[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 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;

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 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;

	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;

	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) {
		trace_suspend_resume(TPS("machine_suspend"), state, true);
		freeze_enter();
		trace_suspend_resume(TPS("machine_suspend"), state, false);
		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)) {
			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();
	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;

	if (need_suspend_ops(state) && suspend_ops->begin) {
		error = suspend_ops->begin(state);
		if (error)
			goto Close;
	} else if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->begin) {
		error = freeze_ops->begin();
		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();
	else if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->end)
		freeze_ops->end();

	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;

	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;
a9d70523	39
7e73c5ae ZR	40	static bool need_suspend_ops(suspend_state_t state)
7e73c5ae ZR	41	{
7500d936	42	return state > PM_SUSPEND_FREEZE;
7e73c5ae ZR	43	}
	44
	45	static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
	46	static bool suspend_freeze_wake;
	47
1f0b6386 RW	48	void freeze_set_ops(const struct platform_freeze_ops *ops)
	49	{
	50	lock_system_sleep();
	51	freeze_ops = ops;
	52	unlock_system_sleep();
	53	}
	54
7e73c5ae ZR	55	static void freeze_begin(void)
	56	{
	57	suspend_freeze_wake = false;
	58	}
	59
	60	static void freeze_enter(void)
	61	{
a6220fc1	62	cpuidle_use_deepest_state(true);
f3f12532	63	cpuidle_resume();
7e73c5ae	64	wait_event(suspend_freeze_wait_head, suspend_freeze_wake);
f3f12532	65	cpuidle_pause();
a6220fc1	66	cpuidle_use_deepest_state(false);
7e73c5ae ZR	67	}
	68
	69	void freeze_wake(void)
	70	{
	71	suspend_freeze_wake = true;
	72	wake_up(&suspend_freeze_wait_head);
	73	}
	74	EXPORT_SYMBOL_GPL(freeze_wake);
	75
43e8317b RW	76	static bool valid_state(suspend_state_t state)
	77	{
	78	/*
	79	* PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
	80	* support and need to be valid to the low level
	81	* implementation, no valid callback implies that none are valid.
	82	*/
	83	return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
	84	}
	85
0399d4db RW	86	/*
	87	* If this is set, the "mem" label always corresponds to the deepest sleep state
	88	* available, the "standby" label corresponds to the second deepest sleep state
	89	* available (if any), and the "freeze" label corresponds to the remaining
	90	* available sleep state (if there is one).
	91	*/
	92	static bool relative_states;
	93
	94	static int __init sleep_states_setup(char *str)
	95	{
	96	relative_states = !strncmp(str, "1", 1);
d431cbc5	97	pm_states[PM_SUSPEND_FREEZE] = pm_labels[relative_states ? 0 : 2];
0399d4db RW	98	return 1;
	99	}
	100
	101	__setup("relative_sleep_states=", sleep_states_setup);
	102
a9d70523	103	/**
55ae4519 RW	104	* suspend_set_ops - Set the global suspend method table.
55ae4519 RW	105	* @ops: Suspend operations to use.
a9d70523	106	*/
2f55ac07	107	void suspend_set_ops(const struct platform_suspend_ops *ops)
a9d70523	108	{
43e8317b	109	suspend_state_t i;
d431cbc5	110	int j = 0;
43e8317b	111
bcda53fa	112	lock_system_sleep();
43e8317b	113
a9d70523	114	suspend_ops = ops;
0399d4db	115	for (i = PM_SUSPEND_MEM; i >= PM_SUSPEND_STANDBY; i--)
d431cbc5 RW	116	if (valid_state(i)) {
	117	pm_states[i] = pm_labels[j++];
	118	} else if (!relative_states) {
	119	pm_states[i] = NULL;
	120	j++;
	121	}
0399d4db	122
d431cbc5	123	pm_states[PM_SUSPEND_FREEZE] = pm_labels[j];
43e8317b	124
bcda53fa	125	unlock_system_sleep();
a9d70523	126	}
a5e4fd87	127	EXPORT_SYMBOL_GPL(suspend_set_ops);
a9d70523	128
a9d70523	129	/**
55ae4519	130	* suspend_valid_only_mem - Generic memory-only valid callback.
a9d70523	131	*
55ae4519 RW	132	* Platform drivers that implement mem suspend only and only need to check for
	133	* that in their .valid() callback can use this instead of rolling their own
	134	* .valid() callback.
