/* SPDX-License-Identifier: BSD-3-Clause * Copyright 2016-2018 NXP * Copyright (c) 2018-2019, Vladimir Oltean <olteanv@gmail.com> */ #ifndef _LINUX_PACKING_H #define _LINUX_PACKING_H #include <linux/types.h> #include <linux/bitops.h> #define QUIRK_MSB_ON_THE_RIGHT BIT(0) #define QUIRK_LITTLE_ENDIAN BIT(1) #define QUIRK_LSW32_IS_FIRST BIT(2) enum packing_op { PACK, UNPACK, }; /** * packing - Convert numbers (currently u64) between a packed and an unpacked * format. Unpacked means laid out in memory in the CPU's native * understanding of integers, while packed means anything else that * requires translation. * * @pbuf: Pointer to a buffer holding the packed value. * @uval: Pointer to an u64 holding the unpacked value. * @startbit: The index (in logical notation, compensated for quirks) where * the packed value starts within pbuf. Must be larger than, or * equal to, endbit. * @endbit: The index (in logical notation, compensated for quirks) where * the packed value ends within pbuf. Must be smaller than, or equal * to, startbit. * @op: If PACK, then uval will be treated as const pointer and copied (packed) * into pbuf, between startbit and endbit. * If UNPACK, then pbuf will be treated as const pointer and the logical * value between startbit and endbit will be copied (unpacked) to uval. * @quirks: A bit mask of QUIRK_LITTLE_ENDIAN, QUIRK_LSW32_IS_FIRST and * QUIRK_MSB_ON_THE_RIGHT. * * Return: 0 on success, EINVAL or ERANGE if called incorrectly. Assuming * correct usage, return code may be discarded. * If op is PACK, pbuf is modified. * If op is UNPACK, uval is modified. */ int packing(void *pbuf, u64 *uval, int startbit, int endbit, size_t pbuflen, enum packing_op op, u8 quirks); #endif