xref: /linux/lib/crc/arm/crc-t10dif.h (revision 68a052239fc4b351e961f698b824f7654a346091)
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 <asm/neon.h>
9 #include <asm/simd.h>
10 
11 static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon);
12 static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_pmull);
13 
14 #define CRC_T10DIF_PMULL_CHUNK_SIZE	16U
15 
16 asmlinkage u16 crc_t10dif_pmull64(u16 init_crc, const u8 *buf, size_t len);
17 asmlinkage void crc_t10dif_pmull8(u16 init_crc, const u8 *buf, size_t len,
18 				  u8 out[16]);
19 
20 static inline u16 crc_t10dif_arch(u16 crc, const u8 *data, size_t length)
21 {
22 	if (length >= CRC_T10DIF_PMULL_CHUNK_SIZE) {
23 		if (static_branch_likely(&have_pmull)) {
24 			if (likely(may_use_simd())) {
25 				kernel_neon_begin();
26 				crc = crc_t10dif_pmull64(crc, data, length);
27 				kernel_neon_end();
28 				return crc;
29 			}
30 		} else if (length > CRC_T10DIF_PMULL_CHUNK_SIZE &&
31 			   static_branch_likely(&have_neon) &&
32 			   likely(may_use_simd())) {
33 			u8 buf[16] __aligned(16);
34 
35 			kernel_neon_begin();
36 			crc_t10dif_pmull8(crc, data, length, buf);
37 			kernel_neon_end();
38 
39 			return crc_t10dif_generic(0, buf, sizeof(buf));
40 		}
41 	}
42 	return crc_t10dif_generic(crc, data, length);
43 }
44 
45 #define crc_t10dif_mod_init_arch crc_t10dif_mod_init_arch
46 static void crc_t10dif_mod_init_arch(void)
47 {
48 	if (elf_hwcap & HWCAP_NEON) {
49 		static_branch_enable(&have_neon);
50 		if (elf_hwcap2 & HWCAP2_PMULL)
51 			static_branch_enable(&have_pmull);
52 	}
53 }
54