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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/pm-trace.h>
27#include <linux/pm_wakeirq.h>
28#include <linux/interrupt.h>
29#include <linux/sched.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/timer.h>
36
37#include "../base.h"
38#include "power.h"
39
40typedef int (*pm_callback_t)(struct device *);
41
42/*
43 * The entries in the dpm_list list are in a depth first order, simply
44 * because children are guaranteed to be discovered after parents, and
45 * are inserted at the back of the list on discovery.
46 *
47 * Since device_pm_add() may be called with a device lock held,
48 * we must never try to acquire a device lock while holding
49 * dpm_list_mutex.
50 */
51
52LIST_HEAD(dpm_list);
53static LIST_HEAD(dpm_prepared_list);
54static LIST_HEAD(dpm_suspended_list);
55static LIST_HEAD(dpm_late_early_list);
56static LIST_HEAD(dpm_noirq_list);
57
58struct suspend_stats suspend_stats;
59static DEFINE_MUTEX(dpm_list_mtx);
60static pm_message_t pm_transition;
61
62static int async_error;
63
64static char *pm_verb(int event)
65{
66 switch (event) {
67 case PM_EVENT_SUSPEND:
68 return "suspend";
69 case PM_EVENT_RESUME:
70 return "resume";
71 case PM_EVENT_FREEZE:
72 return "freeze";
73 case PM_EVENT_QUIESCE:
74 return "quiesce";
75 case PM_EVENT_HIBERNATE:
76 return "hibernate";
77 case PM_EVENT_THAW:
78 return "thaw";
79 case PM_EVENT_RESTORE:
80 return "restore";
81 case PM_EVENT_RECOVER:
82 return "recover";
83 default:
84 return "(unknown PM event)";
85 }
86}
87
88/**
89 * device_pm_sleep_init - Initialize system suspend-related device fields.
90 * @dev: Device object being initialized.
91 */
92void device_pm_sleep_init(struct device *dev)
93{
94 dev->power.is_prepared = false;
95 dev->power.is_suspended = false;
96 dev->power.is_noirq_suspended = false;
97 dev->power.is_late_suspended = false;
98 init_completion(&dev->power.completion);
99 complete_all(&dev->power.completion);
100 dev->power.wakeup = NULL;
101 INIT_LIST_HEAD(&dev->power.entry);
102}
103
104/**
105 * device_pm_lock - Lock the list of active devices used by the PM core.
106 */
107void device_pm_lock(void)
108{
109 mutex_lock(&dpm_list_mtx);
110}
111
112/**
113 * device_pm_unlock - Unlock the list of active devices used by the PM core.
114 */
115void device_pm_unlock(void)
116{
117 mutex_unlock(&dpm_list_mtx);
118}
119
120/**
121 * device_pm_add - Add a device to the PM core's list of active devices.
122 * @dev: Device to add to the list.
123 */
124void device_pm_add(struct device *dev)
125{
126 pr_debug("PM: Adding info for %s:%s\n",
127 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
128 device_pm_check_callbacks(dev);
129 mutex_lock(&dpm_list_mtx);
130 if (dev->parent && dev->parent->power.is_prepared)
131 dev_warn(dev, "parent %s should not be sleeping\n",
132 dev_name(dev->parent));
133 list_add_tail(&dev->power.entry, &dpm_list);
134 mutex_unlock(&dpm_list_mtx);
135}
136
137/**
138 * device_pm_remove - Remove a device from the PM core's list of active devices.
139 * @dev: Device to be removed from the list.
140 */
141void device_pm_remove(struct device *dev)
142{
143 pr_debug("PM: Removing info for %s:%s\n",
144 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
145 complete_all(&dev->power.completion);
146 mutex_lock(&dpm_list_mtx);
147 list_del_init(&dev->power.entry);
148 mutex_unlock(&dpm_list_mtx);
149 device_wakeup_disable(dev);
150 pm_runtime_remove(dev);
151 device_pm_check_callbacks(dev);
152}
153
154/**
155 * device_pm_move_before - Move device in the PM core's list of active devices.
156 * @deva: Device to move in dpm_list.
157 * @devb: Device @deva should come before.
158 */
159void device_pm_move_before(struct device *deva, struct device *devb)
160{
161 pr_debug("PM: Moving %s:%s before %s:%s\n",
162 deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
163 devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
164 /* Delete deva from dpm_list and reinsert before devb. */
165 list_move_tail(&deva->power.entry, &devb->power.entry);
166}
167
168/**
169 * device_pm_move_after - Move device in the PM core's list of active devices.
170 * @deva: Device to move in dpm_list.
171 * @devb: Device @deva should come after.
172 */
173void device_pm_move_after(struct device *deva, struct device *devb)
174{
175 pr_debug("PM: Moving %s:%s after %s:%s\n",
176 deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
177 devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
178 /* Delete deva from dpm_list and reinsert after devb. */
179 list_move(&deva->power.entry, &devb->power.entry);
180}
181
182/**
183 * device_pm_move_last - Move device to end of the PM core's list of devices.
184 * @dev: Device to move in dpm_list.
185 */
186void device_pm_move_last(struct device *dev)
187{
188 pr_debug("PM: Moving %s:%s to end of list\n",
189 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
190 list_move_tail(&dev->power.entry, &dpm_list);
191}
192
193static ktime_t initcall_debug_start(struct device *dev)
194{
195 ktime_t calltime = ktime_set(0, 0);
196
197 if (pm_print_times_enabled) {
198 pr_info("calling %s+ @ %i, parent: %s\n",
199 dev_name(dev), task_pid_nr(current),
200 dev->parent ? dev_name(dev->parent) : "none");
201 calltime = ktime_get();
202 }
203
204 return calltime;
205}
206
207static void initcall_debug_report(struct device *dev, ktime_t calltime,
208 int error, pm_message_t state, char *info)
209{
210 ktime_t rettime;
211 s64 nsecs;
212
213 rettime = ktime_get();
214 nsecs = (s64) ktime_to_ns(ktime_sub(rettime, calltime));
215
216 if (pm_print_times_enabled) {
217 pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev),
218 error, (unsigned long long)nsecs >> 10);
219 }
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 trace_device_pm_callback_start(dev, info, state.event);
391 error = cb(dev);
392 trace_device_pm_callback_end(dev, error);
393 suspend_report_result(cb, error);
394
395 initcall_debug_report(dev, calltime, error, state, info);
396
397 return error;
398}
399
400#ifdef CONFIG_DPM_WATCHDOG
401struct dpm_watchdog {
402 struct device *dev;
403 struct task_struct *tsk;
404 struct timer_list timer;
405};
406
407#define DECLARE_DPM_WATCHDOG_ON_STACK(wd) \
408 struct dpm_watchdog wd
409
410/**
411 * dpm_watchdog_handler - Driver suspend / resume watchdog handler.
