[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/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)
{
	wait_event(suspend_freeze_wait_head, suspend_freeze_wake);
}

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>
	17	#include <linux/syscalls.h>
5a0e3ad6	18	#include <linux/gfp.h>
dd4c4f17 MG	19	#include <linux/io.h>
	20	#include <linux/kernel.h>
	21	#include <linux/list.h>
	22	#include <linux/mm.h>
	23	#include <linux/slab.h>
6e5fdeed	24	#include <linux/export.h>
dd4c4f17	25	#include <linux/suspend.h>
40dc166c	26	#include <linux/syscore_ops.h>
443772d4	27	#include <linux/ftrace.h>
938cfed1	28	#include <trace/events/power.h>
52f5684c	29	#include <linux/compiler.h>
a9d70523 RW	30
	31	#include "power.h"
	32
	33	const char *const pm_states[PM_SUSPEND_MAX] = {
7e73c5ae	34	[PM_SUSPEND_FREEZE] = "freeze",
a9d70523 RW	35	[PM_SUSPEND_STANDBY] = "standby",
	36	[PM_SUSPEND_MEM] = "mem",
	37	};
	38
2f55ac07	39	static const struct platform_suspend_ops *suspend_ops;
a9d70523	40
7e73c5ae ZR	41	static bool need_suspend_ops(suspend_state_t state)
7e73c5ae ZR	42	{
7500d936	43	return state > PM_SUSPEND_FREEZE;
7e73c5ae ZR	44	}
	45
	46	static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
	47	static bool suspend_freeze_wake;
	48
	49	static void freeze_begin(void)
	50	{
	51	suspend_freeze_wake = false;
	52	}
	53
	54	static void freeze_enter(void)
	55	{
	56	wait_event(suspend_freeze_wait_head, suspend_freeze_wake);
	57	}
	58
	59	void freeze_wake(void)
	60	{
	61	suspend_freeze_wake = true;
	62	wake_up(&suspend_freeze_wait_head);
	63	}
	64	EXPORT_SYMBOL_GPL(freeze_wake);
	65
a9d70523	66	/**
55ae4519 RW	67	* suspend_set_ops - Set the global suspend method table.
55ae4519 RW	68	* @ops: Suspend operations to use.
a9d70523	69	*/
2f55ac07	70	void suspend_set_ops(const struct platform_suspend_ops *ops)
a9d70523	71	{
bcda53fa	72	lock_system_sleep();
a9d70523	73	suspend_ops = ops;
bcda53fa	74	unlock_system_sleep();
a9d70523	75	}
a5e4fd87	76	EXPORT_SYMBOL_GPL(suspend_set_ops);
a9d70523 RW	77
	78	bool valid_state(suspend_state_t state)
	79	{
c26b78a2 ZR	80	if (state == PM_SUSPEND_FREEZE) {
	81	#ifdef CONFIG_PM_DEBUG
	82	if (pm_test_level != TEST_NONE &&
	83	pm_test_level != TEST_FREEZER &&
	84	pm_test_level != TEST_DEVICES &&
	85	pm_test_level != TEST_PLATFORM) {
	86	printk(KERN_WARNING "Unsupported pm_test mode for "
	87	"freeze state, please choose "
	88	"none/freezer/devices/platform.\n");
	89	return false;
	90	}
	91	#endif
	92	return true;
	93	}
a9d70523	94	/*
7e73c5ae ZR	95	* PM_SUSPEND_STANDBY and PM_SUSPEND_MEMORY states need lowlevel
7e73c5ae ZR	96	* support and need to be valid to the lowlevel
a9d70523 RW	97	* implementation, no valid callback implies that none are valid.
	98	*/
	99	return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
	100	}
	101
	102	/**
55ae4519	103	* suspend_valid_only_mem - Generic memory-only valid callback.
a9d70523	104	*
55ae4519 RW	105	* Platform drivers that implement mem suspend only and only need to check for
	106	* that in their .valid() callback can use this instead of rolling their own
	107	* .valid() callback.
a9d70523 RW	108	*/
	109	int suspend_valid_only_mem(suspend_state_t state)
	110	{
	111	return state == PM_SUSPEND_MEM;
	112	}
a5e4fd87	113	EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
a9d70523 RW	114
	115	static int suspend_test(int level)
	116	{
	117	#ifdef CONFIG_PM_DEBUG
	118	if (pm_test_level == level) {
	119	printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
	120	mdelay(5000);
	121	return 1;
	122	}
	123	#endif /* !CONFIG_PM_DEBUG */
	124	return 0;
	125	}
	126
	127	/**
55ae4519	128	* suspend_prepare - Prepare for entering system sleep state.
a9d70523	129	*
55ae4519 RW	130	* Common code run for every system sleep state that can be entered (except for
	131	* hibernation). Run suspend notifiers, allocate the "suspend" console and
	132	* freeze processes.
