diff --git a/Documentation/devicetree/bindings/arm/msm/qcom,idle-state.txt b/Documentation/devicetree/bindings/arm/msm/qcom,idle-state.txt index 6ce0b212ec6d..606b4b1b709d 100644 --- a/Documentation/devicetree/bindings/arm/msm/qcom,idle-state.txt +++ b/Documentation/devicetree/bindings/arm/msm/qcom,idle-state.txt @@ -81,4 +81,4 @@ Example: }; }; -[1]. Documentation/devicetree/bindings/arm/idle-states.yaml +[1]. Documentation/devicetree/bindings/cpu/idle-states.yaml diff --git a/Documentation/devicetree/bindings/arm/psci.yaml b/Documentation/devicetree/bindings/arm/psci.yaml index 8b77cf83a095..dd83ef278af0 100644 --- a/Documentation/devicetree/bindings/arm/psci.yaml +++ b/Documentation/devicetree/bindings/arm/psci.yaml @@ -101,7 +101,7 @@ properties: bindings in [1]) must specify this property. [1] Kernel documentation - ARM idle states bindings - Documentation/devicetree/bindings/arm/idle-states.yaml + Documentation/devicetree/bindings/cpu/idle-states.yaml patternProperties: "^power-domain-": 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..95506ffb816c 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 + - Anup Patel 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 + enum: + - arm,idle-state + - 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 aa5fb64d57eb..f62f646bc695 100644 --- a/Documentation/devicetree/bindings/riscv/cpus.yaml +++ b/Documentation/devicetree/bindings/riscv/cpus.yaml @@ -99,6 +99,12 @@ 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 diff --git a/MAINTAINERS b/MAINTAINERS index 51e1fd934432..47d9c1f18227 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -5069,6 +5069,20 @@ S: Supported F: drivers/cpuidle/cpuidle-psci.h F: drivers/cpuidle/cpuidle-psci-domain.c +CPUIDLE DRIVER - DT IDLE PM DOMAIN +M: Ulf Hansson +L: linux-pm@vger.kernel.org +S: Supported +F: drivers/cpuidle/dt_idle_genpd.c +F: drivers/cpuidle/dt_idle_genpd.h + +CPUIDLE DRIVER - RISC-V SBI +M: Anup Patel +L: linux-pm@vger.kernel.org +L: linux-riscv@lists.infradead.org +S: Maintained +F: drivers/cpuidle/cpuidle-riscv-sbi.c + CRAMFS FILESYSTEM M: Nicolas Pitre S: Maintained diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 73f36acb71ba..00fd9c548f26 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -48,6 +48,7 @@ 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 @@ -534,4 +535,10 @@ source "kernel/power/Kconfig" endmenu +menu "CPU Power Management" + +source "drivers/cpuidle/Kconfig" + +endmenu + source "arch/riscv/kvm/Kconfig" diff --git a/arch/riscv/Kconfig.socs b/arch/riscv/Kconfig.socs index c112ab2a9052..34592d00dde8 100644 --- a/arch/riscv/Kconfig.socs +++ b/arch/riscv/Kconfig.socs @@ -36,6 +36,9 @@ 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 7cd10ded7bf8..9249ef7bcee7 100644 --- a/arch/riscv/configs/defconfig +++ b/arch/riscv/configs/defconfig @@ -20,6 +20,8 @@ CONFIG_SOC_SIFIVE=y CONFIG_SOC_VIRT=y CONFIG_SMP=y CONFIG_HOTPLUG_CPU=y +CONFIG_PM=y +CONFIG_CPU_IDLE=y CONFIG_VIRTUALIZATION=y CONFIG_KVM=m CONFIG_JUMP_LABEL=y diff --git a/arch/riscv/configs/rv32_defconfig b/arch/riscv/configs/rv32_defconfig index e0e5c7c09ab8..17037d5f3ba3 100644 --- a/arch/riscv/configs/rv32_defconfig +++ b/arch/riscv/configs/rv32_defconfig @@ -20,6 +20,8 @@ CONFIG_SOC_VIRT=y CONFIG_ARCH_RV32I=y CONFIG_SMP=y CONFIG_HOTPLUG_CPU=y +CONFIG_PM=y +CONFIG_CPU_IDLE=y CONFIG_VIRTUALIZATION=y CONFIG_KVM=m CONFIG_JUMP_LABEL=y diff --git a/arch/riscv/include/asm/asm.h b/arch/riscv/include/asm/asm.h index 618d7c5af1a2..8c2549b16ac0 100644 --- a/arch/riscv/include/asm/asm.h +++ b/arch/riscv/include/asm/asm.h @@ -67,4 +67,30 @@ #error "Unexpected __SIZEOF_SHORT__" #endif +#ifdef __ASSEMBLY__ + +/* Common assembly source macros */ + +#ifdef CONFIG_XIP_KERNEL +.macro XIP_FIXUP_OFFSET reg + REG_L t0, _xip_fixup + add \reg, \reg, t0 +.endm +.macro XIP_FIXUP_FLASH_OFFSET reg + la t1, __data_loc + REG_L t1, _xip_phys_offset + sub \reg, \reg, t1 + add \reg, \reg, t0 +.endm +_xip_fixup: .dword CONFIG_PHYS_RAM_BASE - CONFIG_XIP_PHYS_ADDR - XIP_OFFSET +_xip_phys_offset: .dword CONFIG_XIP_PHYS_ADDR + XIP_OFFSET +#else +.macro XIP_FIXUP_OFFSET reg +.endm +.macro XIP_FIXUP_FLASH_OFFSET reg +.endm +#endif /* CONFIG_XIP_KERNEL */ + +#endif /* __ASSEMBLY__ */ + #endif /* _ASM_RISCV_ASM_H */ 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 +#include + +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/include/asm/suspend.h b/arch/riscv/include/asm/suspend.h new file mode 100644 index 000000000000..8be391c2aecb --- /dev/null +++ b/arch/riscv/include/asm/suspend.h @@ -0,0 +1,36 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (c) 2021 Western Digital Corporation or its affiliates. + * Copyright (c) 2022 Ventana Micro Systems Inc. + */ + +#ifndef _ASM_RISCV_SUSPEND_H +#define _ASM_RISCV_SUSPEND_H + +#include + +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 e0133d113216..87adbe47bc15 100644 --- a/arch/riscv/kernel/Makefile +++ b/arch/riscv/kernel/Makefile @@ -48,6 +48,8 @@ obj-$(CONFIG_RISCV_BOOT_SPINWAIT) += 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 df0519a64eaf..df9444397908 100644 --- a/arch/riscv/kernel/asm-offsets.c +++ b/arch/riscv/kernel/asm-offsets.c @@ -13,6 +13,7 @@ #include #include #include +#include void asm_offsets(void); @@ -113,6 +114,8 @@ void asm_offsets(void) OFFSET(PT_BADADDR, pt_regs, badaddr); OFFSET(PT_CAUSE, pt_regs, cause); + OFFSET(SUSPEND_CONTEXT_REGS, suspend_context, regs); + OFFSET(KVM_ARCH_GUEST_ZERO, kvm_vcpu_arch, guest_context.zero); OFFSET(KVM_ARCH_GUEST_RA, kvm_vcpu_arch, guest_context.ra); OFFSET(KVM_ARCH_GUEST_SP, kvm_vcpu_arch, guest_context.sp); diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S index ec07f991866a..893b8bb69391 100644 --- a/arch/riscv/kernel/head.S +++ b/arch/riscv/kernel/head.S @@ -16,26 +16,6 @@ #include #include "efi-header.S" -#ifdef CONFIG_XIP_KERNEL -.macro XIP_FIXUP_OFFSET reg - REG_L t0, _xip_fixup - add \reg, \reg, t0 -.endm -.macro XIP_FIXUP_FLASH_OFFSET reg - la t0, __data_loc - REG_L t1, _xip_phys_offset - sub \reg, \reg, t1 - add \reg, \reg, t0 -.endm -_xip_fixup: .dword CONFIG_PHYS_RAM_BASE - CONFIG_XIP_PHYS_ADDR - XIP_OFFSET -_xip_phys_offset: .dword CONFIG_XIP_PHYS_ADDR + XIP_OFFSET -#else -.macro XIP_FIXUP_OFFSET reg -.endm -.macro XIP_FIXUP_FLASH_OFFSET reg -.endm -#endif /* CONFIG_XIP_KERNEL */ - __HEAD ENTRY(_start) /* @@ -89,7 +69,8 @@ pe_head_start: .align 2 #ifdef CONFIG_MMU -relocate: + .global relocate_enable_mmu +relocate_enable_mmu: /* Relocate return address */ la a1, kernel_map XIP_FIXUP_OFFSET a1 @@ -184,7 +165,7 @@ secondary_start_sbi: /* Enable virtual memory and relocate to virtual address */ la a0, swapper_pg_dir XIP_FIXUP_OFFSET a0 - call relocate + call relocate_enable_mmu #endif call setup_trap_vector tail smp_callin @@ -328,7 +309,7 @@ clear_bss_done: #ifdef CONFIG_MMU la a0, early_pg_dir XIP_FIXUP_OFFSET a0 - call relocate + call relocate_enable_mmu #endif /* CONFIG_MMU */ call setup_trap_vector diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c index 03ac3aa611f5..504b496787aa 100644 --- a/arch/riscv/kernel/process.c +++ b/arch/riscv/kernel/process.c @@ -23,6 +23,7 @@ #include #include #include +#include register