1/* $NetBSD: ffs_tables.c,v 1.9 2005/12/11 12:25:25 christos Exp $ */
2
3/*
4 * Copyright (c) 1982, 1986, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 * @(#)ffs_tables.c 8.1 (Berkeley) 6/11/93
32 */
33
34#if HAVE_NBTOOL_CONFIG_H
35#include "nbtool_config.h"
36#endif
37
38#include <sys/cdefs.h>
39__KERNEL_RCSID(0, "$NetBSD: ffs_tables.c,v 1.9 2005/12/11 12:25:25 christos Exp $");
40
41#include <sys/param.h>
42
43/*
44 * Bit patterns for identifying fragments in the block map
45 * used as ((map & around) == inside)
46 */
47const int around[9] = {
48 0x3, 0x7, 0xf, 0x1f, 0x3f, 0x7f, 0xff, 0x1ff, 0x3ff
49};
50const int inside[9] = {
51 0x0, 0x2, 0x6, 0xe, 0x1e, 0x3e, 0x7e, 0xfe, 0x1fe
52};
53
54/*
55 * Given a block map bit pattern, the frag tables tell whether a
56 * particular size fragment is available.
57 *
58 * used as:
59 * if ((1 << (size - 1)) & fragtbl[fs->fs_frag][map] {
60 * at least one fragment of the indicated size is available
61 * }
62 *
63 * These tables are used by the scanc instruction on the VAX to
64 * quickly find an appropriate fragment.
65 */
66const u_char fragtbl124[256] = {
67 0x00, 0x16, 0x16, 0x2a, 0x16, 0x16, 0x26, 0x4e,
68 0x16, 0x16, 0x16, 0x3e, 0x2a, 0x3e, 0x4e, 0x8a,
69 0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
70 0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
71 0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
72 0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
73 0x2a, 0x3e, 0x3e, 0x2a, 0x3e, 0x3e, 0x2e, 0x6e,
74 0x3e, 0x3e, 0x3e, 0x3e, 0x2a, 0x3e, 0x6e, 0xaa,
75 0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
76 0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
77 0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
78 0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
79 0x26, 0x36, 0x36, 0x2e, 0x36, 0x36, 0x26, 0x6e,
80 0x36, 0x36, 0x36, 0x3e, 0x2e, 0x3e, 0x6e, 0xae,
81 0x4e, 0x5e, 0x5e, 0x6e, 0x5e, 0x5e, 0x6e, 0x4e,
82 0x5e, 0x5e, 0x5e, 0x7e, 0x6e, 0x7e, 0x4e, 0xce,
83 0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
84 0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
85 0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
86 0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
87 0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
88 0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
89 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x7e,
90 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x7e, 0xbe,
91 0x2a, 0x3e, 0x3e, 0x2a, 0x3e, 0x3e, 0x2e, 0x6e,
92 0x3e, 0x3e, 0x3e, 0x3e, 0x2a, 0x3e, 0x6e, 0xaa,
93 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x7e,
94 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x7e, 0xbe,
95 0x4e, 0x5e, 0x5e, 0x6e, 0x5e, 0x5e, 0x6e, 0x4e,
96 0x5e, 0x5e, 0x5e, 0x7e, 0x6e, 0x7e, 0x4e, 0xce,
97 0x8a, 0x9e, 0x9e, 0xaa, 0x9e, 0x9e, 0xae, 0xce,
98 0x9e, 0x9e, 0x9e, 0xbe, 0xaa, 0xbe, 0xce, 0x8a,
99};
100
101const u_char fragtbl8[256] = {
102 0x00, 0x01, 0x01, 0x02, 0x01, 0x01, 0x02, 0x04,
103 0x01, 0x01, 0x01, 0x03, 0x02, 0x03, 0x04, 0x08,
104 0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
105 0x02, 0x03, 0x03, 0x02, 0x04, 0x05, 0x08, 0x10,
106 0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
107 0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,
108 0x02, 0x03, 0x03, 0x02, 0x03, 0x03, 0x02, 0x06,
109 0x04, 0x05, 0x05, 0x06, 0x08, 0x09, 0x10, 0x20,
110 0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
111 0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,
112 0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
113 0x03, 0x03, 0x03, 0x03, 0x05, 0x05, 0x09, 0x11,
114 0x02, 0x03, 0x03, 0x02, 0x03, 0x03, 0x02, 0x06,
115 0x03, 0x03, 0x03, 0x03, 0x02, 0x03, 0x06, 0x0a,
116 0x04, 0x05, 0x05, 0x06, 0x05, 0x05, 0x06, 0x04,
117 0x08, 0x09, 0x09, 0x0a, 0x10, 0x11, 0x20, 0x40,
118 0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
119 0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,
120 0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
121 0x03, 0x03, 0x03, 0x03, 0x05, 0x05, 0x09, 0x11,
122 0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
123 0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,
124 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x07,
125 0x05, 0x05, 0x05, 0x07, 0x09, 0x09, 0x11, 0x21,
126 0x02, 0x03, 0x03, 0x02, 0x03, 0x03, 0x02, 0x06,
127 0x03, 0x03, 0x03, 0x03, 0x02, 0x03, 0x06, 0x0a,
128 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x07,
129 0x02, 0x03, 0x03, 0x02, 0x06, 0x07, 0x0a, 0x12,
130 0x04, 0x05, 0x05, 0x06, 0x05, 0x05, 0x06, 0x04,
131 0x05, 0x05, 0x05, 0x07, 0x06, 0x07, 0x04, 0x0c,
132 0x08, 0x09, 0x09, 0x0a, 0x09, 0x09, 0x0a, 0x0c,
133 0x10, 0x11, 0x11, 0x12, 0x20, 0x21, 0x40, 0x80,
134};
135
136/*
137 * The actual fragtbl array.
138 */
139const u_char * const fragtbl[MAXFRAG + 1] = {
140 0, fragtbl124, fragtbl124, 0, fragtbl124, 0, 0, 0, fragtbl8,
141};
142