[PATCH v3 0/7] Raspberry Pi 4 PCIe support

[PATCH v3 0/7] Raspberry Pi 4 PCIe support

[Nicolas Saenz Julienne]

This series aims at providing support for Raspberry Pi 4's PCIe
controller, which is also shared with the Broadcom STB family of
devices.

There was a previous attempt to upstream this some years ago[1] but was
blocked as most STB PCIe integrations have a sparse DMA mapping[2] which
is something currently not supported by the kernel.  Luckily this is not
the case for the Raspberry Pi 4.

Note that the driver code is to be based on top of Rob Herring's series
simplifying inbound and outbound range parsing.

[1] https://patchwork.kernel.org/cover/10605933/
[2] https://patchwork.kernel.org/patch/10605957/

---

Changes since v2:
  - Redo register access in driver avoiding indirection while keeping
    the naming intact
  - Add patch editing ARM64's config
  - Last MSI cleanups, notably removing MSIX flag
  - Got rid of all _RB writes
  - Got rid of all of_data
  - Overall churn removal
  - Address the rest of Andrew's comments

Changes since v1:
  - add generic rounddown/roundup_pow_two64() patch
  - Add MAINTAINERS patch
  - Fix Kconfig
  - Cleanup probe, use up to date APIs, exit on MSI failure
  - Get rid of linux,pci-domain and other unused constructs
  - Use edge triggered setup for MSI
  - Cleanup MSI implementation
  - Fix multiple cosmetic issues
  - Remove supend/resume code

Jim Quinlan (3):
  dt-bindings: PCI: Add bindings for brcmstb's PCIe device
  PCI: brcmstb: add Broadcom STB PCIe host controller driver
  PCI: brcmstb: add MSI capability

Nicolas Saenz Julienne (4):
  linux/log2.h: Add roundup/rounddown_pow_two64() family of functions
  ARM: dts: bcm2711: Enable PCIe controller
  MAINTAINERS: Add brcmstb PCIe controller
  arm64: defconfig: Enable Broadcom's STB PCIe controller

 .../bindings/pci/brcm,stb-pcie.yaml           |   97 ++
 MAINTAINERS                                   |    4 +
 arch/arm/boot/dts/bcm2711.dtsi                |   41 +
 arch/arm64/configs/defconfig                  |    1 +
 drivers/acpi/arm64/iort.c                     |    2 +-
 drivers/net/ethernet/mellanox/mlx4/en_clock.c |    3 +-
 drivers/of/device.c                           |    2 +-
 drivers/pci/controller/Kconfig                |    9 +
 drivers/pci/controller/Makefile               |    1 +
 .../pci/controller/cadence/pcie-cadence-ep.c  |    7 +-
 drivers/pci/controller/cadence/pcie-cadence.c |    7 +-
 drivers/pci/controller/pcie-brcmstb.c         | 1012 +++++++++++++++++
 drivers/pci/controller/pcie-rockchip-ep.c     |    9 +-
 include/linux/log2.h                          |   52 +
 kernel/dma/direct.c                           |    3 +-
 15 files changed, 1230 insertions(+), 20 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml
 create mode 100644 drivers/pci/controller/pcie-brcmstb.c

-- 
2.24.0


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[PATCH v3 1/7] linux/log2.h: Add roundup/rounddown_pow_two64() family of functions

[Nicolas Saenz Julienne]

Some users need to make sure their rounding function accepts and returns
64bit long variables regardless of the architecture. Sadly
roundup/rounddown_pow_two() takes and returns unsigned longs. Create a
new generic 64bit variant of the function and cleanup rougue custom
implementations.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>

---

Changes since v2:
  - Use u64
  - Rename function to roundup/down_pow_two_u64()
  - Use 1ULL instead of 1UL
  - Include function usage in of/device.c and acpi/arm64/iort.c

 drivers/acpi/arm64/iort.c                     |  2 +-
 drivers/net/ethernet/mellanox/mlx4/en_clock.c |  3 +-
 drivers/of/device.c                           |  2 +-
 .../pci/controller/cadence/pcie-cadence-ep.c  |  7 +--
 drivers/pci/controller/cadence/pcie-cadence.c |  7 +--
 drivers/pci/controller/pcie-rockchip-ep.c     |  9 ++--
 include/linux/log2.h                          | 52 +++++++++++++++++++
 kernel/dma/direct.c                           |  3 +-
 8 files changed, 65 insertions(+), 20 deletions(-)

diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index 33f71983e001..4809d3757d71 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -1090,7 +1090,7 @@ void iort_dma_setup(struct device *dev, u64 *dma_addr, u64 *dma_size)
 		 * firmware.
 		 */
 		end = dmaaddr + size - 1;
-		mask = DMA_BIT_MASK(ilog2(end) + 1);
+		mask = roundup_pow_of_two_u64(end) - 1;
 		dev->bus_dma_limit = end;
 		dev->coherent_dma_mask = mask;
 		*dev->dma_mask = mask;
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_clock.c b/drivers/net/ethernet/mellanox/mlx4/en_clock.c
index 024788549c25..ba5368e221f3 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_clock.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_clock.c
@@ -33,6 +33,7 @@
 
 #include <linux/mlx4/device.h>
 #include <linux/clocksource.h>
+#include <linux/log2.h>
 
 #include "mlx4_en.h"
 
@@ -252,7 +253,7 @@ static u32 freq_to_shift(u16 freq)
 {
 	u32 freq_khz = freq * 1000;
 	u64 max_val_cycles = freq_khz * 1000 * MLX4_EN_WRAP_AROUND_SEC;
-	u64 max_val_cycles_rounded = 1ULL << fls64(max_val_cycles - 1);
+	u64 max_val_cycles_rounded = roundup_pow_of_two_u64(max_val_cycles);
 	/* calculate max possible multiplier in order to fit in 64bit */
 	u64 max_mul = div64_u64(ULLONG_MAX, max_val_cycles_rounded);
 
diff --git a/drivers/of/device.c b/drivers/of/device.c
index e9127db7b067..418d7d014af1 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -149,7 +149,7 @@ int of_dma_configure(struct device *dev, struct device_node *np, bool force_dma)
 	 * set by the driver.
 	 */
 	end = dma_addr + size - 1;
-	mask = DMA_BIT_MASK(ilog2(end) + 1);
+	mask = roundup_pow_of_two_u64(end) - 1;
 	dev->coherent_dma_mask &= mask;
 	*dev->dma_mask &= mask;
 	/* ...but only set bus limit if we found valid dma-ranges earlier */
diff --git a/drivers/pci/controller/cadence/pcie-cadence-ep.c b/drivers/pci/controller/cadence/pcie-cadence-ep.c
index 1c173dad67d1..f6e37eb67c68 100644
--- a/drivers/pci/controller/cadence/pcie-cadence-ep.c
+++ b/drivers/pci/controller/cadence/pcie-cadence-ep.c
@@ -10,6 +10,7 @@
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/sizes.h>
+#include <linux/log2.h>
 
 #include "pcie-cadence.h"
 
@@ -61,11 +62,7 @@ static int cdns_pcie_ep_set_bar(struct pci_epc *epc, u8 fn,
 
 	/* BAR size is 2^(aperture + 7) */
 	sz = max_t(size_t, epf_bar->size, CDNS_PCIE_EP_MIN_APERTURE);
-	/*
-	 * roundup_pow_of_two() returns an unsigned long, which is not suited
-	 * for 64bit values.
-	 */
-	sz = 1ULL << fls64(sz - 1);
+	sz = roundup_pow_of_two_u64(sz);
 	aperture = ilog2(sz) - 7; /* 128B -> 0, 256B -> 1, 512B -> 2, ... */
 
 	if ((flags & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_IO) {
diff --git a/drivers/pci/controller/cadence/pcie-cadence.c b/drivers/pci/controller/cadence/pcie-cadence.c
index cd795f6fc1e2..2ddda5ac60c4 100644
--- a/drivers/pci/controller/cadence/pcie-cadence.c
+++ b/drivers/pci/controller/cadence/pcie-cadence.c
@@ -4,6 +4,7 @@
 // Author: Cyrille Pitchen <cyrille.pitchen@free-electrons.com>
 
 #include <linux/kernel.h>
+#include <linux/log2.h>
 
 #include "pcie-cadence.h"
 
@@ -11,11 +12,7 @@ void cdns_pcie_set_outbound_region(struct cdns_pcie *pcie, u8 fn,
 				   u32 r, bool is_io,
 				   u64 cpu_addr, u64 pci_addr, size_t size)
 {
-	/*
-	 * roundup_pow_of_two() returns an unsigned long, which is not suited
-	 * for 64bit values.
-	 */
-	u64 sz = 1ULL << fls64(size - 1);
+	u64 sz = roundup_pow_of_two_u64(size);
 	int nbits = ilog2(sz);
 	u32 addr0, addr1, desc0, desc1;
 
diff --git a/drivers/pci/controller/pcie-rockchip-ep.c b/drivers/pci/controller/pcie-rockchip-ep.c
index d743b0a48988..343f9683b540 100644
--- a/drivers/pci/controller/pcie-rockchip-ep.c
+++ b/drivers/pci/controller/pcie-rockchip-ep.c
@@ -16,6 +16,7 @@
 #include <linux/platform_device.h>
 #include <linux/pci-epf.h>
 #include <linux/sizes.h>
+#include <linux/log2.h>
 
 #include "pcie-rockchip.h"
 
@@ -70,7 +71,7 @@ static void rockchip_pcie_prog_ep_ob_atu(struct rockchip_pcie *rockchip, u8 fn,
 					 u32 r, u32 type, u64 cpu_addr,
 					 u64 pci_addr, size_t size)
 {
-	u64 sz = 1ULL << fls64(size - 1);
+	u64 sz = roundup_pow_of_two_u64(size);
 	int num_pass_bits = ilog2(sz);
 	u32 addr0, addr1, desc0, desc1;
 	bool is_nor_msg = (type == AXI_WRAPPER_NOR_MSG);
@@ -172,11 +173,7 @@ static int rockchip_pcie_ep_set_bar(struct pci_epc *epc, u8 fn,
 	/* BAR size is 2^(aperture + 7) */
 	sz = max_t(size_t, epf_bar->size, MIN_EP_APERTURE);
 
-	/*
-	 * roundup_pow_of_two() returns an unsigned long, which is not suited
-	 * for 64bit values.
-	 */
-	sz = 1ULL << fls64(sz - 1);
+	sz = roundup_pow_of_two_u64(sz);
 	aperture = ilog2(sz) - 7; /* 128B -> 0, 256B -> 1, 512B -> 2, ... */
 
 	if ((flags & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_IO) {
diff --git a/include/linux/log2.h b/include/linux/log2.h
index 83a4a3ca3e8a..0db47b78faa2 100644
--- a/include/linux/log2.h
+++ b/include/linux/log2.h
@@ -67,6 +67,24 @@ unsigned long __rounddown_pow_of_two(unsigned long n)
 	return 1UL << (fls_long(n) - 1);
 }
 
+/**
+ * __roundup_pow_of_two_u64() - round 64bit value up to nearest power of two
+ * @n: value to round up
+ */
+static inline __attribute__((const)) u64 __roundup_pow_of_two_u64(u64 n)
+{
+	return 1ULL << fls64(n - 1);
+}
+
+/**
+ * __rounddown_pow_of_two_u64() - round 64bit value down to nearest power of two
+ * @n: value to round down
+ */
+static inline __attribute__((const)) u64 __rounddown_pow_of_two_u64(u64 n)
+{
+	return 1ULL << (fls64(n) - 1);
+}
+
 /**
  * const_ilog2 - log base 2 of 32-bit or a 64-bit constant unsigned value
  * @n: parameter
@@ -194,6 +212,40 @@ unsigned long __rounddown_pow_of_two(unsigned long n)
 	__rounddown_pow_of_two(n)		\
  )
 
+/**
+ * roundup_pow_of_two_u64 - round the given 64bit value up to nearest power of
+ * two
+ * @n: parameter
+ *
+ * round the given value up to the nearest power of two
+ * - the result is undefined when n == 0
+ * - this can be used to initialise global variables from constant data
+ */
+#define roundup_pow_of_two_u64(n)			\
+(						\
+	__builtin_constant_p(n) ? (		\
+		(n == 1) ? 1 :			\
+		(1UL << (ilog2((n) - 1) + 1))	\
+				   ) :		\
+	__roundup_pow_of_two_u64(n)		\
+)
+
+/**
+ * rounddown_pow_of_two_u64 - round the given 64bit value down to nearest power
+ * of two
+ * @n: parameter
+ *
+ * round the given value down to the nearest power of two
+ * - the result is undefined when n == 0
+ * - this can be used to initialise global variables from constant data
+ */
+#define rounddown_pow_of_two_u64(n)		\
+(						\
+	__builtin_constant_p(n) ? (		\
+		(1UL << ilog2(n))) :		\
+	__rounddown_pow_of_two_u64(n)		\
+)
+
 static inline __attribute_const__
 int __order_base_2(unsigned long n)
 {
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 6af7ae83c4ad..8dd59e51b4dc 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -15,6 +15,7 @@
 #include <linux/vmalloc.h>
 #include <linux/set_memory.h>
 #include <linux/swiotlb.h>
+#include <linux/log2.h>
 
 /*
  * Most architectures use ZONE_DMA for the first 16 Megabytes, but some use it
@@ -53,7 +54,7 @@ u64 dma_direct_get_required_mask(struct device *dev)
 {
 	u64 max_dma = phys_to_dma_direct(dev, (max_pfn - 1) << PAGE_SHIFT);
 
-	return (1ULL << (fls64(max_dma) - 1)) * 2 - 1;
+	return rounddown_pow_of_two_u64(max_dma) * 2 - 1;
 }
 
 static gfp_t __dma_direct_optimal_gfp_mask(struct device *dev, u64 dma_mask,
-- 
2.24.0


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[PATCH v3 2/7] dt-bindings: PCI: Add bindings for brcmstb's PCIe device

[Nicolas Saenz Julienne]

From: Jim Quinlan <james.quinlan@broadcom.com>

The DT bindings description of the brcmstb PCIe device is described.
This node can only be used for now on the Raspberry Pi 4.

Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>
Co-developed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>

---

Changes since v2:
  - Add pci reference schema
  - Drop all default properties
  - Assume msi-controller and msi-parent are properly defined
  - Add num entries on multiple properties
  - use unevaluatedProperties
  - Update required properties
  - Fix license

Changes since v1:
  - Fix commit Subject
  - Remove linux,pci-domain

This was based on Jim's original submission[1], converted to yaml and
adapted to the RPi4 case.

[1] https://patchwork.kernel.org/patch/10605937/

 .../bindings/pci/brcm,stb-pcie.yaml           | 97 +++++++++++++++++++
 1 file changed, 97 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml

diff --git a/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml b/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml
new file mode 100644
index 000000000000..77d3e81a437b
--- /dev/null
+++ b/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml
@@ -0,0 +1,97 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pci/brcm,stb-pcie.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Brcmstb PCIe Host Controller Device Tree Bindings
+
+maintainers:
+  - Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
+
+allOf:
+  - $ref: /schemas/pci/pci-bus.yaml#
+
+properties:
+  compatible:
+    const: brcm,bcm2711-pcie # The Raspberry Pi 4
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    minItems: 1
+    maxItems: 2
+    items:
+      - description: PCIe host controller
+      - description: builtin MSI controller
+
+  interrupt-names:
+    minItems: 1
+    maxItems: 2
+    items:
+      - const: pcie
+      - const: msi
+
+  ranges:
+    maxItems: 1
+
+  dma-ranges:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    items:
+      - const: sw_pcie
+
+  msi-controller:
+    description: Identifies the node as an MSI controller.
+
+  msi-parent:
+    description: MSI controller the device is capable of using.
+
+  brcm,enable-ssc:
+    description: Indicates usage of spread-spectrum clocking.
+    type: boolean
+
+required:
+  - reg
+  - dma-ranges
+  - "#interrupt-cells"
+  - interrupts
+  - interrupt-names
+  - interrupt-map-mask
+  - interrupt-map
+  - msi-controller
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+    scb {
+            #address-cells = <2>;
+            #size-cells = <1>;
+            pcie0: pcie@7d500000 {
+                    compatible = "brcm,bcm2711-pcie";
+                    reg = <0x0 0x7d500000 0x9310>;
+                    device_type = "pci";
+                    #address-cells = <3>;
+                    #size-cells = <2>;
+                    #interrupt-cells = <1>;
+                    interrupts = <GIC_SPI 148 IRQ_TYPE_LEVEL_HIGH>,
+                                 <GIC_SPI 148 IRQ_TYPE_LEVEL_HIGH>;
+                    interrupt-names = "pcie", "msi";
+                    interrupt-map-mask = <0x0 0x0 0x0 0x7>;
+                    interrupt-map = <0 0 0 1 &gicv2 GIC_SPI 143 IRQ_TYPE_LEVEL_HIGH>;
+                    msi-parent = <&pcie0>;
+                    msi-controller;
+                    ranges = <0x02000000 0x0 0xf8000000 0x6 0x00000000 0x0 0x04000000>;
+                    dma-ranges = <0x02000000 0x0 0x00000000 0x0 0x00000000 0x0 0x80000000>;
+                    brcm,enable-ssc;
+            };
+    };
-- 
2.24.0


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[PATCH v3 3/7] ARM: dts: bcm2711: Enable PCIe controller

[Nicolas Saenz Julienne]

This enables bcm2711's PCIe bus, which is hardwired to a VIA
Technologies XHCI USB 3.0 controller.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>

---

This will likely need a rebase once the RPi GENET patches land.

Changes since v2:
  - Remove unused interrupt-map
  - correct dma-ranges to it's full size, non power of 2 bus DMA
    constraints now supported in linux-next[1]
  - add device_type
  - rename alias from pcie_0 to pcie0

Changes since v1:
  - remove linux,pci-domain

[1] https://lkml.org/lkml/2019/11/21/235

 arch/arm/boot/dts/bcm2711.dtsi | 41 ++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/arch/arm/boot/dts/bcm2711.dtsi b/arch/arm/boot/dts/bcm2711.dtsi
index 667658497898..2e121fc8b3d0 100644
--- a/arch/arm/boot/dts/bcm2711.dtsi
+++ b/arch/arm/boot/dts/bcm2711.dtsi
@@ -288,6 +288,47 @@ IRQ_TYPE_LEVEL_LOW)>,
 		arm,cpu-registers-not-fw-configured;
 	};
 
+	scb {
+		compatible = "simple-bus";
+		#address-cells = <2>;
+		#size-cells = <1>;
+
+		ranges = <0x0 0x7c000000  0x0 0xfc000000  0x03800000>,
+			 <0x6 0x00000000  0x6 0x00000000  0x40000000>;
+
+		pcie0: pcie@7d500000 {
+			compatible = "brcm,bcm2711-pcie";
+			reg = <0x0 0x7d500000 0x9310>;
+			device_type = "pci";
+			#address-cells = <3>;
+			#interrupt-cells = <1>;
+			#size-cells = <2>;
+			interrupts = <GIC_SPI 148 IRQ_TYPE_LEVEL_HIGH>,
+				     <GIC_SPI 148 IRQ_TYPE_LEVEL_HIGH>;
+			interrupt-names = "pcie", "msi";
+			interrupt-map-mask = <0x0 0x0 0x0 0x7>;
+			interrupt-map = <0 0 0 1 &gicv2 GIC_SPI 143
+							IRQ_TYPE_LEVEL_HIGH>;
+			msi-controller;
+			msi-parent = <&pcie0>;
+
+			ranges = <0x02000000 0x0 0xf8000000 0x6 0x00000000
+				  0x0 0x04000000>;
+			/*
+			 * The wrapper around the PCIe block has a bug
+			 * preventing it from accessing beyond the first 3GB of
+			 * memory. As the bus DMA mask is rounded up to the
+			 * closest power of two of the dma-range size, we're
+			 * forced to set the limit at 2GB. This can be
+			 * harmlessly changed in the future once the DMA code
+			 * handles non power of two DMA limits.
+			 */
+			dma-ranges = <0x02000000 0x0 0x00000000 0x0 0x00000000
+				      0x0 0xc0000000>;
+			brcm,enable-ssc;
+		};
+	};
+
 	cpus: cpus {
 		#address-cells = <1>;
 		#size-cells = <0>;
-- 
2.24.0


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[PATCH v3 4/7] PCI: brcmstb: add Broadcom STB PCIe host controller driver

[Nicolas Saenz Julienne]

From: Jim Quinlan <james.quinlan@broadcom.com>

This adds a basic driver for Broadcom's STB PCIe controller, for now
aimed at Raspberry Pi 4's SoC, bcm2711.

Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>
Co-developed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>

---

Changes since v2:
  - Correct rc_bar2_offset sign
  - Invert IRQ clear and masking in setup code
  - Use bitfield.h, redo all register ops while keeping the register
    names intact
  - Remove all SHIFT register definitions
  - Get rid of all _RB writes
  - Get rid of of_data
  - Don't iterate over inexisting dma-ranges
  - Add comment regarding dma-ranges validation
  - Small cosmetic cleanups
  - Fix license mismatch
  - Set driver Kconfig tristate
  - Didn't add any comment about the controller not being I/O coherent
    for now as I wait for Jeremy's reply

Changes since v1:
  - Fix Kconfig
  - Remove pci domain check
  - Remove all MSI related code
  - Remove supend/resume code
  - Simplify link state wait routine
  - Prefix all functions
  - Use of_device_get_match_data()
  - Use devm_clk_get_optional()
  - Get rid of irq variable
  - Use STB all over the driver
  - Simplify map_bus() function
  - Fix license mismatch
  - Remove unused register definitions
  - Small cleanups, spell errors

This is based on Jim's original submission[1] but adapted and tailored
specifically to bcm2711's needs (that's the Raspberry Pi 4). Support for
the rest of the brcmstb family will soon follow once we get support for
multiple dma-ranges in dma/direct.

[1] https://patchwork.kernel.org/patch/10605959/

 drivers/pci/controller/Kconfig        |   8 +
 drivers/pci/controller/Makefile       |   1 +
 drivers/pci/controller/pcie-brcmstb.c | 753 ++++++++++++++++++++++++++
 3 files changed, 762 insertions(+)
 create mode 100644 drivers/pci/controller/pcie-brcmstb.c

diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig
index c77069c8ee5d..27504f108ee5 100644
--- a/drivers/pci/controller/Kconfig
+++ b/drivers/pci/controller/Kconfig
@@ -253,6 +253,14 @@ config VMD
 	  To compile this driver as a module, choose M here: the
 	  module will be called vmd.
 
