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