xref: /netbsd-src/sys/kern/subr_autoconf.c (revision c29d51755812ace2e87aeefdb06cb2b4dac7087a)
1 /* $NetBSD: subr_autoconf.c,v 1.235 2015/04/13 16:46:33 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 1.235 2015/04/13 16:46:33 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/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_unlock(int);
176 static int config_alldevs_lock(void);
177 static void config_alldevs_enter(struct alldevs_foray *);
178 static void config_alldevs_exit(struct alldevs_foray *);
179 static void config_add_attrib_dict(device_t);
180 
181 static void config_collect_garbage(struct devicelist *);
182 static void config_dump_garbage(struct devicelist *);
183 
184 static void pmflock_debug(device_t, const char *, int);
185 
186 static device_t deviter_next1(deviter_t *);
187 static void deviter_reinit(deviter_t *);
188 
189 struct deferred_config {
190 	TAILQ_ENTRY(deferred_config) dc_queue;
191 	device_t dc_dev;
192 	void (*dc_func)(device_t);
193 };
194 
195 TAILQ_HEAD(deferred_config_head, deferred_config);
196 
197 struct deferred_config_head deferred_config_queue =
198 	TAILQ_HEAD_INITIALIZER(deferred_config_queue);
199 struct deferred_config_head interrupt_config_queue =
200 	TAILQ_HEAD_INITIALIZER(interrupt_config_queue);
201 int interrupt_config_threads = 8;
202 struct deferred_config_head mountroot_config_queue =
203 	TAILQ_HEAD_INITIALIZER(mountroot_config_queue);
204 int mountroot_config_threads = 2;
205 static lwp_t **mountroot_config_lwpids;
206 static size_t mountroot_config_lwpids_size;
207 static bool root_is_mounted = false;
208 
209 static void config_process_deferred(struct deferred_config_head *, device_t);
210 
211 /* Hooks to finalize configuration once all real devices have been found. */
212 struct finalize_hook {
213 	TAILQ_ENTRY(finalize_hook) f_list;
214 	int (*f_func)(device_t);
215 	device_t f_dev;
216 };
217 static TAILQ_HEAD(, finalize_hook) config_finalize_list =
218 	TAILQ_HEAD_INITIALIZER(config_finalize_list);
219 static int config_finalize_done;
220 
221 /* list of all devices */
222 static struct devicelist alldevs = TAILQ_HEAD_INITIALIZER(alldevs);
223 static kmutex_t alldevs_mtx;
224 static volatile bool alldevs_garbage = false;
225 static volatile devgen_t alldevs_gen = 1;
226 static volatile int alldevs_nread = 0;
227 static volatile int alldevs_nwrite = 0;
228 
229 static int config_pending;		/* semaphore for mountroot */
230 static kmutex_t config_misc_lock;
231 static kcondvar_t config_misc_cv;
232 
233 static bool detachall = false;
234 
235 #define	STREQ(s1, s2)			\
236 	(*(s1) == *(s2) && strcmp((s1), (s2)) == 0)
237 
238 static bool config_initialized = false;	/* config_init() has been called. */
239 
240 static int config_do_twiddle;
241 static callout_t config_twiddle_ch;
242 
243 static void sysctl_detach_setup(struct sysctllog **);
244 
245 typedef int (*cfdriver_fn)(struct cfdriver *);
246 static int
247 frob_cfdrivervec(struct cfdriver * const *cfdriverv,
248 	cfdriver_fn drv_do, cfdriver_fn drv_undo,
249 	const char *style, bool dopanic)
250 {
251 	void (*pr)(const char *, ...) __printflike(1, 2) =
252 	    dopanic ? panic : printf;
253 	int i, error = 0, e2 __diagused;
254 
255 	for (i = 0; cfdriverv[i] != NULL; i++) {
256 		if ((error = drv_do(cfdriverv[i])) != 0) {
257 			pr("configure: `%s' driver %s failed: %d",
258 			    cfdriverv[i]->cd_name, style, error);
259 			goto bad;
260 		}
261 	}
262 
263 	KASSERT(error == 0);
264 	return 0;
265 
266  bad:
267 	printf("\n");
268 	for (i--; i >= 0; i--) {
269 		e2 = drv_undo(cfdriverv[i]);
270 		KASSERT(e2 == 0);
271 	}
272 
273 	return error;
274 }
275 
276 typedef int (*cfattach_fn)(const char *, struct cfattach *);
277 static int
278 frob_cfattachvec(const struct cfattachinit *cfattachv,
279 	cfattach_fn att_do, cfattach_fn att_undo,
280 	const char *style, bool dopanic)
281 {
282 	const struct cfattachinit *cfai = NULL;
283 	void (*pr)(const char *, ...) __printflike(1, 2) =
284 	    dopanic ? panic : printf;
285 	int j = 0, error = 0, e2 __diagused;
286 
287 	for (cfai = &cfattachv[0]; cfai->cfai_name != NULL; cfai++) {
288 		for (j = 0; cfai->cfai_list[j] != NULL; j++) {
289 			if ((error = att_do(cfai->cfai_name,
290 			    cfai->cfai_list[j])) != 0) {
291 				pr("configure: attachment `%s' "
292 				    "of `%s' driver %s failed: %d",
293 				    cfai->cfai_list[j]->ca_name,
294 				    cfai->cfai_name, style, error);
295 				goto bad;
296 			}
297 		}
298 	}
299 
300 	KASSERT(error == 0);
301 	return 0;
302 
303  bad:
304 	/*
305 	 * Rollback in reverse order.  dunno if super-important, but
306 	 * do that anyway.  Although the code looks a little like
307 	 * someone did a little integration (in the math sense).
308 	 */
309 	printf("\n");
310 	if (cfai) {
311 		bool last;
312 
313 		for (last = false; last == false; ) {
314 			if (cfai == &cfattachv[0])
315 				last = true;
316 			for (j--; j >= 0; j--) {
317 				e2 = att_undo(cfai->cfai_name,
318 				    cfai->cfai_list[j]);
319 				KASSERT(e2 == 0);
320 			}
321 			if (!last) {
322 				cfai--;
323 				for (j = 0; cfai->cfai_list[j] != NULL; j++)
324 					;
325 			}
326 		}
327 	}
328 
329 	return error;
330 }
331 
332 /*
333  * Initialize the autoconfiguration data structures.  Normally this
334  * is done by configure(), but some platforms need to do this very
335  * early (to e.g. initialize the console).
336  */
337 void
338 config_init(void)
339 {
340 
341 	KASSERT(config_initialized == false);
342 
343 	mutex_init(&alldevs_mtx, MUTEX_DEFAULT, IPL_VM);
344 
345 	mutex_init(&config_misc_lock, MUTEX_DEFAULT, IPL_NONE);
346 	cv_init(&config_misc_cv, "cfgmisc");
347 
348 	callout_init(&config_twiddle_ch, CALLOUT_MPSAFE);
349 
350 	frob_cfdrivervec(cfdriver_list_initial,
351 	    config_cfdriver_attach, NULL, "bootstrap", true);
352 	frob_cfattachvec(cfattachinit,
353 	    config_cfattach_attach, NULL, "bootstrap", true);
354 
355 	initcftable.ct_cfdata = cfdata;
356 	TAILQ_INSERT_TAIL(&allcftables, &initcftable, ct_list);
357 
358 	config_initialized = true;
359 }
360 
361 /*
362  * Init or fini drivers and attachments.  Either all or none
363  * are processed (via rollback).  It would be nice if this were
364  * atomic to outside consumers, but with the current state of
365  * locking ...
366  */
367 int
368 config_init_component(struct cfdriver * const *cfdriverv,
369 	const struct cfattachinit *cfattachv, struct cfdata *cfdatav)
370 {
371 	int error;
372 
373 	if ((error = frob_cfdrivervec(cfdriverv,
374 	    config_cfdriver_attach, config_cfdriver_detach, "init", false))!= 0)
375 		return error;
376 	if ((error = frob_cfattachvec(cfattachv,
377 	    config_cfattach_attach, config_cfattach_detach,
378 	    "init", false)) != 0) {
379 		frob_cfdrivervec(cfdriverv,
380 	            config_cfdriver_detach, NULL, "init rollback", true);
381 		return error;
382 	}
383 	if ((error = config_cfdata_attach(cfdatav, 1)) != 0) {
384 		frob_cfattachvec(cfattachv,
385 		    config_cfattach_detach, NULL, "init rollback", true);
386 		frob_cfdrivervec(cfdriverv,
387 	            config_cfdriver_detach, NULL, "init rollback", true);
388 		return error;
389 	}
390 
391 	return 0;
392 }
393 
394 int
395 config_fini_component(struct cfdriver * const *cfdriverv,
396 	const struct cfattachinit *cfattachv, struct cfdata *cfdatav)
397 {
398 	int error;
399 
400 	if ((error = config_cfdata_detach(cfdatav)) != 0)
401 		return error;
402 	if ((error = frob_cfattachvec(cfattachv,
403 	    config_cfattach_detach, config_cfattach_attach,
404 	    "fini", false)) != 0) {
405 		if (config_cfdata_attach(cfdatav, 0) != 0)
406 			panic("config_cfdata fini rollback failed");
407 		return error;
408 	}
409 	if ((error = frob_cfdrivervec(cfdriverv,
410 	    config_cfdriver_detach, config_cfdriver_attach,
411 	    "fini", false)) != 0) {
412 		frob_cfattachvec(cfattachv,
413 	            config_cfattach_attach, NULL, "fini rollback", true);
414 		if (config_cfdata_attach(cfdatav, 0) != 0)
415 			panic("config_cfdata fini rollback failed");
416 		return error;
417 	}
418 
419 	return 0;
420 }
421 
422 void
423 config_init_mi(void)
424 {
425 
426 	if (!config_initialized)
427 		config_init();
428 
429 	sysctl_detach_setup(NULL);
430 }
431 
432 void
433 config_deferred(device_t dev)
434 {
435 	config_process_deferred(&deferred_config_queue, dev);
436 	config_process_deferred(&interrupt_config_queue, dev);
437 	config_process_deferred(&mountroot_config_queue, dev);
438 }
439 
440 static void
441 config_interrupts_thread(void *cookie)
442 {
443 	struct deferred_config *dc;
444 
445 	while ((dc = TAILQ_FIRST(&interrupt_config_queue)) != NULL) {
446 		TAILQ_REMOVE(&interrupt_config_queue, dc, dc_queue);
447 		(*dc->dc_func)(dc->dc_dev);
448 		config_pending_decr(dc->dc_dev);
449 		kmem_free(dc, sizeof(*dc));
450 	}
451 	kthread_exit(0);
452 }
453 
454 void
455 config_create_interruptthreads(void)
456 {
457 	int i;
458 
459 	for (i = 0; i < interrupt_config_threads; i++) {
460 		(void)kthread_create(PRI_NONE, 0, NULL,
461 		    config_interrupts_thread, NULL, NULL, "configintr");
462 	}
463 }
464 
465 static void
466 config_mountroot_thread(void *cookie)
467 {
468 	struct deferred_config *dc;
469 
470 	while ((dc = TAILQ_FIRST(&mountroot_config_queue)) != NULL) {
471 		TAILQ_REMOVE(&mountroot_config_queue, dc, dc_queue);
472 		(*dc->dc_func)(dc->dc_dev);
473 		kmem_free(dc, sizeof(*dc));
474 	}
475 	kthread_exit(0);
476 }
477 
478 void
479 config_create_mountrootthreads(void)
480 {
481 	int i;
482 
483 	if (!root_is_mounted)
484 		root_is_mounted = true;
485 
486 	mountroot_config_lwpids_size = sizeof(mountroot_config_lwpids) *
487 				       mountroot_config_threads;
488 	mountroot_config_lwpids = kmem_alloc(mountroot_config_lwpids_size,
489 					     KM_NOSLEEP);
490 	KASSERT(mountroot_config_lwpids);
491 	for (i = 0; i < mountroot_config_threads; i++) {
492 		mountroot_config_lwpids[i] = 0;
493 		(void)kthread_create(PRI_NONE, KTHREAD_MUSTJOIN, NULL,
494 				     config_mountroot_thread, NULL,
495 				     &mountroot_config_lwpids[i],
496 				     "configroot");
497 	}
498 }
499 
500 void
501 config_finalize_mountroot(void)
502 {
503 	int i, error;
504 
505 	for (i = 0; i < mountroot_config_threads; i++) {
506 		if (mountroot_config_lwpids[i] == 0)
507 			continue;
508 
509 		error = kthread_join(mountroot_config_lwpids[i]);
510 		if (error)
511 			printf("%s: thread %x joined with error %d\n",
512 			       __func__, i, error);
513 	}
514 	kmem_free(mountroot_config_lwpids, mountroot_config_lwpids_size);
515 }
516 
517 /*
518  * Announce device attach/detach to userland listeners.
