xref: /netbsd-src/sys/kern/subr_autoconf.c (revision 17306b8fd0952c7489f93f0230818481e5a1e2c9)
1 /* $NetBSD: subr_autoconf.c,v 1.56 2001/05/28 16:40:31 thorpej 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 for the
18  *          NetBSD Project.  See http://www.netbsd.org/ for
19  *          information about NetBSD.
20  * 4. The name of the author may not be used to endorse or promote products
21  *    derived from this software without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
27  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33  *
34  * --(license Id: LICENSE.proto,v 1.1 2000/06/13 21:40:26 cgd Exp )--
35  */
36 
37 /*
38  * Copyright (c) 1992, 1993
39  *	The Regents of the University of California.  All rights reserved.
40  *
41  * This software was developed by the Computer Systems Engineering group
42  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
43  * contributed to Berkeley.
44  *
45  * All advertising materials mentioning features or use of this software
46  * must display the following acknowledgement:
47  *	This product includes software developed by the University of
48  *	California, Lawrence Berkeley Laboratories.
49  *
50  * Redistribution and use in source and binary forms, with or without
51  * modification, are permitted provided that the following conditions
52  * are met:
53  * 1. Redistributions of source code must retain the above copyright
54  *    notice, this list of conditions and the following disclaimer.
55  * 2. Redistributions in binary form must reproduce the above copyright
56  *    notice, this list of conditions and the following disclaimer in the
57  *    documentation and/or other materials provided with the distribution.
58  * 3. All advertising materials mentioning features or use of this software
59  *    must display the following acknowledgement:
60  *	This product includes software developed by the University of
61  *	California, Berkeley and its contributors.
62  * 4. Neither the name of the University nor the names of its contributors
63  *    may be used to endorse or promote products derived from this software
64  *    without specific prior written permission.
65  *
66  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
67  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
68  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
69  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
70  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
71  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
72  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
73  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
74  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
75  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
76  * SUCH DAMAGE.
77  *
78  * from: Header: subr_autoconf.c,v 1.12 93/02/01 19:31:48 torek Exp  (LBL)
79  *
80  *	@(#)subr_autoconf.c	8.3 (Berkeley) 5/17/94
81  */
82 
83 #include <sys/cdefs.h>
84 
85 __KERNEL_RCSID(0, "$NetBSD: subr_autoconf.c,v 1.56 2001/05/28 16:40:31 thorpej Exp $");
86 
87 #include <sys/param.h>
88 #include <sys/device.h>
89 #include <sys/malloc.h>
90 #include <sys/systm.h>
91 #include <sys/kernel.h>
92 #include <sys/errno.h>
93 #include <sys/proc.h>
94 #include <machine/limits.h>
95 
96 /*
97  * Autoconfiguration subroutines.
98  */
99 
100 /*
101  * ioconf.c exports exactly two names: cfdata and cfroots.  All system
102  * devices and drivers are found via these tables.
103  */
104 extern struct cfdata cfdata[];
105 extern short cfroots[];
106 
107 #define	ROOT ((struct device *)NULL)
108 
109 struct matchinfo {
110 	cfmatch_t fn;
111 	struct	device *parent;
112 	void	*aux;
113 	struct	cfdata *match;
114 	int	pri;
115 };
116 
117 static char *number(char *, int);
118 static void mapply(struct matchinfo *, struct cfdata *);
119 
120 struct deferred_config {
121 	TAILQ_ENTRY(deferred_config) dc_queue;
122 	struct device *dc_dev;
123 	void (*dc_func)(struct device *);
124 };
125 
126 TAILQ_HEAD(deferred_config_head, deferred_config);
127 
128 struct deferred_config_head deferred_config_queue;
129 struct deferred_config_head interrupt_config_queue;
130 
131 static void config_process_deferred(struct deferred_config_head *,
132 	struct device *);
133 
134 /* list of all devices */
135 struct devicelist alldevs;
136 
137 /* list of all events */
138 struct evcntlist allevents = TAILQ_HEAD_INITIALIZER(allevents);
139 
140 __volatile int config_pending;		/* semaphore for mountroot */
141 
142 /*
143  * Configure the system's hardware.
144  */
145 void
146 configure(void)
147 {
148 
149 	TAILQ_INIT(&deferred_config_queue);
150 	TAILQ_INIT(&interrupt_config_queue);
151 	TAILQ_INIT(&alldevs);
152 
153 	/*
154 	 * Do the machine-dependent portion of autoconfiguration.  This
155 	 * sets the configuration machinery here in motion by "finding"
156 	 * the root bus.  When this function returns, we expect interrupts
157 	 * to be enabled.
