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 /**
 582  * device_resume_noirq - Execute a "noirq resume" callback for given device.
 583  * @dev: Device to handle.
 584  * @state: PM transition of the system being carried out.
 585  * @async: If true, the device is being resumed asynchronously.
 586  *
 587  * The driver of @dev will not receive interrupts while this function is being
 588  * executed.
 589  */
 590 static int device_resume_noirq(struct device *dev, pm_message_t state, bool async)
 591 {
 592         pm_callback_t callback = NULL;
 593         const char *info = NULL;
 594         bool skip_resume;
 595         int error = 0;
 596
 597         TRACE_DEVICE(dev);
 598         TRACE_RESUME(0);
 599
 600         if (dev->power.syscore || dev->power.direct_complete)
 601                 goto Out;
 602
 603         if (!dev->power.is_noirq_suspended)
 604                 goto Out;
 605
 606         if (!dpm_wait_for_superior(dev, async))
 607                 goto Out;
 608
 609         skip_resume = dev_pm_skip_resume(dev);
 610         /*
 611          * If the driver callback is skipped below or by the middle layer
 612          * callback and device_resume_early() also skips the driver callback for
 613          * this device later, it needs to appear as "suspended" to PM-runtime,
 614          * so change its status accordingly.
 615          *
 616          * Otherwise, the device is going to be resumed, so set its PM-runtime
 617          * status to "active", but do that only if DPM_FLAG_SMART_SUSPEND is set
 618          * to avoid confusing drivers that don't use it.
 619          */
 620         if (skip_resume)
 621                 pm_runtime_set_suspended(dev);
 622         else if (dev_pm_skip_suspend(dev))
 623                 pm_runtime_set_active(dev);
 624
 625         if (dev->pm_domain) {
 626                 info = "noirq power domain ";
 627                 callback = pm_noirq_op(&dev->pm_domain->ops, state);
 628         } else if (dev->type && dev->type->pm) {
 629                 info = "noirq type ";
 630                 callback = pm_noirq_op(dev->type->pm, state);
 631         } else if (dev->class && dev->class->pm) {
 632                 info = "noirq class ";
 633                 callback = pm_noirq_op(dev->class->pm, state);
 634         } else if (dev->bus && dev->bus->pm) {
 635                 info = "noirq bus ";
 636                 callback = pm_noirq_op(dev->bus->pm, state);
 637         }
 638         if (callback)
 639                 goto Run;
 640
 641         if (skip_resume)
 642                 goto Skip;
 643
 644         if (dev->driver && dev->driver->pm) {
 645                 info = "noirq driver ";
 646                 callback = pm_noirq_op(dev->driver->pm, state);
 647         }
 648
 649 Run:
 650         error = dpm_run_callback(callback, dev, state, info);
 651
 652 Skip:
 653         dev->power.is_noirq_suspended = false;
 654
 655 Out:
 656         complete_all(&dev->power.completion);
 657         TRACE_RESUME(error);
 658         return error;
 659 }
 660
 661 static bool is_async(struct device *dev)
 662 {
 663         return dev->power.async_suspend && pm_async_enabled
 664                 && !pm_trace_is_enabled();
 665 }
 666
 667 static bool dpm_async_fn(struct device *dev, async_func_t func)
 668 {
 669         reinit_completion(&dev->power.completion);
 670
 671         if (is_async(dev)) {
 672                 get_device(dev);
 673                 async_schedule_dev(func, dev);
 674                 return true;
 675         }
 676
 677         return false;
 678 }
 679
 680 static void async_resume_noirq(void *data, async_cookie_t cookie)
 681 {
 682         struct device *dev = data;
 683         int error;
 684
 685         error = device_resume_noirq(dev, pm_transition, true);
 686         if (error)
 687                 pm_dev_err(dev, pm_transition, " async", error);
 688
 689         put_device(dev);
 690 }
 691
 692 static void dpm_noirq_resume_devices(pm_message_t state)
 693 {
 694         struct device *dev;
 695         ktime_t starttime = ktime_get();
 696
 697         trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, true);
 698         mutex_lock(&dpm_list_mtx);
 699         pm_transition = state;
 700
 701         /*
 702          * Advanced the async threads upfront,
 703          * in case the starting of async threads is
 704          * delayed by non-async resuming devices.
 705          */
 706         list_for_each_entry(dev, &dpm_noirq_list, power.entry)
 707                 dpm_async_fn(dev, async_resume_noirq);
 708
 709         while (!list_empty(&dpm_noirq_list)) {
 710                 dev = to_device(dpm_noirq_list.next);
 711                 get_device(dev);
 712                 list_move_tail(&dev->power.entry, &dpm_late_early_list);
 713
 714                 mutex_unlock(&dpm_list_mtx);
 715
 716                 if (!is_async(dev)) {
 717                         int error;
 718
 719                         error = device_resume_noirq(dev, state, false);
 720                         if (error) {
 721                                 suspend_stats.failed_resume_noirq++;
 722                                 dpm_save_failed_step(SUSPEND_RESUME_NOIRQ);
 723                                 dpm_save_failed_dev(dev_name(dev));
 724                                 pm_dev_err(dev, state, " noirq", error);
 725                         }
 726                 }
 727
 728                 put_device(dev);
 729
 730                 mutex_lock(&dpm_list_mtx);
 731         }
 732         mutex_unlock(&dpm_list_mtx);
 733         async_synchronize_full();
 734         dpm_show_time(starttime, state, 0, "noirq");
 735         trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, false);
 736 }
 737
 738 /**
 739  * dpm_resume_noirq - Execute "noirq resume" callbacks for all devices.
 740  * @state: PM transition of the system being carried out.
 741  *
 742  * Invoke the "noirq" resume callbacks for all devices in dpm_noirq_list and
 743  * allow device drivers' interrupt handlers to be called.
 744  */
 745 void dpm_resume_noirq(pm_message_t state)
 746 {
 747         dpm_noirq_resume_devices(state);
 748
 749         resume_device_irqs();
 750         device_wakeup_disarm_wake_irqs();
 751 }
 752
 753 /**
 754  * device_resume_early - Execute an "early resume" callback for given device.
 755  * @dev: Device to handle.
 756  * @state: PM transition of the system being carried out.
 757  * @async: If true, the device is being resumed asynchronously.
