xref: /netbsd-src/sys/kern/subr_autoconf.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /* $NetBSD: subr_autoconf.c,v 1.262 2018/06/26 06:03:57 thorpej Exp $ */
2 
3 /*
4  * Copyright (c) 1996, 2000 Christopher G. Demetriou
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *          This product includes software developed for the
18  *          NetBSD Project.  See http://www.NetBSD.org/ for
19  *          information about NetBSD.
20  * 4. The name of the author may not be used to endorse or promote products
21  *    derived from this software without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
27  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33  *
34  * --(license Id: LICENSE.proto,v 1.1 2000/06/13 21:40:26 cgd Exp )--
35  */
36 
37 /*
38  * Copyright (c) 1992, 1993
39  *	The Regents of the University of California.  All rights reserved.
40  *
41  * This software was developed by the Computer Systems Engineering group
42  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
43  * contributed to Berkeley.
44  *
45  * All advertising materials mentioning features or use of this software
46  * must display the following acknowledgement:
47  *	This product includes software developed by the University of
48  *	California, Lawrence Berkeley Laboratories.
49  *
50  * Redistribution and use in source and binary forms, with or without
51  * modification, are permitted provided that the following conditions
52  * are met:
53  * 1. Redistributions of source code must retain the above copyright
54  *    notice, this list of conditions and the following disclaimer.
55  * 2. Redistributions in binary form must reproduce the above copyright
56  *    notice, this list of conditions and the following disclaimer in the
57  *    documentation and/or other materials provided with the distribution.
58  * 3. 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 1.262 2018/06/26 06:03:57 thorpej 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/disklabel.h>
90 #include <sys/conf.h>
91 #include <sys/kauth.h>
92 #include <sys/kmem.h>
93 #include <sys/systm.h>
94 #include <sys/kernel.h>
95 #include <sys/errno.h>
96 #include <sys/proc.h>
97 #include <sys/reboot.h>
98 #include <sys/kthread.h>
99 #include <sys/buf.h>
100 #include <sys/dirent.h>
101 #include <sys/mount.h>
102 #include <sys/namei.h>
103 #include <sys/unistd.h>
104 #include <sys/fcntl.h>
105 #include <sys/lockf.h>
106 #include <sys/callout.h>
107 #include <sys/devmon.h>
108 #include <sys/cpu.h>
109 #include <sys/sysctl.h>
110 
111 #include <sys/disk.h>
112 
113 #include <sys/rndsource.h>
114 
115 #include <machine/limits.h>
116 
117 /*
118  * Autoconfiguration subroutines.
119  */
120 
121 /*
122  * Device autoconfiguration timings are mixed into the entropy pool.
123  */
124 extern krndsource_t rnd_autoconf_source;
125 
126 /*
127  * ioconf.c exports exactly two names: cfdata and cfroots.  All system
128  * devices and drivers are found via these tables.
129  */
130 extern struct cfdata cfdata[];
131 extern const short cfroots[];
132 
133 /*
134  * List of all cfdriver structures.  We use this to detect duplicates
135  * when other cfdrivers are loaded.
136  */
137 struct cfdriverlist allcfdrivers = LIST_HEAD_INITIALIZER(&allcfdrivers);
138 extern struct cfdriver * const cfdriver_list_initial[];
139 
140 /*
141  * Initial list of cfattach's.
142  */
143 extern const struct cfattachinit cfattachinit[];
144 
145 /*
146  * List of cfdata tables.  We always have one such list -- the one
147  * built statically when the kernel was configured.
148  */
149 struct cftablelist allcftables = TAILQ_HEAD_INITIALIZER(allcftables);
150 static struct cftable initcftable;
151 
152 #define	ROOT ((device_t)NULL)
153 
154 struct matchinfo {
155 	cfsubmatch_t fn;
156 	device_t parent;
157 	const int *locs;
158 	void	*aux;
159 	struct	cfdata *match;
160 	int	pri;
161 };
162 
163 struct alldevs_foray {
164 	int			af_s;
165 	struct devicelist	af_garbage;
166 };
167 
168 static char *number(char *, int);
169 static void mapply(struct matchinfo *, cfdata_t);
170 static device_t config_devalloc(const device_t, const cfdata_t, const int *);
171 static void config_devdelete(device_t);
172 static void config_devunlink(device_t, struct devicelist *);
173 static void config_makeroom(int, struct cfdriver *);
174 static void config_devlink(device_t);
175 static void config_alldevs_enter(struct alldevs_foray *);
176 static void config_alldevs_exit(struct alldevs_foray *);
177 static void config_add_attrib_dict(device_t);
178 
179 static void config_collect_garbage(struct devicelist *);
180 static void config_dump_garbage(struct devicelist *);
181 
182 static void pmflock_debug(device_t, const char *, int);
183 
184 static device_t deviter_next1(deviter_t *);
185 static void deviter_reinit(deviter_t *);
186 
187 struct deferred_config {
188 	TAILQ_ENTRY(deferred_config) dc_queue;
189 	device_t dc_dev;
190 	void (*dc_func)(device_t);
191 };
192 
193 TAILQ_HEAD(deferred_config_head, deferred_config);
194 
195 struct deferred_config_head deferred_config_queue =
196 	TAILQ_HEAD_INITIALIZER(deferred_config_queue);
197 struct deferred_config_head interrupt_config_queue =
198 	TAILQ_HEAD_INITIALIZER(interrupt_config_queue);
199 int interrupt_config_threads = 8;
200 struct deferred_config_head mountroot_config_queue =
201 	TAILQ_HEAD_INITIALIZER(mountroot_config_queue);
202 int mountroot_config_threads = 2;
203 static lwp_t **mountroot_config_lwpids;
204 static size_t mountroot_config_lwpids_size;
205 static bool root_is_mounted = false;
206 
207 static void config_process_deferred(struct deferred_config_head *, device_t);
208 
209 /* Hooks to finalize configuration once all real devices have been found. */
210 struct finalize_hook {
211 	TAILQ_ENTRY(finalize_hook) f_list;
212 	int (*f_func)(device_t);
213 	device_t f_dev;
214 };
215 static TAILQ_HEAD(, finalize_hook) config_finalize_list =
216 	TAILQ_HEAD_INITIALIZER(config_finalize_list);
217 static int config_finalize_done;
218 
219 /* list of all devices */
220 static struct devicelist alldevs = TAILQ_HEAD_INITIALIZER(alldevs);
221 static kmutex_t alldevs_lock __cacheline_aligned;
222 static devgen_t alldevs_gen = 1;
223 static int alldevs_nread = 0;
224 static int alldevs_nwrite = 0;
225 static bool alldevs_garbage = false;
226 
227 static int config_pending;		/* semaphore for mountroot */
228 static kmutex_t config_misc_lock;
229 static kcondvar_t config_misc_cv;
230 
231 static bool detachall = false;
232 
233 #define	STREQ(s1, s2)			\
234 	(*(s1) == *(s2) && strcmp((s1), (s2)) == 0)
235 
236 static bool config_initialized = false;	/* config_init() has been called. */
237 
238 static int config_do_twiddle;
239 static callout_t config_twiddle_ch;
240 
241 static void sysctl_detach_setup(struct sysctllog **);
242 
243 int no_devmon_insert(const char *, prop_dictionary_t);
244 int (*devmon_insert_vec)(const char *, prop_dictionary_t) = no_devmon_insert;
245 
246 typedef int (*cfdriver_fn)(struct cfdriver *);
247 static int
248 frob_cfdrivervec(struct cfdriver * const *cfdriverv,
249 	cfdriver_fn drv_do, cfdriver_fn drv_undo,
250 	const char *style, bool dopanic)
251 {
252 	void (*pr)(const char *, ...) __printflike(1, 2) =
253 	    dopanic ? panic : printf;
254 	int i, error = 0, e2 __diagused;
255 
256 	for (i = 0; cfdriverv[i] != NULL; i++) {
257 		if ((error = drv_do(cfdriverv[i])) != 0) {
258 			pr("configure: `%s' driver %s failed: %d",
259 			    cfdriverv[i]->cd_name, style, error);
260 			goto bad;
261 		}
262 	}
263 
264 	KASSERT(error == 0);
265 	return 0;
266 
267  bad:
268 	printf("\n");
269 	for (i--; i >= 0; i--) {
270 		e2 = drv_undo(cfdriverv[i]);
271 		KASSERT(e2 == 0);
272 	}
273 
274 	return error;
275 }
276 
277 typedef int (*cfattach_fn)(const char *, struct cfattach *);
278 static int
279 frob_cfattachvec(const struct cfattachinit *cfattachv,
280 	cfattach_fn att_do, cfattach_fn att_undo,
281 	const char *style, bool dopanic)
282 {
283 	const struct cfattachinit *cfai = NULL;
284 	void (*pr)(const char *, ...) __printflike(1, 2) =
285 	    dopanic ? panic : printf;
286 	int j = 0, error = 0, e2 __diagused;
287 
288 	for (cfai = &cfattachv[0]; cfai->cfai_name != NULL; cfai++) {
289 		for (j = 0; cfai->cfai_list[j] != NULL; j++) {
290 			if ((error = att_do(cfai->cfai_name,
291 			    cfai->cfai_list[j])) != 0) {
292 				pr("configure: attachment `%s' "
293 				    "of `%s' driver %s failed: %d",
294 				    cfai->cfai_list[j]->ca_name,
295 				    cfai->cfai_name, style, error);
296 				goto bad;
297 			}
298 		}
299 	}
300 
301 	KASSERT(error == 0);
302 	return 0;
303 
304  bad:
305 	/*
306 	 * Rollback in reverse order.  dunno if super-important, but
307 	 * do that anyway.  Although the code looks a little like
308 	 * someone did a little integration (in the math sense).
309 	 */
310 	printf("\n");
311 	if (cfai) {
312 		bool last;
313 
314 		for (last = false; last == false; ) {
315 			if (cfai == &cfattachv[0])
316 				last = true;
317 			for (j--; j >= 0; j--) {
318 				e2 = att_undo(cfai->cfai_name,
319 				    cfai->cfai_list[j]);
320 				KASSERT(e2 == 0);
321 			}
322 			if (!last) {
323 				cfai--;
324 				for (j = 0; cfai->cfai_list[j] != NULL; j++)
325 					;
326 			}
327 		}
328 	}
329 
330 	return error;
331 }
332 
333 /*
334  * Initialize the autoconfiguration data structures.  Normally this
335  * is done by configure(), but some platforms need to do this very
336  * early (to e.g. initialize the console).
337  */
338 void
339 config_init(void)
340 {
341 
342 	KASSERT(config_initialized == false);
343 
344 	mutex_init(&alldevs_lock, MUTEX_DEFAULT, IPL_VM);
345 
346 	mutex_init(&config_misc_lock, MUTEX_DEFAULT, IPL_NONE);
347 	cv_init(&config_misc_cv, "cfgmisc");
348 
349 	callout_init(&config_twiddle_ch, CALLOUT_MPSAFE);
350 
351 	frob_cfdrivervec(cfdriver_list_initial,
352 	    config_cfdriver_attach, NULL, "bootstrap", true);
353 	frob_cfattachvec(cfattachinit,
354 	    config_cfattach_attach, NULL, "bootstrap", true);
355 
356 	initcftable.ct_cfdata = cfdata;
357 	TAILQ_INSERT_TAIL(&allcftables, &initcftable, ct_list);
358 
359 	config_initialized = true;
360 }
361 
362 /*
363  * Init or fini drivers and attachments.  Either all or none
364  * are processed (via rollback).  It would be nice if this were
365  * atomic to outside consumers, but with the current state of
366  * locking ...
