drivers/base/power/main.c

   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/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 #define list_for_each_entry_rcu_locked(pos, head, member) \
  44         list_for_each_entry_rcu(pos, head, member, \
  45                         device_links_read_lock_held())
  46
  47 /*
  48  * The entries in the dpm_list list are in a depth first order, simply
  49  * because children are guaranteed to be discovered after parents, and
  50  * are inserted at the back of the list on discovery.
  51  *
  52  * Since device_pm_add() may be called with a device lock held,
  53  * we must never try to acquire a device lock while holding
  54  * dpm_list_mutex.
  55  */
  56
  57 LIST_HEAD(dpm_list);
  58 static LIST_HEAD(dpm_prepared_list);
  59 static LIST_HEAD(dpm_suspended_list);
  60 static LIST_HEAD(dpm_late_early_list);
  61 static LIST_HEAD(dpm_noirq_list);
  62
  63 struct suspend_stats suspend_stats;
  64 static DEFINE_MUTEX(dpm_list_mtx);
  65 static pm_message_t pm_transition;
  66
  67 static int async_error;
  68
  69 static const char *pm_verb(int event)
  70 {
  71         switch (event) {
  72         case PM_EVENT_SUSPEND:
  73                 return "suspend";
  74         case PM_EVENT_RESUME:
  75                 return "resume";
  76         case PM_EVENT_FREEZE:
  77                 return "freeze";
  78         case PM_EVENT_QUIESCE:
  79                 return "quiesce";
  80         case PM_EVENT_HIBERNATE:
  81                 return "hibernate";
  82         case PM_EVENT_THAW:
  83                 return "thaw";
  84         case PM_EVENT_RESTORE:
  85                 return "restore";
  86         case PM_EVENT_RECOVER:
  87                 return "recover";
  88         default:
  89                 return "(unknown PM event)";
  90         }
  91 }
  92
  93 /**
  94  * device_pm_sleep_init - Initialize system suspend-related device fields.
  95  * @dev: Device object being initialized.
  96  */
  97 void device_pm_sleep_init(struct device *dev)
  98 {
  99         dev->power.is_prepared = false;
 100         dev->power.is_suspended = false;
 101         dev->power.is_noirq_suspended = false;
 102         dev->power.is_late_suspended = false;
 103         init_completion(&dev->power.completion);
 104         complete_all(&dev->power.completion);
 105         dev->power.wakeup = NULL;
 106         INIT_LIST_HEAD(&dev->power.entry);
 107 }
 108
 109 /**
 110  * device_pm_lock - Lock the list of active devices used by the PM core.
 111  */
 112 void device_pm_lock(void)
 113 {
 114         mutex_lock(&dpm_list_mtx);
 115 }
 116
 117 /**
 118  * device_pm_unlock - Unlock the list of active devices used by the PM core.
 119  */
 120 void device_pm_unlock(void)
 121 {
 122         mutex_unlock(&dpm_list_mtx);
 123 }
 124
 125 /**
 126  * device_pm_add - Add a device to the PM core's list of active devices.
 127  * @dev: Device to add to the list.
 128  */
 129 void device_pm_add(struct device *dev)
 130 {
 131         /* Skip PM setup/initialization. */
 132         if (device_pm_not_required(dev))
 133                 return;
 134
 135         pr_debug("Adding info for %s:%s\n",
 136                  dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 137         device_pm_check_callbacks(dev);
 138         mutex_lock(&dpm_list_mtx);
 139         if (dev->parent && dev->parent->power.is_prepared)
 140                 dev_warn(dev, "parent %s should not be sleeping\n",
 141                         dev_name(dev->parent));
 142         list_add_tail(&dev->power.entry, &dpm_list);
 143         dev->power.in_dpm_list = true;
 144         mutex_unlock(&dpm_list_mtx);
 145 }
 146
 147 /**
 148  * device_pm_remove - Remove a device from the PM core's list of active devices.
 149  * @dev: Device to be removed from the list.
 150  */
 151 void device_pm_remove(struct device *dev)
 152 {
 153         if (device_pm_not_required(dev))
 154                 return;
 155
 156         pr_debug("Removing info for %s:%s\n",
 157                  dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 158         complete_all(&dev->power.completion);
 159         mutex_lock(&dpm_list_mtx);
 160         list_del_init(&dev->power.entry);
 161         dev->power.in_dpm_list = false;
 162         mutex_unlock(&dpm_list_mtx);
 163         device_wakeup_disable(dev);
 164         pm_runtime_remove(dev);
 165         device_pm_check_callbacks(dev);
 166 }
 167
 168 /**
 169  * device_pm_move_before - Move device in the PM core's list of active devices.
 170  * @deva: Device to move in dpm_list.
 171  * @devb: Device @deva should come before.
 172  */
 173 void device_pm_move_before(struct device *deva, struct device *devb)
 174 {
 175         pr_debug("Moving %s:%s before %s:%s\n",
 176                  deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
 177                  devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
 178         /* Delete deva from dpm_list and reinsert before devb. */
 179         list_move_tail(&deva->power.entry, &devb->power.entry);
 180 }
 181
 182 /**
 183  * device_pm_move_after - Move device in the PM core's list of active devices.
 184  * @deva: Device to move in dpm_list.
 185  * @devb: Device @deva should come after.
 186  */
 187 void device_pm_move_after(struct device *deva, struct device *devb)
 188 {
 189         pr_debug("Moving %s:%s after %s:%s\n",
 190                  deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
 191                  devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
 192         /* Delete deva from dpm_list and reinsert after devb. */
 193         list_move(&deva->power.entry, &devb->power.entry);
 194 }
 195
 196 /**
 197  * device_pm_move_last - Move device to end of the PM core's list of devices.
 198  * @dev: Device to move in dpm_list.
 199  */
 200 void device_pm_move_last(struct device *dev)
 201 {
 202         pr_debug("Moving %s:%s to end of list\n",
 203                  dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 204         list_move_tail(&dev->power.entry, &dpm_list);
 205 }
 206
 207 static ktime_t initcall_debug_start(struct device *dev, void *cb)
 208 {
 209         if (!pm_print_times_enabled)
 210                 return 0;
 211
 212         dev_info(dev, "calling %pS @ %i, parent: %s\n", cb,
 213                  task_pid_nr(current),
 214                  dev->parent ? dev_name(dev->parent) : "none");
 215         return ktime_get();
 216 }
 217
 218 static void initcall_debug_report(struct device *dev, ktime_t calltime,
 219                                   void *cb, int error)
 220 {
 221         ktime_t rettime;
 222
 223         if (!pm_print_times_enabled)
 224                 return;
 225
 226         rettime = ktime_get();
 227         dev_info(dev, "%pS returned %d after %Ld usecs\n", cb, error,
 228                  (unsigned long long)ktime_us_delta(rettime, calltime));
 229 }
 230
 231 /**
 232  * dpm_wait - Wait for a PM operation to complete.
 233  * @dev: Device to wait for.
 234  * @async: If unset, wait only if the device's power.async_suspend flag is set.