a9d70523	133	*/
7e73c5ae	134	static int suspend_prepare(suspend_state_t state)
a9d70523 RW	135	{
	136	int error;
	137
7e73c5ae	138	if (need_suspend_ops(state) && (!suspend_ops \|\| !suspend_ops->enter))
a9d70523 RW	139	return -EPERM;
	140
	141	pm_prepare_console();
	142
	143	error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
	144	if (error)
	145	goto Finish;
	146
a9d70523	147	error = suspend_freeze_processes();
03afed8b	148	if (!error)
a9d70523 RW	149	return 0;
a9d70523 RW	150
03afed8b TH	151	suspend_stats.failed_freeze++;
03afed8b TH	152	dpm_save_failed_step(SUSPEND_FREEZE);
a9d70523 RW	153	Finish:
	154	pm_notifier_call_chain(PM_POST_SUSPEND);
	155	pm_restore_console();
	156	return error;
	157	}
	158
	159	/* default implementation */
52f5684c	160	void __weak arch_suspend_disable_irqs(void)
a9d70523 RW	161	{
	162	local_irq_disable();
	163	}
	164
	165	/* default implementation */
52f5684c	166	void __weak arch_suspend_enable_irqs(void)
a9d70523 RW	167	{
	168	local_irq_enable();
	169	}
	170
	171	/**
55ae4519 RW	172	* suspend_enter - Make the system enter the given sleep state.
	173	* @state: System sleep state to enter.
	174	* @wakeup: Returns information that the sleep state should not be re-entered.
a9d70523	175	*
3b5fe852	176	* This function should be called after devices have been suspended.
a9d70523	177	*/
3b5fe852	178	static int suspend_enter(suspend_state_t state, bool *wakeup)
a9d70523 RW	179	{
	180	int error;
	181
7e73c5ae	182	if (need_suspend_ops(state) && suspend_ops->prepare) {
a9d70523 RW	183	error = suspend_ops->prepare();
a9d70523 RW	184	if (error)
ce441011	185	goto Platform_finish;
a9d70523 RW	186	}
a9d70523 RW	187
cf579dfb	188	error = dpm_suspend_end(PMSG_SUSPEND);
a9d70523 RW	189	if (error) {
a9d70523 RW	190	printk(KERN_ERR "PM: Some devices failed to power down\n");
ce441011	191	goto Platform_finish;
a9d70523 RW	192	}
a9d70523 RW	193
7e73c5ae	194	if (need_suspend_ops(state) && suspend_ops->prepare_late) {
a9d70523 RW	195	error = suspend_ops->prepare_late();
a9d70523 RW	196	if (error)
ce441011	197	goto Platform_wake;
a9d70523 RW	198	}
a9d70523 RW	199
08605acc ZR	200	if (suspend_test(TEST_PLATFORM))
	201	goto Platform_wake;
	202
7e73c5ae ZR	203	/*
	204	* PM_SUSPEND_FREEZE equals
	205	* frozen processes + suspended devices + idle processors.
	206	* Thus we should invoke freeze_enter() soon after
	207	* all the devices are suspended.
	208	*/
	209	if (state == PM_SUSPEND_FREEZE) {
	210	freeze_enter();
	211	goto Platform_wake;
	212	}
	213
3831261e	214	ftrace_stop();
a9d70523 RW	215	error = disable_nonboot_cpus();
	216	if (error \|\| suspend_test(TEST_CPUS))
	217	goto Enable_cpus;
	218
	219	arch_suspend_disable_irqs();
	220	BUG_ON(!irqs_disabled());
	221
2e711c04	222	error = syscore_suspend();
a9d70523	223	if (!error) {
3b5fe852 MH	224	*wakeup = pm_wakeup_pending();
3b5fe852 MH	225	if (!(suspend_test(TEST_CORE) \|\| *wakeup)) {
a9d70523	226	error = suspend_ops->enter(state);
c125e96f RW	227	events_check_enabled = false;
c125e96f RW	228	}
40dc166c	229	syscore_resume();
a9d70523 RW	230	}
	231
	232	arch_suspend_enable_irqs();
	233	BUG_ON(irqs_disabled());
	234
	235	Enable_cpus:
	236	enable_nonboot_cpus();
3831261e	237	ftrace_start();
a9d70523 RW	238
a9d70523 RW	239	Platform_wake:
7e73c5ae	240	if (need_suspend_ops(state) && suspend_ops->wake)
a9d70523 RW	241	suspend_ops->wake();
a9d70523 RW	242
cf579dfb	243	dpm_resume_start(PMSG_RESUME);
a9d70523	244
ce441011	245	Platform_finish:
7e73c5ae	246	if (need_suspend_ops(state) && suspend_ops->finish)
a9d70523 RW	247	suspend_ops->finish();
	248
	249	return error;
	250	}
	251
	252	/**
55ae4519 RW	253	* suspend_devices_and_enter - Suspend devices and enter system sleep state.
