Messages in this thread | | | Subject | Re: [PATCH v3 1/3] lib: add crc64 calculation routines | From | Andy Shevchenko <> | Date | Tue, 17 Jul 2018 18:43:05 +0300 |
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On Tue, 2018-07-17 at 22:55 +0800, Coly Li wrote: > This patch adds the re-write crc64 calculation routines for Linux > kernel. > The CRC64 polynomical arithmetic follows ECMA-182 specification, > inspired > by CRC paper of Dr. Ross N. Williams > (see http://www.ross.net/crc/download/crc_v3.txt) and other public > domain > implementations. > > All the changes work in this way, > - When Linux kernel is built, host program lib/gen_crc64table.c will > be > compiled to lib/gen_crc64table and executed. > - The output of gen_crc64table execution is an array called as lookup > table (a.k.a POLY 0x42f0e1eba9ea369) which contain 256 64bits-long > numbers, this talbe is dumped into header file lib/crc64table.h. > - Then the header file is included by lib/crc64.c for normal 64bit crc > calculation. > - Function declaration of the crc64 calculation routines is placed in > include/linux/crc64.h
Thanks for an update! My comments below.
> Co-developed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
As required by coding style this tag should be accompanied with SoB of co-developer(s).
> +u64 __pure crc64_update(u64 crc, const void *_p, size_t len);
For sake of consistency I would name _len as well.
> + * Normal 64bit CRC calculation.
I think 64-bit form is slightly better and more often
$ git grep -n -w 64bit | wc -l 809
$ git grep -n -w 64-bit | wc -l 2957
> + * crc64table[256] is the lookup table of a table-driver 64bit CRC
Ditto.
> + * Copyright 2018 SUSE Linux. > + * Author: Coly Li <colyli@suse.de>
> + *
This (blank comment) line is not needed.
> +u64 __pure crc64_update(u64 crc, const void *_p, size_t len)
_len ?
> + * Copyright 2018 SUSE Linux. > + * Author: Coly Li <colyli@suse.de>
> + *
Not needed line.
> +#include <inttypes.h> > +#include <stdio.h>
+ blank line? Would separate groups of headers logically.
> +#include <linux/swab.h>
> +static int64_t crc64_table[256] = {0,};
I guess {0} would work as well (no comma).
> + printf("#include <uapi/linux/types.h>\n"); > + printf("#include <linux/cache.h>\n\n");
Do wee need these? CRC32 case seems fine without.
-- Andy Shevchenko <andriy.shevchenko@linux.intel.com> Intel Finland Oy
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