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
36 #include <sys/param.h>
37 #include <sys/kernel.h>
38 #include <sys/systm.h>
40 #include <sys/mutex.h>
41 #include <sys/sysctl.h>
42 #include <sys/module.h>
43 #include <sys/malloc.h>
45 #include <sys/vnode.h>
46 #include <sys/queue.h>
47 #include <sys/ctype.h>
48 #include <machine/stdarg.h>
50 #define cdevsw_ALLOCSTART (NUMCDEVSW/2)
52 static struct cdevsw *cdevsw[NUMCDEVSW];
54 static MALLOC_DEFINE(M_DEVT, "dev_t", "dev_t storage");
57 * This is the number of hash-buckets. Experiements with 'real-life'
58 * udev_t's show that a prime halfway between two powers of two works
63 /* The number of dev_t's we can create before malloc(9) kick in. */
66 static struct specinfo devt_stash[DEVT_STASH];
68 static LIST_HEAD(, specinfo) dev_hash[DEVT_HASH];
70 static LIST_HEAD(, specinfo) dev_free;
72 devfs_create_t *devfs_create_hook;
73 devfs_destroy_t *devfs_destroy_hook;
76 static int ready_for_devs;
79 SYSCTL_INT(_debug, OID_AUTO, free_devt, CTLFLAG_RW, &free_devt, 0, "");
81 /* XXX: This is a hack */
82 void disk_dev_synth(dev_t dev);
88 return (dev->si_devsw);
89 /* XXX: Hack around our backwards disk code */
92 return (dev->si_devsw);
95 return(cdevsw[major(dev)]);
103 cdevsw_add(struct cdevsw *newentry)
106 if (newentry->d_maj < 0 || newentry->d_maj >= NUMCDEVSW) {
107 printf("%s: ERROR: driver has bogus cdevsw->d_maj = %d\n",
108 newentry->d_name, newentry->d_maj);
112 if (cdevsw[newentry->d_maj]) {
113 printf("WARNING: \"%s\" is usurping \"%s\"'s cdevsw[]\n",
114 newentry->d_name, cdevsw[newentry->d_maj]->d_name);
117 cdevsw[newentry->d_maj] = newentry;
123 * Remove a cdevsw entry
127 cdevsw_remove(struct cdevsw *oldentry)
129 if (oldentry->d_maj < 0 || oldentry->d_maj >= NUMCDEVSW) {
130 printf("%s: ERROR: driver has bogus cdevsw->d_maj = %d\n",
131 oldentry->d_name, oldentry->d_maj);
135 cdevsw[oldentry->d_maj] = NULL;
141 * dev_t and u_dev_t primitives
149 return((x->si_udev >> 8) & 0xff);
157 return(x->si_udev & 0xffff00ff);
168 return ((i & 0xff) | (i >> 8));
175 KASSERT(unit <= 0xffffff, ("Invalid unit (%d) in unit2minor", unit));
176 return ((unit & 0xff) | ((unit << 8) & ~0xffff));
185 if (stashed >= DEVT_STASH) {
186 MALLOC(si, struct specinfo *, sizeof(*si), M_DEVT,
187 M_USE_RESERVE | M_ZERO);
188 } else if (LIST_FIRST(&dev_free)) {
189 si = LIST_FIRST(&dev_free);
190 LIST_REMOVE(si, si_hash);
192 si = devt_stash + stashed++;
193 bzero(si, sizeof *si);
194 si->si_flags |= SI_STASHED;
196 LIST_INIT(&si->si_children);
197 TAILQ_INIT(&si->si_snapshots);
202 makedev(int x, int y)
208 if (x == umajor(NOUDEV) && y == uminor(NOUDEV))
209 panic("makedev of NOUDEV");
211 hash = udev % DEVT_HASH;
212 LIST_FOREACH(si, &dev_hash[hash], si_hash) {
213 if (si->si_udev == udev)
218 LIST_INSERT_HEAD(&dev_hash[hash], si, si_hash);
228 if (SLIST_FIRST(&dev->si_hlist))
230 if (dev->si_devsw || dev->si_drv1 || dev->si_drv2)
232 LIST_REMOVE(dev, si_hash);
233 if (dev->si_flags & SI_STASHED) {
234 bzero(dev, sizeof(*dev));
235 dev->si_flags |= SI_STASHED;
236 LIST_INSERT_HEAD(&dev_free, dev, si_hash);
251 udev2dev(udev_t x, int b)
258 return makedev(umajor(x), uminor(x));
262 Debugger("udev2dev(...,X)");
270 return(dev & 0xffff00ff);
276 return((dev & 0xff00) >> 8);
280 makeudev(int x, int y)
282 return ((x << 8) | y);
286 make_dev(struct cdevsw *devsw, int minor, uid_t uid, gid_t gid, int perms, const char *fmt, ...)
