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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/acpi.h>
10#include <linux/export.h>
11#include <linux/kobject.h>
12#include <linux/string.h>
13#include <linux/pm-trace.h>
14#include <linux/workqueue.h>
15#include <linux/debugfs.h>
16#include <linux/seq_file.h>
17#include <linux/suspend.h>
18#include <linux/syscalls.h>
19#include <linux/pm_runtime.h>
20
21#include "power.h"
22
23#ifdef CONFIG_PM_SLEEP
24/*
25 * The following functions are used by the suspend/hibernate code to temporarily
26 * change gfp_allowed_mask in order to avoid using I/O during memory allocations
27 * while devices are suspended. To avoid races with the suspend/hibernate code,
28 * they should always be called with system_transition_mutex held
29 * (gfp_allowed_mask also should only be modified with system_transition_mutex
30 * held, unless the suspend/hibernate code is guaranteed not to run in parallel
31 * with that modification).
32 */
33static gfp_t saved_gfp_mask;
34
35void pm_restore_gfp_mask(void)
36{
37 WARN_ON(!mutex_is_locked(&system_transition_mutex));
38 if (saved_gfp_mask) {
39 gfp_allowed_mask = saved_gfp_mask;
40 saved_gfp_mask = 0;
41 }
42}
43
44void pm_restrict_gfp_mask(void)
45{
46 WARN_ON(!mutex_is_locked(&system_transition_mutex));
47 WARN_ON(saved_gfp_mask);
48 saved_gfp_mask = gfp_allowed_mask;
49 gfp_allowed_mask &= ~(__GFP_IO | __GFP_FS);
50}
51
52unsigned int lock_system_sleep(void)
53{
54 unsigned int flags = current->flags;
55 current->flags |= PF_NOFREEZE;
56 mutex_lock(&system_transition_mutex);
57 return flags;
58}
59EXPORT_SYMBOL_GPL(lock_system_sleep);
60
61void unlock_system_sleep(unsigned int flags)
62{
63 if (!(flags & PF_NOFREEZE))
64 current->flags &= ~PF_NOFREEZE;
65 mutex_unlock(&system_transition_mutex);
66}
67EXPORT_SYMBOL_GPL(unlock_system_sleep);
68
69void ksys_sync_helper(void)
70{
71 ktime_t start;
72 long elapsed_msecs;
73
74 start = ktime_get();
75 ksys_sync();
76 elapsed_msecs = ktime_to_ms(ktime_sub(ktime_get(), start));
77 pr_info("Filesystems sync: %ld.%03ld seconds\n",
78 elapsed_msecs / MSEC_PER_SEC, elapsed_msecs % MSEC_PER_SEC);
79}
80EXPORT_SYMBOL_GPL(ksys_sync_helper);
81
82/* Routines for PM-transition notifications */
83
84static BLOCKING_NOTIFIER_HEAD(pm_chain_head);
85
86int register_pm_notifier(struct notifier_block *nb)
87{
88 return blocking_notifier_chain_register(&pm_chain_head, nb);
89}
90EXPORT_SYMBOL_GPL(register_pm_notifier);
91
92int unregister_pm_notifier(struct notifier_block *nb)
93{
94 return blocking_notifier_chain_unregister(&pm_chain_head, nb);
95}
96EXPORT_SYMBOL_GPL(unregister_pm_notifier);
97
98void pm_report_hw_sleep_time(u64 t)
99{
100 suspend_stats.last_hw_sleep = t;
101 suspend_stats.total_hw_sleep += t;
102}
103EXPORT_SYMBOL_GPL(pm_report_hw_sleep_time);
104
105void pm_report_max_hw_sleep(u64 t)
106{
107 suspend_stats.max_hw_sleep = t;
108}
109EXPORT_SYMBOL_GPL(pm_report_max_hw_sleep);
110
111int pm_notifier_call_chain_robust(unsigned long val_up, unsigned long val_down)
112{
113 int ret;
114
115 ret = blocking_notifier_call_chain_robust(&pm_chain_head, val_up, val_down, NULL);
116
117 return notifier_to_errno(ret);
118}
119
120int pm_notifier_call_chain(unsigned long val)
121{
122 return blocking_notifier_call_chain(&pm_chain_head, val, NULL);
123}
124
125/* If set, devices may be suspended and resumed asynchronously. */
126int pm_async_enabled = 1;
127
128static ssize_t pm_async_show(struct kobject *kobj, struct kobj_attribute *attr,
129 char *buf)
130{
131 return sprintf(buf, "%d\n", pm_async_enabled);
132}
133
134static ssize_t pm_async_store(struct kobject *kobj, struct kobj_attribute *attr,
135 const char *buf, size_t n)
136{
137 unsigned long val;
138
139 if (kstrtoul(buf, 10, &val))
140 return -EINVAL;
141
142 if (val > 1)
143 return -EINVAL;
144
145 pm_async_enabled = val;
146 return n;
147}
148
149power_attr(pm_async);
150
151#ifdef CONFIG_SUSPEND
152static ssize_t mem_sleep_show(struct kobject *kobj, struct kobj_attribute *attr,
153 char *buf)
154{
155 char *s = buf;
156 suspend_state_t i;
157
158 for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++) {
159 if (i >= PM_SUSPEND_MEM && cxl_mem_active())
160 continue;
161 if (mem_sleep_states[i]) {
162 const char *label = mem_sleep_states[i];
163
164 if (mem_sleep_current == i)
165 s += sprintf(s, "[%s] ", label);
166 else
167 s += sprintf(s, "%s ", label);
168 }
169 }
170
171 /* Convert the last space to a newline if needed. */
172 if (s != buf)
173 *(s-1) = '\n';
174
175 return (s - buf);
176}
177
178static suspend_state_t decode_suspend_state(const char *buf, size_t n)
179{
180 suspend_state_t state;
181 char *p;
182 int len;
183
184 p = memchr(buf, '\n', n);
185 len = p ? p - buf : n;
186
187 for (state = PM_SUSPEND_MIN; state < PM_SUSPEND_MAX; state++) {
188 const char *label = mem_sleep_states[state];
189
190 if (label && len == strlen(label) && !strncmp(buf, label, len))
191 return state;
192 }
193
194 return PM_SUSPEND_ON;
195}
196
197static ssize_t mem_sleep_store(struct kobject *kobj, struct kobj_attribute *attr,
198 const char *buf, size_t n)
199{
200 suspend_state_t state;
201 int error;
202
203 error = pm_autosleep_lock();
204 if (error)
205 return error;
206
207 if (pm_autosleep_state() > PM_SUSPEND_ON) {
208 error = -EBUSY;
209 goto out;
210 }
211
212 state = decode_suspend_state(buf, n);
213 if (state < PM_SUSPEND_MAX && state > PM_SUSPEND_ON)
214 mem_sleep_current = state;
215 else
216 error = -EINVAL;
217
218 out:
219 pm_autosleep_unlock();
220 return error ? error : n;
221}
222
223power_attr(mem_sleep);
224
225/*
226 * sync_on_suspend: invoke ksys_sync_helper() before suspend.
227 *
228 * show() returns whether ksys_sync_helper() is invoked before suspend.
229 * store() accepts 0 or 1. 0 disables ksys_sync_helper() and 1 enables it.