158 	 */
159 	cpu_configure();
160 
161 	/*
162 	 * Now that we've found all the hardware, start the real time
163 	 * and statistics clocks.
164 	 */
165 	initclocks();
166 
167 	cold = 0;	/* clocks are running, we're warm now! */
168 
169 	/*
170 	 * Now callback to finish configuration for devices which want
171 	 * to do this once interrupts are enabled.
172 	 */
173 	config_process_deferred(&interrupt_config_queue, NULL);
174 }
175 
176 /*
177  * Apply the matching function and choose the best.  This is used
178  * a few times and we want to keep the code small.
179  */
180 static void
181 mapply(struct matchinfo *m, struct cfdata *cf)
182 {
183 	int pri;
184 
185 	if (m->fn != NULL)
186 		pri = (*m->fn)(m->parent, cf, m->aux);
187 	else {
188 	        if (cf->cf_attach->ca_match == NULL) {
189 			panic("mapply: no match function for '%s' device\n",
190 			    cf->cf_driver->cd_name);
191 		}
192 		pri = (*cf->cf_attach->ca_match)(m->parent, cf, m->aux);
193 	}
194 	if (pri > m->pri) {
195 		m->match = cf;
196 		m->pri = pri;
197 	}
198 }
199 
200 /*
201  * Iterate over all potential children of some device, calling the given
202  * function (default being the child's match function) for each one.
203  * Nonzero returns are matches; the highest value returned is considered
204  * the best match.  Return the `found child' if we got a match, or NULL
205  * otherwise.  The `aux' pointer is simply passed on through.
206  *
207  * Note that this function is designed so that it can be used to apply
208  * an arbitrary function to all potential children (its return value
209  * can be ignored).
210  */
211 struct cfdata *
212 config_search(cfmatch_t fn, struct device *parent, void *aux)
213 {
214 	struct cfdata *cf;
215 	short *p;
216 	struct matchinfo m;
217 
218 	m.fn = fn;
219 	m.parent = parent;
220 	m.aux = aux;
221 	m.match = NULL;
222 	m.pri = 0;
223 	for (cf = cfdata; cf->cf_driver; cf++) {
224 		/*
225 		 * Skip cf if no longer eligible, otherwise scan through
226 		 * parents for one matching `parent', and try match function.
227 		 */
228 		if (cf->cf_fstate == FSTATE_FOUND)
229 			continue;
230 		for (p = cf->cf_parents; *p >= 0; p++)
231 			if (parent->dv_cfdata == &cfdata[*p])
232 				mapply(&m, cf);
233 	}
234 	return (m.match);
235 }
236 
237 /*
238  * Find the given root device.
239  * This is much like config_search, but there is no parent.
240  */
241 struct cfdata *
242 config_rootsearch(cfmatch_t fn, const char *rootname, void *aux)
243 {
244 	struct cfdata *cf;
245 	short *p;
246 	struct matchinfo m;
247 
248 	m.fn = fn;
249 	m.parent = ROOT;
250 	m.aux = aux;
251 	m.match = NULL;
252 	m.pri = 0;
253 	/*
254 	 * Look at root entries for matching name.  We do not bother
255 	 * with found-state here since only one root should ever be
256 	 * searched (and it must be done first).
257 	 */
258 	for (p = cfroots; *p >= 0; p++) {
259 		cf = &cfdata[*p];
260 		if (strcmp(cf->cf_driver->cd_name, rootname) == 0)
261 			mapply(&m, cf);
262 	}
263 	return (m.match);
264 }
265 
266 static const char *msgs[3] = { "", " not configured\n", " unsupported\n" };
267 
268 /*
269  * The given `aux' argument describes a device that has been found
270  * on the given parent, but not necessarily configured.  Locate the
271  * configuration data for that device (using the submatch function
272  * provided, or using candidates' cd_match configuration driver
273  * functions) and attach it, and return true.  If the device was
274  * not configured, call the given `print' function and return 0.
275  */
276 struct device *
277 config_found_sm(struct device *parent, void *aux, cfprint_t print,
278     cfmatch_t submatch)
279 {
280 	struct cfdata *cf;
281 
282 	if ((cf = config_search(submatch, parent, aux)) != NULL)
283 		return (config_attach(parent, cf, aux, print));
284 	if (print)
285 		printf("%s", msgs[(*print)(aux, parent->dv_xname)]);
286 	return (NULL);
287 }
288 
289 /*
290  * As above, but for root devices.
