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/signal.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 /* First wakeup IRQ seen by the kernel in the last cycle. */
  29 unsigned int pm_wakeup_irq __read_mostly;
  30
  31 /* If greater than 0 and the system is suspending, terminate the suspend. */
  32 static atomic_t pm_abort_suspend __read_mostly;
  33
  34 /*
  35  * Combined counters of registered wakeup events and wakeup events in progress.
  36  * They need to be modified together atomically, so it's better to use one
  37  * atomic variable to hold them both.
  38  */
  39 static atomic_t combined_event_count = ATOMIC_INIT(0);
  40
  41 #define IN_PROGRESS_BITS        (sizeof(int) * 4)
  42 #define MAX_IN_PROGRESS         ((1 << IN_PROGRESS_BITS) - 1)
  43
  44 static void split_counters(unsigned int *cnt, unsigned int *inpr)
  45 {
  46         unsigned int comb = atomic_read(&combined_event_count);
  47
  48         *cnt = (comb >> IN_PROGRESS_BITS);
  49         *inpr = comb & MAX_IN_PROGRESS;
  50 }
  51
  52 /* A preserved old value of the events counter. */
  53 static unsigned int saved_count;
  54
  55 static DEFINE_SPINLOCK(events_lock);
  56
  57 static void pm_wakeup_timer_fn(unsigned long data);
  58
  59 static LIST_HEAD(wakeup_sources);
  60
  61 static DECLARE_WAIT_QUEUE_HEAD(wakeup_count_wait_queue);
  62
  63 DEFINE_STATIC_SRCU(wakeup_srcu);
  64
  65 static struct wakeup_source deleted_ws = {
  66         .name = "deleted",
  67         .lock =  __SPIN_LOCK_UNLOCKED(deleted_ws.lock),
  68 };
  69
  70 /**
  71  * wakeup_source_prepare - Prepare a new wakeup source for initialization.
  72  * @ws: Wakeup source to prepare.
  73  * @name: Pointer to the name of the new wakeup source.
  74  *
  75  * Callers must ensure that the @name string won't be freed when @ws is still in
  76  * use.
  77  */
  78 void wakeup_source_prepare(struct wakeup_source *ws, const char *name)
  79 {
  80         if (ws) {
  81                 memset(ws, 0, sizeof(*ws));
  82                 ws->name = name;
  83         }
  84 }
  85 EXPORT_SYMBOL_GPL(wakeup_source_prepare);
  86
  87 /**
  88  * wakeup_source_create - Create a struct wakeup_source object.
  89  * @name: Name of the new wakeup source.
  90  */
  91 struct wakeup_source *wakeup_source_create(const char *name)
  92 {
  93         struct wakeup_source *ws;
  94
  95         ws = kmalloc(sizeof(*ws), GFP_KERNEL);
  96         if (!ws)
  97                 return NULL;
  98
  99         wakeup_source_prepare(ws, name ? kstrdup_const(name, GFP_KERNEL) : NULL);
 100         return ws;
 101 }
 102 EXPORT_SYMBOL_GPL(wakeup_source_create);
 103
 104 /**
 105  * wakeup_source_drop - Prepare a struct wakeup_source object for destruction.
 106  * @ws: Wakeup source to prepare for destruction.
 107  *
 108  * Callers must ensure that __pm_stay_awake() or __pm_wakeup_event() will never
 109  * be run in parallel with this function for the same wakeup source object.
 110  */
 111 void wakeup_source_drop(struct wakeup_source *ws)
 112 {
 113         if (!ws)
 114                 return;
 115
 116         del_timer_sync(&ws->timer);
 117         __pm_relax(ws);
 118 }
 119 EXPORT_SYMBOL_GPL(wakeup_source_drop);
 120
 121 /*
 122  * Record wakeup_source statistics being deleted into a dummy wakeup_source.
 123  */
 124 static void wakeup_source_record(struct wakeup_source *ws)
 125 {
 126         unsigned long flags;
 127
 128         spin_lock_irqsave(&deleted_ws.lock, flags);
 129
 130         if (ws->event_count) {
 131                 deleted_ws.total_time =
 132                         ktime_add(deleted_ws.total_time, ws->total_time);
 133                 deleted_ws.prevent_sleep_time =
 134                         ktime_add(deleted_ws.prevent_sleep_time,
 135                                   ws->prevent_sleep_time);
 136                 deleted_ws.max_time =
 137                         ktime_compare(deleted_ws.max_time, ws->max_time) > 0 ?
 138                                 deleted_ws.max_time : ws->max_time;
 139                 deleted_ws.event_count += ws->event_count;
 140                 deleted_ws.active_count += ws->active_count;
 141                 deleted_ws.relax_count += ws->relax_count;
 142                 deleted_ws.expire_count += ws->expire_count;
 143                 deleted_ws.wakeup_count += ws->wakeup_count;
 144         }
 145
 146         spin_unlock_irqrestore(&deleted_ws.lock, flags);
 147 }
 148
 149 /**
 150  * wakeup_source_destroy - Destroy a struct wakeup_source object.
