xref: /openbmc/linux/arch/arm64/crypto/sha2-ce-glue.c (revision 981ab3f1)
1 /*
2  * sha2-ce-glue.c - SHA-224/SHA-256 using ARMv8 Crypto Extensions
3  *
4  * Copyright (C) 2014 Linaro Ltd <ard.biesheuvel@linaro.org>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 
11 #include <asm/neon.h>
12 #include <asm/unaligned.h>
13 #include <crypto/internal/hash.h>
14 #include <crypto/sha.h>
15 #include <crypto/sha256_base.h>
16 #include <linux/cpufeature.h>
17 #include <linux/crypto.h>
18 #include <linux/module.h>
19 
20 MODULE_DESCRIPTION("SHA-224/SHA-256 secure hash using ARMv8 Crypto Extensions");
21 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
22 MODULE_LICENSE("GPL v2");
23 
24 struct sha256_ce_state {
25 	struct sha256_state	sst;
26 	u32			finalize;
27 };
28 
29 asmlinkage void sha2_ce_transform(struct sha256_ce_state *sst, u8 const *src,
30 				  int blocks);
31 
32 const u32 sha256_ce_offsetof_count = offsetof(struct sha256_ce_state,
33 					      sst.count);
34 const u32 sha256_ce_offsetof_finalize = offsetof(struct sha256_ce_state,
35 						 finalize);
36 
37 static int sha256_ce_update(struct shash_desc *desc, const u8 *data,
38 			    unsigned int len)
39 {
40 	struct sha256_ce_state *sctx = shash_desc_ctx(desc);
41 
42 	sctx->finalize = 0;
43 	kernel_neon_begin_partial(28);
44 	sha256_base_do_update(desc, data, len,
45 			      (sha256_block_fn *)sha2_ce_transform);
46 	kernel_neon_end();
47 
48 	return 0;
49 }
50 
51 static int sha256_ce_finup(struct shash_desc *desc, const u8 *data,
52 			   unsigned int len, u8 *out)
53 {
54 	struct sha256_ce_state *sctx = shash_desc_ctx(desc);
55 	bool finalize = !sctx->sst.count && !(len % SHA256_BLOCK_SIZE);
56 
57 	/*
58 	 * Allow the asm code to perform the finalization if there is no
59 	 * partial data and the input is a round multiple of the block size.
60 	 */
61 	sctx->finalize = finalize;
62 
63 	kernel_neon_begin_partial(28);
64 	sha256_base_do_update(desc, data, len,
65 			      (sha256_block_fn *)sha2_ce_transform);
66 	if (!finalize)
67 		sha256_base_do_finalize(desc,
68 					(sha256_block_fn *)sha2_ce_transform);
69 	kernel_neon_end();
70 	return sha256_base_finish(desc, out);
71 }
72 
73 static int sha256_ce_final(struct shash_desc *desc, u8 *out)
74 {
75 	struct sha256_ce_state *sctx = shash_desc_ctx(desc);
76 
77 	sctx->finalize = 0;
78 	kernel_neon_begin_partial(28);
79 	sha256_base_do_finalize(desc, (sha256_block_fn *)sha2_ce_transform);
80 	kernel_neon_end();
81 	return sha256_base_finish(desc, out);
82 }
83 
84 static struct shash_alg algs[] = { {
85 	.init			= sha224_base_init,
86 	.update			= sha256_ce_update,
87 	.final			= sha256_ce_final,
88 	.finup			= sha256_ce_finup,
89 	.descsize		= sizeof(struct sha256_ce_state),
90 	.digestsize		= SHA224_DIGEST_SIZE,
91 	.base			= {
92 		.cra_name		= "sha224",
93 		.cra_driver_name	= "sha224-ce",
94 		.cra_priority		= 200,
95 		.cra_flags		= CRYPTO_ALG_TYPE_SHASH,
96 		.cra_blocksize		= SHA256_BLOCK_SIZE,
97 		.cra_module		= THIS_MODULE,
98 	}
99 }, {
100 	.init			= sha256_base_init,
101 	.update			= sha256_ce_update,
102 	.final			= sha256_ce_final,
103 	.finup			= sha256_ce_finup,
104 	.descsize		= sizeof(struct sha256_ce_state),
105 	.digestsize		= SHA256_DIGEST_SIZE,
106 	.base			= {
107 		.cra_name		= "sha256",
108 		.cra_driver_name	= "sha256-ce",
109 		.cra_priority		= 200,
110 		.cra_flags		= CRYPTO_ALG_TYPE_SHASH,
111 		.cra_blocksize		= SHA256_BLOCK_SIZE,
112 		.cra_module		= THIS_MODULE,
113 	}
114 } };
115 
116 static int __init sha2_ce_mod_init(void)
117 {
118 	return crypto_register_shashes(algs, ARRAY_SIZE(algs));
119 }
120 
121 static void __exit sha2_ce_mod_fini(void)
122 {
123 	crypto_unregister_shashes(algs, ARRAY_SIZE(algs));
124 }
125 
126 module_cpu_feature_match(SHA2, sha2_ce_mod_init);
127 module_exit(sha2_ce_mod_fini);
128