230 */
231bool sync_on_suspend_enabled = !IS_ENABLED(CONFIG_SUSPEND_SKIP_SYNC);
232
233static ssize_t sync_on_suspend_show(struct kobject *kobj,
234 struct kobj_attribute *attr, char *buf)
235{
236 return sprintf(buf, "%d\n", sync_on_suspend_enabled);
237}
238
239static ssize_t sync_on_suspend_store(struct kobject *kobj,
240 struct kobj_attribute *attr,
241 const char *buf, size_t n)
242{
243 unsigned long val;
244
245 if (kstrtoul(buf, 10, &val))
246 return -EINVAL;
247
248 if (val > 1)
249 return -EINVAL;
250
251 sync_on_suspend_enabled = !!val;
252 return n;
253}
254
255power_attr(sync_on_suspend);
256#endif /* CONFIG_SUSPEND */
257
258#ifdef CONFIG_PM_SLEEP_DEBUG
259int pm_test_level = TEST_NONE;
260
261static const char * const pm_tests[__TEST_AFTER_LAST] = {
262 [TEST_NONE] = "none",
263 [TEST_CORE] = "core",
264 [TEST_CPUS] = "processors",
265 [TEST_PLATFORM] = "platform",
266 [TEST_DEVICES] = "devices",
267 [TEST_FREEZER] = "freezer",
268};
269
270static ssize_t pm_test_show(struct kobject *kobj, struct kobj_attribute *attr,
271 char *buf)
272{
273 char *s = buf;
274 int level;
275
276 for (level = TEST_FIRST; level <= TEST_MAX; level++)
277 if (pm_tests[level]) {
278 if (level == pm_test_level)
279 s += sprintf(s, "[%s] ", pm_tests[level]);
280 else
281 s += sprintf(s, "%s ", pm_tests[level]);
282 }
283
284 if (s != buf)
285 /* convert the last space to a newline */
286 *(s-1) = '\n';
287
288 return (s - buf);
289}
290
291static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
292 const char *buf, size_t n)
293{
294 unsigned int sleep_flags;
295 const char * const *s;
296 int error = -EINVAL;
297 int level;
298 char *p;
299 int len;
300
301 p = memchr(buf, '\n', n);
302 len = p ? p - buf : n;
303
304 sleep_flags = lock_system_sleep();
305
306 level = TEST_FIRST;
307 for (s = &pm_tests[level]; level <= TEST_MAX; s++, level++)
308 if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) {
309 pm_test_level = level;
310 error = 0;
311 break;
312 }
313
314 unlock_system_sleep(sleep_flags);
315
316 return error ? error : n;
317}
318
319power_attr(pm_test);
320#endif /* CONFIG_PM_SLEEP_DEBUG */
321
322static char *suspend_step_name(enum suspend_stat_step step)
323{
324 switch (step) {
325 case SUSPEND_FREEZE:
326 return "freeze";
327 case SUSPEND_PREPARE:
328 return "prepare";
329 case SUSPEND_SUSPEND:
330 return "suspend";
331 case SUSPEND_SUSPEND_NOIRQ:
332 return "suspend_noirq";
333 case SUSPEND_RESUME_NOIRQ:
334 return "resume_noirq";
335 case SUSPEND_RESUME:
336 return "resume";
337 default:
338 return "";
339 }
340}
341
342#define suspend_attr(_name, format_str) \
343static ssize_t _name##_show(struct kobject *kobj, \
344 struct kobj_attribute *attr, char *buf) \
345{ \
346 return sprintf(buf, format_str, suspend_stats._name); \
347} \
348static struct kobj_attribute _name = __ATTR_RO(_name)
349
350suspend_attr(success, "%d\n");
351suspend_attr(fail, "%d\n");
352suspend_attr(failed_freeze, "%d\n");
353suspend_attr(failed_prepare, "%d\n");
354suspend_attr(failed_suspend, "%d\n");
355suspend_attr(failed_suspend_late, "%d\n");
356suspend_attr(failed_suspend_noirq, "%d\n");
357suspend_attr(failed_resume, "%d\n");
358suspend_attr(failed_resume_early, "%d\n");
359suspend_attr(failed_resume_noirq, "%d\n");
360suspend_attr(last_hw_sleep, "%llu\n");
361suspend_attr(total_hw_sleep, "%llu\n");
362suspend_attr(max_hw_sleep, "%llu\n");
363
364static ssize_t last_failed_dev_show(struct kobject *kobj,
365 struct kobj_attribute *attr, char *buf)
366{
367 int index;
368 char *last_failed_dev = NULL;
369
370 index = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
371 index %= REC_FAILED_NUM;
372 last_failed_dev = suspend_stats.failed_devs[index];
373
374 return sprintf(buf, "%s\n", last_failed_dev);
375}
376static struct kobj_attribute last_failed_dev = __ATTR_RO(last_failed_dev);
377
378static ssize_t last_failed_errno_show(struct kobject *kobj,
379 struct kobj_attribute *attr, char *buf)
380{
381 int index;
382 int last_failed_errno;
383
384 index = suspend_stats.last_failed_errno + REC_FAILED_NUM - 1;
385 index %= REC_FAILED_NUM;
386 last_failed_errno = suspend_stats.errno[index];
387
388 return sprintf(buf, "%d\n", last_failed_errno);
389}
390static struct kobj_attribute last_failed_errno = __ATTR_RO(last_failed_errno);
391
392static ssize_t last_failed_step_show(struct kobject *kobj,
393 struct kobj_attribute *attr, char *buf)
394{
395 int index;
396 enum suspend_stat_step step;
397 char *last_failed_step = NULL;
398
399 index = suspend_stats.last_failed_step + REC_FAILED_NUM - 1;
400 index %= REC_FAILED_NUM;
401 step = suspend_stats.failed_steps[index];
402 last_failed_step = suspend_step_name(step);
403
404 return sprintf(buf, "%s\n", last_failed_step);
405}
406static struct kobj_attribute last_failed_step = __ATTR_RO(last_failed_step);
407
408static struct attribute *suspend_attrs[] = {
409 &success.attr,
410 &fail.attr,
411 &failed_freeze.attr,
412 &failed_prepare.attr,
413 &failed_suspend.attr,
414 &failed_suspend_late.attr,
415 &failed_suspend_noirq.attr,
416 &failed_resume.attr,
417 &failed_resume_early.attr,
418 &failed_resume_noirq.attr,
419 &last_failed_dev.attr,
420 &last_failed_errno.attr,
421 &last_failed_step.attr,
422 &last_hw_sleep.attr,
423 &total_hw_sleep.attr,
424 &max_hw_sleep.attr,
425 NULL,
426};
427
428static umode_t suspend_attr_is_visible(struct kobject *kobj, struct attribute *attr, int idx)
429{
430 if (attr != &last_hw_sleep.attr &&
