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 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 LIST_HEAD(dpm_prepared_list);
  49 LIST_HEAD(dpm_suspended_list);
  50 LIST_HEAD(dpm_noirq_list);
  51
  52 struct suspend_stats suspend_stats;
  53 static DEFINE_MUTEX(dpm_list_mtx);
  54 static pm_message_t pm_transition;
  55
  56 static int async_error;
  57
  58 /**
  59  * device_pm_init - Initialize the PM-related part of a device object.
  60  * @dev: Device object being initialized.
  61  */
  62 void device_pm_init(struct device *dev)
  63 {
  64         dev->power.is_prepared = false;
  65         dev->power.is_suspended = false;
  66         init_completion(&dev->power.completion);
  67         complete_all(&dev->power.completion);
  68         dev->power.wakeup = NULL;
  69         spin_lock_init(&dev->power.lock);
  70         pm_runtime_init(dev);
  71         INIT_LIST_HEAD(&dev->power.entry);
  72         dev->power.power_state = PMSG_INVALID;
  73 }
  74
  75 /**
  76  * device_pm_lock - Lock the list of active devices used by the PM core.
  77  */
  78 void device_pm_lock(void)
  79 {
  80         mutex_lock(&dpm_list_mtx);
  81 }
  82
  83 /**
  84  * device_pm_unlock - Unlock the list of active devices used by the PM core.
  85  */
  86 void device_pm_unlock(void)
  87 {
  88         mutex_unlock(&dpm_list_mtx);
  89 }
  90
  91 /**
  92  * device_pm_add - Add a device to the PM core's list of active devices.
  93  * @dev: Device to add to the list.
  94  */
  95 void device_pm_add(struct device *dev)
  96 {
  97         pr_debug("PM: Adding info for %s:%s\n",
  98                  dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
  99         mutex_lock(&dpm_list_mtx);
 100         if (dev->parent && dev->parent->power.is_prepared)
 101                 dev_warn(dev, "parent %s should not be sleeping\n",
 102                         dev_name(dev->parent));
 103         list_add_tail(&dev->power.entry, &dpm_list);
 104         dev_pm_qos_constraints_init(dev);
 105         mutex_unlock(&dpm_list_mtx);
 106 }
 107
 108 /**
 109  * device_pm_remove - Remove a device from the PM core's list of active devices.
 110  * @dev: Device to be removed from the list.
 111  */
 112 void device_pm_remove(struct device *dev)
 113 {
 114         pr_debug("PM: Removing info for %s:%s\n",
 115                  dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 116         complete_all(&dev->power.completion);
 117         mutex_lock(&dpm_list_mtx);
 118         dev_pm_qos_constraints_destroy(dev);
 119         list_del_init(&dev->power.entry);
 120         mutex_unlock(&dpm_list_mtx);
 121         device_wakeup_disable(dev);
 122         pm_runtime_remove(dev);
 123 }
 124
 125 /**
 126  * device_pm_move_before - Move device in the PM core's list of active devices.
 127  * @deva: Device to move in dpm_list.
 128  * @devb: Device @deva should come before.
 129  */
 130 void device_pm_move_before(struct device *deva, struct device *devb)
 131 {
 132         pr_debug("PM: Moving %s:%s before %s:%s\n",
 133                  deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
 134                  devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
 135         /* Delete deva from dpm_list and reinsert before devb. */
 136         list_move_tail(&deva->power.entry, &devb->power.entry);
 137 }
 138
 139 /**
 140  * device_pm_move_after - Move device in the PM core's list of active devices.
 141  * @deva: Device to move in dpm_list.
 142  * @devb: Device @deva should come after.
 143  */
 144 void device_pm_move_after(struct device *deva, struct device *devb)
 145 {
 146         pr_debug("PM: Moving %s:%s after %s:%s\n",
 147                  deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
 148                  devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
 149         /* Delete deva from dpm_list and reinsert after devb. */
 150         list_move(&deva->power.entry, &devb->power.entry);
 151 }
 152
 153 /**
 154  * device_pm_move_last - Move device to end of the PM core's list of devices.
 155  * @dev: Device to move in dpm_list.
