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