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