xref: /openbmc/linux/arch/arm64/crypto/sha2-ce-glue.c (revision bc5aa3a0)
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 #define ASM_EXPORT(sym, val) \
21 	asm(".globl " #sym "; .set " #sym ", %0" :: "I"(val));
22 
23 MODULE_DESCRIPTION("SHA-224/SHA-256 secure hash using ARMv8 Crypto Extensions");
24 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
25 MODULE_LICENSE("GPL v2");
26 
27 struct sha256_ce_state {
28 	struct sha256_state	sst;
29 	u32			finalize;
30 };
31 
32 asmlinkage void sha2_ce_transform(struct sha256_ce_state *sst, u8 const *src,
33 				  int blocks);
34 
35 static int sha256_ce_update(struct shash_desc *desc, const u8 *data,
36 			    unsigned int len)
37 {
38 	struct sha256_ce_state *sctx = shash_desc_ctx(desc);
39 
40 	sctx->finalize = 0;
41 	kernel_neon_begin_partial(28);
42 	sha256_base_do_update(desc, data, len,
43 			      (sha256_block_fn *)sha2_ce_transform);
44 	kernel_neon_end();
45 
46 	return 0;
47 }
48 
49 static int sha256_ce_finup(struct shash_desc *desc, const u8 *data,
50 			   unsigned int len, u8 *out)
51 {
52 	struct sha256_ce_state *sctx = shash_desc_ctx(desc);
53 	bool finalize = !sctx->sst.count && !(len % SHA256_BLOCK_SIZE);
54 
55 	ASM_EXPORT(sha256_ce_offsetof_count,
56 		   offsetof(struct sha256_ce_state, sst.count));
57 	ASM_EXPORT(sha256_ce_offsetof_finalize,
58 		   offsetof(struct sha256_ce_state, finalize));
59 
60 	/*
61 	 * Allow the asm code to perform the finalization if there is no
62 	 * partial data and the input is a round multiple of the block size.
63 	 */
64 	sctx->finalize = finalize;
65 
66 	kernel_neon_begin_partial(28);
67 	sha256_base_do_update(desc, data, len,
68 			      (sha256_block_fn *)sha2_ce_transform);
69 	if (!finalize)
70 		sha256_base_do_finalize(desc,
71 					(sha256_block_fn *)sha2_ce_transform);
72 	kernel_neon_end();
73 	return sha256_base_finish(desc, out);
74 }
75 
76 static int sha256_ce_final(struct shash_desc *desc, u8 *out)
77 {
78 	struct sha256_ce_state *sctx = shash_desc_ctx(desc);
79 
80 	sctx->finalize = 0;
81 	kernel_neon_begin_partial(28);
82 	sha256_base_do_finalize(desc, (sha256_block_fn *)sha2_ce_transform);
83 	kernel_neon_end();
84 	return sha256_base_finish(desc, out);
85 }
86 
87 static struct shash_alg algs[] = { {
88 	.init			= sha224_base_init,
89 	.update			= sha256_ce_update,
90 	.final			= sha256_ce_final,
91 	.finup			= sha256_ce_finup,
92 	.descsize		= sizeof(struct sha256_ce_state),
93 	.digestsize		= SHA224_DIGEST_SIZE,
94 	.base			= {
95 		.cra_name		= "sha224",
96 		.cra_driver_name	= "sha224-ce",
97 		.cra_priority		= 200,
98 		.cra_flags		= CRYPTO_ALG_TYPE_SHASH,
99 		.cra_blocksize		= SHA256_BLOCK_SIZE,
100 		.cra_module		= THIS_MODULE,
101 	}
102 }, {
103 	.init			= sha256_base_init,
104 	.update			= sha256_ce_update,
105 	.final			= sha256_ce_final,
106 	.finup			= sha256_ce_finup,
107 	.descsize		= sizeof(struct sha256_ce_state),
108 	.digestsize		= SHA256_DIGEST_SIZE,
109 	.base			= {
110 		.cra_name		= "sha256",
111 		.cra_driver_name	= "sha256-ce",
112 		.cra_priority		= 200,
113 		.cra_flags		= CRYPTO_ALG_TYPE_SHASH,
114 		.cra_blocksize		= SHA256_BLOCK_SIZE,
115 		.cra_module		= THIS_MODULE,
116 	}
117 } };
118 
119 static int __init sha2_ce_mod_init(void)
120 {
121 	return crypto_register_shashes(algs, ARRAY_SIZE(algs));
122 }
123 
124 static void __exit sha2_ce_mod_fini(void)
125 {
126 	crypto_unregister_shashes(algs, ARRAY_SIZE(algs));
127 }
128 
129 module_cpu_feature_match(SHA2, sha2_ce_mod_init);
130 module_exit(sha2_ce_mod_fini);
131