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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
20#include <linux/device.h>
21#include <linux/export.h>
22#include <linux/mutex.h>
23#include <linux/pm.h>
24#include <linux/pm_runtime.h>
25#include <linux/pm-trace.h>
26#include <linux/pm_wakeirq.h>
27#include <linux/interrupt.h>
28#include <linux/sched.h>
29#include <linux/sched/debug.h>
30#include <linux/async.h>
31#include <linux/suspend.h>
32#include <trace/events/power.h>
33#include <linux/cpufreq.h>
34#include <linux/cpuidle.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/*
44 * The entries in the dpm_list list are in a depth first order, simply
45 * because children are guaranteed to be discovered after parents, and
46 * are inserted at the back of the list on discovery.
47 *
48 * Since device_pm_add() may be called with a device lock held,
49 * we must never try to acquire a device lock while holding
50 * dpm_list_mutex.
51 */
52
53LIST_HEAD(dpm_list);
54static LIST_HEAD(dpm_prepared_list);
55static LIST_HEAD(dpm_suspended_list);
56static LIST_HEAD(dpm_late_early_list);
57static LIST_HEAD(dpm_noirq_list);
58
59struct suspend_stats suspend_stats;
60static DEFINE_MUTEX(dpm_list_mtx);
61static pm_message_t pm_transition;
62
63static int async_error;
64
65static const char *pm_verb(int event)
66{
67 switch (event) {
68 case PM_EVENT_SUSPEND:
69 return "suspend";
70 case PM_EVENT_RESUME:
71 return "resume";
72 case PM_EVENT_FREEZE:
73 return "freeze";
74 case PM_EVENT_QUIESCE:
75 return "quiesce";
76 case PM_EVENT_HIBERNATE:
77 return "hibernate";
78 case PM_EVENT_THAW:
79 return "thaw";
80 case PM_EVENT_RESTORE:
81 return "restore";
82 case PM_EVENT_RECOVER:
83 return "recover";
84 default:
85 return "(unknown PM event)";
86 }
87}
88
89/**
90 * device_pm_sleep_init - Initialize system suspend-related device fields.
91 * @dev: Device object being initialized.
92 */
93void device_pm_sleep_init(struct device *dev)
94{
95 dev->power.is_prepared = false;
96 dev->power.is_suspended = false;
97 dev->power.is_noirq_suspended = false;
98 dev->power.is_late_suspended = false;
99 init_completion(&dev->power.completion);
100 complete_all(&dev->power.completion);
101 dev->power.wakeup = NULL;
102 INIT_LIST_HEAD(&dev->power.entry);
103}
104
105/**
106 * device_pm_lock - Lock the list of active devices used by the PM core.
107 */
108void device_pm_lock(void)
109{
110 mutex_lock(&dpm_list_mtx);
111}
112
113/**
114 * device_pm_unlock - Unlock the list of active devices used by the PM core.
115 */
116void device_pm_unlock(void)
117{
118 mutex_unlock(&dpm_list_mtx);
119}
120
121/**
122 * device_pm_add - Add a device to the PM core's list of active devices.
123 * @dev: Device to add to the list.
124 */
125void device_pm_add(struct device *dev)
126{
127 /* Skip PM setup/initialization. */
128 if (device_pm_not_required(dev))
129 return;
130
131 pr_debug("Adding info for %s:%s\n",
132 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
133 device_pm_check_callbacks(dev);
134 mutex_lock(&dpm_list_mtx);
135 if (dev->parent && dev->parent->power.is_prepared)
136 dev_warn(dev, "parent %s should not be sleeping\n",
137 dev_name(dev->parent));
138 list_add_tail(&dev->power.entry, &dpm_list);
139 dev->power.in_dpm_list = true;
140 mutex_unlock(&dpm_list_mtx);
141}
142
143/**
144 * device_pm_remove - Remove a device from the PM core's list of active devices.
145 * @dev: Device to be removed from the list.
146 */
147void device_pm_remove(struct device *dev)
148{
149 if (device_pm_not_required(dev))
150 return;
151
152 pr_debug("Removing info for %s:%s\n",
153 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
154 complete_all(&dev->power.completion);
155 mutex_lock(&dpm_list_mtx);
156 list_del_init(&dev->power.entry);
157 dev->power.in_dpm_list = false;
158 mutex_unlock(&dpm_list_mtx);
159 device_wakeup_disable(dev);
160 pm_runtime_remove(dev);
161 device_pm_check_callbacks(dev);
162}
163
164/**
165 * device_pm_move_before - Move device in the PM core's list of active devices.
166 * @deva: Device to move in dpm_list.
167 * @devb: Device @deva should come before.
168 */
169void device_pm_move_before(struct device *deva, struct device *devb)
170{
171 pr_debug("Moving %s:%s before %s:%s\n",
172 deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
173 devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
174 /* Delete deva from dpm_list and reinsert before devb. */
175 list_move_tail(&deva->power.entry, &devb->power.entry);
176}
177
178/**
179 * device_pm_move_after - Move device in the PM core's list of active devices.
180 * @deva: Device to move in dpm_list.
181 * @devb: Device @deva should come after.
182 */
183void device_pm_move_after(struct device *deva, struct device *devb)
184{
185 pr_debug("Moving %s:%s after %s:%s\n",
186 deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
187 devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
188 /* Delete deva from dpm_list and reinsert after devb. */
189 list_move(&deva->power.entry, &devb->power.entry);
190}
191
192/**
193 * device_pm_move_last - Move device to end of the PM core's list of devices.
194 * @dev: Device to move in dpm_list.
195 */
196void device_pm_move_last(struct device *dev)
197{
198 pr_debug("Moving %s:%s to end of list\n",
199 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
200 list_move_tail(&dev->power.entry, &dpm_list);
201}
202
203static ktime_t initcall_debug_start(struct device *dev, void *cb)
204{
205 if (!pm_print_times_enabled)
206 return 0;
207
208 dev_info(dev, "calling %pS @ %i, parent: %s\n", cb,
209 task_pid_nr(current),
210 dev->parent ? dev_name(dev->parent) : "none");
211 return ktime_get();
212}
213
214static void initcall_debug_report(struct device *dev, ktime_t calltime,
215 void *cb, int error)
216{
217 ktime_t rettime;
218 s64 nsecs;
219
220 if (!pm_print_times_enabled)
221 return;
222
223 rettime = ktime_get();
224 nsecs = (s64) ktime_to_ns(ktime_sub(rettime, calltime));
225
226 dev_info(dev, "%pS returned %d after %Ld usecs\n", cb, error,
227 (unsigned long long)nsecs >> 10);
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(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 void dpm_wait_for_superior(struct device *dev, bool async)
277{
278 dpm_wait(dev->parent, async);
279 dpm_wait_for_suppliers(dev, async);
280}
281
282static void dpm_wait_for_consumers(struct device *dev, bool async)
283{
284 struct device_link *link;
285 int idx;
286
287 idx = device_links_read_lock();
288
289 /*
290 * The status of a device link can only be changed from "dormant" by a
291 * probe, but that cannot happen during system suspend/resume. In
292 * theory it can change to "dormant" at that time, but then it is
293 * reasonable to wait for the target device anyway (eg. if it goes
294 * away, it's better to wait for it to go away completely and then
295 * continue instead of trying to continue in parallel with its
296 * unregistration).
297 */
298 list_for_each_entry_rcu(link, &dev->links.consumers, s_node)
299 if (READ_ONCE(link->status) != DL_STATE_DORMANT)
300 dpm_wait(link->consumer, async);
301
302 device_links_read_unlock(idx);
303}
304
305static void dpm_wait_for_subordinate(struct device *dev, bool async)
306{
307 dpm_wait_for_children(dev, async);
308 dpm_wait_for_consumers(dev, async);
309}
310
311/**
312 * pm_op - Return the PM operation appropriate for given PM event.
313 * @ops: PM operations to choose from.
314 * @state: PM transition of the system being carried out.
