1/*
 2 * T10 Data Integrity Field CRC16 calculation
 3 *
 4 * Copyright (c) 2007 Oracle Corporation.  All rights reserved.
 5 * Written by Martin K. Petersen <martin.petersen@oracle.com>
 6 *
 7 * This source code is licensed under the GNU General Public License,
 8 * Version 2. See the file COPYING for more details.
 9 */
10
11#include <linux/types.h>
12#include <linux/module.h>
13#include <linux/crc-t10dif.h>
14#include <linux/err.h>
15#include <linux/init.h>
16#include <crypto/hash.h>
17#include <linux/static_key.h>
18
19static struct crypto_shash *crct10dif_tfm;
20static struct static_key crct10dif_fallback __read_mostly;
21
22__u16 crc_t10dif(const unsigned char *buffer, size_t len)
23{
24	struct {
25		struct shash_desc shash;
26		char ctx[2];
27	} desc;
28	int err;
29
30	if (static_key_false(&crct10dif_fallback))
31		return crc_t10dif_generic(0, buffer, len);
32
33	desc.shash.tfm = crct10dif_tfm;
34	desc.shash.flags = 0;
35	*(__u16 *)desc.ctx = 0;
36
37	err = crypto_shash_update(&desc.shash, buffer, len);
38	BUG_ON(err);
39
40	return *(__u16 *)desc.ctx;
 
 
 
 
 
 
41}
42EXPORT_SYMBOL(crc_t10dif);
43
44static int __init crc_t10dif_mod_init(void)
45{
46	crct10dif_tfm = crypto_alloc_shash("crct10dif", 0, 0);
47	if (IS_ERR(crct10dif_tfm)) {
48		static_key_slow_inc(&crct10dif_fallback);
49		crct10dif_tfm = NULL;
50	}
51	return 0;
52}
53
54static void __exit crc_t10dif_mod_fini(void)
55{
56	crypto_free_shash(crct10dif_tfm);
57}
58
59module_init(crc_t10dif_mod_init);
60module_exit(crc_t10dif_mod_fini);
61
62MODULE_DESCRIPTION("T10 DIF CRC calculation");
63MODULE_LICENSE("GPL");
64MODULE_SOFTDEP("pre: crct10dif");

 1/*
 2 * T10 Data Integrity Field CRC16 calculation
 3 *
 4 * Copyright (c) 2007 Oracle Corporation.  All rights reserved.
 5 * Written by Martin K. Petersen <martin.petersen@oracle.com>
 6 *
 7 * This source code is licensed under the GNU General Public License,
 8 * Version 2. See the file COPYING for more details.
 9 */
10
11#include <linux/types.h>
12#include <linux/module.h>
13#include <linux/crc-t10dif.h>
14#include <linux/err.h>
15#include <linux/init.h>
16#include <crypto/hash.h>
17#include <linux/static_key.h>
18
19static struct crypto_shash *crct10dif_tfm;
20static struct static_key crct10dif_fallback __read_mostly;
21
22__u16 crc_t10dif_update(__u16 crc, const unsigned char *buffer, size_t len)
23{
24	struct {
25		struct shash_desc shash;
26		char ctx[2];
27	} desc;
28	int err;
29
30	if (static_key_false(&crct10dif_fallback))
31		return crc_t10dif_generic(crc, buffer, len);
32
33	desc.shash.tfm = crct10dif_tfm;
34	desc.shash.flags = 0;
35	*(__u16 *)desc.ctx = crc;
36
37	err = crypto_shash_update(&desc.shash, buffer, len);
38	BUG_ON(err);
39
40	return *(__u16 *)desc.ctx;
41}
42EXPORT_SYMBOL(crc_t10dif_update);
43
44__u16 crc_t10dif(const unsigned char *buffer, size_t len)
45{
46	return crc_t10dif_update(0, buffer, len);
47}
48EXPORT_SYMBOL(crc_t10dif);
49
50static int __init crc_t10dif_mod_init(void)
51{
52	crct10dif_tfm = crypto_alloc_shash("crct10dif", 0, 0);
53	if (IS_ERR(crct10dif_tfm)) {
54		static_key_slow_inc(&crct10dif_fallback);
55		crct10dif_tfm = NULL;
56	}
57	return 0;
58}
59
60static void __exit crc_t10dif_mod_fini(void)
61{
62	crypto_free_shash(crct10dif_tfm);
63}
64
65module_init(crc_t10dif_mod_init);
66module_exit(crc_t10dif_mod_fini);
67
68MODULE_DESCRIPTION("T10 DIF CRC calculation");
69MODULE_LICENSE("GPL");
70MODULE_SOFTDEP("pre: crct10dif");