sysdeps/hppa/nptl/tls.h

   1 /* Definition for thread-local data handling.  NPTL/hppa version.
   2    Copyright (C) 2005-2021 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 #else /* __ASSEMBLER__ */
  31 # include <tcb-offsets.h>
  32 #endif /* __ASSEMBLER__ */
  33
  34 #ifndef __ASSEMBLER__
  35
  36 /* Get system call information.  */
  37 # include <sysdep.h>
  38
  39 /* The TP points to the start of the thread blocks.  */
  40 # define TLS_DTV_AT_TP  1
  41 # define TLS_TCB_AT_TP  0
  42
  43 /* Get the thread descriptor definition.  */
  44 # include <nptl/descr.h>
  45
  46 typedef struct
  47 {
  48   dtv_t *dtv;
  49   void *private;
  50 } tcbhead_t;
  51
  52 /* This is the size of the initial TCB.  */
  53 # define TLS_INIT_TCB_SIZE      sizeof (tcbhead_t)
  54
  55 /* This is the size of the TCB.  */
  56 # define TLS_TCB_SIZE           sizeof (tcbhead_t)
  57
  58 /* This is the size we need before TCB */
  59 # define TLS_PRE_TCB_SIZE       sizeof (struct pthread)
  60
  61 /* Install the dtv pointer.  The pointer passed is to the element with
  62    index -1 which contain the length.  */
  63 # define INSTALL_DTV(tcbp, dtvp) \
  64   ((tcbhead_t *) (tcbp))->dtv = (dtvp) + 1
  65
  66 /* Install new dtv for current thread.  */
  67 # define INSTALL_NEW_DTV(dtv) \
  68   ({ tcbhead_t *__tcbp = (tcbhead_t *)__get_cr27();     \
  69         __tcbp->dtv = dtv;                              \
  70    })
  71
  72 /* Return dtv of given thread descriptor.  */
  73 # define GET_DTV(tcbp) \
  74   (((tcbhead_t *) (tcbp))->dtv)
  75
  76 /* Code to initially initialize the thread pointer.  This might need
  77    special attention since 'errno' is not yet available and if the
  78    operation can cause a failure 'errno' must not be touched.  */
  79 # define TLS_INIT_TP(tcbp) \
  80   ({ __set_cr27(tcbp); NULL; })
  81
  82 /* Value passed to 'clone' for initialization of the thread register.  */
  83 # define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd) + 1
  84
  85 /* Return the address of the dtv for the current thread.  */
  86 # define THREAD_DTV() \
  87   ({ tcbhead_t *__tcbp = (tcbhead_t *)__get_cr27();     \
  88         __tcbp->dtv;                                    \
  89    })
  90
  91 /* Return the thread descriptor for the current thread.  */
  92 # define THREAD_SELF \
  93   ({ struct pthread *__self;                    \
  94         __self = __get_cr27();                  \
  95         __self - 1;                             \
  96    })
  97
  98 /* Magic for libthread_db to know how to do THREAD_SELF.
  99    Our thread pointer is stored in cr27.  See asm/elf.h for the offset into
 100    elf_gregset_t.  The thread descriptor is sizeof (struct pthread) away.  */
 101 # define DB_THREAD_SELF \
 102   REGISTER (32, 32, 53 * 4, -sizeof (struct pthread))
 103
 104 # include <tcb-access.h>
 105
 106 static inline struct pthread *__get_cr27(void)
 107 {
 108   long cr27;
 109   asm ("mfctl %%cr27, %0" : "=r" (cr27) : );
 110   return (struct pthread *) cr27;
 111 }
 112
 113 /* We write to cr27, clobber r26 as the input argument, and clobber
 114    r31 as the link register.  */
 115 static inline void __set_cr27(struct pthread *cr27)
 116 {
 117   asm ( "ble    0xe0(%%sr2, %%r0)\n\t"
 118         "copy   %0, %%r26"
 119         : : "r" (cr27) : "r26", "r31" );
 120 }
 121
 122 /* Get and set the global scope generation counter in struct pthread.  */
 123 #define THREAD_GSCOPE_FLAG_UNUSED 0
 124 #define THREAD_GSCOPE_FLAG_USED   1
 125 #define THREAD_GSCOPE_FLAG_WAIT   2
 126 #define THREAD_GSCOPE_RESET_FLAG() \
 127   do                                                                         \
 128     { int __res                                                              \
 129         = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,             \
 130                                THREAD_GSCOPE_FLAG_UNUSED);                   \
 131       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                  \
 132         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);   \
 133     }                                                                        \
 134   while (0)
 135 #define THREAD_GSCOPE_SET_FLAG() \
 136   do                                                                         \
 137     {                                                                        \
 138       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;             \
 139       atomic_write_barrier ();                                               \
 140     }                                                                        \
 141   while (0)
 142
 143 #endif /* !__ASSEMBLER__ */
 144
 145 #endif  /* tls.h */