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
  32 #include "../base.h"
  33 #include "power.h"
  34
  35 /*
  36  * The entries in the dpm_list list are in a depth first order, simply
  37  * because children are guaranteed to be discovered after parents, and
  38  * are inserted at the back of the list on discovery.
  39  *
  40  * Since device_pm_add() may be called with a device lock held,
  41  * we must never try to acquire a device lock while holding
  42  * dpm_list_mutex.
  43  */
  44
  45 LIST_HEAD(dpm_list);
  46 LIST_HEAD(dpm_prepared_list);
  47 LIST_HEAD(dpm_suspended_list);
  48 LIST_HEAD(dpm_noirq_list);
  49
  50 struct suspend_stats suspend_stats;
  51 static DEFINE_MUTEX(dpm_list_mtx);
  52 static pm_message_t pm_transition;
  53
  54 static int async_error;
  55
  56 /**
  57  * device_pm_init - Initialize the PM-related part of a device object.
  58  * @dev: Device object being initialized.
  59  */
  60 void device_pm_init(struct device *dev)
  61 {
  62         dev->power.is_prepared = false;
  63         dev->power.is_suspended = false;
  64         init_completion(&dev->power.completion);
  65         complete_all(&dev->power.completion);
  66         dev->power.wakeup = NULL;
  67         spin_lock_init(&dev->power.lock);
  68         pm_runtime_init(dev);
  69         INIT_LIST_HEAD(&dev->power.entry);
  70         dev->power.power_state = PMSG_INVALID;
  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 (initcall_debug) {
 167                 pr_info("calling  %s+ @ %i\n",
 168                                 dev_name(dev), task_pid_nr(current));
 169                 calltime = ktime_get();
 170         }
 171
 172         return calltime;
 173 }
 174
 175 static void initcall_debug_report(struct device *dev, ktime_t calltime,
 176                                   int error)
 177 {
 178         ktime_t delta, rettime;
 179
 180         if (initcall_debug) {
 181                 rettime = ktime_get();
 182                 delta = ktime_sub(rettime, calltime);
 183                 pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev),
 184                         error, (unsigned long long)ktime_to_ns(delta) >> 10);
 185         }
 186 }
 187
 188 /**
 189  * dpm_wait - Wait for a PM operation to complete.
 190  * @dev: Device to wait for.
 191  * @async: If unset, wait only if the device's power.async_suspend flag is set.
 192  */
 193 static void dpm_wait(struct device *dev, bool async)
 194 {
 195         if (!dev)
 196                 return;
 197
 198         if (async || (pm_async_enabled && dev->power.async_suspend))
 199                 wait_for_completion(&dev->power.completion);
 200 }
 201
 202 static int dpm_wait_fn(struct device *dev, void *async_ptr)
 203 {
 204         dpm_wait(dev, *((bool *)async_ptr));
 205         return 0;
 206 }
 207
 208 static void dpm_wait_for_children(struct device *dev, bool async)
 209 {
 210        device_for_each_child(dev, &async, dpm_wait_fn);
 211 }
 212
 213 /**
 214  * pm_op - Execute the PM operation appropriate for given PM event.
 215  * @dev: Device to handle.
 216  * @ops: PM operations to choose from.
 217  * @state: PM transition of the system being carried out.
 218  */
 219 static int pm_op(struct device *dev,
 220                  const struct dev_pm_ops *ops,
 221                  pm_message_t state)
 222 {
 223         int error = 0;
 224         ktime_t calltime;
 225
 226         calltime = initcall_debug_start(dev);
 227
 228         switch (state.event) {
 229 #ifdef CONFIG_SUSPEND
 230         case PM_EVENT_SUSPEND:
 231                 if (ops->suspend) {
 232                         error = ops->suspend(dev);
 233                         suspend_report_result(ops->suspend, error);
 234                 }
 235                 break;
 236         case PM_EVENT_RESUME:
 237                 if (ops->resume) {
 238                         error = ops->resume(dev);
 239                         suspend_report_result(ops->resume, error);
 240                 }
 241                 break;
 242 #endif /* CONFIG_SUSPEND */
 243 #ifdef CONFIG_HIBERNATE_CALLBACKS
 244         case PM_EVENT_FREEZE:
 245         case PM_EVENT_QUIESCE:
 246                 if (ops->freeze) {
 247                         error = ops->freeze(dev);
 248                         suspend_report_result(ops->freeze, error);
 249                 }
 250                 break;
 251         case PM_EVENT_HIBERNATE:
 252                 if (ops->poweroff) {
 253                         error = ops->poweroff(dev);
 254                         suspend_report_result(ops->poweroff, error);
 255                 }
 256                 break;
 257         case PM_EVENT_THAW:
 258         case PM_EVENT_RECOVER:
 259                 if (ops->thaw) {
 260                         error = ops->thaw(dev);
 261                         suspend_report_result(ops->thaw, error);
 262                 }
 263                 break;
 264         case PM_EVENT_RESTORE:
 265                 if (ops->restore) {
 266                         error = ops->restore(dev);
 267                         suspend_report_result(ops->restore, error);
 268                 }
 269                 break;
 270 #endif /* CONFIG_HIBERNATE_CALLBACKS */
 271         default:
 272                 error = -EINVAL;
 273         }
 274
 275         initcall_debug_report(dev, calltime, error);
 276
 277         return error;
 278 }
 279
 280 /**
 281  * pm_noirq_op - Execute the PM operation appropriate for given PM event.
