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 #define WQ_FLAG_DONE            0x10
  25 #define WQ_FLAG_PRIORITY        0x20
  26
  27 /*
  28  * A single wait-queue entry structure:
  29  */
  30 struct wait_queue_entry {
  31         unsigned int            flags;
  32         void                    *private;
  33         wait_queue_func_t       func;
  34         struct list_head        entry;
  35 };
  36
  37 struct wait_queue_head {
  38         spinlock_t              lock;
  39         struct list_head        head;
  40 };
  41 typedef struct wait_queue_head wait_queue_head_t;
  42
  43 struct task_struct;
  44
  45 /*
  46  * Macros for declaration and initialisaton of the datatypes
  47  */
  48
  49 #define __WAITQUEUE_INITIALIZER(name, tsk) {                                    \
  50         .private        = tsk,                                                  \
  51         .func           = default_wake_function,                                \
  52         .entry          = { NULL, NULL } }
  53
  54 #define DECLARE_WAITQUEUE(name, tsk)                                            \
  55         struct wait_queue_entry name = __WAITQUEUE_INITIALIZER(name, tsk)
  56
  57 #define __WAIT_QUEUE_HEAD_INITIALIZER(name) {                                   \
  58         .lock           = __SPIN_LOCK_UNLOCKED(name.lock),                      \
  59         .head           = LIST_HEAD_INIT(name.head) }
  60
  61 #define DECLARE_WAIT_QUEUE_HEAD(name) \
  62         struct wait_queue_head name = __WAIT_QUEUE_HEAD_INITIALIZER(name)
  63
  64 extern void __init_waitqueue_head(struct wait_queue_head *wq_head, const char *name, struct lock_class_key *);
  65
  66 #define init_waitqueue_head(wq_head)                                            \
  67         do {                                                                    \
  68                 static struct lock_class_key __key;                             \
  69                                                                                 \
  70                 __init_waitqueue_head((wq_head), #wq_head, &__key);             \
  71         } while (0)
  72
  73 #ifdef CONFIG_LOCKDEP
  74 # define __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) \
  75         ({ init_waitqueue_head(&name); name; })
  76 # define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) \
  77         struct wait_queue_head name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name)
  78 #else
  79 # define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) DECLARE_WAIT_QUEUE_HEAD(name)
  80 #endif
  81
  82 static inline void init_waitqueue_entry(struct wait_queue_entry *wq_entry, struct task_struct *p)
  83 {
  84         wq_entry->flags         = 0;
  85         wq_entry->private       = p;
  86         wq_entry->func          = default_wake_function;
  87 }
  88
  89 static inline void
  90 init_waitqueue_func_entry(struct wait_queue_entry *wq_entry, wait_queue_func_t func)
  91 {
  92         wq_entry->flags         = 0;
  93         wq_entry->private       = NULL;
  94         wq_entry->func          = func;
  95 }
  96
  97 /**
  98  * waitqueue_active -- locklessly test for waiters on the queue
  99  * @wq_head: the waitqueue to test for waiters
 100  *
 101  * returns true if the wait list is not empty
 102  *
 103  * NOTE: this function is lockless and requires care, incorrect usage _will_
 104  * lead to sporadic and non-obvious failure.
 105  *
 106  * Use either while holding wait_queue_head::lock or when used for wakeups
 107  * with an extra smp_mb() like::
 108  *
 109  *      CPU0 - waker                    CPU1 - waiter
 110  *
 111  *                                      for (;;) {
 112  *      @cond = true;                     prepare_to_wait(&wq_head, &wait, state);
 113  *      smp_mb();                         // smp_mb() from set_current_state()
 114  *      if (waitqueue_active(wq_head))         if (@cond)
 115  *        wake_up(wq_head);                      break;
 116  *                                        schedule();
 117  *                                      }
 118  *                                      finish_wait(&wq_head, &wait);
 119  *
 120  * Because without the explicit smp_mb() it's possible for the
 121  * waitqueue_active() load to get hoisted over the @cond store such that we'll
 122  * observe an empty wait list while the waiter might not observe @cond.
 123  *
 124  * Also note that this 'optimization' trades a spin_lock() for an smp_mb(),
 125  * which (when the lock is uncontended) are of roughly equal cost.
 126  */
 127 static inline int waitqueue_active(struct wait_queue_head *wq_head)
 128 {
 129         return !list_empty(&wq_head->head);
 130 }
 131
 132 /**
 133  * wq_has_single_sleeper - check if there is only one sleeper
 134  * @wq_head: wait queue head
 135  *
 136  * Returns true of wq_head has only one sleeper on the list.
 137  *
 138  * Please refer to the comment for waitqueue_active.
 139  */
 140 static inline bool wq_has_single_sleeper(struct wait_queue_head *wq_head)
 141 {
 142         return list_is_singular(&wq_head->head);
 143 }
 144
 145 /**
 146  * wq_has_sleeper - check if there are any waiting processes
 147  * @wq_head: wait queue head
 148  *
 149  * Returns true if wq_head has waiting processes
 150  *
 151  * Please refer to the comment for waitqueue_active.
 152  */
 153 static inline bool wq_has_sleeper(struct wait_queue_head *wq_head)
 154 {
 155         /*
 156          * We need to be sure we are in sync with the
 157          * add_wait_queue modifications to the wait queue.
 158          *
 159          * This memory barrier should be paired with one on the
 160          * waiting side.
