projects/linux·blob v3.13 · refs

650 lines · 15.2 KiB

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/resume-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)
42{
43 int ret = blocking_notifier_call_chain(&pm_chain_head, val, NULL);
44
45 return notifier_to_errno(ret);
46}
47
48/* If set, devices may be suspended and resumed asynchronously. */
49int pm_async_enabled = 1;
50
51static ssize_t pm_async_show(struct kobject *kobj, struct kobj_attribute *attr,
52 char *buf)
53{
54 return sprintf(buf, "%d\n", pm_async_enabled);
55}
56
57static ssize_t pm_async_store(struct kobject *kobj, struct kobj_attribute *attr,
58 const char *buf, size_t n)
59{
60 unsigned long val;
61
62 if (kstrtoul(buf, 10, &val))
63 return -EINVAL;
64
65 if (val > 1)
66 return -EINVAL;
67
68 pm_async_enabled = val;
69 return n;
70}
71
72power_attr(pm_async);
73
74#ifdef CONFIG_PM_DEBUG
75int pm_test_level = TEST_NONE;
76
77static const char * const pm_tests[__TEST_AFTER_LAST] = {
78 [TEST_NONE] = "none",
79 [TEST_CORE] = "core",
80 [TEST_CPUS] = "processors",
81 [TEST_PLATFORM] = "platform",
82 [TEST_DEVICES] = "devices",
83 [TEST_FREEZER] = "freezer",
84};
85
86static ssize_t pm_test_show(struct kobject *kobj, struct kobj_attribute *attr,
87 char *buf)
88{
89 char *s = buf;
90 int level;
91
92 for (level = TEST_FIRST; level <= TEST_MAX; level++)
93 if (pm_tests[level]) {
94 if (level == pm_test_level)
95 s += sprintf(s, "[%s] ", pm_tests[level]);
96 else
97 s += sprintf(s, "%s ", pm_tests[level]);
98 }
99
100 if (s != buf)
101 /* convert the last space to a newline */
102 *(s-1) = '\n';
103
104 return (s - buf);
105}
106
107static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr,
108 const char *buf, size_t n)
109{
110 const char * const *s;
111 int level;
112 char *p;
113 int len;
114 int error = -EINVAL;
115
116 p = memchr(buf, '\n', n);
117 len = p ? p - buf : n;
118
119 lock_system_sleep();
120
121 level = TEST_FIRST;
122 for (s = &pm_tests[level]; level <= TEST_MAX; s++, level++)
123 if (*s && len == strlen(*s) && !strncmp(buf, *s, len)) {
124 pm_test_level = level;
125 error = 0;
126 break;
127 }
128
129 unlock_system_sleep();
130
131 return error ? error : n;
132}
133
134power_attr(pm_test);
135#endif /* CONFIG_PM_DEBUG */
136
137#ifdef CONFIG_DEBUG_FS
138static char *suspend_step_name(enum suspend_stat_step step)
139{
140 switch (step) {
141 case SUSPEND_FREEZE:
142 return "freeze";
143 case SUSPEND_PREPARE:
144 return "prepare";
145 case SUSPEND_SUSPEND:
146 return "suspend";
147 case SUSPEND_SUSPEND_NOIRQ:
148 return "suspend_noirq";
149 case SUSPEND_RESUME_NOIRQ:
150 return "resume_noirq";
151 case SUSPEND_RESUME:
152 return "resume";
153 default:
154 return "";
155 }
156}
157
158static int suspend_stats_show(struct seq_file *s, void *unused)
159{
160 int i, index, last_dev, last_errno, last_step;
161
162 last_dev = suspend_stats.last_failed_dev + REC_FAILED_NUM - 1;
163 last_dev %= REC_FAILED_NUM;
164 last_errno = suspend_stats.last_failed_errno + REC_FAILED_NUM - 1;
165 last_errno %= REC_FAILED_NUM;
166 last_step = suspend_stats.last_failed_step + REC_FAILED_NUM - 1;
167 last_step %= REC_FAILED_NUM;
168 seq_printf(s, "%s: %d\n%s: %d\n%s: %d\n%s: %d\n%s: %d\n"
169 "%s: %d\n%s: %d\n%s: %d\n%s: %d\n%s: %d\n",
