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1/*
2 * drivers/base/power/wakeup.c - System wakeup events framework
3 *
4 * Copyright (c) 2010 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
5 *
6 * This file is released under the GPLv2.
7 */
8
9#include <linux/device.h>
10#include <linux/slab.h>
11#include <linux/sched.h>
12#include <linux/capability.h>
13#include <linux/suspend.h>
14#include <linux/seq_file.h>
15#include <linux/debugfs.h>
16
17#include "power.h"
18
19#define TIMEOUT 100
20
21/*
22 * If set, the suspend/hibernate code will abort transitions to a sleep state
23 * if wakeup events are registered during or immediately before the transition.
24 */
25bool events_check_enabled;
26
27/*
28 * Combined counters of registered wakeup events and wakeup events in progress.
29 * They need to be modified together atomically, so it's better to use one
30 * atomic variable to hold them both.
31 */
32static atomic_t combined_event_count = ATOMIC_INIT(0);
33
34#define IN_PROGRESS_BITS (sizeof(int) * 4)
35#define MAX_IN_PROGRESS ((1 << IN_PROGRESS_BITS) - 1)
36
37static void split_counters(unsigned int *cnt, unsigned int *inpr)
38{
39 unsigned int comb = atomic_read(&combined_event_count);
40
41 *cnt = (comb >> IN_PROGRESS_BITS);
42 *inpr = comb & MAX_IN_PROGRESS;
43}
44
45/* A preserved old value of the events counter. */
46static unsigned int saved_count;
47
48static DEFINE_SPINLOCK(events_lock);
49
50static void pm_wakeup_timer_fn(unsigned long data);
51
52static LIST_HEAD(wakeup_sources);
53
54/**
55 * wakeup_source_create - Create a struct wakeup_source object.
56 * @name: Name of the new wakeup source.
57 */
58struct wakeup_source *wakeup_source_create(const char *name)
59{
60 struct wakeup_source *ws;
61
62 ws = kzalloc(sizeof(*ws), GFP_KERNEL);
63 if (!ws)
64 return NULL;
65
66 spin_lock_init(&ws->lock);
67 if (name)
68 ws->name = kstrdup(name, GFP_KERNEL);
69
70 return ws;
71}
72EXPORT_SYMBOL_GPL(wakeup_source_create);
73
74/**
75 * wakeup_source_destroy - Destroy a struct wakeup_source object.
76 * @ws: Wakeup source to destroy.
77 */
78void wakeup_source_destroy(struct wakeup_source *ws)
79{
80 if (!ws)
81 return;
82
83 spin_lock_irq(&ws->lock);
84 while (ws->active) {
85 spin_unlock_irq(&ws->lock);
86
87 schedule_timeout_interruptible(msecs_to_jiffies(TIMEOUT));
88
89 spin_lock_irq(&ws->lock);
90 }
91 spin_unlock_irq(&ws->lock);
92
93 kfree(ws->name);
94 kfree(ws);
95}
96EXPORT_SYMBOL_GPL(wakeup_source_destroy);
97
98/**
99 * wakeup_source_add - Add given object to the list of wakeup sources.
100 * @ws: Wakeup source object to add to the list.
101 */
102void wakeup_source_add(struct wakeup_source *ws)
103{
104 if (WARN_ON(!ws))
105 return;
106
107 setup_timer(&ws->timer, pm_wakeup_timer_fn, (unsigned long)ws);
108 ws->active = false;
109
110 spin_lock_irq(&events_lock);
111 list_add_rcu(&ws->entry, &wakeup_sources);
112 spin_unlock_irq(&events_lock);
113}
114EXPORT_SYMBOL_GPL(wakeup_source_add);
115
116/**
117 * wakeup_source_remove - Remove given object from the wakeup sources list.
118 * @ws: Wakeup source object to remove from the list.
119 */
120void wakeup_source_remove(struct wakeup_source *ws)
121{
122 if (WARN_ON(!ws))
123 return;
124
125 spin_lock_irq(&events_lock);
126 list_del_rcu(&ws->entry);
127 spin_unlock_irq(&events_lock);
128 synchronize_rcu();
129}
130EXPORT_SYMBOL_GPL(wakeup_source_remove);
131
132/**
133 * wakeup_source_register - Create wakeup source and add it to the list.
134 * @name: Name of the wakeup source to register.
135 */
136struct wakeup_source *wakeup_source_register(const char *name)
137{
138 struct wakeup_source *ws;
139
140 ws = wakeup_source_create(name);
141 if (ws)
142 wakeup_source_add(ws);
143
144 return ws;
145}
146EXPORT_SYMBOL_GPL(wakeup_source_register);
147
148/**
149 * wakeup_source_unregister - Remove wakeup source from the list and remove it.
150 * @ws: Wakeup source object to unregister.
151 */
152void wakeup_source_unregister(struct wakeup_source *ws)
153{
154 wakeup_source_remove(ws);
155 wakeup_source_destroy(ws);
156}
157EXPORT_SYMBOL_GPL(wakeup_source_unregister);
158
159/**
160 * device_wakeup_attach - Attach a wakeup source object to a device object.
161 * @dev: Device to handle.
162 * @ws: Wakeup source object to attach to @dev.
163 *
164 * This causes @dev to be treated as a wakeup device.
165 */
166static int device_wakeup_attach(struct device *dev, struct wakeup_source *ws)
167{
168 spin_lock_irq(&dev->power.lock);
169 if (dev->power.wakeup) {
170 spin_unlock_irq(&dev->power.lock);
171 return -EEXIST;
172 }
173 dev->power.wakeup = ws;
174 spin_unlock_irq(&dev->power.lock);
175 return 0;
176}
177
178/**
179 * device_wakeup_enable - Enable given device to be a wakeup source.
180 * @dev: Device to handle.
181 *
182 * Create a wakeup source object, register it and attach it to @dev.
183 */
184int device_wakeup_enable(struct device *dev)
185{
186 struct wakeup_source *ws;
187 int ret;
188
189 if (!dev || !dev->power.can_wakeup)
190 return -EINVAL;
191
192 ws = wakeup_source_register(dev_name(dev));
193 if (!ws)
194 return -ENOMEM;
195
196 ret = device_wakeup_attach(dev, ws);
197 if (ret)
198 wakeup_source_unregister(ws);
199
200 return ret;
201}
202EXPORT_SYMBOL_GPL(device_wakeup_enable);
203
204/**
205 * device_wakeup_detach - Detach a device's wakeup source object from it.
206 * @dev: Device to detach the wakeup source object from.
207 *
208 * After it returns, @dev will not be treated as a wakeup device any more.
209 */
210static struct wakeup_source *device_wakeup_detach(struct device *dev)
211{
212 struct wakeup_source *ws;
213
214 spin_lock_irq(&dev->power.lock);
215 ws = dev->power.wakeup;
216 dev->power.wakeup = NULL;
217 spin_unlock_irq(&dev->power.lock);
218 return ws;
219}
220
221/**
222 * device_wakeup_disable - Do not regard a device as a wakeup source any more.
223 * @dev: Device to handle.
224 *
225 * Detach the @dev's wakeup source object from it, unregister this wakeup source
226 * object and destroy it.
227 */
228int device_wakeup_disable(struct device *dev)
229{
230 struct wakeup_source *ws;
231
232 if (!dev || !dev->power.can_wakeup)
233 return -EINVAL;
234
235 ws = device_wakeup_detach(dev);
236 if (ws)
237 wakeup_source_unregister(ws);
238
239 return 0;
240}
241EXPORT_SYMBOL_GPL(device_wakeup_disable);
242
243/**
244 * device_set_wakeup_capable - Set/reset device wakeup capability flag.
245 * @dev: Device to handle.
246 * @capable: Whether or not @dev is capable of waking up the system from sleep.
247 *
248 * If @capable is set, set the @dev's power.can_wakeup flag and add its
249 * wakeup-related attributes to sysfs. Otherwise, unset the @dev's
250 * power.can_wakeup flag and remove its wakeup-related attributes from sysfs.
251 *
252 * This function may sleep and it can't be called from any context where
253 * sleeping is not allowed.
