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/*-
* Copyright (c) 2010 Isilon Systems, Inc.
* Copyright (c) 2010 iX Systems, Inc.
* Copyright (c) 2010 Panasas, Inc.
* Copyright (c) 2013-2017 Mellanox Technologies, Ltd.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice unmodified, this list of conditions, and the following
* disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _LINUXKPI_LINUX_RWSEM_H_
#define _LINUXKPI_LINUX_RWSEM_H_
#include <sys/param.h>
#include <sys/lock.h>
#include <sys/sx.h>
#include <sys/libkern.h>
#include <sys/kernel.h>
struct rw_semaphore {
struct sx sx;
};
#define down_write(_rw) sx_xlock(&(_rw)->sx)
#define up_write(_rw) sx_xunlock(&(_rw)->sx)
#define down_read(_rw) sx_slock(&(_rw)->sx)
#define up_read(_rw) sx_sunlock(&(_rw)->sx)
#define down_read_trylock(_rw) !!sx_try_slock(&(_rw)->sx)
#define down_read_killable(_rw) linux_down_read_killable(_rw)
#define down_write_trylock(_rw) !!sx_try_xlock(&(_rw)->sx)
#define down_write_killable(_rw) linux_down_write_killable(_rw)
#define downgrade_write(_rw) sx_downgrade(&(_rw)->sx)
#define down_read_nested(_rw, _sc) down_read(_rw)
#define init_rwsem(_rw) linux_init_rwsem(_rw, rwsem_name("lnxrwsem"))
#define down_write_nest_lock(sem, _rw) down_write(_rw)
#ifdef WITNESS_ALL
/* NOTE: the maximum WITNESS name is 64 chars */
#define __rwsem_name(name, file, line) \
(((const char *){file ":" #line "-" name}) + \
(sizeof(file) > 16 ? sizeof(file) - 16 : 0))
#else
#define __rwsem_name(name, file, line) name
#endif
#define _rwsem_name(...) __rwsem_name(__VA_ARGS__)
#define rwsem_name(name) _rwsem_name(name, __FILE__, __LINE__)
#define DECLARE_RWSEM(name) \
struct rw_semaphore name; \
static void name##_rwsem_init(void *arg) \
{ \
linux_init_rwsem(&name, rwsem_name(#name)); \
} \
SYSINIT(name, SI_SUB_LOCK, SI_ORDER_SECOND, name##_rwsem_init, NULL)
static inline void
linux_init_rwsem(struct rw_semaphore *rw, const char *name)
{
memset(rw, 0, sizeof(*rw));
sx_init_flags(&rw->sx, name, SX_NOWITNESS);
}
extern int linux_down_read_killable(struct rw_semaphore *);
extern int linux_down_write_killable(struct rw_semaphore *);
#endif /* _LINUXKPI_LINUX_RWSEM_H_ */
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