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
22 asmlinkage u16 crc_t10dif_pmull(u16 init_crc, const u8 *buf, size_t len);
23
24 static int crct10dif_init(struct shash_desc *desc)
25 {
26 u16 *crc = shash_desc_ctx(desc);
27
28 *crc = 0;
29 return 0;
30 }
31
32 static 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
48 static 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
56 static 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
70 static 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
78 static void __exit crc_t10dif_mod_exit(void)
79 {
80 crypto_unregister_shash(&crc_t10dif_alg);
81 }
82
83 module_init(crc_t10dif_mod_init);
84 module_exit(crc_t10dif_mod_exit);
85
86 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
87 MODULE_DESCRIPTION("Accelerated CRC-T10DIF using ARM NEON and Crypto Extensions");
88 MODULE_LICENSE("GPL v2");
89 MODULE_ALIAS_CRYPTO("crct10dif");
90
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