1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2002 Daniel Eischen <deischen@freebsd.org>.
5 * Copyright (c) 2005 David Xu <davidxu@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. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
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 * $FreeBSD$
30 */
31
32/*
33 * Machine-dependent thread prototypes/definitions.
34 */
35#ifndef _PTHREAD_MD_H_
36#define	_PTHREAD_MD_H_
37
38#include <stddef.h>
39#include <sys/types.h>
40#include <machine/sysarch.h>
41
42#define	CPU_SPINWAIT		__asm __volatile("pause")
43
44#define	DTV_OFFSET		offsetof(struct tcb, tcb_dtv)
45
46/*
47 * Variant II tcb, first two members are required by rtld,
48 * %gs points to the structure.
49 */
50struct tcb {
51	struct tcb		*tcb_self;	/* required by rtld */
52	void			*tcb_dtv;	/* required by rtld */
53	struct pthread		*tcb_thread;
54};
55
56/*
57 * Evaluates to the byte offset of the per-tcb variable name.
58 */
59#define	__tcb_offset(name)	__offsetof(struct tcb, name)
60
61/*
62 * Evaluates to the type of the per-tcb variable name.
63 */
64#define	__tcb_type(name)	__typeof(((struct tcb *)0)->name)
65
66/*
67 * Evaluates to the value of the per-tcb variable name.
68 */
69#define	TCB_GET32(name) ({					\
70	__tcb_type(name) __result;				\
71								\
72	u_int __i;						\
73	__asm __volatile("movl %%gs:%1, %0"			\
74	    : "=r" (__i)					\
75	    : "m" (*(volatile u_int *)(__tcb_offset(name))));	\
76	__result = (__tcb_type(name))__i;			\
77								\
78	__result;						\
79})
80
81/* Called from the thread to set its private data. */
82static __inline void
83_tcb_set(struct tcb *tcb)
84{
85 	i386_set_gsbase(tcb);
86}
87
88/* Get the current kcb. */
89static __inline struct tcb *
90_tcb_get(void)
91{
92	return (TCB_GET32(tcb_self));
93}
94
95/* Get the current thread. */
96static __inline struct pthread *
97_get_curthread(void)
98{
99	return (TCB_GET32(tcb_thread));
100}
101
102#define HAS__UMTX_OP_ERR	1
103
104#endif
105