xref: /freebsd/sys/compat/linuxkpi/common/include/linux/semaphore.h (revision d8a0fe102c0cfdfcd5b818f850eff09d8536c9bc)
1 /*-
2  * Copyright (c) 2010 Isilon Systems, Inc.
3  * Copyright (c) 2010 iX Systems, Inc.
4  * Copyright (c) 2010 Panasas, Inc.
5  * Copyright (c) 2013, 2014 Mellanox Technologies, Ltd.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice unmodified, this list of conditions, and the following
13  *    disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  *
29  * $FreeBSD$
30  */
31 #ifndef _LINUX_SEMAPHORE_H_
32 #define _LINUX_SEMAPHORE_H_
33 
34 #include <sys/param.h>
35 #include <sys/lock.h>
36 #include <sys/sema.h>
37 #include <sys/libkern.h>
38 
39 /*
40  * XXX BSD semaphores are disused and slow.  They also do not provide a
41  * sema_wait_sig method.  This must be resolved eventually.
42  */
43 struct semaphore {
44 	struct sema	sema;
45 };
46 
47 #define	down(_sem)			sema_wait(&(_sem)->sema)
48 #define	down_interruptible(_sem)	sema_wait(&(_sem)->sema), 0
49 #define	down_trylock(_sem)		!sema_trywait(&(_sem)->sema)
50 #define	up(_sem)			sema_post(&(_sem)->sema)
51 
52 static inline void
53 linux_sema_init(struct semaphore *sem, int val)
54 {
55 
56 	memset(&sem->sema, 0, sizeof(sem->sema));
57 	sema_init(&sem->sema, val, "lnxsema");
58 }
59 
60 static inline void
61 init_MUTEX(struct semaphore *sem)
62 {
63 
64 	memset(&sem->sema, 0, sizeof(sem->sema));
65 	sema_init(&sem->sema, 1, "lnxsema");
66 }
67 
68 #define	sema_init	linux_sema_init
69 
70 #endif /* _LINUX_SEMAPHORE_H_ */
71