 758  *
 759  * Runtime PM is disabled for @dev while this function is being executed.
 760  */
 761 static int device_resume_early(struct device *dev, pm_message_t state, bool async)
 762 {
 763         pm_callback_t callback = NULL;
 764         const char *info = NULL;
 765         int error = 0;
 766
 767         TRACE_DEVICE(dev);
 768         TRACE_RESUME(0);
 769
 770         if (dev->power.syscore || dev->power.direct_complete)
 771                 goto Out;
 772
 773         if (!dev->power.is_late_suspended)
 774                 goto Out;
 775
 776         if (!dpm_wait_for_superior(dev, async))
 777                 goto Out;
 778
 779         if (dev->pm_domain) {
 780                 info = "early power domain ";
 781                 callback = pm_late_early_op(&dev->pm_domain->ops, state);
 782         } else if (dev->type && dev->type->pm) {
 783                 info = "early type ";
 784                 callback = pm_late_early_op(dev->type->pm, state);
 785         } else if (dev->class && dev->class->pm) {
 786                 info = "early class ";
 787                 callback = pm_late_early_op(dev->class->pm, state);
 788         } else if (dev->bus && dev->bus->pm) {
 789                 info = "early bus ";
 790                 callback = pm_late_early_op(dev->bus->pm, state);
 791         }
 792         if (callback)
 793                 goto Run;
 794
 795         if (dev_pm_skip_resume(dev))
 796                 goto Skip;
 797
 798         if (dev->driver && dev->driver->pm) {
 799                 info = "early driver ";
 800                 callback = pm_late_early_op(dev->driver->pm, state);
 801         }
 802
 803 Run:
 804         error = dpm_run_callback(callback, dev, state, info);
 805
 806 Skip:
 807         dev->power.is_late_suspended = false;
 808
 809 Out:
 810         TRACE_RESUME(error);
 811
 812         pm_runtime_enable(dev);
 813         complete_all(&dev->power.completion);
 814         return error;
 815 }
 816
 817 static void async_resume_early(void *data, async_cookie_t cookie)
 818 {
 819         struct device *dev = data;
 820         int error;
 821
 822         error = device_resume_early(dev, pm_transition, true);
 823         if (error)
 824                 pm_dev_err(dev, pm_transition, " async", error);
 825
 826         put_device(dev);
 827 }
 828
 829 /**
 830  * dpm_resume_early - Execute "early resume" callbacks for all devices.
 831  * @state: PM transition of the system being carried out.
 832  */
 833 void dpm_resume_early(pm_message_t state)
 834 {
 835         struct device *dev;
 836         ktime_t starttime = ktime_get();
 837
 838         trace_suspend_resume(TPS("dpm_resume_early"), state.event, true);
 839         mutex_lock(&dpm_list_mtx);
 840         pm_transition = state;
 841
 842         /*
 843          * Advanced the async threads upfront,
 844          * in case the starting of async threads is
 845          * delayed by non-async resuming devices.
 846          */
 847         list_for_each_entry(dev, &dpm_late_early_list, power.entry)
 848                 dpm_async_fn(dev, async_resume_early);
 849
 850         while (!list_empty(&dpm_late_early_list)) {
 851                 dev = to_device(dpm_late_early_list.next);
 852                 get_device(dev);
 853                 list_move_tail(&dev->power.entry, &dpm_suspended_list);
 854
 855                 mutex_unlock(&dpm_list_mtx);
 856
 857                 if (!is_async(dev)) {
 858                         int error;
 859
 860                         error = device_resume_early(dev, state, false);
 861                         if (error) {
 862                                 suspend_stats.failed_resume_early++;
 863                                 dpm_save_failed_step(SUSPEND_RESUME_EARLY);
 864                                 dpm_save_failed_dev(dev_name(dev));
 865                                 pm_dev_err(dev, state, " early", error);
 866                         }
 867                 }
 868
 869                 put_device(dev);
 870
 871                 mutex_lock(&dpm_list_mtx);
 872         }
 873         mutex_unlock(&dpm_list_mtx);
 874         async_synchronize_full();
 875         dpm_show_time(starttime, state, 0, "early");
 876         trace_suspend_resume(TPS("dpm_resume_early"), state.event, false);
 877 }
 878
 879 /**
 880  * dpm_resume_start - Execute "noirq" and "early" device callbacks.
 881  * @state: PM transition of the system being carried out.
 882  */
 883 void dpm_resume_start(pm_message_t state)
 884 {
 885         dpm_resume_noirq(state);
 886         dpm_resume_early(state);
 887 }
 888 EXPORT_SYMBOL_GPL(dpm_resume_start);
 889
 890 /**
 891  * device_resume - Execute "resume" callbacks for given device.
 892  * @dev: Device to handle.
 893  * @state: PM transition of the system being carried out.
 894  * @async: If true, the device is being resumed asynchronously.
 895  */
 896 static int device_resume(struct device *dev, pm_message_t state, bool async)
 897 {
 898         pm_callback_t callback = NULL;
 899         const char *info = NULL;
 900         int error = 0;
 901         DECLARE_DPM_WATCHDOG_ON_STACK(wd);
 902
 903         TRACE_DEVICE(dev);
 904         TRACE_RESUME(0);
 905
 906         if (dev->power.syscore)
 907                 goto Complete;
 908
 909         if (dev->power.direct_complete) {
 910                 /* Match the pm_runtime_disable() in __device_suspend(). */
 911                 pm_runtime_enable(dev);
 912                 goto Complete;
 913         }
 914
 915         if (!dpm_wait_for_superior(dev, async))
 916                 goto Complete;
 917
 918         dpm_watchdog_set(&wd, dev);
 919         device_lock(dev);
 920
 921         /*
 922          * This is a fib.  But we'll allow new children to be added below
 923          * a resumed device, even if the device hasn't been completed yet.