 156  */
 157 void device_pm_move_last(struct device *dev)
 158 {
 159         pr_debug("PM: Moving %s:%s to end of list\n",
 160                  dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
 161         list_move_tail(&dev->power.entry, &dpm_list);
 162 }
 163
 164 static ktime_t initcall_debug_start(struct device *dev)
 165 {
 166         ktime_t calltime = ktime_set(0, 0);
 167
 168         if (initcall_debug) {
 169                 pr_info("calling  %s+ @ %i, parent: %s\n",
 170                         dev_name(dev), task_pid_nr(current),
 171                         dev->parent ? dev_name(dev->parent) : "none");
 172                 calltime = ktime_get();
 173         }
 174
 175         return calltime;
 176 }
 177
 178 static void initcall_debug_report(struct device *dev, ktime_t calltime,
 179                                   int error)
 180 {
 181         ktime_t delta, rettime;
 182
 183         if (initcall_debug) {
 184                 rettime = ktime_get();
 185                 delta = ktime_sub(rettime, calltime);
 186                 pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev),
 187                         error, (unsigned long long)ktime_to_ns(delta) >> 10);
 188         }
 189 }
 190
 191 /**
 192  * dpm_wait - Wait for a PM operation to complete.
 193  * @dev: Device to wait for.
 194  * @async: If unset, wait only if the device's power.async_suspend flag is set.
 195  */
 196 static void dpm_wait(struct device *dev, bool async)
 197 {
 198         if (!dev)
 199                 return;
 200
 201         if (async || (pm_async_enabled && dev->power.async_suspend))
 202                 wait_for_completion(&dev->power.completion);
 203 }
 204
 205 static int dpm_wait_fn(struct device *dev, void *async_ptr)
 206 {
 207         dpm_wait(dev, *((bool *)async_ptr));
 208         return 0;
 209 }
 210
 211 static void dpm_wait_for_children(struct device *dev, bool async)
 212 {
 213        device_for_each_child(dev, &async, dpm_wait_fn);
 214 }
 215
 216 /**
 217  * pm_op - Return the PM operation appropriate for given PM event.
 218  * @ops: PM operations to choose from.
 219  * @state: PM transition of the system being carried out.
 220  */
 221 static pm_callback_t pm_op(const struct dev_pm_ops *ops, pm_message_t state)
 222 {
 223         switch (state.event) {
 224 #ifdef CONFIG_SUSPEND
 225         case PM_EVENT_SUSPEND:
 226                 return ops->suspend;
 227         case PM_EVENT_RESUME:
 228                 return ops->resume;
 229 #endif /* CONFIG_SUSPEND */
 230 #ifdef CONFIG_HIBERNATE_CALLBACKS
 231         case PM_EVENT_FREEZE:
 232         case PM_EVENT_QUIESCE:
 233                 return ops->freeze;
 234         case PM_EVENT_HIBERNATE:
 235                 return ops->poweroff;
 236         case PM_EVENT_THAW:
 237         case PM_EVENT_RECOVER:
 238                 return ops->thaw;
 239                 break;
 240         case PM_EVENT_RESTORE:
 241                 return ops->restore;
 242 #endif /* CONFIG_HIBERNATE_CALLBACKS */
 243         }
 244
 245         return NULL;
 246 }
 247
 248 /**
 249  * pm_noirq_op - Return the PM operation appropriate for given PM event.
 250  * @ops: PM operations to choose from.
 251  * @state: PM transition of the system being carried out.
 252  *
 253  * The driver of @dev will not receive interrupts while this function is being
 254  * executed.
 255  */
 256 static pm_callback_t pm_noirq_op(const struct dev_pm_ops *ops, pm_message_t state)
 257 {
 258         switch (state.event) {
 259 #ifdef CONFIG_SUSPEND
 260         case PM_EVENT_SUSPEND:
 261                 return ops->suspend_noirq;
 262         case PM_EVENT_RESUME:
 263                 return ops->resume_noirq;
 264 #endif /* CONFIG_SUSPEND */
 265 #ifdef CONFIG_HIBERNATE_CALLBACKS
 266         case PM_EVENT_FREEZE:
 267         case PM_EVENT_QUIESCE:
 268                 return ops->freeze_noirq;
 269         case PM_EVENT_HIBERNATE:
 270                 return ops->poweroff_noirq;
 271         case PM_EVENT_THAW:
 272         case PM_EVENT_RECOVER:
 273                 return ops->thaw_noirq;
 274         case PM_EVENT_RESTORE:
 275                 return ops->restore_noirq;
 276 #endif /* CONFIG_HIBERNATE_CALLBACKS */
 277         }
 278
 279         return NULL;
