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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/*
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/export.h>
23#include <linux/mutex.h>
24#include <linux/pm.h>
25#include <linux/pm_runtime.h>
26#include <linux/resume-trace.h>
27#include <linux/interrupt.h>
28#include <linux/sched.h>
29#include <linux/async.h>
30#include <linux/suspend.h>
31#include <trace/events/power.h>
32#include <linux/cpufreq.h>
33#include <linux/cpuidle.h>
34#include <linux/timer.h>
35
36#include "../base.h"
37#include "power.h"
38
39typedef int (*pm_callback_t)(struct device *);
40
41/*
42 * The entries in the dpm_list list are in a depth first order, simply
43 * because children are guaranteed to be discovered after parents, and
44 * are inserted at the back of the list on discovery.
45 *
46 * Since device_pm_add() may be called with a device lock held,
47 * we must never try to acquire a device lock while holding
48 * dpm_list_mutex.
49 */
50
51LIST_HEAD(dpm_list);
52static LIST_HEAD(dpm_prepared_list);
53static LIST_HEAD(dpm_suspended_list);
54static LIST_HEAD(dpm_late_early_list);
55static LIST_HEAD(dpm_noirq_list);
56
57struct suspend_stats suspend_stats;
58static DEFINE_MUTEX(dpm_list_mtx);
59static pm_message_t pm_transition;
60
61static int async_error;
62
63static char *pm_verb(int event)
64{
65 switch (event) {
66 case PM_EVENT_SUSPEND:
67 return "suspend";
68 case PM_EVENT_RESUME:
69 return "resume";
70 case PM_EVENT_FREEZE:
71 return "freeze";
72 case PM_EVENT_QUIESCE:
73 return "quiesce";
74 case PM_EVENT_HIBERNATE:
75 return "hibernate";
76 case PM_EVENT_THAW:
77 return "thaw";
78 case PM_EVENT_RESTORE:
79 return "restore";
80 case PM_EVENT_RECOVER:
81 return "recover";
82 default:
83 return "(unknown PM event)";
84 }
85}
86
87/**
88 * device_pm_sleep_init - Initialize system suspend-related device fields.
89 * @dev: Device object being initialized.
90 */
91void device_pm_sleep_init(struct device *dev)
92{
93 dev->power.is_prepared = false;
94 dev->power.is_suspended = false;
95 dev->power.is_noirq_suspended = false;
96 dev->power.is_late_suspended = false;
97 init_completion(&dev->power.completion);
98 complete_all(&dev->power.completion);
99 dev->power.wakeup = NULL;
100 INIT_LIST_HEAD(&dev->power.entry);
101}
102
103/**
104 * device_pm_lock - Lock the list of active devices used by the PM core.
105 */
106void device_pm_lock(void)
107{
108 mutex_lock(&dpm_list_mtx);
109}
110
111/**
112 * device_pm_unlock - Unlock the list of active devices used by the PM core.
113 */
114void device_pm_unlock(void)
115{
116 mutex_unlock(&dpm_list_mtx);
117}
118
119/**
120 * device_pm_add - Add a device to the PM core's list of active devices.
121 * @dev: Device to add to the list.
122 */
123void device_pm_add(struct device *dev)
124{
125 pr_debug("PM: Adding info for %s:%s\n",
126 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
127 mutex_lock(&dpm_list_mtx);
128 if (dev->parent && dev->parent->power.is_prepared)
129 dev_warn(dev, "parent %s should not be sleeping\n",
130 dev_name(dev->parent));
131 list_add_tail(&dev->power.entry, &dpm_list);
132 mutex_unlock(&dpm_list_mtx);
133}
134
135/**
136 * device_pm_remove - Remove a device from the PM core's list of active devices.
137 * @dev: Device to be removed from the list.
138 */
139void device_pm_remove(struct device *dev)
140{
141 pr_debug("PM: Removing info for %s:%s\n",
142 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
143 complete_all(&dev->power.completion);
144 mutex_lock(&dpm_list_mtx);
145 list_del_init(&dev->power.entry);
146 mutex_unlock(&dpm_list_mtx);
147 device_wakeup_disable(dev);
148 pm_runtime_remove(dev);
149}
150
151/**
152 * device_pm_move_before - Move device in the PM core's list of active devices.
153 * @deva: Device to move in dpm_list.
154 * @devb: Device @deva should come before.
155 */
156void device_pm_move_before(struct device *deva, struct device *devb)
157{
158 pr_debug("PM: Moving %s:%s before %s:%s\n",
159 deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
160 devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
161 /* Delete deva from dpm_list and reinsert before devb. */
162 list_move_tail(&deva->power.entry, &devb->power.entry);
163}
164
165/**
166 * device_pm_move_after - Move device in the PM core's list of active devices.
167 * @deva: Device to move in dpm_list.
168 * @devb: Device @deva should come after.
169 */
170void device_pm_move_after(struct device *deva, struct device *devb)
171{
172 pr_debug("PM: Moving %s:%s after %s:%s\n",
173 deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
174 devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
175 /* Delete deva from dpm_list and reinsert after devb. */
176 list_move(&deva->power.entry, &devb->power.entry);
177}
178
179/**
180 * device_pm_move_last - Move device to end of the PM core's list of devices.
181 * @dev: Device to move in dpm_list.
182 */
183void device_pm_move_last(struct device *dev)
184{
185 pr_debug("PM: Moving %s:%s to end of list\n",
186 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
187 list_move_tail(&dev->power.entry, &dpm_list);
188}
189
190static ktime_t initcall_debug_start(struct device *dev)
191{
192 ktime_t calltime = ktime_set(0, 0);
193
194 if (pm_print_times_enabled) {
195 pr_info("calling %s+ @ %i, parent: %s\n",
196 dev_name(dev), task_pid_nr(current),
197 dev->parent ? dev_name(dev->parent) : "none");
198 calltime = ktime_get();
199 }
200
201 return calltime;
202}
203
204static void initcall_debug_report(struct device *dev, ktime_t calltime,
205 int error, pm_message_t state, char *info)
206{
207 ktime_t rettime;
208 s64 nsecs;
209
210 rettime = ktime_get();
211 nsecs = (s64) ktime_to_ns(ktime_sub(rettime, calltime));
212
213 if (pm_print_times_enabled) {
214 pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev),
215 error, (unsigned long long)nsecs >> 10);
216 }
217
218 trace_device_pm_report_time(dev, info, nsecs, pm_verb(state.event),
219 error);
220}
221
222/**
223 * dpm_wait - Wait for a PM operation to complete.
