xref: /openbmc/linux/lib/raid6/neon.c (revision 7effbd18)
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/neon.h>
12 #else
13 #define kernel_neon_begin()
14 #define kernel_neon_end()
15 #define cpu_has_neon()		(1)
16 #endif
17 
18 /*
19  * There are 2 reasons these wrappers are kept in a separate compilation unit
20  * from the actual implementations in neonN.c (generated from neon.uc by
21  * unroll.awk):
22  * - the actual implementations use NEON intrinsics, and the GCC support header
23  *   (arm_neon.h) is not fully compatible (type wise) with the kernel;
24  * - the neonN.c files are compiled with -mfpu=neon and optimization enabled,
25  *   and we have to make sure that we never use *any* NEON/VFP instructions
26  *   outside a kernel_neon_begin()/kernel_neon_end() pair.
27  */
28 
29 #define RAID6_NEON_WRAPPER(_n)						\
30 	static void raid6_neon ## _n ## _gen_syndrome(int disks,	\
31 					size_t bytes, void **ptrs)	\
32 	{								\
33 		void raid6_neon ## _n  ## _gen_syndrome_real(int,	\
34 						unsigned long, void**);	\
35 		kernel_neon_begin();					\
36 		raid6_neon ## _n ## _gen_syndrome_real(disks,		\
37 					(unsigned long)bytes, ptrs);	\
38 		kernel_neon_end();					\
39 	}								\
40 	static void raid6_neon ## _n ## _xor_syndrome(int disks,	\
41 					int start, int stop, 		\
42 					size_t bytes, void **ptrs)	\
43 	{								\
44 		void raid6_neon ## _n  ## _xor_syndrome_real(int,	\
45 				int, int, unsigned long, void**);	\
46 		kernel_neon_begin();					\
47 		raid6_neon ## _n ## _xor_syndrome_real(disks,		\
48 			start, stop, (unsigned long)bytes, ptrs);	\
49 		kernel_neon_end();					\
50 	}								\
51 	struct raid6_calls const raid6_neonx ## _n = {			\
52 		raid6_neon ## _n ## _gen_syndrome,			\
53 		raid6_neon ## _n ## _xor_syndrome,			\
54 		raid6_have_neon,					\
55 		"neonx" #_n,						\
56 		0							\
57 	}
58 
59 static int raid6_have_neon(void)
60 {
61 	return cpu_has_neon();
62 }
63 
64 RAID6_NEON_WRAPPER(1);
65 RAID6_NEON_WRAPPER(2);
66 RAID6_NEON_WRAPPER(4);
67 RAID6_NEON_WRAPPER(8);
68