431 attr != &total_hw_sleep.attr &&
432 attr != &max_hw_sleep.attr)
433 return 0444;
434
435#ifdef CONFIG_ACPI
436 if (acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0)
437 return 0444;
438#endif
439 return 0;
440}
441
442static const struct attribute_group suspend_attr_group = {
443 .name = "suspend_stats",
444 .attrs = suspend_attrs,
445 .is_visible = suspend_attr_is_visible,
446};
447
448#ifdef CONFIG_DEBUG_FS
449static int suspend_stats_show(struct seq_file *s, void *unused)
450{
451 int i, index, last_dev, last_errno, last_step;
452
453 last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
454 last_dev %= REC_FAILED_NUM;
455 last_errno = suspend_stats.last_failed_errno + REC_FAILED_NUM - 1;
456 last_errno %= REC_FAILED_NUM;
457 last_step = suspend_stats.last_failed_step + REC_FAILED_NUM - 1;
458 last_step %= REC_FAILED_NUM;
459 seq_printf(s, "%s: %d\n%s: %d\n%s: %d\n%s: %d\n%s: %d\n"
460 "%s: %d\n%s: %d\n%s: %d\n%s: %d\n%s: %d\n",
461 "success", suspend_stats.success,
462 "fail", suspend_stats.fail,
463 "failed_freeze", suspend_stats.failed_freeze,
464 "failed_prepare", suspend_stats.failed_prepare,
465 "failed_suspend", suspend_stats.failed_suspend,
466 "failed_suspend_late",
467 suspend_stats.failed_suspend_late,
468 "failed_suspend_noirq",
469 suspend_stats.failed_suspend_noirq,
470 "failed_resume", suspend_stats.failed_resume,
471 "failed_resume_early",
472 suspend_stats.failed_resume_early,
473 "failed_resume_noirq",
474 suspend_stats.failed_resume_noirq);
475 seq_printf(s, "failures:\n last_failed_dev:\t%-s\n",
476 suspend_stats.failed_devs[last_dev]);
477 for (i = 1; i < REC_FAILED_NUM; i++) {
478 index = last_dev + REC_FAILED_NUM - i;
479 index %= REC_FAILED_NUM;
480 seq_printf(s, "\t\t\t%-s\n",
481 suspend_stats.failed_devs[index]);
482 }
483 seq_printf(s, " last_failed_errno:\t%-d\n",
484 suspend_stats.errno[last_errno]);
485 for (i = 1; i < REC_FAILED_NUM; i++) {
486 index = last_errno + REC_FAILED_NUM - i;
487 index %= REC_FAILED_NUM;
488 seq_printf(s, "\t\t\t%-d\n",
489 suspend_stats.errno[index]);
490 }
491 seq_printf(s, " last_failed_step:\t%-s\n",
492 suspend_step_name(
493 suspend_stats.failed_steps[last_step]));
494 for (i = 1; i < REC_FAILED_NUM; i++) {
495 index = last_step + REC_FAILED_NUM - i;
496 index %= REC_FAILED_NUM;
497 seq_printf(s, "\t\t\t%-s\n",
498 suspend_step_name(
499 suspend_stats.failed_steps[index]));
500 }
501
502 return 0;
503}
504DEFINE_SHOW_ATTRIBUTE(suspend_stats);
505
506static int __init pm_debugfs_init(void)
507{
508 debugfs_create_file("suspend_stats", S_IFREG | S_IRUGO,
509 NULL, NULL, &suspend_stats_fops);
510 return 0;
511}
512
513late_initcall(pm_debugfs_init);
514#endif /* CONFIG_DEBUG_FS */
515
516#endif /* CONFIG_PM_SLEEP */
517
518#ifdef CONFIG_PM_SLEEP_DEBUG
519/*
520 * pm_print_times: print time taken by devices to suspend and resume.
521 *
522 * show() returns whether printing of suspend and resume times is enabled.
523 * store() accepts 0 or 1. 0 disables printing and 1 enables it.
524 */
525bool pm_print_times_enabled;
526
527static ssize_t pm_print_times_show(struct kobject *kobj,
528 struct kobj_attribute *attr, char *buf)
529{
530 return sprintf(buf, "%d\n", pm_print_times_enabled);
531}
532
533static ssize_t pm_print_times_store(struct kobject *kobj,
534 struct kobj_attribute *attr,
535 const char *buf, size_t n)
536{
537 unsigned long val;
538
539 if (kstrtoul(buf, 10, &val))
540 return -EINVAL;
541
542 if (val > 1)
543 return -EINVAL;
544
545 pm_print_times_enabled = !!val;
546 return n;
547}
548
549power_attr(pm_print_times);
550
551static inline void pm_print_times_init(void)
552{
553 pm_print_times_enabled = !!initcall_debug;
554}
555
556static ssize_t pm_wakeup_irq_show(struct kobject *kobj,
557 struct kobj_attribute *attr,
558 char *buf)
559{
560 if (!pm_wakeup_irq())
561 return -ENODATA;
562
563 return sprintf(buf, "%u\n", pm_wakeup_irq());
564}
565
566power_attr_ro(pm_wakeup_irq);
567
568bool pm_debug_messages_on __read_mostly;
569
570bool pm_debug_messages_should_print(void)
571{
572 return pm_debug_messages_on && pm_suspend_target_state != PM_SUSPEND_ON;
573}
574EXPORT_SYMBOL_GPL(pm_debug_messages_should_print);
575
576static ssize_t pm_debug_messages_show(struct kobject *kobj,
577 struct kobj_attribute *attr, char *buf)
578{
579 return sprintf(buf, "%d\n", pm_debug_messages_on);
580}
581
582static ssize_t pm_debug_messages_store(struct kobject *kobj,
583 struct kobj_attribute *attr,
584 const char *buf, size_t n)
585{
586 unsigned long val;
587
588 if (kstrtoul(buf, 10, &val))
589 return -EINVAL;
590
591 if (val > 1)
592 return -EINVAL;
593
594 pm_debug_messages_on = !!val;
595 return n;
596}
597
598power_attr(pm_debug_messages);
599
600static int __init pm_debug_messages_setup(char *str)
601{
602 pm_debug_messages_on = true;
603 return 1;
604}
605__setup("pm_debug_messages", pm_debug_messages_setup);
606
607#else /* !CONFIG_PM_SLEEP_DEBUG */
608static inline void pm_print_times_init(void) {}
609#endif /* CONFIG_PM_SLEEP_DEBUG */
610
611struct kobject *power_kobj;
612
613/*
614 * state - control system sleep states.
615 *
616 * show() returns available sleep state labels, which may be "mem", "standby",
617 * "freeze" and "disk" (hibernation).
618 * See Documentation/admin-guide/pm/sleep-states.rst for a description of
619 * what they mean.
620 *
621 * store() accepts one of those strings, translates it into the proper
622 * enumerated value, and initiates a suspend transition.
