LCOV - code coverage report
Current view: top level - include/linux - wait.h (source / functions) Hit Total Coverage
Test: gcov_data_raspi2_real_modules_combined.info Lines: 9 13 69.2 %
Date: 2020-09-30 20:25:40 Functions: 0 0 -
Branches: 0 0 -

           Branch data     Line data    Source code
       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                 :            : 
      24                 :            : /*
      25                 :            :  * A single wait-queue entry structure:
      26                 :            :  */
      27                 :            : struct wait_queue_entry {
      28                 :            :         unsigned int            flags;
      29                 :            :         void                    *private;
      30                 :            :         wait_queue_func_t       func;
      31                 :            :         struct list_head        entry;
      32                 :            : };
      33                 :            : 
      34                 :            : struct wait_queue_head {
      35                 :            :         spinlock_t              lock;
      36                 :            :         struct list_head        head;
      37                 :            : };
      38                 :            : typedef struct wait_queue_head wait_queue_head_t;
      39                 :            : 
      40                 :            : struct task_struct;
      41                 :            : 
      42                 :            : /*
      43                 :            :  * Macros for declaration and initialisaton of the datatypes
      44                 :            :  */
      45                 :            : 
      46                 :            : #define __WAITQUEUE_INITIALIZER(name, tsk) {                                    \
      47                 :            :         .private        = tsk,                                                  \
      48                 :            :         .func           = default_wake_function,                                \
      49                 :            :         .entry          = { NULL, NULL } }
      50                 :            : 
      51                 :            : #define DECLARE_WAITQUEUE(name, tsk)                                            \
      52                 :            :         struct wait_queue_entry name = __WAITQUEUE_INITIALIZER(name, tsk)
      53                 :            : 
      54                 :            : #define __WAIT_QUEUE_HEAD_INITIALIZER(name) {                                   \
      55                 :            :         .lock           = __SPIN_LOCK_UNLOCKED(name.lock),                      \
      56                 :            :         .head           = { &(name).head, &(name).head } }
      57                 :            : 
      58                 :            : #define DECLARE_WAIT_QUEUE_HEAD(name) \
      59                 :            :         struct wait_queue_head name = __WAIT_QUEUE_HEAD_INITIALIZER(name)
      60                 :            : 
      61                 :            : extern void __init_waitqueue_head(struct wait_queue_head *wq_head, const char *name, struct lock_class_key *);
      62                 :            : 
      63                 :            : #define init_waitqueue_head(wq_head)                                            \
      64                 :            :         do {                                                                    \
      65                 :            :                 static struct lock_class_key __key;                             \
      66                 :            :                                                                                 \
      67                 :            :                 __init_waitqueue_head((wq_head), #wq_head, &__key);         \
      68                 :            :         } while (0)
      69                 :            : 
      70                 :            : #ifdef CONFIG_LOCKDEP
      71                 :            : # define __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) \
      72                 :            :         ({ init_waitqueue_head(&name); name; })
      73                 :            : # define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) \
      74                 :            :         struct wait_queue_head name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name)
      75                 :            : #else
      76                 :            : # define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) DECLARE_WAIT_QUEUE_HEAD(name)
      77                 :            : #endif
      78                 :            : 
      79                 :            : static inline void init_waitqueue_entry(struct wait_queue_entry *wq_entry, struct task_struct *p)
      80                 :            : {
      81                 :          0 :         wq_entry->flags              = 0;
      82                 :          0 :         wq_entry->private    = p;
      83                 :          0 :         wq_entry->func               = default_wake_function;
      84                 :            : }
      85                 :            : 
      86                 :            : static inline void
      87                 :            : init_waitqueue_func_entry(struct wait_queue_entry *wq_entry, wait_queue_func_t func)
      88                 :            : {
      89                 :    1958444 :         wq_entry->flags              = 0;
      90                 :    1958444 :         wq_entry->private    = NULL;
      91                 :    1958444 :         wq_entry->func               = func;
      92                 :            : }
      93                 :            : 
      94                 :            : /**
      95                 :            :  * waitqueue_active -- locklessly test for waiters on the queue
      96                 :            :  * @wq_head: the waitqueue to test for waiters
      97                 :            :  *
      98                 :            :  * returns true if the wait list is not empty
      99                 :            :  *
     100                 :            :  * NOTE: this function is lockless and requires care, incorrect usage _will_
     101                 :            :  * lead to sporadic and non-obvious failure.
     102                 :            :  *
     103                 :            :  * Use either while holding wait_queue_head::lock or when used for wakeups
     104                 :            :  * with an extra smp_mb() like::
     105                 :            :  *
     106                 :            :  *      CPU0 - waker                    CPU1 - waiter
     107                 :            :  *
     108                 :            :  *                                      for (;;) {
     109                 :            :  *      @cond = true;                     prepare_to_wait(&wq_head, &wait, state);
     110                 :            :  *      smp_mb();                         // smp_mb() from set_current_state()
     111                 :            :  *      if (waitqueue_active(wq_head))         if (@cond)
     112                 :            :  *        wake_up(wq_head);                      break;
     113                 :            :  *                                        schedule();
     114                 :            :  *                                      }
     115                 :            :  *                                      finish_wait(&wq_head, &wait);
     116                 :            :  *
     117                 :            :  * Because without the explicit smp_mb() it's possible for the
     118                 :            :  * waitqueue_active() load to get hoisted over the @cond store such that we'll
     119                 :            :  * observe an empty wait list while the waiter might not observe @cond.
     120                 :            :  *
     121                 :            :  * Also note that this 'optimization' trades a spin_lock() for an smp_mb(),
     122                 :            :  * which (when the lock is uncontended) are of roughly equal cost.
     123                 :            :  */
     124                 :            : static inline int waitqueue_active(struct wait_queue_head *wq_head)
     125                 :            : {
     126                 :   16227920 :         return !list_empty(&wq_head->head);
     127                 :            : }
     128                 :            : 
     129                 :            : /**
     130                 :            :  * wq_has_single_sleeper - check if there is only one sleeper
     131                 :            :  * @wq_head: wait queue head
     132                 :            :  *
     133                 :            :  * Returns true of wq_head has only one sleeper on the list.
     134                 :            :  *
     135                 :            :  * Please refer to the comment for waitqueue_active.
     136                 :            :  */
     137                 :            : static inline bool wq_has_single_sleeper(struct wait_queue_head *wq_head)
     138                 :            : {
     139                 :          0 :         return list_is_singular(&wq_head->head);
     140                 :            : }
     141                 :            : 
     142                 :            : /**
     143                 :            :  * wq_has_sleeper - check if there are any waiting processes
     144                 :            :  * @wq_head: wait queue head
     145                 :            :  *
     146                 :            :  * Returns true if wq_head has waiting processes
     147                 :            :  *
     148                 :            :  * Please refer to the comment for waitqueue_active.
     149                 :            :  */
     150                 :            : static inline bool wq_has_sleeper(struct wait_queue_head *wq_head)
     151                 :            : {
     152                 :            :         /*
     153                 :            :          * We need to be sure we are in sync with the
     154                 :            :          * add_wait_queue modifications to the wait queue.
     155                 :            :          *
     156                 :            :          * This memory barrier should be paired with one on the
     157                 :            :          * waiting side.
