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
This page was automatically generated by the
LXR engine.
Visit the LXR main site for more
information.