 161          */
 162         smp_mb();
 163         return waitqueue_active(wq_head);
 164 }
 165
 166 extern void add_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);
 167 extern void add_wait_queue_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);
 168 extern void add_wait_queue_priority(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);
 169 extern void remove_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);
 170
 171 static inline void __add_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
 172 {
 173         struct list_head *head = &wq_head->head;
 174         struct wait_queue_entry *wq;
 175
 176         list_for_each_entry(wq, &wq_head->head, entry) {
 177                 if (!(wq->flags & WQ_FLAG_PRIORITY))
 178                         break;
 179                 head = &wq->entry;
 180         }
 181         list_add(&wq_entry->entry, head);
 182 }
 183
 184 /*
 185  * Used for wake-one threads:
 186  */
 187 static inline void
 188 __add_wait_queue_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
 189 {
 190         wq_entry->flags |= WQ_FLAG_EXCLUSIVE;
 191         __add_wait_queue(wq_head, wq_entry);
 192 }
 193
 194 static inline void __add_wait_queue_entry_tail(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
 195 {
 196         list_add_tail(&wq_entry->entry, &wq_head->head);
 197 }
 198
 199 static inline void
 200 __add_wait_queue_entry_tail_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
 201 {
 202         wq_entry->flags |= WQ_FLAG_EXCLUSIVE;
 203         __add_wait_queue_entry_tail(wq_head, wq_entry);
 204 }
 205
 206 static inline void
 207 __remove_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
 208 {
 209         list_del(&wq_entry->entry);
 210 }
 211
 212 void __wake_up(struct wait_queue_head *wq_head, unsigned int mode, int nr, void *key);
 213 void __wake_up_locked_key(struct wait_queue_head *wq_head, unsigned int mode, void *key);
 214 void __wake_up_locked_key_bookmark(struct wait_queue_head *wq_head,
 215                 unsigned int mode, void *key, wait_queue_entry_t *bookmark);
 216 void __wake_up_sync_key(struct wait_queue_head *wq_head, unsigned int mode, void *key);
 217 void __wake_up_locked_sync_key(struct wait_queue_head *wq_head, unsigned int mode, void *key);
 218 void __wake_up_locked(struct wait_queue_head *wq_head, unsigned int mode, int nr);
 219 void __wake_up_sync(struct wait_queue_head *wq_head, unsigned int mode);
 220 void __wake_up_pollfree(struct wait_queue_head *wq_head);
 221
 222 #define wake_up(x)                      __wake_up(x, TASK_NORMAL, 1, NULL)
 223 #define wake_up_nr(x, nr)               __wake_up(x, TASK_NORMAL, nr, NULL)
 224 #define wake_up_all(x)                  __wake_up(x, TASK_NORMAL, 0, NULL)
 225 #define wake_up_locked(x)               __wake_up_locked((x), TASK_NORMAL, 1)
 226 #define wake_up_all_locked(x)           __wake_up_locked((x), TASK_NORMAL, 0)
 227
 228 #define wake_up_interruptible(x)        __wake_up(x, TASK_INTERRUPTIBLE, 1, NULL)
 229 #define wake_up_interruptible_nr(x, nr) __wake_up(x, TASK_INTERRUPTIBLE, nr, NULL)
 230 #define wake_up_interruptible_all(x)    __wake_up(x, TASK_INTERRUPTIBLE, 0, NULL)
 231 #define wake_up_interruptible_sync(x)   __wake_up_sync((x), TASK_INTERRUPTIBLE)
 232
 233 /*
 234  * Wakeup macros to be used to report events to the targets.
 235  */
 236 #define poll_to_key(m) ((void *)(__force uintptr_t)(__poll_t)(m))
 237 #define key_to_poll(m) ((__force __poll_t)(uintptr_t)(void *)(m))
 238 #define wake_up_poll(x, m)                                                      \
 239         __wake_up(x, TASK_NORMAL, 1, poll_to_key(m))
 240 #define wake_up_locked_poll(x, m)                                               \
 241         __wake_up_locked_key((x), TASK_NORMAL, poll_to_key(m))
 242 #define wake_up_interruptible_poll(x, m)                                        \
 243         __wake_up(x, TASK_INTERRUPTIBLE, 1, poll_to_key(m))
 244 #define wake_up_interruptible_sync_poll(x, m)                                   \
 245         __wake_up_sync_key((x), TASK_INTERRUPTIBLE, poll_to_key(m))
 246 #define wake_up_interruptible_sync_poll_locked(x, m)                            \
 247         __wake_up_locked_sync_key((x), TASK_INTERRUPTIBLE, poll_to_key(m))
 248
 249 /**
 250  * wake_up_pollfree - signal that a polled waitqueue is going away
 251  * @wq_head: the wait queue head
 252  *
 253  * In the very rare cases where a ->poll() implementation uses a waitqueue whose
 254  * lifetime is tied to a task rather than to the 'struct file' being polled,
 255  * this function must be called before the waitqueue is freed so that
 256  * non-blocking polls (e.g. epoll) are notified that the queue is going away.
 257  *
 258  * The caller must also RCU-delay the freeing of the wait_queue_head, e.g. via
 259  * an explicit synchronize_rcu() or call_rcu(), or via SLAB_TYPESAFE_BY_RCU.
 260  */
 261 static inline void wake_up_pollfree(struct wait_queue_head *wq_head)
 262 {
 263         /*
 264          * For performance reasons, we don't always take the queue lock here.
 265          * Therefore, we might race with someone removing the last entry from
 266          * the queue, and proceed while they still hold the queue lock.
 267          * However, rcu_read_lock() is required to be held in such cases, so we
 268          * can safely proceed with an RCU-delayed free.
 269          */
 270         if (waitqueue_active(wq_head))
 271                 __wake_up_pollfree(wq_head);
 272 }
 273
 274 #define ___wait_cond_timeout(condition)                                         \
 275 ({                                                                              \
 276         bool __cond = (condition);                                              \
 277         if (__cond && !__ret)                                                   \
 278                 __ret = 1;                                                      \
 279         __cond || !__ret;                                                       \
 280 })
 281
 282 #define ___wait_is_interruptible(state)                                         \
 283         (!__builtin_constant_p(state) ||                                        \
 284                 state == TASK_INTERRUPTIBLE || state == TASK_KILLABLE)          \
 285
 286 extern void init_wait_entry(struct wait_queue_entry *wq_entry, int flags);
 287
 288 /*
 289  * The below macro ___wait_event() has an explicit shadow of the __ret
 290  * variable when used from the wait_event_*() macros.
 291  *
 292  * This is so that both can use the ___wait_cond_timeout() construct
 293  * to wrap the condition.
 294  *
 295  * The type inconsistency of the wait_event_*() __ret variable is also
 296  * on purpose; we use long where we can return timeout values and int
 297  * otherwise.
