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1/*
2 * kernel/power/main.c - PM subsystem core functionality.
3 *
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Open Source Development Lab
6 *
7 * This file is released under the GPLv2
8 *
9 */
10
11#include <linux/export.h>
12#include <linux/kobject.h>
13#include <linux/string.h>
14#include <linux/pm-trace.h>
15#include <linux/workqueue.h>
16#include <linux/debugfs.h>
17#include <linux/seq_file.h>
18
19#include "power.h"
20
21DEFINE_MUTEX(pm_mutex);
22
23#ifdef CONFIG_PM_SLEEP
24
25void lock_system_sleep(void)
26{
27 current->flags |= PF_FREEZER_SKIP;
28 mutex_lock(&pm_mutex);
29}
30EXPORT_SYMBOL_GPL(lock_system_sleep);
31
32void unlock_system_sleep(void)
33{
34 /*
35 * Don't use freezer_count() because we don't want the call to
36 * try_to_freeze() here.
37 *
38 * Reason:
39 * Fundamentally, we just don't need it, because freezing condition
40 * doesn't come into effect until we release the pm_mutex lock,
41 * since the freezer always works with pm_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(&pm_mutex);
51}
52EXPORT_SYMBOL_GPL(unlock_system_sleep);
53
54/* Routines for PM-transition notifications */
55
56static BLOCKING_NOTIFIER_HEAD(pm_chain_head);
57
58int register_pm_notifier(struct notifier_block *nb)
59{
60 return blocking_notifier_chain_register(&pm_chain_head, nb);
61}
62EXPORT_SYMBOL_GPL(register_pm_notifier);
63
64int unregister_pm_notifier(struct notifier_block *nb)
65{
66 return blocking_notifier_chain_unregister(&pm_chain_head, nb);
67}
68EXPORT_SYMBOL_GPL(unregister_pm_notifier);
69
70int __pm_notifier_call_chain(unsigned long val, int nr_to_call, int *nr_calls)
71{
72 int ret;
73
74 ret = __blocking_notifier_call_chain(&pm_chain_head, val, NULL,
75 nr_to_call, nr_calls);
76
77 return notifier_to_errno(ret);
78}
79int pm_notifier_call_chain(unsigned long val)
80{
81 return __pm_notifier_call_chain(val, -1, NULL);
82}
83
84/* If set, devices may be suspended and resumed asynchronously. */
85int pm_async_enabled = 1;
86
87static ssize_t pm_async_show(struct kobject *kobj, struct kobj_attribute *attr,
88 char *buf)
89{
90 return sprintf(buf, "%d\n", pm_async_enabled);
91}
92
93static ssize_t pm_async_store(struct kobject *kobj, struct kobj_attribute *attr,
94 const char *buf, size_t n)
95{
96 unsigned long val;
97
98 if (kstrtoul(buf, 10, &val))
99 return -EINVAL;
100
101 if (val > 1)
102 return -EINVAL;
103
104 pm_async_enabled = val;
105 return n;
106}
107
108power_attr(pm_async);
109
110#ifdef CONFIG_SUSPEND
111static ssize_t mem_sleep_show(struct kobject *kobj, struct kobj_attribute *attr,
112 char *buf)
113{
114 char *s = buf;
115 suspend_state_t i;
116
117 for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++)
118 if (mem_sleep_states[i]) {
119 const char *label = mem_sleep_states[i];
120
121 if (mem_sleep_current == i)
122 s += sprintf(s, "[%s] ", label);
123 else
124 s += sprintf(s, "%s ", label);
125 }
126
127 /* Convert the last space to a newline if needed. */
128 if (s != buf)
129 *(s-1) = '\n';
130
131 return (s - buf);
132}
133
134static suspend_state_t decode_suspend_state(const char *buf, size_t n)
135{
136 suspend_state_t state;
137 char *p;
138 int len;
139
140 p = memchr(buf, '\n', n);
141 len = p ? p - buf : n;
142
143 for (state = PM_SUSPEND_MIN; state < PM_SUSPEND_MAX; state++) {
144 const char *label = mem_sleep_states[state];
145
146 if (label && len == strlen(label) && !strncmp(buf, label, len))
147 return state;
148 }
149
150 return PM_SUSPEND_ON;
151}
152
153static ssize_t mem_sleep_store(struct kobject *kobj, struct kobj_attribute *attr,
154 const char *buf, size_t n)
155{
156 suspend_state_t state;
157 int error;
158
159 error = pm_autosleep_lock();
160 if (error)
161 return error;
162
163 if (pm_autosleep_state() > PM_SUSPEND_ON) {
164 error = -EBUSY;
165 goto out;
166 }
167
168 state = decode_suspend_state(buf, n);
169 if (state < PM_SUSPEND_MAX && state > PM_SUSPEND_ON)
170 mem_sleep_current = state;
171 else
172 error = -EINVAL;
173
174 out:
175 pm_autosleep_unlock();
176 return error ? error : n;
177}
178
179power_attr(mem_sleep);
180#endif /* CONFIG_SUSPEND */
181
182#ifdef CONFIG_PM_SLEEP_DEBUG
183int pm_test_level = TEST_NONE;
184
185static const char * const pm_tests[__TEST_AFTER_LAST] = {
186 [TEST_NONE] = "none",
187 [TEST_CORE] = "core",
188 [TEST_CPUS] = "processors",
189 [TEST_PLATFORM] = "platform",
190 [TEST_DEVICES] = "devices",
191 [TEST_FREEZER] = "freezer",
192};
193
194static ssize_t pm_test_show(struct kobject *kobj, struct kobj_attribute *attr,
195 char *buf)
196{
197 char *s = buf;
198 int level;
199
200 for (level = TEST_FIRST; level <= TEST_MAX; level++)
201 if (pm_tests[level]) {
202 if (level == pm_test_level)
203 s += sprintf(s, "[%s] ", pm_tests[level]);
204 else
205 s += sprintf(s, "%s ", pm_tests[level]);
206 }
207
208 if (s != buf)
209 /* convert the last space to a newline */
210 *(s-1) = '\n';
211
212 return (s - buf);
213}
214
215static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
216 const char *buf, size_t n)
217{
218 const char * const *s;
219 int level;
220 char *p;
221 int len;
222 int error = -EINVAL;
223
224 p = memchr(buf, '\n', n);
225 len = p ? p - buf : n;
226
227 lock_system_sleep();
228
