/*
 * Copyright (c) 2014, Siemens AG. All rights reserved.
 *
 * 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 HOLDER 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.
 */

#ifndef EMBB_BASE_C_INTERNAL_ATOMIC_SWAP_H_
#define EMBB_BASE_C_INTERNAL_ATOMIC_SWAP_H_

#ifndef DOXYGEN

#include <embb/base/c/internal/config.h>
#include <embb/base/c/internal/atomic/atomic_sizes.h>
#include <embb/base/c/internal/macro_helper.h>
#include <embb/base/c/internal/atomic/atomic_variables.h>
#include <string.h>

/*
* See file and_assign.h for a detailed (and operation independent) description
* of the following macro.
*/
#ifdef EMBB_ARCH_X86

#ifdef EMBB_COMPILER_MSVC
#define EMBB_DEFINE_SWAP(EMBB_PARAMETER_SIZE_BYTE, EMBB_ATOMIC_X86_SIZE_SUFFIX) \
  extern EMBB_CAT2(EMBB_BASE_BASIC_TYPE_SIZE_, EMBB_PARAMETER_SIZE_BYTE) __fastcall EMBB_CAT2 (embb_internal__atomic_swap_, EMBB_PARAMETER_SIZE_BYTE)_asm(\
  EMBB_CAT2(EMBB_BASE_BASIC_TYPE_SIZE_, EMBB_PARAMETER_SIZE_BYTE) volatile* pointer_to_value, EMBB_CAT2(EMBB_BASE_BASIC_TYPE_SIZE_, EMBB_PARAMETER_SIZE_BYTE) new_value); \
  EMBB_INLINE EMBB_CAT2(EMBB_BASE_BASIC_TYPE_SIZE_, EMBB_PARAMETER_SIZE_BYTE) __fastcall EMBB_CAT2 (embb_internal__atomic_swap_, EMBB_PARAMETER_SIZE_BYTE)(\
  EMBB_CAT2(EMBB_BASE_BASIC_TYPE_SIZE_, EMBB_PARAMETER_SIZE_BYTE) volatile* pointer_to_value, EMBB_CAT2(EMBB_BASE_BASIC_TYPE_SIZE_, EMBB_PARAMETER_SIZE_BYTE) new_value) { \
  EMBB_CAT2(EMBB_BASE_BASIC_TYPE_SIZE_, EMBB_PARAMETER_SIZE_BYTE) result; \
  _ReadWriteBarrier(); \
  result = EMBB_CAT2(embb_internal__atomic_swap_, EMBB_PARAMETER_SIZE_BYTE)_asm(pointer_to_value, new_value); \
  _ReadWriteBarrier(); \
  return result; \
  }
#elif defined(EMBB_COMPILER_GNUC)
#define EMBB_DEFINE_SWAP(EMBB_PARAMETER_SIZE_BYTE, EMBB_ATOMIC_X86_SIZE_SUFFIX) \
  EMBB_INLINE EMBB_CAT2(EMBB_BASE_BASIC_TYPE_SIZE_, EMBB_PARAMETER_SIZE_BYTE) EMBB_CAT2(embb_internal__atomic_swap_, EMBB_PARAMETER_SIZE_BYTE)(\
  EMBB_CAT2(EMBB_BASE_BASIC_TYPE_SIZE_, EMBB_PARAMETER_SIZE_BYTE) volatile* pointer_to_value, EMBB_CAT2(EMBB_BASE_BASIC_TYPE_SIZE_, EMBB_PARAMETER_SIZE_BYTE) new_value)\
  { \
  /*the lock prefix is implicit for xchg*/  \
  __asm__ __volatile__("xchg" EMBB_ATOMIC_X86_SIZE_SUFFIX " %1, %0" \
  : "+m" (*pointer_to_value), "+q" (new_value) \
  : \
  : "memory"); \
  return new_value; \
  }
#else
#error "No atomic fetch and store implementation found"
#endif

/*
* The three or four macro calls below generate the methods for 1, 2, 4, and
* bytes, as stated in the macro definition.
*/
EMBB_DEFINE_SWAP(1, "b")
EMBB_DEFINE_SWAP(2, "w")
EMBB_DEFINE_SWAP(4, "l")
#ifdef EMBB_64_BIT_ATOMIC_AVAILABLE
EMBB_DEFINE_SWAP(8, "q")
#endif

#elif defined(EMBB_ARCH_ARM)

