File: [cvs.NetBSD.org] / src / common / lib / libc / arch / sparc / atomic / membar_ops.S (download)
Revision 1.7, Sat Apr 9 22:53:17 2022 UTC (23 months, 2 weeks ago) by riastradh
Branch: MAIN
Changes since 1.6: +7 -7
lines
sparc/membar_ops: Upgrade membar_enter from R/RW to RW/RW.
This will be deprecated soon but let's avoid leaving rakes to trip on
with it arising from disagreement over the documentation (W/RW) and
implementation and usage (R/RW).
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/* $NetBSD: membar_ops.S,v 1.7 2022/04/09 22:53:17 riastradh Exp $ */
/*-
* Copyright (c) 2007 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Jason R. Thorpe, and by Andrew Doran.
*
* 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 _KERNEL_OPT
#include "opt_multiprocessor.h"
#endif
.text
/*
* These assume Total Store Order (TSO), which may reorder
* store-before-load but nothing else. Hence, only membar_sync (and
* its deprecated alias membar_enter) must issue anything --
* specifically, an LDSTUB, which (along with SWAP) is the only
* instruction that implies a sequential consistency barrier.
*
* If we ran with Partial Store Order (PSO), we would also need to
* issue STBAR for membar_exit (load/store-before-store) and
* membar_producer (store-before-store).
*/
ENTRY(_membar_consumer)
retl
nop
END(_membar_consumer)
ENTRY(_membar_sync)
retl
#if !defined(_KERNEL) || defined(MULTIPROCESSOR)
ldstub [%sp - 4], %g0
#else
nop
#endif
END(_membar_sync)
ATOMIC_OP_ALIAS(membar_producer,_membar_consumer)
STRONG_ALIAS(_membar_producer,_membar_consumer)
ATOMIC_OP_ALIAS(membar_consumer,_membar_consumer)
ATOMIC_OP_ALIAS(membar_enter,_membar_sync)
STRONG_ALIAS(_membar_enter,_membar_sync)
ATOMIC_OP_ALIAS(membar_exit,_membar_consumer)
STRONG_ALIAS(_membar_exit,_membar_consumer)
ATOMIC_OP_ALIAS(membar_sync,_membar_sync)