/* * kernel/power/suspend.c - Suspend to RAM and standby functionality. * * Copyright (c) 2003 Patrick Mochel * Copyright (c) 2003 Open Source Development Lab * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc. * * This file is released under the GPLv2. */ #include <linux/string.h> #include <linux/delay.h> #include <linux/errno.h> #include <linux/init.h> #include <linux/console.h> #include <linux/cpu.h> #include <linux/cpuidle.h> #include <linux/syscalls.h> #include <linux/gfp.h> #include <linux/io.h> #include <linux/kernel.h> #include <linux/list.h> #include <linux/mm.h> #include <linux/slab.h> #include <linux/export.h> #include <linux/suspend.h> #include <linux/syscore_ops.h> #include <linux/ftrace.h> #include <trace/events/power.h> #include <linux/compiler.h> #include <linux/moduleparam.h> #include "power.h" const char * const pm_labels[] = { [PM_SUSPEND_FREEZE] = "freeze", [PM_SUSPEND_STANDBY] = "standby", [PM_SUSPEND_MEM] = "mem", }; const char *pm_states[PM_SUSPEND_MAX]; static const char * const mem_sleep_labels[] = { [PM_SUSPEND_FREEZE] = "s2idle", [PM_SUSPEND_STANDBY] = "shallow", [PM_SUSPEND_MEM] = "deep", }; const char *mem_sleep_states[PM_SUSPEND_MAX]; suspend_state_t mem_sleep_current = PM_SUSPEND_FREEZE; static suspend_state_t mem_sleep_default = PM_SUSPEND_MEM; unsigned int pm_suspend_global_flags; EXPORT_SYMBOL_GPL(pm_suspend_global_flags); static const struct platform_suspend_ops *suspend_ops; static const struct platform_freeze_ops *freeze_ops; static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head); enum freeze_state __read_mostly suspend_freeze_state; static DEFINE_SPINLOCK(suspend_freeze_lock); void freeze_set_ops(const struct platform_freeze_ops *ops) { lock_system_sleep(); freeze_ops = ops; unlock_system_sleep(); } static void freeze_begin(void) { suspend_freeze_state = FREEZE_STATE_NONE; } static void freeze_enter(void) { spin_lock_irq(&suspend_freeze_lock); if (pm_wakeup_pending()) goto out; suspend_freeze_state = FREEZE_STATE_ENTER; spin_unlock_irq(&suspend_freeze_lock); get_online_cpus(); cpuidle_resume(); /* Push all the CPUs into the idle loop. */ wake_up_all_idle_cpus(); pr_debug("PM: suspend-to-idle\n"); /* Make the current CPU wait so it can enter the idle loop too. */ wait_event(suspend_freeze_wait_head, suspend_freeze_state == FREEZE_STATE_WAKE); pr_debug("PM: resume from suspend-to-idle\n"); cpuidle_pause(); put_online_cpus(); spin_lock_irq(&suspend_freeze_lock); out: suspend_freeze_state = FREEZE_STATE_NONE; spin_unlock_irq(&suspend_freeze_lock); } void freeze_wake(void) { unsigned long flags; spin_lock_irqsave(&suspend_freeze_lock, flags); if (suspend_freeze_state > FREEZE_STATE_NONE) { suspend_freeze_state = FREEZE_STATE_WAKE; wake_up(&suspend_freeze_wait_head); } spin_unlock_irqrestore(&suspend_freeze_lock, flags); } EXPORT_SYMBOL_GPL(freeze_wake); static bool valid_state(suspend_state_t state) { /* * PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level * support and need to be valid to the low level * implementation, no valid callback implies that none are valid. */ return suspend_ops && suspend_ops->valid && suspend_ops->valid(state); } void __init pm_states_init(void) { /* "mem" and "freeze" are always present in /sys/power/state. */ pm_states[PM_SUSPEND_MEM] = pm_labels[PM_SUSPEND_MEM]; pm_states[PM_SUSPEND_FREEZE] = pm_labels[PM_SUSPEND_FREEZE]; /* * Suspend-to-idle should be supported even without any suspend_ops, * initialize mem_sleep_states[] accordingly