drivers/base/power/main.c

   1 /*
   2  * drivers/base/power/main.c - Where the driver meets power management.
   3  *
   4  * Copyright (c) 2003 Patrick Mochel
   5  * Copyright (c) 2003 Open Source Development Lab
   6  *
   7  * This file is released under the GPLv2
   8  *
   9  *
  10  * The driver model core calls device_pm_add() when a device is registered.
  11  * This will initialize the embedded device_pm_info object in the device
  12  * and add it to the list of power-controlled devices. sysfs entries for
  13  * controlling device power management will also be added.
  14  *
  15  * A separate list is used for keeping track of power info, because the power
  16  * domain dependencies may differ from the ancestral dependencies that the
  17  * subsystem list maintains.
  18  */
  19
  20 #include <linux/device.h>
  21 #include <linux/kallsyms.h>
  22 #include <linux/export.h>
  23 #include <linux/mutex.h>
  24 #include <linux/pm.h>
  25 #include <linux/pm_runtime.h>
  26 #include <linux/pm-trace.h>
  27 #include <linux/pm_wakeirq.h>
  28 #include <linux/interrupt.h>
  29 #include <linux/sched.h>
  30 #include <linux/sched/debug.h>
  31 #include <linux/async.h>
  32 #include <linux/suspend.h>
  33 #include <trace/events/power.h>
  34 #include <linux/cpufreq.h>
  35 #include <linux/cpuidle.h>
  36 #include <linux/timer.h>
  37
  38 #include "../base.h"
  39 #include "power.h"
  40
  41 typedef int (*pm_callback_t)(struct device *);
  42
  43 /*
  44  * The entries in the dpm_list list are in a depth first order, simply
  45  * because children are guaranteed to be discovered after parents, and
  46  * are inserted at the back of the list on discovery.
  47  *
  48  * Since device_pm_add() may be called with a device lock held,
  49  * we must never try to acquire a device lock while holding
  50  * dpm_list_mutex.
  51  */
  52
  53 LIST_HEAD(dpm_list);
  54 static LIST_HEAD(dpm_prepared_list);
  55 static LIST_HEAD(dpm_suspended_list);
  56 static LIST_HEAD(dpm_late_early_list);
  57 static LIST_HEAD(dpm_noirq_list);
  58
  59 struct suspend_stats suspend_stats;
  60 static DEFINE_MUTEX(dpm_list_mtx);
  61 static pm_message_t pm_transition;
  62
  63 static int async_error;
  64
  65 static const char *pm_verb(int event)
  66 {
  67         switch (event) {
  68         case PM_EVENT_SUSPEND:
  69                 return "suspend";
  70         case PM_EVENT_RESUME:
  71                 return "resume";
  72         case PM_EVENT_FREEZE:
  73                 return "freeze";
  74         case PM_EVENT_QUIESCE:
  75                 return "quiesce";
  76         case PM_EVENT_HIBERNATE:
  77                 return "hibernate";
  78         case PM_EVENT_THAW:
  79                 return "thaw";
  80         case PM_EVENT_RESTORE:
  81                 return "restore";
  82         case PM_EVENT_RECOVER:
  83                 return "recover";
  84         default:
  85                 return "(unknown PM event)";
  86         }
  87 }
  88
  89 /**
  90  * device_pm_sleep_init - Initialize system suspend-related device fields.
  91  * @dev: Device object being initialized.
  92  */
  93 void device_pm_sleep_init(struct device *dev)
  94 {
  95         dev->power.is_prepared = false;
  96         dev->power.is_suspended = false;
  97         dev->power.is_noirq_suspended = false;
  98         dev->power.is_late_suspended = false;
  99         init_completion(&dev->power.completion);
 100         complete_all(&dev->power.completion);
 101         dev->power.wakeup = NULL;
 102         INIT_LIST_HEAD(&dev->power.entry);
 103 }
 104
 105 /**
 106  * device_pm_lock - Lock the list of active devices used by the PM core.
 107  */
 108 void device_pm_lock(void)
 109 {
 110         mutex_lock(&dpm_list_mtx);
 111 }
 112
 113 /**
 114  * device_pm_unlock - Unlock the list of active devices used by the PM core.
 115  */
 116 void device_pm_unlock(void)
 117 {
 118         mutex_unlock(&dpm_list_mtx);
 119 }
 120
 121 /**
 122  * device_pm_add - Add a device to the PM core's list of active devices.
 123  * @dev: Device to add to the list.
 124  */
 125 void device_pm_add(struct device *dev)
 126 {
 127         pr_debug("PM: Adding info for %s:%s\n",
 128                  dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 129         device_pm_check_callbacks(dev);
 130         mutex_lock(&dpm_list_mtx);
 131         if (dev->parent && dev->parent->power.is_prepared)
 132                 dev_warn(dev, "parent %s should not be sleeping\n",
 133                         dev_name(dev->parent));
 134         list_add_tail(&dev->power.entry, &dpm_list);
 135         dev->power.in_dpm_list = true;
 136         mutex_unlock(&dpm_list_mtx);
 137 }
 138
 139 /**
 140  * device_pm_remove - Remove a device from the PM core's list of active devices.
 141  * @dev: Device to be removed from the list.
 142  */
 143 void device_pm_remove(struct device *dev)
 144 {
 145         pr_debug("PM: Removing info for %s:%s\n",
 146                  dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 147         complete_all(&dev->power.completion);
 148         mutex_lock(&dpm_list_mtx);
 149         list_del_init(&dev->power.entry);
 150         dev->power.in_dpm_list = false;
 151         mutex_unlock(&dpm_list_mtx);
 152         device_wakeup_disable(dev);
 153         pm_runtime_remove(dev);
 154         device_pm_check_callbacks(dev);
 155 }
 156
 157 /**
 158  * device_pm_move_before - Move device in the PM core's list of active devices.
 159  * @deva: Device to move in dpm_list.
 160  * @devb: Device @deva should come before.
 161  */
 162 void device_pm_move_before(struct device *deva, struct device *devb)
 163 {
 164         pr_debug("PM: Moving %s:%s before %s:%s\n",
 165                  deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
 166                  devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
 167         /* Delete deva from dpm_list and reinsert before devb. */
 168         list_move_tail(&deva->power.entry, &devb->power.entry);
 169 }
 170
 171 /**
 172  * device_pm_move_after - Move device in the PM core's list of active devices.
 173  * @deva: Device to move in dpm_list.
 174  * @devb: Device @deva should come after.
 175  */
 176 void device_pm_move_after(struct device *deva, struct device *devb)
 177 {
 178         pr_debug("PM: Moving %s:%s after %s:%s\n",
 179                  deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
 180                  devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
 181         /* Delete deva from dpm_list and reinsert after devb. */
 182         list_move(&deva->power.entry, &devb->power.entry);
 183 }
 184
 185 /**
 186  * device_pm_move_last - Move device to end of the PM core's list of devices.
 187  * @dev: Device to move in dpm_list.
 188  */
 189 void device_pm_move_last(struct device *dev)
 190 {
 191         pr_debug("PM: Moving %s:%s to end of list\n",
 192                  dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 193         list_move_tail(&dev->power.entry, &dpm_list);
 194 }
 195
 196 static ktime_t initcall_debug_start(struct device *dev)
 197 {
 198         ktime_t calltime = 0;
 199
 200         if (pm_print_times_enabled) {
 201                 pr_info("calling  %s+ @ %i, parent: %s\n",
 202                         dev_name(dev), task_pid_nr(current),
 203                         dev->parent ? dev_name(dev->parent) : "none");
 204                 calltime = ktime_get();
 205         }
 206
 207         return calltime;
 208 }
 209
 210 static void initcall_debug_report(struct device *dev, ktime_t calltime,
 211                                   int error, pm_message_t state,
 212                                   const char *info)
 213 {
 214         ktime_t rettime;
 215         s64 nsecs;
 216
 217         rettime = ktime_get();
 218         nsecs = (s64) ktime_to_ns(ktime_sub(rettime, calltime));
 219
 220         if (pm_print_times_enabled) {
 221                 pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev),
 222                         error, (unsigned long long)nsecs >> 10);
 223         }
 224 }
 225
 226 /**
 227  * dpm_wait - Wait for a PM operation to complete.