367  */
368 int
369 config_init_component(struct cfdriver * const *cfdriverv,
370 	const struct cfattachinit *cfattachv, struct cfdata *cfdatav)
371 {
372 	int error;
373 
374 	if ((error = frob_cfdrivervec(cfdriverv,
375 	    config_cfdriver_attach, config_cfdriver_detach, "init", false))!= 0)
376 		return error;
377 	if ((error = frob_cfattachvec(cfattachv,
378 	    config_cfattach_attach, config_cfattach_detach,
379 	    "init", false)) != 0) {
380 		frob_cfdrivervec(cfdriverv,
381 	            config_cfdriver_detach, NULL, "init rollback", true);
382 		return error;
383 	}
384 	if ((error = config_cfdata_attach(cfdatav, 1)) != 0) {
385 		frob_cfattachvec(cfattachv,
386 		    config_cfattach_detach, NULL, "init rollback", true);
387 		frob_cfdrivervec(cfdriverv,
388 	            config_cfdriver_detach, NULL, "init rollback", true);
389 		return error;
390 	}
391 
392 	return 0;
393 }
394 
395 int
396 config_fini_component(struct cfdriver * const *cfdriverv,
397 	const struct cfattachinit *cfattachv, struct cfdata *cfdatav)
398 {
399 	int error;
400 
401 	if ((error = config_cfdata_detach(cfdatav)) != 0)
402 		return error;
403 	if ((error = frob_cfattachvec(cfattachv,
404 	    config_cfattach_detach, config_cfattach_attach,
405 	    "fini", false)) != 0) {
406 		if (config_cfdata_attach(cfdatav, 0) != 0)
407 			panic("config_cfdata fini rollback failed");
408 		return error;
409 	}
410 	if ((error = frob_cfdrivervec(cfdriverv,
411 	    config_cfdriver_detach, config_cfdriver_attach,
412 	    "fini", false)) != 0) {
413 		frob_cfattachvec(cfattachv,
414 	            config_cfattach_attach, NULL, "fini rollback", true);
415 		if (config_cfdata_attach(cfdatav, 0) != 0)
416 			panic("config_cfdata fini rollback failed");
417 		return error;
418 	}
419 
420 	return 0;
421 }
422 
423 void
424 config_init_mi(void)
425 {
426 
427 	if (!config_initialized)
428 		config_init();
429 
430 	sysctl_detach_setup(NULL);
431 }
432 
433 void
434 config_deferred(device_t dev)
435 {
436 	config_process_deferred(&deferred_config_queue, dev);
437 	config_process_deferred(&interrupt_config_queue, dev);
438 	config_process_deferred(&mountroot_config_queue, dev);
439 }
440 
441 static void
442 config_interrupts_thread(void *cookie)
443 {
444 	struct deferred_config *dc;
445 
446 	while ((dc = TAILQ_FIRST(&interrupt_config_queue)) != NULL) {
447 		TAILQ_REMOVE(&interrupt_config_queue, dc, dc_queue);
448 		(*dc->dc_func)(dc->dc_dev);
449 		config_pending_decr(dc->dc_dev);
450 		kmem_free(dc, sizeof(*dc));
451 	}
452 	kthread_exit(0);
453 }
454 
455 void
456 config_create_interruptthreads(void)
457 {
458 	int i;
459 
460 	for (i = 0; i < interrupt_config_threads; i++) {
461 		(void)kthread_create(PRI_NONE, 0, NULL,
462 		    config_interrupts_thread, NULL, NULL, "configintr");
463 	}
464 }
465 
466 static void
467 config_mountroot_thread(void *cookie)
468 {
469 	struct deferred_config *dc;
470 
471 	while ((dc = TAILQ_FIRST(&mountroot_config_queue)) != NULL) {
472 		TAILQ_REMOVE(&mountroot_config_queue, dc, dc_queue);
473 		(*dc->dc_func)(dc->dc_dev);
474 		kmem_free(dc, sizeof(*dc));
475 	}
476 	kthread_exit(0);
477 }
478 
479 void
480 config_create_mountrootthreads(void)
481 {
482 	int i;
483 
484 	if (!root_is_mounted)
485 		root_is_mounted = true;
486 
487 	mountroot_config_lwpids_size = sizeof(mountroot_config_lwpids) *
488 				       mountroot_config_threads;
489 	mountroot_config_lwpids = kmem_alloc(mountroot_config_lwpids_size,
490 					     KM_NOSLEEP);
491 	KASSERT(mountroot_config_lwpids);
492 	for (i = 0; i < mountroot_config_threads; i++) {
493 		mountroot_config_lwpids[i] = 0;
494 		(void)kthread_create(PRI_NONE, KTHREAD_MUSTJOIN, NULL,
495 				     config_mountroot_thread, NULL,
496 				     &mountroot_config_lwpids[i],
497 				     "configroot");
498 	}
499 }
500 
501 void
502 config_finalize_mountroot(void)
503 {
504 	int i, error;
505 
506 	for (i = 0; i < mountroot_config_threads; i++) {
507 		if (mountroot_config_lwpids[i] == 0)
508 			continue;
509 
510 		error = kthread_join(mountroot_config_lwpids[i]);
511 		if (error)
512 			printf("%s: thread %x joined with error %d\n",
513 			       __func__, i, error);
514 	}
515 	kmem_free(mountroot_config_lwpids, mountroot_config_lwpids_size);
516 }
517 
518 /*
519  * Announce device attach/detach to userland listeners.
520  */
521 
522 int
523 no_devmon_insert(const char *name, prop_dictionary_t p)
524 {
525 
526 	return ENODEV;
527 }
528 
529 static void
530 devmon_report_device(device_t dev, bool isattach)
531 {
532 	prop_dictionary_t ev;
533 	const char *parent;
534 	const char *what;
535 	device_t pdev = device_parent(dev);
536 
537 	/* If currently no drvctl device, just return */
538 	if (devmon_insert_vec == no_devmon_insert)
539 		return;
540 
541 	ev = prop_dictionary_create();
542 	if (ev == NULL)
543 		return;
544 
545 	what = (isattach ? "device-attach" : "device-detach");
546 	parent = (pdev == NULL ? "root" : device_xname(pdev));
547 	if (!prop_dictionary_set_cstring(ev, "device", device_xname(dev)) ||
548 	    !prop_dictionary_set_cstring(ev, "parent", parent)) {
549 		prop_object_release(ev);
550 		return;
551 	}
552 
553 	if ((*devmon_insert_vec)(what, ev) != 0)
554 		prop_object_release(ev);
555 }
556 
557 /*
558  * Add a cfdriver to the system.
559  */
560 int
561 config_cfdriver_attach(struct cfdriver *cd)
562 {
563 	struct cfdriver *lcd;
564 
565 	/* Make sure this driver isn't already in the system. */
566 	LIST_FOREACH(lcd, &allcfdrivers, cd_list) {
567 		if (STREQ(lcd->cd_name, cd->cd_name))
568 			return EEXIST;
569 	}
570 
571 	LIST_INIT(&cd->cd_attach);
572 	LIST_INSERT_HEAD(&allcfdrivers, cd, cd_list);
573 
574 	return 0;
575 }
576 
577 /*
578  * Remove a cfdriver from the system.
579  */
580 int
581 config_cfdriver_detach(struct cfdriver *cd)
582 {
583 	struct alldevs_foray af;
584 	int i, rc = 0;
585 
586 	config_alldevs_enter(&af);
587 	/* Make sure there are no active instances. */
588 	for (i = 0; i < cd->cd_ndevs; i++) {
589 		if (cd->cd_devs[i] != NULL) {
590 			rc = EBUSY;
591 			break;
592 		}
593 	}
594 	config_alldevs_exit(&af);
595 
596 	if (rc != 0)
597 		return rc;
598 
599 	/* ...and no attachments loaded. */
600 	if (LIST_EMPTY(&cd->cd_attach) == 0)
601 		return EBUSY;
602 
603 	LIST_REMOVE(cd, cd_list);
604 
605 	KASSERT(cd->cd_devs == NULL);
606 
607 	return 0;
608 }
609 
610 /*
611  * Look up a cfdriver by name.
612  */
613 struct cfdriver *
614 config_cfdriver_lookup(const char *name)
615 {
616 	struct cfdriver *cd;
617 
618 	LIST_FOREACH(cd, &allcfdrivers, cd_list) {
619 		if (STREQ(cd->cd_name, name))
620 			return cd;
621 	}
622 
623 	return NULL;
624 }
625 
626 /*
627  * Add a cfattach to the specified driver.
628  */
629 int
630 config_cfattach_attach(const char *driver, struct cfattach *ca)
631 {
632 	struct cfattach *lca;
633 	struct cfdriver *cd;
634 
635 	cd = config_cfdriver_lookup(driver);
636 	if (cd == NULL)
637 		return ESRCH;
638 
639 	/* Make sure this attachment isn't already on this driver. */
640 	LIST_FOREACH(lca, &cd->cd_attach, ca_list) {
641 		if (STREQ(lca->ca_name, ca->ca_name))
642 			return EEXIST;
643 	}
644 
645 	LIST_INSERT_HEAD(&cd->cd_attach, ca, ca_list);
646 
647 	return 0;
648 }
649 
650 /*
651  * Remove a cfattach from the specified driver.
652  */
653 int
654 config_cfattach_detach(const char *driver, struct cfattach *ca)
655 {
656 	struct alldevs_foray af;
657 	struct cfdriver *cd;
658 	device_t dev;
659 	int i, rc = 0;
660 
661 	cd = config_cfdriver_lookup(driver);
662 	if (cd == NULL)
663 		return ESRCH;
664 
665 	config_alldevs_enter(&af);
666 	/* Make sure there are no active instances. */
667 	for (i = 0; i < cd->cd_ndevs; i++) {
668 		if ((dev = cd->cd_devs[i]) == NULL)
669 			continue;
670 		if (dev->dv_cfattach == ca) {
671 			rc = EBUSY;
672 			break;
673 		}
674 	}
675 	config_alldevs_exit(&af);
676 
677 	if (rc != 0)
678 		return rc;
679 
680 	LIST_REMOVE(ca, ca_list);
681 
682 	return 0;
683 }
684 
685 /*
686  * Look up a cfattach by name.
687  */
688 static struct cfattach *
689 config_cfattach_lookup_cd(struct cfdriver *cd, const char *atname)
690 {
691 	struct cfattach *ca;
692 
693 	LIST_FOREACH(ca, &cd->cd_attach, ca_list) {
694 		if (STREQ(ca->ca_name, atname))
695 			return ca;
696 	}
697 
698 	return NULL;
699 }
700 
701 /*
702  * Look up a cfattach by driver/attachment name.
703  */
704 struct cfattach *
705 config_cfattach_lookup(const char *name, const char *atname)
706 {
707 	struct cfdriver *cd;
708 
709 	cd = config_cfdriver_lookup(name);
710 	if (cd == NULL)
711 		return NULL;
712 
713 	return config_cfattach_lookup_cd(cd, atname);
714 }
715 
716 /*
717  * Apply the matching function and choose the best.  This is used
718  * a few times and we want to keep the code small.
719  */
720 static void
721 mapply(struct matchinfo *m, cfdata_t cf)
722 {
723 	int pri;
724 
725 	if (m->fn != NULL) {
726 		pri = (*m->fn)(m->parent, cf, m->locs, m->aux);
727 	} else {
728 		pri = config_match(m->parent, cf, m->aux);
729 	}
730 	if (pri > m->pri) {
731 		m->match = cf;
732 		m->pri = pri;
733 	}
734 }
735 
736 int
737 config_stdsubmatch(device_t parent, cfdata_t cf, const int *locs, void *aux)
738 {
739 	const struct cfiattrdata *ci;
740 	const struct cflocdesc *cl;
741 	int nlocs, i;
742 
743 	ci = cfiattr_lookup(cfdata_ifattr(cf), parent->dv_cfdriver);
744 	KASSERT(ci);
745 	nlocs = ci->ci_loclen;
746 	KASSERT(!nlocs || locs);
747 	for (i = 0; i < nlocs; i++) {
748 		cl = &ci->ci_locdesc[i];
749 		if (cl->cld_defaultstr != NULL &&
750 		    cf->cf_loc[i] == cl->cld_default)
751 			continue;
752 		if (cf->cf_loc[i] == locs[i])
753 			continue;
754 		return 0;
755 	}
756 
757 	return config_match(parent, cf, aux);
758 }
759 
760 /*
761  * Helper function: check whether the driver supports the interface attribute
762  * and return its descriptor structure.
763  */
764 static const struct cfiattrdata *
765 cfdriver_get_iattr(const struct cfdriver *cd, const char *ia)
766 {
767 	const struct cfiattrdata * const *cpp;
768 
769 	if (cd->cd_attrs == NULL)
770 		return 0;
771 
772 	for (cpp = cd->cd_attrs; *cpp; cpp++) {
773 		if (STREQ((*cpp)->ci_name, ia)) {
774 			/* Match. */
775 			return *cpp;
776 		}
777 	}
778 	return 0;
779 }
780 
781 /*
782  * Lookup an interface attribute description by name.
783  * If the driver is given, consider only its supported attributes.
784  */
785 const struct cfiattrdata *
786 cfiattr_lookup(const char *name, const struct cfdriver *cd)
787 {
788 	const struct cfdriver *d;
789 	const struct cfiattrdata *ia;
790 
791 	if (cd)
792 		return cfdriver_get_iattr(cd, name);
793 
794 	LIST_FOREACH(d, &allcfdrivers, cd_list) {
795 		ia = cfdriver_get_iattr(d, name);
796 		if (ia)
797 			return ia;
798 	}
799 	return 0;
800 }
801 
802 /*
803  * Determine if `parent' is a potential parent for a device spec based
804  * on `cfp'.
805  */
806 static int
807 cfparent_match(const device_t parent, const struct cfparent *cfp)
808 {
809 	struct cfdriver *pcd;
810 
811 	/* We don't match root nodes here. */
812 	if (cfp == NULL)
813 		return 0;
814 
815 	pcd = parent->dv_cfdriver;
816 	KASSERT(pcd != NULL);
817 
818 	/*
819 	 * First, ensure this parent has the correct interface
820 	 * attribute.