 280 }
 281
 282 static char *pm_verb(int event)
 283 {
 284         switch (event) {
 285         case PM_EVENT_SUSPEND:
 286                 return "suspend";
 287         case PM_EVENT_RESUME:
 288                 return "resume";
 289         case PM_EVENT_FREEZE:
 290                 return "freeze";
 291         case PM_EVENT_QUIESCE:
 292                 return "quiesce";
 293         case PM_EVENT_HIBERNATE:
 294                 return "hibernate";
 295         case PM_EVENT_THAW:
 296                 return "thaw";
 297         case PM_EVENT_RESTORE:
 298                 return "restore";
 299         case PM_EVENT_RECOVER:
 300                 return "recover";
 301         default:
 302                 return "(unknown PM event)";
 303         }
 304 }
 305
 306 static void pm_dev_dbg(struct device *dev, pm_message_t state, char *info)
 307 {
 308         dev_dbg(dev, "%s%s%s\n", info, pm_verb(state.event),
 309                 ((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
 310                 ", may wakeup" : "");
 311 }
 312
 313 static void pm_dev_err(struct device *dev, pm_message_t state, char *info,
 314                         int error)
 315 {
 316         printk(KERN_ERR "PM: Device %s failed to %s%s: error %d\n",
 317                 dev_name(dev), pm_verb(state.event), info, error);
 318 }
 319
 320 static void dpm_show_time(ktime_t starttime, pm_message_t state, char *info)
 321 {
 322         ktime_t calltime;
 323         u64 usecs64;
 324         int usecs;
 325
 326         calltime = ktime_get();
 327         usecs64 = ktime_to_ns(ktime_sub(calltime, starttime));
 328         do_div(usecs64, NSEC_PER_USEC);
 329         usecs = usecs64;
 330         if (usecs == 0)
 331                 usecs = 1;
 332         pr_info("PM: %s%s%s of devices complete after %ld.%03ld msecs\n",
 333                 info ?: "", info ? " " : "", pm_verb(state.event),
 334                 usecs / USEC_PER_MSEC, usecs % USEC_PER_MSEC);
 335 }
 336
 337 static int dpm_run_callback(pm_callback_t cb, struct device *dev,
 338                             pm_message_t state, char *info)
 339 {
 340         ktime_t calltime;
 341         int error;
 342
 343         if (!cb)
 344                 return 0;
 345
 346         calltime = initcall_debug_start(dev);
 347
 348         pm_dev_dbg(dev, state, info);
 349         error = cb(dev);
 350         suspend_report_result(cb, error);
 351
 352         initcall_debug_report(dev, calltime, error);
 353
 354         return error;
 355 }
 356
 357 /*------------------------- Resume routines -------------------------*/
 358
 359 /**
 360  * device_resume_noirq - Execute an "early resume" callback for given device.
 361  * @dev: Device to handle.
 362  * @state: PM transition of the system being carried out.
 363  *
 364  * The driver of @dev will not receive interrupts while this function is being
 365  * executed.
 366  */
 367 static int device_resume_noirq(struct device *dev, pm_message_t state)
 368 {
 369         pm_callback_t callback = NULL;
 370         char *info = NULL;
 371         int error = 0;
 372
 373         TRACE_DEVICE(dev);
 374         TRACE_RESUME(0);
 375
 376         if (dev->pm_domain) {
 377                 info = "EARLY power domain ";
 378                 callback = pm_noirq_op(&dev->pm_domain->ops, state);
 379         } else if (dev->type && dev->type->pm) {
 380                 info = "EARLY type ";
 381                 callback = pm_noirq_op(dev->type->pm, state);
 382         } else if (dev->class && dev->class->pm) {
 383                 info = "EARLY class ";
 384                 callback = pm_noirq_op(dev->class->pm, state);
 385         } else if (dev->bus && dev->bus->pm) {
 386                 info = "EARLY ";
 387                 callback = pm_noirq_op(dev->bus->pm, state);
 388         }
 389
 390         error = dpm_run_callback(callback, dev, state, info);
 391
 392         TRACE_RESUME(error);
 393         return error;
 394 }
 395
 396 /**
 397  * dpm_resume_noirq - Execute "early resume" callbacks for non-sysdev devices.
 398  * @state: PM transition of the system being carried out.
 399  *
 400  * Call the "noirq" resume handlers for all devices marked as DPM_OFF_IRQ and
 401  * enable device drivers to receive interrupts.
