sysdeps/m68k/nptl/tls.h

   1 /* Definition for thread-local data handling.  NPTL/m68k version.
   2    Copyright (C) 2010-2015 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, see
  18    <http://www.gnu.org/licenses/>.  */
  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 #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 # define TLS_TCB_AT_TP  0
  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)                                              \
 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 # define TLS_DEFINE_INIT_TP(tp, pd) \
 116   void *tp = (void *) (pd) + TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE
 117
 118 extern void * __m68k_read_tp (void);
 119
 120 /* Return the address of the dtv for the current thread.  */
 121 # define THREAD_DTV() \
 122   (((tcbhead_t *) (__m68k_read_tp () - TLS_TCB_OFFSET))[-1].dtv)
 123
 124 /* Return the thread descriptor for the current thread.  */
 125 # define THREAD_SELF \
 126   ((struct pthread *) (__m68k_read_tp () - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE))
 127
 128 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 129 # define DB_THREAD_SELF \
 130   CONST_THREAD_AREA (32, TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE)
 131
 132 /* Access to data in the thread descriptor is easy.  */
 133 # define THREAD_GETMEM(descr, member) \
 134   descr->member
 135 # define THREAD_GETMEM_NC(descr, member, idx) \
 136   descr->member[idx]
 137 # define THREAD_SETMEM(descr, member, value) \
 138   descr->member = (value)
 139 # define THREAD_SETMEM_NC(descr, member, idx, value) \
 140   descr->member[idx] = (value)
 141
 142 /* l_tls_offset == 0 is perfectly valid on M68K, so we have to use some
 143    different value to mean unset l_tls_offset.  */
 144 # define NO_TLS_OFFSET          -1
 145
 146 /* Get and set the global scope generation counter in struct pthread.  */
 147 #define THREAD_GSCOPE_FLAG_UNUSED 0
 148 #define THREAD_GSCOPE_FLAG_USED   1
 149 #define THREAD_GSCOPE_FLAG_WAIT   2
 150 #define THREAD_GSCOPE_RESET_FLAG()                                      \
 151   do                                                                    \
 152     { int __res                                                         \
 153         = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,        \
 154                                THREAD_GSCOPE_FLAG_UNUSED);              \
 155       if (__res == THREAD_GSCOPE_FLAG_WAIT)                             \
 156         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE); \
 157     }                                                                   \
 158   while (0)
 159 #define THREAD_GSCOPE_SET_FLAG()                                        \
 160   do                                                                    \
 161     {                                                                   \
 162       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;        \
 163       atomic_write_barrier ();                                          \
 164     }                                                                   \
 165   while (0)
 166 #define THREAD_GSCOPE_WAIT() \
 167   GL(dl_wait_lookup_done) ()
 168
 169 #endif /* __ASSEMBLER__ */
 170
 171 #endif  /* tls.h */