1 /*
2 * Accelerated CRC-T10DIF using ARM NEON and Crypto Extensions instructions
3 *
4 * Copyright (C) 2016 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/crc-t10dif.h>
12 #include <linux/init.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/string.h>
16
17 #include <crypto/internal/hash.h>
18
19 #include <asm/neon.h>
20 #include <asm/simd.h>
21
22 #define CRC_T10DIF_PMULL_CHUNK_SIZE 16U
23
24 asmlinkage u16 crc_t10dif_pmull(u16 init_crc, const u8 buf[], u32 len);
25
crct10dif_init(struct shash_desc * desc)26 static int crct10dif_init(struct shash_desc *desc)
27 {
28 u16 *crc = shash_desc_ctx(desc);
29
30 *crc = 0;
31 return 0;
32 }
33
crct10dif_update(struct shash_desc * desc,const u8 * data,unsigned int length)34 static int crct10dif_update(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 && may_use_simd()) {
40 kernel_neon_begin();
41 *crc = crc_t10dif_pmull(*crc, data, length);
42 kernel_neon_end();
43 } else {
44 *crc = crc_t10dif_generic(*crc, data, length);
45 }
46
47 return 0;
48 }
49
crct10dif_final(struct shash_desc * desc,u8 * out)50 static int crct10dif_final(struct shash_desc *desc, u8 *out)
51 {
52 u16 *crc = shash_desc_ctx(desc);
53
54 *(u16 *)out = *crc;
55 return 0;
56 }
57
58 static struct shash_alg crc_t10dif_alg = {
59 .digestsize = CRC_T10DIF_DIGEST_SIZE,
60 .init = crct10dif_init,
61 .update = crct10dif_update,
62 .final = crct10dif_final,
63 .descsize = CRC_T10DIF_DIGEST_SIZE,
64
65 .base.cra_name = "crct10dif",
66 .base.cra_driver_name = "crct10dif-arm-ce",
67 .base.cra_priority = 200,
68 .base.cra_blocksize = CRC_T10DIF_BLOCK_SIZE,
69 .base.cra_module = THIS_MODULE,
70 };
71
crc_t10dif_mod_init(void)72 static int __init crc_t10dif_mod_init(void)
73 {
74 if (!(elf_hwcap2 & HWCAP2_PMULL))
75 return -ENODEV;
76
77 return crypto_register_shash(&crc_t10dif_alg);
78 }
79
crc_t10dif_mod_exit(void)80 static void __exit crc_t10dif_mod_exit(void)
81 {
82 crypto_unregister_shash(&crc_t10dif_alg);
83 }
84
85 module_init(crc_t10dif_mod_init);
86 module_exit(crc_t10dif_mod_exit);
87
88 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
89 MODULE_LICENSE("GPL v2");
90 MODULE_ALIAS_CRYPTO("crct10dif");
91