include/linux/semaphore.h

   1 /*
   2  * Copyright (c) 2008 Intel Corporation
   3  * Author: Matthew Wilcox <willy@linux.intel.com>
   4  *
   5  * Distributed under the terms of the GNU GPL, version 2
   6  *
   7  * Please see kernel/semaphore.c for documentation of these functions
   8  */
   9 #ifndef __LINUX_SEMAPHORE_H
  10 #define __LINUX_SEMAPHORE_H
  11
  12 #ifndef CONFIG_PREEMPT_RT
  13 # define compat_semaphore semaphore
  14 #endif
  15
  16 # include <linux/list.h>
  17 # include <linux/spinlock.h>
  18
  19 /* Please don't access any members of this structure directly */
  20 struct compat_semaphore {
  21         spinlock_t              lock;
  22         unsigned int            count;
  23         struct list_head        wait_list;
  24 };
  25
  26 #define __COMPAT_SEMAPHORE_INITIALIZER(name, n)                         \
  27 {                                                                       \
  28         .lock           = __SPIN_LOCK_UNLOCKED((name).lock),            \
  29         .count          = n,                                            \
  30         .wait_list      = LIST_HEAD_INIT((name).wait_list),             \
  31 }
  32
  33 #define __COMPAT_DECLARE_SEMAPHORE_GENERIC(name, count) \
  34         struct compat_semaphore name = __COMPAT_SEMAPHORE_INITIALIZER(name, count)
  35
  36 #define COMPAT_DECLARE_MUTEX(name)      __COMPAT_DECLARE_SEMAPHORE_GENERIC(name, 1)
  37 static inline void compat_sema_init(struct compat_semaphore *sem, int val)
  38 {
  39         static struct lock_class_key __key;
  40         *sem = (struct compat_semaphore) __COMPAT_SEMAPHORE_INITIALIZER(*sem, val);
  41
  42         spin_lock_init(&sem->lock);
  43         lockdep_init_map(&sem->lock.dep_map, "semaphore->lock", &__key, 0);
  44 }
  45
  46 #define compat_init_MUTEX(sem)          compat_sema_init(sem, 1)
  47 #define compat_init_MUTEX_LOCKED(sem)   compat_sema_init(sem, 0)
  48
  49 extern void compat_down(struct compat_semaphore *sem);
  50 extern int __must_check compat_down_interruptible(struct compat_semaphore *sem);
  51 extern int __must_check compat_down_killable(struct compat_semaphore *sem);
  52 extern int __must_check compat_down_trylock(struct compat_semaphore *sem);
  53 extern int __must_check compat_down_timeout(struct compat_semaphore *sem, long jiffies);
  54 extern void compat_up(struct compat_semaphore *sem);
  55
  56 #ifdef CONFIG_PREEMPT_RT
  57 # include <linux/rt_lock.h>
  58 #else
  59 #define DECLARE_MUTEX COMPAT_DECLARE_MUTEX
  60
  61 static inline void sema_init(struct compat_semaphore *sem, int val)
  62 {
  63         compat_sema_init(sem, val);
  64 }
  65 static inline void init_MUTEX(struct compat_semaphore *sem)
  66 {
  67         compat_init_MUTEX(sem);
  68 }
  69 static inline void init_MUTEX_LOCKED(struct compat_semaphore *sem)
  70 {
  71         compat_init_MUTEX_LOCKED(sem);
  72 }
  73 static inline void down(struct compat_semaphore *sem)
  74 {
  75         compat_down(sem);
  76 }
  77 static inline int down_interruptible(struct compat_semaphore *sem)
  78 {
  79         return compat_down_interruptible(sem);
  80 }
  81 static inline int down_trylock(struct compat_semaphore *sem)
  82 {
  83         return compat_down_trylock(sem);
  84 }
  85 static inline int down_timeout(struct compat_semaphore *sem, long jiffies)
  86 {
  87         return compat_down_timeout(sem, jiffies);
  88 }
  89
  90 static inline void up(struct compat_semaphore *sem)
  91 {
  92         compat_up(sem);
  93 }
  94 #endif /* CONFIG_PREEMPT_RT */
  95
  96 #endif /* __LINUX_SEMAPHORE_H */