 282  * @dev: Device to handle.
 283  * @ops: PM operations to choose from.
 284  * @state: PM transition of the system being carried out.
 285  *
 286  * The driver of @dev will not receive interrupts while this function is being
 287  * executed.
 288  */
 289 static int pm_noirq_op(struct device *dev,
 290                         const struct dev_pm_ops *ops,
 291                         pm_message_t state)
 292 {
 293         int error = 0;
 294         ktime_t calltime = ktime_set(0, 0), delta, rettime;
 295
 296         if (initcall_debug) {
 297                 pr_info("calling  %s+ @ %i, parent: %s\n",
 298                                 dev_name(dev), task_pid_nr(current),
 299                                 dev->parent ? dev_name(dev->parent) : "none");
 300                 calltime = ktime_get();
 301         }
 302
 303         switch (state.event) {
 304 #ifdef CONFIG_SUSPEND
 305         case PM_EVENT_SUSPEND:
 306                 if (ops->suspend_noirq) {
 307                         error = ops->suspend_noirq(dev);
 308                         suspend_report_result(ops->suspend_noirq, error);
 309                 }
 310                 break;
 311         case PM_EVENT_RESUME:
 312                 if (ops->resume_noirq) {
 313                         error = ops->resume_noirq(dev);
 314                         suspend_report_result(ops->resume_noirq, error);
 315                 }
 316                 break;
 317 #endif /* CONFIG_SUSPEND */
 318 #ifdef CONFIG_HIBERNATE_CALLBACKS
 319         case PM_EVENT_FREEZE:
 320         case PM_EVENT_QUIESCE:
 321                 if (ops->freeze_noirq) {
 322                         error = ops->freeze_noirq(dev);
 323                         suspend_report_result(ops->freeze_noirq, error);
 324                 }
 325                 break;
 326         case PM_EVENT_HIBERNATE:
 327                 if (ops->poweroff_noirq) {
 328                         error = ops->poweroff_noirq(dev);
 329                         suspend_report_result(ops->poweroff_noirq, error);
 330                 }
 331                 break;
 332         case PM_EVENT_THAW:
 333         case PM_EVENT_RECOVER:
 334                 if (ops->thaw_noirq) {
 335                         error = ops->thaw_noirq(dev);
 336                         suspend_report_result(ops->thaw_noirq, error);
 337                 }
 338                 break;
 339         case PM_EVENT_RESTORE:
 340                 if (ops->restore_noirq) {
 341                         error = ops->restore_noirq(dev);
 342                         suspend_report_result(ops->restore_noirq, error);
 343                 }
 344                 break;
 345 #endif /* CONFIG_HIBERNATE_CALLBACKS */
 346         default:
 347                 error = -EINVAL;
 348         }
 349
 350         if (initcall_debug) {
 351                 rettime = ktime_get();
 352                 delta = ktime_sub(rettime, calltime);
 353                 printk("initcall %s_i+ returned %d after %Ld usecs\n",
 354                         dev_name(dev), error,
 355                         (unsigned long long)ktime_to_ns(delta) >> 10);
 356         }
 357
 358         return error;
 359 }
 360
 361 static char *pm_verb(int event)
 362 {
 363         switch (event) {
 364         case PM_EVENT_SUSPEND:
 365                 return "suspend";
 366         case PM_EVENT_RESUME:
 367                 return "resume";
 368         case PM_EVENT_FREEZE:
 369                 return "freeze";
 370         case PM_EVENT_QUIESCE:
 371                 return "quiesce";
 372         case PM_EVENT_HIBERNATE:
 373                 return "hibernate";
 374         case PM_EVENT_THAW:
 375                 return "thaw";
 376         case PM_EVENT_RESTORE:
 377                 return "restore";
 378         case PM_EVENT_RECOVER:
 379                 return "recover";
 380         default:
 381                 return "(unknown PM event)";
 382         }
 383 }
 384
 385 static void pm_dev_dbg(struct device *dev, pm_message_t state, char *info)
 386 {