unsigned long gp_in_global __asm__("gp"); @@ -37,7 +38,7 @@ extern asmlinkage void ret_from_kernel_thread(void); void arch_cpu_idle(void) { - wait_for_interrupt(); + cpu_do_idle(); raw_local_irq_enable(); } diff --git a/arch/riscv/kernel/suspend.c b/arch/riscv/kernel/suspend.c new file mode 100644 index 000000000000..9ba24fb8cc93 --- /dev/null +++ b/arch/riscv/kernel/suspend.c @@ -0,0 +1,87 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2021 Western Digital Corporation or its affiliates. + * Copyright (c) 2022 Ventana Micro Systems Inc. + */ + +#include +#include +#include + +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..4b07b809a2b8 --- /dev/null +++ b/arch/riscv/kernel/suspend_entry.S @@ -0,0 +1,124 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (c) 2021 Western Digital Corporation or its affiliates. + * Copyright (c) 2022 Ventana Micro Systems Inc. + */ + +#include +#include +#include +#include + + .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) + /* Load the global pointer */ + .option push + .option norelax + la gp, __global_pointer$ + .option pop + +#ifdef CONFIG_MMU + /* Save A0 and A1 */ + add t0, a0, zero + add t1, a1, zero + + /* Enable MMU */ + la a0, swapper_pg_dir + XIP_FIXUP_OFFSET a0 + 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) diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig index c0aeedd66f02..ff71dd662880 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" @@ -62,6 +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.arm b/drivers/cpuidle/Kconfig.arm index 15d6c46c0a47..be7f512109f7 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/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 26bbc5e74123..d103342b7cfc 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-$(CONFIG_HALTPOLL_CPUIDLE) += cpuidle-haltpoll.o @@ -34,3 +35,7 @@ obj-$(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-riscv-sbi.o diff --git a/drivers/cpuidle/cpuidle-psci-domain.c b/drivers/cpuidle/cpuidle-psci-domain.c index ff2c3f8e4668..755bbdfc5b82 100644 --- a/drivers/cpuidle/cpuidle-psci-domain.c +++ b/drivers/cpuidle/cpuidle-psci-domain.c @@ -47,73 +47,14 @@ 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); + pd = dt_idle_pd_alloc(np, psci_dt_parse_state_node); if (!pd) goto out; @@ -121,22 +62,6 @@ static int psci_pd_init(struct device_node *np, bool use_osi) 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. */ @@ -149,10 +74,8 @@ static int psci_pd_init(struct device_node *np, bool use_osi) 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; - } + if (ret) + goto free_pd_prov; ret = of_genpd_add_provider_simple(np, pd); if (ret) @@ -166,12 +89,10 @@ static int psci_pd_init(struct device_node *np, bool use_osi) remove_pd: pm_genpd_remove(pd); -free_name: - kfree(pd->name); free_pd_prov: kfree(pd_provider); free_pd: - kfree(pd); + dt_idle_pd_free(pd); out: pr_err("failed to init PM domain ret=%d %pOF\n", ret, np); return ret; @@ -195,30 +116,6 @@ static void psci_pd_remove(void) } } -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; @@ -282,7 +179,7 @@ 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_idle_pd_init_topology(np); if (ret) goto remove_pd; @@ -314,28 +211,3 @@ 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..4e132640ed64 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_attach_cpu(cpu, "psci"); +} + +static inline void psci_dt_detach_cpu(struct device *dev) +{ + dt_idle_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-riscv-sbi.c b/drivers/cpuidle/cpuidle-riscv-sbi.c new file mode 100644 index 000000000000..b459eda2cd37 --- /dev/null +++ b/drivers/cpuidle/cpuidle-riscv-sbi.c @@ -0,0 +1,627 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * RISC-V SBI CPU idle driver. + * + * Copyright (c) 2021 Western Digital Corporation or its affiliates. + * Copyright (c) 2022 Ventana Micro Systems Inc. + */ + +#define pr_fmt(fmt) "cpuidle-riscv-sbi: " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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_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_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 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; +} + +#ifdef CONFIG_DT_IDLE_GENPD + +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; +} + +struct sbi_pd_provider { + struct list_head link; + struct device_node *node; +}; + +static LIST_HEAD(sbi_pd_providers); + +static int sbi_pd_init(struct device_node *np) +{ + struct generic_pm_domain *pd; + struct sbi_pd_provider *pd_provider; + struct dev_power_governor *pd_gov; + int ret = -ENOMEM, state_count = 0; + + pd = dt_idle_pd_alloc(np, sbi_dt_parse_state_node); + if (!pd) + goto out; + + pd_provider = kzalloc(sizeof(*pd_provider), GFP_KERNEL); + if (!pd_provider) + goto free_pd; + + pd->flags |= GENPD_FLAG_IRQ_SAFE | GENPD_FLAG_CPU_DOMAIN; + + /* Allow power off when OSI is available. */ + if (sbi_cpuidle_use_osi) + pd->power_off = sbi_cpuidle_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) + goto free_pd_prov; + + 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, &sbi_pd_providers); + + pr_debug("init PM domain %s\n", pd->name); + return 0; + +remove_pd: + pm_genpd_remove(pd); +free_pd_prov: + kfree(pd_provider); +free_pd: + dt_idle_pd_free(pd); +out: + pr_err("failed to init PM domain ret=%d %pOF\n", ret, np); + return ret; +} + +static void sbi_pd_remove(void) +{ + struct sbi_pd_provider *pd_provider, *it; + struct generic_pm_domain *genpd; + + list_for_each_entry_safe(pd_provider, it, &sbi_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 sbi_genpd_probe(struct device_node *np) +{ + struct device_node *node; + int ret = 0, pd_count = 0; + + if (!np) + return -ENODEV; + + /* + * 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 = sbi_pd_init(node); + 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 = dt_idle_pd_init_topology(np); + if (ret) + goto remove_pd; + + return 0; + +put_node: + of_node_put(node); +remove_pd: + sbi_pd_remove(); + pr_err("failed to create CPU PM domains ret=%d\n", ret); +no_pd: + return ret; +} + +#else + +static inline int sbi_genpd_probe(struct device_node *np) +{ + return 0; +} + +#endif + +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; + } + } + + /* Populate generic power domains from DT nodes */ + pds_node = of_find_node_by_path("/cpus/power-domains"); + if (pds_node) { + ret = sbi_genpd_probe(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); diff --git a/drivers/cpuidle/dt_idle_genpd.c b/drivers/cpuidle/dt_idle_genpd.c new file mode 100644 index 000000000000..b37165514d4e --- /dev/null +++ b/drivers/cpuidle/dt_idle_genpd.c @@ -0,0 +1,178 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * PM domains for CPUs via genpd. + * + * Copyright (C) 2019 Linaro Ltd. + * Author: Ulf Hansson + * + * Copyright (c) 2021 Western Digital Corporation or its affiliates. + * Copyright (c) 2022 Ventana Micro Systems Inc. + */ + +#define pr_fmt(fmt) "dt-idle-genpd: " fmt + +#include +#include +#include +#include +#include +#include +#include + +#include "dt_idle_genpd.h" + +static int pd_parse_state_nodes( + int (*parse_state)(struct device_node *, u32 *), + struct