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8cb51ba8 AZ |
1 | /* |
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 | |
8 | * | |
1c06da81 KL |
9 | * Copyright (C) 2008 Intel Corporation |
10 | * Authors: Austin Zhang <austin_zhang@linux.intel.com> | |
11 | * Kent Liu <kent.liu@intel.com> | |
8cb51ba8 AZ |
12 | * |
13 | * This program is free software; you can redistribute it and/or modify it | |
1c06da81 KL |
14 | * under the terms and conditions of the GNU General Public License, |
15 | * version 2, as published by the Free Software Foundation. | |
16 | * | |
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 | |
20 | * more details. | |
21 | * | |
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. | |
8cb51ba8 AZ |
25 | * |
26 | */ | |
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> | |
32 | ||
33 | #include <asm/cpufeature.h> | |
34 | ||
35 | #define CHKSUM_BLOCK_SIZE 1 | |
36 | #define CHKSUM_DIGEST_SIZE 4 | |
37 | ||
38 | #define SCALE_F sizeof(unsigned long) | |
39 | ||
40 | #ifdef CONFIG_X86_64 | |
41 | #define REX_PRE "0x48, " | |
42 | #else | |
43 | #define REX_PRE | |
44 | #endif | |
45 | ||
46 | static u32 crc32c_intel_le_hw_byte(u32 crc, unsigned char const *data, size_t length) | |
47 | { | |
48 | while (length--) { | |
49 | __asm__ __volatile__( | |
50 | ".byte 0xf2, 0xf, 0x38, 0xf0, 0xf1" | |
51 | :"=S"(crc) | |
52 | :"0"(crc), "c"(*data) | |
53 | ); | |
54 | data++; | |
55 | } | |
56 | ||
57 | return crc; | |
58 | } | |
59 | ||
60 | static u32 __pure crc32c_intel_le_hw(u32 crc, unsigned char const *p, size_t len) | |
61 | { | |
62 | unsigned int iquotient = len / SCALE_F; | |
63 | unsigned int iremainder = len % SCALE_F; | |
64 | unsigned long *ptmp = (unsigned long *)p; | |
65 | ||
66 | while (iquotient--) { | |
67 | __asm__ __volatile__( | |
68 | ".byte 0xf2, " REX_PRE "0xf, 0x38, 0xf1, 0xf1;" | |
69 | :"=S"(crc) | |
70 | :"0"(crc), "c"(*ptmp) | |
71 | ); | |
72 | ptmp++; | |
73 | } | |
74 | ||
75 | if (iremainder) | |
76 | crc = crc32c_intel_le_hw_byte(crc, (unsigned char *)ptmp, | |
77 | iremainder); | |
78 | ||
79 | return crc; | |
80 | } | |
81 | ||
82 | /* | |
83 | * Setting the seed allows arbitrary accumulators and flexible XOR policy | |
84 | * If your algorithm starts with ~0, then XOR with ~0 before you set | |
85 | * the seed. | |
86 | */ | |
b7e8bdad | 87 | static int crc32c_intel_setkey(struct crypto_shash *hash, const u8 *key, |
8cb51ba8 AZ |
88 | unsigned int keylen) |
89 | { | |
b7e8bdad | 90 | u32 *mctx = crypto_shash_ctx(hash); |
8cb51ba8 AZ |
91 | |
92 | if (keylen != sizeof(u32)) { | |
b7e8bdad | 93 | crypto_shash_set_flags(hash, CRYPTO_TFM_RES_BAD_KEY_LEN); |
8cb51ba8 AZ |
94 | return -EINVAL; |
95 | } | |
96 | *mctx = le32_to_cpup((__le32 *)key); | |
97 | return 0; | |
98 | } | |
99 | ||
b7e8bdad | 100 | static int crc32c_intel_init(struct shash_desc *desc) |
8cb51ba8 | 101 | { |
b7e8bdad HX |
102 | u32 *mctx = crypto_shash_ctx(desc->tfm); |
103 | u32 *crcp = shash_desc_ctx(desc); | |
8cb51ba8 AZ |
104 | |
105 | *crcp = *mctx; | |
106 | ||
107 | return 0; | |
108 | } | |
109 | ||
b7e8bdad HX |
