xref: /netbsd-src/sys/kern/subr_autoconf.c (revision 7d62b00eb9ad855ffcd7da46b41e23feb5476fac)
1 /* $NetBSD: subr_autoconf.c,v 1.307 2023/02/22 17:00:16 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 1.307 2023/02/22 17:00:16 riastradh Exp $");
81 
82 #ifdef _KERNEL_OPT
83 #include "opt_ddb.h"
84 #include "drvctl.h"
85 #endif
86 
87 #include <sys/param.h>
88 #include <sys/device.h>
89 #include <sys/device_impl.h>
90 #include <sys/disklabel.h>
91 #include <sys/conf.h>
92 #include <sys/kauth.h>
93 #include <sys/kmem.h>
94 #include <sys/systm.h>
95 #include <sys/kernel.h>
96 #include <sys/errno.h>
97 #include <sys/proc.h>
98 #include <sys/reboot.h>
99 #include <sys/kthread.h>
100 #include <sys/buf.h>
101 #include <sys/dirent.h>
102 #include <sys/mount.h>
103 #include <sys/namei.h>
104 #include <sys/unistd.h>
105 #include <sys/fcntl.h>
106 #include <sys/lockf.h>
107 #include <sys/callout.h>
108 #include <sys/devmon.h>
109 #include <sys/cpu.h>
110 #include <sys/sysctl.h>
111 #include <sys/stdarg.h>
112 #include <sys/localcount.h>
113 
114 #include <sys/disk.h>
115 
116 #include <sys/rndsource.h>
117 
118 #include <machine/limits.h>
119 
120 /*
121  * Autoconfiguration subroutines.
122  */
123 
124 /*
125  * Device autoconfiguration timings are mixed into the entropy pool.
126  */
127 static krndsource_t rnd_autoconf_source;
128 
129 /*
130  * ioconf.c exports exactly two names: cfdata and cfroots.  All system
131  * devices and drivers are found via these tables.
132  */
133 extern struct cfdata cfdata[];
134 extern const short cfroots[];
135 
136 /*
137  * List of all cfdriver structures.  We use this to detect duplicates
138  * when other cfdrivers are loaded.
139  */
140 struct cfdriverlist allcfdrivers = LIST_HEAD_INITIALIZER(&allcfdrivers);
141 extern struct cfdriver * const cfdriver_list_initial[];
142 
143 /*
144  * Initial list of cfattach's.
145  */
146 extern const struct cfattachinit cfattachinit[];
147 
148 /*
149  * List of cfdata tables.  We always have one such list -- the one
150  * built statically when the kernel was configured.
151  */
152 struct cftablelist allcftables = TAILQ_HEAD_INITIALIZER(allcftables);
153 static struct cftable initcftable;
154 
155 #define	ROOT ((device_t)NULL)
156 
157 struct matchinfo {
158 	cfsubmatch_t fn;
159 	device_t parent;
160 	const int *locs;
161 	void	*aux;
162 	struct	cfdata *match;
163 	int	pri;
164 };
165 
166 struct alldevs_foray {
167 	int			af_s;
168 	struct devicelist	af_garbage;
169 };
170 
171 /*
172  * Internal version of the cfargs structure; all versions are
173  * canonicalized to this.
174  */
175 struct cfargs_internal {
176 	union {
177 		cfsubmatch_t	submatch;/* submatch function (direct config) */
178 		cfsearch_t	search;	 /* search function (indirect config) */
179 	};
180 	const char *	iattr;		/* interface attribute */
181 	const int *	locators;	/* locators array */
182 	devhandle_t	devhandle;	/* devhandle_t (by value) */
183 };
184 
185 static char *number(char *, int);
186 static void mapply(struct matchinfo *, cfdata_t);
187 static void config_devdelete(device_t);
188 static void config_devunlink(device_t, struct devicelist *);
189 static void config_makeroom(int, struct cfdriver *);
190 static void config_devlink(device_t);
191 static void config_alldevs_enter(struct alldevs_foray *);
192 static void config_alldevs_exit(struct alldevs_foray *);
193 static void config_add_attrib_dict(device_t);
194 static device_t	config_attach_internal(device_t, cfdata_t, void *,
195 		    cfprint_t, const struct cfargs_internal *);
196 
197 static void config_collect_garbage(struct devicelist *);
198 static void config_dump_garbage(struct devicelist *);
199 
200 static void pmflock_debug(device_t, const char *, int);
201 
202 static device_t deviter_next1(deviter_t *);
203 static void deviter_reinit(deviter_t *);
204 
205 struct deferred_config {
206 	TAILQ_ENTRY(deferred_config) dc_queue;
207 	device_t dc_dev;
208 	void (*dc_func)(device_t);
209 };
210 
211 TAILQ_HEAD(deferred_config_head, deferred_config);
212 
213 static struct deferred_config_head deferred_config_queue =
214 	TAILQ_HEAD_INITIALIZER(deferred_config_queue);
215 static struct deferred_config_head interrupt_config_queue =
216 	TAILQ_HEAD_INITIALIZER(interrupt_config_queue);
217 static int interrupt_config_threads = 8;
218 static struct deferred_config_head mountroot_config_queue =
219 	TAILQ_HEAD_INITIALIZER(mountroot_config_queue);
220 static int mountroot_config_threads = 2;
221 static lwp_t **mountroot_config_lwpids;
222 static size_t mountroot_config_lwpids_size;
223 bool root_is_mounted = false;
224 
225 static void config_process_deferred(struct deferred_config_head *, device_t);
226 
227 /* Hooks to finalize configuration once all real devices have been found. */
228 struct finalize_hook {
229 	TAILQ_ENTRY(finalize_hook) f_list;
230 	int (*f_func)(device_t);
231 	device_t f_dev;
232 };
233 static TAILQ_HEAD(, finalize_hook) config_finalize_list =
234 	TAILQ_HEAD_INITIALIZER(config_finalize_list);
235 static int config_finalize_done;
236 
237 /* list of all devices */
238 static struct devicelist alldevs = TAILQ_HEAD_INITIALIZER(alldevs);
239 static kmutex_t alldevs_lock __cacheline_aligned;
240 static devgen_t alldevs_gen = 1;
241 static int alldevs_nread = 0;
242 static int alldevs_nwrite = 0;
243 static bool alldevs_garbage = false;
244 
245 static struct devicelist config_pending =
246     TAILQ_HEAD_INITIALIZER(config_pending);
247 static kmutex_t config_misc_lock;
248 static kcondvar_t config_misc_cv;
249 
250 static bool detachall = false;
251 
252 #define	STREQ(s1, s2)			\
253 	(*(s1) == *(s2) && strcmp((s1), (s2)) == 0)
254 
255 static bool config_initialized = false;	/* config_init() has been called. */
256 
257 static int config_do_twiddle;
258 static callout_t config_twiddle_ch;
259 
260 static void sysctl_detach_setup(struct sysctllog **);
261 
262 int no_devmon_insert(const char *, prop_dictionary_t);
263 int (*devmon_insert_vec)(const char *, prop_dictionary_t) = no_devmon_insert;
264 
265 typedef int (*cfdriver_fn)(struct cfdriver *);
266 static int
267 frob_cfdrivervec(struct cfdriver * const *cfdriverv,
268 	cfdriver_fn drv_do, cfdriver_fn drv_undo,
269 	const char *style, bool dopanic)
270 {
271 	void (*pr)(const char *, ...) __printflike(1, 2) =
272 	    dopanic ? panic : printf;
273 	int i, error = 0, e2 __diagused;
274 
275 	for (i = 0; cfdriverv[i] != NULL; i++) {
276 		if ((error = drv_do(cfdriverv[i])) != 0) {
277 			pr("configure: `%s' driver %s failed: %d",
278 			    cfdriverv[i]->cd_name, style, error);
279 			goto bad;
280 		}
281 	}
282 
283 	KASSERT(error == 0);
284 	return 0;
285 
286  bad:
287 	printf("\n");
288 	for (i--; i >= 0; i--) {
289 		e2 = drv_undo(cfdriverv[i]);
290 		KASSERT(e2 == 0);
291 	}
292 
293 	return error;
294 }
295 
296 typedef int (*cfattach_fn)(const char *, struct cfattach *);
297 static int
298 frob_cfattachvec(const struct cfattachinit *cfattachv,
299 	cfattach_fn att_do, cfattach_fn att_undo,
300 	const char *style, bool dopanic)
301 {
302 	const struct cfattachinit *cfai = NULL;
303 	void (*pr)(const char *, ...) __printflike(1, 2) =
304 	    dopanic ? panic : printf;
305 	int j = 0, error = 0, e2 __diagused;
306 
307 	for (cfai = &cfattachv[0]; cfai->cfai_name != NULL; cfai++) {
308 		for (j = 0; cfai->cfai_list[j] != NULL; j++) {
309 			if ((error = att_do(cfai->cfai_name,
310 			    cfai->cfai_list[j])) != 0) {
311 				pr("configure: attachment `%s' "
312 				    "of `%s' driver %s failed: %d",
313 				    cfai->cfai_list[j]->ca_name,
314 				    cfai->cfai_name, style, error);
315 				goto bad;
316 			}
317 		}
318 	}
319 
320 	KASSERT(error == 0);
321 	return 0;
322 
323  bad:
324 	/*
325 	 * Rollback in reverse order.  dunno if super-important, but
326 	 * do that anyway.  Although the code looks a little like
327 	 * someone did a little integration (in the math sense).
328 	 */
329 	printf("\n");
330 	if (cfai) {
331 		bool last;
332 
333 		for (last = false; last == false; ) {
334 			if (cfai == &cfattachv[0])
335 				last = true;
336 			for (j--; j >= 0; j--) {
337 				e2 = att_undo(cfai->cfai_name,
338 				    cfai->cfai_list[j]);
339 				KASSERT(e2 == 0);
340 			}
341 			if (!last) {
342 				cfai--;
343 				for (j = 0; cfai->cfai_list[j] != NULL; j++)
344 					;
345 			}
346 		}
347 	}
348 
349 	return error;
350 }
351 
352 /*
353  * Initialize the autoconfiguration data structures.  Normally this
354  * is done by configure(), but some platforms need to do this very
355  * early (to e.g. initialize the console).
356  */
357 void
358 config_init(void)
359 {
360 
361 	KASSERT(config_initialized == false);
362 
363 	mutex_init(&alldevs_lock, MUTEX_DEFAULT, IPL_VM);
364 
365 	mutex_init(&config_misc_lock, MUTEX_DEFAULT, IPL_NONE);
366 	cv_init(&config_misc_cv, "cfgmisc");
367 
368 	callout_init(&config_twiddle_ch, CALLOUT_MPSAFE);
369 
370 	frob_cfdrivervec(cfdriver_list_initial,
371 	    config_cfdriver_attach, NULL, "bootstrap", true);
372 	frob_cfattachvec(cfattachinit,
373 	    config_cfattach_attach, NULL, "bootstrap", true);
374 
375 	initcftable.ct_cfdata = cfdata;
376 	TAILQ_INSERT_TAIL(&allcftables, &initcftable, ct_list);
377 
378 	rnd_attach_source(&rnd_autoconf_source, "autoconf", RND_TYPE_UNKNOWN,
379 	    RND_FLAG_COLLECT_TIME);
380 
381 	config_initialized = true;
382 }
383 
384 /*
385  * Init or fini drivers and attachments.  Either all or none
386  * are processed (via rollback).  It would be nice if this were
387  * atomic to outside consumers, but with the current state of
388  * locking ...
389  */
390 int
391 config_init_component(struct cfdriver * const *cfdriverv,
392 	const struct cfattachinit *cfattachv, struct cfdata *cfdatav)
393 {
394 	int error;
395 
396 	KERNEL_LOCK(1, NULL);
397 
398 	if ((error = frob_cfdrivervec(cfdriverv,
399 	    config_cfdriver_attach, config_cfdriver_detach, "init", false))!= 0)
400 		goto out;
401 	if ((error = frob_cfattachvec(cfattachv,
402 	    config_cfattach_attach, config_cfattach_detach,
403 	    "init", false)) != 0) {
404 		frob_cfdrivervec(cfdriverv,
405 	            config_cfdriver_detach, NULL, "init rollback", true);
406 		goto out;
407 	}
408 	if ((error = config_cfdata_attach(cfdatav, 1)) != 0) {
409 		frob_cfattachvec(cfattachv,
410 		    config_cfattach_detach, NULL, "init rollback", true);
411 		frob_cfdrivervec(cfdriverv,
412 	            config_cfdriver_detach, NULL, "init rollback", true);
413 		goto out;
414 	}
415 
416 	/* Success!  */
417 	error = 0;
418 
419 out:	KERNEL_UNLOCK_ONE(NULL);
420 	return error;
421 }
422 
423 int
424 config_fini_component(struct cfdriver * const *cfdriverv,
425 	const struct cfattachinit *cfattachv, struct cfdata *cfdatav)
426 {
427 	int error;
428 
429 	KERNEL_LOCK(1, NULL);
430 
431 	if ((error = config_cfdata_detach(cfdatav)) != 0)
432 		goto out;
433 	if ((error = frob_cfattachvec(cfattachv,
434 	    config_cfattach_detach, config_cfattach_attach,
435 	    "fini", false)) != 0) {
436 		if (config_cfdata_attach(cfdatav, 0) != 0)
437 			panic("config_cfdata fini rollback failed");
438 		goto out;
439 	}
440 	if ((error = frob_cfdrivervec(cfdriverv,
441 	    config_cfdriver_detach, config_cfdriver_attach,
442 	    "fini", false)) != 0) {
443 		frob_cfattachvec(cfattachv,
444 	            config_cfattach_attach, NULL, "fini rollback", true);
445 		if (config_cfdata_attach(cfdatav, 0) != 0)
446 			panic("config_cfdata fini rollback failed");
447 		goto out;
448 	}
449 
450 	/* Success!  */
451 	error = 0;
452 
453 out:	KERNEL_UNLOCK_ONE(NULL);
454 	return error;
455 }
456 
457 void
458 config_init_mi(void)
459 {
460 
461 	if (!config_initialized)
462 		config_init();
463 
464 	sysctl_detach_setup(NULL);
465 }
466 
467 void
468 config_deferred(device_t dev)
469 {
470 
471 	KASSERT(KERNEL_LOCKED_P());
472 
473 	config_process_deferred(&deferred_config_queue, dev);
474 	config_process_deferred(&interrupt_config_queue, dev);
475 	config_process_deferred(&mountroot_config_queue, dev);
476 }
477 
478 static void
479 config_interrupts_thread(void *cookie)
480 {
481 	struct deferred_config *dc;
482 	device_t dev;
483 
484 	mutex_enter(&config_misc_lock);
485 	while ((dc = TAILQ_FIRST(&interrupt_config_queue)) != NULL) {
486 		TAILQ_REMOVE(&interrupt_config_queue, dc, dc_queue);
487 		mutex_exit(&config_misc_lock);
488 
489 		dev = dc->dc_dev;
490 		(*dc->dc_func)(dev);
491 		if (!device_pmf_is_registered(dev))
492 			aprint_debug_dev(dev,
493 			    "WARNING: power management not supported\n");
494 		config_pending_decr(dev);
495 		kmem_free(dc, sizeof(*dc));
496 
497 		mutex_enter(&config_misc_lock);
498 	}
499 	mutex_exit(&config_misc_lock);
500 
501 	kthread_exit(0);
502 }
503 
504 void
505 config_create_interruptthreads(void)
506 {
507 	int i;
508 
509 	for (i = 0; i < interrupt_config_threads; i++) {
510 		(void)kthread_create(PRI_NONE, 0/*XXXSMP */, NULL,
511 		    config_interrupts_thread, NULL, NULL, "configintr");
512 	}
513 }
514 
515 static void
516 config_mountroot_thread(void *cookie)
517 {
518 	struct deferred_config *dc;
519 
520 	mutex_enter(&config_misc_lock);
521 	while ((dc = TAILQ_FIRST(&mountroot_config_queue)) != NULL) {
522 		TAILQ_REMOVE(&mountroot_config_queue, dc, dc_queue);
523 		mutex_exit(&config_misc_lock);
524 
525 		(*dc->dc_func)(dc->dc_dev);
526 		kmem_free(dc, sizeof(*dc));
527 
528 		mutex_enter(&config_misc_lock);
529 	}
530 	mutex_exit(&config_misc_lock);
531 
532 	kthread_exit(0);
533 }
534 
535 void
536 config_create_mountrootthreads(void)
537 {
538 	int i;
539 
540 	if (!root_is_mounted)
541 		root_is_mounted = true;
542 
543 	mountroot_config_lwpids_size = sizeof(mountroot_config_lwpids) *
544 				       mountroot_config_threads;
545 	mountroot_config_lwpids = kmem_alloc(mountroot_config_lwpids_size,
546 					     KM_NOSLEEP);
547 	KASSERT(mountroot_config_lwpids);
548 	for (i = 0; i < mountroot_config_threads; i++) {
549 		mountroot_config_lwpids[i] = 0;
550 		(void)kthread_create(PRI_NONE, KTHREAD_MUSTJOIN/* XXXSMP */,
551 				     NULL, config_mountroot_thread, NULL,
552 				     &mountroot_config_lwpids[i],
553 				     "configroot");
554 	}
555 }
556 
557 void
558 config_finalize_mountroot(void)
559 {
560 	int i, error;
561 
562 	for (i = 0; i < mountroot_config_threads; i++) {
563 		if (mountroot_config_lwpids[i] == 0)
564 			continue;
565 
566 		error = kthread_join(mountroot_config_lwpids[i]);
567 		if (error)
568 			printf("%s: thread %x joined with error %d\n",
569 			       __func__, i, error);
570 	}
571 	kmem_free(mountroot_config_lwpids, mountroot_config_lwpids_size);
572 }
573 
574 /*
575  * Announce device attach/detach to userland listeners.
