# rtai_atomic.h

    00001 /*
    00002  * Copyright (C) 2003 Philippe Gerum <rpm@xenomai.org>.
    00003  *
    00004  * This program is free software; you can redistribute it and/or
    00005  * modify it under the terms of the GNU General Public License as
    00006  * published by the Free Software Foundation; either version 2 of the
    00007  * License, or (at your option) any later version.
    00008  *
    00009  * This program is distributed in the hope that it will be useful,
    00010  * but WITHOUT ANY WARRANTY; without even the implied warranty of
    00011  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    00012  * GNU General Public License for more details.
    00013  *
    00014  * You should have received a copy of the GNU General Public License
    00015  * along with this program; if not, write to the Free Software
    00016  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
    00017  */
    00018
    00019 #ifndef _RTAI_ASM_ARM_ATOMIC_H
    00020 #define _RTAI_ASM_ARM_ATOMIC_H
    00021
    00022 #ifdef __KERNEL__
    00023
    00024 #include <linux/bitops.h>
    00025 #include <asm/system.h>
    00026
    00027 #define atomic_xchg(ptr,v)      xchg(ptr,v)
    00028
    00029 /* Poor man's cmpxchg(). */
    00030 #define atomic_cmpxchg(p, o, n) ({      \
    00031         typeof(*(p)) __o = (o);         \
    00032         typeof(*(p)) __n = (n);         \
    00033         typeof(*(p)) __prev;            \
    00034         unsigned long flags;            \
    00035         hard_save_flags_and_cli(flags); \
    00036         __prev = *(p);                  \
    00037         if (__prev == __o)              \
    00038                 *(p) = __n;             \
    00039         hard_restore_flags(flags);      \
    00040         __prev; })
    00041
    00042 #endif /* __KERNEL__ */
    00043
    00044 #endif /* !_RTAI_ASM_ARM_ATOMIC_H */