xref: /linux/drivers/base/power/wakeup.c (revision 621cde16e49b3ecf7d59a8106a20aaebfb4a59a9)
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 
split_counters(unsigned int * cnt,unsigned int * inpr)48 static void split_counters(unsigned int *cnt, unsigned int *inpr)
49 {
50 	unsigned int comb = atomic_read(&combined_event_count);
51 
52 	*cnt = (comb >> IN_PROGRESS_BITS);
53 	*inpr = comb & MAX_IN_PROGRESS;
54 }
55 
56 /* A preserved old value of the events counter. */
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  */
wakeup_source_create(const char * name)80 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 	ws = kzalloc(sizeof(*ws), GFP_KERNEL);
87 	if (!ws)
88 		goto err_ws;
89 
90 	ws_name = kstrdup_const(name, GFP_KERNEL);
91 	if (!ws_name)
92 		goto err_name;
93 	ws->name = ws_name;
94 
95 	id = ida_alloc(&wakeup_ida, GFP_KERNEL);
96 	if (id < 0)
97 		goto err_id;
98 	ws->id = id;
99 
100 	return ws;
101 
102 err_id:
103 	kfree_const(ws->name);
104 err_name:
105 	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  */
wakeup_source_record(struct wakeup_source * ws)114 static void wakeup_source_record(struct wakeup_source *ws)
115 {
116 	unsigned long flags;
117 
118 	spin_lock_irqsave(&deleted_ws.lock, flags);
119 
120 	if (ws->event_count) {
121 		deleted_ws.total_time =
122 			ktime_add(deleted_ws.total_time, ws->total_time);
123 		deleted_ws.prevent_sleep_time =
124 			ktime_add(deleted_ws.prevent_sleep_time,
125 				  ws->prevent_sleep_time);
126 		deleted_ws.max_time =
127 			ktime_compare(deleted_ws.max_time, ws->max_time) > 0 ?
128 				deleted_ws.max_time : ws->max_time;
129 		deleted_ws.event_count += ws->event_count;
130 		deleted_ws.active_count += ws->active_count;
131 		deleted_ws.relax_count += ws->relax_count;
132 		deleted_ws.expire_count += ws->expire_count;
133 		deleted_ws.wakeup_count += ws->wakeup_count;
134 	}
135 
136 	spin_unlock_irqrestore(&deleted_ws.lock, flags);
137 }
138 
wakeup_source_free(struct wakeup_source * ws)139 static void wakeup_source_free(struct wakeup_source *ws)
140 {
141 	ida_free(&wakeup_ida, ws->id);
142 	kfree_const(ws->name);
143 	kfree(ws);
144 }
145 
146 /**
147  * wakeup_source_destroy - Destroy a struct wakeup_source object.
148  * @ws: Wakeup source to destroy.
149  *
150  * Use only for wakeup source objects created with wakeup_source_create().
151  */
wakeup_source_destroy(struct wakeup_source * ws)152 void wakeup_source_destroy(struct wakeup_source *ws)
153 {
154 	if (!ws)
155 		return;
156 
157 	__pm_relax(ws);
158 	wakeup_source_record(ws);
159 	wakeup_source_free(ws);
160 }
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  */
wakeup_source_add(struct wakeup_source * ws)167 void wakeup_source_add(struct wakeup_source *ws)
168 {
169 	unsigned long flags;
170 
171 	if (WARN_ON(!ws))
172 		return;
173 
174 	spin_lock_init(&ws->lock);
175 	timer_setup(&ws->timer, pm_wakeup_timer_fn, 0);
176 	ws->active = false;
177 
178 	raw_spin_lock_irqsave(&events_lock, flags);
179 	list_add_rcu(&ws->entry, &wakeup_sources);
180 	raw_spin_unlock_irqrestore(&events_lock, flags);
181 }
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  */
wakeup_source_remove(struct wakeup_source * ws)188 void wakeup_source_remove(struct wakeup_source *ws)
189 {
190 	unsigned long flags;
191 
192 	if (WARN_ON(!ws))
193 		return;
194 
195 	raw_spin_lock_irqsave(&events_lock, flags);
196 	list_del_rcu(&ws->entry);
197 	raw_spin_unlock_irqrestore(&events_lock, flags);
198 	synchronize_srcu(&wakeup_srcu);
199 
200 	del_timer_sync(&ws->timer);
201 	/*
202 	 * Clear timer.function to make wakeup_source_not_registered() treat
203 	 * this wakeup source as not registered.
