pthread_md.h revision 165241 
1/*-
2 * Copyright (c) 2002 Daniel Eischen <deischen@freebsd.org>.
3 * Copyright (c) 2005 David Xu <davidxu@freebsd.org>.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 * $FreeBSD: head/lib/libthr/arch/i386/include/pthread_md.h 165241 2006-12-15 11:52:01Z davidxu $
28 */
29
30/*
31 * Machine-dependent thread prototypes/definitions.
32 */
33#ifndef _PTHREAD_MD_H_
34#define	_PTHREAD_MD_H_
35
36#include <stddef.h>
37#include <sys/types.h>
38#include <machine/sysarch.h>
39
40#define	CPU_SPINWAIT		__asm __volatile("pause")
41
42#define	DTV_OFFSET		offsetof(struct tcb, tcb_dtv)
43
44/*
45 * Variant II tcb, first two members are required by rtld,
46 * %gs points to the structure.
47 */
48struct tcb {
49	struct tcb		*tcb_self;	/* required by rtld */
50	void			*tcb_dtv;	/* required by rtld */
51	struct pthread		*tcb_thread;
52};
53
54/*
55 * Evaluates to the byte offset of the per-tcb variable name.
56 */
57#define	__tcb_offset(name)	__offsetof(struct tcb, name)
58
59/*
60 * Evaluates to the type of the per-tcb variable name.
61 */
62#define	__tcb_type(name)	__typeof(((struct tcb *)0)->name)
63
64/*
65 * Evaluates to the value of the per-tcb variable name.
66 */
67#define	TCB_GET32(name) ({					\
68	__tcb_type(name) __result;				\
69								\
70	u_int __i;						\
71	__asm __volatile("movl %%gs:%1, %0"			\
72	    : "=r" (__i)					\
73	    : "m" (*(u_int *)(__tcb_offset(name))));		\
74	__result = (__tcb_type(name))__i;			\
75								\
76	__result;						\
77})
78
79/*
80 * The constructors.
81 */
82struct tcb	*_tcb_ctor(struct pthread *, int);
83void		_tcb_dtor(struct tcb *tcb);
84
85/* Called from the thread to set its private data. */
86static __inline void
87_tcb_set(struct tcb *tcb)
88{
89 	i386_set_gsbase(tcb);
90}
91
92/* Get the current kcb. */
93static __inline struct tcb *
94_tcb_get(void)
95{
96	return (TCB_GET32(tcb_self));
97}
98
99/* Get the current thread. */
100static __inline struct pthread *
101_get_curthread(void)
102{
103	return (TCB_GET32(tcb_thread));
104}
105#endif
106