sysdeps/arm/nptl/tls.h

   1 /* Definition for thread-local data handling.  NPTL/ARM version.
   2    Copyright (C) 2005-2014 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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _TLS_H
  20 #define _TLS_H  1
  21
  22 #include <dl-sysdep.h>
  23
  24 #ifndef __ASSEMBLER__
  25 # include <stdbool.h>
  26 # include <stddef.h>
  27 # include <stdint.h>
  28
  29 /* Type for the dtv.  */
  30 typedef union dtv
  31 {
  32   size_t counter;
  33   struct
  34   {
  35     void *val;
  36     bool is_static;
  37   } pointer;
  38 } dtv_t;
  39
  40 #else /* __ASSEMBLER__ */
  41 # include <tcb-offsets.h>
  42 #endif /* __ASSEMBLER__ */
  43
  44
  45 #ifndef __ASSEMBLER__
  46
  47 /* Get system call information.  */
  48 # include <sysdep.h>
  49
  50 /* The TP points to the start of the thread blocks.  */
  51 # define TLS_DTV_AT_TP  1
  52 # define TLS_TCB_AT_TP  0
  53
  54 /* Get the thread descriptor definition.  */
  55 # include <nptl/descr.h>
  56
  57 typedef struct
  58 {
  59   dtv_t *dtv;
  60   void *private;
  61 } tcbhead_t;
  62
  63 /* This is the size of the initial TCB.  */
  64 # define TLS_INIT_TCB_SIZE      sizeof (tcbhead_t)
  65
  66 /* Alignment requirements for the initial TCB.  */
  67 # define TLS_INIT_TCB_ALIGN     16
  68
  69 /* This is the size of the TCB.  */
  70 # define TLS_TCB_SIZE           sizeof (tcbhead_t)
  71
  72 /* This is the size we need before TCB.  */
  73 # define TLS_PRE_TCB_SIZE       sizeof (struct pthread)
  74
  75 /* Alignment requirements for the TCB.  */
  76 # define TLS_TCB_ALIGN          16
  77
  78 /* Install the dtv pointer.  The pointer passed is to the element with
  79    index -1 which contain the length.  */
  80 # define INSTALL_DTV(tcbp, dtvp) \
  81   (((tcbhead_t *) (tcbp))->dtv = (dtvp) + 1)
  82
  83 /* Install new dtv for current thread.  */
  84 # define INSTALL_NEW_DTV(dtv) \
  85   (THREAD_DTV() = (dtv))
  86
  87 /* Return dtv of given thread descriptor.  */
  88 # define GET_DTV(tcbp) \
  89   (((tcbhead_t *) (tcbp))->dtv)
  90
  91 /* Code to initially initialize the thread pointer.  This might need
  92    special attention since 'errno' is not yet available and if the
  93    operation can cause a failure 'errno' must not be touched.  */
  94 # define TLS_INIT_TP(tcbp) \
  95   ({ INTERNAL_SYSCALL_DECL (err);                                       \
  96      long result_var;                                                   \
  97      result_var = INTERNAL_SYSCALL_ARM (set_tls, err, 1, (tcbp));       \
  98      INTERNAL_SYSCALL_ERROR_P (result_var, err)                         \
  99        ? "unknown error" : NULL; })
 100
 101 /* Return the address of the dtv for the current thread.  */
 102 # define THREAD_DTV() \
 103   (((tcbhead_t *) __builtin_thread_pointer ())->dtv)
 104
 105 /* Return the thread descriptor for the current thread.  */
 106 # define THREAD_SELF \
 107  ((struct pthread *)__builtin_thread_pointer () - 1)
 108
 109 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 110 # define DB_THREAD_SELF \
 111   CONST_THREAD_AREA (32, sizeof (struct pthread))
 112
 113 /* Access to data in the thread descriptor is easy.  */
 114 #define THREAD_GETMEM(descr, member) \
 115   descr->member
 116 #define THREAD_GETMEM_NC(descr, member, idx) \
 117   descr->member[idx]
 118 #define THREAD_SETMEM(descr, member, value) \
 119   descr->member = (value)
 120 #define THREAD_SETMEM_NC(descr, member, idx, value) \
 121   descr->member[idx] = (value)
 122
 123 /* Get and set the global scope generation counter in struct pthread.  */
 124 #define THREAD_GSCOPE_FLAG_UNUSED 0
 125 #define THREAD_GSCOPE_FLAG_USED   1
 126 #define THREAD_GSCOPE_FLAG_WAIT   2
 127 #define THREAD_GSCOPE_RESET_FLAG() \
 128   do                                                                         \
 129     { int __res                                                              \
 130         = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,             \
 131                                THREAD_GSCOPE_FLAG_UNUSED);                   \
 132       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                  \
 133         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);   \
 134     }                                                                        \
 135   while (0)
 136 #define THREAD_GSCOPE_SET_FLAG() \
 137   do                                                                         \
 138     {                                                                        \
 139       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;             \
 140       atomic_write_barrier ();                                               \
 141     }                                                                        \
 142   while (0)
 143 #define THREAD_GSCOPE_WAIT() \
 144   GL(dl_wait_lookup_done) ()
 145
 146 #endif /* __ASSEMBLER__ */
 147
 148 #endif  /* tls.h */