229 level = TEST_FIRST;
230 for (s = &pm_tests[level]; level <= TEST_MAX; s++, level++)
231 if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) {
232 pm_test_level = level;
233 error = 0;
234 break;
235 }
236
237 unlock_system_sleep();
238
239 return error ? error : n;
240}
241
242power_attr(pm_test);
243#endif /* CONFIG_PM_SLEEP_DEBUG */
244
245#ifdef CONFIG_DEBUG_FS
246static char *suspend_step_name(enum suspend_stat_step step)
247{
248 switch (step) {
249 case SUSPEND_FREEZE:
250 return "freeze";
251 case SUSPEND_PREPARE:
252 return "prepare";
253 case SUSPEND_SUSPEND:
254 return "suspend";
255 case SUSPEND_SUSPEND_NOIRQ:
256 return "suspend_noirq";
257 case SUSPEND_RESUME_NOIRQ:
258 return "resume_noirq";
259 case SUSPEND_RESUME:
260 return "resume";
261 default:
262 return "";
263 }
264}
265
266static int suspend_stats_show(struct seq_file *s, void *unused)
267{
268 int i, index, last_dev, last_errno, last_step;
269
270 last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
271 last_dev %= REC_FAILED_NUM;
272 last_errno = suspend_stats.last_failed_errno + REC_FAILED_NUM - 1;
273 last_errno %= REC_FAILED_NUM;
274 last_step = suspend_stats.last_failed_step + REC_FAILED_NUM - 1;
275 last_step %= REC_FAILED_NUM;
276 seq_printf(s, "%s: %d\n%s: %d\n%s: %d\n%s: %d\n%s: %d\n"
277 "%s: %d\n%s: %d\n%s: %d\n%s: %d\n%s: %d\n",
278 "success", suspend_stats.success,
279 "fail", suspend_stats.fail,
280 "failed_freeze", suspend_stats.failed_freeze,
281 "failed_prepare", suspend_stats.failed_prepare,
282 "failed_suspend", suspend_stats.failed_suspend,
283 "failed_suspend_late",
284 suspend_stats.failed_suspend_late,
285 "failed_suspend_noirq",
286 suspend_stats.failed_suspend_noirq,
287 "failed_resume", suspend_stats.failed_resume,
288 "failed_resume_early",
289 suspend_stats.failed_resume_early,
290 "failed_resume_noirq",
291 suspend_stats.failed_resume_noirq);
292 seq_printf(s, "failures:\n last_failed_dev:\t%-s\n",
293 suspend_stats.failed_devs[last_dev]);
294 for (i = 1; i < REC_FAILED_NUM; i++) {
295 index = last_dev + REC_FAILED_NUM - i;
296 index %= REC_FAILED_NUM;
297 seq_printf(s, "\t\t\t%-s\n",
298 suspend_stats.failed_devs[index]);
299 }
300 seq_printf(s, " last_failed_errno:\t%-d\n",
301 suspend_stats.errno[last_errno]);
302 for (i = 1; i < REC_FAILED_NUM; i++) {
303 index = last_errno + REC_FAILED_NUM - i;
304 index %= REC_FAILED_NUM;
305 seq_printf(s, "\t\t\t%-d\n",
306 suspend_stats.errno[index]);
307 }
308 seq_printf(s, " last_failed_step:\t%-s\n",
309 suspend_step_name(
310 suspend_stats.failed_steps[last_step]));
311 for (i = 1; i < REC_FAILED_NUM; i++) {
312 index = last_step + REC_FAILED_NUM - i;
313 index %= REC_FAILED_NUM;
314 seq_printf(s, "\t\t\t%-s\n",
315 suspend_step_name(
316 suspend_stats.failed_steps[index]));
317 }
318
319 return 0;
320}
321
322static int suspend_stats_open(struct inode *inode, struct file *file)
323{
324 return single_open(file, suspend_stats_show, NULL);
325}
326
327static const struct file_operations suspend_stats_operations = {
328 .open = suspend_stats_open,
329 .read = seq_read,
330 .llseek = seq_lseek,
331 .release = single_release,
332};
333
334static int __init pm_debugfs_init(void)
335{
336 debugfs_create_file("suspend_stats", S_IFREG | S_IRUGO,
337 NULL, NULL, &suspend_stats_operations);
338 return 0;
339}
340
341late_initcall(pm_debugfs_init);
342#endif /* CONFIG_DEBUG_FS */
343
344#endif /* CONFIG_PM_SLEEP */
345
346#ifdef CONFIG_PM_SLEEP_DEBUG
347/*
348 * pm_print_times: print time taken by devices to suspend and resume.
349 *
350 * show() returns whether printing of suspend and resume times is enabled.
351 * store() accepts 0 or 1. 0 disables printing and 1 enables it.
352 */
353bool pm_print_times_enabled;
354
355static ssize_t pm_print_times_show(struct kobject *kobj,
356 struct kobj_attribute *attr, char *buf)
357{
358 return sprintf(buf, "%d\n", pm_print_times_enabled);
359}
360
361static ssize_t pm_print_times_store(struct kobject *kobj,
362 struct kobj_attribute *attr,
363 const char *buf, size_t n)
364{
365 unsigned long val;
366
367 if (kstrtoul(buf, 10, &val))
368 return -EINVAL;
369
370 if (val > 1)
371 return -EINVAL;
372
373 pm_print_times_enabled = !!val;
374 return n;
375}
376
377power_attr(pm_print_times);
378
379static inline void pm_print_times_init(void)
380{
381 pm_print_times_enabled = !!initcall_debug;
382}
383
384static ssize_t pm_wakeup_irq_show(struct kobject *kobj,
385 struct kobj_attribute *attr,
386 char *buf)
387{
388 return pm_wakeup_irq ? sprintf(buf, "%u\n", pm_wakeup_irq) : -ENODATA;
389}
390
391power_attr_ro(pm_wakeup_irq);
392
393bool pm_debug_messages_on __read_mostly;
394
395static ssize_t pm_debug_messages_show(struct kobject *kobj,
396 struct kobj_attribute *attr, char *buf)
397{
398 return sprintf(buf, "%d\n", pm_debug_messages_on);
399}
400
401static ssize_t pm_debug_messages_store(struct kobject *kobj,
402 struct kobj_attribute *attr,
403 const char *buf, size_t n)
404{
405 unsigned long val;
406
407 if (kstrtoul(buf, 10, &val))
408 return -EINVAL;
409
410 if (val > 1)
411 return -EINVAL;
412
413 pm_debug_messages_on = !!val;
414 return n;
415}
416
417power_attr(pm_debug_messages);
418
419/**
420 * __pm_pr_dbg - Print a suspend debug message to the kernel log.
