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1/*
2 * drivers/base/power/main.c - Where the driver meets power management.
3 *
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Open Source Development Lab
6 *
7 * This file is released under the GPLv2
8 *
9 *
10 * The driver model core calls device_pm_add() when a device is registered.
11 * This will initialize the embedded device_pm_info object in the device
12 * and add it to the list of power-controlled devices. sysfs entries for
13 * controlling device power management will also be added.
14 *
15 * A separate list is used for keeping track of power info, because the power
16 * domain dependencies may differ from the ancestral dependencies that the
17 * subsystem list maintains.
18 */
19
20#include <linux/device.h>
21#include <linux/kallsyms.h>
22#include <linux/mutex.h>
23#include <linux/pm.h>
24#include <linux/pm_runtime.h>
25#include <linux/resume-trace.h>
26#include <linux/interrupt.h>
27#include <linux/sched.h>
28#include <linux/async.h>
29#include <linux/suspend.h>
30
31#include "../base.h"
32#include "power.h"
33
34/*
35 * The entries in the dpm_list list are in a depth first order, simply
36 * because children are guaranteed to be discovered after parents, and
37 * are inserted at the back of the list on discovery.
38 *
39 * Since device_pm_add() may be called with a device lock held,
40 * we must never try to acquire a device lock while holding
41 * dpm_list_mutex.
42 */
43
44LIST_HEAD(dpm_list);
45LIST_HEAD(dpm_prepared_list);
46LIST_HEAD(dpm_suspended_list);
47LIST_HEAD(dpm_noirq_list);
48
49static DEFINE_MUTEX(dpm_list_mtx);
50static pm_message_t pm_transition;
51
52static int async_error;
53
54/**
55 * device_pm_init - Initialize the PM-related part of a device object.
56 * @dev: Device object being initialized.
57 */
58void device_pm_init(struct device *dev)
59{
60 dev->power.is_prepared = false;
61 dev->power.is_suspended = false;
62 init_completion(&dev->power.completion);
63 complete_all(&dev->power.completion);
64 dev->power.wakeup = NULL;
65 spin_lock_init(&dev->power.lock);
66 pm_runtime_init(dev);
67 INIT_LIST_HEAD(&dev->power.entry);
68}
69
70/**
71 * device_pm_lock - Lock the list of active devices used by the PM core.
72 */
73void device_pm_lock(void)
74{
75 mutex_lock(&dpm_list_mtx);
76}
77
78/**
79 * device_pm_unlock - Unlock the list of active devices used by the PM core.
80 */
81void device_pm_unlock(void)
82{
83 mutex_unlock(&dpm_list_mtx);
84}
85
86/**
87 * device_pm_add - Add a device to the PM core's list of active devices.
88 * @dev: Device to add to the list.
89 */
90void device_pm_add(struct device *dev)
91{
92 pr_debug("PM: Adding info for %s:%s\n",
93 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
94 mutex_lock(&dpm_list_mtx);
95 if (dev->parent && dev->parent->power.is_prepared)
96 dev_warn(dev, "parent %s should not be sleeping\n",
97 dev_name(dev->parent));
98 list_add_tail(&dev->power.entry, &dpm_list);
99 mutex_unlock(&dpm_list_mtx);
100}
101
102/**
103 * device_pm_remove - Remove a device from the PM core's list of active devices.
104 * @dev: Device to be removed from the list.
105 */
106void device_pm_remove(struct device *dev)
107{
108 pr_debug("PM: Removing info for %s:%s\n",
109 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
110 complete_all(&dev->power.completion);
111 mutex_lock(&dpm_list_mtx);
112 list_del_init(&dev->power.entry);
113 mutex_unlock(&dpm_list_mtx);
114 device_wakeup_disable(dev);
115 pm_runtime_remove(dev);
116}
117
118/**
119 * device_pm_move_before - Move device in the PM core's list of active devices.
120 * @deva: Device to move in dpm_list.
121 * @devb: Device @deva should come before.
122 */
123void device_pm_move_before(struct device *deva, struct device *devb)
124{
125 pr_debug("PM: Moving %s:%s before %s:%s\n",
126 deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
127 devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
128 /* Delete deva from dpm_list and reinsert before devb. */
129 list_move_tail(&deva->power.entry, &devb->power.entry);
130}
131
132/**
133 * device_pm_move_after - Move device in the PM core's list of active devices.
134 * @deva: Device to move in dpm_list.
135 * @devb: Device @deva should come after.
136 */
137void device_pm_move_after(struct device *deva, struct device *devb)
138{
139 pr_debug("PM: Moving %s:%s after %s:%s\n",
140 deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
141 devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
142 /* Delete deva from dpm_list and reinsert after devb. */
143 list_move(&deva->power.entry, &devb->power.entry);
144}
145
146/**
147 * device_pm_move_last - Move device to end of the PM core's list of devices.
148 * @dev: Device to move in dpm_list.
149 */
150void device_pm_move_last(struct device *dev)
151{
152 pr_debug("PM: Moving %s:%s to end of list\n",
153 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
154 list_move_tail(&dev->power.entry, &dpm_list);
155}
156
157static ktime_t initcall_debug_start(struct device *dev)
158{
159 ktime_t calltime = ktime_set(0, 0);
160
161 if (initcall_debug) {
162 pr_info("calling %s+ @ %i\n",
163 dev_name(dev), task_pid_nr(current));
164 calltime = ktime_get();
165 }
166
167 return calltime;
168}
169
170static void initcall_debug_report(struct device *dev, ktime_t calltime,
171 int error)
172{
173 ktime_t delta, rettime;
174
175 if (initcall_debug) {
176 rettime = ktime_get();
177 delta = ktime_sub(rettime, calltime);
178 pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev),
179 error, (unsigned long long)ktime_to_ns(delta) >> 10);
180 }
181}
182
183/**
184 * dpm_wait - Wait for a PM operation to complete.
185 * @dev: Device to wait for.
186 * @async: If unset, wait only if the device's power.async_suspend flag is set.
187 */
188static void dpm_wait(struct device *dev, bool async)
189{
190 if (!dev)
191 return;
192
193 if (async || (pm_async_enabled && dev->power.async_suspend))
194 wait_for_completion(&dev->power.completion);
195}
196
197static int dpm_wait_fn(struct device *dev, void *async_ptr)
198{
199 dpm_wait(dev, *((bool *)async_ptr));
200 return 0;
201}
202
203static void dpm_wait_for_children(struct device *dev, bool async)
204{
205 device_for_each_child(dev, &async, dpm_wait_fn);
206}
207
208/**
209 * pm_op - Execute the PM operation appropriate for given PM event.
210 * @dev: Device to handle.
211 * @ops: PM operations to choose from.
212 * @state: PM transition of the system being carried out.
213 */
214static int pm_op(struct device *dev,
215 const struct dev_pm_ops *ops,
216 pm_message_t state)
217{
218 int error = 0;
219 ktime_t calltime;
220
221 calltime = initcall_debug_start(dev);
222
223 switch (state.event) {
224#ifdef CONFIG_SUSPEND
225 case PM_EVENT_SUSPEND:
226 if (ops->suspend) {
227 error = ops->suspend(dev);
228 suspend_report_result(ops->suspend, error);
229 }
230 break;
231 case PM_EVENT_RESUME:
232 if (ops->resume) {
233 error = ops->resume(dev);
234 suspend_report_result(ops->resume, error);
235 }
236 break;
237#endif /* CONFIG_SUSPEND */
238#ifdef CONFIG_HIBERNATE_CALLBACKS
239 case PM_EVENT_FREEZE:
240 case PM_EVENT_QUIESCE:
241 if (ops->freeze) {
242 error = ops->freeze(dev);
243 suspend_report_result(ops->freeze, error);
244 }
245 break;
246 case PM_EVENT_HIBERNATE:
247 if (ops->poweroff) {
248 error = ops->poweroff(dev);
249 suspend_report_result(ops->poweroff, error);
250 }
251 break;
252 case PM_EVENT_THAW:
253 case PM_EVENT_RECOVER:
254 if (ops->thaw) {
255 error = ops->thaw(dev);
256 suspend_report_result(ops->thaw, error);
257 }
258 break;
259 case PM_EVENT_RESTORE:
260 if (ops->restore) {
261 error = ops->restore(dev);
262 suspend_report_result(ops->restore, error);
263 }
264 break;
265#endif /* CONFIG_HIBERNATE_CALLBACKS */
266 default:
267 error = -EINVAL;
268 }
269
270 initcall_debug_report(dev, calltime, error);
271
272 return error;
273}
274
275/**
276 * pm_noirq_op - Execute the PM operation appropriate for given PM event.
277 * @dev: Device to handle.
278 * @ops: PM operations to choose from.
279 * @state: PM transition of the system being carried out.
280 *
281 * The driver of @dev will not receive interrupts while this function is being
282 * executed.
283 */
284static int pm_noirq_op(struct device *dev,
285 const struct dev_pm_ops *ops,
286 pm_message_t state)
287{
288 int error = 0;
289 ktime_t calltime = ktime_set(0, 0), delta, rettime;
290
291 if (initcall_debug) {
292 pr_info("calling %s+ @ %i, parent: %s\n",
293 dev_name(dev), task_pid_nr(current),
294 dev->parent ? dev_name(dev->parent) : "none");
295 calltime = ktime_get();
296 }
297
298 switch (state.event) {
299#ifdef CONFIG_SUSPEND
300 case PM_EVENT_SUSPEND:
301 if (ops->suspend_noirq) {
302 error = ops->suspend_noirq(dev);
303 suspend_report_result(ops->suspend_noirq, error);
304 }
305 break;
306 case PM_EVENT_RESUME:
307 if (ops->resume_noirq) {
308 error = ops->resume_noirq(dev);
309 suspend_report_result(ops->resume_noirq, error);
310 }
311 break;
312#endif /* CONFIG_SUSPEND */
313#ifdef CONFIG_HIBERNATE_CALLBACKS
314 case PM_EVENT_FREEZE:
315 case PM_EVENT_QUIESCE:
316 if (ops->freeze_noirq) {
317 error = ops->freeze_noirq(dev);
318 suspend_report_result(ops->freeze_noirq, error);
319 }
320 break;
321 case PM_EVENT_HIBERNATE:
322 if (ops->poweroff_noirq) {
323 error = ops->poweroff_noirq(dev);
324 suspend_report_result(ops->poweroff_noirq, error);
325 }
326 break;
327 case PM_EVENT_THAW:
328 case PM_EVENT_RECOVER:
329 if (ops->thaw_noirq) {
330 error = ops->thaw_noirq(dev);
331 suspend_report_result(ops->thaw_noirq, error);
332 }
333 break;
334 case PM_EVENT_RESTORE:
335 if (ops->restore_noirq) {
336 error = ops->restore_noirq(dev);
337 suspend_report_result(ops->restore_noirq, error);
338 }
339 break;
340#endif /* CONFIG_HIBERNATE_CALLBACKS */
341 default:
342 error = -EINVAL;
343 }
344
345 if (initcall_debug) {
346 rettime = ktime_get();
347 delta = ktime_sub(rettime, calltime);
348 printk("initcall %s_i+ returned %d after %Ld usecs\n",
349 dev_name(dev), error,
350 (unsigned long long)ktime_to_ns(delta) >> 10);
351 }
352
353 return error;
354}
355
356static char *pm_verb(int event)
357{
358 switch (event) {
359 case PM_EVENT_SUSPEND:
360 return "suspend";
361 case PM_EVENT_RESUME:
362 return "resume";
363 case PM_EVENT_FREEZE:
364 return "freeze";
365 case PM_EVENT_QUIESCE:
366 return "quiesce";
367 case PM_EVENT_HIBERNATE:
368 return "hibernate";
369 case PM_EVENT_THAW:
370 return "thaw";
371 case PM_EVENT_RESTORE:
372 return "restore";
373 case PM_EVENT_RECOVER:
374 return "recover";
375 default:
376 return "(unknown PM event)";
377 }
378}
379
380static void pm_dev_dbg(struct device *dev, pm_message_t state, char *info)
381{
382 dev_dbg(dev, "%s%s%s\n", info, pm_verb(state.event),
383 ((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
384 ", may wakeup" : "");
385}
386
387static void pm_dev_err(struct device *dev, pm_message_t state, char *info,
388 int error)
389{
390 printk(KERN_ERR "PM: Device %s failed to %s%s: error %d\n",
391 dev_name(dev), pm_verb(state.event), info, error);
392}
393
394static void dpm_show_time(ktime_t starttime, pm_message_t state, char *info)
395{
396 ktime_t calltime;
397 u64 usecs64;
398 int usecs;
399
400 calltime = ktime_get();
401 usecs64 = ktime_to_ns(ktime_sub(calltime, starttime));
402 do_div(usecs64, NSEC_PER_USEC);
403 usecs = usecs64;
404 if (usecs == 0)
405 usecs = 1;
406 pr_info("PM: %s%s%s of devices complete after %ld.%03ld msecs\n",
407 info ?: "", info ? " " : "", pm_verb(state.event),
408 usecs / USEC_PER_MSEC, usecs % USEC_PER_MSEC);
409}
410
411/*------------------------- Resume routines -------------------------*/
412
413/**
414 * device_resume_noirq - Execute an "early resume" callback for given device.
