include/linux/wait.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _LINUX_WAIT_H
   3 #define _LINUX_WAIT_H
   4 /*
   5  * Linux wait queue related types and methods
   6  */
   7 #include <linux/list.h>
   8 #include <linux/stddef.h>
   9 #include <linux/spinlock.h>
  10
  11 #include <asm/current.h>
  12 #include <uapi/linux/wait.h>
  13
  14 typedef struct wait_queue_entry wait_queue_entry_t;
  15
  16 typedef int (*wait_queue_func_t)(struct wait_queue_entry *wq_entry, unsigned mode, int flags, void *key);
  17 int default_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int flags, void *key);
  18
  19 /* wait_queue_entry::flags */
  20 #define WQ_FLAG_EXCLUSIVE       0x01
  21 #define WQ_FLAG_WOKEN           0x02
  22 #define WQ_FLAG_BOOKMARK        0x04
  23 #define WQ_FLAG_CUSTOM          0x08
  24
  25 /*
  26  * A single wait-queue entry structure:
  27  */
  28 struct wait_queue_entry {
  29         unsigned int            flags;
  30         void                    *private;
  31         wait_queue_func_t       func;
  32         struct list_head        entry;
  33 };
  34
  35 struct wait_queue_head {
  36         spinlock_t              lock;
  37         struct list_head        head;
  38 };
  39 typedef struct wait_queue_head wait_queue_head_t;
  40
  41 struct task_struct;
  42
  43 /*
  44  * Macros for declaration and initialisaton of the datatypes
  45  */
  46
  47 #define __WAITQUEUE_INITIALIZER(name, tsk) {                                    \
  48         .private        = tsk,                                                  \
  49         .func           = default_wake_function,                                \
  50         .entry          = { NULL, NULL } }
  51
  52 #define DECLARE_WAITQUEUE(name, tsk)                                            \
  53         struct wait_queue_entry name = __WAITQUEUE_INITIALIZER(name, tsk)
  54
  55 #define __WAIT_QUEUE_HEAD_INITIALIZER(name) {                                   \
  56         .lock           = __SPIN_LOCK_UNLOCKED(name.lock),                      \
  57         .head           = { &(name).head, &(name).head } }
  58
  59 #define DECLARE_WAIT_QUEUE_HEAD(name) \
  60         struct wait_queue_head name = __WAIT_QUEUE_HEAD_INITIALIZER(name)
  61
  62 extern void __init_waitqueue_head(struct wait_queue_head *wq_head, const char *name, struct lock_class_key *);
  63
  64 #define init_waitqueue_head(wq_head)                                            \
  65         do {                                                                    \
  66                 static struct lock_class_key __key;                             \
  67                                                                                 \
  68                 __init_waitqueue_head((wq_head), #wq_head, &__key);             \
  69         } while (0)
  70
  71 #ifdef CONFIG_LOCKDEP
  72 # define __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) \
  73         ({ init_waitqueue_head(&name); name; })
  74 # define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) \
  75         struct wait_queue_head name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name)
  76 #else
  77 # define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) DECLARE_WAIT_QUEUE_HEAD(name)
  78 #endif
  79
  80 static inline void init_waitqueue_entry(struct wait_queue_entry *wq_entry, struct task_struct *p)
  81 {
  82         wq_entry->flags         = 0;
  83         wq_entry->private       = p;
  84         wq_entry->func          = default_wake_function;
  85 }
  86
  87 static inline void
  88 init_waitqueue_func_entry(struct wait_queue_entry *wq_entry, wait_queue_func_t func)
  89 {
  90         wq_entry->flags         = 0;
  91         wq_entry->private       = NULL;
  92         wq_entry->func          = func;
  93 }
  94
  95 /**
  96  * waitqueue_active -- locklessly test for waiters on the queue
  97  * @wq_head: the waitqueue to test for waiters
  98  *
  99  * returns true if the wait list is not empty
 100  *
 101  * NOTE: this function is lockless and requires care, incorrect usage _will_
 102  * lead to sporadic and non-obvious failure.
 103  *
 104  * Use either while holding wait_queue_head::lock or when used for wakeups
 105  * with an extra smp_mb() like::
 106  *
 107  *      CPU0 - waker                    CPU1 - waiter
 108  *
 109  *                                      for (;;) {
 110  *      @cond = true;                     prepare_to_wait(&wq_head, &wait, state);
 111  *      smp_mb();                         // smp_mb() from set_current_state()
 112  *      if (waitqueue_active(wq_head))         if (@cond)
 113  *        wake_up(wq_head);                      break;
 114  *                                        schedule();
 115  *                                      }
 116  *                                      finish_wait(&wq_head, &wait);
 117  *
 118  * Because without the explicit smp_mb() it's possible for the
 119  * waitqueue_active() load to get hoisted over the @cond store such that we'll
 120  * observe an empty wait list while the waiter might not observe @cond.
 121  *
 122  * Also note that this 'optimization' trades a spin_lock() for an smp_mb(),
 123  * which (when the lock is uncontended) are of roughly equal cost.
 124  */
 125 static inline int waitqueue_active(struct wait_queue_head *wq_head)
 126 {
 127         return !list_empty(&wq_head->head);
 128 }
 129
 130 /**
 131  * wq_has_single_sleeper - check if there is only one sleeper
 132  * @wq_head: wait queue head
 133  *
 134  * Returns true of wq_head has only one sleeper on the list.
 135  *
 136  * Please refer to the comment for waitqueue_active.
 137  */
 138 static inline bool wq_has_single_sleeper(struct wait_queue_head *wq_head)
 139 {
 140         return list_is_singular(&wq_head->head);
 141 }
 142
 143 /**
 144  * wq_has_sleeper - check if there are any waiting processes
 145  * @wq_head: wait queue head
 146  *
 147  * Returns true if wq_head has waiting processes
 148  *
 149  * Please refer to the comment for waitqueue_active.
 150  */
 151 static inline bool wq_has_sleeper(struct wait_queue_head *wq_head)
 152 {
 153         /*
 154          * We need to be sure we are in sync with the
 155          * add_wait_queue modifications to the wait queue.
 156          *
 157          * This memory barrier should be paired with one on the
 158          * waiting side.
