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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
98int pm_notifier_call_chain_robust(unsigned long val_up, unsigned long val_down)
99{
100 int ret;
101
102 ret = blocking_notifier_call_chain_robust(&pm_chain_head, val_up, val_down, NULL);
103
104 return notifier_to_errno(ret);
105}
106
107int pm_notifier_call_chain(unsigned long val)
108{
109 return blocking_notifier_call_chain(&pm_chain_head, val, NULL);
110}
111
112/* If set, devices may be suspended and resumed asynchronously. */
113int pm_async_enabled = 1;
114
115static ssize_t pm_async_show(struct kobject *kobj, struct kobj_attribute *attr,
116 char *buf)
117{
118 return sysfs_emit(buf, "%d\n", pm_async_enabled);
119}
120
121static ssize_t pm_async_store(struct kobject *kobj, struct kobj_attribute *attr,
122 const char *buf, size_t n)
123{
124 unsigned long val;
125
126 if (kstrtoul(buf, 10, &val))
127 return -EINVAL;
128
129 if (val > 1)
130 return -EINVAL;
131
132 pm_async_enabled = val;
133 return n;
134}
135
136power_attr(pm_async);
137
138#ifdef CONFIG_SUSPEND
139static ssize_t mem_sleep_show(struct kobject *kobj, struct kobj_attribute *attr,
140 char *buf)
141{
142 ssize_t count = 0;
143 suspend_state_t i;
144
145 for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++) {
146 if (i >= PM_SUSPEND_MEM && cxl_mem_active())
147 continue;
148 if (mem_sleep_states[i]) {
149 const char *label = mem_sleep_states[i];
150
151 if (mem_sleep_current == i)
152 count += sysfs_emit_at(buf, count, "[%s] ", label);
153 else
154 count += sysfs_emit_at(buf, count, "%s ", label);
155 }
156 }
157
158 /* Convert the last space to a newline if needed. */
159 if (count > 0)
160 buf[count - 1] = '\n';
161
162 return count;
163}
164
165static suspend_state_t decode_suspend_state(const char *buf, size_t n)
166{
167 suspend_state_t state;
168 char *p;
169 int len;
170
171 p = memchr(buf, '\n', n);
172 len = p ? p - buf : n;
173
174 for (state = PM_SUSPEND_MIN; state < PM_SUSPEND_MAX; state++) {
175 const char *label = mem_sleep_states[state];
176
177 if (label && len == strlen(label) && !strncmp(buf, label, len))
178 return state;
179 }
180
181 return PM_SUSPEND_ON;
182}
183
184static ssize_t mem_sleep_store(struct kobject *kobj, struct kobj_attribute *attr,
185 const char *buf, size_t n)
186{
187 suspend_state_t state;
188 int error;
189
190 error = pm_autosleep_lock();
191 if (error)
192 return error;
193
194 if (pm_autosleep_state() > PM_SUSPEND_ON) {
195 error = -EBUSY;
196 goto out;
197 }
198
199 state = decode_suspend_state(buf, n);
200 if (state < PM_SUSPEND_MAX && state > PM_SUSPEND_ON)
201 mem_sleep_current = state;
202 else
203 error = -EINVAL;
204
205 out:
206 pm_autosleep_unlock();
207 return error ? error : n;
208}
209
210power_attr(mem_sleep);
211
212/*
213 * sync_on_suspend: invoke ksys_sync_helper() before suspend.
214 *
215 * show() returns whether ksys_sync_helper() is invoked before suspend.
216 * store() accepts 0 or 1. 0 disables ksys_sync_helper() and 1 enables it.
