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