xref: /illumos-gate/usr/src/uts/intel/asm/thread.h (revision 20a7641f9918de8574b8b3b47dbe35c4bfc78df1)
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