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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> | |
35 | ||
36 | #include <asm/cpufeature.h> | |
37 | #include <asm/cpu_device_id.h> | |
df6b35f4 | 38 | #include <asm/fpu/api.h> |
78c37d19 AB |
39 | |
40 | #define CHKSUM_BLOCK_SIZE 1 | |
41 | #define CHKSUM_DIGEST_SIZE 4 | |
42 | ||
43 | #define PCLMUL_MIN_LEN 64L /* minimum size of buffer | |
44 | * for crc32_pclmul_le_16 */ | |
45 | #define SCALE_F 16L /* size of xmm register */ | |
46 | #define SCALE_F_MASK (SCALE_F - 1) | |
47 | ||
48 | u32 crc32_pclmul_le_16(unsigned char const *buffer, size_t len, u32 crc32); | |
49 | ||
50 | static u32 __attribute__((pure)) | |
51 | crc32_pclmul_le(u32 crc, unsigned char const *p, size_t len) | |
52 | { | |
53 | unsigned int iquotient; | |
54 | unsigned int iremainder; | |
55 | unsigned int prealign; | |
56 | ||
57 | if (len < PCLMUL_MIN_LEN + SCALE_F_MASK || !irq_fpu_usable()) | |
58 | return crc32_le(crc, p, len); | |
59 | ||
60 | if ((long)p & SCALE_F_MASK) { | |
61 | /* align p to 16 byte */ | |
62 | prealign = SCALE_F - ((long)p & SCALE_F_MASK); | |
63 | ||
64 | crc = crc32_le(crc, p, prealign); | |
65 | len -= prealign; | |
66 | p = (unsigned char *)(((unsigned long)p + SCALE_F_MASK) & | |
67 | ~SCALE_F_MASK); | |
68 | } | |
69 | iquotient = len & (~SCALE_F_MASK); | |
70 | iremainder = len & SCALE_F_MASK; | |
71 | ||
72 | kernel_fpu_begin(); | |
73 | crc = crc32_pclmul_le_16(p, iquotient, crc); | |
74 | kernel_fpu_end(); | |
75 | ||
76 | if (iremainder) | |
77 | crc = crc32_le(crc, p + iquotient, iremainder); | |
78 | ||
79 | return crc; | |
80 | } | |
81 | ||
82 | static int crc32_pclmul_cra_init(struct crypto_tfm *tfm) | |
83 | { | |
84 | u32 *key = crypto_tfm_ctx(tfm); | |
85 | ||
86 | *key = 0; | |
87 | ||
88 | return 0; | |
89 | } | |
90 | ||
91 | static int crc32_pclmul_setkey(struct crypto_shash *hash, const u8 *key, | |
92 | unsigned int keylen) | |
93 | { | |
94 | u32 *mctx = crypto_shash_ctx(hash); | |
95 | ||
96 | if (keylen != sizeof(u32)) { | |
97 | crypto_shash_set_flags(hash, CRYPTO_TFM_RES_BAD_KEY_LEN); | |
98 | return -EINVAL; | |
99 | } | |
100 | *mctx = le32_to_cpup((__le32 *)key); | |
101 | return 0; | |
102 | } | |
103 | ||
104 | static int crc32_pclmul_init(struct shash_desc *desc) | |
105 | { | |
106 | u32 *mctx = crypto_shash_ctx(desc->tfm); | |
107 | u32 *crcp = shash_desc_ctx(desc); | |
108 | ||
109 | *crcp = *mctx; | |
110 | ||
111 | return 0; | |
112 | } | |
113 | ||
114 | static int crc32_pclmul_update(struct shash_desc *desc, const u8 *data, | |
115 | unsigned int len) | |
116 | { | |
117 | u32 *crcp = shash_desc_ctx(desc); | |
118 | ||
119 | *crcp = crc32_pclmul_le(*crcp, data, len); | |
120 | return 0; | |
121 | } | |
122 | ||
123 | /* No final XOR 0xFFFFFFFF, like crc32_le */ | |
124 | static int __crc32_pclmul_finup(u32 *crcp, const u8 *data, unsigned int len, | |
125 | u8 *out) | |
126 | { | |
127 | *(__le32 *)out = cpu_to_le32(crc32_pclmul_le(*crcp, data, len)); | |
128 | return 0; | |
129 | } | |
130 | ||
131 | static int crc32_pclmul_finup(struct shash_desc *desc, const u8 *data, | |
132 | unsigned int len, u8 *out) | |
133 | { | |
134 | return __crc32_pclmul_finup(shash_desc_ctx(desc), data, len, out); | |
135 | } | |
136 | ||
137 | static int crc32_pclmul_final(struct shash_desc *desc, u8 *out) | |
138 | { | |
139 | u32 *crcp = shash_desc_ctx(desc); | |
140 | ||
141 | *(__le32 *)out = cpu_to_le32p(crcp); | |
142 | return 0; | |
143 | } | |
144 | ||
145 | static int crc32_pclmul_digest(struct shash_desc *desc, const u8 *data, | |
146 | unsigned int len, u8 *out) | |
147 | { | |
148 | return __crc32_pclmul_finup(crypto_shash_ctx(desc->tfm), data, len, | |
149 | out); | |
150 | } | |
151 | ||
152 | static struct shash_alg alg = { | |
153 | .setkey = crc32_pclmul_setkey, | |
154 | .init = crc32_pclmul_init, | |
155 | .update = crc32_pclmul_update, | |
156 | .final = crc32_pclmul_final, | |
157 | .finup = crc32_pclmul_finup, | |
158 | .digest = crc32_pclmul_digest, | |
159 | .descsize = sizeof(u32), | |
160 | .digestsize = CHKSUM_DIGEST_SIZE, | |
161 | .base = { | |
162 | .cra_name = "crc32", | |
163 | .cra_driver_name = "crc32-pclmul", | |
164 | .cra_priority = 200, | |
165 | .cra_blocksize = CHKSUM_BLOCK_SIZE, | |
166 | .cra_ctxsize = sizeof(u32), | |
167 | .cra_module = THIS_MODULE, | |
168 | .cra_init = crc32_pclmul_cra_init, | |
169 | } | |
170 | }; | |
171 | ||
172 | static const struct x86_cpu_id crc32pclmul_cpu_id[] = { | |
173 | X86_FEATURE_MATCH(X86_FEATURE_PCLMULQDQ), | |
174 | {} | |
175 | }; | |
176 | MODULE_DEVICE_TABLE(x86cpu, crc32pclmul_cpu_id); | |
177 | ||
178 | ||
179 | static int __init crc32_pclmul_mod_init(void) | |
180 | { | |
181 | ||
182 | if (!x86_match_cpu(crc32pclmul_cpu_id)) { | |
183 | pr_info("PCLMULQDQ-NI instructions are not detected.\n"); | |
184 | return -ENODEV; | |
185 | } | |
186 | return crypto_register_shash(&alg); | |
187 | } | |
188 | ||
189 | static void __exit crc32_pclmul_mod_fini(void) | |
190 | { | |
191 | crypto_unregister_shash(&alg); | |
192 | } | |
193 | ||
194 | module_init(crc32_pclmul_mod_init); | |
195 | module_exit(crc32_pclmul_mod_fini); | |
196 | ||
197 | MODULE_AUTHOR("Alexander Boyko <alexander_boyko@xyratex.com>"); | |
198 | MODULE_LICENSE("GPL"); | |
199 | ||
5d26a105 KC |
200 | MODULE_ALIAS_CRYPTO("crc32"); |
201 | MODULE_ALIAS_CRYPTO("crc32-pclmul"); |