flags		= IRQCHIP_SET_TYPE_MASKED |
> +			  IRQCHIP_SKIP_SET_WAKE |
> +			  IRQCHIP_MASK_ON_SUSPEND,
> +};
> +
> +static int aplic_direct_irqdomain_translate(struct irq_domain *d,
> +					 struct irq_fwspec *fwspec,
> +					 unsigned long *hwirq,
> +					 unsigned int *type)
> +{
> +	struct aplic_priv *priv = d->host_data;
> +
> +	return aplic_irqdomain_translate(fwspec, priv->gsi_base,
> +					 hwirq, type);
> +}
> +
> +static int aplic_direct_irqdomain_alloc(struct irq_domain *domain,
> +				     unsigned int virq, unsigned int nr_irqs,
> +				     void *arg)
> +{
> +	int i, ret;
> +	unsigned int type;
> +	irq_hw_number_t hwirq;
> +	struct irq_fwspec *fwspec = arg;
> +	struct aplic_priv *priv = domain->host_data;
> +	struct aplic_direct *direct =
> +			container_of(priv, struct aplic_direct, priv);
> +
> +	ret = aplic_irqdomain_translate(fwspec, priv->gsi_base,
> +					&hwirq, &type);
> +	if (ret)
> +		return ret;
> +
> +	for (i = 0; i < nr_irqs; i++) {
> +		irq_domain_set_info(domain, virq + i, hwirq + i,
> +				    &aplic_direct_chip, priv,
> +				    handle_fasteoi_irq, NULL, NULL);
> +		irq_set_affinity(virq + i, &direct->lmask);
> +		/* See the reason described in aplic_msi_irqdomain_alloc() */
> +		irq_set_status_flags(virq + i, IRQ_DISABLE_UNLAZY);
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct irq_domain_ops aplic_direct_irqdomain_ops = {
> +	.translate	= aplic_direct_irqdomain_translate,
> +	.alloc		= aplic_direct_irqdomain_alloc,
> +	.free		= irq_domain_free_irqs_top,
> +};
> +
> +/*
> + * To handle an APLIC direct interrupts, we just read the CLAIMI register
> + * which will return highest priority pending interrupt and clear the
> + * pending bit of the interrupt. This process is repeated until CLAIMI
> + * register return zero value.
> + */
> +static void aplic_direct_handle_irq(struct irq_desc *desc)
> +{
> +	struct aplic_idc *idc = this_cpu_ptr(&aplic_idcs);
> +	struct irq_chip *chip = irq_desc_get_chip(desc);
> +	struct irq_domain *irqdomain = idc->direct->irqdomain;
> +	irq_hw_number_t hw_irq;
> +	int irq;
> +
> +	chained_irq_enter(chip, desc);
> +
> +	while ((hw_irq = readl(idc->regs + APLIC_IDC_CLAIMI))) {
> +		hw_irq = hw_irq >> APLIC_IDC_TOPI_ID_SHIFT;
> +		irq = irq_find_mapping(irqdomain, hw_irq);
> +
> +		if (unlikely(irq <= 0))
> +			dev_warn_ratelimited(idc->direct->priv.dev,
> +					     "hw_irq %lu mapping not found\n",
> +					     hw_irq);
> +		else
> +			generic_handle_irq(irq);
> +	}
> +
> +	chained_irq_exit(chip, desc);
> +}
> +
> +static void aplic_idc_set_delivery(struct aplic_idc *idc, bool en)
> +{
> +	u32 de = (en) ? APLIC_ENABLE_IDELIVERY : APLIC_DISABLE_IDELIVERY;
> +	u32 th = (en) ? APLIC_ENABLE_ITHRESHOLD : APLIC_DISABLE_ITHRESHOLD;
> +
> +	/* Priority must be less than threshold for interrupt triggering */
> +	writel(th, idc->regs + APLIC_IDC_ITHRESHOLD);
> +
> +	/* Delivery must be set to 1 for interrupt triggering */
> +	writel(de, idc->regs + APLIC_IDC_IDELIVERY);
> +}
> +
> +static int aplic_direct_dying_cpu(unsigned int cpu)
> +{
> +	if (aplic_direct_parent_irq)
> +		disable_percpu_irq(aplic_direct_parent_irq);
> +
> +	return 0;
> +}
> +
> +static int aplic_direct_starting_cpu(unsigned int cpu)
> +{
> +	if (aplic_direct_parent_irq)
> +		enable_percpu_irq(aplic_direct_parent_irq,
> +				irq_get_trigger_type(aplic_direct_parent_irq));
> +
> +	return 0;
> +}
> +
> +int aplic_direct_setup(struct device *dev, void __iomem *regs)
> +{
> +	int i, j, rc, cpu, setup_count = 0;
> +	struct fwnode_reference_args parent;
> +	struct aplic_direct *direct;
> +	struct aplic_priv *priv;
> +	struct irq_domain *domain;
> +	unsigned long hartid;
> +	struct aplic_idc *idc;
> +	u32 val;
> +
> +	direct = kzalloc(sizeof(*direct), GFP_KERNEL);
> +	if (!direct)
> +		return -ENOMEM;
> +	priv = &direct->priv;
> +
> +	rc = aplic_setup_priv(priv, dev, regs);
> +	if (rc) {
> +		dev_err(dev, "failed to create APLIC context\n");
> +		kfree(direct);
> +		return rc;
> +	}
> +
> +	/* Setup per-CPU IDC and target CPU mask */
> +	for (i = 0; i < priv->nr_idcs; i++) {
> +		rc = fwnode_property_get_reference_args(dev->fwnode,
> +				"interrupts-extended", "#interrupt-cells",
> +				0, i, &parent);
> +		if (rc) {
> +			dev_warn(dev, "parent irq for IDC%d not found\n", i);
> +			continue;
> +		}
> +
> +		/*
> +		 * Skip interrupts other than external interrupts for
> +		 * current privilege level.
> +		 */
> +		if (parent.args[0] != RV_IRQ_EXT)
> +			continue;
> +
> +		rc = riscv_get_intc_hartid(parent.fwnode, &hartid);
> +		if (rc) {
> +			dev_warn(dev, "invalid hartid for IDC%d\n", i);
> +			continue;
> +		}
> +
> +		cpu = riscv_hartid_to_cpuid(hartid);
> +		if (cpu < 0) {
> +			dev_warn(dev, "invalid cpuid for IDC%d\n", i);
> +			continue;
> +		}
> +
> +		cpumask_set_cpu(cpu, &direct->lmask);
> +
> +		idc = per_cpu_ptr(&aplic_idcs, cpu);
> +		idc->hart_index = i;
> +		idc->regs = priv->regs + APLIC_IDC_BASE + i * APLIC_IDC_SIZE;
> +		idc->direct = direct;
> +
> +		aplic_idc_set_delivery(idc, true);
> +
> +		/*
> +		 * Boot cpu might not have APLIC hart_index = 0 so check
> +		 * and update target registers of all interrupts.
> +		 */
> +		if (cpu == smp_processor_id() && idc->hart_index) {
> +			val = idc->hart_index & APLIC_TARGET_HART_IDX_MASK;
> +			val <<= APLIC_TARGET_HART_IDX_SHIFT;
> +			val |= APLIC_DEFAULT_PRIORITY;
> +			for (j = 1; j <= priv->nr_irqs; j++)
> +				writel(val, priv->regs + APLIC_TARGET_BASE +
> +					    (j - 1) * sizeof(u32));
> +		}
> +
> +		setup_count++;
> +	}
> +
> +	/* Find parent domain and register chained handler */
> +	domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
> +					  DOMAIN_BUS_ANY);
> +	if (!aplic_direct_parent_irq && domain) {
> +		aplic_direct_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT);
> +		if (aplic_direct_parent_irq) {
> +			irq_set_chained_handler(aplic_direct_parent_irq,
> +						aplic_direct_handle_irq);
> +
> +			/*
> +			 * Setup CPUHP notifier to enable parent
> +			 * interrupt on all CPUs
> +			 */
> +			cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
> +					  "irqchip/riscv/aplic:starting",
> +					  aplic_direct_starting_cpu,
> +					  aplic_direct_dying_cpu);
> +		}
> +	}
> +
> +	/* Fail if we were not able to setup IDC for any CPU */
> +	if (!setup_count) {
> +		kfree(direct);
> +		return -ENODEV;
> +	}
> +
> +	/* Setup global config and interrupt delivery */
> +	aplic_init_hw_global(priv, false);
> +
> +	/* Create irq domain instance for the APLIC */
> +	direct->irqdomain = irq_domain_create_linear(dev->fwnode,
> +						   priv->nr_irqs + 1,
> +						   &aplic_direct_irqdomain_ops,
> +						   priv);
> +	if (!direct->irqdomain) {
> +		dev_err(dev, "failed to create direct irq domain\n");
> +		kfree(direct);
> +		return -ENOMEM;
> +	}
> +
> +	/* Advertise the interrupt controller */
> +	dev_info(dev, "%d interrupts directly connected to %d CPUs\n",
> +		 priv->nr_irqs, priv->nr_idcs);
> +
> +	return 0;
> +}
> diff --git a/drivers/irqchip/irq-riscv-aplic-main.c b/drivers/irqchip/irq-riscv-aplic-main.c
> new file mode 100644
> index 000000000000..d62a096774c4
> --- /dev/null
> +++ b/drivers/irqchip/irq-riscv-aplic-main.c
> @@ -0,0 +1,240 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> + * Copyright (C) 2022 Ventana Micro Systems Inc.
> + */
> +
> +#include <linux/printk.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/irqchip/riscv-aplic.h>
> +
> +#include "irq-riscv-aplic-main.h"
> +
> +void aplic_irq_unmask(struct irq_data *d)
> +{
> +	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
> +
> +	writel(d->hwirq, priv->regs + APLIC_SETIENUM);
> +}
> +
> +void aplic_irq_mask(struct irq_data *d)
> +{
> +	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
> +
> +	writel(d->hwirq, priv->regs + APLIC_CLRIENUM);
> +}
> +
> +int aplic_irq_set_type(struct irq_data *d, unsigned int type)
> +{
> +	u32 val = 0;
> +	void __iomem *sourcecfg;
> +	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
> +
> +	switch (type) {
> +	case IRQ_TYPE_NONE:
> +		val = APLIC_SOURCECFG_SM_INACTIVE;
> +		break;
> +	case IRQ_TYPE_LEVEL_LOW:
> +		val = APLIC_SOURCECFG_SM_LEVEL_LOW;
> +		break;
> +	case IRQ_TYPE_LEVEL_HIGH:
> +		val = APLIC_SOURCECFG_SM_LEVEL_HIGH;
> +		break;
> +	case IRQ_TYPE_EDGE_FALLING:
> +		val = APLIC_SOURCECFG_SM_EDGE_FALL;
> +		break;
> +	case IRQ_TYPE_EDGE_RISING:
> +		val = APLIC_SOURCECFG_SM_EDGE_RISE;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	sourcecfg = priv->regs + APLIC_SOURCECFG_BASE;
> +	sourcecfg += (d->hwirq - 1) * sizeof(u32);
> +	writel(val, sourcecfg);
> +
> +	return 0;
> +}
> +
> +int aplic_irqdomain_translate(struct irq_fwspec *fwspec, u32 gsi_base,
> +			      unsigned long *hwirq, unsigned int *type)
> +{
> +	if (WARN_ON(fwspec->param_count < 2))
> +		return -EINVAL;
> +	if (WARN_ON(!fwspec->param[0]))
> +		return -EINVAL;
> +
> +	/* For DT, gsi_base is always zero. */
> +	*hwirq = fwspec->param[0] - gsi_base;
> +	*type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
> +
> +	WARN_ON(*type == IRQ_TYPE_NONE);
> +
> +	return 0;
> +}
> +
> +void aplic_init_hw_global(struct aplic_priv *priv, bool msi_mode)
> +{
> +	u32 val;
> +#ifdef CONFIG_RISCV_M_MODE
> +	u32 valH;
> +
> +	if (msi_mode) {
> +		val = priv->msicfg.base_ppn;
> +		valH = ((u64)priv->msicfg.base_ppn >> 32) &
> +			APLIC_xMSICFGADDRH_BAPPN_MASK;
> +		valH |= (priv->msicfg.lhxw & APLIC_xMSICFGADDRH_LHXW_MASK)
> +			<< APLIC_xMSICFGADDRH_LHXW_SHIFT;
> +		valH |= (priv->msicfg.hhxw & APLIC_xMSICFGADDRH_HHXW_MASK)
> +			<< APLIC_xMSICFGADDRH_HHXW_SHIFT;
> +		valH |= (priv->msicfg.lhxs & APLIC_xMSICFGADDRH_LHXS_MASK)
> +			<< APLIC_xMSICFGADDRH_LHXS_SHIFT;
> +		valH |= (priv->msicfg.hhxs & APLIC_xMSICFGADDRH_HHXS_MASK)
> +			<< APLIC_xMSICFGADDRH_HHXS_SHIFT;
> +		writel(val, priv->regs + APLIC_xMSICFGADDR);
> +		writel(valH, priv->regs + APLIC_xMSICFGADDRH);
> +	}
> +#endif
> +
> +	/* Setup APLIC domaincfg register */
> +	val = readl(priv->regs + APLIC_DOMAINCFG);
> +	val |= APLIC_DOMAINCFG_IE;
> +	if (msi_mode)
> +		val |= APLIC_DOMAINCFG_DM;
> +	writel(val, priv->regs + APLIC_DOMAINCFG);
> +	if (readl(priv->regs + APLIC_DOMAINCFG) != val)
> +		dev_warn(priv->dev, "unable to write 0x%x in domaincfg\n",
> +			 val);
> +}
> +
> +static void aplic_init_hw_irqs(struct aplic_priv *priv)
> +{
> +	int i;
> +
> +	/* Disable all interrupts */
> +	for (i = 0; i <= priv->nr_irqs; i += 32)
> +		writel(-1U, priv->regs + APLIC_CLRIE_BASE +
> +			    (i / 32) * sizeof(u32));
> +
> +	/* Set interrupt type and default priority for all interrupts */
> +	for (i = 1; i <= priv->nr_irqs; i++) {
> +		writel(0, priv->regs + APLIC_SOURCECFG_BASE +
> +			  (i - 1) * sizeof(u32));
> +		writel(APLIC_DEFAULT_PRIORITY,
> +		       priv->regs + APLIC_TARGET_BASE +
> +		       (i - 1) * sizeof(u32));
> +	}
> +
> +	/* Clear APLIC domaincfg */
> +	writel(0, priv->regs + APLIC_DOMAINCFG);
> +}
> +
> +int aplic_setup_priv(struct aplic_priv *priv, struct device *dev,
> +		     void __iomem *regs)
> +{
> +	struct fwnode_reference_args parent;
> +	int rc;
> +
> +	/* Save device pointer and register base */
> +	priv->dev = dev;
> +	priv->regs = regs;
> +
> +	/*
> +	 * Find out GSI base number
> +	 *
> +	 * Note: DT does not define "riscv,gsi-base" property so GSI
> +	 * base is always zero for DT.
> +	 */
> +	rc = fwnode_property_read_u32_array(dev->fwnode, "riscv,gsi-base",
> +					    &priv->gsi_base, 1);
For DT, you can just initialize this to 0 without reading the property.

> +	if (rc)
> +		priv->gsi_base = 0;
> +
> +	/* Find out number of interrupt sources */
> +	rc = fwnode_property_read_u32_array(dev->fwnode, "riscv,num-sources",
> +					    &priv->nr_irqs, 1);
> +	if (rc) {
> +		dev_err(dev, "failed to get number of interrupt sources\n");
> +		return rc;
> +	}
> +
> +	/* Setup initial state APLIC interrupts */
> +	aplic_init_hw_irqs(priv);
> +
> +	/*
> +	 * Find out number of IDCs based on parent interrupts
> +	 *
> +	 * If "msi-parent" property is present then we ignore the
> +	 * APLIC IDCs which forces the APLIC driver to use MSI mode.
> +	 */
> +	if (!fwnode_property_present(dev->fwnode, "msi-parent")) {
> +		while (!fwnode_property_get_reference_args(dev->fwnode,
> +				"interrupts-extended", "#interrupt-cells",
> +				0, priv->nr_idcs, &parent))
> +			priv->nr_idcs++;
> +	}
> +
Can this finding nr_idcs be done after aplic_init_hw_irqs() above?

> +	return 0;
> +}
> +
> +static int aplic_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct resource *res;
> +	void __iomem *regs;
> +	int rc;
> +
> +	/* Map the MMIO registers */
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!res) {
> +		dev_err(dev, "failed to get MMIO resource\n");
> +		return -EINVAL;
> +	}
> +	regs = devm_ioremap(&pdev->dev, res->start, resource_size(res));
> +	if (!regs) {
> +		dev_err(dev, "failed map MMIO registers\n");
> +		return -ENOMEM;
> +	}
> +
> +	/*
> +	 * If msi-parent property is present then setup APLIC MSI mode
> +	 * otherwise setup APLIC direct mode.
> +	 */
> +	if (fwnode_property_present(dev->fwnode, "msi-parent"))
Can this check be based on nr_idcs instead of checking for msi-parent
again?

Thanks!
Sunil
> +		rc = -ENODEV;
> +	else
> +		rc = aplic_direct_setup(dev, regs);
> +	if (rc) {
> +		dev_err(dev, "failed setup APLIC in %s mode\n",
> +			fwnode_property_present(dev->fwnode, "msi-parent") ?
> +			"MSI" : "direct");
> +		return rc;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id aplic_match[] = {
> +	{ .compatible = "riscv,aplic" },
> +	{}
> +};
> +
> +static struct platform_driver aplic_driver = {
> +	.driver = {
> +		.name		= "riscv-aplic",
> +		.of_match_table	= aplic_match,
> +	},
> +	.probe = aplic_probe,
> +};
> +
> +static int __init aplic_init(void)
> +{
> +	/*
> +	 * Register APLIC driver as early as possible so that APLIC
> +	 * platform device is probed as soon as it is created.
> +	 */
> +	return platform_driver_register(&aplic_driver);
> +}
> +core_initcall(aplic_init);
> diff --git a/drivers/irqchip/irq-riscv-aplic-main.h b/drivers/irqchip/irq-riscv-aplic-main.h
> new file mode 100644
> index 000000000000..474a04229334
> --- /dev/null
> +++ b/drivers/irqchip/irq-riscv-aplic-main.h
> @@ -0,0 +1,45 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> + * Copyright (C) 2022 Ventana Micro Systems Inc.
> + */
> +
> +#ifndef _IRQ_RISCV_APLIC_MAIN_H
> +#define _IRQ_RISCV_APLIC_MAIN_H
> +
> +#include <linux/device.h>
> +#include <linux/io.h>
> +#include <linux/irq.h>
> +#include <linux/irqdomain.h>
> +#include <linux/fwnode.h>
> +
> +#define APLIC_DEFAULT_PRIORITY		1
> +
> +struct aplic_msicfg {
> +	phys_addr_t		base_ppn;
> +	u32			hhxs;
> +	u32			hhxw;
> +	u32			lhxs;
> +	u32			lhxw;
> +};
> +
> +struct aplic_priv {
> +	struct device		*dev;
> +	u32			gsi_base;
> +	u32			nr_irqs;
> +	u32			nr_idcs;
> +	void __iomem		*regs;
> +	struct aplic_msicfg	msicfg;
> +};
> +
> +void aplic_irq_unmask(struct irq_data *d);
> +void aplic_irq_mask(struct irq_data *d);
> +int aplic_irq_set_type(struct irq_data *d, unsigned int type);
> +int aplic_irqdomain_translate(struct irq_fwspec *fwspec, u32 gsi_base,
> +			      unsigned long *hwirq, unsigned int *type);
> +void aplic_init_hw_global(struct aplic_priv *priv, bool msi_mode);
> +int aplic_setup_priv(struct aplic_priv *priv, struct device *dev,
> +		     void __iomem *regs);
> +int aplic_direct_setup(struct device *dev, void __iomem *regs);
> +
> +#endif
> diff --git a/include/linux/irqchip/riscv-aplic.h b/include/linux/irqchip/riscv-aplic.h
> new file mode 100644
> index 000000000000..97e198ea0109
> --- /dev/null
> +++ b/include/linux/irqchip/riscv-aplic.h
> @@ -0,0 +1,119 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> + * Copyright (C) 2022 Ventana Micro Systems Inc.
> + */
> +#ifndef __LINUX_IRQCHIP_RISCV_APLIC_H
> +#define __LINUX_IRQCHIP_RISCV_APLIC_H
> +
> +#include <linux/bitops.h>
> +
> +#define APLIC_MAX_IDC			BIT(14)
> +#define APLIC_MAX_SOURCE		1024
> +
> +#define APLIC_DOMAINCFG			0x0000
> +#define APLIC_DOMAINCFG_RDONLY		0x80000000
> +#define APLIC_DOMAINCFG_IE		BIT(8)
> +#define APLIC_DOMAINCFG_DM		BIT(2)
> +#define APLIC_DOMAINCFG_BE		BIT(0)
> +
> +#define APLIC_SOURCECFG_BASE		0x0004
> +#define APLIC_SOURCECFG_D		BIT(10)
> +#define APLIC_SOURCECFG_CHILDIDX_MASK	0x000003ff
> +#define APLIC_SOURCECFG_SM_MASK	0x00000007
> +#define APLIC_SOURCECFG_SM_INACTIVE	0x0
> +#define APLIC_SOURCECFG_SM_DETACH	0x1
> +#define APLIC_SOURCECFG_SM_EDGE_RISE	0x4
> +#define APLIC_SOURCECFG_SM_EDGE_FALL	0x5
> +#define APLIC_SOURCECFG_SM_LEVEL_HIGH	0x6
> +#define APLIC_SOURCECFG_SM_LEVEL_LOW	0x7
> +
> +#define APLIC_MMSICFGADDR		0x1bc0
> +#define APLIC_MMSICFGADDRH		0x1bc4
> +#define APLIC_SMSICFGADDR		0x1bc8
> +#define APLIC_SMSICFGADDRH		0x1bcc
> +
> +#ifdef CONFIG_RISCV_M_MODE
> +#define APLIC_xMSICFGADDR		APLIC_MMSICFGADDR
> +#define APLIC_xMSICFGADDRH		APLIC_MMSICFGADDRH
> +#else
> +#define APLIC_xMSICFGADDR		APLIC_SMSICFGADDR
> +#define APLIC_xMSICFGADDRH		APLIC_SMSICFGADDRH
> +#endif
> +
> +#define APLIC_xMSICFGADDRH_L		BIT(31)
> +#define APLIC_xMSICFGADDRH_HHXS_MASK	0x1f
> +#define APLIC_xMSICFGADDRH_HHXS_SHIFT	24
> +#define APLIC_xMSICFGADDRH_LHXS_MASK	0x7
> +#define APLIC_xMSICFGADDRH_LHXS_SHIFT	20
> +#define APLIC_xMSICFGADDRH_HHXW_MASK	0x7
> +#define APLIC_xMSICFGADDRH_HHXW_SHIFT	16
> +#define APLIC_xMSICFGADDRH_LHXW_MASK	0xf
> +#define APLIC_xMSICFGADDRH_LHXW_SHIFT	12
> +#define APLIC_xMSICFGADDRH_BAPPN_MASK	0xfff
> +
> +#define APLIC_xMSICFGADDR_PPN_SHIFT	12
> +
> +#define APLIC_xMSICFGADDR_PPN_HART(__lhxs) \
> +	(BIT(__lhxs) - 1)
> +
> +#define APLIC_xMSICFGADDR_PPN_LHX_MASK(__lhxw) \
> +	(BIT(__lhxw) - 1)
> +#define APLIC_xMSICFGADDR_PPN_LHX_SHIFT(__lhxs) \
> +	((__lhxs))
> +#define APLIC_xMSICFGADDR_PPN_LHX(__lhxw, __lhxs) \
> +	(APLIC_xMSICFGADDR_PPN_LHX_MASK(__lhxw) << \
> +	 APLIC_xMSICFGADDR_PPN_LHX_SHIFT(__lhxs))
> +
> +#define APLIC_xMSICFGADDR_PPN_HHX_MASK(__hhxw) \
> +	(BIT(__hhxw) - 1)
> +#define APLIC_xMSICFGADDR_PPN_HHX_SHIFT(__hhxs) \
> +	((__hhxs) + APLIC_xMSICFGADDR_PPN_SHIFT)
> +#define APLIC_xMSICFGADDR_PPN_HHX(__hhxw, __hhxs) \
> +	(APLIC_xMSICFGADDR_PPN_HHX_MASK(__hhxw) << \
> +	 APLIC_xMSICFGADDR_PPN_HHX_SHIFT(__hhxs))
> +
> +#define APLIC_IRQBITS_PER_REG		32
> +
> +#define APLIC_SETIP_BASE		0x1c00
> +#define APLIC_SETIPNUM			0x1cdc
> +
> +#define APLIC_CLRIP_BASE		0x1d00
> +#define APLIC_CLRIPNUM			0x1ddc
> +
> +#define APLIC_SETIE_BASE		0x1e00
> +#define APLIC_SETIENUM			0x1edc
> +
> +#define APLIC_CLRIE_BASE		0x1f00
> +#define APLIC_CLRIENUM			0x1fdc
> +
> +#define APLIC_SETIPNUM_LE		0x2000
> +#define APLIC_SETIPNUM_BE		0x2004
> +
> +#define APLIC_GENMSI			0x3000
> +
> +#define APLIC_TARGET_BASE		0x3004
> +#define APLIC_TARGET_HART_IDX_SHIFT	18
> +#define APLIC_TARGET_HART_IDX_MASK	0x3fff
> +#define APLIC_TARGET_GUEST_IDX_SHIFT	12
> +#define APLIC_TARGET_GUEST_IDX_MASK	0x3f
> +#define APLIC_TARGET_IPRIO_MASK	0xff
> +#define APLIC_TARGET_EIID_MASK	0x7ff
> +
> +#define APLIC_IDC_BASE			0x4000
> +#define APLIC_IDC_SIZE			32
> +
> +#define APLIC_IDC_IDELIVERY		0x00
> +
> +#define APLIC_IDC_IFORCE		0x04
> +
> +#define APLIC_IDC_ITHRESHOLD		0x08
> +
> +#define APLIC_IDC_TOPI			0x18
> +#define APLIC_IDC_TOPI_ID_SHIFT	16
> +#define APLIC_IDC_TOPI_ID_MASK	0x3ff
> +#define APLIC_IDC_TOPI_PRIO_MASK	0xff
> +
> +#define APLIC_IDC_CLAIMI		0x1c
> +
> +#endif
> -- 
> 2.34.1
> 

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Re: [PATCH v8 13/16] irqchip: Add RISC-V advanced PLIC driver for direct-mode

[Sunil V L]

