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