1/*
2 * Cryptographic API.
3 *
4 * Glue code for the SHA256 Secure Hash Algorithm assembler
5 * implementation using supplemental SSE3 / AVX / AVX2 instructions.
6 *
7 * This file is based on sha256_generic.c
8 *
9 * Copyright (C) 2013 Intel Corporation.
10 *
11 * Author:
12 *     Tim Chen <tim.c.chen@linux.intel.com>
13 *
14 * This program is free software; you can redistribute it and/or modify it
15 * under the terms of the GNU General Public License as published by the Free
16 * Software Foundation; either version 2 of the License, or (at your option)
17 * any later version.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
20 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
21 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
22 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
23 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
24 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
25 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
26 * SOFTWARE.
27 */
28
29
30#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
31
32#include <crypto/internal/hash.h>
33#include <linux/init.h>
34#include <linux/module.h>
35#include <linux/mm.h>
36#include <linux/cryptohash.h>
37#include <linux/types.h>
38#include <crypto/sha.h>
39#include <crypto/sha256_base.h>
40#include <asm/i387.h>
41#include <asm/xcr.h>
42#include <asm/xsave.h>
43#include <linux/string.h>
44
45asmlinkage void sha256_transform_ssse3(u32 *digest, const char *data,
46				       u64 rounds);
47#ifdef CONFIG_AS_AVX
48asmlinkage void sha256_transform_avx(u32 *digest, const char *data,
49				     u64 rounds);
50#endif
51#ifdef CONFIG_AS_AVX2
52asmlinkage void sha256_transform_rorx(u32 *digest, const char *data,
53				      u64 rounds);
54#endif
55
56static void (*sha256_transform_asm)(u32 *, const char *, u64);
57
58static int sha256_ssse3_update(struct shash_desc *desc, const u8 *data,
59			     unsigned int len)
60{
61	struct sha256_state *sctx = shash_desc_ctx(desc);
62
63	if (!irq_fpu_usable() ||
64	    (sctx->count % SHA256_BLOCK_SIZE) + len < SHA256_BLOCK_SIZE)
65		return crypto_sha256_update(desc, data, len);
66
67	/* make sure casting to sha256_block_fn() is safe */
68	BUILD_BUG_ON(offsetof(struct sha256_state, state) != 0);
69
70	kernel_fpu_begin();
71	sha256_base_do_update(desc, data, len,
72			      (sha256_block_fn *)sha256_transform_asm);
73	kernel_fpu_end();
74
75	return 0;
76}
77
78static int sha256_ssse3_finup(struct shash_desc *desc, const u8 *data,
79			      unsigned int len, u8 *out)
80{
81	if (!irq_fpu_usable())
82		return crypto_sha256_finup(desc, data, len, out);
83
84	kernel_fpu_begin();
85	if (len)
86		sha256_base_do_update(desc, data, len,
87				      (sha256_block_fn *)sha256_transform_asm);
88	sha256_base_do_finalize(desc, (sha256_block_fn *)sha256_transform_asm);
89	kernel_fpu_end();
90
91	return sha256_base_finish(desc, out);
92}
93
94/* Add padding and return the message digest. */
95static int sha256_ssse3_final(struct shash_desc *desc, u8 *out)
96{
97	return sha256_ssse3_finup(desc, NULL, 0, out);
98}
99
100static struct shash_alg algs[] = { {
101	.digestsize	=	SHA256_DIGEST_SIZE,
102	.init		=	sha256_base_init,
103	.update		=	sha256_ssse3_update,
104	.final		=	sha256_ssse3_final,
105	.finup		=	sha256_ssse3_finup,
106	.descsize	=	sizeof(struct sha256_state),
107	.base		=	{
108		.cra_name	=	"sha256",
109		.cra_driver_name =	"sha256-ssse3",
110		.cra_priority	=	150,
111		.cra_flags	=	CRYPTO_ALG_TYPE_SHASH,
112		.cra_blocksize	=	SHA256_BLOCK_SIZE,
113		.cra_module	=	THIS_MODULE,
114	}
115}, {
116	.digestsize	=	SHA224_DIGEST_SIZE,
117	.init		=	sha224_base_init,
118	.update		=	sha256_ssse3_update,
119	.final		=	sha256_ssse3_final,
120	.finup		=	sha256_ssse3_finup,
121	.descsize	=	sizeof(struct sha256_state),
122	.base		=	{
123		.cra_name	=	"sha224",
124		.cra_driver_name =	"sha224-ssse3",
125		.cra_priority	=	150,
126		.cra_flags	=	CRYPTO_ALG_TYPE_SHASH,
127		.cra_blocksize	=	SHA224_BLOCK_SIZE,
128		.cra_module	=	THIS_MODULE,
129	}
130} };
131
132#ifdef CONFIG_AS_AVX
133static bool __init avx_usable(void)
134{
135	u64 xcr0;
136
137	if (!cpu_has_avx || !cpu_has_osxsave)
138		return false;
139
140	xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
141	if ((xcr0 & (XSTATE_SSE | XSTATE_YMM)) != (XSTATE_SSE | XSTATE_YMM)) {
142		pr_info("AVX detected but unusable.\n");
143
144		return false;
145	}
146
147	return true;
148}
149#endif
150
151static int __init sha256_ssse3_mod_init(void)
152{
153	/* test for SSSE3 first */
154	if (cpu_has_ssse3)
155		sha256_transform_asm = sha256_transform_ssse3;
156
157#ifdef CONFIG_AS_AVX
158	/* allow AVX to override SSSE3, it's a little faster */
159	if (avx_usable()) {
160#ifdef CONFIG_AS_AVX2
161		if (boot_cpu_has(X86_FEATURE_AVX2) && boot_cpu_has(X86_FEATURE_BMI2))
162			sha256_transform_asm = sha256_transform_rorx;
163		else
164#endif
165			sha256_transform_asm = sha256_transform_avx;
166	}
167#endif
168
169	if (sha256_transform_asm) {
170#ifdef CONFIG_AS_AVX
171		if (sha256_transform_asm == sha256_transform_avx)
172			pr_info("Using AVX optimized SHA-256 implementation\n");
173#ifdef CONFIG_AS_AVX2
174		else if (sha256_transform_asm == sha256_transform_rorx)
175			pr_info("Using AVX2 optimized SHA-256 implementation\n");
176#endif
177		else
178#endif
179			pr_info("Using SSSE3 optimized SHA-256 implementation\n");
180		return crypto_register_shashes(algs, ARRAY_SIZE(algs));
181	}
182	pr_info("Neither AVX nor SSSE3 is available/usable.\n");
183
184	return -ENODEV;
185}
186
187static void __exit sha256_ssse3_mod_fini(void)
188{
189	crypto_unregister_shashes(algs, ARRAY_SIZE(algs));
190}
191
192module_init(sha256_ssse3_mod_init);
193module_exit(sha256_ssse3_mod_fini);
194
195MODULE_LICENSE("GPL");
196MODULE_DESCRIPTION("SHA256 Secure Hash Algorithm, Supplemental SSE3 accelerated");
197
198MODULE_ALIAS_CRYPTO("sha256");
199MODULE_ALIAS_CRYPTO("sha224");
200