nptl/sysdeps/powerpc/tls.h

   1 /* Definition for thread-local data handling.  NPTL/PowerPC version.
   2    Copyright (C) 2003, 2005, 2006, 2007, 2011 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    <http://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
  29 /* Type for the dtv.  */
  30 typedef union dtv
  31 {
  32   size_t counter;
  33   struct
  34   {
  35     void *val;
  36     bool is_static;
  37   } pointer;
  38 } dtv_t;
  39
  40 #else /* __ASSEMBLER__ */
  41 # include <tcb-offsets.h>
  42 #endif /* __ASSEMBLER__ */
  43
  44
  45 #ifndef __ASSEMBLER__
  46
  47 /* Get system call information.  */
  48 # include <sysdep.h>
  49
  50 /* The TP points to the start of the thread blocks.  */
  51 # define TLS_DTV_AT_TP  1
  52
  53 /* We use the multiple_threads field in the pthread struct */
  54 #define TLS_MULTIPLE_THREADS_IN_TCB     1
  55
  56 /* Get the thread descriptor definition.  */
  57 # include <nptl/descr.h>
  58
  59 /* The stack_guard is accessed directly by GCC -fstack-protector code,
  60    so it is a part of public ABI.  The dtv and pointer_guard fields
  61    are private.  */
  62 typedef struct
  63 {
  64   uintptr_t pointer_guard;
  65   uintptr_t stack_guard;
  66   dtv_t *dtv;
  67 } tcbhead_t;
  68
  69 /* This is the size of the initial TCB.  */
  70 # define TLS_INIT_TCB_SIZE      0
  71
  72 /* Alignment requirements for the initial TCB.  */
  73 # define TLS_INIT_TCB_ALIGN     __alignof__ (struct pthread)
  74
  75 /* This is the size of the TCB.  */
  76 # define TLS_TCB_SIZE           0
  77
  78 /* Alignment requirements for the TCB.  */
  79 # define TLS_TCB_ALIGN          __alignof__ (struct pthread)
  80
  81 /* This is the size we need before TCB.  */
  82 # define TLS_PRE_TCB_SIZE \
  83   (sizeof (struct pthread)                                                    \
  84    + ((sizeof (tcbhead_t) + TLS_TCB_ALIGN - 1) & ~(TLS_TCB_ALIGN - 1)))
  85
  86 # ifndef __powerpc64__
  87 /* Register r2 (tp) is reserved by the ABI as "thread pointer". */
  88 register void *__thread_register __asm__ ("r2");
  89 #  define PT_THREAD_POINTER PT_R2
  90 # else
  91 /* Register r13 (tp) is reserved by the ABI as "thread pointer". */
  92 register void *__thread_register __asm__ ("r13");
  93 #  define PT_THREAD_POINTER PT_R13
  94 # endif
  95
  96 /* The following assumes that TP (R2 or R13) points to the end of the
  97    TCB + 0x7000 (per the ABI).  This implies that TCB address is
  98    TP - 0x7000.  As we define TLS_DTV_AT_TP we can
  99    assume that the pthread struct is allocated immediately ahead of the
 100    TCB.  This implies that the pthread_descr address is
 101    TP - (TLS_PRE_TCB_SIZE + 0x7000).  */
 102 # define TLS_TCB_OFFSET 0x7000
 103
 104 /* Install the dtv pointer.  The pointer passed is to the element with
 105    index -1 which contain the length.  */
 106 # define INSTALL_DTV(tcbp, dtvp) \
 107   ((tcbhead_t *) (tcbp))[-1].dtv = dtvp + 1
 108
 109 /* Install new dtv for current thread.  */
 110 # define INSTALL_NEW_DTV(dtv) (THREAD_DTV() = (dtv))
 111
 112 /* Return dtv of given thread descriptor.  */
 113 # define GET_DTV(tcbp)  (((tcbhead_t *) (tcbp))[-1].dtv)
 114
 115 /* Code to initially initialize the thread pointer.  This might need
 116    special attention since 'errno' is not yet available and if the
 117    operation can cause a failure 'errno' must not be touched.  */
 118 # define TLS_INIT_TP(tcbp, secondcall) \
 119     (__thread_register = (void *) (tcbp) + TLS_TCB_OFFSET, NULL)
 120
 121 /* Return the address of the dtv for the current thread.  */
 122 # define THREAD_DTV() \
 123     (((tcbhead_t *) (__thread_register - TLS_TCB_OFFSET))[-1].dtv)
 124
 125 /* Return the thread descriptor for the current thread.  */
 126 # define THREAD_SELF \
 127     ((struct pthread *) (__thread_register \
 128                          - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE))
 129
