xref: /freebsd/sys/ufs/ffs/ffs_tables.c (revision 19fae0f66023a97a9b464b3beeeabb2081f575b3)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
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 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36 
37 #include <sys/param.h>
38 #include <sys/types.h>
39 #include <ufs/ufs/dinode.h>
40 #include <ufs/ffs/fs.h>
41 
42 /*
43  * Bit patterns for identifying fragments in the block map
44  * used as ((map & around) == inside)
45  */
46 int around[9] = {
47 	0x3, 0x7, 0xf, 0x1f, 0x3f, 0x7f, 0xff, 0x1ff, 0x3ff
48 };
49 int inside[9] = {
50 	0x0, 0x2, 0x6, 0xe, 0x1e, 0x3e, 0x7e, 0xfe, 0x1fe
51 };
52 
53 /*
54  * Given a block map bit pattern, the frag tables tell whether a
55  * particular size fragment is available.
56  *
57  * used as:
58  * if ((1 << (size - 1)) & fragtbl[fs->fs_frag][map] {
59  *	at least one fragment of the indicated size is available
60  * }
61  *
62  * These tables are used by the scanc instruction on the VAX to
63  * quickly find an appropriate fragment.
64  */
65 static uint8_t fragtbl124[256] = {
66 	0x00, 0x16, 0x16, 0x2a, 0x16, 0x16, 0x26, 0x4e,
67 	0x16, 0x16, 0x16, 0x3e, 0x2a, 0x3e, 0x4e, 0x8a,
68 	0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
69 	0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
70 	0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
71 	0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
72 	0x2a, 0x3e, 0x3e, 0x2a, 0x3e, 0x3e, 0x2e, 0x6e,
73 	0x3e, 0x3e, 0x3e, 0x3e, 0x2a, 0x3e, 0x6e, 0xaa,
74 	0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
75 	0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
76 	0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
77 	0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
78 	0x26, 0x36, 0x36, 0x2e, 0x36, 0x36, 0x26, 0x6e,
79 	0x36, 0x36, 0x36, 0x3e, 0x2e, 0x3e, 0x6e, 0xae,
80 	0x4e, 0x5e, 0x5e, 0x6e, 0x5e, 0x5e, 0x6e, 0x4e,
81 	0x5e, 0x5e, 0x5e, 0x7e, 0x6e, 0x7e, 0x4e, 0xce,
82 	0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
83 	0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
84 	0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
85 	0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
86 	0x16, 0x16, 0x16, 0x3e, 0x16, 0x16, 0x36, 0x5e,
87 	0x16, 0x16, 0x16, 0x3e, 0x3e, 0x3e, 0x5e, 0x9e,
88 	0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x7e,
89 	0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x7e, 0xbe,
90 	0x2a, 0x3e, 0x3e, 0x2a, 0x3e, 0x3e, 0x2e, 0x6e,
91 	0x3e, 0x3e, 0x3e, 0x3e, 0x2a, 0x3e, 0x6e, 0xaa,
92 	0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x7e,
93 	0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x7e, 0xbe,
94 	0x4e, 0x5e, 0x5e, 0x6e, 0x5e, 0x5e, 0x6e, 0x4e,
95 	0x5e, 0x5e, 0x5e, 0x7e, 0x6e, 0x7e, 0x4e, 0xce,
96 	0x8a, 0x9e, 0x9e, 0xaa, 0x9e, 0x9e, 0xae, 0xce,
97 	0x9e, 0x9e, 0x9e, 0xbe, 0xaa, 0xbe, 0xce, 0x8a,
98 };
99 
100 static uint8_t fragtbl8[256] = {
101 	0x00, 0x01, 0x01, 0x02, 0x01, 0x01, 0x02, 0x04,
102 	0x01, 0x01, 0x01, 0x03, 0x02, 0x03, 0x04, 0x08,
103 	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
104 	0x02, 0x03, 0x03, 0x02, 0x04, 0x05, 0x08, 0x10,
105 	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
106 	0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,
107 	0x02, 0x03, 0x03, 0x02, 0x03, 0x03, 0x02, 0x06,
108 	0x04, 0x05, 0x05, 0x06, 0x08, 0x09, 0x10, 0x20,
109 	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
110 	0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,
111 	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
112 	0x03, 0x03, 0x03, 0x03, 0x05, 0x05, 0x09, 0x11,
113 	0x02, 0x03, 0x03, 0x02, 0x03, 0x03, 0x02, 0x06,
114 	0x03, 0x03, 0x03, 0x03, 0x02, 0x03, 0x06, 0x0a,
115 	0x04, 0x05, 0x05, 0x06, 0x05, 0x05, 0x06, 0x04,
116 	0x08, 0x09, 0x09, 0x0a, 0x10, 0x11, 0x20, 0x40,
117 	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
118 	0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,
119 	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
120 	0x03, 0x03, 0x03, 0x03, 0x05, 0x05, 0x09, 0x11,
121 	0x01, 0x01, 0x01, 0x03, 0x01, 0x01, 0x03, 0x05,
122 	0x01, 0x01, 0x01, 0x03, 0x03, 0x03, 0x05, 0x09,
123 	0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x07,
124 	0x05, 0x05, 0x05, 0x07, 0x09, 0x09, 0x11, 0x21,
125 	0x02, 0x03, 0x03, 0x02, 0x03, 0x03, 0x02, 0x06,
126 	0x03, 0x03, 0x03, 0x03, 0x02, 0x03, 0x06, 0x0a,
127 	0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x07,
128 	0x02, 0x03, 0x03, 0x02, 0x06, 0x07, 0x0a, 0x12,
129 	0x04, 0x05, 0x05, 0x06, 0x05, 0x05, 0x06, 0x04,
130 	0x05, 0x05, 0x05, 0x07, 0x06, 0x07, 0x04, 0x0c,
131 	0x08, 0x09, 0x09, 0x0a, 0x09, 0x09, 0x0a, 0x0c,
132 	0x10, 0x11, 0x11, 0x12, 0x20, 0x21, 0x40, 0x80,
133 };
134 
135 /*
136  * The actual fragtbl array.
137  */
138 uint8_t *fragtbl[MAXFRAG + 1] = {
139 	0, fragtbl124, fragtbl124, 0, fragtbl124, 0, 0, 0, fragtbl8,
140 };
141