xref: /netbsd-src/sys/kern/subr_autoconf.c (revision a24efa7dea9f1f56c3bdb15a927d3516792ace1c)
1 /* $NetBSD: subr_autoconf.c,v 1.241 2016/03/28 09:50:40 skrll 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 1.241 2016/03/28 09:50:40 skrll Exp $");
81 
82 #ifdef _KERNEL_OPT
83 #include "opt_ddb.h"
84 #include "drvctl.h"
85 #endif
86 
87 #include <sys/param.h>
88 #include <sys/device.h>
89 #include <sys/disklabel.h>
90 #include <sys/conf.h>
91 #include <sys/kauth.h>
92 #include <sys/kmem.h>
93 #include <sys/systm.h>
94 #include <sys/kernel.h>
95 #include <sys/errno.h>
96 #include <sys/proc.h>
97 #include <sys/reboot.h>
98 #include <sys/kthread.h>
99 #include <sys/buf.h>
100 #include <sys/dirent.h>
101 #include <sys/mount.h>
102 #include <sys/namei.h>
103 #include <sys/unistd.h>
104 #include <sys/fcntl.h>
105 #include <sys/lockf.h>
106 #include <sys/callout.h>
107 #include <sys/devmon.h>
108 #include <sys/cpu.h>
109 #include <sys/sysctl.h>
110 
111 #include <sys/disk.h>
112 
113 #include <sys/rndsource.h>
114 
115 #include <machine/limits.h>
116 
117 /*
118  * Autoconfiguration subroutines.
119  */
120 
121 /*
122  * Device autoconfiguration timings are mixed into the entropy pool.
123  */
124 extern krndsource_t rnd_autoconf_source;
125 
126 /*
127  * ioconf.c exports exactly two names: cfdata and cfroots.  All system
128  * devices and drivers are found via these tables.
129  */
130 extern struct cfdata cfdata[];
131 extern const short cfroots[];
132 
133 /*
134  * List of all cfdriver structures.  We use this to detect duplicates
135  * when other cfdrivers are loaded.
136  */
137 struct cfdriverlist allcfdrivers = LIST_HEAD_INITIALIZER(&allcfdrivers);
138 extern struct cfdriver * const cfdriver_list_initial[];
139 
140 /*
141  * Initial list of cfattach's.
142  */
143 extern const struct cfattachinit cfattachinit[];
144 
145 /*
146  * List of cfdata tables.  We always have one such list -- the one
147  * built statically when the kernel was configured.
148  */
149 struct cftablelist allcftables = TAILQ_HEAD_INITIALIZER(allcftables);
150 static struct cftable initcftable;
151 
152 #define	ROOT ((device_t)NULL)
153 
154 struct matchinfo {
155 	cfsubmatch_t fn;
156 	device_t parent;
157 	const int *locs;
158 	void	*aux;
159 	struct	cfdata *match;
160 	int	pri;
161 };
162 
163 struct alldevs_foray {
164 	int			af_s;
165 	struct devicelist	af_garbage;
166 };
167 
168 static char *number(char *, int);
169 static void mapply(struct matchinfo *, cfdata_t);
170 static device_t config_devalloc(const device_t, const cfdata_t, const int *);
171 static void config_devdelete(device_t);
172 static void config_devunlink(device_t, struct devicelist *);
173 static void config_makeroom(int, struct cfdriver *);
174 static void config_devlink(device_t);
175 static void config_alldevs_enter(struct alldevs_foray *);
176 static void config_alldevs_exit(struct alldevs_foray *);
177 static void config_add_attrib_dict(device_t);
178 
179 static void config_collect_garbage(struct devicelist *);
180 static void config_dump_garbage(struct devicelist *);
181 
182 static void pmflock_debug(device_t, const char *, int);
183 
184 static device_t deviter_next1(deviter_t *);
185 static void deviter_reinit(deviter_t *);
186 
187 struct deferred_config {
188 	TAILQ_ENTRY(deferred_config) dc_queue;
189 	device_t dc_dev;
190 	void (*dc_func)(device_t);
191 };
192 
193 TAILQ_HEAD(deferred_config_head, deferred_config);
194 
195 struct deferred_config_head deferred_config_queue =
196 	TAILQ_HEAD_INITIALIZER(deferred_config_queue);
197 struct deferred_config_head interrupt_config_queue =
198 	TAILQ_HEAD_INITIALIZER(interrupt_config_queue);
199 int interrupt_config_threads = 8;
200 struct deferred_config_head mountroot_config_queue =
201 	TAILQ_HEAD_INITIALIZER(mountroot_config_queue);
202 int mountroot_config_threads = 2;
203 static lwp_t **mountroot_config_lwpids;
204 static size_t mountroot_config_lwpids_size;
205 static bool root_is_mounted = false;
206 
207 static void config_process_deferred(struct deferred_config_head *, device_t);
208 
209 /* Hooks to finalize configuration once all real devices have been found. */
210 struct finalize_hook {
211 	TAILQ_ENTRY(finalize_hook) f_list;
212 	int (*f_func)(device_t);
213 	device_t f_dev;
214 };
215 static TAILQ_HEAD(, finalize_hook) config_finalize_list =
216 	TAILQ_HEAD_INITIALIZER(config_finalize_list);
217 static int config_finalize_done;
218 
219 /* list of all devices */
220 static struct devicelist alldevs = TAILQ_HEAD_INITIALIZER(alldevs);
221 static kmutex_t alldevs_mtx;
222 static volatile bool alldevs_garbage = false;
223 static volatile devgen_t alldevs_gen = 1;
224 static volatile int alldevs_nread = 0;
225 static volatile int alldevs_nwrite = 0;
226 
227 static int config_pending;		/* semaphore for mountroot */
228 static kmutex_t config_misc_lock;
229 static kcondvar_t config_misc_cv;
230 
231 static bool detachall = false;
232 
233 #define	STREQ(s1, s2)			\
234 	(*(s1) == *(s2) && strcmp((s1), (s2)) == 0)
235 
236 static bool config_initialized = false;	/* config_init() has been called. */
237 
238 static int config_do_twiddle;
239 static callout_t config_twiddle_ch;
240 
241 static void sysctl_detach_setup(struct sysctllog **);
242 
243 int no_devmon_insert(const char *, prop_dictionary_t);
244 int (*devmon_insert_vec)(const char *, prop_dictionary_t) = no_devmon_insert;
245 
246 typedef int (*cfdriver_fn)(struct cfdriver *);
247 static int
248 frob_cfdrivervec(struct cfdriver * const *cfdriverv,
249 	cfdriver_fn drv_do, cfdriver_fn drv_undo,
250 	const char *style, bool dopanic)
251 {
252 	void (*pr)(const char *, ...) __printflike(1, 2) =
253 	    dopanic ? panic : printf;
254 	int i, error = 0, e2 __diagused;
255 
256 	for (i = 0; cfdriverv[i] != NULL; i++) {
257 		if ((error = drv_do(cfdriverv[i])) != 0) {
258 			pr("configure: `%s' driver %s failed: %d",
259 			    cfdriverv[i]->cd_name, style, error);
260 			goto bad;
261 		}
262 	}
263 
264 	KASSERT(error == 0);
265 	return 0;
266 
267  bad:
268 	printf("\n");
269 	for (i--; i >= 0; i--) {
270 		e2 = drv_undo(cfdriverv[i]);
271 		KASSERT(e2 == 0);
272 	}
273 
274 	return error;
275 }
276 
277 typedef int (*cfattach_fn)(const char *, struct cfattach *);
278 static int
279 frob_cfattachvec(const struct cfattachinit *cfattachv,
280 	cfattach_fn att_do, cfattach_fn att_undo,
281 	const char *style, bool dopanic)
282 {
283 	const struct cfattachinit *cfai = NULL;
284 	void (*pr)(const char *, ...) __printflike(1, 2) =
285 	    dopanic ? panic : printf;
286 	int j = 0, error = 0, e2 __diagused;
287 
288 	for (cfai = &cfattachv[0]; cfai->cfai_name != NULL; cfai++) {
289 		for (j = 0; cfai->cfai_list[j] != NULL; j++) {
290 			if ((error = att_do(cfai->cfai_name,
291 			    cfai->cfai_list[j])) != 0) {
292 				pr("configure: attachment `%s' "
293 				    "of `%s' driver %s failed: %d",
294 				    cfai->cfai_list[j]->ca_name,
295 				    cfai->cfai_name, style, error);
296 				goto bad;
297 			}
298 		}
299 	}
300 
301 	KASSERT(error == 0);
302 	return 0;
303 
304  bad:
305 	/*
306 	 * Rollback in reverse order.  dunno if super-important, but
307 	 * do that anyway.  Although the code looks a little like
308 	 * someone did a little integration (in the math sense).
309 	 */
310 	printf("\n");
311 	if (cfai) {
312 		bool last;
313 
314 		for (last = false; last == false; ) {
315 			if (cfai == &cfattachv[0])
316 				last = true;
317 			for (j--; j >= 0; j--) {
318 				e2 = att_undo(cfai->cfai_name,
319 				    cfai->cfai_list[j]);
320 				KASSERT(e2 == 0);
321 			}
322 			if (!last) {
323 				cfai--;
324 				for (j = 0; cfai->cfai_list[j] != NULL; j++)
325 					;
326 			}
327 		}
328 	}
329 
330 	return error;
331 }
332 
333 /*
334  * Initialize the autoconfiguration data structures.  Normally this
335  * is done by configure(), but some platforms need to do this very
336  * early (to e.g. initialize the console).
337  */
338 void
339 config_init(void)
340 {
341 
342 	KASSERT(config_initialized == false);
343 
344 	mutex_init(&alldevs_mtx, MUTEX_DEFAULT, IPL_VM);
345 
346 	mutex_init(&config_misc_lock, MUTEX_DEFAULT, IPL_NONE);
347 	cv_init(&config_misc_cv, "cfgmisc");
348 
349 	callout_init(&config_twiddle_ch, CALLOUT_MPSAFE);
350 
351 	frob_cfdrivervec(cfdriver_list_initial,
352 	    config_cfdriver_attach, NULL, "bootstrap", true);
353 	frob_cfattachvec(cfattachinit,
354 	    config_cfattach_attach, NULL, "bootstrap", true);
355 
356 	initcftable.ct_cfdata = cfdata;
357 	TAILQ_INSERT_TAIL(&allcftables, &initcftable, ct_list);
358 
359 	config_initialized = true;
360 }
361 
362 /*
363  * Init or fini drivers and attachments.  Either all or none
364  * are processed (via rollback).  It would be nice if this were
365  * atomic to outside consumers, but with the current state of
366  * locking ...
