[deliverable/linux.git] / kernel / power / main.c

/*
 * kernel/power/main.c - PM subsystem core functionality.
 *
 * Copyright (c) 2003 Patrick Mochel
 * Copyright (c) 2003 Open Source Development Lab
 * 
 * This file is released under the GPLv2
 *
 */

#include <linux/module.h>
#include <linux/suspend.h>
#include <linux/kobject.h>
#include <linux/string.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/pm.h>
#include <linux/console.h>
#include <linux/cpu.h>
#include <linux/resume-trace.h>
#include <linux/freezer.h>
#include <linux/vmstat.h>

#include "power.h"

/*This is just an arbitrary number */
#define FREE_PAGE_NUMBER (100)

DEFINE_MUTEX(pm_mutex);

struct pm_ops *pm_ops;
suspend_disk_method_t pm_disk_mode = PM_DISK_SHUTDOWN;

/**
 *	pm_set_ops - Set the global power method table. 
 *	@ops:	Pointer to ops structure.
 */

void pm_set_ops(struct pm_ops * ops)
{
	mutex_lock(&pm_mutex);
	pm_ops = ops;
	if (ops && ops->pm_disk_mode != PM_DISK_INVALID) {
		pm_disk_mode = ops->pm_disk_mode;
	} else
		pm_disk_mode = PM_DISK_SHUTDOWN;
	mutex_unlock(&pm_mutex);
}

static inline void pm_finish(suspend_state_t state)
{
	if (pm_ops->finish)
		pm_ops->finish(state);
}

/**
 *	suspend_prepare - Do prep work before entering low-power state.
 *	@state:		State we're entering.
 *
 *	This is common code that is called for each state that we're 
 *	entering. Allocate a console, stop all processes, then make sure
 *	the platform can enter the requested state.
 */

static int suspend_prepare(suspend_state_t state)
{
	int error;
	unsigned int free_pages;

	if (!pm_ops || !pm_ops->enter)
		return -EPERM;

	pm_prepare_console();

	if (freeze_processes()) {
		error = -EAGAIN;
		goto Thaw;
	}

	if ((free_pages = global_page_state(NR_FREE_PAGES))
			< FREE_PAGE_NUMBER) {
		pr_debug("PM: free some memory\n");
		shrink_all_memory(FREE_PAGE_NUMBER - free_pages);
		if (nr_free_pages() < FREE_PAGE_NUMBER) {
			error = -ENOMEM;
			printk(KERN_ERR "PM: No enough memory\n");
			goto Thaw;
		}
	}

	if (pm_ops->prepare) {
		if ((error = pm_ops->prepare(state)))
			goto Thaw;
	}

	suspend_console();
	error = device_suspend(PMSG_SUSPEND);
	if (error) {
		printk(KERN_ERR "Some devices failed to suspend\n");
		goto Resume_devices;
	}
	error = disable_nonboot_cpus();
	if (!error)
		return 0;

	enable_nonboot_cpus();
 Resume_devices:
	pm_finish(state);
	device_resume();
	resume_console();
 Thaw:
	thaw_processes();
	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();
}

int suspend_enter(suspend_state_t state)
{
	int error = 0;

	arch_suspend_disable_irqs();
	BUG_ON(!irqs_disabled());

	if ((error = device_power_down(PMSG_SUSPEND))) {
		printk(KERN_ERR "Some devices failed to power down\n");
		goto Done;
	}
	error = pm_ops->enter(state);
	device_power_up();
 Done:
	arch_suspend_enable_irqs();
	BUG_ON(irqs_disabled());
	return error;
}


/**
 *	suspend_finish - Do final work before exiting suspend sequence.
 *	@state:		State we're coming out of.
 *
 *	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(suspend_state_t state)
{
	enable_nonboot_cpus();
	pm_finish(state);
	device_resume();
	resume_console();
	thaw_processes();
	pm_restore_console();
}


static const char * const pm_states[PM_SUSPEND_MAX] = {
	[PM_SUSPEND_STANDBY]	= "standby",
	[PM_SUSPEND_MEM]	= "mem",
#ifdef CONFIG_SOFTWARE_SUSPEND
	[PM_SUSPEND_DISK]	= "disk",
#endif
};

static inline int valid_state(suspend_state_t state)
{
	/* Suspend-to-disk does not really need low-level support.
	 * It can work with reboot if needed. */
	if (state == PM_SUSPEND_DISK)
		return 1;

