[net-next-2.6.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 "power.h"

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

static struct platform_suspend_ops *suspend_ops;

/**
 *	suspend_set_ops - Set the global suspend method table.
 *	@ops:	Pointer to ops structure.
 */
void suspend_set_ops(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)
			return error;
	}

	error = dpm_suspend_noirq(PMSG_SUSPEND);
	if (error) {
		printk(KERN_ERR "PM: Some devices failed to power down\n");
		goto Platfrom_finish;
	}

	if (suspend_ops->prepare_late) {
		error = suspend_ops->prepare_late();
		if (error)
			goto Power_up_devices;
	}

	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))
			error = suspend_ops->enter(state);
		sysdev_resume();
	}

	arch_suspend_enable_irqs();
	BUG_ON(irqs_disabled());

 Enable_cpus:
	enable_nonboot_cpus();

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

 Power_up_devices:
	dpm_resume_noirq(PMSG_RESUME);

 Platfrom_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;
	gfp_t saved_mask;

	if (!suspend_ops)
		return -ENOSYS;

	if (suspend_ops->begin) {
		error = suspend_ops->begin(state);
		if (error)
			goto Close;
	}
	suspend_console();
	saved_mask = clear_gfp_allowed_mask(GFP_IOFS);
	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");
	set_gfp_allowed_mask(saved_mask);
	resume_console();
 Close:
	if (suspend_ops->end)
		suspend_ops->end();
	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>
a9d70523 RW	25
	26	#include "power.h"
	27
	28	const char *const pm_states[PM_SUSPEND_MAX] = {
	29	[PM_SUSPEND_STANDBY] = "standby",
	30	[PM_SUSPEND_MEM] = "mem",
	31	};
	32
	33	static struct platform_suspend_ops *suspend_ops;
	34
	35	/**
	36	* suspend_set_ops - Set the global suspend method table.
	37	* @ops: Pointer to ops structure.
	38	*/
	39	void suspend_set_ops(struct platform_suspend_ops *ops)
	40	{
	41	mutex_lock(&pm_mutex);
	42	suspend_ops = ops;
	43	mutex_unlock(&pm_mutex);
	44	}
	45
	46	bool valid_state(suspend_state_t state)
	47	{
	48	/*
	49	* All states need lowlevel support and need to be valid to the lowlevel
	50	* implementation, no valid callback implies that none are valid.
	51	*/
	52	return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
	53	}
	54
	55	/**
	56	* suspend_valid_only_mem - generic memory-only valid callback
	57	*
	58	* Platform drivers that implement mem suspend only and only need
	59	* to check for that in their .valid callback can use this instead
	60	* of rolling their own .valid callback.
	61	*/
	62	int suspend_valid_only_mem(suspend_state_t state)
	63	{
	64	return state == PM_SUSPEND_MEM;
	65	}
	66
	67	static int suspend_test(int level)
	68	{
	69	#ifdef CONFIG_PM_DEBUG
	70	if (pm_test_level == level) {
	71	printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
	72	mdelay(5000);
	73	return 1;
	74	}
	75	#endif /* !CONFIG_PM_DEBUG */
	76	return 0;
	77	}
	78
	79	/**
	80	* suspend_prepare - Do prep work before entering low-power state.
	81	*
	82	* This is common code that is called for each state that we're entering.
	83	* Run suspend notifiers, allocate a console and stop all processes.
	84	*/
	85	static int suspend_prepare(void)
	86	{
	87	int error;
	88
89	if (!suspend_ops \|\| !suspend_ops->enter)
90	return -EPERM;
91
92	pm_prepare_console();
93
94	error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
95	if (error)
96	goto Finish;
97
98	error = usermodehelper_disable();
99	if (error)
100	goto Finish;
101
102	error = suspend_freeze_processes();
103	if (!error)
104	return 0;
105
106	suspend_thaw_processes();
107	usermodehelper_enable();
108	Finish:
109	pm_notifier_call_chain(PM_POST_SUSPEND);
110	pm_restore_console();
111	return error;
112	}
113
114	/* default implementation */
115	void __attribute__ ((weak)) arch_suspend_disable_irqs(void)
116	{
117	local_irq_disable();
118	}
119
120	/* default implementation */
121	void __attribute__ ((weak)) arch_suspend_enable_irqs(void)
122	{
123	local_irq_enable();
124	}
125
126	/**
127	* suspend_enter - enter the desired system sleep state.
128	* @state: state to enter
129	*
130	* This function should be called after devices have been suspended.
131	*/
132	static int suspend_enter(suspend_state_t state)
133	{
134	int error;
135
136	if (suspend_ops->prepare) {
137	error = suspend_ops->prepare();
138	if (error)
139	return error;
140	}
141
