1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * NHPoly1305 - ε-almost-∆-universal hash function for Adiantum
4  * (ARM64 NEON accelerated version)
5  *
6  * Copyright 2018 Google LLC
7  */
8 
9 #include <asm/neon.h>
10 #include <asm/simd.h>
11 #include <crypto/internal/hash.h>
12 #include <crypto/internal/simd.h>
13 #include <crypto/nhpoly1305.h>
14 #include <linux/module.h>
15 
16 asmlinkage void nh_neon(const u32 *key, const u8 *message, size_t message_len,
17 			u8 hash[NH_HASH_BYTES]);
18 
19 /* wrapper to avoid indirect call to assembly, which doesn't work with CFI */
20 static void _nh_neon(const u32 *key, const u8 *message, size_t message_len,
21 		     __le64 hash[NH_NUM_PASSES])
22 {
23 	nh_neon(key, message, message_len, (u8 *)hash);
24 }
25 
26 static int nhpoly1305_neon_update(struct shash_desc *desc,
27 				  const u8 *src, unsigned int srclen)
28 {
29 	if (srclen < 64 || !crypto_simd_usable())
30 		return crypto_nhpoly1305_update(desc, src, srclen);
31 
32 	do {
33 		unsigned int n = min_t(unsigned int, srclen, PAGE_SIZE);
34 
35 		kernel_neon_begin();
36 		crypto_nhpoly1305_update_helper(desc, src, n, _nh_neon);
37 		kernel_neon_end();
38 		src += n;
39 		srclen -= n;
40 	} while (srclen);
41 	return 0;
42 }
43 
44 static struct shash_alg nhpoly1305_alg = {
45 	.base.cra_name		= "nhpoly1305",
46 	.base.cra_driver_name	= "nhpoly1305-neon",
47 	.base.cra_priority	= 200,
48 	.base.cra_ctxsize	= sizeof(struct nhpoly1305_key),
49 	.base.cra_module	= THIS_MODULE,
50 	.digestsize		= POLY1305_DIGEST_SIZE,
51 	.init			= crypto_nhpoly1305_init,
52 	.update			= nhpoly1305_neon_update,
53 	.final			= crypto_nhpoly1305_final,
54 	.setkey			= crypto_nhpoly1305_setkey,
55 	.descsize		= sizeof(struct nhpoly1305_state),
56 };
57 
58 static int __init nhpoly1305_mod_init(void)
59 {
60 	if (!cpu_have_named_feature(ASIMD))
61 		return -ENODEV;
62 
63 	return crypto_register_shash(&nhpoly1305_alg);
64 }
65 
66 static void __exit nhpoly1305_mod_exit(void)
67 {
68 	crypto_unregister_shash(&nhpoly1305_alg);
69 }
70 
71 module_init(nhpoly1305_mod_init);
72 module_exit(nhpoly1305_mod_exit);
73 
74 MODULE_DESCRIPTION("NHPoly1305 ε-almost-∆-universal hash function (NEON-accelerated)");
75 MODULE_LICENSE("GPL v2");
76 MODULE_AUTHOR("Eric Biggers <ebiggers@google.com>");
77 MODULE_ALIAS_CRYPTO("nhpoly1305");
78 MODULE_ALIAS_CRYPTO("nhpoly1305-neon");
79