     158                 :            :          */
     159                 :    3459305 :         smp_mb();
     160                 :            :         return waitqueue_active(wq_head);
     161                 :            : }
     162                 :            : 
     163                 :            : extern void add_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);
     164                 :            : extern void add_wait_queue_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);
     165                 :            : extern void remove_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);
     166                 :            : 
     167                 :            : static inline void __add_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
     168                 :            : {
     169                 :    4405788 :         list_add(&wq_entry->entry, &wq_head->head);
     170                 :            : }
     171                 :            : 
     172                 :            : /*
     173                 :            :  * Used for wake-one threads:
     174                 :            :  */
     175                 :            : static inline void
     176                 :            : __add_wait_queue_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
     177                 :            : {
     178                 :     681630 :         wq_entry->flags |= WQ_FLAG_EXCLUSIVE;
     179                 :            :         __add_wait_queue(wq_head, wq_entry);
     180                 :            : }
     181                 :            : 
     182                 :            : static inline void __add_wait_queue_entry_tail(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
     183                 :            : {
     184                 :     884141 :         list_add_tail(&wq_entry->entry, &wq_head->head);
     185                 :            : }
     186                 :            : 
     187                 :            : static inline void
     188                 :            : __add_wait_queue_entry_tail_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
     189                 :            : {
     190                 :     250864 :         wq_entry->flags |= WQ_FLAG_EXCLUSIVE;
     191                 :            :         __add_wait_queue_entry_tail(wq_head, wq_entry);
     192                 :            : }
     193                 :            : 
     194                 :            : static inline void
     195                 :            : __remove_wait_queue(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry)
     196                 :            : {
     197                 :            :         list_del(&wq_entry->entry);
     198                 :            : }
     199                 :            : 
     200                 :            : void __wake_up(struct wait_queue_head *wq_head, unsigned int mode, int nr, void *key);
     201                 :            : void __wake_up_locked_key(struct wait_queue_head *wq_head, unsigned int mode, void *key);
     202                 :            : void __wake_up_locked_key_bookmark(struct wait_queue_head *wq_head,
     203                 :            :                 unsigned int mode, void *key, wait_queue_entry_t *bookmark);
     204                 :            : void __wake_up_sync_key(struct wait_queue_head *wq_head, unsigned int mode, int nr, void *key);
     205                 :            : void __wake_up_locked(struct wait_queue_head *wq_head, unsigned int mode, int nr);
     206                 :            : void __wake_up_sync(struct wait_queue_head *wq_head, unsigned int mode, int nr);
     207                 :            : 
     208                 :            : #define wake_up(x)                      __wake_up(x, TASK_NORMAL, 1, NULL)
     209                 :            : #define wake_up_nr(x, nr)               __wake_up(x, TASK_NORMAL, nr, NULL)
     210                 :            : #define wake_up_all(x)                  __wake_up(x, TASK_NORMAL, 0, NULL)
     211                 :            : #define wake_up_locked(x)               __wake_up_locked((x), TASK_NORMAL, 1)
     212                 :            : #define wake_up_all_locked(x)           __wake_up_locked((x), TASK_NORMAL, 0)
     213                 :            : 
     214                 :            : #define wake_up_interruptible(x)        __wake_up(x, TASK_INTERRUPTIBLE, 1, NULL)
     215                 :            : #define wake_up_interruptible_nr(x, nr) __wake_up(x, TASK_INTERRUPTIBLE, nr, NULL)
     216                 :            : #define wake_up_interruptible_all(x)    __wake_up(x, TASK_INTERRUPTIBLE, 0, NULL)
     217                 :            : #define wake_up_interruptible_sync(x)   __wake_up_sync((x), TASK_INTERRUPTIBLE, 1)
     218                 :            : 
     219                 :            : /*
     220                 :            :  * Wakeup macros to be used to report events to the targets.
     221                 :            :  */
     222                 :            : #define poll_to_key(m) ((void *)(__force uintptr_t)(__poll_t)(m))
     223                 :            : #define key_to_poll(m) ((__force __poll_t)(uintptr_t)(void *)(m))
     224                 :            : #define wake_up_poll(x, m)                                                      \
     225                 :            :         __wake_up(x, TASK_NORMAL, 1, poll_to_key(m))
     226                 :            : #define wake_up_locked_poll(x, m)                                               \
     227                 :            :         __wake_up_locked_key((x), TASK_NORMAL, poll_to_key(m))
     228                 :            : #define wake_up_interruptible_poll(x, m)                                        \
     229                 :            :         __wake_up(x, TASK_INTERRUPTIBLE, 1, poll_to_key(m))
     230                 :            : #define wake_up_interruptible_sync_poll(x, m)                                   \
     231                 :            :         __wake_up_sync_key((x), TASK_INTERRUPTIBLE, 1, poll_to_key(m))
     232                 :            : 
     233                 :            : #define ___wait_cond_timeout(condition)                                         \
     234                 :            : ({                                                                              \
     235                 :            :         bool __cond = (condition);                                              \
     236                 :            :         if (__cond && !__ret)                                                   \
     237                 :            :                 __ret = 1;                                                      \
     238                 :            :         __cond || !__ret;                                                       \
     239                 :            : })
     240                 :            : 
     241                 :            : #define ___wait_is_interruptible(state)                                         \
     242                 :            :         (!__builtin_constant_p(state) ||                                        \
     243                 :            :                 state == TASK_INTERRUPTIBLE || state == TASK_KILLABLE)          \
     244                 :            : 
     245                 :            : extern void init_wait_entry(struct wait_queue_entry *wq_entry, int flags);
     246                 :            : 
     247                 :            : /*
     248                 :            :  * The below macro ___wait_event() has an explicit shadow of the __ret
     249                 :            :  * variable when used from the wait_event_*() macros.
     250                 :            :  *
     251                 :            :  * This is so that both can use the ___wait_cond_timeout() construct
     252                 :            :  * to wrap the condition.
     253                 :            :  *
     254                 :            :  * The type inconsistency of the wait_event_*() __ret variable is also
     255                 :            :  * on purpose; we use long where we can return timeout values and int
     256                 :            :  * otherwise.
     257                 :            :  */
     258                 :            : 
     259                 :            : #define ___wait_event(wq_head, condition, state, exclusive, ret, cmd)           \
     260                 :            : ({                                                                              \
     261                 :            :         __label__ __out;                                                        \
     262                 :            :         struct wait_queue_entry __wq_entry;                                     \
     263                 :            :         long __ret = ret;       /* explicit shadow */                           \
     264                 :            :                                                                                 \
     265                 :            :         init_wait_entry(&__wq_entry, exclusive ? WQ_FLAG_EXCLUSIVE : 0);    \
     266                 :            :         for (;;) {                                                              \
     267                 :            :                 long __int = prepare_to_wait_event(&wq_head, &__wq_entry, state);\
     268                 :            :                                                                                 \
     269                 :            :                 if (condition)                                                  \
     270                 :            :                         break;                                                  \
     271                 :            :                                                                                 \
     272                 :            :                 if (___wait_is_interruptible(state) && __int) {                 \
     273                 :            :                         __ret = __int;                                          \
     274                 :            :                         goto __out;                                             \
     275                 :            :                 }                                                               \
     276                 :            :                                                                                 \
     277                 :            :                 cmd;                                                            \
     278                 :            :         }                                                                       \
     279                 :            :         finish_wait(&wq_head, &__wq_entry);                                     \
     280                 :            : __out:  __ret;                                                                  \
     281                 :            : })
     282                 :            : 
     283                 :            : #define __wait_event(wq_head, condition)                                        \
     284                 :            :         (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0,     \
     285                 :            :                             schedule())
     286                 :            : 
     287                 :            : /**
     288                 :            :  * wait_event - sleep until a condition gets true
     289                 :            :  * @wq_head: the waitqueue to wait on
     290                 :            :  * @condition: a C expression for the event to wait for
     291                 :            :  *
     292                 :            :  * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
     293                 :            :  * @condition evaluates to true. The @condition is checked each time
     294                 :            :  * the waitqueue @wq_head is woken up.
     295                 :            :  *
     296                 :            :  * wake_up() has to be called after changing any variable that could
     297                 :            :  * change the result of the wait condition.