204 	 */
205 	ws->timer.function = NULL;
206 }
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  */
wakeup_source_register(struct device * dev,const char * name)214 struct wakeup_source *wakeup_source_register(struct device *dev,
215 					     const char *name)
216 {
217 	struct wakeup_source *ws;
218 	int ret;
219 
220 	ws = wakeup_source_create(name);
221 	if (ws) {
222 		if (!dev || device_is_registered(dev)) {
223 			ret = wakeup_source_sysfs_add(dev, ws);
224 			if (ret) {
225 				wakeup_source_free(ws);
226 				return NULL;
227 			}
228 		}
229 		wakeup_source_add(ws);
230 	}
231 	return ws;
232 }
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  */
wakeup_source_unregister(struct wakeup_source * ws)239 void wakeup_source_unregister(struct wakeup_source *ws)
240 {
241 	if (ws) {
242 		wakeup_source_remove(ws);
243 		if (ws->dev)
244 			wakeup_source_sysfs_remove(ws);
245 
246 		wakeup_source_destroy(ws);
247 	}
248 }
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  */
wakeup_sources_read_lock(void)257 int wakeup_sources_read_lock(void)
258 {
259 	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  */
wakeup_sources_read_unlock(int idx)267 void wakeup_sources_read_unlock(int idx)
268 {
269 	srcu_read_unlock(&wakeup_srcu, idx);
270 }
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  */
wakeup_sources_walk_start(void)281 struct wakeup_source *wakeup_sources_walk_start(void)
282 {
283 	struct list_head *ws_head = &wakeup_sources;
284 
285 	return list_entry_rcu(ws_head->next, struct wakeup_source, entry);
286 }
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  */
wakeup_sources_walk_next(struct wakeup_source * ws)296 struct wakeup_source *wakeup_sources_walk_next(struct wakeup_source *ws)
297 {
298 	struct list_head *ws_head = &wakeup_sources;
299 
300 	return list_next_or_null_rcu(ws_head, &ws->entry,
301 				struct wakeup_source, entry);
302 }
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  */
device_wakeup_attach(struct device * dev,struct wakeup_source * ws)312 static int device_wakeup_attach(struct device *dev, struct wakeup_source *ws)
313 {
314 	spin_lock_irq(&dev->power.lock);
315 	if (dev->power.wakeup) {
316 		spin_unlock_irq(&dev->power.lock);
317 		return -EEXIST;
318 	}
319 	dev->power.wakeup = ws;
320 	if (dev->power.wakeirq)
321 		device_wakeup_attach_irq(dev, dev->power.wakeirq);
322 	spin_unlock_irq(&dev->power.lock);
323 	return 0;
324 }
325 
326 /**
327  * device_wakeup_enable - Enable given device to be a wakeup source.
328  * @dev: Device to handle.
329  *
330  * Create a wakeup source object, register it and attach it to @dev.
331  */
device_wakeup_enable(struct device * dev)332 int device_wakeup_enable(struct device *dev)
333 {
334 	struct wakeup_source *ws;
335 	int ret;
336 
337 	if (!dev || !dev->power.can_wakeup)
338 		return -EINVAL;
339 
340 	if (pm_suspend_target_state != PM_SUSPEND_ON)
341 		dev_dbg(dev, "Suspicious %s() during system transition!\n", __func__);
342 
343 	ws = wakeup_source_register(dev, dev_name(dev));
344 	if (!ws)
345 		return -ENOMEM;
346 
347 	ret = device_wakeup_attach(dev, ws);
348 	if (ret)
349 		wakeup_source_unregister(ws);
350 
351 	return ret;
352 }
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  */
device_wakeup_attach_irq(struct device * dev,struct wake_irq * wakeirq)366 void device_wakeup_attach_irq(struct device *dev,
367 			     struct wake_irq *wakeirq)
368 {
369 	struct wakeup_source *ws;
370 
371 	ws = dev->power.wakeup;
372 	if (!ws)
373 		return;
374 
375 	if (ws->wakeirq)
376 		dev_err(dev, "Leftover wakeup IRQ found, overriding\n");
377 
378 	ws->wakeirq = wakeirq;
379 }
380 
381 /**
382  * device_wakeup_detach_irq - Detach a wakeirq from a wakeup source
383  * @dev: Device to handle
384  *
385  * Removes a device wakeirq from the wakeup source.
386  *
387  * Call under the device's power.lock lock.
388  */
device_wakeup_detach_irq(struct device * dev)389 void device_wakeup_detach_irq(struct device *dev)
390 {
391 	struct wakeup_source *ws;
392 
393 	ws = dev->power.wakeup;
394 	if (ws)
395 		ws->wakeirq = NULL;
396 }
397 
398 /**
399  * device_wakeup_arm_wake_irqs -
400  *
401  * Iterates over the list of device wakeirqs to arm them.
402  */
device_wakeup_arm_wake_irqs(void)403 void device_wakeup_arm_wake_irqs(void)
404 {
405 	struct wakeup_source *ws;
406 	int srcuidx;
407 
408 	srcuidx = srcu_read_lock(&wakeup_srcu);
409 	list_for_each_entry_rcu_locked(ws, &wakeup_sources, entry)
410 		dev_pm_arm_wake_irq(ws->wakeirq);
411 	srcu_read_unlock(&wakeup_srcu, srcuidx);
412 }
413 
414 /**
415  * device_wakeup_disarm_wake_irqs -
416  *
417  * Iterates over the list of device wakeirqs to disarm them.