291  */
292 struct device *
293 config_rootfound(const char *rootname, void *aux)
294 {
295 	struct cfdata *cf;
296 
297 	if ((cf = config_rootsearch((cfmatch_t)NULL, rootname, aux)) != NULL)
298 		return (config_attach(ROOT, cf, aux, (cfprint_t)NULL));
299 	printf("root device %s not configured\n", rootname);
300 	return (NULL);
301 }
302 
303 /* just like sprintf(buf, "%d") except that it works from the end */
304 static char *
305 number(char *ep, int n)
306 {
307 
308 	*--ep = 0;
309 	while (n >= 10) {
310 		*--ep = (n % 10) + '0';
311 		n /= 10;
312 	}
313 	*--ep = n + '0';
314 	return (ep);
315 }
316 
317 /*
318  * Attach a found device.  Allocates memory for device variables.
319  */
320 struct device *
321 config_attach(struct device *parent, struct cfdata *cf, void *aux,
322 	cfprint_t print)
323 {
324 	struct device *dev;
325 	struct cfdriver *cd;
326 	struct cfattach *ca;
327 	size_t lname, lunit;
328 	const char *xunit;
329 	int myunit;
330 	char num[10];
331 
332 	cd = cf->cf_driver;
333 	ca = cf->cf_attach;
334 	if (ca->ca_devsize < sizeof(struct device))
335 		panic("config_attach");
336 #ifndef __BROKEN_CONFIG_UNIT_USAGE
337 	if (cf->cf_fstate == FSTATE_STAR) {
338 		for (myunit = cf->cf_unit; myunit < cd->cd_ndevs; myunit++)
339 			if (cd->cd_devs[myunit] == NULL)
340 				break;
341 		/*
342 		 * myunit is now the unit of the first NULL device pointer,
343 		 * or max(cd->cd_ndevs,cf->cf_unit).
344 		 */
345 	} else {
346 		myunit = cf->cf_unit;
347 #else /* __BROKEN_CONFIG_UNIT_USAGE */
348 	myunit = cf->cf_unit;
349 	if (cf->cf_fstate == FSTATE_STAR)
350 		cf->cf_unit++;
351 	else {
352 #endif /* __BROKEN_CONFIG_UNIT_USAGE */
353 		KASSERT(cf->cf_fstate == FSTATE_NOTFOUND);
354 		cf->cf_fstate = FSTATE_FOUND;
355 	}
356 
357 	/* compute length of name and decimal expansion of unit number */
358 	lname = strlen(cd->cd_name);
359 	xunit = number(&num[sizeof(num)], myunit);
360 	lunit = &num[sizeof(num)] - xunit;
361 	if (lname + lunit >= sizeof(dev->dv_xname))
362 		panic("config_attach: device name too long");
363 
364 	/* get memory for all device vars */
365 	dev = (struct device *)malloc(ca->ca_devsize, M_DEVBUF,
366 	    cold ? M_NOWAIT : M_WAITOK);
367 	if (!dev)
368 	    panic("config_attach: memory allocation for device softc failed");
369 	memset(dev, 0, ca->ca_devsize);
370 	TAILQ_INSERT_TAIL(&alldevs, dev, dv_list);	/* link up */
371 	dev->dv_class = cd->cd_class;
372 	dev->dv_cfdata = cf;
373 	dev->dv_unit = myunit;
374 	memcpy(dev->dv_xname, cd->cd_name, lname);
375 	memcpy(dev->dv_xname + lname, xunit, lunit);
376 	dev->dv_parent = parent;
377 	dev->dv_flags = DVF_ACTIVE;	/* always initially active */
378 
379 	if (parent == ROOT)
380 		printf("%s (root)", dev->dv_xname);
381 	else {
382 		printf("%s at %s", dev->dv_xname, parent->dv_xname);
383 		if (print)
384 			(void) (*print)(aux, NULL);
385 	}
386 
387 	/* put this device in the devices array */
388 	if (dev->dv_unit >= cd->cd_ndevs) {
389 		/*
390 		 * Need to expand the array.
