include/endian.h


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/* SPDX-License-Identifier: GPL-2.0+ */
/*
 * endian.h - byte order swaps. arm64 and ppc64le are both little
 * endian, so the macros compile to nothing there, but the big endian
 * fallbacks stay so a BE target builds without a rewrite.
 *
 * Copyright (C) 2026 Bradley Morgan <brads@mainlining.org>
 */

#ifndef __ENDIAN_H
#define __ENDIAN_H

#include <stdint.h>

static inline uint16_t __swap16(uint16_t x)
{
	return (uint16_t)((x << 8) | (x >> 8));
}

static inline uint32_t __swap32(uint32_t x)
{
	return ((x << 24) |
		((x & 0xff00) << 8) |
		((x & 0xff0000) >> 8) |
		(x >> 24));
}

static inline uint64_t __swap64(uint64_t x)
{
	return ((uint64_t)__swap32((uint32_t)x) << 32) |
	       __swap32((uint32_t)(x >> 32));
}

#if defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__

#define le16_to_cpu(x)	__swap16(x)
#define le32_to_cpu(x)	__swap32(x)
#define le64_to_cpu(x)	__swap64(x)
#define cpu_to_le16(x)	__swap16(x)
#define cpu_to_le32(x)	__swap32(x)
#define cpu_to_le64(x)	__swap64(x)

#else

#define le16_to_cpu(x)	(x)
#define le32_to_cpu(x)	(x)
#define le64_to_cpu(x)	(x)
#define cpu_to_le16(x)	(x)
#define cpu_to_le32(x)	(x)
#define cpu_to_le64(x)	(x)

#endif

#endif