 235  */
 236 static void dpm_wait(struct device *dev, bool async)
 237 {
 238         if (!dev)
 239                 return;
 240
 241         if (async || (pm_async_enabled && dev->power.async_suspend))
 242                 wait_for_completion(&dev->power.completion);
 243 }
 244
 245 static int dpm_wait_fn(struct device *dev, void *async_ptr)
 246 {
 247         dpm_wait(dev, *((bool *)async_ptr));
 248         return 0;
 249 }
 250
 251 static void dpm_wait_for_children(struct device *dev, bool async)
 252 {
 253        device_for_each_child(dev, &async, dpm_wait_fn);
 254 }
 255
 256 static void dpm_wait_for_suppliers(struct device *dev, bool async)
 257 {
 258         struct device_link *link;
 259         int idx;
 260
 261         idx = device_links_read_lock();
 262
 263         /*
 264          * If the supplier goes away right after we've checked the link to it,
 265          * we'll wait for its completion to change the state, but that's fine,
 266          * because the only things that will block as a result are the SRCU
 267          * callbacks freeing the link objects for the links in the list we're
 268          * walking.
 269          */
 270         list_for_each_entry_rcu_locked(link, &dev->links.suppliers, c_node)
 271                 if (READ_ONCE(link->status) != DL_STATE_DORMANT)
 272                         dpm_wait(link->supplier, async);
 273
 274         device_links_read_unlock(idx);
 275 }
 276
 277 static bool dpm_wait_for_superior(struct device *dev, bool async)
 278 {
 279         struct device *parent;
 280
 281         /*
 282          * If the device is resumed asynchronously and the parent's callback
 283          * deletes both the device and the parent itself, the parent object may
 284          * be freed while this function is running, so avoid that by reference
 285          * counting the parent once more unless the device has been deleted
 286          * already (in which case return right away).
 287          */
 288         mutex_lock(&dpm_list_mtx);
 289
 290         if (!device_pm_initialized(dev)) {
 291                 mutex_unlock(&dpm_list_mtx);
 292                 return false;
 293         }
 294
 295         parent = get_device(dev->parent);
 296
 297         mutex_unlock(&dpm_list_mtx);
 298
 299         dpm_wait(parent, async);
 300         put_device(parent);
 301
 302         dpm_wait_for_suppliers(dev, async);
 303
 304         /*
 305          * If the parent's callback has deleted the device, attempting to resume
 306          * it would be invalid, so avoid doing that then.
 307          */
 308         return device_pm_initialized(dev);
 309 }
 310
 311 static void dpm_wait_for_consumers(struct device *dev, bool async)
 312 {
 313         struct device_link *link;
 314         int idx;
 315
 316         idx = device_links_read_lock();
 317
 318         /*
 319          * The status of a device link can only be changed from "dormant" by a
 320          * probe, but that cannot happen during system suspend/resume.  In
 321          * theory it can change to "dormant" at that time, but then it is
 322          * reasonable to wait for the target device anyway (eg. if it goes
 323          * away, it's better to wait for it to go away completely and then
 324          * continue instead of trying to continue in parallel with its
 325          * unregistration).
 326          */
 327         list_for_each_entry_rcu_locked(link, &dev->links.consumers, s_node)
 328                 if (READ_ONCE(link->status) != DL_STATE_DORMANT)
 329                         dpm_wait(link->consumer, async);
 330
 331         device_links_read_unlock(idx);
 332 }
 333
 334 static void dpm_wait_for_subordinate(struct device *dev, bool async)
 335 {
 336         dpm_wait_for_children(dev, async);
 337         dpm_wait_for_consumers(dev, async);
 338 }
 339
 340 /**
 341  * pm_op - Return the PM operation appropriate for given PM event.
 342  * @ops: PM operations to choose from.
 343  * @state: PM transition of the system being carried out.
 344  */
 345 static pm_callback_t pm_op(const struct dev_pm_ops *ops, pm_message_t state)
 346 {
 347         switch (state.event) {
 348 #ifdef CONFIG_SUSPEND
 349         case PM_EVENT_SUSPEND:
 350                 return ops->suspend;
 351         case PM_EVENT_RESUME:
 352                 return ops->resume;
 353 #endif /* CONFIG_SUSPEND */
 354 #ifdef CONFIG_HIBERNATE_CALLBACKS
 355         case PM_EVENT_FREEZE:
 356         case PM_EVENT_QUIESCE:
 357                 return ops->freeze;
 358         case PM_EVENT_HIBERNATE:
 359                 return ops->poweroff;
 360         case PM_EVENT_THAW:
 361         case PM_EVENT_RECOVER:
 362                 return ops->thaw;
 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 driver flags: %x\n", info, pm_verb(state.event),
 442                 ((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
 443                 ", may wakeup" : "", dev->power.driver_flags);
 444 }
 445
 446 static void pm_dev_err(struct device *dev, pm_message_t state, const char *info,
 447                         int error)
 448 {
 449         dev_err(dev, "failed to %s%s: error %d\n", pm_verb(state.event), info,
 450                 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(dev, 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, KERN_EMERG);
 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  * dev_pm_skip_resume - System-wide device resume optimization check.
 562  * @dev: Target device.
 563  *
 564  * Return:
 565  * - %false if the transition under way is RESTORE.
 566  * - Return value of dev_pm_skip_suspend() if the transition under way is THAW.
 567  * - The logical negation of %power.must_resume otherwise (that is, when the
 568  *   transition under way is RESUME).
 569  */
 570 bool dev_pm_skip_resume(struct device *dev)
 571 {
 572         if (pm_transition.event == PM_EVENT_RESTORE)
 573                 return false;
 574
 575         if (pm_transition.event == PM_EVENT_THAW)
 576                 return dev_pm_skip_suspend(dev);
 577
 578         return !dev->power.must_resume;
 579 }
 580
 581 static bool is_async(struct device *dev)
 582 {
 583         return dev->power.async_suspend && pm_async_enabled
 584                 && !pm_trace_is_enabled();
 585 }
 586
 587 static bool dpm_async_fn(struct device *dev, async_func_t func)
 588 {
 589         reinit_completion(&dev->power.completion);
 590
 591         if (is_async(dev)) {
 592                 dev->power.async_in_progress = true;
 593
 594                 get_device(dev);
 595
 596                 if (async_schedule_dev_nocall(func, dev))
 597                         return true;
 598
 599                 put_device(dev);
 600         }
 601         /*
 602          * Because async_schedule_dev_nocall() above has returned false or it
 603          * has not been called at all, func() is not running and it is safe to
 604          * update the async_in_progress flag without extra synchronization.
 605          */
 606         dev->power.async_in_progress = false;
 607         return false;
 608 }
 609
 610 /**
 611  * device_resume_noirq - Execute a "noirq resume" callback for given device.
 612  * @dev: Device to handle.
 613  * @state: PM transition of the system being carried out.
 614  * @async: If true, the device is being resumed asynchronously.
 615  *
 616  * The driver of @dev will not receive interrupts while this function is being
 617  * executed.
