diff options
Diffstat (limited to 'drivers/firmware/psci.c')
| -rw-r--r-- | drivers/firmware/psci.c | 723 |
1 files changed, 723 insertions, 0 deletions
diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c new file mode 100644 index 000000000..d855c20de --- /dev/null +++ b/drivers/firmware/psci.c @@ -0,0 +1,723 @@ +/* + * 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) 2015 ARM Limited + */ + +#define pr_fmt(fmt) "psci: " fmt + +#include <linux/acpi.h> +#include <linux/arm-smccc.h> +#include <linux/cpuidle.h> +#include <linux/errno.h> +#include <linux/linkage.h> +#include <linux/of.h> +#include <linux/pm.h> +#include <linux/printk.h> +#include <linux/psci.h> +#include <linux/reboot.h> +#include <linux/slab.h> +#include <linux/suspend.h> + +#include <uapi/linux/psci.h> + +#include <asm/cpuidle.h> +#include <asm/cputype.h> +#include <asm/system_misc.h> +#include <asm/smp_plat.h> +#include <asm/suspend.h> + +/* + * While a 64-bit OS can make calls with SMC32 calling conventions, for some + * calls it is necessary to use SMC64 to pass or return 64-bit values. + * For such calls PSCI_FN_NATIVE(version, name) will choose the appropriate + * (native-width) function ID. + */ +#ifdef CONFIG_64BIT +#define PSCI_FN_NATIVE(version, name) PSCI_##version##_FN64_##name +#else +#define PSCI_FN_NATIVE(version, name) PSCI_##version##_FN_##name +#endif + +/* + * The CPU any Trusted OS is resident on. The trusted OS may reject CPU_OFF + * calls to its resident CPU, so we must avoid issuing those. We never migrate + * a Trusted OS even if it claims to be capable of migration -- doing so will + * require cooperation with a Trusted OS driver. + */ +static int resident_cpu = -1; + +bool psci_tos_resident_on(int cpu) +{ + return cpu == resident_cpu; +} + +struct psci_operations psci_ops = { + .conduit = PSCI_CONDUIT_NONE, + .smccc_version = SMCCC_VERSION_1_0, +}; + +enum arm_smccc_conduit arm_smccc_1_1_get_conduit(void) +{ + if (psci_ops.smccc_version < SMCCC_VERSION_1_1) + return SMCCC_CONDUIT_NONE; + + switch (psci_ops.conduit) { + case PSCI_CONDUIT_SMC: + return SMCCC_CONDUIT_SMC; + case PSCI_CONDUIT_HVC: + return SMCCC_CONDUIT_HVC; + default: + return SMCCC_CONDUIT_NONE; + } +} + +typedef unsigned long (psci_fn)(unsigned long, unsigned long, + unsigned long, unsigned long); +static psci_fn *invoke_psci_fn; + +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_0_2_POWER_STATE_MASK \ + (PSCI_0_2_POWER_STATE_ID_MASK | \ + PSCI_0_2_POWER_STATE_TYPE_MASK | \ + PSCI_0_2_POWER_STATE_AFFL_MASK) + +#define PSCI_1_0_EXT_POWER_STATE_MASK \ + (PSCI_1_0_EXT_POWER_STATE_ID_MASK | \ + PSCI_1_0_EXT_POWER_STATE_TYPE_MASK) + +static u32 psci_cpu_suspend_feature; + +static inline bool psci_has_ext_power_state(void) +{ + return psci_cpu_suspend_feature & + PSCI_1_0_FEATURES_CPU_SUSPEND_PF_MASK; +} + +static inline bool psci_power_state_loses_context(u32 state) +{ + const u32 mask = psci_has_ext_power_state() ? + PSCI_1_0_EXT_POWER_STATE_TYPE_MASK : + PSCI_0_2_POWER_STATE_TYPE_MASK; + + return state & mask; +} + +static inline bool psci_power_state_is_valid(u32 state) +{ + const u32 valid_mask = psci_has_ext_power_state() ? + PSCI_1_0_EXT_POWER_STATE_MASK : + PSCI_0_2_POWER_STATE_MASK; + + return !