418  */
device_wakeup_disarm_wake_irqs(void)419 void device_wakeup_disarm_wake_irqs(void)
420 {
421 	struct wakeup_source *ws;
422 	int srcuidx;
423 
424 	srcuidx = srcu_read_lock(&wakeup_srcu);
425 	list_for_each_entry_rcu_locked(ws, &wakeup_sources, entry)
426 		dev_pm_disarm_wake_irq(ws->wakeirq);
427 	srcu_read_unlock(&wakeup_srcu, srcuidx);
428 }
429 
430 /**
431  * device_wakeup_detach - Detach a device's wakeup source object from it.
432  * @dev: Device to detach the wakeup source object from.
433  *
434  * After it returns, @dev will not be treated as a wakeup device any more.
435  */
device_wakeup_detach(struct device * dev)436 static struct wakeup_source *device_wakeup_detach(struct device *dev)
437 {
438 	struct wakeup_source *ws;
439 
440 	spin_lock_irq(&dev->power.lock);
441 	ws = dev->power.wakeup;
442 	dev->power.wakeup = NULL;
443 	spin_unlock_irq(&dev->power.lock);
444 	return ws;
445 }
446 
447 /**
448  * device_wakeup_disable - Do not regard a device as a wakeup source any more.
449  * @dev: Device to handle.
450  *
451  * Detach the @dev's wakeup source object from it, unregister this wakeup source
452  * object and destroy it.
453  */
device_wakeup_disable(struct device * dev)454 void device_wakeup_disable(struct device *dev)
455 {
456 	struct wakeup_source *ws;
457 
458 	if (!dev || !dev->power.can_wakeup)
459 		return;
460 
461 	ws = device_wakeup_detach(dev);
462 	wakeup_source_unregister(ws);
463 }
464 EXPORT_SYMBOL_GPL(device_wakeup_disable);
465 
466 /**
467  * device_set_wakeup_capable - Set/reset device wakeup capability flag.
468  * @dev: Device to handle.
469  * @capable: Whether or not @dev is capable of waking up the system from sleep.
470  *
471  * If @capable is set, set the @dev's power.can_wakeup flag and add its
472  * wakeup-related attributes to sysfs.  Otherwise, unset the @dev's
473  * power.can_wakeup flag and remove its wakeup-related attributes from sysfs.
474  *
475  * This function may sleep and it can't be called from any context where
476  * sleeping is not allowed.
477  */
device_set_wakeup_capable(struct device * dev,bool capable)478 void device_set_wakeup_capable(struct device *dev, bool capable)
479 {
480 	if (!!dev->power.can_wakeup == !!capable)
481 		return;
482 
483 	dev->power.can_wakeup = capable;
484 	if (device_is_registered(dev) && !list_empty(&dev->power.entry)) {
485 		if (capable) {
486 			int ret = wakeup_sysfs_add(dev);
487 
488 			if (ret)
489 				dev_info(dev, "Wakeup sysfs attributes not added\n");
490 		} else {
491 			wakeup_sysfs_remove(dev);
492 		}
493 	}
494 }
495 EXPORT_SYMBOL_GPL(device_set_wakeup_capable);
496 
497 /**
498  * device_set_wakeup_enable - Enable or disable a device to wake up the system.
499  * @dev: Device to handle.
500  * @enable: enable/disable flag
501  */
device_set_wakeup_enable(struct device * dev,bool enable)502 int device_set_wakeup_enable(struct device *dev, bool enable)
503 {
504 	if (enable)
505 		return device_wakeup_enable(dev);
506 
507 	device_wakeup_disable(dev);
508 	return 0;
509 }
510 EXPORT_SYMBOL_GPL(device_set_wakeup_enable);
511 
512 /**
513  * wakeup_source_not_registered - validate the given wakeup source.
514  * @ws: Wakeup source to be validated.
515  */
wakeup_source_not_registered(struct wakeup_source * ws)516 static bool wakeup_source_not_registered(struct wakeup_source *ws)
517 {
518 	/*
519 	 * Use timer struct to check if the given source is initialized
520 	 * by wakeup_source_add.
521 	 */
522 	return ws->timer.function != pm_wakeup_timer_fn;
523 }
524 
525 /*
526  * The functions below use the observation that each wakeup event starts a
527  * period in which the system should not be suspended.  The moment this period
528  * will end depends on how the wakeup event is going to be processed after being
529  * detected and all of the possible cases can be divided into two distinct
530  * groups.
531  *
532  * First, a wakeup event may be detected by the same functional unit that will
533  * carry out the entire processing of it and possibly will pass it to user space
534  * for further processing.  In that case the functional unit that has detected
535  * the event may later "close" the "no suspend" period associated with it
536  * directly as soon as it has been dealt with.  The pair of pm_stay_awake() and
537  * pm_relax(), balanced with each other, is supposed to be used in such
538  * situations.
539  *
540  * Second, a wakeup event may be detected by one functional unit and processed
541  * by another one.  In that case the unit that has detected it cannot really
542  * "close" the "no suspend" period associated with it, unless it knows in
543  * advance what's going to happen to the event during processing.  This
544  * knowledge, however, may not be available to it, so it can simply specify time
545  * to wait before the system can be suspended and pass it as the second
546  * argument of pm_wakeup_event().
547  *
548  * It is valid to call pm_relax() after pm_wakeup_event(), in which case the
549  * "no suspend" period will be ended either by the pm_relax(), or by the timer
550  * function executed when the timer expires, whichever comes first.