224 * @dev: Device to wait for.
225 * @async: If unset, wait only if the device's power.async_suspend flag is set.
226 */
227static void dpm_wait(struct device *dev, bool async)
228{
229 if (!dev)
230 return;
231
232 if (async || (pm_async_enabled && dev->power.async_suspend))
233 wait_for_completion(&dev->power.completion);
234}
235
236static int dpm_wait_fn(struct device *dev, void *async_ptr)
237{
238 dpm_wait(dev, *((bool *)async_ptr));
239 return 0;
240}
241
242static void dpm_wait_for_children(struct device *dev, bool async)
243{
244 device_for_each_child(dev, &async, dpm_wait_fn);
245}
246
247/**
248 * pm_op - Return the PM operation appropriate for given PM event.
249 * @ops: PM operations to choose from.
250 * @state: PM transition of the system being carried out.
251 */
252static pm_callback_t pm_op(const struct dev_pm_ops *ops, pm_message_t state)
253{
254 switch (state.event) {
255#ifdef CONFIG_SUSPEND
256 case PM_EVENT_SUSPEND:
257 return ops->suspend;
258 case PM_EVENT_RESUME:
259 return ops->resume;
260#endif /* CONFIG_SUSPEND */
261#ifdef CONFIG_HIBERNATE_CALLBACKS
262 case PM_EVENT_FREEZE:
263 case PM_EVENT_QUIESCE:
264 return ops->freeze;
265 case PM_EVENT_HIBERNATE:
266 return ops->poweroff;
267 case PM_EVENT_THAW:
268 case PM_EVENT_RECOVER:
269 return ops->thaw;
270 break;
271 case PM_EVENT_RESTORE:
272 return ops->restore;
273#endif /* CONFIG_HIBERNATE_CALLBACKS */
274 }
275
276 return NULL;
277}
278
279/**
280 * pm_late_early_op - Return the PM operation appropriate for given PM event.
281 * @ops: PM operations to choose from.
282 * @state: PM transition of the system being carried out.
283 *
284 * Runtime PM is disabled for @dev while this function is being executed.
285 */
286static pm_callback_t pm_late_early_op(const struct dev_pm_ops *ops,
287 pm_message_t state)
288{
289 switch (state.event) {
290#ifdef CONFIG_SUSPEND
291 case PM_EVENT_SUSPEND:
292 return ops->suspend_late;
293 case PM_EVENT_RESUME:
294 return ops->resume_early;
295#endif /* CONFIG_SUSPEND */
296#ifdef CONFIG_HIBERNATE_CALLBACKS
297 case PM_EVENT_FREEZE:
298 case PM_EVENT_QUIESCE:
299 return ops->freeze_late;
300 case PM_EVENT_HIBERNATE:
301 return ops->poweroff_late;
302 case PM_EVENT_THAW:
303 case PM_EVENT_RECOVER:
304 return ops->thaw_early;
305 case PM_EVENT_RESTORE:
306 return ops->restore_early;
307#endif /* CONFIG_HIBERNATE_CALLBACKS */
308 }
309
310 return NULL;
311}
312
313/**
314 * pm_noirq_op - Return the PM operation appropriate for given PM event.
315 * @ops: PM operations to choose from.
316 * @state: PM transition of the system being carried out.
317 *
318 * The driver of @dev will not receive interrupts while this function is being
319 * executed.
320 */
321static pm_callback_t pm_noirq_op(const struct dev_pm_ops *ops, pm_message_t state)
322{
323 switch (state.event) {
324#ifdef CONFIG_SUSPEND
325 case PM_EVENT_SUSPEND:
326 return ops->suspend_noirq;
327 case PM_EVENT_RESUME:
328 return ops->resume_noirq;
329#endif /* CONFIG_SUSPEND */
330#ifdef CONFIG_HIBERNATE_CALLBACKS
331 case PM_EVENT_FREEZE:
332 case PM_EVENT_QUIESCE:
333 return ops->freeze_noirq;
334 case PM_EVENT_HIBERNATE:
335 return ops->poweroff_noirq;
336 case PM_EVENT_THAW:
337 case PM_EVENT_RECOVER:
338 return ops->thaw_noirq;
339 case PM_EVENT_RESTORE:
340 return ops->restore_noirq;
341#endif /* CONFIG_HIBERNATE_CALLBACKS */
342 }
343
344 return NULL;
345}
346
347static void pm_dev_dbg(struct device *dev, pm_message_t state, char *info)
348{
349 dev_dbg(dev, "%s%s%s\n", info, pm_verb(state.event),
350 ((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
351 ", may wakeup" : "");
352}
353
354static void pm_dev_err(struct device *dev, pm_message_t state, char *info,
355 int error)
356{
357 printk(KERN_ERR "PM: Device %s failed to %s%s: error %d\n",
358 dev_name(dev), pm_verb(state.event), info, error);
359}
360
361static void dpm_show_time(ktime_t starttime, pm_message_t state, char *info)
362{
363 ktime_t calltime;
364 u64 usecs64;
365 int usecs;
366
367 calltime = ktime_get();
368 usecs64 = ktime_to_ns(ktime_sub(calltime, starttime));
369 do_div(usecs64, NSEC_PER_USEC);
370 usecs = usecs64;
371 if (usecs == 0)
372 usecs = 1;
373 pr_info("PM: %s%s%s of devices complete after %ld.%03ld msecs\n",
374 info ?: "", info ? " " : "", pm_verb(state.event),
375 usecs / USEC_PER_MSEC, usecs % USEC_PER_MSEC);
376}
377
378static int dpm_run_callback(pm_callback_t cb, struct device *dev,
379 pm_message_t state, char *info)
380{
381 ktime_t calltime;
382 int error;
383
384 if (!cb)
385 return 0;
386
387 calltime = initcall_debug_start(dev);
388
389 pm_dev_dbg(dev, state, info);
390 error = cb(dev);
391 suspend_report_result(cb, error);
392
393 initcall_debug_report(dev, calltime, error, state, info);
394
395 return error;
396}
397
398#ifdef CONFIG_DPM_WATCHDOG
399struct dpm_watchdog {
400 struct device *dev;
401 struct task_struct *tsk;
402 struct timer_list timer;
403};
404
405#define DECLARE_DPM_WATCHDOG_ON_STACK(wd) \
406 struct dpm_watchdog wd
407
408/**
409 * dpm_watchdog_handler - Driver suspend / resume watchdog handler.
