sysdeps/arm/nptl/tls.h

   1 /* Definition for thread-local data handling.  NPTL/ARM version.
   2    Copyright (C) 2005 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  1
  22
  23 #include <dl-sysdep.h>
  24
  25 #ifndef __ASSEMBLER__
  26 # include <stdbool.h>
  27 # include <stddef.h>
  28 # include <stdint.h>
  29
  30 /* Type for the dtv.  */
  31 typedef union dtv
  32 {
  33   size_t counter;
  34   struct
  35   {
  36     void *val;
  37     bool is_static;
  38   } pointer;
  39 } dtv_t;
  40
  41 #else /* __ASSEMBLER__ */
  42 # include <tcb-offsets.h>
  43 #endif /* __ASSEMBLER__ */
  44
  45
  46 /* We require TLS support in the tools.  */
  47 #ifndef HAVE_TLS_SUPPORT
  48 # error "TLS support is required."
  49 #endif
  50
  51 /* Signal that TLS support is available.  */
  52 # define USE_TLS        1
  53
  54 #ifndef __ASSEMBLER__
  55
  56 /* Get system call information.  */
  57 # include <sysdep.h>
  58
  59 /* The TP points to the start of the thread blocks.  */
  60 # define TLS_DTV_AT_TP  1
  61
  62 /* Get the thread descriptor definition.  */
  63 # include <nptl/descr.h>
  64
  65 typedef struct
  66 {
  67   dtv_t *dtv;
  68   void *private;
  69 } tcbhead_t;
  70
  71 /* This is the size of the initial TCB.  */
  72 # define TLS_INIT_TCB_SIZE      sizeof (tcbhead_t)
  73
  74 /* Alignment requirements for the initial TCB.  */
  75 # define TLS_INIT_TCB_ALIGN     16
  76
  77 /* This is the size of the TCB.  */
  78 # define TLS_TCB_SIZE           sizeof (tcbhead_t)
  79
  80 /* This is the size we need before TCB.  */
  81 # define TLS_PRE_TCB_SIZE       sizeof (struct pthread)
  82
  83 /* Alignment requirements for the TCB.  */
  84 # define TLS_TCB_ALIGN          16
  85
  86 /* Install the dtv pointer.  The pointer passed is to the element with
  87    index -1 which contain the length.  */
  88 # define INSTALL_DTV(tcbp, dtvp) \
  89   (((tcbhead_t *) (tcbp))->dtv = (dtvp) + 1)
  90
  91 /* Install new dtv for current thread.  */
  92 # define INSTALL_NEW_DTV(dtv) \
  93   (THREAD_DTV() = (dtv))
  94
  95 /* Return dtv of given thread descriptor.  */
  96 # define GET_DTV(tcbp) \
  97   (((tcbhead_t *) (tcbp))->dtv)
  98
  99 /* Code to initially initialize the thread pointer.  This might need
 100    special attention since 'errno' is not yet available and if the
 101    operation can cause a failure 'errno' must not be touched.  */
 102 # define TLS_INIT_TP(tcbp, secondcall) \
 103   ({ INTERNAL_SYSCALL_DECL (err);                                       \
 104      long result_var;                                                   \
 105      result_var = INTERNAL_SYSCALL_ARM (set_tls, err, 1, (tcbp));       \
 106      INTERNAL_SYSCALL_ERROR_P (result_var, err)                         \
 107        ? "unknown error" : NULL; })
 108
 109 /* Return the address of the dtv for the current thread.  */
 110 # define THREAD_DTV() \
 111   (((tcbhead_t *) __builtin_thread_pointer ())->dtv)
 112
 113 /* Return the thread descriptor for the current thread.  */
 114 # define THREAD_SELF \
 115  ((struct pthread *)__builtin_thread_pointer () - 1)
 116
 117 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 118 # define DB_THREAD_SELF \
 119   CONST_THREAD_AREA (32, sizeof (struct pthread))
 120
 121 /* Access to data in the thread descriptor is easy.  */
 122 #define THREAD_GETMEM(descr, member) \
 123   descr->member
 124 #define THREAD_GETMEM_NC(descr, member, idx) \
 125   descr->member[idx]
 126 #define THREAD_SETMEM(descr, member, value) \
 127   descr->member = (value)
 128 #define THREAD_SETMEM_NC(descr, member, idx, value) \
 129   descr->member[idx] = (value)
 130
 131 /* Initializing the thread pointer will generate a SIGILL if the syscall
 132    is not available.  */
 133 #define TLS_INIT_TP_EXPENSIVE 1
 134
 135 #endif /* __ASSEMBLER__ */
 136
 137 #endif  /* tls.h */