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 | */ |
47 | const int around[9] = { |
48 | 0x3, 0x7, 0xf, 0x1f, 0x3f, 0x7f, 0xff, 0x1ff, 0x3ff |
49 | }; |
50 | const 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 | */ |
66 | const 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 | |
101 | const 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 | */ |
139 | const u_char * const fragtbl[MAXFRAG + 1] = { |
140 | 0, fragtbl124, fragtbl124, 0, fragtbl124, 0, 0, 0, fragtbl8, |
141 | }; |
142 | |