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Diffstat (limited to '')
| -rw-r--r-- | lib/raid6/int.uc | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/lib/raid6/int.uc b/lib/raid6/int.uc new file mode 100644 index 000000000..558aeac93 --- /dev/null +++ b/lib/raid6/int.uc @@ -0,0 +1,156 @@ +/* -*- linux-c -*- ------------------------------------------------------- * + * + * Copyright 2002-2004 H. Peter Anvin - All Rights Reserved + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, Inc., 53 Temple Place Ste 330, + * Boston MA 02111-1307, USA; either version 2 of the License, or + * (at your option) any later version; incorporated herein by reference. + * + * ----------------------------------------------------------------------- */ + +/* + * int$#.c + * + * $#-way unrolled portable integer math RAID-6 instruction set + * + * This file is postprocessed using unroll.awk + */ + +#include <linux/raid/pq.h> + +/* + * This is the C data type to use + */ + +/* Change this from BITS_PER_LONG if there is something better... */ +#if BITS_PER_LONG == 64 +# define NBYTES(x) ((x) * 0x0101010101010101UL) +# define NSIZE 8 +# define NSHIFT 3 +# define NSTRING "64" +typedef u64 unative_t; +#else +# define NBYTES(x) ((x) * 0x01010101U) +# define NSIZE 4 +# define NSHIFT 2 +# define NSTRING "32" +typedef u32 unative_t; +#endif + + + +/* + * IA-64 wants insane amounts of unrolling. On other architectures that + * is just a waste of space. + */ +#if ($# <= 8) || defined(__ia64__) + + +/* + * These sub-operations are separate inlines since they can sometimes be + * specially optimized using architecture-specific hacks. + */ + +/* + * The SHLBYTE() operation shifts each byte left by 1, *not* + * rolling over into the next byte + */ +static inline __attribute_const__ unative_t SHLBYTE(unative_t v) +{ + unative_t vv; + + vv = (v << 1) & NBYTES(0xfe); + return vv; +} + +/* + * The MASK() operation returns 0xFF in any byte for which the high + * bit is 1, 0x00 for any byte for which the high bit is 0. + */ +static inline __attribute_const__ unative_t MASK(unative_t v) +{ + unative_t vv; + + vv = v & NBYTES(0x80); + vv = (vv << 1) - (vv >> 7); /* Overflow on the top bit is OK */ + return vv; +} + + +static void raid6_int$#_gen_syndrome(int disks, size_t bytes, void **ptrs) +{ + u8 **dptr = (u8 **)ptrs; + u8 *p, *q; + int d, z, z0; + + unative_t wd$$, wq$$, wp$$, w1$$, w2$$; + + z0 = disks - 3; /* Highest data disk */ + p = dptr[z0+1]; /* XOR parity */ + q = dptr[z0+2]; /* RS syndrome */ + + for ( d = 0 ; d < bytes ; d += NSIZE*$# ) { + wq$$ = wp$$ = *(unative_t *)&dptr[z0][d+$$*NSIZE]; + for ( z = z0-1 ; z >= 0 ; z-- ) { + wd$$ = *(unative_t *)&dptr[z][d+$$*NSIZE]; + wp$$ ^= wd$$; + w2$$ = MASK(wq$$); + w1$$ = SHLBYTE(wq$$); + w2$$ &= NBYTES(0x1d); + w1$$ ^= w2$$; + wq$$ = w1$$ ^ wd$$; + } + *(unative_t *)&p[d+NSIZE*$$] = wp$$; + *(unative_t *)&q[d+NSIZE*$$] = wq$$; + } +} + +static void raid6_int$#_xor_syndrome(int disks, int start, int stop, + size_t bytes, void **ptrs) +{ + u8 **dptr = (u8 **)ptrs; + u8 *p, *q; + int d, z, z0; + + unative_t wd$$, wq$$, wp$$, w1$$, w2$$; + + z0 = stop; /* P/Q right side optimization */ + p = dptr[disks-2]; /* XOR parity */ + q = dptr[disks-1]; /* RS syndrome */ + + for ( d = 0 ; d < bytes ; d += NSIZE*$# ) { + /* P/Q data pages */ + wq$$ = wp$$ = *(unative_t *)&dptr[z0][d+$$*NSIZE]; + for ( z = z0-1 ; z >= start ; z-- ) { + wd$$ = *(unative_t *)&dptr[z][d+$$*NSIZE]; + wp$$ ^= wd$$; + w2$$ = MASK(wq$$); + w1$$ = SHLBYTE(wq$$); + w2$$ &= NBYTES(0x1d); + w1$$ ^= w2$$; + wq$$ = w1$$ ^ wd$$; + } + /* P/Q left side optimization */ + for ( z = start-1 ; z >= 0 ; z-- ) { + w2$$ = MASK(wq$$); + w1$$ = SHLBYTE(wq$$); + w2$$ &= NBYTES(0x1d); + wq$$ = w1$$ ^ w2$$; + } + *(unative_t *)&p[d+NSIZE*$$] ^= wp$$; + *(unative_t *)&q[d+NSIZE*$$] ^= wq$$; + } + +} + +const struct raid6_calls raid6_intx$# = { + raid6_int$#_gen_syndrome, + raid6_int$#_xor_syndrome, + NULL, /* always valid */ + "int" NSTRING "x$#", + 0 +}; + +#endif |