 228  * @dev: Device to wait for.
 229  * @async: If unset, wait only if the device's power.async_suspend flag is set.
 230  */
 231 static void dpm_wait(struct device *dev, bool async)
 232 {
 233         if (!dev)
 234                 return;
 235
 236         if (async || (pm_async_enabled && dev->power.async_suspend))
 237                 wait_for_completion(&dev->power.completion);
 238 }
 239
 240 static int dpm_wait_fn(struct device *dev, void *async_ptr)
 241 {
 242         dpm_wait(dev, *((bool *)async_ptr));
 243         return 0;
 244 }
 245
 246 static void dpm_wait_for_children(struct device *dev, bool async)
 247 {
 248        device_for_each_child(dev, &async, dpm_wait_fn);
 249 }
 250
 251 static void dpm_wait_for_suppliers(struct device *dev, bool async)
 252 {
 253         struct device_link *link;
 254         int idx;
 255
 256         idx = device_links_read_lock();
 257
 258         /*
 259          * If the supplier goes away right after we've checked the link to it,
 260          * we'll wait for its completion to change the state, but that's fine,
 261          * because the only things that will block as a result are the SRCU
 262          * callbacks freeing the link objects for the links in the list we're
 263          * walking.
 264          */
 265         list_for_each_entry_rcu(link, &dev->links.suppliers, c_node)
 266                 if (READ_ONCE(link->status) != DL_STATE_DORMANT)
 267                         dpm_wait(link->supplier, async);
 268
 269         device_links_read_unlock(idx);
 270 }
 271
 272 static void dpm_wait_for_superior(struct device *dev, bool async)
 273 {
 274         dpm_wait(dev->parent, async);
 275         dpm_wait_for_suppliers(dev, async);
 276 }
 277
 278 static void dpm_wait_for_consumers(struct device *dev, bool async)
 279 {
 280         struct device_link *link;
 281         int idx;
 282
 283         idx = device_links_read_lock();
 284
 285         /*
 286          * The status of a device link can only be changed from "dormant" by a
 287          * probe, but that cannot happen during system suspend/resume.  In
 288          * theory it can change to "dormant" at that time, but then it is
 289          * reasonable to wait for the target device anyway (eg. if it goes
 290          * away, it's better to wait for it to go away completely and then
 291          * continue instead of trying to continue in parallel with its
 292          * unregistration).
 293          */
 294         list_for_each_entry_rcu(link, &dev->links.consumers, s_node)
 295                 if (READ_ONCE(link->status) != DL_STATE_DORMANT)
 296                         dpm_wait(link->consumer, async);
 297
 298         device_links_read_unlock(idx);
 299 }
 300
 301 static void dpm_wait_for_subordinate(struct device *dev, bool async)
 302 {
 303         dpm_wait_for_children(dev, async);
 304         dpm_wait_for_consumers(dev, async);
 305 }
 306
 307 /**
 308  * pm_op - Return the PM operation appropriate for given PM event.
 309  * @ops: PM operations to choose from.
 310  * @state: PM transition of the system being carried out.
 311  */
 312 static pm_callback_t pm_op(const struct dev_pm_ops *ops, pm_message_t state)
 313 {
 314         switch (state.event) {
 315 #ifdef CONFIG_SUSPEND
 316         case PM_EVENT_SUSPEND:
 317                 return ops->suspend;
 318         case PM_EVENT_RESUME:
 319                 return ops->resume;
 320 #endif /* CONFIG_SUSPEND */
 321 #ifdef CONFIG_HIBERNATE_CALLBACKS
 322         case PM_EVENT_FREEZE:
 323         case PM_EVENT_QUIESCE:
 324                 return ops->freeze;
 325         case PM_EVENT_HIBERNATE:
 326                 return ops->poweroff;
 327         case PM_EVENT_THAW:
 328         case PM_EVENT_RECOVER:
 329                 return ops->thaw;
 330                 break;
 331         case PM_EVENT_RESTORE:
 332                 return ops->restore;
 333 #endif /* CONFIG_HIBERNATE_CALLBACKS */
 334         }
 335
 336         return NULL;
 337 }
 338
 339 /**
 340  * pm_late_early_op - Return the PM operation appropriate for given PM event.
 341  * @ops: PM operations to choose from.
 342  * @state: PM transition of the system being carried out.
 343  *
 344  * Runtime PM is disabled for @dev while this function is being executed.
 345  */
 346 static pm_callback_t pm_late_early_op(const struct dev_pm_ops *ops,
 347                                       pm_message_t state)
 348 {
 349         switch (state.event) {
 350 #ifdef CONFIG_SUSPEND
 351         case PM_EVENT_SUSPEND:
 352                 return ops->suspend_late;
 353         case PM_EVENT_RESUME:
 354                 return ops->resume_early;
 355 #endif /* CONFIG_SUSPEND */
 356 #ifdef CONFIG_HIBERNATE_CALLBACKS
 357         case PM_EVENT_FREEZE:
 358         case PM_EVENT_QUIESCE:
 359                 return ops->freeze_late;
 360         case PM_EVENT_HIBERNATE:
 361                 return ops->poweroff_late;
 362         case PM_EVENT_THAW:
 363         case PM_EVENT_RECOVER:
 364                 return ops->thaw_early;
 365         case PM_EVENT_RESTORE:
 366                 return ops->restore_early;
 367 #endif /* CONFIG_HIBERNATE_CALLBACKS */
 368         }
 369
 370         return NULL;
 371 }
 372
 373 /**
 374  * pm_noirq_op - Return the PM operation appropriate for given PM event.
 375  * @ops: PM operations to choose from.
 376  * @state: PM transition of the system being carried out.
 377  *
 378  * The driver of @dev will not receive interrupts while this function is being
 379  * executed.
 380  */
 381 static pm_callback_t pm_noirq_op(const struct dev_pm_ops *ops, pm_message_t state)
 382 {
 383         switch (state.event) {
 384 #ifdef CONFIG_SUSPEND
 385         case PM_EVENT_SUSPEND:
 386                 return ops->suspend_noirq;
 387         case PM_EVENT_RESUME:
 388                 return ops->resume_noirq;
 389 #endif /* CONFIG_SUSPEND */
 390 #ifdef CONFIG_HIBERNATE_CALLBACKS
 391         case PM_EVENT_FREEZE:
 392         case PM_EVENT_QUIESCE:
 393                 return ops->freeze_noirq;
 394         case PM_EVENT_HIBERNATE:
 395                 return ops->poweroff_noirq;
 396         case PM_EVENT_THAW:
 397         case PM_EVENT_RECOVER:
 398                 return ops->thaw_noirq;
 399         case PM_EVENT_RESTORE:
 400                 return ops->restore_noirq;
 401 #endif /* CONFIG_HIBERNATE_CALLBACKS */
 402         }
 403
 404         return NULL;
 405 }
 406
 407 static void pm_dev_dbg(struct device *dev, pm_message_t state, const char *info)
 408 {
 409         dev_dbg(dev, "%s%s%s\n", info, pm_verb(state.event),
 410                 ((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
 411                 ", may wakeup" : "");
 412 }
 413
 414 static void pm_dev_err(struct device *dev, pm_message_t state, const char *info,
 415                         int error)
 416 {
 417         printk(KERN_ERR "PM: Device %s failed to %s%s: error %d\n",
 418                 dev_name(dev), pm_verb(state.event), info, error);
 419 }
 420
 421 static void dpm_show_time(ktime_t starttime, pm_message_t state, int error,
 422                           const char *info)
 423 {
 424         ktime_t calltime;
 425         u64 usecs64;
 426         int usecs;
 427
 428         calltime = ktime_get();
 429         usecs64 = ktime_to_ns(ktime_sub(calltime, starttime));
 430         do_div(usecs64, NSEC_PER_USEC);
 431         usecs = usecs64;
 432         if (usecs == 0)
 433                 usecs = 1;
 434
 435         pm_pr_dbg("%s%s%s of devices %s after %ld.%03ld msecs\n",
 436                   info ?: "", info ? " " : "", pm_verb(state.event),
 437                   error ? "aborted" : "complete",
 438                   usecs / USEC_PER_MSEC, usecs % USEC_PER_MSEC);
 439 }
 440
 441 static int dpm_run_callback(pm_callback_t cb, struct device *dev,
 442                             pm_message_t state, const char *info)
 443 {
 444         ktime_t calltime;
 445         int error;
 446
 447         if (!cb)
 448                 return 0;
 449
 450         calltime = initcall_debug_start(dev);
 451
 452         pm_dev_dbg(dev, state, info);
 453         trace_device_pm_callback_start(dev, info, state.event);
 454         error = cb(dev);
 455         trace_device_pm_callback_end(dev, error);
 456         suspend_report_result(cb, error);
 457
 458         initcall_debug_report(dev, calltime, error, state, info);
 459
 460         return error;
 461 }
 462
 463 #ifdef CONFIG_DPM_WATCHDOG
 464 struct dpm_watchdog {
 465         struct device           *dev;
 466         struct task_struct      *tsk;
 467         struct timer_list       timer;
 468 };
 469
 470 #define DECLARE_DPM_WATCHDOG_ON_STACK(wd) \
 471         struct dpm_watchdog wd
 472
 473 /**
 474  * dpm_watchdog_handler - Driver suspend / resume watchdog handler.