     298                 :            :  */
     299                 :            : #define wait_event(wq_head, condition)                                          \
     300                 :            : do {                                                                            \
     301                 :            :         might_sleep();                                                          \
     302                 :            :         if (condition)                                                          \
     303                 :            :                 break;                                                          \
     304                 :            :         __wait_event(wq_head, condition);                                       \
     305                 :            : } while (0)
     306                 :            : 
     307                 :            : #define __io_wait_event(wq_head, condition)                                     \
     308                 :            :         (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0,     \
     309                 :            :                             io_schedule())
     310                 :            : 
     311                 :            : /*
     312                 :            :  * io_wait_event() -- like wait_event() but with io_schedule()
     313                 :            :  */
     314                 :            : #define io_wait_event(wq_head, condition)                                       \
     315                 :            : do {                                                                            \
     316                 :            :         might_sleep();                                                          \
     317                 :            :         if (condition)                                                          \
     318                 :            :                 break;                                                          \
     319                 :            :         __io_wait_event(wq_head, condition);                                    \
     320                 :            : } while (0)
     321                 :            : 
     322                 :            : #define __wait_event_freezable(wq_head, condition)                              \
     323                 :            :         ___wait_event(wq_head, condition, TASK_INTERRUPTIBLE, 0, 0,             \
     324                 :            :                             freezable_schedule())
     325                 :            : 
     326                 :            : /**
     327                 :            :  * wait_event_freezable - sleep (or freeze) until a condition gets true
     328                 :            :  * @wq_head: the waitqueue to wait on
     329                 :            :  * @condition: a C expression for the event to wait for
     330                 :            :  *
     331                 :            :  * The process is put to sleep (TASK_INTERRUPTIBLE -- so as not to contribute
     332                 :            :  * to system load) until the @condition evaluates to true. The
     333                 :            :  * @condition is checked each time the waitqueue @wq_head is woken up.
     334                 :            :  *
     335                 :            :  * wake_up() has to be called after changing any variable that could
     336                 :            :  * change the result of the wait condition.
     337                 :            :  */
     338                 :            : #define wait_event_freezable(wq_head, condition)                                \
     339                 :            : ({                                                                              \
     340                 :            :         int __ret = 0;                                                          \
     341                 :            :         might_sleep();                                                          \
     342                 :            :         if (!(condition))                                                       \
     343                 :            :                 __ret = __wait_event_freezable(wq_head, condition);             \
     344                 :            :         __ret;                                                                  \
     345                 :            : })
     346                 :            : 
     347                 :            : #define __wait_event_timeout(wq_head, condition, timeout)                       \
     348                 :            :         ___wait_event(wq_head, ___wait_cond_timeout(condition),                 \
     349                 :            :                       TASK_UNINTERRUPTIBLE, 0, timeout,                         \
     350                 :            :                       __ret = schedule_timeout(__ret))
     351                 :            : 
     352                 :            : /**
     353                 :            :  * wait_event_timeout - sleep until a condition gets true or a timeout elapses
     354                 :            :  * @wq_head: the waitqueue to wait on
     355                 :            :  * @condition: a C expression for the event to wait for
     356                 :            :  * @timeout: timeout, in jiffies
     357                 :            :  *
     358                 :            :  * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
     359                 :            :  * @condition evaluates to true. The @condition is checked each time
     360                 :            :  * the waitqueue @wq_head is woken up.
     361                 :            :  *
     362                 :            :  * wake_up() has to be called after changing any variable that could
     363                 :            :  * change the result of the wait condition.
     364                 :            :  *
     365                 :            :  * Returns:
     366                 :            :  * 0 if the @condition evaluated to %false after the @timeout elapsed,
     367                 :            :  * 1 if the @condition evaluated to %true after the @timeout elapsed,
     368                 :            :  * or the remaining jiffies (at least 1) if the @condition evaluated
     369                 :            :  * to %true before the @timeout elapsed.
     370                 :            :  */
     371                 :            : #define wait_event_timeout(wq_head, condition, timeout)                         \
     372                 :            : ({                                                                              \
     373                 :            :         long __ret = timeout;                                                   \
     374                 :            :         might_sleep();                                                          \
     375                 :            :         if (!___wait_cond_timeout(condition))                                   \
     376                 :            :                 __ret = __wait_event_timeout(wq_head, condition, timeout);      \
     377                 :            :         __ret;                                                                  \
     378                 :            : })
     379                 :            : 
     380                 :            : #define __wait_event_freezable_timeout(wq_head, condition, timeout)             \
     381                 :            :         ___wait_event(wq_head, ___wait_cond_timeout(condition),                 \
     382                 :            :                       TASK_INTERRUPTIBLE, 0, timeout,                           \
     383                 :            :                       __ret = freezable_schedule_timeout(__ret))
     384                 :            : 
     385                 :            : /*
     386                 :            :  * like wait_event_timeout() -- except it uses TASK_INTERRUPTIBLE to avoid
     387                 :            :  * increasing load and is freezable.
     388                 :            :  */
     389                 :            : #define wait_event_freezable_timeout(wq_head, condition, timeout)               \
     390                 :            : ({                                                                              \
     391                 :            :         long __ret = timeout;                                                   \
     392                 :            :         might_sleep();                                                          \
     393                 :            :         if (!___wait_cond_timeout(condition))                                   \
     394                 :            :                 __ret = __wait_event_freezable_timeout(wq_head, condition, timeout); \
     395                 :            :         __ret;                                                                  \
     396                 :            : })
     397                 :            : 
     398                 :            : #define __wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2)              \
     399                 :            :         (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 1, 0,     \
     400                 :            :                             cmd1; schedule(); cmd2)
     401                 :            : /*
     402                 :            :  * Just like wait_event_cmd(), except it sets exclusive flag
     403                 :            :  */
     404                 :            : #define wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2)                \
     405                 :            : do {                                                                            \
     406                 :            :         if (condition)                                                          \
     407                 :            :                 break;                                                          \
     408                 :            :         __wait_event_exclusive_cmd(wq_head, condition, cmd1, cmd2);             \
     409                 :            : } while (0)
     410                 :            : 
     411                 :            : #define __wait_event_cmd(wq_head, condition, cmd1, cmd2)                        \
     412                 :            :         (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0,     \
     413                 :            :                             cmd1; schedule(); cmd2)
     414                 :            : 
     415                 :            : /**
     416                 :            :  * wait_event_cmd - sleep until a condition gets true
     417                 :            :  * @wq_head: the waitqueue to wait on
     418                 :            :  * @condition: a C expression for the event to wait for
     419                 :            :  * @cmd1: the command will be executed before sleep
     420                 :            :  * @cmd2: the command will be executed after sleep
     421                 :            :  *
     422                 :            :  * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
     423                 :            :  * @condition evaluates to true. The @condition is checked each time
     424                 :            :  * the waitqueue @wq_head is woken up.
     425                 :            :  *
     426                 :            :  * wake_up() has to be called after changing any variable that could
     427                 :            :  * change the result of the wait condition.
     428                 :            :  */
     429                 :            : #define wait_event_cmd(wq_head, condition, cmd1, cmd2)                          \
     430                 :            : do {                                                                            \
     431                 :            :         if (condition)                                                          \
     432                 :            :                 break;                                                          \
     433                 :            :         __wait_event_cmd(wq_head, condition, cmd1, cmd2);                       \
     434                 :            : } while (0)
     435                 :            : 
     436                 :            : #define __wait_event_interruptible(wq_head, condition)                          \
     437                 :            :         ___wait_event(wq_head, condition, TASK_INTERRUPTIBLE, 0, 0,             \
     438                 :            :                       schedule())
     439                 :            : 
     440                 :            : /**
     441                 :            :  * wait_event_interruptible - sleep until a condition gets true
     442                 :            :  * @wq_head: the waitqueue to wait on
     443                 :            :  * @condition: a C expression for the event to wait for
     444                 :            :  *
     445                 :            :  * The process is put to sleep (TASK_INTERRUPTIBLE) until the
     446                 :            :  * @condition evaluates to true or a signal is received.
     447                 :            :  * The @condition is checked each time the waitqueue @wq_head is woken up.
     448                 :            :  *
     449                 :            :  * wake_up() has to be called after changing any variable that could
     450                 :            :  * change the result of the wait condition.
     451                 :            :  *
     452                 :            :  * The function will return -ERESTARTSYS if it was interrupted by a
     453                 :            :  * signal and 0 if @condition evaluated to true.
