2 * Using hardware provided CRC32 instruction to accelerate the CRC32 disposal.
3 * CRC32C polynomial:0x1EDC6F41(BE)/0x82F63B78(LE)
4 * CRC32 is a new instruction in Intel SSE4.2, the reference can be found at:
5 * http://www.intel.com/products/processor/manuals/
6 * Intel(R) 64 and IA-32 Architectures Software Developer's Manual
7 * Volume 2A: Instruction Set Reference, A-M
9 * Copyright (C) 2008 Intel Corporation
10 * Authors: Austin Zhang <austin_zhang@linux.intel.com>
11 * Kent Liu <kent.liu@intel.com>
13 * This program is free software; you can redistribute it and/or modify it
14 * under the terms and conditions of the GNU General Public License,
15 * version 2, as published by the Free Software Foundation.
17 * This program is distributed in the hope it will be useful, but WITHOUT
18 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
19 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
22 * You should have received a copy of the GNU General Public License along with
23 * this program; if not, write to the Free Software Foundation, Inc.,
24 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
27 #include <linux/init.h>
28 #include <linux/module.h>
29 #include <linux/string.h>
30 #include <linux/kernel.h>
31 #include <crypto/internal/hash.h>
33 #include <asm/cpufeature.h>
34 #include <asm/cpu_device_id.h>
36 #define CHKSUM_BLOCK_SIZE 1
37 #define CHKSUM_DIGEST_SIZE 4
39 #define SCALE_F sizeof(unsigned long)
42 #define REX_PRE "0x48, "
47 static u32 crc32c_intel_le_hw_byte(u32 crc, unsigned char const *data, size_t length)
51 ".byte 0xf2, 0xf, 0x38, 0xf0, 0xf1"
61 static u32 __pure crc32c_intel_le_hw(u32 crc, unsigned char const *p, size_t len)
63 unsigned int iquotient = len / SCALE_F;
64 unsigned int iremainder = len % SCALE_F;
65 unsigned long *ptmp = (unsigned long *)p;
69 ".byte 0xf2, " REX_PRE "0xf, 0x38, 0xf1, 0xf1;"
77 crc = crc32c_intel_le_hw_byte(crc, (unsigned char *)ptmp,
84 * Setting the seed allows arbitrary accumulators and flexible XOR policy
85 * If your algorithm starts with ~0, then XOR with ~0 before you set
88 static int crc32c_intel_setkey(struct crypto_shash *hash, const u8 *key,
91 u32 *mctx = crypto_shash_ctx(hash);
93 if (keylen != sizeof(u32)) {
94 crypto_shash_set_flags(hash, CRYPTO_TFM_RES_BAD_KEY_LEN);
97 *mctx = le32_to_cpup((__le32 *)key);
101 static int crc32c_intel_init(struct shash_desc *desc)
103 u32 *mctx = crypto_shash_ctx(desc->tfm);
104 u32 *crcp = shash_desc_ctx(desc);
111 static int crc32c_intel_update(struct shash_desc *desc, const u8 *data,
114 u32 *crcp = shash_desc_ctx(desc);
116 *crcp = crc32c_intel_le_hw(*crcp, data, len);
120 static int __crc32c_intel_finup(u32 *crcp, const u8 *data, unsigned int len,
123 *(__le32 *)out = ~cpu_to_le32(crc32c_intel_le_hw(*crcp, data, len));
127 static int crc32c_intel_finup(struct shash_desc *desc, const u8 *data,
128 unsigned int len, u8 *out)
130 return __crc32c_intel_finup(shash_desc_ctx(desc), data, len, out);
133 static int crc32c_intel_final(struct shash_desc *desc, u8 *out)
135 u32 *crcp = shash_desc_ctx(desc);
137 *(__le32 *)out = ~cpu_to_le32p(crcp);
141 static int crc32c_intel_digest(struct shash_desc *desc, const u8 *data,
142 unsigned int len, u8 *out)
144 return __crc32c_intel_finup(crypto_shash_ctx(desc->tfm), data, len,
148 static int crc32c_intel_cra_init(struct crypto_tfm *tfm)
150 u32 *key = crypto_tfm_ctx(tfm);
157 static struct shash_alg alg = {
158 .setkey = crc32c_intel_setkey,
159 .init = crc32c_intel_init,
160 .update = crc32c_intel_update,
161 .final = crc32c_intel_final,
162 .finup = crc32c_intel_finup,
163 .digest = crc32c_intel_digest,
164 .descsize = sizeof(u32),
165 .digestsize = CHKSUM_DIGEST_SIZE,
167 .cra_name = "crc32c",
168 .cra_driver_name = "crc32c-intel",
170 .cra_blocksize = CHKSUM_BLOCK_SIZE,
171 .cra_ctxsize = sizeof(u32),
172 .cra_module = THIS_MODULE,
173 .cra_init = crc32c_intel_cra_init,
177 static const struct x86_cpu_id crc32c_cpu_id[] = {
178 X86_FEATURE_MATCH(X86_FEATURE_XMM4_2),
181 MODULE_DEVICE_TABLE(x86cpu, crc32c_cpu_id);
183 static int __init crc32c_intel_mod_init(void)
185 if (!x86_match_cpu(crc32c_cpu_id))
187 return crypto_register_shash(&alg);
190 static void __exit crc32c_intel_mod_fini(void)
192 crypto_unregister_shash(&alg);
195 module_init(crc32c_intel_mod_init);
196 module_exit(crc32c_intel_mod_fini);
198 MODULE_AUTHOR("Austin Zhang <austin.zhang@intel.com>, Kent Liu <kent.liu@intel.com>");
199 MODULE_DESCRIPTION("CRC32c (Castagnoli) optimization using Intel Hardware.");
200 MODULE_LICENSE("GPL");
202 MODULE_ALIAS("crc32c");
203 MODULE_ALIAS("crc32c-intel");