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_RWSEM_H_ 32 #define _LINUX_RWSEM_H_ 33 34 #include <sys/param.h> 35 #include <sys/lock.h> 36 #include <sys/sx.h> 37 38 struct rw_semaphore { 39 struct sx sx; 40 }; 41 42 #define down_write(_rw) sx_xlock(&(_rw)->sx) 43 #define up_write(_rw) sx_xunlock(&(_rw)->sx) 44 #define down_read(_rw) sx_slock(&(_rw)->sx) 45 #define up_read(_rw) sx_sunlock(&(_rw)->sx) 46 #define down_read_trylock(_rw) !!sx_try_slock(&(_rw)->sx) 47 #define down_write_trylock(_rw) !!sx_try_xlock(&(_rw)->sx) 48 #define downgrade_write(_rw) sx_downgrade(&(_rw)->sx) 49 #define down_read_nested(_rw, _sc) down_read(_rw) 50 51 static inline void 52 init_rwsem(struct rw_semaphore *rw) 53 { 54 55 memset(&rw->sx, 0, sizeof(rw->sx)); 56 sx_init_flags(&rw->sx, "lnxrwsem", SX_NOWITNESS); 57 } 58 59 #endif /* _LINUX_RWSEM_H_ */ 60