• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  * linux/lib/raid6/neon.c - RAID6 syndrome calculation using ARM NEON intrinsics
3  *
4  * Copyright (C) 2013 Linaro Ltd <ard.biesheuvel@linaro.org>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10 
11 #include <linux/raid/pq.h>
12 
13 #ifdef __KERNEL__
14 #include <asm/neon.h>
15 #else
16 #define kernel_neon_begin()
17 #define kernel_neon_end()
18 #define cpu_has_neon()		(1)
19 #endif
20 
21 /*
22  * There are 2 reasons these wrappers are kept in a separate compilation unit
23  * from the actual implementations in neonN.c (generated from neon.uc by
24  * unroll.awk):
25  * - the actual implementations use NEON intrinsics, and the GCC support header
26  *   (arm_neon.h) is not fully compatible (type wise) with the kernel;
27  * - the neonN.c files are compiled with -mfpu=neon and optimization enabled,
28  *   and we have to make sure that we never use *any* NEON/VFP instructions
29  *   outside a kernel_neon_begin()/kernel_neon_end() pair.
30  */
31 
32 #define RAID6_NEON_WRAPPER(_n)						\
33 	static void raid6_neon ## _n ## _gen_syndrome(int disks,	\
34 					size_t bytes, void **ptrs)	\
35 	{								\
36 		void raid6_neon ## _n  ## _gen_syndrome_real(int,	\
37 						unsigned long, void**);	\
38 		kernel_neon_begin();					\
39 		raid6_neon ## _n ## _gen_syndrome_real(disks,		\
40 					(unsigned long)bytes, ptrs);	\
41 		kernel_neon_end();					\
42 	}								\
43 	static void raid6_neon ## _n ## _xor_syndrome(int disks,	\
44 					int start, int stop, 		\
45 					size_t bytes, void **ptrs)	\
46 	{								\
47 		void raid6_neon ## _n  ## _xor_syndrome_real(int,	\
48 				int, int, unsigned long, void**);	\
49 		kernel_neon_begin();					\
50 		raid6_neon ## _n ## _xor_syndrome_real(disks,		\
51 			start, stop, (unsigned long)bytes, ptrs);	\
52 		kernel_neon_end();					\
53 	}								\
54 	struct raid6_calls const raid6_neonx ## _n = {			\
55 		raid6_neon ## _n ## _gen_syndrome,			\
56 		raid6_neon ## _n ## _xor_syndrome,			\
57 		raid6_have_neon,					\
58 		"neonx" #_n,						\
59 		0							\
60 	}
61 
raid6_have_neon(void)62 static int raid6_have_neon(void)
63 {
64 	return cpu_has_neon();
65 }
66 
67 RAID6_NEON_WRAPPER(1);
68 RAID6_NEON_WRAPPER(2);
69 RAID6_NEON_WRAPPER(4);
70 RAID6_NEON_WRAPPER(8);
71