(state & ~valid_mask); +} + +static unsigned long __invoke_psci_fn_hvc(unsigned long function_id, + unsigned long arg0, unsigned long arg1, + unsigned long arg2) +{ + struct arm_smccc_res res; + + arm_smccc_hvc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res); + return res.a0; +} + +static unsigned long __invoke_psci_fn_smc(unsigned long function_id, + unsigned long arg0, unsigned long arg1, + unsigned long arg2) +{ + struct arm_smccc_res res; + + arm_smccc_smc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res); + return res.a0; +} + +static int psci_to_linux_errno(int errno) +{ + switch (errno) { + case PSCI_RET_SUCCESS: + return 0; + case PSCI_RET_NOT_SUPPORTED: + return -EOPNOTSUPP; + case PSCI_RET_INVALID_PARAMS: + case PSCI_RET_INVALID_ADDRESS: + return -EINVAL; + case PSCI_RET_DENIED: + return -EPERM; + }; + + return -EINVAL; +} + +static u32 psci_get_version(void) +{ + return invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0); +} + +static int psci_cpu_suspend(u32 state, unsigned long entry_point) +{ + int err; + u32 fn; + + fn = psci_function_id[PSCI_FN_CPU_SUSPEND]; + err = invoke_psci_fn(fn, state, entry_point, 0); + return psci_to_linux_errno(err); +} + +static int psci_cpu_off(u32 state) +{ + int err; + u32 fn; + + fn = psci_function_id[PSCI_FN_CPU_OFF]; + err = invoke_psci_fn(fn, 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 int psci_affinity_info(unsigned long target_affinity, + unsigned long lowest_affinity_level) +{ + return invoke_psci_fn(PSCI_FN_NATIVE(0_2, AFFINITY_INFO), + target_affinity, lowest_affinity_level, 0); +} + +static int psci_migrate_info_type(void) +{ + return invoke_psci_fn(PSCI_0_2_FN_MIGRATE_INFO_TYPE, 0, 0, 0); +} + +static unsigned long psci_migrate_info_up_cpu(void) +{ + return invoke_psci_fn(PSCI_FN_NATIVE(0_2, MIGRATE_INFO_UP_CPU), + 0, 0, 0); +} + +static void set_conduit(enum psci_conduit conduit) +{ + switch (conduit) { + case PSCI_CONDUIT_HVC: + invoke_psci_fn = __invoke_psci_fn_hvc; + break; + case PSCI_CONDUIT_SMC: + invoke_psci_fn = __invoke_psci_fn_smc; + break; + default: + WARN(1, "Unexpected PSCI conduit %d\n", conduit); + } + + psci_ops.conduit = conduit; +} + +static int get_set_conduit_method(struct device_node *np) +{ + const char *method; + + pr_info("probing for conduit method from DT.\n"); + + if (of_property_read_string(np, "method", &method)) { + pr_warn("missing \"method\" property\n"); + return -ENXIO; + } + + if (!strcmp("hvc", method)) { + set_conduit(PSCI_CONDUIT_HVC); + } else if (!strcmp("smc", method)) { + set_conduit(PSCI_CONDUIT_SMC); + } else { + pr_warn("invalid \"method\" property: %s\n", method); + return -EINVAL; + } + return 0; +} + +static void psci_sys_reset(enum reboot_mode reboot_mode, const char *cmd) +{ + invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0); +} + +static void psci_sys_poweroff(void) +{ + invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0); +} + +static int __init psci_features(u32 psci_func_id) +{ + return invoke_psci_fn(PSCI_1_0_FN_PSCI_FEATURES, + psci_func_id, 0, 0); +} + +#ifdef CONFIG_CPU_IDLE +static DEFINE_PER_CPU_READ_MOSTLY(u32 *, psci_power_state); + +static int