410 * @data: Watchdog object address.
411 *
412 * Called when a driver has timed out suspending or resuming.
413 * There's not much we can do here to recover so panic() to
414 * capture a crash-dump in pstore.
415 */
416static void dpm_watchdog_handler(unsigned long data)
417{
418 struct dpm_watchdog *wd = (void *)data;
419
420 dev_emerg(wd->dev, "**** DPM device timeout ****\n");
421 show_stack(wd->tsk, NULL);
422 panic("%s %s: unrecoverable failure\n",
423 dev_driver_string(wd->dev), dev_name(wd->dev));
424}
425
426/**
427 * dpm_watchdog_set - Enable pm watchdog for given device.
428 * @wd: Watchdog. Must be allocated on the stack.
429 * @dev: Device to handle.
430 */
431static void dpm_watchdog_set(struct dpm_watchdog *wd, struct device *dev)
432{
433 struct timer_list *timer = &wd->timer;
434
435 wd->dev = dev;
436 wd->tsk = current;
437
438 init_timer_on_stack(timer);
439 /* use same timeout value for both suspend and resume */
440 timer->expires = jiffies + HZ * CONFIG_DPM_WATCHDOG_TIMEOUT;
441 timer->function = dpm_watchdog_handler;
442 timer->data = (unsigned long)wd;
443 add_timer(timer);
444}
445
446/**
447 * dpm_watchdog_clear - Disable suspend/resume watchdog.
448 * @wd: Watchdog to disable.
449 */
450static void dpm_watchdog_clear(struct dpm_watchdog *wd)
451{
452 struct timer_list *timer = &wd->timer;
453
454 del_timer_sync(timer);
455 destroy_timer_on_stack(timer);
456}
457#else
458#define DECLARE_DPM_WATCHDOG_ON_STACK(wd)
459#define dpm_watchdog_set(x, y)
460#define dpm_watchdog_clear(x)
461#endif
462
463/*------------------------- Resume routines -------------------------*/
464
465/**
466 * device_resume_noirq - Execute an "early resume" callback for given device.
467 * @dev: Device to handle.
468 * @state: PM transition of the system being carried out.
469 *
470 * The driver of @dev will not receive interrupts while this function is being
471 * executed.
472 */
473static int device_resume_noirq(struct device *dev, pm_message_t state, bool async)
474{
475 pm_callback_t callback = NULL;
476 char *info = NULL;
477 int error = 0;
478
479 TRACE_DEVICE(dev);
480 TRACE_RESUME(0);
481
482 if (dev->power.syscore)
483 goto Out;
484
485 if (!dev->power.is_noirq_suspended)
486 goto Out;
487
488 dpm_wait(dev->parent, async);
489
490 if (dev->pm_domain) {
491 info = "noirq power domain ";
492 callback = pm_noirq_op(&dev->pm_domain->ops, state);
493 } else if (dev->type && dev->type->pm) {
494 info = "noirq type ";
495 callback = pm_noirq_op(dev->type->pm, state);
496 } else if (dev->class && dev->class->pm) {
497 info = "noirq class ";
498 callback = pm_noirq_op(dev->class->pm, state);
499 } else if (dev->bus && dev->bus->pm) {
500 info = "noirq bus ";
501 callback = pm_noirq_op(dev->bus->pm, state);
502 }
503
504 if (!callback && dev->driver && dev->driver->pm) {
505 info = "noirq driver ";
506 callback = pm_noirq_op(dev->driver->pm, state);
507 }
508
509 error = dpm_run_callback(callback, dev, state, info);
510 dev->power.is_noirq_suspended = false;
511
512 Out:
513 complete_all(&dev->power.completion);
514 TRACE_RESUME(error);
515 return error;
516}
517
518static bool is_async(struct device *dev)
519{
520 return dev->power.async_suspend && pm_async_enabled
521 && !pm_trace_is_enabled();
522}
523
524static void async_resume_noirq(void *data, async_cookie_t cookie)
525{
526 struct device *dev = (struct device *)data;
527 int error;
528
529 error = device_resume_noirq(dev, pm_transition, true);
530 if (error)
531 pm_dev_err(dev, pm_transition, " async", error);
532
533 put_device(dev);
534}
535
536/**
537 * dpm_resume_noirq - Execute "noirq resume" callbacks for all devices.
538 * @state: PM transition of the system being carried out.
539 *
540 * Call the "noirq" resume handlers for all devices in dpm_noirq_list and
541 * enable device drivers to receive interrupts.
542 */
543static void dpm_resume_noirq(pm_message_t state)
544{
545 struct device *dev;
546 ktime_t starttime = ktime_get();
547
548 mutex_lock(&dpm_list_mtx);
549 pm_transition = state;
550
551 /*
552 * Advanced the async threads upfront,
553 * in case the starting of async threads is
554 * delayed by non-async resuming devices.
555 */
556 list_for_each_entry(dev, &dpm_noirq_list, power.entry) {
557 reinit_completion(&dev->power.completion);
558 if (is_async(dev)) {
559 get_device(dev);
560 async_schedule(async_resume_noirq, dev);
561 }
562 }
563
564 while (!list_empty(&dpm_noirq_list)) {
565 dev = to_device(dpm_noirq_list.next);
566 get_device(dev);
567 list_move_tail(&dev->power.entry, &dpm_late_early_list);
568 mutex_unlock(&dpm_list_mtx);
569
570 if (!is_async(dev)) {
571 int error;
572
573 error = device_resume_noirq(dev, state, false);
574 if (error) {
575 suspend_stats.failed_resume_noirq++;
576 dpm_save_failed_step(SUSPEND_RESUME_NOIRQ);
577 dpm_save_failed_dev(dev_name(dev));
578 pm_dev_err(dev, state, " noirq", error);
579 }
580 }
581
582 mutex_lock(&dpm_list_mtx);
583 put_device(dev);
584 }
585 mutex_unlock(&dpm_list_mtx);
586 async_synchronize_full();
587 dpm_show_time(starttime, state, "noirq");
588 resume_device_irqs();
589 cpuidle_resume();
590}
591
592/**
593 * device_resume_early - Execute an "early resume" callback for given device.
594 * @dev: Device to handle.
595 * @state: PM transition of the system being carried out.
596 *
597 * Runtime PM is disabled for @dev while this function is being executed.