217 */
218bool sync_on_suspend_enabled = !IS_ENABLED(CONFIG_SUSPEND_SKIP_SYNC);
219
220static ssize_t sync_on_suspend_show(struct kobject *kobj,
221 struct kobj_attribute *attr, char *buf)
222{
223 return sysfs_emit(buf, "%d\n", sync_on_suspend_enabled);
224}
225
226static ssize_t sync_on_suspend_store(struct kobject *kobj,
227 struct kobj_attribute *attr,
228 const char *buf, size_t n)
229{
230 unsigned long val;
231
232 if (kstrtoul(buf, 10, &val))
233 return -EINVAL;
234
235 if (val > 1)
236 return -EINVAL;
237
238 sync_on_suspend_enabled = !!val;
239 return n;
240}
241
242power_attr(sync_on_suspend);
243#endif /* CONFIG_SUSPEND */
244
245#ifdef CONFIG_PM_SLEEP_DEBUG
246int pm_test_level = TEST_NONE;
247
248static const char * const pm_tests[__TEST_AFTER_LAST] = {
249 [TEST_NONE] = "none",
250 [TEST_CORE] = "core",
251 [TEST_CPUS] = "processors",
252 [TEST_PLATFORM] = "platform",
253 [TEST_DEVICES] = "devices",
254 [TEST_FREEZER] = "freezer",
255};
256
257static ssize_t pm_test_show(struct kobject *kobj, struct kobj_attribute *attr,
258 char *buf)
259{
260 ssize_t count = 0;
261 int level;
262
263 for (level = TEST_FIRST; level <= TEST_MAX; level++)
264 if (pm_tests[level]) {
265 if (level == pm_test_level)
266 count += sysfs_emit_at(buf, count, "[%s] ", pm_tests[level]);
267 else
268 count += sysfs_emit_at(buf, count, "%s ", pm_tests[level]);
269 }
270
271 /* Convert the last space to a newline if needed. */
272 if (count > 0)
273 buf[count - 1] = '\n';
274
275 return count;
276}
277
278static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
279 const char *buf, size_t n)
280{
281 unsigned int sleep_flags;
282 const char * const *s;
283 int error = -EINVAL;
284 int level;
285 char *p;
286 int len;
287
288 p = memchr(buf, '\n', n);
289 len = p ? p - buf : n;
290
291 sleep_flags = lock_system_sleep();
292
293 level = TEST_FIRST;
294 for (s = &pm_tests[level]; level <= TEST_MAX; s++, level++)
295 if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) {
296 pm_test_level = level;
297 error = 0;
298 break;
299 }
300
301 unlock_system_sleep(sleep_flags);
302
303 return error ? error : n;
304}
305
306power_attr(pm_test);
307#endif /* CONFIG_PM_SLEEP_DEBUG */
308
309#define SUSPEND_NR_STEPS SUSPEND_RESUME
310#define REC_FAILED_NUM 2
311
312struct suspend_stats {
313 unsigned int step_failures[SUSPEND_NR_STEPS];
314 unsigned int success;
315 unsigned int fail;
316 int last_failed_dev;
317 char failed_devs[REC_FAILED_NUM][40];
318 int last_failed_errno;
319 int errno[REC_FAILED_NUM];
320 int last_failed_step;
321 u64 last_hw_sleep;
322 u64 total_hw_sleep;
323 u64 max_hw_sleep;
324 enum suspend_stat_step failed_steps[REC_FAILED_NUM];
325};
326
327static struct suspend_stats suspend_stats;
328static DEFINE_MUTEX(suspend_stats_lock);
329
330void dpm_save_failed_dev(const char *name)
331{
332 mutex_lock(&suspend_stats_lock);
333
334 strscpy(suspend_stats.failed_devs[suspend_stats.last_failed_dev],
335 name, sizeof(suspend_stats.failed_devs[0]));
336 suspend_stats.last_failed_dev++;
337 suspend_stats.last_failed_dev %= REC_FAILED_NUM;
338
339 mutex_unlock(&suspend_stats_lock);
340}
341
342void dpm_save_failed_step(enum suspend_stat_step step)
343{
344 suspend_stats.step_failures[step-1]++;
345 suspend_stats.failed_steps[suspend_stats.last_failed_step] = step;
346 suspend_stats.last_failed_step++;
347 suspend_stats.last_failed_step %= REC_FAILED_NUM;
