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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/export.h>
22#include <linux/mutex.h>
23#include <linux/pm.h>
24#include <linux/pm_runtime.h>
25#include <linux/pm-trace.h>
26#include <linux/pm_wakeirq.h>
27#include <linux/interrupt.h>
28#include <linux/sched.h>
29#include <linux/sched/debug.h>
30#include <linux/async.h>
31#include <linux/suspend.h>
32#include <trace/events/power.h>
33#include <linux/cpufreq.h>
34#include <linux/cpuidle.h>
35#include <linux/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 const 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,
211 const char *info)
212{
213 ktime_t rettime;
214 s64 nsecs;
215
216 rettime = ktime_get();
217 nsecs = (s64) ktime_to_ns(ktime_sub(rettime, calltime));
218
219 if (pm_print_times_enabled) {
220 pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev),
221 error, (unsigned long long)nsecs >> 10);
222 }
223}
224
225/**
226 * dpm_wait - Wait for a PM operation to complete.
227 * @dev: Device to wait for.
228 * @async: If unset, wait only if the device's power.async_suspend flag is set.
229 */
230static void dpm_wait(struct device *dev, bool async)
231{
232 if (!dev)
233 return;
234
235 if (async || (pm_async_enabled && dev->power.async_suspend))
236 wait_for_completion(&dev->power.completion);
237}
238
239static int dpm_wait_fn(struct device *dev, void *async_ptr)
240{
241 dpm_wait(dev, *((bool *)async_ptr));
242 return 0;
243}
244
245static void dpm_wait_for_children(struct device *dev, bool async)
246{
247 device_for_each_child(dev, &async, dpm_wait_fn);
248}
249
250static void dpm_wait_for_suppliers(struct device *dev, bool async)
251{
252 struct device_link *link;
253 int idx;
254
255 idx = device_links_read_lock();
256
257 /*
258 * If the supplier goes away right after we've checked the link to it,
259 * we'll wait for its completion to change the state, but that's fine,
260 * because the only things that will block as a result are the SRCU
261 * callbacks freeing the link objects for the links in the list we're
262 * walking.
263 */
264 list_for_each_entry_rcu(link, &dev->links.suppliers, c_node)
265 if (READ_ONCE(link->status) != DL_STATE_DORMANT)
266 dpm_wait(link->supplier, async);
267
268 device_links_read_unlock(idx);
269}
270
271static void dpm_wait_for_superior(struct device *dev, bool async)
272{
273 dpm_wait(dev->parent, async);
274 dpm_wait_for_suppliers(dev, async);
275}
276
277static void dpm_wait_for_consumers(struct device *dev, bool async)
278{
279 struct device_link *link;
280 int idx;
281
282 idx = device_links_read_lock();
283
284 /*
285 * The status of a device link can only be changed from "dormant" by a
286 * probe, but that cannot happen during system suspend/resume. In
287 * theory it can change to "dormant" at that time, but then it is
288 * reasonable to wait for the target device anyway (eg. if it goes
289 * away, it's better to wait for it to go away completely and then
290 * continue instead of trying to continue in parallel with its
291 * unregistration).
292 */
293 list_for_each_entry_rcu(link, &dev->links.consumers, s_node)
294 if (READ_ONCE(link->status) != DL_STATE_DORMANT)
295 dpm_wait(link->consumer, async);
296
297 device_links_read_unlock(idx);
298}
299
300static void dpm_wait_for_subordinate(struct device *dev, bool async)
301{
302 dpm_wait_for_children(dev, async);
303 dpm_wait_for_consumers(dev, async);
304}
305
306/**
307 * pm_op - Return the PM operation appropriate for given PM event.
308 * @ops: PM operations to choose from.
309 * @state: PM transition of the system being carried out.
310 */
311static pm_callback_t pm_op(const struct dev_pm_ops *ops, pm_message_t state)
312{
313 switch (state.event) {
314#ifdef CONFIG_SUSPEND
315 case PM_EVENT_SUSPEND:
316 return ops->suspend;
317 case PM_EVENT_RESUME:
318 return ops->resume;
319#endif /* CONFIG_SUSPEND */
320#ifdef CONFIG_HIBERNATE_CALLBACKS
321 case PM_EVENT_FREEZE:
322 case PM_EVENT_QUIESCE:
323 return ops->freeze;
324 case PM_EVENT_HIBERNATE:
325 return ops->poweroff;
326 case PM_EVENT_THAW:
327 case PM_EVENT_RECOVER:
328 return ops->thaw;
329 break;
330 case PM_EVENT_RESTORE:
331 return ops->restore;
332#endif /* CONFIG_HIBERNATE_CALLBACKS */
333 }
334
335 return NULL;
336}
337
338/**
339 * pm_late_early_op - Return the PM operation appropriate for given PM event.
340 * @ops: PM operations to choose from.
341 * @state: PM transition of the system being carried out.
342 *
343 * Runtime PM is disabled for @dev while this function is being executed.
344 */
345static pm_callback_t pm_late_early_op(const struct dev_pm_ops *ops,
346 pm_message_t state)
347{
348 switch (state.event) {
349#ifdef CONFIG_SUSPEND
350 case PM_EVENT_SUSPEND:
351 return ops->suspend_late;
352 case PM_EVENT_RESUME:
353 return ops->resume_early;
354#endif /* CONFIG_SUSPEND */
355#ifdef CONFIG_HIBERNATE_CALLBACKS
356 case PM_EVENT_FREEZE:
357 case PM_EVENT_QUIESCE:
358 return ops->freeze_late;
359 case PM_EVENT_HIBERNATE:
360 return ops->poweroff_late;
361 case PM_EVENT_THAW:
362 case PM_EVENT_RECOVER:
363 return ops->thaw_early;
364 case PM_EVENT_RESTORE:
365 return ops->restore_early;
366#endif /* CONFIG_HIBERNATE_CALLBACKS */
367 }
368
369 return NULL;
370}
371
372/**
373 * pm_noirq_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 * The driver of @dev will not receive interrupts while this function is being
378 * executed.
379 */
380static pm_callback_t pm_noirq_op(const struct dev_pm_ops *ops, pm_message_t state)
381{
382 switch (state.event) {
383#ifdef CONFIG_SUSPEND
384 case PM_EVENT_SUSPEND:
385 return ops->suspend_noirq;
386 case PM_EVENT_RESUME:
387 return ops->resume_noirq;
388#endif /* CONFIG_SUSPEND */
389#ifdef CONFIG_HIBERNATE_CALLBACKS
390 case PM_EVENT_FREEZE:
391 case PM_EVENT_QUIESCE:
392 return ops->freeze_noirq;
393 case PM_EVENT_HIBERNATE:
394 return ops->poweroff_noirq;
395 case PM_EVENT_THAW:
396 case PM_EVENT_RECOVER:
397 return ops->thaw_noirq;
398 case PM_EVENT_RESTORE:
399 return ops->restore_noirq;
400#endif /* CONFIG_HIBERNATE_CALLBACKS */
401 }
402
403 return NULL;
404}
405
406static void pm_dev_dbg(struct device *dev, pm_message_t state, const char *info)
407{
408 dev_dbg(dev, "%s%s%s\n", info, pm_verb(state.event),
409 ((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
410 ", may wakeup" : "");
411}
412
413static void pm_dev_err(struct device *dev, pm_message_t state, const char *info,
414 int error)
415{
416 printk(KERN_ERR "PM: Device %s failed to %s%s: error %d\n",
417 dev_name(dev), pm_verb(state.event), info, error);
418}
419
420static void dpm_show_time(ktime_t starttime, pm_message_t state, int error,
421 const char *info)
422{
423 ktime_t calltime;
424 u64 usecs64;
425 int usecs;
426
427 calltime = ktime_get();
428 usecs64 = ktime_to_ns(ktime_sub(calltime, starttime));
429 do_div(usecs64, NSEC_PER_USEC);
430 usecs = usecs64;
431 if (usecs == 0)
432 usecs = 1;
433
434 pm_pr_dbg("%s%s%s of devices %s after %ld.%03ld msecs\n",
435 info ?: "", info ? " " : "", pm_verb(state.event),
436 error ? "aborted" : "complete",
437 usecs / USEC_PER_MSEC, usecs % USEC_PER_MSEC);
438}
439
440static int dpm_run_callback(pm_callback_t cb, struct device *dev,
441 pm_message_t state, const char *info)
442{
443 ktime_t calltime;
444 int error;
445
446 if (!cb)
447 return 0;
448
449 calltime = initcall_debug_start(dev);
450
451 pm_dev_dbg(dev, state, info);
452 trace_device_pm_callback_start(dev, info, state.event);
453 error = cb(dev);
454 trace_device_pm_callback_end(dev, error);
455 suspend_report_result(cb, error);
456
457 initcall_debug_report(dev, calltime, error, state, info);
458
459 return error;
460}
461
462#ifdef CONFIG_DPM_WATCHDOG
463struct dpm_watchdog {
464 struct device *dev;
465 struct task_struct *tsk;
466 struct timer_list timer;
467};
468
469#define DECLARE_DPM_WATCHDOG_ON_STACK(wd) \
470 struct dpm_watchdog wd
471
472/**
473 * dpm_watchdog_handler - Driver suspend / resume watchdog handler.