598 */
599static int device_resume_early(struct device *dev, pm_message_t state, bool async)
600{
601 pm_callback_t callback = NULL;
602 char *info = NULL;
603 int error = 0;
604
605 TRACE_DEVICE(dev);
606 TRACE_RESUME(0);
607
608 if (dev->power.syscore)
609 goto Out;
610
611 if (!dev->power.is_late_suspended)
612 goto Out;
613
614 dpm_wait(dev->parent, async);
615
616 if (dev->pm_domain) {
617 info = "early power domain ";
618 callback = pm_late_early_op(&dev->pm_domain->ops, state);
619 } else if (dev->type && dev->type->pm) {
620 info = "early type ";
621 callback = pm_late_early_op(dev->type->pm, state);
622 } else if (dev->class && dev->class->pm) {
623 info = "early class ";
624 callback = pm_late_early_op(dev->class->pm, state);
625 } else if (dev->bus && dev->bus->pm) {
626 info = "early bus ";
627 callback = pm_late_early_op(dev->bus->pm, state);
628 }
629
630 if (!callback && dev->driver && dev->driver->pm) {
631 info = "early driver ";
632 callback = pm_late_early_op(dev->driver->pm, state);
633 }
634
635 error = dpm_run_callback(callback, dev, state, info);
636 dev->power.is_late_suspended = false;
637
638 Out:
639 TRACE_RESUME(error);
640
641 pm_runtime_enable(dev);
642 complete_all(&dev->power.completion);
643 return error;
644}
645
646static void async_resume_early(void *data, async_cookie_t cookie)
647{
648 struct device *dev = (struct device *)data;
649 int error;
650
651 error = device_resume_early(dev, pm_transition, true);
652 if (error)
653 pm_dev_err(dev, pm_transition, " async", error);
654
655 put_device(dev);
656}
657
658/**
659 * dpm_resume_early - Execute "early resume" callbacks for all devices.
660 * @state: PM transition of the system being carried out.
661 */
662static void dpm_resume_early(pm_message_t state)
663{
664 struct device *dev;
665 ktime_t starttime = ktime_get();
666
667 mutex_lock(&dpm_list_mtx);
668 pm_transition = state;
669
670 /*
671 * Advanced the async threads upfront,
672 * in case the starting of async threads is
673 * delayed by non-async resuming devices.
674 */
675 list_for_each_entry(dev, &dpm_late_early_list, power.entry) {
676 reinit_completion(&dev->power.completion);
677 if (is_async(dev)) {
678 get_device(dev);
679 async_schedule(async_resume_early, dev);
680 }
681 }
682
683 while (!list_empty(&dpm_late_early_list)) {
684 dev = to_device(dpm_late_early_list.next);
685 get_device(dev);
686 list_move_tail(&dev->power.entry, &dpm_suspended_list);
687 mutex_unlock(&dpm_list_mtx);
688
689 if (!is_async(dev)) {
690 int error;
691
692 error = device_resume_early(dev, state, false);
693 if (error) {
694 suspend_stats.failed_resume_early++;
695 dpm_save_failed_step(SUSPEND_RESUME_EARLY);
696 dpm_save_failed_dev(dev_name(dev));
697 pm_dev_err(dev, state, " early", error);
698 }
699 }
700 mutex_lock(&dpm_list_mtx);
701 put_device(dev);
702 }
703 mutex_unlock(&dpm_list_mtx);
704 async_synchronize_full();
705 dpm_show_time(starttime, state, "early");
706}
707
708/**
709 * dpm_resume_start - Execute "noirq" and "early" device callbacks.
710 * @state: PM transition of the system being carried out.
711 */
712void dpm_resume_start(pm_message_t state)
713{
714 dpm_resume_noirq(state);
715 dpm_resume_early(state);
716}
717EXPORT_SYMBOL_GPL(dpm_resume_start);
718
719/**
720 * device_resume - Execute "resume" callbacks for given device.
721 * @dev: Device to handle.
722 * @state: PM transition of the system being carried out.
723 * @async: If true, the device is being resumed asynchronously.
724 */
725static int device_resume(struct device *dev, pm_message_t state, bool async)
726{
727 pm_callback_t callback = NULL;
728 char *info = NULL;
729 int error = 0;
730 DECLARE_DPM_WATCHDOG_ON_STACK(wd);
731
732 TRACE_DEVICE(dev);
733 TRACE_RESUME(0);
734
735 if (dev->power.syscore)
736 goto Complete;
737
738 dpm_wait(dev->parent, async);
739 dpm_watchdog_set(&wd, dev);
740 device_lock(dev);
741
742 /*
743 * This is a fib. But we'll allow new children to be added below
744 * a resumed device, even if the device hasn't been completed yet.
745 */
746 dev->power.is_prepared = false;
747
748 if (!dev->power.is_suspended)
749 goto Unlock;
750
751 if (dev->pm_domain) {
752 info = "power domain ";
753 callback = pm_op(&dev->pm_domain->ops, state);
754 goto Driver;
755 }
756
757 if (dev->type && dev->type->pm) {
758 info = "type ";
759 callback = pm_op(dev->type->pm, state);
760 goto Driver;
761 }
762
763 if (dev->class) {
764 if (dev->class->pm) {
765 info = "class ";
766 callback = pm_op(dev->class->pm, state);
767 goto Driver;
768 } else if (dev->class->resume) {
769 info = "legacy class ";
770 callback = dev->class->resume;
771 goto End;
772 }
773 }
774
775 if (dev->bus) {
776 if (dev->bus->pm) {
777 info = "bus ";
778 callback = pm_op(dev->bus->pm, state);
779 } else if (dev->bus->resume) {
780 info = "legacy bus ";
781 callback = dev->bus->resume;
782 goto End;
783 }
784 }
785
786 Driver:
787 if (!callback && dev->driver && dev->driver->pm) {
788 info = "driver ";
789 callback = pm_op(dev->driver->pm, state);
790 }
791
792 End:
793 error = dpm_run_callback(callback, dev, state, info);
794 dev->power.is_suspended = false;
795
796 Unlock:
797 device_unlock(dev);
798 dpm_watchdog_clear(&wd);
799
800 Complete:
801 complete_all(&dev->power.completion);
802
803 TRACE_RESUME(error);
804
805 return error;
806}
807
808static void async_resume(void *data, async_cookie_t cookie)
809{
810 struct device *dev = (struct device *)data;
811 int error;
812
813 error = device_resume(dev, pm_transition, true);
814 if (error)
815 pm_dev_err(dev, pm_transition, " async", error);
816 put_device(dev);
817}
818
819/**
820 * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
821 * @state: PM transition of the system being carried out.
