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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
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
41 typedef 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
53 LIST_HEAD(dpm_list);
54 static LIST_HEAD(dpm_prepared_list);
55 static LIST_HEAD(dpm_suspended_list);
56 static LIST_HEAD(dpm_late_early_list);
57 static LIST_HEAD(dpm_noirq_list);
58
59 struct suspend_stats suspend_stats;
60 static DEFINE_MUTEX(dpm_list_mtx);
61 static pm_message_t pm_transition;
62
63 static int async_error;
64
65 static 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  */
93 void 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  */
108 void 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  */
116 void 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  */
125 void 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  */
147 void 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  */
169 void 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  */
183 void 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  */
196 void 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
203 static 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
214 static 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  */
235 static 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
244 static int dpm_wait_fn(struct device *dev, void *async_ptr)
245 {
246         dpm_wait(dev, *((bool *)async_ptr));
247         return 0;
248 }
249
250 static void dpm_wait_for_children(struct device *dev, bool async)
251 {
252        device_for_each_child(dev, &async, dpm_wait_fn);
253 }
254
255 static 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
276 static bool dpm_wait_for_superior(struct device *dev, bool async)
277 {
278         struct device *parent;
279
280         /*
281          * If the device is resumed asynchronously and the parent's callback
282          * deletes both the device and the parent itself, the parent object may
283          * be freed while this function is running, so avoid that by reference
284          * counting the parent once more unless the device has been deleted
285          * already (in which case return right away).
286          */
287         mutex_lock(&dpm_list_mtx);
288
289         if (!device_pm_initialized(dev)) {
290                 mutex_unlock(&dpm_list_mtx);
291                 return false;
292         }
293
294         parent = get_device(dev->parent);
295
296         mutex_unlock(&dpm_list_mtx);
297
298         dpm_wait(parent, async);
299         put_device(parent);
300
301         dpm_wait_for_suppliers(dev, async);
302
303         /*
304          * If the parent's callback has deleted the device, attempting to resume
305          * it would be invalid, so avoid doing that then.
306          */
307         return device_pm_initialized(dev);
308 }
309
310 static void dpm_wait_for_consumers(struct device *dev, bool async)
311 {
312         struct device_link *link;
313         int idx;
314
315         idx = device_links_read_lock();
316
317         /*
318          * The status of a device link can only be changed from "dormant" by a
319          * probe, but that cannot happen during system suspend/resume.  In
320          * theory it can change to "dormant" at that time, but then it is
321          * reasonable to wait for the target device anyway (eg. if it goes
322          * away, it's better to wait for it to go away completely and then
323          * continue instead of trying to continue in parallel with its
324          * unregistration).
325          */
326         list_for_each_entry_rcu(link, &dev->links.consumers, s_node)
327                 if (READ_ONCE(link->status) != DL_STATE_DORMANT)
328                         dpm_wait(link->consumer, async);
329
330         device_links_read_unlock(idx);
331 }
332
333 static void dpm_wait_for_subordinate(struct device *dev, bool async)
334 {
335         dpm_wait_for_children(dev, async);
336         dpm_wait_for_consumers(dev, async);
337 }
338
339 /**
340  * pm_op - Return the PM operation appropriate for given PM event.
341  * @ops: PM operations to choose from.
342  * @state: PM transition of the system being carried out.
343  */
344 static pm_callback_t pm_op(const struct dev_pm_ops *ops, pm_message_t state)
345 {
346         switch (state.event) {
347 #ifdef CONFIG_SUSPEND
348         case PM_EVENT_SUSPEND:
349                 return ops->suspend;
350         case PM_EVENT_RESUME:
351                 return ops->resume;
352 #endif /* CONFIG_SUSPEND */
353 #ifdef CONFIG_HIBERNATE_CALLBACKS
354         case PM_EVENT_FREEZE:
355         case PM_EVENT_QUIESCE:
356                 return ops->freeze;
357         case PM_EVENT_HIBERNATE:
358                 return ops->poweroff;
359         case PM_EVENT_THAW:
360         case PM_EVENT_RECOVER:
361                 return ops->thaw;
362                 break;
363         case PM_EVENT_RESTORE:
364                 return ops->restore;
365 #endif /* CONFIG_HIBERNATE_CALLBACKS */
366         }
367
368         return NULL;
369 }
370
371 /**
372  * pm_late_early_op - Return the PM operation appropriate for given PM event.
373  * @ops: PM operations to choose from.
374  * @state: PM transition of the system being carried out.
375  *
376  * Runtime PM is disabled for @dev while this function is being executed.
377  */
378 static pm_callback_t pm_late_early_op(const struct dev_pm_ops *ops,
379                                       pm_message_t state)
380 {
381         switch (state.event) {
382 #ifdef CONFIG_SUSPEND
383         case PM_EVENT_SUSPEND:
384                 return ops->suspend_late;
385         case PM_EVENT_RESUME:
386                 return ops->resume_early;
387 #endif /* CONFIG_SUSPEND */
388 #ifdef CONFIG_HIBERNATE_CALLBACKS
389         case PM_EVENT_FREEZE:
390         case PM_EVENT_QUIESCE:
391                 return ops->freeze_late;
392         case PM_EVENT_HIBERNATE:
393                 return ops->poweroff_late;
394         case PM_EVENT_THAW:
395         case PM_EVENT_RECOVER:
396                 return ops->thaw_early;
397         case PM_EVENT_RESTORE:
398                 return ops->restore_early;
399 #endif /* CONFIG_HIBERNATE_CALLBACKS */
400         }
401
402         return NULL;
403 }
404
405 /**
406  * pm_noirq_op - Return the PM operation appropriate for given PM event.
407  * @ops: PM operations to choose from.
408  * @state: PM transition of the system being carried out.
409  *
410  * The driver of @dev will not receive interrupts while this function is being
411  * executed.
412  */
413 static pm_callback_t pm_noirq_op(const struct dev_pm_ops *ops, pm_message_t state)
414 {
415         switch (state.event) {
416 #ifdef CONFIG_SUSPEND
417         case PM_EVENT_SUSPEND:
418                 return ops->suspend_noirq;
419         case PM_EVENT_RESUME:
420                 return ops->resume_noirq;
421 #endif /* CONFIG_SUSPEND */
422 #ifdef CONFIG_HIBERNATE_CALLBACKS
423         case PM_EVENT_FREEZE:
424         case PM_EVENT_QUIESCE:
425                 return ops->freeze_noirq;
426         case PM_EVENT_HIBERNATE:
427                 return ops->poweroff_noirq;
428         case PM_EVENT_THAW:
429         case PM_EVENT_RECOVER:
430                 return ops->thaw_noirq;
431         case PM_EVENT_RESTORE:
432                 return ops->restore_noirq;
433 #endif /* CONFIG_HIBERNATE_CALLBACKS */
434         }
435
436         return NULL;
437 }
438
439 static void pm_dev_dbg(struct device *dev, pm_message_t state, const char *info)
440 {
441         dev_dbg(dev, "%s%s%s\n", info, pm_verb(state.event),
442                 ((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
443                 ", may wakeup" : "");
444 }
445
446 static void pm_dev_err(struct device *dev, pm_message_t state, const char *info,
447                         int error)
448 {
449         pr_err("Device %s failed to %s%s: error %d\n",
450                dev_name(dev), pm_verb(state.event), info, error);
451 }
452
453 static void dpm_show_time(ktime_t starttime, pm_message_t state, int error,
454                           const char *info)
455 {
456         ktime_t calltime;
457         u64 usecs64;
458         int usecs;
459
460         calltime = ktime_get();
461         usecs64 = ktime_to_ns(ktime_sub(calltime, starttime));
462         do_div(usecs64, NSEC_PER_USEC);
463         usecs = usecs64;
464         if (usecs == 0)
465                 usecs = 1;
466
467         pm_pr_dbg("%s%s%s of devices %s after %ld.%03ld msecs\n",
468                   info ?: "", info ? " " : "", pm_verb(state.event),
469                   error ? "aborted" : "complete",
470                   usecs / USEC_PER_MSEC, usecs % USEC_PER_MSEC);
471 }
472
473 static int dpm_run_callback(pm_callback_t cb, struct device *dev,
474                             pm_message_t state, const char *info)
475 {
476         ktime_t calltime;
477         int error;
478
479         if (!cb)
480                 return 0;
481
482         calltime = initcall_debug_start(dev, cb);
483
484         pm_dev_dbg(dev, state, info);
485         trace_device_pm_callback_start(dev, info, state.event);
486         error = cb(dev);
487         trace_device_pm_callback_end(dev, error);
488         suspend_report_result(cb, error);
489
490         initcall_debug_report(dev, calltime, cb, error);
491
492         return error;
493 }
494
495 #ifdef CONFIG_DPM_WATCHDOG
496 struct dpm_watchdog {
497         struct device           *dev;
498         struct task_struct      *tsk;
499         struct timer_list       timer;
500 };
501
502 #define DECLARE_DPM_WATCHDOG_ON_STACK(wd) \
503         struct dpm_watchdog wd
504
505 /**
506  * dpm_watchdog_handler - Driver suspend / resume watchdog handler.
