1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Accelerated CRC-T10DIF using arm64 NEON and Crypto Extensions instructions
4 *
5 * Copyright (C) 2016 - 2017 Linaro Ltd <ard.biesheuvel@linaro.org>
6 */
7
8#include <linux/cpufeature.h>
9#include <linux/crc-t10dif.h>
10#include <linux/init.h>
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/string.h>
14
15#include <crypto/internal/hash.h>
16#include <crypto/internal/simd.h>
17
18#include <asm/neon.h>
19#include <asm/simd.h>
20
21#define CRC_T10DIF_PMULL_CHUNK_SIZE	16U
22
23asmlinkage u16 crc_t10dif_pmull_p8(u16 init_crc, const u8 *buf, size_t len);
24asmlinkage u16 crc_t10dif_pmull_p64(u16 init_crc, const u8 *buf, size_t len);
25
26static int crct10dif_init(struct shash_desc *desc)
27{
28	u16 *crc = shash_desc_ctx(desc);
29
30	*crc = 0;
31	return 0;
32}
33
34static int crct10dif_update_pmull_p8(struct shash_desc *desc, const u8 *data,
35			    unsigned int length)
36{
37	u16 *crc = shash_desc_ctx(desc);
38
39	if (length >= CRC_T10DIF_PMULL_CHUNK_SIZE && crypto_simd_usable()) {
40		do {
41			unsigned int chunk = length;
42
43			if (chunk > SZ_4K + CRC_T10DIF_PMULL_CHUNK_SIZE)
44				chunk = SZ_4K;
45
46			kernel_neon_begin();
47			*crc = crc_t10dif_pmull_p8(*crc, data, chunk);
48			kernel_neon_end();
49			data += chunk;
50			length -= chunk;
51		} while (length);
52	} else {
53		*crc = crc_t10dif_generic(*crc, data, length);
54	}
55
56	return 0;
57}
58
59static int crct10dif_update_pmull_p64(struct shash_desc *desc, const u8 *data,
60			    unsigned int length)
61{
62	u16 *crc = shash_desc_ctx(desc);
63
64	if (length >= CRC_T10DIF_PMULL_CHUNK_SIZE && crypto_simd_usable()) {
65		do {
66			unsigned int chunk = length;
67
68			if (chunk > SZ_4K + CRC_T10DIF_PMULL_CHUNK_SIZE)
69				chunk = SZ_4K;
70
71			kernel_neon_begin();
72			*crc = crc_t10dif_pmull_p64(*crc, data, chunk);
73			kernel_neon_end();
74			data += chunk;
75			length -= chunk;
76		} while (length);
77	} else {
78		*crc = crc_t10dif_generic(*crc, data, length);
79	}
80
81	return 0;
82}
83
84static int crct10dif_final(struct shash_desc *desc, u8 *out)
85{
86	u16 *crc = shash_desc_ctx(desc);
87
88	*(u16 *)out = *crc;
89	return 0;
90}
91
92static struct shash_alg crc_t10dif_alg[] = {{
93	.digestsize		= CRC_T10DIF_DIGEST_SIZE,
94	.init			= crct10dif_init,
95	.update			= crct10dif_update_pmull_p8,
96	.final			= crct10dif_final,
97	.descsize		= CRC_T10DIF_DIGEST_SIZE,
98
99	.base.cra_name		= "crct10dif",
100	.base.cra_driver_name	= "crct10dif-arm64-neon",
101	.base.cra_priority	= 100,
102	.base.cra_blocksize	= CRC_T10DIF_BLOCK_SIZE,
103	.base.cra_module	= THIS_MODULE,
104}, {
105	.digestsize		= CRC_T10DIF_DIGEST_SIZE,
106	.init			= crct10dif_init,
107	.update			= crct10dif_update_pmull_p64,
108	.final			= crct10dif_final,
109	.descsize		= CRC_T10DIF_DIGEST_SIZE,
110
111	.base.cra_name		= "crct10dif",
112	.base.cra_driver_name	= "crct10dif-arm64-ce",
113	.base.cra_priority	= 200,
114	.base.cra_blocksize	= CRC_T10DIF_BLOCK_SIZE,
115	.base.cra_module	= THIS_MODULE,
116}};
117
118static int __init crc_t10dif_mod_init(void)
119{
120	if (cpu_have_named_feature(PMULL))
121		return crypto_register_shashes(crc_t10dif_alg,
122					       ARRAY_SIZE(crc_t10dif_alg));
123	else
124		/* only register the first array element */
125		return crypto_register_shash(crc_t10dif_alg);
126}
127
128static void __exit crc_t10dif_mod_exit(void)
129{
130	if (cpu_have_named_feature(PMULL))
131		crypto_unregister_shashes(crc_t10dif_alg,
132					  ARRAY_SIZE(crc_t10dif_alg));
133	else
134		crypto_unregister_shash(crc_t10dif_alg);
135}
136
137module_cpu_feature_match(ASIMD, crc_t10dif_mod_init);
138module_exit(crc_t10dif_mod_exit);
139
140MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
141MODULE_LICENSE("GPL v2");
142MODULE_ALIAS_CRYPTO("crct10dif");
143MODULE_ALIAS_CRYPTO("crct10dif-arm64-ce");
144