 402  */
 403 void dpm_resume_noirq(pm_message_t state)
 404 {
 405         ktime_t starttime = ktime_get();
 406
 407         mutex_lock(&dpm_list_mtx);
 408         while (!list_empty(&dpm_noirq_list)) {
 409                 struct device *dev = to_device(dpm_noirq_list.next);
 410                 int error;
 411
 412                 get_device(dev);
 413                 list_move_tail(&dev->power.entry, &dpm_suspended_list);
 414                 mutex_unlock(&dpm_list_mtx);
 415
 416                 error = device_resume_noirq(dev, state);
 417                 if (error) {
 418                         suspend_stats.failed_resume_noirq++;
 419                         dpm_save_failed_step(SUSPEND_RESUME_NOIRQ);
 420                         dpm_save_failed_dev(dev_name(dev));
 421                         pm_dev_err(dev, state, " early", error);
 422                 }
 423
 424                 mutex_lock(&dpm_list_mtx);
 425                 put_device(dev);
 426         }
 427         mutex_unlock(&dpm_list_mtx);
 428         dpm_show_time(starttime, state, "early");
 429         resume_device_irqs();
 430 }
 431 EXPORT_SYMBOL_GPL(dpm_resume_noirq);
 432
 433 /**
 434  * device_resume - Execute "resume" callbacks for given device.
 435  * @dev: Device to handle.
 436  * @state: PM transition of the system being carried out.
 437  * @async: If true, the device is being resumed asynchronously.
 438  */
 439 static int device_resume(struct device *dev, pm_message_t state, bool async)
 440 {
 441         pm_callback_t callback = NULL;
 442         char *info = NULL;
 443         int error = 0;
 444         bool put = false;
 445
 446         TRACE_DEVICE(dev);
 447         TRACE_RESUME(0);
 448
 449         dpm_wait(dev->parent, async);
 450         device_lock(dev);
 451
 452         /*
 453          * This is a fib.  But we'll allow new children to be added below
 454          * a resumed device, even if the device hasn't been completed yet.
 455          */
 456         dev->power.is_prepared = false;
 457
 458         if (!dev->power.is_suspended)
 459                 goto Unlock;
 460
 461         pm_runtime_enable(dev);
 462         put = true;
 463
 464         if (dev->pm_domain) {
 465                 info = "power domain ";
 466                 callback = pm_op(&dev->pm_domain->ops, state);
 467                 goto End;
 468         }
 469
 470         if (dev->type && dev->type->pm) {
 471                 info = "type ";
 472                 callback = pm_op(dev->type->pm, state);
 473                 goto End;
 474         }
 475
 476         if (dev->class) {
 477                 if (dev->class->pm) {
 478                         info = "class ";
 479                         callback = pm_op(dev->class->pm, state);
 480                         goto End;
 481                 } else if (dev->class->resume) {
 482                         info = "legacy class ";
 483                         callback = dev->class->resume;
 484                         goto End;
 485                 }
 486         }
 487
 488         if (dev->bus) {
 489                 if (dev->bus->pm) {
 490                         info = "";
 491                         callback = pm_op(dev->bus->pm, state);
 492                 } else if (dev->bus->resume) {
 493                         info = "legacy ";
 494                         callback = dev->bus->resume;
 495                 }
 496         }
 497
 498  End:
 499         error = dpm_run_callback(callback, dev, state, info);
 500         dev->power.is_suspended = false;
 501
 502  Unlock:
 503         device_unlock(dev);
 504         complete_all(&dev->power.completion);
 505
 506         TRACE_RESUME(error);
 507
 508         if (put)
 509                 pm_runtime_put_sync(dev);
 510
 511         return error;
 512 }
 513
 514 static void async_resume(void *data, async_cookie_t cookie)
 515 {
 516         struct device *dev = (struct device *)data;
 517         int error;
 518
 519         error = device_resume(dev, pm_transition, true);
 520         if (error)
 521                 pm_dev_err(dev, pm_transition, " async", error);
 522         put_device(dev);
 523 }
 524
 525 static bool is_async(struct device *dev)
 526 {
 527         return dev->power.async_suspend && pm_async_enabled
 528                 && !pm_trace_is_enabled();
 529 }
 530
 531 /**
 532  * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
 533  * @state: PM transition of the system being carried out.
 534  *
 535  * Execute the appropriate "resume" callback for all devices whose status
 536  * indicates that they are suspended.
