xref: /netbsd-src/sys/kern/subr_autoconf.c (revision 4724848cf0da353df257f730694b7882798e5daf)
1 /* $NetBSD: subr_autoconf.c,v 1.309 2023/04/16 11:18:25 riastradh 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. Neither the name of the University nor the names of its contributors
59  *    may be used to endorse or promote products derived from this software
60  *    without specific prior written permission.
61  *
62  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
63  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
64  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
65  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
66  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
67  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
68  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
69  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
70  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
71  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
72  * SUCH DAMAGE.
73  *
74  * from: Header: subr_autoconf.c,v 1.12 93/02/01 19:31:48 torek Exp  (LBL)
75  *
76  *	@(#)subr_autoconf.c	8.3 (Berkeley) 5/17/94
77  */
78 
79 #include <sys/cdefs.h>
80 __KERNEL_RCSID(0, "$NetBSD: subr_autoconf.c,v 1.309 2023/04/16 11:18:25 riastradh Exp $");
81 
82 #ifdef _KERNEL_OPT
83 #include "opt_ddb.h"
84 #include "drvctl.h"
85 #endif
86 
87 #include <sys/param.h>
88 #include <sys/device.h>
89 #include <sys/device_impl.h>
90 #include <sys/disklabel.h>
91 #include <sys/conf.h>
92 #include <sys/kauth.h>
93 #include <sys/kmem.h>
94 #include <sys/systm.h>
95 #include <sys/kernel.h>
96 #include <sys/errno.h>
97 #include <sys/proc.h>
98 #include <sys/reboot.h>
99 #include <sys/kthread.h>
100 #include <sys/buf.h>
101 #include <sys/dirent.h>
102 #include <sys/mount.h>
103 #include <sys/namei.h>
104 #include <sys/unistd.h>
105 #include <sys/fcntl.h>
106 #include <sys/lockf.h>
107 #include <sys/callout.h>
108 #include <sys/devmon.h>
109 #include <sys/cpu.h>
110 #include <sys/sysctl.h>
111 #include <sys/stdarg.h>
112 #include <sys/localcount.h>
113 
114 #include <sys/disk.h>
115 
116 #include <sys/rndsource.h>
117 
118 #include <machine/limits.h>
119 
120 /*
121  * Autoconfiguration subroutines.
122  */
123 
124 /*
125  * Device autoconfiguration timings are mixed into the entropy pool.
126  */
127 static krndsource_t rnd_autoconf_source;
128 
129 /*
130  * ioconf.c exports exactly two names: cfdata and cfroots.  All system
131  * devices and drivers are found via these tables.
132  */
133 extern struct cfdata cfdata[];
134 extern const short cfroots[];
135 
136 /*
137  * List of all cfdriver structures.  We use this to detect duplicates
138  * when other cfdrivers are loaded.
139  */
140 struct cfdriverlist allcfdrivers = LIST_HEAD_INITIALIZER(&allcfdrivers);
141 extern struct cfdriver * const cfdriver_list_initial[];
142 
143 /*
144  * Initial list of cfattach's.
145  */
146 extern const struct cfattachinit cfattachinit[];
147 
148 /*
149  * List of cfdata tables.  We always have one such list -- the one
150  * built statically when the kernel was configured.
151  */
152 struct cftablelist allcftables = TAILQ_HEAD_INITIALIZER(allcftables);
153 static struct cftable initcftable;
154 
155 #define	ROOT ((device_t)NULL)
156 
157 struct matchinfo {
158 	cfsubmatch_t fn;
159 	device_t parent;
160 	const int *locs;
161 	void	*aux;
162 	struct	cfdata *match;
163 	int	pri;
164 };
165 
166 struct alldevs_foray {
167 	int			af_s;
168 	struct devicelist	af_garbage;
169 };
170 
171 /*
172  * Internal version of the cfargs structure; all versions are
173  * canonicalized to this.
174  */
175 struct cfargs_internal {
176 	union {
177 		cfsubmatch_t	submatch;/* submatch function (direct config) */
178 		cfsearch_t	search;	 /* search function (indirect config) */
179 	};
180 	const char *	iattr;		/* interface attribute */
181 	const int *	locators;	/* locators array */
182 	devhandle_t	devhandle;	/* devhandle_t (by value) */
183 };
184 
185 static char *number(char *, int);
186 static void mapply(struct matchinfo *, cfdata_t);
187 static void config_devdelete(device_t);
188 static void config_devunlink(device_t, struct devicelist *);
189 static void config_makeroom(int, struct cfdriver *);
190 static void config_devlink(device_t);
191 static void config_alldevs_enter(struct alldevs_foray *);
192 static void config_alldevs_exit(struct alldevs_foray *);
193 static void config_add_attrib_dict(device_t);
194 static device_t	config_attach_internal(device_t, cfdata_t, void *,
195 		    cfprint_t, const struct cfargs_internal *);
196 
197 static void config_collect_garbage(struct devicelist *);
198 static void config_dump_garbage(struct devicelist *);
199 
200 static void pmflock_debug(device_t, const char *, int);
201 
202 static device_t deviter_next1(deviter_t *);
203 static void deviter_reinit(deviter_t *);
204 
205 struct deferred_config {
206 	TAILQ_ENTRY(deferred_config) dc_queue;
207 	device_t dc_dev;
208 	void (*dc_func)(device_t);
209 };
210 
211 TAILQ_HEAD(deferred_config_head, deferred_config);
212 
213 static struct deferred_config_head deferred_config_queue =
214 	TAILQ_HEAD_INITIALIZER(deferred_config_queue);
215 static struct deferred_config_head interrupt_config_queue =
216 	TAILQ_HEAD_INITIALIZER(interrupt_config_queue);
217 static int interrupt_config_threads = 8;
218 static struct deferred_config_head mountroot_config_queue =
219 	TAILQ_HEAD_INITIALIZER(mountroot_config_queue);
220 static int mountroot_config_threads = 2;
221 static lwp_t **mountroot_config_lwpids;
222 static size_t mountroot_config_lwpids_size;
223 bool root_is_mounted = false;
224 
225 static void config_process_deferred(struct deferred_config_head *, device_t);
226 
227 /* Hooks to finalize configuration once all real devices have been found. */
228 struct finalize_hook {
229 	TAILQ_ENTRY(finalize_hook) f_list;
230 	int (*f_func)(device_t);
231 	device_t f_dev;
232 };
233 static TAILQ_HEAD(, finalize_hook) config_finalize_list =
234 	TAILQ_HEAD_INITIALIZER(config_finalize_list);
235 static int config_finalize_done;
236 
237 /* list of all devices */
238 static struct devicelist alldevs = TAILQ_HEAD_INITIALIZER(alldevs);
239 static kmutex_t alldevs_lock __cacheline_aligned;
240 static devgen_t alldevs_gen = 1;
241 static int alldevs_nread = 0;
242 static int alldevs_nwrite = 0;
243 static bool alldevs_garbage = false;
244 
245 static struct devicelist config_pending =
246     TAILQ_HEAD_INITIALIZER(config_pending);
247 static kmutex_t config_misc_lock;
248 static kcondvar_t config_misc_cv;
249 
250 static bool detachall = false;
251 
252 #define	STREQ(s1, s2)			\
253 	(*(s1) == *(s2) && strcmp((s1), (s2)) == 0)
254 
255 static bool config_initialized = false;	/* config_init() has been called. */
256 
257 static int config_do_twiddle;
258 static callout_t config_twiddle_ch;
259 
260 static void sysctl_detach_setup(struct sysctllog **);
261 
262 int no_devmon_insert(const char *, prop_dictionary_t);
263 int (*devmon_insert_vec)(const char *, prop_dictionary_t) = no_devmon_insert;
264 
265 typedef int (*cfdriver_fn)(struct cfdriver *);
266 static int
267 frob_cfdrivervec(struct cfdriver * const *cfdriverv,
268 	cfdriver_fn drv_do, cfdriver_fn drv_undo,
269 	const char *style, bool dopanic)
270 {
271 	void (*pr)(const char *, ...) __printflike(1, 2) =
272 	    dopanic ? panic : printf;
273 	int i, error = 0, e2 __diagused;
274 
275 	for (i = 0; cfdriverv[i] != NULL; i++) {
276 		if ((error = drv_do(cfdriverv[i])) != 0) {
277 			pr("configure: `%s' driver %s failed: %d",
278 			    cfdriverv[i]->cd_name, style, error);
279 			goto bad;
280 		}
281 	}
282 
283 	KASSERT(error == 0);
284 	return 0;
285 
286  bad:
287 	printf("\n");
288 	for (i--; i >= 0; i--) {
289 		e2 = drv_undo(cfdriverv[i]);
290 		KASSERT(e2 == 0);
291 	}
292 
293 	return error;
294 }
295 
296 typedef int (*cfattach_fn)(const char *, struct cfattach *);
297 static int
298 frob_cfattachvec(const struct cfattachinit *cfattachv,
299 	cfattach_fn att_do, cfattach_fn att_undo,
300 	const char *style, bool dopanic)
301 {
302 	const struct cfattachinit *cfai = NULL;
303 	void (*pr)(const char *, ...) __printflike(1, 2) =
304 	    dopanic ? panic : printf;
305 	int j = 0, error = 0, e2 __diagused;
306 
307 	for (cfai = &cfattachv[0]; cfai->cfai_name != NULL; cfai++) {
308 		for (j = 0; cfai->cfai_list[j] != NULL; j++) {
309 			if ((error = att_do(cfai->cfai_name,
310 			    cfai->cfai_list[j])) != 0) {
311 				pr("configure: attachment `%s' "
312 				    "of `%s' driver %s failed: %d",
313 				    cfai->cfai_list[j]->ca_name,
314 				    cfai->cfai_name, style, error);
315 				goto bad;
316 			}
317 		}
318 	}
319 
320 	KASSERT(error == 0);
321 	return 0;
322 
323  bad:
324 	/*
325 	 * Rollback in reverse order.  dunno if super-important, but
326 	 * do that anyway.  Although the code looks a little like
327 	 * someone did a little integration (in the math sense).
328 	 */
329 	printf("\n");
330 	if (cfai) {
331 		bool last;
332 
333 		for (last = false; last == false; ) {
334 			if (cfai == &cfattachv[0])
335 				last = true;
336 			for (j--; j >= 0; j--) {
337 				e2 = att_undo(cfai->cfai_name,
338 				    cfai->cfai_list[j]);
339 				KASSERT(e2 == 0);
340 			}
341 			if (!last) {
342 				cfai--;
343 				for (j = 0; cfai->cfai_list[j] != NULL; j++)
344 					;
345 			}
346 		}
347 	}
348 
349 	return error;
350 }
351 
352 /*
353  * Initialize the autoconfiguration data structures.  Normally this
354  * is done by configure(), but some platforms need to do this very
355  * early (to e.g. initialize the console).
356  */
357 void
358 config_init(void)
359 {
360 
361 	KASSERT(config_initialized == false);
362 
363 	mutex_init(&alldevs_lock, MUTEX_DEFAULT, IPL_VM);
364 
365 	mutex_init(&config_misc_lock, MUTEX_DEFAULT, IPL_NONE);
366 	cv_init(&config_misc_cv, "cfgmisc");
367 
368 	callout_init(&config_twiddle_ch, CALLOUT_MPSAFE);
369 
370 	frob_cfdrivervec(cfdriver_list_initial,
371 	    config_cfdriver_attach, NULL, "bootstrap", true);
372 	frob_cfattachvec(cfattachinit,
373 	    config_cfattach_attach, NULL, "bootstrap", true);
374 
375 	initcftable.ct_cfdata = cfdata;
376 	TAILQ_INSERT_TAIL(&allcftables, &initcftable, ct_list);
377 
378 	rnd_attach_source(&rnd_autoconf_source, "autoconf", RND_TYPE_UNKNOWN,
379 	    RND_FLAG_COLLECT_TIME);
380 
381 	config_initialized = true;
382 }
383 
384 /*
385  * Init or fini drivers and attachments.  Either all or none
386  * are processed (via rollback).  It would be nice if this were
387  * atomic to outside consumers, but with the current state of
388  * locking ...
389  */
390 int
391 config_init_component(struct cfdriver * const *cfdriverv,
392 	const struct cfattachinit *cfattachv, struct cfdata *cfdatav)
393 {
394 	int error;
395 
396 	KERNEL_LOCK(1, NULL);
397 
398 	if ((error = frob_cfdrivervec(cfdriverv,
399 	    config_cfdriver_attach, config_cfdriver_detach, "init", false))!= 0)
400 		goto out;
401 	if ((error = frob_cfattachvec(cfattachv,
402 	    config_cfattach_attach, config_cfattach_detach,
403 	    "init", false)) != 0) {
404 		frob_cfdrivervec(cfdriverv,
405 	            config_cfdriver_detach, NULL, "init rollback", true);
406 		goto out;
407 	}
408 	if ((error = config_cfdata_attach(cfdatav, 1)) != 0) {
409 		frob_cfattachvec(cfattachv,
410 		    config_cfattach_detach, NULL, "init rollback", true);
411 		frob_cfdrivervec(cfdriverv,
412 	            config_cfdriver_detach, NULL, "init rollback", true);
413 		goto out;
414 	}
415 
416 	/* Success!  */
417 	error = 0;
418 
419 out:	KERNEL_UNLOCK_ONE(NULL);
420 	return error;
421 }
422 
423 int
424 config_fini_component(struct cfdriver * const *cfdriverv,
425 	const struct cfattachinit *cfattachv, struct cfdata *cfdatav)
426 {
427 	int error;
428 
429 	KERNEL_LOCK(1, NULL);
430 
431 	if ((error = config_cfdata_detach(cfdatav)) != 0)
432 		goto out;
433 	if ((error = frob_cfattachvec(cfattachv,
434 	    config_cfattach_detach, config_cfattach_attach,
435 	    "fini", false)) != 0) {
436 		if (config_cfdata_attach(cfdatav, 0) != 0)
437 			panic("config_cfdata fini rollback failed");
438 		goto out;
439 	}
440 	if ((error = frob_cfdrivervec(cfdriverv,
441 	    config_cfdriver_detach, config_cfdriver_attach,
442 	    "fini", false)) != 0) {
443 		frob_cfattachvec(cfattachv,
444 	            config_cfattach_attach, NULL, "fini rollback", true);
445 		if (config_cfdata_attach(cfdatav, 0) != 0)
446 			panic("config_cfdata fini rollback failed");
447 		goto out;
448 	}
449 
450 	/* Success!  */
451 	error = 0;
452 
453 out:	KERNEL_UNLOCK_ONE(NULL);
454 	return error;
455 }
456 
457 void
458 config_init_mi(void)
459 {
460 
461 	if (!config_initialized)
462 		config_init();
463 
464 	sysctl_detach_setup(NULL);
465 }
466 
467 void
468 config_deferred(device_t dev)
469 {
470 
471 	KASSERT(KERNEL_LOCKED_P());
472 
473 	config_process_deferred(&deferred_config_queue, dev);
474 	config_process_deferred(&interrupt_config_queue, dev);
475 	config_process_deferred(&mountroot_config_queue, dev);
476 }
477 
478 static void
479 config_interrupts_thread(void *cookie)
480 {
481 	struct deferred_config *dc;
482 	device_t dev;
483 
484 	mutex_enter(&config_misc_lock);
485 	while ((dc = TAILQ_FIRST(&interrupt_config_queue)) != NULL) {
486 		TAILQ_REMOVE(&interrupt_config_queue, dc, dc_queue);
487 		mutex_exit(&config_misc_lock);
488 
489 		dev = dc->dc_dev;
490 		(*dc->dc_func)(dev);
491 		if (!device_pmf_is_registered(dev))
492 			aprint_debug_dev(dev,
493 			    "WARNING: power management not supported\n");
494 		config_pending_decr(dev);
495 		kmem_free(dc, sizeof(*dc));
496 
497 		mutex_enter(&config_misc_lock);
498 	}
499 	mutex_exit(&config_misc_lock);
500 
501 	kthread_exit(0);
502 }
503 
504 void
505 config_create_interruptthreads(void)
506 {
507 	int i;
508 
509 	for (i = 0; i < interrupt_config_threads; i++) {
510 		(void)kthread_create(PRI_NONE, 0/*XXXSMP */, NULL,
511 		    config_interrupts_thread, NULL, NULL, "configintr");
512 	}
513 }
514 
515 static void
516 config_mountroot_thread(void *cookie)
517 {
518 	struct deferred_config *dc;
519 
520 	mutex_enter(&config_misc_lock);
521 	while ((dc = TAILQ_FIRST(&mountroot_config_queue)) != NULL) {
522 		TAILQ_REMOVE(&mountroot_config_queue, dc, dc_queue);
523 		mutex_exit(&config_misc_lock);
524 
525 		(*dc->dc_func)(dc->dc_dev);
526 		kmem_free(dc, sizeof(*dc));
527 
528 		mutex_enter(&config_misc_lock);
529 	}
530 	mutex_exit(&config_misc_lock);
531 
532 	kthread_exit(0);
533 }
534 
535 void
536 config_create_mountrootthreads(void)
537 {
538 	int i;
539 
540 	if (!root_is_mounted)
541 		root_is_mounted = true;
542 
543 	mountroot_config_lwpids_size = sizeof(mountroot_config_lwpids) *
544 				       mountroot_config_threads;
545 	mountroot_config_lwpids = kmem_alloc(mountroot_config_lwpids_size,
546 					     KM_NOSLEEP);
547 	KASSERT(mountroot_config_lwpids);
548 	for (i = 0; i < mountroot_config_threads; i++) {
549 		mountroot_config_lwpids[i] = 0;
550 		(void)kthread_create(PRI_NONE, KTHREAD_MUSTJOIN/* XXXSMP */,
551 				     NULL, config_mountroot_thread, NULL,
552 				     &mountroot_config_lwpids[i],
553 				     "configroot");
554 	}
555 }
556 
557 void
558 config_finalize_mountroot(void)
559 {
560 	int i, error;
561 
562 	for (i = 0; i < mountroot_config_threads; i++) {
563 		if (mountroot_config_lwpids[i] == 0)
564 			continue;
565 
566 		error = kthread_join(mountroot_config_lwpids[i]);
567 		if (error)
568 			printf("%s: thread %x joined with error %d\n",
569 			       __func__, i, error);
570 	}
571 	kmem_free(mountroot_config_lwpids, mountroot_config_lwpids_size);
572 }
573 
574 /*
575  * Announce device attach/detach to userland listeners.
