tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Accelerated CRC-T10DIF using arm64 NEON and Crypto Extensions instructions
3 *
4 * Copyright (C) 2016 - 2017 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 <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>
21#include <asm/simd.h>
22
23#define CRC_T10DIF_PMULL_CHUNK_SIZE 16U
24
25asmlinkage u16 crc_t10dif_pmull_p64(u16 init_crc, const u8 buf[], u64 len);
26asmlinkage u16 crc_t10dif_pmull_p8(u16 init_crc, const u8 buf[], u64 len);
27
28static u16 (*crc_t10dif_pmull)(u16 init_crc, const u8 buf[], u64 len);
29
30static int crct10dif_init(struct shash_desc *desc)
31{
32 u16 *crc = shash_desc_ctx(desc);
33
34 *crc = 0;
35 return 0;
36}
37
38static int crct10dif_update(struct shash_desc *desc, const u8 *data,
39 unsigned int length)
40{
41 u16 *crc = shash_desc_ctx(desc);
42 unsigned int l;
43
44 if (unlikely((u64)data % CRC_T10DIF_PMULL_CHUNK_SIZE)) {
45 l = min_t(u32, length, CRC_T10DIF_PMULL_CHUNK_SIZE -
46 ((u64)data % CRC_T10DIF_PMULL_CHUNK_SIZE));
47
48 *crc = crc_t10dif_generic(*crc, data, l);
49
50 length -= l;
51 data += l;
52 }
53
54 if (length > 0) {
55 if (may_use_simd()) {
56 kernel_neon_begin();
57 *crc = crc_t10dif_pmull(*crc, data, length);
58 kernel_neon_end();
59 } else {
60 *crc = crc_t10dif_generic(*crc, data, length);
61 }
62 }
63
64 return 0;
65}
66
67static int crct10dif_final(struct shash_desc *desc, u8 *out)
68{
69 u16 *crc = shash_desc_ctx(desc);
70
71 *(u16 *)out = *crc;
72 return 0;
73}
74
75static struct shash_alg crc_t10dif_alg = {
76 .digestsize = CRC_T10DIF_DIGEST_SIZE,
77 .init = crct10dif_init,
78 .update = crct10dif_update,
79 .final = crct10dif_final,
80 .descsize = CRC_T10DIF_DIGEST_SIZE,
81
82 .base.cra_name = "crct10dif",
83 .base.cra_driver_name = "crct10dif-arm64-ce",
84 .base.cra_priority = 200,
85 .base.cra_blocksize = CRC_T10DIF_BLOCK_SIZE,
86 .base.cra_module = THIS_MODULE,
87};
88
89static int __init crc_t10dif_mod_init(void)
90{
91 if (elf_hwcap & HWCAP_PMULL)
92 crc_t10dif_pmull = crc_t10dif_pmull_p64;
93 else
94 crc_t10dif_pmull = crc_t10dif_pmull_p8;
95
96 return crypto_register_shash(&crc_t10dif_alg);
97}
98
99static void __exit crc_t10dif_mod_exit(void)
100{
101 crypto_unregister_shash(&crc_t10dif_alg);
102}
103
104module_cpu_feature_match(ASIMD, crc_t10dif_mod_init);
105module_exit(crc_t10dif_mod_exit);
106
107MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
108MODULE_LICENSE("GPL v2");
109MODULE_ALIAS_CRYPTO("crct10dif");
110MODULE_ALIAS_CRYPTO("crct10dif-arm64-ce");