142	error = dpm_suspend_noirq(PMSG_SUSPEND);
143	if (error) {
144	printk(KERN_ERR "PM: Some devices failed to power down\n");
145	goto Platfrom_finish;
146	}
147
148	if (suspend_ops->prepare_late) {
149	error = suspend_ops->prepare_late();
150	if (error)
151	goto Power_up_devices;
152	}
153
154	if (suspend_test(TEST_PLATFORM))
155	goto Platform_wake;
156
157	error = disable_nonboot_cpus();
158	if (error \|\| suspend_test(TEST_CPUS))
159	goto Enable_cpus;
160
161	arch_suspend_disable_irqs();
162	BUG_ON(!irqs_disabled());
163
164	error = sysdev_suspend(PMSG_SUSPEND);
165	if (!error) {
166	if (!suspend_test(TEST_CORE))
167	error = suspend_ops->enter(state);
168	sysdev_resume();
169	}
170
171	arch_suspend_enable_irqs();
172	BUG_ON(irqs_disabled());
173
174	Enable_cpus:
175	enable_nonboot_cpus();
176
177	Platform_wake:
178	if (suspend_ops->wake)
179	suspend_ops->wake();
180
181	Power_up_devices:
182	dpm_resume_noirq(PMSG_RESUME);
183
184	Platfrom_finish:
185	if (suspend_ops->finish)
186	suspend_ops->finish();
187
188	return error;
189	}
190
191	/**
192	* suspend_devices_and_enter - suspend devices and enter the desired system
193	* sleep state.
194	* @state: state to enter
195	*/
196	int suspend_devices_and_enter(suspend_state_t state)
197	{
198	int error;
452aa699	199	gfp_t saved_mask;
a9d70523 RW	200
	201	if (!suspend_ops)
	202	return -ENOSYS;
	203
	204	if (suspend_ops->begin) {
	205	error = suspend_ops->begin(state);
	206	if (error)
	207	goto Close;
	208	}
	209	suspend_console();
452aa699	210	saved_mask = clear_gfp_allowed_mask(GFP_IOFS);
a9d70523 RW	211	suspend_test_start();
	212	error = dpm_suspend_start(PMSG_SUSPEND);
	213	if (error) {
	214	printk(KERN_ERR "PM: Some devices failed to suspend\n");
	215	goto Recover_platform;
	216	}
	217	suspend_test_finish("suspend devices");
	218	if (suspend_test(TEST_DEVICES))
	219	goto Recover_platform;
	220
	221	suspend_enter(state);
	222
	223	Resume_devices:
	224	suspend_test_start();
	225	dpm_resume_end(PMSG_RESUME);
	226	suspend_test_finish("resume devices");
452aa699	227	set_gfp_allowed_mask(saved_mask);
a9d70523 RW	228	resume_console();
	229	Close:
	230	if (suspend_ops->end)
	231	suspend_ops->end();
	232	return error;
	233
	234	Recover_platform:
	235	if (suspend_ops->recover)
	236	suspend_ops->recover();
	237	goto Resume_devices;
	238	}
	239
	240	/**
	241	* suspend_finish - Do final work before exiting suspend sequence.
	242	*
	243	* Call platform code to clean up, restart processes, and free the
	244	* console that we've allocated. This is not called for suspend-to-disk.
	245	*/
	246	static void suspend_finish(void)
	247	{
	248	suspend_thaw_processes();
	249	usermodehelper_enable();
	250	pm_notifier_call_chain(PM_POST_SUSPEND);
	251	pm_restore_console();
	252	}
	253
	254	/**
	255	* enter_state - Do common work of entering low-power state.
	256	* @state: pm_state structure for state we're entering.
	257	*
	258	* Make sure we're the only ones trying to enter a sleep state. Fail
	259	* if someone has beat us to it, since we don't want anything weird to
	260	* happen when we wake up.
	261	* Then, do the setup for suspend, enter the state, and cleaup (after
	262	* we've woken up).
	263	*/
	264	int enter_state(suspend_state_t state)
	265	{
	266	int error;
	267
	268	if (!valid_state(state))
	269	return -ENODEV;
	270
	271	if (!mutex_trylock(&pm_mutex))
	272	return -EBUSY;
	273
	274	printk(KERN_INFO "PM: Syncing filesystems ... ");
	275	sys_sync();
	276	printk("done.\n");
	277
	278	pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
	279	error = suspend_prepare();
	280	if (error)
	281	goto Unlock;
	282
	283	if (suspend_test(TEST_FREEZER))
	284	goto Finish;
	285
	286	pr_debug("PM: Entering %s sleep\n", pm_states[state]);
	287	error = suspend_devices_and_enter(state);
	288
	289	Finish:
	290	pr_debug("PM: Finishing wakeup.\n");
	291	suspend_finish();
292	Unlock:
293	mutex_unlock(&pm_mutex);
294	return error;
295	}
296
297	/**
298	* pm_suspend - Externally visible function for suspending system.
299	* @state: Enumerated value of state to enter.
300	*
301	* Determine whether or not value is within range, get state
302	* structure, and enter (above).
303	*/
304	int pm_suspend(suspend_state_t state)
305	{
306	if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX)
307	return enter_state(state);
308	return -EINVAL;
309	}
310	EXPORT_SYMBOL(pm_suspend);