[mirror_ubuntu-bionic-kernel.git] / kernel / power / suspend.c

/*
 * 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.
 */

#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/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_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_WAIT_QUEUE_HEAD(s2idle_wait_head);

enum s2idle_states __read_mostly s2idle_state;
static DEFINE_RAW_SPINLOCK(s2idle_lock);

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. */
	wait_event(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;
		wake_up(&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 = 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);
		} 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;

	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(&pm_mutex))
		return -EBUSY;

	if (state == PM_SUSPEND_TO_IDLE)
		s2idle_begin();

#ifndef CONFIG_SUSPEND_SKIP_SYNC
	trace_suspend_resume(TPS("sync_filesystems"), 0, true);
	pr_info("Syncing filesystems ... ");
	sys_sync();
	pr_cont("done.\n");
	trace_suspend_resume(TPS("sync_filesystems"), 0, false);
#endif

	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(&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;

	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);
Commit	Line	Data
a9d70523 RW	1	/*
	2	* kernel/power/suspend.c - Suspend to RAM and standby functionality.
	3	*
	4	* Copyright (c) 2003 Patrick Mochel
	5	* Copyright (c) 2003 Open Source Development Lab
	6	* Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
	7	*
	8	* This file is released under the GPLv2.
	9	*/
	10
142bce74 RW	11	#define pr_fmt(fmt) "PM: " fmt
142bce74 RW	12
a9d70523 RW	13	#include <linux/string.h>
	14	#include <linux/delay.h>
	15	#include <linux/errno.h>
	16	#include <linux/init.h>
	17	#include <linux/console.h>
	18	#include <linux/cpu.h>
f3f12532	19	#include <linux/cpuidle.h>
a9d70523	20	#include <linux/syscalls.h>
5a0e3ad6	21	#include <linux/gfp.h>
dd4c4f17 MG	22	#include <linux/io.h>
	23	#include <linux/kernel.h>
	24	#include <linux/list.h>
	25	#include <linux/mm.h>
	26	#include <linux/slab.h>
6e5fdeed	27	#include <linux/export.h>
dd4c4f17	28	#include <linux/suspend.h>
40dc166c	29	#include <linux/syscore_ops.h>
443772d4	30	#include <linux/ftrace.h>
938cfed1	31	#include <trace/events/power.h>
52f5684c	32	#include <linux/compiler.h>
1d4a9c17	33	#include <linux/moduleparam.h>
a9d70523 RW	34
	35	#include "power.h"
	36
406e7938	37	const char * const pm_labels[] = {
690cbb90	38	[PM_SUSPEND_TO_IDLE] = "freeze",
406e7938 RW	39	[PM_SUSPEND_STANDBY] = "standby",
	40	[PM_SUSPEND_MEM] = "mem",
	41	};
d431cbc5	42	const char *pm_states[PM_SUSPEND_MAX];
406e7938	43	static const char * const mem_sleep_labels[] = {
690cbb90	44	[PM_SUSPEND_TO_IDLE] = "s2idle",
406e7938 RW	45	[PM_SUSPEND_STANDBY] = "shallow",
	46	[PM_SUSPEND_MEM] = "deep",
	47	};
	48	const char *mem_sleep_states[PM_SUSPEND_MAX];
	49
690cbb90	50	suspend_state_t mem_sleep_current = PM_SUSPEND_TO_IDLE;
e870c6c8	51	suspend_state_t mem_sleep_default = PM_SUSPEND_MAX;
bd8c9ba3 FF	52	suspend_state_t pm_suspend_target_state;
bd8c9ba3 FF	53	EXPORT_SYMBOL_GPL(pm_suspend_target_state);
a9d70523	54
ef25ba04 RW	55	unsigned int pm_suspend_global_flags;
	56	EXPORT_SYMBOL_GPL(pm_suspend_global_flags);
	57
2f55ac07	58	static const struct platform_suspend_ops *suspend_ops;
23d5855f	59	static const struct platform_s2idle_ops *s2idle_ops;
f02f4f9d	60	static DECLARE_WAIT_QUEUE_HEAD(s2idle_wait_head);
38106313	61
f02f4f9d	62	enum s2idle_states __read_mostly s2idle_state;
bf2f7179	63	static DEFINE_RAW_SPINLOCK(s2idle_lock);
7e73c5ae	64
6e8b8645 DD	65	bool pm_suspend_via_s2idle(void)
