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