822 *
823 * Execute the appropriate "resume" callback for all devices whose status
824 * indicates that they are suspended.
825 */
826void dpm_resume(pm_message_t state)
827{
828 struct device *dev;
829 ktime_t starttime = ktime_get();
830
831 might_sleep();
832
833 mutex_lock(&dpm_list_mtx);
834 pm_transition = state;
835 async_error = 0;
836
837 list_for_each_entry(dev, &dpm_suspended_list, power.entry) {
838 reinit_completion(&dev->power.completion);
839 if (is_async(dev)) {
840 get_device(dev);
841 async_schedule(async_resume, dev);
842 }
843 }
844
845 while (!list_empty(&dpm_suspended_list)) {
846 dev = to_device(dpm_suspended_list.next);
847 get_device(dev);
848 if (!is_async(dev)) {
849 int error;
850
851 mutex_unlock(&dpm_list_mtx);
852
853 error = device_resume(dev, state, false);
854 if (error) {
855 suspend_stats.failed_resume++;
856 dpm_save_failed_step(SUSPEND_RESUME);
857 dpm_save_failed_dev(dev_name(dev));
858 pm_dev_err(dev, state, "", error);
859 }
860
861 mutex_lock(&dpm_list_mtx);
862 }
863 if (!list_empty(&dev->power.entry))
864 list_move_tail(&dev->power.entry, &dpm_prepared_list);
865 put_device(dev);
866 }
867 mutex_unlock(&dpm_list_mtx);
868 async_synchronize_full();
869 dpm_show_time(starttime, state, NULL);
870
871 cpufreq_resume();
872}
873
874/**
875 * device_complete - Complete a PM transition for given device.
876 * @dev: Device to handle.
877 * @state: PM transition of the system being carried out.
878 */
879static void device_complete(struct device *dev, pm_message_t state)
880{
881 void (*callback)(struct device *) = NULL;
882 char *info = NULL;
883
884 if (dev->power.syscore)
885 return;
886
887 device_lock(dev);
888
889 if (dev->pm_domain) {
890 info = "completing power domain ";
891 callback = dev->pm_domain->ops.complete;
892 } else if (dev->type && dev->type->pm) {
893 info = "completing type ";
894 callback = dev->type->pm->complete;
895 } else if (dev->class && dev->class->pm) {
896 info = "completing class ";
897 callback = dev->class->pm->complete;
898 } else if (dev->bus && dev->bus->pm) {
899 info = "completing bus ";
900 callback = dev->bus->pm->complete;
901 }
902
903 if (!callback && dev->driver && dev->driver->pm) {
904 info = "completing driver ";
905 callback = dev->driver->pm->complete;
906 }
907
908 if (callback) {
909 pm_dev_dbg(dev, state, info);
910 callback(dev);
911 }
912
913 device_unlock(dev);
914
915 pm_runtime_put(dev);
916}
917
918/**
919 * dpm_complete - Complete a PM transition for all non-sysdev devices.
920 * @state: PM transition of the system being carried out.
921 *
922 * Execute the ->complete() callbacks for all devices whose PM status is not
923 * DPM_ON (this allows new devices to be registered).
924 */
925void dpm_complete(pm_message_t state)
926{
927 struct list_head list;
928
929 might_sleep();
930
931 INIT_LIST_HEAD(&list);
932 mutex_lock(&dpm_list_mtx);
933 while (!list_empty(&dpm_prepared_list)) {
934 struct device *dev = to_device(dpm_prepared_list.prev);
935
936 get_device(dev);
937 dev->power.is_prepared = false;
938 list_move(&dev->power.entry, &list);
939 mutex_unlock(&dpm_list_mtx);
940
941 device_complete(dev, state);
942
943 mutex_lock(&dpm_list_mtx);
944 put_device(dev);
945 }
946 list_splice(&list, &dpm_list);
947 mutex_unlock(&dpm_list_mtx);
948}
949
950/**
951 * dpm_resume_end - Execute "resume" callbacks and complete system transition.
952 * @state: PM transition of the system being carried out.
953 *
954 * Execute "resume" callbacks for all devices and complete the PM transition of
955 * the system.
956 */
957void dpm_resume_end(pm_message_t state)
958{
959 dpm_resume(state);
960 dpm_complete(state);
961}
962EXPORT_SYMBOL_GPL(dpm_resume_end);
963
964
965/*------------------------- Suspend routines -------------------------*/
966
967/**
968 * resume_event - Return a "resume" message for given "suspend" sleep state.
969 * @sleep_state: PM message representing a sleep state.
970 *
971 * Return a PM message representing the resume event corresponding to given
972 * sleep state.
973 */
974static pm_message_t resume_event(pm_message_t sleep_state)
975{
976 switch (sleep_state.event) {
977 case PM_EVENT_SUSPEND:
978 return PMSG_RESUME;
979 case PM_EVENT_FREEZE:
980 case PM_EVENT_QUIESCE:
981 return PMSG_RECOVER;
982 case PM_EVENT_HIBERNATE:
983 return PMSG_RESTORE;
984 }
985 return PMSG_ON;
986}
987
988/**
989 * device_suspend_noirq - Execute a "late suspend" callback for given device.
990 * @dev: Device to handle.
991 * @state: PM transition of the system being carried out.
992 *
993 * The driver of @dev will not receive interrupts while this function is being
994 * executed.
