ports/sysdeps/aarch64/nptl/tls.h

   1 /* Copyright (C) 2005-2014 Free Software Foundation, Inc.
   2
   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 License as
   7    published by the Free Software Foundation; either version 2.1 of the
   8    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 #ifndef __ASSEMBLER__
  45
  46 /* Get system call information.  */
  47 # include <sysdep.h>
  48
  49 /* The TP points to the start of the thread blocks.  */
  50 # define TLS_DTV_AT_TP  1
  51
  52 /* Get the thread descriptor definition.  */
  53 # include <nptl/descr.h>
  54
  55 typedef struct
  56 {
  57   dtv_t *dtv;
  58   void *private;
  59 } tcbhead_t;
  60
  61 /* This is the size of the initial TCB.  */
  62 # define TLS_INIT_TCB_SIZE      sizeof (tcbhead_t)
  63
  64 /* Alignment requirements for the initial TCB.  */
  65 # define TLS_INIT_TCB_ALIGN     __alignof__ (tcbhead_t)
  66
  67 /* This is the size of the TCB.  */
  68 # define TLS_TCB_SIZE           sizeof (tcbhead_t)
  69
  70 /* This is the size we need before TCB.  */
  71 # define TLS_PRE_TCB_SIZE       sizeof (struct pthread)
  72
  73 /* Alignment requirements for the TCB.  */
  74 # define TLS_TCB_ALIGN          __alignof__ (tcbhead_t)
  75
  76 /* Install the dtv pointer.  The pointer passed is to the element with
  77    index -1 which contain the length.  */
  78 # define INSTALL_DTV(tcbp, dtvp) \
  79   (((tcbhead_t *) (tcbp))->dtv = (dtvp) + 1)
  80
  81 /* Install new dtv for current thread.  */
  82 # define INSTALL_NEW_DTV(dtv) \
  83   (THREAD_DTV() = (dtv))
  84
  85 /* Return dtv of given thread descriptor.  */
  86 # define GET_DTV(tcbp) \
  87   (((tcbhead_t *) (tcbp))->dtv)
  88
  89 /* Code to initially initialize the thread pointer.  This might need
  90    special attention since 'errno' is not yet available and if the
  91    operation can cause a failure 'errno' must not be touched.  */
  92 # define TLS_INIT_TP(tcbp, secondcall) \
  93   ({ __asm __volatile ("msr tpidr_el0, %0" : : "r" (tcbp)); NULL; })
  94
  95 /* Return the address of the dtv for the current thread.  */
  96 # define THREAD_DTV() \
  97   (((tcbhead_t *) __builtin_thread_pointer ())->dtv)
  98
  99 /* Return the thread descriptor for the current thread.  */
 100 # define THREAD_SELF \
 101  ((struct pthread *)__builtin_thread_pointer () - 1)
 102
 103 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 104 # define DB_THREAD_SELF \
 105   CONST_THREAD_AREA (64, sizeof (struct pthread))
 106
 107 /* Access to data in the thread descriptor is easy.  */
 108 # define THREAD_GETMEM(descr, member) \
 109   descr->member
 110 # define THREAD_GETMEM_NC(descr, member, idx) \
 111   descr->member[idx]
 112 # define THREAD_SETMEM(descr, member, value) \
 113   descr->member = (value)
 114 # define THREAD_SETMEM_NC(descr, member, idx, value) \
 115   descr->member[idx] = (value)
 116
 117 /* Get and set the global scope generation counter in struct pthread.  */
 118 # define THREAD_GSCOPE_FLAG_UNUSED 0
 119 # define THREAD_GSCOPE_FLAG_USED   1
 120 # define THREAD_GSCOPE_FLAG_WAIT   2
 121 # define THREAD_GSCOPE_RESET_FLAG() \
 122   do                                                                         \
 123     { int __res                                                              \
 124         = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,             \
 125                                THREAD_GSCOPE_FLAG_UNUSED);                   \
 126       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                  \
 127         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);   \
 128     }                                                                        \
 129   while (0)
 130 # define THREAD_GSCOPE_SET_FLAG() \
 131   do                                                                         \
 132     {                                                                        \
 133       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;             \
 134       atomic_write_barrier ();                                               \
 135     }                                                                        \
 136   while (0)
 137 # define THREAD_GSCOPE_WAIT() \
 138   GL(dl_wait_lookup_done) ()
 139
 140 # endif /* __ASSEMBLER__ */
 141
 142 #endif  /* tls.h */