292 KASSERT(umajor(makeudev(devsw->d_maj, minor)) == devsw->d_maj,
293 ("Invalid minor (%d) in make_dev", minor));
295 if (!ready_for_devs) {
296 printf("WARNING: Driver mistake: make_dev(%s) called before SI_SUB_DRIVERS\n",
298 /* XXX panic here once drivers are cleaned up */
301 dev = makedev(devsw->d_maj, minor);
302 if (dev->si_flags & SI_NAMED) {
303 printf( "WARNING: Driver mistake: repeat make_dev(\"%s\")\n",
305 panic("don't do that");
309 i = kvprintf(fmt, NULL, dev->si_name, 32, ap);
310 dev->si_name[i] = '\0';
312 dev->si_devsw = devsw;
315 dev->si_mode = perms;
316 dev->si_flags |= SI_NAMED;
318 if (devfs_create_hook)
319 devfs_create_hook(dev);
324 dev_named(dev_t pdev, const char *name)
328 if (strcmp(devtoname(pdev), name) == 0)
330 LIST_FOREACH(cdev, &pdev->si_children, si_siblings)
331 if (strcmp(devtoname(cdev), name) == 0)
337 dev_depends(dev_t pdev, dev_t cdev)
340 cdev->si_parent = pdev;
341 cdev->si_flags |= SI_CHILD;
342 LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings);
346 make_dev_alias(dev_t pdev, const char *fmt, ...)
353 dev->si_flags |= SI_ALIAS;
354 dev->si_flags |= SI_NAMED;
355 dev_depends(pdev, dev);
357 i = kvprintf(fmt, NULL, dev->si_name, 32, ap);
358 dev->si_name[i] = '\0';
361 if (devfs_create_hook)
362 devfs_create_hook(dev);
367 revoke_and_destroy_dev(dev_t dev)
373 vp = SLIST_FIRST(&dev->si_hlist);
375 VOP_REVOKE(vp, REVOKEALL);
380 destroy_dev(dev_t dev)
383 if (!(dev->si_flags & SI_NAMED)) {
384 printf( "WARNING: Driver mistake: destroy_dev on %d/%d\n",
385 major(dev), minor(dev));
386 panic("don't do that");
390 if (devfs_destroy_hook)
391 devfs_destroy_hook(dev);
392 if (dev->si_flags & SI_CHILD) {
393 LIST_REMOVE(dev, si_siblings);
394 dev->si_flags &= ~SI_CHILD;
396 while (!LIST_EMPTY(&dev->si_children))
397 destroy_dev(LIST_FIRST(&dev->si_children));
401 dev->si_flags &= ~SI_NAMED;
402 dev->si_flags &= ~SI_ALIAS;
412 if (dev->si_name[0] == '#' || dev->si_name[0] == '\0') {
415 sprintf(p, "#%s/", devsw(dev)->d_name);
417 sprintf(p, "#%d/", major(dev));
420 if (mynor < 0 || mynor > 255)
421 sprintf(p, "%#x", (u_int)mynor);
423 sprintf(p, "%d", mynor);
425 return (dev->si_name);
429 dev_stdclone(char *name, char **namep, const char *stem, int *unit)
434 if (bcmp(stem, name, i) != 0)
436 if (!isdigit(name[i]))
439 if (name[i] == '0' && isdigit(name[i+1]))
441 while (isdigit(name[i])) {
443 u += name[i++] - '0';
454 * Helper sysctl for devname(3). We're given a {u}dev_t and return
455 * the name, if any, registered by the device driver.
458 sysctl_devname(SYSCTL_HANDLER_ARGS)
464 error = SYSCTL_IN(req, &ud, sizeof (ud));
469 dev = makedev(umajor(ud), uminor(ud));
470 if (dev->si_name[0] == '\0')
473 error = SYSCTL_OUT(req, dev->si_name, strlen(dev->si_name) + 1);
478 SYSCTL_PROC(_kern, OID_AUTO, devname, CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_ANYBODY,
479 NULL, 0, sysctl_devname, "", "devname(3) handler");
482 * Set ready_for_devs; prior to this point, device creation is not allowed.
485 dev_set_ready(void *junk)
490 SYSINIT(dev_ready, SI_SUB_DEVFS, SI_ORDER_FIRST, dev_set_ready, NULL);