ports/sysdeps/tile/nptl/tls.h

   1 /* Copyright (C) 2011 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011.
   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   void *feedback_data;
  65   uintptr_t pointer_guard;
  66   uintptr_t stack_guard;
  67   dtv_t *dtv;
  68 } tcbhead_t;
  69
  70 /* This is the size of the initial TCB.  Because our TCB is before the thread
  71    pointer, we don't need this.  */
  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.  Because our TCB is before the thread
  78    pointer, we don't need this.  */
  79 # define TLS_TCB_SIZE           0
  80
  81 /* Alignment requirements for the TCB.  */
  82 # define TLS_TCB_ALIGN          __alignof__ (struct pthread)
  83
  84 /* This is the size we need before TCB - actually, it includes the TCB.  */
  85 # define TLS_PRE_TCB_SIZE \
  86   (sizeof (struct pthread)                                                    \
  87    + ((sizeof (tcbhead_t) + TLS_TCB_ALIGN - 1) & ~(TLS_TCB_ALIGN - 1)))
  88
  89 /* Return the thread descriptor (tp) for the current thread.  */
  90 register void *__thread_pointer asm ("tp");
  91
  92 /* The thread pointer (in hardware register tp) points to the end of
  93    the TCB.  The pthread_descr structure is immediately in front of the TCB.  */
  94 # define TLS_TCB_OFFSET 0
  95
  96 /* Install the dtv pointer.  The pointer passed is to the element with
  97    index -1 which contain the length.  */
  98 # define INSTALL_DTV(tcbp, dtvp) \
  99   (((tcbhead_t *) (tcbp))[-1].dtv = (dtvp) + 1)
 100
 101 /* Install new dtv for current thread.  */
 102 # define INSTALL_NEW_DTV(dtv) (THREAD_DTV() = (dtv))
 103
 104 /* Return dtv of given thread descriptor.  */
 105 # define GET_DTV(tcbp)  (((tcbhead_t *) (tcbp))[-1].dtv)
 106
 107 /* Code to initially initialize the thread pointer (tp).  */
 108 # define TLS_INIT_TP(tcbp, secondcall) \
 109     (__thread_pointer = (char *)(tcbp) + TLS_TCB_OFFSET, NULL)
 110
 111 /* Return the address of the dtv for the current thread.  */
 112 # define THREAD_DTV() \
 113     (((tcbhead_t *) (__thread_pointer - TLS_TCB_OFFSET))[-1].dtv)
 114
 115 /* Return the thread descriptor for the current thread.  */
 116 # define THREAD_SELF \
 117     ((struct pthread *) (__thread_pointer \
 118                          - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE))
 119
 120 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 121 #ifdef __tilegx__
 122 # define DB_THREAD_SELF \
 123   REGISTER (64, 64, REG_TP * 8, - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE)
 124 #else
 125 # define DB_THREAD_SELF \
 126   REGISTER (32, 32, REG_TP * 4, - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE)
 127 #endif
 128
 129 /* Read member of the thread descriptor directly.  */
 130 # define THREAD_GETMEM(descr, member) (descr->member)
 131
 132 /* Same as THREAD_GETMEM, but the member offset can be non-constant.  */
 133 # define THREAD_GETMEM_NC(descr, member, idx) \
 134     (descr->member[idx])
 135
 136 /* Set member of the thread descriptor directly.  */
 137 # define THREAD_SETMEM(descr, member, value) \
 138     (descr->member = (value))
 139
 140 /* Same as THREAD_SETMEM, but the member offset can be non-constant.  */
 141 # define THREAD_SETMEM_NC(descr, member, idx, value) \
 142     (descr->member[idx] = (value))
 143
 144 /* Set the stack guard field in TCB head.  */
 145 # define THREAD_SET_STACK_GUARD(value) \
 146     (((tcbhead_t *) ((char *) __thread_pointer                                \
 147                      - TLS_TCB_OFFSET))[-1].stack_guard = (value))
 148 # define THREAD_COPY_STACK_GUARD(descr) \
 149     (((tcbhead_t *) ((char *) (descr)                                         \
 150                      + TLS_PRE_TCB_SIZE))[-1].stack_guard                     \
 151      = ((tcbhead_t *) ((char *) __thread_pointer                              \
 152                        - TLS_TCB_OFFSET))[-1].stack_guard)
 153
 154 /* Set the pointer guard field in TCB head.  */
 155 # define THREAD_GET_POINTER_GUARD() \
 156     (((tcbhead_t *) ((char *) __thread_pointer                                \
 157                      - TLS_TCB_OFFSET))[-1].pointer_guard)
 158 # define THREAD_SET_POINTER_GUARD(value) \
 159     (THREAD_GET_POINTER_GUARD () = (value))
 160 # define THREAD_COPY_POINTER_GUARD(descr) \
 161     (((tcbhead_t *) ((char *) (descr)                                         \
 162                      + TLS_PRE_TCB_SIZE))[-1].pointer_guard                   \
 163      = THREAD_GET_POINTER_GUARD())
 164
 165 /* l_tls_offset == 0 is perfectly valid on Tile, so we have to use some
 166    different value to mean unset l_tls_offset.  */
 167 # define NO_TLS_OFFSET          -1
 168
 169 /* Get and set the global scope generation counter in struct pthread.  */
 170 #define THREAD_GSCOPE_FLAG_UNUSED 0
 171 #define THREAD_GSCOPE_FLAG_USED   1
 172 #define THREAD_GSCOPE_FLAG_WAIT   2
 173 #define THREAD_GSCOPE_RESET_FLAG() \
 174   do                                                                         \
 175     { int __res                                                              \
 176         = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,             \
 177                                THREAD_GSCOPE_FLAG_UNUSED);                   \
 178       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                  \
 179         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);   \
 180     }                                                                        \
 181   while (0)
 182 #define THREAD_GSCOPE_SET_FLAG() \
 183   do                                                                         \
 184     {                                                                        \
 185       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;             \
 186       atomic_write_barrier ();                                               \
 187     }                                                                        \
 188   while (0)
 189 #define THREAD_GSCOPE_WAIT() \
 190   GL(dl_wait_lookup_done) ()
 191
 192 #endif /* __ASSEMBLER__ */
 193
 194 #endif /* tls.h */