	/* all other states need lowlevel support and need to be
	 * valid to the lowlevel implementation, no valid callback
	 * implies that all are valid. */
	if (!pm_ops || (pm_ops->valid && !pm_ops->valid(state)))
		return 0;
	return 1;
}


/**
 *	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).
 */

static int enter_state(suspend_state_t state)
{
	int error;

	if (!valid_state(state))
		return -ENODEV;
	if (!mutex_trylock(&pm_mutex))
		return -EBUSY;

	if (state == PM_SUSPEND_DISK) {
		error = pm_suspend_disk();
		goto Unlock;
	}

	pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
	if ((error = suspend_prepare(state)))
		goto Unlock;

	pr_debug("PM: Entering %s sleep\n", pm_states[state]);
	error = suspend_enter(state);

	pr_debug("PM: Finishing wakeup.\n");
	suspend_finish(state);
 Unlock:
	mutex_unlock(&pm_mutex);
	return error;
}

/*
 * This is main interface to the outside world. It needs to be
 * called from process context.
 */
int software_suspend(void)
{
	return enter_state(PM_SUSPEND_DISK);
}


/**
 *	pm_suspend - Externally visible function for suspending system.
 *	@state:		Enumarted 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);

decl_subsys(power,NULL,NULL);


/**
 *	state - control system power state.
 *
 *	show() returns what states are supported, which is hard-coded to
 *	'standby' (Power-On Suspend), 'mem' (Suspend-to-RAM), and
 *	'disk' (Suspend-to-Disk).
 *
 *	store() accepts one of those strings, translates it into the 
 *	proper enumerated value, and initiates a suspend transition.
 */

static ssize_t state_show(struct subsystem * subsys, char * buf)
{
	int i;
	char * s = buf;

	for (i = 0; i < PM_SUSPEND_MAX; i++) {
		if (pm_states[i] && valid_state(i))
			s += sprintf(s,"%s ", pm_states[i]);
	}
	s += sprintf(s,"\n");
	return (s - buf);
}

static ssize_t state_store(struct subsystem * subsys, const char * buf, size_t n)
{
	suspend_state_t state = PM_SUSPEND_STANDBY;
	const char * const *s;
	char *p;
	int error;
	int len;

	p = memchr(buf, '\n', n);
	len = p ? p - buf : n;

	for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++) {
		if (*s && !strncmp(buf, *s, len))
			break;
	}
	if (state < PM_SUSPEND_MAX && *s)
		error = enter_state(state);
	else
		error = -EINVAL;
	return error ? error : n;
}

power_attr(state);

#ifdef CONFIG_PM_TRACE
int pm_trace_enabled;

static ssize_t pm_trace_show(struct subsystem * subsys, char * buf)
{
	return sprintf(buf, "%d\n", pm_trace_enabled);
}

static ssize_t
pm_trace_store(struct subsystem * subsys, const char * buf, size_t n)
{
	int val;

	if (sscanf(buf, "%d", &val) == 1) {
		pm_trace_enabled = !!val;
		return n;
	}
	return -EINVAL;
}

power_attr(pm_trace);

static struct attribute * g[] = {
	&state_attr.attr,
	&pm_trace_attr.attr,
	NULL,
};
#else
static struct attribute * g[] = {
	&state_attr.attr,
	NULL,
};
#endif /* CONFIG_PM_TRACE */

static struct attribute_group attr_group = {
	.attrs = g,
};


static int __init pm_init(void)
{
	int error = subsystem_register(&power_subsys);
	if (!error)
		error = sysfs_create_group(&power_subsys.kset.kobj,&attr_group);
	return error;
}