623 */
624static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
625 char *buf)
626{
627 char *s = buf;
628#ifdef CONFIG_SUSPEND
629 suspend_state_t i;
630
631 for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++)
632 if (pm_states[i])
633 s += sprintf(s,"%s ", pm_states[i]);
634
635#endif
636 if (hibernation_available())
637 s += sprintf(s, "disk ");
638 if (s != buf)
639 /* convert the last space to a newline */
640 *(s-1) = '\n';
641 return (s - buf);
642}
643
644static suspend_state_t decode_state(const char *buf, size_t n)
645{
646#ifdef CONFIG_SUSPEND
647 suspend_state_t state;
648#endif
649 char *p;
650 int len;
651
652 p = memchr(buf, '\n', n);
653 len = p ? p - buf : n;
654
655 /* Check hibernation first. */
656 if (len == 4 && str_has_prefix(buf, "disk"))
657 return PM_SUSPEND_MAX;
658
659#ifdef CONFIG_SUSPEND
660 for (state = PM_SUSPEND_MIN; state < PM_SUSPEND_MAX; state++) {
661 const char *label = pm_states[state];
662
663 if (label && len == strlen(label) && !strncmp(buf, label, len))
664 return state;
665 }
666#endif
667
668 return PM_SUSPEND_ON;
669}
670
671static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
672 const char *buf, size_t n)
673{
674 suspend_state_t state;
675 int error;
676
677 error = pm_autosleep_lock();
678 if (error)
679 return error;
680
681 if (pm_autosleep_state() > PM_SUSPEND_ON) {
682 error = -EBUSY;
683 goto out;
684 }
685
686 state = decode_state(buf, n);
687 if (state < PM_SUSPEND_MAX) {
688 if (state == PM_SUSPEND_MEM)
689 state = mem_sleep_current;
690
691 error = pm_suspend(state);
692 } else if (state == PM_SUSPEND_MAX) {
693 error = hibernate();
694 } else {
695 error = -EINVAL;
696 }
697
698 out:
699 pm_autosleep_unlock();
700 return error ? error : n;
701}
702
703power_attr(state);
704
705#ifdef CONFIG_PM_SLEEP
706/*
707 * The 'wakeup_count' attribute, along with the functions defined in
708 * drivers/base/power/wakeup.c, provides a means by which wakeup events can be
709 * handled in a non-racy way.
710 *
711 * If a wakeup event occurs when the system is in a sleep state, it simply is
712 * woken up. In turn, if an event that would wake the system up from a sleep
713 * state occurs when it is undergoing a transition to that sleep state, the
714 * transition should be aborted. Moreover, if such an event occurs when the
715 * system is in the working state, an attempt to start a transition to the
716 * given sleep state should fail during certain period after the detection of
717 * the event. Using the 'state' attribute alone is not sufficient to satisfy
718 * these requirements, because a wakeup event may occur exactly when 'state'
719 * is being written to and may be delivered to user space right before it is
720 * frozen, so the event will remain only partially processed until the system is
721 * woken up by another event. In particular, it won't cause the transition to
722 * a sleep state to be aborted.
723 *
724 * This difficulty may be overcome if user space uses 'wakeup_count' before
725 * writing to 'state'. It first should read from 'wakeup_count' and store
726 * the read value. Then, after carrying out its own preparations for the system
727 * transition to a sleep state, it should write the stored value to
728 * 'wakeup_count'. If that fails, at least one wakeup event has occurred since
729 * 'wakeup_count' was read and 'state' should not be written to. Otherwise, it
730 * is allowed to write to 'state', but the transition will be aborted if there
731 * are any wakeup events detected after 'wakeup_count' was written to.
732 */
733
734static ssize_t wakeup_count_show(struct kobject *kobj,
735 struct kobj_attribute *attr,
736 char *buf)
737{
738 unsigned int val;
739
740 return pm_get_wakeup_count(&val, true) ?
741 sprintf(buf, "%u\n", val) : -EINTR;
742}
743
744static ssize_t wakeup_count_store(struct kobject *kobj,
745 struct kobj_attribute *attr,
746 const char *buf, size_t n)
747{
748 unsigned int val;
749 int error;
750
751 error = pm_autosleep_lock();
752 if (error)
753 return error;
754
755 if (pm_autosleep_state() > PM_SUSPEND_ON) {
756 error = -EBUSY;
757 goto out;
758 }
759
760 error = -EINVAL;
761 if (sscanf(buf, "%u", &val) == 1) {
762 if (pm_save_wakeup_count(val))
763 error = n;
764 else
765 pm_print_active_wakeup_sources();
766 }
767
768 out:
769 pm_autosleep_unlock();
770 return error;
771}
772
773power_attr(wakeup_count);
774
775#ifdef CONFIG_PM_AUTOSLEEP
776static ssize_t autosleep_show(struct kobject *kobj,
777 struct kobj_attribute *attr,
778 char *buf)
779{
780 suspend_state_t state = pm_autosleep_state();
781
782 if (state == PM_SUSPEND_ON)
783 return sprintf(buf, "off\n");
784
785#ifdef CONFIG_SUSPEND
786 if (state < PM_SUSPEND_MAX)
787 return sprintf(buf, "%s\n", pm_states[state] ?
788 pm_states[state] : "error");
789#endif
790#ifdef CONFIG_HIBERNATION
791 return sprintf(buf, "disk\n");
792#else
793 return sprintf(buf, "error");
794#endif
795}
796
797static ssize_t autosleep_store(struct kobject *kobj,
798 struct kobj_attribute *attr,
799 const char *buf, size_t n)
800{
801 suspend_state_t state = decode_state(buf, n);
802 int error;
803
804 if (state == PM_SUSPEND_ON
805 && strcmp(buf, "off") && strcmp(buf, "off\n"))
806 return -EINVAL;
807
808 if (state == PM_SUSPEND_MEM)
809 state = mem_sleep_current;
810
811 error = pm_autosleep_set_state(state);
812 return error ? error : n;
813}
814
815power_attr(autosleep);
816#endif /* CONFIG_PM_AUTOSLEEP */
817
818#ifdef CONFIG_PM_WAKELOCKS
819static ssize_t wake_lock_show(struct kobject *kobj,
820 struct kobj_attribute *attr,
821 char *buf)
822{
823 return pm_show_wakelocks(buf, true);
824}
825
826static ssize_t wake_lock_store(struct kobject *kobj,
827 struct kobj_attribute *attr,
828 const char *buf, size_t n)
829{
830 int error = pm_wake_lock(buf);
831 return error ? error : n;
832}
833
834power_attr(wake_lock);
835
836static ssize_t wake_unlock_show(struct kobject *kobj,
837 struct kobj_attribute *attr,
