xref: /netbsd-src/sys/kern/subr_autoconf.c (revision 4472dbe5e3bd91ef2540bada7a7ca7384627ff9b)
1 /* $NetBSD: subr_autoconf.c,v 1.53 2000/06/04 19:15:19 cgd Exp $ */
2 
3 /*
4  * Copyright (c) 1996, 2000 Christopher G. Demetriou
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *      This product includes software developed by Christopher G. Demetriou
18  *      for the NetBSD Project.
19  * 4. The name of the author may not be used to endorse or promote products
20  *    derived from this software without specific prior written permission
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 /*
35  * Copyright (c) 1992, 1993
36  *	The Regents of the University of California.  All rights reserved.
37  *
38  * This software was developed by the Computer Systems Engineering group
39  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
40  * contributed to Berkeley.
41  *
42  * All advertising materials mentioning features or use of this software
43  * must display the following acknowledgement:
44  *	This product includes software developed by the University of
45  *	California, Lawrence Berkeley Laboratories.
46  *
47  * Redistribution and use in source and binary forms, with or without
48  * modification, are permitted provided that the following conditions
49  * are met:
50  * 1. Redistributions of source code must retain the above copyright
51  *    notice, this list of conditions and the following disclaimer.
52  * 2. Redistributions in binary form must reproduce the above copyright
53  *    notice, this list of conditions and the following disclaimer in the
54  *    documentation and/or other materials provided with the distribution.
55  * 3. All advertising materials mentioning features or use of this software
56  *    must display the following acknowledgement:
57  *	This product includes software developed by the University of
58  *	California, Berkeley and its contributors.
59  * 4. Neither the name of the University nor the names of its contributors
60  *    may be used to endorse or promote products derived from this software
61  *    without specific prior written permission.
62  *
63  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
64  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
65  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
66  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
67  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
68  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
69  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
70  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
71  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
72  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
73  * SUCH DAMAGE.
74  *
75  * from: Header: subr_autoconf.c,v 1.12 93/02/01 19:31:48 torek Exp  (LBL)
76  *
77  *	@(#)subr_autoconf.c	8.3 (Berkeley) 5/17/94
78  */
79 
80 #include <sys/cdefs.h>
81 
82 __KERNEL_RCSID(0, "$NetBSD: subr_autoconf.c,v 1.53 2000/06/04 19:15:19 cgd Exp $");
83 
84 #include <sys/param.h>
85 #include <sys/device.h>
86 #include <sys/malloc.h>
87 #include <sys/systm.h>
88 #include <sys/kernel.h>
89 #include <sys/errno.h>
90 #include <sys/proc.h>
91 #include <machine/limits.h>
92 
93 /*
94  * Autoconfiguration subroutines.
95  */
96 
97 /*
98  * ioconf.c exports exactly two names: cfdata and cfroots.  All system
99  * devices and drivers are found via these tables.
100  */
101 extern struct cfdata cfdata[];
102 extern short cfroots[];
103 
104 #define	ROOT ((struct device *)NULL)
105 
106 struct matchinfo {
107 	cfmatch_t fn;
108 	struct	device *parent;
109 	void	*aux;
110 	struct	cfdata *match;
111 	int	pri;
112 };
113 
114 static char *number(char *, int);
115 static void mapply(struct matchinfo *, struct cfdata *);
116 
117 struct deferred_config {
118 	TAILQ_ENTRY(deferred_config) dc_queue;
119 	struct device *dc_dev;
120 	void (*dc_func)(struct device *);
121 };
122 
123 TAILQ_HEAD(deferred_config_head, deferred_config);
124 
125 struct deferred_config_head deferred_config_queue;
126 struct deferred_config_head interrupt_config_queue;
127 
128 static void config_process_deferred(struct deferred_config_head *,
129 	struct device *);
130 
131 struct devicelist alldevs;		/* list of all devices */
132 struct evcntlist allevents;		/* list of all event counters */
133 
134 __volatile int config_pending;		/* semaphore for mountroot */
135 
136 /*
137  * Configure the system's hardware.
138  */
139 void
140 configure(void)
141 {
142 
143 	TAILQ_INIT(&deferred_config_queue);
144 	TAILQ_INIT(&interrupt_config_queue);
145 	TAILQ_INIT(&alldevs);
146 	TAILQ_INIT(&allevents);
147 
148 	/*
149 	 * Do the machine-dependent portion of autoconfiguration.  This
150 	 * sets the configuration machinery here in motion by "finding"
151 	 * the root bus.  When this function returns, we expect interrupts
152 	 * to be enabled.