+config PCIE_BRCMSTB
+	tristate "Broadcom Brcmstb PCIe host controller"
+	depends on ARCH_BCM2835 || COMPILE_TEST
+	depends on OF
+	help
+	  Say Y here to enable PCIe host controller support for
+	  Broadcom STB based SoCs, like the Raspberry Pi 4.
+
 config PCI_HYPERV_INTERFACE
 	tristate "Hyper-V PCI Interface"
 	depends on X86 && HYPERV && PCI_MSI && PCI_MSI_IRQ_DOMAIN && X86_64
diff --git a/drivers/pci/controller/Makefile b/drivers/pci/controller/Makefile
index 3d4f597f15ce..01b2502a5323 100644
--- a/drivers/pci/controller/Makefile
+++ b/drivers/pci/controller/Makefile
@@ -28,6 +28,7 @@ obj-$(CONFIG_PCIE_MEDIATEK) += pcie-mediatek.o
 obj-$(CONFIG_PCIE_MOBIVEIL) += pcie-mobiveil.o
 obj-$(CONFIG_PCIE_TANGO_SMP8759) += pcie-tango.o
 obj-$(CONFIG_VMD) += vmd.o
+obj-$(CONFIG_PCIE_BRCMSTB) += pcie-brcmstb.o
 # pcie-hisi.o quirks are needed even without CONFIG_PCIE_DW
 obj-y				+= dwc/
 
diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
new file mode 100644
index 000000000000..28c1b9429d3d
--- /dev/null
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -0,0 +1,753 @@
+// SPDX-License-Identifier: GPL-2.0+
+/* Copyright (C) 2009 - 2019 Broadcom */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/compiler.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/log2.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_pci.h>
+#include <linux/of_platform.h>
+#include <linux/pci.h>
+#include <linux/printk.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/types.h>
+
+#include "../pci.h"
+
+/* BRCM_PCIE_CAP_REGS - Offset for the mandatory capability config regs */
+#define BRCM_PCIE_CAP_REGS				0x00ac
+
+/*
+ * Broadcom STB PCIe Register Offsets. The names are from the chip's RDB and we
+ * use them here so that a script can correlate this code and the RDB to
+ * prevent discrepancies.
+ */
+#define PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1				0x0188
+#define  PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1_ENDIAN_MODE_BAR2_MASK	0xc
+#define  PCIE_RC_CFG_VENDOR_SPCIFIC_REG1_LITTLE_ENDIAN			0x0
+
+#define PCIE_RC_CFG_PRIV1_ID_VAL3			0x043c
+#define  PCIE_RC_CFG_PRIV1_ID_VAL3_CLASS_CODE_MASK	0xffffff
+
+#define PCIE_RC_DL_MDIO_ADDR				0x1100
+#define PCIE_RC_DL_MDIO_WR_DATA				0x1104
+#define PCIE_RC_DL_MDIO_RD_DATA				0x1108
+
+#define PCIE_MISC_MISC_CTRL				0x4008
+#define  PCIE_MISC_MISC_CTRL_SCB_ACCESS_EN_MASK		0x1000
+#define  PCIE_MISC_MISC_CTRL_CFG_READ_UR_MODE_MASK	0x2000
+#define  PCIE_MISC_MISC_CTRL_MAX_BURST_SIZE_MASK	0x300000
+#define  PCIE_MISC_MISC_CTRL_MAX_BURST_SIZE_128		0x0
+#define  PCIE_MISC_MISC_CTRL_SCB0_SIZE_MASK		0xf8000000
+
+#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LO		0x400c
+#define PCIE_MEM_WIN0_LO(win)	\
+		PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LO + ((win) * 4)
+
+#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_HI		0x4010
+#define PCIE_MEM_WIN0_HI(win)	\
+		PCIE_MISC_CPU_2_PCIE_MEM_WIN0_HI + ((win) * 4)
+
+#define PCIE_MISC_RC_BAR1_CONFIG_LO			0x402c
+#define  PCIE_MISC_RC_BAR1_CONFIG_LO_SIZE_MASK		0x1f
+
+#define PCIE_MISC_RC_BAR2_CONFIG_LO			0x4034
+#define  PCIE_MISC_RC_BAR2_CONFIG_LO_SIZE_MASK		0x1f
+#define PCIE_MISC_RC_BAR2_CONFIG_HI			0x4038
+
+#define PCIE_MISC_RC_BAR3_CONFIG_LO			0x403c
+#define  PCIE_MISC_RC_BAR3_CONFIG_LO_SIZE_MASK		0x1f
+
+#define PCIE_MISC_PCIE_CTRL				0x4064
+#define  PCIE_MISC_PCIE_CTRL_PCIE_L23_REQUEST_MASK	0x1
+
+#define PCIE_MISC_PCIE_STATUS				0x4068
+#define  PCIE_MISC_PCIE_STATUS_PCIE_PORT_MASK		0x80
+#define  PCIE_MISC_PCIE_STATUS_PCIE_DL_ACTIVE_MASK	0x20
+#define  PCIE_MISC_PCIE_STATUS_PCIE_PHYLINKUP_MASK	0x10
+#define  PCIE_MISC_PCIE_STATUS_PCIE_LINK_IN_L23_MASK	0x40
+
+#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT		0x4070
+#define  PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_LIMIT_MASK	0xfff00000
+#define  PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_BASE_MASK	0xfff0
+#define PCIE_MEM_WIN0_BASE_LIMIT(win)	\
+		PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT + ((win) * 4)
+
+#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_HI			0x4080
+#define  PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_HI_BASE_MASK	0xff
+#define PCIE_MEM_WIN0_BASE_HI(win)	\
+		PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_HI + ((win) * 8)
+
+#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LIMIT_HI			0x4084
+#define  PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LIMIT_HI_LIMIT_MASK	0xff
+#define PCIE_MEM_WIN0_LIMIT_HI(win)	\
+		PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LIMIT_HI + ((win) * 8)
+
+#define PCIE_MISC_HARD_PCIE_HARD_DEBUG					0x4204
+#define  PCIE_MISC_HARD_PCIE_HARD_DEBUG_CLKREQ_DEBUG_ENABLE_MASK	0x2
+#define  PCIE_MISC_HARD_PCIE_HARD_DEBUG_SERDES_IDDQ_MASK		0x08000000
+
+#define PCIE_MSI_INTR2_STATUS				0x4500
+#define PCIE_MSI_INTR2_CLR				0x4508
+#define PCIE_MSI_INTR2_MASK_SET				0x4510
+#define PCIE_MSI_INTR2_MASK_CLR				0x4514
+
+#define PCIE_EXT_CFG_DATA				0x8000
+
+#define PCIE_EXT_CFG_INDEX				0x9000
+#define  PCIE_EXT_BUSNUM_SHIFT				20
+#define  PCIE_EXT_SLOT_SHIFT				15
+#define  PCIE_EXT_FUNC_SHIFT				12
+
+#define PCIE_RGR1_SW_INIT_1				0x9210
+#define  PCIE_RGR1_SW_INIT_1_PERST_MASK			0x1
+#define  PCIE_RGR1_SW_INIT_1_INIT_MASK			0x2
+
+/* PCIe parameters */
+#define BRCM_NUM_PCIE_OUT_WINS		0x4
+
+/* MDIO registers */
+#define MDIO_PORT0			0x0
+#define MDIO_DATA_MASK			0x7fffffff
+#define MDIO_PORT_MASK			0xf0000
+#define MDIO_REGAD_MASK			0xffff
+#define MDIO_CMD_MASK			0xfff00000
+#define MDIO_CMD_READ			0x1
+#define MDIO_CMD_WRITE			0x0
+#define MDIO_DATA_DONE_MASK		0x80000000
+#define MDIO_RD_DONE(x)			(((x) & MDIO_DATA_DONE_MASK) ? 1 : 0)
+#define MDIO_WT_DONE(x)			(((x) & MDIO_DATA_DONE_MASK) ? 0 : 1)
+#define SSC_REGS_ADDR			0x1100
+#define SET_ADDR_OFFSET			0x1f
+#define SSC_CNTL_OFFSET			0x2
+#define SSC_CNTL_OVRD_EN_MASK		0x8000
+#define SSC_CNTL_OVRD_VAL_MASK		0x4000
+#define SSC_STATUS_OFFSET		0x1
+#define SSC_STATUS_SSC_MASK		0x400
+#define SSC_STATUS_PLL_LOCK_MASK	0x800
+
+/* Internal PCIe Host Controller Information.*/
+struct brcm_pcie {
+	struct device		*dev;
+	void __iomem		*base;
+	struct clk		*clk;
+	struct pci_bus		*root_bus;
+	struct device_node	*np;
+	bool			ssc;
+	int			gen;
+};
+
+/*
+ * This is to convert the size of the inbound "BAR" region to the
+ * non-linear values of PCIE_X_MISC_RC_BAR[123]_CONFIG_LO.SIZE
+ */
+static int brcm_pcie_encode_ibar_size(u64 size)
+{
+	int log2_in = ilog2(size);
+
+	if (log2_in >= 12 && log2_in <= 15)
+		/* Covers 4KB to 32KB (inclusive) */
+		return (log2_in - 12) + 0x1c;
+	else if (log2_in >= 16 && log2_in <= 35)
+		/* Covers 64KB to 32GB, (inclusive) */
+		return log2_in - 15;
+	/* Something is awry so disable */
+	return 0;
+}
+
+static u32 brcm_pcie_mdio_form_pkt(int port, int regad, int cmd)
+{
+	u32 pkt = 0;
+
+	pkt |= FIELD_PREP(MDIO_PORT_MASK, port);
+	pkt |= FIELD_PREP(MDIO_REGAD_MASK, regad);
+	pkt |= FIELD_PREP(MDIO_CMD_MASK, cmd);
+
+	return pkt;
+}
+
+/* negative return value indicates error */
+static int brcm_pcie_mdio_read(void __iomem *base, u8 port, u8 regad, u32 *val)
+{
+	int tries;
+	u32 data;
+
+	writel(brcm_pcie_mdio_form_pkt(port, regad, MDIO_CMD_READ),
+		   base + PCIE_RC_DL_MDIO_ADDR);
+	readl(base + PCIE_RC_DL_MDIO_ADDR);
+
+	data = readl(base + PCIE_RC_DL_MDIO_RD_DATA);
+	for (tries = 0; !MDIO_RD_DONE(data) && tries < 10; tries++) {
+		udelay(10);
+		data = readl(base + PCIE_RC_DL_MDIO_RD_DATA);
+	}
+
+	*val = FIELD_GET(MDIO_DATA_MASK, data);
+	return MDIO_RD_DONE(data) ? 0 : -EIO;
+}
+
+/* negative return value indicates error */
+static int brcm_pcie_mdio_write(void __iomem *base, u8 port,
+				u8 regad, u16 wrdata)
+{
+	int tries;
+	u32 data;
+
+	writel(brcm_pcie_mdio_form_pkt(port, regad, MDIO_CMD_WRITE),
+		   base + PCIE_RC_DL_MDIO_ADDR);
+	readl(base + PCIE_RC_DL_MDIO_ADDR);
+	writel(MDIO_DATA_DONE_MASK | wrdata, base + PCIE_RC_DL_MDIO_WR_DATA);
+
+	data = readl(base + PCIE_RC_DL_MDIO_WR_DATA);
+	for (tries = 0; !MDIO_WT_DONE(data) && tries < 10; tries++) {
+		udelay(10);
+		data = readl(base + PCIE_RC_DL_MDIO_WR_DATA);
+	}
+
+	return MDIO_WT_DONE(data) ? 0 : -EIO;
+}
+
+/*
+ * Configures device for Spread Spectrum Clocking (SSC) mode; a negative
+ * return value indicates error.
+ */
+static int brcm_pcie_set_ssc(struct brcm_pcie *pcie)
+{
+	int pll, ssc;
+	int ret;
+	u32 tmp;
+
+	ret = brcm_pcie_mdio_write(pcie->base, MDIO_PORT0, SET_ADDR_OFFSET,
+				   SSC_REGS_ADDR);
+	if (ret < 0)
+		return ret;
+
+	ret = brcm_pcie_mdio_read(pcie->base, MDIO_PORT0,
+				  SSC_CNTL_OFFSET, &tmp);
+	if (ret < 0)
+		return ret;
+
+	u32p_replace_bits(&tmp, 1, SSC_CNTL_OVRD_EN_MASK);
+	u32p_replace_bits(&tmp, 1, SSC_CNTL_OVRD_VAL_MASK);
+	ret = brcm_pcie_mdio_write(pcie->base, MDIO_PORT0,
+				   SSC_CNTL_OFFSET, tmp);
+	if (ret < 0)
+		return ret;
+
+	usleep_range(1000, 2000);
+	ret = brcm_pcie_mdio_read(pcie->base, MDIO_PORT0,
+				  SSC_STATUS_OFFSET, &tmp);
+	if (ret < 0)
+		return ret;
+
+	ssc = FIELD_GET(SSC_STATUS_SSC_MASK, tmp);
+	pll = FIELD_GET(SSC_STATUS_PLL_LOCK_MASK, tmp);
+
+	return ssc && pll ? 0 : -EIO;
+}
+
+/* Limits operation to a specific generation (1, 2, or 3) */
+static void brcm_pcie_set_gen(struct brcm_pcie *pcie, int gen)
+{
+	u16 lnkctl2 = readw(pcie->base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKCTL2);
+	u32 lnkcap = readl(pcie->base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKCAP);
+
+	lnkcap = (lnkcap & ~PCI_EXP_LNKCAP_SLS) | gen;
+	writel(lnkcap, pcie->base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKCAP);
+
+	lnkctl2 = (lnkctl2 & ~0xf) | gen;
+	writew(lnkctl2, pcie->base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKCTL2);
+}
+
+static void brcm_pcie_set_outbound_win(struct brcm_pcie *pcie,
+				       unsigned int win, u64 cpu_addr,
+				       u64 pcie_addr, u64 size)
+{
+	u32 cpu_addr_mb_high, limit_addr_mb_high;
+	phys_addr_t cpu_addr_mb, limit_addr_mb;
+	int high_addr_shift;
+	u32 tmp;
+
+	/* Set the base of the pcie_addr window */
+	writel(lower_32_bits(pcie_addr), pcie->base + PCIE_MEM_WIN0_LO(win));
+	writel(upper_32_bits(pcie_addr), pcie->base + PCIE_MEM_WIN0_HI(win));
+
+	/* Write the addr base & limit lower bits (in MBs) */
+	cpu_addr_mb = cpu_addr / SZ_1M;
+	limit_addr_mb = (cpu_addr + size - 1) / SZ_1M;
+
+	tmp = readl(pcie->base + PCIE_MEM_WIN0_BASE_LIMIT(win));
+	u32p_replace_bits(&tmp, cpu_addr_mb,
+			  PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_BASE_MASK);
+	u32p_replace_bits(&tmp, limit_addr_mb,
+			  PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_LIMIT_MASK);
+	writel(tmp, pcie->base + PCIE_MEM_WIN0_BASE_LIMIT(win));
+
+	/* Write the cpu & limit addr upper bits */
+	high_addr_shift =
+		HWEIGHT32(PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_BASE_MASK);
+
+	cpu_addr_mb_high = cpu_addr_mb >> high_addr_shift;
+	tmp = readl(pcie->base + PCIE_MEM_WIN0_BASE_HI(win));
+	u32p_replace_bits(&tmp, cpu_addr_mb_high,
+			  PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_HI_BASE_MASK);
+	writel(tmp, pcie->base + PCIE_MEM_WIN0_BASE_HI(win));
+
+	limit_addr_mb_high = limit_addr_mb >> high_addr_shift;
+	tmp = readl(pcie->base + PCIE_MEM_WIN0_LIMIT_HI(win));
+	u32p_replace_bits(&tmp, limit_addr_mb_high,
+			  PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LIMIT_HI_LIMIT_MASK);
+	writel(tmp, pcie->base + PCIE_MEM_WIN0_LIMIT_HI(win));
+}
+
+/* The controller is capable of serving in both RC and EP roles */
+static bool brcm_pcie_rc_mode(struct brcm_pcie *pcie)
+{
+	void __iomem *base = pcie->base;
+	u32 val = readl(base + PCIE_MISC_PCIE_STATUS);
+
+	return !!FIELD_GET(PCIE_MISC_PCIE_STATUS_PCIE_PORT_MASK, val);
+}
+
+static bool brcm_pcie_link_up(struct brcm_pcie *pcie)
+{
+	u32 val = readl(pcie->base + PCIE_MISC_PCIE_STATUS);
+	u32 dla = FIELD_GET(PCIE_MISC_PCIE_STATUS_PCIE_DL_ACTIVE_MASK, val);
+	u32 plu = FIELD_GET(PCIE_MISC_PCIE_STATUS_PCIE_PHYLINKUP_MASK, val);
+
+	return dla && plu;
+}
+
+/* Configuration space read/write support */
+static inline int brcm_pcie_cfg_index(int busnr, int devfn, int reg)
+{
+	return ((PCI_SLOT(devfn) & 0x1f) << PCIE_EXT_SLOT_SHIFT)
+		| ((PCI_FUNC(devfn) & 0x07) << PCIE_EXT_FUNC_SHIFT)
+		| (busnr << PCIE_EXT_BUSNUM_SHIFT)
+		| (reg & ~3);
+}
+
+static void __iomem *brcm_pcie_map_conf(struct pci_bus *bus, unsigned int devfn,
+					int where)
+{
+	struct brcm_pcie *pcie = bus->sysdata;
+	void __iomem *base = pcie->base;
+	int idx;
+
+	/* Accesses to the RC go right to the RC registers if slot==0 */
+	if (pci_is_root_bus(bus))
+		return PCI_SLOT(devfn) ? NULL : base + where;
+
+	/* For devices, write to the config space index register */
+	idx = brcm_pcie_cfg_index(bus->number, devfn, 0);
+	writel(idx, pcie->base + PCIE_EXT_CFG_INDEX);
+	return base + PCIE_EXT_CFG_DATA + where;
+}
+
+static struct pci_ops brcm_pcie_ops = {
+	.map_bus = brcm_pcie_map_conf,
+	.read = pci_generic_config_read,
+	.write = pci_generic_config_write,
+};
+
+static inline void brcm_pcie_bridge_sw_init_set(struct brcm_pcie *pcie, u32 val)
+{
+	u32 tmp;
+
+	tmp = readl(pcie->base + PCIE_RGR1_SW_INIT_1);
+	u32p_replace_bits(&tmp, val, PCIE_RGR1_SW_INIT_1_INIT_MASK);
+	writel(tmp, pcie->base + PCIE_RGR1_SW_INIT_1);
+}
+
+static inline void brcm_pcie_perst_set(struct brcm_pcie *pcie, u32 val)
+{
+	u32 tmp;
+
+	tmp = readl(pcie->base + PCIE_RGR1_SW_INIT_1);
+	u32p_replace_bits(&tmp, val, PCIE_RGR1_SW_INIT_1_PERST_MASK);
+	writel(tmp, pcie->base + PCIE_RGR1_SW_INIT_1);
+}
+
+static inline int brcm_pcie_get_rc_bar2_size_and_offset(struct brcm_pcie *pcie,
+							u64 *rc_bar2_size,
+							u64 *rc_bar2_offset)
+{
+	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
+	struct device *dev = pcie->dev;
+	struct resource_entry *entry;
+
+	entry = resource_list_first_type(&bridge->dma_ranges, IORESOURCE_MEM);
+	if (!entry)
+		return -ENODEV;
+
+	*rc_bar2_offset = -entry->offset;
+	*rc_bar2_size = roundup_pow_of_two_u64(entry->res->end -
+					       entry->res->start + 1);
+
+	/*
+	 * We validate the inbound memory view even though we should trust
+	 * whatever the device-tree provides. This is because of an HW issue on
+	 * early Raspberry Pi 4's revisions (bcm2711). It turns out its
+	 * firmware has to dynamically edit dma-ranges due to a bug on the
+	 * PCIe controller integration, which prohibits any access above the
+	 * lower 3GB of memory. Given this, we decided to keep the dma-ranges
+	 * in check, avoiding hard to debug device-tree related issues in the
+	 * future:
+	 *
+	 * The PCIe host controller by design must set the inbound viewport to
+	 * be a contiguous arrangement of all of the system's memory.  In
+	 * addition, its size mut be a power of two.  To further complicate
+	 * matters, the viewport must start on a pcie-address that is aligned
+	 * on a multiple of its size.  If a portion of the viewport does not
+	 * represent system memory -- e.g. 3GB of memory requires a 4GB
+	 * viewport -- we can map the outbound memory in or after 3GB and even
+	 * though the viewport will overlap the outbound memory the controller
+	 * will know to send outbound memory downstream and everything else
+	 * upstream.
+	 *
+	 * For example:
+	 *
+	 * - The best-case scenario, memory up to 3GB, is to place the inbound
+	 *   region in the first 4GB of pcie-space, as some legacy devices can
+	 *   only address 32bits. We would also like to put the MSI under 4GB
+	 *   as well, since some devices require a 32bit MSI target address.
+	 *
+	 * - If the system memory is 4GB or larger we cannot start the inbound
+	 *   region at location 0 (since we have to allow some space for
+	 *   outbound memory @ 3GB). So instead it will  start at the 1x
+	 *   multiple of its size
+	 */
+	if (!*rc_bar2_size || *rc_bar2_offset % *rc_bar2_size ||
+	    (*rc_bar2_offset < SZ_4G && *rc_bar2_offset > SZ_2G)) {
+		dev_err(dev, "Invalid rc_bar2_offset/size: size 0x%llx, off 0x%llx\n",
+			*rc_bar2_size, *rc_bar2_offset);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int brcm_pcie_setup(struct brcm_pcie *pcie)
+{
+	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
+	u64 rc_bar2_offset, rc_bar2_size;
+	void __iomem *base = pcie->base;
+	struct device *dev = pcie->dev;
+	struct resource_entry *entry;
+	unsigned int scb_size_val;
+	bool ssc_good = false;
+	struct resource *res;
+	int num_out_wins = 0;
+	u16 nlw, cls, lnksta;
+	int i, ret;
+	u32 tmp;
+
+	/* Reset the bridge */
+	brcm_pcie_bridge_sw_init_set(pcie, 1);
+
+	usleep_range(100, 200);
+
+	/* Take the bridge out of reset */
+	brcm_pcie_bridge_sw_init_set(pcie, 0);
+
+	tmp = readl(base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
+	tmp &= ~PCIE_MISC_HARD_PCIE_HARD_DEBUG_SERDES_IDDQ_MASK;
+	writel(tmp, base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
+	/* Wait for SerDes to be stable */
+	usleep_range(100, 200);
+
+	/* Set SCB_MAX_BURST_SIZE, CFG_READ_UR_MODE, SCB_ACCESS_EN */
+	u32p_replace_bits(&tmp, 1, PCIE_MISC_MISC_CTRL_SCB_ACCESS_EN_MASK);
+	u32p_replace_bits(&tmp, 1, PCIE_MISC_MISC_CTRL_CFG_READ_UR_MODE_MASK);
+	u32p_replace_bits(&tmp, PCIE_MISC_MISC_CTRL_MAX_BURST_SIZE_128,
+			  PCIE_MISC_MISC_CTRL_MAX_BURST_SIZE_MASK);
+	writel(tmp, base + PCIE_MISC_MISC_CTRL);
+
+	ret = brcm_pcie_get_rc_bar2_size_and_offset(pcie, &rc_bar2_size,
+						    &rc_bar2_offset);
+	if (ret)
+		return ret;
+
+	tmp = lower_32_bits(rc_bar2_offset);
+	u32p_replace_bits(&tmp, brcm_pcie_encode_ibar_size(rc_bar2_size),
+			  PCIE_MISC_RC_BAR2_CONFIG_LO_SIZE_MASK);
+	writel(tmp, base + PCIE_MISC_RC_BAR2_CONFIG_LO);
+	writel(upper_32_bits(rc_bar2_offset),
+	       base + PCIE_MISC_RC_BAR2_CONFIG_HI);
+
+	scb_size_val = rc_bar2_size ?
+		       ilog2(rc_bar2_size) - 15 : 0xf; /* 0xf is 1GB */
+	tmp = readl(base + PCIE_MISC_MISC_CTRL);
+	u32p_replace_bits(&tmp, scb_size_val,
+			  PCIE_MISC_MISC_CTRL_SCB0_SIZE_MASK);
+	writel(tmp, base + PCIE_MISC_MISC_CTRL);
+
+	/* disable the PCIe->GISB memory window (RC_BAR1) */
+	tmp = readl(base + PCIE_MISC_RC_BAR1_CONFIG_LO);
+	tmp &= ~PCIE_MISC_RC_BAR1_CONFIG_LO_SIZE_MASK;
+	writel(tmp, base + PCIE_MISC_RC_BAR1_CONFIG_LO);
+
+	/* disable the PCIe->SCB memory window (RC_BAR3) */
+	tmp = readl(base + PCIE_MISC_RC_BAR3_CONFIG_LO);
+	tmp &= ~PCIE_MISC_RC_BAR3_CONFIG_LO_SIZE_MASK;
+	writel(tmp, base + PCIE_MISC_RC_BAR3_CONFIG_LO);
+
+	/* Mask all interrupts since we are not handling any yet */
+	writel(0xffffffff, pcie->base + PCIE_MSI_INTR2_MASK_SET);
+
+	/* clear any interrupts we find on boot */
+	writel(0xffffffff, pcie->base + PCIE_MSI_INTR2_CLR);
+
+	if (pcie->gen)
+		brcm_pcie_set_gen(pcie, pcie->gen);
+
+	/* Unassert the fundamental reset */
+	brcm_pcie_perst_set(pcie, 0);
+
+	/*
+	 * Give the RC/EP time to wake up, before trying to configure RC.
+	 * Intermittently check status for link-up, up to a total of 100ms.
+	 */
+	for (i = 0; i < 100 && !brcm_pcie_link_up(pcie); i += 5)
+		msleep(5);
+
+	if (!brcm_pcie_link_up(pcie)) {
+		dev_err(dev, "link down\n");
+		return -ENODEV;
+	}
+
+	if (!brcm_pcie_rc_mode(pcie)) {
+		dev_err(dev, "PCIe misconfigured; is in EP mode\n");
+		return -EINVAL;
+	}
+
+	resource_list_for_each_entry(entry, &bridge->windows) {
+		res = entry->res;
+
+		if (resource_type(res) != IORESOURCE_MEM)
+			continue;
+
+		if (num_out_wins >= BRCM_NUM_PCIE_OUT_WINS) {
+			dev_err(pcie->dev, "too many outbound wins\n");
+			return -EINVAL;
+		}
+
+		brcm_pcie_set_outbound_win(pcie, num_out_wins, res->start,
+					   res->start - entry->offset,
+					   res->end - res->start + 1);
+		num_out_wins++;
+	}
+
+	/*
+	 * For config space accesses on the RC, show the right class for
+	 * a PCIe-PCIe bridge (the default setting is to be EP mode).
+	 */
+	tmp = readl(base + PCIE_RC_CFG_PRIV1_ID_VAL3);
+	u32p_replace_bits(&tmp, 0x060400,
+			  PCIE_RC_CFG_PRIV1_ID_VAL3_CLASS_CODE_MASK);
+	writel(tmp, base + PCIE_RC_CFG_PRIV1_ID_VAL3);
+
+	if (pcie->ssc) {
+		ret = brcm_pcie_set_ssc(pcie);
+		if (ret == 0)
+			ssc_good = true;
+		else
+			dev_err(dev, "failed attempt to enter ssc mode\n");
+	}
+
+	lnksta = readw(base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKSTA);
+	cls = FIELD_GET(PCI_EXP_LNKSTA_CLS, lnksta);
+	nlw = FIELD_GET(PCI_EXP_LNKSTA_NLW, lnksta);
+	dev_info(dev, "link up, %s x%u %s\n",
+		 PCIE_SPEED2STR(cls + PCI_SPEED_133MHz_PCIX_533),
+		 nlw, ssc_good ? "(SSC)" : "(!SSC)");
+
+	/* PCIe->SCB endian mode for BAR */
+	tmp = readl(base + PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1);
+	u32p_replace_bits(&tmp, PCIE_RC_CFG_VENDOR_SPCIFIC_REG1_LITTLE_ENDIAN,
+		PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1_ENDIAN_MODE_BAR2_MASK);
+	writel(tmp, base + PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1);
+
+	/*
+	 * Refclk from RC should be gated with CLKREQ# input when ASPM L0s,L1
+	 * is enabled => setting the CLKREQ_DEBUG_ENABLE field to 1.
+	 */
+	tmp = readl(base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
+	tmp |= PCIE_MISC_HARD_PCIE_HARD_DEBUG_CLKREQ_DEBUG_ENABLE_MASK;
+	writel(tmp, base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
+
+	return 0;
+}
+
+/* L23 is a low-power PCIe link state */
+static void brcm_pcie_enter_l23(struct brcm_pcie *pcie)
+{
+	void __iomem *base = pcie->base;
+	int l23, i;
+	u32 tmp;
+
+	/* Assert request for L23 */
+	tmp = readl(base + PCIE_MISC_PCIE_CTRL);
+	u32p_replace_bits(&tmp, 1, PCIE_MISC_PCIE_CTRL_PCIE_L23_REQUEST_MASK);
+	writel(tmp, base + PCIE_MISC_PCIE_CTRL);
+
+	/* Wait up to 36 msec for L23 */
+	tmp = readl(base + PCIE_MISC_PCIE_STATUS);
+	l23 = FIELD_GET(PCIE_MISC_PCIE_STATUS_PCIE_LINK_IN_L23_MASK, tmp);
+	for (i = 0; i < 15 && !l23; i++) {
+		usleep_range(2000, 2400);
+		tmp = readl(base + PCIE_MISC_PCIE_STATUS);
+		l23 = FIELD_GET(PCIE_MISC_PCIE_STATUS_PCIE_LINK_IN_L23_MASK,
+				tmp);
+	}
+
+	if (!l23)
+		dev_err(pcie->dev, "failed to enter low-power link state\n");
+}
+
+static void brcm_pcie_turn_off(struct brcm_pcie *pcie)
+{
+	void __iomem *base = pcie->base;
+	int tmp;
+
+	if (brcm_pcie_link_up(pcie))
+		brcm_pcie_enter_l23(pcie);
+	/* Assert fundamental reset */
+	brcm_pcie_perst_set(pcie, 1);
+
+	/* Deassert request for L23 in case it was asserted */
+	tmp = readl(base + PCIE_MISC_PCIE_CTRL);
+	u32p_replace_bits(&tmp, 0, PCIE_MISC_PCIE_CTRL_PCIE_L23_REQUEST_MASK);
+	writel(tmp, base + PCIE_MISC_PCIE_CTRL);
+
+	/* Turn off SerDes */
+	tmp = readl(base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
+	u32p_replace_bits(&tmp, 1, PCIE_MISC_HARD_PCIE_HARD_DEBUG_SERDES_IDDQ_MASK);
+	writel(tmp, base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
+
+	/* Shutdown PCIe bridge */
+	brcm_pcie_bridge_sw_init_set(pcie, 1);
+}
+
+static void __brcm_pcie_remove(struct brcm_pcie *pcie)
+{
+	brcm_pcie_turn_off(pcie);
+	clk_disable_unprepare(pcie->clk);
+	clk_put(pcie->clk);
+}
+
+static int brcm_pcie_remove(struct platform_device *pdev)
+{
+	struct brcm_pcie *pcie = platform_get_drvdata(pdev);
+
+	pci_stop_root_bus(pcie->root_bus);
+	pci_remove_root_bus(pcie->root_bus);
+	__brcm_pcie_remove(pcie);
+
+	return 0;
+}
+
+static int brcm_pcie_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct pci_host_bridge *bridge;
+	struct brcm_pcie *pcie;
+	struct pci_bus *child;
+	struct resource *res;
+	int ret;
+
+	bridge = devm_pci_alloc_host_bridge(&pdev->dev, sizeof(*pcie));
+	if (!bridge)
+		return -ENOMEM;
+
+	pcie = pci_host_bridge_priv(bridge);
+	pcie->dev = &pdev->dev;
+	pcie->np = np;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	pcie->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(pcie->base))
+		return PTR_ERR(pcie->base);
+
+	pcie->clk = devm_clk_get_optional(&pdev->dev, "sw_pcie");
+	if (IS_ERR(pcie->clk))
+		return PTR_ERR(pcie->clk);
+
+	ret = of_pci_get_max_link_speed(np);
+	pcie->gen = (ret < 0) ? 0 : ret;
+
+	pcie->ssc = of_property_read_bool(np, "brcm,enable-ssc");
+
+	ret = pci_parse_request_of_pci_ranges(pcie->dev, &bridge->windows,
+					      &bridge->dma_ranges, NULL);
+	if (ret)
+		return ret;
+
+	ret = clk_prepare_enable(pcie->clk);
+	if (ret) {
+		dev_err(&pdev->dev, "could not enable clock\n");
+		return ret;
+	}
+
+	ret = brcm_pcie_setup(pcie);
+	if (ret)
+		goto fail;
+
+	bridge->dev.parent = &pdev->dev;
+	bridge->busnr = 0;
+	bridge->ops = &brcm_pcie_ops;
+	bridge->sysdata = pcie;
+	bridge->map_irq = of_irq_parse_and_map_pci;
+	bridge->swizzle_irq = pci_common_swizzle;
+
+	ret = pci_scan_root_bus_bridge(bridge);
+	if (ret < 0) {
+		dev_err(pcie->dev, "Scanning root bridge failed\n");
+		goto fail;
+	}
+
+	pci_assign_unassigned_bus_resources(bridge->bus);
+	list_for_each_entry(child, &bridge->bus->children, node)
+		pcie_bus_configure_settings(child);
+	pci_bus_add_devices(bridge->bus);
+	platform_set_drvdata(pdev, pcie);
+	pcie->root_bus = bridge->bus;
+
+	return 0;
+fail:
+	__brcm_pcie_remove(pcie);
+	return ret;
+}
+
+static const struct of_device_id brcm_pcie_match[] = {
+	{ .compatible = "brcm,bcm2711-pcie" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, brcm_pcie_match);
+
+static struct platform_driver brcm_pcie_driver = {
+	.probe = brcm_pcie_probe,
+	.remove = brcm_pcie_remove,
+	.driver = {
+		.name = "brcm-pcie",
+		.of_match_table = brcm_pcie_match,
+	},
+};
+module_platform_driver(brcm_pcie_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Broadcom STB PCIe RC driver");
+MODULE_AUTHOR("Broadcom");
-- 
2.24.0