507  * @t: The timer that PM watchdog depends on.
508  *
509  * Called when a driver has timed out suspending or resuming.
510  * There's not much we can do here to recover so panic() to
511  * capture a crash-dump in pstore.
512  */
513 static void dpm_watchdog_handler(struct timer_list *t)
514 {
515         struct dpm_watchdog *wd = from_timer(wd, t, timer);
516
517         dev_emerg(wd->dev, "**** DPM device timeout ****\n");
518         show_stack(wd->tsk, NULL);
519         panic("%s %s: unrecoverable failure\n",
520                 dev_driver_string(wd->dev), dev_name(wd->dev));
521 }
522
523 /**
524  * dpm_watchdog_set - Enable pm watchdog for given device.
525  * @wd: Watchdog. Must be allocated on the stack.
526  * @dev: Device to handle.
527  */
528 static void dpm_watchdog_set(struct dpm_watchdog *wd, struct device *dev)
529 {
530         struct timer_list *timer = &wd->timer;
531
532         wd->dev = dev;
533         wd->tsk = current;
534
535         timer_setup_on_stack(timer, dpm_watchdog_handler, 0);
536         /* use same timeout value for both suspend and resume */
537         timer->expires = jiffies + HZ * CONFIG_DPM_WATCHDOG_TIMEOUT;
538         add_timer(timer);
539 }
540
541 /**
542  * dpm_watchdog_clear - Disable suspend/resume watchdog.
543  * @wd: Watchdog to disable.
544  */
545 static void dpm_watchdog_clear(struct dpm_watchdog *wd)
546 {
547         struct timer_list *timer = &wd->timer;
548
549         del_timer_sync(timer);
550         destroy_timer_on_stack(timer);
551 }
552 #else
553 #define DECLARE_DPM_WATCHDOG_ON_STACK(wd)
554 #define dpm_watchdog_set(x, y)
555 #define dpm_watchdog_clear(x)
556 #endif
557
558 /*------------------------- Resume routines -------------------------*/
559
560 /**
561  * suspend_event - Return a "suspend" message for given "resume" one.
562  * @resume_msg: PM message representing a system-wide resume transition.
563  */
564 static pm_message_t suspend_event(pm_message_t resume_msg)
565 {
566         switch (resume_msg.event) {
567         case PM_EVENT_RESUME:
568                 return PMSG_SUSPEND;
569         case PM_EVENT_THAW:
570         case PM_EVENT_RESTORE:
571                 return PMSG_FREEZE;
572         case PM_EVENT_RECOVER:
573                 return PMSG_HIBERNATE;
574         }
575         return PMSG_ON;
576 }
577
578 /**
579  * dev_pm_may_skip_resume - System-wide device resume optimization check.
580  * @dev: Target device.
581  *
582  * Checks whether or not the device may be left in suspend after a system-wide
583  * transition to the working state.
584  */
585 bool dev_pm_may_skip_resume(struct device *dev)
586 {
587         return !dev->power.must_resume && pm_transition.event != PM_EVENT_RESTORE;
588 }
589
590 static pm_callback_t dpm_subsys_resume_noirq_cb(struct device *dev,
591                                                 pm_message_t state,
592                                                 const char **info_p)
593 {
594         pm_callback_t callback;
595         const char *info;
596
597         if (dev->pm_domain) {
598                 info = "noirq power domain ";
599                 callback = pm_noirq_op(&dev->pm_domain->ops, state);
600         } else if (dev->type && dev->type->pm) {
601                 info = "noirq type ";
602                 callback = pm_noirq_op(dev->type->pm, state);
603         } else if (dev->class && dev->class->pm) {
604                 info = "noirq class ";
605                 callback = pm_noirq_op(dev->class->pm, state);
606         } else if (dev->bus && dev->bus->pm) {
607                 info = "noirq bus ";
608                 callback = pm_noirq_op(dev->bus->pm, state);
609         } else {
610                 return NULL;
611         }
612
613         if (info_p)
614                 *info_p = info;
615
616         return callback;
617 }
618
619 static pm_callback_t dpm_subsys_suspend_noirq_cb(struct device *dev,
620                                                  pm_message_t state,
621                                                  const char **info_p);
622
623 static pm_callback_t dpm_subsys_suspend_late_cb(struct device *dev,
624                                                 pm_message_t state,
625                                                 const char **info_p);
626
627 /**
628  * device_resume_noirq - Execute a "noirq resume" callback for given device.
629  * @dev: Device to handle.
630  * @state: PM transition of the system being carried out.
631  * @async: If true, the device is being resumed asynchronously.
632  *
633  * The driver of @dev will not receive interrupts while this function is being
634  * executed.
635  */
636 static int device_resume_noirq(struct device *dev, pm_message_t state, bool async)
637 {
638         pm_callback_t callback;
639         const char *info;
640         bool skip_resume;
641         int error = 0;
642
643         TRACE_DEVICE(dev);
644         TRACE_RESUME(0);
645
646         if (dev->power.syscore || dev->power.direct_complete)
647                 goto Out;
648
649         if (!dev->power.is_noirq_suspended)
650                 goto Out;
651
652         if (!dpm_wait_for_superior(dev, async))
653                 goto Out;
654
655         skip_resume = dev_pm_may_skip_resume(dev);
656
657         callback = dpm_subsys_resume_noirq_cb(dev, state, &info);
658         if (callback)
659                 goto Run;
660
661         if (skip_resume)
662                 goto Skip;
663
664         if (dev_pm_smart_suspend_and_suspended(dev)) {
665                 pm_message_t suspend_msg = suspend_event(state);
666
667                 /*
668                  * If "freeze" callbacks have been skipped during a transition
669                  * related to hibernation, the subsequent "thaw" callbacks must
670                  * be skipped too or bad things may happen.  Otherwise, resume
671                  * callbacks are going to be run for the device, so its runtime
672                  * PM status must be changed to reflect the new state after the
673                  * transition under way.
674                  */
675                 if (!dpm_subsys_suspend_late_cb(dev, suspend_msg, NULL) &&
676                     !dpm_subsys_suspend_noirq_cb(dev, suspend_msg, NULL)) {
677                         if (state.event == PM_EVENT_THAW) {
678                                 skip_resume = true;
679                                 goto Skip;
680                         } else {
681                                 pm_runtime_set_active(dev);
682                         }
683                 }
684         }
685
686         if (dev->driver && dev->driver->pm) {
687                 info = "noirq driver ";
688                 callback = pm_noirq_op(dev->driver->pm, state);
689         }
690
691 Run:
692         error = dpm_run_callback(callback, dev, state, info);
693
694 Skip:
695         dev->power.is_noirq_suspended = false;
696
697         if (skip_resume) {
698                 /* Make the next phases of resume skip the device. */
699                 dev->power.is_late_suspended = false;
700                 dev->power.is_suspended = false;
701                 /*
702                  * The device is going to be left in suspend, but it might not
703                  * have been in runtime suspend before the system suspended, so
704                  * its runtime PM status needs to be updated to avoid confusing
705                  * the runtime PM framework when runtime PM is enabled for the
706                  * device again.