391 		 */
392 		int old = cd->cd_ndevs, new;
393 		void **nsp;
394 
395 		if (old == 0)
396 			new = MINALLOCSIZE / sizeof(void *);
397 		else
398 			new = old * 2;
399 		while (new <= dev->dv_unit)
400 			new *= 2;
401 		cd->cd_ndevs = new;
402 		nsp = malloc(new * sizeof(void *), M_DEVBUF,
403 		    cold ? M_NOWAIT : M_WAITOK);
404 		if (nsp == 0)
405 			panic("config_attach: %sing dev array",
406 			    old != 0 ? "expand" : "creat");
407 		memset(nsp + old, 0, (new - old) * sizeof(void *));
408 		if (old != 0) {
409 			memcpy(nsp, cd->cd_devs, old * sizeof(void *));
410 			free(cd->cd_devs, M_DEVBUF);
411 		}
412 		cd->cd_devs = nsp;
413 	}
414 	if (cd->cd_devs[dev->dv_unit])
415 		panic("config_attach: duplicate %s", dev->dv_xname);
416 	cd->cd_devs[dev->dv_unit] = dev;
417 
418 	/*
419 	 * Before attaching, clobber any unfound devices that are
420 	 * otherwise identical.
421 	 */
422 #ifdef __BROKEN_CONFIG_UNIT_USAGE
423 	/* bump the unit number on all starred cfdata for this device. */
424 #endif /* __BROKEN_CONFIG_UNIT_USAGE */
425 	for (cf = cfdata; cf->cf_driver; cf++)
426 		if (cf->cf_driver == cd && cf->cf_unit == dev->dv_unit) {
427 			if (cf->cf_fstate == FSTATE_NOTFOUND)
428 				cf->cf_fstate = FSTATE_FOUND;
429 #ifdef __BROKEN_CONFIG_UNIT_USAGE
430 			if (cf->cf_fstate == FSTATE_STAR)
431 				cf->cf_unit++;
432 #endif /* __BROKEN_CONFIG_UNIT_USAGE */
433 		}
434 #ifdef __HAVE_DEVICE_REGISTER
435 	device_register(dev, aux);
436 #endif
437 	(*ca->ca_attach)(parent, dev, aux);
438 	config_process_deferred(&deferred_config_queue, dev);
439 	return (dev);
440 }
441 
442 /*
443  * Detach a device.  Optionally forced (e.g. because of hardware
444  * removal) and quiet.  Returns zero if successful, non-zero
445  * (an error code) otherwise.
446  *
447  * Note that this code wants to be run from a process context, so
448  * that the detach can sleep to allow processes which have a device
449  * open to run and unwind their stacks.
450  */
451 int
452 config_detach(struct device *dev, int flags)
453 {
454 	struct cfdata *cf;
455 	struct cfattach *ca;
456 	struct cfdriver *cd;
457 #ifdef DIAGNOSTIC
458 	struct device *d;
459 #endif
460 	int rv = 0, i;
461 
462 	cf = dev->dv_cfdata;
463 #ifdef DIAGNOSTIC
464 	if (cf->cf_fstate != FSTATE_FOUND && cf->cf_fstate != FSTATE_STAR)
465 		panic("config_detach: bad device fstate");
466 #endif
467 	ca = cf->cf_attach;
468 	cd = cf->cf_driver;
469 
470 	/*
471 	 * Ensure the device is deactivated.  If the device doesn't
472 	 * have an activation entry point, we allow DVF_ACTIVE to
473 	 * remain set.  Otherwise, if DVF_ACTIVE is still set, the
474 	 * device is busy, and the detach fails.
475 	 */
476 	if (ca->ca_activate != NULL)
477 		rv = config_deactivate(dev);
478 
479 	/*
480 	 * Try to detach the device.  If that's not possible, then
481 	 * we either panic() (for the forced but failed case), or
482 	 * return an error.
483 	 */
484 	if (rv == 0) {
485 		if (ca->ca_detach != NULL)
486 			rv = (*ca->ca_detach)(dev, flags);
487 		else
488 			rv = EOPNOTSUPP;
489 	}
490 	if (rv != 0) {
491 		if ((flags & DETACH_FORCE) == 0)
492 			return (rv);
493 		else
494 			panic("config_detach: forced detach of %s failed (%d)",
495 			    dev->dv_xname, rv);
496 	}
497 
498 	/*
499 	 * The device has now been successfully detached.
500 	 */
501 
502 #ifdef DIAGNOSTIC
503 	/*
504 	 * Sanity: If you're successfully detached, you should have no
505 	 * children.  (Note that because children must be attached
506 	 * after parents, we only need to search the latter part of
507 	 * the list.)
