xref: /netbsd-src/sys/kern/subr_autoconf.c (revision 27fd3f6531803adac12382d7643a9a492b576601)
1 /* $NetBSD: subr_autoconf.c,v 1.185 2009/09/21 12:14:47 pooka 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 1.185 2009/09/21 12:14:47 pooka 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/malloc.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/vnode.h>
103 #include <sys/mount.h>
104 #include <sys/namei.h>
105 #include <sys/unistd.h>
106 #include <sys/fcntl.h>
107 #include <sys/lockf.h>
108 #include <sys/callout.h>
109 #include <sys/devmon.h>
110 #include <sys/cpu.h>
111 #include <sys/sysctl.h>
112 
113 #include <sys/disk.h>
114 
115 #include <machine/limits.h>
116 
117 #if defined(__i386__) && defined(_KERNEL_OPT)
118 #include "opt_splash.h"
119 #if defined(SPLASHSCREEN) && defined(SPLASHSCREEN_PROGRESS)
120 #include <dev/splash/splash.h>
121 extern struct splash_progress *splash_progress_state;
122 #endif
123 #endif
124 
125 /*
126  * Autoconfiguration subroutines.
127  */
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 	struct	device *parent;
160 	const int *locs;
161 	void	*aux;
162 	struct	cfdata *match;
163 	int	pri;
164 };
165 
166 static char *number(char *, int);
167 static void mapply(struct matchinfo *, cfdata_t);
168 static device_t config_devalloc(const device_t, const cfdata_t, const int *);
169 static void config_devdealloc(device_t);
170 static void config_makeroom(int, struct cfdriver *);
171 static void config_devlink(device_t);
172 static void config_devunlink(device_t);
173 
174 static void pmflock_debug(device_t, const char *, int);
175 
176 static device_t deviter_next1(deviter_t *);
177 static void deviter_reinit(deviter_t *);
178 
179 struct deferred_config {
180 	TAILQ_ENTRY(deferred_config) dc_queue;
181 	device_t dc_dev;
182 	void (*dc_func)(device_t);
183 };
184 
185 TAILQ_HEAD(deferred_config_head, deferred_config);
186 
187 struct deferred_config_head deferred_config_queue =
188 	TAILQ_HEAD_INITIALIZER(deferred_config_queue);
189 struct deferred_config_head interrupt_config_queue =
190 	TAILQ_HEAD_INITIALIZER(interrupt_config_queue);
191 int interrupt_config_threads = 8;
192 
193 static void config_process_deferred(struct deferred_config_head *, device_t);
194 
195 /* Hooks to finalize configuration once all real devices have been found. */
196 struct finalize_hook {
197 	TAILQ_ENTRY(finalize_hook) f_list;
198 	int (*f_func)(device_t);
199 	device_t f_dev;
200 };
201 static TAILQ_HEAD(, finalize_hook) config_finalize_list =
202 	TAILQ_HEAD_INITIALIZER(config_finalize_list);
203 static int config_finalize_done;
204 
205 /* list of all devices */
206 struct devicelist alldevs = TAILQ_HEAD_INITIALIZER(alldevs);
207 kcondvar_t alldevs_cv;
208 kmutex_t alldevs_mtx;
209 static int alldevs_nread = 0;
210 static int alldevs_nwrite = 0;
211 static lwp_t *alldevs_writer = NULL;
212 
213 static int config_pending;		/* semaphore for mountroot */
214 static kmutex_t config_misc_lock;
215 static kcondvar_t config_misc_cv;
216 
217 static int detachall = 0;
218 
219 #define	STREQ(s1, s2)			\
220 	(*(s1) == *(s2) && strcmp((s1), (s2)) == 0)
221 
222 static bool config_initialized = false;	/* config_init() has been called. */
223 
224 static int config_do_twiddle;
225 static callout_t config_twiddle_ch;
226 
227 static void sysctl_detach_setup(struct sysctllog **);
228 
229 /*
230  * Initialize the autoconfiguration data structures.  Normally this
231  * is done by configure(), but some platforms need to do this very
232  * early (to e.g. initialize the console).
