1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Accelerated CRC-T10DIF using arm64 NEON and Crypto Extensions instructions
4 *
5 * Copyright (C) 2016 - 2017 Linaro Ltd <ard.biesheuvel@linaro.org>
6 */
7
8 #include <linux/cpufeature.h>
9 #include <linux/crc-t10dif.h>
10 #include <linux/init.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/string.h>
14
15 #include <crypto/internal/hash.h>
16 #include <crypto/internal/simd.h>
17
18 #include <asm/neon.h>
19 #include <asm/simd.h>
20
21 #define CRC_T10DIF_PMULL_CHUNK_SIZE 16U
22
23 asmlinkage u16 crc_t10dif_pmull_p8(u16 init_crc, const u8 *buf, size_t len);
24 asmlinkage u16 crc_t10dif_pmull_p64(u16 init_crc, const u8 *buf, size_t len);
25
crct10dif_init(struct shash_desc * desc)26 static int crct10dif_init(struct shash_desc *desc)
27 {
28 u16 *crc = shash_desc_ctx(desc);
29
30 *crc = 0;
31 return 0;
32 }
33
crct10dif_update_pmull_p8(struct shash_desc * desc,const u8 * data,unsigned int length)34 static int crct10dif_update_pmull_p8(struct shash_desc *desc, const u8 *data,
35 unsigned int length)
36 {
37 u16 *crc = shash_desc_ctx(desc);
38
39 if (length >= CRC_T10DIF_PMULL_CHUNK_SIZE && crypto_simd_usable()) {
40 do {
41 unsigned int chunk = length;
42
43 if (chunk > SZ_4K + CRC_T10DIF_PMULL_CHUNK_SIZE)
44 chunk = SZ_4K;
45
46 kernel_neon_begin();
47 *crc = crc_t10dif_pmull_p8(*crc, data, chunk);
48 kernel_neon_end();
49 data += chunk;
50 length -= chunk;
51 } while (length);
52 } else {
53 *crc = crc_t10dif_generic(*crc, data, length);
54 }
55
56 return 0;
57 }
58
crct10dif_update_pmull_p64(struct shash_desc * desc,const u8 * data,unsigned int length)59 static int crct10dif_update_pmull_p64(struct shash_desc *desc, const u8 *data,
60 unsigned int length)
61 {
62 u16 *crc = shash_desc_ctx(desc);
63
64 if (length >= CRC_T10DIF_PMULL_CHUNK_SIZE && crypto_simd_usable()) {
65 do {
66 unsigned int chunk = length;
67
68 if (chunk > SZ_4K + CRC_T10DIF_PMULL_CHUNK_SIZE)
69 chunk = SZ_4K;
70
71 kernel_neon_begin();
72 *crc = crc_t10dif_pmull_p64(*crc, data, chunk);
73 kernel_neon_end();
74 data += chunk;
75 length -= chunk;
76 } while (length);
77 } else {
78 *crc = crc_t10dif_generic(*crc, data, length);
79 }
80
81 return 0;
82 }
83
crct10dif_final(struct shash_desc * desc,u8 * out)84 static int crct10dif_final(struct shash_desc *desc, u8 *out)
85 {
86 u16 *crc = shash_desc_ctx(desc);
87
88 *(u16 *)out = *crc;
89 return 0;
90 }
91
92 static struct shash_alg crc_t10dif_alg[] = {{
93 .digestsize = CRC_T10DIF_DIGEST_SIZE,
94 .init = crct10dif_init,
95 .update = crct10dif_update_pmull_p8,
96 .final = crct10dif_final,
97 .descsize = CRC_T10DIF_DIGEST_SIZE,
98
99 .base.cra_name = "crct10dif",
100 .base.cra_driver_name = "crct10dif-arm64-neon",
101 .base.cra_priority = 100,
102 .base.cra_blocksize = CRC_T10DIF_BLOCK_SIZE,
103 .base.cra_module = THIS_MODULE,
104 }, {
105 .digestsize = CRC_T10DIF_DIGEST_SIZE,
106 .init = crct10dif_init,
107 .update = crct10dif_update_pmull_p64,
108 .final = crct10dif_final,
109 .descsize = CRC_T10DIF_DIGEST_SIZE,
110
111 .base.cra_name = "crct10dif",
112 .base.cra_driver_name = "crct10dif-arm64-ce",
113 .base.cra_priority = 200,
114 .base.cra_blocksize = CRC_T10DIF_BLOCK_SIZE,
115 .base.cra_module = THIS_MODULE,
116 }};
117
crc_t10dif_mod_init(void)118 static int __init crc_t10dif_mod_init(void)
119 {
120 if (cpu_have_named_feature(PMULL))
121 return crypto_register_shashes(crc_t10dif_alg,
122 ARRAY_SIZE(crc_t10dif_alg));
123 else
124 /* only register the first array element */
125 return crypto_register_shash(crc_t10dif_alg);
126 }
127
crc_t10dif_mod_exit(void)128 static void __exit crc_t10dif_mod_exit(void)
129 {
130 if (cpu_have_named_feature(PMULL))
131 crypto_unregister_shashes(crc_t10dif_alg,
132 ARRAY_SIZE(crc_t10dif_alg));
133 else
134 crypto_unregister_shash(crc_t10dif_alg);
135 }
136
137 module_cpu_feature_match(ASIMD, crc_t10dif_mod_init);
138 module_exit(crc_t10dif_mod_exit);
139
140 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
141 MODULE_LICENSE("GPL v2");
142 MODULE_ALIAS_CRYPTO("crct10dif");
143 MODULE_ALIAS_CRYPTO("crct10dif-arm64-ce");
144
