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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/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}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * drivers/base/power/main.c - Where the driver meets power management.
4 *
5 * Copyright (c) 2003 Patrick Mochel
6 * Copyright (c) 2003 Open Source Development Lab
7 *
8 * The driver model core calls device_pm_add() when a device is registered.
9 * This will initialize the embedded device_pm_info object in the device
10 * and add it to the list of power-controlled devices. sysfs entries for
11 * controlling device power management will also be added.
12 *
13 * A separate list is used for keeping track of power info, because the power
14 * domain dependencies may differ from the ancestral dependencies that the
15 * subsystem list maintains.
16 */
17
18#define pr_fmt(fmt) "PM: " fmt
19
20#include <linux/device.h>
21#include <linux/export.h>
22#include <linux/mutex.h>
23#include <linux/pm.h>
24#include <linux/pm_runtime.h>
25#include <linux/pm-trace.h>
26#include <linux/pm_wakeirq.h>
27#include <linux/interrupt.h>
28#include <linux/sched.h>
29#include <linux/sched/debug.h>
30#include <linux/async.h>
31#include <linux/suspend.h>
32#include <trace/events/power.h>
33#include <linux/cpufreq.h>
34#include <linux/cpuidle.h>
35#include <linux/devfreq.h>
36#include <linux/timer.h>
37
38#include "../base.h"
39#include "power.h"
40
41typedef int (*pm_callback_t)(struct device *);
42
43/*
44 * The entries in the dpm_list list are in a depth first order, simply
45 * because children are guaranteed to be discovered after parents, and
46 * are inserted at the back of the list on discovery.
47 *
48 * Since device_pm_add() may be called with a device lock held,
49 * we must never try to acquire a device lock while holding
50 * dpm_list_mutex.
51 */
52
53LIST_HEAD(dpm_list);
54static LIST_HEAD(dpm_prepared_list);
55static LIST_HEAD(dpm_suspended_list);
56static LIST_HEAD(dpm_late_early_list);
57static LIST_HEAD(dpm_noirq_list);
58
59struct suspend_stats suspend_stats;
60static DEFINE_MUTEX(dpm_list_mtx);
61static pm_message_t pm_transition;
62
63static int async_error;
64
65static const char *pm_verb(int event)
66{
67 switch (event) {
68 case PM_EVENT_SUSPEND:
69 return "suspend";
70 case PM_EVENT_RESUME:
71 return "resume";
72 case PM_EVENT_FREEZE:
73 return "freeze";
74 case PM_EVENT_QUIESCE:
75 return "quiesce";
76 case PM_EVENT_HIBERNATE:
77 return "hibernate";
78 case PM_EVENT_THAW:
79 return "thaw";
80 case PM_EVENT_RESTORE:
81 return "restore";
82 case PM_EVENT_RECOVER:
83 return "recover";
84 default:
85 return "(unknown PM event)";
86 }
87}
88
89/**
90 * device_pm_sleep_init - Initialize system suspend-related device fields.
91 * @dev: Device object being initialized.
92 */
93void device_pm_sleep_init(struct device *dev)
94{
95 dev->power.is_prepared = false;
96 dev->power.is_suspended = false;
97 dev->power.is_noirq_suspended = false;
98 dev->power.is_late_suspended = false;
99 init_completion(&dev->power.completion);
100 complete_all(&dev->power.completion);
101 dev->power.wakeup = NULL;
102 INIT_LIST_HEAD(&dev->power.entry);
103}
104
105/**
106 * device_pm_lock - Lock the list of active devices used by the PM core.
107 */
108void device_pm_lock(void)
109{
110 mutex_lock(&dpm_list_mtx);
111}
112
113/**
114 * device_pm_unlock - Unlock the list of active devices used by the PM core.
115 */
116void device_pm_unlock(void)
117{
118 mutex_unlock(&dpm_list_mtx);
119}
120
121/**
122 * device_pm_add - Add a device to the PM core's list of active devices.
123 * @dev: Device to add to the list.
124 */
125void device_pm_add(struct device *dev)
126{
127 /* Skip PM setup/initialization. */
128 if (device_pm_not_required(dev))
129 return;
130
131 pr_debug("Adding info for %s:%s\n",
132 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
133 device_pm_check_callbacks(dev);
134 mutex_lock(&dpm_list_mtx);
135 if (dev->parent && dev->parent->power.is_prepared)
136 dev_warn(dev, "parent %s should not be sleeping\n",
137 dev_name(dev->parent));
138 list_add_tail(&dev->power.entry, &dpm_list);
139 dev->power.in_dpm_list = true;
140 mutex_unlock(&dpm_list_mtx);
141}
142
143/**
144 * device_pm_remove - Remove a device from the PM core's list of active devices.
145 * @dev: Device to be removed from the list.
146 */
147void device_pm_remove(struct device *dev)
148{
149 if (device_pm_not_required(dev))
150 return;
151
152 pr_debug("Removing info for %s:%s\n",
153 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
154 complete_all(&dev->power.completion);
155 mutex_lock(&dpm_list_mtx);
156 list_del_init(&dev->power.entry);
157 dev->power.in_dpm_list = false;
158 mutex_unlock(&dpm_list_mtx);
159 device_wakeup_disable(dev);
160 pm_runtime_remove(dev);
161 device_pm_check_callbacks(dev);
162}
163
164/**
165 * device_pm_move_before - Move device in the PM core's list of active devices.
166 * @deva: Device to move in dpm_list.
167 * @devb: Device @deva should come before.
168 */
169void device_pm_move_before(struct device *deva, struct device *devb)
170{
171 pr_debug("Moving %s:%s before %s:%s\n",
172 deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
173 devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
174 /* Delete deva from dpm_list and reinsert before devb. */
175 list_move_tail(&deva->power.entry, &devb->power.entry);
176}
177
178/**
179 * device_pm_move_after - Move device in the PM core's list of active devices.
180 * @deva: Device to move in dpm_list.
181 * @devb: Device @deva should come after.
182 */
183void device_pm_move_after(struct device *deva, struct device *devb)
184{
185 pr_debug("Moving %s:%s after %s:%s\n",
186 deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
187 devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
188 /* Delete deva from dpm_list and reinsert after devb. */
189 list_move(&deva->power.entry, &devb->power.entry);
190}
191
192/**
193 * device_pm_move_last - Move device to end of the PM core's list of devices.
194 * @dev: Device to move in dpm_list.
195 */
196void device_pm_move_last(struct device *dev)
197{
198 pr_debug("Moving %s:%s to end of list\n",
199 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
200 list_move_tail(&dev->power.entry, &dpm_list);
201}
202
203static ktime_t initcall_debug_start(struct device *dev, void *cb)
204{
205 if (!pm_print_times_enabled)
206 return 0;
207
208 dev_info(dev, "calling %pS @ %i, parent: %s\n", cb,
209 task_pid_nr(current),
210 dev->parent ? dev_name(dev->parent) : "none");
211 return ktime_get();
212}
213
214static void initcall_debug_report(struct device *dev, ktime_t calltime,
215 void *cb, int error)
216{
217 ktime_t rettime;
218 s64 nsecs;
219
220 if (!pm_print_times_enabled)
221 return;
222
223 rettime = ktime_get();
224 nsecs = (s64) ktime_to_ns(ktime_sub(rettime, calltime));
225
226 dev_info(dev, "%pS returned %d after %Ld usecs\n", cb, error,
227 (unsigned long long)nsecs >> 10);
228}
229
230/**
231 * dpm_wait - Wait for a PM operation to complete.
232 * @dev: Device to wait for.
233 * @async: If unset, wait only if the device's power.async_suspend flag is set.
234 */
235static void dpm_wait(struct device *dev, bool async)
236{
237 if (!dev)
238 return;
239
240 if (async || (pm_async_enabled && dev->power.async_suspend))
241 wait_for_completion(&dev->power.completion);
242}
243
244static int dpm_wait_fn(struct device *dev, void *async_ptr)
245{
246 dpm_wait(dev, *((bool *)async_ptr));
247 return 0;
248}
249
250static void dpm_wait_for_children(struct device *dev, bool async)
251{
252 device_for_each_child(dev, &async, dpm_wait_fn);
253}
254
255static void dpm_wait_for_suppliers(struct device *dev, bool async)
256{
257 struct device_link *link;
258 int idx;
259
260 idx = device_links_read_lock();
261
262 /*
263 * If the supplier goes away right after we've checked the link to it,
264 * we'll wait for its completion to change the state, but that's fine,
265 * because the only things that will block as a result are the SRCU
266 * callbacks freeing the link objects for the links in the list we're
267 * walking.