519  */
520 static void
521 devmon_report_device(device_t dev, bool isattach)
522 {
523 #if NDRVCTL > 0
524 	prop_dictionary_t ev;
525 	const char *parent;
526 	const char *what;
527 	device_t pdev = device_parent(dev);
528 
529 	ev = prop_dictionary_create();
530 	if (ev == NULL)
531 		return;
532 
533 	what = (isattach ? "device-attach" : "device-detach");
534 	parent = (pdev == NULL ? "root" : device_xname(pdev));
535 	if (!prop_dictionary_set_cstring(ev, "device", device_xname(dev)) ||
536 	    !prop_dictionary_set_cstring(ev, "parent", parent)) {
537 		prop_object_release(ev);
538 		return;
539 	}
540 
541 	devmon_insert(what, ev);
542 #endif
543 }
544 
545 /*
546  * Add a cfdriver to the system.
547  */
548 int
549 config_cfdriver_attach(struct cfdriver *cd)
550 {
551 	struct cfdriver *lcd;
552 
553 	/* Make sure this driver isn't already in the system. */
554 	LIST_FOREACH(lcd, &allcfdrivers, cd_list) {
555 		if (STREQ(lcd->cd_name, cd->cd_name))
556 			return EEXIST;
557 	}
558 
559 	LIST_INIT(&cd->cd_attach);
560 	LIST_INSERT_HEAD(&allcfdrivers, cd, cd_list);
561 
562 	return 0;
563 }
564 
565 /*
566  * Remove a cfdriver from the system.
567  */
568 int
569 config_cfdriver_detach(struct cfdriver *cd)
570 {
571 	struct alldevs_foray af;
572 	int i, rc = 0;
573 
574 	config_alldevs_enter(&af);
575 	/* Make sure there are no active instances. */
576 	for (i = 0; i < cd->cd_ndevs; i++) {
577 		if (cd->cd_devs[i] != NULL) {
578 			rc = EBUSY;
579 			break;
580 		}
581 	}
582 	config_alldevs_exit(&af);
583 
584 	if (rc != 0)
585 		return rc;
586 
587 	/* ...and no attachments loaded. */
588 	if (LIST_EMPTY(&cd->cd_attach) == 0)
589 		return EBUSY;
590 
591 	LIST_REMOVE(cd, cd_list);
592 
593 	KASSERT(cd->cd_devs == NULL);
594 
595 	return 0;
596 }
597 
598 /*
599  * Look up a cfdriver by name.
600  */
601 struct cfdriver *
602 config_cfdriver_lookup(const char *name)
603 {
604 	struct cfdriver *cd;
605 
606 	LIST_FOREACH(cd, &allcfdrivers, cd_list) {
607 		if (STREQ(cd->cd_name, name))
608 			return cd;
609 	}
610 
611 	return NULL;
612 }
613 
614 /*
615  * Add a cfattach to the specified driver.
616  */
617 int
618 config_cfattach_attach(const char *driver, struct cfattach *ca)
619 {
620 	struct cfattach *lca;
621 	struct cfdriver *cd;
622 
623 	cd = config_cfdriver_lookup(driver);
624 	if (cd == NULL)
625 		return ESRCH;
626 
627 	/* Make sure this attachment isn't already on this driver. */
628 	LIST_FOREACH(lca, &cd->cd_attach, ca_list) {
629 		if (STREQ(lca->ca_name, ca->ca_name))
630 			return EEXIST;
631 	}
632 
633 	LIST_INSERT_HEAD(&cd->cd_attach, ca, ca_list);
634 
635 	return 0;
636 }
637 
638 /*
639  * Remove a cfattach from the specified driver.
640  */
641 int
642 config_cfattach_detach(const char *driver, struct cfattach *ca)
643 {
644 	struct alldevs_foray af;
645 	struct cfdriver *cd;
646 	device_t dev;
647 	int i, rc = 0;
648 
649 	cd = config_cfdriver_lookup(driver);
650 	if (cd == NULL)
651 		return ESRCH;
652 
653 	config_alldevs_enter(&af);
654 	/* Make sure there are no active instances. */
655 	for (i = 0; i < cd->cd_ndevs; i++) {
656 		if ((dev = cd->cd_devs[i]) == NULL)
657 			continue;
658 		if (dev->dv_cfattach == ca) {
659 			rc = EBUSY;
660 			break;
661 		}
662 	}
663 	config_alldevs_exit(&af);
664 
665 	if (rc != 0)
666 		return rc;
667 
668 	LIST_REMOVE(ca, ca_list);
669 
670 	return 0;
671 }
672 
673 /*
674  * Look up a cfattach by name.
675  */
676 static struct cfattach *
677 config_cfattach_lookup_cd(struct cfdriver *cd, const char *atname)
678 {
679 	struct cfattach *ca;
680 
681 	LIST_FOREACH(ca, &cd->cd_attach, ca_list) {
682 		if (STREQ(ca->ca_name, atname))
683 			return ca;
684 	}
685 
686 	return NULL;
687 }
688 
689 /*
690  * Look up a cfattach by driver/attachment name.
691  */
692 struct cfattach *
693 config_cfattach_lookup(const char *name, const char *atname)
694 {
695 	struct cfdriver *cd;
696 
697 	cd = config_cfdriver_lookup(name);
698 	if (cd == NULL)
699 		return NULL;
700 
701 	return config_cfattach_lookup_cd(cd, atname);
702 }
703 
704 /*
705  * Apply the matching function and choose the best.  This is used
706  * a few times and we want to keep the code small.
707  */
708 static void
709 mapply(struct matchinfo *m, cfdata_t cf)
710 {
711 	int pri;
712 
713 	if (m->fn != NULL) {
714 		pri = (*m->fn)(m->parent, cf, m->locs, m->aux);
715 	} else {
716 		pri = config_match(m->parent, cf, m->aux);
717 	}
718 	if (pri > m->pri) {
719 		m->match = cf;
720 		m->pri = pri;
721 	}
722 }
723 
724 int
725 config_stdsubmatch(device_t parent, cfdata_t cf, const int *locs, void *aux)
726 {
727 	const struct cfiattrdata *ci;
728 	const struct cflocdesc *cl;
729 	int nlocs, i;
730 
731 	ci = cfiattr_lookup(cfdata_ifattr(cf), parent->dv_cfdriver);
732 	KASSERT(ci);
733 	nlocs = ci->ci_loclen;
734 	KASSERT(!nlocs || locs);
735 	for (i = 0; i < nlocs; i++) {
736 		cl = &ci->ci_locdesc[i];
737 		if (cl->cld_defaultstr != NULL &&
738 		    cf->cf_loc[i] == cl->cld_default)
739 			continue;
740 		if (cf->cf_loc[i] == locs[i])
741 			continue;
742 		return 0;
743 	}
744 
745 	return config_match(parent, cf, aux);
746 }
747 
748 /*
749  * Helper function: check whether the driver supports the interface attribute
750  * and return its descriptor structure.
751  */
752 static const struct cfiattrdata *
753 cfdriver_get_iattr(const struct cfdriver *cd, const char *ia)
754 {
755 	const struct cfiattrdata * const *cpp;
756 
757 	if (cd->cd_attrs == NULL)
758 		return 0;
759 
760 	for (cpp = cd->cd_attrs; *cpp; cpp++) {
761 		if (STREQ((*cpp)->ci_name, ia)) {
762 			/* Match. */
763 			return *cpp;
764 		}
765 	}
766 	return 0;
767 }
768 
769 /*
770  * Lookup an interface attribute description by name.
771  * If the driver is given, consider only its supported attributes.
772  */
773 const struct cfiattrdata *
774 cfiattr_lookup(const char *name, const struct cfdriver *cd)
775 {
776 	const struct cfdriver *d;
777 	const struct cfiattrdata *ia;
778 
779 	if (cd)
780 		return cfdriver_get_iattr(cd, name);
781 
782 	LIST_FOREACH(d, &allcfdrivers, cd_list) {
783 		ia = cfdriver_get_iattr(d, name);
784 		if (ia)
785 			return ia;
786 	}
787 	return 0;
788 }
789 
790 /*
791  * Determine if `parent' is a potential parent for a device spec based
792  * on `cfp'.
793  */
794 static int
795 cfparent_match(const device_t parent, const struct cfparent *cfp)
796 {
797 	struct cfdriver *pcd;
798 
799 	/* We don't match root nodes here. */
800 	if (cfp == NULL)
801 		return 0;
802 
803 	pcd = parent->dv_cfdriver;
804 	KASSERT(pcd != NULL);
805 
806 	/*
807 	 * First, ensure this parent has the correct interface
808 	 * attribute.
809 	 */
810 	if (!cfdriver_get_iattr(pcd, cfp->cfp_iattr))
811 		return 0;
812 
813 	/*
814 	 * If no specific parent device instance was specified (i.e.
815 	 * we're attaching to the attribute only), we're done!
816 	 */
817 	if (cfp->cfp_parent == NULL)
818 		return 1;
819 
820 	/*
821 	 * Check the parent device's name.
822 	 */
823 	if (STREQ(pcd->cd_name, cfp->cfp_parent) == 0)
824 		return 0;	/* not the same parent */
825 
826 	/*
827 	 * Make sure the unit number matches.
828 	 */
829 	if (cfp->cfp_unit == DVUNIT_ANY ||	/* wildcard */
830 	    cfp->cfp_unit == parent->dv_unit)
831 		return 1;
832 
833 	/* Unit numbers don't match. */
834 	return 0;
835 }
836 
837 /*
838  * Helper for config_cfdata_attach(): check all devices whether it could be
839  * parent any attachment in the config data table passed, and rescan.
840  */
841 static void
842 rescan_with_cfdata(const struct cfdata *cf)
843 {
844 	device_t d;
845 	const struct cfdata *cf1;
846 	deviter_t di;
847 
848 
849 	/*
850 	 * "alldevs" is likely longer than a modules's cfdata, so make it
851 	 * the outer loop.
852 	 */
853 	for (d = deviter_first(&di, 0); d != NULL; d = deviter_next(&di)) {
854 
855 		if (!(d->dv_cfattach->ca_rescan))
856 			continue;
857 
858 		for (cf1 = cf; cf1->cf_name; cf1++) {
859 
860 			if (!cfparent_match(d, cf1->cf_pspec))
861 				continue;
862 
863 			(*d->dv_cfattach->ca_rescan)(d,
864 				cfdata_ifattr(cf1), cf1->cf_loc);
865 
866 			config_deferred(d);
867 		}
868 	}
869 	deviter_release(&di);
870 }
871 
872 /*
873  * Attach a supplemental config data table and rescan potential
874  * parent devices if required.
875  */
876 int
877 config_cfdata_attach(cfdata_t cf, int scannow)
878 {
879 	struct cftable *ct;
880 
881 	ct = kmem_alloc(sizeof(*ct), KM_SLEEP);
882 	ct->ct_cfdata = cf;
883 	TAILQ_INSERT_TAIL(&allcftables, ct, ct_list);
884 
885 	if (scannow)
886 		rescan_with_cfdata(cf);
887 
888 	return 0;
889 }
890 
891 /*
892  * Helper for config_cfdata_detach: check whether a device is
893  * found through any attachment in the config data table.
894  */
895 static int
896 dev_in_cfdata(device_t d, cfdata_t cf)
897 {
898 	const struct cfdata *cf1;
899 
900 	for (cf1 = cf; cf1->cf_name; cf1++)
901 		if (d->dv_cfdata == cf1)
902 			return 1;
903 
904 	return 0;
905 }
906 
907 /*
908  * Detach a supplemental config data table. Detach all devices found
909  * through that table (and thus keeping references to it) before.