254 */
255void device_set_wakeup_capable(struct device *dev, bool capable)
256{
257 if (!!dev->power.can_wakeup == !!capable)
258 return;
259
260 if (device_is_registered(dev) && !list_empty(&dev->power.entry)) {
261 if (capable) {
262 if (wakeup_sysfs_add(dev))
263 return;
264 } else {
265 wakeup_sysfs_remove(dev);
266 }
267 }
268 dev->power.can_wakeup = capable;
269}
270EXPORT_SYMBOL_GPL(device_set_wakeup_capable);
271
272/**
273 * device_init_wakeup - Device wakeup initialization.
274 * @dev: Device to handle.
275 * @enable: Whether or not to enable @dev as a wakeup device.
276 *
277 * By default, most devices should leave wakeup disabled. The exceptions are
278 * devices that everyone expects to be wakeup sources: keyboards, power buttons,
279 * possibly network interfaces, etc.
280 */
281int device_init_wakeup(struct device *dev, bool enable)
282{
283 int ret = 0;
284
285 if (enable) {
286 device_set_wakeup_capable(dev, true);
287 ret = device_wakeup_enable(dev);
288 } else {
289 device_set_wakeup_capable(dev, false);
290 }
291
292 return ret;
293}
294EXPORT_SYMBOL_GPL(device_init_wakeup);
295
296/**
297 * device_set_wakeup_enable - Enable or disable a device to wake up the system.
298 * @dev: Device to handle.
299 */
300int device_set_wakeup_enable(struct device *dev, bool enable)
301{
302 if (!dev || !dev->power.can_wakeup)
303 return -EINVAL;
304
305 return enable ? device_wakeup_enable(dev) : device_wakeup_disable(dev);
306}
307EXPORT_SYMBOL_GPL(device_set_wakeup_enable);
308
309/*
310 * The functions below use the observation that each wakeup event starts a
311 * period in which the system should not be suspended. The moment this period
312 * will end depends on how the wakeup event is going to be processed after being
313 * detected and all of the possible cases can be divided into two distinct
314 * groups.
315 *
316 * First, a wakeup event may be detected by the same functional unit that will
317 * carry out the entire processing of it and possibly will pass it to user space
318 * for further processing. In that case the functional unit that has detected
319 * the event may later "close" the "no suspend" period associated with it
320 * directly as soon as it has been dealt with. The pair of pm_stay_awake() and
321 * pm_relax(), balanced with each other, is supposed to be used in such
322 * situations.
323 *
324 * Second, a wakeup event may be detected by one functional unit and processed
325 * by another one. In that case the unit that has detected it cannot really
326 * "close" the "no suspend" period associated with it, unless it knows in
327 * advance what's going to happen to the event during processing. This
328 * knowledge, however, may not be available to it, so it can simply specify time
329 * to wait before the system can be suspended and pass it as the second
330 * argument of pm_wakeup_event().
331 *
332 * It is valid to call pm_relax() after pm_wakeup_event(), in which case the
333 * "no suspend" period will be ended either by the pm_relax(), or by the timer
334 * function executed when the timer expires, whichever comes first.
335 */
336
337/**
338 * wakup_source_activate - Mark given wakeup source as active.
339 * @ws: Wakeup source to handle.
340 *
341 * Update the @ws' statistics and, if @ws has just been activated, notify the PM
342 * core of the event by incrementing the counter of of wakeup events being
343 * processed.
344 */
345static void wakeup_source_activate(struct wakeup_source *ws)
346{
347 ws->active = true;
348 ws->active_count++;
349 ws->timer_expires = jiffies;
350 ws->last_time = ktime_get();
351
352 /* Increment the counter of events in progress. */
353 atomic_inc(&combined_event_count);
354}
355
356/**
357 * __pm_stay_awake - Notify the PM core of a wakeup event.
358 * @ws: Wakeup source object associated with the source of the event.
359 *
360 * It is safe to call this function from interrupt context.
361 */
362void __pm_stay_awake(struct wakeup_source *ws)
363{
364 unsigned long flags;
365
366 if (!ws)
367 return;
368
369 spin_lock_irqsave(&ws->lock, flags);
370 ws->event_count++;
371 if (!ws->active)
372 wakeup_source_activate(ws);
373 spin_unlock_irqrestore(&ws->lock, flags);
374}
375EXPORT_SYMBOL_GPL(__pm_stay_awake);
376
377/**
378 * pm_stay_awake - Notify the PM core that a wakeup event is being processed.
379 * @dev: Device the wakeup event is related to.
380 *
381 * Notify the PM core of a wakeup event (signaled by @dev) by calling
382 * __pm_stay_awake for the @dev's wakeup source object.
383 *
384 * Call this function after detecting of a wakeup event if pm_relax() is going
385 * to be called directly after processing the event (and possibly passing it to
386 * user space for further processing).
387 */
388void pm_stay_awake(struct device *dev)
389{
390 unsigned long flags;
391
392 if (!dev)
393 return;
394
395 spin_lock_irqsave(&dev->power.lock, flags);
396 __pm_stay_awake(dev->power.wakeup);
397 spin_unlock_irqrestore(&dev->power.lock, flags);
398}
399EXPORT_SYMBOL_GPL(pm_stay_awake);
400
401/**
402 * wakup_source_deactivate - Mark given wakeup source as inactive.
403 * @ws: Wakeup source to handle.
404 *
405 * Update the @ws' statistics and notify the PM core that the wakeup source has
406 * become inactive by decrementing the counter of wakeup events being processed
407 * and incrementing the counter of registered wakeup events.
408 */
409static void wakeup_source_deactivate(struct wakeup_source *ws)
410{
411 ktime_t duration;
412 ktime_t now;
413
414 ws->relax_count++;
415 /*
416 * __pm_relax() may be called directly or from a timer function.
417 * If it is called directly right after the timer function has been
418 * started, but before the timer function calls __pm_relax(), it is
419 * possible that __pm_stay_awake() will be called in the meantime and
420 * will set ws->active. Then, ws->active may be cleared immediately
421 * by the __pm_relax() called from the timer function, but in such a
422 * case ws->relax_count will be different from ws->active_count.
423 */
424 if (ws->relax_count != ws->active_count) {
425 ws->relax_count--;
426 return;
427 }
428
429 ws->active = false;
430
431 now = ktime_get();
432 duration = ktime_sub(now, ws->last_time);
433 ws->total_time = ktime_add(ws->total_time, duration);
434 if (ktime_to_ns(duration) > ktime_to_ns(ws->max_time))
435 ws->max_time = duration;
436
437 del_timer(&ws->timer);
438
439 /*
440 * Increment the counter of registered wakeup events and decrement the
441 * couter of wakeup events in progress simultaneously.
442 */
443 atomic_add(MAX_IN_PROGRESS, &combined_event_count);
444}
445
446/**
447 * __pm_relax - Notify the PM core that processing of a wakeup event has ended.
448 * @ws: Wakeup source object associated with the source of the event.
449 *
450 * Call this function for wakeup events whose processing started with calling
451 * __pm_stay_awake().
452 *
453 * It is safe to call it from interrupt context.
454 */
455void __pm_relax(struct wakeup_source *ws)
456{
457 unsigned long flags;
458
459 if (!ws)
460 return;
461
462 spin_lock_irqsave(&ws->lock, flags);
463 if (ws->active)
464 wakeup_source_deactivate(ws);
465 spin_unlock_irqrestore(&ws->lock, flags);
466}
467EXPORT_SYMBOL_GPL(__pm_relax);
468
469/**
470 * pm_relax - Notify the PM core that processing of a wakeup event has ended.
471 * @dev: Device that signaled the event.
472 *
473 * Execute __pm_relax() for the @dev's wakeup source object.
474 */
475void pm_relax(struct device *dev)
476{
477 unsigned long flags;
478
479 if (!dev)
480 return;
481
482 spin_lock_irqsave(&dev->power.lock, flags);
483 __pm_relax(dev->power.wakeup);
484 spin_unlock_irqrestore(&dev->power.lock, flags);
485}
486EXPORT_SYMBOL_GPL(pm_relax);
487
488/**
489 * pm_wakeup_timer_fn - Delayed finalization of a wakeup event.
490 * @data: Address of the wakeup source object associated with the event source.
491 *
492 * Call __pm_relax() for the wakeup source whose address is stored in @data.
493 */
494static void pm_wakeup_timer_fn(unsigned long data)
495{
496 __pm_relax((struct wakeup_source *)data);
497}
498
499/**
500 * __pm_wakeup_event - Notify the PM core of a wakeup event.