268 */
269 list_for_each_entry_rcu(link, &dev->links.suppliers, c_node)
270 if (READ_ONCE(link->status) != DL_STATE_DORMANT)
271 dpm_wait(link->supplier, async);
272
273 device_links_read_unlock(idx);
274}
275
276static void dpm_wait_for_superior(struct device *dev, bool async)
277{
278 dpm_wait(dev->parent, async);
279 dpm_wait_for_suppliers(dev, async);
280}
281
282static void dpm_wait_for_consumers(struct device *dev, bool async)
283{
284 struct device_link *link;
285 int idx;
286
287 idx = device_links_read_lock();
288
289 /*
290 * The status of a device link can only be changed from "dormant" by a
291 * probe, but that cannot happen during system suspend/resume. In
292 * theory it can change to "dormant" at that time, but then it is
293 * reasonable to wait for the target device anyway (eg. if it goes
294 * away, it's better to wait for it to go away completely and then
295 * continue instead of trying to continue in parallel with its
296 * unregistration).
297 */
298 list_for_each_entry_rcu(link, &dev->links.consumers, s_node)
299 if (READ_ONCE(link->status) != DL_STATE_DORMANT)
300 dpm_wait(link->consumer, async);
301
302 device_links_read_unlock(idx);
303}
304
305static void dpm_wait_for_subordinate(struct device *dev, bool async)
306{
307 dpm_wait_for_children(dev, async);
308 dpm_wait_for_consumers(dev, async);
309}
310
311/**
312 * pm_op - Return the PM operation appropriate for given PM event.
313 * @ops: PM operations to choose from.
314 * @state: PM transition of the system being carried out.
315 */
316static pm_callback_t pm_op(const struct dev_pm_ops *ops, pm_message_t state)
317{
318 switch (state.event) {
319#ifdef CONFIG_SUSPEND
320 case PM_EVENT_SUSPEND:
321 return ops->suspend;
322 case PM_EVENT_RESUME:
323 return ops->resume;
324#endif /* CONFIG_SUSPEND */
325#ifdef CONFIG_HIBERNATE_CALLBACKS
326 case PM_EVENT_FREEZE:
327 case PM_EVENT_QUIESCE:
328 return ops->freeze;
329 case PM_EVENT_HIBERNATE:
330 return ops->poweroff;
331 case PM_EVENT_THAW:
332 case PM_EVENT_RECOVER:
333 return ops->thaw;
334 break;
335 case PM_EVENT_RESTORE:
336 return ops->restore;
337#endif /* CONFIG_HIBERNATE_CALLBACKS */
338 }
339
340 return NULL;
341}
342
343/**
344 * pm_late_early_op - Return the PM operation appropriate for given PM event.
345 * @ops: PM operations to choose from.
346 * @state: PM transition of the system being carried out.
347 *
348 * Runtime PM is disabled for @dev while this function is being executed.
349 */
350static pm_callback_t pm_late_early_op(const struct dev_pm_ops *ops,
351 pm_message_t state)
352{
353 switch (state.event) {
354#ifdef CONFIG_SUSPEND
355 case PM_EVENT_SUSPEND:
356 return ops->suspend_late;
357 case PM_EVENT_RESUME:
358 return ops->resume_early;
359#endif /* CONFIG_SUSPEND */
360#ifdef CONFIG_HIBERNATE_CALLBACKS
361 case PM_EVENT_FREEZE:
362 case PM_EVENT_QUIESCE:
363 return ops->freeze_late;
364 case PM_EVENT_HIBERNATE:
365 return ops->poweroff_late;
366 case PM_EVENT_THAW:
367 case PM_EVENT_RECOVER:
368 return ops->thaw_early;
369 case PM_EVENT_RESTORE:
370 return ops->restore_early;
371#endif /* CONFIG_HIBERNATE_CALLBACKS */
372 }
373
374 return NULL;
375}
376
377/**
378 * pm_noirq_op - Return the PM operation appropriate for given PM event.
379 * @ops: PM operations to choose from.
380 * @state: PM transition of the system being carried out.
381 *
382 * The driver of @dev will not receive interrupts while this function is being
383 * executed.
384 */
385static pm_callback_t pm_noirq_op(const struct dev_pm_ops *ops, pm_message_t state)
386{
387 switch (state.event) {
388#ifdef CONFIG_SUSPEND
389 case PM_EVENT_SUSPEND:
390 return ops->suspend_noirq;
391 case PM_EVENT_RESUME:
392 return ops->resume_noirq;
393#endif /* CONFIG_SUSPEND */
394#ifdef CONFIG_HIBERNATE_CALLBACKS
395 case PM_EVENT_FREEZE:
396 case PM_EVENT_QUIESCE:
397 return ops->freeze_noirq;
398 case PM_EVENT_HIBERNATE:
399 return ops->poweroff_noirq;
400 case PM_EVENT_THAW:
401 case PM_EVENT_RECOVER:
402 return ops->thaw_noirq;
403 case PM_EVENT_RESTORE:
404 return ops->restore_noirq;
405#endif /* CONFIG_HIBERNATE_CALLBACKS */
406 }
407
408 return NULL;
409}
410
411static void pm_dev_dbg(struct device *dev, pm_message_t state, const char *info)
412{
413 dev_dbg(dev, "%s%s%s\n", info, pm_verb(state.event),
414 ((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
415 ", may wakeup" : "");
416}
417
418static void pm_dev_err(struct device *dev, pm_message_t state, const char *info,
419 int error)
420{
421 pr_err("Device %s failed to %s%s: error %d\n",
422 dev_name(dev), pm_verb(state.event), info, error);
423}
424
425static void dpm_show_time(ktime_t starttime, pm_message_t state, int error,
426 const char *info)
427{
428 ktime_t calltime;
429 u64 usecs64;
430 int usecs;
431
432 calltime = ktime_get();
433 usecs64 = ktime_to_ns(ktime_sub(calltime, starttime));
434 do_div(usecs64, NSEC_PER_USEC);
435 usecs = usecs64;
436 if (usecs == 0)
437 usecs = 1;
438
439 pm_pr_dbg("%s%s%s of devices %s after %ld.%03ld msecs\n",
440 info ?: "", info ? " " : "", pm_verb(state.event),
441 error ? "aborted" : "complete",
442 usecs / USEC_PER_MSEC, usecs % USEC_PER_MSEC);
443}
444
445static int dpm_run_callback(pm_callback_t cb, struct device *dev,
446 pm_message_t state, const char *info)
447{
448 ktime_t calltime;
449 int error;
450
451 if (!cb)
452 return 0;
453
454 calltime = initcall_debug_start(dev, cb);
455
456 pm_dev_dbg(dev, state, info);
457 trace_device_pm_callback_start(dev, info, state.event);
458 error = cb(dev);
459 trace_device_pm_callback_end(dev, error);
460 suspend_report_result(cb, error);
461
462 initcall_debug_report(dev, calltime, cb, error);
463
464 return error;
465}
466
467#ifdef CONFIG_DPM_WATCHDOG
468struct dpm_watchdog {
469 struct device *dev;
470 struct task_struct *tsk;
471 struct timer_list timer;
472};
473
474#define DECLARE_DPM_WATCHDOG_ON_STACK(wd) \
475 struct dpm_watchdog wd
476
477/**
478 * dpm_watchdog_handler - Driver suspend / resume watchdog handler.
479 * @t: The timer that PM watchdog depends on.
480 *
481 * Called when a driver has timed out suspending or resuming.
482 * There's not much we can do here to recover so panic() to
483 * capture a crash-dump in pstore.
484 */
485static void dpm_watchdog_handler(struct timer_list *t)
486{
487 struct dpm_watchdog *wd = from_timer(wd, t, timer);
488
489 dev_emerg(wd->dev, "**** DPM device timeout ****\n");
490 show_stack(wd->tsk, NULL);
491 panic("%s %s: unrecoverable failure\n",
492 dev_driver_string(wd->dev), dev_name(wd->dev));
493}
494
495/**
496 * dpm_watchdog_set - Enable pm watchdog for given device.
497 * @wd: Watchdog. Must be allocated on the stack.
498 * @dev: Device to handle.
499 */
500static void dpm_watchdog_set(struct dpm_watchdog *wd, struct device *dev)
501{
502 struct timer_list *timer = &wd->timer;
503
504 wd->dev = dev;
505 wd->tsk = current;
506
507 timer_setup_on_stack(timer, dpm_watchdog_handler, 0);
508 /* use same timeout value for both suspend and resume */
509 timer->expires = jiffies + HZ * CONFIG_DPM_WATCHDOG_TIMEOUT;
510 add_timer(timer);
511}
512
513/**
514 * dpm_watchdog_clear - Disable suspend/resume watchdog.