576  */
577 
578 int
579 no_devmon_insert(const char *name, prop_dictionary_t p)
580 {
581 
582 	return ENODEV;
583 }
584 
585 static void
586 devmon_report_device(device_t dev, bool isattach)
587 {
588 	prop_dictionary_t ev, dict = device_properties(dev);
589 	const char *parent;
590 	const char *what;
591 	const char *where;
592 	device_t pdev = device_parent(dev);
593 
594 	/* If currently no drvctl device, just return */
595 	if (devmon_insert_vec == no_devmon_insert)
596 		return;
597 
598 	ev = prop_dictionary_create();
599 	if (ev == NULL)
600 		return;
601 
602 	what = (isattach ? "device-attach" : "device-detach");
603 	parent = (pdev == NULL ? "root" : device_xname(pdev));
604 	if (prop_dictionary_get_string(dict, "location", &where)) {
605 		prop_dictionary_set_string(ev, "location", where);
606 		aprint_debug("ev: %s %s at %s in [%s]\n",
607 		    what, device_xname(dev), parent, where);
608 	}
609 	if (!prop_dictionary_set_string(ev, "device", device_xname(dev)) ||
610 	    !prop_dictionary_set_string(ev, "parent", parent)) {
611 		prop_object_release(ev);
612 		return;
613 	}
614 
615 	if ((*devmon_insert_vec)(what, ev) != 0)
616 		prop_object_release(ev);
617 }
618 
619 /*
620  * Add a cfdriver to the system.
621  */
622 int
623 config_cfdriver_attach(struct cfdriver *cd)
624 {
625 	struct cfdriver *lcd;
626 
627 	/* Make sure this driver isn't already in the system. */
628 	LIST_FOREACH(lcd, &allcfdrivers, cd_list) {
629 		if (STREQ(lcd->cd_name, cd->cd_name))
630 			return EEXIST;
631 	}
632 
633 	LIST_INIT(&cd->cd_attach);
634 	LIST_INSERT_HEAD(&allcfdrivers, cd, cd_list);
635 
636 	return 0;
637 }
638 
639 /*
640  * Remove a cfdriver from the system.
641  */
642 int
643 config_cfdriver_detach(struct cfdriver *cd)
644 {
645 	struct alldevs_foray af;
646 	int i, rc = 0;
647 
648 	config_alldevs_enter(&af);
649 	/* Make sure there are no active instances. */
650 	for (i = 0; i < cd->cd_ndevs; i++) {
651 		if (cd->cd_devs[i] != NULL) {
652 			rc = EBUSY;
653 			break;
654 		}
655 	}
656 	config_alldevs_exit(&af);
657 
658 	if (rc != 0)
659 		return rc;
660 
661 	/* ...and no attachments loaded. */
662 	if (LIST_EMPTY(&cd->cd_attach) == 0)
663 		return EBUSY;
664 
665 	LIST_REMOVE(cd, cd_list);
666 
667 	KASSERT(cd->cd_devs == NULL);
668 
669 	return 0;
670 }
671 
672 /*
673  * Look up a cfdriver by name.
674  */
675 struct cfdriver *
676 config_cfdriver_lookup(const char *name)
677 {
678 	struct cfdriver *cd;
679 
680 	LIST_FOREACH(cd, &allcfdrivers, cd_list) {
681 		if (STREQ(cd->cd_name, name))
682 			return cd;
683 	}
684 
685 	return NULL;
686 }
687 
688 /*
689  * Add a cfattach to the specified driver.
690  */
691 int
692 config_cfattach_attach(const char *driver, struct cfattach *ca)
693 {
694 	struct cfattach *lca;
695 	struct cfdriver *cd;
696 
697 	cd = config_cfdriver_lookup(driver);
698 	if (cd == NULL)
699 		return ESRCH;
700 
701 	/* Make sure this attachment isn't already on this driver. */
702 	LIST_FOREACH(lca, &cd->cd_attach, ca_list) {
703 		if (STREQ(lca->ca_name, ca->ca_name))
704 			return EEXIST;
705 	}
706 
707 	LIST_INSERT_HEAD(&cd->cd_attach, ca, ca_list);
708 
709 	return 0;
710 }
711 
712 /*
713  * Remove a cfattach from the specified driver.
714  */
715 int
716 config_cfattach_detach(const char *driver, struct cfattach *ca)
717 {
718 	struct alldevs_foray af;
719 	struct cfdriver *cd;
720 	device_t dev;
721 	int i, rc = 0;
722 
723 	cd = config_cfdriver_lookup(driver);
724 	if (cd == NULL)
725 		return ESRCH;
726 
727 	config_alldevs_enter(&af);
728 	/* Make sure there are no active instances. */
729 	for (i = 0; i < cd->cd_ndevs; i++) {
730 		if ((dev = cd->cd_devs[i]) == NULL)
731 			continue;
732 		if (dev->dv_cfattach == ca) {
733 			rc = EBUSY;
734 			break;
735 		}
736 	}
737 	config_alldevs_exit(&af);
738 
739 	if (rc != 0)
740 		return rc;
741 
742 	LIST_REMOVE(ca, ca_list);
743 
744 	return 0;
745 }
746 
747 /*
748  * Look up a cfattach by name.
749  */
750 static struct cfattach *
751 config_cfattach_lookup_cd(struct cfdriver *cd, const char *atname)
752 {
753 	struct cfattach *ca;
754 
755 	LIST_FOREACH(ca, &cd->cd_attach, ca_list) {
756 		if (STREQ(ca->ca_name, atname))
757 			return ca;
758 	}
759 
760 	return NULL;
761 }
762 
763 /*
764  * Look up a cfattach by driver/attachment name.
765  */
766 struct cfattach *
767 config_cfattach_lookup(const char *name, const char *atname)
768 {
769 	struct cfdriver *cd;
770 
771 	cd = config_cfdriver_lookup(name);
772 	if (cd == NULL)
773 		return NULL;
774 
775 	return config_cfattach_lookup_cd(cd, atname);
776 }
777 
778 /*
779  * Apply the matching function and choose the best.  This is used
780  * a few times and we want to keep the code small.
781  */
782 static void
783 mapply(struct matchinfo *m, cfdata_t cf)
784 {
785 	int pri;
786 
787 	if (m->fn != NULL) {
788 		pri = (*m->fn)(m->parent, cf, m->locs, m->aux);
789 	} else {
790 		pri = config_match(m->parent, cf, m->aux);
791 	}
792 	if (pri > m->pri) {
793 		m->match = cf;
794 		m->pri = pri;
795 	}
796 }
797 
798 int
799 config_stdsubmatch(device_t parent, cfdata_t cf, const int *locs, void *aux)
800 {
801 	const struct cfiattrdata *ci;
802 	const struct cflocdesc *cl;
803 	int nlocs, i;
804 
805 	ci = cfiattr_lookup(cfdata_ifattr(cf), parent->dv_cfdriver);
806 	KASSERT(ci);
807 	nlocs = ci->ci_loclen;
808 	KASSERT(!nlocs || locs);
809 	for (i = 0; i < nlocs; i++) {
810 		cl = &ci->ci_locdesc[i];
811 		if (cl->cld_defaultstr != NULL &&
812 		    cf->cf_loc[i] == cl->cld_default)
813 			continue;
814 		if (cf->cf_loc[i] == locs[i])
815 			continue;
816 		return 0;
817 	}
818 
819 	return config_match(parent, cf, aux);
820 }
821 
822 /*
823  * Helper function: check whether the driver supports the interface attribute
824  * and return its descriptor structure.
825  */
826 static const struct cfiattrdata *
827 cfdriver_get_iattr(const struct cfdriver *cd, const char *ia)
828 {
829 	const struct cfiattrdata * const *cpp;
830 
831 	if (cd->cd_attrs == NULL)
832 		return 0;
833 
834 	for (cpp = cd->cd_attrs; *cpp; cpp++) {
835 		if (STREQ((*cpp)->ci_name, ia)) {
836 			/* Match. */
837 			return *cpp;
838 		}
839 	}
840 	return 0;
841 }
842 
843 static int __diagused
844 cfdriver_iattr_count(const struct cfdriver *cd)
845 {
846 	const struct cfiattrdata * const *cpp;
847 	int i;
848 
849 	if (cd->cd_attrs == NULL)
850 		return 0;
851 
852 	for (i = 0, cpp = cd->cd_attrs; *cpp; cpp++) {
853 		i++;
854 	}
855 	return i;
856 }
857 
858 /*
859  * Lookup an interface attribute description by name.
860  * If the driver is given, consider only its supported attributes.
861  */
862 const struct cfiattrdata *
863 cfiattr_lookup(const char *name, const struct cfdriver *cd)
864 {
865 	const struct cfdriver *d;
866 	const struct cfiattrdata *ia;
867 
868 	if (cd)
869 		return cfdriver_get_iattr(cd, name);
870 
871 	LIST_FOREACH(d, &allcfdrivers, cd_list) {
872 		ia = cfdriver_get_iattr(d, name);
873 		if (ia)
874 			return ia;
875 	}
876 	return 0;
877 }
878 
879 /*
880  * Determine if `parent' is a potential parent for a device spec based
881  * on `cfp'.
882  */
883 static int
884 cfparent_match(const device_t parent, const struct cfparent *cfp)
885 {
886 	struct cfdriver *pcd;
887 
888 	/* We don't match root nodes here. */
889 	if (cfp == NULL)
890 		return 0;
891 
892 	pcd = parent->dv_cfdriver;
893 	KASSERT(pcd != NULL);
894 
895 	/*
896 	 * First, ensure this parent has the correct interface
897 	 * attribute.
898 	 */
899 	if (!cfdriver_get_iattr(pcd, cfp->cfp_iattr))
900 		return 0;
901 
902 	/*
903 	 * If no specific parent device instance was specified (i.e.
904 	 * we're attaching to the attribute only), we're done!
905 	 */
906 	if (cfp->cfp_parent == NULL)
907 		return 1;
908 
909 	/*
910 	 * Check the parent device's name.
911 	 */
912 	if (STREQ(pcd->cd_name, cfp->cfp_parent) == 0)
913 		return 0;	/* not the same parent */
914 
915 	/*
916 	 * Make sure the unit number matches.
917 	 */
918 	if (cfp->cfp_unit == DVUNIT_ANY ||	/* wildcard */
919 	    cfp->cfp_unit == parent->dv_unit)
920 		return 1;
921 
922 	/* Unit numbers don't match. */
923 	return 0;
924 }
925 
926 /*
927  * Helper for config_cfdata_attach(): check all devices whether it could be
928  * parent any attachment in the config data table passed, and rescan.
929  */
930 static void
931 rescan_with_cfdata(const struct cfdata *cf)
932 {
933 	device_t d;
934 	const struct cfdata *cf1;
935 	deviter_t di;
936 
937 	KASSERT(KERNEL_LOCKED_P());
938 
939 	/*
940 	 * "alldevs" is likely longer than a modules's cfdata, so make it
941 	 * the outer loop.
942 	 */
943 	for (d = deviter_first(&di, 0); d != NULL; d = deviter_next(&di)) {
944 
945 		if (!(d->dv_cfattach->ca_rescan))
946 			continue;
947 
948 		for (cf1 = cf; cf1->cf_name; cf1++) {
949 
950 			if (!cfparent_match(d, cf1->cf_pspec))
951 				continue;
952 
953 			(*d->dv_cfattach->ca_rescan)(d,
954 				cfdata_ifattr(cf1), cf1->cf_loc);
955 
956 			config_deferred(d);
957 		}
958 	}
959 	deviter_release(&di);
960 }
961 
962 /*
963  * Attach a supplemental config data table and rescan potential
964  * parent devices if required.
965  */
966 int
967 config_cfdata_attach(cfdata_t cf, int scannow)
968 {
969 	struct cftable *ct;
970 
971 	KERNEL_LOCK(1, NULL);
972 
973 	ct = kmem_alloc(sizeof(*ct), KM_SLEEP);
974 	ct->ct_cfdata = cf;
975 	TAILQ_INSERT_TAIL(&allcftables, ct, ct_list);
976 
977 	if (scannow)
978 		rescan_with_cfdata(cf);
979 
980 	KERNEL_UNLOCK_ONE(NULL);
981 
982 	return 0;
983 }
984 
985 /*
986  * Helper for config_cfdata_detach: check whether a device is
987  * found through any attachment in the config data table.
988  */
989 static int
990 dev_in_cfdata(device_t d, cfdata_t cf)
991 {
992 	const struct cfdata *cf1;
993 
994 	for (cf1 = cf; cf1->cf_name; cf1++)
995 		if (d->dv_cfdata == cf1)
996 			return 1;
997 
998 	return 0;
999 }
1000 
1001 /*
1002  * Detach a supplemental config data table. Detach all devices found
1003  * through that table (and thus keeping references to it) before.
1004  */
1005 int
1006 config_cfdata_detach(cfdata_t cf)
1007 {
1008 	device_t d;
1009 	int error = 0;
1010 	struct cftable *ct;
1011 	deviter_t di;
1012 
1013 	KERNEL_LOCK(1, NULL);
1014 
1015 	for (d = deviter_first(&di, DEVITER_F_RW); d != NULL;
1016 	     d = deviter_next(&di)) {
1017 		if (!dev_in_cfdata(d, cf))
1018 			continue;
1019 		if ((error = config_detach(d, 0)) != 0)
1020 			break;
1021 	}
1022 	deviter_release(&di);
1023 	if (error) {
1024 		aprint_error_dev(d, "unable to detach instance\n");
1025 		goto out;
1026 	}
1027 
1028 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
1029 		if (ct->ct_cfdata == cf) {
1030 			TAILQ_REMOVE(&allcftables, ct, ct_list);
1031 			kmem_free(ct, sizeof(*ct));
1032 			error = 0;
1033 			goto out;
1034 		}
1035 	}
1036 
1037 	/* not found -- shouldn't happen */
1038 	error = EINVAL;
1039 
1040 out:	KERNEL_UNLOCK_ONE(NULL);
1041 	return error;
1042 }
1043 
1044 /*
1045  * Invoke the "match" routine for a cfdata entry on behalf of
1046  * an external caller, usually a direct config "submatch" routine.