576  */
577 
578 int
579 no_devmon_insert(const char *name, prop_dictionary_t p)
580 {
581 
582 	return ENODEV;
583 }
584 
585 static void
586 devmon_report_device(device_t dev, bool isattach)
587 {
588 	prop_dictionary_t ev, dict = device_properties(dev);
589 	const char *parent;
590 	const char *what;
591 	const char *where;
592 	device_t pdev = device_parent(dev);
593 
594 	/* If currently no drvctl device, just return */
595 	if (devmon_insert_vec == no_devmon_insert)
596 		return;
597 
598 	ev = prop_dictionary_create();
599 	if (ev == NULL)
600 		return;
601 
602 	what = (isattach ? "device-attach" : "device-detach");
603 	parent = (pdev == NULL ? "root" : device_xname(pdev));
604 	if (prop_dictionary_get_string(dict, "location", &where)) {
605 		prop_dictionary_set_string(ev, "location", where);
606 		aprint_debug("ev: %s %s at %s in [%s]\n",
607 		    what, device_xname(dev), parent, where);
608 	}
609 	if (!prop_dictionary_set_string(ev, "device", device_xname(dev)) ||
610 	    !prop_dictionary_set_string(ev, "parent", parent)) {
611 		prop_object_release(ev);
612 		return;
613 	}
614 
615 	if ((*devmon_insert_vec)(what, ev) != 0)
616 		prop_object_release(ev);
617 }
618 
619 /*
620  * Add a cfdriver to the system.
621  */
622 int
623 config_cfdriver_attach(struct cfdriver *cd)
624 {
625 	struct cfdriver *lcd;
626 
627 	/* Make sure this driver isn't already in the system. */
628 	LIST_FOREACH(lcd, &allcfdrivers, cd_list) {
629 		if (STREQ(lcd->cd_name, cd->cd_name))
630 			return EEXIST;
631 	}
632 
633 	LIST_INIT(&cd->cd_attach);
634 	LIST_INSERT_HEAD(&allcfdrivers, cd, cd_list);
635 
636 	return 0;
637 }
638 
639 /*
640  * Remove a cfdriver from the system.
641  */
642 int
643 config_cfdriver_detach(struct cfdriver *cd)
644 {
645 	struct alldevs_foray af;
646 	int i, rc = 0;
647 
648 	config_alldevs_enter(&af);
649 	/* Make sure there are no active instances. */
650 	for (i = 0; i < cd->cd_ndevs; i++) {
651 		if (cd->cd_devs[i] != NULL) {
652 			rc = EBUSY;
653 			break;
654 		}
655 	}
656 	config_alldevs_exit(&af);
657 
658 	if (rc != 0)
659 		return rc;
660 
661 	/* ...and no attachments loaded. */
662 	if (LIST_EMPTY(&cd->cd_attach) == 0)
663 		return EBUSY;
664 
665 	LIST_REMOVE(cd, cd_list);
666 
667 	KASSERT(cd->cd_devs == NULL);
668 
669 	return 0;
670 }
671 
672 /*
673  * Look up a cfdriver by name.
674  */
675 struct cfdriver *
676 config_cfdriver_lookup(const char *name)
677 {
678 	struct cfdriver *cd;
679 
680 	LIST_FOREACH(cd, &allcfdrivers, cd_list) {
681 		if (STREQ(cd->cd_name, name))
682 			return cd;
683 	}
684 
685 	return NULL;
686 }
687 
688 /*
689  * Add a cfattach to the specified driver.
690  */
691 int
692 config_cfattach_attach(const char *driver, struct cfattach *ca)
693 {
694 	struct cfattach *lca;
695 	struct cfdriver *cd;
696 
697 	cd = config_cfdriver_lookup(driver);
698 	if (cd == NULL)
699 		return ESRCH;
700 
701 	/* Make sure this attachment isn't already on this driver. */
702 	LIST_FOREACH(lca, &cd->cd_attach, ca_list) {
703 		if (STREQ(lca->ca_name, ca->ca_name))
704 			return EEXIST;
705 	}
706 
707 	LIST_INSERT_HEAD(&cd->cd_attach, ca, ca_list);
708 
709 	return 0;
710 }
711 
712 /*
713  * Remove a cfattach from the specified driver.
714  */
715 int
716 config_cfattach_detach(const char *driver, struct cfattach *ca)
717 {
718 	struct alldevs_foray af;
719 	struct cfdriver *cd;
720 	device_t dev;
721 	int i, rc = 0;
722 
723 	cd = config_cfdriver_lookup(driver);
724 	if (cd == NULL)
725 		return ESRCH;
726 
727 	config_alldevs_enter(&af);
728 	/* Make sure there are no active instances. */
729 	for (i = 0; i < cd->cd_ndevs; i++) {
730 		if ((dev = cd->cd_devs[i]) == NULL)
731 			continue;
732 		if (dev->dv_cfattach == ca) {
733 			rc = EBUSY;
734 			break;
735 		}
736 	}
737 	config_alldevs_exit(&af);
738 
739 	if (rc != 0)
740 		return rc;
741 
742 	LIST_REMOVE(ca, ca_list);
743 
744 	return 0;
745 }
746 
747 /*
748  * Look up a cfattach by name.
749  */
750 static struct cfattach *
751 config_cfattach_lookup_cd(struct cfdriver *cd, const char *atname)
752 {
753 	struct cfattach *ca;
754 
755 	LIST_FOREACH(ca, &cd->cd_attach, ca_list) {
756 		if (STREQ(ca->ca_name, atname))
757 			return ca;
758 	}
759 
760 	return NULL;
761 }
762 
763 /*
764  * Look up a cfattach by driver/attachment name.
765  */
766 struct cfattach *
767 config_cfattach_lookup(const char *name, const char *atname)
768 {
769 	struct cfdriver *cd;
770 
771 	cd = config_cfdriver_lookup(name);
772 	if (cd == NULL)
773 		return NULL;
774 
775 	return config_cfattach_lookup_cd(cd, atname);
776 }
777 
778 /*
779  * Apply the matching function and choose the best.  This is used
780  * a few times and we want to keep the code small.
781  */
782 static void
783 mapply(struct matchinfo *m, cfdata_t cf)
784 {
785 	int pri;
786 
787 	if (m->fn != NULL) {
788 		pri = (*m->fn)(m->parent, cf, m->locs, m->aux);
789 	} else {
790 		pri = config_match(m->parent, cf, m->aux);
791 	}
792 	if (pri > m->pri) {
793 		m->match = cf;
794 		m->pri = pri;
795 	}
796 }
797 
798 int
799 config_stdsubmatch(device_t parent, cfdata_t cf, const int *locs, void *aux)
800 {
801 	const struct cfiattrdata *ci;
802 	const struct cflocdesc *cl;
803 	int nlocs, i;
804 
805 	ci = cfiattr_lookup(cfdata_ifattr(cf), parent->dv_cfdriver);
806 	KASSERT(ci);
807 	nlocs = ci->ci_loclen;
808 	KASSERT(!nlocs || locs);
809 	for (i = 0; i < nlocs; i++) {
810 		cl = &ci->ci_locdesc[i];
811 		if (cl->cld_defaultstr != NULL &&
812 		    cf->cf_loc[i] == cl->cld_default)
813 			continue;
814 		if (cf->cf_loc[i] == locs[i])
815 			continue;
816 		return 0;
817 	}
818 
819 	return config_match(parent, cf, aux);
820 }
821 
822 /*
823  * Helper function: check whether the driver supports the interface attribute
824  * and return its descriptor structure.
825  */
826 static const struct cfiattrdata *
827 cfdriver_get_iattr(const struct cfdriver *cd, const char *ia)
828 {
829 	const struct cfiattrdata * const *cpp;
830 
831 	if (cd->cd_attrs == NULL)
832 		return 0;
833 
834 	for (cpp = cd->cd_attrs; *cpp; cpp++) {
835 		if (STREQ((*cpp)->ci_name, ia)) {
836 			/* Match. */
837 			return *cpp;
838 		}
839 	}
840 	return 0;
841 }
842 
843 static int __diagused
844 cfdriver_iattr_count(const struct cfdriver *cd)
845 {
846 	const struct cfiattrdata * const *cpp;
847 	int i;
848 
849 	if (cd->cd_attrs == NULL)
850 		return 0;
851 
852 	for (i = 0, cpp = cd->cd_attrs; *cpp; cpp++) {
853 		i++;
854 	}
855 	return i;
856 }
857 
858 /*
859  * Lookup an interface attribute description by name.
860  * If the driver is given, consider only its supported attributes.
861  */
862 const struct cfiattrdata *
863 cfiattr_lookup(const char *name, const struct cfdriver *cd)
864 {
865 	const struct cfdriver *d;
866 	const struct cfiattrdata *ia;
867 
868 	if (cd)
869 		return cfdriver_get_iattr(cd, name);
870 
871 	LIST_FOREACH(d, &allcfdrivers, cd_list) {
872 		ia = cfdriver_get_iattr(d, name);
873 		if (ia)
874 			return ia;
875 	}
876 	return 0;
877 }
878 
879 /*
880  * Determine if `parent' is a potential parent for a device spec based
881  * on `cfp'.
882  */
883 static int
884 cfparent_match(const device_t parent, const struct cfparent *cfp)
885 {
886 	struct cfdriver *pcd;
887 
888 	/* We don't match root nodes here. */
889 	if (cfp == NULL)
890 		return 0;
891 
892 	pcd = parent->dv_cfdriver;
893 	KASSERT(pcd != NULL);
894 
895 	/*
896 	 * First, ensure this parent has the correct interface
897 	 * attribute.
898 	 */
899 	if (!cfdriver_get_iattr(pcd, cfp->cfp_iattr))
900 		return 0;
901 
902 	/*
903 	 * If no specific parent device instance was specified (i.e.
904 	 * we're attaching to the attribute only), we're done!
905 	 */
906 	if (cfp->cfp_parent == NULL)
907 		return 1;
908 
909 	/*
910 	 * Check the parent device's name.
911 	 */
912 	if (STREQ(pcd->cd_name, cfp->cfp_parent) == 0)
913 		return 0;	/* not the same parent */
914 
915 	/*
916 	 * Make sure the unit number matches.
917 	 */
918 	if (cfp->cfp_unit == DVUNIT_ANY ||	/* wildcard */
919 	    cfp->cfp_unit == parent->dv_unit)
920 		return 1;
921 
922 	/* Unit numbers don't match. */
923 	return 0;
924 }
925 
926 /*
927  * Helper for config_cfdata_attach(): check all devices whether it could be
928  * parent any attachment in the config data table passed, and rescan.
929  */
930 static void
931 rescan_with_cfdata(const struct cfdata *cf)
932 {
933 	device_t d;
934 	const struct cfdata *cf1;
935 	deviter_t di;
936 
937 	KASSERT(KERNEL_LOCKED_P());
938 
939 	/*
940 	 * "alldevs" is likely longer than a modules's cfdata, so make it
941 	 * the outer loop.
942 	 */
943 	for (d = deviter_first(&di, 0); d != NULL; d = deviter_next(&di)) {
944 
945 		if (!(d->dv_cfattach->ca_rescan))
946 			continue;
947 
948 		for (cf1 = cf; cf1->cf_name; cf1++) {
949 
950 			if (!cfparent_match(d, cf1->cf_pspec))
951 				continue;
952 
953 			(*d->dv_cfattach->ca_rescan)(d,
954 				cfdata_ifattr(cf1), cf1->cf_loc);
955 
956 			config_deferred(d);
957 		}
958 	}
959 	deviter_release(&di);
960 }
961 
962 /*
963  * Attach a supplemental config data table and rescan potential
964  * parent devices if required.
965  */
966 int
967 config_cfdata_attach(cfdata_t cf, int scannow)
968 {
969 	struct cftable *ct;
970 
971 	KERNEL_LOCK(1, NULL);
972 
973 	ct = kmem_alloc(sizeof(*ct), KM_SLEEP);
974 	ct->ct_cfdata = cf;
975 	TAILQ_INSERT_TAIL(&allcftables, ct, ct_list);
976 
977 	if (scannow)
978 		rescan_with_cfdata(cf);
979 
980 	KERNEL_UNLOCK_ONE(NULL);
981 
982 	return 0;
983 }
984 
985 /*
986  * Helper for config_cfdata_detach: check whether a device is
987  * found through any attachment in the config data table.
988  */
989 static int
990 dev_in_cfdata(device_t d, cfdata_t cf)
991 {
992 	const struct cfdata *cf1;
993 
994 	for (cf1 = cf; cf1->cf_name; cf1++)
995 		if (d->dv_cfdata == cf1)
996 			return 1;
997 
998 	return 0;
999 }
1000 
1001 /*
1002  * Detach a supplemental config data table. Detach all devices found
1003  * through that table (and thus keeping references to it) before.
1004  */
1005 int
1006 config_cfdata_detach(cfdata_t cf)
1007 {
1008 	device_t d;
1009 	int error = 0;
1010 	struct cftable *ct;
1011 	deviter_t di;
1012 
1013 	KERNEL_LOCK(1, NULL);
1014 
1015 	for (d = deviter_first(&di, DEVITER_F_RW); d != NULL;
1016 	     d = deviter_next(&di)) {
1017 		if (!dev_in_cfdata(d, cf))
1018 			continue;
1019 		if ((error = config_detach(d, 0)) != 0)
1020 			break;
1021 	}
1022 	deviter_release(&di);
1023 	if (error) {
1024 		aprint_error_dev(d, "unable to detach instance\n");
1025 		goto out;
1026 	}
1027 
1028 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
1029 		if (ct->ct_cfdata == cf) {
1030 			TAILQ_REMOVE(&allcftables, ct, ct_list);
1031 			kmem_free(ct, sizeof(*ct));
1032 			error = 0;
1033 			goto out;
1034 		}
1035 	}
1036 
1037 	/* not found -- shouldn't happen */
1038 	error = EINVAL;
1039 
1040 out:	KERNEL_UNLOCK_ONE(NULL);
1041 	return error;
1042 }
1043 
1044 /*
1045  * Invoke the "match" routine for a cfdata entry on behalf of
1046  * an external caller, usually a direct config "submatch" routine.
1047  */
1048 int
1049 config_match(device_t parent, cfdata_t cf, void *aux)
1050 {
1051 	struct cfattach *ca;
1052 
1053 	KASSERT(KERNEL_LOCKED_P());
1054 
1055 	ca = config_cfattach_lookup(cf->cf_name, cf->cf_atname);
1056 	if (ca == NULL) {
1057 		/* No attachment for this entry, oh well. */
1058 		return 0;
1059 	}
1060 
1061 	return (*ca->ca_match)(parent, cf, aux);
1062 }
1063 
1064 /*
1065  * Invoke the "probe" routine for a cfdata entry on behalf of
1066  * an external caller, usually an indirect config "search" routine.