501 * @ws: Wakeup source object associated with the event source.
502 * @msec: Anticipated event processing time (in milliseconds).
503 *
504 * Notify the PM core of a wakeup event whose source is @ws that will take
505 * approximately @msec milliseconds to be processed by the kernel. If @ws is
506 * not active, activate it. If @msec is nonzero, set up the @ws' timer to
507 * execute pm_wakeup_timer_fn() in future.
508 *
509 * It is safe to call this function from interrupt context.
510 */
511void __pm_wakeup_event(struct wakeup_source *ws, unsigned int msec)
512{
513 unsigned long flags;
514 unsigned long expires;
515
516 if (!ws)
517 return;
518
519 spin_lock_irqsave(&ws->lock, flags);
520
521 ws->event_count++;
522 if (!ws->active)
523 wakeup_source_activate(ws);
524
525 if (!msec) {
526 wakeup_source_deactivate(ws);
527 goto unlock;
528 }
529
530 expires = jiffies + msecs_to_jiffies(msec);
531 if (!expires)
532 expires = 1;
533
534 if (time_after(expires, ws->timer_expires)) {
535 mod_timer(&ws->timer, expires);
536 ws->timer_expires = expires;
537 }
538
539 unlock:
540 spin_unlock_irqrestore(&ws->lock, flags);
541}
542EXPORT_SYMBOL_GPL(__pm_wakeup_event);
543
544
545/**
546 * pm_wakeup_event - Notify the PM core of a wakeup event.
547 * @dev: Device the wakeup event is related to.
548 * @msec: Anticipated event processing time (in milliseconds).
549 *
550 * Call __pm_wakeup_event() for the @dev's wakeup source object.
551 */
552void pm_wakeup_event(struct device *dev, unsigned int msec)
553{
554 unsigned long flags;
555
556 if (!dev)
557 return;
558
559 spin_lock_irqsave(&dev->power.lock, flags);
560 __pm_wakeup_event(dev->power.wakeup, msec);
561 spin_unlock_irqrestore(&dev->power.lock, flags);
562}
563EXPORT_SYMBOL_GPL(pm_wakeup_event);
564
565/**
566 * pm_wakeup_update_hit_counts - Update hit counts of all active wakeup sources.
567 */
568static void pm_wakeup_update_hit_counts(void)
569{
570 unsigned long flags;
571 struct wakeup_source *ws;
572
573 rcu_read_lock();
574 list_for_each_entry_rcu(ws, &wakeup_sources, entry) {
575 spin_lock_irqsave(&ws->lock, flags);
576 if (ws->active)
577 ws->hit_count++;
578 spin_unlock_irqrestore(&ws->lock, flags);
579 }
580 rcu_read_unlock();
581}
582
583/**
584 * pm_wakeup_pending - Check if power transition in progress should be aborted.
585 *
586 * Compare the current number of registered wakeup events with its preserved
587 * value from the past and return true if new wakeup events have been registered
588 * since the old value was stored. Also return true if the current number of
589 * wakeup events being processed is different from zero.
590 */
591bool pm_wakeup_pending(void)
592{
593 unsigned long flags;
594 bool ret = false;
595
596 spin_lock_irqsave(&events_lock, flags);
597 if (events_check_enabled) {
598 unsigned int cnt, inpr;
599
600 split_counters(&cnt, &inpr);
601 ret = (cnt != saved_count || inpr > 0);
602 events_check_enabled = !ret;
603 }
604 spin_unlock_irqrestore(&events_lock, flags);
605 if (ret)
606 pm_wakeup_update_hit_counts();
607 return ret;
608}
609
610/**
611 * pm_get_wakeup_count - Read the number of registered wakeup events.
612 * @count: Address to store the value at.
613 *
614 * Store the number of registered wakeup events at the address in @count. Block
615 * if the current number of wakeup events being processed is nonzero.
616 *
617 * Return 'false' if the wait for the number of wakeup events being processed to
618 * drop down to zero has been interrupted by a signal (and the current number
619 * of wakeup events being processed is still nonzero). Otherwise return 'true'.
620 */
621bool pm_get_wakeup_count(unsigned int *count)
622{
623 unsigned int cnt, inpr;
624
625 for (;;) {
626 split_counters(&cnt, &inpr);
627 if (inpr == 0 || signal_pending(current))
628 break;
629 pm_wakeup_update_hit_counts();
630 schedule_timeout_interruptible(msecs_to_jiffies(TIMEOUT));
631 }
632
633 split_counters(&cnt, &inpr);
634 *count = cnt;
635 return !inpr;
636}
637
638/**
639 * pm_save_wakeup_count - Save the current number of registered wakeup events.
640 * @count: Value to compare with the current number of registered wakeup events.
641 *
642 * If @count is equal to the current number of registered wakeup events and the
643 * current number of wakeup events being processed is zero, store @count as the
644 * old number of registered wakeup events for pm_check_wakeup_events(), enable
645 * wakeup events detection and return 'true'. Otherwise disable wakeup events
646 * detection and return 'false'.
647 */
648bool pm_save_wakeup_count(unsigned int count)
649{
650 unsigned int cnt, inpr;
651
652 events_check_enabled = false;
653 spin_lock_irq(&events_lock);
654 split_counters(&cnt, &inpr);
655 if (cnt == count && inpr == 0) {
656 saved_count = count;
657 events_check_enabled = true;
658 }
659 spin_unlock_irq(&events_lock);
660 if (!events_check_enabled)
661 pm_wakeup_update_hit_counts();
662 return events_check_enabled;
663}
664
665static struct dentry *wakeup_sources_stats_dentry;
666
667/**
668 * print_wakeup_source_stats - Print wakeup source statistics information.
669 * @m: seq_file to print the statistics into.
670 * @ws: Wakeup source object to print the statistics for.
671 */
672static int print_wakeup_source_stats(struct seq_file *m,
673 struct wakeup_source *ws)
674{
675 unsigned long flags;
676 ktime_t total_time;
677 ktime_t max_time;
678 unsigned long active_count;
679 ktime_t active_time;
680 int ret;
681
682 spin_lock_irqsave(&ws->lock, flags);
683
684 total_time = ws->total_time;
685 max_time = ws->max_time;
686 active_count = ws->active_count;
687 if (ws->active) {
688 active_time = ktime_sub(ktime_get(), ws->last_time);
689 total_time = ktime_add(total_time, active_time);
690 if (active_time.tv64 > max_time.tv64)
691 max_time = active_time;
692 } else {
693 active_time = ktime_set(0, 0);
694 }
695
696 ret = seq_printf(m, "%-12s\t%lu\t\t%lu\t\t%lu\t\t"
697 "%lld\t\t%lld\t\t%lld\t\t%lld\n",
698 ws->name, active_count, ws->event_count, ws->hit_count,
699 ktime_to_ms(active_time), ktime_to_ms(total_time),
700 ktime_to_ms(max_time), ktime_to_ms(ws->last_time));
701
702 spin_unlock_irqrestore(&ws->lock, flags);
703
704 return ret;
705}
706
707/**
708 * wakeup_sources_stats_show - Print wakeup sources statistics information.
709 * @m: seq_file to print the statistics into.