 151  * @ws: Wakeup source to destroy.
 152  *
 153  * Use only for wakeup source objects created with wakeup_source_create().
 154  */
 155 void wakeup_source_destroy(struct wakeup_source *ws)
 156 {
 157         if (!ws)
 158                 return;
 159
 160         wakeup_source_drop(ws);
 161         wakeup_source_record(ws);
 162         kfree_const(ws->name);
 163         kfree(ws);
 164 }
 165 EXPORT_SYMBOL_GPL(wakeup_source_destroy);
 166
 167 /**
 168  * wakeup_source_add - Add given object to the list of wakeup sources.
 169  * @ws: Wakeup source object to add to the list.
 170  */
 171 void wakeup_source_add(struct wakeup_source *ws)
 172 {
 173         unsigned long flags;
 174
 175         if (WARN_ON(!ws))
 176                 return;
 177
 178         spin_lock_init(&ws->lock);
 179         setup_timer(&ws->timer, pm_wakeup_timer_fn, (unsigned long)ws);
 180         ws->active = false;
 181         ws->last_time = ktime_get();
 182
 183         spin_lock_irqsave(&events_lock, flags);
 184         list_add_rcu(&ws->entry, &wakeup_sources);
 185         spin_unlock_irqrestore(&events_lock, flags);
 186 }
 187 EXPORT_SYMBOL_GPL(wakeup_source_add);
 188
 189 /**
 190  * wakeup_source_remove - Remove given object from the wakeup sources list.
 191  * @ws: Wakeup source object to remove from the list.
 192  */
 193 void wakeup_source_remove(struct wakeup_source *ws)
 194 {
 195         unsigned long flags;
 196
 197         if (WARN_ON(!ws))
 198                 return;
 199
 200         spin_lock_irqsave(&events_lock, flags);
 201         list_del_rcu(&ws->entry);
 202         spin_unlock_irqrestore(&events_lock, flags);
 203         synchronize_srcu(&wakeup_srcu);
 204 }
 205 EXPORT_SYMBOL_GPL(wakeup_source_remove);
 206
 207 /**
 208  * wakeup_source_register - Create wakeup source and add it to the list.
 209  * @name: Name of the wakeup source to register.
 210  */
 211 struct wakeup_source *wakeup_source_register(const char *name)
 212 {
 213         struct wakeup_source *ws;
 214
 215         ws = wakeup_source_create(name);
 216         if (ws)
 217                 wakeup_source_add(ws);
 218
 219         return ws;
 220 }
 221 EXPORT_SYMBOL_GPL(wakeup_source_register);
 222
 223 /**
 224  * wakeup_source_unregister - Remove wakeup source from the list and remove it.
 225  * @ws: Wakeup source object to unregister.
 226  */
 227 void wakeup_source_unregister(struct wakeup_source *ws)
 228 {
 229         if (ws) {
 230                 wakeup_source_remove(ws);
 231                 wakeup_source_destroy(ws);
 232         }
 233 }
 234 EXPORT_SYMBOL_GPL(wakeup_source_unregister);
 235
 236 /**
 237  * device_wakeup_attach - Attach a wakeup source object to a device object.
 238  * @dev: Device to handle.
 239  * @ws: Wakeup source object to attach to @dev.
 240  *
 241  * This causes @dev to be treated as a wakeup device.
 242  */
 243 static int device_wakeup_attach(struct device *dev, struct wakeup_source *ws)
 244 {
 245         spin_lock_irq(&dev->power.lock);
 246         if (dev->power.wakeup) {
 247                 spin_unlock_irq(&dev->power.lock);
 248                 return -EEXIST;
 249         }
 250         dev->power.wakeup = ws;
 251         if (dev->power.wakeirq)
 252                 device_wakeup_attach_irq(dev, dev->power.wakeirq);
 253         spin_unlock_irq(&dev->power.lock);
 254         return 0;
 255 }
 256
 257 /**
 258  * device_wakeup_enable - Enable given device to be a wakeup source.
 259  * @dev: Device to handle.
 260  *
 261  * Create a wakeup source object, register it and attach it to @dev.
 262  */
 263 int device_wakeup_enable(struct device *dev)
 264 {
 265         struct wakeup_source *ws;
 266         int ret;
 267
 268         if (!dev || !dev->power.can_wakeup)
 269                 return -EINVAL;
 270
 271         ws = wakeup_source_register(dev_name(dev));
 272         if (!ws)
 273                 return -ENOMEM;
 274
 275         ret = device_wakeup_attach(dev, ws);
 276         if (ret)
 277                 wakeup_source_unregister(ws);
 278
 279         return ret;
 280 }
 281 EXPORT_SYMBOL_GPL(device_wakeup_enable);
 282
 283 /**
 284  * device_wakeup_attach_irq - Attach a wakeirq to a wakeup source
 285  * @dev: Device to handle
 286  * @wakeirq: Device specific wakeirq entry
 287  *
 288  * Attach a device wakeirq to the wakeup source so the device
 289  * wake IRQ can be configured automatically for suspend and
 290  * resume.