 618  */
 619 static void device_resume_noirq(struct device *dev, pm_message_t state, bool async)
 620 {
 621         pm_callback_t callback = NULL;
 622         const char *info = NULL;
 623         bool skip_resume;
 624         int error = 0;
 625
 626         TRACE_DEVICE(dev);
 627         TRACE_RESUME(0);
 628
 629         if (dev->power.syscore || dev->power.direct_complete)
 630                 goto Out;
 631
 632         if (!dev->power.is_noirq_suspended)
 633                 goto Out;
 634
 635         if (!dpm_wait_for_superior(dev, async))
 636                 goto Out;
 637
 638         skip_resume = dev_pm_skip_resume(dev);
 639         /*
 640          * If the driver callback is skipped below or by the middle layer
 641          * callback and device_resume_early() also skips the driver callback for
 642          * this device later, it needs to appear as "suspended" to PM-runtime,
 643          * so change its status accordingly.
 644          *
 645          * Otherwise, the device is going to be resumed, so set its PM-runtime
 646          * status to "active", but do that only if DPM_FLAG_SMART_SUSPEND is set
 647          * to avoid confusing drivers that don't use it.
 648          */
 649         if (skip_resume)
 650                 pm_runtime_set_suspended(dev);
 651         else if (dev_pm_skip_suspend(dev))
 652                 pm_runtime_set_active(dev);
 653
 654         if (dev->pm_domain) {
 655                 info = "noirq power domain ";
 656                 callback = pm_noirq_op(&dev->pm_domain->ops, state);
 657         } else if (dev->type && dev->type->pm) {
 658                 info = "noirq type ";
 659                 callback = pm_noirq_op(dev->type->pm, state);
 660         } else if (dev->class && dev->class->pm) {
 661                 info = "noirq class ";
 662                 callback = pm_noirq_op(dev->class->pm, state);
 663         } else if (dev->bus && dev->bus->pm) {
 664                 info = "noirq bus ";
 665                 callback = pm_noirq_op(dev->bus->pm, state);
 666         }
 667         if (callback)
 668                 goto Run;
 669
 670         if (skip_resume)
 671                 goto Skip;
 672
 673         if (dev->driver && dev->driver->pm) {
 674                 info = "noirq driver ";
 675                 callback = pm_noirq_op(dev->driver->pm, state);
 676         }
 677
 678 Run:
 679         error = dpm_run_callback(callback, dev, state, info);
 680
 681 Skip:
 682         dev->power.is_noirq_suspended = false;
 683
 684 Out:
 685         complete_all(&dev->power.completion);
 686         TRACE_RESUME(error);
 687
 688         if (error) {
 689                 dpm_save_failed_step(SUSPEND_RESUME_NOIRQ);
 690                 dpm_save_failed_dev(dev_name(dev));
 691                 pm_dev_err(dev, state, async ? " async noirq" : " noirq", error);
 692         }
 693 }
 694
 695 static void async_resume_noirq(void *data, async_cookie_t cookie)
 696 {
 697         struct device *dev = data;
 698
 699         device_resume_noirq(dev, pm_transition, true);
 700         put_device(dev);
 701 }
 702
 703 static void dpm_noirq_resume_devices(pm_message_t state)
 704 {
 705         struct device *dev;
 706         ktime_t starttime = ktime_get();
 707
 708         trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, true);
 709         mutex_lock(&dpm_list_mtx);
 710         pm_transition = state;
 711
 712         /*
 713          * Trigger the resume of "async" devices upfront so they don't have to
 714          * wait for the "non-async" ones they don't depend on.
 715          */
 716         list_for_each_entry(dev, &dpm_noirq_list, power.entry)
 717                 dpm_async_fn(dev, async_resume_noirq);
 718
 719         while (!list_empty(&dpm_noirq_list)) {
 720                 dev = to_device(dpm_noirq_list.next);
 721                 list_move_tail(&dev->power.entry, &dpm_late_early_list);
 722
 723                 if (!dev->power.async_in_progress) {
 724                         get_device(dev);
 725
 726                         mutex_unlock(&dpm_list_mtx);
 727
 728                         device_resume_noirq(dev, state, false);
 729
 730                         put_device(dev);
 731
 732                         mutex_lock(&dpm_list_mtx);
 733                 }
 734         }
 735         mutex_unlock(&dpm_list_mtx);
 736         async_synchronize_full();
 737         dpm_show_time(starttime, state, 0, "noirq");
 738         trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, false);
 739 }
 740
 741 /**
 742  * dpm_resume_noirq - Execute "noirq resume" callbacks for all devices.
 743  * @state: PM transition of the system being carried out.
 744  *
 745  * Invoke the "noirq" resume callbacks for all devices in dpm_noirq_list and
 746  * allow device drivers' interrupt handlers to be called.
 747  */
 748 void dpm_resume_noirq(pm_message_t state)
 749 {
 750         dpm_noirq_resume_devices(state);
 751
 752         resume_device_irqs();
 753         device_wakeup_disarm_wake_irqs();
 754 }
 755
 756 /**
 757  * device_resume_early - Execute an "early resume" callback for given device.
 758  * @dev: Device to handle.
 759  * @state: PM transition of the system being carried out.
 760  * @async: If true, the device is being resumed asynchronously.
 761  *
 762  * Runtime PM is disabled for @dev while this function is being executed.
 763  */
 764 static void device_resume_early(struct device *dev, pm_message_t state, bool async)
 765 {
 766         pm_callback_t callback = NULL;
 767         const char *info = NULL;
 768         int error = 0;
 769
 770         TRACE_DEVICE(dev);
 771         TRACE_RESUME(0);
 772
 773         if (dev->power.syscore || dev->power.direct_complete)
 774                 goto Out;
 775
 776         if (!dev->power.is_late_suspended)
 777                 goto Out;
 778
 779         if (!dpm_wait_for_superior(dev, async))
 780                 goto Out;
 781
 782         if (dev->pm_domain) {
 783                 info = "early power domain ";
 784                 callback = pm_late_early_op(&dev->pm_domain->ops, state);
 785         } else if (dev->type && dev->type->pm) {
 786                 info = "early type ";
 787                 callback = pm_late_early_op(dev->type->pm, state);
 788         } else if (dev->class && dev->class->pm) {
 789                 info = "early class ";
 790                 callback = pm_late_early_op(dev->class->pm, state);
 791         } else if (dev->bus && dev->bus->pm) {
 792                 info = "early bus ";
 793                 callback = pm_late_early_op(dev->bus->pm, state);
 794         }
 795         if (callback)
 796                 goto Run;
 797
 798         if (dev_pm_skip_resume(dev))
 799                 goto Skip;
 800
 801         if (dev->driver && dev->driver->pm) {
 802                 info = "early driver ";
 803                 callback = pm_late_early_op(dev->driver->pm, state);
 804         }
 805
 806 Run:
 807         error = dpm_run_callback(callback, dev, state, info);
 808
 809 Skip:
 810         dev->power.is_late_suspended = false;
 811
 812 Out:
 813         TRACE_RESUME(error);
 814
 815         pm_runtime_enable(dev);
 816         complete_all(&dev->power.completion);
 817
 818         if (error) {
 819                 dpm_save_failed_step(SUSPEND_RESUME_EARLY);
 820                 dpm_save_failed_dev(dev_name(dev));
 821                 pm_dev_err(dev, state, async ? " async early" : " early", error);
 822         }
 823 }
 824
 825 static void async_resume_early(void *data, async_cookie_t cookie)
 826 {
 827         struct device *dev = data;
 828
 829         device_resume_early(dev, pm_transition, true);
 830         put_device(dev);
 831 }
 832
 833 /**
 834  * dpm_resume_early - Execute "early resume" callbacks for all devices.