348}
349
350void dpm_save_errno(int err)
351{
352 if (!err) {
353 suspend_stats.success++;
354 return;
355 }
356
357 suspend_stats.fail++;
358
359 suspend_stats.errno[suspend_stats.last_failed_errno] = err;
360 suspend_stats.last_failed_errno++;
361 suspend_stats.last_failed_errno %= REC_FAILED_NUM;
362}
363
364void pm_report_hw_sleep_time(u64 t)
365{
366 suspend_stats.last_hw_sleep = t;
367 suspend_stats.total_hw_sleep += t;
368}
369EXPORT_SYMBOL_GPL(pm_report_hw_sleep_time);
370
371void pm_report_max_hw_sleep(u64 t)
372{
373 suspend_stats.max_hw_sleep = t;
374}
375EXPORT_SYMBOL_GPL(pm_report_max_hw_sleep);
376
377static const char * const suspend_step_names[] = {
378 [SUSPEND_WORKING] = "",
379 [SUSPEND_FREEZE] = "freeze",
380 [SUSPEND_PREPARE] = "prepare",
381 [SUSPEND_SUSPEND] = "suspend",
382 [SUSPEND_SUSPEND_LATE] = "suspend_late",
383 [SUSPEND_SUSPEND_NOIRQ] = "suspend_noirq",
384 [SUSPEND_RESUME_NOIRQ] = "resume_noirq",
385 [SUSPEND_RESUME_EARLY] = "resume_early",
386 [SUSPEND_RESUME] = "resume",
387};
388
389#define suspend_attr(_name, format_str) \
390static ssize_t _name##_show(struct kobject *kobj, \
391 struct kobj_attribute *attr, char *buf) \
392{ \
393 return sysfs_emit(buf, format_str, suspend_stats._name);\
394} \
395static struct kobj_attribute _name = __ATTR_RO(_name)
396
397suspend_attr(success, "%u\n");
398suspend_attr(fail, "%u\n");
399suspend_attr(last_hw_sleep, "%llu\n");
400suspend_attr(total_hw_sleep, "%llu\n");
401suspend_attr(max_hw_sleep, "%llu\n");
402
403#define suspend_step_attr(_name, step) \
404static ssize_t _name##_show(struct kobject *kobj, \
405 struct kobj_attribute *attr, char *buf) \
406{ \
407 return sysfs_emit(buf, "%u\n", \
408 suspend_stats.step_failures[step-1]); \
409} \
410static struct kobj_attribute _name = __ATTR_RO(_name)
411
412suspend_step_attr(failed_freeze, SUSPEND_FREEZE);
413suspend_step_attr(failed_prepare, SUSPEND_PREPARE);
414suspend_step_attr(failed_suspend, SUSPEND_SUSPEND);
415suspend_step_attr(failed_suspend_late, SUSPEND_SUSPEND_LATE);
416suspend_step_attr(failed_suspend_noirq, SUSPEND_SUSPEND_NOIRQ);
417suspend_step_attr(failed_resume, SUSPEND_RESUME);
418suspend_step_attr(failed_resume_early, SUSPEND_RESUME_EARLY);
419suspend_step_attr(failed_resume_noirq, SUSPEND_RESUME_NOIRQ);
420
421static ssize_t last_failed_dev_show(struct kobject *kobj,
422 struct kobj_attribute *attr, char *buf)
423{
424 int index;
425 char *last_failed_dev = NULL;
426
427 index = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
428 index %= REC_FAILED_NUM;
429 last_failed_dev = suspend_stats.failed_devs[index];
430
431 return sysfs_emit(buf, "%s\n", last_failed_dev);
432}
433static struct kobj_attribute last_failed_dev = __ATTR_RO(last_failed_dev);
434
435static ssize_t last_failed_errno_show(struct kobject *kobj,
436 struct kobj_attribute *attr, char *buf)
437{
438 int index;
439 int last_failed_errno;
440
441 index = suspend_stats.last_failed_errno + REC_FAILED_NUM - 1;
442 index %= REC_FAILED_NUM;
443 last_failed_errno = suspend_stats.errno[index];
444
445 return sysfs_emit(buf, "%d\n", last_failed_errno);
446}
447static struct kobj_attribute last_failed_errno = __ATTR_RO(last_failed_errno);
448
449static ssize_t last_failed_step_show(struct kobject *kobj,
450 struct kobj_attribute *attr, char *buf)
451{
452 enum suspend_stat_step step;
453 int index;
454
