[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/kobject.h>
#include <linux/string.h>
#include <linux/resume-trace.h>
#include <linux/workqueue.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>

#include "power.h"

DEFINE_MUTEX(pm_mutex);

#ifdef CONFIG_PM_SLEEP

/* Routines for PM-transition notifications */

static BLOCKING_NOTIFIER_HEAD(pm_chain_head);

int register_pm_notifier(struct notifier_block *nb)
{
	return blocking_notifier_chain_register(&pm_chain_head, nb);
}
EXPORT_SYMBOL_GPL(register_pm_notifier);

int unregister_pm_notifier(struct notifier_block *nb)
{
	return blocking_notifier_chain_unregister(&pm_chain_head, nb);
}
EXPORT_SYMBOL_GPL(unregister_pm_notifier);

int pm_notifier_call_chain(unsigned long val)
{
	int ret = blocking_notifier_call_chain(&pm_chain_head, val, NULL);

	return notifier_to_errno(ret);
}

/* If set, devices may be suspended and resumed asynchronously. */
int pm_async_enabled = 1;

static ssize_t pm_async_show(struct kobject *kobj, struct kobj_attribute *attr,
			     char *buf)
{
	return sprintf(buf, "%d\n", pm_async_enabled);
}

static ssize_t pm_async_store(struct kobject *kobj, struct kobj_attribute *attr,
			      const char *buf, size_t n)
{
	unsigned long val;

	if (strict_strtoul(buf, 10, &val))
		return -EINVAL;

	if (val > 1)
		return -EINVAL;

	pm_async_enabled = val;
	return n;
}

power_attr(pm_async);

#ifdef CONFIG_PM_DEBUG
int pm_test_level = TEST_NONE;

static const char * const pm_tests[__TEST_AFTER_LAST] = {
	[TEST_NONE] = "none",
	[TEST_CORE] = "core",
	[TEST_CPUS] = "processors",
	[TEST_PLATFORM] = "platform",
	[TEST_DEVICES] = "devices",
	[TEST_FREEZER] = "freezer",
};

static ssize_t pm_test_show(struct kobject *kobj, struct kobj_attribute *attr,
				char *buf)
{
	char *s = buf;
	int level;

	for (level = TEST_FIRST; level <= TEST_MAX; level++)
		if (pm_tests[level]) {
			if (level == pm_test_level)
				s += sprintf(s, "[%s] ", pm_tests[level]);
			else
				s += sprintf(s, "%s ", pm_tests[level]);
		}

	if (s != buf)
		/* convert the last space to a newline */
		*(s-1) = '\n';

	return (s - buf);
}

static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
				const char *buf, size_t n)
{
	const char * const *s;
	int level;
	char *p;
	int len;
	int error = -EINVAL;

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

	mutex_lock(&pm_mutex);

	level = TEST_FIRST;
	for (s = &pm_tests[level]; level <= TEST_MAX; s++, level++)
		if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) {
			pm_test_level = level;
			error = 0;
			break;
		}

	mutex_unlock(&pm_mutex);

	return error ? error : n;
}

power_attr(pm_test);
#endif /* CONFIG_PM_DEBUG */

#endif /* CONFIG_PM_SLEEP */

#ifdef CONFIG_DEBUG_FS
static char *suspend_step_name(enum suspend_stat_step step)
{
	switch (step) {
	case SUSPEND_FREEZE:
		return "freeze";
	case SUSPEND_PREPARE:
		return "prepare";
	case SUSPEND_SUSPEND:
		return "suspend";
	case SUSPEND_SUSPEND_NOIRQ:
		return "suspend_noirq";
	case SUSPEND_RESUME_NOIRQ:
		return "resume_noirq";
	case SUSPEND_RESUME:
		return "resume";
	default:
		return "";
	}
}

static int suspend_stats_show(struct seq_file *s, void *unused)
{
	int i, index, last_dev, last_errno, last_step;

