[linux-2.6-block.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 <linux/moduleparam.h>

#include "power.h"

const char *pm_labels[] = { "mem", "standby", "freeze", NULL };
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);

enum freeze_state __read_mostly suspend_freeze_state;
static DEFINE_SPINLOCK(suspend_freeze_lock);

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_state = FREEZE_STATE_NONE;
}

static void freeze_enter(void)
{
	spin_lock_irq(&suspend_freeze_lock);
	if (pm_wakeup_pending())
		goto out;

	suspend_freeze_state = FREEZE_STATE_ENTER;
	spin_unlock_irq(&suspend_freeze_lock);

	get_online_cpus();
	cpuidle_resume();

	/* Push all the CPUs into the idle loop. */
	wake_up_all_idle_cpus();
	pr_debug("PM: suspend-to-idle\n");
	/* Make the current CPU wait so it can enter the idle loop too. */
	wait_event(suspend_freeze_wait_head,
		   suspend_freeze_state == FREEZE_STATE_WAKE);
	pr_debug("PM: resume from suspend-to-idle\n");

	cpuidle_pause();
	put_online_cpus();

	spin_lock_irq(&suspend_freeze_lock);

 out:
	suspend_freeze_state = FREEZE_STATE_NONE;
	spin_unlock_irq(&suspend_freeze_lock);
}

void freeze_wake(void)
{
	unsigned long flags;

	spin_lock_irqsave(&suspend_freeze_lock, flags);
	if (suspend_freeze_state > FREEZE_STATE_NONE) {
		suspend_freeze_state = FREEZE_STATE_WAKE;
		wake_up(&suspend_freeze_wait_head);
	}
	spin_unlock_irqrestore(&suspend_freeze_lock, flags);
}
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 && freeze_ops && freeze_ops->prepare ?
		freeze_ops->prepare() : 0;
}

static int platform_suspend_prepare_noirq(suspend_state_t state)
{
	return state != PM_SUSPEND_FREEZE && suspend_ops->prepare_late ?
		suspend_ops->prepare_late() : 0;
}

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

static void platform_resume_early(suspend_state_t state)
{
	if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->restore)
		freeze_ops->restore();
}

static void platform_resume_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_resume_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_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;
}

#ifdef CONFIG_PM_DEBUG
static unsigned int pm_test_delay = 5;
module_param(pm_test_delay, uint, 0644);
MODULE_PARM_DESC(pm_test_delay,
		 "Number of seconds to wait before resuming from suspend test");
#endif

static int suspend_test(int level)
{
#ifdef CONFIG_PM_DEBUG
	if (pm_test_level == level) {
		printk(KERN_INFO "suspend debug: Waiting for %d second(s).\n",
				pm_test_delay);
		mdelay(pm_test_delay * 1000);
		return 1;
	}
#endif /* !CONFIG_PM_DEBUG */
	return 0;
}

/**
 * suspend_prepare - Prepare for entering system sleep state.
 *
 * Common code run for every system sleep state that can be entered (except for
 * hibernation).  Run suspend notifiers, allocate the "suspend" console and
 * freeze processes.
 */
static int suspend_prepare(suspend_state_t state)
{
	int error;

	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_late(PMSG_SUSPEND);
	if (error) {
		printk(KERN_ERR "PM: late suspend of devices failed\n");
		goto Platform_finish;
	}
	error = platform_suspend_prepare_late(state);
	if (error)
		goto Devices_early_resume;

	error = dpm_suspend_noirq(PMSG_SUSPEND);
	if (error) {
		printk(KERN_ERR "PM: noirq suspend of devices failed\n");
		goto Platform_early_resume;
	}
	error = platform_suspend_prepare_noirq(state);
	if (error)
		goto Platform_wake;

	if (suspend_test(TEST_PLATFORM))
		goto Platform_wake;

	/*
	 * 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;
		} else if (*wakeup) {
			error = -EBUSY;
		}
		syscore_resume();
	}

	arch_suspend_enable_irqs();
	BUG_ON(irqs_disabled());

