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* [RFC PATCH v3 0/8] RISC-V CPU Idle Support
@ 2021-03-18 13:05 Anup Patel
  2021-03-18 13:05 ` [RFC PATCH v3 1/8] RISC-V: Enable CPU_IDLE drivers Anup Patel
                   ` (7 more replies)
  0 siblings, 8 replies; 12+ messages in thread
From: Anup Patel @ 2021-03-18 13:05 UTC (permalink / raw)
  To: Palmer Dabbelt, Palmer Dabbelt, Paul Walmsley, Albert Ou,
	Daniel Lezcano, Ulf Hansson, Rafael J . Wysocki, Pavel Machek,
	Rob Herring
  Cc: Sandeep Tripathy, Atish Patra, Alistair Francis, Liush,
	Anup Patel, devicetree, linux-riscv, linux-kernel, linux-pm,
	linux-arm-kernel, Anup Patel

This series adds RISC-V CPU Idle support using SBI HSM suspend function.
The RISC-V SBI CPU idle driver added by this series is highly inspired
from the ARM PSCI CPU idle driver.

At high-level, this series includes the following changes:
1) Preparatory arch/riscv patches (Patches 1 to 3)
2) Defines for RISC-V SBI HSM suspend (Patch 4)
3) Preparatory patch to share code between RISC-V SBI CPU idle driver
   and ARM PSCI CPU idle driver (Patch 5)
4) RISC-V SBI CPU idle driver and related DT bindings (Patches 6 to 7)

These patches can be found in riscv_sbi_hsm_suspend_v3 branch at
https://github.com/avpatel/linux

Special thanks Sandeep Tripathy for providing early feeback on SBI HSM
support in all above projects (RISC-V SBI specification, OpenSBI, and
Linux RISC-V).

Changes since v2:
 - Rebased on Linux-5.12-rc3
 - Updated PATCH7 to add common DT bindings for both ARM and RISC-V
   idle states
 - Added "additionalProperties = false" for both idle-states node and
   child nodes in PATCH7

Changes since v1:
 - Fixex minor typo in PATCH1
 - Use just "idle-states" as DT node name for CPU idle states
 - Added documentation for "cpu-idle-states" DT property in
   devicetree/bindings/riscv/cpus.yaml
 - Added documentation for "riscv,sbi-suspend-param" DT property in
   devicetree/bindings/riscv/idle-states.yaml

Anup Patel (8):
  RISC-V: Enable CPU_IDLE drivers
  RISC-V: Rename relocate() and make it global
  RISC-V: Add arch functions for non-retentive suspend entry/exit
  RISC-V: Add SBI HSM suspend related defines
  cpuidle: Factor-out power domain related code from PSCI domain driver
  cpuidle: Add RISC-V SBI CPU idle driver
  dt-bindings: Add common bindings for ARM and RISC-V idle states
  RISC-V: Enable RISC-V SBI CPU Idle driver for QEMU virt machine

 .../bindings/{arm => cpu}/idle-states.yaml    | 228 +++++++-
 .../devicetree/bindings/riscv/cpus.yaml       |   6 +
 MAINTAINERS                                   |   8 +
 arch/riscv/Kconfig                            |   7 +
 arch/riscv/Kconfig.socs                       |   3 +
 arch/riscv/configs/defconfig                  |   8 +-
 arch/riscv/configs/rv32_defconfig             |   5 +-
 arch/riscv/include/asm/cpuidle.h              |  24 +
 arch/riscv/include/asm/sbi.h                  |  27 +-
 arch/riscv/include/asm/suspend.h              |  35 ++
 arch/riscv/kernel/Makefile                    |   2 +
 arch/riscv/kernel/asm-offsets.c               |   3 +
 arch/riscv/kernel/cpu_ops_sbi.c               |   2 +-
 arch/riscv/kernel/head.S                      |   7 +-
 arch/riscv/kernel/process.c                   |   3 +-
 arch/riscv/kernel/suspend.c                   |  86 +++
 arch/riscv/kernel/suspend_entry.S             | 116 ++++
 drivers/cpuidle/Kconfig                       |   9 +
 drivers/cpuidle/Kconfig.arm                   |   1 +
 drivers/cpuidle/Kconfig.riscv                 |  15 +
 drivers/cpuidle/Makefile                      |   5 +
 drivers/cpuidle/cpuidle-psci-domain.c         | 244 +--------
 drivers/cpuidle/cpuidle-psci.h                |  15 +-
 drivers/cpuidle/cpuidle-sbi.c                 | 502 ++++++++++++++++++
 ...{cpuidle-psci-domain.c => dt_idle_genpd.c} | 165 ++----
 drivers/cpuidle/dt_idle_genpd.h               |  42 ++
 26 files changed, 1184 insertions(+), 384 deletions(-)
 rename Documentation/devicetree/bindings/{arm => cpu}/idle-states.yaml (74%)
 create mode 100644 arch/riscv/include/asm/cpuidle.h
 create mode 100644 arch/riscv/include/asm/suspend.h
 create mode 100644 arch/riscv/kernel/suspend.c
 create mode 100644 arch/riscv/kernel/suspend_entry.S
 create mode 100644 drivers/cpuidle/Kconfig.riscv
 create mode 100644 drivers/cpuidle/cpuidle-sbi.c
 copy drivers/cpuidle/{cpuidle-psci-domain.c => dt_idle_genpd.c} (52%)
 create mode 100644 drivers/cpuidle/dt_idle_genpd.h

-- 
2.25.1


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^ permalink raw reply	[flat|nested] 12+ messages in thread

* [RFC PATCH v3 1/8] RISC-V: Enable CPU_IDLE drivers
  2021-03-18 13:05 [RFC PATCH v3 0/8] RISC-V CPU Idle Support Anup Patel
@ 2021-03-18 13:05 ` Anup Patel
  2021-03-18 13:05 ` [RFC PATCH v3 2/8] RISC-V: Rename relocate() and make it global Anup Patel
                   ` (6 subsequent siblings)
  7 siblings, 0 replies; 12+ messages in thread
From: Anup Patel @ 2021-03-18 13:05 UTC (permalink / raw)
  To: Palmer Dabbelt, Palmer Dabbelt, Paul Walmsley, Albert Ou,
	Daniel Lezcano, Ulf Hansson, Rafael J . Wysocki, Pavel Machek,
	Rob Herring
  Cc: Sandeep Tripathy, Atish Patra, Alistair Francis, Liush,
	Anup Patel, devicetree, linux-riscv, linux-kernel, linux-pm,
	linux-arm-kernel, Anup Patel

We force select CPU_PM and provide asm/cpuidle.h so that we can
use CPU IDLE drivers for Linux RISC-V kernel.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
---
 arch/riscv/Kconfig                |  7 +++++++
 arch/riscv/configs/defconfig      |  7 +++----
 arch/riscv/configs/rv32_defconfig |  4 ++--
 arch/riscv/include/asm/cpuidle.h  | 24 ++++++++++++++++++++++++
 arch/riscv/kernel/process.c       |  3 ++-
 5 files changed, 38 insertions(+), 7 deletions(-)
 create mode 100644 arch/riscv/include/asm/cpuidle.h

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 468642c4e92f..19c9ae909001 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -37,6 +37,7 @@ config RISCV
 	select CLONE_BACKWARDS
 	select CLINT_TIMER if !MMU
 	select COMMON_CLK
+	select CPU_PM if CPU_IDLE
 	select EDAC_SUPPORT
 	select GENERIC_ARCH_TOPOLOGY if SMP
 	select GENERIC_ATOMIC64 if !64BIT
@@ -475,4 +476,10 @@ source "kernel/power/Kconfig"
 
 endmenu
 
+menu "CPU Power Management"
+
+source "drivers/cpuidle/Kconfig"
+
+endmenu
+
 source "drivers/firmware/Kconfig"
diff --git a/arch/riscv/configs/defconfig b/arch/riscv/configs/defconfig
index 6c0625aa96c7..dc4927c0e44b 100644
--- a/arch/riscv/configs/defconfig
+++ b/arch/riscv/configs/defconfig
@@ -13,11 +13,13 @@ CONFIG_USER_NS=y
 CONFIG_CHECKPOINT_RESTORE=y
 CONFIG_BLK_DEV_INITRD=y
 CONFIG_EXPERT=y
+# CONFIG_SYSFS_SYSCALL is not set
 CONFIG_BPF_SYSCALL=y
 CONFIG_SOC_SIFIVE=y
 CONFIG_SOC_VIRT=y
 CONFIG_SMP=y
 CONFIG_HOTPLUG_CPU=y
+CONFIG_CPU_IDLE=y
 CONFIG_JUMP_LABEL=y
 CONFIG_MODULES=y
 CONFIG_MODULE_UNLOAD=y
@@ -65,10 +67,9 @@ CONFIG_HW_RANDOM=y
 CONFIG_HW_RANDOM_VIRTIO=y
 CONFIG_SPI=y
 CONFIG_SPI_SIFIVE=y
+# CONFIG_PTP_1588_CLOCK is not set
 CONFIG_GPIOLIB=y
 CONFIG_GPIO_SIFIVE=y
-# CONFIG_PTP_1588_CLOCK is not set
-CONFIG_POWER_RESET=y
 CONFIG_DRM=y
 CONFIG_DRM_RADEON=y
 CONFIG_DRM_VIRTIO_GPU=y
@@ -132,5 +133,3 @@ CONFIG_DEBUG_BLOCK_EXT_DEVT=y
 # CONFIG_FTRACE is not set
 # CONFIG_RUNTIME_TESTING_MENU is not set
 CONFIG_MEMTEST=y
-# CONFIG_SYSFS_SYSCALL is not set
-CONFIG_EFI=y
diff --git a/arch/riscv/configs/rv32_defconfig b/arch/riscv/configs/rv32_defconfig
index 8dd02b842fef..332e43a4a2c3 100644
--- a/arch/riscv/configs/rv32_defconfig
+++ b/arch/riscv/configs/rv32_defconfig
@@ -13,12 +13,14 @@ CONFIG_USER_NS=y
 CONFIG_CHECKPOINT_RESTORE=y
 CONFIG_BLK_DEV_INITRD=y
 CONFIG_EXPERT=y
+# CONFIG_SYSFS_SYSCALL is not set
 CONFIG_BPF_SYSCALL=y
 CONFIG_SOC_SIFIVE=y
 CONFIG_SOC_VIRT=y
 CONFIG_ARCH_RV32I=y
 CONFIG_SMP=y
 CONFIG_HOTPLUG_CPU=y
+CONFIG_CPU_IDLE=y
 CONFIG_JUMP_LABEL=y
 CONFIG_MODULES=y
 CONFIG_MODULE_UNLOAD=y
@@ -67,7 +69,6 @@ CONFIG_HW_RANDOM_VIRTIO=y
 CONFIG_SPI=y
 CONFIG_SPI_SIFIVE=y
 # CONFIG_PTP_1588_CLOCK is not set
-CONFIG_POWER_RESET=y
 CONFIG_DRM=y
 CONFIG_DRM_RADEON=y
 CONFIG_DRM_VIRTIO_GPU=y
@@ -131,4 +132,3 @@ CONFIG_DEBUG_BLOCK_EXT_DEVT=y
 # CONFIG_FTRACE is not set
 # CONFIG_RUNTIME_TESTING_MENU is not set
 CONFIG_MEMTEST=y
-# CONFIG_SYSFS_SYSCALL is not set
diff --git a/arch/riscv/include/asm/cpuidle.h b/arch/riscv/include/asm/cpuidle.h
new file mode 100644
index 000000000000..71fdc607d4bc
--- /dev/null
+++ b/arch/riscv/include/asm/cpuidle.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2021 Allwinner Ltd
+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
+ */
+
+#ifndef _ASM_RISCV_CPUIDLE_H
+#define _ASM_RISCV_CPUIDLE_H
+
+#include <asm/barrier.h>
+#include <asm/processor.h>
+
+static inline void cpu_do_idle(void)
+{
+	/*
+	 * Add mb() here to ensure that all
+	 * IO/MEM accesses are completed prior
+	 * to entering WFI.
+	 */
+	mb();
+	wait_for_interrupt();
+}
+
+#endif
diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
index 6f728e731bed..dd2ef18517f4 100644
--- a/arch/riscv/kernel/process.c
+++ b/arch/riscv/kernel/process.c
@@ -22,6 +22,7 @@
 #include <asm/string.h>
 #include <asm/switch_to.h>
 #include <asm/thread_info.h>
+#include <asm/cpuidle.h>
 
 register unsigned long gp_in_global __asm__("gp");
 
@@ -36,7 +37,7 @@ extern asmlinkage void ret_from_kernel_thread(void);
 
 void arch_cpu_idle(void)
 {
-	wait_for_interrupt();
+	cpu_do_idle();
 	raw_local_irq_enable();
 }
 
-- 
2.25.1


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^ permalink raw reply	[flat|nested] 12+ messages in thread

* [RFC PATCH v3 2/8] RISC-V: Rename relocate() and make it global
  2021-03-18 13:05 [RFC PATCH v3 0/8] RISC-V CPU Idle Support Anup Patel
  2021-03-18 13:05 ` [RFC PATCH v3 1/8] RISC-V: Enable CPU_IDLE drivers Anup Patel
@ 2021-03-18 13:05 ` Anup Patel
  2021-03-18 13:05 ` [RFC PATCH v3 3/8] RISC-V: Add arch functions for non-retentive suspend entry/exit Anup Patel
                   ` (5 subsequent siblings)
  7 siblings, 0 replies; 12+ messages in thread
From: Anup Patel @ 2021-03-18 13:05 UTC (permalink / raw)
  To: Palmer Dabbelt, Palmer Dabbelt, Paul Walmsley, Albert Ou,
	Daniel Lezcano, Ulf Hansson, Rafael J . Wysocki, Pavel Machek,
	Rob Herring
  Cc: Sandeep Tripathy, Atish Patra, Alistair Francis, Liush,
	Anup Patel, devicetree, linux-riscv, linux-kernel, linux-pm,
	linux-arm-kernel, Anup Patel

The low-level relocate() function enables mmu and relocates
execution to link-time addresses. We rename relocate() function
to relocate_enable_mmu() function which is more informative.

Also, the relocate_enable_mmu() function will be used in the
resume path when a CPU wakes-up from a non-retentive suspend
so we make it global symbol.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
---
 arch/riscv/kernel/head.S | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S
index f5a9bad86e58..9d10f89e8ab7 100644
--- a/arch/riscv/kernel/head.S
+++ b/arch/riscv/kernel/head.S
@@ -67,7 +67,8 @@ pe_head_start:
 
 .align 2
 #ifdef CONFIG_MMU
-relocate:
+	.global relocate_enable_mmu
+relocate_enable_mmu:
 	/* Relocate return address */
 	li a1, PAGE_OFFSET
 	la a2, _start
@@ -156,7 +157,7 @@ secondary_start_common:
 #ifdef CONFIG_MMU
 	/* Enable virtual memory and relocate to virtual address */
 	la a0, swapper_pg_dir
-	call relocate
+	call relocate_enable_mmu
 #endif
 	call setup_trap_vector
 	tail smp_callin
@@ -268,7 +269,7 @@ clear_bss_done:
 	call setup_vm
 #ifdef CONFIG_MMU
 	la a0, early_pg_dir
-	call relocate
+	call relocate_enable_mmu
 #endif /* CONFIG_MMU */
 
 	call setup_trap_vector
-- 
2.25.1


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^ permalink raw reply	[flat|nested] 12+ messages in thread

* [RFC PATCH v3 3/8] RISC-V: Add arch functions for non-retentive suspend entry/exit
  2021-03-18 13:05 [RFC PATCH v3 0/8] RISC-V CPU Idle Support Anup Patel
  2021-03-18 13:05 ` [RFC PATCH v3 1/8] RISC-V: Enable CPU_IDLE drivers Anup Patel
  2021-03-18 13:05 ` [RFC PATCH v3 2/8] RISC-V: Rename relocate() and make it global Anup Patel
@ 2021-03-18 13:05 ` Anup Patel
  2021-03-18 13:05 ` [RFC PATCH v3 4/8] RISC-V: Add SBI HSM suspend related defines Anup Patel
                   ` (4 subsequent siblings)
  7 siblings, 0 replies; 12+ messages in thread
From: Anup Patel @ 2021-03-18 13:05 UTC (permalink / raw)
  To: Palmer Dabbelt, Palmer Dabbelt, Paul Walmsley, Albert Ou,
	Daniel Lezcano, Ulf Hansson, Rafael J . Wysocki, Pavel Machek,
	Rob Herring
  Cc: Sandeep Tripathy, Atish Patra, Alistair Francis, Liush,
	Anup Patel, devicetree, linux-riscv, linux-kernel, linux-pm,
	linux-arm-kernel, Anup Patel

The hart registers and CSRs are not preserved in non-retentative
suspend state so we provide arch specific helper functions which
will save/restore hart context upon entry/exit to non-retentive
suspend state. These helper functions can be used by cpuidle
drivers for non-retentive suspend entry/exit.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
---
 arch/riscv/include/asm/suspend.h  |  35 +++++++++
 arch/riscv/kernel/Makefile        |   2 +
 arch/riscv/kernel/asm-offsets.c   |   3 +
 arch/riscv/kernel/suspend.c       |  86 ++++++++++++++++++++++
 arch/riscv/kernel/suspend_entry.S | 116 ++++++++++++++++++++++++++++++
 5 files changed, 242 insertions(+)
 create mode 100644 arch/riscv/include/asm/suspend.h
 create mode 100644 arch/riscv/kernel/suspend.c
 create mode 100644 arch/riscv/kernel/suspend_entry.S

diff --git a/arch/riscv/include/asm/suspend.h b/arch/riscv/include/asm/suspend.h
new file mode 100644
index 000000000000..63e9f434fb89
--- /dev/null
+++ b/arch/riscv/include/asm/suspend.h
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2021 Western Digital Corporation or its affiliates.
+ */
+
+#ifndef _ASM_RISCV_SUSPEND_H
+#define _ASM_RISCV_SUSPEND_H
+
+#include <asm/ptrace.h>
+
+struct suspend_context {
+	/* Saved and restored by low-level functions */
+	struct pt_regs regs;
+	/* Saved and restored by high-level functions */
+	unsigned long scratch;
+	unsigned long tvec;
+	unsigned long ie;
+#ifdef CONFIG_MMU
+	unsigned long satp;
+#endif
+};
+
+/* Low-level CPU suspend entry function */
+int __cpu_suspend_enter(struct suspend_context *context);
+
+/* High-level CPU suspend which will save context and call finish() */
+int cpu_suspend(unsigned long arg,
+		int (*finish)(unsigned long arg,
+			      unsigned long entry,
+			      unsigned long context));
+
+/* Low-level CPU resume entry function */
+int __cpu_resume_enter(unsigned long hartid, unsigned long context);
+
+#endif
diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
index 3dc0abde988a..b9b1b05ab860 100644
--- a/arch/riscv/kernel/Makefile
+++ b/arch/riscv/kernel/Makefile
@@ -42,6 +42,8 @@ obj-$(CONFIG_SMP)		+= cpu_ops_spinwait.o
 obj-$(CONFIG_MODULES)		+= module.o
 obj-$(CONFIG_MODULE_SECTIONS)	+= module-sections.o
 
+obj-$(CONFIG_CPU_PM)		+= suspend_entry.o suspend.o
+
 obj-$(CONFIG_FUNCTION_TRACER)	+= mcount.o ftrace.o
 obj-$(CONFIG_DYNAMIC_FTRACE)	+= mcount-dyn.o
 
diff --git a/arch/riscv/kernel/asm-offsets.c b/arch/riscv/kernel/asm-offsets.c
index 9ef33346853c..2628dfd0f77d 100644
--- a/arch/riscv/kernel/asm-offsets.c
+++ b/arch/riscv/kernel/asm-offsets.c
@@ -10,6 +10,7 @@
 #include <linux/sched.h>
 #include <asm/thread_info.h>
 #include <asm/ptrace.h>
+#include <asm/suspend.h>
 
 void asm_offsets(void);
 
@@ -111,6 +112,8 @@ void asm_offsets(void)
 	OFFSET(PT_BADADDR, pt_regs, badaddr);
 	OFFSET(PT_CAUSE, pt_regs, cause);
 