233  */
234 void
235 config_init(void)
236 {
237 	const struct cfattachinit *cfai;
238 	int i, j;
239 
240 	KASSERT(config_initialized == false);
241 
242 	mutex_init(&alldevs_mtx, MUTEX_DEFAULT, IPL_NONE);
243 	cv_init(&alldevs_cv, "alldevs");
244 
245 	mutex_init(&config_misc_lock, MUTEX_DEFAULT, IPL_NONE);
246 	cv_init(&config_misc_cv, "cfgmisc");
247 
248 	callout_init(&config_twiddle_ch, CALLOUT_MPSAFE);
249 
250 	/* allcfdrivers is statically initialized. */
251 	for (i = 0; cfdriver_list_initial[i] != NULL; i++) {
252 		if (config_cfdriver_attach(cfdriver_list_initial[i]) != 0)
253 			panic("configure: duplicate `%s' drivers",
254 			    cfdriver_list_initial[i]->cd_name);
255 	}
256 
257 	for (cfai = &cfattachinit[0]; cfai->cfai_name != NULL; cfai++) {
258 		for (j = 0; cfai->cfai_list[j] != NULL; j++) {
259 			if (config_cfattach_attach(cfai->cfai_name,
260 						   cfai->cfai_list[j]) != 0)
261 				panic("configure: duplicate `%s' attachment "
262 				    "of `%s' driver",
263 				    cfai->cfai_list[j]->ca_name,
264 				    cfai->cfai_name);
265 		}
266 	}
267 
268 	initcftable.ct_cfdata = cfdata;
269 	TAILQ_INSERT_TAIL(&allcftables, &initcftable, ct_list);
270 
271 	config_initialized = true;
272 }
273 
274 void
275 config_init_mi(void)
276 {
277 
278 	if (!config_initialized)
279 		config_init();
280 
281 	sysctl_detach_setup(NULL);
282 }
283 
284 void
285 config_deferred(device_t dev)
286 {
287 	config_process_deferred(&deferred_config_queue, dev);
288 	config_process_deferred(&interrupt_config_queue, dev);
289 }
290 
291 static void
292 config_interrupts_thread(void *cookie)
293 {
294 	struct deferred_config *dc;
295 
296 	while ((dc = TAILQ_FIRST(&interrupt_config_queue)) != NULL) {
297 		TAILQ_REMOVE(&interrupt_config_queue, dc, dc_queue);
298 		(*dc->dc_func)(dc->dc_dev);
299 		kmem_free(dc, sizeof(*dc));
300 		config_pending_decr();
301 	}
302 	kthread_exit(0);
303 }
304 
305 void
306 config_create_interruptthreads()
307 {
308 	int i;
309 
310 	for (i = 0; i < interrupt_config_threads; i++) {
311 		(void)kthread_create(PRI_NONE, 0, NULL,
312 		    config_interrupts_thread, NULL, NULL, "config");
313 	}
314 }
315 
316 /*
317  * Announce device attach/detach to userland listeners.
318  */
319 static void
320 devmon_report_device(device_t dev, bool isattach)
321 {
322 #if NDRVCTL > 0
323 	prop_dictionary_t ev;
324 	const char *parent;
325 	const char *what;
326 	device_t pdev = device_parent(dev);
327 
328 	ev = prop_dictionary_create();
329 	if (ev == NULL)
330 		return;
331 
332 	what = (isattach ? "device-attach" : "device-detach");
333 	parent = (pdev == NULL ? "root" : device_xname(pdev));
334 	if (!prop_dictionary_set_cstring(ev, "device", device_xname(dev)) ||
335 	    !prop_dictionary_set_cstring(ev, "parent", parent)) {
336 		prop_object_release(ev);
337 		return;
338 	}
339 
340 	devmon_insert(what, ev);
341 #endif
342 }
343 
344 /*
345  * Add a cfdriver to the system.
346  */
347 int
348 config_cfdriver_attach(struct cfdriver *cd)
349 {
350 	struct cfdriver *lcd;
351 
352 	/* Make sure this driver isn't already in the system. */
353 	LIST_FOREACH(lcd, &allcfdrivers, cd_list) {
354 		if (STREQ(lcd->cd_name, cd->cd_name))
355 			return EEXIST;
356 	}
357 
358 	LIST_INIT(&cd->cd_attach);
359 	LIST_INSERT_HEAD(&allcfdrivers, cd, cd_list);
360 
361 	return 0;
362 }
363 
364 /*
365  * Remove a cfdriver from the system.
366  */
367 int
368 config_cfdriver_detach(struct cfdriver *cd)
369 {
370 	int i;
371 
372 	/* Make sure there are no active instances. */
373 	for (i = 0; i < cd->cd_ndevs; i++) {
374 		if (cd->cd_devs[i] != NULL)
375 			return EBUSY;
376 	}
377 
378 	/* ...and no attachments loaded. */
379 	if (LIST_EMPTY(&cd->cd_attach) == 0)
380 		return EBUSY;
381 
382 	LIST_REMOVE(cd, cd_list);
383 
384 	KASSERT(cd->cd_devs == NULL);
385 
386 	return 0;
387 }
388 
389 /*
390  * Look up a cfdriver by name.
391  */
392 struct cfdriver *
393 config_cfdriver_lookup(const char *name)
394 {
395 	struct cfdriver *cd;
396 
397 	LIST_FOREACH(cd, &allcfdrivers, cd_list) {
398 		if (STREQ(cd->cd_name, name))
399 			return cd;
400 	}
401 
402 	return NULL;
403 }
404 
405 /*
406  * Add a cfattach to the specified driver.
