[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/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:	Pointer to ops structure.
 */
void suspend_set_ops(const struct platform_suspend_ops *ops)
{
	mutex_lock(&pm_mutex);
	suspend_ops = ops;
	mutex_unlock(&pm_mutex);
}
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 - Do prep work before entering low-power state.
 *
 *	This is common code that is called for each state that we're entering.
 *	Run suspend notifiers, allocate a console and stop all 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 = usermodehelper_disable();
	if (error)
		goto Finish;

	error = suspend_freeze_processes();
	if (error) {
		suspend_stats.failed_freeze++;
		dpm_save_failed_step(SUSPEND_FREEZE);
	} else
		return 0;

	suspend_thaw_processes();
	usermodehelper_enable();
 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 - enter the desired system sleep state.
 * @state: State to enter
 * @wakeup: Returns information that suspend should not be entered again.
 *
 * 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_noirq(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_noirq(PMSG_RESUME);

 Platform_finish:
	if (suspend_ops->finish)
		suspend_ops->finish();

	return error;
}

/**
 *	suspend_devices_and_enter - suspend devices and enter the desired system
 *				    sleep state.
 *	@state:		  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 - Do final work before exiting suspend sequence.
 *
 *	Call platform code to clean up, restart processes, and free the
 *	console that we've allocated. This is not called for suspend-to-disk.
 */
static void suspend_finish(void)
{
	suspend_thaw_processes();
	usermodehelper_enable();
	pm_notifier_call_chain(PM_POST_SUSPEND);
	pm_restore_console();
}