367  */
368 int
369 config_init_component(struct cfdriver * const *cfdriverv,
370 	const struct cfattachinit *cfattachv, struct cfdata *cfdatav)
371 {
372 	int error;
373 
374 	if ((error = frob_cfdrivervec(cfdriverv,
375 	    config_cfdriver_attach, config_cfdriver_detach, "init", false))!= 0)
376 		return error;
377 	if ((error = frob_cfattachvec(cfattachv,
378 	    config_cfattach_attach, config_cfattach_detach,
379 	    "init", false)) != 0) {
380 		frob_cfdrivervec(cfdriverv,
381 	            config_cfdriver_detach, NULL, "init rollback", true);
382 		return error;
383 	}
384 	if ((error = config_cfdata_attach(cfdatav, 1)) != 0) {
385 		frob_cfattachvec(cfattachv,
386 		    config_cfattach_detach, NULL, "init rollback", true);
387 		frob_cfdrivervec(cfdriverv,
388 	            config_cfdriver_detach, NULL, "init rollback", true);
389 		return error;
390 	}
391 
392 	return 0;
393 }
394 
395 int
396 config_fini_component(struct cfdriver * const *cfdriverv,
397 	const struct cfattachinit *cfattachv, struct cfdata *cfdatav)
398 {
399 	int error;
400 
401 	if ((error = config_cfdata_detach(cfdatav)) != 0)
402 		return error;
403 	if ((error = frob_cfattachvec(cfattachv,
404 	    config_cfattach_detach, config_cfattach_attach,
405 	    "fini", false)) != 0) {
406 		if (config_cfdata_attach(cfdatav, 0) != 0)
407 			panic("config_cfdata fini rollback failed");
408 		return error;
409 	}
410 	if ((error = frob_cfdrivervec(cfdriverv,
411 	    config_cfdriver_detach, config_cfdriver_attach,
412 	    "fini", false)) != 0) {
413 		frob_cfattachvec(cfattachv,
414 	            config_cfattach_attach, NULL, "fini rollback", true);
415 		if (config_cfdata_attach(cfdatav, 0) != 0)
416 			panic("config_cfdata fini rollback failed");
417 		return error;
418 	}
419 
420 	return 0;
421 }
422 
423 void
424 config_init_mi(void)
425 {
426 
427 	if (!config_initialized)
428 		config_init();
429 
430 	sysctl_detach_setup(NULL);
431 }
432 
433 void
434 config_deferred(device_t dev)
435 {
436 	config_process_deferred(&deferred_config_queue, dev);
437 	config_process_deferred(&interrupt_config_queue, dev);
438 	config_process_deferred(&mountroot_config_queue, dev);
439 }
440 
441 static void
442 config_interrupts_thread(void *cookie)
443 {
444 	struct deferred_config *dc;
445 
446 	while ((dc = TAILQ_FIRST(&interrupt_config_queue)) != NULL) {
447 		TAILQ_REMOVE(&interrupt_config_queue, dc, dc_queue);
448 		(*dc->dc_func)(dc->dc_dev);
449 		config_pending_decr(dc->dc_dev);
450 		kmem_free(dc, sizeof(*dc));
451 	}
452 	kthread_exit(0);
453 }
454 
455 void
456 config_create_interruptthreads(void)
457 {
458 	int i;
459 
460 	for (i = 0; i < interrupt_config_threads; i++) {
461 		(void)kthread_create(PRI_NONE, 0, NULL,
462 		    config_interrupts_thread, NULL, NULL, "configintr");
463 	}
464 }
465 
466 static void
467 config_mountroot_thread(void *cookie)
468 {
469 	struct deferred_config *dc;
470 
471 	while ((dc = TAILQ_FIRST(&mountroot_config_queue)) != NULL) {
472 		TAILQ_REMOVE(&mountroot_config_queue, dc, dc_queue);
473 		(*dc->dc_func)(dc->dc_dev);
474 		kmem_free(dc, sizeof(*dc));
475 	}
476 	kthread_exit(0);
477 }
478 
479 void
480 config_create_mountrootthreads(void)
481 {
482 	int i;
483 
484 	if (!root_is_mounted)
485 		root_is_mounted = true;
486 
487 	mountroot_config_lwpids_size = sizeof(mountroot_config_lwpids) *
488 				       mountroot_config_threads;
489 	mountroot_config_lwpids = kmem_alloc(mountroot_config_lwpids_size,
490 					     KM_NOSLEEP);
491 	KASSERT(mountroot_config_lwpids);
492 	for (i = 0; i < mountroot_config_threads; i++) {
493 		mountroot_config_lwpids[i] = 0;
494 		(void)kthread_create(PRI_NONE, KTHREAD_MUSTJOIN, NULL,
495 				     config_mountroot_thread, NULL,
496 				     &mountroot_config_lwpids[i],
497 				     "configroot");
498 	}
499 }
500 
501 void
502 config_finalize_mountroot(void)
503 {
504 	int i, error;
505 
506 	for (i = 0; i < mountroot_config_threads; i++) {
507 		if (mountroot_config_lwpids[i] == 0)
508 			continue;
509 
510 		error = kthread_join(mountroot_config_lwpids[i]);
511 		if (error)
512 			printf("%s: thread %x joined with error %d\n",
513 			       __func__, i, error);
514 	}
515 	kmem_free(mountroot_config_lwpids, mountroot_config_lwpids_size);
516 }
517 
518 /*
519  * Announce device attach/detach to userland listeners.
520  */
521 
522 int
523 no_devmon_insert(const char *name, prop_dictionary_t p)
524 {
525 
526 	return ENODEV;
527 }
528 
529 static void
530 devmon_report_device(device_t dev, bool isattach)
531 {
532 	prop_dictionary_t ev;
533 	const char *parent;
534 	const char *what;
535 	device_t pdev = device_parent(dev);
536 
537 	/* If currently no drvctl device, just return */
538 	if (devmon_insert_vec == no_devmon_insert)
539 		return;
540 
541 	ev = prop_dictionary_create();
542 	if (ev == NULL)
543 		return;
544 
545 	what = (isattach ? "device-attach" : "device-detach");
546 	parent = (pdev == NULL ? "root" : device_xname(pdev));
547 	if (!prop_dictionary_set_cstring(ev, "device", device_xname(dev)) ||
548 	    !prop_dictionary_set_cstring(ev, "parent", parent)) {
549 		prop_object_release(ev);
550 		return;
551 	}
552 
553 	if ((*devmon_insert_vec)(what, ev) != 0)
554 		prop_object_release(ev);
555 }
556 
557 /*
558  * Add a cfdriver to the system.
559  */
560 int
561 config_cfdriver_attach(struct cfdriver *cd)
562 {
563 	struct cfdriver *lcd;
564 
565 	/* Make sure this driver isn't already in the system. */
566 	LIST_FOREACH(lcd, &allcfdrivers, cd_list) {
567 		if (STREQ(lcd->cd_name, cd->cd_name))
568 			return EEXIST;
569 	}
570 
571 	LIST_INIT(&cd->cd_attach);
572 	LIST_INSERT_HEAD(&allcfdrivers, cd, cd_list);
573 
574 	return 0;
575 }
576 
577 /*
578  * Remove a cfdriver from the system.
579  */
580 int
581 config_cfdriver_detach(struct cfdriver *cd)
582 {
583 	struct alldevs_foray af;
584 	int i, rc = 0;
585 
586 	config_alldevs_enter(&af);
587 	/* Make sure there are no active instances. */
588 	for (i = 0; i < cd->cd_ndevs; i++) {
589 		if (cd->cd_devs[i] != NULL) {
590 			rc = EBUSY;
591 			break;
592 		}
593 	}
594 	config_alldevs_exit(&af);
595 
596 	if (rc != 0)
597 		return rc;
598 
599 	/* ...and no attachments loaded. */
600 	if (LIST_EMPTY(&cd->cd_attach) == 0)
601 		return EBUSY;
602 
603 	LIST_REMOVE(cd, cd_list);
604 
605 	KASSERT(cd->cd_devs == NULL);
606 
607 	return 0;
608 }
609 
610 /*
611  * Look up a cfdriver by name.
612  */
613 struct cfdriver *
614 config_cfdriver_lookup(const char *name)
615 {
616 	struct cfdriver *cd;
617 
618 	LIST_FOREACH(cd, &allcfdrivers, cd_list) {
619 		if (STREQ(cd->cd_name, name))
620 			return cd;
621 	}
622 
623 	return NULL;
624 }
625 
626 /*
627  * Add a cfattach to the specified driver.
628  */
629 int
630 config_cfattach_attach(const char *driver, struct cfattach *ca)
631 {
632 	struct cfattach *lca;
633 	struct cfdriver *cd;
634 
635 	cd = config_cfdriver_lookup(driver);
636 	if (cd == NULL)
637 		return ESRCH;
638 
639 	/* Make sure this attachment isn't already on this driver. */
640 	LIST_FOREACH(lca, &cd->cd_attach, ca_list) {
641 		if (STREQ(lca->ca_name, ca->ca_name))
642 			return EEXIST;
643 	}
644 
645 	LIST_INSERT_HEAD(&cd->cd_attach, ca, ca_list);
646 
647 	return 0;
648 }
649 
650 /*
651  * Remove a cfattach from the specified driver.
652  */
653 int
654 config_cfattach_detach(const char *driver, struct cfattach *ca)
655 {
656 	struct alldevs_foray af;
657 	struct cfdriver *cd;
658 	device_t dev;
659 	int i, rc = 0;
660 
661 	cd = config_cfdriver_lookup(driver);
662 	if (cd == NULL)
663 		return ESRCH;
664 
665 	config_alldevs_enter(&af);
666 	/* Make sure there are no active instances. */
667 	for (i = 0; i < cd->cd_ndevs; i++) {
668 		if ((dev = cd->cd_devs[i]) == NULL)
669 			continue;
670 		if (dev->dv_cfattach == ca) {
671 			rc = EBUSY;
672 			break;
673 		}
674 	}
675 	config_alldevs_exit(&af);
676 
677 	if (rc != 0)
678 		return rc;
679 
680 	LIST_REMOVE(ca, ca_list);
681 
682 	return 0;
683 }
684 
685 /*
686  * Look up a cfattach by name.
687  */
688 static struct cfattach *
689 config_cfattach_lookup_cd(struct cfdriver *cd, const char *atname)
690 {
691 	struct cfattach *ca;
692 
693 	LIST_FOREACH(ca, &cd->cd_attach, ca_list) {
694 		if (STREQ(ca->ca_name, atname))
695 			return ca;
696 	}
697 
698 	return NULL;
699 }
700 
701 /*
702  * Look up a cfattach by driver/attachment name.
703  */
704 struct cfattach *
705 config_cfattach_lookup(const char *name, const char *atname)
706 {
707 	struct cfdriver *cd;
708 
709 	cd = config_cfdriver_lookup(name);
710 	if (cd == NULL)
711 		return NULL;
712 
713 	return config_cfattach_lookup_cd(cd, atname);
714 }
715 
716 /*
717  * Apply the matching function and choose the best.  This is used
718  * a few times and we want to keep the code small.
719  */
720 static void
721 mapply(struct matchinfo *m, cfdata_t cf)
722 {
723 	int pri;
724 
725 	if (m->fn != NULL) {
726 		pri = (*m->fn)(m->parent, cf, m->locs, m->aux);
727 	} else {
728 		pri = config_match(m->parent, cf, m->aux);
729 	}
730 	if (pri > m->pri) {
731 		m->match = cf;
732 		m->pri = pri;
733 	}
734 }
735 
736 int
737 config_stdsubmatch(device_t parent, cfdata_t cf, const int *locs, void *aux)
738 {
739 	const struct cfiattrdata *ci;
740 	const struct cflocdesc *cl;
741 	int nlocs, i;
742 
743 	ci = cfiattr_lookup(cfdata_ifattr(cf), parent->dv_cfdriver);
744 	KASSERT(ci);
745 	nlocs = ci->ci_loclen;
746 	KASSERT(!nlocs || locs);
747 	for (i = 0; i < nlocs; i++) {
748 		cl = &ci->ci_locdesc[i];
749 		if (cl->cld_defaultstr != NULL &&
750 		    cf->cf_loc[i] == cl->cld_default)
751 			continue;
752 		if (cf->cf_loc[i] == locs[i])
753 			continue;
754 		return 0;
755 	}
756 
757 	return config_match(parent, cf, aux);
758 }
759 
760 /*
761  * Helper function: check whether the driver supports the interface attribute
762  * and return its descriptor structure.
763  */
764 static const struct cfiattrdata *
765 cfdriver_get_iattr(const struct cfdriver *cd, const char *ia)
766 {
767 	const struct cfiattrdata * const *cpp;
768 
769 	if (cd->cd_attrs == NULL)
770 		return 0;
771 
772 	for (cpp = cd->cd_attrs; *cpp; cpp++) {
773 		if (STREQ((*cpp)->ci_name, ia)) {
774 			/* Match. */
775 			return *cpp;
776 		}
777 	}
778 	return 0;
779 }
780 
781 /*
782  * Lookup an interface attribute description by name.
783  * If the driver is given, consider only its supported attributes.
784  */
785 const struct cfiattrdata *
786 cfiattr_lookup(const char *name, const struct cfdriver *cd)
787 {
788 	const struct cfdriver *d;
789 	const struct cfiattrdata *ia;
790 
791 	if (cd)
792 		return cfdriver_get_iattr(cd, name);
793 
794 	LIST_FOREACH(d, &allcfdrivers, cd_list) {
795 		ia = cfdriver_get_iattr(d, name);
796 		if (ia)
797 			return ia;
798 	}
799 	return 0;
800 }
801 
802 /*
803  * Determine if `parent' is a potential parent for a device spec based
804  * on `cfp'.
805  */
806 static int
807 cfparent_match(const device_t parent, const struct cfparent *cfp)
808 {
809 	struct cfdriver *pcd;
810 
811 	/* We don't match root nodes here. */
812 	if (cfp == NULL)
813 		return 0;
814 
815 	pcd = parent->dv_cfdriver;
816 	KASSERT(pcd != NULL);
817 
818 	/*
819 	 * First, ensure this parent has the correct interface
820 	 * attribute.
821 	 */
822 	if (!cfdriver_get_iattr(pcd, cfp->cfp_iattr))
823 		return 0;
824 
825 	/*
826 	 * If no specific parent device instance was specified (i.e.
827 	 * we're attaching to the attribute only), we're done!
828 	 */
829 	if (cfp->cfp_parent == NULL)
830 		return 1;
831 
832 	/*
833 	 * Check the parent device's name.