170 "success", suspend_stats.success,
171 "fail", suspend_stats.fail,
172 "failed_freeze", suspend_stats.failed_freeze,
173 "failed_prepare", suspend_stats.failed_prepare,
174 "failed_suspend", suspend_stats.failed_suspend,
175 "failed_suspend_late",
176 suspend_stats.failed_suspend_late,
177 "failed_suspend_noirq",
178 suspend_stats.failed_suspend_noirq,
179 "failed_resume", suspend_stats.failed_resume,
180 "failed_resume_early",
181 suspend_stats.failed_resume_early,
182 "failed_resume_noirq",
183 suspend_stats.failed_resume_noirq);
184 seq_printf(s, "failures:\n last_failed_dev:\t%-s\n",
185 suspend_stats.failed_devs[last_dev]);
186 for (i = 1; i < REC_FAILED_NUM; i++) {
187 index = last_dev + REC_FAILED_NUM - i;
188 index %= REC_FAILED_NUM;
189 seq_printf(s, "\t\t\t%-s\n",
190 suspend_stats.failed_devs[index]);
191 }
192 seq_printf(s, " last_failed_errno:\t%-d\n",
193 suspend_stats.errno[last_errno]);
194 for (i = 1; i < REC_FAILED_NUM; i++) {
195 index = last_errno + REC_FAILED_NUM - i;
196 index %= REC_FAILED_NUM;
197 seq_printf(s, "\t\t\t%-d\n",
198 suspend_stats.errno[index]);
199 }
200 seq_printf(s, " last_failed_step:\t%-s\n",
201 suspend_step_name(
202 suspend_stats.failed_steps[last_step]));
203 for (i = 1; i < REC_FAILED_NUM; i++) {
204 index = last_step + REC_FAILED_NUM - i;
205 index %= REC_FAILED_NUM;
206 seq_printf(s, "\t\t\t%-s\n",
207 suspend_step_name(
208 suspend_stats.failed_steps[index]));
209 }
210
211 return 0;
212}
213
214static int suspend_stats_open(struct inode *inode, struct file *file)
215{
216 return single_open(file, suspend_stats_show, NULL);
217}
218
219static const struct file_operations suspend_stats_operations = {
220 .open = suspend_stats_open,
221 .read = seq_read,
222 .llseek = seq_lseek,
223 .release = single_release,
224};
225
226static int __init pm_debugfs_init(void)
227{
228 debugfs_create_file("suspend_stats", S_IFREG | S_IRUGO,
229 NULL, NULL, &suspend_stats_operations);
230 return 0;
231}
232
233late_initcall(pm_debugfs_init);
234#endif /* CONFIG_DEBUG_FS */
235
236#endif /* CONFIG_PM_SLEEP */
237
238#ifdef CONFIG_PM_SLEEP_DEBUG
239/*
240 * pm_print_times: print time taken by devices to suspend and resume.
241 *
242 * show() returns whether printing of suspend and resume times is enabled.
243 * store() accepts 0 or 1. 0 disables printing and 1 enables it.
244 */
245bool pm_print_times_enabled;
246
247static ssize_t pm_print_times_show(struct kobject *kobj,
248 struct kobj_attribute *attr, char *buf)
249{
250 return sprintf(buf, "%d\n", pm_print_times_enabled);
251}
252
253static ssize_t pm_print_times_store(struct kobject *kobj,
254 struct kobj_attribute *attr,
255 const char *buf, size_t n)
256{
257 unsigned long val;
258
259 if (kstrtoul(buf, 10, &val))
260 return -EINVAL;
261
262 if (val > 1)
263 return -EINVAL;
264
265 pm_print_times_enabled = !!val;
266 return n;
267}
268
269power_attr(pm_print_times);
270
271static inline void pm_print_times_init(void)
272{
273 pm_print_times_enabled = !!initcall_debug;
274}
275#else /* !CONFIG_PP_SLEEP_DEBUG */
276static inline void pm_print_times_init(void) {}
277#endif /* CONFIG_PM_SLEEP_DEBUG */
278
279struct kobject *power_kobj;
280
281/**
282 * state - control system power state.
