text: /* Definition for thread-local data handling.  NPTL/m68k version.
     Copyright (C) 2010-2017 Free Software Foundation, Inc.
     This file is part of the GNU C Library.
     Contributed by Maxim Kuvyrkov <maxim@codesourcery.com>, 2010.
  
     The GNU C Library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Lesser General Public
     License as published by the Free Software Foundation; either
     version 2.1 of the License, or (at your option) any later version.
  
     The GNU C Library is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     Lesser General Public License for more details.
  
     You should have received a copy of the GNU Lesser General Public
     License along with the GNU C Library.  If not, see
     <http://www.gnu.org/licenses/>.  */
  
  #ifndef _TLS_H
  #define _TLS_H	1
  
  #include <dl-sysdep.h>
  
  #ifndef __ASSEMBLER__
  # include <stdbool.h>
  # include <stddef.h>
  # include <stdint.h>
  # include <dl-dtv.h>
  
  #else /* __ASSEMBLER__ */
  # include <tcb-offsets.h>
  #endif /* __ASSEMBLER__ */
  
  #ifndef __ASSEMBLER__
  
  /* Get system call information.  */
  # include <sysdep.h>
  
  /* The TP points to the start of the thread blocks.  */
  # define TLS_DTV_AT_TP	1
  # define TLS_TCB_AT_TP	0
  
  /* Get the thread descriptor definition.  */
  # include <nptl/descr.h>
  
  typedef struct
  {
    dtv_t *dtv;
    void *private;
  } tcbhead_t;
  
  /* This is the size of the initial TCB.  Because our TCB is before the thread
     pointer, we don't need this.  */
  # define TLS_INIT_TCB_SIZE	0
  
  /* Alignment requirements for the initial TCB.  */
  # define TLS_INIT_TCB_ALIGN	__alignof__ (struct pthread)
  
  /* This is the size of the TCB.  Because our TCB is before the thread
     pointer, we don't need this.  */
  # define TLS_TCB_SIZE		0
  
  /* Alignment requirements for the TCB.  */
  # define TLS_TCB_ALIGN		__alignof__ (struct pthread)
  
  /* This is the size we need before TCB - actually, it includes the TCB.  */
  # define TLS_PRE_TCB_SIZE						\
    (sizeof (struct pthread)						\
     + ((sizeof (tcbhead_t) + TLS_TCB_ALIGN - 1) & ~(TLS_TCB_ALIGN - 1)))
  
  /* The thread pointer (TP) points to the end of the
     TCB + 0x7000, as for PowerPC and MIPS.  This implies that TCB address is
     TP - 0x7000.  As we define TLS_DTV_AT_TP we can
     assume that the pthread struct is allocated immediately ahead of the
     TCB.  This implies that the pthread_descr address is
     TP - (TLS_PRE_TCB_SIZE + 0x7000).  */
  # define TLS_TCB_OFFSET	0x7000
  
  /* Install the dtv pointer.  The pointer passed is to the element with
     index -1 which contain the length.  */
  # define INSTALL_DTV(tcbp, dtvp) \
    ((tcbhead_t *) (tcbp))[-1].dtv = dtvp + 1
  
  /* Install new dtv for current thread.  */
  # define INSTALL_NEW_DTV(dtv) \
    (THREAD_DTV () = (dtv))
  
  /* Return dtv of given thread descriptor.  */
  # define GET_DTV(tcbp) \
    (((tcbhead_t *) (tcbp))[-1].dtv)
  
  /* Code to initially initialize the thread pointer.  This might need
     special attention since 'errno' is not yet available and if the
     operation can cause a failure 'errno' must not be touched.  */
  # define TLS_INIT_TP(tcbp)						\
    ({									\
      INTERNAL_SYSCALL_DECL (err);					\
      int _sys_result;							\
  									\
      _sys_result = INTERNAL_SYSCALL (set_thread_area, err, 1,		\
  				    ((void *) (tcbp)) + TLS_TCB_OFFSET); \
      INTERNAL_SYSCALL_ERROR_P (_sys_result, err) ? "unknown error" : NULL; })
  
  # define TLS_DEFINE_INIT_TP(tp, pd) \
    void *tp = (void *) (pd) + TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE
  
  extern void * __m68k_read_tp (void);
  
  /* Return the address of the dtv for the current thread.  */
  # define THREAD_DTV() \
    (((tcbhead_t *) (__m68k_read_tp () - TLS_TCB_OFFSET))[-1].dtv)
  
  /* Return the thread descriptor for the current thread.  */
  # define THREAD_SELF \
    ((struct pthread *) (__m68k_read_tp () - TLS_TCB_OFFSET - TLS_PRE_TCB_SIZE))
  
  /* Magic for libthread_db to know how to do THREAD_SELF.  */
  # define DB_THREAD_SELF \
    CONST_THREAD_AREA (32, TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE)
  
  /* Access to data in the thread descriptor is easy.  */
  # define THREAD_GETMEM(descr, member) \
    descr->member
  # define THREAD_GETMEM_NC(descr, member, idx) \
    descr->member[idx]
  # define THREAD_SETMEM(descr, member, value) \
    descr->member = (value)
  # define THREAD_SETMEM_NC(descr, member, idx, value) \
    descr->member[idx] = (value)
  
  /* l_tls_offset == 0 is perfectly valid on M68K, so we have to use some
     different value to mean unset l_tls_offset.  */
  # define NO_TLS_OFFSET		-1
  
  /* Get and set the global scope generation counter in struct pthread.  */
  #define THREAD_GSCOPE_FLAG_UNUSED 0
  #define THREAD_GSCOPE_FLAG_USED   1
  #define THREAD_GSCOPE_FLAG_WAIT   2
  #define THREAD_GSCOPE_RESET_FLAG()					\
    do									\
      { int __res								\
  	= atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,	\
  			       THREAD_GSCOPE_FLAG_UNUSED);		\
        if (__res == THREAD_GSCOPE_FLAG_WAIT)				\
  	lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE); \
      }									\
    while (0)
  #define THREAD_GSCOPE_SET_FLAG()					\
    do									\
      {									\
        THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;	\
        atomic_write_barrier ();						\
      }									\
    while (0)
  #define THREAD_GSCOPE_WAIT() \
    GL(dl_wait_lookup_done) ()
  
  #endif /* __ASSEMBLER__ */
  
  #endif	/* tls.h */
  