sysdeps/hppa/nptl/tls.h

   1 /* Definition for thread-local data handling.  NPTL/hppa version.
   2    Copyright (C) 2005-2022 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 #endif /* __ASSEMBLER__ */
  30
  31 #ifndef __ASSEMBLER__
  32
  33 /* Get system call information.  */
  34 # include <sysdep.h>
  35
  36 /* The TP points to the start of the thread blocks.  */
  37 # define TLS_DTV_AT_TP  1
  38 # define TLS_TCB_AT_TP  0
  39
  40 /* Get the thread descriptor definition.  */
  41 # include <nptl/descr.h>
  42
  43 typedef struct
  44 {
  45   dtv_t *dtv;
  46   void *private;
  47 } tcbhead_t;
  48
  49 /* This is the size of the initial TCB.  */
  50 # define TLS_INIT_TCB_SIZE      sizeof (tcbhead_t)
  51
  52 /* This is the size of the TCB.  */
  53 # define TLS_TCB_SIZE           sizeof (tcbhead_t)
  54
  55 /* This is the size we need before TCB */
  56 # define TLS_PRE_TCB_SIZE       sizeof (struct pthread)
  57
  58 /* Install the dtv pointer.  The pointer passed is to the element with
  59    index -1 which contain the length.  */
  60 # define INSTALL_DTV(tcbp, dtvp) \
  61   ((tcbhead_t *) (tcbp))->dtv = (dtvp) + 1
  62
  63 /* Install new dtv for current thread.  */
  64 # define INSTALL_NEW_DTV(dtv) \
  65   ({ tcbhead_t *__tcbp = (tcbhead_t *)__get_cr27();     \
  66         __tcbp->dtv = dtv;                              \
  67    })
  68
  69 /* Return dtv of given thread descriptor.  */
  70 # define GET_DTV(tcbp) \
  71   (((tcbhead_t *) (tcbp))->dtv)
  72
  73 /* Code to initially initialize the thread pointer.  This might need
  74    special attention since 'errno' is not yet available and if the
  75    operation can cause a failure 'errno' must not be touched.  */
  76 # define TLS_INIT_TP(tcbp) \
  77   ({ __set_cr27(tcbp); NULL; })
  78
  79 /* Value passed to 'clone' for initialization of the thread register.  */
  80 # define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd) + 1
  81
  82 /* Return the address of the dtv for the current thread.  */
  83 # define THREAD_DTV() \
  84   ({ tcbhead_t *__tcbp = (tcbhead_t *)__get_cr27();     \
  85         __tcbp->dtv;                                    \
  86    })
  87
  88 /* Return the thread descriptor for the current thread.  */
  89 # define THREAD_SELF \
  90   ({ struct pthread *__self;                    \
  91         __self = __get_cr27();                  \
  92         __self - 1;                             \
  93    })
  94
  95 /* Magic for libthread_db to know how to do THREAD_SELF.
  96    Our thread pointer is stored in cr27.  See asm/elf.h for the offset into
  97    elf_gregset_t.  The thread descriptor is sizeof (struct pthread) away.  */
  98 # define DB_THREAD_SELF \
  99   REGISTER (32, 32, 53 * 4, -sizeof (struct pthread))
 100
 101 # include <tcb-access.h>
 102
 103 static inline struct pthread *__get_cr27(void)
 104 {
 105   long cr27;
 106   asm ("mfctl %%cr27, %0" : "=r" (cr27) : );
 107   return (struct pthread *) cr27;
 108 }
 109
 110 /* We write to cr27, clobber r26 as the input argument, and clobber
 111    r31 as the link register.  */
 112 static inline void __set_cr27(struct pthread *cr27)
 113 {
 114   asm ( "ble    0xe0(%%sr2, %%r0)\n\t"
 115         "copy   %0, %%r26"
 116         : : "r" (cr27) : "r26", "r31" );
 117 }
 118
 119 /* Get and set the global scope generation counter in struct pthread.  */
 120 #define THREAD_GSCOPE_FLAG_UNUSED 0
 121 #define THREAD_GSCOPE_FLAG_USED   1
 122 #define THREAD_GSCOPE_FLAG_WAIT   2
 123 #define THREAD_GSCOPE_RESET_FLAG() \
 124   do                                                                         \
 125     { int __res                                                              \
 126         = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,             \
 127                                THREAD_GSCOPE_FLAG_UNUSED);                   \
 128       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                  \
 129         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);   \
 130     }                                                                        \
 131   while (0)
 132 #define THREAD_GSCOPE_SET_FLAG() \
 133   do                                                                         \
 134     {                                                                        \
 135       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;             \
 136       atomic_write_barrier ();                                               \
 137     }                                                                        \
 138   while (0)
 139
 140 #endif /* !__ASSEMBLER__ */
 141
 142 #endif  /* tls.h */