551  */
552 
553 /**
554  * wakeup_source_activate - Mark given wakeup source as active.
555  * @ws: Wakeup source to handle.
556  *
557  * Update the @ws' statistics and, if @ws has just been activated, notify the PM
558  * core of the event by incrementing the counter of the wakeup events being
559  * processed.
560  */
wakeup_source_activate(struct wakeup_source * ws)561 static void wakeup_source_activate(struct wakeup_source *ws)
562 {
563 	unsigned int cec;
564 
565 	if (WARN_ONCE(wakeup_source_not_registered(ws),
566 			"unregistered wakeup source\n"))
567 		return;
568 
569 	ws->active = true;
570 	ws->active_count++;
571 	ws->last_time = ktime_get();
572 	if (ws->autosleep_enabled)
573 		ws->start_prevent_time = ws->last_time;
574 
575 	/* Increment the counter of events in progress. */
576 	cec = atomic_inc_return(&combined_event_count);
577 
578 	trace_wakeup_source_activate(ws->name, cec);
579 }
580 
581 /**
582  * wakeup_source_report_event - Report wakeup event using the given source.
583  * @ws: Wakeup source to report the event for.
584  * @hard: If set, abort suspends in progress and wake up from suspend-to-idle.
585  */
wakeup_source_report_event(struct wakeup_source * ws,bool hard)586 static void wakeup_source_report_event(struct wakeup_source *ws, bool hard)
587 {
588 	ws->event_count++;
589 	/* This is racy, but the counter is approximate anyway. */
590 	if (events_check_enabled)
591 		ws->wakeup_count++;
592 
593 	if (!ws->active)
594 		wakeup_source_activate(ws);
595 
596 	if (hard)
597 		pm_system_wakeup();
598 }
599 
600 /**
601  * __pm_stay_awake - Notify the PM core of a wakeup event.
602  * @ws: Wakeup source object associated with the source of the event.
603  *
604  * It is safe to call this function from interrupt context.
605  */
__pm_stay_awake(struct wakeup_source * ws)606 void __pm_stay_awake(struct wakeup_source *ws)
607 {
608 	unsigned long flags;
609 
610 	if (!ws)
611 		return;
612 
613 	spin_lock_irqsave(&ws->lock, flags);
614 
615 	wakeup_source_report_event(ws, false);
616 	del_timer(&ws->timer);
617 	ws->timer_expires = 0;
618 
619 	spin_unlock_irqrestore(&ws->lock, flags);
620 }
621 EXPORT_SYMBOL_GPL(__pm_stay_awake);
622 
623 /**
624  * pm_stay_awake - Notify the PM core that a wakeup event is being processed.
625  * @dev: Device the wakeup event is related to.
626  *
627  * Notify the PM core of a wakeup event (signaled by @dev) by calling
628  * __pm_stay_awake for the @dev's wakeup source object.
629  *
630  * Call this function after detecting of a wakeup event if pm_relax() is going
631  * to be called directly after processing the event (and possibly passing it to
632  * user space for further processing).
633  */
pm_stay_awake(struct device * dev)634 void pm_stay_awake(struct device *dev)
635 {
636 	unsigned long flags;
637 
638 	if (!dev)
639 		return;
640 
641 	spin_lock_irqsave(&dev->power.lock, flags);
642 	__pm_stay_awake(dev->power.wakeup);
643 	spin_unlock_irqrestore(&dev->power.lock, flags);
644 }
645 EXPORT_SYMBOL_GPL(pm_stay_awake);
646 
647 #ifdef CONFIG_PM_AUTOSLEEP
update_prevent_sleep_time(struct wakeup_source * ws,ktime_t now)648 static void update_prevent_sleep_time(struct wakeup_source *ws, ktime_t now)
649 {
650 	ktime_t delta = ktime_sub(now, ws->start_prevent_time);
651 	ws->prevent_sleep_time = ktime_add(ws->prevent_sleep_time, delta);
652 }
653 #else
update_prevent_sleep_time(struct wakeup_source * ws,ktime_t now)654 static inline void update_prevent_sleep_time(struct wakeup_source *ws,
655 					     ktime_t now) {}
656 #endif
657 
658 /**
659  * wakeup_source_deactivate - Mark given wakeup source as inactive.
660  * @ws: Wakeup source to handle.
661  *
662  * Update the @ws' statistics and notify the PM core that the wakeup source has
663  * become inactive by decrementing the counter of wakeup events being processed
664  * and incrementing the counter of registered wakeup events.
665  */
wakeup_source_deactivate(struct wakeup_source * ws)666 static void wakeup_source_deactivate(struct wakeup_source *ws)
667 {
668 	unsigned int cnt, inpr, cec;
669 	ktime_t duration;
670 	ktime_t now;
671 
672 	ws->relax_count++;
673 	/*
674 	 * __pm_relax() may be called directly or from a timer function.