 475  * @data: Watchdog object address.
 476  *
 477  * Called when a driver has timed out suspending or resuming.
 478  * There's not much we can do here to recover so panic() to
 479  * capture a crash-dump in pstore.
 480  */
 481 static void dpm_watchdog_handler(unsigned long data)
 482 {
 483         struct dpm_watchdog *wd = (void *)data;
 484
 485         dev_emerg(wd->dev, "**** DPM device timeout ****\n");
 486         show_stack(wd->tsk, NULL);
 487         panic("%s %s: unrecoverable failure\n",
 488                 dev_driver_string(wd->dev), dev_name(wd->dev));
 489 }
 490
 491 /**
 492  * dpm_watchdog_set - Enable pm watchdog for given device.
 493  * @wd: Watchdog. Must be allocated on the stack.
 494  * @dev: Device to handle.
 495  */
 496 static void dpm_watchdog_set(struct dpm_watchdog *wd, struct device *dev)
 497 {
 498         struct timer_list *timer = &wd->timer;
 499
 500         wd->dev = dev;
 501         wd->tsk = current;
 502
 503         init_timer_on_stack(timer);
 504         /* use same timeout value for both suspend and resume */
 505         timer->expires = jiffies + HZ * CONFIG_DPM_WATCHDOG_TIMEOUT;
 506         timer->function = dpm_watchdog_handler;
 507         timer->data = (unsigned long)wd;
 508         add_timer(timer);
 509 }
 510
 511 /**
 512  * dpm_watchdog_clear - Disable suspend/resume watchdog.
 513  * @wd: Watchdog to disable.
 514  */
 515 static void dpm_watchdog_clear(struct dpm_watchdog *wd)
 516 {
 517         struct timer_list *timer = &wd->timer;
 518
 519         del_timer_sync(timer);
 520         destroy_timer_on_stack(timer);
 521 }
 522 #else
 523 #define DECLARE_DPM_WATCHDOG_ON_STACK(wd)
 524 #define dpm_watchdog_set(x, y)
 525 #define dpm_watchdog_clear(x)
 526 #endif
 527
 528 /*------------------------- Resume routines -------------------------*/
 529
 530 /**
 531  * device_resume_noirq - Execute an "early resume" callback for given device.
 532  * @dev: Device to handle.
 533  * @state: PM transition of the system being carried out.
 534  * @async: If true, the device is being resumed asynchronously.
 535  *
 536  * The driver of @dev will not receive interrupts while this function is being
 537  * executed.
 538  */
 539 static int device_resume_noirq(struct device *dev, pm_message_t state, bool async)
 540 {
 541         pm_callback_t callback = NULL;
 542         const char *info = NULL;
 543         int error = 0;
 544
 545         TRACE_DEVICE(dev);
 546         TRACE_RESUME(0);
 547
 548         if (dev->power.syscore || dev->power.direct_complete)
 549                 goto Out;
 550
 551         if (!dev->power.is_noirq_suspended)
 552                 goto Out;
 553
 554         dpm_wait_for_superior(dev, async);
 555
 556         if (dev->pm_domain) {
 557                 info = "noirq power domain ";
 558                 callback = pm_noirq_op(&dev->pm_domain->ops, state);
 559         } else if (dev->type && dev->type->pm) {
 560                 info = "noirq type ";
 561                 callback = pm_noirq_op(dev->type->pm, state);
 562         } else if (dev->class && dev->class->pm) {
 563                 info = "noirq class ";
 564                 callback = pm_noirq_op(dev->class->pm, state);
 565         } else if (dev->bus && dev->bus->pm) {
 566                 info = "noirq bus ";
 567                 callback = pm_noirq_op(dev->bus->pm, state);
 568         }
 569
 570         if (!callback && dev->driver && dev->driver->pm) {
 571                 info = "noirq driver ";
 572                 callback = pm_noirq_op(dev->driver->pm, state);
 573         }
 574
 575         error = dpm_run_callback(callback, dev, state, info);
 576         dev->power.is_noirq_suspended = false;
 577
 578  Out:
 579         complete_all(&dev->power.completion);
 580         TRACE_RESUME(error);
 581         return error;
 582 }
 583
 584 static bool is_async(struct device *dev)
 585 {
 586         return dev->power.async_suspend && pm_async_enabled
 587                 && !pm_trace_is_enabled();
 588 }
 589
 590 static void async_resume_noirq(void *data, async_cookie_t cookie)
 591 {
 592         struct device *dev = (struct device *)data;
 593         int error;
 594
 595         error = device_resume_noirq(dev, pm_transition, true);
 596         if (error)
 597                 pm_dev_err(dev, pm_transition, " async", error);
 598
 599         put_device(dev);
 600 }
 601
 602 void dpm_noirq_resume_devices(pm_message_t state)
 603 {
 604         struct device *dev;
 605         ktime_t starttime = ktime_get();
 606
 607         trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, true);
 608         mutex_lock(&dpm_list_mtx);
 609         pm_transition = state;
 610
 611         /*
 612          * Advanced the async threads upfront,
 613          * in case the starting of async threads is
 614          * delayed by non-async resuming devices.
 615          */
 616         list_for_each_entry(dev, &dpm_noirq_list, power.entry) {
 617                 reinit_completion(&dev->power.completion);
 618                 if (is_async(dev)) {
 619                         get_device(dev);
 620                         async_schedule(async_resume_noirq, dev);
 621                 }
 622         }
 623
 624         while (!list_empty(&dpm_noirq_list)) {
 625                 dev = to_device(dpm_noirq_list.next);
 626                 get_device(dev);
 627                 list_move_tail(&dev->power.entry, &dpm_late_early_list);
 628                 mutex_unlock(&dpm_list_mtx);
 629
 630                 if (!is_async(dev)) {
 631                         int error;
 632
 633                         error = device_resume_noirq(dev, state, false);
 634                         if (error) {
 635                                 suspend_stats.failed_resume_noirq++;
 636                                 dpm_save_failed_step(SUSPEND_RESUME_NOIRQ);
 637                                 dpm_save_failed_dev(dev_name(dev));
 638                                 pm_dev_err(dev, state, " noirq", error);
 639                         }
 640                 }
 641
 642                 mutex_lock(&dpm_list_mtx);
 643                 put_device(dev);
 644         }
 645         mutex_unlock(&dpm_list_mtx);
 646         async_synchronize_full();
 647         dpm_show_time(starttime, state, 0, "noirq");
 648         trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, false);
 649 }
 650
 651 void dpm_noirq_end(void)
 652 {
 653         resume_device_irqs();
 654         device_wakeup_disarm_wake_irqs();
 655         cpuidle_resume();
 656 }
 657
 658 /**
 659  * dpm_resume_noirq - Execute "noirq resume" callbacks for all devices.
 660  * @state: PM transition of the system being carried out.
 661  *
 662  * Invoke the "noirq" resume callbacks for all devices in dpm_noirq_list and
 663  * allow device drivers' interrupt handlers to be called.