+	OFFSET(SUSPEND_CONTEXT_REGS, suspend_context, regs);
+
 	/*
 	 * THREAD_{F,X}* might be larger than a S-type offset can handle, but
 	 * these are used in performance-sensitive assembly so we can't resort
diff --git a/arch/riscv/kernel/suspend.c b/arch/riscv/kernel/suspend.c
new file mode 100644
index 000000000000..49dddec30e99
--- /dev/null
+++ b/arch/riscv/kernel/suspend.c
@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2021 Western Digital Corporation or its affiliates.
+ */
+
+#include <linux/ftrace.h>
+#include <asm/csr.h>
+#include <asm/suspend.h>
+
+static void suspend_save_csrs(struct suspend_context *context)
+{
+	context->scratch = csr_read(CSR_SCRATCH);
+	context->tvec = csr_read(CSR_TVEC);
+	context->ie = csr_read(CSR_IE);
+
+	/*
+	 * No need to save/restore IP CSR (i.e. MIP or SIP) because:
+	 *
+	 * 1. For no-MMU (M-mode) kernel, the bits in MIP are set by
+	 *    external devices (such as interrupt controller, timer, etc).
+	 * 2. For MMU (S-mode) kernel, the bits in SIP are set by
+	 *    M-mode firmware and external devices (such as interrupt
+	 *    controller, etc).
+	 */
+
+#ifdef CONFIG_MMU
+	context->satp = csr_read(CSR_SATP);
+#endif
+}
+
+static void suspend_restore_csrs(struct suspend_context *context)
+{
+	csr_write(CSR_SCRATCH, context->scratch);
+	csr_write(CSR_TVEC, context->tvec);
+	csr_write(CSR_IE, context->ie);
+
+#ifdef CONFIG_MMU
+	csr_write(CSR_SATP, context->satp);
+#endif
+}
+
+int cpu_suspend(unsigned long arg,
+		int (*finish)(unsigned long arg,
+			      unsigned long entry,
+			      unsigned long context))
+{
+	int rc = 0;
+	struct suspend_context context = { 0 };
+
+	/* Finisher should be non-NULL */
+	if (!finish)
+		return -EINVAL;
+
+	/* Save additional CSRs*/
+	suspend_save_csrs(&context);
+
+	/*
+	 * Function graph tracer state gets incosistent when the kernel
+	 * calls functions that never return (aka finishers) hence disable
+	 * graph tracing during their execution.
+	 */
+	pause_graph_tracing();
+
+	/* Save context on stack */
+	if (__cpu_suspend_enter(&context)) {
+		/* Call the finisher */
+		rc = finish(arg, __pa_symbol(__cpu_resume_enter),
+			    (ulong)&context);
+
+		/*
+		 * Should never reach here, unless the suspend finisher
+		 * fails. Successful cpu_suspend() should return from
+		 * __cpu_resume_entry()
+		 */
+		if (!rc)
+			rc = -EOPNOTSUPP;
+	}
+
+	/* Enable function graph tracer */
+	unpause_graph_tracing();
+
+	/* Restore additional CSRs */
+	suspend_restore_csrs(&context);
+
+	return rc;
+}
diff --git a/arch/riscv/kernel/suspend_entry.S b/arch/riscv/kernel/suspend_entry.S
new file mode 100644
index 000000000000..dee85c86e177
--- /dev/null
+++ b/arch/riscv/kernel/suspend_entry.S
@@ -0,0 +1,116 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2021 Western Digital Corporation or its affiliates.
+ */
+
+#include <linux/linkage.h>
+#include <asm/asm.h>
+#include <asm/asm-offsets.h>
+#include <asm/csr.h>
+
+	.text
+	.altmacro
+	.option norelax
+
+ENTRY(__cpu_suspend_enter)
+	/* Save registers (except A0 and T0-T6) */
+	REG_S	ra, (SUSPEND_CONTEXT_REGS + PT_RA)(a0)
+	REG_S	sp, (SUSPEND_CONTEXT_REGS + PT_SP)(a0)
+	REG_S	gp, (SUSPEND_CONTEXT_REGS + PT_GP)(a0)
+	REG_S	tp, (SUSPEND_CONTEXT_REGS + PT_TP)(a0)
+	REG_S	s0, (SUSPEND_CONTEXT_REGS + PT_S0)(a0)
+	REG_S	s1, (SUSPEND_CONTEXT_REGS + PT_S1)(a0)
+	REG_S	a1, (SUSPEND_CONTEXT_REGS + PT_A1)(a0)
+	REG_S	a2, (SUSPEND_CONTEXT_REGS + PT_A2)(a0)
+	REG_S	a3, (SUSPEND_CONTEXT_REGS + PT_A3)(a0)
+	REG_S	a4, (SUSPEND_CONTEXT_REGS + PT_A4)(a0)
+	REG_S	a5, (SUSPEND_CONTEXT_REGS + PT_A5)(a0)
+	REG_S	a6, (SUSPEND_CONTEXT_REGS + PT_A6)(a0)
+	REG_S	a7, (SUSPEND_CONTEXT_REGS + PT_A7)(a0)
+	REG_S	s2, (SUSPEND_CONTEXT_REGS + PT_S2)(a0)
+	REG_S	s3, (SUSPEND_CONTEXT_REGS + PT_S3)(a0)
+	REG_S	s4, (SUSPEND_CONTEXT_REGS + PT_S4)(a0)
+	REG_S	s5, (SUSPEND_CONTEXT_REGS + PT_S5)(a0)
+	REG_S	s6, (SUSPEND_CONTEXT_REGS + PT_S6)(a0)
+	REG_S	s7, (SUSPEND_CONTEXT_REGS + PT_S7)(a0)
+	REG_S	s8, (SUSPEND_CONTEXT_REGS + PT_S8)(a0)
+	REG_S	s9, (SUSPEND_CONTEXT_REGS + PT_S9)(a0)
+	REG_S	s10, (SUSPEND_CONTEXT_REGS + PT_S10)(a0)
+	REG_S	s11, (SUSPEND_CONTEXT_REGS + PT_S11)(a0)
+
+	/* Save CSRs */
+	csrr	t0, CSR_EPC
+	REG_S	t0, (SUSPEND_CONTEXT_REGS + PT_EPC)(a0)
+	csrr	t0, CSR_STATUS
+	REG_S	t0, (SUSPEND_CONTEXT_REGS + PT_STATUS)(a0)
+	csrr	t0, CSR_TVAL
+	REG_S	t0, (SUSPEND_CONTEXT_REGS + PT_BADADDR)(a0)
+	csrr	t0, CSR_CAUSE
+	REG_S	t0, (SUSPEND_CONTEXT_REGS + PT_CAUSE)(a0)
+
+	/* Return non-zero value */
+	li	a0, 1
+
+	/* Return to C code */
+	ret
+END(__cpu_suspend_enter)
+
+ENTRY(__cpu_resume_enter)
+#ifdef CONFIG_MMU
+	/* Save A0 and A1 */
+	add	t0, a0, zero
+	add	t1, a1, zero
+
+	/* Enable MMU */
+	la	a0, swapper_pg_dir
+	call	relocate_enable_mmu
+
+	/* Restore A0 and A1 */
+	add	a0, t0, zero
+	add	a1, t1, zero
+#endif
+
+	/* Make A0 point to suspend context */
+	add	a0, a1, zero
+
+	/* Restore CSRs */
+	REG_L	t0, (SUSPEND_CONTEXT_REGS + PT_EPC)(a0)
+	csrw	CSR_EPC, t0
+	REG_L	t0, (SUSPEND_CONTEXT_REGS + PT_STATUS)(a0)
+	csrw	CSR_STATUS, t0
+	REG_L	t0, (SUSPEND_CONTEXT_REGS + PT_BADADDR)(a0)
+	csrw	CSR_TVAL, t0
+	REG_L	t0, (SUSPEND_CONTEXT_REGS + PT_CAUSE)(a0)
+	csrw	CSR_CAUSE, t0
+
+	/* Restore registers (except A0 and T0-T6) */
+	REG_L	ra, (SUSPEND_CONTEXT_REGS + PT_RA)(a0)
+	REG_L	sp, (SUSPEND_CONTEXT_REGS + PT_SP)(a0)
+	REG_L	gp, (SUSPEND_CONTEXT_REGS + PT_GP)(a0)
+	REG_L	tp, (SUSPEND_CONTEXT_REGS + PT_TP)(a0)
+	REG_L	s0, (SUSPEND_CONTEXT_REGS + PT_S0)(a0)
+	REG_L	s1, (SUSPEND_CONTEXT_REGS + PT_S1)(a0)
+	REG_L	a1, (SUSPEND_CONTEXT_REGS + PT_A1)(a0)
+	REG_L	a2, (SUSPEND_CONTEXT_REGS + PT_A2)(a0)
+	REG_L	a3, (SUSPEND_CONTEXT_REGS + PT_A3)(a0)
+	REG_L	a4, (SUSPEND_CONTEXT_REGS + PT_A4)(a0)
+	REG_L	a5, (SUSPEND_CONTEXT_REGS + PT_A5)(a0)
+	REG_L	a6, (SUSPEND_CONTEXT_REGS + PT_A6)(a0)
+	REG_L	a7, (SUSPEND_CONTEXT_REGS + PT_A7)(a0)
+	REG_L	s2, (SUSPEND_CONTEXT_REGS + PT_S2)(a0)
+	REG_L	s3, (SUSPEND_CONTEXT_REGS + PT_S3)(a0)
+	REG_L	s4, (SUSPEND_CONTEXT_REGS + PT_S4)(a0)
+	REG_L	s5, (SUSPEND_CONTEXT_REGS + PT_S5)(a0)
+	REG_L	s6, (SUSPEND_CONTEXT_REGS + PT_S6)(a0)
+	REG_L	s7, (SUSPEND_CONTEXT_REGS + PT_S7)(a0)
+	REG_L	s8, (SUSPEND_CONTEXT_REGS + PT_S8)(a0)
+	REG_L	s9, (SUSPEND_CONTEXT_REGS + PT_S9)(a0)
+	REG_L	s10, (SUSPEND_CONTEXT_REGS + PT_S10)(a0)
+	REG_L	s11, (SUSPEND_CONTEXT_REGS + PT_S11)(a0)
+
+	/* Return zero value */
+	add	a0, zero, zero
+
+	/* Return to C code */
+	ret
+END(__cpu_resume_enter)
-- 
2.25.1


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^ permalink raw reply	[flat|nested] 12+ messages in thread

* [RFC PATCH v3 4/8] RISC-V: Add SBI HSM suspend related defines
  2021-03-18 13:05 [RFC PATCH v3 0/8] RISC-V CPU Idle Support Anup Patel
                   ` (2 preceding siblings ...)
  2021-03-18 13:05 ` [RFC PATCH v3 3/8] RISC-V: Add arch functions for non-retentive suspend entry/exit Anup Patel
@ 2021-03-18 13:05 ` Anup Patel
  2021-03-18 13:05 ` [RFC PATCH v3 5/8] cpuidle: Factor-out power domain related code from PSCI domain driver Anup Patel
                   ` (3 subsequent siblings)
  7 siblings, 0 replies; 12+ messages in thread
From: Anup Patel @ 2021-03-18 13:05 UTC (permalink / raw)
  To: Palmer Dabbelt, Palmer Dabbelt, Paul Walmsley, Albert Ou,
	Daniel Lezcano, Ulf Hansson, Rafael J . Wysocki, Pavel Machek,
	Rob Herring
  Cc: Sandeep Tripathy, Atish Patra, Alistair Francis, Liush,
	Anup Patel, devicetree, linux-riscv, linux-kernel, linux-pm,
	linux-arm-kernel, Anup Patel

We add defines related to SBI HSM suspend call and also
update HSM states naming as-per latest SBI specification.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
---
 arch/riscv/include/asm/sbi.h    | 27 ++++++++++++++++++++++-----
 arch/riscv/kernel/cpu_ops_sbi.c |  2 +-
 2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h
index 79fa9f28b786..4bdccec77a84 100644
--- a/arch/riscv/include/asm/sbi.h
+++ b/arch/riscv/include/asm/sbi.h
@@ -62,15 +62,32 @@ enum sbi_ext_hsm_fid {
 	SBI_EXT_HSM_HART_START = 0,
 	SBI_EXT_HSM_HART_STOP,
 	SBI_EXT_HSM_HART_STATUS,
+	SBI_EXT_HSM_HART_SUSPEND,
 };
 
-enum sbi_hsm_hart_status {
-	SBI_HSM_HART_STATUS_STARTED = 0,
-	SBI_HSM_HART_STATUS_STOPPED,
-	SBI_HSM_HART_STATUS_START_PENDING,
-	SBI_HSM_HART_STATUS_STOP_PENDING,
+enum sbi_hsm_hart_state {
+	SBI_HSM_STATE_STARTED = 0,
+	SBI_HSM_STATE_STOPPED,
+	SBI_HSM_STATE_START_PENDING,
+	SBI_HSM_STATE_STOP_PENDING,
+	SBI_HSM_STATE_SUSPENDED,
+	SBI_HSM_STATE_SUSPEND_PENDING,
+	SBI_HSM_STATE_RESUME_PENDING,
 };
 
+#define SBI_HSM_SUSP_BASE_MASK			0x7fffffff
+#define SBI_HSM_SUSP_NON_RET_BIT		0x80000000
+#define SBI_HSM_SUSP_PLAT_BASE			0x10000000
+
+#define SBI_HSM_SUSPEND_RET_DEFAULT		0x00000000
+#define SBI_HSM_SUSPEND_RET_PLATFORM		SBI_HSM_SUSP_PLAT_BASE
+#define SBI_HSM_SUSPEND_RET_LAST		SBI_HSM_SUSP_BASE_MASK
+#define SBI_HSM_SUSPEND_NON_RET_DEFAULT		SBI_HSM_SUSP_NON_RET_BIT
+#define SBI_HSM_SUSPEND_NON_RET_PLATFORM	(SBI_HSM_SUSP_NON_RET_BIT | \
+						 SBI_HSM_SUSP_PLAT_BASE)
+#define SBI_HSM_SUSPEND_NON_RET_LAST		(SBI_HSM_SUSP_NON_RET_BIT | \
+						 SBI_HSM_SUSP_BASE_MASK)
+
 enum sbi_ext_srst_fid {
 	SBI_EXT_SRST_RESET = 0,
 };
diff --git a/arch/riscv/kernel/cpu_ops_sbi.c b/arch/riscv/kernel/cpu_ops_sbi.c
index 685fae72b7f5..5fd90f03a3e9 100644
--- a/arch/riscv/kernel/cpu_ops_sbi.c
+++ b/arch/riscv/kernel/cpu_ops_sbi.c
@@ -97,7 +97,7 @@ static int sbi_cpu_is_stopped(unsigned int cpuid)
 
 	rc = sbi_hsm_hart_get_status(hartid);
 
-	if (rc == SBI_HSM_HART_STATUS_STOPPED)
+	if (rc == SBI_HSM_STATE_STOPPED)
 		return 0;
 	return rc;
 }
-- 
2.25.1


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

^ permalink raw reply	[flat|nested] 12+ messages in thread

* [RFC PATCH v3 5/8] cpuidle: Factor-out power domain related code from PSCI domain driver
  2021-03-18 13:05 [RFC PATCH v3 0/8] RISC-V CPU Idle Support Anup Patel
                   ` (3 preceding siblings ...)
  2021-03-18 13:05 ` [RFC PATCH v3 4/8] RISC-V: Add SBI HSM suspend related defines Anup Patel
@ 2021-03-18 13:05 ` Anup Patel
  2021-04-15 13:01   ` Ulf Hansson
  2021-03-18 13:05 ` [RFC PATCH v3 6/8] cpuidle: Add RISC-V SBI CPU idle driver Anup Patel
                   ` (2 subsequent siblings)
  7 siblings, 1 reply; 12+ messages in thread
From: Anup Patel @ 2021-03-18 13:05 UTC (permalink / raw)
  To: Palmer Dabbelt, Palmer Dabbelt, Paul Walmsley, Albert Ou,
	Daniel Lezcano, Ulf Hansson, Rafael J . Wysocki, Pavel Machek,
	Rob Herring
  Cc: Sandeep Tripathy, Atish Patra, Alistair Francis, Liush,
	Anup Patel, devicetree, linux-riscv, linux-kernel, linux-pm,
	linux-arm-kernel, Anup Patel

The generic power domain related code in PSCI domain driver is largely
independent of PSCI and can be shared with RISC-V SBI domain driver
hence we factor-out this code into dt_idle_genpd.c and dt_idle_genpd.h.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
---
 drivers/cpuidle/Kconfig                       |   4 +
 drivers/cpuidle/Kconfig.arm                   |   1 +
 drivers/cpuidle/Makefile                      |   1 +
 drivers/cpuidle/cpuidle-psci-domain.c         | 244 +-----------------
 drivers/cpuidle/cpuidle-psci.h                |  15 +-
 ...{cpuidle-psci-domain.c => dt_idle_genpd.c} | 165 ++++--------
 drivers/cpuidle/dt_idle_genpd.h               |  42 +++
 7 files changed, 121 insertions(+), 351 deletions(-)
 copy drivers/cpuidle/{cpuidle-psci-domain.c => dt_idle_genpd.c} (52%)
 create mode 100644 drivers/cpuidle/dt_idle_genpd.h

diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig
index c0aeedd66f02..f1afe7ab6b54 100644
--- a/drivers/cpuidle/Kconfig
+++ b/drivers/cpuidle/Kconfig
@@ -47,6 +47,10 @@ config CPU_IDLE_GOV_HALTPOLL
 config DT_IDLE_STATES
 	bool
 
+config DT_IDLE_GENPD
+	depends on PM_GENERIC_DOMAINS_OF
+	bool
+
 menu "ARM CPU Idle Drivers"
 depends on ARM || ARM64
 source "drivers/cpuidle/Kconfig.arm"
diff --git a/drivers/cpuidle/Kconfig.arm b/drivers/cpuidle/Kconfig.arm
index 0844fadc4be8..1007435ae298 100644
--- a/drivers/cpuidle/Kconfig.arm
+++ b/drivers/cpuidle/Kconfig.arm
@@ -27,6 +27,7 @@ config ARM_PSCI_CPUIDLE_DOMAIN
 	bool "PSCI CPU idle Domain"
 	depends on ARM_PSCI_CPUIDLE
 	depends on PM_GENERIC_DOMAINS_OF
+	select DT_IDLE_GENPD
 	default y
 	help
 	  Select this to enable the PSCI based CPUidle driver to use PM domains,
diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile
index 26bbc5e74123..11a26cef279f 100644
--- a/drivers/cpuidle/Makefile
+++ b/drivers/cpuidle/Makefile
@@ -6,6 +6,7 @@
 obj-y += cpuidle.o driver.o governor.o sysfs.o governors/
 obj-$(CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED) += coupled.o
 obj-$(CONFIG_DT_IDLE_STATES)		  += dt_idle_states.o
+obj-$(CONFIG_DT_IDLE_GENPD)		  += dt_idle_genpd.o
 obj-$(CONFIG_ARCH_HAS_CPU_RELAX)	  += poll_state.o
 obj-$(CONFIG_HALTPOLL_CPUIDLE)		  += cpuidle-haltpoll.o
 
diff --git a/drivers/cpuidle/cpuidle-psci-domain.c b/drivers/cpuidle/cpuidle-psci-domain.c
index ff2c3f8e4668..b0621d890ab7 100644
--- a/drivers/cpuidle/cpuidle-psci-domain.c
+++ b/drivers/cpuidle/cpuidle-psci-domain.c
@@ -16,17 +16,9 @@
 #include <linux/pm_domain.h>
 #include <linux/pm_runtime.h>
 #include <linux/psci.h>
-#include <linux/slab.h>
-#include <linux/string.h>
 
 #include "cpuidle-psci.h"
 
-struct psci_pd_provider {
-	struct list_head link;
-	struct device_node *node;
-};
-
-static LIST_HEAD(psci_pd_providers);
 static bool psci_pd_allow_domain_state;
 
 static int psci_pd_power_off(struct generic_pm_domain *pd)
@@ -47,178 +39,6 @@ static int psci_pd_power_off(struct generic_pm_domain *pd)
 	return 0;
 }
 
