/* SPDX-License-Identifier: BSD-2-Clause */

/**
 * @file
 *
 * @ingroup RTEMSScoreTLS
 *
 * @brief This source file contains the implementation of
 *   _TLS_Get_allocation_size().
 */

/*
 * Copyright (C) 2014, 2023 embedded brains GmbH & Co. KG
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <rtems/score/tls.h>
#include <rtems/score/interr.h>
#include <rtems/score/thread.h>

extern char _TLS_Data_begin[];

extern char _TLS_Data_size[];

extern char _TLS_BSS_begin[];

extern char _TLS_BSS_size[];

extern char _TLS_Size[];

/**
 * @brief The TLS section alignment.
 *
 * This symbol is provided by the linker command file as the maximum alignment
 * of the .tdata and .tbss sections.  The linker ensures that the first TLS
 * output section is aligned to the maximum alignment of all TLS output
 * sections, see function _bfd_elf_tls_setup() in bfd/elflink.c of the GNU
 * Binutils sources.  The linker command file must take into account the case
 * that the .tdata section is empty and the .tbss section is non-empty.
 */
extern char _TLS_Alignment[];

const volatile TLS_Configuration _TLS_Configuration = {
  .data_begin = _TLS_Data_begin,
  .data_size = _TLS_Data_size,
  .bss_begin = _TLS_BSS_begin,
  .bss_size = _TLS_BSS_size,
  .size = _TLS_Size,
  .alignment = _TLS_Alignment
};

static uintptr_t _TLS_Allocation_size;

uintptr_t _TLS_Get_allocation_size( void )
{
  const volatile TLS_Configuration *config;
  uintptr_t                         size;
  uintptr_t                         allocation_size;

  config = &_TLS_Configuration;
  size = (uintptr_t) config->size;

  if ( size == 0 ) {
    return 0;
  }

  allocation_size = _TLS_Allocation_size;

  if ( allocation_size == 0 ) {
    uintptr_t tls_align;
    uintptr_t stack_align;

    /*
     * The TLS area is allocated in the thread storage area.  Each allocation
     * shall meet the stack alignment requirement.
     */
    stack_align = CPU_STACK_ALIGNMENT;
    tls_align = RTEMS_ALIGN_UP( (uintptr_t) config->alignment, stack_align );

#ifndef __i386__
    /* Reserve space for the dynamic thread vector */
    allocation_size +=
      RTEMS_ALIGN_UP( sizeof( TLS_Dynamic_thread_vector ), stack_align );
#endif

    /* Reserve space for the thread control block */
    allocation_size +=
#if CPU_THREAD_LOCAL_STORAGE_VARIANT == 11
      RTEMS_ALIGN_UP( sizeof( TLS_Thread_control_block ), tls_align );
#else
      RTEMS_ALIGN_UP( sizeof( TLS_Thread_control_block ), stack_align );
#endif

    /* Reserve space for the thread-local storage data */
    allocation_size +=
#if CPU_THREAD_LOCAL_STORAGE_VARIANT == 20
      RTEMS_ALIGN_UP( size, tls_align );
#else
      RTEMS_ALIGN_UP( size, stack_align );
#endif

    /*
     * The stack allocator does not support aligned allocations.  Allocate
     * enough to do the alignment manually.
     */
    if ( tls_align > stack_align ) {
      _Assert( tls_align % stack_align == 0 );
      allocation_size += tls_align - stack_align;
    }

    if ( _Thread_Maximum_TLS_size != 0 ) {
      if ( allocation_size <= _Thread_Maximum_TLS_size ) {
        _Assert( _Thread_Maximum_TLS_size % CPU_STACK_ALIGNMENT == 0 );
        allocation_size = _Thread_Maximum_TLS_size;
      } else {
        _Internal_error( INTERNAL_ERROR_TOO_LARGE_TLS_SIZE );
      }
    }

    _TLS_Allocation_size = allocation_size;
  }

  return allocation_size;
}