421 * @defer: Whether or not to use printk_deferred() to print the message.
422 * @fmt: Message format.
423 *
424 * The message will be emitted if enabled through the pm_debug_messages
425 * sysfs attribute.
426 */
427void __pm_pr_dbg(bool defer, const char *fmt, ...)
428{
429 struct va_format vaf;
430 va_list args;
431
432 if (!pm_debug_messages_on)
433 return;
434
435 va_start(args, fmt);
436
437 vaf.fmt = fmt;
438 vaf.va = &args;
439
440 if (defer)
441 printk_deferred(KERN_DEBUG "PM: %pV", &vaf);
442 else
443 printk(KERN_DEBUG "PM: %pV", &vaf);
444
445 va_end(args);
446}
447
448#else /* !CONFIG_PM_SLEEP_DEBUG */
449static inline void pm_print_times_init(void) {}
450#endif /* CONFIG_PM_SLEEP_DEBUG */
451
452struct kobject *power_kobj;
453
454/**
455 * state - control system sleep states.
456 *
457 * show() returns available sleep state labels, which may be "mem", "standby",
458 * "freeze" and "disk" (hibernation). See Documentation/power/states.txt for a
459 * description of what they mean.
460 *
461 * store() accepts one of those strings, translates it into the proper
462 * enumerated value, and initiates a suspend transition.
463 */
464static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
465 char *buf)
466{
467 char *s = buf;
468#ifdef CONFIG_SUSPEND
469 suspend_state_t i;
470
471 for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++)
472 if (pm_states[i])
473 s += sprintf(s,"%s ", pm_states[i]);
474
475#endif
476 if (hibernation_available())
477 s += sprintf(s, "disk ");
478 if (s != buf)
479 /* convert the last space to a newline */
480 *(s-1) = '\n';
481 return (s - buf);
482}
483
484static suspend_state_t decode_state(const char *buf, size_t n)
485{
486#ifdef CONFIG_SUSPEND
487 suspend_state_t state;
488#endif
489 char *p;
490 int len;
491
492 p = memchr(buf, '\n', n);
493 len = p ? p - buf : n;
494
495 /* Check hibernation first. */
496 if (len == 4 && !strncmp(buf, "disk", len))
497 return PM_SUSPEND_MAX;
498
499#ifdef CONFIG_SUSPEND
500 for (state = PM_SUSPEND_MIN; state < PM_SUSPEND_MAX; state++) {
501 const char *label = pm_states[state];
502
503 if (label && len == strlen(label) && !strncmp(buf, label, len))
504 return state;
505 }
506#endif
507
508 return PM_SUSPEND_ON;
509}
510
511static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
512 const char *buf, size_t n)
513{
514 suspend_state_t state;
515 int error;
516
517 error = pm_autosleep_lock();
518 if (error)
519 return error;
520
521 if (pm_autosleep_state() > PM_SUSPEND_ON) {
522 error = -EBUSY;
523 goto out;
524 }
525
526 state = decode_state(buf, n);
527 if (state < PM_SUSPEND_MAX) {
528 if (state == PM_SUSPEND_MEM)
529 state = mem_sleep_current;
530
531 error = pm_suspend(state);
532 } else if (state == PM_SUSPEND_MAX) {
533 error = hibernate();
534 } else {
535 error = -EINVAL;
536 }
537
538 out:
539 pm_autosleep_unlock();
540 return error ? error : n;
541}
542
543power_attr(state);
544
545#ifdef CONFIG_PM_SLEEP
546/*
547 * The 'wakeup_count' attribute, along with the functions defined in
548 * drivers/base/power/wakeup.c, provides a means by which wakeup events can be
549 * handled in a non-racy way.
550 *
551 * If a wakeup event occurs when the system is in a sleep state, it simply is
552 * woken up. In turn, if an event that would wake the system up from a sleep
553 * state occurs when it is undergoing a transition to that sleep state, the
554 * transition should be aborted. Moreover, if such an event occurs when the
555 * system is in the working state, an attempt to start a transition to the
556 * given sleep state should fail during certain period after the detection of
557 * the event. Using the 'state' attribute alone is not sufficient to satisfy
558 * these requirements, because a wakeup event may occur exactly when 'state'
559 * is being written to and may be delivered to user space right before it is
560 * frozen, so the event will remain only partially processed until the system is
561 * woken up by another event. In particular, it won't cause the transition to
562 * a sleep state to be aborted.
563 *
564 * This difficulty may be overcome if user space uses 'wakeup_count' before
565 * writing to 'state'. It first should read from 'wakeup_count' and store
566 * the read value. Then, after carrying out its own preparations for the system
567 * transition to a sleep state, it should write the stored value to
568 * 'wakeup_count'. If that fails, at least one wakeup event has occurred since
569 * 'wakeup_count' was read and 'state' should not be written to. Otherwise, it
570 * is allowed to write to 'state', but the transition will be aborted if there
571 * are any wakeup events detected after 'wakeup_count' was written to.
572 */
573
574static ssize_t wakeup_count_show(struct kobject *kobj,
575 struct kobj_attribute *attr,
576 char *buf)
577{
578 unsigned int val;
579
580 return pm_get_wakeup_count(&val, true) ?