 291  *
 292  * Call under the device's power.lock lock.
 293  */
 294 int device_wakeup_attach_irq(struct device *dev,
 295                              struct wake_irq *wakeirq)
 296 {
 297         struct wakeup_source *ws;
 298
 299         ws = dev->power.wakeup;
 300         if (!ws) {
 301                 dev_err(dev, "forgot to call call device_init_wakeup?\n");
 302                 return -EINVAL;
 303         }
 304
 305         if (ws->wakeirq)
 306                 return -EEXIST;
 307
 308         ws->wakeirq = wakeirq;
 309         return 0;
 310 }
 311
 312 /**
 313  * device_wakeup_detach_irq - Detach a wakeirq from a wakeup source
 314  * @dev: Device to handle
 315  *
 316  * Removes a device wakeirq from the wakeup source.
 317  *
 318  * Call under the device's power.lock lock.
 319  */
 320 void device_wakeup_detach_irq(struct device *dev)
 321 {
 322         struct wakeup_source *ws;
 323
 324         ws = dev->power.wakeup;
 325         if (ws)
 326                 ws->wakeirq = NULL;
 327 }
 328
 329 /**
 330  * device_wakeup_arm_wake_irqs(void)
 331  *
 332  * Itereates over the list of device wakeirqs to arm them.
 333  */
 334 void device_wakeup_arm_wake_irqs(void)
 335 {
 336         struct wakeup_source *ws;
 337         int srcuidx;
 338
 339         srcuidx = srcu_read_lock(&wakeup_srcu);
 340         list_for_each_entry_rcu(ws, &wakeup_sources, entry)
 341                 dev_pm_arm_wake_irq(ws->wakeirq);
 342         srcu_read_unlock(&wakeup_srcu, srcuidx);
 343 }
 344
 345 /**
 346  * device_wakeup_disarm_wake_irqs(void)
 347  *
 348  * Itereates over the list of device wakeirqs to disarm them.
 349  */
 350 void device_wakeup_disarm_wake_irqs(void)
 351 {
 352         struct wakeup_source *ws;
 353         int srcuidx;
 354
 355         srcuidx = srcu_read_lock(&wakeup_srcu);
 356         list_for_each_entry_rcu(ws, &wakeup_sources, entry)
 357                 dev_pm_disarm_wake_irq(ws->wakeirq);
 358         srcu_read_unlock(&wakeup_srcu, srcuidx);
 359 }
 360
 361 /**
 362  * device_wakeup_detach - Detach a device's wakeup source object from it.
 363  * @dev: Device to detach the wakeup source object from.
 364  *
 365  * After it returns, @dev will not be treated as a wakeup device any more.
 366  */
 367 static struct wakeup_source *device_wakeup_detach(struct device *dev)
 368 {
 369         struct wakeup_source *ws;
 370
 371         spin_lock_irq(&dev->power.lock);
 372         ws = dev->power.wakeup;
 373         dev->power.wakeup = NULL;
 374         spin_unlock_irq(&dev->power.lock);
 375         return ws;
 376 }
 377
 378 /**
 379  * device_wakeup_disable - Do not regard a device as a wakeup source any more.
 380  * @dev: Device to handle.
 381  *
 382  * Detach the @dev's wakeup source object from it, unregister this wakeup source
 383  * object and destroy it.
 384  */
 385 int device_wakeup_disable(struct device *dev)
 386 {
 387         struct wakeup_source *ws;
 388
 389         if (!dev || !dev->power.can_wakeup)
 390                 return -EINVAL;
 391
 392         ws = device_wakeup_detach(dev);
 393         wakeup_source_unregister(ws);
 394         return 0;
 395 }
 396 EXPORT_SYMBOL_GPL(device_wakeup_disable);
 397
 398 /**
 399  * device_set_wakeup_capable - Set/reset device wakeup capability flag.
 400  * @dev: Device to handle.
 401  * @capable: Whether or not @dev is capable of waking up the system from sleep.
 402  *
 403  * If @capable is set, set the @dev's power.can_wakeup flag and add its
 404  * wakeup-related attributes to sysfs.  Otherwise, unset the @dev's
 405  * power.can_wakeup flag and remove its wakeup-related attributes from sysfs.
 406  *
 407  * This function may sleep and it can't be called from any context where
 408  * sleeping is not allowed.
 409  */
 410 void device_set_wakeup_capable(struct device *dev, bool capable)
 411 {
 412         if (!!dev->power.can_wakeup == !!capable)
 413                 return;
 414
 415         if (device_is_registered(dev) && !list_empty(&dev->power.entry)) {
 416                 if (capable) {
 417                         if (wakeup_sysfs_add(dev))
 418                                 return;
 419                 } else {
 420                         wakeup_sysfs_remove(dev);
 421                 }
 422         }
 423         dev->power.can_wakeup = capable;
 424 }
 425 EXPORT_SYMBOL_GPL(device_set_wakeup_capable);
 426
 427 /**
 428  * device_init_wakeup - Device wakeup initialization.