474 * @data: Watchdog object address.
475 *
476 * Called when a driver has timed out suspending or resuming.
477 * There's not much we can do here to recover so panic() to
478 * capture a crash-dump in pstore.
479 */
480static void dpm_watchdog_handler(struct timer_list *t)
481{
482 struct dpm_watchdog *wd = from_timer(wd, t, timer);
483
484 dev_emerg(wd->dev, "**** DPM device timeout ****\n");
485 show_stack(wd->tsk, NULL);
486 panic("%s %s: unrecoverable failure\n",
487 dev_driver_string(wd->dev), dev_name(wd->dev));
488}
489
490/**
491 * dpm_watchdog_set - Enable pm watchdog for given device.
492 * @wd: Watchdog. Must be allocated on the stack.
493 * @dev: Device to handle.
494 */
495static void dpm_watchdog_set(struct dpm_watchdog *wd, struct device *dev)
496{
497 struct timer_list *timer = &wd->timer;
498
499 wd->dev = dev;
500 wd->tsk = current;
501
502 timer_setup_on_stack(timer, dpm_watchdog_handler, 0);
503 /* use same timeout value for both suspend and resume */
504 timer->expires = jiffies + HZ * CONFIG_DPM_WATCHDOG_TIMEOUT;
505 add_timer(timer);
506}
507
508/**
509 * dpm_watchdog_clear - Disable suspend/resume watchdog.
510 * @wd: Watchdog to disable.
511 */
512static void dpm_watchdog_clear(struct dpm_watchdog *wd)
513{
514 struct timer_list *timer = &wd->timer;
515
516 del_timer_sync(timer);
517 destroy_timer_on_stack(timer);
518}
519#else
520#define DECLARE_DPM_WATCHDOG_ON_STACK(wd)
521#define dpm_watchdog_set(x, y)
522#define dpm_watchdog_clear(x)
523#endif
524
525/*------------------------- Resume routines -------------------------*/
526
527/**
528 * dev_pm_skip_next_resume_phases - Skip next system resume phases for device.
529 * @dev: Target device.
530 *
531 * Make the core skip the "early resume" and "resume" phases for @dev.
532 *
533 * This function can be called by middle-layer code during the "noirq" phase of
534 * system resume if necessary, but not by device drivers.
535 */
536void dev_pm_skip_next_resume_phases(struct device *dev)
537{
538 dev->power.is_late_suspended = false;
539 dev->power.is_suspended = false;
540}
541
542/**
543 * suspend_event - Return a "suspend" message for given "resume" one.
544 * @resume_msg: PM message representing a system-wide resume transition.
545 */
546static pm_message_t suspend_event(pm_message_t resume_msg)
547{
548 switch (resume_msg.event) {
549 case PM_EVENT_RESUME:
550 return PMSG_SUSPEND;
551 case PM_EVENT_THAW:
552 case PM_EVENT_RESTORE:
553 return PMSG_FREEZE;
554 case PM_EVENT_RECOVER:
555 return PMSG_HIBERNATE;
556 }
557 return PMSG_ON;
558}
559
560/**
561 * dev_pm_may_skip_resume - System-wide device resume optimization check.
562 * @dev: Target device.
563 *
564 * Checks whether or not the device may be left in suspend after a system-wide
565 * transition to the working state.
566 */
567bool dev_pm_may_skip_resume(struct device *dev)
568{
569 return !dev->power.must_resume && pm_transition.event != PM_EVENT_RESTORE;
570}
571
572static pm_callback_t dpm_subsys_resume_noirq_cb(struct device *dev,
573 pm_message_t state,
574 const char **info_p)
575{
576 pm_callback_t callback;
577 const char *info;
578
579 if (dev->pm_domain) {
580 info = "noirq power domain ";
581 callback = pm_noirq_op(&dev->pm_domain->ops, state);
582 } else if (dev->type && dev->type->pm) {
583 info = "noirq type ";
584 callback = pm_noirq_op(dev->type->pm, state);
585 } else if (dev->class && dev->class->pm) {
586 info = "noirq class ";
587 callback = pm_noirq_op(dev->class->pm, state);
588 } else if (dev->bus && dev->bus->pm) {
589 info = "noirq bus ";
590 callback = pm_noirq_op(dev->bus->pm, state);
591 } else {
592 return NULL;
593 }
594
595 if (info_p)
596 *info_p = info;
597
598 return callback;
599}
600
601static pm_callback_t dpm_subsys_suspend_noirq_cb(struct device *dev,
602 pm_message_t state,
603 const char **info_p);
604
605static pm_callback_t dpm_subsys_suspend_late_cb(struct device *dev,
606 pm_message_t state,
607 const char **info_p);
608
609/**
610 * device_resume_noirq - Execute a "noirq resume" callback for given device.
611 * @dev: Device to handle.
612 * @state: PM transition of the system being carried out.
613 * @async: If true, the device is being resumed asynchronously.
614 *
615 * The driver of @dev will not receive interrupts while this function is being
616 * executed.
617 */
618static int device_resume_noirq(struct device *dev, pm_message_t state, bool async)
619{
620 pm_callback_t callback;
621 const char *info;
622 bool skip_resume;
623 int error = 0;
624
625 TRACE_DEVICE(dev);
626 TRACE_RESUME(0);
627
628 if (dev->power.syscore || dev->power.direct_complete)
629 goto Out;
630
631 if (!dev->power.is_noirq_suspended)
632 goto Out;
633
634 dpm_wait_for_superior(dev, async);
635
636 skip_resume = dev_pm_may_skip_resume(dev);
637
638 callback = dpm_subsys_resume_noirq_cb(dev, state, &info);
639 if (callback)
640 goto Run;
641
642 if (skip_resume)
643 goto Skip;
644
645 if (dev_pm_smart_suspend_and_suspended(dev)) {
646 pm_message_t suspend_msg = suspend_event(state);
647
648 /*
649 * If "freeze" callbacks have been skipped during a transition
650 * related to hibernation, the subsequent "thaw" callbacks must
651 * be skipped too or bad things may happen. Otherwise, resume
652 * callbacks are going to be run for the device, so its runtime
653 * PM status must be changed to reflect the new state after the
654 * transition under way.
