9a5ce91d05
Start the algorithms with the very basic one. It is left and right optimized. That means we can avoid all calculations for unneeded pages above the right stop offset. For pages below the left start offset we still need the syndrome multiplication but without reading data pages. Signed-off-by: Markus Stockhausen <stockhausen@collogia.de> Signed-off-by: NeilBrown <neilb@suse.de>
157 lines
3.7 KiB
Ucode
157 lines
3.7 KiB
Ucode
/* -*- linux-c -*- ------------------------------------------------------- *
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*
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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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* int$#.c
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*
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* $#-way unrolled portable integer 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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#include <linux/raid/pq.h>
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/*
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* This is the C data type to use
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*/
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/* Change this from BITS_PER_LONG if there is something better... */
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#if BITS_PER_LONG == 64
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# define NBYTES(x) ((x) * 0x0101010101010101UL)
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# define NSIZE 8
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# define NSHIFT 3
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# define NSTRING "64"
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typedef u64 unative_t;
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#else
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# define NBYTES(x) ((x) * 0x01010101U)
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# define NSIZE 4
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# define NSHIFT 2
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# define NSTRING "32"
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typedef u32 unative_t;
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#endif
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/*
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* IA-64 wants insane amounts of unrolling. On other architectures that
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* is just a waste of space.
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*/
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#if ($# <= 8) || defined(__ia64__)
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/*
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* These sub-operations are separate inlines since they can sometimes be
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* specially optimized using architecture-specific hacks.
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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 __attribute_const__ unative_t SHLBYTE(unative_t v)
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{
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unative_t vv;
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vv = (v << 1) & NBYTES(0xfe);
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return vv;
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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 __attribute_const__ unative_t MASK(unative_t v)
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{
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unative_t vv;
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vv = v & NBYTES(0x80);
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vv = (vv << 1) - (vv >> 7); /* Overflow on the top bit is OK */
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return vv;
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}
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static void raid6_int$#_gen_syndrome(int disks, size_t bytes, void **ptrs)
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{
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u8 **dptr = (u8 **)ptrs;
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u8 *p, *q;
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int d, z, z0;
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unative_t wd$$, wq$$, wp$$, w1$$, w2$$;
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z0 = disks - 3; /* Highest data disk */
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p = dptr[z0+1]; /* XOR parity */
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q = dptr[z0+2]; /* RS syndrome */
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for ( d = 0 ; d < bytes ; d += NSIZE*$# ) {
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wq$$ = wp$$ = *(unative_t *)&dptr[z0][d+$$*NSIZE];
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for ( z = z0-1 ; z >= 0 ; z-- ) {
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wd$$ = *(unative_t *)&dptr[z][d+$$*NSIZE];
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wp$$ ^= wd$$;
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w2$$ = MASK(wq$$);
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w1$$ = SHLBYTE(wq$$);
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w2$$ &= NBYTES(0x1d);
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w1$$ ^= w2$$;
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wq$$ = w1$$ ^ wd$$;
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}
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*(unative_t *)&p[d+NSIZE*$$] = wp$$;
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*(unative_t *)&q[d+NSIZE*$$] = wq$$;
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}
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}
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static void raid6_int$#_xor_syndrome(int disks, int start, int stop,
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size_t bytes, void **ptrs)
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{
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u8 **dptr = (u8 **)ptrs;
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u8 *p, *q;
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int d, z, z0;
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unative_t wd$$, wq$$, wp$$, w1$$, w2$$;
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z0 = stop; /* P/Q right side optimization */
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p = dptr[disks-2]; /* XOR parity */
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q = dptr[disks-1]; /* RS syndrome */
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for ( d = 0 ; d < bytes ; d += NSIZE*$# ) {
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/* P/Q data pages */
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wq$$ = wp$$ = *(unative_t *)&dptr[z0][d+$$*NSIZE];
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for ( z = z0-1 ; z >= start ; z-- ) {
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wd$$ = *(unative_t *)&dptr[z][d+$$*NSIZE];
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wp$$ ^= wd$$;
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w2$$ = MASK(wq$$);
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w1$$ = SHLBYTE(wq$$);
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w2$$ &= NBYTES(0x1d);
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w1$$ ^= w2$$;
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wq$$ = w1$$ ^ wd$$;
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}
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/* P/Q left side optimization */
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for ( z = start-1 ; z >= 0 ; z-- ) {
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w2$$ = MASK(wq$$);
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w1$$ = SHLBYTE(wq$$);
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w2$$ &= NBYTES(0x1d);
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wq$$ = w1$$ ^ w2$$;
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}
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*(unative_t *)&p[d+NSIZE*$$] ^= wp$$;
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*(unative_t *)&q[d+NSIZE*$$] ^= wq$$;
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}
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}
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const struct raid6_calls raid6_intx$# = {
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raid6_int$#_gen_syndrome,
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raid6_int$#_xor_syndrome,
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NULL, /* always valid */
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"int" NSTRING "x$#",
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0
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};
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#endif
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