1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * drivers/base/power/main.c - Where the driver meets power management.
4  *
5  * Copyright (c) 2003 Patrick Mochel
6  * Copyright (c) 2003 Open Source Development Lab
7  *
8  * The driver model core calls device_pm_add() when a device is registered.
9  * This will initialize the embedded device_pm_info object in the device
10  * and add it to the list of power-controlled devices. sysfs entries for
11  * controlling device power management will also be added.
12  *
13  * A separate list is used for keeping track of power info, because the power
14  * domain dependencies may differ from the ancestral dependencies that the
15  * subsystem list maintains.
16  */
17 
18 #define pr_fmt(fmt) "PM: " fmt
19 #define dev_fmt pr_fmt
20 
21 #include <linux/device.h>
22 #include <linux/export.h>
23 #include <linux/mutex.h>
24 #include <linux/pm.h>
25 #include <linux/pm_runtime.h>
26 #include <linux/pm-trace.h>
27 #include <linux/pm_wakeirq.h>
28 #include <linux/interrupt.h>
29 #include <linux/sched.h>
30 #include <linux/sched/debug.h>
31 #include <linux/async.h>
32 #include <linux/suspend.h>
33 #include <trace/events/power.h>
34 #include <linux/cpufreq.h>
35 #include <linux/devfreq.h>
36 #include <linux/timer.h>
37 
38 #include "../base.h"
39 #include "power.h"
40 
41 typedef int (*pm_callback_t)(struct device *);
42 
43 #define list_for_each_entry_rcu_locked(pos, head, member) \
44 	list_for_each_entry_rcu(pos, head, member, \
45 			device_links_read_lock_held())
46 
47 /*
48  * The entries in the dpm_list list are in a depth first order, simply
49  * because children are guaranteed to be discovered after parents, and
50  * are inserted at the back of the list on discovery.
51  *
52  * Since device_pm_add() may be called with a device lock held,
53  * we must never try to acquire a device lock while holding
54  * dpm_list_mutex.
55  */
56 
57 LIST_HEAD(dpm_list);
58 static LIST_HEAD(dpm_prepared_list);
59 static LIST_HEAD(dpm_suspended_list);
60 static LIST_HEAD(dpm_late_early_list);
61 static LIST_HEAD(dpm_noirq_list);
62 
63 struct suspend_stats suspend_stats;
64 static DEFINE_MUTEX(dpm_list_mtx);
65 static pm_message_t pm_transition;
66 
67 static int async_error;
68 
pm_verb(int event)69 static const char *pm_verb(int event)
70 {
71 	switch (event) {
72 	case PM_EVENT_SUSPEND:
73 		return "suspend";
74 	case PM_EVENT_RESUME:
75 		return "resume";
76 	case PM_EVENT_FREEZE:
77 		return "freeze";
78 	case PM_EVENT_QUIESCE:
79 		return "quiesce";
80 	case PM_EVENT_HIBERNATE:
81 		return "hibernate";
82 	case PM_EVENT_THAW:
83 		return "thaw";
84 	case PM_EVENT_RESTORE:
85 		return "restore";
86 	case PM_EVENT_RECOVER:
87 		return "recover";
88 	default:
89 		return "(unknown PM event)";
90 	}
91 }
92 
93 /**
94  * device_pm_sleep_init - Initialize system suspend-related device fields.
95  * @dev: Device object being initialized.
96  */
device_pm_sleep_init(struct device * dev)97 void device_pm_sleep_init(struct device *dev)
98 {
99 	dev->power.is_prepared = false;
100 	dev->power.is_suspended = false;
101 	dev->power.is_noirq_suspended = false;
102 	dev->power.is_late_suspended = false;
103 	init_completion(&dev->power.completion);
104 	complete_all(&dev->power.completion);
105 	dev->power.wakeup = NULL;
106 	INIT_LIST_HEAD(&dev->power.entry);
107 }
108 
109 /**
110  * device_pm_lock - Lock the list of active devices used by the PM core.
111  */
device_pm_lock(void)112 void device_pm_lock(void)
113 {
114 	mutex_lock(&dpm_list_mtx);
115 }
116 
117 /**
118  * device_pm_unlock - Unlock the list of active devices used by the PM core.
119  */
device_pm_unlock(void)120 void device_pm_unlock(void)
121 {
122 	mutex_unlock(&dpm_list_mtx);
123 }
124 
125 /**
126  * device_pm_add - Add a device to the PM core's list of active devices.
127  * @dev: Device to add to the list.
128  */
device_pm_add(struct device * dev)129 void device_pm_add(struct device *dev)
130 {
131 	/* Skip PM setup/initialization. */
132 	if (device_pm_not_required(dev))
133 		return;
134 
135 	pr_debug("Adding info for %s:%s\n",
136 		 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
137 	device_pm_check_callbacks(dev);
138 	mutex_lock(&dpm_list_mtx);
139 	if (dev->parent && dev->parent->power.is_prepared)
140 		dev_warn(dev, "parent %s should not be sleeping\n",
141 			dev_name(dev->parent));
142 	list_add_tail(&dev->power.entry, &dpm_list);
143 	dev->power.in_dpm_list = true;
144 	mutex_unlock(&dpm_list_mtx);
145 }
146 
147 /**
148  * device_pm_remove - Remove a device from the PM core's list of active devices.
149  * @dev: Device to be removed from the list.
150  */
device_pm_remove(struct device * dev)151 void device_pm_remove(struct device *dev)
152 {
153 	if (device_pm_not_required(dev))
154 		return;
155 
156 	pr_debug("Removing info for %s:%s\n",
157 		 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
158 	complete_all(&dev->power.completion);
159 	mutex_lock(&dpm_list_mtx);
160 	list_del_init(&dev->power.entry);
161 	dev->power.in_dpm_list = false;
162 	mutex_unlock(&dpm_list_mtx);
163 	device_wakeup_disable(dev);
164 	pm_runtime_remove(dev);
165 	device_pm_check_callbacks(dev);
166 }
167 
168 /**
169  * device_pm_move_before - Move device in the PM core's list of active devices.
170  * @deva: Device to move in dpm_list.
171  * @devb: Device @deva should come before.
172  */
device_pm_move_before(struct device * deva,struct device * devb)173 void device_pm_move_before(struct device *deva, struct device *devb)
174 {
175 	pr_debug("Moving %s:%s before %s:%s\n",
176 		 deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
177 		 devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
178 	/* Delete deva from dpm_list and reinsert before devb. */
179 	list_move_tail(&deva->power.entry, &devb->power.entry);
180 }
181 
182 /**
183  * device_pm_move_after - Move device in the PM core's list of active devices.
184  * @deva: Device to move in dpm_list.
185  * @devb: Device @deva should come after.
186  */
device_pm_move_after(struct device * deva,struct device * devb)187 void device_pm_move_after(struct device *deva, struct device *devb)
188 {
189 	pr_debug("Moving %s:%s after %s:%s\n",
190 		 deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
191 		 devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
192 	/* Delete deva from dpm_list and reinsert after devb. */
193 	list_move(&deva->power.entry, &devb->power.entry);
194 }
195 
196 /**
197  * device_pm_move_last - Move device to end of the PM core's list of devices.
198  * @dev: Device to move in dpm_list.
199  */
device_pm_move_last(struct device * dev)200 void device_pm_move_last(struct device *dev)
201 {
202 	pr_debug("Moving %s:%s to end of list\n",
203 		 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
204 	list_move_tail(&dev->power.entry, &dpm_list);
205 }
206 
initcall_debug_start(struct device * dev,void * cb)207 static ktime_t initcall_debug_start(struct device *dev, void *cb)
208 {
209 	if (!pm_print_times_enabled)
210 		return 0;
211 
212 	dev_info(dev, "calling %pS @ %i, parent: %s\n", cb,
213 		 task_pid_nr(current),
214 		 dev->parent ? dev_name(dev->parent) : "none");
215 	return ktime_get();
216 }
217 
initcall_debug_report(struct device * dev,ktime_t calltime,void * cb,int error)218 static void initcall_debug_report(struct device *dev, ktime_t calltime,
219 				  void *cb, int error)
220 {
221 	ktime_t rettime;
222 
223 	if (!pm_print_times_enabled)
224 		return;
225 
226 	rettime = ktime_get();
227 	dev_info(dev, "%pS returned %d after %Ld usecs\n", cb, error,
228 		 (unsigned long long)ktime_us_delta(rettime, calltime));
229 }
230 
231 /**
232  * dpm_wait - Wait for a PM operation to complete.
233  * @dev: Device to wait for.
234  * @async: If unset, wait only if the device's power.async_suspend flag is set.
235  */
dpm_wait(struct device * dev,bool async)236 static void dpm_wait(struct device *dev, bool async)
237 {
238 	if (!dev)
239 		return;
240 
241 	if (async || (pm_async_enabled && dev->power.async_suspend))
242 		wait_for_completion(&dev->power.completion);
243 }
244 
dpm_wait_fn(struct device * dev,void * async_ptr)245 static int dpm_wait_fn(struct device *dev, void *async_ptr)
246 {
247 	dpm_wait(dev, *((bool *)async_ptr));
248 	return 0;
249 }
250 
dpm_wait_for_children(struct device * dev,bool async)251 static void dpm_wait_for_children(struct device *dev, bool async)
252 {
253        device_for_each_child(dev, &async, dpm_wait_fn);
254 }
255 
dpm_wait_for_suppliers(struct device * dev,bool async)256 static void dpm_wait_for_suppliers(struct device *dev, bool async)
257 {
258 	struct device_link *link;
259 	int idx;
260 
261 	idx = device_links_read_lock();
262 
263 	/*
264 	 * If the supplier goes away right after we've checked the link to it,
265 	 * we'll wait for its completion to change the state, but that's fine,
266 	 * because the only things that will block as a result are the SRCU
267 	 * callbacks freeing the link objects for the links in the list we're
268 	 * walking.
