[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 <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 = sysdev_suspend(PMSG_SUSPEND);
	if (!error) {
		if (!(suspend_test(TEST_CORE) || pm_wakeup_pending())) {
			error = suspend_ops->enter(state);
			events_check_enabled = false;
		}
		sysdev_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();
	pm_restrict_gfp_mask();
	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;

	suspend_enter(state);

 Resume_devices:
	suspend_test_start();
	dpm_resume_end(PMSG_RESUME);
	suspend_test_finish("resume devices");
	pm_restore_gfp_mask();
	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]);
	error = suspend_devices_and_enter(state);

 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 <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>
938cfed1	25	#include <trace/events/power.h>
a9d70523 RW	26
	27	#include "power.h"
	28
	29	const char *const pm_states[PM_SUSPEND_MAX] = {
	30	[PM_SUSPEND_STANDBY] = "standby",
	31	[PM_SUSPEND_MEM] = "mem",
	32	};
	33
2f55ac07	34	static const struct platform_suspend_ops *suspend_ops;
a9d70523 RW	35
	36	/**
	37	* suspend_set_ops - Set the global suspend method table.
	38	* @ops: Pointer to ops structure.
	39	*/
2f55ac07	40	void suspend_set_ops(const struct platform_suspend_ops *ops)
a9d70523 RW	41	{
	42	mutex_lock(&pm_mutex);
	43	suspend_ops = ops;
	44	mutex_unlock(&pm_mutex);
	45	}
	46
	47	bool valid_state(suspend_state_t state)
	48	{
	49	/*
	50	* All states need lowlevel support and need to be valid to the lowlevel
	51	* implementation, no valid callback implies that none are valid.
	52	*/
	53	return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
	54	}
	55
	56	/**
	57	* suspend_valid_only_mem - generic memory-only valid callback
	58	*
	59	* Platform drivers that implement mem suspend only and only need
	60	* to check for that in their .valid callback can use this instead
	61	* of rolling their own .valid callback.
	62	*/
	63	int suspend_valid_only_mem(suspend_state_t state)
	64	{
	65	return state == PM_SUSPEND_MEM;
	66	}
	67
	68	static int suspend_test(int level)
	69	{
	70	#ifdef CONFIG_PM_DEBUG
	71	if (pm_test_level == level) {
	72	printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
	73	mdelay(5000);
	74	return 1;
	75	}
	76	#endif /* !CONFIG_PM_DEBUG */
	77	return 0;
	78	}
	79
	80	/**
	81	* suspend_prepare - Do prep work before entering low-power state.
	82	*
	83	* This is common code that is called for each state that we're entering.
	84	* Run suspend notifiers, allocate a console and stop all processes.
	85	*/
	86	static int suspend_prepare(void)
	87	{
	88	int error;
	89
	90	if (!suspend_ops \|\| !suspend_ops->enter)
	91	return -EPERM;
	92
	93	pm_prepare_console();
	94
	95	error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
	96	if (error)
	97	goto Finish;
	98
	99	error = usermodehelper_disable();
	100	if (error)
	101	goto Finish;
	102
	103	error = suspend_freeze_processes();
	104	if (!error)
105	return 0;
106
107	suspend_thaw_processes();
108	usermodehelper_enable();
109	Finish:
110	pm_notifier_call_chain(PM_POST_SUSPEND);
111	pm_restore_console();
112	return error;
113	}
114
115	/* default implementation */
116	void __attribute__ ((weak)) arch_suspend_disable_irqs(void)
117	{
118	local_irq_disable();
119	}
120
121	/* default implementation */
122	void __attribute__ ((weak)) arch_suspend_enable_irqs(void)
123	{
124	local_irq_enable();
125	}
126
127	/**
128	* suspend_enter - enter the desired system sleep state.
129	* @state: state to enter
130	*
131	* This function should be called after devices have been suspended.
132	*/
133	static int suspend_enter(suspend_state_t state)
134	{
135	int error;
136
137	if (suspend_ops->prepare) {
138	error = suspend_ops->prepare();
139	if (error)
ce441011	140	goto Platform_finish;
a9d70523 RW	141	}
	142
	143	error = dpm_suspend_noirq(PMSG_SUSPEND);
	144	if (error) {
	145	printk(KERN_ERR "PM: Some devices failed to power down\n");
ce441011	146	goto Platform_finish;
a9d70523 RW	147	}
	148
	149	if (suspend_ops->prepare_late) {
	150	error = suspend_ops->prepare_late();
	151	if (error)