 664  */
 665 void dpm_resume_noirq(pm_message_t state)
 666 {
 667         dpm_noirq_resume_devices(state);
 668         dpm_noirq_end();
 669 }
 670
 671 /**
 672  * device_resume_early - Execute an "early resume" callback for given device.
 673  * @dev: Device to handle.
 674  * @state: PM transition of the system being carried out.
 675  * @async: If true, the device is being resumed asynchronously.
 676  *
 677  * Runtime PM is disabled for @dev while this function is being executed.
 678  */
 679 static int device_resume_early(struct device *dev, pm_message_t state, bool async)
 680 {
 681         pm_callback_t callback = NULL;
 682         const char *info = NULL;
 683         int error = 0;
 684
 685         TRACE_DEVICE(dev);
 686         TRACE_RESUME(0);
 687
 688         if (dev->power.syscore || dev->power.direct_complete)
 689                 goto Out;
 690
 691         if (!dev->power.is_late_suspended)
 692                 goto Out;
 693
 694         dpm_wait_for_superior(dev, async);
 695
 696         if (dev->pm_domain) {
 697                 info = "early power domain ";
 698                 callback = pm_late_early_op(&dev->pm_domain->ops, state);
 699         } else if (dev->type && dev->type->pm) {
 700                 info = "early type ";
 701                 callback = pm_late_early_op(dev->type->pm, state);
 702         } else if (dev->class && dev->class->pm) {
 703                 info = "early class ";
 704                 callback = pm_late_early_op(dev->class->pm, state);
 705         } else if (dev->bus && dev->bus->pm) {
 706                 info = "early bus ";
 707                 callback = pm_late_early_op(dev->bus->pm, state);
 708         }
 709
 710         if (!callback && dev->driver && dev->driver->pm) {
 711                 info = "early driver ";
 712                 callback = pm_late_early_op(dev->driver->pm, state);
 713         }
 714
 715         error = dpm_run_callback(callback, dev, state, info);
 716         dev->power.is_late_suspended = false;
 717
 718  Out:
 719         TRACE_RESUME(error);
 720
 721         pm_runtime_enable(dev);
 722         complete_all(&dev->power.completion);
 723         return error;
 724 }
 725
 726 static void async_resume_early(void *data, async_cookie_t cookie)
 727 {
 728         struct device *dev = (struct device *)data;
 729         int error;
 730
 731         error = device_resume_early(dev, pm_transition, true);
 732         if (error)
 733                 pm_dev_err(dev, pm_transition, " async", error);
 734
 735         put_device(dev);
 736 }
 737
 738 /**
 739  * dpm_resume_early - Execute "early resume" callbacks for all devices.
 740  * @state: PM transition of the system being carried out.
 741  */
 742 void dpm_resume_early(pm_message_t state)
 743 {
 744         struct device *dev;
 745         ktime_t starttime = ktime_get();
 746
 747         trace_suspend_resume(TPS("dpm_resume_early"), state.event, true);
 748         mutex_lock(&dpm_list_mtx);
 749         pm_transition = state;
 750
 751         /*
 752          * Advanced the async threads upfront,
 753          * in case the starting of async threads is
 754          * delayed by non-async resuming devices.
 755          */
 756         list_for_each_entry(dev, &dpm_late_early_list, power.entry) {
 757                 reinit_completion(&dev->power.completion);
 758                 if (is_async(dev)) {
 759                         get_device(dev);
 760                         async_schedule(async_resume_early, dev);
 761                 }
 762         }
 763
 764         while (!list_empty(&dpm_late_early_list)) {
 765                 dev = to_device(dpm_late_early_list.next);
 766                 get_device(dev);
 767                 list_move_tail(&dev->power.entry, &dpm_suspended_list);
 768                 mutex_unlock(&dpm_list_mtx);
 769
 770                 if (!is_async(dev)) {
 771                         int error;
 772
 773                         error = device_resume_early(dev, state, false);
 774                         if (error) {
 775                                 suspend_stats.failed_resume_early++;
 776                                 dpm_save_failed_step(SUSPEND_RESUME_EARLY);
 777                                 dpm_save_failed_dev(dev_name(dev));
 778                                 pm_dev_err(dev, state, " early", error);
 779                         }
 780                 }
 781                 mutex_lock(&dpm_list_mtx);
 782                 put_device(dev);
 783         }
 784         mutex_unlock(&dpm_list_mtx);
 785         async_synchronize_full();
 786         dpm_show_time(starttime, state, 0, "early");
 787         trace_suspend_resume(TPS("dpm_resume_early"), state.event, false);
 788 }
 789
 790 /**
 791  * dpm_resume_start - Execute "noirq" and "early" device callbacks.
 792  * @state: PM transition of the system being carried out.
 793  */
 794 void dpm_resume_start(pm_message_t state)
 795 {
 796         dpm_resume_noirq(state);
 797         dpm_resume_early(state);
 798 }
 799 EXPORT_SYMBOL_GPL(dpm_resume_start);
 800
 801 /**
 802  * device_resume - Execute "resume" callbacks for given device.
 803  * @dev: Device to handle.
 804  * @state: PM transition of the system being carried out.
 805  * @async: If true, the device is being resumed asynchronously.
 806  */
 807 static int device_resume(struct device *dev, pm_message_t state, bool async)
 808 {
 809         pm_callback_t callback = NULL;
 810         const char *info = NULL;
 811         int error = 0;
 812         DECLARE_DPM_WATCHDOG_ON_STACK(wd);
 813
 814         TRACE_DEVICE(dev);
 815         TRACE_RESUME(0);
 816
 817         if (dev->power.syscore)
 818                 goto Complete;
 819
 820         if (dev->power.direct_complete) {
 821                 /* Match the pm_runtime_disable() in __device_suspend(). */
 822                 pm_runtime_enable(dev);
 823                 goto Complete;
 824         }
 825
 826         dpm_wait_for_superior(dev, async);
 827         dpm_watchdog_set(&wd, dev);
 828         device_lock(dev);
 829
 830         /*
 831          * This is a fib.  But we'll allow new children to be added below
 832          * a resumed device, even if the device hasn't been completed yet.
 833          */
 834         dev->power.is_prepared = false;
 835
 836         if (!dev->power.is_suspended)
 837                 goto Unlock;
 838
 839         if (dev->pm_domain) {
 840                 info = "power domain ";
 841                 callback = pm_op(&dev->pm_domain->ops, state);
 842                 goto Driver;
 843         }
 844
 845         if (dev->type && dev->type->pm) {
 846                 info = "type ";
 847                 callback = pm_op(dev->type->pm, state);
 848                 goto Driver;
 849         }
 850
 851         if (dev->class) {
 852                 if (dev->class->pm) {
 853                         info = "class ";
 854                         callback = pm_op(dev->class->pm, state);
 855                         goto Driver;
 856                 } else if (dev->class->resume) {
 857                         info = "legacy class ";
 858                         callback = dev->class->resume;
 859                         goto End;
 860                 }
 861         }
 862
 863         if (dev->bus) {
 864                 if (dev->bus->pm) {
 865                         info = "bus ";
 866                         callback = pm_op(dev->bus->pm, state);
 867                 } else if (dev->bus->resume) {
 868                         info = "legacy bus ";
 869                         callback = dev->bus->resume;
 870                         goto End;
 871                 }
 872         }
 873
 874  Driver:
 875         if (!callback && dev->driver && dev->driver->pm) {
 876                 info = "driver ";
 877                 callback = pm_op(dev->driver->pm, state);
 878         }
 879
 880  End:
 881         error = dpm_run_callback(callback, dev, state, info);
 882         dev->power.is_suspended = false;
 883
 884  Unlock:
 885         device_unlock(dev);
 886         dpm_watchdog_clear(&wd);
 887
 888  Complete:
 889         complete_all(&dev->power.completion);
 890
 891         TRACE_RESUME(error);
 892
 893         return error;
 894 }
 895
 896 static void async_resume(void *data, async_cookie_t cookie)
 897 {
 898         struct device *dev = (struct device *)data;
 899         int error;
 900
 901         error = device_resume(dev, pm_transition, true);
 902         if (error)
 903                 pm_dev_err(dev, pm_transition, " async", error);
 904         put_device(dev);
 905 }
 906
 907 /**
 908  * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
 909  * @state: PM transition of the system being carried out.
