xref: /linux/lib/raid6/neon.c (revision 7fc2cd2e4b398c57c9cf961cfea05eadbf34c05c)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * linux/lib/raid6/neon.c - RAID6 syndrome calculation using ARM NEON intrinsics
4  *
5  * Copyright (C) 2013 Linaro Ltd <ard.biesheuvel@linaro.org>
6  */
7 
8 #include <linux/raid/pq.h>
9 
10 #ifdef __KERNEL__
11 #include <asm/simd.h>
12 #else
13 #define scoped_ksimd()
14 #define cpu_has_neon()		(1)
15 #endif
16 
17 /*
18  * There are 2 reasons these wrappers are kept in a separate compilation unit
19  * from the actual implementations in neonN.c (generated from neon.uc by
20  * unroll.awk):
21  * - the actual implementations use NEON intrinsics, and the GCC support header
22  *   (arm_neon.h) is not fully compatible (type wise) with the kernel;
23  * - the neonN.c files are compiled with -mfpu=neon and optimization enabled,
24  *   and we have to make sure that we never use *any* NEON/VFP instructions
25  *   outside a kernel_neon_begin()/kernel_neon_end() pair.
26  */
27 
28 #define RAID6_NEON_WRAPPER(_n)						\
29 	static void raid6_neon ## _n ## _gen_syndrome(int disks,	\
30 					size_t bytes, void **ptrs)	\
31 	{								\
32 		void raid6_neon ## _n  ## _gen_syndrome_real(int,	\
33 						unsigned long, void**);	\
34 		scoped_ksimd()						\
35 			raid6_neon ## _n ## _gen_syndrome_real(disks,	\
36 					(unsigned long)bytes, ptrs);	\
37 	}								\
38 	static void raid6_neon ## _n ## _xor_syndrome(int disks,	\
39 					int start, int stop, 		\
40 					size_t bytes, void **ptrs)	\
41 	{								\
42 		void raid6_neon ## _n  ## _xor_syndrome_real(int,	\
43 				int, int, unsigned long, void**);	\
44 		scoped_ksimd()						\
45 			raid6_neon ## _n ## _xor_syndrome_real(disks,	\
46 				start, stop, (unsigned long)bytes, ptrs);\
47 	}								\
48 	struct raid6_calls const raid6_neonx ## _n = {			\
49 		raid6_neon ## _n ## _gen_syndrome,			\
50 		raid6_neon ## _n ## _xor_syndrome,			\
51 		raid6_have_neon,					\
52 		"neonx" #_n,						\
53 		0							\
54 	}
55 
56 static int raid6_have_neon(void)
57 {
58 	return cpu_has_neon();
59 }
60 
61 RAID6_NEON_WRAPPER(1);
62 RAID6_NEON_WRAPPER(2);
63 RAID6_NEON_WRAPPER(4);
64 RAID6_NEON_WRAPPER(8);
65