675 	 * If it is called directly right after the timer function has been
676 	 * started, but before the timer function calls __pm_relax(), it is
677 	 * possible that __pm_stay_awake() will be called in the meantime and
678 	 * will set ws->active.  Then, ws->active may be cleared immediately
679 	 * by the __pm_relax() called from the timer function, but in such a
680 	 * case ws->relax_count will be different from ws->active_count.
681 	 */
682 	if (ws->relax_count != ws->active_count) {
683 		ws->relax_count--;
684 		return;
685 	}
686 
687 	ws->active = false;
688 
689 	now = ktime_get();
690 	duration = ktime_sub(now, ws->last_time);
691 	ws->total_time = ktime_add(ws->total_time, duration);
692 	if (ktime_to_ns(duration) > ktime_to_ns(ws->max_time))
693 		ws->max_time = duration;
694 
695 	ws->last_time = now;
696 	del_timer(&ws->timer);
697 	ws->timer_expires = 0;
698 
699 	if (ws->autosleep_enabled)
700 		update_prevent_sleep_time(ws, now);
701 
702 	/*
703 	 * Increment the counter of registered wakeup events and decrement the
704 	 * counter of wakeup events in progress simultaneously.
705 	 */
706 	cec = atomic_add_return(MAX_IN_PROGRESS, &combined_event_count);
707 	trace_wakeup_source_deactivate(ws->name, cec);
708 
709 	split_counters(&cnt, &inpr);
710 	if (!inpr && waitqueue_active(&wakeup_count_wait_queue))
711 		wake_up(&wakeup_count_wait_queue);
712 }
713 
714 /**
715  * __pm_relax - Notify the PM core that processing of a wakeup event has ended.
716  * @ws: Wakeup source object associated with the source of the event.
717  *
718  * Call this function for wakeup events whose processing started with calling
719  * __pm_stay_awake().
720  *
721  * It is safe to call it from interrupt context.
722  */
__pm_relax(struct wakeup_source * ws)723 void __pm_relax(struct wakeup_source *ws)
724 {
725 	unsigned long flags;
726 
727 	if (!ws)
728 		return;
729 
730 	spin_lock_irqsave(&ws->lock, flags);
731 	if (ws->active)
732 		wakeup_source_deactivate(ws);
733 	spin_unlock_irqrestore(&ws->lock, flags);
734 }
735 EXPORT_SYMBOL_GPL(__pm_relax);
736 
737 /**
738  * pm_relax - Notify the PM core that processing of a wakeup event has ended.
739  * @dev: Device that signaled the event.
740  *
741  * Execute __pm_relax() for the @dev's wakeup source object.
742  */
pm_relax(struct device * dev)743 void pm_relax(struct device *dev)
744 {
745 	unsigned long flags;
746 
747 	if (!dev)
748 		return;
749 
750 	spin_lock_irqsave(&dev->power.lock, flags);
751 	__pm_relax(dev->power.wakeup);
752 	spin_unlock_irqrestore(&dev->power.lock, flags);
753 }
754 EXPORT_SYMBOL_GPL(pm_relax);
755 
756 /**
757  * pm_wakeup_timer_fn - Delayed finalization of a wakeup event.
758  * @t: timer list
759  *
760  * Call wakeup_source_deactivate() for the wakeup source whose address is stored
761  * in @data if it is currently active and its timer has not been canceled and
762  * the expiration time of the timer is not in future.
763  */
pm_wakeup_timer_fn(struct timer_list * t)764 static void pm_wakeup_timer_fn(struct timer_list *t)
765 {
766 	struct wakeup_source *ws = from_timer(ws, t, timer);
767 	unsigned long flags;
768 
769 	spin_lock_irqsave(&ws->lock, flags);
770 
771 	if (ws->active && ws->timer_expires
772 	    && time_after_eq(jiffies, ws->timer_expires)) {
773 		wakeup_source_deactivate(ws);
774 		ws->expire_count++;
775 	}
776 
777 	spin_unlock_irqrestore(&ws->lock, flags);
778 }
779 
780 /**
781  * pm_wakeup_ws_event - Notify the PM core of a wakeup event.
782  * @ws: Wakeup source object associated with the event source.
783  * @msec: Anticipated event processing time (in milliseconds).
784  * @hard: If set, abort suspends in progress and wake up from suspend-to-idle.
785  *
786  * Notify the PM core of a wakeup event whose source is @ws that will take
787  * approximately @msec milliseconds to be processed by the kernel.  If @ws is
788  * not active, activate it.  If @msec is nonzero, set up the @ws' timer to
789  * execute pm_wakeup_timer_fn() in future.
790  *
791  * It is safe to call this function from interrupt context.
792  */
pm_wakeup_ws_event(struct wakeup_source * ws,unsigned int msec,bool hard)793 void pm_wakeup_ws_event(struct wakeup_source *ws, unsigned int msec, bool hard)
794 {
795 	unsigned long flags;
796 	unsigned long expires;
797 
798 	if (!ws)
799 		return;
800 
801 	spin_lock_irqsave(&ws->lock, flags);
802 
803 	wakeup_source_report_event(ws, hard);
804 
805 	if (!msec) {
806 		wakeup_source_deactivate(ws);
807 		goto unlock;
808 	}
809 
810 	expires = jiffies + msecs_to_jiffies(msec);
811 	if (!expires)
812 		expires = 1;
813 
814 	if (!ws->timer_expires || time_after(expires, ws->timer_expires)) {
815 		mod_timer(&ws->timer, expires);
816 		ws->timer_expires = expires;
817 	}
818 
819  unlock:
820 	spin_unlock_irqrestore(&ws->lock, flags);
821 }
822 EXPORT_SYMBOL_GPL(pm_wakeup_ws_event);
823 
824 /**
825  * pm_wakeup_dev_event - Notify the PM core of a wakeup event.
