sysdeps/s390/nptl/tls.h

   1 /* Definition for thread-local data handling.  NPTL/s390 version.
   2    Copyright (C) 2003-2014 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 #ifndef __ASSEMBLER__
  24 # include <stdbool.h>
  25 # include <stddef.h>
  26 # include <stdint.h>
  27 # include <stdlib.h>
  28 # include <list.h>
  29 # include <kernel-features.h>
  30
  31
  32 /* Type for the dtv.  */
  33 typedef union dtv
  34 {
  35   size_t counter;
  36   struct
  37   {
  38     void *val;
  39     bool is_static;
  40   } pointer;
  41 } dtv_t;
  42
  43
  44 typedef struct
  45 {
  46   void *tcb;            /* Pointer to the TCB.  Not necessary the
  47                            thread descriptor used by libpthread.  */
  48   dtv_t *dtv;
  49   void *self;           /* Pointer to the thread descriptor.  */
  50   int multiple_threads;
  51   uintptr_t sysinfo;
  52   uintptr_t stack_guard;
  53   int gscope_flag;
  54 #ifndef __ASSUME_PRIVATE_FUTEX
  55   int private_futex;
  56 #endif
  57 } tcbhead_t;
  58
  59 # ifndef __s390x__
  60 #  define TLS_MULTIPLE_THREADS_IN_TCB 1
  61 # endif
  62
  63 #else /* __ASSEMBLER__ */
  64 # include <tcb-offsets.h>
  65 #endif
  66
  67
  68 /* Alignment requirement for the stack.  For IA-32 this is governed by
  69    the SSE memory functions.  */
  70 #define STACK_ALIGN     16
  71
  72 #ifndef __ASSEMBLER__
  73 /* Get system call information.  */
  74 # include <sysdep.h>
  75
  76 /* This is the size of the initial TCB.  Can't be just sizeof (tcbhead_t),
  77    because NPTL getpid, __libc_alloca_cutoff etc. need (almost) the whole
  78    struct pthread even when not linked with -lpthread.  */
  79 # define TLS_INIT_TCB_SIZE sizeof (struct pthread)
  80
  81 /* Alignment requirements for the initial TCB.  */
  82 # define TLS_INIT_TCB_ALIGN __alignof__ (struct pthread)
  83
  84 /* This is the size of the TCB.  */
  85 # define TLS_TCB_SIZE sizeof (struct pthread)
  86
  87 /* Alignment requirements for the TCB.  */
  88 # define TLS_TCB_ALIGN __alignof__ (struct pthread)
  89
  90 /* The TCB can have any size and the memory following the address the
  91    thread pointer points to is unspecified.  Allocate the TCB there.  */
  92 # define TLS_TCB_AT_TP  1
  93 # define TLS_DTV_AT_TP  0
  94
  95 /* Get the thread descriptor definition.  */
  96 # include <nptl/descr.h>
  97
  98
  99 /* Install the dtv pointer.  The pointer passed is to the element with
 100    index -1 which contain the length.  */
 101 #  define INSTALL_DTV(descr, dtvp) \
 102   ((tcbhead_t *) (descr))->dtv = (dtvp) + 1
 103
 104 /* Install new dtv for current thread.  */
 105 #  define INSTALL_NEW_DTV(dtv) \
 106   (((tcbhead_t *) __builtin_thread_pointer ())->dtv = (dtv))
 107
 108 /* Return dtv of given thread descriptor.  */
 109 #  define GET_DTV(descr) \
 110   (((tcbhead_t *) (descr))->dtv)
 111
 112 #if defined NEED_DL_SYSINFO && defined SHARED
 113 # define INIT_SYSINFO \
 114   _head->sysinfo = GLRO(dl_sysinfo)
 115 #else
 116 # define INIT_SYSINFO
 117 #endif
 118
 119 /* Code to initially initialize the thread pointer.  This might need
 120    special attention since 'errno' is not yet available and if the
 121    operation can cause a failure 'errno' must not be touched.  */
 122 # define TLS_INIT_TP(thrdescr) \
 123   ({ void *_thrdescr = (thrdescr);                                            \
 124      tcbhead_t *_head = _thrdescr;                                            \
 125                                                                               \
 126      _head->tcb = _thrdescr;                                                  \
 127      /* For now the thread descriptor is at the same address.  */             \
 128      _head->self = _thrdescr;                                                 \
 129      /* New syscall handling support.  */                                     \