1067  */
1068 int
1069 config_probe(device_t parent, cfdata_t cf, void *aux)
1070 {
1071 	/*
1072 	 * This is currently a synonym for config_match(), but this
1073 	 * is an implementation detail; "match" and "probe" routines
1074 	 * have different behaviors.
1075 	 *
1076 	 * XXX config_probe() should return a bool, because there is
1077 	 * XXX no match score for probe -- it's either there or it's
1078 	 * XXX not, but some ports abuse the return value as a way
1079 	 * XXX to attach "critical" devices before "non-critical"
1080 	 * XXX devices.
1081 	 */
1082 	return config_match(parent, cf, aux);
1083 }
1084 
1085 static struct cfargs_internal *
1086 cfargs_canonicalize(const struct cfargs * const cfargs,
1087     struct cfargs_internal * const store)
1088 {
1089 	struct cfargs_internal *args = store;
1090 
1091 	memset(args, 0, sizeof(*args));
1092 
1093 	/* If none specified, are all-NULL pointers are good. */
1094 	if (cfargs == NULL) {
1095 		return args;
1096 	}
1097 
1098 	/*
1099 	 * Only one arguments version is recognized at this time.
1100 	 */
1101 	if (cfargs->cfargs_version != CFARGS_VERSION) {
1102 		panic("cfargs_canonicalize: unknown version %lu\n",
1103 		    (unsigned long)cfargs->cfargs_version);
1104 	}
1105 
1106 	/*
1107 	 * submatch and search are mutually-exclusive.
1108 	 */
1109 	if (cfargs->submatch != NULL && cfargs->search != NULL) {
1110 		panic("cfargs_canonicalize: submatch and search are "
1111 		      "mutually-exclusive");
1112 	}
1113 	if (cfargs->submatch != NULL) {
1114 		args->submatch = cfargs->submatch;
1115 	} else if (cfargs->search != NULL) {
1116 		args->search = cfargs->search;
1117 	}
1118 
1119 	args->iattr = cfargs->iattr;
1120 	args->locators = cfargs->locators;
1121 	args->devhandle = cfargs->devhandle;
1122 
1123 	return args;
1124 }
1125 
1126 /*
1127  * Iterate over all potential children of some device, calling the given
1128  * function (default being the child's match function) for each one.
1129  * Nonzero returns are matches; the highest value returned is considered
1130  * the best match.  Return the `found child' if we got a match, or NULL
1131  * otherwise.  The `aux' pointer is simply passed on through.
1132  *
1133  * Note that this function is designed so that it can be used to apply
1134  * an arbitrary function to all potential children (its return value
1135  * can be ignored).
1136  */
1137 static cfdata_t
1138 config_search_internal(device_t parent, void *aux,
1139     const struct cfargs_internal * const args)
1140 {
1141 	struct cftable *ct;
1142 	cfdata_t cf;
1143 	struct matchinfo m;
1144 
1145 	KASSERT(config_initialized);
1146 	KASSERTMSG((!args->iattr ||
1147 		cfdriver_get_iattr(parent->dv_cfdriver, args->iattr)),
1148 	    "%s searched for child at interface attribute %s,"
1149 	    " but device %s(4) has no such interface attribute in config(5)",
1150 	    device_xname(parent), args->iattr,
1151 	    parent->dv_cfdriver->cd_name);
1152 	KASSERTMSG((args->iattr ||
1153 		cfdriver_iattr_count(parent->dv_cfdriver) < 2),
1154 	    "%s searched for child without interface attribute,"
1155 	    " needed to disambiguate among the %d declared for in %s(4)"
1156 	    " in config(5)",
1157 	    device_xname(parent),
1158 	    cfdriver_iattr_count(parent->dv_cfdriver),
1159 	    parent->dv_cfdriver->cd_name);
1160 
1161 	m.fn = args->submatch;		/* N.B. union */
1162 	m.parent = parent;
1163 	m.locs = args->locators;
1164 	m.aux = aux;
1165 	m.match = NULL;
1166 	m.pri = 0;
1167 
1168 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
1169 		for (cf = ct->ct_cfdata; cf->cf_name; cf++) {
1170 
1171 			/* We don't match root nodes here. */
1172 			if (!cf->cf_pspec)
1173 				continue;
1174 
1175 			/*
1176 			 * Skip cf if no longer eligible, otherwise scan
1177 			 * through parents for one matching `parent', and
1178 			 * try match function.
1179 			 */
1180 			if (cf->cf_fstate == FSTATE_FOUND)
1181 				continue;
1182 			if (cf->cf_fstate == FSTATE_DNOTFOUND ||
1183 			    cf->cf_fstate == FSTATE_DSTAR)
1184 				continue;
1185 
1186 			/*
1187 			 * If an interface attribute was specified,
1188 			 * consider only children which attach to
1189 			 * that attribute.
1190 			 */
1191 			if (args->iattr != NULL &&
1192 			    !STREQ(args->iattr, cfdata_ifattr(cf)))
1193 				continue;
1194 
1195 			if (cfparent_match(parent, cf->cf_pspec))
1196 				mapply(&m, cf);
1197 		}
1198 	}
1199 	rnd_add_uint32(&rnd_autoconf_source, 0);
1200 	return m.match;
1201 }
1202 
1203 cfdata_t
1204 config_search(device_t parent, void *aux, const struct cfargs *cfargs)
1205 {
1206 	cfdata_t cf;
1207 	struct cfargs_internal store;
1208 
1209 	cf = config_search_internal(parent, aux,
1210 	    cfargs_canonicalize(cfargs, &store));
1211 
1212 	return cf;
1213 }
1214 
1215 /*
1216  * Find the given root device.
1217  * This is much like config_search, but there is no parent.
1218  * Don't bother with multiple cfdata tables; the root node
1219  * must always be in the initial table.
1220  */
1221 cfdata_t
1222 config_rootsearch(cfsubmatch_t fn, const char *rootname, void *aux)
1223 {
1224 	cfdata_t cf;
1225 	const short *p;
1226 	struct matchinfo m;
1227 
1228 	m.fn = fn;
1229 	m.parent = ROOT;
1230 	m.aux = aux;
1231 	m.match = NULL;
1232 	m.pri = 0;
1233 	m.locs = 0;
1234 	/*
1235 	 * Look at root entries for matching name.  We do not bother
1236 	 * with found-state here since only one root should ever be
1237 	 * searched (and it must be done first).
1238 	 */
1239 	for (p = cfroots; *p >= 0; p++) {
1240 		cf = &cfdata[*p];
1241 		if (strcmp(cf->cf_name, rootname) == 0)
1242 			mapply(&m, cf);
1243 	}
1244 	return m.match;
1245 }
1246 
1247 static const char * const msgs[] = {
1248 [QUIET]		=	"",
1249 [UNCONF]	=	" not configured\n",
1250 [UNSUPP]	=	" unsupported\n",
1251 };
1252 
1253 /*
1254  * The given `aux' argument describes a device that has been found
1255  * on the given parent, but not necessarily configured.  Locate the
1256  * configuration data for that device (using the submatch function
1257  * provided, or using candidates' cd_match configuration driver
1258  * functions) and attach it, and return its device_t.  If the device was
1259  * not configured, call the given `print' function and return NULL.
1260  */
1261 device_t
1262 config_found(device_t parent, void *aux, cfprint_t print,
1263     const struct cfargs * const cfargs)
1264 {
1265 	cfdata_t cf;
1266 	struct cfargs_internal store;
1267 	const struct cfargs_internal * const args =
1268 	    cfargs_canonicalize(cfargs, &store);
1269 
1270 	cf = config_search_internal(parent, aux, args);
1271 	if (cf != NULL) {
1272 		return config_attach_internal(parent, cf, aux, print, args);
1273 	}
1274 
1275 	if (print) {
1276 		if (config_do_twiddle && cold)
1277 			twiddle();
1278 
1279 		const int pret = (*print)(aux, device_xname(parent));
1280 		KASSERT(pret >= 0);
1281 		KASSERT(pret < __arraycount(msgs));
1282 		KASSERT(msgs[pret] != NULL);
1283 		aprint_normal("%s", msgs[pret]);
1284 	}
1285 
1286 	return NULL;
1287 }
1288 
1289 /*
1290  * As above, but for root devices.
1291  */
1292 device_t
1293 config_rootfound(const char *rootname, void *aux)
1294 {
1295 	cfdata_t cf;
1296 	device_t dev = NULL;
1297 
1298 	KERNEL_LOCK(1, NULL);
1299 	if ((cf = config_rootsearch(NULL, rootname, aux)) != NULL)
1300 		dev = config_attach(ROOT, cf, aux, NULL, CFARGS_NONE);
1301 	else
1302 		aprint_error("root device %s not configured\n", rootname);
1303 	KERNEL_UNLOCK_ONE(NULL);
1304 	return dev;
1305 }
1306 
1307 /* just like sprintf(buf, "%d") except that it works from the end */
1308 static char *
1309 number(char *ep, int n)
1310 {
1311 
1312 	*--ep = 0;
1313 	while (n >= 10) {
1314 		*--ep = (n % 10) + '0';
1315 		n /= 10;
1316 	}
1317 	*--ep = n + '0';
1318 	return ep;
1319 }
1320 
1321 /*
1322  * Expand the size of the cd_devs array if necessary.
1323  *
1324  * The caller must hold alldevs_lock. config_makeroom() may release and
1325  * re-acquire alldevs_lock, so callers should re-check conditions such
1326  * as alldevs_nwrite == 0 and alldevs_nread == 0 when config_makeroom()
1327  * returns.
1328  */
1329 static void
1330 config_makeroom(int n, struct cfdriver *cd)
1331 {
1332 	int ondevs, nndevs;
1333 	device_t *osp, *nsp;
1334 
1335 	KASSERT(mutex_owned(&alldevs_lock));
1336 	alldevs_nwrite++;
1337 
1338 	for (nndevs = MAX(4, cd->cd_ndevs); nndevs <= n; nndevs += nndevs)
1339 		;
1340 
1341 	while (n >= cd->cd_ndevs) {
1342 		/*
1343 		 * Need to expand the array.
1344 		 */
1345 		ondevs = cd->cd_ndevs;
1346 		osp = cd->cd_devs;
1347 
1348 		/*
1349 		 * Release alldevs_lock around allocation, which may
1350 		 * sleep.
1351 		 */
1352 		mutex_exit(&alldevs_lock);
1353 		nsp = kmem_alloc(sizeof(device_t) * nndevs, KM_SLEEP);
1354 		mutex_enter(&alldevs_lock);
1355 
1356 		/*
1357 		 * If another thread moved the array while we did
1358 		 * not hold alldevs_lock, try again.
1359 		 */
1360 		if (cd->cd_devs != osp) {
1361 			mutex_exit(&alldevs_lock);
1362 			kmem_free(nsp, sizeof(device_t) * nndevs);
1363 			mutex_enter(&alldevs_lock);
1364 			continue;
1365 		}
1366 
1367 		memset(nsp + ondevs, 0, sizeof(device_t) * (nndevs - ondevs));
1368 		if (ondevs != 0)
1369 			memcpy(nsp, cd->cd_devs, sizeof(device_t) * ondevs);
1370 
1371 		cd->cd_ndevs = nndevs;
1372 		cd->cd_devs = nsp;
1373 		if (ondevs != 0) {
1374 			mutex_exit(&alldevs_lock);
1375 			kmem_free(osp, sizeof(device_t) * ondevs);
1376 			mutex_enter(&alldevs_lock);
1377 		}
1378 	}
1379 	KASSERT(mutex_owned(&alldevs_lock));
1380 	alldevs_nwrite--;
1381 }
1382 
1383 /*
1384  * Put dev into the devices list.
1385  */
1386 static void
1387 config_devlink(device_t dev)
1388 {
1389 
1390 	mutex_enter(&alldevs_lock);
1391 
1392 	KASSERT(device_cfdriver(dev)->cd_devs[dev->dv_unit] == dev);
1393 
1394 	dev->dv_add_gen = alldevs_gen;
1395 	/* It is safe to add a device to the tail of the list while
1396 	 * readers and writers are in the list.
1397 	 */
1398 	TAILQ_INSERT_TAIL(&alldevs, dev, dv_list);
1399 	mutex_exit(&alldevs_lock);
1400 }
1401 
1402 static void
1403 config_devfree(device_t dev)
1404 {
1405 
1406 	KASSERT(dev->dv_flags & DVF_PRIV_ALLOC);
1407 	KASSERTMSG(dev->dv_pending == 0, "%d", dev->dv_pending);
1408 
1409 	if (dev->dv_cfattach->ca_devsize > 0)
1410 		kmem_free(dev->dv_private, dev->dv_cfattach->ca_devsize);
1411 	kmem_free(dev, sizeof(*dev));
1412 }
1413 
1414 /*
1415  * Caller must hold alldevs_lock.
1416  */
1417 static void
1418 config_devunlink(device_t dev, struct devicelist *garbage)
1419 {
1420 	struct device_garbage *dg = &dev->dv_garbage;
1421 	cfdriver_t cd = device_cfdriver(dev);
1422 	int i;
1423 
1424 	KASSERT(mutex_owned(&alldevs_lock));
1425 	KASSERTMSG(dev->dv_pending == 0, "%d", dev->dv_pending);
1426 
1427  	/* Unlink from device list.  Link to garbage list. */
1428 	TAILQ_REMOVE(&alldevs, dev, dv_list);
1429 	TAILQ_INSERT_TAIL(garbage, dev, dv_list);
1430 
1431 	/* Remove from cfdriver's array. */
1432 	cd->cd_devs[dev->dv_unit] = NULL;
1433 
1434 	/*
1435 	 * If the device now has no units in use, unlink its softc array.
1436 	 */
1437 	for (i = 0; i < cd->cd_ndevs; i++) {
1438 		if (cd->cd_devs[i] != NULL)
1439 			break;
1440 	}
1441 	/* Nothing found.  Unlink, now.  Deallocate, later. */
1442 	if (i == cd->cd_ndevs) {
1443 		dg->dg_ndevs = cd->cd_ndevs;
1444 		dg->dg_devs = cd->cd_devs;
1445 		cd->cd_devs = NULL;
1446 		cd->cd_ndevs = 0;
1447 	}
1448 }
1449 
1450 static void
1451 config_devdelete(device_t dev)
1452 {
1453 	struct device_garbage *dg = &dev->dv_garbage;
1454 	device_lock_t dvl = device_getlock(dev);
1455 
1456 	KASSERTMSG(dev->dv_pending == 0, "%d", dev->dv_pending);
1457 
1458 	if (dg->dg_devs != NULL)
1459 		kmem_free(dg->dg_devs, sizeof(device_t) * dg->dg_ndevs);
1460 
1461 	localcount_fini(dev->dv_localcount);
1462 	kmem_free(dev->dv_localcount, sizeof(*dev->dv_localcount));
1463 
1464 	cv_destroy(&dvl->dvl_cv);
1465 	mutex_destroy(&dvl->dvl_mtx);
1466 
1467 	KASSERT(dev->dv_properties != NULL);
1468 	prop_object_release(dev->dv_properties);
1469 
1470 	if (dev->dv_activity_handlers)
1471 		panic("%s with registered handlers", __func__);
1472 
1473 	if (dev->dv_locators) {
1474 		size_t amount = *--dev->dv_locators;
1475 		kmem_free(dev->dv_locators, amount);
1476 	}
1477 
1478 	config_devfree(dev);
1479 }
1480 
1481 static int
1482 config_unit_nextfree(cfdriver_t cd, cfdata_t cf)
1483 {
1484 	int unit = cf->cf_unit;
1485 
1486 	if (unit < 0)
1487 		return -1;
1488 	if (cf->cf_fstate == FSTATE_STAR) {
1489 		for (; unit < cd->cd_ndevs; unit++)
1490 			if (cd->cd_devs[unit] == NULL)
1491 				break;
1492 		/*
1493 		 * unit is now the unit of the first NULL device pointer,
1494 		 * or max(cd->cd_ndevs,cf->cf_unit).