     454                 :            :  */
     455                 :            : #define wait_event_interruptible(wq_head, condition)                            \
     456                 :            : ({                                                                              \
     457                 :            :         int __ret = 0;                                                          \
     458                 :            :         might_sleep();                                                          \
     459                 :            :         if (!(condition))                                                       \
     460                 :            :                 __ret = __wait_event_interruptible(wq_head, condition);         \
     461                 :            :         __ret;                                                                  \
     462                 :            : })
     463                 :            : 
     464                 :            : #define __wait_event_interruptible_timeout(wq_head, condition, timeout)         \
     465                 :            :         ___wait_event(wq_head, ___wait_cond_timeout(condition),                 \
     466                 :            :                       TASK_INTERRUPTIBLE, 0, timeout,                           \
     467                 :            :                       __ret = schedule_timeout(__ret))
     468                 :            : 
     469                 :            : /**
     470                 :            :  * wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses
     471                 :            :  * @wq_head: the waitqueue to wait on
     472                 :            :  * @condition: a C expression for the event to wait for
     473                 :            :  * @timeout: timeout, in jiffies
     474                 :            :  *
     475                 :            :  * The process is put to sleep (TASK_INTERRUPTIBLE) until the
     476                 :            :  * @condition evaluates to true or a signal is received.
     477                 :            :  * The @condition is checked each time the waitqueue @wq_head is woken up.
     478                 :            :  *
     479                 :            :  * wake_up() has to be called after changing any variable that could
     480                 :            :  * change the result of the wait condition.
     481                 :            :  *
     482                 :            :  * Returns:
     483                 :            :  * 0 if the @condition evaluated to %false after the @timeout elapsed,
     484                 :            :  * 1 if the @condition evaluated to %true after the @timeout elapsed,
     485                 :            :  * the remaining jiffies (at least 1) if the @condition evaluated
     486                 :            :  * to %true before the @timeout elapsed, or -%ERESTARTSYS if it was
     487                 :            :  * interrupted by a signal.
     488                 :            :  */
     489                 :            : #define wait_event_interruptible_timeout(wq_head, condition, timeout)           \
     490                 :            : ({                                                                              \
     491                 :            :         long __ret = timeout;                                                   \
     492                 :            :         might_sleep();                                                          \
     493                 :            :         if (!___wait_cond_timeout(condition))                                   \
     494                 :            :                 __ret = __wait_event_interruptible_timeout(wq_head,             \
     495                 :            :                                                 condition, timeout);            \
     496                 :            :         __ret;                                                                  \
     497                 :            : })
     498                 :            : 
     499                 :            : #define __wait_event_hrtimeout(wq_head, condition, timeout, state)              \
     500                 :            : ({                                                                              \
     501                 :            :         int __ret = 0;                                                          \
     502                 :            :         struct hrtimer_sleeper __t;                                             \
     503                 :            :                                                                                 \
     504                 :            :         hrtimer_init_sleeper_on_stack(&__t, CLOCK_MONOTONIC,                        \
     505                 :            :                                       HRTIMER_MODE_REL);                        \
     506                 :            :         if ((timeout) != KTIME_MAX)                                             \
     507                 :            :                 hrtimer_start_range_ns(&__t.timer, timeout,                 \
     508                 :            :                                        current->timer_slack_ns,                      \
     509                 :            :                                        HRTIMER_MODE_REL);                       \
     510                 :            :                                                                                 \
     511                 :            :         __ret = ___wait_event(wq_head, condition, state, 0, 0,                  \
     512                 :            :                 if (!__t.task) {                                                \
     513                 :            :                         __ret = -ETIME;                                         \
     514                 :            :                         break;                                                  \
     515                 :            :                 }                                                               \
     516                 :            :                 schedule());                                                    \
     517                 :            :                                                                                 \
     518                 :            :         hrtimer_cancel(&__t.timer);                                         \
     519                 :            :         destroy_hrtimer_on_stack(&__t.timer);                                       \
     520                 :            :         __ret;                                                                  \
     521                 :            : })
     522                 :            : 
     523                 :            : /**
     524                 :            :  * wait_event_hrtimeout - sleep until a condition gets true or a timeout elapses
     525                 :            :  * @wq_head: the waitqueue to wait on
     526                 :            :  * @condition: a C expression for the event to wait for
     527                 :            :  * @timeout: timeout, as a ktime_t
     528                 :            :  *
     529                 :            :  * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
     530                 :            :  * @condition evaluates to true or a signal is received.
     531                 :            :  * The @condition is checked each time the waitqueue @wq_head is woken up.
     532                 :            :  *
     533                 :            :  * wake_up() has to be called after changing any variable that could
     534                 :            :  * change the result of the wait condition.
     535                 :            :  *
     536                 :            :  * The function returns 0 if @condition became true, or -ETIME if the timeout
     537                 :            :  * elapsed.
     538                 :            :  */
     539                 :            : #define wait_event_hrtimeout(wq_head, condition, timeout)                       \
     540                 :            : ({                                                                              \
     541                 :            :         int __ret = 0;                                                          \
     542                 :            :         might_sleep();                                                          \
     543                 :            :         if (!(condition))                                                       \
     544                 :            :                 __ret = __wait_event_hrtimeout(wq_head, condition, timeout,     \
     545                 :            :                                                TASK_UNINTERRUPTIBLE);           \
     546                 :            :         __ret;                                                                  \
     547                 :            : })
     548                 :            : 
     549                 :            : /**
     550                 :            :  * wait_event_interruptible_hrtimeout - sleep until a condition gets true or a timeout elapses
     551                 :            :  * @wq: the waitqueue to wait on
     552                 :            :  * @condition: a C expression for the event to wait for
     553                 :            :  * @timeout: timeout, as a ktime_t
     554                 :            :  *
     555                 :            :  * The process is put to sleep (TASK_INTERRUPTIBLE) until the
     556                 :            :  * @condition evaluates to true or a signal is received.
     557                 :            :  * The @condition is checked each time the waitqueue @wq is woken up.
     558                 :            :  *
     559                 :            :  * wake_up() has to be called after changing any variable that could
     560                 :            :  * change the result of the wait condition.
     561                 :            :  *
     562                 :            :  * The function returns 0 if @condition became true, -ERESTARTSYS if it was
     563                 :            :  * interrupted by a signal, or -ETIME if the timeout elapsed.
     564                 :            :  */
     565                 :            : #define wait_event_interruptible_hrtimeout(wq, condition, timeout)              \
     566                 :            : ({                                                                              \
     567                 :            :         long __ret = 0;                                                         \
     568                 :            :         might_sleep();                                                          \
     569                 :            :         if (!(condition))                                                       \
     570                 :            :                 __ret = __wait_event_hrtimeout(wq, condition, timeout,          \
     571                 :            :                                                TASK_INTERRUPTIBLE);             \
     572                 :            :         __ret;                                                                  \
     573                 :            : })
     574                 :            : 
     575                 :            : #define __wait_event_interruptible_exclusive(wq, condition)                     \
     576                 :            :         ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, 0,                  \
     577                 :            :                       schedule())
     578                 :            : 
     579                 :            : #define wait_event_interruptible_exclusive(wq, condition)                       \
     580                 :            : ({                                                                              \
     581                 :            :         int __ret = 0;                                                          \
     582                 :            :         might_sleep();                                                          \
     583                 :            :         if (!(condition))                                                       \
     584                 :            :                 __ret = __wait_event_interruptible_exclusive(wq, condition);    \
     585                 :            :         __ret;                                                                  \
     586                 :            : })
     587                 :            : 
     588                 :            : #define __wait_event_killable_exclusive(wq, condition)                          \
     589                 :            :         ___wait_event(wq, condition, TASK_KILLABLE, 1, 0,                       \
     590                 :            :                       schedule())
     591                 :            : 
     592                 :            : #define wait_event_killable_exclusive(wq, condition)                            \
     593                 :            : ({                                                                              \
     594                 :            :         int __ret = 0;                                                          \
     595                 :            :         might_sleep();                                                          \
     596                 :            :         if (!(condition))                                                       \
     597                 :            :                 __ret = __wait_event_killable_exclusive(wq, condition);         \
     598                 :            :         __ret;                                                                  \
     599                 :            : })
     600                 :            : 
     601                 :            : 
     602                 :            : #define __wait_event_freezable_exclusive(wq, condition)                         \
     603                 :            :         ___wait_event(wq, condition, TASK_INTERRUPTIBLE, 1, 0,                  \
     604                 :            :                         freezable_schedule())
     605                 :            : 
     606                 :            : #define wait_event_freezable_exclusive(wq, condition)                           \
     607                 :            : ({                                                                              \
     608                 :            :         int __ret = 0;                                                          \
     609                 :            :         might_sleep();                                                          \
     610                 :            :         if (!(condition))                                                       \
     611                 :            :                 __ret = __wait_event_freezable_exclusive(wq, condition);        \
     612                 :            :         __ret;                                                                  \
     613                 :            : })
     614                 :            : 
     615                 :            : /**
     616                 :            :  * wait_event_idle - wait for a condition without contributing to system load
     617                 :            :  * @wq_head: the waitqueue to wait on
     618                 :            :  * @condition: a C expression for the event to wait for
     619                 :            :  *
     620                 :            :  * The process is put to sleep (TASK_IDLE) until the
     621                 :            :  * @condition evaluates to true.