515 * @wd: Watchdog to disable.
516 */
517static void dpm_watchdog_clear(struct dpm_watchdog *wd)
518{
519 struct timer_list *timer = &wd->timer;
520
521 del_timer_sync(timer);
522 destroy_timer_on_stack(timer);
523}
524#else
525#define DECLARE_DPM_WATCHDOG_ON_STACK(wd)
526#define dpm_watchdog_set(x, y)
527#define dpm_watchdog_clear(x)
528#endif
529
530/*------------------------- Resume routines -------------------------*/
531
532/**
533 * suspend_event - Return a "suspend" message for given "resume" one.
534 * @resume_msg: PM message representing a system-wide resume transition.
535 */
536static pm_message_t suspend_event(pm_message_t resume_msg)
537{
538 switch (resume_msg.event) {
539 case PM_EVENT_RESUME:
540 return PMSG_SUSPEND;
541 case PM_EVENT_THAW:
542 case PM_EVENT_RESTORE:
543 return PMSG_FREEZE;
544 case PM_EVENT_RECOVER:
545 return PMSG_HIBERNATE;
546 }
547 return PMSG_ON;
548}
549
550/**
551 * dev_pm_may_skip_resume - System-wide device resume optimization check.
552 * @dev: Target device.
553 *
554 * Checks whether or not the device may be left in suspend after a system-wide
555 * transition to the working state.
556 */
557bool dev_pm_may_skip_resume(struct device *dev)
558{
559 return !dev->power.must_resume && pm_transition.event != PM_EVENT_RESTORE;
560}
561
562static pm_callback_t dpm_subsys_resume_noirq_cb(struct device *dev,
563 pm_message_t state,
564 const char **info_p)
565{
566 pm_callback_t callback;
567 const char *info;
568
569 if (dev->pm_domain) {
570 info = "noirq power domain ";
571 callback = pm_noirq_op(&dev->pm_domain->ops, state);
572 } else if (dev->type && dev->type->pm) {
573 info = "noirq type ";
574 callback = pm_noirq_op(dev->type->pm, state);
575 } else if (dev->class && dev->class->pm) {
576 info = "noirq class ";
577 callback = pm_noirq_op(dev->class->pm, state);
578 } else if (dev->bus && dev->bus->pm) {
579 info = "noirq bus ";
580 callback = pm_noirq_op(dev->bus->pm, state);
581 } else {
582 return NULL;
583 }
584
585 if (info_p)
586 *info_p = info;
587
588 return callback;
589}
590
591static pm_callback_t dpm_subsys_suspend_noirq_cb(struct device *dev,
592 pm_message_t state,
593 const char **info_p);
594
595static pm_callback_t dpm_subsys_suspend_late_cb(struct device *dev,
596 pm_message_t state,
597 const char **info_p);
598
599/**
600 * device_resume_noirq - Execute a "noirq resume" callback for given device.
601 * @dev: Device to handle.
602 * @state: PM transition of the system being carried out.
603 * @async: If true, the device is being resumed asynchronously.
604 *
605 * The driver of @dev will not receive interrupts while this function is being
606 * executed.
607 */
608static int device_resume_noirq(struct device *dev, pm_message_t state, bool async)
609{
610 pm_callback_t callback;
611 const char *info;
612 bool skip_resume;
613 int error = 0;
614
615 TRACE_DEVICE(dev);
616 TRACE_RESUME(0);
617
618 if (dev->power.syscore || dev->power.direct_complete)
619 goto Out;
620
621 if (!dev->power.is_noirq_suspended)
622 goto Out;
623
624 dpm_wait_for_superior(dev, async);
625
626 skip_resume = dev_pm_may_skip_resume(dev);
627
628 callback = dpm_subsys_resume_noirq_cb(dev, state, &info);
629 if (callback)
630 goto Run;
631
632 if (skip_resume)
633 goto Skip;
634
635 if (dev_pm_smart_suspend_and_suspended(dev)) {
636 pm_message_t suspend_msg = suspend_event(state);
637
638 /*
639 * If "freeze" callbacks have been skipped during a transition
640 * related to hibernation, the subsequent "thaw" callbacks must
641 * be skipped too or bad things may happen. Otherwise, resume
642 * callbacks are going to be run for the device, so its runtime
643 * PM status must be changed to reflect the new state after the
644 * transition under way.
645 */
646 if (!dpm_subsys_suspend_late_cb(dev, suspend_msg, NULL) &&
647 !dpm_subsys_suspend_noirq_cb(dev, suspend_msg, NULL)) {
648 if (state.event == PM_EVENT_THAW) {
649 skip_resume = true;
650 goto Skip;
651 } else {
652 pm_runtime_set_active(dev);
653 }
654 }
655 }
656
657 if (dev->driver && dev->driver->pm) {
658 info = "noirq driver ";
659 callback = pm_noirq_op(dev->driver->pm, state);
660 }
661
662Run:
663 error = dpm_run_callback(callback, dev, state, info);
664
665Skip:
666 dev->power.is_noirq_suspended = false;
667
668 if (skip_resume) {
669 /* Make the next phases of resume skip the device. */
670 dev->power.is_late_suspended = false;
671 dev->power.is_suspended = false;
672 /*
673 * The device is going to be left in suspend, but it might not
674 * have been in runtime suspend before the system suspended, so
675 * its runtime PM status needs to be updated to avoid confusing
676 * the runtime PM framework when runtime PM is enabled for the
677 * device again.
678 */
679 pm_runtime_set_suspended(dev);
680 }
681
682Out:
683 complete_all(&dev->power.completion);
684 TRACE_RESUME(error);
685 return error;
686}
687
688static bool is_async(struct device *dev)
689{
690 return dev->power.async_suspend && pm_async_enabled
691 && !pm_trace_is_enabled();
692}
693
694static bool dpm_async_fn(struct device *dev, async_func_t func)
695{
696 reinit_completion(&dev->power.completion);
697
698 if (is_async(dev)) {
699 get_device(dev);
700 async_schedule(func, dev);
701 return true;
702 }
703
704 return false;
705}
706
707static void async_resume_noirq(void *data, async_cookie_t cookie)
708{
709 struct device *dev = (struct device *)data;
710 int error;
711
712 error = device_resume_noirq(dev, pm_transition, true);
713 if (error)
714 pm_dev_err(dev, pm_transition, " async", error);
715
716 put_device(dev);
717}
718
719static void dpm_noirq_resume_devices(pm_message_t state)
720{
721 struct device *dev;
722 ktime_t starttime = ktime_get();
723
724 trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, true);
725 mutex_lock(&dpm_list_mtx);
726 pm_transition = state;
727
728 /*
729 * Advanced the async threads upfront,
730 * in case the starting of async threads is
731 * delayed by non-async resuming devices.
732 */
733 list_for_each_entry(dev, &dpm_noirq_list, power.entry)
734 dpm_async_fn(dev, async_resume_noirq);
735
736 while (!list_empty(&dpm_noirq_list)) {
737 dev = to_device(dpm_noirq_list.next);
738 get_device(dev);
739 list_move_tail(&dev->power.entry, &dpm_late_early_list);
740 mutex_unlock(&dpm_list_mtx);
741
742 if (!is_async(dev)) {
743 int error;
744
745 error = device_resume_noirq(dev, state, false);
746 if (error) {
747 suspend_stats.failed_resume_noirq++;
748 dpm_save_failed_step(SUSPEND_RESUME_NOIRQ);
749 dpm_save_failed_dev(dev_name(dev));
750 pm_dev_err(dev, state, " noirq", error);
751 }
752 }
753
754 mutex_lock(&dpm_list_mtx);
755 put_device(dev);
756 }
757 mutex_unlock(&dpm_list_mtx);
758 async_synchronize_full();
759 dpm_show_time(starttime, state, 0, "noirq");
760 trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, false);
761}
762
763/**
764 * dpm_resume_noirq - Execute "noirq resume" callbacks for all devices.
765 * @state: PM transition of the system being carried out.
766 *
767 * Invoke the "noirq" resume callbacks for all devices in dpm_noirq_list and
768 * allow device drivers' interrupt handlers to be called.