 Enable_cpus:
	enable_nonboot_cpus();

 Platform_wake:
	platform_resume_noirq(state);
	dpm_resume_noirq(PMSG_RESUME);

 Platform_early_resume:
	platform_resume_early(state);

 Devices_early_resume:
	dpm_resume_early(PMSG_RESUME);

 Platform_finish:
	platform_resume_finish(state);
	return error;
}

/**
 * suspend_devices_and_enter - Suspend devices and enter system sleep state.
 * @state: System sleep state to enter.
 */
int suspend_devices_and_enter(suspend_state_t state)
{
	int error;
	bool wakeup = false;

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

	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");
	trace_suspend_resume(TPS("resume_console"), state, true);
	resume_console();
	trace_suspend_resume(TPS("resume_console"), state, false);

 Close:
	platform_resume_end(state);
	return error;

 Recover_platform:
	platform_recover(state);
	goto Resume_devices;
}

/**
 * suspend_finish - Clean up before finishing the suspend sequence.
 *
 * Call platform code to clean up, restart processes, and free the console that
 * we've allocated. This routine is not called for hibernation.
 */
static void suspend_finish(void)
{
	suspend_thaw_processes();
	pm_notifier_call_chain(PM_POST_SUSPEND);
	pm_restore_console();
}

/**
 * enter_state - Do common work needed to enter system sleep state.
 * @state: System sleep state to enter.
 *
 * Make sure that no one else is trying to put the system into a sleep state.
 * Fail if that's not the case.  Otherwise, prepare for system suspend, make the
 * system enter the given sleep state and clean up after wakeup.
 */
static int enter_state(suspend_state_t state)
{
	int error;

	trace_suspend_resume(TPS("suspend_enter"), state, true);
	if (state == PM_SUSPEND_FREEZE) {
#ifdef CONFIG_PM_DEBUG
		if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
			pr_warning("PM: Unsupported test mode for suspend to idle,"
				   "please choose none/freezer/devices/platform.\n");
			return -EAGAIN;
		}
#endif
	} else if (!valid_state(state)) {
		return -EINVAL;
	}
	if (!mutex_trylock(&pm_mutex))
		return -EBUSY;