 924          */
 925         dev->power.is_prepared = false;
 926
 927         if (!dev->power.is_suspended)
 928                 goto Unlock;
 929
 930         if (dev->pm_domain) {
 931                 info = "power domain ";
 932                 callback = pm_op(&dev->pm_domain->ops, state);
 933                 goto Driver;
 934         }
 935
 936         if (dev->type && dev->type->pm) {
 937                 info = "type ";
 938                 callback = pm_op(dev->type->pm, state);
 939                 goto Driver;
 940         }
 941
 942         if (dev->class && dev->class->pm) {
 943                 info = "class ";
 944                 callback = pm_op(dev->class->pm, state);
 945                 goto Driver;
 946         }
 947
 948         if (dev->bus) {
 949                 if (dev->bus->pm) {
 950                         info = "bus ";
 951                         callback = pm_op(dev->bus->pm, state);
 952                 } else if (dev->bus->resume) {
 953                         info = "legacy bus ";
 954                         callback = dev->bus->resume;
 955                         goto End;
 956                 }
 957         }
 958
 959  Driver:
 960         if (!callback && dev->driver && dev->driver->pm) {
 961                 info = "driver ";
 962                 callback = pm_op(dev->driver->pm, state);
 963         }
 964
 965  End:
 966         error = dpm_run_callback(callback, dev, state, info);
 967         dev->power.is_suspended = false;
 968
 969  Unlock:
 970         device_unlock(dev);
 971         dpm_watchdog_clear(&wd);
 972
 973  Complete:
 974         complete_all(&dev->power.completion);
 975
 976         TRACE_RESUME(error);
 977
 978         return error;
 979 }
 980
 981 static void async_resume(void *data, async_cookie_t cookie)
 982 {
 983         struct device *dev = data;
 984         int error;
 985
 986         error = device_resume(dev, pm_transition, true);
 987         if (error)
 988                 pm_dev_err(dev, pm_transition, " async", error);
 989         put_device(dev);
 990 }
 991
 992 /**
 993  * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
 994  * @state: PM transition of the system being carried out.
 995  *
 996  * Execute the appropriate "resume" callback for all devices whose status
 997  * indicates that they are suspended.
 998  */
 999 void dpm_resume(pm_message_t state)
1000 {
1001         struct device *dev;
1002         ktime_t starttime = ktime_get();
1003
1004         trace_suspend_resume(TPS("dpm_resume"), state.event, true);
1005         might_sleep();
1006
1007         mutex_lock(&dpm_list_mtx);
1008         pm_transition = state;
1009         async_error = 0;
1010
1011         list_for_each_entry(dev, &dpm_suspended_list, power.entry)
1012                 dpm_async_fn(dev, async_resume);
1013
1014         while (!list_empty(&dpm_suspended_list)) {
1015                 dev = to_device(dpm_suspended_list.next);
1016                 get_device(dev);
1017                 if (!is_async(dev)) {
1018                         int error;
1019
1020                         mutex_unlock(&dpm_list_mtx);
1021
1022                         error = device_resume(dev, state, false);
1023                         if (error) {
1024                                 suspend_stats.failed_resume++;
1025                                 dpm_save_failed_step(SUSPEND_RESUME);
1026                                 dpm_save_failed_dev(dev_name(dev));
1027                                 pm_dev_err(dev, state, "", error);
1028                         }
1029
1030                         mutex_lock(&dpm_list_mtx);
1031                 }
1032                 if (!list_empty(&dev->power.entry))
1033                         list_move_tail(&dev->power.entry, &dpm_prepared_list);
1034
1035                 mutex_unlock(&dpm_list_mtx);
1036
1037                 put_device(dev);
1038
1039                 mutex_lock(&dpm_list_mtx);
1040         }
1041         mutex_unlock(&dpm_list_mtx);
1042         async_synchronize_full();
1043         dpm_show_time(starttime, state, 0, NULL);
1044
1045         cpufreq_resume();
1046         devfreq_resume();
1047         trace_suspend_resume(TPS("dpm_resume"), state.event, false);
1048 }
1049
1050 /**
1051  * device_complete - Complete a PM transition for given device.
1052  * @dev: Device to handle.
1053  * @state: PM transition of the system being carried out.
1054  */
1055 static void device_complete(struct device *dev, pm_message_t state)
1056 {
1057         void (*callback)(struct device *) = NULL;
1058         const char *info = NULL;
1059
1060         if (dev->power.syscore)
1061                 goto out;
1062
1063         device_lock(dev);
1064
1065         if (dev->pm_domain) {
1066                 info = "completing power domain ";
1067                 callback = dev->pm_domain->ops.complete;
1068         } else if (dev->type && dev->type->pm) {
1069                 info = "completing type ";
1070                 callback = dev->type->pm->complete;
1071         } else if (dev->class && dev->class->pm) {
1072                 info = "completing class ";
1073                 callback = dev->class->pm->complete;
1074         } else if (dev->bus && dev->bus->pm) {
1075                 info = "completing bus ";
1076                 callback = dev->bus->pm->complete;
1077         }
1078
1079         if (!callback && dev->driver && dev->driver->pm) {
1080                 info = "completing driver ";
1081                 callback = dev->driver->pm->complete;
1082         }
1083
1084         if (callback) {
1085                 pm_dev_dbg(dev, state, info);
1086                 callback(dev);
1087         }
1088
1089         device_unlock(dev);
1090
1091 out:
1092         pm_runtime_put(dev);
1093 }
1094
1095 /**
1096  * dpm_complete - Complete a PM transition for all non-sysdev devices.
1097  * @state: PM transition of the system being carried out.
1098  *
1099  * Execute the ->complete() callbacks for all devices whose PM status is not
1100  * DPM_ON (this allows new devices to be registered).
1101  */
1102 void dpm_complete(pm_message_t state)
1103 {
1104         struct list_head list;
1105
1106         trace_suspend_resume(TPS("dpm_complete"), state.event, true);
1107         might_sleep();
1108
1109         INIT_LIST_HEAD(&list);
1110         mutex_lock(&dpm_list_mtx);
1111         while (!list_empty(&dpm_prepared_list)) {
1112                 struct device *dev = to_device(dpm_prepared_list.prev);
1113
1114                 get_device(dev);
1115                 dev->power.is_prepared = false;
1116                 list_move(&dev->power.entry, &list);
1117
1118                 mutex_unlock(&dpm_list_mtx);
1119
1120                 trace_device_pm_callback_start(dev, "", state.event);
1121                 device_complete(dev, state);
1122                 trace_device_pm_callback_end(dev, 0);
1123
1124                 put_device(dev);
1125
1126                 mutex_lock(&dpm_list_mtx);
1127         }
1128         list_splice(&list, &dpm_list);
1129         mutex_unlock(&dpm_list_mtx);
1130
1131         /* Allow device probing and trigger re-probing of deferred devices */
1132         device_unblock_probing();
1133         trace_suspend_resume(TPS("dpm_complete"), state.event, false);
1134 }
1135
1136 /**
1137  * dpm_resume_end - Execute "resume" callbacks and complete system transition.