269 	 */
270 	list_for_each_entry_rcu_locked(link, &dev->links.suppliers, c_node)
271 		if (READ_ONCE(link->status) != DL_STATE_DORMANT)
272 			dpm_wait(link->supplier, async);
273 
274 	device_links_read_unlock(idx);
275 }
276 
dpm_wait_for_superior(struct device * dev,bool async)277 static bool dpm_wait_for_superior(struct device *dev, bool async)
278 {
279 	struct device *parent;
280 
281 	/*
282 	 * If the device is resumed asynchronously and the parent's callback
283 	 * deletes both the device and the parent itself, the parent object may
284 	 * be freed while this function is running, so avoid that by reference
285 	 * counting the parent once more unless the device has been deleted
286 	 * already (in which case return right away).
287 	 */
288 	mutex_lock(&dpm_list_mtx);
289 
290 	if (!device_pm_initialized(dev)) {
291 		mutex_unlock(&dpm_list_mtx);
292 		return false;
293 	}
294 
295 	parent = get_device(dev->parent);
296 
297 	mutex_unlock(&dpm_list_mtx);
298 
299 	dpm_wait(parent, async);
300 	put_device(parent);
301 
302 	dpm_wait_for_suppliers(dev, async);
303 
304 	/*
305 	 * If the parent's callback has deleted the device, attempting to resume
306 	 * it would be invalid, so avoid doing that then.
307 	 */
308 	return device_pm_initialized(dev);
309 }
310 
dpm_wait_for_consumers(struct device * dev,bool async)311 static void dpm_wait_for_consumers(struct device *dev, bool async)
312 {
313 	struct device_link *link;
314 	int idx;
315 
316 	idx = device_links_read_lock();
317 
318 	/*
319 	 * The status of a device link can only be changed from "dormant" by a
320 	 * probe, but that cannot happen during system suspend/resume.  In
321 	 * theory it can change to "dormant" at that time, but then it is
322 	 * reasonable to wait for the target device anyway (eg. if it goes
323 	 * away, it's better to wait for it to go away completely and then
324 	 * continue instead of trying to continue in parallel with its
325 	 * unregistration).
326 	 */
327 	list_for_each_entry_rcu_locked(link, &dev->links.consumers, s_node)
328 		if (READ_ONCE(link->status) != DL_STATE_DORMANT)
329 			dpm_wait(link->consumer, async);
330 
331 	device_links_read_unlock(idx);
332 }
333 
dpm_wait_for_subordinate(struct device * dev,bool async)334 static void dpm_wait_for_subordinate(struct device *dev, bool async)
335 {
336 	dpm_wait_for_children(dev, async);
337 	dpm_wait_for_consumers(dev, async);
338 }
339 
340 /**
341  * pm_op - Return the PM operation appropriate for given PM event.
342  * @ops: PM operations to choose from.
343  * @state: PM transition of the system being carried out.
344  */
pm_op(const struct dev_pm_ops * ops,pm_message_t state)345 static pm_callback_t pm_op(const struct dev_pm_ops *ops, pm_message_t state)
346 {
347 	switch (state.event) {
348 #ifdef CONFIG_SUSPEND
349 	case PM_EVENT_SUSPEND:
350 		return ops->suspend;
351 	case PM_EVENT_RESUME:
352 		return ops->resume;
353 #endif /* CONFIG_SUSPEND */
354 #ifdef CONFIG_HIBERNATE_CALLBACKS
355 	case PM_EVENT_FREEZE:
356 	case PM_EVENT_QUIESCE:
357 		return ops->freeze;
358 	case PM_EVENT_HIBERNATE:
359 		return ops->poweroff;
360 	case PM_EVENT_THAW:
361 	case PM_EVENT_RECOVER:
362 		return ops->thaw;
363 	case PM_EVENT_RESTORE:
364 		return ops->restore;
365 #endif /* CONFIG_HIBERNATE_CALLBACKS */
366 	}
367 
368 	return NULL;
369 }
370 
371 /**
372  * pm_late_early_op - Return the PM operation appropriate for given PM event.
373  * @ops: PM operations to choose from.
374  * @state: PM transition of the system being carried out.
375  *
376  * Runtime PM is disabled for @dev while this function is being executed.
377  */
pm_late_early_op(const struct dev_pm_ops * ops,pm_message_t state)378 static pm_callback_t pm_late_early_op(const struct dev_pm_ops *ops,
379 				      pm_message_t state)
380 {
381 	switch (state.event) {
382 #ifdef CONFIG_SUSPEND
383 	case PM_EVENT_SUSPEND:
384 		return ops->suspend_late;
385 	case PM_EVENT_RESUME:
386 		return ops->resume_early;
387 #endif /* CONFIG_SUSPEND */
388 #ifdef CONFIG_HIBERNATE_CALLBACKS
389 	case PM_EVENT_FREEZE:
390 	case PM_EVENT_QUIESCE:
391 		return ops->freeze_late;
392 	case PM_EVENT_HIBERNATE:
393 		return ops->poweroff_late;
394 	case PM_EVENT_THAW:
395 	case PM_EVENT_RECOVER:
396 		return ops->thaw_early;
397 	case PM_EVENT_RESTORE:
398 		return ops->restore_early;
399 #endif /* CONFIG_HIBERNATE_CALLBACKS */
400 	}
401 
402 	return NULL;
403 }
404 
405 /**
406  * pm_noirq_op - Return the PM operation appropriate for given PM event.
407  * @ops: PM operations to choose from.
408  * @state: PM transition of the system being carried out.
409  *
410  * The driver of @dev will not receive interrupts while this function is being
411  * executed.
412  */
pm_noirq_op(const struct dev_pm_ops * ops,pm_message_t state)413 static pm_callback_t pm_noirq_op(const struct dev_pm_ops *ops, pm_message_t state)
414 {
415 	switch (state.event) {
416 #ifdef CONFIG_SUSPEND
417 	case PM_EVENT_SUSPEND:
418 		return ops->suspend_noirq;
419 	case PM_EVENT_RESUME:
420 		return ops->resume_noirq;
421 #endif /* CONFIG_SUSPEND */
422 #ifdef CONFIG_HIBERNATE_CALLBACKS
423 	case PM_EVENT_FREEZE:
424 	case PM_EVENT_QUIESCE:
425 		return ops->freeze_noirq;
426 	case PM_EVENT_HIBERNATE:
427 		return ops->poweroff_noirq;
428 	case PM_EVENT_THAW:
429 	case PM_EVENT_RECOVER:
430 		return ops->thaw_noirq;
431 	case PM_EVENT_RESTORE:
432 		return ops->restore_noirq;
433 #endif /* CONFIG_HIBERNATE_CALLBACKS */
434 	}
435 
436 	return NULL;
437 }
438 
pm_dev_dbg(struct device * dev,pm_message_t state,const char * info)439 static void pm_dev_dbg(struct device *dev, pm_message_t state, const char *info)
440 {
441 	dev_dbg(dev, "%s%s%s driver flags: %x\n", info, pm_verb(state.event),
442 		((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
443 		", may wakeup" : "", dev->power.driver_flags);
444 }
445 
pm_dev_err(struct device * dev,pm_message_t state,const char * info,int error)446 static void pm_dev_err(struct device *dev, pm_message_t state, const char *info,
447 			int error)
448 {
449 	dev_err(dev, "failed to %s%s: error %d\n", pm_verb(state.event), info,
450 		error);
451 }
452 
dpm_show_time(ktime_t starttime,pm_message_t state,int error,const char * info)453 static void dpm_show_time(ktime_t starttime, pm_message_t state, int error,
454 			  const char *info)
455 {
456 	ktime_t calltime;
457 	u64 usecs64;
458 	int usecs;
459 
460 	calltime = ktime_get();
461 	usecs64 = ktime_to_ns(ktime_sub(calltime, starttime));
462 	do_div(usecs64, NSEC_PER_USEC);
463 	usecs = usecs64;
464 	if (usecs == 0)
465 		usecs = 1;
466 
467 	pm_pr_dbg("%s%s%s of devices %s after %ld.%03ld msecs\n",
468 		  info ?: "", info ? " " : "", pm_verb(state.event),
469 		  error ? "aborted" : "complete",
470 		  usecs / USEC_PER_MSEC, usecs % USEC_PER_MSEC);
471 }
472 
dpm_run_callback(pm_callback_t cb,struct device * dev,pm_message_t state,const char * info)473 static int dpm_run_callback(pm_callback_t cb, struct device *dev,
474 			    pm_message_t state, const char *info)
475 {
476 	ktime_t calltime;
477 	int error;
478 
479 	if (!cb)
480 		return 0;
481 
482 	calltime = initcall_debug_start(dev, cb);
483 
484 	pm_dev_dbg(dev, state, info);
485 	trace_device_pm_callback_start(dev, info, state.event);
486 	error = cb(dev);
487 	trace_device_pm_callback_end(dev, error);
488 	suspend_report_result(dev, cb, error);
489 
490 	initcall_debug_report(dev, calltime, cb, error);
491 
492 	return error;
493 }
494 
495 #ifdef CONFIG_DPM_WATCHDOG
496 struct dpm_watchdog {
497 	struct device		*dev;
498 	struct task_struct	*tsk;
499 	struct timer_list	timer;
500 };
501 
502 #define DECLARE_DPM_WATCHDOG_ON_STACK(wd) \
503 	struct dpm_watchdog wd
504 
505 /**
506  * dpm_watchdog_handler - Driver suspend / resume watchdog handler.