707                  */
708                 pm_runtime_set_suspended(dev);
709         }
710
711 Out:
712         complete_all(&dev->power.completion);
713         TRACE_RESUME(error);
714         return error;
715 }
716
717 static bool is_async(struct device *dev)
718 {
719         return dev->power.async_suspend && pm_async_enabled
720                 && !pm_trace_is_enabled();
721 }
722
723 static bool dpm_async_fn(struct device *dev, async_func_t func)
724 {
725         reinit_completion(&dev->power.completion);
726
727         if (is_async(dev)) {
728                 get_device(dev);
729                 async_schedule(func, dev);
730                 return true;
731         }
732
733         return false;
734 }
735
736 static void async_resume_noirq(void *data, async_cookie_t cookie)
737 {
738         struct device *dev = (struct device *)data;
739         int error;
740
741         error = device_resume_noirq(dev, pm_transition, true);
742         if (error)
743                 pm_dev_err(dev, pm_transition, " async", error);
744
745         put_device(dev);
746 }
747
748 static void dpm_noirq_resume_devices(pm_message_t state)
749 {
750         struct device *dev;
751         ktime_t starttime = ktime_get();
752
753         trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, true);
754         mutex_lock(&dpm_list_mtx);
755         pm_transition = state;
756
757         /*
758          * Advanced the async threads upfront,
759          * in case the starting of async threads is
760          * delayed by non-async resuming devices.
761          */
762         list_for_each_entry(dev, &dpm_noirq_list, power.entry)
763                 dpm_async_fn(dev, async_resume_noirq);
764
765         while (!list_empty(&dpm_noirq_list)) {
766                 dev = to_device(dpm_noirq_list.next);
767                 get_device(dev);
768                 list_move_tail(&dev->power.entry, &dpm_late_early_list);
769                 mutex_unlock(&dpm_list_mtx);
770
771                 if (!is_async(dev)) {
772                         int error;
773
774                         error = device_resume_noirq(dev, state, false);
775                         if (error) {
776                                 suspend_stats.failed_resume_noirq++;
777                                 dpm_save_failed_step(SUSPEND_RESUME_NOIRQ);
778                                 dpm_save_failed_dev(dev_name(dev));
779                                 pm_dev_err(dev, state, " noirq", error);
780                         }
781                 }
782
783                 mutex_lock(&dpm_list_mtx);
784                 put_device(dev);
785         }
786         mutex_unlock(&dpm_list_mtx);
787         async_synchronize_full();
788         dpm_show_time(starttime, state, 0, "noirq");
789         trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, false);
790 }
791
792 /**
793  * dpm_resume_noirq - Execute "noirq resume" callbacks for all devices.
794  * @state: PM transition of the system being carried out.
795  *
796  * Invoke the "noirq" resume callbacks for all devices in dpm_noirq_list and
797  * allow device drivers' interrupt handlers to be called.
798  */
799 void dpm_resume_noirq(pm_message_t state)
800 {
801         dpm_noirq_resume_devices(state);
802
803         resume_device_irqs();
804         device_wakeup_disarm_wake_irqs();
805
806         cpuidle_resume();
807 }
808
809 static pm_callback_t dpm_subsys_resume_early_cb(struct device *dev,
810                                                 pm_message_t state,
811                                                 const char **info_p)
812 {
813         pm_callback_t callback;
814         const char *info;
815
816         if (dev->pm_domain) {
817                 info = "early power domain ";
818                 callback = pm_late_early_op(&dev->pm_domain->ops, state);
819         } else if (dev->type && dev->type->pm) {
820                 info = "early type ";
821                 callback = pm_late_early_op(dev->type->pm, state);
822         } else if (dev->class && dev->class->pm) {
823                 info = "early class ";
824                 callback = pm_late_early_op(dev->class->pm, state);
825         } else if (dev->bus && dev->bus->pm) {
826                 info = "early bus ";
827                 callback = pm_late_early_op(dev->bus->pm, state);
828         } else {
829                 return NULL;
830         }
831
832         if (info_p)
833                 *info_p = info;
834
835         return callback;
836 }
837
838 /**
839  * device_resume_early - Execute an "early resume" callback for given device.
840  * @dev: Device to handle.
841  * @state: PM transition of the system being carried out.
842  * @async: If true, the device is being resumed asynchronously.
843  *
844  * Runtime PM is disabled for @dev while this function is being executed.
845  */
846 static int device_resume_early(struct device *dev, pm_message_t state, bool async)
847 {
848         pm_callback_t callback;
849         const char *info;
850         int error = 0;
851
852         TRACE_DEVICE(dev);
853         TRACE_RESUME(0);
854
855         if (dev->power.syscore || dev->power.direct_complete)
856                 goto Out;
857
858         if (!dev->power.is_late_suspended)
859                 goto Out;
860
861         if (!dpm_wait_for_superior(dev, async))
862                 goto Out;
863
864         callback = dpm_subsys_resume_early_cb(dev, state, &info);
865
866         if (!callback && dev->driver && dev->driver->pm) {
867                 info = "early driver ";
868                 callback = pm_late_early_op(dev->driver->pm, state);
869         }
870
871         error = dpm_run_callback(callback, dev, state, info);
872         dev->power.is_late_suspended = false;
873
874  Out:
875         TRACE_RESUME(error);
876
877         pm_runtime_enable(dev);
878         complete_all(&dev->power.completion);
879         return error;
880 }
881
882 static void async_resume_early(void *data, async_cookie_t cookie)
883 {
884         struct device *dev = (struct device *)data;
885         int error;
886
887         error = device_resume_early(dev, pm_transition, true);
888         if (error)
889                 pm_dev_err(dev, pm_transition, " async", error);
890
891         put_device(dev);
892 }
893
894 /**
895  * dpm_resume_early - Execute "early resume" callbacks for all devices.
896  * @state: PM transition of the system being carried out.
897  */
898 void dpm_resume_early(pm_message_t state)
899 {
900         struct device *dev;
901         ktime_t starttime = ktime_get();
902
903         trace_suspend_resume(TPS("dpm_resume_early"), state.event, true);
904         mutex_lock(&dpm_list_mtx);
905         pm_transition = state;
906
907         /*
908          * Advanced the async threads upfront,
909          * in case the starting of async threads is
910          * delayed by non-async resuming devices.
911          */
912         list_for_each_entry(dev, &dpm_late_early_list, power.entry)
913                 dpm_async_fn(dev, async_resume_early);
914
915         while (!list_empty(&dpm_late_early_list)) {
916                 dev = to_device(dpm_late_early_list.next);
917                 get_device(dev);
918                 list_move_tail(&dev->power.entry, &dpm_suspended_list);
919                 mutex_unlock(&dpm_list_mtx);
920
921                 if (!is_async(dev)) {
922                         int error;
923
924                         error = device_resume_early(dev, state, false);
925                         if (error) {
926                                 suspend_stats.failed_resume_early++;
927                                 dpm_save_failed_step(SUSPEND_RESUME_EARLY);
928                                 dpm_save_failed_dev(dev_name(dev));
929                                 pm_dev_err(dev, state, " early", error);
930                         }
931                 }
932                 mutex_lock(&dpm_list_mtx);
933                 put_device(dev);
934         }
935         mutex_unlock(&dpm_list_mtx);
936         async_synchronize_full();
937         dpm_show_time(starttime, state, 0, "early");
938         trace_suspend_resume(TPS("dpm_resume_early"), state.event, false);
939 }
940
941 /**
942  * dpm_resume_start - Execute "noirq" and "early" device callbacks.
943  * @state: PM transition of the system being carried out.
944  */
945 void dpm_resume_start(pm_message_t state)
946 {
947         dpm_resume_noirq(state);
948         dpm_resume_early(state);
949 }
950 EXPORT_SYMBOL_GPL(dpm_resume_start);
951
952 /**
953  * device_resume - Execute "resume" callbacks for given device.
954  * @dev: Device to handle.