710 */
711static int wakeup_sources_stats_show(struct seq_file *m, void *unused)
712{
713 struct wakeup_source *ws;
714
715 seq_puts(m, "name\t\tactive_count\tevent_count\thit_count\t"
716 "active_since\ttotal_time\tmax_time\tlast_change\n");
717
718 rcu_read_lock();
719 list_for_each_entry_rcu(ws, &wakeup_sources, entry)
720 print_wakeup_source_stats(m, ws);
721 rcu_read_unlock();
722
723 return 0;
724}
725
726static int wakeup_sources_stats_open(struct inode *inode, struct file *file)
727{
728 return single_open(file, wakeup_sources_stats_show, NULL);
729}
730
731static const struct file_operations wakeup_sources_stats_fops = {
732 .owner = THIS_MODULE,
733 .open = wakeup_sources_stats_open,
734 .read = seq_read,
735 .llseek = seq_lseek,
736 .release = single_release,
737};
738
739static int __init wakeup_sources_debugfs_init(void)
740{
741 wakeup_sources_stats_dentry = debugfs_create_file("wakeup_sources",
742 S_IRUGO, NULL, NULL, &wakeup_sources_stats_fops);
743 return 0;
744}
745
746postcore_initcall(wakeup_sources_debugfs_init);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * drivers/base/power/wakeup.c - System wakeup events framework
4 *
5 * Copyright (c) 2010 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
6 */
7#define pr_fmt(fmt) "PM: " fmt
8
9#include <linux/device.h>
10#include <linux/slab.h>
11#include <linux/sched/signal.h>
12#include <linux/capability.h>
13#include <linux/export.h>
14#include <linux/suspend.h>
15#include <linux/seq_file.h>
16#include <linux/debugfs.h>
17#include <linux/pm_wakeirq.h>
18#include <trace/events/power.h>
19
20#include "power.h"
21
22#ifndef CONFIG_SUSPEND
23suspend_state_t pm_suspend_target_state;
24#define pm_suspend_target_state (PM_SUSPEND_ON)
25#endif
26
27#define list_for_each_entry_rcu_locked(pos, head, member) \
28 list_for_each_entry_rcu(pos, head, member, \
29 srcu_read_lock_held(&wakeup_srcu))
30/*
31 * If set, the suspend/hibernate code will abort transitions to a sleep state
32 * if wakeup events are registered during or immediately before the transition.
33 */
34bool events_check_enabled __read_mostly;
35
36/* First wakeup IRQ seen by the kernel in the last cycle. */
37static unsigned int wakeup_irq[2] __read_mostly;
38static DEFINE_RAW_SPINLOCK(wakeup_irq_lock);
39
40/* If greater than 0 and the system is suspending, terminate the suspend. */
41static atomic_t pm_abort_suspend __read_mostly;
42
43/*
44 * Combined counters of registered wakeup events and wakeup events in progress.
45 * They need to be modified together atomically, so it's better to use one
46 * atomic variable to hold them both.
47 */
48static atomic_t combined_event_count = ATOMIC_INIT(0);
49
50#define IN_PROGRESS_BITS (sizeof(int) * 4)
51#define MAX_IN_PROGRESS ((1 << IN_PROGRESS_BITS) - 1)
52
53static void split_counters(unsigned int *cnt, unsigned int *inpr)
54{
55 unsigned int comb = atomic_read(&combined_event_count);
56
57 *cnt = (comb >> IN_PROGRESS_BITS);
58 *inpr = comb & MAX_IN_PROGRESS;
59}
60
61/* A preserved old value of the events counter. */
62static unsigned int saved_count;
63
64static DEFINE_RAW_SPINLOCK(events_lock);
65
66static void pm_wakeup_timer_fn(struct timer_list *t);
67
68static LIST_HEAD(wakeup_sources);
69
70static DECLARE_WAIT_QUEUE_HEAD(wakeup_count_wait_queue);
71
72DEFINE_STATIC_SRCU(wakeup_srcu);
73
74static struct wakeup_source deleted_ws = {
75 .name = "deleted",
76 .lock = __SPIN_LOCK_UNLOCKED(deleted_ws.lock),
77};
78
79static DEFINE_IDA(wakeup_ida);
80
81/**
82 * wakeup_source_create - Create a struct wakeup_source object.
83 * @name: Name of the new wakeup source.
84 */
85struct wakeup_source *wakeup_source_create(const char *name)
86{
87 struct wakeup_source *ws;
88 const char *ws_name;
89 int id;
90
91 ws = kzalloc(sizeof(*ws), GFP_KERNEL);
92 if (!ws)
93 goto err_ws;
94
95 ws_name = kstrdup_const(name, GFP_KERNEL);
96 if (!ws_name)
97 goto err_name;
98 ws->name = ws_name;
99
100 id = ida_alloc(&wakeup_ida, GFP_KERNEL);
101 if (id < 0)
102 goto err_id;
103 ws->id = id;
104
105 return ws;
106
107err_id:
108 kfree_const(ws->name);
109err_name:
110 kfree(ws);
111err_ws:
112 return NULL;
113}
114EXPORT_SYMBOL_GPL(wakeup_source_create);
115
116/*
117 * Record wakeup_source statistics being deleted into a dummy wakeup_source.
118 */
119static void wakeup_source_record(struct wakeup_source *ws)
120{
121 unsigned long flags;
122
123 spin_lock_irqsave(&deleted_ws.lock, flags);
124
125 if (ws->event_count) {
126 deleted_ws.total_time =
127 ktime_add(deleted_ws.total_time, ws->total_time);
128 deleted_ws.prevent_sleep_time =
129 ktime_add(deleted_ws.prevent_sleep_time,
130 ws->prevent_sleep_time);
131 deleted_ws.max_time =
132 ktime_compare(deleted_ws.max_time, ws->max_time) > 0 ?
133 deleted_ws.max_time : ws->max_time;
134 deleted_ws.event_count += ws->event_count;
135 deleted_ws.active_count += ws->active_count;
136 deleted_ws.relax_count += ws->relax_count;
137 deleted_ws.expire_count += ws->expire_count;
138 deleted_ws.wakeup_count += ws->wakeup_count;
139 }
140
141 spin_unlock_irqrestore(&deleted_ws.lock, flags);
142}
143
144static void wakeup_source_free(struct wakeup_source *ws)
145{
146 ida_free(&wakeup_ida, ws->id);
147 kfree_const(ws->name);
148 kfree(ws);
149}
150
151/**
152 * wakeup_source_destroy - Destroy a struct wakeup_source object.
153 * @ws: Wakeup source to destroy.
154 *
155 * Use only for wakeup source objects created with wakeup_source_create().
156 */
157void wakeup_source_destroy(struct wakeup_source *ws)
158{
159 if (!ws)
160 return;
161
162 __pm_relax(ws);
163 wakeup_source_record(ws);
164 wakeup_source_free(ws);
165}
166EXPORT_SYMBOL_GPL(wakeup_source_destroy);
167
168/**
169 * wakeup_source_add - Add given object to the list of wakeup sources.
170 * @ws: Wakeup source object to add to the list.
171 */
172void wakeup_source_add(struct wakeup_source *ws)
173{
174 unsigned long flags;
175
176 if (WARN_ON(!ws))
177 return;
178
179 spin_lock_init(&ws->lock);
180 timer_setup(&ws->timer, pm_wakeup_timer_fn, 0);
181 ws->active = false;
182
183 raw_spin_lock_irqsave(&events_lock, flags);
184 list_add_rcu(&ws->entry, &wakeup_sources);
185 raw_spin_unlock_irqrestore(&events_lock, flags);
186}
187EXPORT_SYMBOL_GPL(wakeup_source_add);
188
189/**
190 * wakeup_source_remove - Remove given object from the wakeup sources list.
191 * @ws: Wakeup source object to remove from the list.
192 */
193void wakeup_source_remove(struct wakeup_source *ws)
194{
195 unsigned long flags;
196
197 if (WARN_ON(!ws))
198 return;
199
200 raw_spin_lock_irqsave(&events_lock, flags);
201 list_del_rcu(&ws->entry);
202 raw_spin_unlock_irqrestore(&events_lock, flags);
203 synchronize_srcu(&wakeup_srcu);
204
205 del_timer_sync(&ws->timer);
206 /*
207 * Clear timer.function to make wakeup_source_not_registered() treat
208 * this wakeup source as not registered.
209 */
210 ws->timer.function = NULL;
211}
212EXPORT_SYMBOL_GPL(wakeup_source_remove);
213
214/**
215 * wakeup_source_register - Create wakeup source and add it to the list.
216 * @dev: Device this wakeup source is associated with (or NULL if virtual).
217 * @name: Name of the wakeup source to register.
218 */
219struct wakeup_source *wakeup_source_register(struct device *dev,
220 const char *name)
221{
222 struct wakeup_source *ws;
223 int ret;
224
225 ws = wakeup_source_create(name);
226 if (ws) {
227 if (!dev || device_is_registered(dev)) {
228 ret = wakeup_source_sysfs_add(dev, ws);
229 if (ret) {
230 wakeup_source_free(ws);
231 return NULL;
232 }
233 }
234 wakeup_source_add(ws);
235 }
236 return ws;
237}
238EXPORT_SYMBOL_GPL(wakeup_source_register);
239
240/**
241 * wakeup_source_unregister - Remove wakeup source from the list and remove it.
242 * @ws: Wakeup source object to unregister.
