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 static struct wakeup_source deleted_ws = {
  61         .name = "deleted",
  62         .lock =  __SPIN_LOCK_UNLOCKED(deleted_ws.lock),
  63 };
  64
  65 /**
  66  * wakeup_source_prepare - Prepare a new wakeup source for initialization.
  67  * @ws: Wakeup source to prepare.
  68  * @name: Pointer to the name of the new wakeup source.
  69  *
  70  * Callers must ensure that the @name string won't be freed when @ws is still in
  71  * use.
  72  */
  73 void wakeup_source_prepare(struct wakeup_source *ws, const char *name)
  74 {
  75         if (ws) {
  76                 memset(ws, 0, sizeof(*ws));
  77                 ws->name = name;
  78         }
  79 }
  80 EXPORT_SYMBOL_GPL(wakeup_source_prepare);
  81
  82 /**
  83  * wakeup_source_create - Create a struct wakeup_source object.
  84  * @name: Name of the new wakeup source.
  85  */
  86 struct wakeup_source *wakeup_source_create(const char *name)
  87 {
  88         struct wakeup_source *ws;
  89
  90         ws = kmalloc(sizeof(*ws), GFP_KERNEL);
  91         if (!ws)
  92                 return NULL;
  93
  94         wakeup_source_prepare(ws, name ? kstrdup(name, GFP_KERNEL) : NULL);
  95         return ws;
  96 }
  97 EXPORT_SYMBOL_GPL(wakeup_source_create);
  98
  99 /**
 100  * wakeup_source_drop - Prepare a struct wakeup_source object for destruction.
 101  * @ws: Wakeup source to prepare for destruction.
 102  *
 103  * Callers must ensure that __pm_stay_awake() or __pm_wakeup_event() will never
 104  * be run in parallel with this function for the same wakeup source object.
 105  */
 106 void wakeup_source_drop(struct wakeup_source *ws)
 107 {
 108         if (!ws)
 109                 return;
 110
 111         del_timer_sync(&ws->timer);
 112         __pm_relax(ws);
 113 }
 114 EXPORT_SYMBOL_GPL(wakeup_source_drop);
 115
 116 /*
 117  * Record wakeup_source statistics being deleted into a dummy wakeup_source.
 118  */
 119 static void wakeup_source_record(struct wakeup_source *ws)
 120 {
 121         unsigned long flags;
 122
 123         spin_lock_irqsave(&deleted_ws.lock, flags);
 124
 125         if (ws->event_count) {
 126                 deleted_ws.total_time =
 127                         ktime_add(deleted_ws.total_time, ws->total_time);
 128                 deleted_ws.prevent_sleep_time =
 129                         ktime_add(deleted_ws.prevent_sleep_time,
 130                                   ws->prevent_sleep_time);
 131                 deleted_ws.max_time =
 132                         ktime_compare(deleted_ws.max_time, ws->max_time) > 0 ?
 133                                 deleted_ws.max_time : ws->max_time;
 134                 deleted_ws.event_count += ws->event_count;
 135                 deleted_ws.active_count += ws->active_count;
 136                 deleted_ws.relax_count += ws->relax_count;
 137                 deleted_ws.expire_count += ws->expire_count;
 138                 deleted_ws.wakeup_count += ws->wakeup_count;
 139         }
 140
 141         spin_unlock_irqrestore(&deleted_ws.lock, flags);
 142 }
 143
 144 /**
 145  * wakeup_source_destroy - Destroy a struct wakeup_source object.
 146  * @ws: Wakeup source to destroy.
 147  *
 148  * Use only for wakeup source objects created with wakeup_source_create().
 149  */
 150 void wakeup_source_destroy(struct wakeup_source *ws)
 151 {
 152         if (!ws)
 153                 return;
 154
 155         wakeup_source_drop(ws);
 156         wakeup_source_record(ws);
 157         kfree(ws->name);
 158         kfree(ws);
 159 }
 160 EXPORT_SYMBOL_GPL(wakeup_source_destroy);
 161
 162 /**
 163  * wakeup_source_add - Add given object to the list of wakeup sources.
 164  * @ws: Wakeup source object to add to the list.