-static int psci_pd_parse_state_nodes(struct genpd_power_state *states,
-				     int state_count)
-{
-	int i, ret;
-	u32 psci_state, *psci_state_buf;
-
-	for (i = 0; i < state_count; i++) {
-		ret = psci_dt_parse_state_node(to_of_node(states[i].fwnode),
-					&psci_state);
-		if (ret)
-			goto free_state;
-
-		psci_state_buf = kmalloc(sizeof(u32), GFP_KERNEL);
-		if (!psci_state_buf) {
-			ret = -ENOMEM;
-			goto free_state;
-		}
-		*psci_state_buf = psci_state;
-		states[i].data = psci_state_buf;
-	}
-
-	return 0;
-
-free_state:
-	i--;
-	for (; i >= 0; i--)
-		kfree(states[i].data);
-	return ret;
-}
-
-static int psci_pd_parse_states(struct device_node *np,
-			struct genpd_power_state **states, int *state_count)
-{
-	int ret;
-
-	/* Parse the domain idle states. */
-	ret = of_genpd_parse_idle_states(np, states, state_count);
-	if (ret)
-		return ret;
-
-	/* Fill out the PSCI specifics for each found state. */
-	ret = psci_pd_parse_state_nodes(*states, *state_count);
-	if (ret)
-		kfree(*states);
-
-	return ret;
-}
-
-static void psci_pd_free_states(struct genpd_power_state *states,
-				unsigned int state_count)
-{
-	int i;
-
-	for (i = 0; i < state_count; i++)
-		kfree(states[i].data);
-	kfree(states);
-}
-
-static int psci_pd_init(struct device_node *np, bool use_osi)
-{
-	struct generic_pm_domain *pd;
-	struct psci_pd_provider *pd_provider;
-	struct dev_power_governor *pd_gov;
-	struct genpd_power_state *states = NULL;
-	int ret = -ENOMEM, state_count = 0;
-
-	pd = kzalloc(sizeof(*pd), GFP_KERNEL);
-	if (!pd)
-		goto out;
-
-	pd_provider = kzalloc(sizeof(*pd_provider), GFP_KERNEL);
-	if (!pd_provider)
-		goto free_pd;
-
-	pd->name = kasprintf(GFP_KERNEL, "%pOF", np);
-	if (!pd->name)
-		goto free_pd_prov;
-
-	/*
-	 * Parse the domain idle states and let genpd manage the state selection
-	 * for those being compatible with "domain-idle-state".
-	 */
-	ret = psci_pd_parse_states(np, &states, &state_count);
-	if (ret)
-		goto free_name;
-
-	pd->free_states = psci_pd_free_states;
-	pd->name = kbasename(pd->name);
-	pd->states = states;
-	pd->state_count = state_count;
-	pd->flags |= GENPD_FLAG_IRQ_SAFE | GENPD_FLAG_CPU_DOMAIN;
-
-	/* Allow power off when OSI has been successfully enabled. */
-	if (use_osi)
-		pd->power_off = psci_pd_power_off;
-	else
-		pd->flags |= GENPD_FLAG_ALWAYS_ON;
-
-	/* Use governor for CPU PM domains if it has some states to manage. */
-	pd_gov = state_count > 0 ? &pm_domain_cpu_gov : NULL;
-
-	ret = pm_genpd_init(pd, pd_gov, false);
-	if (ret) {
-		psci_pd_free_states(states, state_count);
-		goto free_name;
-	}
-
-	ret = of_genpd_add_provider_simple(np, pd);
-	if (ret)
-		goto remove_pd;
-
-	pd_provider->node = of_node_get(np);
-	list_add(&pd_provider->link, &psci_pd_providers);
-
-	pr_debug("init PM domain %s\n", pd->name);
-	return 0;
-
-remove_pd:
-	pm_genpd_remove(pd);
-free_name:
-	kfree(pd->name);
-free_pd_prov:
-	kfree(pd_provider);
-free_pd:
-	kfree(pd);
-out:
-	pr_err("failed to init PM domain ret=%d %pOF\n", ret, np);
-	return ret;
-}
-
-static void psci_pd_remove(void)
-{
-	struct psci_pd_provider *pd_provider, *it;
-	struct generic_pm_domain *genpd;
-
-	list_for_each_entry_safe(pd_provider, it, &psci_pd_providers, link) {
-		of_genpd_del_provider(pd_provider->node);
-
-		genpd = of_genpd_remove_last(pd_provider->node);
-		if (!IS_ERR(genpd))
-			kfree(genpd);
-
-		of_node_put(pd_provider->node);
-		list_del(&pd_provider->link);
-		kfree(pd_provider);
-	}
-}
-
-static int psci_pd_init_topology(struct device_node *np)
-{
-	struct device_node *node;
-	struct of_phandle_args child, parent;
-	int ret;
-
-	for_each_child_of_node(np, node) {
-		if (of_parse_phandle_with_args(node, "power-domains",
-					"#power-domain-cells", 0, &parent))
-			continue;
-
-		child.np = node;
-		child.args_count = 0;
-		ret = of_genpd_add_subdomain(&parent, &child);
-		of_node_put(parent.np);
-		if (ret) {
-			of_node_put(node);
-			return ret;
-		}
-	}
-
-	return 0;
-}
-
 static bool psci_pd_try_set_osi_mode(void)
 {
 	int ret;
@@ -244,6 +64,10 @@ static void psci_cpuidle_domain_sync_state(struct device *dev)
 	psci_pd_allow_domain_state = true;
 }
 
+static struct dt_idle_genpd_ops psci_genpd_ops = {
+	.parse_state_node = psci_dt_parse_state_node,
+};
+
 static const struct of_device_id psci_of_match[] = {
 	{ .compatible = "arm,psci-1.0" },
 	{}
@@ -252,48 +76,25 @@ static const struct of_device_id psci_of_match[] = {
 static int psci_cpuidle_domain_probe(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
-	struct device_node *node;
 	bool use_osi;
-	int ret = 0, pd_count = 0;
+	int ret = 0;
 
 	if (!np)
 		return -ENODEV;
 
 	/* If OSI mode is supported, let's try to enable it. */
 	use_osi = psci_pd_try_set_osi_mode();
+	if (use_osi)
+		psci_genpd_ops.power_off = psci_pd_power_off;
 
-	/*
-	 * Parse child nodes for the "#power-domain-cells" property and
-	 * initialize a genpd/genpd-of-provider pair when it's found.
-	 */
-	for_each_child_of_node(np, node) {
-		if (!of_find_property(node, "#power-domain-cells", NULL))
-			continue;
-
-		ret = psci_pd_init(node, use_osi);
-		if (ret)
-			goto put_node;
-
-		pd_count++;
-	}
-
-	/* Bail out if not using the hierarchical CPU topology. */
-	if (!pd_count)
-		goto no_pd;
-
-	/* Link genpd masters/subdomains to model the CPU topology. */
-	ret = psci_pd_init_topology(np);
+	/* Generic power domain probing based on DT node. */
+	ret = dt_idle_genpd_probe(&psci_genpd_ops, np);
 	if (ret)
-		goto remove_pd;
+		goto no_pd;
 
 	pr_info("Initialized CPU PM domain topology\n");
 	return 0;
 
-put_node:
-	of_node_put(node);
-remove_pd:
-	psci_pd_remove();
-	pr_err("failed to create CPU PM domains ret=%d\n", ret);
 no_pd:
 	if (use_osi)
 		psci_set_osi_mode(false);
@@ -314,28 +115,3 @@ static int __init psci_idle_init_domains(void)
 	return platform_driver_register(&psci_cpuidle_domain_driver);
 }
 subsys_initcall(psci_idle_init_domains);
-
-struct device *psci_dt_attach_cpu(int cpu)
-{
-	struct device *dev;
-
-	dev = dev_pm_domain_attach_by_name(get_cpu_device(cpu), "psci");
-	if (IS_ERR_OR_NULL(dev))
-		return dev;
-
-	pm_runtime_irq_safe(dev);
-	if (cpu_online(cpu))
-		pm_runtime_get_sync(dev);
-
-	dev_pm_syscore_device(dev, true);
-
-	return dev;
-}
-
-void psci_dt_detach_cpu(struct device *dev)
-{
-	if (IS_ERR_OR_NULL(dev))
-		return;
-
-	dev_pm_domain_detach(dev, false);
-}
diff --git a/drivers/cpuidle/cpuidle-psci.h b/drivers/cpuidle/cpuidle-psci.h
index d8e925e84c27..70de1e3c00af 100644
--- a/drivers/cpuidle/cpuidle-psci.h
+++ b/drivers/cpuidle/cpuidle-psci.h
@@ -10,8 +10,19 @@ void psci_set_domain_state(u32 state);
 int psci_dt_parse_state_node(struct device_node *np, u32 *state);
 
 #ifdef CONFIG_ARM_PSCI_CPUIDLE_DOMAIN
-struct device *psci_dt_attach_cpu(int cpu);
-void psci_dt_detach_cpu(struct device *dev);
+
+#include "dt_idle_genpd.h"
+
+static inline struct device *psci_dt_attach_cpu(int cpu)
+{
+	return dt_idle_genpd_attach_cpu(cpu, "psci");
+}
+
+static inline void psci_dt_detach_cpu(struct device *dev)
+{
+	dt_idle_genpd_detach_cpu(dev);
+}
+
 #else
 static inline struct device *psci_dt_attach_cpu(int cpu) { return NULL; }
 static inline void psci_dt_detach_cpu(struct device *dev) { }
diff --git a/drivers/cpuidle/cpuidle-psci-domain.c b/drivers/cpuidle/dt_idle_genpd.c
similarity index 52%
copy from drivers/cpuidle/cpuidle-psci-domain.c
copy to drivers/cpuidle/dt_idle_genpd.c
index ff2c3f8e4668..805c4c81d60f 100644
--- a/drivers/cpuidle/cpuidle-psci-domain.c
+++ b/drivers/cpuidle/dt_idle_genpd.c
@@ -1,71 +1,52 @@
-// SPDX-License-Identifier: GPL-2.0
+// SPDX-License-Identifier: GPL-2.0-only
 /*
- * PM domains for CPUs via genpd - managed by cpuidle-psci.
+ * PM domains for CPUs via genpd.
  *
  * Copyright (C) 2019 Linaro Ltd.
  * Author: Ulf Hansson <ulf.hansson@linaro.org>
  *
+ * Copyright (c) 2021 Western Digital Corporation or its affiliates.
  */
 
-#define pr_fmt(fmt) "CPUidle PSCI: " fmt
+#define pr_fmt(fmt) "dt-idle-genpd: " fmt
 
 #include <linux/cpu.h>
 #include <linux/device.h>
 #include <linux/kernel.h>
-#include <linux/platform_device.h>
 #include <linux/pm_domain.h>
 #include <linux/pm_runtime.h>
-#include <linux/psci.h>
 #include <linux/slab.h>
 #include <linux/string.h>
 
-#include "cpuidle-psci.h"
+#include "dt_idle_genpd.h"
 
-struct psci_pd_provider {
+struct dt_pd_provider {
 	struct list_head link;
 	struct device_node *node;
 };
 
-static LIST_HEAD(psci_pd_providers);
-static bool psci_pd_allow_domain_state;
+static LIST_HEAD(dt_pd_providers);
 
-static int psci_pd_power_off(struct generic_pm_domain *pd)
-{
-	struct genpd_power_state *state = &pd->states[pd->state_idx];
-	u32 *pd_state;
-
-	if (!state->data)
-		return 0;
-
-	if (!psci_pd_allow_domain_state)
-		return -EBUSY;
-
-	/* OSI mode is enabled, set the corresponding domain state. */
-	pd_state = state->data;
-	psci_set_domain_state(*pd_state);
-
-	return 0;
-}
-
-static int psci_pd_parse_state_nodes(struct genpd_power_state *states,
-				     int state_count)
+static int dt_pd_parse_state_nodes(const struct dt_idle_genpd_ops *ops,
+				   struct genpd_power_state *states,
+				   int state_count)
 {
 	int i, ret;
-	u32 psci_state, *psci_state_buf;
+	u32 state, *state_buf;
 
 	for (i = 0; i < state_count; i++) {
-		ret = psci_dt_parse_state_node(to_of_node(states[i].fwnode),
-					&psci_state);
+		ret = ops->parse_state_node(to_of_node(states[i].fwnode),
+					    &state);
 		if (ret)
 			goto free_state;
 
-		psci_state_buf = kmalloc(sizeof(u32), GFP_KERNEL);
-		if (!psci_state_buf) {
+		state_buf = kmalloc(sizeof(u32), GFP_KERNEL);
+		if (!state_buf) {
 			ret = -ENOMEM;
 			goto free_state;
 		}
-		*psci_state_buf = psci_state;
-		states[i].data = psci_state_buf;
+		*state_buf = state;
+		states[i].data = state_buf;
 	}
 
 	return 0;
@@ -77,8 +58,10 @@ static int psci_pd_parse_state_nodes(struct genpd_power_state *states,
 	return ret;
 }
 
-static int psci_pd_parse_states(struct device_node *np,
-			struct genpd_power_state **states, int *state_count)
+static int dt_pd_parse_states(const struct dt_idle_genpd_ops *ops,
+			      struct device_node *np,
+			      struct genpd_power_state **states,
+			      int *state_count)
 {
 	int ret;
 
@@ -87,15 +70,15 @@ static int psci_pd_parse_states(struct device_node *np,
 	if (ret)
 		return ret;
 
-	/* Fill out the PSCI specifics for each found state. */
-	ret = psci_pd_parse_state_nodes(*states, *state_count);
+	/* Fill out the dt specifics for each found state. */
+	ret = dt_pd_parse_state_nodes(ops, *states, *state_count);
 	if (ret)
 		kfree(*states);
 
 	return ret;
 }
 
-static void psci_pd_free_states(struct genpd_power_state *states,
+static void dt_pd_free_states(struct genpd_power_state *states,
 				unsigned int state_count)
 {
 	int i;
@@ -105,10 +88,11 @@ static void psci_pd_free_states(struct genpd_power_state *states,
 	kfree(states);
 }
 
-static int psci_pd_init(struct device_node *np, bool use_osi)
+static int dt_pd_init(const struct dt_idle_genpd_ops *ops,
+		      struct device_node *np)
 {
 	struct generic_pm_domain *pd;
-	struct psci_pd_provider *pd_provider;
+	struct dt_pd_provider *pd_provider;
 	struct dev_power_governor *pd_gov;
 	struct genpd_power_state *states = NULL;
 	int ret = -ENOMEM, state_count = 0;
@@ -129,19 +113,19 @@ static int psci_pd_init(struct device_node *np, bool use_osi)
 	 * Parse the domain idle states and let genpd manage the state selection
 	 * for those being compatible with "domain-idle-state".
 	 */
-	ret = psci_pd_parse_states(np, &states, &state_count);
+	ret = dt_pd_parse_states(ops, np, &states, &state_count);
 	if (ret)
 		goto free_name;
 
-	pd->free_states = psci_pd_free_states;
+	pd->free_states = dt_pd_free_states;
 	pd->name = kbasename(pd->name);
 	pd->states = states;
 	pd->state_count = state_count;
 	pd->flags |= GENPD_FLAG_IRQ_SAFE | GENPD_FLAG_CPU_DOMAIN;
 
-	/* Allow power off when OSI has been successfully enabled. */
-	if (use_osi)
-		pd->power_off = psci_pd_power_off;
+	/* Allow power off when available. */
+	if (ops->power_off)
+		pd->power_off = ops->power_off;
 	else
 		pd->flags |= GENPD_FLAG_ALWAYS_ON;
 
@@ -150,7 +134,7 @@ static int psci_pd_init(struct device_node *np, bool use_osi)
 
 	ret = pm_genpd_init(pd, pd_gov, false);
 	if (ret) {
-		psci_pd_free_states(states, state_count);
+		dt_pd_free_states(states, state_count);
 		goto free_name;
 	}
 
@@ -159,7 +143,7 @@ static int psci_pd_init(struct device_node *np, bool use_osi)
 		goto remove_pd;
 
 	pd_provider->node = of_node_get(np);
-	list_add(&pd_provider->link, &psci_pd_providers);
+	list_add(&pd_provider->link, &dt_pd_providers);
 
 	pr_debug("init PM domain %s\n", pd->name);
 	return 0;
@@ -177,12 +161,12 @@ static int psci_pd_init(struct device_node *np, bool use_osi)
 	return ret;
 }
 
-static void psci_pd_remove(void)
+static void dt_pd_remove(void)
 {
-	struct psci_pd_provider *pd_provider, *it;
+	struct dt_pd_provider *pd_provider, *it;
 	struct generic_pm_domain *genpd;
 
-	list_for_each_entry_safe(pd_provider, it, &psci_pd_providers, link) {
+	list_for_each_entry_safe(pd_provider, it, &dt_pd_providers, link) {
 		of_genpd_del_provider(pd_provider->node);
 
 		genpd = of_genpd_remove_last(pd_provider->node);
@@ -195,7 +179,7 @@ static void psci_pd_remove(void)
 	}
 }
 
-static int psci_pd_init_topology(struct device_node *np)
+static int dt_pd_init_topology(struct device_node *np)
 {
 	struct device_node *node;
 	struct of_phandle_args child, parent;
@@ -219,49 +203,15 @@ static int psci_pd_init_topology(struct device_node *np)
 	return 0;
 }
 
-static bool psci_pd_try_set_osi_mode(void)
-{
-	int ret;
-
-	if (!psci_has_osi_support())
-		return false;
-
-	ret = psci_set_osi_mode(true);
-	if (ret) {
-		pr_warn("failed to enable OSI mode: %d\n", ret);
-		return false;
-	}
-
-	return true;
-}
-
-static void psci_cpuidle_domain_sync_state(struct device *dev)
+int dt_idle_genpd_probe(const struct dt_idle_genpd_ops *ops,
+			struct device_node *np)
 {
-	/*
-	 * All devices have now been attached/probed to the PM domain topology,
-	 * hence it's fine to allow domain states to be picked.
-	 */
-	psci_pd_allow_domain_state = true;
-}
-
-static const struct of_device_id psci_of_match[] = {
-	{ .compatible = "arm,psci-1.0" },
-	{}
-};
-
-static int psci_cpuidle_domain_probe(struct platform_device *pdev)
-{
-	struct device_node *np = pdev->dev.of_node;
 	struct device_node *node;
-	bool use_osi;
 	int ret = 0, pd_count = 0;
 
-	if (!np)
+	if (!np || !ops || !ops->parse_state_node)
 		return -ENODEV;
 
-	/* If OSI mode is supported, let's try to enable it. */
-	use_osi = psci_pd_try_set_osi_mode();
-
 	/*
 	 * Parse child nodes for the "#power-domain-cells" property and
 	 * initialize a genpd/genpd-of-provider pair when it's found.
@@ -270,7 +220,7 @@ static int psci_cpuidle_domain_probe(struct platform_device *pdev)
 		if (!of_find_property(node, "#power-domain-cells", NULL))
 			continue;
 
-		ret = psci_pd_init(node, use_osi);
+		ret = dt_pd_init(ops, node);
 		if (ret)
 			goto put_node;
 
@@ -282,44 +232,27 @@ static int psci_cpuidle_domain_probe(struct platform_device *pdev)
 		goto no_pd;
 
 	/* Link genpd masters/subdomains to model the CPU topology. */
-	ret = psci_pd_init_topology(np);
+	ret = dt_pd_init_topology(np);
 	if (ret)
 		goto remove_pd;
 
-	pr_info("Initialized CPU PM domain topology\n");
 	return 0;
 
 put_node:
 	of_node_put(node);
 remove_pd:
-	psci_pd_remove();
+	dt_pd_remove();
 	pr_err("failed to create CPU PM domains ret=%d\n", ret);
 no_pd:
-	if (use_osi)
-		psci_set_osi_mode(false);
 	return ret;
 }
+EXPORT_SYMBOL_GPL(dt_idle_genpd_probe);
 
-static struct platform_driver psci_cpuidle_domain_driver = {
-	.probe  = psci_cpuidle_domain_probe,
-	.driver = {
-		.name = "psci-cpuidle-domain",
-		.of_match_table = psci_of_match,
-		.sync_state = psci_cpuidle_domain_sync_state,
-	},
-};
-
-static int __init psci_idle_init_domains(void)
-{
-	return platform_driver_register(&psci_cpuidle_domain_driver);
-}
-subsys_initcall(psci_idle_init_domains);
-
-struct device *psci_dt_attach_cpu(int cpu)
+struct device *dt_idle_genpd_attach_cpu(int cpu, const char *name)
 {
 	struct device *dev;
 
-	dev = dev_pm_domain_attach_by_name(get_cpu_device(cpu), "psci");
+	dev = dev_pm_domain_attach_by_name(get_cpu_device(cpu), name);
 	if (IS_ERR_OR_NULL(dev))
 		return dev;
 
@@ -331,11 +264,13 @@ struct device *psci_dt_attach_cpu(int cpu)
 
 	return dev;
 }
+EXPORT_SYMBOL_GPL(dt_idle_genpd_attach_cpu);
 
-void psci_dt_detach_cpu(struct device *dev)
+void dt_idle_genpd_detach_cpu(struct device *dev)
 {
 	if (IS_ERR_OR_NULL(dev))
 		return;
 
 	dev_pm_domain_detach(dev, false);
 }
+EXPORT_SYMBOL_GPL(dt_idle_genpd_detach_cpu);
diff --git a/drivers/cpuidle/dt_idle_genpd.h b/drivers/cpuidle/dt_idle_genpd.h
new file mode 100644
index 000000000000..a3d3d2e85871
--- /dev/null
+++ b/drivers/cpuidle/dt_idle_genpd.h
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __DT_IDLE_GENPD
+#define __DT_IDLE_GENPD
+
+struct device_node;
+struct generic_pm_domain;
+
+struct dt_idle_genpd_ops {
+	int (*parse_state_node)(struct device_node *np, u32 *state);
+	int (*power_off)(struct generic_pm_domain *pd);
+};
+
+#ifdef CONFIG_DT_IDLE_GENPD
+
+int dt_idle_genpd_probe(const struct dt_idle_genpd_ops *ops,
+			struct device_node *np);
+
+struct device *dt_idle_genpd_attach_cpu(int cpu, const char *name);
+
+void dt_idle_genpd_detach_cpu(struct device *dev);
+
+#else
+
+int dt_idle_genpd_probe(const struct dt_idle_genpd_ops *ops,
+			struct device_node *np)
+{
+	return 0;
+}
+
+static inline struct device *dt_idle_genpd_attach_cpu(int cpu,
+						      const char *name)
+{
+	return NULL;
+}
+
+static inline void dt_idle_genpd_detach_cpu(struct device *dev)
+{
+}
+
+#endif
+
+#endif
-- 
2.25.1


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

^ permalink raw reply	[flat|nested] 12+ messages in thread

* [RFC PATCH v3 6/8] cpuidle: Add RISC-V SBI CPU idle driver
  2021-03-18 13:05 [RFC PATCH v3 0/8] RISC-V CPU Idle Support Anup Patel
                   ` (4 preceding siblings ...)
  2021-03-18 13:05 ` [RFC PATCH v3 5/8] cpuidle: Factor-out power domain related code from PSCI domain driver Anup Patel
@ 2021-03-18 13:05 ` Anup Patel
  2021-03-18 13:05 ` [RFC PATCH v3 7/8] dt-bindings: Add common bindings for ARM and RISC-V idle states Anup Patel
  2021-03-18 13:05 ` [RFC PATCH v3 8/8] RISC-V: Enable RISC-V SBI CPU Idle driver for QEMU virt machine Anup Patel
  7 siblings, 0 replies; 12+ messages in thread
From: Anup Patel @ 2021-03-18 13:05 UTC (permalink / raw)
  To: Palmer Dabbelt, Palmer Dabbelt, Paul Walmsley, Albert Ou,
	Daniel Lezcano, Ulf Hansson, Rafael J . Wysocki, Pavel Machek,
	Rob Herring
  Cc: Sandeep Tripathy, Atish Patra, Alistair Francis, Liush,
	Anup Patel, devicetree, linux-riscv, linux-kernel, linux-pm,
	linux-arm-kernel, Anup Patel

The RISC-V SBI HSM extension provides HSM suspend call which can
be used by Linux RISC-V to enter platform specific low-power state.

