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 
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 
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 		kernel_neon_begin();
41 		*crc = crc_t10dif_pmull_p8(*crc, data, length);
42 		kernel_neon_end();
43 	} else {
44 		*crc = crc_t10dif_generic(*crc, data, length);
45 	}
46 
47 	return 0;
48 }
49 
50 static int crct10dif_update_pmull_p64(struct shash_desc *desc, const u8 *data,
51 			    unsigned int length)
52 {
53 	u16 *crc = shash_desc_ctx(desc);
54 
55 	if (length >= CRC_T10DIF_PMULL_CHUNK_SIZE && crypto_simd_usable()) {
56 		kernel_neon_begin();
57 		*crc = crc_t10dif_pmull_p64(*crc, data, length);
58 		kernel_neon_end();
59 	} else {
60 		*crc = crc_t10dif_generic(*crc, data, length);
61 	}
62 
63 	return 0;
64 }
65 
66 static int crct10dif_final(struct shash_desc *desc, u8 *out)
67 {
68 	u16 *crc = shash_desc_ctx(desc);
69 
70 	*(u16 *)out = *crc;
71 	return 0;
72 }
73 
74 static struct shash_alg crc_t10dif_alg[] = {{
75 	.digestsize		= CRC_T10DIF_DIGEST_SIZE,
76 	.init			= crct10dif_init,
77 	.update			= crct10dif_update_pmull_p8,
78 	.final			= crct10dif_final,
79 	.descsize		= CRC_T10DIF_DIGEST_SIZE,
80 
81 	.base.cra_name		= "crct10dif",
82 	.base.cra_driver_name	= "crct10dif-arm64-neon",
83 	.base.cra_priority	= 100,
84 	.base.cra_blocksize	= CRC_T10DIF_BLOCK_SIZE,
85 	.base.cra_module	= THIS_MODULE,
86 }, {
87 	.digestsize		= CRC_T10DIF_DIGEST_SIZE,
88 	.init			= crct10dif_init,
89 	.update			= crct10dif_update_pmull_p64,
90 	.final			= crct10dif_final,
91 	.descsize		= CRC_T10DIF_DIGEST_SIZE,
92 
93 	.base.cra_name		= "crct10dif",
94 	.base.cra_driver_name	= "crct10dif-arm64-ce",
95 	.base.cra_priority	= 200,
96 	.base.cra_blocksize	= CRC_T10DIF_BLOCK_SIZE,
97 	.base.cra_module	= THIS_MODULE,
98 }};
99 
100 static int __init crc_t10dif_mod_init(void)
101 {
102 	if (cpu_have_named_feature(PMULL))
103 		return crypto_register_shashes(crc_t10dif_alg,
104 					       ARRAY_SIZE(crc_t10dif_alg));
105 	else
106 		/* only register the first array element */
107 		return crypto_register_shash(crc_t10dif_alg);
108 }
109 
110 static void __exit crc_t10dif_mod_exit(void)
111 {
112 	if (cpu_have_named_feature(PMULL))
113 		crypto_unregister_shashes(crc_t10dif_alg,
114 					  ARRAY_SIZE(crc_t10dif_alg));
115 	else
116 		crypto_unregister_shash(crc_t10dif_alg);
117 }
118 
119 module_cpu_feature_match(ASIMD, crc_t10dif_mod_init);
120 module_exit(crc_t10dif_mod_exit);
121 
122 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
123 MODULE_LICENSE("GPL v2");
124 MODULE_ALIAS_CRYPTO("crct10dif");
125 MODULE_ALIAS_CRYPTO("crct10dif-arm64-ce");
126