xref: /freebsd/sys/compat/linuxkpi/common/include/linux/semaphore.h (revision 95ee2897e98f5d444f26ed2334cc7c439f9c16c6)
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 #ifndef _LINUXKPI_LINUX_SEMAPHORE_H_
30 #define _LINUXKPI_LINUX_SEMAPHORE_H_
31 
32 #include <sys/param.h>
33 #include <sys/lock.h>
34 #include <sys/sema.h>
35 #include <sys/libkern.h>
36 
37 /*
38  * XXX BSD semaphores are disused and slow.  They also do not provide a
39  * sema_wait_sig method.  This must be resolved eventually.
40  */
41 struct semaphore {
42 	struct sema	sema;
43 };
44 
45 #define	down(_sem)			sema_wait(&(_sem)->sema)
46 #define	down_interruptible(_sem)	sema_wait(&(_sem)->sema), 0
47 #define	down_trylock(_sem)		!sema_trywait(&(_sem)->sema)
48 #define	up(_sem)			sema_post(&(_sem)->sema)
49 
50 static inline void
linux_sema_init(struct semaphore * sem,int val)51 linux_sema_init(struct semaphore *sem, int val)
52 {
53 
54 	memset(&sem->sema, 0, sizeof(sem->sema));
55 	sema_init(&sem->sema, val, "lnxsema");
56 }
57 
58 static inline void
init_MUTEX(struct semaphore * sem)59 init_MUTEX(struct semaphore *sem)
60 {
61 
62 	memset(&sem->sema, 0, sizeof(sem->sema));
63 	sema_init(&sem->sema, 1, "lnxsema");
64 }
65 
66 #define	sema_init(...)	linux_sema_init(__VA_ARGS__)
67 
68 #endif /* _LINUXKPI_LINUX_SEMAPHORE_H_ */
69