65 lines
1.5 KiB
C
65 lines
1.5 KiB
C
|
/*
|
||
|
|
* T10 Data Integrity Field CRC16 calculation
|
||
|
|
*
|
||
|
|
* Copyright (c) 2007 Oracle Corporation. All rights reserved.
|
||
|
|
* Written by Martin K. Petersen <martin.petersen@oracle.com>
|
||
|
|
*
|
||
|
|
* This source code is licensed under the GNU General Public License,
|
||
|
|
* Version 2. See the file COPYING for more details.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/types.h>
|
||
|
|
#include <linux/module.h>
|
||
|
|
#include <linux/crc-t10dif.h>
|
||
|
|
#include <linux/err.h>
|
||
|
|
#include <linux/init.h>
|
||
|
|
#include <crypto/hash.h>
|
||
|
|
#include <linux/static_key.h>
|
||
|
|
|
||
|
|
static struct crypto_shash *crct10dif_tfm;
|
||
|
|
static struct static_key crct10dif_fallback __read_mostly;
|
||
|
|
|
||
|
|
__u16 crc_t10dif(const unsigned char *buffer, size_t len)
|
||
|
|
{
|
||
|
|
struct {
|
||
|
|
struct shash_desc shash;
|
||
|
|
char ctx[2];
|
||
|
|
} desc;
|
||
|
|
int err;
|
||
|
|
|
||
|
|
if (static_key_false(&crct10dif_fallback))
|
||
|
|
return crc_t10dif_generic(0, buffer, len);
|
||
|
|
|
||
|
|
desc.shash.tfm = crct10dif_tfm;
|
||
|
|
desc.shash.flags = 0;
|
||
|
|
*(__u16 *)desc.ctx = 0;
|
||
|
|
|
||
|
|
err = crypto_shash_update(&desc.shash, buffer, len);
|
||
|
|
BUG_ON(err);
|
||
|
|
|
||
|
|
return *(__u16 *)desc.ctx;
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL(crc_t10dif);
|
||
|
|
|
||
|
|
static int __init crc_t10dif_mod_init(void)
|
||
|
|
{
|
||
|
|
crct10dif_tfm = crypto_alloc_shash("crct10dif", 0, 0);
|
||
|
|
if (IS_ERR(crct10dif_tfm)) {
|
||
|
|
static_key_slow_inc(&crct10dif_fallback);
|
||
|
|
crct10dif_tfm = NULL;
|
||
|
|
}
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static void __exit crc_t10dif_mod_fini(void)
|
||
|
|
{
|
||
|
|
crypto_free_shash(crct10dif_tfm);
|
||
|
|
}
|
||
|
|
|
||
|
|
module_init(crc_t10dif_mod_init);
|
||
|
|
module_exit(crc_t10dif_mod_fini);
|
||
|
|
|
||
|
|
MODULE_DESCRIPTION("T10 DIF CRC calculation");
|
||
|
|
MODULE_LICENSE("GPL");
|
||
|
|
MODULE_SOFTDEP("pre: crct10dif");
|