769 */
770void dpm_resume_noirq(pm_message_t state)
771{
772 dpm_noirq_resume_devices(state);
773
774 resume_device_irqs();
775 device_wakeup_disarm_wake_irqs();
776
777 cpuidle_resume();
778}
779
780static pm_callback_t dpm_subsys_resume_early_cb(struct device *dev,
781 pm_message_t state,
782 const char **info_p)
783{
784 pm_callback_t callback;
785 const char *info;
786
787 if (dev->pm_domain) {
788 info = "early power domain ";
789 callback = pm_late_early_op(&dev->pm_domain->ops, state);
790 } else if (dev->type && dev->type->pm) {
791 info = "early type ";
792 callback = pm_late_early_op(dev->type->pm, state);
793 } else if (dev->class && dev->class->pm) {
794 info = "early class ";
795 callback = pm_late_early_op(dev->class->pm, state);
796 } else if (dev->bus && dev->bus->pm) {
797 info = "early bus ";
798 callback = pm_late_early_op(dev->bus->pm, state);
799 } else {
800 return NULL;
801 }
802
803 if (info_p)
804 *info_p = info;
805
806 return callback;
807}
808
809/**
810 * device_resume_early - Execute an "early resume" callback for given device.
811 * @dev: Device to handle.
812 * @state: PM transition of the system being carried out.
813 * @async: If true, the device is being resumed asynchronously.
814 *
815 * Runtime PM is disabled for @dev while this function is being executed.
816 */
817static int device_resume_early(struct device *dev, pm_message_t state, bool async)
818{
819 pm_callback_t callback;
820 const char *info;
821 int error = 0;
822
823 TRACE_DEVICE(dev);
824 TRACE_RESUME(0);
825
826 if (dev->power.syscore || dev->power.direct_complete)
827 goto Out;
828
829 if (!dev->power.is_late_suspended)
830 goto Out;
831
832 dpm_wait_for_superior(dev, async);
833
834 callback = dpm_subsys_resume_early_cb(dev, state, &info);
835
836 if (!callback && dev->driver && dev->driver->pm) {
837 info = "early driver ";
838 callback = pm_late_early_op(dev->driver->pm, state);
839 }
840
841 error = dpm_run_callback(callback, dev, state, info);
842 dev->power.is_late_suspended = false;
843
844 Out:
845 TRACE_RESUME(error);
846
847 pm_runtime_enable(dev);
848 complete_all(&dev->power.completion);
849 return error;
850}
851
852static void async_resume_early(void *data, async_cookie_t cookie)
853{
854 struct device *dev = (struct device *)data;
855 int error;
856
857 error = device_resume_early(dev, pm_transition, true);
858 if (error)
859 pm_dev_err(dev, pm_transition, " async", error);
860
861 put_device(dev);
862}
863
864/**
865 * dpm_resume_early - Execute "early resume" callbacks for all devices.
866 * @state: PM transition of the system being carried out.
867 */
868void dpm_resume_early(pm_message_t state)
869{
870 struct device *dev;
871 ktime_t starttime = ktime_get();
872
873 trace_suspend_resume(TPS("dpm_resume_early"), state.event, true);
874 mutex_lock(&dpm_list_mtx);
875 pm_transition = state;
876
877 /*
878 * Advanced the async threads upfront,
879 * in case the starting of async threads is
880 * delayed by non-async resuming devices.
881 */
882 list_for_each_entry(dev, &dpm_late_early_list, power.entry)
883 dpm_async_fn(dev, async_resume_early);
884
885 while (!list_empty(&dpm_late_early_list)) {
886 dev = to_device(dpm_late_early_list.next);
887 get_device(dev);
888 list_move_tail(&dev->power.entry, &dpm_suspended_list);
889 mutex_unlock(&dpm_list_mtx);
890
891 if (!is_async(dev)) {
892 int error;
893
894 error = device_resume_early(dev, state, false);
895 if (error) {
896 suspend_stats.failed_resume_early++;
897 dpm_save_failed_step(SUSPEND_RESUME_EARLY);
898 dpm_save_failed_dev(dev_name(dev));
899 pm_dev_err(dev, state, " early", error);
900 }
901 }
902 mutex_lock(&dpm_list_mtx);
903 put_device(dev);
904 }
905 mutex_unlock(&dpm_list_mtx);
906 async_synchronize_full();
907 dpm_show_time(starttime, state, 0, "early");
908 trace_suspend_resume(TPS("dpm_resume_early"), state.event, false);
909}
910
911/**
912 * dpm_resume_start - Execute "noirq" and "early" device callbacks.
913 * @state: PM transition of the system being carried out.
914 */
915void dpm_resume_start(pm_message_t state)
916{
917 dpm_resume_noirq(state);
918 dpm_resume_early(state);
919}
920EXPORT_SYMBOL_GPL(dpm_resume_start);
921
922/**
923 * device_resume - Execute "resume" callbacks for given device.
924 * @dev: Device to handle.
925 * @state: PM transition of the system being carried out.
926 * @async: If true, the device is being resumed asynchronously.
927 */
928static int device_resume(struct device *dev, pm_message_t state, bool async)
929{
930 pm_callback_t callback = NULL;
931 const char *info = NULL;
932 int error = 0;
933 DECLARE_DPM_WATCHDOG_ON_STACK(wd);
934
935 TRACE_DEVICE(dev);
936 TRACE_RESUME(0);
937
938 if (dev->power.syscore)
939 goto Complete;
940
941 if (dev->power.direct_complete) {
942 /* Match the pm_runtime_disable() in __device_suspend(). */
943 pm_runtime_enable(dev);
944 goto Complete;
945 }
946
947 dpm_wait_for_superior(dev, async);
948 dpm_watchdog_set(&wd, dev);
949 device_lock(dev);
950
951 /*
952 * This is a fib. But we'll allow new children to be added below
953 * a resumed device, even if the device hasn't been completed yet.
954 */
955 dev->power.is_prepared = false;
956
957 if (!dev->power.is_suspended)
958 goto Unlock;
959
960 if (dev->pm_domain) {
961 info = "power domain ";
962 callback = pm_op(&dev->pm_domain->ops, state);
963 goto Driver;
964 }
965
966 if (dev->type && dev->type->pm) {
967 info = "type ";
968 callback = pm_op(dev->type->pm, state);
969 goto Driver;
970 }
971
972 if (dev->class && dev->class->pm) {
973 info = "class ";
974 callback = pm_op(dev->class->pm, state);
975 goto Driver;
976 }
977
978 if (dev->bus) {
979 if (dev->bus->pm) {
980 info = "bus ";
981 callback = pm_op(dev->bus->pm, state);
982 } else if (dev->bus->resume) {
983 info = "legacy bus ";
984 callback = dev->bus->resume;
985 goto End;
986 }
987 }
988
989 Driver:
990 if (!callback && dev->driver && dev->driver->pm) {
991 info = "driver ";
992 callback = pm_op(dev->driver->pm, state);
993 }
994
995 End:
996 error = dpm_run_callback(callback, dev, state, info);
997 dev->power.is_suspended = false;
998
999 Unlock:
1000 device_unlock(dev);
1001 dpm_watchdog_clear(&wd);
1002
1003 Complete:
1004 complete_all(&dev->power.completion);
1005
1006 TRACE_RESUME(error);
1007
1008 return error;
1009}
1010
1011static void async_resume(void *data, async_cookie_t cookie)
1012{
1013 struct device *dev = (struct device *)data;
1014 int error;
1015
1016 error = device_resume(dev, pm_transition, true);
1017 if (error)
1018 pm_dev_err(dev, pm_transition, " async", error);
1019 put_device(dev);
1020}
1021
1022/**
1023 * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
1024 * @state: PM transition of the system being carried out.
1025 *
1026 * Execute the appropriate "resume" callback for all devices whose status
1027 * indicates that they are suspended.
1028 */
1029void dpm_resume(pm_message_t state)
1030{
1031 struct device *dev;
1032 ktime_t starttime = ktime_get();
1033
1034 trace_suspend_resume(TPS("dpm_resume"), state.event, true);
1035 might_sleep();
1036
1037 mutex_lock(&dpm_list_mtx);
1038 pm_transition = state;
1039 async_error = 0;
1040
1041 list_for_each_entry(dev, &dpm_suspended_list, power.entry)
1042 dpm_async_fn(dev, async_resume);
1043
1044 while (!list_empty(&dpm_suspended_list)) {
1045 dev = to_device(dpm_suspended_list.next);
1046 get_device(dev);
1047 if (!is_async(dev)) {
1048 int error;
1049
1050 mutex_unlock(&dpm_list_mtx);
1051
1052 error = device_resume(dev, state, false);
1053 if (error) {
1054 suspend_stats.failed_resume++;
1055 dpm_save_failed_step(SUSPEND_RESUME);
1056 dpm_save_failed_dev(dev_name(dev));
1057 pm_dev_err(dev, state, "", error);
1058 }
1059
1060 mutex_lock(&dpm_list_mtx);
1061 }
1062 if (!list_empty(&dev->power.entry))
1063 list_move_tail(&dev->power.entry, &dpm_prepared_list);
1064 put_device(dev);
1065 }
1066 mutex_unlock(&dpm_list_mtx);
1067 async_synchronize_full();
1068 dpm_show_time(starttime, state, 0, NULL);
1069
1070 cpufreq_resume();
1071 devfreq_resume();
1072 trace_suspend_resume(TPS("dpm_resume"), state.event, false);
1073}
1074
1075/**
1076 * device_complete - Complete a PM transition for given device.
