Linux Audio

Check our new training course

Loading...
v6.2
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * kernel/power/main.c - PM subsystem core functionality.
  4 *
  5 * Copyright (c) 2003 Patrick Mochel
  6 * Copyright (c) 2003 Open Source Development Lab
 
 
 
  7 */
  8
  9#include <linux/export.h>
 10#include <linux/kobject.h>
 11#include <linux/string.h>
 12#include <linux/pm-trace.h>
 13#include <linux/workqueue.h>
 14#include <linux/debugfs.h>
 15#include <linux/seq_file.h>
 16#include <linux/suspend.h>
 17#include <linux/syscalls.h>
 18#include <linux/pm_runtime.h>
 19
 20#include "power.h"
 21
 22#ifdef CONFIG_PM_SLEEP
 23
 24unsigned int lock_system_sleep(void)
 25{
 26	unsigned int flags = current->flags;
 27	current->flags |= PF_NOFREEZE;
 28	mutex_lock(&system_transition_mutex);
 29	return flags;
 30}
 31EXPORT_SYMBOL_GPL(lock_system_sleep);
 32
 33void unlock_system_sleep(unsigned int flags)
 34{
 35	/*
 36	 * Don't use freezer_count() because we don't want the call to
 37	 * try_to_freeze() here.
 38	 *
 39	 * Reason:
 40	 * Fundamentally, we just don't need it, because freezing condition
 41	 * doesn't come into effect until we release the
 42	 * system_transition_mutex lock, since the freezer always works with
 43	 * system_transition_mutex held.
 44	 *
 45	 * More importantly, in the case of hibernation,
 46	 * unlock_system_sleep() gets called in snapshot_read() and
 47	 * snapshot_write() when the freezing condition is still in effect.
 48	 * Which means, if we use try_to_freeze() here, it would make them
 49	 * enter the refrigerator, thus causing hibernation to lockup.
 50	 */
 51	if (!(flags & PF_NOFREEZE))
 52		current->flags &= ~PF_NOFREEZE;
 53	mutex_unlock(&system_transition_mutex);
 54}
 55EXPORT_SYMBOL_GPL(unlock_system_sleep);
 56
 57void ksys_sync_helper(void)
 58{
 59	ktime_t start;
 60	long elapsed_msecs;
 61
 62	start = ktime_get();
 63	ksys_sync();
 64	elapsed_msecs = ktime_to_ms(ktime_sub(ktime_get(), start));
 65	pr_info("Filesystems sync: %ld.%03ld seconds\n",
 66		elapsed_msecs / MSEC_PER_SEC, elapsed_msecs % MSEC_PER_SEC);
 67}
 68EXPORT_SYMBOL_GPL(ksys_sync_helper);
 69
 70/* Routines for PM-transition notifications */
 71
 72static BLOCKING_NOTIFIER_HEAD(pm_chain_head);
 73
 74int register_pm_notifier(struct notifier_block *nb)
 75{
 76	return blocking_notifier_chain_register(&pm_chain_head, nb);
 77}
 78EXPORT_SYMBOL_GPL(register_pm_notifier);
 79
 80int unregister_pm_notifier(struct notifier_block *nb)
 81{
 82	return blocking_notifier_chain_unregister(&pm_chain_head, nb);
 83}
 84EXPORT_SYMBOL_GPL(unregister_pm_notifier);
 85
 86int pm_notifier_call_chain_robust(unsigned long val_up, unsigned long val_down)
 87{
 88	int ret;
 89
 90	ret = blocking_notifier_call_chain_robust(&pm_chain_head, val_up, val_down, NULL);
 91
 92	return notifier_to_errno(ret);
 93}
 94
 95int pm_notifier_call_chain(unsigned long val)
 96{
 97	return blocking_notifier_call_chain(&pm_chain_head, val, NULL);
 98}
 99
100/* If set, devices may be suspended and resumed asynchronously. */
101int pm_async_enabled = 1;
102
103static ssize_t pm_async_show(struct kobject *kobj, struct kobj_attribute *attr,
104			     char *buf)
105{
106	return sprintf(buf, "%d\n", pm_async_enabled);
107}
108
109static ssize_t pm_async_store(struct kobject *kobj, struct kobj_attribute *attr,
110			      const char *buf, size_t n)
111{
112	unsigned long val;
113
114	if (kstrtoul(buf, 10, &val))
115		return -EINVAL;
116
117	if (val > 1)
118		return -EINVAL;
119
120	pm_async_enabled = val;
121	return n;
122}
123
124power_attr(pm_async);
125
126#ifdef CONFIG_SUSPEND