243 */
244void wakeup_source_unregister(struct wakeup_source *ws)
245{
246 if (ws) {
247 wakeup_source_remove(ws);
248 if (ws->dev)
249 wakeup_source_sysfs_remove(ws);
250
251 wakeup_source_destroy(ws);
252 }
253}
254EXPORT_SYMBOL_GPL(wakeup_source_unregister);
255
256/**
257 * wakeup_sources_read_lock - Lock wakeup source list for read.
258 *
259 * Returns an index of srcu lock for struct wakeup_srcu.
260 * This index must be passed to the matching wakeup_sources_read_unlock().
261 */
262int wakeup_sources_read_lock(void)
263{
264 return srcu_read_lock(&wakeup_srcu);
265}
266EXPORT_SYMBOL_GPL(wakeup_sources_read_lock);
267
268/**
269 * wakeup_sources_read_unlock - Unlock wakeup source list.
270 * @idx: return value from corresponding wakeup_sources_read_lock()
271 */
272void wakeup_sources_read_unlock(int idx)
273{
274 srcu_read_unlock(&wakeup_srcu, idx);
275}
276EXPORT_SYMBOL_GPL(wakeup_sources_read_unlock);
277
278/**
279 * wakeup_sources_walk_start - Begin a walk on wakeup source list
280 *
281 * Returns first object of the list of wakeup sources.
282 *
283 * Note that to be safe, wakeup sources list needs to be locked by calling
284 * wakeup_source_read_lock() for this.
285 */
286struct wakeup_source *wakeup_sources_walk_start(void)
287{
288 struct list_head *ws_head = &wakeup_sources;
289
290 return list_entry_rcu(ws_head->next, struct wakeup_source, entry);
291}
292EXPORT_SYMBOL_GPL(wakeup_sources_walk_start);
293
294/**
295 * wakeup_sources_walk_next - Get next wakeup source from the list
296 * @ws: Previous wakeup source object
297 *
298 * Note that to be safe, wakeup sources list needs to be locked by calling
299 * wakeup_source_read_lock() for this.
300 */
301struct wakeup_source *wakeup_sources_walk_next(struct wakeup_source *ws)
302{
303 struct list_head *ws_head = &wakeup_sources;
304
305 return list_next_or_null_rcu(ws_head, &ws->entry,
306 struct wakeup_source, entry);
307}
308EXPORT_SYMBOL_GPL(wakeup_sources_walk_next);
309
310/**
311 * device_wakeup_attach - Attach a wakeup source object to a device object.
312 * @dev: Device to handle.
313 * @ws: Wakeup source object to attach to @dev.
314 *
315 * This causes @dev to be treated as a wakeup device.
316 */
317static int device_wakeup_attach(struct device *dev, struct wakeup_source *ws)
318{
319 spin_lock_irq(&dev->power.lock);
320 if (dev->power.wakeup) {
321 spin_unlock_irq(&dev->power.lock);
322 return -EEXIST;
323 }
324 dev->power.wakeup = ws;
325 if (dev->power.wakeirq)
326 device_wakeup_attach_irq(dev, dev->power.wakeirq);
327 spin_unlock_irq(&dev->power.lock);
328 return 0;
329}
330
331/**
332 * device_wakeup_enable - Enable given device to be a wakeup source.
333 * @dev: Device to handle.
334 *
335 * Create a wakeup source object, register it and attach it to @dev.
336 */
337int device_wakeup_enable(struct device *dev)
338{
339 struct wakeup_source *ws;
340 int ret;
341
342 if (!dev || !dev->power.can_wakeup)
343 return -EINVAL;
344
345 if (pm_suspend_target_state != PM_SUSPEND_ON)
346 dev_dbg(dev, "Suspicious %s() during system transition!\n", __func__);
347
348 ws = wakeup_source_register(dev, dev_name(dev));
349 if (!ws)
350 return -ENOMEM;
351
352 ret = device_wakeup_attach(dev, ws);
353 if (ret)
354 wakeup_source_unregister(ws);
355
356 return ret;
357}
358EXPORT_SYMBOL_GPL(device_wakeup_enable);
359
360/**
361 * device_wakeup_attach_irq - Attach a wakeirq to a wakeup source
362 * @dev: Device to handle
363 * @wakeirq: Device specific wakeirq entry
364 *
365 * Attach a device wakeirq to the wakeup source so the device
366 * wake IRQ can be configured automatically for suspend and
367 * resume.
368 *
369 * Call under the device's power.lock lock.
370 */
371void device_wakeup_attach_irq(struct device *dev,
372 struct wake_irq *wakeirq)
373{
374 struct wakeup_source *ws;
375
376 ws = dev->power.wakeup;
377 if (!ws)
378 return;
379
380 if (ws->wakeirq)
381 dev_err(dev, "Leftover wakeup IRQ found, overriding\n");
382
383 ws->wakeirq = wakeirq;
384}
385
386/**
387 * device_wakeup_detach_irq - Detach a wakeirq from a wakeup source
388 * @dev: Device to handle
389 *
390 * Removes a device wakeirq from the wakeup source.
391 *
392 * Call under the device's power.lock lock.
393 */
394void device_wakeup_detach_irq(struct device *dev)
395{
396 struct wakeup_source *ws;
397
398 ws = dev->power.wakeup;
399 if (ws)
400 ws->wakeirq = NULL;
401}
402
403/**
404 * device_wakeup_arm_wake_irqs -
405 *
406 * Iterates over the list of device wakeirqs to arm them.
407 */
408void device_wakeup_arm_wake_irqs(void)
409{
410 struct wakeup_source *ws;
411 int srcuidx;
412
413 srcuidx = srcu_read_lock(&wakeup_srcu);
414 list_for_each_entry_rcu_locked(ws, &wakeup_sources, entry)
415 dev_pm_arm_wake_irq(ws->wakeirq);
416 srcu_read_unlock(&wakeup_srcu, srcuidx);
417}
418
419/**
420 * device_wakeup_disarm_wake_irqs -
421 *
422 * Iterates over the list of device wakeirqs to disarm them.
423 */
424void device_wakeup_disarm_wake_irqs(void)
425{
426 struct wakeup_source *ws;
427 int srcuidx;
428
429 srcuidx = srcu_read_lock(&wakeup_srcu);
430 list_for_each_entry_rcu_locked(ws, &wakeup_sources, entry)
431 dev_pm_disarm_wake_irq(ws->wakeirq);
432 srcu_read_unlock(&wakeup_srcu, srcuidx);
433}
434
435/**
436 * device_wakeup_detach - Detach a device's wakeup source object from it.
437 * @dev: Device to detach the wakeup source object from.
438 *
439 * After it returns, @dev will not be treated as a wakeup device any more.
440 */
441static struct wakeup_source *device_wakeup_detach(struct device *dev)
442{
443 struct wakeup_source *ws;
444
445 spin_lock_irq(&dev->power.lock);
446 ws = dev->power.wakeup;
447 dev->power.wakeup = NULL;
448 spin_unlock_irq(&dev->power.lock);
449 return ws;
450}
451
452/**
453 * device_wakeup_disable - Do not regard a device as a wakeup source any more.
454 * @dev: Device to handle.
455 *
456 * Detach the @dev's wakeup source object from it, unregister this wakeup source
457 * object and destroy it.
458 */
459int device_wakeup_disable(struct device *dev)
460{
461 struct wakeup_source *ws;
462
463 if (!dev || !dev->power.can_wakeup)
464 return -EINVAL;
465
466 ws = device_wakeup_detach(dev);
467 wakeup_source_unregister(ws);
468 return 0;
469}
470EXPORT_SYMBOL_GPL(device_wakeup_disable);
471
472/**
473 * device_set_wakeup_capable - Set/reset device wakeup capability flag.
474 * @dev: Device to handle.
475 * @capable: Whether or not @dev is capable of waking up the system from sleep.
476 *
477 * If @capable is set, set the @dev's power.can_wakeup flag and add its
478 * wakeup-related attributes to sysfs. Otherwise, unset the @dev's
479 * power.can_wakeup flag and remove its wakeup-related attributes from sysfs.
480 *
481 * This function may sleep and it can't be called from any context where
482 * sleeping is not allowed.