655 */
656 if (!dpm_subsys_suspend_late_cb(dev, suspend_msg, NULL) &&
657 !dpm_subsys_suspend_noirq_cb(dev, suspend_msg, NULL)) {
658 if (state.event == PM_EVENT_THAW) {
659 skip_resume = true;
660 goto Skip;
661 } else {
662 pm_runtime_set_active(dev);
663 }
664 }
665 }
666
667 if (dev->driver && dev->driver->pm) {
668 info = "noirq driver ";
669 callback = pm_noirq_op(dev->driver->pm, state);
670 }
671
672Run:
673 error = dpm_run_callback(callback, dev, state, info);
674
675Skip:
676 dev->power.is_noirq_suspended = false;
677
678 if (skip_resume) {
679 /*
680 * The device is going to be left in suspend, but it might not
681 * have been in runtime suspend before the system suspended, so
682 * its runtime PM status needs to be updated to avoid confusing
683 * the runtime PM framework when runtime PM is enabled for the
684 * device again.
685 */
686 pm_runtime_set_suspended(dev);
687 dev_pm_skip_next_resume_phases(dev);
688 }
689
690Out:
691 complete_all(&dev->power.completion);
692 TRACE_RESUME(error);
693 return error;
694}
695
696static bool is_async(struct device *dev)
697{
698 return dev->power.async_suspend && pm_async_enabled
699 && !pm_trace_is_enabled();
700}
701
702static void async_resume_noirq(void *data, async_cookie_t cookie)
703{
704 struct device *dev = (struct device *)data;
705 int error;
706
707 error = device_resume_noirq(dev, pm_transition, true);
708 if (error)
709 pm_dev_err(dev, pm_transition, " async", error);
710
711 put_device(dev);
712}
713
714void dpm_noirq_resume_devices(pm_message_t state)
715{
716 struct device *dev;
717 ktime_t starttime = ktime_get();
718
719 trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, true);
720 mutex_lock(&dpm_list_mtx);
721 pm_transition = state;
722
723 /*
724 * Advanced the async threads upfront,
725 * in case the starting of async threads is
726 * delayed by non-async resuming devices.
727 */
728 list_for_each_entry(dev, &dpm_noirq_list, power.entry) {
729 reinit_completion(&dev->power.completion);
730 if (is_async(dev)) {
731 get_device(dev);
732 async_schedule(async_resume_noirq, dev);
733 }
734 }
735
736 while (!list_empty(&dpm_noirq_list)) {
737 dev = to_device(dpm_noirq_list.next);
738 get_device(dev);
739 list_move_tail(&dev->power.entry, &dpm_late_early_list);
740 mutex_unlock(&dpm_list_mtx);
741
742 if (!is_async(dev)) {
743 int error;
744
745 error = device_resume_noirq(dev, state, false);
746 if (error) {
747 suspend_stats.failed_resume_noirq++;
748 dpm_save_failed_step(SUSPEND_RESUME_NOIRQ);
749 dpm_save_failed_dev(dev_name(dev));
750 pm_dev_err(dev, state, " noirq", error);
751 }
752 }
753
754 mutex_lock(&dpm_list_mtx);
755 put_device(dev);
756 }
757 mutex_unlock(&dpm_list_mtx);
758 async_synchronize_full();
759 dpm_show_time(starttime, state, 0, "noirq");
760 trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, false);
761}
762
763void dpm_noirq_end(void)
764{
765 resume_device_irqs();
766 device_wakeup_disarm_wake_irqs();
767 cpuidle_resume();
768}
769
770/**
771 * dpm_resume_noirq - Execute "noirq resume" callbacks for all devices.
772 * @state: PM transition of the system being carried out.
773 *
774 * Invoke the "noirq" resume callbacks for all devices in dpm_noirq_list and
775 * allow device drivers' interrupt handlers to be called.
776 */
777void dpm_resume_noirq(pm_message_t state)
778{
779 dpm_noirq_resume_devices(state);
780 dpm_noirq_end();
781}
782
783static pm_callback_t dpm_subsys_resume_early_cb(struct device *dev,
784 pm_message_t state,
785 const char **info_p)
786{
787 pm_callback_t callback;
788 const char *info;
789
790 if (dev->pm_domain) {
791 info = "early power domain ";
792 callback = pm_late_early_op(&dev->pm_domain->ops, state);
793 } else if (dev->type && dev->type->pm) {
794 info = "early type ";
795 callback = pm_late_early_op(dev->type->pm, state);
796 } else if (dev->class && dev->class->pm) {
797 info = "early class ";
798 callback = pm_late_early_op(dev->class->pm, state);
799 } else if (dev->bus && dev->bus->pm) {
800 info = "early bus ";
801 callback = pm_late_early_op(dev->bus->pm, state);
802 } else {
803 return NULL;
804 }
805
806 if (info_p)
807 *info_p = info;
808
809 return callback;
810}
811
812/**
813 * device_resume_early - Execute an "early resume" callback for given device.
814 * @dev: Device to handle.
815 * @state: PM transition of the system being carried out.
816 * @async: If true, the device is being resumed asynchronously.
817 *
818 * Runtime PM is disabled for @dev while this function is being executed.
819 */
820static int device_resume_early(struct device *dev, pm_message_t state, bool async)
821{
822 pm_callback_t callback;
823 const char *info;
824 int error = 0;
825
826 TRACE_DEVICE(dev);
827 TRACE_RESUME(0);
828
829 if (dev->power.syscore || dev->power.direct_complete)
830 goto Out;
831
832 if (!dev->power.is_late_suspended)
833 goto Out;
834
835 dpm_wait_for_superior(dev, async);
836
837 callback = dpm_subsys_resume_early_cb(dev, state, &info);
838
839 if (!callback && dev->driver && dev->driver->pm) {
840 info = "early driver ";
841 callback = pm_late_early_op(dev->driver->pm, state);
842 }
843
844 error = dpm_run_callback(callback, dev, state, info);
845 dev->power.is_late_suspended = false;
846
847 Out:
848 TRACE_RESUME(error);
849
850 pm_runtime_enable(dev);
851 complete_all(&dev->power.completion);
852 return error;
853}
854
855static void async_resume_early(void *data, async_cookie_t cookie)
856{
857 struct device *dev = (struct device *)data;
858 int error;
859
860 error = device_resume_early(dev, pm_transition, true);
861 if (error)
862 pm_dev_err(dev, pm_transition, " async", error);
863
864 put_device(dev);
865}
866
867/**
868 * dpm_resume_early - Execute "early resume" callbacks for all devices.
869 * @state: PM transition of the system being carried out.
870 */
871void dpm_resume_early(pm_message_t state)
872{
873 struct device *dev;
874 ktime_t starttime = ktime_get();
875
876 trace_suspend_resume(TPS("dpm_resume_early"), state.event, true);
877 mutex_lock(&dpm_list_mtx);
878 pm_transition = state;
879
880 /*
881 * Advanced the async threads upfront,
882 * in case the starting of async threads is
883 * delayed by non-async resuming devices.
884 */
885 list_for_each_entry(dev, &dpm_late_early_list, power.entry) {
886 reinit_completion(&dev->power.completion);
887 if (is_async(dev)) {
888 get_device(dev);
889 async_schedule(async_resume_early, dev);
890 }
891 }
892
893 while (!list_empty(&dpm_late_early_list)) {
894 dev = to_device(dpm_late_early_list.next);
895 get_device(dev);
896 list_move_tail(&dev->power.entry, &dpm_suspended_list);
897 mutex_unlock(&dpm_list_mtx);
898
899 if (!is_async(dev)) {
900 int error;
901
902 error = device_resume_early(dev, state, false);
903 if (error) {
904 suspend_stats.failed_resume_early++;
905 dpm_save_failed_step(SUSPEND_RESUME_EARLY);
906 dpm_save_failed_dev(dev_name(dev));
907 pm_dev_err(dev, state, " early", error);
908 }
909 }
910 mutex_lock(&dpm_list_mtx);
911 put_device(dev);
912 }
913 mutex_unlock(&dpm_list_mtx);
914 async_synchronize_full();
915 dpm_show_time(starttime, state, 0, "early");
916 trace_suspend_resume(TPS("dpm_resume_early"), state.event, false);
917}
918
919/**
920 * dpm_resume_start - Execute "noirq" and "early" device callbacks.