     622                 :            :  * The @condition is checked each time the waitqueue @wq_head is woken up.
     623                 :            :  *
     624                 :            :  * wake_up() has to be called after changing any variable that could
     625                 :            :  * change the result of the wait condition.
     626                 :            :  *
     627                 :            :  */
     628                 :            : #define wait_event_idle(wq_head, condition)                                     \
     629                 :            : do {                                                                            \
     630                 :            :         might_sleep();                                                          \
     631                 :            :         if (!(condition))                                                       \
     632                 :            :                 ___wait_event(wq_head, condition, TASK_IDLE, 0, 0, schedule()); \
     633                 :            : } while (0)
     634                 :            : 
     635                 :            : /**
     636                 :            :  * wait_event_idle_exclusive - wait for a condition with contributing to system load
     637                 :            :  * @wq_head: the waitqueue to wait on
     638                 :            :  * @condition: a C expression for the event to wait for
     639                 :            :  *
     640                 :            :  * The process is put to sleep (TASK_IDLE) until the
     641                 :            :  * @condition evaluates to true.
     642                 :            :  * The @condition is checked each time the waitqueue @wq_head is woken up.
     643                 :            :  *
     644                 :            :  * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
     645                 :            :  * set thus if other processes wait on the same list, when this
     646                 :            :  * process is woken further processes are not considered.
     647                 :            :  *
     648                 :            :  * wake_up() has to be called after changing any variable that could
     649                 :            :  * change the result of the wait condition.
     650                 :            :  *
     651                 :            :  */
     652                 :            : #define wait_event_idle_exclusive(wq_head, condition)                           \
     653                 :            : do {                                                                            \
     654                 :            :         might_sleep();                                                          \
     655                 :            :         if (!(condition))                                                       \
     656                 :            :                 ___wait_event(wq_head, condition, TASK_IDLE, 1, 0, schedule()); \
     657                 :            : } while (0)
     658                 :            : 
     659                 :            : #define __wait_event_idle_timeout(wq_head, condition, timeout)                  \
     660                 :            :         ___wait_event(wq_head, ___wait_cond_timeout(condition),                 \
     661                 :            :                       TASK_IDLE, 0, timeout,                                    \
     662                 :            :                       __ret = schedule_timeout(__ret))
     663                 :            : 
     664                 :            : /**
     665                 :            :  * wait_event_idle_timeout - sleep without load until a condition becomes true or a timeout elapses
     666                 :            :  * @wq_head: the waitqueue to wait on
     667                 :            :  * @condition: a C expression for the event to wait for
     668                 :            :  * @timeout: timeout, in jiffies
     669                 :            :  *
     670                 :            :  * The process is put to sleep (TASK_IDLE) until the
     671                 :            :  * @condition evaluates to true. The @condition is checked each time
     672                 :            :  * the waitqueue @wq_head is woken up.
     673                 :            :  *
     674                 :            :  * wake_up() has to be called after changing any variable that could
     675                 :            :  * change the result of the wait condition.
     676                 :            :  *
     677                 :            :  * Returns:
     678                 :            :  * 0 if the @condition evaluated to %false after the @timeout elapsed,
     679                 :            :  * 1 if the @condition evaluated to %true after the @timeout elapsed,
     680                 :            :  * or the remaining jiffies (at least 1) if the @condition evaluated
     681                 :            :  * to %true before the @timeout elapsed.
     682                 :            :  */
     683                 :            : #define wait_event_idle_timeout(wq_head, condition, timeout)                    \
     684                 :            : ({                                                                              \
     685                 :            :         long __ret = timeout;                                                   \
     686                 :            :         might_sleep();                                                          \
     687                 :            :         if (!___wait_cond_timeout(condition))                                   \
     688                 :            :                 __ret = __wait_event_idle_timeout(wq_head, condition, timeout); \
     689                 :            :         __ret;                                                                  \
     690                 :            : })
     691                 :            : 
     692                 :            : #define __wait_event_idle_exclusive_timeout(wq_head, condition, timeout)        \
     693                 :            :         ___wait_event(wq_head, ___wait_cond_timeout(condition),                 \
     694                 :            :                       TASK_IDLE, 1, timeout,                                    \
     695                 :            :                       __ret = schedule_timeout(__ret))
     696                 :            : 
     697                 :            : /**
     698                 :            :  * wait_event_idle_exclusive_timeout - sleep without load until a condition becomes true or a timeout elapses
     699                 :            :  * @wq_head: the waitqueue to wait on
     700                 :            :  * @condition: a C expression for the event to wait for
     701                 :            :  * @timeout: timeout, in jiffies
     702                 :            :  *
     703                 :            :  * The process is put to sleep (TASK_IDLE) until the
     704                 :            :  * @condition evaluates to true. The @condition is checked each time
     705                 :            :  * the waitqueue @wq_head is woken up.
     706                 :            :  *
     707                 :            :  * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
     708                 :            :  * set thus if other processes wait on the same list, when this
     709                 :            :  * process is woken further processes are not considered.
     710                 :            :  *
     711                 :            :  * wake_up() has to be called after changing any variable that could
     712                 :            :  * change the result of the wait condition.
     713                 :            :  *
     714                 :            :  * Returns:
     715                 :            :  * 0 if the @condition evaluated to %false after the @timeout elapsed,
     716                 :            :  * 1 if the @condition evaluated to %true after the @timeout elapsed,
     717                 :            :  * or the remaining jiffies (at least 1) if the @condition evaluated
     718                 :            :  * to %true before the @timeout elapsed.
     719                 :            :  */
     720                 :            : #define wait_event_idle_exclusive_timeout(wq_head, condition, timeout)          \
     721                 :            : ({                                                                              \
     722                 :            :         long __ret = timeout;                                                   \
     723                 :            :         might_sleep();                                                          \
     724                 :            :         if (!___wait_cond_timeout(condition))                                   \
     725                 :            :                 __ret = __wait_event_idle_exclusive_timeout(wq_head, condition, timeout);\
     726                 :            :         __ret;                                                                  \
     727                 :            : })
     728                 :            : 
     729                 :            : extern int do_wait_intr(wait_queue_head_t *, wait_queue_entry_t *);
     730                 :            : extern int do_wait_intr_irq(wait_queue_head_t *, wait_queue_entry_t *);
     731                 :            : 
     732                 :            : #define __wait_event_interruptible_locked(wq, condition, exclusive, fn)         \
     733                 :            : ({                                                                              \
     734                 :            :         int __ret;                                                              \
     735                 :            :         DEFINE_WAIT(__wait);                                                    \
     736                 :            :         if (exclusive)                                                          \
     737                 :            :                 __wait.flags |= WQ_FLAG_EXCLUSIVE;                              \
     738                 :            :         do {                                                                    \
     739                 :            :                 __ret = fn(&(wq), &__wait);                                     \
     740                 :            :                 if (__ret)                                                      \
     741                 :            :                         break;                                                  \
     742                 :            :         } while (!(condition));                                                 \
     743                 :            :         __remove_wait_queue(&(wq), &__wait);                                    \
     744                 :            :         __set_current_state(TASK_RUNNING);                                      \
     745                 :            :         __ret;                                                                  \
     746                 :            : })
     747                 :            : 
     748                 :            : 
     749                 :            : /**
     750                 :            :  * wait_event_interruptible_locked - sleep until a condition gets true
     751                 :            :  * @wq: the waitqueue to wait on
     752                 :            :  * @condition: a C expression for the event to wait for
     753                 :            :  *
     754                 :            :  * The process is put to sleep (TASK_INTERRUPTIBLE) until the
     755                 :            :  * @condition evaluates to true or a signal is received.