 387         dev_dbg(dev, "%s%s%s\n", info, pm_verb(state.event),
 388                 ((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
 389                 ", may wakeup" : "");
 390 }
 391
 392 static void pm_dev_err(struct device *dev, pm_message_t state, char *info,
 393                         int error)
 394 {
 395         printk(KERN_ERR "PM: Device %s failed to %s%s: error %d\n",
 396                 dev_name(dev), pm_verb(state.event), info, error);
 397 }
 398
 399 static void dpm_show_time(ktime_t starttime, pm_message_t state, char *info)
 400 {
 401         ktime_t calltime;
 402         u64 usecs64;
 403         int usecs;
 404
 405         calltime = ktime_get();
 406         usecs64 = ktime_to_ns(ktime_sub(calltime, starttime));
 407         do_div(usecs64, NSEC_PER_USEC);
 408         usecs = usecs64;
 409         if (usecs == 0)
 410                 usecs = 1;
 411         pr_info("PM: %s%s%s of devices complete after %ld.%03ld msecs\n",
 412                 info ?: "", info ? " " : "", pm_verb(state.event),
 413                 usecs / USEC_PER_MSEC, usecs % USEC_PER_MSEC);
 414 }
 415
 416 /*------------------------- Resume routines -------------------------*/
 417
 418 /**
 419  * device_resume_noirq - Execute an "early resume" callback for given device.
 420  * @dev: Device to handle.
 421  * @state: PM transition of the system being carried out.
 422  *
 423  * The driver of @dev will not receive interrupts while this function is being
 424  * executed.
 425  */
 426 static int device_resume_noirq(struct device *dev, pm_message_t state)
 427 {
 428         int error = 0;
 429
 430         TRACE_DEVICE(dev);
 431         TRACE_RESUME(0);
 432
 433         if (dev->pm_domain) {
 434                 pm_dev_dbg(dev, state, "EARLY power domain ");
 435                 error = pm_noirq_op(dev, &dev->pm_domain->ops, state);
 436         } else if (dev->type && dev->type->pm) {
 437                 pm_dev_dbg(dev, state, "EARLY type ");
 438                 error = pm_noirq_op(dev, dev->type->pm, state);
 439         } else if (dev->class && dev->class->pm) {
 440                 pm_dev_dbg(dev, state, "EARLY class ");
 441                 error = pm_noirq_op(dev, dev->class->pm, state);
 442         } else if (dev->bus && dev->bus->pm) {
 443                 pm_dev_dbg(dev, state, "EARLY ");
 444                 error = pm_noirq_op(dev, dev->bus->pm, state);
 445         }
 446
 447         TRACE_RESUME(error);
 448         return error;
 449 }
 450
 451 /**
 452  * dpm_resume_noirq - Execute "early resume" callbacks for non-sysdev devices.
 453  * @state: PM transition of the system being carried out.
 454  *
 455  * Call the "noirq" resume handlers for all devices marked as DPM_OFF_IRQ and
 456  * enable device drivers to receive interrupts.
 457  */
 458 void dpm_resume_noirq(pm_message_t state)
 459 {
 460         ktime_t starttime = ktime_get();
 461
 462         mutex_lock(&dpm_list_mtx);
 463         while (!list_empty(&dpm_noirq_list)) {
 464                 struct device *dev = to_device(dpm_noirq_list.next);
 465                 int error;
 466
 467                 get_device(dev);
 468                 list_move_tail(&dev->power.entry, &dpm_suspended_list);
 469                 mutex_unlock(&dpm_list_mtx);
 470
 471                 error = device_resume_noirq(dev, state);
 472                 if (error) {
 473                         suspend_stats.failed_resume_noirq++;
 474                         dpm_save_failed_step(SUSPEND_RESUME_NOIRQ);
 475                         dpm_save_failed_dev(dev_name(dev));
 476                         pm_dev_err(dev, state, " early", error);
 477                 }
 478
 479                 mutex_lock(&dpm_list_mtx);
 480                 put_device(dev);
 481         }
 482         mutex_unlock(&dpm_list_mtx);
 483         dpm_show_time(starttime, state, "early");
 484         resume_device_irqs();
 485 }
 486 EXPORT_SYMBOL_GPL(dpm_resume_noirq);
 487
 488 /**
 489  * legacy_resume - Execute a legacy (bus or class) resume callback for device.