483 */
484void device_set_wakeup_capable(struct device *dev, bool capable)
485{
486 if (!!dev->power.can_wakeup == !!capable)
487 return;
488
489 dev->power.can_wakeup = capable;
490 if (device_is_registered(dev) && !list_empty(&dev->power.entry)) {
491 if (capable) {
492 int ret = wakeup_sysfs_add(dev);
493
494 if (ret)
495 dev_info(dev, "Wakeup sysfs attributes not added\n");
496 } else {
497 wakeup_sysfs_remove(dev);
498 }
499 }
500}
501EXPORT_SYMBOL_GPL(device_set_wakeup_capable);
502
503/**
504 * device_set_wakeup_enable - Enable or disable a device to wake up the system.
505 * @dev: Device to handle.
506 * @enable: enable/disable flag
507 */
508int device_set_wakeup_enable(struct device *dev, bool enable)
509{
510 return enable ? device_wakeup_enable(dev) : device_wakeup_disable(dev);
511}
512EXPORT_SYMBOL_GPL(device_set_wakeup_enable);
513
514/**
515 * wakeup_source_not_registered - validate the given wakeup source.
516 * @ws: Wakeup source to be validated.
517 */
518static bool wakeup_source_not_registered(struct wakeup_source *ws)
519{
520 /*
521 * Use timer struct to check if the given source is initialized
522 * by wakeup_source_add.
523 */
524 return ws->timer.function != pm_wakeup_timer_fn;
525}
526
527/*
528 * The functions below use the observation that each wakeup event starts a
529 * period in which the system should not be suspended. The moment this period
530 * will end depends on how the wakeup event is going to be processed after being
531 * detected and all of the possible cases can be divided into two distinct
532 * groups.
533 *
534 * First, a wakeup event may be detected by the same functional unit that will
535 * carry out the entire processing of it and possibly will pass it to user space
536 * for further processing. In that case the functional unit that has detected
537 * the event may later "close" the "no suspend" period associated with it
538 * directly as soon as it has been dealt with. The pair of pm_stay_awake() and
539 * pm_relax(), balanced with each other, is supposed to be used in such
540 * situations.
541 *
542 * Second, a wakeup event may be detected by one functional unit and processed
543 * by another one. In that case the unit that has detected it cannot really
544 * "close" the "no suspend" period associated with it, unless it knows in
545 * advance what's going to happen to the event during processing. This
546 * knowledge, however, may not be available to it, so it can simply specify time
547 * to wait before the system can be suspended and pass it as the second
548 * argument of pm_wakeup_event().
549 *
550 * It is valid to call pm_relax() after pm_wakeup_event(), in which case the
551 * "no suspend" period will be ended either by the pm_relax(), or by the timer
552 * function executed when the timer expires, whichever comes first.
553 */
554
555/**
556 * wakeup_source_activate - Mark given wakeup source as active.
557 * @ws: Wakeup source to handle.
558 *
559 * Update the @ws' statistics and, if @ws has just been activated, notify the PM
560 * core of the event by incrementing the counter of the wakeup events being
561 * processed.
562 */
563static void wakeup_source_activate(struct wakeup_source *ws)
564{
565 unsigned int cec;
566
567 if (WARN_ONCE(wakeup_source_not_registered(ws),
568 "unregistered wakeup source\n"))
569 return;
570
571 ws->active = true;
572 ws->active_count++;
573 ws->last_time = ktime_get();
574 if (ws->autosleep_enabled)
575 ws->start_prevent_time = ws->last_time;
576
577 /* Increment the counter of events in progress. */
578 cec = atomic_inc_return(&combined_event_count);
579
580 trace_wakeup_source_activate(ws->name, cec);
581}
582
583/**
584 * wakeup_source_report_event - Report wakeup event using the given source.
585 * @ws: Wakeup source to report the event for.
586 * @hard: If set, abort suspends in progress and wake up from suspend-to-idle.
587 */
588static void wakeup_source_report_event(struct wakeup_source *ws, bool hard)
589{
590 ws->event_count++;
591 /* This is racy, but the counter is approximate anyway. */
592 if (events_check_enabled)
593 ws->wakeup_count++;
594
595 if (!ws->active)
596 wakeup_source_activate(ws);
597
598 if (hard)
599 pm_system_wakeup();
600}
601
602/**
603 * __pm_stay_awake - Notify the PM core of a wakeup event.
604 * @ws: Wakeup source object associated with the source of the event.
605 *
606 * It is safe to call this function from interrupt context.
607 */
608void __pm_stay_awake(struct wakeup_source *ws)
609{
610 unsigned long flags;
611
612 if (!ws)
613 return;
614
615 spin_lock_irqsave(&ws->lock, flags);
616
617 wakeup_source_report_event(ws, false);
618 del_timer(&ws->timer);
619 ws->timer_expires = 0;
620
621 spin_unlock_irqrestore(&ws->lock, flags);
622}
623EXPORT_SYMBOL_GPL(__pm_stay_awake);
624
625/**
626 * pm_stay_awake - Notify the PM core that a wakeup event is being processed.
627 * @dev: Device the wakeup event is related to.
628 *
629 * Notify the PM core of a wakeup event (signaled by @dev) by calling
630 * __pm_stay_awake for the @dev's wakeup source object.
631 *
632 * Call this function after detecting of a wakeup event if pm_relax() is going
633 * to be called directly after processing the event (and possibly passing it to
634 * user space for further processing).
635 */
636void pm_stay_awake(struct device *dev)
637{
638 unsigned long flags;
639
640 if (!dev)
641 return;
642
643 spin_lock_irqsave(&dev->power.lock, flags);
644 __pm_stay_awake(dev->power.wakeup);
645 spin_unlock_irqrestore(&dev->power.lock, flags);
646}
647EXPORT_SYMBOL_GPL(pm_stay_awake);
648
649#ifdef CONFIG_PM_AUTOSLEEP
650static void update_prevent_sleep_time(struct wakeup_source *ws, ktime_t now)
651{
652 ktime_t delta = ktime_sub(now, ws->start_prevent_time);
653 ws->prevent_sleep_time = ktime_add(ws->prevent_sleep_time, delta);
654}
655#else
656static inline void update_prevent_sleep_time(struct wakeup_source *ws,
657 ktime_t now) {}
658#endif
659
660/**
661 * wakeup_source_deactivate - Mark given wakeup source as inactive.
662 * @ws: Wakeup source to handle.
663 *
664 * Update the @ws' statistics and notify the PM core that the wakeup source has
665 * become inactive by decrementing the counter of wakeup events being processed
666 * and incrementing the counter of registered wakeup events.
667 */
668static void wakeup_source_deactivate(struct wakeup_source *ws)
669{
670 unsigned int cnt, inpr, cec;
671 ktime_t duration;
672 ktime_t now;
673
674 ws->relax_count++;
675 /*
676 * __pm_relax() may be called directly or from a timer function.
677 * If it is called directly right after the timer function has been
678 * started, but before the timer function calls __pm_relax(), it is
679 * possible that __pm_stay_awake() will be called in the meantime and
680 * will set ws->active. Then, ws->active may be cleared immediately
681 * by the __pm_relax() called from the timer function, but in such a
682 * case ws->relax_count will be different from ws->active_count.
683 */
684 if (ws->relax_count != ws->active_count) {
685 ws->relax_count--;
686 return;
687 }
688
689 ws->active = false;
690
691 now = ktime_get();
692 duration = ktime_sub(now, ws->last_time);
693 ws->total_time = ktime_add(ws->total_time, duration);
694 if (ktime_to_ns(duration) > ktime_to_ns(ws->max_time))
695 ws->max_time = duration;
696
697 ws->last_time = now;
698 del_timer(&ws->timer);
699 ws->timer_expires = 0;
700
701 if (ws->autosleep_enabled)
702 update_prevent_sleep_time(ws, now);
703
704 /*
705 * Increment the counter of registered wakeup events and decrement the
706 * counter of wakeup events in progress simultaneously.
707 */
708 cec = atomic_add_return(MAX_IN_PROGRESS, &combined_event_count);
709 trace_wakeup_source_deactivate(ws->name, cec);
710
711 split_counters(&cnt, &inpr);
712 if (!inpr && waitqueue_active(&wakeup_count_wait_queue))
713 wake_up(&wakeup_count_wait_queue);
714}
715
716/**
717 * __pm_relax - Notify the PM core that processing of a wakeup event has ended.