ce441011	152	goto Platform_wake;
a9d70523 RW	153	}
	154
	155	if (suspend_test(TEST_PLATFORM))
	156	goto Platform_wake;
	157
	158	error = disable_nonboot_cpus();
	159	if (error \|\| suspend_test(TEST_CPUS))
	160	goto Enable_cpus;
	161
	162	arch_suspend_disable_irqs();
	163	BUG_ON(!irqs_disabled());
	164
	165	error = sysdev_suspend(PMSG_SUSPEND);
	166	if (!error) {
a2867e08	167	if (!(suspend_test(TEST_CORE) \|\| pm_wakeup_pending())) {
a9d70523	168	error = suspend_ops->enter(state);
c125e96f RW	169	events_check_enabled = false;
c125e96f RW	170	}
a9d70523 RW	171	sysdev_resume();
	172	}
	173
	174	arch_suspend_enable_irqs();
	175	BUG_ON(irqs_disabled());
	176
	177	Enable_cpus:
	178	enable_nonboot_cpus();
	179
	180	Platform_wake:
	181	if (suspend_ops->wake)
	182	suspend_ops->wake();
	183
a9d70523 RW	184	dpm_resume_noirq(PMSG_RESUME);
a9d70523 RW	185
ce441011	186	Platform_finish:
a9d70523 RW	187	if (suspend_ops->finish)
	188	suspend_ops->finish();
	189
	190	return error;
	191	}
	192
	193	/**
	194	* suspend_devices_and_enter - suspend devices and enter the desired system
	195	* sleep state.
	196	* @state: state to enter
	197	*/
	198	int suspend_devices_and_enter(suspend_state_t state)
	199	{
	200	int error;
	201
	202	if (!suspend_ops)
	203	return -ENOSYS;
	204
938cfed1	205	trace_machine_suspend(state);
a9d70523 RW	206	if (suspend_ops->begin) {
	207	error = suspend_ops->begin(state);
	208	if (error)
	209	goto Close;
	210	}
	211	suspend_console();
c9e664f1	212	pm_restrict_gfp_mask();
a9d70523 RW	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
	223	suspend_enter(state);
	224
	225	Resume_devices:
	226	suspend_test_start();
	227	dpm_resume_end(PMSG_RESUME);
	228	suspend_test_finish("resume devices");
c9e664f1	229	pm_restore_gfp_mask();
a9d70523 RW	230	resume_console();
	231	Close:
	232	if (suspend_ops->end)
	233	suspend_ops->end();
938cfed1	234	trace_machine_suspend(PWR_EVENT_EXIT);
a9d70523 RW	235	return error;
	236
	237	Recover_platform:
	238	if (suspend_ops->recover)
	239	suspend_ops->recover();
	240	goto Resume_devices;
	241	}
	242
	243	/**
	244	* suspend_finish - Do final work before exiting suspend sequence.
	245	*
	246	* Call platform code to clean up, restart processes, and free the
	247	* console that we've allocated. This is not called for suspend-to-disk.
	248	*/
	249	static void suspend_finish(void)
	250	{
	251	suspend_thaw_processes();
	252	usermodehelper_enable();
	253	pm_notifier_call_chain(PM_POST_SUSPEND);
	254	pm_restore_console();
	255	}
	256
	257	/**
	258	* enter_state - Do common work of entering low-power state.
	259	* @state: pm_state structure for state we're entering.
	260	*
	261	* Make sure we're the only ones trying to enter a sleep state. Fail
	262	* if someone has beat us to it, since we don't want anything weird to
	263	* happen when we wake up.
	264	* Then, do the setup for suspend, enter the state, and cleaup (after
	265	* we've woken up).
	266	*/
	267	int enter_state(suspend_state_t state)
	268	{
	269	int error;
	270
	271	if (!valid_state(state))
	272	return -ENODEV;
	273
	274	if (!mutex_trylock(&pm_mutex))
	275	return -EBUSY;
	276
	277	printk(KERN_INFO "PM: Syncing filesystems ... ");
	278	sys_sync();
	279	printk("done.\n");
	280
	281	pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
	282	error = suspend_prepare();
	283	if (error)
	284	goto Unlock;
	285
	286	if (suspend_test(TEST_FREEZER))
	287	goto Finish;
	288
	289	pr_debug("PM: Entering %s sleep\n", pm_states[state]);
	290	error = suspend_devices_and_enter(state);
	291
	292	Finish:
	293	pr_debug("PM: Finishing wakeup.\n");
	294	suspend_finish();
	295	Unlock:
	296	mutex_unlock(&pm_mutex);
	297	return error;
	298	}
299
300	/**
301	* pm_suspend - Externally visible function for suspending system.
302	* @state: Enumerated value of state to enter.
303	*
304	* Determine whether or not value is within range, get state
305	* structure, and enter (above).
306	*/
307	int pm_suspend(suspend_state_t state)
308	{
309	if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX)
310	return enter_state(state);
311	return -EINVAL;
312	}
313	EXPORT_SYMBOL(pm_suspend);