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
23MODULE_DESCRIPTION("SHA-224/SHA-256 secure hash using ARMv8 Crypto Extensions");
24MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
25MODULE_LICENSE("GPL v2");
26
27struct sha256_ce_state {
28	struct sha256_state	sst;
29	u32			finalize;
30};
31
32asmlinkage void sha2_ce_transform(struct sha256_ce_state *sst, u8 const *src,
33				  int blocks);
34
35static 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
49static 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
76static 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
87static 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
119static int __init sha2_ce_mod_init(void)
120{
121	return crypto_register_shashes(algs, ARRAY_SIZE(algs));
122}
123
124static void __exit sha2_ce_mod_fini(void)
125{
126	crypto_unregister_shashes(algs, ARRAY_SIZE(algs));
127}
128
129module_cpu_feature_match(SHA2, sha2_ce_mod_init);
130module_exit(sha2_ce_mod_fini);
131