2 * Copyright 2004 by Peter Grehan. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 * 3. The name of the author may not be used to endorse or promote products
13 * derived from this software without specific prior written permission.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
20 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
21 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
22 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
23 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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30 #ifndef _ATOMIC_OPS_H_
31 #define _ATOMIC_OPS_H_
35 * Atomic (tmp = *dst, *dst = val), then *res = tmp
37 * void atomic_swap32(intptr_t *dst, intptr_t val, intptr_t *res);
40 atomic_swap32(volatile intptr_t *dst, intptr_t val, intptr_t *res)
44 tmp = 0; /* should be a better way to quieten cc1... */
47 "1: lwarx %0, 0, %4\n" /* load with reservation */
48 " stwcx. %3, 0, %4\n" /* attempt to store val */
49 " bne- 1b\n" /* interrupted? retry */
50 " stw %0, %1\n" /* else, *dst -> *res */
51 : "=&r" (tmp), "=m" (*res), "+m" (*dst)
52 : "r" (val), "r" (dst)
57 #define atomic_swap_ptr(d, v, r) \
58 atomic_swap32((volatile intptr_t *)d, (intptr_t)v, (intptr_t *)r)
60 #define atomic_swap_int(d, v, r) \
61 atomic_swap32((volatile intptr_t *)d, (intptr_t)v, (intptr_t *)r)