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