 165  */
 166 void wakeup_source_add(struct wakeup_source *ws)
 167 {
 168         unsigned long flags;
 169
 170         if (WARN_ON(!ws))
 171                 return;
 172
 173         spin_lock_init(&ws->lock);
 174         setup_timer(&ws->timer, pm_wakeup_timer_fn, (unsigned long)ws);
 175         ws->active = false;
 176         ws->last_time = ktime_get();
 177
 178         spin_lock_irqsave(&events_lock, flags);
 179         list_add_rcu(&ws->entry, &wakeup_sources);
 180         spin_unlock_irqrestore(&events_lock, flags);
 181 }
 182 EXPORT_SYMBOL_GPL(wakeup_source_add);
 183
 184 /**
 185  * wakeup_source_remove - Remove given object from the wakeup sources list.
 186  * @ws: Wakeup source object to remove from the list.
 187  */
 188 void wakeup_source_remove(struct wakeup_source *ws)
 189 {
 190         unsigned long flags;
 191
 192         if (WARN_ON(!ws))
 193                 return;
 194
 195         spin_lock_irqsave(&events_lock, flags);
 196         list_del_rcu(&ws->entry);
 197         spin_unlock_irqrestore(&events_lock, flags);
 198         synchronize_rcu();
 199 }
 200 EXPORT_SYMBOL_GPL(wakeup_source_remove);
 201
 202 /**
 203  * wakeup_source_register - Create wakeup source and add it to the list.
 204  * @name: Name of the wakeup source to register.
 205  */
 206 struct wakeup_source *wakeup_source_register(const char *name)
 207 {
 208         struct wakeup_source *ws;
 209
 210         ws = wakeup_source_create(name);
 211         if (ws)
 212                 wakeup_source_add(ws);
 213
 214         return ws;
 215 }
 216 EXPORT_SYMBOL_GPL(wakeup_source_register);
 217
 218 /**
 219  * wakeup_source_unregister - Remove wakeup source from the list and remove it.
 220  * @ws: Wakeup source object to unregister.
 221  */
 222 void wakeup_source_unregister(struct wakeup_source *ws)
 223 {
 224         if (ws) {
 225                 wakeup_source_remove(ws);
 226                 wakeup_source_destroy(ws);
 227         }
 228 }
 229 EXPORT_SYMBOL_GPL(wakeup_source_unregister);
 230
 231 /**
 232  * device_wakeup_attach - Attach a wakeup source object to a device object.
 233  * @dev: Device to handle.
 234  * @ws: Wakeup source object to attach to @dev.
 235  *
 236  * This causes @dev to be treated as a wakeup device.
 237  */
 238 static int device_wakeup_attach(struct device *dev, struct wakeup_source *ws)
 239 {
 240         spin_lock_irq(&dev->power.lock);
 241         if (dev->power.wakeup) {
 242                 spin_unlock_irq(&dev->power.lock);
 243                 return -EEXIST;
 244         }
 245         dev->power.wakeup = ws;
 246         spin_unlock_irq(&dev->power.lock);
 247         return 0;
 248 }
 249
 250 /**
 251  * device_wakeup_enable - Enable given device to be a wakeup source.
 252  * @dev: Device to handle.
 253  *
 254  * Create a wakeup source object, register it and attach it to @dev.
 255  */
 256 int device_wakeup_enable(struct device *dev)
 257 {
 258         struct wakeup_source *ws;
 259         int ret;
 260
 261         if (!dev || !dev->power.can_wakeup)
 262                 return -EINVAL;
 263
 264         ws = wakeup_source_register(dev_name(dev));
 265         if (!ws)
 266                 return -ENOMEM;
 267
 268         ret = device_wakeup_attach(dev, ws);
 269         if (ret)
 270                 wakeup_source_unregister(ws);
 271
 272         return ret;
 273 }
 274 EXPORT_SYMBOL_GPL(device_wakeup_enable);
 275
 276 /**
 277  * device_wakeup_attach_irq - Attach a wakeirq to a wakeup source
 278  * @dev: Device to handle
 279  * @wakeirq: Device specific wakeirq entry
 280  *
 281  * Attach a device wakeirq to the wakeup source so the device
 282  * wake IRQ can be configured automatically for suspend and
 283  * resume.
 284  *
 285  * Call under the device's power.lock lock.
