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, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26 
  27 #ifndef _ASM_THREAD_H
  28 #define _ASM_THREAD_H
  29 
  30 #include <sys/ccompile.h>
  31 #include <sys/types.h>
  32 
  33 #ifdef  __cplusplus
  34 extern "C" {
  35 #endif
  36 
  37 #if !defined(__lint) && defined(__GNUC__)
  38 
  39 struct _kthread;
  40 
  41 /*
  42  * 0x10 is offsetof(struct cpu, cpu_thread)
  43  * 0x18 is the same thing for the _LP64 version.
  44  * (It's also the value of CPU_THREAD in assym.h)
  45  * Yuck.
  46  */
  47 
  48 extern __GNU_INLINE struct _kthread
  49 *threadp(void)
  50 {
  51         void *__value;
  52 
  53 #if defined(__amd64)
  54         __asm__ __volatile__(
  55             "movq %%gs:0x18,%0"         /* CPU_THREAD */
  56             : "=r" (__value));
  57 #elif defined(__i386)
  58         __asm__ __volatile__(
  59             "movl %%gs:0x10,%0"         /* CPU_THREAD */
  60             : "=r" (__value));
  61 #else
  62 #error  "port me"
  63 #endif
  64         return (__value);
  65 }
  66 
  67 #endif  /* !__lint && __GNUC__ */
  68 
  69 #ifdef  __cplusplus
  70 }
  71 #endif
  72 
  73 #endif  /* _ASM_THREAD_H */