283 *
284 * show() returns what states are supported, which is hard-coded to
285 * 'standby' (Power-On Suspend), 'mem' (Suspend-to-RAM), and
286 * 'disk' (Suspend-to-Disk).
287 *
288 * store() accepts one of those strings, translates it into the
289 * proper enumerated value, and initiates a suspend transition.
290 */
291static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
292 char *buf)
293{
294 char *s = buf;
295#ifdef CONFIG_SUSPEND
296 int i;
297
298 for (i = 0; i < PM_SUSPEND_MAX; i++) {
299 if (pm_states[i] && valid_state(i))
300 s += sprintf(s,"%s ", pm_states[i]);
301 }
302#endif
303#ifdef CONFIG_HIBERNATION
304 s += sprintf(s, "%s\n", "disk");
305#else
306 if (s != buf)
307 /* convert the last space to a newline */
308 *(s-1) = '\n';
309#endif
310 return (s - buf);
311}
312
313static suspend_state_t decode_state(const char *buf, size_t n)
314{
315#ifdef CONFIG_SUSPEND
316 suspend_state_t state = PM_SUSPEND_MIN;
317 const char * const *s;
318#endif
319 char *p;
320 int len;
321
322 p = memchr(buf, '\n', n);
323 len = p ? p - buf : n;
324
325 /* Check hibernation first. */
326 if (len == 4 && !strncmp(buf, "disk", len))
327 return PM_SUSPEND_MAX;
328
329#ifdef CONFIG_SUSPEND
330 for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++)
331 if (*s && len == strlen(*s) && !strncmp(buf, *s, len))
332 return state;
333#endif
334
335 return PM_SUSPEND_ON;
336}
337
338static ssize_t state_store(struct kobject *kobj, struct kobj_attribute *attr,
339 const char *buf, size_t n)
340{
341 suspend_state_t state;
342 int error;
343
344 error = pm_autosleep_lock();
345 if (error)
346 return error;
347
348 if (pm_autosleep_state() > PM_SUSPEND_ON) {
349 error = -EBUSY;
350 goto out;
351 }
352
353 state = decode_state(buf, n);
354 if (state < PM_SUSPEND_MAX)
355 error = pm_suspend(state);
356 else if (state == PM_SUSPEND_MAX)
357 error = hibernate();
358 else
359 error = -EINVAL;
360
361 out:
362 pm_autosleep_unlock();
363 return error ? error : n;
364}
365
366power_attr(state);
367
368#ifdef CONFIG_PM_SLEEP
369/*
370 * The 'wakeup_count' attribute, along with the functions defined in
371 * drivers/base/power/wakeup.c, provides a means by which wakeup events can be
372 * handled in a non-racy way.
373 *
374 * If a wakeup event occurs when the system is in a sleep state, it simply is
375 * woken up. In turn, if an event that would wake the system up from a sleep
376 * state occurs when it is undergoing a transition to that sleep state, the
377 * transition should be aborted. Moreover, if such an event occurs when the
378 * system is in the working state, an attempt to start a transition to the
379 * given sleep state should fail during certain period after the detection of
380 * the event. Using the 'state' attribute alone is not sufficient to satisfy
381 * these requirements, because a wakeup event may occur exactly when 'state'
382 * is being written to and may be delivered to user space right before it is
383 * frozen, so the event will remain only partially processed until the system is
384 * woken up by another event. In particular, it won't cause the transition to
385 * a sleep state to be aborted.
