sysdeps/mips/nptl/tls.h

   1 /* Definition for thread-local data handling.  NPTL/MIPS version.
   2    Copyright (C) 2005-2023 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    <https://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 defined (__mips_isa_rev) &&  __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 # if __mips_isa_rev >= 2
  54 #  define READ_THREAD_POINTER(rd) rdhwr rd, $29
  55 # else
  56 #  define READ_THREAD_POINTER(rd) \
  57          .set   push;                                                         \
  58          .set   mips32r2;                                                     \
  59          rdhwr  rd, $29;                                                      \
  60          .set   pop
  61 # endif
  62 #endif /* __ASSEMBLER__ */
  63
  64
  65 #ifndef __ASSEMBLER__
  66
  67 /* The TP points to the start of the thread blocks.  */
  68 # define TLS_DTV_AT_TP  1
  69 # define TLS_TCB_AT_TP  0
  70
  71 /* Get the thread descriptor definition.  */
  72 # include <nptl/descr.h>
  73
  74 typedef struct
  75 {
  76   dtv_t *dtv;
  77   void *private;
  78 } tcbhead_t;
  79
  80 /* This is the size of the initial TCB.  Because our TCB is before the thread
  81    pointer, we don't need this.  */
  82 # define TLS_INIT_TCB_SIZE      0
  83
  84 /* This is the size of the TCB.  Because our TCB is before the thread
  85    pointer, we don't need this.  */
  86 # define TLS_TCB_SIZE           0
  87
  88 /* This is the size we need before TCB - actually, it includes the TCB.  */
  89 # define TLS_PRE_TCB_SIZE \
  90   (sizeof (struct pthread)                                                    \
  91    + ((sizeof (tcbhead_t) + __alignof (struct pthread) - 1)                   \
  92       & ~(__alignof (struct pthread) - 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) \
 116   ({ long int result_var;                                               \
 117      result_var = INTERNAL_SYSCALL_CALL (set_thread_area,               \
 118                                     (char *) (tcbp) + TLS_TCB_OFFSET);  \
 119      !INTERNAL_SYSCALL_ERROR_P (result_var); })
 120
 121 /* Value passed to 'clone' for initialization of the thread register.  */
 122 # define TLS_DEFINE_INIT_TP(tp, pd) \
 123   void *tp = (void *) (pd) + TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE
 124
 125 /* Return the address of the dtv for the current thread.  */
 126 # define THREAD_DTV() \
 127   (((tcbhead_t *) (READ_THREAD_POINTER () - TLS_TCB_OFFSET))[-1].dtv)
 128
 129 /* Return the thread descriptor for the current thread.  */
 130 # define THREAD_SELF \
 131  ((struct pthread *) (READ_THREAD_POINTER ()                         \
 132                       - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE))
 133
 134 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 135 # define DB_THREAD_SELF \
 136   CONST_THREAD_AREA (32, TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE)
 137
 138 /* Access to data in the thread descriptor is easy.  */
 139 # include <tcb-access.h>
 140
 141 /* l_tls_offset == 0 is perfectly valid on MIPS, so we have to use some
 142    different value to mean unset l_tls_offset.  */
 143 # define NO_TLS_OFFSET          -1
 144
 145 /* Get and set the global scope generation counter in struct pthread.  */
 146 #define THREAD_GSCOPE_FLAG_UNUSED 0
 147 #define THREAD_GSCOPE_FLAG_USED   1
 148 #define THREAD_GSCOPE_FLAG_WAIT   2
 149 #define THREAD_GSCOPE_RESET_FLAG() \
 150   do                                                                         \
 151     { int __res                                                              \
 152         = atomic_exchange_release (&THREAD_SELF->header.gscope_flag,         \
 153                                THREAD_GSCOPE_FLAG_UNUSED);                   \
 154       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                  \
 155         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);   \
 156     }                                                                        \
 157   while (0)
 158 #define THREAD_GSCOPE_SET_FLAG() \
 159   do                                                                         \
 160     {                                                                        \
 161       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;             \
 162       atomic_write_barrier ();                                               \
 163     }                                                                        \
 164   while (0)
 165
 166 #endif /* __ASSEMBLER__ */
 167
 168 #endif  /* tls.h */