/**
 *	enter_state - Do common work of entering low-power state.
 *	@state:		pm_state structure for state we're entering.
 *
 *	Make sure we're the only ones trying to enter a sleep state. Fail
 *	if someone has beat us to it, since we don't want anything weird to
 *	happen when we wake up.
 *	Then, do the setup for suspend, enter the state, and cleaup (after
 *	we've woken up).
 */
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 system.
 *	@state:		Enumerated value of state to enter.
 *
 *	Determine whether or not value is within range, get state
 *	structure, and enter (above).
 */
int pm_suspend(suspend_state_t state)
{
	int ret;
	if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX) {
		ret = enter_state(state);
		if (ret) {
			suspend_stats.fail++;
			dpm_save_failed_errno(ret);
		} else
			suspend_stats.success++;
		return ret;
	}
	return -EINVAL;
}
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>
	24	#include <linux/suspend.h>
40dc166c	25	#include <linux/syscore_ops.h>
938cfed1	26	#include <trace/events/power.h>
a9d70523 RW	27
	28	#include "power.h"
	29
	30	const char *const pm_states[PM_SUSPEND_MAX] = {
	31	[PM_SUSPEND_STANDBY] = "standby",
	32	[PM_SUSPEND_MEM] = "mem",
	33	};
	34
2f55ac07	35	static const struct platform_suspend_ops *suspend_ops;
a9d70523 RW	36
	37	/**
	38	* suspend_set_ops - Set the global suspend method table.
	39	* @ops: Pointer to ops structure.
	40	*/
2f55ac07	41	void suspend_set_ops(const struct platform_suspend_ops *ops)
a9d70523 RW	42	{
	43	mutex_lock(&pm_mutex);
	44	suspend_ops = ops;
	45	mutex_unlock(&pm_mutex);
	46	}
a5e4fd87	47	EXPORT_SYMBOL_GPL(suspend_set_ops);
a9d70523 RW	48
	49	bool valid_state(suspend_state_t state)
	50	{
	51	/*
	52	* All states need lowlevel support and need to be valid to the lowlevel
	53	* implementation, no valid callback implies that none are valid.
	54	*/
	55	return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
	56	}
	57
	58	/**
	59	* suspend_valid_only_mem - generic memory-only valid callback
	60	*
	61	* Platform drivers that implement mem suspend only and only need
	62	* to check for that in their .valid callback can use this instead
	63	* of rolling their own .valid callback.
	64	*/
	65	int suspend_valid_only_mem(suspend_state_t state)
	66	{
	67	return state == PM_SUSPEND_MEM;
	68	}
a5e4fd87	69	EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
a9d70523 RW	70
	71	static int suspend_test(int level)
	72	{
	73	#ifdef CONFIG_PM_DEBUG
	74	if (pm_test_level == level) {
	75	printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
	76	mdelay(5000);
	77	return 1;
	78	}
	79	#endif /* !CONFIG_PM_DEBUG */
	80	return 0;
	81	}
	82
	83	/**
	84	* suspend_prepare - Do prep work before entering low-power state.
	85	*
	86	* This is common code that is called for each state that we're entering.
	87	* Run suspend notifiers, allocate a console and stop all processes.
	88	*/
	89	static int suspend_prepare(void)
	90	{
	91	int error;
	92
	93	if (!suspend_ops \|\| !suspend_ops->enter)
	94	return -EPERM;
	95
	96	pm_prepare_console();
	97
	98	error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
	99	if (error)
	100	goto Finish;
	101
	102	error = usermodehelper_disable();
	103	if (error)
	104	goto Finish;
	105
	106	error = suspend_freeze_processes();
2a77c46d SL	107	if (error) {
	108	suspend_stats.failed_freeze++;
	109	dpm_save_failed_step(SUSPEND_FREEZE);
	110	} else
a9d70523 RW	111	return 0;
	112
	113	suspend_thaw_processes();
	114	usermodehelper_enable();
	115	Finish:
	116	pm_notifier_call_chain(PM_POST_SUSPEND);
	117	pm_restore_console();
	118	return error;
	119	}
	120
	121	/* default implementation */
	122	void __attribute__ ((weak)) arch_suspend_disable_irqs(void)
	123	{
	124	local_irq_disable();
	125	}
	126
	127	/* default implementation */
	128	void __attribute__ ((weak)) arch_suspend_enable_irqs(void)
	129	{
	130	local_irq_enable();
	131	}
	132
	133	/**
3b5fe852 MH	134	* suspend_enter - enter the desired system sleep state.
	135	* @state: State to enter
	136	* @wakeup: Returns information that suspend should not be entered again.
a9d70523	137	*
3b5fe852	138	* This function should be called after devices have been suspended.
a9d70523	139	*/
3b5fe852	140	static int suspend_enter(suspend_state_t state, bool *wakeup)
a9d70523 RW	141	{
	142	int error;
	143
	144	if (suspend_ops->prepare) {
	145	error = suspend_ops->prepare();
	146	if (error)
ce441011	147	goto Platform_finish;
a9d70523 RW	148	}
	149
	150	error = dpm_suspend_noirq(PMSG_SUSPEND);
	151	if (error) {
	152	printk(KERN_ERR "PM: Some devices failed to power down\n");
ce441011	153	goto Platform_finish;
a9d70523 RW	154	}
	155
	156	if (suspend_ops->prepare_late) {
	157	error = suspend_ops->prepare_late();
	158	if (error)
ce441011	159	goto Platform_wake;
