nptl/sysdeps/powerpc/tls.h

   1 /* Definition for thread-local data handling.  NPTL/PowerPC version.
   2    Copyright (C) 2003 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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #ifndef _TLS_H
  21 #define _TLS_H  1
  22
  23 # include <dl-sysdep.h>
  24
  25 #ifndef __ASSEMBLER__
  26 # include <stddef.h>
  27 # include <stdint.h>
  28
  29 /* Type for the dtv.  */
  30 typedef union dtv
  31 {
  32   size_t counter;
  33   void *pointer;
  34 } dtv_t;
  35
  36 #else /* __ASSEMBLER__ */
  37 # include <tcb-offsets.h>
  38 #endif /* __ASSEMBLER__ */
  39
  40
  41 /* We require TLS support in the tools.  */
  42 #ifndef HAVE_TLS_SUPPORT
  43 # error "TLS support is required."
  44 #endif
  45
  46 /* Signal that TLS support is available.  */
  47 # define USE_TLS        1
  48
  49 #ifndef __ASSEMBLER__
  50
  51 /* Get system call information.  */
  52 # include <sysdep.h>
  53
  54 /* The TP points to the start of the thread blocks.  */
  55 # define TLS_DTV_AT_TP  1
  56
  57 /* We use the multiple_threads field in the pthread struct */
  58 #define TLS_MULTIPLE_THREADS_IN_TCB     1
  59
  60 /* Get the thread descriptor definition.  */
  61 # include <nptl/descr.h>
  62
  63 /* This layout is actually wholly private and not affected by the ABI.
  64    Nor does it overlap the pthread data structure, so we need nothing
  65    extra here at all.  */
  66 typedef struct
  67 {
  68   dtv_t *dtv;
  69 } tcbhead_t;
  70
  71 /* This is the size of the initial TCB.  */
  72 # define TLS_INIT_TCB_SIZE      0
  73
  74 /* Alignment requirements for the initial TCB.  */
  75 # define TLS_INIT_TCB_ALIGN     __alignof__ (struct pthread)
  76
  77 /* This is the size of the TCB.  */
  78 # define TLS_TCB_SIZE           0
  79
  80 /* Alignment requirements for the TCB.  */
  81 # define TLS_TCB_ALIGN          __alignof__ (struct pthread)
  82
  83 /* This is the size we need before TCB.  */
  84 # define TLS_PRE_TCB_SIZE \
  85   (sizeof (struct pthread)                                                    \
  86    + ((sizeof (tcbhead_t) + TLS_TCB_ALIGN - 1) & ~(TLS_TCB_ALIGN - 1)))
  87
  88 # ifndef __powerpc64__
  89 /* Register r2 (tp) is reserved by the ABI as "thread pointer". */
  90 register void *__thread_register __asm__ ("r2");
  91 #  define PT_THREAD_POINTER PT_R2
  92 # else
  93 /* Register r13 (tp) is reserved by the ABI as "thread pointer". */
  94 register void *__thread_register __asm__ ("r13");
  95 #  define PT_THREAD_POINTER PT_R13
  96 # endif
  97
  98 /* The following assumes that TP (R2 or R13) points to the end of the
  99    TCB + 0x7000 (per the ABI).  This implies that TCB address is
 100    TP - 0x7000.  As we define TLS_DTV_AT_TP we can
 101    assume that the pthread struct is allocated immediately ahead of the
 102    TCB.  This implies that the pthread_descr address is
 103    TP - (TLS_PRE_TCB_SIZE + 0x7000).  */
 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) (THREAD_DTV() = (dtv))
 113
 114 /* Return dtv of given thread descriptor.  */
 115 # define GET_DTV(tcbp)  (((tcbhead_t *) (tcbp))[-1].dtv)
 116
 117 /* Code to initially initialize the thread pointer.  This might need
 118    special attention since 'errno' is not yet available and if the
 119    operation can cause a failure 'errno' must not be touched.  */
 120 # define TLS_INIT_TP(tcbp, secondcall) \
 121     (__thread_register = (void *) (tcbp) + TLS_TCB_OFFSET, NULL)
 122
 123 /* Return the address of the dtv for the current thread.  */
 124 # define THREAD_DTV() \
 125      (((tcbhead_t *) (__thread_register - TLS_TCB_OFFSET))[-1].dtv)
 126
 127 /* Return the thread descriptor for the current thread.  */
 128 # define THREAD_SELF \
 129     ((struct pthread *) (__thread_register \
 130                          - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE))
 131
 132 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 133 # define DB_THREAD_SELF                                                       \
 134   REGISTER (32, 32, PT_THREAD_POINTER * 4,                                            \
 135             - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE)                              \
 136   REGISTER (64, 64, PT_THREAD_POINTER * 8,                                            \
 137             - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE)
 138
 139 /* Read member of the thread descriptor directly.  */
 140 # define THREAD_GETMEM(descr, member) ((void)(descr), (THREAD_SELF)->member)
 141
 142 /* Same as THREAD_GETMEM, but the member offset can be non-constant.  */
 143 # define THREAD_GETMEM_NC(descr, member, idx) \
 144     ((void)(descr), (THREAD_SELF)->member[idx])
 145
 146 /* Set member of the thread descriptor directly.  */
 147 # define THREAD_SETMEM(descr, member, value) \
 148     ((void)(descr), (THREAD_SELF)->member = (value))
 149
 150 /* Same as THREAD_SETMEM, but the member offset can be non-constant.  */
 151 # define THREAD_SETMEM_NC(descr, member, idx, value) \
 152     ((void)(descr), (THREAD_SELF)->member[idx] = (value))
 153
 154 /* l_tls_offset == 0 is perfectly valid on PPC, so we have to use some
 155    different value to mean unset l_tls_offset.  */
 156 # define NO_TLS_OFFSET          -1
 157
 158 #endif /* __ASSEMBLER__ */
 159
 160 #endif  /* tls.h */