libpthread/nptl/sysdeps/m68k/tls.h

   1 /* Definition for thread-local data handling.  NPTL/m68k version.
   2    Copyright (C) 2010-2017 Free Software Foundation, Inc.
   3    Contributed by Maxim Kuvyrkov <maxim@codesourcery.com>, 2010.
   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 #ifndef __ASSEMBLER__
  23 # include <stdbool.h>
  24 # include <stddef.h>
  25 # include <stdint.h>
  26
  27 /* Type for the dtv.  */
  28 typedef union dtv
  29 {
  30   size_t counter;
  31   struct
  32   {
  33     void *val;
  34     bool is_static;
  35   } pointer;
  36 } dtv_t;
  37
  38 /* Value used for dtv entries for which the allocation is delayed.  */
  39 #define TLS_DTV_UNALLOCATED ((void *) -1l)
  40
  41 #else /* __ASSEMBLER__ */
  42 # include <tcb-offsets.h>
  43 #endif /* __ASSEMBLER__ */
  44
  45 /* We require TLS support in the tools.  */
  46 #define HAVE_TLS_SUPPORT                1
  47 #define HAVE_TLS_MODEL_ATTRIBUTE        1
  48 #define HAVE___THREAD                   1
  49
  50 /* Signal that TLS support is available.  */
  51 #define USE_TLS 1
  52
  53 #ifndef __ASSEMBLER__
  54
  55 /* Get system call information.  */
  56 # include <sysdep.h>
  57
  58 /* The TP points to the start of the thread blocks.  */
  59 # define TLS_DTV_AT_TP  1
  60
  61 /* Get the thread descriptor definition.  */
  62 # include <../../descr.h>
  63
  64 typedef struct
  65 {
  66   dtv_t *dtv;
  67   void *private;
  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 /* The thread pointer (TP) points to the end of the
  90    TCB + 0x7000, as for PowerPC and MIPS.  This implies that TCB address is
  91    TP - 0x7000.  As we define TLS_DTV_AT_TP we can
  92    assume that the pthread struct is allocated immediately ahead of the
  93    TCB.  This implies that the pthread_descr address is
  94    TP - (TLS_PRE_TCB_SIZE + 0x7000).  */
  95 # define TLS_TCB_OFFSET 0x7000
  96
  97 /* Install the dtv pointer.  The pointer passed is to the element with
  98    index -1 which contain the length.  */
  99 # define INSTALL_DTV(tcbp, dtvp) \
 100   ((tcbhead_t *) (tcbp))[-1].dtv = dtvp + 1
 101
 102 /* Install new dtv for current thread.  */
 103 # define INSTALL_NEW_DTV(dtv) \
 104   (THREAD_DTV () = (dtv))
 105
 106 /* Return dtv of given thread descriptor.  */
 107 # define GET_DTV(tcbp) \
 108   (((tcbhead_t *) (tcbp))[-1].dtv)
 109
 110 /* Code to initially initialize the thread pointer.  This might need
 111    special attention since 'errno' is not yet available and if the
 112    operation can cause a failure 'errno' must not be touched.  */
 113 # define TLS_INIT_TP(tcbp, secondcall)                                  \
 114   ({                                                                    \
 115     INTERNAL_SYSCALL_DECL (err);                                        \
 116     int result_var;                                                     \
 117     result_var = INTERNAL_SYSCALL (set_thread_area, err, 1,             \
 118                             ((void *) (tcbp)) + TLS_TCB_OFFSET);        \
 119     INTERNAL_SYSCALL_ERROR_P (result_var, err)                          \
 120       ? "unknown error" : NULL; })
 121
 122 # define TLS_DEFINE_INIT_TP(tp, pd) \
 123   void *tp = (void *) (pd) + TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE
 124
 125 extern void * __m68k_read_tp (void);
 126
 127 /* Return the address of the dtv for the current thread.  */
 128 # define THREAD_DTV() \
 129   (((tcbhead_t *) (__m68k_read_tp () - TLS_TCB_OFFSET))[-1].dtv)
 130
 131 /* Return the thread descriptor for the current thread.  */
 132 # define THREAD_SELF \
 133   ((struct pthread *) (__m68k_read_tp () - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE))
 134
 135 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 136 # define DB_THREAD_SELF \
 137   CONST_THREAD_AREA (32, TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE)
 138
 139 /* Access to data in the thread descriptor is easy.  */
 140 # define THREAD_GETMEM(descr, member) \
 141   descr->member
 142 # define THREAD_GETMEM_NC(descr, member, idx) \
 143   descr->member[idx]
 144 # define THREAD_SETMEM(descr, member, value) \
 145   descr->member = (value)
 146 # define THREAD_SETMEM_NC(descr, member, idx, value) \
 147   descr->member[idx] = (value)
 148
 149 /* l_tls_offset == 0 is perfectly valid on M68K, so we have to use some
 150    different value to mean unset l_tls_offset.  */
 151 # define NO_TLS_OFFSET          -1
 152
 153 /* Get and set the global scope generation counter in struct pthread.  */
 154 #define THREAD_GSCOPE_FLAG_UNUSED 0
 155 #define THREAD_GSCOPE_FLAG_USED   1
 156 #define THREAD_GSCOPE_FLAG_WAIT   2
 157 #define THREAD_GSCOPE_RESET_FLAG()                                      \
 158   do                                                                    \
 159     { int __res                                                         \
 160         = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,        \
 161                                THREAD_GSCOPE_FLAG_UNUSED);              \
 162       if (__res == THREAD_GSCOPE_FLAG_WAIT)                             \
 163         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE); \
 164     }                                                                   \
 165   while (0)
 166 #define THREAD_GSCOPE_SET_FLAG()                                        \
 167   do                                                                    \
 168     {                                                                   \
 169       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;        \
 170       atomic_write_barrier ();                                          \
 171     }                                                                   \
 172   while (0)
 173 #define THREAD_GSCOPE_WAIT() \
 174   GL(dl_wait_lookup_done) ()
 175
 176 #endif /* __ASSEMBLER__ */
 177
 178 #endif  /* tls.h */