 490  * @dev: Device to resume.
 491  * @cb: Resume callback to execute.
 492  */
 493 static int legacy_resume(struct device *dev, int (*cb)(struct device *dev))
 494 {
 495         int error;
 496         ktime_t calltime;
 497
 498         calltime = initcall_debug_start(dev);
 499
 500         error = cb(dev);
 501         suspend_report_result(cb, error);
 502
 503         initcall_debug_report(dev, calltime, error);
 504
 505         return error;
 506 }
 507
 508 /**
 509  * device_resume - Execute "resume" callbacks for given device.
 510  * @dev: Device to handle.
 511  * @state: PM transition of the system being carried out.
 512  * @async: If true, the device is being resumed asynchronously.
 513  */
 514 static int device_resume(struct device *dev, pm_message_t state, bool async)
 515 {
 516         int error = 0;
 517         bool put = false;
 518
 519         TRACE_DEVICE(dev);
 520         TRACE_RESUME(0);
 521
 522         dpm_wait(dev->parent, async);
 523         device_lock(dev);
 524
 525         /*
 526          * This is a fib.  But we'll allow new children to be added below
 527          * a resumed device, even if the device hasn't been completed yet.
 528          */
 529         dev->power.is_prepared = false;
 530
 531         if (!dev->power.is_suspended)
 532                 goto Unlock;
 533
 534         pm_runtime_enable(dev);
 535         put = true;
 536
 537         if (dev->pm_domain) {
 538                 pm_dev_dbg(dev, state, "power domain ");
 539                 error = pm_op(dev, &dev->pm_domain->ops, state);
 540                 goto End;
 541         }
 542
 543         if (dev->type && dev->type->pm) {
 544                 pm_dev_dbg(dev, state, "type ");
 545                 error = pm_op(dev, dev->type->pm, state);
 546                 goto End;
 547         }
 548
 549         if (dev->class) {
 550                 if (dev->class->pm) {
 551                         pm_dev_dbg(dev, state, "class ");
 552                         error = pm_op(dev, dev->class->pm, state);
 553                         goto End;
 554                 } else if (dev->class->resume) {
 555                         pm_dev_dbg(dev, state, "legacy class ");
 556                         error = legacy_resume(dev, dev->class->resume);
 557                         goto End;
 558                 }
 559         }
 560
 561         if (dev->bus) {
 562                 if (dev->bus->pm) {
 563                         pm_dev_dbg(dev, state, "");
 564                         error = pm_op(dev, dev->bus->pm, state);
 565                 } else if (dev->bus->resume) {
 566                         pm_dev_dbg(dev, state, "legacy ");
 567                         error = legacy_resume(dev, dev->bus->resume);
 568                 }
 569         }
 570
 571  End:
 572         dev->power.is_suspended = false;
 573
 574  Unlock:
 575         device_unlock(dev);
 576         complete_all(&dev->power.completion);
 577
 578         TRACE_RESUME(error);
 579
 580         if (put)
 581                 pm_runtime_put_sync(dev);
 582
 583         return error;
 584 }
 585
 586 static void async_resume(void *data, async_cookie_t cookie)
 587 {
 588         struct device *dev = (struct device *)data;
 589         int error;
 590
 591         error = device_resume(dev, pm_transition, true);
 592         if (error)
 593                 pm_dev_err(dev, pm_transition, " async", error);
 594         put_device(dev);
 595 }
 596
 597 static bool is_async(struct device *dev)
 598 {
 599         return dev->power.async_suspend && pm_async_enabled
 600                 && !pm_trace_is_enabled();
 601 }
 602
 603 /**
 604  * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
 605  * @state: PM transition of the system being carried out.
 606  *
 607  * Execute the appropriate "resume" callback for all devices whose status
 608  * indicates that they are suspended.