 910  *
 911  * Execute the appropriate "resume" callback for all devices whose status
 912  * indicates that they are suspended.
 913  */
 914 void dpm_resume(pm_message_t state)
 915 {
 916         struct device *dev;
 917         ktime_t starttime = ktime_get();
 918
 919         trace_suspend_resume(TPS("dpm_resume"), state.event, true);
 920         might_sleep();
 921
 922         mutex_lock(&dpm_list_mtx);
 923         pm_transition = state;
 924         async_error = 0;
 925
 926         list_for_each_entry(dev, &dpm_suspended_list, power.entry) {
 927                 reinit_completion(&dev->power.completion);
 928                 if (is_async(dev)) {
 929                         get_device(dev);
 930                         async_schedule(async_resume, dev);
 931                 }
 932         }
 933
 934         while (!list_empty(&dpm_suspended_list)) {
 935                 dev = to_device(dpm_suspended_list.next);
 936                 get_device(dev);
 937                 if (!is_async(dev)) {
 938                         int error;
 939
 940                         mutex_unlock(&dpm_list_mtx);
 941
 942                         error = device_resume(dev, state, false);
 943                         if (error) {
 944                                 suspend_stats.failed_resume++;
 945                                 dpm_save_failed_step(SUSPEND_RESUME);
 946                                 dpm_save_failed_dev(dev_name(dev));
 947                                 pm_dev_err(dev, state, "", error);
 948                         }
 949
 950                         mutex_lock(&dpm_list_mtx);
 951                 }
 952                 if (!list_empty(&dev->power.entry))
 953                         list_move_tail(&dev->power.entry, &dpm_prepared_list);
 954                 put_device(dev);
 955         }
 956         mutex_unlock(&dpm_list_mtx);
 957         async_synchronize_full();
 958         dpm_show_time(starttime, state, 0, NULL);
 959
 960         cpufreq_resume();
 961         trace_suspend_resume(TPS("dpm_resume"), state.event, false);
 962 }
 963
 964 /**
 965  * device_complete - Complete a PM transition for given device.
 966  * @dev: Device to handle.
 967  * @state: PM transition of the system being carried out.
 968  */
 969 static void device_complete(struct device *dev, pm_message_t state)
 970 {
 971         void (*callback)(struct device *) = NULL;
 972         const char *info = NULL;
 973
 974         if (dev->power.syscore)
 975                 return;
 976
 977         device_lock(dev);
 978
 979         if (dev->pm_domain) {
 980                 info = "completing power domain ";
 981                 callback = dev->pm_domain->ops.complete;
 982         } else if (dev->type && dev->type->pm) {
 983                 info = "completing type ";
 984                 callback = dev->type->pm->complete;
 985         } else if (dev->class && dev->class->pm) {
 986                 info = "completing class ";
 987                 callback = dev->class->pm->complete;
 988         } else if (dev->bus && dev->bus->pm) {
 989                 info = "completing bus ";
 990                 callback = dev->bus->pm->complete;
 991         }
 992
 993         if (!callback && dev->driver && dev->driver->pm) {
 994                 info = "completing driver ";
 995                 callback = dev->driver->pm->complete;
 996         }
 997
 998         if (callback) {
 999                 pm_dev_dbg(dev, state, info);
1000                 callback(dev);
1001         }
1002
1003         device_unlock(dev);
1004
1005         pm_runtime_put(dev);
1006 }
1007
1008 /**
1009  * dpm_complete - Complete a PM transition for all non-sysdev devices.
1010  * @state: PM transition of the system being carried out.
1011  *
1012  * Execute the ->complete() callbacks for all devices whose PM status is not
1013  * DPM_ON (this allows new devices to be registered).
1014  */
1015 void dpm_complete(pm_message_t state)
1016 {
1017         struct list_head list;
1018
1019         trace_suspend_resume(TPS("dpm_complete"), state.event, true);
1020         might_sleep();
1021
1022         INIT_LIST_HEAD(&list);
1023         mutex_lock(&dpm_list_mtx);
1024         while (!list_empty(&dpm_prepared_list)) {
1025                 struct device *dev = to_device(dpm_prepared_list.prev);
1026
1027                 get_device(dev);
1028                 dev->power.is_prepared = false;
1029                 list_move(&dev->power.entry, &list);
1030                 mutex_unlock(&dpm_list_mtx);
1031
1032                 trace_device_pm_callback_start(dev, "", state.event);
1033                 device_complete(dev, state);
1034                 trace_device_pm_callback_end(dev, 0);
1035
1036                 mutex_lock(&dpm_list_mtx);
1037                 put_device(dev);
1038         }
1039         list_splice(&list, &dpm_list);
1040         mutex_unlock(&dpm_list_mtx);
1041
1042         /* Allow device probing and trigger re-probing of deferred devices */
1043         device_unblock_probing();
1044         trace_suspend_resume(TPS("dpm_complete"), state.event, false);
1045 }
1046
1047 /**
1048  * dpm_resume_end - Execute "resume" callbacks and complete system transition.
1049  * @state: PM transition of the system being carried out.
1050  *
1051  * Execute "resume" callbacks for all devices and complete the PM transition of
1052  * the system.
1053  */
1054 void dpm_resume_end(pm_message_t state)
1055 {
1056         dpm_resume(state);
1057         dpm_complete(state);
1058 }
1059 EXPORT_SYMBOL_GPL(dpm_resume_end);
1060
1061
1062 /*------------------------- Suspend routines -------------------------*/
1063
1064 /**
1065  * resume_event - Return a "resume" message for given "suspend" sleep state.
1066  * @sleep_state: PM message representing a sleep state.
1067  *
1068  * Return a PM message representing the resume event corresponding to given
1069  * sleep state.
1070  */
1071 static pm_message_t resume_event(pm_message_t sleep_state)
1072 {
1073         switch (sleep_state.event) {
1074         case PM_EVENT_SUSPEND:
1075                 return PMSG_RESUME;
1076         case PM_EVENT_FREEZE:
1077         case PM_EVENT_QUIESCE:
1078                 return PMSG_RECOVER;
1079         case PM_EVENT_HIBERNATE:
1080                 return PMSG_RESTORE;
1081         }
1082         return PMSG_ON;
1083 }
1084
1085 /**
1086  * device_suspend_noirq - Execute a "late suspend" callback for given device.
1087  * @dev: Device to handle.
1088  * @state: PM transition of the system being carried out.
1089  * @async: If true, the device is being suspended asynchronously.
1090  *
1091  * The driver of @dev will not receive interrupts while this function is being
1092  * executed.
