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v3.1
  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
 
 11#include <linux/kobject.h>
 12#include <linux/string.h>
 13#include <linux/resume-trace.h>
 14#include <linux/workqueue.h>
 
 
 15
 16#include "power.h"
 17
 18DEFINE_MUTEX(pm_mutex);
 19
 20#ifdef CONFIG_PM_SLEEP
 21
 22/* Routines for PM-transition notifications */
 23
 24static BLOCKING_NOTIFIER_HEAD(pm_chain_head);
 25
 26int register_pm_notifier(struct notifier_block *nb)
 27{
 28	return blocking_notifier_chain_register(&pm_chain_head, nb);
 29}
 30EXPORT_SYMBOL_GPL(register_pm_notifier);
 31
 32int unregister_pm_notifier(struct notifier_block *nb)
 33{
 34	return blocking_notifier_chain_unregister(&pm_chain_head, nb);
 35}
 36EXPORT_SYMBOL_GPL(unregister_pm_notifier);
 37
 38int pm_notifier_call_chain(unsigned long val)
 39{
 40	int ret = blocking_notifier_call_chain(&pm_chain_head, val, NULL);
 41
 42	return notifier_to_errno(ret);
 43}
 44
 45/* If set, devices may be suspended and resumed asynchronously. */
 46int pm_async_enabled = 1;
 47
 48static ssize_t pm_async_show(struct kobject *kobj, struct kobj_attribute *attr,
 49			     char *buf)
 50{
 51	return sprintf(buf, "%d\n", pm_async_enabled);
 52}
 53
 54static ssize_t pm_async_store(struct kobject *kobj, struct kobj_attribute *attr,
 55			      const char *buf, size_t n)
 56{
 57	unsigned long val;
 58
 59	if (strict_strtoul(buf, 10, &val))
 60		return -EINVAL;
 61
 62	if (val > 1)
 63		return -EINVAL;
 64
 65	pm_async_enabled = val;
 66	return n;
 67}
 68
 69power_attr(pm_async);
 70
 71#ifdef CONFIG_PM_DEBUG
 72int pm_test_level = TEST_NONE;
 73
 74static const char * const pm_tests[__TEST_AFTER_LAST] = {
 75	[TEST_NONE] = "none",
 76	[TEST_CORE] = "core",
 77	[TEST_CPUS] = "processors",
 78	[TEST_PLATFORM] = "platform",
 79	[TEST_DEVICES] = "devices",
 80	[TEST_FREEZER] = "freezer",
 81};
 82
 83static ssize_t pm_test_show(struct kobject *kobj, struct kobj_attribute *attr,
 84				char *buf)
 85{
 86	char *s = buf;
 87	int level;
 88
 89	for (level = TEST_FIRST; level <= TEST_MAX; level++)
 90		if (pm_tests[level]) {
 91			if (level == pm_test_level)
 92				s += sprintf(s, "[%s] ", pm_tests[level]);
 93			else
 94				s += sprintf(s, "%s ", pm_tests[level]);
 95		}
 96
 97	if (s != buf)
 98		/* convert the last space to a newline */
 99		*(s-1) = '\n';
100
101	return (s - buf);
102}
103
104static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
105				const char *buf, size_t n)
106{
107	const char * const *s;
108	int level;
109	char *p;
110	int len;
111	int error = -EINVAL;
112
113	p = memchr(buf, '\n', n);
114	len = p ? p - buf : n;
115
116	mutex_lock(&pm_mutex);
117
118	level = TEST_FIRST;
119	for (s = &pm_tests[level]; level <= TEST_MAX; s++, level++)
120		if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) {
121			pm_test_level = level;
122			error = 0;
123			break;
124		}
125
126	mutex_unlock(&pm_mutex);
127
128	return error ? error : n;
129}
130
131power_attr(pm_test);
132#endif /* CONFIG_PM_DEBUG */
133
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
134#endif /* CONFIG_PM_SLEEP */
135
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
136struct kobject *power_kobj;
137
138/**
139 *	state - control system power state.
140 *
141 *	show() returns what states are supported, which is hard-coded to
142 *	'standby' (Power-On Suspend), 'mem' (Suspend-to-RAM), and
143 *	'disk' (Suspend-to-Disk).
144 *
