ports/sysdeps/arm/nptl/tls.h

   1 /* Definition for thread-local data handling.  NPTL/ARM version.
   2    Copyright (C) 2005, 2007, 2011 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
  53 /* Get the thread descriptor definition.  */
  54 # include <nptl/descr.h>
  55
  56 typedef struct
  57 {
  58   dtv_t *dtv;
  59   void *private;
  60 } tcbhead_t;
  61
  62 /* This is the size of the initial TCB.  */
  63 # define TLS_INIT_TCB_SIZE      sizeof (tcbhead_t)
  64
  65 /* Alignment requirements for the initial TCB.  */
  66 # define TLS_INIT_TCB_ALIGN     16
  67
  68 /* This is the size of the TCB.  */
  69 # define TLS_TCB_SIZE           sizeof (tcbhead_t)
  70
  71 /* This is the size we need before TCB.  */
  72 # define TLS_PRE_TCB_SIZE       sizeof (struct pthread)
  73
  74 /* Alignment requirements for the TCB.  */
  75 # define TLS_TCB_ALIGN          16
  76
  77 /* Install the dtv pointer.  The pointer passed is to the element with
  78    index -1 which contain the length.  */
  79 # define INSTALL_DTV(tcbp, dtvp) \
  80   (((tcbhead_t *) (tcbp))->dtv = (dtvp) + 1)
  81
  82 /* Install new dtv for current thread.  */
  83 # define INSTALL_NEW_DTV(dtv) \
  84   (THREAD_DTV() = (dtv))
  85
  86 /* Return dtv of given thread descriptor.  */
  87 # define GET_DTV(tcbp) \
  88   (((tcbhead_t *) (tcbp))->dtv)
  89
  90 /* Code to initially initialize the thread pointer.  This might need
  91    special attention since 'errno' is not yet available and if the
  92    operation can cause a failure 'errno' must not be touched.  */
  93 # define TLS_INIT_TP(tcbp, secondcall) \
  94   ({ INTERNAL_SYSCALL_DECL (err);                                       \
  95      long result_var;                                                   \
  96      result_var = INTERNAL_SYSCALL_ARM (set_tls, err, 1, (tcbp));       \
  97      INTERNAL_SYSCALL_ERROR_P (result_var, err)                         \
  98        ? "unknown error" : NULL; })
  99
 100 /* Return the address of the dtv for the current thread.  */
 101 # define THREAD_DTV() \
 102   (((tcbhead_t *) __builtin_thread_pointer ())->dtv)
 103
 104 /* Return the thread descriptor for the current thread.  */
 105 # define THREAD_SELF \
 106  ((struct pthread *)__builtin_thread_pointer () - 1)
 107
 108 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 109 # define DB_THREAD_SELF \
 110   CONST_THREAD_AREA (32, sizeof (struct pthread))
 111
 112 /* Access to data in the thread descriptor is easy.  */
 113 #define THREAD_GETMEM(descr, member) \
 114   descr->member
 115 #define THREAD_GETMEM_NC(descr, member, idx) \
 116   descr->member[idx]
 117 #define THREAD_SETMEM(descr, member, value) \
 118   descr->member = (value)
 119 #define THREAD_SETMEM_NC(descr, member, idx, value) \
 120   descr->member[idx] = (value)
 121
 122 /* Initializing the thread pointer will generate a SIGILL if the syscall
 123    is not available.  */
 124 #define TLS_INIT_TP_EXPENSIVE 1
 125
 126 /* Get and set the global scope generation counter in struct pthread.  */
 127 #define THREAD_GSCOPE_FLAG_UNUSED 0
 128 #define THREAD_GSCOPE_FLAG_USED   1
 129 #define THREAD_GSCOPE_FLAG_WAIT   2
 130 #define THREAD_GSCOPE_RESET_FLAG() \
 131   do                                                                         \
 132     { int __res                                                              \
 133         = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,             \
 134                                THREAD_GSCOPE_FLAG_UNUSED);                   \
 135       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                  \
 136         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);   \
 137     }                                                                        \
 138   while (0)
 139 #define THREAD_GSCOPE_SET_FLAG() \
 140   do                                                                         \
 141     {                                                                        \
 142       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;             \
 143       atomic_write_barrier ();                                               \
 144     }                                                                        \
 145   while (0)
 146 #define THREAD_GSCOPE_WAIT() \
 147   GL(dl_wait_lookup_done) ()
 148
 149 #endif /* __ASSEMBLER__ */
 150
 151 #endif  /* tls.h */