955  * @state: PM transition of the system being carried out.
956  * @async: If true, the device is being resumed asynchronously.
957  */
958 static int device_resume(struct device *dev, pm_message_t state, bool async)
959 {
960         pm_callback_t callback = NULL;
961         const char *info = NULL;
962         int error = 0;
963         DECLARE_DPM_WATCHDOG_ON_STACK(wd);
964
965         TRACE_DEVICE(dev);
966         TRACE_RESUME(0);
967
968         if (dev->power.syscore)
969                 goto Complete;
970
971         if (dev->power.direct_complete) {
972                 /* Match the pm_runtime_disable() in __device_suspend(). */
973                 pm_runtime_enable(dev);
974                 goto Complete;
975         }
976
977         if (!dpm_wait_for_superior(dev, async))
978                 goto Complete;
979
980         dpm_watchdog_set(&wd, dev);
981         device_lock(dev);
982
983         /*
984          * This is a fib.  But we'll allow new children to be added below
985          * a resumed device, even if the device hasn't been completed yet.
986          */
987         dev->power.is_prepared = false;
988
989         if (!dev->power.is_suspended)
990                 goto Unlock;
991
992         if (dev->pm_domain) {
993                 info = "power domain ";
994                 callback = pm_op(&dev->pm_domain->ops, state);
995                 goto Driver;
996         }
997
998         if (dev->type && dev->type->pm) {
999                 info = "type ";
1000                 callback = pm_op(dev->type->pm, state);
1001                 goto Driver;
1002         }
1003
1004         if (dev->class && dev->class->pm) {
1005                 info = "class ";
1006                 callback = pm_op(dev->class->pm, state);
1007                 goto Driver;
1008         }
1009
1010         if (dev->bus) {
1011                 if (dev->bus->pm) {
1012                         info = "bus ";
1013                         callback = pm_op(dev->bus->pm, state);
1014                 } else if (dev->bus->resume) {
1015                         info = "legacy bus ";
1016                         callback = dev->bus->resume;
1017                         goto End;
1018                 }
1019         }
1020
1021  Driver:
1022         if (!callback && dev->driver && dev->driver->pm) {
1023                 info = "driver ";
1024                 callback = pm_op(dev->driver->pm, state);
1025         }
1026
1027  End:
1028         error = dpm_run_callback(callback, dev, state, info);
1029         dev->power.is_suspended = false;
1030
1031  Unlock:
1032         device_unlock(dev);
1033         dpm_watchdog_clear(&wd);
1034
1035  Complete:
1036         complete_all(&dev->power.completion);
1037
1038         TRACE_RESUME(error);
1039
1040         return error;
1041 }
1042
1043 static void async_resume(void *data, async_cookie_t cookie)
1044 {
1045         struct device *dev = (struct device *)data;
1046         int error;
1047
1048         error = device_resume(dev, pm_transition, true);
1049         if (error)
1050                 pm_dev_err(dev, pm_transition, " async", error);
1051         put_device(dev);
1052 }
1053
1054 /**
1055  * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
1056  * @state: PM transition of the system being carried out.
1057  *
1058  * Execute the appropriate "resume" callback for all devices whose status
1059  * indicates that they are suspended.
1060  */
1061 void dpm_resume(pm_message_t state)
1062 {
1063         struct device *dev;
1064         ktime_t starttime = ktime_get();
1065
1066         trace_suspend_resume(TPS("dpm_resume"), state.event, true);
1067         might_sleep();
1068
1069         mutex_lock(&dpm_list_mtx);
1070         pm_transition = state;
1071         async_error = 0;
1072
1073         list_for_each_entry(dev, &dpm_suspended_list, power.entry)
1074                 dpm_async_fn(dev, async_resume);
1075
1076         while (!list_empty(&dpm_suspended_list)) {
1077                 dev = to_device(dpm_suspended_list.next);
1078                 get_device(dev);
1079                 if (!is_async(dev)) {
1080                         int error;
1081
1082                         mutex_unlock(&dpm_list_mtx);
1083
1084                         error = device_resume(dev, state, false);
1085                         if (error) {
1086                                 suspend_stats.failed_resume++;
1087                                 dpm_save_failed_step(SUSPEND_RESUME);
1088                                 dpm_save_failed_dev(dev_name(dev));
1089                                 pm_dev_err(dev, state, "", error);
1090                         }
1091
1092                         mutex_lock(&dpm_list_mtx);
1093                 }
1094                 if (!list_empty(&dev->power.entry))
1095                         list_move_tail(&dev->power.entry, &dpm_prepared_list);
1096                 put_device(dev);
1097         }
1098         mutex_unlock(&dpm_list_mtx);
1099         async_synchronize_full();
1100         dpm_show_time(starttime, state, 0, NULL);
1101
1102         cpufreq_resume();
1103         devfreq_resume();
1104         trace_suspend_resume(TPS("dpm_resume"), state.event, false);
1105 }
1106
1107 /**
1108  * device_complete - Complete a PM transition for given device.
1109  * @dev: Device to handle.
1110  * @state: PM transition of the system being carried out.
1111  */
1112 static void device_complete(struct device *dev, pm_message_t state)
1113 {
1114         void (*callback)(struct device *) = NULL;
1115         const char *info = NULL;
1116
1117         if (dev->power.syscore)
1118                 return;
1119
1120         device_lock(dev);
1121
1122         if (dev->pm_domain) {
1123                 info = "completing power domain ";
1124                 callback = dev->pm_domain->ops.complete;
1125         } else if (dev->type && dev->type->pm) {
1126                 info = "completing type ";
1127                 callback = dev->type->pm->complete;
1128         } else if (dev->class && dev->class->pm) {
1129                 info = "completing class ";
1130                 callback = dev->class->pm->complete;
1131         } else if (dev->bus && dev->bus->pm) {
1132                 info = "completing bus ";
1133                 callback = dev->bus->pm->complete;
1134         }
1135
1136         if (!callback && dev->driver && dev->driver->pm) {
1137                 info = "completing driver ";
1138                 callback = dev->driver->pm->complete;
1139         }
1140
1141         if (callback) {
1142                 pm_dev_dbg(dev, state, info);
1143                 callback(dev);
1144         }
1145
1146         device_unlock(dev);
1147
1148         pm_runtime_put(dev);
1149 }
1150
1151 /**
1152  * dpm_complete - Complete a PM transition for all non-sysdev devices.
1153  * @state: PM transition of the system being carried out.
1154  *
1155  * Execute the ->complete() callbacks for all devices whose PM status is not
1156  * DPM_ON (this allows new devices to be registered).
1157  */
1158 void dpm_complete(pm_message_t state)
1159 {
1160         struct list_head list;
1161
1162         trace_suspend_resume(TPS("dpm_complete"), state.event, true);
1163         might_sleep();
1164
1165         INIT_LIST_HEAD(&list);
1166         mutex_lock(&dpm_list_mtx);
1167         while (!list_empty(&dpm_prepared_list)) {
1168                 struct device *dev = to_device(dpm_prepared_list.prev);
1169
1170                 get_device(dev);
1171                 dev->power.is_prepared = false;
1172                 list_move(&dev->power.entry, &list);
1173                 mutex_unlock(&dpm_list_mtx);
1174
1175                 trace_device_pm_callback_start(dev, "", state.event);
1176                 device_complete(dev, state);
1177                 trace_device_pm_callback_end(dev, 0);
1178
1179                 mutex_lock(&dpm_list_mtx);
1180                 put_device(dev);
1181         }
1182         list_splice(&list, &dpm_list);
1183         mutex_unlock(&dpm_list_mtx);
1184
1185         /* Allow device probing and trigger re-probing of deferred devices */
1186         device_unblock_probing();
1187         trace_suspend_resume(TPS("dpm_complete"), state.event, false);
1188 }
1189
1190 /**
1191  * dpm_resume_end - Execute "resume" callbacks and complete system transition.
1192  * @state: PM transition of the system being carried out.
1193  *
1194  * Execute "resume" callbacks for all devices and complete the PM transition of
1195  * the system.
