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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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#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 <linux/fs.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_default_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_default_s2idle(void){ return mem_sleep_current == PM_SUSPEND_TO_IDLE;}EXPORT_SYMBOL_GPL(pm_suspend_default_s2idle);
void s2idle_set_ops(const struct platform_s2idle_ops *ops){ unsigned int sleep_flags;
sleep_flags = lock_system_sleep(); s2idle_ops = ops; unlock_system_sleep(sleep_flags);}
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);
/* * The correctness of the code below depends on the number of online * CPUs being stable, but CPUs cannot be taken offline or put online * while it is running. * * The s2idle_lock must be acquired before the pending wakeup check to * prevent pm_system_wakeup() from running as a whole between that check * and the subsequent s2idle_state update in which case a wakeup event * would get lost. */ raw_spin_lock_irq(&s2idle_lock); if (pm_wakeup_pending()) goto out;
s2idle_state = S2IDLE_STATE_ENTER; raw_spin_unlock_irq(&s2idle_lock);
/* 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);
/* * Kick all CPUs to ensure that they resume their timers and restore * consistent system state. */ wake_up_all_idle_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");
/* * 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 try * to avoid them upfront. */ for (;;) { if (s2idle_ops && s2idle_ops->wake) { if (s2idle_ops->wake()) break; } else if (pm_wakeup_pending()) { break; }
if (s2idle_ops && s2idle_ops->check) s2idle_ops->check();
s2idle_enter(); }
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){ /* * The PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states require low-level * support and need to be valid to the low-level implementation. * * No ->valid() or ->enter() callback implies that none are valid. */ return suspend_ops && suspend_ops->valid && suspend_ops->valid(state) && suspend_ops->enter;}
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; mem_sleep_current = 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){ unsigned int sleep_flags;
sleep_flags = 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(sleep_flags);}EXPORT_SYMBOL_GPL(suspend_set_ops);
/** * suspend_valid_only_mem - Generic memory-only valid callback. * @state: Target system sleep state. * * 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 || (valid_state(state) && !cxl_mem_active());}
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){ if (state == PM_SUSPEND_TO_IDLE) return s2idle_ops && s2idle_ops->prepare_late ? s2idle_ops->prepare_late() : 0;
return suspend_ops->prepare_late ? suspend_ops->prepare_late() : 0;}
static void platform_resume_noirq(suspend_state_t state){ if (state == PM_SUSPEND_TO_IDLE) { if (s2idle_ops && s2idle_ops->restore_early) s2idle_ops->restore_early(); } else if (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_DEBUGstatic 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 int i;
if (pm_test_level == level) { pr_info("suspend debug: Waiting for %d second(s).\n", pm_test_delay); for (i = 0; i < pm_test_delay && !pm_wakeup_pending(); i++) { if (level > TEST_CORE) msleep(1000); else mdelay(1000); } return 1; }#endif /* !CONFIG_PM_DEBUG */ return 0;}
/** * suspend_prepare - Prepare for entering system sleep state. * @state: Target 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;
if (!sleep_state_supported(state)) return -EPERM;
pm_prepare_console();
error = pm_notifier_call_chain_robust(PM_SUSPEND_PREPARE, PM_POST_SUSPEND); if (error) goto Restore;
filesystems_freeze(filesystem_freeze_enabled); trace_suspend_resume(TPS("freeze_processes"), 0, true); error = suspend_freeze_processes(); trace_suspend_resume(TPS("freeze_processes"), 0, false); if (!error) return 0;
dpm_save_failed_step(SUSPEND_FREEZE); filesystems_thaw(); pm_notifier_call_chain(PM_POST_SUSPEND); Restore: 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;
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;
if (state == PM_SUSPEND_TO_IDLE) { s2idle_loop(); goto Platform_wake; }
error = pm_sleep_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: pm_sleep_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;
if (state == PM_SUSPEND_TO_IDLE) pm_set_suspend_no_platform();
error = platform_suspend_begin(state); if (error) goto Close;
console_suspend_all(); 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("console_resume_all"), state, true); console_resume_all(); trace_suspend_resume(TPS("console_resume_all"), 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(); filesystems_thaw(); 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 (sync_on_suspend_enabled) { trace_suspend_resume(TPS("sync_filesystems"), 0, true);
error = pm_sleep_fs_sync(); if (error) goto Unlock;
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]); error = suspend_devices_and_enter(state);
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); dpm_save_errno(error); pr_info("suspend exit\n"); return error;}EXPORT_SYMBOL(pm_suspend);