 609  */
 610 void dpm_resume(pm_message_t state)
 611 {
 612         struct device *dev;
 613         ktime_t starttime = ktime_get();
 614
 615         might_sleep();
 616
 617         mutex_lock(&dpm_list_mtx);
 618         pm_transition = state;
 619         async_error = 0;
 620
 621         list_for_each_entry(dev, &dpm_suspended_list, power.entry) {
 622                 INIT_COMPLETION(dev->power.completion);
 623                 if (is_async(dev)) {
 624                         get_device(dev);
 625                         async_schedule(async_resume, dev);
 626                 }
 627         }
 628
 629         while (!list_empty(&dpm_suspended_list)) {
 630                 dev = to_device(dpm_suspended_list.next);
 631                 get_device(dev);
 632                 if (!is_async(dev)) {
 633                         int error;
 634
 635                         mutex_unlock(&dpm_list_mtx);
 636
 637                         error = device_resume(dev, state, false);
 638                         if (error) {
 639                                 suspend_stats.failed_resume++;
 640                                 dpm_save_failed_step(SUSPEND_RESUME);
 641                                 dpm_save_failed_dev(dev_name(dev));
 642                                 pm_dev_err(dev, state, "", error);
 643                         }
 644
 645                         mutex_lock(&dpm_list_mtx);
 646                 }
 647                 if (!list_empty(&dev->power.entry))
 648                         list_move_tail(&dev->power.entry, &dpm_prepared_list);
 649                 put_device(dev);
 650         }
 651         mutex_unlock(&dpm_list_mtx);
 652         async_synchronize_full();
 653         dpm_show_time(starttime, state, NULL);
 654 }
 655
 656 /**
 657  * device_complete - Complete a PM transition for given device.
 658  * @dev: Device to handle.
 659  * @state: PM transition of the system being carried out.
 660  */
 661 static void device_complete(struct device *dev, pm_message_t state)
 662 {
 663         device_lock(dev);
 664
 665         if (dev->pm_domain) {
 666                 pm_dev_dbg(dev, state, "completing power domain ");
 667                 if (dev->pm_domain->ops.complete)
 668                         dev->pm_domain->ops.complete(dev);
 669         } else if (dev->type && dev->type->pm) {
 670                 pm_dev_dbg(dev, state, "completing type ");
 671                 if (dev->type->pm->complete)
 672                         dev->type->pm->complete(dev);
 673         } else if (dev->class && dev->class->pm) {
 674                 pm_dev_dbg(dev, state, "completing class ");
 675                 if (dev->class->pm->complete)
 676                         dev->class->pm->complete(dev);
 677         } else if (dev->bus && dev->bus->pm) {
 678                 pm_dev_dbg(dev, state, "completing ");
 679                 if (dev->bus->pm->complete)
 680                         dev->bus->pm->complete(dev);
 681         }
 682
 683         device_unlock(dev);
 684 }
 685
 686 /**
 687  * dpm_complete - Complete a PM transition for all non-sysdev devices.
 688  * @state: PM transition of the system being carried out.
 689  *
 690  * Execute the ->complete() callbacks for all devices whose PM status is not
 691  * DPM_ON (this allows new devices to be registered).
 692  */
 693 void dpm_complete(pm_message_t state)
 694 {
 695         struct list_head list;
 696
 697         might_sleep();
 698
 699         INIT_LIST_HEAD(&list);
 700         mutex_lock(&dpm_list_mtx);
 701         while (!list_empty(&dpm_prepared_list)) {
 702                 struct device *dev = to_device(dpm_prepared_list.prev);
 703
 704                 get_device(dev);
 705                 dev->power.is_prepared = false;
 706                 list_move(&dev->power.entry, &list);
 707                 mutex_unlock(&dpm_list_mtx);
 708
 709                 device_complete(dev, state);
 710
 711                 mutex_lock(&dpm_list_mtx);
 712                 put_device(dev);
 713         }
 714         list_splice(&list, &dpm_list);
 715         mutex_unlock(&dpm_list_mtx);
 716 }
 717
 718 /**
 719  * dpm_resume_end - Execute "resume" callbacks and complete system transition.
 720  * @state: PM transition of the system being carried out.
 721  *
 722  * Execute "resume" callbacks for all devices and complete the PM transition of
 723  * the system.
 724  */
 725 void dpm_resume_end(pm_message_t state)
 726 {
 727         dpm_resume(state);
 728         dpm_complete(state);
 729 }
 730 EXPORT_SYMBOL_GPL(dpm_resume_end);
 731
 732
 733 /*------------------------- Suspend routines -------------------------*/
 734
 735 /**
 736  * resume_event - Return a "resume" message for given "suspend" sleep state.
 737  * @sleep_state: PM message representing a sleep state.
 738  *
 739  * Return a PM message representing the resume event corresponding to given
 740  * sleep state.
