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78c37d19 AB |
1 | /* GPL HEADER START |
2 | * | |
3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License version 2 only, | |
7 | * as published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, but | |
10 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
12 | * General Public License version 2 for more details (a copy is included | |
13 | * in the LICENSE file that accompanied this code). | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * version 2 along with this program; If not, see http://www.gnu.org/licenses | |
17 | * | |
18 | * Please visit http://www.xyratex.com/contact if you need additional | |
19 | * information or have any questions. | |
20 | * | |
21 | * GPL HEADER END | |
22 | */ | |
23 | ||
24 | /* | |
25 | * Copyright 2012 Xyratex Technology Limited | |
26 | * | |
27 | * Wrappers for kernel crypto shash api to pclmulqdq crc32 imlementation. | |
28 | */ | |
29 | #include <linux/init.h> | |
30 | #include <linux/module.h> | |
31 | #include <linux/string.h> | |
32 | #include <linux/kernel.h> | |
33 | #include <linux/crc32.h> | |
34 | #include <crypto/internal/hash.h> | |
f2abe0d7 | 35 | #include <crypto/internal/simd.h> |
78c37d19 | 36 | |
cd4d09ec | 37 | #include <asm/cpufeatures.h> |
78c37d19 | 38 | #include <asm/cpu_device_id.h> |
f2abe0d7 | 39 | #include <asm/simd.h> |
78c37d19 AB |
40 | |
41 | #define CHKSUM_BLOCK_SIZE 1 | |
42 | #define CHKSUM_DIGEST_SIZE 4 | |
43 | ||
44 | #define PCLMUL_MIN_LEN 64L /* minimum size of buffer | |
45 | * for crc32_pclmul_le_16 */ | |
46 | #define SCALE_F 16L /* size of xmm register */ | |
47 | #define SCALE_F_MASK (SCALE_F - 1) | |
48 | ||
49 | u32 crc32_pclmul_le_16(unsigned char const *buffer, size_t len, u32 crc32); | |
50 | ||
51 | static u32 __attribute__((pure)) | |
52 | crc32_pclmul_le(u32 crc, unsigned char const *p, size_t len) | |
53 | { | |
54 | unsigned int iquotient; | |
55 | unsigned int iremainder; | |
56 | unsigned int prealign; | |
57 | ||
f2abe0d7 | 58 | if (len < PCLMUL_MIN_LEN + SCALE_F_MASK || !crypto_simd_usable()) |
78c37d19 AB |
59 | return crc32_le(crc, p, len); |
60 | ||
61 | if ((long)p & SCALE_F_MASK) { | |
62 | /* align p to 16 byte */ | |
63 | prealign = SCALE_F - ((long)p & SCALE_F_MASK); | |
64 | ||
65 | crc = crc32_le(crc, p, prealign); | |
66 | len -= prealign; | |
67 | p = (unsigned char *)(((unsigned long)p + SCALE_F_MASK) & | |
68 | ~SCALE_F_MASK); | |
69 | } | |
70 | iquotient = len & (~SCALE_F_MASK); | |
71 | iremainder = len & SCALE_F_MASK; | |
72 | ||
73 | kernel_fpu_begin(); | |
74 | crc = crc32_pclmul_le_16(p, iquotient, crc); | |
75 | kernel_fpu_end(); | |
76 | ||
77 | if (iremainder) | |
78 | crc = crc32_le(crc, p + iquotient, iremainder); | |
79 | ||
80 | return crc; | |
81 | } | |
82 | ||
83 | static int crc32_pclmul_cra_init(struct crypto_tfm *tfm) | |
84 | { | |
85 | u32 *key = crypto_tfm_ctx(tfm); | |
86 | ||
87 | *key = 0; | |
88 | ||
89 | return 0; | |
90 | } | |
91 | ||
92 | static int crc32_pclmul_setkey(struct crypto_shash *hash, const u8 *key, | |
93 | unsigned int keylen) | |
94 | { | |
95 | u32 *mctx = crypto_shash_ctx(hash); | |
96 | ||
97 | if (keylen != sizeof(u32)) { | |
98 | crypto_shash_set_flags(hash, CRYPTO_TFM_RES_BAD_KEY_LEN); | |
99 | return -EINVAL; | |
100 | } | |
