minix/common/lib/libc/arch/arm/atomic/sync_fetch_and_nand_8.S

61 lines
2.2 KiB
ArmAsm

/* $NetBSD: sync_fetch_and_nand_8.S,v 1.2 2013/11/30 21:09:11 joerg Exp $ */
/*-
* Copyright (c) 2013 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Matt Thomas <matt@3am-software.com>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "atomic_op_asm.h"
#ifdef _ARM_ARCH_6
ENTRY_NP(__sync_fetch_and_nand_8)
push {r4-r7}
mov ip, r0
#ifndef __ARM__EABI__
mov r3, r2
mov r2, r1
#endif
1: ldrexd r0, r1, [ip] /* load old value */
mvns r4, r0 /* complement old value */
mvns r5, r0 /* complement old value */
ands r4, r4, r2 /* calculate new value */
ands r5, r5, r3 /* calculate new value */
strexd r6, r4, r5, [ip] /* try to store */
cmp r6, #0 /* succeed? */
bne 1b /* no, try again */
#ifdef _ARM_ARCH_7
dmb
#else
mcr p15, 0, r2, c7, c10, 5 /* data memory barrier */
#endif
pop {r4-r7}
RET /* return old value */
END(__sync_fetch_and_nand_8)
#endif /* _ARM_ARCH_6 */