 537  */
 538 void dpm_resume(pm_message_t state)
 539 {
 540         struct device *dev;
 541         ktime_t starttime = ktime_get();
 542
 543         might_sleep();
 544
 545         mutex_lock(&dpm_list_mtx);
 546         pm_transition = state;
 547         async_error = 0;
 548
 549         list_for_each_entry(dev, &dpm_suspended_list, power.entry) {
 550                 INIT_COMPLETION(dev->power.completion);
 551                 if (is_async(dev)) {
 552                         get_device(dev);
 553                         async_schedule(async_resume, dev);
 554                 }
 555         }
 556
 557         while (!list_empty(&dpm_suspended_list)) {
 558                 dev = to_device(dpm_suspended_list.next);
 559                 get_device(dev);
 560                 if (!is_async(dev)) {
 561                         int error;
 562
 563                         mutex_unlock(&dpm_list_mtx);
 564
 565                         error = device_resume(dev, state, false);
 566                         if (error) {
 567                                 suspend_stats.failed_resume++;
 568                                 dpm_save_failed_step(SUSPEND_RESUME);
 569                                 dpm_save_failed_dev(dev_name(dev));
 570                                 pm_dev_err(dev, state, "", error);
 571                         }
 572
 573                         mutex_lock(&dpm_list_mtx);
 574                 }
 575                 if (!list_empty(&dev->power.entry))
 576                         list_move_tail(&dev->power.entry, &dpm_prepared_list);
 577                 put_device(dev);
 578         }
 579         mutex_unlock(&dpm_list_mtx);
 580         async_synchronize_full();
 581         dpm_show_time(starttime, state, NULL);
 582 }
 583
 584 /**
 585  * device_complete - Complete a PM transition for given device.
 586  * @dev: Device to handle.
 587  * @state: PM transition of the system being carried out.
 588  */
 589 static void device_complete(struct device *dev, pm_message_t state)
 590 {
 591         device_lock(dev);
 592
 593         if (dev->pm_domain) {
 594                 pm_dev_dbg(dev, state, "completing power domain ");
 595                 if (dev->pm_domain->ops.complete)
 596                         dev->pm_domain->ops.complete(dev);
 597         } else if (dev->type && dev->type->pm) {
 598                 pm_dev_dbg(dev, state, "completing type ");
 599                 if (dev->type->pm->complete)
 600                         dev->type->pm->complete(dev);
 601         } else if (dev->class && dev->class->pm) {
 602                 pm_dev_dbg(dev, state, "completing class ");
 603                 if (dev->class->pm->complete)
 604                         dev->class->pm->complete(dev);
 605         } else if (dev->bus && dev->bus->pm) {
 606                 pm_dev_dbg(dev, state, "completing ");
 607                 if (dev->bus->pm->complete)
 608                         dev->bus->pm->complete(dev);
 609         }
 610
 611         device_unlock(dev);
 612 }
 613
 614 /**
 615  * dpm_complete - Complete a PM transition for all non-sysdev devices.
 616  * @state: PM transition of the system being carried out.
 617  *
 618  * Execute the ->complete() callbacks for all devices whose PM status is not
 619  * DPM_ON (this allows new devices to be registered).
 620  */
 621 void dpm_complete(pm_message_t state)
 622 {
 623         struct list_head list;
 624
 625         might_sleep();
 626
 627         INIT_LIST_HEAD(&list);
 628         mutex_lock(&dpm_list_mtx);
 629         while (!list_empty(&dpm_prepared_list)) {
 630                 struct device *dev = to_device(dpm_prepared_list.prev);
 631
 632                 get_device(dev);
 633                 dev->power.is_prepared = false;
 634                 list_move(&dev->power.entry, &list);
 635                 mutex_unlock(&dpm_list_mtx);
 636
 637                 device_complete(dev, state);
 638
 639                 mutex_lock(&dpm_list_mtx);
 640                 put_device(dev);
 641         }
 642         list_splice(&list, &dpm_list);
 643         mutex_unlock(&dpm_list_mtx);
 644 }
 645
 646 /**
 647  * dpm_resume_end - Execute "resume" callbacks and complete system transition.
 648  * @state: PM transition of the system being carried out.
 649  *
 650  * Execute "resume" callbacks for all devices and complete the PM transition of
 651  * the system.
 652  */
 653 void dpm_resume_end(pm_message_t state)
 654 {
 655         dpm_resume(state);
 656         dpm_complete(state);
 657 }
 658 EXPORT_SYMBOL_GPL(dpm_resume_end);
 659
 660
 661 /*------------------------- Suspend routines -------------------------*/
 662
 663 /**
 664  * resume_event - Return a "resume" message for given "suspend" sleep state.
 665  * @sleep_state: PM message representing a sleep state.
 666  *
 667  * Return a PM message representing the resume event corresponding to given
 668  * sleep state.
