nptl/sysdeps/powerpc/tls.h

   1 /* Definition for thread-local data handling.  NPTL/PowerPC version.
   2    Copyright (C) 2003, 2005, 2007 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 <stdbool.h>
  27 # include <stddef.h>
  28 # include <stdint.h>
  29
  30 /* Type for the dtv.  */
  31 typedef union dtv
  32 {
  33   size_t counter;
  34   struct
  35   {
  36     void *val;
  37     bool is_static;
  38   } pointer;
  39 } dtv_t;
  40
  41 #else /* __ASSEMBLER__ */
  42 # include <tcb-offsets.h>
  43 #endif /* __ASSEMBLER__ */
  44
  45
  46 /* We require TLS support in the tools.  */
  47 #ifndef HAVE_TLS_SUPPORT
  48 # error "TLS support is required."
  49 #endif
  50
  51 /* Signal that TLS support is available.  */
  52 # define USE_TLS        1
  53
  54 #ifndef __ASSEMBLER__
  55
  56 /* Get system call information.  */
  57 # include <sysdep.h>
  58
  59 /* The TP points to the start of the thread blocks.  */
  60 # define TLS_DTV_AT_TP  1
  61
  62 /* We use the multiple_threads field in the pthread struct */
  63 #define TLS_MULTIPLE_THREADS_IN_TCB     1
  64
  65 /* Get the thread descriptor definition.  */
  66 # include <nptl/descr.h>
  67
  68 /* The stack_guard is accessed directly by GCC -fstack-protector code,
  69    so it is a part of public ABI.  The dtv and pointer_guard fields
  70    are private.  */
  71 typedef struct
  72 {
  73   uintptr_t pointer_guard;
  74   uintptr_t stack_guard;
  75   dtv_t *dtv;
  76 } tcbhead_t;
  77
  78 /* This is the size of the initial TCB.  */
  79 # define TLS_INIT_TCB_SIZE      0
  80
  81 /* Alignment requirements for the initial TCB.  */
  82 # define TLS_INIT_TCB_ALIGN     __alignof__ (struct pthread)
  83
  84 /* This is the size of the TCB.  */
  85 # define TLS_TCB_SIZE           0
  86
  87 /* Alignment requirements for the TCB.  */
  88 # define TLS_TCB_ALIGN          __alignof__ (struct pthread)
  89
  90 /* This is the size we need before TCB.  */
  91 # define TLS_PRE_TCB_SIZE \
  92   (sizeof (struct pthread)                                                    \
  93    + ((sizeof (tcbhead_t) + TLS_TCB_ALIGN - 1) & ~(TLS_TCB_ALIGN - 1)))
  94
  95 # ifndef __powerpc64__
  96 /* Register r2 (tp) is reserved by the ABI as "thread pointer". */
  97 register void *__thread_register __asm__ ("r2");
  98 #  define PT_THREAD_POINTER PT_R2
  99 # else
 100 /* Register r13 (tp) is reserved by the ABI as "thread pointer". */
 101 register void *__thread_register __asm__ ("r13");
 102 #  define PT_THREAD_POINTER PT_R13
 103 # endif
 104
 105 /* The following assumes that TP (R2 or R13) points to the end of the
 106    TCB + 0x7000 (per the ABI).  This implies that TCB address is
 107    TP - 0x7000.  As we define TLS_DTV_AT_TP we can
 108    assume that the pthread struct is allocated immediately ahead of the
 109    TCB.  This implies that the pthread_descr address is
 110    TP - (TLS_PRE_TCB_SIZE + 0x7000).  */
 111 # define TLS_TCB_OFFSET 0x7000
 112
 113 /* Install the dtv pointer.  The pointer passed is to the element with
 114    index -1 which contain the length.  */
 115 # define INSTALL_DTV(tcbp, dtvp) \
 116   ((tcbhead_t *) (tcbp))[-1].dtv = dtvp + 1
 117
 118 /* Install new dtv for current thread.  */
 119 # define INSTALL_NEW_DTV(dtv) (THREAD_DTV() = (dtv))
 120
 121 /* Return dtv of given thread descriptor.  */
 122 # define GET_DTV(tcbp)  (((tcbhead_t *) (tcbp))[-1].dtv)
 123
 124 /* Code to initially initialize the thread pointer.  This might need
 125    special attention since 'errno' is not yet available and if the
 126    operation can cause a failure 'errno' must not be touched.  */
 127 # define TLS_INIT_TP(tcbp, secondcall) \
 128     (__thread_register = (void *) (tcbp) + TLS_TCB_OFFSET, NULL)
 129
 130 /* Return the address of the dtv for the current thread.  */
 131 # define THREAD_DTV() \
 132     (((tcbhead_t *) (__thread_register - TLS_TCB_OFFSET))[-1].dtv)
 133
 134 /* Return the thread descriptor for the current thread.  */
 135 # define THREAD_SELF \
 136     ((struct pthread *) (__thread_register \
 137                          - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE))
