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Linux kernel mirror (for testing)
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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/simd.h>
15
16#include <asm/neon.h>
17#include <asm/simd.h>
18
19static DEFINE_STATIC_KEY_FALSE(have_neon);
20static DEFINE_STATIC_KEY_FALSE(have_pmull);
21
22#define CRC_T10DIF_PMULL_CHUNK_SIZE 16U
23
24asmlinkage u16 crc_t10dif_pmull64(u16 init_crc, const u8 *buf, size_t len);
25asmlinkage void crc_t10dif_pmull8(u16 init_crc, const u8 *buf, size_t len,
26 u8 out[16]);
27
28u16 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 crc = 0;
48 data = buf;
49 length = sizeof(buf);
50 }
51 }
52 return crc_t10dif_generic(crc, data, length);
53}
54EXPORT_SYMBOL(crc_t10dif_arch);
55
56static int __init crc_t10dif_arm_init(void)
57{
58 if (elf_hwcap & HWCAP_NEON) {
59 static_branch_enable(&have_neon);
60 if (elf_hwcap2 & HWCAP2_PMULL)
61 static_branch_enable(&have_pmull);
62 }
63 return 0;
64}
65arch_initcall(crc_t10dif_arm_init);
66
67static void __exit crc_t10dif_arm_exit(void)
68{
69}
70module_exit(crc_t10dif_arm_exit);
71
72bool crc_t10dif_is_optimized(void)
73{
74 return static_key_enabled(&have_neon);
75}
76EXPORT_SYMBOL(crc_t10dif_is_optimized);
77
78MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
79MODULE_DESCRIPTION("Accelerated CRC-T10DIF using ARM NEON and Crypto Extensions");
80MODULE_LICENSE("GPL v2");