a9d70523 RW	135	*/
	136	int suspend_valid_only_mem(suspend_state_t state)
	137	{
	138	return state == PM_SUSPEND_MEM;
	139	}
a5e4fd87	140	EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
a9d70523 RW	141
	142	static int suspend_test(int level)
	143	{
	144	#ifdef CONFIG_PM_DEBUG
	145	if (pm_test_level == level) {
	146	printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
	147	mdelay(5000);
	148	return 1;
	149	}
	150	#endif /* !CONFIG_PM_DEBUG */
	151	return 0;
	152	}
	153
	154	/**
55ae4519	155	* suspend_prepare - Prepare for entering system sleep state.
a9d70523	156	*
55ae4519 RW	157	* Common code run for every system sleep state that can be entered (except for
	158	* hibernation). Run suspend notifiers, allocate the "suspend" console and
	159	* freeze processes.
a9d70523	160	*/
7e73c5ae	161	static int suspend_prepare(suspend_state_t state)
a9d70523 RW	162	{
	163	int error;
	164
7e73c5ae	165	if (need_suspend_ops(state) && (!suspend_ops \|\| !suspend_ops->enter))
a9d70523 RW	166	return -EPERM;
	167
	168	pm_prepare_console();
	169
	170	error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
	171	if (error)
	172	goto Finish;
	173
bb3632c6	174	trace_suspend_resume(TPS("freeze_processes"), 0, true);
a9d70523	175	error = suspend_freeze_processes();
bb3632c6	176	trace_suspend_resume(TPS("freeze_processes"), 0, false);
03afed8b	177	if (!error)
a9d70523 RW	178	return 0;
a9d70523 RW	179
03afed8b TH	180	suspend_stats.failed_freeze++;
03afed8b TH	181	dpm_save_failed_step(SUSPEND_FREEZE);
a9d70523 RW	182	Finish:
	183	pm_notifier_call_chain(PM_POST_SUSPEND);
	184	pm_restore_console();
	185	return error;
	186	}
	187
	188	/* default implementation */
52f5684c	189	void __weak arch_suspend_disable_irqs(void)
a9d70523 RW	190	{
	191	local_irq_disable();
	192	}
	193
	194	/* default implementation */
52f5684c	195	void __weak arch_suspend_enable_irqs(void)
a9d70523 RW	196	{
	197	local_irq_enable();
	198	}
	199
	200	/**
55ae4519 RW	201	* suspend_enter - Make the system enter the given sleep state.
	202	* @state: System sleep state to enter.
	203	* @wakeup: Returns information that the sleep state should not be re-entered.
a9d70523	204	*
3b5fe852	205	* This function should be called after devices have been suspended.
a9d70523	206	*/
3b5fe852	207	static int suspend_enter(suspend_state_t state, bool *wakeup)
a9d70523 RW	208	{
	209	int error;
	210
7e73c5ae	211	if (need_suspend_ops(state) && suspend_ops->prepare) {
a9d70523 RW	212	error = suspend_ops->prepare();
a9d70523 RW	213	if (error)
ce441011	214	goto Platform_finish;
a9d70523 RW	215	}
a9d70523 RW	216
cf579dfb	217	error = dpm_suspend_end(PMSG_SUSPEND);
a9d70523 RW	218	if (error) {
a9d70523 RW	219	printk(KERN_ERR "PM: Some devices failed to power down\n");
ce441011	220	goto Platform_finish;
a9d70523 RW	221	}
a9d70523 RW	222
7e73c5ae	223	if (need_suspend_ops(state) && suspend_ops->prepare_late) {
a9d70523 RW	224	error = suspend_ops->prepare_late();
a9d70523 RW	225	if (error)
ce441011	226	goto Platform_wake;
a9d70523 RW	227	}
a9d70523 RW	228
08605acc ZR	229	if (suspend_test(TEST_PLATFORM))
	230	goto Platform_wake;
	231
7e73c5ae ZR	232	/*
	233	* PM_SUSPEND_FREEZE equals
	234	* frozen processes + suspended devices + idle processors.
	235	* Thus we should invoke freeze_enter() soon after
	236	* all the devices are suspended.