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

[PATCH v3 5/7] PCI: brcmstb: add MSI capability

[Nicolas Saenz Julienne]

From: Jim Quinlan <james.quinlan@broadcom.com>

This adds MSI support to the Broadcom STB PCIe host controller. The MSI
controller is physically located within the PCIe block, however, there
is no reason why the MSI controller could not be moved elsewhere in the
future. MSIX is not supported by the HW.

Since the internal Brcmstb MSI controller is intertwined with the PCIe
controller, it is not its own platform device but rather part of the
PCIe platform device.

Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>
Co-developed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: Marc Zyngier <maz@kernel.org>

---

Changes since v2 (kept Marc's Reviewed-by as changes didn't affect irq
subsystem stuff or seem petty enough):
  - Use standard APIs on register operations
  - Get rid of revision code
  - Update rules to msi_target_addr selection
  - Remove unwarranted MSI_FLAG_PCI_MSIX
  - Small cosmetic changes

Changes since v1:
  - Move revision code and some registers to this patch
  - Use PCIE_MSI_IRQ_DOMAIN in Kconfig
  - Remove redundant register read from ISR
  - Fail probe on MSI init error
  - Get rid of msi_internal
  - Use bitmap family of functions
  - Use edge triggered setup
  - Add comment regarding MultiMSI
  - Simplify compose_msi_msg to avoid reg read

This is based on Jim's original submission[1] with some slight changes
regarding how pcie->msi_target_addr is decided.

[1] https://patchwork.kernel.org/patch/10605955/

 drivers/pci/controller/Kconfig        |   1 +
 drivers/pci/controller/pcie-brcmstb.c | 261 +++++++++++++++++++++++++-
 2 files changed, 261 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig
index 27504f108ee5..918e283bbff1 100644
--- a/drivers/pci/controller/Kconfig
+++ b/drivers/pci/controller/Kconfig
@@ -257,6 +257,7 @@ config PCIE_BRCMSTB
 	tristate "Broadcom Brcmstb PCIe host controller"
 	depends on ARCH_BCM2835 || COMPILE_TEST
 	depends on OF
+	depends on PCI_MSI_IRQ_DOMAIN
 	help
 	  Say Y here to enable PCIe host controller support for
 	  Broadcom STB based SoCs, like the Raspberry Pi 4.
diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
index 28c1b9429d3d..eaf0119c08bf 100644
--- a/drivers/pci/controller/pcie-brcmstb.c
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -2,6 +2,7 @@
 /* Copyright (C) 2009 - 2019 Broadcom */
 
 #include <linux/bitfield.h>
+#include <linux/bitops.h>
 #include <linux/clk.h>
 #include <linux/compiler.h>
 #include <linux/delay.h>
@@ -9,11 +10,13 @@
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/ioport.h>
+#include <linux/irqchip/chained_irq.h>
 #include <linux/irqdomain.h>
 #include <linux/kernel.h>
 #include <linux/list.h>
 #include <linux/log2.h>
 #include <linux/module.h>
+#include <linux/msi.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
 #include <linux/of_pci.h>
@@ -71,6 +74,12 @@
 #define PCIE_MISC_RC_BAR3_CONFIG_LO			0x403c
 #define  PCIE_MISC_RC_BAR3_CONFIG_LO_SIZE_MASK		0x1f
 
+#define PCIE_MISC_MSI_BAR_CONFIG_LO			0x4044
+#define PCIE_MISC_MSI_BAR_CONFIG_HI			0x4048
+
+#define PCIE_MISC_MSI_DATA_CONFIG			0x404c
+#define  PCIE_MISC_MSI_DATA_CONFIG_VAL			0xffe06540
+
 #define PCIE_MISC_PCIE_CTRL				0x4064
 #define  PCIE_MISC_PCIE_CTRL_PCIE_L23_REQUEST_MASK	0x1
 
@@ -118,6 +127,11 @@
 
 /* PCIe parameters */
 #define BRCM_NUM_PCIE_OUT_WINS		0x4
+#define BRCM_INT_PCI_MSI_NR		32
+
+/* MSI target adresses */
+#define BRCM_MSI_TARGET_ADDR_LT_4GB	0x0fffffffcULL
+#define BRCM_MSI_TARGET_ADDR_GT_4GB	0xffffffffcULL
 
 /* MDIO registers */
 #define MDIO_PORT0			0x0
@@ -139,6 +153,19 @@
 #define SSC_STATUS_SSC_MASK		0x400
 #define SSC_STATUS_PLL_LOCK_MASK	0x800
 
+struct brcm_msi {
+	struct device		*dev;
+	void __iomem		*base;
+	struct device_node	*np;
+	struct irq_domain	*msi_domain;
+	struct irq_domain	*inner_domain;
+	struct mutex		lock; /* guards the alloc/free operations */
+	u64			target_addr;
+	int			irq;
+	/* used indicates which MSI interrupts have been alloc'd */
+	unsigned long		used;
+};
+
 /* Internal PCIe Host Controller Information.*/
 struct brcm_pcie {
 	struct device		*dev;
@@ -148,6 +175,8 @@ struct brcm_pcie {
 	struct device_node	*np;
 	bool			ssc;
 	int			gen;
+	u64			msi_target_addr;
+	struct brcm_msi		*msi;
 };
 
 /*
@@ -313,6 +342,214 @@ static void brcm_pcie_set_outbound_win(struct brcm_pcie *pcie,
 	writel(tmp, pcie->base + PCIE_MEM_WIN0_LIMIT_HI(win));
 }
 
+static struct irq_chip brcm_msi_irq_chip = {
+	.name            = "BRCM STB PCIe MSI",
+	.irq_ack         = irq_chip_ack_parent,
+	.irq_mask        = pci_msi_mask_irq,
+	.irq_unmask      = pci_msi_unmask_irq,
+};
+
+static struct msi_domain_info brcm_msi_domain_info = {
+	/* Multi MSI is supported by the controller, but not by this driver */
+	.flags	= (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
+	.chip	= &brcm_msi_irq_chip,
+};
+
+static void brcm_pcie_msi_isr(struct irq_desc *desc)
+{
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	unsigned long status, virq;
+	struct brcm_msi *msi;
+	struct device *dev;
+	u32 bit;
+
+	chained_irq_enter(chip, desc);
+	msi = irq_desc_get_handler_data(desc);
+	dev = msi->dev;
+
+	status = readl(msi->base + PCIE_MSI_INTR2_STATUS);
+	for_each_set_bit(bit, &status, BRCM_INT_PCI_MSI_NR) {
+		virq = irq_find_mapping(msi->inner_domain, bit);
+		if (virq)
+			generic_handle_irq(virq);
+		else
+			dev_dbg(dev, "unexpected MSI\n");
+	}
+
+	chained_irq_exit(chip, desc);
+}
+
+static void brcm_msi_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
+{
+	struct brcm_msi *msi = irq_data_get_irq_chip_data(data);
+
+	msg->address_lo = lower_32_bits(msi->target_addr);
+	msg->address_hi = upper_32_bits(msi->target_addr);
+	msg->data = 0x6540 | data->hwirq;
+}
+
+static int brcm_msi_set_affinity(struct irq_data *irq_data,
+				 const struct cpumask *mask, bool force)
+{
+	return -EINVAL;
+}
+
+static void brcm_msi_ack_irq(struct irq_data *data)
+{
+	struct brcm_msi *msi = irq_data_get_irq_chip_data(data);
+
+	writel(1 << data->hwirq, msi->base + PCIE_MSI_INTR2_CLR);
+}
+
+
+static struct irq_chip brcm_msi_bottom_irq_chip = {
+	.name			= "BRCM STB MSI",
+	.irq_compose_msi_msg	= brcm_msi_compose_msi_msg,
+	.irq_set_affinity	= brcm_msi_set_affinity,
+	.irq_ack                = brcm_msi_ack_irq,
+};
+
+static int brcm_msi_alloc(struct brcm_msi *msi)
+{
+	int hwirq;
+
+	mutex_lock(&msi->lock);
+	hwirq = bitmap_find_free_region(&msi->used, BRCM_INT_PCI_MSI_NR, 0);
+	mutex_unlock(&msi->lock);
+
+	return hwirq;
+}
+
+static void brcm_msi_free(struct brcm_msi *msi, unsigned long hwirq)
+{
+	mutex_lock(&msi->lock);
+	bitmap_release_region(&msi->used, hwirq, 0);
+	mutex_unlock(&msi->lock);
+}
+
+static int brcm_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
+				 unsigned int nr_irqs, void *args)
+{
+	struct brcm_msi *msi = domain->host_data;
+	int hwirq;
+
+	hwirq = brcm_msi_alloc(msi);
+
+	if (hwirq < 0)
+		return hwirq;
+
+	irq_domain_set_info(domain, virq, (irq_hw_number_t)hwirq,
+			    &brcm_msi_bottom_irq_chip, domain->host_data,
+			    handle_edge_irq, NULL, NULL);
+	return 0;
+}
+
+static void brcm_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);
+	struct brcm_msi *msi = irq_data_get_irq_chip_data(d);
+
+	brcm_msi_free(msi, d->hwirq);
+}
+
+static const struct irq_domain_ops msi_domain_ops = {
+	.alloc	= brcm_irq_domain_alloc,
+	.free	= brcm_irq_domain_free,
+};
+
+static int brcm_allocate_domains(struct brcm_msi *msi)
+{
+	struct fwnode_handle *fwnode = of_node_to_fwnode(msi->np);
+	struct device *dev = msi->dev;
+
+	msi->inner_domain = irq_domain_add_linear(NULL, BRCM_INT_PCI_MSI_NR,
+						  &msi_domain_ops, msi);
+	if (!msi->inner_domain) {
+		dev_err(dev, "failed to create IRQ domain\n");
+		return -ENOMEM;
+	}
+
+	msi->msi_domain = pci_msi_create_irq_domain(fwnode,
+						    &brcm_msi_domain_info,
+						    msi->inner_domain);
+	if (!msi->msi_domain) {
+		dev_err(dev, "failed to create MSI domain\n");
+		irq_domain_remove(msi->inner_domain);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static void brcm_free_domains(struct brcm_msi *msi)
+{
+	irq_domain_remove(msi->msi_domain);
+	irq_domain_remove(msi->inner_domain);
+}
+
+static void brcm_msi_remove(struct brcm_pcie *pcie)
+{
+	struct brcm_msi *msi = pcie->msi;
+
+	if (!msi)
+		return;
+	irq_set_chained_handler(msi->irq, NULL);
+	irq_set_handler_data(msi->irq, NULL);
+	brcm_free_domains(msi);
+}
+
+static void brcm_msi_set_regs(struct brcm_msi *msi)
+{
+	writel(0xffffffff, msi->base + PCIE_MSI_INTR2_MASK_CLR);
+
+	/*
+	 * The 0 bit of PCIE_MISC_MSI_BAR_CONFIG_LO is repurposed to MSI
+	 * enable, which we set to 1.
+	 */
+	writel(lower_32_bits(msi->target_addr) | 0x1,
+	       msi->base + PCIE_MISC_MSI_BAR_CONFIG_LO);
+	writel(upper_32_bits(msi->target_addr),
+	       msi->base + PCIE_MISC_MSI_BAR_CONFIG_HI);
+
+	writel(PCIE_MISC_MSI_DATA_CONFIG_VAL,
+	       msi->base + PCIE_MISC_MSI_DATA_CONFIG);
+}
+
+static int brcm_pcie_enable_msi(struct brcm_pcie *pcie)
+{
+	struct brcm_msi *msi;
+	int irq, ret;
+	struct device *dev = pcie->dev;
+
+	irq = irq_of_parse_and_map(dev->of_node, 1);
+	if (irq <= 0) {
+		dev_err(dev, "cannot map MSI interrupt\n");
+		return -ENODEV;
+	}
+
+	msi = devm_kzalloc(dev, sizeof(struct brcm_msi), GFP_KERNEL);
+	if (!msi)
+		return -ENOMEM;
+
+	msi->dev = dev;
+	msi->base = pcie->base;
+	msi->np = pcie->np;
+	msi->target_addr = pcie->msi_target_addr;
+	msi->irq = irq;
+
+	ret = brcm_allocate_domains(msi);
+	if (ret)
+		return ret;
+
+	irq_set_chained_handler_and_data(msi->irq, brcm_pcie_msi_isr, msi);
+
+	brcm_msi_set_regs(msi);
+	pcie->msi = msi;
+
+	return 0;
+}
+
 /* The controller is capable of serving in both RC and EP roles */
 static bool brcm_pcie_rc_mode(struct brcm_pcie *pcie)
 {
@@ -495,6 +732,18 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie)
 			  PCIE_MISC_MISC_CTRL_SCB0_SIZE_MASK);
 	writel(tmp, base + PCIE_MISC_MISC_CTRL);
 
+	/*
+	 * We ideally want the MSI target address to be located in the 32bit
+	 * addressable memory area. Some devices might depend on it. This is
+	 * possible either when the inbound window is located above the lower
+	 * 4GB or when the inbound area is smaller than 4GB (taking into
+	 * account the rounding-up we're forced to perform).
+	 */
+	if (rc_bar2_offset >= SZ_4G || (rc_bar2_size + rc_bar2_offset) < SZ_4G)
+		pcie->msi_target_addr = BRCM_MSI_TARGET_ADDR_LT_4GB;
+	else
+		pcie->msi_target_addr = BRCM_MSI_TARGET_ADDR_GT_4GB;
+
 	/* disable the PCIe->GISB memory window (RC_BAR1) */
 	tmp = readl(base + PCIE_MISC_RC_BAR1_CONFIG_LO);
 	tmp &= ~PCIE_MISC_RC_BAR1_CONFIG_LO_SIZE_MASK;
@@ -644,6 +893,7 @@ static void brcm_pcie_turn_off(struct brcm_pcie *pcie)
 
 static void __brcm_pcie_remove(struct brcm_pcie *pcie)
 {
+	brcm_msi_remove(pcie);
 	brcm_pcie_turn_off(pcie);
 	clk_disable_unprepare(pcie->clk);
 	clk_put(pcie->clk);
@@ -662,7 +912,7 @@ static int brcm_pcie_remove(struct platform_device *pdev)
 
 static int brcm_pcie_probe(struct platform_device *pdev)
 {
-	struct device_node *np = pdev->dev.of_node;
+	struct device_node *np = pdev->dev.of_node, *msi_np;
 	struct pci_host_bridge *bridge;
 	struct brcm_pcie *pcie;
 	struct pci_bus *child;
@@ -706,6 +956,15 @@ static int brcm_pcie_probe(struct platform_device *pdev)
 	if (ret)
 		goto fail;
 
+	msi_np = of_parse_phandle(pcie->np, "msi-parent", 0);
+	if (pci_msi_enabled() && msi_np == pcie->np) {
+		ret = brcm_pcie_enable_msi(pcie);
+		if (ret) {
+			dev_err(pcie->dev, "probe of internal MSI failed");
+			goto fail;
+		}
+	}
+
 	bridge->dev.parent = &pdev->dev;
 	bridge->busnr = 0;
 	bridge->ops = &brcm_pcie_ops;
-- 
2.24.0


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[PATCH v3 7/7] arm64: defconfig: Enable Broadcom's STB PCIe controller

[Nicolas Saenz Julienne]

For now only used in the Raspberry Pi 4.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
---
 arch/arm64/configs/defconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
index 7fa92defb964..dfd578129780 100644
--- a/arch/arm64/configs/defconfig
+++ b/arch/arm64/configs/defconfig
@@ -198,6 +198,7 @@ CONFIG_PCIE_ALTERA_MSI=y
 CONFIG_PCI_HOST_THUNDER_PEM=y
 CONFIG_PCI_HOST_THUNDER_ECAM=y
 CONFIG_PCIE_ROCKCHIP_HOST=m
+CONFIG_PCIE_BRCMSTB=m
 CONFIG_PCI_LAYERSCAPE=y
 CONFIG_PCI_HISI=y
 CONFIG_PCIE_QCOM=y
-- 
2.24.0


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Re: [PATCH v3 3/7] ARM: dts: bcm2711: Enable PCIe controller

[Phil Elwell]

Hi Nicolas,

On 26/11/2019 09:19, Nicolas Saenz Julienne wrote:
> This enables bcm2711's PCIe bus, which is hardwired to a VIA
> Technologies XHCI USB 3.0 controller.
> 
> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> 
> ---
> 
> This will likely need a rebase once the RPi GENET patches land.
> 
> Changes since v2:
>    - Remove unused interrupt-map
>    - correct dma-ranges to it's full size, non power of 2 bus DMA
>      constraints now supported in linux-next[1]
>    - add device_type
>    - rename alias from pcie_0 to pcie0
> 
> Changes since v1:
>    - remove linux,pci-domain
> 
> [1] https://lkml.org/lkml/2019/11/21/235
> 
>   arch/arm/boot/dts/bcm2711.dtsi | 41 ++++++++++++++++++++++++++++++++++
>   1 file changed, 41 insertions(+)
> 
> diff --git a/arch/arm/boot/dts/bcm2711.dtsi b/arch/arm/boot/dts/bcm2711.dtsi
> index 667658497898..2e121fc8b3d0 100644
> --- a/arch/arm/boot/dts/bcm2711.dtsi
> +++ b/arch/arm/boot/dts/bcm2711.dtsi
> @@ -288,6 +288,47 @@ IRQ_TYPE_LEVEL_LOW)>,
>   		arm,cpu-registers-not-fw-configured;
>   	};
>   
> +	scb {
> +		compatible = "simple-bus";
> +		#address-cells = <2>;
> +		#size-cells = <1>;
> +
> +		ranges = <0x0 0x7c000000  0x0 0xfc000000  0x03800000>,
> +			 <0x6 0x00000000  0x6 0x00000000  0x40000000>;
> +
> +		pcie0: pcie@7d500000 {
> +			compatible = "brcm,bcm2711-pcie";
> +			reg = <0x0 0x7d500000 0x9310>;
> +			device_type = "pci";
> +			#address-cells = <3>;
> +			#interrupt-cells = <1>;
> +			#size-cells = <2>;
> +			interrupts = <GIC_SPI 148 IRQ_TYPE_LEVEL_HIGH>,
> +				     <GIC_SPI 148 IRQ_TYPE_LEVEL_HIGH>;
> +			interrupt-names = "pcie", "msi";
> +			interrupt-map-mask = <0x0 0x0 0x0 0x7>;
> +			interrupt-map = <0 0 0 1 &gicv2 GIC_SPI 143
> +							IRQ_TYPE_LEVEL_HIGH>;
> +			msi-controller;
> +			msi-parent = <&pcie0>;
> +
> +			ranges = <0x02000000 0x0 0xf8000000 0x6 0x00000000
> +				  0x0 0x04000000>;
> +			/*
> +			 * The wrapper around the PCIe block has a bug
> +			 * preventing it from accessing beyond the first 3GB of
> +			 * memory. As the bus DMA mask is rounded up to the
> +			 * closest power of two of the dma-range size, we're
> +			 * forced to set the limit at 2GB. This can be
> +			 * harmlessly changed in the future once the DMA code
> +			 * handles non power of two DMA limits.
> +			 */
> +			dma-ranges = <0x02000000 0x0 0x00000000 0x0 0x00000000
> +				      0x0 0xc0000000>;

The comment doesn't match the data here - I think for now the size field 
needs to be reduced to 2GB to match the comment.