315 */
316static pm_callback_t pm_op(const struct dev_pm_ops *ops, pm_message_t state)
317{
318 switch (state.event) {
319#ifdef CONFIG_SUSPEND
320 case PM_EVENT_SUSPEND:
321 return ops->suspend;
322 case PM_EVENT_RESUME:
323 return ops->resume;
324#endif /* CONFIG_SUSPEND */
325#ifdef CONFIG_HIBERNATE_CALLBACKS
326 case PM_EVENT_FREEZE:
327 case PM_EVENT_QUIESCE:
328 return ops->freeze;
329 case PM_EVENT_HIBERNATE:
330 return ops->poweroff;
331 case PM_EVENT_THAW:
332 case PM_EVENT_RECOVER:
333 return ops->thaw;
334 break;
335 case PM_EVENT_RESTORE:
336 return ops->restore;
337#endif /* CONFIG_HIBERNATE_CALLBACKS */
338 }
339
340 return NULL;
341}
342
343/**
344 * pm_late_early_op - Return the PM operation appropriate for given PM event.
345 * @ops: PM operations to choose from.
346 * @state: PM transition of the system being carried out.
347 *
348 * Runtime PM is disabled for @dev while this function is being executed.
349 */
350static pm_callback_t pm_late_early_op(const struct dev_pm_ops *ops,
351 pm_message_t state)
352{
353 switch (state.event) {
354#ifdef CONFIG_SUSPEND
355 case PM_EVENT_SUSPEND:
356 return ops->suspend_late;
357 case PM_EVENT_RESUME:
358 return ops->resume_early;
359#endif /* CONFIG_SUSPEND */
360#ifdef CONFIG_HIBERNATE_CALLBACKS
361 case PM_EVENT_FREEZE:
362 case PM_EVENT_QUIESCE:
363 return ops->freeze_late;
364 case PM_EVENT_HIBERNATE:
365 return ops->poweroff_late;
366 case PM_EVENT_THAW:
367 case PM_EVENT_RECOVER:
368 return ops->thaw_early;
369 case PM_EVENT_RESTORE:
370 return ops->restore_early;
371#endif /* CONFIG_HIBERNATE_CALLBACKS */
372 }
373
374 return NULL;
375}
376
377/**
378 * pm_noirq_op - Return the PM operation appropriate for given PM event.
379 * @ops: PM operations to choose from.
380 * @state: PM transition of the system being carried out.
381 *
382 * The driver of @dev will not receive interrupts while this function is being
383 * executed.
384 */
385static pm_callback_t pm_noirq_op(const struct dev_pm_ops *ops, pm_message_t state)
386{
387 switch (state.event) {
388#ifdef CONFIG_SUSPEND
389 case PM_EVENT_SUSPEND:
390 return ops->suspend_noirq;
391 case PM_EVENT_RESUME:
392 return ops->resume_noirq;
393#endif /* CONFIG_SUSPEND */
394#ifdef CONFIG_HIBERNATE_CALLBACKS
395 case PM_EVENT_FREEZE:
396 case PM_EVENT_QUIESCE:
397 return ops->freeze_noirq;
398 case PM_EVENT_HIBERNATE:
399 return ops->poweroff_noirq;
400 case PM_EVENT_THAW:
401 case PM_EVENT_RECOVER:
402 return ops->thaw_noirq;
403 case PM_EVENT_RESTORE:
404 return ops->restore_noirq;
405#endif /* CONFIG_HIBERNATE_CALLBACKS */
406 }
407
408 return NULL;
409}
410
411static void pm_dev_dbg(struct device *dev, pm_message_t state, const char *info)
412{
413 dev_dbg(dev, "%s%s%s\n", info, pm_verb(state.event),
414 ((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
415 ", may wakeup" : "");
416}
417
418static void pm_dev_err(struct device *dev, pm_message_t state, const char *info,
419 int error)
420{
421 pr_err("Device %s failed to %s%s: error %d\n",
422 dev_name(dev), pm_verb(state.event), info, error);
423}
424
425static void dpm_show_time(ktime_t starttime, pm_message_t state, int error,
426 const char *info)
427{
428 ktime_t calltime;
429 u64 usecs64;
430 int usecs;
431
432 calltime = ktime_get();
433 usecs64 = ktime_to_ns(ktime_sub(calltime, starttime));
434 do_div(usecs64, NSEC_PER_USEC);
435 usecs = usecs64;
436 if (usecs == 0)
437 usecs = 1;
438
439 pm_pr_dbg("%s%s%s of devices %s after %ld.%03ld msecs\n",
440 info ?: "", info ? " " : "", pm_verb(state.event),
441 error ? "aborted" : "complete",
442 usecs / USEC_PER_MSEC, usecs % USEC_PER_MSEC);
443}
444
445static int dpm_run_callback(pm_callback_t cb, struct device *dev,
446 pm_message_t state, const char *info)
447{
448 ktime_t calltime;
449 int error;
450
451 if (!cb)
452 return 0;
453
454 calltime = initcall_debug_start(dev, cb);
455
456 pm_dev_dbg(dev, state, info);
457 trace_device_pm_callback_start(dev, info, state.event);
458 error = cb(dev);
459 trace_device_pm_callback_end(dev, error);
460 suspend_report_result(cb, error);
461
462 initcall_debug_report(dev, calltime, cb, error);
463
464 return error;
465}
466
467#ifdef CONFIG_DPM_WATCHDOG
468struct dpm_watchdog {
469 struct device *dev;
470 struct task_struct *tsk;
471 struct timer_list timer;
472};
473
474#define DECLARE_DPM_WATCHDOG_ON_STACK(wd) \
475 struct dpm_watchdog wd
476
477/**
478 * dpm_watchdog_handler - Driver suspend / resume watchdog handler.
479 * @t: The timer that PM watchdog depends on.
480 *
481 * Called when a driver has timed out suspending or resuming.
482 * There's not much we can do here to recover so panic() to
483 * capture a crash-dump in pstore.
484 */
485static void dpm_watchdog_handler(struct timer_list *t)
486{
487 struct dpm_watchdog *wd = from_timer(wd, t, timer);
488
489 dev_emerg(wd->dev, "**** DPM device timeout ****\n");
490 show_stack(wd->tsk, NULL);
491 panic("%s %s: unrecoverable failure\n",
492 dev_driver_string(wd->dev), dev_name(wd->dev));
493}
494
495/**
496 * dpm_watchdog_set - Enable pm watchdog for given device.
497 * @wd: Watchdog. Must be allocated on the stack.
498 * @dev: Device to handle.
499 */
500static void dpm_watchdog_set(struct dpm_watchdog *wd, struct device *dev)
501{
502 struct timer_list *timer = &wd->timer;
503
504 wd->dev = dev;
505 wd->tsk = current;
506
507 timer_setup_on_stack(timer, dpm_watchdog_handler, 0);
508 /* use same timeout value for both suspend and resume */
509 timer->expires = jiffies + HZ * CONFIG_DPM_WATCHDOG_TIMEOUT;
510 add_timer(timer);
511}
512
513/**
514 * dpm_watchdog_clear - Disable suspend/resume watchdog.
515 * @wd: Watchdog to disable.
516 */
517static void dpm_watchdog_clear(struct dpm_watchdog *wd)
518{
519 struct timer_list *timer = &wd->timer;
520
521 del_timer_sync(timer);
522 destroy_timer_on_stack(timer);
523}
524#else
525#define DECLARE_DPM_WATCHDOG_ON_STACK(wd)
526#define dpm_watchdog_set(x, y)
527#define dpm_watchdog_clear(x)
528#endif
529
530/*------------------------- Resume routines -------------------------*/
531
532/**
533 * suspend_event - Return a "suspend" message for given "resume" one.
534 * @resume_msg: PM message representing a system-wide resume transition.
535 */
536static pm_message_t suspend_event(pm_message_t resume_msg)
537{
538 switch (resume_msg.event) {
539 case PM_EVENT_RESUME:
540 return PMSG_SUSPEND;
541 case PM_EVENT_THAW:
542 case PM_EVENT_RESTORE:
543 return PMSG_FREEZE;
544 case PM_EVENT_RECOVER:
545 return PMSG_HIBERNATE;
546 }
547 return PMSG_ON;
548}
549
550/**
551 * dev_pm_may_skip_resume - System-wide device resume optimization check.
552 * @dev: Target device.
553 *
554 * Checks whether or not the device may be left in suspend after a system-wide
555 * transition to the working state.