 298  */
 299
 300 #define ___wait_event(wq_head, condition, state, exclusive, ret, cmd)           \
 301 ({                                                                              \
 302         __label__ __out;                                                        \
 303         struct wait_queue_entry __wq_entry;                                     \
 304         long __ret = ret;       /* explicit shadow */                           \
 305                                                                                 \
 306         init_wait_entry(&__wq_entry, exclusive ? WQ_FLAG_EXCLUSIVE : 0);        \
 307         for (;;) {                                                              \
 308                 long __int = prepare_to_wait_event(&wq_head, &__wq_entry, state);\
 309                                                                                 \
 310                 if (condition)                                                  \
 311                         break;                                                  \
 312                                                                                 \
 313                 if (___wait_is_interruptible(state) && __int) {                 \
 314                         __ret = __int;                                          \
 315                         goto __out;                                             \
 316                 }                                                               \
 317                                                                                 \
 318                 cmd;                                                            \
 319         }                                                                       \
 320         finish_wait(&wq_head, &__wq_entry);                                     \
 321 __out:  __ret;                                                                  \
 322 })
 323
 324 #define __wait_event(wq_head, condition)                                        \
 325         (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0,     \
 326                             schedule())
 327
 328 /**
 329  * wait_event - sleep until a condition gets true
 330  * @wq_head: the waitqueue to wait on
 331  * @condition: a C expression for the event to wait for
 332  *
 333  * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
 334  * @condition evaluates to true. The @condition is checked each time
 335  * the waitqueue @wq_head is woken up.
 336  *
 337  * wake_up() has to be called after changing any variable that could
 338  * change the result of the wait condition.
 339  */
 340 #define wait_event(wq_head, condition)                                          \
 341 do {                                                                            \
 342         might_sleep();                                                          \
 343         if (condition)                                                          \
 344                 break;                                                          \
 345         __wait_event(wq_head, condition);                                       \
 346 } while (0)
 347
 348 #define __io_wait_event(wq_head, condition)                                     \
 349         (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0,     \
 350                             io_schedule())
 351
 352 /*
 353  * io_wait_event() -- like wait_event() but with io_schedule()
 354  */
 355 #define io_wait_event(wq_head, condition)                                       \
 356 do {                                                                            \
 357         might_sleep();                                                          \
 358         if (condition)                                                          \
 359                 break;                                                          \
 360         __io_wait_event(wq_head, condition);                                    \
 361 } while (0)
 362
 363 #define __wait_event_freezable(wq_head, condition)                              \
 364         ___wait_event(wq_head, condition, TASK_INTERRUPTIBLE, 0, 0,             \
 365                             freezable_schedule())
 366
 367 /**
 368  * wait_event_freezable - sleep (or freeze) until a condition gets true
 369  * @wq_head: the waitqueue to wait on
 370  * @condition: a C expression for the event to wait for
 371  *
 372  * The process is put to sleep (TASK_INTERRUPTIBLE -- so as not to contribute
 373  * to system load) until the @condition evaluates to true. The
 374  * @condition is checked each time the waitqueue @wq_head is woken up.
 375  *
 376  * wake_up() has to be called after changing any variable that could
 377  * change the result of the wait condition.
 378  */
 379 #define wait_event_freezable(wq_head, condition)                                \
 380 ({                                                                              \
 381         int __ret = 0;                                                          \
 382         might_sleep();                                                          \
 383         if (!(condition))                                                       \
 384                 __ret = __wait_event_freezable(wq_head, condition);             \
 385         __ret;                                                                  \
 386 })
 387
 388 #define __wait_event_timeout(wq_head, condition, timeout)                       \
 389         ___wait_event(wq_head, ___wait_cond_timeout(condition),                 \
 390                       TASK_UNINTERRUPTIBLE, 0, timeout,                         \
 391                       __ret = schedule_timeout(__ret))
 392
 393 /**
 394  * wait_event_timeout - sleep until a condition gets true or a timeout elapses
 395  * @wq_head: the waitqueue to wait on
 396  * @condition: a C expression for the event to wait for
 397  * @timeout: timeout, in jiffies
 398  *
 399  * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
 400  * @condition evaluates to true. The @condition is checked each time
 401  * the waitqueue @wq_head is woken up.
 402  *
 403  * wake_up() has to be called after changing any variable that could
 404  * change the result of the wait condition.
 405  *
 406  * Returns:
 407  * 0 if the @condition evaluated to %false after the @timeout elapsed,
 408  * 1 if the @condition evaluated to %true after the @timeout elapsed,
 409  * or the remaining jiffies (at least 1) if the @condition evaluated
 410  * to %true before the @timeout elapsed.
 411  */
 412 #define wait_event_timeout(wq_head, condition, timeout)                         \
 413 ({                                                                              \
 414         long __ret = timeout;                                                   \
 415         might_sleep();                                                          \
 416         if (!___wait_cond_timeout(condition))                                   \
 417                 __ret = __wait_event_timeout(wq_head, condition, timeout);      \
 418         __ret;                                                                  \
 419 })
 420
 421 #define __wait_event_freezable_timeout(wq_head, condition, timeout)             \
 422         ___wait_event(wq_head, ___wait_cond_timeout(condition),                 \
 423                       TASK_INTERRUPTIBLE, 0, timeout,                           \
 424                       __ret = freezable_schedule_timeout(__ret))
 425
 426 /*
 427  * like wait_event_timeout() -- except it uses TASK_INTERRUPTIBLE to avoid
 428  * increasing load and is freezable.
 429  */
 430 #define wait_event_freezable_timeout(wq_head, condition, timeout)               \
 431 ({                                                                              \
 432         long __ret = timeout;                                                   \
 433         might_sleep();                                                          \
 434         if (!___wait_cond_timeout(condition))                                   \
 435                 __ret = __wait_event_freezable_timeout(wq_head, condition, timeout); \
 436         __ret;                                                                  \
 437 })
 438
 439 #define __wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2)              \
 440         (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 1, 0,     \
 441                             cmd1; schedule(); cmd2)
 442 /*
 443  * Just like wait_event_cmd(), except it sets exclusive flag
 444  */
 445 #define wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2)                \
 446 do {                                                                            \
 447         if (condition)                                                          \
 448                 break;                                                          \
 449         __wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2);             \
 450 } while (0)
 451
 452 #define __wait_event_cmd(wq_head, condition, cmd1, cmd2)                        \
 453         (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0,     \
 454                             cmd1; schedule(); cmd2)
 455
 456 /**
 457  * wait_event_cmd - sleep until a condition gets true
 458  * @wq_head: the waitqueue to wait on
 459  * @condition: a C expression for the event to wait for
 460  * @cmd1: the command will be executed before sleep
 461  * @cmd2: the command will be executed after sleep
 462  *
 463  * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
 464  * @condition evaluates to true. The @condition is checked each time
 465  * the waitqueue @wq_head is woken up.