	66	{
	67	return mem_sleep_current == PM_SUSPEND_TO_IDLE;
	68	}
	69	EXPORT_SYMBOL_GPL(pm_suspend_via_s2idle);
	70
23d5855f	71	void s2idle_set_ops(const struct platform_s2idle_ops *ops)
1f0b6386 RW	72	{
1f0b6386 RW	73	lock_system_sleep();
23d5855f	74	s2idle_ops = ops;
1f0b6386 RW	75	unlock_system_sleep();
	76	}
	77
f02f4f9d	78	static void s2idle_begin(void)
7e73c5ae	79	{
f02f4f9d	80	s2idle_state = S2IDLE_STATE_NONE;
7e73c5ae ZR	81	}
7e73c5ae ZR	82
f02f4f9d	83	static void s2idle_enter(void)
7e73c5ae	84	{
690cbb90	85	trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, true);
33e4f80e	86
bf2f7179	87	raw_spin_lock_irq(&s2idle_lock);
38106313 RW	88	if (pm_wakeup_pending())
	89	goto out;
	90
f02f4f9d	91	s2idle_state = S2IDLE_STATE_ENTER;
bf2f7179	92	raw_spin_unlock_irq(&s2idle_lock);
38106313 RW	93
38106313 RW	94	get_online_cpus();
f3f12532	95	cpuidle_resume();
38106313 RW	96
	97	/* Push all the CPUs into the idle loop. */
	98	wake_up_all_idle_cpus();
38106313	99	/* Make the current CPU wait so it can enter the idle loop too. */
f02f4f9d RW	100	wait_event(s2idle_wait_head,
f02f4f9d RW	101	s2idle_state == S2IDLE_STATE_WAKE);
38106313	102
f3f12532	103	cpuidle_pause();
38106313 RW	104	put_online_cpus();
38106313 RW	105
bf2f7179	106	raw_spin_lock_irq(&s2idle_lock);
38106313 RW	107
38106313 RW	108	out:
f02f4f9d	109	s2idle_state = S2IDLE_STATE_NONE;
bf2f7179	110	raw_spin_unlock_irq(&s2idle_lock);
33e4f80e	111
690cbb90	112	trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, false);
33e4f80e RW	113	}
	114
	115	static void s2idle_loop(void)
	116	{
8d8b2441	117	pm_pr_dbg("suspend-to-idle\n");
33e4f80e	118
9a3ebe35 RW	119	for (;;) {
	120	int error;
	121
	122	dpm_noirq_begin();
	123
8e6bcd9f RW	124	/*
	125	* Suspend-to-idle equals
	126	* frozen processes + suspended devices + idle processors.
f02f4f9d	127	* Thus s2idle_enter() should be called right after
8e6bcd9f	128	* all devices have been suspended.
87cbde8d RW	129	*
	130	* Wakeups during the noirq suspend of devices may be spurious,
	131	* so prevent them from terminating the loop right away.
8e6bcd9f	132	*/
9a3ebe35 RW	133	error = dpm_noirq_suspend_devices(PMSG_SUSPEND);
9a3ebe35 RW	134	if (!error)
f02f4f9d	135	s2idle_enter();
87cbde8d RW	136	else if (error == -EBUSY && pm_wakeup_pending())
87cbde8d RW	137	error = 0;
9a3ebe35	138
87cbde8d	139	if (!error && s2idle_ops && s2idle_ops->wake)
23d5855f	140	s2idle_ops->wake();
33e4f80e	141
87cbde8d RW	142	dpm_noirq_resume_devices(PMSG_RESUME);
87cbde8d RW	143
9a3ebe35 RW	144	dpm_noirq_end();
9a3ebe35 RW	145
87cbde8d RW	146	if (error)
	147	break;
	148
23d5855f RW	149	if (s2idle_ops && s2idle_ops->sync)
23d5855f RW	150	s2idle_ops->sync();
33e4f80e RW	151
	152	if (pm_wakeup_pending())
	153	break;
	154
	155	pm_wakeup_clear(false);
8e6bcd9f	156	}
33e4f80e	157
8d8b2441	158	pm_pr_dbg("resume from suspend-to-idle\n");
7e73c5ae ZR	159	}
7e73c5ae ZR	160
f02f4f9d	161	void s2idle_wake(void)
7e73c5ae	162	{
38106313 RW	163	unsigned long flags;
38106313 RW	164
bf2f7179	165	raw_spin_lock_irqsave(&s2idle_lock, flags);
f02f4f9d RW	166	if (s2idle_state > S2IDLE_STATE_NONE) {
	167	s2idle_state = S2IDLE_STATE_WAKE;
	168	wake_up(&s2idle_wait_head);
38106313	169	}
bf2f7179	170	raw_spin_unlock_irqrestore(&s2idle_lock, flags);
7e73c5ae	171	}
f02f4f9d	172	EXPORT_SYMBOL_GPL(s2idle_wake);
7e73c5ae	173
43e8317b RW	174	static bool valid_state(suspend_state_t state)
	175	{
	176	/*
	177	* PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
	178	* support and need to be valid to the low level
	179	* implementation, no valid callback implies that none are valid.
