50 строки
1.8 KiB
C
50 строки
1.8 KiB
C
|
/* SPDX-License-Identifier: BSD-3-Clause
|
||
|
|
* Copyright (c) 2016-2018, NXP Semiconductors
|
||
|
|
* 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
|