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Achin Gupta4f6ad662013-10-25 09:08:21 +01001/*
Dan Handleye83b0ca2014-01-14 18:17:09 +00002 * Copyright (c) 2013-2014, ARM Limited and Contributors. All rights reserved.
Achin Gupta4f6ad662013-10-25 09:08:21 +01003 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are met:
6 *
7 * Redistributions of source code must retain the above copyright notice, this
8 * list of conditions and the following disclaimer.
9 *
10 * Redistributions in binary form must reproduce the above copyright notice,
11 * this list of conditions and the following disclaimer in the documentation
12 * and/or other materials provided with the distribution.
13 *
14 * Neither the name of ARM nor the names of its contributors may be used
15 * to endorse or promote products derived from this software without specific
16 * prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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29 */
30
Andrew Thoelke38bde412014-03-18 13:46:55 +000031#include <asm_macros.S>
32
Achin Gupta4f6ad662013-10-25 09:08:21 +010033 .globl spin_lock
34 .globl spin_unlock
35
36
Andrew Thoelke38bde412014-03-18 13:46:55 +000037func spin_lock
Achin Gupta4f6ad662013-10-25 09:08:21 +010038 mov w2, #1
39 sevl
40l1: wfe
41l2: ldaxr w1, [x0]
42 cbnz w1, l1
43 stxr w1, w2, [x0]
44 cbnz w1, l2
45 ret
Kévin Petita877c252015-03-24 14:03:57 +000046endfunc spin_lock
Achin Gupta4f6ad662013-10-25 09:08:21 +010047
48
Andrew Thoelke38bde412014-03-18 13:46:55 +000049func spin_unlock
Achin Gupta4f6ad662013-10-25 09:08:21 +010050 stlr wzr, [x0]
51 ret
Kévin Petita877c252015-03-24 14:03:57 +000052endfunc spin_unlock