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