838 char *buf)
839{
840 return pm_show_wakelocks(buf, false);
841}
842
843static ssize_t wake_unlock_store(struct kobject *kobj,
844 struct kobj_attribute *attr,
845 const char *buf, size_t n)
846{
847 int error = pm_wake_unlock(buf);
848 return error ? error : n;
849}
850
851power_attr(wake_unlock);
852
853#endif /* CONFIG_PM_WAKELOCKS */
854#endif /* CONFIG_PM_SLEEP */
855
856#ifdef CONFIG_PM_TRACE
857int pm_trace_enabled;
858
859static ssize_t pm_trace_show(struct kobject *kobj, struct kobj_attribute *attr,
860 char *buf)
861{
862 return sprintf(buf, "%d\n", pm_trace_enabled);
863}
864
865static ssize_t
866pm_trace_store(struct kobject *kobj, struct kobj_attribute *attr,
867 const char *buf, size_t n)
868{
869 int val;
870
871 if (sscanf(buf, "%d", &val) == 1) {
872 pm_trace_enabled = !!val;
873 if (pm_trace_enabled) {
874 pr_warn("PM: Enabling pm_trace changes system date and time during resume.\n"
875 "PM: Correct system time has to be restored manually after resume.\n");
876 }
877 return n;
878 }
879 return -EINVAL;
880}
881
882power_attr(pm_trace);
883
884static ssize_t pm_trace_dev_match_show(struct kobject *kobj,
885 struct kobj_attribute *attr,
886 char *buf)
887{
888 return show_trace_dev_match(buf, PAGE_SIZE);
889}
890
891power_attr_ro(pm_trace_dev_match);
892
893#endif /* CONFIG_PM_TRACE */
894
895#ifdef CONFIG_FREEZER
896static ssize_t pm_freeze_timeout_show(struct kobject *kobj,
897 struct kobj_attribute *attr, char *buf)
898{
899 return sprintf(buf, "%u\n", freeze_timeout_msecs);
900}
901
902static ssize_t pm_freeze_timeout_store(struct kobject *kobj,
903 struct kobj_attribute *attr,
904 const char *buf, size_t n)
905{
906 unsigned long val;
907
908 if (kstrtoul(buf, 10, &val))
909 return -EINVAL;
910
911 freeze_timeout_msecs = val;
912 return n;
913}
914
915power_attr(pm_freeze_timeout);
916
917#endif /* CONFIG_FREEZER*/
918
919static struct attribute * g[] = {
920 &state_attr.attr,
921#ifdef CONFIG_PM_TRACE
922 &pm_trace_attr.attr,
923 &pm_trace_dev_match_attr.attr,
924#endif
925#ifdef CONFIG_PM_SLEEP
926 &pm_async_attr.attr,
927 &wakeup_count_attr.attr,
928#ifdef CONFIG_SUSPEND
929 &mem_sleep_attr.attr,
930 &sync_on_suspend_attr.attr,
931#endif
932#ifdef CONFIG_PM_AUTOSLEEP
933 &autosleep_attr.attr,
934#endif
935#ifdef CONFIG_PM_WAKELOCKS
936 &wake_lock_attr.attr,
937 &wake_unlock_attr.attr,
938#endif
939#ifdef CONFIG_PM_SLEEP_DEBUG
940 &pm_test_attr.attr,
941 &pm_print_times_attr.attr,
942 &pm_wakeup_irq_attr.attr,
943 &pm_debug_messages_attr.attr,
944#endif
945#endif
946#ifdef CONFIG_FREEZER
947 &pm_freeze_timeout_attr.attr,
948#endif
949 NULL,
950};
951
952static const struct attribute_group attr_group = {
953 .attrs = g,
954};
955
956static const struct attribute_group *attr_groups[] = {
957 &attr_group,
958#ifdef CONFIG_PM_SLEEP
959 &suspend_attr_group,
960#endif
961 NULL,
962};
963
964struct workqueue_struct *pm_wq;
965EXPORT_SYMBOL_GPL(pm_wq);
966
967static int __init pm_start_workqueue(void)
968{
969 pm_wq = alloc_workqueue("pm", WQ_FREEZABLE, 0);
970
971 return pm_wq ? 0 : -ENOMEM;
972}
973
974static int __init pm_init(void)
975{
976 int error = pm_start_workqueue();
977 if (error)
978 return error;
979 hibernate_image_size_init();
980 hibernate_reserved_size_init();
981 pm_states_init();
982 power_kobj = kobject_create_and_add("power", NULL);
983 if (!power_kobj)
984 return -ENOMEM;
985 error = sysfs_create_groups(power_kobj, attr_groups);
986 if (error)
987 return error;
988 pm_print_times_init();
989 return pm_autosleep_init();
990}
991
992core_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_robust(unsigned long val_up, unsigned long val_down)
84{
85 int ret;
86
87 ret = blocking_notifier_call_chain_robust(&pm_chain_head, val_up, val_down, NULL);
88
89 return notifier_to_errno(ret);
90}
91
92int pm_notifier_call_chain(unsigned long val)
93{
94 return blocking_notifier_call_chain(&pm_chain_head, val, 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
194/*
195 * sync_on_suspend: invoke ksys_sync_helper() before suspend.
196 *
197 * show() returns whether ksys_sync_helper() is invoked before suspend.
198 * store() accepts 0 or 1. 0 disables ksys_sync_helper() and 1 enables it.
199 */
200bool sync_on_suspend_enabled = !IS_ENABLED(CONFIG_SUSPEND_SKIP_SYNC);
201
202static ssize_t sync_on_suspend_show(struct kobject *kobj,
203 struct kobj_attribute *attr, char *buf)
204{
205 return sprintf(buf, "%d\n", sync_on_suspend_enabled);
206}
207
208static ssize_t sync_on_suspend_store(struct kobject *kobj,
209 struct kobj_attribute *attr,
210 const char *buf, size_t n)
211{
212 unsigned long val;
213
214 if (kstrtoul(buf, 10, &val))
215 return -EINVAL;
216
217 if (val > 1)
218 return -EINVAL;
219
220 sync_on_suspend_enabled = !!val;
221 return n;
222}
223
224power_attr(sync_on_suspend);
225#endif /* CONFIG_SUSPEND */
226
227#ifdef CONFIG_PM_SLEEP_DEBUG
228int pm_test_level = TEST_NONE;
229
230static const char * const pm_tests[__TEST_AFTER_LAST] = {
231 [TEST_NONE] = "none",
232 [TEST_CORE] = "core",
233 [TEST_CPUS] = "processors",
234 [TEST_PLATFORM] = "platform",
235 [TEST_DEVICES] = "devices",
236 [TEST_FREEZER] = "freezer",
237};
238
239static ssize_t pm_test_show(struct kobject *kobj, struct kobj_attribute *attr,
240 char *buf)
241{
242 char *s = buf;
243 int level;
244
245 for (level = TEST_FIRST; level <= TEST_MAX; level++)
246 if (pm_tests[level]) {
247 if (level == pm_test_level)
248 s += sprintf(s, "[%s] ", pm_tests[level]);
249 else
250 s += sprintf(s, "%s ", pm_tests[level]);
251 }
252
253 if (s != buf)
254 /* convert the last space to a newline */
255 *(s-1) = '\n';
256
257 return (s - buf);
258}
259
260static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
261 const char *buf, size_t n)
262{
263 const char * const *s;
264 int level;
265 char *p;
266 int len;
267 int error = -EINVAL;
268
269 p = memchr(buf, '\n', n);
270 len = p ? p - buf : n;
271
272 lock_system_sleep();
273
274 level = TEST_FIRST;
