usr/src/lib/libc/amd64/sys/_lwp_mutex_unlock.s

   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
  43 1:
  44         RETC
  45         SET_SIZE(_lwp_mutex_unlock)