here. */ mem_sleep_states[PM_SUSPEND_FREEZE] = mem_sleep_labels[PM_SUSPEND_FREEZE]; } static int __init mem_sleep_default_setup(char *str) { suspend_state_t state; for (state = PM_SUSPEND_FREEZE; state <= PM_SUSPEND_MEM; state++) if (mem_sleep_labels[state] && !strcmp(str, mem_sleep_labels[state])) { mem_sleep_default = state; break; } return 1; } __setup("mem_sleep_default=", mem_sleep_default_setup); /** * suspend_set_ops - Set the global suspend method table. * @ops: Suspend operations to use. */ void suspend_set_ops(const struct platform_suspend_ops *ops) { lock_system_sleep(); suspend_ops = ops; if (valid_state(PM_SUSPEND_STANDBY)) { mem_sleep_states[PM_SUSPEND_STANDBY] = mem_sleep_labels[PM_SUSPEND_STANDBY]; pm_states[PM_SUSPEND_STANDBY] = pm_labels[PM_SUSPEND_STANDBY]; if (mem_sleep_default == PM_SUSPEND_STANDBY) mem_sleep_current = PM_SUSPEND_STANDBY; } if (valid_state(PM_SUSPEND_MEM)) { mem_sleep_states[PM_SUSPEND_MEM] = mem_sleep_labels[PM_SUSPEND_MEM]; if (mem_sleep_default == PM_SUSPEND_MEM) mem_sleep_current = PM_SUSPEND_MEM; } unlock_system_sleep(); } EXPORT_SYMBOL_GPL(suspend_set_ops); /** * suspend_valid_only_mem - Generic memory-only valid callback. * * Platform drivers that implement mem suspend only and only need to check for * that in their .valid() callback can use this instead of rolling their own * .valid() callback. */ int suspend_valid_only_mem(suspend_state_t state) { return state == PM_SUSPEND_MEM; } EXPORT_SYMBOL_GPL(suspend_valid_only_mem); static bool sleep_state_supported(suspend_state_t state) { return state == PM_SUSPEND_FREEZE || (suspend_ops && suspend_ops->enter); } static int platform_suspend_prepare(suspend_state_t state) { return state != PM_SUSPEND_FREEZE && suspend_ops->prepare ? suspend_ops->prepare() : 0; } static int platform_suspend_prepare_late(suspend_state_t state) { return state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->prepare ? freeze_ops->prepare() : 0; } static int platform_suspend_prepare_noirq(suspend_state_t state) { return state != PM_SUSPEND_FREEZE && suspend_ops->prepare_late ? suspend_ops->prepare_late() : 0; } static void platform_resume_noirq(suspend_state_t state) { if (state != PM_SUSPEND_FREEZE && suspend_ops->wake) suspend_ops->wake(); } static void platform_resume_early(suspend_state_t state) { if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->restore) freeze_ops->restore(); } static void platform_resume_finish(suspend_state_t state) { if (state != PM_SUSPEND_FREEZE && suspend_ops->finish) suspend_ops->finish(); } static int platform_suspend_begin(suspend_state_t state) { if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->begin) return freeze_ops->begin(); else if (suspend_ops && suspend_ops->begin) return suspend_ops->begin(state); else return 0; } static void platform_resume_end(suspend_state_t state) { if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->end) freeze_ops->end(); else if (suspend_ops && suspend_ops->end) suspend_ops->end(); } static void platform_recover(suspend_state_t state) { if (state != PM_SUSPEND_FREEZE && suspend_ops->recover) suspend_ops->recover(); } static bool platform_suspend_again(suspend_state_t state) { return state != PM_SUSPEND_FREEZE && suspend_ops->suspend_again ? suspend_ops->suspend_again() : false; } #ifdef CONFIG_PM_DEBUG static unsigned int pm_test_delay = 5; module_param(pm_test_delay, uint, 0644); MODULE_PARM_DESC(pm_test_delay, "Number of seconds to wait before resuming from suspend test"); #endif static int suspend_test(int level) { #ifdef CONFIG_PM_DEBUG if (pm_test_level == level) { pr_info("suspend debug: Waiting for %d second(s).