sysdeps/nios2/nptl/tls.h

   1 /* Definition for thread-local data handling.  NPTL/Nios II version.
   2    Copyright (C) 2012-2016 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    <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
  45 #ifndef __ASSEMBLER__
  46
  47 /* Get system call information.  */
  48 # include <sysdep.h>
  49
  50 /* The TP points to the start of the thread blocks.  */
  51 # define TLS_DTV_AT_TP  1
  52 # define TLS_TCB_AT_TP  0
  53
  54 /* Get the thread descriptor definition.  */
  55 # include <nptl/descr.h>
  56
  57 typedef struct
  58 {
  59   dtv_t *dtv;
  60   uintptr_t pointer_guard;
  61   unsigned spare[6];
  62 } tcbhead_t;
  63
  64 register struct pthread *__thread_self __asm__("r23");
  65
  66 #define READ_THREAD_POINTER() ((void *) __thread_self)
  67
  68 /* This is the size of the initial TCB.  Because our TCB is before the thread
  69    pointer, we don't need this.  */
  70 # define TLS_INIT_TCB_SIZE      0
  71
  72 /* Alignment requirements for the initial TCB.  */
  73 # define TLS_INIT_TCB_ALIGN     __alignof__ (struct pthread)
  74
  75 /* This is the size of the TCB.  Because our TCB is before the thread
  76    pointer, we don't need this.  */
  77 # define TLS_TCB_SIZE           0
  78
  79 /* Alignment requirements for the TCB.  */
  80 # define TLS_TCB_ALIGN          __alignof__ (struct pthread)
  81
  82 /* This is the size we need before TCB - actually, it includes the TCB.  */
  83 # define TLS_PRE_TCB_SIZE \
  84   (sizeof (struct pthread)                                                    \
  85    + ((sizeof (tcbhead_t) + TLS_TCB_ALIGN - 1) & ~(TLS_TCB_ALIGN - 1)))
  86
  87 /* The thread pointer (in hardware register r23) points to the end of
  88    the TCB + 0x7000, as for PowerPC and MIPS.  */
  89 # define TLS_TCB_OFFSET 0x7000
  90
  91 /* Install the dtv pointer.  The pointer passed is to the element with
  92    index -1 which contain the length.  */
  93 # define INSTALL_DTV(tcbp, dtvp) \
  94   (((tcbhead_t *) (tcbp))[-1].dtv = (dtvp) + 1)
  95
  96 /* Install new dtv for current thread.  */
  97 # define INSTALL_NEW_DTV(dtv) \
  98   (THREAD_DTV() = (dtv))
  99
 100 /* Return dtv of given thread descriptor.  */
 101 # define GET_DTV(tcbp) \
 102   (((tcbhead_t *) (tcbp))[-1].dtv)
 103
 104 /* Code to initially initialize the thread pointer.  */
 105 # define TLS_INIT_TP(tcbp) \
 106   (__thread_self = (struct pthread *) ((char *) tcbp + TLS_TCB_OFFSET), NULL)
 107
 108 /* Value passed to 'clone' for initialization of the thread register.  */
 109 # define TLS_DEFINE_INIT_TP(tp, pd) \
 110   void *tp = (void *) (pd) + TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE
 111
 112 /* Return the address of the dtv for the current thread.  */
 113 # define THREAD_DTV() \
 114   (((tcbhead_t *) (READ_THREAD_POINTER () - TLS_TCB_OFFSET))[-1].dtv)
 115
 116 /* Return the thread descriptor for the current thread.  */
 117 # define THREAD_SELF \
 118  ((struct pthread *) (READ_THREAD_POINTER ()                         \
 119                       - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE))
 120
 121 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 122 # define DB_THREAD_SELF \
 123   REGISTER (32, 32, 23 * 4, -TLS_PRE_TCB_SIZE - TLS_TCB_OFFSET)
 124
 125 /* Access to data in the thread descriptor is easy.  */
 126 # define THREAD_GETMEM(descr, member) \
 127   descr->member
 128 # define THREAD_GETMEM_NC(descr, member, idx) \
 129   descr->member[idx]
 130 # define THREAD_SETMEM(descr, member, value) \
 131   descr->member = (value)
 132 # define THREAD_SETMEM_NC(descr, member, idx, value) \
 133   descr->member[idx] = (value)
 134
 135 # define THREAD_GET_POINTER_GUARD()                             \
 136   (((tcbhead_t *) (READ_THREAD_POINTER ()                       \
 137                    - TLS_TCB_OFFSET))[-1].pointer_guard)
 138 # define THREAD_SET_POINTER_GUARD(value)        \
 139   (THREAD_GET_POINTER_GUARD () = (value))
 140 # define THREAD_COPY_POINTER_GUARD(descr)                               \
 141   (((tcbhead_t *) ((void *) (descr)                                     \
 142                    + TLS_PRE_TCB_SIZE))[-1].pointer_guard               \
 143    = THREAD_GET_POINTER_GUARD())
 144
 145 /* l_tls_offset == 0 is perfectly valid on Nios II, so we have to use some
 146    different value to mean unset l_tls_offset.  */
 147 # define NO_TLS_OFFSET          -1
 148
 149 /* Get and set the global scope generation counter in struct pthread.  */
 150 #define THREAD_GSCOPE_FLAG_UNUSED 0
 151 #define THREAD_GSCOPE_FLAG_USED   1
 152 #define THREAD_GSCOPE_FLAG_WAIT   2
 153 #define THREAD_GSCOPE_RESET_FLAG() \
 154   do                                                                         \
 155     { int __res                                                              \
 156         = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,             \
 157                                THREAD_GSCOPE_FLAG_UNUSED);                   \
 158       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                  \
 159         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);   \
 160     }                                                                        \
 161   while (0)
 162 #define THREAD_GSCOPE_SET_FLAG() \
 163   do                                                                         \
 164     {                                                                        \
 165       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;             \
 166       atomic_write_barrier ();                                               \
 167     }                                                                        \
 168   while (0)
 169 #define THREAD_GSCOPE_WAIT() \
 170   GL(dl_wait_lookup_done) ()
 171
 172 #endif /* __ASSEMBLER__ */
 173
 174 #endif  /* tls.h */