blob: 6771c1da5d788ec49478a0473e4aa6455e3cff42 [file] [log] [blame]
Jens Wiklanderc5231592015-11-11 09:27:27 +01001/*
2 * Copyright (c) 2015, Linaro Limited
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice,
9 * this list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright notice,
12 * this list of conditions and the following disclaimer in the documentation
13 * and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
19 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
20 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
21 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
22 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
23 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
24 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25 * POSSIBILITY OF SUCH DAMAGE.
26 */
27
28/* uint32_t atomic_inc(uint32_t *v); */
29.global atomic_inc
30.func atomic_inc
31atomic_inc:
32 ldaxr w1, [x0]
33 add w1, w1, #1
34 stxr w2, w1, [x0]
35 cmp w2, #0
36 bne atomic_inc
37 mov w0, w1
38 ret
39.endfunc
40
41/* uint32_t atomic_dec(uint32_t *v); */
42.global atomic_dec
43.func atomic_dec
44atomic_dec:
45 ldaxr w1, [x0]
46 sub w1, w1, #1
47 stxr w2, w1, [x0]
48 cmp w2, #0
49 bne atomic_dec
50 mov w0, w1
51 ret
52.endfunc
53