 741  */
 742 static pm_message_t resume_event(pm_message_t sleep_state)
 743 {
 744         switch (sleep_state.event) {
 745         case PM_EVENT_SUSPEND:
 746                 return PMSG_RESUME;
 747         case PM_EVENT_FREEZE:
 748         case PM_EVENT_QUIESCE:
 749                 return PMSG_RECOVER;
 750         case PM_EVENT_HIBERNATE:
 751                 return PMSG_RESTORE;
 752         }
 753         return PMSG_ON;
 754 }
 755
 756 /**
 757  * device_suspend_noirq - Execute a "late suspend" callback for given device.
 758  * @dev: Device to handle.
 759  * @state: PM transition of the system being carried out.
 760  *
 761  * The driver of @dev will not receive interrupts while this function is being
 762  * executed.
 763  */
 764 static int device_suspend_noirq(struct device *dev, pm_message_t state)
 765 {
 766         int error = 0;
 767
 768         if (dev->pm_domain) {
 769                 pm_dev_dbg(dev, state, "LATE power domain ");
 770                 error = pm_noirq_op(dev, &dev->pm_domain->ops, state);
 771         } else if (dev->type && dev->type->pm) {
 772                 pm_dev_dbg(dev, state, "LATE type ");
 773                 error = pm_noirq_op(dev, dev->type->pm, state);
 774         } else if (dev->class && dev->class->pm) {
 775                 pm_dev_dbg(dev, state, "LATE class ");
 776                 error = pm_noirq_op(dev, dev->class->pm, state);
 777         } else if (dev->bus && dev->bus->pm) {
 778                 pm_dev_dbg(dev, state, "LATE ");
 779                 error = pm_noirq_op(dev, dev->bus->pm, state);
 780         }
 781
 782         return error;
 783 }
 784
 785 /**
 786  * dpm_suspend_noirq - Execute "late suspend" callbacks for non-sysdev devices.
 787  * @state: PM transition of the system being carried out.
 788  *
 789  * Prevent device drivers from receiving interrupts and call the "noirq" suspend
 790  * handlers for all non-sysdev devices.
 791  */
 792 int dpm_suspend_noirq(pm_message_t state)
 793 {
 794         ktime_t starttime = ktime_get();
 795         int error = 0;
 796
 797         suspend_device_irqs();
 798         mutex_lock(&dpm_list_mtx);
 799         while (!list_empty(&dpm_suspended_list)) {
 800                 struct device *dev = to_device(dpm_suspended_list.prev);
 801
 802                 get_device(dev);
 803                 mutex_unlock(&dpm_list_mtx);
 804
 805                 error = device_suspend_noirq(dev, state);
 806
 807                 mutex_lock(&dpm_list_mtx);
 808                 if (error) {
 809                         pm_dev_err(dev, state, " late", error);
 810                         suspend_stats.failed_suspend_noirq++;
 811                         dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ);
 812                         dpm_save_failed_dev(dev_name(dev));
 813                         put_device(dev);
 814                         break;
 815                 }
 816                 if (!list_empty(&dev->power.entry))
 817                         list_move(&dev->power.entry, &dpm_noirq_list);
 818                 put_device(dev);
 819         }
 820         mutex_unlock(&dpm_list_mtx);
 821         if (error)
 822                 dpm_resume_noirq(resume_event(state));
 823         else
 824                 dpm_show_time(starttime, state, "late");
 825         return error;
 826 }
 827 EXPORT_SYMBOL_GPL(dpm_suspend_noirq);
 828
 829 /**
 830  * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
 831  * @dev: Device to suspend.
 832  * @state: PM transition of the system being carried out.
 833  * @cb: Suspend callback to execute.
 834  */
 835 static int legacy_suspend(struct device *dev, pm_message_t state,
 836                           int (*cb)(struct device *dev, pm_message_t state))
 837 {
 838         int error;
 839         ktime_t calltime;
 840
 841         calltime = initcall_debug_start(dev);
 842
 843         error = cb(dev, state);
 844         suspend_report_result(cb, error);
 845
 846         initcall_debug_report(dev, calltime, error);
 847
 848         return error;
 849 }
 850
 851 /**
 852  * device_suspend - Execute "suspend" callbacks for given device.
 853  * @dev: Device to handle.
 854  * @state: PM transition of the system being carried out.
 855  * @async: If true, the device is being suspended asynchronously.
