f14fb60209
* Updating common/lib * Updating lib/csu * Updating lib/libc * Updating libexec/ld.elf_so * Corrected test on __minix in featuretest to actually follow the meaning of the comment. * Cleaned up _REENTRANT-related defintions. * Disabled -D_REENTRANT for libfetch * Removing some unneeded __NBSD_LIBC defines and tests Change-Id: Ic1394baef74d11b9f86b312f5ff4bbc3cbf72ce2
100 lines
3.3 KiB
ArmAsm
100 lines
3.3 KiB
ArmAsm
/* $NetBSD: atomic_swap.S,v 1.4 2012/08/31 23:41:52 matt Exp $ */
|
|
|
|
/*-
|
|
* Copyright (c) 2007,2012 The NetBSD Foundation, Inc.
|
|
* All rights reserved.
|
|
*
|
|
* This code is derived from software contributed to The NetBSD Foundation
|
|
* by Jason R. Thorpe and Matt Thomas.
|
|
*
|
|
* 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"
|
|
|
|
/*
|
|
* While SWP{B} is sufficient on its own for pre-ARMv7 CPUs, on MP ARMv7 cores
|
|
* SWP{B} is disabled since it's no longer atomic among multiple CPUs. They
|
|
* will actually raise an UNDEFINED exception.
|
|
*
|
|
* So if we use the LDREX/STREX template, but use a SWP instruction followed
|
|
* by a MOV instruction (using a temporary register), that gives a handler
|
|
* for the SWP UNDEFINED exception enough information to "patch" this instance
|
|
* SWP with correct forms of LDREX/STREX. (note that this would happen even
|
|
* "read-only" pages. If the page gets tossed, we will get another exception
|
|
* and fix yet again).
|
|
*/
|
|
|
|
ENTRY_NP(_atomic_swap_32)
|
|
mov r2, r0
|
|
1:
|
|
#ifdef _ARM_ARCH_6
|
|
ldrex r0, [r2]
|
|
cmp r0, r1
|
|
strexne ip, r1, [r2]
|
|
#else
|
|
swp r0, r1, [r2]
|
|
cmp r0, r1
|
|
movsne ip, #0
|
|
#endif
|
|
cmpne ip, #0
|
|
bne 1b
|
|
#ifdef _ARM_ARCH_7
|
|
dmb
|
|
#else
|
|
mcr p15, 0, ip, c7, c10, 5 /* data memory barrier */
|
|
#endif
|
|
RET
|
|
END(_atomic_swap_32)
|
|
ATOMIC_OP_ALIAS(atomic_swap_32,_atomic_swap_32)
|
|
ATOMIC_OP_ALIAS(atomic_swap_uint,_atomic_swap_32)
|
|
ATOMIC_OP_ALIAS(atomic_swap_ulong,_atomic_swap_32)
|
|
ATOMIC_OP_ALIAS(atomic_swap_ptr,_atomic_swap_32)
|
|
STRONG_ALIAS(_atomic_swap_uint,_atomic_swap_32)
|
|
STRONG_ALIAS(_atomic_swap_ulong,_atomic_swap_32)
|
|
STRONG_ALIAS(_atomic_swap_ptr,_atomic_swap_32)
|
|
|
|
ENTRY_NP(_atomic_swap_8)
|
|
mov r2, r0
|
|
1:
|
|
#ifdef _ARM_ARCH_6
|
|
ldrexb r0, [r2]
|
|
strexb r3, r1, [r2]
|
|
#else
|
|
swpb r0, r1, [r2]
|
|
mov r3, #0
|
|
#endif
|
|
cmp r3, #0
|
|
bne 1b
|
|
#ifdef _ARM_ARCH_7
|
|
dmb
|
|
#else
|
|
mcr p15, 0, ip, c7, c10, 5 /* data memory barrier */
|
|
#endif
|
|
RET
|
|
END(_atomic_swap_8)
|
|
ATOMIC_OP_ALIAS(atomic_swap_8,_atomic_swap_8)
|
|
ATOMIC_OP_ALIAS(atomic_swap_char,_atomic_swap_8)
|
|
ATOMIC_OP_ALIAS(atomic_swap_uchar,_atomic_swap_8)
|
|
STRONG_ALIAS(_atomic_swap_char,_atomic_swap_8)
|
|
STRONG_ALIAS(_atomic_swap_uchar,_atomic_swap_8)
|