145 *	store() accepts one of those strings, translates it into the 
146 *	proper enumerated value, and initiates a suspend transition.
147 */
148static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
149			  char *buf)
150{
151	char *s = buf;
152#ifdef CONFIG_SUSPEND
153	int i;
154
155	for (i = 0; i < PM_SUSPEND_MAX; i++) {
156		if (pm_states[i] && valid_state(i))
157			s += sprintf(s,"%s ", pm_states[i]);
158	}
159#endif
160#ifdef CONFIG_HIBERNATION
161	s += sprintf(s, "%s\n", "disk");
162#else
163	if (s != buf)
164		/* convert the last space to a newline */
165		*(s-1) = '\n';
166#endif
167	return (s - buf);
168}
169
170static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
171			   const char *buf, size_t n)
172{
173#ifdef CONFIG_SUSPEND
174	suspend_state_t state = PM_SUSPEND_STANDBY;
175	const char * const *s;
176#endif
177	char *p;
178	int len;
179	int error = -EINVAL;
180
181	p = memchr(buf, '\n', n);
182	len = p ? p - buf : n;
183
184	/* First, check if we are requested to hibernate */
185	if (len == 4 && !strncmp(buf, "disk", len)) {
186		error = hibernate();
187  goto Exit;
188	}
189
190#ifdef CONFIG_SUSPEND
191	for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++) {
192		if (*s && len == strlen(*s) && !strncmp(buf, *s, len))
193			break;
194	}
195	if (state < PM_SUSPEND_MAX && *s)
196		error = enter_state(state);
197#endif
198
199 Exit:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
200	return error ? error : n;
201}
202
203power_attr(state);
204
205#ifdef CONFIG_PM_SLEEP
206/*
207 * The 'wakeup_count' attribute, along with the functions defined in
208 * drivers/base/power/wakeup.c, provides a means by which wakeup events can be
209 * handled in a non-racy way.
210 *
211 * If a wakeup event occurs when the system is in a sleep state, it simply is
212 * woken up.  In turn, if an event that would wake the system up from a sleep
213 * state occurs when it is undergoing a transition to that sleep state, the
214 * transition should be aborted.  Moreover, if such an event occurs when the
215 * system is in the working state, an attempt to start a transition to the
216 * given sleep state should fail during certain period after the detection of
217 * the event.  Using the 'state' attribute alone is not sufficient to satisfy
218 * these requirements, because a wakeup event may occur exactly when 'state'
219 * is being written to and may be delivered to user space right before it is
220 * frozen, so the event will remain only partially processed until the system is
221 * woken up by another event.  In particular, it won't cause the transition to
222 * a sleep state to be aborted.
223 *
224 * This difficulty may be overcome if user space uses 'wakeup_count' before
225 * writing to 'state'.  It first should read from 'wakeup_count' and store
226 * the read value.  Then, after carrying out its own preparations for the system
227 * transition to a sleep state, it should write the stored value to
228 * 'wakeup_count'.  If that fails, at least one wakeup event has occurred since
229 * 'wakeup_count' was read and 'state' should not be written to.  Otherwise, it
230 * is allowed to write to 'state', but the transition will be aborted if there
231 * are any wakeup events detected after 'wakeup_count' was written to.
232 */
233
234static ssize_t wakeup_count_show(struct kobject *kobj,
235				struct kobj_attribute *attr,
236				char *buf)
237{
238	unsigned int val;
239
240	return pm_get_wakeup_count(&val) ? sprintf(buf, "%u\n", val) : -EINTR;
 
