drivers/base/power/wakeup.c

   1 /*
   2  * drivers/base/power/wakeup.c - System wakeup events framework
   3  *
   4  * Copyright (c) 2010 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
   5  *
   6  * This file is released under the GPLv2.
   7  */
   8
   9 #include <linux/device.h>
  10 #include <linux/slab.h>
  11 #include <linux/sched.h>
  12 #include <linux/capability.h>
  13 #include <linux/export.h>
  14 #include <linux/suspend.h>
  15 #include <linux/seq_file.h>
  16 #include <linux/debugfs.h>
  17 #include <linux/pm_wakeirq.h>
  18 #include <trace/events/power.h>
  19
  20 #include "power.h"
  21
  22 /*
  23  * If set, the suspend/hibernate code will abort transitions to a sleep state
  24  * if wakeup events are registered during or immediately before the transition.
  25  */
  26 bool events_check_enabled __read_mostly;
  27
  28 /* If set and the system is suspending, terminate the suspend. */
  29 static bool pm_abort_suspend __read_mostly;
  30
  31 /*
  32  * Combined counters of registered wakeup events and wakeup events in progress.
  33  * They need to be modified together atomically, so it's better to use one
  34  * atomic variable to hold them both.
  35  */
  36 static atomic_t combined_event_count = ATOMIC_INIT(0);
  37
  38 #define IN_PROGRESS_BITS        (sizeof(int) * 4)
  39 #define MAX_IN_PROGRESS         ((1 << IN_PROGRESS_BITS) - 1)
  40
  41 static void split_counters(unsigned int *cnt, unsigned int *inpr)
  42 {
  43         unsigned int comb = atomic_read(&combined_event_count);
  44
  45         *cnt = (comb >> IN_PROGRESS_BITS);
  46         *inpr = comb & MAX_IN_PROGRESS;
  47 }
  48
  49 /* A preserved old value of the events counter. */
  50 static unsigned int saved_count;
  51
  52 static DEFINE_SPINLOCK(events_lock);
  53
  54 static void pm_wakeup_timer_fn(unsigned long data);
  55
  56 static LIST_HEAD(wakeup_sources);
  57
  58 static DECLARE_WAIT_QUEUE_HEAD(wakeup_count_wait_queue);
  59
  60 /**
  61  * wakeup_source_prepare - Prepare a new wakeup source for initialization.
  62  * @ws: Wakeup source to prepare.
  63  * @name: Pointer to the name of the new wakeup source.
  64  *
  65  * Callers must ensure that the @name string won't be freed when @ws is still in
  66  * use.
  67  */
  68 void wakeup_source_prepare(struct wakeup_source *ws, const char *name)
  69 {
  70         if (ws) {
  71                 memset(ws, 0, sizeof(*ws));
  72                 ws->name = name;
  73         }
  74 }
  75 EXPORT_SYMBOL_GPL(wakeup_source_prepare);
  76
  77 /**
  78  * wakeup_source_create - Create a struct wakeup_source object.
  79  * @name: Name of the new wakeup source.
  80  */
  81 struct wakeup_source *wakeup_source_create(const char *name)
  82 {
  83         struct wakeup_source *ws;
  84
  85         ws = kmalloc(sizeof(*ws), GFP_KERNEL);
  86         if (!ws)
  87                 return NULL;
  88
  89         wakeup_source_prepare(ws, name ? kstrdup(name, GFP_KERNEL) : NULL);
  90         return ws;
  91 }
  92 EXPORT_SYMBOL_GPL(wakeup_source_create);
  93
  94 /**
  95  * wakeup_source_drop - Prepare a struct wakeup_source object for destruction.
  96  * @ws: Wakeup source to prepare for destruction.
  97  *
  98  * Callers must ensure that __pm_stay_awake() or __pm_wakeup_event() will never
  99  * be run in parallel with this function for the same wakeup source object.
 100  */
 101 void wakeup_source_drop(struct wakeup_source *ws)
 102 {
 103         if (!ws)
 104                 return;
 105
 106         del_timer_sync(&ws->timer);
 107         __pm_relax(ws);
 108 }
 109 EXPORT_SYMBOL_GPL(wakeup_source_drop);
 110
 111 /**
 112  * wakeup_source_destroy - Destroy a struct wakeup_source object.
 113  * @ws: Wakeup source to destroy.
 114  *
 115  * Use only for wakeup source objects created with wakeup_source_create().
 116  */
 117 void wakeup_source_destroy(struct wakeup_source *ws)
 118 {
 119         if (!ws)
 120                 return;
 121
 122         wakeup_source_drop(ws);
 123         kfree(ws->name);
 124         kfree(ws);
 125 }
 126 EXPORT_SYMBOL_GPL(wakeup_source_destroy);
 127
 128 /**
 129  * wakeup_source_add - Add given object to the list of wakeup sources.