834 	 */
835 	if (STREQ(pcd->cd_name, cfp->cfp_parent) == 0)
836 		return 0;	/* not the same parent */
837 
838 	/*
839 	 * Make sure the unit number matches.
840 	 */
841 	if (cfp->cfp_unit == DVUNIT_ANY ||	/* wildcard */
842 	    cfp->cfp_unit == parent->dv_unit)
843 		return 1;
844 
845 	/* Unit numbers don't match. */
846 	return 0;
847 }
848 
849 /*
850  * Helper for config_cfdata_attach(): check all devices whether it could be
851  * parent any attachment in the config data table passed, and rescan.
852  */
853 static void
854 rescan_with_cfdata(const struct cfdata *cf)
855 {
856 	device_t d;
857 	const struct cfdata *cf1;
858 	deviter_t di;
859 
860 
861 	/*
862 	 * "alldevs" is likely longer than a modules's cfdata, so make it
863 	 * the outer loop.
864 	 */
865 	for (d = deviter_first(&di, 0); d != NULL; d = deviter_next(&di)) {
866 
867 		if (!(d->dv_cfattach->ca_rescan))
868 			continue;
869 
870 		for (cf1 = cf; cf1->cf_name; cf1++) {
871 
872 			if (!cfparent_match(d, cf1->cf_pspec))
873 				continue;
874 
875 			(*d->dv_cfattach->ca_rescan)(d,
876 				cfdata_ifattr(cf1), cf1->cf_loc);
877 
878 			config_deferred(d);
879 		}
880 	}
881 	deviter_release(&di);
882 }
883 
884 /*
885  * Attach a supplemental config data table and rescan potential
886  * parent devices if required.
887  */
888 int
889 config_cfdata_attach(cfdata_t cf, int scannow)
890 {
891 	struct cftable *ct;
892 
893 	ct = kmem_alloc(sizeof(*ct), KM_SLEEP);
894 	ct->ct_cfdata = cf;
895 	TAILQ_INSERT_TAIL(&allcftables, ct, ct_list);
896 
897 	if (scannow)
898 		rescan_with_cfdata(cf);
899 
900 	return 0;
901 }
902 
903 /*
904  * Helper for config_cfdata_detach: check whether a device is
905  * found through any attachment in the config data table.
906  */
907 static int
908 dev_in_cfdata(device_t d, cfdata_t cf)
909 {
910 	const struct cfdata *cf1;
911 
912 	for (cf1 = cf; cf1->cf_name; cf1++)
913 		if (d->dv_cfdata == cf1)
914 			return 1;
915 
916 	return 0;
917 }
918 
919 /*
920  * Detach a supplemental config data table. Detach all devices found
921  * through that table (and thus keeping references to it) before.
922  */
923 int
924 config_cfdata_detach(cfdata_t cf)
925 {
926 	device_t d;
927 	int error = 0;
928 	struct cftable *ct;
929 	deviter_t di;
930 
931 	for (d = deviter_first(&di, DEVITER_F_RW); d != NULL;
932 	     d = deviter_next(&di)) {
933 		if (!dev_in_cfdata(d, cf))
934 			continue;
935 		if ((error = config_detach(d, 0)) != 0)
936 			break;
937 	}
938 	deviter_release(&di);
939 	if (error) {
940 		aprint_error_dev(d, "unable to detach instance\n");
941 		return error;
942 	}
943 
944 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
945 		if (ct->ct_cfdata == cf) {
946 			TAILQ_REMOVE(&allcftables, ct, ct_list);
947 			kmem_free(ct, sizeof(*ct));
948 			return 0;
949 		}
950 	}
951 
952 	/* not found -- shouldn't happen */
953 	return EINVAL;
954 }
955 
956 /*
957  * Invoke the "match" routine for a cfdata entry on behalf of
958  * an external caller, usually a "submatch" routine.
959  */
960 int
961 config_match(device_t parent, cfdata_t cf, void *aux)
962 {
963 	struct cfattach *ca;
964 
965 	ca = config_cfattach_lookup(cf->cf_name, cf->cf_atname);
966 	if (ca == NULL) {
967 		/* No attachment for this entry, oh well. */
968 		return 0;
969 	}
970 
971 	return (*ca->ca_match)(parent, cf, aux);
972 }
973 
974 /*
975  * Iterate over all potential children of some device, calling the given
976  * function (default being the child's match function) for each one.
977  * Nonzero returns are matches; the highest value returned is considered
978  * the best match.  Return the `found child' if we got a match, or NULL
979  * otherwise.  The `aux' pointer is simply passed on through.
980  *
981  * Note that this function is designed so that it can be used to apply
982  * an arbitrary function to all potential children (its return value
983  * can be ignored).
984  */
985 cfdata_t
986 config_search_loc(cfsubmatch_t fn, device_t parent,
987 		  const char *ifattr, const int *locs, void *aux)
988 {
989 	struct cftable *ct;
990 	cfdata_t cf;
991 	struct matchinfo m;
992 
993 	KASSERT(config_initialized);
994 	KASSERT(!ifattr || cfdriver_get_iattr(parent->dv_cfdriver, ifattr));
995 
996 	m.fn = fn;
997 	m.parent = parent;
998 	m.locs = locs;
999 	m.aux = aux;
1000 	m.match = NULL;
1001 	m.pri = 0;
1002 
1003 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
1004 		for (cf = ct->ct_cfdata; cf->cf_name; cf++) {
1005 
1006 			/* We don't match root nodes here. */
1007 			if (!cf->cf_pspec)
1008 				continue;
1009 
1010 			/*
1011 			 * Skip cf if no longer eligible, otherwise scan
1012 			 * through parents for one matching `parent', and
1013 			 * try match function.
1014 			 */
1015 			if (cf->cf_fstate == FSTATE_FOUND)
1016 				continue;
1017 			if (cf->cf_fstate == FSTATE_DNOTFOUND ||
1018 			    cf->cf_fstate == FSTATE_DSTAR)
1019 				continue;
1020 
1021 			/*
1022 			 * If an interface attribute was specified,
1023 			 * consider only children which attach to
1024 			 * that attribute.
1025 			 */
1026 			if (ifattr && !STREQ(ifattr, cfdata_ifattr(cf)))
1027 				continue;
1028 
1029 			if (cfparent_match(parent, cf->cf_pspec))
1030 				mapply(&m, cf);
1031 		}
1032 	}
1033 	return m.match;
1034 }
1035 
1036 cfdata_t
1037 config_search_ia(cfsubmatch_t fn, device_t parent, const char *ifattr,
1038     void *aux)
1039 {
1040 
1041 	return config_search_loc(fn, parent, ifattr, NULL, aux);
1042 }
1043 
1044 /*
1045  * Find the given root device.
1046  * This is much like config_search, but there is no parent.
1047  * Don't bother with multiple cfdata tables; the root node
1048  * must always be in the initial table.
1049  */
1050 cfdata_t
1051 config_rootsearch(cfsubmatch_t fn, const char *rootname, void *aux)
1052 {
1053 	cfdata_t cf;
1054 	const short *p;
1055 	struct matchinfo m;
1056 
1057 	m.fn = fn;
1058 	m.parent = ROOT;
1059 	m.aux = aux;
1060 	m.match = NULL;
1061 	m.pri = 0;
1062 	m.locs = 0;
1063 	/*
1064 	 * Look at root entries for matching name.  We do not bother
1065 	 * with found-state here since only one root should ever be
1066 	 * searched (and it must be done first).
1067 	 */
1068 	for (p = cfroots; *p >= 0; p++) {
1069 		cf = &cfdata[*p];
1070 		if (strcmp(cf->cf_name, rootname) == 0)
1071 			mapply(&m, cf);
1072 	}
1073 	return m.match;
1074 }
1075 
1076 static const char * const msgs[3] = { "", " not configured\n", " unsupported\n" };
1077 
1078 /*
1079  * The given `aux' argument describes a device that has been found
1080  * on the given parent, but not necessarily configured.  Locate the
1081  * configuration data for that device (using the submatch function
1082  * provided, or using candidates' cd_match configuration driver
1083  * functions) and attach it, and return its device_t.  If the device was
1084  * not configured, call the given `print' function and return NULL.
1085  */
1086 device_t
1087 config_found_sm_loc(device_t parent,
1088 		const char *ifattr, const int *locs, void *aux,
1089 		cfprint_t print, cfsubmatch_t submatch)
1090 {
1091 	cfdata_t cf;
1092 
1093 	if ((cf = config_search_loc(submatch, parent, ifattr, locs, aux)))
1094 		return(config_attach_loc(parent, cf, locs, aux, print));
1095 	if (print) {
1096 		if (config_do_twiddle && cold)
1097 			twiddle();
1098 		aprint_normal("%s", msgs[(*print)(aux, device_xname(parent))]);
1099 	}
1100 
1101 	/*
1102 	 * This has the effect of mixing in a single timestamp to the
1103 	 * entropy pool.  Experiments indicate the estimator will almost
1104 	 * always attribute one bit of entropy to this sample; analysis
1105 	 * of device attach/detach timestamps on FreeBSD indicates 4
1106 	 * bits of entropy/sample so this seems appropriately conservative.
1107 	 */
1108 	rnd_add_uint32(&rnd_autoconf_source, 0);
1109 	return NULL;
1110 }
1111 
1112 device_t
1113 config_found_ia(device_t parent, const char *ifattr, void *aux,
1114     cfprint_t print)
1115 {
1116 
1117 	return config_found_sm_loc(parent, ifattr, NULL, aux, print, NULL);
1118 }
1119 
1120 device_t
1121 config_found(device_t parent, void *aux, cfprint_t print)
1122 {
1123 
1124 	return config_found_sm_loc(parent, NULL, NULL, aux, print, NULL);
1125 }
1126 
1127 /*
1128  * As above, but for root devices.
1129  */
1130 device_t
1131 config_rootfound(const char *rootname, void *aux)
1132 {
1133 	cfdata_t cf;
1134 
1135 	if ((cf = config_rootsearch(NULL, rootname, aux)) != NULL)
1136 		return config_attach(ROOT, cf, aux, NULL);
1137 	aprint_error("root device %s not configured\n", rootname);
1138 	return NULL;
1139 }
1140 
1141 /* just like sprintf(buf, "%d") except that it works from the end */
1142 static char *
1143 number(char *ep, int n)
1144 {
1145 
1146 	*--ep = 0;
1147 	while (n >= 10) {
1148 		*--ep = (n % 10) + '0';
1149 		n /= 10;
1150 	}
1151 	*--ep = n + '0';
1152 	return ep;
1153 }
1154 
1155 /*
1156  * Expand the size of the cd_devs array if necessary.
1157  *
1158  * The caller must hold alldevs_mtx. config_makeroom() may release and
1159  * re-acquire alldevs_mtx, so callers should re-check conditions such
1160  * as alldevs_nwrite == 0 and alldevs_nread == 0 when config_makeroom()
1161  * returns.
1162  */
1163 static void
1164 config_makeroom(int n, struct cfdriver *cd)
1165 {
1166 	int ondevs, nndevs;
1167 	device_t *osp, *nsp;
1168 
1169 	alldevs_nwrite++;
1170 
1171 	for (nndevs = MAX(4, cd->cd_ndevs); nndevs <= n; nndevs += nndevs)
1172 		;
1173 
1174 	while (n >= cd->cd_ndevs) {
1175 		/*
1176 		 * Need to expand the array.
1177 		 */
1178 		ondevs = cd->cd_ndevs;
1179 		osp = cd->cd_devs;
1180 
1181 		/* Release alldevs_mtx around allocation, which may
1182 		 * sleep.
1183 		 */
1184 		mutex_exit(&alldevs_mtx);
1185 		nsp = kmem_alloc(sizeof(device_t[nndevs]), KM_SLEEP);
1186 		if (nsp == NULL)
1187 			panic("%s: could not expand cd_devs", __func__);
1188 		mutex_enter(&alldevs_mtx);
1189 
1190 		/* If another thread moved the array while we did
1191 		 * not hold alldevs_mtx, try again.
1192 		 */
1193 		if (cd->cd_devs != osp) {
1194 			mutex_exit(&alldevs_mtx);
1195 			kmem_free(nsp, sizeof(device_t[nndevs]));
1196 			mutex_enter(&alldevs_mtx);
1197 			continue;
1198 		}
1199 
1200 		memset(nsp + ondevs, 0, sizeof(device_t[nndevs - ondevs]));
1201 		if (ondevs != 0)
1202 			memcpy(nsp, cd->cd_devs, sizeof(device_t[ondevs]));
1203 
1204 		cd->cd_ndevs = nndevs;
1205 		cd->cd_devs = nsp;
1206 		if (ondevs != 0) {
1207 			mutex_exit(&alldevs_mtx);
1208 			kmem_free(osp, sizeof(device_t[ondevs]));
1209 			mutex_enter(&alldevs_mtx);
1210 		}
1211 	}
1212 	alldevs_nwrite--;
1213 }
1214 
1215 /*
1216  * Put dev into the devices list.
