| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * 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. |
| */ |
| |
| #define pr_fmt(fmt) "PM: " fmt |
| |
| #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/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/swait.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_TO_IDLE] = "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_TO_IDLE] = "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_TO_IDLE; |
| suspend_state_t mem_sleep_default = PM_SUSPEND_MAX; |
| suspend_state_t pm_suspend_target_state; |
| EXPORT_SYMBOL_GPL(pm_suspend_target_state); |
| |
| 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_s2idle_ops *s2idle_ops; |
| static DECLARE_SWAIT_QUEUE_HEAD(s2idle_wait_head); |
| |
| enum s2idle_states __read_mostly s2idle_state; |
| static DEFINE_RAW_SPINLOCK(s2idle_lock); |
| |
| /** |
| * pm_suspend_via_s2idle - Check if suspend-to-idle is the default suspend. |
| * |
| * Return 'true' if suspend-to-idle has been selected as the default system |
| * suspend method. |
| */ |
| bool pm_suspend_via_s2idle(void) |
| { |
| return mem_sleep_current == PM_SUSPEND_TO_IDLE; |
| } |
| EXPORT_SYMBOL_GPL(pm_suspend_via_s2idle); |
| |
| void s2idle_set_ops(const struct platform_s2idle_ops *ops) |
| { |
| lock_system_sleep(); |
| s2idle_ops = ops; |
| unlock_system_sleep(); |
| } |
| |
| static void s2idle_begin(void) |
| { |
| s2idle_state = S2IDLE_STATE_NONE; |
| } |
| |
| static void s2idle_enter(void) |
| { |
| trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, true); |
| |
| raw_spin_lock_irq(&s2idle_lock); |
| if (pm_wakeup_pending()) |
| goto out; |
| |
| s2idle_state = S2IDLE_STATE_ENTER; |
| raw_spin_unlock_irq(&s2idle_lock); |
| |
| get_online_cpus(); |
| cpuidle_resume(); |
| |
| /* Push all the CPUs into the idle loop. */ |
| wake_up_all_idle_cpus(); |
| /* Make the current CPU wait so it can enter the idle loop too. */ |
| swait_event_exclusive(s2idle_wait_head, |
| s2idle_state == S2IDLE_STATE_WAKE); |
| |
| cpuidle_pause(); |
| put_online_cpus(); |
| |
| raw_spin_lock_irq(&s2idle_lock); |
| |
| out: |
| s2idle_state = S2IDLE_STATE_NONE; |
| raw_spin_unlock_irq(&s2idle_lock); |
| |
| trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, false); |
| } |
| |
| static void s2idle_loop(void) |
| { |
| pm_pr_dbg("suspend-to-idle\n"); |
| |
| for (;;) { |
| int error; |
| |
| dpm_noirq_begin(); |
| |
| /* |
| * Suspend-to-idle equals |
| * frozen processes + suspended devices + idle processors. |
| * Thus s2idle_enter() should be called right after |
| * all devices have been suspended. |
| * |
| * Wakeups during the noirq suspend of devices may be spurious, |
| * so prevent them from terminating the loop right away. |
| */ |
| error = dpm_noirq_suspend_devices(PMSG_SUSPEND); |
| if (!error) |
| s2idle_enter(); |
| else if (error == -EBUSY && pm_wakeup_pending()) |
| error = 0; |
| |
| if (!error && s2idle_ops && s2idle_ops->wake) |
| s2idle_ops->wake(); |
| |
| dpm_noirq_resume_devices(PMSG_RESUME); |
| |
| dpm_noirq_end(); |
| |
| if (error) |
| break; |
| |
| if (s2idle_ops && s2idle_ops->sync) |
| s2idle_ops->sync(); |
| |
| if (pm_wakeup_pending()) |
| break; |
| |
| pm_wakeup_clear(false); |
| } |
| |
| pm_pr_dbg("resume from suspend-to-idle\n"); |
| } |
| |
| void s2idle_wake(void) |
| { |
| unsigned long flags; |
| |
| raw_spin_lock_irqsave(&s2idle_lock, flags); |
| if (s2idle_state > S2IDLE_STATE_NONE) { |
| s2idle_state = S2IDLE_STATE_WAKE; |
| swake_up_one(&s2idle_wait_head); |
| } |
| raw_spin_unlock_irqrestore(&s2idle_lock, flags); |
| } |
| EXPORT_SYMBOL_GPL(s2idle_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_TO_IDLE] = pm_labels[PM_SUSPEND_TO_IDLE]; |
| /* |
| * Suspend-to-idle should be supported even without any suspend_ops, |
| * initialize mem_sleep_states[] accordingly here. |
| */ |
| mem_sleep_states[PM_SUSPEND_TO_IDLE] = mem_sleep_labels[PM_SUSPEND_TO_IDLE]; |
| } |
| |
| static int __init mem_sleep_default_setup(char *str) |
| { |
| suspend_state_t state; |
| |
| for (state = PM_SUSPEND_TO_IDLE; 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_TO_IDLE || (suspend_ops && suspend_ops->enter); |
| } |
| |
| static int platform_suspend_prepare(suspend_state_t state) |
| { |
| return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare ? |