415 * @dev: Device to handle.
416 * @state: PM transition of the system being carried out.
417 *
418 * The driver of @dev will not receive interrupts while this function is being
419 * executed.
420 */
421static int device_resume_noirq(struct device *dev, pm_message_t state)
422{
423 int error = 0;
424
425 TRACE_DEVICE(dev);
426 TRACE_RESUME(0);
427
428 if (dev->pm_domain) {
429 pm_dev_dbg(dev, state, "EARLY power domain ");
430 error = pm_noirq_op(dev, &dev->pm_domain->ops, state);
431 } else if (dev->type && dev->type->pm) {
432 pm_dev_dbg(dev, state, "EARLY type ");
433 error = pm_noirq_op(dev, dev->type->pm, state);
434 } else if (dev->class && dev->class->pm) {
435 pm_dev_dbg(dev, state, "EARLY class ");
436 error = pm_noirq_op(dev, dev->class->pm, state);
437 } else if (dev->bus && dev->bus->pm) {
438 pm_dev_dbg(dev, state, "EARLY ");
439 error = pm_noirq_op(dev, dev->bus->pm, state);
440 }
441
442 TRACE_RESUME(error);
443 return error;
444}
445
446/**
447 * dpm_resume_noirq - Execute "early resume" callbacks for non-sysdev devices.
448 * @state: PM transition of the system being carried out.
449 *
450 * Call the "noirq" resume handlers for all devices marked as DPM_OFF_IRQ and
451 * enable device drivers to receive interrupts.
452 */
453void dpm_resume_noirq(pm_message_t state)
454{
455 ktime_t starttime = ktime_get();
456
457 mutex_lock(&dpm_list_mtx);
458 while (!list_empty(&dpm_noirq_list)) {
459 struct device *dev = to_device(dpm_noirq_list.next);
460 int error;
461
462 get_device(dev);
463 list_move_tail(&dev->power.entry, &dpm_suspended_list);
464 mutex_unlock(&dpm_list_mtx);
465
466 error = device_resume_noirq(dev, state);
467 if (error)
468 pm_dev_err(dev, state, " early", error);
469
470 mutex_lock(&dpm_list_mtx);
471 put_device(dev);
472 }
473 mutex_unlock(&dpm_list_mtx);
474 dpm_show_time(starttime, state, "early");
475 resume_device_irqs();
476}
477EXPORT_SYMBOL_GPL(dpm_resume_noirq);
478
479/**
480 * legacy_resume - Execute a legacy (bus or class) resume callback for device.
481 * @dev: Device to resume.
482 * @cb: Resume callback to execute.
483 */
484static int legacy_resume(struct device *dev, int (*cb)(struct device *dev))
485{
486 int error;
487 ktime_t calltime;
488
489 calltime = initcall_debug_start(dev);
490
491 error = cb(dev);
492 suspend_report_result(cb, error);
493
494 initcall_debug_report(dev, calltime, error);
495
496 return error;
497}
498
499/**
500 * device_resume - Execute "resume" callbacks for given device.
501 * @dev: Device to handle.
502 * @state: PM transition of the system being carried out.
503 * @async: If true, the device is being resumed asynchronously.
504 */
505static int device_resume(struct device *dev, pm_message_t state, bool async)
506{
507 int error = 0;
508 bool put = false;
509
510 TRACE_DEVICE(dev);
511 TRACE_RESUME(0);
512
513 dpm_wait(dev->parent, async);
514 device_lock(dev);
515
516 /*
517 * This is a fib. But we'll allow new children to be added below
518 * a resumed device, even if the device hasn't been completed yet.
519 */
520 dev->power.is_prepared = false;
521
522 if (!dev->power.is_suspended)
523 goto Unlock;
524
525 pm_runtime_enable(dev);
526 put = true;
527
528 if (dev->pm_domain) {
529 pm_dev_dbg(dev, state, "power domain ");
530 error = pm_op(dev, &dev->pm_domain->ops, state);
531 goto End;
532 }
533
534 if (dev->type && dev->type->pm) {
535 pm_dev_dbg(dev, state, "type ");
536 error = pm_op(dev, dev->type->pm, state);
537 goto End;
538 }
539
540 if (dev->class) {
541 if (dev->class->pm) {
542 pm_dev_dbg(dev, state, "class ");
543 error = pm_op(dev, dev->class->pm, state);
544 goto End;
545 } else if (dev->class->resume) {
546 pm_dev_dbg(dev, state, "legacy class ");
547 error = legacy_resume(dev, dev->class->resume);
548 goto End;
549 }
550 }
551
552 if (dev->bus) {
553 if (dev->bus->pm) {
554 pm_dev_dbg(dev, state, "");
555 error = pm_op(dev, dev->bus->pm, state);
556 } else if (dev->bus->resume) {
557 pm_dev_dbg(dev, state, "legacy ");
558 error = legacy_resume(dev, dev->bus->resume);
559 }
560 }
561
562 End:
563 dev->power.is_suspended = false;
564
565 Unlock:
566 device_unlock(dev);
567 complete_all(&dev->power.completion);
568
569 TRACE_RESUME(error);
570
571 if (put)
572 pm_runtime_put_sync(dev);
573
574 return error;
575}
576
577static void async_resume(void *data, async_cookie_t cookie)
578{
579 struct device *dev = (struct device *)data;
580 int error;
581
582 error = device_resume(dev, pm_transition, true);
583 if (error)
584 pm_dev_err(dev, pm_transition, " async", error);
585 put_device(dev);
586}
587
588static bool is_async(struct device *dev)
589{
590 return dev->power.async_suspend && pm_async_enabled
591 && !pm_trace_is_enabled();
592}
593
594/**
595 * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
596 * @state: PM transition of the system being carried out.
597 *
598 * Execute the appropriate "resume" callback for all devices whose status
599 * indicates that they are suspended.
600 */
601void dpm_resume(pm_message_t state)
602{
603 struct device *dev;
604 ktime_t starttime = ktime_get();
605
606 might_sleep();
607
608 mutex_lock(&dpm_list_mtx);
609 pm_transition = state;
610 async_error = 0;
611
612 list_for_each_entry(dev, &dpm_suspended_list, power.entry) {
613 INIT_COMPLETION(dev->power.completion);
614 if (is_async(dev)) {
615 get_device(dev);
616 async_schedule(async_resume, dev);
617 }
618 }
619
620 while (!list_empty(&dpm_suspended_list)) {
621 dev = to_device(dpm_suspended_list.next);
622 get_device(dev);
623 if (!is_async(dev)) {
624 int error;
625
626 mutex_unlock(&dpm_list_mtx);
627
628 error = device_resume(dev, state, false);
629 if (error)
630 pm_dev_err(dev, state, "", error);
631
632 mutex_lock(&dpm_list_mtx);
633 }
634 if (!list_empty(&dev->power.entry))
635 list_move_tail(&dev->power.entry, &dpm_prepared_list);
636 put_device(dev);
637 }
638 mutex_unlock(&dpm_list_mtx);
639 async_synchronize_full();
640 dpm_show_time(starttime, state, NULL);
641}
642
643/**
644 * device_complete - Complete a PM transition for given device.
645 * @dev: Device to handle.
646 * @state: PM transition of the system being carried out.
647 */
648static void device_complete(struct device *dev, pm_message_t state)
649{
650 device_lock(dev);
651
652 if (dev->pm_domain) {
653 pm_dev_dbg(dev, state, "completing power domain ");
654 if (dev->pm_domain->ops.complete)
655 dev->pm_domain->ops.complete(dev);
656 } else if (dev->type && dev->type->pm) {
657 pm_dev_dbg(dev, state, "completing type ");
658 if (dev->type->pm->complete)
659 dev->type->pm->complete(dev);
660 } else if (dev->class && dev->class->pm) {
661 pm_dev_dbg(dev, state, "completing class ");
662 if (dev->class->pm->complete)
663 dev->class->pm->complete(dev);
664 } else if (dev->bus && dev->bus->pm) {
665 pm_dev_dbg(dev, state, "completing ");
666 if (dev->bus->pm->complete)
667 dev->bus->pm->complete(dev);
668 }
669
670 device_unlock(dev);
671}
672
673/**
674 * dpm_complete - Complete a PM transition for all non-sysdev devices.
675 * @state: PM transition of the system being carried out.
676 *
677 * Execute the ->complete() callbacks for all devices whose PM status is not
678 * DPM_ON (this allows new devices to be registered).
679 */
680void dpm_complete(pm_message_t state)
681{
682 struct list_head list;
683
684 might_sleep();
685
686 INIT_LIST_HEAD(&list);
687 mutex_lock(&dpm_list_mtx);
688 while (!list_empty(&dpm_prepared_list)) {
689 struct device *dev = to_device(dpm_prepared_list.prev);
690
691 get_device(dev);
692 dev->power.is_prepared = false;
693 list_move(&dev->power.entry, &list);
694 mutex_unlock(&dpm_list_mtx);
695
696 device_complete(dev, state);
697
698 mutex_lock(&dpm_list_mtx);
699 put_device(dev);
700 }
701 list_splice(&list, &dpm_list);
702 mutex_unlock(&dpm_list_mtx);
703}
704
705/**
706 * dpm_resume_end - Execute "resume" callbacks and complete system transition.
707 * @state: PM transition of the system being carried out.
708 *
709 * Execute "resume" callbacks for all devices and complete the PM transition of
710 * the system.
711 */
712void dpm_resume_end(pm_message_t state)
713{
714 dpm_resume(state);
715 dpm_complete(state);
716}
717EXPORT_SYMBOL_GPL(dpm_resume_end);
718
719
720/*------------------------- Suspend routines -------------------------*/
721
722/**
723 * resume_event - Return a "resume" message for given "suspend" sleep state.
724 * @sleep_state: PM message representing a sleep state.
725 *
726 * Return a PM message representing the resume event corresponding to given
727 * sleep state.
728 */
729static pm_message_t resume_event(pm_message_t sleep_state)
730{
731 switch (sleep_state.event) {
732 case PM_EVENT_SUSPEND:
733 return PMSG_RESUME;
734 case PM_EVENT_FREEZE:
735 case PM_EVENT_QUIESCE:
736 return PMSG_RECOVER;
737 case PM_EVENT_HIBERNATE:
738 return PMSG_RESTORE;
739 }
740 return PMSG_ON;
741}
742
743/**
744 * device_suspend_noirq - Execute a "late suspend" callback for given device.
745 * @dev: Device to handle.
746 * @state: PM transition of the system being carried out.
747 *
748 * The driver of @dev will not receive interrupts while this function is being
749 * executed.
750 */
751static int device_suspend_noirq(struct device *dev, pm_message_t state)
752{
753 int error;
754
755 if (dev->pm_domain) {
756 pm_dev_dbg(dev, state, "LATE power domain ");
757 error = pm_noirq_op(dev, &dev->pm_domain->ops, state);
758 if (error)
759 return error;
760 } else if (dev->type && dev->type->pm) {
761 pm_dev_dbg(dev, state, "LATE type ");
762 error = pm_noirq_op(dev, dev->type->pm, state);
763 if (error)
764 return error;
765 } else if (dev->class && dev->class->pm) {
766 pm_dev_dbg(dev, state, "LATE class ");
767 error = pm_noirq_op(dev, dev->class->pm, state);
768 if (error)
769 return error;
770 } else if (dev->bus && dev->bus->pm) {
771 pm_dev_dbg(dev, state, "LATE ");
772 error = pm_noirq_op(dev, dev->bus->pm, state);
773 if (error)
774 return error;
775 }
776
777 return 0;
778}
779
780/**
781 * dpm_suspend_noirq - Execute "late suspend" callbacks for non-sysdev devices.
