sysdeps/csky/nptl/tls.h

   1 /* Definitions for thread-local data handling.  NPTL/C-SKY version.
   2    Copyright (C) 2018-2021 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    <https://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _TLS_H
  20 #define _TLS_H 1
  21
  22 #ifndef __ASSEMBLER__
  23
  24 # include <stdbool.h>
  25 # include <stddef.h>
  26 # include <stdint.h>
  27 # include <dl-dtv.h>
  28
  29 /* Define r31 as thread pointer register.  */
  30 # define READ_THREAD_POINTER() \
  31   ({ void *__result;                                            \
  32      __asm__ __volatile__ ("mov %0, r31"                        \
  33                            : "=r" (__result));                  \
  34      __result; })
  35
  36 #else
  37 # include <tcb-offsets.h>
  38 /* Define r31 as thread pointer register.  */
  39 # define READ_THREAD_POINTER() \
  40         mov r0, r31;
  41 #endif /* __ASSEMBLER__ */
  42
  43 #ifndef __ASSEMBLER__
  44
  45 /* Get system call information.  */
  46 # include <sysdep.h>
  47
  48 /* The TP points to the start of the thread blocks.  */
  49 # define TLS_DTV_AT_TP  1
  50 # define TLS_TCB_AT_TP  0
  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 /* This is the size of the TCB.  */
  65 # define TLS_TCB_SIZE           sizeof (tcbhead_t)
  66
  67 /* This is the size we need before TCB.  */
  68 # define TLS_PRE_TCB_SIZE       sizeof (struct pthread)
  69
  70 /* The thread pointer tp points to the end of the TCB.
  71    The pthread_descr structure is immediately in front of the TCB.  */
  72 # define TLS_TCB_OFFSET         0
  73
  74 /* Install the dtv pointer.  The pointer passed is to the element with
  75    index -1 which contain the length.  */
  76 # define INSTALL_DTV(tcbp, dtvp) \
  77   (((tcbhead_t *) (tcbp))->dtv = (dtvp) + 1)
  78
  79 /* Install new dtv for current thread.  */
  80 # define INSTALL_NEW_DTV(dtv) \
  81   (THREAD_DTV() = (dtv))
  82
  83 /* Return dtv of given thread descriptor.  */
  84 # define GET_DTV(tcbp) \
  85   (((tcbhead_t *) (tcbp))->dtv)
  86
  87 # define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd) + 1
  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) \
  93   ({ long int result_var;                                               \
  94      result_var = INTERNAL_SYSCALL_CALL (set_thread_area,               \
  95                     (char *) (tcbp) + TLS_TCB_OFFSET);                  \
  96      INTERNAL_SYSCALL_ERROR_P (result_var)                              \
  97        ? "unknown error" : NULL; })
  98
  99 /* Return the address of the dtv for the current thread.  */
 100 # define THREAD_DTV() \
 101   (((tcbhead_t *) (READ_THREAD_POINTER () - TLS_TCB_OFFSET))->dtv)
 102
 103 /* Return the thread descriptor for the current thread.  */
 104 # undef THREAD_SELF
 105 # define THREAD_SELF \
 106   ((struct pthread *) (READ_THREAD_POINTER ()                           \
 107                        - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE))
 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 # include <tcb-access.h>
 114
 115 /* Get and set the global scope generation counter in struct pthread.  */
 116 # define THREAD_GSCOPE_FLAG_UNUSED 0
 117 # define THREAD_GSCOPE_FLAG_USED   1
 118 # define THREAD_GSCOPE_FLAG_WAIT   2
 119 # define THREAD_GSCOPE_RESET_FLAG() \
 120   do                                                                          \
 121     { int __res                                                               \
 122         = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,              \
 123                                THREAD_GSCOPE_FLAG_UNUSED);                    \
 124       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                   \
 125         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);    \
 126     }                                                                         \
 127   while (0)
 128 # define THREAD_GSCOPE_SET_FLAG() \
 129   do                                                                          \
 130     {                                                                         \
 131       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;              \
 132       atomic_write_barrier ();                                                \
 133     }                                                                         \
 134   while (0)
 135
 136 #endif /* __ASSEMBLER__ */
 137
 138 #endif /* tls.h */