127static ssize_t mem_sleep_show(struct kobject *kobj, struct kobj_attribute *attr,
128			      char *buf)
129{
130	char *s = buf;
131	suspend_state_t i;
132
133	for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++) {
134		if (i >= PM_SUSPEND_MEM && cxl_mem_active())
135			continue;
136		if (mem_sleep_states[i]) {
137			const char *label = mem_sleep_states[i];
138
139			if (mem_sleep_current == i)
140				s += sprintf(s, "[%s] ", label);
141			else
142				s += sprintf(s, "%s ", label);
143		}
144	}
145
146	/* Convert the last space to a newline if needed. */
147	if (s != buf)
148		*(s-1) = '\n';
149
150	return (s - buf);
151}
152
153static suspend_state_t decode_suspend_state(const char *buf, size_t n)
154{
155	suspend_state_t state;
156	char *p;
157	int len;
158
159	p = memchr(buf, '\n', n);
160	len = p ? p - buf : n;
161
162	for (state = PM_SUSPEND_MIN; state < PM_SUSPEND_MAX; state++) {
163		const char *label = mem_sleep_states[state];
164
165		if (label && len == strlen(label) && !strncmp(buf, label, len))
166			return state;
167	}
168
169	return PM_SUSPEND_ON;
170}
171
172static ssize_t mem_sleep_store(struct kobject *kobj, struct kobj_attribute *attr,
173			       const char *buf, size_t n)
174{
175	suspend_state_t state;
176	int error;
177
178	error = pm_autosleep_lock();
179	if (error)
180		return error;
181
182	if (pm_autosleep_state() > PM_SUSPEND_ON) {
183		error = -EBUSY;
184		goto out;
185	}
186
187	state = decode_suspend_state(buf, n);
188	if (state < PM_SUSPEND_MAX && state > PM_SUSPEND_ON)
189		mem_sleep_current = state;
190	else
191		error = -EINVAL;
192
193 out:
194	pm_autosleep_unlock();
195	return error ? error : n;
196}
197
198power_attr(mem_sleep);
199
200/*
201 * sync_on_suspend: invoke ksys_sync_helper() before suspend.
202 *
203 * show() returns whether ksys_sync_helper() is invoked before suspend.
204 * store() accepts 0 or 1.  0 disables ksys_sync_helper() and 1 enables it.
205 */
206bool sync_on_suspend_enabled = !IS_ENABLED(CONFIG_SUSPEND_SKIP_SYNC);
207
208static ssize_t sync_on_suspend_show(struct kobject *kobj,
209				   struct kobj_attribute *attr, char *buf)
210{
211	return sprintf(buf, "%d\n", sync_on_suspend_enabled);
212}
213
214static ssize_t sync_on_suspend_store(struct kobject *kobj,
215				    struct kobj_attribute *attr,
216				    const char *buf, size_t n)
217{
218	unsigned long val;
219
220	if (kstrtoul(buf, 10, &val))
221		return -EINVAL;
222
223	if (val > 1)
224		return -EINVAL;
225
226	sync_on_suspend_enabled = !!val;
227	return n;
228}
229
230power_attr(sync_on_suspend);
231#endif /* CONFIG_SUSPEND */
232
233#ifdef CONFIG_PM_SLEEP_DEBUG
234int pm_test_level = TEST_NONE;
235
236static const char * const pm_tests[__TEST_AFTER_LAST] = {
237	[TEST_NONE] = "none",
238	[TEST_CORE] = "core",
239	[TEST_CPUS] = "processors",
240	[TEST_PLATFORM] = "platform",
241	[TEST_DEVICES] = "devices",
242	[TEST_FREEZER] = "freezer",
243};
244
245static ssize_t pm_test_show(struct kobject *kobj, struct kobj_attribute *attr,
246				char *buf)
247{
248	char *s = buf;
249	int level;
250
251	for (level = TEST_FIRST; level <= TEST_MAX; level++)
252		if (pm_tests[level]) {
253			if (level == pm_test_level)
254				s += sprintf(s, "[%s] ", pm_tests[level]);
255			else
256				s += sprintf(s, "%s ", pm_tests[level]);
257		}
258
259	if (s != buf)
260		/* convert the last space to a newline */
261		*(s-1) = '\n';
262
263	return (s - buf);
264}
265
266static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
267				const char *buf, size_t n)
268{
269	unsigned int sleep_flags;
270	const char * const *s;
271	int error = -EINVAL;
272	int level;
273	char *p;
274	int len;
 
