1/*	$NetBSD: atomic_swap_64.S,v 1.7 2013/11/30 21:09:11 joerg Exp $	*/
2/*-
3 * Copyright (c) 2012 The NetBSD Foundation, Inc.
4 * All rights reserved.
5 *
6 * This code is derived from software contributed to The NetBSD Foundation
7 * by Matt Thomas.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
19 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
20 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
22 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include "atomic_op_asm.h"
32
33ENTRY_NP(_atomic_swap_64)
34	push	{r3,r4}			/* save temporary */
35	mov	ip, r0			/* return value will be in r0 */
36#ifndef __ARM_EABI__
37	mov	r3, r2			/* r2 will be overwriten by r1 */
38	mov	r2, r1			/* and r1 will be overwritten by ldrexd */
39#endif
401:	ldrexd	r0, r1, [ip]		/* load old value */
41	strexd	r4, r2, r3, [ip]	/* store new value */
42	cmp	r4, #0			/*   succeed? */
43	bne	1b			/*    no, try again */
44#ifdef _ARM_ARCH_7
45	dmb
46#else
47	mcr	p15, 0, r4, c7, c10, 5	/* data memory barrier */
48#endif
49	pop	{r3,r4}			/* restore temporary */
50	RET
51END(_atomic_swap_64)
52ATOMIC_OP_ALIAS(atomic_swap_64,_atomic_swap_64)
53STRONG_ALIAS(__sync_lock_test_and_set_8,_atomic_swap_64)
54
55ENTRY_NP(__sync_lock_release_8)
56	mov	r2, #0
57	mov	r3, #0
58	strd	r2, r3, [r0]
59	RET
60END(__sync_lock_release_8)
61