412 * @data: Watchdog object address.
413 *
414 * Called when a driver has timed out suspending or resuming.
415 * There's not much we can do here to recover so panic() to
416 * capture a crash-dump in pstore.
417 */
418static void dpm_watchdog_handler(unsigned long data)
419{
420 struct dpm_watchdog *wd = (void *)data;
421
422 dev_emerg(wd->dev, "**** DPM device timeout ****\n");
423 show_stack(wd->tsk, NULL);
424 panic("%s %s: unrecoverable failure\n",
425 dev_driver_string(wd->dev), dev_name(wd->dev));
426}
427
428/**
429 * dpm_watchdog_set - Enable pm watchdog for given device.
430 * @wd: Watchdog. Must be allocated on the stack.
431 * @dev: Device to handle.
432 */
433static void dpm_watchdog_set(struct dpm_watchdog *wd, struct device *dev)
434{
435 struct timer_list *timer = &wd->timer;
436
437 wd->dev = dev;
438 wd->tsk = current;
439
440 init_timer_on_stack(timer);
441 /* use same timeout value for both suspend and resume */
442 timer->expires = jiffies + HZ * CONFIG_DPM_WATCHDOG_TIMEOUT;
443 timer->function = dpm_watchdog_handler;
444 timer->data = (unsigned long)wd;
445 add_timer(timer);
446}
447
448/**
449 * dpm_watchdog_clear - Disable suspend/resume watchdog.
450 * @wd: Watchdog to disable.
451 */
452static void dpm_watchdog_clear(struct dpm_watchdog *wd)
453{
454 struct timer_list *timer = &wd->timer;
455
456 del_timer_sync(timer);
457 destroy_timer_on_stack(timer);
458}
459#else
460#define DECLARE_DPM_WATCHDOG_ON_STACK(wd)
461#define dpm_watchdog_set(x, y)
462#define dpm_watchdog_clear(x)
463#endif
464
465/*------------------------- Resume routines -------------------------*/
466
467/**
468 * device_resume_noirq - Execute an "early resume" callback for given device.
469 * @dev: Device to handle.
470 * @state: PM transition of the system being carried out.
471 * @async: If true, the device is being resumed asynchronously.
472 *
473 * The driver of @dev will not receive interrupts while this function is being
474 * executed.
475 */
476static int device_resume_noirq(struct device *dev, pm_message_t state, bool async)
477{
478 pm_callback_t callback = NULL;
479 char *info = NULL;
480 int error = 0;
481
482 TRACE_DEVICE(dev);
483 TRACE_RESUME(0);
484
485 if (dev->power.syscore || dev->power.direct_complete)
486 goto Out;
487
488 if (!dev->power.is_noirq_suspended)
489 goto Out;
490
491 dpm_wait(dev->parent, async);
492
493 if (dev->pm_domain) {
494 info = "noirq power domain ";
495 callback = pm_noirq_op(&dev->pm_domain->ops, state);
496 } else if (dev->type && dev->type->pm) {
497 info = "noirq type ";
498 callback = pm_noirq_op(dev->type->pm, state);
499 } else if (dev->class && dev->class->pm) {
500 info = "noirq class ";
501 callback = pm_noirq_op(dev->class->pm, state);
502 } else if (dev->bus && dev->bus->pm) {
503 info = "noirq bus ";
504 callback = pm_noirq_op(dev->bus->pm, state);
505 }
506
507 if (!callback && dev->driver && dev->driver->pm) {
508 info = "noirq driver ";
509 callback = pm_noirq_op(dev->driver->pm, state);
510 }
511
512 error = dpm_run_callback(callback, dev, state, info);
513 dev->power.is_noirq_suspended = false;
514
515 Out:
516 complete_all(&dev->power.completion);
517 TRACE_RESUME(error);
518 return error;
519}
520
521static bool is_async(struct device *dev)
522{
523 return dev->power.async_suspend && pm_async_enabled
524 && !pm_trace_is_enabled();
525}
526
527static void async_resume_noirq(void *data, async_cookie_t cookie)
528{
529 struct device *dev = (struct device *)data;
530 int error;
531
532 error = device_resume_noirq(dev, pm_transition, true);
533 if (error)
534 pm_dev_err(dev, pm_transition, " async", error);
535
536 put_device(dev);
537}
538
539/**
540 * dpm_resume_noirq - Execute "noirq resume" callbacks for all devices.
541 * @state: PM transition of the system being carried out.
542 *
543 * Call the "noirq" resume handlers for all devices in dpm_noirq_list and
544 * enable device drivers to receive interrupts.
545 */
546void dpm_resume_noirq(pm_message_t state)
547{
548 struct device *dev;
549 ktime_t starttime = ktime_get();
550
551 trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, true);
552 mutex_lock(&dpm_list_mtx);
553 pm_transition = state;
554
555 /*
556 * Advanced the async threads upfront,
557 * in case the starting of async threads is
558 * delayed by non-async resuming devices.
559 */
560 list_for_each_entry(dev, &dpm_noirq_list, power.entry) {
561 reinit_completion(&dev->power.completion);
562 if (is_async(dev)) {
563 get_device(dev);
564 async_schedule(async_resume_noirq, dev);
565 }
566 }
567
568 while (!list_empty(&dpm_noirq_list)) {
569 dev = to_device(dpm_noirq_list.next);
570 get_device(dev);
571 list_move_tail(&dev->power.entry, &dpm_late_early_list);
572 mutex_unlock(&dpm_list_mtx);
573
574 if (!is_async(dev)) {
575 int error;
576
577 error = device_resume_noirq(dev, state, false);
578 if (error) {
579 suspend_stats.failed_resume_noirq++;
580 dpm_save_failed_step(SUSPEND_RESUME_NOIRQ);
581 dpm_save_failed_dev(dev_name(dev));
582 pm_dev_err(dev, state, " noirq", error);
583 }
584 }
585
586 mutex_lock(&dpm_list_mtx);
587 put_device(dev);
588 }
589 mutex_unlock(&dpm_list_mtx);
590 async_synchronize_full();
591 dpm_show_time(starttime, state, "noirq");
592 resume_device_irqs();
593 device_wakeup_disarm_wake_irqs();
594 cpuidle_resume();
595 trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, false);
596}
597
598/**
599 * device_resume_early - Execute an "early resume" callback for given device.