407  */
408 int
409 config_cfattach_attach(const char *driver, struct cfattach *ca)
410 {
411 	struct cfattach *lca;
412 	struct cfdriver *cd;
413 
414 	cd = config_cfdriver_lookup(driver);
415 	if (cd == NULL)
416 		return ESRCH;
417 
418 	/* Make sure this attachment isn't already on this driver. */
419 	LIST_FOREACH(lca, &cd->cd_attach, ca_list) {
420 		if (STREQ(lca->ca_name, ca->ca_name))
421 			return EEXIST;
422 	}
423 
424 	LIST_INSERT_HEAD(&cd->cd_attach, ca, ca_list);
425 
426 	return 0;
427 }
428 
429 /*
430  * Remove a cfattach from the specified driver.
431  */
432 int
433 config_cfattach_detach(const char *driver, struct cfattach *ca)
434 {
435 	struct cfdriver *cd;
436 	device_t dev;
437 	int i;
438 
439 	cd = config_cfdriver_lookup(driver);
440 	if (cd == NULL)
441 		return ESRCH;
442 
443 	/* Make sure there are no active instances. */
444 	for (i = 0; i < cd->cd_ndevs; i++) {
445 		if ((dev = cd->cd_devs[i]) == NULL)
446 			continue;
447 		if (dev->dv_cfattach == ca)
448 			return EBUSY;
449 	}
450 
451 	LIST_REMOVE(ca, ca_list);
452 
453 	return 0;
454 }
455 
456 /*
457  * Look up a cfattach by name.
458  */
459 static struct cfattach *
460 config_cfattach_lookup_cd(struct cfdriver *cd, const char *atname)
461 {
462 	struct cfattach *ca;
463 
464 	LIST_FOREACH(ca, &cd->cd_attach, ca_list) {
465 		if (STREQ(ca->ca_name, atname))
466 			return ca;
467 	}
468 
469 	return NULL;
470 }
471 
472 /*
473  * Look up a cfattach by driver/attachment name.
474  */
475 struct cfattach *
476 config_cfattach_lookup(const char *name, const char *atname)
477 {
478 	struct cfdriver *cd;
479 
480 	cd = config_cfdriver_lookup(name);
481 	if (cd == NULL)
482 		return NULL;
483 
484 	return config_cfattach_lookup_cd(cd, atname);
485 }
486 
487 /*
488  * Apply the matching function and choose the best.  This is used
489  * a few times and we want to keep the code small.
490  */
491 static void
492 mapply(struct matchinfo *m, cfdata_t cf)
493 {
494 	int pri;
495 
496 	if (m->fn != NULL) {
497 		pri = (*m->fn)(m->parent, cf, m->locs, m->aux);
498 	} else {
499 		pri = config_match(m->parent, cf, m->aux);
500 	}
501 	if (pri > m->pri) {
502 		m->match = cf;
503 		m->pri = pri;
504 	}
505 }
506 
507 int
508 config_stdsubmatch(device_t parent, cfdata_t cf, const int *locs, void *aux)
509 {
510 	const struct cfiattrdata *ci;
511 	const struct cflocdesc *cl;
512 	int nlocs, i;
513 
514 	ci = cfiattr_lookup(cf->cf_pspec->cfp_iattr, parent->dv_cfdriver);
515 	KASSERT(ci);
516 	nlocs = ci->ci_loclen;
517 	KASSERT(!nlocs || locs);
518 	for (i = 0; i < nlocs; i++) {
519 		cl = &ci->ci_locdesc[i];
520 		/* !cld_defaultstr means no default value */
521 		if ((!(cl->cld_defaultstr)
522 		     || (cf->cf_loc[i] != cl->cld_default))
523 		    && cf->cf_loc[i] != locs[i])
524 			return 0;
525 	}
526 
527 	return config_match(parent, cf, aux);
528 }
529 
530 /*
531  * Helper function: check whether the driver supports the interface attribute
532  * and return its descriptor structure.
533  */
534 static const struct cfiattrdata *
535 cfdriver_get_iattr(const struct cfdriver *cd, const char *ia)
536 {
537 	const struct cfiattrdata * const *cpp;
538 
539 	if (cd->cd_attrs == NULL)
540 		return 0;
541 
542 	for (cpp = cd->cd_attrs; *cpp; cpp++) {
543 		if (STREQ((*cpp)->ci_name, ia)) {
544 			/* Match. */
545 			return *cpp;
546 		}
547 	}
548 	return 0;
549 }
550 
551 /*
552  * Lookup an interface attribute description by name.
553  * If the driver is given, consider only its supported attributes.
554  */
555 const struct cfiattrdata *
556 cfiattr_lookup(const char *name, const struct cfdriver *cd)
557 {
558 	const struct cfdriver *d;
559 	const struct cfiattrdata *ia;
560 
561 	if (cd)
562 		return cfdriver_get_iattr(cd, name);
563 
564 	LIST_FOREACH(d, &allcfdrivers, cd_list) {
565 		ia = cfdriver_get_iattr(d, name);
566 		if (ia)
567 			return ia;
568 	}
569 	return 0;
570 }
571 
572 /*
573  * Determine if `parent' is a potential parent for a device spec based
574  * on `cfp'.
