sysdeps/aarch64/nptl/tls.h

   1 /* Copyright (C) 2005-2023 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    <https://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 # include <dl-dtv.h>
  29 #endif /* __ASSEMBLER__ */
  30
  31 #ifndef __ASSEMBLER__
  32
  33 /* Get system call information.  */
  34 # include <sysdep.h>
  35
  36 /* The TP points to the start of the thread blocks.  */
  37 # define TLS_DTV_AT_TP  1
  38 # define TLS_TCB_AT_TP  0
  39
  40 /* Get the thread descriptor definition.  */
  41 # include <nptl/descr.h>
  42
  43 typedef struct
  44 {
  45   dtv_t *dtv;
  46   void *private;
  47 } tcbhead_t;
  48
  49 /* This is the size of the initial TCB.  */
  50 # define TLS_INIT_TCB_SIZE      sizeof (tcbhead_t)
  51
  52 /* This is the size of the TCB.  */
  53 # define TLS_TCB_SIZE           sizeof (tcbhead_t)
  54
  55 /* This is the size we need before TCB.  */
  56 # define TLS_PRE_TCB_SIZE       sizeof (struct pthread)
  57
  58 /* Install the dtv pointer.  The pointer passed is to the element with
  59    index -1 which contain the length.  */
  60 # define INSTALL_DTV(tcbp, dtvp) \
  61   (((tcbhead_t *) (tcbp))->dtv = (dtvp) + 1)
  62
  63 /* Install new dtv for current thread.  */
  64 # define INSTALL_NEW_DTV(dtv) \
  65   (THREAD_DTV() = (dtv))
  66
  67 /* Return dtv of given thread descriptor.  */
  68 # define GET_DTV(tcbp) \
  69   (((tcbhead_t *) (tcbp))->dtv)
  70
  71 /* Code to initially initialize the thread pointer.  This might need
  72    special attention since 'errno' is not yet available and if the
  73    operation can cause a failure 'errno' must not be touched.  */
  74 # define TLS_INIT_TP(tcbp) \
  75   ({ __asm __volatile ("msr tpidr_el0, %0" : : "r" (tcbp)); true; })
  76
  77 /* Value passed to 'clone' for initialization of the thread register.  */
  78 # define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd) + 1
  79
  80 /* Return the address of the dtv for the current thread.  */
  81 # define THREAD_DTV() \
  82   (((tcbhead_t *) __builtin_thread_pointer ())->dtv)
  83
  84 /* Return the thread descriptor for the current thread.  */
  85 # define THREAD_SELF \
  86  ((struct pthread *)__builtin_thread_pointer () - 1)
  87
  88 /* Magic for libthread_db to know how to do THREAD_SELF.  */
  89 # define DB_THREAD_SELF \
  90   CONST_THREAD_AREA (64, sizeof (struct pthread))
  91
  92 # include <tcb-access.h>
  93
  94 /* Get and set the global scope generation counter in struct pthread.  */
  95 # define THREAD_GSCOPE_FLAG_UNUSED 0
  96 # define THREAD_GSCOPE_FLAG_USED   1
  97 # define THREAD_GSCOPE_FLAG_WAIT   2
  98 # define THREAD_GSCOPE_RESET_FLAG() \
  99   do                                                                         \
 100     { int __res                                                              \
 101         = atomic_exchange_release (&THREAD_SELF->header.gscope_flag,         \
 102                                THREAD_GSCOPE_FLAG_UNUSED);                   \
 103       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                  \
 104         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);   \
 105     }                                                                        \
 106   while (0)
 107 # define THREAD_GSCOPE_SET_FLAG() \
 108   do                                                                         \
 109     {                                                                        \
 110       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;             \
 111       atomic_write_barrier ();                                               \
 112     }                                                                        \
 113   while (0)
 114
 115 # endif /* __ASSEMBLER__ */
 116
 117 #endif  /* tls.h */