glibc/sysdeps/hppa/nptl/tls.h

/* Definition for thread-local data handling.  NPTL/hppa version.
   Copyright (C) 2005-2021 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, see
   <https://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.  */
# define TLS_INIT_TCB_SIZE	sizeof (tcbhead_t)

/* Alignment requirements for the initial TCB.  */
# define TLS_INIT_TCB_ALIGN	__alignof__ (tcbhead_t)

/* This is the size of the TCB.  */
# define TLS_TCB_SIZE		sizeof (tcbhead_t)

/* Alignment requirements for the TCB.  */
# define TLS_TCB_ALIGN		__alignof__ (struct pthread)

/* This is the size we need before TCB */
# define TLS_PRE_TCB_SIZE	sizeof (struct pthread)

/* 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))->dtv = (dtvp) + 1

/* Install new dtv for current thread.  */
# define INSTALL_NEW_DTV(dtv) \
  ({ tcbhead_t *__tcbp = (tcbhead_t *)__get_cr27();	\
	__tcbp->dtv = dtv;				\
   })

/* Return dtv of given thread descriptor.  */
# define GET_DTV(tcbp) \
  (((tcbhead_t *) (tcbp))->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) \
  ({ __set_cr27(tcbp); NULL; })

/* Value passed to 'clone' for initialization of the thread register.  */
# define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd) + 1

/* Return the address of the dtv for the current thread.  */
# define THREAD_DTV() \
  ({ tcbhead_t *__tcbp = (tcbhead_t *)__get_cr27();	\
	__tcbp->dtv;					\
   })

/* Return the thread descriptor for the current thread.  */
# define THREAD_SELF \
  ({ struct pthread *__self;			\
	__self = __get_cr27();			\
	__self - 1;				\
   })

/* Magic for libthread_db to know how to do THREAD_SELF.
   Our thread pointer is stored in cr27.  See asm/elf.h for the offset into
   elf_gregset_t.  The thread descriptor is sizeof (struct pthread) away.  */
# define DB_THREAD_SELF \
  REGISTER (32, 32, 53 * 4, -sizeof (struct pthread))

/* 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)

static inline struct pthread *__get_cr27(void)
{
  long cr27;
  asm ("mfctl %%cr27, %0" : "=r" (cr27) : );
  return (struct pthread *) cr27;
}

/* We write to cr27, clobber r26 as the input argument, and clobber
   r31 as the link register.  */
static inline void __set_cr27(struct pthread *cr27)
{
  asm ( "ble	0xe0(%%sr2, %%r0)\n\t"
	"copy	%0, %%r26"
	: : "r" (cr27) : "r26", "r31" );
}

/* Get and set the global scope generation counter in struct pthread.  */
#define THREAD_GSCOPE_IN_TCB      1
#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)

#endif /* !__ASSEMBLER__ */

#endif	/* tls.h */