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