     756                 :            :  * The @condition is checked each time the waitqueue @wq is woken up.
     757                 :            :  *
     758                 :            :  * It must be called with wq.lock being held.  This spinlock is
     759                 :            :  * unlocked while sleeping but @condition testing is done while lock
     760                 :            :  * is held and when this macro exits the lock is held.
     761                 :            :  *
     762                 :            :  * The lock is locked/unlocked using spin_lock()/spin_unlock()
     763                 :            :  * functions which must match the way they are locked/unlocked outside
     764                 :            :  * of this macro.
     765                 :            :  *
     766                 :            :  * wake_up_locked() has to be called after changing any variable that could
     767                 :            :  * change the result of the wait condition.
     768                 :            :  *
     769                 :            :  * The function will return -ERESTARTSYS if it was interrupted by a
     770                 :            :  * signal and 0 if @condition evaluated to true.
     771                 :            :  */
     772                 :            : #define wait_event_interruptible_locked(wq, condition)                          \
     773                 :            :         ((condition)                                                            \
     774                 :            :          ? 0 : __wait_event_interruptible_locked(wq, condition, 0, do_wait_intr))
     775                 :            : 
     776                 :            : /**
     777                 :            :  * wait_event_interruptible_locked_irq - sleep until a condition gets true
     778                 :            :  * @wq: the waitqueue to wait on
     779                 :            :  * @condition: a C expression for the event to wait for
     780                 :            :  *
     781                 :            :  * The process is put to sleep (TASK_INTERRUPTIBLE) until the
     782                 :            :  * @condition evaluates to true or a signal is received.
     783                 :            :  * The @condition is checked each time the waitqueue @wq is woken up.
     784                 :            :  *
     785                 :            :  * It must be called with wq.lock being held.  This spinlock is
     786                 :            :  * unlocked while sleeping but @condition testing is done while lock
     787                 :            :  * is held and when this macro exits the lock is held.
     788                 :            :  *
     789                 :            :  * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq()
     790                 :            :  * functions which must match the way they are locked/unlocked outside
     791                 :            :  * of this macro.
     792                 :            :  *
     793                 :            :  * wake_up_locked() has to be called after changing any variable that could
     794                 :            :  * change the result of the wait condition.
     795                 :            :  *
     796                 :            :  * The function will return -ERESTARTSYS if it was interrupted by a
     797                 :            :  * signal and 0 if @condition evaluated to true.
     798                 :            :  */
     799                 :            : #define wait_event_interruptible_locked_irq(wq, condition)                      \
     800                 :            :         ((condition)                                                            \
     801                 :            :          ? 0 : __wait_event_interruptible_locked(wq, condition, 0, do_wait_intr_irq))
     802                 :            : 
     803                 :            : /**
     804                 :            :  * wait_event_interruptible_exclusive_locked - sleep exclusively until a condition gets true
     805                 :            :  * @wq: the waitqueue to wait on
     806                 :            :  * @condition: a C expression for the event to wait for
     807                 :            :  *
     808                 :            :  * The process is put to sleep (TASK_INTERRUPTIBLE) until the
     809                 :            :  * @condition evaluates to true or a signal is received.
     810                 :            :  * The @condition is checked each time the waitqueue @wq is woken up.
     811                 :            :  *
     812                 :            :  * It must be called with wq.lock being held.  This spinlock is
     813                 :            :  * unlocked while sleeping but @condition testing is done while lock
     814                 :            :  * is held and when this macro exits the lock is held.
     815                 :            :  *
     816                 :            :  * The lock is locked/unlocked using spin_lock()/spin_unlock()
     817                 :            :  * functions which must match the way they are locked/unlocked outside
     818                 :            :  * of this macro.
     819                 :            :  *
     820                 :            :  * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
     821                 :            :  * set thus when other process waits process on the list if this
     822                 :            :  * process is awaken further processes are not considered.
     823                 :            :  *
     824                 :            :  * wake_up_locked() has to be called after changing any variable that could
     825                 :            :  * change the result of the wait condition.
     826                 :            :  *
     827                 :            :  * The function will return -ERESTARTSYS if it was interrupted by a
     828                 :            :  * signal and 0 if @condition evaluated to true.
     829                 :            :  */
     830                 :            : #define wait_event_interruptible_exclusive_locked(wq, condition)                \
     831                 :            :         ((condition)                                                            \
     832                 :            :          ? 0 : __wait_event_interruptible_locked(wq, condition, 1, do_wait_intr))
     833                 :            : 
     834                 :            : /**
     835                 :            :  * wait_event_interruptible_exclusive_locked_irq - sleep until a condition gets true
     836                 :            :  * @wq: the waitqueue to wait on
     837                 :            :  * @condition: a C expression for the event to wait for
     838                 :            :  *
     839                 :            :  * The process is put to sleep (TASK_INTERRUPTIBLE) until the
     840                 :            :  * @condition evaluates to true or a signal is received.
     841                 :            :  * The @condition is checked each time the waitqueue @wq is woken up.
     842                 :            :  *
     843                 :            :  * It must be called with wq.lock being held.  This spinlock is
     844                 :            :  * unlocked while sleeping but @condition testing is done while lock
     845                 :            :  * is held and when this macro exits the lock is held.
     846                 :            :  *
     847                 :            :  * The lock is locked/unlocked using spin_lock_irq()/spin_unlock_irq()
     848                 :            :  * functions which must match the way they are locked/unlocked outside
     849                 :            :  * of this macro.
     850                 :            :  *
     851                 :            :  * The process is put on the wait queue with an WQ_FLAG_EXCLUSIVE flag
     852                 :            :  * set thus when other process waits process on the list if this
     853                 :            :  * process is awaken further processes are not considered.
     854                 :            :  *
     855                 :            :  * wake_up_locked() has to be called after changing any variable that could
     856                 :            :  * change the result of the wait condition.
     857                 :            :  *
     858                 :            :  * The function will return -ERESTARTSYS if it was interrupted by a
     859                 :            :  * signal and 0 if @condition evaluated to true.
     860                 :            :  */
     861                 :            : #define wait_event_interruptible_exclusive_locked_irq(wq, condition)            \
     862                 :            :         ((condition)                                                            \
     863                 :            :          ? 0 : __wait_event_interruptible_locked(wq, condition, 1, do_wait_intr_irq))
     864                 :            : 
     865                 :            : 
     866                 :            : #define __wait_event_killable(wq, condition)                                    \
     867                 :            :         ___wait_event(wq, condition, TASK_KILLABLE, 0, 0, schedule())
     868                 :            : 
     869                 :            : /**
     870                 :            :  * wait_event_killable - sleep until a condition gets true
     871                 :            :  * @wq_head: the waitqueue to wait on
     872                 :            :  * @condition: a C expression for the event to wait for
     873                 :            :  *
     874                 :            :  * The process is put to sleep (TASK_KILLABLE) until the
     875                 :            :  * @condition evaluates to true or a signal is received.
     876                 :            :  * The @condition is checked each time the waitqueue @wq_head is woken up.