455 index = suspend_stats.last_failed_step + REC_FAILED_NUM - 1;
456 index %= REC_FAILED_NUM;
457 step = suspend_stats.failed_steps[index];
458
459 return sysfs_emit(buf, "%s\n", suspend_step_names[step]);
460}
461static struct kobj_attribute last_failed_step = __ATTR_RO(last_failed_step);
462
463static struct attribute *suspend_attrs[] = {
464 &success.attr,
465 &fail.attr,
466 &failed_freeze.attr,
467 &failed_prepare.attr,
468 &failed_suspend.attr,
469 &failed_suspend_late.attr,
470 &failed_suspend_noirq.attr,
471 &failed_resume.attr,
472 &failed_resume_early.attr,
473 &failed_resume_noirq.attr,
474 &last_failed_dev.attr,
475 &last_failed_errno.attr,
476 &last_failed_step.attr,
477 &last_hw_sleep.attr,
478 &total_hw_sleep.attr,
479 &max_hw_sleep.attr,
480 NULL,
481};
482
483static umode_t suspend_attr_is_visible(struct kobject *kobj, struct attribute *attr, int idx)
484{
485 if (attr != &last_hw_sleep.attr &&
486 attr != &total_hw_sleep.attr &&
487 attr != &max_hw_sleep.attr)
488 return 0444;
489
490#ifdef CONFIG_ACPI
491 if (acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0)
492 return 0444;
493#endif
494 return 0;
495}
496
497static const struct attribute_group suspend_attr_group = {
498 .name = "suspend_stats",
499 .attrs = suspend_attrs,
500 .is_visible = suspend_attr_is_visible,
501};
502
503#ifdef CONFIG_DEBUG_FS
504static int suspend_stats_show(struct seq_file *s, void *unused)
505{
506 int i, index, last_dev, last_errno, last_step;
507 enum suspend_stat_step step;
508
509 last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
510 last_dev %= REC_FAILED_NUM;
511 last_errno = suspend_stats.last_failed_errno + REC_FAILED_NUM - 1;
512 last_errno %= REC_FAILED_NUM;
513 last_step = suspend_stats.last_failed_step + REC_FAILED_NUM - 1;
514 last_step %= REC_FAILED_NUM;
515
516 seq_printf(s, "success: %u\nfail: %u\n",
517 suspend_stats.success, suspend_stats.fail);
518
519 for (step = SUSPEND_FREEZE; step <= SUSPEND_NR_STEPS; step++)
520 seq_printf(s, "failed_%s: %u\n", suspend_step_names[step],
521 suspend_stats.step_failures[step-1]);
522
523 seq_printf(s, "failures:\n last_failed_dev:\t%-s\n",
524 suspend_stats.failed_devs[last_dev]);
525 for (i = 1; i < REC_FAILED_NUM; i++) {
526 index = last_dev + REC_FAILED_NUM - i;
527 index %= REC_FAILED_NUM;
528 seq_printf(s, "\t\t\t%-s\n", suspend_stats.failed_devs[index]);
529 }
530 seq_printf(s, " last_failed_errno:\t%-d\n",
531 suspend_stats.errno[last_errno]);
532 for (i = 1; i < REC_FAILED_NUM; i++) {
533 index = last_errno + REC_FAILED_NUM - i;
534 index %= REC_FAILED_NUM;
535 seq_printf(s, "\t\t\t%-d\n", suspend_stats.errno[index]);
536 }
537 seq_printf(s, " last_failed_step:\t%-s\n",
538 suspend_step_names[suspend_stats.failed_steps[last_step]]);
539 for (i = 1; i < REC_FAILED_NUM; i++) {
540 index = last_step + REC_FAILED_NUM - i;
541 index %= REC_FAILED_NUM;
542 seq_printf(s, "\t\t\t%-s\n",
543 suspend_step_names[suspend_stats.failed_steps[index]]);
544 }
545
546 return 0;
547}
548DEFINE_SHOW_ATTRIBUTE(suspend_stats);
549
550static int __init pm_debugfs_init(void)
551{
552 debugfs_create_file("suspend_stats", S_IFREG | S_IRUGO,
553 NULL, NULL, &suspend_stats_fops);
554 return 0;
555}
556
557late_initcall(pm_debugfs_init);
558#endif /* CONFIG_DEBUG_FS */
559
560#endif /* CONFIG_PM_SLEEP */
561
562#ifdef CONFIG_PM_SLEEP_DEBUG
563/*
564 * pm_print_times: print time taken by devices to suspend and resume.