On Mon, Sep 25, 2023 at 01:26:17PM +0530, Sunil V L wrote:
> Hi Anup,
> 
> On Tue, Sep 12, 2023 at 11:19:25PM +0530, Anup Patel wrote:
> > The RISC-V advanced interrupt architecture (AIA) specification defines
> > advanced platform-level interrupt controller (APLIC) which has two modes
> > of operation: 1) Direct mode and 2) MSI mode.
> > (For more details, refer https://github.com/riscv/riscv-aia)
> > 
> > In APLIC direct-mode, wired interrupts are forwared to CPUs (or HARTs)
> > as a local external interrupt.
> > 
> > We add a platform irqchip driver for the RISC-V APLIC direct-mode to
> > support RISC-V platforms having only wired interrupts.
> > 
> > Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> > ---
> >  drivers/irqchip/Kconfig                  |   5 +
> >  drivers/irqchip/Makefile                 |   1 +
> >  drivers/irqchip/irq-riscv-aplic-direct.c | 326 +++++++++++++++++++++++
> >  drivers/irqchip/irq-riscv-aplic-main.c   | 240 +++++++++++++++++
> >  drivers/irqchip/irq-riscv-aplic-main.h   |  45 ++++
> >  include/linux/irqchip/riscv-aplic.h      | 119 +++++++++
> >  6 files changed, 736 insertions(+)
> >  create mode 100644 drivers/irqchip/irq-riscv-aplic-direct.c
> >  create mode 100644 drivers/irqchip/irq-riscv-aplic-main.c
> >  create mode 100644 drivers/irqchip/irq-riscv-aplic-main.h
> >  create mode 100644 include/linux/irqchip/riscv-aplic.h
> > 
> > diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> > index a6aad78076a0..44c455084d09 100644
> > --- a/drivers/irqchip/Kconfig
> > +++ b/drivers/irqchip/Kconfig
> > @@ -545,6 +545,11 @@ config SIFIVE_PLIC
> >  	select IRQ_DOMAIN_HIERARCHY
> >  	select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
> >  
> > +config RISCV_APLIC
> > +	bool
> > +	depends on RISCV
> > +	select IRQ_DOMAIN_HIERARCHY
> > +
> >  config RISCV_IMSIC
> >  	bool
> >  	depends on RISCV
> > diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> > index abca445a3229..7f8289790ed8 100644
> > --- a/drivers/irqchip/Makefile
> > +++ b/drivers/irqchip/Makefile
> > @@ -95,6 +95,7 @@ obj-$(CONFIG_QCOM_MPM)			+= irq-qcom-mpm.o
> >  obj-$(CONFIG_CSKY_MPINTC)		+= irq-csky-mpintc.o
> >  obj-$(CONFIG_CSKY_APB_INTC)		+= irq-csky-apb-intc.o
> >  obj-$(CONFIG_RISCV_INTC)		+= irq-riscv-intc.o
> > +obj-$(CONFIG_RISCV_APLIC)		+= irq-riscv-aplic-main.o irq-riscv-aplic-direct.o
> >  obj-$(CONFIG_RISCV_IMSIC)		+= irq-riscv-imsic-state.o irq-riscv-imsic-early.o irq-riscv-imsic-platform.o
> >  obj-$(CONFIG_SIFIVE_PLIC)		+= irq-sifive-plic.o
> >  obj-$(CONFIG_IMX_IRQSTEER)		+= irq-imx-irqsteer.o
> > diff --git a/drivers/irqchip/irq-riscv-aplic-direct.c b/drivers/irqchip/irq-riscv-aplic-direct.c
> > new file mode 100644
> > index 000000000000..e36d655a1490
> > --- /dev/null
> > +++ b/drivers/irqchip/irq-riscv-aplic-direct.c
> > @@ -0,0 +1,326 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +
> > +#include <linux/bitops.h>
> > +#include <linux/cpu.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/irqchip.h>
> > +#include <linux/irqchip/chained_irq.h>
> > +#include <linux/irqchip/riscv-aplic.h>
> > +#include <linux/module.h>
> > +#include <linux/of_address.h>
> > +#include <linux/printk.h>
> > +#include <linux/smp.h>
> > +
> > +#include "irq-riscv-aplic-main.h"
> > +
> > +#define APLIC_DISABLE_IDELIVERY		0
> > +#define APLIC_ENABLE_IDELIVERY		1
> > +#define APLIC_DISABLE_ITHRESHOLD	1
> > +#define APLIC_ENABLE_ITHRESHOLD		0
> > +
> > +struct aplic_direct {
> > +	struct aplic_priv	priv;
> > +	struct irq_domain	*irqdomain;
> > +	struct cpumask		lmask;
> > +};
> > +
> > +struct aplic_idc {
> > +	unsigned int		hart_index;
> > +	void __iomem		*regs;
> > +	struct aplic_direct	*direct;
> > +};
> > +
> > +static unsigned int aplic_direct_parent_irq;
> > +static DEFINE_PER_CPU(struct aplic_idc, aplic_idcs);
> > +
> > +static void aplic_direct_irq_eoi(struct irq_data *d)
> > +{
> > +	/*
> > +	 * The fasteoi_handler requires irq_eoi() callback hence
> > +	 * provide a dummy handler.
> > +	 */
> > +}
> > +
> > +#ifdef CONFIG_SMP
> > +static int aplic_direct_set_affinity(struct irq_data *d,
> > +				  const struct cpumask *mask_val, bool force)
> > +{
> > +	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
> > +	struct aplic_direct *direct =
> > +			container_of(priv, struct aplic_direct, priv);
> > +	struct aplic_idc *idc;
> > +	unsigned int cpu, val;
> > +	struct cpumask amask;
> > +	void __iomem *target;
> > +
> > +	cpumask_and(&amask, &direct->lmask, mask_val);
> > +
> > +	if (force)
> > +		cpu = cpumask_first(&amask);
> > +	else
> > +		cpu = cpumask_any_and(&amask, cpu_online_mask);
> > +
> > +	if (cpu >= nr_cpu_ids)
> > +		return -EINVAL;
> > +
> > +	idc = per_cpu_ptr(&aplic_idcs, cpu);
> > +	target = priv->regs + APLIC_TARGET_BASE;
> > +	target += (d->hwirq - 1) * sizeof(u32);
> > +	val = idc->hart_index & APLIC_TARGET_HART_IDX_MASK;
> > +	val <<= APLIC_TARGET_HART_IDX_SHIFT;
> > +	val |= APLIC_DEFAULT_PRIORITY;
> > +	writel(val, target);
> > +
> > +	irq_data_update_effective_affinity(d, cpumask_of(cpu));
> > +
> > +	return IRQ_SET_MASK_OK_DONE;
> > +}
> > +#endif
> > +
> > +static struct irq_chip aplic_direct_chip = {
> > +	.name		= "APLIC-DIRECT",
> > +	.irq_mask	= aplic_irq_mask,
> > +	.irq_unmask	= aplic_irq_unmask,
> > +	.irq_set_type	= aplic_irq_set_type,
> > +	.irq_eoi	= aplic_direct_irq_eoi,
> > +#ifdef CONFIG_SMP
> > +	.irq_set_affinity = aplic_direct_set_affinity,
> > +#endif
> > +	.flags		= IRQCHIP_SET_TYPE_MASKED |
> > +			  IRQCHIP_SKIP_SET_WAKE |
> > +			  IRQCHIP_MASK_ON_SUSPEND,
> > +};
> > +
> > +static int aplic_direct_irqdomain_translate(struct irq_domain *d,
> > +					 struct irq_fwspec *fwspec,
> > +					 unsigned long *hwirq,
> > +					 unsigned int *type)
> > +{
> > +	struct aplic_priv *priv = d->host_data;
> > +
> > +	return aplic_irqdomain_translate(fwspec, priv->gsi_base,
> > +					 hwirq, type);
> > +}
> > +
> > +static int aplic_direct_irqdomain_alloc(struct irq_domain *domain,
> > +				     unsigned int virq, unsigned int nr_irqs,
> > +				     void *arg)
> > +{
> > +	int i, ret;
> > +	unsigned int type;
> > +	irq_hw_number_t hwirq;
> > +	struct irq_fwspec *fwspec = arg;
> > +	struct aplic_priv *priv = domain->host_data;
> > +	struct aplic_direct *direct =
> > +			container_of(priv, struct aplic_direct, priv);
> > +
> > +	ret = aplic_irqdomain_translate(fwspec, priv->gsi_base,
> > +					&hwirq, &type);
> > +	if (ret)
> > +		return ret;
> > +
> > +	for (i = 0; i < nr_irqs; i++) {
> > +		irq_domain_set_info(domain, virq + i, hwirq + i,
> > +				    &aplic_direct_chip, priv,
> > +				    handle_fasteoi_irq, NULL, NULL);
> > +		irq_set_affinity(virq + i, &direct->lmask);
> > +		/* See the reason described in aplic_msi_irqdomain_alloc() */
> > +		irq_set_status_flags(virq + i, IRQ_DISABLE_UNLAZY);
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct irq_domain_ops aplic_direct_irqdomain_ops = {
> > +	.translate	= aplic_direct_irqdomain_translate,
> > +	.alloc		= aplic_direct_irqdomain_alloc,
> > +	.free		= irq_domain_free_irqs_top,
> > +};
> > +
> > +/*
> > + * To handle an APLIC direct interrupts, we just read the CLAIMI register
> > + * which will return highest priority pending interrupt and clear the
> > + * pending bit of the interrupt. This process is repeated until CLAIMI
> > + * register return zero value.
> > + */
> > +static void aplic_direct_handle_irq(struct irq_desc *desc)
> > +{
> > +	struct aplic_idc *idc = this_cpu_ptr(&aplic_idcs);
> > +	struct irq_chip *chip = irq_desc_get_chip(desc);
> > +	struct irq_domain *irqdomain = idc->direct->irqdomain;
> > +	irq_hw_number_t hw_irq;
> > +	int irq;
> > +
> > +	chained_irq_enter(chip, desc);
> > +
> > +	while ((hw_irq = readl(idc->regs + APLIC_IDC_CLAIMI))) {
> > +		hw_irq = hw_irq >> APLIC_IDC_TOPI_ID_SHIFT;
> > +		irq = irq_find_mapping(irqdomain, hw_irq);
> > +
> > +		if (unlikely(irq <= 0))
> > +			dev_warn_ratelimited(idc->direct->priv.dev,
> > +					     "hw_irq %lu mapping not found\n",
> > +					     hw_irq);
> > +		else
> > +			generic_handle_irq(irq);
> > +	}
> > +
> > +	chained_irq_exit(chip, desc);
> > +}
> > +
> > +static void aplic_idc_set_delivery(struct aplic_idc *idc, bool en)
> > +{
> > +	u32 de = (en) ? APLIC_ENABLE_IDELIVERY : APLIC_DISABLE_IDELIVERY;
> > +	u32 th = (en) ? APLIC_ENABLE_ITHRESHOLD : APLIC_DISABLE_ITHRESHOLD;
> > +
> > +	/* Priority must be less than threshold for interrupt triggering */
> > +	writel(th, idc->regs + APLIC_IDC_ITHRESHOLD);
> > +
> > +	/* Delivery must be set to 1 for interrupt triggering */
> > +	writel(de, idc->regs + APLIC_IDC_IDELIVERY);
> > +}
> > +
> > +static int aplic_direct_dying_cpu(unsigned int cpu)
> > +{
> > +	if (aplic_direct_parent_irq)
> > +		disable_percpu_irq(aplic_direct_parent_irq);
> > +
> > +	return 0;
> > +}
> > +
> > +static int aplic_direct_starting_cpu(unsigned int cpu)
> > +{
> > +	if (aplic_direct_parent_irq)
> > +		enable_percpu_irq(aplic_direct_parent_irq,
> > +				irq_get_trigger_type(aplic_direct_parent_irq));
> > +
> > +	return 0;
> > +}
> > +
> > +int aplic_direct_setup(struct device *dev, void __iomem *regs)
> > +{
> > +	int i, j, rc, cpu, setup_count = 0;
> > +	struct fwnode_reference_args parent;
> > +	struct aplic_direct *direct;
> > +	struct aplic_priv *priv;
> > +	struct irq_domain *domain;
> > +	unsigned long hartid;
> > +	struct aplic_idc *idc;
> > +	u32 val;
> > +
> > +	direct = kzalloc(sizeof(*direct), GFP_KERNEL);
> > +	if (!direct)
> > +		return -ENOMEM;
> > +	priv = &direct->priv;
> > +
> > +	rc = aplic_setup_priv(priv, dev, regs);
> > +	if (rc) {
> > +		dev_err(dev, "failed to create APLIC context\n");
> > +		kfree(direct);
> > +		return rc;
> > +	}
> > +
> > +	/* Setup per-CPU IDC and target CPU mask */
> > +	for (i = 0; i < priv->nr_idcs; i++) {
> > +		rc = fwnode_property_get_reference_args(dev->fwnode,
> > +				"interrupts-extended", "#interrupt-cells",
> > +				0, i, &parent);
> > +		if (rc) {
> > +			dev_warn(dev, "parent irq for IDC%d not found\n", i);
> > +			continue;
> > +		}
> > +
> > +		/*
> > +		 * Skip interrupts other than external interrupts for
> > +		 * current privilege level.
> > +		 */
> > +		if (parent.args[0] != RV_IRQ_EXT)
> > +			continue;
> > +
> > +		rc = riscv_get_intc_hartid(parent.fwnode, &hartid);
> > +		if (rc) {
> > +			dev_warn(dev, "invalid hartid for IDC%d\n", i);
> > +			continue;
> > +		}
> > +
> > +		cpu = riscv_hartid_to_cpuid(hartid);
> > +		if (cpu < 0) {
> > +			dev_warn(dev, "invalid cpuid for IDC%d\n", i);
> > +			continue;
> > +		}
> > +
> > +		cpumask_set_cpu(cpu, &direct->lmask);
> > +
> > +		idc = per_cpu_ptr(&aplic_idcs, cpu);
> > +		idc->hart_index = i;
> > +		idc->regs = priv->regs + APLIC_IDC_BASE + i * APLIC_IDC_SIZE;
> > +		idc->direct = direct;
> > +
> > +		aplic_idc_set_delivery(idc, true);
> > +
> > +		/*
> > +		 * Boot cpu might not have APLIC hart_index = 0 so check
> > +		 * and update target registers of all interrupts.
> > +		 */
> > +		if (cpu == smp_processor_id() && idc->hart_index) {
> > +			val = idc->hart_index & APLIC_TARGET_HART_IDX_MASK;
> > +			val <<= APLIC_TARGET_HART_IDX_SHIFT;
> > +			val |= APLIC_DEFAULT_PRIORITY;
> > +			for (j = 1; j <= priv->nr_irqs; j++)
> > +				writel(val, priv->regs + APLIC_TARGET_BASE +
> > +					    (j - 1) * sizeof(u32));
> > +		}
> > +
> > +		setup_count++;
> > +	}
> > +
> > +	/* Find parent domain and register chained handler */
> > +	domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
> > +					  DOMAIN_BUS_ANY);
> > +	if (!aplic_direct_parent_irq && domain) {
> > +		aplic_direct_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT);
> > +		if (aplic_direct_parent_irq) {
> > +			irq_set_chained_handler(aplic_direct_parent_irq,
> > +						aplic_direct_handle_irq);
> > +
> > +			/*
> > +			 * Setup CPUHP notifier to enable parent
> > +			 * interrupt on all CPUs
> > +			 */
> > +			cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
> > +					  "irqchip/riscv/aplic:starting",
> > +					  aplic_direct_starting_cpu,
> > +					  aplic_direct_dying_cpu);
> > +		}
> > +	}
> > +
> > +	/* Fail if we were not able to setup IDC for any CPU */
> > +	if (!setup_count) {
> > +		kfree(direct);
> > +		return -ENODEV;
> > +	}
> > +
> > +	/* Setup global config and interrupt delivery */
> > +	aplic_init_hw_global(priv, false);
> > +
> > +	/* Create irq domain instance for the APLIC */
> > +	direct->irqdomain = irq_domain_create_linear(dev->fwnode,
> > +						   priv->nr_irqs + 1,
> > +						   &aplic_direct_irqdomain_ops,
> > +						   priv);
> > +	if (!direct->irqdomain) {
> > +		dev_err(dev, "failed to create direct irq domain\n");
> > +		kfree(direct);
> > +		return -ENOMEM;
> > +	}
> > +
> > +	/* Advertise the interrupt controller */
> > +	dev_info(dev, "%d interrupts directly connected to %d CPUs\n",
> > +		 priv->nr_irqs, priv->nr_idcs);
> > +
> > +	return 0;
> > +}
> > diff --git a/drivers/irqchip/irq-riscv-aplic-main.c b/drivers/irqchip/irq-riscv-aplic-main.c
> > new file mode 100644
> > index 000000000000..d62a096774c4
> > --- /dev/null
> > +++ b/drivers/irqchip/irq-riscv-aplic-main.c
> > @@ -0,0 +1,240 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +
> > +#include <linux/printk.h>
> > +#include <linux/module.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/irqchip/riscv-aplic.h>
> > +
> > +#include "irq-riscv-aplic-main.h"
> > +
> > +void aplic_irq_unmask(struct irq_data *d)
> > +{
> > +	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
> > +
> > +	writel(d->hwirq, priv->regs + APLIC_SETIENUM);
> > +}
> > +
> > +void aplic_irq_mask(struct irq_data *d)
> > +{
> > +	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
> > +
> > +	writel(d->hwirq, priv->regs + APLIC_CLRIENUM);
> > +}
> > +
> > +int aplic_irq_set_type(struct irq_data *d, unsigned int type)
> > +{
> > +	u32 val = 0;
> > +	void __iomem *sourcecfg;
> > +	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
> > +
> > +	switch (type) {
> > +	case IRQ_TYPE_NONE:
> > +		val = APLIC_SOURCECFG_SM_INACTIVE;
> > +		break;
> > +	case IRQ_TYPE_LEVEL_LOW:
> > +		val = APLIC_SOURCECFG_SM_LEVEL_LOW;
> > +		break;
> > +	case IRQ_TYPE_LEVEL_HIGH:
> > +		val = APLIC_SOURCECFG_SM_LEVEL_HIGH;
> > +		break;
> > +	case IRQ_TYPE_EDGE_FALLING:
> > +		val = APLIC_SOURCECFG_SM_EDGE_FALL;
> > +		break;
> > +	case IRQ_TYPE_EDGE_RISING:
> > +		val = APLIC_SOURCECFG_SM_EDGE_RISE;
> > +		break;
> > +	default:
> > +		return -EINVAL;
> > +	}
> > +
> > +	sourcecfg = priv->regs + APLIC_SOURCECFG_BASE;
> > +	sourcecfg += (d->hwirq - 1) * sizeof(u32);
> > +	writel(val, sourcecfg);
> > +
> > +	return 0;
> > +}
> > +
> > +int aplic_irqdomain_translate(struct irq_fwspec *fwspec, u32 gsi_base,
> > +			      unsigned long *hwirq, unsigned int *type)
> > +{
> > +	if (WARN_ON(fwspec->param_count < 2))
> > +		return -EINVAL;
> > +	if (WARN_ON(!fwspec->param[0]))
> > +		return -EINVAL;
> > +
> > +	/* For DT, gsi_base is always zero. */
> > +	*hwirq = fwspec->param[0] - gsi_base;
> > +	*type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
> > +
> > +	WARN_ON(*type == IRQ_TYPE_NONE);
> > +
> > +	return 0;
> > +}
> > +
> > +void aplic_init_hw_global(struct aplic_priv *priv, bool msi_mode)
> > +{
> > +	u32 val;
> > +#ifdef CONFIG_RISCV_M_MODE
> > +	u32 valH;
> > +
> > +	if (msi_mode) {
> > +		val = priv->msicfg.base_ppn;
> > +		valH = ((u64)priv->msicfg.base_ppn >> 32) &
> > +			APLIC_xMSICFGADDRH_BAPPN_MASK;
> > +		valH |= (priv->msicfg.lhxw & APLIC_xMSICFGADDRH_LHXW_MASK)
> > +			<< APLIC_xMSICFGADDRH_LHXW_SHIFT;
> > +		valH |= (priv->msicfg.hhxw & APLIC_xMSICFGADDRH_HHXW_MASK)
> > +			<< APLIC_xMSICFGADDRH_HHXW_SHIFT;
> > +		valH |= (priv->msicfg.lhxs & APLIC_xMSICFGADDRH_LHXS_MASK)
> > +			<< APLIC_xMSICFGADDRH_LHXS_SHIFT;
> > +		valH |= (priv->msicfg.hhxs & APLIC_xMSICFGADDRH_HHXS_MASK)
> > +			<< APLIC_xMSICFGADDRH_HHXS_SHIFT;
> > +		writel(val, priv->regs + APLIC_xMSICFGADDR);
> > +		writel(valH, priv->regs + APLIC_xMSICFGADDRH);
> > +	}
> > +#endif
> > +
> > +	/* Setup APLIC domaincfg register */
> > +	val = readl(priv->regs + APLIC_DOMAINCFG);
> > +	val |= APLIC_DOMAINCFG_IE;
> > +	if (msi_mode)
> > +		val |= APLIC_DOMAINCFG_DM;
> > +	writel(val, priv->regs + APLIC_DOMAINCFG);
> > +	if (readl(priv->regs + APLIC_DOMAINCFG) != val)
> > +		dev_warn(priv->dev, "unable to write 0x%x in domaincfg\n",
> > +			 val);
> > +}
> > +
> > +static void aplic_init_hw_irqs(struct aplic_priv *priv)
> > +{
> > +	int i;
> > +
> > +	/* Disable all interrupts */
> > +	for (i = 0; i <= priv->nr_irqs; i += 32)
> > +		writel(-1U, priv->regs + APLIC_CLRIE_BASE +
> > +			    (i / 32) * sizeof(u32));
> > +
> > +	/* Set interrupt type and default priority for all interrupts */
> > +	for (i = 1; i <= priv->nr_irqs; i++) {
> > +		writel(0, priv->regs + APLIC_SOURCECFG_BASE +
> > +			  (i - 1) * sizeof(u32));
> > +		writel(APLIC_DEFAULT_PRIORITY,
> > +		       priv->regs + APLIC_TARGET_BASE +
> > +		       (i - 1) * sizeof(u32));
> > +	}
> > +
> > +	/* Clear APLIC domaincfg */
> > +	writel(0, priv->regs + APLIC_DOMAINCFG);
> > +}
> > +
> > +int aplic_setup_priv(struct aplic_priv *priv, struct device *dev,
> > +		     void __iomem *regs)
> > +{
> > +	struct fwnode_reference_args parent;
> > +	int rc;
> > +
> > +	/* Save device pointer and register base */
> > +	priv->dev = dev;
> > +	priv->regs = regs;
> > +
> > +	/*
> > +	 * Find out GSI base number
> > +	 *
> > +	 * Note: DT does not define "riscv,gsi-base" property so GSI
> > +	 * base is always zero for DT.
> > +	 */
> > +	rc = fwnode_property_read_u32_array(dev->fwnode, "riscv,gsi-base",
> > +					    &priv->gsi_base, 1);
> For DT, you can just initialize this to 0 without reading the property.
> 
> > +	if (rc)
> > +		priv->gsi_base = 0;
> > +
> > +	/* Find out number of interrupt sources */
> > +	rc = fwnode_property_read_u32_array(dev->fwnode, "riscv,num-sources",
> > +					    &priv->nr_irqs, 1);
> > +	if (rc) {
> > +		dev_err(dev, "failed to get number of interrupt sources\n");
> > +		return rc;
> > +	}
> > +
> > +	/* Setup initial state APLIC interrupts */
> > +	aplic_init_hw_irqs(priv);
> > +
> > +	/*
> > +	 * Find out number of IDCs based on parent interrupts
> > +	 *
> > +	 * If "msi-parent" property is present then we ignore the
> > +	 * APLIC IDCs which forces the APLIC driver to use MSI mode.
> > +	 */
> > +	if (!fwnode_property_present(dev->fwnode, "msi-parent")) {
> > +		while (!fwnode_property_get_reference_args(dev->fwnode,
> > +				"interrupts-extended", "#interrupt-cells",
> > +				0, priv->nr_idcs, &parent))
> > +			priv->nr_idcs++;
> > +	}
> > +
> Can this finding nr_idcs be done after aplic_init_hw_irqs() above?
> 
Sorry, I meant prior to calling aplic_init_hw_irqs().

Thanks,
Sunl

Re: [PATCH v8 13/16] irqchip: Add RISC-V advanced PLIC driver for direct-mode

[Sunil V L]

On Mon, Sep 25, 2023 at 01:26:17PM +0530, Sunil V L wrote:
> Hi Anup,
> 
> On Tue, Sep 12, 2023 at 11:19:25PM +0530, Anup Patel wrote:
> > The RISC-V advanced interrupt architecture (AIA) specification defines
> > advanced platform-level interrupt controller (APLIC) which has two modes
> > of operation: 1) Direct mode and 2) MSI mode.
> > (For more details, refer https://github.com/riscv/riscv-aia)
> > 
> > In APLIC direct-mode, wired interrupts are forwared to CPUs (or HARTs)
> > as a local external interrupt.
> > 
> > We add a platform irqchip driver for the RISC-V APLIC direct-mode to
> > support RISC-V platforms having only wired interrupts.
> > 
> > Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> > ---
> >  drivers/irqchip/Kconfig                  |   5 +
> >  drivers/irqchip/Makefile                 |   1 +
> >  drivers/irqchip/irq-riscv-aplic-direct.c | 326 +++++++++++++++++++++++
> >  drivers/irqchip/irq-riscv-aplic-main.c   | 240 +++++++++++++++++
> >  drivers/irqchip/irq-riscv-aplic-main.h   |  45 ++++
> >  include/linux/irqchip/riscv-aplic.h      | 119 +++++++++
> >  6 files changed, 736 insertions(+)
> >  create mode 100644 drivers/irqchip/irq-riscv-aplic-direct.c
> >  create mode 100644 drivers/irqchip/irq-riscv-aplic-main.c
> >  create mode 100644 drivers/irqchip/irq-riscv-aplic-main.h
> >  create mode 100644 include/linux/irqchip/riscv-aplic.h
> > 
> > diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> > index a6aad78076a0..44c455084d09 100644
> > --- a/drivers/irqchip/Kconfig
> > +++ b/drivers/irqchip/Kconfig
> > @@ -545,6 +545,11 @@ config SIFIVE_PLIC
> >  	select IRQ_DOMAIN_HIERARCHY
> >  	select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
> >  
> > +config RISCV_APLIC
> > +	bool
> > +	depends on RISCV
> > +	select IRQ_DOMAIN_HIERARCHY
> > +
> >  config RISCV_IMSIC
> >  	bool
> >  	depends on RISCV
> > diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> > index abca445a3229..7f8289790ed8 100644
> > --- a/drivers/irqchip/Makefile
> > +++ b/drivers/irqchip/Makefile
> > @@ -95,6 +95,7 @@ obj-$(CONFIG_QCOM_MPM)			+= irq-qcom-mpm.o
> >  obj-$(CONFIG_CSKY_MPINTC)		+= irq-csky-mpintc.o
> >  obj-$(CONFIG_CSKY_APB_INTC)		+= irq-csky-apb-intc.o
> >  obj-$(CONFIG_RISCV_INTC)		+= irq-riscv-intc.o
> > +obj-$(CONFIG_RISCV_APLIC)		+= irq-riscv-aplic-main.o irq-riscv-aplic-direct.o
> >  obj-$(CONFIG_RISCV_IMSIC)		+= irq-riscv-imsic-state.o irq-riscv-imsic-early.o irq-riscv-imsic-platform.o
> >  obj-$(CONFIG_SIFIVE_PLIC)		+= irq-sifive-plic.o
> >  obj-$(CONFIG_IMX_IRQSTEER)		+= irq-imx-irqsteer.o
> > diff --git a/drivers/irqchip/irq-riscv-aplic-direct.c b/drivers/irqchip/irq-riscv-aplic-direct.c
> > new file mode 100644
> > index 000000000000..e36d655a1490
> > --- /dev/null
> > +++ b/drivers/irqchip/irq-riscv-aplic-direct.c
> > @@ -0,0 +1,326 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +
> > +#include <linux/bitops.h>
> > +#include <linux/cpu.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/irqchip.h>
> > +#include <linux/irqchip/chained_irq.h>
> > +#include <linux/irqchip/riscv-aplic.h>
> > +#include <linux/module.h>
> > +#include <linux/of_address.h>
> > +#include <linux/printk.h>
> > +#include <linux/smp.h>
> > +
> > +#include "irq-riscv-aplic-main.h"
> > +
> > +#define APLIC_DISABLE_IDELIVERY		0
> > +#define APLIC_ENABLE_IDELIVERY		1
> > +#define APLIC_DISABLE_ITHRESHOLD	1
> > +#define APLIC_ENABLE_ITHRESHOLD		0
> > +
> > +struct aplic_direct {
> > +	struct aplic_priv	priv;
> > +	struct irq_domain	*irqdomain;
> > +	struct cpumask		lmask;
> > +};
> > +
> > +struct aplic_idc {
> > +	unsigned int		hart_index;
> > +	void __iomem		*regs;
> > +	struct aplic_direct	*direct;
> > +};
> > +
> > +static unsigned int aplic_direct_parent_irq;
> > +static DEFINE_PER_CPU(struct aplic_idc, aplic_idcs);
> > +
> > +static void aplic_direct_irq_eoi(struct irq_data *d)
> > +{
> > +	/*
> > +	 * The fasteoi_handler requires irq_eoi() callback hence
> > +	 * provide a dummy handler.
> > +	 */
> > +}
> > +
> > +#ifdef CONFIG_SMP
> > +static int aplic_direct_set_affinity(struct irq_data *d,
> > +				  const struct cpumask *mask_val, bool force)
> > +{
> > +	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
> > +	struct aplic_direct *direct =
> > +			container_of(priv, struct aplic_direct, priv);
> > +	struct aplic_idc *idc;
> > +	unsigned int cpu, val;
> > +	struct cpumask amask;
> > +	void __iomem *target;
> > +
> > +	cpumask_and(&amask, &direct->lmask, mask_val);
> > +
> > +	if (force)
> > +		cpu = cpumask_first(&amask);
> > +	else
> > +		cpu = cpumask_any_and(&amask, cpu_online_mask);
> > +
> > +	if (cpu >= nr_cpu_ids)
> > +		return -EINVAL;
> > +
> > +	idc = per_cpu_ptr(&aplic_idcs, cpu);
> > +	target = priv->regs + APLIC_TARGET_BASE;
> > +	target += (d->hwirq - 1) * sizeof(u32);
> > +	val = idc->hart_index & APLIC_TARGET_HART_IDX_MASK;
> > +	val <<= APLIC_TARGET_HART_IDX_SHIFT;
> > +	val |= APLIC_DEFAULT_PRIORITY;
> > +	writel(val, target);
> > +
> > +	irq_data_update_effective_affinity(d, cpumask_of(cpu));
> > +
> > +	return IRQ_SET_MASK_OK_DONE;
> > +}
> > +#endif
> > +
> > +static struct irq_chip aplic_direct_chip = {
> > +	.name		= "APLIC-DIRECT",
> > +	.irq_mask	= aplic_irq_mask,
> > +	.irq_unmask	= aplic_irq_unmask,
> > +	.irq_set_type	= aplic_irq_set_type,
> > +	.irq_eoi	= aplic_direct_irq_eoi,
> > +#ifdef CONFIG_SMP
> > +	.irq_set_affinity = aplic_direct_set_affinity,
> > +#endif
> > +	.flags		= IRQCHIP_SET_TYPE_MASKED |
> > +			  IRQCHIP_SKIP_SET_WAKE |
> > +			  IRQCHIP_MASK_ON_SUSPEND,
> > +};
> > +
> > +static int aplic_direct_irqdomain_translate(struct irq_domain *d,
> > +					 struct irq_fwspec *fwspec,
> > +					 unsigned long *hwirq,
> > +					 unsigned int *type)
> > +{
> > +	struct aplic_priv *priv = d->host_data;
> > +
> > +	return aplic_irqdomain_translate(fwspec, priv->gsi_base,
> > +					 hwirq, type);
> > +}
> > +
> > +static int aplic_direct_irqdomain_alloc(struct irq_domain *domain,
> > +				     unsigned int virq, unsigned int nr_irqs,
> > +				     void *arg)
> > +{
> > +	int i, ret;
> > +	unsigned int type;
> > +	irq_hw_number_t hwirq;
> > +	struct irq_fwspec *fwspec = arg;
> > +	struct aplic_priv *priv = domain->host_data;
> > +	struct aplic_direct *direct =
> > +			container_of(priv, struct aplic_direct, priv);
> > +
> > +	ret = aplic_irqdomain_translate(fwspec, priv->gsi_base,
> > +					&hwirq, &type);
> > +	if (ret)
> > +		return ret;
> > +
> > +	for (i = 0; i < nr_irqs; i++) {
> > +		irq_domain_set_info(domain, virq + i, hwirq + i,
> > +				    &aplic_direct_chip, priv,
> > +				    handle_fasteoi_irq, NULL, NULL);
> > +		irq_set_affinity(virq + i, &direct->lmask);
> > +		/* See the reason described in aplic_msi_irqdomain_alloc() */
> > +		irq_set_status_flags(virq + i, IRQ_DISABLE_UNLAZY);
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct irq_domain_ops aplic_direct_irqdomain_ops = {
> > +	.translate	= aplic_direct_irqdomain_translate,
> > +	.alloc		= aplic_direct_irqdomain_alloc,
> > +	.free		= irq_domain_free_irqs_top,
> > +};
> > +
> > +/*
> > + * To handle an APLIC direct interrupts, we just read the CLAIMI register
> > + * which will return highest priority pending interrupt and clear the
> > + * pending bit of the interrupt. This process is repeated until CLAIMI
> > + * register return zero value.
> > + */
> > +static void aplic_direct_handle_irq(struct irq_desc *desc)
> > +{
> > +	struct aplic_idc *idc = this_cpu_ptr(&aplic_idcs);
> > +	struct irq_chip *chip = irq_desc_get_chip(desc);
> > +	struct irq_domain *irqdomain = idc->direct->irqdomain;
> > +	irq_hw_number_t hw_irq;
> > +	int irq;
> > +
> > +	chained_irq_enter(chip, desc);
> > +
> > +	while ((hw_irq = readl(idc->regs + APLIC_IDC_CLAIMI))) {
> > +		hw_irq = hw_irq >> APLIC_IDC_TOPI_ID_SHIFT;
> > +		irq = irq_find_mapping(irqdomain, hw_irq);
> > +
> > +		if (unlikely(irq <= 0))
> > +			dev_warn_ratelimited(idc->direct->priv.dev,
> > +					     "hw_irq %lu mapping not found\n",
> > +					     hw_irq);
> > +		else
> > +			generic_handle_irq(irq);
> > +	}
> > +
> > +	chained_irq_exit(chip, desc);
> > +}
> > +
> > +static void aplic_idc_set_delivery(struct aplic_idc *idc, bool en)
> > +{
> > +	u32 de = (en) ? APLIC_ENABLE_IDELIVERY : APLIC_DISABLE_IDELIVERY;
> > +	u32 th = (en) ? APLIC_ENABLE_ITHRESHOLD : APLIC_DISABLE_ITHRESHOLD;
> > +
> > +	/* Priority must be less than threshold for interrupt triggering */
> > +	writel(th, idc->regs + APLIC_IDC_ITHRESHOLD);
> > +
> > +	/* Delivery must be set to 1 for interrupt triggering */
> > +	writel(de, idc->regs + APLIC_IDC_IDELIVERY);
> > +}
> > +
> > +static int aplic_direct_dying_cpu(unsigned int cpu)
> > +{
> > +	if (aplic_direct_parent_irq)
> > +		disable_percpu_irq(aplic_direct_parent_irq);
> > +
> > +	return 0;
> > +}
> > +
> > +static int aplic_direct_starting_cpu(unsigned int cpu)
> > +{
> > +	if (aplic_direct_parent_irq)
> > +		enable_percpu_irq(aplic_direct_parent_irq,
> > +				irq_get_trigger_type(aplic_direct_parent_irq));
> > +
> > +	return 0;
> > +}
> > +
> > +int aplic_direct_setup(struct device *dev, void __iomem *regs)
> > +{
> > +	int i, j, rc, cpu, setup_count = 0;
> > +	struct fwnode_reference_args parent;
> > +	struct aplic_direct *direct;
> > +	struct aplic_priv *priv;
> > +	struct irq_domain *domain;
> > +	unsigned long hartid;
> > +	struct aplic_idc *idc;
> > +	u32 val;
> > +
> > +	direct = kzalloc(sizeof(*direct), GFP_KERNEL);
> > +	if (!direct)
> > +		return -ENOMEM;
> > +	priv = &direct->priv;
> > +
> > +	rc = aplic_setup_priv(priv, dev, regs);
> > +	if (rc) {
> > +		dev_err(dev, "failed to create APLIC context\n");
> > +		kfree(direct);
> > +		return rc;
> > +	}
> > +
> > +	/* Setup per-CPU IDC and target CPU mask */
> > +	for (i = 0; i < priv->nr_idcs; i++) {
> > +		rc = fwnode_property_get_reference_args(dev->fwnode,
> > +				"interrupts-extended", "#interrupt-cells",
> > +				0, i, &parent);
> > +		if (rc) {
> > +			dev_warn(dev, "parent irq for IDC%d not found\n", i);
> > +			continue;
> > +		}
> > +
> > +		/*
> > +		 * Skip interrupts other than external interrupts for
> > +		 * current privilege level.
> > +		 */
> > +		if (parent.args[0] != RV_IRQ_EXT)
> > +			continue;
> > +
> > +		rc = riscv_get_intc_hartid(parent.fwnode, &hartid);
> > +		if (rc) {
> > +			dev_warn(dev, "invalid hartid for IDC%d\n", i);
> > +			continue;
> > +		}
> > +
> > +		cpu = riscv_hartid_to_cpuid(hartid);
> > +		if (cpu < 0) {
> > +			dev_warn(dev, "invalid cpuid for IDC%d\n", i);
> > +			continue;
> > +		}
> > +
> > +		cpumask_set_cpu(cpu, &direct->lmask);
> > +
> > +		idc = per_cpu_ptr(&aplic_idcs, cpu);
> > +		idc->hart_index = i;
> > +		idc->regs = priv->regs + APLIC_IDC_BASE + i * APLIC_IDC_SIZE;
> > +		idc->direct = direct;
> > +
> > +		aplic_idc_set_delivery(idc, true);
> > +
> > +		/*
> > +		 * Boot cpu might not have APLIC hart_index = 0 so check
> > +		 * and update target registers of all interrupts.
> > +		 */
> > +		if (cpu == smp_processor_id() && idc->hart_index) {
> > +			val = idc->hart_index & APLIC_TARGET_HART_IDX_MASK;
> > +			val <<= APLIC_TARGET_HART_IDX_SHIFT;
> > +			val |= APLIC_DEFAULT_PRIORITY;
> > +			for (j = 1; j <= priv->nr_irqs; j++)
> > +				writel(val, priv->regs + APLIC_TARGET_BASE +
> > +					    (j - 1) * sizeof(u32));
> > +		}
> > +
> > +		setup_count++;
> > +	}
> > +
> > +	/* Find parent domain and register chained handler */
> > +	domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
> > +					  DOMAIN_BUS_ANY);
> > +	if (!aplic_direct_parent_irq && domain) {
> > +		aplic_direct_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT);
> > +		if (aplic_direct_parent_irq) {
> > +			irq_set_chained_handler(aplic_direct_parent_irq,
> > +						aplic_direct_handle_irq);
> > +
> > +			/*
> > +			 * Setup CPUHP notifier to enable parent
> > +			 * interrupt on all CPUs
> > +			 */
> > +			cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
> > +					  "irqchip/riscv/aplic:starting",
> > +					  aplic_direct_starting_cpu,
> > +					  aplic_direct_dying_cpu);
> > +		}
> > +	}
> > +
> > +	/* Fail if we were not able to setup IDC for any CPU */
> > +	if (!setup_count) {
> > +		kfree(direct);
> > +		return -ENODEV;
> > +	}
> > +
> > +	/* Setup global config and interrupt delivery */
> > +	aplic_init_hw_global(priv, false);
> > +
> > +	/* Create irq domain instance for the APLIC */
> > +	direct->irqdomain = irq_domain_create_linear(dev->fwnode,
> > +						   priv->nr_irqs + 1,
> > +						   &aplic_direct_irqdomain_ops,
> > +						   priv);
> > +	if (!direct->irqdomain) {
> > +		dev_err(dev, "failed to create direct irq domain\n");
> > +		kfree(direct);
> > +		return -ENOMEM;
> > +	}
> > +
> > +	/* Advertise the interrupt controller */
> > +	dev_info(dev, "%d interrupts directly connected to %d CPUs\n",
> > +		 priv->nr_irqs, priv->nr_idcs);
> > +
> > +	return 0;
> > +}
> > diff --git a/drivers/irqchip/irq-riscv-aplic-main.c b/drivers/irqchip/irq-riscv-aplic-main.c
> > new file mode 100644
> > index 000000000000..d62a096774c4
> > --- /dev/null
> > +++ b/drivers/irqchip/irq-riscv-aplic-main.c
> > @@ -0,0 +1,240 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +
> > +#include <linux/printk.h>
> > +#include <linux/module.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/irqchip/riscv-aplic.h>
> > +
> > +#include "irq-riscv-aplic-main.h"
> > +
> > +void aplic_irq_unmask(struct irq_data *d)
> > +{
> > +	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
> > +
> > +	writel(d->hwirq, priv->regs + APLIC_SETIENUM);
> > +}
> > +
> > +void aplic_irq_mask(struct irq_data *d)
> > +{
> > +	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
> > +
> > +	writel(d->hwirq, priv->regs + APLIC_CLRIENUM);
> > +}
> > +
> > +int aplic_irq_set_type(struct irq_data *d, unsigned int type)
> > +{
> > +	u32 val = 0;
> > +	void __iomem *sourcecfg;
> > +	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
> > +
> > +	switch (type) {
> > +	case IRQ_TYPE_NONE:
> > +		val = APLIC_SOURCECFG_SM_INACTIVE;
> > +		break;
> > +	case IRQ_TYPE_LEVEL_LOW:
> > +		val = APLIC_SOURCECFG_SM_LEVEL_LOW;
> > +		break;
> > +	case IRQ_TYPE_LEVEL_HIGH:
> > +		val = APLIC_SOURCECFG_SM_LEVEL_HIGH;
> > +		break;
> > +	case IRQ_TYPE_EDGE_FALLING:
> > +		val = APLIC_SOURCECFG_SM_EDGE_FALL;
> > +		break;
> > +	case IRQ_TYPE_EDGE_RISING:
> > +		val = APLIC_SOURCECFG_SM_EDGE_RISE;
> > +		break;
> > +	default:
> > +		return -EINVAL;
> > +	}
> > +
> > +	sourcecfg = priv->regs + APLIC_SOURCECFG_BASE;
> > +	sourcecfg += (d->hwirq - 1) * sizeof(u32);
> > +	writel(val, sourcecfg);
> > +
> > +	return 0;
> > +}
> > +
> > +int aplic_irqdomain_translate(struct irq_fwspec *fwspec, u32 gsi_base,
> > +			      unsigned long *hwirq, unsigned int *type)
> > +{
> > +	if (WARN_ON(fwspec->param_count < 2))
> > +		return -EINVAL;
> > +	if (WARN_ON(!fwspec->param[0]))
> > +		return -EINVAL;
> > +
> > +	/* For DT, gsi_base is always zero. */
> > +	*hwirq = fwspec->param[0] - gsi_base;
> > +	*type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
> > +
> > +	WARN_ON(*type == IRQ_TYPE_NONE);
> > +
> > +	return 0;
> > +}
> > +
> > +void aplic_init_hw_global(struct aplic_priv *priv, bool msi_mode)
> > +{
> > +	u32 val;
> > +#ifdef CONFIG_RISCV_M_MODE
> > +	u32 valH;
> > +
> > +	if (msi_mode) {
> > +		val = priv->msicfg.base_ppn;
> > +		valH = ((u64)priv->msicfg.base_ppn >> 32) &
> > +			APLIC_xMSICFGADDRH_BAPPN_MASK;
> > +		valH |= (priv->msicfg.lhxw & APLIC_xMSICFGADDRH_LHXW_MASK)
> > +			<< APLIC_xMSICFGADDRH_LHXW_SHIFT;
> > +		valH |= (priv->msicfg.hhxw & APLIC_xMSICFGADDRH_HHXW_MASK)
> > +			<< APLIC_xMSICFGADDRH_HHXW_SHIFT;
> > +		valH |= (priv->msicfg.lhxs & APLIC_xMSICFGADDRH_LHXS_MASK)
> > +			<< APLIC_xMSICFGADDRH_LHXS_SHIFT;
> > +		valH |= (priv->msicfg.hhxs & APLIC_xMSICFGADDRH_HHXS_MASK)
> > +			<< APLIC_xMSICFGADDRH_HHXS_SHIFT;
> > +		writel(val, priv->regs + APLIC_xMSICFGADDR);
> > +		writel(valH, priv->regs + APLIC_xMSICFGADDRH);
> > +	}
> > +#endif
> > +
> > +	/* Setup APLIC domaincfg register */
> > +	val = readl(priv->regs + APLIC_DOMAINCFG);
> > +	val |= APLIC_DOMAINCFG_IE;
> > +	if (msi_mode)
> > +		val |= APLIC_DOMAINCFG_DM;
> > +	writel(val, priv->regs + APLIC_DOMAINCFG);
> > +	if (readl(priv->regs + APLIC_DOMAINCFG) != val)
> > +		dev_warn(priv->dev, "unable to write 0x%x in domaincfg\n",
> > +			 val);
> > +}
> > +
> > +static void aplic_init_hw_irqs(struct aplic_priv *priv)
> > +{
> > +	int i;
> > +
> > +	/* Disable all interrupts */
> > +	for (i = 0; i <= priv->nr_irqs; i += 32)
> > +		writel(-1U, priv->regs + APLIC_CLRIE_BASE +
> > +			    (i / 32) * sizeof(u32));
> > +
> > +	/* Set interrupt type and default priority for all interrupts */
> > +	for (i = 1; i <= priv->nr_irqs; i++) {
> > +		writel(0, priv->regs + APLIC_SOURCECFG_BASE +
> > +			  (i - 1) * sizeof(u32));
> > +		writel(APLIC_DEFAULT_PRIORITY,
> > +		       priv->regs + APLIC_TARGET_BASE +
> > +		       (i - 1) * sizeof(u32));
> > +	}
> > +
> > +	/* Clear APLIC domaincfg */
> > +	writel(0, priv->regs + APLIC_DOMAINCFG);
> > +}
> > +
> > +int aplic_setup_priv(struct aplic_priv *priv, struct device *dev,
> > +		     void __iomem *regs)
> > +{
> > +	struct fwnode_reference_args parent;
> > +	int rc;
> > +
> > +	/* Save device pointer and register base */
> > +	priv->dev = dev;
> > +	priv->regs = regs;
> > +
> > +	/*
> > +	 * Find out GSI base number
> > +	 *
> > +	 * Note: DT does not define "riscv,gsi-base" property so GSI
> > +	 * base is always zero for DT.
> > +	 */
> > +	rc = fwnode_property_read_u32_array(dev->fwnode, "riscv,gsi-base",
> > +					    &priv->gsi_base, 1);
> For DT, you can just initialize this to 0 without reading the property.
> 
> > +	if (rc)
> > +		priv->gsi_base = 0;
> > +
> > +	/* Find out number of interrupt sources */
> > +	rc = fwnode_property_read_u32_array(dev->fwnode, "riscv,num-sources",
> > +					    &priv->nr_irqs, 1);
> > +	if (rc) {
> > +		dev_err(dev, "failed to get number of interrupt sources\n");
> > +		return rc;
> > +	}
> > +
> > +	/* Setup initial state APLIC interrupts */
> > +	aplic_init_hw_irqs(priv);
> > +
> > +	/*
> > +	 * Find out number of IDCs based on parent interrupts
> > +	 *
> > +	 * If "msi-parent" property is present then we ignore the
> > +	 * APLIC IDCs which forces the APLIC driver to use MSI mode.
> > +	 */
> > +	if (!fwnode_property_present(dev->fwnode, "msi-parent")) {
> > +		while (!fwnode_property_get_reference_args(dev->fwnode,
> > +				"interrupts-extended", "#interrupt-cells",
> > +				0, priv->nr_idcs, &parent))
> > +			priv->nr_idcs++;
> > +	}
> > +
> Can this finding nr_idcs be done after aplic_init_hw_irqs() above?
> 
Sorry, I meant prior to calling aplic_init_hw_irqs().