	237	*/
	238	if (state == PM_SUSPEND_FREEZE) {
bb3632c6	239	trace_suspend_resume(TPS("machine_suspend"), state, true);
7e73c5ae	240	freeze_enter();
bb3632c6	241	trace_suspend_resume(TPS("machine_suspend"), state, false);
7e73c5ae ZR	242	goto Platform_wake;
	243	}
	244
3831261e	245	ftrace_stop();
a9d70523 RW	246	error = disable_nonboot_cpus();
	247	if (error \|\| suspend_test(TEST_CPUS))
	248	goto Enable_cpus;
	249
	250	arch_suspend_disable_irqs();
	251	BUG_ON(!irqs_disabled());
	252
2e711c04	253	error = syscore_suspend();
a9d70523	254	if (!error) {
3b5fe852 MH	255	*wakeup = pm_wakeup_pending();
3b5fe852 MH	256	if (!(suspend_test(TEST_CORE) \|\| *wakeup)) {
bb3632c6 TB	257	trace_suspend_resume(TPS("machine_suspend"),
bb3632c6 TB	258	state, true);
a9d70523	259	error = suspend_ops->enter(state);
bb3632c6 TB	260	trace_suspend_resume(TPS("machine_suspend"),
bb3632c6 TB	261	state, false);
c125e96f RW	262	events_check_enabled = false;
c125e96f RW	263	}
40dc166c	264	syscore_resume();
a9d70523 RW	265	}
	266
	267	arch_suspend_enable_irqs();
	268	BUG_ON(irqs_disabled());
	269
	270	Enable_cpus:
	271	enable_nonboot_cpus();
3831261e	272	ftrace_start();
a9d70523 RW	273
a9d70523 RW	274	Platform_wake:
7e73c5ae	275	if (need_suspend_ops(state) && suspend_ops->wake)
a9d70523 RW	276	suspend_ops->wake();
a9d70523 RW	277
cf579dfb	278	dpm_resume_start(PMSG_RESUME);
a9d70523	279
ce441011	280	Platform_finish:
7e73c5ae	281	if (need_suspend_ops(state) && suspend_ops->finish)
a9d70523 RW	282	suspend_ops->finish();
	283
	284	return error;
	285	}
	286
	287	/**
55ae4519 RW	288	* suspend_devices_and_enter - Suspend devices and enter system sleep state.
55ae4519 RW	289	* @state: System sleep state to enter.
a9d70523 RW	290	*/
	291	int suspend_devices_and_enter(suspend_state_t state)
	292	{
	293	int error;
3b5fe852	294	bool wakeup = false;
a9d70523	295
7e73c5ae	296	if (need_suspend_ops(state) && !suspend_ops)
a9d70523 RW	297	return -ENOSYS;
a9d70523 RW	298
7e73c5ae	299	if (need_suspend_ops(state) && suspend_ops->begin) {
a9d70523 RW	300	error = suspend_ops->begin(state);
	301	if (error)
	302	goto Close;
653a3538	303	} else if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->begin) {
1f0b6386 RW	304	error = freeze_ops->begin();
	305	if (error)
	306	goto Close;
a9d70523 RW	307	}
	308	suspend_console();
	309	suspend_test_start();
	310	error = dpm_suspend_start(PMSG_SUSPEND);
	311	if (error) {
9350de06	312	pr_err("PM: Some devices failed to suspend, or early wake event detected\n");
a9d70523 RW	313	goto Recover_platform;
	314	}
	315	suspend_test_finish("suspend devices");
	316	if (suspend_test(TEST_DEVICES))
	317	goto Recover_platform;
	318
3b5fe852 MH	319	do {
3b5fe852 MH	320	error = suspend_enter(state, &wakeup);
7e73c5ae	321	} while (!error && !wakeup && need_suspend_ops(state)
3b5fe852	322	&& suspend_ops->suspend_again && suspend_ops->suspend_again());
a9d70523 RW	323
	324	Resume_devices:
	325	suspend_test_start();
	326	dpm_resume_end(PMSG_RESUME);
	327	suspend_test_finish("resume devices");
	328	resume_console();
	329	Close:
7e73c5ae	330	if (need_suspend_ops(state) && suspend_ops->end)
a9d70523	331	suspend_ops->end();
653a3538	332	else if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->end)
1f0b6386 RW	333	freeze_ops->end();
1f0b6386 RW	334
a9d70523 RW	335	return error;
	336
	337	Recover_platform:
7e73c5ae	338	if (need_suspend_ops(state) && suspend_ops->recover)
a9d70523 RW	339	suspend_ops->recover();
	340	goto Resume_devices;
	341	}
	342
	343	/**
55ae4519	344	* suspend_finish - Clean up before finishing the suspend sequence.