This patch adds a CPU idle driver based on RISC-V SBI calls which
will populate idle states from device tree and use SBI calls to
entry these idle states.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
---
 MAINTAINERS                   |   8 +
 drivers/cpuidle/Kconfig       |   5 +
 drivers/cpuidle/Kconfig.riscv |  15 +
 drivers/cpuidle/Makefile      |   4 +
 drivers/cpuidle/cpuidle-sbi.c | 502 ++++++++++++++++++++++++++++++++++
 5 files changed, 534 insertions(+)
 create mode 100644 drivers/cpuidle/Kconfig.riscv
 create mode 100644 drivers/cpuidle/cpuidle-sbi.c

diff --git a/MAINTAINERS b/MAINTAINERS
index aa84121c5611..4954112efdb4 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4679,6 +4679,14 @@ S:	Supported
 F:	drivers/cpuidle/cpuidle-psci.h
 F:	drivers/cpuidle/cpuidle-psci-domain.c
 
+CPUIDLE DRIVER - RISC-V SBI
+M:	Anup Patel <anup.patel@wdc.com>
+R:	Sandeep Tripathy <milun.tripathy@gmail.com>
+L:	linux-pm@vger.kernel.org
+L:	linux-riscv@lists.infradead.org
+S:	Supported
+F:	drivers/cpuidle/cpuidle-sbi.c
+
 CRAMFS FILESYSTEM
 M:	Nicolas Pitre <nico@fluxnic.net>
 S:	Maintained
diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig
index f1afe7ab6b54..ff71dd662880 100644
--- a/drivers/cpuidle/Kconfig
+++ b/drivers/cpuidle/Kconfig
@@ -66,6 +66,11 @@ depends on PPC
 source "drivers/cpuidle/Kconfig.powerpc"
 endmenu
 
+menu "RISC-V CPU Idle Drivers"
+depends on RISCV
+source "drivers/cpuidle/Kconfig.riscv"
+endmenu
+
 config HALTPOLL_CPUIDLE
 	tristate "Halt poll cpuidle driver"
 	depends on X86 && KVM_GUEST
diff --git a/drivers/cpuidle/Kconfig.riscv b/drivers/cpuidle/Kconfig.riscv
new file mode 100644
index 000000000000..78518c26af74
--- /dev/null
+++ b/drivers/cpuidle/Kconfig.riscv
@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# RISC-V CPU Idle drivers
+#
+
+config RISCV_SBI_CPUIDLE
+	bool "RISC-V SBI CPU idle Driver"
+	depends on RISCV_SBI
+	select DT_IDLE_STATES
+	select CPU_IDLE_MULTIPLE_DRIVERS
+	select DT_IDLE_GENPD if PM_GENERIC_DOMAINS_OF
+	help
+	  Select this option to enable RISC-V SBI firmware based CPU idle
+	  driver for RISC-V systems. This drivers also supports hierarchical
+	  DT based layout of the idle state.
diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile
index 11a26cef279f..a36922c18510 100644
--- a/drivers/cpuidle/Makefile
+++ b/drivers/cpuidle/Makefile
@@ -35,3 +35,7 @@ obj-$(CONFIG_MIPS_CPS_CPUIDLE)		+= cpuidle-cps.o
 # POWERPC drivers
 obj-$(CONFIG_PSERIES_CPUIDLE)		+= cpuidle-pseries.o
 obj-$(CONFIG_POWERNV_CPUIDLE)		+= cpuidle-powernv.o
+
+###############################################################################
+# RISC-V drivers
+obj-$(CONFIG_RISCV_SBI_CPUIDLE)		+= cpuidle-sbi.o
diff --git a/drivers/cpuidle/cpuidle-sbi.c b/drivers/cpuidle/cpuidle-sbi.c
new file mode 100644
index 000000000000..47938fff61e1
--- /dev/null
+++ b/drivers/cpuidle/cpuidle-sbi.c
@@ -0,0 +1,502 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * RISC-V SBI CPU idle driver.
+ *
+ * Copyright (c) 2021 Western Digital Corporation or its affiliates.
+ */
+
+#define pr_fmt(fmt) "cpuidle-sbi: " fmt
+
+#include <linux/cpuidle.h>
+#include <linux/cpumask.h>
+#include <linux/cpu_pm.h>
+#include <linux/cpu_cooling.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <linux/pm_runtime.h>
+#include <asm/cpuidle.h>
+#include <asm/sbi.h>
+#include <asm/suspend.h>
+
+#include "dt_idle_states.h"
+#include "dt_idle_genpd.h"
+
+struct sbi_cpuidle_data {
+	u32 *states;
+	struct device *dev;
+};
+
+struct sbi_domain_state {
+	bool available;
+	u32 state;
+};
+
+static DEFINE_PER_CPU_READ_MOSTLY(struct sbi_cpuidle_data, sbi_cpuidle_data);
+static DEFINE_PER_CPU(struct sbi_domain_state, domain_state);
+static bool sbi_cpuidle_use_osi;
+static bool sbi_cpuidle_use_cpuhp;
+static bool sbi_cpuidle_pd_allow_domain_state;
+
+static inline void sbi_set_domain_state(u32 state)
+{
+	struct sbi_domain_state *data = this_cpu_ptr(&domain_state);
+
+	data->available = true;
+	data->state = state;
+}
+
+static inline u32 sbi_get_domain_state(void)
+{
+	struct sbi_domain_state *data = this_cpu_ptr(&domain_state);
+
+	return data->state;
+}
+
+static inline void sbi_clear_domain_state(void)
+{
+	struct sbi_domain_state *data = this_cpu_ptr(&domain_state);
+
+	data->available = false;
+}
+
+static inline bool sbi_is_domain_state_available(void)
+{
+	struct sbi_domain_state *data = this_cpu_ptr(&domain_state);
+
+	return data->available;
+}
+
+static int sbi_suspend_finisher(unsigned long suspend_type,
+				unsigned long resume_addr,
+				unsigned long opaque)
+{
+	struct sbiret ret;
+
+	ret = sbi_ecall(SBI_EXT_HSM, SBI_EXT_HSM_HART_SUSPEND,
+			suspend_type, resume_addr, opaque, 0, 0, 0);
+
+	return (ret.error) ? sbi_err_map_linux_errno(ret.error) : 0;
+}
+
+static int sbi_suspend(u32 state)
+{
+	if (state & SBI_HSM_SUSP_NON_RET_BIT)
+		return cpu_suspend(state, sbi_suspend_finisher);
+	else
+		return sbi_suspend_finisher(state, 0, 0);
+}
+
+static int sbi_cpuidle_enter_state(struct cpuidle_device *dev,
+				   struct cpuidle_driver *drv, int idx)
+{
+	u32 *states = __this_cpu_read(sbi_cpuidle_data.states);
+
+	return CPU_PM_CPU_IDLE_ENTER_PARAM(sbi_suspend, idx, states[idx]);
+}
+
+static int __sbi_enter_domain_idle_state(struct cpuidle_device *dev,
+					  struct cpuidle_driver *drv, int idx,
+					  bool s2idle)
+{
+	struct sbi_cpuidle_data *data = this_cpu_ptr(&sbi_cpuidle_data);
+	u32 *states = data->states;
+	struct device *pd_dev = data->dev;
+	u32 state;
+	int ret;
+
+	ret = cpu_pm_enter();
+	if (ret)
+		return -1;
+
+	/* Do runtime PM to manage a hierarchical CPU toplogy. */
+	rcu_irq_enter_irqson();
+	if (s2idle)
+		dev_pm_genpd_suspend(pd_dev);
+	else
+		pm_runtime_put_sync_suspend(pd_dev);
+	rcu_irq_exit_irqson();
+
+	if (sbi_is_domain_state_available())
+		state = sbi_get_domain_state();
+	else
+		state = states[idx];
+
+	ret = sbi_suspend(state) ? -1 : idx;
+
+	rcu_irq_enter_irqson();
+	if (s2idle)
+		dev_pm_genpd_resume(pd_dev);
+	else
+		pm_runtime_get_sync(pd_dev);
+	rcu_irq_exit_irqson();
+
+	cpu_pm_exit();
+
+	/* Clear the domain state to start fresh when back from idle. */
+	sbi_clear_domain_state();
+	return ret;
+}
+
+static int sbi_enter_domain_idle_state(struct cpuidle_device *dev,
+				       struct cpuidle_driver *drv, int idx)
+{
+	return __sbi_enter_domain_idle_state(dev, drv, idx, false);
+}
+
+static int sbi_enter_s2idle_domain_idle_state(struct cpuidle_device *dev,
+					      struct cpuidle_driver *drv,
+					      int idx)
+{
+	return __sbi_enter_domain_idle_state(dev, drv, idx, true);
+}
+
+static int sbi_cpuidle_cpuhp_up(unsigned int cpu)
+{
+	struct device *pd_dev = __this_cpu_read(sbi_cpuidle_data.dev);
+
+	if (pd_dev)
+		pm_runtime_get_sync(pd_dev);
+
+	return 0;
+}
+
+static int sbi_cpuidle_cpuhp_down(unsigned int cpu)
+{
+	struct device *pd_dev = __this_cpu_read(sbi_cpuidle_data.dev);
+
+	if (pd_dev) {
+		pm_runtime_put_sync(pd_dev);
+		/* Clear domain state to start fresh at next online. */
+		sbi_clear_domain_state();
+	}
+
+	return 0;
+}
+
+static void sbi_idle_init_cpuhp(void)
+{
+	int err;
+
+	if (!sbi_cpuidle_use_cpuhp)
+		return;
+
+	err = cpuhp_setup_state_nocalls(CPUHP_AP_CPU_PM_STARTING,
+					"cpuidle/sbi:online",
+					sbi_cpuidle_cpuhp_up,
+					sbi_cpuidle_cpuhp_down);
+	if (err)
+		pr_warn("Failed %d while setup cpuhp state\n", err);
+}
+
+static const struct of_device_id sbi_cpuidle_state_match[] = {
+	{ .compatible = "riscv,idle-state",
+	  .data = sbi_cpuidle_enter_state },
+	{ },
+};
+
+static bool sbi_suspend_state_is_valid(u32 state)
+{
+	if (state > SBI_HSM_SUSPEND_RET_DEFAULT &&
+	    state < SBI_HSM_SUSPEND_RET_PLATFORM)
+		return false;
+	if (state > SBI_HSM_SUSPEND_NON_RET_DEFAULT &&
+	    state < SBI_HSM_SUSPEND_NON_RET_PLATFORM)
+		return false;
+	return true;
+}
+
+static int sbi_dt_parse_state_node(struct device_node *np, u32 *state)
+{
+	int err = of_property_read_u32(np, "riscv,sbi-suspend-param", state);
+
+	if (err) {
+		pr_warn("%pOF missing riscv,sbi-suspend-param property\n", np);
+		return err;
+	}
+
+	if (!sbi_suspend_state_is_valid(*state)) {
+		pr_warn("Invalid SBI suspend state %#x\n", *state);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int sbi_dt_cpu_init_topology(struct cpuidle_driver *drv,
+				     struct sbi_cpuidle_data *data,
+				     unsigned int state_count, int cpu)
+{
+	/* Currently limit the hierarchical topology to be used in OSI mode. */
+	if (!sbi_cpuidle_use_osi)
+		return 0;
+
+	data->dev = dt_idle_genpd_attach_cpu(cpu, "sbi");
+	if (IS_ERR_OR_NULL(data->dev))
+		return PTR_ERR_OR_ZERO(data->dev);
+
+	/*
+	 * Using the deepest state for the CPU to trigger a potential selection
+	 * of a shared state for the domain, assumes the domain states are all
+	 * deeper states.
+	 */
+	drv->states[state_count - 1].enter = sbi_enter_domain_idle_state;
+	drv->states[state_count - 1].enter_s2idle = sbi_enter_s2idle_domain_idle_state;
+	sbi_cpuidle_use_cpuhp = true;
+
+	return 0;
+}
+
+static int sbi_cpuidle_dt_init_states(struct device *dev,
+					struct cpuidle_driver *drv,
+					unsigned int cpu,
+					unsigned int state_count)
+{
+	struct sbi_cpuidle_data *data = per_cpu_ptr(&sbi_cpuidle_data, cpu);
+	struct device_node *state_node;
+	struct device_node *cpu_node;
+	u32 *states;
+	int i, ret;
+
+	cpu_node = of_cpu_device_node_get(cpu);
+	if (!cpu_node)
+		return -ENODEV;
+
+	states = devm_kcalloc(dev, state_count, sizeof(*states), GFP_KERNEL);
+	if (!states) {
+		ret = -ENOMEM;
+		goto fail;
+	}
+
+	/* Parse SBI specific details from state DT nodes */
+	for (i = 1; i < state_count; i++) {
+		state_node = of_get_cpu_state_node(cpu_node, i - 1);
+		if (!state_node)
+			break;
+
+		ret = sbi_dt_parse_state_node(state_node, &states[i]);
+		of_node_put(state_node);
+
+		if (ret)
+			return ret;
+
+		pr_debug("sbi-state %#x index %d\n", states[i], i);
+	}
+	if (i != state_count) {
+		ret = -ENODEV;
+		goto fail;
+	}
+
+	/* Initialize optional data, used for the hierarchical topology. */
+	ret = sbi_dt_cpu_init_topology(drv, data, state_count, cpu);
+	if (ret < 0)
+		return ret;
+
+	/* Store states in the per-cpu struct. */
+	data->states = states;
+
+fail:
+	of_node_put(cpu_node);
+
+	return ret;
+}
+
+static void sbi_cpuidle_deinit_cpu(int cpu)
+{
+	struct sbi_cpuidle_data *data = per_cpu_ptr(&sbi_cpuidle_data, cpu);
+
+	dt_idle_genpd_detach_cpu(data->dev);
+	sbi_cpuidle_use_cpuhp = false;
+}
+
+static int sbi_cpuidle_init_cpu(struct device *dev, int cpu)
+{
+	struct cpuidle_driver *drv;
+	unsigned int state_count = 0;
+	int ret = 0;
+
+	drv = devm_kzalloc(dev, sizeof(*drv), GFP_KERNEL);
+	if (!drv)
+		return -ENOMEM;
+
+	drv->name = "sbi_cpuidle";
+	drv->owner = THIS_MODULE;
+	drv->cpumask = (struct cpumask *)cpumask_of(cpu);
+
+	/* RISC-V architectural WFI to be represented as state index 0. */
+	drv->states[0].enter = sbi_cpuidle_enter_state;
+	drv->states[0].exit_latency = 1;
+	drv->states[0].target_residency = 1;
+	drv->states[0].power_usage = UINT_MAX;
+	strcpy(drv->states[0].name, "WFI");
+	strcpy(drv->states[0].desc, "RISC-V WFI");
+
+	/*
+	 * If no DT idle states are detected (ret == 0) let the driver
+	 * initialization fail accordingly since there is no reason to
+	 * initialize the idle driver if only wfi is supported, the
+	 * default archictectural back-end already executes wfi
+	 * on idle entry.
+	 */
+	ret = dt_init_idle_driver(drv, sbi_cpuidle_state_match, 1);
+	if (ret <= 0) {
+		pr_debug("HART%ld: failed to parse DT idle states\n",
+			 cpuid_to_hartid_map(cpu));
+		return ret ? : -ENODEV;
+	}
+	state_count = ret + 1; /* Include WFI state as well */
+
+	/* Initialize idle states from DT. */
+	ret = sbi_cpuidle_dt_init_states(dev, drv, cpu, state_count);
+	if (ret) {
+		pr_err("HART%ld: failed to init idle states\n",
+		       cpuid_to_hartid_map(cpu));
+		return ret;
+	}
+
+	ret = cpuidle_register(drv, NULL);
+	if (ret)
+		goto deinit;
+
+	cpuidle_cooling_register(drv);
+
+	return 0;
+deinit:
+	sbi_cpuidle_deinit_cpu(cpu);
+	return ret;
+}
+
+static int sbi_cpuidle_pd_power_off(struct generic_pm_domain *pd)
+{
+	struct genpd_power_state *state = &pd->states[pd->state_idx];
+	u32 *pd_state;
+
+	if (!state->data)
+		return 0;
+
+	if (!sbi_cpuidle_pd_allow_domain_state)
+		return -EBUSY;
+
+	/* OSI mode is enabled, set the corresponding domain state. */
+	pd_state = state->data;
+	sbi_set_domain_state(*pd_state);
+
+	return 0;
+}
+
+static void sbi_cpuidle_domain_sync_state(struct device *dev)
+{
+	/*
+	 * All devices have now been attached/probed to the PM domain
+	 * topology, hence it's fine to allow domain states to be picked.
+	 */
+	sbi_cpuidle_pd_allow_domain_state = true;
+}
+
+static struct dt_idle_genpd_ops sbi_genpd_ops = {
+	.parse_state_node = sbi_dt_parse_state_node,
+};
+
+static int sbi_cpuidle_probe(struct platform_device *pdev)
+{
+	int cpu, ret;
+	struct cpuidle_driver *drv;
+	struct cpuidle_device *dev;
+	struct device_node *np, *pds_node;
+
+	/* Detect OSI support based on CPU DT nodes */
+	sbi_cpuidle_use_osi = true;
+	for_each_possible_cpu(cpu) {
+		np = of_cpu_device_node_get(cpu);
+		if (np &&
+		    of_find_property(np, "power-domains", NULL) &&
+		    of_find_property(np, "power-domain-names", NULL)) {
+			continue;
+		} else {
+			sbi_cpuidle_use_osi = false;
+			break;
+		}
+	}
+
+	if (sbi_cpuidle_use_osi)
+		sbi_genpd_ops.power_off = sbi_cpuidle_pd_power_off;
+
+	/* Populate generic power domains from DT nodes */
+	pds_node = of_find_node_by_path("/cpus/power-domains");
+	if (pds_node) {
+		ret = dt_idle_genpd_probe(&sbi_genpd_ops, pds_node);
+		of_node_put(pds_node);
+		if (ret)
+			return ret;
+	}
+
+	/* Initialize CPU idle driver for each CPU */
+	for_each_possible_cpu(cpu) {
+		ret = sbi_cpuidle_init_cpu(&pdev->dev, cpu);
+		if (ret) {
+			pr_debug("HART%ld: idle driver init failed\n",
+				 cpuid_to_hartid_map(cpu));
+			goto out_fail;
+		}
+	}
+
+	/* Setup CPU hotplut notifiers */
+	sbi_idle_init_cpuhp();
+
+	pr_info("idle driver registered for all CPUs\n");
+
+	return 0;
+
+out_fail:
+	while (--cpu >= 0) {
+		dev = per_cpu(cpuidle_devices, cpu);
+		drv = cpuidle_get_cpu_driver(dev);
+		cpuidle_unregister(drv);
+		sbi_cpuidle_deinit_cpu(cpu);
+	}
+
+	return ret;
+}
+
+static struct platform_driver sbi_cpuidle_driver = {
+	.probe = sbi_cpuidle_probe,
+	.driver = {
+		.name = "sbi-cpuidle",
+		.sync_state = sbi_cpuidle_domain_sync_state,
+	},
+};
+
+static int __init sbi_cpuidle_init(void)
+{
+	int ret;
+	struct platform_device *pdev;
+
+	/*
+	 * The SBI HSM suspend function is only available when:
+	 * 1) SBI version is 0.3 or higher
+	 * 2) SBI HSM extension is available
+	 */
+	if ((sbi_spec_version < sbi_mk_version(0, 3)) ||
+	    sbi_probe_extension(SBI_EXT_HSM) <= 0) {
+		pr_info("HSM suspend not available\n");
+		return 0;
+	}
+
+	ret = platform_driver_register(&sbi_cpuidle_driver);
+	if (ret)
+		return ret;
+
+	pdev = platform_device_register_simple("sbi-cpuidle",
+						-1, NULL, 0);
+	if (IS_ERR(pdev)) {
+		platform_driver_unregister(&sbi_cpuidle_driver);
+		return PTR_ERR(pdev);
+	}
+
+	return 0;
+}
+device_initcall(sbi_cpuidle_init);
-- 
2.25.1


_______________________________________________
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^ permalink raw reply	[flat|nested] 12+ messages in thread

* [RFC PATCH v3 7/8] dt-bindings: Add common bindings for ARM and RISC-V idle states
  2021-03-18 13:05 [RFC PATCH v3 0/8] RISC-V CPU Idle Support Anup Patel
                   ` (5 preceding siblings ...)
  2021-03-18 13:05 ` [RFC PATCH v3 6/8] cpuidle: Add RISC-V SBI CPU idle driver Anup Patel
@ 2021-03-18 13:05 ` Anup Patel
  2021-03-26  1:05   ` Rob Herring
  2021-03-18 13:05 ` [RFC PATCH v3 8/8] RISC-V: Enable RISC-V SBI CPU Idle driver for QEMU virt machine Anup Patel
  7 siblings, 1 reply; 12+ messages in thread
From: Anup Patel @ 2021-03-18 13:05 UTC (permalink / raw)
  To: Palmer Dabbelt, Palmer Dabbelt, Paul Walmsley, Albert Ou,
	Daniel Lezcano, Ulf Hansson, Rafael J . Wysocki, Pavel Machek,
	Rob Herring
  Cc: Sandeep Tripathy, Atish Patra, Alistair Francis, Liush,
	Anup Patel, devicetree, linux-riscv, linux-kernel, linux-pm,
	linux-arm-kernel, Anup Patel

The RISC-V CPU idle states will be described in under the
/cpus/idle-states DT node in the same way as ARM CPU idle
states.