782 * @state: PM transition of the system being carried out.
783 *
784 * Prevent device drivers from receiving interrupts and call the "noirq" suspend
785 * handlers for all non-sysdev devices.
786 */
787int dpm_suspend_noirq(pm_message_t state)
788{
789 ktime_t starttime = ktime_get();
790 int error = 0;
791
792 suspend_device_irqs();
793 mutex_lock(&dpm_list_mtx);
794 while (!list_empty(&dpm_suspended_list)) {
795 struct device *dev = to_device(dpm_suspended_list.prev);
796
797 get_device(dev);
798 mutex_unlock(&dpm_list_mtx);
799
800 error = device_suspend_noirq(dev, state);
801
802 mutex_lock(&dpm_list_mtx);
803 if (error) {
804 pm_dev_err(dev, state, " late", error);
805 put_device(dev);
806 break;
807 }
808 if (!list_empty(&dev->power.entry))
809 list_move(&dev->power.entry, &dpm_noirq_list);
810 put_device(dev);
811 }
812 mutex_unlock(&dpm_list_mtx);
813 if (error)
814 dpm_resume_noirq(resume_event(state));
815 else
816 dpm_show_time(starttime, state, "late");
817 return error;
818}
819EXPORT_SYMBOL_GPL(dpm_suspend_noirq);
820
821/**
822 * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
823 * @dev: Device to suspend.
824 * @state: PM transition of the system being carried out.
825 * @cb: Suspend callback to execute.
826 */
827static int legacy_suspend(struct device *dev, pm_message_t state,
828 int (*cb)(struct device *dev, pm_message_t state))
829{
830 int error;
831 ktime_t calltime;
832
833 calltime = initcall_debug_start(dev);
834
835 error = cb(dev, state);
836 suspend_report_result(cb, error);
837
838 initcall_debug_report(dev, calltime, error);
839
840 return error;
841}
842
843/**
844 * device_suspend - Execute "suspend" callbacks for given device.
845 * @dev: Device to handle.
846 * @state: PM transition of the system being carried out.
847 * @async: If true, the device is being suspended asynchronously.
848 */
849static int __device_suspend(struct device *dev, pm_message_t state, bool async)
850{
851 int error = 0;
852
853 dpm_wait_for_children(dev, async);
854
855 if (async_error)
856 return 0;
857
858 pm_runtime_get_noresume(dev);
859 if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
860 pm_wakeup_event(dev, 0);
861
862 if (pm_wakeup_pending()) {
863 pm_runtime_put_sync(dev);
864 async_error = -EBUSY;
865 return 0;
866 }
867
868 device_lock(dev);
869
870 if (dev->pm_domain) {
871 pm_dev_dbg(dev, state, "power domain ");
872 error = pm_op(dev, &dev->pm_domain->ops, state);
873 goto End;
874 }
875
876 if (dev->type && dev->type->pm) {
877 pm_dev_dbg(dev, state, "type ");
878 error = pm_op(dev, dev->type->pm, state);
879 goto End;
880 }
881
882 if (dev->class) {
883 if (dev->class->pm) {
884 pm_dev_dbg(dev, state, "class ");
885 error = pm_op(dev, dev->class->pm, state);
886 goto End;
887 } else if (dev->class->suspend) {
888 pm_dev_dbg(dev, state, "legacy class ");
889 error = legacy_suspend(dev, state, dev->class->suspend);
890 goto End;
891 }
892 }
893
894 if (dev->bus) {
895 if (dev->bus->pm) {
896 pm_dev_dbg(dev, state, "");
897 error = pm_op(dev, dev->bus->pm, state);
898 } else if (dev->bus->suspend) {
899 pm_dev_dbg(dev, state, "legacy ");
900 error = legacy_suspend(dev, state, dev->bus->suspend);
901 }
902 }
903
904 End:
905 dev->power.is_suspended = !error;
906
907 device_unlock(dev);
908 complete_all(&dev->power.completion);
909
910 if (error) {
911 pm_runtime_put_sync(dev);
912 async_error = error;
913 } else if (dev->power.is_suspended) {
914 __pm_runtime_disable(dev, false);
915 }
916
917 return error;
918}
919
920static void async_suspend(void *data, async_cookie_t cookie)
921{
922 struct device *dev = (struct device *)data;
923 int error;
924
925 error = __device_suspend(dev, pm_transition, true);
926 if (error)
927 pm_dev_err(dev, pm_transition, " async", error);
928
929 put_device(dev);
930}
931
932static int device_suspend(struct device *dev)
933{
934 INIT_COMPLETION(dev->power.completion);
935
936 if (pm_async_enabled && dev->power.async_suspend) {
937 get_device(dev);
938 async_schedule(async_suspend, dev);
939 return 0;
940 }
941
942 return __device_suspend(dev, pm_transition, false);
943}
944
945/**
946 * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
947 * @state: PM transition of the system being carried out.
948 */
949int dpm_suspend(pm_message_t state)
950{
951 ktime_t starttime = ktime_get();
952 int error = 0;
953
954 might_sleep();
955
956 mutex_lock(&dpm_list_mtx);
957 pm_transition = state;
958 async_error = 0;
959 while (!list_empty(&dpm_prepared_list)) {
960 struct device *dev = to_device(dpm_prepared_list.prev);
961
962 get_device(dev);
963 mutex_unlock(&dpm_list_mtx);
964
965 error = device_suspend(dev);
966
967 mutex_lock(&dpm_list_mtx);
968 if (error) {
969 pm_dev_err(dev, state, "", error);
970 put_device(dev);
971 break;
972 }
973 if (!list_empty(&dev->power.entry))
974 list_move(&dev->power.entry, &dpm_suspended_list);
975 put_device(dev);
976 if (async_error)
977 break;
978 }
979 mutex_unlock(&dpm_list_mtx);
980 async_synchronize_full();
981 if (!error)
982 error = async_error;
983 if (!error)
984 dpm_show_time(starttime, state, NULL);
985 return error;
986}
987
988/**
989 * device_prepare - Prepare a device for system power transition.
990 * @dev: Device to handle.
991 * @state: PM transition of the system being carried out.
992 *
993 * Execute the ->prepare() callback(s) for given device. No new children of the
994 * device may be registered after this function has returned.
995 */
996static int device_prepare(struct device *dev, pm_message_t state)
997{
998 int error = 0;
999
1000 device_lock(dev);
1001
1002 if (dev->pm_domain) {
1003 pm_dev_dbg(dev, state, "preparing power domain ");
1004 if (dev->pm_domain->ops.prepare)
1005 error = dev->pm_domain->ops.prepare(dev);
1006 suspend_report_result(dev->pm_domain->ops.prepare, error);
1007 if (error)
1008 goto End;
1009 } else if (dev->type && dev->type->pm) {
1010 pm_dev_dbg(dev, state, "preparing type ");
1011 if (dev->type->pm->prepare)
1012 error = dev->type->pm->prepare(dev);
1013 suspend_report_result(dev->type->pm->prepare, error);
1014 if (error)
1015 goto End;
1016 } else if (dev->class && dev->class->pm) {
1017 pm_dev_dbg(dev, state, "preparing class ");
1018 if (dev->class->pm->prepare)
1019 error = dev->class->pm->prepare(dev);
1020 suspend_report_result(dev->class->pm->prepare, error);
1021 if (error)
1022 goto End;
1023 } else if (dev->bus && dev->bus->pm) {
1024 pm_dev_dbg(dev, state, "preparing ");
1025 if (dev->bus->pm->prepare)
1026 error = dev->bus->pm->prepare(dev);
1027 suspend_report_result(dev->bus->pm->prepare, error);
1028 }
1029
1030 End:
1031 device_unlock(dev);
1032
1033 return error;
1034}
1035
1036/**
1037 * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1038 * @state: PM transition of the system being carried out.
1039 *
1040 * Execute the ->prepare() callback(s) for all devices.
1041 */
1042int dpm_prepare(pm_message_t state)
1043{
1044 int error = 0;
1045
1046 might_sleep();
1047
1048 mutex_lock(&dpm_list_mtx);
1049 while (!list_empty(&dpm_list)) {
1050 struct device *dev = to_device(dpm_list.next);
1051
1052 get_device(dev);
1053 mutex_unlock(&dpm_list_mtx);
1054
1055 error = device_prepare(dev, state);
1056
1057 mutex_lock(&dpm_list_mtx);
1058 if (error) {
1059 if (error == -EAGAIN) {
1060 put_device(dev);
1061 error = 0;
1062 continue;
1063 }
1064 printk(KERN_INFO "PM: Device %s not prepared "
1065 "for power transition: code %d\n",
1066 dev_name(dev), error);
1067 put_device(dev);
1068 break;
1069 }
1070 dev->power.is_prepared = true;
1071 if (!list_empty(&dev->power.entry))
1072 list_move_tail(&dev->power.entry, &dpm_prepared_list);
1073 put_device(dev);
1074 }
1075 mutex_unlock(&dpm_list_mtx);
1076 return error;
1077}
1078
1079/**
1080 * dpm_suspend_start - Prepare devices for PM transition and suspend them.
1081 * @state: PM transition of the system being carried out.
1082 *
1083 * Prepare all non-sysdev devices for system PM transition and execute "suspend"
1084 * callbacks for them.
1085 */
1086int dpm_suspend_start(pm_message_t state)
1087{
1088 int error;
1089
1090 error = dpm_prepare(state);
1091 if (!error)
1092 error = dpm_suspend(state);
1093 return error;
1094}
1095EXPORT_SYMBOL_GPL(dpm_suspend_start);
1096
1097void __suspend_report_result(const char *function, void *fn, int ret)
1098{
1099 if (ret)
1100 printk(KERN_ERR "%s(): %pF returns %d\n", function, fn, ret);
1101}
1102EXPORT_SYMBOL_GPL(__suspend_report_result);
1103
1104/**
1105 * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
1106 * @dev: Device to wait for.
1107 * @subordinate: Device that needs to wait for @dev.
1108 */
1109int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
1110{
1111 dpm_wait(dev, subordinate->power.async_suspend);
1112 return async_error;
1113}
1114EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);
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
41typedef 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
57LIST_HEAD(dpm_list);
58static LIST_HEAD(dpm_prepared_list);
59static LIST_HEAD(dpm_suspended_list);
60static LIST_HEAD(dpm_late_early_list);
61static LIST_HEAD(dpm_noirq_list);
62
63static DEFINE_MUTEX(dpm_list_mtx);
64static pm_message_t pm_transition;
65
66static int async_error;
67
68static const char *pm_verb(int event)
69{
70 switch (event) {
71 case PM_EVENT_SUSPEND:
72 return "suspend";
73 case PM_EVENT_RESUME:
74 return "resume";
75 case PM_EVENT_FREEZE:
76 return "freeze";
77 case PM_EVENT_QUIESCE:
78 return "quiesce";
79 case PM_EVENT_HIBERNATE:
80 return "hibernate";
81 case PM_EVENT_THAW:
82 return "thaw";
83 case PM_EVENT_RESTORE:
84 return "restore";
85 case PM_EVENT_RECOVER:
86 return "recover";
87 default:
88 return "(unknown PM event)";
89 }
90}
91
92/**
93 * device_pm_sleep_init - Initialize system suspend-related device fields.
94 * @dev: Device object being initialized.
95 */
96void device_pm_sleep_init(struct device *dev)
97{
98 dev->power.is_prepared = false;
99 dev->power.is_suspended = false;
100 dev->power.is_noirq_suspended = false;
101 dev->power.is_late_suspended = false;
102 init_completion(&dev->power.completion);
103 complete_all(&dev->power.completion);
104 dev->power.wakeup = NULL;
105 INIT_LIST_HEAD(&dev->power.entry);
106}
107
108/**
109 * device_pm_lock - Lock the list of active devices used by the PM core.
