diff options
| -rw-r--r-- | Documentation/devicetree/bindings/arm/psci.txt | 55 | ||||
| -rw-r--r-- | arch/arm/Kconfig | 10 | ||||
| -rw-r--r-- | arch/arm/include/asm/opcodes-sec.h | 24 | ||||
| -rw-r--r-- | arch/arm/include/asm/opcodes.h | 1 | ||||
| -rw-r--r-- | arch/arm/include/asm/psci.h | 36 | ||||
| -rw-r--r-- | arch/arm/kernel/Makefile | 1 | ||||
| -rw-r--r-- | arch/arm/kernel/psci.c | 211 |
7 files changed, 338 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/arm/psci.txt b/Documentation/devicetree/bindings/arm/psci.txt new file mode 100644 index 000000000000..433afe9cb590 --- /dev/null +++ b/Documentation/devicetree/bindings/arm/psci.txt @@ -0,0 +1,55 @@ +* Power State Coordination Interface (PSCI) + +Firmware implementing the PSCI functions described in ARM document number +ARM DEN 0022A ("Power State Coordination Interface System Software on ARM +processors") can be used by Linux to initiate various CPU-centric power +operations. + +Issue A of the specification describes functions for CPU suspend, hotplug +and migration of secure software. + +Functions are invoked by trapping to the privilege level of the PSCI +firmware (specified as part of the binding below) and passing arguments +in a manner similar to that specified by AAPCS: + + r0 => 32-bit Function ID / return value + {r1 - r3} => Parameters + +Note that the immediate field of the trapping instruction must be set +to #0. + + +Main node required properties: + + - compatible : Must be "arm,psci" + + - method : The method of calling the PSCI firmware. Permitted + values are: + + "smc" : SMC #0, with the register assignments specified + in this binding. + + "hvc" : HVC #0, with the register assignments specified + in this binding. + +Main node optional properties: + + - cpu_suspend : Function ID for CPU_SUSPEND operation + + - cpu_off : Function ID for CPU_OFF operation + + - cpu_on : Function ID for CPU_ON operation + + - migrate : Function ID for MIGRATE operation + + +Example: + + psci { + compatible = "arm,psci"; + method = "smc"; + cpu_suspend = <0x95c10000>; + cpu_off = <0x95c10001>; + cpu_on = <0x95c10002>; + migrate = <0x95c10003>; + }; diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 67874b82a4ed..96863b860641 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1620,6 +1620,16 @@ config HOTPLUG_CPU Say Y here to experiment with turning CPUs off and on. CPUs can be controlled through /sys/devices/system/cpu. +config ARM_PSCI + bool "Support for the ARM Power State Coordination Interface (PSCI)" + depends on CPU_V7 + help + Say Y here if you want Linux to communicate with system firmware + implementing the PSCI specification for CPU-centric power + management operations described in ARM document number ARM DEN + 0022A ("Power State Coordination Interface System Software on + ARM processors"). + config LOCAL_TIMERS bool "Use local timer interrupts" depends on SMP diff --git a/arch/arm/include/asm/opcodes-sec.h b/arch/arm/include/asm/opcodes-sec.h new file mode 100644 index 000000000000..bc3a9174417c --- /dev/null +++ b/arch/arm/include/asm/opcodes-sec.h @@ -0,0 +1,24 @@ +/* + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * Copyright (C) 2012 ARM Limited + */ + +#ifndef __ASM_ARM_OPCODES_SEC_H +#define __ASM_ARM_OPCODES_SEC_H + +#include <asm/opcodes.h> + +#define __SMC(imm4) __inst_arm_thumb32( \ + 0xE1600070 | (((imm4) & 0xF) << 0), \ + 0xF7F08000 | (((imm4) & 0xF) << 16) \ +) + +#endif /* __ASM_ARM_OPCODES_SEC_H */ diff --git a/arch/arm/include/asm/opcodes.h b/arch/arm/include/asm/opcodes.h index 74e211a6fb24..e796c598513b 100644 --- a/arch/arm/include/asm/opcodes.h +++ b/arch/arm/include/asm/opcodes.h @@ -10,6 +10,7 @@ #define __ASM_ARM_OPCODES_H #ifndef __ASSEMBLY__ +#include <linux/linkage.h> extern asmlinkage unsigned int arm_check_condition(u32 opcode, u32 psr); #endif diff --git a/arch/arm/include/asm/psci.h b/arch/arm/include/asm/psci.h new file mode 100644 index 000000000000..ce0dbe7c1625 --- /dev/null +++ b/arch/arm/include/asm/psci.h @@ -0,0 +1,36 @@ +/* + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * Copyright (C) 2012 ARM Limited + */ + +#ifndef __ASM_ARM_PSCI_H +#define __ASM_ARM_PSCI_H + +#define PSCI_POWER_STATE_TYPE_STANDBY 0 +#define PSCI_POWER_STATE_TYPE_POWER_DOWN 1 + +struct psci_power_state { + u16 id; + u8 type; + u8 affinity_level; +}; + +struct psci_operations { + int (*cpu_suspend)(struct psci_power_state state, + unsigned long entry_point); + int (*cpu_off)(struct psci_power_state state); + int (*cpu_on)(unsigned long cpuid, unsigned long entry_point); + int (*migrate)(unsigned long cpuid); +}; + +extern struct psci_operations psci_ops; + +#endif /* __ASM_ARM_PSCI_H */ diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index 5bbec7b8183e..5f3338eacad2 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -82,5 +82,6 @@ obj-$(CONFIG_DEBUG_LL) += debug.o obj-$(CONFIG_EARLY_PRINTK) += early_printk.o obj-$(CONFIG_ARM_VIRT_EXT) += hyp-stub.o +obj-$(CONFIG_ARM_PSCI) += psci.o extra-y := $(head-y) vmlinux.lds diff --git a/arch/arm/kernel/psci.c b/arch/arm/kernel/psci.c new file mode 100644 index 000000000000..36531643cc2c --- /dev/null +++ b/arch/arm/kernel/psci.c @@ -0,0 +1,211 @@ +/* + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * Copyright (C) 2012 ARM Limited + * + * Author: Will Deacon <will.deacon@arm.com> + */ + +#define pr_fmt(fmt) "psci: " fmt + +#include <linux/init.h> +#include <linux/of.h> + +#include <asm/compiler.h> +#include <asm/errno.h> +#include <asm/opcodes-sec.h> +#include <asm/opcodes-virt.h> +#include <asm/psci.h> + +struct psci_operations psci_ops; + +static int (*invoke_psci_fn)(u32, u32, u32, u32); + +enum psci_function { + PSCI_FN_CPU_SUSPEND, + PSCI_FN_CPU_ON, + PSCI_FN_CPU_OFF, + PSCI_FN_MIGRATE, + PSCI_FN_MAX, +}; + +static u32 psci_function_id[PSCI_FN_MAX]; + +#define PSCI_RET_SUCCESS 0 +#define PSCI_RET_EOPNOTSUPP -1 +#define PSCI_RET_EINVAL -2 +#define PSCI_RET_EPERM -3 + +static int psci_to_linux_errno(int errno) +{ + switch (errno) { + case PSCI_RET_SUCCESS: + return 0; + case PSCI_RET_EOPNOTSUPP: + return -EOPNOTSUPP; + case PSCI_RET_EINVAL: + return -EINVAL; + case PSCI_RET_EPERM: + return -EPERM; + }; + + return -EINVAL; +} + +#define PSCI_POWER_STATE_ID_MASK 0xffff +#define PSCI_POWER_STATE_ID_SHIFT 0 +#define PSCI_POWER_STATE_TYPE_MASK 0x1 +#define PSCI_POWER_STATE_TYPE_SHIFT 16 +#define PSCI_POWER_STATE_AFFL_MASK 0x3 +#define PSCI_POWER_STATE_AFFL_SHIFT 24 + +static u32 psci_power_state_pack(struct psci_power_state state) +{ + return ((state.id & PSCI_POWER_STATE_ID_MASK) + << PSCI_POWER_STATE_ID_SHIFT) | + ((state.type & PSCI_POWER_STATE_TYPE_MASK) + << PSCI_POWER_STATE_TYPE_SHIFT) | + ((state.affinity_level & PSCI_POWER_STATE_AFFL_MASK) + << PSCI_POWER_STATE_AFFL_SHIFT); +} + +/* + * The following two functions are invoked via the invoke_psci_fn pointer + * and will not be inlined, allowing us to piggyback on the AAPCS. + */ +static noinline int __invoke_psci_fn_hvc(u32 function_id, u32 arg0, u32 arg1, + u32 arg2) +{ + asm volatile( + __asmeq("%0", "r0") + __asmeq("%1", "r1") + __asmeq("%2", "r2") + __asmeq("%3", "r3") + __HVC(0) + : "+r" (function_id) + : "r" (arg0), "r" (arg1), "r" (arg2)); + + return function_id; +} + +static noinline int __invoke_psci_fn_smc(u32 function_id, u32 arg0, u32 arg1, + u32 arg2) +{ + asm volatile( + __asmeq("%0", "r0") + __asmeq("%1", "r1") + __asmeq("%2", "r2") + __asmeq("%3", "r3") + __SMC(0) + : "+r" (function_id) + : "r" (arg0), "r" (arg1), "r" (arg2)); + + return function_id; +} + +static int psci_cpu_suspend(struct psci_power_state state, + unsigned long entry_point) +{ + int err; + u32 fn, power_state; + + fn = psci_function_id[PSCI_FN_CPU_SUSPEND]; + power_state = psci_power_state_pack(state); + err = invoke_psci_fn(fn, power_state, entry_point, 0); + return psci_to_linux_errno(err); +} + +static int psci_cpu_off(struct psci_power_state state) +{ + int err; + u32 fn, power_state; + + fn = psci_function_id[PSCI_FN_CPU_OFF]; + power_state = psci_power_state_pack(state); + err = invoke_psci_fn(fn, power_state, 0, 0); + return psci_to_linux_errno(err); +} + +static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point) +{ + int err; + u32 fn; + + fn = psci_function_id[PSCI_FN_CPU_ON]; + err = invoke_psci_fn(fn, cpuid, entry_point, 0); + return psci_to_linux_errno(err); +} + +static int psci_migrate(unsigned long cpuid) +{ + int err; + u32 fn; + + fn = psci_function_id[PSCI_FN_MIGRATE]; + err = invoke_psci_fn(fn, cpuid, 0, 0); + return psci_to_linux_errno(err); +} + +static const struct of_device_id psci_of_match[] __initconst = { + { .compatible = "arm,psci", }, + {}, +}; + +static int __init psci_init(void) +{ + struct device_node *np; + const char *method; + u32 id; + + np = of_find_matching_node(NULL, psci_of_match); + if (!np) + return 0; + + pr_info("probing function IDs from device-tree\n"); + + if (of_property_read_string(np, "method", &method)) { + pr_warning("missing \"method\" property\n"); + goto out_put_node; + } + + if (!strcmp("hvc", method)) { + invoke_psci_fn = __invoke_psci_fn_hvc; + } else if (!strcmp("smc", method)) { + invoke_psci_fn = __invoke_psci_fn_smc; + } else { + pr_warning("invalid \"method\" property: %s\n", method); + goto out_put_node; + } + + if (!of_property_read_u32(np, "cpu_suspend", &id)) { + psci_function_id[PSCI_FN_CPU_SUSPEND] = id; + psci_ops.cpu_suspend = psci_cpu_suspend; + } + + if (!of_property_read_u32(np, "cpu_off", &id)) { + psci_function_id[PSCI_FN_CPU_OFF] = id; + psci_ops.cpu_off = psci_cpu_off; + } + + if (!of_property_read_u32(np, "cpu_on", &id)) { + psci_function_id[PSCI_FN_CPU_ON] = id; + psci_ops.cpu_on = psci_cpu_on; + } + + if (!of_property_read_u32(np, "migrate", &id)) { + psci_function_id[PSCI_FN_MIGRATE] = id; + psci_ops.migrate = psci_migrate; + } + +out_put_node: + of_node_put(np); + return 0; +} +early_initcall(psci_init); |