275
276	p = memchr(buf, '\n', n);
277	len = p ? p - buf : n;
278
279	sleep_flags = lock_system_sleep();
280
281	level = TEST_FIRST;
282	for (s = &pm_tests[level]; level <= TEST_MAX; s++, level++)
283		if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) {
284			pm_test_level = level;
285			error = 0;
286			break;
287		}
288
289	unlock_system_sleep(sleep_flags);
290
291	return error ? error : n;
292}
293
294power_attr(pm_test);
295#endif /* CONFIG_PM_SLEEP_DEBUG */
296
 
297static char *suspend_step_name(enum suspend_stat_step step)
298{
299	switch (step) {
300	case SUSPEND_FREEZE:
301		return "freeze";
302	case SUSPEND_PREPARE:
303		return "prepare";
304	case SUSPEND_SUSPEND:
305		return "suspend";
306	case SUSPEND_SUSPEND_NOIRQ:
307		return "suspend_noirq";
308	case SUSPEND_RESUME_NOIRQ:
309		return "resume_noirq";
310	case SUSPEND_RESUME:
311		return "resume";
312	default:
313		return "";
314	}
315}
316
317#define suspend_attr(_name)					\
318static ssize_t _name##_show(struct kobject *kobj,		\
319		struct kobj_attribute *attr, char *buf)		\
320{								\
321	return sprintf(buf, "%d\n", suspend_stats._name);	\
322}								\
323static struct kobj_attribute _name = __ATTR_RO(_name)
324
325suspend_attr(success);
326suspend_attr(fail);
327suspend_attr(failed_freeze);
328suspend_attr(failed_prepare);
329suspend_attr(failed_suspend);
330suspend_attr(failed_suspend_late);
331suspend_attr(failed_suspend_noirq);
332suspend_attr(failed_resume);
333suspend_attr(failed_resume_early);
334suspend_attr(failed_resume_noirq);
335
336static ssize_t last_failed_dev_show(struct kobject *kobj,
337		struct kobj_attribute *attr, char *buf)
338{
339	int index;
340	char *last_failed_dev = NULL;
341
342	index = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
343	index %= REC_FAILED_NUM;
344	last_failed_dev = suspend_stats.failed_devs[index];
345
346	return sprintf(buf, "%s\n", last_failed_dev);
347}
348static struct kobj_attribute last_failed_dev = __ATTR_RO(last_failed_dev);
349
350static ssize_t last_failed_errno_show(struct kobject *kobj,
351		struct kobj_attribute *attr, char *buf)
352{
353	int index;
354	int last_failed_errno;
355
356	index = suspend_stats.last_failed_errno + REC_FAILED_NUM - 1;
357	index %= REC_FAILED_NUM;
358	last_failed_errno = suspend_stats.errno[index];
359
360	return sprintf(buf, "%d\n", last_failed_errno);
361}
362static struct kobj_attribute last_failed_errno = __ATTR_RO(last_failed_errno);
363
364static ssize_t last_failed_step_show(struct kobject *kobj,
365		struct kobj_attribute *attr, char *buf)
366{
367	int index;
368	enum suspend_stat_step step;
369	char *last_failed_step = NULL;
370
371	index = suspend_stats.last_failed_step + REC_FAILED_NUM - 1;
372	index %= REC_FAILED_NUM;
373	step = suspend_stats.failed_steps[index];
374	last_failed_step = suspend_step_name(step);