1196  */
1197 void dpm_resume_end(pm_message_t state)
1198 {
1199         dpm_resume(state);
1200         dpm_complete(state);
1201 }
1202 EXPORT_SYMBOL_GPL(dpm_resume_end);
1203
1204
1205 /*------------------------- Suspend routines -------------------------*/
1206
1207 /**
1208  * resume_event - Return a "resume" message for given "suspend" sleep state.
1209  * @sleep_state: PM message representing a sleep state.
1210  *
1211  * Return a PM message representing the resume event corresponding to given
1212  * sleep state.
1213  */
1214 static pm_message_t resume_event(pm_message_t sleep_state)
1215 {
1216         switch (sleep_state.event) {
1217         case PM_EVENT_SUSPEND:
1218                 return PMSG_RESUME;
1219         case PM_EVENT_FREEZE:
1220         case PM_EVENT_QUIESCE:
1221                 return PMSG_RECOVER;
1222         case PM_EVENT_HIBERNATE:
1223                 return PMSG_RESTORE;
1224         }
1225         return PMSG_ON;
1226 }
1227
1228 static void dpm_superior_set_must_resume(struct device *dev)
1229 {
1230         struct device_link *link;
1231         int idx;
1232
1233         if (dev->parent)
1234                 dev->parent->power.must_resume = true;
1235
1236         idx = device_links_read_lock();
1237
1238         list_for_each_entry_rcu(link, &dev->links.suppliers, c_node)
1239                 link->supplier->power.must_resume = true;
1240
1241         device_links_read_unlock(idx);
1242 }
1243
1244 static pm_callback_t dpm_subsys_suspend_noirq_cb(struct device *dev,
1245                                                  pm_message_t state,
1246                                                  const char **info_p)
1247 {
1248         pm_callback_t callback;
1249         const char *info;
1250
1251         if (dev->pm_domain) {
1252                 info = "noirq power domain ";
1253                 callback = pm_noirq_op(&dev->pm_domain->ops, state);
1254         } else if (dev->type && dev->type->pm) {
1255                 info = "noirq type ";
1256                 callback = pm_noirq_op(dev->type->pm, state);
1257         } else if (dev->class && dev->class->pm) {
1258                 info = "noirq class ";
1259                 callback = pm_noirq_op(dev->class->pm, state);
1260         } else if (dev->bus && dev->bus->pm) {
1261                 info = "noirq bus ";
1262                 callback = pm_noirq_op(dev->bus->pm, state);
1263         } else {
1264                 return NULL;
1265         }
1266
1267         if (info_p)
1268                 *info_p = info;
1269
1270         return callback;
1271 }
1272
1273 static bool device_must_resume(struct device *dev, pm_message_t state,
1274                                bool no_subsys_suspend_noirq)
1275 {
1276         pm_message_t resume_msg = resume_event(state);
1277
1278         /*
1279          * If all of the device driver's "noirq", "late" and "early" callbacks
1280          * are invoked directly by the core, the decision to allow the device to
1281          * stay in suspend can be based on its current runtime PM status and its
1282          * wakeup settings.
1283          */
1284         if (no_subsys_suspend_noirq &&
1285             !dpm_subsys_suspend_late_cb(dev, state, NULL) &&
1286             !dpm_subsys_resume_early_cb(dev, resume_msg, NULL) &&
1287             !dpm_subsys_resume_noirq_cb(dev, resume_msg, NULL))
1288                 return !pm_runtime_status_suspended(dev) &&
1289                         (resume_msg.event != PM_EVENT_RESUME ||
1290                          (device_can_wakeup(dev) && !device_may_wakeup(dev)));
1291
1292         /*
1293          * The only safe strategy here is to require that if the device may not
1294          * be left in suspend, resume callbacks must be invoked for it.
1295          */
1296         return !dev->power.may_skip_resume;
1297 }
1298
1299 /**
1300  * __device_suspend_noirq - Execute a "noirq suspend" callback for given device.
1301  * @dev: Device to handle.
1302  * @state: PM transition of the system being carried out.
1303  * @async: If true, the device is being suspended asynchronously.
1304  *
1305  * The driver of @dev will not receive interrupts while this function is being
1306  * executed.
1307  */
1308 static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool async)
1309 {
1310         pm_callback_t callback;
1311         const char *info;
1312         bool no_subsys_cb = false;
1313         int error = 0;
1314
1315         TRACE_DEVICE(dev);
1316         TRACE_SUSPEND(0);
1317
1318         dpm_wait_for_subordinate(dev, async);
1319
1320         if (async_error)
1321                 goto Complete;
1322
1323         if (dev->power.syscore || dev->power.direct_complete)
1324                 goto Complete;
1325
1326         callback = dpm_subsys_suspend_noirq_cb(dev, state, &info);
1327         if (callback)
1328                 goto Run;
1329
1330         no_subsys_cb = !dpm_subsys_suspend_late_cb(dev, state, NULL);
1331
1332         if (dev_pm_smart_suspend_and_suspended(dev) && no_subsys_cb)
1333                 goto Skip;
1334
1335         if (dev->driver && dev->driver->pm) {
1336                 info = "noirq driver ";
1337                 callback = pm_noirq_op(dev->driver->pm, state);
1338         }
1339
1340 Run:
1341         error = dpm_run_callback(callback, dev, state, info);
1342         if (error) {
1343                 async_error = error;
1344                 goto Complete;
1345         }
1346
1347 Skip:
1348         dev->power.is_noirq_suspended = true;
1349
1350         if (dev_pm_test_driver_flags(dev, DPM_FLAG_LEAVE_SUSPENDED)) {
1351                 dev->power.must_resume = dev->power.must_resume ||
1352                                 atomic_read(&dev->power.usage_count) > 1 ||
1353                                 device_must_resume(dev, state, no_subsys_cb);
1354         } else {
1355                 dev->power.must_resume = true;
1356         }
1357
1358         if (dev->power.must_resume)
1359                 dpm_superior_set_must_resume(dev);
1360
1361 Complete:
1362         complete_all(&dev->power.completion);
1363         TRACE_SUSPEND(error);
1364         return error;
1365 }
1366
1367 static void async_suspend_noirq(void *data, async_cookie_t cookie)
1368 {
1369         struct device *dev = (struct device *)data;
1370         int error;
1371
1372         error = __device_suspend_noirq(dev, pm_transition, true);
1373         if (error) {
1374                 dpm_save_failed_dev(dev_name(dev));
1375                 pm_dev_err(dev, pm_transition, " async", error);
1376         }
1377
1378         put_device(dev);
1379 }
1380
1381 static int device_suspend_noirq(struct device *dev)
1382 {
1383         if (dpm_async_fn(dev, async_suspend_noirq))
1384                 return 0;
1385
1386         return __device_suspend_noirq(dev, pm_transition, false);
1387 }
1388
1389 static int dpm_noirq_suspend_devices(pm_message_t state)
1390 {
1391         ktime_t starttime = ktime_get();
1392         int error = 0;
1393
1394         trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, true);
1395         mutex_lock(&dpm_list_mtx);
1396         pm_transition = state;
1397         async_error = 0;
1398
1399         while (!list_empty(&dpm_late_early_list)) {
1400                 struct device *dev = to_device(dpm_late_early_list.prev);
1401
1402                 get_device(dev);
1403                 mutex_unlock(&dpm_list_mtx);
1404
1405                 error = device_suspend_noirq(dev);
1406
1407                 mutex_lock(&dpm_list_mtx);
1408                 if (error) {
1409                         pm_dev_err(dev, state, " noirq", error);
1410                         dpm_save_failed_dev(dev_name(dev));
1411                         put_device(dev);
1412                         break;
1413                 }
1414                 if (!list_empty(&dev->power.entry))
1415                         list_move(&dev->power.entry, &dpm_noirq_list);
1416                 put_device(dev);
1417
1418                 if (async_error)
1419                         break;
1420         }
1421         mutex_unlock(&dpm_list_mtx);
1422         async_synchronize_full();
1423         if (!error)
1424                 error = async_error;
1425
1426         if (error) {
1427                 suspend_stats.failed_suspend_noirq++;
1428                 dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ);
1429         }
1430         dpm_show_time(starttime, state, error, "noirq");
1431         trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, false);
1432         return error;
1433 }
1434
1435 /**
1436  * dpm_suspend_noirq - Execute "noirq suspend" callbacks for all devices.