 130  * @ws: Wakeup source object to add to the list.
 131  */
 132 void wakeup_source_add(struct wakeup_source *ws)
 133 {
 134         unsigned long flags;
 135
 136         if (WARN_ON(!ws))
 137                 return;
 138
 139         spin_lock_init(&ws->lock);
 140         setup_timer(&ws->timer, pm_wakeup_timer_fn, (unsigned long)ws);
 141         ws->active = false;
 142         ws->last_time = ktime_get();
 143
 144         spin_lock_irqsave(&events_lock, flags);
 145         list_add_rcu(&ws->entry, &wakeup_sources);
 146         spin_unlock_irqrestore(&events_lock, flags);
 147 }
 148 EXPORT_SYMBOL_GPL(wakeup_source_add);
 149
 150 /**
 151  * wakeup_source_remove - Remove given object from the wakeup sources list.
 152  * @ws: Wakeup source object to remove from the list.
 153  */
 154 void wakeup_source_remove(struct wakeup_source *ws)
 155 {
 156         unsigned long flags;
 157
 158         if (WARN_ON(!ws))
 159                 return;
 160
 161         spin_lock_irqsave(&events_lock, flags);
 162         list_del_rcu(&ws->entry);
 163         spin_unlock_irqrestore(&events_lock, flags);
 164         synchronize_rcu();
 165 }
 166 EXPORT_SYMBOL_GPL(wakeup_source_remove);
 167
 168 /**
 169  * wakeup_source_register - Create wakeup source and add it to the list.
 170  * @name: Name of the wakeup source to register.
 171  */
 172 struct wakeup_source *wakeup_source_register(const char *name)
 173 {
 174         struct wakeup_source *ws;
 175
 176         ws = wakeup_source_create(name);
 177         if (ws)
 178                 wakeup_source_add(ws);
 179
 180         return ws;
 181 }
 182 EXPORT_SYMBOL_GPL(wakeup_source_register);
 183
 184 /**
 185  * wakeup_source_unregister - Remove wakeup source from the list and remove it.
 186  * @ws: Wakeup source object to unregister.
 187  */
 188 void wakeup_source_unregister(struct wakeup_source *ws)
 189 {
 190         if (ws) {
 191                 wakeup_source_remove(ws);
 192                 wakeup_source_destroy(ws);
 193         }
 194 }
 195 EXPORT_SYMBOL_GPL(wakeup_source_unregister);
 196
 197 /**
 198  * device_wakeup_attach - Attach a wakeup source object to a device object.
 199  * @dev: Device to handle.
 200  * @ws: Wakeup source object to attach to @dev.
 201  *
 202  * This causes @dev to be treated as a wakeup device.
 203  */
 204 static int device_wakeup_attach(struct device *dev, struct wakeup_source *ws)
 205 {
 206         spin_lock_irq(&dev->power.lock);
 207         if (dev->power.wakeup) {
 208                 spin_unlock_irq(&dev->power.lock);
 209                 return -EEXIST;
 210         }
 211         dev->power.wakeup = ws;
 212         spin_unlock_irq(&dev->power.lock);
 213         return 0;
 214 }
 215
 216 /**
 217  * device_wakeup_enable - Enable given device to be a wakeup source.
 218  * @dev: Device to handle.
 219  *
 220  * Create a wakeup source object, register it and attach it to @dev.
 221  */
 222 int device_wakeup_enable(struct device *dev)
 223 {
 224         struct wakeup_source *ws;
 225         int ret;
 226
 227         if (!dev || !dev->power.can_wakeup)
 228                 return -EINVAL;
 229
 230         ws = wakeup_source_register(dev_name(dev));
 231         if (!ws)
 232                 return -ENOMEM;
 233
 234         ret = device_wakeup_attach(dev, ws);
 235         if (ret)
 236                 wakeup_source_unregister(ws);
 237
 238         return ret;
 239 }
 240 EXPORT_SYMBOL_GPL(device_wakeup_enable);
 241
 242 /**
 243  * device_wakeup_attach_irq - Attach a wakeirq to a wakeup source
 244  * @dev: Device to handle
 245  * @wakeirq: Device specific wakeirq entry
 246  *
 247  * Attach a device wakeirq to the wakeup source so the device
 248  * wake IRQ can be configured automatically for suspend and
 249  * resume.