153 	 */
154 	cpu_configure();
155 
156 	/*
157 	 * Now that we've found all the hardware, start the real time
158 	 * and statistics clocks.
159 	 */
160 	initclocks();
161 
162 	cold = 0;	/* clocks are running, we're warm now! */
163 
164 	/*
165 	 * Now callback to finish configuration for devices which want
166 	 * to do this once interrupts are enabled.
167 	 */
168 	config_process_deferred(&interrupt_config_queue, NULL);
169 }
170 
171 /*
172  * Apply the matching function and choose the best.  This is used
173  * a few times and we want to keep the code small.
174  */
175 static void
176 mapply(struct matchinfo *m, struct cfdata *cf)
177 {
178 	int pri;
179 
180 	if (m->fn != NULL)
181 		pri = (*m->fn)(m->parent, cf, m->aux);
182 	else {
183 	        if (cf->cf_attach->ca_match == NULL) {
184 			panic("mapply: no match function for '%s' device\n",
185 			    cf->cf_driver->cd_name);
186 		}
187 		pri = (*cf->cf_attach->ca_match)(m->parent, cf, m->aux);
188 	}
189 	if (pri > m->pri) {
190 		m->match = cf;
191 		m->pri = pri;
192 	}
193 }
194 
195 /*
196  * Iterate over all potential children of some device, calling the given
197  * function (default being the child's match function) for each one.
198  * Nonzero returns are matches; the highest value returned is considered
199  * the best match.  Return the `found child' if we got a match, or NULL
200  * otherwise.  The `aux' pointer is simply passed on through.
201  *
202  * Note that this function is designed so that it can be used to apply
203  * an arbitrary function to all potential children (its return value
204  * can be ignored).
205  */
206 struct cfdata *
207 config_search(cfmatch_t fn, struct device *parent, void *aux)
208 {
209 	struct cfdata *cf;
210 	short *p;
211 	struct matchinfo m;
212 
213 	m.fn = fn;
214 	m.parent = parent;
215 	m.aux = aux;
216 	m.match = NULL;
217 	m.pri = 0;
218 	for (cf = cfdata; cf->cf_driver; cf++) {
219 		/*
220 		 * Skip cf if no longer eligible, otherwise scan through
221 		 * parents for one matching `parent', and try match function.
222 		 */
223 		if (cf->cf_fstate == FSTATE_FOUND)
224 			continue;
225 		for (p = cf->cf_parents; *p >= 0; p++)
226 			if (parent->dv_cfdata == &cfdata[*p])
227 				mapply(&m, cf);
228 	}
229 	return (m.match);
230 }
231 
232 /*
233  * Find the given root device.
234  * This is much like config_search, but there is no parent.
235  */
236 struct cfdata *
237 config_rootsearch(cfmatch_t fn, const char *rootname, void *aux)
238 {
239 	struct cfdata *cf;
240 	short *p;
241 	struct matchinfo m;
242 
243 	m.fn = fn;
244 	m.parent = ROOT;
245 	m.aux = aux;
246 	m.match = NULL;
247 	m.pri = 0;
248 	/*
249 	 * Look at root entries for matching name.  We do not bother
250 	 * with found-state here since only one root should ever be
251 	 * searched (and it must be done first).
252 	 */
253 	for (p = cfroots; *p >= 0; p++) {
254 		cf = &cfdata[*p];
255 		if (strcmp(cf->cf_driver->cd_name, rootname) == 0)
256 			mapply(&m, cf);
257 	}
258 	return (m.match);
259 }
260 
261 static const char *msgs[3] = { "", " not configured\n", " unsupported\n" };
262 
263 /*
264  * The given `aux' argument describes a device that has been found
265  * on the given parent, but not necessarily configured.  Locate the
266  * configuration data for that device (using the submatch function
267  * provided, or using candidates' cd_match configuration driver
268  * functions) and attach it, and return true.  If the device was
269  * not configured, call the given `print' function and return 0.
270  */
271 struct device *
272 config_found_sm(struct device *parent, void *aux, cfprint_t print,
273     cfmatch_t submatch)
274 {
275 	struct cfdata *cf;
276 
277 	if ((cf = config_search(submatch, parent, aux)) != NULL)
278 		return (config_attach(parent, cf, aux, print));
279 	if (print)
280 		printf(msgs[(*print)(aux, parent->dv_xname)]);
281 	return (NULL);
282 }
283 
284 /*
285  * As above, but for root devices.
