minix/common/lib/libc/arch/arm/atomic/atomic_cas_64.S
Lionel Sambuc 84d9c625bf Synchronize on NetBSD-CVS (2013/12/1 12:00:00 UTC)
- Fix for possible unset uid/gid in toproto
 - Fix for default mtree style
 - Update libelf
 - Importing libexecinfo
 - Resynchronize GCC, mpc, gmp, mpfr
 - build.sh: Replace params with show-params.
     This has been done as the make target has been renamed in the same
     way, while a new target named params has been added. This new
     target generates a file containing all the parameters, instead of
     printing it on the console.
 - Update test48 with new etc/services (Fix by Ben Gras <ben@minix3.org)
     get getservbyport() out of the inner loop

Change-Id: Ie6ad5226fa2621ff9f0dee8782ea48f9443d2091
2014-07-28 17:05:06 +02:00

75 lines
2.8 KiB
ArmAsm

/* $NetBSD: atomic_cas_64.S,v 1.5 2013/11/30 21:09:11 joerg Exp $ */
/*-
* Copyright (c) 2012 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"
#if defined(_ARM_ARCH_6)
/*
* ARMv6 has load-exclusive/store-exclusive which works for both user
* and kernel.
*/
ENTRY_NP(_atomic_cas_64)
push {r4, r5, r6} /* save temporaries */
mov ip, r0 /* we need r0 for return value */
#ifdef __ARM_EABI__
ldrd r4, r5, [sp] /* fetch new value */
#else
ldr r4, [sp, #0] /* fetch new value */
ldr r5, [sp, #4] /* fetch new value */
mov r3, r2 /* r2 will be overwritten by r1 which ... */
mov r2, r1 /* r1 will be overwritten by ldrexd */
#endif
1:
ldrexd r0, r1, [ip] /* load current value */
cmp r0, r2 /* compare to old? 1st half */
#ifdef __thumb__
bne 2f /* jump to return if different */
cmp r1, r3 /* compare to old? 2nd half */
#else
cmpeq r1, r3 /* compare to old? 2nd half */
#endif
bne 2f /* jump to return if different */
strexd r6, r4, r5, [ip] /* store new value */
cmp r6, #0 /* succeed? */
bne 1b /* nope, try again. */
#ifdef _ARM_ARCH_7
dsb
#else
mcr p15, 0, ip, c7, c10, 4 /* data synchronization barrier */
#endif
2:
pop {r4, r5, r6} /* restore temporaries */
RET /* return. */
END(_atomic_cas_64)
ATOMIC_OP_ALIAS(atomic_cas_64,_atomic_cas_64)
STRONG_ALIAS(__sync_val_compare_and_swap_8,_atomic_cas_64)
#endif /* _ARM_ARCH_6 */