508 	 */
509 	for (d = TAILQ_NEXT(dev, dv_list); d != NULL;
510 	    d = TAILQ_NEXT(d, dv_list)) {
511 		if (d->dv_parent == dev) {
512 			printf("config_detach: detached device %s"
513 			    " has children %s\n", dev->dv_xname, d->dv_xname);
514 			panic("config_detach");
515 		}
516 	}
517 #endif
518 
519 	/*
520 	 * Mark cfdata to show that the unit can be reused, if possible.
521 	 */
522 #ifdef __BROKEN_CONFIG_UNIT_USAGE
523 	/*
524 	 * Note that we can only re-use a starred unit number if the unit
525 	 * being detached had the last assigned unit number.
526 	 */
527 #endif /* __BROKEN_CONFIG_UNIT_USAGE */
528 	for (cf = cfdata; cf->cf_driver; cf++) {
529 		if (cf->cf_driver == cd) {
530 			if (cf->cf_fstate == FSTATE_FOUND &&
531 			    cf->cf_unit == dev->dv_unit)
532 				cf->cf_fstate = FSTATE_NOTFOUND;
533 #ifdef __BROKEN_CONFIG_UNIT_USAGE
534 			if (cf->cf_fstate == FSTATE_STAR &&
535 			    cf->cf_unit == dev->dv_unit + 1)
536 				cf->cf_unit--;
537 #endif /* __BROKEN_CONFIG_UNIT_USAGE */
538 		}
539 	}
540 
541 	/*
542 	 * Unlink from device list.
543 	 */
544 	TAILQ_REMOVE(&alldevs, dev, dv_list);
545 
546 	/*
547 	 * Remove from cfdriver's array, tell the world, and free softc.
548 	 */
549 	cd->cd_devs[dev->dv_unit] = NULL;
550 	if ((flags & DETACH_QUIET) == 0)
551 		printf("%s detached\n", dev->dv_xname);
552 	free(dev, M_DEVBUF);
553 
554 	/*
555 	 * If the device now has no units in use, deallocate its softc array.
556 	 */
557 	for (i = 0; i < cd->cd_ndevs; i++)
558 		if (cd->cd_devs[i] != NULL)
559 			break;
560 	if (i == cd->cd_ndevs) {		/* nothing found; deallocate */
561 		free(cd->cd_devs, M_DEVBUF);
562 		cd->cd_devs = NULL;
563 		cd->cd_ndevs = 0;
564 	}
565 
566 	/*
567 	 * Return success.
568 	 */
569 	return (0);
570 }
571 
572 int
573 config_activate(struct device *dev)
574 {
575 	struct cfattach *ca = dev->dv_cfdata->cf_attach;
576 	int rv = 0, oflags = dev->dv_flags;
577 
578 	if (ca->ca_activate == NULL)
579 		return (EOPNOTSUPP);
580 
581 	if ((dev->dv_flags & DVF_ACTIVE) == 0) {
582 		dev->dv_flags |= DVF_ACTIVE;
583 		rv = (*ca->ca_activate)(dev, DVACT_ACTIVATE);
584 		if (rv)
585 			dev->dv_flags = oflags;
586 	}
587 	return (rv);
588 }
589 
590 int
591 config_deactivate(struct device *dev)
592 {
593 	struct cfattach *ca = dev->dv_cfdata->cf_attach;
594 	int rv = 0, oflags = dev->dv_flags;
595 
596 	if (ca->ca_activate == NULL)
597 		return (EOPNOTSUPP);
598 
599 	if (dev->dv_flags & DVF_ACTIVE) {
600 		dev->dv_flags &= ~DVF_ACTIVE;
601 		rv = (*ca->ca_activate)(dev, DVACT_DEACTIVATE);
602 		if (rv)
603 			dev->dv_flags = oflags;
604 	}
605 	return (rv);
606 }
607 
608 /*
609  * Defer the configuration of the specified device until all
610  * of its parent's devices have been attached.
611  */
612 void
613 config_defer(struct device *dev, void (*func)(struct device *))
614 {
615 	struct deferred_config *dc;
616 
617 	if (dev->dv_parent == NULL)
618 		panic("config_defer: can't defer config of a root device");
619 
620 #ifdef DIAGNOSTIC
621 	for (dc = TAILQ_FIRST(&deferred_config_queue); dc != NULL;
622 	     dc = TAILQ_NEXT(dc, dc_queue)) {
623 		if (dc->dc_dev == dev)
624 			panic("config_defer: deferred twice");
625 	}
626 #endif
627 
628 	dc = malloc(sizeof(*dc), M_DEVBUF, cold ? M_NOWAIT : M_WAITOK);
629 	if (dc == NULL)
630 		panic("config_defer: unable to allocate callback");
631 
632 	dc->dc_dev = dev;
633 	dc->dc_func = func;
634 	TAILQ_INSERT_TAIL(&deferred_config_queue, dc, dc_queue);
635 	config_pending_incr();
636 }
637 
638 /*
639  * Defer some autoconfiguration for a device until after interrupts
640  * are enabled.