1047  */
1048 int
1049 config_match(device_t parent, cfdata_t cf, void *aux)
1050 {
1051 	struct cfattach *ca;
1052 
1053 	KASSERT(KERNEL_LOCKED_P());
1054 
1055 	ca = config_cfattach_lookup(cf->cf_name, cf->cf_atname);
1056 	if (ca == NULL) {
1057 		/* No attachment for this entry, oh well. */
1058 		return 0;
1059 	}
1060 
1061 	return (*ca->ca_match)(parent, cf, aux);
1062 }
1063 
1064 /*
1065  * Invoke the "probe" routine for a cfdata entry on behalf of
1066  * an external caller, usually an indirect config "search" routine.
1067  */
1068 int
1069 config_probe(device_t parent, cfdata_t cf, void *aux)
1070 {
1071 	/*
1072 	 * This is currently a synonym for config_match(), but this
1073 	 * is an implementation detail; "match" and "probe" routines
1074 	 * have different behaviors.
1075 	 *
1076 	 * XXX config_probe() should return a bool, because there is
1077 	 * XXX no match score for probe -- it's either there or it's
1078 	 * XXX not, but some ports abuse the return value as a way
1079 	 * XXX to attach "critical" devices before "non-critical"
1080 	 * XXX devices.
1081 	 */
1082 	return config_match(parent, cf, aux);
1083 }
1084 
1085 static struct cfargs_internal *
1086 cfargs_canonicalize(const struct cfargs * const cfargs,
1087     struct cfargs_internal * const store)
1088 {
1089 	struct cfargs_internal *args = store;
1090 
1091 	memset(args, 0, sizeof(*args));
1092 
1093 	/* If none specified, are all-NULL pointers are good. */
1094 	if (cfargs == NULL) {
1095 		return args;
1096 	}
1097 
1098 	/*
1099 	 * Only one arguments version is recognized at this time.
1100 	 */
1101 	if (cfargs->cfargs_version != CFARGS_VERSION) {
1102 		panic("cfargs_canonicalize: unknown version %lu\n",
1103 		    (unsigned long)cfargs->cfargs_version);
1104 	}
1105 
1106 	/*
1107 	 * submatch and search are mutually-exclusive.
1108 	 */
1109 	if (cfargs->submatch != NULL && cfargs->search != NULL) {
1110 		panic("cfargs_canonicalize: submatch and search are "
1111 		      "mutually-exclusive");
1112 	}
1113 	if (cfargs->submatch != NULL) {
1114 		args->submatch = cfargs->submatch;
1115 	} else if (cfargs->search != NULL) {
1116 		args->search = cfargs->search;
1117 	}
1118 
1119 	args->iattr = cfargs->iattr;
1120 	args->locators = cfargs->locators;
1121 	args->devhandle = cfargs->devhandle;
1122 
1123 	return args;
1124 }
1125 
1126 /*
1127  * Iterate over all potential children of some device, calling the given
1128  * function (default being the child's match function) for each one.
1129  * Nonzero returns are matches; the highest value returned is considered
1130  * the best match.  Return the `found child' if we got a match, or NULL
1131  * otherwise.  The `aux' pointer is simply passed on through.
1132  *
1133  * Note that this function is designed so that it can be used to apply
1134  * an arbitrary function to all potential children (its return value
1135  * can be ignored).
1136  */
1137 static cfdata_t
1138 config_search_internal(device_t parent, void *aux,
1139     const struct cfargs_internal * const args)
1140 {
1141 	struct cftable *ct;
1142 	cfdata_t cf;
1143 	struct matchinfo m;
1144 
1145 	KASSERT(config_initialized);
1146 	KASSERTMSG((!args->iattr ||
1147 		cfdriver_get_iattr(parent->dv_cfdriver, args->iattr)),
1148 	    "%s searched for child at interface attribute %s,"
1149 	    " but device %s(4) has no such interface attribute in config(5)",
1150 	    device_xname(parent), args->iattr,
1151 	    parent->dv_cfdriver->cd_name);
1152 	KASSERTMSG((args->iattr ||
1153 		cfdriver_iattr_count(parent->dv_cfdriver) < 2),
1154 	    "%s searched for child without interface attribute,"
1155 	    " needed to disambiguate among the %d declared for in %s(4)"
1156 	    " in config(5)",
1157 	    device_xname(parent),
1158 	    cfdriver_iattr_count(parent->dv_cfdriver),
1159 	    parent->dv_cfdriver->cd_name);
1160 
1161 	m.fn = args->submatch;		/* N.B. union */
1162 	m.parent = parent;
1163 	m.locs = args->locators;
1164 	m.aux = aux;
1165 	m.match = NULL;
1166 	m.pri = 0;
1167 
1168 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
1169 		for (cf = ct->ct_cfdata; cf->cf_name; cf++) {
1170 
1171 			/* We don't match root nodes here. */
1172 			if (!cf->cf_pspec)
1173 				continue;
1174 
1175 			/*
1176 			 * Skip cf if no longer eligible, otherwise scan
1177 			 * through parents for one matching `parent', and
1178 			 * try match function.
1179 			 */
1180 			if (cf->cf_fstate == FSTATE_FOUND)
1181 				continue;
1182 			if (cf->cf_fstate == FSTATE_DNOTFOUND ||
1183 			    cf->cf_fstate == FSTATE_DSTAR)
1184 				continue;
1185 
1186 			/*
1187 			 * If an interface attribute was specified,
1188 			 * consider only children which attach to
1189 			 * that attribute.
1190 			 */
1191 			if (args->iattr != NULL &&
1192 			    !STREQ(args->iattr, cfdata_ifattr(cf)))
1193 				continue;
1194 
1195 			if (cfparent_match(parent, cf->cf_pspec))
1196 				mapply(&m, cf);
1197 		}
1198 	}
1199 	rnd_add_uint32(&rnd_autoconf_source, 0);
1200 	return m.match;
1201 }
1202 
1203 cfdata_t
1204 config_search(device_t parent, void *aux, const struct cfargs *cfargs)
1205 {
1206 	cfdata_t cf;
1207 	struct cfargs_internal store;
1208 
1209 	cf = config_search_internal(parent, aux,
1210 	    cfargs_canonicalize(cfargs, &store));
1211 
1212 	return cf;
1213 }
1214 
1215 /*
1216  * Find the given root device.
1217  * This is much like config_search, but there is no parent.
1218  * Don't bother with multiple cfdata tables; the root node
1219  * must always be in the initial table.
1220  */
1221 cfdata_t
1222 config_rootsearch(cfsubmatch_t fn, const char *rootname, void *aux)
1223 {
1224 	cfdata_t cf;
1225 	const short *p;
1226 	struct matchinfo m;
1227 
1228 	m.fn = fn;
1229 	m.parent = ROOT;
1230 	m.aux = aux;
1231 	m.match = NULL;
1232 	m.pri = 0;
1233 	m.locs = 0;
1234 	/*
1235 	 * Look at root entries for matching name.  We do not bother
1236 	 * with found-state here since only one root should ever be
1237 	 * searched (and it must be done first).
1238 	 */
1239 	for (p = cfroots; *p >= 0; p++) {
1240 		cf = &cfdata[*p];
1241 		if (strcmp(cf->cf_name, rootname) == 0)
1242 			mapply(&m, cf);
1243 	}
1244 	return m.match;
1245 }
1246 
1247 static const char * const msgs[] = {
1248 [QUIET]		=	"",
1249 [UNCONF]	=	" not configured\n",
1250 [UNSUPP]	=	" unsupported\n",
1251 };
1252 
1253 /*
1254  * The given `aux' argument describes a device that has been found
1255  * on the given parent, but not necessarily configured.  Locate the
1256  * configuration data for that device (using the submatch function
1257  * provided, or using candidates' cd_match configuration driver
1258  * functions) and attach it, and return its device_t.  If the device was
1259  * not configured, call the given `print' function and return NULL.
1260  */
1261 device_t
1262 config_found(device_t parent, void *aux, cfprint_t print,
1263     const struct cfargs * const cfargs)
1264 {
1265 	cfdata_t cf;
1266 	struct cfargs_internal store;
1267 	const struct cfargs_internal * const args =
1268 	    cfargs_canonicalize(cfargs, &store);
1269 
1270 	cf = config_search_internal(parent, aux, args);
1271 	if (cf != NULL) {
1272 		return config_attach_internal(parent, cf, aux, print, args);
1273 	}
1274 
1275 	if (print) {
1276 		if (config_do_twiddle && cold)
1277 			twiddle();
1278 
1279 		const int pret = (*print)(aux, device_xname(parent));
1280 		KASSERT(pret >= 0);
1281 		KASSERT(pret < __arraycount(msgs));
1282 		KASSERT(msgs[pret] != NULL);
1283 		aprint_normal("%s", msgs[pret]);
1284 	}
1285 
1286 	return NULL;
1287 }
1288 
1289 /*
1290  * As above, but for root devices.
1291  */
1292 device_t
1293 config_rootfound(const char *rootname, void *aux)
1294 {
1295 	cfdata_t cf;
1296 	device_t dev = NULL;
1297 
1298 	KERNEL_LOCK(1, NULL);
1299 	if ((cf = config_rootsearch(NULL, rootname, aux)) != NULL)
1300 		dev = config_attach(ROOT, cf, aux, NULL, CFARGS_NONE);
1301 	else
1302 		aprint_error("root device %s not configured\n", rootname);
1303 	KERNEL_UNLOCK_ONE(NULL);
1304 	return dev;
1305 }
1306 
1307 /* just like sprintf(buf, "%d") except that it works from the end */
1308 static char *
1309 number(char *ep, int n)
1310 {
1311 
1312 	*--ep = 0;
1313 	while (n >= 10) {
1314 		*--ep = (n % 10) + '0';
1315 		n /= 10;
1316 	}
1317 	*--ep = n + '0';
1318 	return ep;
1319 }
1320 
1321 /*
1322  * Expand the size of the cd_devs array if necessary.
1323  *
1324  * The caller must hold alldevs_lock. config_makeroom() may release and
1325  * re-acquire alldevs_lock, so callers should re-check conditions such
1326  * as alldevs_nwrite == 0 and alldevs_nread == 0 when config_makeroom()
1327  * returns.
1328  */
1329 static void
1330 config_makeroom(int n, struct cfdriver *cd)
1331 {
1332 	int ondevs, nndevs;
1333 	device_t *osp, *nsp;
1334 
1335 	KASSERT(mutex_owned(&alldevs_lock));
1336 	alldevs_nwrite++;
1337 
1338 	for (nndevs = MAX(4, cd->cd_ndevs); nndevs <= n; nndevs += nndevs)
1339 		;
1340 
1341 	while (n >= cd->cd_ndevs) {
1342 		/*
1343 		 * Need to expand the array.
1344 		 */
1345 		ondevs = cd->cd_ndevs;
1346 		osp = cd->cd_devs;
1347 
1348 		/*
1349 		 * Release alldevs_lock around allocation, which may
1350 		 * sleep.
1351 		 */
1352 		mutex_exit(&alldevs_lock);
1353 		nsp = kmem_alloc(sizeof(device_t) * nndevs, KM_SLEEP);
1354 		mutex_enter(&alldevs_lock);
1355 
1356 		/*
1357 		 * If another thread moved the array while we did
1358 		 * not hold alldevs_lock, try again.
1359 		 */
1360 		if (cd->cd_devs != osp || cd->cd_ndevs != ondevs) {
1361 			mutex_exit(&alldevs_lock);
1362 			kmem_free(nsp, sizeof(device_t) * nndevs);
1363 			mutex_enter(&alldevs_lock);
1364 			continue;
1365 		}
1366 
1367 		memset(nsp + ondevs, 0, sizeof(device_t) * (nndevs - ondevs));
1368 		if (ondevs != 0)
1369 			memcpy(nsp, cd->cd_devs, sizeof(device_t) * ondevs);
1370 
1371 		cd->cd_ndevs = nndevs;
1372 		cd->cd_devs = nsp;
1373 		if (ondevs != 0) {
1374 			mutex_exit(&alldevs_lock);
1375 			kmem_free(osp, sizeof(device_t) * ondevs);
1376 			mutex_enter(&alldevs_lock);
1377 		}
1378 	}
1379 	KASSERT(mutex_owned(&alldevs_lock));
1380 	alldevs_nwrite--;
1381 }
1382 
1383 /*
1384  * Put dev into the devices list.
1385  */
1386 static void
1387 config_devlink(device_t dev)
1388 {
1389 
1390 	mutex_enter(&alldevs_lock);
1391 
1392 	KASSERT(device_cfdriver(dev)->cd_devs[dev->dv_unit] == dev);
1393 
1394 	dev->dv_add_gen = alldevs_gen;
1395 	/* It is safe to add a device to the tail of the list while
1396 	 * readers and writers are in the list.
1397 	 */
1398 	TAILQ_INSERT_TAIL(&alldevs, dev, dv_list);
1399 	mutex_exit(&alldevs_lock);
1400 }
1401 
1402 static void
1403 config_devfree(device_t dev)
1404 {
1405 
1406 	KASSERT(dev->dv_flags & DVF_PRIV_ALLOC);
1407 	KASSERTMSG(dev->dv_pending == 0, "%d", dev->dv_pending);
1408 
1409 	if (dev->dv_cfattach->ca_devsize > 0)
1410 		kmem_free(dev->dv_private, dev->dv_cfattach->ca_devsize);
1411 	kmem_free(dev, sizeof(*dev));
1412 }
1413 
1414 /*
1415  * Caller must hold alldevs_lock.
1416  */
1417 static void
1418 config_devunlink(device_t dev, struct devicelist *garbage)
1419 {
1420 	struct device_garbage *dg = &dev->dv_garbage;
1421 	cfdriver_t cd = device_cfdriver(dev);
1422 	int i;
1423 
1424 	KASSERT(mutex_owned(&alldevs_lock));
1425 	KASSERTMSG(dev->dv_pending == 0, "%d", dev->dv_pending);
1426 
1427  	/* Unlink from device list.  Link to garbage list. */
1428 	TAILQ_REMOVE(&alldevs, dev, dv_list);
1429 	TAILQ_INSERT_TAIL(garbage, dev, dv_list);
1430 
1431 	/* Remove from cfdriver's array. */
1432 	cd->cd_devs[dev->dv_unit] = NULL;
1433 
1434 	/*
1435 	 * If the device now has no units in use, unlink its softc array.
1436 	 */
1437 	for (i = 0; i < cd->cd_ndevs; i++) {
1438 		if (cd->cd_devs[i] != NULL)
1439 			break;
1440 	}
1441 	/* Nothing found.  Unlink, now.  Deallocate, later. */
1442 	if (i == cd->cd_ndevs) {
1443 		dg->dg_ndevs = cd->cd_ndevs;
1444 		dg->dg_devs = cd->cd_devs;
1445 		cd->cd_devs = NULL;
1446 		cd->cd_ndevs = 0;
1447 	}
1448 }
1449 
1450 static void
1451 config_devdelete(device_t dev)
1452 {
1453 	struct device_garbage *dg = &dev->dv_garbage;
1454 	device_lock_t dvl = device_getlock(dev);
1455 
1456 	KASSERTMSG(dev->dv_pending == 0, "%d", dev->dv_pending);
1457 
1458 	if (dg->dg_devs != NULL)
1459 		kmem_free(dg->dg_devs, sizeof(device_t) * dg->dg_ndevs);
1460 
1461 	localcount_fini(dev->dv_localcount);
1462 	kmem_free(dev->dv_localcount, sizeof(*dev->dv_localcount));
1463 
1464 	cv_destroy(&dvl->dvl_cv);
1465 	mutex_destroy(&dvl->dvl_mtx);
1466 
1467 	KASSERT(dev->dv_properties != NULL);
1468 	prop_object_release(dev->dv_properties);
1469 
1470 	if (dev->dv_activity_handlers)
1471 		panic("%s with registered handlers", __func__);
1472 
1473 	if (dev->dv_locators) {
1474 		size_t amount = *--dev->dv_locators;
1475 		kmem_free(dev->dv_locators, amount);
1476 	}
1477 
1478 	config_devfree(dev);
1479 }
1480 
1481 static int
1482 config_unit_nextfree(cfdriver_t cd, cfdata_t cf)
1483 {
1484 	int unit = cf->cf_unit;
1485 
1486 	KASSERT(mutex_owned(&alldevs_lock));
1487 
1488 	if (unit < 0)
1489 		return -1;
1490 	if (cf->cf_fstate == FSTATE_STAR) {
1491 		for (; unit < cd->cd_ndevs; unit++)
1492 			if (cd->cd_devs[unit] == NULL)
1493 				break;
1494 		/*
1495 		 * unit is now the unit of the first NULL device pointer,
1496 		 * or max(cd->cd_ndevs,cf->cf_unit).
