2 * kernel/power/main.c - PM subsystem core functionality.
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Open Source Development Lab
7 * This file is released under the GPLv2
11 #include <linux/export.h>
12 #include <linux/kobject.h>
13 #include <linux/string.h>
14 #include <linux/pm-trace.h>
15 #include <linux/workqueue.h>
16 #include <linux/debugfs.h>
17 #include <linux/seq_file.h>
21 DEFINE_MUTEX(pm_mutex);
23 #ifdef CONFIG_PM_SLEEP
25 /* Routines for PM-transition notifications */
27 static BLOCKING_NOTIFIER_HEAD(pm_chain_head);
29 int register_pm_notifier(struct notifier_block *nb)
31 return blocking_notifier_chain_register(&pm_chain_head, nb);
33 EXPORT_SYMBOL_GPL(register_pm_notifier);
35 int unregister_pm_notifier(struct notifier_block *nb)
37 return blocking_notifier_chain_unregister(&pm_chain_head, nb);
39 EXPORT_SYMBOL_GPL(unregister_pm_notifier);
41 int __pm_notifier_call_chain(unsigned long val, int nr_to_call, int *nr_calls)
45 ret = __blocking_notifier_call_chain(&pm_chain_head, val, NULL,
46 nr_to_call, nr_calls);
48 return notifier_to_errno(ret);
50 int pm_notifier_call_chain(unsigned long val)
52 return __pm_notifier_call_chain(val, -1, NULL);
55 /* If set, devices may be suspended and resumed asynchronously. */
56 int pm_async_enabled = 1;
58 static ssize_t pm_async_show(struct kobject *kobj, struct kobj_attribute *attr,
61 return sprintf(buf, "%d\n", pm_async_enabled);
64 static ssize_t pm_async_store(struct kobject *kobj, struct kobj_attribute *attr,
65 const char *buf, size_t n)
69 if (kstrtoul(buf, 10, &val))
75 pm_async_enabled = val;
82 static ssize_t mem_sleep_show(struct kobject *kobj, struct kobj_attribute *attr,
88 for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++)
89 if (mem_sleep_states[i]) {
90 const char *label = mem_sleep_states[i];
92 if (mem_sleep_current == i)
93 s += sprintf(s, "[%s] ", label);
95 s += sprintf(s, "%s ", label);
98 /* Convert the last space to a newline if needed. */
105 static suspend_state_t decode_suspend_state(const char *buf, size_t n)
107 suspend_state_t state;
111 p = memchr(buf, '\n', n);
112 len = p ? p - buf : n;
114 for (state = PM_SUSPEND_MIN; state < PM_SUSPEND_MAX; state++) {
115 const char *label = mem_sleep_states[state];
117 if (label && len == strlen(label) && !strncmp(buf, label, len))
121 return PM_SUSPEND_ON;
124 static ssize_t mem_sleep_store(struct kobject *kobj, struct kobj_attribute *attr,
125 const char *buf, size_t n)
127 suspend_state_t state;
130 error = pm_autosleep_lock();
134 if (pm_autosleep_state() > PM_SUSPEND_ON) {
139 state = decode_suspend_state(buf, n);
140 if (state < PM_SUSPEND_MAX && state > PM_SUSPEND_ON)
141 mem_sleep_current = state;
146 pm_autosleep_unlock();
147 return error ? error : n;
150 power_attr(mem_sleep);
151 #endif /* CONFIG_SUSPEND */
153 #ifdef CONFIG_PM_SLEEP_DEBUG
154 int pm_test_level = TEST_NONE;
156 static const char * const pm_tests[__TEST_AFTER_LAST] = {
157 [TEST_NONE] = "none",
158 [TEST_CORE] = "core",
159 [TEST_CPUS] = "processors",
160 [TEST_PLATFORM] = "platform",
161 [TEST_DEVICES] = "devices",
162 [TEST_FREEZER] = "freezer",
165 static ssize_t pm_test_show(struct kobject *kobj, struct kobj_attribute *attr,
171 for (level = TEST_FIRST; level <= TEST_MAX; level++)
172 if (pm_tests[level]) {
173 if (level == pm_test_level)