575  */
576 static int
577 cfparent_match(const device_t parent, const struct cfparent *cfp)
578 {
579 	struct cfdriver *pcd;
580 
581 	/* We don't match root nodes here. */
582 	if (cfp == NULL)
583 		return 0;
584 
585 	pcd = parent->dv_cfdriver;
586 	KASSERT(pcd != NULL);
587 
588 	/*
589 	 * First, ensure this parent has the correct interface
590 	 * attribute.
591 	 */
592 	if (!cfdriver_get_iattr(pcd, cfp->cfp_iattr))
593 		return 0;
594 
595 	/*
596 	 * If no specific parent device instance was specified (i.e.
597 	 * we're attaching to the attribute only), we're done!
598 	 */
599 	if (cfp->cfp_parent == NULL)
600 		return 1;
601 
602 	/*
603 	 * Check the parent device's name.
604 	 */
605 	if (STREQ(pcd->cd_name, cfp->cfp_parent) == 0)
606 		return 0;	/* not the same parent */
607 
608 	/*
609 	 * Make sure the unit number matches.
610 	 */
611 	if (cfp->cfp_unit == DVUNIT_ANY ||	/* wildcard */
612 	    cfp->cfp_unit == parent->dv_unit)
613 		return 1;
614 
615 	/* Unit numbers don't match. */
616 	return 0;
617 }
618 
619 /*
620  * Helper for config_cfdata_attach(): check all devices whether it could be
621  * parent any attachment in the config data table passed, and rescan.
622  */
623 static void
624 rescan_with_cfdata(const struct cfdata *cf)
625 {
626 	device_t d;
627 	const struct cfdata *cf1;
628 	deviter_t di;
629 
630 
631 	/*
632 	 * "alldevs" is likely longer than a modules's cfdata, so make it
633 	 * the outer loop.
634 	 */
635 	for (d = deviter_first(&di, 0); d != NULL; d = deviter_next(&di)) {
636 
637 		if (!(d->dv_cfattach->ca_rescan))
638 			continue;
639 
640 		for (cf1 = cf; cf1->cf_name; cf1++) {
641 
642 			if (!cfparent_match(d, cf1->cf_pspec))
643 				continue;
644 
645 			(*d->dv_cfattach->ca_rescan)(d,
646 				cf1->cf_pspec->cfp_iattr, cf1->cf_loc);
647 		}
648 	}
649 	deviter_release(&di);
650 }
651 
652 /*
653  * Attach a supplemental config data table and rescan potential
654  * parent devices if required.
655  */
656 int
657 config_cfdata_attach(cfdata_t cf, int scannow)
658 {
659 	struct cftable *ct;
660 
661 	ct = kmem_alloc(sizeof(*ct), KM_SLEEP);
662 	ct->ct_cfdata = cf;
663 	TAILQ_INSERT_TAIL(&allcftables, ct, ct_list);
664 
665 	if (scannow)
666 		rescan_with_cfdata(cf);
667 
668 	return 0;
669 }
670 
671 /*
672  * Helper for config_cfdata_detach: check whether a device is
673  * found through any attachment in the config data table.
674  */
675 static int
676 dev_in_cfdata(const struct device *d, const struct cfdata *cf)
677 {
678 	const struct cfdata *cf1;
679 
680 	for (cf1 = cf; cf1->cf_name; cf1++)
681 		if (d->dv_cfdata == cf1)
682 			return 1;
683 
684 	return 0;
685 }
686 
687 /*
688  * Detach a supplemental config data table. Detach all devices found
689  * through that table (and thus keeping references to it) before.
690  */
691 int
692 config_cfdata_detach(cfdata_t cf)
693 {
694 	device_t d;
695 	int error = 0;
696 	struct cftable *ct;
697 	deviter_t di;
698 
699 	for (d = deviter_first(&di, DEVITER_F_RW); d != NULL;
700 	     d = deviter_next(&di)) {
701 		if (!dev_in_cfdata(d, cf))
702 			continue;
703 		if ((error = config_detach(d, 0)) != 0)
704 			break;
705 	}
706 	deviter_release(&di);
707 	if (error) {
708 		aprint_error_dev(d, "unable to detach instance\n");
709 		return error;
710 	}
711 
712 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
713 		if (ct->ct_cfdata == cf) {
714 			TAILQ_REMOVE(&allcftables, ct, ct_list);
715 			kmem_free(ct, sizeof(*ct));
716 			return 0;
717 		}
718 	}
719 
720 	/* not found -- shouldn't happen */
721 	return EINVAL;
722 }
723 
724 /*
725  * Invoke the "match" routine for a cfdata entry on behalf of
726  * an external caller, usually a "submatch" routine.
727  */
728 int
729 config_match(device_t parent, cfdata_t cf, void *aux)
730 {
731 	struct cfattach *ca;
732 
733 	ca = config_cfattach_lookup(cf->cf_name, cf->cf_atname);
734 	if (ca == NULL) {
735 		/* No attachment for this entry, oh well. */
736 		return 0;
737 	}
738 
739 	return (*ca->ca_match)(parent, cf, aux);
740 }
741 
742 /*
743  * Iterate over all potential children of some device, calling the given
744  * function (default being the child's match function) for each one.