556 */
557bool dev_pm_may_skip_resume(struct device *dev)
558{
559 return !dev->power.must_resume && pm_transition.event != PM_EVENT_RESTORE;
560}
561
562static pm_callback_t dpm_subsys_resume_noirq_cb(struct device *dev,
563 pm_message_t state,
564 const char **info_p)
565{
566 pm_callback_t callback;
567 const char *info;
568
569 if (dev->pm_domain) {
570 info = "noirq power domain ";
571 callback = pm_noirq_op(&dev->pm_domain->ops, state);
572 } else if (dev->type && dev->type->pm) {
573 info = "noirq type ";
574 callback = pm_noirq_op(dev->type->pm, state);
575 } else if (dev->class && dev->class->pm) {
576 info = "noirq class ";
577 callback = pm_noirq_op(dev->class->pm, state);
578 } else if (dev->bus && dev->bus->pm) {
579 info = "noirq bus ";
580 callback = pm_noirq_op(dev->bus->pm, state);
581 } else {
582 return NULL;
583 }
584
585 if (info_p)
586 *info_p = info;
587
588 return callback;
589}
590
591static pm_callback_t dpm_subsys_suspend_noirq_cb(struct device *dev,
592 pm_message_t state,
593 const char **info_p);
594
595static pm_callback_t dpm_subsys_suspend_late_cb(struct device *dev,
596 pm_message_t state,
597 const char **info_p);
598
599/**
600 * device_resume_noirq - Execute a "noirq resume" callback for given device.
601 * @dev: Device to handle.
602 * @state: PM transition of the system being carried out.
603 * @async: If true, the device is being resumed asynchronously.
604 *
605 * The driver of @dev will not receive interrupts while this function is being
606 * executed.
607 */
608static int device_resume_noirq(struct device *dev, pm_message_t state, bool async)
609{
610 pm_callback_t callback;
611 const char *info;
612 bool skip_resume;
613 int error = 0;
614
615 TRACE_DEVICE(dev);
616 TRACE_RESUME(0);
617
618 if (dev->power.syscore || dev->power.direct_complete)
619 goto Out;
620
621 if (!dev->power.is_noirq_suspended)
622 goto Out;
623
624 dpm_wait_for_superior(dev, async);
625
626 skip_resume = dev_pm_may_skip_resume(dev);
627
628 callback = dpm_subsys_resume_noirq_cb(dev, state, &info);
629 if (callback)
630 goto Run;
631
632 if (skip_resume)
633 goto Skip;
634
635 if (dev_pm_smart_suspend_and_suspended(dev)) {
636 pm_message_t suspend_msg = suspend_event(state);
637
638 /*
639 * If "freeze" callbacks have been skipped during a transition
640 * related to hibernation, the subsequent "thaw" callbacks must
641 * be skipped too or bad things may happen. Otherwise, resume
642 * callbacks are going to be run for the device, so its runtime
643 * PM status must be changed to reflect the new state after the
644 * transition under way.
645 */
646 if (!dpm_subsys_suspend_late_cb(dev, suspend_msg, NULL) &&
647 !dpm_subsys_suspend_noirq_cb(dev, suspend_msg, NULL)) {
648 if (state.event == PM_EVENT_THAW) {
649 skip_resume = true;
650 goto Skip;
651 } else {
652 pm_runtime_set_active(dev);
653 }
654 }
655 }
656
657 if (dev->driver && dev->driver->pm) {
658 info = "noirq driver ";
659 callback = pm_noirq_op(dev->driver->pm, state);
660 }
661
662Run:
663 error = dpm_run_callback(callback, dev, state, info);
664
665Skip:
666 dev->power.is_noirq_suspended = false;
667
668 if (skip_resume) {
669 /* Make the next phases of resume skip the device. */
670 dev->power.is_late_suspended = false;
671 dev->power.is_suspended = false;
672 /*
673 * The device is going to be left in suspend, but it might not
674 * have been in runtime suspend before the system suspended, so
675 * its runtime PM status needs to be updated to avoid confusing
676 * the runtime PM framework when runtime PM is enabled for the
677 * device again.
678 */
679 pm_runtime_set_suspended(dev);
680 }
681
682Out:
683 complete_all(&dev->power.completion);
684 TRACE_RESUME(error);
685 return error;
686}
687
688static bool is_async(struct device *dev)
689{
690 return dev->power.async_suspend && pm_async_enabled
691 && !pm_trace_is_enabled();
692}
693
694static bool dpm_async_fn(struct device *dev, async_func_t func)
695{
696 reinit_completion(&dev->power.completion);
697
698 if (is_async(dev)) {
699 get_device(dev);
700 async_schedule(func, dev);
701 return true;
702 }
703
704 return false;
705}
706
707static void async_resume_noirq(void *data, async_cookie_t cookie)
708{
709 struct device *dev = (struct device *)data;
710 int error;
711
712 error = device_resume_noirq(dev, pm_transition, true);
713 if (error)
714 pm_dev_err(dev, pm_transition, " async", error);
715
716 put_device(dev);
717}
718
719static void dpm_noirq_resume_devices(pm_message_t state)
720{
721 struct device *dev;
722 ktime_t starttime = ktime_get();
723
724 trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, true);
725 mutex_lock(&dpm_list_mtx);
726 pm_transition = state;
727
728 /*
729 * Advanced the async threads upfront,
730 * in case the starting of async threads is
731 * delayed by non-async resuming devices.
732 */
733 list_for_each_entry(dev, &dpm_noirq_list, power.entry)
734 dpm_async_fn(dev, async_resume_noirq);
735
736 while (!list_empty(&dpm_noirq_list)) {
737 dev = to_device(dpm_noirq_list.next);
738 get_device(dev);
739 list_move_tail(&dev->power.entry, &dpm_late_early_list);
740 mutex_unlock(&dpm_list_mtx);
741
742 if (!is_async(dev)) {
743 int error;
744
745 error = device_resume_noirq(dev, state, false);
746 if (error) {
747 suspend_stats.failed_resume_noirq++;
748 dpm_save_failed_step(SUSPEND_RESUME_NOIRQ);
749 dpm_save_failed_dev(dev_name(dev));
750 pm_dev_err(dev, state, " noirq", error);
751 }
752 }
753
754 mutex_lock(&dpm_list_mtx);
755 put_device(dev);
756 }
757 mutex_unlock(&dpm_list_mtx);
758 async_synchronize_full();
759 dpm_show_time(starttime, state, 0, "noirq");
760 trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, false);
761}
762
763/**
764 * dpm_resume_noirq - Execute "noirq resume" callbacks for all devices.
765 * @state: PM transition of the system being carried out.
766 *
767 * Invoke the "noirq" resume callbacks for all devices in dpm_noirq_list and
768 * allow device drivers' interrupt handlers to be called.
769 */
770void dpm_resume_noirq(pm_message_t state)
771{
772 dpm_noirq_resume_devices(state);
773
774 resume_device_irqs();
775 device_wakeup_disarm_wake_irqs();
776
777 cpuidle_resume();
778}
779
780static pm_callback_t dpm_subsys_resume_early_cb(struct device *dev,
781 pm_message_t state,
782 const char **info_p)
783{
784 pm_callback_t callback;
785 const char *info;
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 } else {
800 return NULL;
801 }
802
803 if (info_p)
804 *info_p = info;
805
806 return callback;
807}
808
809/**
810 * device_resume_early - Execute an "early resume" callback for given device.
811 * @dev: Device to handle.
812 * @state: PM transition of the system being carried out.
813 * @async: If true, the device is being resumed asynchronously.
814 *
815 * Runtime PM is disabled for @dev while this function is being executed.
816 */
817static int device_resume_early(struct device *dev, pm_message_t state, bool async)
818{
819 pm_callback_t callback;
820 const char *info;
821 int error = 0;
822
823 TRACE_DEVICE(dev);
824 TRACE_RESUME(0);
825
826 if (dev->power.syscore || dev->power.direct_complete)
827 goto Out;
828
829 if (!dev->power.is_late_suspended)
830 goto Out;
831
832 dpm_wait_for_superior(dev, async);
833
834 callback = dpm_subsys_resume_early_cb(dev, state, &info);
835
836 if (!callback && dev->driver && dev->driver->pm) {
837 info = "early driver ";
838 callback = pm_late_early_op(dev->driver->pm, state);
839 }
840
841 error = dpm_run_callback(callback, dev, state, info);
842 dev->power.is_late_suspended = false;
843
844 Out:
845 TRACE_RESUME(error);
846
847 pm_runtime_enable(dev);
848 complete_all(&dev->power.completion);
849 return error;
850}
851
852static void async_resume_early(void *data, async_cookie_t cookie)
853{
854 struct device *dev = (struct device *)data;
855 int error;
856
857 error = device_resume_early(dev, pm_transition, true);
858 if (error)
859 pm_dev_err(dev, pm_transition, " async", error);
860
861 put_device(dev);
862}
863
864/**
865 * dpm_resume_early - Execute "early resume" callbacks for all devices.
