[deliverable/linux.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.
 */

#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 "power.h"

static const char *pm_labels[] = { "mem", "standby", "freeze", };
const char *pm_states[PM_SUSPEND_MAX];

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);
static bool suspend_freeze_wake;

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_wake = false;
}

static void freeze_enter(void)
{
	cpuidle_use_deepest_state(true);
	cpuidle_resume();
	wait_event(suspend_freeze_wait_head, suspend_freeze_wake);
	cpuidle_pause();
	cpuidle_use_deepest_state(false);
}

void freeze_wake(void)
{
	suspend_freeze_wake = true;
	wake_up(&suspend_freeze_wait_head);
}
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);
}

/*
 * If this is set, the "mem" label always corresponds to the deepest sleep state
 * available, the "standby" label corresponds to the second deepest sleep state
 * available (if any), and the "freeze" label corresponds to the remaining
 * available sleep state (if there is one).
 */
static bool relative_states;

static int __init sleep_states_setup(char *str)
{
	relative_states = !strncmp(str, "1", 1);
	pm_states[PM_SUSPEND_FREEZE] = pm_labels[relative_states ? 0 : 2];
	return 1;
}

__setup("relative_sleep_states=", sleep_states_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)
{
	suspend_state_t i;
	int j = 0;

	lock_system_sleep();

	suspend_ops = ops;
	for (i = PM_SUSPEND_MEM; i >= PM_SUSPEND_STANDBY; i--)
		if (valid_state(i)) {
			pm_states[i] = pm_labels[j++];
		} else if (!relative_states) {
			pm_states[i] = NULL;
			j++;
		}

	pm_states[PM_SUSPEND_FREEZE] = pm_labels[j];

	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 && suspend_ops->prepare_late ?
		suspend_ops->prepare_late() : 0;
}

static void platform_suspend_wake(suspend_state_t state)
{
	if (state != PM_SUSPEND_FREEZE && suspend_ops->wake)
		suspend_ops->wake();
}

static void platform_suspend_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->begin)
		return suspend_ops->begin(state);
	else
		return 0;
}

static void platform_suspend_end(suspend_state_t state)
{
	if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->end)
		freeze_ops->end();
	else if (suspend_ops->end)
		suspend_ops->end();
}

static void platform_suspend_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;
}

static int suspend_test(int level)
{
#ifdef CONFIG_PM_DEBUG
	if (pm_test_level == level) {
		printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
		mdelay(5000);
		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;

	if (!sleep_state_supported(state))
		return -EPERM;

	pm_prepare_console();

	error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
	if (error)
		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);
	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_end(PMSG_SUSPEND);
	if (error) {
		printk(KERN_ERR "PM: Some devices failed to power down\n");
		goto Platform_finish;
	}
	error = platform_suspend_prepare_late(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;
		}
		syscore_resume();
	}

	arch_suspend_enable_irqs();
	BUG_ON(irqs_disabled());

 Enable_cpus:
	enable_nonboot_cpus();

 Platform_wake:
	platform_suspend_wake(state);
	dpm_resume_start(PMSG_RESUME);

 Platform_finish:
	platform_suspend_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");
	resume_console();

 Close:
	platform_suspend_end(state);
	return error;

 Recover_platform:
	platform_suspend_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_warning("PM: Unsupported test mode for freeze state,"
				   "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();

	trace_suspend_resume(TPS("sync_filesystems"), 0, true);
	printk(KERN_INFO "PM: Syncing filesystems ... ");
	sys_sync();
	printk("done.\n");
	trace_suspend_resume(TPS("sync_filesystems"), 0, false);

	pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
	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: Entering %s sleep\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);
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
	11	#include <linux/string.h>
	12	#include <linux/delay.h>
	13	#include <linux/errno.h>
	14	#include <linux/init.h>
	15	#include <linux/console.h>
	16	#include <linux/cpu.h>
f3f12532	17	#include <linux/cpuidle.h>
a9d70523	18	#include <linux/syscalls.h>
5a0e3ad6	19	#include <linux/gfp.h>
dd4c4f17 MG	20	#include <linux/io.h>
	21	#include <linux/kernel.h>
	22	#include <linux/list.h>
	23	#include <linux/mm.h>
	24	#include <linux/slab.h>
6e5fdeed	25	#include <linux/export.h>
dd4c4f17	26	#include <linux/suspend.h>
40dc166c	27	#include <linux/syscore_ops.h>
443772d4	28	#include <linux/ftrace.h>
938cfed1	29	#include <trace/events/power.h>
52f5684c	30	#include <linux/compiler.h>
a9d70523 RW	31
	32	#include "power.h"
	33
d431cbc5 RW	34	static const char *pm_labels[] = { "mem", "standby", "freeze", };
d431cbc5 RW	35	const char *pm_states[PM_SUSPEND_MAX];
a9d70523	36
2f55ac07	37	static const struct platform_suspend_ops *suspend_ops;
1f0b6386	38	static const struct platform_freeze_ops *freeze_ops;
7e73c5ae ZR	39	static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
	40	static bool suspend_freeze_wake;
	41
1f0b6386 RW	42	void freeze_set_ops(const struct platform_freeze_ops *ops)
	43	{
	44	lock_system_sleep();
	45	freeze_ops = ops;
	46	unlock_system_sleep();
	47	}
	48
7e73c5ae ZR	49	static void freeze_begin(void)
	50	{
	51	suspend_freeze_wake = false;
	52	}
	53
	54	static void freeze_enter(void)
	55	{
a6220fc1	56	cpuidle_use_deepest_state(true);
f3f12532	57	cpuidle_resume();
7e73c5ae	58	wait_event(suspend_freeze_wait_head, suspend_freeze_wake);
f3f12532	59	cpuidle_pause();
a6220fc1	60	cpuidle_use_deepest_state(false);
7e73c5ae ZR	61	}
	62
	63	void freeze_wake(void)
	64	{
	65	suspend_freeze_wake = true;
	66	wake_up(&suspend_freeze_wait_head);
	67	}
	68	EXPORT_SYMBOL_GPL(freeze_wake);
	69
43e8317b RW	70	static bool valid_state(suspend_state_t state)
	71	{
	72	/*
	73	* PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
	74	* support and need to be valid to the low level
	75	* implementation, no valid callback implies that none are valid.
	76	*/
	77	return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
	78	}
	79
0399d4db RW	80	/*
	81	* If this is set, the "mem" label always corresponds to the deepest sleep state
	82	* available, the "standby" label corresponds to the second deepest sleep state
	83	* available (if any), and the "freeze" label corresponds to the remaining
	84	* available sleep state (if there is one).
	85	*/
	86	static bool relative_states;
	87
	88	static int __init sleep_states_setup(char *str)
	89	{
	90	relative_states = !strncmp(str, "1", 1);
d431cbc5	91	pm_states[PM_SUSPEND_FREEZE] = pm_labels[relative_states ? 0 : 2];
0399d4db RW	92	return 1;
	93	}
	94
	95	__setup("relative_sleep_states=", sleep_states_setup);
	96
a9d70523	97	/**
55ae4519 RW	98	* suspend_set_ops - Set the global suspend method table.
55ae4519 RW	99	* @ops: Suspend operations to use.
a9d70523	100	*/
2f55ac07	101	void suspend_set_ops(const struct platform_suspend_ops *ops)
a9d70523	102	{
43e8317b	103	suspend_state_t i;
d431cbc5	104	int j = 0;
43e8317b	105
bcda53fa	106	lock_system_sleep();
43e8317b	107
a9d70523	108	suspend_ops = ops;
0399d4db	109	for (i = PM_SUSPEND_MEM; i >= PM_SUSPEND_STANDBY; i--)
d431cbc5 RW	110	if (valid_state(i)) {
	111	pm_states[i] = pm_labels[j++];
	112	} else if (!relative_states) {
	113	pm_states[i] = NULL;
	114	j++;
	115	}
0399d4db	116
d431cbc5	117	pm_states[PM_SUSPEND_FREEZE] = pm_labels[j];
43e8317b	118
bcda53fa	119	unlock_system_sleep();