821 	 */
822 	if (!cfdriver_get_iattr(pcd, cfp->cfp_iattr))
823 		return 0;
824 
825 	/*
826 	 * If no specific parent device instance was specified (i.e.
827 	 * we're attaching to the attribute only), we're done!
828 	 */
829 	if (cfp->cfp_parent == NULL)
830 		return 1;
831 
832 	/*
833 	 * Check the parent device's name.
834 	 */
835 	if (STREQ(pcd->cd_name, cfp->cfp_parent) == 0)
836 		return 0;	/* not the same parent */
837 
838 	/*
839 	 * Make sure the unit number matches.
840 	 */
841 	if (cfp->cfp_unit == DVUNIT_ANY ||	/* wildcard */
842 	    cfp->cfp_unit == parent->dv_unit)
843 		return 1;
844 
845 	/* Unit numbers don't match. */
846 	return 0;
847 }
848 
849 /*
850  * Helper for config_cfdata_attach(): check all devices whether it could be
851  * parent any attachment in the config data table passed, and rescan.
852  */
853 static void
854 rescan_with_cfdata(const struct cfdata *cf)
855 {
856 	device_t d;
857 	const struct cfdata *cf1;
858 	deviter_t di;
859 
860 
861 	/*
862 	 * "alldevs" is likely longer than a modules's cfdata, so make it
863 	 * the outer loop.
864 	 */
865 	for (d = deviter_first(&di, 0); d != NULL; d = deviter_next(&di)) {
866 
867 		if (!(d->dv_cfattach->ca_rescan))
868 			continue;
869 
870 		for (cf1 = cf; cf1->cf_name; cf1++) {
871 
872 			if (!cfparent_match(d, cf1->cf_pspec))
873 				continue;
874 
875 			(*d->dv_cfattach->ca_rescan)(d,
876 				cfdata_ifattr(cf1), cf1->cf_loc);
877 
878 			config_deferred(d);
879 		}
880 	}
881 	deviter_release(&di);
882 }
883 
884 /*
885  * Attach a supplemental config data table and rescan potential
886  * parent devices if required.
887  */
888 int
889 config_cfdata_attach(cfdata_t cf, int scannow)
890 {
891 	struct cftable *ct;
892 
893 	ct = kmem_alloc(sizeof(*ct), KM_SLEEP);
894 	ct->ct_cfdata = cf;
895 	TAILQ_INSERT_TAIL(&allcftables, ct, ct_list);
896 
897 	if (scannow)
898 		rescan_with_cfdata(cf);
899 
900 	return 0;
901 }
902 
903 /*
904  * Helper for config_cfdata_detach: check whether a device is
905  * found through any attachment in the config data table.
906  */
907 static int
908 dev_in_cfdata(device_t d, cfdata_t cf)
909 {
910 	const struct cfdata *cf1;
911 
912 	for (cf1 = cf; cf1->cf_name; cf1++)
913 		if (d->dv_cfdata == cf1)
914 			return 1;
915 
916 	return 0;
917 }
918 
919 /*
920  * Detach a supplemental config data table. Detach all devices found
921  * through that table (and thus keeping references to it) before.
922  */
923 int
924 config_cfdata_detach(cfdata_t cf)
925 {
926 	device_t d;
927 	int error = 0;
928 	struct cftable *ct;
929 	deviter_t di;
930 
931 	for (d = deviter_first(&di, DEVITER_F_RW); d != NULL;
932 	     d = deviter_next(&di)) {
933 		if (!dev_in_cfdata(d, cf))
934 			continue;
935 		if ((error = config_detach(d, 0)) != 0)
936 			break;
937 	}
938 	deviter_release(&di);
939 	if (error) {
940 		aprint_error_dev(d, "unable to detach instance\n");
941 		return error;
942 	}
943 
944 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
945 		if (ct->ct_cfdata == cf) {
946 			TAILQ_REMOVE(&allcftables, ct, ct_list);
947 			kmem_free(ct, sizeof(*ct));
948 			return 0;
949 		}
950 	}
951 
952 	/* not found -- shouldn't happen */
953 	return EINVAL;
954 }
955 
956 /*
957  * Invoke the "match" routine for a cfdata entry on behalf of
958  * an external caller, usually a "submatch" routine.
959  */
960 int
961 config_match(device_t parent, cfdata_t cf, void *aux)
962 {
963 	struct cfattach *ca;
964 
965 	ca = config_cfattach_lookup(cf->cf_name, cf->cf_atname);
966 	if (ca == NULL) {
967 		/* No attachment for this entry, oh well. */
968 		return 0;
969 	}
970 
971 	return (*ca->ca_match)(parent, cf, aux);
972 }
973 
974 /*
975  * Iterate over all potential children of some device, calling the given
976  * function (default being the child's match function) for each one.
977  * Nonzero returns are matches; the highest value returned is considered
978  * the best match.  Return the `found child' if we got a match, or NULL
979  * otherwise.  The `aux' pointer is simply passed on through.
980  *
981  * Note that this function is designed so that it can be used to apply
982  * an arbitrary function to all potential children (its return value
983  * can be ignored).
984  */
985 cfdata_t
986 config_search_loc(cfsubmatch_t fn, device_t parent,
987 		  const char *ifattr, const int *locs, void *aux)
988 {
989 	struct cftable *ct;
990 	cfdata_t cf;
991 	struct matchinfo m;
992 
993 	KASSERT(config_initialized);
994 	KASSERT(!ifattr || cfdriver_get_iattr(parent->dv_cfdriver, ifattr));
995 
996 	m.fn = fn;
997 	m.parent = parent;
998 	m.locs = locs;
999 	m.aux = aux;
1000 	m.match = NULL;
1001 	m.pri = 0;
1002 
1003 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
1004 		for (cf = ct->ct_cfdata; cf->cf_name; cf++) {
1005 
1006 			/* We don't match root nodes here. */
1007 			if (!cf->cf_pspec)
1008 				continue;
1009 
1010 			/*
1011 			 * Skip cf if no longer eligible, otherwise scan
1012 			 * through parents for one matching `parent', and
1013 			 * try match function.
1014 			 */
1015 			if (cf->cf_fstate == FSTATE_FOUND)
1016 				continue;
1017 			if (cf->cf_fstate == FSTATE_DNOTFOUND ||
1018 			    cf->cf_fstate == FSTATE_DSTAR)
1019 				continue;
1020 
1021 			/*
1022 			 * If an interface attribute was specified,
1023 			 * consider only children which attach to
1024 			 * that attribute.
1025 			 */
1026 			if (ifattr && !STREQ(ifattr, cfdata_ifattr(cf)))
1027 				continue;
1028 
1029 			if (cfparent_match(parent, cf->cf_pspec))
1030 				mapply(&m, cf);
1031 		}
1032 	}
1033 	return m.match;
1034 }
1035 
1036 cfdata_t
1037 config_search_ia(cfsubmatch_t fn, device_t parent, const char *ifattr,
1038     void *aux)
1039 {
1040 
1041 	return config_search_loc(fn, parent, ifattr, NULL, aux);
1042 }
1043 
1044 /*
1045  * Find the given root device.
1046  * This is much like config_search, but there is no parent.
1047  * Don't bother with multiple cfdata tables; the root node
1048  * must always be in the initial table.
1049  */
1050 cfdata_t
1051 config_rootsearch(cfsubmatch_t fn, const char *rootname, void *aux)
1052 {
1053 	cfdata_t cf;
1054 	const short *p;
1055 	struct matchinfo m;
1056 
1057 	m.fn = fn;
1058 	m.parent = ROOT;
1059 	m.aux = aux;
1060 	m.match = NULL;
1061 	m.pri = 0;
1062 	m.locs = 0;
1063 	/*
1064 	 * Look at root entries for matching name.  We do not bother
1065 	 * with found-state here since only one root should ever be
1066 	 * searched (and it must be done first).
1067 	 */
1068 	for (p = cfroots; *p >= 0; p++) {
1069 		cf = &cfdata[*p];
1070 		if (strcmp(cf->cf_name, rootname) == 0)
1071 			mapply(&m, cf);
1072 	}
1073 	return m.match;
1074 }
1075 
1076 static const char * const msgs[3] = { "", " not configured\n", " unsupported\n" };
1077 
1078 /*
1079  * The given `aux' argument describes a device that has been found
1080  * on the given parent, but not necessarily configured.  Locate the
1081  * configuration data for that device (using the submatch function
1082  * provided, or using candidates' cd_match configuration driver
1083  * functions) and attach it, and return its device_t.  If the device was
1084  * not configured, call the given `print' function and return NULL.
1085  */
1086 device_t
1087 config_found_sm_loc(device_t parent,
1088 		const char *ifattr, const int *locs, void *aux,
1089 		cfprint_t print, cfsubmatch_t submatch)
1090 {
1091 	cfdata_t cf;
1092 
1093 	if ((cf = config_search_loc(submatch, parent, ifattr, locs, aux)))
1094 		return(config_attach_loc(parent, cf, locs, aux, print));
1095 	if (print) {
1096 		if (config_do_twiddle && cold)
1097 			twiddle();
1098 		aprint_normal("%s", msgs[(*print)(aux, device_xname(parent))]);
1099 	}
1100 
1101 	/*
1102 	 * This has the effect of mixing in a single timestamp to the
1103 	 * entropy pool.  Experiments indicate the estimator will almost
1104 	 * always attribute one bit of entropy to this sample; analysis
1105 	 * of device attach/detach timestamps on FreeBSD indicates 4
1106 	 * bits of entropy/sample so this seems appropriately conservative.
1107 	 */
1108 	rnd_add_uint32(&rnd_autoconf_source, 0);
1109 	return NULL;
1110 }
1111 
1112 device_t
1113 config_found_ia(device_t parent, const char *ifattr, void *aux,
1114     cfprint_t print)
1115 {
1116 
1117 	return config_found_sm_loc(parent, ifattr, NULL, aux, print, NULL);
1118 }
1119 
1120 device_t
1121 config_found(device_t parent, void *aux, cfprint_t print)
1122 {
1123 
1124 	return config_found_sm_loc(parent, NULL, NULL, aux, print, NULL);
1125 }
1126 
1127 /*
1128  * As above, but for root devices.
1129  */
1130 device_t
1131 config_rootfound(const char *rootname, void *aux)
1132 {
1133 	cfdata_t cf;
1134 
1135 	if ((cf = config_rootsearch(NULL, rootname, aux)) != NULL)
1136 		return config_attach(ROOT, cf, aux, NULL);
1137 	aprint_error("root device %s not configured\n", rootname);
1138 	return NULL;
1139 }
1140 
1141 /* just like sprintf(buf, "%d") except that it works from the end */
1142 static char *
1143 number(char *ep, int n)
1144 {
1145 
1146 	*--ep = 0;
1147 	while (n >= 10) {
1148 		*--ep = (n % 10) + '0';
1149 		n /= 10;
1150 	}
1151 	*--ep = n + '0';
1152 	return ep;
1153 }
1154 
1155 /*
1156  * Expand the size of the cd_devs array if necessary.
1157  *
1158  * The caller must hold alldevs_lock. config_makeroom() may release and
1159  * re-acquire alldevs_lock, so callers should re-check conditions such
1160  * as alldevs_nwrite == 0 and alldevs_nread == 0 when config_makeroom()
1161  * returns.
1162  */
1163 static void
1164 config_makeroom(int n, struct cfdriver *cd)
1165 {
1166 	int ondevs, nndevs;
1167 	device_t *osp, *nsp;
1168 
1169 	KASSERT(mutex_owned(&alldevs_lock));
1170 	alldevs_nwrite++;
1171 
1172 	for (nndevs = MAX(4, cd->cd_ndevs); nndevs <= n; nndevs += nndevs)
1173 		;
1174 
1175 	while (n >= cd->cd_ndevs) {
1176 		/*
1177 		 * Need to expand the array.
1178 		 */
1179 		ondevs = cd->cd_ndevs;
1180 		osp = cd->cd_devs;
1181 
1182 		/*
1183 		 * Release alldevs_lock around allocation, which may
1184 		 * sleep.
1185 		 */
1186 		mutex_exit(&alldevs_lock);
1187 		nsp = kmem_alloc(sizeof(device_t[nndevs]), KM_SLEEP);
1188 		mutex_enter(&alldevs_lock);
1189 
1190 		/*
1191 		 * If another thread moved the array while we did
1192 		 * not hold alldevs_lock, try again.