375
376	return sprintf(buf, "%s\n", last_failed_step);
377}
378static struct kobj_attribute last_failed_step = __ATTR_RO(last_failed_step);
379
380static struct attribute *suspend_attrs[] = {
381	&success.attr,
382	&fail.attr,
383	&failed_freeze.attr,
384	&failed_prepare.attr,
385	&failed_suspend.attr,
386	&failed_suspend_late.attr,
387	&failed_suspend_noirq.attr,
388	&failed_resume.attr,
389	&failed_resume_early.attr,
390	&failed_resume_noirq.attr,
391	&last_failed_dev.attr,
392	&last_failed_errno.attr,
393	&last_failed_step.attr,
394	NULL,
395};
396
397static const struct attribute_group suspend_attr_group = {
398	.name = "suspend_stats",
399	.attrs = suspend_attrs,
400};
401
402#ifdef CONFIG_DEBUG_FS
403static int suspend_stats_show(struct seq_file *s, void *unused)
404{
405	int i, index, last_dev, last_errno, last_step;
406
407	last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
408	last_dev %= REC_FAILED_NUM;
409	last_errno = suspend_stats.last_failed_errno + REC_FAILED_NUM - 1;
410	last_errno %= REC_FAILED_NUM;
411	last_step = suspend_stats.last_failed_step + REC_FAILED_NUM - 1;
412	last_step %= REC_FAILED_NUM;
413	seq_printf(s, "%s: %d\n%s: %d\n%s: %d\n%s: %d\n%s: %d\n"
414			"%s: %d\n%s: %d\n%s: %d\n%s: %d\n%s: %d\n",
415			"success", suspend_stats.success,
416			"fail", suspend_stats.fail,
417			"failed_freeze", suspend_stats.failed_freeze,
418			"failed_prepare", suspend_stats.failed_prepare,
419			"failed_suspend", suspend_stats.failed_suspend,
420			"failed_suspend_late",
421				suspend_stats.failed_suspend_late,
422			"failed_suspend_noirq",
423				suspend_stats.failed_suspend_noirq,
424			"failed_resume", suspend_stats.failed_resume,
425			"failed_resume_early",
426				suspend_stats.failed_resume_early,
427			"failed_resume_noirq",
428				suspend_stats.failed_resume_noirq);
429	seq_printf(s,	"failures:\n  last_failed_dev:\t%-s\n",
430			suspend_stats.failed_devs[last_dev]);
431	for (i = 1; i < REC_FAILED_NUM; i++) {
432		index = last_dev + REC_FAILED_NUM - i;
433		index %= REC_FAILED_NUM;
434		seq_printf(s, "\t\t\t%-s\n",
435			suspend_stats.failed_devs[index]);
436	}
437	seq_printf(s,	"  last_failed_errno:\t%-d\n",
438			suspend_stats.errno[last_errno]);
439	for (i = 1; i < REC_FAILED_NUM; i++) {
440		index = last_errno + REC_FAILED_NUM - i;
441		index %= REC_FAILED_NUM;
442		seq_printf(s, "\t\t\t%-d\n",
443			suspend_stats.errno[index]);
444	}
445	seq_printf(s,	"  last_failed_step:\t%-s\n",
446			suspend_step_name(
447				suspend_stats.failed_steps[last_step]));
448	for (i = 1; i < REC_FAILED_NUM; i++) {
449		index = last_step + REC_FAILED_NUM - i;
450		index %= REC_FAILED_NUM;
451		seq_printf(s, "\t\t\t%-s\n",
452			suspend_step_name(
453				suspend_stats.failed_steps[index]));
454	}
455
456	return 0;
457}
458DEFINE_SHOW_ATTRIBUTE(suspend_stats);
 
