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/*
* Copyright (c) 2004 The Regents of The University of Michigan
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* 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;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* 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.
*/
//The purpose of this file is to provide endainness conversion utility
//functions. Depending on the endianness of the guest system, either
//the LittleEndianGuest or BigEndianGuest namespace is used.
#ifndef __SIM_BYTE_SWAP_HH__
#define __SIM_BYTE_SWAP_HH__
// This lets us figure out what the byte order of the host system is
#if defined(__linux__)
#include <endian.h>
// If this is a linux system, lets used the optimized definitions if they exist.
// If one doesn't exist, we pretty much get what is listed below, so it all
// works out
#include <byteswap.h>
#elif defined (__sun)
#include <sys/isa_defs.h>
#else
#include <machine/endian.h>
#endif
#if defined(__APPLE__)
#include <libkern/OSByteOrder.h>
#endif
#include <type_traits>
#include "base/types.hh"
#include "enums/ByteOrder.hh"
struct vring_used_elem;
struct vring_desc;
namespace gem5
{
// These functions actually perform the swapping for parameters of various bit
// lengths.
inline uint64_t
swap_byte64(uint64_t x)
{
#if defined(__linux__)
return bswap_64(x);
#elif defined(__APPLE__)
return OSSwapInt64(x);
#else
return (uint64_t)((((uint64_t)(x) & 0xff) << 56) |
((uint64_t)(x) & 0xff00ULL) << 40 |
((uint64_t)(x) & 0xff0000ULL) << 24 |
((uint64_t)(x) & 0xff000000ULL) << 8 |
((uint64_t)(x) & 0xff00000000ULL) >> 8 |
((uint64_t)(x) & 0xff0000000000ULL) >> 24 |
((uint64_t)(x) & 0xff000000000000ULL) >> 40 |
((uint64_t)(x) & 0xff00000000000000ULL) >> 56) ;
#endif
}
inline uint32_t
swap_byte32(uint32_t x)
{
#if defined(__linux__)
return bswap_32(x);
#elif defined(__APPLE__)
return OSSwapInt32(x);
#else
return (uint32_t)(((uint32_t)(x) & 0xff) << 24 |
((uint32_t)(x) & 0xff00) << 8 | ((uint32_t)(x) & 0xff0000) >> 8 |
((uint32_t)(x) & 0xff000000) >> 24);
#endif
}
inline uint16_t
swap_byte16(uint16_t x)
{
#if defined(__linux__)
return bswap_16(x);
#elif defined(__APPLE__)
return OSSwapInt16(x);
#else
return (uint16_t)(((uint16_t)(x) & 0xff) << 8 |
((uint16_t)(x) & 0xff00) >> 8);
#endif
}
template <typename T>
inline std::enable_if_t<
sizeof(T) == 8 && std::is_convertible<T, uint64_t>::value, T>
swap_byte(T x)
{
return swap_byte64((uint64_t)x);
}
template <typename T>
inline std::enable_if_t<
sizeof(T) == 4 && std::is_convertible<T, uint32_t>::value, T>
swap_byte(T x)
{
return swap_byte32((uint32_t)x);
}
template <typename T>
inline std::enable_if_t<
sizeof(T) == 2 && std::is_convertible<T, uint16_t>::value, T>
swap_byte(T x)
{
return swap_byte16((uint16_t)x);
}
template <typename T>
inline std::enable_if_t<
sizeof(T) == 1 && std::is_convertible<T, uint8_t>::value, T>
swap_byte(T x)
{
return x;
}
// Make the function visible in case we need to declare a version of it for
// other types
template <typename T>
std::enable_if_t<std::is_same<T, vring_used_elem>::value, T>
swap_byte(T v);
template <typename T>
std::enable_if_t<std::is_same<T, vring_desc>::value, T>
swap_byte(T v);
template <typename T, size_t N>
inline std::array<T, N>
swap_byte(std::array<T, N> a)
{
for (T &v: a)
v = swap_byte(v);
return a;
}
//The conversion functions with fixed endianness on both ends don't need to
//be in a namespace
template <typename T> inline T betole(T value) {return swap_byte(value);}
template <typename T> inline T letobe(T value) {return swap_byte(value);}
//For conversions not involving the guest system, we can define the functions
//conditionally based on the BYTE_ORDER macro and outside of the namespaces
#if (defined(_BIG_ENDIAN) || !defined(_LITTLE_ENDIAN)) && BYTE_ORDER == BIG_ENDIAN
const ByteOrder HostByteOrder = ByteOrder::big;
template <typename T> inline T htole(T value) {return swap_byte(value);}
template <typename T> inline T letoh(T value) {return swap_byte(value);}
template <typename T> inline T htobe(T value) {return value;}
template <typename T> inline T betoh(T value) {return value;}
#elif defined(_LITTLE_ENDIAN) || BYTE_ORDER == LITTLE_ENDIAN
const ByteOrder HostByteOrder = ByteOrder::little;
template <typename T> inline T htole(T value) {return value;}
template <typename T> inline T letoh(T value) {return value;}
template <typename T> inline T htobe(T value) {return swap_byte(value);}
template <typename T> inline T betoh(T value) {return swap_byte(value);}
#else
#error Invalid Endianess
#endif
template <typename T>
inline T htog(T value, ByteOrder guest_byte_order)
{
return guest_byte_order == ByteOrder::big ?
htobe(value) : htole(value);
}
template <typename T>
inline T gtoh(T value, ByteOrder guest_byte_order)
{
return guest_byte_order == ByteOrder::big ?
betoh(value) : letoh(value);
}
} // namespace gem5
#endif // __SIM_BYTE_SWAP_HH__