Phil

> +			brcm,enable-ssc;
> +		};
> +	};
> +
>   	cpus: cpus {
>   		#address-cells = <1>;
>   		#size-cells = <0>;
> 

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Re: [PATCH v3 3/7] ARM: dts: bcm2711: Enable PCIe controller

[Nicolas Saenz Julienne]

[-- Attachment #1.1: Type: text/plain, Size: 3250 bytes --]

On Tue, 2019-11-26 at 09:37 +0000, Phil Elwell wrote:
> Hi Nicolas,
> 
> On 26/11/2019 09:19, Nicolas Saenz Julienne wrote:
> > This enables bcm2711's PCIe bus, which is hardwired to a VIA
> > Technologies XHCI USB 3.0 controller.
> > 
> > Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> > 
> > ---
> > 
> > This will likely need a rebase once the RPi GENET patches land.
> > 
> > Changes since v2:
> >    - Remove unused interrupt-map
> >    - correct dma-ranges to it's full size, non power of 2 bus DMA
> >      constraints now supported in linux-next[1]
> >    - add device_type
> >    - rename alias from pcie_0 to pcie0
> > 
> > Changes since v1:
> >    - remove linux,pci-domain
> > 
> > [1] https://lkml.org/lkml/2019/11/21/235
> > 
> >   arch/arm/boot/dts/bcm2711.dtsi | 41 ++++++++++++++++++++++++++++++++++
> >   1 file changed, 41 insertions(+)
> > 
> > diff --git a/arch/arm/boot/dts/bcm2711.dtsi b/arch/arm/boot/dts/bcm2711.dtsi
> > index 667658497898..2e121fc8b3d0 100644
> > --- a/arch/arm/boot/dts/bcm2711.dtsi
> > +++ b/arch/arm/boot/dts/bcm2711.dtsi
> > @@ -288,6 +288,47 @@ IRQ_TYPE_LEVEL_LOW)>,
> >   		arm,cpu-registers-not-fw-configured;
> >   	};
> >   
> > +	scb {
> > +		compatible = "simple-bus";
> > +		#address-cells = <2>;
> > +		#size-cells = <1>;
> > +
> > +		ranges = <0x0 0x7c000000  0x0 0xfc000000  0x03800000>,
> > +			 <0x6 0x00000000  0x6 0x00000000  0x40000000>;
> > +
> > +		pcie0: pcie@7d500000 {
> > +			compatible = "brcm,bcm2711-pcie";
> > +			reg = <0x0 0x7d500000 0x9310>;
> > +			device_type = "pci";
> > +			#address-cells = <3>;
> > +			#interrupt-cells = <1>;
> > +			#size-cells = <2>;
> > +			interrupts = <GIC_SPI 148 IRQ_TYPE_LEVEL_HIGH>,
> > +				     <GIC_SPI 148 IRQ_TYPE_LEVEL_HIGH>;
> > +			interrupt-names = "pcie", "msi";
> > +			interrupt-map-mask = <0x0 0x0 0x0 0x7>;
> > +			interrupt-map = <0 0 0 1 &gicv2 GIC_SPI 143
> > +							IRQ_TYPE_LEVEL_HIGH>;
> > +			msi-controller;
> > +			msi-parent = <&pcie0>;
> > +
> > +			ranges = <0x02000000 0x0 0xf8000000 0x6 0x00000000
> > +				  0x0 0x04000000>;
> > +			/*
> > +			 * The wrapper around the PCIe block has a bug
> > +			 * preventing it from accessing beyond the first 3GB of
> > +			 * memory. As the bus DMA mask is rounded up to the
> > +			 * closest power of two of the dma-range size, we're
> > +			 * forced to set the limit at 2GB. This can be
> > +			 * harmlessly changed in the future once the DMA code
> > +			 * handles non power of two DMA limits.
> > +			 */
> > +			dma-ranges = <0x02000000 0x0 0x00000000 0x0 0x00000000
> > +				      0x0 0xc0000000>;
> 
> The comment doesn't match the data here - I think for now the size field 
> needs to be reduced to 2GB to match the comment.

You're right, my bad, should've edited it out. The good part is that with this
commit[1], which will soon be in Linus' tree, we don't need to fake dma-ranges
size anymore.

So for the record, the comment should state the following:

	/*
	 * The wrapper around the PCIe block has a bug
	 * preventing it from accessing beyond the first 3GB of
	 * memory.
	 */

Regards,
Nicolas

[1] https://lkml.org/lkml/2019/11/21/235


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Re: [PATCH v3 1/7] linux/log2.h: Add roundup/rounddown_pow_two64() family of functions

[Leon Romanovsky]

On Tue, Nov 26, 2019 at 10:19:39AM +0100, Nicolas Saenz Julienne wrote:
> Some users need to make sure their rounding function accepts and returns
> 64bit long variables regardless of the architecture. Sadly
> roundup/rounddown_pow_two() takes and returns unsigned longs. Create a
> new generic 64bit variant of the function and cleanup rougue custom
> implementations.

Is it possible to create general roundup/rounddown_pow_two() which will
work correctly for any type of variables, instead of creating special
variant for every type?

Thanks

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Re: [PATCH v3 0/7] Raspberry Pi 4 PCIe support

[Bjorn Helgaas]

On Tue, Nov 26, 2019 at 10:19:38AM +0100, Nicolas Saenz Julienne wrote:
> This series aims at providing support for Raspberry Pi 4's PCIe
> controller, which is also shared with the Broadcom STB family of
> devices.

> Jim Quinlan (3):
>   dt-bindings: PCI: Add bindings for brcmstb's PCIe device
>   PCI: brcmstb: add Broadcom STB PCIe host controller driver
>   PCI: brcmstb: add MSI capability

Please update these subjects to match the others, i.e., capitalize
"Add".  Also, I think "Add MSI capability" really means "Add support
for MSI ..."; in PCIe terms the "MSI Capability" is a structure in
config space and it's there whether the OS supports it or not.

No need to repost just for this.

> Nicolas Saenz Julienne (4):
>   linux/log2.h: Add roundup/rounddown_pow_two64() family of functions
>   ARM: dts: bcm2711: Enable PCIe controller
>   MAINTAINERS: Add brcmstb PCIe controller
>   arm64: defconfig: Enable Broadcom's STB PCIe controller

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Re: [PATCH v3 0/7] Raspberry Pi 4 PCIe support

[Nicolas Saenz Julienne]

[-- Attachment #1.1: Type: text/plain, Size: 863 bytes --]

Hi Bjorn,

On Tue, 2019-11-26 at 15:50 -0600, Bjorn Helgaas wrote:
> On Tue, Nov 26, 2019 at 10:19:38AM +0100, Nicolas Saenz Julienne wrote:
> > This series aims at providing support for Raspberry Pi 4's PCIe
> > controller, which is also shared with the Broadcom STB family of
> > devices.
> > Jim Quinlan (3):
> >   dt-bindings: PCI: Add bindings for brcmstb's PCIe device
> >   PCI: brcmstb: add Broadcom STB PCIe host controller driver
> >   PCI: brcmstb: add MSI capability
> 
> Please update these subjects to match the others, i.e., capitalize
> "Add".  Also, I think "Add MSI capability" really means "Add support
> for MSI ..."; in PCIe terms the "MSI Capability" is a structure in
> config space and it's there whether the OS supports it or not.
> 
> No need to repost just for this.

Noted, I'll update them.

Regards,
Nicolas


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Re: [PATCH v3 1/7] linux/log2.h: Add roundup/rounddown_pow_two64() family of functions

[Nicolas Saenz Julienne]

[-- Attachment #1.1: Type: text/plain, Size: 648 bytes --]

On Tue, 2019-11-26 at 10:19 +0100, Nicolas Saenz Julienne wrote:
> Some users need to make sure their rounding function accepts and returns
> 64bit long variables regardless of the architecture. Sadly
> roundup/rounddown_pow_two() takes and returns unsigned longs. Create a
> new generic 64bit variant of the function and cleanup rougue custom
> implementations.
> 
> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>

Small Nit: I corrected the patch subject for next version.

linux/log2.h: Add roundup/rounddown_pow_two_u64() family of functions

Note the change here:                      ^^^^

Regards,
Nicolas


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Re: [PATCH v3 1/7] linux/log2.h: Add roundup/rounddown_pow_two64() family of functions

[Robin Murphy]

On 26/11/2019 12:51 pm, Leon Romanovsky wrote:
> On Tue, Nov 26, 2019 at 10:19:39AM +0100, Nicolas Saenz Julienne wrote:
>> Some users need to make sure their rounding function accepts and returns
>> 64bit long variables regardless of the architecture. Sadly
>> roundup/rounddown_pow_two() takes and returns unsigned longs. Create a
>> new generic 64bit variant of the function and cleanup rougue custom
>> implementations.
> 
> Is it possible to create general roundup/rounddown_pow_two() which will
> work correctly for any type of variables, instead of creating special
> variant for every type?

In fact, that is sort of the case already - roundup_pow_of_two() itself 
wraps ilog2() such that the constant case *is* type-independent. And 
since ilog2() handles non-constant values anyway, might it be reasonable 
to just take the strongly-typed __roundup_pow_of_two() helper out of the 
loop as below?

Robin

----->8-----
diff --git a/include/linux/log2.h b/include/linux/log2.h
index 83a4a3ca3e8a..e825f8a6e8b5 100644
--- a/include/linux/log2.h
+++ b/include/linux/log2.h
@@ -172,11 +172,8 @@ unsigned long __rounddown_pow_of_two(unsigned long n)
   */
  #define roundup_pow_of_two(n)			\
  (						\
-	__builtin_constant_p(n) ? (		\
-		(n == 1) ? 1 :			\
-		(1UL << (ilog2((n) - 1) + 1))	\
-				   ) :		\
-	__roundup_pow_of_two(n)			\
+	(__builtin_constant_p(n) && (n == 1)) ?	\
+	1 : (1UL << (ilog2((n) - 1) + 1))	\
   )

  /**

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Re: [PATCH v3 1/7] linux/log2.h: Add roundup/rounddown_pow_two64() family of functions

[Nicolas Saenz Julienne]

[-- Attachment #1.1: Type: text/plain, Size: 2096 bytes --]

On Wed, 2019-11-27 at 18:06 +0000, Robin Murphy wrote:
> On 26/11/2019 12:51 pm, Leon Romanovsky wrote:
> > On Tue, Nov 26, 2019 at 10:19:39AM +0100, Nicolas Saenz Julienne wrote:
> > > Some users need to make sure their rounding function accepts and returns
> > > 64bit long variables regardless of the architecture. Sadly
> > > roundup/rounddown_pow_two() takes and returns unsigned longs. Create a
> > > new generic 64bit variant of the function and cleanup rougue custom
> > > implementations.
> > 
> > Is it possible to create general roundup/rounddown_pow_two() which will
> > work correctly for any type of variables, instead of creating special
> > variant for every type?
> 
> In fact, that is sort of the case already - roundup_pow_of_two() itself 
> wraps ilog2() such that the constant case *is* type-independent. And 
> since ilog2() handles non-constant values anyway, might it be reasonable 
> to just take the strongly-typed __roundup_pow_of_two() helper out of the 
> loop as below?
> 
> Robin
> 

That looks way better that's for sure. Some questions.

> ----->8-----
> diff --git a/include/linux/log2.h b/include/linux/log2.h
> index 83a4a3ca3e8a..e825f8a6e8b5 100644
> --- a/include/linux/log2.h
> +++ b/include/linux/log2.h
> @@ -172,11 +172,8 @@ unsigned long __rounddown_pow_of_two(unsigned long n)
>    */
>   #define roundup_pow_of_two(n)			\
>   (						\
> -	__builtin_constant_p(n) ? (		\
> -		(n == 1) ? 1 :			\
> -		(1UL << (ilog2((n) - 1) + 1))	\
> -				   ) :		\
> -	__roundup_pow_of_two(n)			\
> +	(__builtin_constant_p(n) && (n == 1)) ?	\
> +	1 : (1UL << (ilog2((n) - 1) + 1))	\

Then here you'd have to use ULL instead of UL, right? I want my 64bit value
everywhere regardless of the CPU arch. The downside is that would affect
performance to some extent (i.e. returning a 64bit value where you used to have
a 32bit one)?

Also, what about callers to this function on platforms with 32bit 'unsigned
longs' that happen to input a 64bit value into this. IIUC we'd have a change of
behaviour.

Regards,
Nicolas


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Re: [PATCH v3 1/7] linux/log2.h: Add roundup/rounddown_pow_two64() family of functions

[Robin Murphy]

On 27/11/2019 6:24 pm, Nicolas Saenz Julienne wrote:
> On Wed, 2019-11-27 at 18:06 +0000, Robin Murphy wrote:
>> On 26/11/2019 12:51 pm, Leon Romanovsky wrote:
>>> On Tue, Nov 26, 2019 at 10:19:39AM +0100, Nicolas Saenz Julienne wrote:
>>>> Some users need to make sure their rounding function accepts and returns
>>>> 64bit long variables regardless of the architecture. Sadly
>>>> roundup/rounddown_pow_two() takes and returns unsigned longs. Create a
>>>> new generic 64bit variant of the function and cleanup rougue custom
>>>> implementations.
>>>
>>> Is it possible to create general roundup/rounddown_pow_two() which will
>>> work correctly for any type of variables, instead of creating special
>>> variant for every type?
>>
>> In fact, that is sort of the case already - roundup_pow_of_two() itself
>> wraps ilog2() such that the constant case *is* type-independent. And
>> since ilog2() handles non-constant values anyway, might it be reasonable
>> to just take the strongly-typed __roundup_pow_of_two() helper out of the
>> loop as below?
>>
>> Robin
>>
> 
> That looks way better that's for sure. Some questions.
> 
>> ----->8-----
>> diff --git a/include/linux/log2.h b/include/linux/log2.h
>> index 83a4a3ca3e8a..e825f8a6e8b5 100644
>> --- a/include/linux/log2.h
>> +++ b/include/linux/log2.h
>> @@ -172,11 +172,8 @@ unsigned long __rounddown_pow_of_two(unsigned long n)
>>     */
>>    #define roundup_pow_of_two(n)			\
>>    (						\
>> -	__builtin_constant_p(n) ? (		\
>> -		(n == 1) ? 1 :			\
>> -		(1UL << (ilog2((n) - 1) + 1))	\
>> -				   ) :		\
>> -	__roundup_pow_of_two(n)			\
>> +	(__builtin_constant_p(n) && (n == 1)) ?	\
>> +	1 : (1UL << (ilog2((n) - 1) + 1))	\
> 
> Then here you'd have to use ULL instead of UL, right? I want my 64bit value
> everywhere regardless of the CPU arch. The downside is that would affect
> performance to some extent (i.e. returning a 64bit value where you used to have
> a 32bit one)?

True, although it's possible that 1ULL might result in the same codegen 
if the compiler can see that the result is immediately truncated back to 
long anyway. Or at worst, I suppose "(typeof(n))1" could suffice, 
however ugly. Either way, this diff was only an illustration rather than 
a concrete proposal, but it might be an interesting diversion to 
investigate.

On that note, though, you should probably be using ULL in your current 
patch too.

> Also, what about callers to this function on platforms with 32bit 'unsigned
> longs' that happen to input a 64bit value into this. IIUC we'd have a change of
> behaviour.

Indeed, although the change in such a case would be "start getting the 
expected value instead of nonsense", so it might very well be welcome ;)

Robin.

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Re: [PATCH v3 1/7] linux/log2.h: Add roundup/rounddown_pow_two64() family of functions

[Leon Romanovsky]

On Wed, Nov 27, 2019 at 07:06:12PM +0000, Robin Murphy wrote:
> On 27/11/2019 6:24 pm, Nicolas Saenz Julienne wrote:
> > On Wed, 2019-11-27 at 18:06 +0000, Robin Murphy wrote:
> > > On 26/11/2019 12:51 pm, Leon Romanovsky wrote:
> > > > On Tue, Nov 26, 2019 at 10:19:39AM +0100, Nicolas Saenz Julienne wrote:
> > > > > Some users need to make sure their rounding function accepts and returns
> > > > > 64bit long variables regardless of the architecture. Sadly
> > > > > roundup/rounddown_pow_two() takes and returns unsigned longs. Create a
> > > > > new generic 64bit variant of the function and cleanup rougue custom
> > > > > implementations.
> > > >
> > > > Is it possible to create general roundup/rounddown_pow_two() which will
> > > > work correctly for any type of variables, instead of creating special
> > > > variant for every type?
> > >
> > > In fact, that is sort of the case already - roundup_pow_of_two() itself
> > > wraps ilog2() such that the constant case *is* type-independent. And
> > > since ilog2() handles non-constant values anyway, might it be reasonable
> > > to just take the strongly-typed __roundup_pow_of_two() helper out of the
> > > loop as below?
> > >
> > > Robin
> > >
> >
> > That looks way better that's for sure. Some questions.
> >
> > > ----->8-----
> > > diff --git a/include/linux/log2.h b/include/linux/log2.h
> > > index 83a4a3ca3e8a..e825f8a6e8b5 100644
> > > --- a/include/linux/log2.h
> > > +++ b/include/linux/log2.h
> > > @@ -172,11 +172,8 @@ unsigned long __rounddown_pow_of_two(unsigned long n)
> > >     */
> > >    #define roundup_pow_of_two(n)			\
> > >    (						\
> > > -	__builtin_constant_p(n) ? (		\
> > > -		(n == 1) ? 1 :			\
> > > -		(1UL << (ilog2((n) - 1) + 1))	\
> > > -				   ) :		\
> > > -	__roundup_pow_of_two(n)			\
> > > +	(__builtin_constant_p(n) && (n == 1)) ?	\
> > > +	1 : (1UL << (ilog2((n) - 1) + 1))	\
> >
> > Then here you'd have to use ULL instead of UL, right? I want my 64bit value
> > everywhere regardless of the CPU arch. The downside is that would affect
> > performance to some extent (i.e. returning a 64bit value where you used to have
> > a 32bit one)?
>
> True, although it's possible that 1ULL might result in the same codegen if
> the compiler can see that the result is immediately truncated back to long
> anyway. Or at worst, I suppose "(typeof(n))1" could suffice, however ugly.
> Either way, this diff was only an illustration rather than a concrete
> proposal, but it might be an interesting diversion to investigate.
>
> On that note, though, you should probably be using ULL in your current patch
> too.
>
> > Also, what about callers to this function on platforms with 32bit 'unsigned
> > longs' that happen to input a 64bit value into this. IIUC we'd have a change of
> > behaviour.
>
> Indeed, although the change in such a case would be "start getting the
> expected value instead of nonsense", so it might very well be welcome ;)

Agree, if code overflowed with 32 bits before this change, the code was already
broken. At least now, it won't overflow.

>
> Robin.

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Re: [PATCH v3 1/7] linux/log2.h: Add roundup/rounddown_pow_two64() family of functions

[Nicolas Saenz Julienne]

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On Wed, 2019-11-27 at 19:06 +0000, Robin Murphy wrote:
> On 27/11/2019 6:24 pm, Nicolas Saenz Julienne wrote:
> > On Wed, 2019-11-27 at 18:06 +0000, Robin Murphy wrote:
> > > On 26/11/2019 12:51 pm, Leon Romanovsky wrote:
> > > > On Tue, Nov 26, 2019 at 10:19:39AM +0100, Nicolas Saenz Julienne wrote:
> > > > > Some users need to make sure their rounding function accepts and
> > > > > returns
> > > > > 64bit long variables regardless of the architecture. Sadly
> > > > > roundup/rounddown_pow_two() takes and returns unsigned longs. Create a
> > > > > new generic 64bit variant of the function and cleanup rougue custom
> > > > > implementations.
> > > > 
> > > > Is it possible to create general roundup/rounddown_pow_two() which will
> > > > work correctly for any type of variables, instead of creating special
> > > > variant for every type?
> > > 
> > > In fact, that is sort of the case already - roundup_pow_of_two() itself
> > > wraps ilog2() such that the constant case *is* type-independent. And
> > > since ilog2() handles non-constant values anyway, might it be reasonable
> > > to just take the strongly-typed __roundup_pow_of_two() helper out of the
> > > loop as below?
> > > 
> > > Robin
> > > 
> > 
> > That looks way better that's for sure. Some questions.
> > 
> > > ----->8-----
> > > diff --git a/include/linux/log2.h b/include/linux/log2.h
> > > index 83a4a3ca3e8a..e825f8a6e8b5 100644
> > > --- a/include/linux/log2.h
> > > +++ b/include/linux/log2.h
> > > @@ -172,11 +172,8 @@ unsigned long __rounddown_pow_of_two(unsigned long n)
> > >     */
> > >    #define roundup_pow_of_two(n)			\
> > >    (						\
> > > -	__builtin_constant_p(n) ? (		\
> > > -		(n == 1) ? 1 :			\
> > > -		(1UL << (ilog2((n) - 1) + 1))	\
> > > -				   ) :		\
> > > -	__roundup_pow_of_two(n)			\
> > > +	(__builtin_constant_p(n) && (n == 1)) ?	\
> > > +	1 : (1UL << (ilog2((n) - 1) + 1))	\
> > 
> > Then here you'd have to use ULL instead of UL, right? I want my 64bit value
> > everywhere regardless of the CPU arch. The downside is that would affect
> > performance to some extent (i.e. returning a 64bit value where you used to
> > have
> > a 32bit one)?
> 
> True, although it's possible that 1ULL might result in the same codegen 
> if the compiler can see that the result is immediately truncated back to 
> long anyway. Or at worst, I suppose "(typeof(n))1" could suffice, 
> however ugly. Either way, this diff was only an illustration rather than 
> a concrete proposal, but it might be an interesting diversion to 
> investigate.
> 
> On that note, though, you should probably be using ULL in your current 
> patch too.

I actually meant to, the fix got lost. Thanks for pointing it out.

As I see Leon also likes this, I'll try out this implementation and come back
with some results.

Regards,
Nicolas


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Re: [PATCH v3 5/7] PCI: brcmstb: add MSI capability

[Andrew Murray]

On Tue, Nov 26, 2019 at 10:19:43AM +0100, Nicolas Saenz Julienne wrote:
> From: Jim Quinlan <james.quinlan@broadcom.com>
> 
> This adds MSI support to the Broadcom STB PCIe host controller. The MSI
> controller is physically located within the PCIe block, however, there
> is no reason why the MSI controller could not be moved elsewhere in the
> future. MSIX is not supported by the HW.
> 
> Since the internal Brcmstb MSI controller is intertwined with the PCIe
> controller, it is not its own platform device but rather part of the
> PCIe platform device.
> 
> Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>
> Co-developed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> Reviewed-by: Marc Zyngier <maz@kernel.org>
> 
> ---
> 
> Changes since v2 (kept Marc's Reviewed-by as changes didn't affect irq
> subsystem stuff or seem petty enough):
>   - Use standard APIs on register operations
>   - Get rid of revision code

Do any RPI4's have a HW revision of less than 33?


>   - Update rules to msi_target_addr selection
>   - Remove unwarranted MSI_FLAG_PCI_MSIX
>   - Small cosmetic changes
> 
> Changes since v1:
>   - Move revision code and some registers to this patch
>   - Use PCIE_MSI_IRQ_DOMAIN in Kconfig
>   - Remove redundant register read from ISR
>   - Fail probe on MSI init error
>   - Get rid of msi_internal
>   - Use bitmap family of functions
>   - Use edge triggered setup
>   - Add comment regarding MultiMSI
>   - Simplify compose_msi_msg to avoid reg read
> 
> This is based on Jim's original submission[1] with some slight changes
> regarding how pcie->msi_target_addr is decided.
> 
> [1] https://patchwork.kernel.org/patch/10605955/
> 
>  drivers/pci/controller/Kconfig        |   1 +
>  drivers/pci/controller/pcie-brcmstb.c | 261 +++++++++++++++++++++++++-
>  2 files changed, 261 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig
> index 27504f108ee5..918e283bbff1 100644


> +
> +static void brcm_msi_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
> +{
> +	struct brcm_msi *msi = irq_data_get_irq_chip_data(data);
> +
> +	msg->address_lo = lower_32_bits(msi->target_addr);
> +	msg->address_hi = upper_32_bits(msi->target_addr);
> +	msg->data = 0x6540 | data->hwirq;

NIT: Perhaps this 0x6540 can be a define - just in the same way we have a define
for PCIE_MISC_MSI_DATA_CONFIG_VAL.

Thanks,

Andrew Murray

> +}
> +
> -- 
> 2.24.0
> 

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Re: [PATCH v3 5/7] PCI: brcmstb: add MSI capability

[Nicolas Saenz Julienne]

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Hi Andrew,

On Fri, 2019-11-29 at 15:46 +0000, Andrew Murray wrote:
> On Tue, Nov 26, 2019 at 10:19:43AM +0100, Nicolas Saenz Julienne wrote:
> > From: Jim Quinlan <james.quinlan@broadcom.com>
> > 
> > This adds MSI support to the Broadcom STB PCIe host controller. The MSI
> > controller is physically located within the PCIe block, however, there
> > is no reason why the MSI controller could not be moved elsewhere in the
> > future. MSIX is not supported by the HW.
> > 
> > Since the internal Brcmstb MSI controller is intertwined with the PCIe
> > controller, it is not its own platform device but rather part of the
> > PCIe platform device.
> > 
> > Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>
> > Co-developed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> > Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> > Reviewed-by: Marc Zyngier <maz@kernel.org>
> > 
> > ---
> > 
> > Changes since v2 (kept Marc's Reviewed-by as changes didn't affect irq
> > subsystem stuff or seem petty enough):
> >   - Use standard APIs on register operations
> >   - Get rid of revision code
> 
> Do any RPI4's have a HW revision of less than 33?