This patch adds common bindings documentation for both ARM
and RISC-V idle states.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
---
 .../bindings/{arm => cpu}/idle-states.yaml    | 228 ++++++++++++++++--
 .../devicetree/bindings/riscv/cpus.yaml       |   6 +
 2 files changed, 217 insertions(+), 17 deletions(-)
 rename Documentation/devicetree/bindings/{arm => cpu}/idle-states.yaml (74%)

diff --git a/Documentation/devicetree/bindings/arm/idle-states.yaml b/Documentation/devicetree/bindings/cpu/idle-states.yaml
similarity index 74%
rename from Documentation/devicetree/bindings/arm/idle-states.yaml
rename to Documentation/devicetree/bindings/cpu/idle-states.yaml
index 52bce5dbb11f..74466f160cb2 100644
--- a/Documentation/devicetree/bindings/arm/idle-states.yaml
+++ b/Documentation/devicetree/bindings/cpu/idle-states.yaml
@@ -1,25 +1,30 @@
 # SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
 %YAML 1.2
 ---
-$id: http://devicetree.org/schemas/arm/idle-states.yaml#
+$id: http://devicetree.org/schemas/cpu/idle-states.yaml#
 $schema: http://devicetree.org/meta-schemas/core.yaml#
 
-title: ARM idle states binding description
+title: Idle states binding description
 
 maintainers:
   - Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
+  - Anup Patel <anup.patel@wdc.com>
 
 description: |+
   ==========================================
   1 - Introduction
   ==========================================
 
-  ARM systems contain HW capable of managing power consumption dynamically,
-  where cores can be put in different low-power states (ranging from simple wfi
-  to power gating) according to OS PM policies. The CPU states representing the
-  range of dynamic idle states that a processor can enter at run-time, can be
-  specified through device tree bindings representing the parameters required to
-  enter/exit specific idle states on a given processor.
+  ARM and RISC-V systems contain HW capable of managing power consumption
+  dynamically, where cores can be put in different low-power states (ranging
+  from simple wfi to power gating) according to OS PM policies. The CPU states
+  representing the range of dynamic idle states that a processor can enter at
+  run-time, can be specified through device tree bindings representing the
+  parameters required to enter/exit specific idle states on a given processor.
+
+  ==========================================
+  2 - ARM idle states
+  ==========================================
 
   According to the Server Base System Architecture document (SBSA, [3]), the
   power states an ARM CPU can be put into are identified by the following list:
@@ -43,8 +48,23 @@ description: |+
   The device tree binding definition for ARM idle states is the subject of this
   document.
 
+  ==========================================
+  3 - RISC-V idle states
+  ==========================================
+
+  On RISC-V systems, the HARTs (or CPUs) [6] can be put in platform specific
+  suspend (or idle) states (ranging from simple WFI, power gating, etc). The
+  RISC-V SBI v0.3 (or higher) [7] hart state management extension provides a
+  standard mechanism for OS to request HART state transitions.
+
+  The platform specific suspend (or idle) states of a hart can be either
+  retentive or non-rententive in nature. A retentive suspend state will
+  preserve HART registers and CSR values for all privilege modes whereas
+  a non-retentive suspend state will not preserve HART registers and CSR
+  values.
+
   ===========================================
-  2 - idle-states definitions
+  4 - idle-states definitions
   ===========================================
 
   Idle states are characterized for a specific system through a set of
@@ -211,10 +231,10 @@ description: |+
   properties specification that is the subject of the following sections.
 
   ===========================================
-  3 - idle-states node
+  5 - idle-states node
   ===========================================
 
-  ARM processor idle states are defined within the idle-states node, which is
+  The processor idle states are defined within the idle-states node, which is
   a direct child of the cpus node [1] and provides a container where the
   processor idle states, defined as device tree nodes, are listed.
 
@@ -223,7 +243,7 @@ description: |+
   just supports idle_standby, an idle-states node is not required.
 
   ===========================================
-  4 - References
+  6 - References
   ===========================================
 
   [1] ARM Linux Kernel documentation - CPUs bindings
@@ -238,9 +258,15 @@ description: |+
   [4] ARM Architecture Reference Manuals
       http://infocenter.arm.com/help/index.jsp
 
-  [6] ARM Linux Kernel documentation - Booting AArch64 Linux
+  [5] ARM Linux Kernel documentation - Booting AArch64 Linux
       Documentation/arm64/booting.rst
 
+  [6] RISC-V Linux Kernel documentation - CPUs bindings
+      Documentation/devicetree/bindings/riscv/cpus.yaml
+
+  [7] RISC-V Supervisor Binary Interface (SBI)
+      http://github.com/riscv/riscv-sbi-doc/riscv-sbi.adoc
+
 properties:
   $nodename:
     const: idle-states
@@ -253,7 +279,7 @@ properties:
       On ARM 32-bit systems this property is optional
 
       This assumes that the "enable-method" property is set to "psci" in the cpu
-      node[6] that is responsible for setting up CPU idle management in the OS
+      node[5] that is responsible for setting up CPU idle management in the OS
       implementation.
     const: psci
 
@@ -265,8 +291,8 @@ patternProperties:
       as follows.
 
       The idle state entered by executing the wfi instruction (idle_standby
-      SBSA,[3][4]) is considered standard on all ARM platforms and therefore
-      must not be listed.
+      SBSA,[3][4]) is considered standard on all ARM and RISC-V platforms and
+      therefore must not be listed.
 
       In addition to the properties listed above, a state node may require
       additional properties specific to the entry-method defined in the
@@ -275,7 +301,27 @@ patternProperties:
 
     properties:
       compatible:
-        const: arm,idle-state
+        oneOf:
+          - const: arm,idle-state
+          - const: riscv,idle-state
+
+      arm,psci-suspend-param:
+        $ref: /schemas/types.yaml#/definitions/uint32
+        description: |
+          power_state parameter to pass to the ARM PSCI suspend call.
+
+          Device tree nodes that require usage of PSCI CPU_SUSPEND function
+          (i.e. idle states node with entry-method property is set to "psci")
+          must specify this property.
+
+      riscv,sbi-suspend-param:
+        $ref: /schemas/types.yaml#/definitions/uint32
+        description: |
+          suspend_type parameter to pass to the RISC-V SBI HSM suspend call.
+
+          This property is required in idle state nodes of device tree meant
+          for RISC-V systems. For more details on the suspend_type parameter
+          refer the SBI specifiation v0.3 (or higher) [7].
 
       local-timer-stop:
         description:
@@ -317,6 +363,8 @@ patternProperties:
         description:
           A string used as a descriptive name for the idle state.
 
+    additionalProperties: false
+
     required:
       - compatible
       - entry-latency-us
@@ -658,4 +706,150 @@ examples:
         };
     };
 
+  - |
+    // Example 3 (RISC-V 64-bit, 4-cpu systems, two clusters):
+
+    cpus {
+        #size-cells = <0>;
+        #address-cells = <1>;
+
+        cpu@0 {
+            device_type = "cpu";
+            compatible = "riscv";
+            reg = <0x0>;
+            riscv,isa = "rv64imafdc";
+            mmu-type = "riscv,sv48";
+            cpu-idle-states = <&CPU_RET_0_0 &CPU_NONRET_0_0
+                            &CLUSTER_RET_0 &CLUSTER_NONRET_0>;
+
+            cpu_intc0: interrupt-controller {
+                #interrupt-cells = <1>;
+                compatible = "riscv,cpu-intc";
+                interrupt-controller;
+            };
+        };
+
+        cpu@1 {
+            device_type = "cpu";
+            compatible = "riscv";
+            reg = <0x1>;
+            riscv,isa = "rv64imafdc";
+            mmu-type = "riscv,sv48";
+            cpu-idle-states = <&CPU_RET_0_0 &CPU_NONRET_0_0
+                            &CLUSTER_RET_0 &CLUSTER_NONRET_0>;
+
+            cpu_intc1: interrupt-controller {
+                #interrupt-cells = <1>;
+                compatible = "riscv,cpu-intc";
+                interrupt-controller;
+            };
+        };
+
+        cpu@10 {
+            device_type = "cpu";
+            compatible = "riscv";
+            reg = <0x10>;
+            riscv,isa = "rv64imafdc";
+            mmu-type = "riscv,sv48";
+            cpu-idle-states = <&CPU_RET_1_0 &CPU_NONRET_1_0
+                            &CLUSTER_RET_1 &CLUSTER_NONRET_1>;
+
+            cpu_intc10: interrupt-controller {
+                #interrupt-cells = <1>;
+                compatible = "riscv,cpu-intc";
+                interrupt-controller;
+            };
+        };
+
+        cpu@11 {
+            device_type = "cpu";
+            compatible = "riscv";
+            reg = <0x11>;
+            riscv,isa = "rv64imafdc";
+            mmu-type = "riscv,sv48";
+            cpu-idle-states = <&CPU_RET_1_0 &CPU_NONRET_1_0
+                            &CLUSTER_RET_1 &CLUSTER_NONRET_1>;
+
+            cpu_intc11: interrupt-controller {
+                #interrupt-cells = <1>;
+                compatible = "riscv,cpu-intc";
+                interrupt-controller;
+            };
+        };
+
+        idle-states {
+            CPU_RET_0_0: cpu-retentive-0-0 {
+                compatible = "riscv,idle-state";
+                riscv,sbi-suspend-param = <0x10000000>;
+                entry-latency-us = <20>;
+                exit-latency-us = <40>;
+                min-residency-us = <80>;
+            };
+
+            CPU_NONRET_0_0: cpu-nonretentive-0-0 {
+                compatible = "riscv,idle-state";
+                riscv,sbi-suspend-param = <0x90000000>;
+                entry-latency-us = <250>;
+                exit-latency-us = <500>;
+                min-residency-us = <950>;
+            };
+
+            CLUSTER_RET_0: cluster-retentive-0 {
+                compatible = "riscv,idle-state";
+                riscv,sbi-suspend-param = <0x11000000>;
+                local-timer-stop;
+                entry-latency-us = <50>;
+                exit-latency-us = <100>;
+                min-residency-us = <250>;
+                wakeup-latency-us = <130>;
+            };
+
+            CLUSTER_NONRET_0: cluster-nonretentive-0 {
+                compatible = "riscv,idle-state";
+                riscv,sbi-suspend-param = <0x91000000>;
+                local-timer-stop;
+                entry-latency-us = <600>;
+                exit-latency-us = <1100>;
+                min-residency-us = <2700>;
+                wakeup-latency-us = <1500>;
+            };
+
+            CPU_RET_1_0: cpu-retentive-1-0 {
+                compatible = "riscv,idle-state";
+                riscv,sbi-suspend-param = <0x10000010>;
+                entry-latency-us = <20>;
+                exit-latency-us = <40>;
+                min-residency-us = <80>;
+            };
+
+            CPU_NONRET_1_0: cpu-nonretentive-1-0 {
+                compatible = "riscv,idle-state";
+                riscv,sbi-suspend-param = <0x90000010>;
+                entry-latency-us = <250>;
+                exit-latency-us = <500>;
+                min-residency-us = <950>;
+            };
+
+            CLUSTER_RET_1: cluster-retentive-1 {
+                compatible = "riscv,idle-state";
+                riscv,sbi-suspend-param = <0x11000010>;
+                local-timer-stop;
+                entry-latency-us = <50>;
+                exit-latency-us = <100>;
+                min-residency-us = <250>;
+                wakeup-latency-us = <130>;
+            };
+
+            CLUSTER_NONRET_1: cluster-nonretentive-1 {
+                compatible = "riscv,idle-state";
+                riscv,sbi-suspend-param = <0x91000010>;
+                local-timer-stop;
+                entry-latency-us = <600>;
+                exit-latency-us = <1100>;
+                min-residency-us = <2700>;
+                wakeup-latency-us = <1500>;
+            };
+        };
+    };
+
 ...
diff --git a/Documentation/devicetree/bindings/riscv/cpus.yaml b/Documentation/devicetree/bindings/riscv/cpus.yaml
index e534f6a7cfa1..482936630525 100644
--- a/Documentation/devicetree/bindings/riscv/cpus.yaml
+++ b/Documentation/devicetree/bindings/riscv/cpus.yaml
@@ -95,6 +95,12 @@ properties:
       - compatible
       - interrupt-controller
 
+  cpu-idle-states:
+    $ref: '/schemas/types.yaml#/definitions/phandle-array'
+    description: |
+      List of phandles to idle state nodes supported
+      by this hart (see ./idle-states.yaml).
+
 required:
   - riscv,isa
   - interrupt-controller
-- 
2.25.1


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^ permalink raw reply	[flat|nested] 12+ messages in thread

* [RFC PATCH v3 8/8] RISC-V: Enable RISC-V SBI CPU Idle driver for QEMU virt machine
  2021-03-18 13:05 [RFC PATCH v3 0/8] RISC-V CPU Idle Support Anup Patel
                   ` (6 preceding siblings ...)
  2021-03-18 13:05 ` [RFC PATCH v3 7/8] dt-bindings: Add common bindings for ARM and RISC-V idle states Anup Patel
@ 2021-03-18 13:05 ` Anup Patel
  7 siblings, 0 replies; 12+ messages in thread
From: Anup Patel @ 2021-03-18 13:05 UTC (permalink / raw)
  To: Palmer Dabbelt, Palmer Dabbelt, Paul Walmsley, Albert Ou,
	Daniel Lezcano, Ulf Hansson, Rafael J . Wysocki, Pavel Machek,
	Rob Herring
  Cc: Sandeep Tripathy, Atish Patra, Alistair Francis, Liush,
	Anup Patel, devicetree, linux-riscv, linux-kernel, linux-pm,
	linux-arm-kernel, Anup Patel

We enable RISC-V SBI CPU Idle driver for QEMU virt machine to test
SBI HSM Supend on QEMU.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
---
 arch/riscv/Kconfig.socs           | 3 +++
 arch/riscv/configs/defconfig      | 1 +
 arch/riscv/configs/rv32_defconfig | 1 +
 3 files changed, 5 insertions(+)

diff --git a/arch/riscv/Kconfig.socs b/arch/riscv/Kconfig.socs
index 7efcece8896c..efdf6fbe18dd 100644
--- a/arch/riscv/Kconfig.socs
+++ b/arch/riscv/Kconfig.socs
@@ -19,6 +19,9 @@ config SOC_VIRT
 	select GOLDFISH
 	select RTC_DRV_GOLDFISH if RTC_CLASS
 	select SIFIVE_PLIC
+	select PM_GENERIC_DOMAINS if PM
+	select PM_GENERIC_DOMAINS_OF if PM && OF
+	select RISCV_SBI_CPUIDLE if CPU_IDLE
 	help
 	  This enables support for QEMU Virt Machine.
 
diff --git a/arch/riscv/configs/defconfig b/arch/riscv/configs/defconfig
index dc4927c0e44b..aac26c20bbf5 100644
--- a/arch/riscv/configs/defconfig
+++ b/arch/riscv/configs/defconfig
@@ -19,6 +19,7 @@ CONFIG_SOC_SIFIVE=y
 CONFIG_SOC_VIRT=y
 CONFIG_SMP=y
 CONFIG_HOTPLUG_CPU=y
+CONFIG_PM=y
 CONFIG_CPU_IDLE=y
 CONFIG_JUMP_LABEL=y
 CONFIG_MODULES=y
diff --git a/arch/riscv/configs/rv32_defconfig b/arch/riscv/configs/rv32_defconfig
index 332e43a4a2c3..2285c95e34b3 100644
--- a/arch/riscv/configs/rv32_defconfig
+++ b/arch/riscv/configs/rv32_defconfig
@@ -20,6 +20,7 @@ CONFIG_SOC_VIRT=y
 CONFIG_ARCH_RV32I=y
 CONFIG_SMP=y
 CONFIG_HOTPLUG_CPU=y
+CONFIG_PM=y
 CONFIG_CPU_IDLE=y
 CONFIG_JUMP_LABEL=y
 CONFIG_MODULES=y
-- 
2.25.1


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^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [RFC PATCH v3 7/8] dt-bindings: Add common bindings for ARM and RISC-V idle states
  2021-03-18 13:05 ` [RFC PATCH v3 7/8] dt-bindings: Add common bindings for ARM and RISC-V idle states Anup Patel
@ 2021-03-26  1:05   ` Rob Herring
  0 siblings, 0 replies; 12+ messages in thread
From: Rob Herring @ 2021-03-26  1:05 UTC (permalink / raw)
  To: Anup Patel
  Cc: Rob Herring, linux-riscv, linux-arm-kernel, Palmer Dabbelt,
	Daniel Lezcano, Anup Patel, Rafael J . Wysocki, linux-pm,
	devicetree, Ulf Hansson, Paul Walmsley, Alistair Francis,
	Palmer Dabbelt, linux-kernel, Liush, Sandeep Tripathy,
	Pavel Machek, Albert Ou, Atish Patra

On Thu, 18 Mar 2021 18:35:11 +0530, Anup Patel wrote:
> The RISC-V CPU idle states will be described in under the
> /cpus/idle-states DT node in the same way as ARM CPU idle
> states.
> 
> This patch adds common bindings documentation for both ARM
> and RISC-V idle states.
> 
> Signed-off-by: Anup Patel <anup.patel@wdc.com>
> ---
>  .../bindings/{arm => cpu}/idle-states.yaml    | 228 ++++++++++++++++--
>  .../devicetree/bindings/riscv/cpus.yaml       |   6 +
>  2 files changed, 217 insertions(+), 17 deletions(-)
>  rename Documentation/devicetree/bindings/{arm => cpu}/idle-states.yaml (74%)
> 

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

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^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [RFC PATCH v3 5/8] cpuidle: Factor-out power domain related code from PSCI domain driver
  2021-03-18 13:05 ` [RFC PATCH v3 5/8] cpuidle: Factor-out power domain related code from PSCI domain driver Anup Patel
@ 2021-04-15 13:01   ` Ulf Hansson
  2021-05-09  4:49     ` Anup Patel
  0 siblings, 1 reply; 12+ messages in thread
From: Ulf Hansson @ 2021-04-15 13:01 UTC (permalink / raw)
  To: Anup Patel
  Cc: Palmer Dabbelt, Palmer Dabbelt, Paul Walmsley, Albert Ou,
	Daniel Lezcano, Rafael J . Wysocki, Pavel Machek, Rob Herring,
	Sandeep Tripathy, Atish Patra, Alistair Francis, Liush,
	Anup Patel, DTML, linux-riscv, Linux Kernel Mailing List,
	Linux PM, Linux ARM

Hi Anup,

First, my apologies for the very long delay.