 286  */
 287 int device_wakeup_attach_irq(struct device *dev,
 288                              struct wake_irq *wakeirq)
 289 {
 290         struct wakeup_source *ws;
 291
 292         ws = dev->power.wakeup;
 293         if (!ws) {
 294                 dev_err(dev, "forgot to call call device_init_wakeup?\n");
 295                 return -EINVAL;
 296         }
 297
 298         if (ws->wakeirq)
 299                 return -EEXIST;
 300
 301         ws->wakeirq = wakeirq;
 302         return 0;
 303 }
 304
 305 /**
 306  * device_wakeup_detach_irq - Detach a wakeirq from a wakeup source
 307  * @dev: Device to handle
 308  *
 309  * Removes a device wakeirq from the wakeup source.
 310  *
 311  * Call under the device's power.lock lock.
 312  */
 313 void device_wakeup_detach_irq(struct device *dev)
 314 {
 315         struct wakeup_source *ws;
 316
 317         ws = dev->power.wakeup;
 318         if (ws)
 319                 ws->wakeirq = NULL;
 320 }
 321
 322 /**
 323  * device_wakeup_arm_wake_irqs(void)
 324  *
 325  * Itereates over the list of device wakeirqs to arm them.
 326  */
 327 void device_wakeup_arm_wake_irqs(void)
 328 {
 329         struct wakeup_source *ws;
 330
 331         rcu_read_lock();
 332         list_for_each_entry_rcu(ws, &wakeup_sources, entry) {
 333                 if (ws->wakeirq)
 334                         dev_pm_arm_wake_irq(ws->wakeirq);
 335         }
 336         rcu_read_unlock();
 337 }
 338
 339 /**
 340  * device_wakeup_disarm_wake_irqs(void)
 341  *
 342  * Itereates over the list of device wakeirqs to disarm them.
 343  */
 344 void device_wakeup_disarm_wake_irqs(void)
 345 {
 346         struct wakeup_source *ws;
 347
 348         rcu_read_lock();
 349         list_for_each_entry_rcu(ws, &wakeup_sources, entry) {
 350                 if (ws->wakeirq)
 351                         dev_pm_disarm_wake_irq(ws->wakeirq);
 352         }
 353         rcu_read_unlock();
 354 }
 355
 356 /**
 357  * device_wakeup_detach - Detach a device's wakeup source object from it.
 358  * @dev: Device to detach the wakeup source object from.
 359  *
 360  * After it returns, @dev will not be treated as a wakeup device any more.
 361  */
 362 static struct wakeup_source *device_wakeup_detach(struct device *dev)
 363 {
 364         struct wakeup_source *ws;
 365
 366         spin_lock_irq(&dev->power.lock);
 367         ws = dev->power.wakeup;
 368         dev->power.wakeup = NULL;
 369         spin_unlock_irq(&dev->power.lock);
 370         return ws;
 371 }
 372
 373 /**
 374  * device_wakeup_disable - Do not regard a device as a wakeup source any more.
 375  * @dev: Device to handle.
 376  *
 377  * Detach the @dev's wakeup source object from it, unregister this wakeup source
 378  * object and destroy it.
 379  */
 380 int device_wakeup_disable(struct device *dev)
 381 {
 382         struct wakeup_source *ws;
 383
 384         if (!dev || !dev->power.can_wakeup)
 385                 return -EINVAL;
 386
 387         ws = device_wakeup_detach(dev);
 388         if (ws)
 389                 wakeup_source_unregister(ws);
 390
 391         return 0;
 392 }
 393 EXPORT_SYMBOL_GPL(device_wakeup_disable);
 394
 395 /**
 396  * device_set_wakeup_capable - Set/reset device wakeup capability flag.
 397  * @dev: Device to handle.
 398  * @capable: Whether or not @dev is capable of waking up the system from sleep.
 399  *
 400  * If @capable is set, set the @dev's power.can_wakeup flag and add its
 401  * wakeup-related attributes to sysfs.  Otherwise, unset the @dev's
 402  * power.can_wakeup flag and remove its wakeup-related attributes from sysfs.
 403  *
 404  * This function may sleep and it can't be called from any context where
 405  * sleeping is not allowed.