 159          */
 160         smp_mb();
 161         return waitqueue_active(wq_head);
 162 }
 163
 164 extern void add_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);
 165 extern void add_wait_queue_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);
 166 extern void remove_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);
 167
 168 static inline void __add_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
 169 {
 170         list_add(&wq_entry->entry, &wq_head->head);
 171 }
 172
 173 /*
 174  * Used for wake-one threads:
 175  */
 176 static inline void
 177 __add_wait_queue_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
 178 {
 179         wq_entry->flags |= WQ_FLAG_EXCLUSIVE;
 180         __add_wait_queue(wq_head, wq_entry);
 181 }
 182
 183 static inline void __add_wait_queue_entry_tail(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
 184 {
 185         list_add_tail(&wq_entry->entry, &wq_head->head);
 186 }
 187
 188 static inline void
 189 __add_wait_queue_entry_tail_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
 190 {
 191         wq_entry->flags |= WQ_FLAG_EXCLUSIVE;
 192         __add_wait_queue_entry_tail(wq_head, wq_entry);
 193 }
 194
 195 static inline void
 196 __remove_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
 197 {
 198         list_del(&wq_entry->entry);
 199 }
 200
 201 void __wake_up(struct wait_queue_head *wq_head, unsigned int mode, int nr, void *key);
 202 void __wake_up_locked_key(struct wait_queue_head *wq_head, unsigned int mode, void *key);
 203 void __wake_up_locked_key_bookmark(struct wait_queue_head *wq_head,
 204                 unsigned int mode, void *key, wait_queue_entry_t *bookmark);
 205 void __wake_up_sync_key(struct wait_queue_head *wq_head, unsigned int mode, void *key);
 206 void __wake_up_locked_sync_key(struct wait_queue_head *wq_head, unsigned int mode, void *key);
 207 void __wake_up_locked(struct wait_queue_head *wq_head, unsigned int mode, int nr);
 208 void __wake_up_sync(struct wait_queue_head *wq_head, unsigned int mode);
 209
 210 #define wake_up(x)                      __wake_up(x, TASK_NORMAL, 1, NULL)
 211 #define wake_up_nr(x, nr)               __wake_up(x, TASK_NORMAL, nr, NULL)
 212 #define wake_up_all(x)                  __wake_up(x, TASK_NORMAL, 0, NULL)
 213 #define wake_up_locked(x)               __wake_up_locked((x), TASK_NORMAL, 1)
 214 #define wake_up_all_locked(x)           __wake_up_locked((x), TASK_NORMAL, 0)
 215
 216 #define wake_up_interruptible(x)        __wake_up(x, TASK_INTERRUPTIBLE, 1, NULL)
 217 #define wake_up_interruptible_nr(x, nr) __wake_up(x, TASK_INTERRUPTIBLE, nr, NULL)
 218 #define wake_up_interruptible_all(x)    __wake_up(x, TASK_INTERRUPTIBLE, 0, NULL)
 219 #define wake_up_interruptible_sync(x)   __wake_up_sync((x), TASK_INTERRUPTIBLE)
 220
 221 /*
 222  * Wakeup macros to be used to report events to the targets.
 223  */
 224 #define poll_to_key(m) ((void *)(__force uintptr_t)(__poll_t)(m))
 225 #define key_to_poll(m) ((__force __poll_t)(uintptr_t)(void *)(m))
 226 #define wake_up_poll(x, m)                                                      \
 227         __wake_up(x, TASK_NORMAL, 1, poll_to_key(m))
 228 #define wake_up_locked_poll(x, m)                                               \
 229         __wake_up_locked_key((x), TASK_NORMAL, poll_to_key(m))
 230 #define wake_up_interruptible_poll(x, m)                                        \
 231         __wake_up(x, TASK_INTERRUPTIBLE, 1, poll_to_key(m))
 232 #define wake_up_interruptible_sync_poll(x, m)                                   \
 233         __wake_up_sync_key((x), TASK_INTERRUPTIBLE, poll_to_key(m))
 234 #define wake_up_interruptible_sync_poll_locked(x, m)                            \
 235         __wake_up_locked_sync_key((x), TASK_INTERRUPTIBLE, poll_to_key(m))
 236
 237 #define ___wait_cond_timeout(condition)                                         \
 238 ({                                                                              \
 239         bool __cond = (condition);                                              \
 240         if (__cond && !__ret)                                                   \
 241                 __ret = 1;                                                      \
 242         __cond || !__ret;                                                       \
 243 })
 244
 245 #define ___wait_is_interruptible(state)                                         \
 246         (!__builtin_constant_p(state) ||                                        \
 247                 state == TASK_INTERRUPTIBLE || state == TASK_KILLABLE)          \
 248
 249 extern void init_wait_entry(struct wait_queue_entry *wq_entry, int flags);
 250
 251 /*
 252  * The below macro ___wait_event() has an explicit shadow of the __ret
 253  * variable when used from the wait_event_*() macros.
 254  *
 255  * This is so that both can use the ___wait_cond_timeout() construct
 256  * to wrap the condition.
 257  *
 258  * The type inconsistency of the wait_event_*() __ret variable is also
 259  * on purpose; we use long where we can return timeout values and int
 260  * otherwise.
 261  */
 262
 263 #define ___wait_event(wq_head, condition, state, exclusive, ret, cmd)           \
 264 ({                                                                              \
 265         __label__ __out;                                                        \
 266         struct wait_queue_entry __wq_entry;                                     \
 267         long __ret = ret;       /* explicit shadow */                           \
 268                                                                                 \
 269         init_wait_entry(&__wq_entry, exclusive ? WQ_FLAG_EXCLUSIVE : 0);        \
 270         for (;;) {                                                              \
 271                 long __int = prepare_to_wait_event(&wq_head, &__wq_entry, state);\
 272                                                                                 \
 273                 if (condition)                                                  \
 274                         break;                                                  \
 275                                                                                 \
 276                 if (___wait_is_interruptible(state) && __int) {                 \
 277                         __ret = __int;                                          \
 278                         goto __out;                                             \
 279                 }                                                               \
 280                                                                                 \
 281                 cmd;                                                            \
 282         }                                                                       \
 283         finish_wait(&wq_head, &__wq_entry);                                     \
 284 __out:  __ret;                                                                  \
 285 })
 286
 287 #define __wait_event(wq_head, condition)                                        \
 288         (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0,     \
 289                             schedule())
 290
 291 /**
 292  * wait_event - sleep until a condition gets true
 293  * @wq_head: the waitqueue to wait on
 294  * @condition: a C expression for the event to wait for
 295  *
 296  * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
 297  * @condition evaluates to true. The @condition is checked each time
 298  * the waitqueue @wq_head is woken up.