826  * @dev: Device the wakeup event is related to.
827  * @msec: Anticipated event processing time (in milliseconds).
828  * @hard: If set, abort suspends in progress and wake up from suspend-to-idle.
829  *
830  * Call pm_wakeup_ws_event() for the @dev's wakeup source object.
831  */
pm_wakeup_dev_event(struct device * dev,unsigned int msec,bool hard)832 void pm_wakeup_dev_event(struct device *dev, unsigned int msec, bool hard)
833 {
834 	unsigned long flags;
835 
836 	if (!dev)
837 		return;
838 
839 	spin_lock_irqsave(&dev->power.lock, flags);
840 	pm_wakeup_ws_event(dev->power.wakeup, msec, hard);
841 	spin_unlock_irqrestore(&dev->power.lock, flags);
842 }
843 EXPORT_SYMBOL_GPL(pm_wakeup_dev_event);
844 
pm_print_active_wakeup_sources(void)845 void pm_print_active_wakeup_sources(void)
846 {
847 	struct wakeup_source *ws;
848 	int srcuidx, active = 0;
849 	struct wakeup_source *last_activity_ws = NULL;
850 
851 	srcuidx = srcu_read_lock(&wakeup_srcu);
852 	list_for_each_entry_rcu_locked(ws, &wakeup_sources, entry) {
853 		if (ws->active) {
854 			pm_pr_dbg("active wakeup source: %s\n", ws->name);
855 			active = 1;
856 		} else if (!active &&
857 			   (!last_activity_ws ||
858 			    ktime_to_ns(ws->last_time) >
859 			    ktime_to_ns(last_activity_ws->last_time))) {
860 			last_activity_ws = ws;
861 		}
862 	}
863 
864 	if (!active && last_activity_ws)
865 		pm_pr_dbg("last active wakeup source: %s\n",
866 			last_activity_ws->name);
867 	srcu_read_unlock(&wakeup_srcu, srcuidx);
868 }
869 EXPORT_SYMBOL_GPL(pm_print_active_wakeup_sources);
870 
871 /**
872  * pm_wakeup_pending - Check if power transition in progress should be aborted.
873  *
874  * Compare the current number of registered wakeup events with its preserved
875  * value from the past and return true if new wakeup events have been registered
876  * since the old value was stored.  Also return true if the current number of
877  * wakeup events being processed is different from zero.
878  */
pm_wakeup_pending(void)879 bool pm_wakeup_pending(void)
880 {
881 	unsigned long flags;
882 	bool ret = false;
883 
884 	raw_spin_lock_irqsave(&events_lock, flags);
885 	if (events_check_enabled) {
886 		unsigned int cnt, inpr;
887 
888 		split_counters(&cnt, &inpr);
889 		ret = (cnt != saved_count || inpr > 0);
890 		events_check_enabled = !ret;
891 	}
892 	raw_spin_unlock_irqrestore(&events_lock, flags);
893 
894 	if (ret) {
895 		pm_pr_dbg("Wakeup pending, aborting suspend\n");
896 		pm_print_active_wakeup_sources();
897 	}
898 
899 	return ret || atomic_read(&pm_abort_suspend) > 0;
900 }
901 EXPORT_SYMBOL_GPL(pm_wakeup_pending);
902 
pm_system_wakeup(void)903 void pm_system_wakeup(void)
904 {
905 	atomic_inc(&pm_abort_suspend);
906 	s2idle_wake();
907 }
908 EXPORT_SYMBOL_GPL(pm_system_wakeup);
909 
pm_system_cancel_wakeup(void)910 void pm_system_cancel_wakeup(void)
911 {
912 	atomic_dec_if_positive(&pm_abort_suspend);
913 }
914 
pm_wakeup_clear(unsigned int irq_number)915 void pm_wakeup_clear(unsigned int irq_number)
916 {
917 	raw_spin_lock_irq(&wakeup_irq_lock);
918 
919 	if (irq_number && wakeup_irq[0] == irq_number)
920 		wakeup_irq[0] = wakeup_irq[1];
921 	else
922 		wakeup_irq[0] = 0;
923 
924 	wakeup_irq[1] = 0;
925 
926 	raw_spin_unlock_irq(&wakeup_irq_lock);
927 
928 	if (!irq_number)
929 		atomic_set(&pm_abort_suspend, 0);
930 }
931 
pm_system_irq_wakeup(unsigned int irq_number)932 void pm_system_irq_wakeup(unsigned int irq_number)
933 {
934 	unsigned long flags;
935 
936 	raw_spin_lock_irqsave(&wakeup_irq_lock, flags);
937 
938 	if (wakeup_irq[0] == 0)
939 		wakeup_irq[0] = irq_number;
940 	else if (wakeup_irq[1] == 0)
941 		wakeup_irq[1] = irq_number;
942 	else
943 		irq_number = 0;
944 
945 	pm_pr_dbg("Triggering wakeup from IRQ %d\n", irq_number);
946 
947 	raw_spin_unlock_irqrestore(&wakeup_irq_lock, flags);
948 
949 	if (irq_number)
950 		pm_system_wakeup();
951 }
952 
pm_wakeup_irq(void)953 unsigned int pm_wakeup_irq(void)
954 {
955 	return wakeup_irq[0];
956 }
957 
958 /**
959  * pm_get_wakeup_count - Read the number of registered wakeup events.
