[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 <trace/events/power.h>

#include "power.h"

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

static const struct platform_suspend_ops *suspend_ops;

/**
 * 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)
{
	/*
	 * All 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(void)
{
	int error;

	if (!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 __attribute__ ((weak)) arch_suspend_disable_irqs(void)
{
	local_irq_disable();
}

/* default implementation */
void __attribute__ ((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 (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 (suspend_ops->prepare_late) {
		error = suspend_ops->prepare_late();
		if (error)
			goto Platform_wake;
	}

	if (suspend_test(TEST_PLATFORM))
		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)) {
			error = suspend_ops->enter(state);
			events_check_enabled = false;
		}
		syscore_resume();
	}

	arch_suspend_enable_irqs();
	BUG_ON(irqs_disabled());

 Enable_cpus:
	enable_nonboot_cpus();

 Platform_wake:
	if (suspend_ops->wake)
		suspend_ops->wake();

	dpm_resume_start(PMSG_RESUME);

 Platform_finish:
	if (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 (!suspend_ops)
		return -ENOSYS;

	trace_machine_suspend(state);
	if (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) {
		printk(KERN_ERR "PM: Some devices failed to suspend\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
		&& 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 (suspend_ops->end)
		suspend_ops->end();
	trace_machine_suspend(PWR_EVENT_EXIT);
	return error;

 Recover_platform:
	if (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;

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