1193 		 */
1194 		if (cd->cd_devs != osp) {
1195 			mutex_exit(&alldevs_lock);
1196 			kmem_free(nsp, sizeof(device_t[nndevs]));
1197 			mutex_enter(&alldevs_lock);
1198 			continue;
1199 		}
1200 
1201 		memset(nsp + ondevs, 0, sizeof(device_t[nndevs - ondevs]));
1202 		if (ondevs != 0)
1203 			memcpy(nsp, cd->cd_devs, sizeof(device_t[ondevs]));
1204 
1205 		cd->cd_ndevs = nndevs;
1206 		cd->cd_devs = nsp;
1207 		if (ondevs != 0) {
1208 			mutex_exit(&alldevs_lock);
1209 			kmem_free(osp, sizeof(device_t[ondevs]));
1210 			mutex_enter(&alldevs_lock);
1211 		}
1212 	}
1213 	KASSERT(mutex_owned(&alldevs_lock));
1214 	alldevs_nwrite--;
1215 }
1216 
1217 /*
1218  * Put dev into the devices list.
1219  */
1220 static void
1221 config_devlink(device_t dev)
1222 {
1223 
1224 	mutex_enter(&alldevs_lock);
1225 
1226 	KASSERT(device_cfdriver(dev)->cd_devs[dev->dv_unit] == dev);
1227 
1228 	dev->dv_add_gen = alldevs_gen;
1229 	/* It is safe to add a device to the tail of the list while
1230 	 * readers and writers are in the list.
1231 	 */
1232 	TAILQ_INSERT_TAIL(&alldevs, dev, dv_list);
1233 	mutex_exit(&alldevs_lock);
1234 }
1235 
1236 static void
1237 config_devfree(device_t dev)
1238 {
1239 	int priv = (dev->dv_flags & DVF_PRIV_ALLOC);
1240 
1241 	if (dev->dv_cfattach->ca_devsize > 0)
1242 		kmem_free(dev->dv_private, dev->dv_cfattach->ca_devsize);
1243 	if (priv)
1244 		kmem_free(dev, sizeof(*dev));
1245 }
1246 
1247 /*
1248  * Caller must hold alldevs_lock.
1249  */
1250 static void
1251 config_devunlink(device_t dev, struct devicelist *garbage)
1252 {
1253 	struct device_garbage *dg = &dev->dv_garbage;
1254 	cfdriver_t cd = device_cfdriver(dev);
1255 	int i;
1256 
1257 	KASSERT(mutex_owned(&alldevs_lock));
1258 
1259  	/* Unlink from device list.  Link to garbage list. */
1260 	TAILQ_REMOVE(&alldevs, dev, dv_list);
1261 	TAILQ_INSERT_TAIL(garbage, dev, dv_list);
1262 
1263 	/* Remove from cfdriver's array. */
1264 	cd->cd_devs[dev->dv_unit] = NULL;
1265 
1266 	/*
1267 	 * If the device now has no units in use, unlink its softc array.
1268 	 */
1269 	for (i = 0; i < cd->cd_ndevs; i++) {
1270 		if (cd->cd_devs[i] != NULL)
1271 			break;
1272 	}
1273 	/* Nothing found.  Unlink, now.  Deallocate, later. */
1274 	if (i == cd->cd_ndevs) {
1275 		dg->dg_ndevs = cd->cd_ndevs;
1276 		dg->dg_devs = cd->cd_devs;
1277 		cd->cd_devs = NULL;
1278 		cd->cd_ndevs = 0;
1279 	}
1280 }
1281 
1282 static void
1283 config_devdelete(device_t dev)
1284 {
1285 	struct device_garbage *dg = &dev->dv_garbage;
1286 	device_lock_t dvl = device_getlock(dev);
1287 
1288 	if (dg->dg_devs != NULL)
1289 		kmem_free(dg->dg_devs, sizeof(device_t[dg->dg_ndevs]));
1290 
1291 	cv_destroy(&dvl->dvl_cv);
1292 	mutex_destroy(&dvl->dvl_mtx);
1293 
1294 	KASSERT(dev->dv_properties != NULL);
1295 	prop_object_release(dev->dv_properties);
1296 
1297 	if (dev->dv_activity_handlers)
1298 		panic("%s with registered handlers", __func__);
1299 
1300 	if (dev->dv_locators) {
1301 		size_t amount = *--dev->dv_locators;
1302 		kmem_free(dev->dv_locators, amount);
1303 	}
1304 
1305 	config_devfree(dev);
1306 }
1307 
1308 static int
1309 config_unit_nextfree(cfdriver_t cd, cfdata_t cf)
1310 {
1311 	int unit;
1312 
1313 	if (cf->cf_fstate == FSTATE_STAR) {
1314 		for (unit = cf->cf_unit; unit < cd->cd_ndevs; unit++)
1315 			if (cd->cd_devs[unit] == NULL)
1316 				break;
1317 		/*
1318 		 * unit is now the unit of the first NULL device pointer,
1319 		 * or max(cd->cd_ndevs,cf->cf_unit).
1320 		 */
1321 	} else {
1322 		unit = cf->cf_unit;
1323 		if (unit < cd->cd_ndevs && cd->cd_devs[unit] != NULL)
1324 			unit = -1;
1325 	}
1326 	return unit;
1327 }
1328 
1329 static int
1330 config_unit_alloc(device_t dev, cfdriver_t cd, cfdata_t cf)
1331 {
1332 	struct alldevs_foray af;
1333 	int unit;
1334 
1335 	config_alldevs_enter(&af);
1336 	for (;;) {
1337 		unit = config_unit_nextfree(cd, cf);
1338 		if (unit == -1)
1339 			break;
1340 		if (unit < cd->cd_ndevs) {
1341 			cd->cd_devs[unit] = dev;
1342 			dev->dv_unit = unit;
1343 			break;
1344 		}
1345 		config_makeroom(unit, cd);
1346 	}
1347 	config_alldevs_exit(&af);
1348 
1349 	return unit;
1350 }
1351 
1352 static device_t
1353 config_devalloc(const device_t parent, const cfdata_t cf, const int *locs)
1354 {
1355 	cfdriver_t cd;
1356 	cfattach_t ca;
1357 	size_t lname, lunit;
1358 	const char *xunit;
1359 	int myunit;
1360 	char num[10];
1361 	device_t dev;
1362 	void *dev_private;
1363 	const struct cfiattrdata *ia;
1364 	device_lock_t dvl;
1365 
1366 	cd = config_cfdriver_lookup(cf->cf_name);
1367 	if (cd == NULL)
1368 		return NULL;
1369 
1370 	ca = config_cfattach_lookup_cd(cd, cf->cf_atname);
1371 	if (ca == NULL)
1372 		return NULL;
1373 
1374 	/* get memory for all device vars */
1375 	KASSERTMSG((ca->ca_flags & DVF_PRIV_ALLOC)
1376 	    || ca->ca_devsize >= sizeof(struct device),
1377 	    "%s: %s (%zu < %zu)", __func__, cf->cf_atname, ca->ca_devsize,
1378 	    sizeof(struct device));
1379 	if (ca->ca_devsize > 0) {
1380 		dev_private = kmem_zalloc(ca->ca_devsize, KM_SLEEP);
1381 	} else {
1382 		KASSERT(ca->ca_flags & DVF_PRIV_ALLOC);
1383 		dev_private = NULL;
1384 	}
1385 
1386 	if ((ca->ca_flags & DVF_PRIV_ALLOC) != 0) {
1387 		dev = kmem_zalloc(sizeof(*dev), KM_SLEEP);
1388 	} else {
1389 		dev = dev_private;
1390 #ifdef DIAGNOSTIC
1391 		printf("%s has not been converted to device_t\n", cd->cd_name);
1392 #endif
1393 		KASSERT(dev != NULL);
1394 	}
1395 	dev->dv_class = cd->cd_class;
1396 	dev->dv_cfdata = cf;
1397 	dev->dv_cfdriver = cd;
1398 	dev->dv_cfattach = ca;
1399 	dev->dv_activity_count = 0;
1400 	dev->dv_activity_handlers = NULL;
1401 	dev->dv_private = dev_private;
1402 	dev->dv_flags = ca->ca_flags;	/* inherit flags from class */
1403 
1404 	myunit = config_unit_alloc(dev, cd, cf);
1405 	if (myunit == -1) {
1406 		config_devfree(dev);
1407 		return NULL;
1408 	}
1409 
1410 	/* compute length of name and decimal expansion of unit number */
1411 	lname = strlen(cd->cd_name);
1412 	xunit = number(&num[sizeof(num)], myunit);
1413 	lunit = &num[sizeof(num)] - xunit;
1414 	if (lname + lunit > sizeof(dev->dv_xname))
1415 		panic("config_devalloc: device name too long");
1416 
1417 	dvl = device_getlock(dev);
1418 
1419 	mutex_init(&dvl->dvl_mtx, MUTEX_DEFAULT, IPL_NONE);
1420 	cv_init(&dvl->dvl_cv, "pmfsusp");
1421 
1422 	memcpy(dev->dv_xname, cd->cd_name, lname);
1423 	memcpy(dev->dv_xname + lname, xunit, lunit);
1424 	dev->dv_parent = parent;
1425 	if (parent != NULL)
1426 		dev->dv_depth = parent->dv_depth + 1;
1427 	else
1428 		dev->dv_depth = 0;
1429 	dev->dv_flags |= DVF_ACTIVE;	/* always initially active */
1430 	if (locs) {
1431 		KASSERT(parent); /* no locators at root */
1432 		ia = cfiattr_lookup(cfdata_ifattr(cf), parent->dv_cfdriver);
1433 		dev->dv_locators =
1434 		    kmem_alloc(sizeof(int [ia->ci_loclen + 1]), KM_SLEEP);
1435 		*dev->dv_locators++ = sizeof(int [ia->ci_loclen + 1]);
1436 		memcpy(dev->dv_locators, locs, sizeof(int [ia->ci_loclen]));
1437 	}
1438 	dev->dv_properties = prop_dictionary_create();
1439 	KASSERT(dev->dv_properties != NULL);
1440 
1441 	prop_dictionary_set_cstring_nocopy(dev->dv_properties,
1442 	    "device-driver", dev->dv_cfdriver->cd_name);
1443 	prop_dictionary_set_uint16(dev->dv_properties,
1444 	    "device-unit", dev->dv_unit);
1445 	if (parent != NULL) {
1446 		prop_dictionary_set_cstring(dev->dv_properties,
1447 		    "device-parent", device_xname(parent));
1448 	}
1449 
1450 	if (dev->dv_cfdriver->cd_attrs != NULL)
1451 		config_add_attrib_dict(dev);
1452 
1453 	return dev;
1454 }
1455 
1456 /*
1457  * Create an array of device attach attributes and add it
1458  * to the device's dv_properties dictionary.
1459  *
1460  * <key>interface-attributes</key>
1461  * <array>
1462  *    <dict>
1463  *       <key>attribute-name</key>
1464  *       <string>foo</string>
1465  *       <key>locators</key>
1466  *       <array>
1467  *          <dict>
1468  *             <key>loc-name</key>
1469  *             <string>foo-loc1</string>
1470  *          </dict>
1471  *          <dict>
1472  *             <key>loc-name</key>
1473  *             <string>foo-loc2</string>
1474  *             <key>default</key>
1475  *             <string>foo-loc2-default</string>
1476  *          </dict>
1477  *          ...
1478  *       </array>
1479  *    </dict>
1480  *    ...
1481  * </array>
1482  */
1483 
1484 static void
1485 config_add_attrib_dict(device_t dev)
1486 {
1487 	int i, j;
1488 	const struct cfiattrdata *ci;
1489 	prop_dictionary_t attr_dict, loc_dict;
1490 	prop_array_t attr_array, loc_array;
1491 
1492 	if ((attr_array = prop_array_create()) == NULL)
1493 		return;
1494 
1495 	for (i = 0; ; i++) {
1496 		if ((ci = dev->dv_cfdriver->cd_attrs[i]) == NULL)
1497 			break;
1498 		if ((attr_dict = prop_dictionary_create()) == NULL)
1499 			break;
1500 		prop_dictionary_set_cstring_nocopy(attr_dict, "attribute-name",
1501 		    ci->ci_name);
1502 
1503 		/* Create an array of the locator names and defaults */
1504 
1505 		if (ci->ci_loclen != 0 &&
1506 		    (loc_array = prop_array_create()) != NULL) {
1507 			for (j = 0; j < ci->ci_loclen; j++) {
1508 				loc_dict = prop_dictionary_create();
1509 				if (loc_dict == NULL)
1510 					continue;
1511 				prop_dictionary_set_cstring_nocopy(loc_dict,
1512 				    "loc-name", ci->ci_locdesc[j].cld_name);
1513 				if (ci->ci_locdesc[j].cld_defaultstr != NULL)
1514 					prop_dictionary_set_cstring_nocopy(
1515 					    loc_dict, "default",
1516 					    ci->ci_locdesc[j].cld_defaultstr);
1517 				prop_array_set(loc_array, j, loc_dict);
1518 				prop_object_release(loc_dict);
1519 			}
1520 			prop_dictionary_set_and_rel(attr_dict, "locators",
1521 			    loc_array);
1522 		}
1523 		prop_array_add(attr_array, attr_dict);
1524 		prop_object_release(attr_dict);
1525 	}
1526 	if (i == 0)
1527 		prop_object_release(attr_array);
1528 	else
1529 		prop_dictionary_set_and_rel(dev->dv_properties,
1530 		    "interface-attributes", attr_array);
1531 
1532 	return;
1533 }
1534 
1535 /*
1536  * Attach a found device.