910  */
911 int
912 config_cfdata_detach(cfdata_t cf)
913 {
914 	device_t d;
915 	int error = 0;
916 	struct cftable *ct;
917 	deviter_t di;
918 
919 	for (d = deviter_first(&di, DEVITER_F_RW); d != NULL;
920 	     d = deviter_next(&di)) {
921 		if (!dev_in_cfdata(d, cf))
922 			continue;
923 		if ((error = config_detach(d, 0)) != 0)
924 			break;
925 	}
926 	deviter_release(&di);
927 	if (error) {
928 		aprint_error_dev(d, "unable to detach instance\n");
929 		return error;
930 	}
931 
932 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
933 		if (ct->ct_cfdata == cf) {
934 			TAILQ_REMOVE(&allcftables, ct, ct_list);
935 			kmem_free(ct, sizeof(*ct));
936 			return 0;
937 		}
938 	}
939 
940 	/* not found -- shouldn't happen */
941 	return EINVAL;
942 }
943 
944 /*
945  * Invoke the "match" routine for a cfdata entry on behalf of
946  * an external caller, usually a "submatch" routine.
947  */
948 int
949 config_match(device_t parent, cfdata_t cf, void *aux)
950 {
951 	struct cfattach *ca;
952 
953 	ca = config_cfattach_lookup(cf->cf_name, cf->cf_atname);
954 	if (ca == NULL) {
955 		/* No attachment for this entry, oh well. */
956 		return 0;
957 	}
958 
959 	return (*ca->ca_match)(parent, cf, aux);
960 }
961 
962 /*
963  * Iterate over all potential children of some device, calling the given
964  * function (default being the child's match function) for each one.
965  * Nonzero returns are matches; the highest value returned is considered
966  * the best match.  Return the `found child' if we got a match, or NULL
967  * otherwise.  The `aux' pointer is simply passed on through.
968  *
969  * Note that this function is designed so that it can be used to apply
970  * an arbitrary function to all potential children (its return value
971  * can be ignored).
972  */
973 cfdata_t
974 config_search_loc(cfsubmatch_t fn, device_t parent,
975 		  const char *ifattr, const int *locs, void *aux)
976 {
977 	struct cftable *ct;
978 	cfdata_t cf;
979 	struct matchinfo m;
980 
981 	KASSERT(config_initialized);
982 	KASSERT(!ifattr || cfdriver_get_iattr(parent->dv_cfdriver, ifattr));
983 
984 	m.fn = fn;
985 	m.parent = parent;
986 	m.locs = locs;
987 	m.aux = aux;
988 	m.match = NULL;
989 	m.pri = 0;
990 
991 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
992 		for (cf = ct->ct_cfdata; cf->cf_name; cf++) {
993 
994 			/* We don't match root nodes here. */
995 			if (!cf->cf_pspec)
996 				continue;
997 
998 			/*
999 			 * Skip cf if no longer eligible, otherwise scan
1000 			 * through parents for one matching `parent', and
1001 			 * try match function.
1002 			 */
1003 			if (cf->cf_fstate == FSTATE_FOUND)
1004 				continue;
1005 			if (cf->cf_fstate == FSTATE_DNOTFOUND ||
1006 			    cf->cf_fstate == FSTATE_DSTAR)
1007 				continue;
1008 
1009 			/*
1010 			 * If an interface attribute was specified,
1011 			 * consider only children which attach to
1012 			 * that attribute.
1013 			 */
1014 			if (ifattr && !STREQ(ifattr, cfdata_ifattr(cf)))
1015 				continue;
1016 
1017 			if (cfparent_match(parent, cf->cf_pspec))
1018 				mapply(&m, cf);
1019 		}
1020 	}
1021 	return m.match;
1022 }
1023 
1024 cfdata_t
1025 config_search_ia(cfsubmatch_t fn, device_t parent, const char *ifattr,
1026     void *aux)
1027 {
1028 
1029 	return config_search_loc(fn, parent, ifattr, NULL, aux);
1030 }
1031 
1032 /*
1033  * Find the given root device.
1034  * This is much like config_search, but there is no parent.
1035  * Don't bother with multiple cfdata tables; the root node
1036  * must always be in the initial table.
1037  */
1038 cfdata_t
1039 config_rootsearch(cfsubmatch_t fn, const char *rootname, void *aux)
1040 {
1041 	cfdata_t cf;
1042 	const short *p;
1043 	struct matchinfo m;
1044 
1045 	m.fn = fn;
1046 	m.parent = ROOT;
1047 	m.aux = aux;
1048 	m.match = NULL;
1049 	m.pri = 0;
1050 	m.locs = 0;
1051 	/*
1052 	 * Look at root entries for matching name.  We do not bother
1053 	 * with found-state here since only one root should ever be
1054 	 * searched (and it must be done first).
1055 	 */
1056 	for (p = cfroots; *p >= 0; p++) {
1057 		cf = &cfdata[*p];
1058 		if (strcmp(cf->cf_name, rootname) == 0)
1059 			mapply(&m, cf);
1060 	}
1061 	return m.match;
1062 }
1063 
1064 static const char * const msgs[3] = { "", " not configured\n", " unsupported\n" };
1065 
1066 /*
1067  * The given `aux' argument describes a device that has been found
1068  * on the given parent, but not necessarily configured.  Locate the
1069  * configuration data for that device (using the submatch function
1070  * provided, or using candidates' cd_match configuration driver
1071  * functions) and attach it, and return its device_t.  If the device was
1072  * not configured, call the given `print' function and return NULL.
1073  */
1074 device_t
1075 config_found_sm_loc(device_t parent,
1076 		const char *ifattr, const int *locs, void *aux,
1077 		cfprint_t print, cfsubmatch_t submatch)
1078 {
1079 	cfdata_t cf;
1080 
1081 	if ((cf = config_search_loc(submatch, parent, ifattr, locs, aux)))
1082 		return(config_attach_loc(parent, cf, locs, aux, print));
1083 	if (print) {
1084 		if (config_do_twiddle && cold)
1085 			twiddle();
1086 		aprint_normal("%s", msgs[(*print)(aux, device_xname(parent))]);
1087 	}
1088 
1089 	/*
1090 	 * This has the effect of mixing in a single timestamp to the
1091 	 * entropy pool.  Experiments indicate the estimator will almost
1092 	 * always attribute one bit of entropy to this sample; analysis
1093 	 * of device attach/detach timestamps on FreeBSD indicates 4
1094 	 * bits of entropy/sample so this seems appropriately conservative.
1095 	 */
1096 	rnd_add_uint32(&rnd_autoconf_source, 0);
1097 	return NULL;
1098 }
1099 
1100 device_t
1101 config_found_ia(device_t parent, const char *ifattr, void *aux,
1102     cfprint_t print)
1103 {
1104 
1105 	return config_found_sm_loc(parent, ifattr, NULL, aux, print, NULL);
1106 }
1107 
1108 device_t
1109 config_found(device_t parent, void *aux, cfprint_t print)
1110 {
1111 
1112 	return config_found_sm_loc(parent, NULL, NULL, aux, print, NULL);
1113 }
1114 
1115 /*
1116  * As above, but for root devices.
1117  */
1118 device_t
1119 config_rootfound(const char *rootname, void *aux)
1120 {
1121 	cfdata_t cf;
1122 
1123 	if ((cf = config_rootsearch(NULL, rootname, aux)) != NULL)
1124 		return config_attach(ROOT, cf, aux, NULL);
1125 	aprint_error("root device %s not configured\n", rootname);
1126 	return NULL;
1127 }
1128 
1129 /* just like sprintf(buf, "%d") except that it works from the end */
1130 static char *
1131 number(char *ep, int n)
1132 {
1133 
1134 	*--ep = 0;
1135 	while (n >= 10) {
1136 		*--ep = (n % 10) + '0';
1137 		n /= 10;
1138 	}
1139 	*--ep = n + '0';
1140 	return ep;
1141 }
1142 
1143 /*
1144  * Expand the size of the cd_devs array if necessary.
1145  *
1146  * The caller must hold alldevs_mtx. config_makeroom() may release and
1147  * re-acquire alldevs_mtx, so callers should re-check conditions such
1148  * as alldevs_nwrite == 0 and alldevs_nread == 0 when config_makeroom()
1149  * returns.
1150  */
1151 static void
1152 config_makeroom(int n, struct cfdriver *cd)
1153 {
1154 	int ondevs, nndevs;
1155 	device_t *osp, *nsp;
1156 
1157 	alldevs_nwrite++;
1158 
1159 	for (nndevs = MAX(4, cd->cd_ndevs); nndevs <= n; nndevs += nndevs)
1160 		;
1161 
1162 	while (n >= cd->cd_ndevs) {
1163 		/*
1164 		 * Need to expand the array.
1165 		 */
1166 		ondevs = cd->cd_ndevs;
1167 		osp = cd->cd_devs;
1168 
1169 		/* Release alldevs_mtx around allocation, which may
1170 		 * sleep.
1171 		 */
1172 		mutex_exit(&alldevs_mtx);
1173 		nsp = kmem_alloc(sizeof(device_t[nndevs]), KM_SLEEP);
1174 		if (nsp == NULL)
1175 			panic("%s: could not expand cd_devs", __func__);
1176 		mutex_enter(&alldevs_mtx);
1177 
1178 		/* If another thread moved the array while we did
1179 		 * not hold alldevs_mtx, try again.
1180 		 */
1181 		if (cd->cd_devs != osp) {
1182 			mutex_exit(&alldevs_mtx);
1183 			kmem_free(nsp, sizeof(device_t[nndevs]));
1184 			mutex_enter(&alldevs_mtx);
1185 			continue;
1186 		}
1187 
1188 		memset(nsp + ondevs, 0, sizeof(device_t[nndevs - ondevs]));
1189 		if (ondevs != 0)
1190 			memcpy(nsp, cd->cd_devs, sizeof(device_t[ondevs]));
1191 
1192 		cd->cd_ndevs = nndevs;
1193 		cd->cd_devs = nsp;
1194 		if (ondevs != 0) {
1195 			mutex_exit(&alldevs_mtx);
1196 			kmem_free(osp, sizeof(device_t[ondevs]));
1197 			mutex_enter(&alldevs_mtx);
1198 		}
1199 	}
1200 	alldevs_nwrite--;
1201 }
1202 
1203 /*
1204  * Put dev into the devices list.
1205  */
1206 static void
1207 config_devlink(device_t dev)
1208 {
1209 	int s;
1210 
1211 	s = config_alldevs_lock();
1212 
1213 	KASSERT(device_cfdriver(dev)->cd_devs[dev->dv_unit] == dev);
1214 
1215 	dev->dv_add_gen = alldevs_gen;
1216 	/* It is safe to add a device to the tail of the list while
1217 	 * readers and writers are in the list.
1218 	 */
1219 	TAILQ_INSERT_TAIL(&alldevs, dev, dv_list);
1220 	config_alldevs_unlock(s);
1221 }
1222 
1223 static void
1224 config_devfree(device_t dev)
1225 {
1226 	int priv = (dev->dv_flags & DVF_PRIV_ALLOC);
1227 
1228 	if (dev->dv_cfattach->ca_devsize > 0)
1229 		kmem_free(dev->dv_private, dev->dv_cfattach->ca_devsize);
1230 	if (priv)
1231 		kmem_free(dev, sizeof(*dev));
1232 }
1233 
1234 /*
1235  * Caller must hold alldevs_mtx.
1236  */
1237 static void
1238 config_devunlink(device_t dev, struct devicelist *garbage)
1239 {
1240 	struct device_garbage *dg = &dev->dv_garbage;
1241 	cfdriver_t cd = device_cfdriver(dev);
1242 	int i;
1243 
1244 	KASSERT(mutex_owned(&alldevs_mtx));
1245 
1246  	/* Unlink from device list.  Link to garbage list. */
1247 	TAILQ_REMOVE(&alldevs, dev, dv_list);
1248 	TAILQ_INSERT_TAIL(garbage, dev, dv_list);
1249 
1250 	/* Remove from cfdriver's array. */
1251 	cd->cd_devs[dev->dv_unit] = NULL;
1252 
1253 	/*
1254 	 * If the device now has no units in use, unlink its softc array.