241}
242
243static ssize_t wakeup_count_store(struct kobject *kobj,
244				struct kobj_attribute *attr,
245				const char *buf, size_t n)
246{
247	unsigned int val;
 
248
 
 
 
 
 
 
 
 
 
 
249	if (sscanf(buf, "%u", &val) == 1) {
250		if (pm_save_wakeup_count(val))
251			return n;
 
 
252	}
253	return -EINVAL;
 
 
 
254}
255
256power_attr(wakeup_count);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
257#endif /* CONFIG_PM_SLEEP */
258
259#ifdef CONFIG_PM_TRACE
260int pm_trace_enabled;
261
262static ssize_t pm_trace_show(struct kobject *kobj, struct kobj_attribute *attr,
263			     char *buf)
264{
265	return sprintf(buf, "%d\n", pm_trace_enabled);
266}
267
268static ssize_t
269pm_trace_store(struct kobject *kobj, struct kobj_attribute *attr,
270	       const char *buf, size_t n)
271{
272	int val;
273
274	if (sscanf(buf, "%d", &val) == 1) {
275		pm_trace_enabled = !!val;
 
 
 
 
276		return n;
277	}
278	return -EINVAL;
279}
280
281power_attr(pm_trace);
282
283static ssize_t pm_trace_dev_match_show(struct kobject *kobj,
284				       struct kobj_attribute *attr,
285				       char *buf)
286{
287	return show_trace_dev_match(buf, PAGE_SIZE);
288}
289
290static ssize_t
291pm_trace_dev_match_store(struct kobject *kobj, struct kobj_attribute *attr,
292			 const char *buf, size_t n)
293{
294	return -EINVAL;
295}
296
297power_attr(pm_trace_dev_match);
298
299#endif /* CONFIG_PM_TRACE */
300
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
301static struct attribute * g[] = {
302	&state_attr.attr,
303#ifdef CONFIG_PM_TRACE
304	&pm_trace_attr.attr,
305	&pm_trace_dev_match_attr.attr,
306#endif
307#ifdef CONFIG_PM_SLEEP
308	&pm_async_attr.attr,
309	&wakeup_count_attr.attr,
 
 
 
 
 
 
 
310#ifdef CONFIG_PM_DEBUG
311	&pm_test_attr.attr,
312#endif
 
 
 
 
 
 
313#endif
314	NULL,
315};
316
317static struct attribute_group attr_group = {
318	.attrs = g,
319};
320
321#ifdef CONFIG_PM_RUNTIME
322struct workqueue_struct *pm_wq;
323EXPORT_SYMBOL_GPL(pm_wq);
324
325static int __init pm_start_workqueue(void)
326{
327	pm_wq = alloc_workqueue("pm", WQ_FREEZABLE, 0);
328
329	return pm_wq ? 0 : -ENOMEM;
330}
331#else
332static inline int pm_start_workqueue(void) { return 0; }
333#endif
334
335static int __init pm_init(void)
336{
337	int error = pm_start_workqueue();
338	if (error)
339		return error;
340	hibernate_image_size_init();
341	hibernate_reserved_size_init();
342	power_kobj = kobject_create_and_add("power", NULL);
343	if (!power_kobj)
344		return -ENOMEM;
345	return sysfs_create_group(power_kobj, &attr_group);
 
 
 
