1/*	$NetBSD: atomic_swap.S,v 1.4 2008/05/25 15:56:11 chs 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_asm.h"
33
34	.text
35
36ENTRY(_atomic_swap_32)
37	movl	%sp@(4), %a0
381:	movl	%a0@, %d0
39	movl	%sp@(8), %d1
40	casl	%d0, %d1, %a0@
41	bne	1b
42	/* %d0 now contains the old value */
43	movl	%d0, %a0	/* pointers return also in %a0 */
44	rts
45ATOMIC_OP_ALIAS(atomic_swap_32,_atomic_swap_32)
46ATOMIC_OP_ALIAS(atomic_swap_uint,_atomic_swap_32)
47STRONG_ALIAS(_atomic_swap_uint,_atomic_swap_32)
48ATOMIC_OP_ALIAS(atomic_swap_ulong,_atomic_swap_32)
49STRONG_ALIAS(_atomic_swap_ulong,_atomic_swap_32)
50ATOMIC_OP_ALIAS(atomic_swap_ptr,_atomic_swap_32)
51STRONG_ALIAS(_atomic_swap_ptr,_atomic_swap_32)
52