1497 		 */
1498 	} else {
1499 		if (unit < cd->cd_ndevs && cd->cd_devs[unit] != NULL)
1500 			unit = -1;
1501 	}
1502 	return unit;
1503 }
1504 
1505 static int
1506 config_unit_alloc(device_t dev, cfdriver_t cd, cfdata_t cf)
1507 {
1508 	struct alldevs_foray af;
1509 	int unit;
1510 
1511 	config_alldevs_enter(&af);
1512 	for (;;) {
1513 		unit = config_unit_nextfree(cd, cf);
1514 		if (unit == -1)
1515 			break;
1516 		if (unit < cd->cd_ndevs) {
1517 			cd->cd_devs[unit] = dev;
1518 			dev->dv_unit = unit;
1519 			break;
1520 		}
1521 		config_makeroom(unit, cd);
1522 	}
1523 	config_alldevs_exit(&af);
1524 
1525 	return unit;
1526 }
1527 
1528 static device_t
1529 config_devalloc(const device_t parent, const cfdata_t cf,
1530     const struct cfargs_internal * const args)
1531 {
1532 	cfdriver_t cd;
1533 	cfattach_t ca;
1534 	size_t lname, lunit;
1535 	const char *xunit;
1536 	int myunit;
1537 	char num[10];
1538 	device_t dev;
1539 	void *dev_private;
1540 	const struct cfiattrdata *ia;
1541 	device_lock_t dvl;
1542 
1543 	cd = config_cfdriver_lookup(cf->cf_name);
1544 	if (cd == NULL)
1545 		return NULL;
1546 
1547 	ca = config_cfattach_lookup_cd(cd, cf->cf_atname);
1548 	if (ca == NULL)
1549 		return NULL;
1550 
1551 	/* get memory for all device vars */
1552 	KASSERT(ca->ca_flags & DVF_PRIV_ALLOC);
1553 	if (ca->ca_devsize > 0) {
1554 		dev_private = kmem_zalloc(ca->ca_devsize, KM_SLEEP);
1555 	} else {
1556 		dev_private = NULL;
1557 	}
1558 	dev = kmem_zalloc(sizeof(*dev), KM_SLEEP);
1559 
1560 	dev->dv_handle = args->devhandle;
1561 
1562 	dev->dv_class = cd->cd_class;
1563 	dev->dv_cfdata = cf;
1564 	dev->dv_cfdriver = cd;
1565 	dev->dv_cfattach = ca;
1566 	dev->dv_activity_count = 0;
1567 	dev->dv_activity_handlers = NULL;
1568 	dev->dv_private = dev_private;
1569 	dev->dv_flags = ca->ca_flags;	/* inherit flags from class */
1570 	dev->dv_attaching = curlwp;
1571 
1572 	myunit = config_unit_alloc(dev, cd, cf);
1573 	if (myunit == -1) {
1574 		config_devfree(dev);
1575 		return NULL;
1576 	}
1577 
1578 	/* compute length of name and decimal expansion of unit number */
1579 	lname = strlen(cd->cd_name);
1580 	xunit = number(&num[sizeof(num)], myunit);
1581 	lunit = &num[sizeof(num)] - xunit;
1582 	if (lname + lunit > sizeof(dev->dv_xname))
1583 		panic("config_devalloc: device name too long");
1584 
1585 	dvl = device_getlock(dev);
1586 
1587 	mutex_init(&dvl->dvl_mtx, MUTEX_DEFAULT, IPL_NONE);
1588 	cv_init(&dvl->dvl_cv, "pmfsusp");
1589 
1590 	memcpy(dev->dv_xname, cd->cd_name, lname);
1591 	memcpy(dev->dv_xname + lname, xunit, lunit);
1592 	dev->dv_parent = parent;
1593 	if (parent != NULL)
1594 		dev->dv_depth = parent->dv_depth + 1;
1595 	else
1596 		dev->dv_depth = 0;
1597 	dev->dv_flags |= DVF_ACTIVE;	/* always initially active */
1598 	if (args->locators) {
1599 		KASSERT(parent); /* no locators at root */
1600 		ia = cfiattr_lookup(cfdata_ifattr(cf), parent->dv_cfdriver);
1601 		dev->dv_locators =
1602 		    kmem_alloc(sizeof(int) * (ia->ci_loclen + 1), KM_SLEEP);
1603 		*dev->dv_locators++ = sizeof(int) * (ia->ci_loclen + 1);
1604 		memcpy(dev->dv_locators, args->locators,
1605 		    sizeof(int) * ia->ci_loclen);
1606 	}
1607 	dev->dv_properties = prop_dictionary_create();
1608 	KASSERT(dev->dv_properties != NULL);
1609 
1610 	prop_dictionary_set_string_nocopy(dev->dv_properties,
1611 	    "device-driver", dev->dv_cfdriver->cd_name);
1612 	prop_dictionary_set_uint16(dev->dv_properties,
1613 	    "device-unit", dev->dv_unit);
1614 	if (parent != NULL) {
1615 		prop_dictionary_set_string(dev->dv_properties,
1616 		    "device-parent", device_xname(parent));
1617 	}
1618 
1619 	dev->dv_localcount = kmem_zalloc(sizeof(*dev->dv_localcount),
1620 	    KM_SLEEP);
1621 	localcount_init(dev->dv_localcount);
1622 
1623 	if (dev->dv_cfdriver->cd_attrs != NULL)
1624 		config_add_attrib_dict(dev);
1625 
1626 	return dev;
1627 }
1628 
1629 /*
1630  * Create an array of device attach attributes and add it
1631  * to the device's dv_properties dictionary.
1632  *
1633  * <key>interface-attributes</key>
1634  * <array>
1635  *    <dict>
1636  *       <key>attribute-name</key>
1637  *       <string>foo</string>
1638  *       <key>locators</key>
1639  *       <array>
1640  *          <dict>
1641  *             <key>loc-name</key>
1642  *             <string>foo-loc1</string>
1643  *          </dict>
1644  *          <dict>
1645  *             <key>loc-name</key>
1646  *             <string>foo-loc2</string>
1647  *             <key>default</key>
1648  *             <string>foo-loc2-default</string>
1649  *          </dict>
1650  *          ...
1651  *       </array>
1652  *    </dict>
1653  *    ...
1654  * </array>
1655  */
1656 
1657 static void
1658 config_add_attrib_dict(device_t dev)
1659 {
1660 	int i, j;
1661 	const struct cfiattrdata *ci;
1662 	prop_dictionary_t attr_dict, loc_dict;
1663 	prop_array_t attr_array, loc_array;
1664 
1665 	if ((attr_array = prop_array_create()) == NULL)
1666 		return;
1667 
1668 	for (i = 0; ; i++) {
1669 		if ((ci = dev->dv_cfdriver->cd_attrs[i]) == NULL)
1670 			break;
1671 		if ((attr_dict = prop_dictionary_create()) == NULL)
1672 			break;
1673 		prop_dictionary_set_string_nocopy(attr_dict, "attribute-name",
1674 		    ci->ci_name);
1675 
1676 		/* Create an array of the locator names and defaults */
1677 
1678 		if (ci->ci_loclen != 0 &&
1679 		    (loc_array = prop_array_create()) != NULL) {
1680 			for (j = 0; j < ci->ci_loclen; j++) {
1681 				loc_dict = prop_dictionary_create();
1682 				if (loc_dict == NULL)
1683 					continue;
1684 				prop_dictionary_set_string_nocopy(loc_dict,
1685 				    "loc-name", ci->ci_locdesc[j].cld_name);
1686 				if (ci->ci_locdesc[j].cld_defaultstr != NULL)
1687 					prop_dictionary_set_string_nocopy(
1688 					    loc_dict, "default",
1689 					    ci->ci_locdesc[j].cld_defaultstr);
1690 				prop_array_set(loc_array, j, loc_dict);
1691 				prop_object_release(loc_dict);
1692 			}
1693 			prop_dictionary_set_and_rel(attr_dict, "locators",
1694 			    loc_array);
1695 		}
1696 		prop_array_add(attr_array, attr_dict);
1697 		prop_object_release(attr_dict);
1698 	}
1699 	if (i == 0)
1700 		prop_object_release(attr_array);
1701 	else
1702 		prop_dictionary_set_and_rel(dev->dv_properties,
1703 		    "interface-attributes", attr_array);
1704 
1705 	return;
1706 }
1707 
1708 /*
1709  * Attach a found device.
1710  */
1711 static device_t
1712 config_attach_internal(device_t parent, cfdata_t cf, void *aux, cfprint_t print,
1713     const struct cfargs_internal * const args)
1714 {
1715 	device_t dev;
1716 	struct cftable *ct;
1717 	const char *drvname;
1718 	bool deferred;
1719 
1720 	KASSERT(KERNEL_LOCKED_P());
1721 
1722 	dev = config_devalloc(parent, cf, args);
1723 	if (!dev)
1724 		panic("config_attach: allocation of device softc failed");
1725 
1726 	/* XXX redundant - see below? */
1727 	if (cf->cf_fstate != FSTATE_STAR) {
1728 		KASSERT(cf->cf_fstate == FSTATE_NOTFOUND);
1729 		cf->cf_fstate = FSTATE_FOUND;
1730 	}
1731 
1732 	config_devlink(dev);
1733 
1734 	if (config_do_twiddle && cold)
1735 		twiddle();
1736 	else
1737 		aprint_naive("Found ");
1738 	/*
1739 	 * We want the next two printfs for normal, verbose, and quiet,
1740 	 * but not silent (in which case, we're twiddling, instead).
1741 	 */
1742 	if (parent == ROOT) {
1743 		aprint_naive("%s (root)", device_xname(dev));
1744 		aprint_normal("%s (root)", device_xname(dev));
1745 	} else {
1746 		aprint_naive("%s at %s", device_xname(dev),
1747 		    device_xname(parent));
1748 		aprint_normal("%s at %s", device_xname(dev),
1749 		    device_xname(parent));
1750 		if (print)
1751 			(void) (*print)(aux, NULL);
1752 	}
1753 
1754 	/*
1755 	 * Before attaching, clobber any unfound devices that are
1756 	 * otherwise identical.
1757 	 * XXX code above is redundant?
1758 	 */
1759 	drvname = dev->dv_cfdriver->cd_name;
1760 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
1761 		for (cf = ct->ct_cfdata; cf->cf_name; cf++) {
1762 			if (STREQ(cf->cf_name, drvname) &&
1763 			    cf->cf_unit == dev->dv_unit) {
1764 				if (cf->cf_fstate == FSTATE_NOTFOUND)
1765 					cf->cf_fstate = FSTATE_FOUND;
1766 			}
1767 		}
1768 	}
1769 	device_register(dev, aux);
1770 
1771 	/* Let userland know */
1772 	devmon_report_device(dev, true);
1773 
1774 	/*
1775 	 * Prevent detach until the driver's attach function, and all
1776 	 * deferred actions, have finished.
1777 	 */
1778 	config_pending_incr(dev);
1779 
1780 	/* Call the driver's attach function.  */
1781 	(*dev->dv_cfattach->ca_attach)(parent, dev, aux);
1782 
1783 	/*
1784 	 * Allow other threads to acquire references to the device now
1785 	 * that the driver's attach function is done.
1786 	 */
1787 	mutex_enter(&config_misc_lock);
1788 	KASSERT(dev->dv_attaching == curlwp);
1789 	dev->dv_attaching = NULL;
1790 	cv_broadcast(&config_misc_cv);
1791 	mutex_exit(&config_misc_lock);
1792 
1793 	/*
1794 	 * Synchronous parts of attach are done.  Allow detach, unless
1795 	 * the driver's attach function scheduled deferred actions.
1796 	 */
1797 	config_pending_decr(dev);
1798 
1799 	mutex_enter(&config_misc_lock);
1800 	deferred = (dev->dv_pending != 0);
1801 	mutex_exit(&config_misc_lock);
1802 
1803 	if (!deferred && !device_pmf_is_registered(dev))
1804 		aprint_debug_dev(dev,
1805 		    "WARNING: power management not supported\n");
1806 
1807 	config_process_deferred(&deferred_config_queue, dev);
1808 
1809 	device_register_post_config(dev, aux);
1810 	rnd_add_uint32(&rnd_autoconf_source, 0);
1811 	return dev;
1812 }
1813 
1814 device_t
1815 config_attach(device_t parent, cfdata_t cf, void *aux, cfprint_t print,
1816     const struct cfargs *cfargs)
1817 {
1818 	struct cfargs_internal store;
1819 
1820 	KASSERT(KERNEL_LOCKED_P());
1821 
1822 	return config_attach_internal(parent, cf, aux, print,
1823 	    cfargs_canonicalize(cfargs, &store));
1824 }
1825 
1826 /*
1827  * As above, but for pseudo-devices.  Pseudo-devices attached in this
1828  * way are silently inserted into the device tree, and their children
1829  * attached.
1830  *
1831  * Note that because pseudo-devices are attached silently, any information
1832  * the attach routine wishes to print should be prefixed with the device
1833  * name by the attach routine.
1834  */
1835 device_t
1836 config_attach_pseudo(cfdata_t cf)
1837 {
1838 	device_t dev;
1839 
1840 	KERNEL_LOCK(1, NULL);
1841 
1842 	struct cfargs_internal args = { };
1843 	dev = config_devalloc(ROOT, cf, &args);
1844 	if (!dev)
1845 		goto out;
1846 
1847 	/* XXX mark busy in cfdata */
1848 
1849 	if (cf->cf_fstate != FSTATE_STAR) {
1850 		KASSERT(cf->cf_fstate == FSTATE_NOTFOUND);
1851 		cf->cf_fstate = FSTATE_FOUND;
1852 	}
1853 
1854 	config_devlink(dev);
1855 
1856 #if 0	/* XXXJRT not yet */
1857 	device_register(dev, NULL);	/* like a root node */
1858 #endif
1859 
1860 	/* Let userland know */
1861 	devmon_report_device(dev, true);
1862 
1863 	/*
1864 	 * Prevent detach until the driver's attach function, and all
1865 	 * deferred actions, have finished.
1866 	 */
1867 	config_pending_incr(dev);
1868 
1869 	/* Call the driver's attach function.  */
1870 	(*dev->dv_cfattach->ca_attach)(ROOT, dev, NULL);
1871 
1872 	/*
1873 	 * Allow other threads to acquire references to the device now
1874 	 * that the driver's attach function is done.
1875 	 */
1876 	mutex_enter(&config_misc_lock);
1877 	KASSERT(dev->dv_attaching == curlwp);
1878 	dev->dv_attaching = NULL;
1879 	cv_broadcast(&config_misc_cv);
1880 	mutex_exit(&config_misc_lock);
1881 
1882 	/*
1883 	 * Synchronous parts of attach are done.  Allow detach, unless
1884 	 * the driver's attach function scheduled deferred actions.
1885 	 */
1886 	config_pending_decr(dev);
1887 
1888 	config_process_deferred(&deferred_config_queue, dev);
1889 
1890 out:	KERNEL_UNLOCK_ONE(NULL);
1891 	return dev;
1892 }
1893 
1894 /*
1895  * Caller must hold alldevs_lock.
1896  */
1897 static void
1898 config_collect_garbage(struct devicelist *garbage)
1899 {
1900 	device_t dv;
1901 
1902 	KASSERT(!cpu_intr_p());
1903 	KASSERT(!cpu_softintr_p());
1904 	KASSERT(mutex_owned(&alldevs_lock));
1905 
1906 	while (alldevs_nwrite == 0 && alldevs_nread == 0 && alldevs_garbage) {
1907 		TAILQ_FOREACH(dv, &alldevs, dv_list) {
1908 			if (dv->dv_del_gen != 0)
1909 				break;
1910 		}
1911 		if (dv == NULL) {
1912 			alldevs_garbage = false;
1913 			break;
1914 		}
1915 		config_devunlink(dv, garbage);
1916 	}
1917 	KASSERT(mutex_owned(&alldevs_lock));
1918 }
1919 
1920 static void
1921 config_dump_garbage(struct devicelist *garbage)
1922 {
1923 	device_t dv;
1924 
1925 	while ((dv = TAILQ_FIRST(garbage)) != NULL) {
1926 		TAILQ_REMOVE(garbage, dv, dv_list);
1927 		config_devdelete(dv);
1928 	}
1929 }
1930 
1931 static int
1932 config_detach_enter(device_t dev)
1933 {
1934 	struct lwp *l __diagused;
1935 	int error = 0;
1936 
1937 	mutex_enter(&config_misc_lock);
1938 
1939 	/*
1940 	 * Wait until attach has fully completed, and until any
1941 	 * concurrent detach (e.g., drvctl racing with USB event
1942 	 * thread) has completed.