 
346}
347
348core_initcall(pm_init);
v3.15
  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
 11#include <linux/export.h>
 12#include <linux/kobject.h>
 13#include <linux/string.h>
 14#include <linux/resume-trace.h>
 15#include <linux/workqueue.h>
 16#include <linux/debugfs.h>
 17#include <linux/seq_file.h>
 18
 19#include "power.h"
 20
 21DEFINE_MUTEX(pm_mutex);
 22
 23#ifdef CONFIG_PM_SLEEP
 24
 25/* Routines for PM-transition notifications */
 26
 27static BLOCKING_NOTIFIER_HEAD(pm_chain_head);
 28
 29int register_pm_notifier(struct notifier_block *nb)
 30{
 31	return blocking_notifier_chain_register(&pm_chain_head, nb);
 32}
 33EXPORT_SYMBOL_GPL(register_pm_notifier);
 34
 35int unregister_pm_notifier(struct notifier_block *nb)
 36{
 37	return blocking_notifier_chain_unregister(&pm_chain_head, nb);
 38}
 39EXPORT_SYMBOL_GPL(unregister_pm_notifier);
 40
 41int pm_notifier_call_chain(unsigned long val)
 42{
 43	int ret = blocking_notifier_call_chain(&pm_chain_head, val, NULL);
 44
 45	return notifier_to_errno(ret);
 46}
 47
 48/* If set, devices may be suspended and resumed asynchronously. */
 49int pm_async_enabled = 1;
 50
 51static ssize_t pm_async_show(struct kobject *kobj, struct kobj_attribute *attr,
 52			     char *buf)
 53{
 54	return sprintf(buf, "%d\n", pm_async_enabled);
 55}
 56
 57static ssize_t pm_async_store(struct kobject *kobj, struct kobj_attribute *attr,
 58			      const char *buf, size_t n)
 59{
 60	unsigned long val;
 61
 62	if (kstrtoul(buf, 10, &val))
 63		return -EINVAL;
 64
 65	if (val > 1)
 66		return -EINVAL;
 67
 68	pm_async_enabled = val;
 69	return n;
 70}
 71
 72power_attr(pm_async);
 73
 74#ifdef CONFIG_PM_DEBUG
 75int pm_test_level = TEST_NONE;
 76
 77static const char * const pm_tests[__TEST_AFTER_LAST] = {
 78	[TEST_NONE] = "none",
 79	[TEST_CORE] = "core",
 80	[TEST_CPUS] = "processors",
 81	[TEST_PLATFORM] = "platform",
 82	[TEST_DEVICES] = "devices",
 83	[TEST_FREEZER] = "freezer",
 84};
 85
 86static ssize_t pm_test_show(struct kobject *kobj, struct kobj_attribute *attr,
 87				char *buf)
 88{
 89	char *s = buf;
 90	int level;
 91
 92	for (level = TEST_FIRST; level <= TEST_MAX; level++)
 93		if (pm_tests[level]) {
 94			if (level == pm_test_level)
 95				s += sprintf(s, "[%s] ", pm_tests[level]);
 96			else
 97				s += sprintf(s, "%s ", pm_tests[level]);
 98		}
 99
100	if (s != buf)
101		/* convert the last space to a newline */
102		*(s-1) = '\n';
103
104	return (s - buf);
105}
106
107static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
108				const char *buf, size_t n)
109{
110	const char * const *s;
111	int level;
112	char *p;
113	int len;
114	int error = -EINVAL;
115
116	p = memchr(buf, '\n', n);
117	len = p ? p - buf : n;
118
119	lock_system_sleep();
120
121	level = TEST_FIRST;
122	for (s = &pm_tests[level]; level <= TEST_MAX; s++, level++)
123		if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) {
124			pm_test_level = level;
125			error = 0;
126			break;
127		}
128
129	unlock_system_sleep();
130
131	return error ? error : n;
132}
133
134power_attr(pm_test);
135#endif /* CONFIG_PM_DEBUG */
136
137#ifdef CONFIG_DEBUG_FS
138static char *suspend_step_name(enum suspend_stat_step step)
139{
140	switch (step) {
141	case SUSPEND_FREEZE:
142		return "freeze";
143	case SUSPEND_PREPARE:
144		return "prepare";
145	case SUSPEND_SUSPEND:
146		return "suspend";
147	case SUSPEND_SUSPEND_NOIRQ:
148		return "suspend_noirq";
149	case SUSPEND_RESUME_NOIRQ:
150		return "resume_noirq";
151	case SUSPEND_RESUME:
152		return "resume";
153	default:
154		return "";
155	}
156}
157
158static int suspend_stats_show(struct seq_file *s, void *unused)
159{
160	int i, index, last_dev, last_errno, last_step;
161
162	last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
163	last_dev %= REC_FAILED_NUM;
164	last_errno = suspend_stats.last_failed_errno + REC_FAILED_NUM - 1;
165	last_errno %= REC_FAILED_NUM;
166	last_step = suspend_stats.last_failed_step + REC_FAILED_NUM - 1;
167	last_step %= REC_FAILED_NUM;
168	seq_printf(s, "%s: %d\n%s: %d\n%s: %d\n%s: %d\n%s: %d\n"
169			"%s: %d\n%s: %d\n%s: %d\n%s: %d\n%s: %d\n",
170			"success", suspend_stats.success,
171			"fail", suspend_stats.fail,