1255 	 */
1256 	for (i = 0; i < cd->cd_ndevs; i++) {
1257 		if (cd->cd_devs[i] != NULL)
1258 			break;
1259 	}
1260 	/* Nothing found.  Unlink, now.  Deallocate, later. */
1261 	if (i == cd->cd_ndevs) {
1262 		dg->dg_ndevs = cd->cd_ndevs;
1263 		dg->dg_devs = cd->cd_devs;
1264 		cd->cd_devs = NULL;
1265 		cd->cd_ndevs = 0;
1266 	}
1267 }
1268 
1269 static void
1270 config_devdelete(device_t dev)
1271 {
1272 	struct device_garbage *dg = &dev->dv_garbage;
1273 	device_lock_t dvl = device_getlock(dev);
1274 
1275 	if (dg->dg_devs != NULL)
1276 		kmem_free(dg->dg_devs, sizeof(device_t[dg->dg_ndevs]));
1277 
1278 	cv_destroy(&dvl->dvl_cv);
1279 	mutex_destroy(&dvl->dvl_mtx);
1280 
1281 	KASSERT(dev->dv_properties != NULL);
1282 	prop_object_release(dev->dv_properties);
1283 
1284 	if (dev->dv_activity_handlers)
1285 		panic("%s with registered handlers", __func__);
1286 
1287 	if (dev->dv_locators) {
1288 		size_t amount = *--dev->dv_locators;
1289 		kmem_free(dev->dv_locators, amount);
1290 	}
1291 
1292 	config_devfree(dev);
1293 }
1294 
1295 static int
1296 config_unit_nextfree(cfdriver_t cd, cfdata_t cf)
1297 {
1298 	int unit;
1299 
1300 	if (cf->cf_fstate == FSTATE_STAR) {
1301 		for (unit = cf->cf_unit; unit < cd->cd_ndevs; unit++)
1302 			if (cd->cd_devs[unit] == NULL)
1303 				break;
1304 		/*
1305 		 * unit is now the unit of the first NULL device pointer,
1306 		 * or max(cd->cd_ndevs,cf->cf_unit).
1307 		 */
1308 	} else {
1309 		unit = cf->cf_unit;
1310 		if (unit < cd->cd_ndevs && cd->cd_devs[unit] != NULL)
1311 			unit = -1;
1312 	}
1313 	return unit;
1314 }
1315 
1316 static int
1317 config_unit_alloc(device_t dev, cfdriver_t cd, cfdata_t cf)
1318 {
1319 	struct alldevs_foray af;
1320 	int unit;
1321 
1322 	config_alldevs_enter(&af);
1323 	for (;;) {
1324 		unit = config_unit_nextfree(cd, cf);
1325 		if (unit == -1)
1326 			break;
1327 		if (unit < cd->cd_ndevs) {
1328 			cd->cd_devs[unit] = dev;
1329 			dev->dv_unit = unit;
1330 			break;
1331 		}
1332 		config_makeroom(unit, cd);
1333 	}
1334 	config_alldevs_exit(&af);
1335 
1336 	return unit;
1337 }
1338 
1339 static device_t
1340 config_devalloc(const device_t parent, const cfdata_t cf, const int *locs)
1341 {
1342 	cfdriver_t cd;
1343 	cfattach_t ca;
1344 	size_t lname, lunit;
1345 	const char *xunit;
1346 	int myunit;
1347 	char num[10];
1348 	device_t dev;
1349 	void *dev_private;
1350 	const struct cfiattrdata *ia;
1351 	device_lock_t dvl;
1352 
1353 	cd = config_cfdriver_lookup(cf->cf_name);
1354 	if (cd == NULL)
1355 		return NULL;
1356 
1357 	ca = config_cfattach_lookup_cd(cd, cf->cf_atname);
1358 	if (ca == NULL)
1359 		return NULL;
1360 
1361 	if ((ca->ca_flags & DVF_PRIV_ALLOC) == 0 &&
1362 	    ca->ca_devsize < sizeof(struct device))
1363 		panic("config_devalloc: %s (%zu < %zu)", cf->cf_atname,
1364 		    ca->ca_devsize, sizeof(struct device));
1365 
1366 	/* get memory for all device vars */
1367 	KASSERT((ca->ca_flags & DVF_PRIV_ALLOC) || ca->ca_devsize >= sizeof(struct device));
1368 	if (ca->ca_devsize > 0) {
1369 		dev_private = kmem_zalloc(ca->ca_devsize, KM_SLEEP);
1370 		if (dev_private == NULL)
1371 			panic("config_devalloc: memory allocation for device softc failed");
1372 	} else {
1373 		KASSERT(ca->ca_flags & DVF_PRIV_ALLOC);
1374 		dev_private = NULL;
1375 	}
1376 
1377 	if ((ca->ca_flags & DVF_PRIV_ALLOC) != 0) {
1378 		dev = kmem_zalloc(sizeof(*dev), KM_SLEEP);
1379 	} else {
1380 		dev = dev_private;
1381 #ifdef DIAGNOSTIC
1382 		printf("%s has not been converted to device_t\n", cd->cd_name);
1383 #endif
1384 	}
1385 	if (dev == NULL)
1386 		panic("config_devalloc: memory allocation for device_t failed");
1387 
1388 	dev->dv_class = cd->cd_class;
1389 	dev->dv_cfdata = cf;
1390 	dev->dv_cfdriver = cd;
1391 	dev->dv_cfattach = ca;
1392 	dev->dv_activity_count = 0;
1393 	dev->dv_activity_handlers = NULL;
1394 	dev->dv_private = dev_private;
1395 	dev->dv_flags = ca->ca_flags;	/* inherit flags from class */
1396 
1397 	myunit = config_unit_alloc(dev, cd, cf);
1398 	if (myunit == -1) {
1399 		config_devfree(dev);
1400 		return NULL;
1401 	}
1402 
1403 	/* compute length of name and decimal expansion of unit number */
1404 	lname = strlen(cd->cd_name);
1405 	xunit = number(&num[sizeof(num)], myunit);
1406 	lunit = &num[sizeof(num)] - xunit;
1407 	if (lname + lunit > sizeof(dev->dv_xname))
1408 		panic("config_devalloc: device name too long");
1409 
1410 	dvl = device_getlock(dev);
1411 
1412 	mutex_init(&dvl->dvl_mtx, MUTEX_DEFAULT, IPL_NONE);
1413 	cv_init(&dvl->dvl_cv, "pmfsusp");
1414 
1415 	memcpy(dev->dv_xname, cd->cd_name, lname);
1416 	memcpy(dev->dv_xname + lname, xunit, lunit);
1417 	dev->dv_parent = parent;
1418 	if (parent != NULL)
1419 		dev->dv_depth = parent->dv_depth + 1;
1420 	else
1421 		dev->dv_depth = 0;
1422 	dev->dv_flags |= DVF_ACTIVE;	/* always initially active */
1423 	if (locs) {
1424 		KASSERT(parent); /* no locators at root */
1425 		ia = cfiattr_lookup(cfdata_ifattr(cf), parent->dv_cfdriver);
1426 		dev->dv_locators =
1427 		    kmem_alloc(sizeof(int [ia->ci_loclen + 1]), KM_SLEEP);
1428 		*dev->dv_locators++ = sizeof(int [ia->ci_loclen + 1]);
1429 		memcpy(dev->dv_locators, locs, sizeof(int [ia->ci_loclen]));
1430 	}
1431 	dev->dv_properties = prop_dictionary_create();
1432 	KASSERT(dev->dv_properties != NULL);
1433 
1434 	prop_dictionary_set_cstring_nocopy(dev->dv_properties,
1435 	    "device-driver", dev->dv_cfdriver->cd_name);
1436 	prop_dictionary_set_uint16(dev->dv_properties,
1437 	    "device-unit", dev->dv_unit);
1438 
1439 	if (dev->dv_cfdriver->cd_attrs != NULL)
1440 		config_add_attrib_dict(dev);
1441 
1442 	return dev;
1443 }
1444 
1445 /*
1446  * Create an array of device attach attributes and add it
1447  * to the device's dv_properties dictionary.
1448  *
1449  * <key>interface-attributes</key>
1450  * <array>
1451  *    <dict>
1452  *       <key>attribute-name</key>
1453  *       <string>foo</string>
1454  *       <key>locators</key>
1455  *       <array>
1456  *          <dict>
1457  *             <key>loc-name</key>
1458  *             <string>foo-loc1</string>
1459  *          </dict>
1460  *          <dict>
1461  *             <key>loc-name</key>
1462  *             <string>foo-loc2</string>
1463  *             <key>default</key>
1464  *             <string>foo-loc2-default</string>
1465  *          </dict>
1466  *          ...
1467  *       </array>
1468  *    </dict>
1469  *    ...
1470  * </array>
1471  */
1472 
1473 static void
1474 config_add_attrib_dict(device_t dev)
1475 {
1476 	int i, j;
1477 	const struct cfiattrdata *ci;
1478 	prop_dictionary_t attr_dict, loc_dict;
1479 	prop_array_t attr_array, loc_array;
1480 
1481 	if ((attr_array = prop_array_create()) == NULL)
1482 		return;
1483 
1484 	for (i = 0; ; i++) {
1485 		if ((ci = dev->dv_cfdriver->cd_attrs[i]) == NULL)
1486 			break;
1487 		if ((attr_dict = prop_dictionary_create()) == NULL)
1488 			break;
1489 		prop_dictionary_set_cstring_nocopy(attr_dict, "attribute-name",
1490 		    ci->ci_name);
1491 
1492 		/* Create an array of the locator names and defaults */
1493 
1494 		if (ci->ci_loclen != 0 &&
1495 		    (loc_array = prop_array_create()) != NULL) {
1496 			for (j = 0; j < ci->ci_loclen; j++) {
1497 				loc_dict = prop_dictionary_create();
1498 				if (loc_dict == NULL)
1499 					continue;
1500 				prop_dictionary_set_cstring_nocopy(loc_dict,
1501 				    "loc-name", ci->ci_locdesc[j].cld_name);
1502 				if (ci->ci_locdesc[j].cld_defaultstr != NULL)
1503 					prop_dictionary_set_cstring_nocopy(
1504 					    loc_dict, "default",
1505 					    ci->ci_locdesc[j].cld_defaultstr);
1506 				prop_array_set(loc_array, j, loc_dict);
1507 				prop_object_release(loc_dict);
1508 			}
1509 			prop_dictionary_set_and_rel(attr_dict, "locators",
1510 			    loc_array);
1511 		}
1512 		prop_array_add(attr_array, attr_dict);
1513 		prop_object_release(attr_dict);
1514 	}
1515 	if (i == 0)
1516 		prop_object_release(attr_array);
1517 	else
1518 		prop_dictionary_set_and_rel(dev->dv_properties,
1519 		    "interface-attributes", attr_array);
1520 
1521 	return;
1522 }
1523 
1524 /*
1525  * Attach a found device.
1526  */
1527 device_t
1528 config_attach_loc(device_t parent, cfdata_t cf,
1529 	const int *locs, void *aux, cfprint_t print)
1530 {
1531 	device_t dev;
1532 	struct cftable *ct;
1533 	const char *drvname;
1534 
1535 	dev = config_devalloc(parent, cf, locs);
1536 	if (!dev)
1537 		panic("config_attach: allocation of device softc failed");
1538 
1539 	/* XXX redundant - see below? */
1540 	if (cf->cf_fstate != FSTATE_STAR) {
1541 		KASSERT(cf->cf_fstate == FSTATE_NOTFOUND);
1542 		cf->cf_fstate = FSTATE_FOUND;
1543 	}
1544 
1545 	config_devlink(dev);
1546 
1547 	if (config_do_twiddle && cold)
1548 		twiddle();
1549 	else
1550 		aprint_naive("Found ");
1551 	/*
1552 	 * We want the next two printfs for normal, verbose, and quiet,
1553 	 * but not silent (in which case, we're twiddling, instead).
