/* Thread-local storage handling in the ELF dynamic linker.  s390 version.

   Copyright (C) 2003-2018 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

   <http://www.gnu.org/licenses/>.  */

/* Type used for the representation of TLS information in the GOT.  */

typedef struct

{

  unsigned long int ti_module;

  unsigned long int ti_offset;

} tls_index;

#ifdef SHARED

extern unsigned long __tls_get_offset (unsigned long got_offset);

# if IS_IN (rtld)

#  include <shlib-compat.h>

/* dl-tls.c declares __tls_get_addr as an exported symbol if it is not defined

   as a macro.  It seems suitable to do that in the generic code because all

   architectures other than s390 export __tls_get_addr.  The declaration causes

   problems in s390 though, so we define __tls_get_addr here to avoid declaring

   __tls_get_addr again.  */

#  define __tls_get_addr __tls_get_addr

extern void *__tls_get_addr (tls_index *ti) attribute_hidden;

/* Make a temporary alias of __tls_get_addr to remove the hidden

   attribute.  Then export __tls_get_addr as __tls_get_addr_internal

   for use from libc.  We do not want to export __tls_get_addr, but we

   do need to use it from libc when looking up the address of a TLS

   variable. We don't use __tls_get_offset because it requires r12 to

   be setup and that might not always be true. Either way it's more

   optimal to use __tls_get_addr directly (that's what

   __tls_get_offset does anyways).  */

strong_alias (__tls_get_addr, __tls_get_addr_internal_tmp);

versioned_symbol (ld, __tls_get_addr_internal_tmp,

		  __tls_get_addr_internal, GLIBC_PRIVATE);

/* The special thing about the s390 TLS ABI is that we do not have the

   standard __tls_get_addr function but the __tls_get_offset function

   which differs in two important aspects:

   1) __tls_get_offset gets a got offset instead of a pointer to the

      tls_index structure

   2) __tls_get_offset returns the offset of the requested variable to

      the thread descriptor instead of a pointer to the variable.

 */

#  ifdef __s390x__

__asm__("\n\

	.text\n\

	.globl __tls_get_offset\n\

	.type __tls_get_offset, @function\n\

	.align 4\n\

__tls_get_offset:\n\

	la	%r2,0(%r2,%r12)\n\

	jg	__tls_get_addr\n\

");

#  elif defined __s390__

__asm__("\n\

	.text\n\

	.globl __tls_get_offset\n\

	.type __tls_get_offset, @function\n\

	.align 4\n\

__tls_get_offset:\n\

	basr	%r3,0\n\

0:	la	%r2,0(%r2,%r12)\n\

	l	%r4,1f-0b(%r3)\n\

	b	0(%r4,%r3)\n\

1:	.long	__tls_get_addr - 0b\n\

");

#  endif

# else /* IS_IN (rtld) */

extern void *__tls_get_addr_internal (tls_index *ti);

# endif /* !IS_IN (rtld) */

# define GET_ADDR_OFFSET \

  (ti->ti_offset - (unsigned long) __builtin_thread_pointer ())

/* Use the privately exported __tls_get_addr_internal instead of

   __tls_get_offset in order to avoid the __tls_get_offset special

   linkage requiring the GOT pointer to be set up in r12.  The

   compiler will take care of setting up r12 only if itself issued the

   __tls_get_offset call.  */

# define __TLS_GET_ADDR(__ti)					\

  ({ __tls_get_addr_internal (__ti)				\

      + (unsigned long) __builtin_thread_pointer (); })

#endif