crc-t10dif.h

 1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * Accelerated CRC-T10DIF using arm64 NEON and Crypto Extensions instructions
 4 *
 5 * Copyright (C) 2016 - 2017 Linaro Ltd <ard.biesheuvel@linaro.org>
 6 */
 7
 8#include <linux/cpufeature.h>
 9
10#include <asm/simd.h>
11
12static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_asimd);
13static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_pmull);
14
15#define CRC_T10DIF_PMULL_CHUNK_SIZE	16U
16
17asmlinkage void crc_t10dif_pmull_p8(u16 init_crc, const u8 *buf, size_t len,
18				    u8 out[16]);
19asmlinkage u16 crc_t10dif_pmull_p64(u16 init_crc, const u8 *buf, size_t len);
20
21static inline u16 crc_t10dif_arch(u16 crc, const u8 *data, size_t length)
22{
23	if (length >= CRC_T10DIF_PMULL_CHUNK_SIZE && likely(may_use_simd())) {
24		if (static_branch_likely(&have_pmull)) {
25			scoped_ksimd()
26				return crc_t10dif_pmull_p64(crc, data, length);
27		} else if (length > CRC_T10DIF_PMULL_CHUNK_SIZE &&
28			   static_branch_likely(&have_asimd)) {
29			u8 buf[16];
30
31			scoped_ksimd()
32				crc_t10dif_pmull_p8(crc, data, length, buf);
33
34			return crc_t10dif_generic(0, buf, sizeof(buf));
35		}
36	}
37	return crc_t10dif_generic(crc, data, length);
38}
39
40#define crc_t10dif_mod_init_arch crc_t10dif_mod_init_arch
41static void crc_t10dif_mod_init_arch(void)
42{
43	if (cpu_have_named_feature(ASIMD)) {
44		static_branch_enable(&have_asimd);
45		if (cpu_have_named_feature(PMULL))
46			static_branch_enable(&have_pmull);
47	}
48}