600 * @dev: Device to handle.
601 * @state: PM transition of the system being carried out.
602 * @async: If true, the device is being resumed asynchronously.
603 *
604 * Runtime PM is disabled for @dev while this function is being executed.
605 */
606static int device_resume_early(struct device *dev, pm_message_t state, bool async)
607{
608 pm_callback_t callback = NULL;
609 char *info = NULL;
610 int error = 0;
611
612 TRACE_DEVICE(dev);
613 TRACE_RESUME(0);
614
615 if (dev->power.syscore || dev->power.direct_complete)
616 goto Out;
617
618 if (!dev->power.is_late_suspended)
619 goto Out;
620
621 dpm_wait(dev->parent, async);
622
623 if (dev->pm_domain) {
624 info = "early power domain ";
625 callback = pm_late_early_op(&dev->pm_domain->ops, state);
626 } else if (dev->type && dev->type->pm) {
627 info = "early type ";
628 callback = pm_late_early_op(dev->type->pm, state);
629 } else if (dev->class && dev->class->pm) {
630 info = "early class ";
631 callback = pm_late_early_op(dev->class->pm, state);
632 } else if (dev->bus && dev->bus->pm) {
633 info = "early bus ";
634 callback = pm_late_early_op(dev->bus->pm, state);
635 }
636
637 if (!callback && dev->driver && dev->driver->pm) {
638 info = "early driver ";
639 callback = pm_late_early_op(dev->driver->pm, state);
640 }
641
642 error = dpm_run_callback(callback, dev, state, info);
643 dev->power.is_late_suspended = false;
644
645 Out:
646 TRACE_RESUME(error);
647
648 pm_runtime_enable(dev);
649 complete_all(&dev->power.completion);
650 return error;
651}
652
653static void async_resume_early(void *data, async_cookie_t cookie)
654{
655 struct device *dev = (struct device *)data;
656 int error;
657
658 error = device_resume_early(dev, pm_transition, true);
659 if (error)
660 pm_dev_err(dev, pm_transition, " async", error);
661
662 put_device(dev);
663}
664
665/**
666 * dpm_resume_early - Execute "early resume" callbacks for all devices.
667 * @state: PM transition of the system being carried out.
668 */
669void dpm_resume_early(pm_message_t state)
670{
671 struct device *dev;
672 ktime_t starttime = ktime_get();
673
674 trace_suspend_resume(TPS("dpm_resume_early"), state.event, true);
675 mutex_lock(&dpm_list_mtx);
676 pm_transition = state;
677
678 /*
679 * Advanced the async threads upfront,
680 * in case the starting of async threads is
681 * delayed by non-async resuming devices.
682 */
683 list_for_each_entry(dev, &dpm_late_early_list, power.entry) {
684 reinit_completion(&dev->power.completion);
685 if (is_async(dev)) {
686 get_device(dev);
687 async_schedule(async_resume_early, dev);
688 }
689 }
690
691 while (!list_empty(&dpm_late_early_list)) {
692 dev = to_device(dpm_late_early_list.next);
693 get_device(dev);
694 list_move_tail(&dev->power.entry, &dpm_suspended_list);
695 mutex_unlock(&dpm_list_mtx);
696
697 if (!is_async(dev)) {
698 int error;
699
700 error = device_resume_early(dev, state, false);
701 if (error) {
702 suspend_stats.failed_resume_early++;
703 dpm_save_failed_step(SUSPEND_RESUME_EARLY);
704 dpm_save_failed_dev(dev_name(dev));
705 pm_dev_err(dev, state, " early", error);
706 }
707 }
708 mutex_lock(&dpm_list_mtx);
709 put_device(dev);
710 }
711 mutex_unlock(&dpm_list_mtx);
712 async_synchronize_full();
713 dpm_show_time(starttime, state, "early");
714 trace_suspend_resume(TPS("dpm_resume_early"), state.event, false);
715}
716
717/**
718 * dpm_resume_start - Execute "noirq" and "early" device callbacks.
719 * @state: PM transition of the system being carried out.
720 */
721void dpm_resume_start(pm_message_t state)
722{
723 dpm_resume_noirq(state);
724 dpm_resume_early(state);
725}
726EXPORT_SYMBOL_GPL(dpm_resume_start);
727
728/**
729 * device_resume - Execute "resume" callbacks for given device.
730 * @dev: Device to handle.
731 * @state: PM transition of the system being carried out.
732 * @async: If true, the device is being resumed asynchronously.
733 */
734static int device_resume(struct device *dev, pm_message_t state, bool async)
735{
736 pm_callback_t callback = NULL;
737 char *info = NULL;
738 int error = 0;
739 DECLARE_DPM_WATCHDOG_ON_STACK(wd);
740
741 TRACE_DEVICE(dev);
742 TRACE_RESUME(0);
743
744 if (dev->power.syscore)
745 goto Complete;
746
747 if (dev->power.direct_complete) {
748 /* Match the pm_runtime_disable() in __device_suspend(). */
749 pm_runtime_enable(dev);
750 goto Complete;
751 }
752
753 dpm_wait(dev->parent, async);
754 dpm_watchdog_set(&wd, dev);
755 device_lock(dev);
756
757 /*
758 * This is a fib. But we'll allow new children to be added below
759 * a resumed device, even if the device hasn't been completed yet.
