Merge tag 'pm-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
[muen/linux.git] / kernel / power / main.c
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
21 DEFINE_MUTEX(pm_mutex);
22
23 #ifdef CONFIG_PM_SLEEP
24
25 /* Routines for PM-transition notifications */
26
27 static BLOCKING_NOTIFIER_HEAD(pm_chain_head);
28
29 int register_pm_notifier(struct notifier_block *nb)
30 {
31         return blocking_notifier_chain_register(&pm_chain_head, nb);
32 }
33 EXPORT_SYMBOL_GPL(register_pm_notifier);
34
35 int unregister_pm_notifier(struct notifier_block *nb)
36 {
37         return blocking_notifier_chain_unregister(&pm_chain_head, nb);
38 }
39 EXPORT_SYMBOL_GPL(unregister_pm_notifier);
40
41 int __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 }
50 int 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. */
56 int pm_async_enabled = 1;
57
58 static 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
64 static 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
79 power_attr(pm_async);
80
81 #ifdef CONFIG_SUSPEND
82 static 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
105 static 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
124 static 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
150 power_attr(mem_sleep);
151 #endif /* CONFIG_SUSPEND */
152
153 #ifdef CONFIG_PM_DEBUG
154 int pm_test_level = TEST_NONE;
155
156 static 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
165 static 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
186 static 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
213 power_attr(pm_test);
214 #endif /* CONFIG_PM_DEBUG */
215
216 #ifdef CONFIG_DEBUG_FS
217 static 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
237 static 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
293 static int suspend_stats_open(struct inode *inode, struct file *file)
294 {
295         return single_open(file, suspend_stats_show, NULL);
296 }
297
298 static 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
305 static 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
312 late_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  */
324 bool pm_print_times_enabled;
325
326 static 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
332 static 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
348 power_attr(pm_print_times);
349
350 static inline void pm_print_times_init(void)
351 {
352         pm_print_times_enabled = !!initcall_debug;
353 }
354
355 static 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
362 power_attr_ro(pm_wakeup_irq);
363
364 #else /* !CONFIG_PM_SLEEP_DEBUG */
365 static inline void pm_print_times_init(void) {}
366 #endif /* CONFIG_PM_SLEEP_DEBUG */
367
368 struct 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  */
380 static 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
400 static 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
427 static 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
459 power_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
490 static 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
500 static 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
529 power_attr(wakeup_count);
530
531 #ifdef CONFIG_PM_AUTOSLEEP
532 static 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
553 static 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
571 power_attr(autosleep);
572 #endif /* CONFIG_PM_AUTOSLEEP */
573
574 #ifdef CONFIG_PM_WAKELOCKS
575 static 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
582 static 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
590 power_attr(wake_lock);
591
592 static 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
599 static 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
607 power_attr(wake_unlock);
608
609 #endif /* CONFIG_PM_WAKELOCKS */
610 #endif /* CONFIG_PM_SLEEP */
611
612 #ifdef CONFIG_PM_TRACE
613 int pm_trace_enabled;
614
615 static 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
621 static ssize_t
622 pm_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
638 power_attr(pm_trace);
639
640 static 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
647 power_attr_ro(pm_trace_dev_match);
648
649 #endif /* CONFIG_PM_TRACE */
650
651 #ifdef CONFIG_FREEZER
652 static 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
658 static 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
671 power_attr(pm_freeze_timeout);
672
673 #endif  /* CONFIG_FREEZER*/
674
675 static 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
708 static struct attribute_group attr_group = {
709         .attrs = g,
710 };
711
712 struct workqueue_struct *pm_wq;
713 EXPORT_SYMBOL_GPL(pm_wq);
714
715 static 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
722 static 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
740 core_initcall(pm_init);