174 s += sprintf(s, "[%s] ", pm_tests[level]);
176 s += sprintf(s, "%s ", pm_tests[level]);
180 /* convert the last space to a newline */
186 static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
187 const char *buf, size_t n)
189 const char * const *s;
195 p = memchr(buf, '\n', n);
196 len = p ? p - buf : n;
201 for (s = &pm_tests[level]; level <= TEST_MAX; s++, level++)
202 if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) {
203 pm_test_level = level;
208 unlock_system_sleep();
210 return error ? error : n;
214 #endif /* CONFIG_PM_SLEEP_DEBUG */
216 #ifdef CONFIG_DEBUG_FS
217 static char *suspend_step_name(enum suspend_stat_step step)
222 case SUSPEND_PREPARE:
224 case SUSPEND_SUSPEND:
226 case SUSPEND_SUSPEND_NOIRQ:
227 return "suspend_noirq";
228 case SUSPEND_RESUME_NOIRQ:
229 return "resume_noirq";
237 static int suspend_stats_show(struct seq_file *s, void *unused)
239 int i, index, last_dev, last_errno, last_step;
241 last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
242 last_dev %= REC_FAILED_NUM;
243 last_errno = suspend_stats.last_failed_errno + REC_FAILED_NUM - 1;
244 last_errno %= REC_FAILED_NUM;
245 last_step = suspend_stats.last_failed_step + REC_FAILED_NUM - 1;
246 last_step %= REC_FAILED_NUM;
247 seq_printf(s, "%s: %d\n%s: %d\n%s: %d\n%s: %d\n%s: %d\n"
248 "%s: %d\n%s: %d\n%s: %d\n%s: %d\n%s: %d\n",
249 "success", suspend_stats.success,
250 "fail", suspend_stats.fail,
251 "failed_freeze", suspend_stats.failed_freeze,
252 "failed_prepare", suspend_stats.failed_prepare,
253 "failed_suspend", suspend_stats.failed_suspend,
254 "failed_suspend_late",
255 suspend_stats.failed_suspend_late,
256 "failed_suspend_noirq",
257 suspend_stats.failed_suspend_noirq,
258 "failed_resume", suspend_stats.failed_resume,
259 "failed_resume_early",
260 suspend_stats.failed_resume_early,
261 "failed_resume_noirq",
262 suspend_stats.failed_resume_noirq);
263 seq_printf(s, "failures:\n last_failed_dev:\t%-s\n",
264 suspend_stats.failed_devs[last_dev]);
265 for (i = 1; i < REC_FAILED_NUM; i++) {
266 index = last_dev + REC_FAILED_NUM - i;
267 index %= REC_FAILED_NUM;
268 seq_printf(s, "\t\t\t%-s\n",
269 suspend_stats.failed_devs[index]);
271 seq_printf(s, " last_failed_errno:\t%-d\n",
272 suspend_stats.errno[last_errno]);
273 for (i = 1; i < REC_FAILED_NUM; i++) {
274 index = last_errno + REC_FAILED_NUM - i;
275 index %= REC_FAILED_NUM;
276 seq_printf(s, "\t\t\t%-d\n",
277 suspend_stats.errno[index]);
279 seq_printf(s, " last_failed_step:\t%-s\n",
281 suspend_stats.failed_steps[last_step]));
282 for (i = 1; i < REC_FAILED_NUM; i++) {
283 index = last_step + REC_FAILED_NUM - i;
284 index %= REC_FAILED_NUM;
285 seq_printf(s, "\t\t\t%-s\n",
287 suspend_stats.failed_steps[index]));
293 static int suspend_stats_open(struct inode *inode, struct file *file)
295 return single_open(file, suspend_stats_show, NULL);
298 static const struct file_operations suspend_stats_operations = {
299 .open = suspend_stats_open,
302 .release = single_release,
305 static int __init pm_debugfs_init(void)
307 debugfs_create_file("suspend_stats", S_IFREG | S_IRUGO,
308 NULL, NULL, &suspend_stats_operations);
312 late_initcall(pm_debugfs_init);
313 #endif /* CONFIG_DEBUG_FS */
315 #endif /* CONFIG_PM_SLEEP */
317 #ifdef CONFIG_PM_SLEEP_DEBUG
319 * pm_print_times: print time taken by devices to suspend and resume.