760 */
761 dev->power.is_prepared = false;
762
763 if (!dev->power.is_suspended)
764 goto Unlock;
765
766 if (dev->pm_domain) {
767 info = "power domain ";
768 callback = pm_op(&dev->pm_domain->ops, state);
769 goto Driver;
770 }
771
772 if (dev->type && dev->type->pm) {
773 info = "type ";
774 callback = pm_op(dev->type->pm, state);
775 goto Driver;
776 }
777
778 if (dev->class) {
779 if (dev->class->pm) {
780 info = "class ";
781 callback = pm_op(dev->class->pm, state);
782 goto Driver;
783 } else if (dev->class->resume) {
784 info = "legacy class ";
785 callback = dev->class->resume;
786 goto End;
787 }
788 }
789
790 if (dev->bus) {
791 if (dev->bus->pm) {
792 info = "bus ";
793 callback = pm_op(dev->bus->pm, state);
794 } else if (dev->bus->resume) {
795 info = "legacy bus ";
796 callback = dev->bus->resume;
797 goto End;
798 }
799 }
800
801 Driver:
802 if (!callback && dev->driver && dev->driver->pm) {
803 info = "driver ";
804 callback = pm_op(dev->driver->pm, state);
805 }
806
807 End:
808 error = dpm_run_callback(callback, dev, state, info);
809 dev->power.is_suspended = false;
810
811 Unlock:
812 device_unlock(dev);
813 dpm_watchdog_clear(&wd);
814
815 Complete:
816 complete_all(&dev->power.completion);
817
818 TRACE_RESUME(error);
819
820 return error;
821}
822
823static void async_resume(void *data, async_cookie_t cookie)
824{
825 struct device *dev = (struct device *)data;
826 int error;
827
828 error = device_resume(dev, pm_transition, true);
829 if (error)
830 pm_dev_err(dev, pm_transition, " async", error);
831 put_device(dev);
832}
833
834/**
835 * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
836 * @state: PM transition of the system being carried out.
837 *
838 * Execute the appropriate "resume" callback for all devices whose status
839 * indicates that they are suspended.
840 */
841void dpm_resume(pm_message_t state)
842{
843 struct device *dev;
844 ktime_t starttime = ktime_get();
845
846 trace_suspend_resume(TPS("dpm_resume"), state.event, true);
847 might_sleep();
848
849 mutex_lock(&dpm_list_mtx);
850 pm_transition = state;
851 async_error = 0;
852
853 list_for_each_entry(dev, &dpm_suspended_list, power.entry) {
854 reinit_completion(&dev->power.completion);
855 if (is_async(dev)) {
856 get_device(dev);
857 async_schedule(async_resume, dev);
858 }
859 }
860
861 while (!list_empty(&dpm_suspended_list)) {
862 dev = to_device(dpm_suspended_list.next);
863 get_device(dev);
864 if (!is_async(dev)) {
865 int error;
866
867 mutex_unlock(&dpm_list_mtx);
868
869 error = device_resume(dev, state, false);
870 if (error) {
871 suspend_stats.failed_resume++;
872 dpm_save_failed_step(SUSPEND_RESUME);
873 dpm_save_failed_dev(dev_name(dev));
874 pm_dev_err(dev, state, "", error);
875 }
876
877 mutex_lock(&dpm_list_mtx);
878 }
879 if (!list_empty(&dev->power.entry))
880 list_move_tail(&dev->power.entry, &dpm_prepared_list);
881 put_device(dev);
882 }
883 mutex_unlock(&dpm_list_mtx);
884 async_synchronize_full();
885 dpm_show_time(starttime, state, NULL);
886
887 cpufreq_resume();
888 trace_suspend_resume(TPS("dpm_resume"), state.event, false);
889}
890
891/**
892 * device_complete - Complete a PM transition for given device.
893 * @dev: Device to handle.
894 * @state: PM transition of the system being carried out.
895 */
896static void device_complete(struct device *dev, pm_message_t state)
897{
898 void (*callback)(struct device *) = NULL;
899 char *info = NULL;
900
901 if (dev->power.syscore)
902 return;
903
904 device_lock(dev);
905
906 if (dev->pm_domain) {
907 info = "completing power domain ";
908 callback = dev->pm_domain->ops.complete;
909 } else if (dev->type && dev->type->pm) {
910 info = "completing type ";
911 callback = dev->type->pm->complete;
912 } else if (dev->class && dev->class->pm) {
913 info = "completing class ";
914 callback = dev->class->pm->complete;
915 } else if (dev->bus && dev->bus->pm) {
916 info = "completing bus ";
917 callback = dev->bus->pm->complete;
918 }
919
920 if (!callback && dev->driver && dev->driver->pm) {
921 info = "completing driver ";
922 callback = dev->driver->pm->complete;
923 }
924
925 if (callback) {
926 pm_dev_dbg(dev, state, info);
927 callback(dev);
928 }
929
930 device_unlock(dev);
931
932 pm_runtime_put(dev);
933}
934
935/**
936 * dpm_complete - Complete a PM transition for all non-sysdev devices.
937 * @state: PM transition of the system being carried out.
938 *
939 * Execute the ->complete() callbacks for all devices whose PM status is not
940 * DPM_ON (this allows new devices to be registered).
941 */
942void dpm_complete(pm_message_t state)
943{
944 struct list_head list;
945
946 trace_suspend_resume(TPS("dpm_complete"), state.event, true);
947 might_sleep();
948
949 INIT_LIST_HEAD(&list);
950 mutex_lock(&dpm_list_mtx);
951 while (!list_empty(&dpm_prepared_list)) {
952 struct device *dev = to_device(dpm_prepared_list.prev);
953
954 get_device(dev);
955 dev->power.is_prepared = false;
956 list_move(&dev->power.entry, &list);
957 mutex_unlock(&dpm_list_mtx);
958
959 trace_device_pm_callback_start(dev, "", state.event);
960 device_complete(dev, state);
961 trace_device_pm_callback_end(dev, 0);
962
963 mutex_lock(&dpm_list_mtx);
964 put_device(dev);
965 }
966 list_splice(&list, &dpm_list);
967 mutex_unlock(&dpm_list_mtx);
968
969 /* Allow device probing and trigger re-probing of deferred devices */
970 device_unblock_probing();
971 trace_suspend_resume(TPS("dpm_complete"), state.event, false);
972}
973
974/**
975 * dpm_resume_end - Execute "resume" callbacks and complete system transition.
976 * @state: PM transition of the system being carried out.
977 *
978 * Execute "resume" callbacks for all devices and complete the PM transition of
979 * the system.
980 */
981void dpm_resume_end(pm_message_t state)
982{
983 dpm_resume(state);
984 dpm_complete(state);
985}
986EXPORT_SYMBOL_GPL(dpm_resume_end);
987
988
989/*------------------------- Suspend routines -------------------------*/
990
991/**
992 * resume_event - Return a "resume" message for given "suspend" sleep state.
993 * @sleep_state: PM message representing a sleep state.
994 *
995 * Return a PM message representing the resume event corresponding to given
996 * sleep state.