 429  * @dev: Device to handle.
 430  * @enable: Whether or not to enable @dev as a wakeup device.
 431  *
 432  * By default, most devices should leave wakeup disabled.  The exceptions are
 433  * devices that everyone expects to be wakeup sources: keyboards, power buttons,
 434  * possibly network interfaces, etc.  Also, devices that don't generate their
 435  * own wakeup requests but merely forward requests from one bus to another
 436  * (like PCI bridges) should have wakeup enabled by default.
 437  */
 438 int device_init_wakeup(struct device *dev, bool enable)
 439 {
 440         int ret = 0;
 441
 442         if (!dev)
 443                 return -EINVAL;
 444
 445         if (enable) {
 446                 device_set_wakeup_capable(dev, true);
 447                 ret = device_wakeup_enable(dev);
 448         } else {
 449                 if (dev->power.can_wakeup)
 450                         device_wakeup_disable(dev);
 451
 452                 device_set_wakeup_capable(dev, false);
 453         }
 454
 455         return ret;
 456 }
 457 EXPORT_SYMBOL_GPL(device_init_wakeup);
 458
 459 /**
 460  * device_set_wakeup_enable - Enable or disable a device to wake up the system.
 461  * @dev: Device to handle.
 462  */
 463 int device_set_wakeup_enable(struct device *dev, bool enable)
 464 {
 465         if (!dev || !dev->power.can_wakeup)
 466                 return -EINVAL;
 467
 468         return enable ? device_wakeup_enable(dev) : device_wakeup_disable(dev);
 469 }
 470 EXPORT_SYMBOL_GPL(device_set_wakeup_enable);
 471
 472 /**
 473  * wakeup_source_not_registered - validate the given wakeup source.
 474  * @ws: Wakeup source to be validated.
 475  */
 476 static bool wakeup_source_not_registered(struct wakeup_source *ws)
 477 {
 478         /*
 479          * Use timer struct to check if the given source is initialized
 480          * by wakeup_source_add.
 481          */
 482         return ws->timer.function != pm_wakeup_timer_fn ||
 483                    ws->timer.data != (unsigned long)ws;
 484 }
 485
 486 /*
 487  * The functions below use the observation that each wakeup event starts a
 488  * period in which the system should not be suspended.  The moment this period
 489  * will end depends on how the wakeup event is going to be processed after being
 490  * detected and all of the possible cases can be divided into two distinct
 491  * groups.
 492  *
 493  * First, a wakeup event may be detected by the same functional unit that will
 494  * carry out the entire processing of it and possibly will pass it to user space
 495  * for further processing.  In that case the functional unit that has detected
 496  * the event may later "close" the "no suspend" period associated with it
 497  * directly as soon as it has been dealt with.  The pair of pm_stay_awake() and
 498  * pm_relax(), balanced with each other, is supposed to be used in such
 499  * situations.
 500  *
 501  * Second, a wakeup event may be detected by one functional unit and processed
 502  * by another one.  In that case the unit that has detected it cannot really
 503  * "close" the "no suspend" period associated with it, unless it knows in
 504  * advance what's going to happen to the event during processing.  This
 505  * knowledge, however, may not be available to it, so it can simply specify time
 506  * to wait before the system can be suspended and pass it as the second
 507  * argument of pm_wakeup_event().
 508  *
 509  * It is valid to call pm_relax() after pm_wakeup_event(), in which case the
 510  * "no suspend" period will be ended either by the pm_relax(), or by the timer
 511  * function executed when the timer expires, whichever comes first.
 512  */
 513
 514 /**
 515  * wakup_source_activate - Mark given wakeup source as active.
 516  * @ws: Wakeup source to handle.
 517  *
 518  * Update the @ws' statistics and, if @ws has just been activated, notify the PM
 519  * core of the event by incrementing the counter of of wakeup events being
 520  * processed.
 521  */
 522 static void wakeup_source_activate(struct wakeup_source *ws)
 523 {
 524         unsigned int cec;
 525
 526         if (WARN_ONCE(wakeup_source_not_registered(ws),
 527                         "unregistered wakeup source\n"))
 528                 return;
 529
 530         ws->active = true;
 531         ws->active_count++;
 532         ws->last_time = ktime_get();
 533         if (ws->autosleep_enabled)
 534                 ws->start_prevent_time = ws->last_time;
 535
 536         /* Increment the counter of events in progress. */
 537         cec = atomic_inc_return(&combined_event_count);
 538
 539         trace_wakeup_source_activate(ws->name, cec);
 540 }
 541
 542 /**
 543  * wakeup_source_report_event - Report wakeup event using the given source.
 544  * @ws: Wakeup source to report the event for.
 545  * @hard: If set, abort suspends in progress and wake up from suspend-to-idle.