1077 * @dev: Device to handle.
1078 * @state: PM transition of the system being carried out.
1079 */
1080static void device_complete(struct device *dev, pm_message_t state)
1081{
1082 void (*callback)(struct device *) = NULL;
1083 const char *info = NULL;
1084
1085 if (dev->power.syscore)
1086 return;
1087
1088 device_lock(dev);
1089
1090 if (dev->pm_domain) {
1091 info = "completing power domain ";
1092 callback = dev->pm_domain->ops.complete;
1093 } else if (dev->type && dev->type->pm) {
1094 info = "completing type ";
1095 callback = dev->type->pm->complete;
1096 } else if (dev->class && dev->class->pm) {
1097 info = "completing class ";
1098 callback = dev->class->pm->complete;
1099 } else if (dev->bus && dev->bus->pm) {
1100 info = "completing bus ";
1101 callback = dev->bus->pm->complete;
1102 }
1103
1104 if (!callback && dev->driver && dev->driver->pm) {
1105 info = "completing driver ";
1106 callback = dev->driver->pm->complete;
1107 }
1108
1109 if (callback) {
1110 pm_dev_dbg(dev, state, info);
1111 callback(dev);
1112 }
1113
1114 device_unlock(dev);
1115
1116 pm_runtime_put(dev);
1117}
1118
1119/**
1120 * dpm_complete - Complete a PM transition for all non-sysdev devices.
1121 * @state: PM transition of the system being carried out.
1122 *
1123 * Execute the ->complete() callbacks for all devices whose PM status is not
1124 * DPM_ON (this allows new devices to be registered).
1125 */
1126void dpm_complete(pm_message_t state)
1127{
1128 struct list_head list;
1129
1130 trace_suspend_resume(TPS("dpm_complete"), state.event, true);
1131 might_sleep();
1132
1133 INIT_LIST_HEAD(&list);
1134 mutex_lock(&dpm_list_mtx);
1135 while (!list_empty(&dpm_prepared_list)) {
1136 struct device *dev = to_device(dpm_prepared_list.prev);
1137
1138 get_device(dev);
1139 dev->power.is_prepared = false;
1140 list_move(&dev->power.entry, &list);
1141 mutex_unlock(&dpm_list_mtx);
1142
1143 trace_device_pm_callback_start(dev, "", state.event);
1144 device_complete(dev, state);
1145 trace_device_pm_callback_end(dev, 0);
1146
1147 mutex_lock(&dpm_list_mtx);
1148 put_device(dev);
1149 }
1150 list_splice(&list, &dpm_list);
1151 mutex_unlock(&dpm_list_mtx);
1152
1153 /* Allow device probing and trigger re-probing of deferred devices */
1154 device_unblock_probing();
1155 trace_suspend_resume(TPS("dpm_complete"), state.event, false);
1156}
1157
1158/**
1159 * dpm_resume_end - Execute "resume" callbacks and complete system transition.
1160 * @state: PM transition of the system being carried out.
1161 *
1162 * Execute "resume" callbacks for all devices and complete the PM transition of
1163 * the system.
1164 */
1165void dpm_resume_end(pm_message_t state)
1166{
1167 dpm_resume(state);
1168 dpm_complete(state);
1169}
1170EXPORT_SYMBOL_GPL(dpm_resume_end);
1171
1172
1173/*------------------------- Suspend routines -------------------------*/
1174
1175/**
1176 * resume_event - Return a "resume" message for given "suspend" sleep state.
1177 * @sleep_state: PM message representing a sleep state.
1178 *
1179 * Return a PM message representing the resume event corresponding to given
1180 * sleep state.
1181 */
1182static pm_message_t resume_event(pm_message_t sleep_state)
1183{
1184 switch (sleep_state.event) {
1185 case PM_EVENT_SUSPEND:
1186 return PMSG_RESUME;
1187 case PM_EVENT_FREEZE:
1188 case PM_EVENT_QUIESCE:
1189 return PMSG_RECOVER;
1190 case PM_EVENT_HIBERNATE:
1191 return PMSG_RESTORE;
1192 }
1193 return PMSG_ON;
1194}
1195
1196static void dpm_superior_set_must_resume(struct device *dev)
1197{
1198 struct device_link *link;
1199 int idx;
1200
1201 if (dev->parent)
1202 dev->parent->power.must_resume = true;
1203
1204 idx = device_links_read_lock();
1205
1206 list_for_each_entry_rcu(link, &dev->links.suppliers, c_node)
1207 link->supplier->power.must_resume = true;
1208
1209 device_links_read_unlock(idx);
1210}
1211
1212static pm_callback_t dpm_subsys_suspend_noirq_cb(struct device *dev,
1213 pm_message_t state,
1214 const char **info_p)
1215{
1216 pm_callback_t callback;
1217 const char *info;
1218
1219 if (dev->pm_domain) {
1220 info = "noirq power domain ";
1221 callback = pm_noirq_op(&dev->pm_domain->ops, state);
1222 } else if (dev->type && dev->type->pm) {
1223 info = "noirq type ";
1224 callback = pm_noirq_op(dev->type->pm, state);
1225 } else if (dev->class && dev->class->pm) {
1226 info = "noirq class ";
1227 callback = pm_noirq_op(dev->class->pm, state);
1228 } else if (dev->bus && dev->bus->pm) {
1229 info = "noirq bus ";
1230 callback = pm_noirq_op(dev->bus->pm, state);
1231 } else {
1232 return NULL;
1233 }
1234
1235 if (info_p)
1236 *info_p = info;
1237
1238 return callback;
1239}
1240
1241static bool device_must_resume(struct device *dev, pm_message_t state,
1242 bool no_subsys_suspend_noirq)
1243{
1244 pm_message_t resume_msg = resume_event(state);
1245
1246 /*
1247 * If all of the device driver's "noirq", "late" and "early" callbacks
1248 * are invoked directly by the core, the decision to allow the device to
1249 * stay in suspend can be based on its current runtime PM status and its
1250 * wakeup settings.
1251 */
1252 if (no_subsys_suspend_noirq &&
1253 !dpm_subsys_suspend_late_cb(dev, state, NULL) &&
1254 !dpm_subsys_resume_early_cb(dev, resume_msg, NULL) &&
1255 !dpm_subsys_resume_noirq_cb(dev, resume_msg, NULL))
1256 return !pm_runtime_status_suspended(dev) &&
1257 (resume_msg.event != PM_EVENT_RESUME ||
1258 (device_can_wakeup(dev) && !device_may_wakeup(dev)));
1259
1260 /*
1261 * The only safe strategy here is to require that if the device may not
1262 * be left in suspend, resume callbacks must be invoked for it.
1263 */
1264 return !dev->power.may_skip_resume;
1265}
1266
1267/**
1268 * __device_suspend_noirq - Execute a "noirq suspend" callback for given device.
1269 * @dev: Device to handle.
1270 * @state: PM transition of the system being carried out.
1271 * @async: If true, the device is being suspended asynchronously.
1272 *
1273 * The driver of @dev will not receive interrupts while this function is being
1274 * executed.