1554 	 */
1555 	if (parent == ROOT) {
1556 		aprint_naive("%s (root)", device_xname(dev));
1557 		aprint_normal("%s (root)", device_xname(dev));
1558 	} else {
1559 		aprint_naive("%s at %s", device_xname(dev), device_xname(parent));
1560 		aprint_normal("%s at %s", device_xname(dev), device_xname(parent));
1561 		if (print)
1562 			(void) (*print)(aux, NULL);
1563 	}
1564 
1565 	/*
1566 	 * Before attaching, clobber any unfound devices that are
1567 	 * otherwise identical.
1568 	 * XXX code above is redundant?
1569 	 */
1570 	drvname = dev->dv_cfdriver->cd_name;
1571 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
1572 		for (cf = ct->ct_cfdata; cf->cf_name; cf++) {
1573 			if (STREQ(cf->cf_name, drvname) &&
1574 			    cf->cf_unit == dev->dv_unit) {
1575 				if (cf->cf_fstate == FSTATE_NOTFOUND)
1576 					cf->cf_fstate = FSTATE_FOUND;
1577 			}
1578 		}
1579 	}
1580 	device_register(dev, aux);
1581 
1582 	/* Let userland know */
1583 	devmon_report_device(dev, true);
1584 
1585 	(*dev->dv_cfattach->ca_attach)(parent, dev, aux);
1586 
1587 	if (!device_pmf_is_registered(dev))
1588 		aprint_debug_dev(dev, "WARNING: power management not supported\n");
1589 
1590 	config_process_deferred(&deferred_config_queue, dev);
1591 
1592 	device_register_post_config(dev, aux);
1593 	return dev;
1594 }
1595 
1596 device_t
1597 config_attach(device_t parent, cfdata_t cf, void *aux, cfprint_t print)
1598 {
1599 
1600 	return config_attach_loc(parent, cf, NULL, aux, print);
1601 }
1602 
1603 /*
1604  * As above, but for pseudo-devices.  Pseudo-devices attached in this
1605  * way are silently inserted into the device tree, and their children
1606  * attached.
1607  *
1608  * Note that because pseudo-devices are attached silently, any information
1609  * the attach routine wishes to print should be prefixed with the device
1610  * name by the attach routine.
1611  */
1612 device_t
1613 config_attach_pseudo(cfdata_t cf)
1614 {
1615 	device_t dev;
1616 
1617 	dev = config_devalloc(ROOT, cf, NULL);
1618 	if (!dev)
1619 		return NULL;
1620 
1621 	/* XXX mark busy in cfdata */
1622 
1623 	if (cf->cf_fstate != FSTATE_STAR) {
1624 		KASSERT(cf->cf_fstate == FSTATE_NOTFOUND);
1625 		cf->cf_fstate = FSTATE_FOUND;
1626 	}
1627 
1628 	config_devlink(dev);
1629 
1630 #if 0	/* XXXJRT not yet */
1631 	device_register(dev, NULL);	/* like a root node */
1632 #endif
1633 
1634 	/* Let userland know */
1635 	devmon_report_device(dev, true);
1636 
1637 	(*dev->dv_cfattach->ca_attach)(ROOT, dev, NULL);
1638 
1639 	config_process_deferred(&deferred_config_queue, dev);
1640 	return dev;
1641 }
1642 
1643 /*
1644  * Caller must hold alldevs_mtx.
1645  */
1646 static void
1647 config_collect_garbage(struct devicelist *garbage)
1648 {
1649 	device_t dv;
1650 
1651 	KASSERT(!cpu_intr_p());
1652 	KASSERT(!cpu_softintr_p());
1653 	KASSERT(mutex_owned(&alldevs_mtx));
1654 
1655 	while (alldevs_nwrite == 0 && alldevs_nread == 0 && alldevs_garbage) {
1656 		TAILQ_FOREACH(dv, &alldevs, dv_list) {
1657 			if (dv->dv_del_gen != 0)
1658 				break;
1659 		}
1660 		if (dv == NULL) {
1661 			alldevs_garbage = false;
1662 			break;
1663 		}
1664 		config_devunlink(dv, garbage);
1665 	}
1666 	KASSERT(mutex_owned(&alldevs_mtx));
1667 }
1668 
1669 static void
1670 config_dump_garbage(struct devicelist *garbage)
1671 {
1672 	device_t dv;
1673 
1674 	while ((dv = TAILQ_FIRST(garbage)) != NULL) {
1675 		TAILQ_REMOVE(garbage, dv, dv_list);
1676 		config_devdelete(dv);
1677 	}
1678 }
1679 
1680 /*
1681  * Detach a device.  Optionally forced (e.g. because of hardware
1682  * removal) and quiet.  Returns zero if successful, non-zero
1683  * (an error code) otherwise.
1684  *
1685  * Note that this code wants to be run from a process context, so
1686  * that the detach can sleep to allow processes which have a device
1687  * open to run and unwind their stacks.
1688  */
1689 int
1690 config_detach(device_t dev, int flags)
1691 {
1692 	struct alldevs_foray af;
1693 	struct cftable *ct;
1694 	cfdata_t cf;
1695 	const struct cfattach *ca;
1696 	struct cfdriver *cd;
1697 #ifdef DIAGNOSTIC
1698 	device_t d;
1699 #endif
1700 	int rv = 0, s;
1701 
1702 #ifdef DIAGNOSTIC
1703 	cf = dev->dv_cfdata;
1704 	if (cf != NULL && cf->cf_fstate != FSTATE_FOUND &&
1705 	    cf->cf_fstate != FSTATE_STAR)
1706 		panic("config_detach: %s: bad device fstate %d",
1707 		    device_xname(dev), cf ? cf->cf_fstate : -1);
1708 #endif
1709 	cd = dev->dv_cfdriver;
1710 	KASSERT(cd != NULL);
1711 
1712 	ca = dev->dv_cfattach;
1713 	KASSERT(ca != NULL);
1714 
1715 	s = config_alldevs_lock();
1716 	if (dev->dv_del_gen != 0) {
1717 		config_alldevs_unlock(s);
1718 #ifdef DIAGNOSTIC
1719 		printf("%s: %s is already detached\n", __func__,
1720 		    device_xname(dev));
1721 #endif /* DIAGNOSTIC */
1722 		return ENOENT;
1723 	}
1724 	alldevs_nwrite++;
1725 	config_alldevs_unlock(s);
1726 
1727 	if (!detachall &&
1728 	    (flags & (DETACH_SHUTDOWN|DETACH_FORCE)) == DETACH_SHUTDOWN &&
1729 	    (dev->dv_flags & DVF_DETACH_SHUTDOWN) == 0) {
1730 		rv = EOPNOTSUPP;
1731 	} else if (ca->ca_detach != NULL) {
1732 		rv = (*ca->ca_detach)(dev, flags);
1733 	} else
1734 		rv = EOPNOTSUPP;
1735 
1736 	/*
1737 	 * If it was not possible to detach the device, then we either
1738 	 * panic() (for the forced but failed case), or return an error.
1739 	 *
1740 	 * If it was possible to detach the device, ensure that the
1741 	 * device is deactivated.
1742 	 */
1743 	if (rv == 0)
1744 		dev->dv_flags &= ~DVF_ACTIVE;
1745 	else if ((flags & DETACH_FORCE) == 0)
1746 		goto out;
1747 	else {
1748 		panic("config_detach: forced detach of %s failed (%d)",
1749 		    device_xname(dev), rv);
1750 	}
1751 
1752 	/*
1753 	 * The device has now been successfully detached.
1754 	 */
1755 
1756 	/* Let userland know */
1757 	devmon_report_device(dev, false);
1758 
1759 #ifdef DIAGNOSTIC
1760 	/*
1761 	 * Sanity: If you're successfully detached, you should have no
1762 	 * children.  (Note that because children must be attached
1763 	 * after parents, we only need to search the latter part of
1764 	 * the list.)
1765 	 */
1766 	for (d = TAILQ_NEXT(dev, dv_list); d != NULL;
1767 	    d = TAILQ_NEXT(d, dv_list)) {
1768 		if (d->dv_parent == dev && d->dv_del_gen == 0) {
1769 			printf("config_detach: detached device %s"
1770 			    " has children %s\n", device_xname(dev), device_xname(d));
1771 			panic("config_detach");
1772 		}
1773 	}
1774 #endif
1775 
1776 	/* notify the parent that the child is gone */
1777 	if (dev->dv_parent) {
1778 		device_t p = dev->dv_parent;
1779 		if (p->dv_cfattach->ca_childdetached)
1780 			(*p->dv_cfattach->ca_childdetached)(p, dev);
1781 	}
1782 
1783 	/*
1784 	 * Mark cfdata to show that the unit can be reused, if possible.
1785 	 */
1786 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
1787 		for (cf = ct->ct_cfdata; cf->cf_name; cf++) {
1788 			if (STREQ(cf->cf_name, cd->cd_name)) {
1789 				if (cf->cf_fstate == FSTATE_FOUND &&
1790 				    cf->cf_unit == dev->dv_unit)
1791 					cf->cf_fstate = FSTATE_NOTFOUND;
1792 			}
1793 		}
1794 	}
1795 
1796 	if (dev->dv_cfdata != NULL && (flags & DETACH_QUIET) == 0)
1797 		aprint_normal_dev(dev, "detached\n");
1798 
1799 out:
1800 	config_alldevs_enter(&af);
1801 	KASSERT(alldevs_nwrite != 0);
1802 	--alldevs_nwrite;
1803 	if (rv == 0 && dev->dv_del_gen == 0) {
1804 		if (alldevs_nwrite == 0 && alldevs_nread == 0)
1805 			config_devunlink(dev, &af.af_garbage);
1806 		else {
1807 			dev->dv_del_gen = alldevs_gen;
1808 			alldevs_garbage = true;
1809 		}
1810 	}
1811 	config_alldevs_exit(&af);
1812 
1813 	return rv;
1814 }
1815 
1816 int
1817 config_detach_children(device_t parent, int flags)
1818 {
1819 	device_t dv;
1820 	deviter_t di;
1821 	int error = 0;
1822 
1823 	for (dv = deviter_first(&di, DEVITER_F_RW); dv != NULL;
1824 	     dv = deviter_next(&di)) {
1825 		if (device_parent(dv) != parent)
1826 			continue;
1827 		if ((error = config_detach(dv, flags)) != 0)
1828 			break;
1829 	}
1830 	deviter_release(&di);
1831 	return error;
1832 }
1833 
1834 device_t
1835 shutdown_first(struct shutdown_state *s)
1836 {
1837 	if (!s->initialized) {
1838 		deviter_init(&s->di, DEVITER_F_SHUTDOWN|DEVITER_F_LEAVES_FIRST);
1839 		s->initialized = true;
1840 	}
1841 	return shutdown_next(s);
1842 }
1843 
1844 device_t
1845 shutdown_next(struct shutdown_state *s)
1846 {
1847 	device_t dv;
1848 
1849 	while ((dv = deviter_next(&s->di)) != NULL && !device_is_active(dv))
1850 		;
1851 
1852 	if (dv == NULL)
1853 		s->initialized = false;
1854 
1855 	return dv;
1856 }
1857 
1858 bool
1859 config_detach_all(int how)
1860 {
1861 	static struct shutdown_state s;
1862 	device_t curdev;
1863 	bool progress = false;
1864 
1865 	if ((how & RB_NOSYNC) != 0)
1866 		return false;
1867 
1868 	for (curdev = shutdown_first(&s); curdev != NULL;
1869 	     curdev = shutdown_next(&s)) {
1870 		aprint_debug(" detaching %s, ", device_xname(curdev));
1871 		if (config_detach(curdev, DETACH_SHUTDOWN) == 0) {
1872 			progress = true;
1873 			aprint_debug("success.");
1874 		} else
1875 			aprint_debug("failed.");
1876 	}
1877 	return progress;
1878 }
1879 
1880 static bool
1881 device_is_ancestor_of(device_t ancestor, device_t descendant)
1882 {
1883 	device_t dv;
1884 
1885 	for (dv = descendant; dv != NULL; dv = device_parent(dv)) {
1886 		if (device_parent(dv) == ancestor)
1887 			return true;
1888 	}
1889 	return false;
1890 }
1891 
1892 int
1893 config_deactivate(device_t dev)
1894 {
1895 	deviter_t di;
1896 	const struct cfattach *ca;
1897 	device_t descendant;
1898 	int s, rv = 0, oflags;
1899 
1900 	for (descendant = deviter_first(&di, DEVITER_F_ROOT_FIRST);
1901 	     descendant != NULL;
1902 	     descendant = deviter_next(&di)) {
1903 		if (dev != descendant &&
1904 		    !device_is_ancestor_of(dev, descendant))
1905 			continue;
1906 
1907 		if ((descendant->dv_flags & DVF_ACTIVE) == 0)
1908 			continue;
1909 
1910 		ca = descendant->dv_cfattach;
1911 		oflags = descendant->dv_flags;
1912 
1913 		descendant->dv_flags &= ~DVF_ACTIVE;
1914 		if (ca->ca_activate == NULL)
1915 			continue;
1916 		s = splhigh();
1917 		rv = (*ca->ca_activate)(descendant, DVACT_DEACTIVATE);
1918 		splx(s);
1919 		if (rv != 0)
1920 			descendant->dv_flags = oflags;
1921 	}
1922 	deviter_release(&di);
1923 	return rv;
1924 }
1925 
1926 /*
1927  * Defer the configuration of the specified device until all
1928  * of its parent's devices have been attached.