	last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
	last_dev %= REC_FAILED_NUM;
	last_errno = suspend_stats.last_failed_errno + REC_FAILED_NUM - 1;
	last_errno %= REC_FAILED_NUM;
	last_step = suspend_stats.last_failed_step + REC_FAILED_NUM - 1;
	last_step %= REC_FAILED_NUM;
	seq_printf(s, "%s: %d\n%s: %d\n%s: %d\n%s: %d\n"
			"%s: %d\n%s: %d\n%s: %d\n%s: %d\n",
			"success", suspend_stats.success,
			"fail", suspend_stats.fail,
			"failed_freeze", suspend_stats.failed_freeze,
			"failed_prepare", suspend_stats.failed_prepare,
			"failed_suspend", suspend_stats.failed_suspend,
			"failed_suspend_noirq",
				suspend_stats.failed_suspend_noirq,
			"failed_resume", suspend_stats.failed_resume,
			"failed_resume_noirq",
				suspend_stats.failed_resume_noirq);
	seq_printf(s,	"failures:\n  last_failed_dev:\t%-s\n",
			suspend_stats.failed_devs[last_dev]);
	for (i = 1; i < REC_FAILED_NUM; i++) {
		index = last_dev + REC_FAILED_NUM - i;
		index %= REC_FAILED_NUM;
		seq_printf(s, "\t\t\t%-s\n",
			suspend_stats.failed_devs[index]);
	}
	seq_printf(s,	"  last_failed_errno:\t%-d\n",
			suspend_stats.errno[last_errno]);
	for (i = 1; i < REC_FAILED_NUM; i++) {
		index = last_errno + REC_FAILED_NUM - i;
		index %= REC_FAILED_NUM;
		seq_printf(s, "\t\t\t%-d\n",
			suspend_stats.errno[index]);
	}
	seq_printf(s,	"  last_failed_step:\t%-s\n",
			suspend_step_name(
				suspend_stats.failed_steps[last_step]));
	for (i = 1; i < REC_FAILED_NUM; i++) {
		index = last_step + REC_FAILED_NUM - i;
		index %= REC_FAILED_NUM;
		seq_printf(s, "\t\t\t%-s\n",
			suspend_step_name(
				suspend_stats.failed_steps[index]));
	}

	return 0;
}

static int suspend_stats_open(struct inode *inode, struct file *file)
{
	return single_open(file, suspend_stats_show, NULL);
}

static const struct file_operations suspend_stats_operations = {
	.open           = suspend_stats_open,
	.read           = seq_read,
	.llseek         = seq_lseek,
	.release        = single_release,
};

static int __init pm_debugfs_init(void)
{
	debugfs_create_file("suspend_stats", S_IFREG | S_IRUGO,
			NULL, NULL, &suspend_stats_operations);
	return 0;
}

late_initcall(pm_debugfs_init);
#endif /* CONFIG_DEBUG_FS */

struct kobject *power_kobj;

/**
 *	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 kobject *kobj, struct kobj_attribute *attr,
			  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 kobject *kobj, struct kobj_attribute *attr,
			   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);
		if (error) {
			suspend_stats.fail++;
			dpm_save_failed_errno(error);
		} else
			suspend_stats.success++;
#endif

 Exit:
	return error ? error : n;
}

power_attr(state);

#ifdef CONFIG_PM_SLEEP
/*
 * The 'wakeup_count' attribute, along with the functions defined in
 * drivers/base/power/wakeup.c, provides a means by which wakeup events can be
 * handled in a non-racy way.
 *
 * If a wakeup event occurs when the system is in a sleep state, it simply is
 * woken up.  In turn, if an event that would wake the system up from a sleep
 * state occurs when it is undergoing a transition to that sleep state, the
 * transition should be aborted.  Moreover, if such an event occurs when the
 * system is in the working state, an attempt to start a transition to the
 * given sleep state should fail during certain period after the detection of
 * the event.  Using the 'state' attribute alone is not sufficient to satisfy
 * these requirements, because a wakeup event may occur exactly when 'state'
 * is being written to and may be delivered to user space right before it is
 * frozen, so the event will remain only partially processed until the system is
 * woken up by another event.  In particular, it won't cause the transition to
 * a sleep state to be aborted.
 *
 * This difficulty may be overcome if user space uses 'wakeup_count' before
 * writing to 'state'.  It first should read from 'wakeup_count' and store
 * the read value.  Then, after carrying out its own preparations for the system
 * transition to a sleep state, it should write the stored value to
 * 'wakeup_count'.  If that fails, at least one wakeup event has occurred since
 * 'wakeup_count' was read and 'state' should not be written to.  Otherwise, it
 * is allowed to write to 'state', but the transition will be aborted if there
 * are any wakeup events detected after 'wakeup_count' was written to.
 */