1537  */
1538 device_t
1539 config_attach_loc(device_t parent, cfdata_t cf,
1540 	const int *locs, void *aux, cfprint_t print)
1541 {
1542 	device_t dev;
1543 	struct cftable *ct;
1544 	const char *drvname;
1545 
1546 	dev = config_devalloc(parent, cf, locs);
1547 	if (!dev)
1548 		panic("config_attach: allocation of device softc failed");
1549 
1550 	/* XXX redundant - see below? */
1551 	if (cf->cf_fstate != FSTATE_STAR) {
1552 		KASSERT(cf->cf_fstate == FSTATE_NOTFOUND);
1553 		cf->cf_fstate = FSTATE_FOUND;
1554 	}
1555 
1556 	config_devlink(dev);
1557 
1558 	if (config_do_twiddle && cold)
1559 		twiddle();
1560 	else
1561 		aprint_naive("Found ");
1562 	/*
1563 	 * We want the next two printfs for normal, verbose, and quiet,
1564 	 * but not silent (in which case, we're twiddling, instead).
1565 	 */
1566 	if (parent == ROOT) {
1567 		aprint_naive("%s (root)", device_xname(dev));
1568 		aprint_normal("%s (root)", device_xname(dev));
1569 	} else {
1570 		aprint_naive("%s at %s", device_xname(dev),
1571 		    device_xname(parent));
1572 		aprint_normal("%s at %s", device_xname(dev),
1573 		    device_xname(parent));
1574 		if (print)
1575 			(void) (*print)(aux, NULL);
1576 	}
1577 
1578 	/*
1579 	 * Before attaching, clobber any unfound devices that are
1580 	 * otherwise identical.
1581 	 * XXX code above is redundant?
1582 	 */
1583 	drvname = dev->dv_cfdriver->cd_name;
1584 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
1585 		for (cf = ct->ct_cfdata; cf->cf_name; cf++) {
1586 			if (STREQ(cf->cf_name, drvname) &&
1587 			    cf->cf_unit == dev->dv_unit) {
1588 				if (cf->cf_fstate == FSTATE_NOTFOUND)
1589 					cf->cf_fstate = FSTATE_FOUND;
1590 			}
1591 		}
1592 	}
1593 	device_register(dev, aux);
1594 
1595 	/* Let userland know */
1596 	devmon_report_device(dev, true);
1597 
1598 	(*dev->dv_cfattach->ca_attach)(parent, dev, aux);
1599 
1600 	if (!device_pmf_is_registered(dev))
1601 		aprint_debug_dev(dev, "WARNING: power management not "
1602 		    "supported\n");
1603 
1604 	config_process_deferred(&deferred_config_queue, dev);
1605 
1606 	device_register_post_config(dev, aux);
1607 	return dev;
1608 }
1609 
1610 device_t
1611 config_attach(device_t parent, cfdata_t cf, void *aux, cfprint_t print)
1612 {
1613 
1614 	return config_attach_loc(parent, cf, NULL, aux, print);
1615 }
1616 
1617 /*
1618  * As above, but for pseudo-devices.  Pseudo-devices attached in this
1619  * way are silently inserted into the device tree, and their children
1620  * attached.
1621  *
1622  * Note that because pseudo-devices are attached silently, any information
1623  * the attach routine wishes to print should be prefixed with the device
1624  * name by the attach routine.
1625  */
1626 device_t
1627 config_attach_pseudo(cfdata_t cf)
1628 {
1629 	device_t dev;
1630 
1631 	dev = config_devalloc(ROOT, cf, NULL);
1632 	if (!dev)
1633 		return NULL;
1634 
1635 	/* XXX mark busy in cfdata */
1636 
1637 	if (cf->cf_fstate != FSTATE_STAR) {
1638 		KASSERT(cf->cf_fstate == FSTATE_NOTFOUND);
1639 		cf->cf_fstate = FSTATE_FOUND;
1640 	}
1641 
1642 	config_devlink(dev);
1643 
1644 #if 0	/* XXXJRT not yet */
1645 	device_register(dev, NULL);	/* like a root node */
1646 #endif
1647 
1648 	/* Let userland know */
1649 	devmon_report_device(dev, true);
1650 
1651 	(*dev->dv_cfattach->ca_attach)(ROOT, dev, NULL);
1652 
1653 	config_process_deferred(&deferred_config_queue, dev);
1654 	return dev;
1655 }
1656 
1657 /*
1658  * Caller must hold alldevs_lock.
1659  */
1660 static void
1661 config_collect_garbage(struct devicelist *garbage)
1662 {
1663 	device_t dv;
1664 
1665 	KASSERT(!cpu_intr_p());
1666 	KASSERT(!cpu_softintr_p());
1667 	KASSERT(mutex_owned(&alldevs_lock));
1668 
1669 	while (alldevs_nwrite == 0 && alldevs_nread == 0 && alldevs_garbage) {
1670 		TAILQ_FOREACH(dv, &alldevs, dv_list) {
1671 			if (dv->dv_del_gen != 0)
1672 				break;
1673 		}
1674 		if (dv == NULL) {
1675 			alldevs_garbage = false;
1676 			break;
1677 		}
1678 		config_devunlink(dv, garbage);
1679 	}
1680 	KASSERT(mutex_owned(&alldevs_lock));
1681 }
1682 
1683 static void
1684 config_dump_garbage(struct devicelist *garbage)
1685 {
1686 	device_t dv;
1687 
1688 	while ((dv = TAILQ_FIRST(garbage)) != NULL) {
1689 		TAILQ_REMOVE(garbage, dv, dv_list);
1690 		config_devdelete(dv);
1691 	}
1692 }
1693 
1694 /*
1695  * Detach a device.  Optionally forced (e.g. because of hardware
1696  * removal) and quiet.  Returns zero if successful, non-zero
1697  * (an error code) otherwise.
1698  *
1699  * Note that this code wants to be run from a process context, so
1700  * that the detach can sleep to allow processes which have a device
1701  * open to run and unwind their stacks.
1702  */
1703 int
1704 config_detach(device_t dev, int flags)
1705 {
1706 	struct alldevs_foray af;
1707 	struct cftable *ct;
1708 	cfdata_t cf;
1709 	const struct cfattach *ca;
1710 	struct cfdriver *cd;
1711 	device_t d __diagused;
1712 	int rv = 0;
1713 
1714 	cf = dev->dv_cfdata;
1715 	KASSERTMSG((cf == NULL || cf->cf_fstate == FSTATE_FOUND ||
1716 		cf->cf_fstate == FSTATE_STAR),
1717 	    "config_detach: %s: bad device fstate: %d",
1718 	    device_xname(dev), cf ? cf->cf_fstate : -1);
1719 
1720 	cd = dev->dv_cfdriver;
1721 	KASSERT(cd != NULL);
1722 
1723 	ca = dev->dv_cfattach;
1724 	KASSERT(ca != NULL);
1725 
1726 	mutex_enter(&alldevs_lock);
1727 	if (dev->dv_del_gen != 0) {
1728 		mutex_exit(&alldevs_lock);
1729 #ifdef DIAGNOSTIC
1730 		printf("%s: %s is already detached\n", __func__,
1731 		    device_xname(dev));
1732 #endif /* DIAGNOSTIC */
1733 		return ENOENT;
1734 	}
1735 	alldevs_nwrite++;
1736 	mutex_exit(&alldevs_lock);
1737 
1738 	if (!detachall &&
1739 	    (flags & (DETACH_SHUTDOWN|DETACH_FORCE)) == DETACH_SHUTDOWN &&
1740 	    (dev->dv_flags & DVF_DETACH_SHUTDOWN) == 0) {
1741 		rv = EOPNOTSUPP;
1742 	} else if (ca->ca_detach != NULL) {
1743 		rv = (*ca->ca_detach)(dev, flags);
1744 	} else
1745 		rv = EOPNOTSUPP;
1746 
1747 	/*
1748 	 * If it was not possible to detach the device, then we either
1749 	 * panic() (for the forced but failed case), or return an error.
1750 	 *
1751 	 * If it was possible to detach the device, ensure that the
1752 	 * device is deactivated.
1753 	 */
1754 	if (rv == 0)
1755 		dev->dv_flags &= ~DVF_ACTIVE;
1756 	else if ((flags & DETACH_FORCE) == 0)
1757 		goto out;
1758 	else {
1759 		panic("config_detach: forced detach of %s failed (%d)",
1760 		    device_xname(dev), rv);
1761 	}
1762 
1763 	/*
1764 	 * The device has now been successfully detached.
1765 	 */
1766 
1767 	/* Let userland know */
1768 	devmon_report_device(dev, false);
1769 
1770 #ifdef DIAGNOSTIC
1771 	/*
1772 	 * Sanity: If you're successfully detached, you should have no
1773 	 * children.  (Note that because children must be attached
1774 	 * after parents, we only need to search the latter part of
1775 	 * the list.)
1776 	 */
1777 	for (d = TAILQ_NEXT(dev, dv_list); d != NULL;
1778 	    d = TAILQ_NEXT(d, dv_list)) {
1779 		if (d->dv_parent == dev && d->dv_del_gen == 0) {
1780 			printf("config_detach: detached device %s"
1781 			    " has children %s\n", device_xname(dev),
1782 			    device_xname(d));
1783 			panic("config_detach");
1784 		}
1785 	}
1786 #endif
1787 
1788 	/* notify the parent that the child is gone */
1789 	if (dev->dv_parent) {
1790 		device_t p = dev->dv_parent;
1791 		if (p->dv_cfattach->ca_childdetached)
1792 			(*p->dv_cfattach->ca_childdetached)(p, dev);
1793 	}
1794 
1795 	/*
1796 	 * Mark cfdata to show that the unit can be reused, if possible.
1797 	 */
1798 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
1799 		for (cf = ct->ct_cfdata; cf->cf_name; cf++) {
1800 			if (STREQ(cf->cf_name, cd->cd_name)) {
1801 				if (cf->cf_fstate == FSTATE_FOUND &&
1802 				    cf->cf_unit == dev->dv_unit)
1803 					cf->cf_fstate = FSTATE_NOTFOUND;
1804 			}
1805 		}
1806 	}
1807 
1808 	if (dev->dv_cfdata != NULL && (flags & DETACH_QUIET) == 0)
1809 		aprint_normal_dev(dev, "detached\n");
1810 
1811 out:
1812 	config_alldevs_enter(&af);
1813 	KASSERT(alldevs_nwrite != 0);
1814 	--alldevs_nwrite;
1815 	if (rv == 0 && dev->dv_del_gen == 0) {
1816 		if (alldevs_nwrite == 0 && alldevs_nread == 0)
1817 			config_devunlink(dev, &af.af_garbage);
1818 		else {
1819 			dev->dv_del_gen = alldevs_gen;
1820 			alldevs_garbage = true;
1821 		}
1822 	}
1823 	config_alldevs_exit(&af);
1824 
1825 	return rv;
1826 }
1827 
1828 int
1829 config_detach_children(device_t parent, int flags)
1830 {
1831 	device_t dv;
1832 	deviter_t di;
1833 	int error = 0;
1834 
1835 	for (dv = deviter_first(&di, DEVITER_F_RW); dv != NULL;
1836 	     dv = deviter_next(&di)) {
1837 		if (device_parent(dv) != parent)
1838 			continue;
1839 		if ((error = config_detach(dv, flags)) != 0)
1840 			break;
1841 	}
1842 	deviter_release(&di);
1843 	return error;
1844 }
1845 
1846 device_t
1847 shutdown_first(struct shutdown_state *s)
1848 {
1849 	if (!s->initialized) {
1850 		deviter_init(&s->di, DEVITER_F_SHUTDOWN|DEVITER_F_LEAVES_FIRST);
1851 		s->initialized = true;
1852 	}
1853 	return shutdown_next(s);
1854 }
1855 
1856 device_t
1857 shutdown_next(struct shutdown_state *s)
1858 {
1859 	device_t dv;
1860 
1861 	while ((dv = deviter_next(&s->di)) != NULL && !device_is_active(dv))
1862 		;
1863 
1864 	if (dv == NULL)
1865 		s->initialized = false;
1866 
1867 	return dv;
1868 }
1869 
1870 bool
1871 config_detach_all(int how)
1872 {
1873 	static struct shutdown_state s;
1874 	device_t curdev;
1875 	bool progress = false;
1876 	int flags;
1877 
1878 	if ((how & (RB_NOSYNC|RB_DUMP)) != 0)
1879 		return false;
1880 
1881 	if ((how & RB_POWERDOWN) == RB_POWERDOWN)
1882 		flags = DETACH_SHUTDOWN | DETACH_POWEROFF;
1883 	else
1884 		flags = DETACH_SHUTDOWN;
1885 
1886 	for (curdev = shutdown_first(&s); curdev != NULL;
1887 	     curdev = shutdown_next(&s)) {
1888 		aprint_debug(" detaching %s, ", device_xname(curdev));
1889 		if (config_detach(curdev, flags) == 0) {
1890 			progress = true;
1891 			aprint_debug("success.");
1892 		} else
1893 			aprint_debug("failed.");
1894 	}
1895 	return progress;
1896 }
1897 
1898 static bool
1899 device_is_ancestor_of(device_t ancestor, device_t descendant)
1900 {
1901 	device_t dv;
1902 
1903 	for (dv = descendant; dv != NULL; dv = device_parent(dv)) {
1904 		if (device_parent(dv) == ancestor)
1905 			return true;
1906 	}
1907 	return false;
1908 }
1909 
1910 int
1911 config_deactivate(device_t dev)
1912 {
1913 	deviter_t di;
1914 	const struct cfattach *ca;
1915 	device_t descendant;
1916 	int s, rv = 0, oflags;
1917 
1918 	for (descendant = deviter_first(&di, DEVITER_F_ROOT_FIRST);
1919 	     descendant != NULL;
1920 	     descendant = deviter_next(&di)) {
1921 		if (dev != descendant &&
1922 		    !device_is_ancestor_of(dev, descendant))
1923 			continue;
1924 
1925 		if ((descendant->dv_flags & DVF_ACTIVE) == 0)
1926 			continue;
1927 
1928 		ca = descendant->dv_cfattach;
1929 		oflags = descendant->dv_flags;
1930 
1931 		descendant->dv_flags &= ~DVF_ACTIVE;
1932 		if (ca->ca_activate == NULL)
1933 			continue;
1934 		s = splhigh();
1935 		rv = (*ca->ca_activate)(descendant, DVACT_DEACTIVATE);
1936 		splx(s);
1937 		if (rv != 0)
1938 			descendant->dv_flags = oflags;
1939 	}
1940 	deviter_release(&di);
1941 	return rv;
1942 }
1943 
1944 /*
1945  * Defer the configuration of the specified device until all
1946  * of its parent's devices have been attached.
