[mirror_ubuntu-zesty-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.
 */

#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"

const char *const pm_states[PM_SUSPEND_MAX] = {
	[PM_SUSPEND_FREEZE]	= "freeze",
	[PM_SUSPEND_STANDBY]	= "standby",
	[PM_SUSPEND_MEM]	= "mem",
};

static const struct platform_suspend_ops *suspend_ops;

static bool need_suspend_ops(suspend_state_t state)
{
	return state > PM_SUSPEND_FREEZE;
}

static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
static bool suspend_freeze_wake;

static void freeze_begin(void)
{
	suspend_freeze_wake = false;
}

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

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

/**
 * 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;
	unlock_system_sleep();
}
EXPORT_SYMBOL_GPL(suspend_set_ops);

bool valid_state(suspend_state_t state)
{
	if (state == PM_SUSPEND_FREEZE) {
#ifdef CONFIG_PM_DEBUG
		if (pm_test_level != TEST_NONE &&
		    pm_test_level != TEST_FREEZER &&
		    pm_test_level != TEST_DEVICES &&
		    pm_test_level != TEST_PLATFORM) {
			printk(KERN_WARNING "Unsupported pm_test mode for "
					"freeze state, please choose "
					"none/freezer/devices/platform.\n");
			return false;
		}
#endif
			return true;
	}
	/*
	 * PM_SUSPEND_STANDBY and PM_SUSPEND_MEMORY states need lowlevel
	 * support and need to be valid to the lowlevel
	 * implementation, no valid callback implies that none are valid.
	 */
	return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
}

/**
 * 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 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 (need_suspend_ops(state) && (!suspend_ops || !suspend_ops->enter))
		return -EPERM;

	pm_prepare_console();

	error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
	if (error)
		goto Finish;

	error = suspend_freeze_processes();
	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;

	if (need_suspend_ops(state) && suspend_ops->prepare) {
		error = suspend_ops->prepare();
		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;
	}

	if (need_suspend_ops(state) && suspend_ops->prepare_late) {
		error = suspend_ops->prepare_late();
		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) {
		freeze_enter();
		goto Platform_wake;
	}

	ftrace_stop();
	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)) {
			error = suspend_ops->enter(state);
			events_check_enabled = false;
		}
		syscore_resume();
	}

	arch_suspend_enable_irqs();
	BUG_ON(irqs_disabled());

 Enable_cpus:
	enable_nonboot_cpus();
	ftrace_start();

 Platform_wake:
	if (need_suspend_ops(state) && suspend_ops->wake)
		suspend_ops->wake();

	dpm_resume_start(PMSG_RESUME);

 Platform_finish:
	if (need_suspend_ops(state) && suspend_ops->finish)
		suspend_ops->finish();

	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 (need_suspend_ops(state) && !suspend_ops)
		return -ENOSYS;

	trace_machine_suspend(state);
	if (need_suspend_ops(state) && suspend_ops->begin) {
		error = suspend_ops->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 && need_suspend_ops(state)
		&& suspend_ops->suspend_again && suspend_ops->suspend_again());

 Resume_devices:
	suspend_test_start();
	dpm_resume_end(PMSG_RESUME);
	suspend_test_finish("resume devices");
	resume_console();
 Close:
	if (need_suspend_ops(state) && suspend_ops->end)
		suspend_ops->end();
	trace_machine_suspend(PWR_EVENT_EXIT);
	return error;

 Recover_platform:
	if (need_suspend_ops(state) && suspend_ops->recover)
		suspend_ops->recover();
	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;

	if (!valid_state(state))
		return -ENODEV;

	if (!mutex_trylock(&pm_mutex))
		return -EBUSY;

	if (state == PM_SUSPEND_FREEZE)
		freeze_begin();

	printk(KERN_INFO "PM: Syncing filesystems ... ");
	sys_sync();
	printk("done.\n");

	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;

