linuxthreads/sysdeps/sh/tls.h

   1 /* Definition for thread-local data handling.  linuxthreads/SH version.
   2    Copyright (C) 2002, 2003 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
  22
  23 # include <dl-sysdep.h>
  24 # include <pt-machine.h>
  25
  26 #ifndef __ASSEMBLER__
  27 # include <stddef.h>
  28 # include <stdint.h>
  29
  30 /* Type for the dtv.  */
  31 typedef union dtv
  32 {
  33   size_t counter;
  34   void *pointer;
  35 } dtv_t;
  36
  37 #else /* __ASSEMBLER__ */
  38 # include <tcb-offsets.h>
  39 #endif /* __ASSEMBLER__ */
  40
  41
  42 /* We can support TLS only if the floating-stack support is available.  */
  43 #if defined HAVE_TLS_SUPPORT \
  44     && (defined FLOATING_STACKS || !defined IS_IN_libpthread)
  45
  46 /* Signal that TLS support is available.  */
  47 # define USE_TLS        1
  48
  49 # ifndef __ASSEMBLER__
  50
  51 typedef struct
  52 {
  53   dtv_t *dtv;
  54   void *private;
  55 } tcbhead_t;
  56
  57 /* This is the size of the initial TCB.  */
  58 #  define TLS_INIT_TCB_SIZE sizeof (tcbhead_t)
  59
  60 /* Alignment requirements for the initial TCB.  */
  61 #  define TLS_INIT_TCB_ALIGN __alignof__ (tcbhead_t)
  62
  63 /* This is the size of the TCB.  */
  64 #  define TLS_TCB_SIZE sizeof (tcbhead_t)
  65
  66 /* This is the size we need before TCB.  */
  67 #  define TLS_PRE_TCB_SIZE sizeof (struct _pthread_descr_struct)
  68
  69 /* Alignment requirements for the TCB.  */
  70 #  define TLS_TCB_ALIGN __alignof__ (struct _pthread_descr_struct)
  71
  72 /* The TLS blocks start right after the TCB.  */
  73 #  define TLS_DTV_AT_TP 1
  74
  75 /* Install the dtv pointer.  The pointer passed is to the element with
  76    index -1 which contain the length.  */
  77 #  define INSTALL_DTV(tcbp, dtvp) \
  78   ((tcbhead_t *) (tcbp))->dtv = dtvp + 1
  79
  80 /* Install new dtv for current thread.  */
  81 #  define INSTALL_NEW_DTV(dtv) \
  82   ({ tcbhead_t *__tcbp;                                                       \
  83      __asm __volatile ("stc gbr,%0" : "=r" (__tcbp));                         \
  84      __tcbp->dtv = (dtv);})
  85
  86 /* Return dtv of given thread descriptor.  */
  87 #  define GET_DTV(tcbp) \
  88   (((tcbhead_t *) (tcbp))->dtv)
  89
  90 /* Code to initially initialize the thread pointer.  This might need
  91    special attention since 'errno' is not yet available and if the
  92    operation can cause a failure 'errno' must not be touched.  */
  93 #  define TLS_INIT_TP(tcbp, secondcall) \
  94   ({ __asm __volatile ("ldc %0,gbr" : : "r" (tcbp)); 0; })
  95
  96 /* Return the address of the dtv for the current thread.  */
  97 #  define THREAD_DTV() \
  98   ({ tcbhead_t *__tcbp;                                                       \
  99      __asm __volatile ("stc gbr,%0" : "=r" (__tcbp));                         \
 100      __tcbp->dtv;})
 101
 102 /* Return the thread descriptor for the current thread.  */
 103 #  undef THREAD_SELF
 104 #  define THREAD_SELF \
 105   ({ struct _pthread_descr_struct *__self;                                    \
 106      __asm ("stc gbr,%0" : "=r" (__self));                                    \
 107      __self - 1;})
 108
 109 #  undef INIT_THREAD_SELF
 110 #  define INIT_THREAD_SELF(descr, nr) \
 111   ({ struct _pthread_descr_struct *__self = (void *) descr;                   \
 112      __asm __volatile ("ldc %0,gbr" : : "r" (__self + 1));                    \
 113      0; })
 114
 115 # define TLS_MULTIPLE_THREADS_IN_TCB 1
 116
 117 /* Get the thread descriptor definition.  This must be after the
 118    the definition of THREAD_SELF for TLS.  */
 119 #  include <linuxthreads/descr.h>
 120
 121 # endif /* __ASSEMBLER__ */
 122
 123 #else
 124
 125 # ifndef __ASSEMBLER__
 126
 127 typedef struct
 128 {
 129   void *tcb;
 130   dtv_t *dtv;
 131   void *self;
 132   int multiple_threads;
 133 } tcbhead_t;
 134
 135 /* Get the thread descriptor definition.  */
 136 #  include <linuxthreads/descr.h>
 137
 138 #  define NONTLS_INIT_TP \
 139   do {                                                                  \
 140     static const tcbhead_t nontls_init_tp = { .multiple_threads = 0 };  \
 141     __asm __volatile ("ldc %0,gbr" : : "r" (&nontls_init_tp));          \
 142   } while (0)
 143
 144 # endif /* __ASSEMBLER__ */
 145
 146 #endif  /* HAVE_TLS_SUPPORT && (FLOATING_STACKS || !IS_IN_libpthread) */
 147
 148 #endif  /* tls.h */