	180	*/
	181	return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
	182	}
	183
fa7fd6fa SH	184	void __init pm_states_init(void)
fa7fd6fa SH	185	{
406e7938 RW	186	/* "mem" and "freeze" are always present in /sys/power/state. */
406e7938 RW	187	pm_states[PM_SUSPEND_MEM] = pm_labels[PM_SUSPEND_MEM];
690cbb90	188	pm_states[PM_SUSPEND_TO_IDLE] = pm_labels[PM_SUSPEND_TO_IDLE];
fa7fd6fa	189	/*
406e7938 RW	190	* Suspend-to-idle should be supported even without any suspend_ops,
406e7938 RW	191	* initialize mem_sleep_states[] accordingly here.
fa7fd6fa	192	*/
690cbb90	193	mem_sleep_states[PM_SUSPEND_TO_IDLE] = mem_sleep_labels[PM_SUSPEND_TO_IDLE];
fa7fd6fa SH	194	}
fa7fd6fa SH	195
406e7938	196	static int __init mem_sleep_default_setup(char *str)
0399d4db	197	{
406e7938 RW	198	suspend_state_t state;
406e7938 RW	199
690cbb90	200	for (state = PM_SUSPEND_TO_IDLE; state <= PM_SUSPEND_MEM; state++)
406e7938 RW	201	if (mem_sleep_labels[state] &&
	202	!strcmp(str, mem_sleep_labels[state])) {
	203	mem_sleep_default = state;
	204	break;
	205	}
	206
0399d4db RW	207	return 1;
0399d4db RW	208	}
406e7938	209	__setup("mem_sleep_default=", mem_sleep_default_setup);
0399d4db	210
a9d70523	211	/**
55ae4519 RW	212	* suspend_set_ops - Set the global suspend method table.
55ae4519 RW	213	* @ops: Suspend operations to use.
a9d70523	214	*/
2f55ac07	215	void suspend_set_ops(const struct platform_suspend_ops *ops)
a9d70523	216	{
bcda53fa	217	lock_system_sleep();
43e8317b	218
a9d70523	219	suspend_ops = ops;
0399d4db	220
406e7938 RW	221	if (valid_state(PM_SUSPEND_STANDBY)) {
	222	mem_sleep_states[PM_SUSPEND_STANDBY] = mem_sleep_labels[PM_SUSPEND_STANDBY];
	223	pm_states[PM_SUSPEND_STANDBY] = pm_labels[PM_SUSPEND_STANDBY];
	224	if (mem_sleep_default == PM_SUSPEND_STANDBY)
	225	mem_sleep_current = PM_SUSPEND_STANDBY;
	226	}
	227	if (valid_state(PM_SUSPEND_MEM)) {
	228	mem_sleep_states[PM_SUSPEND_MEM] = mem_sleep_labels[PM_SUSPEND_MEM];
e870c6c8	229	if (mem_sleep_default >= PM_SUSPEND_MEM)
406e7938 RW	230	mem_sleep_current = PM_SUSPEND_MEM;
406e7938 RW	231	}
43e8317b	232
bcda53fa	233	unlock_system_sleep();
a9d70523	234	}
a5e4fd87	235	EXPORT_SYMBOL_GPL(suspend_set_ops);
a9d70523	236
a9d70523	237	/**
55ae4519	238	* suspend_valid_only_mem - Generic memory-only valid callback.
