2 * Copyright (c) 2010 Isilon Systems, Inc.
3 * Copyright (c) 2010 iX Systems, Inc.
4 * Copyright (c) 2010 Panasas, Inc.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice unmodified, this list of conditions, and the following
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 #ifndef _LINUX_RWSEM_H_
29 #define _LINUX_RWSEM_H_
31 #include <sys/param.h>
39 #define down_write(_rw) sx_xlock(&(_rw)->sx)
40 #define up_write(_rw) sx_xunlock(&(_rw)->sx)
41 #define down_read(_rw) sx_slock(&(_rw)->sx)
42 #define up_read(_rw) sx_sunlock(&(_rw)->sx)
43 #define down_read_trylock(_rw) !!sx_try_slock(&(_rw)->sx)
44 #define down_write_trylock(_rw) !!sx_try_xlock(&(_rw)->sx)
45 #define downgrade_write(_rw) sx_downgrade(&(_rw)->sx)
46 #define down_read_nested(_rw, _sc) down_read(_rw)
49 init_rwsem(struct rw_semaphore *rw)
52 memset(&rw->sx, 0, sizeof(rw->sx));
53 sx_init_flags(&rw->sx, "lnxrwsem", SX_NOWITNESS);
56 #endif /* _LINUX_RWSEM_H_ */