507  * @t: The timer that PM watchdog depends on.
508  *
509  * Called when a driver has timed out suspending or resuming.
510  * There's not much we can do here to recover so panic() to
511  * capture a crash-dump in pstore.
512  */
dpm_watchdog_handler(struct timer_list * t)513 static void dpm_watchdog_handler(struct timer_list *t)
514 {
515 	struct dpm_watchdog *wd = from_timer(wd, t, timer);
516 
517 	dev_emerg(wd->dev, "**** DPM device timeout ****\n");
518 	show_stack(wd->tsk, NULL, KERN_EMERG);
519 	panic("%s %s: unrecoverable failure\n",
520 		dev_driver_string(wd->dev), dev_name(wd->dev));
521 }
522 
523 /**
524  * dpm_watchdog_set - Enable pm watchdog for given device.
525  * @wd: Watchdog. Must be allocated on the stack.
526  * @dev: Device to handle.
527  */
dpm_watchdog_set(struct dpm_watchdog * wd,struct device * dev)528 static void dpm_watchdog_set(struct dpm_watchdog *wd, struct device *dev)
529 {
530 	struct timer_list *timer = &wd->timer;
531 
532 	wd->dev = dev;
533 	wd->tsk = current;
534 
535 	timer_setup_on_stack(timer, dpm_watchdog_handler, 0);
536 	/* use same timeout value for both suspend and resume */
537 	timer->expires = jiffies + HZ * CONFIG_DPM_WATCHDOG_TIMEOUT;
538 	add_timer(timer);
539 }
540 
541 /**
542  * dpm_watchdog_clear - Disable suspend/resume watchdog.
543  * @wd: Watchdog to disable.
544  */
dpm_watchdog_clear(struct dpm_watchdog * wd)545 static void dpm_watchdog_clear(struct dpm_watchdog *wd)
546 {
547 	struct timer_list *timer = &wd->timer;
548 
549 	del_timer_sync(timer);
550 	destroy_timer_on_stack(timer);
551 }
552 #else
553 #define DECLARE_DPM_WATCHDOG_ON_STACK(wd)
554 #define dpm_watchdog_set(x, y)
555 #define dpm_watchdog_clear(x)
556 #endif
557 
558 /*------------------------- Resume routines -------------------------*/
559 
560 /**
561  * dev_pm_skip_resume - System-wide device resume optimization check.
562  * @dev: Target device.
563  *
564  * Return:
565  * - %false if the transition under way is RESTORE.
566  * - Return value of dev_pm_skip_suspend() if the transition under way is THAW.
567  * - The logical negation of %power.must_resume otherwise (that is, when the
568  *   transition under way is RESUME).
569  */
dev_pm_skip_resume(struct device * dev)570 bool dev_pm_skip_resume(struct device *dev)
571 {
572 	if (pm_transition.event == PM_EVENT_RESTORE)
573 		return false;
574 
575 	if (pm_transition.event == PM_EVENT_THAW)
576 		return dev_pm_skip_suspend(dev);
577 
578 	return !dev->power.must_resume;
579 }
580 
581 /**
582  * device_resume_noirq - Execute a "noirq resume" callback for given device.
583  * @dev: Device to handle.
584  * @state: PM transition of the system being carried out.
585  * @async: If true, the device is being resumed asynchronously.
586  *
587  * The driver of @dev will not receive interrupts while this function is being
588  * executed.
589  */
device_resume_noirq(struct device * dev,pm_message_t state,bool async)590 static int device_resume_noirq(struct device *dev, pm_message_t state, bool async)
591 {
592 	pm_callback_t callback = NULL;
593 	const char *info = NULL;
594 	bool skip_resume;
595 	int error = 0;
596 
597 	TRACE_DEVICE(dev);
598 	TRACE_RESUME(0);
599 
600 	if (dev->power.syscore || dev->power.direct_complete)
601 		goto Out;
602 
603 	if (!dev->power.is_noirq_suspended)
604 		goto Out;
605 
606 	if (!dpm_wait_for_superior(dev, async))
607 		goto Out;
608 
609 	skip_resume = dev_pm_skip_resume(dev);
610 	/*
611 	 * If the driver callback is skipped below or by the middle layer
612 	 * callback and device_resume_early() also skips the driver callback for
613 	 * this device later, it needs to appear as "suspended" to PM-runtime,
614 	 * so change its status accordingly.
615 	 *
616 	 * Otherwise, the device is going to be resumed, so set its PM-runtime
617 	 * status to "active", but do that only if DPM_FLAG_SMART_SUSPEND is set
618 	 * to avoid confusing drivers that don't use it.
619 	 */
620 	if (skip_resume)
621 		pm_runtime_set_suspended(dev);
622 	else if (dev_pm_skip_suspend(dev))
623 		pm_runtime_set_active(dev);
624 
625 	if (dev->pm_domain) {
626 		info = "noirq power domain ";
627 		callback = pm_noirq_op(&dev->pm_domain->ops, state);
628 	} else if (dev->type && dev->type->pm) {
629 		info = "noirq type ";
630 		callback = pm_noirq_op(dev->type->pm, state);
631 	} else if (dev->class && dev->class->pm) {
632 		info = "noirq class ";
633 		callback = pm_noirq_op(dev->class->pm, state);
634 	} else if (dev->bus && dev->bus->pm) {
635 		info = "noirq bus ";
636 		callback = pm_noirq_op(dev->bus->pm, state);
637 	}
638 	if (callback)
639 		goto Run;
640 
641 	if (skip_resume)
642 		goto Skip;
643 
644 	if (dev->driver && dev->driver->pm) {
645 		info = "noirq driver ";
646 		callback = pm_noirq_op(dev->driver->pm, state);
647 	}
648 
649 Run:
650 	error = dpm_run_callback(callback, dev, state, info);
651 
652 Skip:
653 	dev->power.is_noirq_suspended = false;
654 
655 Out:
656 	complete_all(&dev->power.completion);
657 	TRACE_RESUME(error);
658 	return error;
659 }
660 
is_async(struct device * dev)661 static bool is_async(struct device *dev)
662 {
663 	return dev->power.async_suspend && pm_async_enabled
664 		&& !pm_trace_is_enabled();
665 }
666 
dpm_async_fn(struct device * dev,async_func_t func)667 static bool dpm_async_fn(struct device *dev, async_func_t func)
668 {
669 	reinit_completion(&dev->power.completion);
670 
671 	if (is_async(dev)) {
672 		get_device(dev);
673 		async_schedule_dev(func, dev);
674 		return true;
675 	}
676 
677 	return false;
678 }
679 
async_resume_noirq(void * data,async_cookie_t cookie)680 static void async_resume_noirq(void *data, async_cookie_t cookie)
681 {
682 	struct device *dev = (struct device *)data;
683 	int error;
684 
685 	error = device_resume_noirq(dev, pm_transition, true);
686 	if (error)
687 		pm_dev_err(dev, pm_transition, " async", error);
688 
689 	put_device(dev);
690 }
691 
dpm_noirq_resume_devices(pm_message_t state)692 static void dpm_noirq_resume_devices(pm_message_t state)
693 {
694 	struct device *dev;
695 	ktime_t starttime = ktime_get();
696 
697 	trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, true);
698 	mutex_lock(&dpm_list_mtx);
699 	pm_transition = state;
700 
701 	/*
702 	 * Advanced the async threads upfront,
703 	 * in case the starting of async threads is
704 	 * delayed by non-async resuming devices.
705 	 */
706 	list_for_each_entry(dev, &dpm_noirq_list, power.entry)
707 		dpm_async_fn(dev, async_resume_noirq);
708 
709 	while (!list_empty(&dpm_noirq_list)) {
710 		dev = to_device(dpm_noirq_list.next);
711 		get_device(dev);
712 		list_move_tail(&dev->power.entry, &dpm_late_early_list);
713 
714 		mutex_unlock(&dpm_list_mtx);
715 
716 		if (!is_async(dev)) {
717 			int error;
718 
719 			error = device_resume_noirq(dev, state, false);
720 			if (error) {
721 				suspend_stats.failed_resume_noirq++;
722 				dpm_save_failed_step(SUSPEND_RESUME_NOIRQ);
723 				dpm_save_failed_dev(dev_name(dev));
724 				pm_dev_err(dev, state, " noirq", error);
725 			}
726 		}
727 
728 		put_device(dev);
729 
730 		mutex_lock(&dpm_list_mtx);
731 	}
732 	mutex_unlock(&dpm_list_mtx);
733 	async_synchronize_full();
734 	dpm_show_time(starttime, state, 0, "noirq");
735 	trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, false);
736 }
737 
738 /**
739  * dpm_resume_noirq - Execute "noirq resume" callbacks for all devices.
740  * @state: PM transition of the system being carried out.
741  *
742  * Invoke the "noirq" resume callbacks for all devices in dpm_noirq_list and
743  * allow device drivers' interrupt handlers to be called.