921 * @state: PM transition of the system being carried out.
922 */
923void dpm_resume_start(pm_message_t state)
924{
925 dpm_resume_noirq(state);
926 dpm_resume_early(state);
927}
928EXPORT_SYMBOL_GPL(dpm_resume_start);
929
930/**
931 * device_resume - Execute "resume" callbacks for given device.
932 * @dev: Device to handle.
933 * @state: PM transition of the system being carried out.
934 * @async: If true, the device is being resumed asynchronously.
935 */
936static int device_resume(struct device *dev, pm_message_t state, bool async)
937{
938 pm_callback_t callback = NULL;
939 const char *info = NULL;
940 int error = 0;
941 DECLARE_DPM_WATCHDOG_ON_STACK(wd);
942
943 TRACE_DEVICE(dev);
944 TRACE_RESUME(0);
945
946 if (dev->power.syscore)
947 goto Complete;
948
949 if (dev->power.direct_complete) {
950 /* Match the pm_runtime_disable() in __device_suspend(). */
951 pm_runtime_enable(dev);
952 goto Complete;
953 }
954
955 dpm_wait_for_superior(dev, async);
956 dpm_watchdog_set(&wd, dev);
957 device_lock(dev);
958
959 /*
960 * This is a fib. But we'll allow new children to be added below
961 * a resumed device, even if the device hasn't been completed yet.
962 */
963 dev->power.is_prepared = false;
964
965 if (!dev->power.is_suspended)
966 goto Unlock;
967
968 if (dev->pm_domain) {
969 info = "power domain ";
970 callback = pm_op(&dev->pm_domain->ops, state);
971 goto Driver;
972 }
973
974 if (dev->type && dev->type->pm) {
975 info = "type ";
976 callback = pm_op(dev->type->pm, state);
977 goto Driver;
978 }
979
980 if (dev->class && dev->class->pm) {
981 info = "class ";
982 callback = pm_op(dev->class->pm, state);
983 goto Driver;
984 }
985
986 if (dev->bus) {
987 if (dev->bus->pm) {
988 info = "bus ";
989 callback = pm_op(dev->bus->pm, state);
990 } else if (dev->bus->resume) {
991 info = "legacy bus ";
992 callback = dev->bus->resume;
993 goto End;
994 }
995 }
996
997 Driver:
998 if (!callback && dev->driver && dev->driver->pm) {
999 info = "driver ";
1000 callback = pm_op(dev->driver->pm, state);
1001 }
1002
1003 End:
1004 error = dpm_run_callback(callback, dev, state, info);
1005 dev->power.is_suspended = false;
1006
1007 Unlock:
1008 device_unlock(dev);
1009 dpm_watchdog_clear(&wd);
1010
1011 Complete:
1012 complete_all(&dev->power.completion);
1013
1014 TRACE_RESUME(error);
1015
1016 return error;
1017}
1018
1019static void async_resume(void *data, async_cookie_t cookie)
1020{
1021 struct device *dev = (struct device *)data;
1022 int error;
1023
1024 error = device_resume(dev, pm_transition, true);
1025 if (error)
1026 pm_dev_err(dev, pm_transition, " async", error);
1027 put_device(dev);
1028}
1029
1030/**
1031 * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
1032 * @state: PM transition of the system being carried out.
1033 *
1034 * Execute the appropriate "resume" callback for all devices whose status
1035 * indicates that they are suspended.
1036 */
1037void dpm_resume(pm_message_t state)
1038{
1039 struct device *dev;
1040 ktime_t starttime = ktime_get();
1041
1042 trace_suspend_resume(TPS("dpm_resume"), state.event, true);
1043 might_sleep();
1044
1045 mutex_lock(&dpm_list_mtx);
1046 pm_transition = state;
1047 async_error = 0;
1048
1049 list_for_each_entry(dev, &dpm_suspended_list, power.entry) {
1050 reinit_completion(&dev->power.completion);
1051 if (is_async(dev)) {
1052 get_device(dev);
1053 async_schedule(async_resume, dev);
1054 }
1055 }
1056
1057 while (!list_empty(&dpm_suspended_list)) {
1058 dev = to_device(dpm_suspended_list.next);
1059 get_device(dev);
1060 if (!is_async(dev)) {
1061 int error;
1062
1063 mutex_unlock(&dpm_list_mtx);
1064
1065 error = device_resume(dev, state, false);
1066 if (error) {
1067 suspend_stats.failed_resume++;
1068 dpm_save_failed_step(SUSPEND_RESUME);
1069 dpm_save_failed_dev(dev_name(dev));
1070 pm_dev_err(dev, state, "", error);
1071 }
1072
1073 mutex_lock(&dpm_list_mtx);
1074 }
1075 if (!list_empty(&dev->power.entry))
1076 list_move_tail(&dev->power.entry, &dpm_prepared_list);
1077 put_device(dev);
1078 }
1079 mutex_unlock(&dpm_list_mtx);
1080 async_synchronize_full();
1081 dpm_show_time(starttime, state, 0, NULL);
1082
1083 cpufreq_resume();
1084 trace_suspend_resume(TPS("dpm_resume"), state.event, false);
1085}
1086
1087/**
1088 * device_complete - Complete a PM transition for given device.
1089 * @dev: Device to handle.
1090 * @state: PM transition of the system being carried out.
1091 */
1092static void device_complete(struct device *dev, pm_message_t state)
1093{
1094 void (*callback)(struct device *) = NULL;
1095 const char *info = NULL;
1096
1097 if (dev->power.syscore)
1098 return;
1099
1100 device_lock(dev);
1101
1102 if (dev->pm_domain) {
1103 info = "completing power domain ";
1104 callback = dev->pm_domain->ops.complete;
1105 } else if (dev->type && dev->type->pm) {
1106 info = "completing type ";
1107 callback = dev->type->pm->complete;
1108 } else if (dev->class && dev->class->pm) {
1109 info = "completing class ";
1110 callback = dev->class->pm->complete;
1111 } else if (dev->bus && dev->bus->pm) {
1112 info = "completing bus ";
1113 callback = dev->bus->pm->complete;
1114 }
1115
1116 if (!callback && dev->driver && dev->driver->pm) {
1117 info = "completing driver ";
1118 callback = dev->driver->pm->complete;
1119 }
1120
1121 if (callback) {
1122 pm_dev_dbg(dev, state, info);
1123 callback(dev);
1124 }
1125
1126 device_unlock(dev);
1127
1128 pm_runtime_put(dev);
1129}
1130
1131/**
1132 * dpm_complete - Complete a PM transition for all non-sysdev devices.
1133 * @state: PM transition of the system being carried out.
1134 *
1135 * Execute the ->complete() callbacks for all devices whose PM status is not
1136 * DPM_ON (this allows new devices to be registered).
1137 */
1138void dpm_complete(pm_message_t state)
1139{
1140 struct list_head list;
1141
1142 trace_suspend_resume(TPS("dpm_complete"), state.event, true);
1143 might_sleep();
1144
1145 INIT_LIST_HEAD(&list);
1146 mutex_lock(&dpm_list_mtx);
1147 while (!list_empty(&dpm_prepared_list)) {
1148 struct device *dev = to_device(dpm_prepared_list.prev);
1149
1150 get_device(dev);
1151 dev->power.is_prepared = false;
1152 list_move(&dev->power.entry, &list);
1153 mutex_unlock(&dpm_list_mtx);
1154
1155 trace_device_pm_callback_start(dev, "", state.event);
1156 device_complete(dev, state);
1157 trace_device_pm_callback_end(dev, 0);
1158
1159 mutex_lock(&dpm_list_mtx);
1160 put_device(dev);
1161 }
1162 list_splice(&list, &dpm_list);
1163 mutex_unlock(&dpm_list_mtx);
1164
1165 /* Allow device probing and trigger re-probing of deferred devices */
1166 device_unblock_probing();
1167 trace_suspend_resume(TPS("dpm_complete"), state.event, false);
1168}
1169
1170/**
1171 * dpm_resume_end - Execute "resume" callbacks and complete system transition.