 835  * @state: PM transition of the system being carried out.
 836  */
 837 void dpm_resume_early(pm_message_t state)
 838 {
 839         struct device *dev;
 840         ktime_t starttime = ktime_get();
 841
 842         trace_suspend_resume(TPS("dpm_resume_early"), state.event, true);
 843         mutex_lock(&dpm_list_mtx);
 844         pm_transition = state;
 845
 846         /*
 847          * Trigger the resume of "async" devices upfront so they don't have to
 848          * wait for the "non-async" ones they don't depend on.
 849          */
 850         list_for_each_entry(dev, &dpm_late_early_list, power.entry)
 851                 dpm_async_fn(dev, async_resume_early);
 852
 853         while (!list_empty(&dpm_late_early_list)) {
 854                 dev = to_device(dpm_late_early_list.next);
 855                 list_move_tail(&dev->power.entry, &dpm_suspended_list);
 856
 857                 if (!dev->power.async_in_progress) {
 858                         get_device(dev);
 859
 860                         mutex_unlock(&dpm_list_mtx);
 861
 862                         device_resume_early(dev, state, false);
 863
 864                         put_device(dev);
 865
 866                         mutex_lock(&dpm_list_mtx);
 867                 }
 868         }
 869         mutex_unlock(&dpm_list_mtx);
 870         async_synchronize_full();
 871         dpm_show_time(starttime, state, 0, "early");
 872         trace_suspend_resume(TPS("dpm_resume_early"), state.event, false);
 873 }
 874
 875 /**
 876  * dpm_resume_start - Execute "noirq" and "early" device callbacks.
 877  * @state: PM transition of the system being carried out.
 878  */
 879 void dpm_resume_start(pm_message_t state)
 880 {
 881         dpm_resume_noirq(state);
 882         dpm_resume_early(state);
 883 }
 884 EXPORT_SYMBOL_GPL(dpm_resume_start);
 885
 886 /**
 887  * device_resume - Execute "resume" callbacks for given device.
 888  * @dev: Device to handle.
 889  * @state: PM transition of the system being carried out.
 890  * @async: If true, the device is being resumed asynchronously.
 891  */
 892 static void device_resume(struct device *dev, pm_message_t state, bool async)
 893 {
 894         pm_callback_t callback = NULL;
 895         const char *info = NULL;
 896         int error = 0;
 897         DECLARE_DPM_WATCHDOG_ON_STACK(wd);
 898
 899         TRACE_DEVICE(dev);
 900         TRACE_RESUME(0);
 901
 902         if (dev->power.syscore)
 903                 goto Complete;
 904
 905         if (dev->power.direct_complete) {
 906                 /* Match the pm_runtime_disable() in __device_suspend(). */
 907                 pm_runtime_enable(dev);
 908                 goto Complete;
 909         }
 910
 911         if (!dpm_wait_for_superior(dev, async))
 912                 goto Complete;
 913
 914         dpm_watchdog_set(&wd, dev);
 915         device_lock(dev);
 916
 917         /*
 918          * This is a fib.  But we'll allow new children to be added below
 919          * a resumed device, even if the device hasn't been completed yet.
 920          */
 921         dev->power.is_prepared = false;
 922
 923         if (!dev->power.is_suspended)
 924                 goto Unlock;
 925
 926         if (dev->pm_domain) {
 927                 info = "power domain ";
 928                 callback = pm_op(&dev->pm_domain->ops, state);
 929                 goto Driver;
 930         }
 931
 932         if (dev->type && dev->type->pm) {
 933                 info = "type ";
 934                 callback = pm_op(dev->type->pm, state);
 935                 goto Driver;
 936         }
 937
 938         if (dev->class && dev->class->pm) {
 939                 info = "class ";
 940                 callback = pm_op(dev->class->pm, state);
 941                 goto Driver;
 942         }
 943
 944         if (dev->bus) {
 945                 if (dev->bus->pm) {
 946                         info = "bus ";
 947                         callback = pm_op(dev->bus->pm, state);
 948                 } else if (dev->bus->resume) {
 949                         info = "legacy bus ";
 950                         callback = dev->bus->resume;
 951                         goto End;
 952                 }
 953         }
 954
 955  Driver:
 956         if (!callback && dev->driver && dev->driver->pm) {
 957                 info = "driver ";
 958                 callback = pm_op(dev->driver->pm, state);
 959         }
 960
 961  End:
 962         error = dpm_run_callback(callback, dev, state, info);
 963         dev->power.is_suspended = false;
 964
 965  Unlock:
 966         device_unlock(dev);
 967         dpm_watchdog_clear(&wd);
 968
 969  Complete:
 970         complete_all(&dev->power.completion);
 971
 972         TRACE_RESUME(error);
 973
 974         if (error) {
 975                 dpm_save_failed_step(SUSPEND_RESUME);
 976                 dpm_save_failed_dev(dev_name(dev));
 977                 pm_dev_err(dev, state, async ? " async" : "", error);
 978         }
 979 }
 980
 981 static void async_resume(void *data, async_cookie_t cookie)
 982 {
 983         struct device *dev = data;
 984
 985         device_resume(dev, pm_transition, true);
 986         put_device(dev);
 987 }
 988
 989 /**
 990  * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
 991  * @state: PM transition of the system being carried out.
 992  *
 993  * Execute the appropriate "resume" callback for all devices whose status
 994  * indicates that they are suspended.
 995  */
 996 void dpm_resume(pm_message_t state)
 997 {
 998         struct device *dev;
 999         ktime_t starttime = ktime_get();
1000
1001         trace_suspend_resume(TPS("dpm_resume"), state.event, true);
1002         might_sleep();
1003
1004         mutex_lock(&dpm_list_mtx);
1005         pm_transition = state;
1006         async_error = 0;
1007
1008         /*
1009          * Trigger the resume of "async" devices upfront so they don't have to
1010          * wait for the "non-async" ones they don't depend on.
1011          */
1012         list_for_each_entry(dev, &dpm_suspended_list, power.entry)
1013                 dpm_async_fn(dev, async_resume);
1014
1015         while (!list_empty(&dpm_suspended_list)) {
1016                 dev = to_device(dpm_suspended_list.next);
1017                 list_move_tail(&dev->power.entry, &dpm_prepared_list);
1018
1019                 if (!dev->power.async_in_progress) {
1020                         get_device(dev);
1021
1022                         mutex_unlock(&dpm_list_mtx);
1023
1024                         device_resume(dev, state, false);
1025
1026                         put_device(dev);
1027
1028                         mutex_lock(&dpm_list_mtx);
1029                 }
1030         }
1031         mutex_unlock(&dpm_list_mtx);
1032         async_synchronize_full();
1033         dpm_show_time(starttime, state, 0, NULL);
1034
1035         cpufreq_resume();
1036         devfreq_resume();
1037         trace_suspend_resume(TPS("dpm_resume"), state.event, false);
1038 }
1039
1040 /**
1041  * device_complete - Complete a PM transition for given device.