172			"failed_freeze", suspend_stats.failed_freeze,
173			"failed_prepare", suspend_stats.failed_prepare,
174			"failed_suspend", suspend_stats.failed_suspend,
175			"failed_suspend_late",
176				suspend_stats.failed_suspend_late,
177			"failed_suspend_noirq",
178				suspend_stats.failed_suspend_noirq,
179			"failed_resume", suspend_stats.failed_resume,
180			"failed_resume_early",
181				suspend_stats.failed_resume_early,
182			"failed_resume_noirq",
183				suspend_stats.failed_resume_noirq);
184	seq_printf(s,	"failures:\n  last_failed_dev:\t%-s\n",
185			suspend_stats.failed_devs[last_dev]);
186	for (i = 1; i < REC_FAILED_NUM; i++) {
187		index = last_dev + REC_FAILED_NUM - i;
188		index %= REC_FAILED_NUM;
189		seq_printf(s, "\t\t\t%-s\n",
190			suspend_stats.failed_devs[index]);
191	}
192	seq_printf(s,	"  last_failed_errno:\t%-d\n",
193			suspend_stats.errno[last_errno]);
194	for (i = 1; i < REC_FAILED_NUM; i++) {
195		index = last_errno + REC_FAILED_NUM - i;
196		index %= REC_FAILED_NUM;
197		seq_printf(s, "\t\t\t%-d\n",
198			suspend_stats.errno[index]);
199	}
200	seq_printf(s,	"  last_failed_step:\t%-s\n",
201			suspend_step_name(
202				suspend_stats.failed_steps[last_step]));
203	for (i = 1; i < REC_FAILED_NUM; i++) {
204		index = last_step + REC_FAILED_NUM - i;
205		index %= REC_FAILED_NUM;
206		seq_printf(s, "\t\t\t%-s\n",
207			suspend_step_name(
208				suspend_stats.failed_steps[index]));
209	}
210
211	return 0;
212}
213
214static int suspend_stats_open(struct inode *inode, struct file *file)
215{
216	return single_open(file, suspend_stats_show, NULL);
217}
218
219static const struct file_operations suspend_stats_operations = {
220	.open           = suspend_stats_open,
221	.read           = seq_read,
222	.llseek         = seq_lseek,
223	.release        = single_release,
224};
225
226static int __init pm_debugfs_init(void)
227{
228	debugfs_create_file("suspend_stats", S_IFREG | S_IRUGO,
229			NULL, NULL, &suspend_stats_operations);
230	return 0;
231}
232
233late_initcall(pm_debugfs_init);
234#endif /* CONFIG_DEBUG_FS */
235
236#endif /* CONFIG_PM_SLEEP */
237
238#ifdef CONFIG_PM_SLEEP_DEBUG
239/*
240 * pm_print_times: print time taken by devices to suspend and resume.
241 *
242 * show() returns whether printing of suspend and resume times is enabled.
243 * store() accepts 0 or 1.  0 disables printing and 1 enables it.
244 */
245bool pm_print_times_enabled;
246
247static ssize_t pm_print_times_show(struct kobject *kobj,
248				   struct kobj_attribute *attr, char *buf)
249{
250	return sprintf(buf, "%d\n", pm_print_times_enabled);
251}
252
253static ssize_t pm_print_times_store(struct kobject *kobj,
254				    struct kobj_attribute *attr,
255				    const char *buf, size_t n)
256{
257	unsigned long val;
258
259	if (kstrtoul(buf, 10, &val))
260		return -EINVAL;
261
262	if (val > 1)
263		return -EINVAL;
264
265	pm_print_times_enabled = !!val;
266	return n;
267}
268
269power_attr(pm_print_times);
270
271static inline void pm_print_times_init(void)
272{
273	pm_print_times_enabled = !!initcall_debug;
274}
275#else /* !CONFIG_PP_SLEEP_DEBUG */
276static inline void pm_print_times_init(void) {}
277#endif /* CONFIG_PM_SLEEP_DEBUG */
278
279struct kobject *power_kobj;
280
281/**
282 *	state - control system power state.
283 *
284 *	show() returns what states are supported, which is hard-coded to
285 *	'freeze' (Low-Power Idle), 'standby' (Power-On Suspend),
286 *	'mem' (Suspend-to-RAM), and 'disk' (Suspend-to-Disk).
287 *
288 *	store() accepts one of those strings, translates it into the
289 *	proper enumerated value, and initiates a suspend transition.
290 */
291static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
292			  char *buf)
293{
294	char *s = buf;
295#ifdef CONFIG_SUSPEND
296	int i;
297
298	for (i = 0; i < PM_SUSPEND_MAX; i++) {
299		if (pm_states[i] && valid_state(i))
300			s += sprintf(s,"%s ", pm_states[i]);
301	}
302#endif
303#ifdef CONFIG_HIBERNATION
304	s += sprintf(s, "%s\n", "disk");
305#else
306	if (s != buf)
307		/* convert the last space to a newline */
308		*(s-1) = '\n';
309#endif
310	return (s - buf);
311}
312
313static suspend_state_t decode_state(const char *buf, size_t n)
 
