/* Definition for thread-local data handling.  NPTL/MIPS version.
   Copyright (C) 2005, 2007 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   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, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#ifndef _TLS_H
#define _TLS_H	1

#include <dl-sysdep.h>

#ifndef __ASSEMBLER__
# include <stdbool.h>
# include <stddef.h>
# include <stdint.h>

/* Type for the dtv.  */
typedef union dtv
{
  size_t counter;
  struct
  {
    void *val;
    bool is_static;
  } pointer;
} dtv_t;

register void* __thread_self asm("tp");
# define READ_THREAD_POINTER() ({ __thread_self; })

#endif /* __ASSEMBLER__ */

/* Signal that TLS support is available.  */
#define USE_TLS	1

#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

typedef struct
{
  dtv_t *dtv;
  void *private;
} tcbhead_t;

typedef struct rthread {
    struct
    {
      int multiple_threads;
      int gscope_flag;
# ifndef __ASSUME_PRIVATE_FUTEX
      int private_futex;
# endif
    } header;

	void* __padding[1];
} rthread_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 rthread)

/* 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 rthread)

/* This is the size we need before TCB - actually, it includes the TCB.  */
# define TLS_PRE_TCB_SIZE \
  (sizeof (struct rthread)						      \
   + ((sizeof (tcbhead_t) + TLS_TCB_ALIGN - 1) & ~(TLS_TCB_ALIGN - 1)))

/* The thread pointer (in hardware register $29) points to the end of
   the TCB + 0x7000, as for PowerPC.  The rthread_descr structure is
   immediately in front of the TCB.  */
# 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. */
# define TLS_INIT_TP(tcbp, secondcall) \
  ({ __thread_self = (char*)tcbp + TLS_TCB_OFFSET; NULL; })

/* Return the address of the dtv for the current thread.  */
# define THREAD_DTV() \
  (((tcbhead_t *) (READ_THREAD_POINTER () - TLS_TCB_OFFSET))[-1].dtv)

/* Return the thread descriptor for the current thread.  */
# define THREAD_SELF \
 ((struct rthread *) (READ_THREAD_POINTER ()			     \
		      - 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 MIPS, 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 rthread.  */
#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) ()

static inline void *__get_tls_desc(void)
{
	return READ_THREAD_POINTER() - TLS_TCB_OFFSET;
}

static inline void __set_tls_desc(void *tls_desc)
{
	TLS_INIT_TP(tls_desc, 0);
}

#endif /* __ASSEMBLER__ */

#endif	/* tls.h */