Thanks,
Sunl

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Re: [PATCH v8 10/16] irqchip/riscv-imsic: Add support for platform MSI irqdomain

[Ruan Jinjie]

On 2023/9/13 1:49, Anup Patel wrote:
> The Linux platform MSI support requires a platform MSI irqdomain so
> let us add a platform irqchip driver for RISC-V IMSIC which provides
> a base IRQ domain and platform MSI domain. This driver assumes that
> the IMSIC state is already initialized by the IMSIC early driver.
> 
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> ---
>  drivers/irqchip/Makefile                   |   2 +-
>  drivers/irqchip/irq-riscv-imsic-platform.c | 280 +++++++++++++++++++++
>  2 files changed, 281 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/irqchip/irq-riscv-imsic-platform.c
> 
> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index d714724387ce..abca445a3229 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -95,7 +95,7 @@ obj-$(CONFIG_QCOM_MPM)			+= irq-qcom-mpm.o
>  obj-$(CONFIG_CSKY_MPINTC)		+= irq-csky-mpintc.o
>  obj-$(CONFIG_CSKY_APB_INTC)		+= irq-csky-apb-intc.o
>  obj-$(CONFIG_RISCV_INTC)		+= irq-riscv-intc.o
> -obj-$(CONFIG_RISCV_IMSIC)		+= irq-riscv-imsic-state.o irq-riscv-imsic-early.o
> +obj-$(CONFIG_RISCV_IMSIC)		+= irq-riscv-imsic-state.o irq-riscv-imsic-early.o irq-riscv-imsic-platform.o
>  obj-$(CONFIG_SIFIVE_PLIC)		+= irq-sifive-plic.o
>  obj-$(CONFIG_IMX_IRQSTEER)		+= irq-imx-irqsteer.o
>  obj-$(CONFIG_IMX_INTMUX)		+= irq-imx-intmux.o
> diff --git a/drivers/irqchip/irq-riscv-imsic-platform.c b/drivers/irqchip/irq-riscv-imsic-platform.c
> new file mode 100644
> index 000000000000..b78f1b2ee3dc
> --- /dev/null
> +++ b/drivers/irqchip/irq-riscv-imsic-platform.c
> @@ -0,0 +1,280 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> + * Copyright (C) 2022 Ventana Micro Systems Inc.
> + */
> +
> +#include <linux/bitmap.h>
> +#include <linux/cpu.h>
> +#include <linux/interrupt.h>
> +#include <linux/irq.h>
> +#include <linux/irqchip.h>
> +#include <linux/irqdomain.h>
> +#include <linux/module.h>
> +#include <linux/msi.h>
> +#include <linux/platform_device.h>
> +#include <linux/spinlock.h>
> +#include <linux/smp.h>
> +
> +#include "irq-riscv-imsic-state.h"
> +
> +static int imsic_cpu_page_phys(unsigned int cpu,
> +			       unsigned int guest_index,
> +			       phys_addr_t *out_msi_pa)
> +{
> +	struct imsic_global_config *global;
> +	struct imsic_local_config *local;
> +
> +	global = &imsic->global;
> +	local = per_cpu_ptr(global->local, cpu);
> +
> +	if (BIT(global->guest_index_bits) <= guest_index)
> +		return -EINVAL;
> +
> +	if (out_msi_pa)
> +		*out_msi_pa = local->msi_pa +
> +			      (guest_index * IMSIC_MMIO_PAGE_SZ);
> +
> +	return 0;
> +}
> +
> +static int imsic_get_cpu(const struct cpumask *mask_val, bool force,
> +			 unsigned int *out_target_cpu)
> +{
> +	unsigned int cpu;
> +
> +	if (force)
> +		cpu = cpumask_first(mask_val);
> +	else
> +		cpu = cpumask_any_and(mask_val, cpu_online_mask);
> +
> +	if (cpu >= nr_cpu_ids)
> +		return -EINVAL;
> +
> +	if (out_target_cpu)
> +		*out_target_cpu = cpu;
> +
> +	return 0;
> +}
> +
> +static void imsic_irq_mask(struct irq_data *d)
> +{
> +	unsigned long flags;
> +
> +	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> +	bitmap_clear(imsic->ids_enabled_bimap, d->hwirq, 1);
> +	__imsic_id_disable(d->hwirq);
> +	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> +
> +	imsic_ids_remote_sync();
> +}
> +
> +static void imsic_irq_unmask(struct irq_data *d)
> +{
> +	unsigned long flags;
> +
> +	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> +	bitmap_set(imsic->ids_enabled_bimap, d->hwirq, 1);
> +	__imsic_id_enable(d->hwirq);
> +	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> +
> +	imsic_ids_remote_sync();
> +}
> +
> +static void imsic_irq_compose_msi_msg(struct irq_data *d,
> +				      struct msi_msg *msg)
> +{
> +	phys_addr_t msi_addr;
> +	unsigned int cpu;
> +	int err;
> +
> +	cpu = imsic_id_get_target(d->hwirq);
> +	if (WARN_ON(cpu == UINT_MAX))
> +		return;
> +
> +	err = imsic_cpu_page_phys(cpu, 0, &msi_addr);
> +	if (WARN_ON(err))
> +		return;
> +
> +	msg->address_hi = upper_32_bits(msi_addr);
> +	msg->address_lo = lower_32_bits(msi_addr);
> +	msg->data = d->hwirq;
> +}
> +
> +#ifdef CONFIG_SMP
> +static int imsic_irq_set_affinity(struct irq_data *d,
> +				  const struct cpumask *mask_val,
> +				  bool force)
> +{
> +	unsigned int target_cpu;
> +	int rc;
> +
> +	rc = imsic_get_cpu(mask_val, force, &target_cpu);
> +	if (rc)
> +		return rc;
> +
> +	imsic_id_set_target(d->hwirq, target_cpu);
> +	irq_data_update_effective_affinity(d, cpumask_of(target_cpu));

According to the “The RISC-V Advanced Interrupt Architecture Version
0.2-draft”，the "3.1 Interrupt files and interrupt identities" has
following description.

Thus the total number of MSI sources that can be separately distinguished
within a system is potentially the product of the number of interrupt
identities at a single interrupt
file times the total number of interrupt files in the system, over all
harts.

In my opinion, the MSI interrupt number is a local interrupt number.
However, when the above interrupt affinity is set, it is processed as a
global interrupt number, which seems not comply with the above RISC-V
specifications.

> +
> +	return IRQ_SET_MASK_OK;
> +}
> +#endif
> +
> +static struct irq_chip imsic_irq_base_chip = {
> +	.name			= "IMSIC-BASE",
> +	.irq_mask		= imsic_irq_mask,
> +	.irq_unmask		= imsic_irq_unmask,
> +#ifdef CONFIG_SMP
> +	.irq_set_affinity	= imsic_irq_set_affinity,
> +#endif
> +	.irq_compose_msi_msg	= imsic_irq_compose_msi_msg,
> +	.flags			= IRQCHIP_SKIP_SET_WAKE |
> +				  IRQCHIP_MASK_ON_SUSPEND,
> +};
> +
> +static int imsic_irq_domain_alloc(struct irq_domain *domain,
> +				  unsigned int virq,
> +				  unsigned int nr_irqs,
> +				  void *args)
> +{
> +	int i, hwirq, err = 0;
> +	unsigned int cpu;
> +
> +	err = imsic_get_cpu(cpu_online_mask, false, &cpu);
> +	if (err)
> +		return err;
> +
> +	hwirq = imsic_ids_alloc(get_count_order(nr_irqs));
> +	if (hwirq < 0)
> +		return hwirq;
> +
> +	for (i = 0; i < nr_irqs; i++) {
> +		imsic_id_set_target(hwirq + i, cpu);
> +		irq_domain_set_info(domain, virq + i, hwirq + i,
> +				    &imsic_irq_base_chip, imsic,
> +				    handle_simple_irq, NULL, NULL);
> +		irq_set_noprobe(virq + i);
> +		irq_set_affinity(virq + i, cpu_online_mask);
> +		/*
> +		 * IMSIC does not implement irq_disable() so Linux interrupt
> +		 * subsystem will take a lazy approach for disabling an IMSIC
> +		 * interrupt. This means IMSIC interrupts are left unmasked
> +		 * upon system suspend and interrupts are not processed
> +		 * immediately upon system wake up. To tackle this, we disable
> +		 * the lazy approach for all IMSIC interrupts.
> +		 */
> +		irq_set_status_flags(virq + i, IRQ_DISABLE_UNLAZY);
> +	}
> +
> +	return 0;
> +}
> +
> +static void imsic_irq_domain_free(struct irq_domain *domain,
> +				  unsigned int virq,
> +				  unsigned int nr_irqs)
> +{
> +	struct irq_data *d = irq_domain_get_irq_data(domain, virq);
> +
> +	imsic_ids_free(d->hwirq, get_count_order(nr_irqs));
> +	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
> +}
> +
> +static const struct irq_domain_ops imsic_base_domain_ops = {
> +	.alloc		= imsic_irq_domain_alloc,
> +	.free		= imsic_irq_domain_free,
> +};
> +
> +static struct irq_chip imsic_plat_irq_chip = {
> +	.name			= "IMSIC-PLAT",
> +};
> +
> +static struct msi_domain_ops imsic_plat_domain_ops = {
> +};
> +
> +static struct msi_domain_info imsic_plat_domain_info = {
> +	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
> +	.ops	= &imsic_plat_domain_ops,
> +	.chip	= &imsic_plat_irq_chip,
> +};
> +
> +static int imsic_irq_domains_init(struct device *dev)
> +{
> +	/* Create Base IRQ domain */
> +	imsic->base_domain = irq_domain_create_tree(dev->fwnode,
> +					&imsic_base_domain_ops, imsic);
> +	if (!imsic->base_domain) {
> +		dev_err(dev, "failed to create IMSIC base domain\n");
> +		return -ENOMEM;
> +	}
> +	irq_domain_update_bus_token(imsic->base_domain, DOMAIN_BUS_NEXUS);
> +
> +	/* Create Platform MSI domain */
> +	imsic->plat_domain = platform_msi_create_irq_domain(dev->fwnode,
> +						&imsic_plat_domain_info,
> +						imsic->base_domain);
> +	if (!imsic->plat_domain) {
> +		dev_err(dev, "failed to create IMSIC platform domain\n");
> +		irq_domain_remove(imsic->base_domain);
> +		return -ENOMEM;
> +	}
> +
> +	return 0;
> +}
> +
> +static int imsic_platform_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct imsic_global_config *global;
> +	int rc;
> +
> +	if (!imsic) {
> +		dev_err(dev, "early driver not probed\n");
> +		return -ENODEV;
> +	}
> +
> +	if (imsic->base_domain) {
> +		dev_err(dev, "irq domain already created\n");
> +		return -ENODEV;
> +	}
> +
> +	global = &imsic->global;
> +
> +	/* Initialize IRQ and MSI domains */
> +	rc = imsic_irq_domains_init(dev);
> +	if (rc) {
> +		dev_err(dev, "failed to initialize IRQ and MSI domains\n");
> +		return rc;
> +	}
> +
> +	dev_info(dev, "  hart-index-bits: %d,  guest-index-bits: %d\n",
> +		 global->hart_index_bits, global->guest_index_bits);
> +	dev_info(dev, " group-index-bits: %d, group-index-shift: %d\n",
> +		 global->group_index_bits, global->group_index_shift);
> +	dev_info(dev, " mapped %d interrupts at base PPN %pa\n",
> +		 global->nr_ids, &global->base_addr);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id imsic_platform_match[] = {
> +	{ .compatible = "riscv,imsics" },
> +	{}
> +};
> +
> +static struct platform_driver imsic_platform_driver = {
> +	.driver = {
> +		.name		= "riscv-imsic",
> +		.of_match_table	= imsic_platform_match,
> +	},
> +	.probe = imsic_platform_probe,
> +};
> +
> +static int __init imsic_platform_init(void)
> +{
> +	/*
> +	 * Register IMSIC driver as early as possible so that IMSIC
> +	 * platform device is probed as soon as it is created.
> +	 */
> +	return platform_driver_register(&imsic_platform_driver);
> +}
> +core_initcall(imsic_platform_init);

Re: [PATCH v8 10/16] irqchip/riscv-imsic: Add support for platform MSI irqdomain

[Ruan Jinjie]

On 2023/9/13 1:49, Anup Patel wrote:
> The Linux platform MSI support requires a platform MSI irqdomain so
> let us add a platform irqchip driver for RISC-V IMSIC which provides
> a base IRQ domain and platform MSI domain. This driver assumes that
> the IMSIC state is already initialized by the IMSIC early driver.
> 
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> ---
>  drivers/irqchip/Makefile                   |   2 +-
>  drivers/irqchip/irq-riscv-imsic-platform.c | 280 +++++++++++++++++++++
>  2 files changed, 281 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/irqchip/irq-riscv-imsic-platform.c
> 
> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index d714724387ce..abca445a3229 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -95,7 +95,7 @@ obj-$(CONFIG_QCOM_MPM)			+= irq-qcom-mpm.o
>  obj-$(CONFIG_CSKY_MPINTC)		+= irq-csky-mpintc.o
>  obj-$(CONFIG_CSKY_APB_INTC)		+= irq-csky-apb-intc.o
>  obj-$(CONFIG_RISCV_INTC)		+= irq-riscv-intc.o
> -obj-$(CONFIG_RISCV_IMSIC)		+= irq-riscv-imsic-state.o irq-riscv-imsic-early.o
> +obj-$(CONFIG_RISCV_IMSIC)		+= irq-riscv-imsic-state.o irq-riscv-imsic-early.o irq-riscv-imsic-platform.o
>  obj-$(CONFIG_SIFIVE_PLIC)		+= irq-sifive-plic.o
>  obj-$(CONFIG_IMX_IRQSTEER)		+= irq-imx-irqsteer.o
>  obj-$(CONFIG_IMX_INTMUX)		+= irq-imx-intmux.o
> diff --git a/drivers/irqchip/irq-riscv-imsic-platform.c b/drivers/irqchip/irq-riscv-imsic-platform.c
> new file mode 100644
> index 000000000000..b78f1b2ee3dc
> --- /dev/null
> +++ b/drivers/irqchip/irq-riscv-imsic-platform.c
> @@ -0,0 +1,280 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> + * Copyright (C) 2022 Ventana Micro Systems Inc.
> + */
> +
> +#include <linux/bitmap.h>
> +#include <linux/cpu.h>
> +#include <linux/interrupt.h>
> +#include <linux/irq.h>
> +#include <linux/irqchip.h>
> +#include <linux/irqdomain.h>
> +#include <linux/module.h>
> +#include <linux/msi.h>
> +#include <linux/platform_device.h>
> +#include <linux/spinlock.h>
> +#include <linux/smp.h>
> +
> +#include "irq-riscv-imsic-state.h"
> +
> +static int imsic_cpu_page_phys(unsigned int cpu,
> +			       unsigned int guest_index,
> +			       phys_addr_t *out_msi_pa)
> +{
> +	struct imsic_global_config *global;
> +	struct imsic_local_config *local;
> +
> +	global = &imsic->global;
> +	local = per_cpu_ptr(global->local, cpu);
> +
> +	if (BIT(global->guest_index_bits) <= guest_index)
> +		return -EINVAL;
> +
> +	if (out_msi_pa)
> +		*out_msi_pa = local->msi_pa +
> +			      (guest_index * IMSIC_MMIO_PAGE_SZ);
> +
> +	return 0;
> +}
> +
> +static int imsic_get_cpu(const struct cpumask *mask_val, bool force,
> +			 unsigned int *out_target_cpu)
> +{
> +	unsigned int cpu;
> +
> +	if (force)
> +		cpu = cpumask_first(mask_val);
> +	else
> +		cpu = cpumask_any_and(mask_val, cpu_online_mask);
> +
> +	if (cpu >= nr_cpu_ids)
> +		return -EINVAL;
> +
> +	if (out_target_cpu)
> +		*out_target_cpu = cpu;
> +
> +	return 0;
> +}
> +
> +static void imsic_irq_mask(struct irq_data *d)
> +{
> +	unsigned long flags;
> +
> +	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> +	bitmap_clear(imsic->ids_enabled_bimap, d->hwirq, 1);
> +	__imsic_id_disable(d->hwirq);
> +	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> +
> +	imsic_ids_remote_sync();
> +}
> +
> +static void imsic_irq_unmask(struct irq_data *d)
> +{
> +	unsigned long flags;
> +
> +	raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> +	bitmap_set(imsic->ids_enabled_bimap, d->hwirq, 1);
> +	__imsic_id_enable(d->hwirq);
> +	raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> +
> +	imsic_ids_remote_sync();
> +}
> +
> +static void imsic_irq_compose_msi_msg(struct irq_data *d,
> +				      struct msi_msg *msg)
> +{
> +	phys_addr_t msi_addr;
> +	unsigned int cpu;
> +	int err;
> +
> +	cpu = imsic_id_get_target(d->hwirq);
> +	if (WARN_ON(cpu == UINT_MAX))
> +		return;
> +
> +	err = imsic_cpu_page_phys(cpu, 0, &msi_addr);
> +	if (WARN_ON(err))
> +		return;
> +
> +	msg->address_hi = upper_32_bits(msi_addr);
> +	msg->address_lo = lower_32_bits(msi_addr);
> +	msg->data = d->hwirq;
> +}
> +
> +#ifdef CONFIG_SMP
> +static int imsic_irq_set_affinity(struct irq_data *d,
> +				  const struct cpumask *mask_val,
> +				  bool force)
> +{
> +	unsigned int target_cpu;
> +	int rc;
> +
> +	rc = imsic_get_cpu(mask_val, force, &target_cpu);
> +	if (rc)
> +		return rc;
> +
> +	imsic_id_set_target(d->hwirq, target_cpu);
> +	irq_data_update_effective_affinity(d, cpumask_of(target_cpu));

According to the “The RISC-V Advanced Interrupt Architecture Version
0.2-draft”，the "3.1 Interrupt files and interrupt identities" has
following description.

Thus the total number of MSI sources that can be separately distinguished
within a system is potentially the product of the number of interrupt
identities at a single interrupt
file times the total number of interrupt files in the system, over all
harts.

In my opinion, the MSI interrupt number is a local interrupt number.
However, when the above interrupt affinity is set, it is processed as a
global interrupt number, which seems not comply with the above RISC-V
specifications.

> +
> +	return IRQ_SET_MASK_OK;
> +}
> +#endif
> +
> +static struct irq_chip imsic_irq_base_chip = {
> +	.name			= "IMSIC-BASE",
> +	.irq_mask		= imsic_irq_mask,
> +	.irq_unmask		= imsic_irq_unmask,
> +#ifdef CONFIG_SMP
> +	.irq_set_affinity	= imsic_irq_set_affinity,
> +#endif
> +	.irq_compose_msi_msg	= imsic_irq_compose_msi_msg,
> +	.flags			= IRQCHIP_SKIP_SET_WAKE |
> +				  IRQCHIP_MASK_ON_SUSPEND,
> +};
> +
> +static int imsic_irq_domain_alloc(struct irq_domain *domain,
> +				  unsigned int virq,
> +				  unsigned int nr_irqs,
> +				  void *args)
> +{
> +	int i, hwirq, err = 0;
> +	unsigned int cpu;
> +
> +	err = imsic_get_cpu(cpu_online_mask, false, &cpu);
> +	if (err)
> +		return err;
> +
> +	hwirq = imsic_ids_alloc(get_count_order(nr_irqs));
> +	if (hwirq < 0)
> +		return hwirq;
> +
> +	for (i = 0; i < nr_irqs; i++) {
> +		imsic_id_set_target(hwirq + i, cpu);
> +		irq_domain_set_info(domain, virq + i, hwirq + i,
> +				    &imsic_irq_base_chip, imsic,
> +				    handle_simple_irq, NULL, NULL);
> +		irq_set_noprobe(virq + i);
> +		irq_set_affinity(virq + i, cpu_online_mask);
> +		/*
> +		 * IMSIC does not implement irq_disable() so Linux interrupt
> +		 * subsystem will take a lazy approach for disabling an IMSIC
> +		 * interrupt. This means IMSIC interrupts are left unmasked
> +		 * upon system suspend and interrupts are not processed
> +		 * immediately upon system wake up. To tackle this, we disable
> +		 * the lazy approach for all IMSIC interrupts.
> +		 */
> +		irq_set_status_flags(virq + i, IRQ_DISABLE_UNLAZY);
> +	}
> +
> +	return 0;
> +}
> +
> +static void imsic_irq_domain_free(struct irq_domain *domain,
> +				  unsigned int virq,
> +				  unsigned int nr_irqs)
> +{
> +	struct irq_data *d = irq_domain_get_irq_data(domain, virq);
> +
> +	imsic_ids_free(d->hwirq, get_count_order(nr_irqs));
> +	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
> +}
> +
> +static const struct irq_domain_ops imsic_base_domain_ops = {
> +	.alloc		= imsic_irq_domain_alloc,
> +	.free		= imsic_irq_domain_free,
> +};
> +
> +static struct irq_chip imsic_plat_irq_chip = {
> +	.name			= "IMSIC-PLAT",
> +};
> +
> +static struct msi_domain_ops imsic_plat_domain_ops = {
> +};
> +
> +static struct msi_domain_info imsic_plat_domain_info = {
> +	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
> +	.ops	= &imsic_plat_domain_ops,
> +	.chip	= &imsic_plat_irq_chip,
> +};
> +
> +static int imsic_irq_domains_init(struct device *dev)
> +{
> +	/* Create Base IRQ domain */
> +	imsic->base_domain = irq_domain_create_tree(dev->fwnode,
> +					&imsic_base_domain_ops, imsic);
> +	if (!imsic->base_domain) {
> +		dev_err(dev, "failed to create IMSIC base domain\n");
> +		return -ENOMEM;
> +	}
> +	irq_domain_update_bus_token(imsic->base_domain, DOMAIN_BUS_NEXUS);
> +
> +	/* Create Platform MSI domain */
> +	imsic->plat_domain = platform_msi_create_irq_domain(dev->fwnode,
> +						&imsic_plat_domain_info,
> +						imsic->base_domain);
> +	if (!imsic->plat_domain) {
> +		dev_err(dev, "failed to create IMSIC platform domain\n");
> +		irq_domain_remove(imsic->base_domain);
> +		return -ENOMEM;
> +	}
> +
> +	return 0;
> +}
> +
> +static int imsic_platform_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct imsic_global_config *global;
> +	int rc;
> +
> +	if (!imsic) {
> +		dev_err(dev, "early driver not probed\n");
> +		return -ENODEV;
> +	}
> +
> +	if (imsic->base_domain) {
> +		dev_err(dev, "irq domain already created\n");
> +		return -ENODEV;
> +	}
> +
> +	global = &imsic->global;
> +
> +	/* Initialize IRQ and MSI domains */
> +	rc = imsic_irq_domains_init(dev);
> +	if (rc) {
> +		dev_err(dev, "failed to initialize IRQ and MSI domains\n");
> +		return rc;
> +	}
> +
> +	dev_info(dev, "  hart-index-bits: %d,  guest-index-bits: %d\n",
> +		 global->hart_index_bits, global->guest_index_bits);
> +	dev_info(dev, " group-index-bits: %d, group-index-shift: %d\n",
> +		 global->group_index_bits, global->group_index_shift);
> +	dev_info(dev, " mapped %d interrupts at base PPN %pa\n",
> +		 global->nr_ids, &global->base_addr);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id imsic_platform_match[] = {
> +	{ .compatible = "riscv,imsics" },
> +	{}
> +};
> +
> +static struct platform_driver imsic_platform_driver = {
> +	.driver = {
> +		.name		= "riscv-imsic",
> +		.of_match_table	= imsic_platform_match,
> +	},
> +	.probe = imsic_platform_probe,
> +};
> +
> +static int __init imsic_platform_init(void)
> +{
> +	/*
> +	 * Register IMSIC driver as early as possible so that IMSIC
> +	 * platform device is probed as soon as it is created.
> +	 */
> +	return platform_driver_register(&imsic_platform_driver);
> +}
> +core_initcall(imsic_platform_init);

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Re: [PATCH v8 10/16] irqchip/riscv-imsic: Add support for platform MSI irqdomain

[Anup Patel]

On Mon, Sep 25, 2023 at 6:31 PM Ruan Jinjie <ruanjinjie@huawei.com> wrote:
>
>
>
> On 2023/9/13 1:49, Anup Patel wrote:
> > The Linux platform MSI support requires a platform MSI irqdomain so
> > let us add a platform irqchip driver for RISC-V IMSIC which provides
> > a base IRQ domain and platform MSI domain. This driver assumes that
> > the IMSIC state is already initialized by the IMSIC early driver.
> >
> > Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> > ---
> >  drivers/irqchip/Makefile                   |   2 +-
> >  drivers/irqchip/irq-riscv-imsic-platform.c | 280 +++++++++++++++++++++
> >  2 files changed, 281 insertions(+), 1 deletion(-)
> >  create mode 100644 drivers/irqchip/irq-riscv-imsic-platform.c
> >
> > diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> > index d714724387ce..abca445a3229 100644
> > --- a/drivers/irqchip/Makefile
> > +++ b/drivers/irqchip/Makefile
> > @@ -95,7 +95,7 @@ obj-$(CONFIG_QCOM_MPM)                      += irq-qcom-mpm.o
> >  obj-$(CONFIG_CSKY_MPINTC)            += irq-csky-mpintc.o
> >  obj-$(CONFIG_CSKY_APB_INTC)          += irq-csky-apb-intc.o
> >  obj-$(CONFIG_RISCV_INTC)             += irq-riscv-intc.o
> > -obj-$(CONFIG_RISCV_IMSIC)            += irq-riscv-imsic-state.o irq-riscv-imsic-early.o
> > +obj-$(CONFIG_RISCV_IMSIC)            += irq-riscv-imsic-state.o irq-riscv-imsic-early.o irq-riscv-imsic-platform.o
> >  obj-$(CONFIG_SIFIVE_PLIC)            += irq-sifive-plic.o
> >  obj-$(CONFIG_IMX_IRQSTEER)           += irq-imx-irqsteer.o
> >  obj-$(CONFIG_IMX_INTMUX)             += irq-imx-intmux.o
> > diff --git a/drivers/irqchip/irq-riscv-imsic-platform.c b/drivers/irqchip/irq-riscv-imsic-platform.c
> > new file mode 100644
> > index 000000000000..b78f1b2ee3dc
> > --- /dev/null
> > +++ b/drivers/irqchip/irq-riscv-imsic-platform.c
> > @@ -0,0 +1,280 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +
> > +#include <linux/bitmap.h>
> > +#include <linux/cpu.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/irq.h>
> > +#include <linux/irqchip.h>
> > +#include <linux/irqdomain.h>
> > +#include <linux/module.h>
> > +#include <linux/msi.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/spinlock.h>
> > +#include <linux/smp.h>
> > +
> > +#include "irq-riscv-imsic-state.h"
> > +
> > +static int imsic_cpu_page_phys(unsigned int cpu,
> > +                            unsigned int guest_index,
> > +                            phys_addr_t *out_msi_pa)
> > +{
> > +     struct imsic_global_config *global;
> > +     struct imsic_local_config *local;
> > +
> > +     global = &imsic->global;
> > +     local = per_cpu_ptr(global->local, cpu);
> > +
> > +     if (BIT(global->guest_index_bits) <= guest_index)
> > +             return -EINVAL;
> > +
> > +     if (out_msi_pa)
> > +             *out_msi_pa = local->msi_pa +
> > +                           (guest_index * IMSIC_MMIO_PAGE_SZ);
> > +
> > +     return 0;
> > +}
> > +
> > +static int imsic_get_cpu(const struct cpumask *mask_val, bool force,
> > +                      unsigned int *out_target_cpu)
> > +{
> > +     unsigned int cpu;
> > +
> > +     if (force)
> > +             cpu = cpumask_first(mask_val);
> > +     else
> > +             cpu = cpumask_any_and(mask_val, cpu_online_mask);
> > +
> > +     if (cpu >= nr_cpu_ids)
> > +             return -EINVAL;
> > +
> > +     if (out_target_cpu)
> > +             *out_target_cpu = cpu;
> > +
> > +     return 0;
> > +}
> > +
> > +static void imsic_irq_mask(struct irq_data *d)
> > +{
> > +     unsigned long flags;
> > +
> > +     raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> > +     bitmap_clear(imsic->ids_enabled_bimap, d->hwirq, 1);
> > +     __imsic_id_disable(d->hwirq);
> > +     raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> > +
> > +     imsic_ids_remote_sync();
> > +}
> > +
> > +static void imsic_irq_unmask(struct irq_data *d)
> > +{
> > +     unsigned long flags;
> > +
> > +     raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> > +     bitmap_set(imsic->ids_enabled_bimap, d->hwirq, 1);
> > +     __imsic_id_enable(d->hwirq);
> > +     raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> > +
> > +     imsic_ids_remote_sync();
> > +}
> > +
> > +static void imsic_irq_compose_msi_msg(struct irq_data *d,
> > +                                   struct msi_msg *msg)
> > +{
> > +     phys_addr_t msi_addr;
> > +     unsigned int cpu;
> > +     int err;
> > +
> > +     cpu = imsic_id_get_target(d->hwirq);
> > +     if (WARN_ON(cpu == UINT_MAX))
> > +             return;
> > +
> > +     err = imsic_cpu_page_phys(cpu, 0, &msi_addr);
> > +     if (WARN_ON(err))
> > +             return;
> > +
> > +     msg->address_hi = upper_32_bits(msi_addr);
> > +     msg->address_lo = lower_32_bits(msi_addr);
> > +     msg->data = d->hwirq;
> > +}
> > +
> > +#ifdef CONFIG_SMP
> > +static int imsic_irq_set_affinity(struct irq_data *d,
> > +                               const struct cpumask *mask_val,
> > +                               bool force)
> > +{
> > +     unsigned int target_cpu;
> > +     int rc;
> > +
> > +     rc = imsic_get_cpu(mask_val, force, &target_cpu);
> > +     if (rc)
> > +             return rc;
> > +
> > +     imsic_id_set_target(d->hwirq, target_cpu);
> > +     irq_data_update_effective_affinity(d, cpumask_of(target_cpu));
>
> According to the “The RISC-V Advanced Interrupt Architecture Version
> 0.2-draft”，the "3.1 Interrupt files and interrupt identities" has
> following description.
>
> Thus the total number of MSI sources that can be separately distinguished
> within a system is potentially the product of the number of interrupt
> identities at a single interrupt
> file times the total number of interrupt files in the system, over all
> harts.
>
> In my opinion, the MSI interrupt number is a local interrupt number.
> However, when the above interrupt affinity is set, it is processed as a
> global interrupt number, which seems not comply with the above RISC-V
> specifications.

Treating IMSIC minor interrupt identities as global instead of local is a
design choice we made to integrate cleanly with Linux IRQ subsystem
because otherwise MSI interrupts will be percpu interrupts and we can't
steer device MSIs to different CPUs using set_irq_affinity().