On Thu, 18 Mar 2021 at 14:06, Anup Patel <anup.patel@wdc.com> wrote:
>
> The generic power domain related code in PSCI domain driver is largely
> independent of PSCI and can be shared with RISC-V SBI domain driver
> hence we factor-out this code into dt_idle_genpd.c and dt_idle_genpd.h.

I do agree that some parts could be considered as independent of PSCI,
perhaps those are rather "cpuidle-dt" specific.

Although, while I was looking at the changes in $subject patch, it
looks like you are adding another layer on top of
genpd/cpuidle-psci-domain. For example, you add the struct
dt_idle_genpd_ops with a couple of new callbacks. Even if this might
reduce open-coding a bit, I think it also introduces complexity. In my
opinion, those changes aren't really worth it.

Perhaps you can find some smaller pieces of code that are really
independent, which can be shared!?

>
> Signed-off-by: Anup Patel <anup.patel@wdc.com>

Kind regards
Uffe

> ---
>  drivers/cpuidle/Kconfig                       |   4 +
>  drivers/cpuidle/Kconfig.arm                   |   1 +
>  drivers/cpuidle/Makefile                      |   1 +
>  drivers/cpuidle/cpuidle-psci-domain.c         | 244 +-----------------
>  drivers/cpuidle/cpuidle-psci.h                |  15 +-
>  ...{cpuidle-psci-domain.c => dt_idle_genpd.c} | 165 ++++--------
>  drivers/cpuidle/dt_idle_genpd.h               |  42 +++
>  7 files changed, 121 insertions(+), 351 deletions(-)
>  copy drivers/cpuidle/{cpuidle-psci-domain.c => dt_idle_genpd.c} (52%)
>  create mode 100644 drivers/cpuidle/dt_idle_genpd.h
>
> diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig
> index c0aeedd66f02..f1afe7ab6b54 100644
> --- a/drivers/cpuidle/Kconfig
> +++ b/drivers/cpuidle/Kconfig
> @@ -47,6 +47,10 @@ config CPU_IDLE_GOV_HALTPOLL
>  config DT_IDLE_STATES
>         bool
>
> +config DT_IDLE_GENPD
> +       depends on PM_GENERIC_DOMAINS_OF
> +       bool
> +
>  menu "ARM CPU Idle Drivers"
>  depends on ARM || ARM64
>  source "drivers/cpuidle/Kconfig.arm"
> diff --git a/drivers/cpuidle/Kconfig.arm b/drivers/cpuidle/Kconfig.arm
> index 0844fadc4be8..1007435ae298 100644
> --- a/drivers/cpuidle/Kconfig.arm
> +++ b/drivers/cpuidle/Kconfig.arm
> @@ -27,6 +27,7 @@ config ARM_PSCI_CPUIDLE_DOMAIN
>         bool "PSCI CPU idle Domain"
>         depends on ARM_PSCI_CPUIDLE
>         depends on PM_GENERIC_DOMAINS_OF
> +       select DT_IDLE_GENPD
>         default y
>         help
>           Select this to enable the PSCI based CPUidle driver to use PM domains,
> diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile
> index 26bbc5e74123..11a26cef279f 100644
> --- a/drivers/cpuidle/Makefile
> +++ b/drivers/cpuidle/Makefile
> @@ -6,6 +6,7 @@
>  obj-y += cpuidle.o driver.o governor.o sysfs.o governors/
>  obj-$(CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED) += coupled.o
>  obj-$(CONFIG_DT_IDLE_STATES)             += dt_idle_states.o
> +obj-$(CONFIG_DT_IDLE_GENPD)              += dt_idle_genpd.o
>  obj-$(CONFIG_ARCH_HAS_CPU_RELAX)         += poll_state.o
>  obj-$(CONFIG_HALTPOLL_CPUIDLE)           += cpuidle-haltpoll.o
>
> diff --git a/drivers/cpuidle/cpuidle-psci-domain.c b/drivers/cpuidle/cpuidle-psci-domain.c
> index ff2c3f8e4668..b0621d890ab7 100644
> --- a/drivers/cpuidle/cpuidle-psci-domain.c
> +++ b/drivers/cpuidle/cpuidle-psci-domain.c
> @@ -16,17 +16,9 @@
>  #include <linux/pm_domain.h>
>  #include <linux/pm_runtime.h>
>  #include <linux/psci.h>
> -#include <linux/slab.h>
> -#include <linux/string.h>
>
>  #include "cpuidle-psci.h"
>
> -struct psci_pd_provider {
> -       struct list_head link;
> -       struct device_node *node;
> -};
> -
> -static LIST_HEAD(psci_pd_providers);
>  static bool psci_pd_allow_domain_state;
>
>  static int psci_pd_power_off(struct generic_pm_domain *pd)
> @@ -47,178 +39,6 @@ static int psci_pd_power_off(struct generic_pm_domain *pd)
>         return 0;
>  }
>
> -static int psci_pd_parse_state_nodes(struct genpd_power_state *states,
> -                                    int state_count)
> -{
> -       int i, ret;
> -       u32 psci_state, *psci_state_buf;
> -
> -       for (i = 0; i < state_count; i++) {
> -               ret = psci_dt_parse_state_node(to_of_node(states[i].fwnode),
> -                                       &psci_state);
> -               if (ret)
> -                       goto free_state;
> -
> -               psci_state_buf = kmalloc(sizeof(u32), GFP_KERNEL);
> -               if (!psci_state_buf) {
> -                       ret = -ENOMEM;
> -                       goto free_state;
> -               }
> -               *psci_state_buf = psci_state;
> -               states[i].data = psci_state_buf;
> -       }
> -
> -       return 0;
> -
> -free_state:
> -       i--;
> -       for (; i >= 0; i--)
> -               kfree(states[i].data);
> -       return ret;
> -}
> -
> -static int psci_pd_parse_states(struct device_node *np,
> -                       struct genpd_power_state **states, int *state_count)
> -{
> -       int ret;
> -
> -       /* Parse the domain idle states. */
> -       ret = of_genpd_parse_idle_states(np, states, state_count);
> -       if (ret)
> -               return ret;
> -
> -       /* Fill out the PSCI specifics for each found state. */
> -       ret = psci_pd_parse_state_nodes(*states, *state_count);
> -       if (ret)
> -               kfree(*states);
> -
> -       return ret;
> -}
> -
> -static void psci_pd_free_states(struct genpd_power_state *states,
> -                               unsigned int state_count)
> -{
> -       int i;
> -
> -       for (i = 0; i < state_count; i++)
> -               kfree(states[i].data);
> -       kfree(states);
> -}
> -
> -static int psci_pd_init(struct device_node *np, bool use_osi)
> -{
> -       struct generic_pm_domain *pd;
> -       struct psci_pd_provider *pd_provider;
> -       struct dev_power_governor *pd_gov;
> -       struct genpd_power_state *states = NULL;
> -       int ret = -ENOMEM, state_count = 0;
> -
> -       pd = kzalloc(sizeof(*pd), GFP_KERNEL);
> -       if (!pd)
> -               goto out;
> -
> -       pd_provider = kzalloc(sizeof(*pd_provider), GFP_KERNEL);
> -       if (!pd_provider)
> -               goto free_pd;
> -
> -       pd->name = kasprintf(GFP_KERNEL, "%pOF", np);
> -       if (!pd->name)
> -               goto free_pd_prov;
> -
> -       /*
> -        * Parse the domain idle states and let genpd manage the state selection
> -        * for those being compatible with "domain-idle-state".
> -        */
> -       ret = psci_pd_parse_states(np, &states, &state_count);
> -       if (ret)
> -               goto free_name;
> -
> -       pd->free_states = psci_pd_free_states;
> -       pd->name = kbasename(pd->name);
> -       pd->states = states;
> -       pd->state_count = state_count;
> -       pd->flags |= GENPD_FLAG_IRQ_SAFE | GENPD_FLAG_CPU_DOMAIN;
> -
> -       /* Allow power off when OSI has been successfully enabled. */
> -       if (use_osi)
> -               pd->power_off = psci_pd_power_off;
> -       else
> -               pd->flags |= GENPD_FLAG_ALWAYS_ON;
> -
> -       /* Use governor for CPU PM domains if it has some states to manage. */
> -       pd_gov = state_count > 0 ? &pm_domain_cpu_gov : NULL;
> -
> -       ret = pm_genpd_init(pd, pd_gov, false);
> -       if (ret) {
> -               psci_pd_free_states(states, state_count);
> -               goto free_name;
> -       }
> -
> -       ret = of_genpd_add_provider_simple(np, pd);
> -       if (ret)
> -               goto remove_pd;
> -
> -       pd_provider->node = of_node_get(np);
> -       list_add(&pd_provider->link, &psci_pd_providers);
> -
> -       pr_debug("init PM domain %s\n", pd->name);
> -       return 0;
> -
> -remove_pd:
> -       pm_genpd_remove(pd);
> -free_name:
> -       kfree(pd->name);
> -free_pd_prov:
> -       kfree(pd_provider);
> -free_pd:
> -       kfree(pd);
> -out:
> -       pr_err("failed to init PM domain ret=%d %pOF\n", ret, np);
> -       return ret;
> -}
> -
> -static void psci_pd_remove(void)
> -{
> -       struct psci_pd_provider *pd_provider, *it;
> -       struct generic_pm_domain *genpd;
> -
> -       list_for_each_entry_safe(pd_provider, it, &psci_pd_providers, link) {
> -               of_genpd_del_provider(pd_provider->node);
> -
> -               genpd = of_genpd_remove_last(pd_provider->node);
> -               if (!IS_ERR(genpd))
> -                       kfree(genpd);
> -
> -               of_node_put(pd_provider->node);
> -               list_del(&pd_provider->link);
> -               kfree(pd_provider);
> -       }
> -}
> -
> -static int psci_pd_init_topology(struct device_node *np)
> -{
> -       struct device_node *node;
> -       struct of_phandle_args child, parent;
> -       int ret;
> -
> -       for_each_child_of_node(np, node) {
> -               if (of_parse_phandle_with_args(node, "power-domains",
> -                                       "#power-domain-cells", 0, &parent))
> -                       continue;
> -
> -               child.np = node;
> -               child.args_count = 0;
> -               ret = of_genpd_add_subdomain(&parent, &child);
> -               of_node_put(parent.np);
> -               if (ret) {
> -                       of_node_put(node);
> -                       return ret;
> -               }
> -       }
> -
> -       return 0;
> -}
> -
>  static bool psci_pd_try_set_osi_mode(void)
>  {
>         int ret;
> @@ -244,6 +64,10 @@ static void psci_cpuidle_domain_sync_state(struct device *dev)
>         psci_pd_allow_domain_state = true;
>  }
>
> +static struct dt_idle_genpd_ops psci_genpd_ops = {
> +       .parse_state_node = psci_dt_parse_state_node,
> +};
> +
>  static const struct of_device_id psci_of_match[] = {
>         { .compatible = "arm,psci-1.0" },
>         {}
> @@ -252,48 +76,25 @@ static const struct of_device_id psci_of_match[] = {
>  static int psci_cpuidle_domain_probe(struct platform_device *pdev)
>  {
>         struct device_node *np = pdev->dev.of_node;
> -       struct device_node *node;
>         bool use_osi;
> -       int ret = 0, pd_count = 0;
> +       int ret = 0;
>
>         if (!np)
>                 return -ENODEV;
>
>         /* If OSI mode is supported, let's try to enable it. */
>         use_osi = psci_pd_try_set_osi_mode();
> +       if (use_osi)
> +               psci_genpd_ops.power_off = psci_pd_power_off;
>
> -       /*
> -        * Parse child nodes for the "#power-domain-cells" property and
> -        * initialize a genpd/genpd-of-provider pair when it's found.
> -        */
> -       for_each_child_of_node(np, node) {
> -               if (!of_find_property(node, "#power-domain-cells", NULL))
> -                       continue;
> -
> -               ret = psci_pd_init(node, use_osi);
> -               if (ret)
> -                       goto put_node;
> -
> -               pd_count++;
> -       }
> -
> -       /* Bail out if not using the hierarchical CPU topology. */
> -       if (!pd_count)
> -               goto no_pd;
> -
> -       /* Link genpd masters/subdomains to model the CPU topology. */
> -       ret = psci_pd_init_topology(np);
> +       /* Generic power domain probing based on DT node. */
> +       ret = dt_idle_genpd_probe(&psci_genpd_ops, np);
>         if (ret)
> -               goto remove_pd;
> +               goto no_pd;
>
>         pr_info("Initialized CPU PM domain topology\n");
>         return 0;
>
> -put_node:
> -       of_node_put(node);
> -remove_pd:
> -       psci_pd_remove();
> -       pr_err("failed to create CPU PM domains ret=%d\n", ret);
>  no_pd:
>         if (use_osi)
>                 psci_set_osi_mode(false);
> @@ -314,28 +115,3 @@ static int __init psci_idle_init_domains(void)
>         return platform_driver_register(&psci_cpuidle_domain_driver);
>  }
>  subsys_initcall(psci_idle_init_domains);
> -
> -struct device *psci_dt_attach_cpu(int cpu)
> -{
> -       struct device *dev;
> -
> -       dev = dev_pm_domain_attach_by_name(get_cpu_device(cpu), "psci");
> -       if (IS_ERR_OR_NULL(dev))
> -               return dev;
> -
> -       pm_runtime_irq_safe(dev);
> -       if (cpu_online(cpu))
> -               pm_runtime_get_sync(dev);
> -
> -       dev_pm_syscore_device(dev, true);
> -
> -       return dev;
> -}
> -
> -void psci_dt_detach_cpu(struct device *dev)
> -{
> -       if (IS_ERR_OR_NULL(dev))
> -               return;
> -
> -       dev_pm_domain_detach(dev, false);
> -}
> diff --git a/drivers/cpuidle/cpuidle-psci.h b/drivers/cpuidle/cpuidle-psci.h
> index d8e925e84c27..70de1e3c00af 100644
> --- a/drivers/cpuidle/cpuidle-psci.h
> +++ b/drivers/cpuidle/cpuidle-psci.h
> @@ -10,8 +10,19 @@ void psci_set_domain_state(u32 state);
>  int psci_dt_parse_state_node(struct device_node *np, u32 *state);
>
>  #ifdef CONFIG_ARM_PSCI_CPUIDLE_DOMAIN
> -struct device *psci_dt_attach_cpu(int cpu);
> -void psci_dt_detach_cpu(struct device *dev);
> +
> +#include "dt_idle_genpd.h"
> +
> +static inline struct device *psci_dt_attach_cpu(int cpu)
> +{
> +       return dt_idle_genpd_attach_cpu(cpu, "psci");
> +}
> +
> +static inline void psci_dt_detach_cpu(struct device *dev)
> +{
> +       dt_idle_genpd_detach_cpu(dev);
> +}
> +
>  #else
>  static inline struct device *psci_dt_attach_cpu(int cpu) { return NULL; }
>  static inline void psci_dt_detach_cpu(struct device *dev) { }
> diff --git a/drivers/cpuidle/cpuidle-psci-domain.c b/drivers/cpuidle/dt_idle_genpd.c
> similarity index 52%
> copy from drivers/cpuidle/cpuidle-psci-domain.c
> copy to drivers/cpuidle/dt_idle_genpd.c
> index ff2c3f8e4668..805c4c81d60f 100644
> --- a/drivers/cpuidle/cpuidle-psci-domain.c
> +++ b/drivers/cpuidle/dt_idle_genpd.c
> @@ -1,71 +1,52 @@
> -// SPDX-License-Identifier: GPL-2.0
> +// SPDX-License-Identifier: GPL-2.0-only
>  /*
> - * PM domains for CPUs via genpd - managed by cpuidle-psci.
> + * PM domains for CPUs via genpd.
>   *
>   * Copyright (C) 2019 Linaro Ltd.
>   * Author: Ulf Hansson <ulf.hansson@linaro.org>
>   *
> + * Copyright (c) 2021 Western Digital Corporation or its affiliates.
>   */
>
> -#define pr_fmt(fmt) "CPUidle PSCI: " fmt
> +#define pr_fmt(fmt) "dt-idle-genpd: " fmt
>
>  #include <linux/cpu.h>
>  #include <linux/device.h>
>  #include <linux/kernel.h>
> -#include <linux/platform_device.h>
>  #include <linux/pm_domain.h>
>  #include <linux/pm_runtime.h>
> -#include <linux/psci.h>
>  #include <linux/slab.h>
>  #include <linux/string.h>
>
> -#include "cpuidle-psci.h"
> +#include "dt_idle_genpd.h"
>
> -struct psci_pd_provider {
> +struct dt_pd_provider {
>         struct list_head link;
>         struct device_node *node;
>  };
>
> -static LIST_HEAD(psci_pd_providers);
> -static bool psci_pd_allow_domain_state;
> +static LIST_HEAD(dt_pd_providers);
>
> -static int psci_pd_power_off(struct generic_pm_domain *pd)
> -{
> -       struct genpd_power_state *state = &pd->states[pd->state_idx];
> -       u32 *pd_state;
> -
> -       if (!state->data)
> -               return 0;
> -
> -       if (!psci_pd_allow_domain_state)
> -               return -EBUSY;
> -
> -       /* OSI mode is enabled, set the corresponding domain state. */
> -       pd_state = state->data;
> -       psci_set_domain_state(*pd_state);
> -
> -       return 0;
> -}
> -
> -static int psci_pd_parse_state_nodes(struct genpd_power_state *states,
> -                                    int state_count)
> +static int dt_pd_parse_state_nodes(const struct dt_idle_genpd_ops *ops,
> +                                  struct genpd_power_state *states,
> +                                  int state_count)
>  {
>         int i, ret;
> -       u32 psci_state, *psci_state_buf;
> +       u32 state, *state_buf;
>
>         for (i = 0; i < state_count; i++) {
> -               ret = psci_dt_parse_state_node(to_of_node(states[i].fwnode),
> -                                       &psci_state);
> +               ret = ops->parse_state_node(to_of_node(states[i].fwnode),
> +                                           &state);
>                 if (ret)
>                         goto free_state;
>
> -               psci_state_buf = kmalloc(sizeof(u32), GFP_KERNEL);
> -               if (!psci_state_buf) {
> +               state_buf = kmalloc(sizeof(u32), GFP_KERNEL);
> +               if (!state_buf) {
>                         ret = -ENOMEM;
>                         goto free_state;
>                 }
> -               *psci_state_buf = psci_state;
> -               states[i].data = psci_state_buf;
> +               *state_buf = state;
> +               states[i].data = state_buf;
>         }
>
>         return 0;
> @@ -77,8 +58,10 @@ static int psci_pd_parse_state_nodes(struct genpd_power_state *states,
>         return ret;
>  }
>
> -static int psci_pd_parse_states(struct device_node *np,
> -                       struct genpd_power_state **states, int *state_count)
> +static int dt_pd_parse_states(const struct dt_idle_genpd_ops *ops,
> +                             struct device_node *np,
> +                             struct genpd_power_state **states,
> +                             int *state_count)
>  {
>         int ret;
>
> @@ -87,15 +70,15 @@ static int psci_pd_parse_states(struct device_node *np,
>         if (ret)
>                 return ret;
>
> -       /* Fill out the PSCI specifics for each found state. */
> -       ret = psci_pd_parse_state_nodes(*states, *state_count);
> +       /* Fill out the dt specifics for each found state. */
> +       ret = dt_pd_parse_state_nodes(ops, *states, *state_count);
>         if (ret)
>                 kfree(*states);
>
>         return ret;
>  }
>
> -static void psci_pd_free_states(struct genpd_power_state *states,
> +static void dt_pd_free_states(struct genpd_power_state *states,
>                                 unsigned int state_count)
>  {
>         int i;
> @@ -105,10 +88,11 @@ static void psci_pd_free_states(struct genpd_power_state *states,
>         kfree(states);
>  }
>
> -static int psci_pd_init(struct device_node *np, bool use_osi)
> +static int dt_pd_init(const struct dt_idle_genpd_ops *ops,
> +                     struct device_node *np)
>  {
>         struct generic_pm_domain *pd;
> -       struct psci_pd_provider *pd_provider;
> +       struct dt_pd_provider *pd_provider;
>         struct dev_power_governor *pd_gov;
>         struct genpd_power_state *states = NULL;
>         int ret = -ENOMEM, state_count = 0;
> @@ -129,19 +113,19 @@ static int psci_pd_init(struct device_node *np, bool use_osi)
>          * Parse the domain idle states and let genpd manage the state selection
>          * for those being compatible with "domain-idle-state".
>          */
> -       ret = psci_pd_parse_states(np, &states, &state_count);
> +       ret = dt_pd_parse_states(ops, np, &states, &state_count);
>         if (ret)
>                 goto free_name;
>
> -       pd->free_states = psci_pd_free_states;
> +       pd->free_states = dt_pd_free_states;
>         pd->name = kbasename(pd->name);
>         pd->states = states;
>         pd->state_count = state_count;
>         pd->flags |= GENPD_FLAG_IRQ_SAFE | GENPD_FLAG_CPU_DOMAIN;
>
> -       /* Allow power off when OSI has been successfully enabled. */
> -       if (use_osi)
> -               pd->power_off = psci_pd_power_off;
> +       /* Allow power off when available. */
> +       if (ops->power_off)
> +               pd->power_off = ops->power_off;
>         else
>                 pd->flags |= GENPD_FLAG_ALWAYS_ON;
>
> @@ -150,7 +134,7 @@ static int psci_pd_init(struct device_node *np, bool use_osi)
>
>         ret = pm_genpd_init(pd, pd_gov, false);
>         if (ret) {
> -               psci_pd_free_states(states, state_count);
> +               dt_pd_free_states(states, state_count);
>                 goto free_name;
>         }
>
> @@ -159,7 +143,7 @@ static int psci_pd_init(struct device_node *np, bool use_osi)
>                 goto remove_pd;
>
>         pd_provider->node = of_node_get(np);
> -       list_add(&pd_provider->link, &psci_pd_providers);
> +       list_add(&pd_provider->link, &dt_pd_providers);
>
>         pr_debug("init PM domain %s\n", pd->name);
>         return 0;
> @@ -177,12 +161,12 @@ static int psci_pd_init(struct device_node *np, bool use_osi)
>         return ret;
>  }
>
> -static void psci_pd_remove(void)
> +static void dt_pd_remove(void)
>  {
> -       struct psci_pd_provider *pd_provider, *it;
> +       struct dt_pd_provider *pd_provider, *it;
>         struct generic_pm_domain *genpd;
>
> -       list_for_each_entry_safe(pd_provider, it, &psci_pd_providers, link) {
> +       list_for_each_entry_safe(pd_provider, it, &dt_pd_providers, link) {
>                 of_genpd_del_provider(pd_provider->node);
>
>                 genpd = of_genpd_remove_last(pd_provider->node);
> @@ -195,7 +179,7 @@ static void psci_pd_remove(void)
>         }
>  }
>
> -static int psci_pd_init_topology(struct device_node *np)
> +static int dt_pd_init_topology(struct device_node *np)
>  {
>         struct device_node *node;
>         struct of_phandle_args child, parent;
> @@ -219,49 +203,15 @@ static int psci_pd_init_topology(struct device_node *np)
>         return 0;
>  }
>
> -static bool psci_pd_try_set_osi_mode(void)
> -{
> -       int ret;
> -
> -       if (!psci_has_osi_support())
> -               return false;
> -
> -       ret = psci_set_osi_mode(true);
> -       if (ret) {
> -               pr_warn("failed to enable OSI mode: %d\n", ret);
> -               return false;
> -       }
> -
> -       return true;
> -}
> -
> -static void psci_cpuidle_domain_sync_state(struct device *dev)
> +int dt_idle_genpd_probe(const struct dt_idle_genpd_ops *ops,
> +                       struct device_node *np)
>  {
> -       /*
> -        * All devices have now been attached/probed to the PM domain topology,
> -        * hence it's fine to allow domain states to be picked.
> -        */
> -       psci_pd_allow_domain_state = true;
> -}
> -
> -static const struct of_device_id psci_of_match[] = {
> -       { .compatible = "arm,psci-1.0" },
> -       {}
> -};
> -
> -static int psci_cpuidle_domain_probe(struct platform_device *pdev)
> -{
> -       struct device_node *np = pdev->dev.of_node;
>         struct device_node *node;
> -       bool use_osi;
>         int ret = 0, pd_count = 0;
>
> -       if (!np)
> +       if (!np || !ops || !ops->parse_state_node)
>                 return -ENODEV;
>
> -       /* If OSI mode is supported, let's try to enable it. */
> -       use_osi = psci_pd_try_set_osi_mode();
> -
>         /*
>          * Parse child nodes for the "#power-domain-cells" property and
>          * initialize a genpd/genpd-of-provider pair when it's found.
> @@ -270,7 +220,7 @@ static int psci_cpuidle_domain_probe(struct platform_device *pdev)
>                 if (!of_find_property(node, "#power-domain-cells", NULL))
>                         continue;
>
> -               ret = psci_pd_init(node, use_osi);
> +               ret = dt_pd_init(ops, node);
>                 if (ret)
>                         goto put_node;
>
> @@ -282,44 +232,27 @@ static int psci_cpuidle_domain_probe(struct platform_device *pdev)
>                 goto no_pd;
>
>         /* Link genpd masters/subdomains to model the CPU topology. */
> -       ret = psci_pd_init_topology(np);
> +       ret = dt_pd_init_topology(np);
>         if (ret)
>                 goto remove_pd;
>
> -       pr_info("Initialized CPU PM domain topology\n");
>         return 0;
>
>  put_node:
>         of_node_put(node);
>  remove_pd:
> -       psci_pd_remove();
> +       dt_pd_remove();
>         pr_err("failed to create CPU PM domains ret=%d\n", ret);
>  no_pd:
> -       if (use_osi)
> -               psci_set_osi_mode(false);
>         return ret;
>  }
> +EXPORT_SYMBOL_GPL(dt_idle_genpd_probe);
>
> -static struct platform_driver psci_cpuidle_domain_driver = {
> -       .probe  = psci_cpuidle_domain_probe,
> -       .driver = {
> -               .name = "psci-cpuidle-domain",
> -               .of_match_table = psci_of_match,
> -               .sync_state = psci_cpuidle_domain_sync_state,
> -       },
> -};
> -
> -static int __init psci_idle_init_domains(void)
> -{
> -       return platform_driver_register(&psci_cpuidle_domain_driver);
> -}
> -subsys_initcall(psci_idle_init_domains);
> -
> -struct device *psci_dt_attach_cpu(int cpu)
> +struct device *dt_idle_genpd_attach_cpu(int cpu, const char *name)
>  {
>         struct device *dev;
>
> -       dev = dev_pm_domain_attach_by_name(get_cpu_device(cpu), "psci");
> +       dev = dev_pm_domain_attach_by_name(get_cpu_device(cpu), name);
>         if (IS_ERR_OR_NULL(dev))
>                 return dev;
>
> @@ -331,11 +264,13 @@ struct device *psci_dt_attach_cpu(int cpu)
>
>         return dev;
>  }
> +EXPORT_SYMBOL_GPL(dt_idle_genpd_attach_cpu);
>
> -void psci_dt_detach_cpu(struct device *dev)
> +void dt_idle_genpd_detach_cpu(struct device *dev)
>  {
>         if (IS_ERR_OR_NULL(dev))
>                 return;
>
>         dev_pm_domain_detach(dev, false);
>  }
> +EXPORT_SYMBOL_GPL(dt_idle_genpd_detach_cpu);
> diff --git a/drivers/cpuidle/dt_idle_genpd.h b/drivers/cpuidle/dt_idle_genpd.h
> new file mode 100644
> index 000000000000..a3d3d2e85871
> --- /dev/null
> +++ b/drivers/cpuidle/dt_idle_genpd.h
> @@ -0,0 +1,42 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef __DT_IDLE_GENPD
> +#define __DT_IDLE_GENPD
> +
> +struct device_node;
> +struct generic_pm_domain;
> +
> +struct dt_idle_genpd_ops {
> +       int (*parse_state_node)(struct device_node *np, u32 *state);
> +       int (*power_off)(struct generic_pm_domain *pd);
> +};
> +
> +#ifdef CONFIG_DT_IDLE_GENPD
> +
> +int dt_idle_genpd_probe(const struct dt_idle_genpd_ops *ops,
> +                       struct device_node *np);
> +
> +struct device *dt_idle_genpd_attach_cpu(int cpu, const char *name);
> +
> +void dt_idle_genpd_detach_cpu(struct device *dev);
> +
> +#else
> +
> +int dt_idle_genpd_probe(const struct dt_idle_genpd_ops *ops,
> +                       struct device_node *np)
> +{
> +       return 0;
> +}
> +
> +static inline struct device *dt_idle_genpd_attach_cpu(int cpu,
> +                                                     const char *name)
> +{
> +       return NULL;
> +}
> +
> +static inline void dt_idle_genpd_detach_cpu(struct device *dev)
> +{
> +}
> +
> +#endif
> +
> +#endif
> --
> 2.25.1
>

