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