960  * @count: Address to store the value at.
961  * @block: Whether or not to block.
962  *
963  * Store the number of registered wakeup events at the address in @count.  If
964  * @block is set, block until the current number of wakeup events being
965  * processed is zero.
966  *
967  * Return 'false' if the current number of wakeup events being processed is
968  * nonzero.  Otherwise return 'true'.
969  */
pm_get_wakeup_count(unsigned int * count,bool block)970 bool pm_get_wakeup_count(unsigned int *count, bool block)
971 {
972 	unsigned int cnt, inpr;
973 
974 	if (block) {
975 		DEFINE_WAIT(wait);
976 
977 		for (;;) {
978 			prepare_to_wait(&wakeup_count_wait_queue, &wait,
979 					TASK_INTERRUPTIBLE);
980 			split_counters(&cnt, &inpr);
981 			if (inpr == 0 || signal_pending(current))
982 				break;
983 			pm_print_active_wakeup_sources();
984 			schedule();
985 		}
986 		finish_wait(&wakeup_count_wait_queue, &wait);
987 	}
988 
989 	split_counters(&cnt, &inpr);
990 	*count = cnt;
991 	return !inpr;
992 }
993 
994 /**
995  * pm_save_wakeup_count - Save the current number of registered wakeup events.
996  * @count: Value to compare with the current number of registered wakeup events.
997  *
998  * If @count is equal to the current number of registered wakeup events and the
999  * current number of wakeup events being processed is zero, store @count as the
1000  * old number of registered wakeup events for pm_check_wakeup_events(), enable
1001  * wakeup events detection and return 'true'.  Otherwise disable wakeup events
1002  * detection and return 'false'.
1003  */
pm_save_wakeup_count(unsigned int count)1004 bool pm_save_wakeup_count(unsigned int count)
1005 {
1006 	unsigned int cnt, inpr;
1007 	unsigned long flags;
1008 
1009 	events_check_enabled = false;
1010 	raw_spin_lock_irqsave(&events_lock, flags);
1011 	split_counters(&cnt, &inpr);
1012 	if (cnt == count && inpr == 0) {
1013 		saved_count = count;
1014 		events_check_enabled = true;
1015 	}
1016 	raw_spin_unlock_irqrestore(&events_lock, flags);
1017 	return events_check_enabled;
1018 }
1019 
1020 #ifdef CONFIG_PM_AUTOSLEEP
1021 /**
1022  * pm_wakep_autosleep_enabled - Modify autosleep_enabled for all wakeup sources.
1023  * @set: Whether to set or to clear the autosleep_enabled flags.
1024  */
pm_wakep_autosleep_enabled(bool set)1025 void pm_wakep_autosleep_enabled(bool set)
1026 {
1027 	struct wakeup_source *ws;
1028 	ktime_t now = ktime_get();
1029 	int srcuidx;
1030 
1031 	srcuidx = srcu_read_lock(&wakeup_srcu);
1032 	list_for_each_entry_rcu_locked(ws, &wakeup_sources, entry) {
1033 		spin_lock_irq(&ws->lock);
1034 		if (ws->autosleep_enabled != set) {
1035 			ws->autosleep_enabled = set;
1036 			if (ws->active) {
1037 				if (set)
1038 					ws->start_prevent_time = now;
1039 				else
1040 					update_prevent_sleep_time(ws, now);
1041 			}
1042 		}
1043 		spin_unlock_irq(&ws->lock);
1044 	}
1045 	srcu_read_unlock(&wakeup_srcu, srcuidx);
1046 }
1047 #endif /* CONFIG_PM_AUTOSLEEP */
1048 
1049 /**
1050  * print_wakeup_source_stats - Print wakeup source statistics information.
1051  * @m: seq_file to print the statistics into.
1052  * @ws: Wakeup source object to print the statistics for.