314{
315#ifdef CONFIG_SUSPEND
316	suspend_state_t state = PM_SUSPEND_MIN;
317	const char * const *s;
318#endif
319	char *p;
320	int len;
 
321
322	p = memchr(buf, '\n', n);
323	len = p ? p - buf : n;
324
325	/* Check hibernation first. */
326	if (len == 4 && !strncmp(buf, "disk", len))
327		return PM_SUSPEND_MAX;
 
 
328
329#ifdef CONFIG_SUSPEND
330	for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++)
331		if (*s && len == strlen(*s) && !strncmp(buf, *s, len))
332			return state;
 
 
 
333#endif
334
335	return PM_SUSPEND_ON;
336}
337
338static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
339			   const char *buf, size_t n)
340{
341	suspend_state_t state;
342	int error;
343
344	error = pm_autosleep_lock();
345	if (error)
346		return error;
347
348	if (pm_autosleep_state() > PM_SUSPEND_ON) {
349		error = -EBUSY;
350		goto out;
351	}
352
353	state = decode_state(buf, n);
354	if (state < PM_SUSPEND_MAX)
355		error = pm_suspend(state);
356	else if (state == PM_SUSPEND_MAX)
357		error = hibernate();
358	else
359		error = -EINVAL;
360
361 out:
362	pm_autosleep_unlock();
363	return error ? error : n;
364}
365
366power_attr(state);
367
368#ifdef CONFIG_PM_SLEEP
369/*
370 * The 'wakeup_count' attribute, along with the functions defined in
371 * drivers/base/power/wakeup.c, provides a means by which wakeup events can be
372 * handled in a non-racy way.
373 *
374 * If a wakeup event occurs when the system is in a sleep state, it simply is
375 * woken up.  In turn, if an event that would wake the system up from a sleep
376 * state occurs when it is undergoing a transition to that sleep state, the
377 * transition should be aborted.  Moreover, if such an event occurs when the
378 * system is in the working state, an attempt to start a transition to the
379 * given sleep state should fail during certain period after the detection of
380 * the event.  Using the 'state' attribute alone is not sufficient to satisfy
381 * these requirements, because a wakeup event may occur exactly when 'state'
382 * is being written to and may be delivered to user space right before it is
383 * frozen, so the event will remain only partially processed until the system is
384 * woken up by another event.  In particular, it won't cause the transition to
385 * a sleep state to be aborted.
386 *
387 * This difficulty may be overcome if user space uses 'wakeup_count' before
388 * writing to 'state'.  It first should read from 'wakeup_count' and store
389 * the read value.  Then, after carrying out its own preparations for the system
390 * transition to a sleep state, it should write the stored value to
391 * 'wakeup_count'.  If that fails, at least one wakeup event has occurred since
392 * 'wakeup_count' was read and 'state' should not be written to.  Otherwise, it
393 * is allowed to write to 'state', but the transition will be aborted if there
394 * are any wakeup events detected after 'wakeup_count' was written to.
395 */
396
397static ssize_t wakeup_count_show(struct kobject *kobj,
