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1/* SPDX-License-Identifier: BSD-3-Clause2 * Copyright 2016-2018 NXP3 * Copyright (c) 2018-2019, Vladimir Oltean <olteanv@gmail.com>4 */5#ifndef _LINUX_PACKING_H6#define _LINUX_PACKING_H7 8#include <linux/types.h>9#include <linux/bitops.h>10 11#define QUIRK_MSB_ON_THE_RIGHT BIT(0)12#define QUIRK_LITTLE_ENDIAN BIT(1)13#define QUIRK_LSW32_IS_FIRST BIT(2)14 15enum packing_op {16 PACK,17 UNPACK,18};19 20/**21 * packing - Convert numbers (currently u64) between a packed and an unpacked22 * format. Unpacked means laid out in memory in the CPU's native23 * understanding of integers, while packed means anything else that24 * requires translation.25 *26 * @pbuf: Pointer to a buffer holding the packed value.27 * @uval: Pointer to an u64 holding the unpacked value.28 * @startbit: The index (in logical notation, compensated for quirks) where29 * the packed value starts within pbuf. Must be larger than, or30 * equal to, endbit.31 * @endbit: The index (in logical notation, compensated for quirks) where32 * the packed value ends within pbuf. Must be smaller than, or equal33 * to, startbit.34 * @op: If PACK, then uval will be treated as const pointer and copied (packed)35 * into pbuf, between startbit and endbit.36 * If UNPACK, then pbuf will be treated as const pointer and the logical37 * value between startbit and endbit will be copied (unpacked) to uval.38 * @quirks: A bit mask of QUIRK_LITTLE_ENDIAN, QUIRK_LSW32_IS_FIRST and39 * QUIRK_MSB_ON_THE_RIGHT.40 *41 * Return: 0 on success, EINVAL or ERANGE if called incorrectly. Assuming42 * correct usage, return code may be discarded.43 * If op is PACK, pbuf is modified.44 * If op is UNPACK, uval is modified.45 */46int packing(void *pbuf, u64 *uval, int startbit, int endbit, size_t pbuflen,47 enum packing_op op, u8 quirks);48 49#endif50