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