 466  *
 467  * wake_up() has to be called after changing any variable that could
 468  * change the result of the wait condition.
 469  */
 470 #define wait_event_cmd(wq_head, condition, cmd1, cmd2)                          \
 471 do {                                                                            \
 472         if (condition)                                                          \
 473                 break;                                                          \
 474         __wait_event_cmd(wq_head, condition, cmd1, cmd2);                       \
 475 } while (0)
 476
 477 #define __wait_event_interruptible(wq_head, condition)                          \
 478         ___wait_event(wq_head, condition, TASK_INTERRUPTIBLE, 0, 0,             \
 479                       schedule())
 480
 481 /**
 482  * wait_event_interruptible - sleep until a condition gets true
 483  * @wq_head: the waitqueue to wait on
 484  * @condition: a C expression for the event to wait for
 485  *
 486  * The process is put to sleep (TASK_INTERRUPTIBLE) until the
 487  * @condition evaluates to true or a signal is received.
 488  * The @condition is checked each time the waitqueue @wq_head is woken up.
 489  *
 490  * wake_up() has to be called after changing any variable that could
 491  * change the result of the wait condition.
 492  *
 493  * The function will return -ERESTARTSYS if it was interrupted by a
 494  * signal and 0 if @condition evaluated to true.
 495  */
 496 #define wait_event_interruptible(wq_head, condition)                            \
 497 ({                                                                              \
 498         int __ret = 0;                                                          \
 499         might_sleep();                                                          \
 500         if (!(condition))                                                       \
 501                 __ret = __wait_event_interruptible(wq_head, condition);         \
 502         __ret;                                                                  \
 503 })
 504
 505 #define __wait_event_interruptible_timeout(wq_head, condition, timeout)         \
 506         ___wait_event(wq_head, ___wait_cond_timeout(condition),                 \
 507                       TASK_INTERRUPTIBLE, 0, timeout,                           \
 508                       __ret = schedule_timeout(__ret))
 509
 510 /**
 511  * wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses
 512  * @wq_head: the waitqueue to wait on
 513  * @condition: a C expression for the event to wait for
 514  * @timeout: timeout, in jiffies
 515  *
 516  * The process is put to sleep (TASK_INTERRUPTIBLE) until the
 517  * @condition evaluates to true or a signal is received.
 518  * The @condition is checked each time the waitqueue @wq_head is woken up.
 519  *
 520  * wake_up() has to be called after changing any variable that could
 521  * change the result of the wait condition.
 522  *
 523  * Returns:
 524  * 0 if the @condition evaluated to %false after the @timeout elapsed,
 525  * 1 if the @condition evaluated to %true after the @timeout elapsed,
 526  * the remaining jiffies (at least 1) if the @condition evaluated
 527  * to %true before the @timeout elapsed, or -%ERESTARTSYS if it was
 528  * interrupted by a signal.
 529  */
 530 #define wait_event_interruptible_timeout(wq_head, condition, timeout)           \
 531 ({                                                                              \
 532         long __ret = timeout;                                                   \
 533         might_sleep();                                                          \
 534         if (!___wait_cond_timeout(condition))                                   \
 535                 __ret = __wait_event_interruptible_timeout(wq_head,             \
 536                                                 condition, timeout);            \
 537         __ret;                                                                  \
 538 })
 539
 540 #define __wait_event_hrtimeout(wq_head, condition, timeout, state)              \
 541 ({                                                                              \
 542         int __ret = 0;                                                          \
 543         struct hrtimer_sleeper __t;                                             \
 544                                                                                 \
 545         hrtimer_init_sleeper_on_stack(&__t, CLOCK_MONOTONIC,                    \
 546                                       HRTIMER_MODE_REL);                        \
 547         if ((timeout) != KTIME_MAX)                                             \
 548                 hrtimer_start_range_ns(&__t.timer, timeout,                     \
 549                                        current->timer_slack_ns,                 \
 550                                        HRTIMER_MODE_REL);                       \
 551                                                                                 \
 552         __ret = ___wait_event(wq_head, condition, state, 0, 0,                  \
 553                 if (!__t.task) {                                                \
 554                         __ret = -ETIME;                                         \
 555                         break;                                                  \
 556                 }                                                               \
 557                 schedule());                                                    \
 558                                                                                 \
 559         hrtimer_cancel(&__t.timer);                                             \
 560         destroy_hrtimer_on_stack(&__t.timer);                                   \
 561         __ret;                                                                  \
 562 })
 563
 564 /**
 565  * wait_event_hrtimeout - sleep until a condition gets true or a timeout elapses
 566  * @wq_head: the waitqueue to wait on
 567  * @condition: a C expression for the event to wait for
 568  * @timeout: timeout, as a ktime_t
 569  *
 570  * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
 571  * @condition evaluates to true or a signal is received.
 572  * The @condition is checked each time the waitqueue @wq_head is woken up.
 573  *
 574  * wake_up() has to be called after changing any variable that could
 575  * change the result of the wait condition.
 576  *
 577  * The function returns 0 if @condition became true, or -ETIME if the timeout
 578  * elapsed.
 579  */
 580 #define wait_event_hrtimeout(wq_head, condition, timeout)                       \
 581 ({                                                                              \
 582         int __ret = 0;                                                          \
 583         might_sleep();                                                          \
 584         if (!(condition))                                                       \
 585                 __ret = __wait_event_hrtimeout(wq_head, condition, timeout,     \
 586                                                TASK_UNINTERRUPTIBLE);           \
 587         __ret;                                                                  \
 588 })
 589
 590 /**
 591  * wait_event_interruptible_hrtimeout - sleep until a condition gets true or a timeout elapses
 592  * @wq: the waitqueue to wait on
 593  * @condition: a C expression for the event to wait for
 594  * @timeout: timeout, as a ktime_t
 595  *
 596  * The process is put to sleep (TASK_INTERRUPTIBLE) until the
 597  * @condition evaluates to true or a signal is received.
 598  * The @condition is checked each time the waitqueue @wq is woken up.
 599  *
 600  * wake_up() has to be called after changing any variable that could
 601  * change the result of the wait condition.
 602  *
 603  * The function returns 0 if @condition became true, -ERESTARTSYS if it was
 604  * interrupted by a signal, or -ETIME if the timeout elapsed.
