xref: /optee_os/lib/libutils/ext/arch/arm/atomic_a32.S (revision 1bb929836182ecb96d2d9d268daa807c67596396)
1/* SPDX-License-Identifier: BSD-2-Clause */
2/*
3 * Copyright (c) 2015-2016, Linaro Limited
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright notice,
10 * this list of conditions and the following disclaimer.
11 *
12 * 2. Redistributions in binary form must reproduce the above copyright notice,
13 * this list of conditions and the following disclaimer in the documentation
14 * and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#include <asm.S>
30
31/* uint32_t atomic_inc32(uint32_t *v); */
32FUNC atomic_inc32 , :
33	ldrex	r1, [r0]
34	add	r1, r1, #1
35	strex	r2, r1, [r0]
36	cmp	r2, #0
37	bne	atomic_inc32
38	mov	r0, r1
39	bx	lr
40END_FUNC atomic_inc32
41
42/* uint32_t atomic_dec32(uint32_t *v); */
43FUNC atomic_dec32 , :
44	ldrex	r1, [r0]
45	sub	r1, r1, #1
46	strex	r2, r1, [r0]
47	cmp	r2, #0
48	bne	atomic_dec32
49	mov	r0, r1
50	bx	lr
51END_FUNC atomic_dec32
52