995 */
996static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool async)
997{
998 pm_callback_t callback = NULL;
999 char *info = NULL;
1000 int error = 0;
1001
1002 if (async_error)
1003 goto Complete;
1004
1005 if (pm_wakeup_pending()) {
1006 async_error = -EBUSY;
1007 goto Complete;
1008 }
1009
1010 if (dev->power.syscore)
1011 goto Complete;
1012
1013 dpm_wait_for_children(dev, async);
1014
1015 if (dev->pm_domain) {
1016 info = "noirq power domain ";
1017 callback = pm_noirq_op(&dev->pm_domain->ops, state);
1018 } else if (dev->type && dev->type->pm) {
1019 info = "noirq type ";
1020 callback = pm_noirq_op(dev->type->pm, state);
1021 } else if (dev->class && dev->class->pm) {
1022 info = "noirq class ";
1023 callback = pm_noirq_op(dev->class->pm, state);
1024 } else if (dev->bus && dev->bus->pm) {
1025 info = "noirq bus ";
1026 callback = pm_noirq_op(dev->bus->pm, state);
1027 }
1028
1029 if (!callback && dev->driver && dev->driver->pm) {
1030 info = "noirq driver ";
1031 callback = pm_noirq_op(dev->driver->pm, state);
1032 }
1033
1034 error = dpm_run_callback(callback, dev, state, info);
1035 if (!error)
1036 dev->power.is_noirq_suspended = true;
1037 else
1038 async_error = error;
1039
1040Complete:
1041 complete_all(&dev->power.completion);
1042 return error;
1043}
1044
1045static void async_suspend_noirq(void *data, async_cookie_t cookie)
1046{
1047 struct device *dev = (struct device *)data;
1048 int error;
1049
1050 error = __device_suspend_noirq(dev, pm_transition, true);
1051 if (error) {
1052 dpm_save_failed_dev(dev_name(dev));
1053 pm_dev_err(dev, pm_transition, " async", error);
1054 }
1055
1056 put_device(dev);
1057}
1058
1059static int device_suspend_noirq(struct device *dev)
1060{
1061 reinit_completion(&dev->power.completion);
1062
1063 if (pm_async_enabled && dev->power.async_suspend) {
1064 get_device(dev);
1065 async_schedule(async_suspend_noirq, dev);
1066 return 0;
1067 }
1068 return __device_suspend_noirq(dev, pm_transition, false);
1069}
1070
1071/**
1072 * dpm_suspend_noirq - Execute "noirq suspend" callbacks for all devices.
1073 * @state: PM transition of the system being carried out.
1074 *
1075 * Prevent device drivers from receiving interrupts and call the "noirq" suspend
1076 * handlers for all non-sysdev devices.
1077 */
1078static int dpm_suspend_noirq(pm_message_t state)
1079{
1080 ktime_t starttime = ktime_get();
1081 int error = 0;
1082
1083 cpuidle_pause();
1084 suspend_device_irqs();
1085 mutex_lock(&dpm_list_mtx);
1086 pm_transition = state;
1087 async_error = 0;
1088
1089 while (!list_empty(&dpm_late_early_list)) {
1090 struct device *dev = to_device(dpm_late_early_list.prev);
1091
1092 get_device(dev);
1093 mutex_unlock(&dpm_list_mtx);
1094
1095 error = device_suspend_noirq(dev);
1096
1097 mutex_lock(&dpm_list_mtx);
1098 if (error) {
1099 pm_dev_err(dev, state, " noirq", error);
1100 dpm_save_failed_dev(dev_name(dev));
1101 put_device(dev);
1102 break;
1103 }
1104 if (!list_empty(&dev->power.entry))
1105 list_move(&dev->power.entry, &dpm_noirq_list);
1106 put_device(dev);
1107
1108 if (async_error)
1109 break;
1110 }
1111 mutex_unlock(&dpm_list_mtx);
1112 async_synchronize_full();
1113 if (!error)
1114 error = async_error;
1115
1116 if (error) {
1117 suspend_stats.failed_suspend_noirq++;
1118 dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ);
1119 dpm_resume_noirq(resume_event(state));
1120 } else {
1121 dpm_show_time(starttime, state, "noirq");
1122 }
1123 return error;
1124}
1125
1126/**
1127 * device_suspend_late - Execute a "late suspend" callback for given device.
1128 * @dev: Device to handle.
1129 * @state: PM transition of the system being carried out.
1130 *
1131 * Runtime PM is disabled for @dev while this function is being executed.
1132 */
1133static int __device_suspend_late(struct device *dev, pm_message_t state, bool async)
1134{
1135 pm_callback_t callback = NULL;
1136 char *info = NULL;
1137 int error = 0;
1138
1139 __pm_runtime_disable(dev, false);
1140
1141 if (async_error)
1142 goto Complete;
1143
1144 if (pm_wakeup_pending()) {
1145 async_error = -EBUSY;
1146 goto Complete;
1147 }
1148
1149 if (dev->power.syscore)
1150 goto Complete;
1151
1152 dpm_wait_for_children(dev, async);
1153
1154 if (dev->pm_domain) {
1155 info = "late power domain ";
1156 callback = pm_late_early_op(&dev->pm_domain->ops, state);
1157 } else if (dev->type && dev->type->pm) {
1158 info = "late type ";
1159 callback = pm_late_early_op(dev->type->pm, state);
1160 } else if (dev->class && dev->class->pm) {
1161 info = "late class ";
1162 callback = pm_late_early_op(dev->class->pm, state);
1163 } else if (dev->bus && dev->bus->pm) {
1164 info = "late bus ";
1165 callback = pm_late_early_op(dev->bus->pm, state);
1166 }
1167
1168 if (!callback && dev->driver && dev->driver->pm) {
1169 info = "late driver ";
1170 callback = pm_late_early_op(dev->driver->pm, state);
1171 }
1172
1173 error = dpm_run_callback(callback, dev, state, info);
1174 if (!error)
1175 dev->power.is_late_suspended = true;
1176 else
1177 async_error = error;
1178
1179Complete:
1180 complete_all(&dev->power.completion);
1181 return error;
1182}
1183
1184static void async_suspend_late(void *data, async_cookie_t cookie)
1185{
1186 struct device *dev = (struct device *)data;
1187 int error;
1188
1189 error = __device_suspend_late(dev, pm_transition, true);
1190 if (error) {
1191 dpm_save_failed_dev(dev_name(dev));
1192 pm_dev_err(dev, pm_transition, " async", error);
1193 }
1194 put_device(dev);
1195}
1196
1197static int device_suspend_late(struct device *dev)
1198{
1199 reinit_completion(&dev->power.completion);
1200
1201 if (pm_async_enabled && dev->power.async_suspend) {
1202 get_device(dev);
1203 async_schedule(async_suspend_late, dev);
1204 return 0;
1205 }
1206
1207 return __device_suspend_late(dev, pm_transition, false);
1208}
1209
1210/**
1211 * dpm_suspend_late - Execute "late suspend" callbacks for all devices.
1212 * @state: PM transition of the system being carried out.