static ssize_t wakeup_count_show(struct kobject *kobj,
				struct kobj_attribute *attr,
				char *buf)
{
	unsigned int val;

	return pm_get_wakeup_count(&val) ? sprintf(buf, "%u\n", val) : -EINTR;
}

static ssize_t wakeup_count_store(struct kobject *kobj,
				struct kobj_attribute *attr,
				const char *buf, size_t n)
{
	unsigned int val;

	if (sscanf(buf, "%u", &val) == 1) {
		if (pm_save_wakeup_count(val))
			return n;
	}
	return -EINVAL;
}

power_attr(wakeup_count);
#endif /* CONFIG_PM_SLEEP */

#ifdef CONFIG_PM_TRACE
int pm_trace_enabled;

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

static ssize_t
pm_trace_store(struct kobject *kobj, struct kobj_attribute *attr,
	       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 ssize_t pm_trace_dev_match_show(struct kobject *kobj,
				       struct kobj_attribute *attr,
				       char *buf)
{
	return show_trace_dev_match(buf, PAGE_SIZE);
}

static ssize_t
pm_trace_dev_match_store(struct kobject *kobj, struct kobj_attribute *attr,
			 const char *buf, size_t n)
{
	return -EINVAL;
}

power_attr(pm_trace_dev_match);

#endif /* CONFIG_PM_TRACE */

static struct attribute * g[] = {
	&state_attr.attr,
#ifdef CONFIG_PM_TRACE
	&pm_trace_attr.attr,
	&pm_trace_dev_match_attr.attr,
#endif
#ifdef CONFIG_PM_SLEEP
	&pm_async_attr.attr,
	&wakeup_count_attr.attr,
#ifdef CONFIG_PM_DEBUG
	&pm_test_attr.attr,
#endif
#endif
	NULL,
};

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

#ifdef CONFIG_PM_RUNTIME
struct workqueue_struct *pm_wq;
EXPORT_SYMBOL_GPL(pm_wq);

static int __init pm_start_workqueue(void)
{
	pm_wq = alloc_workqueue("pm", WQ_FREEZABLE, 0);

	return pm_wq ? 0 : -ENOMEM;
}
#else
static inline int pm_start_workqueue(void) { return 0; }
#endif

static int __init pm_init(void)
{
	int error = pm_start_workqueue();
	if (error)
		return error;
	hibernate_image_size_init();
	hibernate_reserved_size_init();
	power_kobj = kobject_create_and_add("power", NULL);
	if (!power_kobj)
		return -ENOMEM;
	return sysfs_create_group(power_kobj, &attr_group);
}