745  * Nonzero returns are matches; the highest value returned is considered
746  * the best match.  Return the `found child' if we got a match, or NULL
747  * otherwise.  The `aux' pointer is simply passed on through.
748  *
749  * Note that this function is designed so that it can be used to apply
750  * an arbitrary function to all potential children (its return value
751  * can be ignored).
752  */
753 cfdata_t
754 config_search_loc(cfsubmatch_t fn, device_t parent,
755 		  const char *ifattr, const int *locs, void *aux)
756 {
757 	struct cftable *ct;
758 	cfdata_t cf;
759 	struct matchinfo m;
760 
761 	KASSERT(config_initialized);
762 	KASSERT(!ifattr || cfdriver_get_iattr(parent->dv_cfdriver, ifattr));
763 
764 	m.fn = fn;
765 	m.parent = parent;
766 	m.locs = locs;
767 	m.aux = aux;
768 	m.match = NULL;
769 	m.pri = 0;
770 
771 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
772 		for (cf = ct->ct_cfdata; cf->cf_name; cf++) {
773 
774 			/* We don't match root nodes here. */
775 			if (!cf->cf_pspec)
776 				continue;
777 
778 			/*
779 			 * Skip cf if no longer eligible, otherwise scan
780 			 * through parents for one matching `parent', and
781 			 * try match function.
782 			 */
783 			if (cf->cf_fstate == FSTATE_FOUND)
784 				continue;
785 			if (cf->cf_fstate == FSTATE_DNOTFOUND ||
786 			    cf->cf_fstate == FSTATE_DSTAR)
787 				continue;
788 
789 			/*
790 			 * If an interface attribute was specified,
791 			 * consider only children which attach to
792 			 * that attribute.
793 			 */
794 			if (ifattr && !STREQ(ifattr, cf->cf_pspec->cfp_iattr))
795 				continue;
796 
797 			if (cfparent_match(parent, cf->cf_pspec))
798 				mapply(&m, cf);
799 		}
800 	}
801 	return m.match;
802 }
803 
804 cfdata_t
805 config_search_ia(cfsubmatch_t fn, device_t parent, const char *ifattr,
806     void *aux)
807 {
808 
809 	return config_search_loc(fn, parent, ifattr, NULL, aux);
810 }
811 
812 /*
813  * Find the given root device.
814  * This is much like config_search, but there is no parent.
815  * Don't bother with multiple cfdata tables; the root node
816  * must always be in the initial table.
817  */
818 cfdata_t
819 config_rootsearch(cfsubmatch_t fn, const char *rootname, void *aux)
820 {
821 	cfdata_t cf;
822 	const short *p;
823 	struct matchinfo m;
824 
825 	m.fn = fn;
826 	m.parent = ROOT;
827 	m.aux = aux;
828 	m.match = NULL;
829 	m.pri = 0;
830 	m.locs = 0;
831 	/*
832 	 * Look at root entries for matching name.  We do not bother
833 	 * with found-state here since only one root should ever be
834 	 * searched (and it must be done first).
835 	 */
836 	for (p = cfroots; *p >= 0; p++) {
837 		cf = &cfdata[*p];
838 		if (strcmp(cf->cf_name, rootname) == 0)
839 			mapply(&m, cf);
840 	}
841 	return m.match;
842 }
843 
844 static const char * const msgs[3] = { "", " not configured\n", " unsupported\n" };
845 
846 /*
847  * The given `aux' argument describes a device that has been found
848  * on the given parent, but not necessarily configured.  Locate the
849  * configuration data for that device (using the submatch function
850  * provided, or using candidates' cd_match configuration driver
851  * functions) and attach it, and return true.  If the device was
852  * not configured, call the given `print' function and return 0.
853  */
854 device_t
855 config_found_sm_loc(device_t parent,
856 		const char *ifattr, const int *locs, void *aux,
857 		cfprint_t print, cfsubmatch_t submatch)
858 {
859 	cfdata_t cf;
860 
861 #if defined(SPLASHSCREEN) && defined(SPLASHSCREEN_PROGRESS)
862 	if (splash_progress_state)
863 		splash_progress_update(splash_progress_state);
864 #endif
865 
866 	if ((cf = config_search_loc(submatch, parent, ifattr, locs, aux)))
867 		return(config_attach_loc(parent, cf, locs, aux, print));
868 	if (print) {
869 		if (config_do_twiddle && cold)
870 			twiddle();
871 		aprint_normal("%s", msgs[(*print)(aux, device_xname(parent))]);
872 	}
873 
874 #if defined(SPLASHSCREEN) && defined(SPLASHSCREEN_PROGRESS)
875 	if (splash_progress_state)
876 		splash_progress_update(splash_progress_state);
877 #endif
878 
879 	return NULL;
880 }
881 
882 device_t
883 config_found_ia(device_t parent, const char *ifattr, void *aux,
884     cfprint_t print)
885 {
886 
887 	return config_found_sm_loc(parent, ifattr, NULL, aux, print, NULL);
888 }
889 
890 device_t
891 config_found(device_t parent, void *aux, cfprint_t print)
892 {
893 
894 	return config_found_sm_loc(parent, NULL, NULL, aux, print, NULL);
895 }
896 
897 /*
898  * As above, but for root devices.