	if (state == PM_SUSPEND_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 sleep (%s)\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: Suspending system (%s)\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>
1d4a9c17	31	#include <linux/moduleparam.h>
a9d70523 RW	32
	33	#include "power.h"
	34
62109b43	35	const char *pm_labels[] = { "mem", "standby", "freeze", NULL };
d431cbc5	36	const char *pm_states[PM_SUSPEND_MAX];
a9d70523	37
2f55ac07	38	static const struct platform_suspend_ops *suspend_ops;
1f0b6386	39	static const struct platform_freeze_ops *freeze_ops;
7e73c5ae	40	static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
38106313 RW	41
	42	enum freeze_state __read_mostly suspend_freeze_state;
	43	static DEFINE_SPINLOCK(suspend_freeze_lock);
7e73c5ae	44
1f0b6386 RW	45	void freeze_set_ops(const struct platform_freeze_ops *ops)
	46	{
	47	lock_system_sleep();
	48	freeze_ops = ops;
	49	unlock_system_sleep();
	50	}
	51
7e73c5ae ZR	52	static void freeze_begin(void)
7e73c5ae ZR	53	{
38106313	54	suspend_freeze_state = FREEZE_STATE_NONE;
7e73c5ae ZR	55	}
	56
	57	static void freeze_enter(void)
	58	{
38106313 RW	59	spin_lock_irq(&suspend_freeze_lock);
	60	if (pm_wakeup_pending())
	61	goto out;
	62
	63	suspend_freeze_state = FREEZE_STATE_ENTER;
	64	spin_unlock_irq(&suspend_freeze_lock);
	65
	66	get_online_cpus();
f3f12532	67	cpuidle_resume();
38106313 RW	68
	69	/* Push all the CPUs into the idle loop. */
	70	wake_up_all_idle_cpus();
	71	pr_debug("PM: suspend-to-idle\n");
	72	/* Make the current CPU wait so it can enter the idle loop too. */
	73	wait_event(suspend_freeze_wait_head,
	74	suspend_freeze_state == FREEZE_STATE_WAKE);
	75	pr_debug("PM: resume from suspend-to-idle\n");
	76
f3f12532	77	cpuidle_pause();
38106313 RW	78	put_online_cpus();
	79
	80	spin_lock_irq(&suspend_freeze_lock);
	81
	82	out:
	83	suspend_freeze_state = FREEZE_STATE_NONE;
	84	spin_unlock_irq(&suspend_freeze_lock);
7e73c5ae ZR	85	}
	86
	87	void freeze_wake(void)
	88	{
38106313 RW	89	unsigned long flags;
	90
	91	spin_lock_irqsave(&suspend_freeze_lock, flags);
	92	if (suspend_freeze_state > FREEZE_STATE_NONE) {
	93	suspend_freeze_state = FREEZE_STATE_WAKE;
	94	wake_up(&suspend_freeze_wait_head);
	95	}
	96	spin_unlock_irqrestore(&suspend_freeze_lock, flags);
7e73c5ae ZR	97	}
	98	EXPORT_SYMBOL_GPL(freeze_wake);
	99
43e8317b RW	100	static bool valid_state(suspend_state_t state)
	101	{
	102	/*
	103	* PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states need low level
	104	* support and need to be valid to the low level
	105	* implementation, no valid callback implies that none are valid.
	106	*/
	107	return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
	108	}
	109
0399d4db RW	110	/*
	111	* If this is set, the "mem" label always corresponds to the deepest sleep state
	112	* available, the "standby" label corresponds to the second deepest sleep state
	113	* available (if any), and the "freeze" label corresponds to the remaining
	114	* available sleep state (if there is one).
	115	*/
	116	static bool relative_states;
	117
	118	static int __init sleep_states_setup(char *str)
	119	{
	120	relative_states = !strncmp(str, "1", 1);
d431cbc5	121	pm_states[PM_SUSPEND_FREEZE] = pm_labels[relative_states ? 0 : 2];
0399d4db RW	122	return 1;
	123	}
	124
	125	__setup("relative_sleep_states=", sleep_states_setup);
	126
a9d70523	127	/**