744  */
dpm_resume_noirq(pm_message_t state)745 void dpm_resume_noirq(pm_message_t state)
746 {
747 	dpm_noirq_resume_devices(state);
748 
749 	resume_device_irqs();
750 	device_wakeup_disarm_wake_irqs();
751 }
752 
753 /**
754  * device_resume_early - Execute an "early resume" callback for given device.
755  * @dev: Device to handle.
756  * @state: PM transition of the system being carried out.
757  * @async: If true, the device is being resumed asynchronously.
758  *
759  * Runtime PM is disabled for @dev while this function is being executed.
760  */
device_resume_early(struct device * dev,pm_message_t state,bool async)761 static int device_resume_early(struct device *dev, pm_message_t state, bool async)
762 {
763 	pm_callback_t callback = NULL;
764 	const char *info = NULL;
765 	int error = 0;
766 
767 	TRACE_DEVICE(dev);
768 	TRACE_RESUME(0);
769 
770 	if (dev->power.syscore || dev->power.direct_complete)
771 		goto Out;
772 
773 	if (!dev->power.is_late_suspended)
774 		goto Out;
775 
776 	if (!dpm_wait_for_superior(dev, async))
777 		goto Out;
778 
779 	if (dev->pm_domain) {
780 		info = "early power domain ";
781 		callback = pm_late_early_op(&dev->pm_domain->ops, state);
782 	} else if (dev->type && dev->type->pm) {
783 		info = "early type ";
784 		callback = pm_late_early_op(dev->type->pm, state);
785 	} else if (dev->class && dev->class->pm) {
786 		info = "early class ";
787 		callback = pm_late_early_op(dev->class->pm, state);
788 	} else if (dev->bus && dev->bus->pm) {
789 		info = "early bus ";
790 		callback = pm_late_early_op(dev->bus->pm, state);
791 	}
792 	if (callback)
793 		goto Run;
794 
795 	if (dev_pm_skip_resume(dev))
796 		goto Skip;
797 
798 	if (dev->driver && dev->driver->pm) {
799 		info = "early driver ";
800 		callback = pm_late_early_op(dev->driver->pm, state);
801 	}
802 
803 Run:
804 	error = dpm_run_callback(callback, dev, state, info);
805 
806 Skip:
807 	dev->power.is_late_suspended = false;
808 
809 Out:
810 	TRACE_RESUME(error);
811 
812 	pm_runtime_enable(dev);
813 	complete_all(&dev->power.completion);
814 	return error;
815 }
816 
async_resume_early(void * data,async_cookie_t cookie)817 static void async_resume_early(void *data, async_cookie_t cookie)
818 {
819 	struct device *dev = (struct device *)data;
820 	int error;
821 
822 	error = device_resume_early(dev, pm_transition, true);
823 	if (error)
824 		pm_dev_err(dev, pm_transition, " async", error);
825 
826 	put_device(dev);
827 }
828 
829 /**
830  * dpm_resume_early - Execute "early resume" callbacks for all devices.
831  * @state: PM transition of the system being carried out.
832  */
dpm_resume_early(pm_message_t state)833 void dpm_resume_early(pm_message_t state)
834 {
835 	struct device *dev;
836 	ktime_t starttime = ktime_get();
837 
838 	trace_suspend_resume(TPS("dpm_resume_early"), state.event, true);
839 	mutex_lock(&dpm_list_mtx);
840 	pm_transition = state;
841 
842 	/*
843 	 * Advanced the async threads upfront,
844 	 * in case the starting of async threads is
845 	 * delayed by non-async resuming devices.
846 	 */
847 	list_for_each_entry(dev, &dpm_late_early_list, power.entry)
848 		dpm_async_fn(dev, async_resume_early);
849 
850 	while (!list_empty(&dpm_late_early_list)) {
851 		dev = to_device(dpm_late_early_list.next);
852 		get_device(dev);
853 		list_move_tail(&dev->power.entry, &dpm_suspended_list);
854 
855 		mutex_unlock(&dpm_list_mtx);
856 
857 		if (!is_async(dev)) {
858 			int error;
859 
860 			error = device_resume_early(dev, state, false);
861 			if (error) {
862 				suspend_stats.failed_resume_early++;
863 				dpm_save_failed_step(SUSPEND_RESUME_EARLY);
864 				dpm_save_failed_dev(dev_name(dev));
865 				pm_dev_err(dev, state, " early", error);
866 			}
867 		}
868 
869 		put_device(dev);
870 
871 		mutex_lock(&dpm_list_mtx);
872 	}
873 	mutex_unlock(&dpm_list_mtx);
874 	async_synchronize_full();
875 	dpm_show_time(starttime, state, 0, "early");
876 	trace_suspend_resume(TPS("dpm_resume_early"), state.event, false);
877 }
878 
879 /**
880  * dpm_resume_start - Execute "noirq" and "early" device callbacks.
881  * @state: PM transition of the system being carried out.
882  */
dpm_resume_start(pm_message_t state)883 void dpm_resume_start(pm_message_t state)
884 {
885 	dpm_resume_noirq(state);
886 	dpm_resume_early(state);
887 }
888 EXPORT_SYMBOL_GPL(dpm_resume_start);
889 
890 /**
891  * device_resume - Execute "resume" callbacks for given device.
892  * @dev: Device to handle.
893  * @state: PM transition of the system being carried out.
894  * @async: If true, the device is being resumed asynchronously.
895  */
device_resume(struct device * dev,pm_message_t state,bool async)896 static int device_resume(struct device *dev, pm_message_t state, bool async)
897 {
898 	pm_callback_t callback = NULL;
899 	const char *info = NULL;
900 	int error = 0;
901 	DECLARE_DPM_WATCHDOG_ON_STACK(wd);
902 
903 	TRACE_DEVICE(dev);
904 	TRACE_RESUME(0);
905 
906 	if (dev->power.syscore)
907 		goto Complete;
908 
909 	if (dev->power.direct_complete) {
910 		/* Match the pm_runtime_disable() in __device_suspend(). */
911 		pm_runtime_enable(dev);
912 		goto Complete;
913 	}
914 
915 	if (!dpm_wait_for_superior(dev, async))
916 		goto Complete;
917 
918 	dpm_watchdog_set(&wd, dev);
919 	device_lock(dev);
920 
921 	/*
922 	 * This is a fib.  But we'll allow new children to be added below
923 	 * a resumed device, even if the device hasn't been completed yet.
924 	 */
925 	dev->power.is_prepared = false;
926 
927 	if (!dev->power.is_suspended)
928 		goto Unlock;
929 
930 	if (dev->pm_domain) {
931 		info = "power domain ";
932 		callback = pm_op(&dev->pm_domain->ops, state);
933 		goto Driver;
934 	}
935 
936 	if (dev->type && dev->type->pm) {
937 		info = "type ";
938 		callback = pm_op(dev->type->pm, state);
939 		goto Driver;
940 	}
941 
942 	if (dev->class && dev->class->pm) {
943 		info = "class ";
944 		callback = pm_op(dev->class->pm, state);
945 		goto Driver;
946 	}
947 
948 	if (dev->bus) {
949 		if (dev->bus->pm) {
950 			info = "bus ";
951 			callback = pm_op(dev->bus->pm, state);
952 		} else if (dev->bus->resume) {
953 			info = "legacy bus ";
954 			callback = dev->bus->resume;
955 			goto End;
956 		}
957 	}
958 
959  Driver:
960 	if (!callback && dev->driver && dev->driver->pm) {
961 		info = "driver ";
962 		callback = pm_op(dev->driver->pm, state);
963 	}
964 
965  End:
966 	error = dpm_run_callback(callback, dev, state, info);
967 	dev->power.is_suspended = false;
968 
969  Unlock:
970 	device_unlock(dev);
971 	dpm_watchdog_clear(&wd);
972 
973  Complete:
974 	complete_all(&dev->power.completion);
975 
976 	TRACE_RESUME(error);
977 
978 	return error;
979 }
980 
async_resume(void * data,async_cookie_t cookie)981 static void async_resume(void *data, async_cookie_t cookie)
982 {
983 	struct device *dev = (struct device *)data;
984 	int error;
985 
986 	error = device_resume(dev, pm_transition, true);
987 	if (error)
988 		pm_dev_err(dev, pm_transition, " async", error);
989 	put_device(dev);
990 }
991 
992 /**
993  * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
994  * @state: PM transition of the system being carried out.
995  *
996  * Execute the appropriate "resume" callback for all devices whose status
997  * indicates that they are suspended.