899  */
900 device_t
901 config_rootfound(const char *rootname, void *aux)
902 {
903 	cfdata_t cf;
904 
905 	if ((cf = config_rootsearch((cfsubmatch_t)NULL, rootname, aux)) != NULL)
906 		return config_attach(ROOT, cf, aux, (cfprint_t)NULL);
907 	aprint_error("root device %s not configured\n", rootname);
908 	return NULL;
909 }
910 
911 /* just like sprintf(buf, "%d") except that it works from the end */
912 static char *
913 number(char *ep, int n)
914 {
915 
916 	*--ep = 0;
917 	while (n >= 10) {
918 		*--ep = (n % 10) + '0';
919 		n /= 10;
920 	}
921 	*--ep = n + '0';
922 	return ep;
923 }
924 
925 /*
926  * Expand the size of the cd_devs array if necessary.
927  */
928 static void
929 config_makeroom(int n, struct cfdriver *cd)
930 {
931 	int old, new;
932 	device_t *nsp;
933 
934 	if (n < cd->cd_ndevs)
935 		return;
936 
937 	/*
938 	 * Need to expand the array.
939 	 */
940 	old = cd->cd_ndevs;
941 	if (old == 0)
942 		new = 4;
943 	else
944 		new = old * 2;
945 	while (new <= n)
946 		new *= 2;
947 	cd->cd_ndevs = new;
948 	nsp = kmem_alloc(sizeof(device_t [new]), KM_SLEEP);
949 	if (nsp == NULL)
950 		panic("config_attach: %sing dev array",
951 		    old != 0 ? "expand" : "creat");
952 	memset(nsp + old, 0, sizeof(device_t [new - old]));
953 	if (old != 0) {
954 		memcpy(nsp, cd->cd_devs, sizeof(device_t [old]));
955 		kmem_free(cd->cd_devs, sizeof(device_t [old]));
956 	}
957 	cd->cd_devs = nsp;
958 }
959 
960 static void
961 config_devlink(device_t dev)
962 {
963 	struct cfdriver *cd = dev->dv_cfdriver;
964 
965 	/* put this device in the devices array */
966 	config_makeroom(dev->dv_unit, cd);
967 	if (cd->cd_devs[dev->dv_unit])
968 		panic("config_attach: duplicate %s", device_xname(dev));
969 	cd->cd_devs[dev->dv_unit] = dev;
970 
971 	/* It is safe to add a device to the tail of the list while
972 	 * readers are in the list, but not while a writer is in
973 	 * the list.  Wait for any writer to complete.
974 	 */
975 	mutex_enter(&alldevs_mtx);
976 	while (alldevs_nwrite != 0 && alldevs_writer != curlwp)
977 		cv_wait(&alldevs_cv, &alldevs_mtx);
978 	TAILQ_INSERT_TAIL(&alldevs, dev, dv_list);	/* link up */
979 	cv_signal(&alldevs_cv);
980 	mutex_exit(&alldevs_mtx);
981 }
982 
983 static void
984 config_devunlink(device_t dev)
985 {
986 	struct cfdriver *cd = dev->dv_cfdriver;
987 	int i;
988 
989 	/* Unlink from device list. */
990 	TAILQ_REMOVE(&alldevs, dev, dv_list);
991 
992 	/* Remove from cfdriver's array. */
993 	cd->cd_devs[dev->dv_unit] = NULL;
994 
995 	/*
996 	 * If the device now has no units in use, deallocate its softc array.
997 	 */
998 	for (i = 0; i < cd->cd_ndevs; i++) {
999 		if (cd->cd_devs[i] != NULL)
1000 			return;
1001 	}
1002 	/* nothing found; deallocate */
1003 	kmem_free(cd->cd_devs, sizeof(device_t [cd->cd_ndevs]));
1004 	cd->cd_devs = NULL;
1005 	cd->cd_ndevs = 0;
1006 }
1007 
1008 static device_t
1009 config_devalloc(const device_t parent, const cfdata_t cf, const int *locs)
1010 {
1011 	struct cfdriver *cd;
1012 	struct cfattach *ca;
1013 	size_t lname, lunit;
1014 	const char *xunit;
1015 	int myunit;
1016 	char num[10];
1017 	device_t dev;
1018 	void *dev_private;
1019 	const struct cfiattrdata *ia;
1020 	device_lock_t dvl;
1021 
1022 	cd = config_cfdriver_lookup(cf->cf_name);
1023 	if (cd == NULL)
1024 		return NULL;
1025 
1026 	ca = config_cfattach_lookup_cd(cd, cf->cf_atname);
1027 	if (ca == NULL)
1028 		return NULL;
1029 
1030 	if ((ca->ca_flags & DVF_PRIV_ALLOC) == 0 &&
1031 	    ca->ca_devsize < sizeof(struct device))
1032 		panic("config_devalloc: %s", cf->cf_atname);
1033 
1034 #ifndef __BROKEN_CONFIG_UNIT_USAGE
1035 	if (cf->cf_fstate == FSTATE_STAR) {
1036 		for (myunit = cf->cf_unit; myunit < cd->cd_ndevs; myunit++)
1037 			if (cd->cd_devs[myunit] == NULL)
1038 				break;
1039 		/*
1040 		 * myunit is now the unit of the first NULL device pointer,
1041 		 * or max(cd->cd_ndevs,cf->cf_unit).