286  */
287 struct device *
288 config_rootfound(const char *rootname, void *aux)
289 {
290 	struct cfdata *cf;
291 
292 	if ((cf = config_rootsearch((cfmatch_t)NULL, rootname, aux)) != NULL)
293 		return (config_attach(ROOT, cf, aux, (cfprint_t)NULL));
294 	printf("root device %s not configured\n", rootname);
295 	return (NULL);
296 }
297 
298 /* just like sprintf(buf, "%d") except that it works from the end */
299 static char *
300 number(char *ep, int n)
301 {
302 
303 	*--ep = 0;
304 	while (n >= 10) {
305 		*--ep = (n % 10) + '0';
306 		n /= 10;
307 	}
308 	*--ep = n + '0';
309 	return (ep);
310 }
311 
312 /*
313  * Attach a found device.  Allocates memory for device variables.
314  */
315 struct device *
316 config_attach(struct device *parent, struct cfdata *cf, void *aux,
317 	cfprint_t print)
318 {
319 	struct device *dev;
320 	struct cfdriver *cd;
321 	struct cfattach *ca;
322 	size_t lname, lunit;
323 	const char *xunit;
324 	int myunit;
325 	char num[10];
326 
327 	cd = cf->cf_driver;
328 	ca = cf->cf_attach;
329 	if (ca->ca_devsize < sizeof(struct device))
330 		panic("config_attach");
331 #ifndef __BROKEN_CONFIG_UNIT_USAGE
332 	if (cf->cf_fstate == FSTATE_STAR) {
333 		for (myunit = cf->cf_unit; myunit < cd->cd_ndevs; myunit++)
334 			if (cd->cd_devs[myunit] == NULL)
335 				break;
336 		/*
337 		 * myunit is now the unit of the first NULL device pointer,
338 		 * or max(cd->cd_ndevs,cf->cf_unit).
339 		 */
340 	} else {
341 		myunit = cf->cf_unit;
342 #else /* __BROKEN_CONFIG_UNIT_USAGE */
343 	myunit = cf->cf_unit;
344 	if (cf->cf_fstate == FSTATE_STAR)
345 		cf->cf_unit++;
346 	else {
347 #endif /* __BROKEN_CONFIG_UNIT_USAGE */
348 		KASSERT(cf->cf_fstate == FSTATE_NOTFOUND);
349 		cf->cf_fstate = FSTATE_FOUND;
350 	}
351 
352 	/* compute length of name and decimal expansion of unit number */
353 	lname = strlen(cd->cd_name);
354 	xunit = number(&num[sizeof(num)], myunit);
355 	lunit = &num[sizeof(num)] - xunit;
356 	if (lname + lunit >= sizeof(dev->dv_xname))
357 		panic("config_attach: device name too long");
358 
359 	/* get memory for all device vars */
360 	dev = (struct device *)malloc(ca->ca_devsize, M_DEVBUF,
361 	    cold ? M_NOWAIT : M_WAITOK);
362 	if (!dev)
363 	    panic("config_attach: memory allocation for device softc failed");
364 	memset(dev, 0, ca->ca_devsize);
365 	TAILQ_INSERT_TAIL(&alldevs, dev, dv_list);	/* link up */
366 	dev->dv_class = cd->cd_class;
367 	dev->dv_cfdata = cf;
368 	dev->dv_unit = myunit;
369 	memcpy(dev->dv_xname, cd->cd_name, lname);
370 	memcpy(dev->dv_xname + lname, xunit, lunit);
371 	dev->dv_parent = parent;
372 	dev->dv_flags = DVF_ACTIVE;	/* always initially active */
373 
374 	if (parent == ROOT)
375 		printf("%s (root)", dev->dv_xname);
376 	else {
377 		printf("%s at %s", dev->dv_xname, parent->dv_xname);
378 		if (print)
379 			(void) (*print)(aux, NULL);
380 	}
381 
382 	/* put this device in the devices array */
383 	if (dev->dv_unit >= cd->cd_ndevs) {
384 		/*
385 		 * Need to expand the array.