a9d70523	345	*
55ae4519 RW	346	* Call platform code to clean up, restart processes, and free the console that
55ae4519 RW	347	* we've allocated. This routine is not called for hibernation.
a9d70523 RW	348	*/
	349	static void suspend_finish(void)
	350	{
	351	suspend_thaw_processes();
a9d70523 RW	352	pm_notifier_call_chain(PM_POST_SUSPEND);
	353	pm_restore_console();
	354	}
	355
	356	/**
55ae4519 RW	357	* enter_state - Do common work needed to enter system sleep state.
55ae4519 RW	358	* @state: System sleep state to enter.
a9d70523	359	*
55ae4519 RW	360	* Make sure that no one else is trying to put the system into a sleep state.
	361	* Fail if that's not the case. Otherwise, prepare for system suspend, make the
	362	* system enter the given sleep state and clean up after wakeup.
a9d70523	363	*/
93e1ee43	364	static int enter_state(suspend_state_t state)
a9d70523 RW	365	{
	366	int error;
	367
bb3632c6	368	trace_suspend_resume(TPS("suspend_enter"), state, true);
43e8317b RW	369	if (state == PM_SUSPEND_FREEZE) {
	370	#ifdef CONFIG_PM_DEBUG
	371	if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
	372	pr_warning("PM: Unsupported test mode for freeze state,"
	373	"please choose none/freezer/devices/platform.\n");
	374	return -EAGAIN;
	375	}
	376	#endif
	377	} else if (!valid_state(state)) {
	378	return -EINVAL;
	379	}
a9d70523 RW	380	if (!mutex_trylock(&pm_mutex))
	381	return -EBUSY;
	382
7e73c5ae ZR	383	if (state == PM_SUSPEND_FREEZE)
	384	freeze_begin();
	385
bb3632c6	386	trace_suspend_resume(TPS("sync_filesystems"), 0, true);
a9d70523 RW	387	printk(KERN_INFO "PM: Syncing filesystems ... ");
	388	sys_sync();
	389	printk("done.\n");
bb3632c6	390	trace_suspend_resume(TPS("sync_filesystems"), 0, false);
a9d70523	391
d431cbc5	392	pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
7e73c5ae	393	error = suspend_prepare(state);
a9d70523 RW	394	if (error)
	395	goto Unlock;
	396
	397	if (suspend_test(TEST_FREEZER))
	398	goto Finish;
	399
bb3632c6	400	trace_suspend_resume(TPS("suspend_enter"), state, false);
d431cbc5	401	pr_debug("PM: Entering %s sleep\n", pm_states[state]);
87186475	402	pm_restrict_gfp_mask();
a9d70523	403	error = suspend_devices_and_enter(state);
87186475	404	pm_restore_gfp_mask();
a9d70523 RW	405
	406	Finish:
	407	pr_debug("PM: Finishing wakeup.\n");
	408	suspend_finish();
	409	Unlock:
	410	mutex_unlock(&pm_mutex);
	411	return error;
	412	}
	413
	414	/**
55ae4519 RW	415	* pm_suspend - Externally visible function for suspending the system.
55ae4519 RW	416	* @state: System sleep state to enter.
a9d70523	417	*
55ae4519 RW	418	* Check if the value of @state represents one of the supported states,
55ae4519 RW	419	* execute enter_state() and update system suspend statistics.
a9d70523 RW	420	*/
	421	int pm_suspend(suspend_state_t state)
	422	{
bc25cf50 RW	423	int error;
	424
	425	if (state <= PM_SUSPEND_ON \|\| state >= PM_SUSPEND_MAX)
	426	return -EINVAL;
	427
	428	error = enter_state(state);
	429	if (error) {
	430	suspend_stats.fail++;
	431	dpm_save_failed_errno(error);
	432	} else {
	433	suspend_stats.success++;
2a77c46d	434	}
bc25cf50	435	return error;
a9d70523 RW	436	}
a9d70523 RW	437	EXPORT_SYMBOL(pm_suspend);