 406  */
 407 void device_set_wakeup_capable(struct device *dev, bool capable)
 408 {
 409         if (!!dev->power.can_wakeup == !!capable)
 410                 return;
 411
 412         if (device_is_registered(dev) && !list_empty(&dev->power.entry)) {
 413                 if (capable) {
 414                         if (wakeup_sysfs_add(dev))
 415                                 return;
 416                 } else {
 417                         wakeup_sysfs_remove(dev);
 418                 }
 419         }
 420         dev->power.can_wakeup = capable;
 421 }
 422 EXPORT_SYMBOL_GPL(device_set_wakeup_capable);
 423
 424 /**
 425  * device_init_wakeup - Device wakeup initialization.
 426  * @dev: Device to handle.
 427  * @enable: Whether or not to enable @dev as a wakeup device.
 428  *
 429  * By default, most devices should leave wakeup disabled.  The exceptions are
 430  * devices that everyone expects to be wakeup sources: keyboards, power buttons,
 431  * possibly network interfaces, etc.  Also, devices that don't generate their
 432  * own wakeup requests but merely forward requests from one bus to another
 433  * (like PCI bridges) should have wakeup enabled by default.
 434  */
 435 int device_init_wakeup(struct device *dev, bool enable)
 436 {
 437         int ret = 0;
 438
 439         if (!dev)
 440                 return -EINVAL;
 441
 442         if (enable) {
 443                 device_set_wakeup_capable(dev, true);
 444                 ret = device_wakeup_enable(dev);
 445         } else {
 446                 if (dev->power.can_wakeup)
 447                         device_wakeup_disable(dev);
 448
 449                 device_set_wakeup_capable(dev, false);
 450         }
 451
 452         return ret;
 453 }
 454 EXPORT_SYMBOL_GPL(device_init_wakeup);
 455
 456 /**
 457  * device_set_wakeup_enable - Enable or disable a device to wake up the system.
 458  * @dev: Device to handle.
 459  */
 460 int device_set_wakeup_enable(struct device *dev, bool enable)
 461 {
 462         if (!dev || !dev->power.can_wakeup)
 463                 return -EINVAL;
 464
 465         return enable ? device_wakeup_enable(dev) : device_wakeup_disable(dev);
 466 }
 467 EXPORT_SYMBOL_GPL(device_set_wakeup_enable);
 468
 469 /**
 470  * wakeup_source_not_registered - validate the given wakeup source.
 471  * @ws: Wakeup source to be validated.
 472  */
 473 static bool wakeup_source_not_registered(struct wakeup_source *ws)
 474 {
 475         /*
 476          * Use timer struct to check if the given source is initialized
 477          * by wakeup_source_add.
 478          */
 479         return ws->timer.function != pm_wakeup_timer_fn ||
 480                    ws->timer.data != (unsigned long)ws;
 481 }
 482
 483 /*
 484  * The functions below use the observation that each wakeup event starts a
 485  * period in which the system should not be suspended.  The moment this period
 486  * will end depends on how the wakeup event is going to be processed after being
 487  * detected and all of the possible cases can be divided into two distinct
 488  * groups.
 489  *
 490  * First, a wakeup event may be detected by the same functional unit that will
 491  * carry out the entire processing of it and possibly will pass it to user space
 492  * for further processing.  In that case the functional unit that has detected
 493  * the event may later "close" the "no suspend" period associated with it
 494  * directly as soon as it has been dealt with.  The pair of pm_stay_awake() and
 495  * pm_relax(), balanced with each other, is supposed to be used in such
 496  * situations.
 497  *
 498  * Second, a wakeup event may be detected by one functional unit and processed
 499  * by another one.  In that case the unit that has detected it cannot really
 500  * "close" the "no suspend" period associated with it, unless it knows in
 501  * advance what's going to happen to the event during processing.  This
 502  * knowledge, however, may not be available to it, so it can simply specify time
 503  * to wait before the system can be suspended and pass it as the second
 504  * argument of pm_wakeup_event().
 505  *
 506  * It is valid to call pm_relax() after pm_wakeup_event(), in which case the
 507  * "no suspend" period will be ended either by the pm_relax(), or by the timer
 508  * function executed when the timer expires, whichever comes first.
 509  */
 510
 511 /**
 512  * wakup_source_activate - Mark given wakeup source as active.
 513  * @ws: Wakeup source to handle.