386 		 */
387 		int old = cd->cd_ndevs, new;
388 		void **nsp;
389 
390 		if (old == 0)
391 			new = MINALLOCSIZE / sizeof(void *);
392 		else
393 			new = old * 2;
394 		while (new <= dev->dv_unit)
395 			new *= 2;
396 		cd->cd_ndevs = new;
397 		nsp = malloc(new * sizeof(void *), M_DEVBUF,
398 		    cold ? M_NOWAIT : M_WAITOK);
399 		if (nsp == 0)
400 			panic("config_attach: %sing dev array",
401 			    old != 0 ? "expand" : "creat");
402 		memset(nsp + old, 0, (new - old) * sizeof(void *));
403 		if (old != 0) {
404 			memcpy(nsp, cd->cd_devs, old * sizeof(void *));
405 			free(cd->cd_devs, M_DEVBUF);
406 		}
407 		cd->cd_devs = nsp;
408 	}
409 	if (cd->cd_devs[dev->dv_unit])
410 		panic("config_attach: duplicate %s", dev->dv_xname);
411 	cd->cd_devs[dev->dv_unit] = dev;
412 
413 	/*
414 	 * Before attaching, clobber any unfound devices that are
415 	 * otherwise identical.
416 	 */
417 #ifdef __BROKEN_CONFIG_UNIT_USAGE
418 	/* bump the unit number on all starred cfdata for this device. */
419 #endif /* __BROKEN_CONFIG_UNIT_USAGE */
420 	for (cf = cfdata; cf->cf_driver; cf++)
421 		if (cf->cf_driver == cd && cf->cf_unit == dev->dv_unit) {
422 			if (cf->cf_fstate == FSTATE_NOTFOUND)
423 				cf->cf_fstate = FSTATE_FOUND;
424 #ifdef __BROKEN_CONFIG_UNIT_USAGE
425 			if (cf->cf_fstate == FSTATE_STAR)
426 				cf->cf_unit++;
427 #endif /* __BROKEN_CONFIG_UNIT_USAGE */
428 		}
429 #ifdef __HAVE_DEVICE_REGISTER
430 	device_register(dev, aux);
431 #endif
432 	(*ca->ca_attach)(parent, dev, aux);
433 	config_process_deferred(&deferred_config_queue, dev);
434 	return (dev);
435 }
436 
437 /*
438  * Detach a device.  Optionally forced (e.g. because of hardware
439  * removal) and quiet.  Returns zero if successful, non-zero
440  * (an error code) otherwise.
441  *
442  * Note that this code wants to be run from a process context, so
443  * that the detach can sleep to allow processes which have a device
444  * open to run and unwind their stacks.
445  */
446 int
447 config_detach(struct device *dev, int flags)
448 {
449 	struct cfdata *cf;
450 	struct cfattach *ca;
451 	struct cfdriver *cd;
452 #ifdef DIAGNOSTIC
453 	struct device *d;
454 #endif
455 	int rv = 0, i;
456 
457 	cf = dev->dv_cfdata;
458 #ifdef DIAGNOSTIC
459 	if (cf->cf_fstate != FSTATE_FOUND && cf->cf_fstate != FSTATE_STAR)
460 		panic("config_detach: bad device fstate");
461 #endif
462 	ca = cf->cf_attach;
463 	cd = cf->cf_driver;
464 
465 	/*
466 	 * Ensure the device is deactivated.  If the device doesn't
467 	 * have an activation entry point, we allow DVF_ACTIVE to
468 	 * remain set.  Otherwise, if DVF_ACTIVE is still set, the
469 	 * device is busy, and the detach fails.
470 	 */
471 	if (ca->ca_activate != NULL)
472 		rv = config_deactivate(dev);
473 
474 	/*
475 	 * Try to detach the device.  If that's not possible, then
476 	 * we either panic() (for the forced but failed case), or
477 	 * return an error.
478 	 */
479 	if (rv == 0) {
480 		if (ca->ca_detach != NULL)
481 			rv = (*ca->ca_detach)(dev, flags);
482 		else
483 			rv = EOPNOTSUPP;
484 	}
485 	if (rv != 0) {
486 		if ((flags & DETACH_FORCE) == 0)
487 			return (rv);
488 		else
489 			panic("config_detach: forced detach of %s failed (%d)",
490 			    dev->dv_xname, rv);
491 	}
492 
493 	/*
494 	 * The device has now been successfully detached.
495 	 */
496 
497 #ifdef DIAGNOSTIC
498 	/*
499 	 * Sanity: If you're successfully detached, you should have no
500 	 * children.  (Note that because children must be attached
501 	 * after parents, we only need to search the latter part of
502 	 * the list.)