55ae4519 RW	128	* suspend_set_ops - Set the global suspend method table.
55ae4519 RW	129	* @ops: Suspend operations to use.
a9d70523	130	*/
2f55ac07	131	void suspend_set_ops(const struct platform_suspend_ops *ops)
a9d70523	132	{
43e8317b	133	suspend_state_t i;
d431cbc5	134	int j = 0;
43e8317b	135
bcda53fa	136	lock_system_sleep();
43e8317b	137
a9d70523	138	suspend_ops = ops;
0399d4db	139	for (i = PM_SUSPEND_MEM; i >= PM_SUSPEND_STANDBY; i--)
d431cbc5 RW	140	if (valid_state(i)) {
	141	pm_states[i] = pm_labels[j++];
	142	} else if (!relative_states) {
	143	pm_states[i] = NULL;
	144	j++;
	145	}
0399d4db	146
d431cbc5	147	pm_states[PM_SUSPEND_FREEZE] = pm_labels[j];
43e8317b	148
bcda53fa	149	unlock_system_sleep();
a9d70523	150	}
a5e4fd87	151	EXPORT_SYMBOL_GPL(suspend_set_ops);
a9d70523	152
a9d70523	153	/**
55ae4519	154	* suspend_valid_only_mem - Generic memory-only valid callback.
a9d70523	155	*
55ae4519 RW	156	* Platform drivers that implement mem suspend only and only need to check for
	157	* that in their .valid() callback can use this instead of rolling their own
	158	* .valid() callback.
a9d70523 RW	159	*/
	160	int suspend_valid_only_mem(suspend_state_t state)
	161	{
	162	return state == PM_SUSPEND_MEM;
	163	}
a5e4fd87	164	EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
a9d70523	165
8490fdf9 RW	166	static bool sleep_state_supported(suspend_state_t state)
	167	{
	168	return state == PM_SUSPEND_FREEZE \|\| (suspend_ops && suspend_ops->enter);
	169	}
	170
	171	static int platform_suspend_prepare(suspend_state_t state)
	172	{
	173	return state != PM_SUSPEND_FREEZE && suspend_ops->prepare ?
	174	suspend_ops->prepare() : 0;
	175	}
	176
a8d46b9e RW	177	static int platform_suspend_prepare_late(suspend_state_t state)
a8d46b9e RW	178	{
403b9636	179	return state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->prepare ?
a8d46b9e RW	180	freeze_ops->prepare() : 0;
	181	}
	182
ebc3e41e	183	static int platform_suspend_prepare_noirq(suspend_state_t state)
8490fdf9 RW	184	{
	185	return state != PM_SUSPEND_FREEZE && suspend_ops->prepare_late ?
	186	suspend_ops->prepare_late() : 0;
	187	}
	188
ebc3e41e	189	static void platform_resume_noirq(suspend_state_t state)
8490fdf9 RW	190	{
	191	if (state != PM_SUSPEND_FREEZE && suspend_ops->wake)
	192	suspend_ops->wake();
	193	}
	194
a8d46b9e RW	195	static void platform_resume_early(suspend_state_t state)
a8d46b9e RW	196	{
403b9636	197	if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->restore)
a8d46b9e RW	198	freeze_ops->restore();
	199	}
	200
ebc3e41e	201	static void platform_resume_finish(suspend_state_t state)
8490fdf9 RW	202	{
	203	if (state != PM_SUSPEND_FREEZE && suspend_ops->finish)
	204	suspend_ops->finish();
	205	}
	206
	207	static int platform_suspend_begin(suspend_state_t state)
	208	{
	209	if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->begin)
	210	return freeze_ops->begin();
	211	else if (suspend_ops->begin)
	212	return suspend_ops->begin(state);
	213	else
	214	return 0;
	215	}
	216
ebc3e41e	217	static void platform_resume_end(suspend_state_t state)
8490fdf9 RW	218	{
	219	if (state == PM_SUSPEND_FREEZE && freeze_ops && freeze_ops->end)
	220	freeze_ops->end();
	221	else if (suspend_ops->end)
	222	suspend_ops->end();
	223	}
	224
ebc3e41e	225	static void platform_recover(suspend_state_t state)
8490fdf9 RW	226	{
	227	if (state != PM_SUSPEND_FREEZE && suspend_ops->recover)
	228	suspend_ops->recover();
