xref: /illumos-gate/usr/src/uts/intel/asm/thread.h (revision 300fdee27f8b59b381c1a0316bdee52fdfdb9213)
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   * Copyright 2014 Nexenta Systems, Inc.  All rights reserved.
26   */
27  
28  #ifndef _ASM_THREAD_H
29  #define	_ASM_THREAD_H
30  
31  #include <sys/ccompile.h>
32  #include <sys/types.h>
33  
34  #ifdef	__cplusplus
35  extern "C" {
36  #endif
37  
38  #if !defined(__lint) && defined(__GNUC__)
39  
40  struct _kthread;
41  
42  /*
43   * 0x10 is offsetof(struct cpu, cpu_thread)
44   * 0x18 is the same thing for the _LP64 version.
45   * (It's also the value of CPU_THREAD in assym.h)
46   * Yuck.
47   */
48  
49  extern __GNU_INLINE struct _kthread
50  *threadp(void)
51  {
52  	struct _kthread *__value;
53  
54  #if defined(__amd64)
55  	__asm__ __volatile__(
56  	    "movq %%gs:0x18,%0"		/* CPU_THREAD */
57  	    : "=r" (__value));
58  #elif defined(__i386)
59  	__asm__ __volatile__(
60  	    "movl %%gs:0x10,%0"		/* CPU_THREAD */
61  	    : "=r" (__value));
62  #else
63  #error	"port me"
64  #endif
65  	return (__value);
66  }
67  
68  #endif	/* !__lint && __GNUC__ */
69  
70  #ifdef	__cplusplus
71  }
72  #endif
73  
74  #endif	/* _ASM_THREAD_H */
75