xref: /minix3/common/lib/libc/arch/arm/atomic/atomic_swap_64.S (revision 0a6a1f1d05b60e214de2f05a7310ddd1f0e590e7)
1*0a6a1f1dSLionel Sambuc/*	$NetBSD: atomic_swap_64.S,v 1.10 2015/05/17 20:57:11 justin Exp $	*/
2f14fb602SLionel Sambuc/*-
3f14fb602SLionel Sambuc * Copyright (c) 2012 The NetBSD Foundation, Inc.
4f14fb602SLionel Sambuc * All rights reserved.
5f14fb602SLionel Sambuc *
6f14fb602SLionel Sambuc * This code is derived from software contributed to The NetBSD Foundation
7f14fb602SLionel Sambuc * by Matt Thomas.
8f14fb602SLionel Sambuc *
9f14fb602SLionel Sambuc * Redistribution and use in source and binary forms, with or without
10f14fb602SLionel Sambuc * modification, are permitted provided that the following conditions
11f14fb602SLionel Sambuc * are met:
12f14fb602SLionel Sambuc * 1. Redistributions of source code must retain the above copyright
13f14fb602SLionel Sambuc *    notice, this list of conditions and the following disclaimer.
14f14fb602SLionel Sambuc * 2. Redistributions in binary form must reproduce the above copyright
15f14fb602SLionel Sambuc *    notice, this list of conditions and the following disclaimer in the
16f14fb602SLionel Sambuc *    documentation and/or other materials provided with the distribution.
17f14fb602SLionel Sambuc *
18f14fb602SLionel Sambuc * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
19f14fb602SLionel Sambuc * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
20f14fb602SLionel Sambuc * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
21f14fb602SLionel Sambuc * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
22f14fb602SLionel Sambuc * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23f14fb602SLionel Sambuc * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24f14fb602SLionel Sambuc * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25f14fb602SLionel Sambuc * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26f14fb602SLionel Sambuc * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27f14fb602SLionel Sambuc * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28f14fb602SLionel Sambuc * POSSIBILITY OF SUCH DAMAGE.
29f14fb602SLionel Sambuc */
30f14fb602SLionel Sambuc
31f14fb602SLionel Sambuc#include "atomic_op_asm.h"
32f14fb602SLionel Sambuc
33f14fb602SLionel SambucENTRY_NP(_atomic_swap_64)
3484d9c625SLionel Sambuc	push	{r3,r4}			/* save temporary */
3584d9c625SLionel Sambuc	mov	ip, r0			/* return value will be in r0 */
36f14fb602SLionel Sambuc#ifndef __ARM_EABI__
37f14fb602SLionel Sambuc	mov	r3, r2			/* r2 will be overwriten by r1 */
38f14fb602SLionel Sambuc	mov	r2, r1			/* and r1 will be overwritten by ldrexd */
39f14fb602SLionel Sambuc#endif
4084d9c625SLionel Sambuc1:	ldrexd	r0, r1, [ip]		/* load old value */
4184d9c625SLionel Sambuc	strexd	r4, r2, r3, [ip]	/* store new value */
4284d9c625SLionel Sambuc	cmp	r4, #0			/*   succeed? */
43f14fb602SLionel Sambuc	bne	1b			/*    no, try again */
44f14fb602SLionel Sambuc#ifdef _ARM_ARCH_7
45f14fb602SLionel Sambuc	dmb
46f14fb602SLionel Sambuc#else
4784d9c625SLionel Sambuc	mcr	p15, 0, r4, c7, c10, 5	/* data memory barrier */
48f14fb602SLionel Sambuc#endif
4984d9c625SLionel Sambuc	pop	{r3,r4}			/* restore temporary */
50f14fb602SLionel Sambuc	RET
51f14fb602SLionel SambucEND(_atomic_swap_64)
52f14fb602SLionel SambucATOMIC_OP_ALIAS(atomic_swap_64,_atomic_swap_64)
53*0a6a1f1dSLionel SambucCRT_ALIAS(__sync_lock_test_and_set_8,_atomic_swap_64)
54*0a6a1f1dSLionel SambucCRT_ALIAS(__atomic_exchange_8,_atomic_swap_64)
5584d9c625SLionel Sambuc
56*0a6a1f1dSLionel Sambuc#if (!defined(_KERNEL) || !defined(_RUMPKERNEL)) && !defined(_STANDALONE)
5784d9c625SLionel SambucENTRY_NP(__sync_lock_release_8)
5884d9c625SLionel Sambuc	mov	r2, #0
5984d9c625SLionel Sambuc	mov	r3, #0
6084d9c625SLionel Sambuc	strd	r2, r3, [r0]
6184d9c625SLionel Sambuc	RET
6284d9c625SLionel SambucEND(__sync_lock_release_8)
63*0a6a1f1dSLionel Sambuc#endif
64