#if defined(EMBB_COMPILER_GNUC)
#define EMBB_DEFINE_SWAP(EMBB_PARAMETER_SIZE_BYTE, EMBB_ATOMIC_ARM_SIZE_SUFFIX) \
  EMBB_INLINE \
  EMBB_CAT2(EMBB_BASE_BASIC_TYPE_SIZE_, EMBB_PARAMETER_SIZE_BYTE) EMBB_CAT2 \
  (embb_internal__atomic_swap_, EMBB_PARAMETER_SIZE_BYTE)(\
  EMBB_CAT2(EMBB_BASE_BASIC_TYPE_SIZE_, EMBB_PARAMETER_SIZE_BYTE) \
  volatile* pointer_to_value, \
  EMBB_CAT2(EMBB_BASE_BASIC_TYPE_SIZE_, EMBB_PARAMETER_SIZE_BYTE) new_value)\
  { \
  register \
  EMBB_CAT2(EMBB_BASE_BASIC_TYPE_SIZE_, EMBB_PARAMETER_SIZE_BYTE) \
  t1, t2; \
  __asm__ __volatile__ ( \
  "dmb\n\t" \
  "loop_%=:\n\t" \
  "ldrex" EMBB_ATOMIC_ARM_SIZE_SUFFIX " %2, %0\n\t" \
  "strex" EMBB_ATOMIC_ARM_SIZE_SUFFIX " %3, %1, %0\n\t" \
  "teq %3, #0\n\t" \
  "bne loop_%=\n\t" \
  "mov %1, %2\n\t" \
  "isb" \
  : "+m" (*pointer_to_value), \
  "+r" (new_value), "=r" (t1), "=r" (t2) \
  : \
  : "memory", "cc" );               \
  return new_value; \
  }
#else
#error "No atomic fetch and store implementation found"
#endif

EMBB_DEFINE_SWAP(1, "b")
EMBB_DEFINE_SWAP(2, "h")
EMBB_DEFINE_SWAP(4, "")

#else
#error "Unknown architecture"
#endif

/*
* See file and_assign.h for a detailed (and operation independent) description
* of the following macro.
*/
#define EMBB_ATOMIC_INTERNAL_DEFINE_SWAP_METHOD(EMBB_ATOMIC_PARAMETER_TYPE_NATIVE, EMBB_ATOMIC_PARAMETER_ATOMIC_TYPE_SUFFIX, EMBB_ATOMIC_PARAMETER_TYPE_SIZE) \
  EMBB_INLINE EMBB_ATOMIC_PARAMETER_TYPE_NATIVE EMBB_CAT2(embb_atomic_swap_, EMBB_ATOMIC_PARAMETER_ATOMIC_TYPE_SUFFIX)(\
  EMBB_CAT2(embb_atomic_, EMBB_ATOMIC_PARAMETER_ATOMIC_TYPE_SUFFIX)* variable, EMBB_ATOMIC_PARAMETER_TYPE_NATIVE value) { \
  EMBB_CAT2(EMBB_BASE_BASIC_TYPE_SIZE_, EMBB_ATOMIC_PARAMETER_TYPE_SIZE) value_pun; \
  memcpy(&value_pun, &value, sizeof(EMBB_ATOMIC_PARAMETER_TYPE_NATIVE)); \
  EMBB_CAT2(EMBB_BASE_BASIC_TYPE_SIZE_, EMBB_ATOMIC_PARAMETER_TYPE_SIZE) \
  return_val = EMBB_CAT2(embb_internal__atomic_swap_, EMBB_ATOMIC_PARAMETER_TYPE_SIZE)((EMBB_CAT2(EMBB_BASE_BASIC_TYPE_SIZE_, EMBB_ATOMIC_PARAMETER_TYPE_SIZE) volatile *)(&(variable->internal_variable)), value_pun); \
  EMBB_ATOMIC_PARAMETER_TYPE_NATIVE return_val_pun; \
  memcpy(&return_val_pun, &return_val, sizeof(EMBB_ATOMIC_PARAMETER_TYPE_NATIVE)); \
  return return_val_pun; \
  }

#undef EMBB_ATOMIC_METHOD_TO_GENERATE
#define EMBB_ATOMIC_METHOD_TO_GENERATE SWAP_METHOD
#include <embb/base/c/internal/atomic/generate_atomic_implementation_template.h>
#undef EMBB_ATOMIC_METHOD_TO_GENERATE

#endif //DOXYGEN

#endif //EMBB_BASE_C_INTERNAL_ATOMIC_SWAP_H_