1947  */
1948 void
1949 config_defer(device_t dev, void (*func)(device_t))
1950 {
1951 	struct deferred_config *dc;
1952 
1953 	if (dev->dv_parent == NULL)
1954 		panic("config_defer: can't defer config of a root device");
1955 
1956 #ifdef DIAGNOSTIC
1957 	TAILQ_FOREACH(dc, &deferred_config_queue, dc_queue) {
1958 		if (dc->dc_dev == dev)
1959 			panic("config_defer: deferred twice");
1960 	}
1961 #endif
1962 
1963 	dc = kmem_alloc(sizeof(*dc), KM_SLEEP);
1964 	dc->dc_dev = dev;
1965 	dc->dc_func = func;
1966 	TAILQ_INSERT_TAIL(&deferred_config_queue, dc, dc_queue);
1967 	config_pending_incr(dev);
1968 }
1969 
1970 /*
1971  * Defer some autoconfiguration for a device until after interrupts
1972  * are enabled.
1973  */
1974 void
1975 config_interrupts(device_t dev, void (*func)(device_t))
1976 {
1977 	struct deferred_config *dc;
1978 
1979 	/*
1980 	 * If interrupts are enabled, callback now.
1981 	 */
1982 	if (cold == 0) {
1983 		(*func)(dev);
1984 		return;
1985 	}
1986 
1987 #ifdef DIAGNOSTIC
1988 	TAILQ_FOREACH(dc, &interrupt_config_queue, dc_queue) {
1989 		if (dc->dc_dev == dev)
1990 			panic("config_interrupts: deferred twice");
1991 	}
1992 #endif
1993 
1994 	dc = kmem_alloc(sizeof(*dc), KM_SLEEP);
1995 	dc->dc_dev = dev;
1996 	dc->dc_func = func;
1997 	TAILQ_INSERT_TAIL(&interrupt_config_queue, dc, dc_queue);
1998 	config_pending_incr(dev);
1999 }
2000 
2001 /*
2002  * Defer some autoconfiguration for a device until after root file system
2003  * is mounted (to load firmware etc).
2004  */
2005 void
2006 config_mountroot(device_t dev, void (*func)(device_t))
2007 {
2008 	struct deferred_config *dc;
2009 
2010 	/*
2011 	 * If root file system is mounted, callback now.
2012 	 */
2013 	if (root_is_mounted) {
2014 		(*func)(dev);
2015 		return;
2016 	}
2017 
2018 #ifdef DIAGNOSTIC
2019 	TAILQ_FOREACH(dc, &mountroot_config_queue, dc_queue) {
2020 		if (dc->dc_dev == dev)
2021 			panic("%s: deferred twice", __func__);
2022 	}
2023 #endif
2024 
2025 	dc = kmem_alloc(sizeof(*dc), KM_SLEEP);
2026 	dc->dc_dev = dev;
2027 	dc->dc_func = func;
2028 	TAILQ_INSERT_TAIL(&mountroot_config_queue, dc, dc_queue);
2029 }
2030 
2031 /*
2032  * Process a deferred configuration queue.
2033  */
2034 static void
2035 config_process_deferred(struct deferred_config_head *queue, device_t parent)
2036 {
2037 	struct deferred_config *dc, *ndc;
2038 
2039 	for (dc = TAILQ_FIRST(queue); dc != NULL; dc = ndc) {
2040 		ndc = TAILQ_NEXT(dc, dc_queue);
2041 		if (parent == NULL || dc->dc_dev->dv_parent == parent) {
2042 			TAILQ_REMOVE(queue, dc, dc_queue);
2043 			(*dc->dc_func)(dc->dc_dev);
2044 			config_pending_decr(dc->dc_dev);
2045 			kmem_free(dc, sizeof(*dc));
2046 		}
2047 	}
2048 }
2049 
2050 /*
2051  * Manipulate the config_pending semaphore.
2052  */
2053 void
2054 config_pending_incr(device_t dev)
2055 {
2056 
2057 	mutex_enter(&config_misc_lock);
2058 	config_pending++;
2059 #ifdef DEBUG_AUTOCONF
2060 	printf("%s: %s %d\n", __func__, device_xname(dev), config_pending);
2061 #endif
2062 	mutex_exit(&config_misc_lock);
2063 }
2064 
2065 void
2066 config_pending_decr(device_t dev)
2067 {
2068 
2069 	KASSERT(0 < config_pending);
2070 	mutex_enter(&config_misc_lock);
2071 	config_pending--;
2072 #ifdef DEBUG_AUTOCONF
2073 	printf("%s: %s %d\n", __func__, device_xname(dev), config_pending);
2074 #endif
2075 	if (config_pending == 0)
2076 		cv_broadcast(&config_misc_cv);
2077 	mutex_exit(&config_misc_lock);
2078 }
2079 
2080 /*
2081  * Register a "finalization" routine.  Finalization routines are
2082  * called iteratively once all real devices have been found during
2083  * autoconfiguration, for as long as any one finalizer has done
2084  * any work.
2085  */
2086 int
2087 config_finalize_register(device_t dev, int (*fn)(device_t))
2088 {
2089 	struct finalize_hook *f;
2090 
2091 	/*
2092 	 * If finalization has already been done, invoke the
2093 	 * callback function now.
2094 	 */
2095 	if (config_finalize_done) {
2096 		while ((*fn)(dev) != 0)
2097 			/* loop */ ;
2098 		return 0;
2099 	}
2100 
2101 	/* Ensure this isn't already on the list. */
2102 	TAILQ_FOREACH(f, &config_finalize_list, f_list) {
2103 		if (f->f_func == fn && f->f_dev == dev)
2104 			return EEXIST;
2105 	}
2106 
2107 	f = kmem_alloc(sizeof(*f), KM_SLEEP);
2108 	f->f_func = fn;
2109 	f->f_dev = dev;
2110 	TAILQ_INSERT_TAIL(&config_finalize_list, f, f_list);
2111 
2112 	return 0;
2113 }
2114 
2115 void
2116 config_finalize(void)
2117 {
2118 	struct finalize_hook *f;
2119 	struct pdevinit *pdev;
2120 	extern struct pdevinit pdevinit[];
2121 	int errcnt, rv;
2122 
2123 	/*
2124 	 * Now that device driver threads have been created, wait for
2125 	 * them to finish any deferred autoconfiguration.
2126 	 */
2127 	mutex_enter(&config_misc_lock);
2128 	while (config_pending != 0)
2129 		cv_wait(&config_misc_cv, &config_misc_lock);
2130 	mutex_exit(&config_misc_lock);
2131 
2132 	KERNEL_LOCK(1, NULL);
2133 
2134 	/* Attach pseudo-devices. */
2135 	for (pdev = pdevinit; pdev->pdev_attach != NULL; pdev++)
2136 		(*pdev->pdev_attach)(pdev->pdev_count);
2137 
2138 	/* Run the hooks until none of them does any work. */
2139 	do {
2140 		rv = 0;
2141 		TAILQ_FOREACH(f, &config_finalize_list, f_list)
2142 			rv |= (*f->f_func)(f->f_dev);
2143 	} while (rv != 0);
2144 
2145 	config_finalize_done = 1;
2146 
2147 	/* Now free all the hooks. */
2148 	while ((f = TAILQ_FIRST(&config_finalize_list)) != NULL) {
2149 		TAILQ_REMOVE(&config_finalize_list, f, f_list);
2150 		kmem_free(f, sizeof(*f));
2151 	}
2152 
2153 	KERNEL_UNLOCK_ONE(NULL);
2154 
2155 	errcnt = aprint_get_error_count();
2156 	if ((boothowto & (AB_QUIET|AB_SILENT)) != 0 &&
2157 	    (boothowto & AB_VERBOSE) == 0) {
2158 		mutex_enter(&config_misc_lock);
2159 		if (config_do_twiddle) {
2160 			config_do_twiddle = 0;
2161 			printf_nolog(" done.\n");
2162 		}
2163 		mutex_exit(&config_misc_lock);
2164 	}
2165 	if (errcnt != 0) {
2166 		printf("WARNING: %d error%s while detecting hardware; "
2167 		    "check system log.\n", errcnt,
2168 		    errcnt == 1 ? "" : "s");
2169 	}
2170 }
2171 
2172 void
2173 config_twiddle_init(void)
2174 {
2175 
2176 	if ((boothowto & (AB_SILENT|AB_VERBOSE)) == AB_SILENT) {
2177 		config_do_twiddle = 1;
2178 	}
2179 	callout_setfunc(&config_twiddle_ch, config_twiddle_fn, NULL);
2180 }
2181 
2182 void
2183 config_twiddle_fn(void *cookie)
2184 {
2185 
2186 	mutex_enter(&config_misc_lock);
2187 	if (config_do_twiddle) {
2188 		twiddle();
2189 		callout_schedule(&config_twiddle_ch, mstohz(100));
2190 	}
2191 	mutex_exit(&config_misc_lock);
2192 }
2193 
2194 static void
2195 config_alldevs_enter(struct alldevs_foray *af)
2196 {
2197 	TAILQ_INIT(&af->af_garbage);
2198 	mutex_enter(&alldevs_lock);
2199 	config_collect_garbage(&af->af_garbage);
2200 }
2201 
2202 static void
2203 config_alldevs_exit(struct alldevs_foray *af)
2204 {
2205 	mutex_exit(&alldevs_lock);
2206 	config_dump_garbage(&af->af_garbage);
2207 }
2208 
2209 /*
2210  * device_lookup:
2211  *
2212  *	Look up a device instance for a given driver.
2213  */
2214 device_t
2215 device_lookup(cfdriver_t cd, int unit)
2216 {
2217 	device_t dv;
2218 
2219 	mutex_enter(&alldevs_lock);
2220 	if (unit < 0 || unit >= cd->cd_ndevs)
2221 		dv = NULL;
2222 	else if ((dv = cd->cd_devs[unit]) != NULL && dv->dv_del_gen != 0)
2223 		dv = NULL;
2224 	mutex_exit(&alldevs_lock);
2225 
2226 	return dv;
2227 }
2228 
2229 /*
2230  * device_lookup_private:
2231  *
2232  *	Look up a softc instance for a given driver.
2233  */
2234 void *
2235 device_lookup_private(cfdriver_t cd, int unit)
2236 {
2237 
2238 	return device_private(device_lookup(cd, unit));
2239 }
2240 
2241 /*
2242  * device_find_by_xname:
2243  *
2244  *	Returns the device of the given name or NULL if it doesn't exist.
