nptl/sysdeps/powerpc/tls.h

   1 /* Definition for thread-local data handling.  NPTL/PowerPC version.
   2    Copyright (C) 2003, 2005, 2006, 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 #ifndef __ASSEMBLER__
  52
  53 /* Get system call information.  */
  54 # include <sysdep.h>
  55
  56 /* The TP points to the start of the thread blocks.  */
  57 # define TLS_DTV_AT_TP  1
  58
  59 /* We use the multiple_threads field in the pthread struct */
  60 #define TLS_MULTIPLE_THREADS_IN_TCB     1
  61
  62 /* Get the thread descriptor definition.  */
  63 # include <nptl/descr.h>
  64
  65 /* The stack_guard is accessed directly by GCC -fstack-protector code,
  66    so it is a part of public ABI.  The dtv and pointer_guard fields
  67    are private.  */
  68 typedef struct
  69 {
  70   uintptr_t pointer_guard;
  71   uintptr_t stack_guard;
  72   dtv_t *dtv;
  73 } tcbhead_t;
  74
  75 /* This is the size of the initial TCB.  */
  76 # define TLS_INIT_TCB_SIZE      0
  77
  78 /* Alignment requirements for the initial TCB.  */
  79 # define TLS_INIT_TCB_ALIGN     __alignof__ (struct pthread)
  80
  81 /* This is the size of the TCB.  */
  82 # define TLS_TCB_SIZE           0
  83
  84 /* Alignment requirements for the TCB.  */
  85 # define TLS_TCB_ALIGN          __alignof__ (struct pthread)
  86
  87 /* This is the size we need before TCB.  */
  88 # define TLS_PRE_TCB_SIZE \
  89   (sizeof (struct pthread)                                                    \
  90    + ((sizeof (tcbhead_t) + TLS_TCB_ALIGN - 1) & ~(TLS_TCB_ALIGN - 1)))
  91
  92 # ifndef __powerpc64__
  93 /* Register r2 (tp) is reserved by the ABI as "thread pointer". */
  94 register void *__thread_register __asm__ ("r2");
  95 #  define PT_THREAD_POINTER PT_R2
  96 # else
  97 /* Register r13 (tp) is reserved by the ABI as "thread pointer". */
  98 register void *__thread_register __asm__ ("r13");
  99 #  define PT_THREAD_POINTER PT_R13
 100 # endif
 101
 102 /* The following assumes that TP (R2 or R13) points to the end of the
 103    TCB + 0x7000 (per the ABI).  This implies that TCB address is
 104    TP - 0x7000.  As we define TLS_DTV_AT_TP we can
 105    assume that the pthread struct is allocated immediately ahead of the
 106    TCB.  This implies that the pthread_descr address is
 107    TP - (TLS_PRE_TCB_SIZE + 0x7000).  */
 108 # define TLS_TCB_OFFSET 0x7000
 109
 110 /* Install the dtv pointer.  The pointer passed is to the element with
 111    index -1 which contain the length.  */
 112 # define INSTALL_DTV(tcbp, dtvp) \
 113   ((tcbhead_t *) (tcbp))[-1].dtv = dtvp + 1
 114
 115 /* Install new dtv for current thread.  */
 116 # define INSTALL_NEW_DTV(dtv) (THREAD_DTV() = (dtv))
 117
 118 /* Return dtv of given thread descriptor.  */
 119 # define GET_DTV(tcbp)  (((tcbhead_t *) (tcbp))[-1].dtv)
 120
 121 /* Code to initially initialize the thread pointer.  This might need
 122    special attention since 'errno' is not yet available and if the
 123    operation can cause a failure 'errno' must not be touched.  */
 124 # define TLS_INIT_TP(tcbp, secondcall) \
 125     (__thread_register = (void *) (tcbp) + TLS_TCB_OFFSET, NULL)
 126
 127 /* Return the address of the dtv for the current thread.  */
 128 # define THREAD_DTV() \
 129     (((tcbhead_t *) (__thread_register - TLS_TCB_OFFSET))[-1].dtv)
 130
 131 /* Return the thread descriptor for the current thread.  */
 132 # define THREAD_SELF \
 133     ((struct pthread *) (__thread_register \
 134                          - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE))
 135
 136 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 137 # define DB_THREAD_SELF                                                       \
 138   REGISTER (32, 32, PT_THREAD_POINTER * 4,                                    \