core_initcall(pm_init);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* kernel/power/main.c - PM subsystem core functionality.
	3	*
	4	* Copyright (c) 2003 Patrick Mochel
	5	* Copyright (c) 2003 Open Source Development Lab
	6	*
	7	* This file is released under the GPLv2
	8	*
	9	*/
	10
4cf30348	11	#include <linux/module.h>
1da177e4 LT	12	#include <linux/suspend.h>
	13	#include <linux/kobject.h>
	14	#include <linux/string.h>
	15	#include <linux/delay.h>
	16	#include <linux/errno.h>
	17	#include <linux/init.h>
	18	#include <linux/pm.h>
6cc07191	19	#include <linux/console.h>
e3920fb4	20	#include <linux/cpu.h>
c5c6ba4e	21	#include <linux/resume-trace.h>
7dfb7103	22	#include <linux/freezer.h>
96177299	23	#include <linux/vmstat.h>
1da177e4 LT	24
	25	#include "power.h"
	26
5ae947ec DSL	27	/This is just an arbitrary number /
	28	#define FREE_PAGE_NUMBER (100)
	29
a6d70980	30	DEFINE_MUTEX(pm_mutex);
1da177e4	31
123d3c13	32	struct pm_ops *pm_ops;
fe0c935a	33	suspend_disk_method_t pm_disk_mode = PM_DISK_SHUTDOWN;
1da177e4 LT	34
	35	/**
	36	* pm_set_ops - Set the global power method table.
	37	* @ops: Pointer to ops structure.
	38	*/
	39
	40	void pm_set_ops(struct pm_ops * ops)
	41	{
a6d70980	42	mutex_lock(&pm_mutex);
1da177e4	43	pm_ops = ops;
fe0c935a JB	44	if (ops && ops->pm_disk_mode != PM_DISK_INVALID) {
	45	pm_disk_mode = ops->pm_disk_mode;
	46	} else
	47	pm_disk_mode = PM_DISK_SHUTDOWN;
a6d70980	48	mutex_unlock(&pm_mutex);
1da177e4 LT	49	}
1da177e4 LT	50
e3c7db62 RW	51	static inline void pm_finish(suspend_state_t state)
	52	{
	53	if (pm_ops->finish)
	54	pm_ops->finish(state);
	55	}
1da177e4 LT	56
	57	/**
	58	* suspend_prepare - Do prep work before entering low-power state.
	59	* @state: State we're entering.
	60	*
	61	* This is common code that is called for each state that we're
	62	* entering. Allocate a console, stop all processes, then make sure
	63	* the platform can enter the requested state.
	64	*/
	65
	66	static int suspend_prepare(suspend_state_t state)
	67	{
e3920fb4	68	int error;
5ae947ec	69	unsigned int free_pages;
1da177e4 LT	70
	71	if (!pm_ops \|\| !pm_ops->enter)
	72	return -EPERM;
	73
	74	pm_prepare_console();
	75
	76	if (freeze_processes()) {
	77	error = -EAGAIN;
	78	goto Thaw;
	79	}
	80
96177299 CL	81	if ((free_pages = global_page_state(NR_FREE_PAGES))
96177299 CL	82	< FREE_PAGE_NUMBER) {
5ae947ec DSL	83	pr_debug("PM: free some memory\n");
	84	shrink_all_memory(FREE_PAGE_NUMBER - free_pages);
	85	if (nr_free_pages() < FREE_PAGE_NUMBER) {
	86	error = -ENOMEM;
	87	printk(KERN_ERR "PM: No enough memory\n");
	88	goto Thaw;
	89	}
	90	}
	91
1da177e4 LT	92	if (pm_ops->prepare) {
	93	if ((error = pm_ops->prepare(state)))
	94	goto Thaw;
	95	}
	96
557240b4	97	suspend_console();
e3c7db62 RW	98	error = device_suspend(PMSG_SUSPEND);
e3c7db62 RW	99	if (error) {
1da177e4	100	printk(KERN_ERR "Some devices failed to suspend\n");
e3c7db62	101	goto Resume_devices;
1da177e4	102	}
e3c7db62 RW	103	error = disable_nonboot_cpus();
	104	if (!error)
	105	return 0;
	106
	107	enable_nonboot_cpus();
	108	Resume_devices:
	109	pm_finish(state);
	110	device_resume();
	111	resume_console();
1da177e4 LT	112	Thaw:
	113	thaw_processes();
	114	pm_restore_console();
	115	return error;
	116	}
	117
a53c46dc JB	118	/* default implementation */
	119	void __attribute__ ((weak)) arch_suspend_disable_irqs(void)