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
1da177e4 LT	11	#include <linux/kobject.h>
1da177e4 LT	12	#include <linux/string.h>
c5c6ba4e	13	#include <linux/resume-trace.h>
5e928f77	14	#include <linux/workqueue.h>
2a77c46d SL	15	#include <linux/debugfs.h>
2a77c46d SL	16	#include <linux/seq_file.h>
1da177e4 LT	17
	18	#include "power.h"
	19
a6d70980	20	DEFINE_MUTEX(pm_mutex);
1da177e4	21
cd51e61c RW	22	#ifdef CONFIG_PM_SLEEP
cd51e61c RW	23
82525756 AS	24	/* Routines for PM-transition notifications */
	25
	26	static BLOCKING_NOTIFIER_HEAD(pm_chain_head);
	27
	28	int register_pm_notifier(struct notifier_block *nb)
	29	{
	30	return blocking_notifier_chain_register(&pm_chain_head, nb);
	31	}
	32	EXPORT_SYMBOL_GPL(register_pm_notifier);
	33
	34	int unregister_pm_notifier(struct notifier_block *nb)
	35	{
	36	return blocking_notifier_chain_unregister(&pm_chain_head, nb);
	37	}
	38	EXPORT_SYMBOL_GPL(unregister_pm_notifier);
	39
	40	int pm_notifier_call_chain(unsigned long val)
	41	{
f0c077a8 AM	42	int ret = blocking_notifier_call_chain(&pm_chain_head, val, NULL);
	43
	44	return notifier_to_errno(ret);
82525756 AS	45	}
82525756 AS	46
0e06b4a8 RW	47	/* If set, devices may be suspended and resumed asynchronously. */
	48	int pm_async_enabled = 1;
	49
	50	static ssize_t pm_async_show(struct kobject kobj, struct kobj_attribute attr,
	51	char *buf)
	52	{
	53	return sprintf(buf, "%d\n", pm_async_enabled);
	54	}
	55
	56	static ssize_t pm_async_store(struct kobject kobj, struct kobj_attribute attr,
	57	const char *buf, size_t n)
	58	{
	59	unsigned long val;
	60
	61	if (strict_strtoul(buf, 10, &val))
	62	return -EINVAL;
	63
	64	if (val > 1)
	65	return -EINVAL;
	66
	67	pm_async_enabled = val;
	68	return n;
	69	}
	70
	71	power_attr(pm_async);
	72
0e7d56e3 RW	73	#ifdef CONFIG_PM_DEBUG
	74	int pm_test_level = TEST_NONE;
	75
0e7d56e3 RW	76	static const char * const pm_tests[__TEST_AFTER_LAST] = {
	77	[TEST_NONE] = "none",
	78	[TEST_CORE] = "core",
	79	[TEST_CPUS] = "processors",
	80	[TEST_PLATFORM] = "platform",
	81	[TEST_DEVICES] = "devices",
	82	[TEST_FREEZER] = "freezer",
	83	};
	84
039a75c6 RW	85	static ssize_t pm_test_show(struct kobject kobj, struct kobj_attribute attr,
039a75c6 RW	86	char *buf)
0e7d56e3 RW	87	{
	88	char *s = buf;
	89	int level;
	90
	91	for (level = TEST_FIRST; level <= TEST_MAX; level++)
	92	if (pm_tests[level]) {
	93	if (level == pm_test_level)
	94	s += sprintf(s, "[%s] ", pm_tests[level]);
	95	else
	96	s += sprintf(s, "%s ", pm_tests[level]);
	97	}
	98
	99	if (s != buf)
	100	/* convert the last space to a newline */
	101	*(s-1) = '\n';
	102
	103	return (s - buf);
	104	}
	105
039a75c6 RW	106	static ssize_t pm_test_store(struct kobject kobj, struct kobj_attribute attr,
039a75c6 RW	107	const char *buf, size_t n)
0e7d56e3 RW	108	{
	109	const char * const *s;
	110	int level;
	111	char *p;
	112	int len;
	113	int error = -EINVAL;
	114
	115	p = memchr(buf, '\n', n);
	116	len = p ? p - buf : n;
	117
	118	mutex_lock(&pm_mutex);
	119
	120	level = TEST_FIRST;
	121	for (s = &pm_tests[level]; level <= TEST_MAX; s++, level++)
	122	if (s && len == strlen(s) && !strncmp(buf, *s, len)) {
	123	pm_test_level = level;
	124	error = 0;
	125	break;
	126	}
	127
	128	mutex_unlock(&pm_mutex);
	129
	130	return error ? error : n;
	131	}
	132
	133	power_attr(pm_test);
091d71e0	134	#endif /* CONFIG_PM_DEBUG */
0e7d56e3	135
7671b8ae	136	#endif /* CONFIG_PM_SLEEP */
039a75c6	137
2a77c46d SL	138	#ifdef CONFIG_DEBUG_FS