581 sprintf(buf, "%u\n", val) : -EINTR;
582}
583
584static ssize_t wakeup_count_store(struct kobject *kobj,
585 struct kobj_attribute *attr,
586 const char *buf, size_t n)
587{
588 unsigned int val;
589 int error;
590
591 error = pm_autosleep_lock();
592 if (error)
593 return error;
594
595 if (pm_autosleep_state() > PM_SUSPEND_ON) {
596 error = -EBUSY;
597 goto out;
598 }
599
600 error = -EINVAL;
601 if (sscanf(buf, "%u", &val) == 1) {
602 if (pm_save_wakeup_count(val))
603 error = n;
604 else
605 pm_print_active_wakeup_sources();
606 }
607
608 out:
609 pm_autosleep_unlock();
610 return error;
611}
612
613power_attr(wakeup_count);
614
615#ifdef CONFIG_PM_AUTOSLEEP
616static ssize_t autosleep_show(struct kobject *kobj,
617 struct kobj_attribute *attr,
618 char *buf)
619{
620 suspend_state_t state = pm_autosleep_state();
621
622 if (state == PM_SUSPEND_ON)
623 return sprintf(buf, "off\n");
624
625#ifdef CONFIG_SUSPEND
626 if (state < PM_SUSPEND_MAX)
627 return sprintf(buf, "%s\n", pm_states[state] ?
628 pm_states[state] : "error");
629#endif
630#ifdef CONFIG_HIBERNATION
631 return sprintf(buf, "disk\n");
632#else
633 return sprintf(buf, "error");
634#endif
635}
636
637static ssize_t autosleep_store(struct kobject *kobj,
638 struct kobj_attribute *attr,
639 const char *buf, size_t n)
640{
641 suspend_state_t state = decode_state(buf, n);
642 int error;
643
644 if (state == PM_SUSPEND_ON
645 && strcmp(buf, "off") && strcmp(buf, "off\n"))
646 return -EINVAL;
647
648 if (state == PM_SUSPEND_MEM)
649 state = mem_sleep_current;
650
651 error = pm_autosleep_set_state(state);
652 return error ? error : n;
653}
654
655power_attr(autosleep);
656#endif /* CONFIG_PM_AUTOSLEEP */
657
658#ifdef CONFIG_PM_WAKELOCKS
659static ssize_t wake_lock_show(struct kobject *kobj,
660 struct kobj_attribute *attr,
661 char *buf)
662{
663 return pm_show_wakelocks(buf, true);
664}
665
666static ssize_t wake_lock_store(struct kobject *kobj,
667 struct kobj_attribute *attr,
668 const char *buf, size_t n)
669{
670 int error = pm_wake_lock(buf);
671 return error ? error : n;
672}
673
674power_attr(wake_lock);
675
676static ssize_t wake_unlock_show(struct kobject *kobj,
677 struct kobj_attribute *attr,
678 char *buf)
679{
680 return pm_show_wakelocks(buf, false);
681}
682
683static ssize_t wake_unlock_store(struct kobject *kobj,
684 struct kobj_attribute *attr,
685 const char *buf, size_t n)
686{
687 int error = pm_wake_unlock(buf);
688 return error ? error : n;
689}
690
691power_attr(wake_unlock);
692
693#endif /* CONFIG_PM_WAKELOCKS */
694#endif /* CONFIG_PM_SLEEP */
695
696#ifdef CONFIG_PM_TRACE
697int pm_trace_enabled;
698
699static ssize_t pm_trace_show(struct kobject *kobj, struct kobj_attribute *attr,
700 char *buf)
701{
702 return sprintf(buf, "%d\n", pm_trace_enabled);
703}
704
705static ssize_t
706pm_trace_store(struct kobject *kobj, struct kobj_attribute *attr,
707 const char *buf, size_t n)
708{
709 int val;
710
711 if (sscanf(buf, "%d", &val) == 1) {
712 pm_trace_enabled = !!val;
713 if (pm_trace_enabled) {
714 pr_warn("PM: Enabling pm_trace changes system date and time during resume.\n"
715 "PM: Correct system time has to be restored manually after resume.\n");
716 }
717 return n;
718 }
719 return -EINVAL;
720}
721
722power_attr(pm_trace);
723
724static ssize_t pm_trace_dev_match_show(struct kobject *kobj,
725 struct kobj_attribute *attr,
726 char *buf)
727{
728 return show_trace_dev_match(buf, PAGE_SIZE);
729}
730
731power_attr_ro(pm_trace_dev_match);
732
733#endif /* CONFIG_PM_TRACE */
734
735#ifdef CONFIG_FREEZER
736static ssize_t pm_freeze_timeout_show(struct kobject *kobj,
737 struct kobj_attribute *attr, char *buf)
738{
739 return sprintf(buf, "%u\n", freeze_timeout_msecs);
740}
741
742static ssize_t pm_freeze_timeout_store(struct kobject *kobj,
743 struct kobj_attribute *attr,
744 const char *buf, size_t n)
745{
746 unsigned long val;
747
748 if (kstrtoul(buf, 10, &val))
749 return -EINVAL;
750
751 freeze_timeout_msecs = val;
752 return n;
753}
754
755power_attr(pm_freeze_timeout);
756
757#endif /* CONFIG_FREEZER*/
758
759static struct attribute * g[] = {
760 &state_attr.attr,
761#ifdef CONFIG_PM_TRACE
762 &pm_trace_attr.attr,
763 &pm_trace_dev_match_attr.attr,
764#endif
765#ifdef CONFIG_PM_SLEEP
766 &pm_async_attr.attr,
767 &wakeup_count_attr.attr,
768#ifdef CONFIG_SUSPEND
769 &mem_sleep_attr.attr,
770#endif
771#ifdef CONFIG_PM_AUTOSLEEP
772 &autosleep_attr.attr,
773#endif
774#ifdef CONFIG_PM_WAKELOCKS
775 &wake_lock_attr.attr,
776 &wake_unlock_attr.attr,
777#endif
778#ifdef CONFIG_PM_SLEEP_DEBUG
779 &pm_test_attr.attr,
780 &pm_print_times_attr.attr,
781 &pm_wakeup_irq_attr.attr,
782 &pm_debug_messages_attr.attr,
783#endif
784#endif
785#ifdef CONFIG_FREEZER
786 &pm_freeze_timeout_attr.attr,
787#endif
788 NULL,
789};
790
791static const struct attribute_group attr_group = {
792 .attrs = g,
793};
794
795struct workqueue_struct *pm_wq;
796EXPORT_SYMBOL_GPL(pm_wq);
797
798static int __init pm_start_workqueue(void)
799{
800 pm_wq = alloc_workqueue("pm", WQ_FREEZABLE, 0);
801
802 return pm_wq ? 0 : -ENOMEM;
803}
804
805static int __init pm_init(void)
806{
807 int error = pm_start_workqueue();
808 if (error)
809 return error;
810 hibernate_image_size_init();
811 hibernate_reserved_size_init();
812 pm_states_init();
813 power_kobj = kobject_create_and_add("power", NULL);
814 if (!power_kobj)
815 return -ENOMEM;
816 error = sysfs_create_group(power_kobj, &attr_group);
817 if (error)
818 return error;
819 pm_print_times_init();
820 return pm_autosleep_init();
821}
822
823core_initcall(pm_init);
1/*
2 * kernel/power/main.c - PM subsystem core functionality.