1217  */
1218 static void
1219 config_devlink(device_t dev)
1220 {
1221 
1222 	mutex_enter(&alldevs_mtx);
1223 
1224 	KASSERT(device_cfdriver(dev)->cd_devs[dev->dv_unit] == dev);
1225 
1226 	dev->dv_add_gen = alldevs_gen;
1227 	/* It is safe to add a device to the tail of the list while
1228 	 * readers and writers are in the list.
1229 	 */
1230 	TAILQ_INSERT_TAIL(&alldevs, dev, dv_list);
1231 	mutex_exit(&alldevs_mtx);
1232 }
1233 
1234 static void
1235 config_devfree(device_t dev)
1236 {
1237 	int priv = (dev->dv_flags & DVF_PRIV_ALLOC);
1238 
1239 	if (dev->dv_cfattach->ca_devsize > 0)
1240 		kmem_free(dev->dv_private, dev->dv_cfattach->ca_devsize);
1241 	if (priv)
1242 		kmem_free(dev, sizeof(*dev));
1243 }
1244 
1245 /*
1246  * Caller must hold alldevs_mtx.
1247  */
1248 static void
1249 config_devunlink(device_t dev, struct devicelist *garbage)
1250 {
1251 	struct device_garbage *dg = &dev->dv_garbage;
1252 	cfdriver_t cd = device_cfdriver(dev);
1253 	int i;
1254 
1255 	KASSERT(mutex_owned(&alldevs_mtx));
1256 
1257  	/* Unlink from device list.  Link to garbage list. */
1258 	TAILQ_REMOVE(&alldevs, dev, dv_list);
1259 	TAILQ_INSERT_TAIL(garbage, dev, dv_list);
1260 
1261 	/* Remove from cfdriver's array. */
1262 	cd->cd_devs[dev->dv_unit] = NULL;
1263 
1264 	/*
1265 	 * If the device now has no units in use, unlink its softc array.
1266 	 */
1267 	for (i = 0; i < cd->cd_ndevs; i++) {
1268 		if (cd->cd_devs[i] != NULL)
1269 			break;
1270 	}
1271 	/* Nothing found.  Unlink, now.  Deallocate, later. */
1272 	if (i == cd->cd_ndevs) {
1273 		dg->dg_ndevs = cd->cd_ndevs;
1274 		dg->dg_devs = cd->cd_devs;
1275 		cd->cd_devs = NULL;
1276 		cd->cd_ndevs = 0;
1277 	}
1278 }
1279 
1280 static void
1281 config_devdelete(device_t dev)
1282 {
1283 	struct device_garbage *dg = &dev->dv_garbage;
1284 	device_lock_t dvl = device_getlock(dev);
1285 
1286 	if (dg->dg_devs != NULL)
1287 		kmem_free(dg->dg_devs, sizeof(device_t[dg->dg_ndevs]));
1288 
1289 	cv_destroy(&dvl->dvl_cv);
1290 	mutex_destroy(&dvl->dvl_mtx);
1291 
1292 	KASSERT(dev->dv_properties != NULL);
1293 	prop_object_release(dev->dv_properties);
1294 
1295 	if (dev->dv_activity_handlers)
1296 		panic("%s with registered handlers", __func__);
1297 
1298 	if (dev->dv_locators) {
1299 		size_t amount = *--dev->dv_locators;
1300 		kmem_free(dev->dv_locators, amount);
1301 	}
1302 
1303 	config_devfree(dev);
1304 }
1305 
1306 static int
1307 config_unit_nextfree(cfdriver_t cd, cfdata_t cf)
1308 {
1309 	int unit;
1310 
1311 	if (cf->cf_fstate == FSTATE_STAR) {
1312 		for (unit = cf->cf_unit; unit < cd->cd_ndevs; unit++)
1313 			if (cd->cd_devs[unit] == NULL)
1314 				break;
1315 		/*
1316 		 * unit is now the unit of the first NULL device pointer,
1317 		 * or max(cd->cd_ndevs,cf->cf_unit).
1318 		 */
1319 	} else {
1320 		unit = cf->cf_unit;
1321 		if (unit < cd->cd_ndevs && cd->cd_devs[unit] != NULL)
1322 			unit = -1;
1323 	}
1324 	return unit;
1325 }
1326 
1327 static int
1328 config_unit_alloc(device_t dev, cfdriver_t cd, cfdata_t cf)
1329 {
1330 	struct alldevs_foray af;
1331 	int unit;
1332 
1333 	config_alldevs_enter(&af);
1334 	for (;;) {
1335 		unit = config_unit_nextfree(cd, cf);
1336 		if (unit == -1)
1337 			break;
1338 		if (unit < cd->cd_ndevs) {
1339 			cd->cd_devs[unit] = dev;
1340 			dev->dv_unit = unit;
1341 			break;
1342 		}
1343 		config_makeroom(unit, cd);
1344 	}
1345 	config_alldevs_exit(&af);
1346 
1347 	return unit;
1348 }
1349 
1350 static device_t
1351 config_devalloc(const device_t parent, const cfdata_t cf, const int *locs)
1352 {
1353 	cfdriver_t cd;
1354 	cfattach_t ca;
1355 	size_t lname, lunit;
1356 	const char *xunit;
1357 	int myunit;
1358 	char num[10];
1359 	device_t dev;
1360 	void *dev_private;
1361 	const struct cfiattrdata *ia;
1362 	device_lock_t dvl;
1363 
1364 	cd = config_cfdriver_lookup(cf->cf_name);
1365 	if (cd == NULL)
1366 		return NULL;
1367 
1368 	ca = config_cfattach_lookup_cd(cd, cf->cf_atname);
1369 	if (ca == NULL)
1370 		return NULL;
1371 
1372 	if ((ca->ca_flags & DVF_PRIV_ALLOC) == 0 &&
1373 	    ca->ca_devsize < sizeof(struct device))
1374 		panic("config_devalloc: %s (%zu < %zu)", cf->cf_atname,
1375 		    ca->ca_devsize, sizeof(struct device));
1376 
1377 	/* get memory for all device vars */
1378 	KASSERT((ca->ca_flags & DVF_PRIV_ALLOC) || ca->ca_devsize >= sizeof(struct device));
1379 	if (ca->ca_devsize > 0) {
1380 		dev_private = kmem_zalloc(ca->ca_devsize, KM_SLEEP);
1381 		if (dev_private == NULL)
1382 			panic("config_devalloc: memory allocation for device softc failed");
1383 	} else {
1384 		KASSERT(ca->ca_flags & DVF_PRIV_ALLOC);
1385 		dev_private = NULL;
1386 	}
1387 
1388 	if ((ca->ca_flags & DVF_PRIV_ALLOC) != 0) {
1389 		dev = kmem_zalloc(sizeof(*dev), KM_SLEEP);
1390 	} else {
1391 		dev = dev_private;
1392 #ifdef DIAGNOSTIC
1393 		printf("%s has not been converted to device_t\n", cd->cd_name);
1394 #endif
1395 	}
1396 	if (dev == NULL)
1397 		panic("config_devalloc: memory allocation for device_t failed");
1398 
1399 	dev->dv_class = cd->cd_class;
1400 	dev->dv_cfdata = cf;
1401 	dev->dv_cfdriver = cd;
1402 	dev->dv_cfattach = ca;
1403 	dev->dv_activity_count = 0;
1404 	dev->dv_activity_handlers = NULL;
1405 	dev->dv_private = dev_private;
1406 	dev->dv_flags = ca->ca_flags;	/* inherit flags from class */
1407 
1408 	myunit = config_unit_alloc(dev, cd, cf);
1409 	if (myunit == -1) {
1410 		config_devfree(dev);
1411 		return NULL;
1412 	}
1413 
1414 	/* compute length of name and decimal expansion of unit number */
1415 	lname = strlen(cd->cd_name);
1416 	xunit = number(&num[sizeof(num)], myunit);
1417 	lunit = &num[sizeof(num)] - xunit;
1418 	if (lname + lunit > sizeof(dev->dv_xname))
1419 		panic("config_devalloc: device name too long");
1420 
1421 	dvl = device_getlock(dev);
1422 
1423 	mutex_init(&dvl->dvl_mtx, MUTEX_DEFAULT, IPL_NONE);
1424 	cv_init(&dvl->dvl_cv, "pmfsusp");
1425 
1426 	memcpy(dev->dv_xname, cd->cd_name, lname);
1427 	memcpy(dev->dv_xname + lname, xunit, lunit);
1428 	dev->dv_parent = parent;
1429 	if (parent != NULL)
1430 		dev->dv_depth = parent->dv_depth + 1;
1431 	else
1432 		dev->dv_depth = 0;
1433 	dev->dv_flags |= DVF_ACTIVE;	/* always initially active */
1434 	if (locs) {
1435 		KASSERT(parent); /* no locators at root */
1436 		ia = cfiattr_lookup(cfdata_ifattr(cf), parent->dv_cfdriver);
1437 		dev->dv_locators =
1438 		    kmem_alloc(sizeof(int [ia->ci_loclen + 1]), KM_SLEEP);
1439 		*dev->dv_locators++ = sizeof(int [ia->ci_loclen + 1]);
1440 		memcpy(dev->dv_locators, locs, sizeof(int [ia->ci_loclen]));
1441 	}
1442 	dev->dv_properties = prop_dictionary_create();
1443 	KASSERT(dev->dv_properties != NULL);
1444 
1445 	prop_dictionary_set_cstring_nocopy(dev->dv_properties,
1446 	    "device-driver", dev->dv_cfdriver->cd_name);
1447 	prop_dictionary_set_uint16(dev->dv_properties,
1448 	    "device-unit", dev->dv_unit);
1449 	if (parent != NULL) {
1450 		prop_dictionary_set_cstring(dev->dv_properties,
1451 		    "device-parent", device_xname(parent));
1452 	}
1453 
1454 	if (dev->dv_cfdriver->cd_attrs != NULL)
1455 		config_add_attrib_dict(dev);
1456 
1457 	return dev;
1458 }
1459 
1460 /*
1461  * Create an array of device attach attributes and add it
1462  * to the device's dv_properties dictionary.
1463  *
1464  * <key>interface-attributes</key>
1465  * <array>
1466  *    <dict>
1467  *       <key>attribute-name</key>
1468  *       <string>foo</string>
1469  *       <key>locators</key>
1470  *       <array>
1471  *          <dict>
1472  *             <key>loc-name</key>
1473  *             <string>foo-loc1</string>
1474  *          </dict>
1475  *          <dict>
1476  *             <key>loc-name</key>
1477  *             <string>foo-loc2</string>
1478  *             <key>default</key>
1479  *             <string>foo-loc2-default</string>
1480  *          </dict>
1481  *          ...
1482  *       </array>
1483  *    </dict>
1484  *    ...
1485  * </array>
1486  */
1487 
1488 static void
1489 config_add_attrib_dict(device_t dev)
1490 {
1491 	int i, j;
1492 	const struct cfiattrdata *ci;
1493 	prop_dictionary_t attr_dict, loc_dict;
1494 	prop_array_t attr_array, loc_array;
1495 
1496 	if ((attr_array = prop_array_create()) == NULL)
1497 		return;
1498 
1499 	for (i = 0; ; i++) {
1500 		if ((ci = dev->dv_cfdriver->cd_attrs[i]) == NULL)
1501 			break;
1502 		if ((attr_dict = prop_dictionary_create()) == NULL)
1503 			break;
1504 		prop_dictionary_set_cstring_nocopy(attr_dict, "attribute-name",
1505 		    ci->ci_name);
1506 
1507 		/* Create an array of the locator names and defaults */
1508 
1509 		if (ci->ci_loclen != 0 &&
1510 		    (loc_array = prop_array_create()) != NULL) {
1511 			for (j = 0; j < ci->ci_loclen; j++) {
1512 				loc_dict = prop_dictionary_create();
1513 				if (loc_dict == NULL)
1514 					continue;
1515 				prop_dictionary_set_cstring_nocopy(loc_dict,
1516 				    "loc-name", ci->ci_locdesc[j].cld_name);
1517 				if (ci->ci_locdesc[j].cld_defaultstr != NULL)
1518 					prop_dictionary_set_cstring_nocopy(
1519 					    loc_dict, "default",
1520 					    ci->ci_locdesc[j].cld_defaultstr);
1521 				prop_array_set(loc_array, j, loc_dict);
1522 				prop_object_release(loc_dict);
1523 			}
1524 			prop_dictionary_set_and_rel(attr_dict, "locators",
1525 			    loc_array);
1526 		}
1527 		prop_array_add(attr_array, attr_dict);
1528 		prop_object_release(attr_dict);
1529 	}
1530 	if (i == 0)
1531 		prop_object_release(attr_array);
1532 	else
1533 		prop_dictionary_set_and_rel(dev->dv_properties,
1534 		    "interface-attributes", attr_array);
1535 
1536 	return;
1537 }
1538 
1539 /*
1540  * Attach a found device.