275 for (s = &pm_tests[level]; level <= TEST_MAX; s++, level++)
276 if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) {
277 pm_test_level = level;
278 error = 0;
279 break;
280 }
281
282 unlock_system_sleep();
283
284 return error ? error : n;
285}
286
287power_attr(pm_test);
288#endif /* CONFIG_PM_SLEEP_DEBUG */
289
290static char *suspend_step_name(enum suspend_stat_step step)
291{
292 switch (step) {
293 case SUSPEND_FREEZE:
294 return "freeze";
295 case SUSPEND_PREPARE:
296 return "prepare";
297 case SUSPEND_SUSPEND:
298 return "suspend";
299 case SUSPEND_SUSPEND_NOIRQ:
300 return "suspend_noirq";
301 case SUSPEND_RESUME_NOIRQ:
302 return "resume_noirq";
303 case SUSPEND_RESUME:
304 return "resume";
305 default:
306 return "";
307 }
308}
309
310#define suspend_attr(_name) \
311static ssize_t _name##_show(struct kobject *kobj, \
312 struct kobj_attribute *attr, char *buf) \
313{ \
314 return sprintf(buf, "%d\n", suspend_stats._name); \
315} \
316static struct kobj_attribute _name = __ATTR_RO(_name)
317
318suspend_attr(success);
319suspend_attr(fail);
320suspend_attr(failed_freeze);
321suspend_attr(failed_prepare);
322suspend_attr(failed_suspend);
323suspend_attr(failed_suspend_late);
324suspend_attr(failed_suspend_noirq);
325suspend_attr(failed_resume);
326suspend_attr(failed_resume_early);
327suspend_attr(failed_resume_noirq);
328
329static ssize_t last_failed_dev_show(struct kobject *kobj,
330 struct kobj_attribute *attr, char *buf)
331{
332 int index;
333 char *last_failed_dev = NULL;
334
335 index = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
336 index %= REC_FAILED_NUM;
337 last_failed_dev = suspend_stats.failed_devs[index];
338
339 return sprintf(buf, "%s\n", last_failed_dev);
340}
341static struct kobj_attribute last_failed_dev = __ATTR_RO(last_failed_dev);
342
343static ssize_t last_failed_errno_show(struct kobject *kobj,
344 struct kobj_attribute *attr, char *buf)
345{
346 int index;
347 int last_failed_errno;
348
349 index = suspend_stats.last_failed_errno + REC_FAILED_NUM - 1;
350 index %= REC_FAILED_NUM;
351 last_failed_errno = suspend_stats.errno[index];
352
353 return sprintf(buf, "%d\n", last_failed_errno);
354}
355static struct kobj_attribute last_failed_errno = __ATTR_RO(last_failed_errno);
356
357static ssize_t last_failed_step_show(struct kobject *kobj,
358 struct kobj_attribute *attr, char *buf)
359{
360 int index;
361 enum suspend_stat_step step;
362 char *last_failed_step = NULL;
363
364 index = suspend_stats.last_failed_step + REC_FAILED_NUM - 1;
365 index %= REC_FAILED_NUM;
366 step = suspend_stats.failed_steps[index];
367 last_failed_step = suspend_step_name(step);
368
369 return sprintf(buf, "%s\n", last_failed_step);
370}
371static struct kobj_attribute last_failed_step = __ATTR_RO(last_failed_step);
372
373static struct attribute *suspend_attrs[] = {
374 &success.attr,
375 &fail.attr,
376 &failed_freeze.attr,
377 &failed_prepare.attr,
378 &failed_suspend.attr,
379 &failed_suspend_late.attr,
380 &failed_suspend_noirq.attr,
381 &failed_resume.attr,
382 &failed_resume_early.attr,
383 &failed_resume_noirq.attr,
384 &last_failed_dev.attr,
385 &last_failed_errno.attr,
386 &last_failed_step.attr,
387 NULL,
388};
389
390static const struct attribute_group suspend_attr_group = {
391 .name = "suspend_stats",
392 .attrs = suspend_attrs,
393};
394
395#ifdef CONFIG_DEBUG_FS
396static int suspend_stats_show(struct seq_file *s, void *unused)
397{
398 int i, index, last_dev, last_errno, last_step;
399
400 last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
401 last_dev %= REC_FAILED_NUM;
402 last_errno = suspend_stats.last_failed_errno + REC_FAILED_NUM - 1;
403 last_errno %= REC_FAILED_NUM;
404 last_step = suspend_stats.last_failed_step + REC_FAILED_NUM - 1;
405 last_step %= REC_FAILED_NUM;
406 seq_printf(s, "%s: %d\n%s: %d\n%s: %d\n%s: %d\n%s: %d\n"
407 "%s: %d\n%s: %d\n%s: %d\n%s: %d\n%s: %d\n",
408 "success", suspend_stats.success,
409 "fail", suspend_stats.fail,
410 "failed_freeze", suspend_stats.failed_freeze,
411 "failed_prepare", suspend_stats.failed_prepare,
412 "failed_suspend", suspend_stats.failed_suspend,
413 "failed_suspend_late",
414 suspend_stats.failed_suspend_late,
415 "failed_suspend_noirq",
416 suspend_stats.failed_suspend_noirq,
417 "failed_resume", suspend_stats.failed_resume,
418 "failed_resume_early",
419 suspend_stats.failed_resume_early,
420 "failed_resume_noirq",
421 suspend_stats.failed_resume_noirq);
422 seq_printf(s, "failures:\n last_failed_dev:\t%-s\n",
423 suspend_stats.failed_devs[last_dev]);
424 for (i = 1; i < REC_FAILED_NUM; i++) {
425 index = last_dev + REC_FAILED_NUM - i;
426 index %= REC_FAILED_NUM;
427 seq_printf(s, "\t\t\t%-s\n",
428 suspend_stats.failed_devs[index]);
429 }
430 seq_printf(s, " last_failed_errno:\t%-d\n",
431 suspend_stats.errno[last_errno]);
432 for (i = 1; i < REC_FAILED_NUM; i++) {
433 index = last_errno + REC_FAILED_NUM - i;
434 index %= REC_FAILED_NUM;
435 seq_printf(s, "\t\t\t%-d\n",
436 suspend_stats.errno[index]);
437 }
438 seq_printf(s, " last_failed_step:\t%-s\n",
439 suspend_step_name(
440 suspend_stats.failed_steps[last_step]));
441 for (i = 1; i < REC_FAILED_NUM; i++) {
442 index = last_step + REC_FAILED_NUM - i;
443 index %= REC_FAILED_NUM;
444 seq_printf(s, "\t\t\t%-s\n",
445 suspend_step_name(
446 suspend_stats.failed_steps[index]));
447 }
448
449 return 0;
450}
451DEFINE_SHOW_ATTRIBUTE(suspend_stats);
452
453static int __init pm_debugfs_init(void)
454{
455 debugfs_create_file("suspend_stats", S_IFREG | S_IRUGO,
456 NULL, NULL, &suspend_stats_fops);
457 return 0;
458}
459
460late_initcall(pm_debugfs_init);
461#endif /* CONFIG_DEBUG_FS */
462
463#endif /* CONFIG_PM_SLEEP */
464
465#ifdef CONFIG_PM_SLEEP_DEBUG
466/*
467 * pm_print_times: print time taken by devices to suspend and resume.
468 *
469 * show() returns whether printing of suspend and resume times is enabled.
470 * store() accepts 0 or 1. 0 disables printing and 1 enables it.