3 *
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Open Source Development Lab
6 *
7 * This file is released under the GPLv2
8 *
9 */
10
11#include <linux/export.h>
12#include <linux/kobject.h>
13#include <linux/string.h>
14#include <linux/pm-trace.h>
15#include <linux/workqueue.h>
16#include <linux/debugfs.h>
17#include <linux/seq_file.h>
18
19#include "power.h"
20
21DEFINE_MUTEX(pm_mutex);
22
23#ifdef CONFIG_PM_SLEEP
24
25/* Routines for PM-transition notifications */
26
27static BLOCKING_NOTIFIER_HEAD(pm_chain_head);
28
29int register_pm_notifier(struct notifier_block *nb)
30{
31 return blocking_notifier_chain_register(&pm_chain_head, nb);
32}
33EXPORT_SYMBOL_GPL(register_pm_notifier);
34
35int unregister_pm_notifier(struct notifier_block *nb)
36{
37 return blocking_notifier_chain_unregister(&pm_chain_head, nb);
38}
39EXPORT_SYMBOL_GPL(unregister_pm_notifier);
40
41int __pm_notifier_call_chain(unsigned long val, int nr_to_call, int *nr_calls)
42{
43 int ret;
44
45 ret = __blocking_notifier_call_chain(&pm_chain_head, val, NULL,
46 nr_to_call, nr_calls);
47
48 return notifier_to_errno(ret);
49}
50int pm_notifier_call_chain(unsigned long val)
51{
52 return __pm_notifier_call_chain(val, -1, NULL);
53}
54
55/* If set, devices may be suspended and resumed asynchronously. */
56int pm_async_enabled = 1;
57
58static ssize_t pm_async_show(struct kobject *kobj, struct kobj_attribute *attr,
59 char *buf)
60{
61 return sprintf(buf, "%d\n", pm_async_enabled);
62}
63
64static ssize_t pm_async_store(struct kobject *kobj, struct kobj_attribute *attr,
65 const char *buf, size_t n)
66{
67 unsigned long val;
68
69 if (kstrtoul(buf, 10, &val))
70 return -EINVAL;
71
72 if (val > 1)
73 return -EINVAL;
74
75 pm_async_enabled = val;
76 return n;
77}
78
79power_attr(pm_async);
80
81#ifdef CONFIG_SUSPEND
82static ssize_t mem_sleep_show(struct kobject *kobj, struct kobj_attribute *attr,
83 char *buf)
84{
85 char *s = buf;
86 suspend_state_t i;
87
88 for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++)
89 if (mem_sleep_states[i]) {
90 const char *label = mem_sleep_states[i];
91
92 if (mem_sleep_current == i)
93 s += sprintf(s, "[%s] ", label);
94 else
95 s += sprintf(s, "%s ", label);
96 }
97
98 /* Convert the last space to a newline if needed. */
99 if (s != buf)
100 *(s-1) = '\n';
101
102 return (s - buf);
103}
104
105static suspend_state_t decode_suspend_state(const char *buf, size_t n)
106{
107 suspend_state_t state;
108 char *p;
109 int len;
110
111 p = memchr(buf, '\n', n);
112 len = p ? p - buf : n;
113
114 for (state = PM_SUSPEND_MIN; state < PM_SUSPEND_MAX; state++) {
115 const char *label = mem_sleep_states[state];
116
117 if (label && len == strlen(label) && !strncmp(buf, label, len))
118 return state;
119 }
120
121 return PM_SUSPEND_ON;
122}
123
124static ssize_t mem_sleep_store(struct kobject *kobj, struct kobj_attribute *attr,
125 const char *buf, size_t n)
126{
127 suspend_state_t state;
128 int error;
129
130 error = pm_autosleep_lock();
131 if (error)
132 return error;
133
134 if (pm_autosleep_state() > PM_SUSPEND_ON) {
135 error = -EBUSY;
136 goto out;
137 }
138
139 state = decode_suspend_state(buf, n);
140 if (state < PM_SUSPEND_MAX && state > PM_SUSPEND_ON)
141 mem_sleep_current = state;
142 else
143 error = -EINVAL;
144
145 out:
146 pm_autosleep_unlock();
147 return error ? error : n;
148}
149
150power_attr(mem_sleep);
151#endif /* CONFIG_SUSPEND */
152
153#ifdef CONFIG_PM_DEBUG
154int pm_test_level = TEST_NONE;
155
156static const char * const pm_tests[__TEST_AFTER_LAST] = {
157 [TEST_NONE] = "none",
158 [TEST_CORE] = "core",
159 [TEST_CPUS] = "processors",
160 [TEST_PLATFORM] = "platform",
161 [TEST_DEVICES] = "devices",
162 [TEST_FREEZER] = "freezer",
163};
164
165static ssize_t pm_test_show(struct kobject *kobj, struct kobj_attribute *attr,
166 char *buf)
167{
168 char *s = buf;
169 int level;
170
171 for (level = TEST_FIRST; level <= TEST_MAX; level++)
172 if (pm_tests[level]) {
173 if (level == pm_test_level)
174 s += sprintf(s, "[%s] ", pm_tests[level]);
175 else
176 s += sprintf(s, "%s ", pm_tests[level]);
177 }
178
179 if (s != buf)
180 /* convert the last space to a newline */
181 *(s-1) = '\n';
182
183 return (s - buf);
184}
185
186static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
187 const char *buf, size_t n)
188{
189 const char * const *s;
190 int level;
191 char *p;
192 int len;
193 int error = -EINVAL;
194
195 p = memchr(buf, '\n', n);
196 len = p ? p - buf : n;
197
198 lock_system_sleep();
199
200 level = TEST_FIRST;
201 for (s = &pm_tests[level]; level <= TEST_MAX; s++, level++)
202 if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) {