	120	{
	121	local_irq_disable();
	122	}
	123
	124	/* default implementation */
	125	void __attribute__ ((weak)) arch_suspend_enable_irqs(void)
	126	{
	127	local_irq_enable();
	128	}
1da177e4	129
9b238205	130	int suspend_enter(suspend_state_t state)
1da177e4 LT	131	{
1da177e4 LT	132	int error = 0;
1da177e4	133
a53c46dc JB	134	arch_suspend_disable_irqs();
a53c46dc JB	135	BUG_ON(!irqs_disabled());
1da177e4 LT	136
	137	if ((error = device_power_down(PMSG_SUSPEND))) {
	138	printk(KERN_ERR "Some devices failed to power down\n");
	139	goto Done;
	140	}
	141	error = pm_ops->enter(state);
	142	device_power_up();
	143	Done:
a53c46dc JB	144	arch_suspend_enable_irqs();
a53c46dc JB	145	BUG_ON(irqs_disabled());
1da177e4 LT	146	return error;
	147	}
	148
	149
	150	/**
	151	* suspend_finish - Do final work before exiting suspend sequence.
	152	* @state: State we're coming out of.
	153	*
	154	* Call platform code to clean up, restart processes, and free the
	155	* console that we've allocated. This is not called for suspend-to-disk.
	156	*/
	157
	158	static void suspend_finish(suspend_state_t state)
	159	{
e3c7db62 RW	160	enable_nonboot_cpus();
e3c7db62 RW	161	pm_finish(state);
1da177e4	162	device_resume();
557240b4	163	resume_console();
1da177e4 LT	164	thaw_processes();
	165	pm_restore_console();
	166	}
	167
	168
	169
	170
3b364b8d	171	static const char * const pm_states[PM_SUSPEND_MAX] = {
1da177e4 LT	172	[PM_SUSPEND_STANDBY] = "standby",
1da177e4 LT	173	[PM_SUSPEND_MEM] = "mem",
57c4ce3c	174	#ifdef CONFIG_SOFTWARE_SUSPEND
1da177e4	175	[PM_SUSPEND_DISK] = "disk",
57c4ce3c	176	#endif
1da177e4 LT	177	};
1da177e4 LT	178
123d3c13 PM	179	static inline int valid_state(suspend_state_t state)
	180	{
	181	/* Suspend-to-disk does not really need low-level support.
	182	* It can work with reboot if needed. */
	183	if (state == PM_SUSPEND_DISK)
	184	return 1;
	185
9c372d06 JB	186	/* all other states need lowlevel support and need to be
	187	* valid to the lowlevel implementation, no valid callback
	188	* implies that all are valid. */
	189	if (!pm_ops \|\| (pm_ops->valid && !pm_ops->valid(state)))
123d3c13 PM	190	return 0;
	191	return 1;
	192	}
	193
1da177e4 LT	194
	195	/**
	196	* enter_state - Do common work of entering low-power state.
	197	* @state: pm_state structure for state we're entering.
	198	*
	199	* Make sure we're the only ones trying to enter a sleep state. Fail
	200	* if someone has beat us to it, since we don't want anything weird to
	201	* happen when we wake up.
	202	* Then, do the setup for suspend, enter the state, and cleaup (after
	203	* we've woken up).
	204	*/
	205
	206	static int enter_state(suspend_state_t state)
	207	{
	208	int error;
	209
123d3c13	210	if (!valid_state(state))
eb9289eb	211	return -ENODEV;
a6d70980	212	if (!mutex_trylock(&pm_mutex))
1da177e4 LT	213	return -EBUSY;
	214
	215	if (state == PM_SUSPEND_DISK) {
	216	error = pm_suspend_disk();
	217	goto Unlock;
	218	}
	219
82428b62	220	pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
1da177e4 LT	221	if ((error = suspend_prepare(state)))
	222	goto Unlock;
	223
82428b62	224	pr_debug("PM: Entering %s sleep\n", pm_states[state]);
1da177e4 LT	225	error = suspend_enter(state);
1da177e4 LT	226
82428b62	227	pr_debug("PM: Finishing wakeup.\n");
1da177e4 LT	228	suspend_finish(state);
