1/*
2 * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
17 */
18#ifndef __XFS_SUPPORT_SEMA_H__
19#define __XFS_SUPPORT_SEMA_H__
20
21#include <linux/time.h>
22#include <linux/wait.h>
23#include <asm/atomic.h>
24#include <asm/semaphore.h>
25
26/*
27 * sema_t structure just maps to struct semaphore in Linux kernel.
28 */
29
30typedef struct semaphore sema_t;
31
32#define initnsema(sp, val, name)	sema_init(sp, val)
33#define psema(sp, b)			down(sp)
34#define vsema(sp)			up(sp)
35#define freesema(sema)			do { } while (0)
36
37static inline int issemalocked(sema_t *sp)
38{
39	return down_trylock(sp) || (up(sp), 0);
40}
41
42/*
43 * Map cpsema (try to get the sema) to down_trylock. We need to switch
44 * the return values since cpsema returns 1 (acquired) 0 (failed) and
45 * down_trylock returns the reverse 0 (acquired) 1 (failed).
46 */
47static inline int cpsema(sema_t *sp)
48{
49	return down_trylock(sp) ? 0 : 1;
50}
51
52#endif /* __XFS_SUPPORT_SEMA_H__ */
53