997 */
998static pm_message_t resume_event(pm_message_t sleep_state)
999{
1000 switch (sleep_state.event) {
1001 case PM_EVENT_SUSPEND:
1002 return PMSG_RESUME;
1003 case PM_EVENT_FREEZE:
1004 case PM_EVENT_QUIESCE:
1005 return PMSG_RECOVER;
1006 case PM_EVENT_HIBERNATE:
1007 return PMSG_RESTORE;
1008 }
1009 return PMSG_ON;
1010}
1011
1012/**
1013 * device_suspend_noirq - Execute a "late suspend" callback for given device.
1014 * @dev: Device to handle.
1015 * @state: PM transition of the system being carried out.
1016 * @async: If true, the device is being suspended asynchronously.
1017 *
1018 * The driver of @dev will not receive interrupts while this function is being
1019 * executed.
1020 */
1021static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool async)
1022{
1023 pm_callback_t callback = NULL;
1024 char *info = NULL;
1025 int error = 0;
1026
1027 TRACE_DEVICE(dev);
1028 TRACE_SUSPEND(0);
1029
1030 if (async_error)
1031 goto Complete;
1032
1033 if (pm_wakeup_pending()) {
1034 async_error = -EBUSY;
1035 goto Complete;
1036 }
1037
1038 if (dev->power.syscore || dev->power.direct_complete)
1039 goto Complete;
1040
1041 dpm_wait_for_children(dev, async);
1042
1043 if (dev->pm_domain) {
1044 info = "noirq power domain ";
1045 callback = pm_noirq_op(&dev->pm_domain->ops, state);
1046 } else if (dev->type && dev->type->pm) {
1047 info = "noirq type ";
1048 callback = pm_noirq_op(dev->type->pm, state);
1049 } else if (dev->class && dev->class->pm) {
1050 info = "noirq class ";
1051 callback = pm_noirq_op(dev->class->pm, state);
1052 } else if (dev->bus && dev->bus->pm) {
1053 info = "noirq bus ";
1054 callback = pm_noirq_op(dev->bus->pm, state);
1055 }
1056
1057 if (!callback && dev->driver && dev->driver->pm) {
1058 info = "noirq driver ";
1059 callback = pm_noirq_op(dev->driver->pm, state);
1060 }
1061
1062 error = dpm_run_callback(callback, dev, state, info);
1063 if (!error)
1064 dev->power.is_noirq_suspended = true;
1065 else
1066 async_error = error;
1067
1068Complete:
1069 complete_all(&dev->power.completion);
1070 TRACE_SUSPEND(error);
1071 return error;
1072}
1073
1074static void async_suspend_noirq(void *data, async_cookie_t cookie)
1075{
1076 struct device *dev = (struct device *)data;
1077 int error;
1078
1079 error = __device_suspend_noirq(dev, pm_transition, true);
1080 if (error) {
1081 dpm_save_failed_dev(dev_name(dev));
1082 pm_dev_err(dev, pm_transition, " async", error);
1083 }
1084
1085 put_device(dev);
1086}
1087
1088static int device_suspend_noirq(struct device *dev)
1089{
1090 reinit_completion(&dev->power.completion);
1091
1092 if (is_async(dev)) {
1093 get_device(dev);
1094 async_schedule(async_suspend_noirq, dev);
1095 return 0;
1096 }
1097 return __device_suspend_noirq(dev, pm_transition, false);
1098}
1099
1100/**
1101 * dpm_suspend_noirq - Execute "noirq suspend" callbacks for all devices.
1102 * @state: PM transition of the system being carried out.
1103 *
1104 * Prevent device drivers from receiving interrupts and call the "noirq" suspend
1105 * handlers for all non-sysdev devices.
1106 */
1107int dpm_suspend_noirq(pm_message_t state)
1108{
1109 ktime_t starttime = ktime_get();
1110 int error = 0;
1111
1112 trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, true);
1113 cpuidle_pause();
1114 device_wakeup_arm_wake_irqs();
1115 suspend_device_irqs();
1116 mutex_lock(&dpm_list_mtx);
1117 pm_transition = state;
1118 async_error = 0;
1119
1120 while (!list_empty(&dpm_late_early_list)) {
1121 struct device *dev = to_device(dpm_late_early_list.prev);
1122
1123 get_device(dev);
1124 mutex_unlock(&dpm_list_mtx);
1125
1126 error = device_suspend_noirq(dev);
1127
1128 mutex_lock(&dpm_list_mtx);
1129 if (error) {
1130 pm_dev_err(dev, state, " noirq", error);
1131 dpm_save_failed_dev(dev_name(dev));
1132 put_device(dev);
1133 break;
1134 }
1135 if (!list_empty(&dev->power.entry))
1136 list_move(&dev->power.entry, &dpm_noirq_list);
1137 put_device(dev);
1138
1139 if (async_error)
1140 break;
1141 }
1142 mutex_unlock(&dpm_list_mtx);
1143 async_synchronize_full();
1144 if (!error)
1145 error = async_error;
1146
1147 if (error) {
1148 suspend_stats.failed_suspend_noirq++;
1149 dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ);
1150 dpm_resume_noirq(resume_event(state));
1151 } else {
1152 dpm_show_time(starttime, state, "noirq");
1153 }
1154 trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, false);
1155 return error;
1156}
1157
1158/**
1159 * device_suspend_late - Execute a "late suspend" callback for given device.
1160 * @dev: Device to handle.
1161 * @state: PM transition of the system being carried out.
1162 * @async: If true, the device is being suspended asynchronously.
1163 *
1164 * Runtime PM is disabled for @dev while this function is being executed.