 299  *
 300  * wake_up() has to be called after changing any variable that could
 301  * change the result of the wait condition.
 302  */
 303 #define wait_event(wq_head, condition)                                          \
 304 do {                                                                            \
 305         might_sleep();                                                          \
 306         if (condition)                                                          \
 307                 break;                                                          \
 308         __wait_event(wq_head, condition);                                       \
 309 } while (0)
 310
 311 #define __io_wait_event(wq_head, condition)                                     \
 312         (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0,     \
 313                             io_schedule())
 314
 315 /*
 316  * io_wait_event() -- like wait_event() but with io_schedule()
 317  */
 318 #define io_wait_event(wq_head, condition)                                       \
 319 do {                                                                            \
 320         might_sleep();                                                          \
 321         if (condition)                                                          \
 322                 break;                                                          \
 323         __io_wait_event(wq_head, condition);                                    \
 324 } while (0)
 325
 326 #define __wait_event_freezable(wq_head, condition)                              \
 327         ___wait_event(wq_head, condition, TASK_INTERRUPTIBLE, 0, 0,             \
 328                             freezable_schedule())
 329
 330 /**
 331  * wait_event_freezable - sleep (or freeze) until a condition gets true
 332  * @wq_head: the waitqueue to wait on
 333  * @condition: a C expression for the event to wait for
 334  *
 335  * The process is put to sleep (TASK_INTERRUPTIBLE -- so as not to contribute
 336  * to system load) until the @condition evaluates to true. The
 337  * @condition is checked each time the waitqueue @wq_head is woken up.
 338  *
 339  * wake_up() has to be called after changing any variable that could
 340  * change the result of the wait condition.
 341  */
 342 #define wait_event_freezable(wq_head, condition)                                \
 343 ({                                                                              \
 344         int __ret = 0;                                                          \
 345         might_sleep();                                                          \
 346         if (!(condition))                                                       \
 347                 __ret = __wait_event_freezable(wq_head, condition);             \
 348         __ret;                                                                  \
 349 })
 350
 351 #define __wait_event_timeout(wq_head, condition, timeout)                       \
 352         ___wait_event(wq_head, ___wait_cond_timeout(condition),                 \
 353                       TASK_UNINTERRUPTIBLE, 0, timeout,                         \
 354                       __ret = schedule_timeout(__ret))
 355
 356 /**
 357  * wait_event_timeout - sleep until a condition gets true or a timeout elapses
 358  * @wq_head: the waitqueue to wait on
 359  * @condition: a C expression for the event to wait for
 360  * @timeout: timeout, in jiffies
 361  *
 362  * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
 363  * @condition evaluates to true. The @condition is checked each time
 364  * the waitqueue @wq_head is woken up.
 365  *
 366  * wake_up() has to be called after changing any variable that could
 367  * change the result of the wait condition.
 368  *
 369  * Returns:
 370  * 0 if the @condition evaluated to %false after the @timeout elapsed,
 371  * 1 if the @condition evaluated to %true after the @timeout elapsed,
 372  * or the remaining jiffies (at least 1) if the @condition evaluated
 373  * to %true before the @timeout elapsed.
 374  */
 375 #define wait_event_timeout(wq_head, condition, timeout)                         \
 376 ({                                                                              \
 377         long __ret = timeout;                                                   \
 378         might_sleep();                                                          \
 379         if (!___wait_cond_timeout(condition))                                   \
 380                 __ret = __wait_event_timeout(wq_head, condition, timeout);      \
 381         __ret;                                                                  \
 382 })
 383
 384 #define __wait_event_freezable_timeout(wq_head, condition, timeout)             \
 385         ___wait_event(wq_head, ___wait_cond_timeout(condition),                 \
 386                       TASK_INTERRUPTIBLE, 0, timeout,                           \
 387                       __ret = freezable_schedule_timeout(__ret))
 388
 389 /*
 390  * like wait_event_timeout() -- except it uses TASK_INTERRUPTIBLE to avoid
 391  * increasing load and is freezable.
 392  */
 393 #define wait_event_freezable_timeout(wq_head, condition, timeout)               \
 394 ({                                                                              \
 395         long __ret = timeout;                                                   \
 396         might_sleep();                                                          \
 397         if (!___wait_cond_timeout(condition))                                   \
 398                 __ret = __wait_event_freezable_timeout(wq_head, condition, timeout); \
 399         __ret;                                                                  \
 400 })
 401
 402 #define __wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2)              \
 403         (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 1, 0,     \
 404                             cmd1; schedule(); cmd2)
 405 /*
 406  * Just like wait_event_cmd(), except it sets exclusive flag
 407  */
 408 #define wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2)                \
 409 do {                                                                            \
 410         if (condition)                                                          \
 411                 break;                                                          \
 412         __wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2);             \
 413 } while (0)
 414
 415 #define __wait_event_cmd(wq_head, condition, cmd1, cmd2)                        \
 416         (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0,     \
 417                             cmd1; schedule(); cmd2)
 418
 419 /**
 420  * wait_event_cmd - sleep until a condition gets true
 421  * @wq_head: the waitqueue to wait on
 422  * @condition: a C expression for the event to wait for
 423  * @cmd1: the command will be executed before sleep
 424  * @cmd2: the command will be executed after sleep
 425  *
 426  * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
 427  * @condition evaluates to true. The @condition is checked each time
 428  * the waitqueue @wq_head is woken up.
 429  *
 430  * wake_up() has to be called after changing any variable that could
 431  * change the result of the wait condition.
 432  */
 433 #define wait_event_cmd(wq_head, condition, cmd1, cmd2)                          \
 434 do {                                                                            \
 435         if (condition)                                                          \
 436                 break;                                                          \
 437         __wait_event_cmd(wq_head, condition, cmd1, cmd2);                       \
 438 } while (0)
 439
 440 #define __wait_event_interruptible(wq_head, condition)                          \
 441         ___wait_event(wq_head, condition, TASK_INTERRUPTIBLE, 0, 0,             \
 442                       schedule())
 443
 444 /**
 445  * wait_event_interruptible - sleep until a condition gets true
 446  * @wq_head: the waitqueue to wait on
 447  * @condition: a C expression for the event to wait for
 448  *
 449  * The process is put to sleep (TASK_INTERRUPTIBLE) until the
 450  * @condition evaluates to true or a signal is received.