1943 	 *
1944 	 * Caller must hold alldevs_nread or alldevs_nwrite (e.g., via
1945 	 * deviter) to ensure the winner of the race doesn't free the
1946 	 * device leading the loser of the race into use-after-free.
1947 	 *
1948 	 * XXX Not all callers do this!
1949 	 */
1950 	while (dev->dv_pending || dev->dv_detaching) {
1951 		KASSERTMSG(dev->dv_detaching != curlwp,
1952 		    "recursively detaching %s", device_xname(dev));
1953 		error = cv_wait_sig(&config_misc_cv, &config_misc_lock);
1954 		if (error)
1955 			goto out;
1956 	}
1957 
1958 	/*
1959 	 * Attach has completed, and no other concurrent detach is
1960 	 * running.  Claim the device for detaching.  This will cause
1961 	 * all new attempts to acquire references to block.
1962 	 */
1963 	KASSERTMSG((l = dev->dv_attaching) == NULL,
1964 	    "lwp %ld [%s] @ %p attaching %s",
1965 	    (long)l->l_lid, (l->l_name ? l->l_name : l->l_proc->p_comm), l,
1966 	    device_xname(dev));
1967 	KASSERTMSG((l = dev->dv_detaching) == NULL,
1968 	    "lwp %ld [%s] @ %p detaching %s",
1969 	    (long)l->l_lid, (l->l_name ? l->l_name : l->l_proc->p_comm), l,
1970 	    device_xname(dev));
1971 	dev->dv_detaching = curlwp;
1972 
1973 out:	mutex_exit(&config_misc_lock);
1974 	return error;
1975 }
1976 
1977 static void
1978 config_detach_exit(device_t dev)
1979 {
1980 	struct lwp *l __diagused;
1981 
1982 	mutex_enter(&config_misc_lock);
1983 	KASSERTMSG(dev->dv_detaching != NULL, "not detaching %s",
1984 	    device_xname(dev));
1985 	KASSERTMSG((l = dev->dv_detaching) == curlwp,
1986 	    "lwp %ld [%s] @ %p detaching %s",
1987 	    (long)l->l_lid, (l->l_name ? l->l_name : l->l_proc->p_comm), l,
1988 	    device_xname(dev));
1989 	dev->dv_detaching = NULL;
1990 	cv_broadcast(&config_misc_cv);
1991 	mutex_exit(&config_misc_lock);
1992 }
1993 
1994 /*
1995  * Detach a device.  Optionally forced (e.g. because of hardware
1996  * removal) and quiet.  Returns zero if successful, non-zero
1997  * (an error code) otherwise.
1998  *
1999  * Note that this code wants to be run from a process context, so
2000  * that the detach can sleep to allow processes which have a device
2001  * open to run and unwind their stacks.
2002  */
2003 int
2004 config_detach(device_t dev, int flags)
2005 {
2006 	struct alldevs_foray af;
2007 	struct cftable *ct;
2008 	cfdata_t cf;
2009 	const struct cfattach *ca;
2010 	struct cfdriver *cd;
2011 	device_t d __diagused;
2012 	int rv = 0;
2013 
2014 	KERNEL_LOCK(1, NULL);
2015 
2016 	cf = dev->dv_cfdata;
2017 	KASSERTMSG((cf == NULL || cf->cf_fstate == FSTATE_FOUND ||
2018 		cf->cf_fstate == FSTATE_STAR),
2019 	    "config_detach: %s: bad device fstate: %d",
2020 	    device_xname(dev), cf ? cf->cf_fstate : -1);
2021 
2022 	cd = dev->dv_cfdriver;
2023 	KASSERT(cd != NULL);
2024 
2025 	ca = dev->dv_cfattach;
2026 	KASSERT(ca != NULL);
2027 
2028 	/*
2029 	 * Only one detach at a time, please -- and not until fully
2030 	 * attached.
2031 	 */
2032 	rv = config_detach_enter(dev);
2033 	if (rv) {
2034 		KERNEL_UNLOCK_ONE(NULL);
2035 		return rv;
2036 	}
2037 
2038 	mutex_enter(&alldevs_lock);
2039 	if (dev->dv_del_gen != 0) {
2040 		mutex_exit(&alldevs_lock);
2041 #ifdef DIAGNOSTIC
2042 		printf("%s: %s is already detached\n", __func__,
2043 		    device_xname(dev));
2044 #endif /* DIAGNOSTIC */
2045 		config_detach_exit(dev);
2046 		KERNEL_UNLOCK_ONE(NULL);
2047 		return ENOENT;
2048 	}
2049 	alldevs_nwrite++;
2050 	mutex_exit(&alldevs_lock);
2051 
2052 	/*
2053 	 * Call the driver's .ca_detach function, unless it has none or
2054 	 * we are skipping it because it's unforced shutdown time and
2055 	 * the driver didn't ask to detach on shutdown.
2056 	 */
2057 	if (!detachall &&
2058 	    (flags & (DETACH_SHUTDOWN|DETACH_FORCE)) == DETACH_SHUTDOWN &&
2059 	    (dev->dv_flags & DVF_DETACH_SHUTDOWN) == 0) {
2060 		rv = EOPNOTSUPP;
2061 	} else if (ca->ca_detach != NULL) {
2062 		rv = (*ca->ca_detach)(dev, flags);
2063 	} else
2064 		rv = EOPNOTSUPP;
2065 
2066 	KASSERTMSG(!dev->dv_detach_done, "%s detached twice, error=%d",
2067 	    device_xname(dev), rv);
2068 
2069 	/*
2070 	 * If it was not possible to detach the device, then we either
2071 	 * panic() (for the forced but failed case), or return an error.
2072 	 */
2073 	if (rv) {
2074 		/*
2075 		 * Detach failed -- likely EOPNOTSUPP or EBUSY.  Driver
2076 		 * must not have called config_detach_commit.
2077 		 */
2078 		KASSERTMSG(!dev->dv_detach_committed,
2079 		    "%s committed to detaching and then backed out, error=%d",
2080 		    device_xname(dev), rv);
2081 		if (flags & DETACH_FORCE) {
2082 			panic("config_detach: forced detach of %s failed (%d)",
2083 			    device_xname(dev), rv);
2084 		}
2085 		goto out;
2086 	}
2087 
2088 	/*
2089 	 * The device has now been successfully detached.
2090 	 */
2091 	dev->dv_detach_done = true;
2092 
2093 	/*
2094 	 * If .ca_detach didn't commit to detach, then do that for it.
2095 	 * This wakes any pending device_lookup_acquire calls so they
2096 	 * will fail.
2097 	 */
2098 	config_detach_commit(dev);
2099 
2100 	/*
2101 	 * If it was possible to detach the device, ensure that the
2102 	 * device is deactivated.
2103 	 */
2104 	dev->dv_flags &= ~DVF_ACTIVE; /* XXXSMP */
2105 
2106 	/*
2107 	 * Wait for all device_lookup_acquire references -- mostly, for
2108 	 * all attempts to open the device -- to drain.  It is the
2109 	 * responsibility of .ca_detach to ensure anything with open
2110 	 * references will be interrupted and release them promptly,
2111 	 * not block indefinitely.  All new attempts to acquire
2112 	 * references will fail, as config_detach_commit has arranged
2113 	 * by now.
2114 	 */
2115 	mutex_enter(&config_misc_lock);
2116 	localcount_drain(dev->dv_localcount,
2117 	    &config_misc_cv, &config_misc_lock);
2118 	mutex_exit(&config_misc_lock);
2119 
2120 	/* Let userland know */
2121 	devmon_report_device(dev, false);
2122 
2123 #ifdef DIAGNOSTIC
2124 	/*
2125 	 * Sanity: If you're successfully detached, you should have no
2126 	 * children.  (Note that because children must be attached
2127 	 * after parents, we only need to search the latter part of
2128 	 * the list.)
2129 	 */
2130 	mutex_enter(&alldevs_lock);
2131 	for (d = TAILQ_NEXT(dev, dv_list); d != NULL;
2132 	    d = TAILQ_NEXT(d, dv_list)) {
2133 		if (d->dv_parent == dev && d->dv_del_gen == 0) {
2134 			printf("config_detach: detached device %s"
2135 			    " has children %s\n", device_xname(dev),
2136 			    device_xname(d));
2137 			panic("config_detach");
2138 		}
2139 	}
2140 	mutex_exit(&alldevs_lock);
2141 #endif
2142 
2143 	/* notify the parent that the child is gone */
2144 	if (dev->dv_parent) {
2145 		device_t p = dev->dv_parent;
2146 		if (p->dv_cfattach->ca_childdetached)
2147 			(*p->dv_cfattach->ca_childdetached)(p, dev);
2148 	}
2149 
2150 	/*
2151 	 * Mark cfdata to show that the unit can be reused, if possible.
2152 	 */
2153 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
2154 		for (cf = ct->ct_cfdata; cf->cf_name; cf++) {
2155 			if (STREQ(cf->cf_name, cd->cd_name)) {
2156 				if (cf->cf_fstate == FSTATE_FOUND &&
2157 				    cf->cf_unit == dev->dv_unit)
2158 					cf->cf_fstate = FSTATE_NOTFOUND;
2159 			}
2160 		}
2161 	}
2162 
2163 	if (dev->dv_cfdata != NULL && (flags & DETACH_QUIET) == 0)
2164 		aprint_normal_dev(dev, "detached\n");
2165 
2166 out:
2167 	config_detach_exit(dev);
2168 
2169 	config_alldevs_enter(&af);
2170 	KASSERT(alldevs_nwrite != 0);
2171 	--alldevs_nwrite;
2172 	if (rv == 0 && dev->dv_del_gen == 0) {
2173 		if (alldevs_nwrite == 0 && alldevs_nread == 0)
2174 			config_devunlink(dev, &af.af_garbage);
2175 		else {
2176 			dev->dv_del_gen = alldevs_gen;
2177 			alldevs_garbage = true;
2178 		}
2179 	}
2180 	config_alldevs_exit(&af);
2181 
2182 	KERNEL_UNLOCK_ONE(NULL);
2183 
2184 	return rv;
2185 }
2186 
2187 /*
2188  * config_detach_commit(dev)
2189  *
2190  *	Issued by a driver's .ca_detach routine to notify anyone
2191  *	waiting in device_lookup_acquire that the driver is committed
2192  *	to detaching the device, which allows device_lookup_acquire to
2193  *	wake up and fail immediately.
2194  *
2195  *	Safe to call multiple times -- idempotent.  Must be called
2196  *	during config_detach_enter/exit.  Safe to use with
2197  *	device_lookup because the device is not actually removed from
2198  *	the table until after config_detach_exit.
2199  */
2200 void
2201 config_detach_commit(device_t dev)
2202 {
2203 	struct lwp *l __diagused;
2204 
2205 	mutex_enter(&config_misc_lock);
2206 	KASSERTMSG(dev->dv_detaching != NULL, "not detaching %s",
2207 	    device_xname(dev));
2208 	KASSERTMSG((l = dev->dv_detaching) == curlwp,
2209 	    "lwp %ld [%s] @ %p detaching %s",
2210 	    (long)l->l_lid, (l->l_name ? l->l_name : l->l_proc->p_comm), l,
2211 	    device_xname(dev));
2212 	dev->dv_detach_committed = true;
2213 	cv_broadcast(&config_misc_cv);
2214 	mutex_exit(&config_misc_lock);
2215 }
2216 
2217 int
2218 config_detach_children(device_t parent, int flags)
2219 {
2220 	device_t dv;
2221 	deviter_t di;
2222 	int error = 0;
2223 
2224 	KASSERT(KERNEL_LOCKED_P());
2225 
2226 	for (dv = deviter_first(&di, DEVITER_F_RW); dv != NULL;
2227 	     dv = deviter_next(&di)) {
2228 		if (device_parent(dv) != parent)
2229 			continue;
2230 		if ((error = config_detach(dv, flags)) != 0)
2231 			break;
2232 	}
2233 	deviter_release(&di);
2234 	return error;
2235 }
2236 
2237 device_t
2238 shutdown_first(struct shutdown_state *s)
2239 {
2240 	if (!s->initialized) {
2241 		deviter_init(&s->di, DEVITER_F_SHUTDOWN|DEVITER_F_LEAVES_FIRST);
2242 		s->initialized = true;
2243 	}
2244 	return shutdown_next(s);
2245 }
2246 
2247 device_t
2248 shutdown_next(struct shutdown_state *s)
2249 {
2250 	device_t dv;
2251 
2252 	while ((dv = deviter_next(&s->di)) != NULL && !device_is_active(dv))
2253 		;
2254 
2255 	if (dv == NULL)
2256 		s->initialized = false;
2257 
2258 	return dv;
2259 }
2260 
2261 bool
2262 config_detach_all(int how)
2263 {
2264 	static struct shutdown_state s;
2265 	device_t curdev;
2266 	bool progress = false;
2267 	int flags;
2268 
2269 	KERNEL_LOCK(1, NULL);
2270 
2271 	if ((how & (RB_NOSYNC|RB_DUMP)) != 0)
2272 		goto out;
2273 
2274 	if ((how & RB_POWERDOWN) == RB_POWERDOWN)
2275 		flags = DETACH_SHUTDOWN | DETACH_POWEROFF;
2276 	else
2277 		flags = DETACH_SHUTDOWN;
2278 
2279 	for (curdev = shutdown_first(&s); curdev != NULL;
2280 	     curdev = shutdown_next(&s)) {
2281 		aprint_debug(" detaching %s, ", device_xname(curdev));
2282 		if (config_detach(curdev, flags) == 0) {
2283 			progress = true;
2284 			aprint_debug("success.");
2285 		} else
2286 			aprint_debug("failed.");
2287 	}
2288 
2289 out:	KERNEL_UNLOCK_ONE(NULL);
2290 	return progress;
2291 }
2292 
2293 static bool
2294 device_is_ancestor_of(device_t ancestor, device_t descendant)
2295 {
2296 	device_t dv;
2297 
2298 	for (dv = descendant; dv != NULL; dv = device_parent(dv)) {
2299 		if (device_parent(dv) == ancestor)
2300 			return true;
2301 	}
2302 	return false;
2303 }
2304 
2305 int
2306 config_deactivate(device_t dev)
2307 {
2308 	deviter_t di;
2309 	const struct cfattach *ca;
2310 	device_t descendant;
2311 	int s, rv = 0, oflags;
2312 
2313 	for (descendant = deviter_first(&di, DEVITER_F_ROOT_FIRST);
2314 	     descendant != NULL;
2315 	     descendant = deviter_next(&di)) {
2316 		if (dev != descendant &&
2317 		    !device_is_ancestor_of(dev, descendant))
2318 			continue;
2319 
2320 		if ((descendant->dv_flags & DVF_ACTIVE) == 0)
2321 			continue;
2322 
2323 		ca = descendant->dv_cfattach;
2324 		oflags = descendant->dv_flags;
2325 
2326 		descendant->dv_flags &= ~DVF_ACTIVE;
2327 		if (ca->ca_activate == NULL)
2328 			continue;
2329 		s = splhigh();
2330 		rv = (*ca->ca_activate)(descendant, DVACT_DEACTIVATE);
2331 		splx(s);
2332 		if (rv != 0)
2333 			descendant->dv_flags = oflags;
2334 	}
2335 	deviter_release(&di);
2336 	return rv;
2337 }
2338 
2339 /*
2340  * Defer the configuration of the specified device until all
2341  * of its parent's devices have been attached.
2342  */
2343 void
2344 config_defer(device_t dev, void (*func)(device_t))
2345 {
2346 	struct deferred_config *dc;
2347 
2348 	if (dev->dv_parent == NULL)
2349 		panic("config_defer: can't defer config of a root device");
2350 
2351 	dc = kmem_alloc(sizeof(*dc), KM_SLEEP);
2352 
2353 	config_pending_incr(dev);
2354 
2355 	mutex_enter(&config_misc_lock);
2356 #ifdef DIAGNOSTIC
2357 	struct deferred_config *odc;
2358 	TAILQ_FOREACH(odc, &deferred_config_queue, dc_queue) {
2359 		if (odc->dc_dev == dev)
2360 			panic("config_defer: deferred twice");
2361 	}
2362 #endif
2363 	dc->dc_dev = dev;
2364 	dc->dc_func = func;
2365 	TAILQ_INSERT_TAIL(&deferred_config_queue, dc, dc_queue);
2366 	mutex_exit(&config_misc_lock);
2367 }
2368 
2369 /*
2370  * Defer some autoconfiguration for a device until after interrupts
2371  * are enabled.
