1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * NHPoly1305 - ε-almost-∆-universal hash function for Adiantum
4  * (AVX2 accelerated version)
5  *
6  * Copyright 2018 Google LLC
7  */
8 
9 #include <crypto/internal/hash.h>
10 #include <crypto/nhpoly1305.h>
11 #include <linux/module.h>
12 #include <asm/fpu/api.h>
13 
14 asmlinkage void nh_avx2(const u32 *key, const u8 *message, size_t message_len,
15 			u8 hash[NH_HASH_BYTES]);
16 
17 /* wrapper to avoid indirect call to assembly, which doesn't work with CFI */
18 static void _nh_avx2(const u32 *key, const u8 *message, size_t message_len,
19 		     __le64 hash[NH_NUM_PASSES])
20 {
21 	nh_avx2(key, message, message_len, (u8 *)hash);
22 }
23 
24 static int nhpoly1305_avx2_update(struct shash_desc *desc,
25 				  const u8 *src, unsigned int srclen)
26 {
27 	if (srclen < 64 || !irq_fpu_usable())
28 		return crypto_nhpoly1305_update(desc, src, srclen);
29 
30 	do {
31 		unsigned int n = min_t(unsigned int, srclen, PAGE_SIZE);
32 
33 		kernel_fpu_begin();
34 		crypto_nhpoly1305_update_helper(desc, src, n, _nh_avx2);
35 		kernel_fpu_end();
36 		src += n;
37 		srclen -= n;
38 	} while (srclen);
39 	return 0;
40 }
41 
42 static struct shash_alg nhpoly1305_alg = {
43 	.base.cra_name		= "nhpoly1305",
44 	.base.cra_driver_name	= "nhpoly1305-avx2",
45 	.base.cra_priority	= 300,
46 	.base.cra_ctxsize	= sizeof(struct nhpoly1305_key),
47 	.base.cra_module	= THIS_MODULE,
48 	.digestsize		= POLY1305_DIGEST_SIZE,
49 	.init			= crypto_nhpoly1305_init,
50 	.update			= nhpoly1305_avx2_update,
51 	.final			= crypto_nhpoly1305_final,
52 	.setkey			= crypto_nhpoly1305_setkey,
53 	.descsize		= sizeof(struct nhpoly1305_state),
54 };
55 
56 static int __init nhpoly1305_mod_init(void)
57 {
58 	if (!boot_cpu_has(X86_FEATURE_AVX2) ||
59 	    !boot_cpu_has(X86_FEATURE_OSXSAVE))
60 		return -ENODEV;
61 
62 	return crypto_register_shash(&nhpoly1305_alg);
63 }
64 
65 static void __exit nhpoly1305_mod_exit(void)
66 {
67 	crypto_unregister_shash(&nhpoly1305_alg);
68 }
69 
70 module_init(nhpoly1305_mod_init);
71 module_exit(nhpoly1305_mod_exit);
72 
73 MODULE_DESCRIPTION("NHPoly1305 ε-almost-∆-universal hash function (AVX2-accelerated)");
74 MODULE_LICENSE("GPL v2");
75 MODULE_AUTHOR("Eric Biggers <ebiggers@google.com>");
76 MODULE_ALIAS_CRYPTO("nhpoly1305");
77 MODULE_ALIAS_CRYPTO("nhpoly1305-avx2");
78