     877                 :            :  *
     878                 :            :  * wake_up() has to be called after changing any variable that could
     879                 :            :  * change the result of the wait condition.
     880                 :            :  *
     881                 :            :  * The function will return -ERESTARTSYS if it was interrupted by a
     882                 :            :  * signal and 0 if @condition evaluated to true.
     883                 :            :  */
     884                 :            : #define wait_event_killable(wq_head, condition)                                 \
     885                 :            : ({                                                                              \
     886                 :            :         int __ret = 0;                                                          \
     887                 :            :         might_sleep();                                                          \
     888                 :            :         if (!(condition))                                                       \
     889                 :            :                 __ret = __wait_event_killable(wq_head, condition);              \
     890                 :            :         __ret;                                                                  \
     891                 :            : })
     892                 :            : 
     893                 :            : #define __wait_event_killable_timeout(wq_head, condition, timeout)              \
     894                 :            :         ___wait_event(wq_head, ___wait_cond_timeout(condition),                 \
     895                 :            :                       TASK_KILLABLE, 0, timeout,                                \
     896                 :            :                       __ret = schedule_timeout(__ret))
     897                 :            : 
     898                 :            : /**
     899                 :            :  * wait_event_killable_timeout - sleep until a condition gets true or a timeout elapses
     900                 :            :  * @wq_head: the waitqueue to wait on
     901                 :            :  * @condition: a C expression for the event to wait for
     902                 :            :  * @timeout: timeout, in jiffies
     903                 :            :  *
     904                 :            :  * The process is put to sleep (TASK_KILLABLE) until the
     905                 :            :  * @condition evaluates to true or a kill signal is received.
     906                 :            :  * The @condition is checked each time the waitqueue @wq_head is woken up.
     907                 :            :  *
     908                 :            :  * wake_up() has to be called after changing any variable that could
     909                 :            :  * change the result of the wait condition.
     910                 :            :  *
     911                 :            :  * Returns:
     912                 :            :  * 0 if the @condition evaluated to %false after the @timeout elapsed,
     913                 :            :  * 1 if the @condition evaluated to %true after the @timeout elapsed,
     914                 :            :  * the remaining jiffies (at least 1) if the @condition evaluated
     915                 :            :  * to %true before the @timeout elapsed, or -%ERESTARTSYS if it was
     916                 :            :  * interrupted by a kill signal.
     917                 :            :  *
     918                 :            :  * Only kill signals interrupt this process.
     919                 :            :  */
     920                 :            : #define wait_event_killable_timeout(wq_head, condition, timeout)                \
     921                 :            : ({                                                                              \
     922                 :            :         long __ret = timeout;                                                   \
     923                 :            :         might_sleep();                                                          \
     924                 :            :         if (!___wait_cond_timeout(condition))                                   \
     925                 :            :                 __ret = __wait_event_killable_timeout(wq_head,                  \
     926                 :            :                                                 condition, timeout);            \
     927                 :            :         __ret;                                                                  \
     928                 :            : })
     929                 :            : 
     930                 :            : 
     931                 :            : #define __wait_event_lock_irq(wq_head, condition, lock, cmd)                    \
     932                 :            :         (void)___wait_event(wq_head, condition, TASK_UNINTERRUPTIBLE, 0, 0,     \
     933                 :            :                             spin_unlock_irq(&lock);                         \
     934                 :            :                             cmd;                                                \
     935                 :            :                             schedule();                                         \
     936                 :            :                             spin_lock_irq(&lock))
     937                 :            : 
     938                 :            : /**
     939                 :            :  * wait_event_lock_irq_cmd - sleep until a condition gets true. The
     940                 :            :  *                           condition is checked under the lock. This
     941                 :            :  *                           is expected to be called with the lock
     942                 :            :  *                           taken.
     943                 :            :  * @wq_head: the waitqueue to wait on
     944                 :            :  * @condition: a C expression for the event to wait for
     945                 :            :  * @lock: a locked spinlock_t, which will be released before cmd
     946                 :            :  *        and schedule() and reacquired afterwards.
     947                 :            :  * @cmd: a command which is invoked outside the critical section before
     948                 :            :  *       sleep
     949                 :            :  *
     950                 :            :  * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
     951                 :            :  * @condition evaluates to true. The @condition is checked each time
     952                 :            :  * the waitqueue @wq_head is woken up.
     953                 :            :  *
     954                 :            :  * wake_up() has to be called after changing any variable that could
     955                 :            :  * change the result of the wait condition.
     956                 :            :  *
     957                 :            :  * This is supposed to be called while holding the lock. The lock is
     958                 :            :  * dropped before invoking the cmd and going to sleep and is reacquired
     959                 :            :  * afterwards.
     960                 :            :  */
     961                 :            : #define wait_event_lock_irq_cmd(wq_head, condition, lock, cmd)                  \
     962                 :            : do {                                                                            \
     963                 :            :         if (condition)                                                          \
     964                 :            :                 break;                                                          \
     965                 :            :         __wait_event_lock_irq(wq_head, condition, lock, cmd);                   \
     966                 :            : } while (0)
     967                 :            : 
     968                 :            : /**
     969                 :            :  * wait_event_lock_irq - sleep until a condition gets true. The
     970                 :            :  *                       condition is checked under the lock. This
     971                 :            :  *                       is expected to be called with the lock
     972                 :            :  *                       taken.
     973                 :            :  * @wq_head: the waitqueue to wait on
     974                 :            :  * @condition: a C expression for the event to wait for
     975                 :            :  * @lock: a locked spinlock_t, which will be released before schedule()
     976                 :            :  *        and reacquired afterwards.
     977                 :            :  *
     978                 :            :  * The process is put to sleep (TASK_UNINTERRUPTIBLE) until the
     979                 :            :  * @condition evaluates to true. The @condition is checked each time
     980                 :            :  * the waitqueue @wq_head is woken up.
     981                 :            :  *
     982                 :            :  * wake_up() has to be called after changing any variable that could
     983                 :            :  * change the result of the wait condition.
     984                 :            :  *
     985                 :            :  * This is supposed to be called while holding the lock. The lock is
     986                 :            :  * dropped before going to sleep and is reacquired afterwards.
     987                 :            :  */
     988                 :            : #define wait_event_lock_irq(wq_head, condition, lock)                           \
     989                 :            : do {                                                                            \
     990                 :            :         if (condition)                                                          \
     991                 :            :                 break;                                                          \
     992                 :            :         __wait_event_lock_irq(wq_head, condition, lock, );                      \
     993                 :            : } while (0)
     994                 :            : 
     995                 :            : 
     996                 :            : #define __wait_event_interruptible_lock_irq(wq_head, condition, lock, cmd)      \
     997                 :            :         ___wait_event(wq_head, condition, TASK_INTERRUPTIBLE, 0, 0,             \
     998                 :            :                       spin_unlock_irq(&lock);                                       \
     999                 :            :                       cmd;                                                      \
    1000                 :            :                       schedule();                                               \
    1001                 :            :                       spin_lock_irq(&lock))
    1002                 :            : 
    1003                 :            : /**
    1004                 :            :  * wait_event_interruptible_lock_irq_cmd - sleep until a condition gets true.
    1005                 :            :  *              The condition is checked under the lock. This is expected to
    1006                 :            :  *              be called with the lock taken.
    1007                 :            :  * @wq_head: the waitqueue to wait on
    1008                 :            :  * @condition: a C expression for the event to wait for
    1009                 :            :  * @lock: a locked spinlock_t, which will be released before cmd and
    1010                 :            :  *        schedule() and reacquired afterwards.
    1011                 :            :  * @cmd: a command which is invoked outside the critical section before
    1012                 :            :  *       sleep
    1013                 :            :  *
    1014                 :            :  * The process is put to sleep (TASK_INTERRUPTIBLE) until the
    1015                 :            :  * @condition evaluates to true or a signal is received. The @condition is
    1016                 :            :  * checked each time the waitqueue @wq_head is woken up.
    1017                 :            :  *
    1018                 :            :  * wake_up() has to be called after changing any variable that could
    1019                 :            :  * change the result of the wait condition.