866 * @state: PM transition of the system being carried out.
867 */
868void dpm_resume_early(pm_message_t state)
869{
870 struct device *dev;
871 ktime_t starttime = ktime_get();
872
873 trace_suspend_resume(TPS("dpm_resume_early"), state.event, true);
874 mutex_lock(&dpm_list_mtx);
875 pm_transition = state;
876
877 /*
878 * Advanced the async threads upfront,
879 * in case the starting of async threads is
880 * delayed by non-async resuming devices.
881 */
882 list_for_each_entry(dev, &dpm_late_early_list, power.entry)
883 dpm_async_fn(dev, async_resume_early);
884
885 while (!list_empty(&dpm_late_early_list)) {
886 dev = to_device(dpm_late_early_list.next);
887 get_device(dev);
888 list_move_tail(&dev->power.entry, &dpm_suspended_list);
889 mutex_unlock(&dpm_list_mtx);
890
891 if (!is_async(dev)) {
892 int error;
893
894 error = device_resume_early(dev, state, false);
895 if (error) {
896 suspend_stats.failed_resume_early++;
897 dpm_save_failed_step(SUSPEND_RESUME_EARLY);
898 dpm_save_failed_dev(dev_name(dev));
899 pm_dev_err(dev, state, " early", error);
900 }
901 }
902 mutex_lock(&dpm_list_mtx);
903 put_device(dev);
904 }
905 mutex_unlock(&dpm_list_mtx);
906 async_synchronize_full();
907 dpm_show_time(starttime, state, 0, "early");
908 trace_suspend_resume(TPS("dpm_resume_early"), state.event, false);
909}
910
911/**
912 * dpm_resume_start - Execute "noirq" and "early" device callbacks.
913 * @state: PM transition of the system being carried out.
914 */
915void dpm_resume_start(pm_message_t state)
916{
917 dpm_resume_noirq(state);
918 dpm_resume_early(state);
919}
920EXPORT_SYMBOL_GPL(dpm_resume_start);
921
922/**
923 * device_resume - Execute "resume" callbacks for given device.
924 * @dev: Device to handle.
925 * @state: PM transition of the system being carried out.
926 * @async: If true, the device is being resumed asynchronously.
927 */
928static int device_resume(struct device *dev, pm_message_t state, bool async)
929{
930 pm_callback_t callback = NULL;
931 const char *info = NULL;
932 int error = 0;
933 DECLARE_DPM_WATCHDOG_ON_STACK(wd);
934
935 TRACE_DEVICE(dev);
936 TRACE_RESUME(0);
937
938 if (dev->power.syscore)
939 goto Complete;
940
941 if (dev->power.direct_complete) {
942 /* Match the pm_runtime_disable() in __device_suspend(). */
943 pm_runtime_enable(dev);
944 goto Complete;
945 }
946
947 dpm_wait_for_superior(dev, async);
948 dpm_watchdog_set(&wd, dev);
949 device_lock(dev);
950
951 /*
952 * This is a fib. But we'll allow new children to be added below
953 * a resumed device, even if the device hasn't been completed yet.
954 */
955 dev->power.is_prepared = false;
956
957 if (!dev->power.is_suspended)
958 goto Unlock;
959
960 if (dev->pm_domain) {
961 info = "power domain ";
962 callback = pm_op(&dev->pm_domain->ops, state);
963 goto Driver;
964 }
965
966 if (dev->type && dev->type->pm) {
967 info = "type ";
968 callback = pm_op(dev->type->pm, state);
969 goto Driver;
970 }
971
972 if (dev->class && dev->class->pm) {
973 info = "class ";
974 callback = pm_op(dev->class->pm, state);
975 goto Driver;
976 }
977
978 if (dev->bus) {
979 if (dev->bus->pm) {
980 info = "bus ";
981 callback = pm_op(dev->bus->pm, state);
982 } else if (dev->bus->resume) {
983 info = "legacy bus ";
984 callback = dev->bus->resume;
985 goto End;
986 }
987 }
988
989 Driver:
990 if (!callback && dev->driver && dev->driver->pm) {
991 info = "driver ";
992 callback = pm_op(dev->driver->pm, state);
993 }
994
995 End:
996 error = dpm_run_callback(callback, dev, state, info);
997 dev->power.is_suspended = false;
998
999 Unlock:
1000 device_unlock(dev);
1001 dpm_watchdog_clear(&wd);
1002
1003 Complete:
1004 complete_all(&dev->power.completion);
1005
1006 TRACE_RESUME(error);
1007
1008 return error;
1009}
1010
1011static void async_resume(void *data, async_cookie_t cookie)
1012{
1013 struct device *dev = (struct device *)data;
1014 int error;
1015
1016 error = device_resume(dev, pm_transition, true);
1017 if (error)
1018 pm_dev_err(dev, pm_transition, " async", error);
1019 put_device(dev);
1020}
1021
1022/**
1023 * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
1024 * @state: PM transition of the system being carried out.
1025 *
1026 * Execute the appropriate "resume" callback for all devices whose status
1027 * indicates that they are suspended.
1028 */
1029void dpm_resume(pm_message_t state)
1030{
1031 struct device *dev;
1032 ktime_t starttime = ktime_get();
1033
1034 trace_suspend_resume(TPS("dpm_resume"), state.event, true);
1035 might_sleep();
1036
1037 mutex_lock(&dpm_list_mtx);
1038 pm_transition = state;
1039 async_error = 0;
1040
1041 list_for_each_entry(dev, &dpm_suspended_list, power.entry)
1042 dpm_async_fn(dev, async_resume);
1043
1044 while (!list_empty(&dpm_suspended_list)) {
1045 dev = to_device(dpm_suspended_list.next);
1046 get_device(dev);
1047 if (!is_async(dev)) {
1048 int error;
1049
1050 mutex_unlock(&dpm_list_mtx);
1051
1052 error = device_resume(dev, state, false);
1053 if (error) {
1054 suspend_stats.failed_resume++;
1055 dpm_save_failed_step(SUSPEND_RESUME);
1056 dpm_save_failed_dev(dev_name(dev));
1057 pm_dev_err(dev, state, "", error);
1058 }
1059
1060 mutex_lock(&dpm_list_mtx);
1061 }
1062 if (!list_empty(&dev->power.entry))
1063 list_move_tail(&dev->power.entry, &dpm_prepared_list);
1064 put_device(dev);
1065 }
1066 mutex_unlock(&dpm_list_mtx);
1067 async_synchronize_full();
1068 dpm_show_time(starttime, state, 0, NULL);
1069
1070 cpufreq_resume();
1071 devfreq_resume();
1072 trace_suspend_resume(TPS("dpm_resume"), state.event, false);
1073}
1074
1075/**
1076 * device_complete - Complete a PM transition for given device.
1077 * @dev: Device to handle.
1078 * @state: PM transition of the system being carried out.
1079 */
1080static void device_complete(struct device *dev, pm_message_t state)
1081{
1082 void (*callback)(struct device *) = NULL;
1083 const char *info = NULL;
1084
1085 if (dev->power.syscore)
1086 return;
1087
1088 device_lock(dev);
1089
1090 if (dev->pm_domain) {
1091 info = "completing power domain ";
1092 callback = dev->pm_domain->ops.complete;
1093 } else if (dev->type && dev->type->pm) {
1094 info = "completing type ";
1095 callback = dev->type->pm->complete;
1096 } else if (dev->class && dev->class->pm) {
1097 info = "completing class ";
1098 callback = dev->class->pm->complete;
1099 } else if (dev->bus && dev->bus->pm) {
1100 info = "completing bus ";
1101 callback = dev->bus->pm->complete;
1102 }
1103
1104 if (!callback && dev->driver && dev->driver->pm) {
1105 info = "completing driver ";
1106 callback = dev->driver->pm->complete;
1107 }
1108
1109 if (callback) {
1110 pm_dev_dbg(dev, state, info);
1111 callback(dev);
1112 }
1113
1114 device_unlock(dev);
1115
1116 pm_runtime_put(dev);
1117}
1118
1119/**
1120 * dpm_complete - Complete a PM transition for all non-sysdev devices.