 856  */
 857 static int __device_suspend(struct device *dev, pm_message_t state, bool async)
 858 {
 859         int error = 0;
 860
 861         dpm_wait_for_children(dev, async);
 862
 863         if (async_error)
 864                 return 0;
 865
 866         pm_runtime_get_noresume(dev);
 867         if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
 868                 pm_wakeup_event(dev, 0);
 869
 870         if (pm_wakeup_pending()) {
 871                 pm_runtime_put_sync(dev);
 872                 async_error = -EBUSY;
 873                 return 0;
 874         }
 875
 876         device_lock(dev);
 877
 878         if (dev->pm_domain) {
 879                 pm_dev_dbg(dev, state, "power domain ");
 880                 error = pm_op(dev, &dev->pm_domain->ops, state);
 881                 goto End;
 882         }
 883
 884         if (dev->type && dev->type->pm) {
 885                 pm_dev_dbg(dev, state, "type ");
 886                 error = pm_op(dev, dev->type->pm, state);
 887                 goto End;
 888         }
 889
 890         if (dev->class) {
 891                 if (dev->class->pm) {
 892                         pm_dev_dbg(dev, state, "class ");
 893                         error = pm_op(dev, dev->class->pm, state);
 894                         goto End;
 895                 } else if (dev->class->suspend) {
 896                         pm_dev_dbg(dev, state, "legacy class ");
 897                         error = legacy_suspend(dev, state, dev->class->suspend);
 898                         goto End;
 899                 }
 900         }
 901
 902         if (dev->bus) {
 903                 if (dev->bus->pm) {
 904                         pm_dev_dbg(dev, state, "");
 905                         error = pm_op(dev, dev->bus->pm, state);
 906                 } else if (dev->bus->suspend) {
 907                         pm_dev_dbg(dev, state, "legacy ");
 908                         error = legacy_suspend(dev, state, dev->bus->suspend);
 909                 }
 910         }
 911
 912  End:
 913         if (!error) {
 914                 dev->power.is_suspended = true;
 915                 if (dev->power.wakeup_path
 916                     && dev->parent && !dev->parent->power.ignore_children)
 917                         dev->parent->power.wakeup_path = true;
 918         }
 919
 920         device_unlock(dev);
 921         complete_all(&dev->power.completion);
 922
 923         if (error) {
 924                 pm_runtime_put_sync(dev);
 925                 async_error = error;
 926         } else if (dev->power.is_suspended) {
 927                 __pm_runtime_disable(dev, false);
 928         }
 929
 930         return error;
 931 }
 932
 933 static void async_suspend(void *data, async_cookie_t cookie)
 934 {
 935         struct device *dev = (struct device *)data;
 936         int error;
 937
 938         error = __device_suspend(dev, pm_transition, true);
 939         if (error) {
 940                 dpm_save_failed_dev(dev_name(dev));
 941                 pm_dev_err(dev, pm_transition, " async", error);
 942         }
 943
 944         put_device(dev);
 945 }
 946
 947 static int device_suspend(struct device *dev)
 948 {
 949         INIT_COMPLETION(dev->power.completion);
 950
 951         if (pm_async_enabled && dev->power.async_suspend) {
 952                 get_device(dev);
 953                 async_schedule(async_suspend, dev);
 954                 return 0;
 955         }
 956
 957         return __device_suspend(dev, pm_transition, false);
 958 }
 959
 960 /**
 961  * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
 962  * @state: PM transition of the system being carried out.
 963  */
 964 int dpm_suspend(pm_message_t state)
 965 {
 966         ktime_t starttime = ktime_get();
 967         int error = 0;
 968
 969         might_sleep();
 970
 971         mutex_lock(&dpm_list_mtx);
 972         pm_transition = state;
 973         async_error = 0;
 974         while (!list_empty(&dpm_prepared_list)) {
 975                 struct device *dev = to_device(dpm_prepared_list.prev);
 976
 977                 get_device(dev);
 978                 mutex_unlock(&dpm_list_mtx);
 979
 980                 error = device_suspend(dev);
 981
 982                 mutex_lock(&dpm_list_mtx);
 983                 if (error) {
 984                         pm_dev_err(dev, state, "", error);
 985                         dpm_save_failed_dev(dev_name(dev));
 986                         put_device(dev);
 987                         break;
 988                 }
 989                 if (!list_empty(&dev->power.entry))
 990                         list_move(&dev->power.entry, &dpm_suspended_list);
 991                 put_device(dev);
 992                 if (async_error)
 993                         break;
 994         }
 995         mutex_unlock(&dpm_list_mtx);
 996         async_synchronize_full();
 997         if (!error)
 998                 error = async_error;
 999         if (error) {
1000                 suspend_stats.failed_suspend++;
1001                 dpm_save_failed_step(SUSPEND_SUSPEND);
1002         } else
1003                 dpm_show_time(starttime, state, NULL);
1004         return error;
1005 }
1006
1007 /**
1008  * device_prepare - Prepare a device for system power transition.