101 | *mctx = le32_to_cpup((__le32 *)key); | |
102 | return 0; | |
103 | } | |
104 | ||
105 | static int crc32_pclmul_init(struct shash_desc *desc) | |
106 | { | |
107 | u32 *mctx = crypto_shash_ctx(desc->tfm); | |
108 | u32 *crcp = shash_desc_ctx(desc); | |
109 | ||
110 | *crcp = *mctx; | |
111 | ||
112 | return 0; | |
113 | } | |
114 | ||
115 | static int crc32_pclmul_update(struct shash_desc *desc, const u8 *data, | |
116 | unsigned int len) | |
117 | { | |
118 | u32 *crcp = shash_desc_ctx(desc); | |
119 | ||
120 | *crcp = crc32_pclmul_le(*crcp, data, len); | |
121 | return 0; | |
122 | } | |
123 | ||
124 | /* No final XOR 0xFFFFFFFF, like crc32_le */ | |
125 | static int __crc32_pclmul_finup(u32 *crcp, const u8 *data, unsigned int len, | |
126 | u8 *out) | |
127 | { | |
128 | *(__le32 *)out = cpu_to_le32(crc32_pclmul_le(*crcp, data, len)); | |
129 | return 0; | |
130 | } | |
131 | ||
132 | static int crc32_pclmul_finup(struct shash_desc *desc, const u8 *data, | |
133 | unsigned int len, u8 *out) | |
134 | { | |
135 | return __crc32_pclmul_finup(shash_desc_ctx(desc), data, len, out); | |
136 | } | |
137 | ||
138 | static int crc32_pclmul_final(struct shash_desc *desc, u8 *out) | |
139 | { | |
140 | u32 *crcp = shash_desc_ctx(desc); | |
141 | ||
142 | *(__le32 *)out = cpu_to_le32p(crcp); | |
143 | return 0; | |
144 | } | |
145 | ||
146 | static int crc32_pclmul_digest(struct shash_desc *desc, const u8 *data, | |
147 | unsigned int len, u8 *out) | |
148 | { | |
149 | return __crc32_pclmul_finup(crypto_shash_ctx(desc->tfm), data, len, | |
150 | out); | |
151 | } | |
152 | ||
153 | static struct shash_alg alg = { | |
154 | .setkey = crc32_pclmul_setkey, | |
155 | .init = crc32_pclmul_init, | |
156 | .update = crc32_pclmul_update, | |
157 | .final = crc32_pclmul_final, | |
158 | .finup = crc32_pclmul_finup, | |
159 | .digest = crc32_pclmul_digest, | |
160 | .descsize = sizeof(u32), | |
161 | .digestsize = CHKSUM_DIGEST_SIZE, | |
162 | .base = { | |
163 | .cra_name = "crc32", | |
164 | .cra_driver_name = "crc32-pclmul", | |
165 | .cra_priority = 200, | |
a208fa8f | 166 | .cra_flags = CRYPTO_ALG_OPTIONAL_KEY, |
78c37d19 AB |
167 | .cra_blocksize = CHKSUM_BLOCK_SIZE, |
168 | .cra_ctxsize = sizeof(u32), | |
169 | .cra_module = THIS_MODULE, | |
170 | .cra_init = crc32_pclmul_cra_init, | |
171 | } | |
172 | }; | |
173 | ||
174 | static const struct x86_cpu_id crc32pclmul_cpu_id[] = { | |
175 | X86_FEATURE_MATCH(X86_FEATURE_PCLMULQDQ), | |
176 | {} | |
177 | }; | |
178 | MODULE_DEVICE_TABLE(x86cpu, crc32pclmul_cpu_id); | |
179 | ||
180 | ||
181 | static int __init crc32_pclmul_mod_init(void) | |
182 | { | |
183 | ||
184 | if (!x86_match_cpu(crc32pclmul_cpu_id)) { | |
185 | pr_info("PCLMULQDQ-NI instructions are not detected.\n"); | |
186 | return -ENODEV; | |
187 | } | |
188 | return crypto_register_shash(&alg); | |
189 | } | |
190 | ||
191 | static void __exit crc32_pclmul_mod_fini(void) | |
192 | { | |
193 | crypto_unregister_shash(&alg); | |
194 | } | |
195 | ||
196 | module_init(crc32_pclmul_mod_init); | |
197 | module_exit(crc32_pclmul_mod_fini); | |
198 | ||
199 | MODULE_AUTHOR("Alexander Boyko <alexander_boyko@xyratex.com>"); | |
200 | MODULE_LICENSE("GPL"); | |
201 | ||
5d26a105 KC |
202 | MODULE_ALIAS_CRYPTO("crc32"); |
203 | MODULE_ALIAS_CRYPTO("crc32-pclmul"); |