1275 */
1276static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool async)
1277{
1278 pm_callback_t callback;
1279 const char *info;
1280 bool no_subsys_cb = false;
1281 int error = 0;
1282
1283 TRACE_DEVICE(dev);
1284 TRACE_SUSPEND(0);
1285
1286 dpm_wait_for_subordinate(dev, async);
1287
1288 if (async_error)
1289 goto Complete;
1290
1291 if (dev->power.syscore || dev->power.direct_complete)
1292 goto Complete;
1293
1294 callback = dpm_subsys_suspend_noirq_cb(dev, state, &info);
1295 if (callback)
1296 goto Run;
1297
1298 no_subsys_cb = !dpm_subsys_suspend_late_cb(dev, state, NULL);
1299
1300 if (dev_pm_smart_suspend_and_suspended(dev) && no_subsys_cb)
1301 goto Skip;
1302
1303 if (dev->driver && dev->driver->pm) {
1304 info = "noirq driver ";
1305 callback = pm_noirq_op(dev->driver->pm, state);
1306 }
1307
1308Run:
1309 error = dpm_run_callback(callback, dev, state, info);
1310 if (error) {
1311 async_error = error;
1312 goto Complete;
1313 }
1314
1315Skip:
1316 dev->power.is_noirq_suspended = true;
1317
1318 if (dev_pm_test_driver_flags(dev, DPM_FLAG_LEAVE_SUSPENDED)) {
1319 dev->power.must_resume = dev->power.must_resume ||
1320 atomic_read(&dev->power.usage_count) > 1 ||
1321 device_must_resume(dev, state, no_subsys_cb);
1322 } else {
1323 dev->power.must_resume = true;
1324 }
1325
1326 if (dev->power.must_resume)
1327 dpm_superior_set_must_resume(dev);
1328
1329Complete:
1330 complete_all(&dev->power.completion);
1331 TRACE_SUSPEND(error);
1332 return error;
1333}
1334
1335static void async_suspend_noirq(void *data, async_cookie_t cookie)
1336{
1337 struct device *dev = (struct device *)data;
1338 int error;
1339
1340 error = __device_suspend_noirq(dev, pm_transition, true);
1341 if (error) {
1342 dpm_save_failed_dev(dev_name(dev));
1343 pm_dev_err(dev, pm_transition, " async", error);
1344 }
1345
1346 put_device(dev);
1347}
1348
1349static int device_suspend_noirq(struct device *dev)
1350{
1351 if (dpm_async_fn(dev, async_suspend_noirq))
1352 return 0;
1353
1354 return __device_suspend_noirq(dev, pm_transition, false);
1355}
1356
1357static int dpm_noirq_suspend_devices(pm_message_t state)
1358{
1359 ktime_t starttime = ktime_get();
1360 int error = 0;
1361
1362 trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, true);
1363 mutex_lock(&dpm_list_mtx);
1364 pm_transition = state;
1365 async_error = 0;
1366
1367 while (!list_empty(&dpm_late_early_list)) {
1368 struct device *dev = to_device(dpm_late_early_list.prev);
1369
1370 get_device(dev);
1371 mutex_unlock(&dpm_list_mtx);
1372
1373 error = device_suspend_noirq(dev);
1374
1375 mutex_lock(&dpm_list_mtx);
1376 if (error) {
1377 pm_dev_err(dev, state, " noirq", error);
1378 dpm_save_failed_dev(dev_name(dev));
1379 put_device(dev);
1380 break;
1381 }
1382 if (!list_empty(&dev->power.entry))
1383 list_move(&dev->power.entry, &dpm_noirq_list);
1384 put_device(dev);
1385
1386 if (async_error)
1387 break;
1388 }
1389 mutex_unlock(&dpm_list_mtx);
1390 async_synchronize_full();
1391 if (!error)
1392 error = async_error;
1393
1394 if (error) {
1395 suspend_stats.failed_suspend_noirq++;
1396 dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ);
1397 }
1398 dpm_show_time(starttime, state, error, "noirq");
1399 trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, false);
1400 return error;
1401}
1402
1403/**
1404 * dpm_suspend_noirq - Execute "noirq suspend" callbacks for all devices.
1405 * @state: PM transition of the system being carried out.
1406 *
1407 * Prevent device drivers' interrupt handlers from being called and invoke
1408 * "noirq" suspend callbacks for all non-sysdev devices.
1409 */
1410int dpm_suspend_noirq(pm_message_t state)
1411{
1412 int ret;
1413
1414 cpuidle_pause();
1415
1416 device_wakeup_arm_wake_irqs();
1417 suspend_device_irqs();
1418
1419 ret = dpm_noirq_suspend_devices(state);
1420 if (ret)
1421 dpm_resume_noirq(resume_event(state));
1422
1423 return ret;
1424}
1425
1426static void dpm_propagate_wakeup_to_parent(struct device *dev)
1427{
1428 struct device *parent = dev->parent;
1429
1430 if (!parent)
1431 return;
1432
1433 spin_lock_irq(&parent->power.lock);
1434
1435 if (dev->power.wakeup_path && !parent->power.ignore_children)
1436 parent->power.wakeup_path = true;
1437
1438 spin_unlock_irq(&parent->power.lock);
1439}
1440
1441static pm_callback_t dpm_subsys_suspend_late_cb(struct device *dev,
1442 pm_message_t state,
1443 const char **info_p)
1444{
1445 pm_callback_t callback;
1446 const char *info;
1447
1448 if (dev->pm_domain) {
1449 info = "late power domain ";
1450 callback = pm_late_early_op(&dev->pm_domain->ops, state);
1451 } else if (dev->type && dev->type->pm) {
1452 info = "late type ";
1453 callback = pm_late_early_op(dev->type->pm, state);
1454 } else if (dev->class && dev->class->pm) {
1455 info = "late class ";
1456 callback = pm_late_early_op(dev->class->pm, state);
1457 } else if (dev->bus && dev->bus->pm) {
1458 info = "late bus ";
1459 callback = pm_late_early_op(dev->bus->pm, state);
1460 } else {
1461 return NULL;
1462 }
1463
1464 if (info_p)
1465 *info_p = info;
1466
1467 return callback;
1468}
1469
1470/**
1471 * __device_suspend_late - Execute a "late suspend" callback for given device.
1472 * @dev: Device to handle.
1473 * @state: PM transition of the system being carried out.
1474 * @async: If true, the device is being suspended asynchronously.
1475 *
1476 * Runtime PM is disabled for @dev while this function is being executed.
1477 */
1478static int __device_suspend_late(struct device *dev, pm_message_t state, bool async)
1479{
1480 pm_callback_t callback;
1481 const char *info;
1482 int error = 0;
1483
1484 TRACE_DEVICE(dev);
1485 TRACE_SUSPEND(0);
1486
1487 __pm_runtime_disable(dev, false);
1488
1489 dpm_wait_for_subordinate(dev, async);
1490
1491 if (async_error)
1492 goto Complete;
1493
1494 if (pm_wakeup_pending()) {
1495 async_error = -EBUSY;
1496 goto Complete;
1497 }
1498
1499 if (dev->power.syscore || dev->power.direct_complete)
1500 goto Complete;
1501
1502 callback = dpm_subsys_suspend_late_cb(dev, state, &info);
1503 if (callback)
1504 goto Run;
1505
1506 if (dev_pm_smart_suspend_and_suspended(dev) &&
1507 !dpm_subsys_suspend_noirq_cb(dev, state, NULL))
1508 goto Skip;
1509
1510 if (dev->driver && dev->driver->pm) {
1511 info = "late driver ";
1512 callback = pm_late_early_op(dev->driver->pm, state);
1513 }
1514
1515Run:
1516 error = dpm_run_callback(callback, dev, state, info);
1517 if (error) {
1518 async_error = error;
1519 goto Complete;
1520 }
1521 dpm_propagate_wakeup_to_parent(dev);
1522
1523Skip:
1524 dev->power.is_late_suspended = true;
1525
1526Complete:
1527 TRACE_SUSPEND(error);
1528 complete_all(&dev->power.completion);
1529 return error;
1530}
1531
1532static void async_suspend_late(void *data, async_cookie_t cookie)
1533{
1534 struct device *dev = (struct device *)data;
1535 int error;
1536
1537 error = __device_suspend_late(dev, pm_transition, true);
1538 if (error) {
1539 dpm_save_failed_dev(dev_name(dev));
1540 pm_dev_err(dev, pm_transition, " async", error);
1541 }
1542 put_device(dev);
1543}
1544
1545static int device_suspend_late(struct device *dev)
1546{
1547 if (dpm_async_fn(dev, async_suspend_late))
1548 return 0;
1549
1550 return __device_suspend_late(dev, pm_transition, false);
1551}
1552
1553/**
1554 * dpm_suspend_late - Execute "late suspend" callbacks for all devices.
1555 * @state: PM transition of the system being carried out.
1556 */
1557int dpm_suspend_late(pm_message_t state)
1558{
1559 ktime_t starttime = ktime_get();
1560 int error = 0;
1561
1562 trace_suspend_resume(TPS("dpm_suspend_late"), state.event, true);
1563 mutex_lock(&dpm_list_mtx);
1564 pm_transition = state;
1565 async_error = 0;
1566
1567 while (!list_empty(&dpm_suspended_list)) {
1568 struct device *dev = to_device(dpm_suspended_list.prev);
1569
1570 get_device(dev);
1571 mutex_unlock(&dpm_list_mtx);
1572
1573 error = device_suspend_late(dev);
1574
1575 mutex_lock(&dpm_list_mtx);
1576 if (!list_empty(&dev->power.entry))
1577 list_move(&dev->power.entry, &dpm_late_early_list);
1578
1579 if (error) {
1580 pm_dev_err(dev, state, " late", error);
1581 dpm_save_failed_dev(dev_name(dev));
1582 put_device(dev);
1583 break;
1584 }
1585 put_device(dev);
1586
1587 if (async_error)
1588 break;
1589 }
1590 mutex_unlock(&dpm_list_mtx);
1591 async_synchronize_full();
1592 if (!error)
1593 error = async_error;
1594 if (error) {
1595 suspend_stats.failed_suspend_late++;
1596 dpm_save_failed_step(SUSPEND_SUSPEND_LATE);
1597 dpm_resume_early(resume_event(state));
1598 }
1599 dpm_show_time(starttime, state, error, "late");
1600 trace_suspend_resume(TPS("dpm_suspend_late"), state.event, false);
1601 return error;
1602}
1603
1604/**
1605 * dpm_suspend_end - Execute "late" and "noirq" device suspend callbacks.