 546  */
 547 static void wakeup_source_report_event(struct wakeup_source *ws, bool hard)
 548 {
 549         ws->event_count++;
 550         /* This is racy, but the counter is approximate anyway. */
 551         if (events_check_enabled)
 552                 ws->wakeup_count++;
 553
 554         if (!ws->active)
 555                 wakeup_source_activate(ws);
 556
 557         if (hard)
 558                 pm_system_wakeup();
 559 }
 560
 561 /**
 562  * __pm_stay_awake - Notify the PM core of a wakeup event.
 563  * @ws: Wakeup source object associated with the source of the event.
 564  *
 565  * It is safe to call this function from interrupt context.
 566  */
 567 void __pm_stay_awake(struct wakeup_source *ws)
 568 {
 569         unsigned long flags;
 570
 571         if (!ws)
 572                 return;
 573
 574         spin_lock_irqsave(&ws->lock, flags);
 575
 576         wakeup_source_report_event(ws, false);
 577         del_timer(&ws->timer);
 578         ws->timer_expires = 0;
 579
 580         spin_unlock_irqrestore(&ws->lock, flags);
 581 }
 582 EXPORT_SYMBOL_GPL(__pm_stay_awake);
 583
 584 /**
 585  * pm_stay_awake - Notify the PM core that a wakeup event is being processed.
 586  * @dev: Device the wakeup event is related to.
 587  *
 588  * Notify the PM core of a wakeup event (signaled by @dev) by calling
 589  * __pm_stay_awake for the @dev's wakeup source object.
 590  *
 591  * Call this function after detecting of a wakeup event if pm_relax() is going
 592  * to be called directly after processing the event (and possibly passing it to
 593  * user space for further processing).
 594  */
 595 void pm_stay_awake(struct device *dev)
 596 {
 597         unsigned long flags;
 598
 599         if (!dev)
 600                 return;
 601
 602         spin_lock_irqsave(&dev->power.lock, flags);
 603         __pm_stay_awake(dev->power.wakeup);
 604         spin_unlock_irqrestore(&dev->power.lock, flags);
 605 }
 606 EXPORT_SYMBOL_GPL(pm_stay_awake);
 607
 608 #ifdef CONFIG_PM_AUTOSLEEP
 609 static void update_prevent_sleep_time(struct wakeup_source *ws, ktime_t now)
 610 {
 611         ktime_t delta = ktime_sub(now, ws->start_prevent_time);
 612         ws->prevent_sleep_time = ktime_add(ws->prevent_sleep_time, delta);
 613 }
 614 #else
 615 static inline void update_prevent_sleep_time(struct wakeup_source *ws,
 616                                              ktime_t now) {}
 617 #endif
 618
 619 /**
 620  * wakup_source_deactivate - Mark given wakeup source as inactive.
 621  * @ws: Wakeup source to handle.
 622  *
 623  * Update the @ws' statistics and notify the PM core that the wakeup source has
 624  * become inactive by decrementing the counter of wakeup events being processed
 625  * and incrementing the counter of registered wakeup events.
 626  */
 627 static void wakeup_source_deactivate(struct wakeup_source *ws)
 628 {
 629         unsigned int cnt, inpr, cec;
 630         ktime_t duration;
 631         ktime_t now;
 632
 633         ws->relax_count++;
 634         /*
 635          * __pm_relax() may be called directly or from a timer function.
 636          * If it is called directly right after the timer function has been
 637          * started, but before the timer function calls __pm_relax(), it is
 638          * possible that __pm_stay_awake() will be called in the meantime and
 639          * will set ws->active.  Then, ws->active may be cleared immediately
 640          * by the __pm_relax() called from the timer function, but in such a
 641          * case ws->relax_count will be different from ws->active_count.
 642          */
 643         if (ws->relax_count != ws->active_count) {
 644                 ws->relax_count--;
 645                 return;
 646         }
 647
 648         ws->active = false;
 649
 650         now = ktime_get();
 651         duration = ktime_sub(now, ws->last_time);
 652         ws->total_time = ktime_add(ws->total_time, duration);
 653         if (ktime_to_ns(duration) > ktime_to_ns(ws->max_time))
 654                 ws->max_time = duration;
 655
 656         ws->last_time = now;
 657         del_timer(&ws->timer);
 658         ws->timer_expires = 0;
 659
 660         if (ws->autosleep_enabled)
 661                 update_prevent_sleep_time(ws, now);
 662
 663         /*
 664          * Increment the counter of registered wakeup events and decrement the
 665          * couter of wakeup events in progress simultaneously.
 666          */
 667         cec = atomic_add_return(MAX_IN_PROGRESS, &combined_event_count);
 668         trace_wakeup_source_deactivate(ws->name, cec);
 669
 670         split_counters(&cnt, &inpr);
 671         if (!inpr && waitqueue_active(&wakeup_count_wait_queue))
 672                 wake_up(&wakeup_count_wait_queue);
 673 }
 674
 675 /**
 676  * __pm_relax - Notify the PM core that processing of a wakeup event has ended.
 677  * @ws: Wakeup source object associated with the source of the event.
 678  *
 679  * Call this function for wakeup events whose processing started with calling
 680  * __pm_stay_awake().
