kern_conf.c revision 17675 
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 1.10 1996/07/23 21:52:06 phk Exp $
34 */
35
36#include <sys/param.h>
37#include <sys/types.h>
38#include <sys/systm.h>
39#include <sys/conf.h>
40#include <sys/vnode.h>
41
42#define NUMBDEV 128
43#define NUMCDEV 256
44#define bdevsw_ALLOCSTART	(NUMBDEV/2)
45#define cdevsw_ALLOCSTART	(NUMCDEV/2)
46
47struct bdevsw 	*bdevsw[NUMBDEV];
48int	nblkdev = NUMBDEV;
49struct cdevsw 	*cdevsw[NUMCDEV];
50int	nchrdev = NUMCDEV;
51
52
53
54/*
55 * Routine to determine if a device is a disk.
56 *
57 * KLUDGE XXX add flags to cdevsw entries for disks XXX
58 * A minimal stub routine can always return 0.
59 */
60int
61isdisk(dev, type)
62	dev_t dev;
63	int type;
64{
65
66	switch (major(dev)) {
67	case 15:		/* VBLK: vn, VCHR: cd */
68		return (1);
69	case 0:			/* wd */
70	case 2:			/* fd */
71	case 4:			/* sd */
72	case 6:			/* cd */
73	case 7:			/* mcd */
74	case 16:		/* scd */
75	case 17:		/* matcd */
76	case 18:		/* ata */
77	case 19:		/* wcd */
78	case 20:		/* od */
79		if (type == VBLK)
80			return (1);
81		return (0);
82	case 3:			/* wd */
83	case 9:			/* fd */
84	case 13:		/* sd */
85	case 29:		/* mcd */
86	case 43:		/* vn */
87	case 45:		/* scd */
88	case 46:		/* matcd */
89	case 69:		/* wcd */
90	case 70:		/* od */
91		if (type == VCHR)
92			return (1);
93		/* fall through */
94	default:
95		return (0);
96	}
97	/* NOTREACHED */
98}
99
100
101/*
102 * Routine to convert from character to block device number.
103 *
104 * A minimal stub routine can always return NODEV.
105 */
106dev_t
107chrtoblk(dev_t dev)
108{
109	struct bdevsw *bd;
110	struct cdevsw *cd;
111
112	if(cd = cdevsw[major(dev)]) {
113          if ( (bd = cd->d_bdev) )
114	    return(makedev(bd->d_maj,minor(dev)));
115	}
116	return(NODEV);
117}
118
119/*
120 * (re)place an entry in the bdevsw or cdevsw table
121 * return the slot used in major(*descrip)
122 */
123#define ADDENTRY(TTYPE,NXXXDEV,ALLOCSTART) \
124int TTYPE##_add(dev_t *descrip,						\
125		struct TTYPE *newentry,					\
126		struct TTYPE **oldentry)				\
127{									\
128	int i ;								\
129	if ( (int)*descrip == NODEV) {	/* auto (0 is valid) */		\
130		/*							\
131		 * Search the table looking for a slot...		\
132		 */							\
133		for (i = ALLOCSTART; i < NXXXDEV; i++)				\
134			if (TTYPE[i] == NULL)				\
135				break;		/* found one! */	\
136		/* out of allocable slots? */				\
137		if (i >= NXXXDEV) {					\
138			return ENFILE;					\
139		}							\
140	} else {				/* assign */		\
141		i = major(*descrip);					\
142		if (i < 0 || i >= NXXXDEV) {				\
143			return EINVAL;					\
144		}							\
145	}								\
146									\
147	/* maybe save old */						\
148        if (oldentry) {							\
149		*oldentry = TTYPE[i];					\
150	}								\
151	newentry->d_maj = i;						\
152	/* replace with new */						\
153	TTYPE[i] = newentry;						\
154									\
155	/* done!  let them know where we put it */			\
156	*descrip = makedev(i,0);					\
157	return 0;							\
158} \
159
160ADDENTRY(bdevsw, nblkdev,bdevsw_ALLOCSTART)
161ADDENTRY(cdevsw, nchrdev,cdevsw_ALLOCSTART)
162
163/* Maybe the author might indicate what the f*@# tehis is for? */
164
165void
166cdevsw_make(struct bdevsw *from)
167{
168	struct cdevsw *to = from->d_cdev;
169
170	if (!to)
171		panic("No target cdevsw in bdevsw");
172	to->d_open = from->d_open;
173	to->d_close = from->d_close;
174	to->d_read = rawread;
175	to->d_write = rawwrite;
176	to->d_ioctl = from->d_ioctl;
177	to->d_stop = nostop;
178	to->d_reset = nullreset;
179	to->d_devtotty = nodevtotty;
180	to->d_select = seltrue;
181	to->d_mmap = nommap;
182	to->d_strategy = from->d_strategy;
183	to->d_name = from->d_name;
184	to->d_bdev = from;
185	to->d_maj = -1;
186}
187
188void
189bdevsw_add_generic(int bdev, int cdev, struct bdevsw *bdevsw)
190{
191	dev_t dev;
192	cdevsw_make(bdevsw);
193	dev = makedev(cdev, 0);
194	cdevsw_add(&dev, bdevsw->d_cdev, NULL);
195	dev = makedev(bdev, 0);
196	bdevsw_add(&dev, bdevsw        , NULL);
197}
198