1495 		 */
1496 	} else {
1497 		if (unit < cd->cd_ndevs && cd->cd_devs[unit] != NULL)
1498 			unit = -1;
1499 	}
1500 	return unit;
1501 }
1502 
1503 static int
1504 config_unit_alloc(device_t dev, cfdriver_t cd, cfdata_t cf)
1505 {
1506 	struct alldevs_foray af;
1507 	int unit;
1508 
1509 	config_alldevs_enter(&af);
1510 	for (;;) {
1511 		unit = config_unit_nextfree(cd, cf);
1512 		if (unit == -1)
1513 			break;
1514 		if (unit < cd->cd_ndevs) {
1515 			cd->cd_devs[unit] = dev;
1516 			dev->dv_unit = unit;
1517 			break;
1518 		}
1519 		config_makeroom(unit, cd);
1520 	}
1521 	config_alldevs_exit(&af);
1522 
1523 	return unit;
1524 }
1525 
1526 static device_t
1527 config_devalloc(const device_t parent, const cfdata_t cf,
1528     const struct cfargs_internal * const args)
1529 {
1530 	cfdriver_t cd;
1531 	cfattach_t ca;
1532 	size_t lname, lunit;
1533 	const char *xunit;
1534 	int myunit;
1535 	char num[10];
1536 	device_t dev;
1537 	void *dev_private;
1538 	const struct cfiattrdata *ia;
1539 	device_lock_t dvl;
1540 
1541 	cd = config_cfdriver_lookup(cf->cf_name);
1542 	if (cd == NULL)
1543 		return NULL;
1544 
1545 	ca = config_cfattach_lookup_cd(cd, cf->cf_atname);
1546 	if (ca == NULL)
1547 		return NULL;
1548 
1549 	/* get memory for all device vars */
1550 	KASSERT(ca->ca_flags & DVF_PRIV_ALLOC);
1551 	if (ca->ca_devsize > 0) {
1552 		dev_private = kmem_zalloc(ca->ca_devsize, KM_SLEEP);
1553 	} else {
1554 		dev_private = NULL;
1555 	}
1556 	dev = kmem_zalloc(sizeof(*dev), KM_SLEEP);
1557 
1558 	dev->dv_handle = args->devhandle;
1559 
1560 	dev->dv_class = cd->cd_class;
1561 	dev->dv_cfdata = cf;
1562 	dev->dv_cfdriver = cd;
1563 	dev->dv_cfattach = ca;
1564 	dev->dv_activity_count = 0;
1565 	dev->dv_activity_handlers = NULL;
1566 	dev->dv_private = dev_private;
1567 	dev->dv_flags = ca->ca_flags;	/* inherit flags from class */
1568 	dev->dv_attaching = curlwp;
1569 
1570 	myunit = config_unit_alloc(dev, cd, cf);
1571 	if (myunit == -1) {
1572 		config_devfree(dev);
1573 		return NULL;
1574 	}
1575 
1576 	/* compute length of name and decimal expansion of unit number */
1577 	lname = strlen(cd->cd_name);
1578 	xunit = number(&num[sizeof(num)], myunit);
1579 	lunit = &num[sizeof(num)] - xunit;
1580 	if (lname + lunit > sizeof(dev->dv_xname))
1581 		panic("config_devalloc: device name too long");
1582 
1583 	dvl = device_getlock(dev);
1584 
1585 	mutex_init(&dvl->dvl_mtx, MUTEX_DEFAULT, IPL_NONE);
1586 	cv_init(&dvl->dvl_cv, "pmfsusp");
1587 
1588 	memcpy(dev->dv_xname, cd->cd_name, lname);
1589 	memcpy(dev->dv_xname + lname, xunit, lunit);
1590 	dev->dv_parent = parent;
1591 	if (parent != NULL)
1592 		dev->dv_depth = parent->dv_depth + 1;
1593 	else
1594 		dev->dv_depth = 0;
1595 	dev->dv_flags |= DVF_ACTIVE;	/* always initially active */
1596 	if (args->locators) {
1597 		KASSERT(parent); /* no locators at root */
1598 		ia = cfiattr_lookup(cfdata_ifattr(cf), parent->dv_cfdriver);
1599 		dev->dv_locators =
1600 		    kmem_alloc(sizeof(int) * (ia->ci_loclen + 1), KM_SLEEP);
1601 		*dev->dv_locators++ = sizeof(int) * (ia->ci_loclen + 1);
1602 		memcpy(dev->dv_locators, args->locators,
1603 		    sizeof(int) * ia->ci_loclen);
1604 	}
1605 	dev->dv_properties = prop_dictionary_create();
1606 	KASSERT(dev->dv_properties != NULL);
1607 
1608 	prop_dictionary_set_string_nocopy(dev->dv_properties,
1609 	    "device-driver", dev->dv_cfdriver->cd_name);
1610 	prop_dictionary_set_uint16(dev->dv_properties,
1611 	    "device-unit", dev->dv_unit);
1612 	if (parent != NULL) {
1613 		prop_dictionary_set_string(dev->dv_properties,
1614 		    "device-parent", device_xname(parent));
1615 	}
1616 
1617 	dev->dv_localcount = kmem_zalloc(sizeof(*dev->dv_localcount),
1618 	    KM_SLEEP);
1619 	localcount_init(dev->dv_localcount);
1620 
1621 	if (dev->dv_cfdriver->cd_attrs != NULL)
1622 		config_add_attrib_dict(dev);
1623 
1624 	return dev;
1625 }
1626 
1627 /*
1628  * Create an array of device attach attributes and add it
1629  * to the device's dv_properties dictionary.
1630  *
1631  * <key>interface-attributes</key>
1632  * <array>
1633  *    <dict>
1634  *       <key>attribute-name</key>
1635  *       <string>foo</string>
1636  *       <key>locators</key>
1637  *       <array>
1638  *          <dict>
1639  *             <key>loc-name</key>
1640  *             <string>foo-loc1</string>
1641  *          </dict>
1642  *          <dict>
1643  *             <key>loc-name</key>
1644  *             <string>foo-loc2</string>
1645  *             <key>default</key>
1646  *             <string>foo-loc2-default</string>
1647  *          </dict>
1648  *          ...
1649  *       </array>
1650  *    </dict>
1651  *    ...
1652  * </array>
1653  */
1654 
1655 static void
1656 config_add_attrib_dict(device_t dev)
1657 {
1658 	int i, j;
1659 	const struct cfiattrdata *ci;
1660 	prop_dictionary_t attr_dict, loc_dict;
1661 	prop_array_t attr_array, loc_array;
1662 
1663 	if ((attr_array = prop_array_create()) == NULL)
1664 		return;
1665 
1666 	for (i = 0; ; i++) {
1667 		if ((ci = dev->dv_cfdriver->cd_attrs[i]) == NULL)
1668 			break;
1669 		if ((attr_dict = prop_dictionary_create()) == NULL)
1670 			break;
1671 		prop_dictionary_set_string_nocopy(attr_dict, "attribute-name",
1672 		    ci->ci_name);
1673 
1674 		/* Create an array of the locator names and defaults */
1675 
1676 		if (ci->ci_loclen != 0 &&
1677 		    (loc_array = prop_array_create()) != NULL) {
1678 			for (j = 0; j < ci->ci_loclen; j++) {
1679 				loc_dict = prop_dictionary_create();
1680 				if (loc_dict == NULL)
1681 					continue;
1682 				prop_dictionary_set_string_nocopy(loc_dict,
1683 				    "loc-name", ci->ci_locdesc[j].cld_name);
1684 				if (ci->ci_locdesc[j].cld_defaultstr != NULL)
1685 					prop_dictionary_set_string_nocopy(
1686 					    loc_dict, "default",
1687 					    ci->ci_locdesc[j].cld_defaultstr);
1688 				prop_array_set(loc_array, j, loc_dict);
1689 				prop_object_release(loc_dict);
1690 			}
1691 			prop_dictionary_set_and_rel(attr_dict, "locators",
1692 			    loc_array);
1693 		}
1694 		prop_array_add(attr_array, attr_dict);
1695 		prop_object_release(attr_dict);
1696 	}
1697 	if (i == 0)
1698 		prop_object_release(attr_array);
1699 	else
1700 		prop_dictionary_set_and_rel(dev->dv_properties,
1701 		    "interface-attributes", attr_array);
1702 
1703 	return;
1704 }
1705 
1706 /*
1707  * Attach a found device.
1708  */
1709 static device_t
1710 config_attach_internal(device_t parent, cfdata_t cf, void *aux, cfprint_t print,
1711     const struct cfargs_internal * const args)
1712 {
1713 	device_t dev;
1714 	struct cftable *ct;
1715 	const char *drvname;
1716 	bool deferred;
1717 
1718 	KASSERT(KERNEL_LOCKED_P());
1719 
1720 	dev = config_devalloc(parent, cf, args);
1721 	if (!dev)
1722 		panic("config_attach: allocation of device softc failed");
1723 
1724 	/* XXX redundant - see below? */
1725 	if (cf->cf_fstate != FSTATE_STAR) {
1726 		KASSERT(cf->cf_fstate == FSTATE_NOTFOUND);
1727 		cf->cf_fstate = FSTATE_FOUND;
1728 	}
1729 
1730 	config_devlink(dev);
1731 
1732 	if (config_do_twiddle && cold)
1733 		twiddle();
1734 	else
1735 		aprint_naive("Found ");
1736 	/*
1737 	 * We want the next two printfs for normal, verbose, and quiet,
1738 	 * but not silent (in which case, we're twiddling, instead).
1739 	 */
1740 	if (parent == ROOT) {
1741 		aprint_naive("%s (root)", device_xname(dev));
1742 		aprint_normal("%s (root)", device_xname(dev));
1743 	} else {
1744 		aprint_naive("%s at %s", device_xname(dev),
1745 		    device_xname(parent));
1746 		aprint_normal("%s at %s", device_xname(dev),
1747 		    device_xname(parent));
1748 		if (print)
1749 			(void) (*print)(aux, NULL);
1750 	}
1751 
1752 	/*
1753 	 * Before attaching, clobber any unfound devices that are
1754 	 * otherwise identical.
1755 	 * XXX code above is redundant?
1756 	 */
1757 	drvname = dev->dv_cfdriver->cd_name;
1758 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
1759 		for (cf = ct->ct_cfdata; cf->cf_name; cf++) {
1760 			if (STREQ(cf->cf_name, drvname) &&
1761 			    cf->cf_unit == dev->dv_unit) {
1762 				if (cf->cf_fstate == FSTATE_NOTFOUND)
1763 					cf->cf_fstate = FSTATE_FOUND;
1764 			}
1765 		}
1766 	}
1767 	device_register(dev, aux);
1768 
1769 	/* Let userland know */
1770 	devmon_report_device(dev, true);
1771 
1772 	/*
1773 	 * Prevent detach until the driver's attach function, and all
1774 	 * deferred actions, have finished.
1775 	 */
1776 	config_pending_incr(dev);
1777 
1778 	/* Call the driver's attach function.  */
1779 	(*dev->dv_cfattach->ca_attach)(parent, dev, aux);
1780 
1781 	/*
1782 	 * Allow other threads to acquire references to the device now
1783 	 * that the driver's attach function is done.
1784 	 */
1785 	mutex_enter(&config_misc_lock);
1786 	KASSERT(dev->dv_attaching == curlwp);
1787 	dev->dv_attaching = NULL;
1788 	cv_broadcast(&config_misc_cv);
1789 	mutex_exit(&config_misc_lock);
1790 
1791 	/*
1792 	 * Synchronous parts of attach are done.  Allow detach, unless
1793 	 * the driver's attach function scheduled deferred actions.
1794 	 */
1795 	config_pending_decr(dev);
1796 
1797 	mutex_enter(&config_misc_lock);
1798 	deferred = (dev->dv_pending != 0);
1799 	mutex_exit(&config_misc_lock);
1800 
1801 	if (!deferred && !device_pmf_is_registered(dev))
1802 		aprint_debug_dev(dev,
1803 		    "WARNING: power management not supported\n");
1804 
1805 	config_process_deferred(&deferred_config_queue, dev);
1806 
1807 	device_register_post_config(dev, aux);
1808 	rnd_add_uint32(&rnd_autoconf_source, 0);
1809 	return dev;
1810 }
1811 
1812 device_t
1813 config_attach(device_t parent, cfdata_t cf, void *aux, cfprint_t print,
1814     const struct cfargs *cfargs)
1815 {
1816 	struct cfargs_internal store;
1817 
1818 	KASSERT(KERNEL_LOCKED_P());
1819 
1820 	return config_attach_internal(parent, cf, aux, print,
1821 	    cfargs_canonicalize(cfargs, &store));
1822 }
1823 
1824 /*
1825  * As above, but for pseudo-devices.  Pseudo-devices attached in this
1826  * way are silently inserted into the device tree, and their children
1827  * attached.
1828  *
1829  * Note that because pseudo-devices are attached silently, any information
1830  * the attach routine wishes to print should be prefixed with the device
1831  * name by the attach routine.
1832  */
1833 device_t
1834 config_attach_pseudo(cfdata_t cf)
1835 {
1836 	device_t dev;
1837 
1838 	KERNEL_LOCK(1, NULL);
1839 
1840 	struct cfargs_internal args = { };
1841 	dev = config_devalloc(ROOT, cf, &args);
1842 	if (!dev)
1843 		goto out;
1844 
1845 	/* XXX mark busy in cfdata */
1846 
1847 	if (cf->cf_fstate != FSTATE_STAR) {
1848 		KASSERT(cf->cf_fstate == FSTATE_NOTFOUND);
1849 		cf->cf_fstate = FSTATE_FOUND;
1850 	}
1851 
1852 	config_devlink(dev);
1853 
1854 #if 0	/* XXXJRT not yet */
1855 	device_register(dev, NULL);	/* like a root node */
1856 #endif
1857 
1858 	/* Let userland know */
1859 	devmon_report_device(dev, true);
1860 
1861 	/*
1862 	 * Prevent detach until the driver's attach function, and all
1863 	 * deferred actions, have finished.
1864 	 */
1865 	config_pending_incr(dev);
1866 
1867 	/* Call the driver's attach function.  */
1868 	(*dev->dv_cfattach->ca_attach)(ROOT, dev, NULL);
1869 
1870 	/*
1871 	 * Allow other threads to acquire references to the device now
1872 	 * that the driver's attach function is done.
1873 	 */
1874 	mutex_enter(&config_misc_lock);
1875 	KASSERT(dev->dv_attaching == curlwp);
1876 	dev->dv_attaching = NULL;
1877 	cv_broadcast(&config_misc_cv);
1878 	mutex_exit(&config_misc_lock);
1879 
1880 	/*
1881 	 * Synchronous parts of attach are done.  Allow detach, unless
1882 	 * the driver's attach function scheduled deferred actions.
1883 	 */
1884 	config_pending_decr(dev);
1885 
1886 	config_process_deferred(&deferred_config_queue, dev);
1887 
1888 out:	KERNEL_UNLOCK_ONE(NULL);
1889 	return dev;
1890 }
1891 
1892 /*
1893  * Caller must hold alldevs_lock.
1894  */
1895 static void
1896 config_collect_garbage(struct devicelist *garbage)
1897 {
1898 	device_t dv;
1899 
1900 	KASSERT(!cpu_intr_p());
1901 	KASSERT(!cpu_softintr_p());
1902 	KASSERT(mutex_owned(&alldevs_lock));
1903 
1904 	while (alldevs_nwrite == 0 && alldevs_nread == 0 && alldevs_garbage) {
1905 		TAILQ_FOREACH(dv, &alldevs, dv_list) {
1906 			if (dv->dv_del_gen != 0)
1907 				break;
1908 		}
1909 		if (dv == NULL) {
1910 			alldevs_garbage = false;
1911 			break;
1912 		}
1913 		config_devunlink(dv, garbage);
1914 	}
1915 	KASSERT(mutex_owned(&alldevs_lock));
1916 }
1917 
1918 static void
1919 config_dump_garbage(struct devicelist *garbage)
1920 {
1921 	device_t dv;
1922 
1923 	while ((dv = TAILQ_FIRST(garbage)) != NULL) {
1924 		TAILQ_REMOVE(garbage, dv, dv_list);
1925 		config_devdelete(dv);
1926 	}
1927 }
1928 
1929 static int
1930 config_detach_enter(device_t dev)
1931 {
1932 	struct lwp *l __diagused;
1933 	int error = 0;
1934 
1935 	mutex_enter(&config_misc_lock);
1936 
1937 	/*
1938 	 * Wait until attach has fully completed, and until any
1939 	 * concurrent detach (e.g., drvctl racing with USB event
1940 	 * thread) has completed.
1941 	 *
1942 	 * Caller must hold alldevs_nread or alldevs_nwrite (e.g., via
1943 	 * deviter) to ensure the winner of the race doesn't free the
1944 	 * device leading the loser of the race into use-after-free.