 681  *
 682  * It is safe to call it from interrupt context.
 683  */
 684 void __pm_relax(struct wakeup_source *ws)
 685 {
 686         unsigned long flags;
 687
 688         if (!ws)
 689                 return;
 690
 691         spin_lock_irqsave(&ws->lock, flags);
 692         if (ws->active)
 693                 wakeup_source_deactivate(ws);
 694         spin_unlock_irqrestore(&ws->lock, flags);
 695 }
 696 EXPORT_SYMBOL_GPL(__pm_relax);
 697
 698 /**
 699  * pm_relax - Notify the PM core that processing of a wakeup event has ended.
 700  * @dev: Device that signaled the event.
 701  *
 702  * Execute __pm_relax() for the @dev's wakeup source object.
 703  */
 704 void pm_relax(struct device *dev)
 705 {
 706         unsigned long flags;
 707
 708         if (!dev)
 709                 return;
 710
 711         spin_lock_irqsave(&dev->power.lock, flags);
 712         __pm_relax(dev->power.wakeup);
 713         spin_unlock_irqrestore(&dev->power.lock, flags);
 714 }
 715 EXPORT_SYMBOL_GPL(pm_relax);
 716
 717 /**
 718  * pm_wakeup_timer_fn - Delayed finalization of a wakeup event.
 719  * @data: Address of the wakeup source object associated with the event source.
 720  *
 721  * Call wakeup_source_deactivate() for the wakeup source whose address is stored
 722  * in @data if it is currently active and its timer has not been canceled and
 723  * the expiration time of the timer is not in future.
 724  */
 725 static void pm_wakeup_timer_fn(unsigned long data)
 726 {
 727         struct wakeup_source *ws = (struct wakeup_source *)data;
 728         unsigned long flags;
 729
 730         spin_lock_irqsave(&ws->lock, flags);
 731
 732         if (ws->active && ws->timer_expires
 733             && time_after_eq(jiffies, ws->timer_expires)) {
 734                 wakeup_source_deactivate(ws);
 735                 ws->expire_count++;
 736         }
 737
 738         spin_unlock_irqrestore(&ws->lock, flags);
 739 }
 740
 741 /**
 742  * pm_wakeup_ws_event - Notify the PM core of a wakeup event.
 743  * @ws: Wakeup source object associated with the event source.
 744  * @msec: Anticipated event processing time (in milliseconds).
 745  * @hard: If set, abort suspends in progress and wake up from suspend-to-idle.
 746  *
 747  * Notify the PM core of a wakeup event whose source is @ws that will take
 748  * approximately @msec milliseconds to be processed by the kernel.  If @ws is
 749  * not active, activate it.  If @msec is nonzero, set up the @ws' timer to
 750  * execute pm_wakeup_timer_fn() in future.
 751  *
 752  * It is safe to call this function from interrupt context.
 753  */
 754 void pm_wakeup_ws_event(struct wakeup_source *ws, unsigned int msec, bool hard)
 755 {
 756         unsigned long flags;
 757         unsigned long expires;
 758
 759         if (!ws)
 760                 return;
 761
 762         spin_lock_irqsave(&ws->lock, flags);
 763
 764         wakeup_source_report_event(ws, hard);
 765
 766         if (!msec) {
 767                 wakeup_source_deactivate(ws);
 768                 goto unlock;
 769         }
 770
 771         expires = jiffies + msecs_to_jiffies(msec);
 772         if (!expires)
 773                 expires = 1;
 774
 775         if (!ws->timer_expires || time_after(expires, ws->timer_expires)) {
 776                 mod_timer(&ws->timer, expires);
 777                 ws->timer_expires = expires;
 778         }
 779
 780  unlock:
 781         spin_unlock_irqrestore(&ws->lock, flags);
 782 }
 783 EXPORT_SYMBOL_GPL(pm_wakeup_ws_event);
 784
 785 /**
 786  * pm_wakeup_event - Notify the PM core of a wakeup event.
 787  * @dev: Device the wakeup event is related to.
 788  * @msec: Anticipated event processing time (in milliseconds).
 789  * @hard: If set, abort suspends in progress and wake up from suspend-to-idle.
 790  *
 791  * Call pm_wakeup_ws_event() for the @dev's wakeup source object.