 669  */
 670 static pm_message_t resume_event(pm_message_t sleep_state)
 671 {
 672         switch (sleep_state.event) {
 673         case PM_EVENT_SUSPEND:
 674                 return PMSG_RESUME;
 675         case PM_EVENT_FREEZE:
 676         case PM_EVENT_QUIESCE:
 677                 return PMSG_RECOVER;
 678         case PM_EVENT_HIBERNATE:
 679                 return PMSG_RESTORE;
 680         }
 681         return PMSG_ON;
 682 }
 683
 684 /**
 685  * device_suspend_noirq - Execute a "late suspend" callback for given device.
 686  * @dev: Device to handle.
 687  * @state: PM transition of the system being carried out.
 688  *
 689  * The driver of @dev will not receive interrupts while this function is being
 690  * executed.
 691  */
 692 static int device_suspend_noirq(struct device *dev, pm_message_t state)
 693 {
 694         pm_callback_t callback = NULL;
 695         char *info = NULL;
 696
 697         if (dev->pm_domain) {
 698                 info = "LATE power domain ";
 699                 callback = pm_noirq_op(&dev->pm_domain->ops, state);
 700         } else if (dev->type && dev->type->pm) {
 701                 info = "LATE type ";
 702                 callback = pm_noirq_op(dev->type->pm, state);
 703         } else if (dev->class && dev->class->pm) {
 704                 info = "LATE class ";
 705                 callback = pm_noirq_op(dev->class->pm, state);
 706         } else if (dev->bus && dev->bus->pm) {
 707                 info = "LATE ";
 708                 callback = pm_noirq_op(dev->bus->pm, state);
 709         }
 710
 711         return dpm_run_callback(callback, dev, state, info);
 712 }
 713
 714 /**
 715  * dpm_suspend_noirq - Execute "late suspend" callbacks for non-sysdev devices.
 716  * @state: PM transition of the system being carried out.
 717  *
 718  * Prevent device drivers from receiving interrupts and call the "noirq" suspend
 719  * handlers for all non-sysdev devices.
 720  */
 721 int dpm_suspend_noirq(pm_message_t state)
 722 {
 723         ktime_t starttime = ktime_get();
 724         int error = 0;
 725
 726         suspend_device_irqs();
 727         mutex_lock(&dpm_list_mtx);
 728         while (!list_empty(&dpm_suspended_list)) {
 729                 struct device *dev = to_device(dpm_suspended_list.prev);
 730
 731                 get_device(dev);
 732                 mutex_unlock(&dpm_list_mtx);
 733
 734                 error = device_suspend_noirq(dev, state);
 735
 736                 mutex_lock(&dpm_list_mtx);
 737                 if (error) {
 738                         pm_dev_err(dev, state, " late", error);
 739                         suspend_stats.failed_suspend_noirq++;
 740                         dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ);
 741                         dpm_save_failed_dev(dev_name(dev));
 742                         put_device(dev);
 743                         break;
 744                 }
 745                 if (!list_empty(&dev->power.entry))
 746                         list_move(&dev->power.entry, &dpm_noirq_list);
 747                 put_device(dev);
 748         }
 749         mutex_unlock(&dpm_list_mtx);
 750         if (error)
 751                 dpm_resume_noirq(resume_event(state));
 752         else
 753                 dpm_show_time(starttime, state, "late");
 754         return error;
 755 }
 756 EXPORT_SYMBOL_GPL(dpm_suspend_noirq);
 757
 758 /**
 759  * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
 760  * @dev: Device to suspend.
 761  * @state: PM transition of the system being carried out.
 762  * @cb: Suspend callback to execute.
 763  */
 764 static int legacy_suspend(struct device *dev, pm_message_t state,
 765                           int (*cb)(struct device *dev, pm_message_t state))
 766 {
 767         int error;
 768         ktime_t calltime;
 769
 770         calltime = initcall_debug_start(dev);
 771
 772         error = cb(dev, state);
 773         suspend_report_result(cb, error);
 774
 775         initcall_debug_report(dev, calltime, error);
 776
 777         return error;
 778 }
 779
 780 /**
 781  * device_suspend - Execute "suspend" callbacks for given device.
 782  * @dev: Device to handle.
 783  * @state: PM transition of the system being carried out.
 784  * @async: If true, the device is being suspended asynchronously.