1945 	 *
1946 	 * XXX Not all callers do this!
1947 	 */
1948 	while (dev->dv_pending || dev->dv_detaching) {
1949 		KASSERTMSG(dev->dv_detaching != curlwp,
1950 		    "recursively detaching %s", device_xname(dev));
1951 		error = cv_wait_sig(&config_misc_cv, &config_misc_lock);
1952 		if (error)
1953 			goto out;
1954 	}
1955 
1956 	/*
1957 	 * Attach has completed, and no other concurrent detach is
1958 	 * running.  Claim the device for detaching.  This will cause
1959 	 * all new attempts to acquire references to block.
1960 	 */
1961 	KASSERTMSG((l = dev->dv_attaching) == NULL,
1962 	    "lwp %ld [%s] @ %p attaching %s",
1963 	    (long)l->l_lid, (l->l_name ? l->l_name : l->l_proc->p_comm), l,
1964 	    device_xname(dev));
1965 	KASSERTMSG((l = dev->dv_detaching) == NULL,
1966 	    "lwp %ld [%s] @ %p detaching %s",
1967 	    (long)l->l_lid, (l->l_name ? l->l_name : l->l_proc->p_comm), l,
1968 	    device_xname(dev));
1969 	dev->dv_detaching = curlwp;
1970 
1971 out:	mutex_exit(&config_misc_lock);
1972 	return error;
1973 }
1974 
1975 static void
1976 config_detach_exit(device_t dev)
1977 {
1978 	struct lwp *l __diagused;
1979 
1980 	mutex_enter(&config_misc_lock);
1981 	KASSERTMSG(dev->dv_detaching != NULL, "not detaching %s",
1982 	    device_xname(dev));
1983 	KASSERTMSG((l = dev->dv_detaching) == curlwp,
1984 	    "lwp %ld [%s] @ %p detaching %s",
1985 	    (long)l->l_lid, (l->l_name ? l->l_name : l->l_proc->p_comm), l,
1986 	    device_xname(dev));
1987 	dev->dv_detaching = NULL;
1988 	cv_broadcast(&config_misc_cv);
1989 	mutex_exit(&config_misc_lock);
1990 }
1991 
1992 /*
1993  * Detach a device.  Optionally forced (e.g. because of hardware
1994  * removal) and quiet.  Returns zero if successful, non-zero
1995  * (an error code) otherwise.
1996  *
1997  * Note that this code wants to be run from a process context, so
1998  * that the detach can sleep to allow processes which have a device
1999  * open to run and unwind their stacks.
2000  */
2001 int
2002 config_detach(device_t dev, int flags)
2003 {
2004 	struct alldevs_foray af;
2005 	struct cftable *ct;
2006 	cfdata_t cf;
2007 	const struct cfattach *ca;
2008 	struct cfdriver *cd;
2009 	device_t d __diagused;
2010 	int rv = 0;
2011 
2012 	KERNEL_LOCK(1, NULL);
2013 
2014 	cf = dev->dv_cfdata;
2015 	KASSERTMSG((cf == NULL || cf->cf_fstate == FSTATE_FOUND ||
2016 		cf->cf_fstate == FSTATE_STAR),
2017 	    "config_detach: %s: bad device fstate: %d",
2018 	    device_xname(dev), cf ? cf->cf_fstate : -1);
2019 
2020 	cd = dev->dv_cfdriver;
2021 	KASSERT(cd != NULL);
2022 
2023 	ca = dev->dv_cfattach;
2024 	KASSERT(ca != NULL);
2025 
2026 	/*
2027 	 * Only one detach at a time, please -- and not until fully
2028 	 * attached.
2029 	 */
2030 	rv = config_detach_enter(dev);
2031 	if (rv) {
2032 		KERNEL_UNLOCK_ONE(NULL);
2033 		return rv;
2034 	}
2035 
2036 	mutex_enter(&alldevs_lock);
2037 	if (dev->dv_del_gen != 0) {
2038 		mutex_exit(&alldevs_lock);
2039 #ifdef DIAGNOSTIC
2040 		printf("%s: %s is already detached\n", __func__,
2041 		    device_xname(dev));
2042 #endif /* DIAGNOSTIC */
2043 		config_detach_exit(dev);
2044 		KERNEL_UNLOCK_ONE(NULL);
2045 		return ENOENT;
2046 	}
2047 	alldevs_nwrite++;
2048 	mutex_exit(&alldevs_lock);
2049 
2050 	/*
2051 	 * Call the driver's .ca_detach function, unless it has none or
2052 	 * we are skipping it because it's unforced shutdown time and
2053 	 * the driver didn't ask to detach on shutdown.
2054 	 */
2055 	if (!detachall &&
2056 	    (flags & (DETACH_SHUTDOWN|DETACH_FORCE)) == DETACH_SHUTDOWN &&
2057 	    (dev->dv_flags & DVF_DETACH_SHUTDOWN) == 0) {
2058 		rv = EOPNOTSUPP;
2059 	} else if (ca->ca_detach != NULL) {
2060 		rv = (*ca->ca_detach)(dev, flags);
2061 	} else
2062 		rv = EOPNOTSUPP;
2063 
2064 	KASSERTMSG(!dev->dv_detach_done, "%s detached twice, error=%d",
2065 	    device_xname(dev), rv);
2066 
2067 	/*
2068 	 * If it was not possible to detach the device, then we either
2069 	 * panic() (for the forced but failed case), or return an error.
2070 	 */
2071 	if (rv) {
2072 		/*
2073 		 * Detach failed -- likely EOPNOTSUPP or EBUSY.  Driver
2074 		 * must not have called config_detach_commit.
2075 		 */
2076 		KASSERTMSG(!dev->dv_detach_committed,
2077 		    "%s committed to detaching and then backed out, error=%d",
2078 		    device_xname(dev), rv);
2079 		if (flags & DETACH_FORCE) {
2080 			panic("config_detach: forced detach of %s failed (%d)",
2081 			    device_xname(dev), rv);
2082 		}
2083 		goto out;
2084 	}
2085 
2086 	/*
2087 	 * The device has now been successfully detached.
2088 	 */
2089 	dev->dv_detach_done = true;
2090 
2091 	/*
2092 	 * If .ca_detach didn't commit to detach, then do that for it.
2093 	 * This wakes any pending device_lookup_acquire calls so they
2094 	 * will fail.
2095 	 */
2096 	config_detach_commit(dev);
2097 
2098 	/*
2099 	 * If it was possible to detach the device, ensure that the
2100 	 * device is deactivated.
2101 	 */
2102 	dev->dv_flags &= ~DVF_ACTIVE; /* XXXSMP */
2103 
2104 	/*
2105 	 * Wait for all device_lookup_acquire references -- mostly, for
2106 	 * all attempts to open the device -- to drain.  It is the
2107 	 * responsibility of .ca_detach to ensure anything with open
2108 	 * references will be interrupted and release them promptly,
2109 	 * not block indefinitely.  All new attempts to acquire
2110 	 * references will fail, as config_detach_commit has arranged
2111 	 * by now.
2112 	 */
2113 	mutex_enter(&config_misc_lock);
2114 	localcount_drain(dev->dv_localcount,
2115 	    &config_misc_cv, &config_misc_lock);
2116 	mutex_exit(&config_misc_lock);
2117 
2118 	/* Let userland know */
2119 	devmon_report_device(dev, false);
2120 
2121 #ifdef DIAGNOSTIC
2122 	/*
2123 	 * Sanity: If you're successfully detached, you should have no
2124 	 * children.  (Note that because children must be attached
2125 	 * after parents, we only need to search the latter part of
2126 	 * the list.)
2127 	 */
2128 	mutex_enter(&alldevs_lock);
2129 	for (d = TAILQ_NEXT(dev, dv_list); d != NULL;
2130 	    d = TAILQ_NEXT(d, dv_list)) {
2131 		if (d->dv_parent == dev && d->dv_del_gen == 0) {
2132 			printf("config_detach: detached device %s"
2133 			    " has children %s\n", device_xname(dev),
2134 			    device_xname(d));
2135 			panic("config_detach");
2136 		}
2137 	}
2138 	mutex_exit(&alldevs_lock);
2139 #endif
2140 
2141 	/* notify the parent that the child is gone */
2142 	if (dev->dv_parent) {
2143 		device_t p = dev->dv_parent;
2144 		if (p->dv_cfattach->ca_childdetached)
2145 			(*p->dv_cfattach->ca_childdetached)(p, dev);
2146 	}
2147 
2148 	/*
2149 	 * Mark cfdata to show that the unit can be reused, if possible.
2150 	 */
2151 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
2152 		for (cf = ct->ct_cfdata; cf->cf_name; cf++) {
2153 			if (STREQ(cf->cf_name, cd->cd_name)) {
2154 				if (cf->cf_fstate == FSTATE_FOUND &&
2155 				    cf->cf_unit == dev->dv_unit)
2156 					cf->cf_fstate = FSTATE_NOTFOUND;
2157 			}
2158 		}
2159 	}
2160 
2161 	if (dev->dv_cfdata != NULL && (flags & DETACH_QUIET) == 0)
2162 		aprint_normal_dev(dev, "detached\n");
2163 
2164 out:
2165 	config_detach_exit(dev);
2166 
2167 	config_alldevs_enter(&af);
2168 	KASSERT(alldevs_nwrite != 0);
2169 	--alldevs_nwrite;
2170 	if (rv == 0 && dev->dv_del_gen == 0) {
2171 		if (alldevs_nwrite == 0 && alldevs_nread == 0)
2172 			config_devunlink(dev, &af.af_garbage);
2173 		else {
2174 			dev->dv_del_gen = alldevs_gen;
2175 			alldevs_garbage = true;
2176 		}
2177 	}
2178 	config_alldevs_exit(&af);
2179 
2180 	KERNEL_UNLOCK_ONE(NULL);
2181 
2182 	return rv;
2183 }
2184 
2185 /*
2186  * config_detach_commit(dev)
2187  *
2188  *	Issued by a driver's .ca_detach routine to notify anyone
2189  *	waiting in device_lookup_acquire that the driver is committed
2190  *	to detaching the device, which allows device_lookup_acquire to
2191  *	wake up and fail immediately.
2192  *
2193  *	Safe to call multiple times -- idempotent.  Must be called
2194  *	during config_detach_enter/exit.  Safe to use with
2195  *	device_lookup because the device is not actually removed from
2196  *	the table until after config_detach_exit.
2197  */
2198 void
2199 config_detach_commit(device_t dev)
2200 {
2201 	struct lwp *l __diagused;
2202 
2203 	mutex_enter(&config_misc_lock);
2204 	KASSERTMSG(dev->dv_detaching != NULL, "not detaching %s",
2205 	    device_xname(dev));
2206 	KASSERTMSG((l = dev->dv_detaching) == curlwp,
2207 	    "lwp %ld [%s] @ %p detaching %s",
2208 	    (long)l->l_lid, (l->l_name ? l->l_name : l->l_proc->p_comm), l,
2209 	    device_xname(dev));
2210 	dev->dv_detach_committed = true;
2211 	cv_broadcast(&config_misc_cv);
2212 	mutex_exit(&config_misc_lock);
2213 }
2214 
2215 int
2216 config_detach_children(device_t parent, int flags)
2217 {
2218 	device_t dv;
2219 	deviter_t di;
2220 	int error = 0;
2221 
2222 	KASSERT(KERNEL_LOCKED_P());
2223 
2224 	for (dv = deviter_first(&di, DEVITER_F_RW); dv != NULL;
2225 	     dv = deviter_next(&di)) {
2226 		if (device_parent(dv) != parent)
2227 			continue;
2228 		if ((error = config_detach(dv, flags)) != 0)
2229 			break;
2230 	}
2231 	deviter_release(&di);
2232 	return error;
2233 }
2234 
2235 device_t
2236 shutdown_first(struct shutdown_state *s)
2237 {
2238 	if (!s->initialized) {
2239 		deviter_init(&s->di, DEVITER_F_SHUTDOWN|DEVITER_F_LEAVES_FIRST);
2240 		s->initialized = true;
2241 	}
2242 	return shutdown_next(s);
2243 }
2244 
2245 device_t
2246 shutdown_next(struct shutdown_state *s)
2247 {
2248 	device_t dv;
2249 
2250 	while ((dv = deviter_next(&s->di)) != NULL && !device_is_active(dv))
2251 		;
2252 
2253 	if (dv == NULL)
2254 		s->initialized = false;
2255 
2256 	return dv;
2257 }
2258 
2259 bool
2260 config_detach_all(int how)
2261 {
2262 	static struct shutdown_state s;
2263 	device_t curdev;
2264 	bool progress = false;
2265 	int flags;
2266 
2267 	KERNEL_LOCK(1, NULL);
2268 
2269 	if ((how & (RB_NOSYNC|RB_DUMP)) != 0)
2270 		goto out;
2271 
2272 	if ((how & RB_POWERDOWN) == RB_POWERDOWN)
2273 		flags = DETACH_SHUTDOWN | DETACH_POWEROFF;
2274 	else
2275 		flags = DETACH_SHUTDOWN;
2276 
2277 	for (curdev = shutdown_first(&s); curdev != NULL;
2278 	     curdev = shutdown_next(&s)) {
2279 		aprint_debug(" detaching %s, ", device_xname(curdev));
2280 		if (config_detach(curdev, flags) == 0) {
2281 			progress = true;
2282 			aprint_debug("success.");
2283 		} else
2284 			aprint_debug("failed.");
2285 	}
2286 
2287 out:	KERNEL_UNLOCK_ONE(NULL);
2288 	return progress;
2289 }
2290 
2291 static bool
2292 device_is_ancestor_of(device_t ancestor, device_t descendant)
2293 {
2294 	device_t dv;
2295 
2296 	for (dv = descendant; dv != NULL; dv = device_parent(dv)) {
2297 		if (device_parent(dv) == ancestor)
2298 			return true;
2299 	}
2300 	return false;
2301 }
2302 
2303 int
2304 config_deactivate(device_t dev)
2305 {
2306 	deviter_t di;
2307 	const struct cfattach *ca;
2308 	device_t descendant;
2309 	int s, rv = 0, oflags;
2310 
2311 	for (descendant = deviter_first(&di, DEVITER_F_ROOT_FIRST);
2312 	     descendant != NULL;
2313 	     descendant = deviter_next(&di)) {
2314 		if (dev != descendant &&
2315 		    !device_is_ancestor_of(dev, descendant))
2316 			continue;
2317 
2318 		if ((descendant->dv_flags & DVF_ACTIVE) == 0)
2319 			continue;
2320 
2321 		ca = descendant->dv_cfattach;
2322 		oflags = descendant->dv_flags;
2323 
2324 		descendant->dv_flags &= ~DVF_ACTIVE;
2325 		if (ca->ca_activate == NULL)
2326 			continue;
2327 		s = splhigh();
2328 		rv = (*ca->ca_activate)(descendant, DVACT_DEACTIVATE);
2329 		splx(s);
2330 		if (rv != 0)
2331 			descendant->dv_flags = oflags;
2332 	}
2333 	deviter_release(&di);
2334 	return rv;
2335 }
2336 
2337 /*
2338  * Defer the configuration of the specified device until all
2339  * of its parent's devices have been attached.
2340  */
2341 void
2342 config_defer(device_t dev, void (*func)(device_t))
2343 {
2344 	struct deferred_config *dc;
2345 
2346 	if (dev->dv_parent == NULL)
2347 		panic("config_defer: can't defer config of a root device");
2348 
2349 	dc = kmem_alloc(sizeof(*dc), KM_SLEEP);
2350 
2351 	config_pending_incr(dev);
2352 
2353 	mutex_enter(&config_misc_lock);
2354 #ifdef DIAGNOSTIC
2355 	struct deferred_config *odc;
2356 	TAILQ_FOREACH(odc, &deferred_config_queue, dc_queue) {
2357 		if (odc->dc_dev == dev)
2358 			panic("config_defer: deferred twice");
2359 	}
2360 #endif
2361 	dc->dc_dev = dev;
2362 	dc->dc_func = func;
2363 	TAILQ_INSERT_TAIL(&deferred_config_queue, dc, dc_queue);
2364 	mutex_exit(&config_misc_lock);
2365 }
2366 
2367 /*
2368  * Defer some autoconfiguration for a device until after interrupts
2369  * are enabled.