1437  * @state: PM transition of the system being carried out.
1438  *
1439  * Prevent device drivers' interrupt handlers from being called and invoke
1440  * "noirq" suspend callbacks for all non-sysdev devices.
1441  */
1442 int dpm_suspend_noirq(pm_message_t state)
1443 {
1444         int ret;
1445
1446         cpuidle_pause();
1447
1448         device_wakeup_arm_wake_irqs();
1449         suspend_device_irqs();
1450
1451         ret = dpm_noirq_suspend_devices(state);
1452         if (ret)
1453                 dpm_resume_noirq(resume_event(state));
1454
1455         return ret;
1456 }
1457
1458 static void dpm_propagate_wakeup_to_parent(struct device *dev)
1459 {
1460         struct device *parent = dev->parent;
1461
1462         if (!parent)
1463                 return;
1464
1465         spin_lock_irq(&parent->power.lock);
1466
1467         if (dev->power.wakeup_path && !parent->power.ignore_children)
1468                 parent->power.wakeup_path = true;
1469
1470         spin_unlock_irq(&parent->power.lock);
1471 }
1472
1473 static pm_callback_t dpm_subsys_suspend_late_cb(struct device *dev,
1474                                                 pm_message_t state,
1475                                                 const char **info_p)
1476 {
1477         pm_callback_t callback;
1478         const char *info;
1479
1480         if (dev->pm_domain) {
1481                 info = "late power domain ";
1482                 callback = pm_late_early_op(&dev->pm_domain->ops, state);
1483         } else if (dev->type && dev->type->pm) {
1484                 info = "late type ";
1485                 callback = pm_late_early_op(dev->type->pm, state);
1486         } else if (dev->class && dev->class->pm) {
1487                 info = "late class ";
1488                 callback = pm_late_early_op(dev->class->pm, state);
1489         } else if (dev->bus && dev->bus->pm) {
1490                 info = "late bus ";
1491                 callback = pm_late_early_op(dev->bus->pm, state);
1492         } else {
1493                 return NULL;
1494         }
1495
1496         if (info_p)
1497                 *info_p = info;
1498
1499         return callback;
1500 }
1501
1502 /**
1503  * __device_suspend_late - Execute a "late suspend" callback for given device.
1504  * @dev: Device to handle.
1505  * @state: PM transition of the system being carried out.
1506  * @async: If true, the device is being suspended asynchronously.
1507  *
1508  * Runtime PM is disabled for @dev while this function is being executed.
1509  */
1510 static int __device_suspend_late(struct device *dev, pm_message_t state, bool async)
1511 {
1512         pm_callback_t callback;
1513         const char *info;
1514         int error = 0;
1515
1516         TRACE_DEVICE(dev);
1517         TRACE_SUSPEND(0);
1518
1519         __pm_runtime_disable(dev, false);
1520
1521         dpm_wait_for_subordinate(dev, async);
1522
1523         if (async_error)
1524                 goto Complete;
1525
1526         if (pm_wakeup_pending()) {
1527                 async_error = -EBUSY;
1528                 goto Complete;
1529         }
1530
1531         if (dev->power.syscore || dev->power.direct_complete)
1532                 goto Complete;
1533
1534         callback = dpm_subsys_suspend_late_cb(dev, state, &info);
1535         if (callback)
1536                 goto Run;
1537
1538         if (dev_pm_smart_suspend_and_suspended(dev) &&
1539             !dpm_subsys_suspend_noirq_cb(dev, state, NULL))
1540                 goto Skip;
1541
1542         if (dev->driver && dev->driver->pm) {
1543                 info = "late driver ";
1544                 callback = pm_late_early_op(dev->driver->pm, state);
1545         }
1546
1547 Run:
1548         error = dpm_run_callback(callback, dev, state, info);
1549         if (error) {
1550                 async_error = error;
1551                 goto Complete;
1552         }
1553         dpm_propagate_wakeup_to_parent(dev);
1554
1555 Skip:
1556         dev->power.is_late_suspended = true;
1557
1558 Complete:
1559         TRACE_SUSPEND(error);
1560         complete_all(&dev->power.completion);
1561         return error;
1562 }
1563
1564 static void async_suspend_late(void *data, async_cookie_t cookie)
1565 {
1566         struct device *dev = (struct device *)data;
1567         int error;
1568
1569         error = __device_suspend_late(dev, pm_transition, true);
1570         if (error) {
1571                 dpm_save_failed_dev(dev_name(dev));
1572                 pm_dev_err(dev, pm_transition, " async", error);
1573         }
1574         put_device(dev);
1575 }
1576
1577 static int device_suspend_late(struct device *dev)
1578 {
1579         if (dpm_async_fn(dev, async_suspend_late))
1580                 return 0;
1581
1582         return __device_suspend_late(dev, pm_transition, false);
1583 }
1584
1585 /**
1586  * dpm_suspend_late - Execute "late suspend" callbacks for all devices.
1587  * @state: PM transition of the system being carried out.
1588  */
1589 int dpm_suspend_late(pm_message_t state)
1590 {
1591         ktime_t starttime = ktime_get();
1592         int error = 0;
1593
1594         trace_suspend_resume(TPS("dpm_suspend_late"), state.event, true);
1595         mutex_lock(&dpm_list_mtx);
1596         pm_transition = state;
1597         async_error = 0;
1598
1599         while (!list_empty(&dpm_suspended_list)) {
1600                 struct device *dev = to_device(dpm_suspended_list.prev);
1601
1602                 get_device(dev);
1603                 mutex_unlock(&dpm_list_mtx);
1604
1605                 error = device_suspend_late(dev);
1606
1607                 mutex_lock(&dpm_list_mtx);
1608                 if (!list_empty(&dev->power.entry))
1609                         list_move(&dev->power.entry, &dpm_late_early_list);
1610
1611                 if (error) {
1612                         pm_dev_err(dev, state, " late", error);
1613                         dpm_save_failed_dev(dev_name(dev));
1614                         put_device(dev);
1615                         break;
1616                 }
1617                 put_device(dev);
1618
1619                 if (async_error)
1620                         break;
1621         }
1622         mutex_unlock(&dpm_list_mtx);
1623         async_synchronize_full();
1624         if (!error)
1625                 error = async_error;
1626         if (error) {
1627                 suspend_stats.failed_suspend_late++;
1628                 dpm_save_failed_step(SUSPEND_SUSPEND_LATE);
1629                 dpm_resume_early(resume_event(state));
1630         }
1631         dpm_show_time(starttime, state, error, "late");
1632         trace_suspend_resume(TPS("dpm_suspend_late"), state.event, false);
1633         return error;
1634 }
1635
1636 /**
1637  * dpm_suspend_end - Execute "late" and "noirq" device suspend callbacks.
1638  * @state: PM transition of the system being carried out.
1639  */
1640 int dpm_suspend_end(pm_message_t state)
1641 {
1642         ktime_t starttime = ktime_get();
1643         int error;
1644
1645         error = dpm_suspend_late(state);
1646         if (error)
1647                 goto out;
1648
1649         error = dpm_suspend_noirq(state);
1650         if (error)
1651                 dpm_resume_early(resume_event(state));
1652
1653 out:
1654         dpm_show_time(starttime, state, error, "end");
1655         return error;
1656 }
1657 EXPORT_SYMBOL_GPL(dpm_suspend_end);
1658
1659 /**
1660  * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
1661  * @dev: Device to suspend.
1662  * @state: PM transition of the system being carried out.
1663  * @cb: Suspend callback to execute.
1664  * @info: string description of caller.
