[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 <[email protected]>, 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);
}

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;
}

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)
		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
 *
 *	This function should be called after devices have been suspended.
 */
static int suspend_enter(suspend_state_t state)
{
	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) {
		if (!(suspend_test(TEST_CORE) || pm_wakeup_pending())) {
			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;

	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;

	error = suspend_enter(state);

 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)
{
	if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX)
		return enter_state(state);
	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 <[email protected]>, 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	}
	47
	48	bool valid_state(suspend_state_t state)
	49	{
	50	/*
	51	* All states need lowlevel support and need to be valid to the lowlevel
	52	* implementation, no valid callback implies that none are valid.
	53	*/
	54	return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
	55	}
	56
	57	/**
	58	* suspend_valid_only_mem - generic memory-only valid callback
	59	*
	60	* Platform drivers that implement mem suspend only and only need
	61	* to check for that in their .valid callback can use this instead
	62	* of rolling their own .valid callback.
	63	*/
	64	int suspend_valid_only_mem(suspend_state_t state)
	65	{
	66	return state == PM_SUSPEND_MEM;
	67	}
	68
	69	static int suspend_test(int level)
	70	{
	71	#ifdef CONFIG_PM_DEBUG
	72	if (pm_test_level == level) {
	73	printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
	74	mdelay(5000);
	75	return 1;
	76	}
	77	#endif /* !CONFIG_PM_DEBUG */
	78	return 0;
	79	}
	80
	81	/**
	82	* suspend_prepare - Do prep work before entering low-power state.
	83	*
	84	* This is common code that is called for each state that we're entering.
	85	* Run suspend notifiers, allocate a console and stop all processes.
	86	*/
	87	static int suspend_prepare(void)
	88	{
	89	int error;
	90
	91	if (!suspend_ops \|\| !suspend_ops->enter)
	92	return -EPERM;
	93
	94	pm_prepare_console();
	95
	96	error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
	97	if (error)
	98	goto Finish;
	99
	100	error = usermodehelper_disable();
	101	if (error)
	102	goto Finish;
	103
	104	error = suspend_freeze_processes();
	105	if (!error)
106	return 0;
107
108	suspend_thaw_processes();
109	usermodehelper_enable();
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	/**
129	* suspend_enter - enter the desired system sleep state.
130	* @state: state to enter
131	*
132	* This function should be called after devices have been suspended.
133	*/
134	static int suspend_enter(suspend_state_t state)
135	{
136	int error;
137
138	if (suspend_ops->prepare) {
139	error = suspend_ops->prepare();
140	if (error)
ce441011	141	goto Platform_finish;
a9d70523 RW	142	}
	143
	144	error = dpm_suspend_noirq(PMSG_SUSPEND);
	145	if (error) {
	146	printk(KERN_ERR "PM: Some devices failed to power down\n");
ce441011	147	goto Platform_finish;
a9d70523 RW	148	}
	149
	150	if (suspend_ops->prepare_late) {
	151	error = suspend_ops->prepare_late();
	152	if (error)
ce441011	153	goto Platform_wake;
a9d70523 RW	154	}
	155
	156	if (suspend_test(TEST_PLATFORM))
	157	goto Platform_wake;
	158
	159	error = disable_nonboot_cpus();
	160	if (error \|\| suspend_test(TEST_CPUS))
	161	goto Enable_cpus;
	162
	163	arch_suspend_disable_irqs();
	164	BUG_ON(!irqs_disabled());
	165
2e711c04	166	error = syscore_suspend();
a9d70523	167	if (!error) {
a2867e08	168	if (!(suspend_test(TEST_CORE) \|\| pm_wakeup_pending())) {
a9d70523	169	error = suspend_ops->enter(state);
c125e96f RW	170	events_check_enabled = false;