	139	static char *suspend_step_name(enum suspend_stat_step step)
	140	{
	141	switch (step) {
	142	case SUSPEND_FREEZE:
	143	return "freeze";
	144	case SUSPEND_PREPARE:
	145	return "prepare";
	146	case SUSPEND_SUSPEND:
	147	return "suspend";
	148	case SUSPEND_SUSPEND_NOIRQ:
	149	return "suspend_noirq";
	150	case SUSPEND_RESUME_NOIRQ:
	151	return "resume_noirq";
	152	case SUSPEND_RESUME:
	153	return "resume";
	154	default:
	155	return "";
	156	}
	157	}
	158
	159	static int suspend_stats_show(struct seq_file s, void unused)
	160	{
	161	int i, index, last_dev, last_errno, last_step;
	162
	163	last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
	164	last_dev %= REC_FAILED_NUM;
	165	last_errno = suspend_stats.last_failed_errno + REC_FAILED_NUM - 1;
	166	last_errno %= REC_FAILED_NUM;
	167	last_step = suspend_stats.last_failed_step + REC_FAILED_NUM - 1;
	168	last_step %= REC_FAILED_NUM;
	169	seq_printf(s, "%s: %d\n%s: %d\n%s: %d\n%s: %d\n"
	170	"%s: %d\n%s: %d\n%s: %d\n%s: %d\n",
	171	"success", suspend_stats.success,
	172	"fail", suspend_stats.fail,
	173	"failed_freeze", suspend_stats.failed_freeze,
	174	"failed_prepare", suspend_stats.failed_prepare,
	175	"failed_suspend", suspend_stats.failed_suspend,
	176	"failed_suspend_noirq",
	177	suspend_stats.failed_suspend_noirq,
	178	"failed_resume", suspend_stats.failed_resume,
	179	"failed_resume_noirq",
	180	suspend_stats.failed_resume_noirq);
	181	seq_printf(s, "failures:\n last_failed_dev:\t%-s\n",
	182	suspend_stats.failed_devs[last_dev]);
	183	for (i = 1; i < REC_FAILED_NUM; i++) {
	184	index = last_dev + REC_FAILED_NUM - i;
	185	index %= REC_FAILED_NUM;
	186	seq_printf(s, "\t\t\t%-s\n",
	187	suspend_stats.failed_devs[index]);
	188	}
	189	seq_printf(s, " last_failed_errno:\t%-d\n",
	190	suspend_stats.errno[last_errno]);
	191	for (i = 1; i < REC_FAILED_NUM; i++) {
	192	index = last_errno + REC_FAILED_NUM - i;
	193	index %= REC_FAILED_NUM;
	194	seq_printf(s, "\t\t\t%-d\n",
	195	suspend_stats.errno[index]);
	196	}
	197	seq_printf(s, " last_failed_step:\t%-s\n",
	198	suspend_step_name(
	199	suspend_stats.failed_steps[last_step]));
	200	for (i = 1; i < REC_FAILED_NUM; i++) {
	201	index = last_step + REC_FAILED_NUM - i;
202	index %= REC_FAILED_NUM;
203	seq_printf(s, "\t\t\t%-s\n",
204	suspend_step_name(
205	suspend_stats.failed_steps[index]));
206	}
207
208	return 0;
209	}
210
211	static int suspend_stats_open(struct inode inode, struct file file)
212	{
213	return single_open(file, suspend_stats_show, NULL);
214	}
215
216	static const struct file_operations suspend_stats_operations = {
217	.open = suspend_stats_open,
218	.read = seq_read,
219	.llseek = seq_lseek,
220	.release = single_release,
221	};
222
223	static int __init pm_debugfs_init(void)
224	{
225	debugfs_create_file("suspend_stats", S_IFREG \| S_IRUGO,
226	NULL, NULL, &suspend_stats_operations);
227	return 0;
228	}
229
230	late_initcall(pm_debugfs_init);
231	#endif /* CONFIG_DEBUG_FS */
232
d76e15fb	233	struct kobject *power_kobj;
1da177e4 LT	234
	235	/**
	236	* state - control system power state.
	237	*
	238	* show() returns what states are supported, which is hard-coded to
	239	* 'standby' (Power-On Suspend), 'mem' (Suspend-to-RAM), and
	240	* 'disk' (Suspend-to-Disk).
	241	*
	242	* store() accepts one of those strings, translates it into the
	243	* proper enumerated value, and initiates a suspend transition.
	244	*/
386f275f KS	245	static ssize_t state_show(struct kobject kobj, struct kobj_attribute attr,