1121 * @state: PM transition of the system being carried out.
1122 *
1123 * Execute the ->complete() callbacks for all devices whose PM status is not
1124 * DPM_ON (this allows new devices to be registered).
1125 */
1126void dpm_complete(pm_message_t state)
1127{
1128 struct list_head list;
1129
1130 trace_suspend_resume(TPS("dpm_complete"), state.event, true);
1131 might_sleep();
1132
1133 INIT_LIST_HEAD(&list);
1134 mutex_lock(&dpm_list_mtx);
1135 while (!list_empty(&dpm_prepared_list)) {
1136 struct device *dev = to_device(dpm_prepared_list.prev);
1137
1138 get_device(dev);
1139 dev->power.is_prepared = false;
1140 list_move(&dev->power.entry, &list);
1141 mutex_unlock(&dpm_list_mtx);
1142
1143 trace_device_pm_callback_start(dev, "", state.event);
1144 device_complete(dev, state);
1145 trace_device_pm_callback_end(dev, 0);
1146
1147 mutex_lock(&dpm_list_mtx);
1148 put_device(dev);
1149 }
1150 list_splice(&list, &dpm_list);
1151 mutex_unlock(&dpm_list_mtx);
1152
1153 /* Allow device probing and trigger re-probing of deferred devices */
1154 device_unblock_probing();
1155 trace_suspend_resume(TPS("dpm_complete"), state.event, false);
1156}
1157
1158/**
1159 * dpm_resume_end - Execute "resume" callbacks and complete system transition.
1160 * @state: PM transition of the system being carried out.
1161 *
1162 * Execute "resume" callbacks for all devices and complete the PM transition of
1163 * the system.
1164 */
1165void dpm_resume_end(pm_message_t state)
1166{
1167 dpm_resume(state);
1168 dpm_complete(state);
1169}
1170EXPORT_SYMBOL_GPL(dpm_resume_end);
1171
1172
1173/*------------------------- Suspend routines -------------------------*/
1174
1175/**
1176 * resume_event - Return a "resume" message for given "suspend" sleep state.
1177 * @sleep_state: PM message representing a sleep state.
1178 *
1179 * Return a PM message representing the resume event corresponding to given
1180 * sleep state.
1181 */
1182static pm_message_t resume_event(pm_message_t sleep_state)
1183{
1184 switch (sleep_state.event) {
1185 case PM_EVENT_SUSPEND:
1186 return PMSG_RESUME;
1187 case PM_EVENT_FREEZE:
1188 case PM_EVENT_QUIESCE:
1189 return PMSG_RECOVER;
1190 case PM_EVENT_HIBERNATE:
1191 return PMSG_RESTORE;
1192 }
1193 return PMSG_ON;
1194}
1195
1196static void dpm_superior_set_must_resume(struct device *dev)
1197{
1198 struct device_link *link;
1199 int idx;
1200
1201 if (dev->parent)
1202 dev->parent->power.must_resume = true;
1203
1204 idx = device_links_read_lock();
1205
1206 list_for_each_entry_rcu(link, &dev->links.suppliers, c_node)
1207 link->supplier->power.must_resume = true;
1208
1209 device_links_read_unlock(idx);
1210}
1211
1212static pm_callback_t dpm_subsys_suspend_noirq_cb(struct device *dev,
1213 pm_message_t state,
1214 const char **info_p)
1215{
1216 pm_callback_t callback;
1217 const char *info;
1218
1219 if (dev->pm_domain) {
1220 info = "noirq power domain ";
1221 callback = pm_noirq_op(&dev->pm_domain->ops, state);
1222 } else if (dev->type && dev->type->pm) {
1223 info = "noirq type ";
1224 callback = pm_noirq_op(dev->type->pm, state);
1225 } else if (dev->class && dev->class->pm) {
1226 info = "noirq class ";
1227 callback = pm_noirq_op(dev->class->pm, state);
1228 } else if (dev->bus && dev->bus->pm) {
1229 info = "noirq bus ";
1230 callback = pm_noirq_op(dev->bus->pm, state);
1231 } else {
1232 return NULL;
1233 }
1234
1235 if (info_p)
1236 *info_p = info;
1237
1238 return callback;
1239}
1240
1241static bool device_must_resume(struct device *dev, pm_message_t state,
1242 bool no_subsys_suspend_noirq)
1243{
1244 pm_message_t resume_msg = resume_event(state);
1245
1246 /*
1247 * If all of the device driver's "noirq", "late" and "early" callbacks
1248 * are invoked directly by the core, the decision to allow the device to
1249 * stay in suspend can be based on its current runtime PM status and its
1250 * wakeup settings.
1251 */
1252 if (no_subsys_suspend_noirq &&
1253 !dpm_subsys_suspend_late_cb(dev, state, NULL) &&
1254 !dpm_subsys_resume_early_cb(dev, resume_msg, NULL) &&
1255 !dpm_subsys_resume_noirq_cb(dev, resume_msg, NULL))
1256 return !pm_runtime_status_suspended(dev) &&
1257 (resume_msg.event != PM_EVENT_RESUME ||
1258 (device_can_wakeup(dev) && !device_may_wakeup(dev)));
1259
1260 /*
1261 * The only safe strategy here is to require that if the device may not
1262 * be left in suspend, resume callbacks must be invoked for it.
1263 */
1264 return !dev->power.may_skip_resume;
1265}
1266
1267/**
1268 * __device_suspend_noirq - Execute a "noirq suspend" callback for given device.
1269 * @dev: Device to handle.
1270 * @state: PM transition of the system being carried out.
1271 * @async: If true, the device is being suspended asynchronously.
1272 *
1273 * The driver of @dev will not receive interrupts while this function is being
1274 * executed.
1275 */
1276static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool async)
1277{
1278 pm_callback_t callback;
1279 const char *info;
1280 bool no_subsys_cb = false;
1281 int error = 0;
1282
1283 TRACE_DEVICE(dev);
1284 TRACE_SUSPEND(0);
1285
1286 dpm_wait_for_subordinate(dev, async);
1287
1288 if (async_error)
1289 goto Complete;
1290
1291 if (dev->power.syscore || dev->power.direct_complete)
1292 goto Complete;
1293
1294 callback = dpm_subsys_suspend_noirq_cb(dev, state, &info);
1295 if (callback)
1296 goto Run;
1297
1298 no_subsys_cb = !dpm_subsys_suspend_late_cb(dev, state, NULL);
1299
1300 if (dev_pm_smart_suspend_and_suspended(dev) && no_subsys_cb)
1301 goto Skip;
1302
1303 if (dev->driver && dev->driver->pm) {
1304 info = "noirq driver ";
1305 callback = pm_noirq_op(dev->driver->pm, state);
1306 }
1307
1308Run:
1309 error = dpm_run_callback(callback, dev, state, info);
1310 if (error) {
1311 async_error = error;
1312 goto Complete;
1313 }
1314
1315Skip:
1316 dev->power.is_noirq_suspended = true;
1317
1318 if (dev_pm_test_driver_flags(dev, DPM_FLAG_LEAVE_SUSPENDED)) {
1319 dev->power.must_resume = dev->power.must_resume ||
1320 atomic_read(&dev->power.usage_count) > 1 ||
1321 device_must_resume(dev, state, no_subsys_cb);
1322 } else {
1323 dev->power.must_resume = true;
1324 }
1325
1326 if (dev->power.must_resume)
1327 dpm_superior_set_must_resume(dev);
1328
1329Complete:
1330 complete_all(&dev->power.completion);
1331 TRACE_SUSPEND(error);
1332 return error;
1333}
1334
1335static void async_suspend_noirq(void *data, async_cookie_t cookie)
1336{
1337 struct device *dev = (struct device *)data;
1338 int error;
1339
1340 error = __device_suspend_noirq(dev, pm_transition, true);
1341 if (error) {
1342 dpm_save_failed_dev(dev_name(dev));
1343 pm_dev_err(dev, pm_transition, " async", error);
1344 }
1345
1346 put_device(dev);
1347}
1348
1349static int device_suspend_noirq(struct device *dev)
1350{
1351 if (dpm_async_fn(dev, async_suspend_noirq))
1352 return 0;
1353
1354 return __device_suspend_noirq(dev, pm_transition, false);
1355}
1356
1357static int dpm_noirq_suspend_devices(pm_message_t state)
1358{
1359 ktime_t starttime = ktime_get();
1360 int error = 0;
1361
1362 trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, true);
1363 mutex_lock(&dpm_list_mtx);
1364 pm_transition = state;
1365 async_error = 0;
1366
1367 while (!list_empty(&dpm_late_early_list)) {
1368 struct device *dev = to_device(dpm_late_early_list.prev);
1369
1370 get_device(dev);
1371 mutex_unlock(&dpm_list_mtx);
1372
1373 error = device_suspend_noirq(dev);
1374
1375 mutex_lock(&dpm_list_mtx);
1376 if (error) {
1377 pm_dev_err(dev, state, " noirq", error);
1378 dpm_save_failed_dev(dev_name(dev));
1379 put_device(dev);
1380 break;
1381 }
1382 if (!list_empty(&dev->power.entry))
1383 list_move(&dev->power.entry, &dpm_noirq_list);
1384 put_device(dev);
1385
1386 if (async_error)
1387 break;
1388 }
1389 mutex_unlock(&dpm_list_mtx);
1390 async_synchronize_full();
1391 if (!error)
1392 error = async_error;
1393
1394 if (error) {
1395 suspend_stats.failed_suspend_noirq++;
1396 dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ);
1397 }
1398 dpm_show_time(starttime, state, error, "noirq");
1399 trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, false);
1400 return error;
1401}
1402
1403/**
1404 * dpm_suspend_noirq - Execute "noirq suspend" callbacks for all devices.
