1/*
2 * sha1-ce-glue.c - SHA-1 secure hash 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/sha1_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("SHA1 secure hash using ARMv8 Crypto Extensions");
24MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
25MODULE_LICENSE("GPL v2");
26
27struct sha1_ce_state {
28	struct sha1_state	sst;
29	u32			finalize;
30};
31
32asmlinkage void sha1_ce_transform(struct sha1_ce_state *sst, u8 const *src,
33				  int blocks);
34
35static int sha1_ce_update(struct shash_desc *desc, const u8 *data,
36			  unsigned int len)
37{
38	struct sha1_ce_state *sctx = shash_desc_ctx(desc);
39
40	sctx->finalize = 0;
41	kernel_neon_begin_partial(16);
42	sha1_base_do_update(desc, data, len,
43			    (sha1_block_fn *)sha1_ce_transform);
44	kernel_neon_end();
45
46	return 0;
47}
48
49static int sha1_ce_finup(struct shash_desc *desc, const u8 *data,
50			 unsigned int len, u8 *out)
51{
52	struct sha1_ce_state *sctx = shash_desc_ctx(desc);
53	bool finalize = !sctx->sst.count && !(len % SHA1_BLOCK_SIZE);
54
55	ASM_EXPORT(sha1_ce_offsetof_count,
56		   offsetof(struct sha1_ce_state, sst.count));
57	ASM_EXPORT(sha1_ce_offsetof_finalize,
58		   offsetof(struct sha1_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(16);
67	sha1_base_do_update(desc, data, len,
68			    (sha1_block_fn *)sha1_ce_transform);
69	if (!finalize)
70		sha1_base_do_finalize(desc, (sha1_block_fn *)sha1_ce_transform);
71	kernel_neon_end();
72	return sha1_base_finish(desc, out);
73}
74
75static int sha1_ce_final(struct shash_desc *desc, u8 *out)
76{
77	struct sha1_ce_state *sctx = shash_desc_ctx(desc);
78
79	sctx->finalize = 0;
80	kernel_neon_begin_partial(16);
81	sha1_base_do_finalize(desc, (sha1_block_fn *)sha1_ce_transform);
82	kernel_neon_end();
83	return sha1_base_finish(desc, out);
84}
85
86static struct shash_alg alg = {
87	.init			= sha1_base_init,
88	.update			= sha1_ce_update,
89	.final			= sha1_ce_final,
90	.finup			= sha1_ce_finup,
91	.descsize		= sizeof(struct sha1_ce_state),
92	.digestsize		= SHA1_DIGEST_SIZE,
93	.base			= {
94		.cra_name		= "sha1",
95		.cra_driver_name	= "sha1-ce",
96		.cra_priority		= 200,
97		.cra_flags		= CRYPTO_ALG_TYPE_SHASH,
98		.cra_blocksize		= SHA1_BLOCK_SIZE,
99		.cra_module		= THIS_MODULE,
100	}
101};
102
103static int __init sha1_ce_mod_init(void)
104{
105	return crypto_register_shash(&alg);
106}
107
108static void __exit sha1_ce_mod_fini(void)
109{
110	crypto_unregister_shash(&alg);
111}
112
113module_cpu_feature_match(SHA1, sha1_ce_mod_init);
114module_exit(sha1_ce_mod_fini);
115