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
23 suspend_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 */
34 bool events_check_enabled __read_mostly;
35
36 /* First wakeup IRQ seen by the kernel in the last cycle. */
37 static unsigned int wakeup_irq[2] __read_mostly;
38 static DEFINE_RAW_SPINLOCK(wakeup_irq_lock);
39
40 /* If greater than 0 and the system is suspending, terminate the suspend. */
41 static 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 */
48 static 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
split_counters(unsigned int * cnt,unsigned int * inpr)53 static 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. */
62 static unsigned int saved_count;
63
64 static DEFINE_RAW_SPINLOCK(events_lock);
65
66 static void pm_wakeup_timer_fn(struct timer_list *t);
67
68 static LIST_HEAD(wakeup_sources);
69
70 static DECLARE_WAIT_QUEUE_HEAD(wakeup_count_wait_queue);
71
72 DEFINE_STATIC_SRCU(wakeup_srcu);
73
74 static struct wakeup_source deleted_ws = {
75 .name = "deleted",
76 .lock = __SPIN_LOCK_UNLOCKED(deleted_ws.lock),
77 };
78
79 static 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 */
wakeup_source_create(const char * name)85 struct 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
107 err_id:
108 kfree_const(ws->name);
109 err_name:
110 kfree(ws);
111 err_ws:
112 return NULL;
113 }
114 EXPORT_SYMBOL_GPL(wakeup_source_create);
115
116 /*
117 * Record wakeup_source statistics being deleted into a dummy wakeup_source.
118 */
wakeup_source_record(struct wakeup_source * ws)119 static 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
wakeup_source_free(struct wakeup_source * ws)144 static 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 */
wakeup_source_destroy(struct wakeup_source * ws)157 void 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 }
166 EXPORT_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 */
wakeup_source_add(struct wakeup_source * ws)172 void 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 }
187 EXPORT_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 */
wakeup_source_remove(struct wakeup_source * ws)193 void 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 }
212 EXPORT_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 */
wakeup_source_register(struct device * dev,const char * name)219 struct 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 }
238 EXPORT_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 */
wakeup_source_unregister(struct wakeup_source * ws)244 void 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 }
254 EXPORT_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 */
wakeup_sources_read_lock(void)262 int wakeup_sources_read_lock(void)
263 {
264 return srcu_read_lock(&wakeup_srcu);
265 }
266 EXPORT_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 */
wakeup_sources_read_unlock(int idx)272 void wakeup_sources_read_unlock(int idx)
273 {
274 srcu_read_unlock(&wakeup_srcu, idx);
275 }
276 EXPORT_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 */
wakeup_sources_walk_start(void)286 struct 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 }
292 EXPORT_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 */
wakeup_sources_walk_next(struct wakeup_source * ws)301 struct 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 }
308 EXPORT_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 */
device_wakeup_attach(struct device * dev,struct wakeup_source * ws)317 static 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 */
device_wakeup_enable(struct device * dev)337 int 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 }
358 EXPORT_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 */
device_wakeup_attach_irq(struct device * dev,struct wake_irq * wakeirq)371 void 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 */
device_wakeup_detach_irq(struct device * dev)394 void 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 */
device_wakeup_arm_wake_irqs(void)408 void 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 */
device_wakeup_disarm_wake_irqs(void)424 void 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 */
device_wakeup_detach(struct device * dev)441 static 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 */
device_wakeup_disable(struct device * dev)459 int 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 }
470 EXPORT_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 */
device_set_wakeup_capable(struct device * dev,bool capable)484 void 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 }
501 EXPORT_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 */
device_set_wakeup_enable(struct device * dev,bool enable)508 int device_set_wakeup_enable(struct device *dev, bool enable)
509 {
510 return enable ? device_wakeup_enable(dev) : device_wakeup_disable(dev);
511 }
512 EXPORT_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 */
wakeup_source_not_registered(struct wakeup_source * ws)518 static 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 */
wakeup_source_activate(struct wakeup_source * ws)563 static 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 */
wakeup_source_report_event(struct wakeup_source * ws,bool hard)588 static 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 */
__pm_stay_awake(struct wakeup_source * ws)608 void __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 }
623 EXPORT_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 */
pm_stay_awake(struct device * dev)636 void 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 }
647 EXPORT_SYMBOL_GPL(pm_stay_awake);
648
649 #ifdef CONFIG_PM_AUTOSLEEP
update_prevent_sleep_time(struct wakeup_source * ws,ktime_t now)650 static 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
update_prevent_sleep_time(struct wakeup_source * ws,ktime_t now)656 static 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 */
wakeup_source_deactivate(struct wakeup_source * ws)668 static 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 */
__pm_relax(struct wakeup_source * ws)725 void __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 }
737 EXPORT_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 */
pm_relax(struct device * dev)745 void 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 }
756 EXPORT_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 */
pm_wakeup_timer_fn(struct timer_list * t)766 static 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 */
pm_wakeup_ws_event(struct wakeup_source * ws,unsigned int msec,bool hard)795 void 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 }
824 EXPORT_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 */
pm_wakeup_dev_event(struct device * dev,unsigned int msec,bool hard)834 void 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 }
845 EXPORT_SYMBOL_GPL(pm_wakeup_dev_event);
846
pm_print_active_wakeup_sources(void)847 void 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 }
871 EXPORT_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 */
pm_wakeup_pending(void)881 bool 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 }
903 EXPORT_SYMBOL_GPL(pm_wakeup_pending);
904
pm_system_wakeup(void)905 void pm_system_wakeup(void)
906 {
907 atomic_inc(&pm_abort_suspend);
908 s2idle_wake();
909 }
910 EXPORT_SYMBOL_GPL(pm_system_wakeup);
911
pm_system_cancel_wakeup(void)912 void pm_system_cancel_wakeup(void)
913 {
914 atomic_dec_if_positive(&pm_abort_suspend);
915 }
916
pm_wakeup_clear(unsigned int irq_number)917 void 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
pm_system_irq_wakeup(unsigned int irq_number)934 void 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
pm_wakeup_irq(void)955 unsigned 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 */
pm_get_wakeup_count(unsigned int * count,bool block)972 bool 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 */
pm_save_wakeup_count(unsigned int count)1006 bool 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 */
pm_wakep_autosleep_enabled(bool set)1027 void 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 */
print_wakeup_source_stats(struct seq_file * m,struct wakeup_source * ws)1056 static 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
wakeup_sources_stats_seq_start(struct seq_file * m,loff_t * pos)1099 static 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
wakeup_sources_stats_seq_next(struct seq_file * m,void * v,loff_t * pos)1121 static 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
wakeup_sources_stats_seq_stop(struct seq_file * m,void * v)1140 static 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 */
wakeup_sources_stats_seq_show(struct seq_file * m,void * v)1152 static 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
1161 static 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
wakeup_sources_stats_open(struct inode * inode,struct file * file)1168 static 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
1173 static 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
wakeup_sources_debugfs_init(void)1181 static 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
1188 postcore_initcall(wakeup_sources_debugfs_init);
1189