    1020                 :            :  *
    1021                 :            :  * This is supposed to be called while holding the lock. The lock is
    1022                 :            :  * dropped before invoking the cmd and going to sleep and is reacquired
    1023                 :            :  * afterwards.
    1024                 :            :  *
    1025                 :            :  * The macro will return -ERESTARTSYS if it was interrupted by a signal
    1026                 :            :  * and 0 if @condition evaluated to true.
    1027                 :            :  */
    1028                 :            : #define wait_event_interruptible_lock_irq_cmd(wq_head, condition, lock, cmd)    \
    1029                 :            : ({                                                                              \
    1030                 :            :         int __ret = 0;                                                          \
    1031                 :            :         if (!(condition))                                                       \
    1032                 :            :                 __ret = __wait_event_interruptible_lock_irq(wq_head,            \
    1033                 :            :                                                 condition, lock, cmd);          \
    1034                 :            :         __ret;                                                                  \
    1035                 :            : })
    1036                 :            : 
    1037                 :            : /**
    1038                 :            :  * wait_event_interruptible_lock_irq - sleep until a condition gets true.
    1039                 :            :  *              The condition is checked under the lock. This is expected
    1040                 :            :  *              to be called with the lock taken.
    1041                 :            :  * @wq_head: the waitqueue to wait on
    1042                 :            :  * @condition: a C expression for the event to wait for
    1043                 :            :  * @lock: a locked spinlock_t, which will be released before schedule()
    1044                 :            :  *        and reacquired afterwards.
    1045                 :            :  *
    1046                 :            :  * The process is put to sleep (TASK_INTERRUPTIBLE) until the
    1047                 :            :  * @condition evaluates to true or signal is received. The @condition is
    1048                 :            :  * checked each time the waitqueue @wq_head is woken up.
    1049                 :            :  *
    1050                 :            :  * wake_up() has to be called after changing any variable that could
    1051                 :            :  * change the result of the wait condition.
    1052                 :            :  *
    1053                 :            :  * This is supposed to be called while holding the lock. The lock is
    1054                 :            :  * dropped before going to sleep and is reacquired afterwards.
    1055                 :            :  *
    1056                 :            :  * The macro will return -ERESTARTSYS if it was interrupted by a signal
    1057                 :            :  * and 0 if @condition evaluated to true.
    1058                 :            :  */
    1059                 :            : #define wait_event_interruptible_lock_irq(wq_head, condition, lock)             \
    1060                 :            : ({                                                                              \
    1061                 :            :         int __ret = 0;                                                          \
    1062                 :            :         if (!(condition))                                                       \
    1063                 :            :                 __ret = __wait_event_interruptible_lock_irq(wq_head,            \
    1064                 :            :                                                 condition, lock,);              \
    1065                 :            :         __ret;                                                                  \
    1066                 :            : })
    1067                 :            : 
    1068                 :            : #define __wait_event_lock_irq_timeout(wq_head, condition, lock, timeout, state) \
    1069                 :            :         ___wait_event(wq_head, ___wait_cond_timeout(condition),                 \
    1070                 :            :                       state, 0, timeout,                                        \
    1071                 :            :                       spin_unlock_irq(&lock);                                       \
    1072                 :            :                       __ret = schedule_timeout(__ret);                          \
    1073                 :            :                       spin_lock_irq(&lock));
    1074                 :            : 
    1075                 :            : /**
    1076                 :            :  * wait_event_interruptible_lock_irq_timeout - sleep until a condition gets
    1077                 :            :  *              true or a timeout elapses. The condition is checked under
    1078                 :            :  *              the lock. This is expected to be called with the lock taken.
    1079                 :            :  * @wq_head: the waitqueue to wait on
    1080                 :            :  * @condition: a C expression for the event to wait for
    1081                 :            :  * @lock: a locked spinlock_t, which will be released before schedule()
    1082                 :            :  *        and reacquired afterwards.
    1083                 :            :  * @timeout: timeout, in jiffies
    1084                 :            :  *
    1085                 :            :  * The process is put to sleep (TASK_INTERRUPTIBLE) until the
    1086                 :            :  * @condition evaluates to true or signal is received. The @condition is
    1087                 :            :  * checked each time the waitqueue @wq_head is woken up.
    1088                 :            :  *
    1089                 :            :  * wake_up() has to be called after changing any variable that could
    1090                 :            :  * change the result of the wait condition.
    1091                 :            :  *
    1092                 :            :  * This is supposed to be called while holding the lock. The lock is
    1093                 :            :  * dropped before going to sleep and is reacquired afterwards.
    1094                 :            :  *
    1095                 :            :  * The function returns 0 if the @timeout elapsed, -ERESTARTSYS if it
    1096                 :            :  * was interrupted by a signal, and the remaining jiffies otherwise
    1097                 :            :  * if the condition evaluated to true before the timeout elapsed.
    1098                 :            :  */
    1099                 :            : #define wait_event_interruptible_lock_irq_timeout(wq_head, condition, lock,     \
    1100                 :            :                                                   timeout)                      \
    1101                 :            : ({                                                                              \
    1102                 :            :         long __ret = timeout;                                                   \
    1103                 :            :         if (!___wait_cond_timeout(condition))                                   \
    1104                 :            :                 __ret = __wait_event_lock_irq_timeout(                          \
    1105                 :            :                                         wq_head, condition, lock, timeout,      \
    1106                 :            :                                         TASK_INTERRUPTIBLE);                    \
    1107                 :            :         __ret;                                                                  \
    1108                 :            : })
    1109                 :            : 
    1110                 :            : #define wait_event_lock_irq_timeout(wq_head, condition, lock, timeout)          \
    1111                 :            : ({                                                                              \
    1112                 :            :         long __ret = timeout;                                                   \
    1113                 :            :         if (!___wait_cond_timeout(condition))                                   \
    1114                 :            :                 __ret = __wait_event_lock_irq_timeout(                          \
    1115                 :            :                                         wq_head, condition, lock, timeout,      \
    1116                 :            :                                         TASK_UNINTERRUPTIBLE);                  \
    1117                 :            :         __ret;                                                                  \
    1118                 :            : })
    1119                 :            : 
    1120                 :            : /*
    1121                 :            :  * Waitqueues which are removed from the waitqueue_head at wakeup time
    1122                 :            :  */
    1123                 :            : void prepare_to_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);
    1124                 :            : void prepare_to_wait_exclusive(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);
    1125                 :            : long prepare_to_wait_event(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry, int state);
    1126                 :            : void finish_wait(struct wait_queue_head *wq_head, struct wait_queue_entry *wq_entry);
    1127                 :            : long wait_woken(struct wait_queue_entry *wq_entry, unsigned mode, long timeout);
    1128                 :            : int woken_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key);
    1129                 :            : int autoremove_wake_function(struct wait_queue_entry *wq_entry, unsigned mode, int sync, void *key);
    1130                 :            : 
    1131                 :            : #define DEFINE_WAIT_FUNC(name, function)                                        \
    1132                 :            :         struct wait_queue_entry name = {                                        \
    1133                 :            :                 .private        = current,                                      \
    1134                 :            :                 .func           = function,                                     \
    1135                 :            :                 .entry          = LIST_HEAD_INIT((name).entry),                 \
    1136                 :            :         }
    1137                 :            : 
    1138                 :            : #define DEFINE_WAIT(name) DEFINE_WAIT_FUNC(name, autoremove_wake_function)
    1139                 :            : 
    1140                 :            : #define init_wait(wait)                                                         \
    1141                 :            :         do {                                                                    \
    1142                 :            :                 (wait)->private = current;                                   \
    1143                 :            :                 (wait)->func = autoremove_wake_function;                     \
    1144                 :            :                 INIT_LIST_HEAD(&(wait)->entry);                                  \
    1145                 :            :                 (wait)->flags = 0;                                           \
    1146                 :            :         } while (0)
    1147                 :            : 
    1148                 :            : #endif /* _LINUX_WAIT_H */

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