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