110 | static int crc32c_intel_update(struct shash_desc *desc, const u8 *data, |
111 | unsigned int len) | |
8cb51ba8 | 112 | { |
b7e8bdad | 113 | u32 *crcp = shash_desc_ctx(desc); |
8cb51ba8 | 114 | |
b7e8bdad | 115 | *crcp = crc32c_intel_le_hw(*crcp, data, len); |
8cb51ba8 AZ |
116 | return 0; |
117 | } | |
118 | ||
b7e8bdad HX |
119 | static int __crc32c_intel_finup(u32 *crcp, const u8 *data, unsigned int len, |
120 | u8 *out) | |
8cb51ba8 | 121 | { |
b7e8bdad | 122 | *(__le32 *)out = ~cpu_to_le32(crc32c_intel_le_hw(*crcp, data, len)); |
8cb51ba8 AZ |
123 | return 0; |
124 | } | |
125 | ||
b7e8bdad HX |
126 | static int crc32c_intel_finup(struct shash_desc *desc, const u8 *data, |
127 | unsigned int len, u8 *out) | |
8cb51ba8 | 128 | { |
b7e8bdad HX |
129 | return __crc32c_intel_finup(shash_desc_ctx(desc), data, len, out); |
130 | } | |
8cb51ba8 | 131 | |
b7e8bdad HX |
132 | static int crc32c_intel_final(struct shash_desc *desc, u8 *out) |
133 | { | |
134 | u32 *crcp = shash_desc_ctx(desc); | |
8cb51ba8 | 135 | |
b7e8bdad | 136 | *(__le32 *)out = ~cpu_to_le32p(crcp); |
8cb51ba8 AZ |
137 | return 0; |
138 | } | |
139 | ||
b7e8bdad HX |
140 | static int crc32c_intel_digest(struct shash_desc *desc, const u8 *data, |
141 | unsigned int len, u8 *out) | |
142 | { | |
143 | return __crc32c_intel_finup(crypto_shash_ctx(desc->tfm), data, len, | |
144 | out); | |
145 | } | |
146 | ||
8cb51ba8 AZ |
147 | static int crc32c_intel_cra_init(struct crypto_tfm *tfm) |
148 | { | |
149 | u32 *key = crypto_tfm_ctx(tfm); | |
150 | ||
151 | *key = ~0; | |
152 | ||
8cb51ba8 AZ |
153 | return 0; |
154 | } | |
155 | ||
b7e8bdad HX |
156 | static struct shash_alg alg = { |
157 | .setkey = crc32c_intel_setkey, | |
158 | .init = crc32c_intel_init, | |
159 | .update = crc32c_intel_update, | |
160 | .final = crc32c_intel_final, | |
161 | .finup = crc32c_intel_finup, | |
162 | .digest = crc32c_intel_digest, | |
163 | .descsize = sizeof(u32), | |
164 | .digestsize = CHKSUM_DIGEST_SIZE, | |
165 | .base = { | |
166 | .cra_name = "crc32c", | |
167 | .cra_driver_name = "crc32c-intel", | |
168 | .cra_priority = 200, | |
169 | .cra_blocksize = CHKSUM_BLOCK_SIZE, | |
170 | .cra_ctxsize = sizeof(u32), | |
171 | .cra_module = THIS_MODULE, | |
172 | .cra_init = crc32c_intel_cra_init, | |
8cb51ba8 AZ |
173 | } |
174 | }; | |
175 | ||
176 | ||
177 | static int __init crc32c_intel_mod_init(void) | |
178 | { | |
179 | if (cpu_has_xmm4_2) | |
b7e8bdad | 180 | return crypto_register_shash(&alg); |
8cb51ba8 AZ |
181 | else |
182 | return -ENODEV; | |
183 | } | |
184 | ||
185 | static void __exit crc32c_intel_mod_fini(void) | |
186 | { | |
b7e8bdad | 187 | crypto_unregister_shash(&alg); |
8cb51ba8 AZ |
188 | } |
189 | ||
190 | module_init(crc32c_intel_mod_init); | |
191 | module_exit(crc32c_intel_mod_fini); | |
192 | ||
193 | MODULE_AUTHOR("Austin Zhang <austin.zhang@intel.com>, Kent Liu <kent.liu@intel.com>"); | |
194 | MODULE_DESCRIPTION("CRC32c (Castagnoli) optimization using Intel Hardware."); | |
195 | MODULE_LICENSE("GPL"); | |
196 | ||
197 | MODULE_ALIAS("crc32c"); | |
198 | MODULE_ALIAS("crc32c-intel"); |