Regards,
Anup

>
> > +
> > +     return IRQ_SET_MASK_OK;
> > +}
> > +#endif
> > +
> > +static struct irq_chip imsic_irq_base_chip = {
> > +     .name                   = "IMSIC-BASE",
> > +     .irq_mask               = imsic_irq_mask,
> > +     .irq_unmask             = imsic_irq_unmask,
> > +#ifdef CONFIG_SMP
> > +     .irq_set_affinity       = imsic_irq_set_affinity,
> > +#endif
> > +     .irq_compose_msi_msg    = imsic_irq_compose_msi_msg,
> > +     .flags                  = IRQCHIP_SKIP_SET_WAKE |
> > +                               IRQCHIP_MASK_ON_SUSPEND,
> > +};
> > +
> > +static int imsic_irq_domain_alloc(struct irq_domain *domain,
> > +                               unsigned int virq,
> > +                               unsigned int nr_irqs,
> > +                               void *args)
> > +{
> > +     int i, hwirq, err = 0;
> > +     unsigned int cpu;
> > +
> > +     err = imsic_get_cpu(cpu_online_mask, false, &cpu);
> > +     if (err)
> > +             return err;
> > +
> > +     hwirq = imsic_ids_alloc(get_count_order(nr_irqs));
> > +     if (hwirq < 0)
> > +             return hwirq;
> > +
> > +     for (i = 0; i < nr_irqs; i++) {
> > +             imsic_id_set_target(hwirq + i, cpu);
> > +             irq_domain_set_info(domain, virq + i, hwirq + i,
> > +                                 &imsic_irq_base_chip, imsic,
> > +                                 handle_simple_irq, NULL, NULL);
> > +             irq_set_noprobe(virq + i);
> > +             irq_set_affinity(virq + i, cpu_online_mask);
> > +             /*
> > +              * IMSIC does not implement irq_disable() so Linux interrupt
> > +              * subsystem will take a lazy approach for disabling an IMSIC
> > +              * interrupt. This means IMSIC interrupts are left unmasked
> > +              * upon system suspend and interrupts are not processed
> > +              * immediately upon system wake up. To tackle this, we disable
> > +              * the lazy approach for all IMSIC interrupts.
> > +              */
> > +             irq_set_status_flags(virq + i, IRQ_DISABLE_UNLAZY);
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +static void imsic_irq_domain_free(struct irq_domain *domain,
> > +                               unsigned int virq,
> > +                               unsigned int nr_irqs)
> > +{
> > +     struct irq_data *d = irq_domain_get_irq_data(domain, virq);
> > +
> > +     imsic_ids_free(d->hwirq, get_count_order(nr_irqs));
> > +     irq_domain_free_irqs_parent(domain, virq, nr_irqs);
> > +}
> > +
> > +static const struct irq_domain_ops imsic_base_domain_ops = {
> > +     .alloc          = imsic_irq_domain_alloc,
> > +     .free           = imsic_irq_domain_free,
> > +};
> > +
> > +static struct irq_chip imsic_plat_irq_chip = {
> > +     .name                   = "IMSIC-PLAT",
> > +};
> > +
> > +static struct msi_domain_ops imsic_plat_domain_ops = {
> > +};
> > +
> > +static struct msi_domain_info imsic_plat_domain_info = {
> > +     .flags  = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
> > +     .ops    = &imsic_plat_domain_ops,
> > +     .chip   = &imsic_plat_irq_chip,
> > +};
> > +
> > +static int imsic_irq_domains_init(struct device *dev)
> > +{
> > +     /* Create Base IRQ domain */
> > +     imsic->base_domain = irq_domain_create_tree(dev->fwnode,
> > +                                     &imsic_base_domain_ops, imsic);
> > +     if (!imsic->base_domain) {
> > +             dev_err(dev, "failed to create IMSIC base domain\n");
> > +             return -ENOMEM;
> > +     }
> > +     irq_domain_update_bus_token(imsic->base_domain, DOMAIN_BUS_NEXUS);
> > +
> > +     /* Create Platform MSI domain */
> > +     imsic->plat_domain = platform_msi_create_irq_domain(dev->fwnode,
> > +                                             &imsic_plat_domain_info,
> > +                                             imsic->base_domain);
> > +     if (!imsic->plat_domain) {
> > +             dev_err(dev, "failed to create IMSIC platform domain\n");
> > +             irq_domain_remove(imsic->base_domain);
> > +             return -ENOMEM;
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +static int imsic_platform_probe(struct platform_device *pdev)
> > +{
> > +     struct device *dev = &pdev->dev;
> > +     struct imsic_global_config *global;
> > +     int rc;
> > +
> > +     if (!imsic) {
> > +             dev_err(dev, "early driver not probed\n");
> > +             return -ENODEV;
> > +     }
> > +
> > +     if (imsic->base_domain) {
> > +             dev_err(dev, "irq domain already created\n");
> > +             return -ENODEV;
> > +     }
> > +
> > +     global = &imsic->global;
> > +
> > +     /* Initialize IRQ and MSI domains */
> > +     rc = imsic_irq_domains_init(dev);
> > +     if (rc) {
> > +             dev_err(dev, "failed to initialize IRQ and MSI domains\n");
> > +             return rc;
> > +     }
> > +
> > +     dev_info(dev, "  hart-index-bits: %d,  guest-index-bits: %d\n",
> > +              global->hart_index_bits, global->guest_index_bits);
> > +     dev_info(dev, " group-index-bits: %d, group-index-shift: %d\n",
> > +              global->group_index_bits, global->group_index_shift);
> > +     dev_info(dev, " mapped %d interrupts at base PPN %pa\n",
> > +              global->nr_ids, &global->base_addr);
> > +
> > +     return 0;
> > +}
> > +
> > +static const struct of_device_id imsic_platform_match[] = {
> > +     { .compatible = "riscv,imsics" },
> > +     {}
> > +};
> > +
> > +static struct platform_driver imsic_platform_driver = {
> > +     .driver = {
> > +             .name           = "riscv-imsic",
> > +             .of_match_table = imsic_platform_match,
> > +     },
> > +     .probe = imsic_platform_probe,
> > +};
> > +
> > +static int __init imsic_platform_init(void)
> > +{
> > +     /*
> > +      * Register IMSIC driver as early as possible so that IMSIC
> > +      * platform device is probed as soon as it is created.
> > +      */
> > +     return platform_driver_register(&imsic_platform_driver);
> > +}
> > +core_initcall(imsic_platform_init);

Re: [PATCH v8 10/16] irqchip/riscv-imsic: Add support for platform MSI irqdomain

[Anup Patel]

On Mon, Sep 25, 2023 at 6:31 PM Ruan Jinjie <ruanjinjie@huawei.com> wrote:
>
>
>
> On 2023/9/13 1:49, Anup Patel wrote:
> > The Linux platform MSI support requires a platform MSI irqdomain so
> > let us add a platform irqchip driver for RISC-V IMSIC which provides
> > a base IRQ domain and platform MSI domain. This driver assumes that
> > the IMSIC state is already initialized by the IMSIC early driver.
> >
> > Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> > ---
> >  drivers/irqchip/Makefile                   |   2 +-
> >  drivers/irqchip/irq-riscv-imsic-platform.c | 280 +++++++++++++++++++++
> >  2 files changed, 281 insertions(+), 1 deletion(-)
> >  create mode 100644 drivers/irqchip/irq-riscv-imsic-platform.c
> >
> > diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> > index d714724387ce..abca445a3229 100644
> > --- a/drivers/irqchip/Makefile
> > +++ b/drivers/irqchip/Makefile
> > @@ -95,7 +95,7 @@ obj-$(CONFIG_QCOM_MPM)                      += irq-qcom-mpm.o
> >  obj-$(CONFIG_CSKY_MPINTC)            += irq-csky-mpintc.o
> >  obj-$(CONFIG_CSKY_APB_INTC)          += irq-csky-apb-intc.o
> >  obj-$(CONFIG_RISCV_INTC)             += irq-riscv-intc.o
> > -obj-$(CONFIG_RISCV_IMSIC)            += irq-riscv-imsic-state.o irq-riscv-imsic-early.o
> > +obj-$(CONFIG_RISCV_IMSIC)            += irq-riscv-imsic-state.o irq-riscv-imsic-early.o irq-riscv-imsic-platform.o
> >  obj-$(CONFIG_SIFIVE_PLIC)            += irq-sifive-plic.o
> >  obj-$(CONFIG_IMX_IRQSTEER)           += irq-imx-irqsteer.o
> >  obj-$(CONFIG_IMX_INTMUX)             += irq-imx-intmux.o
> > diff --git a/drivers/irqchip/irq-riscv-imsic-platform.c b/drivers/irqchip/irq-riscv-imsic-platform.c
> > new file mode 100644
> > index 000000000000..b78f1b2ee3dc
> > --- /dev/null
> > +++ b/drivers/irqchip/irq-riscv-imsic-platform.c
> > @@ -0,0 +1,280 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +
> > +#include <linux/bitmap.h>
> > +#include <linux/cpu.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/irq.h>
> > +#include <linux/irqchip.h>
> > +#include <linux/irqdomain.h>
> > +#include <linux/module.h>
> > +#include <linux/msi.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/spinlock.h>
> > +#include <linux/smp.h>
> > +
> > +#include "irq-riscv-imsic-state.h"
> > +
> > +static int imsic_cpu_page_phys(unsigned int cpu,
> > +                            unsigned int guest_index,
> > +                            phys_addr_t *out_msi_pa)
> > +{
> > +     struct imsic_global_config *global;
> > +     struct imsic_local_config *local;
> > +
> > +     global = &imsic->global;
> > +     local = per_cpu_ptr(global->local, cpu);
> > +
> > +     if (BIT(global->guest_index_bits) <= guest_index)
> > +             return -EINVAL;
> > +
> > +     if (out_msi_pa)
> > +             *out_msi_pa = local->msi_pa +
> > +                           (guest_index * IMSIC_MMIO_PAGE_SZ);
> > +
> > +     return 0;
> > +}
> > +
> > +static int imsic_get_cpu(const struct cpumask *mask_val, bool force,
> > +                      unsigned int *out_target_cpu)
> > +{
> > +     unsigned int cpu;
> > +
> > +     if (force)
> > +             cpu = cpumask_first(mask_val);
> > +     else
> > +             cpu = cpumask_any_and(mask_val, cpu_online_mask);
> > +
> > +     if (cpu >= nr_cpu_ids)
> > +             return -EINVAL;
> > +
> > +     if (out_target_cpu)
> > +             *out_target_cpu = cpu;
> > +
> > +     return 0;
> > +}
> > +
> > +static void imsic_irq_mask(struct irq_data *d)
> > +{
> > +     unsigned long flags;
> > +
> > +     raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> > +     bitmap_clear(imsic->ids_enabled_bimap, d->hwirq, 1);
> > +     __imsic_id_disable(d->hwirq);
> > +     raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> > +
> > +     imsic_ids_remote_sync();
> > +}
> > +
> > +static void imsic_irq_unmask(struct irq_data *d)
> > +{
> > +     unsigned long flags;
> > +
> > +     raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> > +     bitmap_set(imsic->ids_enabled_bimap, d->hwirq, 1);
> > +     __imsic_id_enable(d->hwirq);
> > +     raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> > +
> > +     imsic_ids_remote_sync();
> > +}
> > +
> > +static void imsic_irq_compose_msi_msg(struct irq_data *d,
> > +                                   struct msi_msg *msg)
> > +{
> > +     phys_addr_t msi_addr;
> > +     unsigned int cpu;
> > +     int err;
> > +
> > +     cpu = imsic_id_get_target(d->hwirq);
> > +     if (WARN_ON(cpu == UINT_MAX))
> > +             return;
> > +
> > +     err = imsic_cpu_page_phys(cpu, 0, &msi_addr);
> > +     if (WARN_ON(err))
> > +             return;
> > +
> > +     msg->address_hi = upper_32_bits(msi_addr);
> > +     msg->address_lo = lower_32_bits(msi_addr);
> > +     msg->data = d->hwirq;
> > +}
> > +
> > +#ifdef CONFIG_SMP
> > +static int imsic_irq_set_affinity(struct irq_data *d,
> > +                               const struct cpumask *mask_val,
> > +                               bool force)
> > +{
> > +     unsigned int target_cpu;
> > +     int rc;
> > +
> > +     rc = imsic_get_cpu(mask_val, force, &target_cpu);
> > +     if (rc)
> > +             return rc;
> > +
> > +     imsic_id_set_target(d->hwirq, target_cpu);
> > +     irq_data_update_effective_affinity(d, cpumask_of(target_cpu));
>
> According to the “The RISC-V Advanced Interrupt Architecture Version
> 0.2-draft”，the "3.1 Interrupt files and interrupt identities" has
> following description.
>
> Thus the total number of MSI sources that can be separately distinguished
> within a system is potentially the product of the number of interrupt
> identities at a single interrupt
> file times the total number of interrupt files in the system, over all
> harts.
>
> In my opinion, the MSI interrupt number is a local interrupt number.
> However, when the above interrupt affinity is set, it is processed as a
> global interrupt number, which seems not comply with the above RISC-V
> specifications.

Treating IMSIC minor interrupt identities as global instead of local is a
design choice we made to integrate cleanly with Linux IRQ subsystem
because otherwise MSI interrupts will be percpu interrupts and we can't
steer device MSIs to different CPUs using set_irq_affinity().

Regards,
Anup

>
> > +
> > +     return IRQ_SET_MASK_OK;
> > +}
> > +#endif
> > +
> > +static struct irq_chip imsic_irq_base_chip = {
> > +     .name                   = "IMSIC-BASE",
> > +     .irq_mask               = imsic_irq_mask,
> > +     .irq_unmask             = imsic_irq_unmask,
> > +#ifdef CONFIG_SMP
> > +     .irq_set_affinity       = imsic_irq_set_affinity,
> > +#endif
> > +     .irq_compose_msi_msg    = imsic_irq_compose_msi_msg,
> > +     .flags                  = IRQCHIP_SKIP_SET_WAKE |
> > +                               IRQCHIP_MASK_ON_SUSPEND,
> > +};
> > +
> > +static int imsic_irq_domain_alloc(struct irq_domain *domain,
> > +                               unsigned int virq,
> > +                               unsigned int nr_irqs,
> > +                               void *args)
> > +{
> > +     int i, hwirq, err = 0;
> > +     unsigned int cpu;
> > +
> > +     err = imsic_get_cpu(cpu_online_mask, false, &cpu);
> > +     if (err)
> > +             return err;
> > +
> > +     hwirq = imsic_ids_alloc(get_count_order(nr_irqs));
> > +     if (hwirq < 0)
> > +             return hwirq;
> > +
> > +     for (i = 0; i < nr_irqs; i++) {
> > +             imsic_id_set_target(hwirq + i, cpu);
> > +             irq_domain_set_info(domain, virq + i, hwirq + i,
> > +                                 &imsic_irq_base_chip, imsic,
> > +                                 handle_simple_irq, NULL, NULL);
> > +             irq_set_noprobe(virq + i);
> > +             irq_set_affinity(virq + i, cpu_online_mask);
> > +             /*
> > +              * IMSIC does not implement irq_disable() so Linux interrupt
> > +              * subsystem will take a lazy approach for disabling an IMSIC
> > +              * interrupt. This means IMSIC interrupts are left unmasked
> > +              * upon system suspend and interrupts are not processed
> > +              * immediately upon system wake up. To tackle this, we disable
> > +              * the lazy approach for all IMSIC interrupts.
> > +              */
> > +             irq_set_status_flags(virq + i, IRQ_DISABLE_UNLAZY);
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +static void imsic_irq_domain_free(struct irq_domain *domain,
> > +                               unsigned int virq,
> > +                               unsigned int nr_irqs)
> > +{
> > +     struct irq_data *d = irq_domain_get_irq_data(domain, virq);
> > +
> > +     imsic_ids_free(d->hwirq, get_count_order(nr_irqs));
> > +     irq_domain_free_irqs_parent(domain, virq, nr_irqs);
> > +}
> > +
> > +static const struct irq_domain_ops imsic_base_domain_ops = {
> > +     .alloc          = imsic_irq_domain_alloc,
> > +     .free           = imsic_irq_domain_free,
> > +};
> > +
> > +static struct irq_chip imsic_plat_irq_chip = {
> > +     .name                   = "IMSIC-PLAT",
> > +};
> > +
> > +static struct msi_domain_ops imsic_plat_domain_ops = {
> > +};
> > +
> > +static struct msi_domain_info imsic_plat_domain_info = {
> > +     .flags  = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
> > +     .ops    = &imsic_plat_domain_ops,
> > +     .chip   = &imsic_plat_irq_chip,
> > +};
> > +
> > +static int imsic_irq_domains_init(struct device *dev)
> > +{
> > +     /* Create Base IRQ domain */
> > +     imsic->base_domain = irq_domain_create_tree(dev->fwnode,
> > +                                     &imsic_base_domain_ops, imsic);
> > +     if (!imsic->base_domain) {
> > +             dev_err(dev, "failed to create IMSIC base domain\n");
> > +             return -ENOMEM;
> > +     }
> > +     irq_domain_update_bus_token(imsic->base_domain, DOMAIN_BUS_NEXUS);
> > +
> > +     /* Create Platform MSI domain */
> > +     imsic->plat_domain = platform_msi_create_irq_domain(dev->fwnode,
> > +                                             &imsic_plat_domain_info,
> > +                                             imsic->base_domain);
> > +     if (!imsic->plat_domain) {
> > +             dev_err(dev, "failed to create IMSIC platform domain\n");
> > +             irq_domain_remove(imsic->base_domain);
> > +             return -ENOMEM;
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +static int imsic_platform_probe(struct platform_device *pdev)
> > +{
> > +     struct device *dev = &pdev->dev;
> > +     struct imsic_global_config *global;
> > +     int rc;
> > +
> > +     if (!imsic) {
> > +             dev_err(dev, "early driver not probed\n");
> > +             return -ENODEV;
> > +     }
> > +
> > +     if (imsic->base_domain) {
> > +             dev_err(dev, "irq domain already created\n");
> > +             return -ENODEV;
> > +     }
> > +
> > +     global = &imsic->global;
> > +
> > +     /* Initialize IRQ and MSI domains */
> > +     rc = imsic_irq_domains_init(dev);
> > +     if (rc) {
> > +             dev_err(dev, "failed to initialize IRQ and MSI domains\n");
> > +             return rc;
> > +     }
> > +
> > +     dev_info(dev, "  hart-index-bits: %d,  guest-index-bits: %d\n",
> > +              global->hart_index_bits, global->guest_index_bits);
> > +     dev_info(dev, " group-index-bits: %d, group-index-shift: %d\n",
> > +              global->group_index_bits, global->group_index_shift);
> > +     dev_info(dev, " mapped %d interrupts at base PPN %pa\n",
> > +              global->nr_ids, &global->base_addr);
> > +
> > +     return 0;
> > +}
> > +
> > +static const struct of_device_id imsic_platform_match[] = {
> > +     { .compatible = "riscv,imsics" },
> > +     {}
> > +};
> > +
> > +static struct platform_driver imsic_platform_driver = {
> > +     .driver = {
> > +             .name           = "riscv-imsic",
> > +             .of_match_table = imsic_platform_match,
> > +     },
> > +     .probe = imsic_platform_probe,
> > +};
> > +
> > +static int __init imsic_platform_init(void)
> > +{
> > +     /*
> > +      * Register IMSIC driver as early as possible so that IMSIC
> > +      * platform device is probed as soon as it is created.
> > +      */
> > +     return platform_driver_register(&imsic_platform_driver);
> > +}
> > +core_initcall(imsic_platform_init);

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Re: [PATCH v8 02/16] RISC-V: Add riscv_get_intc_hartid() function

[Anup Patel]

On Mon, Sep 25, 2023 at 1:08 PM Sunil V L <sunilvl@ventanamicro.com> wrote:
>
> Hi Anup,
>
> On Tue, Sep 12, 2023 at 11:19:14PM +0530, Anup Patel wrote:
> > We add a common riscv_get_intc_hartid() which help device drivers to
> > get hartid of the HART associated with a INTC (i.e. local interrupt
> > controller) fwnode. This new function is more generic compared to
> > the existing riscv_of_parent_hartid() function hence we also replace
> > use of riscv_of_parent_hartid() with riscv_get_intc_hartid().
> >
> > Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> > ---
> >  arch/riscv/include/asm/processor.h |  4 +++-
> >  arch/riscv/kernel/cpu.c            | 13 ++++++++++++-
> >  drivers/irqchip/irq-riscv-intc.c   |  2 +-
> >  drivers/irqchip/irq-sifive-plic.c  |  3 ++-
> >  4 files changed, 18 insertions(+), 4 deletions(-)
> >
> > diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
> > index 3e23e1786d05..3ce64b3bea4e 100644
> > --- a/arch/riscv/include/asm/processor.h
> > +++ b/arch/riscv/include/asm/processor.h
> > @@ -119,7 +119,9 @@ static inline void wait_for_interrupt(void)
> >  struct device_node;
> >  int riscv_of_processor_hartid(struct device_node *node, unsigned long *hartid);
> >  int riscv_early_of_processor_hartid(struct device_node *node, unsigned long *hartid);
> > -int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid);
> > +
> > +struct fwnode_handle;
> > +int riscv_get_intc_hartid(struct fwnode_handle *node, unsigned long *hartid);
> >
> >  extern void riscv_fill_hwcap(void);
> >  extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
> > diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
> > index 157ace8b262c..ee583eac3c5b 100644
> > --- a/arch/riscv/kernel/cpu.c
> > +++ b/arch/riscv/kernel/cpu.c
> > @@ -123,7 +123,8 @@ int __init riscv_early_of_processor_hartid(struct device_node *node, unsigned lo
> >   * To achieve this, we walk up the DT tree until we find an active
> >   * RISC-V core (HART) node and extract the cpuid from it.
> >   */
> > -int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid)
> > +static int riscv_of_parent_hartid(struct device_node *node,
> > +                               unsigned long *hartid)
> >  {
> >       for (; node; node = node->parent) {
> >               if (of_device_is_compatible(node, "riscv")) {
> > @@ -139,6 +140,16 @@ int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid)
> >       return -1;
> >  }
> >
> > +/* Find hart ID of the INTC fwnode. */
> > +int riscv_get_intc_hartid(struct fwnode_handle *node, unsigned long *hartid)
> > +{
> > +     /* Extend this function ACPI in the future. */
>
> As per Marc's feedback, we can't use swnode for ACPI irchips. So, there
> is no need to create this wrapper function and this patch can be
> dropped.

Okay, I will drop this patch.

Regards,
Anup

>
> Thanks,
> Sunil
>
> > +     if (!is_of_node(node))
> > +             return -ENODEV;
> > +
> > +     return riscv_of_parent_hartid(to_of_node(node), hartid);
> > +}
> > +
> >  DEFINE_PER_CPU(struct riscv_cpuinfo, riscv_cpuinfo);
> >
> >  unsigned long riscv_cached_mvendorid(unsigned int cpu_id)
> > diff --git a/drivers/irqchip/irq-riscv-intc.c b/drivers/irqchip/irq-riscv-intc.c
> > index 4adeee1bc391..65f4a2afb381 100644
> > --- a/drivers/irqchip/irq-riscv-intc.c
> > +++ b/drivers/irqchip/irq-riscv-intc.c
> > @@ -143,7 +143,7 @@ static int __init riscv_intc_init(struct device_node *node,
> >       int rc;
> >       unsigned long hartid;
> >
> > -     rc = riscv_of_parent_hartid(node, &hartid);
> > +     rc = riscv_get_intc_hartid(of_fwnode_handle(node), &hartid);
> >       if (rc < 0) {
> >               pr_warn("unable to find hart id for %pOF\n", node);
> >               return 0;
> > diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
> > index e1484905b7bd..56b0544b1f27 100644
> > --- a/drivers/irqchip/irq-sifive-plic.c
> > +++ b/drivers/irqchip/irq-sifive-plic.c
> > @@ -477,7 +477,8 @@ static int __init __plic_init(struct device_node *node,
> >                       continue;
> >               }
> >
> > -             error = riscv_of_parent_hartid(parent.np, &hartid);
> > +             error = riscv_get_intc_hartid(of_fwnode_handle(parent.np),
> > +                                           &hartid);
> >               if (error < 0) {
> >                       pr_warn("failed to parse hart ID for context %d.\n", i);
> >                       continue;
> > --
> > 2.34.1
> >

Re: [PATCH v8 02/16] RISC-V: Add riscv_get_intc_hartid() function

[Anup Patel]

On Mon, Sep 25, 2023 at 1:08 PM Sunil V L <sunilvl@ventanamicro.com> wrote:
>
> Hi Anup,
>
> On Tue, Sep 12, 2023 at 11:19:14PM +0530, Anup Patel wrote:
> > We add a common riscv_get_intc_hartid() which help device drivers to
> > get hartid of the HART associated with a INTC (i.e. local interrupt
> > controller) fwnode. This new function is more generic compared to
> > the existing riscv_of_parent_hartid() function hence we also replace
> > use of riscv_of_parent_hartid() with riscv_get_intc_hartid().
> >
> > Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> > ---
> >  arch/riscv/include/asm/processor.h |  4 +++-
> >  arch/riscv/kernel/cpu.c            | 13 ++++++++++++-
> >  drivers/irqchip/irq-riscv-intc.c   |  2 +-
> >  drivers/irqchip/irq-sifive-plic.c  |  3 ++-
> >  4 files changed, 18 insertions(+), 4 deletions(-)
> >
> > diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
> > index 3e23e1786d05..3ce64b3bea4e 100644
> > --- a/arch/riscv/include/asm/processor.h
> > +++ b/arch/riscv/include/asm/processor.h
> > @@ -119,7 +119,9 @@ static inline void wait_for_interrupt(void)
> >  struct device_node;
> >  int riscv_of_processor_hartid(struct device_node *node, unsigned long *hartid);
> >  int riscv_early_of_processor_hartid(struct device_node *node, unsigned long *hartid);
> > -int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid);
> > +
> > +struct fwnode_handle;
> > +int riscv_get_intc_hartid(struct fwnode_handle *node, unsigned long *hartid);
> >
> >  extern void riscv_fill_hwcap(void);
> >  extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
> > diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
> > index 157ace8b262c..ee583eac3c5b 100644
> > --- a/arch/riscv/kernel/cpu.c
> > +++ b/arch/riscv/kernel/cpu.c
> > @@ -123,7 +123,8 @@ int __init riscv_early_of_processor_hartid(struct device_node *node, unsigned lo
> >   * To achieve this, we walk up the DT tree until we find an active
> >   * RISC-V core (HART) node and extract the cpuid from it.
> >   */
> > -int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid)
> > +static int riscv_of_parent_hartid(struct device_node *node,
> > +                               unsigned long *hartid)
> >  {
> >       for (; node; node = node->parent) {
> >               if (of_device_is_compatible(node, "riscv")) {
> > @@ -139,6 +140,16 @@ int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid)
> >       return -1;
> >  }
> >
> > +/* Find hart ID of the INTC fwnode. */
> > +int riscv_get_intc_hartid(struct fwnode_handle *node, unsigned long *hartid)
> > +{
> > +     /* Extend this function ACPI in the future. */
>
> As per Marc's feedback, we can't use swnode for ACPI irchips. So, there
> is no need to create this wrapper function and this patch can be
> dropped.

Okay, I will drop this patch.

Regards,
Anup

>
> Thanks,
> Sunil
>
> > +     if (!is_of_node(node))
> > +             return -ENODEV;
> > +
> > +     return riscv_of_parent_hartid(to_of_node(node), hartid);
> > +}
> > +
> >  DEFINE_PER_CPU(struct riscv_cpuinfo, riscv_cpuinfo);
> >
> >  unsigned long riscv_cached_mvendorid(unsigned int cpu_id)
> > diff --git a/drivers/irqchip/irq-riscv-intc.c b/drivers/irqchip/irq-riscv-intc.c
> > index 4adeee1bc391..65f4a2afb381 100644
> > --- a/drivers/irqchip/irq-riscv-intc.c
> > +++ b/drivers/irqchip/irq-riscv-intc.c
> > @@ -143,7 +143,7 @@ static int __init riscv_intc_init(struct device_node *node,
> >       int rc;
> >       unsigned long hartid;
> >
> > -     rc = riscv_of_parent_hartid(node, &hartid);
> > +     rc = riscv_get_intc_hartid(of_fwnode_handle(node), &hartid);
> >       if (rc < 0) {
> >               pr_warn("unable to find hart id for %pOF\n", node);
> >               return 0;
> > diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
> > index e1484905b7bd..56b0544b1f27 100644
> > --- a/drivers/irqchip/irq-sifive-plic.c
> > +++ b/drivers/irqchip/irq-sifive-plic.c
> > @@ -477,7 +477,8 @@ static int __init __plic_init(struct device_node *node,
> >                       continue;
> >               }
> >
> > -             error = riscv_of_parent_hartid(parent.np, &hartid);
> > +             error = riscv_get_intc_hartid(of_fwnode_handle(parent.np),
> > +                                           &hartid);
> >               if (error < 0) {
> >                       pr_warn("failed to parse hart ID for context %d.\n", i);
> >                       continue;
> > --
> > 2.34.1
> >

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Re: [PATCH v8 09/16] irqchip: Add RISC-V incoming MSI controller early driver

[Anup Patel]

On Mon, Sep 25, 2023 at 1:19 PM Sunil V L <sunilvl@ventanamicro.com> wrote:
>
> Hi Anup,
>
> On Tue, Sep 12, 2023 at 11:19:21PM +0530, Anup Patel wrote:
> > The RISC-V advanced interrupt architecture (AIA) specification
> > defines a new MSI controller called incoming message signalled
> > interrupt controller (IMSIC) which manages MSI on per-HART (or
> > per-CPU) basis. It also supports IPIs as software injected MSIs.
> > (For more details refer https://github.com/riscv/riscv-aia)
> >
> > Let us add an early irqchip driver for RISC-V IMSIC which sets
> > up the IMSIC state and provide IPIs.
> >
> > Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> > ---
> >  drivers/irqchip/Kconfig                 |   7 +-
> >  drivers/irqchip/Makefile                |   1 +
> >  drivers/irqchip/irq-riscv-imsic-early.c | 258 ++++++++++++
> >  drivers/irqchip/irq-riscv-imsic-state.c | 523 ++++++++++++++++++++++++
> >  drivers/irqchip/irq-riscv-imsic-state.h |  66 +++
> >  include/linux/irqchip/riscv-imsic.h     |  86 ++++
> >  6 files changed, 940 insertions(+), 1 deletion(-)
> >  create mode 100644 drivers/irqchip/irq-riscv-imsic-early.c
> >  create mode 100644 drivers/irqchip/irq-riscv-imsic-state.c
> >  create mode 100644 drivers/irqchip/irq-riscv-imsic-state.h
> >  create mode 100644 include/linux/irqchip/riscv-imsic.h
> >
> > diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> > index f7149d0f3d45..ee99aacbefcc 100644
> > --- a/drivers/irqchip/Kconfig
> > +++ b/drivers/irqchip/Kconfig
> > @@ -30,7 +30,6 @@ config ARM_GIC_V2M
> >
> >  config GIC_NON_BANKED
> >       bool
> > -
> >  config ARM_GIC_V3
> >       bool
> >       select IRQ_DOMAIN_HIERARCHY
> > @@ -546,6 +545,12 @@ config SIFIVE_PLIC
> >       select IRQ_DOMAIN_HIERARCHY
> >       select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
> >
> > +config RISCV_IMSIC
> > +     bool
> > +     depends on RISCV
> > +     select IRQ_DOMAIN_HIERARCHY
> > +     select GENERIC_MSI_IRQ
> > +
> >  config EXYNOS_IRQ_COMBINER
> >       bool "Samsung Exynos IRQ combiner support" if COMPILE_TEST
> >       depends on (ARCH_EXYNOS && ARM) || COMPILE_TEST
> > diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> > index ffd945fe71aa..d714724387ce 100644
> > --- a/drivers/irqchip/Makefile
> > +++ b/drivers/irqchip/Makefile
> > @@ -95,6 +95,7 @@ obj-$(CONFIG_QCOM_MPM)                      += irq-qcom-mpm.o
> >  obj-$(CONFIG_CSKY_MPINTC)            += irq-csky-mpintc.o
> >  obj-$(CONFIG_CSKY_APB_INTC)          += irq-csky-apb-intc.o
> >  obj-$(CONFIG_RISCV_INTC)             += irq-riscv-intc.o
> > +obj-$(CONFIG_RISCV_IMSIC)            += irq-riscv-imsic-state.o irq-riscv-imsic-early.o
> >  obj-$(CONFIG_SIFIVE_PLIC)            += irq-sifive-plic.o
> >  obj-$(CONFIG_IMX_IRQSTEER)           += irq-imx-irqsteer.o
> >  obj-$(CONFIG_IMX_INTMUX)             += irq-imx-intmux.o
> > diff --git a/drivers/irqchip/irq-riscv-imsic-early.c b/drivers/irqchip/irq-riscv-imsic-early.c
> > new file mode 100644
> > index 000000000000..1de89ce1ec2f
> > --- /dev/null
> > +++ b/drivers/irqchip/irq-riscv-imsic-early.c
> > @@ -0,0 +1,258 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +
> > +#define pr_fmt(fmt) "riscv-imsic: " fmt
> > +#include <linux/cpu.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/io.h>
> > +#include <linux/irq.h>
> > +#include <linux/irqchip.h>
> > +#include <linux/irqchip/chained_irq.h>
> > +#include <linux/module.h>
> > +#include <linux/spinlock.h>
> > +#include <linux/smp.h>
> > +
> > +#include "irq-riscv-imsic-state.h"
> > +
> > +/*
> > + * The IMSIC driver uses 1 IPI for ID synchronization and
> > + * arch/riscv/kernel/smp.c require 6 IPIs so we fix the
> > + * total number of IPIs to 8.
> > + */
> > +#define IMSIC_NR_IPI                         8
> > +
> > +static int imsic_parent_irq;
> > +
> > +#ifdef CONFIG_SMP
> > +static irqreturn_t imsic_ids_sync_handler(int irq, void *data)
> > +{
> > +     imsic_ids_local_sync();
> > +     return IRQ_HANDLED;
> > +}
> > +
> > +void imsic_ids_remote_sync(void)
> > +{
> > +     struct cpumask amask;
> > +
> > +     /*
> > +      * We simply inject ID synchronization IPI to all target CPUs
> > +      * except current CPU. The ipi_send_mask() implementation of
> > +      * IPI mux will inject ID synchronization IPI only for CPUs
> > +      * that have enabled it so offline CPUs won't receive IPI.
> > +      * An offline CPU will unconditionally synchronize IDs through
> > +      * imsic_starting_cpu() when the CPU is brought up.
> > +      */
> > +     cpumask_andnot(&amask, cpu_online_mask, cpumask_of(smp_processor_id()));
> > +     __ipi_send_mask(imsic->ipi_lsync_desc, &amask);
> > +}
> > +
> > +static void imsic_ipi_send(unsigned int cpu)
> > +{
> > +     struct imsic_local_config *local =
> > +                             per_cpu_ptr(imsic->global.local, cpu);
> > +
> > +     writel(imsic->ipi_id, local->msi_va);
> > +}
> > +
> > +static void imsic_ipi_starting_cpu(void)
> > +{
> > +     /* Enable IPIs for current CPU. */
> > +     __imsic_id_enable(imsic->ipi_id);
> > +
> > +     /* Enable virtual IPI used for IMSIC ID synchronization */
> > +     enable_percpu_irq(imsic->ipi_virq, 0);
> > +}
> > +
> > +static void imsic_ipi_dying_cpu(void)
> > +{
> > +     /*
> > +      * Disable virtual IPI used for IMSIC ID synchronization so
> > +      * that we don't receive ID synchronization requests.
> > +      */
> > +     disable_percpu_irq(imsic->ipi_virq);
> > +}
> > +
> > +static int __init imsic_ipi_domain_init(void)
> > +{
> > +     int virq;
> > +
> > +     /* Allocate interrupt identity for IPIs */
> > +     virq = imsic_ids_alloc(get_count_order(1));
> > +     if (virq < 0)
> > +             return virq;
> > +     imsic->ipi_id = virq;
> > +
> > +     /* Create IMSIC IPI multiplexing */
> > +     virq = ipi_mux_create(IMSIC_NR_IPI, imsic_ipi_send);
> > +     if (virq <= 0) {
> > +             imsic_ids_free(imsic->ipi_id, get_count_order(1));
> > +             return (virq < 0) ? virq : -ENOMEM;
> > +     }
> > +     imsic->ipi_virq = virq;
> > +
> > +     /* First vIRQ is used for IMSIC ID synchronization */
> > +     virq = request_percpu_irq(imsic->ipi_virq, imsic_ids_sync_handler,
> > +                               "riscv-imsic-lsync", imsic->global.local);
> > +     if (virq) {
> > +             imsic_ids_free(imsic->ipi_id, get_count_order(1));
> > +             return virq;
> > +     }
> > +     irq_set_status_flags(imsic->ipi_virq, IRQ_HIDDEN);
> > +     imsic->ipi_lsync_desc = irq_to_desc(imsic->ipi_virq);
> > +
> > +     /* Set vIRQ range */
> > +     riscv_ipi_set_virq_range(imsic->ipi_virq + 1, IMSIC_NR_IPI - 1, true);
> > +
> > +     /* Announce that IMSIC is providing IPIs */
> > +     pr_info("%pfwP: providing IPIs using interrupt %d\n",
> > +             imsic->fwnode, imsic->ipi_id);
> > +
> > +     return 0;
> > +}
> > +#else
> > +static void imsic_ipi_starting_cpu(void)
> > +{
> > +}
> > +
> > +static void imsic_ipi_dying_cpu(void)
> > +{
> > +}
> > +
> > +static int __init imsic_ipi_domain_init(void)
> > +{
> > +     /* Clear the IPI id because we are not using IPIs */
> > +     imsic->ipi_id = 0;
> > +     return 0;
> > +}
> > +#endif
> > +
> > +/*
> > + * To handle an interrupt, we read the TOPEI CSR and write zero in one
> > + * instruction. If TOPEI CSR is non-zero then we translate TOPEI.ID to
> > + * Linux interrupt number and let Linux IRQ subsystem handle it.
> > + */
> > +static void imsic_handle_irq(struct irq_desc *desc)
> > +{
> > +     struct irq_chip *chip = irq_desc_get_chip(desc);
> > +     irq_hw_number_t hwirq;
> > +     int err;
> > +
> > +     chained_irq_enter(chip, desc);
> > +
> > +     while ((hwirq = csr_swap(CSR_TOPEI, 0))) {
> > +             hwirq = hwirq >> TOPEI_ID_SHIFT;
> > +
> > +             if (hwirq == imsic->ipi_id) {
> > +#ifdef CONFIG_SMP
> > +                     ipi_mux_process();
> > +#endif
> > +                     continue;
> > +             }
> > +
> > +             if (unlikely(!imsic->base_domain))
> > +                     continue;
> > +
> > +             err = generic_handle_domain_irq(imsic->base_domain, hwirq);
> > +             if (unlikely(err))
> > +                     pr_warn_ratelimited(
> > +                             "hwirq %lu mapping not found\n", hwirq);
> > +     }
> > +
> > +     chained_irq_exit(chip, desc);
> > +}
> > +
> > +static int imsic_starting_cpu(unsigned int cpu)
> > +{
> > +     /* Enable per-CPU parent interrupt */
> > +     enable_percpu_irq(imsic_parent_irq,
> > +                       irq_get_trigger_type(imsic_parent_irq));
> > +
> > +     /* Setup IPIs */
> > +     imsic_ipi_starting_cpu();
> > +
> > +     /*
> > +      * Interrupts identities might have been enabled/disabled while
> > +      * this CPU was not running so sync-up local enable/disable state.
> > +      */
> > +     imsic_ids_local_sync();
> > +
> > +     /* Enable local interrupt delivery */
> > +     imsic_ids_local_delivery(true);
> > +
> > +     return 0;
> > +}
> > +
> > +static int imsic_dying_cpu(unsigned int cpu)
> > +{
> > +     /* Cleanup IPIs */
> > +     imsic_ipi_dying_cpu();
> > +
> > +     return 0;
> > +}
> > +
> > +static int __init imsic_early_probe(struct fwnode_handle *fwnode)
>
> Can this imsic_early_probe() take an additional pointer as parameter?
> This parameter can be NULL for DT and we can use to pass the MADT
> structure in case of ACPI since fwnode in ACPI will not have any
> properties. The parameter needs to be passed to imsic_setup_state()
> also.