 451  * The @condition is checked each time the waitqueue @wq_head is woken up.
 452  *
 453  * wake_up() has to be called after changing any variable that could
 454  * change the result of the wait condition.
 455  *
 456  * The function will return -ERESTARTSYS if it was interrupted by a
 457  * signal and 0 if @condition evaluated to true.
 458  */
 459 #define wait_event_interruptible(wq_head, condition)                            \
 460 ({                                                                              \
 461         int __ret = 0;                                                          \
 462         might_sleep();                                                          \
 463         if (!(condition))                                                       \
 464                 __ret = __wait_event_interruptible(wq_head, condition);         \
 465         __ret;                                                                  \
 466 })
 467
 468 #define __wait_event_interruptible_timeout(wq_head, condition, timeout)         \
 469         ___wait_event(wq_head, ___wait_cond_timeout(condition),                 \
 470                       TASK_INTERRUPTIBLE, 0, timeout,                           \
 471                       __ret = schedule_timeout(__ret))
 472
 473 /**
 474  * wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses
 475  * @wq_head: the waitqueue to wait on
 476  * @condition: a C expression for the event to wait for
 477  * @timeout: timeout, in jiffies
 478  *
 479  * The process is put to sleep (TASK_INTERRUPTIBLE) until the
 480  * @condition evaluates to true or a signal is received.
 481  * The @condition is checked each time the waitqueue @wq_head is woken up.
 482  *
 483  * wake_up() has to be called after changing any variable that could
 484  * change the result of the wait condition.
 485  *
 486  * Returns:
 487  * 0 if the @condition evaluated to %false after the @timeout elapsed,
 488  * 1 if the @condition evaluated to %true after the @timeout elapsed,
 489  * the remaining jiffies (at least 1) if the @condition evaluated
 490  * to %true before the @timeout elapsed, or -%ERESTARTSYS if it was
 491  * interrupted by a signal.
 492  */
 493 #define wait_event_interruptible_timeout(wq_head, condition, timeout)           \
 494 ({                                                                              \
 495         long __ret = timeout;                                                   \
 496         might_sleep();                                                          \
 497         if (!___wait_cond_timeout(condition))                                   \
 498                 __ret = __wait_event_interruptible_timeout(wq_head,             \
 499                                                 condition, timeout);            \
 500         __ret;                                                                  \
 501 })
 502
 503 #define __wait_event_hrtimeout(wq_head, condition, timeout, state)              \
 504 ({                                                                              \
 505         int __ret = 0;                                                          \
 506         struct hrtimer_sleeper __t;                                             \
 507                                                                                 \
 508         hrtimer_init_sleeper_on_stack(&__t, CLOCK_MONOTONIC,                    \
 509                                       HRTIMER_MODE_REL);                        \
 510         if ((timeout) != KTIME_MAX)                                             \
 511                 hrtimer_start_range_ns(&__t.timer, timeout,                     \
 512                                        current->timer_slack_ns,                 \
 513                                        HRTIMER_MODE_REL);                       \
 514                                                                                 \
 515         __ret = ___wait_event(wq_head, condition, state, 0, 0,                  \
 516                 if (!__t.task) {                                                \
 517                         __ret = -ETIME;                                         \
 518                         break;                                                  \
 519                 }                                                               \
 520                 schedule());                                                    \
 521                                                                                 \
 522         hrtimer_cancel(&__t.timer);                                             \
 523         destroy_hrtimer_on_stack(&__t.timer);                                   \
 524         __ret;                                                                  \
 525 })
 526
 527 /**
 528  * wait_event_hrtimeout - sleep until a condition gets true or a timeout elapses
 529  * @wq_head: the waitqueue to wait on
 530  * @condition: a C expression for the event to wait for
 531  * @timeout: timeout, as a ktime_t
 532  *
 533  * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
 534  * @condition evaluates to true or a signal is received.
 535  * The @condition is checked each time the waitqueue @wq_head is woken up.
 536  *
 537  * wake_up() has to be called after changing any variable that could
 538  * change the result of the wait condition.
 539  *
 540  * The function returns 0 if @condition became true, or -ETIME if the timeout
 541  * elapsed.
 542  */
 543 #define wait_event_hrtimeout(wq_head, condition, timeout)                       \
 544 ({                                                                              \
 545         int __ret = 0;                                                          \
 546         might_sleep();                                                          \
 547         if (!(condition))                                                       \
 548                 __ret = __wait_event_hrtimeout(wq_head, condition, timeout,     \
 549                                                TASK_UNINTERRUPTIBLE);           \
 550         __ret;                                                                  \
 551 })
 552
 553 /**
 554  * wait_event_interruptible_hrtimeout - sleep until a condition gets true or a timeout elapses
 555  * @wq: the waitqueue to wait on
 556  * @condition: a C expression for the event to wait for
 557  * @timeout: timeout, as a ktime_t
 558  *
 559  * The process is put to sleep (TASK_INTERRUPTIBLE) until the
 560  * @condition evaluates to true or a signal is received.
 561  * The @condition is checked each time the waitqueue @wq is woken up.
 562  *
 563  * wake_up() has to be called after changing any variable that could
 564  * change the result of the wait condition.
 565  *
 566  * The function returns 0 if @condition became true, -ERESTARTSYS if it was
 567  * interrupted by a signal, or -ETIME if the timeout elapsed.