 605  */
 606 #define wait_event_interruptible_hrtimeout(wq, condition, timeout)              \
 607 ({                                                                              \
 608         long __ret = 0;                                                         \
 609         might_sleep();                                                          \
 610         if (!(condition))                                                       \
 611                 __ret = __wait_event_hrtimeout(wq, condition, timeout,          \
 612                                                TASK_INTERRUPTIBLE);             \
 613         __ret;                                                                  \
 614 })
 615
 616 #define __wait_event_interruptible_exclusive(wq, condition)                     \
 617         ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, 0,                  \
 618                       schedule())
 619
 620 #define wait_event_interruptible_exclusive(wq, condition)                       \
 621 ({                                                                              \
 622         int __ret = 0;                                                          \
 623         might_sleep();                                                          \
 624         if (!(condition))                                                       \
 625                 __ret = __wait_event_interruptible_exclusive(wq, condition);    \
 626         __ret;                                                                  \
 627 })
 628
 629 #define __wait_event_killable_exclusive(wq, condition)                          \
 630         ___wait_event(wq, condition, TASK_KILLABLE, 1, 0,                       \
 631                       schedule())
 632
 633 #define wait_event_killable_exclusive(wq, condition)                            \
 634 ({                                                                              \
 635         int __ret = 0;                                                          \
 636         might_sleep();                                                          \
 637         if (!(condition))                                                       \
 638                 __ret = __wait_event_killable_exclusive(wq, condition);         \
 639         __ret;                                                                  \
 640 })
 641
 642
 643 #define __wait_event_freezable_exclusive(wq, condition)                         \
 644         ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, 0,                  \
 645                         freezable_schedule())
 646
 647 #define wait_event_freezable_exclusive(wq, condition)                           \
 648 ({                                                                              \
 649         int __ret = 0;                                                          \
 650         might_sleep();                                                          \
 651         if (!(condition))                                                       \
 652                 __ret = __wait_event_freezable_exclusive(wq, condition);        \
 653         __ret;                                                                  \
 654 })
 655
 656 /**
 657  * wait_event_idle - wait for a condition without contributing to system load
 658  * @wq_head: the waitqueue to wait on
 659  * @condition: a C expression for the event to wait for
 660  *
 661  * The process is put to sleep (TASK_IDLE) until the
 662  * @condition evaluates to true.
 663  * The @condition is checked each time the waitqueue @wq_head is woken up.
 664  *
 665  * wake_up() has to be called after changing any variable that could
 666  * change the result of the wait condition.
 667  *
 668  */
 669 #define wait_event_idle(wq_head, condition)                                     \
 670 do {                                                                            \
 671         might_sleep();                                                          \
 672         if (!(condition))                                                       \
 673                 ___wait_event(wq_head, condition, TASK_IDLE, 0, 0, schedule()); \
 674 } while (0)
 675
 676 /**
 677  * wait_event_idle_exclusive - wait for a condition with contributing to system load
 678  * @wq_head: the waitqueue to wait on
 679  * @condition: a C expression for the event to wait for
 680  *
 681  * The process is put to sleep (TASK_IDLE) until the
 682  * @condition evaluates to true.
 683  * The @condition is checked each time the waitqueue @wq_head is woken up.
 684  *
 685  * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
 686  * set thus if other processes wait on the same list, when this
 687  * process is woken further processes are not considered.
 688  *
 689  * wake_up() has to be called after changing any variable that could
 690  * change the result of the wait condition.
 691  *
 692  */
 693 #define wait_event_idle_exclusive(wq_head, condition)                           \
 694 do {                                                                            \
 695         might_sleep();                                                          \
 696         if (!(condition))                                                       \
 697                 ___wait_event(wq_head, condition, TASK_IDLE, 1, 0, schedule()); \
 698 } while (0)
 699
 700 #define __wait_event_idle_timeout(wq_head, condition, timeout)                  \
 701         ___wait_event(wq_head, ___wait_cond_timeout(condition),                 \
 702                       TASK_IDLE, 0, timeout,                                    \
 703                       __ret = schedule_timeout(__ret))
 704
 705 /**
 706  * wait_event_idle_timeout - sleep without load until a condition becomes true or a timeout elapses
 707  * @wq_head: the waitqueue to wait on
 708  * @condition: a C expression for the event to wait for
 709  * @timeout: timeout, in jiffies
 710  *
 711  * The process is put to sleep (TASK_IDLE) until the
 712  * @condition evaluates to true. The @condition is checked each time
 713  * the waitqueue @wq_head is woken up.
 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_timeout(wq_head, condition, timeout)                    \
 725 ({                                                                              \
 726         long __ret = timeout;                                                   \
 727         might_sleep();                                                          \
 728         if (!___wait_cond_timeout(condition))                                   \
 729                 __ret = __wait_event_idle_timeout(wq_head, condition, timeout); \
 730         __ret;                                                                  \
 731 })
 732
 733 #define __wait_event_idle_exclusive_timeout(wq_head, condition, timeout)        \
 734         ___wait_event(wq_head, ___wait_cond_timeout(condition),                 \
 735                       TASK_IDLE, 1, timeout,                                    \
 736                       __ret = schedule_timeout(__ret))
 737
 738 /**
 739  * wait_event_idle_exclusive_timeout - sleep without load until a condition becomes true or a timeout elapses
 740  * @wq_head: the waitqueue to wait on
 741  * @condition: a C expression for the event to wait for
 742  * @timeout: timeout, in jiffies
 743  *
 744  * The process is put to sleep (TASK_IDLE) until the
 745  * @condition evaluates to true. The @condition is checked each time
 746  * the waitqueue @wq_head is woken up.
 747  *
 748  * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
 749  * set thus if other processes wait on the same list, when this
 750  * process is woken further processes are not considered.
 751  *
 752  * wake_up() has to be called after changing any variable that could
 753  * change the result of the wait condition.
 754  *
 755  * Returns:
 756  * 0 if the @condition evaluated to %false after the @timeout elapsed,
 757  * 1 if the @condition evaluated to %true after the @timeout elapsed,
 758  * or the remaining jiffies (at least 1) if the @condition evaluated
 759  * to %true before the @timeout elapsed.