psci_dt_cpu_init_idle(struct device_node *cpu_node, int cpu) +{ + int i, ret, count = 0; + u32 *psci_states; + struct device_node *state_node; + + /* Count idle states */ + while ((state_node = of_parse_phandle(cpu_node, "cpu-idle-states", + count))) { + count++; + of_node_put(state_node); + } + + if (!count) + return -ENODEV; + + psci_states = kcalloc(count, sizeof(*psci_states), GFP_KERNEL); + if (!psci_states) + return -ENOMEM; + + for (i = 0; i < count; i++) { + u32 state; + + state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i); + + ret = of_property_read_u32(state_node, + "arm,psci-suspend-param", + &state); + if (ret) { + pr_warn(" * %pOF missing arm,psci-suspend-param property\n", + state_node); + of_node_put(state_node); + goto free_mem; + } + + of_node_put(state_node); + pr_debug("psci-power-state %#x index %d\n", state, i); + if (!psci_power_state_is_valid(state)) { + pr_warn("Invalid PSCI power state %#x\n", state); + ret = -EINVAL; + goto free_mem; + } + psci_states[i] = state; + } + /* Idle states parsed correctly, initialize per-cpu pointer */ + per_cpu(psci_power_state, cpu) = psci_states; + return 0; + +free_mem: + kfree(psci_states); + return ret; +} + +#ifdef CONFIG_ACPI +#include <acpi/processor.h> + +static int __maybe_unused psci_acpi_cpu_init_idle(unsigned int cpu) +{ + int i, count; + u32 *psci_states; + struct acpi_lpi_state *lpi; + struct acpi_processor *pr = per_cpu(processors, cpu); + + if (unlikely(!pr || !pr->flags.has_lpi)) + return -EINVAL; + + count = pr->power.count - 1; + if (count <= 0) + return -ENODEV; + + psci_states = kcalloc(count, sizeof(*psci_states), GFP_KERNEL); + if (!psci_states) + return -ENOMEM; + + for (i = 0; i < count; i++) { + u32 state; + + lpi = &pr->power.lpi_states[i + 1]; + /* + * Only bits[31:0] represent a PSCI power_state while + * bits[63:32] must be 0x0 as per ARM ACPI FFH Specification + */ + state = lpi->address; + if (!psci_power_state_is_valid(state)) { + pr_warn("Invalid PSCI power state %#x\n", state); + kfree(psci_states); + return -EINVAL; + } + psci_states[i] = state; + } + /* Idle states parsed correctly, initialize per-cpu pointer */ + per_cpu(psci_power_state, cpu) = psci_states; + return 0; +} +#else +static int __maybe_unused psci_acpi_cpu_init_idle(unsigned int cpu) +{ + return -EINVAL; +} +#endif + +int psci_cpu_init_idle(unsigned int cpu) +{ + struct device_node *cpu_node; + int ret; + + /* + * If the PSCI cpu_suspend function hook has not been initialized + * idle states must not be enabled, so bail out + */ + if (!psci_ops.cpu_suspend) + return -EOPNOTSUPP; + + if (!acpi_disabled) + return psci_acpi_cpu_init_idle(cpu); + + cpu_node = of_get_cpu_node(cpu, NULL); + if (!cpu_node) + return -ENODEV; + + ret = psci_dt_cpu_init_idle(cpu_node, cpu); + + of_node_put(cpu_node); + + return ret; +} + +static int psci_suspend_finisher(unsigned long index) +{ + u32 *state = __this_cpu_read(psci_power_state); + + return psci_ops.cpu_suspend(state[index - 1], + __pa_symbol(cpu_resume)); +} + +int psci_cpu_suspend_enter(unsigned long index) +{ + int ret; + u32 *state = __this_cpu_read(psci_power_state); + /* + * idle state index 0 corresponds to wfi, should never be called + * from the cpu_suspend operations + */ + if (WARN_ON_ONCE(!index)) + return -EINVAL; + + if (!psci_power_state_loses_context(state[index - 1])) + ret = psci_ops.cpu_suspend(state[index - 1], 0); + else + ret = cpu_suspend(index, psci_suspend_finisher); + + return ret; +} + +/* ARM specific CPU idle operations */ +#ifdef CONFIG_ARM +static const struct cpuidle_ops psci_cpuidle_ops __initconst = { + .suspend = psci_cpu_suspend_enter, + .init = psci_dt_cpu_init_idle, +}; + +CPUIDLE_METHOD_OF_DECLARE(psci, "psci", &psci_cpuidle_ops); +#endif +#endif + +static int psci_system_suspend(unsigned long unused) +{ + return invoke_psci_fn(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND), + __pa_symbol(cpu_resume), 0, 0); +} + +static int psci_system_suspend_enter(suspend_state_t state) +{ + return cpu_suspend(0, psci_system_suspend); +} + +static const struct platform_suspend_ops psci_suspend_ops = { + .valid = suspend_valid_only_mem, + .enter = psci_system_suspend_enter, +}; + +static void __init psci_init_system_suspend(void) +{ + int ret; + + if (!IS_ENABLED(CONFIG_SUSPEND)) + return; + + ret = psci_features(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND)); + + if (ret != PSCI_RET_NOT_SUPPORTED) + suspend_set_ops(&psci_suspend_ops); +} + +static void __init psci_init_cpu_suspend(void) +{ + int feature = psci_features(psci_function_id[PSCI_FN_CPU_SUSPEND]); + + if (feature != PSCI_RET_NOT_SUPPORTED) + psci_cpu_suspend_feature = feature; +} + +/* + * Detect the presence of a resident Trusted OS which may cause CPU_OFF to + * return DENIED (which would be fatal). + */ +static void __init psci_init_migrate(void) +{ + unsigned long cpuid; + int type, cpu = -1; + + type = psci_ops.migrate_info_type(); + + if (type == PSCI_0_2_TOS_MP) { + pr_info("Trusted OS migration not required\n"); + return; + } + + if (type == PSCI_RET_NOT_SUPPORTED) { + pr_info("MIGRATE_INFO_TYPE not supported.\n"); + return; + } + + if (type != PSCI_0_2_TOS_UP_MIGRATE && + type != PSCI_0_2_TOS_UP_NO_MIGRATE) { + pr_err("MIGRATE_INFO_TYPE returned unknown type (%d)\n", type); + return; + } + + cpuid = psci_migrate_info_up_cpu(); + if (cpuid & ~MPIDR_HWID_BITMASK) { + pr_warn("MIGRATE_INFO_UP_CPU reported invalid physical ID (0x%lx)\n", + cpuid); + return; + } + + cpu = get_logical_index(cpuid); + resident_cpu = cpu >= 0 ? cpu : -1; + + pr_info("Trusted OS resident on physical CPU 0x%lx\n", cpuid); +} + +static void __init psci_init_smccc(void) +{ + u32 ver = ARM_SMCCC_VERSION_1_0; + int feature; + + feature = psci_features(ARM_SMCCC_VERSION_FUNC_ID); + + if (feature != PSCI_RET_NOT_SUPPORTED) { + u32 ret; + ret = invoke_psci_fn(ARM_SMCCC_VERSION_FUNC_ID, 0, 0, 0); + if (ret == ARM_SMCCC_VERSION_1_1) { + psci_ops.smccc_version = SMCCC_VERSION_1_1; + ver = ret; + } + } + + /* + * Conveniently, the SMCCC and PSCI versions are encoded the + * same way. No, this isn't accidental. + */ + pr_info("SMC Calling Convention v%d.