386 *
387 * This difficulty may be overcome if user space uses 'wakeup_count' before
388 * writing to 'state'. It first should read from 'wakeup_count' and store
389 * the read value. Then, after carrying out its own preparations for the system
390 * transition to a sleep state, it should write the stored value to
391 * 'wakeup_count'. If that fails, at least one wakeup event has occurred since
392 * 'wakeup_count' was read and 'state' should not be written to. Otherwise, it
393 * is allowed to write to 'state', but the transition will be aborted if there
394 * are any wakeup events detected after 'wakeup_count' was written to.
395 */
396
397static ssize_t wakeup_count_show(struct kobject *kobj,
398 struct kobj_attribute *attr,
399 char *buf)
400{
401 unsigned int val;
402
403 return pm_get_wakeup_count(&val, true) ?
404 sprintf(buf, "%u\n", val) : -EINTR;
405}
406
407static ssize_t wakeup_count_store(struct kobject *kobj,
408 struct kobj_attribute *attr,
409 const char *buf, size_t n)
410{
411 unsigned int val;
412 int error;
413
414 error = pm_autosleep_lock();
415 if (error)
416 return error;
417
418 if (pm_autosleep_state() > PM_SUSPEND_ON) {
419 error = -EBUSY;
420 goto out;
421 }
422
423 error = -EINVAL;
424 if (sscanf(buf, "%u", &val) == 1) {
425 if (pm_save_wakeup_count(val))
426 error = n;
427 else
428 pm_print_active_wakeup_sources();
429 }
430
431 out:
432 pm_autosleep_unlock();
433 return error;
434}
435
436power_attr(wakeup_count);
437
438#ifdef CONFIG_PM_AUTOSLEEP
439static ssize_t autosleep_show(struct kobject *kobj,
440 struct kobj_attribute *attr,
441 char *buf)
442{
443 suspend_state_t state = pm_autosleep_state();
444
445 if (state == PM_SUSPEND_ON)
446 return sprintf(buf, "off\n");
447
448#ifdef CONFIG_SUSPEND
449 if (state < PM_SUSPEND_MAX)
450 return sprintf(buf, "%s\n", valid_state(state) ?
451 pm_states[state] : "error");
452#endif
453#ifdef CONFIG_HIBERNATION
454 return sprintf(buf, "disk\n");
455#else
456 return sprintf(buf, "error");
457#endif
458}
459
460static ssize_t autosleep_store(struct kobject *kobj,
461 struct kobj_attribute *attr,
462 const char *buf, size_t n)
463{
464 suspend_state_t state = decode_state(buf, n);
465 int error;
466
467 if (state == PM_SUSPEND_ON
468 && strcmp(buf, "off") && strcmp(buf, "off\n"))
469 return -EINVAL;
470
471 error = pm_autosleep_set_state(state);
472 return error ? error : n;
473}
474
475power_attr(autosleep);
476#endif /* CONFIG_PM_AUTOSLEEP */
477
478#ifdef CONFIG_PM_WAKELOCKS
479static ssize_t wake_lock_show(struct kobject *kobj,
480 struct kobj_attribute *attr,
481 char *buf)
482{
483 return pm_show_wakelocks(buf, true);
484}
485
486static ssize_t wake_lock_store(struct kobject *kobj,
487 struct kobj_attribute *attr,
488 const char *buf, size_t n)
489{
490 int error = pm_wake_lock(buf);
491 return error ? error : n;
492}
493
494power_attr(wake_lock);
495
496static ssize_t wake_unlock_show(struct kobject *kobj,
497 struct kobj_attribute *attr,
498 char *buf)
499{
500 return pm_show_wakelocks(buf, false);
501}
502
503static ssize_t wake_unlock_store(struct kobject *kobj,
504 struct kobj_attribute *attr,
505 const char *buf, size_t n)
506{
507 int error = pm_wake_unlock(buf);
508 return error ? error : n;
509}
510