Instead, I am thinking of moving the imsic_setup_state() call to
imsic_early_dt_init() so that we can directly pass extra parameters
from imsic_early_dt_init().

>
> > +{
> > +     int rc;
> > +     struct irq_domain *domain;
> > +
> > +     /* Setup IMSIC state */
> > +     rc = imsic_setup_state(fwnode);
> > +     if (rc) {
> > +             pr_err("%pfwP: failed to setup state (error %d)\n",
> > +                     fwnode, rc);
> > +             return rc;
> > +     }
> > +
> > +     /* Find parent domain and register chained handler */
> > +     domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
> > +                                       DOMAIN_BUS_ANY);
> > +     if (!domain) {
> > +             pr_err("%pfwP: Failed to find INTC domain\n", fwnode);
> > +             return -ENOENT;
> > +     }
> > +     imsic_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT);
> > +     if (!imsic_parent_irq) {
> > +             pr_err("%pfwP: Failed to create INTC mapping\n", fwnode);
> > +             return -ENOENT;
> > +     }
> > +     irq_set_chained_handler(imsic_parent_irq, imsic_handle_irq);
> > +
> > +     /* Initialize IPI domain */
> > +     rc = imsic_ipi_domain_init();
> > +     if (rc) {
> > +             pr_err("%pfwP: Failed to initialize IPI domain\n", fwnode);
> > +             return rc;
> > +     }
> > +
> > +     /*
> > +      * Setup cpuhp state (must be done after setting imsic_parent_irq)
> > +      *
> > +      * Don't disable per-CPU IMSIC file when CPU goes offline
> > +      * because this affects IPI and the masking/unmasking of
> > +      * virtual IPIs is done via generic IPI-Mux
> > +      */
> > +     cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
> > +                       "irqchip/riscv/imsic:starting",
> > +                       imsic_starting_cpu, imsic_dying_cpu);
> > +
> > +     return 0;
> > +}
> > +
> > +static int __init imsic_early_dt_init(struct device_node *node,
> > +                                   struct device_node *parent)
> > +{
> > +     int rc;
> > +
> > +     /* Do early setup of IMSIC state and IPIs */
> > +     rc = imsic_early_probe(&node->fwnode);
> > +     if (rc)
> > +             return rc;
> > +
> > +     /* Ensure that OF platform device gets probed */
> > +     of_node_clear_flag(node, OF_POPULATED);
> > +     return 0;
> > +}
> > +IRQCHIP_DECLARE(riscv_imsic, "riscv,imsics", imsic_early_dt_init);
> > diff --git a/drivers/irqchip/irq-riscv-imsic-state.c b/drivers/irqchip/irq-riscv-imsic-state.c
> > new file mode 100644
> > index 000000000000..412b5b919dcc
> > --- /dev/null
> > +++ b/drivers/irqchip/irq-riscv-imsic-state.c
> > @@ -0,0 +1,523 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +
> > +#define pr_fmt(fmt) "riscv-imsic: " fmt
> > +#include <linux/bitmap.h>
> > +#include <linux/module.h>
> > +#include <linux/of_address.h>
> > +#include <linux/spinlock.h>
> > +#include <linux/smp.h>
> > +#include <asm/hwcap.h>
> > +
> > +#include "irq-riscv-imsic-state.h"
> > +
> > +#define IMSIC_DISABLE_EIDELIVERY             0
> > +#define IMSIC_ENABLE_EIDELIVERY                      1
> > +#define IMSIC_DISABLE_EITHRESHOLD            1
> > +#define IMSIC_ENABLE_EITHRESHOLD             0
> > +
> > +#define imsic_csr_write(__c, __v)            \
> > +do {                                         \
> > +     csr_write(CSR_ISELECT, __c);            \
> > +     csr_write(CSR_IREG, __v);               \
> > +} while (0)
> > +
> > +#define imsic_csr_read(__c)                  \
> > +({                                           \
> > +     unsigned long __v;                      \
> > +     csr_write(CSR_ISELECT, __c);            \
> > +     __v = csr_read(CSR_IREG);               \
> > +     __v;                                    \
> > +})
> > +
> > +#define imsic_csr_set(__c, __v)                      \
> > +do {                                         \
> > +     csr_write(CSR_ISELECT, __c);            \
> > +     csr_set(CSR_IREG, __v);                 \
> > +} while (0)
> > +
> > +#define imsic_csr_clear(__c, __v)            \
> > +do {                                         \
> > +     csr_write(CSR_ISELECT, __c);            \
> > +     csr_clear(CSR_IREG, __v);               \
> > +} while (0)
> > +
> > +struct imsic_priv *imsic;
> > +
> > +const struct imsic_global_config *imsic_get_global_config(void)
> > +{
> > +     return (imsic) ? &imsic->global : NULL;
> > +}
> > +EXPORT_SYMBOL_GPL(imsic_get_global_config);
> > +
> > +void __imsic_eix_update(unsigned long base_id,
> > +                     unsigned long num_id, bool pend, bool val)
> > +{
> > +     unsigned long i, isel, ireg;
> > +     unsigned long id = base_id, last_id = base_id + num_id;
> > +
> > +     while (id < last_id) {
> > +             isel = id / BITS_PER_LONG;
> > +             isel *= BITS_PER_LONG / IMSIC_EIPx_BITS;
> > +             isel += (pend) ? IMSIC_EIP0 : IMSIC_EIE0;
> > +
> > +             ireg = 0;
> > +             for (i = id & (__riscv_xlen - 1);
> > +                  (id < last_id) && (i < __riscv_xlen); i++) {
> > +                     ireg |= BIT(i);
> > +                     id++;
> > +             }
> > +
> > +             /*
> > +              * The IMSIC EIEx and EIPx registers are indirectly
> > +              * accessed via using ISELECT and IREG CSRs so we
> > +              * need to access these CSRs without getting preempted.
> > +              *
> > +              * All existing users of this function call this
> > +              * function with local IRQs disabled so we don't
> > +              * need to do anything special here.
> > +              */
> > +             if (val)
> > +                     imsic_csr_set(isel, ireg);
> > +             else
> > +                     imsic_csr_clear(isel, ireg);
> > +     }
> > +}
> > +
> > +void imsic_id_set_target(unsigned int id, unsigned int target_cpu)
> > +{
> > +     unsigned long flags;
> > +
> > +     raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> > +     imsic->ids_target_cpu[id] = target_cpu;
> > +     raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> > +}
> > +
> > +unsigned int imsic_id_get_target(unsigned int id)
> > +{
> > +     unsigned int ret;
> > +     unsigned long flags;
> > +
> > +     raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> > +     ret = imsic->ids_target_cpu[id];
> > +     raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> > +
> > +     return ret;
> > +}
> > +
> > +void imsic_ids_local_sync(void)
> > +{
> > +     int i;
> > +     unsigned long flags;
> > +
> > +     raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> > +     for (i = 1; i <= imsic->global.nr_ids; i++) {
> > +             if (imsic->ipi_id == i)
> > +                     continue;
> > +
> > +             if (test_bit(i, imsic->ids_enabled_bimap))
> > +                     __imsic_id_enable(i);
> > +             else
> > +                     __imsic_id_disable(i);
> > +     }
> > +     raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> > +}
> > +
> > +void imsic_ids_local_delivery(bool enable)
> > +{
> > +     if (enable) {
> > +             imsic_csr_write(IMSIC_EITHRESHOLD, IMSIC_ENABLE_EITHRESHOLD);
> > +             imsic_csr_write(IMSIC_EIDELIVERY, IMSIC_ENABLE_EIDELIVERY);
> > +     } else {
> > +             imsic_csr_write(IMSIC_EIDELIVERY, IMSIC_DISABLE_EIDELIVERY);
> > +             imsic_csr_write(IMSIC_EITHRESHOLD, IMSIC_DISABLE_EITHRESHOLD);
> > +     }
> > +}
> > +
> > +int imsic_ids_alloc(unsigned int order)
> > +{
> > +     int ret;
> > +     unsigned long flags;
> > +
> > +     raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> > +     ret = bitmap_find_free_region(imsic->ids_used_bimap,
> > +                                   imsic->global.nr_ids + 1, order);
> > +     raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> > +
> > +     return ret;
> > +}
> > +
> > +void imsic_ids_free(unsigned int base_id, unsigned int order)
> > +{
> > +     unsigned long flags;
> > +
> > +     raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> > +     bitmap_release_region(imsic->ids_used_bimap, base_id, order);
> > +     raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> > +}
> > +
> > +static int __init imsic_ids_init(void)
> > +{
> > +     int i;
> > +     struct imsic_global_config *global = &imsic->global;
> > +
> > +     raw_spin_lock_init(&imsic->ids_lock);
> > +
> > +     /* Allocate used bitmap */
> > +     imsic->ids_used_bimap = bitmap_zalloc(global->nr_ids + 1, GFP_KERNEL);
> > +     if (!imsic->ids_used_bimap)
> > +             return -ENOMEM;
> > +
> > +     /* Allocate enabled bitmap */
> > +     imsic->ids_enabled_bimap = bitmap_zalloc(global->nr_ids + 1,
> > +                                             GFP_KERNEL);
> > +     if (!imsic->ids_enabled_bimap) {
> > +             kfree(imsic->ids_used_bimap);
> > +             return -ENOMEM;
> > +     }
> > +
> > +     /* Allocate target CPU array */
> > +     imsic->ids_target_cpu = kcalloc(global->nr_ids + 1,
> > +                                    sizeof(unsigned int), GFP_KERNEL);
> > +     if (!imsic->ids_target_cpu) {
> > +             bitmap_free(imsic->ids_enabled_bimap);
> > +             bitmap_free(imsic->ids_used_bimap);
> > +             return -ENOMEM;
> > +     }
> > +     for (i = 0; i <= global->nr_ids; i++)
> > +             imsic->ids_target_cpu[i] = UINT_MAX;
> > +
> > +     /* Reserve ID#0 because it is special and never implemented */
> > +     bitmap_set(imsic->ids_used_bimap, 0, 1);
> > +
> > +     return 0;
> > +}
> > +
> > +static void __init imsic_ids_cleanup(void)
> > +{
> > +     kfree(imsic->ids_target_cpu);
> > +     bitmap_free(imsic->ids_enabled_bimap);
> > +     bitmap_free(imsic->ids_used_bimap);
> > +}
> > +
> > +static int __init imsic_get_parent_hartid(struct fwnode_handle *fwnode,
> > +                                       u32 index, unsigned long *hartid)
> > +{
> > +     int rc;
> > +     struct fwnode_reference_args parent;
> > +
> > +     rc = fwnode_property_get_reference_args(fwnode,
> > +                     "interrupts-extended", "#interrupt-cells",
> > +                     0, index, &parent);
> > +     if (rc)
> > +             return rc;
> > +
> > +     /*
> > +      * Skip interrupts other than external interrupts for
> > +      * current privilege level.
> > +      */
> > +     if (parent.args[0] != RV_IRQ_EXT)
> > +             return -EINVAL;
> > +
> > +     return riscv_get_intc_hartid(parent.fwnode, hartid);
> > +}
> > +
> > +static int __init imsic_get_mmio_resource(struct fwnode_handle *fwnode,
> > +                                       u32 index, struct resource *res)
> > +{
> > +     /*
> > +      * Currently, only OF fwnode is support so extend this function
> > +      * for other types of fwnode for ACPI support.
> > +      */
> > +     if (!is_of_node(fwnode))
> > +             return -EINVAL;
> > +     return of_address_to_resource(to_of_node(fwnode), index, res);
> > +}
> > +
> > +int __init imsic_setup_state(struct fwnode_handle *fwnode)
> > +{
> > +     int rc, cpu;
> > +     phys_addr_t base_addr;
> > +     void __iomem **mmios_va = NULL;
> > +     struct resource res, *mmios = NULL;
> > +     struct imsic_local_config *local;
> > +     struct imsic_global_config *global;
> > +     unsigned long reloff, hartid;
> > +     u32 i, j, index, nr_parent_irqs, nr_handlers = 0, num_mmios = 0;
> > +
> > +     /*
> > +      * Only one IMSIC instance allowed in a platform for clean
> > +      * implementation of SMP IRQ affinity and per-CPU IPIs.
> > +      *
> > +      * This means on a multi-socket (or multi-die) platform we
> > +      * will have multiple MMIO regions for one IMSIC instance.
> > +      */
> > +     if (imsic) {
> > +             pr_err("%pfwP: already initialized hence ignoring\n",
> > +                     fwnode);
> > +             return -EALREADY;
> > +     }
> > +
> > +     if (!riscv_isa_extension_available(NULL, SxAIA)) {
> > +             pr_err("%pfwP: AIA support not available\n", fwnode);
> > +             return -ENODEV;
> > +     }
> > +
> > +     imsic = kzalloc(sizeof(*imsic), GFP_KERNEL);
> > +     if (!imsic)
> > +             return -ENOMEM;
> > +     imsic->fwnode = fwnode;
> > +     global = &imsic->global;
> > +
> > +     global->local = alloc_percpu(typeof(*(global->local)));
> > +     if (!global->local) {
> > +             rc = -ENOMEM;
> > +             goto out_free_priv;
> > +     }
> > +
> > +     /* Find number of parent interrupts */
> > +     nr_parent_irqs = 0;
> > +     while (!imsic_get_parent_hartid(fwnode, nr_parent_irqs, &hartid))
> > +             nr_parent_irqs++;
> > +     if (!nr_parent_irqs) {
> > +             pr_err("%pfwP: no parent irqs available\n", fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +
> > +     /* Find number of guest index bits in MSI address */
> > +     rc = fwnode_property_read_u32_array(fwnode, "riscv,guest-index-bits",
> > +                                         &global->guest_index_bits, 1);
> > +     if (rc)
> > +             global->guest_index_bits = 0;
> > +     i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT;
> > +     if (i < global->guest_index_bits) {
> > +             pr_err("%pfwP: guest index bits too big\n", fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +
> > +     /* Find number of HART index bits */
> > +     rc = fwnode_property_read_u32_array(fwnode, "riscv,hart-index-bits",
> > +                                         &global->hart_index_bits, 1);
> > +     if (rc) {
> > +             /* Assume default value */
> > +             global->hart_index_bits = __fls(nr_parent_irqs);
> > +             if (BIT(global->hart_index_bits) < nr_parent_irqs)
> > +                     global->hart_index_bits++;
> > +     }
> > +     i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT - global->guest_index_bits;
> > +     if (i < global->hart_index_bits) {
> > +             pr_err("%pfwP: HART index bits too big\n", fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +
> > +     /* Find number of group index bits */
> > +     rc = fwnode_property_read_u32_array(fwnode, "riscv,group-index-bits",
> > +                                         &global->group_index_bits, 1);
> > +     if (rc)
> > +             global->group_index_bits = 0;
> > +     i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT -
> > +         global->guest_index_bits - global->hart_index_bits;
> > +     if (i < global->group_index_bits) {
> > +             pr_err("%pfwP: group index bits too big\n", fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +
> > +     /*
> > +      * Find first bit position of group index.
> > +      * If not specified assumed the default APLIC-IMSIC configuration.
> > +      */
> > +     rc = fwnode_property_read_u32_array(fwnode, "riscv,group-index-shift",
> > +                                         &global->group_index_shift, 1);
> > +     if (rc)
> > +             global->group_index_shift = IMSIC_MMIO_PAGE_SHIFT * 2;
> > +     i = global->group_index_bits + global->group_index_shift - 1;
> > +     if (i >= BITS_PER_LONG) {
> > +             pr_err("%pfwP: group index shift too big\n", fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +
> > +     /* Find number of interrupt identities */
> > +     rc = fwnode_property_read_u32_array(fwnode, "riscv,num-ids",
> > +                                         &global->nr_ids, 1);
> > +     if (rc) {
> > +             pr_err("%pfwP: number of interrupt identities not found\n",
> > +                     fwnode);
> > +             goto out_free_local;
> > +     }
> > +     if ((global->nr_ids < IMSIC_MIN_ID) ||
> > +         (global->nr_ids >= IMSIC_MAX_ID) ||
> > +         ((global->nr_ids & IMSIC_MIN_ID) != IMSIC_MIN_ID)) {
> > +             pr_err("%pfwP: invalid number of interrupt identities\n",
> > +                     fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +
> > +     /* Find number of guest interrupt identities */
> > +     if (fwnode_property_read_u32_array(fwnode, "riscv,num-guest-ids",
> > +                                        &global->nr_guest_ids, 1))
> > +             global->nr_guest_ids = global->nr_ids;
> > +     if ((global->nr_guest_ids < IMSIC_MIN_ID) ||
> > +         (global->nr_guest_ids >= IMSIC_MAX_ID) ||
> > +         ((global->nr_guest_ids & IMSIC_MIN_ID) != IMSIC_MIN_ID)) {
> > +             pr_err("%pfwP: invalid number of guest interrupt identities\n",
> > +                     fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +
>
> Could you create a separate function for DT to fill up this
> imsic_global structure? In case of ACPI, we can not get this data from
> the fwnode and hence need to have separate function to fill up this
> structure.

Okay, I will update.

Regards,
Anup

>
> Thanks!
> Sunil
> > +     /* Compute base address */
> > +     rc = imsic_get_mmio_resource(fwnode, 0, &res);
> > +     if (rc) {
> > +             pr_err("%pfwP: first MMIO resource not found\n", fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +     global->base_addr = res.start;
> > +     global->base_addr &= ~(BIT(global->guest_index_bits +
> > +                                global->hart_index_bits +
> > +                                IMSIC_MMIO_PAGE_SHIFT) - 1);
> > +     global->base_addr &= ~((BIT(global->group_index_bits) - 1) <<
> > +                            global->group_index_shift);
> > +
> > +     /* Find number of MMIO register sets */
> > +     while (!imsic_get_mmio_resource(fwnode, num_mmios, &res))
> > +             num_mmios++;
> > +
> > +     /* Allocate MMIO resource array */
> > +     mmios = kcalloc(num_mmios, sizeof(*mmios), GFP_KERNEL);
> > +     if (!mmios) {
> > +             rc = -ENOMEM;
> > +             goto out_free_local;
> > +     }
> > +
> > +     /* Allocate MMIO virtual address array */
> > +     mmios_va = kcalloc(num_mmios, sizeof(*mmios_va), GFP_KERNEL);
> > +     if (!mmios_va) {
> > +             rc = -ENOMEM;
> > +             goto out_iounmap;
> > +     }
> > +
> > +     /* Parse and map MMIO register sets */
> > +     for (i = 0; i < num_mmios; i++) {
> > +             rc = imsic_get_mmio_resource(fwnode, i, &mmios[i]);
> > +             if (rc) {
> > +                     pr_err("%pfwP: unable to parse MMIO regset %d\n",
> > +                             fwnode, i);
> > +                     goto out_iounmap;
> > +             }
> > +
> > +             base_addr = mmios[i].start;
> > +             base_addr &= ~(BIT(global->guest_index_bits +
> > +                                global->hart_index_bits +
> > +                                IMSIC_MMIO_PAGE_SHIFT) - 1);
> > +             base_addr &= ~((BIT(global->group_index_bits) - 1) <<
> > +                            global->group_index_shift);
> > +             if (base_addr != global->base_addr) {
> > +                     rc = -EINVAL;
> > +                     pr_err("%pfwP: address mismatch for regset %d\n",
> > +                             fwnode, i);
> > +                     goto out_iounmap;
> > +             }
> > +
> > +             mmios_va[i] = ioremap(mmios[i].start, resource_size(&mmios[i]));
> > +             if (!mmios_va[i]) {
> > +                     rc = -EIO;
> > +                     pr_err("%pfwP: unable to map MMIO regset %d\n",
> > +                             fwnode, i);
> > +                     goto out_iounmap;
> > +             }
> > +     }
> > +
> > +     /* Initialize interrupt identity management */
> > +     rc = imsic_ids_init();
> > +     if (rc) {
> > +             pr_err("%pfwP: failed to initialize interrupt management\n",
> > +                    fwnode);
> > +             goto out_iounmap;
> > +     }
> > +
> > +     /* Configure handlers for target CPUs */
> > +     for (i = 0; i < nr_parent_irqs; i++) {
> > +             rc = imsic_get_parent_hartid(fwnode, i, &hartid);
> > +             if (rc) {
> > +                     pr_warn("%pfwP: hart ID for parent irq%d not found\n",
> > +                             fwnode, i);
> > +                     continue;
> > +             }
> > +
> > +             cpu = riscv_hartid_to_cpuid(hartid);
> > +             if (cpu < 0) {
> > +                     pr_warn("%pfwP: invalid cpuid for parent irq%d\n",
> > +                             fwnode, i);
> > +                     continue;
> > +             }
> > +
> > +             /* Find MMIO location of MSI page */
> > +             index = num_mmios;
> > +             reloff = i * BIT(global->guest_index_bits) *
> > +                      IMSIC_MMIO_PAGE_SZ;
> > +             for (j = 0; num_mmios; j++) {
> > +                     if (reloff < resource_size(&mmios[j])) {
> > +                             index = j;
> > +                             break;
> > +                     }
> > +
> > +                     /*
> > +                      * MMIO region size may not be aligned to
> > +                      * BIT(global->guest_index_bits) * IMSIC_MMIO_PAGE_SZ
> > +                      * if holes are present.
> > +                      */
> > +                     reloff -= ALIGN(resource_size(&mmios[j]),
> > +                     BIT(global->guest_index_bits) * IMSIC_MMIO_PAGE_SZ);
> > +             }
> > +             if (index >= num_mmios) {
> > +                     pr_warn("%pfwP: MMIO not found for parent irq%d\n",
> > +                             fwnode, i);
> > +                     continue;
> > +             }
> > +
> > +             local = per_cpu_ptr(global->local, cpu);
> > +             local->msi_pa = mmios[index].start + reloff;
> > +             local->msi_va = mmios_va[index] + reloff;
> > +
> > +             nr_handlers++;
> > +     }
> > +
> > +     /* If no CPU handlers found then can't take interrupts */
> > +     if (!nr_handlers) {
> > +             pr_err("%pfwP: No CPU handlers found\n", fwnode);
> > +             rc = -ENODEV;
> > +             goto out_ids_cleanup;
> > +     }
> > +
> > +     /* We don't need MMIO arrays anymore so let's free-up */
> > +     kfree(mmios_va);
> > +     kfree(mmios);
> > +
> > +     return 0;
> > +
> > +out_ids_cleanup:
> > +     imsic_ids_cleanup();
> > +out_iounmap:
> > +     for (i = 0; i < num_mmios; i++) {
> > +             if (mmios_va[i])
> > +                     iounmap(mmios_va[i]);
> > +     }
> > +     kfree(mmios_va);
> > +     kfree(mmios);
> > +out_free_local:
> > +     free_percpu(imsic->global.local);
> > +out_free_priv:
> > +     kfree(imsic);
> > +     imsic = NULL;
> > +     return rc;
> > +}
> > diff --git a/drivers/irqchip/irq-riscv-imsic-state.h b/drivers/irqchip/irq-riscv-imsic-state.h
> > new file mode 100644
> > index 000000000000..3170018949a8
> > --- /dev/null
> > +++ b/drivers/irqchip/irq-riscv-imsic-state.h
> > @@ -0,0 +1,66 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only */
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +
> > +#ifndef _IRQ_RISCV_IMSIC_STATE_H
> > +#define _IRQ_RISCV_IMSIC_STATE_H
> > +
> > +#include <linux/irqchip/riscv-imsic.h>
> > +#include <linux/irqdomain.h>
> > +#include <linux/fwnode.h>
> > +
> > +struct imsic_priv {
> > +     /* Device details */
> > +     struct fwnode_handle *fwnode;
> > +
> > +     /* Global configuration common for all HARTs */
> > +     struct imsic_global_config global;
> > +
> > +     /* Global state of interrupt identities */
> > +     raw_spinlock_t ids_lock;
> > +     unsigned long *ids_used_bimap;
> > +     unsigned long *ids_enabled_bimap;
> > +     unsigned int *ids_target_cpu;
> > +
> > +     /* IPI interrupt identity and synchronization */
> > +     u32 ipi_id;
> > +     int ipi_virq;
> > +     struct irq_desc *ipi_lsync_desc;
> > +
> > +     /* IRQ domains (created by platform driver) */
> > +     struct irq_domain *base_domain;
> > +     struct irq_domain *plat_domain;
> > +};
> > +
> > +extern struct imsic_priv *imsic;
> > +
> > +void __imsic_eix_update(unsigned long base_id,
> > +                     unsigned long num_id, bool pend, bool val);
> > +
> > +#define __imsic_id_enable(__id)              \
> > +     __imsic_eix_update((__id), 1, false, true)
> > +#define __imsic_id_disable(__id)     \
> > +     __imsic_eix_update((__id), 1, false, false)
> > +
> > +void imsic_id_set_target(unsigned int id, unsigned int target_cpu);
> > +unsigned int imsic_id_get_target(unsigned int id);
> > +
> > +void imsic_ids_local_sync(void);
> > +void imsic_ids_local_delivery(bool enable);
> > +
> > +#ifdef CONFIG_SMP
> > +void imsic_ids_remote_sync(void);
> > +#else
> > +static inline void imsic_ids_remote_sync(void)
> > +{
> > +}
> > +#endif
> > +
> > +int imsic_ids_alloc(unsigned int order);
> > +void imsic_ids_free(unsigned int base_id, unsigned int order);
> > +
> > +int imsic_setup_state(struct fwnode_handle *fwnode);
> > +
> > +#endif
> > diff --git a/include/linux/irqchip/riscv-imsic.h b/include/linux/irqchip/riscv-imsic.h
> > new file mode 100644
> > index 000000000000..1f6fc9a57218
> > --- /dev/null
> > +++ b/include/linux/irqchip/riscv-imsic.h
> > @@ -0,0 +1,86 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only */
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +#ifndef __LINUX_IRQCHIP_RISCV_IMSIC_H
> > +#define __LINUX_IRQCHIP_RISCV_IMSIC_H
> > +
> > +#include <linux/types.h>
> > +#include <asm/csr.h>
> > +
> > +#define IMSIC_MMIO_PAGE_SHIFT                12
> > +#define IMSIC_MMIO_PAGE_SZ           (1UL << IMSIC_MMIO_PAGE_SHIFT)
> > +#define IMSIC_MMIO_PAGE_LE           0x00
> > +#define IMSIC_MMIO_PAGE_BE           0x04
> > +
> > +#define IMSIC_MIN_ID                 63
> > +#define IMSIC_MAX_ID                 2048
> > +
> > +#define IMSIC_EIDELIVERY             0x70
> > +
> > +#define IMSIC_EITHRESHOLD            0x72
> > +
> > +#define IMSIC_EIP0                   0x80
> > +#define IMSIC_EIP63                  0xbf
> > +#define IMSIC_EIPx_BITS                      32
> > +
> > +#define IMSIC_EIE0                   0xc0
> > +#define IMSIC_EIE63                  0xff
> > +#define IMSIC_EIEx_BITS                      32
> > +
> > +#define IMSIC_FIRST                  IMSIC_EIDELIVERY
> > +#define IMSIC_LAST                   IMSIC_EIE63
> > +
> > +#define IMSIC_MMIO_SETIPNUM_LE               0x00
> > +#define IMSIC_MMIO_SETIPNUM_BE               0x04
> > +
> > +struct imsic_local_config {
> > +     phys_addr_t msi_pa;
> > +     void __iomem *msi_va;
> > +};
> > +
> > +struct imsic_global_config {
> > +     /*
> > +      * MSI Target Address Scheme
> > +      *
> > +      * XLEN-1                                                12     0
> > +      * |                                                     |     |
> > +      * -------------------------------------------------------------
> > +      * |xxxxxx|Group Index|xxxxxxxxxxx|HART Index|Guest Index|  0  |
> > +      * -------------------------------------------------------------
> > +      */
> > +
> > +     /* Bits representing Guest index, HART index, and Group index */
> > +     u32 guest_index_bits;
> > +     u32 hart_index_bits;
> > +     u32 group_index_bits;
> > +     u32 group_index_shift;
> > +
> > +     /* Global base address matching all target MSI addresses */
> > +     phys_addr_t base_addr;
> > +
> > +     /* Number of interrupt identities */
> > +     u32 nr_ids;
> > +
> > +     /* Number of guest interrupt identities */
> > +     u32 nr_guest_ids;
> > +
> > +     /* Per-CPU IMSIC addresses */
> > +     struct imsic_local_config __percpu *local;
> > +};
> > +
> > +#ifdef CONFIG_RISCV_IMSIC
> > +
> > +extern const struct imsic_global_config *imsic_get_global_config(void);
> > +
> > +#else
> > +
> > +static inline const struct imsic_global_config *imsic_get_global_config(void)
> > +{
> > +     return NULL;
> > +}
> > +
> > +#endif
> > +
> > +#endif
> > --
> > 2.34.1
> >

Re: [PATCH v8 09/16] irqchip: Add RISC-V incoming MSI controller early driver

[Anup Patel]

