2 * Parts Copyright (c) 1995 Terrence R. Lambert
3 * Copyright (c) 1995 Julian R. Elischer
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
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
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
33 * $FreeBSD: src/sys/kern/kern_conf.c,v 1.73.2.3 2003/03/10 02:18:25 imp Exp $
34 * $DragonFly: src/sys/kern/kern_conf.c,v 1.3 2003/07/21 05:50:43 dillon Exp $
37 #include <sys/param.h>
38 #include <sys/kernel.h>
39 #include <sys/sysctl.h>
40 #include <sys/systm.h>
41 #include <sys/module.h>
42 #include <sys/malloc.h>
44 #include <sys/vnode.h>
45 #include <sys/queue.h>
46 #include <machine/stdarg.h>
48 #define cdevsw_ALLOCSTART (NUMCDEVSW/2)
50 static struct cdevsw *cdevsw[NUMCDEVSW];
52 MALLOC_DEFINE(M_DEVT, "dev_t", "dev_t storage");
55 * This is the number of hash-buckets. Experiements with 'real-life'
56 * udev_t's show that a prime halfway between two powers of two works
61 /* The number of dev_t's we can create before malloc(9) kick in. */
64 static struct specinfo devt_stash[DEVT_STASH];
66 static LIST_HEAD(, specinfo) dev_hash[DEVT_HASH];
68 static LIST_HEAD(, specinfo) dev_free;
71 SYSCTL_INT(_debug, OID_AUTO, free_devt, CTLFLAG_RW, &free_devt, 0, "");
77 return (dev->si_devsw);
78 return(cdevsw[major(dev)]);
82 compile_devsw(struct cdevsw *devsw)
84 static lwkt_port devsw_compat_port;
86 /* YYY init devsw_compat_port */
88 if (devsw->d_open == NULL)
89 devsw->d_open = noopen;
90 if (devsw->d_close == NULL)
91 devsw->d_close = noclose;
92 if (devsw->d_read == NULL)
93 devsw->d_read = noread;
94 if (devsw->d_write == NULL)
95 devsw->d_write = nowrite;
96 if (devsw->d_ioctl == NULL)
97 devsw->d_ioctl = noioctl;
98 if (devsw->d_poll == NULL)
99 devsw->d_poll = nopoll;
100 if (devsw->d_mmap == NULL)
101 devsw->d_mmap = nommap;
102 if (devsw->d_strategy == NULL)
103 devsw->d_strategy = nostrategy;
104 if (devsw->d_dump == NULL)
105 devsw->d_dump = nodump;
106 if (devsw->d_psize == NULL)
107 devsw->d_psize = nopsize;
108 if (devsw->d_kqfilter == NULL)
109 devsw->d_kqfilter = nokqfilter;
110 if (devsw->d_port == NULL)
111 devsw->d_port = &devsw_compat_port;
119 cdevsw_add(struct cdevsw *newentry)
121 compile_devsw(newentry);
122 if (newentry->d_maj < 0 || newentry->d_maj >= NUMCDEVSW) {
123 printf("%s: ERROR: driver has bogus cdevsw->d_maj = %d\n",
124 newentry->d_name, newentry->d_maj);
127 if (cdevsw[newentry->d_maj]) {
128 printf("WARNING: \"%s\" is usurping \"%s\"'s cdevsw[]\n",
129 newentry->d_name, cdevsw[newentry->d_maj]->d_name);
132 cdevsw[newentry->d_maj] = newentry;
137 * Remove a cdevsw entry
141 cdevsw_remove(struct cdevsw *oldentry)
143 if (oldentry->d_maj < 0 || oldentry->d_maj >= NUMCDEVSW) {
144 printf("%s: ERROR: driver has bogus cdevsw->d_maj = %d\n",
145 oldentry->d_name, oldentry->d_maj);
149 cdevsw[oldentry->d_maj] = NULL;
155 * dev_t and u_dev_t primitives
163 return((x->si_udev >> 8) & 0xff);
171 return(x->si_udev & 0xffff00ff);
182 return ((i & 0xff) | (i >> 8));
186 makedev(int x, int y)
193 if (x == umajor(NOUDEV) && y == uminor(NOUDEV))
194 Debugger("makedev of NOUDEV");
196 hash = udev % DEVT_HASH;
197 LIST_FOREACH(si, &dev_hash[hash], si_hash) {
198 if (si->si_udev == udev)
201 if (stashed >= DEVT_STASH) {
202 MALLOC(si, struct specinfo *, sizeof(*si), M_DEVT,
204 bzero(si, sizeof(*si));
205 } else if (LIST_FIRST(&dev_free)) {
206 si = LIST_FIRST(&dev_free);
207 LIST_REMOVE(si, si_hash);
209 si = devt_stash + stashed++;
210 si->si_flags |= SI_STASHED;
213 LIST_INSERT_HEAD(&dev_hash[hash], si, si_hash);
224 if (SLIST_FIRST(&dev->si_hlist))
226 if (dev->si_devsw || dev->si_drv1 || dev->si_drv2)
228 hash = dev->si_udev % DEVT_HASH;
229 LIST_REMOVE(dev, si_hash);
230 if (dev->si_flags & SI_STASHED) {
231 bzero(dev, sizeof(*dev));
232 LIST_INSERT_HEAD(&dev_free, dev, si_hash);
247 udev2dev(udev_t x, int b)
254 return makedev(umajor(x), uminor(x));
256 printf("udev2dev: attempt to lookup block dev(%d)", x);
259 Debugger("udev2dev(...,X)");
267 return(dev & 0xffff00ff);
273 return((dev & 0xff00) >> 8);
277 makeudev(int x, int y)
279 return ((x << 8) | y);
283 make_dev(struct cdevsw *devsw, int minor, uid_t uid, gid_t gid, int perms, const char *fmt, ...)
289 compile_devsw(devsw);
290 dev = makedev(devsw->d_maj, minor);
292 i = kvprintf(fmt, NULL, dev->si_name, 32, ap);
293 dev->si_name[i] = '\0';
295 dev->si_devsw = devsw;
301 destroy_dev(dev_t dev)
315 if (dev->si_name[0] == '#' || dev->si_name[0] == '\0') {
318 sprintf(p, "#%s/", devsw(dev)->d_name);
320 sprintf(p, "#%d/", major(dev));
323 if (mynor < 0 || mynor > 255)
324 sprintf(p, "%#x", (u_int)mynor);
326 sprintf(p, "%d", mynor);
328 return (dev->si_name);