1541  */
1542 device_t
1543 config_attach_loc(device_t parent, cfdata_t cf,
1544 	const int *locs, void *aux, cfprint_t print)
1545 {
1546 	device_t dev;
1547 	struct cftable *ct;
1548 	const char *drvname;
1549 
1550 	dev = config_devalloc(parent, cf, locs);
1551 	if (!dev)
1552 		panic("config_attach: allocation of device softc failed");
1553 
1554 	/* XXX redundant - see below? */
1555 	if (cf->cf_fstate != FSTATE_STAR) {
1556 		KASSERT(cf->cf_fstate == FSTATE_NOTFOUND);
1557 		cf->cf_fstate = FSTATE_FOUND;
1558 	}
1559 
1560 	config_devlink(dev);
1561 
1562 	if (config_do_twiddle && cold)
1563 		twiddle();
1564 	else
1565 		aprint_naive("Found ");
1566 	/*
1567 	 * We want the next two printfs for normal, verbose, and quiet,
1568 	 * but not silent (in which case, we're twiddling, instead).
1569 	 */
1570 	if (parent == ROOT) {
1571 		aprint_naive("%s (root)", device_xname(dev));
1572 		aprint_normal("%s (root)", device_xname(dev));
1573 	} else {
1574 		aprint_naive("%s at %s", device_xname(dev), device_xname(parent));
1575 		aprint_normal("%s at %s", device_xname(dev), device_xname(parent));
1576 		if (print)
1577 			(void) (*print)(aux, NULL);
1578 	}
1579 
1580 	/*
1581 	 * Before attaching, clobber any unfound devices that are
1582 	 * otherwise identical.
1583 	 * XXX code above is redundant?
1584 	 */
1585 	drvname = dev->dv_cfdriver->cd_name;
1586 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
1587 		for (cf = ct->ct_cfdata; cf->cf_name; cf++) {
1588 			if (STREQ(cf->cf_name, drvname) &&
1589 			    cf->cf_unit == dev->dv_unit) {
1590 				if (cf->cf_fstate == FSTATE_NOTFOUND)
1591 					cf->cf_fstate = FSTATE_FOUND;
1592 			}
1593 		}
1594 	}
1595 	device_register(dev, aux);
1596 
1597 	/* Let userland know */
1598 	devmon_report_device(dev, true);
1599 
1600 	(*dev->dv_cfattach->ca_attach)(parent, dev, aux);
1601 
1602 	if (!device_pmf_is_registered(dev))
1603 		aprint_debug_dev(dev, "WARNING: power management not supported\n");
1604 
1605 	config_process_deferred(&deferred_config_queue, dev);
1606 
1607 	device_register_post_config(dev, aux);
1608 	return dev;
1609 }
1610 
1611 device_t
1612 config_attach(device_t parent, cfdata_t cf, void *aux, cfprint_t print)
1613 {
1614 
1615 	return config_attach_loc(parent, cf, NULL, aux, print);
1616 }
1617 
1618 /*
1619  * As above, but for pseudo-devices.  Pseudo-devices attached in this
1620  * way are silently inserted into the device tree, and their children
1621  * attached.
1622  *
1623  * Note that because pseudo-devices are attached silently, any information
1624  * the attach routine wishes to print should be prefixed with the device
1625  * name by the attach routine.
1626  */
1627 device_t
1628 config_attach_pseudo(cfdata_t cf)
1629 {
1630 	device_t dev;
1631 
1632 	dev = config_devalloc(ROOT, cf, NULL);
1633 	if (!dev)
1634 		return NULL;
1635 
1636 	/* XXX mark busy in cfdata */
1637 
1638 	if (cf->cf_fstate != FSTATE_STAR) {
1639 		KASSERT(cf->cf_fstate == FSTATE_NOTFOUND);
1640 		cf->cf_fstate = FSTATE_FOUND;
1641 	}
1642 
1643 	config_devlink(dev);
1644 
1645 #if 0	/* XXXJRT not yet */
1646 	device_register(dev, NULL);	/* like a root node */
1647 #endif
1648 
1649 	/* Let userland know */
1650 	devmon_report_device(dev, true);
1651 
1652 	(*dev->dv_cfattach->ca_attach)(ROOT, dev, NULL);
1653 
1654 	config_process_deferred(&deferred_config_queue, dev);
1655 	return dev;
1656 }
1657 
1658 /*
1659  * Caller must hold alldevs_mtx.
1660  */
1661 static void
1662 config_collect_garbage(struct devicelist *garbage)
1663 {
1664 	device_t dv;
1665 
1666 	KASSERT(!cpu_intr_p());
1667 	KASSERT(!cpu_softintr_p());
1668 	KASSERT(mutex_owned(&alldevs_mtx));
1669 
1670 	while (alldevs_nwrite == 0 && alldevs_nread == 0 && alldevs_garbage) {
1671 		TAILQ_FOREACH(dv, &alldevs, dv_list) {
1672 			if (dv->dv_del_gen != 0)
1673 				break;
1674 		}
1675 		if (dv == NULL) {
1676 			alldevs_garbage = false;
1677 			break;
1678 		}
1679 		config_devunlink(dv, garbage);
1680 	}
1681 	KASSERT(mutex_owned(&alldevs_mtx));
1682 }
1683 
1684 static void
1685 config_dump_garbage(struct devicelist *garbage)
1686 {
1687 	device_t dv;
1688 
1689 	while ((dv = TAILQ_FIRST(garbage)) != NULL) {
1690 		TAILQ_REMOVE(garbage, dv, dv_list);
1691 		config_devdelete(dv);
1692 	}
1693 }
1694 
1695 /*
1696  * Detach a device.  Optionally forced (e.g. because of hardware
1697  * removal) and quiet.  Returns zero if successful, non-zero
1698  * (an error code) otherwise.
1699  *
1700  * Note that this code wants to be run from a process context, so
1701  * that the detach can sleep to allow processes which have a device
1702  * open to run and unwind their stacks.
1703  */
1704 int
1705 config_detach(device_t dev, int flags)
1706 {
1707 	struct alldevs_foray af;
1708 	struct cftable *ct;
1709 	cfdata_t cf;
1710 	const struct cfattach *ca;
1711 	struct cfdriver *cd;
1712 #ifdef DIAGNOSTIC
1713 	device_t d;
1714 #endif
1715 	int rv = 0;
1716 
1717 #ifdef DIAGNOSTIC
1718 	cf = dev->dv_cfdata;
1719 	if (cf != NULL && cf->cf_fstate != FSTATE_FOUND &&
1720 	    cf->cf_fstate != FSTATE_STAR)
1721 		panic("config_detach: %s: bad device fstate %d",
1722 		    device_xname(dev), cf ? cf->cf_fstate : -1);
1723 #endif
1724 	cd = dev->dv_cfdriver;
1725 	KASSERT(cd != NULL);
1726 
1727 	ca = dev->dv_cfattach;
1728 	KASSERT(ca != NULL);
1729 
1730 	mutex_enter(&alldevs_mtx);
1731 	if (dev->dv_del_gen != 0) {
1732 		mutex_exit(&alldevs_mtx);
1733 #ifdef DIAGNOSTIC
1734 		printf("%s: %s is already detached\n", __func__,
1735 		    device_xname(dev));
1736 #endif /* DIAGNOSTIC */
1737 		return ENOENT;
1738 	}
1739 	alldevs_nwrite++;
1740 	mutex_exit(&alldevs_mtx);
1741 
1742 	if (!detachall &&
1743 	    (flags & (DETACH_SHUTDOWN|DETACH_FORCE)) == DETACH_SHUTDOWN &&
1744 	    (dev->dv_flags & DVF_DETACH_SHUTDOWN) == 0) {
1745 		rv = EOPNOTSUPP;
1746 	} else if (ca->ca_detach != NULL) {
1747 		rv = (*ca->ca_detach)(dev, flags);
1748 	} else
1749 		rv = EOPNOTSUPP;
1750 
1751 	/*
1752 	 * If it was not possible to detach the device, then we either
1753 	 * panic() (for the forced but failed case), or return an error.
1754 	 *
1755 	 * If it was possible to detach the device, ensure that the
1756 	 * device is deactivated.
1757 	 */
1758 	if (rv == 0)
1759 		dev->dv_flags &= ~DVF_ACTIVE;
1760 	else if ((flags & DETACH_FORCE) == 0)
1761 		goto out;
1762 	else {
1763 		panic("config_detach: forced detach of %s failed (%d)",
1764 		    device_xname(dev), rv);
1765 	}
1766 
1767 	/*
1768 	 * The device has now been successfully detached.
1769 	 */
1770 
1771 	/* Let userland know */
1772 	devmon_report_device(dev, false);
1773 
1774 #ifdef DIAGNOSTIC
1775 	/*
1776 	 * Sanity: If you're successfully detached, you should have no
1777 	 * children.  (Note that because children must be attached
1778 	 * after parents, we only need to search the latter part of
1779 	 * the list.)
1780 	 */
1781 	for (d = TAILQ_NEXT(dev, dv_list); d != NULL;
1782 	    d = TAILQ_NEXT(d, dv_list)) {
1783 		if (d->dv_parent == dev && d->dv_del_gen == 0) {
1784 			printf("config_detach: detached device %s"
1785 			    " has children %s\n", device_xname(dev), device_xname(d));
1786 			panic("config_detach");
1787 		}
1788 	}
1789 #endif
1790 
1791 	/* notify the parent that the child is gone */
1792 	if (dev->dv_parent) {
1793 		device_t p = dev->dv_parent;
1794 		if (p->dv_cfattach->ca_childdetached)
1795 			(*p->dv_cfattach->ca_childdetached)(p, dev);
1796 	}
1797 
1798 	/*
1799 	 * Mark cfdata to show that the unit can be reused, if possible.