	229	}
	230
	231	static bool platform_suspend_again(suspend_state_t state)
	232	{
	233	return state != PM_SUSPEND_FREEZE && suspend_ops->suspend_again ?
	234	suspend_ops->suspend_again() : false;
	235	}
	236
1d4a9c17 BN	237	#ifdef CONFIG_PM_DEBUG
	238	static unsigned int pm_test_delay = 5;
	239	module_param(pm_test_delay, uint, 0644);
	240	MODULE_PARM_DESC(pm_test_delay,
	241	"Number of seconds to wait before resuming from suspend test");
	242	#endif
	243
a9d70523 RW	244	static int suspend_test(int level)
	245	{
	246	#ifdef CONFIG_PM_DEBUG
	247	if (pm_test_level == level) {
1d4a9c17 BN	248	printk(KERN_INFO "suspend debug: Waiting for %d second(s).\n",
	249	pm_test_delay);
	250	mdelay(pm_test_delay * 1000);
a9d70523 RW	251	return 1;
	252	}
	253	#endif /* !CONFIG_PM_DEBUG */
	254	return 0;
	255	}
	256
	257	/**
55ae4519	258	* suspend_prepare - Prepare for entering system sleep state.
a9d70523	259	*
55ae4519 RW	260	* Common code run for every system sleep state that can be entered (except for
	261	* hibernation). Run suspend notifiers, allocate the "suspend" console and
	262	* freeze processes.
a9d70523	263	*/
7e73c5ae	264	static int suspend_prepare(suspend_state_t state)
a9d70523 RW	265	{
	266	int error;
	267
8490fdf9	268	if (!sleep_state_supported(state))
a9d70523 RW	269	return -EPERM;
	270
	271	pm_prepare_console();
	272
	273	error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
	274	if (error)
	275	goto Finish;
	276
bb3632c6	277	trace_suspend_resume(TPS("freeze_processes"), 0, true);
a9d70523	278	error = suspend_freeze_processes();
bb3632c6	279	trace_suspend_resume(TPS("freeze_processes"), 0, false);
03afed8b	280	if (!error)
a9d70523 RW	281	return 0;
a9d70523 RW	282
03afed8b TH	283	suspend_stats.failed_freeze++;
03afed8b TH	284	dpm_save_failed_step(SUSPEND_FREEZE);
a9d70523 RW	285	Finish:
	286	pm_notifier_call_chain(PM_POST_SUSPEND);
	287	pm_restore_console();
	288	return error;
	289	}
	290
	291	/* default implementation */
52f5684c	292	void __weak arch_suspend_disable_irqs(void)
a9d70523 RW	293	{
	294	local_irq_disable();
	295	}
	296
	297	/* default implementation */
52f5684c	298	void __weak arch_suspend_enable_irqs(void)
a9d70523 RW	299	{
	300	local_irq_enable();
	301	}
	302
	303	/**
55ae4519 RW	304	* suspend_enter - Make the system enter the given sleep state.
	305	* @state: System sleep state to enter.
	306	* @wakeup: Returns information that the sleep state should not be re-entered.
a9d70523	307	*
3b5fe852	308	* This function should be called after devices have been suspended.
a9d70523	309	*/
3b5fe852	310	static int suspend_enter(suspend_state_t state, bool *wakeup)
a9d70523 RW	311	{
	312	int error;
	313
8490fdf9 RW	314	error = platform_suspend_prepare(state);
	315	if (error)
	316	goto Platform_finish;
a9d70523	317
2a8a8ce6	318	error = dpm_suspend_late(PMSG_SUSPEND);
a9d70523	319	if (error) {
2a8a8ce6	320	printk(KERN_ERR "PM: late suspend of devices failed\n");
ce441011	321	goto Platform_finish;
a9d70523	322	}
a8d46b9e RW	323	error = platform_suspend_prepare_late(state);
	324	if (error)
	325	goto Devices_early_resume;
	326
2a8a8ce6 RW	327	error = dpm_suspend_noirq(PMSG_SUSPEND);
	328	if (error) {
	329	printk(KERN_ERR "PM: noirq suspend of devices failed\n");
a8d46b9e	330	goto Platform_early_resume;
2a8a8ce6	331	}
ebc3e41e	332	error = platform_suspend_prepare_noirq(state);
8490fdf9 RW	333	if (error)
