sysdeps/aarch64/nptl/tls.h

   1 /* Copyright (C) 2005-2020 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
  30 #else /* __ASSEMBLER__ */
  31 # include <tcb-offsets.h>
  32 #endif /* __ASSEMBLER__ */
  33
  34 #ifndef __ASSEMBLER__
  35
  36 /* Get system call information.  */
  37 # include <sysdep.h>
  38
  39 /* The TP points to the start of the thread blocks.  */
  40 # define TLS_DTV_AT_TP  1
  41 # define TLS_TCB_AT_TP  0
  42
  43 /* Get the thread descriptor definition.  */
  44 # include <nptl/descr.h>
  45
  46 typedef struct
  47 {
  48   dtv_t *dtv;
  49   void *private;
  50 } tcbhead_t;
  51
  52 /* This is the size of the initial TCB.  */
  53 # define TLS_INIT_TCB_SIZE      sizeof (tcbhead_t)
  54
  55 /* Alignment requirements for the initial TCB.  */
  56 # define TLS_INIT_TCB_ALIGN     __alignof__ (struct pthread)
  57
  58 /* This is the size of the TCB.  */
  59 # define TLS_TCB_SIZE           sizeof (tcbhead_t)
  60
  61 /* This is the size we need before TCB.  */
  62 # define TLS_PRE_TCB_SIZE       sizeof (struct pthread)
  63
  64 /* Alignment requirements for the TCB.  */
  65 # define TLS_TCB_ALIGN          __alignof__ (struct pthread)
  66
  67 /* Install the dtv pointer.  The pointer passed is to the element with
  68    index -1 which contain the length.  */
  69 # define INSTALL_DTV(tcbp, dtvp) \
  70   (((tcbhead_t *) (tcbp))->dtv = (dtvp) + 1)
  71
  72 /* Install new dtv for current thread.  */
  73 # define INSTALL_NEW_DTV(dtv) \
  74   (THREAD_DTV() = (dtv))
  75
  76 /* Return dtv of given thread descriptor.  */
  77 # define GET_DTV(tcbp) \
  78   (((tcbhead_t *) (tcbp))->dtv)
  79
  80 /* Code to initially initialize the thread pointer.  This might need
  81    special attention since 'errno' is not yet available and if the
  82    operation can cause a failure 'errno' must not be touched.  */
  83 # define TLS_INIT_TP(tcbp) \
  84   ({ __asm __volatile ("msr tpidr_el0, %0" : : "r" (tcbp)); NULL; })
  85
  86 /* Value passed to 'clone' for initialization of the thread register.  */
  87 # define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd) + 1
  88
  89 /* Return the address of the dtv for the current thread.  */
  90 # define THREAD_DTV() \
  91   (((tcbhead_t *) __builtin_thread_pointer ())->dtv)
  92
  93 /* Return the thread descriptor for the current thread.  */
  94 # define THREAD_SELF \
  95  ((struct pthread *)__builtin_thread_pointer () - 1)
  96
  97 /* Magic for libthread_db to know how to do THREAD_SELF.  */
  98 # define DB_THREAD_SELF \
  99   CONST_THREAD_AREA (64, sizeof (struct pthread))
 100
 101 /* Access to data in the thread descriptor is easy.  */
 102 # define THREAD_GETMEM(descr, member) \
 103   descr->member
 104 # define THREAD_GETMEM_NC(descr, member, idx) \
 105   descr->member[idx]
 106 # define THREAD_SETMEM(descr, member, value) \
 107   descr->member = (value)
 108 # define THREAD_SETMEM_NC(descr, member, idx, value) \
 109   descr->member[idx] = (value)
 110
 111 /* Get and set the global scope generation counter in struct pthread.  */
 112 # define THREAD_GSCOPE_IN_TCB      1
 113 # define THREAD_GSCOPE_FLAG_UNUSED 0
 114 # define THREAD_GSCOPE_FLAG_USED   1
 115 # define THREAD_GSCOPE_FLAG_WAIT   2
 116 # define THREAD_GSCOPE_RESET_FLAG() \
 117   do                                                                         \
 118     { int __res                                                              \
 119         = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,             \
 120                                THREAD_GSCOPE_FLAG_UNUSED);                   \
 121       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                  \
 122         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);   \
 123     }                                                                        \
 124   while (0)
 125 # define THREAD_GSCOPE_SET_FLAG() \
 126   do                                                                         \
 127     {                                                                        \
 128       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;             \
 129       atomic_write_barrier ();                                               \
 130     }                                                                        \
 131   while (0)
 132
 133 # endif /* __ASSEMBLER__ */
 134
 135 #endif  /* tls.h */