\n", pm_test_delay); mdelay(pm_test_delay * 1000); return 1; } #endif /* !CONFIG_PM_DEBUG */ return 0; } /** * suspend_prepare - Prepare for entering system sleep state. * * Common code run for every system sleep state that can be entered (except for * hibernation). Run suspend notifiers, allocate the "suspend" console and * freeze processes. */ static int suspend_prepare(suspend_state_t state) { int error, nr_calls = 0; if (!sleep_state_supported(state)) return -EPERM; pm_prepare_console(); error = __pm_notifier_call_chain(PM_SUSPEND_PREPARE, -1, &nr_calls); if (error) { nr_calls--; goto Finish; } trace_suspend_resume(TPS("freeze_processes"), 0, true); error = suspend_freeze_processes(); trace_suspend_resume(TPS("freeze_processes"), 0, false); if (!error) return 0; suspend_stats.failed_freeze++; dpm_save_failed_step(SUSPEND_FREEZE); Finish: __pm_notifier_call_chain(PM_POST_SUSPEND, nr_calls, NULL); pm_restore_console(); return error; } /* default implementation */ void __weak arch_suspend_disable_irqs(void) { local_irq_disable(); } /* default implementation */ void __weak arch_suspend_enable_irqs(void) { local_irq_enable(); } /** * suspend_enter - Make the system enter the given sleep state. * @state: System sleep state to enter. * @wakeup: Returns information that the sleep state should not be re-entered. * * This function should be called after devices have been suspended. */ static int suspend_enter(suspend_state_t state, bool *wakeup) { int error; error = platform_suspend_prepare(state); if (error) goto Platform_finish; error = dpm_suspend_late(PMSG_SUSPEND); if (error) { pr_err("PM: late suspend of devices failed\n"); goto Platform_finish; } error = platform_suspend_prepare_late(state); if (error) goto Devices_early_resume; error = dpm_suspend_noirq(PMSG_SUSPEND); if (error) { pr_err("PM: noirq suspend of devices failed\n"); goto Platform_early_resume; } error = platform_suspend_prepare_noirq(state); if (error) goto Platform_wake; if (suspend_test(TEST_PLATFORM)) goto Platform_wake; /* * PM_SUSPEND_FREEZE equals * frozen processes + suspended devices + idle processors. * Thus we should invoke freeze_enter() soon after * all the devices are suspended. */ if (state == PM_SUSPEND_FREEZE) { trace_suspend_resume(TPS("machine_suspend"), state, true); freeze_enter(); trace_suspend_resume(TPS("machine_suspend"), state, false); goto Platform_wake; } error = disable_nonboot_cpus(); if (error || suspend_test(TEST_CPUS)) goto Enable_cpus; arch_suspend_disable_irqs(); BUG_ON(!irqs_disabled()); error = syscore_suspend(); if (!error) { *wakeup = pm_wakeup_pending(); if (!(suspend_test(TEST_CORE) || *wakeup)) { trace_suspend_resume(TPS("machine_suspend"), state, true); error = suspend_ops->enter(state); trace_suspend_resume(TPS("machine_suspend"), state, false); events_check_enabled = false; } else if (*wakeup) { error = -EBUSY; } syscore_resume(); } arch_suspend_enable_irqs(); BUG_ON(irqs_disabled()); Enable_cpus: enable_nonboot_cpus(); Platform_wake: platform_resume_noirq(state); dpm_resume_noirq(PMSG_RESUME); Platform_early_resume: platform_resume_early(state); Devices_early_resume: dpm_resume_early(PMSG_RESUME); Platform_finish: platform_resume_finish(state); return error; } /** * suspend_devices_and_enter - Suspend devices and enter system sleep