998  */
dpm_resume(pm_message_t state)999 void dpm_resume(pm_message_t state)
1000 {
1001 	struct device *dev;
1002 	ktime_t starttime = ktime_get();
1003 
1004 	trace_suspend_resume(TPS("dpm_resume"), state.event, true);
1005 	might_sleep();
1006 
1007 	mutex_lock(&dpm_list_mtx);
1008 	pm_transition = state;
1009 	async_error = 0;
1010 
1011 	list_for_each_entry(dev, &dpm_suspended_list, power.entry)
1012 		dpm_async_fn(dev, async_resume);
1013 
1014 	while (!list_empty(&dpm_suspended_list)) {
1015 		dev = to_device(dpm_suspended_list.next);
1016 		get_device(dev);
1017 		if (!is_async(dev)) {
1018 			int error;
1019 
1020 			mutex_unlock(&dpm_list_mtx);
1021 
1022 			error = device_resume(dev, state, false);
1023 			if (error) {
1024 				suspend_stats.failed_resume++;
1025 				dpm_save_failed_step(SUSPEND_RESUME);
1026 				dpm_save_failed_dev(dev_name(dev));
1027 				pm_dev_err(dev, state, "", error);
1028 			}
1029 
1030 			mutex_lock(&dpm_list_mtx);
1031 		}
1032 		if (!list_empty(&dev->power.entry))
1033 			list_move_tail(&dev->power.entry, &dpm_prepared_list);
1034 
1035 		mutex_unlock(&dpm_list_mtx);
1036 
1037 		put_device(dev);
1038 
1039 		mutex_lock(&dpm_list_mtx);
1040 	}
1041 	mutex_unlock(&dpm_list_mtx);
1042 	async_synchronize_full();
1043 	dpm_show_time(starttime, state, 0, NULL);
1044 
1045 	cpufreq_resume();
1046 	devfreq_resume();
1047 	trace_suspend_resume(TPS("dpm_resume"), state.event, false);
1048 }
1049 
1050 /**
1051  * device_complete - Complete a PM transition for given device.
1052  * @dev: Device to handle.
1053  * @state: PM transition of the system being carried out.
1054  */
device_complete(struct device * dev,pm_message_t state)1055 static void device_complete(struct device *dev, pm_message_t state)
1056 {
1057 	void (*callback)(struct device *) = NULL;
1058 	const char *info = NULL;
1059 
1060 	if (dev->power.syscore)
1061 		goto out;
1062 
1063 	device_lock(dev);
1064 
1065 	if (dev->pm_domain) {
1066 		info = "completing power domain ";
1067 		callback = dev->pm_domain->ops.complete;
1068 	} else if (dev->type && dev->type->pm) {
1069 		info = "completing type ";
1070 		callback = dev->type->pm->complete;
1071 	} else if (dev->class && dev->class->pm) {
1072 		info = "completing class ";
1073 		callback = dev->class->pm->complete;
1074 	} else if (dev->bus && dev->bus->pm) {
1075 		info = "completing bus ";
1076 		callback = dev->bus->pm->complete;
1077 	}
1078 
1079 	if (!callback && dev->driver && dev->driver->pm) {
1080 		info = "completing driver ";
1081 		callback = dev->driver->pm->complete;
1082 	}
1083 
1084 	if (callback) {
1085 		pm_dev_dbg(dev, state, info);
1086 		callback(dev);
1087 	}
1088 
1089 	device_unlock(dev);
1090 
1091 out:
1092 	pm_runtime_put(dev);
1093 }
1094 
1095 /**
1096  * dpm_complete - Complete a PM transition for all non-sysdev devices.
1097  * @state: PM transition of the system being carried out.
1098  *
1099  * Execute the ->complete() callbacks for all devices whose PM status is not
1100  * DPM_ON (this allows new devices to be registered).
1101  */
dpm_complete(pm_message_t state)1102 void dpm_complete(pm_message_t state)
1103 {
1104 	struct list_head list;
1105 
1106 	trace_suspend_resume(TPS("dpm_complete"), state.event, true);
1107 	might_sleep();
1108 
1109 	INIT_LIST_HEAD(&list);
1110 	mutex_lock(&dpm_list_mtx);
1111 	while (!list_empty(&dpm_prepared_list)) {
1112 		struct device *dev = to_device(dpm_prepared_list.prev);
1113 
1114 		get_device(dev);
1115 		dev->power.is_prepared = false;
1116 		list_move(&dev->power.entry, &list);
1117 
1118 		mutex_unlock(&dpm_list_mtx);
1119 
1120 		trace_device_pm_callback_start(dev, "", state.event);
1121 		device_complete(dev, state);
1122 		trace_device_pm_callback_end(dev, 0);
1123 
1124 		put_device(dev);
1125 
1126 		mutex_lock(&dpm_list_mtx);
1127 	}
1128 	list_splice(&list, &dpm_list);
1129 	mutex_unlock(&dpm_list_mtx);
1130 
1131 	/* Allow device probing and trigger re-probing of deferred devices */
1132 	device_unblock_probing();
1133 	trace_suspend_resume(TPS("dpm_complete"), state.event, false);
1134 }
1135 
1136 /**
1137  * dpm_resume_end - Execute "resume" callbacks and complete system transition.
1138  * @state: PM transition of the system being carried out.
1139  *
1140  * Execute "resume" callbacks for all devices and complete the PM transition of
1141  * the system.
1142  */
dpm_resume_end(pm_message_t state)1143 void dpm_resume_end(pm_message_t state)
1144 {
1145 	dpm_resume(state);
1146 	dpm_complete(state);
1147 }
1148 EXPORT_SYMBOL_GPL(dpm_resume_end);
1149 
1150 
1151 /*------------------------- Suspend routines -------------------------*/
1152 
1153 /**
1154  * resume_event - Return a "resume" message for given "suspend" sleep state.
1155  * @sleep_state: PM message representing a sleep state.
1156  *
1157  * Return a PM message representing the resume event corresponding to given
1158  * sleep state.
1159  */
resume_event(pm_message_t sleep_state)1160 static pm_message_t resume_event(pm_message_t sleep_state)
1161 {
1162 	switch (sleep_state.event) {
1163 	case PM_EVENT_SUSPEND:
1164 		return PMSG_RESUME;
1165 	case PM_EVENT_FREEZE:
1166 	case PM_EVENT_QUIESCE:
1167 		return PMSG_RECOVER;
1168 	case PM_EVENT_HIBERNATE:
1169 		return PMSG_RESTORE;
1170 	}
1171 	return PMSG_ON;
1172 }
1173 
dpm_superior_set_must_resume(struct device * dev)1174 static void dpm_superior_set_must_resume(struct device *dev)
1175 {
1176 	struct device_link *link;
1177 	int idx;
1178 
1179 	if (dev->parent)
1180 		dev->parent->power.must_resume = true;
1181 
1182 	idx = device_links_read_lock();
1183 
1184 	list_for_each_entry_rcu_locked(link, &dev->links.suppliers, c_node)
1185 		link->supplier->power.must_resume = true;
1186 
1187 	device_links_read_unlock(idx);
1188 }
1189 
1190 /**
1191  * __device_suspend_noirq - Execute a "noirq suspend" callback for given device.
1192  * @dev: Device to handle.
1193  * @state: PM transition of the system being carried out.
1194  * @async: If true, the device is being suspended asynchronously.
1195  *
1196  * The driver of @dev will not receive interrupts while this function is being
1197  * executed.
1198  */
__device_suspend_noirq(struct device * dev,pm_message_t state,bool async)1199 static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool async)
1200 {
1201 	pm_callback_t callback = NULL;
1202 	const char *info = NULL;
1203 	int error = 0;
1204 
1205 	TRACE_DEVICE(dev);
1206 	TRACE_SUSPEND(0);
1207 
1208 	dpm_wait_for_subordinate(dev, async);
1209 
1210 	if (async_error)
1211 		goto Complete;
1212 
1213 	if (dev->power.syscore || dev->power.direct_complete)
1214 		goto Complete;
1215 
1216 	if (dev->pm_domain) {
1217 		info = "noirq power domain ";
1218 		callback = pm_noirq_op(&dev->pm_domain->ops, state);
1219 	} else if (dev->type && dev->type->pm) {
1220 		info = "noirq type ";
1221 		callback = pm_noirq_op(dev->type->pm, state);
1222 	} else if (dev->class && dev->class->pm) {
1223 		info = "noirq class ";
1224 		callback = pm_noirq_op(dev->class->pm, state);
1225 	} else if (dev->bus && dev->bus->pm) {
1226 		info = "noirq bus ";
1227 		callback = pm_noirq_op(dev->bus->pm, state);
1228 	}
1229 	if (callback)
1230 		goto Run;
1231 
1232 	if (dev_pm_skip_suspend(dev))
1233 		goto Skip;
1234 
1235 	if (dev->driver && dev->driver->pm) {
1236 		info = "noirq driver ";
1237 		callback = pm_noirq_op(dev->driver->pm, state);
1238 	}
1239 
1240 Run:
1241 	error = dpm_run_callback(callback, dev, state, info);
1242 	if (error) {
1243 		async_error = error;
1244 		goto Complete;
1245 	}
1246 
1247 Skip:
1248 	dev->power.is_noirq_suspended = true;
1249 
1250 	/*
1251 	 * Skipping the resume of devices that were in use right before the
1252 	 * system suspend (as indicated by their PM-runtime usage counters)
1253 	 * would be suboptimal.  Also resume them if doing that is not allowed
1254 	 * to be skipped.