1165 */
1166static int __device_suspend_late(struct device *dev, pm_message_t state, bool async)
1167{
1168 pm_callback_t callback = NULL;
1169 char *info = NULL;
1170 int error = 0;
1171
1172 TRACE_DEVICE(dev);
1173 TRACE_SUSPEND(0);
1174
1175 __pm_runtime_disable(dev, false);
1176
1177 if (async_error)
1178 goto Complete;
1179
1180 if (pm_wakeup_pending()) {
1181 async_error = -EBUSY;
1182 goto Complete;
1183 }
1184
1185 if (dev->power.syscore || dev->power.direct_complete)
1186 goto Complete;
1187
1188 dpm_wait_for_children(dev, async);
1189
1190 if (dev->pm_domain) {
1191 info = "late power domain ";
1192 callback = pm_late_early_op(&dev->pm_domain->ops, state);
1193 } else if (dev->type && dev->type->pm) {
1194 info = "late type ";
1195 callback = pm_late_early_op(dev->type->pm, state);
1196 } else if (dev->class && dev->class->pm) {
1197 info = "late class ";
1198 callback = pm_late_early_op(dev->class->pm, state);
1199 } else if (dev->bus && dev->bus->pm) {
1200 info = "late bus ";
1201 callback = pm_late_early_op(dev->bus->pm, state);
1202 }
1203
1204 if (!callback && dev->driver && dev->driver->pm) {
1205 info = "late driver ";
1206 callback = pm_late_early_op(dev->driver->pm, state);
1207 }
1208
1209 error = dpm_run_callback(callback, dev, state, info);
1210 if (!error)
1211 dev->power.is_late_suspended = true;
1212 else
1213 async_error = error;
1214
1215Complete:
1216 TRACE_SUSPEND(error);
1217 complete_all(&dev->power.completion);
1218 return error;
1219}
1220
1221static void async_suspend_late(void *data, async_cookie_t cookie)
1222{
1223 struct device *dev = (struct device *)data;
1224 int error;
1225
1226 error = __device_suspend_late(dev, pm_transition, true);
1227 if (error) {
1228 dpm_save_failed_dev(dev_name(dev));
1229 pm_dev_err(dev, pm_transition, " async", error);
1230 }
1231 put_device(dev);
1232}
1233
1234static int device_suspend_late(struct device *dev)
1235{
1236 reinit_completion(&dev->power.completion);
1237
1238 if (is_async(dev)) {
1239 get_device(dev);
1240 async_schedule(async_suspend_late, dev);
1241 return 0;
1242 }
1243
1244 return __device_suspend_late(dev, pm_transition, false);
1245}
1246
1247/**
1248 * dpm_suspend_late - Execute "late suspend" callbacks for all devices.
1249 * @state: PM transition of the system being carried out.
1250 */
1251int dpm_suspend_late(pm_message_t state)
1252{
1253 ktime_t starttime = ktime_get();
1254 int error = 0;
1255
1256 trace_suspend_resume(TPS("dpm_suspend_late"), state.event, true);
1257 mutex_lock(&dpm_list_mtx);
1258 pm_transition = state;
1259 async_error = 0;
1260
1261 while (!list_empty(&dpm_suspended_list)) {
1262 struct device *dev = to_device(dpm_suspended_list.prev);
1263
1264 get_device(dev);
1265 mutex_unlock(&dpm_list_mtx);
1266
1267 error = device_suspend_late(dev);
1268
1269 mutex_lock(&dpm_list_mtx);
1270 if (error) {
1271 pm_dev_err(dev, state, " late", error);
1272 dpm_save_failed_dev(dev_name(dev));
1273 put_device(dev);
1274 break;
1275 }
1276 if (!list_empty(&dev->power.entry))
1277 list_move(&dev->power.entry, &dpm_late_early_list);
1278 put_device(dev);
1279
1280 if (async_error)
1281 break;
1282 }
1283 mutex_unlock(&dpm_list_mtx);
1284 async_synchronize_full();
1285 if (!error)
1286 error = async_error;
1287 if (error) {
1288 suspend_stats.failed_suspend_late++;
1289 dpm_save_failed_step(SUSPEND_SUSPEND_LATE);
1290 dpm_resume_early(resume_event(state));
1291 } else {
1292 dpm_show_time(starttime, state, "late");
1293 }
1294 trace_suspend_resume(TPS("dpm_suspend_late"), state.event, false);
1295 return error;
1296}
1297
1298/**
1299 * dpm_suspend_end - Execute "late" and "noirq" device suspend callbacks.
1300 * @state: PM transition of the system being carried out.
1301 */
1302int dpm_suspend_end(pm_message_t state)
1303{
1304 int error = dpm_suspend_late(state);
1305 if (error)
1306 return error;
1307
1308 error = dpm_suspend_noirq(state);
1309 if (error) {
1310 dpm_resume_early(resume_event(state));
1311 return error;
1312 }
1313
1314 return 0;
1315}
1316EXPORT_SYMBOL_GPL(dpm_suspend_end);
1317
1318/**
1319 * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
1320 * @dev: Device to suspend.
1321 * @state: PM transition of the system being carried out.
1322 * @cb: Suspend callback to execute.
1323 * @info: string description of caller.
1324 */
1325static int legacy_suspend(struct device *dev, pm_message_t state,
1326 int (*cb)(struct device *dev, pm_message_t state),
1327 char *info)
1328{
1329 int error;
1330 ktime_t calltime;
1331
1332 calltime = initcall_debug_start(dev);
1333
1334 trace_device_pm_callback_start(dev, info, state.event);
1335 error = cb(dev, state);
1336 trace_device_pm_callback_end(dev, error);
1337 suspend_report_result(cb, error);
1338
1339 initcall_debug_report(dev, calltime, error, state, info);
1340
1341 return error;
1342}
1343
1344/**
1345 * device_suspend - Execute "suspend" callbacks for given device.
1346 * @dev: Device to handle.
1347 * @state: PM transition of the system being carried out.
1348 * @async: If true, the device is being suspended asynchronously.
1349 */
1350static int __device_suspend(struct device *dev, pm_message_t state, bool async)
1351{
1352 pm_callback_t callback = NULL;
1353 char *info = NULL;
1354 int error = 0;
1355 DECLARE_DPM_WATCHDOG_ON_STACK(wd);
1356
1357 TRACE_DEVICE(dev);
1358 TRACE_SUSPEND(0);
1359
1360 dpm_wait_for_children(dev, async);
1361
1362 if (async_error)
1363 goto Complete;
1364
1365 /*
1366 * If a device configured to wake up the system from sleep states
1367 * has been suspended at run time and there's a resume request pending
1368 * for it, this is equivalent to the device signaling wakeup, so the
1369 * system suspend operation should be aborted.