1042  * @dev: Device to handle.
1043  * @state: PM transition of the system being carried out.
1044  */
1045 static void device_complete(struct device *dev, pm_message_t state)
1046 {
1047         void (*callback)(struct device *) = NULL;
1048         const char *info = NULL;
1049
1050         if (dev->power.syscore)
1051                 goto out;
1052
1053         device_lock(dev);
1054
1055         if (dev->pm_domain) {
1056                 info = "completing power domain ";
1057                 callback = dev->pm_domain->ops.complete;
1058         } else if (dev->type && dev->type->pm) {
1059                 info = "completing type ";
1060                 callback = dev->type->pm->complete;
1061         } else if (dev->class && dev->class->pm) {
1062                 info = "completing class ";
1063                 callback = dev->class->pm->complete;
1064         } else if (dev->bus && dev->bus->pm) {
1065                 info = "completing bus ";
1066                 callback = dev->bus->pm->complete;
1067         }
1068
1069         if (!callback && dev->driver && dev->driver->pm) {
1070                 info = "completing driver ";
1071                 callback = dev->driver->pm->complete;
1072         }
1073
1074         if (callback) {
1075                 pm_dev_dbg(dev, state, info);
1076                 callback(dev);
1077         }
1078
1079         device_unlock(dev);
1080
1081 out:
1082         pm_runtime_put(dev);
1083 }
1084
1085 /**
1086  * dpm_complete - Complete a PM transition for all non-sysdev devices.
1087  * @state: PM transition of the system being carried out.
1088  *
1089  * Execute the ->complete() callbacks for all devices whose PM status is not
1090  * DPM_ON (this allows new devices to be registered).
1091  */
1092 void dpm_complete(pm_message_t state)
1093 {
1094         struct list_head list;
1095
1096         trace_suspend_resume(TPS("dpm_complete"), state.event, true);
1097         might_sleep();
1098
1099         INIT_LIST_HEAD(&list);
1100         mutex_lock(&dpm_list_mtx);
1101         while (!list_empty(&dpm_prepared_list)) {
1102                 struct device *dev = to_device(dpm_prepared_list.prev);
1103
1104                 get_device(dev);
1105                 dev->power.is_prepared = false;
1106                 list_move(&dev->power.entry, &list);
1107
1108                 mutex_unlock(&dpm_list_mtx);
1109
1110                 trace_device_pm_callback_start(dev, "", state.event);
1111                 device_complete(dev, state);
1112                 trace_device_pm_callback_end(dev, 0);
1113
1114                 put_device(dev);
1115
1116                 mutex_lock(&dpm_list_mtx);
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  */
1133 void dpm_resume_end(pm_message_t state)
1134 {
1135         dpm_resume(state);
1136         dpm_complete(state);
1137 }
1138 EXPORT_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  */
1150 static 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
1164 static 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  */
1189 static 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
1230 Run:
1231         error = dpm_run_callback(callback, dev, state, info);
1232         if (error) {
1233                 async_error = error;
1234                 goto Complete;
1235         }
1236
1237 Skip:
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
1254 Complete:
1255         complete_all(&dev->power.completion);
1256         TRACE_SUSPEND(error);
1257         return error;
1258 }
1259
1260 static void async_suspend_noirq(void *data, async_cookie_t cookie)
1261 {
1262         struct device *dev = 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
1274 static 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
1282 static 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
1302                 if (error) {
1303                         pm_dev_err(dev, state, " noirq", error);
1304                         dpm_save_failed_dev(dev_name(dev));
1305                 } else if (!list_empty(&dev->power.entry)) {
1306                         list_move(&dev->power.entry, &dpm_noirq_list);
1307                 }
1308
1309                 mutex_unlock(&dpm_list_mtx);
1310
1311                 put_device(dev);
1312
1313                 mutex_lock(&dpm_list_mtx);
1314
1315                 if (error || async_error)
1316                         break;
1317         }
1318         mutex_unlock(&dpm_list_mtx);
1319         async_synchronize_full();
1320         if (!error)
1321                 error = async_error;
1322
1323         if (error)
1324                 dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ);
1325
1326         dpm_show_time(starttime, state, error, "noirq");
1327         trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, false);
1328         return error;
1329 }
1330
1331 /**
1332  * dpm_suspend_noirq - Execute "noirq suspend" callbacks for all devices.
1333  * @state: PM transition of the system being carried out.
1334  *
1335  * Prevent device drivers' interrupt handlers from being called and invoke
1336  * "noirq" suspend callbacks for all non-sysdev devices.
1337  */
1338 int dpm_suspend_noirq(pm_message_t state)
1339 {
1340         int ret;
1341
1342         device_wakeup_arm_wake_irqs();
1343         suspend_device_irqs();
1344
1345         ret = dpm_noirq_suspend_devices(state);
1346         if (ret)
1347                 dpm_resume_noirq(resume_event(state));
1348
1349         return ret;
1350 }
1351
1352 static void dpm_propagate_wakeup_to_parent(struct device *dev)
1353 {
1354         struct device *parent = dev->parent;
1355
1356         if (!parent)
1357                 return;
1358
1359         spin_lock_irq(&parent->power.lock);
1360
1361         if (device_wakeup_path(dev) && !parent->power.ignore_children)
1362                 parent->power.wakeup_path = true;
1363
1364         spin_unlock_irq(&parent->power.lock);
1365 }
1366
1367 /**
1368  * __device_suspend_late - Execute a "late suspend" callback for given device.
1369  * @dev: Device to handle.
1370  * @state: PM transition of the system being carried out.
1371  * @async: If true, the device is being suspended asynchronously.
1372  *
1373  * Runtime PM is disabled for @dev while this function is being executed.
