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