1093  */
1094 static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool async)
1095 {
1096         pm_callback_t callback = NULL;
1097         const char *info = NULL;
1098         int error = 0;
1099
1100         TRACE_DEVICE(dev);
1101         TRACE_SUSPEND(0);
1102
1103         dpm_wait_for_subordinate(dev, async);
1104
1105         if (async_error)
1106                 goto Complete;
1107
1108         if (pm_wakeup_pending()) {
1109                 async_error = -EBUSY;
1110                 goto Complete;
1111         }
1112
1113         if (dev->power.syscore || dev->power.direct_complete)
1114                 goto Complete;
1115
1116         if (dev->pm_domain) {
1117                 info = "noirq power domain ";
1118                 callback = pm_noirq_op(&dev->pm_domain->ops, state);
1119         } else if (dev->type && dev->type->pm) {
1120                 info = "noirq type ";
1121                 callback = pm_noirq_op(dev->type->pm, state);
1122         } else if (dev->class && dev->class->pm) {
1123                 info = "noirq class ";
1124                 callback = pm_noirq_op(dev->class->pm, state);
1125         } else if (dev->bus && dev->bus->pm) {
1126                 info = "noirq bus ";
1127                 callback = pm_noirq_op(dev->bus->pm, state);
1128         }
1129
1130         if (!callback && dev->driver && dev->driver->pm) {
1131                 info = "noirq driver ";
1132                 callback = pm_noirq_op(dev->driver->pm, state);
1133         }
1134
1135         error = dpm_run_callback(callback, dev, state, info);
1136         if (!error)
1137                 dev->power.is_noirq_suspended = true;
1138         else
1139                 async_error = error;
1140
1141 Complete:
1142         complete_all(&dev->power.completion);
1143         TRACE_SUSPEND(error);
1144         return error;
1145 }
1146
1147 static void async_suspend_noirq(void *data, async_cookie_t cookie)
1148 {
1149         struct device *dev = (struct device *)data;
1150         int error;
1151
1152         error = __device_suspend_noirq(dev, pm_transition, true);
1153         if (error) {
1154                 dpm_save_failed_dev(dev_name(dev));
1155                 pm_dev_err(dev, pm_transition, " async", error);
1156         }
1157
1158         put_device(dev);
1159 }
1160
1161 static int device_suspend_noirq(struct device *dev)
1162 {
1163         reinit_completion(&dev->power.completion);
1164
1165         if (is_async(dev)) {
1166                 get_device(dev);
1167                 async_schedule(async_suspend_noirq, dev);
1168                 return 0;
1169         }
1170         return __device_suspend_noirq(dev, pm_transition, false);
1171 }
1172
1173 void dpm_noirq_begin(void)
1174 {
1175         cpuidle_pause();
1176         device_wakeup_arm_wake_irqs();
1177         suspend_device_irqs();
1178 }
1179
1180 int dpm_noirq_suspend_devices(pm_message_t state)
1181 {
1182         ktime_t starttime = ktime_get();
1183         int error = 0;
1184
1185         trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, true);
1186         mutex_lock(&dpm_list_mtx);
1187         pm_transition = state;
1188         async_error = 0;
1189
1190         while (!list_empty(&dpm_late_early_list)) {
1191                 struct device *dev = to_device(dpm_late_early_list.prev);
1192
1193                 get_device(dev);
1194                 mutex_unlock(&dpm_list_mtx);
1195
1196                 error = device_suspend_noirq(dev);
1197
1198                 mutex_lock(&dpm_list_mtx);
1199                 if (error) {
1200                         pm_dev_err(dev, state, " noirq", error);
1201                         dpm_save_failed_dev(dev_name(dev));
1202                         put_device(dev);
1203                         break;
1204                 }
1205                 if (!list_empty(&dev->power.entry))
1206                         list_move(&dev->power.entry, &dpm_noirq_list);
1207                 put_device(dev);
1208
1209                 if (async_error)
1210                         break;
1211         }
1212         mutex_unlock(&dpm_list_mtx);
1213         async_synchronize_full();
1214         if (!error)
1215                 error = async_error;
1216
1217         if (error) {
1218                 suspend_stats.failed_suspend_noirq++;
1219                 dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ);
1220         }
1221         dpm_show_time(starttime, state, error, "noirq");
1222         trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, false);
1223         return error;
1224 }
1225
1226 /**
1227  * dpm_suspend_noirq - Execute "noirq suspend" callbacks for all devices.
1228  * @state: PM transition of the system being carried out.
1229  *
1230  * Prevent device drivers' interrupt handlers from being called and invoke
1231  * "noirq" suspend callbacks for all non-sysdev devices.
1232  */
1233 int dpm_suspend_noirq(pm_message_t state)
1234 {
1235         int ret;
1236
1237         dpm_noirq_begin();
1238         ret = dpm_noirq_suspend_devices(state);
1239         if (ret)
1240                 dpm_resume_noirq(resume_event(state));
1241
1242         return ret;
1243 }
1244
1245 /**
1246  * device_suspend_late - Execute a "late suspend" callback for given device.
1247  * @dev: Device to handle.
1248  * @state: PM transition of the system being carried out.
1249  * @async: If true, the device is being suspended asynchronously.
1250  *
1251  * Runtime PM is disabled for @dev while this function is being executed.
1252  */
1253 static int __device_suspend_late(struct device *dev, pm_message_t state, bool async)
1254 {
1255         pm_callback_t callback = NULL;
1256         const char *info = NULL;
1257         int error = 0;
1258
1259         TRACE_DEVICE(dev);
1260         TRACE_SUSPEND(0);
1261
1262         __pm_runtime_disable(dev, false);
1263
1264         dpm_wait_for_subordinate(dev, async);
1265
1266         if (async_error)
1267                 goto Complete;
1268
1269         if (pm_wakeup_pending()) {
1270                 async_error = -EBUSY;
1271                 goto Complete;
1272         }
1273
1274         if (dev->power.syscore || dev->power.direct_complete)
1275                 goto Complete;
1276
1277         if (dev->pm_domain) {
1278                 info = "late power domain ";
1279                 callback = pm_late_early_op(&dev->pm_domain->ops, state);
1280         } else if (dev->type && dev->type->pm) {
1281                 info = "late type ";
1282                 callback = pm_late_early_op(dev->type->pm, state);
1283         } else if (dev->class && dev->class->pm) {
1284                 info = "late class ";
1285                 callback = pm_late_early_op(dev->class->pm, state);
1286         } else if (dev->bus && dev->bus->pm) {
1287                 info = "late bus ";
1288                 callback = pm_late_early_op(dev->bus->pm, state);
1289         }
1290
1291         if (!callback && dev->driver && dev->driver->pm) {
1292                 info = "late driver ";
1293                 callback = pm_late_early_op(dev->driver->pm, state);
1294         }
1295
1296         error = dpm_run_callback(callback, dev, state, info);
1297         if (!error)
1298                 dev->power.is_late_suspended = true;
1299         else
1300                 async_error = error;
1301
1302 Complete:
1303         TRACE_SUSPEND(error);
1304         complete_all(&dev->power.completion);
1305         return error;
1306 }
1307
1308 static void async_suspend_late(void *data, async_cookie_t cookie)
1309 {
1310         struct device *dev = (struct device *)data;
1311         int error;
1312
1313         error = __device_suspend_late(dev, pm_transition, true);
1314         if (error) {
1315                 dpm_save_failed_dev(dev_name(dev));
1316                 pm_dev_err(dev, pm_transition, " async", error);
1317         }
1318         put_device(dev);
1319 }
1320
1321 static int device_suspend_late(struct device *dev)
1322 {
1323         reinit_completion(&dev->power.completion);
1324
1325         if (is_async(dev)) {
1326                 get_device(dev);
1327                 async_schedule(async_suspend_late, dev);
1328                 return 0;
1329         }
1330
1331         return __device_suspend_late(dev, pm_transition, false);
1332 }
1333
1334 /**
1335  * dpm_suspend_late - Execute "late suspend" callbacks for all devices.
1336  * @state: PM transition of the system being carried out.
1337  */
1338 int dpm_suspend_late(pm_message_t state)
1339 {
1340         ktime_t starttime = ktime_get();
1341         int error = 0;
1342
1343         trace_suspend_resume(TPS("dpm_suspend_late"), state.event, true);
1344         mutex_lock(&dpm_list_mtx);
1345         pm_transition = state;
1346         async_error = 0;
1347
1348         while (!list_empty(&dpm_suspended_list)) {
1349                 struct device *dev = to_device(dpm_suspended_list.prev);
1350
1351                 get_device(dev);
1352                 mutex_unlock(&dpm_list_mtx);
1353
1354                 error = device_suspend_late(dev);
1355
1356                 mutex_lock(&dpm_list_mtx);
1357                 if (!list_empty(&dev->power.entry))
1358                         list_move(&dev->power.entry, &dpm_late_early_list);
1359
1360                 if (error) {
1361                         pm_dev_err(dev, state, " late", error);
1362                         dpm_save_failed_dev(dev_name(dev));
1363                         put_device(dev);
1364                         break;
1365                 }
1366                 put_device(dev);
1367
1368                 if (async_error)
1369                         break;
1370         }
1371         mutex_unlock(&dpm_list_mtx);
1372         async_synchronize_full();
1373         if (!error)
1374                 error = async_error;
1375         if (error) {
1376                 suspend_stats.failed_suspend_late++;
1377                 dpm_save_failed_step(SUSPEND_SUSPEND_LATE);
1378                 dpm_resume_early(resume_event(state));
1379         }
1380         dpm_show_time(starttime, state, error, "late");
1381         trace_suspend_resume(TPS("dpm_suspend_late"), state.event, false);
1382         return error;
1383 }
1384
1385 /**
1386  * dpm_suspend_end - Execute "late" and "noirq" device suspend callbacks.