1138  * @state: PM transition of the system being carried out.
1139  *
1140  * Execute "resume" callbacks for all devices and complete the PM transition of
1141  * the system.
1142  */
1143 void dpm_resume_end(pm_message_t state)
1144 {
1145         dpm_resume(state);
1146         dpm_complete(state);
1147 }
1148 EXPORT_SYMBOL_GPL(dpm_resume_end);
1149
1150
1151 /*------------------------- Suspend routines -------------------------*/
1152
1153 /**
1154  * resume_event - Return a "resume" message for given "suspend" sleep state.
1155  * @sleep_state: PM message representing a sleep state.
1156  *
1157  * Return a PM message representing the resume event corresponding to given
1158  * sleep state.
1159  */
1160 static pm_message_t resume_event(pm_message_t sleep_state)
1161 {
1162         switch (sleep_state.event) {
1163         case PM_EVENT_SUSPEND:
1164                 return PMSG_RESUME;
1165         case PM_EVENT_FREEZE:
1166         case PM_EVENT_QUIESCE:
1167                 return PMSG_RECOVER;
1168         case PM_EVENT_HIBERNATE:
1169                 return PMSG_RESTORE;
1170         }
1171         return PMSG_ON;
1172 }
1173
1174 static void dpm_superior_set_must_resume(struct device *dev)
1175 {
1176         struct device_link *link;
1177         int idx;
1178
1179         if (dev->parent)
1180                 dev->parent->power.must_resume = true;
1181
1182         idx = device_links_read_lock();
1183
1184         list_for_each_entry_rcu_locked(link, &dev->links.suppliers, c_node)
1185                 link->supplier->power.must_resume = true;
1186
1187         device_links_read_unlock(idx);
1188 }
1189
1190 /**
1191  * __device_suspend_noirq - Execute a "noirq suspend" callback for given device.
1192  * @dev: Device to handle.
1193  * @state: PM transition of the system being carried out.
1194  * @async: If true, the device is being suspended asynchronously.
1195  *
1196  * The driver of @dev will not receive interrupts while this function is being
1197  * executed.
1198  */
1199 static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool async)
1200 {
1201         pm_callback_t callback = NULL;
1202         const char *info = NULL;
1203         int error = 0;
1204
1205         TRACE_DEVICE(dev);
1206         TRACE_SUSPEND(0);
1207
1208         dpm_wait_for_subordinate(dev, async);
1209
1210         if (async_error)
1211                 goto Complete;
1212
1213         if (dev->power.syscore || dev->power.direct_complete)
1214                 goto Complete;
1215
1216         if (dev->pm_domain) {
1217                 info = "noirq power domain ";
1218                 callback = pm_noirq_op(&dev->pm_domain->ops, state);
1219         } else if (dev->type && dev->type->pm) {
1220                 info = "noirq type ";
1221                 callback = pm_noirq_op(dev->type->pm, state);
1222         } else if (dev->class && dev->class->pm) {
1223                 info = "noirq class ";
1224                 callback = pm_noirq_op(dev->class->pm, state);
1225         } else if (dev->bus && dev->bus->pm) {
1226                 info = "noirq bus ";
1227                 callback = pm_noirq_op(dev->bus->pm, state);
1228         }
1229         if (callback)
1230                 goto Run;
1231
1232         if (dev_pm_skip_suspend(dev))
1233                 goto Skip;
1234
1235         if (dev->driver && dev->driver->pm) {
1236                 info = "noirq driver ";
1237                 callback = pm_noirq_op(dev->driver->pm, state);
1238         }
1239
1240 Run:
1241         error = dpm_run_callback(callback, dev, state, info);
1242         if (error) {
1243                 async_error = error;
1244                 goto Complete;
1245         }
1246
1247 Skip:
1248         dev->power.is_noirq_suspended = true;
1249
1250         /*
1251          * Skipping the resume of devices that were in use right before the
1252          * system suspend (as indicated by their PM-runtime usage counters)
1253          * would be suboptimal.  Also resume them if doing that is not allowed
1254          * to be skipped.
1255          */
1256         if (atomic_read(&dev->power.usage_count) > 1 ||
1257             !(dev_pm_test_driver_flags(dev, DPM_FLAG_MAY_SKIP_RESUME) &&
1258               dev->power.may_skip_resume))
1259                 dev->power.must_resume = true;
1260
1261         if (dev->power.must_resume)
1262                 dpm_superior_set_must_resume(dev);
1263
1264 Complete:
1265         complete_all(&dev->power.completion);
1266         TRACE_SUSPEND(error);
1267         return error;
1268 }
1269
1270 static void async_suspend_noirq(void *data, async_cookie_t cookie)
1271 {
1272         struct device *dev = data;
1273         int error;
1274
1275         error = __device_suspend_noirq(dev, pm_transition, true);
1276         if (error) {
1277                 dpm_save_failed_dev(dev_name(dev));
1278                 pm_dev_err(dev, pm_transition, " async", error);
1279         }
1280
1281         put_device(dev);
1282 }
1283
1284 static int device_suspend_noirq(struct device *dev)
1285 {
1286         if (dpm_async_fn(dev, async_suspend_noirq))
1287                 return 0;
1288
1289         return __device_suspend_noirq(dev, pm_transition, false);
1290 }
1291
1292 static int dpm_noirq_suspend_devices(pm_message_t state)
1293 {
1294         ktime_t starttime = ktime_get();
1295         int error = 0;
1296
1297         trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, true);
1298         mutex_lock(&dpm_list_mtx);
1299         pm_transition = state;
1300         async_error = 0;
1301
1302         while (!list_empty(&dpm_late_early_list)) {
1303                 struct device *dev = to_device(dpm_late_early_list.prev);
1304
1305                 get_device(dev);
1306                 mutex_unlock(&dpm_list_mtx);
1307
1308                 error = device_suspend_noirq(dev);
1309
1310                 mutex_lock(&dpm_list_mtx);
1311
1312                 if (error) {
1313                         pm_dev_err(dev, state, " noirq", error);
1314                         dpm_save_failed_dev(dev_name(dev));
1315                 } else if (!list_empty(&dev->power.entry)) {
1316                         list_move(&dev->power.entry, &dpm_noirq_list);
1317                 }
1318
1319                 mutex_unlock(&dpm_list_mtx);
1320
1321                 put_device(dev);
1322
1323                 mutex_lock(&dpm_list_mtx);
1324
1325                 if (error || async_error)
1326                         break;
1327         }
1328         mutex_unlock(&dpm_list_mtx);
1329         async_synchronize_full();
1330         if (!error)
1331                 error = async_error;
1332
1333         if (error) {
1334                 suspend_stats.failed_suspend_noirq++;
1335                 dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ);
1336         }
1337         dpm_show_time(starttime, state, error, "noirq");
1338         trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, false);
1339         return error;
1340 }
1341
1342 /**
1343  * dpm_suspend_noirq - Execute "noirq suspend" callbacks for all devices.