 
 
 
 
 
 
 
 
 
 
459
460static int __init pm_debugfs_init(void)
461{
462	debugfs_create_file("suspend_stats", S_IFREG | S_IRUGO,
463			NULL, NULL, &suspend_stats_fops);
464	return 0;
465}
466
467late_initcall(pm_debugfs_init);
468#endif /* CONFIG_DEBUG_FS */
469
470#endif /* CONFIG_PM_SLEEP */
471
472#ifdef CONFIG_PM_SLEEP_DEBUG
473/*
474 * pm_print_times: print time taken by devices to suspend and resume.
475 *
476 * show() returns whether printing of suspend and resume times is enabled.
477 * store() accepts 0 or 1.  0 disables printing and 1 enables it.
478 */
479bool pm_print_times_enabled;
480
481static ssize_t pm_print_times_show(struct kobject *kobj,
482				   struct kobj_attribute *attr, char *buf)
483{
484	return sprintf(buf, "%d\n", pm_print_times_enabled);
485}
486
487static ssize_t pm_print_times_store(struct kobject *kobj,
488				    struct kobj_attribute *attr,
489				    const char *buf, size_t n)
490{
491	unsigned long val;
492
493	if (kstrtoul(buf, 10, &val))
494		return -EINVAL;
495
496	if (val > 1)
497		return -EINVAL;
498
499	pm_print_times_enabled = !!val;
500	return n;
501}
502
503power_attr(pm_print_times);
504
505static inline void pm_print_times_init(void)
506{
507	pm_print_times_enabled = !!initcall_debug;
508}
509
510static ssize_t pm_wakeup_irq_show(struct kobject *kobj,
511					struct kobj_attribute *attr,
512					char *buf)
513{
514	if (!pm_wakeup_irq())
515		return -ENODATA;
516
517	return sprintf(buf, "%u\n", pm_wakeup_irq());
518}
519
520power_attr_ro(pm_wakeup_irq);
521
522bool pm_debug_messages_on __read_mostly;
523
524static ssize_t pm_debug_messages_show(struct kobject *kobj,
525				      struct kobj_attribute *attr, char *buf)
526{
527	return sprintf(buf, "%d\n", pm_debug_messages_on);
528}
529
530static ssize_t pm_debug_messages_store(struct kobject *kobj,
531				       struct kobj_attribute *attr,
532				       const char *buf, size_t n)
533{
534	unsigned long val;
535
536	if (kstrtoul(buf, 10, &val))
537		return -EINVAL;
538
539	if (val > 1)
540		return -EINVAL;
541
542	pm_debug_messages_on = !!val;
543	return n;
544}
545
546power_attr(pm_debug_messages);
547
548static int __init pm_debug_messages_setup(char *str)
549{
550	pm_debug_messages_on = true;
551	return 1;
552}
553__setup("pm_debug_messages", pm_debug_messages_setup);
554
555#else /* !CONFIG_PM_SLEEP_DEBUG */
556static inline void pm_print_times_init(void) {}
557#endif /* CONFIG_PM_SLEEP_DEBUG */
558
559struct kobject *power_kobj;
560
561/*
562 * state - control system sleep states.
563 *
564 * show() returns available sleep state labels, which may be "mem", "standby",
565 * "freeze" and "disk" (hibernation).
566 * See Documentation/admin-guide/pm/sleep-states.rst for a description of
567 * what they mean.
568 *
569 * store() accepts one of those strings, translates it into the proper
570 * enumerated value, and initiates a suspend transition.
571 */
572static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
573			  char *buf)
574{
575	char *s = buf;
576#ifdef CONFIG_SUSPEND
577	suspend_state_t i;
578
579	for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++)
580		if (pm_states[i])
581			s += sprintf(s,"%s ", pm_states[i]);
582
583#endif
584	if (hibernation_available())
585		s += sprintf(s, "disk ");
 