 250  */
 251 int device_wakeup_attach_irq(struct device *dev,
 252                              struct wake_irq *wakeirq)
 253 {
 254         struct wakeup_source *ws;
 255         int ret = 0;
 256
 257         spin_lock_irq(&dev->power.lock);
 258         ws = dev->power.wakeup;
 259         if (!ws) {
 260                 dev_err(dev, "forgot to call call device_init_wakeup?\n");
 261                 ret = -EINVAL;
 262                 goto unlock;
 263         }
 264
 265         if (ws->wakeirq) {
 266                 ret = -EEXIST;
 267                 goto unlock;
 268         }
 269
 270         ws->wakeirq = wakeirq;
 271
 272 unlock:
 273         spin_unlock_irq(&dev->power.lock);
 274
 275         return ret;
 276 }
 277
 278 /**
 279  * device_wakeup_detach_irq - Detach a wakeirq from a wakeup source
 280  * @dev: Device to handle
 281  *
 282  * Removes a device wakeirq from the wakeup source.
 283  */
 284 void device_wakeup_detach_irq(struct device *dev)
 285 {
 286         struct wakeup_source *ws;
 287
 288         spin_lock_irq(&dev->power.lock);
 289         ws = dev->power.wakeup;
 290         if (!ws)
 291                 goto unlock;
 292
 293         ws->wakeirq = NULL;
 294
 295 unlock:
 296         spin_unlock_irq(&dev->power.lock);
 297 }
 298
 299 /**
 300  * device_wakeup_arm_wake_irqs(void)
 301  *
 302  * Itereates over the list of device wakeirqs to arm them.
 303  */
 304 void device_wakeup_arm_wake_irqs(void)
 305 {
 306         struct wakeup_source *ws;
 307
 308         rcu_read_lock();
 309         list_for_each_entry_rcu(ws, &wakeup_sources, entry) {
 310                 if (ws->wakeirq)
 311                         dev_pm_arm_wake_irq(ws->wakeirq);
 312         }
 313         rcu_read_unlock();
 314 }
 315
 316 /**
 317  * device_wakeup_disarm_wake_irqs(void)
 318  *
 319  * Itereates over the list of device wakeirqs to disarm them.
 320  */
 321 void device_wakeup_disarm_wake_irqs(void)
 322 {
 323         struct wakeup_source *ws;
 324
 325         rcu_read_lock();
 326         list_for_each_entry_rcu(ws, &wakeup_sources, entry) {
 327                 if (ws->wakeirq)
 328                         dev_pm_disarm_wake_irq(ws->wakeirq);
 329         }
 330         rcu_read_unlock();
 331 }
 332
 333 /**
 334  * device_wakeup_detach - Detach a device's wakeup source object from it.
 335  * @dev: Device to detach the wakeup source object from.
 336  *
 337  * After it returns, @dev will not be treated as a wakeup device any more.
 338  */
 339 static struct wakeup_source *device_wakeup_detach(struct device *dev)
 340 {
 341         struct wakeup_source *ws;
 342
 343         spin_lock_irq(&dev->power.lock);
 344         ws = dev->power.wakeup;
 345         dev->power.wakeup = NULL;
 346         spin_unlock_irq(&dev->power.lock);
 347         return ws;
 348 }
 349
 350 /**
 351  * device_wakeup_disable - Do not regard a device as a wakeup source any more.
 352  * @dev: Device to handle.
 353  *
 354  * Detach the @dev's wakeup source object from it, unregister this wakeup source
 355  * object and destroy it.
 356  */
 357 int device_wakeup_disable(struct device *dev)
 358 {
 359         struct wakeup_source *ws;
 360
 361         if (!dev || !dev->power.can_wakeup)
 362                 return -EINVAL;
 363
 364         ws = device_wakeup_detach(dev);
 365         if (ws)
 366                 wakeup_source_unregister(ws);
 367
 368         return 0;
 369 }
 370 EXPORT_SYMBOL_GPL(device_wakeup_disable);
 371
 372 /**
 373  * device_set_wakeup_capable - Set/reset device wakeup capability flag.
 374  * @dev: Device to handle.
 375  * @capable: Whether or not @dev is capable of waking up the system from sleep.
 376  *
 377  * If @capable is set, set the @dev's power.can_wakeup flag and add its
 378  * wakeup-related attributes to sysfs.  Otherwise, unset the @dev's
 379  * power.can_wakeup flag and remove its wakeup-related attributes from sysfs.
 380  *
 381  * This function may sleep and it can't be called from any context where
 382  * sleeping is not allowed.
 383  */
 384 void device_set_wakeup_capable(struct device *dev, bool capable)
 385 {
 386         if (!!dev->power.can_wakeup == !!capable)
 387                 return;
 388
 389         if (device_is_registered(dev) && !list_empty(&dev->power.entry)) {
 390                 if (capable) {
 391                         if (wakeup_sysfs_add(dev))
 392                                 return;
 393                 } else {
 394                         wakeup_sysfs_remove(dev);
 395                 }
 396         }
 397         dev->power.can_wakeup = capable;
 398 }
 399 EXPORT_SYMBOL_GPL(device_set_wakeup_capable);
 400
 401 /**
 402  * device_init_wakeup - Device wakeup initialization.