321 * show() returns whether printing of suspend and resume times is enabled.
322 * store() accepts 0 or 1. 0 disables printing and 1 enables it.
324 bool pm_print_times_enabled;
326 static ssize_t pm_print_times_show(struct kobject *kobj,
327 struct kobj_attribute *attr, char *buf)
329 return sprintf(buf, "%d\n", pm_print_times_enabled);
332 static ssize_t pm_print_times_store(struct kobject *kobj,
333 struct kobj_attribute *attr,
334 const char *buf, size_t n)
338 if (kstrtoul(buf, 10, &val))
344 pm_print_times_enabled = !!val;
348 power_attr(pm_print_times);
350 static inline void pm_print_times_init(void)
352 pm_print_times_enabled = !!initcall_debug;
355 static ssize_t pm_wakeup_irq_show(struct kobject *kobj,
356 struct kobj_attribute *attr,
359 return pm_wakeup_irq ? sprintf(buf, "%u\n", pm_wakeup_irq) : -ENODATA;
362 power_attr_ro(pm_wakeup_irq);
364 bool pm_debug_messages_on __read_mostly;
366 static ssize_t pm_debug_messages_show(struct kobject *kobj,
367 struct kobj_attribute *attr, char *buf)
369 return sprintf(buf, "%d\n", pm_debug_messages_on);
372 static ssize_t pm_debug_messages_store(struct kobject *kobj,
373 struct kobj_attribute *attr,
374 const char *buf, size_t n)
378 if (kstrtoul(buf, 10, &val))
384 pm_debug_messages_on = !!val;
388 power_attr(pm_debug_messages);
391 * __pm_pr_dbg - Print a suspend debug message to the kernel log.
392 * @defer: Whether or not to use printk_deferred() to print the message.
393 * @fmt: Message format.
395 * The message will be emitted if enabled through the pm_debug_messages
398 void __pm_pr_dbg(bool defer, const char *fmt, ...)
400 struct va_format vaf;
403 if (!pm_debug_messages_on)
412 printk_deferred(KERN_DEBUG "PM: %pV", &vaf);
414 printk(KERN_DEBUG "PM: %pV", &vaf);
419 #else /* !CONFIG_PM_SLEEP_DEBUG */
420 static inline void pm_print_times_init(void) {}
421 #endif /* CONFIG_PM_SLEEP_DEBUG */
423 struct kobject *power_kobj;
426 * state - control system sleep states.
428 * show() returns available sleep state labels, which may be "mem", "standby",
429 * "freeze" and "disk" (hibernation). See Documentation/power/states.txt for a
430 * description of what they mean.
432 * store() accepts one of those strings, translates it into the proper
433 * enumerated value, and initiates a suspend transition.
435 static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
439 #ifdef CONFIG_SUSPEND
442 for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++)
444 s += sprintf(s,"%s ", pm_states[i]);
447 if (hibernation_available())
448 s += sprintf(s, "disk ");
450 /* convert the last space to a newline */
455 static suspend_state_t decode_state(const char *buf, size_t n)
457 #ifdef CONFIG_SUSPEND
458 suspend_state_t state;
463 p = memchr(buf, '\n', n);
464 len = p ? p - buf : n;
466 /* Check hibernation first. */
467 if (len == 4 && !strncmp(buf, "disk", len))
468 return PM_SUSPEND_MAX;
470 #ifdef CONFIG_SUSPEND
471 for (state = PM_SUSPEND_MIN; state < PM_SUSPEND_MAX; state++) {
472 const char *label = pm_states[state];
474 if (label && len == strlen(label) && !strncmp(buf, label, len))
479 return PM_SUSPEND_ON;
482 static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
483 const char *buf, size_t n)
485 suspend_state_t state;
488 error = pm_autosleep_lock();
492 if (pm_autosleep_state() > PM_SUSPEND_ON) {
497 state = decode_state(buf, n);
498 if (state < PM_SUSPEND_MAX) {
499 if (state == PM_SUSPEND_MEM)
500 state = mem_sleep_current;
502 error = pm_suspend(state);
503 } else if (state == PM_SUSPEND_MAX) {
510 pm_autosleep_unlock();
511 return error ? error : n;
516 #ifdef CONFIG_PM_SLEEP
518 * The 'wakeup_count' attribute, along with the functions defined in
519 * drivers/base/power/wakeup.c, provides a means by which wakeup events can be
520 * handled in a non-racy way.