a9d70523	120	}
a5e4fd87	121	EXPORT_SYMBOL_GPL(suspend_set_ops);
a9d70523	122
a9d70523	123	/**
55ae4519	124	* suspend_valid_only_mem - Generic memory-only valid callback.
a9d70523	125	*
55ae4519 RW	126	* Platform drivers that implement mem suspend only and only need to check for
	127	* that in their .valid() callback can use this instead of rolling their own
	128	* .valid() callback.
a9d70523 RW	129	*/
	130	int suspend_valid_only_mem(suspend_state_t state)
	131	{
	132	return state == PM_SUSPEND_MEM;
	133	}
a5e4fd87	134	EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
a9d70523	135
8490fdf9 RW	136	static bool sleep_state_supported(suspend_state_t state)
	137	{
	138	return state == PM_SUSPEND_FREEZE \|\| (suspend_ops && suspend_ops->enter);
	139	}
	140
	141	static int platform_suspend_prepare(suspend_state_t state)
	142	{
	143	return state != PM_SUSPEND_FREEZE && suspend_ops->prepare ?
	144	suspend_ops->prepare() : 0;
	145	}
	146
	147	static int platform_suspend_prepare_late(suspend_state_t state)
	148	{
	149	return state != PM_SUSPEND_FREEZE && suspend_ops->prepare_late ?
	150	suspend_ops->prepare_late() : 0;
	151	}
	152
	153	static void platform_suspend_wake(suspend_state_t state)
	154	{
	155	if (state != PM_SUSPEND_FREEZE && suspend_ops->wake)
	156	suspend_ops->wake();
	157	}
	158
	159	static void platform_suspend_finish(suspend_state_t state)
	160	{
	161	if (state != PM_SUSPEND_FREEZE && suspend_ops->finish)
	162	suspend_ops->finish();
	163	}
	164
	165	static int platform_suspend_begin(suspend_state_t state)
	166	{
	167	if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->begin)
	168	return freeze_ops->begin();
	169	else if (suspend_ops->begin)
	170	return suspend_ops->begin(state);
	171	else
	172	return 0;
	173	}
	174
	175	static void platform_suspend_end(suspend_state_t state)
	176	{
	177	if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->end)
	178	freeze_ops->end();
	179	else if (suspend_ops->end)
	180	suspend_ops->end();
	181	}
	182
	183	static void platform_suspend_recover(suspend_state_t state)
	184	{
	185	if (state != PM_SUSPEND_FREEZE && suspend_ops->recover)
	186	suspend_ops->recover();
	187	}
	188
	189	static bool platform_suspend_again(suspend_state_t state)
	190	{
	191	return state != PM_SUSPEND_FREEZE && suspend_ops->suspend_again ?
	192	suspend_ops->suspend_again() : false;
	193	}
	194
a9d70523 RW	195	static int suspend_test(int level)
	196	{
	197	#ifdef CONFIG_PM_DEBUG
	198	if (pm_test_level == level) {
	199	printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
	200	mdelay(5000);
	201	return 1;
	202	}
	203	#endif /* !CONFIG_PM_DEBUG */
	204	return 0;
	205	}
	206
	207	/**
55ae4519	208	* suspend_prepare - Prepare for entering system sleep state.
a9d70523	209	*
55ae4519 RW	210	* Common code run for every system sleep state that can be entered (except for
	211	* hibernation). Run suspend notifiers, allocate the "suspend" console and
	212	* freeze processes.
a9d70523	213	*/
7e73c5ae	214	static int suspend_prepare(suspend_state_t state)
a9d70523 RW	215	{
	216	int error;
	217
8490fdf9	218	if (!sleep_state_supported(state))
a9d70523 RW	219	return -EPERM;
	220
	221	pm_prepare_console();
	222
	223	error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
	224	if (error)
	225	goto Finish;
	226
bb3632c6	227	trace_suspend_resume(TPS("freeze_processes"), 0, true);
a9d70523	228	error = suspend_freeze_processes();
bb3632c6	229	trace_suspend_resume(TPS("freeze_processes"), 0, false);
03afed8b	230	if (!error)
a9d70523 RW	231	return 0;
a9d70523 RW	232
03afed8b TH	233	suspend_stats.failed_freeze++;
03afed8b TH	234	dpm_save_failed_step(SUSPEND_FREEZE);
a9d70523 RW	235	Finish:
	236	pm_notifier_call_chain(PM_POST_SUSPEND);
	237	pm_restore_console();
	238	return error;
