sysdeps/mips/nptl/tls.h

   1 /* Definition for thread-local data handling.  NPTL/MIPS version.
   2    Copyright (C) 2005, 2007 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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #ifndef _TLS_H
  21 #define _TLS_H  1
  22
  23 #include <dl-sysdep.h>
  24
  25 #ifndef __ASSEMBLER__
  26 # include <stdbool.h>
  27 # include <stddef.h>
  28 # include <stdint.h>
  29
  30 /* Type for the dtv.  */
  31 typedef union dtv
  32 {
  33   size_t counter;
  34   struct
  35   {
  36     void *val;
  37     bool is_static;
  38   } pointer;
  39 } dtv_t;
  40
  41 /* Note: rd must be $v1 to be ABI-conformant.  */
  42 # define READ_THREAD_POINTER() \
  43     ({ void *__result;                                                        \
  44        asm volatile (".set\tpush\n\t.set\tmips32r2\n\t"                       \
  45                      "rdhwr\t%0, $29\n\t.set\tpop" : "=v" (__result));        \
  46        __result; })
  47
  48 #else /* __ASSEMBLER__ */
  49 # include <tcb-offsets.h>
  50
  51 # define READ_THREAD_POINTER(rd) \
  52         .set    push;                                                         \
  53         .set    mips32r2;                                                     \
  54         rdhwr   rd, $29;                                                      \
  55         .set    pop
  56 #endif /* __ASSEMBLER__ */
  57
  58
  59 /* We require TLS support in the tools.  */
  60 #ifndef HAVE_TLS_SUPPORT
  61 # error "TLS support is required."
  62 #endif
  63
  64 /* Signal that TLS support is available.  */
  65 #define USE_TLS 1
  66
  67 #ifndef __ASSEMBLER__
  68
  69 /* Get system call information.  */
  70 # include <sysdep.h>
  71
  72 /* The TP points to the start of the thread blocks.  */
  73 # define TLS_DTV_AT_TP  1
  74
  75 /* Get the thread descriptor definition.  */
  76 # include <nptl/descr.h>
  77
  78 typedef struct
  79 {
  80   dtv_t *dtv;
  81   void *private;
  82 } tcbhead_t;
  83
  84 /* This is the size of the initial TCB.  Because our TCB is before the thread
  85    pointer, we don't need this.  */
  86 # define TLS_INIT_TCB_SIZE      0
  87
  88 /* Alignment requirements for the initial TCB.  */
  89 # define TLS_INIT_TCB_ALIGN     __alignof__ (struct pthread)
  90
  91 /* This is the size of the TCB.  Because our TCB is before the thread
  92    pointer, we don't need this.  */
  93 # define TLS_TCB_SIZE           0
  94
  95 /* Alignment requirements for the TCB.  */
  96 # define TLS_TCB_ALIGN          __alignof__ (struct pthread)
  97
  98 /* This is the size we need before TCB - actually, it includes the TCB.  */
  99 # define TLS_PRE_TCB_SIZE \
 100   (sizeof (struct pthread)                                                    \
 101    + ((sizeof (tcbhead_t) + TLS_TCB_ALIGN - 1) & ~(TLS_TCB_ALIGN - 1)))
 102
 103 /* The thread pointer (in hardware register $29) points to the end of
 104    the TCB + 0x7000, as for PowerPC.  The pthread_descr structure is
 105    immediately in front of the TCB.  */
 106 # define TLS_TCB_OFFSET 0x7000
 107
 108 /* Install the dtv pointer.  The pointer passed is to the element with
 109    index -1 which contain the length.  */
 110 # define INSTALL_DTV(tcbp, dtvp) \
 111   (((tcbhead_t *) (tcbp))[-1].dtv = (dtvp) + 1)
 112
 113 /* Install new dtv for current thread.  */
 114 # define INSTALL_NEW_DTV(dtv) \
 115   (THREAD_DTV() = (dtv))
 116
 117 /* Return dtv of given thread descriptor.  */
 118 # define GET_DTV(tcbp) \
 119   (((tcbhead_t *) (tcbp))[-1].dtv)
 120
 121 /* Code to initially initialize the thread pointer.  This might need
 122    special attention since 'errno' is not yet available and if the
 123    operation can cause a failure 'errno' must not be touched.  */
 124 # define TLS_INIT_TP(tcbp, secondcall) \
 125   ({ INTERNAL_SYSCALL_DECL (err);                                       \
 126      long result_var;                                                   \
 127      result_var = INTERNAL_SYSCALL (set_thread_area, err, 1,            \
 128                                     (char *) (tcbp) + TLS_TCB_OFFSET);  \
 129      INTERNAL_SYSCALL_ERROR_P (result_var, err)                         \
 130        ? "unknown error" : NULL; })
 131
 132 /* Return the address of the dtv for the current thread.  */
 133 # define THREAD_DTV() \
 134   (((tcbhead_t *) (READ_THREAD_POINTER () - TLS_TCB_OFFSET))[-1].dtv)
 135
 136 /* Return the thread descriptor for the current thread.  */
 137 # define THREAD_SELF \
 138  ((struct pthread *) (READ_THREAD_POINTER ()                         \
 139                       - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE))
 140
 141 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 142 # define DB_THREAD_SELF \
 143   CONST_THREAD_AREA (32, TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE)
 144
 145 /* Access to data in the thread descriptor is easy.  */
 146 # define THREAD_GETMEM(descr, member) \
 147   descr->member
 148 # define THREAD_GETMEM_NC(descr, member, idx) \
 149   descr->member[idx]
 150 # define THREAD_SETMEM(descr, member, value) \
 151   descr->member = (value)
 152 # define THREAD_SETMEM_NC(descr, member, idx, value) \
 153   descr->member[idx] = (value)
 154
 155 /* l_tls_offset == 0 is perfectly valid on MIPS, so we have to use some
 156    different value to mean unset l_tls_offset.  */
 157 # define NO_TLS_OFFSET          -1
 158
 159 /* Get and set the global scope generation counter in struct pthread.  */
 160 #define THREAD_GSCOPE_FLAG_UNUSED 0
 161 #define THREAD_GSCOPE_FLAG_USED   1
 162 #define THREAD_GSCOPE_FLAG_WAIT   2
 163 #define THREAD_GSCOPE_RESET_FLAG() \
 164   do                                                                         \
 165     { int __res                                                              \
 166         = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,             \
 167                                THREAD_GSCOPE_FLAG_UNUSED);                   \
 168       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                  \
 169         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);   \
 170     }                                                                        \
 171   while (0)
 172 #define THREAD_GSCOPE_SET_FLAG() \
 173   do                                                                         \
 174     {                                                                        \
 175       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;             \
 176       atomic_write_barrier ();                                               \
 177     }                                                                        \
 178   while (0)
 179 #define THREAD_GSCOPE_WAIT() \
 180   GL(dl_wait_lookup_done) ()
 181
 182 #endif /* __ASSEMBLER__ */
 183
 184 #endif  /* tls.h */