nptl/sysdeps/s390/tls.h

   1 /* Definition for thread-local data handling.  NPTL/s390 version.
   2    Copyright (C) 2003, 2004, 2005, 2006, 2007 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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #ifndef _TLS_H
  21 #define _TLS_H  1
  22
  23 #include <dl-sysdep.h>
  24 #ifndef __ASSEMBLER__
  25 # include <stdbool.h>
  26 # include <stddef.h>
  27 # include <stdint.h>
  28 # include <stdlib.h>
  29 # include <list.h>
  30 # include <kernel-features.h>
  31
  32
  33 /* Type for the dtv.  */
  34 typedef union dtv
  35 {
  36   size_t counter;
  37   struct
  38   {
  39     void *val;
  40     bool is_static;
  41   } pointer;
  42 } dtv_t;
  43
  44
  45 typedef struct
  46 {
  47   void *tcb;            /* Pointer to the TCB.  Not necessary the
  48                            thread descriptor used by libpthread.  */
  49   dtv_t *dtv;
  50   void *self;           /* Pointer to the thread descriptor.  */
  51   int multiple_threads;
  52   uintptr_t sysinfo;
  53   uintptr_t stack_guard;
  54   int gscope_flag;
  55 #ifndef __ASSUME_PRIVATE_FUTEX
  56   int private_futex;
  57 #endif
  58 } tcbhead_t;
  59
  60 # ifndef __s390x__
  61 #  define TLS_MULTIPLE_THREADS_IN_TCB 1
  62 # endif
  63
  64 #else /* __ASSEMBLER__ */
  65 # include <tcb-offsets.h>
  66 #endif
  67
  68
  69 /* We require TLS support in the tools.  */
  70 #ifndef HAVE_TLS_SUPPORT
  71 # error "TLS support is required."
  72 #endif
  73
  74 /* Alignment requirement for the stack.  For IA-32 this is governed by
  75    the SSE memory functions.  */
  76 #define STACK_ALIGN     16
  77
  78 #ifndef __ASSEMBLER__
  79 /* Get system call information.  */
  80 # include <sysdep.h>
  81
  82 /* Get the thread descriptor definition.  */
  83 # include <nptl/descr.h>
  84
  85 /* This is the size of the initial TCB.  Can't be just sizeof (tcbhead_t),
  86    because NPTL getpid, __libc_alloca_cutoff etc. need (almost) the whole
  87    struct pthread even when not linked with -lpthread.  */
  88 # define TLS_INIT_TCB_SIZE sizeof (struct pthread)
  89
  90 /* Alignment requirements for the initial TCB.  */
  91 # define TLS_INIT_TCB_ALIGN __alignof__ (struct pthread)
  92
  93 /* This is the size of the TCB.  */
  94 # define TLS_TCB_SIZE sizeof (struct pthread)
  95
  96 /* Alignment requirements for the TCB.  */
  97 # define TLS_TCB_ALIGN __alignof__ (struct pthread)
  98
  99 /* The TCB can have any size and the memory following the address the
 100    thread pointer points to is unspecified.  Allocate the TCB there.  */
 101 # define TLS_TCB_AT_TP  1
 102
 103
 104 /* Install the dtv pointer.  The pointer passed is to the element with
 105    index -1 which contain the length.  */
 106 #  define INSTALL_DTV(descr, dtvp) \
 107   ((tcbhead_t *) (descr))->dtv = (dtvp) + 1
 108
 109 /* Install new dtv for current thread.  */
 110 #  define INSTALL_NEW_DTV(dtv) \
 111   (((tcbhead_t *) __builtin_thread_pointer ())->dtv = (dtv))
 112
 113 /* Return dtv of given thread descriptor.  */
 114 #  define GET_DTV(descr) \
 115   (((tcbhead_t *) (descr))->dtv)
 116
 117 #if defined NEED_DL_SYSINFO && defined SHARED
 118 # define INIT_SYSINFO \
 119   _head->sysinfo = GLRO(dl_sysinfo)
 120 #else
 121 # define INIT_SYSINFO
 122 #endif
 123
 124 /* Code to initially initialize the thread pointer.  This might need
 125    special attention since 'errno' is not yet available and if the
 126    operation can cause a failure 'errno' must not be touched.  */
 127 # define TLS_INIT_TP(thrdescr, secondcall) \
 128   ({ void *_thrdescr = (thrdescr);                                            \
 129      tcbhead_t *_head = _thrdescr;                                            \
 130                                                                               \
 131      _head->tcb = _thrdescr;                                                  \