1172 * @state: PM transition of the system being carried out.
1173 *
1174 * Execute "resume" callbacks for all devices and complete the PM transition of
1175 * the system.
1176 */
1177void dpm_resume_end(pm_message_t state)
1178{
1179 dpm_resume(state);
1180 dpm_complete(state);
1181}
1182EXPORT_SYMBOL_GPL(dpm_resume_end);
1183
1184
1185/*------------------------- Suspend routines -------------------------*/
1186
1187/**
1188 * resume_event - Return a "resume" message for given "suspend" sleep state.
1189 * @sleep_state: PM message representing a sleep state.
1190 *
1191 * Return a PM message representing the resume event corresponding to given
1192 * sleep state.
1193 */
1194static pm_message_t resume_event(pm_message_t sleep_state)
1195{
1196 switch (sleep_state.event) {
1197 case PM_EVENT_SUSPEND:
1198 return PMSG_RESUME;
1199 case PM_EVENT_FREEZE:
1200 case PM_EVENT_QUIESCE:
1201 return PMSG_RECOVER;
1202 case PM_EVENT_HIBERNATE:
1203 return PMSG_RESTORE;
1204 }
1205 return PMSG_ON;
1206}
1207
1208static void dpm_superior_set_must_resume(struct device *dev)
1209{
1210 struct device_link *link;
1211 int idx;
1212
1213 if (dev->parent)
1214 dev->parent->power.must_resume = true;
1215
1216 idx = device_links_read_lock();
1217
1218 list_for_each_entry_rcu(link, &dev->links.suppliers, c_node)
1219 link->supplier->power.must_resume = true;
1220
1221 device_links_read_unlock(idx);
1222}
1223
1224static pm_callback_t dpm_subsys_suspend_noirq_cb(struct device *dev,
1225 pm_message_t state,
1226 const char **info_p)
1227{
1228 pm_callback_t callback;
1229 const char *info;
1230
1231 if (dev->pm_domain) {
1232 info = "noirq power domain ";
1233 callback = pm_noirq_op(&dev->pm_domain->ops, state);
1234 } else if (dev->type && dev->type->pm) {
1235 info = "noirq type ";
1236 callback = pm_noirq_op(dev->type->pm, state);
1237 } else if (dev->class && dev->class->pm) {
1238 info = "noirq class ";
1239 callback = pm_noirq_op(dev->class->pm, state);
1240 } else if (dev->bus && dev->bus->pm) {
1241 info = "noirq bus ";
1242 callback = pm_noirq_op(dev->bus->pm, state);
1243 } else {
1244 return NULL;
1245 }
1246
1247 if (info_p)
1248 *info_p = info;
1249
1250 return callback;
1251}
1252
1253static bool device_must_resume(struct device *dev, pm_message_t state,
1254 bool no_subsys_suspend_noirq)
1255{
1256 pm_message_t resume_msg = resume_event(state);
1257
1258 /*
1259 * If all of the device driver's "noirq", "late" and "early" callbacks
1260 * are invoked directly by the core, the decision to allow the device to
1261 * stay in suspend can be based on its current runtime PM status and its
1262 * wakeup settings.
1263 */
1264 if (no_subsys_suspend_noirq &&
1265 !dpm_subsys_suspend_late_cb(dev, state, NULL) &&
1266 !dpm_subsys_resume_early_cb(dev, resume_msg, NULL) &&
1267 !dpm_subsys_resume_noirq_cb(dev, resume_msg, NULL))
1268 return !pm_runtime_status_suspended(dev) &&
1269 (resume_msg.event != PM_EVENT_RESUME ||
1270 (device_can_wakeup(dev) && !device_may_wakeup(dev)));
1271
1272 /*
1273 * The only safe strategy here is to require that if the device may not
1274 * be left in suspend, resume callbacks must be invoked for it.
1275 */
1276 return !dev->power.may_skip_resume;
1277}
1278
1279/**
1280 * __device_suspend_noirq - Execute a "noirq suspend" callback for given device.
1281 * @dev: Device to handle.
1282 * @state: PM transition of the system being carried out.
1283 * @async: If true, the device is being suspended asynchronously.
1284 *
1285 * The driver of @dev will not receive interrupts while this function is being
1286 * executed.
1287 */
1288static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool async)
1289{
1290 pm_callback_t callback;
1291 const char *info;
1292 bool no_subsys_cb = false;
1293 int error = 0;
1294
1295 TRACE_DEVICE(dev);
1296 TRACE_SUSPEND(0);
1297
1298 dpm_wait_for_subordinate(dev, async);
1299
1300 if (async_error)
1301 goto Complete;
1302
1303 if (pm_wakeup_pending()) {
1304 async_error = -EBUSY;
1305 goto Complete;
1306 }
1307
1308 if (dev->power.syscore || dev->power.direct_complete)
1309 goto Complete;
1310
1311 callback = dpm_subsys_suspend_noirq_cb(dev, state, &info);
1312 if (callback)
1313 goto Run;
1314
1315 no_subsys_cb = !dpm_subsys_suspend_late_cb(dev, state, NULL);
1316
1317 if (dev_pm_smart_suspend_and_suspended(dev) && no_subsys_cb)
1318 goto Skip;
1319
1320 if (dev->driver && dev->driver->pm) {
1321 info = "noirq driver ";
1322 callback = pm_noirq_op(dev->driver->pm, state);
1323 }
1324
1325Run:
1326 error = dpm_run_callback(callback, dev, state, info);
1327 if (error) {
1328 async_error = error;
1329 goto Complete;
1330 }
1331
1332Skip:
1333 dev->power.is_noirq_suspended = true;
1334
1335 if (dev_pm_test_driver_flags(dev, DPM_FLAG_LEAVE_SUSPENDED)) {
1336 dev->power.must_resume = dev->power.must_resume ||
1337 atomic_read(&dev->power.usage_count) > 1 ||
1338 device_must_resume(dev, state, no_subsys_cb);
1339 } else {
1340 dev->power.must_resume = true;
1341 }
1342
1343 if (dev->power.must_resume)
1344 dpm_superior_set_must_resume(dev);
1345
1346Complete:
1347 complete_all(&dev->power.completion);
1348 TRACE_SUSPEND(error);
1349 return error;
1350}
1351
1352static void async_suspend_noirq(void *data, async_cookie_t cookie)
1353{
1354 struct device *dev = (struct device *)data;
1355 int error;
1356
1357 error = __device_suspend_noirq(dev, pm_transition, true);
1358 if (error) {
1359 dpm_save_failed_dev(dev_name(dev));
1360 pm_dev_err(dev, pm_transition, " async", error);
1361 }
1362
1363 put_device(dev);
1364}
1365
1366static int device_suspend_noirq(struct device *dev)
1367{
1368 reinit_completion(&dev->power.completion);
1369
1370 if (is_async(dev)) {
1371 get_device(dev);
1372 async_schedule(async_suspend_noirq, dev);
1373 return 0;
1374 }
1375 return __device_suspend_noirq(dev, pm_transition, false);
1376}
1377
1378void dpm_noirq_begin(void)
1379{
1380 cpuidle_pause();
1381 device_wakeup_arm_wake_irqs();
1382 suspend_device_irqs();
1383}
1384
1385int dpm_noirq_suspend_devices(pm_message_t state)
1386{
1387 ktime_t starttime = ktime_get();
1388 int error = 0;
1389
1390 trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, true);
1391 mutex_lock(&dpm_list_mtx);
1392 pm_transition = state;
1393 async_error = 0;
1394
1395 while (!list_empty(&dpm_late_early_list)) {
1396 struct device *dev = to_device(dpm_late_early_list.prev);
1397
1398 get_device(dev);
1399 mutex_unlock(&dpm_list_mtx);
1400
1401 error = device_suspend_noirq(dev);
1402
1403 mutex_lock(&dpm_list_mtx);
1404 if (error) {
1405 pm_dev_err(dev, state, " noirq", error);
1406 dpm_save_failed_dev(dev_name(dev));
1407 put_device(dev);
1408 break;
1409 }
1410 if (!list_empty(&dev->power.entry))
1411 list_move(&dev->power.entry, &dpm_noirq_list);
1412 put_device(dev);
1413
1414 if (async_error)
1415 break;
1416 }
1417 mutex_unlock(&dpm_list_mtx);
1418 async_synchronize_full();
1419 if (!error)
1420 error = async_error;
1421
1422 if (error) {
1423 suspend_stats.failed_suspend_noirq++;
1424 dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ);
1425 }
1426 dpm_show_time(starttime, state, error, "noirq");
1427 trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, false);
1428 return error;
1429}
1430
1431/**
1432 * dpm_suspend_noirq - Execute "noirq suspend" callbacks for all devices.