8490fdf9 RW	334	goto Platform_wake;
a9d70523	335
08605acc ZR	336	if (suspend_test(TEST_PLATFORM))
	337	goto Platform_wake;
	338
7e73c5ae ZR	339	/*
	340	* PM_SUSPEND_FREEZE equals
	341	* frozen processes + suspended devices + idle processors.
	342	* Thus we should invoke freeze_enter() soon after
	343	* all the devices are suspended.
	344	*/
	345	if (state == PM_SUSPEND_FREEZE) {
bb3632c6	346	trace_suspend_resume(TPS("machine_suspend"), state, true);
7e73c5ae	347	freeze_enter();
bb3632c6	348	trace_suspend_resume(TPS("machine_suspend"), state, false);
7e73c5ae ZR	349	goto Platform_wake;
	350	}
	351
a9d70523 RW	352	error = disable_nonboot_cpus();
	353	if (error \|\| suspend_test(TEST_CPUS))
	354	goto Enable_cpus;
	355
	356	arch_suspend_disable_irqs();
	357	BUG_ON(!irqs_disabled());
	358
2e711c04	359	error = syscore_suspend();
a9d70523	360	if (!error) {
3b5fe852 MH	361	*wakeup = pm_wakeup_pending();
3b5fe852 MH	362	if (!(suspend_test(TEST_CORE) \|\| *wakeup)) {
bb3632c6 TB	363	trace_suspend_resume(TPS("machine_suspend"),
bb3632c6 TB	364	state, true);
a9d70523	365	error = suspend_ops->enter(state);
bb3632c6 TB	366	trace_suspend_resume(TPS("machine_suspend"),
bb3632c6 TB	367	state, false);
c125e96f	368	events_check_enabled = false;
67176736 RK	369	} else if (*wakeup) {
67176736 RK	370	error = -EBUSY;
c125e96f	371	}
40dc166c	372	syscore_resume();
a9d70523 RW	373	}
	374
	375	arch_suspend_enable_irqs();
	376	BUG_ON(irqs_disabled());
	377
	378	Enable_cpus:
	379	enable_nonboot_cpus();
	380
	381	Platform_wake:
ebc3e41e	382	platform_resume_noirq(state);
2a8a8ce6 RW	383	dpm_resume_noirq(PMSG_RESUME);
2a8a8ce6 RW	384
a8d46b9e RW	385	Platform_early_resume:
	386	platform_resume_early(state);
	387
2a8a8ce6 RW	388	Devices_early_resume:
2a8a8ce6 RW	389	dpm_resume_early(PMSG_RESUME);
a9d70523	390
ce441011	391	Platform_finish:
ebc3e41e	392	platform_resume_finish(state);
a9d70523 RW	393	return error;
	394	}
	395
	396	/**
55ae4519 RW	397	* suspend_devices_and_enter - Suspend devices and enter system sleep state.
55ae4519 RW	398	* @state: System sleep state to enter.
a9d70523 RW	399	*/
	400	int suspend_devices_and_enter(suspend_state_t state)
	401	{
	402	int error;
3b5fe852	403	bool wakeup = false;
a9d70523	404
8490fdf9	405	if (!sleep_state_supported(state))
a9d70523 RW	406	return -ENOSYS;
a9d70523 RW	407
8490fdf9 RW	408	error = platform_suspend_begin(state);
	409	if (error)
	410	goto Close;
	411
a9d70523 RW	412	suspend_console();
	413	suspend_test_start();
	414	error = dpm_suspend_start(PMSG_SUSPEND);
	415	if (error) {
9350de06	416	pr_err("PM: Some devices failed to suspend, or early wake event detected\n");
a9d70523 RW	417	goto Recover_platform;
	418	}
	419	suspend_test_finish("suspend devices");
	420	if (suspend_test(TEST_DEVICES))
	421	goto Recover_platform;
	422
3b5fe852 MH	423	do {
3b5fe852 MH	424	error = suspend_enter(state, &wakeup);
8490fdf9	425	} while (!error && !wakeup && platform_suspend_again(state));
a9d70523 RW	426
	427	Resume_devices:
	428	suspend_test_start();
	429	dpm_resume_end(PMSG_RESUME);
	430	suspend_test_finish("resume devices");
0cadc702	431	trace_suspend_resume(TPS("resume_console"), state, true);
a9d70523	432	resume_console();
0cadc702	433	trace_suspend_resume(TPS("resume_console"), state, false);
1f0b6386	434
8490fdf9	435	Close:
ebc3e41e	436	platform_resume_end(state);
a9d70523 RW	437	return error;
	438
	439	Recover_platform:
ebc3e41e	440	platform_recover(state);
a9d70523 RW	441	goto Resume_devices;
	442	}
	443
	444	/**
55ae4519	445	* suspend_finish - Clean up before finishing the suspend sequence.
a9d70523	446	*
55ae4519 RW	447	* Call platform code to clean up, restart processes, and free the console that
55ae4519 RW	448	* we've allocated. This routine is not called for hibernation.
a9d70523 RW	449	*/
	450	static void suspend_finish(void)
	451	{
	452	suspend_thaw_processes();
a9d70523 RW	453	pm_notifier_call_chain(PM_POST_SUSPEND);
	454	pm_restore_console();
	455	}
	456
	457	/**
55ae4519 RW	458	* enter_state - Do common work needed to enter system sleep state.
55ae4519 RW	459	* @state: System sleep state to enter.
a9d70523	460	*
55ae4519 RW	461	* Make sure that no one else is trying to put the system into a sleep state.
	462	* Fail if that's not the case. Otherwise, prepare for system suspend, make the
	463	* system enter the given sleep state and clean up after wakeup.
a9d70523	464	*/
93e1ee43	465	static int enter_state(suspend_state_t state)
a9d70523 RW	466	{
	467	int error;
	468
bb3632c6	469	trace_suspend_resume(TPS("suspend_enter"), state, true);
43e8317b RW	470	if (state == PM_SUSPEND_FREEZE) {
	471	#ifdef CONFIG_PM_DEBUG
	472	if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
a9215045	473	pr_warning("PM: Unsupported test mode for suspend to idle,"
43e8317b RW	474	"please choose none/freezer/devices/platform.\n");
	475	return -EAGAIN;
	476	}
	477	#endif
	478	} else if (!valid_state(state)) {
	479	return -EINVAL;
	480	}
a9d70523 RW	481	if (!mutex_trylock(&pm_mutex))
	482	return -EBUSY;
	483
7e73c5ae ZR	484	if (state == PM_SUSPEND_FREEZE)
	485	freeze_begin();
	486
bb3632c6	487	trace_suspend_resume(TPS("sync_filesystems"), 0, true);
a9d70523 RW	488	printk(KERN_INFO "PM: Syncing filesystems ... ");
	489	sys_sync();
	490	printk("done.\n");
bb3632c6	491	trace_suspend_resume(TPS("sync_filesystems"), 0, false);
a9d70523	492
a9215045	493	pr_debug("PM: Preparing system for sleep (%s)\n", pm_states[state]);
7e73c5ae	494	error = suspend_prepare(state);
a9d70523 RW	495	if (error)
	496	goto Unlock;
	497
	498	if (suspend_test(TEST_FREEZER))
	499	goto Finish;
	500
bb3632c6	501	trace_suspend_resume(TPS("suspend_enter"), state, false);
a9215045	502	pr_debug("PM: Suspending system (%s)\n", pm_states[state]);
87186475	503	pm_restrict_gfp_mask();
a9d70523	504	error = suspend_devices_and_enter(state);
87186475	505	pm_restore_gfp_mask();
a9d70523 RW	506
	507	Finish:
	508	pr_debug("PM: Finishing wakeup.\n");
	509	suspend_finish();
	510	Unlock:
	511	mutex_unlock(&pm_mutex);
	512	return error;
	513	}
	514
	515	/**
55ae4519 RW	516	* pm_suspend - Externally visible function for suspending the system.
55ae4519 RW	517	* @state: System sleep state to enter.
a9d70523	518	*
55ae4519 RW	519	* Check if the value of @state represents one of the supported states,
55ae4519 RW	520	* execute enter_state() and update system suspend statistics.
a9d70523 RW	521	*/
	522	int pm_suspend(suspend_state_t state)
	523	{
bc25cf50 RW	524	int error;
	525
	526	if (state <= PM_SUSPEND_ON \|\| state >= PM_SUSPEND_MAX)
	527	return -EINVAL;
	528
	529	error = enter_state(state);
	530	if (error) {
	531	suspend_stats.fail++;
	532	dpm_save_failed_errno(error);
	533	} else {
	534	suspend_stats.success++;
2a77c46d	535	}
bc25cf50	536	return error;
a9d70523 RW	537	}
a9d70523 RW	538	EXPORT_SYMBOL(pm_suspend);