1387  * @state: PM transition of the system being carried out.
1388  */
1389 int dpm_suspend_end(pm_message_t state)
1390 {
1391         int error = dpm_suspend_late(state);
1392         if (error)
1393                 return error;
1394
1395         error = dpm_suspend_noirq(state);
1396         if (error) {
1397                 dpm_resume_early(resume_event(state));
1398                 return error;
1399         }
1400
1401         return 0;
1402 }
1403 EXPORT_SYMBOL_GPL(dpm_suspend_end);
1404
1405 /**
1406  * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
1407  * @dev: Device to suspend.
1408  * @state: PM transition of the system being carried out.
1409  * @cb: Suspend callback to execute.
1410  * @info: string description of caller.
1411  */
1412 static int legacy_suspend(struct device *dev, pm_message_t state,
1413                           int (*cb)(struct device *dev, pm_message_t state),
1414                           const char *info)
1415 {
1416         int error;
1417         ktime_t calltime;
1418
1419         calltime = initcall_debug_start(dev);
1420
1421         trace_device_pm_callback_start(dev, info, state.event);
1422         error = cb(dev, state);
1423         trace_device_pm_callback_end(dev, error);
1424         suspend_report_result(cb, error);
1425
1426         initcall_debug_report(dev, calltime, error, state, info);
1427
1428         return error;
1429 }
1430
1431 static void dpm_clear_suppliers_direct_complete(struct device *dev)
1432 {
1433         struct device_link *link;
1434         int idx;
1435
1436         idx = device_links_read_lock();
1437
1438         list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) {
1439                 spin_lock_irq(&link->supplier->power.lock);
1440                 link->supplier->power.direct_complete = false;
1441                 spin_unlock_irq(&link->supplier->power.lock);
1442         }
1443
1444         device_links_read_unlock(idx);
1445 }
1446
1447 /**
1448  * device_suspend - Execute "suspend" callbacks for given device.
1449  * @dev: Device to handle.
1450  * @state: PM transition of the system being carried out.
1451  * @async: If true, the device is being suspended asynchronously.
1452  */
1453 static int __device_suspend(struct device *dev, pm_message_t state, bool async)
1454 {
1455         pm_callback_t callback = NULL;
1456         const char *info = NULL;
1457         int error = 0;
1458         DECLARE_DPM_WATCHDOG_ON_STACK(wd);
1459
1460         TRACE_DEVICE(dev);
1461         TRACE_SUSPEND(0);
1462
1463         dpm_wait_for_subordinate(dev, async);
1464
1465         if (async_error)
1466                 goto Complete;
1467
1468         /*
1469          * If a device configured to wake up the system from sleep states
1470          * has been suspended at run time and there's a resume request pending
1471          * for it, this is equivalent to the device signaling wakeup, so the
1472          * system suspend operation should be aborted.
1473          */
1474         if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
1475                 pm_wakeup_event(dev, 0);
1476
1477         if (pm_wakeup_pending()) {
1478                 async_error = -EBUSY;
1479                 goto Complete;
1480         }
1481
1482         if (dev->power.syscore)
1483                 goto Complete;
1484
1485         if (dev->power.direct_complete) {
1486                 if (pm_runtime_status_suspended(dev)) {
1487                         pm_runtime_disable(dev);
1488                         if (pm_runtime_status_suspended(dev))
1489                                 goto Complete;
1490
1491                         pm_runtime_enable(dev);
1492                 }
1493                 dev->power.direct_complete = false;
1494         }
1495
1496         dpm_watchdog_set(&wd, dev);
1497         device_lock(dev);
1498
1499         if (dev->pm_domain) {
1500                 info = "power domain ";
1501                 callback = pm_op(&dev->pm_domain->ops, state);
1502                 goto Run;
1503         }
1504
1505         if (dev->type && dev->type->pm) {
1506                 info = "type ";
1507                 callback = pm_op(dev->type->pm, state);
1508                 goto Run;
1509         }
1510
1511         if (dev->class) {
1512                 if (dev->class->pm) {
1513                         info = "class ";
1514                         callback = pm_op(dev->class->pm, state);
1515                         goto Run;
1516                 } else if (dev->class->suspend) {
1517                         pm_dev_dbg(dev, state, "legacy class ");
1518                         error = legacy_suspend(dev, state, dev->class->suspend,
1519                                                 "legacy class ");
1520                         goto End;
1521                 }
1522         }
1523
1524         if (dev->bus) {
1525                 if (dev->bus->pm) {
1526                         info = "bus ";
1527                         callback = pm_op(dev->bus->pm, state);
1528                 } else if (dev->bus->suspend) {
1529                         pm_dev_dbg(dev, state, "legacy bus ");
1530                         error = legacy_suspend(dev, state, dev->bus->suspend,
1531                                                 "legacy bus ");
1532                         goto End;
1533                 }
1534         }
1535
1536  Run:
1537         if (!callback && dev->driver && dev->driver->pm) {
1538                 info = "driver ";
1539                 callback = pm_op(dev->driver->pm, state);
1540         }
1541
1542         error = dpm_run_callback(callback, dev, state, info);
1543
1544  End:
1545         if (!error) {
1546                 struct device *parent = dev->parent;
1547
1548                 dev->power.is_suspended = true;
1549                 if (parent) {
1550                         spin_lock_irq(&parent->power.lock);
1551
1552                         dev->parent->power.direct_complete = false;
1553                         if (dev->power.wakeup_path
1554                             && !dev->parent->power.ignore_children)
1555                                 dev->parent->power.wakeup_path = true;
1556
1557                         spin_unlock_irq(&parent->power.lock);
1558                 }
1559                 dpm_clear_suppliers_direct_complete(dev);
1560         }
1561
1562         device_unlock(dev);
1563         dpm_watchdog_clear(&wd);
1564
1565  Complete:
1566         if (error)
1567                 async_error = error;
1568
1569         complete_all(&dev->power.completion);
1570         TRACE_SUSPEND(error);
1571         return error;
1572 }
1573
1574 static void async_suspend(void *data, async_cookie_t cookie)
1575 {
1576         struct device *dev = (struct device *)data;
1577         int error;
1578
1579         error = __device_suspend(dev, pm_transition, true);
1580         if (error) {
1581                 dpm_save_failed_dev(dev_name(dev));
1582                 pm_dev_err(dev, pm_transition, " async", error);
1583         }
1584
1585         put_device(dev);
1586 }
1587
1588 static int device_suspend(struct device *dev)
1589 {
1590         reinit_completion(&dev->power.completion);
1591
1592         if (is_async(dev)) {
1593                 get_device(dev);
1594                 async_schedule(async_suspend, dev);
1595                 return 0;
1596         }
1597
1598         return __device_suspend(dev, pm_transition, false);
1599 }
1600
1601 /**
1602  * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
1603  * @state: PM transition of the system being carried out.
1604  */
1605 int dpm_suspend(pm_message_t state)
1606 {
1607         ktime_t starttime = ktime_get();
1608         int error = 0;
1609
1610         trace_suspend_resume(TPS("dpm_suspend"), state.event, true);
1611         might_sleep();
1612
1613         cpufreq_suspend();
1614
1615         mutex_lock(&dpm_list_mtx);
1616         pm_transition = state;
1617         async_error = 0;
1618         while (!list_empty(&dpm_prepared_list)) {
1619                 struct device *dev = to_device(dpm_prepared_list.prev);
1620
1621                 get_device(dev);
1622                 mutex_unlock(&dpm_list_mtx);
1623
1624                 error = device_suspend(dev);
1625
1626                 mutex_lock(&dpm_list_mtx);
1627                 if (error) {
1628                         pm_dev_err(dev, state, "", error);
1629                         dpm_save_failed_dev(dev_name(dev));
1630                         put_device(dev);
1631                         break;
1632                 }
1633                 if (!list_empty(&dev->power.entry))
1634                         list_move(&dev->power.entry, &dpm_suspended_list);
1635                 put_device(dev);
1636                 if (async_error)
1637                         break;
1638         }
1639         mutex_unlock(&dpm_list_mtx);
1640         async_synchronize_full();
1641         if (!error)
1642                 error = async_error;
1643         if (error) {
1644                 suspend_stats.failed_suspend++;
1645                 dpm_save_failed_step(SUSPEND_SUSPEND);
1646         }
1647         dpm_show_time(starttime, state, error, NULL);
1648         trace_suspend_resume(TPS("dpm_suspend"), state.event, false);
1649         return error;
1650 }
1651
1652 /**
1653  * device_prepare - Prepare a device for system power transition.