 760  */
 761 #define wait_event_idle_exclusive_timeout(wq_head, condition, timeout)          \
 762 ({                                                                              \
 763         long __ret = timeout;                                                   \
 764         might_sleep();                                                          \
 765         if (!___wait_cond_timeout(condition))                                   \
 766                 __ret = __wait_event_idle_exclusive_timeout(wq_head, condition, timeout);\
 767         __ret;                                                                  \
 768 })
 769
 770 extern int do_wait_intr(wait_queue_head_t *, wait_queue_entry_t *);
 771 extern int do_wait_intr_irq(wait_queue_head_t *, wait_queue_entry_t *);
 772
 773 #define __wait_event_interruptible_locked(wq, condition, exclusive, fn)         \
 774 ({                                                                              \
 775         int __ret;                                                              \
 776         DEFINE_WAIT(__wait);                                                    \
 777         if (exclusive)                                                          \
 778                 __wait.flags |= WQ_FLAG_EXCLUSIVE;                              \
 779         do {                                                                    \
 780                 __ret = fn(&(wq), &__wait);                                     \
 781                 if (__ret)                                                      \
 782                         break;                                                  \
 783         } while (!(condition));                                                 \
 784         __remove_wait_queue(&(wq), &__wait);                                    \
 785         __set_current_state(TASK_RUNNING);                                      \
 786         __ret;                                                                  \
 787 })
 788
 789
 790 /**
 791  * wait_event_interruptible_locked - sleep until a condition gets true
 792  * @wq: the waitqueue to wait on
 793  * @condition: a C expression for the event to wait for
 794  *
 795  * The process is put to sleep (TASK_INTERRUPTIBLE) until the
 796  * @condition evaluates to true or a signal is received.
 797  * The @condition is checked each time the waitqueue @wq is woken up.
 798  *
 799  * It must be called with wq.lock being held.  This spinlock is
 800  * unlocked while sleeping but @condition testing is done while lock
 801  * is held and when this macro exits the lock is held.
 802  *
 803  * The lock is locked/unlocked using spin_lock()/spin_unlock()
 804  * functions which must match the way they are locked/unlocked outside
 805  * of this macro.
 806  *
 807  * wake_up_locked() has to be called after changing any variable that could
 808  * change the result of the wait condition.
 809  *
 810  * The function will return -ERESTARTSYS if it was interrupted by a
 811  * signal and 0 if @condition evaluated to true.
 812  */
 813 #define wait_event_interruptible_locked(wq, condition)                          \
 814         ((condition)                                                            \
 815          ? 0 : __wait_event_interruptible_locked(wq, condition, 0, do_wait_intr))
 816
 817 /**
 818  * wait_event_interruptible_locked_irq - sleep until a condition gets true
 819  * @wq: the waitqueue to wait on
 820  * @condition: a C expression for the event to wait for
 821  *
 822  * The process is put to sleep (TASK_INTERRUPTIBLE) until the
 823  * @condition evaluates to true or a signal is received.
 824  * The @condition is checked each time the waitqueue @wq is woken up.
 825  *
 826  * It must be called with wq.lock being held.  This spinlock is
 827  * unlocked while sleeping but @condition testing is done while lock
 828  * is held and when this macro exits the lock is held.
 829  *
 830  * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq()
 831  * functions which must match the way they are locked/unlocked outside
 832  * of this macro.
 833  *
 834  * wake_up_locked() has to be called after changing any variable that could
 835  * change the result of the wait condition.
 836  *
 837  * The function will return -ERESTARTSYS if it was interrupted by a
 838  * signal and 0 if @condition evaluated to true.
 839  */
 840 #define wait_event_interruptible_locked_irq(wq, condition)                      \
 841         ((condition)                                                            \
 842          ? 0 : __wait_event_interruptible_locked(wq, condition, 0, do_wait_intr_irq))
 843
 844 /**
 845  * wait_event_interruptible_exclusive_locked - sleep exclusively until a condition gets true
 846  * @wq: the waitqueue to wait on
 847  * @condition: a C expression for the event to wait for
 848  *
 849  * The process is put to sleep (TASK_INTERRUPTIBLE) until the
 850  * @condition evaluates to true or a signal is received.
 851  * The @condition is checked each time the waitqueue @wq is woken up.
 852  *
 853  * It must be called with wq.lock being held.  This spinlock is
 854  * unlocked while sleeping but @condition testing is done while lock
 855  * is held and when this macro exits the lock is held.
 856  *
 857  * The lock is locked/unlocked using spin_lock()/spin_unlock()
 858  * functions which must match the way they are locked/unlocked outside
 859  * of this macro.
 860  *
 861  * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
 862  * set thus when other process waits process on the list if this
 863  * process is awaken further processes are not considered.
 864  *
 865  * wake_up_locked() has to be called after changing any variable that could
 866  * change the result of the wait condition.
 867  *
 868  * The function will return -ERESTARTSYS if it was interrupted by a
 869  * signal and 0 if @condition evaluated to true.
 870  */
 871 #define wait_event_interruptible_exclusive_locked(wq, condition)                \
 872         ((condition)                                                            \
 873          ? 0 : __wait_event_interruptible_locked(wq, condition, 1, do_wait_intr))
 874
 875 /**
 876  * wait_event_interruptible_exclusive_locked_irq - sleep until a condition gets true
 877  * @wq: the waitqueue to wait on
 878  * @condition: a C expression for the event to wait for
 879  *
 880  * The process is put to sleep (TASK_INTERRUPTIBLE) until the
 881  * @condition evaluates to true or a signal is received.
 882  * The @condition is checked each time the waitqueue @wq is woken up.
 883  *
 884  * It must be called with wq.lock being held.  This spinlock is
 885  * unlocked while sleeping but @condition testing is done while lock
 886  * is held and when this macro exits the lock is held.
 887  *
 888  * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq()
 889  * functions which must match the way they are locked/unlocked outside
 890  * of this macro.
 891  *
 892  * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
 893  * set thus when other process waits process on the list if this
 894  * process is awaken further processes are not considered.
 895  *
 896  * wake_up_locked() has to be called after changing any variable that could
 897  * change the result of the wait condition.
 898  *
 899  * The function will return -ERESTARTSYS if it was interrupted by a
 900  * signal and 0 if @condition evaluated to true.