 403  * @dev: Device to handle.
 404  * @enable: Whether or not to enable @dev as a wakeup device.
 405  *
 406  * By default, most devices should leave wakeup disabled.  The exceptions are
 407  * devices that everyone expects to be wakeup sources: keyboards, power buttons,
 408  * possibly network interfaces, etc.  Also, devices that don't generate their
 409  * own wakeup requests but merely forward requests from one bus to another
 410  * (like PCI bridges) should have wakeup enabled by default.
 411  */
 412 int device_init_wakeup(struct device *dev, bool enable)
 413 {
 414         int ret = 0;
 415
 416         if (!dev)
 417                 return -EINVAL;
 418
 419         if (enable) {
 420                 device_set_wakeup_capable(dev, true);
 421                 ret = device_wakeup_enable(dev);
 422         } else {
 423                 if (dev->power.can_wakeup)
 424                         device_wakeup_disable(dev);
 425
 426                 device_set_wakeup_capable(dev, false);
 427         }
 428
 429         return ret;
 430 }
 431 EXPORT_SYMBOL_GPL(device_init_wakeup);
 432
 433 /**
 434  * device_set_wakeup_enable - Enable or disable a device to wake up the system.
 435  * @dev: Device to handle.
 436  */
 437 int device_set_wakeup_enable(struct device *dev, bool enable)
 438 {
 439         if (!dev || !dev->power.can_wakeup)
 440                 return -EINVAL;
 441
 442         return enable ? device_wakeup_enable(dev) : device_wakeup_disable(dev);
 443 }
 444 EXPORT_SYMBOL_GPL(device_set_wakeup_enable);
 445
 446 /*
 447  * The functions below use the observation that each wakeup event starts a
 448  * period in which the system should not be suspended.  The moment this period
 449  * will end depends on how the wakeup event is going to be processed after being
 450  * detected and all of the possible cases can be divided into two distinct
 451  * groups.
 452  *
 453  * First, a wakeup event may be detected by the same functional unit that will
 454  * carry out the entire processing of it and possibly will pass it to user space
 455  * for further processing.  In that case the functional unit that has detected
 456  * the event may later "close" the "no suspend" period associated with it
 457  * directly as soon as it has been dealt with.  The pair of pm_stay_awake() and
 458  * pm_relax(), balanced with each other, is supposed to be used in such
 459  * situations.
 460  *
 461  * Second, a wakeup event may be detected by one functional unit and processed
 462  * by another one.  In that case the unit that has detected it cannot really
 463  * "close" the "no suspend" period associated with it, unless it knows in
 464  * advance what's going to happen to the event during processing.  This
 465  * knowledge, however, may not be available to it, so it can simply specify time
 466  * to wait before the system can be suspended and pass it as the second
 467  * argument of pm_wakeup_event().
 468  *
 469  * It is valid to call pm_relax() after pm_wakeup_event(), in which case the
 470  * "no suspend" period will be ended either by the pm_relax(), or by the timer
 471  * function executed when the timer expires, whichever comes first.
 472  */
 473
 474 /**
 475  * wakup_source_activate - Mark given wakeup source as active.
 476  * @ws: Wakeup source to handle.
 477  *
 478  * Update the @ws' statistics and, if @ws has just been activated, notify the PM
 479  * core of the event by incrementing the counter of of wakeup events being
 480  * processed.
 481  */
 482 static void wakeup_source_activate(struct wakeup_source *ws)
 483 {
 484         unsigned int cec;
 485
 486         /*
 487          * active wakeup source should bring the system
 488          * out of PM_SUSPEND_FREEZE state
 489          */
 490         freeze_wake();
 491
 492         ws->active = true;
 493         ws->active_count++;
 494         ws->last_time = ktime_get();
 495         if (ws->autosleep_enabled)
 496                 ws->start_prevent_time = ws->last_time;
 497
 498         /* Increment the counter of events in progress. */
 499         cec = atomic_inc_return(&combined_event_count);
 500
 501         trace_wakeup_source_activate(ws->name, cec);
 502 }
 503
 504 /**
 505  * wakeup_source_report_event - Report wakeup event using the given source.
 506  * @ws: Wakeup source to report the event for.
 507  */
 508 static void wakeup_source_report_event(struct wakeup_source *ws)
 509 {
 510         ws->event_count++;
 511         /* This is racy, but the counter is approximate anyway. */
 512         if (events_check_enabled)
 513                 ws->wakeup_count++;
 514
 515         if (!ws->active)
 516                 wakeup_source_activate(ws);
 517 }
 518
 519 /**
 520  * __pm_stay_awake - Notify the PM core of a wakeup event.
