[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/console.h>
#include <linux/cpu.h>
#include <linux/resume-trace.h>
#include <linux/freezer.h>
#include <linux/vmstat.h>
#include <linux/syscalls.h>

#include "power.h"

BLOCKING_NOTIFIER_HEAD(pm_chain_head);

DEFINE_MUTEX(pm_mutex);

#ifdef CONFIG_SUSPEND

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

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);
}

/**
 * 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;
}

/**
 *	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;
	unsigned int free_pages;

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

	error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
	if (error)
		goto Finish;

	pm_prepare_console();

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

	free_pages = global_page_state(NR_FREE_PAGES);
	if (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");
		}
	}
	if (!error)
		return 0;

 Thaw:
	thaw_processes();
	pm_restore_console();
 Finish:
	pm_notifier_call_chain(PM_POST_SUSPEND);
	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 = 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 = suspend_ops->enter(state);
	device_power_up();
 Done:
	arch_suspend_enable_irqs();
	BUG_ON(irqs_disabled());
	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;

	if (suspend_ops->set_target) {
		error = suspend_ops->set_target(state);
		if (error)
			return error;
	}
	suspend_console();
	error = device_suspend(PMSG_SUSPEND);
	if (error) {
		printk(KERN_ERR "Some devices failed to suspend\n");
		goto Resume_console;
	}
	if (suspend_ops->prepare) {
		error = suspend_ops->prepare();
		if (error)
			goto Resume_devices;
	}
	error = disable_nonboot_cpus();
	if (!error)
		suspend_enter(state);

	enable_nonboot_cpus();
	if (suspend_ops->finish)
		suspend_ops->finish();
 Resume_devices:
	device_resume();
 Resume_console:
	resume_console();
	return error;
}

/**
 *	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)
{
	thaw_processes();
	pm_restore_console();
	pm_notifier_call_chain(PM_POST_SUSPEND);
}


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

static inline int 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. */
	if (!suspend_ops || !suspend_ops->valid || !suspend_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;

	printk("Syncing filesystems ... ");
	sys_sync();
	printk("done.\n");

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

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

	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);

#endif /* CONFIG_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 kset *kset, char *buf)
{
	char *s = buf;
#ifdef CONFIG_SUSPEND
	int i;

	for (i = 0; i < PM_SUSPEND_MAX; i++) {
		if (pm_states[i] && valid_state(i))
			s += sprintf(s,"%s ", pm_states[i]);
	}
#endif
#ifdef CONFIG_HIBERNATION
	s += sprintf(s, "%s\n", "disk");
#else
	if (s != buf)
		/* convert the last space to a newline */
		*(s-1) = '\n';
#endif
	return (s - buf);
}

static ssize_t state_store(struct kset *kset, const char *buf, size_t n)
{
#ifdef CONFIG_SUSPEND
	suspend_state_t state = PM_SUSPEND_STANDBY;
	const char * const *s;
#endif
	char *p;
	int len;
	int error = -EINVAL;

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

	/* First, check if we are requested to hibernate */
	if (len == 4 && !strncmp(buf, "disk", len)) {
		error = hibernate();
  goto Exit;
	}

#ifdef CONFIG_SUSPEND
	for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++) {
		if (*s && len == strlen(*s) && !strncmp(buf, *s, len))
			break;
	}
	if (state < PM_SUSPEND_MAX && *s)
		error = enter_state(state);
#endif

 Exit:
	return error ? error : n;
}

power_attr(state);

#ifdef CONFIG_PM_TRACE
int pm_trace_enabled;