genpd_power_state *states, int state_count) +{ + int i, ret; + u32 state, *state_buf; + + for (i = 0; i < state_count; i++) { + ret = parse_state(to_of_node(states[i].fwnode), &state); + if (ret) + goto free_state; + + state_buf = kmalloc(sizeof(u32), GFP_KERNEL); + if (!state_buf) { + ret = -ENOMEM; + goto free_state; + } + *state_buf = state; + states[i].data = state_buf; + } + + return 0; + +free_state: + i--; + for (; i >= 0; i--) + kfree(states[i].data); + return ret; +} + +static int pd_parse_states(struct device_node *np, + int (*parse_state)(struct device_node *, u32 *), + 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 dt specifics for each found state. */ + ret = pd_parse_state_nodes(parse_state, *states, *state_count); + if (ret) + kfree(*states); + + return ret; +} + +static void 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); +} + +void dt_idle_pd_free(struct generic_pm_domain *pd) +{ + pd_free_states(pd->states, pd->state_count); + kfree(pd->name); + kfree(pd); +} + +struct generic_pm_domain *dt_idle_pd_alloc(struct device_node *np, + int (*parse_state)(struct device_node *, u32 *)) +{ + struct generic_pm_domain *pd; + struct genpd_power_state *states = NULL; + int ret, state_count = 0; + + pd = kzalloc(sizeof(*pd), GFP_KERNEL); + if (!pd) + goto out; + + pd->name = kasprintf(GFP_KERNEL, "%pOF", np); + if (!pd->name) + goto free_pd; + + /* + * Parse the domain idle states and let genpd manage the state selection + * for those being compatible with "domain-idle-state". + */ + ret = pd_parse_states(np, parse_state, &states, &state_count); + if (ret) + goto free_name; + + pd->free_states = pd_free_states; + pd->name = kbasename(pd->name); + pd->states = states; + pd->state_count = state_count; + + pr_debug("alloc PM domain %s\n", pd->name); + return pd; + +free_name: + kfree(pd->name); +free_pd: + kfree(pd); +out: + pr_err("failed to alloc PM domain %pOF\n", np); + return NULL; +} + +int dt_idle_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; +} + +struct device *dt_idle_attach_cpu(int cpu, const char *name) +{ + struct device *dev; + + dev = dev_pm_domain_attach_by_name(get_cpu_device(cpu), name); + 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 dt_idle_detach_cpu(struct device *dev) +{ + if (IS_ERR_OR_NULL(dev)) + return; + + dev_pm_domain_detach(dev, false); +} diff --git a/drivers/cpuidle/dt_idle_genpd.h b/drivers/cpuidle/dt_idle_genpd.h new file mode 100644 index 000000000000..a95483d08a02 --- /dev/null +++ b/drivers/cpuidle/dt_idle_genpd.h @@ -0,0 +1,50 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __DT_IDLE_GENPD +#define __DT_IDLE_GENPD + +struct device_node; +struct generic_pm_domain; + +#ifdef CONFIG_DT_IDLE_GENPD + +void dt_idle_pd_free(struct generic_pm_domain *pd); + +struct generic_pm_domain *dt_idle_pd_alloc(struct device_node *np, + int (*parse_state)(struct device_node *, u32 *)); + +int dt_idle_pd_init_topology(struct device_node *np); + +struct device *dt_idle_attach_cpu(int cpu, const char *name); + +void dt_idle_detach_cpu(struct device *dev); + +#else + +static inline void dt_idle_pd_free(struct generic_pm_domain *pd) +{ +} + +static inline struct generic_pm_domain *dt_idle_pd_alloc( + struct device_node *np, + int (*parse_state)(struct device_node *, u32 *)) +{ + return NULL; +} + +static inline int dt_idle_pd_init_topology(struct device_node *np) +{ + return 0; +} + +static inline struct device *dt_idle_attach_cpu(int cpu, const char *name) +{ + return NULL; +} + +static inline void dt_idle_detach_cpu(struct device *dev) +{ +} + +#endif + +#endif