1/*-
2 * Parts Copyright (c) 1995 Terrence R. Lambert
3 * Copyright (c) 1995 Julian R. Elischer
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 * must display the following acknowledgement:
16 * This product includes software developed by Terrence R. Lambert.
17 * 4. The name Terrence R. Lambert may not be used to endorse or promote
18 * products derived from this software without specific prior written
19 * permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY Julian R. Elischer ``AS IS'' AND ANY
22 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE TERRENCE R. LAMBERT BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * $Id: kern_conf.c,v 1.35 1999/05/09 08:18:12 phk Exp $
34 */
35
36#include <sys/param.h>
37#include <sys/systm.h>
38#include <sys/module.h>
39#include <sys/conf.h>
40#include <sys/vnode.h>
41
42#define NUMCDEV 256
43#define cdevsw_ALLOCSTART (NUMCDEV/2)
44
45struct cdevsw *cdevsw[NUMCDEV];
46int nchrdev = NUMCDEV;
47
48int bmaj2cmaj[NUMCDEV];
49int nblkdev = NUMCDEV;
50
51/*
52 * Routine to convert from character to block device number.
53 *
54 * A minimal stub routine can always return NODEV.
55 */
56dev_t
57chrtoblk(dev_t dev)
58{
59 struct cdevsw *cd;
60
61 if((cd = devsw(dev)) != NULL) {
62 if (cd->d_bmaj != -1)
63 return(makedev(cd->d_bmaj,minor(dev)));
64 }
65 return(NODEV);
66}
67
68int
69cdevsw_add(dev_t *descrip,
70 struct cdevsw *newentry,
71 struct cdevsw **oldentry)
72{
73 int i ;
74
75 if ( *descrip == NODEV) { /* auto (0 is valid) */
76 /*
77 * Search the table looking for a slot...
78 */
79 for (i = cdevsw_ALLOCSTART; i < nchrdev; i++)
80 if (cdevsw[i] == NULL)
81 break; /* found one! */
82 /* out of allocable slots? */
83 if (i >= nchrdev) {
84 return ENFILE;
85 }
86 } else { /* assign */
87 i = major(*descrip);
88 if (i < 0 || i >= nchrdev) {
89 return EINVAL;
90 }
91 }
92
93 /* maybe save old */
94 if (oldentry) {
95 *oldentry = cdevsw[i];
96 }
97 if (newentry) {
98 newentry->d_bmaj = -1;
99 newentry->d_maj = i;
100 }
101 /* replace with new */
102 cdevsw[i] = newentry;
103
104 /* done! let them know where we put it */
105 *descrip = makedev(i,0);
106 return 0;
107}
108
109void
110cdevsw_add_generic(int bmaj, int cmaj, struct cdevsw *devsw)
111{
112 dev_t dev;
113
114 dev = makedev(cmaj, 0);
115 cdevsw_add(&dev, devsw, NULL);
116 cdevsw[cmaj]->d_bmaj = bmaj;
117 bmaj2cmaj[bmaj] = cmaj;
118}
119
120int
121devsw_module_handler(module_t mod, int what, void* arg)
122{
123 struct devsw_module_data* data = (struct devsw_module_data*) arg;
124 int error;
125
126 if (data->cmaj == NOMAJ)
127 data->cdev = NODEV;
128 else
129 data->cdev = makedev(data->cmaj, 0);
130 switch (what) {
131 case MOD_LOAD:
132 error = cdevsw_add(&data->cdev, data->cdevsw, NULL);
133 if (!error && data->cdevsw->d_strategy != nostrategy) {
134 if (data->bmaj == NOMAJ) {
135 data->bdev = data->cdev;
136 data->bmaj = data->cmaj;
137 } else {
138 data->bdev = makedev(data->bmaj, 0);
139 }
140 data->cdevsw->d_maj = data->bmaj;
141 bmaj2cmaj[major(data->bdev)] = major(data->cdev);
142 }
143 if (!error && data->chainevh)
144 error = data->chainevh(mod, what, data->chainarg);
145 return error;
146
147 case MOD_UNLOAD:
148 if (data->chainevh) {
149 error = data->chainevh(mod, what, data->chainarg);
150 if (error)
151 return error;
152 }
153 if (data->cdevsw->d_strategy != nostrategy)
154 bmaj2cmaj[major(data->bdev)] = 0;
155 error = cdevsw_add(&data->cdev, NULL, NULL);
156 return error;
157 }
158
159 if (data->chainevh)
160 return data->chainevh(mod, what, data->chainarg);
161 else
162 return 0;
163}