a9d70523 RW	160	}
	161
	162	if (suspend_test(TEST_PLATFORM))
	163	goto Platform_wake;
	164
	165	error = disable_nonboot_cpus();
	166	if (error \|\| suspend_test(TEST_CPUS))
	167	goto Enable_cpus;
	168
	169	arch_suspend_disable_irqs();
	170	BUG_ON(!irqs_disabled());
	171
2e711c04	172	error = syscore_suspend();
a9d70523	173	if (!error) {
3b5fe852 MH	174	*wakeup = pm_wakeup_pending();
3b5fe852 MH	175	if (!(suspend_test(TEST_CORE) \|\| *wakeup)) {
a9d70523	176	error = suspend_ops->enter(state);
c125e96f RW	177	events_check_enabled = false;
c125e96f RW	178	}
40dc166c	179	syscore_resume();
a9d70523 RW	180	}
	181
	182	arch_suspend_enable_irqs();
	183	BUG_ON(irqs_disabled());
	184
	185	Enable_cpus:
	186	enable_nonboot_cpus();
	187
	188	Platform_wake:
	189	if (suspend_ops->wake)
	190	suspend_ops->wake();
	191
a9d70523 RW	192	dpm_resume_noirq(PMSG_RESUME);
a9d70523 RW	193
ce441011	194	Platform_finish:
a9d70523 RW	195	if (suspend_ops->finish)
	196	suspend_ops->finish();
	197
	198	return error;
	199	}
	200
	201	/**
	202	* suspend_devices_and_enter - suspend devices and enter the desired system
	203	* sleep state.
	204	* @state: state to enter
	205	*/
	206	int suspend_devices_and_enter(suspend_state_t state)
	207	{
	208	int error;
3b5fe852	209	bool wakeup = false;
a9d70523 RW	210
	211	if (!suspend_ops)
	212	return -ENOSYS;
	213
938cfed1	214	trace_machine_suspend(state);
a9d70523 RW	215	if (suspend_ops->begin) {
	216	error = suspend_ops->begin(state);
	217	if (error)
	218	goto Close;
	219	}
	220	suspend_console();
	221	suspend_test_start();
	222	error = dpm_suspend_start(PMSG_SUSPEND);
	223	if (error) {
	224	printk(KERN_ERR "PM: Some devices failed to suspend\n");
	225	goto Recover_platform;
	226	}
	227	suspend_test_finish("suspend devices");
	228	if (suspend_test(TEST_DEVICES))
	229	goto Recover_platform;
	230
3b5fe852 MH	231	do {
	232	error = suspend_enter(state, &wakeup);
	233	} while (!error && !wakeup
	234	&& suspend_ops->suspend_again && suspend_ops->suspend_again());
a9d70523 RW	235
	236	Resume_devices:
	237	suspend_test_start();
	238	dpm_resume_end(PMSG_RESUME);
	239	suspend_test_finish("resume devices");
	240	resume_console();
	241	Close:
	242	if (suspend_ops->end)
	243	suspend_ops->end();
938cfed1	244	trace_machine_suspend(PWR_EVENT_EXIT);
a9d70523 RW	245	return error;
	246
	247	Recover_platform:
	248	if (suspend_ops->recover)
	249	suspend_ops->recover();
	250	goto Resume_devices;
	251	}
	252
	253	/**
	254	* suspend_finish - Do final work before exiting suspend sequence.
	255	*
	256	* Call platform code to clean up, restart processes, and free the
	257	* console that we've allocated. This is not called for suspend-to-disk.
	258	*/
	259	static void suspend_finish(void)
	260	{
	261	suspend_thaw_processes();
	262	usermodehelper_enable();
	263	pm_notifier_call_chain(PM_POST_SUSPEND);
	264	pm_restore_console();
	265	}
	266
	267	/**
	268	* enter_state - Do common work of entering low-power state.
	269	* @state: pm_state structure for state we're entering.
	270	*
	271	* Make sure we're the only ones trying to enter a sleep state. Fail
	272	* if someone has beat us to it, since we don't want anything weird to
	273	* happen when we wake up.
	274	* Then, do the setup for suspend, enter the state, and cleaup (after
	275	* we've woken up).
	276	*/
	277	int enter_state(suspend_state_t state)
	278	{
	279	int error;
	280
	281	if (!valid_state(state))
	282	return -ENODEV;
	283
	284	if (!mutex_trylock(&pm_mutex))
	285	return -EBUSY;
	286
	287	printk(KERN_INFO "PM: Syncing filesystems ... ");
	288	sys_sync();
	289	printk("done.\n");
	290
	291	pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
	292	error = suspend_prepare();
	293	if (error)
	294	goto Unlock;
	295
	296	if (suspend_test(TEST_FREEZER))
	297	goto Finish;
	298
	299	pr_debug("PM: Entering %s sleep\n", pm_states[state]);
87186475	300	pm_restrict_gfp_mask();
a9d70523	301	error = suspend_devices_and_enter(state);
87186475	302	pm_restore_gfp_mask();
a9d70523 RW	303
	304	Finish:
	305	pr_debug("PM: Finishing wakeup.\n");
	306	suspend_finish();
	307	Unlock:
	308	mutex_unlock(&pm_mutex);
	309	return error;
	310	}
	311
	312	/**
	313	* pm_suspend - Externally visible function for suspending system.
	314	* @state: Enumerated value of state to enter.
	315	*
	316	* Determine whether or not value is within range, get state
	317	* structure, and enter (above).
	318	*/
	319	int pm_suspend(suspend_state_t state)
	320	{
2a77c46d SL	321	int ret;
	322	if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX) {
	323	ret = enter_state(state);
	324	if (ret) {
	325	suspend_stats.fail++;
	326	dpm_save_failed_errno(ret);
	327	} else
	328	suspend_stats.success++;
	329	return ret;
	330	}
a9d70523 RW	331	return -EINVAL;
	332	}
	333	EXPORT_SYMBOL(pm_suspend);