sysdeps/mips/nptl/tls.h

   1 /* Definition for thread-local data handling.  NPTL/MIPS version.
   2    Copyright (C) 2005-2015 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 #ifdef __mips16
  41 /* MIPS16 uses GCC builtin to access the TP.  */
  42 # define READ_THREAD_POINTER() (__builtin_thread_pointer ())
  43 #else
  44 /* Note: rd must be $v1 to be ABI-conformant.  */
  45 # define READ_THREAD_POINTER() \
  46     ({ void *__result;                                                        \
  47        asm volatile (".set\tpush\n\t.set\tmips32r2\n\t"                       \
  48                      "rdhwr\t%0, $29\n\t.set\tpop" : "=v" (__result));        \
  49        __result; })
  50 #endif
  51
  52 #else /* __ASSEMBLER__ */
  53 # include <tcb-offsets.h>
  54
  55 # define READ_THREAD_POINTER(rd) \
  56         .set    push;                                                         \
  57         .set    mips32r2;                                                     \
  58         rdhwr   rd, $29;                                                      \
  59         .set    pop
  60 #endif /* __ASSEMBLER__ */
  61
  62
  63 #ifndef __ASSEMBLER__
  64
  65 /* Get system call information.  */
  66 # include <sysdep.h>
  67
  68 /* The TP points to the start of the thread blocks.  */
  69 # define TLS_DTV_AT_TP  1
  70 # define TLS_TCB_AT_TP  0
  71
  72 /* Get the thread descriptor definition.  */
  73 # include <nptl/descr.h>
  74
  75 typedef struct
  76 {
  77   dtv_t *dtv;
  78   void *private;
  79 } tcbhead_t;
  80
  81 /* This is the size of the initial TCB.  Because our TCB is before the thread
  82    pointer, we don't need this.  */
  83 # define TLS_INIT_TCB_SIZE      0
  84
  85 /* Alignment requirements for the initial TCB.  */
  86 # define TLS_INIT_TCB_ALIGN     __alignof__ (struct pthread)
  87
  88 /* This is the size of the TCB.  Because our TCB is before the thread
  89    pointer, we don't need this.  */
  90 # define TLS_TCB_SIZE           0
  91
  92 /* Alignment requirements for the TCB.  */
  93 # define TLS_TCB_ALIGN          __alignof__ (struct pthread)
  94
  95 /* This is the size we need before TCB - actually, it includes the TCB.  */
  96 # define TLS_PRE_TCB_SIZE \
  97   (sizeof (struct pthread)                                                    \
  98    + ((sizeof (tcbhead_t) + TLS_TCB_ALIGN - 1) & ~(TLS_TCB_ALIGN - 1)))
  99
 100 /* The thread pointer (in hardware register $29) points to the end of
 101    the TCB + 0x7000, as for PowerPC.  The pthread_descr structure is
 102    immediately in front of the TCB.  */
 103 # define TLS_TCB_OFFSET 0x7000
 104
 105 /* Install the dtv pointer.  The pointer passed is to the element with
 106    index -1 which contain the length.  */
 107 # define INSTALL_DTV(tcbp, dtvp) \
 108   (((tcbhead_t *) (tcbp))[-1].dtv = (dtvp) + 1)
 109
 110 /* Install new dtv for current thread.  */
 111 # define INSTALL_NEW_DTV(dtv) \
 112   (THREAD_DTV() = (dtv))
 113
 114 /* Return dtv of given thread descriptor.  */
 115 # define GET_DTV(tcbp) \
 116   (((tcbhead_t *) (tcbp))[-1].dtv)
 117
 118 /* Code to initially initialize the thread pointer.  This might need
 119    special attention since 'errno' is not yet available and if the
 120    operation can cause a failure 'errno' must not be touched.  */
 121 # define TLS_INIT_TP(tcbp) \
 122   ({ INTERNAL_SYSCALL_DECL (err);                                       \
 123      long result_var;                                                   \
 124      result_var = INTERNAL_SYSCALL (set_thread_area, err, 1,            \
 125                                     (char *) (tcbp) + TLS_TCB_OFFSET);  \
 126      INTERNAL_SYSCALL_ERROR_P (result_var, err)                         \
 127        ? "unknown error" : NULL; })
 128
 129 /* Value passed to 'clone' for initialization of the thread register.  */
 130 # define TLS_DEFINE_INIT_TP(tp, pd) \
 131   void *tp = (void *) (pd) + TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE
 132
 133 /* Return the address of the dtv for the current thread.  */
 134 # define THREAD_DTV() \
 135   (((tcbhead_t *) (READ_THREAD_POINTER () - TLS_TCB_OFFSET))[-1].dtv)
 136
 137 /* Return the thread descriptor for the current thread.  */
 138 # define THREAD_SELF \
 139  ((struct pthread *) (READ_THREAD_POINTER ()                         \
 140                       - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE))
 141
 142 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 143 # define DB_THREAD_SELF \
 144   CONST_THREAD_AREA (32, TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE)
 145
 146 /* Access to data in the thread descriptor is easy.  */
 147 # define THREAD_GETMEM(descr, member) \
 148   descr->member
 149 # define THREAD_GETMEM_NC(descr, member, idx) \
 150   descr->member[idx]
 151 # define THREAD_SETMEM(descr, member, value) \
 152   descr->member = (value)
 153 # define THREAD_SETMEM_NC(descr, member, idx, value) \
 154   descr->member[idx] = (value)
 155
 156 /* l_tls_offset == 0 is perfectly valid on MIPS, so we have to use some
 157    different value to mean unset l_tls_offset.  */
 158 # define NO_TLS_OFFSET          -1
 159
 160 /* Get and set the global scope generation counter in struct pthread.  */
 161 #define THREAD_GSCOPE_FLAG_UNUSED 0
 162 #define THREAD_GSCOPE_FLAG_USED   1
 163 #define THREAD_GSCOPE_FLAG_WAIT   2
 164 #define THREAD_GSCOPE_RESET_FLAG() \
 165   do                                                                         \
 166     { int __res                                                              \
 167         = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,             \
 168                                THREAD_GSCOPE_FLAG_UNUSED);                   \
 169       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                  \
 170         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);   \
 171     }                                                                        \
 172   while (0)
 173 #define THREAD_GSCOPE_SET_FLAG() \
 174   do                                                                         \
 175     {                                                                        \
 176       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;             \
 177       atomic_write_barrier ();                                               \
 178     }                                                                        \
 179   while (0)
 180 #define THREAD_GSCOPE_WAIT() \
 181   GL(dl_wait_lookup_done) ()
 182
 183 #endif /* __ASSEMBLER__ */
 184
 185 #endif  /* tls.h */