1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-or-later
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * CRC32C
4*4882a593Smuzhiyun *@Article{castagnoli-crc,
5*4882a593Smuzhiyun * author = { Guy Castagnoli and Stefan Braeuer and Martin Herrman},
6*4882a593Smuzhiyun * title = {{Optimization of Cyclic Redundancy-Check Codes with 24
7*4882a593Smuzhiyun * and 32 Parity Bits}},
8*4882a593Smuzhiyun * journal = IEEE Transactions on Communication,
9*4882a593Smuzhiyun * year = {1993},
10*4882a593Smuzhiyun * volume = {41},
11*4882a593Smuzhiyun * number = {6},
12*4882a593Smuzhiyun * pages = {},
13*4882a593Smuzhiyun * month = {June},
14*4882a593Smuzhiyun *}
15*4882a593Smuzhiyun * Used by the iSCSI driver, possibly others, and derived from
16*4882a593Smuzhiyun * the iscsi-crc.c module of the linux-iscsi driver at
17*4882a593Smuzhiyun * http://linux-iscsi.sourceforge.net.
18*4882a593Smuzhiyun *
19*4882a593Smuzhiyun * Following the example of lib/crc32, this function is intended to be
20*4882a593Smuzhiyun * flexible and useful for all users. Modules that currently have their
21*4882a593Smuzhiyun * own crc32c, but hopefully may be able to use this one are:
22*4882a593Smuzhiyun * net/sctp (please add all your doco to here if you change to
23*4882a593Smuzhiyun * use this one!)
24*4882a593Smuzhiyun * <endoflist>
25*4882a593Smuzhiyun *
26*4882a593Smuzhiyun * Copyright (c) 2004 Cisco Systems, Inc.
27*4882a593Smuzhiyun */
28*4882a593Smuzhiyun
29*4882a593Smuzhiyun #include <crypto/hash.h>
30*4882a593Smuzhiyun #include <linux/err.h>
31*4882a593Smuzhiyun #include <linux/init.h>
32*4882a593Smuzhiyun #include <linux/kernel.h>
33*4882a593Smuzhiyun #include <linux/module.h>
34*4882a593Smuzhiyun #include <linux/crc32c.h>
35*4882a593Smuzhiyun
36*4882a593Smuzhiyun static struct crypto_shash *tfm;
37*4882a593Smuzhiyun
crc32c(u32 crc,const void * address,unsigned int length)38*4882a593Smuzhiyun u32 crc32c(u32 crc, const void *address, unsigned int length)
39*4882a593Smuzhiyun {
40*4882a593Smuzhiyun SHASH_DESC_ON_STACK(shash, tfm);
41*4882a593Smuzhiyun u32 ret, *ctx = (u32 *)shash_desc_ctx(shash);
42*4882a593Smuzhiyun int err;
43*4882a593Smuzhiyun
44*4882a593Smuzhiyun shash->tfm = tfm;
45*4882a593Smuzhiyun *ctx = crc;
46*4882a593Smuzhiyun
47*4882a593Smuzhiyun err = crypto_shash_update(shash, address, length);
48*4882a593Smuzhiyun BUG_ON(err);
49*4882a593Smuzhiyun
50*4882a593Smuzhiyun ret = *ctx;
51*4882a593Smuzhiyun barrier_data(ctx);
52*4882a593Smuzhiyun return ret;
53*4882a593Smuzhiyun }
54*4882a593Smuzhiyun
55*4882a593Smuzhiyun EXPORT_SYMBOL(crc32c);
56*4882a593Smuzhiyun
libcrc32c_mod_init(void)57*4882a593Smuzhiyun static int __init libcrc32c_mod_init(void)
58*4882a593Smuzhiyun {
59*4882a593Smuzhiyun tfm = crypto_alloc_shash("crc32c", 0, 0);
60*4882a593Smuzhiyun return PTR_ERR_OR_ZERO(tfm);
61*4882a593Smuzhiyun }
62*4882a593Smuzhiyun
libcrc32c_mod_fini(void)63*4882a593Smuzhiyun static void __exit libcrc32c_mod_fini(void)
64*4882a593Smuzhiyun {
65*4882a593Smuzhiyun crypto_free_shash(tfm);
66*4882a593Smuzhiyun }
67*4882a593Smuzhiyun
crc32c_impl(void)68*4882a593Smuzhiyun const char *crc32c_impl(void)
69*4882a593Smuzhiyun {
70*4882a593Smuzhiyun return crypto_shash_driver_name(tfm);
71*4882a593Smuzhiyun }
72*4882a593Smuzhiyun EXPORT_SYMBOL(crc32c_impl);
73*4882a593Smuzhiyun
74*4882a593Smuzhiyun module_init(libcrc32c_mod_init);
75*4882a593Smuzhiyun module_exit(libcrc32c_mod_fini);
76*4882a593Smuzhiyun
77*4882a593Smuzhiyun MODULE_AUTHOR("Clay Haapala <chaapala@cisco.com>");
78*4882a593Smuzhiyun MODULE_DESCRIPTION("CRC32c (Castagnoli) calculations");
79*4882a593Smuzhiyun MODULE_LICENSE("GPL");
80*4882a593Smuzhiyun MODULE_SOFTDEP("pre: crc32c");
81