mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-25 10:19:47 +00:00
![Nikolay Borisov](/assets/img/avatar_default.png)
This function returns a string with the currently in-use implementation of the crc32c algorithm, i.e crc32c-generic (for unoptimised, generic implementation) or crc32c-intel for the sse optimised version. This will be used by btrfs. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> [ use crypto_shash_driver_name as suggested by Herbert ] Signed-off-by: David Sterba <dsterba@suse.com>
86 lines
2.2 KiB
C
86 lines
2.2 KiB
C
/*
|
|
* CRC32C
|
|
*@Article{castagnoli-crc,
|
|
* author = { Guy Castagnoli and Stefan Braeuer and Martin Herrman},
|
|
* title = {{Optimization of Cyclic Redundancy-Check Codes with 24
|
|
* and 32 Parity Bits}},
|
|
* journal = IEEE Transactions on Communication,
|
|
* year = {1993},
|
|
* volume = {41},
|
|
* number = {6},
|
|
* pages = {},
|
|
* month = {June},
|
|
*}
|
|
* Used by the iSCSI driver, possibly others, and derived from the
|
|
* the iscsi-crc.c module of the linux-iscsi driver at
|
|
* http://linux-iscsi.sourceforge.net.
|
|
*
|
|
* Following the example of lib/crc32, this function is intended to be
|
|
* flexible and useful for all users. Modules that currently have their
|
|
* own crc32c, but hopefully may be able to use this one are:
|
|
* net/sctp (please add all your doco to here if you change to
|
|
* use this one!)
|
|
* <endoflist>
|
|
*
|
|
* Copyright (c) 2004 Cisco Systems, Inc.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU General Public License as published by the Free
|
|
* Software Foundation; either version 2 of the License, or (at your option)
|
|
* any later version.
|
|
*
|
|
*/
|
|
|
|
#include <crypto/hash.h>
|
|
#include <linux/err.h>
|
|
#include <linux/init.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/crc32c.h>
|
|
|
|
static struct crypto_shash *tfm;
|
|
|
|
u32 crc32c(u32 crc, const void *address, unsigned int length)
|
|
{
|
|
SHASH_DESC_ON_STACK(shash, tfm);
|
|
u32 ret, *ctx = (u32 *)shash_desc_ctx(shash);
|
|
int err;
|
|
|
|
shash->tfm = tfm;
|
|
shash->flags = 0;
|
|
*ctx = crc;
|
|
|
|
err = crypto_shash_update(shash, address, length);
|
|
BUG_ON(err);
|
|
|
|
ret = *ctx;
|
|
barrier_data(ctx);
|
|
return ret;
|
|
}
|
|
|
|
EXPORT_SYMBOL(crc32c);
|
|
|
|
static int __init libcrc32c_mod_init(void)
|
|
{
|
|
tfm = crypto_alloc_shash("crc32c", 0, 0);
|
|
return PTR_ERR_OR_ZERO(tfm);
|
|
}
|
|
|
|
static void __exit libcrc32c_mod_fini(void)
|
|
{
|
|
crypto_free_shash(tfm);
|
|
}
|
|
|
|
const char *crc32c_impl(void)
|
|
{
|
|
return crypto_shash_driver_name(tfm);
|
|
}
|
|
EXPORT_SYMBOL(crc32c_impl);
|
|
|
|
module_init(libcrc32c_mod_init);
|
|
module_exit(libcrc32c_mod_fini);
|
|
|
|
MODULE_AUTHOR("Clay Haapala <chaapala@cisco.com>");
|
|
MODULE_DESCRIPTION("CRC32c (Castagnoli) calculations");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_SOFTDEP("pre: crc32c");
|