511power_attr(wake_unlock);
512
513#endif /* CONFIG_PM_WAKELOCKS */
514#endif /* CONFIG_PM_SLEEP */
515
516#ifdef CONFIG_PM_TRACE
517int pm_trace_enabled;
518
519static ssize_t pm_trace_show(struct kobject *kobj, struct kobj_attribute *attr,
520 char *buf)
521{
522 return sprintf(buf, "%d\n", pm_trace_enabled);
523}
524
525static ssize_t
526pm_trace_store(struct kobject *kobj, struct kobj_attribute *attr,
527 const char *buf, size_t n)
528{
529 int val;
530
531 if (sscanf(buf, "%d", &val) == 1) {
532 pm_trace_enabled = !!val;
533 if (pm_trace_enabled) {
534 pr_warn("PM: Enabling pm_trace changes system date and time during resume.\n"
535 "PM: Correct system time has to be restored manually after resume.\n");
536 }
537 return n;
538 }
539 return -EINVAL;
540}
541
542power_attr(pm_trace);
543
544static ssize_t pm_trace_dev_match_show(struct kobject *kobj,
545 struct kobj_attribute *attr,
546 char *buf)
547{
548 return show_trace_dev_match(buf, PAGE_SIZE);
549}
550
551static ssize_t
552pm_trace_dev_match_store(struct kobject *kobj, struct kobj_attribute *attr,
553 const char *buf, size_t n)
554{
555 return -EINVAL;
556}
557
558power_attr(pm_trace_dev_match);
559
560#endif /* CONFIG_PM_TRACE */
561
562#ifdef CONFIG_FREEZER
563static ssize_t pm_freeze_timeout_show(struct kobject *kobj,
564 struct kobj_attribute *attr, char *buf)
565{
566 return sprintf(buf, "%u\n", freeze_timeout_msecs);
567}
568
569static ssize_t pm_freeze_timeout_store(struct kobject *kobj,
570 struct kobj_attribute *attr,
571 const char *buf, size_t n)
572{
573 unsigned long val;
574
575 if (kstrtoul(buf, 10, &val))
576 return -EINVAL;
577
578 freeze_timeout_msecs = val;
579 return n;
580}
581
582power_attr(pm_freeze_timeout);
583
584#endif /* CONFIG_FREEZER*/
585
586static struct attribute * g[] = {
587 &state_attr.attr,
588#ifdef CONFIG_PM_TRACE
589 &pm_trace_attr.attr,
590 &pm_trace_dev_match_attr.attr,
591#endif
592#ifdef CONFIG_PM_SLEEP
593 &pm_async_attr.attr,
594 &wakeup_count_attr.attr,
595#ifdef CONFIG_PM_AUTOSLEEP
596 &autosleep_attr.attr,
597#endif
598#ifdef CONFIG_PM_WAKELOCKS
599 &wake_lock_attr.attr,
600 &wake_unlock_attr.attr,
601#endif
602#ifdef CONFIG_PM_DEBUG
603 &pm_test_attr.attr,
604#endif
605#ifdef CONFIG_PM_SLEEP_DEBUG
606 &pm_print_times_attr.attr,
607#endif
608#endif
609#ifdef CONFIG_FREEZER
610 &pm_freeze_timeout_attr.attr,
611#endif
612 NULL,
613};
614
615static struct attribute_group attr_group = {
616 .attrs = g,
617};
618
619#ifdef CONFIG_PM_RUNTIME
620struct workqueue_struct *pm_wq;
621EXPORT_SYMBOL_GPL(pm_wq);
622
623static int __init pm_start_workqueue(void)
624{
625 pm_wq = alloc_workqueue("pm", WQ_FREEZABLE, 0);
626
627 return pm_wq ? 0 : -ENOMEM;
628}
629#else
630static inline int pm_start_workqueue(void) { return 0; }
631#endif
632
633static int __init pm_init(void)
634{
635 int error = pm_start_workqueue();
636 if (error)
637 return error;
638 hibernate_image_size_init();
639 hibernate_reserved_size_init();
640 power_kobj = kobject_create_and_add("power", NULL);
641 if (!power_kobj)
642 return -ENOMEM;
643 error = sysfs_create_group(power_kobj, &attr_group);
644 if (error)
645 return error;
646 pm_print_times_init();
647 return pm_autosleep_init();
648}
649
650core_initcall(pm_init);