503 	 */
504 	for (d = TAILQ_NEXT(dev, dv_list); d != NULL;
505 	    d = TAILQ_NEXT(d, dv_list)) {
506 		if (d->dv_parent == dev) {
507 			printf("config_detach: detached device %s"
508 			    " has children %s\n", dev->dv_xname, d->dv_xname);
509 			panic("config_detach");
510 		}
511 	}
512 #endif
513 
514 	/*
515 	 * Mark cfdata to show that the unit can be reused, if possible.
516 	 */
517 #ifdef __BROKEN_CONFIG_UNIT_USAGE
518 	/*
519 	 * Note that we can only re-use a starred unit number if the unit
520 	 * being detached had the last assigned unit number.
521 	 */
522 #endif /* __BROKEN_CONFIG_UNIT_USAGE */
523 	for (cf = cfdata; cf->cf_driver; cf++) {
524 		if (cf->cf_driver == cd) {
525 			if (cf->cf_fstate == FSTATE_FOUND &&
526 			    cf->cf_unit == dev->dv_unit)
527 				cf->cf_fstate = FSTATE_NOTFOUND;
528 #ifdef __BROKEN_CONFIG_UNIT_USAGE
529 			if (cf->cf_fstate == FSTATE_STAR &&
530 			    cf->cf_unit == dev->dv_unit + 1)
531 				cf->cf_unit--;
532 #endif /* __BROKEN_CONFIG_UNIT_USAGE */
533 		}
534 	}
535 
536 	/*
537 	 * Unlink from device list.
538 	 */
539 	TAILQ_REMOVE(&alldevs, dev, dv_list);
540 
541 	/*
542 	 * Remove from cfdriver's array, tell the world, and free softc.
543 	 */
544 	cd->cd_devs[dev->dv_unit] = NULL;
545 	if ((flags & DETACH_QUIET) == 0)
546 		printf("%s detached\n", dev->dv_xname);
547 	free(dev, M_DEVBUF);
548 
549 	/*
550 	 * If the device now has no units in use, deallocate its softc array.
551 	 */
552 	for (i = 0; i < cd->cd_ndevs; i++)
553 		if (cd->cd_devs[i] != NULL)
554 			break;
555 	if (i == cd->cd_ndevs) {		/* nothing found; deallocate */
556 		free(cd->cd_devs, M_DEVBUF);
557 		cd->cd_devs = NULL;
558 		cd->cd_ndevs = 0;
559 	}
560 
561 	/*
562 	 * Return success.
563 	 */
564 	return (0);
565 }
566 
567 int
568 config_activate(struct device *dev)
569 {
570 	struct cfattach *ca = dev->dv_cfdata->cf_attach;
571 	int rv = 0, oflags = dev->dv_flags;
572 
573 	if (ca->ca_activate == NULL)
574 		return (EOPNOTSUPP);
575 
576 	if ((dev->dv_flags & DVF_ACTIVE) == 0) {
577 		dev->dv_flags |= DVF_ACTIVE;
578 		rv = (*ca->ca_activate)(dev, DVACT_ACTIVATE);
579 		if (rv)
580 			dev->dv_flags = oflags;
581 	}
582 	return (rv);
583 }
584 
585 int
586 config_deactivate(struct device *dev)
587 {
588 	struct cfattach *ca = dev->dv_cfdata->cf_attach;
589 	int rv = 0, oflags = dev->dv_flags;
590 
591 	if (ca->ca_activate == NULL)
592 		return (EOPNOTSUPP);
593 
594 	if (dev->dv_flags & DVF_ACTIVE) {
595 		dev->dv_flags &= ~DVF_ACTIVE;
596 		rv = (*ca->ca_activate)(dev, DVACT_DEACTIVATE);
597 		if (rv)
598 			dev->dv_flags = oflags;
599 	}
600 	return (rv);
601 }
602 
603 /*
604  * Defer the configuration of the specified device until all
605  * of its parent's devices have been attached.
606  */
607 void
608 config_defer(struct device *dev, void (*func)(struct device *))
609 {
610 	struct deferred_config *dc;
611 
612 	if (dev->dv_parent == NULL)
613 		panic("config_defer: can't defer config of a root device");
614 
615 #ifdef DIAGNOSTIC
616 	for (dc = TAILQ_FIRST(&deferred_config_queue); dc != NULL;
617 	     dc = TAILQ_NEXT(dc, dc_queue)) {
618 		if (dc->dc_dev == dev)
619 			panic("config_defer: deferred twice");
620 	}
621 #endif
622 
623 	dc = malloc(sizeof(*dc), M_DEVBUF, cold ? M_NOWAIT : M_WAITOK);
624 	if (dc == NULL)
625 		panic("config_defer: unable to allocate callback");
626 
627 	dc->dc_dev = dev;
628 	dc->dc_func = func;
629 	TAILQ_INSERT_TAIL(&deferred_config_queue, dc, dc_queue);
630 	config_pending_incr();
631 }
632 
633 /*
634  * Defer some autoconfiguration for a device until after interrupts
635  * are enabled.