1344  * @state: PM transition of the system being carried out.
1345  *
1346  * Prevent device drivers' interrupt handlers from being called and invoke
1347  * "noirq" suspend callbacks for all non-sysdev devices.
1348  */
1349 int dpm_suspend_noirq(pm_message_t state)
1350 {
1351         int ret;
1352
1353         device_wakeup_arm_wake_irqs();
1354         suspend_device_irqs();
1355
1356         ret = dpm_noirq_suspend_devices(state);
1357         if (ret)
1358                 dpm_resume_noirq(resume_event(state));
1359
1360         return ret;
1361 }
1362
1363 static void dpm_propagate_wakeup_to_parent(struct device *dev)
1364 {
1365         struct device *parent = dev->parent;
1366
1367         if (!parent)
1368                 return;
1369
1370         spin_lock_irq(&parent->power.lock);
1371
1372         if (device_wakeup_path(dev) && !parent->power.ignore_children)
1373                 parent->power.wakeup_path = true;
1374
1375         spin_unlock_irq(&parent->power.lock);
1376 }
1377
1378 /**
1379  * __device_suspend_late - Execute a "late suspend" callback for given device.
1380  * @dev: Device to handle.
1381  * @state: PM transition of the system being carried out.
1382  * @async: If true, the device is being suspended asynchronously.
1383  *
1384  * Runtime PM is disabled for @dev while this function is being executed.
1385  */
1386 static int __device_suspend_late(struct device *dev, pm_message_t state, bool async)
1387 {
1388         pm_callback_t callback = NULL;
1389         const char *info = NULL;
1390         int error = 0;
1391
1392         TRACE_DEVICE(dev);
1393         TRACE_SUSPEND(0);
1394
1395         __pm_runtime_disable(dev, false);
1396
1397         dpm_wait_for_subordinate(dev, async);
1398
1399         if (async_error)
1400                 goto Complete;
1401
1402         if (pm_wakeup_pending()) {
1403                 async_error = -EBUSY;
1404                 goto Complete;
1405         }
1406
1407         if (dev->power.syscore || dev->power.direct_complete)
1408                 goto Complete;
1409
1410         if (dev->pm_domain) {
1411                 info = "late power domain ";
1412                 callback = pm_late_early_op(&dev->pm_domain->ops, state);
1413         } else if (dev->type && dev->type->pm) {
1414                 info = "late type ";
1415                 callback = pm_late_early_op(dev->type->pm, state);
1416         } else if (dev->class && dev->class->pm) {
1417                 info = "late class ";
1418                 callback = pm_late_early_op(dev->class->pm, state);
1419         } else if (dev->bus && dev->bus->pm) {
1420                 info = "late bus ";
1421                 callback = pm_late_early_op(dev->bus->pm, state);
1422         }
1423         if (callback)
1424                 goto Run;
1425
1426         if (dev_pm_skip_suspend(dev))
1427                 goto Skip;
1428
1429         if (dev->driver && dev->driver->pm) {
1430                 info = "late driver ";
1431                 callback = pm_late_early_op(dev->driver->pm, state);
1432         }
1433
1434 Run:
1435         error = dpm_run_callback(callback, dev, state, info);
1436         if (error) {
1437                 async_error = error;
1438                 goto Complete;
1439         }
1440         dpm_propagate_wakeup_to_parent(dev);
1441
1442 Skip:
1443         dev->power.is_late_suspended = true;
1444
1445 Complete:
1446         TRACE_SUSPEND(error);
1447         complete_all(&dev->power.completion);
1448         return error;
1449 }
1450
1451 static void async_suspend_late(void *data, async_cookie_t cookie)
1452 {
1453         struct device *dev = data;
1454         int error;
1455
1456         error = __device_suspend_late(dev, pm_transition, true);
1457         if (error) {
1458                 dpm_save_failed_dev(dev_name(dev));
1459                 pm_dev_err(dev, pm_transition, " async", error);
1460         }
1461         put_device(dev);
1462 }
1463
1464 static int device_suspend_late(struct device *dev)
1465 {
1466         if (dpm_async_fn(dev, async_suspend_late))
1467                 return 0;
1468
1469         return __device_suspend_late(dev, pm_transition, false);
1470 }
1471
1472 /**
1473  * dpm_suspend_late - Execute "late suspend" callbacks for all devices.
1474  * @state: PM transition of the system being carried out.