 514  *
 515  * Update the @ws' statistics and, if @ws has just been activated, notify the PM
 516  * core of the event by incrementing the counter of of wakeup events being
 517  * processed.
 518  */
 519 static void wakeup_source_activate(struct wakeup_source *ws)
 520 {
 521         unsigned int cec;
 522
 523         if (WARN_ONCE(wakeup_source_not_registered(ws),
 524                         "unregistered wakeup source\n"))
 525                 return;
 526
 527         /*
 528          * active wakeup source should bring the system
 529          * out of PM_SUSPEND_FREEZE state
 530          */
 531         freeze_wake();
 532
 533         ws->active = true;
 534         ws->active_count++;
 535         ws->last_time = ktime_get();
 536         if (ws->autosleep_enabled)
 537                 ws->start_prevent_time = ws->last_time;
 538
 539         /* Increment the counter of events in progress. */
 540         cec = atomic_inc_return(&combined_event_count);
 541
 542         trace_wakeup_source_activate(ws->name, cec);
 543 }
 544
 545 /**
 546  * wakeup_source_report_event - Report wakeup event using the given source.
 547  * @ws: Wakeup source to report the event for.
 548  */
 549 static void wakeup_source_report_event(struct wakeup_source *ws)
 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);
 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);
 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_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  *
 745  * Notify the PM core of a wakeup event whose source is @ws that will take
 746  * approximately @msec milliseconds to be processed by the kernel.  If @ws is
 747  * not active, activate it.  If @msec is nonzero, set up the @ws' timer to
 748  * execute pm_wakeup_timer_fn() in future.
 749  *
 750  * It is safe to call this function from interrupt context.
 751  */
 752 void __pm_wakeup_event(struct wakeup_source *ws, unsigned int msec)
 753 {
 754         unsigned long flags;
 755         unsigned long expires;
 756
 757         if (!ws)
 758                 return;
 759
 760         spin_lock_irqsave(&ws->lock, flags);
 761
 762         wakeup_source_report_event(ws);
 763
 764         if (!msec) {
 765                 wakeup_source_deactivate(ws);
 766                 goto unlock;
 767         }
 768
 769         expires = jiffies + msecs_to_jiffies(msec);
 770         if (!expires)
 771                 expires = 1;
 772
 773         if (!ws->timer_expires || time_after(expires, ws->timer_expires)) {
 774                 mod_timer(&ws->timer, expires);
 775                 ws->timer_expires = expires;
 776         }
 777
 778  unlock:
 779         spin_unlock_irqrestore(&ws->lock, flags);
 780 }
 781 EXPORT_SYMBOL_GPL(__pm_wakeup_event);
 782
 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  *
 789  * Call __pm_wakeup_event() for the @dev's wakeup source object.
 790  */
 791 void pm_wakeup_event(struct device *dev, unsigned int msec)
 792 {
 793         unsigned long flags;
 794
 795         if (!dev)
 796                 return;
 797
 798         spin_lock_irqsave(&dev->power.lock, flags);
 799         __pm_wakeup_event(dev->power.wakeup, msec);
 800         spin_unlock_irqrestore(&dev->power.lock, flags);
 801 }
 802 EXPORT_SYMBOL_GPL(pm_wakeup_event);
 803
 804 void pm_print_active_wakeup_sources(void)
 805 {
 806         struct wakeup_source *ws;
 807         int active = 0;
 808         struct wakeup_source *last_activity_ws = NULL;
 809
 810         rcu_read_lock();
 811         list_for_each_entry_rcu(ws, &wakeup_sources, entry) {
 812                 if (ws->active) {
 813                         pr_info("active wakeup source: %s\n", ws->name);
 814                         active = 1;
 815                 } else if (!active &&
 816                            (!last_activity_ws ||
 817                             ktime_to_ns(ws->last_time) >
 818                             ktime_to_ns(last_activity_ws->last_time))) {
 819                         last_activity_ws = ws;
 820                 }
 821         }
 822
 823         if (!active && last_activity_ws)
 824                 pr_info("last active wakeup source: %s\n",
 825                         last_activity_ws->name);
 826         rcu_read_unlock();
 827 }
 828 EXPORT_SYMBOL_GPL(pm_print_active_wakeup_sources);
 829
 830 /**
 831  * pm_wakeup_pending - Check if power transition in progress should be aborted.