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^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [RFC PATCH v3 5/8] cpuidle: Factor-out power domain related code from PSCI domain driver
  2021-04-15 13:01   ` Ulf Hansson
@ 2021-05-09  4:49     ` Anup Patel
  0 siblings, 0 replies; 12+ messages in thread
From: Anup Patel @ 2021-05-09  4:49 UTC (permalink / raw)
  To: Ulf Hansson
  Cc: Anup Patel, Palmer Dabbelt, Palmer Dabbelt, Paul Walmsley,
	Albert Ou, Daniel Lezcano, Rafael J . Wysocki, Pavel Machek,
	Rob Herring, Sandeep Tripathy, Atish Patra, Alistair Francis,
	Liush, DTML, linux-riscv, Linux Kernel Mailing List, Linux PM,
	Linux ARM

On Thu, Apr 15, 2021 at 6:32 PM Ulf Hansson <ulf.hansson@linaro.org> wrote:
>
> Hi Anup,
>
> First, my apologies for the very long delay.
>
> On Thu, 18 Mar 2021 at 14:06, Anup Patel <anup.patel@wdc.com> wrote:
> >
> > The generic power domain related code in PSCI domain driver is largely
> > independent of PSCI and can be shared with RISC-V SBI domain driver
> > hence we factor-out this code into dt_idle_genpd.c and dt_idle_genpd.h.
>
> I do agree that some parts could be considered as independent of PSCI,
> perhaps those are rather "cpuidle-dt" specific.
>
> Although, while I was looking at the changes in $subject patch, it
> looks like you are adding another layer on top of
> genpd/cpuidle-psci-domain. For example, you add the struct
> dt_idle_genpd_ops with a couple of new callbacks. Even if this might
> reduce open-coding a bit, I think it also introduces complexity. In my
> opinion, those changes aren't really worth it.
>
> Perhaps you can find some smaller pieces of code that are really
> independent, which can be shared!?

Sure, let me try to simplify code sharing with PSCI.

My apologies for the slow response, I got busy with other task.