1665  */
1666 static int legacy_suspend(struct device *dev, pm_message_t state,
1667                           int (*cb)(struct device *dev, pm_message_t state),
1668                           const char *info)
1669 {
1670         int error;
1671         ktime_t calltime;
1672
1673         calltime = initcall_debug_start(dev, cb);
1674
1675         trace_device_pm_callback_start(dev, info, state.event);
1676         error = cb(dev, state);
1677         trace_device_pm_callback_end(dev, error);
1678         suspend_report_result(cb, error);
1679
1680         initcall_debug_report(dev, calltime, cb, error);
1681
1682         return error;
1683 }
1684
1685 static void dpm_clear_superiors_direct_complete(struct device *dev)
1686 {
1687         struct device_link *link;
1688         int idx;
1689
1690         if (dev->parent) {
1691                 spin_lock_irq(&dev->parent->power.lock);
1692                 dev->parent->power.direct_complete = false;
1693                 spin_unlock_irq(&dev->parent->power.lock);
1694         }
1695
1696         idx = device_links_read_lock();
1697
1698         list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) {
1699                 spin_lock_irq(&link->supplier->power.lock);
1700                 link->supplier->power.direct_complete = false;
1701                 spin_unlock_irq(&link->supplier->power.lock);
1702         }
1703
1704         device_links_read_unlock(idx);
1705 }
1706
1707 /**
1708  * __device_suspend - Execute "suspend" callbacks for given device.
1709  * @dev: Device to handle.
1710  * @state: PM transition of the system being carried out.
1711  * @async: If true, the device is being suspended asynchronously.
1712  */
1713 static int __device_suspend(struct device *dev, pm_message_t state, bool async)
1714 {
1715         pm_callback_t callback = NULL;
1716         const char *info = NULL;
1717         int error = 0;
1718         DECLARE_DPM_WATCHDOG_ON_STACK(wd);
1719
1720         TRACE_DEVICE(dev);
1721         TRACE_SUSPEND(0);
1722
1723         dpm_wait_for_subordinate(dev, async);
1724
1725         if (async_error) {
1726                 dev->power.direct_complete = false;
1727                 goto Complete;
1728         }
1729
1730         /*
1731          * If a device configured to wake up the system from sleep states
1732          * has been suspended at run time and there's a resume request pending
1733          * for it, this is equivalent to the device signaling wakeup, so the
1734          * system suspend operation should be aborted.
1735          */
1736         if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
1737                 pm_wakeup_event(dev, 0);
1738
1739         if (pm_wakeup_pending()) {
1740                 dev->power.direct_complete = false;
1741                 async_error = -EBUSY;
1742                 goto Complete;
1743         }
1744
1745         if (dev->power.syscore)
1746                 goto Complete;
1747
1748         /* Avoid direct_complete to let wakeup_path propagate. */
1749         if (device_may_wakeup(dev) || dev->power.wakeup_path)
1750                 dev->power.direct_complete = false;
1751
1752         if (dev->power.direct_complete) {
1753                 if (pm_runtime_status_suspended(dev)) {
1754                         pm_runtime_disable(dev);
1755                         if (pm_runtime_status_suspended(dev)) {
1756                                 pm_dev_dbg(dev, state, "direct-complete ");
1757                                 goto Complete;
1758                         }
1759
1760                         pm_runtime_enable(dev);
1761                 }
1762                 dev->power.direct_complete = false;
1763         }
1764
1765         dev->power.may_skip_resume = false;
1766         dev->power.must_resume = false;
1767
1768         dpm_watchdog_set(&wd, dev);
1769         device_lock(dev);
1770
1771         if (dev->pm_domain) {
1772                 info = "power domain ";
1773                 callback = pm_op(&dev->pm_domain->ops, state);
1774                 goto Run;
1775         }
1776
1777         if (dev->type && dev->type->pm) {
1778                 info = "type ";
1779                 callback = pm_op(dev->type->pm, state);
1780                 goto Run;
1781         }
1782
1783         if (dev->class && dev->class->pm) {
1784                 info = "class ";
1785                 callback = pm_op(dev->class->pm, state);
1786                 goto Run;
1787         }
1788
1789         if (dev->bus) {
1790                 if (dev->bus->pm) {
1791                         info = "bus ";
1792                         callback = pm_op(dev->bus->pm, state);
1793                 } else if (dev->bus->suspend) {
1794                         pm_dev_dbg(dev, state, "legacy bus ");
1795                         error = legacy_suspend(dev, state, dev->bus->suspend,
1796                                                 "legacy bus ");
1797                         goto End;
1798                 }
1799         }
1800
1801  Run:
1802         if (!callback && dev->driver && dev->driver->pm) {
1803                 info = "driver ";
1804                 callback = pm_op(dev->driver->pm, state);
1805         }
1806
1807         error = dpm_run_callback(callback, dev, state, info);
1808
1809  End:
1810         if (!error) {
1811                 dev->power.is_suspended = true;
1812                 if (device_may_wakeup(dev))
1813                         dev->power.wakeup_path = true;
1814
1815                 dpm_propagate_wakeup_to_parent(dev);
1816                 dpm_clear_superiors_direct_complete(dev);
1817         }
1818
1819         device_unlock(dev);
1820         dpm_watchdog_clear(&wd);
1821
1822  Complete:
1823         if (error)
1824                 async_error = error;
1825
1826         complete_all(&dev->power.completion);
1827         TRACE_SUSPEND(error);
1828         return error;
1829 }
1830
1831 static void async_suspend(void *data, async_cookie_t cookie)
1832 {
1833         struct device *dev = (struct device *)data;
1834         int error;
1835
1836         error = __device_suspend(dev, pm_transition, true);
1837         if (error) {
1838                 dpm_save_failed_dev(dev_name(dev));
1839                 pm_dev_err(dev, pm_transition, " async", error);
1840         }
1841
1842         put_device(dev);
1843 }
1844
1845 static int device_suspend(struct device *dev)
1846 {
1847         if (dpm_async_fn(dev, async_suspend))
1848                 return 0;
1849
1850         return __device_suspend(dev, pm_transition, false);
1851 }
1852
1853 /**
1854  * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
1855  * @state: PM transition of the system being carried out.
1856  */
1857 int dpm_suspend(pm_message_t state)
1858 {
1859         ktime_t starttime = ktime_get();
1860         int error = 0;
1861
1862         trace_suspend_resume(TPS("dpm_suspend"), state.event, true);
1863         might_sleep();
1864
1865         devfreq_suspend();
1866         cpufreq_suspend();
1867
1868         mutex_lock(&dpm_list_mtx);
1869         pm_transition = state;
1870         async_error = 0;
1871         while (!list_empty(&dpm_prepared_list)) {
1872                 struct device *dev = to_device(dpm_prepared_list.prev);
1873
1874                 get_device(dev);
1875                 mutex_unlock(&dpm_list_mtx);
1876
1877                 error = device_suspend(dev);
1878
1879                 mutex_lock(&dpm_list_mtx);
1880                 if (error) {
1881                         pm_dev_err(dev, state, "", error);
1882                         dpm_save_failed_dev(dev_name(dev));
1883                         put_device(dev);
1884                         break;
1885                 }
1886                 if (!list_empty(&dev->power.entry))
1887                         list_move(&dev->power.entry, &dpm_suspended_list);
1888                 put_device(dev);
1889                 if (async_error)
1890                         break;
1891         }
1892         mutex_unlock(&dpm_list_mtx);
1893         async_synchronize_full();
1894         if (!error)
1895                 error = async_error;
1896         if (error) {
1897                 suspend_stats.failed_suspend++;
1898                 dpm_save_failed_step(SUSPEND_SUSPEND);
1899         }
1900         dpm_show_time(starttime, state, error, NULL);
1901         trace_suspend_resume(TPS("dpm_suspend"), state.event, false);
1902         return error;
1903 }
1904
1905 /**
1906  * device_prepare - Prepare a device for system power transition.
1907  * @dev: Device to handle.
1908  * @state: PM transition of the system being carried out.
1909  *
1910  * Execute the ->prepare() callback(s) for given device.  No new children of the
1911  * device may be registered after this function has returned.