1213 */
1214static int dpm_suspend_late(pm_message_t state)
1215{
1216 ktime_t starttime = ktime_get();
1217 int error = 0;
1218
1219 mutex_lock(&dpm_list_mtx);
1220 pm_transition = state;
1221 async_error = 0;
1222
1223 while (!list_empty(&dpm_suspended_list)) {
1224 struct device *dev = to_device(dpm_suspended_list.prev);
1225
1226 get_device(dev);
1227 mutex_unlock(&dpm_list_mtx);
1228
1229 error = device_suspend_late(dev);
1230
1231 mutex_lock(&dpm_list_mtx);
1232 if (error) {
1233 pm_dev_err(dev, state, " late", error);
1234 dpm_save_failed_dev(dev_name(dev));
1235 put_device(dev);
1236 break;
1237 }
1238 if (!list_empty(&dev->power.entry))
1239 list_move(&dev->power.entry, &dpm_late_early_list);
1240 put_device(dev);
1241
1242 if (async_error)
1243 break;
1244 }
1245 mutex_unlock(&dpm_list_mtx);
1246 async_synchronize_full();
1247 if (error) {
1248 suspend_stats.failed_suspend_late++;
1249 dpm_save_failed_step(SUSPEND_SUSPEND_LATE);
1250 dpm_resume_early(resume_event(state));
1251 } else {
1252 dpm_show_time(starttime, state, "late");
1253 }
1254 return error;
1255}
1256
1257/**
1258 * dpm_suspend_end - Execute "late" and "noirq" device suspend callbacks.
1259 * @state: PM transition of the system being carried out.
1260 */
1261int dpm_suspend_end(pm_message_t state)
1262{
1263 int error = dpm_suspend_late(state);
1264 if (error)
1265 return error;
1266
1267 error = dpm_suspend_noirq(state);
1268 if (error) {
1269 dpm_resume_early(resume_event(state));
1270 return error;
1271 }
1272
1273 return 0;
1274}
1275EXPORT_SYMBOL_GPL(dpm_suspend_end);
1276
1277/**
1278 * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
1279 * @dev: Device to suspend.
1280 * @state: PM transition of the system being carried out.
1281 * @cb: Suspend callback to execute.
1282 */
1283static int legacy_suspend(struct device *dev, pm_message_t state,
1284 int (*cb)(struct device *dev, pm_message_t state),
1285 char *info)
1286{
1287 int error;
1288 ktime_t calltime;
1289
1290 calltime = initcall_debug_start(dev);
1291
1292 error = cb(dev, state);
1293 suspend_report_result(cb, error);
1294
1295 initcall_debug_report(dev, calltime, error, state, info);
1296
1297 return error;
1298}
1299
1300/**
1301 * device_suspend - Execute "suspend" callbacks for given device.
1302 * @dev: Device to handle.
1303 * @state: PM transition of the system being carried out.
1304 * @async: If true, the device is being suspended asynchronously.
1305 */
1306static int __device_suspend(struct device *dev, pm_message_t state, bool async)
1307{
1308 pm_callback_t callback = NULL;
1309 char *info = NULL;
1310 int error = 0;
1311 DECLARE_DPM_WATCHDOG_ON_STACK(wd);
1312
1313 dpm_wait_for_children(dev, async);
1314
1315 if (async_error)
1316 goto Complete;
1317
1318 /*
1319 * If a device configured to wake up the system from sleep states
1320 * has been suspended at run time and there's a resume request pending
1321 * for it, this is equivalent to the device signaling wakeup, so the
1322 * system suspend operation should be aborted.
1323 */
1324 if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
1325 pm_wakeup_event(dev, 0);
1326
1327 if (pm_wakeup_pending()) {
1328 async_error = -EBUSY;
1329 goto Complete;
1330 }
1331
1332 if (dev->power.syscore)
1333 goto Complete;
1334
1335 dpm_watchdog_set(&wd, dev);
1336 device_lock(dev);
1337
1338 if (dev->pm_domain) {
1339 info = "power domain ";
1340 callback = pm_op(&dev->pm_domain->ops, state);
1341 goto Run;
1342 }
1343
1344 if (dev->type && dev->type->pm) {
1345 info = "type ";
1346 callback = pm_op(dev->type->pm, state);
1347 goto Run;
1348 }
1349
1350 if (dev->class) {
1351 if (dev->class->pm) {
1352 info = "class ";
1353 callback = pm_op(dev->class->pm, state);
1354 goto Run;
1355 } else if (dev->class->suspend) {
1356 pm_dev_dbg(dev, state, "legacy class ");
1357 error = legacy_suspend(dev, state, dev->class->suspend,
1358 "legacy class ");
1359 goto End;
1360 }
1361 }
1362
1363 if (dev->bus) {
1364 if (dev->bus->pm) {
1365 info = "bus ";
1366 callback = pm_op(dev->bus->pm, state);
1367 } else if (dev->bus->suspend) {
1368 pm_dev_dbg(dev, state, "legacy bus ");
1369 error = legacy_suspend(dev, state, dev->bus->suspend,
1370 "legacy bus ");
1371 goto End;
1372 }
1373 }
1374
1375 Run:
1376 if (!callback && dev->driver && dev->driver->pm) {
1377 info = "driver ";
1378 callback = pm_op(dev->driver->pm, state);
1379 }
1380
1381 error = dpm_run_callback(callback, dev, state, info);
1382
1383 End:
1384 if (!error) {
1385 dev->power.is_suspended = true;
1386 if (dev->power.wakeup_path
1387 && dev->parent && !dev->parent->power.ignore_children)
1388 dev->parent->power.wakeup_path = true;
1389 }
1390
1391 device_unlock(dev);
1392 dpm_watchdog_clear(&wd);
1393
1394 Complete:
1395 complete_all(&dev->power.completion);
1396 if (error)
1397 async_error = error;
1398
1399 return error;
1400}
1401
1402static void async_suspend(void *data, async_cookie_t cookie)
1403{
1404 struct device *dev = (struct device *)data;
1405 int error;
1406
1407 error = __device_suspend(dev, pm_transition, true);
1408 if (error) {
1409 dpm_save_failed_dev(dev_name(dev));
1410 pm_dev_err(dev, pm_transition, " async", error);
1411 }
1412
1413 put_device(dev);
1414}
1415
1416static int device_suspend(struct device *dev)
1417{
1418 reinit_completion(&dev->power.completion);
1419
1420 if (pm_async_enabled && dev->power.async_suspend) {
1421 get_device(dev);
1422 async_schedule(async_suspend, dev);
1423 return 0;
1424 }
1425
1426 return __device_suspend(dev, pm_transition, false);
1427}
1428
1429/**
1430 * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
1431 * @state: PM transition of the system being carried out.