718 * @ws: Wakeup source object associated with the source of the event.
719 *
720 * Call this function for wakeup events whose processing started with calling
721 * __pm_stay_awake().
722 *
723 * It is safe to call it from interrupt context.
724 */
725void __pm_relax(struct wakeup_source *ws)
726{
727 unsigned long flags;
728
729 if (!ws)
730 return;
731
732 spin_lock_irqsave(&ws->lock, flags);
733 if (ws->active)
734 wakeup_source_deactivate(ws);
735 spin_unlock_irqrestore(&ws->lock, flags);
736}
737EXPORT_SYMBOL_GPL(__pm_relax);
738
739/**
740 * pm_relax - Notify the PM core that processing of a wakeup event has ended.
741 * @dev: Device that signaled the event.
742 *
743 * Execute __pm_relax() for the @dev's wakeup source object.
744 */
745void pm_relax(struct device *dev)
746{
747 unsigned long flags;
748
749 if (!dev)
750 return;
751
752 spin_lock_irqsave(&dev->power.lock, flags);
753 __pm_relax(dev->power.wakeup);
754 spin_unlock_irqrestore(&dev->power.lock, flags);
755}
756EXPORT_SYMBOL_GPL(pm_relax);
757
758/**
759 * pm_wakeup_timer_fn - Delayed finalization of a wakeup event.
760 * @t: timer list
761 *
762 * Call wakeup_source_deactivate() for the wakeup source whose address is stored
763 * in @data if it is currently active and its timer has not been canceled and
764 * the expiration time of the timer is not in future.
765 */
766static void pm_wakeup_timer_fn(struct timer_list *t)
767{
768 struct wakeup_source *ws = from_timer(ws, t, timer);
769 unsigned long flags;
770
771 spin_lock_irqsave(&ws->lock, flags);
772
773 if (ws->active && ws->timer_expires
774 && time_after_eq(jiffies, ws->timer_expires)) {
775 wakeup_source_deactivate(ws);
776 ws->expire_count++;
777 }
778
779 spin_unlock_irqrestore(&ws->lock, flags);
780}
781
782/**
783 * pm_wakeup_ws_event - Notify the PM core of a wakeup event.
784 * @ws: Wakeup source object associated with the event source.
785 * @msec: Anticipated event processing time (in milliseconds).
786 * @hard: If set, abort suspends in progress and wake up from suspend-to-idle.
787 *
788 * Notify the PM core of a wakeup event whose source is @ws that will take
789 * approximately @msec milliseconds to be processed by the kernel. If @ws is
790 * not active, activate it. If @msec is nonzero, set up the @ws' timer to
791 * execute pm_wakeup_timer_fn() in future.
792 *
793 * It is safe to call this function from interrupt context.
794 */
795void pm_wakeup_ws_event(struct wakeup_source *ws, unsigned int msec, bool hard)
796{
797 unsigned long flags;
798 unsigned long expires;
799
800 if (!ws)
801 return;
802
803 spin_lock_irqsave(&ws->lock, flags);
804
805 wakeup_source_report_event(ws, hard);
806
807 if (!msec) {
808 wakeup_source_deactivate(ws);
809 goto unlock;
810 }
811
812 expires = jiffies + msecs_to_jiffies(msec);
813 if (!expires)
814 expires = 1;
815
816 if (!ws->timer_expires || time_after(expires, ws->timer_expires)) {
817 mod_timer(&ws->timer, expires);
818 ws->timer_expires = expires;
819 }
820
821 unlock:
822 spin_unlock_irqrestore(&ws->lock, flags);
823}
824EXPORT_SYMBOL_GPL(pm_wakeup_ws_event);
825
826/**
827 * pm_wakeup_dev_event - Notify the PM core of a wakeup event.
828 * @dev: Device the wakeup event is related to.
829 * @msec: Anticipated event processing time (in milliseconds).
830 * @hard: If set, abort suspends in progress and wake up from suspend-to-idle.
831 *
832 * Call pm_wakeup_ws_event() for the @dev's wakeup source object.
833 */
834void pm_wakeup_dev_event(struct device *dev, unsigned int msec, bool hard)
835{
836 unsigned long flags;
837
838 if (!dev)
839 return;
840
841 spin_lock_irqsave(&dev->power.lock, flags);
842 pm_wakeup_ws_event(dev->power.wakeup, msec, hard);
843 spin_unlock_irqrestore(&dev->power.lock, flags);
844}
845EXPORT_SYMBOL_GPL(pm_wakeup_dev_event);
846
847void pm_print_active_wakeup_sources(void)
848{
849 struct wakeup_source *ws;
850 int srcuidx, active = 0;
851 struct wakeup_source *last_activity_ws = NULL;
852
853 srcuidx = srcu_read_lock(&wakeup_srcu);
854 list_for_each_entry_rcu_locked(ws, &wakeup_sources, entry) {
855 if (ws->active) {
856 pm_pr_dbg("active wakeup source: %s\n", ws->name);
857 active = 1;
858 } else if (!active &&
859 (!last_activity_ws ||
860 ktime_to_ns(ws->last_time) >
861 ktime_to_ns(last_activity_ws->last_time))) {
862 last_activity_ws = ws;
863 }
864 }
865
866 if (!active && last_activity_ws)
867 pm_pr_dbg("last active wakeup source: %s\n",
868 last_activity_ws->name);
869 srcu_read_unlock(&wakeup_srcu, srcuidx);
870}
871EXPORT_SYMBOL_GPL(pm_print_active_wakeup_sources);
872
873/**
874 * pm_wakeup_pending - Check if power transition in progress should be aborted.
875 *
876 * Compare the current number of registered wakeup events with its preserved
877 * value from the past and return true if new wakeup events have been registered
878 * since the old value was stored. Also return true if the current number of
879 * wakeup events being processed is different from zero.
880 */
881bool pm_wakeup_pending(void)
882{
883 unsigned long flags;
884 bool ret = false;
885
886 raw_spin_lock_irqsave(&events_lock, flags);
887 if (events_check_enabled) {
888 unsigned int cnt, inpr;
889
890 split_counters(&cnt, &inpr);
891 ret = (cnt != saved_count || inpr > 0);
892 events_check_enabled = !ret;
893 }
894 raw_spin_unlock_irqrestore(&events_lock, flags);
895
896 if (ret) {
897 pm_pr_dbg("Wakeup pending, aborting suspend\n");
898 pm_print_active_wakeup_sources();
899 }
900
901 return ret || atomic_read(&pm_abort_suspend) > 0;
902}
903EXPORT_SYMBOL_GPL(pm_wakeup_pending);
904
905void pm_system_wakeup(void)
906{
907 atomic_inc(&pm_abort_suspend);
908 s2idle_wake();
909}
910EXPORT_SYMBOL_GPL(pm_system_wakeup);
911
912void pm_system_cancel_wakeup(void)
913{
914 atomic_dec_if_positive(&pm_abort_suspend);
915}
916
917void pm_wakeup_clear(unsigned int irq_number)
918{
919 raw_spin_lock_irq(&wakeup_irq_lock);
920
921 if (irq_number && wakeup_irq[0] == irq_number)
922 wakeup_irq[0] = wakeup_irq[1];
923 else
924 wakeup_irq[0] = 0;
925
926 wakeup_irq[1] = 0;
927
928 raw_spin_unlock_irq(&wakeup_irq_lock);
929
930 if (!irq_number)
931 atomic_set(&pm_abort_suspend, 0);
932}
933
934void pm_system_irq_wakeup(unsigned int irq_number)
935{
936 unsigned long flags;
937
938 raw_spin_lock_irqsave(&wakeup_irq_lock, flags);
939
940 if (wakeup_irq[0] == 0)
941 wakeup_irq[0] = irq_number;
942 else if (wakeup_irq[1] == 0)
943 wakeup_irq[1] = irq_number;
944 else
945 irq_number = 0;
946
947 pm_pr_dbg("Triggering wakeup from IRQ %d\n", irq_number);
948
949 raw_spin_unlock_irqrestore(&wakeup_irq_lock, flags);
950
951 if (irq_number)
952 pm_system_wakeup();
953}
954
955unsigned int pm_wakeup_irq(void)
956{
957 return wakeup_irq[0];
958}
959
960/**
961 * pm_get_wakeup_count - Read the number of registered wakeup events.