1042 		 */
1043 	} else {
1044 		myunit = cf->cf_unit;
1045 		if (myunit < cd->cd_ndevs && cd->cd_devs[myunit] != NULL)
1046 			return NULL;
1047 	}
1048 #else
1049 	myunit = cf->cf_unit;
1050 #endif /* ! __BROKEN_CONFIG_UNIT_USAGE */
1051 
1052 	/* compute length of name and decimal expansion of unit number */
1053 	lname = strlen(cd->cd_name);
1054 	xunit = number(&num[sizeof(num)], myunit);
1055 	lunit = &num[sizeof(num)] - xunit;
1056 	if (lname + lunit > sizeof(dev->dv_xname))
1057 		panic("config_devalloc: device name too long");
1058 
1059 	/* get memory for all device vars */
1060 	KASSERT((ca->ca_flags & DVF_PRIV_ALLOC) || ca->ca_devsize >= sizeof(struct device));
1061 	if (ca->ca_devsize > 0) {
1062 		dev_private = kmem_zalloc(ca->ca_devsize, KM_SLEEP);
1063 		if (dev_private == NULL)
1064 			panic("config_devalloc: memory allocation for device softc failed");
1065 	} else {
1066 		KASSERT(ca->ca_flags & DVF_PRIV_ALLOC);
1067 		dev_private = NULL;
1068 	}
1069 
1070 	if ((ca->ca_flags & DVF_PRIV_ALLOC) != 0) {
1071 		dev = kmem_zalloc(sizeof(*dev), KM_SLEEP);
1072 	} else {
1073 		dev = dev_private;
1074 	}
1075 	if (dev == NULL)
1076 		panic("config_devalloc: memory allocation for device_t failed");
1077 
1078 	dvl = device_getlock(dev);
1079 
1080 	mutex_init(&dvl->dvl_mtx, MUTEX_DEFAULT, IPL_NONE);
1081 	cv_init(&dvl->dvl_cv, "pmfsusp");
1082 
1083 	dev->dv_class = cd->cd_class;
1084 	dev->dv_cfdata = cf;
1085 	dev->dv_cfdriver = cd;
1086 	dev->dv_cfattach = ca;
1087 	dev->dv_unit = myunit;
1088 	dev->dv_activity_count = 0;
1089 	dev->dv_activity_handlers = NULL;
1090 	dev->dv_private = dev_private;
1091 	memcpy(dev->dv_xname, cd->cd_name, lname);
1092 	memcpy(dev->dv_xname + lname, xunit, lunit);
1093 	dev->dv_parent = parent;
1094 	if (parent != NULL)
1095 		dev->dv_depth = parent->dv_depth + 1;
1096 	else
1097 		dev->dv_depth = 0;
1098 	dev->dv_flags = DVF_ACTIVE;	/* always initially active */
1099 	dev->dv_flags |= ca->ca_flags;	/* inherit flags from class */
1100 	if (locs) {
1101 		KASSERT(parent); /* no locators at root */
1102 		ia = cfiattr_lookup(cf->cf_pspec->cfp_iattr,
1103 				    parent->dv_cfdriver);
1104 		dev->dv_locators =
1105 		    kmem_alloc(sizeof(int [ia->ci_loclen + 1]), KM_SLEEP);
1106 		*dev->dv_locators++ = sizeof(int [ia->ci_loclen + 1]);
1107 		memcpy(dev->dv_locators, locs, sizeof(int [ia->ci_loclen]));
1108 	}
1109 	dev->dv_properties = prop_dictionary_create();
1110 	KASSERT(dev->dv_properties != NULL);
1111 
1112 	prop_dictionary_set_cstring_nocopy(dev->dv_properties,
1113 	    "device-driver", dev->dv_cfdriver->cd_name);
1114 	prop_dictionary_set_uint16(dev->dv_properties,
1115 	    "device-unit", dev->dv_unit);
1116 
1117 	return dev;
1118 }
1119 
1120 static void
1121 config_devdealloc(device_t dev)
1122 {
1123 	device_lock_t dvl = device_getlock(dev);
1124 	int priv = (dev->dv_flags & DVF_PRIV_ALLOC);
1125 
1126 	cv_destroy(&dvl->dvl_cv);
1127 	mutex_destroy(&dvl->dvl_mtx);
1128 
1129 	KASSERT(dev->dv_properties != NULL);
1130 	prop_object_release(dev->dv_properties);
1131 
1132 	if (dev->dv_activity_handlers)
1133 		panic("config_devdealloc with registered handlers");
1134 
1135 	if (dev->dv_locators) {
1136 		size_t amount = *--dev->dv_locators;
1137 		kmem_free(dev->dv_locators, amount);
1138 	}
1139 
1140 	if (dev->dv_cfattach->ca_devsize > 0)
1141 		kmem_free(dev->dv_private, dev->dv_cfattach->ca_devsize);
1142 	if (priv)
1143 		kmem_free(dev, sizeof(*dev));
1144 }
1145 
1146 /*
1147  * Attach a found device.