	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
	34	const char *const pm_states[PM_SUSPEND_MAX] = {
7e73c5ae	35	[PM_SUSPEND_FREEZE] = "freeze",
a9d70523 RW	36	[PM_SUSPEND_STANDBY] = "standby",
	37	[PM_SUSPEND_MEM] = "mem",
	38	};
	39
2f55ac07	40	static const struct platform_suspend_ops *suspend_ops;
a9d70523	41
7e73c5ae ZR	42	static bool need_suspend_ops(suspend_state_t state)
7e73c5ae ZR	43	{
7500d936	44	return state > PM_SUSPEND_FREEZE;
7e73c5ae ZR	45	}
	46
	47	static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
	48	static bool suspend_freeze_wake;
	49
	50	static void freeze_begin(void)
	51	{
	52	suspend_freeze_wake = false;
	53	}
	54
	55	static void freeze_enter(void)
	56	{
f3f12532	57	cpuidle_resume();
7e73c5ae	58	wait_event(suspend_freeze_wait_head, suspend_freeze_wake);
f3f12532	59	cpuidle_pause();
7e73c5ae ZR	60	}
	61
	62	void freeze_wake(void)
	63	{
	64	suspend_freeze_wake = true;
	65	wake_up(&suspend_freeze_wait_head);
	66	}
	67	EXPORT_SYMBOL_GPL(freeze_wake);
	68
a9d70523	69	/**
55ae4519 RW	70	* suspend_set_ops - Set the global suspend method table.
55ae4519 RW	71	* @ops: Suspend operations to use.
a9d70523	72	*/
2f55ac07	73	void suspend_set_ops(const struct platform_suspend_ops *ops)
a9d70523	74	{
bcda53fa	75	lock_system_sleep();
a9d70523	76	suspend_ops = ops;
bcda53fa	77	unlock_system_sleep();
a9d70523	78	}
a5e4fd87	79	EXPORT_SYMBOL_GPL(suspend_set_ops);
a9d70523 RW	80
	81	bool valid_state(suspend_state_t state)
	82	{
c26b78a2 ZR	83	if (state == PM_SUSPEND_FREEZE) {
	84	#ifdef CONFIG_PM_DEBUG
	85	if (pm_test_level != TEST_NONE &&
	86	pm_test_level != TEST_FREEZER &&
	87	pm_test_level != TEST_DEVICES &&
	88	pm_test_level != TEST_PLATFORM) {
	89	printk(KERN_WARNING "Unsupported pm_test mode for "
	90	"freeze state, please choose "
	91	"none/freezer/devices/platform.\n");
	92	return false;
	93	}
	94	#endif
	95	return true;
	96	}
a9d70523	97	/*
7e73c5ae ZR	98	* PM_SUSPEND_STANDBY and PM_SUSPEND_MEMORY states need lowlevel
7e73c5ae ZR	99	* support and need to be valid to the lowlevel
a9d70523 RW	100	* implementation, no valid callback implies that none are valid.
	101	*/
	102	return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
	103	}
	104
	105	/**
55ae4519	106	* suspend_valid_only_mem - Generic memory-only valid callback.
a9d70523	107	*
55ae4519 RW	108	* Platform drivers that implement mem suspend only and only need to check for
	109	* that in their .valid() callback can use this instead of rolling their own
	110	* .valid() callback.
a9d70523 RW	111	*/
	112	int suspend_valid_only_mem(suspend_state_t state)
	113	{
	114	return state == PM_SUSPEND_MEM;
	115	}
a5e4fd87	116	EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
a9d70523 RW	117
	118	static int suspend_test(int level)
	119	{
	120	#ifdef CONFIG_PM_DEBUG
	121	if (pm_test_level == level) {
	122	printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
	123	mdelay(5000);
	124	return 1;
	125	}
	126	#endif /* !CONFIG_PM_DEBUG */
	127	return 0;
	128	}
	129
	130	/**
55ae4519	131	* suspend_prepare - Prepare for entering system sleep state.
a9d70523	132	*
55ae4519 RW	133	* Common code run for every system sleep state that can be entered (except for
	134	* hibernation). Run suspend notifiers, allocate the "suspend" console and
	135	* freeze processes.
a9d70523	136	*/
7e73c5ae	137	static int suspend_prepare(suspend_state_t state)
a9d70523 RW	138	{
	139	int error;
	140
7e73c5ae	141	if (need_suspend_ops(state) && (!suspend_ops \|\| !suspend_ops->enter))
a9d70523 RW	142	return -EPERM;
	143
	144	pm_prepare_console();
	145
	146	error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
	147	if (error)
	148	goto Finish;
	149
a9d70523	150	error = suspend_freeze_processes();
03afed8b	151	if (!error)