 521  * @ws: Wakeup source object associated with the source of the event.
 522  *
 523  * It is safe to call this function from interrupt context.
 524  */
 525 void __pm_stay_awake(struct wakeup_source *ws)
 526 {
 527         unsigned long flags;
 528
 529         if (!ws)
 530                 return;
 531
 532         spin_lock_irqsave(&ws->lock, flags);
 533
 534         wakeup_source_report_event(ws);
 535         del_timer(&ws->timer);
 536         ws->timer_expires = 0;
 537
 538         spin_unlock_irqrestore(&ws->lock, flags);
 539 }
 540 EXPORT_SYMBOL_GPL(__pm_stay_awake);
 541
 542 /**
 543  * pm_stay_awake - Notify the PM core that a wakeup event is being processed.
 544  * @dev: Device the wakeup event is related to.
 545  *
 546  * Notify the PM core of a wakeup event (signaled by @dev) by calling
 547  * __pm_stay_awake for the @dev's wakeup source object.
 548  *
 549  * Call this function after detecting of a wakeup event if pm_relax() is going
 550  * to be called directly after processing the event (and possibly passing it to
 551  * user space for further processing).
 552  */
 553 void pm_stay_awake(struct device *dev)
 554 {
 555         unsigned long flags;
 556
 557         if (!dev)
 558                 return;
 559
 560         spin_lock_irqsave(&dev->power.lock, flags);
 561         __pm_stay_awake(dev->power.wakeup);
 562         spin_unlock_irqrestore(&dev->power.lock, flags);
 563 }
 564 EXPORT_SYMBOL_GPL(pm_stay_awake);
 565
 566 #ifdef CONFIG_PM_AUTOSLEEP
 567 static void update_prevent_sleep_time(struct wakeup_source *ws, ktime_t now)
 568 {
 569         ktime_t delta = ktime_sub(now, ws->start_prevent_time);
 570         ws->prevent_sleep_time = ktime_add(ws->prevent_sleep_time, delta);
 571 }
 572 #else
 573 static inline void update_prevent_sleep_time(struct wakeup_source *ws,
 574                                              ktime_t now) {}
 575 #endif
 576
 577 /**
 578  * wakup_source_deactivate - Mark given wakeup source as inactive.
 579  * @ws: Wakeup source to handle.
 580  *
 581  * Update the @ws' statistics and notify the PM core that the wakeup source has
 582  * become inactive by decrementing the counter of wakeup events being processed
 583  * and incrementing the counter of registered wakeup events.
 584  */
 585 static void wakeup_source_deactivate(struct wakeup_source *ws)
 586 {
 587         unsigned int cnt, inpr, cec;
 588         ktime_t duration;
 589         ktime_t now;
 590
 591         ws->relax_count++;
 592         /*
 593          * __pm_relax() may be called directly or from a timer function.
 594          * If it is called directly right after the timer function has been
 595          * started, but before the timer function calls __pm_relax(), it is
 596          * possible that __pm_stay_awake() will be called in the meantime and
 597          * will set ws->active.  Then, ws->active may be cleared immediately
 598          * by the __pm_relax() called from the timer function, but in such a
 599          * case ws->relax_count will be different from ws->active_count.
 600          */
 601         if (ws->relax_count != ws->active_count) {
 602                 ws->relax_count--;
 603                 return;
 604         }
 605
 606         ws->active = false;
 607
 608         now = ktime_get();
 609         duration = ktime_sub(now, ws->last_time);
 610         ws->total_time = ktime_add(ws->total_time, duration);
 611         if (ktime_to_ns(duration) > ktime_to_ns(ws->max_time))
 612                 ws->max_time = duration;
 613
 614         ws->last_time = now;
 615         del_timer(&ws->timer);
 616         ws->timer_expires = 0;
 617
 618         if (ws->autosleep_enabled)
 619                 update_prevent_sleep_time(ws, now);
 620
 621         /*
 622          * Increment the counter of registered wakeup events and decrement the
 623          * couter of wakeup events in progress simultaneously.
 624          */
 625         cec = atomic_add_return(MAX_IN_PROGRESS, &combined_event_count);
 626         trace_wakeup_source_deactivate(ws->name, cec);
 627
 628         split_counters(&cnt, &inpr);
 629         if (!inpr && waitqueue_active(&wakeup_count_wait_queue))
 630                 wake_up(&wakeup_count_wait_queue);
 631 }
 632
 633 /**
 634  * __pm_relax - Notify the PM core that processing of a wakeup event has ended.
 635  * @ws: Wakeup source object associated with the source of the event.
