1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Accelerated CRC-T10DIF using ARM NEON and Crypto Extensions instructions
4 *
5 * Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@linaro.org>
6 */
7
8#include <linux/crc-t10dif.h>
9#include <linux/init.h>
10#include <linux/kernel.h>
11#include <linux/module.h>
12#include <linux/string.h>
13
14#include <crypto/internal/hash.h>
15#include <crypto/internal/simd.h>
16
17#include <asm/neon.h>
18#include <asm/simd.h>
19
20#define CRC_T10DIF_PMULL_CHUNK_SIZE	16U
21
22asmlinkage u16 crc_t10dif_pmull(u16 init_crc, const u8 *buf, size_t len);
23
24static int crct10dif_init(struct shash_desc *desc)
25{
26	u16 *crc = shash_desc_ctx(desc);
27
28	*crc = 0;
29	return 0;
30}
31
32static int crct10dif_update(struct shash_desc *desc, const u8 *data,
33			    unsigned int length)
34{
35	u16 *crc = shash_desc_ctx(desc);
36
37	if (length >= CRC_T10DIF_PMULL_CHUNK_SIZE && crypto_simd_usable()) {
38		kernel_neon_begin();
39		*crc = crc_t10dif_pmull(*crc, data, length);
40		kernel_neon_end();
41	} else {
42		*crc = crc_t10dif_generic(*crc, data, length);
43	}
44
45	return 0;
46}
47
48static int crct10dif_final(struct shash_desc *desc, u8 *out)
49{
50	u16 *crc = shash_desc_ctx(desc);
51
52	*(u16 *)out = *crc;
53	return 0;
54}
55
56static struct shash_alg crc_t10dif_alg = {
57	.digestsize		= CRC_T10DIF_DIGEST_SIZE,
58	.init			= crct10dif_init,
59	.update			= crct10dif_update,
60	.final			= crct10dif_final,
61	.descsize		= CRC_T10DIF_DIGEST_SIZE,
62
63	.base.cra_name		= "crct10dif",
64	.base.cra_driver_name	= "crct10dif-arm-ce",
65	.base.cra_priority	= 200,
66	.base.cra_blocksize	= CRC_T10DIF_BLOCK_SIZE,
67	.base.cra_module	= THIS_MODULE,
68};
69
70static int __init crc_t10dif_mod_init(void)
71{
72	if (!(elf_hwcap2 & HWCAP2_PMULL))
73		return -ENODEV;
74
75	return crypto_register_shash(&crc_t10dif_alg);
76}
77
78static void __exit crc_t10dif_mod_exit(void)
79{
80	crypto_unregister_shash(&crc_t10dif_alg);
81}
82
83module_init(crc_t10dif_mod_init);
84module_exit(crc_t10dif_mod_exit);
85
86MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
87MODULE_LICENSE("GPL v2");
88MODULE_ALIAS_CRYPTO("crct10dif");
89