c125e96f RW	171	}
40dc166c	172	syscore_resume();
a9d70523 RW	173	}
	174
	175	arch_suspend_enable_irqs();
	176	BUG_ON(irqs_disabled());
	177
	178	Enable_cpus:
	179	enable_nonboot_cpus();
	180
	181	Platform_wake:
	182	if (suspend_ops->wake)
	183	suspend_ops->wake();
	184
a9d70523 RW	185	dpm_resume_noirq(PMSG_RESUME);
a9d70523 RW	186
ce441011	187	Platform_finish:
a9d70523 RW	188	if (suspend_ops->finish)
	189	suspend_ops->finish();
	190
	191	return error;
	192	}
	193
	194	/**
	195	* suspend_devices_and_enter - suspend devices and enter the desired system
	196	* sleep state.
	197	* @state: state to enter
	198	*/
	199	int suspend_devices_and_enter(suspend_state_t state)
	200	{
	201	int error;
	202
	203	if (!suspend_ops)
	204	return -ENOSYS;
	205
938cfed1	206	trace_machine_suspend(state);
a9d70523 RW	207	if (suspend_ops->begin) {
	208	error = suspend_ops->begin(state);
	209	if (error)
	210	goto Close;
	211	}
	212	suspend_console();
	213	suspend_test_start();
	214	error = dpm_suspend_start(PMSG_SUSPEND);
	215	if (error) {
	216	printk(KERN_ERR "PM: Some devices failed to suspend\n");
	217	goto Recover_platform;
	218	}
	219	suspend_test_finish("suspend devices");
	220	if (suspend_test(TEST_DEVICES))
	221	goto Recover_platform;
	222
3c431936	223	error = suspend_enter(state);
a9d70523 RW	224
	225	Resume_devices:
	226	suspend_test_start();
	227	dpm_resume_end(PMSG_RESUME);
	228	suspend_test_finish("resume devices");
	229	resume_console();
	230	Close:
	231	if (suspend_ops->end)
	232	suspend_ops->end();
938cfed1	233	trace_machine_suspend(PWR_EVENT_EXIT);
a9d70523 RW	234	return error;
	235
	236	Recover_platform:
	237	if (suspend_ops->recover)
	238	suspend_ops->recover();
	239	goto Resume_devices;
	240	}
	241
	242	/**
	243	* suspend_finish - Do final work before exiting suspend sequence.
	244	*
	245	* Call platform code to clean up, restart processes, and free the
	246	* console that we've allocated. This is not called for suspend-to-disk.
	247	*/
	248	static void suspend_finish(void)
	249	{
	250	suspend_thaw_processes();
	251	usermodehelper_enable();
	252	pm_notifier_call_chain(PM_POST_SUSPEND);
	253	pm_restore_console();
	254	}
	255
	256	/**
	257	* enter_state - Do common work of entering low-power state.
	258	* @state: pm_state structure for state we're entering.
	259	*
	260	* Make sure we're the only ones trying to enter a sleep state. Fail
	261	* if someone has beat us to it, since we don't want anything weird to
	262	* happen when we wake up.
	263	* Then, do the setup for suspend, enter the state, and cleaup (after
	264	* we've woken up).
	265	*/
	266	int enter_state(suspend_state_t state)
	267	{
	268	int error;
	269
	270	if (!valid_state(state))
	271	return -ENODEV;
	272
	273	if (!mutex_trylock(&pm_mutex))
	274	return -EBUSY;
	275
	276	printk(KERN_INFO "PM: Syncing filesystems ... ");
	277	sys_sync();
	278	printk("done.\n");
	279
	280	pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
	281	error = suspend_prepare();
	282	if (error)
	283	goto Unlock;
	284
	285	if (suspend_test(TEST_FREEZER))
	286	goto Finish;
	287
	288	pr_debug("PM: Entering %s sleep\n", pm_states[state]);
87186475	289	pm_restrict_gfp_mask();
a9d70523	290	error = suspend_devices_and_enter(state);
87186475	291	pm_restore_gfp_mask();
a9d70523 RW	292
	293	Finish:
	294	pr_debug("PM: Finishing wakeup.\n");
	295	suspend_finish();
	296	Unlock:
	297	mutex_unlock(&pm_mutex);
	298	return error;
	299	}
	300
	301	/**
	302	* pm_suspend - Externally visible function for suspending system.
	303	* @state: Enumerated value of state to enter.
	304	*
	305	* Determine whether or not value is within range, get state
	306	* structure, and enter (above).
	307	*/
	308	int pm_suspend(suspend_state_t state)
	309	{
	310	if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX)
	311	return enter_state(state);
	312	return -EINVAL;
	313	}
	314	EXPORT_SYMBOL(pm_suspend);