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