1929  */
1930 void
1931 config_defer(device_t dev, void (*func)(device_t))
1932 {
1933 	struct deferred_config *dc;
1934 
1935 	if (dev->dv_parent == NULL)
1936 		panic("config_defer: can't defer config of a root device");
1937 
1938 #ifdef DIAGNOSTIC
1939 	TAILQ_FOREACH(dc, &deferred_config_queue, dc_queue) {
1940 		if (dc->dc_dev == dev)
1941 			panic("config_defer: deferred twice");
1942 	}
1943 #endif
1944 
1945 	dc = kmem_alloc(sizeof(*dc), KM_SLEEP);
1946 	if (dc == NULL)
1947 		panic("config_defer: unable to allocate callback");
1948 
1949 	dc->dc_dev = dev;
1950 	dc->dc_func = func;
1951 	TAILQ_INSERT_TAIL(&deferred_config_queue, dc, dc_queue);
1952 	config_pending_incr(dev);
1953 }
1954 
1955 /*
1956  * Defer some autoconfiguration for a device until after interrupts
1957  * are enabled.
1958  */
1959 void
1960 config_interrupts(device_t dev, void (*func)(device_t))
1961 {
1962 	struct deferred_config *dc;
1963 
1964 	/*
1965 	 * If interrupts are enabled, callback now.
1966 	 */
1967 	if (cold == 0) {
1968 		(*func)(dev);
1969 		return;
1970 	}
1971 
1972 #ifdef DIAGNOSTIC
1973 	TAILQ_FOREACH(dc, &interrupt_config_queue, dc_queue) {
1974 		if (dc->dc_dev == dev)
1975 			panic("config_interrupts: deferred twice");
1976 	}
1977 #endif
1978 
1979 	dc = kmem_alloc(sizeof(*dc), KM_SLEEP);
1980 	if (dc == NULL)
1981 		panic("config_interrupts: unable to allocate callback");
1982 
1983 	dc->dc_dev = dev;
1984 	dc->dc_func = func;
1985 	TAILQ_INSERT_TAIL(&interrupt_config_queue, dc, dc_queue);
1986 	config_pending_incr(dev);
1987 }
1988 
1989 /*
1990  * Defer some autoconfiguration for a device until after root file system
1991  * is mounted (to load firmware etc).
1992  */
1993 void
1994 config_mountroot(device_t dev, void (*func)(device_t))
1995 {
1996 	struct deferred_config *dc;
1997 
1998 	/*
1999 	 * If root file system is mounted, callback now.
2000 	 */
2001 	if (root_is_mounted) {
2002 		(*func)(dev);
2003 		return;
2004 	}
2005 
2006 #ifdef DIAGNOSTIC
2007 	TAILQ_FOREACH(dc, &mountroot_config_queue, dc_queue) {
2008 		if (dc->dc_dev == dev)
2009 			panic("%s: deferred twice", __func__);
2010 	}
2011 #endif
2012 
2013 	dc = kmem_alloc(sizeof(*dc), KM_SLEEP);
2014 	if (dc == NULL)
2015 		panic("%s: unable to allocate callback", __func__);
2016 
2017 	dc->dc_dev = dev;
2018 	dc->dc_func = func;
2019 	TAILQ_INSERT_TAIL(&mountroot_config_queue, dc, dc_queue);
2020 }
2021 
2022 /*
2023  * Process a deferred configuration queue.
2024  */
2025 static void
2026 config_process_deferred(struct deferred_config_head *queue,
2027     device_t parent)
2028 {
2029 	struct deferred_config *dc, *ndc;
2030 
2031 	for (dc = TAILQ_FIRST(queue); dc != NULL; dc = ndc) {
2032 		ndc = TAILQ_NEXT(dc, dc_queue);
2033 		if (parent == NULL || dc->dc_dev->dv_parent == parent) {
2034 			TAILQ_REMOVE(queue, dc, dc_queue);
2035 			(*dc->dc_func)(dc->dc_dev);
2036 			config_pending_decr(dc->dc_dev);
2037 			kmem_free(dc, sizeof(*dc));
2038 		}
2039 	}
2040 }
2041 
2042 /*
2043  * Manipulate the config_pending semaphore.
2044  */
2045 void
2046 config_pending_incr(device_t dev)
2047 {
2048 
2049 	mutex_enter(&config_misc_lock);
2050 	config_pending++;
2051 #ifdef DEBUG_AUTOCONF
2052 	printf("%s: %s %d\n", __func__, device_xname(dev), config_pending);
2053 #endif
2054 	mutex_exit(&config_misc_lock);
2055 }
2056 
2057 void
2058 config_pending_decr(device_t dev)
2059 {
2060 
2061 #ifdef DIAGNOSTIC
2062 	if (config_pending == 0)
2063 		panic("config_pending_decr: config_pending == 0");
2064 #endif
2065 	mutex_enter(&config_misc_lock);
2066 	config_pending--;
2067 #ifdef DEBUG_AUTOCONF
2068 	printf("%s: %s %d\n", __func__, device_xname(dev), config_pending);
2069 #endif
2070 	if (config_pending == 0)
2071 		cv_broadcast(&config_misc_cv);
2072 	mutex_exit(&config_misc_lock);
2073 }
2074 
2075 /*
2076  * Register a "finalization" routine.  Finalization routines are
2077  * called iteratively once all real devices have been found during
2078  * autoconfiguration, for as long as any one finalizer has done
2079  * any work.
2080  */
2081 int
2082 config_finalize_register(device_t dev, int (*fn)(device_t))
2083 {
2084 	struct finalize_hook *f;
2085 
2086 	/*
2087 	 * If finalization has already been done, invoke the
2088 	 * callback function now.
2089 	 */
2090 	if (config_finalize_done) {
2091 		while ((*fn)(dev) != 0)
2092 			/* loop */ ;
2093 	}
2094 
2095 	/* Ensure this isn't already on the list. */
2096 	TAILQ_FOREACH(f, &config_finalize_list, f_list) {
2097 		if (f->f_func == fn && f->f_dev == dev)
2098 			return EEXIST;
2099 	}
2100 
2101 	f = kmem_alloc(sizeof(*f), KM_SLEEP);
2102 	f->f_func = fn;
2103 	f->f_dev = dev;
2104 	TAILQ_INSERT_TAIL(&config_finalize_list, f, f_list);
2105 
2106 	return 0;
2107 }
2108 
2109 void
2110 config_finalize(void)
2111 {
2112 	struct finalize_hook *f;
2113 	struct pdevinit *pdev;
2114 	extern struct pdevinit pdevinit[];
2115 	int errcnt, rv;
2116 
2117 	/*
2118 	 * Now that device driver threads have been created, wait for
2119 	 * them to finish any deferred autoconfiguration.
2120 	 */
2121 	mutex_enter(&config_misc_lock);
2122 	while (config_pending != 0)
2123 		cv_wait(&config_misc_cv, &config_misc_lock);
2124 	mutex_exit(&config_misc_lock);
2125 
2126 	KERNEL_LOCK(1, NULL);
2127 
2128 	/* Attach pseudo-devices. */
2129 	for (pdev = pdevinit; pdev->pdev_attach != NULL; pdev++)
2130 		(*pdev->pdev_attach)(pdev->pdev_count);
2131 
2132 	/* Run the hooks until none of them does any work. */
2133 	do {
2134 		rv = 0;
2135 		TAILQ_FOREACH(f, &config_finalize_list, f_list)
2136 			rv |= (*f->f_func)(f->f_dev);
2137 	} while (rv != 0);
2138 
2139 	config_finalize_done = 1;
2140 
2141 	/* Now free all the hooks. */
2142 	while ((f = TAILQ_FIRST(&config_finalize_list)) != NULL) {
2143 		TAILQ_REMOVE(&config_finalize_list, f, f_list);
2144 		kmem_free(f, sizeof(*f));
2145 	}
2146 
2147 	KERNEL_UNLOCK_ONE(NULL);
2148 
2149 	errcnt = aprint_get_error_count();
2150 	if ((boothowto & (AB_QUIET|AB_SILENT)) != 0 &&
2151 	    (boothowto & AB_VERBOSE) == 0) {
2152 		mutex_enter(&config_misc_lock);
2153 		if (config_do_twiddle) {
2154 			config_do_twiddle = 0;
2155 			printf_nolog(" done.\n");
2156 		}
2157 		mutex_exit(&config_misc_lock);
2158 		if (errcnt != 0) {
2159 			printf("WARNING: %d error%s while detecting hardware; "
2160 			    "check system log.\n", errcnt,
2161 			    errcnt == 1 ? "" : "s");
2162 		}
2163 	}
2164 }
2165 
2166 void
2167 config_twiddle_init(void)
2168 {
2169 
2170 	if ((boothowto & (AB_SILENT|AB_VERBOSE)) == AB_SILENT) {
2171 		config_do_twiddle = 1;
2172 	}
2173 	callout_setfunc(&config_twiddle_ch, config_twiddle_fn, NULL);
2174 }
2175 
2176 void
2177 config_twiddle_fn(void *cookie)
2178 {
2179 
2180 	mutex_enter(&config_misc_lock);
2181 	if (config_do_twiddle) {
2182 		twiddle();
2183 		callout_schedule(&config_twiddle_ch, mstohz(100));
2184 	}
2185 	mutex_exit(&config_misc_lock);
2186 }
2187 
2188 static int
2189 config_alldevs_lock(void)
2190 {
2191 	mutex_enter(&alldevs_mtx);
2192 	return 0;
2193 }
2194 
2195 static void
2196 config_alldevs_enter(struct alldevs_foray *af)
2197 {
2198 	TAILQ_INIT(&af->af_garbage);
2199 	af->af_s = config_alldevs_lock();
2200 	config_collect_garbage(&af->af_garbage);
2201 }
2202 
2203 static void
2204 config_alldevs_exit(struct alldevs_foray *af)
2205 {
2206 	config_alldevs_unlock(af->af_s);
2207 	config_dump_garbage(&af->af_garbage);
2208 }
2209 
2210 /*ARGSUSED*/
2211 static void
2212 config_alldevs_unlock(int s)
2213 {
2214 	mutex_exit(&alldevs_mtx);
2215 }
2216 
2217 /*
2218  * device_lookup:
2219  *
2220  *	Look up a device instance for a given driver.
2221  */
2222 device_t
2223 device_lookup(cfdriver_t cd, int unit)
2224 {
2225 	device_t dv;
2226 	int s;
2227 
2228 	s = config_alldevs_lock();
2229 	KASSERT(mutex_owned(&alldevs_mtx));
2230 	if (unit < 0 || unit >= cd->cd_ndevs)
2231 		dv = NULL;
2232 	else if ((dv = cd->cd_devs[unit]) != NULL && dv->dv_del_gen != 0)
2233 		dv = NULL;
2234 	config_alldevs_unlock(s);
2235 
2236 	return dv;
2237 }
2238 
2239 /*
2240  * device_lookup_private:
2241  *
2242  *	Look up a softc instance for a given driver.
