forked from mirrors/linux
		
	This implements XOR syndrome calculation using NEON intrinsics. As before, the module can be built for ARM and arm64 from the same source. Relative performance on a Cortex-A57 based system: raid6: int64x1 gen() 905 MB/s raid6: int64x1 xor() 881 MB/s raid6: int64x2 gen() 1343 MB/s raid6: int64x2 xor() 1286 MB/s raid6: int64x4 gen() 1896 MB/s raid6: int64x4 xor() 1321 MB/s raid6: int64x8 gen() 1773 MB/s raid6: int64x8 xor() 1165 MB/s raid6: neonx1 gen() 1834 MB/s raid6: neonx1 xor() 1278 MB/s raid6: neonx2 gen() 2528 MB/s raid6: neonx2 xor() 1942 MB/s raid6: neonx4 gen() 2888 MB/s raid6: neonx4 xor() 2334 MB/s raid6: neonx8 gen() 2957 MB/s raid6: neonx8 xor() 2232 MB/s raid6: using algorithm neonx8 gen() 2957 MB/s raid6: .... xor() 2232 MB/s, rmw enabled Cc: Markus Stockhausen <stockhausen@collogia.de> Cc: Neil Brown <neilb@suse.de> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: NeilBrown <neilb@suse.com>
		
			
				
	
	
		
			70 lines
		
	
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			70 lines
		
	
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * linux/lib/raid6/neon.c - RAID6 syndrome calculation using ARM NEON intrinsics
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 *
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 * Copyright (C) 2013 Linaro Ltd <ard.biesheuvel@linaro.org>
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 *
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 * This program is free software; you can redistribute it and/or modify
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 * it under the terms of the GNU General Public License version 2 as
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 * published by the Free Software Foundation.
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 */
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#include <linux/raid/pq.h>
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#ifdef __KERNEL__
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#include <asm/neon.h>
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#else
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#define kernel_neon_begin()
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#define kernel_neon_end()
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#define cpu_has_neon()		(1)
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#endif
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/*
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 * There are 2 reasons these wrappers are kept in a separate compilation unit
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 * from the actual implementations in neonN.c (generated from neon.uc by
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 * unroll.awk):
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 * - the actual implementations use NEON intrinsics, and the GCC support header
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 *   (arm_neon.h) is not fully compatible (type wise) with the kernel;
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 * - the neonN.c files are compiled with -mfpu=neon and optimization enabled,
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 *   and we have to make sure that we never use *any* NEON/VFP instructions
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 *   outside a kernel_neon_begin()/kernel_neon_end() pair.
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 */
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#define RAID6_NEON_WRAPPER(_n)						\
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	static void raid6_neon ## _n ## _gen_syndrome(int disks,	\
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					size_t bytes, void **ptrs)	\
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	{								\
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		void raid6_neon ## _n  ## _gen_syndrome_real(int,	\
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						unsigned long, void**);	\
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		kernel_neon_begin();					\
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		raid6_neon ## _n ## _gen_syndrome_real(disks,		\
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					(unsigned long)bytes, ptrs);	\
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		kernel_neon_end();					\
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	}								\
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	static void raid6_neon ## _n ## _xor_syndrome(int disks,	\
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					int start, int stop, 		\
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					size_t bytes, void **ptrs)	\
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	{								\
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		void raid6_neon ## _n  ## _xor_syndrome_real(int,	\
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				int, int, unsigned long, void**);	\
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		kernel_neon_begin();					\
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		raid6_neon ## _n ## _xor_syndrome_real(disks,		\
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			start, stop, (unsigned long)bytes, ptrs);	\
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		kernel_neon_end();					\
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	}								\
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	struct raid6_calls const raid6_neonx ## _n = {			\
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		raid6_neon ## _n ## _gen_syndrome,			\
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		raid6_neon ## _n ## _xor_syndrome,			\
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		raid6_have_neon,					\
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		"neonx" #_n,						\
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		0							\
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	}
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static int raid6_have_neon(void)
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{
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	return cpu_has_neon();
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}
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RAID6_NEON_WRAPPER(1);
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RAID6_NEON_WRAPPER(2);
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RAID6_NEON_WRAPPER(4);
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RAID6_NEON_WRAPPER(8);
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