No, IIRC it's actually revision 34. I had left that bit of code in, following
the same train of thought as with the of_data on the device-tree part of the
driver: "It's harmless and should make accomodating other devices easier." It
turned out not to be such a great approach. Lesson's learned. So I decided to
remove it.

> >   - Update rules to msi_target_addr selection
> >   - Remove unwarranted MSI_FLAG_PCI_MSIX
> >   - Small cosmetic changes
> > 
> > Changes since v1:cuando tenías tu vacaciones?
> >   - Move revision code and some registers to this patch
> >   - Use PCIE_MSI_IRQ_DOMAIN in Kconfig
> >   - Remove redundant register read from ISR
> >   - Fail probe on MSI init error
> >   - Get rid of msi_internal
> >   - Use bitmap family of functions
> >   - Use edge triggered setup
> >   - Add comment regarding MultiMSI
> >   - Simplify compose_msi_msg to avoid reg read
> > 
> > This is based on Jim's original submission[1] with some slight changes
> > regarding how pcie->msi_target_addr is decided.
> > 
> > [1] https://patchwork.kernel.org/patch/10605955/
> > 
> >  drivers/pci/controller/Kconfig        |   1 +
> >  drivers/pci/controller/pcie-brcmstb.c | 261 +++++++++++++++++++++++++-
> >  2 files changed, 261 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig
> > index 27504f108ee5..918e283bbff1 100644
> > +
> > +static void brcm_msi_compose_msi_msg(struct irq_data *data, struct msi_msg
> > *msg)
> > +{
> > +	struct brcm_msi *msi = irq_data_get_irq_chip_data(data);
> > +
> > +	msg->address_lo = lower_32_bits(msi->target_addr);
> > +	msg->address_hi = upper_32_bits(msi->target_addr);
> > +	msg->data = 0x6540 | data->hwirq;
> 
> NIT: Perhaps this 0x6540 can be a define - just in the same way we have a
> define
> for PCIE_MISC_MSI_DATA_CONFIG_VAL.

Noted

Regards,
Nicolas


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Re: [PATCH v3 5/7] PCI: brcmstb: add MSI capability

[Andrew Murray]

On Mon, Dec 02, 2019 at 10:59:36AM +0100, Nicolas Saenz Julienne wrote:
> Hi Andrew,
> 
> On Fri, 2019-11-29 at 15:46 +0000, Andrew Murray wrote:
> > On Tue, Nov 26, 2019 at 10:19:43AM +0100, Nicolas Saenz Julienne wrote:
> > > From: Jim Quinlan <james.quinlan@broadcom.com>
> > > 
> > > This adds MSI support to the Broadcom STB PCIe host controller. The MSI
> > > controller is physically located within the PCIe block, however, there
> > > is no reason why the MSI controller could not be moved elsewhere in the
> > > future. MSIX is not supported by the HW.
> > > 
> > > Since the internal Brcmstb MSI controller is intertwined with the PCIe
> > > controller, it is not its own platform device but rather part of the
> > > PCIe platform device.
> > > 
> > > Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>
> > > Co-developed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> > > Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> > > Reviewed-by: Marc Zyngier <maz@kernel.org>
> > > 
> > > ---
> > > 
> > > Changes since v2 (kept Marc's Reviewed-by as changes didn't affect irq
> > > subsystem stuff or seem petty enough):
> > >   - Use standard APIs on register operations
> > >   - Get rid of revision code
> > 
> > Do any RPI4's have a HW revision of less than 33?
> 
> No, IIRC it's actually revision 34. I had left that bit of code in, following
> the same train of thought as with the of_data on the device-tree part of the
> driver: "It's harmless and should make accomodating other devices easier." It
> turned out not to be such a great approach. Lesson's learned. So I decided to
> remove it.

OK you can add my:

Reviewed-by: Andrew Murray <andrew.murray@arm.com>

Thanks,

Andrew Murray

> 
> > >   - Update rules to msi_target_addr selection
> > >   - Remove unwarranted MSI_FLAG_PCI_MSIX
> > >   - Small cosmetic changes
> > > 
> > > Changes since v1:cuando tenías tu vacaciones?
> > >   - Move revision code and some registers to this patch
> > >   - Use PCIE_MSI_IRQ_DOMAIN in Kconfig
> > >   - Remove redundant register read from ISR
> > >   - Fail probe on MSI init error
> > >   - Get rid of msi_internal
> > >   - Use bitmap family of functions
> > >   - Use edge triggered setup
> > >   - Add comment regarding MultiMSI
> > >   - Simplify compose_msi_msg to avoid reg read
> > > 
> > > This is based on Jim's original submission[1] with some slight changes
> > > regarding how pcie->msi_target_addr is decided.
> > > 
> > > [1] https://patchwork.kernel.org/patch/10605955/
> > > 
> > >  drivers/pci/controller/Kconfig        |   1 +
> > >  drivers/pci/controller/pcie-brcmstb.c | 261 +++++++++++++++++++++++++-
> > >  2 files changed, 261 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig
> > > index 27504f108ee5..918e283bbff1 100644
> > > +
> > > +static void brcm_msi_compose_msi_msg(struct irq_data *data, struct msi_msg
> > > *msg)
> > > +{
> > > +	struct brcm_msi *msi = irq_data_get_irq_chip_data(data);
> > > +
> > > +	msg->address_lo = lower_32_bits(msi->target_addr);
> > > +	msg->address_hi = upper_32_bits(msi->target_addr);
> > > +	msg->data = 0x6540 | data->hwirq;
> > 
> > NIT: Perhaps this 0x6540 can be a define - just in the same way we have a
> > define
> > for PCIE_MISC_MSI_DATA_CONFIG_VAL.
> 
> Noted
> 
> Regards,
> Nicolas
> 



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Re: [PATCH v3 5/7] PCI: brcmstb: add MSI capability

[Nicolas Saenz Julienne]

[-- Attachment #1.1: Type: text/plain, Size: 1943 bytes --]

On Mon, 2019-12-02 at 12:20 +0000, Andrew Murray wrote:
> On Mon, Dec 02, 2019 at 10:59:36AM +0100, Nicolas Saenz Julienne wrote:
> > Hi Andrew,
> > 
> > On Fri, 2019-11-29 at 15:46 +0000, Andrew Murray wrote:
> > > On Tue, Nov 26, 2019 at 10:19:43AM +0100, Nicolas Saenz Julienne wrote:
> > > > From: Jim Quinlan <james.quinlan@broadcom.com>
> > > > 
> > > > This adds MSI support to the Broadcom STB PCIe host controller. The MSI
> > > > controller is physically located within the PCIe block, however, there
> > > > is no reason why the MSI controller could not be moved elsewhere in the
> > > > future. MSIX is not supported by the HW.
> > > > 
> > > > Since the internal Brcmstb MSI controller is intertwined with the PCIe
> > > > controller, it is not its own platform device but rather part of the
> > > > PCIe platform device.
> > > > 
> > > > Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>
> > > > Co-developed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> > > > Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> > > > Reviewed-by: Marc Zyngier <maz@kernel.org>
> > > > 
> > > > ---
> > > > 
> > > > Changes since v2 (kept Marc's Reviewed-by as changes didn't affect irq
> > > > subsystem stuff or seem petty enough):
> > > >   - Use standard APIs on register operations
> > > >   - Get rid of revision code
> > > 
> > > Do any RPI4's have a HW revision of less than 33?
> > 
> > No, IIRC it's actually revision 34. I had left that bit of code in,
> > following
> > the same train of thought as with the of_data on the device-tree part of the
> > driver: "It's harmless and should make accomodating other devices easier."
> > It
> > turned out not to be such a great approach. Lesson's learned. So I decided
> > to
> > remove it.
> 
> OK you can add my:
> 
> Reviewed-by: Andrew Murray <andrew.murray@arm.com>
> 
> Thanks,
> 
> Andrew Murray

Thanks!


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Re: [PATCH v3 4/7] PCI: brcmstb: add Broadcom STB PCIe host controller driver

[Andrew Murray]

On Tue, Nov 26, 2019 at 10:19:42AM +0100, Nicolas Saenz Julienne wrote:
> From: Jim Quinlan <james.quinlan@broadcom.com>

Nit: Capitalise the 'a' in 'add Broadcom STB...' in the subject.


> 
> This adds a basic driver for Broadcom's STB PCIe controller, for now
> aimed at Raspberry Pi 4's SoC, bcm2711.
> 
> Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>
> Co-developed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> 
> ---
> 
> Changes since v2:
>   - Correct rc_bar2_offset sign
>   - Invert IRQ clear and masking in setup code
>   - Use bitfield.h, redo all register ops while keeping the register
>     names intact
>   - Remove all SHIFT register definitions
>   - Get rid of all _RB writes
>   - Get rid of of_data
>   - Don't iterate over inexisting dma-ranges
>   - Add comment regarding dma-ranges validation
>   - Small cosmetic cleanups
>   - Fix license mismatch
>   - Set driver Kconfig tristate
>   - Didn't add any comment about the controller not being I/O coherent
>     for now as I wait for Jeremy's reply
> 
> Changes since v1:
>   - Fix Kconfig
>   - Remove pci domain check
>   - Remove all MSI related code
>   - Remove supend/resume code
>   - Simplify link state wait routine
>   - Prefix all functions
>   - Use of_device_get_match_data()
>   - Use devm_clk_get_optional()
>   - Get rid of irq variable
>   - Use STB all over the driver
>   - Simplify map_bus() function
>   - Fix license mismatch
>   - Remove unused register definitions
>   - Small cleanups, spell errors
> 
> This is based on Jim's original submission[1] but adapted and tailored
> specifically to bcm2711's needs (that's the Raspberry Pi 4). Support for
> the rest of the brcmstb family will soon follow once we get support for
> multiple dma-ranges in dma/direct.
> 
> [1] https://patchwork.kernel.org/patch/10605959/
> 
>  drivers/pci/controller/Kconfig        |   8 +
>  drivers/pci/controller/Makefile       |   1 +
>  drivers/pci/controller/pcie-brcmstb.c | 753 ++++++++++++++++++++++++++
>  3 files changed, 762 insertions(+)
>  create mode 100644 drivers/pci/controller/pcie-brcmstb.c
> 
> diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig
> index c77069c8ee5d..27504f108ee5 100644
> --- a/drivers/pci/controller/Kconfig
> +++ b/drivers/pci/controller/Kconfig
> @@ -253,6 +253,14 @@ config VMD
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called vmd.
>  
> +config PCIE_BRCMSTB
> +	tristate "Broadcom Brcmstb PCIe host controller"
> +	depends on ARCH_BCM2835 || COMPILE_TEST
> +	depends on OF
> +	help
> +	  Say Y here to enable PCIe host controller support for
> +	  Broadcom STB based SoCs, like the Raspberry Pi 4.
> +
>  config PCI_HYPERV_INTERFACE
>  	tristate "Hyper-V PCI Interface"
>  	depends on X86 && HYPERV && PCI_MSI && PCI_MSI_IRQ_DOMAIN && X86_64
> diff --git a/drivers/pci/controller/Makefile b/drivers/pci/controller/Makefile
> index 3d4f597f15ce..01b2502a5323 100644
> --- a/drivers/pci/controller/Makefile
> +++ b/drivers/pci/controller/Makefile
> @@ -28,6 +28,7 @@ obj-$(CONFIG_PCIE_MEDIATEK) += pcie-mediatek.o
>  obj-$(CONFIG_PCIE_MOBIVEIL) += pcie-mobiveil.o
>  obj-$(CONFIG_PCIE_TANGO_SMP8759) += pcie-tango.o
>  obj-$(CONFIG_VMD) += vmd.o
> +obj-$(CONFIG_PCIE_BRCMSTB) += pcie-brcmstb.o
>  # pcie-hisi.o quirks are needed even without CONFIG_PCIE_DW
>  obj-y				+= dwc/
>  
> diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
> new file mode 100644
> index 000000000000..28c1b9429d3d
> --- /dev/null
> +++ b/drivers/pci/controller/pcie-brcmstb.c
> @@ -0,0 +1,753 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/* Copyright (C) 2009 - 2019 Broadcom */
> +
> +#include <linux/bitfield.h>
> +#include <linux/clk.h>
> +#include <linux/compiler.h>
> +#include <linux/delay.h>
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/ioport.h>
> +#include <linux/irqdomain.h>
> +#include <linux/kernel.h>
> +#include <linux/list.h>
> +#include <linux/log2.h>
> +#include <linux/module.h>
> +#include <linux/of_address.h>
> +#include <linux/of_irq.h>
> +#include <linux/of_pci.h>
> +#include <linux/of_platform.h>
> +#include <linux/pci.h>
> +#include <linux/printk.h>
> +#include <linux/sizes.h>
> +#include <linux/slab.h>
> +#include <linux/string.h>
> +#include <linux/types.h>
> +
> +#include "../pci.h"
> +
> +/* BRCM_PCIE_CAP_REGS - Offset for the mandatory capability config regs */

NIT: You can probably rephrase this from "BRCM_PCIE_CAP_REGS - Offset for ..." to "Offset for ..."


> +#define BRCM_PCIE_CAP_REGS				0x00ac
> +
> +/*
> + * Broadcom STB PCIe Register Offsets. The names are from the chip's RDB and we
> + * use them here so that a script can correlate this code and the RDB to
> + * prevent discrepancies.

What is RDB? Is the script public? Do other Broadcom drivers in the kernel take
this approach (if not then why do something different here?).

Unless anyone with the kernel source can benefit from any of this then it's
likely to not provide any value - and instead just result in the naming of the
registers not consistent with the rest of the kernel.

In any case I don't have a problem with the register names, so I'd suggest you
just drop the comment.

With those you can add:

Reviewed-by: Andrew Murray <andrew.murray@arm.com>

> + */
> +#define PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1				0x0188
> +#define  PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1_ENDIAN_MODE_BAR2_MASK	0xc
> +#define  PCIE_RC_CFG_VENDOR_SPCIFIC_REG1_LITTLE_ENDIAN			0x0
> +
> +#define PCIE_RC_CFG_PRIV1_ID_VAL3			0x043c
> +#define  PCIE_RC_CFG_PRIV1_ID_VAL3_CLASS_CODE_MASK	0xffffff
> +
> +#define PCIE_RC_DL_MDIO_ADDR				0x1100
> +#define PCIE_RC_DL_MDIO_WR_DATA				0x1104
> +#define PCIE_RC_DL_MDIO_RD_DATA				0x1108
> +
> +#define PCIE_MISC_MISC_CTRL				0x4008
> +#define  PCIE_MISC_MISC_CTRL_SCB_ACCESS_EN_MASK		0x1000
> +#define  PCIE_MISC_MISC_CTRL_CFG_READ_UR_MODE_MASK	0x2000
> +#define  PCIE_MISC_MISC_CTRL_MAX_BURST_SIZE_MASK	0x300000
> +#define  PCIE_MISC_MISC_CTRL_MAX_BURST_SIZE_128		0x0
> +#define  PCIE_MISC_MISC_CTRL_SCB0_SIZE_MASK		0xf8000000
> +
> +#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LO		0x400c
> +#define PCIE_MEM_WIN0_LO(win)	\
> +		PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LO + ((win) * 4)
> +
> +#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_HI		0x4010
> +#define PCIE_MEM_WIN0_HI(win)	\
> +		PCIE_MISC_CPU_2_PCIE_MEM_WIN0_HI + ((win) * 4)
> +
> +#define PCIE_MISC_RC_BAR1_CONFIG_LO			0x402c
> +#define  PCIE_MISC_RC_BAR1_CONFIG_LO_SIZE_MASK		0x1f
> +
> +#define PCIE_MISC_RC_BAR2_CONFIG_LO			0x4034
> +#define  PCIE_MISC_RC_BAR2_CONFIG_LO_SIZE_MASK		0x1f
> +#define PCIE_MISC_RC_BAR2_CONFIG_HI			0x4038
> +
> +#define PCIE_MISC_RC_BAR3_CONFIG_LO			0x403c
> +#define  PCIE_MISC_RC_BAR3_CONFIG_LO_SIZE_MASK		0x1f
> +
> +#define PCIE_MISC_PCIE_CTRL				0x4064
> +#define  PCIE_MISC_PCIE_CTRL_PCIE_L23_REQUEST_MASK	0x1
> +
> +#define PCIE_MISC_PCIE_STATUS				0x4068
> +#define  PCIE_MISC_PCIE_STATUS_PCIE_PORT_MASK		0x80
> +#define  PCIE_MISC_PCIE_STATUS_PCIE_DL_ACTIVE_MASK	0x20
> +#define  PCIE_MISC_PCIE_STATUS_PCIE_PHYLINKUP_MASK	0x10
> +#define  PCIE_MISC_PCIE_STATUS_PCIE_LINK_IN_L23_MASK	0x40
> +
> +#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT		0x4070
> +#define  PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_LIMIT_MASK	0xfff00000
> +#define  PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_BASE_MASK	0xfff0
> +#define PCIE_MEM_WIN0_BASE_LIMIT(win)	\
> +		PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT + ((win) * 4)
> +
> +#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_HI			0x4080
> +#define  PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_HI_BASE_MASK	0xff
> +#define PCIE_MEM_WIN0_BASE_HI(win)	\
> +		PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_HI + ((win) * 8)
> +
> +#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LIMIT_HI			0x4084
> +#define  PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LIMIT_HI_LIMIT_MASK	0xff
> +#define PCIE_MEM_WIN0_LIMIT_HI(win)	\
> +		PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LIMIT_HI + ((win) * 8)
> +
> +#define PCIE_MISC_HARD_PCIE_HARD_DEBUG					0x4204
> +#define  PCIE_MISC_HARD_PCIE_HARD_DEBUG_CLKREQ_DEBUG_ENABLE_MASK	0x2
> +#define  PCIE_MISC_HARD_PCIE_HARD_DEBUG_SERDES_IDDQ_MASK		0x08000000
> +
> +#define PCIE_MSI_INTR2_STATUS				0x4500
> +#define PCIE_MSI_INTR2_CLR				0x4508
> +#define PCIE_MSI_INTR2_MASK_SET				0x4510
> +#define PCIE_MSI_INTR2_MASK_CLR				0x4514
> +
> +#define PCIE_EXT_CFG_DATA				0x8000
> +
> +#define PCIE_EXT_CFG_INDEX				0x9000
> +#define  PCIE_EXT_BUSNUM_SHIFT				20
> +#define  PCIE_EXT_SLOT_SHIFT				15
> +#define  PCIE_EXT_FUNC_SHIFT				12
> +
> +#define PCIE_RGR1_SW_INIT_1				0x9210
> +#define  PCIE_RGR1_SW_INIT_1_PERST_MASK			0x1
> +#define  PCIE_RGR1_SW_INIT_1_INIT_MASK			0x2
> +
> +/* PCIe parameters */
> +#define BRCM_NUM_PCIE_OUT_WINS		0x4
> +
> +/* MDIO registers */
> +#define MDIO_PORT0			0x0
> +#define MDIO_DATA_MASK			0x7fffffff
> +#define MDIO_PORT_MASK			0xf0000
> +#define MDIO_REGAD_MASK			0xffff
> +#define MDIO_CMD_MASK			0xfff00000
> +#define MDIO_CMD_READ			0x1
> +#define MDIO_CMD_WRITE			0x0
> +#define MDIO_DATA_DONE_MASK		0x80000000
> +#define MDIO_RD_DONE(x)			(((x) & MDIO_DATA_DONE_MASK) ? 1 : 0)
> +#define MDIO_WT_DONE(x)			(((x) & MDIO_DATA_DONE_MASK) ? 0 : 1)
> +#define SSC_REGS_ADDR			0x1100
> +#define SET_ADDR_OFFSET			0x1f
> +#define SSC_CNTL_OFFSET			0x2
> +#define SSC_CNTL_OVRD_EN_MASK		0x8000
> +#define SSC_CNTL_OVRD_VAL_MASK		0x4000
> +#define SSC_STATUS_OFFSET		0x1
> +#define SSC_STATUS_SSC_MASK		0x400
> +#define SSC_STATUS_PLL_LOCK_MASK	0x800
> +
> +/* Internal PCIe Host Controller Information.*/
> +struct brcm_pcie {
> +	struct device		*dev;
> +	void __iomem		*base;
> +	struct clk		*clk;
> +	struct pci_bus		*root_bus;
> +	struct device_node	*np;
> +	bool			ssc;
> +	int			gen;
> +};
> +
> +/*
> + * This is to convert the size of the inbound "BAR" region to the
> + * non-linear values of PCIE_X_MISC_RC_BAR[123]_CONFIG_LO.SIZE
> + */
> +static int brcm_pcie_encode_ibar_size(u64 size)
> +{
> +	int log2_in = ilog2(size);
> +
> +	if (log2_in >= 12 && log2_in <= 15)
> +		/* Covers 4KB to 32KB (inclusive) */
> +		return (log2_in - 12) + 0x1c;
> +	else if (log2_in >= 16 && log2_in <= 35)
> +		/* Covers 64KB to 32GB, (inclusive) */
> +		return log2_in - 15;
> +	/* Something is awry so disable */
> +	return 0;
> +}
> +
> +static u32 brcm_pcie_mdio_form_pkt(int port, int regad, int cmd)
> +{
> +	u32 pkt = 0;
> +
> +	pkt |= FIELD_PREP(MDIO_PORT_MASK, port);
> +	pkt |= FIELD_PREP(MDIO_REGAD_MASK, regad);
> +	pkt |= FIELD_PREP(MDIO_CMD_MASK, cmd);
> +
> +	return pkt;
> +}
> +
> +/* negative return value indicates error */
> +static int brcm_pcie_mdio_read(void __iomem *base, u8 port, u8 regad, u32 *val)
> +{
> +	int tries;
> +	u32 data;
> +
> +	writel(brcm_pcie_mdio_form_pkt(port, regad, MDIO_CMD_READ),
> +		   base + PCIE_RC_DL_MDIO_ADDR);
> +	readl(base + PCIE_RC_DL_MDIO_ADDR);
> +
> +	data = readl(base + PCIE_RC_DL_MDIO_RD_DATA);
> +	for (tries = 0; !MDIO_RD_DONE(data) && tries < 10; tries++) {
> +		udelay(10);
> +		data = readl(base + PCIE_RC_DL_MDIO_RD_DATA);
> +	}
> +
> +	*val = FIELD_GET(MDIO_DATA_MASK, data);
> +	return MDIO_RD_DONE(data) ? 0 : -EIO;
> +}
> +
> +/* negative return value indicates error */
> +static int brcm_pcie_mdio_write(void __iomem *base, u8 port,
> +				u8 regad, u16 wrdata)
> +{
> +	int tries;
> +	u32 data;
> +
> +	writel(brcm_pcie_mdio_form_pkt(port, regad, MDIO_CMD_WRITE),
> +		   base + PCIE_RC_DL_MDIO_ADDR);
> +	readl(base + PCIE_RC_DL_MDIO_ADDR);
> +	writel(MDIO_DATA_DONE_MASK | wrdata, base + PCIE_RC_DL_MDIO_WR_DATA);
> +
> +	data = readl(base + PCIE_RC_DL_MDIO_WR_DATA);
> +	for (tries = 0; !MDIO_WT_DONE(data) && tries < 10; tries++) {
> +		udelay(10);
> +		data = readl(base + PCIE_RC_DL_MDIO_WR_DATA);
> +	}
> +
> +	return MDIO_WT_DONE(data) ? 0 : -EIO;
> +}
> +
> +/*
> + * Configures device for Spread Spectrum Clocking (SSC) mode; a negative
> + * return value indicates error.
> + */
> +static int brcm_pcie_set_ssc(struct brcm_pcie *pcie)
> +{
> +	int pll, ssc;
> +	int ret;
> +	u32 tmp;
> +
> +	ret = brcm_pcie_mdio_write(pcie->base, MDIO_PORT0, SET_ADDR_OFFSET,
> +				   SSC_REGS_ADDR);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = brcm_pcie_mdio_read(pcie->base, MDIO_PORT0,
> +				  SSC_CNTL_OFFSET, &tmp);
> +	if (ret < 0)
> +		return ret;
> +
> +	u32p_replace_bits(&tmp, 1, SSC_CNTL_OVRD_EN_MASK);
> +	u32p_replace_bits(&tmp, 1, SSC_CNTL_OVRD_VAL_MASK);
> +	ret = brcm_pcie_mdio_write(pcie->base, MDIO_PORT0,
> +				   SSC_CNTL_OFFSET, tmp);
> +	if (ret < 0)
> +		return ret;
> +
> +	usleep_range(1000, 2000);
> +	ret = brcm_pcie_mdio_read(pcie->base, MDIO_PORT0,
> +				  SSC_STATUS_OFFSET, &tmp);
> +	if (ret < 0)
> +		return ret;
> +
> +	ssc = FIELD_GET(SSC_STATUS_SSC_MASK, tmp);
> +	pll = FIELD_GET(SSC_STATUS_PLL_LOCK_MASK, tmp);
> +
> +	return ssc && pll ? 0 : -EIO;
> +}
> +
> +/* Limits operation to a specific generation (1, 2, or 3) */
> +static void brcm_pcie_set_gen(struct brcm_pcie *pcie, int gen)
> +{
> +	u16 lnkctl2 = readw(pcie->base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKCTL2);
> +	u32 lnkcap = readl(pcie->base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKCAP);
> +
> +	lnkcap = (lnkcap & ~PCI_EXP_LNKCAP_SLS) | gen;
> +	writel(lnkcap, pcie->base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKCAP);
> +
> +	lnkctl2 = (lnkctl2 & ~0xf) | gen;
> +	writew(lnkctl2, pcie->base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKCTL2);
> +}
> +
> +static void brcm_pcie_set_outbound_win(struct brcm_pcie *pcie,
> +				       unsigned int win, u64 cpu_addr,
> +				       u64 pcie_addr, u64 size)
> +{
> +	u32 cpu_addr_mb_high, limit_addr_mb_high;
> +	phys_addr_t cpu_addr_mb, limit_addr_mb;
> +	int high_addr_shift;
> +	u32 tmp;
> +
> +	/* Set the base of the pcie_addr window */
> +	writel(lower_32_bits(pcie_addr), pcie->base + PCIE_MEM_WIN0_LO(win));
> +	writel(upper_32_bits(pcie_addr), pcie->base + PCIE_MEM_WIN0_HI(win));
> +
> +	/* Write the addr base & limit lower bits (in MBs) */
> +	cpu_addr_mb = cpu_addr / SZ_1M;
> +	limit_addr_mb = (cpu_addr + size - 1) / SZ_1M;
> +
> +	tmp = readl(pcie->base + PCIE_MEM_WIN0_BASE_LIMIT(win));
> +	u32p_replace_bits(&tmp, cpu_addr_mb,
> +			  PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_BASE_MASK);
> +	u32p_replace_bits(&tmp, limit_addr_mb,
> +			  PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_LIMIT_MASK);
> +	writel(tmp, pcie->base + PCIE_MEM_WIN0_BASE_LIMIT(win));
> +
> +	/* Write the cpu & limit addr upper bits */
> +	high_addr_shift =
> +		HWEIGHT32(PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_BASE_MASK);
> +
> +	cpu_addr_mb_high = cpu_addr_mb >> high_addr_shift;
> +	tmp = readl(pcie->base + PCIE_MEM_WIN0_BASE_HI(win));
> +	u32p_replace_bits(&tmp, cpu_addr_mb_high,
> +			  PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_HI_BASE_MASK);
> +	writel(tmp, pcie->base + PCIE_MEM_WIN0_BASE_HI(win));
> +
> +	limit_addr_mb_high = limit_addr_mb >> high_addr_shift;
> +	tmp = readl(pcie->base + PCIE_MEM_WIN0_LIMIT_HI(win));
> +	u32p_replace_bits(&tmp, limit_addr_mb_high,
> +			  PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LIMIT_HI_LIMIT_MASK);
> +	writel(tmp, pcie->base + PCIE_MEM_WIN0_LIMIT_HI(win));
> +}
> +
> +/* The controller is capable of serving in both RC and EP roles */
> +static bool brcm_pcie_rc_mode(struct brcm_pcie *pcie)
> +{
> +	void __iomem *base = pcie->base;
> +	u32 val = readl(base + PCIE_MISC_PCIE_STATUS);
> +
> +	return !!FIELD_GET(PCIE_MISC_PCIE_STATUS_PCIE_PORT_MASK, val);
> +}
> +
> +static bool brcm_pcie_link_up(struct brcm_pcie *pcie)
> +{
> +	u32 val = readl(pcie->base + PCIE_MISC_PCIE_STATUS);
> +	u32 dla = FIELD_GET(PCIE_MISC_PCIE_STATUS_PCIE_DL_ACTIVE_MASK, val);
> +	u32 plu = FIELD_GET(PCIE_MISC_PCIE_STATUS_PCIE_PHYLINKUP_MASK, val);
> +
> +	return dla && plu;
> +}
> +
> +/* Configuration space read/write support */
> +static inline int brcm_pcie_cfg_index(int busnr, int devfn, int reg)
> +{
> +	return ((PCI_SLOT(devfn) & 0x1f) << PCIE_EXT_SLOT_SHIFT)
> +		| ((PCI_FUNC(devfn) & 0x07) << PCIE_EXT_FUNC_SHIFT)
> +		| (busnr << PCIE_EXT_BUSNUM_SHIFT)
> +		| (reg & ~3);
> +}
> +
> +static void __iomem *brcm_pcie_map_conf(struct pci_bus *bus, unsigned int devfn,
> +					int where)
> +{
> +	struct brcm_pcie *pcie = bus->sysdata;
> +	void __iomem *base = pcie->base;
> +	int idx;
> +
> +	/* Accesses to the RC go right to the RC registers if slot==0 */
> +	if (pci_is_root_bus(bus))
> +		return PCI_SLOT(devfn) ? NULL : base + where;
> +
> +	/* For devices, write to the config space index register */
> +	idx = brcm_pcie_cfg_index(bus->number, devfn, 0);
> +	writel(idx, pcie->base + PCIE_EXT_CFG_INDEX);
> +	return base + PCIE_EXT_CFG_DATA + where;
> +}
> +
> +static struct pci_ops brcm_pcie_ops = {
> +	.map_bus = brcm_pcie_map_conf,
> +	.read = pci_generic_config_read,
> +	.write = pci_generic_config_write,
> +};
> +
> +static inline void brcm_pcie_bridge_sw_init_set(struct brcm_pcie *pcie, u32 val)
> +{
> +	u32 tmp;
> +
> +	tmp = readl(pcie->base + PCIE_RGR1_SW_INIT_1);
> +	u32p_replace_bits(&tmp, val, PCIE_RGR1_SW_INIT_1_INIT_MASK);
> +	writel(tmp, pcie->base + PCIE_RGR1_SW_INIT_1);
> +}
> +
> +static inline void brcm_pcie_perst_set(struct brcm_pcie *pcie, u32 val)
> +{
> +	u32 tmp;
> +
> +	tmp = readl(pcie->base + PCIE_RGR1_SW_INIT_1);
> +	u32p_replace_bits(&tmp, val, PCIE_RGR1_SW_INIT_1_PERST_MASK);
> +	writel(tmp, pcie->base + PCIE_RGR1_SW_INIT_1);
> +}
> +
> +static inline int brcm_pcie_get_rc_bar2_size_and_offset(struct brcm_pcie *pcie,
> +							u64 *rc_bar2_size,
> +							u64 *rc_bar2_offset)
> +{
> +	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
> +	struct device *dev = pcie->dev;
> +	struct resource_entry *entry;
> +
> +	entry = resource_list_first_type(&bridge->dma_ranges, IORESOURCE_MEM);
> +	if (!entry)
> +		return -ENODEV;
> +
> +	*rc_bar2_offset = -entry->offset;
> +	*rc_bar2_size = roundup_pow_of_two_u64(entry->res->end -
> +					       entry->res->start + 1);
> +
> +	/*
> +	 * We validate the inbound memory view even though we should trust
> +	 * whatever the device-tree provides. This is because of an HW issue on
> +	 * early Raspberry Pi 4's revisions (bcm2711). It turns out its
> +	 * firmware has to dynamically edit dma-ranges due to a bug on the
> +	 * PCIe controller integration, which prohibits any access above the
> +	 * lower 3GB of memory. Given this, we decided to keep the dma-ranges
> +	 * in check, avoiding hard to debug device-tree related issues in the
> +	 * future:
> +	 *
> +	 * The PCIe host controller by design must set the inbound viewport to
> +	 * be a contiguous arrangement of all of the system's memory.  In
> +	 * addition, its size mut be a power of two.  To further complicate
> +	 * matters, the viewport must start on a pcie-address that is aligned
> +	 * on a multiple of its size.  If a portion of the viewport does not
> +	 * represent system memory -- e.g. 3GB of memory requires a 4GB
> +	 * viewport -- we can map the outbound memory in or after 3GB and even
> +	 * though the viewport will overlap the outbound memory the controller
> +	 * will know to send outbound memory downstream and everything else
> +	 * upstream.
> +	 *
> +	 * For example:
> +	 *
> +	 * - The best-case scenario, memory up to 3GB, is to place the inbound
> +	 *   region in the first 4GB of pcie-space, as some legacy devices can
> +	 *   only address 32bits. We would also like to put the MSI under 4GB
> +	 *   as well, since some devices require a 32bit MSI target address.
> +	 *
> +	 * - If the system memory is 4GB or larger we cannot start the inbound
> +	 *   region at location 0 (since we have to allow some space for
> +	 *   outbound memory @ 3GB). So instead it will  start at the 1x
> +	 *   multiple of its size
> +	 */
> +	if (!*rc_bar2_size || *rc_bar2_offset % *rc_bar2_size ||
> +	    (*rc_bar2_offset < SZ_4G && *rc_bar2_offset > SZ_2G)) {
> +		dev_err(dev, "Invalid rc_bar2_offset/size: size 0x%llx, off 0x%llx\n",
> +			*rc_bar2_size, *rc_bar2_offset);
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static int brcm_pcie_setup(struct brcm_pcie *pcie)
> +{
> +	struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
> +	u64 rc_bar2_offset, rc_bar2_size;
> +	void __iomem *base = pcie->base;
> +	struct device *dev = pcie->dev;
> +	struct resource_entry *entry;
> +	unsigned int scb_size_val;
> +	bool ssc_good = false;
> +	struct resource *res;
> +	int num_out_wins = 0;
> +	u16 nlw, cls, lnksta;
> +	int i, ret;
> +	u32 tmp;
> +
> +	/* Reset the bridge */
> +	brcm_pcie_bridge_sw_init_set(pcie, 1);
> +
> +	usleep_range(100, 200);
> +
> +	/* Take the bridge out of reset */
> +	brcm_pcie_bridge_sw_init_set(pcie, 0);
> +
> +	tmp = readl(base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
> +	tmp &= ~PCIE_MISC_HARD_PCIE_HARD_DEBUG_SERDES_IDDQ_MASK;
> +	writel(tmp, base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
> +	/* Wait for SerDes to be stable */
> +	usleep_range(100, 200);
> +
> +	/* Set SCB_MAX_BURST_SIZE, CFG_READ_UR_MODE, SCB_ACCESS_EN */
> +	u32p_replace_bits(&tmp, 1, PCIE_MISC_MISC_CTRL_SCB_ACCESS_EN_MASK);
> +	u32p_replace_bits(&tmp, 1, PCIE_MISC_MISC_CTRL_CFG_READ_UR_MODE_MASK);
> +	u32p_replace_bits(&tmp, PCIE_MISC_MISC_CTRL_MAX_BURST_SIZE_128,
> +			  PCIE_MISC_MISC_CTRL_MAX_BURST_SIZE_MASK);
> +	writel(tmp, base + PCIE_MISC_MISC_CTRL);
> +
> +	ret = brcm_pcie_get_rc_bar2_size_and_offset(pcie, &rc_bar2_size,
> +						    &rc_bar2_offset);
> +	if (ret)
> +		return ret;
> +
> +	tmp = lower_32_bits(rc_bar2_offset);
> +	u32p_replace_bits(&tmp, brcm_pcie_encode_ibar_size(rc_bar2_size),
> +			  PCIE_MISC_RC_BAR2_CONFIG_LO_SIZE_MASK);
> +	writel(tmp, base + PCIE_MISC_RC_BAR2_CONFIG_LO);
> +	writel(upper_32_bits(rc_bar2_offset),
> +	       base + PCIE_MISC_RC_BAR2_CONFIG_HI);
> +
> +	scb_size_val = rc_bar2_size ?
> +		       ilog2(rc_bar2_size) - 15 : 0xf; /* 0xf is 1GB */
> +	tmp = readl(base + PCIE_MISC_MISC_CTRL);
> +	u32p_replace_bits(&tmp, scb_size_val,
> +			  PCIE_MISC_MISC_CTRL_SCB0_SIZE_MASK);
> +	writel(tmp, base + PCIE_MISC_MISC_CTRL);
> +
> +	/* disable the PCIe->GISB memory window (RC_BAR1) */
> +	tmp = readl(base + PCIE_MISC_RC_BAR1_CONFIG_LO);
> +	tmp &= ~PCIE_MISC_RC_BAR1_CONFIG_LO_SIZE_MASK;
> +	writel(tmp, base + PCIE_MISC_RC_BAR1_CONFIG_LO);
> +
> +	/* disable the PCIe->SCB memory window (RC_BAR3) */
> +	tmp = readl(base + PCIE_MISC_RC_BAR3_CONFIG_LO);
> +	tmp &= ~PCIE_MISC_RC_BAR3_CONFIG_LO_SIZE_MASK;
> +	writel(tmp, base + PCIE_MISC_RC_BAR3_CONFIG_LO);
> +
> +	/* Mask all interrupts since we are not handling any yet */
> +	writel(0xffffffff, pcie->base + PCIE_MSI_INTR2_MASK_SET);
> +
> +	/* clear any interrupts we find on boot */
> +	writel(0xffffffff, pcie->base + PCIE_MSI_INTR2_CLR);
> +
> +	if (pcie->gen)
> +		brcm_pcie_set_gen(pcie, pcie->gen);
> +
> +	/* Unassert the fundamental reset */
> +	brcm_pcie_perst_set(pcie, 0);
> +
> +	/*
> +	 * Give the RC/EP time to wake up, before trying to configure RC.
> +	 * Intermittently check status for link-up, up to a total of 100ms.
> +	 */
> +	for (i = 0; i < 100 && !brcm_pcie_link_up(pcie); i += 5)
> +		msleep(5);
> +
> +	if (!brcm_pcie_link_up(pcie)) {
> +		dev_err(dev, "link down\n");
> +		return -ENODEV;
> +	}
> +
> +	if (!brcm_pcie_rc_mode(pcie)) {
> +		dev_err(dev, "PCIe misconfigured; is in EP mode\n");
> +		return -EINVAL;
> +	}
> +
> +	resource_list_for_each_entry(entry, &bridge->windows) {
> +		res = entry->res;
> +
> +		if (resource_type(res) != IORESOURCE_MEM)
> +			continue;
> +
> +		if (num_out_wins >= BRCM_NUM_PCIE_OUT_WINS) {
> +			dev_err(pcie->dev, "too many outbound wins\n");
> +			return -EINVAL;
> +		}
> +
> +		brcm_pcie_set_outbound_win(pcie, num_out_wins, res->start,
> +					   res->start - entry->offset,
> +					   res->end - res->start + 1);
> +		num_out_wins++;
> +	}
> +
> +	/*
> +	 * For config space accesses on the RC, show the right class for
> +	 * a PCIe-PCIe bridge (the default setting is to be EP mode).
> +	 */
> +	tmp = readl(base + PCIE_RC_CFG_PRIV1_ID_VAL3);
> +	u32p_replace_bits(&tmp, 0x060400,
> +			  PCIE_RC_CFG_PRIV1_ID_VAL3_CLASS_CODE_MASK);
> +	writel(tmp, base + PCIE_RC_CFG_PRIV1_ID_VAL3);
> +
> +	if (pcie->ssc) {
> +		ret = brcm_pcie_set_ssc(pcie);
> +		if (ret == 0)
> +			ssc_good = true;
> +		else
> +			dev_err(dev, "failed attempt to enter ssc mode\n");
> +	}
> +
> +	lnksta = readw(base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKSTA);
> +	cls = FIELD_GET(PCI_EXP_LNKSTA_CLS, lnksta);
> +	nlw = FIELD_GET(PCI_EXP_LNKSTA_NLW, lnksta);
> +	dev_info(dev, "link up, %s x%u %s\n",
> +		 PCIE_SPEED2STR(cls + PCI_SPEED_133MHz_PCIX_533),
> +		 nlw, ssc_good ? "(SSC)" : "(!SSC)");
> +
> +	/* PCIe->SCB endian mode for BAR */
> +	tmp = readl(base + PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1);
> +	u32p_replace_bits(&tmp, PCIE_RC_CFG_VENDOR_SPCIFIC_REG1_LITTLE_ENDIAN,
> +		PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1_ENDIAN_MODE_BAR2_MASK);
> +	writel(tmp, base + PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1);
> +
> +	/*
> +	 * Refclk from RC should be gated with CLKREQ# input when ASPM L0s,L1
> +	 * is enabled => setting the CLKREQ_DEBUG_ENABLE field to 1.
> +	 */
> +	tmp = readl(base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
> +	tmp |= PCIE_MISC_HARD_PCIE_HARD_DEBUG_CLKREQ_DEBUG_ENABLE_MASK;
> +	writel(tmp, base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
> +
> +	return 0;
> +}
> +
> +/* L23 is a low-power PCIe link state */
> +static void brcm_pcie_enter_l23(struct brcm_pcie *pcie)
> +{
> +	void __iomem *base = pcie->base;
> +	int l23, i;
> +	u32 tmp;
> +
> +	/* Assert request for L23 */
> +	tmp = readl(base + PCIE_MISC_PCIE_CTRL);
> +	u32p_replace_bits(&tmp, 1, PCIE_MISC_PCIE_CTRL_PCIE_L23_REQUEST_MASK);
> +	writel(tmp, base + PCIE_MISC_PCIE_CTRL);
> +
> +	/* Wait up to 36 msec for L23 */
> +	tmp = readl(base + PCIE_MISC_PCIE_STATUS);
> +	l23 = FIELD_GET(PCIE_MISC_PCIE_STATUS_PCIE_LINK_IN_L23_MASK, tmp);
> +	for (i = 0; i < 15 && !l23; i++) {
> +		usleep_range(2000, 2400);
> +		tmp = readl(base + PCIE_MISC_PCIE_STATUS);
> +		l23 = FIELD_GET(PCIE_MISC_PCIE_STATUS_PCIE_LINK_IN_L23_MASK,
> +				tmp);
> +	}
> +
> +	if (!l23)
> +		dev_err(pcie->dev, "failed to enter low-power link state\n");
> +}
> +
> +static void brcm_pcie_turn_off(struct brcm_pcie *pcie)
> +{
> +	void __iomem *base = pcie->base;
> +	int tmp;
> +
> +	if (brcm_pcie_link_up(pcie))
> +		brcm_pcie_enter_l23(pcie);
> +	/* Assert fundamental reset */
> +	brcm_pcie_perst_set(pcie, 1);
> +
> +	/* Deassert request for L23 in case it was asserted */
> +	tmp = readl(base + PCIE_MISC_PCIE_CTRL);
> +	u32p_replace_bits(&tmp, 0, PCIE_MISC_PCIE_CTRL_PCIE_L23_REQUEST_MASK);
> +	writel(tmp, base + PCIE_MISC_PCIE_CTRL);
> +
> +	/* Turn off SerDes */
> +	tmp = readl(base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
> +	u32p_replace_bits(&tmp, 1, PCIE_MISC_HARD_PCIE_HARD_DEBUG_SERDES_IDDQ_MASK);
> +	writel(tmp, base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
> +
> +	/* Shutdown PCIe bridge */
> +	brcm_pcie_bridge_sw_init_set(pcie, 1);
> +}
> +
> +static void __brcm_pcie_remove(struct brcm_pcie *pcie)
> +{
> +	brcm_pcie_turn_off(pcie);
> +	clk_disable_unprepare(pcie->clk);
> +	clk_put(pcie->clk);
> +}
> +
> +static int brcm_pcie_remove(struct platform_device *pdev)
> +{
> +	struct brcm_pcie *pcie = platform_get_drvdata(pdev);
> +
> +	pci_stop_root_bus(pcie->root_bus);
> +	pci_remove_root_bus(pcie->root_bus);
> +	__brcm_pcie_remove(pcie);
> +
> +	return 0;
> +}
> +
> +static int brcm_pcie_probe(struct platform_device *pdev)
> +{
> +	struct device_node *np = pdev->dev.of_node;
> +	struct pci_host_bridge *bridge;
> +	struct brcm_pcie *pcie;
> +	struct pci_bus *child;
> +	struct resource *res;
> +	int ret;
> +
> +	bridge = devm_pci_alloc_host_bridge(&pdev->dev, sizeof(*pcie));
> +	if (!bridge)
> +		return -ENOMEM;
> +
> +	pcie = pci_host_bridge_priv(bridge);
> +	pcie->dev = &pdev->dev;
> +	pcie->np = np;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	pcie->base = devm_ioremap_resource(&pdev->dev, res);
> +	if (IS_ERR(pcie->base))
> +		return PTR_ERR(pcie->base);
> +
> +	pcie->clk = devm_clk_get_optional(&pdev->dev, "sw_pcie");
> +	if (IS_ERR(pcie->clk))
> +		return PTR_ERR(pcie->clk);
> +
> +	ret = of_pci_get_max_link_speed(np);
> +	pcie->gen = (ret < 0) ? 0 : ret;
> +
> +	pcie->ssc = of_property_read_bool(np, "brcm,enable-ssc");
> +
> +	ret = pci_parse_request_of_pci_ranges(pcie->dev, &bridge->windows,
> +					      &bridge->dma_ranges, NULL);
> +	if (ret)
> +		return ret;
> +
> +	ret = clk_prepare_enable(pcie->clk);
> +	if (ret) {
> +		dev_err(&pdev->dev, "could not enable clock\n");
> +		return ret;
> +	}
> +
> +	ret = brcm_pcie_setup(pcie);
> +	if (ret)
> +		goto fail;
> +
> +	bridge->dev.parent = &pdev->dev;
> +	bridge->busnr = 0;
> +	bridge->ops = &brcm_pcie_ops;
> +	bridge->sysdata = pcie;
> +	bridge->map_irq = of_irq_parse_and_map_pci;
> +	bridge->swizzle_irq = pci_common_swizzle;
> +
> +	ret = pci_scan_root_bus_bridge(bridge);
> +	if (ret < 0) {
> +		dev_err(pcie->dev, "Scanning root bridge failed\n");
> +		goto fail;
> +	}
> +
> +	pci_assign_unassigned_bus_resources(bridge->bus);
> +	list_for_each_entry(child, &bridge->bus->children, node)
> +		pcie_bus_configure_settings(child);
> +	pci_bus_add_devices(bridge->bus);
> +	platform_set_drvdata(pdev, pcie);
> +	pcie->root_bus = bridge->bus;
> +
> +	return 0;
> +fail:
> +	__brcm_pcie_remove(pcie);
> +	return ret;
> +}
> +
> +static const struct of_device_id brcm_pcie_match[] = {
> +	{ .compatible = "brcm,bcm2711-pcie" },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, brcm_pcie_match);
> +
> +static struct platform_driver brcm_pcie_driver = {
> +	.probe = brcm_pcie_probe,
> +	.remove = brcm_pcie_remove,
> +	.driver = {
> +		.name = "brcm-pcie",
> +		.of_match_table = brcm_pcie_match,
> +	},
> +};
> +module_platform_driver(brcm_pcie_driver);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("Broadcom STB PCIe RC driver");
> +MODULE_AUTHOR("Broadcom");
> -- 
> 2.24.0
> 

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Re: [PATCH v3 4/7] PCI: brcmstb: add Broadcom STB PCIe host controller driver

[Jim Quinlan]

On Mon, Dec 2, 2019 at 10:01 AM Andrew Murray <andrew.murray@arm.com> wrote:
>
> On Tue, Nov 26, 2019 at 10:19:42AM +0100, Nicolas Saenz Julienne wrote:
> > From: Jim Quinlan <james.quinlan@broadcom.com>
>
> Nit: Capitalise the 'a' in 'add Broadcom STB...' in the subject.
>
>
> >
> > This adds a basic driver for Broadcom's STB PCIe controller, for now
> > aimed at Raspberry Pi 4's SoC, bcm2711.
> >
> > Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>
> > Co-developed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> > Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> >
> > ---
> >
> > Changes since v2:
> >   - Correct rc_bar2_offset sign
> >   - Invert IRQ clear and masking in setup code
> >   - Use bitfield.h, redo all register ops while keeping the register
> >     names intact
> >   - Remove all SHIFT register definitions
> >   - Get rid of all _RB writes
> >   - Get rid of of_data
> >   - Don't iterate over inexisting dma-ranges
> >   - Add comment regarding dma-ranges validation
> >   - Small cosmetic cleanups
> >   - Fix license mismatch
> >   - Set driver Kconfig tristate
> >   - Didn't add any comment about the controller not being I/O coherent
> >     for now as I wait for Jeremy's reply
> >
> > Changes since v1:
> >   - Fix Kconfig
> >   - Remove pci domain check
> >   - Remove all MSI related code
> >   - Remove supend/resume code
> >   - Simplify link state wait routine
> >   - Prefix all functions
> >   - Use of_device_get_match_data()
> >   - Use devm_clk_get_optional()
> >   - Get rid of irq variable
> >   - Use STB all over the driver
> >   - Simplify map_bus() function
> >   - Fix license mismatch
> >   - Remove unused register definitions
> >   - Small cleanups, spell errors
> >
> > This is based on Jim's original submission[1] but adapted and tailored
> > specifically to bcm2711's needs (that's the Raspberry Pi 4). Support for
> > the rest of the brcmstb family will soon follow once we get support for
> > multiple dma-ranges in dma/direct.
> >
> > [1] https://patchwork.kernel.org/patch/10605959/
> >
> >  drivers/pci/controller/Kconfig        |   8 +
> >  drivers/pci/controller/Makefile       |   1 +
> >  drivers/pci/controller/pcie-brcmstb.c | 753 ++++++++++++++++++++++++++
> >  3 files changed, 762 insertions(+)
> >  create mode 100644 drivers/pci/controller/pcie-brcmstb.c
> >
> > diff --git a/drivers/pci/controller/Kconfig b/drivers/pci/controller/Kconfig
> > index c77069c8ee5d..27504f108ee5 100644
> > --- a/drivers/pci/controller/Kconfig
> > +++ b/drivers/pci/controller/Kconfig
> > @@ -253,6 +253,14 @@ config VMD
> >         To compile this driver as a module, choose M here: the
> >         module will be called vmd.
> >
> > +config PCIE_BRCMSTB
> > +     tristate "Broadcom Brcmstb PCIe host controller"
> > +     depends on ARCH_BCM2835 || COMPILE_TEST
> > +     depends on OF
> > +     help
> > +       Say Y here to enable PCIe host controller support for
> > +       Broadcom STB based SoCs, like the Raspberry Pi 4.
> > +
> >  config PCI_HYPERV_INTERFACE
> >       tristate "Hyper-V PCI Interface"
> >       depends on X86 && HYPERV && PCI_MSI && PCI_MSI_IRQ_DOMAIN && X86_64
> > diff --git a/drivers/pci/controller/Makefile b/drivers/pci/controller/Makefile
> > index 3d4f597f15ce..01b2502a5323 100644
> > --- a/drivers/pci/controller/Makefile
> > +++ b/drivers/pci/controller/Makefile
> > @@ -28,6 +28,7 @@ obj-$(CONFIG_PCIE_MEDIATEK) += pcie-mediatek.o
> >  obj-$(CONFIG_PCIE_MOBIVEIL) += pcie-mobiveil.o
> >  obj-$(CONFIG_PCIE_TANGO_SMP8759) += pcie-tango.o
> >  obj-$(CONFIG_VMD) += vmd.o
> > +obj-$(CONFIG_PCIE_BRCMSTB) += pcie-brcmstb.o
> >  # pcie-hisi.o quirks are needed even without CONFIG_PCIE_DW
> >  obj-y                                += dwc/
> >
> > diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
> > new file mode 100644
> > index 000000000000..28c1b9429d3d
> > --- /dev/null
> > +++ b/drivers/pci/controller/pcie-brcmstb.c
> > @@ -0,0 +1,753 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/* Copyright (C) 2009 - 2019 Broadcom */
> > +
> > +#include <linux/bitfield.h>
> > +#include <linux/clk.h>
> > +#include <linux/compiler.h>
> > +#include <linux/delay.h>
> > +#include <linux/init.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/io.h>
> > +#include <linux/ioport.h>
> > +#include <linux/irqdomain.h>
> > +#include <linux/kernel.h>
> > +#include <linux/list.h>
> > +#include <linux/log2.h>
> > +#include <linux/module.h>
> > +#include <linux/of_address.h>
> > +#include <linux/of_irq.h>
> > +#include <linux/of_pci.h>
> > +#include <linux/of_platform.h>
> > +#include <linux/pci.h>
> > +#include <linux/printk.h>
> > +#include <linux/sizes.h>
> > +#include <linux/slab.h>
> > +#include <linux/string.h>
> > +#include <linux/types.h>
> > +
> > +#include "../pci.h"
> > +
> > +/* BRCM_PCIE_CAP_REGS - Offset for the mandatory capability config regs */
>
> NIT: You can probably rephrase this from "BRCM_PCIE_CAP_REGS - Offset for ..." to "Offset for ..."
>
>
> > +#define BRCM_PCIE_CAP_REGS                           0x00ac
> > +
> > +/*
> > + * Broadcom STB PCIe Register Offsets. The names are from the chip's RDB and we
> > + * use them here so that a script can correlate this code and the RDB to
> > + * prevent discrepancies.
>
> What is RDB? Is the script public? Do other Broadcom drivers in the kernel take
> this approach (if not then why do something different here?).
>
> Unless anyone with the kernel source can benefit from any of this then it's
> likely to not provide any value - and instead just result in the naming of the
> registers not consistent with the rest of the kernel.
Hello,

RDB == Register DataBase.  It's a byproduct of the chip design and
supported by various tools within Broadcom.  RDB descriptions and
tools are not in the public domain.