 636  *
 637  * Call this function for wakeup events whose processing started with calling
 638  * __pm_stay_awake().
 639  *
 640  * It is safe to call it from interrupt context.
 641  */
 642 void __pm_relax(struct wakeup_source *ws)
 643 {
 644         unsigned long flags;
 645
 646         if (!ws)
 647                 return;
 648
 649         spin_lock_irqsave(&ws->lock, flags);
 650         if (ws->active)
 651                 wakeup_source_deactivate(ws);
 652         spin_unlock_irqrestore(&ws->lock, flags);
 653 }
 654 EXPORT_SYMBOL_GPL(__pm_relax);
 655
 656 /**
 657  * pm_relax - Notify the PM core that processing of a wakeup event has ended.
 658  * @dev: Device that signaled the event.
 659  *
 660  * Execute __pm_relax() for the @dev's wakeup source object.
 661  */
 662 void pm_relax(struct device *dev)
 663 {
 664         unsigned long flags;
 665
 666         if (!dev)
 667                 return;
 668
 669         spin_lock_irqsave(&dev->power.lock, flags);
 670         __pm_relax(dev->power.wakeup);
 671         spin_unlock_irqrestore(&dev->power.lock, flags);
 672 }
 673 EXPORT_SYMBOL_GPL(pm_relax);
 674
 675 /**
 676  * pm_wakeup_timer_fn - Delayed finalization of a wakeup event.
 677  * @data: Address of the wakeup source object associated with the event source.
 678  *
 679  * Call wakeup_source_deactivate() for the wakeup source whose address is stored
 680  * in @data if it is currently active and its timer has not been canceled and
 681  * the expiration time of the timer is not in future.
 682  */
 683 static void pm_wakeup_timer_fn(unsigned long data)
 684 {
 685         struct wakeup_source *ws = (struct wakeup_source *)data;
 686         unsigned long flags;
 687
 688         spin_lock_irqsave(&ws->lock, flags);
 689
 690         if (ws->active && ws->timer_expires
 691             && time_after_eq(jiffies, ws->timer_expires)) {
 692                 wakeup_source_deactivate(ws);
 693                 ws->expire_count++;
 694         }
 695
 696         spin_unlock_irqrestore(&ws->lock, flags);
 697 }
 698
 699 /**
 700  * __pm_wakeup_event - Notify the PM core of a wakeup event.
 701  * @ws: Wakeup source object associated with the event source.
 702  * @msec: Anticipated event processing time (in milliseconds).
 703  *
 704  * Notify the PM core of a wakeup event whose source is @ws that will take
 705  * approximately @msec milliseconds to be processed by the kernel.  If @ws is
 706  * not active, activate it.  If @msec is nonzero, set up the @ws' timer to
 707  * execute pm_wakeup_timer_fn() in future.
 708  *
 709  * It is safe to call this function from interrupt context.
 710  */
 711 void __pm_wakeup_event(struct wakeup_source *ws, unsigned int msec)
 712 {
 713         unsigned long flags;
 714         unsigned long expires;
 715
 716         if (!ws)
 717                 return;
 718
 719         spin_lock_irqsave(&ws->lock, flags);
 720
 721         wakeup_source_report_event(ws);
 722
 723         if (!msec) {
 724                 wakeup_source_deactivate(ws);
 725                 goto unlock;
 726         }
 727
 728         expires = jiffies + msecs_to_jiffies(msec);
 729         if (!expires)
 730                 expires = 1;
 731
 732         if (!ws->timer_expires || time_after(expires, ws->timer_expires)) {
 733                 mod_timer(&ws->timer, expires);
 734                 ws->timer_expires = expires;
 735         }
 736
 737  unlock:
 738         spin_unlock_irqrestore(&ws->lock, flags);
 739 }
 740 EXPORT_SYMBOL_GPL(__pm_wakeup_event);
 741
 742
 743 /**
 744  * pm_wakeup_event - Notify the PM core of a wakeup event.
 745  * @dev: Device the wakeup event is related to.
 746  * @msec: Anticipated event processing time (in milliseconds).
 747  *
 748  * Call __pm_wakeup_event() for the @dev's wakeup source object.