1800 	 */
1801 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
1802 		for (cf = ct->ct_cfdata; cf->cf_name; cf++) {
1803 			if (STREQ(cf->cf_name, cd->cd_name)) {
1804 				if (cf->cf_fstate == FSTATE_FOUND &&
1805 				    cf->cf_unit == dev->dv_unit)
1806 					cf->cf_fstate = FSTATE_NOTFOUND;
1807 			}
1808 		}
1809 	}
1810 
1811 	if (dev->dv_cfdata != NULL && (flags & DETACH_QUIET) == 0)
1812 		aprint_normal_dev(dev, "detached\n");
1813 
1814 out:
1815 	config_alldevs_enter(&af);
1816 	KASSERT(alldevs_nwrite != 0);
1817 	--alldevs_nwrite;
1818 	if (rv == 0 && dev->dv_del_gen == 0) {
1819 		if (alldevs_nwrite == 0 && alldevs_nread == 0)
1820 			config_devunlink(dev, &af.af_garbage);
1821 		else {
1822 			dev->dv_del_gen = alldevs_gen;
1823 			alldevs_garbage = true;
1824 		}
1825 	}
1826 	config_alldevs_exit(&af);
1827 
1828 	return rv;
1829 }
1830 
1831 int
1832 config_detach_children(device_t parent, int flags)
1833 {
1834 	device_t dv;
1835 	deviter_t di;
1836 	int error = 0;
1837 
1838 	for (dv = deviter_first(&di, DEVITER_F_RW); dv != NULL;
1839 	     dv = deviter_next(&di)) {
1840 		if (device_parent(dv) != parent)
1841 			continue;
1842 		if ((error = config_detach(dv, flags)) != 0)
1843 			break;
1844 	}
1845 	deviter_release(&di);
1846 	return error;
1847 }
1848 
1849 device_t
1850 shutdown_first(struct shutdown_state *s)
1851 {
1852 	if (!s->initialized) {
1853 		deviter_init(&s->di, DEVITER_F_SHUTDOWN|DEVITER_F_LEAVES_FIRST);
1854 		s->initialized = true;
1855 	}
1856 	return shutdown_next(s);
1857 }
1858 
1859 device_t
1860 shutdown_next(struct shutdown_state *s)
1861 {
1862 	device_t dv;
1863 
1864 	while ((dv = deviter_next(&s->di)) != NULL && !device_is_active(dv))
1865 		;
1866 
1867 	if (dv == NULL)
1868 		s->initialized = false;
1869 
1870 	return dv;
1871 }
1872 
1873 bool
1874 config_detach_all(int how)
1875 {
1876 	static struct shutdown_state s;
1877 	device_t curdev;
1878 	bool progress = false;
1879 
1880 	if ((how & (RB_NOSYNC|RB_DUMP)) != 0)
1881 		return false;
1882 
1883 	for (curdev = shutdown_first(&s); curdev != NULL;
1884 	     curdev = shutdown_next(&s)) {
1885 		aprint_debug(" detaching %s, ", device_xname(curdev));
1886 		if (config_detach(curdev, DETACH_SHUTDOWN) == 0) {
1887 			progress = true;
1888 			aprint_debug("success.");
1889 		} else
1890 			aprint_debug("failed.");
1891 	}
1892 	return progress;
1893 }
1894 
1895 static bool
1896 device_is_ancestor_of(device_t ancestor, device_t descendant)
1897 {
1898 	device_t dv;
1899 
1900 	for (dv = descendant; dv != NULL; dv = device_parent(dv)) {
1901 		if (device_parent(dv) == ancestor)
1902 			return true;
1903 	}
1904 	return false;
1905 }
1906 
1907 int
1908 config_deactivate(device_t dev)
1909 {
1910 	deviter_t di;
1911 	const struct cfattach *ca;
1912 	device_t descendant;
1913 	int s, rv = 0, oflags;
1914 
1915 	for (descendant = deviter_first(&di, DEVITER_F_ROOT_FIRST);
1916 	     descendant != NULL;
1917 	     descendant = deviter_next(&di)) {
1918 		if (dev != descendant &&
1919 		    !device_is_ancestor_of(dev, descendant))
1920 			continue;
1921 
1922 		if ((descendant->dv_flags & DVF_ACTIVE) == 0)
1923 			continue;
1924 
1925 		ca = descendant->dv_cfattach;
1926 		oflags = descendant->dv_flags;
1927 
1928 		descendant->dv_flags &= ~DVF_ACTIVE;
1929 		if (ca->ca_activate == NULL)
1930 			continue;
1931 		s = splhigh();
1932 		rv = (*ca->ca_activate)(descendant, DVACT_DEACTIVATE);
1933 		splx(s);
1934 		if (rv != 0)
1935 			descendant->dv_flags = oflags;
1936 	}
1937 	deviter_release(&di);
1938 	return rv;
1939 }
1940 
1941 /*
1942  * Defer the configuration of the specified device until all
1943  * of its parent's devices have been attached.
1944  */
1945 void
1946 config_defer(device_t dev, void (*func)(device_t))
1947 {
1948 	struct deferred_config *dc;
1949 
1950 	if (dev->dv_parent == NULL)
1951 		panic("config_defer: can't defer config of a root device");
1952 
1953 #ifdef DIAGNOSTIC
1954 	TAILQ_FOREACH(dc, &deferred_config_queue, dc_queue) {
1955 		if (dc->dc_dev == dev)
1956 			panic("config_defer: deferred twice");
1957 	}
1958 #endif
1959 
1960 	dc = kmem_alloc(sizeof(*dc), KM_SLEEP);
1961 	if (dc == NULL)
1962 		panic("config_defer: unable to allocate callback");
1963 
1964 	dc->dc_dev = dev;
1965 	dc->dc_func = func;
1966 	TAILQ_INSERT_TAIL(&deferred_config_queue, dc, dc_queue);
1967 	config_pending_incr(dev);
1968 }
1969 
1970 /*
1971  * Defer some autoconfiguration for a device until after interrupts
1972  * are enabled.
1973  */
1974 void
1975 config_interrupts(device_t dev, void (*func)(device_t))
1976 {
1977 	struct deferred_config *dc;
1978 
1979 	/*
1980 	 * If interrupts are enabled, callback now.
1981 	 */
1982 	if (cold == 0) {
1983 		(*func)(dev);
1984 		return;
1985 	}
1986 
1987 #ifdef DIAGNOSTIC
1988 	TAILQ_FOREACH(dc, &interrupt_config_queue, dc_queue) {
1989 		if (dc->dc_dev == dev)
1990 			panic("config_interrupts: deferred twice");
1991 	}
1992 #endif
1993 
1994 	dc = kmem_alloc(sizeof(*dc), KM_SLEEP);
1995 	if (dc == NULL)
1996 		panic("config_interrupts: unable to allocate callback");
1997 
1998 	dc->dc_dev = dev;
1999 	dc->dc_func = func;
2000 	TAILQ_INSERT_TAIL(&interrupt_config_queue, dc, dc_queue);
2001 	config_pending_incr(dev);
2002 }
2003 
2004 /*
2005  * Defer some autoconfiguration for a device until after root file system
2006  * is mounted (to load firmware etc).
2007  */
2008 void
2009 config_mountroot(device_t dev, void (*func)(device_t))
2010 {
2011 	struct deferred_config *dc;
2012 
2013 	/*
2014 	 * If root file system is mounted, callback now.
2015 	 */
2016 	if (root_is_mounted) {
2017 		(*func)(dev);
2018 		return;
2019 	}
2020 
2021 #ifdef DIAGNOSTIC
2022 	TAILQ_FOREACH(dc, &mountroot_config_queue, dc_queue) {
2023 		if (dc->dc_dev == dev)
2024 			panic("%s: deferred twice", __func__);
2025 	}
2026 #endif
2027 
2028 	dc = kmem_alloc(sizeof(*dc), KM_SLEEP);
2029 	if (dc == NULL)
2030 		panic("%s: unable to allocate callback", __func__);
2031 
2032 	dc->dc_dev = dev;
2033 	dc->dc_func = func;
2034 	TAILQ_INSERT_TAIL(&mountroot_config_queue, dc, dc_queue);
2035 }
2036 
2037 /*
2038  * Process a deferred configuration queue.
2039  */
2040 static void
2041 config_process_deferred(struct deferred_config_head *queue,
2042     device_t parent)
2043 {
2044 	struct deferred_config *dc, *ndc;
2045 
2046 	for (dc = TAILQ_FIRST(queue); dc != NULL; dc = ndc) {
2047 		ndc = TAILQ_NEXT(dc, dc_queue);
2048 		if (parent == NULL || dc->dc_dev->dv_parent == parent) {
2049 			TAILQ_REMOVE(queue, dc, dc_queue);
2050 			(*dc->dc_func)(dc->dc_dev);
2051 			config_pending_decr(dc->dc_dev);
2052 			kmem_free(dc, sizeof(*dc));
2053 		}
2054 	}
2055 }
2056 
2057 /*
2058  * Manipulate the config_pending semaphore.
2059  */
2060 void
2061 config_pending_incr(device_t dev)
2062 {
2063 
2064 	mutex_enter(&config_misc_lock);
2065 	config_pending++;
2066 #ifdef DEBUG_AUTOCONF
2067 	printf("%s: %s %d\n", __func__, device_xname(dev), config_pending);
2068 #endif
2069 	mutex_exit(&config_misc_lock);
2070 }
2071 
2072 void
2073 config_pending_decr(device_t dev)
2074 {
2075 
2076 #ifdef DIAGNOSTIC
2077 	if (config_pending == 0)
2078 		panic("config_pending_decr: config_pending == 0");
2079 #endif
2080 	mutex_enter(&config_misc_lock);
2081 	config_pending--;
2082 #ifdef DEBUG_AUTOCONF
2083 	printf("%s: %s %d\n", __func__, device_xname(dev), config_pending);
2084 #endif
2085 	if (config_pending == 0)
2086 		cv_broadcast(&config_misc_cv);
2087 	mutex_exit(&config_misc_lock);
2088 }
2089 
2090 /*
2091  * Register a "finalization" routine.  Finalization routines are
2092  * called iteratively once all real devices have been found during
2093  * autoconfiguration, for as long as any one finalizer has done
2094  * any work.
2095  */
2096 int
2097 config_finalize_register(device_t dev, int (*fn)(device_t))
2098 {
2099 	struct finalize_hook *f;
2100 
2101 	/*
2102 	 * If finalization has already been done, invoke the
2103 	 * callback function now.
2104 	 */
2105 	if (config_finalize_done) {
2106 		while ((*fn)(dev) != 0)
2107 			/* loop */ ;
2108 		return 0;
2109 	}
2110 
2111 	/* Ensure this isn't already on the list. */
2112 	TAILQ_FOREACH(f, &config_finalize_list, f_list) {
2113 		if (f->f_func == fn && f->f_dev == dev)
2114 			return EEXIST;
2115 	}
2116 
2117 	f = kmem_alloc(sizeof(*f), KM_SLEEP);
2118 	f->f_func = fn;
2119 	f->f_dev = dev;
2120 	TAILQ_INSERT_TAIL(&config_finalize_list, f, f_list);
2121 
2122 	return 0;
2123 }
2124 
2125 void
2126 config_finalize(void)
2127 {
2128 	struct finalize_hook *f;
2129 	struct pdevinit *pdev;
2130 	extern struct pdevinit pdevinit[];
2131 	int errcnt, rv;
2132 
2133 	/*
2134 	 * Now that device driver threads have been created, wait for
2135 	 * them to finish any deferred autoconfiguration.
2136 	 */
2137 	mutex_enter(&config_misc_lock);
2138 	while (config_pending != 0)
2139 		cv_wait(&config_misc_cv, &config_misc_lock);
2140 	mutex_exit(&config_misc_lock);
2141 
2142 	KERNEL_LOCK(1, NULL);
2143 
2144 	/* Attach pseudo-devices. */
2145 	for (pdev = pdevinit; pdev->pdev_attach != NULL; pdev++)
2146 		(*pdev->pdev_attach)(pdev->pdev_count);
2147 
2148 	/* Run the hooks until none of them does any work. */
2149 	do {
2150 		rv = 0;
2151 		TAILQ_FOREACH(f, &config_finalize_list, f_list)
2152 			rv |= (*f->f_func)(f->f_dev);
2153 	} while (rv != 0);
2154 
2155 	config_finalize_done = 1;
2156 
2157 	/* Now free all the hooks. */
2158 	while ((f = TAILQ_FIRST(&config_finalize_list)) != NULL) {
2159 		TAILQ_REMOVE(&config_finalize_list, f, f_list);
2160 		kmem_free(f, sizeof(*f));
2161 	}
2162 
2163 	KERNEL_UNLOCK_ONE(NULL);
2164 
2165 	errcnt = aprint_get_error_count();
2166 	if ((boothowto & (AB_QUIET|AB_SILENT)) != 0 &&
2167 	    (boothowto & AB_VERBOSE) == 0) {
2168 		mutex_enter(&config_misc_lock);
2169 		if (config_do_twiddle) {
2170 			config_do_twiddle = 0;
2171 			printf_nolog(" done.\n");
2172 		}
2173 		mutex_exit(&config_misc_lock);
2174 		if (errcnt != 0) {
2175 			printf("WARNING: %d error%s while detecting hardware; "
2176 			    "check system log.\n", errcnt,
2177 			    errcnt == 1 ? "" : "s");
2178 		}
2179 	}
2180 }
2181 
2182 void
2183 config_twiddle_init(void)
2184 {
2185 
2186 	if ((boothowto & (AB_SILENT|AB_VERBOSE)) == AB_SILENT) {
2187 		config_do_twiddle = 1;
2188 	}
2189 	callout_setfunc(&config_twiddle_ch, config_twiddle_fn, NULL);
2190 }
2191 
2192 void
2193 config_twiddle_fn(void *cookie)
2194 {
2195 
2196 	mutex_enter(&config_misc_lock);
2197 	if (config_do_twiddle) {
2198 		twiddle();
2199 		callout_schedule(&config_twiddle_ch, mstohz(100));
2200 	}
2201 	mutex_exit(&config_misc_lock);
2202 }
2203 
2204 static void
2205 config_alldevs_enter(struct alldevs_foray *af)
2206 {
2207 	TAILQ_INIT(&af->af_garbage);
2208 	mutex_enter(&alldevs_mtx);
2209 	config_collect_garbage(&af->af_garbage);
2210 }
2211 
2212 static void
2213 config_alldevs_exit(struct alldevs_foray *af)
2214 {
2215 	mutex_exit(&alldevs_mtx);
2216 	config_dump_garbage(&af->af_garbage);
2217 }
2218 
2219 /*
2220  * device_lookup:
2221  *
2222  *	Look up a device instance for a given driver.