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

static ssize_t
pm_trace_store(struct kset *kset, 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.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>
6cc07191	18	#include <linux/console.h>
e3920fb4	19	#include <linux/cpu.h>
c5c6ba4e	20	#include <linux/resume-trace.h>
7dfb7103	21	#include <linux/freezer.h>
96177299	22	#include <linux/vmstat.h>
232b1432	23	#include <linux/syscalls.h>
1da177e4 LT	24
	25	#include "power.h"
	26
b10d9117 RW	27	BLOCKING_NOTIFIER_HEAD(pm_chain_head);
b10d9117 RW	28
a6d70980	29	DEFINE_MUTEX(pm_mutex);
1da177e4	30
296699de RW	31	#ifdef CONFIG_SUSPEND
	32
	33	/* This is just an arbitrary number */
	34	#define FREE_PAGE_NUMBER (100)
	35
f242d919	36	static struct platform_suspend_ops *suspend_ops;
1da177e4 LT	37
1da177e4 LT	38	/**
26398a70	39	* suspend_set_ops - Set the global suspend method table.
1da177e4 LT	40	* @ops: Pointer to ops structure.
	41	*/
	42
26398a70	43	void suspend_set_ops(struct platform_suspend_ops *ops)
1da177e4	44	{
a6d70980	45	mutex_lock(&pm_mutex);
26398a70	46	suspend_ops = ops;
a6d70980	47	mutex_unlock(&pm_mutex);
1da177e4 LT	48	}
1da177e4 LT	49
e8c9c502	50	/**
26398a70	51	* suspend_valid_only_mem - generic memory-only valid callback
e8c9c502	52	*
26398a70	53	* Platform drivers that implement mem suspend only and only need
e8c9c502 JB	54	* to check for that in their .valid callback can use this instead
	55	* of rolling their own .valid callback.
	56	*/
26398a70	57	int suspend_valid_only_mem(suspend_state_t state)
e8c9c502 JB	58	{
	59	return state == PM_SUSPEND_MEM;
	60	}
	61
1da177e4 LT	62	/**
1da177e4 LT	63	* suspend_prepare - Do prep work before entering low-power state.
1da177e4	64	*
6c961dfb RW	65	* This is common code that is called for each state that we're entering.
6c961dfb RW	66	* Run suspend notifiers, allocate a console and stop all processes.
1da177e4	67	*/
6c961dfb	68	static int suspend_prepare(void)
1da177e4	69	{
e3920fb4	70	int error;
5ae947ec	71	unsigned int free_pages;
1da177e4	72
26398a70	73	if (!suspend_ops \|\| !suspend_ops->enter)
1da177e4 LT	74	return -EPERM;
1da177e4 LT	75
b10d9117 RW	76	error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
	77	if (error)
	78	goto Finish;
	79
1da177e4 LT	80	pm_prepare_console();
	81
	82	if (freeze_processes()) {
	83	error = -EAGAIN;
	84	goto Thaw;
	85	}
	86
6c961dfb RW	87	free_pages = global_page_state(NR_FREE_PAGES);
6c961dfb RW	88	if (free_pages < FREE_PAGE_NUMBER) {
5ae947ec DSL	89	pr_debug("PM: free some memory\n");
	90	shrink_all_memory(FREE_PAGE_NUMBER - free_pages);
	91	if (nr_free_pages() < FREE_PAGE_NUMBER) {
	92	error = -ENOMEM;
	93	printk(KERN_ERR "PM: No enough memory\n");
5ae947ec DSL	94	}
5ae947ec DSL	95	}
e3c7db62 RW	96	if (!error)
	97	return 0;
	98
1da177e4 LT	99	Thaw:
	100	thaw_processes();
	101	pm_restore_console();
b10d9117 RW	102	Finish:
b10d9117 RW	103	pm_notifier_call_chain(PM_POST_SUSPEND);
1da177e4 LT	104	return error;
	105	}
	106
a53c46dc JB	107	/* default implementation */
	108	void __attribute__ ((weak)) arch_suspend_disable_irqs(void)
	109	{
	110	local_irq_disable();
	111	}
	112
	113	/* default implementation */
	114	void __attribute__ ((weak)) arch_suspend_enable_irqs(void)
	115	{
	116	local_irq_enable();
	117	}
1da177e4	118
6c961dfb RW	119	/**
	120	* suspend_enter - enter the desired system sleep state.
	121	* @state: state to enter
	122	*
	123	* This function should be called after devices have been suspended.
	124	*/
a065c86e	125	static int suspend_enter(suspend_state_t state)
1da177e4 LT	126	{
1da177e4 LT	127	int error = 0;
1da177e4	128
a53c46dc JB	129	arch_suspend_disable_irqs();
a53c46dc JB	130	BUG_ON(!irqs_disabled());
1da177e4 LT	131
	132	if ((error = device_power_down(PMSG_SUSPEND))) {
	133	printk(KERN_ERR "Some devices failed to power down\n");