1606 * @state: PM transition of the system being carried out.
1607 */
1608int dpm_suspend_end(pm_message_t state)
1609{
1610 ktime_t starttime = ktime_get();
1611 int error;
1612
1613 error = dpm_suspend_late(state);
1614 if (error)
1615 goto out;
1616
1617 error = dpm_suspend_noirq(state);
1618 if (error)
1619 dpm_resume_early(resume_event(state));
1620
1621out:
1622 dpm_show_time(starttime, state, error, "end");
1623 return error;
1624}
1625EXPORT_SYMBOL_GPL(dpm_suspend_end);
1626
1627/**
1628 * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
1629 * @dev: Device to suspend.
1630 * @state: PM transition of the system being carried out.
1631 * @cb: Suspend callback to execute.
1632 * @info: string description of caller.
1633 */
1634static int legacy_suspend(struct device *dev, pm_message_t state,
1635 int (*cb)(struct device *dev, pm_message_t state),
1636 const char *info)
1637{
1638 int error;
1639 ktime_t calltime;
1640
1641 calltime = initcall_debug_start(dev, cb);
1642
1643 trace_device_pm_callback_start(dev, info, state.event);
1644 error = cb(dev, state);
1645 trace_device_pm_callback_end(dev, error);
1646 suspend_report_result(cb, error);
1647
1648 initcall_debug_report(dev, calltime, cb, error);
1649
1650 return error;
1651}
1652
1653static void dpm_clear_superiors_direct_complete(struct device *dev)
1654{
1655 struct device_link *link;
1656 int idx;
1657
1658 if (dev->parent) {
1659 spin_lock_irq(&dev->parent->power.lock);
1660 dev->parent->power.direct_complete = false;
1661 spin_unlock_irq(&dev->parent->power.lock);
1662 }
1663
1664 idx = device_links_read_lock();
1665
1666 list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) {
1667 spin_lock_irq(&link->supplier->power.lock);
1668 link->supplier->power.direct_complete = false;
1669 spin_unlock_irq(&link->supplier->power.lock);
1670 }
1671
1672 device_links_read_unlock(idx);
1673}
1674
1675/**
1676 * __device_suspend - Execute "suspend" callbacks for given device.
1677 * @dev: Device to handle.
1678 * @state: PM transition of the system being carried out.
1679 * @async: If true, the device is being suspended asynchronously.
1680 */
1681static int __device_suspend(struct device *dev, pm_message_t state, bool async)
1682{
1683 pm_callback_t callback = NULL;
1684 const char *info = NULL;
1685 int error = 0;
1686 DECLARE_DPM_WATCHDOG_ON_STACK(wd);
1687
1688 TRACE_DEVICE(dev);
1689 TRACE_SUSPEND(0);
1690
1691 dpm_wait_for_subordinate(dev, async);
1692
1693 if (async_error) {
1694 dev->power.direct_complete = false;
1695 goto Complete;
1696 }
1697
1698 /*
1699 * If a device configured to wake up the system from sleep states
1700 * has been suspended at run time and there's a resume request pending
1701 * for it, this is equivalent to the device signaling wakeup, so the
1702 * system suspend operation should be aborted.
1703 */
1704 if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
1705 pm_wakeup_event(dev, 0);
1706
1707 if (pm_wakeup_pending()) {
1708 dev->power.direct_complete = false;
1709 async_error = -EBUSY;
1710 goto Complete;
1711 }
1712
1713 if (dev->power.syscore)
1714 goto Complete;
1715
1716 /* Avoid direct_complete to let wakeup_path propagate. */
1717 if (device_may_wakeup(dev) || dev->power.wakeup_path)
1718 dev->power.direct_complete = false;
1719
1720 if (dev->power.direct_complete) {
1721 if (pm_runtime_status_suspended(dev)) {
1722 pm_runtime_disable(dev);
1723 if (pm_runtime_status_suspended(dev)) {
1724 pm_dev_dbg(dev, state, "direct-complete ");
1725 goto Complete;
1726 }
1727
1728 pm_runtime_enable(dev);
1729 }
1730 dev->power.direct_complete = false;
1731 }
1732
1733 dev->power.may_skip_resume = false;
1734 dev->power.must_resume = false;
1735
1736 dpm_watchdog_set(&wd, dev);
1737 device_lock(dev);
1738
1739 if (dev->pm_domain) {
1740 info = "power domain ";
1741 callback = pm_op(&dev->pm_domain->ops, state);
1742 goto Run;
1743 }
1744
1745 if (dev->type && dev->type->pm) {
1746 info = "type ";
1747 callback = pm_op(dev->type->pm, state);
1748 goto Run;
1749 }
1750
1751 if (dev->class && dev->class->pm) {
1752 info = "class ";
1753 callback = pm_op(dev->class->pm, state);
1754 goto Run;
1755 }
1756
1757 if (dev->bus) {
1758 if (dev->bus->pm) {
1759 info = "bus ";
1760 callback = pm_op(dev->bus->pm, state);
1761 } else if (dev->bus->suspend) {
1762 pm_dev_dbg(dev, state, "legacy bus ");
1763 error = legacy_suspend(dev, state, dev->bus->suspend,
1764 "legacy bus ");
1765 goto End;
1766 }
1767 }
1768
1769 Run:
1770 if (!callback && dev->driver && dev->driver->pm) {
1771 info = "driver ";
1772 callback = pm_op(dev->driver->pm, state);
1773 }
1774
1775 error = dpm_run_callback(callback, dev, state, info);
1776
1777 End:
1778 if (!error) {
1779 dev->power.is_suspended = true;
1780 if (device_may_wakeup(dev))
1781 dev->power.wakeup_path = true;
1782
1783 dpm_propagate_wakeup_to_parent(dev);
1784 dpm_clear_superiors_direct_complete(dev);
1785 }
1786
1787 device_unlock(dev);
1788 dpm_watchdog_clear(&wd);
1789
1790 Complete:
1791 if (error)
1792 async_error = error;
1793
1794 complete_all(&dev->power.completion);
1795 TRACE_SUSPEND(error);
1796 return error;
1797}
1798
1799static void async_suspend(void *data, async_cookie_t cookie)
1800{
1801 struct device *dev = (struct device *)data;
1802 int error;
1803
1804 error = __device_suspend(dev, pm_transition, true);
1805 if (error) {
1806 dpm_save_failed_dev(dev_name(dev));
1807 pm_dev_err(dev, pm_transition, " async", error);
1808 }
1809
1810 put_device(dev);
1811}
1812
1813static int device_suspend(struct device *dev)
1814{
1815 if (dpm_async_fn(dev, async_suspend))
1816 return 0;
1817
1818 return __device_suspend(dev, pm_transition, false);
1819}
1820
1821/**
1822 * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
1823 * @state: PM transition of the system being carried out.
1824 */
1825int dpm_suspend(pm_message_t state)
1826{
1827 ktime_t starttime = ktime_get();
1828 int error = 0;
1829
1830 trace_suspend_resume(TPS("dpm_suspend"), state.event, true);
1831 might_sleep();
1832
1833 devfreq_suspend();
1834 cpufreq_suspend();
1835
1836 mutex_lock(&dpm_list_mtx);
1837 pm_transition = state;
1838 async_error = 0;
1839 while (!list_empty(&dpm_prepared_list)) {
1840 struct device *dev = to_device(dpm_prepared_list.prev);
1841
1842 get_device(dev);
1843 mutex_unlock(&dpm_list_mtx);
1844
1845 error = device_suspend(dev);
1846
1847 mutex_lock(&dpm_list_mtx);
1848 if (error) {
1849 pm_dev_err(dev, state, "", error);
1850 dpm_save_failed_dev(dev_name(dev));
1851 put_device(dev);
1852 break;
1853 }
1854 if (!list_empty(&dev->power.entry))
1855 list_move(&dev->power.entry, &dpm_suspended_list);
1856 put_device(dev);
1857 if (async_error)
1858 break;
1859 }
1860 mutex_unlock(&dpm_list_mtx);
1861 async_synchronize_full();
1862 if (!error)
1863 error = async_error;
1864 if (error) {
1865 suspend_stats.failed_suspend++;
1866 dpm_save_failed_step(SUSPEND_SUSPEND);
1867 }
1868 dpm_show_time(starttime, state, error, NULL);
1869 trace_suspend_resume(TPS("dpm_suspend"), state.event, false);
1870 return error;
1871}
1872
1873/**
1874 * device_prepare - Prepare a device for system power transition.