1405 * @state: PM transition of the system being carried out.
1406 *
1407 * Prevent device drivers' interrupt handlers from being called and invoke
1408 * "noirq" suspend callbacks for all non-sysdev devices.
1409 */
1410int dpm_suspend_noirq(pm_message_t state)
1411{
1412 int ret;
1413
1414 cpuidle_pause();
1415
1416 device_wakeup_arm_wake_irqs();
1417 suspend_device_irqs();
1418
1419 ret = dpm_noirq_suspend_devices(state);
1420 if (ret)
1421 dpm_resume_noirq(resume_event(state));
1422
1423 return ret;
1424}
1425
1426static void dpm_propagate_wakeup_to_parent(struct device *dev)
1427{
1428 struct device *parent = dev->parent;
1429
1430 if (!parent)
1431 return;
1432
1433 spin_lock_irq(&parent->power.lock);
1434
1435 if (dev->power.wakeup_path && !parent->power.ignore_children)
1436 parent->power.wakeup_path = true;
1437
1438 spin_unlock_irq(&parent->power.lock);
1439}
1440
1441static pm_callback_t dpm_subsys_suspend_late_cb(struct device *dev,
1442 pm_message_t state,
1443 const char **info_p)
1444{
1445 pm_callback_t callback;
1446 const char *info;
1447
1448 if (dev->pm_domain) {
1449 info = "late power domain ";
1450 callback = pm_late_early_op(&dev->pm_domain->ops, state);
1451 } else if (dev->type && dev->type->pm) {
1452 info = "late type ";
1453 callback = pm_late_early_op(dev->type->pm, state);
1454 } else if (dev->class && dev->class->pm) {
1455 info = "late class ";
1456 callback = pm_late_early_op(dev->class->pm, state);
1457 } else if (dev->bus && dev->bus->pm) {
1458 info = "late bus ";
1459 callback = pm_late_early_op(dev->bus->pm, state);
1460 } else {
1461 return NULL;
1462 }
1463
1464 if (info_p)
1465 *info_p = info;
1466
1467 return callback;
1468}
1469
1470/**
1471 * __device_suspend_late - Execute a "late suspend" callback for given device.
1472 * @dev: Device to handle.
1473 * @state: PM transition of the system being carried out.
1474 * @async: If true, the device is being suspended asynchronously.
1475 *
1476 * Runtime PM is disabled for @dev while this function is being executed.
1477 */
1478static int __device_suspend_late(struct device *dev, pm_message_t state, bool async)
1479{
1480 pm_callback_t callback;
1481 const char *info;
1482 int error = 0;
1483
1484 TRACE_DEVICE(dev);
1485 TRACE_SUSPEND(0);
1486
1487 __pm_runtime_disable(dev, false);
1488
1489 dpm_wait_for_subordinate(dev, async);
1490
1491 if (async_error)
1492 goto Complete;
1493
1494 if (pm_wakeup_pending()) {
1495 async_error = -EBUSY;
1496 goto Complete;
1497 }
1498
1499 if (dev->power.syscore || dev->power.direct_complete)
1500 goto Complete;
1501
1502 callback = dpm_subsys_suspend_late_cb(dev, state, &info);
1503 if (callback)
1504 goto Run;
1505
1506 if (dev_pm_smart_suspend_and_suspended(dev) &&
1507 !dpm_subsys_suspend_noirq_cb(dev, state, NULL))
1508 goto Skip;
1509
1510 if (dev->driver && dev->driver->pm) {
1511 info = "late driver ";
1512 callback = pm_late_early_op(dev->driver->pm, state);
1513 }
1514
1515Run:
1516 error = dpm_run_callback(callback, dev, state, info);
1517 if (error) {
1518 async_error = error;
1519 goto Complete;
1520 }
1521 dpm_propagate_wakeup_to_parent(dev);
1522
1523Skip:
1524 dev->power.is_late_suspended = true;
1525
1526Complete:
1527 TRACE_SUSPEND(error);
1528 complete_all(&dev->power.completion);
1529 return error;
1530}
1531
1532static void async_suspend_late(void *data, async_cookie_t cookie)
1533{
1534 struct device *dev = (struct device *)data;
1535 int error;
1536
1537 error = __device_suspend_late(dev, pm_transition, true);
1538 if (error) {
1539 dpm_save_failed_dev(dev_name(dev));
1540 pm_dev_err(dev, pm_transition, " async", error);
1541 }
1542 put_device(dev);
1543}
1544
1545static int device_suspend_late(struct device *dev)
1546{
1547 if (dpm_async_fn(dev, async_suspend_late))
1548 return 0;
1549
1550 return __device_suspend_late(dev, pm_transition, false);
1551}
1552
1553/**
1554 * dpm_suspend_late - Execute "late suspend" callbacks for all devices.
1555 * @state: PM transition of the system being carried out.
1556 */
1557int dpm_suspend_late(pm_message_t state)
1558{
1559 ktime_t starttime = ktime_get();
1560 int error = 0;
1561
1562 trace_suspend_resume(TPS("dpm_suspend_late"), state.event, true);
1563 mutex_lock(&dpm_list_mtx);
1564 pm_transition = state;
1565 async_error = 0;
1566
1567 while (!list_empty(&dpm_suspended_list)) {
1568 struct device *dev = to_device(dpm_suspended_list.prev);
1569
1570 get_device(dev);
1571 mutex_unlock(&dpm_list_mtx);
1572
1573 error = device_suspend_late(dev);
1574
1575 mutex_lock(&dpm_list_mtx);
1576 if (!list_empty(&dev->power.entry))
1577 list_move(&dev->power.entry, &dpm_late_early_list);
1578
1579 if (error) {
1580 pm_dev_err(dev, state, " late", error);
1581 dpm_save_failed_dev(dev_name(dev));
1582 put_device(dev);
1583 break;
1584 }
1585 put_device(dev);
1586
1587 if (async_error)
1588 break;
1589 }
1590 mutex_unlock(&dpm_list_mtx);
1591 async_synchronize_full();
1592 if (!error)
1593 error = async_error;
1594 if (error) {
1595 suspend_stats.failed_suspend_late++;
1596 dpm_save_failed_step(SUSPEND_SUSPEND_LATE);
1597 dpm_resume_early(resume_event(state));
1598 }
1599 dpm_show_time(starttime, state, error, "late");
1600 trace_suspend_resume(TPS("dpm_suspend_late"), state.event, false);
1601 return error;
1602}
1603
1604/**
1605 * dpm_suspend_end - Execute "late" and "noirq" device suspend callbacks.