471 */
472bool pm_print_times_enabled;
473
474static ssize_t pm_print_times_show(struct kobject *kobj,
475 struct kobj_attribute *attr, char *buf)
476{
477 return sprintf(buf, "%d\n", pm_print_times_enabled);
478}
479
480static ssize_t pm_print_times_store(struct kobject *kobj,
481 struct kobj_attribute *attr,
482 const char *buf, size_t n)
483{
484 unsigned long val;
485
486 if (kstrtoul(buf, 10, &val))
487 return -EINVAL;
488
489 if (val > 1)
490 return -EINVAL;
491
492 pm_print_times_enabled = !!val;
493 return n;
494}
495
496power_attr(pm_print_times);
497
498static inline void pm_print_times_init(void)
499{
500 pm_print_times_enabled = !!initcall_debug;
501}
502
503static ssize_t pm_wakeup_irq_show(struct kobject *kobj,
504 struct kobj_attribute *attr,
505 char *buf)
506{
507 return pm_wakeup_irq ? sprintf(buf, "%u\n", pm_wakeup_irq) : -ENODATA;
508}
509
510power_attr_ro(pm_wakeup_irq);
511
512bool pm_debug_messages_on __read_mostly;
513
514static ssize_t pm_debug_messages_show(struct kobject *kobj,
515 struct kobj_attribute *attr, char *buf)
516{
517 return sprintf(buf, "%d\n", pm_debug_messages_on);
518}
519
520static ssize_t pm_debug_messages_store(struct kobject *kobj,
521 struct kobj_attribute *attr,
522 const char *buf, size_t n)
523{
524 unsigned long val;
525
526 if (kstrtoul(buf, 10, &val))
527 return -EINVAL;
528
529 if (val > 1)
530 return -EINVAL;
531
532 pm_debug_messages_on = !!val;
533 return n;
534}
535
536power_attr(pm_debug_messages);
537
538static int __init pm_debug_messages_setup(char *str)
539{
540 pm_debug_messages_on = true;
541 return 1;
542}
543__setup("pm_debug_messages", pm_debug_messages_setup);
544
545/**
546 * __pm_pr_dbg - Print a suspend debug message to the kernel log.
547 * @defer: Whether or not to use printk_deferred() to print the message.
548 * @fmt: Message format.
549 *
550 * The message will be emitted if enabled through the pm_debug_messages
551 * sysfs attribute.
552 */
553void __pm_pr_dbg(bool defer, const char *fmt, ...)
554{
555 struct va_format vaf;
556 va_list args;
557
558 if (!pm_debug_messages_on)
559 return;
560
561 va_start(args, fmt);
562
563 vaf.fmt = fmt;
564 vaf.va = &args;
565
566 if (defer)
567 printk_deferred(KERN_DEBUG "PM: %pV", &vaf);
568 else
569 printk(KERN_DEBUG "PM: %pV", &vaf);
570
571 va_end(args);
572}
573
574#else /* !CONFIG_PM_SLEEP_DEBUG */
575static inline void pm_print_times_init(void) {}
576#endif /* CONFIG_PM_SLEEP_DEBUG */
577
578struct kobject *power_kobj;
579
580/**
581 * state - control system sleep states.
582 *
583 * show() returns available sleep state labels, which may be "mem", "standby",
584 * "freeze" and "disk" (hibernation).
585 * See Documentation/admin-guide/pm/sleep-states.rst for a description of
586 * what they mean.
587 *
588 * store() accepts one of those strings, translates it into the proper
589 * enumerated value, and initiates a suspend transition.
590 */
591static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
592 char *buf)
593{
594 char *s = buf;
595#ifdef CONFIG_SUSPEND
596 suspend_state_t i;
597
598 for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++)
599 if (pm_states[i])
600 s += sprintf(s,"%s ", pm_states[i]);
601
602#endif
603 if (hibernation_available())
604 s += sprintf(s, "disk ");
605 if (s != buf)
606 /* convert the last space to a newline */
607 *(s-1) = '\n';
608 return (s - buf);
609}
610
611static suspend_state_t decode_state(const char *buf, size_t n)
612{
613#ifdef CONFIG_SUSPEND
614 suspend_state_t state;
615#endif
616 char *p;
617 int len;
618
619 p = memchr(buf, '\n', n);
620 len = p ? p - buf : n;
621
622 /* Check hibernation first. */
623 if (len == 4 && str_has_prefix(buf, "disk"))
624 return PM_SUSPEND_MAX;
625
626#ifdef CONFIG_SUSPEND
627 for (state = PM_SUSPEND_MIN; state < PM_SUSPEND_MAX; state++) {
628 const char *label = pm_states[state];
629
630 if (label && len == strlen(label) && !strncmp(buf, label, len))
631 return state;
632 }
633#endif
634
635 return PM_SUSPEND_ON;
636}
637
638static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
639 const char *buf, size_t n)
640{
641 suspend_state_t state;
642 int error;
643
644 error = pm_autosleep_lock();
645 if (error)
646 return error;
647
648 if (pm_autosleep_state() > PM_SUSPEND_ON) {
649 error = -EBUSY;
650 goto out;
651 }
652
653 state = decode_state(buf, n);
654 if (state < PM_SUSPEND_MAX) {
655 if (state == PM_SUSPEND_MEM)
656 state = mem_sleep_current;
657
658 error = pm_suspend(state);
659 } else if (state == PM_SUSPEND_MAX) {
660 error = hibernate();
661 } else {
662 error = -EINVAL;
663 }
664
665 out:
666 pm_autosleep_unlock();
667 return error ? error : n;
668}
669
670power_attr(state);
671
672#ifdef CONFIG_PM_SLEEP
673/*
674 * The 'wakeup_count' attribute, along with the functions defined in
675 * drivers/base/power/wakeup.c, provides a means by which wakeup events can be
676 * handled in a non-racy way.
677 *
678 * If a wakeup event occurs when the system is in a sleep state, it simply is
679 * woken up. In turn, if an event that would wake the system up from a sleep
680 * state occurs when it is undergoing a transition to that sleep state, the
681 * transition should be aborted. Moreover, if such an event occurs when the
682 * system is in the working state, an attempt to start a transition to the
683 * given sleep state should fail during certain period after the detection of
684 * the event. Using the 'state' attribute alone is not sufficient to satisfy
685 * these requirements, because a wakeup event may occur exactly when 'state'
686 * is being written to and may be delivered to user space right before it is
687 * frozen, so the event will remain only partially processed until the system is
688 * woken up by another event. In particular, it won't cause the transition to
689 * a sleep state to be aborted.
690 *
691 * This difficulty may be overcome if user space uses 'wakeup_count' before
692 * writing to 'state'. It first should read from 'wakeup_count' and store
693 * the read value. Then, after carrying out its own preparations for the system
694 * transition to a sleep state, it should write the stored value to
695 * 'wakeup_count'. If that fails, at least one wakeup event has occurred since
696 * 'wakeup_count' was read and 'state' should not be written to. Otherwise, it
697 * is allowed to write to 'state', but the transition will be aborted if there
698 * are any wakeup events detected after 'wakeup_count' was written to.
699 */
700
701static ssize_t wakeup_count_show(struct kobject *kobj,
702 struct kobj_attribute *attr,
703 char *buf)
704{
705 unsigned int val;
706
707 return pm_get_wakeup_count(&val, true) ?