state. * @state: System sleep state to enter. */ int suspend_devices_and_enter(suspend_state_t state) { int error; bool wakeup = false; if (!sleep_state_supported(state)) return -ENOSYS; error = platform_suspend_begin(state); if (error) goto Close; suspend_console(); suspend_test_start(); error = dpm_suspend_start(PMSG_SUSPEND); if (error) { pr_err("PM: Some devices failed to suspend, or early wake event detected\n"); goto Recover_platform; } suspend_test_finish("suspend devices"); if (suspend_test(TEST_DEVICES)) goto Recover_platform; do { error = suspend_enter(state, &wakeup); } while (!error && !wakeup && platform_suspend_again(state)); Resume_devices: suspend_test_start(); dpm_resume_end(PMSG_RESUME); suspend_test_finish("resume devices"); trace_suspend_resume(TPS("resume_console"), state, true); resume_console(); trace_suspend_resume(TPS("resume_console"), state, false); Close: platform_resume_end(state); return error; Recover_platform: platform_recover(state); goto Resume_devices; } /** * suspend_finish - Clean up before finishing the suspend sequence. * * Call platform code to clean up, restart processes, and free the console that * we've allocated. This routine is not called for hibernation. */ static void suspend_finish(void) { suspend_thaw_processes(); pm_notifier_call_chain(PM_POST_SUSPEND); pm_restore_console(); } /** * enter_state - Do common work needed to enter system sleep state. * @state: System sleep state to enter. * * Make sure that no one else is trying to put the system into a sleep state. * Fail if that's not the case. Otherwise, prepare for system suspend, make the * system enter the given sleep state and clean up after wakeup. */ static int enter_state(suspend_state_t state) { int error; trace_suspend_resume(TPS("suspend_enter"), state, true); if (state == PM_SUSPEND_FREEZE) { #ifdef CONFIG_PM_DEBUG if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) { pr_warn("PM: Unsupported test mode for suspend to idle, please choose none/freezer/devices/platform.\n"); return -EAGAIN; } #endif } else if (!valid_state(state)) { return -EINVAL; } if (!mutex_trylock(&pm_mutex)) return -EBUSY; if (state == PM_SUSPEND_FREEZE) freeze_begin(); #ifndef CONFIG_SUSPEND_SKIP_SYNC trace_suspend_resume(TPS("sync_filesystems"), 0, true); pr_info("PM: Syncing filesystems ... "); sys_sync(); pr_cont("done.\n"); trace_suspend_resume(TPS("sync_filesystems"), 0, false); #endif pr_debug("PM: Preparing system for sleep (%s)\n", pm_states[state]); pm_suspend_clear_flags(); error = suspend_prepare(state); if (error) goto Unlock; if (suspend_test(TEST_FREEZER)) goto Finish; trace_suspend_resume(TPS("suspend_enter"), state, false); pr_debug("PM: Suspending system (%s)\n", pm_states[state]); pm_restrict_gfp_mask(); error = suspend_devices_and_enter(state); pm_restore_gfp_mask(); Finish: pr_debug("PM: Finishing wakeup.\n"); suspend_finish(); Unlock: mutex_unlock(&pm_mutex); return error; } /** * pm_suspend - Externally visible function for suspending the system. * @state: System sleep state to enter. * * Check if the value of @state represents one of the supported states, * execute enter_state() and update system suspend statistics. */ int pm_suspend(suspend_state_t state) { int error; if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX) return -EINVAL; error = enter_state(state); if (error) { suspend_stats.fail++; dpm_save_failed_errno(error); } else { suspend_stats.success++; } return error; } EXPORT_SYMBOL(pm_suspend);