 7d11965ddb
			
		
	
	
	7d11965ddb
	
	
	
		
			
			Rebased/reworked a patch contributed by Rob Herring that uses NEON intrinsics to perform the RAID-6 syndrome calculations. It uses the existing unroll.awk code to generate several unrolled versions of which the best performing one is selected at boot time. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Nicolas Pitre <nico@linaro.org> Cc: hpa@linux.intel.com
		
			
				
	
	
		
			80 lines
		
	
	
	
		
			2.2 KiB
			
		
	
	
	
		
			Ucode
		
	
	
	
	
	
			
		
		
	
	
			80 lines
		
	
	
	
		
			2.2 KiB
			
		
	
	
	
		
			Ucode
		
	
	
	
	
	
| /* -----------------------------------------------------------------------
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|  *
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|  *   neon.uc - RAID-6 syndrome calculation using ARM NEON instructions
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|  *
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|  *   Copyright (C) 2012 Rob Herring
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|  *
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|  *   Based on altivec.uc:
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|  *     Copyright 2002-2004 H. Peter Anvin - All Rights Reserved
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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 as published by
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|  *   the Free Software Foundation, Inc., 53 Temple Place Ste 330,
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|  *   Boston MA 02111-1307, USA; either version 2 of the License, or
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|  *   (at your option) any later version; incorporated herein by reference.
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|  *
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|  * ----------------------------------------------------------------------- */
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| 
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| /*
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|  * neon$#.c
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|  *
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|  * $#-way unrolled NEON intrinsics math RAID-6 instruction set
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|  *
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|  * This file is postprocessed using unroll.awk
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|  */
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| 
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| #include <arm_neon.h>
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| 
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| typedef uint8x16_t unative_t;
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| 
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| #define NBYTES(x) ((unative_t){x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,x})
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| #define NSIZE	sizeof(unative_t)
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| 
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| /*
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|  * The SHLBYTE() operation shifts each byte left by 1, *not*
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|  * rolling over into the next byte
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|  */
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| static inline unative_t SHLBYTE(unative_t v)
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| {
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| 	return vshlq_n_u8(v, 1);
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| }
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| 
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| /*
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|  * The MASK() operation returns 0xFF in any byte for which the high
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|  * bit is 1, 0x00 for any byte for which the high bit is 0.
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|  */
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| static inline unative_t MASK(unative_t v)
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| {
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| 	const uint8x16_t temp = NBYTES(0);
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| 	return (unative_t)vcltq_s8((int8x16_t)v, (int8x16_t)temp);
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| }
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| 
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| void raid6_neon$#_gen_syndrome_real(int disks, unsigned long bytes, void **ptrs)
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| {
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| 	uint8_t **dptr = (uint8_t **)ptrs;
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| 	uint8_t *p, *q;
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| 	int d, z, z0;
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| 
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| 	register unative_t wd$$, wq$$, wp$$, w1$$, w2$$;
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| 	const unative_t x1d = NBYTES(0x1d);
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| 
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| 	z0 = disks - 3;		/* Highest data disk */
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| 	p = dptr[z0+1];		/* XOR parity */
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| 	q = dptr[z0+2];		/* RS syndrome */
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| 
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| 	for ( d = 0 ; d < bytes ; d += NSIZE*$# ) {
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| 		wq$$ = wp$$ = vld1q_u8(&dptr[z0][d+$$*NSIZE]);
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| 		for ( z = z0-1 ; z >= 0 ; z-- ) {
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| 			wd$$ = vld1q_u8(&dptr[z][d+$$*NSIZE]);
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| 			wp$$ = veorq_u8(wp$$, wd$$);
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| 			w2$$ = MASK(wq$$);
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| 			w1$$ = SHLBYTE(wq$$);
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| 
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| 			w2$$ = vandq_u8(w2$$, x1d);
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| 			w1$$ = veorq_u8(w1$$, w2$$);
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| 			wq$$ = veorq_u8(w1$$, wd$$);
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| 		}
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| 		vst1q_u8(&p[d+NSIZE*$$], wp$$);
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| 		vst1q_u8(&q[d+NSIZE*$$], wq$$);
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| 	}
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| }
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