2223  */
2224 device_t
2225 device_lookup(cfdriver_t cd, int unit)
2226 {
2227 	device_t dv;
2228 
2229 	mutex_enter(&alldevs_mtx);
2230 	if (unit < 0 || unit >= cd->cd_ndevs)
2231 		dv = NULL;
2232 	else if ((dv = cd->cd_devs[unit]) != NULL && dv->dv_del_gen != 0)
2233 		dv = NULL;
2234 	mutex_exit(&alldevs_mtx);
2235 
2236 	return dv;
2237 }
2238 
2239 /*
2240  * device_lookup_private:
2241  *
2242  *	Look up a softc instance for a given driver.
2243  */
2244 void *
2245 device_lookup_private(cfdriver_t cd, int unit)
2246 {
2247 
2248 	return device_private(device_lookup(cd, unit));
2249 }
2250 
2251 /*
2252  * device_find_by_xname:
2253  *
2254  *	Returns the device of the given name or NULL if it doesn't exist.
2255  */
2256 device_t
2257 device_find_by_xname(const char *name)
2258 {
2259 	device_t dv;
2260 	deviter_t di;
2261 
2262 	for (dv = deviter_first(&di, 0); dv != NULL; dv = deviter_next(&di)) {
2263 		if (strcmp(device_xname(dv), name) == 0)
2264 			break;
2265 	}
2266 	deviter_release(&di);
2267 
2268 	return dv;
2269 }
2270 
2271 /*
2272  * device_find_by_driver_unit:
2273  *
2274  *	Returns the device of the given driver name and unit or
2275  *	NULL if it doesn't exist.
2276  */
2277 device_t
2278 device_find_by_driver_unit(const char *name, int unit)
2279 {
2280 	struct cfdriver *cd;
2281 
2282 	if ((cd = config_cfdriver_lookup(name)) == NULL)
2283 		return NULL;
2284 	return device_lookup(cd, unit);
2285 }
2286 
2287 /*
2288  * Power management related functions.
2289  */
2290 
2291 bool
2292 device_pmf_is_registered(device_t dev)
2293 {
2294 	return (dev->dv_flags & DVF_POWER_HANDLERS) != 0;
2295 }
2296 
2297 bool
2298 device_pmf_driver_suspend(device_t dev, const pmf_qual_t *qual)
2299 {
2300 	if ((dev->dv_flags & DVF_DRIVER_SUSPENDED) != 0)
2301 		return true;
2302 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) == 0)
2303 		return false;
2304 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_DRIVER &&
2305 	    dev->dv_driver_suspend != NULL &&
2306 	    !(*dev->dv_driver_suspend)(dev, qual))
2307 		return false;
2308 
2309 	dev->dv_flags |= DVF_DRIVER_SUSPENDED;
2310 	return true;
2311 }
2312 
2313 bool
2314 device_pmf_driver_resume(device_t dev, const pmf_qual_t *qual)
2315 {
2316 	if ((dev->dv_flags & DVF_DRIVER_SUSPENDED) == 0)
2317 		return true;
2318 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) != 0)
2319 		return false;
2320 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_DRIVER &&
2321 	    dev->dv_driver_resume != NULL &&
2322 	    !(*dev->dv_driver_resume)(dev, qual))
2323 		return false;
2324 
2325 	dev->dv_flags &= ~DVF_DRIVER_SUSPENDED;
2326 	return true;
2327 }
2328 
2329 bool
2330 device_pmf_driver_shutdown(device_t dev, int how)
2331 {
2332 
2333 	if (*dev->dv_driver_shutdown != NULL &&
2334 	    !(*dev->dv_driver_shutdown)(dev, how))
2335 		return false;
2336 	return true;
2337 }
2338 
2339 bool
2340 device_pmf_driver_register(device_t dev,
2341     bool (*suspend)(device_t, const pmf_qual_t *),
2342     bool (*resume)(device_t, const pmf_qual_t *),
2343     bool (*shutdown)(device_t, int))
2344 {
2345 	dev->dv_driver_suspend = suspend;
2346 	dev->dv_driver_resume = resume;
2347 	dev->dv_driver_shutdown = shutdown;
2348 	dev->dv_flags |= DVF_POWER_HANDLERS;
2349 	return true;
2350 }
2351 
2352 static const char *
2353 curlwp_name(void)
2354 {
2355 	if (curlwp->l_name != NULL)
2356 		return curlwp->l_name;
2357 	else
2358 		return curlwp->l_proc->p_comm;
2359 }
2360 
2361 void
2362 device_pmf_driver_deregister(device_t dev)
2363 {
2364 	device_lock_t dvl = device_getlock(dev);
2365 
2366 	dev->dv_driver_suspend = NULL;
2367 	dev->dv_driver_resume = NULL;
2368 
2369 	mutex_enter(&dvl->dvl_mtx);
2370 	dev->dv_flags &= ~DVF_POWER_HANDLERS;
2371 	while (dvl->dvl_nlock > 0 || dvl->dvl_nwait > 0) {
2372 		/* Wake a thread that waits for the lock.  That
2373 		 * thread will fail to acquire the lock, and then
2374 		 * it will wake the next thread that waits for the
2375 		 * lock, or else it will wake us.
2376 		 */
2377 		cv_signal(&dvl->dvl_cv);
2378 		pmflock_debug(dev, __func__, __LINE__);
2379 		cv_wait(&dvl->dvl_cv, &dvl->dvl_mtx);
2380 		pmflock_debug(dev, __func__, __LINE__);
2381 	}
2382 	mutex_exit(&dvl->dvl_mtx);
2383 }
2384 
2385 bool
2386 device_pmf_driver_child_register(device_t dev)
2387 {
2388 	device_t parent = device_parent(dev);
2389 
2390 	if (parent == NULL || parent->dv_driver_child_register == NULL)
2391 		return true;
2392 	return (*parent->dv_driver_child_register)(dev);
2393 }
2394 
2395 void
2396 device_pmf_driver_set_child_register(device_t dev,
2397     bool (*child_register)(device_t))
2398 {
2399 	dev->dv_driver_child_register = child_register;
2400 }
2401 
2402 static void
2403 pmflock_debug(device_t dev, const char *func, int line)
2404 {
2405 	device_lock_t dvl = device_getlock(dev);
2406 
2407 	aprint_debug_dev(dev, "%s.%d, %s dvl_nlock %d dvl_nwait %d dv_flags %x\n",
2408 	    func, line, curlwp_name(), dvl->dvl_nlock, dvl->dvl_nwait,
2409 	    dev->dv_flags);
2410 }
2411 
2412 static bool
2413 device_pmf_lock1(device_t dev)
2414 {
2415 	device_lock_t dvl = device_getlock(dev);
2416 
2417 	while (device_pmf_is_registered(dev) &&
2418 	    dvl->dvl_nlock > 0 && dvl->dvl_holder != curlwp) {
2419 		dvl->dvl_nwait++;
2420 		pmflock_debug(dev, __func__, __LINE__);
2421 		cv_wait(&dvl->dvl_cv, &dvl->dvl_mtx);
2422 		pmflock_debug(dev, __func__, __LINE__);
2423 		dvl->dvl_nwait--;
2424 	}
2425 	if (!device_pmf_is_registered(dev)) {
2426 		pmflock_debug(dev, __func__, __LINE__);
2427 		/* We could not acquire the lock, but some other thread may
2428 		 * wait for it, also.  Wake that thread.
2429 		 */
2430 		cv_signal(&dvl->dvl_cv);
2431 		return false;
2432 	}
2433 	dvl->dvl_nlock++;
2434 	dvl->dvl_holder = curlwp;
2435 	pmflock_debug(dev, __func__, __LINE__);
2436 	return true;
2437 }
2438 
2439 bool
2440 device_pmf_lock(device_t dev)
2441 {
2442 	bool rc;
2443 	device_lock_t dvl = device_getlock(dev);
2444 
2445 	mutex_enter(&dvl->dvl_mtx);
2446 	rc = device_pmf_lock1(dev);
2447 	mutex_exit(&dvl->dvl_mtx);
2448 
2449 	return rc;
2450 }
2451 
2452 void
2453 device_pmf_unlock(device_t dev)
2454 {
2455 	device_lock_t dvl = device_getlock(dev);
2456 
2457 	KASSERT(dvl->dvl_nlock > 0);
2458 	mutex_enter(&dvl->dvl_mtx);
2459 	if (--dvl->dvl_nlock == 0)
2460 		dvl->dvl_holder = NULL;
2461 	cv_signal(&dvl->dvl_cv);
2462 	pmflock_debug(dev, __func__, __LINE__);
2463 	mutex_exit(&dvl->dvl_mtx);
2464 }
2465 
2466 device_lock_t
2467 device_getlock(device_t dev)
2468 {
2469 	return &dev->dv_lock;
2470 }
2471 
2472 void *
2473 device_pmf_bus_private(device_t dev)
2474 {
2475 	return dev->dv_bus_private;
2476 }
2477 
2478 bool
2479 device_pmf_bus_suspend(device_t dev, const pmf_qual_t *qual)
2480 {
2481 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) != 0)
2482 		return true;
2483 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) == 0 ||
2484 	    (dev->dv_flags & DVF_DRIVER_SUSPENDED) == 0)
2485 		return false;
2486 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_BUS &&
2487 	    dev->dv_bus_suspend != NULL &&
2488 	    !(*dev->dv_bus_suspend)(dev, qual))
2489 		return false;
2490 
2491 	dev->dv_flags |= DVF_BUS_SUSPENDED;
2492 	return true;
2493 }
2494 
2495 bool
2496 device_pmf_bus_resume(device_t dev, const pmf_qual_t *qual)
2497 {
2498 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) == 0)
2499 		return true;
2500 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_BUS &&
2501 	    dev->dv_bus_resume != NULL &&
2502 	    !(*dev->dv_bus_resume)(dev, qual))
2503 		return false;
2504 
2505 	dev->dv_flags &= ~DVF_BUS_SUSPENDED;
2506 	return true;
2507 }
2508 
2509 bool
2510 device_pmf_bus_shutdown(device_t dev, int how)
2511 {
2512 
2513 	if (*dev->dv_bus_shutdown != NULL &&
2514 	    !(*dev->dv_bus_shutdown)(dev, how))
2515 		return false;
2516 	return true;
2517 }
2518 
2519 void
2520 device_pmf_bus_register(device_t dev, void *priv,
2521     bool (*suspend)(device_t, const pmf_qual_t *),
2522     bool (*resume)(device_t, const pmf_qual_t *),
2523     bool (*shutdown)(device_t, int), void (*deregister)(device_t))
2524 {
2525 	dev->dv_bus_private = priv;
2526 	dev->dv_bus_resume = resume;
2527 	dev->dv_bus_suspend = suspend;
2528 	dev->dv_bus_shutdown = shutdown;
2529 	dev->dv_bus_deregister = deregister;
2530 }
2531 
2532 void
2533 device_pmf_bus_deregister(device_t dev)
2534 {
2535 	if (dev->dv_bus_deregister == NULL)
2536 		return;
2537 	(*dev->dv_bus_deregister)(dev);
2538 	dev->dv_bus_private = NULL;
2539 	dev->dv_bus_suspend = NULL;
2540 	dev->dv_bus_resume = NULL;
2541 	dev->dv_bus_deregister = NULL;
2542 }
2543 
2544 void *
2545 device_pmf_class_private(device_t dev)
2546 {
2547 	return dev->dv_class_private;
2548 }
2549 
2550 bool
2551 device_pmf_class_suspend(device_t dev, const pmf_qual_t *qual)
2552 {
2553 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) != 0)
2554 		return true;
2555 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_CLASS &&
2556 	    dev->dv_class_suspend != NULL &&
2557 	    !(*dev->dv_class_suspend)(dev, qual))
2558 		return false;
2559 
2560 	dev->dv_flags |= DVF_CLASS_SUSPENDED;
2561 	return true;
2562 }
2563 
2564 bool
2565 device_pmf_class_resume(device_t dev, const pmf_qual_t *qual)
2566 {
2567 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) == 0)
2568 		return true;
2569 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) != 0 ||
2570 	    (dev->dv_flags & DVF_DRIVER_SUSPENDED) != 0)
2571 		return false;
2572 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_CLASS &&
2573 	    dev->dv_class_resume != NULL &&
2574 	    !(*dev->dv_class_resume)(dev, qual))
2575 		return false;
2576 
2577 	dev->dv_flags &= ~DVF_CLASS_SUSPENDED;
2578 	return true;
2579 }
2580 
2581 void
2582 device_pmf_class_register(device_t dev, void *priv,
2583     bool (*suspend)(device_t, const pmf_qual_t *),