Regards,
Anup

>
> >
> > Signed-off-by: Anup Patel <anup.patel@wdc.com>
>
> Kind regards
> Uffe
>
> > ---
> >  drivers/cpuidle/Kconfig                       |   4 +
> >  drivers/cpuidle/Kconfig.arm                   |   1 +
> >  drivers/cpuidle/Makefile                      |   1 +
> >  drivers/cpuidle/cpuidle-psci-domain.c         | 244 +-----------------
> >  drivers/cpuidle/cpuidle-psci.h                |  15 +-
> >  ...{cpuidle-psci-domain.c => dt_idle_genpd.c} | 165 ++++--------
> >  drivers/cpuidle/dt_idle_genpd.h               |  42 +++
> >  7 files changed, 121 insertions(+), 351 deletions(-)
> >  copy drivers/cpuidle/{cpuidle-psci-domain.c => dt_idle_genpd.c} (52%)
> >  create mode 100644 drivers/cpuidle/dt_idle_genpd.h
> >
> > diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig
> > index c0aeedd66f02..f1afe7ab6b54 100644
> > --- a/drivers/cpuidle/Kconfig
> > +++ b/drivers/cpuidle/Kconfig
> > @@ -47,6 +47,10 @@ config CPU_IDLE_GOV_HALTPOLL
> >  config DT_IDLE_STATES
> >         bool
> >
> > +config DT_IDLE_GENPD
> > +       depends on PM_GENERIC_DOMAINS_OF
> > +       bool
> > +
> >  menu "ARM CPU Idle Drivers"
> >  depends on ARM || ARM64
> >  source "drivers/cpuidle/Kconfig.arm"
> > diff --git a/drivers/cpuidle/Kconfig.arm b/drivers/cpuidle/Kconfig.arm
> > index 0844fadc4be8..1007435ae298 100644
> > --- a/drivers/cpuidle/Kconfig.arm
> > +++ b/drivers/cpuidle/Kconfig.arm
> > @@ -27,6 +27,7 @@ config ARM_PSCI_CPUIDLE_DOMAIN
> >         bool "PSCI CPU idle Domain"
> >         depends on ARM_PSCI_CPUIDLE
> >         depends on PM_GENERIC_DOMAINS_OF
> > +       select DT_IDLE_GENPD
> >         default y
> >         help
> >           Select this to enable the PSCI based CPUidle driver to use PM domains,
> > diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile
> > index 26bbc5e74123..11a26cef279f 100644
> > --- a/drivers/cpuidle/Makefile
> > +++ b/drivers/cpuidle/Makefile
> > @@ -6,6 +6,7 @@
> >  obj-y += cpuidle.o driver.o governor.o sysfs.o governors/
> >  obj-$(CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED) += coupled.o
> >  obj-$(CONFIG_DT_IDLE_STATES)             += dt_idle_states.o
> > +obj-$(CONFIG_DT_IDLE_GENPD)              += dt_idle_genpd.o
> >  obj-$(CONFIG_ARCH_HAS_CPU_RELAX)         += poll_state.o
> >  obj-$(CONFIG_HALTPOLL_CPUIDLE)           += cpuidle-haltpoll.o
> >
> > diff --git a/drivers/cpuidle/cpuidle-psci-domain.c b/drivers/cpuidle/cpuidle-psci-domain.c
> > index ff2c3f8e4668..b0621d890ab7 100644
> > --- a/drivers/cpuidle/cpuidle-psci-domain.c
> > +++ b/drivers/cpuidle/cpuidle-psci-domain.c
> > @@ -16,17 +16,9 @@
> >  #include <linux/pm_domain.h>
> >  #include <linux/pm_runtime.h>
> >  #include <linux/psci.h>
> > -#include <linux/slab.h>
> > -#include <linux/string.h>
> >
> >  #include "cpuidle-psci.h"
> >
> > -struct psci_pd_provider {
> > -       struct list_head link;
> > -       struct device_node *node;
> > -};
> > -
> > -static LIST_HEAD(psci_pd_providers);
> >  static bool psci_pd_allow_domain_state;
> >
> >  static int psci_pd_power_off(struct generic_pm_domain *pd)
> > @@ -47,178 +39,6 @@ static int psci_pd_power_off(struct generic_pm_domain *pd)
> >         return 0;
> >  }
> >
> > -static int psci_pd_parse_state_nodes(struct genpd_power_state *states,
> > -                                    int state_count)
> > -{
> > -       int i, ret;
> > -       u32 psci_state, *psci_state_buf;
> > -
> > -       for (i = 0; i < state_count; i++) {
> > -               ret = psci_dt_parse_state_node(to_of_node(states[i].fwnode),
> > -                                       &psci_state);
> > -               if (ret)
> > -                       goto free_state;
> > -
> > -               psci_state_buf = kmalloc(sizeof(u32), GFP_KERNEL);
> > -               if (!psci_state_buf) {
> > -                       ret = -ENOMEM;
> > -                       goto free_state;
> > -               }
> > -               *psci_state_buf = psci_state;
> > -               states[i].data = psci_state_buf;
> > -       }
> > -
> > -       return 0;
> > -
> > -free_state:
> > -       i--;
> > -       for (; i >= 0; i--)
> > -               kfree(states[i].data);
> > -       return ret;
> > -}
> > -
> > -static int psci_pd_parse_states(struct device_node *np,
> > -                       struct genpd_power_state **states, int *state_count)
> > -{
> > -       int ret;
> > -
> > -       /* Parse the domain idle states. */
> > -       ret = of_genpd_parse_idle_states(np, states, state_count);
> > -       if (ret)
> > -               return ret;
> > -
> > -       /* Fill out the PSCI specifics for each found state. */
> > -       ret = psci_pd_parse_state_nodes(*states, *state_count);
> > -       if (ret)
> > -               kfree(*states);
> > -
> > -       return ret;
> > -}
> > -
> > -static void psci_pd_free_states(struct genpd_power_state *states,
> > -                               unsigned int state_count)
> > -{
> > -       int i;
> > -
> > -       for (i = 0; i < state_count; i++)
> > -               kfree(states[i].data);
> > -       kfree(states);
> > -}
> > -
> > -static int psci_pd_init(struct device_node *np, bool use_osi)
> > -{
> > -       struct generic_pm_domain *pd;
> > -       struct psci_pd_provider *pd_provider;
> > -       struct dev_power_governor *pd_gov;
> > -       struct genpd_power_state *states = NULL;
> > -       int ret = -ENOMEM, state_count = 0;
> > -
> > -       pd = kzalloc(sizeof(*pd), GFP_KERNEL);
> > -       if (!pd)
> > -               goto out;
> > -
> > -       pd_provider = kzalloc(sizeof(*pd_provider), GFP_KERNEL);
> > -       if (!pd_provider)
> > -               goto free_pd;
> > -
> > -       pd->name = kasprintf(GFP_KERNEL, "%pOF", np);
> > -       if (!pd->name)
> > -               goto free_pd_prov;
> > -
> > -       /*
> > -        * Parse the domain idle states and let genpd manage the state selection
> > -        * for those being compatible with "domain-idle-state".
> > -        */
> > -       ret = psci_pd_parse_states(np, &states, &state_count);
> > -       if (ret)
> > -               goto free_name;
> > -
> > -       pd->free_states = psci_pd_free_states;
> > -       pd->name = kbasename(pd->name);
> > -       pd->states = states;
> > -       pd->state_count = state_count;
> > -       pd->flags |= GENPD_FLAG_IRQ_SAFE | GENPD_FLAG_CPU_DOMAIN;
> > -
> > -       /* Allow power off when OSI has been successfully enabled. */
> > -       if (use_osi)
> > -               pd->power_off = psci_pd_power_off;
> > -       else
> > -               pd->flags |= GENPD_FLAG_ALWAYS_ON;
> > -
> > -       /* Use governor for CPU PM domains if it has some states to manage. */
> > -       pd_gov = state_count > 0 ? &pm_domain_cpu_gov : NULL;
> > -
> > -       ret = pm_genpd_init(pd, pd_gov, false);
> > -       if (ret) {
> > -               psci_pd_free_states(states, state_count);
> > -               goto free_name;
> > -       }
> > -
> > -       ret = of_genpd_add_provider_simple(np, pd);
> > -       if (ret)
> > -               goto remove_pd;
> > -
> > -       pd_provider->node = of_node_get(np);
> > -       list_add(&pd_provider->link, &psci_pd_providers);
> > -
> > -       pr_debug("init PM domain %s\n", pd->name);
> > -       return 0;
> > -
> > -remove_pd:
> > -       pm_genpd_remove(pd);
> > -free_name:
> > -       kfree(pd->name);
> > -free_pd_prov:
> > -       kfree(pd_provider);
> > -free_pd:
> > -       kfree(pd);
> > -out:
> > -       pr_err("failed to init PM domain ret=%d %pOF\n", ret, np);
> > -       return ret;
> > -}
> > -
> > -static void psci_pd_remove(void)
> > -{
> > -       struct psci_pd_provider *pd_provider, *it;
> > -       struct generic_pm_domain *genpd;
> > -
> > -       list_for_each_entry_safe(pd_provider, it, &psci_pd_providers, link) {
> > -               of_genpd_del_provider(pd_provider->node);
> > -
> > -               genpd = of_genpd_remove_last(pd_provider->node);
> > -               if (!IS_ERR(genpd))
> > -                       kfree(genpd);
> > -
> > -               of_node_put(pd_provider->node);
> > -               list_del(&pd_provider->link);
> > -               kfree(pd_provider);
> > -       }
> > -}
> > -
> > -static int psci_pd_init_topology(struct device_node *np)
> > -{
> > -       struct device_node *node;
> > -       struct of_phandle_args child, parent;
> > -       int ret;
> > -
> > -       for_each_child_of_node(np, node) {
> > -               if (of_parse_phandle_with_args(node, "power-domains",
> > -                                       "#power-domain-cells", 0, &parent))
> > -                       continue;
> > -
> > -               child.np = node;
> > -               child.args_count = 0;
> > -               ret = of_genpd_add_subdomain(&parent, &child);
> > -               of_node_put(parent.np);
> > -               if (ret) {
> > -                       of_node_put(node);
> > -                       return ret;
> > -               }
> > -       }
> > -
> > -       return 0;
> > -}
> > -
> >  static bool psci_pd_try_set_osi_mode(void)
> >  {
> >         int ret;
> > @@ -244,6 +64,10 @@ static void psci_cpuidle_domain_sync_state(struct device *dev)
> >         psci_pd_allow_domain_state = true;
> >  }
> >
> > +static struct dt_idle_genpd_ops psci_genpd_ops = {
> > +       .parse_state_node = psci_dt_parse_state_node,
> > +};
> > +
> >  static const struct of_device_id psci_of_match[] = {
> >         { .compatible = "arm,psci-1.0" },
> >         {}
> > @@ -252,48 +76,25 @@ static const struct of_device_id psci_of_match[] = {
> >  static int psci_cpuidle_domain_probe(struct platform_device *pdev)
> >  {
> >         struct device_node *np = pdev->dev.of_node;
> > -       struct device_node *node;
> >         bool use_osi;
> > -       int ret = 0, pd_count = 0;
> > +       int ret = 0;
> >
> >         if (!np)
> >                 return -ENODEV;
> >
> >         /* If OSI mode is supported, let's try to enable it. */
> >         use_osi = psci_pd_try_set_osi_mode();
> > +       if (use_osi)
> > +               psci_genpd_ops.power_off = psci_pd_power_off;
> >
> > -       /*
> > -        * Parse child nodes for the "#power-domain-cells" property and
> > -        * initialize a genpd/genpd-of-provider pair when it's found.
> > -        */
> > -       for_each_child_of_node(np, node) {
> > -               if (!of_find_property(node, "#power-domain-cells", NULL))
> > -                       continue;
> > -
> > -               ret = psci_pd_init(node, use_osi);
> > -               if (ret)
> > -                       goto put_node;
> > -
> > -               pd_count++;
> > -       }
> > -
> > -       /* Bail out if not using the hierarchical CPU topology. */
> > -       if (!pd_count)
> > -               goto no_pd;
> > -
> > -       /* Link genpd masters/subdomains to model the CPU topology. */
> > -       ret = psci_pd_init_topology(np);
> > +       /* Generic power domain probing based on DT node. */
> > +       ret = dt_idle_genpd_probe(&psci_genpd_ops, np);
> >         if (ret)
> > -               goto remove_pd;
> > +               goto no_pd;
> >
> >         pr_info("Initialized CPU PM domain topology\n");
> >         return 0;
> >
> > -put_node:
> > -       of_node_put(node);
> > -remove_pd:
> > -       psci_pd_remove();
> > -       pr_err("failed to create CPU PM domains ret=%d\n", ret);
> >  no_pd:
> >         if (use_osi)
> >                 psci_set_osi_mode(false);
> > @@ -314,28 +115,3 @@ static int __init psci_idle_init_domains(void)
> >         return platform_driver_register(&psci_cpuidle_domain_driver);
> >  }
> >  subsys_initcall(psci_idle_init_domains);
> > -
> > -struct device *psci_dt_attach_cpu(int cpu)
> > -{
> > -       struct device *dev;
> > -
> > -       dev = dev_pm_domain_attach_by_name(get_cpu_device(cpu), "psci");
> > -       if (IS_ERR_OR_NULL(dev))
> > -               return dev;
> > -
> > -       pm_runtime_irq_safe(dev);
> > -       if (cpu_online(cpu))
> > -               pm_runtime_get_sync(dev);
> > -
> > -       dev_pm_syscore_device(dev, true);
> > -
> > -       return dev;
> > -}
> > -
> > -void psci_dt_detach_cpu(struct device *dev)
> > -{
> > -       if (IS_ERR_OR_NULL(dev))
> > -               return;
> > -
> > -       dev_pm_domain_detach(dev, false);
> > -}
> > diff --git a/drivers/cpuidle/cpuidle-psci.h b/drivers/cpuidle/cpuidle-psci.h
> > index d8e925e84c27..70de1e3c00af 100644
> > --- a/drivers/cpuidle/cpuidle-psci.h
> > +++ b/drivers/cpuidle/cpuidle-psci.h
> > @@ -10,8 +10,19 @@ void psci_set_domain_state(u32 state);
> >  int psci_dt_parse_state_node(struct device_node *np, u32 *state);
> >
> >  #ifdef CONFIG_ARM_PSCI_CPUIDLE_DOMAIN
> > -struct device *psci_dt_attach_cpu(int cpu);
> > -void psci_dt_detach_cpu(struct device *dev);
> > +
> > +#include "dt_idle_genpd.h"
> > +
> > +static inline struct device *psci_dt_attach_cpu(int cpu)
> > +{
> > +       return dt_idle_genpd_attach_cpu(cpu, "psci");
> > +}
> > +
> > +static inline void psci_dt_detach_cpu(struct device *dev)
> > +{
> > +       dt_idle_genpd_detach_cpu(dev);
> > +}
> > +
> >  #else
> >  static inline struct device *psci_dt_attach_cpu(int cpu) { return NULL; }
> >  static inline void psci_dt_detach_cpu(struct device *dev) { }
> > diff --git a/drivers/cpuidle/cpuidle-psci-domain.c b/drivers/cpuidle/dt_idle_genpd.c
> > similarity index 52%
> > copy from drivers/cpuidle/cpuidle-psci-domain.c
> > copy to drivers/cpuidle/dt_idle_genpd.c
> > index ff2c3f8e4668..805c4c81d60f 100644
> > --- a/drivers/cpuidle/cpuidle-psci-domain.c
> > +++ b/drivers/cpuidle/dt_idle_genpd.c
> > @@ -1,71 +1,52 @@
> > -// SPDX-License-Identifier: GPL-2.0
> > +// SPDX-License-Identifier: GPL-2.0-only
> >  /*
> > - * PM domains for CPUs via genpd - managed by cpuidle-psci.
> > + * PM domains for CPUs via genpd.
> >   *
> >   * Copyright (C) 2019 Linaro Ltd.
> >   * Author: Ulf Hansson <ulf.hansson@linaro.org>
> >   *
> > + * Copyright (c) 2021 Western Digital Corporation or its affiliates.
> >   */
> >
> > -#define pr_fmt(fmt) "CPUidle PSCI: " fmt
> > +#define pr_fmt(fmt) "dt-idle-genpd: " fmt
> >
> >  #include <linux/cpu.h>
> >  #include <linux/device.h>
> >  #include <linux/kernel.h>
> > -#include <linux/platform_device.h>
> >  #include <linux/pm_domain.h>
> >  #include <linux/pm_runtime.h>
> > -#include <linux/psci.h>
> >  #include <linux/slab.h>
> >  #include <linux/string.h>
> >
> > -#include "cpuidle-psci.h"
> > +#include "dt_idle_genpd.h"
> >
> > -struct psci_pd_provider {
> > +struct dt_pd_provider {
> >         struct list_head link;
> >         struct device_node *node;
> >  };
> >
> > -static LIST_HEAD(psci_pd_providers);
> > -static bool psci_pd_allow_domain_state;
> > +static LIST_HEAD(dt_pd_providers);
> >
> > -static int psci_pd_power_off(struct generic_pm_domain *pd)
> > -{
> > -       struct genpd_power_state *state = &pd->states[pd->state_idx];
> > -       u32 *pd_state;
> > -
> > -       if (!state->data)
> > -               return 0;
> > -
> > -       if (!psci_pd_allow_domain_state)
> > -               return -EBUSY;
> > -
> > -       /* OSI mode is enabled, set the corresponding domain state. */
> > -       pd_state = state->data;
> > -       psci_set_domain_state(*pd_state);
> > -
> > -       return 0;
> > -}
> > -
> > -static int psci_pd_parse_state_nodes(struct genpd_power_state *states,
> > -                                    int state_count)
> > +static int dt_pd_parse_state_nodes(const struct dt_idle_genpd_ops *ops,
> > +                                  struct genpd_power_state *states,
> > +                                  int state_count)
> >  {
> >         int i, ret;
> > -       u32 psci_state, *psci_state_buf;
> > +       u32 state, *state_buf;
> >
> >         for (i = 0; i < state_count; i++) {
> > -               ret = psci_dt_parse_state_node(to_of_node(states[i].fwnode),
> > -                                       &psci_state);
> > +               ret = ops->parse_state_node(to_of_node(states[i].fwnode),
> > +                                           &state);
> >                 if (ret)
> >                         goto free_state;
> >
> > -               psci_state_buf = kmalloc(sizeof(u32), GFP_KERNEL);
> > -               if (!psci_state_buf) {
> > +               state_buf = kmalloc(sizeof(u32), GFP_KERNEL);
> > +               if (!state_buf) {
> >                         ret = -ENOMEM;
> >                         goto free_state;
> >                 }
> > -               *psci_state_buf = psci_state;
> > -               states[i].data = psci_state_buf;
> > +               *state_buf = state;
> > +               states[i].data = state_buf;
> >         }
> >
> >         return 0;
> > @@ -77,8 +58,10 @@ static int psci_pd_parse_state_nodes(struct genpd_power_state *states,
> >         return ret;
> >  }
> >
> > -static int psci_pd_parse_states(struct device_node *np,
> > -                       struct genpd_power_state **states, int *state_count)
> > +static int dt_pd_parse_states(const struct dt_idle_genpd_ops *ops,
> > +                             struct device_node *np,
> > +                             struct genpd_power_state **states,
> > +                             int *state_count)
> >  {
> >         int ret;
> >
> > @@ -87,15 +70,15 @@ static int psci_pd_parse_states(struct device_node *np,
> >         if (ret)
> >                 return ret;
> >
> > -       /* Fill out the PSCI specifics for each found state. */
> > -       ret = psci_pd_parse_state_nodes(*states, *state_count);
> > +       /* Fill out the dt specifics for each found state. */
> > +       ret = dt_pd_parse_state_nodes(ops, *states, *state_count);
> >         if (ret)
> >                 kfree(*states);
> >
> >         return ret;
> >  }
> >
> > -static void psci_pd_free_states(struct genpd_power_state *states,
> > +static void dt_pd_free_states(struct genpd_power_state *states,
> >                                 unsigned int state_count)
> >  {
> >         int i;
> > @@ -105,10 +88,11 @@ static void psci_pd_free_states(struct genpd_power_state *states,
> >         kfree(states);
> >  }
> >
> > -static int psci_pd_init(struct device_node *np, bool use_osi)
> > +static int dt_pd_init(const struct dt_idle_genpd_ops *ops,
> > +                     struct device_node *np)
> >  {
> >         struct generic_pm_domain *pd;
> > -       struct psci_pd_provider *pd_provider;
> > +       struct dt_pd_provider *pd_provider;
> >         struct dev_power_governor *pd_gov;
> >         struct genpd_power_state *states = NULL;
> >         int ret = -ENOMEM, state_count = 0;
> > @@ -129,19 +113,19 @@ static int psci_pd_init(struct device_node *np, bool use_osi)
> >          * Parse the domain idle states and let genpd manage the state selection
> >          * for those being compatible with "domain-idle-state".
> >          */
> > -       ret = psci_pd_parse_states(np, &states, &state_count);
> > +       ret = dt_pd_parse_states(ops, np, &states, &state_count);
> >         if (ret)
> >                 goto free_name;
> >
> > -       pd->free_states = psci_pd_free_states;
> > +       pd->free_states = dt_pd_free_states;
> >         pd->name = kbasename(pd->name);
> >         pd->states = states;
> >         pd->state_count = state_count;
> >         pd->flags |= GENPD_FLAG_IRQ_SAFE | GENPD_FLAG_CPU_DOMAIN;
> >
> > -       /* Allow power off when OSI has been successfully enabled. */
> > -       if (use_osi)
> > -               pd->power_off = psci_pd_power_off;
> > +       /* Allow power off when available. */
> > +       if (ops->power_off)
> > +               pd->power_off = ops->power_off;
> >         else
> >                 pd->flags |= GENPD_FLAG_ALWAYS_ON;
> >
> > @@ -150,7 +134,7 @@ static int psci_pd_init(struct device_node *np, bool use_osi)
> >
> >         ret = pm_genpd_init(pd, pd_gov, false);
> >         if (ret) {
> > -               psci_pd_free_states(states, state_count);
> > +               dt_pd_free_states(states, state_count);
> >                 goto free_name;
> >         }
> >
> > @@ -159,7 +143,7 @@ static int psci_pd_init(struct device_node *np, bool use_osi)
> >                 goto remove_pd;
> >
> >         pd_provider->node = of_node_get(np);
> > -       list_add(&pd_provider->link, &psci_pd_providers);
> > +       list_add(&pd_provider->link, &dt_pd_providers);
> >
> >         pr_debug("init PM domain %s\n", pd->name);
> >         return 0;
> > @@ -177,12 +161,12 @@ static int psci_pd_init(struct device_node *np, bool use_osi)
> >         return ret;
> >  }
> >
> > -static void psci_pd_remove(void)
> > +static void dt_pd_remove(void)
> >  {
> > -       struct psci_pd_provider *pd_provider, *it;
> > +       struct dt_pd_provider *pd_provider, *it;
> >         struct generic_pm_domain *genpd;
> >
> > -       list_for_each_entry_safe(pd_provider, it, &psci_pd_providers, link) {
> > +       list_for_each_entry_safe(pd_provider, it, &dt_pd_providers, link) {
> >                 of_genpd_del_provider(pd_provider->node);
> >
> >                 genpd = of_genpd_remove_last(pd_provider->node);
> > @@ -195,7 +179,7 @@ static void psci_pd_remove(void)
> >         }
> >  }
> >
> > -static int psci_pd_init_topology(struct device_node *np)
> > +static int dt_pd_init_topology(struct device_node *np)
> >  {
> >         struct device_node *node;
> >         struct of_phandle_args child, parent;
> > @@ -219,49 +203,15 @@ static int psci_pd_init_topology(struct device_node *np)
> >         return 0;
> >  }
> >
> > -static bool psci_pd_try_set_osi_mode(void)
> > -{
> > -       int ret;
> > -
> > -       if (!psci_has_osi_support())
> > -               return false;
> > -
> > -       ret = psci_set_osi_mode(true);
> > -       if (ret) {
> > -               pr_warn("failed to enable OSI mode: %d\n", ret);
> > -               return false;
> > -       }
> > -
> > -       return true;
> > -}
> > -
> > -static void psci_cpuidle_domain_sync_state(struct device *dev)
> > +int dt_idle_genpd_probe(const struct dt_idle_genpd_ops *ops,
> > +                       struct device_node *np)
> >  {
> > -       /*
> > -        * All devices have now been attached/probed to the PM domain topology,
> > -        * hence it's fine to allow domain states to be picked.
> > -        */
> > -       psci_pd_allow_domain_state = true;
> > -}
> > -
> > -static const struct of_device_id psci_of_match[] = {
> > -       { .compatible = "arm,psci-1.0" },
> > -       {}
> > -};
> > -
> > -static int psci_cpuidle_domain_probe(struct platform_device *pdev)
> > -{
> > -       struct device_node *np = pdev->dev.of_node;
> >         struct device_node *node;
> > -       bool use_osi;
> >         int ret = 0, pd_count = 0;
> >
> > -       if (!np)
> > +       if (!np || !ops || !ops->parse_state_node)
> >                 return -ENODEV;
> >
> > -       /* If OSI mode is supported, let's try to enable it. */
> > -       use_osi = psci_pd_try_set_osi_mode();
> > -
> >         /*
> >          * Parse child nodes for the "#power-domain-cells" property and
> >          * initialize a genpd/genpd-of-provider pair when it's found.
> > @@ -270,7 +220,7 @@ static int psci_cpuidle_domain_probe(struct platform_device *pdev)
> >                 if (!of_find_property(node, "#power-domain-cells", NULL))
> >                         continue;
> >
> > -               ret = psci_pd_init(node, use_osi);
> > +               ret = dt_pd_init(ops, node);
> >                 if (ret)
> >                         goto put_node;
> >
> > @@ -282,44 +232,27 @@ static int psci_cpuidle_domain_probe(struct platform_device *pdev)
> >                 goto no_pd;
> >
> >         /* Link genpd masters/subdomains to model the CPU topology. */
> > -       ret = psci_pd_init_topology(np);
> > +       ret = dt_pd_init_topology(np);
> >         if (ret)
> >                 goto remove_pd;
> >
> > -       pr_info("Initialized CPU PM domain topology\n");
> >         return 0;
> >
> >  put_node:
> >         of_node_put(node);
> >  remove_pd:
> > -       psci_pd_remove();
> > +       dt_pd_remove();
> >         pr_err("failed to create CPU PM domains ret=%d\n", ret);
> >  no_pd:
> > -       if (use_osi)
> > -               psci_set_osi_mode(false);
> >         return ret;
> >  }
> > +EXPORT_SYMBOL_GPL(dt_idle_genpd_probe);
> >
> > -static struct platform_driver psci_cpuidle_domain_driver = {
> > -       .probe  = psci_cpuidle_domain_probe,
> > -       .driver = {
> > -               .name = "psci-cpuidle-domain",
> > -               .of_match_table = psci_of_match,
> > -               .sync_state = psci_cpuidle_domain_sync_state,
> > -       },
> > -};
> > -
> > -static int __init psci_idle_init_domains(void)
> > -{
> > -       return platform_driver_register(&psci_cpuidle_domain_driver);
> > -}
> > -subsys_initcall(psci_idle_init_domains);
> > -
> > -struct device *psci_dt_attach_cpu(int cpu)
> > +struct device *dt_idle_genpd_attach_cpu(int cpu, const char *name)
> >  {
> >         struct device *dev;
> >
> > -       dev = dev_pm_domain_attach_by_name(get_cpu_device(cpu), "psci");
> > +       dev = dev_pm_domain_attach_by_name(get_cpu_device(cpu), name);
> >         if (IS_ERR_OR_NULL(dev))
> >                 return dev;
> >
> > @@ -331,11 +264,13 @@ struct device *psci_dt_attach_cpu(int cpu)
> >
> >         return dev;
> >  }
> > +EXPORT_SYMBOL_GPL(dt_idle_genpd_attach_cpu);
> >
> > -void psci_dt_detach_cpu(struct device *dev)
> > +void dt_idle_genpd_detach_cpu(struct device *dev)
> >  {
> >         if (IS_ERR_OR_NULL(dev))
> >                 return;
> >
> >         dev_pm_domain_detach(dev, false);
> >  }
> > +EXPORT_SYMBOL_GPL(dt_idle_genpd_detach_cpu);
> > diff --git a/drivers/cpuidle/dt_idle_genpd.h b/drivers/cpuidle/dt_idle_genpd.h
> > new file mode 100644
> > index 000000000000..a3d3d2e85871
> > --- /dev/null
> > +++ b/drivers/cpuidle/dt_idle_genpd.h
> > @@ -0,0 +1,42 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +#ifndef __DT_IDLE_GENPD
> > +#define __DT_IDLE_GENPD
> > +
> > +struct device_node;
> > +struct generic_pm_domain;
> > +
> > +struct dt_idle_genpd_ops {
> > +       int (*parse_state_node)(struct device_node *np, u32 *state);
> > +       int (*power_off)(struct generic_pm_domain *pd);
> > +};
> > +
> > +#ifdef CONFIG_DT_IDLE_GENPD
> > +
> > +int dt_idle_genpd_probe(const struct dt_idle_genpd_ops *ops,
> > +                       struct device_node *np);
> > +
> > +struct device *dt_idle_genpd_attach_cpu(int cpu, const char *name);
> > +
> > +void dt_idle_genpd_detach_cpu(struct device *dev);
> > +
> > +#else
> > +
> > +int dt_idle_genpd_probe(const struct dt_idle_genpd_ops *ops,
> > +                       struct device_node *np)
> > +{
> > +       return 0;
> > +}
> > +
> > +static inline struct device *dt_idle_genpd_attach_cpu(int cpu,
> > +                                                     const char *name)
> > +{
> > +       return NULL;
> > +}
> > +
> > +static inline void dt_idle_genpd_detach_cpu(struct device *dev)
> > +{
> > +}
> > +
> > +#endif
> > +
> > +#endif
> > --
> > 2.25.1
> >

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^ permalink raw reply	[flat|nested] 12+ messages in thread

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Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-03-18 13:05 [RFC PATCH v3 0/8] RISC-V CPU Idle Support Anup Patel
2021-03-18 13:05 ` [RFC PATCH v3 1/8] RISC-V: Enable CPU_IDLE drivers Anup Patel
2021-03-18 13:05 ` [RFC PATCH v3 2/8] RISC-V: Rename relocate() and make it global Anup Patel
2021-03-18 13:05 ` [RFC PATCH v3 3/8] RISC-V: Add arch functions for non-retentive suspend entry/exit Anup Patel
2021-03-18 13:05 ` [RFC PATCH v3 4/8] RISC-V: Add SBI HSM suspend related defines Anup Patel
2021-03-18 13:05 ` [RFC PATCH v3 5/8] cpuidle: Factor-out power domain related code from PSCI domain driver Anup Patel
2021-04-15 13:01   ` Ulf Hansson
2021-05-09  4:49     ` Anup Patel
2021-03-18 13:05 ` [RFC PATCH v3 6/8] cpuidle: Add RISC-V SBI CPU idle driver Anup Patel
2021-03-18 13:05 ` [RFC PATCH v3 7/8] dt-bindings: Add common bindings for ARM and RISC-V idle states Anup Patel
2021-03-26  1:05   ` Rob Herring
2021-03-18 13:05 ` [RFC PATCH v3 8/8] RISC-V: Enable RISC-V SBI CPU Idle driver for QEMU virt machine Anup Patel

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