| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* -*- linux-c -*- ------------------------------------------------------- * |
| 2 | * |
| 3 | * Copyright 2002-2004 H. Peter Anvin - All Rights Reserved |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License as published by |
| 7 | * the Free Software Foundation, Inc., 53 Temple Place Ste 330, |
| 8 | * Bostom MA 02111-1307, USA; either version 2 of the License, or |
| 9 | * (at your option) any later version; incorporated herein by reference. |
| 10 | * |
| 11 | * ----------------------------------------------------------------------- */ |
| 12 | |
| 13 | /* |
| 14 | * raid6int$#.c |
| 15 | * |
| 16 | * $#-way unrolled portable integer math RAID-6 instruction set |
| 17 | * |
| 18 | * This file is postprocessed using unroll.pl |
| 19 | */ |
| 20 | |
| 21 | #include "raid6.h" |
| 22 | |
| 23 | /* |
| 24 | * This is the C data type to use |
| 25 | */ |
| 26 | |
| 27 | /* Change this from BITS_PER_LONG if there is something better... */ |
| 28 | #if BITS_PER_LONG == 64 |
| 29 | # define NBYTES(x) ((x) * 0x0101010101010101UL) |
| 30 | # define NSIZE 8 |
| 31 | # define NSHIFT 3 |
| 32 | # define NSTRING "64" |
| 33 | typedef u64 unative_t; |
| 34 | #else |
| 35 | # define NBYTES(x) ((x) * 0x01010101U) |
| 36 | # define NSIZE 4 |
| 37 | # define NSHIFT 2 |
| 38 | # define NSTRING "32" |
| 39 | typedef u32 unative_t; |
| 40 | #endif |
| 41 | |
| 42 | |
| 43 | |
| 44 | /* |
| 45 | * IA-64 wants insane amounts of unrolling. On other architectures that |
| 46 | * is just a waste of space. |
| 47 | */ |
| 48 | #if ($# <= 8) || defined(__ia64__) |
| 49 | |
| 50 | |
| 51 | /* |
| 52 | * These sub-operations are separate inlines since they can sometimes be |
| 53 | * specially optimized using architecture-specific hacks. |
| 54 | */ |
| 55 | |
| 56 | /* |
| 57 | * The SHLBYTE() operation shifts each byte left by 1, *not* |
| 58 | * rolling over into the next byte |
| 59 | */ |
| 60 | static inline __attribute_const__ unative_t SHLBYTE(unative_t v) |
| 61 | { |
| 62 | unative_t vv; |
| 63 | |
| 64 | vv = (v << 1) & NBYTES(0xfe); |
| 65 | return vv; |
| 66 | } |
| 67 | |
| 68 | /* |
| 69 | * The MASK() operation returns 0xFF in any byte for which the high |
| 70 | * bit is 1, 0x00 for any byte for which the high bit is 0. |
| 71 | */ |
| 72 | static inline __attribute_const__ unative_t MASK(unative_t v) |
| 73 | { |
| 74 | unative_t vv; |
| 75 | |
| 76 | vv = v & NBYTES(0x80); |
| 77 | vv = (vv << 1) - (vv >> 7); /* Overflow on the top bit is OK */ |
| 78 | return vv; |
| 79 | } |
| 80 | |
| 81 | |
| 82 | static void raid6_int$#_gen_syndrome(int disks, size_t bytes, void **ptrs) |
| 83 | { |
| 84 | u8 **dptr = (u8 **)ptrs; |
| 85 | u8 *p, *q; |
| 86 | int d, z, z0; |
| 87 | |
| 88 | unative_t wd$$, wq$$, wp$$, w1$$, w2$$; |
| 89 | |
| 90 | z0 = disks - 3; /* Highest data disk */ |
| 91 | p = dptr[z0+1]; /* XOR parity */ |
| 92 | q = dptr[z0+2]; /* RS syndrome */ |
| 93 | |
| 94 | for ( d = 0 ; d < bytes ; d += NSIZE*$# ) { |
| 95 | wq$$ = wp$$ = *(unative_t *)&dptr[z0][d+$$*NSIZE]; |
| 96 | for ( z = z0-1 ; z >= 0 ; z-- ) { |
| 97 | wd$$ = *(unative_t *)&dptr[z][d+$$*NSIZE]; |
| 98 | wp$$ ^= wd$$; |
| 99 | w2$$ = MASK(wq$$); |
| 100 | w1$$ = SHLBYTE(wq$$); |
| 101 | w2$$ &= NBYTES(0x1d); |
| 102 | w1$$ ^= w2$$; |
| 103 | wq$$ = w1$$ ^ wd$$; |
| 104 | } |
| 105 | *(unative_t *)&p[d+NSIZE*$$] = wp$$; |
| 106 | *(unative_t *)&q[d+NSIZE*$$] = wq$$; |
| 107 | } |
| 108 | } |
| 109 | |
| 110 | const struct raid6_calls raid6_intx$# = { |
| 111 | raid6_int$#_gen_syndrome, |
| 112 | NULL, /* always valid */ |
| 113 | "int" NSTRING "x$#", |
| 114 | 0 |
| 115 | }; |
| 116 | |
| 117 | #endif |