linuxthreads/sysdeps/sh/tls.h

   1 /* Definition for thread-local data handling.  linuxthreads/SH version.
   2    Copyright (C) 2002 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #ifndef _TLS_H
  21 #define _TLS_H
  22
  23 #ifndef __ASSEMBLER__
  24 #include <stddef.h>
  25
  26 #include <pt-machine.h>
  27
  28 /* Type for the dtv.  */
  29 typedef union dtv
  30 {
  31   size_t counter;
  32   void *pointer;
  33 } dtv_t;
  34
  35
  36 typedef struct
  37 {
  38   void *tcb;            /* Pointer to the TCB.  Not necessary the
  39                            thread descriptor used by libpthread.  */
  40   dtv_t *dtv;
  41   void *self;           /* Pointer to the thread descriptor.  */
  42 } tcbhead_t;
  43
  44
  45 /* We can support TLS only if the floating-stack support is available.  */
  46 #if defined FLOATING_STACKS && defined HAVE_TLS_SUPPORT
  47
  48 /* Get system call information.  */
  49 # include <sysdep.h>
  50
  51 /* Signal that TLS support is available.  */
  52 # define USE_TLS        1
  53
  54
  55 /* Get the thread descriptor definition.  */
  56 # include <linuxthreads/descr.h>
  57
  58 /* This is the size of the initial TCB.  */
  59 # define TLS_INIT_TCB_SIZE sizeof (tcbhead_t)
  60
  61 /* Alignment requirements for the initial TCB.  */
  62 # define TLS_INIT_TCB_ALIGN __alignof__ (tcbhead_t)
  63
  64 /* This is the size of the TCB.  */
  65 # define TLS_TCB_SIZE sizeof (struct _pthread_descr_struct)
  66
  67 /* Alignment requirements for the TCB.  */
  68 # define TLS_TCB_ALIGN __alignof__ (struct _pthread_descr_struct)
  69
  70 /* The TLS blocks start right after the TCB.  */
  71 # define TLS_DTV_AT_TP  1
  72
  73
  74 /* Install the dtv pointer.  The pointer passed is to the element with
  75    index -1 which contain the length.  */
  76 # define INSTALL_DTV(descr, dtvp) \
  77   ((tcbhead_t *) (descr))->dtv = dtvp + 1
  78
  79 /* Install new dtv for current thread.  */
  80 # define INSTALL_NEW_DTV(dtv) \
  81   ({ struct _pthread_descr_struct *__descr;                                   \
  82      THREAD_SETMEM (__descr, p_header.data.dtvp, (dtv)); })
  83
  84 /* Return dtv of given thread descriptor.  */
  85 # define GET_DTV(descr) \
  86   (((tcbhead_t *) (descr))->dtv)
  87
  88 /* Code to initially initialize the thread pointer.  This might need
  89    special attention since 'errno' is not yet available and if the
  90    operation can cause a failure 'errno' must not be touched.  */
  91 # define TLS_INIT_TP(descr, secondcall) \
  92   ({                                                                          \
  93     void *_descr = (descr);                                                   \
  94     int result;                                                               \
  95     tcbhead_t *head = _descr;                                                 \
  96                                                                               \
  97     head->tcb = _descr;                                                       \
  98     /* For now the thread descriptor is at the same address.  */              \
  99     head->self = _descr;                                                      \
 100                                                                               \
 101     asm ("ldc %0,gbr" : : "r" (_descr));                                      \
 102                                                                               \
 103     0;                                                                        \
 104   })
 105
 106
 107 /* Return the address of the dtv for the current thread.  */
 108 # define THREAD_DTV() \
 109   ({ struct _pthread_descr_struct *__descr;                                   \
 110      THREAD_GETMEM (__descr, p_header.data.dtvp); })
 111
 112 #endif  /* FLOATING_STACKS && HAVE_TLS_SUPPORT */
 113 #endif /* __ASSEMBLER__ */
 114
 115 #endif  /* tls.h */