1374  */
1375 static int __device_suspend_late(struct device *dev, pm_message_t state, bool async)
1376 {
1377         pm_callback_t callback = NULL;
1378         const char *info = NULL;
1379         int error = 0;
1380
1381         TRACE_DEVICE(dev);
1382         TRACE_SUSPEND(0);
1383
1384         __pm_runtime_disable(dev, false);
1385
1386         dpm_wait_for_subordinate(dev, async);
1387
1388         if (async_error)
1389                 goto Complete;
1390
1391         if (pm_wakeup_pending()) {
1392                 async_error = -EBUSY;
1393                 goto Complete;
1394         }
1395
1396         if (dev->power.syscore || dev->power.direct_complete)
1397                 goto Complete;
1398
1399         if (dev->pm_domain) {
1400                 info = "late power domain ";
1401                 callback = pm_late_early_op(&dev->pm_domain->ops, state);
1402         } else if (dev->type && dev->type->pm) {
1403                 info = "late type ";
1404                 callback = pm_late_early_op(dev->type->pm, state);
1405         } else if (dev->class && dev->class->pm) {
1406                 info = "late class ";
1407                 callback = pm_late_early_op(dev->class->pm, state);
1408         } else if (dev->bus && dev->bus->pm) {
1409                 info = "late bus ";
1410                 callback = pm_late_early_op(dev->bus->pm, state);
1411         }
1412         if (callback)
1413                 goto Run;
1414
1415         if (dev_pm_skip_suspend(dev))
1416                 goto Skip;
1417
1418         if (dev->driver && dev->driver->pm) {
1419                 info = "late driver ";
1420                 callback = pm_late_early_op(dev->driver->pm, state);
1421         }
1422
1423 Run:
1424         error = dpm_run_callback(callback, dev, state, info);
1425         if (error) {
1426                 async_error = error;
1427                 goto Complete;
1428         }
1429         dpm_propagate_wakeup_to_parent(dev);
1430
1431 Skip:
1432         dev->power.is_late_suspended = true;
1433
1434 Complete:
1435         TRACE_SUSPEND(error);
1436         complete_all(&dev->power.completion);
1437         return error;
1438 }
1439
1440 static void async_suspend_late(void *data, async_cookie_t cookie)
1441 {
1442         struct device *dev = data;
1443         int error;
1444
1445         error = __device_suspend_late(dev, pm_transition, true);
1446         if (error) {
1447                 dpm_save_failed_dev(dev_name(dev));
1448                 pm_dev_err(dev, pm_transition, " async", error);
1449         }
1450         put_device(dev);
1451 }
1452
1453 static int device_suspend_late(struct device *dev)
1454 {
1455         if (dpm_async_fn(dev, async_suspend_late))
1456                 return 0;
1457
1458         return __device_suspend_late(dev, pm_transition, false);
1459 }
1460
1461 /**
1462  * dpm_suspend_late - Execute "late suspend" callbacks for all devices.
1463  * @state: PM transition of the system being carried out.
1464  */
1465 int dpm_suspend_late(pm_message_t state)
1466 {
1467         ktime_t starttime = ktime_get();
1468         int error = 0;
1469
1470         trace_suspend_resume(TPS("dpm_suspend_late"), state.event, true);
1471         wake_up_all_idle_cpus();
1472         mutex_lock(&dpm_list_mtx);
1473         pm_transition = state;
1474         async_error = 0;
1475
1476         while (!list_empty(&dpm_suspended_list)) {
1477                 struct device *dev = to_device(dpm_suspended_list.prev);
1478
1479                 get_device(dev);
1480
1481                 mutex_unlock(&dpm_list_mtx);
1482
1483                 error = device_suspend_late(dev);
1484
1485                 mutex_lock(&dpm_list_mtx);
1486
1487                 if (!list_empty(&dev->power.entry))
1488                         list_move(&dev->power.entry, &dpm_late_early_list);
1489
1490                 if (error) {
1491                         pm_dev_err(dev, state, " late", error);
1492                         dpm_save_failed_dev(dev_name(dev));
1493                 }
1494
1495                 mutex_unlock(&dpm_list_mtx);
1496
1497                 put_device(dev);
1498
1499                 mutex_lock(&dpm_list_mtx);
1500
1501                 if (error || async_error)
1502                         break;
1503         }
1504         mutex_unlock(&dpm_list_mtx);
1505         async_synchronize_full();
1506         if (!error)
1507                 error = async_error;
1508
1509         if (error) {
1510                 dpm_save_failed_step(SUSPEND_SUSPEND_LATE);
1511                 dpm_resume_early(resume_event(state));
1512         }
1513         dpm_show_time(starttime, state, error, "late");
1514         trace_suspend_resume(TPS("dpm_suspend_late"), state.event, false);
1515         return error;
1516 }
1517
1518 /**
1519  * dpm_suspend_end - Execute "late" and "noirq" device suspend callbacks.
1520  * @state: PM transition of the system being carried out.
1521  */
1522 int dpm_suspend_end(pm_message_t state)
1523 {
1524         ktime_t starttime = ktime_get();
1525         int error;
1526
1527         error = dpm_suspend_late(state);
1528         if (error)
1529                 goto out;
1530
1531         error = dpm_suspend_noirq(state);
1532         if (error)
1533                 dpm_resume_early(resume_event(state));
1534
1535 out:
1536         dpm_show_time(starttime, state, error, "end");
1537         return error;
1538 }
1539 EXPORT_SYMBOL_GPL(dpm_suspend_end);
1540
1541 /**
1542  * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
1543  * @dev: Device to suspend.
1544  * @state: PM transition of the system being carried out.
1545  * @cb: Suspend callback to execute.
1546  * @info: string description of caller.
1547  */
1548 static int legacy_suspend(struct device *dev, pm_message_t state,
1549                           int (*cb)(struct device *dev, pm_message_t state),
1550                           const char *info)
1551 {
1552         int error;
1553         ktime_t calltime;
1554
1555         calltime = initcall_debug_start(dev, cb);
1556
1557         trace_device_pm_callback_start(dev, info, state.event);
1558         error = cb(dev, state);
1559         trace_device_pm_callback_end(dev, error);
1560         suspend_report_result(dev, cb, error);
1561
1562         initcall_debug_report(dev, calltime, cb, error);
1563
1564         return error;
1565 }
1566
1567 static void dpm_clear_superiors_direct_complete(struct device *dev)
1568 {
1569         struct device_link *link;
1570         int idx;
1571
1572         if (dev->parent) {
1573                 spin_lock_irq(&dev->parent->power.lock);
1574                 dev->parent->power.direct_complete = false;
1575                 spin_unlock_irq(&dev->parent->power.lock);
1576         }
1577
1578         idx = device_links_read_lock();
1579
1580         list_for_each_entry_rcu_locked(link, &dev->links.suppliers, c_node) {
1581                 spin_lock_irq(&link->supplier->power.lock);
1582                 link->supplier->power.direct_complete = false;
1583                 spin_unlock_irq(&link->supplier->power.lock);
1584         }
1585
1586         device_links_read_unlock(idx);
1587 }
1588
1589 /**
1590  * __device_suspend - Execute "suspend" callbacks for given device.
1591  * @dev: Device to handle.
1592  * @state: PM transition of the system being carried out.
1593  * @async: If true, the device is being suspended asynchronously.
1594  */
1595 static int __device_suspend(struct device *dev, pm_message_t state, bool async)
1596 {
1597         pm_callback_t callback = NULL;
1598         const char *info = NULL;
1599         int error = 0;
1600         DECLARE_DPM_WATCHDOG_ON_STACK(wd);
1601
1602         TRACE_DEVICE(dev);
1603         TRACE_SUSPEND(0);
1604
1605         dpm_wait_for_subordinate(dev, async);
1606
1607         if (async_error) {
1608                 dev->power.direct_complete = false;
1609                 goto Complete;
1610         }
1611
1612         /*
1613          * Wait for possible runtime PM transitions of the device in progress
1614          * to complete and if there's a runtime resume request pending for it,
1615          * resume it before proceeding with invoking the system-wide suspend
1616          * callbacks for it.
