| /* |
| * 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) 2013 ARM Limited |
| * |
| * Author: Will Deacon <will.deacon@arm.com> |
| */ |
| |
| #define pr_fmt(fmt) "psci: " fmt |
| |
| #include <linux/init.h> |
| #include <linux/of.h> |
| #include <linux/smp.h> |
| #include <linux/reboot.h> |
| #include <linux/pm.h> |
| #include <linux/delay.h> |
| #include <uapi/linux/psci.h> |
| |
| #include <asm/compiler.h> |
| #include <asm/cpu_ops.h> |
| #include <asm/errno.h> |
| #include <asm/psci.h> |
| #include <asm/smp_plat.h> |
| #include <asm/system_misc.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); |
| int (*affinity_info)(unsigned long target_affinity, |
| unsigned long lowest_affinity_level); |
| int (*migrate_info_type)(void); |
| }; |
| |
| static struct psci_operations psci_ops; |
| |
| static int (*invoke_psci_fn)(u64, u64, u64, u64); |
| typedef int (*psci_initcall_t)(const struct device_node *); |
| |
| enum psci_function { |
| PSCI_FN_CPU_SUSPEND, |
| PSCI_FN_CPU_ON, |
| PSCI_FN_CPU_OFF, |
| PSCI_FN_MIGRATE, |
| PSCI_FN_AFFINITY_INFO, |
| PSCI_FN_MIGRATE_INFO_TYPE, |
| PSCI_FN_MAX, |
| }; |
| |
| static u32 psci_function_id[PSCI_FN_MAX]; |
| |
| 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: |
| return -EINVAL; |
| case PSCI_RET_DENIED: |
| return -EPERM; |
| }; |
| |
| return -EINVAL; |
| } |
| |
| static u32 psci_power_state_pack(struct psci_power_state state) |
| { |
| return ((state.id << PSCI_0_2_POWER_STATE_ID_SHIFT) |
| & PSCI_0_2_POWER_STATE_ID_MASK) | |
| ((state.type << PSCI_0_2_POWER_STATE_TYPE_SHIFT) |
| & PSCI_0_2_POWER_STATE_TYPE_MASK) | |
| ((state.affinity_level << PSCI_0_2_POWER_STATE_AFFL_SHIFT) |
| & PSCI_0_2_POWER_STATE_AFFL_MASK); |
| } |
| |
| /* |
| * 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(u64 function_id, u64 arg0, u64 arg1, |
| u64 arg2) |
| { |
| asm volatile( |
| __asmeq("%0", "x0") |
| __asmeq("%1", "x1") |
| __asmeq("%2", "x2") |
| __asmeq("%3", "x3") |
| "hvc #0\n" |
| : "+r" (function_id) |
| : "r" (arg0), "r" (arg1), "r" (arg2)); |
| |
| return function_id; |
| } |
| |
| static noinline int __invoke_psci_fn_smc(u64 function_id, u64 arg0, u64 arg1, |
| u64 arg2) |
| { |
| asm volatile( |
| __asmeq("%0", "x0") |
| __asmeq("%1", "x1") |
| __asmeq("%2", "x2") |
| __asmeq("%3", "x3") |
| "smc #0\n" |
| : "+r" (function_id) |
| : "r" (arg0), "r" (arg1), "r" (arg2)); |
| |
| return function_id; |
| } |
| |
| static int psci_get_version(void) |
| { |
| int err; |
| |
| err = invoke_psci_fn(PSCI_0_2_FN_PSCI_VERSION, 0, 0, 0); |
| return err; |
| } |
| |
| 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 int psci_affinity_info(unsigned long target_affinity, |
| unsigned long lowest_affinity_level) |
| { |
| int err; |
| u32 fn; |
| |
| fn = psci_function_id[PSCI_FN_AFFINITY_INFO]; |
| err = invoke_psci_fn(fn, target_affinity, lowest_affinity_level, 0); |
| return err; |
| } |
| |
| static int psci_migrate_info_type(void) |
| { |
| int err; |
| u32 fn; |
| |
| fn = psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE]; |
| err = invoke_psci_fn(fn, 0, 0, 0); |
| return err; |
| } |
| |
| 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)) { |
| invoke_psci_fn = __invoke_psci_fn_hvc; |
| } else if (!strcmp("smc", method)) { |
| invoke_psci_fn = __invoke_psci_fn_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); |
| } |
| |
| /* |
| * PSCI Function IDs for v0.2+ are well defined so use |
| * standard values. |
| */ |
| static int psci_0_2_init(struct device_node *np) |
| { |
| int err, ver; |
| |
| err = get_set_conduit_method(np); |
| |
| if (err) |
| goto out_put_node; |
| |
| ver = psci_get_version(); |
| |
| if (ver == PSCI_RET_NOT_SUPPORTED) { |
| /* PSCI v0.2 mandates implementation of PSCI_ID_VERSION. */ |