 568  */
 569 #define wait_event_interruptible_hrtimeout(wq, condition, timeout)              \
 570 ({                                                                              \
 571         long __ret = 0;                                                         \
 572         might_sleep();                                                          \
 573         if (!(condition))                                                       \
 574                 __ret = __wait_event_hrtimeout(wq, condition, timeout,          \
 575                                                TASK_INTERRUPTIBLE);             \
 576         __ret;                                                                  \
 577 })
 578
 579 #define __wait_event_interruptible_exclusive(wq, condition)                     \
 580         ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, 0,                  \
 581                       schedule())
 582
 583 #define wait_event_interruptible_exclusive(wq, condition)                       \
 584 ({                                                                              \
 585         int __ret = 0;                                                          \
 586         might_sleep();                                                          \
 587         if (!(condition))                                                       \
 588                 __ret = __wait_event_interruptible_exclusive(wq, condition);    \
 589         __ret;                                                                  \
 590 })
 591
 592 #define __wait_event_killable_exclusive(wq, condition)                          \
 593         ___wait_event(wq, condition, TASK_KILLABLE, 1, 0,                       \
 594                       schedule())
 595
 596 #define wait_event_killable_exclusive(wq, condition)                            \
 597 ({                                                                              \
 598         int __ret = 0;                                                          \
 599         might_sleep();                                                          \
 600         if (!(condition))                                                       \
 601                 __ret = __wait_event_killable_exclusive(wq, condition);         \
 602         __ret;                                                                  \
 603 })
 604
 605
 606 #define __wait_event_freezable_exclusive(wq, condition)                         \
 607         ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, 0,                  \
 608                         freezable_schedule())
 609
 610 #define wait_event_freezable_exclusive(wq, condition)                           \
 611 ({                                                                              \
 612         int __ret = 0;                                                          \
 613         might_sleep();                                                          \
 614         if (!(condition))                                                       \
 615                 __ret = __wait_event_freezable_exclusive(wq, condition);        \
 616         __ret;                                                                  \
 617 })
 618
 619 /**
 620  * wait_event_idle - wait for a condition without contributing to system load
 621  * @wq_head: the waitqueue to wait on
 622  * @condition: a C expression for the event to wait for
 623  *
 624  * The process is put to sleep (TASK_IDLE) until the
 625  * @condition evaluates to true.
 626  * The @condition is checked each time the waitqueue @wq_head is woken up.
 627  *
 628  * wake_up() has to be called after changing any variable that could
 629  * change the result of the wait condition.
 630  *
 631  */
 632 #define wait_event_idle(wq_head, condition)                                     \
 633 do {                                                                            \
 634         might_sleep();                                                          \
 635         if (!(condition))                                                       \
 636                 ___wait_event(wq_head, condition, TASK_IDLE, 0, 0, schedule()); \
 637 } while (0)
 638
 639 /**
 640  * wait_event_idle_exclusive - wait for a condition with contributing to system load
 641  * @wq_head: the waitqueue to wait on
 642  * @condition: a C expression for the event to wait for
 643  *
 644  * The process is put to sleep (TASK_IDLE) until the
 645  * @condition evaluates to true.
 646  * The @condition is checked each time the waitqueue @wq_head is woken up.
 647  *
 648  * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
 649  * set thus if other processes wait on the same list, when this
 650  * process is woken further processes are not considered.
 651  *
 652  * wake_up() has to be called after changing any variable that could
 653  * change the result of the wait condition.
 654  *
 655  */
 656 #define wait_event_idle_exclusive(wq_head, condition)                           \
 657 do {                                                                            \
 658         might_sleep();                                                          \
 659         if (!(condition))                                                       \
 660                 ___wait_event(wq_head, condition, TASK_IDLE, 1, 0, schedule()); \
 661 } while (0)
 662
 663 #define __wait_event_idle_timeout(wq_head, condition, timeout)                  \
 664         ___wait_event(wq_head, ___wait_cond_timeout(condition),                 \
 665                       TASK_IDLE, 0, timeout,                                    \
 666                       __ret = schedule_timeout(__ret))
 667
 668 /**
 669  * wait_event_idle_timeout - sleep without load until a condition becomes true or a timeout elapses
 670  * @wq_head: the waitqueue to wait on
 671  * @condition: a C expression for the event to wait for
 672  * @timeout: timeout, in jiffies
 673  *
 674  * The process is put to sleep (TASK_IDLE) until the
 675  * @condition evaluates to true. The @condition is checked each time
 676  * the waitqueue @wq_head is woken up.
 677  *
 678  * wake_up() has to be called after changing any variable that could
 679  * change the result of the wait condition.
 680  *
 681  * Returns:
 682  * 0 if the @condition evaluated to %false after the @timeout elapsed,
 683  * 1 if the @condition evaluated to %true after the @timeout elapsed,
 684  * or the remaining jiffies (at least 1) if the @condition evaluated
 685  * to %true before the @timeout elapsed.
 686  */
 687 #define wait_event_idle_timeout(wq_head, condition, timeout)                    \
 688 ({                                                                              \
 689         long __ret = timeout;                                                   \
 690         might_sleep();                                                          \
 691         if (!___wait_cond_timeout(condition))                                   \
 692                 __ret = __wait_event_idle_timeout(wq_head, condition, timeout); \
 693         __ret;                                                                  \
 694 })
 695
 696 #define __wait_event_idle_exclusive_timeout(wq_head, condition, timeout)        \
 697         ___wait_event(wq_head, ___wait_cond_timeout(condition),                 \
 698                       TASK_IDLE, 1, timeout,                                    \
 699                       __ret = schedule_timeout(__ret))
 700
 701 /**
 702  * wait_event_idle_exclusive_timeout - sleep without load until a condition becomes true or a timeout elapses
 703  * @wq_head: the waitqueue to wait on
 704  * @condition: a C expression for the event to wait for
 705  * @timeout: timeout, in jiffies
 706  *
 707  * The process is put to sleep (TASK_IDLE) until the
 708  * @condition evaluates to true. The @condition is checked each time
 709  * the waitqueue @wq_head is woken up.
 710  *
 711  * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
 712  * set thus if other processes wait on the same list, when this
 713  * process is woken further processes are not considered.
 714  *
 715  * wake_up() has to be called after changing any variable that could
 716  * change the result of the wait condition.
 717  *
 718  * Returns:
 719  * 0 if the @condition evaluated to %false after the @timeout elapsed,
 720  * 1 if the @condition evaluated to %true after the @timeout elapsed,
 721  * or the remaining jiffies (at least 1) if the @condition evaluated
 722  * to %true before the @timeout elapsed.