	239	}
	240
	241	/* default implementation */
52f5684c	242	void __weak arch_suspend_disable_irqs(void)
a9d70523 RW	243	{
	244	local_irq_disable();
	245	}
	246
	247	/* default implementation */
52f5684c	248	void __weak arch_suspend_enable_irqs(void)
a9d70523 RW	249	{
	250	local_irq_enable();
	251	}
	252
	253	/**
55ae4519 RW	254	* suspend_enter - Make the system enter the given sleep state.
	255	* @state: System sleep state to enter.
	256	* @wakeup: Returns information that the sleep state should not be re-entered.
a9d70523	257	*
3b5fe852	258	* This function should be called after devices have been suspended.
a9d70523	259	*/
3b5fe852	260	static int suspend_enter(suspend_state_t state, bool *wakeup)
a9d70523 RW	261	{
	262	int error;
	263
8490fdf9 RW	264	error = platform_suspend_prepare(state);
	265	if (error)
	266	goto Platform_finish;
a9d70523	267
cf579dfb	268	error = dpm_suspend_end(PMSG_SUSPEND);
a9d70523 RW	269	if (error) {
a9d70523 RW	270	printk(KERN_ERR "PM: Some devices failed to power down\n");
ce441011	271	goto Platform_finish;
a9d70523	272	}
8490fdf9 RW	273	error = platform_suspend_prepare_late(state);
	274	if (error)
	275	goto Platform_wake;
a9d70523	276
08605acc ZR	277	if (suspend_test(TEST_PLATFORM))
	278	goto Platform_wake;
	279
7e73c5ae ZR	280	/*
	281	* PM_SUSPEND_FREEZE equals
	282	* frozen processes + suspended devices + idle processors.
	283	* Thus we should invoke freeze_enter() soon after
	284	* all the devices are suspended.
	285	*/
	286	if (state == PM_SUSPEND_FREEZE) {
bb3632c6	287	trace_suspend_resume(TPS("machine_suspend"), state, true);
7e73c5ae	288	freeze_enter();
bb3632c6	289	trace_suspend_resume(TPS("machine_suspend"), state, false);
7e73c5ae ZR	290	goto Platform_wake;
	291	}
	292
a9d70523 RW	293	error = disable_nonboot_cpus();
	294	if (error \|\| suspend_test(TEST_CPUS))
	295	goto Enable_cpus;
	296
	297	arch_suspend_disable_irqs();
	298	BUG_ON(!irqs_disabled());
	299
2e711c04	300	error = syscore_suspend();
a9d70523	301	if (!error) {
3b5fe852 MH	302	*wakeup = pm_wakeup_pending();
3b5fe852 MH	303	if (!(suspend_test(TEST_CORE) \|\| *wakeup)) {
bb3632c6 TB	304	trace_suspend_resume(TPS("machine_suspend"),
bb3632c6 TB	305	state, true);
a9d70523	306	error = suspend_ops->enter(state);
bb3632c6 TB	307	trace_suspend_resume(TPS("machine_suspend"),
bb3632c6 TB	308	state, false);
c125e96f RW	309	events_check_enabled = false;
c125e96f RW	310	}
40dc166c	311	syscore_resume();
a9d70523 RW	312	}
	313
	314	arch_suspend_enable_irqs();
	315	BUG_ON(irqs_disabled());
	316
	317	Enable_cpus:
	318	enable_nonboot_cpus();
	319
	320	Platform_wake:
8490fdf9	321	platform_suspend_wake(state);
cf579dfb	322	dpm_resume_start(PMSG_RESUME);
a9d70523	323
ce441011	324	Platform_finish:
8490fdf9	325	platform_suspend_finish(state);
a9d70523 RW	326	return error;
	327	}
	328
	329	/**
55ae4519 RW	330	* suspend_devices_and_enter - Suspend devices and enter system sleep state.
55ae4519 RW	331	* @state: System sleep state to enter.
a9d70523 RW	332	*/
	333	int suspend_devices_and_enter(suspend_state_t state)
	334	{
	335	int error;
3b5fe852	336	bool wakeup = false;
a9d70523	337
8490fdf9	338	if (!sleep_state_supported(state))
a9d70523 RW	339	return -ENOSYS;
a9d70523 RW	340
8490fdf9 RW	341	error = platform_suspend_begin(state);
	342	if (error)
	343	goto Close;
	344
a9d70523 RW	345	suspend_console();
	346	suspend_test_start();
	347	error = dpm_suspend_start(PMSG_SUSPEND);
	348	if (error) {
9350de06	349	pr_err("PM: Some devices failed to suspend, or early wake event detected\n");
a9d70523 RW	350	goto Recover_platform;
	351	}
	352	suspend_test_finish("suspend devices");
	353	if (suspend_test(TEST_DEVICES))
	354	goto Recover_platform;
	355
3b5fe852 MH	356	do {
3b5fe852 MH	357	error = suspend_enter(state, &wakeup);
