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