1606 * @state: PM transition of the system being carried out.
1607 */
1608int dpm_suspend_end(pm_message_t state)
1609{
1610 ktime_t starttime = ktime_get();
1611 int error;
1612
1613 error = dpm_suspend_late(state);
1614 if (error)
1615 goto out;
1616
1617 error = dpm_suspend_noirq(state);
1618 if (error)
1619 dpm_resume_early(resume_event(state));
1620
1621out:
1622 dpm_show_time(starttime, state, error, "end");
1623 return error;
1624}
1625EXPORT_SYMBOL_GPL(dpm_suspend_end);
1626
1627/**
1628 * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
1629 * @dev: Device to suspend.
1630 * @state: PM transition of the system being carried out.
1631 * @cb: Suspend callback to execute.
1632 * @info: string description of caller.
1633 */
1634static int legacy_suspend(struct device *dev, pm_message_t state,
1635 int (*cb)(struct device *dev, pm_message_t state),
1636 const char *info)
1637{
1638 int error;
1639 ktime_t calltime;
1640
1641 calltime = initcall_debug_start(dev, cb);
1642
1643 trace_device_pm_callback_start(dev, info, state.event);
1644 error = cb(dev, state);
1645 trace_device_pm_callback_end(dev, error);
1646 suspend_report_result(cb, error);
1647
1648 initcall_debug_report(dev, calltime, cb, error);
1649
1650 return error;
1651}
1652
1653static void dpm_clear_superiors_direct_complete(struct device *dev)
1654{
1655 struct device_link *link;
1656 int idx;
1657
1658 if (dev->parent) {
1659 spin_lock_irq(&dev->parent->power.lock);
1660 dev->parent->power.direct_complete = false;
1661 spin_unlock_irq(&dev->parent->power.lock);
1662 }
1663
1664 idx = device_links_read_lock();
1665
1666 list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) {
1667 spin_lock_irq(&link->supplier->power.lock);
1668 link->supplier->power.direct_complete = false;
1669 spin_unlock_irq(&link->supplier->power.lock);
1670 }
1671
1672 device_links_read_unlock(idx);
1673}
1674
1675/**
1676 * __device_suspend - Execute "suspend" callbacks for given device.
1677 * @dev: Device to handle.
1678 * @state: PM transition of the system being carried out.
1679 * @async: If true, the device is being suspended asynchronously.
1680 */
1681static int __device_suspend(struct device *dev, pm_message_t state, bool async)
1682{
1683 pm_callback_t callback = NULL;
1684 const char *info = NULL;
1685 int error = 0;
1686 DECLARE_DPM_WATCHDOG_ON_STACK(wd);
1687
1688 TRACE_DEVICE(dev);
1689 TRACE_SUSPEND(0);
1690
1691 dpm_wait_for_subordinate(dev, async);
1692
1693 if (async_error) {
1694 dev->power.direct_complete = false;
1695 goto Complete;
1696 }
1697
1698 /*
1699 * If a device configured to wake up the system from sleep states
1700 * has been suspended at run time and there's a resume request pending
1701 * for it, this is equivalent to the device signaling wakeup, so the
1702 * system suspend operation should be aborted.
1703 */
1704 if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
1705 pm_wakeup_event(dev, 0);
1706
1707 if (pm_wakeup_pending()) {
1708 dev->power.direct_complete = false;
1709 async_error = -EBUSY;
1710 goto Complete;
1711 }
1712
1713 if (dev->power.syscore)
1714 goto Complete;
1715
1716 /* Avoid direct_complete to let wakeup_path propagate. */
1717 if (device_may_wakeup(dev) || dev->power.wakeup_path)
1718 dev->power.direct_complete = false;
1719
1720 if (dev->power.direct_complete) {
1721 if (pm_runtime_status_suspended(dev)) {
1722 pm_runtime_disable(dev);
1723 if (pm_runtime_status_suspended(dev)) {
1724 pm_dev_dbg(dev, state, "direct-complete ");
1725 goto Complete;
1726 }
1727
1728 pm_runtime_enable(dev);
1729 }
1730 dev->power.direct_complete = false;
1731 }
1732
1733 dev->power.may_skip_resume = false;
1734 dev->power.must_resume = false;
1735
1736 dpm_watchdog_set(&wd, dev);
1737 device_lock(dev);
1738
1739 if (dev->pm_domain) {
1740 info = "power domain ";
1741 callback = pm_op(&dev->pm_domain->ops, state);
1742 goto Run;
1743 }
1744
1745 if (dev->type && dev->type->pm) {
1746 info = "type ";
1747 callback = pm_op(dev->type->pm, state);
1748 goto Run;
1749 }
1750
1751 if (dev->class && dev->class->pm) {
1752 info = "class ";
1753 callback = pm_op(dev->class->pm, state);
1754 goto Run;
1755 }
1756
1757 if (dev->bus) {
1758 if (dev->bus->pm) {
1759 info = "bus ";
1760 callback = pm_op(dev->bus->pm, state);
1761 } else if (dev->bus->suspend) {
1762 pm_dev_dbg(dev, state, "legacy bus ");
1763 error = legacy_suspend(dev, state, dev->bus->suspend,
1764 "legacy bus ");
1765 goto End;
1766 }
1767 }
1768
1769 Run:
1770 if (!callback && dev->driver && dev->driver->pm) {
1771 info = "driver ";
1772 callback = pm_op(dev->driver->pm, state);
1773 }
1774
1775 error = dpm_run_callback(callback, dev, state, info);
1776
1777 End:
1778 if (!error) {
1779 dev->power.is_suspended = true;
1780 if (device_may_wakeup(dev))
1781 dev->power.wakeup_path = true;
1782
1783 dpm_propagate_wakeup_to_parent(dev);
1784 dpm_clear_superiors_direct_complete(dev);
1785 }
1786
1787 device_unlock(dev);
1788 dpm_watchdog_clear(&wd);
1789
1790 Complete:
1791 if (error)
1792 async_error = error;
1793
1794 complete_all(&dev->power.completion);
1795 TRACE_SUSPEND(error);
1796 return error;
1797}
1798
1799static void async_suspend(void *data, async_cookie_t cookie)
1800{
1801 struct device *dev = (struct device *)data;
1802 int error;
1803
1804 error = __device_suspend(dev, pm_transition, true);
1805 if (error) {
1806 dpm_save_failed_dev(dev_name(dev));
1807 pm_dev_err(dev, pm_transition, " async", error);
1808 }
1809
1810 put_device(dev);
1811}
1812
1813static int device_suspend(struct device *dev)
1814{
1815 if (dpm_async_fn(dev, async_suspend))
1816 return 0;
1817
1818 return __device_suspend(dev, pm_transition, false);
1819}
1820
1821/**
1822 * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
1823 * @state: PM transition of the system being carried out.
1824 */
1825int dpm_suspend(pm_message_t state)
1826{
1827 ktime_t starttime = ktime_get();
1828 int error = 0;
1829
1830 trace_suspend_resume(TPS("dpm_suspend"), state.event, true);
1831 might_sleep();
1832
1833 devfreq_suspend();
1834 cpufreq_suspend();
1835
1836 mutex_lock(&dpm_list_mtx);
1837 pm_transition = state;
1838 async_error = 0;
1839 while (!list_empty(&dpm_prepared_list)) {
1840 struct device *dev = to_device(dpm_prepared_list.prev);
1841
1842 get_device(dev);
1843 mutex_unlock(&dpm_list_mtx);
1844
1845 error = device_suspend(dev);
1846
1847 mutex_lock(&dpm_list_mtx);
1848 if (error) {
1849 pm_dev_err(dev, state, "", error);
1850 dpm_save_failed_dev(dev_name(dev));
1851 put_device(dev);
1852 break;
1853 }
1854 if (!list_empty(&dev->power.entry))
1855 list_move(&dev->power.entry, &dpm_suspended_list);
1856 put_device(dev);
1857 if (async_error)
1858 break;
1859 }
1860 mutex_unlock(&dpm_list_mtx);
1861 async_synchronize_full();
1862 if (!error)
1863 error = async_error;
1864 if (error) {
1865 suspend_stats.failed_suspend++;
1866 dpm_save_failed_step(SUSPEND_SUSPEND);
1867 }
1868 dpm_show_time(starttime, state, error, NULL);
1869 trace_suspend_resume(TPS("dpm_suspend"), state.event, false);
1870 return error;
1871}
1872
1873/**
1874 * device_prepare - Prepare a device for system power transition.
