sysdeps/nios2/nptl/tls.h

   1 /* Definition for thread-local data handling.  NPTL/Nios II version.
   2    Copyright (C) 2012-2022 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 #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
  35 #ifndef __ASSEMBLER__
  36
  37 /* Get system call information.  */
  38 # include <sysdep.h>
  39
  40 /* The TP points to the start of the thread blocks.  */
  41 # define TLS_DTV_AT_TP  1
  42 # define TLS_TCB_AT_TP  0
  43
  44 /* Get the thread descriptor definition.  */
  45 # include <nptl/descr.h>
  46
  47 typedef struct
  48 {
  49   dtv_t *dtv;
  50   uintptr_t pointer_guard;
  51   unsigned spare[6];
  52 } tcbhead_t;
  53
  54 register struct pthread *__thread_self __asm__("r23");
  55
  56 #define READ_THREAD_POINTER() ((void *) __thread_self)
  57
  58 /* This is the size of the initial TCB.  Because our TCB is before the thread
  59    pointer, we don't need this.  */
  60 # define TLS_INIT_TCB_SIZE      0
  61
  62 /* This is the size of the TCB.  Because our TCB is before the thread
  63    pointer, we don't need this.  */
  64 # define TLS_TCB_SIZE           0
  65
  66 /* This is the size we need before TCB - actually, it includes the TCB.  */
  67 # define TLS_PRE_TCB_SIZE \
  68   (sizeof (struct pthread)                                                    \
  69    + ((sizeof (tcbhead_t) + __alignof (struct pthread) - 1)                   \
  70       & ~(__alignof (struct pthread) - 1)))
  71
  72 /* The thread pointer (in hardware register r23) points to the end of
  73    the TCB + 0x7000, as for PowerPC and MIPS.  */
  74 # define TLS_TCB_OFFSET 0x7000
  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))[-1].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))[-1].dtv)
  88
  89 /* Code to initially initialize the thread pointer.  */
  90 # define TLS_INIT_TP(tcbp) \
  91   (__thread_self = (struct pthread *) ((char *) tcbp + TLS_TCB_OFFSET), NULL)
  92
  93 /* Value passed to 'clone' for initialization of the thread register.  */
  94 # define TLS_DEFINE_INIT_TP(tp, pd) \
  95   void *tp = (void *) (pd) + TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE
  96
  97 /* Return the address of the dtv for the current thread.  */
  98 # define THREAD_DTV() \
  99   (((tcbhead_t *) (READ_THREAD_POINTER () - TLS_TCB_OFFSET))[-1].dtv)
 100
 101 /* Return the thread descriptor for the current thread.  */
 102 # define THREAD_SELF \
 103  ((struct pthread *) (READ_THREAD_POINTER ()                         \
 104                       - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE))
 105
 106 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 107 # define DB_THREAD_SELF \
 108   REGISTER (32, 32, 23 * 4, -TLS_PRE_TCB_SIZE - TLS_TCB_OFFSET)
 109
 110 # include <tcb-access.h>
 111
 112 # define THREAD_GET_POINTER_GUARD()                             \
 113   (((tcbhead_t *) (READ_THREAD_POINTER ()                       \
 114                    - TLS_TCB_OFFSET))[-1].pointer_guard)
 115 # define THREAD_SET_POINTER_GUARD(value)        \
 116   (THREAD_GET_POINTER_GUARD () = (value))
 117 # define THREAD_COPY_POINTER_GUARD(descr)                               \
 118   (((tcbhead_t *) ((void *) (descr)                                     \
 119                    + TLS_PRE_TCB_SIZE))[-1].pointer_guard               \
 120    = THREAD_GET_POINTER_GUARD())
 121
 122 /* l_tls_offset == 0 is perfectly valid on Nios II, so we have to use some
 123    different value to mean unset l_tls_offset.  */
 124 # define NO_TLS_OFFSET          -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
 147 #endif /* __ASSEMBLER__ */
 148
 149 #endif  /* tls.h */