%d\n", + PSCI_VERSION_MAJOR(ver), PSCI_VERSION_MINOR(ver)); + +} + +static void __init psci_0_2_set_functions(void) +{ + pr_info("Using standard PSCI v0.2 function IDs\n"); + psci_ops.get_version = psci_get_version; + + psci_function_id[PSCI_FN_CPU_SUSPEND] = + PSCI_FN_NATIVE(0_2, CPU_SUSPEND); + psci_ops.cpu_suspend = psci_cpu_suspend; + + psci_function_id[PSCI_FN_CPU_OFF] = PSCI_0_2_FN_CPU_OFF; + psci_ops.cpu_off = psci_cpu_off; + + psci_function_id[PSCI_FN_CPU_ON] = PSCI_FN_NATIVE(0_2, CPU_ON); + psci_ops.cpu_on = psci_cpu_on; + + psci_function_id[PSCI_FN_MIGRATE] = PSCI_FN_NATIVE(0_2, MIGRATE); + psci_ops.migrate = psci_migrate; + + psci_ops.affinity_info = psci_affinity_info; + + psci_ops.migrate_info_type = psci_migrate_info_type; + + arm_pm_restart = psci_sys_reset; + + pm_power_off = psci_sys_poweroff; +} + +/* + * Probe function for PSCI firmware versions >= 0.2 + */ +static int __init psci_probe(void) +{ + u32 ver = psci_get_version(); + + pr_info("PSCIv%d.%d detected in firmware.\n", + PSCI_VERSION_MAJOR(ver), + PSCI_VERSION_MINOR(ver)); + + if (PSCI_VERSION_MAJOR(ver) == 0 && PSCI_VERSION_MINOR(ver) < 2) { + pr_err("Conflicting PSCI version detected.\n"); + return -EINVAL; + } + + psci_0_2_set_functions(); + + psci_init_migrate(); + + if (PSCI_VERSION_MAJOR(ver) >= 1) { + psci_init_smccc(); + psci_init_cpu_suspend(); + psci_init_system_suspend(); + } + + return 0; +} + +typedef int (*psci_initcall_t)(const struct device_node *); + +/* + * PSCI init function for PSCI versions >=0.2 + * + * Probe based on PSCI PSCI_VERSION function + */ +static int __init psci_0_2_init(struct device_node *np) +{ + int err; + + err = get_set_conduit_method(np); + + if (err) + goto out_put_node; + /* + * Starting with v0.2, the PSCI specification introduced a call + * (PSCI_VERSION) that allows probing the firmware version, so + * that PSCI function IDs and version specific initialization + * can be carried out according to the specific version reported + * by firmware + */ + err = psci_probe(); + +out_put_node: + of_node_put(np); + return err; +} + +/* + * PSCI < v0.2 get PSCI Function IDs via DT. + */ +static int __init psci_0_1_init(struct device_node *np) +{ + u32 id; + int err; + + err = get_set_conduit_method(np); + + if (err) + goto out_put_node; + + pr_info("Using PSCI v0.1 Function IDs from DT\n"); + + 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 err; +} + +static const struct of_device_id psci_of_match[] __initconst = { + { .compatible = "arm,psci", .data = psci_0_1_init}, + { .compatible = "arm,psci-0.2", .data = psci_0_2_init}, + { .compatible = "arm,psci-1.0", .data = psci_0_2_init}, + {}, +}; + +int __init psci_dt_init(void) +{ + struct device_node *np; + const struct of_device_id *matched_np; + psci_initcall_t init_fn; + + np = of_find_matching_node_and_match(NULL, psci_of_match, &matched_np); + + if (!np || !of_device_is_available(np)) + return -ENODEV; + + init_fn = (psci_initcall_t)matched_np->data; + return init_fn(np); +} + +#ifdef CONFIG_ACPI +/* + * We use PSCI 0.2+ when ACPI is deployed on ARM64 and it's + * explicitly clarified in SBBR + */ +int __init psci_acpi_init(void) +{ + if (!acpi_psci_present()) { + pr_info("is not implemented in ACPI.\n"); + return -EOPNOTSUPP; + } + + pr_info("probing for conduit method from ACPI.\n"); + + if (acpi_psci_use_hvc()) + set_conduit(PSCI_CONDUIT_HVC); + else + set_conduit(PSCI_CONDUIT_SMC); + + return psci_probe(); +} +#endif |