2584     bool (*resume)(device_t, const pmf_qual_t *),
2585     void (*deregister)(device_t))
2586 {
2587 	dev->dv_class_private = priv;
2588 	dev->dv_class_suspend = suspend;
2589 	dev->dv_class_resume = resume;
2590 	dev->dv_class_deregister = deregister;
2591 }
2592 
2593 void
2594 device_pmf_class_deregister(device_t dev)
2595 {
2596 	if (dev->dv_class_deregister == NULL)
2597 		return;
2598 	(*dev->dv_class_deregister)(dev);
2599 	dev->dv_class_private = NULL;
2600 	dev->dv_class_suspend = NULL;
2601 	dev->dv_class_resume = NULL;
2602 	dev->dv_class_deregister = NULL;
2603 }
2604 
2605 bool
2606 device_active(device_t dev, devactive_t type)
2607 {
2608 	size_t i;
2609 
2610 	if (dev->dv_activity_count == 0)
2611 		return false;
2612 
2613 	for (i = 0; i < dev->dv_activity_count; ++i) {
2614 		if (dev->dv_activity_handlers[i] == NULL)
2615 			break;
2616 		(*dev->dv_activity_handlers[i])(dev, type);
2617 	}
2618 
2619 	return true;
2620 }
2621 
2622 bool
2623 device_active_register(device_t dev, void (*handler)(device_t, devactive_t))
2624 {
2625 	void (**new_handlers)(device_t, devactive_t);
2626 	void (**old_handlers)(device_t, devactive_t);
2627 	size_t i, old_size, new_size;
2628 	int s;
2629 
2630 	old_handlers = dev->dv_activity_handlers;
2631 	old_size = dev->dv_activity_count;
2632 
2633 	KASSERT(old_size == 0 || old_handlers != NULL);
2634 
2635 	for (i = 0; i < old_size; ++i) {
2636 		KASSERT(old_handlers[i] != handler);
2637 		if (old_handlers[i] == NULL) {
2638 			old_handlers[i] = handler;
2639 			return true;
2640 		}
2641 	}
2642 
2643 	new_size = old_size + 4;
2644 	new_handlers = kmem_alloc(sizeof(void *[new_size]), KM_SLEEP);
2645 
2646 	for (i = 0; i < old_size; ++i)
2647 		new_handlers[i] = old_handlers[i];
2648 	new_handlers[old_size] = handler;
2649 	for (i = old_size+1; i < new_size; ++i)
2650 		new_handlers[i] = NULL;
2651 
2652 	s = splhigh();
2653 	dev->dv_activity_count = new_size;
2654 	dev->dv_activity_handlers = new_handlers;
2655 	splx(s);
2656 
2657 	if (old_size > 0)
2658 		kmem_free(old_handlers, sizeof(void * [old_size]));
2659 
2660 	return true;
2661 }
2662 
2663 void
2664 device_active_deregister(device_t dev, void (*handler)(device_t, devactive_t))
2665 {
2666 	void (**old_handlers)(device_t, devactive_t);
2667 	size_t i, old_size;
2668 	int s;
2669 
2670 	old_handlers = dev->dv_activity_handlers;
2671 	old_size = dev->dv_activity_count;
2672 
2673 	for (i = 0; i < old_size; ++i) {
2674 		if (old_handlers[i] == handler)
2675 			break;
2676 		if (old_handlers[i] == NULL)
2677 			return; /* XXX panic? */
2678 	}
2679 
2680 	if (i == old_size)
2681 		return; /* XXX panic? */
2682 
2683 	for (; i < old_size - 1; ++i) {
2684 		if ((old_handlers[i] = old_handlers[i + 1]) != NULL)
2685 			continue;
2686 
2687 		if (i == 0) {
2688 			s = splhigh();
2689 			dev->dv_activity_count = 0;
2690 			dev->dv_activity_handlers = NULL;
2691 			splx(s);
2692 			kmem_free(old_handlers, sizeof(void *[old_size]));
2693 		}
2694 		return;
2695 	}
2696 	old_handlers[i] = NULL;
2697 }
2698 
2699 /* Return true iff the device_t `dev' exists at generation `gen'. */
2700 static bool
2701 device_exists_at(device_t dv, devgen_t gen)
2702 {
2703 	return (dv->dv_del_gen == 0 || dv->dv_del_gen > gen) &&
2704 	    dv->dv_add_gen <= gen;
2705 }
2706 
2707 static bool
2708 deviter_visits(const deviter_t *di, device_t dv)
2709 {
2710 	return device_exists_at(dv, di->di_gen);
2711 }
2712 
2713 /*
2714  * Device Iteration
2715  *
2716  * deviter_t: a device iterator.  Holds state for a "walk" visiting
2717  *     each device_t's in the device tree.
2718  *
2719  * deviter_init(di, flags): initialize the device iterator `di'
2720  *     to "walk" the device tree.  deviter_next(di) will return
2721  *     the first device_t in the device tree, or NULL if there are
2722  *     no devices.
2723  *
2724  *     `flags' is one or more of DEVITER_F_RW, indicating that the
2725  *     caller intends to modify the device tree by calling
2726  *     config_detach(9) on devices in the order that the iterator
2727  *     returns them; DEVITER_F_ROOT_FIRST, asking for the devices
2728  *     nearest the "root" of the device tree to be returned, first;
2729  *     DEVITER_F_LEAVES_FIRST, asking for the devices furthest from
2730  *     the root of the device tree, first; and DEVITER_F_SHUTDOWN,
2731  *     indicating both that deviter_init() should not respect any
2732  *     locks on the device tree, and that deviter_next(di) may run
2733  *     in more than one LWP before the walk has finished.
2734  *
2735  *     Only one DEVITER_F_RW iterator may be in the device tree at
2736  *     once.
2737  *
2738  *     DEVITER_F_SHUTDOWN implies DEVITER_F_RW.
2739  *
2740  *     Results are undefined if the flags DEVITER_F_ROOT_FIRST and
2741  *     DEVITER_F_LEAVES_FIRST are used in combination.
2742  *
2743  * deviter_first(di, flags): initialize the device iterator `di'
2744  *     and return the first device_t in the device tree, or NULL
2745  *     if there are no devices.  The statement
2746  *
2747  *         dv = deviter_first(di);
2748  *
2749  *     is shorthand for
2750  *
2751  *         deviter_init(di);
2752  *         dv = deviter_next(di);
2753  *
2754  * deviter_next(di): return the next device_t in the device tree,
2755  *     or NULL if there are no more devices.  deviter_next(di)
2756  *     is undefined if `di' was not initialized with deviter_init() or
2757  *     deviter_first().
2758  *
2759  * deviter_release(di): stops iteration (subsequent calls to
2760  *     deviter_next() will return NULL), releases any locks and
2761  *     resources held by the device iterator.
2762  *
2763  * Device iteration does not return device_t's in any particular
2764  * order.  An iterator will never return the same device_t twice.
2765  * Device iteration is guaranteed to complete---i.e., if deviter_next(di)
2766  * is called repeatedly on the same `di', it will eventually return
2767  * NULL.  It is ok to attach/detach devices during device iteration.
2768  */
2769 void
2770 deviter_init(deviter_t *di, deviter_flags_t flags)
2771 {
2772 	device_t dv;
2773 
2774 	memset(di, 0, sizeof(*di));
2775 
2776 	mutex_enter(&alldevs_mtx);
2777 	if ((flags & DEVITER_F_SHUTDOWN) != 0)
2778 		flags |= DEVITER_F_RW;
2779 
2780 	if ((flags & DEVITER_F_RW) != 0)
2781 		alldevs_nwrite++;
2782 	else
2783 		alldevs_nread++;
2784 	di->di_gen = alldevs_gen++;
2785 	mutex_exit(&alldevs_mtx);
2786 
2787 	di->di_flags = flags;
2788 
2789 	switch (di->di_flags & (DEVITER_F_LEAVES_FIRST|DEVITER_F_ROOT_FIRST)) {
2790 	case DEVITER_F_LEAVES_FIRST:
2791 		TAILQ_FOREACH(dv, &alldevs, dv_list) {
2792 			if (!deviter_visits(di, dv))
2793 				continue;
2794 			di->di_curdepth = MAX(di->di_curdepth, dv->dv_depth);
2795 		}
2796 		break;
2797 	case DEVITER_F_ROOT_FIRST:
2798 		TAILQ_FOREACH(dv, &alldevs, dv_list) {
2799 			if (!deviter_visits(di, dv))
2800 				continue;
2801 			di->di_maxdepth = MAX(di->di_maxdepth, dv->dv_depth);
2802 		}
2803 		break;
2804 	default:
2805 		break;
2806 	}
2807 
2808 	deviter_reinit(di);
2809 }
2810 
2811 static void
2812 deviter_reinit(deviter_t *di)
2813 {
2814 	if ((di->di_flags & DEVITER_F_RW) != 0)
2815 		di->di_prev = TAILQ_LAST(&alldevs, devicelist);
2816 	else
2817 		di->di_prev = TAILQ_FIRST(&alldevs);
2818 }
2819 
2820 device_t
2821 deviter_first(deviter_t *di, deviter_flags_t flags)
2822 {
2823 	deviter_init(di, flags);
2824 	return deviter_next(di);
2825 }
2826 
2827 static device_t
2828 deviter_next2(deviter_t *di)
2829 {
2830 	device_t dv;
2831 
2832 	dv = di->di_prev;
2833 
2834 	if (dv == NULL)
2835 		return NULL;
2836 
2837 	if ((di->di_flags & DEVITER_F_RW) != 0)
2838 		di->di_prev = TAILQ_PREV(dv, devicelist, dv_list);
2839 	else
2840 		di->di_prev = TAILQ_NEXT(dv, dv_list);
2841 
2842 	return dv;
2843 }
2844 
2845 static device_t
2846 deviter_next1(deviter_t *di)
2847 {
2848 	device_t dv;
2849 
2850 	do {
2851 		dv = deviter_next2(di);
2852 	} while (dv != NULL && !deviter_visits(di, dv));
2853 
2854 	return dv;
2855 }
2856 
2857 device_t
2858 deviter_next(deviter_t *di)
2859 {
2860 	device_t dv = NULL;
2861 
2862 	switch (di->di_flags & (DEVITER_F_LEAVES_FIRST|DEVITER_F_ROOT_FIRST)) {
2863 	case 0:
2864 		return deviter_next1(di);
2865 	case DEVITER_F_LEAVES_FIRST:
2866 		while (di->di_curdepth >= 0) {
2867 			if ((dv = deviter_next1(di)) == NULL) {
2868 				di->di_curdepth--;
2869 				deviter_reinit(di);
2870 			} else if (dv->dv_depth == di->di_curdepth)
2871 				break;
2872 		}
2873 		return dv;
2874 	case DEVITER_F_ROOT_FIRST:
2875 		while (di->di_curdepth <= di->di_maxdepth) {
2876 			if ((dv = deviter_next1(di)) == NULL) {
2877 				di->di_curdepth++;
2878 				deviter_reinit(di);
2879 			} else if (dv->dv_depth == di->di_curdepth)
2880 				break;
2881 		}
2882 		return dv;
2883 	default:
2884 		return NULL;
2885 	}
2886 }
2887 
2888 void
2889 deviter_release(deviter_t *di)
2890 {
2891 	bool rw = (di->di_flags & DEVITER_F_RW) != 0;
2892 
2893 	mutex_enter(&alldevs_mtx);
2894 	if (rw)
2895 		--alldevs_nwrite;
2896 	else
2897 		--alldevs_nread;
2898 	/* XXX wake a garbage-collection thread */
2899 	mutex_exit(&alldevs_mtx);
2900 }
2901 
2902 const char *
2903 cfdata_ifattr(const struct cfdata *cf)
2904 {
2905 	return cf->cf_pspec->cfp_iattr;
2906 }
2907 
2908 bool
2909 ifattr_match(const char *snull, const char *t)
2910 {
2911 	return (snull == NULL) || strcmp(snull, t) == 0;
2912 }
2913 
2914 void
2915 null_childdetached(device_t self, device_t child)
2916 {
2917 	/* do nothing */
2918 }
2919 
2920 static void
2921 sysctl_detach_setup(struct sysctllog **clog)
2922 {
2923 
2924 	sysctl_createv(clog, 0, NULL, NULL,
2925 		CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
2926 		CTLTYPE_BOOL, "detachall",
2927 		SYSCTL_DESCR("Detach all devices at shutdown"),
2928 		NULL, 0, &detachall, 0,
2929 		CTL_KERN, CTL_CREATE, CTL_EOL);
2930 }
2931