 832  *
 833  * Compare the current number of registered wakeup events with its preserved
 834  * value from the past and return true if new wakeup events have been registered
 835  * since the old value was stored.  Also return true if the current number of
 836  * wakeup events being processed is different from zero.
 837  */
 838 bool pm_wakeup_pending(void)
 839 {
 840         unsigned long flags;
 841         bool ret = false;
 842
 843         spin_lock_irqsave(&events_lock, flags);
 844         if (events_check_enabled) {
 845                 unsigned int cnt, inpr;
 846
 847                 split_counters(&cnt, &inpr);
 848                 ret = (cnt != saved_count || inpr > 0);
 849                 events_check_enabled = !ret;
 850         }
 851         spin_unlock_irqrestore(&events_lock, flags);
 852
 853         if (ret) {
 854                 pr_info("PM: Wakeup pending, aborting suspend\n");
 855                 pm_print_active_wakeup_sources();
 856         }
 857
 858         return ret || pm_abort_suspend;
 859 }
 860
 861 void pm_system_wakeup(void)
 862 {
 863         pm_abort_suspend = true;
 864         freeze_wake();
 865 }
 866 EXPORT_SYMBOL_GPL(pm_system_wakeup);
 867
 868 void pm_wakeup_clear(void)
 869 {
 870         pm_abort_suspend = false;
 871 }
 872
 873 /**
 874  * pm_get_wakeup_count - Read the number of registered wakeup events.
 875  * @count: Address to store the value at.
 876  * @block: Whether or not to block.
 877  *
 878  * Store the number of registered wakeup events at the address in @count.  If
 879  * @block is set, block until the current number of wakeup events being
 880  * processed is zero.
 881  *
 882  * Return 'false' if the current number of wakeup events being processed is
 883  * nonzero.  Otherwise return 'true'.
 884  */
 885 bool pm_get_wakeup_count(unsigned int *count, bool block)
 886 {
 887         unsigned int cnt, inpr;
 888
 889         if (block) {
 890                 DEFINE_WAIT(wait);
 891
 892                 for (;;) {
 893                         prepare_to_wait(&wakeup_count_wait_queue, &wait,
 894                                         TASK_INTERRUPTIBLE);
 895                         split_counters(&cnt, &inpr);
 896                         if (inpr == 0 || signal_pending(current))
 897                                 break;
 898
 899                         schedule();
 900                 }
 901                 finish_wait(&wakeup_count_wait_queue, &wait);
 902         }
 903
 904         split_counters(&cnt, &inpr);
 905         *count = cnt;
 906         return !inpr;
 907 }
 908
 909 /**
 910  * pm_save_wakeup_count - Save the current number of registered wakeup events.
 911  * @count: Value to compare with the current number of registered wakeup events.
 912  *
 913  * If @count is equal to the current number of registered wakeup events and the
 914  * current number of wakeup events being processed is zero, store @count as the
 915  * old number of registered wakeup events for pm_check_wakeup_events(), enable
 916  * wakeup events detection and return 'true'.  Otherwise disable wakeup events
 917  * detection and return 'false'.
 918  */
 919 bool pm_save_wakeup_count(unsigned int count)
 920 {
 921         unsigned int cnt, inpr;
 922         unsigned long flags;
 923
 924         events_check_enabled = false;
 925         spin_lock_irqsave(&events_lock, flags);
 926         split_counters(&cnt, &inpr);
 927         if (cnt == count && inpr == 0) {
 928                 saved_count = count;
 929                 events_check_enabled = true;
 930         }
 931         spin_unlock_irqrestore(&events_lock, flags);
 932         return events_check_enabled;
 933 }
 934
 935 #ifdef CONFIG_PM_AUTOSLEEP
 936 /**
 937  * pm_wakep_autosleep_enabled - Modify autosleep_enabled for all wakeup sources.
 938  * @enabled: Whether to set or to clear the autosleep_enabled flags.