 792  */
 793 void pm_wakeup_dev_event(struct device *dev, unsigned int msec, bool hard)
 794 {
 795         unsigned long flags;
 796
 797         if (!dev)
 798                 return;
 799
 800         spin_lock_irqsave(&dev->power.lock, flags);
 801         pm_wakeup_ws_event(dev->power.wakeup, msec, hard);
 802         spin_unlock_irqrestore(&dev->power.lock, flags);
 803 }
 804 EXPORT_SYMBOL_GPL(pm_wakeup_dev_event);
 805
 806 void pm_print_active_wakeup_sources(void)
 807 {
 808         struct wakeup_source *ws;
 809         int srcuidx, active = 0;
 810         struct wakeup_source *last_activity_ws = NULL;
 811
 812         srcuidx = srcu_read_lock(&wakeup_srcu);
 813         list_for_each_entry_rcu(ws, &wakeup_sources, entry) {
 814                 if (ws->active) {
 815                         pr_debug("active wakeup source: %s\n", ws->name);
 816                         active = 1;
 817                 } else if (!active &&
 818                            (!last_activity_ws ||
 819                             ktime_to_ns(ws->last_time) >
 820                             ktime_to_ns(last_activity_ws->last_time))) {
 821                         last_activity_ws = ws;
 822                 }
 823         }
 824
 825         if (!active && last_activity_ws)
 826                 pr_debug("last active wakeup source: %s\n",
 827                         last_activity_ws->name);
 828         srcu_read_unlock(&wakeup_srcu, srcuidx);
 829 }
 830 EXPORT_SYMBOL_GPL(pm_print_active_wakeup_sources);
 831
 832 /**
 833  * pm_wakeup_pending - Check if power transition in progress should be aborted.
 834  *
 835  * Compare the current number of registered wakeup events with its preserved
 836  * value from the past and return true if new wakeup events have been registered
 837  * since the old value was stored.  Also return true if the current number of
 838  * wakeup events being processed is different from zero.
 839  */
 840 bool pm_wakeup_pending(void)
 841 {
 842         unsigned long flags;
 843         bool ret = false;
 844
 845         spin_lock_irqsave(&events_lock, flags);
 846         if (events_check_enabled) {
 847                 unsigned int cnt, inpr;
 848
 849                 split_counters(&cnt, &inpr);
 850                 ret = (cnt != saved_count || inpr > 0);
 851                 events_check_enabled = !ret;
 852         }
 853         spin_unlock_irqrestore(&events_lock, flags);
 854
 855         if (ret) {
 856                 pr_info("PM: Wakeup pending, aborting suspend\n");
 857                 pm_print_active_wakeup_sources();
 858         }
 859
 860         return ret || atomic_read(&pm_abort_suspend) > 0;
 861 }
 862
 863 void pm_system_wakeup(void)
 864 {
 865         atomic_inc(&pm_abort_suspend);
 866         freeze_wake();
 867 }
 868 EXPORT_SYMBOL_GPL(pm_system_wakeup);
 869
 870 void pm_system_cancel_wakeup(void)
 871 {
 872         atomic_dec(&pm_abort_suspend);
 873 }
 874
 875 void pm_wakeup_clear(bool reset)
 876 {
 877         pm_wakeup_irq = 0;
 878         if (reset)
 879                 atomic_set(&pm_abort_suspend, 0);
 880 }
 881
 882 void pm_system_irq_wakeup(unsigned int irq_number)
 883 {
 884         if (pm_wakeup_irq == 0) {
 885                 pm_wakeup_irq = irq_number;
 886                 pm_system_wakeup();
 887         }
 888 }
 889
 890 /**
 891  * pm_get_wakeup_count - Read the number of registered wakeup events.
 892  * @count: Address to store the value at.
 893  * @block: Whether or not to block.
 894  *
 895  * Store the number of registered wakeup events at the address in @count.  If
 896  * @block is set, block until the current number of wakeup events being
 897  * processed is zero.
 898  *
 899  * Return 'false' if the current number of wakeup events being processed is
 900  * nonzero.  Otherwise return 'true'.
 901  */
 902 bool pm_get_wakeup_count(unsigned int *count, bool block)
 903 {
 904         unsigned int cnt, inpr;
 905
 906         if (block) {
 907                 DEFINE_WAIT(wait);
 908
 909                 for (;;) {
 910                         prepare_to_wait(&wakeup_count_wait_queue, &wait,
 911                                         TASK_INTERRUPTIBLE);
 912                         split_counters(&cnt, &inpr);
 913                         if (inpr == 0 || signal_pending(current))
 914                                 break;
 915                         pm_print_active_wakeup_sources();
 916                         schedule();
 917                 }
 918                 finish_wait(&wakeup_count_wait_queue, &wait);
 919         }
 920
 921         split_counters(&cnt, &inpr);
 922         *count = cnt;
 923         return !inpr;
 924 }
 925
 926 /**
 927  * pm_save_wakeup_count - Save the current number of registered wakeup events.
 928  * @count: Value to compare with the current number of registered wakeup events.
 929  *
 930  * If @count is equal to the current number of registered wakeup events and the
 931  * current number of wakeup events being processed is zero, store @count as the
 932  * old number of registered wakeup events for pm_check_wakeup_events(), enable
 933  * wakeup events detection and return 'true'.  Otherwise disable wakeup events
 934  * detection and return 'false'.
 935  */
 936 bool pm_save_wakeup_count(unsigned int count)
 937 {
 938         unsigned int cnt, inpr;
 939         unsigned long flags;
 940
 941         events_check_enabled = false;
 942         spin_lock_irqsave(&events_lock, flags);
 943         split_counters(&cnt, &inpr);
 944         if (cnt == count && inpr == 0) {
 945                 saved_count = count;
 946                 events_check_enabled = true;
 947         }
 948         spin_unlock_irqrestore(&events_lock, flags);
 949         return events_check_enabled;
 950 }
 951
 952 #ifdef CONFIG_PM_AUTOSLEEP
 953 /**
 954  * pm_wakep_autosleep_enabled - Modify autosleep_enabled for all wakeup sources.