 139             - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE)                              \
 140   REGISTER (64, 64, PT_THREAD_POINTER * 8,                                    \
 141             - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE)
 142
 143 /* Read member of the thread descriptor directly.  */
 144 # define THREAD_GETMEM(descr, member) ((void)(descr), (THREAD_SELF)->member)
 145
 146 /* Same as THREAD_GETMEM, but the member offset can be non-constant.  */
 147 # define THREAD_GETMEM_NC(descr, member, idx) \
 148     ((void)(descr), (THREAD_SELF)->member[idx])
 149
 150 /* Set member of the thread descriptor directly.  */
 151 # define THREAD_SETMEM(descr, member, value) \
 152     ((void)(descr), (THREAD_SELF)->member = (value))
 153
 154 /* Same as THREAD_SETMEM, but the member offset can be non-constant.  */
 155 # define THREAD_SETMEM_NC(descr, member, idx, value) \
 156     ((void)(descr), (THREAD_SELF)->member[idx] = (value))
 157
 158 /* Set the stack guard field in TCB head.  */
 159 # define THREAD_SET_STACK_GUARD(value) \
 160     (((tcbhead_t *) ((char *) __thread_register                               \
 161                      - TLS_TCB_OFFSET))[-1].stack_guard = (value))
 162 # define THREAD_COPY_STACK_GUARD(descr) \
 163     (((tcbhead_t *) ((char *) (descr)                                         \
 164                      + TLS_PRE_TCB_SIZE))[-1].stack_guard                     \
 165      = ((tcbhead_t *) ((char *) __thread_register                             \
 166                        - TLS_TCB_OFFSET))[-1].stack_guard)
 167
 168 /* Set the stack guard field in TCB head.  */
 169 # define THREAD_GET_POINTER_GUARD() \
 170     (((tcbhead_t *) ((char *) __thread_register                               \
 171                      - TLS_TCB_OFFSET))[-1].pointer_guard)
 172 # define THREAD_SET_POINTER_GUARD(value) \
 173     (THREAD_GET_POINTER_GUARD () = (value))
 174 # define THREAD_COPY_POINTER_GUARD(descr) \
 175     (((tcbhead_t *) ((char *) (descr)                                         \
 176                      + TLS_PRE_TCB_SIZE))[-1].pointer_guard                   \
 177      = THREAD_GET_POINTER_GUARD())
 178
 179 /* l_tls_offset == 0 is perfectly valid on PPC, so we have to use some
 180    different value to mean unset l_tls_offset.  */
 181 # define NO_TLS_OFFSET          -1
 182
 183 /* Get and set the global scope generation counter in struct pthread.  */
 184 #define THREAD_GSCOPE_FLAG_UNUSED 0
 185 #define THREAD_GSCOPE_FLAG_USED   1
 186 #define THREAD_GSCOPE_FLAG_WAIT   2
 187 #define THREAD_GSCOPE_RESET_FLAG() \
 188   do                                                                         \
 189     { int __res                                                              \
 190         = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,             \
 191                                THREAD_GSCOPE_FLAG_UNUSED);                   \
 192       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                  \
 193         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);   \
 194     }                                                                        \
 195   while (0)
 196 #define THREAD_GSCOPE_SET_FLAG() \
 197   do                                                                         \
 198     {                                                                        \
 199       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;             \
 200       atomic_write_barrier ();                                               \
 201     }                                                                        \
 202   while (0)
 203 #define THREAD_GSCOPE_WAIT() \
 204   GL(dl_wait_lookup_done) ()
 205
 206 #endif /* __ASSEMBLER__ */
 207
 208 #endif  /* tls.h */