2372  */
2373 void
2374 config_interrupts(device_t dev, void (*func)(device_t))
2375 {
2376 	struct deferred_config *dc;
2377 
2378 	/*
2379 	 * If interrupts are enabled, callback now.
2380 	 */
2381 	if (cold == 0) {
2382 		(*func)(dev);
2383 		return;
2384 	}
2385 
2386 	dc = kmem_alloc(sizeof(*dc), KM_SLEEP);
2387 
2388 	config_pending_incr(dev);
2389 
2390 	mutex_enter(&config_misc_lock);
2391 #ifdef DIAGNOSTIC
2392 	struct deferred_config *odc;
2393 	TAILQ_FOREACH(odc, &interrupt_config_queue, dc_queue) {
2394 		if (odc->dc_dev == dev)
2395 			panic("config_interrupts: deferred twice");
2396 	}
2397 #endif
2398 	dc->dc_dev = dev;
2399 	dc->dc_func = func;
2400 	TAILQ_INSERT_TAIL(&interrupt_config_queue, dc, dc_queue);
2401 	mutex_exit(&config_misc_lock);
2402 }
2403 
2404 /*
2405  * Defer some autoconfiguration for a device until after root file system
2406  * is mounted (to load firmware etc).
2407  */
2408 void
2409 config_mountroot(device_t dev, void (*func)(device_t))
2410 {
2411 	struct deferred_config *dc;
2412 
2413 	/*
2414 	 * If root file system is mounted, callback now.
2415 	 */
2416 	if (root_is_mounted) {
2417 		(*func)(dev);
2418 		return;
2419 	}
2420 
2421 	dc = kmem_alloc(sizeof(*dc), KM_SLEEP);
2422 
2423 	mutex_enter(&config_misc_lock);
2424 #ifdef DIAGNOSTIC
2425 	struct deferred_config *odc;
2426 	TAILQ_FOREACH(odc, &mountroot_config_queue, dc_queue) {
2427 		if (odc->dc_dev == dev)
2428 			panic("%s: deferred twice", __func__);
2429 	}
2430 #endif
2431 
2432 	dc->dc_dev = dev;
2433 	dc->dc_func = func;
2434 	TAILQ_INSERT_TAIL(&mountroot_config_queue, dc, dc_queue);
2435 	mutex_exit(&config_misc_lock);
2436 }
2437 
2438 /*
2439  * Process a deferred configuration queue.
2440  */
2441 static void
2442 config_process_deferred(struct deferred_config_head *queue, device_t parent)
2443 {
2444 	struct deferred_config *dc;
2445 
2446 	KASSERT(KERNEL_LOCKED_P());
2447 
2448 	mutex_enter(&config_misc_lock);
2449 	dc = TAILQ_FIRST(queue);
2450 	while (dc) {
2451 		if (parent == NULL || dc->dc_dev->dv_parent == parent) {
2452 			TAILQ_REMOVE(queue, dc, dc_queue);
2453 			mutex_exit(&config_misc_lock);
2454 
2455 			(*dc->dc_func)(dc->dc_dev);
2456 			config_pending_decr(dc->dc_dev);
2457 			kmem_free(dc, sizeof(*dc));
2458 
2459 			mutex_enter(&config_misc_lock);
2460 			/* Restart, queue might have changed */
2461 			dc = TAILQ_FIRST(queue);
2462 		} else {
2463 			dc = TAILQ_NEXT(dc, dc_queue);
2464 		}
2465 	}
2466 	mutex_exit(&config_misc_lock);
2467 }
2468 
2469 /*
2470  * Manipulate the config_pending semaphore.
2471  */
2472 void
2473 config_pending_incr(device_t dev)
2474 {
2475 
2476 	mutex_enter(&config_misc_lock);
2477 	KASSERTMSG(dev->dv_pending < INT_MAX,
2478 	    "%s: excess config_pending_incr", device_xname(dev));
2479 	if (dev->dv_pending++ == 0)
2480 		TAILQ_INSERT_TAIL(&config_pending, dev, dv_pending_list);
2481 #ifdef DEBUG_AUTOCONF
2482 	printf("%s: %s %d\n", __func__, device_xname(dev), dev->dv_pending);
2483 #endif
2484 	mutex_exit(&config_misc_lock);
2485 }
2486 
2487 void
2488 config_pending_decr(device_t dev)
2489 {
2490 
2491 	mutex_enter(&config_misc_lock);
2492 	KASSERTMSG(dev->dv_pending > 0,
2493 	    "%s: excess config_pending_decr", device_xname(dev));
2494 	if (--dev->dv_pending == 0) {
2495 		TAILQ_REMOVE(&config_pending, dev, dv_pending_list);
2496 		cv_broadcast(&config_misc_cv);
2497 	}
2498 #ifdef DEBUG_AUTOCONF
2499 	printf("%s: %s %d\n", __func__, device_xname(dev), dev->dv_pending);
2500 #endif
2501 	mutex_exit(&config_misc_lock);
2502 }
2503 
2504 /*
2505  * Register a "finalization" routine.  Finalization routines are
2506  * called iteratively once all real devices have been found during
2507  * autoconfiguration, for as long as any one finalizer has done
2508  * any work.
2509  */
2510 int
2511 config_finalize_register(device_t dev, int (*fn)(device_t))
2512 {
2513 	struct finalize_hook *f;
2514 	int error = 0;
2515 
2516 	KERNEL_LOCK(1, NULL);
2517 
2518 	/*
2519 	 * If finalization has already been done, invoke the
2520 	 * callback function now.
2521 	 */
2522 	if (config_finalize_done) {
2523 		while ((*fn)(dev) != 0)
2524 			/* loop */ ;
2525 		goto out;
2526 	}
2527 
2528 	/* Ensure this isn't already on the list. */
2529 	TAILQ_FOREACH(f, &config_finalize_list, f_list) {
2530 		if (f->f_func == fn && f->f_dev == dev) {
2531 			error = EEXIST;
2532 			goto out;
2533 		}
2534 	}
2535 
2536 	f = kmem_alloc(sizeof(*f), KM_SLEEP);
2537 	f->f_func = fn;
2538 	f->f_dev = dev;
2539 	TAILQ_INSERT_TAIL(&config_finalize_list, f, f_list);
2540 
2541 	/* Success!  */
2542 	error = 0;
2543 
2544 out:	KERNEL_UNLOCK_ONE(NULL);
2545 	return error;
2546 }
2547 
2548 void
2549 config_finalize(void)
2550 {
2551 	struct finalize_hook *f;
2552 	struct pdevinit *pdev;
2553 	extern struct pdevinit pdevinit[];
2554 	int errcnt, rv;
2555 
2556 	/*
2557 	 * Now that device driver threads have been created, wait for
2558 	 * them to finish any deferred autoconfiguration.
2559 	 */
2560 	mutex_enter(&config_misc_lock);
2561 	while (!TAILQ_EMPTY(&config_pending)) {
2562 		device_t dev;
2563 		int error;
2564 
2565 		error = cv_timedwait(&config_misc_cv, &config_misc_lock,
2566 		    mstohz(1000));
2567 		if (error == EWOULDBLOCK) {
2568 			aprint_debug("waiting for devices:");
2569 			TAILQ_FOREACH(dev, &config_pending, dv_pending_list)
2570 				aprint_debug(" %s", device_xname(dev));
2571 			aprint_debug("\n");
2572 		}
2573 	}
2574 	mutex_exit(&config_misc_lock);
2575 
2576 	KERNEL_LOCK(1, NULL);
2577 
2578 	/* Attach pseudo-devices. */
2579 	for (pdev = pdevinit; pdev->pdev_attach != NULL; pdev++)
2580 		(*pdev->pdev_attach)(pdev->pdev_count);
2581 
2582 	/* Run the hooks until none of them does any work. */
2583 	do {
2584 		rv = 0;
2585 		TAILQ_FOREACH(f, &config_finalize_list, f_list)
2586 			rv |= (*f->f_func)(f->f_dev);
2587 	} while (rv != 0);
2588 
2589 	config_finalize_done = 1;
2590 
2591 	/* Now free all the hooks. */
2592 	while ((f = TAILQ_FIRST(&config_finalize_list)) != NULL) {
2593 		TAILQ_REMOVE(&config_finalize_list, f, f_list);
2594 		kmem_free(f, sizeof(*f));
2595 	}
2596 
2597 	KERNEL_UNLOCK_ONE(NULL);
2598 
2599 	errcnt = aprint_get_error_count();
2600 	if ((boothowto & (AB_QUIET|AB_SILENT)) != 0 &&
2601 	    (boothowto & AB_VERBOSE) == 0) {
2602 		mutex_enter(&config_misc_lock);
2603 		if (config_do_twiddle) {
2604 			config_do_twiddle = 0;
2605 			printf_nolog(" done.\n");
2606 		}
2607 		mutex_exit(&config_misc_lock);
2608 	}
2609 	if (errcnt != 0) {
2610 		printf("WARNING: %d error%s while detecting hardware; "
2611 		    "check system log.\n", errcnt,
2612 		    errcnt == 1 ? "" : "s");
2613 	}
2614 }
2615 
2616 void
2617 config_twiddle_init(void)
2618 {
2619 
2620 	if ((boothowto & (AB_SILENT|AB_VERBOSE)) == AB_SILENT) {
2621 		config_do_twiddle = 1;
2622 	}
2623 	callout_setfunc(&config_twiddle_ch, config_twiddle_fn, NULL);
2624 }
2625 
2626 void
2627 config_twiddle_fn(void *cookie)
2628 {
2629 
2630 	mutex_enter(&config_misc_lock);
2631 	if (config_do_twiddle) {
2632 		twiddle();
2633 		callout_schedule(&config_twiddle_ch, mstohz(100));
2634 	}
2635 	mutex_exit(&config_misc_lock);
2636 }
2637 
2638 static void
2639 config_alldevs_enter(struct alldevs_foray *af)
2640 {
2641 	TAILQ_INIT(&af->af_garbage);
2642 	mutex_enter(&alldevs_lock);
2643 	config_collect_garbage(&af->af_garbage);
2644 }
2645 
2646 static void
2647 config_alldevs_exit(struct alldevs_foray *af)
2648 {
2649 	mutex_exit(&alldevs_lock);
2650 	config_dump_garbage(&af->af_garbage);
2651 }
2652 
2653 /*
2654  * device_lookup:
2655  *
2656  *	Look up a device instance for a given driver.
2657  *
2658  *	Caller is responsible for ensuring the device's state is
2659  *	stable, either by holding a reference already obtained with
2660  *	device_lookup_acquire or by otherwise ensuring the device is
2661  *	attached and can't be detached (e.g., holding an open device
2662  *	node and ensuring *_detach calls vdevgone).
2663  *
2664  *	XXX Find a way to assert this.
2665  *
2666  *	Safe for use up to and including interrupt context at IPL_VM.
2667  *	Never sleeps.
2668  */
2669 device_t
2670 device_lookup(cfdriver_t cd, int unit)
2671 {
2672 	device_t dv;
2673 
2674 	mutex_enter(&alldevs_lock);
2675 	if (unit < 0 || unit >= cd->cd_ndevs)
2676 		dv = NULL;
2677 	else if ((dv = cd->cd_devs[unit]) != NULL && dv->dv_del_gen != 0)
2678 		dv = NULL;
2679 	mutex_exit(&alldevs_lock);
2680 
2681 	return dv;
2682 }
2683 
2684 /*
2685  * device_lookup_private:
2686  *
2687  *	Look up a softc instance for a given driver.
2688  */
2689 void *
2690 device_lookup_private(cfdriver_t cd, int unit)
2691 {
2692 
2693 	return device_private(device_lookup(cd, unit));
2694 }
2695 
2696 /*
2697  * device_lookup_acquire:
2698  *
2699  *	Look up a device instance for a given driver, and return a
2700  *	reference to it that must be released by device_release.
2701  *
2702  *	=> If the device is still attaching, blocks until *_attach has
2703  *	   returned.
2704  *
2705  *	=> If the device is detaching, blocks until *_detach has
2706  *	   returned.  May succeed or fail in that case, depending on
2707  *	   whether *_detach has backed out (EBUSY) or committed to
2708  *	   detaching.
2709  *
2710  *	May sleep.
2711  */
2712 device_t
2713 device_lookup_acquire(cfdriver_t cd, int unit)
2714 {
2715 	device_t dv;
2716 
2717 	ASSERT_SLEEPABLE();
2718 
2719 	/* XXX This should have a pserialized fast path -- TBD.  */
2720 	mutex_enter(&config_misc_lock);
2721 	mutex_enter(&alldevs_lock);
2722 retry:	if (unit < 0 || unit >= cd->cd_ndevs ||
2723 	    (dv = cd->cd_devs[unit]) == NULL ||
2724 	    dv->dv_del_gen != 0 ||
2725 	    dv->dv_detach_committed) {
2726 		dv = NULL;
2727 	} else {
2728 		/*
2729 		 * Wait for the device to stabilize, if attaching or
2730 		 * detaching.  Either way we must wait for *_attach or
2731 		 * *_detach to complete, and either way we must retry:
2732 		 * even if detaching, *_detach might fail (EBUSY) so
2733 		 * the device may still be there.
2734 		 */
2735 		if ((dv->dv_attaching != NULL && dv->dv_attaching != curlwp) ||
2736 		    dv->dv_detaching != NULL) {
2737 			mutex_exit(&alldevs_lock);
2738 			cv_wait(&config_misc_cv, &config_misc_lock);
2739 			mutex_enter(&alldevs_lock);
2740 			goto retry;
2741 		}
2742 		localcount_acquire(dv->dv_localcount);
2743 	}
2744 	mutex_exit(&alldevs_lock);
2745 	mutex_exit(&config_misc_lock);
2746 
2747 	return dv;
2748 }
2749 
2750 /*
2751  * device_release:
2752  *
2753  *	Release a reference to a device acquired with
2754  *	device_lookup_acquire.
2755  */
2756 void
2757 device_release(device_t dv)
2758 {
2759 
2760 	localcount_release(dv->dv_localcount,
2761 	    &config_misc_cv, &config_misc_lock);
2762 }
2763 
2764 /*
2765  * device_find_by_xname:
2766  *
2767  *	Returns the device of the given name or NULL if it doesn't exist.
2768  */
2769 device_t
2770 device_find_by_xname(const char *name)
2771 {
2772 	device_t dv;
2773 	deviter_t di;
2774 
2775 	for (dv = deviter_first(&di, 0); dv != NULL; dv = deviter_next(&di)) {
2776 		if (strcmp(device_xname(dv), name) == 0)
2777 			break;
2778 	}
2779 	deviter_release(&di);
2780 
2781 	return dv;
2782 }
2783 
2784 /*
2785  * device_find_by_driver_unit:
2786  *
2787  *	Returns the device of the given driver name and unit or
2788  *	NULL if it doesn't exist.