1432 */
1433int dpm_suspend(pm_message_t state)
1434{
1435 ktime_t starttime = ktime_get();
1436 int error = 0;
1437
1438 might_sleep();
1439
1440 cpufreq_suspend();
1441
1442 mutex_lock(&dpm_list_mtx);
1443 pm_transition = state;
1444 async_error = 0;
1445 while (!list_empty(&dpm_prepared_list)) {
1446 struct device *dev = to_device(dpm_prepared_list.prev);
1447
1448 get_device(dev);
1449 mutex_unlock(&dpm_list_mtx);
1450
1451 error = device_suspend(dev);
1452
1453 mutex_lock(&dpm_list_mtx);
1454 if (error) {
1455 pm_dev_err(dev, state, "", error);
1456 dpm_save_failed_dev(dev_name(dev));
1457 put_device(dev);
1458 break;
1459 }
1460 if (!list_empty(&dev->power.entry))
1461 list_move(&dev->power.entry, &dpm_suspended_list);
1462 put_device(dev);
1463 if (async_error)
1464 break;
1465 }
1466 mutex_unlock(&dpm_list_mtx);
1467 async_synchronize_full();
1468 if (!error)
1469 error = async_error;
1470 if (error) {
1471 suspend_stats.failed_suspend++;
1472 dpm_save_failed_step(SUSPEND_SUSPEND);
1473 } else
1474 dpm_show_time(starttime, state, NULL);
1475 return error;
1476}
1477
1478/**
1479 * device_prepare - Prepare a device for system power transition.
1480 * @dev: Device to handle.
1481 * @state: PM transition of the system being carried out.
1482 *
1483 * Execute the ->prepare() callback(s) for given device. No new children of the
1484 * device may be registered after this function has returned.
1485 */
1486static int device_prepare(struct device *dev, pm_message_t state)
1487{
1488 int (*callback)(struct device *) = NULL;
1489 char *info = NULL;
1490 int error = 0;
1491
1492 if (dev->power.syscore)
1493 return 0;
1494
1495 /*
1496 * If a device's parent goes into runtime suspend at the wrong time,
1497 * it won't be possible to resume the device. To prevent this we
1498 * block runtime suspend here, during the prepare phase, and allow
1499 * it again during the complete phase.
1500 */
1501 pm_runtime_get_noresume(dev);
1502
1503 device_lock(dev);
1504
1505 dev->power.wakeup_path = device_may_wakeup(dev);
1506
1507 if (dev->pm_domain) {
1508 info = "preparing power domain ";
1509 callback = dev->pm_domain->ops.prepare;
1510 } else if (dev->type && dev->type->pm) {
1511 info = "preparing type ";
1512 callback = dev->type->pm->prepare;
1513 } else if (dev->class && dev->class->pm) {
1514 info = "preparing class ";
1515 callback = dev->class->pm->prepare;
1516 } else if (dev->bus && dev->bus->pm) {
1517 info = "preparing bus ";
1518 callback = dev->bus->pm->prepare;
1519 }
1520
1521 if (!callback && dev->driver && dev->driver->pm) {
1522 info = "preparing driver ";
1523 callback = dev->driver->pm->prepare;
1524 }
1525
1526 if (callback) {
1527 error = callback(dev);
1528 suspend_report_result(callback, error);
1529 }
1530
1531 device_unlock(dev);
1532
1533 if (error)
1534 pm_runtime_put(dev);
1535
1536 return error;
1537}
1538
1539/**
1540 * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1541 * @state: PM transition of the system being carried out.
1542 *
1543 * Execute the ->prepare() callback(s) for all devices.
1544 */
1545int dpm_prepare(pm_message_t state)
1546{
1547 int error = 0;
1548
1549 might_sleep();
1550
1551 mutex_lock(&dpm_list_mtx);
1552 while (!list_empty(&dpm_list)) {
1553 struct device *dev = to_device(dpm_list.next);
1554
1555 get_device(dev);
1556 mutex_unlock(&dpm_list_mtx);
1557
1558 error = device_prepare(dev, state);
1559
1560 mutex_lock(&dpm_list_mtx);
1561 if (error) {
1562 if (error == -EAGAIN) {
1563 put_device(dev);
1564 error = 0;
1565 continue;
1566 }
1567 printk(KERN_INFO "PM: Device %s not prepared "
1568 "for power transition: code %d\n",
1569 dev_name(dev), error);
1570 put_device(dev);
1571 break;
1572 }
1573 dev->power.is_prepared = true;
1574 if (!list_empty(&dev->power.entry))
1575 list_move_tail(&dev->power.entry, &dpm_prepared_list);
1576 put_device(dev);
1577 }
1578 mutex_unlock(&dpm_list_mtx);
1579 return error;
1580}
1581
1582/**
1583 * dpm_suspend_start - Prepare devices for PM transition and suspend them.
1584 * @state: PM transition of the system being carried out.
1585 *
1586 * Prepare all non-sysdev devices for system PM transition and execute "suspend"
1587 * callbacks for them.
1588 */
1589int dpm_suspend_start(pm_message_t state)
1590{
1591 int error;
1592
1593 error = dpm_prepare(state);
1594 if (error) {
1595 suspend_stats.failed_prepare++;
1596 dpm_save_failed_step(SUSPEND_PREPARE);
1597 } else
1598 error = dpm_suspend(state);
1599 return error;
1600}
1601EXPORT_SYMBOL_GPL(dpm_suspend_start);
1602
1603void __suspend_report_result(const char *function, void *fn, int ret)
1604{
1605 if (ret)
1606 printk(KERN_ERR "%s(): %pF returns %d\n", function, fn, ret);
1607}
1608EXPORT_SYMBOL_GPL(__suspend_report_result);
1609
1610/**
1611 * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
1612 * @dev: Device to wait for.
1613 * @subordinate: Device that needs to wait for @dev.
1614 */
1615int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
1616{
1617 dpm_wait(dev, subordinate->power.async_suspend);
1618 return async_error;
1619}
1620EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);
1621
1622/**
1623 * dpm_for_each_dev - device iterator.
1624 * @data: data for the callback.
1625 * @fn: function to be called for each device.
1626 *
1627 * Iterate over devices in dpm_list, and call @fn for each device,
1628 * passing it @data.
1629 */
1630void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *))
1631{
1632 struct device *dev;
1633
1634 if (!fn)
1635 return;
1636
1637 device_pm_lock();
1638 list_for_each_entry(dev, &dpm_list, power.entry)
1639 fn(dev, data);
1640 device_pm_unlock();
1641}
1642EXPORT_SYMBOL_GPL(dpm_for_each_dev);