 723  */
 724 #define wait_event_idle_exclusive_timeout(wq_head, condition, timeout)          \
 725 ({                                                                              \
 726         long __ret = timeout;                                                   \
 727         might_sleep();                                                          \
 728         if (!___wait_cond_timeout(condition))                                   \
 729                 __ret = __wait_event_idle_exclusive_timeout(wq_head, condition, timeout);\
 730         __ret;                                                                  \
 731 })
 732
 733 extern int do_wait_intr(wait_queue_head_t *, wait_queue_entry_t *);
 734 extern int do_wait_intr_irq(wait_queue_head_t *, wait_queue_entry_t *);
 735
 736 #define __wait_event_interruptible_locked(wq, condition, exclusive, fn)         \
 737 ({                                                                              \
 738         int __ret;                                                              \
 739         DEFINE_WAIT(__wait);                                                    \
 740         if (exclusive)                                                          \
 741                 __wait.flags |= WQ_FLAG_EXCLUSIVE;                              \
 742         do {                                                                    \
 743                 __ret = fn(&(wq), &__wait);                                     \
 744                 if (__ret)                                                      \
 745                         break;                                                  \
 746         } while (!(condition));                                                 \
 747         __remove_wait_queue(&(wq), &__wait);                                    \
 748         __set_current_state(TASK_RUNNING);                                      \
 749         __ret;                                                                  \
 750 })
 751
 752
 753 /**
 754  * wait_event_interruptible_locked - sleep until a condition gets true
 755  * @wq: the waitqueue to wait on
 756  * @condition: a C expression for the event to wait for
 757  *
 758  * The process is put to sleep (TASK_INTERRUPTIBLE) until the
 759  * @condition evaluates to true or a signal is received.
 760  * The @condition is checked each time the waitqueue @wq is woken up.
 761  *
 762  * It must be called with wq.lock being held.  This spinlock is
 763  * unlocked while sleeping but @condition testing is done while lock
 764  * is held and when this macro exits the lock is held.
 765  *
 766  * The lock is locked/unlocked using spin_lock()/spin_unlock()
 767  * functions which must match the way they are locked/unlocked outside
 768  * of this macro.
 769  *
 770  * wake_up_locked() has to be called after changing any variable that could
 771  * change the result of the wait condition.
 772  *
 773  * The function will return -ERESTARTSYS if it was interrupted by a
 774  * signal and 0 if @condition evaluated to true.
 775  */
 776 #define wait_event_interruptible_locked(wq, condition)                          \
 777         ((condition)                                                            \
 778          ? 0 : __wait_event_interruptible_locked(wq, condition, 0, do_wait_intr))
 779
 780 /**
 781  * wait_event_interruptible_locked_irq - sleep until a condition gets true
 782  * @wq: the waitqueue to wait on
 783  * @condition: a C expression for the event to wait for
 784  *
 785  * The process is put to sleep (TASK_INTERRUPTIBLE) until the
 786  * @condition evaluates to true or a signal is received.
 787  * The @condition is checked each time the waitqueue @wq is woken up.
 788  *
 789  * It must be called with wq.lock being held.  This spinlock is
 790  * unlocked while sleeping but @condition testing is done while lock
 791  * is held and when this macro exits the lock is held.
 792  *
 793  * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq()
 794  * functions which must match the way they are locked/unlocked outside
 795  * of this macro.
 796  *
 797  * wake_up_locked() has to be called after changing any variable that could
 798  * change the result of the wait condition.
 799  *
 800  * The function will return -ERESTARTSYS if it was interrupted by a
 801  * signal and 0 if @condition evaluated to true.
 802  */
 803 #define wait_event_interruptible_locked_irq(wq, condition)                      \
 804         ((condition)                                                            \
 805          ? 0 : __wait_event_interruptible_locked(wq, condition, 0, do_wait_intr_irq))
 806
 807 /**
 808  * wait_event_interruptible_exclusive_locked - sleep exclusively until a condition gets true
 809  * @wq: the waitqueue to wait on
 810  * @condition: a C expression for the event to wait for
 811  *
 812  * The process is put to sleep (TASK_INTERRUPTIBLE) until the
 813  * @condition evaluates to true or a signal is received.
 814  * The @condition is checked each time the waitqueue @wq is woken up.
 815  *
 816  * It must be called with wq.lock being held.  This spinlock is
 817  * unlocked while sleeping but @condition testing is done while lock
 818  * is held and when this macro exits the lock is held.
 819  *
 820  * The lock is locked/unlocked using spin_lock()/spin_unlock()
 821  * functions which must match the way they are locked/unlocked outside
 822  * of this macro.
 823  *
 824  * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
 825  * set thus when other process waits process on the list if this
 826  * process is awaken further processes are not considered.
 827  *
 828  * wake_up_locked() has to be called after changing any variable that could
 829  * change the result of the wait condition.
 830  *
 831  * The function will return -ERESTARTSYS if it was interrupted by a
 832  * signal and 0 if @condition evaluated to true.
 833  */
 834 #define wait_event_interruptible_exclusive_locked(wq, condition)                \
 835         ((condition)                                                            \
 836          ? 0 : __wait_event_interruptible_locked(wq, condition, 1, do_wait_intr))
 837
 838 /**
 839  * wait_event_interruptible_exclusive_locked_irq - sleep until a condition gets true
 840  * @wq: the waitqueue to wait on
 841  * @condition: a C expression for the event to wait for
 842  *
 843  * The process is put to sleep (TASK_INTERRUPTIBLE) until the
 844  * @condition evaluates to true or a signal is received.
 845  * The @condition is checked each time the waitqueue @wq is woken up.
 846  *
 847  * It must be called with wq.lock being held.  This spinlock is
 848  * unlocked while sleeping but @condition testing is done while lock
 849  * is held and when this macro exits the lock is held.
 850  *
 851  * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq()
 852  * functions which must match the way they are locked/unlocked outside
 853  * of this macro.
 854  *
 855  * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
 856  * set thus when other process waits process on the list if this
 857  * process is awaken further processes are not considered.
 858  *
 859  * wake_up_locked() has to be called after changing any variable that could
 860  * change the result of the wait condition.
 861  *
 862  * The function will return -ERESTARTSYS if it was interrupted by a
 863  * signal and 0 if @condition evaluated to true.
 864  */
 865 #define wait_event_interruptible_exclusive_locked_irq(wq, condition)            \
 866         ((condition)                                                            \
 867          ? 0 : __wait_event_interruptible_locked(wq, condition, 1, do_wait_intr_irq))
 868
 869
 870 #define __wait_event_killable(wq, condition)                                    \
 871         ___wait_event(wq, condition, TASK_KILLABLE, 0, 0, schedule())
 872
 873 /**
 874  * wait_event_killable - sleep until a condition gets true
 875  * @wq_head: the waitqueue to wait on
 876  * @condition: a C expression for the event to wait for
 877  *
 878  * The process is put to sleep (TASK_KILLABLE) until the
 879  * @condition evaluates to true or a signal is received.