 749  */
 750 void pm_wakeup_event(struct device *dev, unsigned int msec)
 751 {
 752         unsigned long flags;
 753
 754         if (!dev)
 755                 return;
 756
 757         spin_lock_irqsave(&dev->power.lock, flags);
 758         __pm_wakeup_event(dev->power.wakeup, msec);
 759         spin_unlock_irqrestore(&dev->power.lock, flags);
 760 }
 761 EXPORT_SYMBOL_GPL(pm_wakeup_event);
 762
 763 void pm_print_active_wakeup_sources(void)
 764 {
 765         struct wakeup_source *ws;
 766         int active = 0;
 767         struct wakeup_source *last_activity_ws = NULL;
 768
 769         rcu_read_lock();
 770         list_for_each_entry_rcu(ws, &wakeup_sources, entry) {
 771                 if (ws->active) {
 772                         pr_info("active wakeup source: %s\n", ws->name);
 773                         active = 1;
 774                 } else if (!active &&
 775                            (!last_activity_ws ||
 776                             ktime_to_ns(ws->last_time) >
 777                             ktime_to_ns(last_activity_ws->last_time))) {
 778                         last_activity_ws = ws;
 779                 }
 780         }
 781
 782         if (!active && last_activity_ws)
 783                 pr_info("last active wakeup source: %s\n",
 784                         last_activity_ws->name);
 785         rcu_read_unlock();
 786 }
 787 EXPORT_SYMBOL_GPL(pm_print_active_wakeup_sources);
 788
 789 /**
 790  * pm_wakeup_pending - Check if power transition in progress should be aborted.
 791  *
 792  * Compare the current number of registered wakeup events with its preserved
 793  * value from the past and return true if new wakeup events have been registered
 794  * since the old value was stored.  Also return true if the current number of
 795  * wakeup events being processed is different from zero.
 796  */
 797 bool pm_wakeup_pending(void)
 798 {
 799         unsigned long flags;
 800         bool ret = false;
 801
 802         spin_lock_irqsave(&events_lock, flags);
 803         if (events_check_enabled) {
 804                 unsigned int cnt, inpr;
 805
 806                 split_counters(&cnt, &inpr);
 807                 ret = (cnt != saved_count || inpr > 0);
 808                 events_check_enabled = !ret;
 809         }
 810         spin_unlock_irqrestore(&events_lock, flags);
 811
 812         if (ret) {
 813                 pr_info("PM: Wakeup pending, aborting suspend\n");
 814                 pm_print_active_wakeup_sources();
 815         }
 816
 817         return ret || pm_abort_suspend;
 818 }
 819
 820 void pm_system_wakeup(void)
 821 {
 822         pm_abort_suspend = true;
 823         freeze_wake();
 824 }
 825 EXPORT_SYMBOL_GPL(pm_system_wakeup);
 826
 827 void pm_wakeup_clear(void)
 828 {
 829         pm_abort_suspend = false;
 830 }
 831
 832 /**
 833  * pm_get_wakeup_count - Read the number of registered wakeup events.
 834  * @count: Address to store the value at.
 835  * @block: Whether or not to block.
 836  *
 837  * Store the number of registered wakeup events at the address in @count.  If
 838  * @block is set, block until the current number of wakeup events being
 839  * processed is zero.
 840  *
 841  * Return 'false' if the current number of wakeup events being processed is
 842  * nonzero.  Otherwise return 'true'.
 843  */
 844 bool pm_get_wakeup_count(unsigned int *count, bool block)
 845 {
 846         unsigned int cnt, inpr;
 847
 848         if (block) {
 849                 DEFINE_WAIT(wait);
 850
 851                 for (;;) {
 852                         prepare_to_wait(&wakeup_count_wait_queue, &wait,
 853                                         TASK_INTERRUPTIBLE);
 854                         split_counters(&cnt, &inpr);
 855                         if (inpr == 0 || signal_pending(current))
 856                                 break;
 857
 858                         schedule();
 859                 }
 860                 finish_wait(&wakeup_count_wait_queue, &wait);
 861         }
 862
 863         split_counters(&cnt, &inpr);
 864         *count = cnt;
 865         return !inpr;
 866 }
 867
 868 /**
 869  * pm_save_wakeup_count - Save the current number of registered wakeup events.
 870  * @count: Value to compare with the current number of registered wakeup events.
 871  *
 872  * If @count is equal to the current number of registered wakeup events and the
 873  * current number of wakeup events being processed is zero, store @count as the
 874  * old number of registered wakeup events for pm_check_wakeup_events(), enable
 875  * wakeup events detection and return 'true'.  Otherwise disable wakeup events
 876  * detection and return 'false'.
 877  */
 878 bool pm_save_wakeup_count(unsigned int count)
 879 {
 880         unsigned int cnt, inpr;
 881         unsigned long flags;
 882
 883         events_check_enabled = false;
 884         spin_lock_irqsave(&events_lock, flags);
 885         split_counters(&cnt, &inpr);
 886         if (cnt == count && inpr == 0) {
 887                 saved_count = count;
 888                 events_check_enabled = true;
 889         }
 890         spin_unlock_irqrestore(&events_lock, flags);
 891         return events_check_enabled;
 892 }
 893
 894 #ifdef CONFIG_PM_AUTOSLEEP
 895 /**
 896  * pm_wakep_autosleep_enabled - Modify autosleep_enabled for all wakeup sources.
