1/*	$NetBSD: atomic_swap_32_cas.c,v 1.3 2007/11/28 16:59:11 ad Exp $	*/
2
3/*-
4 * Copyright (c) 2007 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Jason R. Thorpe.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#include "atomic_op_namespace.h"
33
34#include <sys/atomic.h>
35
36uint32_t
37atomic_swap_32(volatile uint32_t *addr, uint32_t new)
38{
39	uint32_t old;
40
41	do {
42		old = *addr;
43	} while (atomic_cas_32(addr, old, new) != old);
44
45	return (old);
46}
47
48#undef atomic_swap_32
49atomic_op_alias(atomic_swap_32,_atomic_swap_32)
50#undef atomic_swap_uint
51atomic_op_alias(atomic_swap_uint,_atomic_swap_32)
52__strong_alias(_atomic_swap_uint,_atomic_swap_32)
53#if !defined(_LP64)
54#undef atomic_swap_ulong
55atomic_op_alias(atomic_swap_ulong,_atomic_swap_32)
56__strong_alias(_atomic_swap_ulong,_atomic_swap_32)
57#undef atomic_swap_ptr
58atomic_op_alias(atomic_swap_ptr,_atomic_swap_32)
59__strong_alias(_atomic_swap_ptr,_atomic_swap_32)
60#endif /* _LP64 */
61