110 */
111void device_pm_lock(void)
112{
113 mutex_lock(&dpm_list_mtx);
114}
115
116/**
117 * device_pm_unlock - Unlock the list of active devices used by the PM core.
118 */
119void device_pm_unlock(void)
120{
121 mutex_unlock(&dpm_list_mtx);
122}
123
124/**
125 * device_pm_add - Add a device to the PM core's list of active devices.
126 * @dev: Device to add to the list.
127 */
128void device_pm_add(struct device *dev)
129{
130 /* Skip PM setup/initialization. */
131 if (device_pm_not_required(dev))
132 return;
133
134 pr_debug("Adding info for %s:%s\n",
135 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
136 device_pm_check_callbacks(dev);
137 mutex_lock(&dpm_list_mtx);
138 if (dev->parent && dev->parent->power.is_prepared)
139 dev_warn(dev, "parent %s should not be sleeping\n",
140 dev_name(dev->parent));
141 list_add_tail(&dev->power.entry, &dpm_list);
142 dev->power.in_dpm_list = true;
143 mutex_unlock(&dpm_list_mtx);
144}
145
146/**
147 * device_pm_remove - Remove a device from the PM core's list of active devices.
148 * @dev: Device to be removed from the list.
149 */
150void device_pm_remove(struct device *dev)
151{
152 if (device_pm_not_required(dev))
153 return;
154
155 pr_debug("Removing info for %s:%s\n",
156 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
157 complete_all(&dev->power.completion);
158 mutex_lock(&dpm_list_mtx);
159 list_del_init(&dev->power.entry);
160 dev->power.in_dpm_list = false;
161 mutex_unlock(&dpm_list_mtx);
162 device_wakeup_disable(dev);
163 pm_runtime_remove(dev);
164 device_pm_check_callbacks(dev);
165}
166
167/**
168 * device_pm_move_before - Move device in the PM core's list of active devices.
169 * @deva: Device to move in dpm_list.
170 * @devb: Device @deva should come before.
171 */
172void device_pm_move_before(struct device *deva, struct device *devb)
173{
174 pr_debug("Moving %s:%s before %s:%s\n",
175 deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
176 devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
177 /* Delete deva from dpm_list and reinsert before devb. */
178 list_move_tail(&deva->power.entry, &devb->power.entry);
179}
180
181/**
182 * device_pm_move_after - Move device in the PM core's list of active devices.
183 * @deva: Device to move in dpm_list.
184 * @devb: Device @deva should come after.
185 */
186void device_pm_move_after(struct device *deva, struct device *devb)
187{
188 pr_debug("Moving %s:%s after %s:%s\n",
189 deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
190 devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
191 /* Delete deva from dpm_list and reinsert after devb. */
192 list_move(&deva->power.entry, &devb->power.entry);
193}
194
195/**
196 * device_pm_move_last - Move device to end of the PM core's list of devices.
197 * @dev: Device to move in dpm_list.
198 */
199void device_pm_move_last(struct device *dev)
200{
201 pr_debug("Moving %s:%s to end of list\n",
202 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
203 list_move_tail(&dev->power.entry, &dpm_list);
204}
205
206static ktime_t initcall_debug_start(struct device *dev, void *cb)
207{
208 if (!pm_print_times_enabled)
209 return 0;
210
211 dev_info(dev, "calling %pS @ %i, parent: %s\n", cb,
212 task_pid_nr(current),
213 dev->parent ? dev_name(dev->parent) : "none");
214 return ktime_get();
215}
216
217static void initcall_debug_report(struct device *dev, ktime_t calltime,
218 void *cb, int error)
219{
220 ktime_t rettime;
221
222 if (!pm_print_times_enabled)
223 return;
224
225 rettime = ktime_get();
226 dev_info(dev, "%pS returned %d after %Ld usecs\n", cb, error,
227 (unsigned long long)ktime_us_delta(rettime, calltime));
228}
229
230/**
231 * dpm_wait - Wait for a PM operation to complete.
232 * @dev: Device to wait for.
233 * @async: If unset, wait only if the device's power.async_suspend flag is set.
234 */
235static void dpm_wait(struct device *dev, bool async)
236{
237 if (!dev)
238 return;
239
240 if (async || (pm_async_enabled && dev->power.async_suspend))
241 wait_for_completion(&dev->power.completion);
242}
243
244static int dpm_wait_fn(struct device *dev, void *async_ptr)
245{
246 dpm_wait(dev, *((bool *)async_ptr));
247 return 0;
248}
249
250static void dpm_wait_for_children(struct device *dev, bool async)
251{
252 device_for_each_child(dev, &async, dpm_wait_fn);
253}
254
255static void dpm_wait_for_suppliers(struct device *dev, bool async)
256{
257 struct device_link *link;
258 int idx;
259
260 idx = device_links_read_lock();
261
262 /*
263 * If the supplier goes away right after we've checked the link to it,
264 * we'll wait for its completion to change the state, but that's fine,
265 * because the only things that will block as a result are the SRCU
266 * callbacks freeing the link objects for the links in the list we're
267 * walking.
268 */
269 list_for_each_entry_rcu_locked(link, &dev->links.suppliers, c_node)
270 if (READ_ONCE(link->status) != DL_STATE_DORMANT)
271 dpm_wait(link->supplier, async);
272
273 device_links_read_unlock(idx);
274}
275
276static bool dpm_wait_for_superior(struct device *dev, bool async)
277{
278 struct device *parent;
279
280 /*
281 * If the device is resumed asynchronously and the parent's callback
282 * deletes both the device and the parent itself, the parent object may
283 * be freed while this function is running, so avoid that by reference
284 * counting the parent once more unless the device has been deleted
285 * already (in which case return right away).
286 */
287 mutex_lock(&dpm_list_mtx);
288
289 if (!device_pm_initialized(dev)) {
290 mutex_unlock(&dpm_list_mtx);
291 return false;
292 }
293
294 parent = get_device(dev->parent);
295
296 mutex_unlock(&dpm_list_mtx);
297
298 dpm_wait(parent, async);
299 put_device(parent);
300
301 dpm_wait_for_suppliers(dev, async);
302
303 /*
304 * If the parent's callback has deleted the device, attempting to resume
305 * it would be invalid, so avoid doing that then.
306 */
307 return device_pm_initialized(dev);
308}
309
310static void dpm_wait_for_consumers(struct device *dev, bool async)
311{
312 struct device_link *link;
313 int idx;
314
315 idx = device_links_read_lock();
316
317 /*
318 * The status of a device link can only be changed from "dormant" by a
319 * probe, but that cannot happen during system suspend/resume. In
320 * theory it can change to "dormant" at that time, but then it is
321 * reasonable to wait for the target device anyway (eg. if it goes
322 * away, it's better to wait for it to go away completely and then
323 * continue instead of trying to continue in parallel with its
324 * unregistration).
325 */
326 list_for_each_entry_rcu_locked(link, &dev->links.consumers, s_node)
327 if (READ_ONCE(link->status) != DL_STATE_DORMANT)
328 dpm_wait(link->consumer, async);
329
330 device_links_read_unlock(idx);
331}
332
333static void dpm_wait_for_subordinate(struct device *dev, bool async)
334{
335 dpm_wait_for_children(dev, async);
336 dpm_wait_for_consumers(dev, async);
337}
338
339/**
340 * pm_op - Return the PM operation appropriate for given PM event.
341 * @ops: PM operations to choose from.
342 * @state: PM transition of the system being carried out.
343 */
344static pm_callback_t pm_op(const struct dev_pm_ops *ops, pm_message_t state)
345{
346 switch (state.event) {
347#ifdef CONFIG_SUSPEND
348 case PM_EVENT_SUSPEND:
349 return ops->suspend;
350 case PM_EVENT_RESUME:
351 return ops->resume;
352#endif /* CONFIG_SUSPEND */
353#ifdef CONFIG_HIBERNATE_CALLBACKS
354 case PM_EVENT_FREEZE:
355 case PM_EVENT_QUIESCE:
356 return ops->freeze;
357 case PM_EVENT_HIBERNATE:
358 return ops->poweroff;
359 case PM_EVENT_THAW:
360 case PM_EVENT_RECOVER:
361 return ops->thaw;
362 case PM_EVENT_RESTORE:
363 return ops->restore;
364#endif /* CONFIG_HIBERNATE_CALLBACKS */
365 }
366
367 return NULL;
368}
369
370/**
371 * pm_late_early_op - Return the PM operation appropriate for given PM event.
372 * @ops: PM operations to choose from.
373 * @state: PM transition of the system being carried out.
374 *
375 * Runtime PM is disabled for @dev while this function is being executed.
376 */
377static pm_callback_t pm_late_early_op(const struct dev_pm_ops *ops,
378 pm_message_t state)
379{
380 switch (state.event) {
381#ifdef CONFIG_SUSPEND
382 case PM_EVENT_SUSPEND:
383 return ops->suspend_late;
384 case PM_EVENT_RESUME:
385 return ops->resume_early;
386#endif /* CONFIG_SUSPEND */
387#ifdef CONFIG_HIBERNATE_CALLBACKS
388 case PM_EVENT_FREEZE:
389 case PM_EVENT_QUIESCE:
390 return ops->freeze_late;
391 case PM_EVENT_HIBERNATE:
392 return ops->poweroff_late;
393 case PM_EVENT_THAW:
394 case PM_EVENT_RECOVER:
395 return ops->thaw_early;
396 case PM_EVENT_RESTORE:
397 return ops->restore_early;
398#endif /* CONFIG_HIBERNATE_CALLBACKS */
399 }
400
401 return NULL;
402}
403
404/**
405 * pm_noirq_op - Return the PM operation appropriate for given PM event.
406 * @ops: PM operations to choose from.
407 * @state: PM transition of the system being carried out.
408 *
409 * The driver of @dev will not receive interrupts while this function is being
410 * executed.
411 */
412static pm_callback_t pm_noirq_op(const struct dev_pm_ops *ops, pm_message_t state)
413{
414 switch (state.event) {
415#ifdef CONFIG_SUSPEND
416 case PM_EVENT_SUSPEND:
417 return ops->suspend_noirq;
418 case PM_EVENT_RESUME:
419 return ops->resume_noirq;
420#endif /* CONFIG_SUSPEND */
421#ifdef CONFIG_HIBERNATE_CALLBACKS
422 case PM_EVENT_FREEZE:
423 case PM_EVENT_QUIESCE:
424 return ops->freeze_noirq;
425 case PM_EVENT_HIBERNATE:
426 return ops->poweroff_noirq;
427 case PM_EVENT_THAW:
428 case PM_EVENT_RECOVER:
429 return ops->thaw_noirq;
430 case PM_EVENT_RESTORE:
431 return ops->restore_noirq;
432#endif /* CONFIG_HIBERNATE_CALLBACKS */
433 }
434
435 return NULL;
436}
437
438static void pm_dev_dbg(struct device *dev, pm_message_t state, const char *info)
439{
440 dev_dbg(dev, "%s%s%s driver flags: %x\n", info, pm_verb(state.event),
441 ((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
442 ", may wakeup" : "", dev->power.driver_flags);
443}
444
445static void pm_dev_err(struct device *dev, pm_message_t state, const char *info,
446 int error)
447{
448 dev_err(dev, "failed to %s%s: error %d\n", pm_verb(state.event), info,
449 error);
450}
451
452static void dpm_show_time(ktime_t starttime, pm_message_t state, int error,
453 const char *info)
454{
455 ktime_t calltime;
456 u64 usecs64;
457 int usecs;
458
459 calltime = ktime_get();
460 usecs64 = ktime_to_ns(ktime_sub(calltime, starttime));
461 do_div(usecs64, NSEC_PER_USEC);
462 usecs = usecs64;
463 if (usecs == 0)
464 usecs = 1;
465
466 pm_pr_dbg("%s%s%s of devices %s after %ld.%03ld msecs\n",
467 info ?: "", info ? " " : "", pm_verb(state.event),
468 error ? "aborted" : "complete",
469 usecs / USEC_PER_MSEC, usecs % USEC_PER_MSEC);
470}
471
472static int dpm_run_callback(pm_callback_t cb, struct device *dev,
473 pm_message_t state, const char *info)
474{
475 ktime_t calltime;
476 int error;
477
478 if (!cb)
479 return 0;
480
481 calltime = initcall_debug_start(dev, cb);
482
483 pm_dev_dbg(dev, state, info);
484 trace_device_pm_callback_start(dev, info, state.event);
485 error = cb(dev);
486 trace_device_pm_callback_end(dev, error);
487 suspend_report_result(dev, cb, error);
488
489 initcall_debug_report(dev, calltime, cb, error);
490
491 return error;
492}
493
494#ifdef CONFIG_DPM_WATCHDOG
495struct dpm_watchdog {
496 struct device *dev;
497 struct task_struct *tsk;
498 struct timer_list timer;
499};
500
501#define DECLARE_DPM_WATCHDOG_ON_STACK(wd) \
502 struct dpm_watchdog wd
503
504/**
505 * dpm_watchdog_handler - Driver suspend / resume watchdog handler.
