mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-29 23:53:32 +00:00
0e0c12316d
The crc64_be() is declared in <linux/crc64.h> so include this where the symbol is defined to avoid the following warning: lib/crc64.c:43:12: warning: symbol 'crc64_be' was not declared. Should it be static? Signed-off-by: Ben Dooks (Codethink) <ben.dooks@codethink.co.uk> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
57 lines
1.8 KiB
C
57 lines
1.8 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Normal 64-bit CRC calculation.
|
|
*
|
|
* This is a basic crc64 implementation following ECMA-182 specification,
|
|
* which can be found from,
|
|
* http://www.ecma-international.org/publications/standards/Ecma-182.htm
|
|
*
|
|
* Dr. Ross N. Williams has a great document to introduce the idea of CRC
|
|
* algorithm, here the CRC64 code is also inspired by the table-driven
|
|
* algorithm and detail example from this paper. This paper can be found
|
|
* from,
|
|
* http://www.ross.net/crc/download/crc_v3.txt
|
|
*
|
|
* crc64table[256] is the lookup table of a table-driven 64-bit CRC
|
|
* calculation, which is generated by gen_crc64table.c in kernel build
|
|
* time. The polynomial of crc64 arithmetic is from ECMA-182 specification
|
|
* as well, which is defined as,
|
|
*
|
|
* x^64 + x^62 + x^57 + x^55 + x^54 + x^53 + x^52 + x^47 + x^46 + x^45 +
|
|
* x^40 + x^39 + x^38 + x^37 + x^35 + x^33 + x^32 + x^31 + x^29 + x^27 +
|
|
* x^24 + x^23 + x^22 + x^21 + x^19 + x^17 + x^13 + x^12 + x^10 + x^9 +
|
|
* x^7 + x^4 + x + 1
|
|
*
|
|
* Copyright 2018 SUSE Linux.
|
|
* Author: Coly Li <colyli@suse.de>
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/types.h>
|
|
#include <linux/crc64.h>
|
|
#include "crc64table.h"
|
|
|
|
MODULE_DESCRIPTION("CRC64 calculations");
|
|
MODULE_LICENSE("GPL v2");
|
|
|
|
/**
|
|
* crc64_be - Calculate bitwise big-endian ECMA-182 CRC64
|
|
* @crc: seed value for computation. 0 or (u64)~0 for a new CRC calculation,
|
|
or the previous crc64 value if computing incrementally.
|
|
* @p: pointer to buffer over which CRC64 is run
|
|
* @len: length of buffer @p
|
|
*/
|
|
u64 __pure crc64_be(u64 crc, const void *p, size_t len)
|
|
{
|
|
size_t i, t;
|
|
|
|
const unsigned char *_p = p;
|
|
|
|
for (i = 0; i < len; i++) {
|
|
t = ((crc >> 56) ^ (*_p++)) & 0xFF;
|
|
crc = crc64table[t] ^ (crc << 8);
|
|
}
|
|
|
|
return crc;
|
|
}
|
|
EXPORT_SYMBOL_GPL(crc64_be);
|