2245  */
2246 device_t
2247 device_find_by_xname(const char *name)
2248 {
2249 	device_t dv;
2250 	deviter_t di;
2251 
2252 	for (dv = deviter_first(&di, 0); dv != NULL; dv = deviter_next(&di)) {
2253 		if (strcmp(device_xname(dv), name) == 0)
2254 			break;
2255 	}
2256 	deviter_release(&di);
2257 
2258 	return dv;
2259 }
2260 
2261 /*
2262  * device_find_by_driver_unit:
2263  *
2264  *	Returns the device of the given driver name and unit or
2265  *	NULL if it doesn't exist.
2266  */
2267 device_t
2268 device_find_by_driver_unit(const char *name, int unit)
2269 {
2270 	struct cfdriver *cd;
2271 
2272 	if ((cd = config_cfdriver_lookup(name)) == NULL)
2273 		return NULL;
2274 	return device_lookup(cd, unit);
2275 }
2276 
2277 /*
2278  * device_compatible_match:
2279  *
2280  *	Match a driver's "compatible" data against a device's
2281  *	"compatible" strings.  If a match is found, we return
2282  *	a weighted match result, and optionally the matching
2283  *	entry.
2284  */
2285 int
2286 device_compatible_match(const char **device_compats, int ndevice_compats,
2287 			const struct device_compatible_entry *driver_compats,
2288 			const struct device_compatible_entry **matching_entryp)
2289 {
2290 	const struct device_compatible_entry *dce = NULL;
2291 	int i, match_weight;
2292 
2293 	if (ndevice_compats == 0 || device_compats == NULL ||
2294 	    driver_compats == NULL)
2295 		return 0;
2296 
2297 	/*
2298 	 * We take the first match because we start with the most-specific
2299 	 * device compatible string.
2300 	 */
2301 	for (i = 0, match_weight = ndevice_compats - 1;
2302 	     i < ndevice_compats;
2303 	     i++, match_weight--) {
2304 		for (dce = driver_compats; dce->compat != NULL; dce++) {
2305 			if (strcmp(dce->compat, device_compats[i]) == 0) {
2306 				KASSERT(match_weight >= 0);
2307 				if (matching_entryp)
2308 					*matching_entryp = dce;
2309 				return 1 + match_weight;
2310 			}
2311 		}
2312 	}
2313 	return 0;
2314 }
2315 
2316 /*
2317  * Power management related functions.
2318  */
2319 
2320 bool
2321 device_pmf_is_registered(device_t dev)
2322 {
2323 	return (dev->dv_flags & DVF_POWER_HANDLERS) != 0;
2324 }
2325 
2326 bool
2327 device_pmf_driver_suspend(device_t dev, const pmf_qual_t *qual)
2328 {
2329 	if ((dev->dv_flags & DVF_DRIVER_SUSPENDED) != 0)
2330 		return true;
2331 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) == 0)
2332 		return false;
2333 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_DRIVER &&
2334 	    dev->dv_driver_suspend != NULL &&
2335 	    !(*dev->dv_driver_suspend)(dev, qual))
2336 		return false;
2337 
2338 	dev->dv_flags |= DVF_DRIVER_SUSPENDED;
2339 	return true;
2340 }
2341 
2342 bool
2343 device_pmf_driver_resume(device_t dev, const pmf_qual_t *qual)
2344 {
2345 	if ((dev->dv_flags & DVF_DRIVER_SUSPENDED) == 0)
2346 		return true;
2347 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) != 0)
2348 		return false;
2349 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_DRIVER &&
2350 	    dev->dv_driver_resume != NULL &&
2351 	    !(*dev->dv_driver_resume)(dev, qual))
2352 		return false;
2353 
2354 	dev->dv_flags &= ~DVF_DRIVER_SUSPENDED;
2355 	return true;
2356 }
2357 
2358 bool
2359 device_pmf_driver_shutdown(device_t dev, int how)
2360 {
2361 
2362 	if (*dev->dv_driver_shutdown != NULL &&
2363 	    !(*dev->dv_driver_shutdown)(dev, how))
2364 		return false;
2365 	return true;
2366 }
2367 
2368 bool
2369 device_pmf_driver_register(device_t dev,
2370     bool (*suspend)(device_t, const pmf_qual_t *),
2371     bool (*resume)(device_t, const pmf_qual_t *),
2372     bool (*shutdown)(device_t, int))
2373 {
2374 	dev->dv_driver_suspend = suspend;
2375 	dev->dv_driver_resume = resume;
2376 	dev->dv_driver_shutdown = shutdown;
2377 	dev->dv_flags |= DVF_POWER_HANDLERS;
2378 	return true;
2379 }
2380 
2381 static const char *
2382 curlwp_name(void)
2383 {
2384 	if (curlwp->l_name != NULL)
2385 		return curlwp->l_name;
2386 	else
2387 		return curlwp->l_proc->p_comm;
2388 }
2389 
2390 void
2391 device_pmf_driver_deregister(device_t dev)
2392 {
2393 	device_lock_t dvl = device_getlock(dev);
2394 
2395 	dev->dv_driver_suspend = NULL;
2396 	dev->dv_driver_resume = NULL;
2397 
2398 	mutex_enter(&dvl->dvl_mtx);
2399 	dev->dv_flags &= ~DVF_POWER_HANDLERS;
2400 	while (dvl->dvl_nlock > 0 || dvl->dvl_nwait > 0) {
2401 		/* Wake a thread that waits for the lock.  That
2402 		 * thread will fail to acquire the lock, and then
2403 		 * it will wake the next thread that waits for the
2404 		 * lock, or else it will wake us.
2405 		 */
2406 		cv_signal(&dvl->dvl_cv);
2407 		pmflock_debug(dev, __func__, __LINE__);
2408 		cv_wait(&dvl->dvl_cv, &dvl->dvl_mtx);
2409 		pmflock_debug(dev, __func__, __LINE__);
2410 	}
2411 	mutex_exit(&dvl->dvl_mtx);
2412 }
2413 
2414 bool
2415 device_pmf_driver_child_register(device_t dev)
2416 {
2417 	device_t parent = device_parent(dev);
2418 
2419 	if (parent == NULL || parent->dv_driver_child_register == NULL)
2420 		return true;
2421 	return (*parent->dv_driver_child_register)(dev);
2422 }
2423 
2424 void
2425 device_pmf_driver_set_child_register(device_t dev,
2426     bool (*child_register)(device_t))
2427 {
2428 	dev->dv_driver_child_register = child_register;
2429 }
2430 
2431 static void
2432 pmflock_debug(device_t dev, const char *func, int line)
2433 {
2434 	device_lock_t dvl = device_getlock(dev);
2435 
2436 	aprint_debug_dev(dev,
2437 	    "%s.%d, %s dvl_nlock %d dvl_nwait %d dv_flags %x\n", func, line,
2438 	    curlwp_name(), dvl->dvl_nlock, dvl->dvl_nwait, dev->dv_flags);
2439 }
2440 
2441 static bool
2442 device_pmf_lock1(device_t dev)
2443 {
2444 	device_lock_t dvl = device_getlock(dev);
2445 
2446 	while (device_pmf_is_registered(dev) &&
2447 	    dvl->dvl_nlock > 0 && dvl->dvl_holder != curlwp) {
2448 		dvl->dvl_nwait++;
2449 		pmflock_debug(dev, __func__, __LINE__);
2450 		cv_wait(&dvl->dvl_cv, &dvl->dvl_mtx);
2451 		pmflock_debug(dev, __func__, __LINE__);
2452 		dvl->dvl_nwait--;
2453 	}
2454 	if (!device_pmf_is_registered(dev)) {
2455 		pmflock_debug(dev, __func__, __LINE__);
2456 		/* We could not acquire the lock, but some other thread may
2457 		 * wait for it, also.  Wake that thread.
2458 		 */
2459 		cv_signal(&dvl->dvl_cv);
2460 		return false;
2461 	}
2462 	dvl->dvl_nlock++;
2463 	dvl->dvl_holder = curlwp;
2464 	pmflock_debug(dev, __func__, __LINE__);
2465 	return true;
2466 }
2467 
2468 bool
2469 device_pmf_lock(device_t dev)
2470 {
2471 	bool rc;
2472 	device_lock_t dvl = device_getlock(dev);
2473 
2474 	mutex_enter(&dvl->dvl_mtx);
2475 	rc = device_pmf_lock1(dev);
2476 	mutex_exit(&dvl->dvl_mtx);
2477 
2478 	return rc;
2479 }
2480 
2481 void
2482 device_pmf_unlock(device_t dev)
2483 {
2484 	device_lock_t dvl = device_getlock(dev);
2485 
2486 	KASSERT(dvl->dvl_nlock > 0);
2487 	mutex_enter(&dvl->dvl_mtx);
2488 	if (--dvl->dvl_nlock == 0)
2489 		dvl->dvl_holder = NULL;
2490 	cv_signal(&dvl->dvl_cv);
2491 	pmflock_debug(dev, __func__, __LINE__);
2492 	mutex_exit(&dvl->dvl_mtx);
2493 }
2494 
2495 device_lock_t
2496 device_getlock(device_t dev)
2497 {
2498 	return &dev->dv_lock;
2499 }
2500 
2501 void *
2502 device_pmf_bus_private(device_t dev)
2503 {
2504 	return dev->dv_bus_private;
2505 }
2506 
2507 bool
2508 device_pmf_bus_suspend(device_t dev, const pmf_qual_t *qual)
2509 {
2510 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) != 0)
2511 		return true;
2512 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) == 0 ||
2513 	    (dev->dv_flags & DVF_DRIVER_SUSPENDED) == 0)
2514 		return false;
2515 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_BUS &&
2516 	    dev->dv_bus_suspend != NULL &&
2517 	    !(*dev->dv_bus_suspend)(dev, qual))
2518 		return false;
2519 
2520 	dev->dv_flags |= DVF_BUS_SUSPENDED;
2521 	return true;
2522 }
2523 
2524 bool
2525 device_pmf_bus_resume(device_t dev, const pmf_qual_t *qual)
2526 {
2527 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) == 0)
2528 		return true;
2529 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_BUS &&
2530 	    dev->dv_bus_resume != NULL &&
2531 	    !(*dev->dv_bus_resume)(dev, qual))
2532 		return false;
2533 
2534 	dev->dv_flags &= ~DVF_BUS_SUSPENDED;
2535 	return true;
2536 }
2537 
2538 bool
2539 device_pmf_bus_shutdown(device_t dev, int how)
2540 {
2541 
2542 	if (*dev->dv_bus_shutdown != NULL &&
2543 	    !(*dev->dv_bus_shutdown)(dev, how))
2544 		return false;
2545 	return true;
2546 }
2547 
2548 void
2549 device_pmf_bus_register(device_t dev, void *priv,
2550     bool (*suspend)(device_t, const pmf_qual_t *),
2551     bool (*resume)(device_t, const pmf_qual_t *),
2552     bool (*shutdown)(device_t, int), void (*deregister)(device_t))
2553 {
2554 	dev->dv_bus_private = priv;
2555 	dev->dv_bus_resume = resume;
2556 	dev->dv_bus_suspend = suspend;
2557 	dev->dv_bus_shutdown = shutdown;
2558 	dev->dv_bus_deregister = deregister;
2559 }
2560 
2561 void
2562 device_pmf_bus_deregister(device_t dev)
2563 {
2564 	if (dev->dv_bus_deregister == NULL)
2565 		return;
2566 	(*dev->dv_bus_deregister)(dev);
2567 	dev->dv_bus_private = NULL;
2568 	dev->dv_bus_suspend = NULL;
2569 	dev->dv_bus_resume = NULL;
2570 	dev->dv_bus_deregister = NULL;
2571 }
2572 
2573 void *
2574 device_pmf_class_private(device_t dev)
2575 {
2576 	return dev->dv_class_private;
2577 }
2578 
2579 bool
2580 device_pmf_class_suspend(device_t dev, const pmf_qual_t *qual)
2581 {
2582 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) != 0)
2583 		return true;
2584 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_CLASS &&
2585 	    dev->dv_class_suspend != NULL &&
2586 	    !(*dev->dv_class_suspend)(dev, qual))
2587 		return false;
2588 
2589 	dev->dv_flags |= DVF_CLASS_SUSPENDED;
2590 	return true;
2591 }
2592 
2593 bool
2594 device_pmf_class_resume(device_t dev, const pmf_qual_t *qual)
2595 {
2596 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) == 0)
2597 		return true;
2598 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) != 0 ||
2599 	    (dev->dv_flags & DVF_DRIVER_SUSPENDED) != 0)
2600 		return false;
2601 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_CLASS &&
2602 	    dev->dv_class_resume != NULL &&
2603 	    !(*dev->dv_class_resume)(dev, qual))
2604 		return false;
2605 
2606 	dev->dv_flags &= ~DVF_CLASS_SUSPENDED;
2607 	return true;