1475  */
1476 int dpm_suspend_late(pm_message_t state)
1477 {
1478         ktime_t starttime = ktime_get();
1479         int error = 0;
1480
1481         trace_suspend_resume(TPS("dpm_suspend_late"), state.event, true);
1482         wake_up_all_idle_cpus();
1483         mutex_lock(&dpm_list_mtx);
1484         pm_transition = state;
1485         async_error = 0;
1486
1487         while (!list_empty(&dpm_suspended_list)) {
1488                 struct device *dev = to_device(dpm_suspended_list.prev);
1489
1490                 get_device(dev);
1491
1492                 mutex_unlock(&dpm_list_mtx);
1493
1494                 error = device_suspend_late(dev);
1495
1496                 mutex_lock(&dpm_list_mtx);
1497
1498                 if (!list_empty(&dev->power.entry))
1499                         list_move(&dev->power.entry, &dpm_late_early_list);
1500
1501                 if (error) {
1502                         pm_dev_err(dev, state, " late", error);
1503                         dpm_save_failed_dev(dev_name(dev));
1504                 }
1505
1506                 mutex_unlock(&dpm_list_mtx);
1507
1508                 put_device(dev);
1509
1510                 mutex_lock(&dpm_list_mtx);
1511
1512                 if (error || async_error)
1513                         break;
1514         }
1515         mutex_unlock(&dpm_list_mtx);
1516         async_synchronize_full();
1517         if (!error)
1518                 error = async_error;
1519         if (error) {
1520                 suspend_stats.failed_suspend_late++;
1521                 dpm_save_failed_step(SUSPEND_SUSPEND_LATE);
1522                 dpm_resume_early(resume_event(state));
1523         }
1524         dpm_show_time(starttime, state, error, "late");
1525         trace_suspend_resume(TPS("dpm_suspend_late"), state.event, false);
1526         return error;
1527 }
1528
1529 /**
1530  * dpm_suspend_end - Execute "late" and "noirq" device suspend callbacks.
1531  * @state: PM transition of the system being carried out.
1532  */
1533 int dpm_suspend_end(pm_message_t state)
1534 {
1535         ktime_t starttime = ktime_get();
1536         int error;
1537
1538         error = dpm_suspend_late(state);
1539         if (error)
1540                 goto out;
1541
1542         error = dpm_suspend_noirq(state);
1543         if (error)
1544                 dpm_resume_early(resume_event(state));
1545
1546 out:
1547         dpm_show_time(starttime, state, error, "end");
1548         return error;
1549 }
1550 EXPORT_SYMBOL_GPL(dpm_suspend_end);
1551
1552 /**
1553  * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
1554  * @dev: Device to suspend.
1555  * @state: PM transition of the system being carried out.
1556  * @cb: Suspend callback to execute.
1557  * @info: string description of caller.
1558  */
1559 static int legacy_suspend(struct device *dev, pm_message_t state,
1560                           int (*cb)(struct device *dev, pm_message_t state),
1561                           const char *info)
1562 {
1563         int error;
1564         ktime_t calltime;
1565
1566         calltime = initcall_debug_start(dev, cb);
1567
1568         trace_device_pm_callback_start(dev, info, state.event);
1569         error = cb(dev, state);
1570         trace_device_pm_callback_end(dev, error);
1571         suspend_report_result(dev, cb, error);
1572
1573         initcall_debug_report(dev, calltime, cb, error);
1574
1575         return error;
1576 }
1577
1578 static void dpm_clear_superiors_direct_complete(struct device *dev)
1579 {
1580         struct device_link *link;
1581         int idx;
1582
1583         if (dev->parent) {
1584                 spin_lock_irq(&dev->parent->power.lock);
1585                 dev->parent->power.direct_complete = false;
1586                 spin_unlock_irq(&dev->parent->power.lock);
1587         }
1588
1589         idx = device_links_read_lock();
1590
1591         list_for_each_entry_rcu_locked(link, &dev->links.suppliers, c_node) {
1592                 spin_lock_irq(&link->supplier->power.lock);
1593                 link->supplier->power.direct_complete = false;
1594                 spin_unlock_irq(&link->supplier->power.lock);
1595         }
1596
1597         device_links_read_unlock(idx);
1598 }
1599
1600 /**
1601  * __device_suspend - Execute "suspend" callbacks for given device.
1602  * @dev: Device to handle.
1603  * @state: PM transition of the system being carried out.
1604  * @async: If true, the device is being suspended asynchronously.
1605  */
1606 static int __device_suspend(struct device *dev, pm_message_t state, bool async)
1607 {
1608         pm_callback_t callback = NULL;
1609         const char *info = NULL;
1610         int error = 0;
1611         DECLARE_DPM_WATCHDOG_ON_STACK(wd);
1612
1613         TRACE_DEVICE(dev);
1614         TRACE_SUSPEND(0);
1615
1616         dpm_wait_for_subordinate(dev, async);
1617
1618         if (async_error) {
1619                 dev->power.direct_complete = false;
1620                 goto Complete;
1621         }
1622
1623         /*
1624          * Wait for possible runtime PM transitions of the device in progress
1625          * to complete and if there's a runtime resume request pending for it,
1626          * resume it before proceeding with invoking the system-wide suspend
1627          * callbacks for it.
1628          *
1629          * If the system-wide suspend callbacks below change the configuration
1630          * of the device, they must disable runtime PM for it or otherwise
1631          * ensure that its runtime-resume callbacks will not be confused by that
1632          * change in case they are invoked going forward.