1255 	 */
1256 	if (atomic_read(&dev->power.usage_count) > 1 ||
1257 	    !(dev_pm_test_driver_flags(dev, DPM_FLAG_MAY_SKIP_RESUME) &&
1258 	      dev->power.may_skip_resume))
1259 		dev->power.must_resume = true;
1260 
1261 	if (dev->power.must_resume)
1262 		dpm_superior_set_must_resume(dev);
1263 
1264 Complete:
1265 	complete_all(&dev->power.completion);
1266 	TRACE_SUSPEND(error);
1267 	return error;
1268 }
1269 
async_suspend_noirq(void * data,async_cookie_t cookie)1270 static void async_suspend_noirq(void *data, async_cookie_t cookie)
1271 {
1272 	struct device *dev = (struct device *)data;
1273 	int error;
1274 
1275 	error = __device_suspend_noirq(dev, pm_transition, true);
1276 	if (error) {
1277 		dpm_save_failed_dev(dev_name(dev));
1278 		pm_dev_err(dev, pm_transition, " async", error);
1279 	}
1280 
1281 	put_device(dev);
1282 }
1283 
device_suspend_noirq(struct device * dev)1284 static int device_suspend_noirq(struct device *dev)
1285 {
1286 	if (dpm_async_fn(dev, async_suspend_noirq))
1287 		return 0;
1288 
1289 	return __device_suspend_noirq(dev, pm_transition, false);
1290 }
1291 
dpm_noirq_suspend_devices(pm_message_t state)1292 static int dpm_noirq_suspend_devices(pm_message_t state)
1293 {
1294 	ktime_t starttime = ktime_get();
1295 	int error = 0;
1296 
1297 	trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, true);
1298 	mutex_lock(&dpm_list_mtx);
1299 	pm_transition = state;
1300 	async_error = 0;
1301 
1302 	while (!list_empty(&dpm_late_early_list)) {
1303 		struct device *dev = to_device(dpm_late_early_list.prev);
1304 
1305 		get_device(dev);
1306 		mutex_unlock(&dpm_list_mtx);
1307 
1308 		error = device_suspend_noirq(dev);
1309 
1310 		mutex_lock(&dpm_list_mtx);
1311 
1312 		if (error) {
1313 			pm_dev_err(dev, state, " noirq", error);
1314 			dpm_save_failed_dev(dev_name(dev));
1315 		} else if (!list_empty(&dev->power.entry)) {
1316 			list_move(&dev->power.entry, &dpm_noirq_list);
1317 		}
1318 
1319 		mutex_unlock(&dpm_list_mtx);
1320 
1321 		put_device(dev);
1322 
1323 		mutex_lock(&dpm_list_mtx);
1324 
1325 		if (error || async_error)
1326 			break;
1327 	}
1328 	mutex_unlock(&dpm_list_mtx);
1329 	async_synchronize_full();
1330 	if (!error)
1331 		error = async_error;
1332 
1333 	if (error) {
1334 		suspend_stats.failed_suspend_noirq++;
1335 		dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ);
1336 	}
1337 	dpm_show_time(starttime, state, error, "noirq");
1338 	trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, false);
1339 	return error;
1340 }
1341 
1342 /**
1343  * dpm_suspend_noirq - Execute "noirq suspend" callbacks for all devices.
1344  * @state: PM transition of the system being carried out.
1345  *
1346  * Prevent device drivers' interrupt handlers from being called and invoke
1347  * "noirq" suspend callbacks for all non-sysdev devices.
1348  */
dpm_suspend_noirq(pm_message_t state)1349 int dpm_suspend_noirq(pm_message_t state)
1350 {
1351 	int ret;
1352 
1353 	device_wakeup_arm_wake_irqs();
1354 	suspend_device_irqs();
1355 
1356 	ret = dpm_noirq_suspend_devices(state);
1357 	if (ret)
1358 		dpm_resume_noirq(resume_event(state));
1359 
1360 	return ret;
1361 }
1362 
dpm_propagate_wakeup_to_parent(struct device * dev)1363 static void dpm_propagate_wakeup_to_parent(struct device *dev)
1364 {
1365 	struct device *parent = dev->parent;
1366 
1367 	if (!parent)
1368 		return;
1369 
1370 	spin_lock_irq(&parent->power.lock);
1371 
1372 	if (device_wakeup_path(dev) && !parent->power.ignore_children)
1373 		parent->power.wakeup_path = true;
1374 
1375 	spin_unlock_irq(&parent->power.lock);
1376 }
1377 
1378 /**
1379  * __device_suspend_late - Execute a "late suspend" callback for given device.
1380  * @dev: Device to handle.
1381  * @state: PM transition of the system being carried out.
1382  * @async: If true, the device is being suspended asynchronously.
1383  *
1384  * Runtime PM is disabled for @dev while this function is being executed.
1385  */
__device_suspend_late(struct device * dev,pm_message_t state,bool async)1386 static int __device_suspend_late(struct device *dev, pm_message_t state, bool async)
1387 {
1388 	pm_callback_t callback = NULL;
1389 	const char *info = NULL;
1390 	int error = 0;
1391 
1392 	TRACE_DEVICE(dev);
1393 	TRACE_SUSPEND(0);
1394 
1395 	__pm_runtime_disable(dev, false);
1396 
1397 	dpm_wait_for_subordinate(dev, async);
1398 
1399 	if (async_error)
1400 		goto Complete;
1401 
1402 	if (pm_wakeup_pending()) {
1403 		async_error = -EBUSY;
1404 		goto Complete;
1405 	}
1406 
1407 	if (dev->power.syscore || dev->power.direct_complete)
1408 		goto Complete;
1409 
1410 	if (dev->pm_domain) {
1411 		info = "late power domain ";
1412 		callback = pm_late_early_op(&dev->pm_domain->ops, state);
1413 	} else if (dev->type && dev->type->pm) {
1414 		info = "late type ";
1415 		callback = pm_late_early_op(dev->type->pm, state);
1416 	} else if (dev->class && dev->class->pm) {
1417 		info = "late class ";
1418 		callback = pm_late_early_op(dev->class->pm, state);
1419 	} else if (dev->bus && dev->bus->pm) {
1420 		info = "late bus ";
1421 		callback = pm_late_early_op(dev->bus->pm, state);
1422 	}
1423 	if (callback)
1424 		goto Run;
1425 
1426 	if (dev_pm_skip_suspend(dev))
1427 		goto Skip;
1428 
1429 	if (dev->driver && dev->driver->pm) {
1430 		info = "late driver ";
1431 		callback = pm_late_early_op(dev->driver->pm, state);
1432 	}
1433 
1434 Run:
1435 	error = dpm_run_callback(callback, dev, state, info);
1436 	if (error) {
1437 		async_error = error;
1438 		goto Complete;
1439 	}
1440 	dpm_propagate_wakeup_to_parent(dev);
1441 
1442 Skip:
1443 	dev->power.is_late_suspended = true;
1444 
1445 Complete:
1446 	TRACE_SUSPEND(error);
1447 	complete_all(&dev->power.completion);
1448 	return error;
1449 }
1450 
async_suspend_late(void * data,async_cookie_t cookie)1451 static void async_suspend_late(void *data, async_cookie_t cookie)
1452 {
1453 	struct device *dev = (struct device *)data;
1454 	int error;
1455 
1456 	error = __device_suspend_late(dev, pm_transition, true);
1457 	if (error) {
1458 		dpm_save_failed_dev(dev_name(dev));
1459 		pm_dev_err(dev, pm_transition, " async", error);
1460 	}
1461 	put_device(dev);
1462 }
1463 
device_suspend_late(struct device * dev)1464 static int device_suspend_late(struct device *dev)
1465 {
1466 	if (dpm_async_fn(dev, async_suspend_late))
1467 		return 0;
1468 
1469 	return __device_suspend_late(dev, pm_transition, false);
1470 }
1471 
1472 /**
1473  * dpm_suspend_late - Execute "late suspend" callbacks for all devices.
1474  * @state: PM transition of the system being carried out.
1475  */
dpm_suspend_late(pm_message_t state)1476 int dpm_suspend_late(pm_message_t state)
1477 {
1478 	ktime_t starttime = ktime_get();
1479 	int error = 0;
1480 
1481 	trace_suspend_resume(TPS("dpm_suspend_late"), state.event, true);
1482 	wake_up_all_idle_cpus();
1483 	mutex_lock(&dpm_list_mtx);
1484 	pm_transition = state;
1485 	async_error = 0;
1486 
1487 	while (!list_empty(&dpm_suspended_list)) {
1488 		struct device *dev = to_device(dpm_suspended_list.prev);
1489 
1490 		get_device(dev);
1491 
1492 		mutex_unlock(&dpm_list_mtx);
1493 
1494 		error = device_suspend_late(dev);
1495 
1496 		mutex_lock(&dpm_list_mtx);
1497 
1498 		if (!list_empty(&dev->power.entry))
1499 			list_move(&dev->power.entry, &dpm_late_early_list);
1500 
1501 		if (error) {
1502 			pm_dev_err(dev, state, " late", error);
1503 			dpm_save_failed_dev(dev_name(dev));
1504 		}
1505 
1506 		mutex_unlock(&dpm_list_mtx);
1507 
1508 		put_device(dev);
1509 
1510 		mutex_lock(&dpm_list_mtx);
1511 
1512 		if (error || async_error)
1513 			break;
1514 	}
1515 	mutex_unlock(&dpm_list_mtx);
1516 	async_synchronize_full();
1517 	if (!error)
1518 		error = async_error;
1519 	if (error) {
1520 		suspend_stats.failed_suspend_late++;
1521 		dpm_save_failed_step(SUSPEND_SUSPEND_LATE);
1522 		dpm_resume_early(resume_event(state));
1523 	}
1524 	dpm_show_time(starttime, state, error, "late");
1525 	trace_suspend_resume(TPS("dpm_suspend_late"), state.event, false);
1526 	return error;
1527 }
1528 
1529 /**
1530  * dpm_suspend_end - Execute "late" and "noirq" device suspend callbacks.
1531  * @state: PM transition of the system being carried out.
