sysdeps/mips/nptl/tls.h

   1 /* Definition for thread-local data handling.  NPTL/MIPS version.
   2    Copyright (C) 2005-2019 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 # include <dl-dtv.h>
  29
  30 /* Get system call information.  */
  31 # include <sysdep.h>
  32
  33 #ifdef __mips16
  34 /* MIPS16 uses GCC builtin to access the TP.  */
  35 # define READ_THREAD_POINTER() (__builtin_thread_pointer ())
  36 #else
  37 /* Note: rd must be $v1 to be ABI-conformant.  */
  38 # if __mips_isa_rev >= 2
  39 #  define READ_THREAD_POINTER() \
  40      ({ void *__result;                                                       \
  41         asm volatile ("rdhwr\t%0, $29" : "=v" (__result));                    \
  42         __result; })
  43 # else
  44 #  define READ_THREAD_POINTER() \
  45      ({ void *__result;                                                       \
  46         asm volatile (".set\tpush\n\t.set\tmips32r2\n\t"                              \
  47                       "rdhwr\t%0, $29\n\t.set\tpop" : "=v" (__result));       \
  48         __result; })
  49 # endif
  50 #endif
  51
  52 #else /* __ASSEMBLER__ */
  53 # include <tcb-offsets.h>
  54
  55 # if __mips_isa_rev >= 2
  56 #  define READ_THREAD_POINTER(rd) rdhwr rd, $29
  57 # else
  58 #  define READ_THREAD_POINTER(rd) \
  59          .set   push;                                                         \
  60          .set   mips32r2;                                                     \
  61          rdhwr  rd, $29;                                                      \
  62          .set   pop
  63 # endif
  64 #endif /* __ASSEMBLER__ */
  65
  66
  67 #ifndef __ASSEMBLER__
  68
  69 /* The TP points to the start of the thread blocks.  */
  70 # define TLS_DTV_AT_TP  1
  71 # define TLS_TCB_AT_TP  0
  72
  73 /* Get the thread descriptor definition.  */
  74 # include <nptl/descr.h>
  75
  76 typedef struct
  77 {
  78   dtv_t *dtv;
  79   void *private;
  80 } tcbhead_t;
  81
  82 /* This is the size of the initial TCB.  Because our TCB is before the thread
  83    pointer, we don't need this.  */
  84 # define TLS_INIT_TCB_SIZE      0
  85
  86 /* Alignment requirements for the initial TCB.  */
  87 # define TLS_INIT_TCB_ALIGN     __alignof__ (struct pthread)
  88
  89 /* This is the size of the TCB.  Because our TCB is before the thread
  90    pointer, we don't need this.  */
  91 # define TLS_TCB_SIZE           0
  92
  93 /* Alignment requirements for the TCB.  */
  94 # define TLS_TCB_ALIGN          __alignof__ (struct pthread)
  95
  96 /* This is the size we need before TCB - actually, it includes the TCB.  */
  97 # define TLS_PRE_TCB_SIZE \
  98   (sizeof (struct pthread)                                                    \
  99    + ((sizeof (tcbhead_t) + TLS_TCB_ALIGN - 1) & ~(TLS_TCB_ALIGN - 1)))
 100
 101 /* The thread pointer (in hardware register $29) points to the end of
 102    the TCB + 0x7000, as for PowerPC.  The pthread_descr structure is
 103    immediately in front of the TCB.  */
 104 # define TLS_TCB_OFFSET 0x7000
 105
 106 /* Install the dtv pointer.  The pointer passed is to the element with
 107    index -1 which contain the length.  */
 108 # define INSTALL_DTV(tcbp, dtvp) \
 109   (((tcbhead_t *) (tcbp))[-1].dtv = (dtvp) + 1)
 110
 111 /* Install new dtv for current thread.  */
 112 # define INSTALL_NEW_DTV(dtv) \
 113   (THREAD_DTV() = (dtv))
 114
 115 /* Return dtv of given thread descriptor.  */
 116 # define GET_DTV(tcbp) \
 117   (((tcbhead_t *) (tcbp))[-1].dtv)
 118
 119 /* Code to initially initialize the thread pointer.  This might need
 120    special attention since 'errno' is not yet available and if the
 121    operation can cause a failure 'errno' must not be touched.  */
 122 # define TLS_INIT_TP(tcbp) \
 123   ({ INTERNAL_SYSCALL_DECL (err);                                       \
 124      long result_var;                                                   \
 125      result_var = INTERNAL_SYSCALL (set_thread_area, err, 1,            \
 126                                     (char *) (tcbp) + TLS_TCB_OFFSET);  \
 127      INTERNAL_SYSCALL_ERROR_P (result_var, err)                         \
 128        ? "unknown error" : NULL; })
 129
 130 /* Value passed to 'clone' for initialization of the thread register.  */
 131 # define TLS_DEFINE_INIT_TP(tp, pd) \
 132   void *tp = (void *) (pd) + TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE
 133
 134 /* Return the address of the dtv for the current thread.  */
 135 # define THREAD_DTV() \
 136   (((tcbhead_t *) (READ_THREAD_POINTER () - TLS_TCB_OFFSET))[-1].dtv)
 137
 138 /* Return the thread descriptor for the current thread.  */
 139 # define THREAD_SELF \
 140  ((struct pthread *) (READ_THREAD_POINTER ()                         \
 141                       - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE))
 142
 143 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 144 # define DB_THREAD_SELF \
 145   CONST_THREAD_AREA (32, TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE)
 146
 147 /* Access to data in the thread descriptor is easy.  */
 148 # define THREAD_GETMEM(descr, member) \
 149   descr->member
 150 # define THREAD_GETMEM_NC(descr, member, idx) \
 151   descr->member[idx]
 152 # define THREAD_SETMEM(descr, member, value) \
 153   descr->member = (value)
 154 # define THREAD_SETMEM_NC(descr, member, idx, value) \
 155   descr->member[idx] = (value)
 156
 157 /* l_tls_offset == 0 is perfectly valid on MIPS, so we have to use some
 158    different value to mean unset l_tls_offset.  */
 159 # define NO_TLS_OFFSET          -1
 160
 161 /* Get and set the global scope generation counter in struct pthread.  */
 162 #define THREAD_GSCOPE_IN_TCB      1
 163 #define THREAD_GSCOPE_FLAG_UNUSED 0
 164 #define THREAD_GSCOPE_FLAG_USED   1
 165 #define THREAD_GSCOPE_FLAG_WAIT   2
 166 #define THREAD_GSCOPE_RESET_FLAG() \
 167   do                                                                         \
 168     { int __res                                                              \
 169         = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,             \
 170                                THREAD_GSCOPE_FLAG_UNUSED);                   \
 171       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                  \
 172         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);   \
 173     }                                                                        \
 174   while (0)
 175 #define THREAD_GSCOPE_SET_FLAG() \
 176   do                                                                         \
 177     {                                                                        \
 178       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;             \
 179       atomic_write_barrier ();                                               \
 180     }                                                                        \
 181   while (0)
 182 #define THREAD_GSCOPE_WAIT() \
 183   GL(dl_wait_lookup_done) ()
 184
 185 #endif /* __ASSEMBLER__ */
 186
 187 #endif  /* tls.h */