[PATCH 1/2] include: Add support for byteorder/endianness conversion

[Sergey Matyukevich]

On Sat, Jan 28, 2023 at 01:16:16PM +0530, Rahul Pathak wrote:
> Define macros for general byteorder conversion
> Define functions for endianness conversion
> using general byteorder conversion macros
> 
> Signed-off-by: Rahul Pathak <rpathak at ventanamicro.com>
> ---
>  include/sbi/sbi_byteorder.h | 57 +++++++++++++++++++++++++++++++++++++
>  1 file changed, 57 insertions(+)
>  create mode 100644 include/sbi/sbi_byteorder.h

Reviewed-by: Sergey Matyukevich <sergey.matyukevich at syntacore.com>

By the way, is there any advantage of using custom macros instead of
compiler builtins ? E.g. see my patch loosely based on FreeBSD code:
http://lists.infradead.org/pipermail/opensbi/2022-December/003766.html

Regards,
Sergey


> diff --git a/include/sbi/sbi_byteorder.h b/include/sbi/sbi_byteorder.h
> new file mode 100644
> index 000000000000..680710fe6d91
> --- /dev/null
> +++ b/include/sbi/sbi_byteorder.h
> @@ -0,0 +1,57 @@
> +/*
> + * SPDX-License-Identifier: BSD-2-Clause
> + *
> + * Copyright (c) 2023 Ventana Micro Systems Inc.
> + */
> +
> +#ifndef __SBI_BYTEORDER_H__
> +#define __SBI_BYTEORDER_H__
> +
> +#include <sbi/sbi_types.h>
> +
> +#define EXTRACT_BYTE(x, n)	((unsigned long long)((uint8_t *)&x)[n])
> +
> +#define BSWAP16(x)	((EXTRACT_BYTE(x, 0) << 8) | EXTRACT_BYTE(x, 1))
> +#define BSWAP32(x)	((EXTRACT_BYTE(x, 0) << 24) | (EXTRACT_BYTE(x, 1) << 16) | \
> +			 (EXTRACT_BYTE(x, 2) << 8) | EXTRACT_BYTE(x, 3))
> +#define BSWAP64(x)	((EXTRACT_BYTE(x, 0) << 56) | (EXTRACT_BYTE(x, 1) << 48) | \
> +			 (EXTRACT_BYTE(x, 2) << 40) | (EXTRACT_BYTE(x, 3) << 32) | \
> +			 (EXTRACT_BYTE(x, 4) << 24) | (EXTRACT_BYTE(x, 5) << 16) | \
> +			 (EXTRACT_BYTE(x, 6) << 8) | EXTRACT_BYTE(x, 7))
> +
> +
> +#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__  /* CPU(little-endian) */
> +#define cpu_to_be16(x)		((uint16_t)BSWAP16(x))
> +#define cpu_to_be32(x)		((uint32_t)BSWAP32(x))
> +#define cpu_to_be64(x)		((uint64_t)BSWAP64(x))
> +
> +#define be16_to_cpu(x)		((uint16_t)BSWAP16(x))
> +#define be32_to_cpu(x)		((uint32_t)BSWAP32(x))
> +#define be64_to_cpu(x)		((uint64_t)BSWAP64(x))
> +
> +#define cpu_to_le16(x)		((uint16_t)(x))
> +#define cpu_to_le32(x)		((uint32_t)(x))
> +#define cpu_to_le64(x)		((uint64_t)(x))
> +
> +#define le16_to_cpu(x)		((uint16_t)(x))
> +#define le32_to_cpu(x)		((uint32_t)(x))
> +#define le64_to_cpu(x)		((uint64_t)(x))
> +#else /* CPU(big-endian) */
> +#define cpu_to_be16(x)		((uint16_t)(x))
> +#define cpu_to_be32(x)		((uint32_t)(x))
> +#define cpu_to_be64(x)		((uint64_t)(x))
> +
> +#define be16_to_cpu(x)		((uint16_t)(x))
> +#define be32_to_cpu(x)		((uint32_t)(x))
> +#define be64_to_cpu(x)		((uint64_t)(x))
> +
> +#define cpu_to_le16(x)		((uint16_t)BSWAP16(x))
> +#define cpu_to_le32(x)		((uint32_t)BSWAP32(x))
> +#define cpu_to_le64(x)		((uint64_t)BSWAP64(x))
> +
> +#define le16_to_cpu(x)		((uint16_t)BSWAP16(x))
> +#define le32_to_cpu(x)		((uint32_t)BSWAP32(x))
> +#define le64_to_cpu(x)		((uint64_t)BSWAP64(x))
> +#endif
> +
> +#endif /* __SBI_BYTEORDER_H__ */
> -- 
> 2.34.1
> 
> 
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