506 * @t: The timer that PM watchdog depends on.
507 *
508 * Called when a driver has timed out suspending or resuming.
509 * There's not much we can do here to recover so panic() to
510 * capture a crash-dump in pstore.
511 */
512static void dpm_watchdog_handler(struct timer_list *t)
513{
514 struct dpm_watchdog *wd = from_timer(wd, t, timer);
515
516 dev_emerg(wd->dev, "**** DPM device timeout ****\n");
517 show_stack(wd->tsk, NULL, KERN_EMERG);
518 panic("%s %s: unrecoverable failure\n",
519 dev_driver_string(wd->dev), dev_name(wd->dev));
520}
521
522/**
523 * dpm_watchdog_set - Enable pm watchdog for given device.
524 * @wd: Watchdog. Must be allocated on the stack.
525 * @dev: Device to handle.
526 */
527static void dpm_watchdog_set(struct dpm_watchdog *wd, struct device *dev)
528{
529 struct timer_list *timer = &wd->timer;
530
531 wd->dev = dev;
532 wd->tsk = current;
533
534 timer_setup_on_stack(timer, dpm_watchdog_handler, 0);
535 /* use same timeout value for both suspend and resume */
536 timer->expires = jiffies + HZ * CONFIG_DPM_WATCHDOG_TIMEOUT;
537 add_timer(timer);
538}
539
540/**
541 * dpm_watchdog_clear - Disable suspend/resume watchdog.
542 * @wd: Watchdog to disable.
543 */
544static void dpm_watchdog_clear(struct dpm_watchdog *wd)
545{
546 struct timer_list *timer = &wd->timer;
547
548 del_timer_sync(timer);
549 destroy_timer_on_stack(timer);
550}
551#else
552#define DECLARE_DPM_WATCHDOG_ON_STACK(wd)
553#define dpm_watchdog_set(x, y)
554#define dpm_watchdog_clear(x)
555#endif
556
557/*------------------------- Resume routines -------------------------*/
558
559/**
560 * dev_pm_skip_resume - System-wide device resume optimization check.
561 * @dev: Target device.
562 *
563 * Return:
564 * - %false if the transition under way is RESTORE.
565 * - Return value of dev_pm_skip_suspend() if the transition under way is THAW.
566 * - The logical negation of %power.must_resume otherwise (that is, when the
567 * transition under way is RESUME).
568 */
569bool dev_pm_skip_resume(struct device *dev)
570{
571 if (pm_transition.event == PM_EVENT_RESTORE)
572 return false;
573
574 if (pm_transition.event == PM_EVENT_THAW)
575 return dev_pm_skip_suspend(dev);
576
577 return !dev->power.must_resume;
578}
579
580static bool is_async(struct device *dev)
581{
582 return dev->power.async_suspend && pm_async_enabled
583 && !pm_trace_is_enabled();
584}
585
586static bool dpm_async_fn(struct device *dev, async_func_t func)
587{
588 reinit_completion(&dev->power.completion);
589
590 if (is_async(dev)) {
591 dev->power.async_in_progress = true;
592
593 get_device(dev);
594
595 if (async_schedule_dev_nocall(func, dev))
596 return true;
597
598 put_device(dev);
599 }
600 /*
601 * Because async_schedule_dev_nocall() above has returned false or it
602 * has not been called at all, func() is not running and it is safe to
603 * update the async_in_progress flag without extra synchronization.
604 */
605 dev->power.async_in_progress = false;
606 return false;
607}
608
609/**
610 * device_resume_noirq - Execute a "noirq resume" callback for given device.
611 * @dev: Device to handle.
612 * @state: PM transition of the system being carried out.
613 * @async: If true, the device is being resumed asynchronously.
614 *
615 * The driver of @dev will not receive interrupts while this function is being
616 * executed.
617 */
618static void device_resume_noirq(struct device *dev, pm_message_t state, bool async)
619{
620 pm_callback_t callback = NULL;
621 const char *info = NULL;
622 bool skip_resume;
623 int error = 0;
624
625 TRACE_DEVICE(dev);
626 TRACE_RESUME(0);
627
628 if (dev->power.syscore || dev->power.direct_complete)
629 goto Out;
630
631 if (!dev->power.is_noirq_suspended)
632 goto Out;
633
634 if (!dpm_wait_for_superior(dev, async))
635 goto Out;
636
637 skip_resume = dev_pm_skip_resume(dev);
638 /*
639 * If the driver callback is skipped below or by the middle layer
640 * callback and device_resume_early() also skips the driver callback for
641 * this device later, it needs to appear as "suspended" to PM-runtime,
642 * so change its status accordingly.
643 *
644 * Otherwise, the device is going to be resumed, so set its PM-runtime
645 * status to "active", but do that only if DPM_FLAG_SMART_SUSPEND is set
646 * to avoid confusing drivers that don't use it.
647 */
648 if (skip_resume)
649 pm_runtime_set_suspended(dev);
650 else if (dev_pm_skip_suspend(dev))
651 pm_runtime_set_active(dev);
652
653 if (dev->pm_domain) {
654 info = "noirq power domain ";
655 callback = pm_noirq_op(&dev->pm_domain->ops, state);
656 } else if (dev->type && dev->type->pm) {
657 info = "noirq type ";
658 callback = pm_noirq_op(dev->type->pm, state);
659 } else if (dev->class && dev->class->pm) {
660 info = "noirq class ";
661 callback = pm_noirq_op(dev->class->pm, state);
662 } else if (dev->bus && dev->bus->pm) {
663 info = "noirq bus ";
664 callback = pm_noirq_op(dev->bus->pm, state);
665 }
666 if (callback)
667 goto Run;
668
669 if (skip_resume)
670 goto Skip;
671
672 if (dev->driver && dev->driver->pm) {
673 info = "noirq driver ";
674 callback = pm_noirq_op(dev->driver->pm, state);
675 }
676
677Run:
678 error = dpm_run_callback(callback, dev, state, info);
679
680Skip:
681 dev->power.is_noirq_suspended = false;
682
683Out:
684 complete_all(&dev->power.completion);
685 TRACE_RESUME(error);
686
687 if (error) {
688 async_error = error;
689 dpm_save_failed_dev(dev_name(dev));
690 pm_dev_err(dev, state, async ? " async noirq" : " noirq", error);
691 }
692}
693
694static void async_resume_noirq(void *data, async_cookie_t cookie)
695{
696 struct device *dev = data;
697
698 device_resume_noirq(dev, pm_transition, true);
699 put_device(dev);
700}
701
702static void dpm_noirq_resume_devices(pm_message_t state)
703{
704 struct device *dev;
705 ktime_t starttime = ktime_get();
706
707 trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, true);
708
709 async_error = 0;
710 pm_transition = state;
711
712 mutex_lock(&dpm_list_mtx);
713
714 /*
715 * Trigger the resume of "async" devices upfront so they don't have to
716 * wait for the "non-async" ones they don't depend on.
717 */
718 list_for_each_entry(dev, &dpm_noirq_list, power.entry)
719 dpm_async_fn(dev, async_resume_noirq);
720
721 while (!list_empty(&dpm_noirq_list)) {
722 dev = to_device(dpm_noirq_list.next);
723 list_move_tail(&dev->power.entry, &dpm_late_early_list);
724
725 if (!dev->power.async_in_progress) {
726 get_device(dev);
727
728 mutex_unlock(&dpm_list_mtx);
729
730 device_resume_noirq(dev, state, false);
731
732 put_device(dev);
733
734 mutex_lock(&dpm_list_mtx);
735 }
736 }
737 mutex_unlock(&dpm_list_mtx);
738 async_synchronize_full();
739 dpm_show_time(starttime, state, 0, "noirq");
740 if (async_error)
741 dpm_save_failed_step(SUSPEND_RESUME_NOIRQ);
742
743 trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, false);
744}
745
746/**
747 * dpm_resume_noirq - Execute "noirq resume" callbacks for all devices.
748 * @state: PM transition of the system being carried out.
749 *
750 * Invoke the "noirq" resume callbacks for all devices in dpm_noirq_list and
751 * allow device drivers' interrupt handlers to be called.
752 */
753void dpm_resume_noirq(pm_message_t state)
754{
755 dpm_noirq_resume_devices(state);
756
757 resume_device_irqs();
758 device_wakeup_disarm_wake_irqs();
759}
760
761/**
762 * device_resume_early - Execute an "early resume" callback for given device.
763 * @dev: Device to handle.
764 * @state: PM transition of the system being carried out.
765 * @async: If true, the device is being resumed asynchronously.
766 *
767 * Runtime PM is disabled for @dev while this function is being executed.
768 */
769static void device_resume_early(struct device *dev, pm_message_t state, bool async)
770{
771 pm_callback_t callback = NULL;
772 const char *info = NULL;
773 int error = 0;
774
775 TRACE_DEVICE(dev);
776 TRACE_RESUME(0);
777
778 if (dev->power.syscore || dev->power.direct_complete)
779 goto Out;
780
781 if (!dev->power.is_late_suspended)
782 goto Out;
783
784 if (!dpm_wait_for_superior(dev, async))
785 goto Out;
786
787 if (dev->pm_domain) {
788 info = "early power domain ";
789 callback = pm_late_early_op(&dev->pm_domain->ops, state);
790 } else if (dev->type && dev->type->pm) {
791 info = "early type ";
792 callback = pm_late_early_op(dev->type->pm, state);
793 } else if (dev->class && dev->class->pm) {
794 info = "early class ";
795 callback = pm_late_early_op(dev->class->pm, state);
796 } else if (dev->bus && dev->bus->pm) {
797 info = "early bus ";
798 callback = pm_late_early_op(dev->bus->pm, state);
799 }
800 if (callback)
801 goto Run;
802
803 if (dev_pm_skip_resume(dev))
804 goto Skip;
805
806 if (dev->driver && dev->driver->pm) {
807 info = "early driver ";
808 callback = pm_late_early_op(dev->driver->pm, state);
809 }
810
811Run:
812 error = dpm_run_callback(callback, dev, state, info);
813
814Skip:
815 dev->power.is_late_suspended = false;
816
817Out:
818 TRACE_RESUME(error);
819
820 pm_runtime_enable(dev);
821 complete_all(&dev->power.completion);
822
823 if (error) {
824 async_error = error;
825 dpm_save_failed_dev(dev_name(dev));
826 pm_dev_err(dev, state, async ? " async early" : " early", error);
827 }
828}
829
830static void async_resume_early(void *data, async_cookie_t cookie)
831{
832 struct device *dev = data;
833
834 device_resume_early(dev, pm_transition, true);
835 put_device(dev);
836}
837
838/**
839 * dpm_resume_early - Execute "early resume" callbacks for all devices.
840 * @state: PM transition of the system being carried out.
841 */
842void dpm_resume_early(pm_message_t state)
843{
844 struct device *dev;
845 ktime_t starttime = ktime_get();
846
847 trace_suspend_resume(TPS("dpm_resume_early"), state.event, true);
848
849 async_error = 0;
850 pm_transition = state;
851
852 mutex_lock(&dpm_list_mtx);
853
854 /*
855 * Trigger the resume of "async" devices upfront so they don't have to
856 * wait for the "non-async" ones they don't depend on.