1532  */
dpm_suspend_end(pm_message_t state)1533 int dpm_suspend_end(pm_message_t state)
1534 {
1535 	ktime_t starttime = ktime_get();
1536 	int error;
1537 
1538 	error = dpm_suspend_late(state);
1539 	if (error)
1540 		goto out;
1541 
1542 	error = dpm_suspend_noirq(state);
1543 	if (error)
1544 		dpm_resume_early(resume_event(state));
1545 
1546 out:
1547 	dpm_show_time(starttime, state, error, "end");
1548 	return error;
1549 }
1550 EXPORT_SYMBOL_GPL(dpm_suspend_end);
1551 
1552 /**
1553  * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
1554  * @dev: Device to suspend.
1555  * @state: PM transition of the system being carried out.
1556  * @cb: Suspend callback to execute.
1557  * @info: string description of caller.
1558  */
legacy_suspend(struct device * dev,pm_message_t state,int (* cb)(struct device * dev,pm_message_t state),const char * info)1559 static int legacy_suspend(struct device *dev, pm_message_t state,
1560 			  int (*cb)(struct device *dev, pm_message_t state),
1561 			  const char *info)
1562 {
1563 	int error;
1564 	ktime_t calltime;
1565 
1566 	calltime = initcall_debug_start(dev, cb);
1567 
1568 	trace_device_pm_callback_start(dev, info, state.event);
1569 	error = cb(dev, state);
1570 	trace_device_pm_callback_end(dev, error);
1571 	suspend_report_result(dev, cb, error);
1572 
1573 	initcall_debug_report(dev, calltime, cb, error);
1574 
1575 	return error;
1576 }
1577 
dpm_clear_superiors_direct_complete(struct device * dev)1578 static void dpm_clear_superiors_direct_complete(struct device *dev)
1579 {
1580 	struct device_link *link;
1581 	int idx;
1582 
1583 	if (dev->parent) {
1584 		spin_lock_irq(&dev->parent->power.lock);
1585 		dev->parent->power.direct_complete = false;
1586 		spin_unlock_irq(&dev->parent->power.lock);
1587 	}
1588 
1589 	idx = device_links_read_lock();
1590 
1591 	list_for_each_entry_rcu_locked(link, &dev->links.suppliers, c_node) {
1592 		spin_lock_irq(&link->supplier->power.lock);
1593 		link->supplier->power.direct_complete = false;
1594 		spin_unlock_irq(&link->supplier->power.lock);
1595 	}
1596 
1597 	device_links_read_unlock(idx);
1598 }
1599 
1600 /**
1601  * __device_suspend - Execute "suspend" callbacks for given device.
1602  * @dev: Device to handle.
1603  * @state: PM transition of the system being carried out.
1604  * @async: If true, the device is being suspended asynchronously.
1605  */
__device_suspend(struct device * dev,pm_message_t state,bool async)1606 static int __device_suspend(struct device *dev, pm_message_t state, bool async)
1607 {
1608 	pm_callback_t callback = NULL;
1609 	const char *info = NULL;
1610 	int error = 0;
1611 	DECLARE_DPM_WATCHDOG_ON_STACK(wd);
1612 
1613 	TRACE_DEVICE(dev);
1614 	TRACE_SUSPEND(0);
1615 
1616 	dpm_wait_for_subordinate(dev, async);
1617 
1618 	if (async_error) {
1619 		dev->power.direct_complete = false;
1620 		goto Complete;
1621 	}
1622 
1623 	/*
1624 	 * Wait for possible runtime PM transitions of the device in progress
1625 	 * to complete and if there's a runtime resume request pending for it,
1626 	 * resume it before proceeding with invoking the system-wide suspend
1627 	 * callbacks for it.
1628 	 *
1629 	 * If the system-wide suspend callbacks below change the configuration
1630 	 * of the device, they must disable runtime PM for it or otherwise
1631 	 * ensure that its runtime-resume callbacks will not be confused by that
1632 	 * change in case they are invoked going forward.
1633 	 */
1634 	pm_runtime_barrier(dev);
1635 
1636 	if (pm_wakeup_pending()) {
1637 		dev->power.direct_complete = false;
1638 		async_error = -EBUSY;
1639 		goto Complete;
1640 	}
1641 
1642 	if (dev->power.syscore)
1643 		goto Complete;
1644 
1645 	/* Avoid direct_complete to let wakeup_path propagate. */
1646 	if (device_may_wakeup(dev) || device_wakeup_path(dev))
1647 		dev->power.direct_complete = false;
1648 
1649 	if (dev->power.direct_complete) {
1650 		if (pm_runtime_status_suspended(dev)) {
1651 			pm_runtime_disable(dev);
1652 			if (pm_runtime_status_suspended(dev)) {
1653 				pm_dev_dbg(dev, state, "direct-complete ");
1654 				goto Complete;
1655 			}
1656 
1657 			pm_runtime_enable(dev);
1658 		}
1659 		dev->power.direct_complete = false;
1660 	}
1661 
1662 	dev->power.may_skip_resume = true;
1663 	dev->power.must_resume = !dev_pm_test_driver_flags(dev, DPM_FLAG_MAY_SKIP_RESUME);
1664 
1665 	dpm_watchdog_set(&wd, dev);
1666 	device_lock(dev);
1667 
1668 	if (dev->pm_domain) {
1669 		info = "power domain ";
1670 		callback = pm_op(&dev->pm_domain->ops, state);
1671 		goto Run;
1672 	}
1673 
1674 	if (dev->type && dev->type->pm) {
1675 		info = "type ";
1676 		callback = pm_op(dev->type->pm, state);
1677 		goto Run;
1678 	}
1679 
1680 	if (dev->class && dev->class->pm) {
1681 		info = "class ";
1682 		callback = pm_op(dev->class->pm, state);
1683 		goto Run;
1684 	}
1685 
1686 	if (dev->bus) {
1687 		if (dev->bus->pm) {
1688 			info = "bus ";
1689 			callback = pm_op(dev->bus->pm, state);
1690 		} else if (dev->bus->suspend) {
1691 			pm_dev_dbg(dev, state, "legacy bus ");
1692 			error = legacy_suspend(dev, state, dev->bus->suspend,
1693 						"legacy bus ");
1694 			goto End;
1695 		}
1696 	}
1697 
1698  Run:
1699 	if (!callback && dev->driver && dev->driver->pm) {
1700 		info = "driver ";
1701 		callback = pm_op(dev->driver->pm, state);
1702 	}
1703 
1704 	error = dpm_run_callback(callback, dev, state, info);
1705 
1706  End:
1707 	if (!error) {
1708 		dev->power.is_suspended = true;
1709 		if (device_may_wakeup(dev))
1710 			dev->power.wakeup_path = true;
1711 
1712 		dpm_propagate_wakeup_to_parent(dev);
1713 		dpm_clear_superiors_direct_complete(dev);
1714 	}
1715 
1716 	device_unlock(dev);
1717 	dpm_watchdog_clear(&wd);
1718 
1719  Complete:
1720 	if (error)
1721 		async_error = error;
1722 
1723 	complete_all(&dev->power.completion);
1724 	TRACE_SUSPEND(error);
1725 	return error;
1726 }
1727 
async_suspend(void * data,async_cookie_t cookie)1728 static void async_suspend(void *data, async_cookie_t cookie)
1729 {
1730 	struct device *dev = (struct device *)data;
1731 	int error;
1732 
1733 	error = __device_suspend(dev, pm_transition, true);
1734 	if (error) {
1735 		dpm_save_failed_dev(dev_name(dev));
1736 		pm_dev_err(dev, pm_transition, " async", error);
1737 	}
1738 
1739 	put_device(dev);
1740 }
1741 
device_suspend(struct device * dev)1742 static int device_suspend(struct device *dev)
1743 {
1744 	if (dpm_async_fn(dev, async_suspend))
1745 		return 0;
1746 
1747 	return __device_suspend(dev, pm_transition, false);
1748 }
1749 
1750 /**
1751  * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
1752  * @state: PM transition of the system being carried out.
1753  */
dpm_suspend(pm_message_t state)1754 int dpm_suspend(pm_message_t state)
1755 {
1756 	ktime_t starttime = ktime_get();
1757 	int error = 0;
1758 
1759 	trace_suspend_resume(TPS("dpm_suspend"), state.event, true);
1760 	might_sleep();
1761 
1762 	devfreq_suspend();
1763 	cpufreq_suspend();
1764 
1765 	mutex_lock(&dpm_list_mtx);
1766 	pm_transition = state;
1767 	async_error = 0;
1768 	while (!list_empty(&dpm_prepared_list)) {
1769 		struct device *dev = to_device(dpm_prepared_list.prev);
1770 
1771 		get_device(dev);
1772 
1773 		mutex_unlock(&dpm_list_mtx);
1774 
1775 		error = device_suspend(dev);
1776 
1777 		mutex_lock(&dpm_list_mtx);
1778 
1779 		if (error) {
1780 			pm_dev_err(dev, state, "", error);
1781 			dpm_save_failed_dev(dev_name(dev));
1782 		} else if (!list_empty(&dev->power.entry)) {
1783 			list_move(&dev->power.entry, &dpm_suspended_list);
1784 		}
1785 
1786 		mutex_unlock(&dpm_list_mtx);
1787 
1788 		put_device(dev);
1789 
1790 		mutex_lock(&dpm_list_mtx);
1791 
1792 		if (error || async_error)
1793 			break;
1794 	}
1795 	mutex_unlock(&dpm_list_mtx);
1796 	async_synchronize_full();
1797 	if (!error)
1798 		error = async_error;
1799 	if (error) {
1800 		suspend_stats.failed_suspend++;
1801 		dpm_save_failed_step(SUSPEND_SUSPEND);
1802 	}
1803 	dpm_show_time(starttime, state, error, NULL);
1804 	trace_suspend_resume(TPS("dpm_suspend"), state.event, false);
1805 	return error;
1806 }
1807 
1808 /**
1809  * device_prepare - Prepare a device for system power transition.
