1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (C) 2003 David Xu <davidxu@freebsd.org>
5 * Copyright (c) 2001 Daniel Eischen <deischen@freebsd.org>
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Neither the name of the author nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#ifndef _MACHINE_TLS_H_
31#define	_MACHINE_TLS_H_
32
33#include <x86/sysarch.h>
34
35#define	TLS_VARIANT_II
36
37struct pthread;
38
39/*
40 * Variant II tcb, first two members are required by rtld,
41 * %fs (amd64) / %gs (i386) points to the structure.
42 */
43struct tcb {
44	struct tcb		*tcb_self;	/* required by rtld */
45	uintptr_t		*tcb_dtv;	/* required by rtld */
46	struct pthread		*tcb_thread;
47};
48
49#define	TLS_DTV_OFFSET	0
50#ifdef __amd64__
51#define	TLS_TCB_ALIGN	16
52#else
53#define	TLS_TCB_ALIGN	4
54#endif
55#define	TLS_TCB_SIZE	sizeof(struct tcb)
56#define	TLS_TP_OFFSET	0
57
58static __inline void
59_tcb_set(struct tcb *tcb)
60{
61#ifdef __amd64__
62	amd64_set_fsbase(tcb);
63#else
64 	i386_set_gsbase(tcb);
65#endif
66}
67
68static __inline struct tcb *
69_tcb_get(void)
70{
71	struct tcb *tcb;
72
73#ifdef __amd64__
74	__asm __volatile("movq %%fs:0, %0" : "=r" (tcb));
75#else
76	__asm __volatile("movl %%gs:0, %0" : "=r" (tcb));
77#endif
78	return (tcb);
79}
80
81#endif /* !_MACHINE_TLS_H_ */
82