On Mon, Sep 25, 2023 at 1:19 PM Sunil V L <sunilvl@ventanamicro.com> wrote:
>
> Hi Anup,
>
> On Tue, Sep 12, 2023 at 11:19:21PM +0530, Anup Patel wrote:
> > The RISC-V advanced interrupt architecture (AIA) specification
> > defines a new MSI controller called incoming message signalled
> > interrupt controller (IMSIC) which manages MSI on per-HART (or
> > per-CPU) basis. It also supports IPIs as software injected MSIs.
> > (For more details refer https://github.com/riscv/riscv-aia)
> >
> > Let us add an early irqchip driver for RISC-V IMSIC which sets
> > up the IMSIC state and provide IPIs.
> >
> > Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> > ---
> >  drivers/irqchip/Kconfig                 |   7 +-
> >  drivers/irqchip/Makefile                |   1 +
> >  drivers/irqchip/irq-riscv-imsic-early.c | 258 ++++++++++++
> >  drivers/irqchip/irq-riscv-imsic-state.c | 523 ++++++++++++++++++++++++
> >  drivers/irqchip/irq-riscv-imsic-state.h |  66 +++
> >  include/linux/irqchip/riscv-imsic.h     |  86 ++++
> >  6 files changed, 940 insertions(+), 1 deletion(-)
> >  create mode 100644 drivers/irqchip/irq-riscv-imsic-early.c
> >  create mode 100644 drivers/irqchip/irq-riscv-imsic-state.c
> >  create mode 100644 drivers/irqchip/irq-riscv-imsic-state.h
> >  create mode 100644 include/linux/irqchip/riscv-imsic.h
> >
> > diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> > index f7149d0f3d45..ee99aacbefcc 100644
> > --- a/drivers/irqchip/Kconfig
> > +++ b/drivers/irqchip/Kconfig
> > @@ -30,7 +30,6 @@ config ARM_GIC_V2M
> >
> >  config GIC_NON_BANKED
> >       bool
> > -
> >  config ARM_GIC_V3
> >       bool
> >       select IRQ_DOMAIN_HIERARCHY
> > @@ -546,6 +545,12 @@ config SIFIVE_PLIC
> >       select IRQ_DOMAIN_HIERARCHY
> >       select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
> >
> > +config RISCV_IMSIC
> > +     bool
> > +     depends on RISCV
> > +     select IRQ_DOMAIN_HIERARCHY
> > +     select GENERIC_MSI_IRQ
> > +
> >  config EXYNOS_IRQ_COMBINER
> >       bool "Samsung Exynos IRQ combiner support" if COMPILE_TEST
> >       depends on (ARCH_EXYNOS && ARM) || COMPILE_TEST
> > diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> > index ffd945fe71aa..d714724387ce 100644
> > --- a/drivers/irqchip/Makefile
> > +++ b/drivers/irqchip/Makefile
> > @@ -95,6 +95,7 @@ obj-$(CONFIG_QCOM_MPM)                      += irq-qcom-mpm.o
> >  obj-$(CONFIG_CSKY_MPINTC)            += irq-csky-mpintc.o
> >  obj-$(CONFIG_CSKY_APB_INTC)          += irq-csky-apb-intc.o
> >  obj-$(CONFIG_RISCV_INTC)             += irq-riscv-intc.o
> > +obj-$(CONFIG_RISCV_IMSIC)            += irq-riscv-imsic-state.o irq-riscv-imsic-early.o
> >  obj-$(CONFIG_SIFIVE_PLIC)            += irq-sifive-plic.o
> >  obj-$(CONFIG_IMX_IRQSTEER)           += irq-imx-irqsteer.o
> >  obj-$(CONFIG_IMX_INTMUX)             += irq-imx-intmux.o
> > diff --git a/drivers/irqchip/irq-riscv-imsic-early.c b/drivers/irqchip/irq-riscv-imsic-early.c
> > new file mode 100644
> > index 000000000000..1de89ce1ec2f
> > --- /dev/null
> > +++ b/drivers/irqchip/irq-riscv-imsic-early.c
> > @@ -0,0 +1,258 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +
> > +#define pr_fmt(fmt) "riscv-imsic: " fmt
> > +#include <linux/cpu.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/io.h>
> > +#include <linux/irq.h>
> > +#include <linux/irqchip.h>
> > +#include <linux/irqchip/chained_irq.h>
> > +#include <linux/module.h>
> > +#include <linux/spinlock.h>
> > +#include <linux/smp.h>
> > +
> > +#include "irq-riscv-imsic-state.h"
> > +
> > +/*
> > + * The IMSIC driver uses 1 IPI for ID synchronization and
> > + * arch/riscv/kernel/smp.c require 6 IPIs so we fix the
> > + * total number of IPIs to 8.
> > + */
> > +#define IMSIC_NR_IPI                         8
> > +
> > +static int imsic_parent_irq;
> > +
> > +#ifdef CONFIG_SMP
> > +static irqreturn_t imsic_ids_sync_handler(int irq, void *data)
> > +{
> > +     imsic_ids_local_sync();
> > +     return IRQ_HANDLED;
> > +}
> > +
> > +void imsic_ids_remote_sync(void)
> > +{
> > +     struct cpumask amask;
> > +
> > +     /*
> > +      * We simply inject ID synchronization IPI to all target CPUs
> > +      * except current CPU. The ipi_send_mask() implementation of
> > +      * IPI mux will inject ID synchronization IPI only for CPUs
> > +      * that have enabled it so offline CPUs won't receive IPI.
> > +      * An offline CPU will unconditionally synchronize IDs through
> > +      * imsic_starting_cpu() when the CPU is brought up.
> > +      */
> > +     cpumask_andnot(&amask, cpu_online_mask, cpumask_of(smp_processor_id()));
> > +     __ipi_send_mask(imsic->ipi_lsync_desc, &amask);
> > +}
> > +
> > +static void imsic_ipi_send(unsigned int cpu)
> > +{
> > +     struct imsic_local_config *local =
> > +                             per_cpu_ptr(imsic->global.local, cpu);
> > +
> > +     writel(imsic->ipi_id, local->msi_va);
> > +}
> > +
> > +static void imsic_ipi_starting_cpu(void)
> > +{
> > +     /* Enable IPIs for current CPU. */
> > +     __imsic_id_enable(imsic->ipi_id);
> > +
> > +     /* Enable virtual IPI used for IMSIC ID synchronization */
> > +     enable_percpu_irq(imsic->ipi_virq, 0);
> > +}
> > +
> > +static void imsic_ipi_dying_cpu(void)
> > +{
> > +     /*
> > +      * Disable virtual IPI used for IMSIC ID synchronization so
> > +      * that we don't receive ID synchronization requests.
> > +      */
> > +     disable_percpu_irq(imsic->ipi_virq);
> > +}
> > +
> > +static int __init imsic_ipi_domain_init(void)
> > +{
> > +     int virq;
> > +
> > +     /* Allocate interrupt identity for IPIs */
> > +     virq = imsic_ids_alloc(get_count_order(1));
> > +     if (virq < 0)
> > +             return virq;
> > +     imsic->ipi_id = virq;
> > +
> > +     /* Create IMSIC IPI multiplexing */
> > +     virq = ipi_mux_create(IMSIC_NR_IPI, imsic_ipi_send);
> > +     if (virq <= 0) {
> > +             imsic_ids_free(imsic->ipi_id, get_count_order(1));
> > +             return (virq < 0) ? virq : -ENOMEM;
> > +     }
> > +     imsic->ipi_virq = virq;
> > +
> > +     /* First vIRQ is used for IMSIC ID synchronization */
> > +     virq = request_percpu_irq(imsic->ipi_virq, imsic_ids_sync_handler,
> > +                               "riscv-imsic-lsync", imsic->global.local);
> > +     if (virq) {
> > +             imsic_ids_free(imsic->ipi_id, get_count_order(1));
> > +             return virq;
> > +     }
> > +     irq_set_status_flags(imsic->ipi_virq, IRQ_HIDDEN);
> > +     imsic->ipi_lsync_desc = irq_to_desc(imsic->ipi_virq);
> > +
> > +     /* Set vIRQ range */
> > +     riscv_ipi_set_virq_range(imsic->ipi_virq + 1, IMSIC_NR_IPI - 1, true);
> > +
> > +     /* Announce that IMSIC is providing IPIs */
> > +     pr_info("%pfwP: providing IPIs using interrupt %d\n",
> > +             imsic->fwnode, imsic->ipi_id);
> > +
> > +     return 0;
> > +}
> > +#else
> > +static void imsic_ipi_starting_cpu(void)
> > +{
> > +}
> > +
> > +static void imsic_ipi_dying_cpu(void)
> > +{
> > +}
> > +
> > +static int __init imsic_ipi_domain_init(void)
> > +{
> > +     /* Clear the IPI id because we are not using IPIs */
> > +     imsic->ipi_id = 0;
> > +     return 0;
> > +}
> > +#endif
> > +
> > +/*
> > + * To handle an interrupt, we read the TOPEI CSR and write zero in one
> > + * instruction. If TOPEI CSR is non-zero then we translate TOPEI.ID to
> > + * Linux interrupt number and let Linux IRQ subsystem handle it.
> > + */
> > +static void imsic_handle_irq(struct irq_desc *desc)
> > +{
> > +     struct irq_chip *chip = irq_desc_get_chip(desc);
> > +     irq_hw_number_t hwirq;
> > +     int err;
> > +
> > +     chained_irq_enter(chip, desc);
> > +
> > +     while ((hwirq = csr_swap(CSR_TOPEI, 0))) {
> > +             hwirq = hwirq >> TOPEI_ID_SHIFT;
> > +
> > +             if (hwirq == imsic->ipi_id) {
> > +#ifdef CONFIG_SMP
> > +                     ipi_mux_process();
> > +#endif
> > +                     continue;
> > +             }
> > +
> > +             if (unlikely(!imsic->base_domain))
> > +                     continue;
> > +
> > +             err = generic_handle_domain_irq(imsic->base_domain, hwirq);
> > +             if (unlikely(err))
> > +                     pr_warn_ratelimited(
> > +                             "hwirq %lu mapping not found\n", hwirq);
> > +     }
> > +
> > +     chained_irq_exit(chip, desc);
> > +}
> > +
> > +static int imsic_starting_cpu(unsigned int cpu)
> > +{
> > +     /* Enable per-CPU parent interrupt */
> > +     enable_percpu_irq(imsic_parent_irq,
> > +                       irq_get_trigger_type(imsic_parent_irq));
> > +
> > +     /* Setup IPIs */
> > +     imsic_ipi_starting_cpu();
> > +
> > +     /*
> > +      * Interrupts identities might have been enabled/disabled while
> > +      * this CPU was not running so sync-up local enable/disable state.
> > +      */
> > +     imsic_ids_local_sync();
> > +
> > +     /* Enable local interrupt delivery */
> > +     imsic_ids_local_delivery(true);
> > +
> > +     return 0;
> > +}
> > +
> > +static int imsic_dying_cpu(unsigned int cpu)
> > +{
> > +     /* Cleanup IPIs */
> > +     imsic_ipi_dying_cpu();
> > +
> > +     return 0;
> > +}
> > +
> > +static int __init imsic_early_probe(struct fwnode_handle *fwnode)
>
> Can this imsic_early_probe() take an additional pointer as parameter?
> This parameter can be NULL for DT and we can use to pass the MADT
> structure in case of ACPI since fwnode in ACPI will not have any
> properties. The parameter needs to be passed to imsic_setup_state()
> also.

Instead, I am thinking of moving the imsic_setup_state() call to
imsic_early_dt_init() so that we can directly pass extra parameters
from imsic_early_dt_init().

>
> > +{
> > +     int rc;
> > +     struct irq_domain *domain;
> > +
> > +     /* Setup IMSIC state */
> > +     rc = imsic_setup_state(fwnode);
> > +     if (rc) {
> > +             pr_err("%pfwP: failed to setup state (error %d)\n",
> > +                     fwnode, rc);
> > +             return rc;
> > +     }
> > +
> > +     /* Find parent domain and register chained handler */
> > +     domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
> > +                                       DOMAIN_BUS_ANY);
> > +     if (!domain) {
> > +             pr_err("%pfwP: Failed to find INTC domain\n", fwnode);
> > +             return -ENOENT;
> > +     }
> > +     imsic_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT);
> > +     if (!imsic_parent_irq) {
> > +             pr_err("%pfwP: Failed to create INTC mapping\n", fwnode);
> > +             return -ENOENT;
> > +     }
> > +     irq_set_chained_handler(imsic_parent_irq, imsic_handle_irq);
> > +
> > +     /* Initialize IPI domain */
> > +     rc = imsic_ipi_domain_init();
> > +     if (rc) {
> > +             pr_err("%pfwP: Failed to initialize IPI domain\n", fwnode);
> > +             return rc;
> > +     }
> > +
> > +     /*
> > +      * Setup cpuhp state (must be done after setting imsic_parent_irq)
> > +      *
> > +      * Don't disable per-CPU IMSIC file when CPU goes offline
> > +      * because this affects IPI and the masking/unmasking of
> > +      * virtual IPIs is done via generic IPI-Mux
> > +      */
> > +     cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
> > +                       "irqchip/riscv/imsic:starting",
> > +                       imsic_starting_cpu, imsic_dying_cpu);
> > +
> > +     return 0;
> > +}
> > +
> > +static int __init imsic_early_dt_init(struct device_node *node,
> > +                                   struct device_node *parent)
> > +{
> > +     int rc;
> > +
> > +     /* Do early setup of IMSIC state and IPIs */
> > +     rc = imsic_early_probe(&node->fwnode);
> > +     if (rc)
> > +             return rc;
> > +
> > +     /* Ensure that OF platform device gets probed */
> > +     of_node_clear_flag(node, OF_POPULATED);
> > +     return 0;
> > +}
> > +IRQCHIP_DECLARE(riscv_imsic, "riscv,imsics", imsic_early_dt_init);
> > diff --git a/drivers/irqchip/irq-riscv-imsic-state.c b/drivers/irqchip/irq-riscv-imsic-state.c
> > new file mode 100644
> > index 000000000000..412b5b919dcc
> > --- /dev/null
> > +++ b/drivers/irqchip/irq-riscv-imsic-state.c
> > @@ -0,0 +1,523 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +
> > +#define pr_fmt(fmt) "riscv-imsic: " fmt
> > +#include <linux/bitmap.h>
> > +#include <linux/module.h>
> > +#include <linux/of_address.h>
> > +#include <linux/spinlock.h>
> > +#include <linux/smp.h>
> > +#include <asm/hwcap.h>
> > +
> > +#include "irq-riscv-imsic-state.h"
> > +
> > +#define IMSIC_DISABLE_EIDELIVERY             0
> > +#define IMSIC_ENABLE_EIDELIVERY                      1
> > +#define IMSIC_DISABLE_EITHRESHOLD            1
> > +#define IMSIC_ENABLE_EITHRESHOLD             0
> > +
> > +#define imsic_csr_write(__c, __v)            \
> > +do {                                         \
> > +     csr_write(CSR_ISELECT, __c);            \
> > +     csr_write(CSR_IREG, __v);               \
> > +} while (0)
> > +
> > +#define imsic_csr_read(__c)                  \
> > +({                                           \
> > +     unsigned long __v;                      \
> > +     csr_write(CSR_ISELECT, __c);            \
> > +     __v = csr_read(CSR_IREG);               \
> > +     __v;                                    \
> > +})
> > +
> > +#define imsic_csr_set(__c, __v)                      \
> > +do {                                         \
> > +     csr_write(CSR_ISELECT, __c);            \
> > +     csr_set(CSR_IREG, __v);                 \
> > +} while (0)
> > +
> > +#define imsic_csr_clear(__c, __v)            \
> > +do {                                         \
> > +     csr_write(CSR_ISELECT, __c);            \
> > +     csr_clear(CSR_IREG, __v);               \
> > +} while (0)
> > +
> > +struct imsic_priv *imsic;
> > +
> > +const struct imsic_global_config *imsic_get_global_config(void)
> > +{
> > +     return (imsic) ? &imsic->global : NULL;
> > +}
> > +EXPORT_SYMBOL_GPL(imsic_get_global_config);
> > +
> > +void __imsic_eix_update(unsigned long base_id,
> > +                     unsigned long num_id, bool pend, bool val)
> > +{
> > +     unsigned long i, isel, ireg;
> > +     unsigned long id = base_id, last_id = base_id + num_id;
> > +
> > +     while (id < last_id) {
> > +             isel = id / BITS_PER_LONG;
> > +             isel *= BITS_PER_LONG / IMSIC_EIPx_BITS;
> > +             isel += (pend) ? IMSIC_EIP0 : IMSIC_EIE0;
> > +
> > +             ireg = 0;
> > +             for (i = id & (__riscv_xlen - 1);
> > +                  (id < last_id) && (i < __riscv_xlen); i++) {
> > +                     ireg |= BIT(i);
> > +                     id++;
> > +             }
> > +
> > +             /*
> > +              * The IMSIC EIEx and EIPx registers are indirectly
> > +              * accessed via using ISELECT and IREG CSRs so we
> > +              * need to access these CSRs without getting preempted.
> > +              *
> > +              * All existing users of this function call this
> > +              * function with local IRQs disabled so we don't
> > +              * need to do anything special here.
> > +              */
> > +             if (val)
> > +                     imsic_csr_set(isel, ireg);
> > +             else
> > +                     imsic_csr_clear(isel, ireg);
> > +     }
> > +}
> > +
> > +void imsic_id_set_target(unsigned int id, unsigned int target_cpu)
> > +{
> > +     unsigned long flags;
> > +
> > +     raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> > +     imsic->ids_target_cpu[id] = target_cpu;
> > +     raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> > +}
> > +
> > +unsigned int imsic_id_get_target(unsigned int id)
> > +{
> > +     unsigned int ret;
> > +     unsigned long flags;
> > +
> > +     raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> > +     ret = imsic->ids_target_cpu[id];
> > +     raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> > +
> > +     return ret;
> > +}
> > +
> > +void imsic_ids_local_sync(void)
> > +{
> > +     int i;
> > +     unsigned long flags;
> > +
> > +     raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> > +     for (i = 1; i <= imsic->global.nr_ids; i++) {
> > +             if (imsic->ipi_id == i)
> > +                     continue;
> > +
> > +             if (test_bit(i, imsic->ids_enabled_bimap))
> > +                     __imsic_id_enable(i);
> > +             else
> > +                     __imsic_id_disable(i);
> > +     }
> > +     raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> > +}
> > +
> > +void imsic_ids_local_delivery(bool enable)
> > +{
> > +     if (enable) {
> > +             imsic_csr_write(IMSIC_EITHRESHOLD, IMSIC_ENABLE_EITHRESHOLD);
> > +             imsic_csr_write(IMSIC_EIDELIVERY, IMSIC_ENABLE_EIDELIVERY);
> > +     } else {
> > +             imsic_csr_write(IMSIC_EIDELIVERY, IMSIC_DISABLE_EIDELIVERY);
> > +             imsic_csr_write(IMSIC_EITHRESHOLD, IMSIC_DISABLE_EITHRESHOLD);
> > +     }
> > +}
> > +
> > +int imsic_ids_alloc(unsigned int order)
> > +{
> > +     int ret;
> > +     unsigned long flags;
> > +
> > +     raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> > +     ret = bitmap_find_free_region(imsic->ids_used_bimap,
> > +                                   imsic->global.nr_ids + 1, order);
> > +     raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> > +
> > +     return ret;
> > +}
> > +
> > +void imsic_ids_free(unsigned int base_id, unsigned int order)
> > +{
> > +     unsigned long flags;
> > +
> > +     raw_spin_lock_irqsave(&imsic->ids_lock, flags);
> > +     bitmap_release_region(imsic->ids_used_bimap, base_id, order);
> > +     raw_spin_unlock_irqrestore(&imsic->ids_lock, flags);
> > +}
> > +
> > +static int __init imsic_ids_init(void)
> > +{
> > +     int i;
> > +     struct imsic_global_config *global = &imsic->global;
> > +
> > +     raw_spin_lock_init(&imsic->ids_lock);
> > +
> > +     /* Allocate used bitmap */
> > +     imsic->ids_used_bimap = bitmap_zalloc(global->nr_ids + 1, GFP_KERNEL);
> > +     if (!imsic->ids_used_bimap)
> > +             return -ENOMEM;
> > +
> > +     /* Allocate enabled bitmap */
> > +     imsic->ids_enabled_bimap = bitmap_zalloc(global->nr_ids + 1,
> > +                                             GFP_KERNEL);
> > +     if (!imsic->ids_enabled_bimap) {
> > +             kfree(imsic->ids_used_bimap);
> > +             return -ENOMEM;
> > +     }
> > +
> > +     /* Allocate target CPU array */
> > +     imsic->ids_target_cpu = kcalloc(global->nr_ids + 1,
> > +                                    sizeof(unsigned int), GFP_KERNEL);
> > +     if (!imsic->ids_target_cpu) {
> > +             bitmap_free(imsic->ids_enabled_bimap);
> > +             bitmap_free(imsic->ids_used_bimap);
> > +             return -ENOMEM;
> > +     }
> > +     for (i = 0; i <= global->nr_ids; i++)
> > +             imsic->ids_target_cpu[i] = UINT_MAX;
> > +
> > +     /* Reserve ID#0 because it is special and never implemented */
> > +     bitmap_set(imsic->ids_used_bimap, 0, 1);
> > +
> > +     return 0;
> > +}
> > +
> > +static void __init imsic_ids_cleanup(void)
> > +{
> > +     kfree(imsic->ids_target_cpu);
> > +     bitmap_free(imsic->ids_enabled_bimap);
> > +     bitmap_free(imsic->ids_used_bimap);
> > +}
> > +
> > +static int __init imsic_get_parent_hartid(struct fwnode_handle *fwnode,
> > +                                       u32 index, unsigned long *hartid)
> > +{
> > +     int rc;
> > +     struct fwnode_reference_args parent;
> > +
> > +     rc = fwnode_property_get_reference_args(fwnode,
> > +                     "interrupts-extended", "#interrupt-cells",
> > +                     0, index, &parent);
> > +     if (rc)
> > +             return rc;
> > +
> > +     /*
> > +      * Skip interrupts other than external interrupts for
> > +      * current privilege level.
> > +      */
> > +     if (parent.args[0] != RV_IRQ_EXT)
> > +             return -EINVAL;
> > +
> > +     return riscv_get_intc_hartid(parent.fwnode, hartid);
> > +}
> > +
> > +static int __init imsic_get_mmio_resource(struct fwnode_handle *fwnode,
> > +                                       u32 index, struct resource *res)
> > +{
> > +     /*
> > +      * Currently, only OF fwnode is support so extend this function
> > +      * for other types of fwnode for ACPI support.
> > +      */
> > +     if (!is_of_node(fwnode))
> > +             return -EINVAL;
> > +     return of_address_to_resource(to_of_node(fwnode), index, res);
> > +}
> > +
> > +int __init imsic_setup_state(struct fwnode_handle *fwnode)
> > +{
> > +     int rc, cpu;
> > +     phys_addr_t base_addr;
> > +     void __iomem **mmios_va = NULL;
> > +     struct resource res, *mmios = NULL;
> > +     struct imsic_local_config *local;
> > +     struct imsic_global_config *global;
> > +     unsigned long reloff, hartid;
> > +     u32 i, j, index, nr_parent_irqs, nr_handlers = 0, num_mmios = 0;
> > +
> > +     /*
> > +      * Only one IMSIC instance allowed in a platform for clean
> > +      * implementation of SMP IRQ affinity and per-CPU IPIs.
> > +      *
> > +      * This means on a multi-socket (or multi-die) platform we
> > +      * will have multiple MMIO regions for one IMSIC instance.
> > +      */
> > +     if (imsic) {
> > +             pr_err("%pfwP: already initialized hence ignoring\n",
> > +                     fwnode);
> > +             return -EALREADY;
> > +     }
> > +
> > +     if (!riscv_isa_extension_available(NULL, SxAIA)) {
> > +             pr_err("%pfwP: AIA support not available\n", fwnode);
> > +             return -ENODEV;
> > +     }
> > +
> > +     imsic = kzalloc(sizeof(*imsic), GFP_KERNEL);
> > +     if (!imsic)
> > +             return -ENOMEM;
> > +     imsic->fwnode = fwnode;
> > +     global = &imsic->global;
> > +
> > +     global->local = alloc_percpu(typeof(*(global->local)));
> > +     if (!global->local) {
> > +             rc = -ENOMEM;
> > +             goto out_free_priv;
> > +     }
> > +
> > +     /* Find number of parent interrupts */
> > +     nr_parent_irqs = 0;
> > +     while (!imsic_get_parent_hartid(fwnode, nr_parent_irqs, &hartid))
> > +             nr_parent_irqs++;
> > +     if (!nr_parent_irqs) {
> > +             pr_err("%pfwP: no parent irqs available\n", fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +
> > +     /* Find number of guest index bits in MSI address */
> > +     rc = fwnode_property_read_u32_array(fwnode, "riscv,guest-index-bits",
> > +                                         &global->guest_index_bits, 1);
> > +     if (rc)
> > +             global->guest_index_bits = 0;
> > +     i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT;
> > +     if (i < global->guest_index_bits) {
> > +             pr_err("%pfwP: guest index bits too big\n", fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +
> > +     /* Find number of HART index bits */
> > +     rc = fwnode_property_read_u32_array(fwnode, "riscv,hart-index-bits",
> > +                                         &global->hart_index_bits, 1);
> > +     if (rc) {
> > +             /* Assume default value */
> > +             global->hart_index_bits = __fls(nr_parent_irqs);
> > +             if (BIT(global->hart_index_bits) < nr_parent_irqs)
> > +                     global->hart_index_bits++;
> > +     }
> > +     i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT - global->guest_index_bits;
> > +     if (i < global->hart_index_bits) {
> > +             pr_err("%pfwP: HART index bits too big\n", fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +
> > +     /* Find number of group index bits */
> > +     rc = fwnode_property_read_u32_array(fwnode, "riscv,group-index-bits",
> > +                                         &global->group_index_bits, 1);
> > +     if (rc)
> > +             global->group_index_bits = 0;
> > +     i = BITS_PER_LONG - IMSIC_MMIO_PAGE_SHIFT -
> > +         global->guest_index_bits - global->hart_index_bits;
> > +     if (i < global->group_index_bits) {
> > +             pr_err("%pfwP: group index bits too big\n", fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +
> > +     /*
> > +      * Find first bit position of group index.
> > +      * If not specified assumed the default APLIC-IMSIC configuration.
> > +      */
> > +     rc = fwnode_property_read_u32_array(fwnode, "riscv,group-index-shift",
> > +                                         &global->group_index_shift, 1);
> > +     if (rc)
> > +             global->group_index_shift = IMSIC_MMIO_PAGE_SHIFT * 2;
> > +     i = global->group_index_bits + global->group_index_shift - 1;
> > +     if (i >= BITS_PER_LONG) {
> > +             pr_err("%pfwP: group index shift too big\n", fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +
> > +     /* Find number of interrupt identities */
> > +     rc = fwnode_property_read_u32_array(fwnode, "riscv,num-ids",
> > +                                         &global->nr_ids, 1);
> > +     if (rc) {
> > +             pr_err("%pfwP: number of interrupt identities not found\n",
> > +                     fwnode);
> > +             goto out_free_local;
> > +     }
> > +     if ((global->nr_ids < IMSIC_MIN_ID) ||
> > +         (global->nr_ids >= IMSIC_MAX_ID) ||
> > +         ((global->nr_ids & IMSIC_MIN_ID) != IMSIC_MIN_ID)) {
> > +             pr_err("%pfwP: invalid number of interrupt identities\n",
> > +                     fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +
> > +     /* Find number of guest interrupt identities */
> > +     if (fwnode_property_read_u32_array(fwnode, "riscv,num-guest-ids",
> > +                                        &global->nr_guest_ids, 1))
> > +             global->nr_guest_ids = global->nr_ids;
> > +     if ((global->nr_guest_ids < IMSIC_MIN_ID) ||
> > +         (global->nr_guest_ids >= IMSIC_MAX_ID) ||
> > +         ((global->nr_guest_ids & IMSIC_MIN_ID) != IMSIC_MIN_ID)) {
> > +             pr_err("%pfwP: invalid number of guest interrupt identities\n",
> > +                     fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +
>
> Could you create a separate function for DT to fill up this
> imsic_global structure? In case of ACPI, we can not get this data from
> the fwnode and hence need to have separate function to fill up this
> structure.

Okay, I will update.

Regards,
Anup

>
> Thanks!
> Sunil
> > +     /* Compute base address */
> > +     rc = imsic_get_mmio_resource(fwnode, 0, &res);
> > +     if (rc) {
> > +             pr_err("%pfwP: first MMIO resource not found\n", fwnode);
> > +             rc = -EINVAL;
> > +             goto out_free_local;
> > +     }
> > +     global->base_addr = res.start;
> > +     global->base_addr &= ~(BIT(global->guest_index_bits +
> > +                                global->hart_index_bits +
> > +                                IMSIC_MMIO_PAGE_SHIFT) - 1);
> > +     global->base_addr &= ~((BIT(global->group_index_bits) - 1) <<
> > +                            global->group_index_shift);
> > +
> > +     /* Find number of MMIO register sets */
> > +     while (!imsic_get_mmio_resource(fwnode, num_mmios, &res))
> > +             num_mmios++;
> > +
> > +     /* Allocate MMIO resource array */
> > +     mmios = kcalloc(num_mmios, sizeof(*mmios), GFP_KERNEL);
> > +     if (!mmios) {
> > +             rc = -ENOMEM;
> > +             goto out_free_local;
> > +     }
> > +
> > +     /* Allocate MMIO virtual address array */
> > +     mmios_va = kcalloc(num_mmios, sizeof(*mmios_va), GFP_KERNEL);
> > +     if (!mmios_va) {
> > +             rc = -ENOMEM;
> > +             goto out_iounmap;
> > +     }
> > +
> > +     /* Parse and map MMIO register sets */
> > +     for (i = 0; i < num_mmios; i++) {
> > +             rc = imsic_get_mmio_resource(fwnode, i, &mmios[i]);
> > +             if (rc) {
> > +                     pr_err("%pfwP: unable to parse MMIO regset %d\n",
> > +                             fwnode, i);
> > +                     goto out_iounmap;
> > +             }
> > +
> > +             base_addr = mmios[i].start;
> > +             base_addr &= ~(BIT(global->guest_index_bits +
> > +                                global->hart_index_bits +
> > +                                IMSIC_MMIO_PAGE_SHIFT) - 1);
> > +             base_addr &= ~((BIT(global->group_index_bits) - 1) <<
> > +                            global->group_index_shift);
> > +             if (base_addr != global->base_addr) {
> > +                     rc = -EINVAL;
> > +                     pr_err("%pfwP: address mismatch for regset %d\n",
> > +                             fwnode, i);
> > +                     goto out_iounmap;
> > +             }
> > +
> > +             mmios_va[i] = ioremap(mmios[i].start, resource_size(&mmios[i]));
> > +             if (!mmios_va[i]) {
> > +                     rc = -EIO;
> > +                     pr_err("%pfwP: unable to map MMIO regset %d\n",
> > +                             fwnode, i);
> > +                     goto out_iounmap;
> > +             }
> > +     }
> > +
> > +     /* Initialize interrupt identity management */
> > +     rc = imsic_ids_init();
> > +     if (rc) {
> > +             pr_err("%pfwP: failed to initialize interrupt management\n",
> > +                    fwnode);
> > +             goto out_iounmap;
> > +     }
> > +
> > +     /* Configure handlers for target CPUs */
> > +     for (i = 0; i < nr_parent_irqs; i++) {
> > +             rc = imsic_get_parent_hartid(fwnode, i, &hartid);
> > +             if (rc) {
> > +                     pr_warn("%pfwP: hart ID for parent irq%d not found\n",
> > +                             fwnode, i);
> > +                     continue;
> > +             }
> > +
> > +             cpu = riscv_hartid_to_cpuid(hartid);
> > +             if (cpu < 0) {
> > +                     pr_warn("%pfwP: invalid cpuid for parent irq%d\n",
> > +                             fwnode, i);
> > +                     continue;
> > +             }
> > +
> > +             /* Find MMIO location of MSI page */
> > +             index = num_mmios;
> > +             reloff = i * BIT(global->guest_index_bits) *
> > +                      IMSIC_MMIO_PAGE_SZ;
> > +             for (j = 0; num_mmios; j++) {
> > +                     if (reloff < resource_size(&mmios[j])) {
> > +                             index = j;
> > +                             break;
> > +                     }
> > +
> > +                     /*
> > +                      * MMIO region size may not be aligned to
> > +                      * BIT(global->guest_index_bits) * IMSIC_MMIO_PAGE_SZ
> > +                      * if holes are present.
> > +                      */
> > +                     reloff -= ALIGN(resource_size(&mmios[j]),
> > +                     BIT(global->guest_index_bits) * IMSIC_MMIO_PAGE_SZ);
> > +             }
> > +             if (index >= num_mmios) {
> > +                     pr_warn("%pfwP: MMIO not found for parent irq%d\n",
> > +                             fwnode, i);
> > +                     continue;
> > +             }
> > +
> > +             local = per_cpu_ptr(global->local, cpu);
> > +             local->msi_pa = mmios[index].start + reloff;
> > +             local->msi_va = mmios_va[index] + reloff;
> > +
> > +             nr_handlers++;
> > +     }
> > +
> > +     /* If no CPU handlers found then can't take interrupts */
> > +     if (!nr_handlers) {
> > +             pr_err("%pfwP: No CPU handlers found\n", fwnode);
> > +             rc = -ENODEV;
> > +             goto out_ids_cleanup;
> > +     }
> > +
> > +     /* We don't need MMIO arrays anymore so let's free-up */
> > +     kfree(mmios_va);
> > +     kfree(mmios);
> > +
> > +     return 0;
> > +
> > +out_ids_cleanup:
> > +     imsic_ids_cleanup();
> > +out_iounmap:
> > +     for (i = 0; i < num_mmios; i++) {
> > +             if (mmios_va[i])
> > +                     iounmap(mmios_va[i]);
> > +     }
> > +     kfree(mmios_va);
> > +     kfree(mmios);
> > +out_free_local:
> > +     free_percpu(imsic->global.local);
> > +out_free_priv:
> > +     kfree(imsic);
> > +     imsic = NULL;
> > +     return rc;
> > +}
> > diff --git a/drivers/irqchip/irq-riscv-imsic-state.h b/drivers/irqchip/irq-riscv-imsic-state.h
> > new file mode 100644
> > index 000000000000..3170018949a8
> > --- /dev/null
> > +++ b/drivers/irqchip/irq-riscv-imsic-state.h
> > @@ -0,0 +1,66 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only */
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +
> > +#ifndef _IRQ_RISCV_IMSIC_STATE_H
> > +#define _IRQ_RISCV_IMSIC_STATE_H
> > +
> > +#include <linux/irqchip/riscv-imsic.h>
> > +#include <linux/irqdomain.h>
> > +#include <linux/fwnode.h>
> > +
> > +struct imsic_priv {
> > +     /* Device details */
> > +     struct fwnode_handle *fwnode;
> > +
> > +     /* Global configuration common for all HARTs */
> > +     struct imsic_global_config global;
> > +
> > +     /* Global state of interrupt identities */
> > +     raw_spinlock_t ids_lock;
> > +     unsigned long *ids_used_bimap;
> > +     unsigned long *ids_enabled_bimap;
> > +     unsigned int *ids_target_cpu;
> > +
> > +     /* IPI interrupt identity and synchronization */
> > +     u32 ipi_id;
> > +     int ipi_virq;
> > +     struct irq_desc *ipi_lsync_desc;
> > +
> > +     /* IRQ domains (created by platform driver) */
> > +     struct irq_domain *base_domain;
> > +     struct irq_domain *plat_domain;
> > +};
> > +
> > +extern struct imsic_priv *imsic;
> > +
> > +void __imsic_eix_update(unsigned long base_id,
> > +                     unsigned long num_id, bool pend, bool val);
> > +
> > +#define __imsic_id_enable(__id)              \
> > +     __imsic_eix_update((__id), 1, false, true)
> > +#define __imsic_id_disable(__id)     \
> > +     __imsic_eix_update((__id), 1, false, false)
> > +
> > +void imsic_id_set_target(unsigned int id, unsigned int target_cpu);
> > +unsigned int imsic_id_get_target(unsigned int id);
> > +
> > +void imsic_ids_local_sync(void);
> > +void imsic_ids_local_delivery(bool enable);
> > +
> > +#ifdef CONFIG_SMP
> > +void imsic_ids_remote_sync(void);
> > +#else
> > +static inline void imsic_ids_remote_sync(void)
> > +{
> > +}
> > +#endif
> > +
> > +int imsic_ids_alloc(unsigned int order);
> > +void imsic_ids_free(unsigned int base_id, unsigned int order);
> > +
> > +int imsic_setup_state(struct fwnode_handle *fwnode);
> > +
> > +#endif
> > diff --git a/include/linux/irqchip/riscv-imsic.h b/include/linux/irqchip/riscv-imsic.h
> > new file mode 100644
> > index 000000000000..1f6fc9a57218
> > --- /dev/null
> > +++ b/include/linux/irqchip/riscv-imsic.h
> > @@ -0,0 +1,86 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only */
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +#ifndef __LINUX_IRQCHIP_RISCV_IMSIC_H
> > +#define __LINUX_IRQCHIP_RISCV_IMSIC_H
> > +
> > +#include <linux/types.h>
> > +#include <asm/csr.h>
> > +
> > +#define IMSIC_MMIO_PAGE_SHIFT                12
> > +#define IMSIC_MMIO_PAGE_SZ           (1UL << IMSIC_MMIO_PAGE_SHIFT)
> > +#define IMSIC_MMIO_PAGE_LE           0x00
> > +#define IMSIC_MMIO_PAGE_BE           0x04
> > +
> > +#define IMSIC_MIN_ID                 63
> > +#define IMSIC_MAX_ID                 2048
> > +
> > +#define IMSIC_EIDELIVERY             0x70
> > +
> > +#define IMSIC_EITHRESHOLD            0x72
> > +
> > +#define IMSIC_EIP0                   0x80
> > +#define IMSIC_EIP63                  0xbf
> > +#define IMSIC_EIPx_BITS                      32
> > +
> > +#define IMSIC_EIE0                   0xc0
> > +#define IMSIC_EIE63                  0xff
> > +#define IMSIC_EIEx_BITS                      32
> > +
> > +#define IMSIC_FIRST                  IMSIC_EIDELIVERY
> > +#define IMSIC_LAST                   IMSIC_EIE63
> > +
> > +#define IMSIC_MMIO_SETIPNUM_LE               0x00
> > +#define IMSIC_MMIO_SETIPNUM_BE               0x04
> > +
> > +struct imsic_local_config {
> > +     phys_addr_t msi_pa;
> > +     void __iomem *msi_va;
> > +};
> > +
> > +struct imsic_global_config {
> > +     /*
> > +      * MSI Target Address Scheme
> > +      *
> > +      * XLEN-1                                                12     0
> > +      * |                                                     |     |
> > +      * -------------------------------------------------------------
> > +      * |xxxxxx|Group Index|xxxxxxxxxxx|HART Index|Guest Index|  0  |
> > +      * -------------------------------------------------------------
> > +      */
> > +
> > +     /* Bits representing Guest index, HART index, and Group index */
> > +     u32 guest_index_bits;
> > +     u32 hart_index_bits;
> > +     u32 group_index_bits;
> > +     u32 group_index_shift;
> > +
> > +     /* Global base address matching all target MSI addresses */
> > +     phys_addr_t base_addr;
> > +
> > +     /* Number of interrupt identities */
> > +     u32 nr_ids;
> > +
> > +     /* Number of guest interrupt identities */
> > +     u32 nr_guest_ids;
> > +
> > +     /* Per-CPU IMSIC addresses */
> > +     struct imsic_local_config __percpu *local;
> > +};
> > +
> > +#ifdef CONFIG_RISCV_IMSIC
> > +
> > +extern const struct imsic_global_config *imsic_get_global_config(void);
> > +
> > +#else
> > +
> > +static inline const struct imsic_global_config *imsic_get_global_config(void)
> > +{
> > +     return NULL;
> > +}
> > +
> > +#endif
> > +
> > +#endif
> > --
> > 2.34.1
> >