1810  * @dev: Device to handle.
1811  * @state: PM transition of the system being carried out.
1812  *
1813  * Execute the ->prepare() callback(s) for given device.  No new children of the
1814  * device may be registered after this function has returned.
1815  */
device_prepare(struct device * dev,pm_message_t state)1816 static int device_prepare(struct device *dev, pm_message_t state)
1817 {
1818 	int (*callback)(struct device *) = NULL;
1819 	int ret = 0;
1820 
1821 	/*
1822 	 * If a device's parent goes into runtime suspend at the wrong time,
1823 	 * it won't be possible to resume the device.  To prevent this we
1824 	 * block runtime suspend here, during the prepare phase, and allow
1825 	 * it again during the complete phase.
1826 	 */
1827 	pm_runtime_get_noresume(dev);
1828 
1829 	if (dev->power.syscore)
1830 		return 0;
1831 
1832 	device_lock(dev);
1833 
1834 	dev->power.wakeup_path = false;
1835 
1836 	if (dev->power.no_pm_callbacks)
1837 		goto unlock;
1838 
1839 	if (dev->pm_domain)
1840 		callback = dev->pm_domain->ops.prepare;
1841 	else if (dev->type && dev->type->pm)
1842 		callback = dev->type->pm->prepare;
1843 	else if (dev->class && dev->class->pm)
1844 		callback = dev->class->pm->prepare;
1845 	else if (dev->bus && dev->bus->pm)
1846 		callback = dev->bus->pm->prepare;
1847 
1848 	if (!callback && dev->driver && dev->driver->pm)
1849 		callback = dev->driver->pm->prepare;
1850 
1851 	if (callback)
1852 		ret = callback(dev);
1853 
1854 unlock:
1855 	device_unlock(dev);
1856 
1857 	if (ret < 0) {
1858 		suspend_report_result(dev, callback, ret);
1859 		pm_runtime_put(dev);
1860 		return ret;
1861 	}
1862 	/*
1863 	 * A positive return value from ->prepare() means "this device appears
1864 	 * to be runtime-suspended and its state is fine, so if it really is
1865 	 * runtime-suspended, you can leave it in that state provided that you
1866 	 * will do the same thing with all of its descendants".  This only
1867 	 * applies to suspend transitions, however.
1868 	 */
1869 	spin_lock_irq(&dev->power.lock);
1870 	dev->power.direct_complete = state.event == PM_EVENT_SUSPEND &&
1871 		(ret > 0 || dev->power.no_pm_callbacks) &&
1872 		!dev_pm_test_driver_flags(dev, DPM_FLAG_NO_DIRECT_COMPLETE);
1873 	spin_unlock_irq(&dev->power.lock);
1874 	return 0;
1875 }
1876 
1877 /**
1878  * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1879  * @state: PM transition of the system being carried out.
1880  *
1881  * Execute the ->prepare() callback(s) for all devices.
1882  */
dpm_prepare(pm_message_t state)1883 int dpm_prepare(pm_message_t state)
1884 {
1885 	int error = 0;
1886 
1887 	trace_suspend_resume(TPS("dpm_prepare"), state.event, true);
1888 	might_sleep();
1889 
1890 	/*
1891 	 * Give a chance for the known devices to complete their probes, before
1892 	 * disable probing of devices. This sync point is important at least
1893 	 * at boot time + hibernation restore.
1894 	 */
1895 	wait_for_device_probe();
1896 	/*
1897 	 * It is unsafe if probing of devices will happen during suspend or
1898 	 * hibernation and system behavior will be unpredictable in this case.
1899 	 * So, let's prohibit device's probing here and defer their probes
1900 	 * instead. The normal behavior will be restored in dpm_complete().
1901 	 */
1902 	device_block_probing();
1903 
1904 	mutex_lock(&dpm_list_mtx);
1905 	while (!list_empty(&dpm_list) && !error) {
1906 		struct device *dev = to_device(dpm_list.next);
1907 
1908 		get_device(dev);
1909 
1910 		mutex_unlock(&dpm_list_mtx);
1911 
1912 		trace_device_pm_callback_start(dev, "", state.event);
1913 		error = device_prepare(dev, state);
1914 		trace_device_pm_callback_end(dev, error);
1915 
1916 		mutex_lock(&dpm_list_mtx);
1917 
1918 		if (!error) {
1919 			dev->power.is_prepared = true;
1920 			if (!list_empty(&dev->power.entry))
1921 				list_move_tail(&dev->power.entry, &dpm_prepared_list);
1922 		} else if (error == -EAGAIN) {
1923 			error = 0;
1924 		} else {
1925 			dev_info(dev, "not prepared for power transition: code %d\n",
1926 				 error);
1927 		}
1928 
1929 		mutex_unlock(&dpm_list_mtx);
1930 
1931 		put_device(dev);
1932 
1933 		mutex_lock(&dpm_list_mtx);
1934 	}
1935 	mutex_unlock(&dpm_list_mtx);
1936 	trace_suspend_resume(TPS("dpm_prepare"), state.event, false);
1937 	return error;
1938 }
1939 
1940 /**
1941  * dpm_suspend_start - Prepare devices for PM transition and suspend them.
1942  * @state: PM transition of the system being carried out.
1943  *
1944  * Prepare all non-sysdev devices for system PM transition and execute "suspend"
1945  * callbacks for them.
1946  */
dpm_suspend_start(pm_message_t state)1947 int dpm_suspend_start(pm_message_t state)
1948 {
1949 	ktime_t starttime = ktime_get();
1950 	int error;
1951 
1952 	error = dpm_prepare(state);
1953 	if (error) {
1954 		suspend_stats.failed_prepare++;
1955 		dpm_save_failed_step(SUSPEND_PREPARE);
1956 	} else
1957 		error = dpm_suspend(state);
1958 	dpm_show_time(starttime, state, error, "start");
1959 	return error;
1960 }
1961 EXPORT_SYMBOL_GPL(dpm_suspend_start);
1962 
__suspend_report_result(const char * function,struct device * dev,void * fn,int ret)1963 void __suspend_report_result(const char *function, struct device *dev, void *fn, int ret)
1964 {
1965 	if (ret)
1966 		dev_err(dev, "%s(): %pS returns %d\n", function, fn, ret);
1967 }
1968 EXPORT_SYMBOL_GPL(__suspend_report_result);
1969 
1970 /**
1971  * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
1972  * @subordinate: Device that needs to wait for @dev.
1973  * @dev: Device to wait for.
1974  */
device_pm_wait_for_dev(struct device * subordinate,struct device * dev)1975 int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
1976 {
1977 	dpm_wait(dev, subordinate->power.async_suspend);
1978 	return async_error;
1979 }
1980 EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);
1981 
1982 /**
1983  * dpm_for_each_dev - device iterator.
1984  * @data: data for the callback.
1985  * @fn: function to be called for each device.
1986  *
1987  * Iterate over devices in dpm_list, and call @fn for each device,
1988  * passing it @data.
1989  */
dpm_for_each_dev(void * data,void (* fn)(struct device *,void *))1990 void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *))
1991 {
1992 	struct device *dev;
1993 
1994 	if (!fn)
1995 		return;
1996 
1997 	device_pm_lock();
1998 	list_for_each_entry(dev, &dpm_list, power.entry)
1999 		fn(dev, data);
2000 	device_pm_unlock();
2001 }
2002 EXPORT_SYMBOL_GPL(dpm_for_each_dev);
2003 
pm_ops_is_empty(const struct dev_pm_ops * ops)2004 static bool pm_ops_is_empty(const struct dev_pm_ops *ops)
2005 {
2006 	if (!ops)
2007 		return true;
2008 
2009 	return !ops->prepare &&
2010 	       !ops->suspend &&
2011 	       !ops->suspend_late &&
2012 	       !ops->suspend_noirq &&
2013 	       !ops->resume_noirq &&
2014 	       !ops->resume_early &&
2015 	       !ops->resume &&
2016 	       !ops->complete;
2017 }
2018 
device_pm_check_callbacks(struct device * dev)2019 void device_pm_check_callbacks(struct device *dev)
2020 {
2021 	unsigned long flags;
2022 
2023 	spin_lock_irqsave(&dev->power.lock, flags);
2024 	dev->power.no_pm_callbacks =
2025 		(!dev->bus || (pm_ops_is_empty(dev->bus->pm) &&
2026 		 !dev->bus->suspend && !dev->bus->resume)) &&
2027 		(!dev->class || pm_ops_is_empty(dev->class->pm)) &&
2028 		(!dev->type || pm_ops_is_empty(dev->type->pm)) &&
2029 		(!dev->pm_domain || pm_ops_is_empty(&dev->pm_domain->ops)) &&
2030 		(!dev->driver || (pm_ops_is_empty(dev->driver->pm) &&
2031 		 !dev->driver->suspend && !dev->driver->resume));
2032 	spin_unlock_irqrestore(&dev->power.lock, flags);
2033 }
2034 
dev_pm_skip_suspend(struct device * dev)2035 bool dev_pm_skip_suspend(struct device *dev)
2036 {
2037 	return dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) &&
2038 		pm_runtime_status_suspended(dev);
2039 }
2040