 785  */
 786 static int __device_suspend(struct device *dev, pm_message_t state, bool async)
 787 {
 788         pm_callback_t callback = NULL;
 789         char *info = NULL;
 790         int error = 0;
 791
 792         dpm_wait_for_children(dev, async);
 793
 794         if (async_error)
 795                 return 0;
 796
 797         pm_runtime_get_noresume(dev);
 798         if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
 799                 pm_wakeup_event(dev, 0);
 800
 801         if (pm_wakeup_pending()) {
 802                 pm_runtime_put_sync(dev);
 803                 async_error = -EBUSY;
 804                 return 0;
 805         }
 806
 807         device_lock(dev);
 808
 809         if (dev->pm_domain) {
 810                 info = "power domain ";
 811                 callback = pm_op(&dev->pm_domain->ops, state);
 812                 goto Run;
 813         }
 814
 815         if (dev->type && dev->type->pm) {
 816                 info = "type ";
 817                 callback = pm_op(dev->type->pm, state);
 818                 goto Run;
 819         }
 820
 821         if (dev->class) {
 822                 if (dev->class->pm) {
 823                         info = "class ";
 824                         callback = pm_op(dev->class->pm, state);
 825                         goto Run;
 826                 } else if (dev->class->suspend) {
 827                         pm_dev_dbg(dev, state, "legacy class ");
 828                         error = legacy_suspend(dev, state, dev->class->suspend);
 829                         goto End;
 830                 }
 831         }
 832
 833         if (dev->bus) {
 834                 if (dev->bus->pm) {
 835                         info = "";
 836                         callback = pm_op(dev->bus->pm, state);
 837                 } else if (dev->bus->suspend) {
 838                         pm_dev_dbg(dev, state, "legacy ");
 839                         error = legacy_suspend(dev, state, dev->bus->suspend);
 840                         goto End;
 841                 }
 842         }
 843
 844  Run:
 845         error = dpm_run_callback(callback, dev, state, info);
 846
 847  End:
 848         if (!error) {
 849                 dev->power.is_suspended = true;
 850                 if (dev->power.wakeup_path
 851                     && dev->parent && !dev->parent->power.ignore_children)
 852                         dev->parent->power.wakeup_path = true;
 853         }
 854
 855         device_unlock(dev);
 856         complete_all(&dev->power.completion);
 857
 858         if (error) {
 859                 pm_runtime_put_sync(dev);
 860                 async_error = error;
 861         } else if (dev->power.is_suspended) {
 862                 __pm_runtime_disable(dev, false);
 863         }
 864
 865         return error;
 866 }
 867
 868 static void async_suspend(void *data, async_cookie_t cookie)
 869 {
 870         struct device *dev = (struct device *)data;
 871         int error;
 872
 873         error = __device_suspend(dev, pm_transition, true);
 874         if (error) {
 875                 dpm_save_failed_dev(dev_name(dev));
 876                 pm_dev_err(dev, pm_transition, " async", error);
 877         }
 878
 879         put_device(dev);
 880 }
 881
 882 static int device_suspend(struct device *dev)
 883 {
 884         INIT_COMPLETION(dev->power.completion);
 885
 886         if (pm_async_enabled && dev->power.async_suspend) {
 887                 get_device(dev);
 888                 async_schedule(async_suspend, dev);
 889                 return 0;
 890         }
 891
 892         return __device_suspend(dev, pm_transition, false);
 893 }
 894
 895 /**
 896  * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
 897  * @state: PM transition of the system being carried out.
 898  */
 899 int dpm_suspend(pm_message_t state)
 900 {
 901         ktime_t starttime = ktime_get();
 902         int error = 0;
 903
 904         might_sleep();
 905
 906         mutex_lock(&dpm_list_mtx);
 907         pm_transition = state;
 908         async_error = 0;
 909         while (!list_empty(&dpm_prepared_list)) {
 910                 struct device *dev = to_device(dpm_prepared_list.prev);
 911
 912                 get_device(dev);
 913                 mutex_unlock(&dpm_list_mtx);
 914
 915                 error = device_suspend(dev);
 916
 917                 mutex_lock(&dpm_list_mtx);
 918                 if (error) {
 919                         pm_dev_err(dev, state, "", error);
 920                         dpm_save_failed_dev(dev_name(dev));
 921                         put_device(dev);
 922                         break;
 923                 }
 924                 if (!list_empty(&dev->power.entry))
 925                         list_move(&dev->power.entry, &dpm_suspended_list);
 926                 put_device(dev);
 927                 if (async_error)
 928                         break;
 929         }
 930         mutex_unlock(&dpm_list_mtx);
 931         async_synchronize_full();
 932         if (!error)
 933                 error = async_error;
 934         if (error) {
 935                 suspend_stats.failed_suspend++;
 936                 dpm_save_failed_step(SUSPEND_SUSPEND);
 937         } else
 938                 dpm_show_time(starttime, state, NULL);
 939         return error;
 940 }
 941
 942 /**
 943  * device_prepare - Prepare a device for system power transition.
