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