2789  */
2790 device_t
2791 device_find_by_driver_unit(const char *name, int unit)
2792 {
2793 	struct cfdriver *cd;
2794 
2795 	if ((cd = config_cfdriver_lookup(name)) == NULL)
2796 		return NULL;
2797 	return device_lookup(cd, unit);
2798 }
2799 
2800 static bool
2801 match_strcmp(const char * const s1, const char * const s2)
2802 {
2803 	return strcmp(s1, s2) == 0;
2804 }
2805 
2806 static bool
2807 match_pmatch(const char * const s1, const char * const s2)
2808 {
2809 	return pmatch(s1, s2, NULL) == 2;
2810 }
2811 
2812 static bool
2813 strarray_match_internal(const char ** const strings,
2814     unsigned int const nstrings, const char * const str,
2815     unsigned int * const indexp,
2816     bool (*match_fn)(const char *, const char *))
2817 {
2818 	unsigned int i;
2819 
2820 	if (strings == NULL || nstrings == 0) {
2821 		return false;
2822 	}
2823 
2824 	for (i = 0; i < nstrings; i++) {
2825 		if ((*match_fn)(strings[i], str)) {
2826 			*indexp = i;
2827 			return true;
2828 		}
2829 	}
2830 
2831 	return false;
2832 }
2833 
2834 static int
2835 strarray_match(const char ** const strings, unsigned int const nstrings,
2836     const char * const str)
2837 {
2838 	unsigned int idx;
2839 
2840 	if (strarray_match_internal(strings, nstrings, str, &idx,
2841 				    match_strcmp)) {
2842 		return (int)(nstrings - idx);
2843 	}
2844 	return 0;
2845 }
2846 
2847 static int
2848 strarray_pmatch(const char ** const strings, unsigned int const nstrings,
2849     const char * const pattern)
2850 {
2851 	unsigned int idx;
2852 
2853 	if (strarray_match_internal(strings, nstrings, pattern, &idx,
2854 				    match_pmatch)) {
2855 		return (int)(nstrings - idx);
2856 	}
2857 	return 0;
2858 }
2859 
2860 static int
2861 device_compatible_match_strarray_internal(
2862     const char **device_compats, int ndevice_compats,
2863     const struct device_compatible_entry *driver_compats,
2864     const struct device_compatible_entry **matching_entryp,
2865     int (*match_fn)(const char **, unsigned int, const char *))
2866 {
2867 	const struct device_compatible_entry *dce = NULL;
2868 	int rv;
2869 
2870 	if (ndevice_compats == 0 || device_compats == NULL ||
2871 	    driver_compats == NULL)
2872 		return 0;
2873 
2874 	for (dce = driver_compats; dce->compat != NULL; dce++) {
2875 		rv = (*match_fn)(device_compats, ndevice_compats, dce->compat);
2876 		if (rv != 0) {
2877 			if (matching_entryp != NULL) {
2878 				*matching_entryp = dce;
2879 			}
2880 			return rv;
2881 		}
2882 	}
2883 	return 0;
2884 }
2885 
2886 /*
2887  * device_compatible_match:
2888  *
2889  *	Match a driver's "compatible" data against a device's
2890  *	"compatible" strings.  Returns resulted weighted by
2891  *	which device "compatible" string was matched.
2892  */
2893 int
2894 device_compatible_match(const char **device_compats, int ndevice_compats,
2895     const struct device_compatible_entry *driver_compats)
2896 {
2897 	return device_compatible_match_strarray_internal(device_compats,
2898 	    ndevice_compats, driver_compats, NULL, strarray_match);
2899 }
2900 
2901 /*
2902  * device_compatible_pmatch:
2903  *
2904  *	Like device_compatible_match(), but uses pmatch(9) to compare
2905  *	the device "compatible" strings against patterns in the
2906  *	driver's "compatible" data.
2907  */
2908 int
2909 device_compatible_pmatch(const char **device_compats, int ndevice_compats,
2910     const struct device_compatible_entry *driver_compats)
2911 {
2912 	return device_compatible_match_strarray_internal(device_compats,
2913 	    ndevice_compats, driver_compats, NULL, strarray_pmatch);
2914 }
2915 
2916 static int
2917 device_compatible_match_strlist_internal(
2918     const char * const device_compats, size_t const device_compatsize,
2919     const struct device_compatible_entry *driver_compats,
2920     const struct device_compatible_entry **matching_entryp,
2921     int (*match_fn)(const char *, size_t, const char *))
2922 {
2923 	const struct device_compatible_entry *dce = NULL;
2924 	int rv;
2925 
2926 	if (device_compats == NULL || device_compatsize == 0 ||
2927 	    driver_compats == NULL)
2928 		return 0;
2929 
2930 	for (dce = driver_compats; dce->compat != NULL; dce++) {
2931 		rv = (*match_fn)(device_compats, device_compatsize,
2932 		    dce->compat);
2933 		if (rv != 0) {
2934 			if (matching_entryp != NULL) {
2935 				*matching_entryp = dce;
2936 			}
2937 			return rv;
2938 		}
2939 	}
2940 	return 0;
2941 }
2942 
2943 /*
2944  * device_compatible_match_strlist:
2945  *
2946  *	Like device_compatible_match(), but take the device
2947  *	"compatible" strings as an OpenFirmware-style string
2948  *	list.
2949  */
2950 int
2951 device_compatible_match_strlist(
2952     const char * const device_compats, size_t const device_compatsize,
2953     const struct device_compatible_entry *driver_compats)
2954 {
2955 	return device_compatible_match_strlist_internal(device_compats,
2956 	    device_compatsize, driver_compats, NULL, strlist_match);
2957 }
2958 
2959 /*
2960  * device_compatible_pmatch_strlist:
2961  *
2962  *	Like device_compatible_pmatch(), but take the device
2963  *	"compatible" strings as an OpenFirmware-style string
2964  *	list.
2965  */
2966 int
2967 device_compatible_pmatch_strlist(
2968     const char * const device_compats, size_t const device_compatsize,
2969     const struct device_compatible_entry *driver_compats)
2970 {
2971 	return device_compatible_match_strlist_internal(device_compats,
2972 	    device_compatsize, driver_compats, NULL, strlist_pmatch);
2973 }
2974 
2975 static int
2976 device_compatible_match_id_internal(
2977     uintptr_t const id, uintptr_t const mask, uintptr_t const sentinel_id,
2978     const struct device_compatible_entry *driver_compats,
2979     const struct device_compatible_entry **matching_entryp)
2980 {
2981 	const struct device_compatible_entry *dce = NULL;
2982 
2983 	if (mask == 0)
2984 		return 0;
2985 
2986 	for (dce = driver_compats; dce->id != sentinel_id; dce++) {
2987 		if ((id & mask) == dce->id) {
2988 			if (matching_entryp != NULL) {
2989 				*matching_entryp = dce;
2990 			}
2991 			return 1;
2992 		}
2993 	}
2994 	return 0;
2995 }
2996 
2997 /*
2998  * device_compatible_match_id:
2999  *
3000  *	Like device_compatible_match(), but takes a single
3001  *	unsigned integer device ID.
3002  */
3003 int
3004 device_compatible_match_id(
3005     uintptr_t const id, uintptr_t const sentinel_id,
3006     const struct device_compatible_entry *driver_compats)
3007 {
3008 	return device_compatible_match_id_internal(id, (uintptr_t)-1,
3009 	    sentinel_id, driver_compats, NULL);
3010 }
3011 
3012 /*
3013  * device_compatible_lookup:
3014  *
3015  *	Look up and return the device_compatible_entry, using the
3016  *	same matching criteria used by device_compatible_match().
3017  */
3018 const struct device_compatible_entry *
3019 device_compatible_lookup(const char **device_compats, int ndevice_compats,
3020 			 const struct device_compatible_entry *driver_compats)
3021 {
3022 	const struct device_compatible_entry *dce;
3023 
3024 	if (device_compatible_match_strarray_internal(device_compats,
3025 	    ndevice_compats, driver_compats, &dce, strarray_match)) {
3026 		return dce;
3027 	}
3028 	return NULL;
3029 }
3030 
3031 /*
3032  * device_compatible_plookup:
3033  *
3034  *	Look up and return the device_compatible_entry, using the
3035  *	same matching criteria used by device_compatible_pmatch().
3036  */
3037 const struct device_compatible_entry *
3038 device_compatible_plookup(const char **device_compats, int ndevice_compats,
3039 			  const struct device_compatible_entry *driver_compats)
3040 {
3041 	const struct device_compatible_entry *dce;
3042 
3043 	if (device_compatible_match_strarray_internal(device_compats,
3044 	    ndevice_compats, driver_compats, &dce, strarray_pmatch)) {
3045 		return dce;
3046 	}
3047 	return NULL;
3048 }
3049 
3050 /*
3051  * device_compatible_lookup_strlist:
3052  *
3053  *	Like device_compatible_lookup(), but take the device
3054  *	"compatible" strings as an OpenFirmware-style string
3055  *	list.
3056  */
3057 const struct device_compatible_entry *
3058 device_compatible_lookup_strlist(
3059     const char * const device_compats, size_t const device_compatsize,
3060     const struct device_compatible_entry *driver_compats)
3061 {
3062 	const struct device_compatible_entry *dce;
3063 
3064 	if (device_compatible_match_strlist_internal(device_compats,
3065 	    device_compatsize, driver_compats, &dce, strlist_match)) {
3066 		return dce;
3067 	}
3068 	return NULL;
3069 }
3070 
3071 /*
3072  * device_compatible_plookup_strlist:
3073  *
3074  *	Like device_compatible_plookup(), but take the device
3075  *	"compatible" strings as an OpenFirmware-style string
3076  *	list.
3077  */
3078 const struct device_compatible_entry *
3079 device_compatible_plookup_strlist(
3080     const char * const device_compats, size_t const device_compatsize,
3081     const struct device_compatible_entry *driver_compats)
3082 {
3083 	const struct device_compatible_entry *dce;
3084 
3085 	if (device_compatible_match_strlist_internal(device_compats,
3086 	    device_compatsize, driver_compats, &dce, strlist_pmatch)) {
3087 		return dce;
3088 	}
3089 	return NULL;
3090 }
3091 
3092 /*
3093  * device_compatible_lookup_id:
3094  *
3095  *	Like device_compatible_lookup(), but takes a single
3096  *	unsigned integer device ID.
3097  */
3098 const struct device_compatible_entry *
3099 device_compatible_lookup_id(
3100     uintptr_t const id, uintptr_t const sentinel_id,
3101     const struct device_compatible_entry *driver_compats)
3102 {
3103 	const struct device_compatible_entry *dce;
3104 
3105 	if (device_compatible_match_id_internal(id, (uintptr_t)-1,
3106 	    sentinel_id, driver_compats, &dce)) {
3107 		return dce;
3108 	}
3109 	return NULL;
3110 }
3111 
3112 /*
3113  * Power management related functions.
3114  */
3115 
3116 bool
3117 device_pmf_is_registered(device_t dev)
3118 {
3119 	return (dev->dv_flags & DVF_POWER_HANDLERS) != 0;
3120 }
3121 
3122 bool
3123 device_pmf_driver_suspend(device_t dev, const pmf_qual_t *qual)
3124 {
3125 	if ((dev->dv_flags & DVF_DRIVER_SUSPENDED) != 0)
3126 		return true;
3127 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) == 0)
3128 		return false;
3129 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_DRIVER &&
3130 	    dev->dv_driver_suspend != NULL &&
3131 	    !(*dev->dv_driver_suspend)(dev, qual))
3132 		return false;
3133 
3134 	dev->dv_flags |= DVF_DRIVER_SUSPENDED;
3135 	return true;
3136 }
3137 
3138 bool
3139 device_pmf_driver_resume(device_t dev, const pmf_qual_t *qual)
3140 {
3141 	if ((dev->dv_flags & DVF_DRIVER_SUSPENDED) == 0)
3142 		return true;
3143 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) != 0)
3144 		return false;
3145 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_DRIVER &&
3146 	    dev->dv_driver_resume != NULL &&
3147 	    !(*dev->dv_driver_resume)(dev, qual))
3148 		return false;
3149 
3150 	dev->dv_flags &= ~DVF_DRIVER_SUSPENDED;
3151 	return true;
3152 }
3153 
3154 bool
3155 device_pmf_driver_shutdown(device_t dev, int how)
3156 {
3157 
3158 	if (*dev->dv_driver_shutdown != NULL &&
3159 	    !(*dev->dv_driver_shutdown)(dev, how))
3160 		return false;
3161 	return true;
3162 }
3163 
3164 void
3165 device_pmf_driver_register(device_t dev,
3166     bool (*suspend)(device_t, const pmf_qual_t *),
3167     bool (*resume)(device_t, const pmf_qual_t *),
3168     bool (*shutdown)(device_t, int))
3169 {
3170 
3171 	dev->dv_driver_suspend = suspend;
3172 	dev->dv_driver_resume = resume;
3173 	dev->dv_driver_shutdown = shutdown;
3174 	dev->dv_flags |= DVF_POWER_HANDLERS;
3175 }
3176 
3177 void
3178 device_pmf_driver_deregister(device_t dev)
3179 {
3180 	device_lock_t dvl = device_getlock(dev);
3181 
3182 	dev->dv_driver_suspend = NULL;
3183 	dev->dv_driver_resume = NULL;
3184 
3185 	mutex_enter(&dvl->dvl_mtx);
3186 	dev->dv_flags &= ~DVF_POWER_HANDLERS;
3187 	while (dvl->dvl_nlock > 0 || dvl->dvl_nwait > 0) {
3188 		/* Wake a thread that waits for the lock.  That
3189 		 * thread will fail to acquire the lock, and then
3190 		 * it will wake the next thread that waits for the
3191 		 * lock, or else it will wake us.
3192 		 */
3193 		cv_signal(&dvl->dvl_cv);
3194 		pmflock_debug(dev, __func__, __LINE__);
3195 		cv_wait(&dvl->dvl_cv, &dvl->dvl_mtx);
3196 		pmflock_debug(dev, __func__, __LINE__);
3197 	}
3198 	mutex_exit(&dvl->dvl_mtx);
3199 }
3200 
3201 void
3202 device_pmf_driver_child_register(device_t dev)
3203 {
3204 	device_t parent = device_parent(dev);
3205 
3206 	if (parent == NULL || parent->dv_driver_child_register == NULL)
3207 		return;
3208 	(*parent->dv_driver_child_register)(dev);
3209 }
3210 
3211 void
3212 device_pmf_driver_set_child_register(device_t dev,
3213     void (*child_register)(device_t))
3214 {
3215 	dev->dv_driver_child_register = child_register;
3216 }
3217 
3218 static void
3219 pmflock_debug(device_t dev, const char *func, int line)
3220 {
3221 #ifdef PMFLOCK_DEBUG
3222 	device_lock_t dvl = device_getlock(dev);
3223 	const char *curlwp_name;
3224 
3225 	if (curlwp->l_name != NULL)
3226 		curlwp_name = curlwp->l_name;
3227 	else
3228 		curlwp_name = curlwp->l_proc->p_comm;
3229 
3230 	aprint_debug_dev(dev,
3231 	    "%s.%d, %s dvl_nlock %d dvl_nwait %d dv_flags %x\n", func, line,
3232 	    curlwp_name, dvl->dvl_nlock, dvl->dvl_nwait, dev->dv_flags);
3233 #endif	/* PMFLOCK_DEBUG */
3234 }
3235 
3236 static bool
3237 device_pmf_lock1(device_t dev)
3238 {
3239 	device_lock_t dvl = device_getlock(dev);
3240 
3241 	while (device_pmf_is_registered(dev) &&
3242 	    dvl->dvl_nlock > 0 && dvl->dvl_holder != curlwp) {
3243 		dvl->dvl_nwait++;
3244 		pmflock_debug(dev, __func__, __LINE__);
3245 		cv_wait(&dvl->dvl_cv, &dvl->dvl_mtx);
3246 		pmflock_debug(dev, __func__, __LINE__);
3247 		dvl->dvl_nwait--;
3248 	}
3249 	if (!device_pmf_is_registered(dev)) {
3250 		pmflock_debug(dev, __func__, __LINE__);
3251 		/* We could not acquire the lock, but some other thread may
3252 		 * wait for it, also.  Wake that thread.