203 pm_test_level = level;
204 error = 0;
205 break;
206 }
207
208 unlock_system_sleep();
209
210 return error ? error : n;
211}
212
213power_attr(pm_test);
214#endif /* CONFIG_PM_DEBUG */
215
216#ifdef CONFIG_DEBUG_FS
217static char *suspend_step_name(enum suspend_stat_step step)
218{
219 switch (step) {
220 case SUSPEND_FREEZE:
221 return "freeze";
222 case SUSPEND_PREPARE:
223 return "prepare";
224 case SUSPEND_SUSPEND:
225 return "suspend";
226 case SUSPEND_SUSPEND_NOIRQ:
227 return "suspend_noirq";
228 case SUSPEND_RESUME_NOIRQ:
229 return "resume_noirq";
230 case SUSPEND_RESUME:
231 return "resume";
232 default:
233 return "";
234 }
235}
236
237static int suspend_stats_show(struct seq_file *s, void *unused)
238{
239 int i, index, last_dev, last_errno, last_step;
240
241 last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
242 last_dev %= REC_FAILED_NUM;
243 last_errno = suspend_stats.last_failed_errno + REC_FAILED_NUM - 1;
244 last_errno %= REC_FAILED_NUM;
245 last_step = suspend_stats.last_failed_step + REC_FAILED_NUM - 1;
246 last_step %= REC_FAILED_NUM;
247 seq_printf(s, "%s: %d\n%s: %d\n%s: %d\n%s: %d\n%s: %d\n"
248 "%s: %d\n%s: %d\n%s: %d\n%s: %d\n%s: %d\n",
249 "success", suspend_stats.success,
250 "fail", suspend_stats.fail,
251 "failed_freeze", suspend_stats.failed_freeze,
252 "failed_prepare", suspend_stats.failed_prepare,
253 "failed_suspend", suspend_stats.failed_suspend,
254 "failed_suspend_late",
255 suspend_stats.failed_suspend_late,
256 "failed_suspend_noirq",
257 suspend_stats.failed_suspend_noirq,
258 "failed_resume", suspend_stats.failed_resume,
259 "failed_resume_early",
260 suspend_stats.failed_resume_early,
261 "failed_resume_noirq",
262 suspend_stats.failed_resume_noirq);
263 seq_printf(s, "failures:\n last_failed_dev:\t%-s\n",
264 suspend_stats.failed_devs[last_dev]);
265 for (i = 1; i < REC_FAILED_NUM; i++) {
266 index = last_dev + REC_FAILED_NUM - i;
267 index %= REC_FAILED_NUM;
268 seq_printf(s, "\t\t\t%-s\n",
269 suspend_stats.failed_devs[index]);
270 }
271 seq_printf(s, " last_failed_errno:\t%-d\n",
272 suspend_stats.errno[last_errno]);
273 for (i = 1; i < REC_FAILED_NUM; i++) {
274 index = last_errno + REC_FAILED_NUM - i;
275 index %= REC_FAILED_NUM;
276 seq_printf(s, "\t\t\t%-d\n",
277 suspend_stats.errno[index]);
278 }
279 seq_printf(s, " last_failed_step:\t%-s\n",
280 suspend_step_name(
281 suspend_stats.failed_steps[last_step]));
282 for (i = 1; i < REC_FAILED_NUM; i++) {
283 index = last_step + REC_FAILED_NUM - i;
284 index %= REC_FAILED_NUM;
285 seq_printf(s, "\t\t\t%-s\n",
286 suspend_step_name(
287 suspend_stats.failed_steps[index]));
288 }
289
290 return 0;
291}
292
293static int suspend_stats_open(struct inode *inode, struct file *file)
294{
295 return single_open(file, suspend_stats_show, NULL);
296}
297
298static const struct file_operations suspend_stats_operations = {
299 .open = suspend_stats_open,
300 .read = seq_read,
301 .llseek = seq_lseek,
302 .release = single_release,
303};
304
305static int __init pm_debugfs_init(void)
306{
307 debugfs_create_file("suspend_stats", S_IFREG | S_IRUGO,
308 NULL, NULL, &suspend_stats_operations);
309 return 0;
310}
311
312late_initcall(pm_debugfs_init);
313#endif /* CONFIG_DEBUG_FS */
314
315#endif /* CONFIG_PM_SLEEP */
316
317#ifdef CONFIG_PM_SLEEP_DEBUG
318/*
319 * pm_print_times: print time taken by devices to suspend and resume.
320 *
321 * show() returns whether printing of suspend and resume times is enabled.
322 * store() accepts 0 or 1. 0 disables printing and 1 enables it.
323 */
324bool pm_print_times_enabled;
325
326static ssize_t pm_print_times_show(struct kobject *kobj,
327 struct kobj_attribute *attr, char *buf)
328{
329 return sprintf(buf, "%d\n", pm_print_times_enabled);
330}
331
332static ssize_t pm_print_times_store(struct kobject *kobj,
333 struct kobj_attribute *attr,
334 const char *buf, size_t n)
335{
336 unsigned long val;
337
338 if (kstrtoul(buf, 10, &val))
339 return -EINVAL;
340
341 if (val > 1)
342 return -EINVAL;
343
344 pm_print_times_enabled = !!val;
345 return n;
346}
347
348power_attr(pm_print_times);
349
350static inline void pm_print_times_init(void)
351{
352 pm_print_times_enabled = !!initcall_debug;
353}
354
355static ssize_t pm_wakeup_irq_show(struct kobject *kobj,
356 struct kobj_attribute *attr,
357 char *buf)
358{
359 return pm_wakeup_irq ? sprintf(buf, "%u\n", pm_wakeup_irq) : -ENODATA;
360}
361
362power_attr_ro(pm_wakeup_irq);
363
364#else /* !CONFIG_PM_SLEEP_DEBUG */
365static inline void pm_print_times_init(void) {}
366#endif /* CONFIG_PM_SLEEP_DEBUG */
367
368struct kobject *power_kobj;
369
370/**
371 * state - control system sleep states.