641  */
642 void
643 config_interrupts(struct device *dev, void (*func)(struct device *))
644 {
645 	struct deferred_config *dc;
646 
647 	/*
648 	 * If interrupts are enabled, callback now.
649 	 */
650 	if (cold == 0) {
651 		(*func)(dev);
652 		return;
653 	}
654 
655 #ifdef DIAGNOSTIC
656 	for (dc = TAILQ_FIRST(&interrupt_config_queue); dc != NULL;
657 	     dc = TAILQ_NEXT(dc, dc_queue)) {
658 		if (dc->dc_dev == dev)
659 			panic("config_interrupts: deferred twice");
660 	}
661 #endif
662 
663 	dc = malloc(sizeof(*dc), M_DEVBUF, cold ? M_NOWAIT : M_WAITOK);
664 	if (dc == NULL)
665 		panic("config_interrupts: unable to allocate callback");
666 
667 	dc->dc_dev = dev;
668 	dc->dc_func = func;
669 	TAILQ_INSERT_TAIL(&interrupt_config_queue, dc, dc_queue);
670 	config_pending_incr();
671 }
672 
673 /*
674  * Process a deferred configuration queue.
675  */
676 static void
677 config_process_deferred(struct deferred_config_head *queue,
678     struct device *parent)
679 {
680 	struct deferred_config *dc, *ndc;
681 
682 	for (dc = TAILQ_FIRST(queue); dc != NULL; dc = ndc) {
683 		ndc = TAILQ_NEXT(dc, dc_queue);
684 		if (parent == NULL || dc->dc_dev->dv_parent == parent) {
685 			TAILQ_REMOVE(queue, dc, dc_queue);
686 			(*dc->dc_func)(dc->dc_dev);
687 			free(dc, M_DEVBUF);
688 			config_pending_decr();
689 		}
690 	}
691 }
692 
693 /*
694  * Manipulate the config_pending semaphore.
695  */
696 void
697 config_pending_incr(void)
698 {
699 
700 	config_pending++;
701 }
702 
703 void
704 config_pending_decr(void)
705 {
706 
707 #ifdef DIAGNOSTIC
708 	if (config_pending == 0)
709 		panic("config_pending_decr: config_pending == 0");
710 #endif
711 	config_pending--;
712 	if (config_pending == 0)
713 		wakeup((void *)&config_pending);
714 }
715 
716 /*
717  * Attach a statically-initialized event.  The type and string pointers
718  * are already set up.
719  */
720 void
721 evcnt_attach_static(struct evcnt *ev)
722 {
723 	int len;
724 
725 	len = strlen(ev->ev_group);
726 #ifdef DIAGNOSTIC
727 	if (len >= EVCNT_STRING_MAX)		/* ..._MAX includes NUL */
728 		panic("evcnt_attach_static: group length (%s)", ev->ev_group);
729 #endif
730 	ev->ev_grouplen = len;
731 
732 	len = strlen(ev->ev_name);
733 #ifdef DIAGNOSTIC
734 	if (len >= EVCNT_STRING_MAX)		/* ..._MAX includes NUL */
735 		panic("evcnt_attach_static: name length (%s)", ev->ev_name);
736 #endif
737 	ev->ev_namelen = len;
738 
739 	TAILQ_INSERT_TAIL(&allevents, ev, ev_list);
740 }
741 
742 /*
743  * Attach a dynamically-initialized event.  Zero it, set up the type
744  * and string pointers and then act like it was statically initialized.
745  */
746 void
747 evcnt_attach_dynamic(struct evcnt *ev, int type, const struct evcnt *parent,
748     const char *group, const char *name)
749 {
750 
751 	memset(ev, 0, sizeof *ev);
752 	ev->ev_type = type;
753 	ev->ev_parent = parent;
754 	ev->ev_group = group;
755 	ev->ev_name = name;
756 	evcnt_attach_static(ev);
757 }
758 
759 /*
760  * Detach an event.
761  */
762 void
763 evcnt_detach(struct evcnt *ev)
764 {
765 
766 	TAILQ_REMOVE(&allevents, ev, ev_list);
767 }
768