1053  */
print_wakeup_source_stats(struct seq_file * m,struct wakeup_source * ws)1054 static int print_wakeup_source_stats(struct seq_file *m,
1055 				     struct wakeup_source *ws)
1056 {
1057 	unsigned long flags;
1058 	ktime_t total_time;
1059 	ktime_t max_time;
1060 	unsigned long active_count;
1061 	ktime_t active_time;
1062 	ktime_t prevent_sleep_time;
1063 
1064 	spin_lock_irqsave(&ws->lock, flags);
1065 
1066 	total_time = ws->total_time;
1067 	max_time = ws->max_time;
1068 	prevent_sleep_time = ws->prevent_sleep_time;
1069 	active_count = ws->active_count;
1070 	if (ws->active) {
1071 		ktime_t now = ktime_get();
1072 
1073 		active_time = ktime_sub(now, ws->last_time);
1074 		total_time = ktime_add(total_time, active_time);
1075 		if (active_time > max_time)
1076 			max_time = active_time;
1077 
1078 		if (ws->autosleep_enabled)
1079 			prevent_sleep_time = ktime_add(prevent_sleep_time,
1080 				ktime_sub(now, ws->start_prevent_time));
1081 	} else {
1082 		active_time = 0;
1083 	}
1084 
1085 	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",
1086 		   ws->name, active_count, ws->event_count,
1087 		   ws->wakeup_count, ws->expire_count,
1088 		   ktime_to_ms(active_time), ktime_to_ms(total_time),
1089 		   ktime_to_ms(max_time), ktime_to_ms(ws->last_time),
1090 		   ktime_to_ms(prevent_sleep_time));
1091 
1092 	spin_unlock_irqrestore(&ws->lock, flags);
1093 
1094 	return 0;
1095 }
1096 
wakeup_sources_stats_seq_start(struct seq_file * m,loff_t * pos)1097 static void *wakeup_sources_stats_seq_start(struct seq_file *m,
1098 					loff_t *pos)
1099 {
1100 	struct wakeup_source *ws;
1101 	loff_t n = *pos;
1102 	int *srcuidx = m->private;
1103 
1104 	if (n == 0) {
1105 		seq_puts(m, "name\t\tactive_count\tevent_count\twakeup_count\t"
1106 			"expire_count\tactive_since\ttotal_time\tmax_time\t"
1107 			"last_change\tprevent_suspend_time\n");
1108 	}
1109 
1110 	*srcuidx = srcu_read_lock(&wakeup_srcu);
1111 	list_for_each_entry_rcu_locked(ws, &wakeup_sources, entry) {
1112 		if (n-- <= 0)
1113 			return ws;
1114 	}
1115 
1116 	return NULL;
1117 }
1118 
wakeup_sources_stats_seq_next(struct seq_file * m,void * v,loff_t * pos)1119 static void *wakeup_sources_stats_seq_next(struct seq_file *m,
1120 					void *v, loff_t *pos)
1121 {
1122 	struct wakeup_source *ws = v;
1123 	struct wakeup_source *next_ws = NULL;
1124 
1125 	++(*pos);
1126 
1127 	list_for_each_entry_continue_rcu(ws, &wakeup_sources, entry) {
1128 		next_ws = ws;
1129 		break;
1130 	}
1131 
1132 	if (!next_ws)
1133 		print_wakeup_source_stats(m, &deleted_ws);
1134 
1135 	return next_ws;
1136 }
1137 
wakeup_sources_stats_seq_stop(struct seq_file * m,void * v)1138 static void wakeup_sources_stats_seq_stop(struct seq_file *m, void *v)
1139 {
1140 	int *srcuidx = m->private;
1141 
1142 	srcu_read_unlock(&wakeup_srcu, *srcuidx);
1143 }
1144 
1145 /**
1146  * wakeup_sources_stats_seq_show - Print wakeup sources statistics information.
1147  * @m: seq_file to print the statistics into.
1148  * @v: wakeup_source of each iteration
1149  */
wakeup_sources_stats_seq_show(struct seq_file * m,void * v)1150 static int wakeup_sources_stats_seq_show(struct seq_file *m, void *v)
1151 {
1152 	struct wakeup_source *ws = v;
1153 
1154 	print_wakeup_source_stats(m, ws);
1155 
1156 	return 0;
1157 }
1158 
1159 static const struct seq_operations wakeup_sources_stats_seq_ops = {
1160 	.start = wakeup_sources_stats_seq_start,
1161 	.next  = wakeup_sources_stats_seq_next,
1162 	.stop  = wakeup_sources_stats_seq_stop,
1163 	.show  = wakeup_sources_stats_seq_show,
1164 };
1165 
wakeup_sources_stats_open(struct inode * inode,struct file * file)1166 static int wakeup_sources_stats_open(struct inode *inode, struct file *file)
1167 {
1168 	return seq_open_private(file, &wakeup_sources_stats_seq_ops, sizeof(int));
1169 }
1170 
1171 static const struct file_operations wakeup_sources_stats_fops = {
1172 	.owner = THIS_MODULE,
1173 	.open = wakeup_sources_stats_open,
1174 	.read = seq_read,
1175 	.llseek = seq_lseek,
1176 	.release = seq_release_private,
1177 };
1178 
wakeup_sources_debugfs_init(void)1179 static int __init wakeup_sources_debugfs_init(void)
1180 {
1181 	debugfs_create_file("wakeup_sources", 0444, NULL, NULL,
1182 			    &wakeup_sources_stats_fops);
1183 	return 0;
1184 }
1185 
1186 postcore_initcall(wakeup_sources_debugfs_init);
1187