 For the standard PCIe config registers, I agree with you, we should
use the Linux constants.  And we could also probably remove the
leading 'PCIE_'.  But if we rename other registers it  will be hard
for Broadcom engineers to figure out what register is  actually
involved w/o looking up the offset and identifying the appropriate RDB
register.

Other Broadcom-authored drivers do not really have this problem; they
have shorter RDB names and have possibly shortened them further.  But
unfortunately the PCIe HW has obnoxiously long registers names and  it
is tough to  shorten them to something that still looks like the
original.

Regards,
JimQ

>
> In any case I don't have a problem with the register names, so I'd suggest you
> just drop the comment.
>
> With those you can add:
>
> Reviewed-by: Andrew Murray <andrew.murray@arm.com>
>
> > + */
> > +#define PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1                              0x0188
> > +#define  PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1_ENDIAN_MODE_BAR2_MASK       0xc
> > +#define  PCIE_RC_CFG_VENDOR_SPCIFIC_REG1_LITTLE_ENDIAN                       0x0
> > +
> > +#define PCIE_RC_CFG_PRIV1_ID_VAL3                    0x043c
> > +#define  PCIE_RC_CFG_PRIV1_ID_VAL3_CLASS_CODE_MASK   0xffffff
> > +
> > +#define PCIE_RC_DL_MDIO_ADDR                         0x1100
> > +#define PCIE_RC_DL_MDIO_WR_DATA                              0x1104
> > +#define PCIE_RC_DL_MDIO_RD_DATA                              0x1108
> > +
> > +#define PCIE_MISC_MISC_CTRL                          0x4008
> > +#define  PCIE_MISC_MISC_CTRL_SCB_ACCESS_EN_MASK              0x1000
> > +#define  PCIE_MISC_MISC_CTRL_CFG_READ_UR_MODE_MASK   0x2000
> > +#define  PCIE_MISC_MISC_CTRL_MAX_BURST_SIZE_MASK     0x300000
> > +#define  PCIE_MISC_MISC_CTRL_MAX_BURST_SIZE_128              0x0
> > +#define  PCIE_MISC_MISC_CTRL_SCB0_SIZE_MASK          0xf8000000
> > +
> > +#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LO             0x400c
> > +#define PCIE_MEM_WIN0_LO(win)        \
> > +             PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LO + ((win) * 4)
> > +
> > +#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_HI             0x4010
> > +#define PCIE_MEM_WIN0_HI(win)        \
> > +             PCIE_MISC_CPU_2_PCIE_MEM_WIN0_HI + ((win) * 4)
> > +
> > +#define PCIE_MISC_RC_BAR1_CONFIG_LO                  0x402c
> > +#define  PCIE_MISC_RC_BAR1_CONFIG_LO_SIZE_MASK               0x1f
> > +
> > +#define PCIE_MISC_RC_BAR2_CONFIG_LO                  0x4034
> > +#define  PCIE_MISC_RC_BAR2_CONFIG_LO_SIZE_MASK               0x1f
> > +#define PCIE_MISC_RC_BAR2_CONFIG_HI                  0x4038
> > +
> > +#define PCIE_MISC_RC_BAR3_CONFIG_LO                  0x403c
> > +#define  PCIE_MISC_RC_BAR3_CONFIG_LO_SIZE_MASK               0x1f
> > +
> > +#define PCIE_MISC_PCIE_CTRL                          0x4064
> > +#define  PCIE_MISC_PCIE_CTRL_PCIE_L23_REQUEST_MASK   0x1
> > +
> > +#define PCIE_MISC_PCIE_STATUS                                0x4068
> > +#define  PCIE_MISC_PCIE_STATUS_PCIE_PORT_MASK                0x80
> > +#define  PCIE_MISC_PCIE_STATUS_PCIE_DL_ACTIVE_MASK   0x20
> > +#define  PCIE_MISC_PCIE_STATUS_PCIE_PHYLINKUP_MASK   0x10
> > +#define  PCIE_MISC_PCIE_STATUS_PCIE_LINK_IN_L23_MASK 0x40
> > +
> > +#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT             0x4070
> > +#define  PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_LIMIT_MASK 0xfff00000
> > +#define  PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_BASE_MASK  0xfff0
> > +#define PCIE_MEM_WIN0_BASE_LIMIT(win)        \
> > +             PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT + ((win) * 4)
> > +
> > +#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_HI                        0x4080
> > +#define  PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_HI_BASE_MASK     0xff
> > +#define PCIE_MEM_WIN0_BASE_HI(win)   \
> > +             PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_HI + ((win) * 8)
> > +
> > +#define PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LIMIT_HI                       0x4084
> > +#define  PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LIMIT_HI_LIMIT_MASK   0xff
> > +#define PCIE_MEM_WIN0_LIMIT_HI(win)  \
> > +             PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LIMIT_HI + ((win) * 8)
> > +
> > +#define PCIE_MISC_HARD_PCIE_HARD_DEBUG                                       0x4204
> > +#define  PCIE_MISC_HARD_PCIE_HARD_DEBUG_CLKREQ_DEBUG_ENABLE_MASK     0x2
> > +#define  PCIE_MISC_HARD_PCIE_HARD_DEBUG_SERDES_IDDQ_MASK             0x08000000
> > +
> > +#define PCIE_MSI_INTR2_STATUS                                0x4500
> > +#define PCIE_MSI_INTR2_CLR                           0x4508
> > +#define PCIE_MSI_INTR2_MASK_SET                              0x4510
> > +#define PCIE_MSI_INTR2_MASK_CLR                              0x4514
> > +
> > +#define PCIE_EXT_CFG_DATA                            0x8000
> > +
> > +#define PCIE_EXT_CFG_INDEX                           0x9000
> > +#define  PCIE_EXT_BUSNUM_SHIFT                               20
> > +#define  PCIE_EXT_SLOT_SHIFT                         15
> > +#define  PCIE_EXT_FUNC_SHIFT                         12
> > +
> > +#define PCIE_RGR1_SW_INIT_1                          0x9210
> > +#define  PCIE_RGR1_SW_INIT_1_PERST_MASK                      0x1
> > +#define  PCIE_RGR1_SW_INIT_1_INIT_MASK                       0x2
> > +
> > +/* PCIe parameters */
> > +#define BRCM_NUM_PCIE_OUT_WINS               0x4
> > +
> > +/* MDIO registers */
> > +#define MDIO_PORT0                   0x0
> > +#define MDIO_DATA_MASK                       0x7fffffff
> > +#define MDIO_PORT_MASK                       0xf0000
> > +#define MDIO_REGAD_MASK                      0xffff
> > +#define MDIO_CMD_MASK                        0xfff00000
> > +#define MDIO_CMD_READ                        0x1
> > +#define MDIO_CMD_WRITE                       0x0
> > +#define MDIO_DATA_DONE_MASK          0x80000000
> > +#define MDIO_RD_DONE(x)                      (((x) & MDIO_DATA_DONE_MASK) ? 1 : 0)
> > +#define MDIO_WT_DONE(x)                      (((x) & MDIO_DATA_DONE_MASK) ? 0 : 1)
> > +#define SSC_REGS_ADDR                        0x1100
> > +#define SET_ADDR_OFFSET                      0x1f
> > +#define SSC_CNTL_OFFSET                      0x2
> > +#define SSC_CNTL_OVRD_EN_MASK                0x8000
> > +#define SSC_CNTL_OVRD_VAL_MASK               0x4000
> > +#define SSC_STATUS_OFFSET            0x1
> > +#define SSC_STATUS_SSC_MASK          0x400
> > +#define SSC_STATUS_PLL_LOCK_MASK     0x800
> > +
> > +/* Internal PCIe Host Controller Information.*/
> > +struct brcm_pcie {
> > +     struct device           *dev;
> > +     void __iomem            *base;
> > +     struct clk              *clk;
> > +     struct pci_bus          *root_bus;
> > +     struct device_node      *np;
> > +     bool                    ssc;
> > +     int                     gen;
> > +};
> > +
> > +/*
> > + * This is to convert the size of the inbound "BAR" region to the
> > + * non-linear values of PCIE_X_MISC_RC_BAR[123]_CONFIG_LO.SIZE
> > + */
> > +static int brcm_pcie_encode_ibar_size(u64 size)
> > +{
> > +     int log2_in = ilog2(size);
> > +
> > +     if (log2_in >= 12 && log2_in <= 15)
> > +             /* Covers 4KB to 32KB (inclusive) */
> > +             return (log2_in - 12) + 0x1c;
> > +     else if (log2_in >= 16 && log2_in <= 35)
> > +             /* Covers 64KB to 32GB, (inclusive) */
> > +             return log2_in - 15;
> > +     /* Something is awry so disable */
> > +     return 0;
> > +}
> > +
> > +static u32 brcm_pcie_mdio_form_pkt(int port, int regad, int cmd)
> > +{
> > +     u32 pkt = 0;
> > +
> > +     pkt |= FIELD_PREP(MDIO_PORT_MASK, port);
> > +     pkt |= FIELD_PREP(MDIO_REGAD_MASK, regad);
> > +     pkt |= FIELD_PREP(MDIO_CMD_MASK, cmd);
> > +
> > +     return pkt;
> > +}
> > +
> > +/* negative return value indicates error */
> > +static int brcm_pcie_mdio_read(void __iomem *base, u8 port, u8 regad, u32 *val)
> > +{
> > +     int tries;
> > +     u32 data;
> > +
> > +     writel(brcm_pcie_mdio_form_pkt(port, regad, MDIO_CMD_READ),
> > +                base + PCIE_RC_DL_MDIO_ADDR);
> > +     readl(base + PCIE_RC_DL_MDIO_ADDR);
> > +
> > +     data = readl(base + PCIE_RC_DL_MDIO_RD_DATA);
> > +     for (tries = 0; !MDIO_RD_DONE(data) && tries < 10; tries++) {
> > +             udelay(10);
> > +             data = readl(base + PCIE_RC_DL_MDIO_RD_DATA);
> > +     }
> > +
> > +     *val = FIELD_GET(MDIO_DATA_MASK, data);
> > +     return MDIO_RD_DONE(data) ? 0 : -EIO;
> > +}
> > +
> > +/* negative return value indicates error */
> > +static int brcm_pcie_mdio_write(void __iomem *base, u8 port,
> > +                             u8 regad, u16 wrdata)
> > +{
> > +     int tries;
> > +     u32 data;
> > +
> > +     writel(brcm_pcie_mdio_form_pkt(port, regad, MDIO_CMD_WRITE),
> > +                base + PCIE_RC_DL_MDIO_ADDR);
> > +     readl(base + PCIE_RC_DL_MDIO_ADDR);
> > +     writel(MDIO_DATA_DONE_MASK | wrdata, base + PCIE_RC_DL_MDIO_WR_DATA);
> > +
> > +     data = readl(base + PCIE_RC_DL_MDIO_WR_DATA);
> > +     for (tries = 0; !MDIO_WT_DONE(data) && tries < 10; tries++) {
> > +             udelay(10);
> > +             data = readl(base + PCIE_RC_DL_MDIO_WR_DATA);
> > +     }
> > +
> > +     return MDIO_WT_DONE(data) ? 0 : -EIO;
> > +}
> > +
> > +/*
> > + * Configures device for Spread Spectrum Clocking (SSC) mode; a negative
> > + * return value indicates error.
> > + */
> > +static int brcm_pcie_set_ssc(struct brcm_pcie *pcie)
> > +{
> > +     int pll, ssc;
> > +     int ret;
> > +     u32 tmp;
> > +
> > +     ret = brcm_pcie_mdio_write(pcie->base, MDIO_PORT0, SET_ADDR_OFFSET,
> > +                                SSC_REGS_ADDR);
> > +     if (ret < 0)
> > +             return ret;
> > +
> > +     ret = brcm_pcie_mdio_read(pcie->base, MDIO_PORT0,
> > +                               SSC_CNTL_OFFSET, &tmp);
> > +     if (ret < 0)
> > +             return ret;
> > +
> > +     u32p_replace_bits(&tmp, 1, SSC_CNTL_OVRD_EN_MASK);
> > +     u32p_replace_bits(&tmp, 1, SSC_CNTL_OVRD_VAL_MASK);
> > +     ret = brcm_pcie_mdio_write(pcie->base, MDIO_PORT0,
> > +                                SSC_CNTL_OFFSET, tmp);
> > +     if (ret < 0)
> > +             return ret;
> > +
> > +     usleep_range(1000, 2000);
> > +     ret = brcm_pcie_mdio_read(pcie->base, MDIO_PORT0,
> > +                               SSC_STATUS_OFFSET, &tmp);
> > +     if (ret < 0)
> > +             return ret;
> > +
> > +     ssc = FIELD_GET(SSC_STATUS_SSC_MASK, tmp);
> > +     pll = FIELD_GET(SSC_STATUS_PLL_LOCK_MASK, tmp);
> > +
> > +     return ssc && pll ? 0 : -EIO;
> > +}
> > +
> > +/* Limits operation to a specific generation (1, 2, or 3) */
> > +static void brcm_pcie_set_gen(struct brcm_pcie *pcie, int gen)
> > +{
> > +     u16 lnkctl2 = readw(pcie->base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKCTL2);
> > +     u32 lnkcap = readl(pcie->base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKCAP);
> > +
> > +     lnkcap = (lnkcap & ~PCI_EXP_LNKCAP_SLS) | gen;
> > +     writel(lnkcap, pcie->base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKCAP);
> > +
> > +     lnkctl2 = (lnkctl2 & ~0xf) | gen;
> > +     writew(lnkctl2, pcie->base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKCTL2);
> > +}
> > +
> > +static void brcm_pcie_set_outbound_win(struct brcm_pcie *pcie,
> > +                                    unsigned int win, u64 cpu_addr,
> > +                                    u64 pcie_addr, u64 size)
> > +{
> > +     u32 cpu_addr_mb_high, limit_addr_mb_high;
> > +     phys_addr_t cpu_addr_mb, limit_addr_mb;
> > +     int high_addr_shift;
> > +     u32 tmp;
> > +
> > +     /* Set the base of the pcie_addr window */
> > +     writel(lower_32_bits(pcie_addr), pcie->base + PCIE_MEM_WIN0_LO(win));
> > +     writel(upper_32_bits(pcie_addr), pcie->base + PCIE_MEM_WIN0_HI(win));
> > +
> > +     /* Write the addr base & limit lower bits (in MBs) */
> > +     cpu_addr_mb = cpu_addr / SZ_1M;
> > +     limit_addr_mb = (cpu_addr + size - 1) / SZ_1M;
> > +
> > +     tmp = readl(pcie->base + PCIE_MEM_WIN0_BASE_LIMIT(win));
> > +     u32p_replace_bits(&tmp, cpu_addr_mb,
> > +                       PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_BASE_MASK);
> > +     u32p_replace_bits(&tmp, limit_addr_mb,
> > +                       PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_LIMIT_MASK);
> > +     writel(tmp, pcie->base + PCIE_MEM_WIN0_BASE_LIMIT(win));
> > +
> > +     /* Write the cpu & limit addr upper bits */
> > +     high_addr_shift =
> > +             HWEIGHT32(PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_LIMIT_BASE_MASK);
> > +
> > +     cpu_addr_mb_high = cpu_addr_mb >> high_addr_shift;
> > +     tmp = readl(pcie->base + PCIE_MEM_WIN0_BASE_HI(win));
> > +     u32p_replace_bits(&tmp, cpu_addr_mb_high,
> > +                       PCIE_MISC_CPU_2_PCIE_MEM_WIN0_BASE_HI_BASE_MASK);
> > +     writel(tmp, pcie->base + PCIE_MEM_WIN0_BASE_HI(win));
> > +
> > +     limit_addr_mb_high = limit_addr_mb >> high_addr_shift;
> > +     tmp = readl(pcie->base + PCIE_MEM_WIN0_LIMIT_HI(win));
> > +     u32p_replace_bits(&tmp, limit_addr_mb_high,
> > +                       PCIE_MISC_CPU_2_PCIE_MEM_WIN0_LIMIT_HI_LIMIT_MASK);
> > +     writel(tmp, pcie->base + PCIE_MEM_WIN0_LIMIT_HI(win));
> > +}
> > +
> > +/* The controller is capable of serving in both RC and EP roles */
> > +static bool brcm_pcie_rc_mode(struct brcm_pcie *pcie)
> > +{
> > +     void __iomem *base = pcie->base;
> > +     u32 val = readl(base + PCIE_MISC_PCIE_STATUS);
> > +
> > +     return !!FIELD_GET(PCIE_MISC_PCIE_STATUS_PCIE_PORT_MASK, val);
> > +}
> > +
> > +static bool brcm_pcie_link_up(struct brcm_pcie *pcie)
> > +{
> > +     u32 val = readl(pcie->base + PCIE_MISC_PCIE_STATUS);
> > +     u32 dla = FIELD_GET(PCIE_MISC_PCIE_STATUS_PCIE_DL_ACTIVE_MASK, val);
> > +     u32 plu = FIELD_GET(PCIE_MISC_PCIE_STATUS_PCIE_PHYLINKUP_MASK, val);
> > +
> > +     return dla && plu;
> > +}
> > +
> > +/* Configuration space read/write support */
> > +static inline int brcm_pcie_cfg_index(int busnr, int devfn, int reg)
> > +{
> > +     return ((PCI_SLOT(devfn) & 0x1f) << PCIE_EXT_SLOT_SHIFT)
> > +             | ((PCI_FUNC(devfn) & 0x07) << PCIE_EXT_FUNC_SHIFT)
> > +             | (busnr << PCIE_EXT_BUSNUM_SHIFT)
> > +             | (reg & ~3);
> > +}
> > +
> > +static void __iomem *brcm_pcie_map_conf(struct pci_bus *bus, unsigned int devfn,
> > +                                     int where)
> > +{
> > +     struct brcm_pcie *pcie = bus->sysdata;
> > +     void __iomem *base = pcie->base;
> > +     int idx;
> > +
> > +     /* Accesses to the RC go right to the RC registers if slot==0 */
> > +     if (pci_is_root_bus(bus))
> > +             return PCI_SLOT(devfn) ? NULL : base + where;
> > +
> > +     /* For devices, write to the config space index register */
> > +     idx = brcm_pcie_cfg_index(bus->number, devfn, 0);
> > +     writel(idx, pcie->base + PCIE_EXT_CFG_INDEX);
> > +     return base + PCIE_EXT_CFG_DATA + where;
> > +}
> > +
> > +static struct pci_ops brcm_pcie_ops = {
> > +     .map_bus = brcm_pcie_map_conf,
> > +     .read = pci_generic_config_read,
> > +     .write = pci_generic_config_write,
> > +};
> > +
> > +static inline void brcm_pcie_bridge_sw_init_set(struct brcm_pcie *pcie, u32 val)
> > +{
> > +     u32 tmp;
> > +
> > +     tmp = readl(pcie->base + PCIE_RGR1_SW_INIT_1);
> > +     u32p_replace_bits(&tmp, val, PCIE_RGR1_SW_INIT_1_INIT_MASK);
> > +     writel(tmp, pcie->base + PCIE_RGR1_SW_INIT_1);
> > +}
> > +
> > +static inline void brcm_pcie_perst_set(struct brcm_pcie *pcie, u32 val)
> > +{
> > +     u32 tmp;
> > +
> > +     tmp = readl(pcie->base + PCIE_RGR1_SW_INIT_1);
> > +     u32p_replace_bits(&tmp, val, PCIE_RGR1_SW_INIT_1_PERST_MASK);
> > +     writel(tmp, pcie->base + PCIE_RGR1_SW_INIT_1);
> > +}
> > +
> > +static inline int brcm_pcie_get_rc_bar2_size_and_offset(struct brcm_pcie *pcie,
> > +                                                     u64 *rc_bar2_size,
> > +                                                     u64 *rc_bar2_offset)
> > +{
> > +     struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
> > +     struct device *dev = pcie->dev;
> > +     struct resource_entry *entry;
> > +
> > +     entry = resource_list_first_type(&bridge->dma_ranges, IORESOURCE_MEM);
> > +     if (!entry)
> > +             return -ENODEV;
> > +
> > +     *rc_bar2_offset = -entry->offset;
> > +     *rc_bar2_size = roundup_pow_of_two_u64(entry->res->end -
> > +                                            entry->res->start + 1);
> > +
> > +     /*
> > +      * We validate the inbound memory view even though we should trust
> > +      * whatever the device-tree provides. This is because of an HW issue on
> > +      * early Raspberry Pi 4's revisions (bcm2711). It turns out its
> > +      * firmware has to dynamically edit dma-ranges due to a bug on the
> > +      * PCIe controller integration, which prohibits any access above the
> > +      * lower 3GB of memory. Given this, we decided to keep the dma-ranges
> > +      * in check, avoiding hard to debug device-tree related issues in the
> > +      * future:
> > +      *
> > +      * The PCIe host controller by design must set the inbound viewport to
> > +      * be a contiguous arrangement of all of the system's memory.  In
> > +      * addition, its size mut be a power of two.  To further complicate
> > +      * matters, the viewport must start on a pcie-address that is aligned
> > +      * on a multiple of its size.  If a portion of the viewport does not
> > +      * represent system memory -- e.g. 3GB of memory requires a 4GB
> > +      * viewport -- we can map the outbound memory in or after 3GB and even
> > +      * though the viewport will overlap the outbound memory the controller
> > +      * will know to send outbound memory downstream and everything else
> > +      * upstream.
> > +      *
> > +      * For example:
> > +      *
> > +      * - The best-case scenario, memory up to 3GB, is to place the inbound
> > +      *   region in the first 4GB of pcie-space, as some legacy devices can
> > +      *   only address 32bits. We would also like to put the MSI under 4GB
> > +      *   as well, since some devices require a 32bit MSI target address.
> > +      *
> > +      * - If the system memory is 4GB or larger we cannot start the inbound
> > +      *   region at location 0 (since we have to allow some space for
> > +      *   outbound memory @ 3GB). So instead it will  start at the 1x
> > +      *   multiple of its size
> > +      */
> > +     if (!*rc_bar2_size || *rc_bar2_offset % *rc_bar2_size ||
> > +         (*rc_bar2_offset < SZ_4G && *rc_bar2_offset > SZ_2G)) {
> > +             dev_err(dev, "Invalid rc_bar2_offset/size: size 0x%llx, off 0x%llx\n",
> > +                     *rc_bar2_size, *rc_bar2_offset);
> > +             return -EINVAL;
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +static int brcm_pcie_setup(struct brcm_pcie *pcie)
> > +{
> > +     struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
> > +     u64 rc_bar2_offset, rc_bar2_size;
> > +     void __iomem *base = pcie->base;
> > +     struct device *dev = pcie->dev;
> > +     struct resource_entry *entry;
> > +     unsigned int scb_size_val;
> > +     bool ssc_good = false;
> > +     struct resource *res;
> > +     int num_out_wins = 0;
> > +     u16 nlw, cls, lnksta;
> > +     int i, ret;
> > +     u32 tmp;
> > +
> > +     /* Reset the bridge */
> > +     brcm_pcie_bridge_sw_init_set(pcie, 1);
> > +
> > +     usleep_range(100, 200);
> > +
> > +     /* Take the bridge out of reset */
> > +     brcm_pcie_bridge_sw_init_set(pcie, 0);
> > +
> > +     tmp = readl(base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
> > +     tmp &= ~PCIE_MISC_HARD_PCIE_HARD_DEBUG_SERDES_IDDQ_MASK;
> > +     writel(tmp, base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
> > +     /* Wait for SerDes to be stable */
> > +     usleep_range(100, 200);
> > +
> > +     /* Set SCB_MAX_BURST_SIZE, CFG_READ_UR_MODE, SCB_ACCESS_EN */
> > +     u32p_replace_bits(&tmp, 1, PCIE_MISC_MISC_CTRL_SCB_ACCESS_EN_MASK);
> > +     u32p_replace_bits(&tmp, 1, PCIE_MISC_MISC_CTRL_CFG_READ_UR_MODE_MASK);
> > +     u32p_replace_bits(&tmp, PCIE_MISC_MISC_CTRL_MAX_BURST_SIZE_128,
> > +                       PCIE_MISC_MISC_CTRL_MAX_BURST_SIZE_MASK);
> > +     writel(tmp, base + PCIE_MISC_MISC_CTRL);
> > +
> > +     ret = brcm_pcie_get_rc_bar2_size_and_offset(pcie, &rc_bar2_size,
> > +                                                 &rc_bar2_offset);
> > +     if (ret)
> > +             return ret;
> > +
> > +     tmp = lower_32_bits(rc_bar2_offset);
> > +     u32p_replace_bits(&tmp, brcm_pcie_encode_ibar_size(rc_bar2_size),
> > +                       PCIE_MISC_RC_BAR2_CONFIG_LO_SIZE_MASK);
> > +     writel(tmp, base + PCIE_MISC_RC_BAR2_CONFIG_LO);
> > +     writel(upper_32_bits(rc_bar2_offset),
> > +            base + PCIE_MISC_RC_BAR2_CONFIG_HI);
> > +
> > +     scb_size_val = rc_bar2_size ?
> > +                    ilog2(rc_bar2_size) - 15 : 0xf; /* 0xf is 1GB */
> > +     tmp = readl(base + PCIE_MISC_MISC_CTRL);
> > +     u32p_replace_bits(&tmp, scb_size_val,
> > +                       PCIE_MISC_MISC_CTRL_SCB0_SIZE_MASK);
> > +     writel(tmp, base + PCIE_MISC_MISC_CTRL);
> > +
> > +     /* disable the PCIe->GISB memory window (RC_BAR1) */
> > +     tmp = readl(base + PCIE_MISC_RC_BAR1_CONFIG_LO);
> > +     tmp &= ~PCIE_MISC_RC_BAR1_CONFIG_LO_SIZE_MASK;
> > +     writel(tmp, base + PCIE_MISC_RC_BAR1_CONFIG_LO);
> > +
> > +     /* disable the PCIe->SCB memory window (RC_BAR3) */
> > +     tmp = readl(base + PCIE_MISC_RC_BAR3_CONFIG_LO);
> > +     tmp &= ~PCIE_MISC_RC_BAR3_CONFIG_LO_SIZE_MASK;
> > +     writel(tmp, base + PCIE_MISC_RC_BAR3_CONFIG_LO);
> > +
> > +     /* Mask all interrupts since we are not handling any yet */
> > +     writel(0xffffffff, pcie->base + PCIE_MSI_INTR2_MASK_SET);
> > +
> > +     /* clear any interrupts we find on boot */
> > +     writel(0xffffffff, pcie->base + PCIE_MSI_INTR2_CLR);
> > +
> > +     if (pcie->gen)
> > +             brcm_pcie_set_gen(pcie, pcie->gen);
> > +
> > +     /* Unassert the fundamental reset */
> > +     brcm_pcie_perst_set(pcie, 0);
> > +
> > +     /*
> > +      * Give the RC/EP time to wake up, before trying to configure RC.
> > +      * Intermittently check status for link-up, up to a total of 100ms.
> > +      */
> > +     for (i = 0; i < 100 && !brcm_pcie_link_up(pcie); i += 5)
> > +             msleep(5);
> > +
> > +     if (!brcm_pcie_link_up(pcie)) {
> > +             dev_err(dev, "link down\n");
> > +             return -ENODEV;
> > +     }
> > +
> > +     if (!brcm_pcie_rc_mode(pcie)) {
> > +             dev_err(dev, "PCIe misconfigured; is in EP mode\n");
> > +             return -EINVAL;
> > +     }
> > +
> > +     resource_list_for_each_entry(entry, &bridge->windows) {
> > +             res = entry->res;
> > +
> > +             if (resource_type(res) != IORESOURCE_MEM)
> > +                     continue;
> > +
> > +             if (num_out_wins >= BRCM_NUM_PCIE_OUT_WINS) {
> > +                     dev_err(pcie->dev, "too many outbound wins\n");
> > +                     return -EINVAL;
> > +             }
> > +
> > +             brcm_pcie_set_outbound_win(pcie, num_out_wins, res->start,
> > +                                        res->start - entry->offset,
> > +                                        res->end - res->start + 1);
> > +             num_out_wins++;
> > +     }
> > +
> > +     /*
> > +      * For config space accesses on the RC, show the right class for
> > +      * a PCIe-PCIe bridge (the default setting is to be EP mode).
> > +      */
> > +     tmp = readl(base + PCIE_RC_CFG_PRIV1_ID_VAL3);
> > +     u32p_replace_bits(&tmp, 0x060400,
> > +                       PCIE_RC_CFG_PRIV1_ID_VAL3_CLASS_CODE_MASK);
> > +     writel(tmp, base + PCIE_RC_CFG_PRIV1_ID_VAL3);
> > +
> > +     if (pcie->ssc) {
> > +             ret = brcm_pcie_set_ssc(pcie);
> > +             if (ret == 0)
> > +                     ssc_good = true;
> > +             else
> > +                     dev_err(dev, "failed attempt to enter ssc mode\n");
> > +     }
> > +
> > +     lnksta = readw(base + BRCM_PCIE_CAP_REGS + PCI_EXP_LNKSTA);
> > +     cls = FIELD_GET(PCI_EXP_LNKSTA_CLS, lnksta);
> > +     nlw = FIELD_GET(PCI_EXP_LNKSTA_NLW, lnksta);
> > +     dev_info(dev, "link up, %s x%u %s\n",
> > +              PCIE_SPEED2STR(cls + PCI_SPEED_133MHz_PCIX_533),
> > +              nlw, ssc_good ? "(SSC)" : "(!SSC)");
> > +
> > +     /* PCIe->SCB endian mode for BAR */
> > +     tmp = readl(base + PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1);
> > +     u32p_replace_bits(&tmp, PCIE_RC_CFG_VENDOR_SPCIFIC_REG1_LITTLE_ENDIAN,
> > +             PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1_ENDIAN_MODE_BAR2_MASK);
> > +     writel(tmp, base + PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1);
> > +
> > +     /*
> > +      * Refclk from RC should be gated with CLKREQ# input when ASPM L0s,L1
> > +      * is enabled => setting the CLKREQ_DEBUG_ENABLE field to 1.
> > +      */
> > +     tmp = readl(base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
> > +     tmp |= PCIE_MISC_HARD_PCIE_HARD_DEBUG_CLKREQ_DEBUG_ENABLE_MASK;
> > +     writel(tmp, base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
> > +
> > +     return 0;
> > +}
> > +
> > +/* L23 is a low-power PCIe link state */
> > +static void brcm_pcie_enter_l23(struct brcm_pcie *pcie)
> > +{
> > +     void __iomem *base = pcie->base;
> > +     int l23, i;
> > +     u32 tmp;
> > +
> > +     /* Assert request for L23 */
> > +     tmp = readl(base + PCIE_MISC_PCIE_CTRL);
> > +     u32p_replace_bits(&tmp, 1, PCIE_MISC_PCIE_CTRL_PCIE_L23_REQUEST_MASK);
> > +     writel(tmp, base + PCIE_MISC_PCIE_CTRL);
> > +
> > +     /* Wait up to 36 msec for L23 */
> > +     tmp = readl(base + PCIE_MISC_PCIE_STATUS);
> > +     l23 = FIELD_GET(PCIE_MISC_PCIE_STATUS_PCIE_LINK_IN_L23_MASK, tmp);
> > +     for (i = 0; i < 15 && !l23; i++) {
> > +             usleep_range(2000, 2400);
> > +             tmp = readl(base + PCIE_MISC_PCIE_STATUS);
> > +             l23 = FIELD_GET(PCIE_MISC_PCIE_STATUS_PCIE_LINK_IN_L23_MASK,
> > +                             tmp);
> > +     }
> > +
> > +     if (!l23)
> > +             dev_err(pcie->dev, "failed to enter low-power link state\n");
> > +}
> > +
> > +static void brcm_pcie_turn_off(struct brcm_pcie *pcie)
> > +{
> > +     void __iomem *base = pcie->base;
> > +     int tmp;
> > +
> > +     if (brcm_pcie_link_up(pcie))
> > +             brcm_pcie_enter_l23(pcie);
> > +     /* Assert fundamental reset */
> > +     brcm_pcie_perst_set(pcie, 1);
> > +
> > +     /* Deassert request for L23 in case it was asserted */
> > +     tmp = readl(base + PCIE_MISC_PCIE_CTRL);
> > +     u32p_replace_bits(&tmp, 0, PCIE_MISC_PCIE_CTRL_PCIE_L23_REQUEST_MASK);
> > +     writel(tmp, base + PCIE_MISC_PCIE_CTRL);
> > +
> > +     /* Turn off SerDes */
> > +     tmp = readl(base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
> > +     u32p_replace_bits(&tmp, 1, PCIE_MISC_HARD_PCIE_HARD_DEBUG_SERDES_IDDQ_MASK);
> > +     writel(tmp, base + PCIE_MISC_HARD_PCIE_HARD_DEBUG);
> > +
> > +     /* Shutdown PCIe bridge */
> > +     brcm_pcie_bridge_sw_init_set(pcie, 1);
> > +}
> > +
> > +static void __brcm_pcie_remove(struct brcm_pcie *pcie)
> > +{
> > +     brcm_pcie_turn_off(pcie);
> > +     clk_disable_unprepare(pcie->clk);
> > +     clk_put(pcie->clk);
> > +}
> > +
> > +static int brcm_pcie_remove(struct platform_device *pdev)
> > +{
> > +     struct brcm_pcie *pcie = platform_get_drvdata(pdev);
> > +
> > +     pci_stop_root_bus(pcie->root_bus);
> > +     pci_remove_root_bus(pcie->root_bus);
> > +     __brcm_pcie_remove(pcie);
> > +
> > +     return 0;
> > +}
> > +
> > +static int brcm_pcie_probe(struct platform_device *pdev)
> > +{
> > +     struct device_node *np = pdev->dev.of_node;
> > +     struct pci_host_bridge *bridge;
> > +     struct brcm_pcie *pcie;
> > +     struct pci_bus *child;
> > +     struct resource *res;
> > +     int ret;
> > +
> > +     bridge = devm_pci_alloc_host_bridge(&pdev->dev, sizeof(*pcie));
> > +     if (!bridge)
> > +             return -ENOMEM;
> > +
> > +     pcie = pci_host_bridge_priv(bridge);
> > +     pcie->dev = &pdev->dev;
> > +     pcie->np = np;
> > +
> > +     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > +     pcie->base = devm_ioremap_resource(&pdev->dev, res);
> > +     if (IS_ERR(pcie->base))
> > +             return PTR_ERR(pcie->base);
> > +
> > +     pcie->clk = devm_clk_get_optional(&pdev->dev, "sw_pcie");
> > +     if (IS_ERR(pcie->clk))
> > +             return PTR_ERR(pcie->clk);
> > +
> > +     ret = of_pci_get_max_link_speed(np);
> > +     pcie->gen = (ret < 0) ? 0 : ret;
> > +
> > +     pcie->ssc = of_property_read_bool(np, "brcm,enable-ssc");
> > +
> > +     ret = pci_parse_request_of_pci_ranges(pcie->dev, &bridge->windows,
> > +                                           &bridge->dma_ranges, NULL);
> > +     if (ret)
> > +             return ret;
> > +
> > +     ret = clk_prepare_enable(pcie->clk);
> > +     if (ret) {
> > +             dev_err(&pdev->dev, "could not enable clock\n");
> > +             return ret;
> > +     }
> > +
> > +     ret = brcm_pcie_setup(pcie);
> > +     if (ret)
> > +             goto fail;
> > +
> > +     bridge->dev.parent = &pdev->dev;
> > +     bridge->busnr = 0;
> > +     bridge->ops = &brcm_pcie_ops;
> > +     bridge->sysdata = pcie;
> > +     bridge->map_irq = of_irq_parse_and_map_pci;
> > +     bridge->swizzle_irq = pci_common_swizzle;
> > +
> > +     ret = pci_scan_root_bus_bridge(bridge);
> > +     if (ret < 0) {
> > +             dev_err(pcie->dev, "Scanning root bridge failed\n");
> > +             goto fail;
> > +     }
> > +
> > +     pci_assign_unassigned_bus_resources(bridge->bus);
> > +     list_for_each_entry(child, &bridge->bus->children, node)
> > +             pcie_bus_configure_settings(child);
> > +     pci_bus_add_devices(bridge->bus);
> > +     platform_set_drvdata(pdev, pcie);
> > +     pcie->root_bus = bridge->bus;
> > +
> > +     return 0;
> > +fail:
> > +     __brcm_pcie_remove(pcie);
> > +     return ret;
> > +}
> > +
> > +static const struct of_device_id brcm_pcie_match[] = {
> > +     { .compatible = "brcm,bcm2711-pcie" },
> > +     {},
> > +};
> > +MODULE_DEVICE_TABLE(of, brcm_pcie_match);
> > +
> > +static struct platform_driver brcm_pcie_driver = {
> > +     .probe = brcm_pcie_probe,
> > +     .remove = brcm_pcie_remove,
> > +     .driver = {
> > +             .name = "brcm-pcie",
> > +             .of_match_table = brcm_pcie_match,
> > +     },
> > +};
> > +module_platform_driver(brcm_pcie_driver);
> > +
> > +MODULE_LICENSE("GPL");
> > +MODULE_DESCRIPTION("Broadcom STB PCIe RC driver");
> > +MODULE_AUTHOR("Broadcom");
> > --
> > 2.24.0
> >