565 *
566 * show() returns whether printing of suspend and resume times is enabled.
567 * store() accepts 0 or 1. 0 disables printing and 1 enables it.
568 */
569bool pm_print_times_enabled;
570
571static ssize_t pm_print_times_show(struct kobject *kobj,
572 struct kobj_attribute *attr, char *buf)
573{
574 return sysfs_emit(buf, "%d\n", pm_print_times_enabled);
575}
576
577static ssize_t pm_print_times_store(struct kobject *kobj,
578 struct kobj_attribute *attr,
579 const char *buf, size_t n)
580{
581 unsigned long val;
582
583 if (kstrtoul(buf, 10, &val))
584 return -EINVAL;
585
586 if (val > 1)
587 return -EINVAL;
588
589 pm_print_times_enabled = !!val;
590 return n;
591}
592
593power_attr(pm_print_times);
594
595static inline void pm_print_times_init(void)
596{
597 pm_print_times_enabled = !!initcall_debug;
598}
599
600static ssize_t pm_wakeup_irq_show(struct kobject *kobj,
601 struct kobj_attribute *attr,
602 char *buf)
603{
604 if (!pm_wakeup_irq())
605 return -ENODATA;
606
607 return sysfs_emit(buf, "%u\n", pm_wakeup_irq());
608}
609
610power_attr_ro(pm_wakeup_irq);
611
612bool pm_debug_messages_on __read_mostly;
613
614bool pm_debug_messages_should_print(void)
615{
616 return pm_debug_messages_on && pm_suspend_target_state != PM_SUSPEND_ON;
617}
618EXPORT_SYMBOL_GPL(pm_debug_messages_should_print);
619
620static ssize_t pm_debug_messages_show(struct kobject *kobj,
621 struct kobj_attribute *attr, char *buf)
622{
623 return sysfs_emit(buf, "%d\n", pm_debug_messages_on);
624}
625
626static ssize_t pm_debug_messages_store(struct kobject *kobj,
627 struct kobj_attribute *attr,
628 const char *buf, size_t n)
629{
630 unsigned long val;
631
632 if (kstrtoul(buf, 10, &val))
633 return -EINVAL;
634
635 if (val > 1)
636 return -EINVAL;
637
638 pm_debug_messages_on = !!val;
639 return n;
640}
641
642power_attr(pm_debug_messages);
643
644static int __init pm_debug_messages_setup(char *str)
645{
646 pm_debug_messages_on = true;
647 return 1;
648}
649__setup("pm_debug_messages", pm_debug_messages_setup);
650
651#else /* !CONFIG_PM_SLEEP_DEBUG */
652static inline void pm_print_times_init(void) {}
653#endif /* CONFIG_PM_SLEEP_DEBUG */
654
655struct kobject *power_kobj;
656
657/*
658 * state - control system sleep states.
659 *
660 * show() returns available sleep state labels, which may be "mem", "standby",
661 * "freeze" and "disk" (hibernation).
