lib/libthread_xu/arch/amd64/include/pthread_md.h

   1 /*-
   2  * Copyright (C) 2003 David Xu <davidxu@freebsd.org>
   3  * Copyright (c) 2001 Daniel Eischen <deischen@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. Neither the name of the author nor the names of its contributors
  12  *    may be used to endorse or promote products derived from this software
  13  *    without specific prior written permission.
  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: src/lib/libpthread/arch/amd64/include/pthread_md.h,v 1.10 2004/08/25 23:42:40 davidxu Exp $
  28  * $DragonFly: src/lib/libthread_xu/arch/amd64/include/pthread_md.h,v 1.3 2005/03/15 15:09:22 davidxu Exp $
  29  */
  30
  31 /*
  32  * Machine-dependent thread prototypes/definitions for the thread kernel.
  33  */
  34 #ifndef _PTHREAD_MD_H_
  35 #define _PTHREAD_MD_H_
  36
  37 #include <stddef.h>
  38 #include <sys/types.h>
  39 #include <machine/sysarch.h>
  40
  41 #define DTV_OFFSET              offsetof(struct tcb, tcb_dtv)
  42
  43 struct pthread;
  44
  45 /*
  46  * Variant II tcb, %fs points to the struct.
  47  */
  48
  49 struct tcb {
  50         struct tcb              *tcb_self;      /* required by rtld */
  51         void                    *tcb_dtv;       /* required by rtld */
  52         struct pthread          *tcb_thread;
  53         void                    *tcb_spare[1];  /* align tcb_tmbx to 16 bytes */
  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_GET64(name) ({                                      \
  70         __tcb_type(name) __result;                              \
  71                                                                 \
  72         u_long __i;                                             \
  73         __asm __volatile("movq %%fs:%1, %0"                     \
  74             : "=r" (__i)                                        \
  75             : "m" (*(u_long *)(__tcb_offset(name))));           \
  76         __result = (__tcb_type(name))__i;                       \
  77                                                                 \
  78         __result;                                               \
  79 })
  80
  81 /*
  82  * The constructors.
  83  */
  84 struct tcb      *_tcb_ctor(struct pthread *, int);
  85 void            _tcb_dtor(struct tcb *tcb);
  86
  87 /* Thread calls this function to set its private data. */
  88 static __inline void
  89 _tcb_set(struct tcb *tcb)
  90 {
  91         amd64_set_fsbase(tcb);
  92 }
  93
  94 /* Get the current kcb. */
  95 static __inline struct tcb *
  96 _tcb_get(void)
  97 {
  98         return (TCB_GET64(tcb_self));
  99 }
 100
 101 extern struct pthread *_thr_initial;
 102
 103 /* Get the current thread. */
 104 static __inline struct pthread *
 105 _get_curthread(void)
 106 {
 107         if (_thr_initial)
 108                 return (TCB_GET64(tcb_thread));
 109         return (NULL);
 110 }
 111 #endif