2243  */
2244 void *
2245 device_lookup_private(cfdriver_t cd, int unit)
2246 {
2247 
2248 	return device_private(device_lookup(cd, unit));
2249 }
2250 
2251 /*
2252  * device_find_by_xname:
2253  *
2254  *	Returns the device of the given name or NULL if it doesn't exist.
2255  */
2256 device_t
2257 device_find_by_xname(const char *name)
2258 {
2259 	device_t dv;
2260 	deviter_t di;
2261 
2262 	for (dv = deviter_first(&di, 0); dv != NULL; dv = deviter_next(&di)) {
2263 		if (strcmp(device_xname(dv), name) == 0)
2264 			break;
2265 	}
2266 	deviter_release(&di);
2267 
2268 	return dv;
2269 }
2270 
2271 /*
2272  * device_find_by_driver_unit:
2273  *
2274  *	Returns the device of the given driver name and unit or
2275  *	NULL if it doesn't exist.
2276  */
2277 device_t
2278 device_find_by_driver_unit(const char *name, int unit)
2279 {
2280 	struct cfdriver *cd;
2281 
2282 	if ((cd = config_cfdriver_lookup(name)) == NULL)
2283 		return NULL;
2284 	return device_lookup(cd, unit);
2285 }
2286 
2287 /*
2288  * Power management related functions.
2289  */
2290 
2291 bool
2292 device_pmf_is_registered(device_t dev)
2293 {
2294 	return (dev->dv_flags & DVF_POWER_HANDLERS) != 0;
2295 }
2296 
2297 bool
2298 device_pmf_driver_suspend(device_t dev, const pmf_qual_t *qual)
2299 {
2300 	if ((dev->dv_flags & DVF_DRIVER_SUSPENDED) != 0)
2301 		return true;
2302 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) == 0)
2303 		return false;
2304 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_DRIVER &&
2305 	    dev->dv_driver_suspend != NULL &&
2306 	    !(*dev->dv_driver_suspend)(dev, qual))
2307 		return false;
2308 
2309 	dev->dv_flags |= DVF_DRIVER_SUSPENDED;
2310 	return true;
2311 }
2312 
2313 bool
2314 device_pmf_driver_resume(device_t dev, const pmf_qual_t *qual)
2315 {
2316 	if ((dev->dv_flags & DVF_DRIVER_SUSPENDED) == 0)
2317 		return true;
2318 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) != 0)
2319 		return false;
2320 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_DRIVER &&
2321 	    dev->dv_driver_resume != NULL &&
2322 	    !(*dev->dv_driver_resume)(dev, qual))
2323 		return false;
2324 
2325 	dev->dv_flags &= ~DVF_DRIVER_SUSPENDED;
2326 	return true;
2327 }
2328 
2329 bool
2330 device_pmf_driver_shutdown(device_t dev, int how)
2331 {
2332 
2333 	if (*dev->dv_driver_shutdown != NULL &&
2334 	    !(*dev->dv_driver_shutdown)(dev, how))
2335 		return false;
2336 	return true;
2337 }
2338 
2339 bool
2340 device_pmf_driver_register(device_t dev,
2341     bool (*suspend)(device_t, const pmf_qual_t *),
2342     bool (*resume)(device_t, const pmf_qual_t *),
2343     bool (*shutdown)(device_t, int))
2344 {
2345 	dev->dv_driver_suspend = suspend;
2346 	dev->dv_driver_resume = resume;
2347 	dev->dv_driver_shutdown = shutdown;
2348 	dev->dv_flags |= DVF_POWER_HANDLERS;
2349 	return true;
2350 }
2351 
2352 static const char *
2353 curlwp_name(void)
2354 {
2355 	if (curlwp->l_name != NULL)
2356 		return curlwp->l_name;
2357 	else
2358 		return curlwp->l_proc->p_comm;
2359 }
2360 
2361 void
2362 device_pmf_driver_deregister(device_t dev)
2363 {
2364 	device_lock_t dvl = device_getlock(dev);
2365 
2366 	dev->dv_driver_suspend = NULL;
2367 	dev->dv_driver_resume = NULL;
2368 
2369 	mutex_enter(&dvl->dvl_mtx);
2370 	dev->dv_flags &= ~DVF_POWER_HANDLERS;
2371 	while (dvl->dvl_nlock > 0 || dvl->dvl_nwait > 0) {
2372 		/* Wake a thread that waits for the lock.  That
2373 		 * thread will fail to acquire the lock, and then
2374 		 * it will wake the next thread that waits for the
2375 		 * lock, or else it will wake us.
2376 		 */
2377 		cv_signal(&dvl->dvl_cv);
2378 		pmflock_debug(dev, __func__, __LINE__);
2379 		cv_wait(&dvl->dvl_cv, &dvl->dvl_mtx);
2380 		pmflock_debug(dev, __func__, __LINE__);
2381 	}
2382 	mutex_exit(&dvl->dvl_mtx);
2383 }
2384 
2385 bool
2386 device_pmf_driver_child_register(device_t dev)
2387 {
2388 	device_t parent = device_parent(dev);
2389 
2390 	if (parent == NULL || parent->dv_driver_child_register == NULL)
2391 		return true;
2392 	return (*parent->dv_driver_child_register)(dev);
2393 }
2394 
2395 void
2396 device_pmf_driver_set_child_register(device_t dev,
2397     bool (*child_register)(device_t))
2398 {
2399 	dev->dv_driver_child_register = child_register;
2400 }
2401 
2402 static void
2403 pmflock_debug(device_t dev, const char *func, int line)
2404 {
2405 	device_lock_t dvl = device_getlock(dev);
2406 
2407 	aprint_debug_dev(dev, "%s.%d, %s dvl_nlock %d dvl_nwait %d dv_flags %x\n",
2408 	    func, line, curlwp_name(), dvl->dvl_nlock, dvl->dvl_nwait,
2409 	    dev->dv_flags);
2410 }
2411 
2412 static bool
2413 device_pmf_lock1(device_t dev)
2414 {
2415 	device_lock_t dvl = device_getlock(dev);
2416 
2417 	while (device_pmf_is_registered(dev) &&
2418 	    dvl->dvl_nlock > 0 && dvl->dvl_holder != curlwp) {
2419 		dvl->dvl_nwait++;
2420 		pmflock_debug(dev, __func__, __LINE__);
2421 		cv_wait(&dvl->dvl_cv, &dvl->dvl_mtx);
2422 		pmflock_debug(dev, __func__, __LINE__);
2423 		dvl->dvl_nwait--;
2424 	}
2425 	if (!device_pmf_is_registered(dev)) {
2426 		pmflock_debug(dev, __func__, __LINE__);
2427 		/* We could not acquire the lock, but some other thread may
2428 		 * wait for it, also.  Wake that thread.
2429 		 */
2430 		cv_signal(&dvl->dvl_cv);
2431 		return false;
2432 	}
2433 	dvl->dvl_nlock++;
2434 	dvl->dvl_holder = curlwp;
2435 	pmflock_debug(dev, __func__, __LINE__);
2436 	return true;
2437 }
2438 
2439 bool
2440 device_pmf_lock(device_t dev)
2441 {
2442 	bool rc;
2443 	device_lock_t dvl = device_getlock(dev);
2444 
2445 	mutex_enter(&dvl->dvl_mtx);
2446 	rc = device_pmf_lock1(dev);
2447 	mutex_exit(&dvl->dvl_mtx);
2448 
2449 	return rc;
2450 }
2451 
2452 void
2453 device_pmf_unlock(device_t dev)
2454 {
2455 	device_lock_t dvl = device_getlock(dev);
2456 
2457 	KASSERT(dvl->dvl_nlock > 0);
2458 	mutex_enter(&dvl->dvl_mtx);
2459 	if (--dvl->dvl_nlock == 0)
2460 		dvl->dvl_holder = NULL;
2461 	cv_signal(&dvl->dvl_cv);
2462 	pmflock_debug(dev, __func__, __LINE__);
2463 	mutex_exit(&dvl->dvl_mtx);
2464 }
2465 
2466 device_lock_t
2467 device_getlock(device_t dev)
2468 {
2469 	return &dev->dv_lock;
2470 }
2471 
2472 void *
2473 device_pmf_bus_private(device_t dev)
2474 {
2475 	return dev->dv_bus_private;
2476 }
2477 
2478 bool
2479 device_pmf_bus_suspend(device_t dev, const pmf_qual_t *qual)
2480 {
2481 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) != 0)
2482 		return true;
2483 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) == 0 ||
2484 	    (dev->dv_flags & DVF_DRIVER_SUSPENDED) == 0)
2485 		return false;
2486 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_BUS &&
2487 	    dev->dv_bus_suspend != NULL &&
2488 	    !(*dev->dv_bus_suspend)(dev, qual))
2489 		return false;
2490 
2491 	dev->dv_flags |= DVF_BUS_SUSPENDED;
2492 	return true;
2493 }
2494 
2495 bool
2496 device_pmf_bus_resume(device_t dev, const pmf_qual_t *qual)
2497 {
2498 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) == 0)
2499 		return true;
2500 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_BUS &&
2501 	    dev->dv_bus_resume != NULL &&
2502 	    !(*dev->dv_bus_resume)(dev, qual))
2503 		return false;
2504 
2505 	dev->dv_flags &= ~DVF_BUS_SUSPENDED;
2506 	return true;
2507 }
2508 
2509 bool
2510 device_pmf_bus_shutdown(device_t dev, int how)
2511 {
2512 
2513 	if (*dev->dv_bus_shutdown != NULL &&
2514 	    !(*dev->dv_bus_shutdown)(dev, how))
2515 		return false;
2516 	return true;
2517 }
2518 
2519 void
2520 device_pmf_bus_register(device_t dev, void *priv,
2521     bool (*suspend)(device_t, const pmf_qual_t *),
2522     bool (*resume)(device_t, const pmf_qual_t *),
2523     bool (*shutdown)(device_t, int), void (*deregister)(device_t))
2524 {
2525 	dev->dv_bus_private = priv;
2526 	dev->dv_bus_resume = resume;
2527 	dev->dv_bus_suspend = suspend;
2528 	dev->dv_bus_shutdown = shutdown;
2529 	dev->dv_bus_deregister = deregister;
2530 }
2531 
2532 void
2533 device_pmf_bus_deregister(device_t dev)
2534 {
2535 	if (dev->dv_bus_deregister == NULL)
2536 		return;
2537 	(*dev->dv_bus_deregister)(dev);
2538 	dev->dv_bus_private = NULL;
2539 	dev->dv_bus_suspend = NULL;
2540 	dev->dv_bus_resume = NULL;
2541 	dev->dv_bus_deregister = NULL;
2542 }
2543 
2544 void *
2545 device_pmf_class_private(device_t dev)
2546 {
2547 	return dev->dv_class_private;
2548 }
2549 
2550 bool
2551 device_pmf_class_suspend(device_t dev, const pmf_qual_t *qual)
2552 {
2553 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) != 0)
2554 		return true;
2555 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_CLASS &&
2556 	    dev->dv_class_suspend != NULL &&
2557 	    !(*dev->dv_class_suspend)(dev, qual))
2558 		return false;
2559 
2560 	dev->dv_flags |= DVF_CLASS_SUSPENDED;
2561 	return true;
2562 }
2563 
2564 bool
2565 device_pmf_class_resume(device_t dev, const pmf_qual_t *qual)
2566 {
2567 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) == 0)
2568 		return true;
2569 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) != 0 ||
2570 	    (dev->dv_flags & DVF_DRIVER_SUSPENDED) != 0)
2571 		return false;
2572 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_CLASS &&
2573 	    dev->dv_class_resume != NULL &&
2574 	    !(*dev->dv_class_resume)(dev, qual))
2575 		return false;
2576 
2577 	dev->dv_flags &= ~DVF_CLASS_SUSPENDED;
2578 	return true;
2579 }
2580 
2581 void
2582 device_pmf_class_register(device_t dev, void *priv,
2583     bool (*suspend)(device_t, const pmf_qual_t *),
2584     bool (*resume)(device_t, const pmf_qual_t *),
2585     void (*deregister)(device_t))
2586 {
2587 	dev->dv_class_private = priv;
2588 	dev->dv_class_suspend = suspend;
2589 	dev->dv_class_resume = resume;