386f275f KS	246	char *buf)
1da177e4	247	{
296699de RW	248	char *s = buf;
296699de RW	249	#ifdef CONFIG_SUSPEND
1da177e4	250	int i;
1da177e4 LT	251
1da177e4 LT	252	for (i = 0; i < PM_SUSPEND_MAX; i++) {
123d3c13 PM	253	if (pm_states[i] && valid_state(i))
123d3c13 PM	254	s += sprintf(s,"%s ", pm_states[i]);
1da177e4	255	}
296699de	256	#endif
b0cb1a19	257	#ifdef CONFIG_HIBERNATION
a3d25c27 RW	258	s += sprintf(s, "%s\n", "disk");
	259	#else
	260	if (s != buf)
	261	/* convert the last space to a newline */
	262	*(s-1) = '\n';
	263	#endif
1da177e4 LT	264	return (s - buf);
	265	}
	266
386f275f KS	267	static ssize_t state_store(struct kobject kobj, struct kobj_attribute attr,
386f275f KS	268	const char *buf, size_t n)
1da177e4	269	{
296699de	270	#ifdef CONFIG_SUSPEND
1da177e4	271	suspend_state_t state = PM_SUSPEND_STANDBY;
3b364b8d	272	const char * const *s;
296699de	273	#endif
1da177e4	274	char *p;
1da177e4	275	int len;
296699de	276	int error = -EINVAL;
1da177e4 LT	277
	278	p = memchr(buf, '\n', n);
	279	len = p ? p - buf : n;
	280
a3d25c27	281	/* First, check if we are requested to hibernate */
8d98a690	282	if (len == 4 && !strncmp(buf, "disk", len)) {
a3d25c27	283	error = hibernate();
296699de	284	goto Exit;
a3d25c27 RW	285	}
a3d25c27 RW	286
296699de	287	#ifdef CONFIG_SUSPEND
1da177e4	288	for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++) {
8d98a690	289	if (s && len == strlen(s) && !strncmp(buf, *s, len))
1da177e4 LT	290	break;
1da177e4 LT	291	}
47bb7899	292	if (state < PM_SUSPEND_MAX && *s)
1da177e4	293	error = enter_state(state);
2a77c46d SL	294	if (error) {
	295	suspend_stats.fail++;
	296	dpm_save_failed_errno(error);
	297	} else
	298	suspend_stats.success++;
296699de RW	299	#endif
	300
	301	Exit:
1da177e4 LT	302	return error ? error : n;
	303	}
	304
	305	power_attr(state);
	306
c125e96f RW	307	#ifdef CONFIG_PM_SLEEP
	308	/*
	309	* The 'wakeup_count' attribute, along with the functions defined in
	310	* drivers/base/power/wakeup.c, provides a means by which wakeup events can be
	311	* handled in a non-racy way.
	312	*
	313	* If a wakeup event occurs when the system is in a sleep state, it simply is
	314	* woken up. In turn, if an event that would wake the system up from a sleep
	315	* state occurs when it is undergoing a transition to that sleep state, the
	316	* transition should be aborted. Moreover, if such an event occurs when the
	317	* system is in the working state, an attempt to start a transition to the
	318	* given sleep state should fail during certain period after the detection of
	319	* the event. Using the 'state' attribute alone is not sufficient to satisfy
	320	* these requirements, because a wakeup event may occur exactly when 'state'
	321	* is being written to and may be delivered to user space right before it is
	322	* frozen, so the event will remain only partially processed until the system is
	323	* woken up by another event. In particular, it won't cause the transition to
	324	* a sleep state to be aborted.
	325	*
	326	* This difficulty may be overcome if user space uses 'wakeup_count' before
	327	* writing to 'state'. It first should read from 'wakeup_count' and store
	328	* the read value. Then, after carrying out its own preparations for the system
	329	* transition to a sleep state, it should write the stored value to
25985edc	330	* 'wakeup_count'. If that fails, at least one wakeup event has occurred since