2370  */
2371 void
2372 config_interrupts(device_t dev, void (*func)(device_t))
2373 {
2374 	struct deferred_config *dc;
2375 
2376 	/*
2377 	 * If interrupts are enabled, callback now.
2378 	 */
2379 	if (cold == 0) {
2380 		(*func)(dev);
2381 		return;
2382 	}
2383 
2384 	dc = kmem_alloc(sizeof(*dc), KM_SLEEP);
2385 
2386 	config_pending_incr(dev);
2387 
2388 	mutex_enter(&config_misc_lock);
2389 #ifdef DIAGNOSTIC
2390 	struct deferred_config *odc;
2391 	TAILQ_FOREACH(odc, &interrupt_config_queue, dc_queue) {
2392 		if (odc->dc_dev == dev)
2393 			panic("config_interrupts: deferred twice");
2394 	}
2395 #endif
2396 	dc->dc_dev = dev;
2397 	dc->dc_func = func;
2398 	TAILQ_INSERT_TAIL(&interrupt_config_queue, dc, dc_queue);
2399 	mutex_exit(&config_misc_lock);
2400 }
2401 
2402 /*
2403  * Defer some autoconfiguration for a device until after root file system
2404  * is mounted (to load firmware etc).
2405  */
2406 void
2407 config_mountroot(device_t dev, void (*func)(device_t))
2408 {
2409 	struct deferred_config *dc;
2410 
2411 	/*
2412 	 * If root file system is mounted, callback now.
2413 	 */
2414 	if (root_is_mounted) {
2415 		(*func)(dev);
2416 		return;
2417 	}
2418 
2419 	dc = kmem_alloc(sizeof(*dc), KM_SLEEP);
2420 
2421 	mutex_enter(&config_misc_lock);
2422 #ifdef DIAGNOSTIC
2423 	struct deferred_config *odc;
2424 	TAILQ_FOREACH(odc, &mountroot_config_queue, dc_queue) {
2425 		if (odc->dc_dev == dev)
2426 			panic("%s: deferred twice", __func__);
2427 	}
2428 #endif
2429 
2430 	dc->dc_dev = dev;
2431 	dc->dc_func = func;
2432 	TAILQ_INSERT_TAIL(&mountroot_config_queue, dc, dc_queue);
2433 	mutex_exit(&config_misc_lock);
2434 }
2435 
2436 /*
2437  * Process a deferred configuration queue.
2438  */
2439 static void
2440 config_process_deferred(struct deferred_config_head *queue, device_t parent)
2441 {
2442 	struct deferred_config *dc;
2443 
2444 	KASSERT(KERNEL_LOCKED_P());
2445 
2446 	mutex_enter(&config_misc_lock);
2447 	dc = TAILQ_FIRST(queue);
2448 	while (dc) {
2449 		if (parent == NULL || dc->dc_dev->dv_parent == parent) {
2450 			TAILQ_REMOVE(queue, dc, dc_queue);
2451 			mutex_exit(&config_misc_lock);
2452 
2453 			(*dc->dc_func)(dc->dc_dev);
2454 			config_pending_decr(dc->dc_dev);
2455 			kmem_free(dc, sizeof(*dc));
2456 
2457 			mutex_enter(&config_misc_lock);
2458 			/* Restart, queue might have changed */
2459 			dc = TAILQ_FIRST(queue);
2460 		} else {
2461 			dc = TAILQ_NEXT(dc, dc_queue);
2462 		}
2463 	}
2464 	mutex_exit(&config_misc_lock);
2465 }
2466 
2467 /*
2468  * Manipulate the config_pending semaphore.
2469  */
2470 void
2471 config_pending_incr(device_t dev)
2472 {
2473 
2474 	mutex_enter(&config_misc_lock);
2475 	KASSERTMSG(dev->dv_pending < INT_MAX,
2476 	    "%s: excess config_pending_incr", device_xname(dev));
2477 	if (dev->dv_pending++ == 0)
2478 		TAILQ_INSERT_TAIL(&config_pending, dev, dv_pending_list);
2479 #ifdef DEBUG_AUTOCONF
2480 	printf("%s: %s %d\n", __func__, device_xname(dev), dev->dv_pending);
2481 #endif
2482 	mutex_exit(&config_misc_lock);
2483 }
2484 
2485 void
2486 config_pending_decr(device_t dev)
2487 {
2488 
2489 	mutex_enter(&config_misc_lock);
2490 	KASSERTMSG(dev->dv_pending > 0,
2491 	    "%s: excess config_pending_decr", device_xname(dev));
2492 	if (--dev->dv_pending == 0) {
2493 		TAILQ_REMOVE(&config_pending, dev, dv_pending_list);
2494 		cv_broadcast(&config_misc_cv);
2495 	}
2496 #ifdef DEBUG_AUTOCONF
2497 	printf("%s: %s %d\n", __func__, device_xname(dev), dev->dv_pending);
2498 #endif
2499 	mutex_exit(&config_misc_lock);
2500 }
2501 
2502 /*
2503  * Register a "finalization" routine.  Finalization routines are
2504  * called iteratively once all real devices have been found during
2505  * autoconfiguration, for as long as any one finalizer has done
2506  * any work.
2507  */
2508 int
2509 config_finalize_register(device_t dev, int (*fn)(device_t))
2510 {
2511 	struct finalize_hook *f;
2512 	int error = 0;
2513 
2514 	KERNEL_LOCK(1, NULL);
2515 
2516 	/*
2517 	 * If finalization has already been done, invoke the
2518 	 * callback function now.
2519 	 */
2520 	if (config_finalize_done) {
2521 		while ((*fn)(dev) != 0)
2522 			/* loop */ ;
2523 		goto out;
2524 	}
2525 
2526 	/* Ensure this isn't already on the list. */
2527 	TAILQ_FOREACH(f, &config_finalize_list, f_list) {
2528 		if (f->f_func == fn && f->f_dev == dev) {
2529 			error = EEXIST;
2530 			goto out;
2531 		}
2532 	}
2533 
2534 	f = kmem_alloc(sizeof(*f), KM_SLEEP);
2535 	f->f_func = fn;
2536 	f->f_dev = dev;
2537 	TAILQ_INSERT_TAIL(&config_finalize_list, f, f_list);
2538 
2539 	/* Success!  */
2540 	error = 0;
2541 
2542 out:	KERNEL_UNLOCK_ONE(NULL);
2543 	return error;
2544 }
2545 
2546 void
2547 config_finalize(void)
2548 {
2549 	struct finalize_hook *f;
2550 	struct pdevinit *pdev;
2551 	extern struct pdevinit pdevinit[];
2552 	int errcnt, rv;
2553 
2554 	/*
2555 	 * Now that device driver threads have been created, wait for
2556 	 * them to finish any deferred autoconfiguration.
2557 	 */
2558 	mutex_enter(&config_misc_lock);
2559 	while (!TAILQ_EMPTY(&config_pending)) {
2560 		device_t dev;
2561 		int error;
2562 
2563 		error = cv_timedwait(&config_misc_cv, &config_misc_lock,
2564 		    mstohz(1000));
2565 		if (error == EWOULDBLOCK) {
2566 			aprint_debug("waiting for devices:");
2567 			TAILQ_FOREACH(dev, &config_pending, dv_pending_list)
2568 				aprint_debug(" %s", device_xname(dev));
2569 			aprint_debug("\n");
2570 		}
2571 	}
2572 	mutex_exit(&config_misc_lock);
2573 
2574 	KERNEL_LOCK(1, NULL);
2575 
2576 	/* Attach pseudo-devices. */
2577 	for (pdev = pdevinit; pdev->pdev_attach != NULL; pdev++)
2578 		(*pdev->pdev_attach)(pdev->pdev_count);
2579 
2580 	/* Run the hooks until none of them does any work. */
2581 	do {
2582 		rv = 0;
2583 		TAILQ_FOREACH(f, &config_finalize_list, f_list)
2584 			rv |= (*f->f_func)(f->f_dev);
2585 	} while (rv != 0);
2586 
2587 	config_finalize_done = 1;
2588 
2589 	/* Now free all the hooks. */
2590 	while ((f = TAILQ_FIRST(&config_finalize_list)) != NULL) {
2591 		TAILQ_REMOVE(&config_finalize_list, f, f_list);
2592 		kmem_free(f, sizeof(*f));
2593 	}
2594 
2595 	KERNEL_UNLOCK_ONE(NULL);
2596 
2597 	errcnt = aprint_get_error_count();
2598 	if ((boothowto & (AB_QUIET|AB_SILENT)) != 0 &&
2599 	    (boothowto & AB_VERBOSE) == 0) {
2600 		mutex_enter(&config_misc_lock);
2601 		if (config_do_twiddle) {
2602 			config_do_twiddle = 0;
2603 			printf_nolog(" done.\n");
2604 		}
2605 		mutex_exit(&config_misc_lock);
2606 	}
2607 	if (errcnt != 0) {
2608 		printf("WARNING: %d error%s while detecting hardware; "
2609 		    "check system log.\n", errcnt,
2610 		    errcnt == 1 ? "" : "s");
2611 	}
2612 }
2613 
2614 void
2615 config_twiddle_init(void)
2616 {
2617 
2618 	if ((boothowto & (AB_SILENT|AB_VERBOSE)) == AB_SILENT) {
2619 		config_do_twiddle = 1;
2620 	}
2621 	callout_setfunc(&config_twiddle_ch, config_twiddle_fn, NULL);
2622 }
2623 
2624 void
2625 config_twiddle_fn(void *cookie)
2626 {
2627 
2628 	mutex_enter(&config_misc_lock);
2629 	if (config_do_twiddle) {
2630 		twiddle();
2631 		callout_schedule(&config_twiddle_ch, mstohz(100));
2632 	}
2633 	mutex_exit(&config_misc_lock);
2634 }
2635 
2636 static void
2637 config_alldevs_enter(struct alldevs_foray *af)
2638 {
2639 	TAILQ_INIT(&af->af_garbage);
2640 	mutex_enter(&alldevs_lock);
2641 	config_collect_garbage(&af->af_garbage);
2642 }
2643 
2644 static void
2645 config_alldevs_exit(struct alldevs_foray *af)
2646 {
2647 	mutex_exit(&alldevs_lock);
2648 	config_dump_garbage(&af->af_garbage);
2649 }
2650 
2651 /*
2652  * device_lookup:
2653  *
2654  *	Look up a device instance for a given driver.
2655  *
2656  *	Caller is responsible for ensuring the device's state is
2657  *	stable, either by holding a reference already obtained with
2658  *	device_lookup_acquire or by otherwise ensuring the device is
2659  *	attached and can't be detached (e.g., holding an open device
2660  *	node and ensuring *_detach calls vdevgone).
2661  *
2662  *	XXX Find a way to assert this.
2663  *
2664  *	Safe for use up to and including interrupt context at IPL_VM.
2665  *	Never sleeps.
2666  */
2667 device_t
2668 device_lookup(cfdriver_t cd, int unit)
2669 {
2670 	device_t dv;
2671 
2672 	mutex_enter(&alldevs_lock);
2673 	if (unit < 0 || unit >= cd->cd_ndevs)
2674 		dv = NULL;
2675 	else if ((dv = cd->cd_devs[unit]) != NULL && dv->dv_del_gen != 0)
2676 		dv = NULL;
2677 	mutex_exit(&alldevs_lock);
2678 
2679 	return dv;
2680 }
2681 
2682 /*
2683  * device_lookup_private:
2684  *
2685  *	Look up a softc instance for a given driver.
2686  */
2687 void *
2688 device_lookup_private(cfdriver_t cd, int unit)
2689 {
2690 
2691 	return device_private(device_lookup(cd, unit));
2692 }
2693 
2694 /*
2695  * device_lookup_acquire:
2696  *
2697  *	Look up a device instance for a given driver, and return a
2698  *	reference to it that must be released by device_release.
2699  *
2700  *	=> If the device is still attaching, blocks until *_attach has
2701  *	   returned.
2702  *
2703  *	=> If the device is detaching, blocks until *_detach has
2704  *	   returned.  May succeed or fail in that case, depending on
2705  *	   whether *_detach has backed out (EBUSY) or committed to
2706  *	   detaching.
2707  *
2708  *	May sleep.
2709  */
2710 device_t
2711 device_lookup_acquire(cfdriver_t cd, int unit)
2712 {
2713 	device_t dv;
2714 
2715 	ASSERT_SLEEPABLE();
2716 
2717 	/* XXX This should have a pserialized fast path -- TBD.  */
2718 	mutex_enter(&config_misc_lock);
2719 	mutex_enter(&alldevs_lock);
2720 retry:	if (unit < 0 || unit >= cd->cd_ndevs ||
2721 	    (dv = cd->cd_devs[unit]) == NULL ||
2722 	    dv->dv_del_gen != 0 ||
2723 	    dv->dv_detach_committed) {
2724 		dv = NULL;
2725 	} else {
2726 		/*
2727 		 * Wait for the device to stabilize, if attaching or
2728 		 * detaching.  Either way we must wait for *_attach or
2729 		 * *_detach to complete, and either way we must retry:
2730 		 * even if detaching, *_detach might fail (EBUSY) so
2731 		 * the device may still be there.
2732 		 */
2733 		if ((dv->dv_attaching != NULL && dv->dv_attaching != curlwp) ||
2734 		    dv->dv_detaching != NULL) {
2735 			mutex_exit(&alldevs_lock);
2736 			cv_wait(&config_misc_cv, &config_misc_lock);
2737 			mutex_enter(&alldevs_lock);
2738 			goto retry;
2739 		}
2740 		localcount_acquire(dv->dv_localcount);
2741 	}
2742 	mutex_exit(&alldevs_lock);
2743 	mutex_exit(&config_misc_lock);
2744 
2745 	return dv;
2746 }
2747 
2748 /*
2749  * device_release:
2750  *
2751  *	Release a reference to a device acquired with
2752  *	device_lookup_acquire.
2753  */
2754 void
2755 device_release(device_t dv)
2756 {
2757 
2758 	localcount_release(dv->dv_localcount,
2759 	    &config_misc_cv, &config_misc_lock);
2760 }
2761 
2762 /*
2763  * device_find_by_xname:
2764  *
2765  *	Returns the device of the given name or NULL if it doesn't exist.
2766  */
2767 device_t
2768 device_find_by_xname(const char *name)
2769 {
2770 	device_t dv;
2771 	deviter_t di;
2772 
2773 	for (dv = deviter_first(&di, 0); dv != NULL; dv = deviter_next(&di)) {
2774 		if (strcmp(device_xname(dv), name) == 0)
2775 			break;
2776 	}
2777 	deviter_release(&di);
2778 
2779 	return dv;
2780 }
2781 
2782 /*
2783  * device_find_by_driver_unit:
2784  *
2785  *	Returns the device of the given driver name and unit or
2786  *	NULL if it doesn't exist.
2787  */
2788 device_t
2789 device_find_by_driver_unit(const char *name, int unit)
2790 {
2791 	struct cfdriver *cd;
2792 
2793 	if ((cd = config_cfdriver_lookup(name)) == NULL)
2794 		return NULL;
2795 	return device_lookup(cd, unit);
2796 }
2797 
2798 static bool
2799 match_strcmp(const char * const s1, const char * const s2)
2800 {
2801 	return strcmp(s1, s2) == 0;
2802 }
2803 
2804 static bool
2805 match_pmatch(const char * const s1, const char * const s2)
2806 {
2807 	return pmatch(s1, s2, NULL) == 2;
2808 }
2809 
2810 static bool
2811 strarray_match_internal(const char ** const strings,
2812     unsigned int const nstrings, const char * const str,
2813     unsigned int * const indexp,
2814     bool (*match_fn)(const char *, const char *))
2815 {
2816 	unsigned int i;
2817 
2818 	if (strings == NULL || nstrings == 0) {
2819 		return false;
2820 	}
2821 
2822 	for (i = 0; i < nstrings; i++) {
2823 		if ((*match_fn)(strings[i], str)) {
2824 			*indexp = i;
2825 			return true;
2826 		}
2827 	}
2828 
2829 	return false;
2830 }
2831 
2832 static int
2833 strarray_match(const char ** const strings, unsigned int const nstrings,
2834     const char * const str)
2835 {
2836 	unsigned int idx;
2837 
2838 	if (strarray_match_internal(strings, nstrings, str, &idx,
2839 				    match_strcmp)) {
2840 		return (int)(nstrings - idx);
2841 	}
2842 	return 0;
2843 }
2844 
2845 static int
2846 strarray_pmatch(const char ** const strings, unsigned int const nstrings,
2847     const char * const pattern)
2848 {
2849 	unsigned int idx;
2850 
2851 	if (strarray_match_internal(strings, nstrings, pattern, &idx,
2852 				    match_pmatch)) {
2853 		return (int)(nstrings - idx);
2854 	}
2855 	return 0;
2856 }
2857 
2858 static int
2859 device_compatible_match_strarray_internal(
2860     const char **device_compats, int ndevice_compats,
2861     const struct device_compatible_entry *driver_compats,
2862     const struct device_compatible_entry **matching_entryp,
2863     int (*match_fn)(const char **, unsigned int, const char *))
2864 {
2865 	const struct device_compatible_entry *dce = NULL;
2866 	int rv;
2867 
2868 	if (ndevice_compats == 0 || device_compats == NULL ||
2869 	    driver_compats == NULL)
2870 		return 0;
2871 
2872 	for (dce = driver_compats; dce->compat != NULL; dce++) {
2873 		rv = (*match_fn)(device_compats, ndevice_compats, dce->compat);
2874 		if (rv != 0) {
2875 			if (matching_entryp != NULL) {
2876 				*matching_entryp = dce;
2877 			}
2878 			return rv;
2879 		}
2880 	}
2881 	return 0;
2882 }
2883 
2884 /*
2885  * device_compatible_match:
2886  *
2887  *	Match a driver's "compatible" data against a device's
2888  *	"compatible" strings.  Returns resulted weighted by
2889  *	which device "compatible" string was matched.