857 */
858 list_for_each_entry(dev, &dpm_late_early_list, power.entry)
859 dpm_async_fn(dev, async_resume_early);
860
861 while (!list_empty(&dpm_late_early_list)) {
862 dev = to_device(dpm_late_early_list.next);
863 list_move_tail(&dev->power.entry, &dpm_suspended_list);
864
865 if (!dev->power.async_in_progress) {
866 get_device(dev);
867
868 mutex_unlock(&dpm_list_mtx);
869
870 device_resume_early(dev, state, false);
871
872 put_device(dev);
873
874 mutex_lock(&dpm_list_mtx);
875 }
876 }
877 mutex_unlock(&dpm_list_mtx);
878 async_synchronize_full();
879 dpm_show_time(starttime, state, 0, "early");
880 if (async_error)
881 dpm_save_failed_step(SUSPEND_RESUME_EARLY);
882
883 trace_suspend_resume(TPS("dpm_resume_early"), state.event, false);
884}
885
886/**
887 * dpm_resume_start - Execute "noirq" and "early" device callbacks.
888 * @state: PM transition of the system being carried out.
889 */
890void dpm_resume_start(pm_message_t state)
891{
892 dpm_resume_noirq(state);
893 dpm_resume_early(state);
894}
895EXPORT_SYMBOL_GPL(dpm_resume_start);
896
897/**
898 * device_resume - Execute "resume" callbacks for given device.
899 * @dev: Device to handle.
900 * @state: PM transition of the system being carried out.
901 * @async: If true, the device is being resumed asynchronously.
902 */
903static void device_resume(struct device *dev, pm_message_t state, bool async)
904{
905 pm_callback_t callback = NULL;
906 const char *info = NULL;
907 int error = 0;
908 DECLARE_DPM_WATCHDOG_ON_STACK(wd);
909
910 TRACE_DEVICE(dev);
911 TRACE_RESUME(0);
912
913 if (dev->power.syscore)
914 goto Complete;
915
916 if (dev->power.direct_complete) {
917 /* Match the pm_runtime_disable() in __device_suspend(). */
918 pm_runtime_enable(dev);
919 goto Complete;
920 }
921
922 if (!dpm_wait_for_superior(dev, async))
923 goto Complete;
924
925 dpm_watchdog_set(&wd, dev);
926 device_lock(dev);
927
928 /*
929 * This is a fib. But we'll allow new children to be added below
930 * a resumed device, even if the device hasn't been completed yet.
931 */
932 dev->power.is_prepared = false;
933
934 if (!dev->power.is_suspended)
935 goto Unlock;
936
937 if (dev->pm_domain) {
938 info = "power domain ";
939 callback = pm_op(&dev->pm_domain->ops, state);
940 goto Driver;
941 }
942
943 if (dev->type && dev->type->pm) {
944 info = "type ";
945 callback = pm_op(dev->type->pm, state);
946 goto Driver;
947 }
948
949 if (dev->class && dev->class->pm) {
950 info = "class ";
951 callback = pm_op(dev->class->pm, state);
952 goto Driver;
953 }
954
955 if (dev->bus) {
956 if (dev->bus->pm) {
957 info = "bus ";
958 callback = pm_op(dev->bus->pm, state);
959 } else if (dev->bus->resume) {
960 info = "legacy bus ";
961 callback = dev->bus->resume;
962 goto End;
963 }
964 }
965
966 Driver:
967 if (!callback && dev->driver && dev->driver->pm) {
968 info = "driver ";
969 callback = pm_op(dev->driver->pm, state);
970 }
971
972 End:
973 error = dpm_run_callback(callback, dev, state, info);
974 dev->power.is_suspended = false;
975
976 Unlock:
977 device_unlock(dev);
978 dpm_watchdog_clear(&wd);
979
980 Complete:
981 complete_all(&dev->power.completion);
982
983 TRACE_RESUME(error);
984
985 if (error) {
986 async_error = error;
987 dpm_save_failed_dev(dev_name(dev));
988 pm_dev_err(dev, state, async ? " async" : "", error);
989 }
990}
991
992static void async_resume(void *data, async_cookie_t cookie)
993{
994 struct device *dev = data;
995
996 device_resume(dev, pm_transition, true);
997 put_device(dev);
998}
999
1000/**
1001 * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
1002 * @state: PM transition of the system being carried out.
1003 *
1004 * Execute the appropriate "resume" callback for all devices whose status
1005 * indicates that they are suspended.
1006 */
1007void dpm_resume(pm_message_t state)
1008{
1009 struct device *dev;
1010 ktime_t starttime = ktime_get();
1011
1012 trace_suspend_resume(TPS("dpm_resume"), state.event, true);
1013 might_sleep();
1014
1015 pm_transition = state;
1016 async_error = 0;
1017
1018 mutex_lock(&dpm_list_mtx);
1019
1020 /*
1021 * Trigger the resume of "async" devices upfront so they don't have to
1022 * wait for the "non-async" ones they don't depend on.
1023 */
1024 list_for_each_entry(dev, &dpm_suspended_list, power.entry)
1025 dpm_async_fn(dev, async_resume);
1026
1027 while (!list_empty(&dpm_suspended_list)) {
1028 dev = to_device(dpm_suspended_list.next);
1029 list_move_tail(&dev->power.entry, &dpm_prepared_list);
1030
1031 if (!dev->power.async_in_progress) {
1032 get_device(dev);
1033
1034 mutex_unlock(&dpm_list_mtx);
1035
1036 device_resume(dev, state, false);
1037
1038 put_device(dev);
1039
1040 mutex_lock(&dpm_list_mtx);
1041 }
1042 }
1043 mutex_unlock(&dpm_list_mtx);
1044 async_synchronize_full();
1045 dpm_show_time(starttime, state, 0, NULL);
1046 if (async_error)
1047 dpm_save_failed_step(SUSPEND_RESUME);
1048
1049 cpufreq_resume();
1050 devfreq_resume();
1051 trace_suspend_resume(TPS("dpm_resume"), state.event, false);
1052}
1053
1054/**
1055 * device_complete - Complete a PM transition for given device.
1056 * @dev: Device to handle.
1057 * @state: PM transition of the system being carried out.
1058 */
1059static void device_complete(struct device *dev, pm_message_t state)
1060{
1061 void (*callback)(struct device *) = NULL;
1062 const char *info = NULL;
1063
1064 if (dev->power.syscore)
1065 goto out;
1066
1067 device_lock(dev);
1068
1069 if (dev->pm_domain) {
1070 info = "completing power domain ";
1071 callback = dev->pm_domain->ops.complete;
1072 } else if (dev->type && dev->type->pm) {
1073 info = "completing type ";
1074 callback = dev->type->pm->complete;
1075 } else if (dev->class && dev->class->pm) {
1076 info = "completing class ";
1077 callback = dev->class->pm->complete;
1078 } else if (dev->bus && dev->bus->pm) {
1079 info = "completing bus ";
1080 callback = dev->bus->pm->complete;
1081 }
1082
1083 if (!callback && dev->driver && dev->driver->pm) {
1084 info = "completing driver ";
1085 callback = dev->driver->pm->complete;
1086 }
1087
1088 if (callback) {
1089 pm_dev_dbg(dev, state, info);
1090 callback(dev);
1091 }
1092
1093 device_unlock(dev);
1094
1095out:
1096 pm_runtime_put(dev);
1097}
1098
1099/**
1100 * dpm_complete - Complete a PM transition for all non-sysdev devices.
1101 * @state: PM transition of the system being carried out.
1102 *
1103 * Execute the ->complete() callbacks for all devices whose PM status is not
1104 * DPM_ON (this allows new devices to be registered).
1105 */
1106void dpm_complete(pm_message_t state)
1107{
1108 struct list_head list;
1109
1110 trace_suspend_resume(TPS("dpm_complete"), state.event, true);
1111 might_sleep();
1112
1113 INIT_LIST_HEAD(&list);
1114 mutex_lock(&dpm_list_mtx);
1115 while (!list_empty(&dpm_prepared_list)) {
1116 struct device *dev = to_device(dpm_prepared_list.prev);
1117
1118 get_device(dev);
1119 dev->power.is_prepared = false;
1120 list_move(&dev->power.entry, &list);
1121
1122 mutex_unlock(&dpm_list_mtx);
1123
1124 trace_device_pm_callback_start(dev, "", state.event);
1125 device_complete(dev, state);
1126 trace_device_pm_callback_end(dev, 0);
1127
1128 put_device(dev);
1129
1130 mutex_lock(&dpm_list_mtx);
1131 }
1132 list_splice(&list, &dpm_list);
1133 mutex_unlock(&dpm_list_mtx);
1134
1135 /* Allow device probing and trigger re-probing of deferred devices */
1136 device_unblock_probing();
1137 trace_suspend_resume(TPS("dpm_complete"), state.event, false);
1138}
1139
1140/**
1141 * dpm_resume_end - Execute "resume" callbacks and complete system transition.
1142 * @state: PM transition of the system being carried out.
1143 *
1144 * Execute "resume" callbacks for all devices and complete the PM transition of
1145 * the system.
1146 */
1147void dpm_resume_end(pm_message_t state)
1148{
1149 dpm_resume(state);
1150 dpm_complete(state);
1151}
1152EXPORT_SYMBOL_GPL(dpm_resume_end);
1153
1154
1155/*------------------------- Suspend routines -------------------------*/
1156
1157/**
1158 * resume_event - Return a "resume" message for given "suspend" sleep state.
1159 * @sleep_state: PM message representing a sleep state.
1160 *
1161 * Return a PM message representing the resume event corresponding to given
1162 * sleep state.
1163 */
1164static pm_message_t resume_event(pm_message_t sleep_state)
1165{
1166 switch (sleep_state.event) {
1167 case PM_EVENT_SUSPEND:
1168 return PMSG_RESUME;
1169 case PM_EVENT_FREEZE:
1170 case PM_EVENT_QUIESCE:
1171 return PMSG_RECOVER;
1172 case PM_EVENT_HIBERNATE:
1173 return PMSG_RESTORE;
1174 }
1175 return PMSG_ON;
1176}
1177
1178static void dpm_superior_set_must_resume(struct device *dev)
1179{
1180 struct device_link *link;
1181 int idx;
1182
1183 if (dev->parent)
1184 dev->parent->power.must_resume = true;
1185
1186 idx = device_links_read_lock();
1187
1188 list_for_each_entry_rcu_locked(link, &dev->links.suppliers, c_node)
1189 link->supplier->power.must_resume = true;
1190
1191 device_links_read_unlock(idx);
1192}
1193
1194/**
1195 * device_suspend_noirq - Execute a "noirq suspend" callback for given device.
1196 * @dev: Device to handle.
1197 * @state: PM transition of the system being carried out.
1198 * @async: If true, the device is being suspended asynchronously.
1199 *
1200 * The driver of @dev will not receive interrupts while this function is being
1201 * executed.
1202 */
1203static int device_suspend_noirq(struct device *dev, pm_message_t state, bool async)
1204{
1205 pm_callback_t callback = NULL;
1206 const char *info = NULL;
1207 int error = 0;
1208
1209 TRACE_DEVICE(dev);
1210 TRACE_SUSPEND(0);
1211
1212 dpm_wait_for_subordinate(dev, async);
1213
1214 if (async_error)
1215 goto Complete;
1216
1217 if (dev->power.syscore || dev->power.direct_complete)
1218 goto Complete;
1219
1220 if (dev->pm_domain) {
1221 info = "noirq power domain ";
1222 callback = pm_noirq_op(&dev->pm_domain->ops, state);
1223 } else if (dev->type && dev->type->pm) {
1224 info = "noirq type ";
1225 callback = pm_noirq_op(dev->type->pm, state);
1226 } else if (dev->class && dev->class->pm) {
1227 info = "noirq class ";
1228 callback = pm_noirq_op(dev->class->pm, state);
1229 } else if (dev->bus && dev->bus->pm) {
1230 info = "noirq bus ";
1231 callback = pm_noirq_op(dev->bus->pm, state);
1232 }
1233 if (callback)
1234 goto Run;
1235
1236 if (dev_pm_skip_suspend(dev))
1237 goto Skip;
1238
1239 if (dev->driver && dev->driver->pm) {
1240 info = "noirq driver ";
1241 callback = pm_noirq_op(dev->driver->pm, state);
1242 }
1243
1244Run:
1245 error = dpm_run_callback(callback, dev, state, info);
1246 if (error) {
1247 async_error = error;
1248 dpm_save_failed_dev(dev_name(dev));
1249 pm_dev_err(dev, state, async ? " async noirq" : " noirq", error);
1250 goto Complete;
1251 }
1252
1253Skip:
1254 dev->power.is_noirq_suspended = true;
1255
1256 /*
1257 * Skipping the resume of devices that were in use right before the
1258 * system suspend (as indicated by their PM-runtime usage counters)
1259 * would be suboptimal. Also resume them if doing that is not allowed
1260 * to be skipped.