1433 * @state: PM transition of the system being carried out.
1434 *
1435 * Prevent device drivers' interrupt handlers from being called and invoke
1436 * "noirq" suspend callbacks for all non-sysdev devices.
1437 */
1438int dpm_suspend_noirq(pm_message_t state)
1439{
1440 int ret;
1441
1442 dpm_noirq_begin();
1443 ret = dpm_noirq_suspend_devices(state);
1444 if (ret)
1445 dpm_resume_noirq(resume_event(state));
1446
1447 return ret;
1448}
1449
1450static void dpm_propagate_wakeup_to_parent(struct device *dev)
1451{
1452 struct device *parent = dev->parent;
1453
1454 if (!parent)
1455 return;
1456
1457 spin_lock_irq(&parent->power.lock);
1458
1459 if (dev->power.wakeup_path && !parent->power.ignore_children)
1460 parent->power.wakeup_path = true;
1461
1462 spin_unlock_irq(&parent->power.lock);
1463}
1464
1465static pm_callback_t dpm_subsys_suspend_late_cb(struct device *dev,
1466 pm_message_t state,
1467 const char **info_p)
1468{
1469 pm_callback_t callback;
1470 const char *info;
1471
1472 if (dev->pm_domain) {
1473 info = "late power domain ";
1474 callback = pm_late_early_op(&dev->pm_domain->ops, state);
1475 } else if (dev->type && dev->type->pm) {
1476 info = "late type ";
1477 callback = pm_late_early_op(dev->type->pm, state);
1478 } else if (dev->class && dev->class->pm) {
1479 info = "late class ";
1480 callback = pm_late_early_op(dev->class->pm, state);
1481 } else if (dev->bus && dev->bus->pm) {
1482 info = "late bus ";
1483 callback = pm_late_early_op(dev->bus->pm, state);
1484 } else {
1485 return NULL;
1486 }
1487
1488 if (info_p)
1489 *info_p = info;
1490
1491 return callback;
1492}
1493
1494/**
1495 * __device_suspend_late - Execute a "late suspend" callback for given device.
1496 * @dev: Device to handle.
1497 * @state: PM transition of the system being carried out.
1498 * @async: If true, the device is being suspended asynchronously.
1499 *
1500 * Runtime PM is disabled for @dev while this function is being executed.
1501 */
1502static int __device_suspend_late(struct device *dev, pm_message_t state, bool async)
1503{
1504 pm_callback_t callback;
1505 const char *info;
1506 int error = 0;
1507
1508 TRACE_DEVICE(dev);
1509 TRACE_SUSPEND(0);
1510
1511 __pm_runtime_disable(dev, false);
1512
1513 dpm_wait_for_subordinate(dev, async);
1514
1515 if (async_error)
1516 goto Complete;
1517
1518 if (pm_wakeup_pending()) {
1519 async_error = -EBUSY;
1520 goto Complete;
1521 }
1522
1523 if (dev->power.syscore || dev->power.direct_complete)
1524 goto Complete;
1525
1526 callback = dpm_subsys_suspend_late_cb(dev, state, &info);
1527 if (callback)
1528 goto Run;
1529
1530 if (dev_pm_smart_suspend_and_suspended(dev) &&
1531 !dpm_subsys_suspend_noirq_cb(dev, state, NULL))
1532 goto Skip;
1533
1534 if (dev->driver && dev->driver->pm) {
1535 info = "late driver ";
1536 callback = pm_late_early_op(dev->driver->pm, state);
1537 }
1538
1539Run:
1540 error = dpm_run_callback(callback, dev, state, info);
1541 if (error) {
1542 async_error = error;
1543 goto Complete;
1544 }
1545 dpm_propagate_wakeup_to_parent(dev);
1546
1547Skip:
1548 dev->power.is_late_suspended = true;
1549
1550Complete:
1551 TRACE_SUSPEND(error);
1552 complete_all(&dev->power.completion);
1553 return error;
1554}
1555
1556static void async_suspend_late(void *data, async_cookie_t cookie)
1557{
1558 struct device *dev = (struct device *)data;
1559 int error;
1560
1561 error = __device_suspend_late(dev, pm_transition, true);
1562 if (error) {
1563 dpm_save_failed_dev(dev_name(dev));
1564 pm_dev_err(dev, pm_transition, " async", error);
1565 }
1566 put_device(dev);
1567}
1568
1569static int device_suspend_late(struct device *dev)
1570{
1571 reinit_completion(&dev->power.completion);
1572
1573 if (is_async(dev)) {
1574 get_device(dev);
1575 async_schedule(async_suspend_late, dev);
1576 return 0;
1577 }
1578
1579 return __device_suspend_late(dev, pm_transition, false);
1580}
1581
1582/**
1583 * dpm_suspend_late - Execute "late suspend" callbacks for all devices.
1584 * @state: PM transition of the system being carried out.
1585 */
1586int dpm_suspend_late(pm_message_t state)
1587{
1588 ktime_t starttime = ktime_get();
1589 int error = 0;
1590
1591 trace_suspend_resume(TPS("dpm_suspend_late"), state.event, true);
1592 mutex_lock(&dpm_list_mtx);
1593 pm_transition = state;
1594 async_error = 0;
1595
1596 while (!list_empty(&dpm_suspended_list)) {
1597 struct device *dev = to_device(dpm_suspended_list.prev);
1598
1599 get_device(dev);
1600 mutex_unlock(&dpm_list_mtx);
1601
1602 error = device_suspend_late(dev);
1603
1604 mutex_lock(&dpm_list_mtx);
1605 if (!list_empty(&dev->power.entry))
1606 list_move(&dev->power.entry, &dpm_late_early_list);
1607
1608 if (error) {
1609 pm_dev_err(dev, state, " late", error);
1610 dpm_save_failed_dev(dev_name(dev));
1611 put_device(dev);
1612 break;
1613 }
1614 put_device(dev);
1615
1616 if (async_error)
1617 break;
1618 }
1619 mutex_unlock(&dpm_list_mtx);
1620 async_synchronize_full();
1621 if (!error)
1622 error = async_error;
1623 if (error) {
1624 suspend_stats.failed_suspend_late++;
1625 dpm_save_failed_step(SUSPEND_SUSPEND_LATE);
1626 dpm_resume_early(resume_event(state));
1627 }
1628 dpm_show_time(starttime, state, error, "late");
1629 trace_suspend_resume(TPS("dpm_suspend_late"), state.event, false);
1630 return error;
1631}
1632
1633/**
1634 * dpm_suspend_end - Execute "late" and "noirq" device suspend callbacks.
1635 * @state: PM transition of the system being carried out.
1636 */
1637int dpm_suspend_end(pm_message_t state)
1638{
1639 int error = dpm_suspend_late(state);
1640 if (error)
1641 return error;
1642
1643 error = dpm_suspend_noirq(state);
1644 if (error) {
1645 dpm_resume_early(resume_event(state));
1646 return error;
1647 }
1648
1649 return 0;
1650}
1651EXPORT_SYMBOL_GPL(dpm_suspend_end);
1652
1653/**
1654 * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
1655 * @dev: Device to suspend.