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Re: [PATCH v8 13/16] irqchip: Add RISC-V advanced PLIC driver for direct-mode

[Anup Patel]

On Mon, Sep 25, 2023 at 1:26 PM Sunil V L <sunilvl@ventanamicro.com> wrote:
>
> Hi Anup,
>
> On Tue, Sep 12, 2023 at 11:19:25PM +0530, Anup Patel wrote:
> > The RISC-V advanced interrupt architecture (AIA) specification defines
> > advanced platform-level interrupt controller (APLIC) which has two modes
> > of operation: 1) Direct mode and 2) MSI mode.
> > (For more details, refer https://github.com/riscv/riscv-aia)
> >
> > In APLIC direct-mode, wired interrupts are forwared to CPUs (or HARTs)
> > as a local external interrupt.
> >
> > We add a platform irqchip driver for the RISC-V APLIC direct-mode to
> > support RISC-V platforms having only wired interrupts.
> >
> > Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> > ---
> >  drivers/irqchip/Kconfig                  |   5 +
> >  drivers/irqchip/Makefile                 |   1 +
> >  drivers/irqchip/irq-riscv-aplic-direct.c | 326 +++++++++++++++++++++++
> >  drivers/irqchip/irq-riscv-aplic-main.c   | 240 +++++++++++++++++
> >  drivers/irqchip/irq-riscv-aplic-main.h   |  45 ++++
> >  include/linux/irqchip/riscv-aplic.h      | 119 +++++++++
> >  6 files changed, 736 insertions(+)
> >  create mode 100644 drivers/irqchip/irq-riscv-aplic-direct.c
> >  create mode 100644 drivers/irqchip/irq-riscv-aplic-main.c
> >  create mode 100644 drivers/irqchip/irq-riscv-aplic-main.h
> >  create mode 100644 include/linux/irqchip/riscv-aplic.h
> >
> > diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> > index a6aad78076a0..44c455084d09 100644
> > --- a/drivers/irqchip/Kconfig
> > +++ b/drivers/irqchip/Kconfig
> > @@ -545,6 +545,11 @@ config SIFIVE_PLIC
> >       select IRQ_DOMAIN_HIERARCHY
> >       select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
> >
> > +config RISCV_APLIC
> > +     bool
> > +     depends on RISCV
> > +     select IRQ_DOMAIN_HIERARCHY
> > +
> >  config RISCV_IMSIC
> >       bool
> >       depends on RISCV
> > diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> > index abca445a3229..7f8289790ed8 100644
> > --- a/drivers/irqchip/Makefile
> > +++ b/drivers/irqchip/Makefile
> > @@ -95,6 +95,7 @@ obj-$(CONFIG_QCOM_MPM)                      += irq-qcom-mpm.o
> >  obj-$(CONFIG_CSKY_MPINTC)            += irq-csky-mpintc.o
> >  obj-$(CONFIG_CSKY_APB_INTC)          += irq-csky-apb-intc.o
> >  obj-$(CONFIG_RISCV_INTC)             += irq-riscv-intc.o
> > +obj-$(CONFIG_RISCV_APLIC)            += irq-riscv-aplic-main.o irq-riscv-aplic-direct.o
> >  obj-$(CONFIG_RISCV_IMSIC)            += irq-riscv-imsic-state.o irq-riscv-imsic-early.o irq-riscv-imsic-platform.o
> >  obj-$(CONFIG_SIFIVE_PLIC)            += irq-sifive-plic.o
> >  obj-$(CONFIG_IMX_IRQSTEER)           += irq-imx-irqsteer.o
> > diff --git a/drivers/irqchip/irq-riscv-aplic-direct.c b/drivers/irqchip/irq-riscv-aplic-direct.c
> > new file mode 100644
> > index 000000000000..e36d655a1490
> > --- /dev/null
> > +++ b/drivers/irqchip/irq-riscv-aplic-direct.c
> > @@ -0,0 +1,326 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +
> > +#include <linux/bitops.h>
> > +#include <linux/cpu.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/irqchip.h>
> > +#include <linux/irqchip/chained_irq.h>
> > +#include <linux/irqchip/riscv-aplic.h>
> > +#include <linux/module.h>
> > +#include <linux/of_address.h>
> > +#include <linux/printk.h>
> > +#include <linux/smp.h>
> > +
> > +#include "irq-riscv-aplic-main.h"
> > +
> > +#define APLIC_DISABLE_IDELIVERY              0
> > +#define APLIC_ENABLE_IDELIVERY               1
> > +#define APLIC_DISABLE_ITHRESHOLD     1
> > +#define APLIC_ENABLE_ITHRESHOLD              0
> > +
> > +struct aplic_direct {
> > +     struct aplic_priv       priv;
> > +     struct irq_domain       *irqdomain;
> > +     struct cpumask          lmask;
> > +};
> > +
> > +struct aplic_idc {
> > +     unsigned int            hart_index;
> > +     void __iomem            *regs;
> > +     struct aplic_direct     *direct;
> > +};
> > +
> > +static unsigned int aplic_direct_parent_irq;
> > +static DEFINE_PER_CPU(struct aplic_idc, aplic_idcs);
> > +
> > +static void aplic_direct_irq_eoi(struct irq_data *d)
> > +{
> > +     /*
> > +      * The fasteoi_handler requires irq_eoi() callback hence
> > +      * provide a dummy handler.
> > +      */
> > +}
> > +
> > +#ifdef CONFIG_SMP
> > +static int aplic_direct_set_affinity(struct irq_data *d,
> > +                               const struct cpumask *mask_val, bool force)
> > +{
> > +     struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
> > +     struct aplic_direct *direct =
> > +                     container_of(priv, struct aplic_direct, priv);
> > +     struct aplic_idc *idc;
> > +     unsigned int cpu, val;
> > +     struct cpumask amask;
> > +     void __iomem *target;
> > +
> > +     cpumask_and(&amask, &direct->lmask, mask_val);
> > +
> > +     if (force)
> > +             cpu = cpumask_first(&amask);
> > +     else
> > +             cpu = cpumask_any_and(&amask, cpu_online_mask);
> > +
> > +     if (cpu >= nr_cpu_ids)
> > +             return -EINVAL;
> > +
> > +     idc = per_cpu_ptr(&aplic_idcs, cpu);
> > +     target = priv->regs + APLIC_TARGET_BASE;
> > +     target += (d->hwirq - 1) * sizeof(u32);
> > +     val = idc->hart_index & APLIC_TARGET_HART_IDX_MASK;
> > +     val <<= APLIC_TARGET_HART_IDX_SHIFT;
> > +     val |= APLIC_DEFAULT_PRIORITY;
> > +     writel(val, target);
> > +
> > +     irq_data_update_effective_affinity(d, cpumask_of(cpu));
> > +
> > +     return IRQ_SET_MASK_OK_DONE;
> > +}
> > +#endif
> > +
> > +static struct irq_chip aplic_direct_chip = {
> > +     .name           = "APLIC-DIRECT",
> > +     .irq_mask       = aplic_irq_mask,
> > +     .irq_unmask     = aplic_irq_unmask,
> > +     .irq_set_type   = aplic_irq_set_type,
> > +     .irq_eoi        = aplic_direct_irq_eoi,
> > +#ifdef CONFIG_SMP
> > +     .irq_set_affinity = aplic_direct_set_affinity,
> > +#endif
> > +     .flags          = IRQCHIP_SET_TYPE_MASKED |
> > +                       IRQCHIP_SKIP_SET_WAKE |
> > +                       IRQCHIP_MASK_ON_SUSPEND,
> > +};
> > +
> > +static int aplic_direct_irqdomain_translate(struct irq_domain *d,
> > +                                      struct irq_fwspec *fwspec,
> > +                                      unsigned long *hwirq,
> > +                                      unsigned int *type)
> > +{
> > +     struct aplic_priv *priv = d->host_data;
> > +
> > +     return aplic_irqdomain_translate(fwspec, priv->gsi_base,
> > +                                      hwirq, type);
> > +}
> > +
> > +static int aplic_direct_irqdomain_alloc(struct irq_domain *domain,
> > +                                  unsigned int virq, unsigned int nr_irqs,
> > +                                  void *arg)
> > +{
> > +     int i, ret;
> > +     unsigned int type;
> > +     irq_hw_number_t hwirq;
> > +     struct irq_fwspec *fwspec = arg;
> > +     struct aplic_priv *priv = domain->host_data;
> > +     struct aplic_direct *direct =
> > +                     container_of(priv, struct aplic_direct, priv);
> > +
> > +     ret = aplic_irqdomain_translate(fwspec, priv->gsi_base,
> > +                                     &hwirq, &type);
> > +     if (ret)
> > +             return ret;
> > +
> > +     for (i = 0; i < nr_irqs; i++) {
> > +             irq_domain_set_info(domain, virq + i, hwirq + i,
> > +                                 &aplic_direct_chip, priv,
> > +                                 handle_fasteoi_irq, NULL, NULL);
> > +             irq_set_affinity(virq + i, &direct->lmask);
> > +             /* See the reason described in aplic_msi_irqdomain_alloc() */
> > +             irq_set_status_flags(virq + i, IRQ_DISABLE_UNLAZY);
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +static const struct irq_domain_ops aplic_direct_irqdomain_ops = {
> > +     .translate      = aplic_direct_irqdomain_translate,
> > +     .alloc          = aplic_direct_irqdomain_alloc,
> > +     .free           = irq_domain_free_irqs_top,
> > +};
> > +
> > +/*
> > + * To handle an APLIC direct interrupts, we just read the CLAIMI register
> > + * which will return highest priority pending interrupt and clear the
> > + * pending bit of the interrupt. This process is repeated until CLAIMI
> > + * register return zero value.
> > + */
> > +static void aplic_direct_handle_irq(struct irq_desc *desc)
> > +{
> > +     struct aplic_idc *idc = this_cpu_ptr(&aplic_idcs);
> > +     struct irq_chip *chip = irq_desc_get_chip(desc);
> > +     struct irq_domain *irqdomain = idc->direct->irqdomain;
> > +     irq_hw_number_t hw_irq;
> > +     int irq;
> > +
> > +     chained_irq_enter(chip, desc);
> > +
> > +     while ((hw_irq = readl(idc->regs + APLIC_IDC_CLAIMI))) {
> > +             hw_irq = hw_irq >> APLIC_IDC_TOPI_ID_SHIFT;
> > +             irq = irq_find_mapping(irqdomain, hw_irq);
> > +
> > +             if (unlikely(irq <= 0))
> > +                     dev_warn_ratelimited(idc->direct->priv.dev,
> > +                                          "hw_irq %lu mapping not found\n",
> > +                                          hw_irq);
> > +             else
> > +                     generic_handle_irq(irq);
> > +     }
> > +
> > +     chained_irq_exit(chip, desc);
> > +}
> > +
> > +static void aplic_idc_set_delivery(struct aplic_idc *idc, bool en)
> > +{
> > +     u32 de = (en) ? APLIC_ENABLE_IDELIVERY : APLIC_DISABLE_IDELIVERY;
> > +     u32 th = (en) ? APLIC_ENABLE_ITHRESHOLD : APLIC_DISABLE_ITHRESHOLD;
> > +
> > +     /* Priority must be less than threshold for interrupt triggering */
> > +     writel(th, idc->regs + APLIC_IDC_ITHRESHOLD);
> > +
> > +     /* Delivery must be set to 1 for interrupt triggering */
> > +     writel(de, idc->regs + APLIC_IDC_IDELIVERY);
> > +}
> > +
> > +static int aplic_direct_dying_cpu(unsigned int cpu)
> > +{
> > +     if (aplic_direct_parent_irq)
> > +             disable_percpu_irq(aplic_direct_parent_irq);
> > +
> > +     return 0;
> > +}
> > +
> > +static int aplic_direct_starting_cpu(unsigned int cpu)
> > +{
> > +     if (aplic_direct_parent_irq)
> > +             enable_percpu_irq(aplic_direct_parent_irq,
> > +                             irq_get_trigger_type(aplic_direct_parent_irq));
> > +
> > +     return 0;
> > +}
> > +
> > +int aplic_direct_setup(struct device *dev, void __iomem *regs)
> > +{
> > +     int i, j, rc, cpu, setup_count = 0;
> > +     struct fwnode_reference_args parent;
> > +     struct aplic_direct *direct;
> > +     struct aplic_priv *priv;
> > +     struct irq_domain *domain;
> > +     unsigned long hartid;
> > +     struct aplic_idc *idc;
> > +     u32 val;
> > +
> > +     direct = kzalloc(sizeof(*direct), GFP_KERNEL);
> > +     if (!direct)
> > +             return -ENOMEM;
> > +     priv = &direct->priv;
> > +
> > +     rc = aplic_setup_priv(priv, dev, regs);
> > +     if (rc) {
> > +             dev_err(dev, "failed to create APLIC context\n");
> > +             kfree(direct);
> > +             return rc;
> > +     }
> > +
> > +     /* Setup per-CPU IDC and target CPU mask */
> > +     for (i = 0; i < priv->nr_idcs; i++) {
> > +             rc = fwnode_property_get_reference_args(dev->fwnode,
> > +                             "interrupts-extended", "#interrupt-cells",
> > +                             0, i, &parent);
> > +             if (rc) {
> > +                     dev_warn(dev, "parent irq for IDC%d not found\n", i);
> > +                     continue;
> > +             }
> > +
> > +             /*
> > +              * Skip interrupts other than external interrupts for
> > +              * current privilege level.
> > +              */
> > +             if (parent.args[0] != RV_IRQ_EXT)
> > +                     continue;
> > +
> > +             rc = riscv_get_intc_hartid(parent.fwnode, &hartid);
> > +             if (rc) {
> > +                     dev_warn(dev, "invalid hartid for IDC%d\n", i);
> > +                     continue;
> > +             }
> > +
> > +             cpu = riscv_hartid_to_cpuid(hartid);
> > +             if (cpu < 0) {
> > +                     dev_warn(dev, "invalid cpuid for IDC%d\n", i);
> > +                     continue;
> > +             }
> > +
> > +             cpumask_set_cpu(cpu, &direct->lmask);
> > +
> > +             idc = per_cpu_ptr(&aplic_idcs, cpu);
> > +             idc->hart_index = i;
> > +             idc->regs = priv->regs + APLIC_IDC_BASE + i * APLIC_IDC_SIZE;
> > +             idc->direct = direct;
> > +
> > +             aplic_idc_set_delivery(idc, true);
> > +
> > +             /*
> > +              * Boot cpu might not have APLIC hart_index = 0 so check
> > +              * and update target registers of all interrupts.
> > +              */
> > +             if (cpu == smp_processor_id() && idc->hart_index) {
> > +                     val = idc->hart_index & APLIC_TARGET_HART_IDX_MASK;
> > +                     val <<= APLIC_TARGET_HART_IDX_SHIFT;
> > +                     val |= APLIC_DEFAULT_PRIORITY;
> > +                     for (j = 1; j <= priv->nr_irqs; j++)
> > +                             writel(val, priv->regs + APLIC_TARGET_BASE +
> > +                                         (j - 1) * sizeof(u32));
> > +             }
> > +
> > +             setup_count++;
> > +     }
> > +
> > +     /* Find parent domain and register chained handler */
> > +     domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
> > +                                       DOMAIN_BUS_ANY);
> > +     if (!aplic_direct_parent_irq && domain) {
> > +             aplic_direct_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT);
> > +             if (aplic_direct_parent_irq) {
> > +                     irq_set_chained_handler(aplic_direct_parent_irq,
> > +                                             aplic_direct_handle_irq);
> > +
> > +                     /*
> > +                      * Setup CPUHP notifier to enable parent
> > +                      * interrupt on all CPUs
> > +                      */
> > +                     cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
> > +                                       "irqchip/riscv/aplic:starting",
> > +                                       aplic_direct_starting_cpu,
> > +                                       aplic_direct_dying_cpu);
> > +             }
> > +     }
> > +
> > +     /* Fail if we were not able to setup IDC for any CPU */
> > +     if (!setup_count) {
> > +             kfree(direct);
> > +             return -ENODEV;
> > +     }
> > +
> > +     /* Setup global config and interrupt delivery */
> > +     aplic_init_hw_global(priv, false);
> > +
> > +     /* Create irq domain instance for the APLIC */
> > +     direct->irqdomain = irq_domain_create_linear(dev->fwnode,
> > +                                                priv->nr_irqs + 1,
> > +                                                &aplic_direct_irqdomain_ops,
> > +                                                priv);
> > +     if (!direct->irqdomain) {
> > +             dev_err(dev, "failed to create direct irq domain\n");
> > +             kfree(direct);
> > +             return -ENOMEM;
> > +     }
> > +
> > +     /* Advertise the interrupt controller */
> > +     dev_info(dev, "%d interrupts directly connected to %d CPUs\n",
> > +              priv->nr_irqs, priv->nr_idcs);
> > +
> > +     return 0;
> > +}
> > diff --git a/drivers/irqchip/irq-riscv-aplic-main.c b/drivers/irqchip/irq-riscv-aplic-main.c
> > new file mode 100644
> > index 000000000000..d62a096774c4
> > --- /dev/null
> > +++ b/drivers/irqchip/irq-riscv-aplic-main.c
> > @@ -0,0 +1,240 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +
> > +#include <linux/printk.h>
> > +#include <linux/module.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/irqchip/riscv-aplic.h>
> > +
> > +#include "irq-riscv-aplic-main.h"
> > +
> > +void aplic_irq_unmask(struct irq_data *d)
> > +{
> > +     struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
> > +
> > +     writel(d->hwirq, priv->regs + APLIC_SETIENUM);
> > +}
> > +
> > +void aplic_irq_mask(struct irq_data *d)
> > +{
> > +     struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
> > +
> > +     writel(d->hwirq, priv->regs + APLIC_CLRIENUM);
> > +}
> > +
> > +int aplic_irq_set_type(struct irq_data *d, unsigned int type)
> > +{
> > +     u32 val = 0;
> > +     void __iomem *sourcecfg;
> > +     struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
> > +
> > +     switch (type) {
> > +     case IRQ_TYPE_NONE:
> > +             val = APLIC_SOURCECFG_SM_INACTIVE;
> > +             break;
> > +     case IRQ_TYPE_LEVEL_LOW:
> > +             val = APLIC_SOURCECFG_SM_LEVEL_LOW;
> > +             break;
> > +     case IRQ_TYPE_LEVEL_HIGH:
> > +             val = APLIC_SOURCECFG_SM_LEVEL_HIGH;
> > +             break;
> > +     case IRQ_TYPE_EDGE_FALLING:
> > +             val = APLIC_SOURCECFG_SM_EDGE_FALL;
> > +             break;
> > +     case IRQ_TYPE_EDGE_RISING:
> > +             val = APLIC_SOURCECFG_SM_EDGE_RISE;
> > +             break;
> > +     default:
> > +             return -EINVAL;
> > +     }
> > +
> > +     sourcecfg = priv->regs + APLIC_SOURCECFG_BASE;
> > +     sourcecfg += (d->hwirq - 1) * sizeof(u32);
> > +     writel(val, sourcecfg);
> > +
> > +     return 0;
> > +}
> > +
> > +int aplic_irqdomain_translate(struct irq_fwspec *fwspec, u32 gsi_base,
> > +                           unsigned long *hwirq, unsigned int *type)
> > +{
> > +     if (WARN_ON(fwspec->param_count < 2))
> > +             return -EINVAL;
> > +     if (WARN_ON(!fwspec->param[0]))
> > +             return -EINVAL;
> > +
> > +     /* For DT, gsi_base is always zero. */
> > +     *hwirq = fwspec->param[0] - gsi_base;
> > +     *type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
> > +
> > +     WARN_ON(*type == IRQ_TYPE_NONE);
> > +
> > +     return 0;
> > +}
> > +
> > +void aplic_init_hw_global(struct aplic_priv *priv, bool msi_mode)
> > +{
> > +     u32 val;
> > +#ifdef CONFIG_RISCV_M_MODE
> > +     u32 valH;
> > +
> > +     if (msi_mode) {
> > +             val = priv->msicfg.base_ppn;
> > +             valH = ((u64)priv->msicfg.base_ppn >> 32) &
> > +                     APLIC_xMSICFGADDRH_BAPPN_MASK;
> > +             valH |= (priv->msicfg.lhxw & APLIC_xMSICFGADDRH_LHXW_MASK)
> > +                     << APLIC_xMSICFGADDRH_LHXW_SHIFT;
> > +             valH |= (priv->msicfg.hhxw & APLIC_xMSICFGADDRH_HHXW_MASK)
> > +                     << APLIC_xMSICFGADDRH_HHXW_SHIFT;
> > +             valH |= (priv->msicfg.lhxs & APLIC_xMSICFGADDRH_LHXS_MASK)
> > +                     << APLIC_xMSICFGADDRH_LHXS_SHIFT;
> > +             valH |= (priv->msicfg.hhxs & APLIC_xMSICFGADDRH_HHXS_MASK)
> > +                     << APLIC_xMSICFGADDRH_HHXS_SHIFT;
> > +             writel(val, priv->regs + APLIC_xMSICFGADDR);
> > +             writel(valH, priv->regs + APLIC_xMSICFGADDRH);
> > +     }
> > +#endif
> > +
> > +     /* Setup APLIC domaincfg register */
> > +     val = readl(priv->regs + APLIC_DOMAINCFG);
> > +     val |= APLIC_DOMAINCFG_IE;
> > +     if (msi_mode)
> > +             val |= APLIC_DOMAINCFG_DM;
> > +     writel(val, priv->regs + APLIC_DOMAINCFG);
> > +     if (readl(priv->regs + APLIC_DOMAINCFG) != val)
> > +             dev_warn(priv->dev, "unable to write 0x%x in domaincfg\n",
> > +                      val);
> > +}
> > +
> > +static void aplic_init_hw_irqs(struct aplic_priv *priv)
> > +{
> > +     int i;
> > +
> > +     /* Disable all interrupts */
> > +     for (i = 0; i <= priv->nr_irqs; i += 32)
> > +             writel(-1U, priv->regs + APLIC_CLRIE_BASE +
> > +                         (i / 32) * sizeof(u32));
> > +
> > +     /* Set interrupt type and default priority for all interrupts */
> > +     for (i = 1; i <= priv->nr_irqs; i++) {
> > +             writel(0, priv->regs + APLIC_SOURCECFG_BASE +
> > +                       (i - 1) * sizeof(u32));
> > +             writel(APLIC_DEFAULT_PRIORITY,
> > +                    priv->regs + APLIC_TARGET_BASE +
> > +                    (i - 1) * sizeof(u32));
> > +     }
> > +
> > +     /* Clear APLIC domaincfg */
> > +     writel(0, priv->regs + APLIC_DOMAINCFG);
> > +}
> > +
> > +int aplic_setup_priv(struct aplic_priv *priv, struct device *dev,
> > +                  void __iomem *regs)
> > +{
> > +     struct fwnode_reference_args parent;
> > +     int rc;
> > +
> > +     /* Save device pointer and register base */
> > +     priv->dev = dev;
> > +     priv->regs = regs;
> > +
> > +     /*
> > +      * Find out GSI base number
> > +      *
> > +      * Note: DT does not define "riscv,gsi-base" property so GSI
> > +      * base is always zero for DT.
> > +      */
> > +     rc = fwnode_property_read_u32_array(dev->fwnode, "riscv,gsi-base",
> > +                                         &priv->gsi_base, 1);
> For DT, you can just initialize this to 0 without reading the property.

Okay, I will update.

>
> > +     if (rc)
> > +             priv->gsi_base = 0;
> > +
> > +     /* Find out number of interrupt sources */
> > +     rc = fwnode_property_read_u32_array(dev->fwnode, "riscv,num-sources",
> > +                                         &priv->nr_irqs, 1);
> > +     if (rc) {
> > +             dev_err(dev, "failed to get number of interrupt sources\n");
> > +             return rc;
> > +     }
> > +
> > +     /* Setup initial state APLIC interrupts */
> > +     aplic_init_hw_irqs(priv);
> > +
> > +     /*
> > +      * Find out number of IDCs based on parent interrupts
> > +      *
> > +      * If "msi-parent" property is present then we ignore the
> > +      * APLIC IDCs which forces the APLIC driver to use MSI mode.
> > +      */
> > +     if (!fwnode_property_present(dev->fwnode, "msi-parent")) {
> > +             while (!fwnode_property_get_reference_args(dev->fwnode,
> > +                             "interrupts-extended", "#interrupt-cells",
> > +                             0, priv->nr_idcs, &parent))
> > +                     priv->nr_idcs++;
> > +     }
> > +
> Can this finding nr_idcs be done after aplic_init_hw_irqs() above?

Okay, I will update.

>
> > +     return 0;
> > +}
> > +
> > +static int aplic_probe(struct platform_device *pdev)
> > +{
> > +     struct device *dev = &pdev->dev;
> > +     struct resource *res;
> > +     void __iomem *regs;
> > +     int rc;
> > +
> > +     /* Map the MMIO registers */
> > +     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > +     if (!res) {
> > +             dev_err(dev, "failed to get MMIO resource\n");
> > +             return -EINVAL;
> > +     }
> > +     regs = devm_ioremap(&pdev->dev, res->start, resource_size(res));
> > +     if (!regs) {
> > +             dev_err(dev, "failed map MMIO registers\n");
> > +             return -ENOMEM;
> > +     }
> > +
> > +     /*
> > +      * If msi-parent property is present then setup APLIC MSI mode
> > +      * otherwise setup APLIC direct mode.
> > +      */
> > +     if (fwnode_property_present(dev->fwnode, "msi-parent"))
> Can this check be based on nr_idcs instead of checking for msi-parent
> again?

nr_idcs are not available at this point. I will think of something else
and maybe you can comment on v9 if it does not work for you.

>
> Thanks!
> Sunil
> > +             rc = -ENODEV;
> > +     else
> > +             rc = aplic_direct_setup(dev, regs);
> > +     if (rc) {
> > +             dev_err(dev, "failed setup APLIC in %s mode\n",
> > +                     fwnode_property_present(dev->fwnode, "msi-parent") ?
> > +                     "MSI" : "direct");
> > +             return rc;
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +static const struct of_device_id aplic_match[] = {
> > +     { .compatible = "riscv,aplic" },
> > +     {}
> > +};
> > +
> > +static struct platform_driver aplic_driver = {
> > +     .driver = {
> > +             .name           = "riscv-aplic",
> > +             .of_match_table = aplic_match,
> > +     },
> > +     .probe = aplic_probe,
> > +};
> > +
> > +static int __init aplic_init(void)
> > +{
> > +     /*
> > +      * Register APLIC driver as early as possible so that APLIC
> > +      * platform device is probed as soon as it is created.
> > +      */
> > +     return platform_driver_register(&aplic_driver);
> > +}
> > +core_initcall(aplic_init);
> > diff --git a/drivers/irqchip/irq-riscv-aplic-main.h b/drivers/irqchip/irq-riscv-aplic-main.h
> > new file mode 100644
> > index 000000000000..474a04229334
> > --- /dev/null
> > +++ b/drivers/irqchip/irq-riscv-aplic-main.h
> > @@ -0,0 +1,45 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only */
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +
> > +#ifndef _IRQ_RISCV_APLIC_MAIN_H
> > +#define _IRQ_RISCV_APLIC_MAIN_H
> > +
> > +#include <linux/device.h>
> > +#include <linux/io.h>
> > +#include <linux/irq.h>
> > +#include <linux/irqdomain.h>
> > +#include <linux/fwnode.h>
> > +
> > +#define APLIC_DEFAULT_PRIORITY               1
> > +
> > +struct aplic_msicfg {
> > +     phys_addr_t             base_ppn;
> > +     u32                     hhxs;
> > +     u32                     hhxw;
> > +     u32                     lhxs;
> > +     u32                     lhxw;
> > +};
> > +
> > +struct aplic_priv {
> > +     struct device           *dev;
> > +     u32                     gsi_base;
> > +     u32                     nr_irqs;
> > +     u32                     nr_idcs;
> > +     void __iomem            *regs;
> > +     struct aplic_msicfg     msicfg;
> > +};
> > +
> > +void aplic_irq_unmask(struct irq_data *d);
> > +void aplic_irq_mask(struct irq_data *d);
> > +int aplic_irq_set_type(struct irq_data *d, unsigned int type);
> > +int aplic_irqdomain_translate(struct irq_fwspec *fwspec, u32 gsi_base,
> > +                           unsigned long *hwirq, unsigned int *type);
> > +void aplic_init_hw_global(struct aplic_priv *priv, bool msi_mode);
> > +int aplic_setup_priv(struct aplic_priv *priv, struct device *dev,
> > +                  void __iomem *regs);
> > +int aplic_direct_setup(struct device *dev, void __iomem *regs);
> > +
> > +#endif
> > diff --git a/include/linux/irqchip/riscv-aplic.h b/include/linux/irqchip/riscv-aplic.h
> > new file mode 100644
> > index 000000000000..97e198ea0109
> > --- /dev/null
> > +++ b/include/linux/irqchip/riscv-aplic.h
> > @@ -0,0 +1,119 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only */
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +#ifndef __LINUX_IRQCHIP_RISCV_APLIC_H
> > +#define __LINUX_IRQCHIP_RISCV_APLIC_H
> > +
> > +#include <linux/bitops.h>
> > +
> > +#define APLIC_MAX_IDC                        BIT(14)
> > +#define APLIC_MAX_SOURCE             1024
> > +
> > +#define APLIC_DOMAINCFG                      0x0000
> > +#define APLIC_DOMAINCFG_RDONLY               0x80000000
> > +#define APLIC_DOMAINCFG_IE           BIT(8)
> > +#define APLIC_DOMAINCFG_DM           BIT(2)
> > +#define APLIC_DOMAINCFG_BE           BIT(0)
> > +
> > +#define APLIC_SOURCECFG_BASE         0x0004
> > +#define APLIC_SOURCECFG_D            BIT(10)
> > +#define APLIC_SOURCECFG_CHILDIDX_MASK        0x000003ff
> > +#define APLIC_SOURCECFG_SM_MASK      0x00000007
> > +#define APLIC_SOURCECFG_SM_INACTIVE  0x0
> > +#define APLIC_SOURCECFG_SM_DETACH    0x1
> > +#define APLIC_SOURCECFG_SM_EDGE_RISE 0x4
> > +#define APLIC_SOURCECFG_SM_EDGE_FALL 0x5
> > +#define APLIC_SOURCECFG_SM_LEVEL_HIGH        0x6
> > +#define APLIC_SOURCECFG_SM_LEVEL_LOW 0x7
> > +
> > +#define APLIC_MMSICFGADDR            0x1bc0
> > +#define APLIC_MMSICFGADDRH           0x1bc4
> > +#define APLIC_SMSICFGADDR            0x1bc8
> > +#define APLIC_SMSICFGADDRH           0x1bcc
> > +
> > +#ifdef CONFIG_RISCV_M_MODE
> > +#define APLIC_xMSICFGADDR            APLIC_MMSICFGADDR
> > +#define APLIC_xMSICFGADDRH           APLIC_MMSICFGADDRH
> > +#else
> > +#define APLIC_xMSICFGADDR            APLIC_SMSICFGADDR
> > +#define APLIC_xMSICFGADDRH           APLIC_SMSICFGADDRH
> > +#endif
> > +
> > +#define APLIC_xMSICFGADDRH_L         BIT(31)
> > +#define APLIC_xMSICFGADDRH_HHXS_MASK 0x1f
> > +#define APLIC_xMSICFGADDRH_HHXS_SHIFT        24
> > +#define APLIC_xMSICFGADDRH_LHXS_MASK 0x7
> > +#define APLIC_xMSICFGADDRH_LHXS_SHIFT        20
> > +#define APLIC_xMSICFGADDRH_HHXW_MASK 0x7
> > +#define APLIC_xMSICFGADDRH_HHXW_SHIFT        16
> > +#define APLIC_xMSICFGADDRH_LHXW_MASK 0xf
> > +#define APLIC_xMSICFGADDRH_LHXW_SHIFT        12
> > +#define APLIC_xMSICFGADDRH_BAPPN_MASK        0xfff
> > +
> > +#define APLIC_xMSICFGADDR_PPN_SHIFT  12
> > +
> > +#define APLIC_xMSICFGADDR_PPN_HART(__lhxs) \
> > +     (BIT(__lhxs) - 1)
> > +
> > +#define APLIC_xMSICFGADDR_PPN_LHX_MASK(__lhxw) \
> > +     (BIT(__lhxw) - 1)
> > +#define APLIC_xMSICFGADDR_PPN_LHX_SHIFT(__lhxs) \
> > +     ((__lhxs))
> > +#define APLIC_xMSICFGADDR_PPN_LHX(__lhxw, __lhxs) \
> > +     (APLIC_xMSICFGADDR_PPN_LHX_MASK(__lhxw) << \
> > +      APLIC_xMSICFGADDR_PPN_LHX_SHIFT(__lhxs))
> > +
> > +#define APLIC_xMSICFGADDR_PPN_HHX_MASK(__hhxw) \
> > +     (BIT(__hhxw) - 1)
> > +#define APLIC_xMSICFGADDR_PPN_HHX_SHIFT(__hhxs) \
> > +     ((__hhxs) + APLIC_xMSICFGADDR_PPN_SHIFT)
> > +#define APLIC_xMSICFGADDR_PPN_HHX(__hhxw, __hhxs) \
> > +     (APLIC_xMSICFGADDR_PPN_HHX_MASK(__hhxw) << \
> > +      APLIC_xMSICFGADDR_PPN_HHX_SHIFT(__hhxs))
> > +
> > +#define APLIC_IRQBITS_PER_REG                32
> > +
> > +#define APLIC_SETIP_BASE             0x1c00
> > +#define APLIC_SETIPNUM                       0x1cdc
> > +
> > +#define APLIC_CLRIP_BASE             0x1d00
> > +#define APLIC_CLRIPNUM                       0x1ddc
> > +
> > +#define APLIC_SETIE_BASE             0x1e00
> > +#define APLIC_SETIENUM                       0x1edc
> > +
> > +#define APLIC_CLRIE_BASE             0x1f00
> > +#define APLIC_CLRIENUM                       0x1fdc
> > +
> > +#define APLIC_SETIPNUM_LE            0x2000
> > +#define APLIC_SETIPNUM_BE            0x2004
> > +
> > +#define APLIC_GENMSI                 0x3000
> > +
> > +#define APLIC_TARGET_BASE            0x3004
> > +#define APLIC_TARGET_HART_IDX_SHIFT  18
> > +#define APLIC_TARGET_HART_IDX_MASK   0x3fff
> > +#define APLIC_TARGET_GUEST_IDX_SHIFT 12
> > +#define APLIC_TARGET_GUEST_IDX_MASK  0x3f
> > +#define APLIC_TARGET_IPRIO_MASK      0xff
> > +#define APLIC_TARGET_EIID_MASK       0x7ff
> > +
> > +#define APLIC_IDC_BASE                       0x4000
> > +#define APLIC_IDC_SIZE                       32
> > +
> > +#define APLIC_IDC_IDELIVERY          0x00
> > +
> > +#define APLIC_IDC_IFORCE             0x04
> > +
> > +#define APLIC_IDC_ITHRESHOLD         0x08
> > +
> > +#define APLIC_IDC_TOPI                       0x18
> > +#define APLIC_IDC_TOPI_ID_SHIFT      16
> > +#define APLIC_IDC_TOPI_ID_MASK       0x3ff
> > +#define APLIC_IDC_TOPI_PRIO_MASK     0xff
> > +
> > +#define APLIC_IDC_CLAIMI             0x1c
> > +
> > +#endif
> > --
> > 2.34.1
> >