2890  */
2891 int
2892 device_compatible_match(const char **device_compats, int ndevice_compats,
2893     const struct device_compatible_entry *driver_compats)
2894 {
2895 	return device_compatible_match_strarray_internal(device_compats,
2896 	    ndevice_compats, driver_compats, NULL, strarray_match);
2897 }
2898 
2899 /*
2900  * device_compatible_pmatch:
2901  *
2902  *	Like device_compatible_match(), but uses pmatch(9) to compare
2903  *	the device "compatible" strings against patterns in the
2904  *	driver's "compatible" data.
2905  */
2906 int
2907 device_compatible_pmatch(const char **device_compats, int ndevice_compats,
2908     const struct device_compatible_entry *driver_compats)
2909 {
2910 	return device_compatible_match_strarray_internal(device_compats,
2911 	    ndevice_compats, driver_compats, NULL, strarray_pmatch);
2912 }
2913 
2914 static int
2915 device_compatible_match_strlist_internal(
2916     const char * const device_compats, size_t const device_compatsize,
2917     const struct device_compatible_entry *driver_compats,
2918     const struct device_compatible_entry **matching_entryp,
2919     int (*match_fn)(const char *, size_t, const char *))
2920 {
2921 	const struct device_compatible_entry *dce = NULL;
2922 	int rv;
2923 
2924 	if (device_compats == NULL || device_compatsize == 0 ||
2925 	    driver_compats == NULL)
2926 		return 0;
2927 
2928 	for (dce = driver_compats; dce->compat != NULL; dce++) {
2929 		rv = (*match_fn)(device_compats, device_compatsize,
2930 		    dce->compat);
2931 		if (rv != 0) {
2932 			if (matching_entryp != NULL) {
2933 				*matching_entryp = dce;
2934 			}
2935 			return rv;
2936 		}
2937 	}
2938 	return 0;
2939 }
2940 
2941 /*
2942  * device_compatible_match_strlist:
2943  *
2944  *	Like device_compatible_match(), but take the device
2945  *	"compatible" strings as an OpenFirmware-style string
2946  *	list.
2947  */
2948 int
2949 device_compatible_match_strlist(
2950     const char * const device_compats, size_t const device_compatsize,
2951     const struct device_compatible_entry *driver_compats)
2952 {
2953 	return device_compatible_match_strlist_internal(device_compats,
2954 	    device_compatsize, driver_compats, NULL, strlist_match);
2955 }
2956 
2957 /*
2958  * device_compatible_pmatch_strlist:
2959  *
2960  *	Like device_compatible_pmatch(), but take the device
2961  *	"compatible" strings as an OpenFirmware-style string
2962  *	list.
2963  */
2964 int
2965 device_compatible_pmatch_strlist(
2966     const char * const device_compats, size_t const device_compatsize,
2967     const struct device_compatible_entry *driver_compats)
2968 {
2969 	return device_compatible_match_strlist_internal(device_compats,
2970 	    device_compatsize, driver_compats, NULL, strlist_pmatch);
2971 }
2972 
2973 static int
2974 device_compatible_match_id_internal(
2975     uintptr_t const id, uintptr_t const mask, uintptr_t const sentinel_id,
2976     const struct device_compatible_entry *driver_compats,
2977     const struct device_compatible_entry **matching_entryp)
2978 {
2979 	const struct device_compatible_entry *dce = NULL;
2980 
2981 	if (mask == 0)
2982 		return 0;
2983 
2984 	for (dce = driver_compats; dce->id != sentinel_id; dce++) {
2985 		if ((id & mask) == dce->id) {
2986 			if (matching_entryp != NULL) {
2987 				*matching_entryp = dce;
2988 			}
2989 			return 1;
2990 		}
2991 	}
2992 	return 0;
2993 }
2994 
2995 /*
2996  * device_compatible_match_id:
2997  *
2998  *	Like device_compatible_match(), but takes a single
2999  *	unsigned integer device ID.
3000  */
3001 int
3002 device_compatible_match_id(
3003     uintptr_t const id, uintptr_t const sentinel_id,
3004     const struct device_compatible_entry *driver_compats)
3005 {
3006 	return device_compatible_match_id_internal(id, (uintptr_t)-1,
3007 	    sentinel_id, driver_compats, NULL);
3008 }
3009 
3010 /*
3011  * device_compatible_lookup:
3012  *
3013  *	Look up and return the device_compatible_entry, using the
3014  *	same matching criteria used by device_compatible_match().
3015  */
3016 const struct device_compatible_entry *
3017 device_compatible_lookup(const char **device_compats, int ndevice_compats,
3018 			 const struct device_compatible_entry *driver_compats)
3019 {
3020 	const struct device_compatible_entry *dce;
3021 
3022 	if (device_compatible_match_strarray_internal(device_compats,
3023 	    ndevice_compats, driver_compats, &dce, strarray_match)) {
3024 		return dce;
3025 	}
3026 	return NULL;
3027 }
3028 
3029 /*
3030  * device_compatible_plookup:
3031  *
3032  *	Look up and return the device_compatible_entry, using the
3033  *	same matching criteria used by device_compatible_pmatch().
3034  */
3035 const struct device_compatible_entry *
3036 device_compatible_plookup(const char **device_compats, int ndevice_compats,
3037 			  const struct device_compatible_entry *driver_compats)
3038 {
3039 	const struct device_compatible_entry *dce;
3040 
3041 	if (device_compatible_match_strarray_internal(device_compats,
3042 	    ndevice_compats, driver_compats, &dce, strarray_pmatch)) {
3043 		return dce;
3044 	}
3045 	return NULL;
3046 }
3047 
3048 /*
3049  * device_compatible_lookup_strlist:
3050  *
3051  *	Like device_compatible_lookup(), but take the device
3052  *	"compatible" strings as an OpenFirmware-style string
3053  *	list.
3054  */
3055 const struct device_compatible_entry *
3056 device_compatible_lookup_strlist(
3057     const char * const device_compats, size_t const device_compatsize,
3058     const struct device_compatible_entry *driver_compats)
3059 {
3060 	const struct device_compatible_entry *dce;
3061 
3062 	if (device_compatible_match_strlist_internal(device_compats,
3063 	    device_compatsize, driver_compats, &dce, strlist_match)) {
3064 		return dce;
3065 	}
3066 	return NULL;
3067 }
3068 
3069 /*
3070  * device_compatible_plookup_strlist:
3071  *
3072  *	Like device_compatible_plookup(), but take the device
3073  *	"compatible" strings as an OpenFirmware-style string
3074  *	list.
3075  */
3076 const struct device_compatible_entry *
3077 device_compatible_plookup_strlist(
3078     const char * const device_compats, size_t const device_compatsize,
3079     const struct device_compatible_entry *driver_compats)
3080 {
3081 	const struct device_compatible_entry *dce;
3082 
3083 	if (device_compatible_match_strlist_internal(device_compats,
3084 	    device_compatsize, driver_compats, &dce, strlist_pmatch)) {
3085 		return dce;
3086 	}
3087 	return NULL;
3088 }
3089 
3090 /*
3091  * device_compatible_lookup_id:
3092  *
3093  *	Like device_compatible_lookup(), but takes a single
3094  *	unsigned integer device ID.
3095  */
3096 const struct device_compatible_entry *
3097 device_compatible_lookup_id(
3098     uintptr_t const id, uintptr_t const sentinel_id,
3099     const struct device_compatible_entry *driver_compats)
3100 {
3101 	const struct device_compatible_entry *dce;
3102 
3103 	if (device_compatible_match_id_internal(id, (uintptr_t)-1,
3104 	    sentinel_id, driver_compats, &dce)) {
3105 		return dce;
3106 	}
3107 	return NULL;
3108 }
3109 
3110 /*
3111  * Power management related functions.
3112  */
3113 
3114 bool
3115 device_pmf_is_registered(device_t dev)
3116 {
3117 	return (dev->dv_flags & DVF_POWER_HANDLERS) != 0;
3118 }
3119 
3120 bool
3121 device_pmf_driver_suspend(device_t dev, const pmf_qual_t *qual)
3122 {
3123 	if ((dev->dv_flags & DVF_DRIVER_SUSPENDED) != 0)
3124 		return true;
3125 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) == 0)
3126 		return false;
3127 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_DRIVER &&
3128 	    dev->dv_driver_suspend != NULL &&
3129 	    !(*dev->dv_driver_suspend)(dev, qual))
3130 		return false;
3131 
3132 	dev->dv_flags |= DVF_DRIVER_SUSPENDED;
3133 	return true;
3134 }
3135 
3136 bool
3137 device_pmf_driver_resume(device_t dev, const pmf_qual_t *qual)
3138 {
3139 	if ((dev->dv_flags & DVF_DRIVER_SUSPENDED) == 0)
3140 		return true;
3141 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) != 0)
3142 		return false;
3143 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_DRIVER &&
3144 	    dev->dv_driver_resume != NULL &&
3145 	    !(*dev->dv_driver_resume)(dev, qual))
3146 		return false;
3147 
3148 	dev->dv_flags &= ~DVF_DRIVER_SUSPENDED;
3149 	return true;
3150 }
3151 
3152 bool
3153 device_pmf_driver_shutdown(device_t dev, int how)
3154 {
3155 
3156 	if (*dev->dv_driver_shutdown != NULL &&
3157 	    !(*dev->dv_driver_shutdown)(dev, how))
3158 		return false;
3159 	return true;
3160 }
3161 
3162 void
3163 device_pmf_driver_register(device_t dev,
3164     bool (*suspend)(device_t, const pmf_qual_t *),
3165     bool (*resume)(device_t, const pmf_qual_t *),
3166     bool (*shutdown)(device_t, int))
3167 {
3168 
3169 	dev->dv_driver_suspend = suspend;
3170 	dev->dv_driver_resume = resume;
3171 	dev->dv_driver_shutdown = shutdown;
3172 	dev->dv_flags |= DVF_POWER_HANDLERS;
3173 }
3174 
3175 void
3176 device_pmf_driver_deregister(device_t dev)
3177 {
3178 	device_lock_t dvl = device_getlock(dev);
3179 
3180 	dev->dv_driver_suspend = NULL;
3181 	dev->dv_driver_resume = NULL;
3182 
3183 	mutex_enter(&dvl->dvl_mtx);
3184 	dev->dv_flags &= ~DVF_POWER_HANDLERS;
3185 	while (dvl->dvl_nlock > 0 || dvl->dvl_nwait > 0) {
3186 		/* Wake a thread that waits for the lock.  That
3187 		 * thread will fail to acquire the lock, and then
3188 		 * it will wake the next thread that waits for the
3189 		 * lock, or else it will wake us.
3190 		 */
3191 		cv_signal(&dvl->dvl_cv);
3192 		pmflock_debug(dev, __func__, __LINE__);
3193 		cv_wait(&dvl->dvl_cv, &dvl->dvl_mtx);
3194 		pmflock_debug(dev, __func__, __LINE__);
3195 	}
3196 	mutex_exit(&dvl->dvl_mtx);
3197 }
3198 
3199 void
3200 device_pmf_driver_child_register(device_t dev)
3201 {
3202 	device_t parent = device_parent(dev);
3203 
3204 	if (parent == NULL || parent->dv_driver_child_register == NULL)
3205 		return;
3206 	(*parent->dv_driver_child_register)(dev);
3207 }
3208 
3209 void
3210 device_pmf_driver_set_child_register(device_t dev,
3211     void (*child_register)(device_t))
3212 {
3213 	dev->dv_driver_child_register = child_register;
3214 }
3215 
3216 static void
3217 pmflock_debug(device_t dev, const char *func, int line)
3218 {
3219 #ifdef PMFLOCK_DEBUG
3220 	device_lock_t dvl = device_getlock(dev);
3221 	const char *curlwp_name;
3222 
3223 	if (curlwp->l_name != NULL)
3224 		curlwp_name = curlwp->l_name;
3225 	else
3226 		curlwp_name = curlwp->l_proc->p_comm;
3227 
3228 	aprint_debug_dev(dev,
3229 	    "%s.%d, %s dvl_nlock %d dvl_nwait %d dv_flags %x\n", func, line,
3230 	    curlwp_name, dvl->dvl_nlock, dvl->dvl_nwait, dev->dv_flags);
3231 #endif	/* PMFLOCK_DEBUG */
3232 }
3233 
3234 static bool
3235 device_pmf_lock1(device_t dev)
3236 {
3237 	device_lock_t dvl = device_getlock(dev);
3238 
3239 	while (device_pmf_is_registered(dev) &&
3240 	    dvl->dvl_nlock > 0 && dvl->dvl_holder != curlwp) {
3241 		dvl->dvl_nwait++;
3242 		pmflock_debug(dev, __func__, __LINE__);
3243 		cv_wait(&dvl->dvl_cv, &dvl->dvl_mtx);
3244 		pmflock_debug(dev, __func__, __LINE__);
3245 		dvl->dvl_nwait--;
3246 	}
3247 	if (!device_pmf_is_registered(dev)) {
3248 		pmflock_debug(dev, __func__, __LINE__);
3249 		/* We could not acquire the lock, but some other thread may
3250 		 * wait for it, also.  Wake that thread.