 901  */
 902 #define wait_event_interruptible_exclusive_locked_irq(wq, condition)            \
 903         ((condition)                                                            \
 904          ? 0 : __wait_event_interruptible_locked(wq, condition, 1, do_wait_intr_irq))
 905
 906
 907 #define __wait_event_killable(wq, condition)                                    \
 908         ___wait_event(wq, condition, TASK_KILLABLE, 0, 0, schedule())
 909
 910 /**
 911  * wait_event_killable - sleep until a condition gets true
 912  * @wq_head: the waitqueue to wait on
 913  * @condition: a C expression for the event to wait for
 914  *
 915  * The process is put to sleep (TASK_KILLABLE) until the
 916  * @condition evaluates to true or a signal is received.
 917  * The @condition is checked each time the waitqueue @wq_head is woken up.
 918  *
 919  * wake_up() has to be called after changing any variable that could
 920  * change the result of the wait condition.
 921  *
 922  * The function will return -ERESTARTSYS if it was interrupted by a
 923  * signal and 0 if @condition evaluated to true.
 924  */
 925 #define wait_event_killable(wq_head, condition)                                 \
 926 ({                                                                              \
 927         int __ret = 0;                                                          \
 928         might_sleep();                                                          \
 929         if (!(condition))                                                       \
 930                 __ret = __wait_event_killable(wq_head, condition);              \
 931         __ret;                                                                  \
 932 })
 933
 934 #define __wait_event_killable_timeout(wq_head, condition, timeout)              \
 935         ___wait_event(wq_head, ___wait_cond_timeout(condition),                 \
 936                       TASK_KILLABLE, 0, timeout,                                \
 937                       __ret = schedule_timeout(__ret))
 938
 939 /**
 940  * wait_event_killable_timeout - sleep until a condition gets true or a timeout elapses
 941  * @wq_head: the waitqueue to wait on
 942  * @condition: a C expression for the event to wait for
 943  * @timeout: timeout, in jiffies
 944  *
 945  * The process is put to sleep (TASK_KILLABLE) until the
 946  * @condition evaluates to true or a kill signal is received.
 947  * The @condition is checked each time the waitqueue @wq_head is woken up.
 948  *
 949  * wake_up() has to be called after changing any variable that could
 950  * change the result of the wait condition.
 951  *
 952  * Returns:
 953  * 0 if the @condition evaluated to %false after the @timeout elapsed,
 954  * 1 if the @condition evaluated to %true after the @timeout elapsed,
 955  * the remaining jiffies (at least 1) if the @condition evaluated
 956  * to %true before the @timeout elapsed, or -%ERESTARTSYS if it was
 957  * interrupted by a kill signal.
 958  *
 959  * Only kill signals interrupt this process.
 960  */
 961 #define wait_event_killable_timeout(wq_head, condition, timeout)                \
 962 ({                                                                              \
 963         long __ret = timeout;                                                   \
 964         might_sleep();                                                          \
 965         if (!___wait_cond_timeout(condition))                                   \
 966                 __ret = __wait_event_killable_timeout(wq_head,                  \
 967                                                 condition, timeout);            \
 968         __ret;                                                                  \
 969 })
 970
 971
 972 #define __wait_event_lock_irq(wq_head, condition, lock, cmd)                    \
 973         (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0,     \
 974                             spin_unlock_irq(&lock);                             \
 975                             cmd;                                                \
 976                             schedule();                                         \
 977                             spin_lock_irq(&lock))
 978
 979 /**
 980  * wait_event_lock_irq_cmd - sleep until a condition gets true. The
 981  *                           condition is checked under the lock. This
 982  *                           is expected to be called with the lock
 983  *                           taken.
 984  * @wq_head: the waitqueue to wait on
 985  * @condition: a C expression for the event to wait for
 986  * @lock: a locked spinlock_t, which will be released before cmd
 987  *        and schedule() and reacquired afterwards.
 988  * @cmd: a command which is invoked outside the critical section before
 989  *       sleep
 990  *
 991  * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
 992  * @condition evaluates to true. The @condition is checked each time
 993  * the waitqueue @wq_head is woken up.
 994  *
 995  * wake_up() has to be called after changing any variable that could
 996  * change the result of the wait condition.
 997  *
 998  * This is supposed to be called while holding the lock. The lock is
 999  * dropped before invoking the cmd and going to sleep and is reacquired
1000  * afterwards.
1001  */
1002 #define wait_event_lock_irq_cmd(wq_head, condition, lock, cmd)                  \
1003 do {                                                                            \
1004         if (condition)                                                          \
1005                 break;                                                          \
1006         __wait_event_lock_irq(wq_head, condition, lock, cmd);                   \
1007 } while (0)
1008
1009 /**
1010  * wait_event_lock_irq - sleep until a condition gets true. The
1011  *                       condition is checked under the lock. This
1012  *                       is expected to be called with the lock
1013  *                       taken.
1014  * @wq_head: the waitqueue to wait on
1015  * @condition: a C expression for the event to wait for
1016  * @lock: a locked spinlock_t, which will be released before schedule()
1017  *        and reacquired afterwards.
1018  *
1019  * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
1020  * @condition evaluates to true. The @condition is checked each time
1021  * the waitqueue @wq_head is woken up.
1022  *
1023  * wake_up() has to be called after changing any variable that could
1024  * change the result of the wait condition.
1025  *
1026  * This is supposed to be called while holding the lock. The lock is
1027  * dropped before going to sleep and is reacquired afterwards.
1028  */
1029 #define wait_event_lock_irq(wq_head, condition, lock)                           \
1030 do {                                                                            \
1031         if (condition)                                                          \
1032                 break;                                                          \
1033         __wait_event_lock_irq(wq_head, condition, lock, );                      \
1034 } while (0)
1035
1036
1037 #define __wait_event_interruptible_lock_irq(wq_head, condition, lock, cmd)      \
1038         ___wait_event(wq_head, condition, TASK_INTERRUPTIBLE, 0, 0,             \
1039                       spin_unlock_irq(&lock);                                   \
1040                       cmd;                                                      \
1041                       schedule();                                               \
1042                       spin_lock_irq(&lock))
1043
1044 /**
1045  * wait_event_interruptible_lock_irq_cmd - sleep until a condition gets true.
1046  *              The condition is checked under the lock. This is expected to
1047  *              be called with the lock taken.
1048  * @wq_head: the waitqueue to wait on
1049  * @condition: a C expression for the event to wait for
1050  * @lock: a locked spinlock_t, which will be released before cmd and
1051  *        schedule() and reacquired afterwards.