1654  * @dev: Device to handle.
1655  * @state: PM transition of the system being carried out.
1656  *
1657  * Execute the ->prepare() callback(s) for given device.  No new children of the
1658  * device may be registered after this function has returned.
1659  */
1660 static int device_prepare(struct device *dev, pm_message_t state)
1661 {
1662         int (*callback)(struct device *) = NULL;
1663         int ret = 0;
1664
1665         if (dev->power.syscore)
1666                 return 0;
1667
1668         /*
1669          * If a device's parent goes into runtime suspend at the wrong time,
1670          * it won't be possible to resume the device.  To prevent this we
1671          * block runtime suspend here, during the prepare phase, and allow
1672          * it again during the complete phase.
1673          */
1674         pm_runtime_get_noresume(dev);
1675
1676         device_lock(dev);
1677
1678         dev->power.wakeup_path = device_may_wakeup(dev);
1679
1680         if (dev->power.no_pm_callbacks) {
1681                 ret = 1;        /* Let device go direct_complete */
1682                 goto unlock;
1683         }
1684
1685         if (dev->pm_domain)
1686                 callback = dev->pm_domain->ops.prepare;
1687         else if (dev->type && dev->type->pm)
1688                 callback = dev->type->pm->prepare;
1689         else if (dev->class && dev->class->pm)
1690                 callback = dev->class->pm->prepare;
1691         else if (dev->bus && dev->bus->pm)
1692                 callback = dev->bus->pm->prepare;
1693
1694         if (!callback && dev->driver && dev->driver->pm)
1695                 callback = dev->driver->pm->prepare;
1696
1697         if (callback)
1698                 ret = callback(dev);
1699
1700 unlock:
1701         device_unlock(dev);
1702
1703         if (ret < 0) {
1704                 suspend_report_result(callback, ret);
1705                 pm_runtime_put(dev);
1706                 return ret;
1707         }
1708         /*
1709          * A positive return value from ->prepare() means "this device appears
1710          * to be runtime-suspended and its state is fine, so if it really is
1711          * runtime-suspended, you can leave it in that state provided that you
1712          * will do the same thing with all of its descendants".  This only
1713          * applies to suspend transitions, however.
1714          */
1715         spin_lock_irq(&dev->power.lock);
1716         dev->power.direct_complete = ret > 0 && state.event == PM_EVENT_SUSPEND;
1717         spin_unlock_irq(&dev->power.lock);
1718         return 0;
1719 }
1720
1721 /**
1722  * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1723  * @state: PM transition of the system being carried out.
1724  *
1725  * Execute the ->prepare() callback(s) for all devices.
1726  */
1727 int dpm_prepare(pm_message_t state)
1728 {
1729         int error = 0;
1730
1731         trace_suspend_resume(TPS("dpm_prepare"), state.event, true);
1732         might_sleep();
1733
1734         /*
1735          * Give a chance for the known devices to complete their probes, before
1736          * disable probing of devices. This sync point is important at least
1737          * at boot time + hibernation restore.
1738          */
1739         wait_for_device_probe();
1740         /*
1741          * It is unsafe if probing of devices will happen during suspend or
1742          * hibernation and system behavior will be unpredictable in this case.
1743          * So, let's prohibit device's probing here and defer their probes
1744          * instead. The normal behavior will be restored in dpm_complete().
1745          */
1746         device_block_probing();
1747
1748         mutex_lock(&dpm_list_mtx);
1749         while (!list_empty(&dpm_list)) {
1750                 struct device *dev = to_device(dpm_list.next);
1751
1752                 get_device(dev);
1753                 mutex_unlock(&dpm_list_mtx);
1754
1755                 trace_device_pm_callback_start(dev, "", state.event);
1756                 error = device_prepare(dev, state);
1757                 trace_device_pm_callback_end(dev, error);
1758
1759                 mutex_lock(&dpm_list_mtx);
1760                 if (error) {
1761                         if (error == -EAGAIN) {
1762                                 put_device(dev);
1763                                 error = 0;
1764                                 continue;
1765                         }
1766                         printk(KERN_INFO "PM: Device %s not prepared "
1767                                 "for power transition: code %d\n",
1768                                 dev_name(dev), error);
1769                         put_device(dev);
1770                         break;
1771                 }
1772                 dev->power.is_prepared = true;
1773                 if (!list_empty(&dev->power.entry))
1774                         list_move_tail(&dev->power.entry, &dpm_prepared_list);
1775                 put_device(dev);
1776         }
1777         mutex_unlock(&dpm_list_mtx);
1778         trace_suspend_resume(TPS("dpm_prepare"), state.event, false);
1779         return error;
1780 }
1781
1782 /**
1783  * dpm_suspend_start - Prepare devices for PM transition and suspend them.
1784  * @state: PM transition of the system being carried out.
1785  *
1786  * Prepare all non-sysdev devices for system PM transition and execute "suspend"
1787  * callbacks for them.
1788  */
1789 int dpm_suspend_start(pm_message_t state)
1790 {
1791         int error;
1792
1793         error = dpm_prepare(state);
1794         if (error) {
1795                 suspend_stats.failed_prepare++;
1796                 dpm_save_failed_step(SUSPEND_PREPARE);
1797         } else
1798                 error = dpm_suspend(state);
1799         return error;
1800 }
1801 EXPORT_SYMBOL_GPL(dpm_suspend_start);
1802
1803 void __suspend_report_result(const char *function, void *fn, int ret)
1804 {
1805         if (ret)
1806                 printk(KERN_ERR "%s(): %pF returns %d\n", function, fn, ret);
1807 }
1808 EXPORT_SYMBOL_GPL(__suspend_report_result);
1809
1810 /**
1811  * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
1812  * @dev: Device to wait for.
1813  * @subordinate: Device that needs to wait for @dev.
1814  */
1815 int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
1816 {
1817         dpm_wait(dev, subordinate->power.async_suspend);
1818         return async_error;
1819 }
1820 EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);
1821
1822 /**
1823  * dpm_for_each_dev - device iterator.
1824  * @data: data for the callback.
1825  * @fn: function to be called for each device.
1826  *
1827  * Iterate over devices in dpm_list, and call @fn for each device,
1828  * passing it @data.
1829  */
1830 void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *))
1831 {
1832         struct device *dev;
1833
1834         if (!fn)
1835                 return;
1836
1837         device_pm_lock();
1838         list_for_each_entry(dev, &dpm_list, power.entry)
1839                 fn(dev, data);
1840         device_pm_unlock();
1841 }
1842 EXPORT_SYMBOL_GPL(dpm_for_each_dev);
1843
1844 static bool pm_ops_is_empty(const struct dev_pm_ops *ops)
1845 {
1846         if (!ops)
1847                 return true;
1848
1849         return !ops->prepare &&
1850                !ops->suspend &&
1851                !ops->suspend_late &&
1852                !ops->suspend_noirq &&
1853                !ops->resume_noirq &&
1854                !ops->resume_early &&
1855                !ops->resume &&
1856                !ops->complete;
1857 }
1858
1859 void device_pm_check_callbacks(struct device *dev)
1860 {
1861         spin_lock_irq(&dev->power.lock);
1862         dev->power.no_pm_callbacks =
1863                 (!dev->bus || pm_ops_is_empty(dev->bus->pm)) &&
1864                 (!dev->class || pm_ops_is_empty(dev->class->pm)) &&
1865                 (!dev->type || pm_ops_is_empty(dev->type->pm)) &&
1866                 (!dev->pm_domain || pm_ops_is_empty(&dev->pm_domain->ops)) &&
1867                 (!dev->driver || pm_ops_is_empty(dev->driver->pm));
1868         spin_unlock_irq(&dev->power.lock);
1869 }