| pr_err("PSCI firmware does not comply with the v0.2 spec.\n"); |
| err = -EOPNOTSUPP; |
| goto out_put_node; |
| } else { |
| 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) { |
| err = -EINVAL; |
| pr_err("Conflicting PSCI version detected.\n"); |
| goto out_put_node; |
| } |
| } |
| |
| pr_info("Using standard PSCI v0.2 function IDs\n"); |
| psci_function_id[PSCI_FN_CPU_SUSPEND] = PSCI_0_2_FN64_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_0_2_FN64_CPU_ON; |
| psci_ops.cpu_on = psci_cpu_on; |
| |
| psci_function_id[PSCI_FN_MIGRATE] = PSCI_0_2_FN64_MIGRATE; |
| psci_ops.migrate = psci_migrate; |
| |
| psci_function_id[PSCI_FN_AFFINITY_INFO] = PSCI_0_2_FN64_AFFINITY_INFO; |
| psci_ops.affinity_info = psci_affinity_info; |
| |
| psci_function_id[PSCI_FN_MIGRATE_INFO_TYPE] = |
| PSCI_0_2_FN_MIGRATE_INFO_TYPE; |
| psci_ops.migrate_info_type = psci_migrate_info_type; |
| |
| arm_pm_restart = psci_sys_reset; |
| |
| pm_power_off = psci_sys_poweroff; |
| |
| out_put_node: |
| of_node_put(np); |
| return err; |
| } |
| |
| /* |
| * PSCI < v0.2 get PSCI Function IDs via DT. |
| */ |
| static int 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}, |
| {}, |
| }; |
| |
| int __init psci_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) |
| return -ENODEV; |
| |
| init_fn = (psci_initcall_t)matched_np->data; |
| return init_fn(np); |
| } |
| |
| #ifdef CONFIG_SMP |
| |
| static int __init cpu_psci_cpu_init(struct device_node *dn, unsigned int cpu) |
| { |
| return 0; |
| } |
| |
| static int __init cpu_psci_cpu_prepare(unsigned int cpu) |
| { |
| if (!psci_ops.cpu_on) { |
| pr_err("no cpu_on method, not booting CPU%d\n", cpu); |
| return -ENODEV; |
| } |
| |
| return 0; |
| } |
| |
| static int cpu_psci_cpu_boot(unsigned int cpu) |
| { |
| int err = psci_ops.cpu_on(cpu_logical_map(cpu), __pa(secondary_entry)); |
| if (err) |
| pr_err("failed to boot CPU%d (%d)\n", cpu, err); |
| |
| return err; |
| } |
| |
| #ifdef CONFIG_HOTPLUG_CPU |
| static int cpu_psci_cpu_disable(unsigned int cpu) |
| { |
| /* Fail early if we don't have CPU_OFF support */ |
| if (!psci_ops.cpu_off) |
| return -EOPNOTSUPP; |
| return 0; |
| } |
| |
| static void cpu_psci_cpu_die(unsigned int cpu) |
| { |
| int ret; |
| /* |
| * There are no known implementations of PSCI actually using the |
| * power state field, pass a sensible default for now. |
| */ |
| struct psci_power_state state = { |
| .type = PSCI_POWER_STATE_TYPE_POWER_DOWN, |
| }; |
| |
| ret = psci_ops.cpu_off(state); |
| |
| pr_crit("unable to power off CPU%u (%d)\n", cpu, ret); |
| } |
| |
| static int cpu_psci_cpu_kill(unsigned int cpu) |
| { |
| int err, i; |
| |
| if (!psci_ops.affinity_info) |
| return 1; |
| /* |
| * cpu_kill could race with cpu_die and we can |
| * potentially end up declaring this cpu undead |
| * while it is dying. So, try again a few times. |
| */ |
| |
| for (i = 0; i < 10; i++) { |
| err = psci_ops.affinity_info(cpu_logical_map(cpu), 0); |
| if (err == PSCI_0_2_AFFINITY_LEVEL_OFF) { |
| pr_info("CPU%d killed.\n", cpu); |
| return 1; |
| } |
| |
| msleep(10); |
| pr_info("Retrying again to check for CPU kill\n"); |
| } |
| |
| pr_warn("CPU%d may not have shut down cleanly (AFFINITY_INFO reports %d)\n", |
| cpu, err); |
| /* Make op_cpu_kill() fail. */ |
| return 0; |
| } |
| #endif |
| |
| static const struct cpu_operations cpu_psci_ops = { |
| .name = "psci", |
| .cpu_init = cpu_psci_cpu_init, |
| .cpu_prepare = cpu_psci_cpu_prepare, |
| .cpu_boot = cpu_psci_cpu_boot, |
| #ifdef CONFIG_HOTPLUG_CPU |
| .cpu_disable = cpu_psci_cpu_disable, |
| .cpu_die = cpu_psci_cpu_die, |
| .cpu_kill = cpu_psci_cpu_kill, |
| #endif |
| }; |
| |
| CPU_METHOD_OF_DECLARE(psci, &cpu_psci_ops); |
| #endif |