	134	goto Done;
	135	}
26398a70	136	error = suspend_ops->enter(state);
1da177e4 LT	137	device_power_up();
1da177e4 LT	138	Done:
a53c46dc JB	139	arch_suspend_enable_irqs();
a53c46dc JB	140	BUG_ON(irqs_disabled());
1da177e4 LT	141	return error;
	142	}
	143
6c961dfb RW	144	/**
	145	* suspend_devices_and_enter - suspend devices and enter the desired system sleep
	146	* state.
	147	* @state: state to enter
	148	*/
	149	int suspend_devices_and_enter(suspend_state_t state)
	150	{
	151	int error;
	152
26398a70	153	if (!suspend_ops)
6c961dfb RW	154	return -ENOSYS;
6c961dfb RW	155
26398a70 RW	156	if (suspend_ops->set_target) {
26398a70 RW	157	error = suspend_ops->set_target(state);
6c961dfb RW	158	if (error)
	159	return error;
	160	}
	161	suspend_console();
	162	error = device_suspend(PMSG_SUSPEND);
	163	if (error) {
	164	printk(KERN_ERR "Some devices failed to suspend\n");
	165	goto Resume_console;
	166	}
26398a70	167	if (suspend_ops->prepare) {
e6c5eb95	168	error = suspend_ops->prepare();
6c961dfb RW	169	if (error)
	170	goto Resume_devices;
	171	}
	172	error = disable_nonboot_cpus();
	173	if (!error)
	174	suspend_enter(state);
	175
	176	enable_nonboot_cpus();
e6c5eb95 RW	177	if (suspend_ops->finish)
e6c5eb95 RW	178	suspend_ops->finish();
6c961dfb RW	179	Resume_devices:
	180	device_resume();
	181	Resume_console:
	182	resume_console();
	183	return error;
	184	}
1da177e4 LT	185
	186	/**
	187	* suspend_finish - Do final work before exiting suspend sequence.
1da177e4 LT	188	*
	189	* Call platform code to clean up, restart processes, and free the
	190	* console that we've allocated. This is not called for suspend-to-disk.
	191	*/
6c961dfb	192	static void suspend_finish(void)
1da177e4	193	{
1da177e4 LT	194	thaw_processes();
1da177e4 LT	195	pm_restore_console();
b10d9117	196	pm_notifier_call_chain(PM_POST_SUSPEND);
1da177e4 LT	197	}
	198
	199
	200
	201
3b364b8d	202	static const char * const pm_states[PM_SUSPEND_MAX] = {
1da177e4 LT	203	[PM_SUSPEND_STANDBY] = "standby",
1da177e4 LT	204	[PM_SUSPEND_MEM] = "mem",
1da177e4 LT	205	};
1da177e4 LT	206
123d3c13 PM	207	static inline int valid_state(suspend_state_t state)
123d3c13 PM	208	{
a3d25c27 RW	209	/* All states need lowlevel support and need to be valid
a3d25c27 RW	210	* to the lowlevel implementation, no valid callback
9684e51c	211	* implies that none are valid. */
26398a70	212	if (!suspend_ops \|\| !suspend_ops->valid \|\| !suspend_ops->valid(state))
123d3c13 PM	213	return 0;
	214	return 1;
	215	}
	216
1da177e4 LT	217
	218	/**
	219	* enter_state - Do common work of entering low-power state.
	220	* @state: pm_state structure for state we're entering.
	221	*
	222	* Make sure we're the only ones trying to enter a sleep state. Fail
	223	* if someone has beat us to it, since we don't want anything weird to
	224	* happen when we wake up.
	225	* Then, do the setup for suspend, enter the state, and cleaup (after
	226	* we've woken up).
	227	*/
1da177e4 LT	228	static int enter_state(suspend_state_t state)
	229	{
	230	int error;
	231
123d3c13	232	if (!valid_state(state))
eb9289eb	233	return -ENODEV;
232b1432	234
a6d70980	235	if (!mutex_trylock(&pm_mutex))
1da177e4 LT	236	return -EBUSY;
1da177e4 LT	237
232b1432 RW	238	printk("Syncing filesystems ... ");
	239	sys_sync();
	240	printk("done.\n");
	241
82428b62	242	pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
6c961dfb	243	if ((error = suspend_prepare()))
1da177e4 LT	244	goto Unlock;
1da177e4 LT	245
82428b62	246	pr_debug("PM: Entering %s sleep\n", pm_states[state]);
6c961dfb	247	error = suspend_devices_and_enter(state);
1da177e4	248
82428b62	249	pr_debug("PM: Finishing wakeup.\n");
6c961dfb	250	suspend_finish();
1da177e4	251	Unlock:
a6d70980	252	mutex_unlock(&pm_mutex);
1da177e4 LT	253	return error;
	254	}
	255
1da177e4 LT	256
	257	/**