8490fdf9	358	} while (!error && !wakeup && platform_suspend_again(state));
a9d70523 RW	359
	360	Resume_devices:
	361	suspend_test_start();
	362	dpm_resume_end(PMSG_RESUME);
	363	suspend_test_finish("resume devices");
	364	resume_console();
1f0b6386	365
8490fdf9 RW	366	Close:
8490fdf9 RW	367	platform_suspend_end(state);
a9d70523 RW	368	return error;
	369
	370	Recover_platform:
8490fdf9	371	platform_suspend_recover(state);
a9d70523 RW	372	goto Resume_devices;
	373	}
	374
	375	/**
55ae4519	376	* suspend_finish - Clean up before finishing the suspend sequence.
a9d70523	377	*
55ae4519 RW	378	* Call platform code to clean up, restart processes, and free the console that
55ae4519 RW	379	* we've allocated. This routine is not called for hibernation.
a9d70523 RW	380	*/
	381	static void suspend_finish(void)
	382	{
	383	suspend_thaw_processes();
a9d70523 RW	384	pm_notifier_call_chain(PM_POST_SUSPEND);
	385	pm_restore_console();
	386	}
	387
	388	/**
55ae4519 RW	389	* enter_state - Do common work needed to enter system sleep state.
55ae4519 RW	390	* @state: System sleep state to enter.
a9d70523	391	*
55ae4519 RW	392	* Make sure that no one else is trying to put the system into a sleep state.
	393	* Fail if that's not the case. Otherwise, prepare for system suspend, make the
	394	* system enter the given sleep state and clean up after wakeup.
a9d70523	395	*/
93e1ee43	396	static int enter_state(suspend_state_t state)
a9d70523 RW	397	{
	398	int error;
	399
bb3632c6	400	trace_suspend_resume(TPS("suspend_enter"), state, true);
43e8317b RW	401	if (state == PM_SUSPEND_FREEZE) {
	402	#ifdef CONFIG_PM_DEBUG
	403	if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
	404	pr_warning("PM: Unsupported test mode for freeze state,"
	405	"please choose none/freezer/devices/platform.\n");
	406	return -EAGAIN;
	407	}
	408	#endif
	409	} else if (!valid_state(state)) {
	410	return -EINVAL;
	411	}
a9d70523 RW	412	if (!mutex_trylock(&pm_mutex))
	413	return -EBUSY;
	414
7e73c5ae ZR	415	if (state == PM_SUSPEND_FREEZE)
	416	freeze_begin();
	417
bb3632c6	418	trace_suspend_resume(TPS("sync_filesystems"), 0, true);
a9d70523 RW	419	printk(KERN_INFO "PM: Syncing filesystems ... ");
	420	sys_sync();
	421	printk("done.\n");
bb3632c6	422	trace_suspend_resume(TPS("sync_filesystems"), 0, false);
a9d70523	423
d431cbc5	424	pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
7e73c5ae	425	error = suspend_prepare(state);
a9d70523 RW	426	if (error)
	427	goto Unlock;
	428
	429	if (suspend_test(TEST_FREEZER))
	430	goto Finish;
	431
bb3632c6	432	trace_suspend_resume(TPS("suspend_enter"), state, false);
d431cbc5	433	pr_debug("PM: Entering %s sleep\n", pm_states[state]);
87186475	434	pm_restrict_gfp_mask();
a9d70523	435	error = suspend_devices_and_enter(state);
87186475	436	pm_restore_gfp_mask();
a9d70523 RW	437
	438	Finish:
	439	pr_debug("PM: Finishing wakeup.\n");
	440	suspend_finish();
	441	Unlock:
	442	mutex_unlock(&pm_mutex);
	443	return error;
	444	}
	445
	446	/**
55ae4519 RW	447	* pm_suspend - Externally visible function for suspending the system.
55ae4519 RW	448	* @state: System sleep state to enter.
a9d70523	449	*
55ae4519 RW	450	* Check if the value of @state represents one of the supported states,
55ae4519 RW	451	* execute enter_state() and update system suspend statistics.
a9d70523 RW	452	*/
	453	int pm_suspend(suspend_state_t state)
	454	{
bc25cf50 RW	455	int error;
	456
	457	if (state <= PM_SUSPEND_ON \|\| state >= PM_SUSPEND_MAX)
	458	return -EINVAL;
	459
	460	error = enter_state(state);
	461	if (error) {
	462	suspend_stats.fail++;
	463	dpm_save_failed_errno(error);
	464	} else {
	465	suspend_stats.success++;
2a77c46d	466	}
bc25cf50	467	return error;
a9d70523 RW	468	}
a9d70523 RW	469	EXPORT_SYMBOL(pm_suspend);