1656 * @state: PM transition of the system being carried out.
1657 * @cb: Suspend callback to execute.
1658 * @info: string description of caller.
1659 */
1660static int legacy_suspend(struct device *dev, pm_message_t state,
1661 int (*cb)(struct device *dev, pm_message_t state),
1662 const char *info)
1663{
1664 int error;
1665 ktime_t calltime;
1666
1667 calltime = initcall_debug_start(dev);
1668
1669 trace_device_pm_callback_start(dev, info, state.event);
1670 error = cb(dev, state);
1671 trace_device_pm_callback_end(dev, error);
1672 suspend_report_result(cb, error);
1673
1674 initcall_debug_report(dev, calltime, error, state, info);
1675
1676 return error;
1677}
1678
1679static void dpm_clear_superiors_direct_complete(struct device *dev)
1680{
1681 struct device_link *link;
1682 int idx;
1683
1684 if (dev->parent) {
1685 spin_lock_irq(&dev->parent->power.lock);
1686 dev->parent->power.direct_complete = false;
1687 spin_unlock_irq(&dev->parent->power.lock);
1688 }
1689
1690 idx = device_links_read_lock();
1691
1692 list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) {
1693 spin_lock_irq(&link->supplier->power.lock);
1694 link->supplier->power.direct_complete = false;
1695 spin_unlock_irq(&link->supplier->power.lock);
1696 }
1697
1698 device_links_read_unlock(idx);
1699}
1700
1701/**
1702 * __device_suspend - Execute "suspend" callbacks for given device.
1703 * @dev: Device to handle.
1704 * @state: PM transition of the system being carried out.
1705 * @async: If true, the device is being suspended asynchronously.
1706 */
1707static int __device_suspend(struct device *dev, pm_message_t state, bool async)
1708{
1709 pm_callback_t callback = NULL;
1710 const char *info = NULL;
1711 int error = 0;
1712 DECLARE_DPM_WATCHDOG_ON_STACK(wd);
1713
1714 TRACE_DEVICE(dev);
1715 TRACE_SUSPEND(0);
1716
1717 dpm_wait_for_subordinate(dev, async);
1718
1719 if (async_error)
1720 goto Complete;
1721
1722 /*
1723 * If a device configured to wake up the system from sleep states
1724 * has been suspended at run time and there's a resume request pending
1725 * for it, this is equivalent to the device signaling wakeup, so the
1726 * system suspend operation should be aborted.
1727 */
1728 if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
1729 pm_wakeup_event(dev, 0);
1730
1731 if (pm_wakeup_pending()) {
1732 async_error = -EBUSY;
1733 goto Complete;
1734 }
1735
1736 if (dev->power.syscore)
1737 goto Complete;
1738
1739 if (dev->power.direct_complete) {
1740 if (pm_runtime_status_suspended(dev)) {
1741 pm_runtime_disable(dev);
1742 if (pm_runtime_status_suspended(dev))
1743 goto Complete;
1744
1745 pm_runtime_enable(dev);
1746 }
1747 dev->power.direct_complete = false;
1748 }
1749
1750 dev->power.may_skip_resume = false;
1751 dev->power.must_resume = false;
1752
1753 dpm_watchdog_set(&wd, dev);
1754 device_lock(dev);
1755
1756 if (dev->pm_domain) {
1757 info = "power domain ";
1758 callback = pm_op(&dev->pm_domain->ops, state);
1759 goto Run;
1760 }
1761
1762 if (dev->type && dev->type->pm) {
1763 info = "type ";
1764 callback = pm_op(dev->type->pm, state);
1765 goto Run;
1766 }
1767
1768 if (dev->class && dev->class->pm) {
1769 info = "class ";
1770 callback = pm_op(dev->class->pm, state);
1771 goto Run;
1772 }
1773
1774 if (dev->bus) {
1775 if (dev->bus->pm) {
1776 info = "bus ";
1777 callback = pm_op(dev->bus->pm, state);
1778 } else if (dev->bus->suspend) {
1779 pm_dev_dbg(dev, state, "legacy bus ");
1780 error = legacy_suspend(dev, state, dev->bus->suspend,
1781 "legacy bus ");
1782 goto End;
1783 }
1784 }
1785
1786 Run:
1787 if (!callback && dev->driver && dev->driver->pm) {
1788 info = "driver ";
1789 callback = pm_op(dev->driver->pm, state);
1790 }
1791
1792 error = dpm_run_callback(callback, dev, state, info);
1793
1794 End:
1795 if (!error) {
1796 dev->power.is_suspended = true;
1797 if (device_may_wakeup(dev))
1798 dev->power.wakeup_path = true;
1799
1800 dpm_propagate_wakeup_to_parent(dev);
1801 dpm_clear_superiors_direct_complete(dev);
1802 }
1803
1804 device_unlock(dev);
1805 dpm_watchdog_clear(&wd);
1806
1807 Complete:
1808 if (error)
1809 async_error = error;
1810
1811 complete_all(&dev->power.completion);
1812 TRACE_SUSPEND(error);
1813 return error;
1814}
1815
1816static void async_suspend(void *data, async_cookie_t cookie)
1817{
1818 struct device *dev = (struct device *)data;
1819 int error;
1820
1821 error = __device_suspend(dev, pm_transition, true);
1822 if (error) {
1823 dpm_save_failed_dev(dev_name(dev));
1824 pm_dev_err(dev, pm_transition, " async", error);
1825 }
1826
1827 put_device(dev);
1828}
1829
1830static int device_suspend(struct device *dev)
1831{
1832 reinit_completion(&dev->power.completion);
1833
1834 if (is_async(dev)) {
1835 get_device(dev);
1836 async_schedule(async_suspend, dev);
1837 return 0;
1838 }
1839
1840 return __device_suspend(dev, pm_transition, false);
1841}
1842
1843/**
1844 * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
1845 * @state: PM transition of the system being carried out.
1846 */
1847int dpm_suspend(pm_message_t state)
1848{
1849 ktime_t starttime = ktime_get();
1850 int error = 0;
1851
1852 trace_suspend_resume(TPS("dpm_suspend"), state.event, true);
1853 might_sleep();
1854
1855 cpufreq_suspend();
1856
1857 mutex_lock(&dpm_list_mtx);
1858 pm_transition = state;
1859 async_error = 0;
1860 while (!list_empty(&dpm_prepared_list)) {
1861 struct device *dev = to_device(dpm_prepared_list.prev);
1862
1863 get_device(dev);
1864 mutex_unlock(&dpm_list_mtx);
1865
1866 error = device_suspend(dev);
1867
1868 mutex_lock(&dpm_list_mtx);
1869 if (error) {
1870 pm_dev_err(dev, state, "", error);
1871 dpm_save_failed_dev(dev_name(dev));
1872 put_device(dev);
1873 break;
1874 }
1875 if (!list_empty(&dev->power.entry))
1876 list_move(&dev->power.entry, &dpm_suspended_list);
1877 put_device(dev);
1878 if (async_error)
1879 break;
1880 }
1881 mutex_unlock(&dpm_list_mtx);
1882 async_synchronize_full();
1883 if (!error)
1884 error = async_error;
1885 if (error) {
1886 suspend_stats.failed_suspend++;
1887 dpm_save_failed_step(SUSPEND_SUSPEND);
1888 }
1889 dpm_show_time(starttime, state, error, NULL);
1890 trace_suspend_resume(TPS("dpm_suspend"), state.event, false);
1891 return error;
1892}
1893
1894/**
1895 * device_prepare - Prepare a device for system power transition.
1896 * @dev: Device to handle.
1897 * @state: PM transition of the system being carried out.
1898 *
1899 * Execute the ->prepare() callback(s) for given device. No new children of the
1900 * device may be registered after this function has returned.