	258	* pm_suspend - Externally visible function for suspending system.
a3d25c27	259	* @state: Enumerated value of state to enter.
1da177e4 LT	260	*
	261	* Determine whether or not value is within range, get state
	262	* structure, and enter (above).
	263	*/
	264
	265	int pm_suspend(suspend_state_t state)
	266	{
e2a5b420	267	if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX)
1da177e4 LT	268	return enter_state(state);
	269	return -EINVAL;
	270	}
	271
4cf30348	272	EXPORT_SYMBOL(pm_suspend);
1da177e4	273
296699de RW	274	#endif /* CONFIG_SUSPEND */
296699de RW	275
1da177e4 LT	276	decl_subsys(power,NULL,NULL);
	277
	278
	279	/**
	280	* state - control system power state.
	281	*
	282	* show() returns what states are supported, which is hard-coded to
	283	* 'standby' (Power-On Suspend), 'mem' (Suspend-to-RAM), and
	284	* 'disk' (Suspend-to-Disk).
	285	*
	286	* store() accepts one of those strings, translates it into the
	287	* proper enumerated value, and initiates a suspend transition.
	288	*/
	289
823bccfc	290	static ssize_t state_show(struct kset kset, char buf)
1da177e4	291	{
296699de RW	292	char *s = buf;
296699de RW	293	#ifdef CONFIG_SUSPEND
1da177e4	294	int i;
1da177e4 LT	295
1da177e4 LT	296	for (i = 0; i < PM_SUSPEND_MAX; i++) {
123d3c13 PM	297	if (pm_states[i] && valid_state(i))
123d3c13 PM	298	s += sprintf(s,"%s ", pm_states[i]);
1da177e4	299	}
296699de	300	#endif
b0cb1a19	301	#ifdef CONFIG_HIBERNATION
a3d25c27 RW	302	s += sprintf(s, "%s\n", "disk");
	303	#else
	304	if (s != buf)
	305	/* convert the last space to a newline */
	306	*(s-1) = '\n';
	307	#endif
1da177e4 LT	308	return (s - buf);
	309	}
	310
823bccfc	311	static ssize_t state_store(struct kset kset, const char buf, size_t n)
1da177e4	312	{
296699de	313	#ifdef CONFIG_SUSPEND
1da177e4	314	suspend_state_t state = PM_SUSPEND_STANDBY;
3b364b8d	315	const char * const *s;
296699de	316	#endif
1da177e4	317	char *p;
1da177e4	318	int len;
296699de	319	int error = -EINVAL;
1da177e4 LT	320
	321	p = memchr(buf, '\n', n);
	322	len = p ? p - buf : n;
	323
a3d25c27	324	/* First, check if we are requested to hibernate */
8d98a690	325	if (len == 4 && !strncmp(buf, "disk", len)) {
a3d25c27	326	error = hibernate();
296699de	327	goto Exit;
a3d25c27 RW	328	}
a3d25c27 RW	329
296699de	330	#ifdef CONFIG_SUSPEND
1da177e4	331	for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++) {
8d98a690	332	if (s && len == strlen(s) && !strncmp(buf, *s, len))
1da177e4 LT	333	break;
1da177e4 LT	334	}
47bb7899	335	if (state < PM_SUSPEND_MAX && *s)
1da177e4	336	error = enter_state(state);
296699de RW	337	#endif
	338
	339	Exit:
1da177e4 LT	340	return error ? error : n;
	341	}
	342
	343	power_attr(state);
	344
c5c6ba4e RW	345	#ifdef CONFIG_PM_TRACE
	346	int pm_trace_enabled;
	347
823bccfc	348	static ssize_t pm_trace_show(struct kset kset, char buf)
c5c6ba4e RW	349	{
	350	return sprintf(buf, "%d\n", pm_trace_enabled);
	351	}
	352
	353	static ssize_t
823bccfc	354	pm_trace_store(struct kset kset, const char buf, size_t n)
c5c6ba4e RW	355	{
	356	int val;
	357
	358	if (sscanf(buf, "%d", &val) == 1) {
	359	pm_trace_enabled = !!val;
	360	return n;
	361	}
	362	return -EINVAL;
	363	}
	364
	365	power_attr(pm_trace);
	366
	367	static struct attribute * g[] = {
	368	&state_attr.attr,
	369	&pm_trace_attr.attr,
	370	NULL,
	371	};
	372	#else
1da177e4 LT	373	static struct attribute * g[] = {
	374	&state_attr.attr,
	375	NULL,
	376	};
c5c6ba4e	377	#endif /* CONFIG_PM_TRACE */
1da177e4 LT	378
	379	static struct attribute_group attr_group = {
	380	.attrs = g,
	381	};
	382
	383
	384	static int __init pm_init(void)
	385	{
	386	int error = subsystem_register(&power_subsys);
	387	if (!error)
823bccfc	388	error = sysfs_create_group(&power_subsys.kobj,&attr_group);
1da177e4 LT	389	return error;
	390	}
	391
	392	core_initcall(pm_init);