1875 * @dev: Device to handle.
1876 * @state: PM transition of the system being carried out.
1877 *
1878 * Execute the ->prepare() callback(s) for given device. No new children of the
1879 * device may be registered after this function has returned.
1880 */
1881static int device_prepare(struct device *dev, pm_message_t state)
1882{
1883 int (*callback)(struct device *) = NULL;
1884 int ret = 0;
1885
1886 if (dev->power.syscore)
1887 return 0;
1888
1889 WARN_ON(!pm_runtime_enabled(dev) &&
1890 dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND |
1891 DPM_FLAG_LEAVE_SUSPENDED));
1892
1893 /*
1894 * If a device's parent goes into runtime suspend at the wrong time,
1895 * it won't be possible to resume the device. To prevent this we
1896 * block runtime suspend here, during the prepare phase, and allow
1897 * it again during the complete phase.
1898 */
1899 pm_runtime_get_noresume(dev);
1900
1901 device_lock(dev);
1902
1903 dev->power.wakeup_path = false;
1904
1905 if (dev->power.no_pm_callbacks)
1906 goto unlock;
1907
1908 if (dev->pm_domain)
1909 callback = dev->pm_domain->ops.prepare;
1910 else if (dev->type && dev->type->pm)
1911 callback = dev->type->pm->prepare;
1912 else if (dev->class && dev->class->pm)
1913 callback = dev->class->pm->prepare;
1914 else if (dev->bus && dev->bus->pm)
1915 callback = dev->bus->pm->prepare;
1916
1917 if (!callback && dev->driver && dev->driver->pm)
1918 callback = dev->driver->pm->prepare;
1919
1920 if (callback)
1921 ret = callback(dev);
1922
1923unlock:
1924 device_unlock(dev);
1925
1926 if (ret < 0) {
1927 suspend_report_result(callback, ret);
1928 pm_runtime_put(dev);
1929 return ret;
1930 }
1931 /*
1932 * A positive return value from ->prepare() means "this device appears
1933 * to be runtime-suspended and its state is fine, so if it really is
1934 * runtime-suspended, you can leave it in that state provided that you
1935 * will do the same thing with all of its descendants". This only
1936 * applies to suspend transitions, however.
1937 */
1938 spin_lock_irq(&dev->power.lock);
1939 dev->power.direct_complete = state.event == PM_EVENT_SUSPEND &&
1940 ((pm_runtime_suspended(dev) && ret > 0) ||
1941 dev->power.no_pm_callbacks) &&
1942 !dev_pm_test_driver_flags(dev, DPM_FLAG_NEVER_SKIP);
1943 spin_unlock_irq(&dev->power.lock);
1944 return 0;
1945}
1946
1947/**
1948 * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1949 * @state: PM transition of the system being carried out.
1950 *
1951 * Execute the ->prepare() callback(s) for all devices.
1952 */
1953int dpm_prepare(pm_message_t state)
1954{
1955 int error = 0;
1956
1957 trace_suspend_resume(TPS("dpm_prepare"), state.event, true);
1958 might_sleep();
1959
1960 /*
1961 * Give a chance for the known devices to complete their probes, before
1962 * disable probing of devices. This sync point is important at least
1963 * at boot time + hibernation restore.
1964 */
1965 wait_for_device_probe();
1966 /*
1967 * It is unsafe if probing of devices will happen during suspend or
1968 * hibernation and system behavior will be unpredictable in this case.
1969 * So, let's prohibit device's probing here and defer their probes
1970 * instead. The normal behavior will be restored in dpm_complete().
1971 */
1972 device_block_probing();
1973
1974 mutex_lock(&dpm_list_mtx);
1975 while (!list_empty(&dpm_list)) {
1976 struct device *dev = to_device(dpm_list.next);
1977
1978 get_device(dev);
1979 mutex_unlock(&dpm_list_mtx);
1980
1981 trace_device_pm_callback_start(dev, "", state.event);
1982 error = device_prepare(dev, state);
1983 trace_device_pm_callback_end(dev, error);
1984
1985 mutex_lock(&dpm_list_mtx);
1986 if (error) {
1987 if (error == -EAGAIN) {
1988 put_device(dev);
1989 error = 0;
1990 continue;
1991 }
1992 pr_info("Device %s not prepared for power transition: code %d\n",
1993 dev_name(dev), error);
1994 put_device(dev);
1995 break;
1996 }
1997 dev->power.is_prepared = true;
1998 if (!list_empty(&dev->power.entry))
1999 list_move_tail(&dev->power.entry, &dpm_prepared_list);
2000 put_device(dev);
2001 }
2002 mutex_unlock(&dpm_list_mtx);
2003 trace_suspend_resume(TPS("dpm_prepare"), state.event, false);
2004 return error;
2005}
2006
2007/**
2008 * dpm_suspend_start - Prepare devices for PM transition and suspend them.
2009 * @state: PM transition of the system being carried out.
2010 *
2011 * Prepare all non-sysdev devices for system PM transition and execute "suspend"
2012 * callbacks for them.
2013 */
2014int dpm_suspend_start(pm_message_t state)
2015{
2016 ktime_t starttime = ktime_get();
2017 int error;
2018
2019 error = dpm_prepare(state);
2020 if (error) {
2021 suspend_stats.failed_prepare++;
2022 dpm_save_failed_step(SUSPEND_PREPARE);
2023 } else
2024 error = dpm_suspend(state);
2025 dpm_show_time(starttime, state, error, "start");
2026 return error;
2027}
2028EXPORT_SYMBOL_GPL(dpm_suspend_start);
2029
2030void __suspend_report_result(const char *function, void *fn, int ret)
2031{
2032 if (ret)
2033 pr_err("%s(): %pS returns %d\n", function, fn, ret);
2034}
2035EXPORT_SYMBOL_GPL(__suspend_report_result);
2036
2037/**
2038 * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
2039 * @subordinate: Device that needs to wait for @dev.
2040 * @dev: Device to wait for.
2041 */
2042int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
2043{
2044 dpm_wait(dev, subordinate->power.async_suspend);
2045 return async_error;
2046}
2047EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);
2048
2049/**
2050 * dpm_for_each_dev - device iterator.
2051 * @data: data for the callback.
2052 * @fn: function to be called for each device.
2053 *
2054 * Iterate over devices in dpm_list, and call @fn for each device,
2055 * passing it @data.
2056 */
2057void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *))
2058{
2059 struct device *dev;
2060
2061 if (!fn)
2062 return;
2063
2064 device_pm_lock();
2065 list_for_each_entry(dev, &dpm_list, power.entry)
2066 fn(dev, data);
2067 device_pm_unlock();
2068}
2069EXPORT_SYMBOL_GPL(dpm_for_each_dev);
2070
2071static bool pm_ops_is_empty(const struct dev_pm_ops *ops)
2072{
2073 if (!ops)
2074 return true;
2075
2076 return !ops->prepare &&
2077 !ops->suspend &&
2078 !ops->suspend_late &&
2079 !ops->suspend_noirq &&
2080 !ops->resume_noirq &&
2081 !ops->resume_early &&
2082 !ops->resume &&
2083 !ops->complete;
2084}
2085
2086void device_pm_check_callbacks(struct device *dev)
2087{
2088 spin_lock_irq(&dev->power.lock);
2089 dev->power.no_pm_callbacks =
2090 (!dev->bus || (pm_ops_is_empty(dev->bus->pm) &&
2091 !dev->bus->suspend && !dev->bus->resume)) &&
2092 (!dev->class || pm_ops_is_empty(dev->class->pm)) &&
2093 (!dev->type || pm_ops_is_empty(dev->type->pm)) &&
2094 (!dev->pm_domain || pm_ops_is_empty(&dev->pm_domain->ops)) &&
2095 (!dev->driver || (pm_ops_is_empty(dev->driver->pm) &&
2096 !dev->driver->suspend && !dev->driver->resume));
2097 spin_unlock_irq(&dev->power.lock);
2098}
2099
2100bool dev_pm_smart_suspend_and_suspended(struct device *dev)
2101{
2102 return dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) &&
2103 pm_runtime_status_suspended(dev);
2104}