a9d70523	239	*
55ae4519 RW	240	* Platform drivers that implement mem suspend only and only need to check for
	241	* that in their .valid() callback can use this instead of rolling their own
	242	* .valid() callback.
a9d70523 RW	243	*/
	244	int suspend_valid_only_mem(suspend_state_t state)
	245	{
	246	return state == PM_SUSPEND_MEM;
	247	}
a5e4fd87	248	EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
a9d70523	249
8490fdf9 RW	250	static bool sleep_state_supported(suspend_state_t state)
8490fdf9 RW	251	{
690cbb90	252	return state == PM_SUSPEND_TO_IDLE \|\| (suspend_ops && suspend_ops->enter);
8490fdf9 RW	253	}
	254
	255	static int platform_suspend_prepare(suspend_state_t state)
	256	{
690cbb90	257	return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare ?
8490fdf9 RW	258	suspend_ops->prepare() : 0;
	259	}
	260
a8d46b9e RW	261	static int platform_suspend_prepare_late(suspend_state_t state)
a8d46b9e RW	262	{
23d5855f RW	263	return state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->prepare ?
23d5855f RW	264	s2idle_ops->prepare() : 0;
a8d46b9e RW	265	}
a8d46b9e RW	266
ebc3e41e	267	static int platform_suspend_prepare_noirq(suspend_state_t state)
8490fdf9	268	{
690cbb90	269	return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare_late ?
8490fdf9 RW	270	suspend_ops->prepare_late() : 0;
	271	}
	272
ebc3e41e	273	static void platform_resume_noirq(suspend_state_t state)
8490fdf9	274	{
690cbb90	275	if (state != PM_SUSPEND_TO_IDLE && suspend_ops->wake)
8490fdf9 RW	276	suspend_ops->wake();
	277	}
	278
a8d46b9e RW	279	static void platform_resume_early(suspend_state_t state)
a8d46b9e RW	280	{
23d5855f RW	281	if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->restore)
23d5855f RW	282	s2idle_ops->restore();
a8d46b9e RW	283	}
a8d46b9e RW	284
ebc3e41e	285	static void platform_resume_finish(suspend_state_t state)
8490fdf9	286	{
690cbb90	287	if (state != PM_SUSPEND_TO_IDLE && suspend_ops->finish)
8490fdf9 RW	288	suspend_ops->finish();
	289	}
	290
	291	static int platform_suspend_begin(suspend_state_t state)
	292	{
23d5855f RW	293	if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->begin)
23d5855f RW	294	return s2idle_ops->begin();
fa7fd6fa	295	else if (suspend_ops && suspend_ops->begin)
8490fdf9 RW	296	return suspend_ops->begin(state);
	297	else
	298	return 0;
	299	}
	300
ebc3e41e	301	static void platform_resume_end(suspend_state_t state)
8490fdf9	302	{
23d5855f RW	303	if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->end)
23d5855f RW	304	s2idle_ops->end();
fa7fd6fa	305	else if (suspend_ops && suspend_ops->end)
8490fdf9 RW	306	suspend_ops->end();
	307	}
	308
ebc3e41e	309	static void platform_recover(suspend_state_t state)
8490fdf9	310	{
690cbb90	311	if (state != PM_SUSPEND_TO_IDLE && suspend_ops->recover)
8490fdf9 RW	312	suspend_ops->recover();
	313	}
	314
	315	static bool platform_suspend_again(suspend_state_t state)
	316	{
690cbb90	317	return state != PM_SUSPEND_TO_IDLE && suspend_ops->suspend_again ?
8490fdf9 RW	318	suspend_ops->suspend_again() : false;
	319	}
	320
1d4a9c17 BN	321	#ifdef CONFIG_PM_DEBUG
	322	static unsigned int pm_test_delay = 5;
	323	module_param(pm_test_delay, uint, 0644);
	324	MODULE_PARM_DESC(pm_test_delay,
	325	"Number of seconds to wait before resuming from suspend test");
	326	#endif
	327
a9d70523 RW	328	static int suspend_test(int level)
	329	{
	330	#ifdef CONFIG_PM_DEBUG
	331	if (pm_test_level == level) {
22e09b33	332	pr_info("suspend debug: Waiting for %d second(s).\n",
1d4a9c17 BN	333	pm_test_delay);
1d4a9c17 BN	334	mdelay(pm_test_delay * 1000);
a9d70523 RW	335	return 1;
	336	}
	337	#endif /* !CONFIG_PM_DEBUG */
	338	return 0;
	339	}
	340
	341	/**
55ae4519	342	* suspend_prepare - Prepare for entering system sleep state.