1617          *
1618          * If the system-wide suspend callbacks below change the configuration
1619          * of the device, they must disable runtime PM for it or otherwise
1620          * ensure that its runtime-resume callbacks will not be confused by that
1621          * change in case they are invoked going forward.
1622          */
1623         pm_runtime_barrier(dev);
1624
1625         if (pm_wakeup_pending()) {
1626                 dev->power.direct_complete = false;
1627                 async_error = -EBUSY;
1628                 goto Complete;
1629         }
1630
1631         if (dev->power.syscore)
1632                 goto Complete;
1633
1634         /* Avoid direct_complete to let wakeup_path propagate. */
1635         if (device_may_wakeup(dev) || device_wakeup_path(dev))
1636                 dev->power.direct_complete = false;
1637
1638         if (dev->power.direct_complete) {
1639                 if (pm_runtime_status_suspended(dev)) {
1640                         pm_runtime_disable(dev);
1641                         if (pm_runtime_status_suspended(dev)) {
1642                                 pm_dev_dbg(dev, state, "direct-complete ");
1643                                 goto Complete;
1644                         }
1645
1646                         pm_runtime_enable(dev);
1647                 }
1648                 dev->power.direct_complete = false;
1649         }
1650
1651         dev->power.may_skip_resume = true;
1652         dev->power.must_resume = !dev_pm_test_driver_flags(dev, DPM_FLAG_MAY_SKIP_RESUME);
1653
1654         dpm_watchdog_set(&wd, dev);
1655         device_lock(dev);
1656
1657         if (dev->pm_domain) {
1658                 info = "power domain ";
1659                 callback = pm_op(&dev->pm_domain->ops, state);
1660                 goto Run;
1661         }
1662
1663         if (dev->type && dev->type->pm) {
1664                 info = "type ";
1665                 callback = pm_op(dev->type->pm, state);
1666                 goto Run;
1667         }
1668
1669         if (dev->class && dev->class->pm) {
1670                 info = "class ";
1671                 callback = pm_op(dev->class->pm, state);
1672                 goto Run;
1673         }
1674
1675         if (dev->bus) {
1676                 if (dev->bus->pm) {
1677                         info = "bus ";
1678                         callback = pm_op(dev->bus->pm, state);
1679                 } else if (dev->bus->suspend) {
1680                         pm_dev_dbg(dev, state, "legacy bus ");
1681                         error = legacy_suspend(dev, state, dev->bus->suspend,
1682                                                 "legacy bus ");
1683                         goto End;
1684                 }
1685         }
1686
1687  Run:
1688         if (!callback && dev->driver && dev->driver->pm) {
1689                 info = "driver ";
1690                 callback = pm_op(dev->driver->pm, state);
1691         }
1692
1693         error = dpm_run_callback(callback, dev, state, info);
1694
1695  End:
1696         if (!error) {
1697                 dev->power.is_suspended = true;
1698                 if (device_may_wakeup(dev))
1699                         dev->power.wakeup_path = true;
1700
1701                 dpm_propagate_wakeup_to_parent(dev);
1702                 dpm_clear_superiors_direct_complete(dev);
1703         }
1704
1705         device_unlock(dev);
1706         dpm_watchdog_clear(&wd);
1707
1708  Complete:
1709         if (error)
1710                 async_error = error;
1711
1712         complete_all(&dev->power.completion);
1713         TRACE_SUSPEND(error);
1714         return error;
1715 }
1716
1717 static void async_suspend(void *data, async_cookie_t cookie)
1718 {
1719         struct device *dev = data;
1720         int error;
1721
1722         error = __device_suspend(dev, pm_transition, true);
1723         if (error) {
1724                 dpm_save_failed_dev(dev_name(dev));
1725                 pm_dev_err(dev, pm_transition, " async", error);
1726         }
1727
1728         put_device(dev);
1729 }
1730
1731 static int device_suspend(struct device *dev)
1732 {
1733         if (dpm_async_fn(dev, async_suspend))
1734                 return 0;
1735
1736         return __device_suspend(dev, pm_transition, false);
1737 }
1738
1739 /**
1740  * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
1741  * @state: PM transition of the system being carried out.
1742  */
1743 int dpm_suspend(pm_message_t state)
1744 {
1745         ktime_t starttime = ktime_get();
1746         int error = 0;
1747
1748         trace_suspend_resume(TPS("dpm_suspend"), state.event, true);
1749         might_sleep();
1750
1751         devfreq_suspend();
1752         cpufreq_suspend();
1753
1754         mutex_lock(&dpm_list_mtx);
1755         pm_transition = state;
1756         async_error = 0;
1757         while (!list_empty(&dpm_prepared_list)) {
1758                 struct device *dev = to_device(dpm_prepared_list.prev);
1759
1760                 get_device(dev);
1761
1762                 mutex_unlock(&dpm_list_mtx);
1763
1764                 error = device_suspend(dev);
1765
1766                 mutex_lock(&dpm_list_mtx);
1767
1768                 if (error) {
1769                         pm_dev_err(dev, state, "", error);
1770                         dpm_save_failed_dev(dev_name(dev));
1771                 } else if (!list_empty(&dev->power.entry)) {
1772                         list_move(&dev->power.entry, &dpm_suspended_list);
1773                 }
1774
1775                 mutex_unlock(&dpm_list_mtx);
1776
1777                 put_device(dev);
1778
1779                 mutex_lock(&dpm_list_mtx);
1780
1781                 if (error || async_error)
1782                         break;
1783         }
1784         mutex_unlock(&dpm_list_mtx);
1785         async_synchronize_full();
1786         if (!error)
1787                 error = async_error;
1788
1789         if (error)
1790                 dpm_save_failed_step(SUSPEND_SUSPEND);
1791
1792         dpm_show_time(starttime, state, error, NULL);
1793         trace_suspend_resume(TPS("dpm_suspend"), state.event, false);
1794         return error;
1795 }
1796
1797 /**
1798  * device_prepare - Prepare a device for system power transition.
1799  * @dev: Device to handle.
1800  * @state: PM transition of the system being carried out.
1801  *
1802  * Execute the ->prepare() callback(s) for given device.  No new children of the
1803  * device may be registered after this function has returned.
1804  */
1805 static int device_prepare(struct device *dev, pm_message_t state)
1806 {
1807         int (*callback)(struct device *) = NULL;
1808         int ret = 0;
1809
1810         /*
1811          * If a device's parent goes into runtime suspend at the wrong time,
1812          * it won't be possible to resume the device.  To prevent this we
1813          * block runtime suspend here, during the prepare phase, and allow
1814          * it again during the complete phase.