 138
 139 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 140 # define DB_THREAD_SELF                                                       \
 141   REGISTER (32, 32, PT_THREAD_POINTER * 4,                                    \
 142             - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE)                              \
 143   REGISTER (64, 64, PT_THREAD_POINTER * 8,                                    \
 144             - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE)
 145
 146 /* Read member of the thread descriptor directly.  */
 147 # define THREAD_GETMEM(descr, member) ((void)(descr), (THREAD_SELF)->member)
 148
 149 /* Same as THREAD_GETMEM, but the member offset can be non-constant.  */
 150 # define THREAD_GETMEM_NC(descr, member, idx) \
 151     ((void)(descr), (THREAD_SELF)->member[idx])
 152
 153 /* Set member of the thread descriptor directly.  */
 154 # define THREAD_SETMEM(descr, member, value) \
 155     ((void)(descr), (THREAD_SELF)->member = (value))
 156
 157 /* Same as THREAD_SETMEM, but the member offset can be non-constant.  */
 158 # define THREAD_SETMEM_NC(descr, member, idx, value) \
 159     ((void)(descr), (THREAD_SELF)->member[idx] = (value))
 160
 161 /* Set the stack guard field in TCB head.  */
 162 # define THREAD_SET_STACK_GUARD(value) \
 163     (((tcbhead_t *) ((char *) __thread_register                               \
 164                      - TLS_TCB_OFFSET))[-1].stack_guard = (value))
 165 # define THREAD_COPY_STACK_GUARD(descr) \
 166     (((tcbhead_t *) ((char *) (descr)                                         \
 167                      + TLS_PRE_TCB_SIZE))[-1].stack_guard                     \
 168      = ((tcbhead_t *) ((char *) __thread_register                             \
 169                        - TLS_TCB_OFFSET))[-1].stack_guard)
 170
 171 /* Set the stack guard field in TCB head.  */
 172 # define THREAD_GET_POINTER_GUARD() \
 173     (((tcbhead_t *) ((char *) __thread_register                               \
 174                      - TLS_TCB_OFFSET))[-1].pointer_guard)
 175 # define THREAD_SET_POINTER_GUARD(value) \
 176     (THREAD_GET_POINTER_GUARD () = (value))
 177 # define THREAD_COPY_POINTER_GUARD(descr) \
 178     (((tcbhead_t *) ((char *) (descr)                                         \
 179                      + TLS_PRE_TCB_SIZE))[-1].pointer_guard                   \
 180      = THREAD_GET_POINTER_GUARD())
 181
 182 /* l_tls_offset == 0 is perfectly valid on PPC, so we have to use some
 183    different value to mean unset l_tls_offset.  */
 184 # define NO_TLS_OFFSET          -1
 185
 186 /* Get and set the global scope generation counter in struct pthread.  */
 187 #define THREAD_GSCOPE_FLAG_UNUSED 0
 188 #define THREAD_GSCOPE_FLAG_USED   1
 189 #define THREAD_GSCOPE_FLAG_WAIT   2
 190 #define THREAD_GSCOPE_RESET_FLAG() \
 191   do                                                                         \
 192     { int __res                                                              \
 193         = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,             \
 194                                THREAD_GSCOPE_FLAG_UNUSED);                   \
 195       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                  \
 196         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1);                \
 197     }                                                                        \
 198   while (0)
 199 #define THREAD_GSCOPE_SET_FLAG() \
 200   do                                                                         \
 201     {                                                                        \
 202       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;             \
 203       atomic_write_barrier ();                                               \
 204     }                                                                        \
 205   while (0)
 206 #define THREAD_GSCOPE_WAIT() \
 207   GL(dl_wait_lookup_done) ()
 208
 209 #endif /* __ASSEMBLER__ */
 210
 211 #endif  /* tls.h */