1/*	$NetBSD: atomic_xor_8.S,v 1.3 2014/06/23 21:53:45 joerg Exp $	*/
2
3/*-
4 * Copyright (c) 2013 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Matt Thomas <matt@3am-software.com>
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#ifdef _ARM_ARCH_6
35
36ENTRY_NP(_atomic_xor_8)
37	mov	ip, r0
381:	ldrexb	r0, [ip]		/* load old value (to be returned) */
39	eors	r3, r0, r1		/* calculate new value */
40	strexb	r2, r3, [ip]		/* try to store */
41	cmp	r2, #0			/*   succeed? */
42	bne	1b			/*     no, try again */
43#ifdef _ARM_ARCH_7
44	dmb
45#else
46	mcr	p15, 0, r2, c7, c10, 5	/* data memory barrier */
47#endif
48	RET				/* return old value */
49END(_atomic_xor_8)
50
51ATOMIC_OP_ALIAS(atomic_xor_8,_atomic_xor_8)
52ATOMIC_OP_ALIAS(atomic_xor_uchar,_atomic_xor_8)
53CRT_ALIAS(__sync_fetch_and_xor_1,_atomic_xor_8)
54CRT_ALIAS(__atomic_fetch_xor_1,_atomic_xor_8)
55STRONG_ALIAS(_atomic_xor_uchar,_atomic_xor_8)
56
57ENTRY_NP(_atomic_xor_8_nv)
58	mov	ip, r0			/* need r0 for return value */
591:	ldrexb	r0, [ip]		/* load old value */
60	eors	r0, r0, r1		/* calculate new value (return value) */
61	strexb	r2, r0, [ip]		/* try to store */
62	cmp	r2, #0			/*   succeed? */
63	bne	1b			/*     no, try again? */
64#ifdef _ARM_ARCH_7
65	dmb
66#else
67	mcr	p15, 0, r2, c7, c10, 5	/* data memory barrier */
68#endif
69	RET				/* return new value */
70END(_atomic_xor_8_nv)
71
72ATOMIC_OP_ALIAS(atomic_xor_8_nv,_atomic_xor_8_nv)
73ATOMIC_OP_ALIAS(atomic_xor_uchar_nv,_atomic_xor_8_nv)
74CRT_ALIAS(__sync_xor_and_fetch_1,_atomic_xor_8_nv)
75STRONG_ALIAS(_atomic_xor_uchar_nv,_atomic_xor_8_nv)
76
77#endif /* _ARM_ARCH_6 */
78