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 <[email protected]>
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/simd.h>
15
16 #include <asm/neon.h>
17 #include <asm/simd.h>
18
19 static DEFINE_STATIC_KEY_FALSE(have_neon);
20 static DEFINE_STATIC_KEY_FALSE(have_pmull);
21
22 #define CRC_T10DIF_PMULL_CHUNK_SIZE 16U
23
24 asmlinkage u16 crc_t10dif_pmull64(u16 init_crc, const u8 *buf, size_t len);
25 asmlinkage void crc_t10dif_pmull8(u16 init_crc, const u8 *buf, size_t len,
26 u8 out[16]);
27
crc_t10dif_arch(u16 crc,const u8 * data,size_t length)28 u16 crc_t10dif_arch(u16 crc, const u8 *data, size_t length)
29 {
30 if (length >= CRC_T10DIF_PMULL_CHUNK_SIZE) {
31 if (static_branch_likely(&have_pmull)) {
32 if (crypto_simd_usable()) {
33 kernel_neon_begin();
34 crc = crc_t10dif_pmull64(crc, data, length);
35 kernel_neon_end();
36 return crc;
37 }
38 } else if (length > CRC_T10DIF_PMULL_CHUNK_SIZE &&
39 static_branch_likely(&have_neon) &&
40 crypto_simd_usable()) {
41 u8 buf[16] __aligned(16);
42
43 kernel_neon_begin();
44 crc_t10dif_pmull8(crc, data, length, buf);
45 kernel_neon_end();
46
47 return crc_t10dif_generic(0, buf, sizeof(buf));
48 }
49 }
50 return crc_t10dif_generic(crc, data, length);
51 }
52 EXPORT_SYMBOL(crc_t10dif_arch);
53
crc_t10dif_arm_init(void)54 static int __init crc_t10dif_arm_init(void)
55 {
56 if (elf_hwcap & HWCAP_NEON) {
57 static_branch_enable(&have_neon);
58 if (elf_hwcap2 & HWCAP2_PMULL)
59 static_branch_enable(&have_pmull);
60 }
61 return 0;
62 }
63 arch_initcall(crc_t10dif_arm_init);
64
crc_t10dif_arm_exit(void)65 static void __exit crc_t10dif_arm_exit(void)
66 {
67 }
68 module_exit(crc_t10dif_arm_exit);
69
crc_t10dif_is_optimized(void)70 bool crc_t10dif_is_optimized(void)
71 {
72 return static_key_enabled(&have_neon);
73 }
74 EXPORT_SYMBOL(crc_t10dif_is_optimized);
75
76 MODULE_AUTHOR("Ard Biesheuvel <[email protected]>");
77 MODULE_DESCRIPTION("Accelerated CRC-T10DIF using ARM NEON and Crypto Extensions");
78 MODULE_LICENSE("GPL v2");
79