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