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