1da177e4 LT	229	Unlock:
a6d70980	230	mutex_unlock(&pm_mutex);
1da177e4 LT	231	return error;
	232	}
	233
	234	/*
	235	* This is main interface to the outside world. It needs to be
	236	* called from process context.
	237	*/
	238	int software_suspend(void)
	239	{
	240	return enter_state(PM_SUSPEND_DISK);
	241	}
	242
	243
	244	/**
	245	* pm_suspend - Externally visible function for suspending system.
	246	* @state: Enumarted value of state to enter.
	247	*
	248	* Determine whether or not value is within range, get state
	249	* structure, and enter (above).
	250	*/
	251
	252	int pm_suspend(suspend_state_t state)
	253	{
e2a5b420	254	if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX)
1da177e4 LT	255	return enter_state(state);
	256	return -EINVAL;
	257	}
	258
4cf30348	259	EXPORT_SYMBOL(pm_suspend);
1da177e4 LT	260
	261	decl_subsys(power,NULL,NULL);
	262
	263
	264	/**
	265	* state - control system power state.
	266	*
	267	* show() returns what states are supported, which is hard-coded to
	268	* 'standby' (Power-On Suspend), 'mem' (Suspend-to-RAM), and
	269	* 'disk' (Suspend-to-Disk).
	270	*
	271	* store() accepts one of those strings, translates it into the
	272	* proper enumerated value, and initiates a suspend transition.
	273	*/
	274
	275	static ssize_t state_show(struct subsystem * subsys, char * buf)
	276	{
	277	int i;
	278	char * s = buf;
	279
	280	for (i = 0; i < PM_SUSPEND_MAX; i++) {
123d3c13 PM	281	if (pm_states[i] && valid_state(i))
123d3c13 PM	282	s += sprintf(s,"%s ", pm_states[i]);
1da177e4 LT	283	}
	284	s += sprintf(s,"\n");
	285	return (s - buf);
	286	}
	287
	288	static ssize_t state_store(struct subsystem * subsys, const char * buf, size_t n)
	289	{
	290	suspend_state_t state = PM_SUSPEND_STANDBY;
3b364b8d	291	const char * const *s;
1da177e4 LT	292	char *p;
	293	int error;
	294	int len;
	295
	296	p = memchr(buf, '\n', n);
	297	len = p ? p - buf : n;
	298
	299	for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++) {
	300	if (s && !strncmp(buf, s, len))
	301	break;
	302	}
47bb7899	303	if (state < PM_SUSPEND_MAX && *s)
1da177e4 LT	304	error = enter_state(state);
	305	else
	306	error = -EINVAL;
	307	return error ? error : n;
	308	}
	309
	310	power_attr(state);
	311
c5c6ba4e RW	312	#ifdef CONFIG_PM_TRACE
	313	int pm_trace_enabled;
	314
	315	static ssize_t pm_trace_show(struct subsystem * subsys, char * buf)
	316	{
	317	return sprintf(buf, "%d\n", pm_trace_enabled);
	318	}
	319
	320	static ssize_t
	321	pm_trace_store(struct subsystem * subsys, const char * buf, size_t n)
	322	{
	323	int val;
	324
	325	if (sscanf(buf, "%d", &val) == 1) {
	326	pm_trace_enabled = !!val;
	327	return n;
	328	}
	329	return -EINVAL;
	330	}
	331
	332	power_attr(pm_trace);
	333
	334	static struct attribute * g[] = {
	335	&state_attr.attr,
	336	&pm_trace_attr.attr,
	337	NULL,
	338	};
	339	#else
1da177e4 LT	340	static struct attribute * g[] = {
	341	&state_attr.attr,
	342	NULL,
	343	};
c5c6ba4e	344	#endif /* CONFIG_PM_TRACE */
1da177e4 LT	345
	346	static struct attribute_group attr_group = {
	347	.attrs = g,
	348	};
	349
	350
	351	static int __init pm_init(void)
	352	{
	353	int error = subsystem_register(&power_subsys);
	354	if (!error)
	355	error = sysfs_create_group(&power_subsys.kset.kobj,&attr_group);
	356	return error;
	357	}
	358
	359	core_initcall(pm_init);