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