xref: /illumos-gate/usr/src/uts/intel/asm/thread.h (revision 1ed6b69a5ca1ca3ee5e9a4931f74e2237c7e1c9f)
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 */
74