2608 }
2609 
2610 void
2611 device_pmf_class_register(device_t dev, void *priv,
2612     bool (*suspend)(device_t, const pmf_qual_t *),
2613     bool (*resume)(device_t, const pmf_qual_t *),
2614     void (*deregister)(device_t))
2615 {
2616 	dev->dv_class_private = priv;
2617 	dev->dv_class_suspend = suspend;
2618 	dev->dv_class_resume = resume;
2619 	dev->dv_class_deregister = deregister;
2620 }
2621 
2622 void
2623 device_pmf_class_deregister(device_t dev)
2624 {
2625 	if (dev->dv_class_deregister == NULL)
2626 		return;
2627 	(*dev->dv_class_deregister)(dev);
2628 	dev->dv_class_private = NULL;
2629 	dev->dv_class_suspend = NULL;
2630 	dev->dv_class_resume = NULL;
2631 	dev->dv_class_deregister = NULL;
2632 }
2633 
2634 bool
2635 device_active(device_t dev, devactive_t type)
2636 {
2637 	size_t i;
2638 
2639 	if (dev->dv_activity_count == 0)
2640 		return false;
2641 
2642 	for (i = 0; i < dev->dv_activity_count; ++i) {
2643 		if (dev->dv_activity_handlers[i] == NULL)
2644 			break;
2645 		(*dev->dv_activity_handlers[i])(dev, type);
2646 	}
2647 
2648 	return true;
2649 }
2650 
2651 bool
2652 device_active_register(device_t dev, void (*handler)(device_t, devactive_t))
2653 {
2654 	void (**new_handlers)(device_t, devactive_t);
2655 	void (**old_handlers)(device_t, devactive_t);
2656 	size_t i, old_size, new_size;
2657 	int s;
2658 
2659 	old_handlers = dev->dv_activity_handlers;
2660 	old_size = dev->dv_activity_count;
2661 
2662 	KASSERT(old_size == 0 || old_handlers != NULL);
2663 
2664 	for (i = 0; i < old_size; ++i) {
2665 		KASSERT(old_handlers[i] != handler);
2666 		if (old_handlers[i] == NULL) {
2667 			old_handlers[i] = handler;
2668 			return true;
2669 		}
2670 	}
2671 
2672 	new_size = old_size + 4;
2673 	new_handlers = kmem_alloc(sizeof(void *[new_size]), KM_SLEEP);
2674 
2675 	for (i = 0; i < old_size; ++i)
2676 		new_handlers[i] = old_handlers[i];
2677 	new_handlers[old_size] = handler;
2678 	for (i = old_size+1; i < new_size; ++i)
2679 		new_handlers[i] = NULL;
2680 
2681 	s = splhigh();
2682 	dev->dv_activity_count = new_size;
2683 	dev->dv_activity_handlers = new_handlers;
2684 	splx(s);
2685 
2686 	if (old_size > 0)
2687 		kmem_free(old_handlers, sizeof(void * [old_size]));
2688 
2689 	return true;
2690 }
2691 
2692 void
2693 device_active_deregister(device_t dev, void (*handler)(device_t, devactive_t))
2694 {
2695 	void (**old_handlers)(device_t, devactive_t);
2696 	size_t i, old_size;
2697 	int s;
2698 
2699 	old_handlers = dev->dv_activity_handlers;
2700 	old_size = dev->dv_activity_count;
2701 
2702 	for (i = 0; i < old_size; ++i) {
2703 		if (old_handlers[i] == handler)
2704 			break;
2705 		if (old_handlers[i] == NULL)
2706 			return; /* XXX panic? */
2707 	}
2708 
2709 	if (i == old_size)
2710 		return; /* XXX panic? */
2711 
2712 	for (; i < old_size - 1; ++i) {
2713 		if ((old_handlers[i] = old_handlers[i + 1]) != NULL)
2714 			continue;
2715 
2716 		if (i == 0) {
2717 			s = splhigh();
2718 			dev->dv_activity_count = 0;
2719 			dev->dv_activity_handlers = NULL;
2720 			splx(s);
2721 			kmem_free(old_handlers, sizeof(void *[old_size]));
2722 		}
2723 		return;
2724 	}
2725 	old_handlers[i] = NULL;
2726 }
2727 
2728 /* Return true iff the device_t `dev' exists at generation `gen'. */
2729 static bool
2730 device_exists_at(device_t dv, devgen_t gen)
2731 {
2732 	return (dv->dv_del_gen == 0 || dv->dv_del_gen > gen) &&
2733 	    dv->dv_add_gen <= gen;
2734 }
2735 
2736 static bool
2737 deviter_visits(const deviter_t *di, device_t dv)
2738 {
2739 	return device_exists_at(dv, di->di_gen);
2740 }
2741 
2742 /*
2743  * Device Iteration
2744  *
2745  * deviter_t: a device iterator.  Holds state for a "walk" visiting
2746  *     each device_t's in the device tree.
2747  *
2748  * deviter_init(di, flags): initialize the device iterator `di'
2749  *     to "walk" the device tree.  deviter_next(di) will return
2750  *     the first device_t in the device tree, or NULL if there are
2751  *     no devices.
2752  *
2753  *     `flags' is one or more of DEVITER_F_RW, indicating that the
2754  *     caller intends to modify the device tree by calling
2755  *     config_detach(9) on devices in the order that the iterator
2756  *     returns them; DEVITER_F_ROOT_FIRST, asking for the devices
2757  *     nearest the "root" of the device tree to be returned, first;
2758  *     DEVITER_F_LEAVES_FIRST, asking for the devices furthest from
2759  *     the root of the device tree, first; and DEVITER_F_SHUTDOWN,
2760  *     indicating both that deviter_init() should not respect any
2761  *     locks on the device tree, and that deviter_next(di) may run
2762  *     in more than one LWP before the walk has finished.
2763  *
2764  *     Only one DEVITER_F_RW iterator may be in the device tree at
2765  *     once.
2766  *
2767  *     DEVITER_F_SHUTDOWN implies DEVITER_F_RW.
2768  *
2769  *     Results are undefined if the flags DEVITER_F_ROOT_FIRST and
2770  *     DEVITER_F_LEAVES_FIRST are used in combination.
2771  *
2772  * deviter_first(di, flags): initialize the device iterator `di'
2773  *     and return the first device_t in the device tree, or NULL
2774  *     if there are no devices.  The statement
2775  *
2776  *         dv = deviter_first(di);
2777  *
2778  *     is shorthand for
2779  *
2780  *         deviter_init(di);
2781  *         dv = deviter_next(di);
2782  *
2783  * deviter_next(di): return the next device_t in the device tree,
2784  *     or NULL if there are no more devices.  deviter_next(di)
2785  *     is undefined if `di' was not initialized with deviter_init() or
2786  *     deviter_first().
2787  *
2788  * deviter_release(di): stops iteration (subsequent calls to
2789  *     deviter_next() will return NULL), releases any locks and
2790  *     resources held by the device iterator.
2791  *
2792  * Device iteration does not return device_t's in any particular
2793  * order.  An iterator will never return the same device_t twice.
2794  * Device iteration is guaranteed to complete---i.e., if deviter_next(di)
2795  * is called repeatedly on the same `di', it will eventually return
2796  * NULL.  It is ok to attach/detach devices during device iteration.
2797  */
2798 void
2799 deviter_init(deviter_t *di, deviter_flags_t flags)
2800 {
2801 	device_t dv;
2802 
2803 	memset(di, 0, sizeof(*di));
2804 
2805 	if ((flags & DEVITER_F_SHUTDOWN) != 0)
2806 		flags |= DEVITER_F_RW;
2807 
2808 	mutex_enter(&alldevs_lock);
2809 	if ((flags & DEVITER_F_RW) != 0)
2810 		alldevs_nwrite++;
2811 	else
2812 		alldevs_nread++;
2813 	di->di_gen = alldevs_gen++;
2814 	di->di_flags = flags;
2815 
2816 	switch (di->di_flags & (DEVITER_F_LEAVES_FIRST|DEVITER_F_ROOT_FIRST)) {
2817 	case DEVITER_F_LEAVES_FIRST:
2818 		TAILQ_FOREACH(dv, &alldevs, dv_list) {
2819 			if (!deviter_visits(di, dv))
2820 				continue;
2821 			di->di_curdepth = MAX(di->di_curdepth, dv->dv_depth);
2822 		}
2823 		break;
2824 	case DEVITER_F_ROOT_FIRST:
2825 		TAILQ_FOREACH(dv, &alldevs, dv_list) {
2826 			if (!deviter_visits(di, dv))
2827 				continue;
2828 			di->di_maxdepth = MAX(di->di_maxdepth, dv->dv_depth);
2829 		}
2830 		break;
2831 	default:
2832 		break;
2833 	}
2834 
2835 	deviter_reinit(di);
2836 	mutex_exit(&alldevs_lock);
2837 }
2838 
2839 static void
2840 deviter_reinit(deviter_t *di)
2841 {
2842 
2843 	KASSERT(mutex_owned(&alldevs_lock));
2844 	if ((di->di_flags & DEVITER_F_RW) != 0)
2845 		di->di_prev = TAILQ_LAST(&alldevs, devicelist);
2846 	else
2847 		di->di_prev = TAILQ_FIRST(&alldevs);
2848 }
2849 
2850 device_t
2851 deviter_first(deviter_t *di, deviter_flags_t flags)
2852 {
2853 
2854 	deviter_init(di, flags);
2855 	return deviter_next(di);
2856 }
2857 
2858 static device_t
2859 deviter_next2(deviter_t *di)
2860 {
2861 	device_t dv;
2862 
2863 	KASSERT(mutex_owned(&alldevs_lock));
2864 
2865 	dv = di->di_prev;
2866 
2867 	if (dv == NULL)
2868 		return NULL;
2869 
2870 	if ((di->di_flags & DEVITER_F_RW) != 0)
2871 		di->di_prev = TAILQ_PREV(dv, devicelist, dv_list);
2872 	else
2873 		di->di_prev = TAILQ_NEXT(dv, dv_list);
2874 
2875 	return dv;
2876 }
2877 
2878 static device_t
2879 deviter_next1(deviter_t *di)
2880 {
2881 	device_t dv;
2882 
2883 	KASSERT(mutex_owned(&alldevs_lock));
2884 
2885 	do {
2886 		dv = deviter_next2(di);
2887 	} while (dv != NULL && !deviter_visits(di, dv));
2888 
2889 	return dv;
2890 }
2891 
2892 device_t
2893 deviter_next(deviter_t *di)
2894 {
2895 	device_t dv = NULL;
2896 
2897 	mutex_enter(&alldevs_lock);
2898 	switch (di->di_flags & (DEVITER_F_LEAVES_FIRST|DEVITER_F_ROOT_FIRST)) {
2899 	case 0:
2900 		dv = deviter_next1(di);
2901 		break;
2902 	case DEVITER_F_LEAVES_FIRST:
2903 		while (di->di_curdepth >= 0) {
2904 			if ((dv = deviter_next1(di)) == NULL) {
2905 				di->di_curdepth--;
2906 				deviter_reinit(di);
2907 			} else if (dv->dv_depth == di->di_curdepth)
2908 				break;
2909 		}
2910 		break;
2911 	case DEVITER_F_ROOT_FIRST:
2912 		while (di->di_curdepth <= di->di_maxdepth) {
2913 			if ((dv = deviter_next1(di)) == NULL) {
2914 				di->di_curdepth++;
2915 				deviter_reinit(di);
2916 			} else if (dv->dv_depth == di->di_curdepth)
2917 				break;
2918 		}
2919 		break;
2920 	default:
2921 		break;
2922 	}
2923 	mutex_exit(&alldevs_lock);
2924 
2925 	return dv;
2926 }
2927 
2928 void
2929 deviter_release(deviter_t *di)
2930 {
2931 	bool rw = (di->di_flags & DEVITER_F_RW) != 0;
2932 
2933 	mutex_enter(&alldevs_lock);
2934 	if (rw)
2935 		--alldevs_nwrite;
2936 	else
2937 		--alldevs_nread;
2938 	/* XXX wake a garbage-collection thread */
2939 	mutex_exit(&alldevs_lock);
2940 }
2941 
2942 const char *
2943 cfdata_ifattr(const struct cfdata *cf)
2944 {
2945 	return cf->cf_pspec->cfp_iattr;
2946 }
2947 
2948 bool
2949 ifattr_match(const char *snull, const char *t)
2950 {
2951 	return (snull == NULL) || strcmp(snull, t) == 0;
2952 }
2953 
2954 void
2955 null_childdetached(device_t self, device_t child)
2956 {
2957 	/* do nothing */
2958 }
2959 
2960 static void
2961 sysctl_detach_setup(struct sysctllog **clog)
2962 {
2963 
2964 	sysctl_createv(clog, 0, NULL, NULL,
2965 		CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
2966 		CTLTYPE_BOOL, "detachall",
2967 		SYSCTL_DESCR("Detach all devices at shutdown"),
2968 		NULL, 0, &detachall, 0,
2969 		CTL_KERN, CTL_CREATE, CTL_EOL);
2970 }
2971