 944  * @dev: Device to handle.
 945  * @state: PM transition of the system being carried out.
 946  *
 947  * Execute the ->prepare() callback(s) for given device.  No new children of the
 948  * device may be registered after this function has returned.
 949  */
 950 static int device_prepare(struct device *dev, pm_message_t state)
 951 {
 952         int error = 0;
 953
 954         device_lock(dev);
 955
 956         dev->power.wakeup_path = device_may_wakeup(dev);
 957
 958         if (dev->pm_domain) {
 959                 pm_dev_dbg(dev, state, "preparing power domain ");
 960                 if (dev->pm_domain->ops.prepare)
 961                         error = dev->pm_domain->ops.prepare(dev);
 962                 suspend_report_result(dev->pm_domain->ops.prepare, error);
 963         } else if (dev->type && dev->type->pm) {
 964                 pm_dev_dbg(dev, state, "preparing type ");
 965                 if (dev->type->pm->prepare)
 966                         error = dev->type->pm->prepare(dev);
 967                 suspend_report_result(dev->type->pm->prepare, error);
 968         } else if (dev->class && dev->class->pm) {
 969                 pm_dev_dbg(dev, state, "preparing class ");
 970                 if (dev->class->pm->prepare)
 971                         error = dev->class->pm->prepare(dev);
 972                 suspend_report_result(dev->class->pm->prepare, error);
 973         } else if (dev->bus && dev->bus->pm) {
 974                 pm_dev_dbg(dev, state, "preparing ");
 975                 if (dev->bus->pm->prepare)
 976                         error = dev->bus->pm->prepare(dev);
 977                 suspend_report_result(dev->bus->pm->prepare, error);
 978         }
 979
 980         device_unlock(dev);
 981
 982         return error;
 983 }
 984
 985 /**
 986  * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
 987  * @state: PM transition of the system being carried out.
 988  *
 989  * Execute the ->prepare() callback(s) for all devices.
 990  */
 991 int dpm_prepare(pm_message_t state)
 992 {
 993         int error = 0;
 994
 995         might_sleep();
 996
 997         mutex_lock(&dpm_list_mtx);
 998         while (!list_empty(&dpm_list)) {
 999                 struct device *dev = to_device(dpm_list.next);
1000
1001                 get_device(dev);
1002                 mutex_unlock(&dpm_list_mtx);
1003
1004                 error = device_prepare(dev, state);
1005
1006                 mutex_lock(&dpm_list_mtx);
1007                 if (error) {
1008                         if (error == -EAGAIN) {
1009                                 put_device(dev);
1010                                 error = 0;
1011                                 continue;
1012                         }
1013                         printk(KERN_INFO "PM: Device %s not prepared "
1014                                 "for power transition: code %d\n",
1015                                 dev_name(dev), error);
1016                         put_device(dev);
1017                         break;
1018                 }
1019                 dev->power.is_prepared = true;
1020                 if (!list_empty(&dev->power.entry))
1021                         list_move_tail(&dev->power.entry, &dpm_prepared_list);
1022                 put_device(dev);
1023         }
1024         mutex_unlock(&dpm_list_mtx);
1025         return error;
1026 }
1027
1028 /**
1029  * dpm_suspend_start - Prepare devices for PM transition and suspend them.
1030  * @state: PM transition of the system being carried out.
1031  *
1032  * Prepare all non-sysdev devices for system PM transition and execute "suspend"
1033  * callbacks for them.
1034  */
1035 int dpm_suspend_start(pm_message_t state)
1036 {
1037         int error;
1038
1039         error = dpm_prepare(state);
1040         if (error) {
1041                 suspend_stats.failed_prepare++;
1042                 dpm_save_failed_step(SUSPEND_PREPARE);
1043         } else
1044                 error = dpm_suspend(state);
1045         return error;
1046 }
1047 EXPORT_SYMBOL_GPL(dpm_suspend_start);
1048
1049 void __suspend_report_result(const char *function, void *fn, int ret)
1050 {
1051         if (ret)
1052                 printk(KERN_ERR "%s(): %pF returns %d\n", function, fn, ret);
1053 }
1054 EXPORT_SYMBOL_GPL(__suspend_report_result);
1055
1056 /**
1057  * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
1058  * @dev: Device to wait for.
1059  * @subordinate: Device that needs to wait for @dev.
1060  */
1061 int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
1062 {
1063         dpm_wait(dev, subordinate->power.async_suspend);
1064         return async_error;
1065 }
1066 EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);