 955  * @enabled: Whether to set or to clear the autosleep_enabled flags.
 956  */
 957 void pm_wakep_autosleep_enabled(bool set)
 958 {
 959         struct wakeup_source *ws;
 960         ktime_t now = ktime_get();
 961         int srcuidx;
 962
 963         srcuidx = srcu_read_lock(&wakeup_srcu);
 964         list_for_each_entry_rcu(ws, &wakeup_sources, entry) {
 965                 spin_lock_irq(&ws->lock);
 966                 if (ws->autosleep_enabled != set) {
 967                         ws->autosleep_enabled = set;
 968                         if (ws->active) {
 969                                 if (set)
 970                                         ws->start_prevent_time = now;
 971                                 else
 972                                         update_prevent_sleep_time(ws, now);
 973                         }
 974                 }
 975                 spin_unlock_irq(&ws->lock);
 976         }
 977         srcu_read_unlock(&wakeup_srcu, srcuidx);
 978 }
 979 #endif /* CONFIG_PM_AUTOSLEEP */
 980
 981 static struct dentry *wakeup_sources_stats_dentry;
 982
 983 /**
 984  * print_wakeup_source_stats - Print wakeup source statistics information.
 985  * @m: seq_file to print the statistics into.
 986  * @ws: Wakeup source object to print the statistics for.
 987  */
 988 static int print_wakeup_source_stats(struct seq_file *m,
 989                                      struct wakeup_source *ws)
 990 {
 991         unsigned long flags;
 992         ktime_t total_time;
 993         ktime_t max_time;
 994         unsigned long active_count;
 995         ktime_t active_time;
 996         ktime_t prevent_sleep_time;
 997
 998         spin_lock_irqsave(&ws->lock, flags);
 999
1000         total_time = ws->total_time;
1001         max_time = ws->max_time;
1002         prevent_sleep_time = ws->prevent_sleep_time;
1003         active_count = ws->active_count;
1004         if (ws->active) {
1005                 ktime_t now = ktime_get();
1006
1007                 active_time = ktime_sub(now, ws->last_time);
1008                 total_time = ktime_add(total_time, active_time);
1009                 if (active_time > max_time)
1010                         max_time = active_time;
1011
1012                 if (ws->autosleep_enabled)
1013                         prevent_sleep_time = ktime_add(prevent_sleep_time,
1014                                 ktime_sub(now, ws->start_prevent_time));
1015         } else {
1016                 active_time = 0;
1017         }
1018
1019         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",
1020                    ws->name, active_count, ws->event_count,
1021                    ws->wakeup_count, ws->expire_count,
1022                    ktime_to_ms(active_time), ktime_to_ms(total_time),
1023                    ktime_to_ms(max_time), ktime_to_ms(ws->last_time),
1024                    ktime_to_ms(prevent_sleep_time));
1025
1026         spin_unlock_irqrestore(&ws->lock, flags);
1027
1028         return 0;
1029 }
1030
1031 /**
1032  * wakeup_sources_stats_show - Print wakeup sources statistics information.
1033  * @m: seq_file to print the statistics into.
1034  */
1035 static int wakeup_sources_stats_show(struct seq_file *m, void *unused)
1036 {
1037         struct wakeup_source *ws;
1038         int srcuidx;
1039
1040         seq_puts(m, "name\t\tactive_count\tevent_count\twakeup_count\t"
1041                 "expire_count\tactive_since\ttotal_time\tmax_time\t"
1042                 "last_change\tprevent_suspend_time\n");
1043
1044         srcuidx = srcu_read_lock(&wakeup_srcu);
1045         list_for_each_entry_rcu(ws, &wakeup_sources, entry)
1046                 print_wakeup_source_stats(m, ws);
1047         srcu_read_unlock(&wakeup_srcu, srcuidx);
1048
1049         print_wakeup_source_stats(m, &deleted_ws);
1050
1051         return 0;
1052 }
1053
1054 static int wakeup_sources_stats_open(struct inode *inode, struct file *file)
1055 {
1056         return single_open(file, wakeup_sources_stats_show, NULL);
1057 }
1058
1059 static const struct file_operations wakeup_sources_stats_fops = {
1060         .owner = THIS_MODULE,
1061         .open = wakeup_sources_stats_open,
1062         .read = seq_read,
1063         .llseek = seq_lseek,
1064         .release = single_release,
1065 };
1066
1067 static int __init wakeup_sources_debugfs_init(void)
1068 {
1069         wakeup_sources_stats_dentry = debugfs_create_file("wakeup_sources",
1070                         S_IRUGO, NULL, NULL, &wakeup_sources_stats_fops);
1071         return 0;
1072 }
1073
1074 postcore_initcall(wakeup_sources_debugfs_init);