1/* SPDX-License-Identifier: BSD-3-Clause */
2/*
3 * Copyright (c) 2016, Linaro Limited
4 * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
5 * Copyright (c) 2014, STMicroelectronics International N.V.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright notice,
12 * this list of conditions and the following disclaimer.
13 *
14 * 2. Redistributions in binary form must reproduce the above copyright notice,
15 * this list of conditions and the following disclaimer in the documentation
16 * and/or other materials provided with the distribution.
17 *
18 * Neither the name of ARM nor the names of its contributors may be used
19 * to endorse or promote products derived from this software without specific
20 * prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
23 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
26 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
28 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
29 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
30 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
31 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32 * POSSIBILITY OF SUCH DAMAGE.
33 */
34
35#include <asm.S>
36#include <kernel/spinlock.h>
37
38/* void __cpu_spin_lock(unsigned int *lock) */
39FUNC __cpu_spin_lock , :
40	mov r2, #SPINLOCK_LOCK
411:
42	ldrex r1, [r0]
43	cmp r1, #SPINLOCK_UNLOCK
44	wfene
45	strexeq r1, r2, [r0]
46	cmpeq r1, #0
47	bne 1b
48	dmb
49	bx lr
50END_FUNC __cpu_spin_lock
51
52/* int __cpu_spin_trylock(unsigned int *lock) - return 0 on success */
53FUNC __cpu_spin_trylock , :
54	mov r2, #SPINLOCK_LOCK
55	mov r1, r0
561:
57	ldrex r0, [r1]
58	cmp r0, #0
59	bne 1f
60	strex r0, r2, [r1]
61	cmp r0, #0
62	bne 1b
63	dmb
64	bx lr
651:
66	clrex
67	dmb
68	bx lr
69END_FUNC __cpu_spin_trylock
70
71/* void __cpu_spin_unlock(unsigned int *lock) */
72FUNC __cpu_spin_unlock , :
73	dmb
74	mov r1, #SPINLOCK_UNLOCK
75	str r1, [r0]
76	dsb
77	sev
78	bx lr
79END_FUNC __cpu_spin_unlock
80