586	if (s != buf)
587		/* convert the last space to a newline */
588		*(s-1) = '\n';
 
589	return (s - buf);
590}
591
592static suspend_state_t decode_state(const char *buf, size_t n)
593{
594#ifdef CONFIG_SUSPEND
595	suspend_state_t state;
 
596#endif
597	char *p;
598	int len;
599
600	p = memchr(buf, '\n', n);
601	len = p ? p - buf : n;
602
603	/* Check hibernation first. */
604	if (len == 4 && str_has_prefix(buf, "disk"))
605		return PM_SUSPEND_MAX;
606
607#ifdef CONFIG_SUSPEND
608	for (state = PM_SUSPEND_MIN; state < PM_SUSPEND_MAX; state++) {
609		const char *label = pm_states[state];
610
611		if (label && len == strlen(label) && !strncmp(buf, label, len))
612			return state;
613	}
614#endif
615
616	return PM_SUSPEND_ON;
617}
618
619static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
620			   const char *buf, size_t n)
621{
622	suspend_state_t state;
623	int error;
624
625	error = pm_autosleep_lock();
626	if (error)
627		return error;
628
629	if (pm_autosleep_state() > PM_SUSPEND_ON) {
630		error = -EBUSY;
631		goto out;
632	}
633
634	state = decode_state(buf, n);
635	if (state < PM_SUSPEND_MAX) {
636		if (state == PM_SUSPEND_MEM)
637			state = mem_sleep_current;
638
639		error = pm_suspend(state);
640	} else if (state == PM_SUSPEND_MAX) {
641		error = hibernate();
642	} else {
643		error = -EINVAL;
644	}
645
646 out:
647	pm_autosleep_unlock();
648	return error ? error : n;
649}
650
651power_attr(state);
652
653#ifdef CONFIG_PM_SLEEP
654/*
655 * The 'wakeup_count' attribute, along with the functions defined in
656 * drivers/base/power/wakeup.c, provides a means by which wakeup events can be
657 * handled in a non-racy way.
658 *
659 * If a wakeup event occurs when the system is in a sleep state, it simply is
660 * woken up.  In turn, if an event that would wake the system up from a sleep
661 * state occurs when it is undergoing a transition to that sleep state, the
662 * transition should be aborted.  Moreover, if such an event occurs when the
663 * system is in the working state, an attempt to start a transition to the
664 * given sleep state should fail during certain period after the detection of
665 * the event.  Using the 'state' attribute alone is not sufficient to satisfy
666 * these requirements, because a wakeup event may occur exactly when 'state'
667 * is being written to and may be delivered to user space right before it is
668 * frozen, so the event will remain only partially processed until the system is
669 * woken up by another event.  In particular, it won't cause the transition to
670 * a sleep state to be aborted.
671 *
672 * This difficulty may be overcome if user space uses 'wakeup_count' before
673 * writing to 'state'.  It first should read from 'wakeup_count' and store
674 * the read value.  Then, after carrying out its own preparations for the system
675 * transition to a sleep state, it should write the stored value to
676 * 'wakeup_count'.  If that fails, at least one wakeup event has occurred since
677 * 'wakeup_count' was read and 'state' should not be written to.  Otherwise, it
678 * is allowed to write to 'state', but the transition will be aborted if there
679 * are any wakeup events detected after 'wakeup_count' was written to.
680 */
681
682static ssize_t wakeup_count_show(struct kobject *kobj,
683				struct kobj_attribute *attr,
684				char *buf)
685{
686	unsigned int val;
687
688	return pm_get_wakeup_count(&val, true) ?
689		sprintf(buf, "%u\n", val) : -EINTR;
690}
691
692static ssize_t wakeup_count_store(struct kobject *kobj,
