1 /* $OpenBSD: subr_xxx.c,v 1.9 2005/12/09 09:09:52 jsg Exp $ */
2 /* $NetBSD: subr_xxx.c,v 1.10 1996/02/04 02:16:51 christos Exp $ */
3
4 /*
5 * Copyright (c) 1982, 1986, 1991, 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * @(#)subr_xxx.c 8.1 (Berkeley) 6/10/93
33 */
34
35 /*
36 * Miscellaneous trivial functions, including many
37 * that are often inline-expanded or done in assembler.
38 */
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/device.h>
42 #include <sys/conf.h>
43
44 #include <machine/cpu.h>
45
46 /*
47 * Unsupported device function (e.g. writing to read-only device).
48 */
49 int
50 enodev(void)
51 {
52
53 return (ENODEV);
54 }
55
56 /*
57 * Unconfigured device function; driver not configured.
58 */
59 int
60 enxio(void)
61 {
62
63 return (ENXIO);
64 }
65
66 /*
67 * Unsupported ioctl function.
68 */
69 int
70 enoioctl(void)
71 {
72
73 return (ENOTTY);
74 }
75
76 /*
77 * Unsupported system function.
78 * This is used for an otherwise-reasonable operation
79 * that is not supported by the current system binary.
80 */
81 int
82 enosys(void)
83 {
84
85 return (ENOSYS);
86 }
87
88 /*
89 * Return error for operation not supported
90 * on a specific object or file type.
91 */
92 /*ARGSUSED*/
93 int
94 eopnotsupp(void *v)
95 {
96
97 return (EOPNOTSUPP);
98 }
99
100 /*
101 * Generic null operation, always returns success.
102 */
103 /*ARGSUSED*/
104 int
105 nullop(void *v)
106 {
107
108 return (0);
109 }
110
111 struct bdevsw *
112 bdevsw_lookup(dev_t dev)
113 {
114 return (&bdevsw[major(dev)]);
115 }
116
117 struct cdevsw *
118 cdevsw_lookup(dev_t dev)
119 {
120 return (&cdevsw[major(dev)]);
121 }
122
123 /*
124 * Convert a character device number to a block device number.
125 */
126 dev_t
127 chrtoblk(dev_t dev)
128 {
129 int blkmaj;
130
131 if (major(dev) >= nchrdev || major(dev) >= nchrtoblktbl)
132 return (NODEV);
133 blkmaj = chrtoblktbl[major(dev)];
134 if (blkmaj == NODEV)
135 return (NODEV);
136 return (makedev(blkmaj, minor(dev)));
137 }
138
139 /*
140 * Convert a block device number to a character device number.
141 */
142 dev_t
143 blktochr(dev_t dev)
144 {
145 int blkmaj = major(dev);
146 int i;
147
148 if (blkmaj >= nblkdev)
149 return (NODEV);
150 for (i = 0; i < nchrtoblktbl; i++)
151 if (blkmaj == chrtoblktbl[i])
152 return (makedev(i, minor(dev)));
153 return (NODEV);
154 }