 130 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 131 # define DB_THREAD_SELF                                                       \
 132   REGISTER (32, 32, PT_THREAD_POINTER * 4,                                    \
 133             - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE)                              \
 134   REGISTER (64, 64, PT_THREAD_POINTER * 8,                                    \
 135             - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE)
 136
 137 /* Read member of the thread descriptor directly.  */
 138 # define THREAD_GETMEM(descr, member) ((void)(descr), (THREAD_SELF)->member)
 139
 140 /* Same as THREAD_GETMEM, but the member offset can be non-constant.  */
 141 # define THREAD_GETMEM_NC(descr, member, idx) \
 142     ((void)(descr), (THREAD_SELF)->member[idx])
 143
 144 /* Set member of the thread descriptor directly.  */
 145 # define THREAD_SETMEM(descr, member, value) \
 146     ((void)(descr), (THREAD_SELF)->member = (value))
 147
 148 /* Same as THREAD_SETMEM, but the member offset can be non-constant.  */
 149 # define THREAD_SETMEM_NC(descr, member, idx, value) \
 150     ((void)(descr), (THREAD_SELF)->member[idx] = (value))
 151
 152 /* Set the stack guard field in TCB head.  */
 153 # define THREAD_SET_STACK_GUARD(value) \
 154     (((tcbhead_t *) ((char *) __thread_register                               \
 155                      - TLS_TCB_OFFSET))[-1].stack_guard = (value))
 156 # define THREAD_COPY_STACK_GUARD(descr) \
 157     (((tcbhead_t *) ((char *) (descr)                                         \
 158                      + TLS_PRE_TCB_SIZE))[-1].stack_guard                     \
 159      = ((tcbhead_t *) ((char *) __thread_register                             \
 160                        - TLS_TCB_OFFSET))[-1].stack_guard)
 161
 162 /* Set the stack guard field in TCB head.  */
 163 # define THREAD_GET_POINTER_GUARD() \
 164     (((tcbhead_t *) ((char *) __thread_register                               \
 165                      - TLS_TCB_OFFSET))[-1].pointer_guard)
 166 # define THREAD_SET_POINTER_GUARD(value) \
 167     (THREAD_GET_POINTER_GUARD () = (value))
 168 # define THREAD_COPY_POINTER_GUARD(descr) \
 169     (((tcbhead_t *) ((char *) (descr)                                         \
 170                      + TLS_PRE_TCB_SIZE))[-1].pointer_guard                   \
 171      = THREAD_GET_POINTER_GUARD())
 172
 173 /* l_tls_offset == 0 is perfectly valid on PPC, so we have to use some
 174    different value to mean unset l_tls_offset.  */
 175 # define NO_TLS_OFFSET          -1
 176
 177 /* Get and set the global scope generation counter in struct pthread.  */
 178 #define THREAD_GSCOPE_FLAG_UNUSED 0
 179 #define THREAD_GSCOPE_FLAG_USED   1
 180 #define THREAD_GSCOPE_FLAG_WAIT   2
 181 #define THREAD_GSCOPE_RESET_FLAG() \
 182   do                                                                         \
 183     { int __res                                                              \
 184         = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,             \
 185                                THREAD_GSCOPE_FLAG_UNUSED);                   \
 186       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                  \
 187         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);   \
 188     }                                                                        \
 189   while (0)
 190 #define THREAD_GSCOPE_SET_FLAG() \
 191   do                                                                         \
 192     {                                                                        \
 193       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;             \
 194       atomic_write_barrier ();                                               \
 195     }                                                                        \
 196   while (0)
 197 #define THREAD_GSCOPE_WAIT() \
 198   GL(dl_wait_lookup_done) ()
 199
 200 #endif /* __ASSEMBLER__ */
 201
 202 #endif  /* tls.h */