3251 		 */
3252 		cv_signal(&dvl->dvl_cv);
3253 		return false;
3254 	}
3255 	dvl->dvl_nlock++;
3256 	dvl->dvl_holder = curlwp;
3257 	pmflock_debug(dev, __func__, __LINE__);
3258 	return true;
3259 }
3260 
3261 bool
3262 device_pmf_lock(device_t dev)
3263 {
3264 	bool rc;
3265 	device_lock_t dvl = device_getlock(dev);
3266 
3267 	mutex_enter(&dvl->dvl_mtx);
3268 	rc = device_pmf_lock1(dev);
3269 	mutex_exit(&dvl->dvl_mtx);
3270 
3271 	return rc;
3272 }
3273 
3274 void
3275 device_pmf_unlock(device_t dev)
3276 {
3277 	device_lock_t dvl = device_getlock(dev);
3278 
3279 	KASSERT(dvl->dvl_nlock > 0);
3280 	mutex_enter(&dvl->dvl_mtx);
3281 	if (--dvl->dvl_nlock == 0)
3282 		dvl->dvl_holder = NULL;
3283 	cv_signal(&dvl->dvl_cv);
3284 	pmflock_debug(dev, __func__, __LINE__);
3285 	mutex_exit(&dvl->dvl_mtx);
3286 }
3287 
3288 device_lock_t
3289 device_getlock(device_t dev)
3290 {
3291 	return &dev->dv_lock;
3292 }
3293 
3294 void *
3295 device_pmf_bus_private(device_t dev)
3296 {
3297 	return dev->dv_bus_private;
3298 }
3299 
3300 bool
3301 device_pmf_bus_suspend(device_t dev, const pmf_qual_t *qual)
3302 {
3303 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) != 0)
3304 		return true;
3305 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) == 0 ||
3306 	    (dev->dv_flags & DVF_DRIVER_SUSPENDED) == 0)
3307 		return false;
3308 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_BUS &&
3309 	    dev->dv_bus_suspend != NULL &&
3310 	    !(*dev->dv_bus_suspend)(dev, qual))
3311 		return false;
3312 
3313 	dev->dv_flags |= DVF_BUS_SUSPENDED;
3314 	return true;
3315 }
3316 
3317 bool
3318 device_pmf_bus_resume(device_t dev, const pmf_qual_t *qual)
3319 {
3320 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) == 0)
3321 		return true;
3322 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_BUS &&
3323 	    dev->dv_bus_resume != NULL &&
3324 	    !(*dev->dv_bus_resume)(dev, qual))
3325 		return false;
3326 
3327 	dev->dv_flags &= ~DVF_BUS_SUSPENDED;
3328 	return true;
3329 }
3330 
3331 bool
3332 device_pmf_bus_shutdown(device_t dev, int how)
3333 {
3334 
3335 	if (*dev->dv_bus_shutdown != NULL &&
3336 	    !(*dev->dv_bus_shutdown)(dev, how))
3337 		return false;
3338 	return true;
3339 }
3340 
3341 void
3342 device_pmf_bus_register(device_t dev, void *priv,
3343     bool (*suspend)(device_t, const pmf_qual_t *),
3344     bool (*resume)(device_t, const pmf_qual_t *),
3345     bool (*shutdown)(device_t, int), void (*deregister)(device_t))
3346 {
3347 	dev->dv_bus_private = priv;
3348 	dev->dv_bus_resume = resume;
3349 	dev->dv_bus_suspend = suspend;
3350 	dev->dv_bus_shutdown = shutdown;
3351 	dev->dv_bus_deregister = deregister;
3352 }
3353 
3354 void
3355 device_pmf_bus_deregister(device_t dev)
3356 {
3357 	if (dev->dv_bus_deregister == NULL)
3358 		return;
3359 	(*dev->dv_bus_deregister)(dev);
3360 	dev->dv_bus_private = NULL;
3361 	dev->dv_bus_suspend = NULL;
3362 	dev->dv_bus_resume = NULL;
3363 	dev->dv_bus_deregister = NULL;
3364 }
3365 
3366 void *
3367 device_pmf_class_private(device_t dev)
3368 {
3369 	return dev->dv_class_private;
3370 }
3371 
3372 bool
3373 device_pmf_class_suspend(device_t dev, const pmf_qual_t *qual)
3374 {
3375 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) != 0)
3376 		return true;
3377 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_CLASS &&
3378 	    dev->dv_class_suspend != NULL &&
3379 	    !(*dev->dv_class_suspend)(dev, qual))
3380 		return false;
3381 
3382 	dev->dv_flags |= DVF_CLASS_SUSPENDED;
3383 	return true;
3384 }
3385 
3386 bool
3387 device_pmf_class_resume(device_t dev, const pmf_qual_t *qual)
3388 {
3389 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) == 0)
3390 		return true;
3391 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) != 0 ||
3392 	    (dev->dv_flags & DVF_DRIVER_SUSPENDED) != 0)
3393 		return false;
3394 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_CLASS &&
3395 	    dev->dv_class_resume != NULL &&
3396 	    !(*dev->dv_class_resume)(dev, qual))
3397 		return false;
3398 
3399 	dev->dv_flags &= ~DVF_CLASS_SUSPENDED;
3400 	return true;
3401 }
3402 
3403 void
3404 device_pmf_class_register(device_t dev, void *priv,
3405     bool (*suspend)(device_t, const pmf_qual_t *),
3406     bool (*resume)(device_t, const pmf_qual_t *),
3407     void (*deregister)(device_t))
3408 {
3409 	dev->dv_class_private = priv;
3410 	dev->dv_class_suspend = suspend;
3411 	dev->dv_class_resume = resume;
3412 	dev->dv_class_deregister = deregister;
3413 }
3414 
3415 void
3416 device_pmf_class_deregister(device_t dev)
3417 {
3418 	if (dev->dv_class_deregister == NULL)
3419 		return;
3420 	(*dev->dv_class_deregister)(dev);
3421 	dev->dv_class_private = NULL;
3422 	dev->dv_class_suspend = NULL;
3423 	dev->dv_class_resume = NULL;
3424 	dev->dv_class_deregister = NULL;
3425 }
3426 
3427 bool
3428 device_active(device_t dev, devactive_t type)
3429 {
3430 	size_t i;
3431 
3432 	if (dev->dv_activity_count == 0)
3433 		return false;
3434 
3435 	for (i = 0; i < dev->dv_activity_count; ++i) {
3436 		if (dev->dv_activity_handlers[i] == NULL)
3437 			break;
3438 		(*dev->dv_activity_handlers[i])(dev, type);
3439 	}
3440 
3441 	return true;
3442 }
3443 
3444 bool
3445 device_active_register(device_t dev, void (*handler)(device_t, devactive_t))
3446 {
3447 	void (**new_handlers)(device_t, devactive_t);
3448 	void (**old_handlers)(device_t, devactive_t);
3449 	size_t i, old_size, new_size;
3450 	int s;
3451 
3452 	old_handlers = dev->dv_activity_handlers;
3453 	old_size = dev->dv_activity_count;
3454 
3455 	KASSERT(old_size == 0 || old_handlers != NULL);
3456 
3457 	for (i = 0; i < old_size; ++i) {
3458 		KASSERT(old_handlers[i] != handler);
3459 		if (old_handlers[i] == NULL) {
3460 			old_handlers[i] = handler;
3461 			return true;
3462 		}
3463 	}
3464 
3465 	new_size = old_size + 4;
3466 	new_handlers = kmem_alloc(sizeof(void *) * new_size, KM_SLEEP);
3467 
3468 	for (i = 0; i < old_size; ++i)
3469 		new_handlers[i] = old_handlers[i];
3470 	new_handlers[old_size] = handler;
3471 	for (i = old_size+1; i < new_size; ++i)
3472 		new_handlers[i] = NULL;
3473 
3474 	s = splhigh();
3475 	dev->dv_activity_count = new_size;
3476 	dev->dv_activity_handlers = new_handlers;
3477 	splx(s);
3478 
3479 	if (old_size > 0)
3480 		kmem_free(old_handlers, sizeof(void *) * old_size);
3481 
3482 	return true;
3483 }
3484 
3485 void
3486 device_active_deregister(device_t dev, void (*handler)(device_t, devactive_t))
3487 {
3488 	void (**old_handlers)(device_t, devactive_t);
3489 	size_t i, old_size;
3490 	int s;
3491 
3492 	old_handlers = dev->dv_activity_handlers;
3493 	old_size = dev->dv_activity_count;
3494 
3495 	for (i = 0; i < old_size; ++i) {
3496 		if (old_handlers[i] == handler)
3497 			break;
3498 		if (old_handlers[i] == NULL)
3499 			return; /* XXX panic? */
3500 	}
3501 
3502 	if (i == old_size)
3503 		return; /* XXX panic? */
3504 
3505 	for (; i < old_size - 1; ++i) {
3506 		if ((old_handlers[i] = old_handlers[i + 1]) != NULL)
3507 			continue;
3508 
3509 		if (i == 0) {
3510 			s = splhigh();
3511 			dev->dv_activity_count = 0;
3512 			dev->dv_activity_handlers = NULL;
3513 			splx(s);
3514 			kmem_free(old_handlers, sizeof(void *) * old_size);
3515 		}
3516 		return;
3517 	}
3518 	old_handlers[i] = NULL;
3519 }
3520 
3521 /* Return true iff the device_t `dev' exists at generation `gen'. */
3522 static bool
3523 device_exists_at(device_t dv, devgen_t gen)
3524 {
3525 	return (dv->dv_del_gen == 0 || dv->dv_del_gen > gen) &&
3526 	    dv->dv_add_gen <= gen;
3527 }
3528 
3529 static bool
3530 deviter_visits(const deviter_t *di, device_t dv)
3531 {
3532 	return device_exists_at(dv, di->di_gen);
3533 }
3534 
3535 /*
3536  * Device Iteration
3537  *
3538  * deviter_t: a device iterator.  Holds state for a "walk" visiting
3539  *     each device_t's in the device tree.
3540  *
3541  * deviter_init(di, flags): initialize the device iterator `di'
3542  *     to "walk" the device tree.  deviter_next(di) will return
3543  *     the first device_t in the device tree, or NULL if there are
3544  *     no devices.
3545  *
3546  *     `flags' is one or more of DEVITER_F_RW, indicating that the
3547  *     caller intends to modify the device tree by calling
3548  *     config_detach(9) on devices in the order that the iterator
3549  *     returns them; DEVITER_F_ROOT_FIRST, asking for the devices
3550  *     nearest the "root" of the device tree to be returned, first;
3551  *     DEVITER_F_LEAVES_FIRST, asking for the devices furthest from
3552  *     the root of the device tree, first; and DEVITER_F_SHUTDOWN,
3553  *     indicating both that deviter_init() should not respect any
3554  *     locks on the device tree, and that deviter_next(di) may run
3555  *     in more than one LWP before the walk has finished.
3556  *
3557  *     Only one DEVITER_F_RW iterator may be in the device tree at
3558  *     once.
3559  *
3560  *     DEVITER_F_SHUTDOWN implies DEVITER_F_RW.
3561  *
3562  *     Results are undefined if the flags DEVITER_F_ROOT_FIRST and
3563  *     DEVITER_F_LEAVES_FIRST are used in combination.
3564  *
3565  * deviter_first(di, flags): initialize the device iterator `di'
3566  *     and return the first device_t in the device tree, or NULL
3567  *     if there are no devices.  The statement
3568  *
3569  *         dv = deviter_first(di);
3570  *
3571  *     is shorthand for
3572  *
3573  *         deviter_init(di);
3574  *         dv = deviter_next(di);
3575  *
3576  * deviter_next(di): return the next device_t in the device tree,
3577  *     or NULL if there are no more devices.  deviter_next(di)
3578  *     is undefined if `di' was not initialized with deviter_init() or
3579  *     deviter_first().
3580  *
3581  * deviter_release(di): stops iteration (subsequent calls to
3582  *     deviter_next() will return NULL), releases any locks and
3583  *     resources held by the device iterator.
3584  *
3585  * Device iteration does not return device_t's in any particular
3586  * order.  An iterator will never return the same device_t twice.
3587  * Device iteration is guaranteed to complete---i.e., if deviter_next(di)
3588  * is called repeatedly on the same `di', it will eventually return
3589  * NULL.  It is ok to attach/detach devices during device iteration.
3590  */
3591 void
3592 deviter_init(deviter_t *di, deviter_flags_t flags)
3593 {
3594 	device_t dv;
3595 
3596 	memset(di, 0, sizeof(*di));
3597 
3598 	if ((flags & DEVITER_F_SHUTDOWN) != 0)
3599 		flags |= DEVITER_F_RW;
3600 
3601 	mutex_enter(&alldevs_lock);
3602 	if ((flags & DEVITER_F_RW) != 0)
3603 		alldevs_nwrite++;
3604 	else
3605 		alldevs_nread++;
3606 	di->di_gen = alldevs_gen++;
3607 	di->di_flags = flags;
3608 
3609 	switch (di->di_flags & (DEVITER_F_LEAVES_FIRST|DEVITER_F_ROOT_FIRST)) {
3610 	case DEVITER_F_LEAVES_FIRST:
3611 		TAILQ_FOREACH(dv, &alldevs, dv_list) {
3612 			if (!deviter_visits(di, dv))
3613 				continue;
3614 			di->di_curdepth = MAX(di->di_curdepth, dv->dv_depth);
3615 		}
3616 		break;
3617 	case DEVITER_F_ROOT_FIRST:
3618 		TAILQ_FOREACH(dv, &alldevs, dv_list) {
3619 			if (!deviter_visits(di, dv))
3620 				continue;
3621 			di->di_maxdepth = MAX(di->di_maxdepth, dv->dv_depth);
3622 		}
3623 		break;
3624 	default:
3625 		break;
3626 	}
3627 
3628 	deviter_reinit(di);
3629 	mutex_exit(&alldevs_lock);
3630 }
3631 
3632 static void
3633 deviter_reinit(deviter_t *di)
3634 {
3635 
3636 	KASSERT(mutex_owned(&alldevs_lock));
3637 	if ((di->di_flags & DEVITER_F_RW) != 0)
3638 		di->di_prev = TAILQ_LAST(&alldevs, devicelist);
3639 	else
3640 		di->di_prev = TAILQ_FIRST(&alldevs);
3641 }
3642 
3643 device_t
3644 deviter_first(deviter_t *di, deviter_flags_t flags)
3645 {
3646 
3647 	deviter_init(di, flags);
3648 	return deviter_next(di);
3649 }
3650 
3651 static device_t
3652 deviter_next2(deviter_t *di)
3653 {
3654 	device_t dv;
3655 
3656 	KASSERT(mutex_owned(&alldevs_lock));
3657 
3658 	dv = di->di_prev;
3659 
3660 	if (dv == NULL)
3661 		return NULL;
3662 
3663 	if ((di->di_flags & DEVITER_F_RW) != 0)
3664 		di->di_prev = TAILQ_PREV(dv, devicelist, dv_list);
3665 	else
3666 		di->di_prev = TAILQ_NEXT(dv, dv_list);
3667 
3668 	return dv;
3669 }
3670 
3671 static device_t
3672 deviter_next1(deviter_t *di)
3673 {
3674 	device_t dv;
3675 
3676 	KASSERT(mutex_owned(&alldevs_lock));
3677 
3678 	do {
3679 		dv = deviter_next2(di);
3680 	} while (dv != NULL && !deviter_visits(di, dv));
3681 
3682 	return dv;
3683 }
3684 
3685 device_t
3686 deviter_next(deviter_t *di)
3687 {
3688 	device_t dv = NULL;
3689 
3690 	mutex_enter(&alldevs_lock);
3691 	switch (di->di_flags & (DEVITER_F_LEAVES_FIRST|DEVITER_F_ROOT_FIRST)) {
3692 	case 0:
3693 		dv = deviter_next1(di);
3694 		break;
3695 	case DEVITER_F_LEAVES_FIRST:
3696 		while (di->di_curdepth >= 0) {
3697 			if ((dv = deviter_next1(di)) == NULL) {
3698 				di->di_curdepth--;
3699 				deviter_reinit(di);
3700 			} else if (dv->dv_depth == di->di_curdepth)
3701 				break;
3702 		}
3703 		break;
3704 	case DEVITER_F_ROOT_FIRST:
3705 		while (di->di_curdepth <= di->di_maxdepth) {
3706 			if ((dv = deviter_next1(di)) == NULL) {
3707 				di->di_curdepth++;
3708 				deviter_reinit(di);
3709 			} else if (dv->dv_depth == di->di_curdepth)
3710 				break;
3711 		}
3712 		break;
3713 	default:
3714 		break;
3715 	}
3716 	mutex_exit(&alldevs_lock);
3717 
3718 	return dv;
3719 }
3720 
3721 void
3722 deviter_release(deviter_t *di)
3723 {
3724 	bool rw = (di->di_flags & DEVITER_F_RW) != 0;
3725 
3726 	mutex_enter(&alldevs_lock);
3727 	if (rw)
3728 		--alldevs_nwrite;
3729 	else
3730 		--alldevs_nread;
3731 	/* XXX wake a garbage-collection thread */
3732 	mutex_exit(&alldevs_lock);
3733 }
3734 
3735 const char *
3736 cfdata_ifattr(const struct cfdata *cf)
3737 {
3738 	return cf->cf_pspec->cfp_iattr;
3739 }
3740 
3741 bool
3742 ifattr_match(const char *snull, const char *t)
3743 {
3744 	return (snull == NULL) || strcmp(snull, t) == 0;
3745 }
3746 
3747 void
3748 null_childdetached(device_t self, device_t child)
3749 {
3750 	/* do nothing */
3751 }
3752 
3753 static void
3754 sysctl_detach_setup(struct sysctllog **clog)
3755 {
3756 
3757 	sysctl_createv(clog, 0, NULL, NULL,
3758 		CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
3759 		CTLTYPE_BOOL, "detachall",
3760 		SYSCTL_DESCR("Detach all devices at shutdown"),
3761 		NULL, 0, &detachall, 0,
3762 		CTL_KERN, CTL_CREATE, CTL_EOL);
3763 }
3764