 132      /* For now the thread descriptor is at the same address.  */             \
 133      _head->self = _thrdescr;                                                 \
 134      /* New syscall handling support.  */                                     \
 135      INIT_SYSINFO;                                                            \
 136                                                                               \
 137     __builtin_set_thread_pointer (_thrdescr);                                 \
 138     NULL;                                                                     \
 139   })
 140
 141 /* Return the address of the dtv for the current thread.  */
 142 #  define THREAD_DTV() \
 143   (((tcbhead_t *) __builtin_thread_pointer ())->dtv)
 144
 145 /* Return the thread descriptor for the current thread.  */
 146 # define THREAD_SELF ((struct pthread *) __builtin_thread_pointer ())
 147
 148 /* Magic for libthread_db to know how to do THREAD_SELF.  */
 149 # define DB_THREAD_SELF REGISTER (32, 32, 18 * 4, 0) \
 150                         REGISTER (64, __WORDSIZE, 18 * 8, 0)
 151
 152 /* Access to data in the thread descriptor is easy.  */
 153 #define THREAD_GETMEM(descr, member) \
 154   descr->member
 155 #define THREAD_GETMEM_NC(descr, member, idx) \
 156   descr->member[idx]
 157 #define THREAD_SETMEM(descr, member, value) \
 158   descr->member = (value)
 159 #define THREAD_SETMEM_NC(descr, member, idx, value) \
 160   descr->member[idx] = (value)
 161
 162 /* Set the stack guard field in TCB head.  */
 163 #define THREAD_SET_STACK_GUARD(value) \
 164   do                                                                          \
 165    {                                                                          \
 166      __asm __volatile ("" : : : "a0", "a1");                                  \
 167      THREAD_SETMEM (THREAD_SELF, header.stack_guard, value);                  \
 168    }                                                                          \
 169   while (0)
 170 #define THREAD_COPY_STACK_GUARD(descr) \
 171   ((descr)->header.stack_guard                                                \
 172    = THREAD_GETMEM (THREAD_SELF, header.stack_guard))
 173
 174 /* s390 doesn't have HP_TIMING_*, so for the time being
 175    use stack_guard as pointer_guard.  */
 176 #define THREAD_GET_POINTER_GUARD() \
 177   THREAD_GETMEM (THREAD_SELF, header.stack_guard)
 178 #define THREAD_SET_POINTER_GUARD(value)
 179 #define THREAD_COPY_POINTER_GUARD(descr)
 180
 181 /* Get and set the global scope generation counter in struct pthread.  */
 182 #define THREAD_GSCOPE_FLAG_UNUSED 0
 183 #define THREAD_GSCOPE_FLAG_USED   1
 184 #define THREAD_GSCOPE_FLAG_WAIT   2
 185 #define THREAD_GSCOPE_RESET_FLAG() \
 186   do                                                                         \
 187     { int __res                                                              \
 188         = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,             \
 189                                THREAD_GSCOPE_FLAG_UNUSED);                   \
 190       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                  \
 191         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);   \
 192     }                                                                        \
 193   while (0)
 194 #define THREAD_GSCOPE_SET_FLAG() \
 195   do                                                                         \
 196     {                                                                        \
 197       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;             \
 198       atomic_write_barrier ();                                               \
 199     }                                                                        \
 200   while (0)
 201 #define THREAD_GSCOPE_WAIT() \
 202   GL(dl_wait_lookup_done) ()
 203
 204 #endif /* __ASSEMBLER__ */
 205
 206 #endif  /* tls.h */