c125e96f RW	331	* 'wakeup_count' was read and 'state' should not be written to. Otherwise, it
	332	* is allowed to write to 'state', but the transition will be aborted if there
	333	* are any wakeup events detected after 'wakeup_count' was written to.
	334	*/
	335
	336	static ssize_t wakeup_count_show(struct kobject *kobj,
	337	struct kobj_attribute *attr,
	338	char *buf)
	339	{
074037ec	340	unsigned int val;
c125e96f	341
074037ec	342	return pm_get_wakeup_count(&val) ? sprintf(buf, "%u\n", val) : -EINTR;
c125e96f RW	343	}
	344
	345	static ssize_t wakeup_count_store(struct kobject *kobj,
	346	struct kobj_attribute *attr,
	347	const char *buf, size_t n)
	348	{
074037ec	349	unsigned int val;
c125e96f	350
074037ec	351	if (sscanf(buf, "%u", &val) == 1) {
c125e96f RW	352	if (pm_save_wakeup_count(val))
	353	return n;
	354	}
	355	return -EINVAL;
	356	}
	357
	358	power_attr(wakeup_count);
	359	#endif /* CONFIG_PM_SLEEP */
	360
c5c6ba4e RW	361	#ifdef CONFIG_PM_TRACE
	362	int pm_trace_enabled;
	363
386f275f KS	364	static ssize_t pm_trace_show(struct kobject kobj, struct kobj_attribute attr,
386f275f KS	365	char *buf)
c5c6ba4e RW	366	{
	367	return sprintf(buf, "%d\n", pm_trace_enabled);
	368	}
	369
	370	static ssize_t
386f275f KS	371	pm_trace_store(struct kobject kobj, struct kobj_attribute attr,
386f275f KS	372	const char *buf, size_t n)
c5c6ba4e RW	373	{
	374	int val;
	375
	376	if (sscanf(buf, "%d", &val) == 1) {
	377	pm_trace_enabled = !!val;
	378	return n;
	379	}
	380	return -EINVAL;
	381	}
	382
	383	power_attr(pm_trace);
d33ac60b JH	384
	385	static ssize_t pm_trace_dev_match_show(struct kobject *kobj,
	386	struct kobj_attribute *attr,
	387	char *buf)
	388	{
	389	return show_trace_dev_match(buf, PAGE_SIZE);
	390	}
	391
	392	static ssize_t
	393	pm_trace_dev_match_store(struct kobject kobj, struct kobj_attribute attr,
	394	const char *buf, size_t n)
	395	{
	396	return -EINVAL;
	397	}
	398
	399	power_attr(pm_trace_dev_match);
	400
0e7d56e3	401	#endif /* CONFIG_PM_TRACE */
c5c6ba4e RW	402
	403	static struct attribute * g[] = {
	404	&state_attr.attr,
0e7d56e3	405	#ifdef CONFIG_PM_TRACE
c5c6ba4e	406	&pm_trace_attr.attr,
d33ac60b	407	&pm_trace_dev_match_attr.attr,
0e7d56e3	408	#endif
0e06b4a8 RW	409	#ifdef CONFIG_PM_SLEEP
0e06b4a8 RW	410	&pm_async_attr.attr,
c125e96f	411	&wakeup_count_attr.attr,
0e06b4a8	412	#ifdef CONFIG_PM_DEBUG
0e7d56e3	413	&pm_test_attr.attr,
0e06b4a8	414	#endif
0e7d56e3	415	#endif
c5c6ba4e RW	416	NULL,
c5c6ba4e RW	417	};
1da177e4 LT	418
	419	static struct attribute_group attr_group = {
	420	.attrs = g,
	421	};
	422
5e928f77 RW	423	#ifdef CONFIG_PM_RUNTIME
5e928f77 RW	424	struct workqueue_struct *pm_wq;
7b199ca2	425	EXPORT_SYMBOL_GPL(pm_wq);
5e928f77 RW	426
	427	static int __init pm_start_workqueue(void)
	428	{
58a69cb4	429	pm_wq = alloc_workqueue("pm", WQ_FREEZABLE, 0);
5e928f77 RW	430
	431	return pm_wq ? 0 : -ENOMEM;
	432	}
	433	#else
	434	static inline int pm_start_workqueue(void) { return 0; }
	435	#endif
	436
1da177e4 LT	437	static int __init pm_init(void)
1da177e4 LT	438	{
5e928f77 RW	439	int error = pm_start_workqueue();
	440	if (error)
	441	return error;
ac5c24ec	442	hibernate_image_size_init();
ddeb6487	443	hibernate_reserved_size_init();
d76e15fb GKH	444	power_kobj = kobject_create_and_add("power", NULL);
d76e15fb GKH	445	if (!power_kobj)
039a5dcd	446	return -ENOMEM;
d76e15fb	447	return sysfs_create_group(power_kobj, &attr_group);
1da177e4 LT	448	}
	449
	450	core_initcall(pm_init);