1261 */
1262 if (atomic_read(&dev->power.usage_count) > 1 ||
1263 !(dev_pm_test_driver_flags(dev, DPM_FLAG_MAY_SKIP_RESUME) &&
1264 dev->power.may_skip_resume))
1265 dev->power.must_resume = true;
1266
1267 if (dev->power.must_resume)
1268 dpm_superior_set_must_resume(dev);
1269
1270Complete:
1271 complete_all(&dev->power.completion);
1272 TRACE_SUSPEND(error);
1273 return error;
1274}
1275
1276static void async_suspend_noirq(void *data, async_cookie_t cookie)
1277{
1278 struct device *dev = data;
1279
1280 device_suspend_noirq(dev, pm_transition, true);
1281 put_device(dev);
1282}
1283
1284static int dpm_noirq_suspend_devices(pm_message_t state)
1285{
1286 ktime_t starttime = ktime_get();
1287 int error = 0;
1288
1289 trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, true);
1290
1291 pm_transition = state;
1292 async_error = 0;
1293
1294 mutex_lock(&dpm_list_mtx);
1295
1296 while (!list_empty(&dpm_late_early_list)) {
1297 struct device *dev = to_device(dpm_late_early_list.prev);
1298
1299 list_move(&dev->power.entry, &dpm_noirq_list);
1300
1301 if (dpm_async_fn(dev, async_suspend_noirq))
1302 continue;
1303
1304 get_device(dev);
1305
1306 mutex_unlock(&dpm_list_mtx);
1307
1308 error = device_suspend_noirq(dev, state, false);
1309
1310 put_device(dev);
1311
1312 mutex_lock(&dpm_list_mtx);
1313
1314 if (error || async_error)
1315 break;
1316 }
1317
1318 mutex_unlock(&dpm_list_mtx);
1319
1320 async_synchronize_full();
1321 if (!error)
1322 error = async_error;
1323
1324 if (error)
1325 dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ);
1326
1327 dpm_show_time(starttime, state, error, "noirq");
1328 trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, false);
1329 return error;
1330}
1331
1332/**
1333 * dpm_suspend_noirq - Execute "noirq suspend" callbacks for all devices.
1334 * @state: PM transition of the system being carried out.
1335 *
1336 * Prevent device drivers' interrupt handlers from being called and invoke
1337 * "noirq" suspend callbacks for all non-sysdev devices.
1338 */
1339int dpm_suspend_noirq(pm_message_t state)
1340{
1341 int ret;
1342
1343 device_wakeup_arm_wake_irqs();
1344 suspend_device_irqs();
1345
1346 ret = dpm_noirq_suspend_devices(state);
1347 if (ret)
1348 dpm_resume_noirq(resume_event(state));
1349
1350 return ret;
1351}
1352
1353static void dpm_propagate_wakeup_to_parent(struct device *dev)
1354{
1355 struct device *parent = dev->parent;
1356
1357 if (!parent)
1358 return;
1359
1360 spin_lock_irq(&parent->power.lock);
1361
1362 if (device_wakeup_path(dev) && !parent->power.ignore_children)
1363 parent->power.wakeup_path = true;
1364
1365 spin_unlock_irq(&parent->power.lock);
1366}
1367
1368/**
1369 * device_suspend_late - Execute a "late suspend" callback for given device.
1370 * @dev: Device to handle.
1371 * @state: PM transition of the system being carried out.
1372 * @async: If true, the device is being suspended asynchronously.
1373 *
1374 * Runtime PM is disabled for @dev while this function is being executed.
1375 */
1376static int device_suspend_late(struct device *dev, pm_message_t state, bool async)
1377{
1378 pm_callback_t callback = NULL;
1379 const char *info = NULL;
1380 int error = 0;
1381
1382 TRACE_DEVICE(dev);
1383 TRACE_SUSPEND(0);
1384
1385 __pm_runtime_disable(dev, false);
1386
1387 dpm_wait_for_subordinate(dev, async);
1388
1389 if (async_error)
1390 goto Complete;
1391
1392 if (pm_wakeup_pending()) {
1393 async_error = -EBUSY;
1394 goto Complete;
1395 }
1396
1397 if (dev->power.syscore || dev->power.direct_complete)
1398 goto Complete;
1399
1400 if (dev->pm_domain) {
1401 info = "late power domain ";
1402 callback = pm_late_early_op(&dev->pm_domain->ops, state);
1403 } else if (dev->type && dev->type->pm) {
1404 info = "late type ";
1405 callback = pm_late_early_op(dev->type->pm, state);
1406 } else if (dev->class && dev->class->pm) {
1407 info = "late class ";
1408 callback = pm_late_early_op(dev->class->pm, state);
1409 } else if (dev->bus && dev->bus->pm) {
1410 info = "late bus ";
1411 callback = pm_late_early_op(dev->bus->pm, state);
1412 }
1413 if (callback)
1414 goto Run;
1415
1416 if (dev_pm_skip_suspend(dev))
1417 goto Skip;
1418
1419 if (dev->driver && dev->driver->pm) {
1420 info = "late driver ";
1421 callback = pm_late_early_op(dev->driver->pm, state);
1422 }
1423
1424Run:
1425 error = dpm_run_callback(callback, dev, state, info);
1426 if (error) {
1427 async_error = error;
1428 dpm_save_failed_dev(dev_name(dev));
1429 pm_dev_err(dev, state, async ? " async late" : " late", error);
1430 goto Complete;
1431 }
1432 dpm_propagate_wakeup_to_parent(dev);
1433
1434Skip:
1435 dev->power.is_late_suspended = true;
1436
1437Complete:
1438 TRACE_SUSPEND(error);
1439 complete_all(&dev->power.completion);
1440 return error;
1441}
1442
1443static void async_suspend_late(void *data, async_cookie_t cookie)
1444{
1445 struct device *dev = data;
1446
1447 device_suspend_late(dev, pm_transition, true);
1448 put_device(dev);
1449}
1450
1451/**
1452 * dpm_suspend_late - Execute "late suspend" callbacks for all devices.
1453 * @state: PM transition of the system being carried out.
1454 */
1455int dpm_suspend_late(pm_message_t state)
1456{
1457 ktime_t starttime = ktime_get();
1458 int error = 0;
1459
1460 trace_suspend_resume(TPS("dpm_suspend_late"), state.event, true);
1461
1462 pm_transition = state;
1463 async_error = 0;
1464
1465 wake_up_all_idle_cpus();
1466
1467 mutex_lock(&dpm_list_mtx);
1468
1469 while (!list_empty(&dpm_suspended_list)) {
1470 struct device *dev = to_device(dpm_suspended_list.prev);
1471
1472 list_move(&dev->power.entry, &dpm_late_early_list);
1473
1474 if (dpm_async_fn(dev, async_suspend_late))
1475 continue;
1476
1477 get_device(dev);
1478
1479 mutex_unlock(&dpm_list_mtx);
1480
1481 error = device_suspend_late(dev, state, false);
1482
1483 put_device(dev);
1484
1485 mutex_lock(&dpm_list_mtx);
1486
1487 if (error || async_error)
1488 break;
1489 }
1490
1491 mutex_unlock(&dpm_list_mtx);
1492
1493 async_synchronize_full();
1494 if (!error)
1495 error = async_error;
1496
1497 if (error) {
1498 dpm_save_failed_step(SUSPEND_SUSPEND_LATE);
1499 dpm_resume_early(resume_event(state));
1500 }
1501 dpm_show_time(starttime, state, error, "late");
1502 trace_suspend_resume(TPS("dpm_suspend_late"), state.event, false);
1503 return error;
1504}
1505
1506/**
1507 * dpm_suspend_end - Execute "late" and "noirq" device suspend callbacks.
1508 * @state: PM transition of the system being carried out.
1509 */
1510int dpm_suspend_end(pm_message_t state)
1511{
1512 ktime_t starttime = ktime_get();
1513 int error;
1514
1515 error = dpm_suspend_late(state);
1516 if (error)
1517 goto out;
1518
1519 error = dpm_suspend_noirq(state);
1520 if (error)
1521 dpm_resume_early(resume_event(state));
1522
1523out:
1524 dpm_show_time(starttime, state, error, "end");
1525 return error;
1526}
1527EXPORT_SYMBOL_GPL(dpm_suspend_end);
1528
1529/**
1530 * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
1531 * @dev: Device to suspend.
1532 * @state: PM transition of the system being carried out.
1533 * @cb: Suspend callback to execute.
1534 * @info: string description of caller.
1535 */
1536static int legacy_suspend(struct device *dev, pm_message_t state,
1537 int (*cb)(struct device *dev, pm_message_t state),
1538 const char *info)
1539{
1540 int error;
1541 ktime_t calltime;
1542
1543 calltime = initcall_debug_start(dev, cb);
1544
1545 trace_device_pm_callback_start(dev, info, state.event);
1546 error = cb(dev, state);
1547 trace_device_pm_callback_end(dev, error);
1548 suspend_report_result(dev, cb, error);
1549
1550 initcall_debug_report(dev, calltime, cb, error);
1551
1552 return error;
1553}
1554
1555static void dpm_clear_superiors_direct_complete(struct device *dev)
1556{
1557 struct device_link *link;
1558 int idx;
1559
1560 if (dev->parent) {
1561 spin_lock_irq(&dev->parent->power.lock);
1562 dev->parent->power.direct_complete = false;
1563 spin_unlock_irq(&dev->parent->power.lock);
1564 }
1565
1566 idx = device_links_read_lock();
1567
1568 list_for_each_entry_rcu_locked(link, &dev->links.suppliers, c_node) {
1569 spin_lock_irq(&link->supplier->power.lock);
1570 link->supplier->power.direct_complete = false;
1571 spin_unlock_irq(&link->supplier->power.lock);
1572 }
1573
1574 device_links_read_unlock(idx);
1575}
1576
1577/**
1578 * device_suspend - Execute "suspend" callbacks for given device.
1579 * @dev: Device to handle.
1580 * @state: PM transition of the system being carried out.
1581 * @async: If true, the device is being suspended asynchronously.
1582 */
1583static int device_suspend(struct device *dev, pm_message_t state, bool async)
1584{
1585 pm_callback_t callback = NULL;
1586 const char *info = NULL;
1587 int error = 0;
1588 DECLARE_DPM_WATCHDOG_ON_STACK(wd);
1589
1590 TRACE_DEVICE(dev);
1591 TRACE_SUSPEND(0);
1592
1593 dpm_wait_for_subordinate(dev, async);
1594
1595 if (async_error) {
1596 dev->power.direct_complete = false;
1597 goto Complete;
1598 }
1599
1600 /*
1601 * Wait for possible runtime PM transitions of the device in progress
1602 * to complete and if there's a runtime resume request pending for it,
1603 * resume it before proceeding with invoking the system-wide suspend
1604 * callbacks for it.
1605 *
1606 * If the system-wide suspend callbacks below change the configuration
1607 * of the device, they must disable runtime PM for it or otherwise
1608 * ensure that its runtime-resume callbacks will not be confused by that
1609 * change in case they are invoked going forward.
