sysdeps/m68k/nptl/tls.h

   1 /* Definition for thread-local data handling.  NPTL/m68k version.
   2    Copyright (C) 2010 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Maxim Kuvyrkov <maxim@codesourcery.com>, 2010.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #ifndef _TLS_H
  22 #define _TLS_H  1
  23
  24 #include <dl-sysdep.h>
  25
  26 #ifndef __ASSEMBLER__
  27 # include <stdbool.h>
  28 # include <stddef.h>
  29 # include <stdint.h>
  30
  31 /* Type for the dtv.  */
  32 typedef union dtv
  33 {
  34   size_t counter;
  35   struct
  36   {
  37     void *val;
  38     bool is_static;
  39   } pointer;
  40 } dtv_t;
  41
  42 #else /* __ASSEMBLER__ */
  43 # include <tcb-offsets.h>
  44 #endif /* __ASSEMBLER__ */
  45
  46 #ifndef __ASSEMBLER__
  47
  48 /* Get system call information.  */
  49 # include <sysdep.h>
  50
  51 /* The TP points to the start of the thread blocks.  */
  52 # define TLS_DTV_AT_TP  1
  53
  54 /* Get the thread descriptor definition.  */
  55 # include <nptl/descr.h>
  56
  57 typedef struct
  58 {
  59   dtv_t *dtv;
  60   void *private;
  61 } tcbhead_t;
  62
  63 /* This is the size of the initial TCB.  Because our TCB is before the thread
  64    pointer, we don't need this.  */
  65 # define TLS_INIT_TCB_SIZE      0
  66
  67 /* Alignment requirements for the initial TCB.  */
  68 # define TLS_INIT_TCB_ALIGN     __alignof__ (struct pthread)
  69
  70 /* This is the size of the TCB.  Because our TCB is before the thread
  71    pointer, we don't need this.  */
  72 # define TLS_TCB_SIZE           0
  73
  74 /* Alignment requirements for the TCB.  */
  75 # define TLS_TCB_ALIGN          __alignof__ (struct pthread)
  76
  77 /* This is the size we need before TCB - actually, it includes the TCB.  */
  78 # define TLS_PRE_TCB_SIZE                                               \
  79   (sizeof (struct pthread)                                              \
  80    + ((sizeof (tcbhead_t) + TLS_TCB_ALIGN - 1) & ~(TLS_TCB_ALIGN - 1)))
  81
  82 /* The thread pointer (TP) points to the end of the
  83    TCB + 0x7000, as for PowerPC and MIPS.  This implies that TCB address is
  84    TP - 0x7000.  As we define TLS_DTV_AT_TP we can
  85    assume that the pthread struct is allocated immediately ahead of the
  86    TCB.  This implies that the pthread_descr address is
  87    TP - (TLS_PRE_TCB_SIZE + 0x7000).  */
  88 # define TLS_TCB_OFFSET 0x7000
  89
  90 /* Install the dtv pointer.  The pointer passed is to the element with
  91    index -1 which contain the length.  */
  92 # define INSTALL_DTV(tcbp, dtvp) \
  93   ((tcbhead_t *) (tcbp))[-1].dtv = dtvp + 1
  94
  95 /* Install new dtv for current thread.  */
  96 # define INSTALL_NEW_DTV(dtv) \
  97   (THREAD_DTV () = (dtv))
  98
  99 /* Return dtv of given thread descriptor.  */
 100 # define GET_DTV(tcbp) \
 101   (((tcbhead_t *) (tcbp))[-1].dtv)
 102
 103 /* Code to initially initialize the thread pointer.  This might need
 104    special attention since 'errno' is not yet available and if the
 105    operation can cause a failure 'errno' must not be touched.  */
 106 # define TLS_INIT_TP(tcbp, secondcall)                                  \
 107   ({                                                                    \
 108     INTERNAL_SYSCALL_DECL (err);                                        \
 109     int _sys_result;                                                    \
 110                                                                         \
 111     _sys_result = INTERNAL_SYSCALL (set_thread_area, err, 1,            \
 112                                     ((void *) (tcbp)) + TLS_TCB_OFFSET); \
 113     INTERNAL_SYSCALL_ERROR_P (_sys_result, err) ? "unknown error" : NULL; })
 114
 115 extern void * __m68k_read_tp (void);
 116
 117 /* Return the address of the dtv for the current thread.  */
 118 # define THREAD_DTV() \
 119   (((tcbhead_t *) (__m68k_read_tp () - TLS_TCB_OFFSET))[-1].dtv)
 120
 121 /* Return the thread descriptor for the current thread.  */
 122 # define THREAD_SELF \
 123   ((struct pthread *) (__m68k_read_tp () - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE))
 124
 125 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 126 # define DB_THREAD_SELF \
 127   CONST_THREAD_AREA (32, TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE)
 128
 129 /* Access to data in the thread descriptor is easy.  */
 130 # define THREAD_GETMEM(descr, member) \
 131   descr->member
 132 # define THREAD_GETMEM_NC(descr, member, idx) \
 133   descr->member[idx]
 134 # define THREAD_SETMEM(descr, member, value) \
 135   descr->member = (value)
 136 # define THREAD_SETMEM_NC(descr, member, idx, value) \
 137   descr->member[idx] = (value)
 138
 139 /* l_tls_offset == 0 is perfectly valid on M68K, so we have to use some
 140    different value to mean unset l_tls_offset.  */
 141 # define NO_TLS_OFFSET          -1
 142
 143 /* Get and set the global scope generation counter in struct pthread.  */
 144 #define THREAD_GSCOPE_FLAG_UNUSED 0
 145 #define THREAD_GSCOPE_FLAG_USED   1
 146 #define THREAD_GSCOPE_FLAG_WAIT   2
 147 #define THREAD_GSCOPE_RESET_FLAG()                                      \
 148   do                                                                    \
 149     { int __res                                                         \
 150         = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,        \
 151                                THREAD_GSCOPE_FLAG_UNUSED);              \
 152       if (__res == THREAD_GSCOPE_FLAG_WAIT)                             \
 153         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE); \
 154     }                                                                   \
 155   while (0)
 156 #define THREAD_GSCOPE_SET_FLAG()                                        \
 157   do                                                                    \
 158     {                                                                   \
 159       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;        \
 160       atomic_write_barrier ();                                          \
 161     }                                                                   \
 162   while (0)
 163 #define THREAD_GSCOPE_WAIT() \
 164   GL(dl_wait_lookup_done) ()
 165
 166 #endif /* __ASSEMBLER__ */
 167
 168 #endif  /* tls.h */