708 sprintf(buf, "%u\n", val) : -EINTR;
709}
710
711static ssize_t wakeup_count_store(struct kobject *kobj,
712 struct kobj_attribute *attr,
713 const char *buf, size_t n)
714{
715 unsigned int val;
716 int error;
717
718 error = pm_autosleep_lock();
719 if (error)
720 return error;
721
722 if (pm_autosleep_state() > PM_SUSPEND_ON) {
723 error = -EBUSY;
724 goto out;
725 }
726
727 error = -EINVAL;
728 if (sscanf(buf, "%u", &val) == 1) {
729 if (pm_save_wakeup_count(val))
730 error = n;
731 else
732 pm_print_active_wakeup_sources();
733 }
734
735 out:
736 pm_autosleep_unlock();
737 return error;
738}
739
740power_attr(wakeup_count);
741
742#ifdef CONFIG_PM_AUTOSLEEP
743static ssize_t autosleep_show(struct kobject *kobj,
744 struct kobj_attribute *attr,
745 char *buf)
746{
747 suspend_state_t state = pm_autosleep_state();
748
749 if (state == PM_SUSPEND_ON)
750 return sprintf(buf, "off\n");
751
752#ifdef CONFIG_SUSPEND
753 if (state < PM_SUSPEND_MAX)
754 return sprintf(buf, "%s\n", pm_states[state] ?
755 pm_states[state] : "error");
756#endif
757#ifdef CONFIG_HIBERNATION
758 return sprintf(buf, "disk\n");
759#else
760 return sprintf(buf, "error");
761#endif
762}
763
764static ssize_t autosleep_store(struct kobject *kobj,
765 struct kobj_attribute *attr,
766 const char *buf, size_t n)
767{
768 suspend_state_t state = decode_state(buf, n);
769 int error;
770
771 if (state == PM_SUSPEND_ON
772 && strcmp(buf, "off") && strcmp(buf, "off\n"))
773 return -EINVAL;
774
775 if (state == PM_SUSPEND_MEM)
776 state = mem_sleep_current;
777
778 error = pm_autosleep_set_state(state);
779 return error ? error : n;
780}
781
782power_attr(autosleep);
783#endif /* CONFIG_PM_AUTOSLEEP */
784
785#ifdef CONFIG_PM_WAKELOCKS
786static ssize_t wake_lock_show(struct kobject *kobj,
787 struct kobj_attribute *attr,
788 char *buf)
789{
790 return pm_show_wakelocks(buf, true);
791}
792
793static ssize_t wake_lock_store(struct kobject *kobj,
794 struct kobj_attribute *attr,
795 const char *buf, size_t n)
796{
797 int error = pm_wake_lock(buf);
798 return error ? error : n;
799}
800
801power_attr(wake_lock);
802
803static ssize_t wake_unlock_show(struct kobject *kobj,
804 struct kobj_attribute *attr,
805 char *buf)
806{
807 return pm_show_wakelocks(buf, false);
808}
809
810static ssize_t wake_unlock_store(struct kobject *kobj,
811 struct kobj_attribute *attr,
812 const char *buf, size_t n)
813{
814 int error = pm_wake_unlock(buf);
815 return error ? error : n;
816}
817
818power_attr(wake_unlock);
819
820#endif /* CONFIG_PM_WAKELOCKS */
821#endif /* CONFIG_PM_SLEEP */
822
823#ifdef CONFIG_PM_TRACE
824int pm_trace_enabled;
825
826static ssize_t pm_trace_show(struct kobject *kobj, struct kobj_attribute *attr,
827 char *buf)
828{
829 return sprintf(buf, "%d\n", pm_trace_enabled);
830}
831
832static ssize_t
833pm_trace_store(struct kobject *kobj, struct kobj_attribute *attr,
834 const char *buf, size_t n)
835{
836 int val;
837
838 if (sscanf(buf, "%d", &val) == 1) {
839 pm_trace_enabled = !!val;
840 if (pm_trace_enabled) {
841 pr_warn("PM: Enabling pm_trace changes system date and time during resume.\n"
842 "PM: Correct system time has to be restored manually after resume.\n");
843 }
844 return n;
845 }
846 return -EINVAL;
847}
848
849power_attr(pm_trace);
850
851static ssize_t pm_trace_dev_match_show(struct kobject *kobj,
852 struct kobj_attribute *attr,
853 char *buf)
854{
855 return show_trace_dev_match(buf, PAGE_SIZE);
856}
857
858power_attr_ro(pm_trace_dev_match);
859
860#endif /* CONFIG_PM_TRACE */
861
862#ifdef CONFIG_FREEZER
863static ssize_t pm_freeze_timeout_show(struct kobject *kobj,
864 struct kobj_attribute *attr, char *buf)
865{
866 return sprintf(buf, "%u\n", freeze_timeout_msecs);
867}
868
869static ssize_t pm_freeze_timeout_store(struct kobject *kobj,
870 struct kobj_attribute *attr,
871 const char *buf, size_t n)
872{
873 unsigned long val;
874
875 if (kstrtoul(buf, 10, &val))
876 return -EINVAL;
877
878 freeze_timeout_msecs = val;
879 return n;
880}
881
882power_attr(pm_freeze_timeout);
883
884#endif /* CONFIG_FREEZER*/
885
886static struct attribute * g[] = {
887 &state_attr.attr,
888#ifdef CONFIG_PM_TRACE
889 &pm_trace_attr.attr,
890 &pm_trace_dev_match_attr.attr,
891#endif
892#ifdef CONFIG_PM_SLEEP
893 &pm_async_attr.attr,
894 &wakeup_count_attr.attr,
895#ifdef CONFIG_SUSPEND
896 &mem_sleep_attr.attr,
897 &sync_on_suspend_attr.attr,
898#endif
899#ifdef CONFIG_PM_AUTOSLEEP
900 &autosleep_attr.attr,
901#endif
902#ifdef CONFIG_PM_WAKELOCKS
903 &wake_lock_attr.attr,
904 &wake_unlock_attr.attr,
905#endif
906#ifdef CONFIG_PM_SLEEP_DEBUG
907 &pm_test_attr.attr,
908 &pm_print_times_attr.attr,
909 &pm_wakeup_irq_attr.attr,
910 &pm_debug_messages_attr.attr,
911#endif
912#endif
913#ifdef CONFIG_FREEZER
914 &pm_freeze_timeout_attr.attr,
915#endif
916 NULL,
917};
918
919static const struct attribute_group attr_group = {
920 .attrs = g,
921};
922
923static const struct attribute_group *attr_groups[] = {
924 &attr_group,
925#ifdef CONFIG_PM_SLEEP
926 &suspend_attr_group,
927#endif
928 NULL,
929};
930
931struct workqueue_struct *pm_wq;
932EXPORT_SYMBOL_GPL(pm_wq);
933
934static int __init pm_start_workqueue(void)
935{
936 pm_wq = alloc_workqueue("pm", WQ_FREEZABLE, 0);
937
938 return pm_wq ? 0 : -ENOMEM;
939}
940
941static int __init pm_init(void)
942{
943 int error = pm_start_workqueue();
944 if (error)
945 return error;
946 hibernate_image_size_init();
947 hibernate_reserved_size_init();
948 pm_states_init();
949 power_kobj = kobject_create_and_add("power", NULL);
950 if (!power_kobj)
951 return -ENOMEM;
952 error = sysfs_create_groups(power_kobj, attr_groups);
953 if (error)
954 return error;
955 pm_print_times_init();
956 return pm_autosleep_init();
957}
958
959core_initcall(pm_init);