nptl/sysdeps/s390/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 /* Get the thread descriptor definition.  */
  77 # include <nptl/descr.h>
  78
  79 /* This is the size of the initial TCB.  Can't be just sizeof (tcbhead_t),
  80    because NPTL getpid, __libc_alloca_cutoff etc. need (almost) the whole
  81    struct pthread even when not linked with -lpthread.  */
  82 # define TLS_INIT_TCB_SIZE sizeof (struct pthread)
  83
  84 /* Alignment requirements for the initial TCB.  */
  85 # define TLS_INIT_TCB_ALIGN __alignof__ (struct pthread)
  86
  87 /* This is the size of the TCB.  */
  88 # define TLS_TCB_SIZE sizeof (struct pthread)
  89
  90 /* Alignment requirements for the TCB.  */
  91 # define TLS_TCB_ALIGN __alignof__ (struct pthread)
  92
  93 /* The TCB can have any size and the memory following the address the
  94    thread pointer points to is unspecified.  Allocate the TCB there.  */
  95 # define TLS_TCB_AT_TP  1
  96
  97
  98 /* Install the dtv pointer.  The pointer passed is to the element with
  99    index -1 which contain the length.  */
 100 #  define INSTALL_DTV(descr, dtvp) \
 101   ((tcbhead_t *) (descr))->dtv = (dtvp) + 1
 102
 103 /* Install new dtv for current thread.  */
 104 #  define INSTALL_NEW_DTV(dtv) \
 105   (((tcbhead_t *) __builtin_thread_pointer ())->dtv = (dtv))
 106
 107 /* Return dtv of given thread descriptor.  */
 108 #  define GET_DTV(descr) \
 109   (((tcbhead_t *) (descr))->dtv)
 110
 111 #if defined NEED_DL_SYSINFO && defined SHARED
 112 # define INIT_SYSINFO \
 113   _head->sysinfo = GLRO(dl_sysinfo)
 114 #else
 115 # define INIT_SYSINFO
 116 #endif
 117
 118 /* Code to initially initialize the thread pointer.  This might need
 119    special attention since 'errno' is not yet available and if the
 120    operation can cause a failure 'errno' must not be touched.  */
 121 # define TLS_INIT_TP(thrdescr, secondcall) \
 122   ({ void *_thrdescr = (thrdescr);                                            \
 123      tcbhead_t *_head = _thrdescr;                                            \
 124                                                                               \
 125      _head->tcb = _thrdescr;                                                  \
 126      /* For now the thread descriptor is at the same address.  */             \
 127      _head->self = _thrdescr;                                                 \
 128      /* New syscall handling support.  */                                     \
 129      INIT_SYSINFO;                                                            \
 130                                                                               \
 131     __builtin_set_thread_pointer (_thrdescr);                                 \
 132     NULL;                                                                     \
 133   })
 134
 135 /* Return the address of the dtv for the current thread.  */
 136 #  define THREAD_DTV() \
 137   (((tcbhead_t *) __builtin_thread_pointer ())->dtv)
 138
 139 /* Return the thread descriptor for the current thread.  */
 140 # define THREAD_SELF ((struct pthread *) __builtin_thread_pointer ())
 141
 142 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 143 # define DB_THREAD_SELF REGISTER (32, 32, 18 * 4, 0) \
 144                         REGISTER (64, __WORDSIZE, 18 * 8, 0)
 145
 146 /* Access to data in the thread descriptor is easy.  */
 147 #define THREAD_GETMEM(descr, member) \
 148   descr->member
 149 #define THREAD_GETMEM_NC(descr, member, idx) \
 150   descr->member[idx]
 151 #define THREAD_SETMEM(descr, member, value) \
 152   descr->member = (value)
 153 #define THREAD_SETMEM_NC(descr, member, idx, value) \
 154   descr->member[idx] = (value)
 155
 156 /* Set the stack guard field in TCB head.  */
 157 #define THREAD_SET_STACK_GUARD(value) \
 158   do                                                                          \
 159    {                                                                          \
 160      __asm __volatile ("" : : : "a0", "a1");                                  \
 161      THREAD_SETMEM (THREAD_SELF, header.stack_guard, value);                  \
 162    }                                                                          \
 163   while (0)
 164 #define THREAD_COPY_STACK_GUARD(descr) \
 165   ((descr)->header.stack_guard                                                \
 166    = THREAD_GETMEM (THREAD_SELF, header.stack_guard))
 167
 168 /* s390 doesn't have HP_TIMING_*, so for the time being
 169    use stack_guard as pointer_guard.  */
 170 #define THREAD_GET_POINTER_GUARD() \
 171   THREAD_GETMEM (THREAD_SELF, header.stack_guard)
 172 #define THREAD_SET_POINTER_GUARD(value)
 173 #define THREAD_COPY_POINTER_GUARD(descr)
 174
 175 /* Get and set the global scope generation counter in struct pthread.  */
 176 #define THREAD_GSCOPE_FLAG_UNUSED 0
 177 #define THREAD_GSCOPE_FLAG_USED   1
 178 #define THREAD_GSCOPE_FLAG_WAIT   2
 179 #define THREAD_GSCOPE_RESET_FLAG() \
 180   do                                                                         \
 181     { int __res                                                              \
 182         = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,             \
 183                                THREAD_GSCOPE_FLAG_UNUSED);                   \
 184       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                  \
 185         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);   \
 186     }                                                                        \
 187   while (0)
 188 #define THREAD_GSCOPE_SET_FLAG() \
 189   do                                                                         \
 190     {                                                                        \
 191       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;             \
 192       atomic_write_barrier ();                                               \
 193     }                                                                        \
 194   while (0)
 195 #define THREAD_GSCOPE_WAIT() \
 196   GL(dl_wait_lookup_done) ()
 197
 198 #endif /* __ASSEMBLER__ */
 199
 200 #endif  /* tls.h */