636  */
637 void
638 config_interrupts(struct device *dev, void (*func)(struct device *))
639 {
640 	struct deferred_config *dc;
641 
642 	/*
643 	 * If interrupts are enabled, callback now.
644 	 */
645 	if (cold == 0) {
646 		(*func)(dev);
647 		return;
648 	}
649 
650 #ifdef DIAGNOSTIC
651 	for (dc = TAILQ_FIRST(&interrupt_config_queue); dc != NULL;
652 	     dc = TAILQ_NEXT(dc, dc_queue)) {
653 		if (dc->dc_dev == dev)
654 			panic("config_interrupts: deferred twice");
655 	}
656 #endif
657 
658 	dc = malloc(sizeof(*dc), M_DEVBUF, cold ? M_NOWAIT : M_WAITOK);
659 	if (dc == NULL)
660 		panic("config_interrupts: unable to allocate callback");
661 
662 	dc->dc_dev = dev;
663 	dc->dc_func = func;
664 	TAILQ_INSERT_TAIL(&interrupt_config_queue, dc, dc_queue);
665 	config_pending_incr();
666 }
667 
668 /*
669  * Process a deferred configuration queue.
670  */
671 static void
672 config_process_deferred(struct deferred_config_head *queue,
673     struct device *parent)
674 {
675 	struct deferred_config *dc, *ndc;
676 
677 	for (dc = TAILQ_FIRST(queue); dc != NULL; dc = ndc) {
678 		ndc = TAILQ_NEXT(dc, dc_queue);
679 		if (parent == NULL || dc->dc_dev->dv_parent == parent) {
680 			TAILQ_REMOVE(queue, dc, dc_queue);
681 			(*dc->dc_func)(dc->dc_dev);
682 			free(dc, M_DEVBUF);
683 			config_pending_decr();
684 		}
685 	}
686 }
687 
688 /*
689  * Manipulate the config_pending semaphore.
690  */
691 void
692 config_pending_incr(void)
693 {
694 
695 	config_pending++;
696 }
697 
698 void
699 config_pending_decr(void)
700 {
701 
702 #ifdef DIAGNOSTIC
703 	if (config_pending == 0)
704 		panic("config_pending_decr: config_pending == 0");
705 #endif
706 	config_pending--;
707 	if (config_pending == 0)
708 		wakeup((void *)&config_pending);
709 }
710 
711 /*
712  * Attach a statically-initialized event.  The type and string pointers
713  * are already set up.
714  */
715 void
716 evcnt_attach_static(struct evcnt *ev)
717 {
718 	int len;
719 
720 	len = strlen(ev->ev_group);
721 #ifdef DIAGNOSTIC
722 	if (len >= EVCNT_STRING_MAX)		/* ..._MAX includes NUL */
723 		panic("evcnt_attach_static: group length (%s)", ev->ev_group);
724 #endif
725 	ev->ev_grouplen = len;
726 
727 	len = strlen(ev->ev_name);
728 #ifdef DIAGNOSTIC
729 	if (len >= EVCNT_STRING_MAX)		/* ..._MAX includes NUL */
730 		panic("evcnt_attach_static: name length (%s)", ev->ev_name);
731 #endif
732 	ev->ev_namelen = len;
733 
734 	TAILQ_INSERT_TAIL(&allevents, ev, ev_list);
735 }
736 
737 /*
738  * Attach a dynamically-initialized event.  Zero it, set up the type
739  * and string pointers and then act like it was statically initialized.
740  */
741 void
742 evcnt_attach_dynamic(struct evcnt *ev, int type, const struct evcnt *parent,
743     const char *group, const char *name)
744 {
745 
746 	memset(ev, 0, sizeof *ev);
747 	ev->ev_type = type;
748 	ev->ev_parent = parent;
749 	ev->ev_group = group;
750 	ev->ev_name = name;
751 	evcnt_attach_static(ev);
752 }
753 
754 /*
755  * Detach an event.
756  */
757 void
758 evcnt_detach(struct evcnt *ev)
759 {
760 
761 	TAILQ_REMOVE(&allevents, ev, ev_list);
762 }
763