 880  * The @condition is checked each time the waitqueue @wq_head is woken up.
 881  *
 882  * wake_up() has to be called after changing any variable that could
 883  * change the result of the wait condition.
 884  *
 885  * The function will return -ERESTARTSYS if it was interrupted by a
 886  * signal and 0 if @condition evaluated to true.
 887  */
 888 #define wait_event_killable(wq_head, condition)                                 \
 889 ({                                                                              \
 890         int __ret = 0;                                                          \
 891         might_sleep();                                                          \
 892         if (!(condition))                                                       \
 893                 __ret = __wait_event_killable(wq_head, condition);              \
 894         __ret;                                                                  \
 895 })
 896
 897 #define __wait_event_killable_timeout(wq_head, condition, timeout)              \
 898         ___wait_event(wq_head, ___wait_cond_timeout(condition),                 \
 899                       TASK_KILLABLE, 0, timeout,                                \
 900                       __ret = schedule_timeout(__ret))
 901
 902 /**
 903  * wait_event_killable_timeout - sleep until a condition gets true or a timeout elapses
 904  * @wq_head: the waitqueue to wait on
 905  * @condition: a C expression for the event to wait for
 906  * @timeout: timeout, in jiffies
 907  *
 908  * The process is put to sleep (TASK_KILLABLE) until the
 909  * @condition evaluates to true or a kill signal is received.
 910  * The @condition is checked each time the waitqueue @wq_head is woken up.
 911  *
 912  * wake_up() has to be called after changing any variable that could
 913  * change the result of the wait condition.
 914  *
 915  * Returns:
 916  * 0 if the @condition evaluated to %false after the @timeout elapsed,
 917  * 1 if the @condition evaluated to %true after the @timeout elapsed,
 918  * the remaining jiffies (at least 1) if the @condition evaluated
 919  * to %true before the @timeout elapsed, or -%ERESTARTSYS if it was
 920  * interrupted by a kill signal.
 921  *
 922  * Only kill signals interrupt this process.
 923  */
 924 #define wait_event_killable_timeout(wq_head, condition, timeout)                \
 925 ({                                                                              \
 926         long __ret = timeout;                                                   \
 927         might_sleep();                                                          \
 928         if (!___wait_cond_timeout(condition))                                   \
 929                 __ret = __wait_event_killable_timeout(wq_head,                  \
 930                                                 condition, timeout);            \
 931         __ret;                                                                  \
 932 })
 933
 934
 935 #define __wait_event_lock_irq(wq_head, condition, lock, cmd)                    \
 936         (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0,     \
 937                             spin_unlock_irq(&lock);                             \
 938                             cmd;                                                \
 939                             schedule();                                         \
 940                             spin_lock_irq(&lock))
 941
 942 /**
 943  * wait_event_lock_irq_cmd - sleep until a condition gets true. The
 944  *                           condition is checked under the lock. This
 945  *                           is expected to be called with the lock
 946  *                           taken.
 947  * @wq_head: the waitqueue to wait on
 948  * @condition: a C expression for the event to wait for
 949  * @lock: a locked spinlock_t, which will be released before cmd
 950  *        and schedule() and reacquired afterwards.
 951  * @cmd: a command which is invoked outside the critical section before
 952  *       sleep
 953  *
 954  * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
 955  * @condition evaluates to true. The @condition is checked each time
 956  * the waitqueue @wq_head is woken up.
 957  *
 958  * wake_up() has to be called after changing any variable that could
 959  * change the result of the wait condition.
 960  *
 961  * This is supposed to be called while holding the lock. The lock is
 962  * dropped before invoking the cmd and going to sleep and is reacquired
 963  * afterwards.
 964  */
 965 #define wait_event_lock_irq_cmd(wq_head, condition, lock, cmd)                  \
 966 do {                                                                            \
 967         if (condition)                                                          \
 968                 break;                                                          \
 969         __wait_event_lock_irq(wq_head, condition, lock, cmd);                   \
 970 } while (0)
 971
 972 /**
 973  * wait_event_lock_irq - sleep until a condition gets true. The
 974  *                       condition is checked under the lock. This
 975  *                       is expected to be called with the lock
 976  *                       taken.
 977  * @wq_head: the waitqueue to wait on
 978  * @condition: a C expression for the event to wait for
 979  * @lock: a locked spinlock_t, which will be released before schedule()
 980  *        and reacquired afterwards.
 981  *
 982  * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
 983  * @condition evaluates to true. The @condition is checked each time
 984  * the waitqueue @wq_head is woken up.
 985  *
 986  * wake_up() has to be called after changing any variable that could
 987  * change the result of the wait condition.
 988  *
 989  * This is supposed to be called while holding the lock. The lock is
 990  * dropped before going to sleep and is reacquired afterwards.
 991  */
 992 #define wait_event_lock_irq(wq_head, condition, lock)                           \
 993 do {                                                                            \
 994         if (condition)                                                          \
 995                 break;                                                          \
 996         __wait_event_lock_irq(wq_head, condition, lock, );                      \
 997 } while (0)
 998
 999
1000 #define __wait_event_interruptible_lock_irq(wq_head, condition, lock, cmd)      \
1001         ___wait_event(wq_head, condition, TASK_INTERRUPTIBLE, 0, 0,             \
1002                       spin_unlock_irq(&lock);                                   \
1003                       cmd;                                                      \
1004                       schedule();                                               \
1005                       spin_lock_irq(&lock))
1006
1007 /**
1008  * wait_event_interruptible_lock_irq_cmd - sleep until a condition gets true.
1009  *              The condition is checked under the lock. This is expected to
1010  *              be called with the lock taken.
1011  * @wq_head: the waitqueue to wait on
1012  * @condition: a C expression for the event to wait for
1013  * @lock: a locked spinlock_t, which will be released before cmd and
1014  *        schedule() and reacquired afterwards.
1015  * @cmd: a command which is invoked outside the critical section before
1016  *       sleep
1017  *
1018  * The process is put to sleep (TASK_INTERRUPTIBLE) until the
1019  * @condition evaluates to true or a signal is received. The @condition is
1020  * checked each time the waitqueue @wq_head is woken up.
