xref: /titanic_51/usr/src/lib/libc/amd64/gen/lock.s (revision 1e49577a7fcde812700ded04431b49d67cc57d6d)
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 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
23 * Use is subject to license terms.
24 */
25
26	.file	"lock.s"
27
28#include "SYS.h"
29
30/
31/ _lock_try(lp)
32/	- returns non-zero on success.
33/
34	ENTRY(_lock_try)
35	movl	$1,%eax
36	xchgb	%al, (%rdi)
37	xorb	$1, %al
38	ret
39	SET_SIZE(_lock_try)
40
41/
42/ _lock_clear(lp)
43/	- clear lock and force it to appear unlocked in memory.
44/
45	ENTRY(_lock_clear)
46	movb	$0, (%rdi)
47	ret
48	SET_SIZE(_lock_clear)
49