Regards,
Anup

Re: [PATCH v8 13/16] irqchip: Add RISC-V advanced PLIC driver for direct-mode

[Anup Patel]

On Mon, Sep 25, 2023 at 1:26 PM Sunil V L <sunilvl@ventanamicro.com> wrote:
>
> Hi Anup,
>
> On Tue, Sep 12, 2023 at 11:19:25PM +0530, Anup Patel wrote:
> > The RISC-V advanced interrupt architecture (AIA) specification defines
> > advanced platform-level interrupt controller (APLIC) which has two modes
> > of operation: 1) Direct mode and 2) MSI mode.
> > (For more details, refer https://github.com/riscv/riscv-aia)
> >
> > In APLIC direct-mode, wired interrupts are forwared to CPUs (or HARTs)
> > as a local external interrupt.
> >
> > We add a platform irqchip driver for the RISC-V APLIC direct-mode to
> > support RISC-V platforms having only wired interrupts.
> >
> > Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> > ---
> >  drivers/irqchip/Kconfig                  |   5 +
> >  drivers/irqchip/Makefile                 |   1 +
> >  drivers/irqchip/irq-riscv-aplic-direct.c | 326 +++++++++++++++++++++++
> >  drivers/irqchip/irq-riscv-aplic-main.c   | 240 +++++++++++++++++
> >  drivers/irqchip/irq-riscv-aplic-main.h   |  45 ++++
> >  include/linux/irqchip/riscv-aplic.h      | 119 +++++++++
> >  6 files changed, 736 insertions(+)
> >  create mode 100644 drivers/irqchip/irq-riscv-aplic-direct.c
> >  create mode 100644 drivers/irqchip/irq-riscv-aplic-main.c
> >  create mode 100644 drivers/irqchip/irq-riscv-aplic-main.h
> >  create mode 100644 include/linux/irqchip/riscv-aplic.h
> >
> > diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> > index a6aad78076a0..44c455084d09 100644
> > --- a/drivers/irqchip/Kconfig
> > +++ b/drivers/irqchip/Kconfig
> > @@ -545,6 +545,11 @@ config SIFIVE_PLIC
> >       select IRQ_DOMAIN_HIERARCHY
> >       select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
> >
> > +config RISCV_APLIC
> > +     bool
> > +     depends on RISCV
> > +     select IRQ_DOMAIN_HIERARCHY
> > +
> >  config RISCV_IMSIC
> >       bool
> >       depends on RISCV
> > diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> > index abca445a3229..7f8289790ed8 100644
> > --- a/drivers/irqchip/Makefile
> > +++ b/drivers/irqchip/Makefile
> > @@ -95,6 +95,7 @@ obj-$(CONFIG_QCOM_MPM)                      += irq-qcom-mpm.o
> >  obj-$(CONFIG_CSKY_MPINTC)            += irq-csky-mpintc.o
> >  obj-$(CONFIG_CSKY_APB_INTC)          += irq-csky-apb-intc.o
> >  obj-$(CONFIG_RISCV_INTC)             += irq-riscv-intc.o
> > +obj-$(CONFIG_RISCV_APLIC)            += irq-riscv-aplic-main.o irq-riscv-aplic-direct.o
> >  obj-$(CONFIG_RISCV_IMSIC)            += irq-riscv-imsic-state.o irq-riscv-imsic-early.o irq-riscv-imsic-platform.o
> >  obj-$(CONFIG_SIFIVE_PLIC)            += irq-sifive-plic.o
> >  obj-$(CONFIG_IMX_IRQSTEER)           += irq-imx-irqsteer.o
> > diff --git a/drivers/irqchip/irq-riscv-aplic-direct.c b/drivers/irqchip/irq-riscv-aplic-direct.c
> > new file mode 100644
> > index 000000000000..e36d655a1490
> > --- /dev/null
> > +++ b/drivers/irqchip/irq-riscv-aplic-direct.c
> > @@ -0,0 +1,326 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +
> > +#include <linux/bitops.h>
> > +#include <linux/cpu.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/irqchip.h>
> > +#include <linux/irqchip/chained_irq.h>
> > +#include <linux/irqchip/riscv-aplic.h>
> > +#include <linux/module.h>
> > +#include <linux/of_address.h>
> > +#include <linux/printk.h>
> > +#include <linux/smp.h>
> > +
> > +#include "irq-riscv-aplic-main.h"
> > +
> > +#define APLIC_DISABLE_IDELIVERY              0
> > +#define APLIC_ENABLE_IDELIVERY               1
> > +#define APLIC_DISABLE_ITHRESHOLD     1
> > +#define APLIC_ENABLE_ITHRESHOLD              0
> > +
> > +struct aplic_direct {
> > +     struct aplic_priv       priv;
> > +     struct irq_domain       *irqdomain;
> > +     struct cpumask          lmask;
> > +};
> > +
> > +struct aplic_idc {
> > +     unsigned int            hart_index;
> > +     void __iomem            *regs;
> > +     struct aplic_direct     *direct;
> > +};
> > +
> > +static unsigned int aplic_direct_parent_irq;
> > +static DEFINE_PER_CPU(struct aplic_idc, aplic_idcs);
> > +
> > +static void aplic_direct_irq_eoi(struct irq_data *d)
> > +{
> > +     /*
> > +      * The fasteoi_handler requires irq_eoi() callback hence
> > +      * provide a dummy handler.
> > +      */
> > +}
> > +
> > +#ifdef CONFIG_SMP
> > +static int aplic_direct_set_affinity(struct irq_data *d,
> > +                               const struct cpumask *mask_val, bool force)
> > +{
> > +     struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
> > +     struct aplic_direct *direct =
> > +                     container_of(priv, struct aplic_direct, priv);
> > +     struct aplic_idc *idc;
> > +     unsigned int cpu, val;
> > +     struct cpumask amask;
> > +     void __iomem *target;
> > +
> > +     cpumask_and(&amask, &direct->lmask, mask_val);
> > +
> > +     if (force)
> > +             cpu = cpumask_first(&amask);
> > +     else
> > +             cpu = cpumask_any_and(&amask, cpu_online_mask);
> > +
> > +     if (cpu >= nr_cpu_ids)
> > +             return -EINVAL;
> > +
> > +     idc = per_cpu_ptr(&aplic_idcs, cpu);
> > +     target = priv->regs + APLIC_TARGET_BASE;
> > +     target += (d->hwirq - 1) * sizeof(u32);
> > +     val = idc->hart_index & APLIC_TARGET_HART_IDX_MASK;
> > +     val <<= APLIC_TARGET_HART_IDX_SHIFT;
> > +     val |= APLIC_DEFAULT_PRIORITY;
> > +     writel(val, target);
> > +
> > +     irq_data_update_effective_affinity(d, cpumask_of(cpu));
> > +
> > +     return IRQ_SET_MASK_OK_DONE;
> > +}
> > +#endif
> > +
> > +static struct irq_chip aplic_direct_chip = {
> > +     .name           = "APLIC-DIRECT",
> > +     .irq_mask       = aplic_irq_mask,
> > +     .irq_unmask     = aplic_irq_unmask,
> > +     .irq_set_type   = aplic_irq_set_type,
> > +     .irq_eoi        = aplic_direct_irq_eoi,
> > +#ifdef CONFIG_SMP
> > +     .irq_set_affinity = aplic_direct_set_affinity,
> > +#endif
> > +     .flags          = IRQCHIP_SET_TYPE_MASKED |
> > +                       IRQCHIP_SKIP_SET_WAKE |
> > +                       IRQCHIP_MASK_ON_SUSPEND,
> > +};
> > +
> > +static int aplic_direct_irqdomain_translate(struct irq_domain *d,
> > +                                      struct irq_fwspec *fwspec,
> > +                                      unsigned long *hwirq,
> > +                                      unsigned int *type)
> > +{
> > +     struct aplic_priv *priv = d->host_data;
> > +
> > +     return aplic_irqdomain_translate(fwspec, priv->gsi_base,
> > +                                      hwirq, type);
> > +}
> > +
> > +static int aplic_direct_irqdomain_alloc(struct irq_domain *domain,
> > +                                  unsigned int virq, unsigned int nr_irqs,
> > +                                  void *arg)
> > +{
> > +     int i, ret;
> > +     unsigned int type;
> > +     irq_hw_number_t hwirq;
> > +     struct irq_fwspec *fwspec = arg;
> > +     struct aplic_priv *priv = domain->host_data;
> > +     struct aplic_direct *direct =
> > +                     container_of(priv, struct aplic_direct, priv);
> > +
> > +     ret = aplic_irqdomain_translate(fwspec, priv->gsi_base,
> > +                                     &hwirq, &type);
> > +     if (ret)
> > +             return ret;
> > +
> > +     for (i = 0; i < nr_irqs; i++) {
> > +             irq_domain_set_info(domain, virq + i, hwirq + i,
> > +                                 &aplic_direct_chip, priv,
> > +                                 handle_fasteoi_irq, NULL, NULL);
> > +             irq_set_affinity(virq + i, &direct->lmask);
> > +             /* See the reason described in aplic_msi_irqdomain_alloc() */
> > +             irq_set_status_flags(virq + i, IRQ_DISABLE_UNLAZY);
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +static const struct irq_domain_ops aplic_direct_irqdomain_ops = {
> > +     .translate      = aplic_direct_irqdomain_translate,
> > +     .alloc          = aplic_direct_irqdomain_alloc,
> > +     .free           = irq_domain_free_irqs_top,
> > +};
> > +
> > +/*
> > + * To handle an APLIC direct interrupts, we just read the CLAIMI register
> > + * which will return highest priority pending interrupt and clear the
> > + * pending bit of the interrupt. This process is repeated until CLAIMI
> > + * register return zero value.
> > + */
> > +static void aplic_direct_handle_irq(struct irq_desc *desc)
> > +{
> > +     struct aplic_idc *idc = this_cpu_ptr(&aplic_idcs);
> > +     struct irq_chip *chip = irq_desc_get_chip(desc);
> > +     struct irq_domain *irqdomain = idc->direct->irqdomain;
> > +     irq_hw_number_t hw_irq;
> > +     int irq;
> > +
> > +     chained_irq_enter(chip, desc);
> > +
> > +     while ((hw_irq = readl(idc->regs + APLIC_IDC_CLAIMI))) {
> > +             hw_irq = hw_irq >> APLIC_IDC_TOPI_ID_SHIFT;
> > +             irq = irq_find_mapping(irqdomain, hw_irq);
> > +
> > +             if (unlikely(irq <= 0))
> > +                     dev_warn_ratelimited(idc->direct->priv.dev,
> > +                                          "hw_irq %lu mapping not found\n",
> > +                                          hw_irq);
> > +             else
> > +                     generic_handle_irq(irq);
> > +     }
> > +
> > +     chained_irq_exit(chip, desc);
> > +}
> > +
> > +static void aplic_idc_set_delivery(struct aplic_idc *idc, bool en)
> > +{
> > +     u32 de = (en) ? APLIC_ENABLE_IDELIVERY : APLIC_DISABLE_IDELIVERY;
> > +     u32 th = (en) ? APLIC_ENABLE_ITHRESHOLD : APLIC_DISABLE_ITHRESHOLD;
> > +
> > +     /* Priority must be less than threshold for interrupt triggering */
> > +     writel(th, idc->regs + APLIC_IDC_ITHRESHOLD);
> > +
> > +     /* Delivery must be set to 1 for interrupt triggering */
> > +     writel(de, idc->regs + APLIC_IDC_IDELIVERY);
> > +}
> > +
> > +static int aplic_direct_dying_cpu(unsigned int cpu)
> > +{
> > +     if (aplic_direct_parent_irq)
> > +             disable_percpu_irq(aplic_direct_parent_irq);
> > +
> > +     return 0;
> > +}
> > +
> > +static int aplic_direct_starting_cpu(unsigned int cpu)
> > +{
> > +     if (aplic_direct_parent_irq)
> > +             enable_percpu_irq(aplic_direct_parent_irq,
> > +                             irq_get_trigger_type(aplic_direct_parent_irq));
> > +
> > +     return 0;
> > +}
> > +
> > +int aplic_direct_setup(struct device *dev, void __iomem *regs)
> > +{
> > +     int i, j, rc, cpu, setup_count = 0;
> > +     struct fwnode_reference_args parent;
> > +     struct aplic_direct *direct;
> > +     struct aplic_priv *priv;
> > +     struct irq_domain *domain;
> > +     unsigned long hartid;
> > +     struct aplic_idc *idc;
> > +     u32 val;
> > +
> > +     direct = kzalloc(sizeof(*direct), GFP_KERNEL);
> > +     if (!direct)
> > +             return -ENOMEM;
> > +     priv = &direct->priv;
> > +
> > +     rc = aplic_setup_priv(priv, dev, regs);
> > +     if (rc) {
> > +             dev_err(dev, "failed to create APLIC context\n");
> > +             kfree(direct);
> > +             return rc;
> > +     }
> > +
> > +     /* Setup per-CPU IDC and target CPU mask */
> > +     for (i = 0; i < priv->nr_idcs; i++) {
> > +             rc = fwnode_property_get_reference_args(dev->fwnode,
> > +                             "interrupts-extended", "#interrupt-cells",
> > +                             0, i, &parent);
> > +             if (rc) {
> > +                     dev_warn(dev, "parent irq for IDC%d not found\n", i);
> > +                     continue;
> > +             }
> > +
> > +             /*
> > +              * Skip interrupts other than external interrupts for
> > +              * current privilege level.
> > +              */
> > +             if (parent.args[0] != RV_IRQ_EXT)
> > +                     continue;
> > +
> > +             rc = riscv_get_intc_hartid(parent.fwnode, &hartid);
> > +             if (rc) {
> > +                     dev_warn(dev, "invalid hartid for IDC%d\n", i);
> > +                     continue;
> > +             }
> > +
> > +             cpu = riscv_hartid_to_cpuid(hartid);
> > +             if (cpu < 0) {
> > +                     dev_warn(dev, "invalid cpuid for IDC%d\n", i);
> > +                     continue;
> > +             }
> > +
> > +             cpumask_set_cpu(cpu, &direct->lmask);
> > +
> > +             idc = per_cpu_ptr(&aplic_idcs, cpu);
> > +             idc->hart_index = i;
> > +             idc->regs = priv->regs + APLIC_IDC_BASE + i * APLIC_IDC_SIZE;
> > +             idc->direct = direct;
> > +
> > +             aplic_idc_set_delivery(idc, true);
> > +
> > +             /*
> > +              * Boot cpu might not have APLIC hart_index = 0 so check
> > +              * and update target registers of all interrupts.
> > +              */
> > +             if (cpu == smp_processor_id() && idc->hart_index) {
> > +                     val = idc->hart_index & APLIC_TARGET_HART_IDX_MASK;
> > +                     val <<= APLIC_TARGET_HART_IDX_SHIFT;
> > +                     val |= APLIC_DEFAULT_PRIORITY;
> > +                     for (j = 1; j <= priv->nr_irqs; j++)
> > +                             writel(val, priv->regs + APLIC_TARGET_BASE +
> > +                                         (j - 1) * sizeof(u32));
> > +             }
> > +
> > +             setup_count++;
> > +     }
> > +
> > +     /* Find parent domain and register chained handler */
> > +     domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
> > +                                       DOMAIN_BUS_ANY);
> > +     if (!aplic_direct_parent_irq && domain) {
> > +             aplic_direct_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT);
> > +             if (aplic_direct_parent_irq) {
> > +                     irq_set_chained_handler(aplic_direct_parent_irq,
> > +                                             aplic_direct_handle_irq);
> > +
> > +                     /*
> > +                      * Setup CPUHP notifier to enable parent
> > +                      * interrupt on all CPUs
> > +                      */
> > +                     cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
> > +                                       "irqchip/riscv/aplic:starting",
> > +                                       aplic_direct_starting_cpu,
> > +                                       aplic_direct_dying_cpu);
> > +             }
> > +     }
> > +
> > +     /* Fail if we were not able to setup IDC for any CPU */
> > +     if (!setup_count) {
> > +             kfree(direct);
> > +             return -ENODEV;
> > +     }
> > +
> > +     /* Setup global config and interrupt delivery */
> > +     aplic_init_hw_global(priv, false);
> > +
> > +     /* Create irq domain instance for the APLIC */
> > +     direct->irqdomain = irq_domain_create_linear(dev->fwnode,
> > +                                                priv->nr_irqs + 1,
> > +                                                &aplic_direct_irqdomain_ops,
> > +                                                priv);
> > +     if (!direct->irqdomain) {
> > +             dev_err(dev, "failed to create direct irq domain\n");
> > +             kfree(direct);
> > +             return -ENOMEM;
> > +     }
> > +
> > +     /* Advertise the interrupt controller */
> > +     dev_info(dev, "%d interrupts directly connected to %d CPUs\n",
> > +              priv->nr_irqs, priv->nr_idcs);
> > +
> > +     return 0;
> > +}
> > diff --git a/drivers/irqchip/irq-riscv-aplic-main.c b/drivers/irqchip/irq-riscv-aplic-main.c
> > new file mode 100644
> > index 000000000000..d62a096774c4
> > --- /dev/null
> > +++ b/drivers/irqchip/irq-riscv-aplic-main.c
> > @@ -0,0 +1,240 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +
> > +#include <linux/printk.h>
> > +#include <linux/module.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/irqchip/riscv-aplic.h>
> > +
> > +#include "irq-riscv-aplic-main.h"
> > +
> > +void aplic_irq_unmask(struct irq_data *d)
> > +{
> > +     struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
> > +
> > +     writel(d->hwirq, priv->regs + APLIC_SETIENUM);
> > +}
> > +
> > +void aplic_irq_mask(struct irq_data *d)
> > +{
> > +     struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
> > +
> > +     writel(d->hwirq, priv->regs + APLIC_CLRIENUM);
> > +}
> > +
> > +int aplic_irq_set_type(struct irq_data *d, unsigned int type)
> > +{
> > +     u32 val = 0;
> > +     void __iomem *sourcecfg;
> > +     struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
> > +
> > +     switch (type) {
> > +     case IRQ_TYPE_NONE:
> > +             val = APLIC_SOURCECFG_SM_INACTIVE;
> > +             break;
> > +     case IRQ_TYPE_LEVEL_LOW:
> > +             val = APLIC_SOURCECFG_SM_LEVEL_LOW;
> > +             break;
> > +     case IRQ_TYPE_LEVEL_HIGH:
> > +             val = APLIC_SOURCECFG_SM_LEVEL_HIGH;
> > +             break;
> > +     case IRQ_TYPE_EDGE_FALLING:
> > +             val = APLIC_SOURCECFG_SM_EDGE_FALL;
> > +             break;
> > +     case IRQ_TYPE_EDGE_RISING:
> > +             val = APLIC_SOURCECFG_SM_EDGE_RISE;
> > +             break;
> > +     default:
> > +             return -EINVAL;
> > +     }
> > +
> > +     sourcecfg = priv->regs + APLIC_SOURCECFG_BASE;
> > +     sourcecfg += (d->hwirq - 1) * sizeof(u32);
> > +     writel(val, sourcecfg);
> > +
> > +     return 0;
> > +}
> > +
> > +int aplic_irqdomain_translate(struct irq_fwspec *fwspec, u32 gsi_base,
> > +                           unsigned long *hwirq, unsigned int *type)
> > +{
> > +     if (WARN_ON(fwspec->param_count < 2))
> > +             return -EINVAL;
> > +     if (WARN_ON(!fwspec->param[0]))
> > +             return -EINVAL;
> > +
> > +     /* For DT, gsi_base is always zero. */
> > +     *hwirq = fwspec->param[0] - gsi_base;
> > +     *type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
> > +
> > +     WARN_ON(*type == IRQ_TYPE_NONE);
> > +
> > +     return 0;
> > +}
> > +
> > +void aplic_init_hw_global(struct aplic_priv *priv, bool msi_mode)
> > +{
> > +     u32 val;
> > +#ifdef CONFIG_RISCV_M_MODE
> > +     u32 valH;
> > +
> > +     if (msi_mode) {
> > +             val = priv->msicfg.base_ppn;
> > +             valH = ((u64)priv->msicfg.base_ppn >> 32) &
> > +                     APLIC_xMSICFGADDRH_BAPPN_MASK;
> > +             valH |= (priv->msicfg.lhxw & APLIC_xMSICFGADDRH_LHXW_MASK)
> > +                     << APLIC_xMSICFGADDRH_LHXW_SHIFT;
> > +             valH |= (priv->msicfg.hhxw & APLIC_xMSICFGADDRH_HHXW_MASK)
> > +                     << APLIC_xMSICFGADDRH_HHXW_SHIFT;
> > +             valH |= (priv->msicfg.lhxs & APLIC_xMSICFGADDRH_LHXS_MASK)
> > +                     << APLIC_xMSICFGADDRH_LHXS_SHIFT;
> > +             valH |= (priv->msicfg.hhxs & APLIC_xMSICFGADDRH_HHXS_MASK)
> > +                     << APLIC_xMSICFGADDRH_HHXS_SHIFT;
> > +             writel(val, priv->regs + APLIC_xMSICFGADDR);
> > +             writel(valH, priv->regs + APLIC_xMSICFGADDRH);
> > +     }
> > +#endif
> > +
> > +     /* Setup APLIC domaincfg register */
> > +     val = readl(priv->regs + APLIC_DOMAINCFG);
> > +     val |= APLIC_DOMAINCFG_IE;
> > +     if (msi_mode)
> > +             val |= APLIC_DOMAINCFG_DM;
> > +     writel(val, priv->regs + APLIC_DOMAINCFG);
> > +     if (readl(priv->regs + APLIC_DOMAINCFG) != val)
> > +             dev_warn(priv->dev, "unable to write 0x%x in domaincfg\n",
> > +                      val);
> > +}
> > +
> > +static void aplic_init_hw_irqs(struct aplic_priv *priv)
> > +{
> > +     int i;
> > +
> > +     /* Disable all interrupts */
> > +     for (i = 0; i <= priv->nr_irqs; i += 32)
> > +             writel(-1U, priv->regs + APLIC_CLRIE_BASE +
> > +                         (i / 32) * sizeof(u32));
> > +
> > +     /* Set interrupt type and default priority for all interrupts */
> > +     for (i = 1; i <= priv->nr_irqs; i++) {
> > +             writel(0, priv->regs + APLIC_SOURCECFG_BASE +
> > +                       (i - 1) * sizeof(u32));
> > +             writel(APLIC_DEFAULT_PRIORITY,
> > +                    priv->regs + APLIC_TARGET_BASE +
> > +                    (i - 1) * sizeof(u32));
> > +     }
> > +
> > +     /* Clear APLIC domaincfg */
> > +     writel(0, priv->regs + APLIC_DOMAINCFG);
> > +}
> > +
> > +int aplic_setup_priv(struct aplic_priv *priv, struct device *dev,
> > +                  void __iomem *regs)
> > +{
> > +     struct fwnode_reference_args parent;
> > +     int rc;
> > +
> > +     /* Save device pointer and register base */
> > +     priv->dev = dev;
> > +     priv->regs = regs;
> > +
> > +     /*
> > +      * Find out GSI base number
> > +      *
> > +      * Note: DT does not define "riscv,gsi-base" property so GSI
> > +      * base is always zero for DT.
> > +      */
> > +     rc = fwnode_property_read_u32_array(dev->fwnode, "riscv,gsi-base",
> > +                                         &priv->gsi_base, 1);
> For DT, you can just initialize this to 0 without reading the property.

Okay, I will update.

>
> > +     if (rc)
> > +             priv->gsi_base = 0;
> > +
> > +     /* Find out number of interrupt sources */
> > +     rc = fwnode_property_read_u32_array(dev->fwnode, "riscv,num-sources",
> > +                                         &priv->nr_irqs, 1);
> > +     if (rc) {
> > +             dev_err(dev, "failed to get number of interrupt sources\n");
> > +             return rc;
> > +     }
> > +
> > +     /* Setup initial state APLIC interrupts */
> > +     aplic_init_hw_irqs(priv);
> > +
> > +     /*
> > +      * Find out number of IDCs based on parent interrupts
> > +      *
> > +      * If "msi-parent" property is present then we ignore the
> > +      * APLIC IDCs which forces the APLIC driver to use MSI mode.
> > +      */
> > +     if (!fwnode_property_present(dev->fwnode, "msi-parent")) {
> > +             while (!fwnode_property_get_reference_args(dev->fwnode,
> > +                             "interrupts-extended", "#interrupt-cells",
> > +                             0, priv->nr_idcs, &parent))
> > +                     priv->nr_idcs++;
> > +     }
> > +
> Can this finding nr_idcs be done after aplic_init_hw_irqs() above?

Okay, I will update.

>
> > +     return 0;
> > +}
> > +
> > +static int aplic_probe(struct platform_device *pdev)
> > +{
> > +     struct device *dev = &pdev->dev;
> > +     struct resource *res;
> > +     void __iomem *regs;
> > +     int rc;
> > +
> > +     /* Map the MMIO registers */
> > +     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > +     if (!res) {
> > +             dev_err(dev, "failed to get MMIO resource\n");
> > +             return -EINVAL;
> > +     }
> > +     regs = devm_ioremap(&pdev->dev, res->start, resource_size(res));
> > +     if (!regs) {
> > +             dev_err(dev, "failed map MMIO registers\n");
> > +             return -ENOMEM;
> > +     }
> > +
> > +     /*
> > +      * If msi-parent property is present then setup APLIC MSI mode
> > +      * otherwise setup APLIC direct mode.
> > +      */
> > +     if (fwnode_property_present(dev->fwnode, "msi-parent"))
> Can this check be based on nr_idcs instead of checking for msi-parent
> again?

nr_idcs are not available at this point. I will think of something else
and maybe you can comment on v9 if it does not work for you.

>
> Thanks!
> Sunil
> > +             rc = -ENODEV;
> > +     else
> > +             rc = aplic_direct_setup(dev, regs);
> > +     if (rc) {
> > +             dev_err(dev, "failed setup APLIC in %s mode\n",
> > +                     fwnode_property_present(dev->fwnode, "msi-parent") ?
> > +                     "MSI" : "direct");
> > +             return rc;
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +static const struct of_device_id aplic_match[] = {
> > +     { .compatible = "riscv,aplic" },
> > +     {}
> > +};
> > +
> > +static struct platform_driver aplic_driver = {
> > +     .driver = {
> > +             .name           = "riscv-aplic",
> > +             .of_match_table = aplic_match,
> > +     },
> > +     .probe = aplic_probe,
> > +};
> > +
> > +static int __init aplic_init(void)
> > +{
> > +     /*
> > +      * Register APLIC driver as early as possible so that APLIC
> > +      * platform device is probed as soon as it is created.
> > +      */
> > +     return platform_driver_register(&aplic_driver);
> > +}
> > +core_initcall(aplic_init);
> > diff --git a/drivers/irqchip/irq-riscv-aplic-main.h b/drivers/irqchip/irq-riscv-aplic-main.h
> > new file mode 100644
> > index 000000000000..474a04229334
> > --- /dev/null
> > +++ b/drivers/irqchip/irq-riscv-aplic-main.h
> > @@ -0,0 +1,45 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only */
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +
> > +#ifndef _IRQ_RISCV_APLIC_MAIN_H
> > +#define _IRQ_RISCV_APLIC_MAIN_H
> > +
> > +#include <linux/device.h>
> > +#include <linux/io.h>
> > +#include <linux/irq.h>
> > +#include <linux/irqdomain.h>
> > +#include <linux/fwnode.h>
> > +
> > +#define APLIC_DEFAULT_PRIORITY               1
> > +
> > +struct aplic_msicfg {
> > +     phys_addr_t             base_ppn;
> > +     u32                     hhxs;
> > +     u32                     hhxw;
> > +     u32                     lhxs;
> > +     u32                     lhxw;
> > +};
> > +
> > +struct aplic_priv {
> > +     struct device           *dev;
> > +     u32                     gsi_base;
> > +     u32                     nr_irqs;
> > +     u32                     nr_idcs;
> > +     void __iomem            *regs;
> > +     struct aplic_msicfg     msicfg;
> > +};
> > +
> > +void aplic_irq_unmask(struct irq_data *d);
> > +void aplic_irq_mask(struct irq_data *d);
> > +int aplic_irq_set_type(struct irq_data *d, unsigned int type);
> > +int aplic_irqdomain_translate(struct irq_fwspec *fwspec, u32 gsi_base,
> > +                           unsigned long *hwirq, unsigned int *type);
> > +void aplic_init_hw_global(struct aplic_priv *priv, bool msi_mode);
> > +int aplic_setup_priv(struct aplic_priv *priv, struct device *dev,
> > +                  void __iomem *regs);
> > +int aplic_direct_setup(struct device *dev, void __iomem *regs);
> > +
> > +#endif
> > diff --git a/include/linux/irqchip/riscv-aplic.h b/include/linux/irqchip/riscv-aplic.h
> > new file mode 100644
> > index 000000000000..97e198ea0109
> > --- /dev/null
> > +++ b/include/linux/irqchip/riscv-aplic.h
> > @@ -0,0 +1,119 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only */
> > +/*
> > + * Copyright (C) 2021 Western Digital Corporation or its affiliates.
> > + * Copyright (C) 2022 Ventana Micro Systems Inc.
> > + */
> > +#ifndef __LINUX_IRQCHIP_RISCV_APLIC_H
> > +#define __LINUX_IRQCHIP_RISCV_APLIC_H
> > +
> > +#include <linux/bitops.h>
> > +
> > +#define APLIC_MAX_IDC                        BIT(14)
> > +#define APLIC_MAX_SOURCE             1024
> > +
> > +#define APLIC_DOMAINCFG                      0x0000
> > +#define APLIC_DOMAINCFG_RDONLY               0x80000000
> > +#define APLIC_DOMAINCFG_IE           BIT(8)
> > +#define APLIC_DOMAINCFG_DM           BIT(2)
> > +#define APLIC_DOMAINCFG_BE           BIT(0)
> > +
> > +#define APLIC_SOURCECFG_BASE         0x0004
> > +#define APLIC_SOURCECFG_D            BIT(10)
> > +#define APLIC_SOURCECFG_CHILDIDX_MASK        0x000003ff
> > +#define APLIC_SOURCECFG_SM_MASK      0x00000007
> > +#define APLIC_SOURCECFG_SM_INACTIVE  0x0
> > +#define APLIC_SOURCECFG_SM_DETACH    0x1
> > +#define APLIC_SOURCECFG_SM_EDGE_RISE 0x4
> > +#define APLIC_SOURCECFG_SM_EDGE_FALL 0x5
> > +#define APLIC_SOURCECFG_SM_LEVEL_HIGH        0x6
> > +#define APLIC_SOURCECFG_SM_LEVEL_LOW 0x7
> > +
> > +#define APLIC_MMSICFGADDR            0x1bc0
> > +#define APLIC_MMSICFGADDRH           0x1bc4
> > +#define APLIC_SMSICFGADDR            0x1bc8
> > +#define APLIC_SMSICFGADDRH           0x1bcc
> > +
> > +#ifdef CONFIG_RISCV_M_MODE
> > +#define APLIC_xMSICFGADDR            APLIC_MMSICFGADDR
> > +#define APLIC_xMSICFGADDRH           APLIC_MMSICFGADDRH
> > +#else
> > +#define APLIC_xMSICFGADDR            APLIC_SMSICFGADDR
> > +#define APLIC_xMSICFGADDRH           APLIC_SMSICFGADDRH
> > +#endif
> > +
> > +#define APLIC_xMSICFGADDRH_L         BIT(31)
> > +#define APLIC_xMSICFGADDRH_HHXS_MASK 0x1f
> > +#define APLIC_xMSICFGADDRH_HHXS_SHIFT        24
> > +#define APLIC_xMSICFGADDRH_LHXS_MASK 0x7
> > +#define APLIC_xMSICFGADDRH_LHXS_SHIFT        20
> > +#define APLIC_xMSICFGADDRH_HHXW_MASK 0x7
> > +#define APLIC_xMSICFGADDRH_HHXW_SHIFT        16
> > +#define APLIC_xMSICFGADDRH_LHXW_MASK 0xf
> > +#define APLIC_xMSICFGADDRH_LHXW_SHIFT        12
> > +#define APLIC_xMSICFGADDRH_BAPPN_MASK        0xfff
> > +
> > +#define APLIC_xMSICFGADDR_PPN_SHIFT  12
> > +
> > +#define APLIC_xMSICFGADDR_PPN_HART(__lhxs) \
> > +     (BIT(__lhxs) - 1)
> > +
> > +#define APLIC_xMSICFGADDR_PPN_LHX_MASK(__lhxw) \
> > +     (BIT(__lhxw) - 1)
> > +#define APLIC_xMSICFGADDR_PPN_LHX_SHIFT(__lhxs) \
> > +     ((__lhxs))
> > +#define APLIC_xMSICFGADDR_PPN_LHX(__lhxw, __lhxs) \
> > +     (APLIC_xMSICFGADDR_PPN_LHX_MASK(__lhxw) << \
> > +      APLIC_xMSICFGADDR_PPN_LHX_SHIFT(__lhxs))
> > +
> > +#define APLIC_xMSICFGADDR_PPN_HHX_MASK(__hhxw) \
> > +     (BIT(__hhxw) - 1)
> > +#define APLIC_xMSICFGADDR_PPN_HHX_SHIFT(__hhxs) \
> > +     ((__hhxs) + APLIC_xMSICFGADDR_PPN_SHIFT)
> > +#define APLIC_xMSICFGADDR_PPN_HHX(__hhxw, __hhxs) \
> > +     (APLIC_xMSICFGADDR_PPN_HHX_MASK(__hhxw) << \
> > +      APLIC_xMSICFGADDR_PPN_HHX_SHIFT(__hhxs))
> > +
> > +#define APLIC_IRQBITS_PER_REG                32
> > +
> > +#define APLIC_SETIP_BASE             0x1c00
> > +#define APLIC_SETIPNUM                       0x1cdc
> > +
> > +#define APLIC_CLRIP_BASE             0x1d00
> > +#define APLIC_CLRIPNUM                       0x1ddc
> > +
> > +#define APLIC_SETIE_BASE             0x1e00
> > +#define APLIC_SETIENUM                       0x1edc
> > +
> > +#define APLIC_CLRIE_BASE             0x1f00
> > +#define APLIC_CLRIENUM                       0x1fdc
> > +
> > +#define APLIC_SETIPNUM_LE            0x2000
> > +#define APLIC_SETIPNUM_BE            0x2004
> > +
> > +#define APLIC_GENMSI                 0x3000
> > +
> > +#define APLIC_TARGET_BASE            0x3004
> > +#define APLIC_TARGET_HART_IDX_SHIFT  18
> > +#define APLIC_TARGET_HART_IDX_MASK   0x3fff
> > +#define APLIC_TARGET_GUEST_IDX_SHIFT 12
> > +#define APLIC_TARGET_GUEST_IDX_MASK  0x3f
> > +#define APLIC_TARGET_IPRIO_MASK      0xff
> > +#define APLIC_TARGET_EIID_MASK       0x7ff
> > +
> > +#define APLIC_IDC_BASE                       0x4000
> > +#define APLIC_IDC_SIZE                       32
> > +
> > +#define APLIC_IDC_IDELIVERY          0x00
> > +
> > +#define APLIC_IDC_IFORCE             0x04
> > +
> > +#define APLIC_IDC_ITHRESHOLD         0x08
> > +
> > +#define APLIC_IDC_TOPI                       0x18
> > +#define APLIC_IDC_TOPI_ID_SHIFT      16
> > +#define APLIC_IDC_TOPI_ID_MASK       0x3ff
> > +#define APLIC_IDC_TOPI_PRIO_MASK     0xff
> > +
> > +#define APLIC_IDC_CLAIMI             0x1c
> > +
> > +#endif
> > --
> > 2.34.1
> >

Regards,
Anup

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