1633          */
1634         pm_runtime_barrier(dev);
1635
1636         if (pm_wakeup_pending()) {
1637                 dev->power.direct_complete = false;
1638                 async_error = -EBUSY;
1639                 goto Complete;
1640         }
1641
1642         if (dev->power.syscore)
1643                 goto Complete;
1644
1645         /* Avoid direct_complete to let wakeup_path propagate. */
1646         if (device_may_wakeup(dev) || device_wakeup_path(dev))
1647                 dev->power.direct_complete = false;
1648
1649         if (dev->power.direct_complete) {
1650                 if (pm_runtime_status_suspended(dev)) {
1651                         pm_runtime_disable(dev);
1652                         if (pm_runtime_status_suspended(dev)) {
1653                                 pm_dev_dbg(dev, state, "direct-complete ");
1654                                 goto Complete;
1655                         }
1656
1657                         pm_runtime_enable(dev);
1658                 }
1659                 dev->power.direct_complete = false;
1660         }
1661
1662         dev->power.may_skip_resume = true;
1663         dev->power.must_resume = !dev_pm_test_driver_flags(dev, DPM_FLAG_MAY_SKIP_RESUME);
1664
1665         dpm_watchdog_set(&wd, dev);
1666         device_lock(dev);
1667
1668         if (dev->pm_domain) {
1669                 info = "power domain ";
1670                 callback = pm_op(&dev->pm_domain->ops, state);
1671                 goto Run;
1672         }
1673
1674         if (dev->type && dev->type->pm) {
1675                 info = "type ";
1676                 callback = pm_op(dev->type->pm, state);
1677                 goto Run;
1678         }
1679
1680         if (dev->class && dev->class->pm) {
1681                 info = "class ";
1682                 callback = pm_op(dev->class->pm, state);
1683                 goto Run;
1684         }
1685
1686         if (dev->bus) {
1687                 if (dev->bus->pm) {
1688                         info = "bus ";
1689                         callback = pm_op(dev->bus->pm, state);
1690                 } else if (dev->bus->suspend) {
1691                         pm_dev_dbg(dev, state, "legacy bus ");
1692                         error = legacy_suspend(dev, state, dev->bus->suspend,
1693                                                 "legacy bus ");
1694                         goto End;
1695                 }
1696         }
1697
1698  Run:
1699         if (!callback && dev->driver && dev->driver->pm) {
1700                 info = "driver ";
1701                 callback = pm_op(dev->driver->pm, state);
1702         }
1703
1704         error = dpm_run_callback(callback, dev, state, info);
1705
1706  End:
1707         if (!error) {
1708                 dev->power.is_suspended = true;
1709                 if (device_may_wakeup(dev))
1710                         dev->power.wakeup_path = true;
1711
1712                 dpm_propagate_wakeup_to_parent(dev);
1713                 dpm_clear_superiors_direct_complete(dev);
1714         }
1715
1716         device_unlock(dev);
1717         dpm_watchdog_clear(&wd);
1718
1719  Complete:
1720         if (error)
1721                 async_error = error;
1722
1723         complete_all(&dev->power.completion);
1724         TRACE_SUSPEND(error);
1725         return error;
1726 }
1727
1728 static void async_suspend(void *data, async_cookie_t cookie)
1729 {
1730         struct device *dev = data;
1731         int error;
1732
1733         error = __device_suspend(dev, pm_transition, true);
1734         if (error) {
1735                 dpm_save_failed_dev(dev_name(dev));
1736                 pm_dev_err(dev, pm_transition, " async", error);
1737         }
1738
1739         put_device(dev);
1740 }
1741
1742 static int device_suspend(struct device *dev)
1743 {
1744         if (dpm_async_fn(dev, async_suspend))
1745                 return 0;
1746
1747         return __device_suspend(dev, pm_transition, false);
1748 }
1749
1750 /**
1751  * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
1752  * @state: PM transition of the system being carried out.
1753  */
1754 int dpm_suspend(pm_message_t state)
1755 {
1756         ktime_t starttime = ktime_get();
1757         int error = 0;
1758
1759         trace_suspend_resume(TPS("dpm_suspend"), state.event, true);
1760         might_sleep();
1761
1762         devfreq_suspend();
1763         cpufreq_suspend();
1764
1765         mutex_lock(&dpm_list_mtx);
1766         pm_transition = state;
1767         async_error = 0;
1768         while (!list_empty(&dpm_prepared_list)) {
1769                 struct device *dev = to_device(dpm_prepared_list.prev);
1770
1771                 get_device(dev);
1772
1773                 mutex_unlock(&dpm_list_mtx);
1774
1775                 error = device_suspend(dev);
1776
1777                 mutex_lock(&dpm_list_mtx);
1778
1779                 if (error) {
1780                         pm_dev_err(dev, state, "", error);
1781                         dpm_save_failed_dev(dev_name(dev));
1782                 } else if (!list_empty(&dev->power.entry)) {
1783                         list_move(&dev->power.entry, &dpm_suspended_list);
1784                 }
1785
1786                 mutex_unlock(&dpm_list_mtx);
1787
1788                 put_device(dev);
1789
1790                 mutex_lock(&dpm_list_mtx);
1791
1792                 if (error || async_error)
1793                         break;
1794         }
1795         mutex_unlock(&dpm_list_mtx);
1796         async_synchronize_full();
1797         if (!error)
1798                 error = async_error;
1799         if (error) {
1800                 suspend_stats.failed_suspend++;
1801                 dpm_save_failed_step(SUSPEND_SUSPEND);
1802         }
1803         dpm_show_time(starttime, state, error, NULL);
1804         trace_suspend_resume(TPS("dpm_suspend"), state.event, false);
1805         return error;
1806 }
1807
1808 /**
1809  * device_prepare - Prepare a device for system power transition.
1810  * @dev: Device to handle.
1811  * @state: PM transition of the system being carried out.
1812  *
1813  * Execute the ->prepare() callback(s) for given device.  No new children of the
1814  * device may be registered after this function has returned.
1815  */
1816 static int device_prepare(struct device *dev, pm_message_t state)
1817 {
1818         int (*callback)(struct device *) = NULL;
1819         int ret = 0;
1820
1821         /*
1822          * If a device's parent goes into runtime suspend at the wrong time,
1823          * it won't be possible to resume the device.  To prevent this we
1824          * block runtime suspend here, during the prepare phase, and allow
1825          * it again during the complete phase.
1826          */
1827         pm_runtime_get_noresume(dev);
1828
1829         if (dev->power.syscore)
1830                 return 0;
1831
1832         device_lock(dev);
1833
1834         dev->power.wakeup_path = false;
1835
1836         if (dev->power.no_pm_callbacks)
1837                 goto unlock;
1838
1839         if (dev->pm_domain)
1840                 callback = dev->pm_domain->ops.prepare;
1841         else if (dev->type && dev->type->pm)
1842                 callback = dev->type->pm->prepare;
1843         else if (dev->class && dev->class->pm)
1844                 callback = dev->class->pm->prepare;
1845         else if (dev->bus && dev->bus->pm)
1846                 callback = dev->bus->pm->prepare;
1847
1848         if (!callback && dev->driver && dev->driver->pm)
1849                 callback = dev->driver->pm->prepare;
1850
1851         if (callback)
1852                 ret = callback(dev);
1853
1854 unlock:
1855         device_unlock(dev);
1856
1857         if (ret < 0) {
1858                 suspend_report_result(dev, callback, ret);
1859                 pm_runtime_put(dev);
1860                 return ret;
1861         }
1862         /*
1863          * A positive return value from ->prepare() means "this device appears
1864          * to be runtime-suspended and its state is fine, so if it really is
1865          * runtime-suspended, you can leave it in that state provided that you
1866          * will do the same thing with all of its descendants".  This only
1867          * applies to suspend transitions, however.