a9d70523 RW	152	return 0;
a9d70523 RW	153
03afed8b TH	154	suspend_stats.failed_freeze++;
03afed8b TH	155	dpm_save_failed_step(SUSPEND_FREEZE);
a9d70523 RW	156	Finish:
	157	pm_notifier_call_chain(PM_POST_SUSPEND);
	158	pm_restore_console();
	159	return error;
	160	}
	161
	162	/* default implementation */
52f5684c	163	void __weak arch_suspend_disable_irqs(void)
a9d70523 RW	164	{
	165	local_irq_disable();
	166	}
	167
	168	/* default implementation */
52f5684c	169	void __weak arch_suspend_enable_irqs(void)
a9d70523 RW	170	{
	171	local_irq_enable();
	172	}
	173
	174	/**
55ae4519 RW	175	* suspend_enter - Make the system enter the given sleep state.
	176	* @state: System sleep state to enter.
	177	* @wakeup: Returns information that the sleep state should not be re-entered.
a9d70523	178	*
3b5fe852	179	* This function should be called after devices have been suspended.
a9d70523	180	*/
3b5fe852	181	static int suspend_enter(suspend_state_t state, bool *wakeup)
a9d70523 RW	182	{
	183	int error;
	184
7e73c5ae	185	if (need_suspend_ops(state) && suspend_ops->prepare) {
a9d70523 RW	186	error = suspend_ops->prepare();
a9d70523 RW	187	if (error)
ce441011	188	goto Platform_finish;
a9d70523 RW	189	}
a9d70523 RW	190
cf579dfb	191	error = dpm_suspend_end(PMSG_SUSPEND);
a9d70523 RW	192	if (error) {
a9d70523 RW	193	printk(KERN_ERR "PM: Some devices failed to power down\n");
ce441011	194	goto Platform_finish;
a9d70523 RW	195	}
a9d70523 RW	196
7e73c5ae	197	if (need_suspend_ops(state) && suspend_ops->prepare_late) {
a9d70523 RW	198	error = suspend_ops->prepare_late();
a9d70523 RW	199	if (error)
ce441011	200	goto Platform_wake;
a9d70523 RW	201	}
a9d70523 RW	202
08605acc ZR	203	if (suspend_test(TEST_PLATFORM))
	204	goto Platform_wake;
	205
7e73c5ae ZR	206	/*
	207	* PM_SUSPEND_FREEZE equals
	208	* frozen processes + suspended devices + idle processors.
	209	* Thus we should invoke freeze_enter() soon after
	210	* all the devices are suspended.
	211	*/
	212	if (state == PM_SUSPEND_FREEZE) {
	213	freeze_enter();
	214	goto Platform_wake;
	215	}
	216
3831261e	217	ftrace_stop();
a9d70523 RW	218	error = disable_nonboot_cpus();
	219	if (error \|\| suspend_test(TEST_CPUS))
	220	goto Enable_cpus;
	221
	222	arch_suspend_disable_irqs();
	223	BUG_ON(!irqs_disabled());
	224
2e711c04	225	error = syscore_suspend();
a9d70523	226	if (!error) {
3b5fe852 MH	227	*wakeup = pm_wakeup_pending();
3b5fe852 MH	228	if (!(suspend_test(TEST_CORE) \|\| *wakeup)) {
a9d70523	229	error = suspend_ops->enter(state);
c125e96f RW	230	events_check_enabled = false;
c125e96f RW	231	}
40dc166c	232	syscore_resume();
a9d70523 RW	233	}
	234
	235	arch_suspend_enable_irqs();
	236	BUG_ON(irqs_disabled());
	237
	238	Enable_cpus:
	239	enable_nonboot_cpus();
3831261e	240	ftrace_start();
a9d70523 RW	241
a9d70523 RW	242	Platform_wake:
7e73c5ae	243	if (need_suspend_ops(state) && suspend_ops->wake)
a9d70523 RW	244	suspend_ops->wake();
a9d70523 RW	245
cf579dfb	246	dpm_resume_start(PMSG_RESUME);
a9d70523	247
ce441011	248	Platform_finish:
7e73c5ae	249	if (need_suspend_ops(state) && suspend_ops->finish)
a9d70523 RW	250	suspend_ops->finish();
	251
	252	return error;
	253	}
	254
	255	/**
55ae4519 RW	256	* suspend_devices_and_enter - Suspend devices and enter system sleep state.
55ae4519 RW	257	* @state: System sleep state to enter.
a9d70523 RW	258	*/
	259	int suspend_devices_and_enter(suspend_state_t state)
	260	{
	261	int error;
3b5fe852	262	bool wakeup = false;
a9d70523	263
7e73c5ae	264	if (need_suspend_ops(state) && !suspend_ops)
a9d70523 RW	265	return -ENOSYS;
a9d70523 RW	266
938cfed1	267	trace_machine_suspend(state);
7e73c5ae	268	if (need_suspend_ops(state) && suspend_ops->begin) {
a9d70523 RW	269	error = suspend_ops->begin(state);
	270	if (error)
	271	goto Close;
	272	}