662 * See Documentation/admin-guide/pm/sleep-states.rst for a description of
663 * what they mean.
664 *
665 * store() accepts one of those strings, translates it into the proper
666 * enumerated value, and initiates a suspend transition.
667 */
668static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
669 char *buf)
670{
671 ssize_t count = 0;
672#ifdef CONFIG_SUSPEND
673 suspend_state_t i;
674
675 for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++)
676 if (pm_states[i])
677 count += sysfs_emit_at(buf, count, "%s ", pm_states[i]);
678
679#endif
680 if (hibernation_available())
681 count += sysfs_emit_at(buf, count, "disk ");
682
683 /* Convert the last space to a newline if needed. */
684 if (count > 0)
685 buf[count - 1] = '\n';
686
687 return count;
688}
689
690static suspend_state_t decode_state(const char *buf, size_t n)
691{
692#ifdef CONFIG_SUSPEND
693 suspend_state_t state;
694#endif
695 char *p;
696 int len;
697
698 p = memchr(buf, '\n', n);
699 len = p ? p - buf : n;
700
701 /* Check hibernation first. */
702 if (len == 4 && str_has_prefix(buf, "disk"))
703 return PM_SUSPEND_MAX;
704
705#ifdef CONFIG_SUSPEND
706 for (state = PM_SUSPEND_MIN; state < PM_SUSPEND_MAX; state++) {
707 const char *label = pm_states[state];
708
709 if (label && len == strlen(label) && !strncmp(buf, label, len))
710 return state;
711 }
712#endif
713
714 return PM_SUSPEND_ON;
715}
716
717static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
718 const char *buf, size_t n)
719{
720 suspend_state_t state;
721 int error;
722
723 error = pm_autosleep_lock();
724 if (error)
725 return error;
726
727 if (pm_autosleep_state() > PM_SUSPEND_ON) {
728 error = -EBUSY;
729 goto out;
730 }
731
732 state = decode_state(buf, n);
733 if (state < PM_SUSPEND_MAX) {
734 if (state == PM_SUSPEND_MEM)
735 state = mem_sleep_current;
736
737 error = pm_suspend(state);
738 } else if (state == PM_SUSPEND_MAX) {
739 error = hibernate();
740 } else {
741 error = -EINVAL;
742 }
743
744 out:
745 pm_autosleep_unlock();
746 return error ? error : n;
747}
748
749power_attr(state);
750
751#ifdef CONFIG_PM_SLEEP
752/*
753 * The 'wakeup_count' attribute, along with the functions defined in
754 * drivers/base/power/wakeup.c, provides a means by which wakeup events can be
755 * handled in a non-racy way.
756 *
757 * If a wakeup event occurs when the system is in a sleep state, it simply is
758 * woken up. In turn, if an event that would wake the system up from a sleep
759 * state occurs when it is undergoing a transition to that sleep state, the
760 * transition should be aborted. Moreover, if such an event occurs when the
761 * system is in the working state, an attempt to start a transition to the
762 * given sleep state should fail during certain period after the detection of
763 * the event. Using the 'state' attribute alone is not sufficient to satisfy
764 * these requirements, because a wakeup event may occur exactly when 'state'
765 * is being written to and may be delivered to user space right before it is
766 * frozen, so the event will remain only partially processed until the system is
767 * woken up by another event. In particular, it won't cause the transition to
768 * a sleep state to be aborted.
769 *
770 * This difficulty may be overcome if user space uses 'wakeup_count' before
771 * writing to 'state'. It first should read from 'wakeup_count' and store
772 * the read value. Then, after carrying out its own preparations for the system
773 * transition to a sleep state, it should write the stored value to
774 * 'wakeup_count'. If that fails, at least one wakeup event has occurred since
775 * 'wakeup_count' was read and 'state' should not be written to. Otherwise, it
776 * is allowed to write to 'state', but the transition will be aborted if there
777 * are any wakeup events detected after 'wakeup_count' was written to.