 130      INIT_SYSINFO;                                                            \
 131                                                                               \
 132     __builtin_set_thread_pointer (_thrdescr);                                 \
 133     NULL;                                                                     \
 134   })
 135
 136 /* Value passed to 'clone' for initialization of the thread register.  */
 137 # define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd)
 138
 139 /* Return the address of the dtv for the current thread.  */
 140 #  define THREAD_DTV() \
 141   (((tcbhead_t *) __builtin_thread_pointer ())->dtv)
 142
 143 /* Return the thread descriptor for the current thread.  */
 144 # define THREAD_SELF ((struct pthread *) __builtin_thread_pointer ())
 145
 146 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 147 # define DB_THREAD_SELF REGISTER (32, 32, 18 * 4, 0) \
 148                         REGISTER (64, __WORDSIZE, 18 * 8, 0)
 149
 150 /* Access to data in the thread descriptor is easy.  */
 151 #define THREAD_GETMEM(descr, member) \
 152   descr->member
 153 #define THREAD_GETMEM_NC(descr, member, idx) \
 154   descr->member[idx]
 155 #define THREAD_SETMEM(descr, member, value) \
 156   descr->member = (value)
 157 #define THREAD_SETMEM_NC(descr, member, idx, value) \
 158   descr->member[idx] = (value)
 159
 160 /* Set the stack guard field in TCB head.  */
 161 #define THREAD_SET_STACK_GUARD(value) \
 162   do                                                                          \
 163    {                                                                          \
 164      __asm __volatile ("" : : : "a0", "a1");                                  \
 165      THREAD_SETMEM (THREAD_SELF, header.stack_guard, value);                  \
 166    }                                                                          \
 167   while (0)
 168 #define THREAD_COPY_STACK_GUARD(descr) \
 169   ((descr)->header.stack_guard                                                \
 170    = THREAD_GETMEM (THREAD_SELF, header.stack_guard))
 171
 172 /* s390 doesn't have HP_TIMING_*, so for the time being
 173    use stack_guard as pointer_guard.  */
 174 #define THREAD_GET_POINTER_GUARD() \
 175   THREAD_GETMEM (THREAD_SELF, header.stack_guard)
 176 #define THREAD_SET_POINTER_GUARD(value) ((void) (value))
 177 #define THREAD_COPY_POINTER_GUARD(descr)
 178
 179 /* Get and set the global scope generation counter in struct pthread.  */
 180 #define THREAD_GSCOPE_FLAG_UNUSED 0
 181 #define THREAD_GSCOPE_FLAG_USED   1
 182 #define THREAD_GSCOPE_FLAG_WAIT   2
 183 #define THREAD_GSCOPE_RESET_FLAG() \
 184   do                                                                         \
 185     { int __res                                                              \
 186         = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,             \
 187                                THREAD_GSCOPE_FLAG_UNUSED);                   \
 188       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                  \
 189         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);   \
 190     }                                                                        \
 191   while (0)
 192 #define THREAD_GSCOPE_SET_FLAG() \
 193   do                                                                         \
 194     {                                                                        \
 195       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;             \
 196       atomic_write_barrier ();                                               \
 197     }                                                                        \
 198   while (0)
 199 #define THREAD_GSCOPE_WAIT() \
 200   GL(dl_wait_lookup_done) ()
 201
 202 #endif /* __ASSEMBLER__ */
 203
 204 #endif  /* tls.h */