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Ard Biesheuvel6ef57372016-12-05 18:42:25 +00001/*
2 * Accelerated CRC-T10DIF using arm64 NEON and Crypto Extensions instructions
3 *
Ard Biesheuvel2dde3742017-07-24 11:28:06 +01004 * Copyright (C) 2016 - 2017 Linaro Ltd <ard.biesheuvel@linaro.org>
Ard Biesheuvel6ef57372016-12-05 18:42:25 +00005 *
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 <linux/cpufeature.h>
12#include <linux/crc-t10dif.h>
13#include <linux/init.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/string.h>
17
18#include <crypto/internal/hash.h>
19
20#include <asm/neon.h>
Ard Biesheuvel2dde3742017-07-24 11:28:06 +010021#include <asm/simd.h>
Ard Biesheuvel6ef57372016-12-05 18:42:25 +000022
23#define CRC_T10DIF_PMULL_CHUNK_SIZE 16U
24
25asmlinkage u16 crc_t10dif_pmull(u16 init_crc, const u8 buf[], u64 len);
26
27static int crct10dif_init(struct shash_desc *desc)
28{
29 u16 *crc = shash_desc_ctx(desc);
30
31 *crc = 0;
32 return 0;
33}
34
35static int crct10dif_update(struct shash_desc *desc, const u8 *data,
36 unsigned int length)
37{
38 u16 *crc = shash_desc_ctx(desc);
39 unsigned int l;
40
41 if (unlikely((u64)data % CRC_T10DIF_PMULL_CHUNK_SIZE)) {
42 l = min_t(u32, length, CRC_T10DIF_PMULL_CHUNK_SIZE -
43 ((u64)data % CRC_T10DIF_PMULL_CHUNK_SIZE));
44
45 *crc = crc_t10dif_generic(*crc, data, l);
46
47 length -= l;
48 data += l;
49 }
50
51 if (length > 0) {
Ard Biesheuvel2dde3742017-07-24 11:28:06 +010052 if (may_use_simd()) {
53 kernel_neon_begin();
54 *crc = crc_t10dif_pmull(*crc, data, length);
55 kernel_neon_end();
56 } else {
57 *crc = crc_t10dif_generic(*crc, data, length);
58 }
Ard Biesheuvel6ef57372016-12-05 18:42:25 +000059 }
60
61 return 0;
62}
63
64static int crct10dif_final(struct shash_desc *desc, u8 *out)
65{
66 u16 *crc = shash_desc_ctx(desc);
67
68 *(u16 *)out = *crc;
69 return 0;
70}
71
72static struct shash_alg crc_t10dif_alg = {
73 .digestsize = CRC_T10DIF_DIGEST_SIZE,
74 .init = crct10dif_init,
75 .update = crct10dif_update,
76 .final = crct10dif_final,
77 .descsize = CRC_T10DIF_DIGEST_SIZE,
78
79 .base.cra_name = "crct10dif",
80 .base.cra_driver_name = "crct10dif-arm64-ce",
81 .base.cra_priority = 200,
82 .base.cra_blocksize = CRC_T10DIF_BLOCK_SIZE,
83 .base.cra_module = THIS_MODULE,
84};
85
86static int __init crc_t10dif_mod_init(void)
87{
88 return crypto_register_shash(&crc_t10dif_alg);
89}
90
91static void __exit crc_t10dif_mod_exit(void)
92{
93 crypto_unregister_shash(&crc_t10dif_alg);
94}
95
96module_cpu_feature_match(PMULL, crc_t10dif_mod_init);
97module_exit(crc_t10dif_mod_exit);
98
99MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
100MODULE_LICENSE("GPL v2");