778 */
779
780static ssize_t wakeup_count_show(struct kobject *kobj,
781 struct kobj_attribute *attr,
782 char *buf)
783{
784 unsigned int val;
785
786 return pm_get_wakeup_count(&val, true) ?
787 sysfs_emit(buf, "%u\n", val) : -EINTR;
788}
789
790static ssize_t wakeup_count_store(struct kobject *kobj,
791 struct kobj_attribute *attr,
792 const char *buf, size_t n)
793{
794 unsigned int val;
795 int error;
796
797 error = pm_autosleep_lock();
798 if (error)
799 return error;
800
801 if (pm_autosleep_state() > PM_SUSPEND_ON) {
802 error = -EBUSY;
803 goto out;
804 }
805
806 error = -EINVAL;
807 if (sscanf(buf, "%u", &val) == 1) {
808 if (pm_save_wakeup_count(val))
809 error = n;
810 else
811 pm_print_active_wakeup_sources();
812 }
813
814 out:
815 pm_autosleep_unlock();
816 return error;
817}
818
819power_attr(wakeup_count);
820
821#ifdef CONFIG_PM_AUTOSLEEP
822static ssize_t autosleep_show(struct kobject *kobj,
823 struct kobj_attribute *attr,
824 char *buf)
825{
826 suspend_state_t state = pm_autosleep_state();
827
828 if (state == PM_SUSPEND_ON)
829 return sysfs_emit(buf, "off\n");
830
831#ifdef CONFIG_SUSPEND
832 if (state < PM_SUSPEND_MAX)
833 return sysfs_emit(buf, "%s\n", pm_states[state] ?
834 pm_states[state] : "error");
835#endif
836#ifdef CONFIG_HIBERNATION
837 return sysfs_emit(buf, "disk\n");
838#else
839 return sysfs_emit(buf, "error\n");
840#endif
841}
842
843static ssize_t autosleep_store(struct kobject *kobj,
844 struct kobj_attribute *attr,
845 const char *buf, size_t n)
846{
847 suspend_state_t state = decode_state(buf, n);
848 int error;
849
850 if (state == PM_SUSPEND_ON
851 && strcmp(buf, "off") && strcmp(buf, "off\n"))
852 return -EINVAL;
853
854 if (state == PM_SUSPEND_MEM)
855 state = mem_sleep_current;
856
857 error = pm_autosleep_set_state(state);
858 return error ? error : n;
859}
860
861power_attr(autosleep);
862#endif /* CONFIG_PM_AUTOSLEEP */
863
864#ifdef CONFIG_PM_WAKELOCKS
865static ssize_t wake_lock_show(struct kobject *kobj,
866 struct kobj_attribute *attr,
867 char *buf)
868{
869 return pm_show_wakelocks(buf, true);
870}
871
872static ssize_t wake_lock_store(struct kobject *kobj,
873 struct kobj_attribute *attr,
874 const char *buf, size_t n)
875{
876 int error = pm_wake_lock(buf);
877 return error ? error : n;
878}
879
880power_attr(wake_lock);
881
882static ssize_t wake_unlock_show(struct kobject *kobj,
883 struct kobj_attribute *attr,
884 char *buf)
885{
886 return pm_show_wakelocks(buf, false);
887}
888
889static ssize_t wake_unlock_store(struct kobject *kobj,
890 struct kobj_attribute *attr,
891 const char *buf, size_t n)
892{
893 int error = pm_wake_unlock(buf);
894 return error ? error : n;
895}
896
897power_attr(wake_unlock);
898
899#endif /* CONFIG_PM_WAKELOCKS */
900#endif /* CONFIG_PM_SLEEP */
901
902#ifdef CONFIG_PM_TRACE
903int pm_trace_enabled;
904
905static ssize_t pm_trace_show(struct kobject *kobj, struct kobj_attribute *attr,
906 char *buf)
907{
908 return sysfs_emit(buf, "%d\n", pm_trace_enabled);
909}
910
911static ssize_t