1901 */
1902static int device_prepare(struct device *dev, pm_message_t state)
1903{
1904 int (*callback)(struct device *) = NULL;
1905 int ret = 0;
1906
1907 if (dev->power.syscore)
1908 return 0;
1909
1910 WARN_ON(!pm_runtime_enabled(dev) &&
1911 dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND |
1912 DPM_FLAG_LEAVE_SUSPENDED));
1913
1914 /*
1915 * If a device's parent goes into runtime suspend at the wrong time,
1916 * it won't be possible to resume the device. To prevent this we
1917 * block runtime suspend here, during the prepare phase, and allow
1918 * it again during the complete phase.
1919 */
1920 pm_runtime_get_noresume(dev);
1921
1922 device_lock(dev);
1923
1924 dev->power.wakeup_path = false;
1925
1926 if (dev->power.no_pm_callbacks)
1927 goto unlock;
1928
1929 if (dev->pm_domain)
1930 callback = dev->pm_domain->ops.prepare;
1931 else if (dev->type && dev->type->pm)
1932 callback = dev->type->pm->prepare;
1933 else if (dev->class && dev->class->pm)
1934 callback = dev->class->pm->prepare;
1935 else if (dev->bus && dev->bus->pm)
1936 callback = dev->bus->pm->prepare;
1937
1938 if (!callback && dev->driver && dev->driver->pm)
1939 callback = dev->driver->pm->prepare;
1940
1941 if (callback)
1942 ret = callback(dev);
1943
1944unlock:
1945 device_unlock(dev);
1946
1947 if (ret < 0) {
1948 suspend_report_result(callback, ret);
1949 pm_runtime_put(dev);
1950 return ret;
1951 }
1952 /*
1953 * A positive return value from ->prepare() means "this device appears
1954 * to be runtime-suspended and its state is fine, so if it really is
1955 * runtime-suspended, you can leave it in that state provided that you
1956 * will do the same thing with all of its descendants". This only
1957 * applies to suspend transitions, however.
1958 */
1959 spin_lock_irq(&dev->power.lock);
1960 dev->power.direct_complete = state.event == PM_EVENT_SUSPEND &&
1961 ((pm_runtime_suspended(dev) && ret > 0) ||
1962 dev->power.no_pm_callbacks) &&
1963 !dev_pm_test_driver_flags(dev, DPM_FLAG_NEVER_SKIP);
1964 spin_unlock_irq(&dev->power.lock);
1965 return 0;
1966}
1967
1968/**
1969 * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1970 * @state: PM transition of the system being carried out.
1971 *
1972 * Execute the ->prepare() callback(s) for all devices.
1973 */
1974int dpm_prepare(pm_message_t state)
1975{
1976 int error = 0;
1977
1978 trace_suspend_resume(TPS("dpm_prepare"), state.event, true);
1979 might_sleep();
1980
1981 /*
1982 * Give a chance for the known devices to complete their probes, before
1983 * disable probing of devices. This sync point is important at least
1984 * at boot time + hibernation restore.
1985 */
1986 wait_for_device_probe();
1987 /*
1988 * It is unsafe if probing of devices will happen during suspend or
1989 * hibernation and system behavior will be unpredictable in this case.
1990 * So, let's prohibit device's probing here and defer their probes
1991 * instead. The normal behavior will be restored in dpm_complete().
1992 */
1993 device_block_probing();
1994
1995 mutex_lock(&dpm_list_mtx);
1996 while (!list_empty(&dpm_list)) {
1997 struct device *dev = to_device(dpm_list.next);
1998
1999 get_device(dev);
2000 mutex_unlock(&dpm_list_mtx);
2001
2002 trace_device_pm_callback_start(dev, "", state.event);
2003 error = device_prepare(dev, state);
2004 trace_device_pm_callback_end(dev, error);
2005
2006 mutex_lock(&dpm_list_mtx);
2007 if (error) {
2008 if (error == -EAGAIN) {
2009 put_device(dev);
2010 error = 0;
2011 continue;
2012 }
2013 printk(KERN_INFO "PM: Device %s not prepared "
2014 "for power transition: code %d\n",
2015 dev_name(dev), error);
2016 put_device(dev);
2017 break;
2018 }
2019 dev->power.is_prepared = true;
2020 if (!list_empty(&dev->power.entry))
2021 list_move_tail(&dev->power.entry, &dpm_prepared_list);
2022 put_device(dev);
2023 }
2024 mutex_unlock(&dpm_list_mtx);
2025 trace_suspend_resume(TPS("dpm_prepare"), state.event, false);
2026 return error;
2027}
2028
2029/**
2030 * dpm_suspend_start - Prepare devices for PM transition and suspend them.
2031 * @state: PM transition of the system being carried out.
2032 *
2033 * Prepare all non-sysdev devices for system PM transition and execute "suspend"
2034 * callbacks for them.
2035 */
2036int dpm_suspend_start(pm_message_t state)
2037{
2038 int error;
2039
2040 error = dpm_prepare(state);
2041 if (error) {
2042 suspend_stats.failed_prepare++;
2043 dpm_save_failed_step(SUSPEND_PREPARE);
2044 } else
2045 error = dpm_suspend(state);
2046 return error;
2047}
2048EXPORT_SYMBOL_GPL(dpm_suspend_start);
2049
2050void __suspend_report_result(const char *function, void *fn, int ret)
2051{
2052 if (ret)
2053 printk(KERN_ERR "%s(): %pF returns %d\n", function, fn, ret);
2054}
2055EXPORT_SYMBOL_GPL(__suspend_report_result);
2056
2057/**
2058 * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
2059 * @dev: Device to wait for.
2060 * @subordinate: Device that needs to wait for @dev.
2061 */
2062int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
2063{
2064 dpm_wait(dev, subordinate->power.async_suspend);
2065 return async_error;
2066}
2067EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);
2068
2069/**
2070 * dpm_for_each_dev - device iterator.
2071 * @data: data for the callback.
2072 * @fn: function to be called for each device.
2073 *
2074 * Iterate over devices in dpm_list, and call @fn for each device,
2075 * passing it @data.
2076 */
2077void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *))
2078{
2079 struct device *dev;
2080
2081 if (!fn)
2082 return;
2083
2084 device_pm_lock();
2085 list_for_each_entry(dev, &dpm_list, power.entry)
2086 fn(dev, data);
2087 device_pm_unlock();
2088}
2089EXPORT_SYMBOL_GPL(dpm_for_each_dev);
2090
2091static bool pm_ops_is_empty(const struct dev_pm_ops *ops)
2092{
2093 if (!ops)
2094 return true;
2095
2096 return !ops->prepare &&
2097 !ops->suspend &&
2098 !ops->suspend_late &&
2099 !ops->suspend_noirq &&
2100 !ops->resume_noirq &&
2101 !ops->resume_early &&
2102 !ops->resume &&
2103 !ops->complete;
2104}
2105
2106void device_pm_check_callbacks(struct device *dev)
2107{
2108 spin_lock_irq(&dev->power.lock);
2109 dev->power.no_pm_callbacks =
2110 (!dev->bus || (pm_ops_is_empty(dev->bus->pm) &&
2111 !dev->bus->suspend && !dev->bus->resume)) &&
2112 (!dev->class || pm_ops_is_empty(dev->class->pm)) &&
2113 (!dev->type || pm_ops_is_empty(dev->type->pm)) &&
2114 (!dev->pm_domain || pm_ops_is_empty(&dev->pm_domain->ops)) &&
2115 (!dev->driver || (pm_ops_is_empty(dev->driver->pm) &&
2116 !dev->driver->suspend && !dev->driver->resume));
2117 spin_unlock_irq(&dev->power.lock);
2118}
2119
2120bool dev_pm_smart_suspend_and_suspended(struct device *dev)
2121{
2122 return dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) &&
2123 pm_runtime_status_suspended(dev);
2124}