398				struct kobj_attribute *attr,
399				char *buf)
400{
401	unsigned int val;
402
403	return pm_get_wakeup_count(&val, true) ?
404		sprintf(buf, "%u\n", val) : -EINTR;
405}
406
407static ssize_t wakeup_count_store(struct kobject *kobj,
408				struct kobj_attribute *attr,
409				const char *buf, size_t n)
410{
411	unsigned int val;
412	int error;
413
414	error = pm_autosleep_lock();
415	if (error)
416		return error;
417
418	if (pm_autosleep_state() > PM_SUSPEND_ON) {
419		error = -EBUSY;
420		goto out;
421	}
422
423	error = -EINVAL;
424	if (sscanf(buf, "%u", &val) == 1) {
425		if (pm_save_wakeup_count(val))
426			error = n;
427		else
428			pm_print_active_wakeup_sources();
429	}
430
431 out:
432	pm_autosleep_unlock();
433	return error;
434}
435
436power_attr(wakeup_count);
437
438#ifdef CONFIG_PM_AUTOSLEEP
439static ssize_t autosleep_show(struct kobject *kobj,
440			      struct kobj_attribute *attr,
441			      char *buf)
442{
443	suspend_state_t state = pm_autosleep_state();
444
445	if (state == PM_SUSPEND_ON)
446		return sprintf(buf, "off\n");
447
448#ifdef CONFIG_SUSPEND
449	if (state < PM_SUSPEND_MAX)
450		return sprintf(buf, "%s\n", valid_state(state) ?
451						pm_states[state] : "error");
452#endif
453#ifdef CONFIG_HIBERNATION
454	return sprintf(buf, "disk\n");
455#else
456	return sprintf(buf, "error");
457#endif
458}
459
460static ssize_t autosleep_store(struct kobject *kobj,
461			       struct kobj_attribute *attr,
462			       const char *buf, size_t n)
463{
464	suspend_state_t state = decode_state(buf, n);
465	int error;
466
467	if (state == PM_SUSPEND_ON
468	    && strcmp(buf, "off") && strcmp(buf, "off\n"))
469		return -EINVAL;
470
471	error = pm_autosleep_set_state(state);
472	return error ? error : n;
473}
474
475power_attr(autosleep);
476#endif /* CONFIG_PM_AUTOSLEEP */
477
478#ifdef CONFIG_PM_WAKELOCKS
479static ssize_t wake_lock_show(struct kobject *kobj,
480			      struct kobj_attribute *attr,
481			      char *buf)
482{
483	return pm_show_wakelocks(buf, true);
484}
485
486static ssize_t wake_lock_store(struct kobject *kobj,
487			       struct kobj_attribute *attr,
488			       const char *buf, size_t n)
489{
490	int error = pm_wake_lock(buf);
491	return error ? error : n;
492}
493
494power_attr(wake_lock);
495
496static ssize_t wake_unlock_show(struct kobject *kobj,
497				struct kobj_attribute *attr,
498				char *buf)
499{
500	return pm_show_wakelocks(buf, false);
501}
502
503static ssize_t wake_unlock_store(struct kobject *kobj,
504				 struct kobj_attribute *attr,
505				 const char *buf, size_t n)
506{
507	int error = pm_wake_unlock(buf);
508	return error ? error : n;
509}
510
511power_attr(wake_unlock);
512
513#endif /* CONFIG_PM_WAKELOCKS */
514#endif /* CONFIG_PM_SLEEP */
515
516#ifdef CONFIG_PM_TRACE
517int pm_trace_enabled;
518
519static ssize_t pm_trace_show(struct kobject *kobj, struct kobj_attribute *attr,
520			     char *buf)
521{
522	return sprintf(buf, "%d\n", pm_trace_enabled);
523}