912pm_trace_store(struct kobject *kobj, struct kobj_attribute *attr,
913 const char *buf, size_t n)
914{
915 int val;
916
917 if (sscanf(buf, "%d", &val) == 1) {
918 pm_trace_enabled = !!val;
919 if (pm_trace_enabled) {
920 pr_warn("PM: Enabling pm_trace changes system date and time during resume.\n"
921 "PM: Correct system time has to be restored manually after resume.\n");
922 }
923 return n;
924 }
925 return -EINVAL;
926}
927
928power_attr(pm_trace);
929
930static ssize_t pm_trace_dev_match_show(struct kobject *kobj,
931 struct kobj_attribute *attr,
932 char *buf)
933{
934 return show_trace_dev_match(buf, PAGE_SIZE);
935}
936
937power_attr_ro(pm_trace_dev_match);
938
939#endif /* CONFIG_PM_TRACE */
940
941#ifdef CONFIG_FREEZER
942static ssize_t pm_freeze_timeout_show(struct kobject *kobj,
943 struct kobj_attribute *attr, char *buf)
944{
945 return sysfs_emit(buf, "%u\n", freeze_timeout_msecs);
946}
947
948static ssize_t pm_freeze_timeout_store(struct kobject *kobj,
949 struct kobj_attribute *attr,
950 const char *buf, size_t n)
951{
952 unsigned long val;
953
954 if (kstrtoul(buf, 10, &val))
955 return -EINVAL;
956
957 freeze_timeout_msecs = val;
958 return n;
959}
960
961power_attr(pm_freeze_timeout);
962
963#endif /* CONFIG_FREEZER*/
964
965static struct attribute * g[] = {
966 &state_attr.attr,
967#ifdef CONFIG_PM_TRACE
968 &pm_trace_attr.attr,
969 &pm_trace_dev_match_attr.attr,
970#endif
971#ifdef CONFIG_PM_SLEEP
972 &pm_async_attr.attr,
973 &wakeup_count_attr.attr,
974#ifdef CONFIG_SUSPEND
975 &mem_sleep_attr.attr,
976 &sync_on_suspend_attr.attr,
977#endif
978#ifdef CONFIG_PM_AUTOSLEEP
979 &autosleep_attr.attr,
980#endif
981#ifdef CONFIG_PM_WAKELOCKS
982 &wake_lock_attr.attr,
983 &wake_unlock_attr.attr,
984#endif
985#ifdef CONFIG_PM_SLEEP_DEBUG
986 &pm_test_attr.attr,
987 &pm_print_times_attr.attr,
988 &pm_wakeup_irq_attr.attr,
989 &pm_debug_messages_attr.attr,
990#endif
991#endif
992#ifdef CONFIG_FREEZER
993 &pm_freeze_timeout_attr.attr,
994#endif
995 NULL,
996};
997
998static const struct attribute_group attr_group = {
999 .attrs = g,
1000};
1001
1002static const struct attribute_group *attr_groups[] = {
1003 &attr_group,
1004#ifdef CONFIG_PM_SLEEP
1005 &suspend_attr_group,
1006#endif
1007 NULL,
1008};
1009
1010struct workqueue_struct *pm_wq;
1011EXPORT_SYMBOL_GPL(pm_wq);
1012
1013static int __init pm_start_workqueue(void)
1014{
1015 pm_wq = alloc_workqueue("pm", WQ_FREEZABLE, 0);
1016
1017 return pm_wq ? 0 : -ENOMEM;
1018}
1019
1020static int __init pm_init(void)
1021{
1022 int error = pm_start_workqueue();
1023 if (error)
1024 return error;
1025 hibernate_image_size_init();
1026 hibernate_reserved_size_init();
1027 pm_states_init();
1028 power_kobj = kobject_create_and_add("power", NULL);
1029 if (!power_kobj)
1030 return -ENOMEM;
1031 error = sysfs_create_groups(power_kobj, attr_groups);
1032 if (error)
1033 return error;
1034 pm_print_times_init();
1035 return pm_autosleep_init();
1036}
1037
1038core_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);