 897  * @enabled: Whether to set or to clear the autosleep_enabled flags.
 898  */
 899 void pm_wakep_autosleep_enabled(bool set)
 900 {
 901         struct wakeup_source *ws;
 902         ktime_t now = ktime_get();
 903
 904         rcu_read_lock();
 905         list_for_each_entry_rcu(ws, &wakeup_sources, entry) {
 906                 spin_lock_irq(&ws->lock);
 907                 if (ws->autosleep_enabled != set) {
 908                         ws->autosleep_enabled = set;
 909                         if (ws->active) {
 910                                 if (set)
 911                                         ws->start_prevent_time = now;
 912                                 else
 913                                         update_prevent_sleep_time(ws, now);
 914                         }
 915                 }
 916                 spin_unlock_irq(&ws->lock);
 917         }
 918         rcu_read_unlock();
 919 }
 920 #endif /* CONFIG_PM_AUTOSLEEP */
 921
 922 static struct dentry *wakeup_sources_stats_dentry;
 923
 924 /**
 925  * print_wakeup_source_stats - Print wakeup source statistics information.
 926  * @m: seq_file to print the statistics into.
 927  * @ws: Wakeup source object to print the statistics for.
 928  */
 929 static int print_wakeup_source_stats(struct seq_file *m,
 930                                      struct wakeup_source *ws)
 931 {
 932         unsigned long flags;
 933         ktime_t total_time;
 934         ktime_t max_time;
 935         unsigned long active_count;
 936         ktime_t active_time;
 937         ktime_t prevent_sleep_time;
 938
 939         spin_lock_irqsave(&ws->lock, flags);
 940
 941         total_time = ws->total_time;
 942         max_time = ws->max_time;
 943         prevent_sleep_time = ws->prevent_sleep_time;
 944         active_count = ws->active_count;
 945         if (ws->active) {
 946                 ktime_t now = ktime_get();
 947
 948                 active_time = ktime_sub(now, ws->last_time);
 949                 total_time = ktime_add(total_time, active_time);
 950                 if (active_time.tv64 > max_time.tv64)
 951                         max_time = active_time;
 952
 953                 if (ws->autosleep_enabled)
 954                         prevent_sleep_time = ktime_add(prevent_sleep_time,
 955                                 ktime_sub(now, ws->start_prevent_time));
 956         } else {
 957                 active_time = ktime_set(0, 0);
 958         }
 959
 960         seq_printf(m, "%-12s\t%lu\t\t%lu\t\t%lu\t\t%lu\t\t%lld\t\t%lld\t\t%lld\t\t%lld\t\t%lld\n",
 961                    ws->name, active_count, ws->event_count,
 962                    ws->wakeup_count, ws->expire_count,
 963                    ktime_to_ms(active_time), ktime_to_ms(total_time),
 964                    ktime_to_ms(max_time), ktime_to_ms(ws->last_time),
 965                    ktime_to_ms(prevent_sleep_time));
 966
 967         spin_unlock_irqrestore(&ws->lock, flags);
 968
 969         return 0;
 970 }
 971
 972 /**
 973  * wakeup_sources_stats_show - Print wakeup sources statistics information.
 974  * @m: seq_file to print the statistics into.
 975  */
 976 static int wakeup_sources_stats_show(struct seq_file *m, void *unused)
 977 {
 978         struct wakeup_source *ws;
 979
 980         seq_puts(m, "name\t\tactive_count\tevent_count\twakeup_count\t"
 981                 "expire_count\tactive_since\ttotal_time\tmax_time\t"
 982                 "last_change\tprevent_suspend_time\n");
 983
 984         rcu_read_lock();
 985         list_for_each_entry_rcu(ws, &wakeup_sources, entry)
 986                 print_wakeup_source_stats(m, ws);
 987         rcu_read_unlock();
 988
 989         return 0;
 990 }
 991
 992 static int wakeup_sources_stats_open(struct inode *inode, struct file *file)
 993 {
 994         return single_open(file, wakeup_sources_stats_show, NULL);
 995 }
 996
 997 static const struct file_operations wakeup_sources_stats_fops = {
 998         .owner = THIS_MODULE,
 999         .open = wakeup_sources_stats_open,
1000         .read = seq_read,
1001         .llseek = seq_lseek,
1002         .release = single_release,
1003 };
1004
1005 static int __init wakeup_sources_debugfs_init(void)
1006 {
1007         wakeup_sources_stats_dentry = debugfs_create_file("wakeup_sources",
1008                         S_IRUGO, NULL, NULL, &wakeup_sources_stats_fops);
1009         return 0;
1010 }
1011
1012 postcore_initcall(wakeup_sources_debugfs_init);