1875 * @dev: Device to handle.
1876 * @state: PM transition of the system being carried out.
1877 *
1878 * Execute the ->prepare() callback(s) for given device. No new children of the
1879 * device may be registered after this function has returned.
1880 */
1881static int device_prepare(struct device *dev, pm_message_t state)
1882{
1883 int (*callback)(struct device *) = NULL;
1884 int ret = 0;
1885
1886 if (dev->power.syscore)
1887 return 0;
1888
1889 WARN_ON(!pm_runtime_enabled(dev) &&
1890 dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND |
1891 DPM_FLAG_LEAVE_SUSPENDED));
1892
1893 /*
1894 * If a device's parent goes into runtime suspend at the wrong time,
1895 * it won't be possible to resume the device. To prevent this we
1896 * block runtime suspend here, during the prepare phase, and allow
1897 * it again during the complete phase.
1898 */
1899 pm_runtime_get_noresume(dev);
1900
1901 device_lock(dev);
1902
1903 dev->power.wakeup_path = false;
1904
1905 if (dev->power.no_pm_callbacks)
1906 goto unlock;
1907
1908 if (dev->pm_domain)
1909 callback = dev->pm_domain->ops.prepare;
1910 else if (dev->type && dev->type->pm)
1911 callback = dev->type->pm->prepare;
1912 else if (dev->class && dev->class->pm)
1913 callback = dev->class->pm->prepare;
1914 else if (dev->bus && dev->bus->pm)
1915 callback = dev->bus->pm->prepare;
1916
1917 if (!callback && dev->driver && dev->driver->pm)
1918 callback = dev->driver->pm->prepare;
1919
1920 if (callback)
1921 ret = callback(dev);
1922
1923unlock:
1924 device_unlock(dev);
1925
1926 if (ret < 0) {
1927 suspend_report_result(callback, ret);
1928 pm_runtime_put(dev);
1929 return ret;
1930 }
1931 /*
1932 * A positive return value from ->prepare() means "this device appears
1933 * to be runtime-suspended and its state is fine, so if it really is
1934 * runtime-suspended, you can leave it in that state provided that you
1935 * will do the same thing with all of its descendants". This only
1936 * applies to suspend transitions, however.
1937 */
1938 spin_lock_irq(&dev->power.lock);
1939 dev->power.direct_complete = state.event == PM_EVENT_SUSPEND &&
1940 ((pm_runtime_suspended(dev) && ret > 0) ||
1941 dev->power.no_pm_callbacks) &&
1942 !dev_pm_test_driver_flags(dev, DPM_FLAG_NEVER_SKIP);
1943 spin_unlock_irq(&dev->power.lock);
1944 return 0;
1945}
1946
1947/**
1948 * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1949 * @state: PM transition of the system being carried out.
1950 *
1951 * Execute the ->prepare() callback(s) for all devices.
1952 */
1953int dpm_prepare(pm_message_t state)
1954{
1955 int error = 0;
1956
1957 trace_suspend_resume(TPS("dpm_prepare"), state.event, true);
1958 might_sleep();
1959
1960 /*
1961 * Give a chance for the known devices to complete their probes, before
1962 * disable probing of devices. This sync point is important at least
1963 * at boot time + hibernation restore.
1964 */
1965 wait_for_device_probe();
1966 /*
1967 * It is unsafe if probing of devices will happen during suspend or
1968 * hibernation and system behavior will be unpredictable in this case.
1969 * So, let's prohibit device's probing here and defer their probes
1970 * instead. The normal behavior will be restored in dpm_complete().
1971 */
1972 device_block_probing();
1973
1974 mutex_lock(&dpm_list_mtx);
1975 while (!list_empty(&dpm_list)) {
1976 struct device *dev = to_device(dpm_list.next);
1977
1978 get_device(dev);
1979 mutex_unlock(&dpm_list_mtx);
1980
1981 trace_device_pm_callback_start(dev, "", state.event);
1982 error = device_prepare(dev, state);
1983 trace_device_pm_callback_end(dev, error);
1984
1985 mutex_lock(&dpm_list_mtx);
1986 if (error) {
1987 if (error == -EAGAIN) {
1988 put_device(dev);
1989 error = 0;
1990 continue;
1991 }
1992 pr_info("Device %s not prepared for power transition: code %d\n",
1993 dev_name(dev), error);
1994 put_device(dev);
1995 break;
1996 }
1997 dev->power.is_prepared = true;
1998 if (!list_empty(&dev->power.entry))
1999 list_move_tail(&dev->power.entry, &dpm_prepared_list);
2000 put_device(dev);
2001 }
2002 mutex_unlock(&dpm_list_mtx);
2003 trace_suspend_resume(TPS("dpm_prepare"), state.event, false);
2004 return error;
2005}
2006
2007/**
2008 * dpm_suspend_start - Prepare devices for PM transition and suspend them.
2009 * @state: PM transition of the system being carried out.
2010 *
2011 * Prepare all non-sysdev devices for system PM transition and execute "suspend"
2012 * callbacks for them.
2013 */
2014int dpm_suspend_start(pm_message_t state)
2015{
2016 ktime_t starttime = ktime_get();
2017 int error;
2018
2019 error = dpm_prepare(state);
2020 if (error) {
2021 suspend_stats.failed_prepare++;
2022 dpm_save_failed_step(SUSPEND_PREPARE);
2023 } else
2024 error = dpm_suspend(state);
2025 dpm_show_time(starttime, state, error, "start");
2026 return error;
2027}
2028EXPORT_SYMBOL_GPL(dpm_suspend_start);
2029
2030void __suspend_report_result(const char *function, void *fn, int ret)
2031{
2032 if (ret)
2033 pr_err("%s(): %pS returns %d\n", function, fn, ret);
2034}
2035EXPORT_SYMBOL_GPL(__suspend_report_result);
2036
2037/**
2038 * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
2039 * @subordinate: Device that needs to wait for @dev.
2040 * @dev: Device to wait for.
2041 */
2042int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
2043{
2044 dpm_wait(dev, subordinate->power.async_suspend);
2045 return async_error;
2046}
2047EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);
2048
2049/**
2050 * dpm_for_each_dev - device iterator.
2051 * @data: data for the callback.
2052 * @fn: function to be called for each device.
2053 *
2054 * Iterate over devices in dpm_list, and call @fn for each device,
2055 * passing it @data.
2056 */
2057void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *))
2058{
2059 struct device *dev;
2060
2061 if (!fn)
2062 return;
2063
2064 device_pm_lock();
2065 list_for_each_entry(dev, &dpm_list, power.entry)
2066 fn(dev, data);
2067 device_pm_unlock();
2068}
2069EXPORT_SYMBOL_GPL(dpm_for_each_dev);
2070
2071static bool pm_ops_is_empty(const struct dev_pm_ops *ops)
2072{
2073 if (!ops)
2074 return true;
2075
2076 return !ops->prepare &&
2077 !ops->suspend &&
2078 !ops->suspend_late &&
2079 !ops->suspend_noirq &&
2080 !ops->resume_noirq &&
2081 !ops->resume_early &&
2082 !ops->resume &&
2083 !ops->complete;
2084}
2085
2086void device_pm_check_callbacks(struct device *dev)
2087{
2088 spin_lock_irq(&dev->power.lock);
2089 dev->power.no_pm_callbacks =
2090 (!dev->bus || (pm_ops_is_empty(dev->bus->pm) &&
2091 !dev->bus->suspend && !dev->bus->resume)) &&
2092 (!dev->class || pm_ops_is_empty(dev->class->pm)) &&
2093 (!dev->type || pm_ops_is_empty(dev->type->pm)) &&
2094 (!dev->pm_domain || pm_ops_is_empty(&dev->pm_domain->ops)) &&
2095 (!dev->driver || (pm_ops_is_empty(dev->driver->pm) &&
2096 !dev->driver->suspend && !dev->driver->resume));
2097 spin_unlock_irq(&dev->power.lock);
2098}
2099
2100bool dev_pm_smart_suspend_and_suspended(struct device *dev)
2101{
2102 return dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) &&
2103 pm_runtime_status_suspended(dev);
2104}