1021  *
1022  * wake_up() has to be called after changing any variable that could
1023  * change the result of the wait condition.
1024  *
1025  * This is supposed to be called while holding the lock. The lock is
1026  * dropped before invoking the cmd and going to sleep and is reacquired
1027  * afterwards.
1028  *
1029  * The macro will return -ERESTARTSYS if it was interrupted by a signal
1030  * and 0 if @condition evaluated to true.
1031  */
1032 #define wait_event_interruptible_lock_irq_cmd(wq_head, condition, lock, cmd)    \
1033 ({                                                                              \
1034         int __ret = 0;                                                          \
1035         if (!(condition))                                                       \
1036                 __ret = __wait_event_interruptible_lock_irq(wq_head,            \
1037                                                 condition, lock, cmd);          \
1038         __ret;                                                                  \
1039 })
1040
1041 /**
1042  * wait_event_interruptible_lock_irq - sleep until a condition gets true.
1043  *              The condition is checked under the lock. This is expected
1044  *              to be called with the lock taken.
1045  * @wq_head: the waitqueue to wait on
1046  * @condition: a C expression for the event to wait for
1047  * @lock: a locked spinlock_t, which will be released before schedule()
1048  *        and reacquired afterwards.
1049  *
1050  * The process is put to sleep (TASK_INTERRUPTIBLE) until the
1051  * @condition evaluates to true or signal is received. The @condition is
1052  * checked each time the waitqueue @wq_head is woken up.
1053  *
1054  * wake_up() has to be called after changing any variable that could
1055  * change the result of the wait condition.
1056  *
1057  * This is supposed to be called while holding the lock. The lock is
1058  * dropped before going to sleep and is reacquired afterwards.
1059  *
1060  * The macro will return -ERESTARTSYS if it was interrupted by a signal
1061  * and 0 if @condition evaluated to true.
1062  */
1063 #define wait_event_interruptible_lock_irq(wq_head, condition, lock)             \
1064 ({                                                                              \
1065         int __ret = 0;                                                          \
1066         if (!(condition))                                                       \
1067                 __ret = __wait_event_interruptible_lock_irq(wq_head,            \
1068                                                 condition, lock,);              \
1069         __ret;                                                                  \
1070 })
1071
1072 #define __wait_event_lock_irq_timeout(wq_head, condition, lock, timeout, state) \
1073         ___wait_event(wq_head, ___wait_cond_timeout(condition),                 \
1074                       state, 0, timeout,                                        \
1075                       spin_unlock_irq(&lock);                                   \
1076                       __ret = schedule_timeout(__ret);                          \
1077                       spin_lock_irq(&lock));
1078
1079 /**
1080  * wait_event_interruptible_lock_irq_timeout - sleep until a condition gets
1081  *              true or a timeout elapses. The condition is checked under
1082  *              the lock. This is expected to be called with the lock taken.
1083  * @wq_head: the waitqueue to wait on
1084  * @condition: a C expression for the event to wait for
1085  * @lock: a locked spinlock_t, which will be released before schedule()
1086  *        and reacquired afterwards.
1087  * @timeout: timeout, in jiffies
1088  *
1089  * The process is put to sleep (TASK_INTERRUPTIBLE) until the
1090  * @condition evaluates to true or signal is received. The @condition is
1091  * checked each time the waitqueue @wq_head is woken up.
1092  *
1093  * wake_up() has to be called after changing any variable that could
1094  * change the result of the wait condition.
1095  *
1096  * This is supposed to be called while holding the lock. The lock is
1097  * dropped before going to sleep and is reacquired afterwards.
1098  *
1099  * The function returns 0 if the @timeout elapsed, -ERESTARTSYS if it
1100  * was interrupted by a signal, and the remaining jiffies otherwise
1101  * if the condition evaluated to true before the timeout elapsed.
1102  */
1103 #define wait_event_interruptible_lock_irq_timeout(wq_head, condition, lock,     \
1104                                                   timeout)                      \
1105 ({                                                                              \
1106         long __ret = timeout;                                                   \
1107         if (!___wait_cond_timeout(condition))                                   \
1108                 __ret = __wait_event_lock_irq_timeout(                          \
1109                                         wq_head, condition, lock, timeout,      \
1110                                         TASK_INTERRUPTIBLE);                    \
1111         __ret;                                                                  \
1112 })
1113
1114 #define wait_event_lock_irq_timeout(wq_head, condition, lock, timeout)          \
1115 ({                                                                              \
1116         long __ret = timeout;                                                   \
1117         if (!___wait_cond_timeout(condition))                                   \
1118                 __ret = __wait_event_lock_irq_timeout(                          \
1119                                         wq_head, condition, lock, timeout,      \
1120                                         TASK_UNINTERRUPTIBLE);                  \
1121         __ret;                                                                  \
1122 })
1123
1124 /*
1125  * Waitqueues which are removed from the waitqueue_head at wakeup time
1126  */
1127 void prepare_to_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);
1128 void prepare_to_wait_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);
1129 long prepare_to_wait_event(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);
1130 void finish_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);
1131 long wait_woken(struct wait_queue_entry *wq_entry, unsigned mode, long timeout);
1132 int woken_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key);
1133 int autoremove_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key);
1134
1135 #define DEFINE_WAIT_FUNC(name, function)                                        \
1136         struct wait_queue_entry name = {                                        \
1137                 .private        = current,                                      \
1138                 .func           = function,                                     \
1139                 .entry          = LIST_HEAD_INIT((name).entry),                 \
1140         }
1141
1142 #define DEFINE_WAIT(name) DEFINE_WAIT_FUNC(name, autoremove_wake_function)
1143
1144 #define init_wait(wait)                                                         \
1145         do {                                                                    \
1146                 (wait)->private = current;                                      \
1147                 (wait)->func = autoremove_wake_function;                        \
1148                 INIT_LIST_HEAD(&(wait)->entry);                                 \
1149                 (wait)->flags = 0;                                              \
1150         } while (0)
1151
1152 bool try_invoke_on_locked_down_task(struct task_struct *p, bool (*func)(struct task_struct *t, void *arg), void *arg);
1153
1154 #endif /* _LINUX_WAIT_H */