1868          */
1869         spin_lock_irq(&dev->power.lock);
1870         dev->power.direct_complete = state.event == PM_EVENT_SUSPEND &&
1871                 (ret > 0 || dev->power.no_pm_callbacks) &&
1872                 !dev_pm_test_driver_flags(dev, DPM_FLAG_NO_DIRECT_COMPLETE);
1873         spin_unlock_irq(&dev->power.lock);
1874         return 0;
1875 }
1876
1877 /**
1878  * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1879  * @state: PM transition of the system being carried out.
1880  *
1881  * Execute the ->prepare() callback(s) for all devices.
1882  */
1883 int dpm_prepare(pm_message_t state)
1884 {
1885         int error = 0;
1886
1887         trace_suspend_resume(TPS("dpm_prepare"), state.event, true);
1888         might_sleep();
1889
1890         /*
1891          * Give a chance for the known devices to complete their probes, before
1892          * disable probing of devices. This sync point is important at least
1893          * at boot time + hibernation restore.
1894          */
1895         wait_for_device_probe();
1896         /*
1897          * It is unsafe if probing of devices will happen during suspend or
1898          * hibernation and system behavior will be unpredictable in this case.
1899          * So, let's prohibit device's probing here and defer their probes
1900          * instead. The normal behavior will be restored in dpm_complete().
1901          */
1902         device_block_probing();
1903
1904         mutex_lock(&dpm_list_mtx);
1905         while (!list_empty(&dpm_list) && !error) {
1906                 struct device *dev = to_device(dpm_list.next);
1907
1908                 get_device(dev);
1909
1910                 mutex_unlock(&dpm_list_mtx);
1911
1912                 trace_device_pm_callback_start(dev, "", state.event);
1913                 error = device_prepare(dev, state);
1914                 trace_device_pm_callback_end(dev, error);
1915
1916                 mutex_lock(&dpm_list_mtx);
1917
1918                 if (!error) {
1919                         dev->power.is_prepared = true;
1920                         if (!list_empty(&dev->power.entry))
1921                                 list_move_tail(&dev->power.entry, &dpm_prepared_list);
1922                 } else if (error == -EAGAIN) {
1923                         error = 0;
1924                 } else {
1925                         dev_info(dev, "not prepared for power transition: code %d\n",
1926                                  error);
1927                 }
1928
1929                 mutex_unlock(&dpm_list_mtx);
1930
1931                 put_device(dev);
1932
1933                 mutex_lock(&dpm_list_mtx);
1934         }
1935         mutex_unlock(&dpm_list_mtx);
1936         trace_suspend_resume(TPS("dpm_prepare"), state.event, false);
1937         return error;
1938 }
1939
1940 /**
1941  * dpm_suspend_start - Prepare devices for PM transition and suspend them.
1942  * @state: PM transition of the system being carried out.
1943  *
1944  * Prepare all non-sysdev devices for system PM transition and execute "suspend"
1945  * callbacks for them.
1946  */
1947 int dpm_suspend_start(pm_message_t state)
1948 {
1949         ktime_t starttime = ktime_get();
1950         int error;
1951
1952         error = dpm_prepare(state);
1953         if (error) {
1954                 suspend_stats.failed_prepare++;
1955                 dpm_save_failed_step(SUSPEND_PREPARE);
1956         } else
1957                 error = dpm_suspend(state);
1958         dpm_show_time(starttime, state, error, "start");
1959         return error;
1960 }
1961 EXPORT_SYMBOL_GPL(dpm_suspend_start);
1962
1963 void __suspend_report_result(const char *function, struct device *dev, void *fn, int ret)
1964 {
1965         if (ret)
1966                 dev_err(dev, "%s(): %pS returns %d\n", function, fn, ret);
1967 }
1968 EXPORT_SYMBOL_GPL(__suspend_report_result);
1969
1970 /**
1971  * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
1972  * @subordinate: Device that needs to wait for @dev.
1973  * @dev: Device to wait for.
1974  */
1975 int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
1976 {
1977         dpm_wait(dev, subordinate->power.async_suspend);
1978         return async_error;
1979 }
1980 EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);
1981
1982 /**
1983  * dpm_for_each_dev - device iterator.
1984  * @data: data for the callback.
1985  * @fn: function to be called for each device.
1986  *
1987  * Iterate over devices in dpm_list, and call @fn for each device,
1988  * passing it @data.
1989  */
1990 void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *))
1991 {
1992         struct device *dev;
1993
1994         if (!fn)
1995                 return;
1996
1997         device_pm_lock();
1998         list_for_each_entry(dev, &dpm_list, power.entry)
1999                 fn(dev, data);
2000         device_pm_unlock();
2001 }
2002 EXPORT_SYMBOL_GPL(dpm_for_each_dev);
2003
2004 static bool pm_ops_is_empty(const struct dev_pm_ops *ops)
2005 {
2006         if (!ops)
2007                 return true;
2008
2009         return !ops->prepare &&
2010                !ops->suspend &&
2011                !ops->suspend_late &&
2012                !ops->suspend_noirq &&
2013                !ops->resume_noirq &&
2014                !ops->resume_early &&
2015                !ops->resume &&
2016                !ops->complete;
2017 }
2018
2019 void device_pm_check_callbacks(struct device *dev)
2020 {
2021         unsigned long flags;
2022
2023         spin_lock_irqsave(&dev->power.lock, flags);
2024         dev->power.no_pm_callbacks =
2025                 (!dev->bus || (pm_ops_is_empty(dev->bus->pm) &&
2026                  !dev->bus->suspend && !dev->bus->resume)) &&
2027                 (!dev->class || pm_ops_is_empty(dev->class->pm)) &&
2028                 (!dev->type || pm_ops_is_empty(dev->type->pm)) &&
2029                 (!dev->pm_domain || pm_ops_is_empty(&dev->pm_domain->ops)) &&
2030                 (!dev->driver || (pm_ops_is_empty(dev->driver->pm) &&
2031                  !dev->driver->suspend && !dev->driver->resume));
2032         spin_unlock_irqrestore(&dev->power.lock, flags);
2033 }
2034
2035 bool dev_pm_skip_suspend(struct device *dev)
2036 {
2037         return dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) &&
2038                 pm_runtime_status_suspended(dev);
2039 }