GNU Linux-libre 4.14.266-gnu1
[releases.git] / arch / x86 / crypto / crc32-pclmul_glue.c
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).
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16  * version 2 along with this program; If not, see http://www.gnu.org/licenses
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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/cpufeatures.h>
37 #include <asm/cpu_device_id.h>
38 #include <asm/fpu/api.h>
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_flags              = CRYPTO_ALG_OPTIONAL_KEY,
166                         .cra_blocksize          = CHKSUM_BLOCK_SIZE,
167                         .cra_ctxsize            = sizeof(u32),
168                         .cra_module             = THIS_MODULE,
169                         .cra_init               = crc32_pclmul_cra_init,
170         }
171 };
172
173 static const struct x86_cpu_id crc32pclmul_cpu_id[] = {
174         X86_FEATURE_MATCH(X86_FEATURE_PCLMULQDQ),
175         {}
176 };
177 MODULE_DEVICE_TABLE(x86cpu, crc32pclmul_cpu_id);
178
179
180 static int __init crc32_pclmul_mod_init(void)
181 {
182
183         if (!x86_match_cpu(crc32pclmul_cpu_id)) {
184                 pr_info("PCLMULQDQ-NI instructions are not detected.\n");
185                 return -ENODEV;
186         }
187         return crypto_register_shash(&alg);
188 }
189
190 static void __exit crc32_pclmul_mod_fini(void)
191 {
192         crypto_unregister_shash(&alg);
193 }
194
195 module_init(crc32_pclmul_mod_init);
196 module_exit(crc32_pclmul_mod_fini);
197
198 MODULE_AUTHOR("Alexander Boyko <alexander_boyko@xyratex.com>");
199 MODULE_LICENSE("GPL");
200
201 MODULE_ALIAS_CRYPTO("crc32");
202 MODULE_ALIAS_CRYPTO("crc32-pclmul");