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Re: [PATCH v3 2/7] dt-bindings: PCI: Add bindings for brcmstb's PCIe device

[Rob Herring]

On Tue, Nov 26, 2019 at 3:20 AM Nicolas Saenz Julienne
<nsaenzjulienne@suse.de> wrote:
>
> From: Jim Quinlan <james.quinlan@broadcom.com>
>
> The DT bindings description of the brcmstb PCIe device is described.
> This node can only be used for now on the Raspberry Pi 4.
>
> Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>
> Co-developed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
>
> ---
>
> Changes since v2:
>   - Add pci reference schema
>   - Drop all default properties
>   - Assume msi-controller and msi-parent are properly defined
>   - Add num entries on multiple properties
>   - use unevaluatedProperties
>   - Update required properties
>   - Fix license
>
> Changes since v1:
>   - Fix commit Subject
>   - Remove linux,pci-domain
>
> This was based on Jim's original submission[1], converted to yaml and
> adapted to the RPi4 case.
>
> [1] https://patchwork.kernel.org/patch/10605937/
>
>  .../bindings/pci/brcm,stb-pcie.yaml           | 97 +++++++++++++++++++
>  1 file changed, 97 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml

Reviewed-by: Rob Herring <robh@kernel.org>

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Re: [PATCH v3 4/7] PCI: brcmstb: add Broadcom STB PCIe host controller driver

[Jeremy Linton]

Hi,

On 11/26/19 3:19 AM, Nicolas Saenz Julienne wrote:
> From: Jim Quinlan <james.quinlan@broadcom.com>
> 
> This adds a basic driver for Broadcom's STB PCIe controller, for now
> aimed at Raspberry Pi 4's SoC, bcm2711.
> 
> Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>
> Co-developed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> 
> ---
> 
> Changes since v2:
>    - Correct rc_bar2_offset sign
>    - Invert IRQ clear and masking in setup code
>    - Use bitfield.h, redo all register ops while keeping the register
>      names intact
>    - Remove all SHIFT register definitions
>    - Get rid of all _RB writes
>    - Get rid of of_data
>    - Don't iterate over inexisting dma-ranges
>    - Add comment regarding dma-ranges validation
>    - Small cosmetic cleanups
>    - Fix license mismatch
>    - Set driver Kconfig tristate
>    - Didn't add any comment about the controller not being I/O coherent
>      for now as I wait for Jeremy's reply

I guess its fine.. In answer to the original query. It seems that this 
PCIe bridge requires explicit cache operations for DMA from PCIe 
endpoints. This wasn't obvious to me at first reading because I was 
assuming the custom DMA ops were strictly to deal with the stated DMA 
limits.

So if you end up respinning, it still might be worthy mentioning 
somewhere that this is a non-coherent PCIe implementation. I still hold 
much of my original reservations about pieces of this driver. 
Particularly, how it might look if someone wanted to boot the RPi using 
ACPI on linux. But, I was shown a clever bit of AML recently, which 
solves those problems for the RPi and the attached XHCI.

So, given how much time I've looked at the root port configuration/etc 
sections of this driver and I've not found a serious bug:

Reviewed-by: Jeremy Linton <jeremy.linton@arm.com>

> 
> Changes since v1:
>    - Fix Kconfig
>    - Remove pci domain check
>    - Remove all MSI related code
>    - Remove supend/resume code
>    - Simplify link state wait routine
>    - Prefix all functions
>    - Use of_device_get_match_data()
>    - Use devm_clk_get_optional()
>    - Get rid of irq variable
>    - Use STB all over the driver
>    - Simplify map_bus() function
>    - Fix license mismatch
>    - Remove unused register definitions
>    - Small cleanups, spell errors
> 
> This is based on Jim's original submission[1] but adapted and tailored
> specifically to bcm2711's needs (that's the Raspberry Pi 4). Support for
> the rest of the brcmstb family will soon follow once we get support for
> multiple dma-ranges in dma/direct.
> 
> [1] https://patchwork.kernel.org/patch/10605959/
> 
>   drivers/pci/controller/Kconfig        |   8 +
>   drivers/pci/controller/Makefile       |   1 +
>   drivers/pci/controller/pcie-brcmstb.c | 753 ++++++++++++++++++++++++++
>   3 files changed, 762 insertions(+)
>   create mode 100644 drivers/pci/controller/pcie-brcmstb.c
> 

Thanks,


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Re: [PATCH v3 4/7] PCI: brcmstb: add Broadcom STB PCIe host controller driver

[Robin Murphy]

On 03/12/2019 4:31 pm, Jeremy Linton wrote:
> Hi,
> 
> On 11/26/19 3:19 AM, Nicolas Saenz Julienne wrote:
>> From: Jim Quinlan <james.quinlan@broadcom.com>
>>
>> This adds a basic driver for Broadcom's STB PCIe controller, for now
>> aimed at Raspberry Pi 4's SoC, bcm2711.
>>
>> Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>
>> Co-developed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
>> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
>>
>> ---
>>
>> Changes since v2:
>>    - Correct rc_bar2_offset sign
>>    - Invert IRQ clear and masking in setup code
>>    - Use bitfield.h, redo all register ops while keeping the register
>>      names intact
>>    - Remove all SHIFT register definitions
>>    - Get rid of all _RB writes
>>    - Get rid of of_data
>>    - Don't iterate over inexisting dma-ranges
>>    - Add comment regarding dma-ranges validation
>>    - Small cosmetic cleanups
>>    - Fix license mismatch
>>    - Set driver Kconfig tristate
>>    - Didn't add any comment about the controller not being I/O coherent
>>      for now as I wait for Jeremy's reply
> 
> I guess its fine.. In answer to the original query. It seems that this 
> PCIe bridge requires explicit cache operations for DMA from PCIe 
> endpoints. This wasn't obvious to me at first reading because I was 
> assuming the custom DMA ops were strictly to deal with the stated DMA 
> limits.

FWIW, although it might seem anathema to server folks, non-coherent PCI 
is the overwhelming norm in embedded SoCs. Either way, provided the 
presence or absence of coherency is correctly described via the DT 
"dma-coherent" or ACPI _CCA property, then it's transparently handled by 
the DMA API for the endpoint drivers and irrelevant to the host bridge 
itself - after all, in principle the exact same root complex IP could be 
integrated both coherently and non-coherently in different SoCs.

Robin.

> So if you end up respinning, it still might be worthy mentioning 
> somewhere that this is a non-coherent PCIe implementation. I still hold 
> much of my original reservations about pieces of this driver. 
> Particularly, how it might look if someone wanted to boot the RPi using 
> ACPI on linux. But, I was shown a clever bit of AML recently, which 
> solves those problems for the RPi and the attached XHCI.
> 
> So, given how much time I've looked at the root port configuration/etc 
> sections of this driver and I've not found a serious bug:
> 
> Reviewed-by: Jeremy Linton <jeremy.linton@arm.com>
> 
>>
>> Changes since v1:
>>    - Fix Kconfig
>>    - Remove pci domain check
>>    - Remove all MSI related code
>>    - Remove supend/resume code
>>    - Simplify link state wait routine
>>    - Prefix all functions
>>    - Use of_device_get_match_data()
>>    - Use devm_clk_get_optional()
>>    - Get rid of irq variable
>>    - Use STB all over the driver
>>    - Simplify map_bus() function
>>    - Fix license mismatch
>>    - Remove unused register definitions
>>    - Small cleanups, spell errors
>>
>> This is based on Jim's original submission[1] but adapted and tailored
>> specifically to bcm2711's needs (that's the Raspberry Pi 4). Support for
>> the rest of the brcmstb family will soon follow once we get support for
>> multiple dma-ranges in dma/direct.
>>
>> [1] https://patchwork.kernel.org/patch/10605959/
>>
>>   drivers/pci/controller/Kconfig        |   8 +
>>   drivers/pci/controller/Makefile       |   1 +
>>   drivers/pci/controller/pcie-brcmstb.c | 753 ++++++++++++++++++++++++++
>>   3 files changed, 762 insertions(+)
>>   create mode 100644 drivers/pci/controller/pcie-brcmstb.c
>>
> 
> Thanks,
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

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Re: [PATCH v3 4/7] PCI: brcmstb: add Broadcom STB PCIe host controller driver

[Nicolas Saenz Julienne]

[-- Attachment #1.1: Type: text/plain, Size: 2430 bytes --]

On Tue, 2019-12-03 at 10:31 -0600, Jeremy Linton wrote:
> Hi,
> 
> On 11/26/19 3:19 AM, Nicolas Saenz Julienne wrote:
> > From: Jim Quinlan <james.quinlan@broadcom.com>
> > 
> > This adds a basic driver for Broadcom's STB PCIe controller, for now
> > aimed at Raspberry Pi 4's SoC, bcm2711.
> > 
> > Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>
> > Co-developed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> > Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> > 
> > ---
> > 
> > Changes since v2:
> >    - Correct rc_bar2_offset sign
> >    - Invert IRQ clear and masking in setup code
> >    - Use bitfield.h, redo all register ops while keeping the register
> >      names intact
> >    - Remove all SHIFT register definitions
> >    - Get rid of all _RB writes
> >    - Get rid of of_data
> >    - Don't iterate over inexisting dma-ranges
> >    - Add comment regarding dma-ranges validation
> >    - Small cosmetic cleanups
> >    - Fix license mismatch
> >    - Set driver Kconfig tristate
> >    - Didn't add any comment about the controller not being I/O coherent
> >      for now as I wait for Jeremy's reply
> 
> I guess its fine.. In answer to the original query. It seems that this 
> PCIe bridge requires explicit cache operations for DMA from PCIe 
> endpoints. This wasn't obvious to me at first reading because I was 
> assuming the custom DMA ops were strictly to deal with the stated DMA 
> limits.

Thanks, I now see what you meant.

> So if you end up respinning, it still might be worthy mentioning 
> somewhere that this is a non-coherent PCIe implementation. I still hold 
> much of my original reservations about pieces of this driver. 
> Particularly, how it might look if someone wanted to boot the RPi using 
> ACPI on linux. But, I was shown a clever bit of AML recently, which 
> solves those problems for the RPi and the attached XHCI.

I don't know much about ACPI, but ultimately if you're booting trough ACPI,
you're unlikely to use device-tree at all, right? And if you where and this
driver clashed with your ACPI implementation you'd simply have to disable it on
the device-tree.

> So, given how much time I've looked at the root port configuration/etc 
> sections of this driver and I've not found a serious bug:
> 
> Reviewed-by: Jeremy Linton <jeremy.linton@arm.com>

Thanks!

Regards,
Nicolas


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