1912  */
1913 static int device_prepare(struct device *dev, pm_message_t state)
1914 {
1915         int (*callback)(struct device *) = NULL;
1916         int ret = 0;
1917
1918         if (dev->power.syscore)
1919                 return 0;
1920
1921         WARN_ON(!pm_runtime_enabled(dev) &&
1922                 dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND |
1923                                               DPM_FLAG_LEAVE_SUSPENDED));
1924
1925         /*
1926          * If a device's parent goes into runtime suspend at the wrong time,
1927          * it won't be possible to resume the device.  To prevent this we
1928          * block runtime suspend here, during the prepare phase, and allow
1929          * it again during the complete phase.
1930          */
1931         pm_runtime_get_noresume(dev);
1932
1933         device_lock(dev);
1934
1935         dev->power.wakeup_path = false;
1936
1937         if (dev->power.no_pm_callbacks)
1938                 goto unlock;
1939
1940         if (dev->pm_domain)
1941                 callback = dev->pm_domain->ops.prepare;
1942         else if (dev->type && dev->type->pm)
1943                 callback = dev->type->pm->prepare;
1944         else if (dev->class && dev->class->pm)
1945                 callback = dev->class->pm->prepare;
1946         else if (dev->bus && dev->bus->pm)
1947                 callback = dev->bus->pm->prepare;
1948
1949         if (!callback && dev->driver && dev->driver->pm)
1950                 callback = dev->driver->pm->prepare;
1951
1952         if (callback)
1953                 ret = callback(dev);
1954
1955 unlock:
1956         device_unlock(dev);
1957
1958         if (ret < 0) {
1959                 suspend_report_result(callback, ret);
1960                 pm_runtime_put(dev);
1961                 return ret;
1962         }
1963         /*
1964          * A positive return value from ->prepare() means "this device appears
1965          * to be runtime-suspended and its state is fine, so if it really is
1966          * runtime-suspended, you can leave it in that state provided that you
1967          * will do the same thing with all of its descendants".  This only
1968          * applies to suspend transitions, however.
1969          */
1970         spin_lock_irq(&dev->power.lock);
1971         dev->power.direct_complete = state.event == PM_EVENT_SUSPEND &&
1972                 ((pm_runtime_suspended(dev) && ret > 0) ||
1973                  dev->power.no_pm_callbacks) &&
1974                 !dev_pm_test_driver_flags(dev, DPM_FLAG_NEVER_SKIP);
1975         spin_unlock_irq(&dev->power.lock);
1976         return 0;
1977 }
1978
1979 /**
1980  * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1981  * @state: PM transition of the system being carried out.
1982  *
1983  * Execute the ->prepare() callback(s) for all devices.
1984  */
1985 int dpm_prepare(pm_message_t state)
1986 {
1987         int error = 0;
1988
1989         trace_suspend_resume(TPS("dpm_prepare"), state.event, true);
1990         might_sleep();
1991
1992         /*
1993          * Give a chance for the known devices to complete their probes, before
1994          * disable probing of devices. This sync point is important at least
1995          * at boot time + hibernation restore.
1996          */
1997         wait_for_device_probe();
1998         /*
1999          * It is unsafe if probing of devices will happen during suspend or
2000          * hibernation and system behavior will be unpredictable in this case.
2001          * So, let's prohibit device's probing here and defer their probes
2002          * instead. The normal behavior will be restored in dpm_complete().
2003          */
2004         device_block_probing();
2005
2006         mutex_lock(&dpm_list_mtx);
2007         while (!list_empty(&dpm_list)) {
2008                 struct device *dev = to_device(dpm_list.next);
2009
2010                 get_device(dev);
2011                 mutex_unlock(&dpm_list_mtx);
2012
2013                 trace_device_pm_callback_start(dev, "", state.event);
2014                 error = device_prepare(dev, state);
2015                 trace_device_pm_callback_end(dev, error);
2016
2017                 mutex_lock(&dpm_list_mtx);
2018                 if (error) {
2019                         if (error == -EAGAIN) {
2020                                 put_device(dev);
2021                                 error = 0;
2022                                 continue;
2023                         }
2024                         pr_info("Device %s not prepared for power transition: code %d\n",
2025                                 dev_name(dev), error);
2026                         put_device(dev);
2027                         break;
2028                 }
2029                 dev->power.is_prepared = true;
2030                 if (!list_empty(&dev->power.entry))
2031                         list_move_tail(&dev->power.entry, &dpm_prepared_list);
2032                 put_device(dev);
2033         }
2034         mutex_unlock(&dpm_list_mtx);
2035         trace_suspend_resume(TPS("dpm_prepare"), state.event, false);
2036         return error;
2037 }
2038
2039 /**
2040  * dpm_suspend_start - Prepare devices for PM transition and suspend them.
2041  * @state: PM transition of the system being carried out.
2042  *
2043  * Prepare all non-sysdev devices for system PM transition and execute "suspend"
2044  * callbacks for them.
2045  */
2046 int dpm_suspend_start(pm_message_t state)
2047 {
2048         ktime_t starttime = ktime_get();
2049         int error;
2050
2051         error = dpm_prepare(state);
2052         if (error) {
2053                 suspend_stats.failed_prepare++;
2054                 dpm_save_failed_step(SUSPEND_PREPARE);
2055         } else
2056                 error = dpm_suspend(state);
2057         dpm_show_time(starttime, state, error, "start");
2058         return error;
2059 }
2060 EXPORT_SYMBOL_GPL(dpm_suspend_start);
2061
2062 void __suspend_report_result(const char *function, void *fn, int ret)
2063 {
2064         if (ret)
2065                 pr_err("%s(): %pS returns %d\n", function, fn, ret);
2066 }
2067 EXPORT_SYMBOL_GPL(__suspend_report_result);
2068
2069 /**
2070  * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
2071  * @subordinate: Device that needs to wait for @dev.
2072  * @dev: Device to wait for.
2073  */
2074 int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
2075 {
2076         dpm_wait(dev, subordinate->power.async_suspend);
2077         return async_error;
2078 }
2079 EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);
2080
2081 /**
2082  * dpm_for_each_dev - device iterator.
2083  * @data: data for the callback.
2084  * @fn: function to be called for each device.
2085  *
2086  * Iterate over devices in dpm_list, and call @fn for each device,
2087  * passing it @data.
2088  */
2089 void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *))
2090 {
2091         struct device *dev;
2092
2093         if (!fn)
2094                 return;
2095
2096         device_pm_lock();
2097         list_for_each_entry(dev, &dpm_list, power.entry)
2098                 fn(dev, data);
2099         device_pm_unlock();
2100 }
2101 EXPORT_SYMBOL_GPL(dpm_for_each_dev);
2102
2103 static bool pm_ops_is_empty(const struct dev_pm_ops *ops)
2104 {
2105         if (!ops)
2106                 return true;
2107
2108         return !ops->prepare &&
2109                !ops->suspend &&
2110                !ops->suspend_late &&
2111                !ops->suspend_noirq &&
2112                !ops->resume_noirq &&
2113                !ops->resume_early &&
2114                !ops->resume &&
2115                !ops->complete;
2116 }
2117
2118 void device_pm_check_callbacks(struct device *dev)
2119 {
2120         spin_lock_irq(&dev->power.lock);
2121         dev->power.no_pm_callbacks =
2122                 (!dev->bus || (pm_ops_is_empty(dev->bus->pm) &&
2123                  !dev->bus->suspend && !dev->bus->resume)) &&
2124                 (!dev->class || pm_ops_is_empty(dev->class->pm)) &&
2125                 (!dev->type || pm_ops_is_empty(dev->type->pm)) &&
2126                 (!dev->pm_domain || pm_ops_is_empty(&dev->pm_domain->ops)) &&
2127                 (!dev->driver || (pm_ops_is_empty(dev->driver->pm) &&
2128                  !dev->driver->suspend && !dev->driver->resume));
2129         spin_unlock_irq(&dev->power.lock);
2130 }
2131
2132 bool dev_pm_smart_suspend_and_suspended(struct device *dev)
2133 {
2134         return dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) &&
2135                 pm_runtime_status_suspended(dev);
2136 }
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