a9d70523	343	*
55ae4519 RW	344	* Common code run for every system sleep state that can be entered (except for
	345	* hibernation). Run suspend notifiers, allocate the "suspend" console and
	346	* freeze processes.
a9d70523	347	*/
7e73c5ae	348	static int suspend_prepare(suspend_state_t state)
a9d70523	349	{
ea00f4f4	350	int error, nr_calls = 0;
a9d70523	351
8490fdf9	352	if (!sleep_state_supported(state))
a9d70523 RW	353	return -EPERM;
	354
	355	pm_prepare_console();
	356
ea00f4f4 LW	357	error = __pm_notifier_call_chain(PM_SUSPEND_PREPARE, -1, &nr_calls);
	358	if (error) {
	359	nr_calls--;
a9d70523	360	goto Finish;
ea00f4f4	361	}
a9d70523	362
bb3632c6	363	trace_suspend_resume(TPS("freeze_processes"), 0, true);
a9d70523	364	error = suspend_freeze_processes();
bb3632c6	365	trace_suspend_resume(TPS("freeze_processes"), 0, false);
03afed8b	366	if (!error)
a9d70523 RW	367	return 0;
a9d70523 RW	368
03afed8b TH	369	suspend_stats.failed_freeze++;
03afed8b TH	370	dpm_save_failed_step(SUSPEND_FREEZE);
a9d70523	371	Finish:
ea00f4f4	372	__pm_notifier_call_chain(PM_POST_SUSPEND, nr_calls, NULL);
a9d70523 RW	373	pm_restore_console();
	374	return error;
	375	}
	376
	377	/* default implementation */
52f5684c	378	void __weak arch_suspend_disable_irqs(void)
a9d70523 RW	379	{
	380	local_irq_disable();
	381	}
	382
	383	/* default implementation */
52f5684c	384	void __weak arch_suspend_enable_irqs(void)
a9d70523 RW	385	{
	386	local_irq_enable();
	387	}
	388
	389	/**
55ae4519 RW	390	* suspend_enter - Make the system enter the given sleep state.
	391	* @state: System sleep state to enter.
	392	* @wakeup: Returns information that the sleep state should not be re-entered.
a9d70523	393	*
3b5fe852	394	* This function should be called after devices have been suspended.
a9d70523	395	*/
3b5fe852	396	static int suspend_enter(suspend_state_t state, bool *wakeup)
a9d70523 RW	397	{
	398	int error;
	399
8490fdf9 RW	400	error = platform_suspend_prepare(state);
	401	if (error)
	402	goto Platform_finish;
a9d70523	403
2a8a8ce6	404	error = dpm_suspend_late(PMSG_SUSPEND);
a9d70523	405	if (error) {
142bce74	406	pr_err("late suspend of devices failed\n");
ce441011	407	goto Platform_finish;
a9d70523	408	}
a8d46b9e RW	409	error = platform_suspend_prepare_late(state);
	410	if (error)
	411	goto Devices_early_resume;
	412
690cbb90	413	if (state == PM_SUSPEND_TO_IDLE && pm_test_level != TEST_PLATFORM) {
8e6bcd9f RW	414	s2idle_loop();
	415	goto Platform_early_resume;
	416	}
	417
2a8a8ce6 RW	418	error = dpm_suspend_noirq(PMSG_SUSPEND);
2a8a8ce6 RW	419	if (error) {
142bce74	420	pr_err("noirq suspend of devices failed\n");
a8d46b9e	421	goto Platform_early_resume;
2a8a8ce6	422	}
ebc3e41e	423	error = platform_suspend_prepare_noirq(state);
8490fdf9 RW	424	if (error)
8490fdf9 RW	425	goto Platform_wake;
a9d70523	426
08605acc ZR	427	if (suspend_test(TEST_PLATFORM))
	428	goto Platform_wake;
	429
a9d70523 RW	430	error = disable_nonboot_cpus();
	431	if (error \|\| suspend_test(TEST_CPUS))
	432	goto Enable_cpus;
	433
	434	arch_suspend_disable_irqs();
	435	BUG_ON(!irqs_disabled());
	436
2e711c04	437	error = syscore_suspend();
a9d70523	438	if (!error) {
3b5fe852 MH	439	*wakeup = pm_wakeup_pending();