524
525static ssize_t
526pm_trace_store(struct kobject *kobj, struct kobj_attribute *attr,
527	       const char *buf, size_t n)
528{
529	int val;
530
531	if (sscanf(buf, "%d", &val) == 1) {
532		pm_trace_enabled = !!val;
533		if (pm_trace_enabled) {
534			pr_warn("PM: Enabling pm_trace changes system date and time during resume.\n"
535				"PM: Correct system time has to be restored manually after resume.\n");
536		}
537		return n;
538	}
539	return -EINVAL;
540}
541
542power_attr(pm_trace);
543
544static ssize_t pm_trace_dev_match_show(struct kobject *kobj,
545				       struct kobj_attribute *attr,
546				       char *buf)
547{
548	return show_trace_dev_match(buf, PAGE_SIZE);
549}
550
551static ssize_t
552pm_trace_dev_match_store(struct kobject *kobj, struct kobj_attribute *attr,
553			 const char *buf, size_t n)
554{
555	return -EINVAL;
556}
557
558power_attr(pm_trace_dev_match);
559
560#endif /* CONFIG_PM_TRACE */
561
562#ifdef CONFIG_FREEZER
563static ssize_t pm_freeze_timeout_show(struct kobject *kobj,
564				      struct kobj_attribute *attr, char *buf)
565{
566	return sprintf(buf, "%u\n", freeze_timeout_msecs);
567}
568
569static ssize_t pm_freeze_timeout_store(struct kobject *kobj,
570				       struct kobj_attribute *attr,
571				       const char *buf, size_t n)
572{
573	unsigned long val;
574
575	if (kstrtoul(buf, 10, &val))
576		return -EINVAL;
577
578	freeze_timeout_msecs = val;
579	return n;
580}
581
582power_attr(pm_freeze_timeout);
583
584#endif	/* CONFIG_FREEZER*/
585
586static struct attribute * g[] = {
587	&state_attr.attr,
588#ifdef CONFIG_PM_TRACE
589	&pm_trace_attr.attr,
590	&pm_trace_dev_match_attr.attr,
591#endif
592#ifdef CONFIG_PM_SLEEP
593	&pm_async_attr.attr,
594	&wakeup_count_attr.attr,
595#ifdef CONFIG_PM_AUTOSLEEP
596	&autosleep_attr.attr,
597#endif
598#ifdef CONFIG_PM_WAKELOCKS
599	&wake_lock_attr.attr,
600	&wake_unlock_attr.attr,
601#endif
602#ifdef CONFIG_PM_DEBUG
603	&pm_test_attr.attr,
604#endif
605#ifdef CONFIG_PM_SLEEP_DEBUG
606	&pm_print_times_attr.attr,
607#endif
608#endif
609#ifdef CONFIG_FREEZER
610	&pm_freeze_timeout_attr.attr,
611#endif
612	NULL,
613};
614
615static struct attribute_group attr_group = {
616	.attrs = g,
617};
618
619#ifdef CONFIG_PM_RUNTIME
620struct workqueue_struct *pm_wq;
621EXPORT_SYMBOL_GPL(pm_wq);
622
623static int __init pm_start_workqueue(void)
624{
625	pm_wq = alloc_workqueue("pm", WQ_FREEZABLE, 0);
626
627	return pm_wq ? 0 : -ENOMEM;
628}
629#else
630static inline int pm_start_workqueue(void) { return 0; }
631#endif
632
633static int __init pm_init(void)
634{
635	int error = pm_start_workqueue();
636	if (error)
637		return error;
638	hibernate_image_size_init();
639	hibernate_reserved_size_init();
640	power_kobj = kobject_create_and_add("power", NULL);
641	if (!power_kobj)
642		return -ENOMEM;
643	error = sysfs_create_group(power_kobj, &attr_group);
644	if (error)
645		return error;
646	pm_print_times_init();
647	return pm_autosleep_init();
648}
649
650core_initcall(pm_init);