# 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_I386_ATOMIC_H
    00020 #define _RTAI_ASM_I386_ATOMIC_H
    00021
    00022 #include <linux/bitops.h>
    00023 #include <asm/atomic.h>
    00024
    00025 #ifdef __KERNEL__
    00026
    00027 #include <asm/system.h>
    00028
    00029 #define atomic_xchg(ptr,v)      xchg(ptr,v)
    00030 #define atomic_cmpxchg(ptr,o,n) cmpxchg(ptr,o,n)
    00031
    00032 #else /* !__KERNEL__ */
    00033
    00034 struct __rtai_xchg_dummy { unsigned long a[100]; };
    00035 #define __rtai_xg(x) ((struct __rtai_xchg_dummy *)(x))
    00036
    00037 static inline unsigned long atomic_xchg (volatile void *ptr,
    00038                                          unsigned long x)
    00039 {
    00040     __asm__ __volatile__(LOCK_PREFIX "xchgl %0,%1"
    00041                          :"=r" (x)
    00042                          :"m" (*__rtai_xg(ptr)), "0" (x)
    00043                          :"memory");
    00044     return x;
    00045 }
    00046
    00047 static inline unsigned long atomic_cmpxchg (volatile void *ptr,
    00048                                             unsigned long o,
    00049                                             unsigned long n)
    00050 {
    00051     unsigned long prev;
    00052
    00053     __asm__ __volatile__(LOCK_PREFIX "cmpxchgl %1,%2"
    00054                          : "=a"(prev)
    00055                          : "q"(n), "m" (*__rtai_xg(ptr)), "0" (o)
    00056                          : "memory");
    00057
    00058     return prev;
    00059 }
    00060
    00061 /* Depollute the namespace a bit. */
    00062 #undef ADDR
    00063
    00064 #endif /* __KERNEL__ */
    00065
    00066 #endif /* !_RTAI_ASM_I386_ATOMIC_H */