1009  * @dev: Device to handle.
1010  * @state: PM transition of the system being carried out.
1011  *
1012  * Execute the ->prepare() callback(s) for given device.  No new children of the
1013  * device may be registered after this function has returned.
1014  */
1015 static int device_prepare(struct device *dev, pm_message_t state)
1016 {
1017         int error = 0;
1018
1019         device_lock(dev);
1020
1021         dev->power.wakeup_path = device_may_wakeup(dev);
1022
1023         if (dev->pm_domain) {
1024                 pm_dev_dbg(dev, state, "preparing power domain ");
1025                 if (dev->pm_domain->ops.prepare)
1026                         error = dev->pm_domain->ops.prepare(dev);
1027                 suspend_report_result(dev->pm_domain->ops.prepare, error);
1028         } else if (dev->type && dev->type->pm) {
1029                 pm_dev_dbg(dev, state, "preparing type ");
1030                 if (dev->type->pm->prepare)
1031                         error = dev->type->pm->prepare(dev);
1032                 suspend_report_result(dev->type->pm->prepare, error);
1033         } else if (dev->class && dev->class->pm) {
1034                 pm_dev_dbg(dev, state, "preparing class ");
1035                 if (dev->class->pm->prepare)
1036                         error = dev->class->pm->prepare(dev);
1037                 suspend_report_result(dev->class->pm->prepare, error);
1038         } else if (dev->bus && dev->bus->pm) {
1039                 pm_dev_dbg(dev, state, "preparing ");
1040                 if (dev->bus->pm->prepare)
1041                         error = dev->bus->pm->prepare(dev);
1042                 suspend_report_result(dev->bus->pm->prepare, error);
1043         }
1044
1045         device_unlock(dev);
1046
1047         return error;
1048 }
1049
1050 /**
1051  * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1052  * @state: PM transition of the system being carried out.
1053  *
1054  * Execute the ->prepare() callback(s) for all devices.
1055  */
1056 int dpm_prepare(pm_message_t state)
1057 {
1058         int error = 0;
1059
1060         might_sleep();
1061
1062         mutex_lock(&dpm_list_mtx);
1063         while (!list_empty(&dpm_list)) {
1064                 struct device *dev = to_device(dpm_list.next);
1065
1066                 get_device(dev);
1067                 mutex_unlock(&dpm_list_mtx);
1068
1069                 error = device_prepare(dev, state);
1070
1071                 mutex_lock(&dpm_list_mtx);
1072                 if (error) {
1073                         if (error == -EAGAIN) {
1074                                 put_device(dev);
1075                                 error = 0;
1076                                 continue;
1077                         }
1078                         printk(KERN_INFO "PM: Device %s not prepared "
1079                                 "for power transition: code %d\n",
1080                                 dev_name(dev), error);
1081                         put_device(dev);
1082                         break;
1083                 }
1084                 dev->power.is_prepared = true;
1085                 if (!list_empty(&dev->power.entry))
1086                         list_move_tail(&dev->power.entry, &dpm_prepared_list);
1087                 put_device(dev);
1088         }
1089         mutex_unlock(&dpm_list_mtx);
1090         return error;
1091 }
1092
1093 /**
1094  * dpm_suspend_start - Prepare devices for PM transition and suspend them.
1095  * @state: PM transition of the system being carried out.
1096  *
1097  * Prepare all non-sysdev devices for system PM transition and execute "suspend"
1098  * callbacks for them.
1099  */
1100 int dpm_suspend_start(pm_message_t state)
1101 {
1102         int error;
1103
1104         error = dpm_prepare(state);
1105         if (error) {
1106                 suspend_stats.failed_prepare++;
1107                 dpm_save_failed_step(SUSPEND_PREPARE);
1108         } else
1109                 error = dpm_suspend(state);
1110         return error;
1111 }
1112 EXPORT_SYMBOL_GPL(dpm_suspend_start);
1113
1114 void __suspend_report_result(const char *function, void *fn, int ret)
1115 {
1116         if (ret)
1117                 printk(KERN_ERR "%s(): %pF returns %d\n", function, fn, ret);
1118 }
1119 EXPORT_SYMBOL_GPL(__suspend_report_result);
1120
1121 /**
1122  * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
1123  * @dev: Device to wait for.
1124  * @subordinate: Device that needs to wait for @dev.
1125  */
1126 int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
1127 {
1128         dpm_wait(dev, subordinate->power.async_suspend);
1129         return async_error;
1130 }
1131 EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);