962 * @count: Address to store the value at.
963 * @block: Whether or not to block.
964 *
965 * Store the number of registered wakeup events at the address in @count. If
966 * @block is set, block until the current number of wakeup events being
967 * processed is zero.
968 *
969 * Return 'false' if the current number of wakeup events being processed is
970 * nonzero. Otherwise return 'true'.
971 */
972bool pm_get_wakeup_count(unsigned int *count, bool block)
973{
974 unsigned int cnt, inpr;
975
976 if (block) {
977 DEFINE_WAIT(wait);
978
979 for (;;) {
980 prepare_to_wait(&wakeup_count_wait_queue, &wait,
981 TASK_INTERRUPTIBLE);
982 split_counters(&cnt, &inpr);
983 if (inpr == 0 || signal_pending(current))
984 break;
985 pm_print_active_wakeup_sources();
986 schedule();
987 }
988 finish_wait(&wakeup_count_wait_queue, &wait);
989 }
990
991 split_counters(&cnt, &inpr);
992 *count = cnt;
993 return !inpr;
994}
995
996/**
997 * pm_save_wakeup_count - Save the current number of registered wakeup events.
998 * @count: Value to compare with the current number of registered wakeup events.
999 *
1000 * If @count is equal to the current number of registered wakeup events and the
1001 * current number of wakeup events being processed is zero, store @count as the
1002 * old number of registered wakeup events for pm_check_wakeup_events(), enable
1003 * wakeup events detection and return 'true'. Otherwise disable wakeup events
1004 * detection and return 'false'.
1005 */
1006bool pm_save_wakeup_count(unsigned int count)
1007{
1008 unsigned int cnt, inpr;
1009 unsigned long flags;
1010
1011 events_check_enabled = false;
1012 raw_spin_lock_irqsave(&events_lock, flags);
1013 split_counters(&cnt, &inpr);
1014 if (cnt == count && inpr == 0) {
1015 saved_count = count;
1016 events_check_enabled = true;
1017 }
1018 raw_spin_unlock_irqrestore(&events_lock, flags);
1019 return events_check_enabled;
1020}
1021
1022#ifdef CONFIG_PM_AUTOSLEEP
1023/**
1024 * pm_wakep_autosleep_enabled - Modify autosleep_enabled for all wakeup sources.
1025 * @set: Whether to set or to clear the autosleep_enabled flags.
1026 */
1027void pm_wakep_autosleep_enabled(bool set)
1028{
1029 struct wakeup_source *ws;
1030 ktime_t now = ktime_get();
1031 int srcuidx;
1032
1033 srcuidx = srcu_read_lock(&wakeup_srcu);
1034 list_for_each_entry_rcu_locked(ws, &wakeup_sources, entry) {
1035 spin_lock_irq(&ws->lock);
1036 if (ws->autosleep_enabled != set) {
1037 ws->autosleep_enabled = set;
1038 if (ws->active) {
1039 if (set)
1040 ws->start_prevent_time = now;
1041 else
1042 update_prevent_sleep_time(ws, now);
1043 }
1044 }
1045 spin_unlock_irq(&ws->lock);
1046 }
1047 srcu_read_unlock(&wakeup_srcu, srcuidx);
1048}
1049#endif /* CONFIG_PM_AUTOSLEEP */
1050
1051/**
1052 * print_wakeup_source_stats - Print wakeup source statistics information.
1053 * @m: seq_file to print the statistics into.
1054 * @ws: Wakeup source object to print the statistics for.
1055 */
1056static int print_wakeup_source_stats(struct seq_file *m,
1057 struct wakeup_source *ws)
1058{
1059 unsigned long flags;
1060 ktime_t total_time;
1061 ktime_t max_time;
1062 unsigned long active_count;
1063 ktime_t active_time;
1064 ktime_t prevent_sleep_time;
1065
1066 spin_lock_irqsave(&ws->lock, flags);
1067
1068 total_time = ws->total_time;
1069 max_time = ws->max_time;
1070 prevent_sleep_time = ws->prevent_sleep_time;
1071 active_count = ws->active_count;
1072 if (ws->active) {
1073 ktime_t now = ktime_get();
1074
1075 active_time = ktime_sub(now, ws->last_time);
1076 total_time = ktime_add(total_time, active_time);
1077 if (active_time > max_time)
1078 max_time = active_time;
1079
1080 if (ws->autosleep_enabled)
1081 prevent_sleep_time = ktime_add(prevent_sleep_time,
1082 ktime_sub(now, ws->start_prevent_time));
1083 } else {
1084 active_time = 0;
1085 }
1086
1087 seq_printf(m, "%-12s\t%lu\t\t%lu\t\t%lu\t\t%lu\t\t%lld\t\t%lld\t\t%lld\t\t%lld\t\t%lld\n",
1088 ws->name, active_count, ws->event_count,
1089 ws->wakeup_count, ws->expire_count,
1090 ktime_to_ms(active_time), ktime_to_ms(total_time),
1091 ktime_to_ms(max_time), ktime_to_ms(ws->last_time),
1092 ktime_to_ms(prevent_sleep_time));
1093
1094 spin_unlock_irqrestore(&ws->lock, flags);
1095
1096 return 0;
1097}
1098
1099static void *wakeup_sources_stats_seq_start(struct seq_file *m,
1100 loff_t *pos)
1101{
1102 struct wakeup_source *ws;
1103 loff_t n = *pos;
1104 int *srcuidx = m->private;
1105
1106 if (n == 0) {
1107 seq_puts(m, "name\t\tactive_count\tevent_count\twakeup_count\t"
1108 "expire_count\tactive_since\ttotal_time\tmax_time\t"
1109 "last_change\tprevent_suspend_time\n");
1110 }
1111
1112 *srcuidx = srcu_read_lock(&wakeup_srcu);
1113 list_for_each_entry_rcu_locked(ws, &wakeup_sources, entry) {
1114 if (n-- <= 0)
1115 return ws;
1116 }
1117
1118 return NULL;
1119}
1120
1121static void *wakeup_sources_stats_seq_next(struct seq_file *m,
1122 void *v, loff_t *pos)
1123{
1124 struct wakeup_source *ws = v;
1125 struct wakeup_source *next_ws = NULL;
1126
1127 ++(*pos);
1128
1129 list_for_each_entry_continue_rcu(ws, &wakeup_sources, entry) {
1130 next_ws = ws;
1131 break;
1132 }
1133
1134 if (!next_ws)
1135 print_wakeup_source_stats(m, &deleted_ws);
1136
1137 return next_ws;
1138}
1139
1140static void wakeup_sources_stats_seq_stop(struct seq_file *m, void *v)
1141{
1142 int *srcuidx = m->private;
1143
1144 srcu_read_unlock(&wakeup_srcu, *srcuidx);
1145}
1146
1147/**
1148 * wakeup_sources_stats_seq_show - Print wakeup sources statistics information.
1149 * @m: seq_file to print the statistics into.
1150 * @v: wakeup_source of each iteration
1151 */
1152static int wakeup_sources_stats_seq_show(struct seq_file *m, void *v)
1153{
1154 struct wakeup_source *ws = v;
1155
1156 print_wakeup_source_stats(m, ws);
1157
1158 return 0;
1159}
1160
1161static const struct seq_operations wakeup_sources_stats_seq_ops = {
1162 .start = wakeup_sources_stats_seq_start,
1163 .next = wakeup_sources_stats_seq_next,
1164 .stop = wakeup_sources_stats_seq_stop,
1165 .show = wakeup_sources_stats_seq_show,
1166};
1167
1168static int wakeup_sources_stats_open(struct inode *inode, struct file *file)
1169{
1170 return seq_open_private(file, &wakeup_sources_stats_seq_ops, sizeof(int));
1171}
1172
1173static const struct file_operations wakeup_sources_stats_fops = {
1174 .owner = THIS_MODULE,
1175 .open = wakeup_sources_stats_open,
1176 .read = seq_read,
1177 .llseek = seq_lseek,
1178 .release = seq_release_private,
1179};
1180
1181static int __init wakeup_sources_debugfs_init(void)
1182{
1183 debugfs_create_file("wakeup_sources", 0444, NULL, NULL,
1184 &wakeup_sources_stats_fops);
1185 return 0;
1186}
1187
1188postcore_initcall(wakeup_sources_debugfs_init);