	273	suspend_console();
	274	suspend_test_start();
	275	error = dpm_suspend_start(PMSG_SUSPEND);
	276	if (error) {
9350de06	277	pr_err("PM: Some devices failed to suspend, or early wake event detected\n");
a9d70523 RW	278	goto Recover_platform;
	279	}
	280	suspend_test_finish("suspend devices");
	281	if (suspend_test(TEST_DEVICES))
	282	goto Recover_platform;
	283
3b5fe852 MH	284	do {
3b5fe852 MH	285	error = suspend_enter(state, &wakeup);
7e73c5ae	286	} while (!error && !wakeup && need_suspend_ops(state)
3b5fe852	287	&& suspend_ops->suspend_again && suspend_ops->suspend_again());
a9d70523 RW	288
	289	Resume_devices:
	290	suspend_test_start();
	291	dpm_resume_end(PMSG_RESUME);
	292	suspend_test_finish("resume devices");
	293	resume_console();
	294	Close:
7e73c5ae	295	if (need_suspend_ops(state) && suspend_ops->end)
a9d70523	296	suspend_ops->end();
938cfed1	297	trace_machine_suspend(PWR_EVENT_EXIT);
a9d70523 RW	298	return error;
	299
	300	Recover_platform:
7e73c5ae	301	if (need_suspend_ops(state) && suspend_ops->recover)
a9d70523 RW	302	suspend_ops->recover();
	303	goto Resume_devices;
	304	}
	305
	306	/**
55ae4519	307	* suspend_finish - Clean up before finishing the suspend sequence.
a9d70523	308	*
55ae4519 RW	309	* Call platform code to clean up, restart processes, and free the console that
55ae4519 RW	310	* we've allocated. This routine is not called for hibernation.
a9d70523 RW	311	*/
	312	static void suspend_finish(void)
	313	{
	314	suspend_thaw_processes();
a9d70523 RW	315	pm_notifier_call_chain(PM_POST_SUSPEND);
	316	pm_restore_console();
	317	}
	318
	319	/**
55ae4519 RW	320	* enter_state - Do common work needed to enter system sleep state.
55ae4519 RW	321	* @state: System sleep state to enter.
a9d70523	322	*
55ae4519 RW	323	* Make sure that no one else is trying to put the system into a sleep state.
	324	* Fail if that's not the case. Otherwise, prepare for system suspend, make the
	325	* system enter the given sleep state and clean up after wakeup.
a9d70523	326	*/
93e1ee43	327	static int enter_state(suspend_state_t state)
a9d70523 RW	328	{
	329	int error;
	330
	331	if (!valid_state(state))
	332	return -ENODEV;
	333
	334	if (!mutex_trylock(&pm_mutex))
	335	return -EBUSY;
	336
7e73c5ae ZR	337	if (state == PM_SUSPEND_FREEZE)
	338	freeze_begin();
	339
a9d70523 RW	340	printk(KERN_INFO "PM: Syncing filesystems ... ");
	341	sys_sync();
	342	printk("done.\n");
	343
	344	pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
7e73c5ae	345	error = suspend_prepare(state);
a9d70523 RW	346	if (error)
	347	goto Unlock;
	348
	349	if (suspend_test(TEST_FREEZER))
	350	goto Finish;
	351
	352	pr_debug("PM: Entering %s sleep\n", pm_states[state]);
87186475	353	pm_restrict_gfp_mask();
a9d70523	354	error = suspend_devices_and_enter(state);
87186475	355	pm_restore_gfp_mask();
a9d70523 RW	356
	357	Finish:
	358	pr_debug("PM: Finishing wakeup.\n");
	359	suspend_finish();
	360	Unlock:
	361	mutex_unlock(&pm_mutex);
	362	return error;
	363	}
	364
	365	/**
55ae4519 RW	366	* pm_suspend - Externally visible function for suspending the system.
55ae4519 RW	367	* @state: System sleep state to enter.
a9d70523	368	*
55ae4519 RW	369	* Check if the value of @state represents one of the supported states,
55ae4519 RW	370	* execute enter_state() and update system suspend statistics.
a9d70523 RW	371	*/
	372	int pm_suspend(suspend_state_t state)
	373	{
bc25cf50 RW	374	int error;
	375
	376	if (state <= PM_SUSPEND_ON \|\| state >= PM_SUSPEND_MAX)
	377	return -EINVAL;
	378
	379	error = enter_state(state);
	380	if (error) {
	381	suspend_stats.fail++;
	382	dpm_save_failed_errno(error);
	383	} else {
	384	suspend_stats.success++;
2a77c46d	385	}
bc25cf50	386	return error;
a9d70523 RW	387	}
a9d70523 RW	388	EXPORT_SYMBOL(pm_suspend);