1815          */
1816         pm_runtime_get_noresume(dev);
1817
1818         if (dev->power.syscore)
1819                 return 0;
1820
1821         device_lock(dev);
1822
1823         dev->power.wakeup_path = false;
1824
1825         if (dev->power.no_pm_callbacks)
1826                 goto unlock;
1827
1828         if (dev->pm_domain)
1829                 callback = dev->pm_domain->ops.prepare;
1830         else if (dev->type && dev->type->pm)
1831                 callback = dev->type->pm->prepare;
1832         else if (dev->class && dev->class->pm)
1833                 callback = dev->class->pm->prepare;
1834         else if (dev->bus && dev->bus->pm)
1835                 callback = dev->bus->pm->prepare;
1836
1837         if (!callback && dev->driver && dev->driver->pm)
1838                 callback = dev->driver->pm->prepare;
1839
1840         if (callback)
1841                 ret = callback(dev);
1842
1843 unlock:
1844         device_unlock(dev);
1845
1846         if (ret < 0) {
1847                 suspend_report_result(dev, callback, ret);
1848                 pm_runtime_put(dev);
1849                 return ret;
1850         }
1851         /*
1852          * A positive return value from ->prepare() means "this device appears
1853          * to be runtime-suspended and its state is fine, so if it really is
1854          * runtime-suspended, you can leave it in that state provided that you
1855          * will do the same thing with all of its descendants".  This only
1856          * applies to suspend transitions, however.
1857          */
1858         spin_lock_irq(&dev->power.lock);
1859         dev->power.direct_complete = state.event == PM_EVENT_SUSPEND &&
1860                 (ret > 0 || dev->power.no_pm_callbacks) &&
1861                 !dev_pm_test_driver_flags(dev, DPM_FLAG_NO_DIRECT_COMPLETE);
1862         spin_unlock_irq(&dev->power.lock);
1863         return 0;
1864 }
1865
1866 /**
1867  * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1868  * @state: PM transition of the system being carried out.
1869  *
1870  * Execute the ->prepare() callback(s) for all devices.
1871  */
1872 int dpm_prepare(pm_message_t state)
1873 {
1874         int error = 0;
1875
1876         trace_suspend_resume(TPS("dpm_prepare"), state.event, true);
1877         might_sleep();
1878
1879         /*
1880          * Give a chance for the known devices to complete their probes, before
1881          * disable probing of devices. This sync point is important at least
1882          * at boot time + hibernation restore.
1883          */
1884         wait_for_device_probe();
1885         /*
1886          * It is unsafe if probing of devices will happen during suspend or
1887          * hibernation and system behavior will be unpredictable in this case.
1888          * So, let's prohibit device's probing here and defer their probes
1889          * instead. The normal behavior will be restored in dpm_complete().
1890          */
1891         device_block_probing();
1892
1893         mutex_lock(&dpm_list_mtx);
1894         while (!list_empty(&dpm_list) && !error) {
1895                 struct device *dev = to_device(dpm_list.next);
1896
1897                 get_device(dev);
1898
1899                 mutex_unlock(&dpm_list_mtx);
1900
1901                 trace_device_pm_callback_start(dev, "", state.event);
1902                 error = device_prepare(dev, state);
1903                 trace_device_pm_callback_end(dev, error);
1904
1905                 mutex_lock(&dpm_list_mtx);
1906
1907                 if (!error) {
1908                         dev->power.is_prepared = true;
1909                         if (!list_empty(&dev->power.entry))
1910                                 list_move_tail(&dev->power.entry, &dpm_prepared_list);
1911                 } else if (error == -EAGAIN) {
1912                         error = 0;
1913                 } else {
1914                         dev_info(dev, "not prepared for power transition: code %d\n",
1915                                  error);
1916                 }
1917
1918                 mutex_unlock(&dpm_list_mtx);
1919
1920                 put_device(dev);
1921
1922                 mutex_lock(&dpm_list_mtx);
1923         }
1924         mutex_unlock(&dpm_list_mtx);
1925         trace_suspend_resume(TPS("dpm_prepare"), state.event, false);
1926         return error;
1927 }
1928
1929 /**
1930  * dpm_suspend_start - Prepare devices for PM transition and suspend them.
1931  * @state: PM transition of the system being carried out.
1932  *
1933  * Prepare all non-sysdev devices for system PM transition and execute "suspend"
1934  * callbacks for them.
1935  */
1936 int dpm_suspend_start(pm_message_t state)
1937 {
1938         ktime_t starttime = ktime_get();
1939         int error;
1940
1941         error = dpm_prepare(state);
1942         if (error)
1943                 dpm_save_failed_step(SUSPEND_PREPARE);
1944         else
1945                 error = dpm_suspend(state);
1946
1947         dpm_show_time(starttime, state, error, "start");
1948         return error;
1949 }
1950 EXPORT_SYMBOL_GPL(dpm_suspend_start);
1951
1952 void __suspend_report_result(const char *function, struct device *dev, void *fn, int ret)
1953 {
1954         if (ret)
1955                 dev_err(dev, "%s(): %pS returns %d\n", function, fn, ret);
1956 }
1957 EXPORT_SYMBOL_GPL(__suspend_report_result);
1958
1959 /**
1960  * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
1961  * @subordinate: Device that needs to wait for @dev.
1962  * @dev: Device to wait for.
1963  */
1964 int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
1965 {
1966         dpm_wait(dev, subordinate->power.async_suspend);
1967         return async_error;
1968 }
1969 EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);
1970
1971 /**
1972  * dpm_for_each_dev - device iterator.
1973  * @data: data for the callback.
1974  * @fn: function to be called for each device.
1975  *
1976  * Iterate over devices in dpm_list, and call @fn for each device,
1977  * passing it @data.
1978  */
1979 void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *))
1980 {
1981         struct device *dev;
1982
1983         if (!fn)
1984                 return;
1985
1986         device_pm_lock();
1987         list_for_each_entry(dev, &dpm_list, power.entry)
1988                 fn(dev, data);
1989         device_pm_unlock();
1990 }
1991 EXPORT_SYMBOL_GPL(dpm_for_each_dev);
1992
1993 static bool pm_ops_is_empty(const struct dev_pm_ops *ops)
1994 {
1995         if (!ops)
1996                 return true;
1997
1998         return !ops->prepare &&
1999                !ops->suspend &&
2000                !ops->suspend_late &&
2001                !ops->suspend_noirq &&
2002                !ops->resume_noirq &&
2003                !ops->resume_early &&
2004                !ops->resume &&
2005                !ops->complete;
2006 }
2007
2008 void device_pm_check_callbacks(struct device *dev)
2009 {
2010         unsigned long flags;
2011
2012         spin_lock_irqsave(&dev->power.lock, flags);
2013         dev->power.no_pm_callbacks =
2014                 (!dev->bus || (pm_ops_is_empty(dev->bus->pm) &&
2015                  !dev->bus->suspend && !dev->bus->resume)) &&
2016                 (!dev->class || pm_ops_is_empty(dev->class->pm)) &&
2017                 (!dev->type || pm_ops_is_empty(dev->type->pm)) &&
2018                 (!dev->pm_domain || pm_ops_is_empty(&dev->pm_domain->ops)) &&
2019                 (!dev->driver || (pm_ops_is_empty(dev->driver->pm) &&
2020                  !dev->driver->suspend && !dev->driver->resume));
2021         spin_unlock_irqrestore(&dev->power.lock, flags);
2022 }
2023
2024 bool dev_pm_skip_suspend(struct device *dev)
2025 {
2026         return dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) &&
2027                 pm_runtime_status_suspended(dev);
2028 }