1370 */
1371 if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
1372 pm_wakeup_event(dev, 0);
1373
1374 if (pm_wakeup_pending()) {
1375 async_error = -EBUSY;
1376 goto Complete;
1377 }
1378
1379 if (dev->power.syscore)
1380 goto Complete;
1381
1382 if (dev->power.direct_complete) {
1383 if (pm_runtime_status_suspended(dev)) {
1384 pm_runtime_disable(dev);
1385 if (pm_runtime_status_suspended(dev))
1386 goto Complete;
1387
1388 pm_runtime_enable(dev);
1389 }
1390 dev->power.direct_complete = false;
1391 }
1392
1393 dpm_watchdog_set(&wd, dev);
1394 device_lock(dev);
1395
1396 if (dev->pm_domain) {
1397 info = "power domain ";
1398 callback = pm_op(&dev->pm_domain->ops, state);
1399 goto Run;
1400 }
1401
1402 if (dev->type && dev->type->pm) {
1403 info = "type ";
1404 callback = pm_op(dev->type->pm, state);
1405 goto Run;
1406 }
1407
1408 if (dev->class) {
1409 if (dev->class->pm) {
1410 info = "class ";
1411 callback = pm_op(dev->class->pm, state);
1412 goto Run;
1413 } else if (dev->class->suspend) {
1414 pm_dev_dbg(dev, state, "legacy class ");
1415 error = legacy_suspend(dev, state, dev->class->suspend,
1416 "legacy class ");
1417 goto End;
1418 }
1419 }
1420
1421 if (dev->bus) {
1422 if (dev->bus->pm) {
1423 info = "bus ";
1424 callback = pm_op(dev->bus->pm, state);
1425 } else if (dev->bus->suspend) {
1426 pm_dev_dbg(dev, state, "legacy bus ");
1427 error = legacy_suspend(dev, state, dev->bus->suspend,
1428 "legacy bus ");
1429 goto End;
1430 }
1431 }
1432
1433 Run:
1434 if (!callback && dev->driver && dev->driver->pm) {
1435 info = "driver ";
1436 callback = pm_op(dev->driver->pm, state);
1437 }
1438
1439 error = dpm_run_callback(callback, dev, state, info);
1440
1441 End:
1442 if (!error) {
1443 struct device *parent = dev->parent;
1444
1445 dev->power.is_suspended = true;
1446 if (parent) {
1447 spin_lock_irq(&parent->power.lock);
1448
1449 dev->parent->power.direct_complete = false;
1450 if (dev->power.wakeup_path
1451 && !dev->parent->power.ignore_children)
1452 dev->parent->power.wakeup_path = true;
1453
1454 spin_unlock_irq(&parent->power.lock);
1455 }
1456 }
1457
1458 device_unlock(dev);
1459 dpm_watchdog_clear(&wd);
1460
1461 Complete:
1462 complete_all(&dev->power.completion);
1463 if (error)
1464 async_error = error;
1465
1466 TRACE_SUSPEND(error);
1467 return error;
1468}
1469
1470static void async_suspend(void *data, async_cookie_t cookie)
1471{
1472 struct device *dev = (struct device *)data;
1473 int error;
1474
1475 error = __device_suspend(dev, pm_transition, true);
1476 if (error) {
1477 dpm_save_failed_dev(dev_name(dev));
1478 pm_dev_err(dev, pm_transition, " async", error);
1479 }
1480
1481 put_device(dev);
1482}
1483
1484static int device_suspend(struct device *dev)
1485{
1486 reinit_completion(&dev->power.completion);
1487
1488 if (is_async(dev)) {
1489 get_device(dev);
1490 async_schedule(async_suspend, dev);
1491 return 0;
1492 }
1493
1494 return __device_suspend(dev, pm_transition, false);
1495}
1496
1497/**
1498 * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
1499 * @state: PM transition of the system being carried out.
1500 */
1501int dpm_suspend(pm_message_t state)
1502{
1503 ktime_t starttime = ktime_get();
1504 int error = 0;
1505
1506 trace_suspend_resume(TPS("dpm_suspend"), state.event, true);
1507 might_sleep();
1508
1509 cpufreq_suspend();
1510
1511 mutex_lock(&dpm_list_mtx);
1512 pm_transition = state;
1513 async_error = 0;
1514 while (!list_empty(&dpm_prepared_list)) {
1515 struct device *dev = to_device(dpm_prepared_list.prev);
1516
1517 get_device(dev);
1518 mutex_unlock(&dpm_list_mtx);
1519
1520 error = device_suspend(dev);
1521
1522 mutex_lock(&dpm_list_mtx);
1523 if (error) {
1524 pm_dev_err(dev, state, "", error);
1525 dpm_save_failed_dev(dev_name(dev));
1526 put_device(dev);
1527 break;
1528 }
1529 if (!list_empty(&dev->power.entry))
1530 list_move(&dev->power.entry, &dpm_suspended_list);
1531 put_device(dev);
1532 if (async_error)
1533 break;
1534 }
1535 mutex_unlock(&dpm_list_mtx);
1536 async_synchronize_full();
1537 if (!error)
1538 error = async_error;
1539 if (error) {
1540 suspend_stats.failed_suspend++;
1541 dpm_save_failed_step(SUSPEND_SUSPEND);
1542 } else
1543 dpm_show_time(starttime, state, NULL);
1544 trace_suspend_resume(TPS("dpm_suspend"), state.event, false);
1545 return error;
1546}
1547
1548/**
1549 * device_prepare - Prepare a device for system power transition.
1550 * @dev: Device to handle.
1551 * @state: PM transition of the system being carried out.
1552 *
1553 * Execute the ->prepare() callback(s) for given device. No new children of the
1554 * device may be registered after this function has returned.
1555 */
1556static int device_prepare(struct device *dev, pm_message_t state)
1557{
1558 int (*callback)(struct device *) = NULL;
1559 char *info = NULL;
1560 int ret = 0;
1561
1562 if (dev->power.syscore)
1563 return 0;
1564
1565 /*
1566 * If a device's parent goes into runtime suspend at the wrong time,
1567 * it won't be possible to resume the device. To prevent this we
1568 * block runtime suspend here, during the prepare phase, and allow
1569 * it again during the complete phase.