3b5fe852 MH	440	if (!(suspend_test(TEST_CORE) \|\| *wakeup)) {
bb3632c6 TB	441	trace_suspend_resume(TPS("machine_suspend"),
bb3632c6 TB	442	state, true);
a9d70523	443	error = suspend_ops->enter(state);
bb3632c6 TB	444	trace_suspend_resume(TPS("machine_suspend"),
bb3632c6 TB	445	state, false);
67176736 RK	446	} else if (*wakeup) {
67176736 RK	447	error = -EBUSY;
c125e96f	448	}
40dc166c	449	syscore_resume();
a9d70523 RW	450	}
	451
	452	arch_suspend_enable_irqs();
	453	BUG_ON(irqs_disabled());
	454
	455	Enable_cpus:
	456	enable_nonboot_cpus();
	457
	458	Platform_wake:
ebc3e41e	459	platform_resume_noirq(state);
2a8a8ce6 RW	460	dpm_resume_noirq(PMSG_RESUME);
2a8a8ce6 RW	461
a8d46b9e RW	462	Platform_early_resume:
	463	platform_resume_early(state);
	464
2a8a8ce6 RW	465	Devices_early_resume:
2a8a8ce6 RW	466	dpm_resume_early(PMSG_RESUME);
a9d70523	467
ce441011	468	Platform_finish:
ebc3e41e	469	platform_resume_finish(state);
a9d70523 RW	470	return error;
	471	}
	472
	473	/**
55ae4519 RW	474	* suspend_devices_and_enter - Suspend devices and enter system sleep state.
55ae4519 RW	475	* @state: System sleep state to enter.
a9d70523 RW	476	*/
	477	int suspend_devices_and_enter(suspend_state_t state)
	478	{
	479	int error;
3b5fe852	480	bool wakeup = false;
a9d70523	481
8490fdf9	482	if (!sleep_state_supported(state))
a9d70523 RW	483	return -ENOSYS;
a9d70523 RW	484
bd8c9ba3 FF	485	pm_suspend_target_state = state;
bd8c9ba3 FF	486
8490fdf9 RW	487	error = platform_suspend_begin(state);
	488	if (error)
	489	goto Close;
	490
a9d70523 RW	491	suspend_console();
	492	suspend_test_start();
	493	error = dpm_suspend_start(PMSG_SUSPEND);
	494	if (error) {
142bce74	495	pr_err("Some devices failed to suspend, or early wake event detected\n");
a9d70523 RW	496	goto Recover_platform;
	497	}
	498	suspend_test_finish("suspend devices");
	499	if (suspend_test(TEST_DEVICES))
	500	goto Recover_platform;
	501
3b5fe852 MH	502	do {
3b5fe852 MH	503	error = suspend_enter(state, &wakeup);
8490fdf9	504	} while (!error && !wakeup && platform_suspend_again(state));
a9d70523 RW	505
	506	Resume_devices:
	507	suspend_test_start();
	508	dpm_resume_end(PMSG_RESUME);
	509	suspend_test_finish("resume devices");
0cadc702	510	trace_suspend_resume(TPS("resume_console"), state, true);
a9d70523	511	resume_console();
0cadc702	512	trace_suspend_resume(TPS("resume_console"), state, false);
1f0b6386	513
8490fdf9	514	Close:
ebc3e41e	515	platform_resume_end(state);
bd8c9ba3	516	pm_suspend_target_state = PM_SUSPEND_ON;
a9d70523 RW	517	return error;
	518
	519	Recover_platform:
ebc3e41e	520	platform_recover(state);
a9d70523 RW	521	goto Resume_devices;
	522	}
	523
	524	/**
55ae4519	525	* suspend_finish - Clean up before finishing the suspend sequence.
a9d70523	526	*
55ae4519 RW	527	* Call platform code to clean up, restart processes, and free the console that
55ae4519 RW	528	* we've allocated. This routine is not called for hibernation.
a9d70523 RW	529	*/
	530	static void suspend_finish(void)
	531	{
	532	suspend_thaw_processes();
a9d70523 RW	533	pm_notifier_call_chain(PM_POST_SUSPEND);
	534	pm_restore_console();
	535	}
	536
	537	/**
55ae4519 RW	538	* enter_state - Do common work needed to enter system sleep state.