693				struct kobj_attribute *attr,
694				const char *buf, size_t n)
695{
696	unsigned int val;
697	int error;
698
699	error = pm_autosleep_lock();
700	if (error)
701		return error;
702
703	if (pm_autosleep_state() > PM_SUSPEND_ON) {
704		error = -EBUSY;
705		goto out;
706	}
707
708	error = -EINVAL;
709	if (sscanf(buf, "%u", &val) == 1) {
710		if (pm_save_wakeup_count(val))
711			error = n;
712		else
713			pm_print_active_wakeup_sources();
714	}
715
716 out:
717	pm_autosleep_unlock();
718	return error;
719}
720
721power_attr(wakeup_count);
722
723#ifdef CONFIG_PM_AUTOSLEEP
724static ssize_t autosleep_show(struct kobject *kobj,
725			      struct kobj_attribute *attr,
726			      char *buf)
727{
728	suspend_state_t state = pm_autosleep_state();
729
730	if (state == PM_SUSPEND_ON)
731		return sprintf(buf, "off\n");
732
733#ifdef CONFIG_SUSPEND
734	if (state < PM_SUSPEND_MAX)
735		return sprintf(buf, "%s\n", pm_states[state] ?
736					pm_states[state] : "error");
737#endif
738#ifdef CONFIG_HIBERNATION
739	return sprintf(buf, "disk\n");
740#else
741	return sprintf(buf, "error");
742#endif
743}
744
745static ssize_t autosleep_store(struct kobject *kobj,
746			       struct kobj_attribute *attr,
747			       const char *buf, size_t n)
748{
749	suspend_state_t state = decode_state(buf, n);
750	int error;
751
752	if (state == PM_SUSPEND_ON
753	    && strcmp(buf, "off") && strcmp(buf, "off\n"))
754		return -EINVAL;
755
756	if (state == PM_SUSPEND_MEM)
757		state = mem_sleep_current;
758
759	error = pm_autosleep_set_state(state);
760	return error ? error : n;
761}
762
763power_attr(autosleep);
764#endif /* CONFIG_PM_AUTOSLEEP */
765
766#ifdef CONFIG_PM_WAKELOCKS
767static ssize_t wake_lock_show(struct kobject *kobj,
768			      struct kobj_attribute *attr,
769			      char *buf)
770{
771	return pm_show_wakelocks(buf, true);
772}
773
774static ssize_t wake_lock_store(struct kobject *kobj,
775			       struct kobj_attribute *attr,
776			       const char *buf, size_t n)
777{
778	int error = pm_wake_lock(buf);
779	return error ? error : n;
780}
781
782power_attr(wake_lock);
783
784static ssize_t wake_unlock_show(struct kobject *kobj,
785				struct kobj_attribute *attr,
786				char *buf)
787{
788	return pm_show_wakelocks(buf, false);
789}
790
791static ssize_t wake_unlock_store(struct kobject *kobj,
792				 struct kobj_attribute *attr,
793				 const char *buf, size_t n)
794{
795	int error = pm_wake_unlock(buf);
796	return error ? error : n;
797}
798
799power_attr(wake_unlock);
800
801#endif /* CONFIG_PM_WAKELOCKS */
802#endif /* CONFIG_PM_SLEEP */
803
804#ifdef CONFIG_PM_TRACE
805int pm_trace_enabled;
806
807static ssize_t pm_trace_show(struct kobject *kobj, struct kobj_attribute *attr,
808			     char *buf)
809{
810	return sprintf(buf, "%d\n", pm_trace_enabled);
811}
812
813static ssize_t
814pm_trace_store(struct kobject *kobj, struct kobj_attribute *attr,
815	       const char *buf, size_t n)
816{
817	int val;
818
819	if (sscanf(buf, "%d", &val) == 1) {
820		pm_trace_enabled = !!val;
821		if (pm_trace_enabled) {
822			pr_warn("PM: Enabling pm_trace changes system date and time during resume.\n"
823				"PM: Correct system time has to be restored manually after resume.\n");
824		}
825		return n;
826	}
827	return -EINVAL;
828}
829
830power_attr(pm_trace);
831
832static ssize_t pm_trace_dev_match_show(struct kobject *kobj,
833				       struct kobj_attribute *attr,
834				       char *buf)
835{
836	return show_trace_dev_match(buf, PAGE_SIZE);
837}
838
839power_attr_ro(pm_trace_dev_match);
 