2590 	dev->dv_class_deregister = deregister;
2591 }
2592 
2593 void
2594 device_pmf_class_deregister(device_t dev)
2595 {
2596 	if (dev->dv_class_deregister == NULL)
2597 		return;
2598 	(*dev->dv_class_deregister)(dev);
2599 	dev->dv_class_private = NULL;
2600 	dev->dv_class_suspend = NULL;
2601 	dev->dv_class_resume = NULL;
2602 	dev->dv_class_deregister = NULL;
2603 }
2604 
2605 bool
2606 device_active(device_t dev, devactive_t type)
2607 {
2608 	size_t i;
2609 
2610 	if (dev->dv_activity_count == 0)
2611 		return false;
2612 
2613 	for (i = 0; i < dev->dv_activity_count; ++i) {
2614 		if (dev->dv_activity_handlers[i] == NULL)
2615 			break;
2616 		(*dev->dv_activity_handlers[i])(dev, type);
2617 	}
2618 
2619 	return true;
2620 }
2621 
2622 bool
2623 device_active_register(device_t dev, void (*handler)(device_t, devactive_t))
2624 {
2625 	void (**new_handlers)(device_t, devactive_t);
2626 	void (**old_handlers)(device_t, devactive_t);
2627 	size_t i, old_size, new_size;
2628 	int s;
2629 
2630 	old_handlers = dev->dv_activity_handlers;
2631 	old_size = dev->dv_activity_count;
2632 
2633 	for (i = 0; i < old_size; ++i) {
2634 		KASSERT(old_handlers[i] != handler);
2635 		if (old_handlers[i] == NULL) {
2636 			old_handlers[i] = handler;
2637 			return true;
2638 		}
2639 	}
2640 
2641 	new_size = old_size + 4;
2642 	new_handlers = kmem_alloc(sizeof(void *[new_size]), KM_SLEEP);
2643 
2644 	memcpy(new_handlers, old_handlers, sizeof(void *[old_size]));
2645 	new_handlers[old_size] = handler;
2646 	memset(new_handlers + old_size + 1, 0,
2647 	    sizeof(int [new_size - (old_size+1)]));
2648 
2649 	s = splhigh();
2650 	dev->dv_activity_count = new_size;
2651 	dev->dv_activity_handlers = new_handlers;
2652 	splx(s);
2653 
2654 	if (old_handlers != NULL)
2655 		kmem_free(old_handlers, sizeof(void * [old_size]));
2656 
2657 	return true;
2658 }
2659 
2660 void
2661 device_active_deregister(device_t dev, void (*handler)(device_t, devactive_t))
2662 {
2663 	void (**old_handlers)(device_t, devactive_t);
2664 	size_t i, old_size;
2665 	int s;
2666 
2667 	old_handlers = dev->dv_activity_handlers;
2668 	old_size = dev->dv_activity_count;
2669 
2670 	for (i = 0; i < old_size; ++i) {
2671 		if (old_handlers[i] == handler)
2672 			break;
2673 		if (old_handlers[i] == NULL)
2674 			return; /* XXX panic? */
2675 	}
2676 
2677 	if (i == old_size)
2678 		return; /* XXX panic? */
2679 
2680 	for (; i < old_size - 1; ++i) {
2681 		if ((old_handlers[i] = old_handlers[i + 1]) != NULL)
2682 			continue;
2683 
2684 		if (i == 0) {
2685 			s = splhigh();
2686 			dev->dv_activity_count = 0;
2687 			dev->dv_activity_handlers = NULL;
2688 			splx(s);
2689 			kmem_free(old_handlers, sizeof(void *[old_size]));
2690 		}
2691 		return;
2692 	}
2693 	old_handlers[i] = NULL;
2694 }
2695 
2696 /* Return true iff the device_t `dev' exists at generation `gen'. */
2697 static bool
2698 device_exists_at(device_t dv, devgen_t gen)
2699 {
2700 	return (dv->dv_del_gen == 0 || dv->dv_del_gen > gen) &&
2701 	    dv->dv_add_gen <= gen;
2702 }
2703 
2704 static bool
2705 deviter_visits(const deviter_t *di, device_t dv)
2706 {
2707 	return device_exists_at(dv, di->di_gen);
2708 }
2709 
2710 /*
2711  * Device Iteration
2712  *
2713  * deviter_t: a device iterator.  Holds state for a "walk" visiting
2714  *     each device_t's in the device tree.
2715  *
2716  * deviter_init(di, flags): initialize the device iterator `di'
2717  *     to "walk" the device tree.  deviter_next(di) will return
2718  *     the first device_t in the device tree, or NULL if there are
2719  *     no devices.
2720  *
2721  *     `flags' is one or more of DEVITER_F_RW, indicating that the
2722  *     caller intends to modify the device tree by calling
2723  *     config_detach(9) on devices in the order that the iterator
2724  *     returns them; DEVITER_F_ROOT_FIRST, asking for the devices
2725  *     nearest the "root" of the device tree to be returned, first;
2726  *     DEVITER_F_LEAVES_FIRST, asking for the devices furthest from
2727  *     the root of the device tree, first; and DEVITER_F_SHUTDOWN,
2728  *     indicating both that deviter_init() should not respect any
2729  *     locks on the device tree, and that deviter_next(di) may run
2730  *     in more than one LWP before the walk has finished.
2731  *
2732  *     Only one DEVITER_F_RW iterator may be in the device tree at
2733  *     once.
2734  *
2735  *     DEVITER_F_SHUTDOWN implies DEVITER_F_RW.
2736  *
2737  *     Results are undefined if the flags DEVITER_F_ROOT_FIRST and
2738  *     DEVITER_F_LEAVES_FIRST are used in combination.
2739  *
2740  * deviter_first(di, flags): initialize the device iterator `di'
2741  *     and return the first device_t in the device tree, or NULL
2742  *     if there are no devices.  The statement
2743  *
2744  *         dv = deviter_first(di);
2745  *
2746  *     is shorthand for
2747  *
2748  *         deviter_init(di);
2749  *         dv = deviter_next(di);
2750  *
2751  * deviter_next(di): return the next device_t in the device tree,
2752  *     or NULL if there are no more devices.  deviter_next(di)
2753  *     is undefined if `di' was not initialized with deviter_init() or
2754  *     deviter_first().
2755  *
2756  * deviter_release(di): stops iteration (subsequent calls to
2757  *     deviter_next() will return NULL), releases any locks and
2758  *     resources held by the device iterator.
2759  *
2760  * Device iteration does not return device_t's in any particular
2761  * order.  An iterator will never return the same device_t twice.
2762  * Device iteration is guaranteed to complete---i.e., if deviter_next(di)
2763  * is called repeatedly on the same `di', it will eventually return
2764  * NULL.  It is ok to attach/detach devices during device iteration.
2765  */
2766 void
2767 deviter_init(deviter_t *di, deviter_flags_t flags)
2768 {
2769 	device_t dv;
2770 	int s;
2771 
2772 	memset(di, 0, sizeof(*di));
2773 
2774 	s = config_alldevs_lock();
2775 	if ((flags & DEVITER_F_SHUTDOWN) != 0)
2776 		flags |= DEVITER_F_RW;
2777 
2778 	if ((flags & DEVITER_F_RW) != 0)
2779 		alldevs_nwrite++;
2780 	else
2781 		alldevs_nread++;
2782 	di->di_gen = alldevs_gen++;
2783 	config_alldevs_unlock(s);
2784 
2785 	di->di_flags = flags;
2786 
2787 	switch (di->di_flags & (DEVITER_F_LEAVES_FIRST|DEVITER_F_ROOT_FIRST)) {
2788 	case DEVITER_F_LEAVES_FIRST:
2789 		TAILQ_FOREACH(dv, &alldevs, dv_list) {
2790 			if (!deviter_visits(di, dv))
2791 				continue;
2792 			di->di_curdepth = MAX(di->di_curdepth, dv->dv_depth);
2793 		}
2794 		break;
2795 	case DEVITER_F_ROOT_FIRST:
2796 		TAILQ_FOREACH(dv, &alldevs, dv_list) {
2797 			if (!deviter_visits(di, dv))
2798 				continue;
2799 			di->di_maxdepth = MAX(di->di_maxdepth, dv->dv_depth);
2800 		}
2801 		break;
2802 	default:
2803 		break;
2804 	}
2805 
2806 	deviter_reinit(di);
2807 }
2808 
2809 static void
2810 deviter_reinit(deviter_t *di)
2811 {
2812 	if ((di->di_flags & DEVITER_F_RW) != 0)
2813 		di->di_prev = TAILQ_LAST(&alldevs, devicelist);
2814 	else
2815 		di->di_prev = TAILQ_FIRST(&alldevs);
2816 }
2817 
2818 device_t
2819 deviter_first(deviter_t *di, deviter_flags_t flags)
2820 {
2821 	deviter_init(di, flags);
2822 	return deviter_next(di);
2823 }
2824 
2825 static device_t
2826 deviter_next2(deviter_t *di)
2827 {
2828 	device_t dv;
2829 
2830 	dv = di->di_prev;
2831 
2832 	if (dv == NULL)
2833 		return NULL;
2834 
2835 	if ((di->di_flags & DEVITER_F_RW) != 0)
2836 		di->di_prev = TAILQ_PREV(dv, devicelist, dv_list);
2837 	else
2838 		di->di_prev = TAILQ_NEXT(dv, dv_list);
2839 
2840 	return dv;
2841 }
2842 
2843 static device_t
2844 deviter_next1(deviter_t *di)
2845 {
2846 	device_t dv;
2847 
2848 	do {
2849 		dv = deviter_next2(di);
2850 	} while (dv != NULL && !deviter_visits(di, dv));
2851 
2852 	return dv;
2853 }
2854 
2855 device_t
2856 deviter_next(deviter_t *di)
2857 {
2858 	device_t dv = NULL;
2859 
2860 	switch (di->di_flags & (DEVITER_F_LEAVES_FIRST|DEVITER_F_ROOT_FIRST)) {
2861 	case 0:
2862 		return deviter_next1(di);
2863 	case DEVITER_F_LEAVES_FIRST:
2864 		while (di->di_curdepth >= 0) {
2865 			if ((dv = deviter_next1(di)) == NULL) {
2866 				di->di_curdepth--;
2867 				deviter_reinit(di);
2868 			} else if (dv->dv_depth == di->di_curdepth)
2869 				break;
2870 		}
2871 		return dv;
2872 	case DEVITER_F_ROOT_FIRST:
2873 		while (di->di_curdepth <= di->di_maxdepth) {
2874 			if ((dv = deviter_next1(di)) == NULL) {
2875 				di->di_curdepth++;
2876 				deviter_reinit(di);
2877 			} else if (dv->dv_depth == di->di_curdepth)
2878 				break;
2879 		}
2880 		return dv;
2881 	default:
2882 		return NULL;
2883 	}
2884 }
2885 
2886 void
2887 deviter_release(deviter_t *di)
2888 {
2889 	bool rw = (di->di_flags & DEVITER_F_RW) != 0;
2890 	int s;
2891 
2892 	s = config_alldevs_lock();
2893 	if (rw)
2894 		--alldevs_nwrite;
2895 	else
2896 		--alldevs_nread;
2897 	/* XXX wake a garbage-collection thread */
2898 	config_alldevs_unlock(s);
2899 }
2900 
2901 const char *
2902 cfdata_ifattr(const struct cfdata *cf)
2903 {
2904 	return cf->cf_pspec->cfp_iattr;
2905 }
2906 
2907 bool
2908 ifattr_match(const char *snull, const char *t)
2909 {
2910 	return (snull == NULL) || strcmp(snull, t) == 0;
2911 }
2912 
2913 void
2914 null_childdetached(device_t self, device_t child)
2915 {
2916 	/* do nothing */
2917 }
2918 
2919 static void
2920 sysctl_detach_setup(struct sysctllog **clog)
2921 {
2922 
2923 	sysctl_createv(clog, 0, NULL, NULL,
2924 		CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
2925 		CTLTYPE_BOOL, "detachall",
2926 		SYSCTL_DESCR("Detach all devices at shutdown"),
2927 		NULL, 0, &detachall, 0,
2928 		CTL_KERN, CTL_CREATE, CTL_EOL);
2929 }
2930