1/*
2 * Copyright (c) 2014 Google Inc. All rights reserved
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining
5 * a copy of this software and associated documentation files
6 * (the "Software"), to deal in the Software without restriction,
7 * including without limitation the rights to use, copy, modify, merge,
8 * publish, distribute, sublicense, and/or sell copies of the Software,
9 * and to permit persons to whom the Software is furnished to do so,
10 * subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be
13 * included in all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
18 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
19 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
20 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
21 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
22 */
23#include <asm.h>
24
25.text
26
27FUNCTION(arch_spin_trylock)
28	mov	x2, x0
29	mov	x1, #1
30	ldaxr	x0, [x2]
31	cbnz	x0, 1f
32	stxr	w0, x1, [x2]
331:
34	ret
35
36FUNCTION(arch_spin_lock)
37	mov	x1, #1
38	sevl
391:
40	wfe
41	ldaxr	x2, [x0]
42	cbnz	x2, 1b
43	stxr	w2, x1, [x0]
44	cbnz	w2, 1b
45	ret
46
47FUNCTION(arch_spin_unlock)
48	stlr	xzr, [x0]
49	ret
50