pthread_md.h revision 144518
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 144518 2005-04-02 01:20:00Z 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 DTV_OFFSET offsetof(struct tcb, tcb_dtv) 41 42/* 43 * Variant II tcb, first two members are required by rtld, 44 * %gs points to the structure. 45 */ 46struct tcb { 47 struct tcb *tcb_self; /* required by rtld */ 48 void *tcb_dtv; /* required by rtld */ 49 struct pthread *tcb_thread; 50 int tcb_ldt; 51}; 52 53/* 54 * Evaluates to the byte offset of the per-tcb variable name. 55 */ 56#define __tcb_offset(name) __offsetof(struct tcb, name) 57 58/* 59 * Evaluates to the type of the per-tcb variable name. 60 */ 61#define __tcb_type(name) __typeof(((struct tcb *)0)->name) 62 63/* 64 * Evaluates to the value of the per-tcb variable name. 65 */ 66#define TCB_GET32(name) ({ \ 67 __tcb_type(name) __result; \ 68 \ 69 u_int __i; \ 70 __asm __volatile("movl %%gs:%1, %0" \ 71 : "=r" (__i) \ 72 : "m" (*(u_int *)(__tcb_offset(name)))); \ 73 __result = (__tcb_type(name))__i; \ 74 \ 75 __result; \ 76}) 77 78/* 79 * The constructors. 80 */ 81struct tcb *_tcb_ctor(struct pthread *, int); 82void _tcb_dtor(struct tcb *tcb); 83 84/* Called from the thread to set its private data. */ 85static __inline void 86_tcb_set(struct tcb *tcb) 87{ 88#ifndef COMPAT_32BIT 89 int val; 90 91 val = (tcb->tcb_ldt << 3) | 7; 92 __asm __volatile("movl %0, %%gs" : : "r" (val)); 93#else 94 _amd64_set_gsbase(tcb); 95#endif 96 97} 98 99/* Get the current kcb. */ 100static __inline struct tcb * 101_tcb_get(void) 102{ 103 return (TCB_GET32(tcb_self)); 104} 105 106extern struct pthread *_thr_initial; 107 108/* Get the current thread. */ 109static __inline struct pthread * 110_get_curthread(void) 111{ 112 if (_thr_initial) 113 return (TCB_GET32(tcb_thread)); 114 return (NULL); 115} 116#endif 117