55ae4519 RW	254	* @state: System sleep state to enter.
a9d70523 RW	255	*/
	256	int suspend_devices_and_enter(suspend_state_t state)
	257	{
	258	int error;
3b5fe852	259	bool wakeup = false;
a9d70523	260
7e73c5ae	261	if (need_suspend_ops(state) && !suspend_ops)
a9d70523 RW	262	return -ENOSYS;
a9d70523 RW	263
938cfed1	264	trace_machine_suspend(state);
7e73c5ae	265	if (need_suspend_ops(state) && suspend_ops->begin) {
a9d70523 RW	266	error = suspend_ops->begin(state);
	267	if (error)
	268	goto Close;
	269	}
	270	suspend_console();
	271	suspend_test_start();
	272	error = dpm_suspend_start(PMSG_SUSPEND);
	273	if (error) {
9350de06	274	pr_err("PM: Some devices failed to suspend, or early wake event detected\n");
a9d70523 RW	275	goto Recover_platform;
	276	}
	277	suspend_test_finish("suspend devices");
	278	if (suspend_test(TEST_DEVICES))
	279	goto Recover_platform;
	280
3b5fe852 MH	281	do {
3b5fe852 MH	282	error = suspend_enter(state, &wakeup);
7e73c5ae	283	} while (!error && !wakeup && need_suspend_ops(state)
3b5fe852	284	&& suspend_ops->suspend_again && suspend_ops->suspend_again());
a9d70523 RW	285
	286	Resume_devices:
	287	suspend_test_start();
	288	dpm_resume_end(PMSG_RESUME);
	289	suspend_test_finish("resume devices");
	290	resume_console();
	291	Close:
7e73c5ae	292	if (need_suspend_ops(state) && suspend_ops->end)
a9d70523	293	suspend_ops->end();
938cfed1	294	trace_machine_suspend(PWR_EVENT_EXIT);
a9d70523 RW	295	return error;
	296
	297	Recover_platform:
7e73c5ae	298	if (need_suspend_ops(state) && suspend_ops->recover)
a9d70523 RW	299	suspend_ops->recover();
	300	goto Resume_devices;
	301	}
	302
	303	/**
55ae4519	304	* suspend_finish - Clean up before finishing the suspend sequence.
a9d70523	305	*
55ae4519 RW	306	* Call platform code to clean up, restart processes, and free the console that
55ae4519 RW	307	* we've allocated. This routine is not called for hibernation.
a9d70523 RW	308	*/
	309	static void suspend_finish(void)
	310	{
	311	suspend_thaw_processes();
a9d70523 RW	312	pm_notifier_call_chain(PM_POST_SUSPEND);
	313	pm_restore_console();
	314	}
	315
	316	/**
55ae4519 RW	317	* enter_state - Do common work needed to enter system sleep state.
55ae4519 RW	318	* @state: System sleep state to enter.
a9d70523	319	*
55ae4519 RW	320	* Make sure that no one else is trying to put the system into a sleep state.
	321	* Fail if that's not the case. Otherwise, prepare for system suspend, make the
	322	* system enter the given sleep state and clean up after wakeup.
a9d70523	323	*/
93e1ee43	324	static int enter_state(suspend_state_t state)
a9d70523 RW	325	{
	326	int error;
	327
	328	if (!valid_state(state))
	329	return -ENODEV;
	330
	331	if (!mutex_trylock(&pm_mutex))
	332	return -EBUSY;
	333
7e73c5ae ZR	334	if (state == PM_SUSPEND_FREEZE)
	335	freeze_begin();
	336
a9d70523 RW	337	printk(KERN_INFO "PM: Syncing filesystems ... ");
	338	sys_sync();
	339	printk("done.\n");
	340
	341	pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
7e73c5ae	342	error = suspend_prepare(state);
a9d70523 RW	343	if (error)
	344	goto Unlock;
	345
	346	if (suspend_test(TEST_FREEZER))
	347	goto Finish;
	348
	349	pr_debug("PM: Entering %s sleep\n", pm_states[state]);
87186475	350	pm_restrict_gfp_mask();
a9d70523	351	error = suspend_devices_and_enter(state);
87186475	352	pm_restore_gfp_mask();
a9d70523 RW	353
	354	Finish:
	355	pr_debug("PM: Finishing wakeup.\n");
	356	suspend_finish();
	357	Unlock:
	358	mutex_unlock(&pm_mutex);
	359	return error;
	360	}
	361
	362	/**
55ae4519 RW	363	* pm_suspend - Externally visible function for suspending the system.
55ae4519 RW	364	* @state: System sleep state to enter.
a9d70523	365	*
55ae4519 RW	366	* Check if the value of @state represents one of the supported states,
55ae4519 RW	367	* execute enter_state() and update system suspend statistics.
a9d70523 RW	368	*/
	369	int pm_suspend(suspend_state_t state)
	370	{
bc25cf50 RW	371	int error;
	372
	373	if (state <= PM_SUSPEND_ON \|\| state >= PM_SUSPEND_MAX)
	374	return -EINVAL;
	375
	376	error = enter_state(state);
	377	if (error) {
	378	suspend_stats.fail++;
	379	dpm_save_failed_errno(error);
	380	} else {
	381	suspend_stats.success++;
2a77c46d	382	}
bc25cf50	383	return error;
a9d70523 RW	384	}
a9d70523 RW	385	EXPORT_SYMBOL(pm_suspend);