smt_pause.s revision ac823a0f31ed9c8cbe505cee2def262ac92ea6cd
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
*/
.file "smt_pause.s"
/*
* void smt_pause(void)
*
* Do nothing efficiently.
*
*/
#include <sys/asm_linkage.h>
#include <sys/niagaraasi.h>
#include <sys/asi.h>
#include <sys/stack.h>
#if defined(NIAGARA_IMPL)
#include <assym.h>
#endif
ENTRY(smt_pause)
#if defined(NIAGARA2_IMPL) || defined(VFALLS_IMPL) || defined(KT_IMPL)
rd %ccr, %g0
rd %ccr, %g0
retl
rd %ccr, %g0
#else /* NIAGARA2_IMPL */
#define BANKS (4 * 64) /* 4 cachelines, cover all banks */
save %sp, -SA(MINFRAME+BANKS), %sp
ld [%g7 + UL_LWPID], %i3 ! curthread->ul_lwpid
add %fp, STACK_BIAS-BANKS, %i0
and %i3, 0x3, %i2 ! save last 2 bits
sllx %i2, 0x6, %i1 ! pick a slot
add %i1, %i0, %o0
casx [%o0], %g0, %g0
casx [%o0], %g0, %g0
casx [%o0], %g0, %g0
ret
restore
#endif /* NIAGARA2_IMPL */
SET_SIZE(smt_pause)