xref: /titanic_44/usr/src/lib/libc/amd64/sys/_lwp_mutex_unlock.s (revision 9a70fc3be3b1e966bf78825cdb8d509963a6f0a1)
1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22/*
23 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26
27	.file	"_lwp_mutex_unlock.s"
28
29#include "SYS.h"
30#include <../assym.h>
31
32	ENTRY(_lwp_mutex_unlock)
33	movq	%rdi, %rax
34	addq	$MUTEX_LOCK_WORD, %rax
35	xorl	%ecx, %ecx
36	xchgl	(%rax), %ecx	/* clear lock and get old lock into %ecx */
37	andl	$WAITER_MASK, %ecx	/* was anyone waiting on it? */
38	je	1f
39	xorl	%esi, %esi
40	SYSTRAP_RVAL1(lwp_mutex_wakeup)	/* lwp_mutex_wakeup(mp, 0) */
41	SYSLWPERR
42	RET
431:
44	RETC
45	SET_SIZE(_lwp_mutex_unlock)
46