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       1                 :            : /* SPDX-License-Identifier: GPL-2.0 */
       2                 :            : #ifndef __LINUX_COMPLETION_H
       3                 :            : #define __LINUX_COMPLETION_H
       4                 :            : 
       5                 :            : /*
       6                 :            :  * (C) Copyright 2001 Linus Torvalds
       7                 :            :  *
       8                 :            :  * Atomic wait-for-completion handler data structures.
       9                 :            :  * See kernel/sched/completion.c for details.
      10                 :            :  */
      11                 :            : 
      12                 :            : #include <linux/wait.h>
      13                 :            : 
      14                 :            : /*
      15                 :            :  * struct completion - structure used to maintain state for a "completion"
      16                 :            :  *
      17                 :            :  * This is the opaque structure used to maintain the state for a "completion".
      18                 :            :  * Completions currently use a FIFO to queue threads that have to wait for
      19                 :            :  * the "completion" event.
      20                 :            :  *
      21                 :            :  * See also:  complete(), wait_for_completion() (and friends _timeout,
      22                 :            :  * _interruptible, _interruptible_timeout, and _killable), init_completion(),
      23                 :            :  * reinit_completion(), and macros DECLARE_COMPLETION(),
      24                 :            :  * DECLARE_COMPLETION_ONSTACK().
      25                 :            :  */
      26                 :            : struct completion {
      27                 :            :         unsigned int done;
      28                 :            :         wait_queue_head_t wait;
      29                 :            : };
      30                 :            : 
      31                 :            : #define init_completion_map(x, m) __init_completion(x)
      32                 :            : #define init_completion(x) __init_completion(x)
      33                 :            : static inline void complete_acquire(struct completion *x) {}
      34                 :            : static inline void complete_release(struct completion *x) {}
      35                 :            : 
      36                 :            : #define COMPLETION_INITIALIZER(work) \
      37                 :            :         { 0, __WAIT_QUEUE_HEAD_INITIALIZER((work).wait) }
      38                 :            : 
      39                 :            : #define COMPLETION_INITIALIZER_ONSTACK_MAP(work, map) \
      40                 :            :         (*({ init_completion_map(&(work), &(map)); &(work); }))
      41                 :            : 
      42                 :            : #define COMPLETION_INITIALIZER_ONSTACK(work) \
      43                 :            :         (*({ init_completion(&work); &work; }))
      44                 :            : 
      45                 :            : /**
      46                 :            :  * DECLARE_COMPLETION - declare and initialize a completion structure
      47                 :            :  * @work:  identifier for the completion structure
      48                 :            :  *
      49                 :            :  * This macro declares and initializes a completion structure. Generally used
      50                 :            :  * for static declarations. You should use the _ONSTACK variant for automatic
      51                 :            :  * variables.
      52                 :            :  */
      53                 :            : #define DECLARE_COMPLETION(work) \
      54                 :            :         struct completion work = COMPLETION_INITIALIZER(work)
      55                 :            : 
      56                 :            : /*
      57                 :            :  * Lockdep needs to run a non-constant initializer for on-stack
      58                 :            :  * completions - so we use the _ONSTACK() variant for those that
      59                 :            :  * are on the kernel stack:
      60                 :            :  */
      61                 :            : /**
      62                 :            :  * DECLARE_COMPLETION_ONSTACK - declare and initialize a completion structure
      63                 :            :  * @work:  identifier for the completion structure
      64                 :            :  *
      65                 :            :  * This macro declares and initializes a completion structure on the kernel
      66                 :            :  * stack.
      67                 :            :  */
      68                 :            : #ifdef CONFIG_LOCKDEP
      69                 :            : # define DECLARE_COMPLETION_ONSTACK(work) \
      70                 :            :         struct completion work = COMPLETION_INITIALIZER_ONSTACK(work)
      71                 :            : # define DECLARE_COMPLETION_ONSTACK_MAP(work, map) \
      72                 :            :         struct completion work = COMPLETION_INITIALIZER_ONSTACK_MAP(work, map)
      73                 :            : #else
      74                 :            : # define DECLARE_COMPLETION_ONSTACK(work) DECLARE_COMPLETION(work)
      75                 :            : # define DECLARE_COMPLETION_ONSTACK_MAP(work, map) DECLARE_COMPLETION(work)
      76                 :            : #endif
      77                 :            : 
      78                 :            : /**
      79                 :            :  * init_completion - Initialize a dynamically allocated completion
      80                 :            :  * @x:  pointer to completion structure that is to be initialized
      81                 :            :  *
      82                 :            :  * This inline function will initialize a dynamically created completion
      83                 :            :  * structure.
      84                 :            :  */
      85                 :            : static inline void __init_completion(struct completion *x)
      86                 :            : {
      87                 :    6161336 :         x->done = 0;
      88                 :    6161336 :         init_waitqueue_head(&x->wait);
      89                 :            : }
      90                 :            : 
      91                 :            : /**
      92                 :            :  * reinit_completion - reinitialize a completion structure
      93                 :            :  * @x:  pointer to completion structure that is to be reinitialized
      94                 :            :  *
      95                 :            :  * This inline function should be used to reinitialize a completion structure so it can
      96                 :            :  * be reused. This is especially important after complete_all() is used.
      97                 :            :  */
      98                 :            : static inline void reinit_completion(struct completion *x)
      99                 :            : {
     100                 :      45664 :         x->done = 0;
     101                 :            : }
     102                 :            : 
     103                 :            : extern void wait_for_completion(struct completion *);
     104                 :            : extern void wait_for_completion_io(struct completion *);
     105                 :            : extern int wait_for_completion_interruptible(struct completion *x);
     106                 :            : extern int wait_for_completion_killable(struct completion *x);
     107                 :            : extern unsigned long wait_for_completion_timeout(struct completion *x,
     108                 :            :                                                    unsigned long timeout);
     109                 :            : extern unsigned long wait_for_completion_io_timeout(struct completion *x,
     110                 :            :                                                     unsigned long timeout);
     111                 :            : extern long wait_for_completion_interruptible_timeout(
     112                 :            :         struct completion *x, unsigned long timeout);
     113                 :            : extern long wait_for_completion_killable_timeout(
     114                 :            :         struct completion *x, unsigned long timeout);
     115                 :            : extern bool try_wait_for_completion(struct completion *x);
     116                 :            : extern bool completion_done(struct completion *x);
     117                 :            : 
     118                 :            : extern void complete(struct completion *);
     119                 :            : extern void complete_all(struct completion *);
     120                 :            : 
     121                 :            : #endif