| suspend_ops->prepare() : 0; |
| } |
| |
| static int platform_suspend_prepare_late(suspend_state_t state) |
| { |
| return state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->prepare ? |
| s2idle_ops->prepare() : 0; |
| } |
| |
| static int platform_suspend_prepare_noirq(suspend_state_t state) |
| { |
| return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare_late ? |
| suspend_ops->prepare_late() : 0; |
| } |
| |
| static void platform_resume_noirq(suspend_state_t state) |
| { |
| if (state != PM_SUSPEND_TO_IDLE && suspend_ops->wake) |
| suspend_ops->wake(); |
| } |
| |
| static void platform_resume_early(suspend_state_t state) |
| { |
| if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->restore) |
| s2idle_ops->restore(); |
| } |
| |
| static void platform_resume_finish(suspend_state_t state) |
| { |
| if (state != PM_SUSPEND_TO_IDLE && suspend_ops->finish) |
| suspend_ops->finish(); |
| } |
| |
| static int platform_suspend_begin(suspend_state_t state) |
| { |
| if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->begin) |
| return s2idle_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_TO_IDLE && s2idle_ops && s2idle_ops->end) |
| s2idle_ops->end(); |
| else if (suspend_ops && suspend_ops->end) |
| suspend_ops->end(); |
| } |
| |
| static void platform_recover(suspend_state_t state) |
| { |
| if (state != PM_SUSPEND_TO_IDLE && suspend_ops->recover) |
| suspend_ops->recover(); |
| } |
| |
| static bool platform_suspend_again(suspend_state_t state) |
| { |
| return state != PM_SUSPEND_TO_IDLE && 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("late suspend of devices failed\n"); |
| goto Platform_finish; |
| } |
| error = platform_suspend_prepare_late(state); |
| if (error) |
| goto Devices_early_resume; |
| |
| if (state == PM_SUSPEND_TO_IDLE && pm_test_level != TEST_PLATFORM) { |
| s2idle_loop(); |
| goto Platform_early_resume; |
| } |
| |
| error = dpm_suspend_noirq(PMSG_SUSPEND); |
| if (error) { |
| pr_err("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; |
| |
| error = suspend_disable_secondary_cpus(); |
| if (error || suspend_test(TEST_CPUS)) |
| goto Enable_cpus; |
| |
| arch_suspend_disable_irqs(); |
| BUG_ON(!irqs_disabled()); |
| |
| system_state = SYSTEM_SUSPEND; |
| |
| 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); |
| } else if (*wakeup) { |
| error = -EBUSY; |
| } |
| syscore_resume(); |
| } |
| |
| system_state = SYSTEM_RUNNING; |
| |
| arch_suspend_enable_irqs(); |
| BUG_ON(irqs_disabled()); |
| |
| Enable_cpus: |
| suspend_enable_secondary_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; |
| |
| pm_suspend_target_state = state; |
| |
| error = platform_suspend_begin(state); |
| if (error) |
| goto Close; |
| |
| suspend_console(); |
| suspend_test_start(); |
| error = dpm_suspend_start(PMSG_SUSPEND); |
| if (error) { |
| pr_err("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); |
| pm_suspend_target_state = PM_SUSPEND_ON; |
| 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_TO_IDLE) { |
| #ifdef CONFIG_PM_DEBUG |
| if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) { |
| pr_warn("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(&system_transition_mutex)) |
| return -EBUSY; |
| |
| if (state == PM_SUSPEND_TO_IDLE) |
| s2idle_begin(); |
| |
| if (!IS_ENABLED(CONFIG_SUSPEND_SKIP_SYNC)) { |
| trace_suspend_resume(TPS("sync_filesystems"), 0, true); |
| ksys_sync_helper(); |
| trace_suspend_resume(TPS("sync_filesystems"), 0, false); |
| } |
| |
| pm_pr_dbg("Preparing system for sleep (%s)\n", mem_sleep_labels[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); |
| pm_pr_dbg("Suspending system (%s)\n", mem_sleep_labels[state]); |
| pm_restrict_gfp_mask(); |
| error = suspend_devices_and_enter(state); |
| pm_restore_gfp_mask(); |
| |
| Finish: |
| events_check_enabled = false; |
| pm_pr_dbg("Finishing wakeup.\n"); |
| suspend_finish(); |
| Unlock: |
| mutex_unlock(&system_transition_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; |
| |
| pr_info("suspend entry (%s)\n", mem_sleep_labels[state]); |
| error = enter_state(state); |
| if (error) { |
| suspend_stats.fail++; |
| dpm_save_failed_errno(error); |
| } else { |
| suspend_stats.success++; |
| } |
| pr_info("suspend exit\n"); |
| return error; |
| } |
| EXPORT_SYMBOL(pm_suspend); |