372 *
373 * show() returns available sleep state labels, which may be "mem", "standby",
374 * "freeze" and "disk" (hibernation). See Documentation/power/states.txt for a
375 * description of what they mean.
376 *
377 * store() accepts one of those strings, translates it into the proper
378 * enumerated value, and initiates a suspend transition.
379 */
380static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
381 char *buf)
382{
383 char *s = buf;
384#ifdef CONFIG_SUSPEND
385 suspend_state_t i;
386
387 for (i = PM_SUSPEND_MIN; i < PM_SUSPEND_MAX; i++)
388 if (pm_states[i])
389 s += sprintf(s,"%s ", pm_states[i]);
390
391#endif
392 if (hibernation_available())
393 s += sprintf(s, "disk ");
394 if (s != buf)
395 /* convert the last space to a newline */
396 *(s-1) = '\n';
397 return (s - buf);
398}
399
400static suspend_state_t decode_state(const char *buf, size_t n)
401{
402#ifdef CONFIG_SUSPEND
403 suspend_state_t state;
404#endif
405 char *p;
406 int len;
407
408 p = memchr(buf, '\n', n);
409 len = p ? p - buf : n;
410
411 /* Check hibernation first. */
412 if (len == 4 && !strncmp(buf, "disk", len))
413 return PM_SUSPEND_MAX;
414
415#ifdef CONFIG_SUSPEND
416 for (state = PM_SUSPEND_MIN; state < PM_SUSPEND_MAX; state++) {
417 const char *label = pm_states[state];
418
419 if (label && len == strlen(label) && !strncmp(buf, label, len))
420 return state;
421 }
422#endif
423
424 return PM_SUSPEND_ON;
425}
426
427static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
428 const char *buf, size_t n)
429{
430 suspend_state_t state;
431 int error;
432
433 error = pm_autosleep_lock();
434 if (error)
435 return error;
436
437 if (pm_autosleep_state() > PM_SUSPEND_ON) {
438 error = -EBUSY;
439 goto out;
440 }
441
442 state = decode_state(buf, n);
443 if (state < PM_SUSPEND_MAX) {
444 if (state == PM_SUSPEND_MEM)
445 state = mem_sleep_current;
446
447 error = pm_suspend(state);
448 } else if (state == PM_SUSPEND_MAX) {
449 error = hibernate();
450 } else {
451 error = -EINVAL;
452 }
453
454 out:
455 pm_autosleep_unlock();
456 return error ? error : n;
457}
458
459power_attr(state);
460
461#ifdef CONFIG_PM_SLEEP
462/*
463 * The 'wakeup_count' attribute, along with the functions defined in
464 * drivers/base/power/wakeup.c, provides a means by which wakeup events can be
465 * handled in a non-racy way.
466 *
467 * If a wakeup event occurs when the system is in a sleep state, it simply is
468 * woken up. In turn, if an event that would wake the system up from a sleep
469 * state occurs when it is undergoing a transition to that sleep state, the
470 * transition should be aborted. Moreover, if such an event occurs when the
471 * system is in the working state, an attempt to start a transition to the
472 * given sleep state should fail during certain period after the detection of
473 * the event. Using the 'state' attribute alone is not sufficient to satisfy
474 * these requirements, because a wakeup event may occur exactly when 'state'
475 * is being written to and may be delivered to user space right before it is
476 * frozen, so the event will remain only partially processed until the system is
477 * woken up by another event. In particular, it won't cause the transition to
478 * a sleep state to be aborted.
479 *
480 * This difficulty may be overcome if user space uses 'wakeup_count' before
481 * writing to 'state'. It first should read from 'wakeup_count' and store
482 * the read value. Then, after carrying out its own preparations for the system
483 * transition to a sleep state, it should write the stored value to
484 * 'wakeup_count'. If that fails, at least one wakeup event has occurred since
485 * 'wakeup_count' was read and 'state' should not be written to. Otherwise, it
486 * is allowed to write to 'state', but the transition will be aborted if there
487 * are any wakeup events detected after 'wakeup_count' was written to.
488 */
489
490static ssize_t wakeup_count_show(struct kobject *kobj,
491 struct kobj_attribute *attr,
492 char *buf)
493{
494 unsigned int val;
495
496 return pm_get_wakeup_count(&val, true) ?
497 sprintf(buf, "%u\n", val) : -EINTR;
498}
499
500static ssize_t wakeup_count_store(struct kobject *kobj,
501 struct kobj_attribute *attr,
502 const char *buf, size_t n)
503{
504 unsigned int val;
505 int error;
506
507 error = pm_autosleep_lock();
508 if (error)
509 return error;
510
511 if (pm_autosleep_state() > PM_SUSPEND_ON) {
512 error = -EBUSY;
513 goto out;
514 }
515
516 error = -EINVAL;
517 if (sscanf(buf, "%u", &val) == 1) {
518 if (pm_save_wakeup_count(val))
519 error = n;
520 else
521 pm_print_active_wakeup_sources();
522 }
523
524 out:
525 pm_autosleep_unlock();
526 return error;
527}
528
529power_attr(wakeup_count);
530
531#ifdef CONFIG_PM_AUTOSLEEP
532static ssize_t autosleep_show(struct kobject *kobj,
533 struct kobj_attribute *attr,
534 char *buf)
535{
536 suspend_state_t state = pm_autosleep_state();
537
538 if (state == PM_SUSPEND_ON)
539 return sprintf(buf, "off\n");
540
541#ifdef CONFIG_SUSPEND
542 if (state < PM_SUSPEND_MAX)
543 return sprintf(buf, "%s\n", pm_states[state] ?