 939  */
 940 void pm_wakep_autosleep_enabled(bool set)
 941 {
 942         struct wakeup_source *ws;
 943         ktime_t now = ktime_get();
 944
 945         rcu_read_lock();
 946         list_for_each_entry_rcu(ws, &wakeup_sources, entry) {
 947                 spin_lock_irq(&ws->lock);
 948                 if (ws->autosleep_enabled != set) {
 949                         ws->autosleep_enabled = set;
 950                         if (ws->active) {
 951                                 if (set)
 952                                         ws->start_prevent_time = now;
 953                                 else
 954                                         update_prevent_sleep_time(ws, now);
 955                         }
 956                 }
 957                 spin_unlock_irq(&ws->lock);
 958         }
 959         rcu_read_unlock();
 960 }
 961 #endif /* CONFIG_PM_AUTOSLEEP */
 962
 963 static struct dentry *wakeup_sources_stats_dentry;
 964
 965 /**
 966  * print_wakeup_source_stats - Print wakeup source statistics information.
 967  * @m: seq_file to print the statistics into.
 968  * @ws: Wakeup source object to print the statistics for.
 969  */
 970 static int print_wakeup_source_stats(struct seq_file *m,
 971                                      struct wakeup_source *ws)
 972 {
 973         unsigned long flags;
 974         ktime_t total_time;
 975         ktime_t max_time;
 976         unsigned long active_count;
 977         ktime_t active_time;
 978         ktime_t prevent_sleep_time;
 979
 980         spin_lock_irqsave(&ws->lock, flags);
 981
 982         total_time = ws->total_time;
 983         max_time = ws->max_time;
 984         prevent_sleep_time = ws->prevent_sleep_time;
 985         active_count = ws->active_count;
 986         if (ws->active) {
 987                 ktime_t now = ktime_get();
 988
 989                 active_time = ktime_sub(now, ws->last_time);
 990                 total_time = ktime_add(total_time, active_time);
 991                 if (active_time.tv64 > max_time.tv64)
 992                         max_time = active_time;
 993
 994                 if (ws->autosleep_enabled)
 995                         prevent_sleep_time = ktime_add(prevent_sleep_time,
 996                                 ktime_sub(now, ws->start_prevent_time));
 997         } else {
 998                 active_time = ktime_set(0, 0);
 999         }
1000
1001         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",
1002                    ws->name, active_count, ws->event_count,
1003                    ws->wakeup_count, ws->expire_count,
1004                    ktime_to_ms(active_time), ktime_to_ms(total_time),
1005                    ktime_to_ms(max_time), ktime_to_ms(ws->last_time),
1006                    ktime_to_ms(prevent_sleep_time));
1007
1008         spin_unlock_irqrestore(&ws->lock, flags);
1009
1010         return 0;
1011 }
1012
1013 /**
1014  * wakeup_sources_stats_show - Print wakeup sources statistics information.
1015  * @m: seq_file to print the statistics into.
1016  */
1017 static int wakeup_sources_stats_show(struct seq_file *m, void *unused)
1018 {
1019         struct wakeup_source *ws;
1020
1021         seq_puts(m, "name\t\tactive_count\tevent_count\twakeup_count\t"
1022                 "expire_count\tactive_since\ttotal_time\tmax_time\t"
1023                 "last_change\tprevent_suspend_time\n");
1024
1025         rcu_read_lock();
1026         list_for_each_entry_rcu(ws, &wakeup_sources, entry)
1027                 print_wakeup_source_stats(m, ws);
1028         rcu_read_unlock();
1029
1030         print_wakeup_source_stats(m, &deleted_ws);
1031
1032         return 0;
1033 }
1034
1035 static int wakeup_sources_stats_open(struct inode *inode, struct file *file)
1036 {
1037         return single_open(file, wakeup_sources_stats_show, NULL);
1038 }
1039
1040 static const struct file_operations wakeup_sources_stats_fops = {
1041         .owner = THIS_MODULE,
1042         .open = wakeup_sources_stats_open,
1043         .read = seq_read,
1044         .llseek = seq_lseek,
1045         .release = single_release,
1046 };
1047
1048 static int __init wakeup_sources_debugfs_init(void)
1049 {
1050         wakeup_sources_stats_dentry = debugfs_create_file("wakeup_sources",
1051                         S_IRUGO, NULL, NULL, &wakeup_sources_stats_fops);
1052         return 0;
1053 }
1054
1055 postcore_initcall(wakeup_sources_debugfs_init);