522 * If a wakeup event occurs when the system is in a sleep state, it simply is
523 * woken up. In turn, if an event that would wake the system up from a sleep
524 * state occurs when it is undergoing a transition to that sleep state, the
525 * transition should be aborted. Moreover, if such an event occurs when the
526 * system is in the working state, an attempt to start a transition to the
527 * given sleep state should fail during certain period after the detection of
528 * the event. Using the 'state' attribute alone is not sufficient to satisfy
529 * these requirements, because a wakeup event may occur exactly when 'state'
530 * is being written to and may be delivered to user space right before it is
531 * frozen, so the event will remain only partially processed until the system is
532 * woken up by another event. In particular, it won't cause the transition to
533 * a sleep state to be aborted.
535 * This difficulty may be overcome if user space uses 'wakeup_count' before
536 * writing to 'state'. It first should read from 'wakeup_count' and store
537 * the read value. Then, after carrying out its own preparations for the system
538 * transition to a sleep state, it should write the stored value to
539 * 'wakeup_count'. If that fails, at least one wakeup event has occurred since
540 * 'wakeup_count' was read and 'state' should not be written to. Otherwise, it
541 * is allowed to write to 'state', but the transition will be aborted if there
542 * are any wakeup events detected after 'wakeup_count' was written to.
545 static ssize_t wakeup_count_show(struct kobject *kobj,
546 struct kobj_attribute *attr,
551 return pm_get_wakeup_count(&val, true) ?
552 sprintf(buf, "%u\n", val) : -EINTR;
555 static ssize_t wakeup_count_store(struct kobject *kobj,
556 struct kobj_attribute *attr,
557 const char *buf, size_t n)
562 error = pm_autosleep_lock();
566 if (pm_autosleep_state() > PM_SUSPEND_ON) {
572 if (sscanf(buf, "%u", &val) == 1) {
573 if (pm_save_wakeup_count(val))
576 pm_print_active_wakeup_sources();
580 pm_autosleep_unlock();
584 power_attr(wakeup_count);
586 #ifdef CONFIG_PM_AUTOSLEEP
587 static ssize_t autosleep_show(struct kobject *kobj,
588 struct kobj_attribute *attr,
591 suspend_state_t state = pm_autosleep_state();
593 if (state == PM_SUSPEND_ON)
594 return sprintf(buf, "off\n");
596 #ifdef CONFIG_SUSPEND
597 if (state < PM_SUSPEND_MAX)
598 return sprintf(buf, "%s\n", pm_states[state] ?