1570 */
1571 pm_runtime_get_noresume(dev);
1572
1573 device_lock(dev);
1574
1575 dev->power.wakeup_path = device_may_wakeup(dev);
1576
1577 if (dev->power.no_pm_callbacks) {
1578 ret = 1; /* Let device go direct_complete */
1579 goto unlock;
1580 }
1581
1582 if (dev->pm_domain) {
1583 info = "preparing power domain ";
1584 callback = dev->pm_domain->ops.prepare;
1585 } else if (dev->type && dev->type->pm) {
1586 info = "preparing type ";
1587 callback = dev->type->pm->prepare;
1588 } else if (dev->class && dev->class->pm) {
1589 info = "preparing class ";
1590 callback = dev->class->pm->prepare;
1591 } else if (dev->bus && dev->bus->pm) {
1592 info = "preparing bus ";
1593 callback = dev->bus->pm->prepare;
1594 }
1595
1596 if (!callback && dev->driver && dev->driver->pm) {
1597 info = "preparing driver ";
1598 callback = dev->driver->pm->prepare;
1599 }
1600
1601 if (callback)
1602 ret = callback(dev);
1603
1604unlock:
1605 device_unlock(dev);
1606
1607 if (ret < 0) {
1608 suspend_report_result(callback, ret);
1609 pm_runtime_put(dev);
1610 return ret;
1611 }
1612 /*
1613 * A positive return value from ->prepare() means "this device appears
1614 * to be runtime-suspended and its state is fine, so if it really is
1615 * runtime-suspended, you can leave it in that state provided that you
1616 * will do the same thing with all of its descendants". This only
1617 * applies to suspend transitions, however.
1618 */
1619 spin_lock_irq(&dev->power.lock);
1620 dev->power.direct_complete = ret > 0 && state.event == PM_EVENT_SUSPEND;
1621 spin_unlock_irq(&dev->power.lock);
1622 return 0;
1623}
1624
1625/**
1626 * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1627 * @state: PM transition of the system being carried out.
1628 *
1629 * Execute the ->prepare() callback(s) for all devices.
1630 */
1631int dpm_prepare(pm_message_t state)
1632{
1633 int error = 0;
1634
1635 trace_suspend_resume(TPS("dpm_prepare"), state.event, true);
1636 might_sleep();
1637
1638 /*
1639 * Give a chance for the known devices to complete their probes, before
1640 * disable probing of devices. This sync point is important at least
1641 * at boot time + hibernation restore.
1642 */
1643 wait_for_device_probe();
1644 /*
1645 * It is unsafe if probing of devices will happen during suspend or
1646 * hibernation and system behavior will be unpredictable in this case.
1647 * So, let's prohibit device's probing here and defer their probes
1648 * instead. The normal behavior will be restored in dpm_complete().
1649 */
1650 device_block_probing();
1651
1652 mutex_lock(&dpm_list_mtx);
1653 while (!list_empty(&dpm_list)) {
1654 struct device *dev = to_device(dpm_list.next);
1655
1656 get_device(dev);
1657 mutex_unlock(&dpm_list_mtx);
1658
1659 trace_device_pm_callback_start(dev, "", state.event);
1660 error = device_prepare(dev, state);
1661 trace_device_pm_callback_end(dev, error);
1662
1663 mutex_lock(&dpm_list_mtx);
1664 if (error) {
1665 if (error == -EAGAIN) {
1666 put_device(dev);
1667 error = 0;
1668 continue;
1669 }
1670 printk(KERN_INFO "PM: Device %s not prepared "
1671 "for power transition: code %d\n",
1672 dev_name(dev), error);
1673 put_device(dev);
1674 break;
1675 }
1676 dev->power.is_prepared = true;
1677 if (!list_empty(&dev->power.entry))
1678 list_move_tail(&dev->power.entry, &dpm_prepared_list);
1679 put_device(dev);
1680 }
1681 mutex_unlock(&dpm_list_mtx);
1682 trace_suspend_resume(TPS("dpm_prepare"), state.event, false);
1683 return error;
1684}
1685
1686/**
1687 * dpm_suspend_start - Prepare devices for PM transition and suspend them.
1688 * @state: PM transition of the system being carried out.
1689 *
1690 * Prepare all non-sysdev devices for system PM transition and execute "suspend"
1691 * callbacks for them.
1692 */
1693int dpm_suspend_start(pm_message_t state)
1694{
1695 int error;
1696
1697 error = dpm_prepare(state);
1698 if (error) {
1699 suspend_stats.failed_prepare++;
1700 dpm_save_failed_step(SUSPEND_PREPARE);
1701 } else
1702 error = dpm_suspend(state);
1703 return error;
1704}
1705EXPORT_SYMBOL_GPL(dpm_suspend_start);
1706
1707void __suspend_report_result(const char *function, void *fn, int ret)
1708{
1709 if (ret)
1710 printk(KERN_ERR "%s(): %pF returns %d\n", function, fn, ret);
1711}
1712EXPORT_SYMBOL_GPL(__suspend_report_result);
1713
1714/**
1715 * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
1716 * @dev: Device to wait for.
1717 * @subordinate: Device that needs to wait for @dev.
1718 */
1719int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
1720{
1721 dpm_wait(dev, subordinate->power.async_suspend);
1722 return async_error;
1723}
1724EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);
1725
1726/**
1727 * dpm_for_each_dev - device iterator.
1728 * @data: data for the callback.
1729 * @fn: function to be called for each device.
1730 *
1731 * Iterate over devices in dpm_list, and call @fn for each device,
1732 * passing it @data.
1733 */
1734void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *))
1735{
1736 struct device *dev;
1737
1738 if (!fn)
1739 return;
1740
1741 device_pm_lock();
1742 list_for_each_entry(dev, &dpm_list, power.entry)
1743 fn(dev, data);
1744 device_pm_unlock();
1745}
1746EXPORT_SYMBOL_GPL(dpm_for_each_dev);
1747
1748static bool pm_ops_is_empty(const struct dev_pm_ops *ops)
1749{
1750 if (!ops)
1751 return true;
1752
1753 return !ops->prepare &&
1754 !ops->suspend &&
1755 !ops->suspend_late &&
1756 !ops->suspend_noirq &&
1757 !ops->resume_noirq &&
1758 !ops->resume_early &&
1759 !ops->resume &&
1760 !ops->complete;
1761}
1762
1763void device_pm_check_callbacks(struct device *dev)
1764{
1765 spin_lock_irq(&dev->power.lock);
1766 dev->power.no_pm_callbacks =
1767 (!dev->bus || pm_ops_is_empty(dev->bus->pm)) &&
1768 (!dev->class || pm_ops_is_empty(dev->class->pm)) &&
1769 (!dev->type || pm_ops_is_empty(dev->type->pm)) &&
1770 (!dev->pm_domain || pm_ops_is_empty(&dev->pm_domain->ops)) &&
1771 (!dev->driver || pm_ops_is_empty(dev->driver->pm));
1772 spin_unlock_irq(&dev->power.lock);
1773}