55ae4519 RW	539	* @state: System sleep state to enter.
a9d70523	540	*
55ae4519 RW	541	* Make sure that no one else is trying to put the system into a sleep state.
	542	* Fail if that's not the case. Otherwise, prepare for system suspend, make the
	543	* system enter the given sleep state and clean up after wakeup.
a9d70523	544	*/
93e1ee43	545	static int enter_state(suspend_state_t state)
a9d70523 RW	546	{
	547	int error;
	548
bb3632c6	549	trace_suspend_resume(TPS("suspend_enter"), state, true);
690cbb90	550	if (state == PM_SUSPEND_TO_IDLE) {
43e8317b RW	551	#ifdef CONFIG_PM_DEBUG
43e8317b RW	552	if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
142bce74	553	pr_warn("Unsupported test mode for suspend to idle, please choose none/freezer/devices/platform.\n");
43e8317b RW	554	return -EAGAIN;
	555	}
	556	#endif
	557	} else if (!valid_state(state)) {
	558	return -EINVAL;
	559	}
a9d70523 RW	560	if (!mutex_trylock(&pm_mutex))
	561	return -EBUSY;
	562
690cbb90	563	if (state == PM_SUSPEND_TO_IDLE)
f02f4f9d	564	s2idle_begin();
7e73c5ae	565
2fd77fff	566	#ifndef CONFIG_SUSPEND_SKIP_SYNC
bb3632c6	567	trace_suspend_resume(TPS("sync_filesystems"), 0, true);
142bce74	568	pr_info("Syncing filesystems ... ");
a9d70523	569	sys_sync();
1adb469b	570	pr_cont("done.\n");
bb3632c6	571	trace_suspend_resume(TPS("sync_filesystems"), 0, false);
2fd77fff	572	#endif
a9d70523	573
bebcdae3	574	pm_pr_dbg("Preparing system for sleep (%s)\n", mem_sleep_labels[state]);
ef25ba04	575	pm_suspend_clear_flags();
7e73c5ae	576	error = suspend_prepare(state);
a9d70523 RW	577	if (error)
	578	goto Unlock;
	579
	580	if (suspend_test(TEST_FREEZER))
	581	goto Finish;
	582
bb3632c6	583	trace_suspend_resume(TPS("suspend_enter"), state, false);
bebcdae3	584	pm_pr_dbg("Suspending system (%s)\n", mem_sleep_labels[state]);
87186475	585	pm_restrict_gfp_mask();
a9d70523	586	error = suspend_devices_and_enter(state);
87186475	587	pm_restore_gfp_mask();
a9d70523 RW	588
a9d70523 RW	589	Finish:
95b982b4	590	events_check_enabled = false;
8d8b2441	591	pm_pr_dbg("Finishing wakeup.\n");
a9d70523 RW	592	suspend_finish();
	593	Unlock:
	594	mutex_unlock(&pm_mutex);
	595	return error;
	596	}
	597
	598	/**
55ae4519 RW	599	* pm_suspend - Externally visible function for suspending the system.
55ae4519 RW	600	* @state: System sleep state to enter.
a9d70523	601	*
55ae4519 RW	602	* Check if the value of @state represents one of the supported states,
55ae4519 RW	603	* execute enter_state() and update system suspend statistics.
a9d70523 RW	604	*/
	605	int pm_suspend(suspend_state_t state)
	606	{
bc25cf50 RW	607	int error;
	608
	609	if (state <= PM_SUSPEND_ON \|\| state >= PM_SUSPEND_MAX)
	610	return -EINVAL;
	611
142bce74	612	pr_info("suspend entry (%s)\n", mem_sleep_labels[state]);
bc25cf50 RW	613	error = enter_state(state);
	614	if (error) {
	615	suspend_stats.fail++;
	616	dpm_save_failed_errno(error);
	617	} else {
	618	suspend_stats.success++;
2a77c46d	619	}
142bce74	620	pr_info("suspend exit\n");
bc25cf50	621	return error;
a9d70523 RW	622	}
a9d70523 RW	623	EXPORT_SYMBOL(pm_suspend);