1610 */
1611 pm_runtime_barrier(dev);
1612
1613 if (pm_wakeup_pending()) {
1614 dev->power.direct_complete = false;
1615 async_error = -EBUSY;
1616 goto Complete;
1617 }
1618
1619 if (dev->power.syscore)
1620 goto Complete;
1621
1622 /* Avoid direct_complete to let wakeup_path propagate. */
1623 if (device_may_wakeup(dev) || device_wakeup_path(dev))
1624 dev->power.direct_complete = false;
1625
1626 if (dev->power.direct_complete) {
1627 if (pm_runtime_status_suspended(dev)) {
1628 pm_runtime_disable(dev);
1629 if (pm_runtime_status_suspended(dev)) {
1630 pm_dev_dbg(dev, state, "direct-complete ");
1631 goto Complete;
1632 }
1633
1634 pm_runtime_enable(dev);
1635 }
1636 dev->power.direct_complete = false;
1637 }
1638
1639 dev->power.may_skip_resume = true;
1640 dev->power.must_resume = !dev_pm_test_driver_flags(dev, DPM_FLAG_MAY_SKIP_RESUME);
1641
1642 dpm_watchdog_set(&wd, dev);
1643 device_lock(dev);
1644
1645 if (dev->pm_domain) {
1646 info = "power domain ";
1647 callback = pm_op(&dev->pm_domain->ops, state);
1648 goto Run;
1649 }
1650
1651 if (dev->type && dev->type->pm) {
1652 info = "type ";
1653 callback = pm_op(dev->type->pm, state);
1654 goto Run;
1655 }
1656
1657 if (dev->class && dev->class->pm) {
1658 info = "class ";
1659 callback = pm_op(dev->class->pm, state);
1660 goto Run;
1661 }
1662
1663 if (dev->bus) {
1664 if (dev->bus->pm) {
1665 info = "bus ";
1666 callback = pm_op(dev->bus->pm, state);
1667 } else if (dev->bus->suspend) {
1668 pm_dev_dbg(dev, state, "legacy bus ");
1669 error = legacy_suspend(dev, state, dev->bus->suspend,
1670 "legacy bus ");
1671 goto End;
1672 }
1673 }
1674
1675 Run:
1676 if (!callback && dev->driver && dev->driver->pm) {
1677 info = "driver ";
1678 callback = pm_op(dev->driver->pm, state);
1679 }
1680
1681 error = dpm_run_callback(callback, dev, state, info);
1682
1683 End:
1684 if (!error) {
1685 dev->power.is_suspended = true;
1686 if (device_may_wakeup(dev))
1687 dev->power.wakeup_path = true;
1688
1689 dpm_propagate_wakeup_to_parent(dev);
1690 dpm_clear_superiors_direct_complete(dev);
1691 }
1692
1693 device_unlock(dev);
1694 dpm_watchdog_clear(&wd);
1695
1696 Complete:
1697 if (error) {
1698 async_error = error;
1699 dpm_save_failed_dev(dev_name(dev));
1700 pm_dev_err(dev, state, async ? " async" : "", error);
1701 }
1702
1703 complete_all(&dev->power.completion);
1704 TRACE_SUSPEND(error);
1705 return error;
1706}
1707
1708static void async_suspend(void *data, async_cookie_t cookie)
1709{
1710 struct device *dev = data;
1711
1712 device_suspend(dev, pm_transition, true);
1713 put_device(dev);
1714}
1715
1716/**
1717 * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
1718 * @state: PM transition of the system being carried out.
1719 */
1720int dpm_suspend(pm_message_t state)
1721{
1722 ktime_t starttime = ktime_get();
1723 int error = 0;
1724
1725 trace_suspend_resume(TPS("dpm_suspend"), state.event, true);
1726 might_sleep();
1727
1728 devfreq_suspend();
1729 cpufreq_suspend();
1730
1731 pm_transition = state;
1732 async_error = 0;
1733
1734 mutex_lock(&dpm_list_mtx);
1735
1736 while (!list_empty(&dpm_prepared_list)) {
1737 struct device *dev = to_device(dpm_prepared_list.prev);
1738
1739 list_move(&dev->power.entry, &dpm_suspended_list);
1740
1741 if (dpm_async_fn(dev, async_suspend))
1742 continue;
1743
1744 get_device(dev);
1745
1746 mutex_unlock(&dpm_list_mtx);
1747
1748 error = device_suspend(dev, state, false);
1749
1750 put_device(dev);
1751
1752 mutex_lock(&dpm_list_mtx);
1753
1754 if (error || async_error)
1755 break;
1756 }
1757
1758 mutex_unlock(&dpm_list_mtx);
1759
1760 async_synchronize_full();
1761 if (!error)
1762 error = async_error;
1763
1764 if (error)
1765 dpm_save_failed_step(SUSPEND_SUSPEND);
1766
1767 dpm_show_time(starttime, state, error, NULL);
1768 trace_suspend_resume(TPS("dpm_suspend"), state.event, false);
1769 return error;
1770}
1771
1772/**
1773 * device_prepare - Prepare a device for system power transition.
1774 * @dev: Device to handle.
1775 * @state: PM transition of the system being carried out.
1776 *
1777 * Execute the ->prepare() callback(s) for given device. No new children of the
1778 * device may be registered after this function has returned.
1779 */
1780static int device_prepare(struct device *dev, pm_message_t state)
1781{
1782 int (*callback)(struct device *) = NULL;
1783 int ret = 0;
1784
1785 /*
1786 * If a device's parent goes into runtime suspend at the wrong time,
1787 * it won't be possible to resume the device. To prevent this we
1788 * block runtime suspend here, during the prepare phase, and allow
1789 * it again during the complete phase.
1790 */
1791 pm_runtime_get_noresume(dev);
1792
1793 if (dev->power.syscore)
1794 return 0;
1795
1796 device_lock(dev);
1797
1798 dev->power.wakeup_path = false;
1799
1800 if (dev->power.no_pm_callbacks)
1801 goto unlock;
1802
1803 if (dev->pm_domain)
1804 callback = dev->pm_domain->ops.prepare;
1805 else if (dev->type && dev->type->pm)
1806 callback = dev->type->pm->prepare;
1807 else if (dev->class && dev->class->pm)
1808 callback = dev->class->pm->prepare;
1809 else if (dev->bus && dev->bus->pm)
1810 callback = dev->bus->pm->prepare;
1811
1812 if (!callback && dev->driver && dev->driver->pm)
1813 callback = dev->driver->pm->prepare;
1814
1815 if (callback)
1816 ret = callback(dev);
1817
1818unlock:
1819 device_unlock(dev);
1820
1821 if (ret < 0) {
1822 suspend_report_result(dev, callback, ret);
1823 pm_runtime_put(dev);
1824 return ret;
1825 }
1826 /*
1827 * A positive return value from ->prepare() means "this device appears
1828 * to be runtime-suspended and its state is fine, so if it really is
1829 * runtime-suspended, you can leave it in that state provided that you
1830 * will do the same thing with all of its descendants". This only
1831 * applies to suspend transitions, however.
1832 */
1833 spin_lock_irq(&dev->power.lock);
1834 dev->power.direct_complete = state.event == PM_EVENT_SUSPEND &&
1835 (ret > 0 || dev->power.no_pm_callbacks) &&
1836 !dev_pm_test_driver_flags(dev, DPM_FLAG_NO_DIRECT_COMPLETE);
1837 spin_unlock_irq(&dev->power.lock);
1838 return 0;
1839}
1840
1841/**
1842 * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1843 * @state: PM transition of the system being carried out.
1844 *
1845 * Execute the ->prepare() callback(s) for all devices.
1846 */
1847int dpm_prepare(pm_message_t state)
1848{
1849 int error = 0;
1850
1851 trace_suspend_resume(TPS("dpm_prepare"), state.event, true);
1852 might_sleep();
1853
1854 /*
1855 * Give a chance for the known devices to complete their probes, before
1856 * disable probing of devices. This sync point is important at least
1857 * at boot time + hibernation restore.
1858 */
1859 wait_for_device_probe();
1860 /*
1861 * It is unsafe if probing of devices will happen during suspend or
1862 * hibernation and system behavior will be unpredictable in this case.
1863 * So, let's prohibit device's probing here and defer their probes
1864 * instead. The normal behavior will be restored in dpm_complete().
1865 */
1866 device_block_probing();
1867
1868 mutex_lock(&dpm_list_mtx);
1869 while (!list_empty(&dpm_list) && !error) {
1870 struct device *dev = to_device(dpm_list.next);
1871
1872 get_device(dev);
1873
1874 mutex_unlock(&dpm_list_mtx);
1875
1876 trace_device_pm_callback_start(dev, "", state.event);
1877 error = device_prepare(dev, state);
1878 trace_device_pm_callback_end(dev, error);
1879
1880 mutex_lock(&dpm_list_mtx);
1881
1882 if (!error) {
1883 dev->power.is_prepared = true;
1884 if (!list_empty(&dev->power.entry))
1885 list_move_tail(&dev->power.entry, &dpm_prepared_list);
1886 } else if (error == -EAGAIN) {
1887 error = 0;
1888 } else {
1889 dev_info(dev, "not prepared for power transition: code %d\n",
1890 error);
1891 }
1892
1893 mutex_unlock(&dpm_list_mtx);
1894
1895 put_device(dev);
1896
1897 mutex_lock(&dpm_list_mtx);
1898 }
1899 mutex_unlock(&dpm_list_mtx);
1900 trace_suspend_resume(TPS("dpm_prepare"), state.event, false);
1901 return error;
1902}
1903
1904/**
1905 * dpm_suspend_start - Prepare devices for PM transition and suspend them.
1906 * @state: PM transition of the system being carried out.
1907 *
1908 * Prepare all non-sysdev devices for system PM transition and execute "suspend"
1909 * callbacks for them.
1910 */
1911int dpm_suspend_start(pm_message_t state)
1912{
1913 ktime_t starttime = ktime_get();
1914 int error;
1915
1916 error = dpm_prepare(state);
1917 if (error)
1918 dpm_save_failed_step(SUSPEND_PREPARE);
1919 else
1920 error = dpm_suspend(state);
1921
1922 dpm_show_time(starttime, state, error, "start");
1923 return error;
1924}
1925EXPORT_SYMBOL_GPL(dpm_suspend_start);
1926
1927void __suspend_report_result(const char *function, struct device *dev, void *fn, int ret)
1928{
1929 if (ret)
1930 dev_err(dev, "%s(): %pS returns %d\n", function, fn, ret);
1931}
1932EXPORT_SYMBOL_GPL(__suspend_report_result);
1933
1934/**
1935 * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
1936 * @subordinate: Device that needs to wait for @dev.
1937 * @dev: Device to wait for.
1938 */
1939int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
1940{
1941 dpm_wait(dev, subordinate->power.async_suspend);
1942 return async_error;
1943}
1944EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);
1945
1946/**
1947 * dpm_for_each_dev - device iterator.
1948 * @data: data for the callback.
1949 * @fn: function to be called for each device.
1950 *
1951 * Iterate over devices in dpm_list, and call @fn for each device,
1952 * passing it @data.
1953 */
1954void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *))
1955{
1956 struct device *dev;
1957
1958 if (!fn)
1959 return;
1960
1961 device_pm_lock();
1962 list_for_each_entry(dev, &dpm_list, power.entry)
1963 fn(dev, data);
1964 device_pm_unlock();
1965}
1966EXPORT_SYMBOL_GPL(dpm_for_each_dev);
1967
1968static bool pm_ops_is_empty(const struct dev_pm_ops *ops)
1969{
1970 if (!ops)
1971 return true;
1972
1973 return !ops->prepare &&
1974 !ops->suspend &&
1975 !ops->suspend_late &&
1976 !ops->suspend_noirq &&
1977 !ops->resume_noirq &&
1978 !ops->resume_early &&
1979 !ops->resume &&
1980 !ops->complete;
1981}
1982
1983void device_pm_check_callbacks(struct device *dev)
1984{
1985 unsigned long flags;
1986
1987 spin_lock_irqsave(&dev->power.lock, flags);
1988 dev->power.no_pm_callbacks =
1989 (!dev->bus || (pm_ops_is_empty(dev->bus->pm) &&
1990 !dev->bus->suspend && !dev->bus->resume)) &&
1991 (!dev->class || pm_ops_is_empty(dev->class->pm)) &&
1992 (!dev->type || pm_ops_is_empty(dev->type->pm)) &&
1993 (!dev->pm_domain || pm_ops_is_empty(&dev->pm_domain->ops)) &&
1994 (!dev->driver || (pm_ops_is_empty(dev->driver->pm) &&
1995 !dev->driver->suspend && !dev->driver->resume));
1996 spin_unlock_irqrestore(&dev->power.lock, flags);
1997}
1998
1999bool dev_pm_skip_suspend(struct device *dev)
2000{
2001 return dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) &&
2002 pm_runtime_status_suspended(dev);
2003}