1052  * @cmd: a command which is invoked outside the critical section before
1053  *       sleep
1054  *
1055  * The process is put to sleep (TASK_INTERRUPTIBLE) until the
1056  * @condition evaluates to true or a signal is received. The @condition is
1057  * checked each time the waitqueue @wq_head is woken up.
1058  *
1059  * wake_up() has to be called after changing any variable that could
1060  * change the result of the wait condition.
1061  *
1062  * This is supposed to be called while holding the lock. The lock is
1063  * dropped before invoking the cmd and going to sleep and is reacquired
1064  * afterwards.
1065  *
1066  * The macro will return -ERESTARTSYS if it was interrupted by a signal
1067  * and 0 if @condition evaluated to true.
1068  */
1069 #define wait_event_interruptible_lock_irq_cmd(wq_head, condition, lock, cmd)    \
1070 ({                                                                              \
1071         int __ret = 0;                                                          \
1072         if (!(condition))                                                       \
1073                 __ret = __wait_event_interruptible_lock_irq(wq_head,            \
1074                                                 condition, lock, cmd);          \
1075         __ret;                                                                  \
1076 })
1077
1078 /**
1079  * wait_event_interruptible_lock_irq - sleep until a condition gets true.
1080  *              The condition is checked under the lock. This is expected
1081  *              to be called with the lock taken.
1082  * @wq_head: the waitqueue to wait on
1083  * @condition: a C expression for the event to wait for
1084  * @lock: a locked spinlock_t, which will be released before schedule()
1085  *        and reacquired afterwards.
1086  *
1087  * The process is put to sleep (TASK_INTERRUPTIBLE) until the
1088  * @condition evaluates to true or signal is received. The @condition is
1089  * checked each time the waitqueue @wq_head is woken up.
1090  *
1091  * wake_up() has to be called after changing any variable that could
1092  * change the result of the wait condition.
1093  *
1094  * This is supposed to be called while holding the lock. The lock is
1095  * dropped before going to sleep and is reacquired afterwards.
1096  *
1097  * The macro will return -ERESTARTSYS if it was interrupted by a signal
1098  * and 0 if @condition evaluated to true.
1099  */
1100 #define wait_event_interruptible_lock_irq(wq_head, condition, lock)             \
1101 ({                                                                              \
1102         int __ret = 0;                                                          \
1103         if (!(condition))                                                       \
1104                 __ret = __wait_event_interruptible_lock_irq(wq_head,            \
1105                                                 condition, lock,);              \
1106         __ret;                                                                  \
1107 })
1108
1109 #define __wait_event_lock_irq_timeout(wq_head, condition, lock, timeout, state) \
1110         ___wait_event(wq_head, ___wait_cond_timeout(condition),                 \
1111                       state, 0, timeout,                                        \
1112                       spin_unlock_irq(&lock);                                   \
1113                       __ret = schedule_timeout(__ret);                          \
1114                       spin_lock_irq(&lock));
1115
1116 /**
1117  * wait_event_interruptible_lock_irq_timeout - sleep until a condition gets
1118  *              true or a timeout elapses. The condition is checked under
1119  *              the lock. This is expected to be called with the lock taken.
1120  * @wq_head: the waitqueue to wait on
1121  * @condition: a C expression for the event to wait for
1122  * @lock: a locked spinlock_t, which will be released before schedule()
1123  *        and reacquired afterwards.
1124  * @timeout: timeout, in jiffies
1125  *
1126  * The process is put to sleep (TASK_INTERRUPTIBLE) until the
1127  * @condition evaluates to true or signal is received. The @condition is
1128  * checked each time the waitqueue @wq_head is woken up.
1129  *
1130  * wake_up() has to be called after changing any variable that could
1131  * change the result of the wait condition.
1132  *
1133  * This is supposed to be called while holding the lock. The lock is
1134  * dropped before going to sleep and is reacquired afterwards.
1135  *
1136  * The function returns 0 if the @timeout elapsed, -ERESTARTSYS if it
1137  * was interrupted by a signal, and the remaining jiffies otherwise
1138  * if the condition evaluated to true before the timeout elapsed.
1139  */
1140 #define wait_event_interruptible_lock_irq_timeout(wq_head, condition, lock,     \
1141                                                   timeout)                      \
1142 ({                                                                              \
1143         long __ret = timeout;                                                   \
1144         if (!___wait_cond_timeout(condition))                                   \
1145                 __ret = __wait_event_lock_irq_timeout(                          \
1146                                         wq_head, condition, lock, timeout,      \
1147                                         TASK_INTERRUPTIBLE);                    \
1148         __ret;                                                                  \
1149 })
1150
1151 #define wait_event_lock_irq_timeout(wq_head, condition, lock, timeout)          \
1152 ({                                                                              \
1153         long __ret = timeout;                                                   \
1154         if (!___wait_cond_timeout(condition))                                   \
1155                 __ret = __wait_event_lock_irq_timeout(                          \
1156                                         wq_head, condition, lock, timeout,      \
1157                                         TASK_UNINTERRUPTIBLE);                  \
1158         __ret;                                                                  \
1159 })
1160
1161 /*
1162  * Waitqueues which are removed from the waitqueue_head at wakeup time
1163  */
1164 void prepare_to_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);
1165 bool prepare_to_wait_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);
1166 long prepare_to_wait_event(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);
1167 void finish_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);
1168 long wait_woken(struct wait_queue_entry *wq_entry, unsigned mode, long timeout);
1169 int woken_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key);
1170 int autoremove_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key);
1171
1172 #define DEFINE_WAIT_FUNC(name, function)                                        \
1173         struct wait_queue_entry name = {                                        \
1174                 .private        = current,                                      \
1175                 .func           = function,                                     \
1176                 .entry          = LIST_HEAD_INIT((name).entry),                 \
1177         }
1178
1179 #define DEFINE_WAIT(name) DEFINE_WAIT_FUNC(name, autoremove_wake_function)
1180
1181 #define init_wait(wait)                                                         \
1182         do {                                                                    \
1183                 (wait)->private = current;                                      \
1184                 (wait)->func = autoremove_wake_function;                        \
1185                 INIT_LIST_HEAD(&(wait)->entry);                                 \
1186                 (wait)->flags = 0;                                              \
1187         } while (0)
1188
1189 typedef int (*task_call_f)(struct task_struct *p, void *arg);
1190 extern int task_call_func(struct task_struct *p, task_call_f func, void *arg);
1191
1192 #endif /* _LINUX_WAIT_H */