 
 
 
 
 
 
840
841#endif /* CONFIG_PM_TRACE */
842
843#ifdef CONFIG_FREEZER
844static ssize_t pm_freeze_timeout_show(struct kobject *kobj,
845				      struct kobj_attribute *attr, char *buf)
846{
847	return sprintf(buf, "%u\n", freeze_timeout_msecs);
848}
849
850static ssize_t pm_freeze_timeout_store(struct kobject *kobj,
851				       struct kobj_attribute *attr,
852				       const char *buf, size_t n)
853{
854	unsigned long val;
855
856	if (kstrtoul(buf, 10, &val))
857		return -EINVAL;
858
859	freeze_timeout_msecs = val;
860	return n;
861}
862
863power_attr(pm_freeze_timeout);
864
865#endif	/* CONFIG_FREEZER*/
866
867static struct attribute * g[] = {
868	&state_attr.attr,
869#ifdef CONFIG_PM_TRACE
870	&pm_trace_attr.attr,
871	&pm_trace_dev_match_attr.attr,
872#endif
873#ifdef CONFIG_PM_SLEEP
874	&pm_async_attr.attr,
875	&wakeup_count_attr.attr,
876#ifdef CONFIG_SUSPEND
877	&mem_sleep_attr.attr,
878	&sync_on_suspend_attr.attr,
879#endif
880#ifdef CONFIG_PM_AUTOSLEEP
881	&autosleep_attr.attr,
882#endif
883#ifdef CONFIG_PM_WAKELOCKS
884	&wake_lock_attr.attr,
885	&wake_unlock_attr.attr,
886#endif
887#ifdef CONFIG_PM_SLEEP_DEBUG
888	&pm_test_attr.attr,
 
 
889	&pm_print_times_attr.attr,
890	&pm_wakeup_irq_attr.attr,
891	&pm_debug_messages_attr.attr,
892#endif
893#endif
894#ifdef CONFIG_FREEZER
895	&pm_freeze_timeout_attr.attr,
896#endif
897	NULL,
898};
899
900static const struct attribute_group attr_group = {
901	.attrs = g,
902};
903
904static const struct attribute_group *attr_groups[] = {
905	&attr_group,
906#ifdef CONFIG_PM_SLEEP
907	&suspend_attr_group,
908#endif
909	NULL,
910};
911
912struct workqueue_struct *pm_wq;
913EXPORT_SYMBOL_GPL(pm_wq);
914
915static int __init pm_start_workqueue(void)
916{
917	pm_wq = alloc_workqueue("pm", WQ_FREEZABLE, 0);
918
919	return pm_wq ? 0 : -ENOMEM;
920}
 
 
 
921
922static int __init pm_init(void)
923{
924	int error = pm_start_workqueue();
925	if (error)
926		return error;
927	hibernate_image_size_init();
928	hibernate_reserved_size_init();
929	pm_states_init();
930	power_kobj = kobject_create_and_add("power", NULL);
931	if (!power_kobj)
932		return -ENOMEM;
933	error = sysfs_create_groups(power_kobj, attr_groups);
934	if (error)
935		return error;
936	pm_print_times_init();
937	return pm_autosleep_init();
938}
939
940core_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);