544 pm_states[state] : "error");
545#endif
546#ifdef CONFIG_HIBERNATION
547 return sprintf(buf, "disk\n");
548#else
549 return sprintf(buf, "error");
550#endif
551}
552
553static ssize_t autosleep_store(struct kobject *kobj,
554 struct kobj_attribute *attr,
555 const char *buf, size_t n)
556{
557 suspend_state_t state = decode_state(buf, n);
558 int error;
559
560 if (state == PM_SUSPEND_ON
561 && strcmp(buf, "off") && strcmp(buf, "off\n"))
562 return -EINVAL;
563
564 if (state == PM_SUSPEND_MEM)
565 state = mem_sleep_current;
566
567 error = pm_autosleep_set_state(state);
568 return error ? error : n;
569}
570
571power_attr(autosleep);
572#endif /* CONFIG_PM_AUTOSLEEP */
573
574#ifdef CONFIG_PM_WAKELOCKS
575static ssize_t wake_lock_show(struct kobject *kobj,
576 struct kobj_attribute *attr,
577 char *buf)
578{
579 return pm_show_wakelocks(buf, true);
580}
581
582static ssize_t wake_lock_store(struct kobject *kobj,
583 struct kobj_attribute *attr,
584 const char *buf, size_t n)
585{
586 int error = pm_wake_lock(buf);
587 return error ? error : n;
588}
589
590power_attr(wake_lock);
591
592static ssize_t wake_unlock_show(struct kobject *kobj,
593 struct kobj_attribute *attr,
594 char *buf)
595{
596 return pm_show_wakelocks(buf, false);
597}
598
599static ssize_t wake_unlock_store(struct kobject *kobj,
600 struct kobj_attribute *attr,
601 const char *buf, size_t n)
602{
603 int error = pm_wake_unlock(buf);
604 return error ? error : n;
605}
606
607power_attr(wake_unlock);
608
609#endif /* CONFIG_PM_WAKELOCKS */
610#endif /* CONFIG_PM_SLEEP */
611
612#ifdef CONFIG_PM_TRACE
613int pm_trace_enabled;
614
615static ssize_t pm_trace_show(struct kobject *kobj, struct kobj_attribute *attr,
616 char *buf)
617{
618 return sprintf(buf, "%d\n", pm_trace_enabled);
619}
620
621static ssize_t
622pm_trace_store(struct kobject *kobj, struct kobj_attribute *attr,
623 const char *buf, size_t n)
624{
625 int val;
626
627 if (sscanf(buf, "%d", &val) == 1) {
628 pm_trace_enabled = !!val;
629 if (pm_trace_enabled) {
630 pr_warn("PM: Enabling pm_trace changes system date and time during resume.\n"
631 "PM: Correct system time has to be restored manually after resume.\n");
632 }
633 return n;
634 }
635 return -EINVAL;
636}
637
638power_attr(pm_trace);
639
640static ssize_t pm_trace_dev_match_show(struct kobject *kobj,
641 struct kobj_attribute *attr,
642 char *buf)
643{
644 return show_trace_dev_match(buf, PAGE_SIZE);
645}
646
647power_attr_ro(pm_trace_dev_match);
648
649#endif /* CONFIG_PM_TRACE */
650
651#ifdef CONFIG_FREEZER
652static ssize_t pm_freeze_timeout_show(struct kobject *kobj,
653 struct kobj_attribute *attr, char *buf)
654{
655 return sprintf(buf, "%u\n", freeze_timeout_msecs);
656}
657
658static ssize_t pm_freeze_timeout_store(struct kobject *kobj,
659 struct kobj_attribute *attr,
660 const char *buf, size_t n)
661{
662 unsigned long val;
663
664 if (kstrtoul(buf, 10, &val))
665 return -EINVAL;
666
667 freeze_timeout_msecs = val;
668 return n;
669}
670
671power_attr(pm_freeze_timeout);
672
673#endif /* CONFIG_FREEZER*/
674
675static struct attribute * g[] = {
676 &state_attr.attr,
677#ifdef CONFIG_PM_TRACE
678 &pm_trace_attr.attr,
679 &pm_trace_dev_match_attr.attr,
680#endif
681#ifdef CONFIG_PM_SLEEP
682 &pm_async_attr.attr,
683 &wakeup_count_attr.attr,
684#ifdef CONFIG_SUSPEND
685 &mem_sleep_attr.attr,
686#endif
687#ifdef CONFIG_PM_AUTOSLEEP
688 &autosleep_attr.attr,
689#endif
690#ifdef CONFIG_PM_WAKELOCKS
691 &wake_lock_attr.attr,
692 &wake_unlock_attr.attr,
693#endif
694#ifdef CONFIG_PM_DEBUG
695 &pm_test_attr.attr,
696#endif
697#ifdef CONFIG_PM_SLEEP_DEBUG
698 &pm_print_times_attr.attr,
699 &pm_wakeup_irq_attr.attr,
700#endif
701#endif
702#ifdef CONFIG_FREEZER
703 &pm_freeze_timeout_attr.attr,
704#endif
705 NULL,
706};
707
708static struct attribute_group attr_group = {
709 .attrs = g,
710};
711
712struct workqueue_struct *pm_wq;
713EXPORT_SYMBOL_GPL(pm_wq);
714
715static int __init pm_start_workqueue(void)
716{
717 pm_wq = alloc_workqueue("pm", WQ_FREEZABLE, 0);
718
719 return pm_wq ? 0 : -ENOMEM;
720}
721
722static int __init pm_init(void)
723{
724 int error = pm_start_workqueue();
725 if (error)
726 return error;
727 hibernate_image_size_init();
728 hibernate_reserved_size_init();
729 pm_states_init();
730 power_kobj = kobject_create_and_add("power", NULL);
731 if (!power_kobj)
732 return -ENOMEM;
733 error = sysfs_create_group(power_kobj, &attr_group);
734 if (error)
735 return error;
736 pm_print_times_init();
737 return pm_autosleep_init();
738}
739
740core_initcall(pm_init);