599 pm_states[state] : "error");
601 #ifdef CONFIG_HIBERNATION
602 return sprintf(buf, "disk\n");
604 return sprintf(buf, "error");
608 static ssize_t autosleep_store(struct kobject *kobj,
609 struct kobj_attribute *attr,
610 const char *buf, size_t n)
612 suspend_state_t state = decode_state(buf, n);
615 if (state == PM_SUSPEND_ON
616 && strcmp(buf, "off") && strcmp(buf, "off\n"))
619 if (state == PM_SUSPEND_MEM)
620 state = mem_sleep_current;
622 error = pm_autosleep_set_state(state);
623 return error ? error : n;
626 power_attr(autosleep);
627 #endif /* CONFIG_PM_AUTOSLEEP */
629 #ifdef CONFIG_PM_WAKELOCKS
630 static ssize_t wake_lock_show(struct kobject *kobj,
631 struct kobj_attribute *attr,
634 return pm_show_wakelocks(buf, true);
637 static ssize_t wake_lock_store(struct kobject *kobj,
638 struct kobj_attribute *attr,
639 const char *buf, size_t n)
641 int error = pm_wake_lock(buf);
642 return error ? error : n;
645 power_attr(wake_lock);
647 static ssize_t wake_unlock_show(struct kobject *kobj,
648 struct kobj_attribute *attr,
651 return pm_show_wakelocks(buf, false);
654 static ssize_t wake_unlock_store(struct kobject *kobj,
655 struct kobj_attribute *attr,
656 const char *buf, size_t n)
658 int error = pm_wake_unlock(buf);
659 return error ? error : n;
662 power_attr(wake_unlock);
664 #endif /* CONFIG_PM_WAKELOCKS */
665 #endif /* CONFIG_PM_SLEEP */
667 #ifdef CONFIG_PM_TRACE
668 int pm_trace_enabled;
670 static ssize_t pm_trace_show(struct kobject *kobj, struct kobj_attribute *attr,
673 return sprintf(buf, "%d\n", pm_trace_enabled);
677 pm_trace_store(struct kobject *kobj, struct kobj_attribute *attr,
678 const char *buf, size_t n)
682 if (sscanf(buf, "%d", &val) == 1) {
683 pm_trace_enabled = !!val;
684 if (pm_trace_enabled) {
685 pr_warn("PM: Enabling pm_trace changes system date and time during resume.\n"
686 "PM: Correct system time has to be restored manually after resume.\n");
693 power_attr(pm_trace);
695 static ssize_t pm_trace_dev_match_show(struct kobject *kobj,
696 struct kobj_attribute *attr,
699 return show_trace_dev_match(buf, PAGE_SIZE);
702 power_attr_ro(pm_trace_dev_match);
704 #endif /* CONFIG_PM_TRACE */
706 #ifdef CONFIG_FREEZER
707 static ssize_t pm_freeze_timeout_show(struct kobject *kobj,
708 struct kobj_attribute *attr, char *buf)
710 return sprintf(buf, "%u\n", freeze_timeout_msecs);
713 static ssize_t pm_freeze_timeout_store(struct kobject *kobj,
714 struct kobj_attribute *attr,
715 const char *buf, size_t n)
719 if (kstrtoul(buf, 10, &val))
722 freeze_timeout_msecs = val;
726 power_attr(pm_freeze_timeout);
728 #endif /* CONFIG_FREEZER*/
730 static struct attribute * g[] = {
732 #ifdef CONFIG_PM_TRACE
734 &pm_trace_dev_match_attr.attr,
736 #ifdef CONFIG_PM_SLEEP
738 &wakeup_count_attr.attr,
739 #ifdef CONFIG_SUSPEND
740 &mem_sleep_attr.attr,
742 #ifdef CONFIG_PM_AUTOSLEEP
743 &autosleep_attr.attr,
745 #ifdef CONFIG_PM_WAKELOCKS
746 &wake_lock_attr.attr,
747 &wake_unlock_attr.attr,
749 #ifdef CONFIG_PM_SLEEP_DEBUG
751 &pm_print_times_attr.attr,
752 &pm_wakeup_irq_attr.attr,
753 &pm_debug_messages_attr.attr,
756 #ifdef CONFIG_FREEZER
757 &pm_freeze_timeout_attr.attr,
762 static const struct attribute_group attr_group = {
766 struct workqueue_struct *pm_wq;
767 EXPORT_SYMBOL_GPL(pm_wq);
769 static int __init pm_start_workqueue(void)
771 pm_wq = alloc_workqueue("pm", WQ_FREEZABLE, 0);
773 return pm_wq ? 0 : -ENOMEM;
776 static int __init pm_init(void)
778 int error = pm_start_workqueue();
781 hibernate_image_size_init();
782 hibernate_reserved_size_init();
784 power_kobj = kobject_create_and_add("power", NULL);
787 error = sysfs_create_group(power_kobj, &attr_group);
790 pm_print_times_init();
791 return pm_autosleep_init();
794 core_initcall(pm_init);