3253 		 */
3254 		cv_signal(&dvl->dvl_cv);
3255 		return false;
3256 	}
3257 	dvl->dvl_nlock++;
3258 	dvl->dvl_holder = curlwp;
3259 	pmflock_debug(dev, __func__, __LINE__);
3260 	return true;
3261 }
3262 
3263 bool
3264 device_pmf_lock(device_t dev)
3265 {
3266 	bool rc;
3267 	device_lock_t dvl = device_getlock(dev);
3268 
3269 	mutex_enter(&dvl->dvl_mtx);
3270 	rc = device_pmf_lock1(dev);
3271 	mutex_exit(&dvl->dvl_mtx);
3272 
3273 	return rc;
3274 }
3275 
3276 void
3277 device_pmf_unlock(device_t dev)
3278 {
3279 	device_lock_t dvl = device_getlock(dev);
3280 
3281 	KASSERT(dvl->dvl_nlock > 0);
3282 	mutex_enter(&dvl->dvl_mtx);
3283 	if (--dvl->dvl_nlock == 0)
3284 		dvl->dvl_holder = NULL;
3285 	cv_signal(&dvl->dvl_cv);
3286 	pmflock_debug(dev, __func__, __LINE__);
3287 	mutex_exit(&dvl->dvl_mtx);
3288 }
3289 
3290 device_lock_t
3291 device_getlock(device_t dev)
3292 {
3293 	return &dev->dv_lock;
3294 }
3295 
3296 void *
3297 device_pmf_bus_private(device_t dev)
3298 {
3299 	return dev->dv_bus_private;
3300 }
3301 
3302 bool
3303 device_pmf_bus_suspend(device_t dev, const pmf_qual_t *qual)
3304 {
3305 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) != 0)
3306 		return true;
3307 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) == 0 ||
3308 	    (dev->dv_flags & DVF_DRIVER_SUSPENDED) == 0)
3309 		return false;
3310 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_BUS &&
3311 	    dev->dv_bus_suspend != NULL &&
3312 	    !(*dev->dv_bus_suspend)(dev, qual))
3313 		return false;
3314 
3315 	dev->dv_flags |= DVF_BUS_SUSPENDED;
3316 	return true;
3317 }
3318 
3319 bool
3320 device_pmf_bus_resume(device_t dev, const pmf_qual_t *qual)
3321 {
3322 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) == 0)
3323 		return true;
3324 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_BUS &&
3325 	    dev->dv_bus_resume != NULL &&
3326 	    !(*dev->dv_bus_resume)(dev, qual))
3327 		return false;
3328 
3329 	dev->dv_flags &= ~DVF_BUS_SUSPENDED;
3330 	return true;
3331 }
3332 
3333 bool
3334 device_pmf_bus_shutdown(device_t dev, int how)
3335 {
3336 
3337 	if (*dev->dv_bus_shutdown != NULL &&
3338 	    !(*dev->dv_bus_shutdown)(dev, how))
3339 		return false;
3340 	return true;
3341 }
3342 
3343 void
3344 device_pmf_bus_register(device_t dev, void *priv,
3345     bool (*suspend)(device_t, const pmf_qual_t *),
3346     bool (*resume)(device_t, const pmf_qual_t *),
3347     bool (*shutdown)(device_t, int), void (*deregister)(device_t))
3348 {
3349 	dev->dv_bus_private = priv;
3350 	dev->dv_bus_resume = resume;
3351 	dev->dv_bus_suspend = suspend;
3352 	dev->dv_bus_shutdown = shutdown;
3353 	dev->dv_bus_deregister = deregister;
3354 }
3355 
3356 void
3357 device_pmf_bus_deregister(device_t dev)
3358 {
3359 	if (dev->dv_bus_deregister == NULL)
3360 		return;
3361 	(*dev->dv_bus_deregister)(dev);
3362 	dev->dv_bus_private = NULL;
3363 	dev->dv_bus_suspend = NULL;
3364 	dev->dv_bus_resume = NULL;
3365 	dev->dv_bus_deregister = NULL;
3366 }
3367 
3368 void *
3369 device_pmf_class_private(device_t dev)
3370 {
3371 	return dev->dv_class_private;
3372 }
3373 
3374 bool
3375 device_pmf_class_suspend(device_t dev, const pmf_qual_t *qual)
3376 {
3377 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) != 0)
3378 		return true;
3379 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_CLASS &&
3380 	    dev->dv_class_suspend != NULL &&
3381 	    !(*dev->dv_class_suspend)(dev, qual))
3382 		return false;
3383 
3384 	dev->dv_flags |= DVF_CLASS_SUSPENDED;
3385 	return true;
3386 }
3387 
3388 bool
3389 device_pmf_class_resume(device_t dev, const pmf_qual_t *qual)
3390 {
3391 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) == 0)
3392 		return true;
3393 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) != 0 ||
3394 	    (dev->dv_flags & DVF_DRIVER_SUSPENDED) != 0)
3395 		return false;
3396 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_CLASS &&
3397 	    dev->dv_class_resume != NULL &&
3398 	    !(*dev->dv_class_resume)(dev, qual))
3399 		return false;
3400 
3401 	dev->dv_flags &= ~DVF_CLASS_SUSPENDED;
3402 	return true;
3403 }
3404 
3405 void
3406 device_pmf_class_register(device_t dev, void *priv,
3407     bool (*suspend)(device_t, const pmf_qual_t *),
3408     bool (*resume)(device_t, const pmf_qual_t *),
3409     void (*deregister)(device_t))
3410 {
3411 	dev->dv_class_private = priv;
3412 	dev->dv_class_suspend = suspend;
3413 	dev->dv_class_resume = resume;
3414 	dev->dv_class_deregister = deregister;
3415 }
3416 
3417 void
3418 device_pmf_class_deregister(device_t dev)
3419 {
3420 	if (dev->dv_class_deregister == NULL)
3421 		return;
3422 	(*dev->dv_class_deregister)(dev);
3423 	dev->dv_class_private = NULL;
3424 	dev->dv_class_suspend = NULL;
3425 	dev->dv_class_resume = NULL;
3426 	dev->dv_class_deregister = NULL;
3427 }
3428 
3429 bool
3430 device_active(device_t dev, devactive_t type)
3431 {
3432 	size_t i;
3433 
3434 	if (dev->dv_activity_count == 0)
3435 		return false;
3436 
3437 	for (i = 0; i < dev->dv_activity_count; ++i) {
3438 		if (dev->dv_activity_handlers[i] == NULL)
3439 			break;
3440 		(*dev->dv_activity_handlers[i])(dev, type);
3441 	}
3442 
3443 	return true;
3444 }
3445 
3446 bool
3447 device_active_register(device_t dev, void (*handler)(device_t, devactive_t))
3448 {
3449 	void (**new_handlers)(device_t, devactive_t);
3450 	void (**old_handlers)(device_t, devactive_t);
3451 	size_t i, old_size, new_size;
3452 	int s;
3453 
3454 	old_handlers = dev->dv_activity_handlers;
3455 	old_size = dev->dv_activity_count;
3456 
3457 	KASSERT(old_size == 0 || old_handlers != NULL);
3458 
3459 	for (i = 0; i < old_size; ++i) {
3460 		KASSERT(old_handlers[i] != handler);
3461 		if (old_handlers[i] == NULL) {
3462 			old_handlers[i] = handler;
3463 			return true;
3464 		}
3465 	}
3466 
3467 	new_size = old_size + 4;
3468 	new_handlers = kmem_alloc(sizeof(void *) * new_size, KM_SLEEP);
3469 
3470 	for (i = 0; i < old_size; ++i)
3471 		new_handlers[i] = old_handlers[i];
3472 	new_handlers[old_size] = handler;
3473 	for (i = old_size+1; i < new_size; ++i)
3474 		new_handlers[i] = NULL;
3475 
3476 	s = splhigh();
3477 	dev->dv_activity_count = new_size;
3478 	dev->dv_activity_handlers = new_handlers;
3479 	splx(s);
3480 
3481 	if (old_size > 0)
3482 		kmem_free(old_handlers, sizeof(void *) * old_size);
3483 
3484 	return true;
3485 }
3486 
3487 void
3488 device_active_deregister(device_t dev, void (*handler)(device_t, devactive_t))
3489 {
3490 	void (**old_handlers)(device_t, devactive_t);
3491 	size_t i, old_size;
3492 	int s;
3493 
3494 	old_handlers = dev->dv_activity_handlers;
3495 	old_size = dev->dv_activity_count;
3496 
3497 	for (i = 0; i < old_size; ++i) {
3498 		if (old_handlers[i] == handler)
3499 			break;
3500 		if (old_handlers[i] == NULL)
3501 			return; /* XXX panic? */
3502 	}
3503 
3504 	if (i == old_size)
3505 		return; /* XXX panic? */
3506 
3507 	for (; i < old_size - 1; ++i) {
3508 		if ((old_handlers[i] = old_handlers[i + 1]) != NULL)
3509 			continue;
3510 
3511 		if (i == 0) {
3512 			s = splhigh();
3513 			dev->dv_activity_count = 0;
3514 			dev->dv_activity_handlers = NULL;
3515 			splx(s);
3516 			kmem_free(old_handlers, sizeof(void *) * old_size);
3517 		}
3518 		return;
3519 	}
3520 	old_handlers[i] = NULL;
3521 }
3522 
3523 /* Return true iff the device_t `dev' exists at generation `gen'. */
3524 static bool
3525 device_exists_at(device_t dv, devgen_t gen)
3526 {
3527 	return (dv->dv_del_gen == 0 || dv->dv_del_gen > gen) &&
3528 	    dv->dv_add_gen <= gen;
3529 }
3530 
3531 static bool
3532 deviter_visits(const deviter_t *di, device_t dv)
3533 {
3534 	return device_exists_at(dv, di->di_gen);
3535 }
3536 
3537 /*
3538  * Device Iteration
3539  *
3540  * deviter_t: a device iterator.  Holds state for a "walk" visiting
3541  *     each device_t's in the device tree.
3542  *
3543  * deviter_init(di, flags): initialize the device iterator `di'
3544  *     to "walk" the device tree.  deviter_next(di) will return
3545  *     the first device_t in the device tree, or NULL if there are
3546  *     no devices.
3547  *
3548  *     `flags' is one or more of DEVITER_F_RW, indicating that the
3549  *     caller intends to modify the device tree by calling
3550  *     config_detach(9) on devices in the order that the iterator
3551  *     returns them; DEVITER_F_ROOT_FIRST, asking for the devices
3552  *     nearest the "root" of the device tree to be returned, first;
3553  *     DEVITER_F_LEAVES_FIRST, asking for the devices furthest from
3554  *     the root of the device tree, first; and DEVITER_F_SHUTDOWN,
3555  *     indicating both that deviter_init() should not respect any
3556  *     locks on the device tree, and that deviter_next(di) may run
3557  *     in more than one LWP before the walk has finished.
3558  *
3559  *     Only one DEVITER_F_RW iterator may be in the device tree at
3560  *     once.
3561  *
3562  *     DEVITER_F_SHUTDOWN implies DEVITER_F_RW.
3563  *
3564  *     Results are undefined if the flags DEVITER_F_ROOT_FIRST and
3565  *     DEVITER_F_LEAVES_FIRST are used in combination.
3566  *
3567  * deviter_first(di, flags): initialize the device iterator `di'
3568  *     and return the first device_t in the device tree, or NULL
3569  *     if there are no devices.  The statement
3570  *
3571  *         dv = deviter_first(di);
3572  *
3573  *     is shorthand for
3574  *
3575  *         deviter_init(di);
3576  *         dv = deviter_next(di);
3577  *
3578  * deviter_next(di): return the next device_t in the device tree,
3579  *     or NULL if there are no more devices.  deviter_next(di)
3580  *     is undefined if `di' was not initialized with deviter_init() or
3581  *     deviter_first().
3582  *
3583  * deviter_release(di): stops iteration (subsequent calls to
3584  *     deviter_next() will return NULL), releases any locks and
3585  *     resources held by the device iterator.
3586  *
3587  * Device iteration does not return device_t's in any particular
3588  * order.  An iterator will never return the same device_t twice.
3589  * Device iteration is guaranteed to complete---i.e., if deviter_next(di)
3590  * is called repeatedly on the same `di', it will eventually return
3591  * NULL.  It is ok to attach/detach devices during device iteration.
3592  */
3593 void
3594 deviter_init(deviter_t *di, deviter_flags_t flags)
3595 {
3596 	device_t dv;
3597 
3598 	memset(di, 0, sizeof(*di));
3599 
3600 	if ((flags & DEVITER_F_SHUTDOWN) != 0)
3601 		flags |= DEVITER_F_RW;
3602 
3603 	mutex_enter(&alldevs_lock);
3604 	if ((flags & DEVITER_F_RW) != 0)
3605 		alldevs_nwrite++;
3606 	else
3607 		alldevs_nread++;
3608 	di->di_gen = alldevs_gen++;
3609 	di->di_flags = flags;
3610 
3611 	switch (di->di_flags & (DEVITER_F_LEAVES_FIRST|DEVITER_F_ROOT_FIRST)) {
3612 	case DEVITER_F_LEAVES_FIRST:
3613 		TAILQ_FOREACH(dv, &alldevs, dv_list) {
3614 			if (!deviter_visits(di, dv))
3615 				continue;
3616 			di->di_curdepth = MAX(di->di_curdepth, dv->dv_depth);
3617 		}
3618 		break;
3619 	case DEVITER_F_ROOT_FIRST:
3620 		TAILQ_FOREACH(dv, &alldevs, dv_list) {
3621 			if (!deviter_visits(di, dv))
3622 				continue;
3623 			di->di_maxdepth = MAX(di->di_maxdepth, dv->dv_depth);
3624 		}
3625 		break;
3626 	default:
3627 		break;
3628 	}
3629 
3630 	deviter_reinit(di);
3631 	mutex_exit(&alldevs_lock);
3632 }
3633 
3634 static void
3635 deviter_reinit(deviter_t *di)
3636 {
3637 
3638 	KASSERT(mutex_owned(&alldevs_lock));
3639 	if ((di->di_flags & DEVITER_F_RW) != 0)
3640 		di->di_prev = TAILQ_LAST(&alldevs, devicelist);
3641 	else
3642 		di->di_prev = TAILQ_FIRST(&alldevs);
3643 }
3644 
3645 device_t
3646 deviter_first(deviter_t *di, deviter_flags_t flags)
3647 {
3648 
3649 	deviter_init(di, flags);
3650 	return deviter_next(di);
3651 }
3652 
3653 static device_t
3654 deviter_next2(deviter_t *di)
3655 {
3656 	device_t dv;
3657 
3658 	KASSERT(mutex_owned(&alldevs_lock));
3659 
3660 	dv = di->di_prev;
3661 
3662 	if (dv == NULL)
3663 		return NULL;
3664 
3665 	if ((di->di_flags & DEVITER_F_RW) != 0)
3666 		di->di_prev = TAILQ_PREV(dv, devicelist, dv_list);
3667 	else
3668 		di->di_prev = TAILQ_NEXT(dv, dv_list);
3669 
3670 	return dv;
3671 }
3672 
3673 static device_t
3674 deviter_next1(deviter_t *di)
3675 {
3676 	device_t dv;
3677 
3678 	KASSERT(mutex_owned(&alldevs_lock));
3679 
3680 	do {
3681 		dv = deviter_next2(di);
3682 	} while (dv != NULL && !deviter_visits(di, dv));
3683 
3684 	return dv;
3685 }
3686 
3687 device_t
3688 deviter_next(deviter_t *di)
3689 {
3690 	device_t dv = NULL;
3691 
3692 	mutex_enter(&alldevs_lock);
3693 	switch (di->di_flags & (DEVITER_F_LEAVES_FIRST|DEVITER_F_ROOT_FIRST)) {
3694 	case 0:
3695 		dv = deviter_next1(di);
3696 		break;
3697 	case DEVITER_F_LEAVES_FIRST:
3698 		while (di->di_curdepth >= 0) {
3699 			if ((dv = deviter_next1(di)) == NULL) {
3700 				di->di_curdepth--;
3701 				deviter_reinit(di);
3702 			} else if (dv->dv_depth == di->di_curdepth)
3703 				break;
3704 		}
3705 		break;
3706 	case DEVITER_F_ROOT_FIRST:
3707 		while (di->di_curdepth <= di->di_maxdepth) {
3708 			if ((dv = deviter_next1(di)) == NULL) {
3709 				di->di_curdepth++;
3710 				deviter_reinit(di);
3711 			} else if (dv->dv_depth == di->di_curdepth)
3712 				break;
3713 		}
3714 		break;
3715 	default:
3716 		break;
3717 	}
3718 	mutex_exit(&alldevs_lock);
3719 
3720 	return dv;
3721 }
3722 
3723 void
3724 deviter_release(deviter_t *di)
3725 {
3726 	bool rw = (di->di_flags & DEVITER_F_RW) != 0;
3727 
3728 	mutex_enter(&alldevs_lock);
3729 	if (rw)
3730 		--alldevs_nwrite;
3731 	else
3732 		--alldevs_nread;
3733 	/* XXX wake a garbage-collection thread */
3734 	mutex_exit(&alldevs_lock);
3735 }
3736 
3737 const char *
3738 cfdata_ifattr(const struct cfdata *cf)
3739 {
3740 	return cf->cf_pspec->cfp_iattr;
3741 }
3742 
3743 bool
3744 ifattr_match(const char *snull, const char *t)
3745 {
3746 	return (snull == NULL) || strcmp(snull, t) == 0;
3747 }
3748 
3749 void
3750 null_childdetached(device_t self, device_t child)
3751 {
3752 	/* do nothing */
3753 }
3754 
3755 static void
3756 sysctl_detach_setup(struct sysctllog **clog)
3757 {
3758 
3759 	sysctl_createv(clog, 0, NULL, NULL,
3760 		CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
3761 		CTLTYPE_BOOL, "detachall",
3762 		SYSCTL_DESCR("Detach all devices at shutdown"),
3763 		NULL, 0, &detachall, 0,
3764 		CTL_KERN, CTL_CREATE, CTL_EOL);
3765 }
3766