1148  */
1149 device_t
1150 config_attach_loc(device_t parent, cfdata_t cf,
1151 	const int *locs, void *aux, cfprint_t print)
1152 {
1153 	device_t dev;
1154 	struct cftable *ct;
1155 	const char *drvname;
1156 
1157 #if defined(SPLASHSCREEN) && defined(SPLASHSCREEN_PROGRESS)
1158 	if (splash_progress_state)
1159 		splash_progress_update(splash_progress_state);
1160 #endif
1161 
1162 	dev = config_devalloc(parent, cf, locs);
1163 	if (!dev)
1164 		panic("config_attach: allocation of device softc failed");
1165 
1166 	/* XXX redundant - see below? */
1167 	if (cf->cf_fstate != FSTATE_STAR) {
1168 		KASSERT(cf->cf_fstate == FSTATE_NOTFOUND);
1169 		cf->cf_fstate = FSTATE_FOUND;
1170 	}
1171 #ifdef __BROKEN_CONFIG_UNIT_USAGE
1172 	  else
1173 		cf->cf_unit++;
1174 #endif
1175 
1176 	config_devlink(dev);
1177 
1178 	if (config_do_twiddle && cold)
1179 		twiddle();
1180 	else
1181 		aprint_naive("Found ");
1182 	/*
1183 	 * We want the next two printfs for normal, verbose, and quiet,
1184 	 * but not silent (in which case, we're twiddling, instead).
1185 	 */
1186 	if (parent == ROOT) {
1187 		aprint_naive("%s (root)", device_xname(dev));
1188 		aprint_normal("%s (root)", device_xname(dev));
1189 	} else {
1190 		aprint_naive("%s at %s", device_xname(dev), device_xname(parent));
1191 		aprint_normal("%s at %s", device_xname(dev), device_xname(parent));
1192 		if (print)
1193 			(void) (*print)(aux, NULL);
1194 	}
1195 
1196 	/*
1197 	 * Before attaching, clobber any unfound devices that are
1198 	 * otherwise identical.
1199 	 * XXX code above is redundant?
1200 	 */
1201 	drvname = dev->dv_cfdriver->cd_name;
1202 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
1203 		for (cf = ct->ct_cfdata; cf->cf_name; cf++) {
1204 			if (STREQ(cf->cf_name, drvname) &&
1205 			    cf->cf_unit == dev->dv_unit) {
1206 				if (cf->cf_fstate == FSTATE_NOTFOUND)
1207 					cf->cf_fstate = FSTATE_FOUND;
1208 #ifdef __BROKEN_CONFIG_UNIT_USAGE
1209 				/*
1210 				 * Bump the unit number on all starred cfdata
1211 				 * entries for this device.
1212 				 */
1213 				if (cf->cf_fstate == FSTATE_STAR)
1214 					cf->cf_unit++;
1215 #endif /* __BROKEN_CONFIG_UNIT_USAGE */
1216 			}
1217 		}
1218 	}
1219 #ifdef __HAVE_DEVICE_REGISTER
1220 	device_register(dev, aux);
1221 #endif
1222 
1223 	/* Let userland know */
1224 	devmon_report_device(dev, true);
1225 
1226 #if defined(SPLASHSCREEN) && defined(SPLASHSCREEN_PROGRESS)
1227 	if (splash_progress_state)
1228 		splash_progress_update(splash_progress_state);
1229 #endif
1230 	(*dev->dv_cfattach->ca_attach)(parent, dev, aux);
1231 #if defined(SPLASHSCREEN) && defined(SPLASHSCREEN_PROGRESS)
1232 	if (splash_progress_state)
1233 		splash_progress_update(splash_progress_state);
1234 #endif
1235 
1236 	if (!device_pmf_is_registered(dev))
1237 		aprint_debug_dev(dev, "WARNING: power management not supported\n");
1238 
1239 	config_process_deferred(&deferred_config_queue, dev);
1240 	return dev;
1241 }
1242 
1243 device_t
1244 config_attach(device_t parent, cfdata_t cf, void *aux, cfprint_t print)
1245 {
1246 
1247 	return config_attach_loc(parent, cf, NULL, aux, print);
1248 }
1249 
1250 /*
1251  * As above, but for pseudo-devices.  Pseudo-devices attached in this
1252  * way are silently inserted into the device tree, and their children
1253  * attached.
1254  *
1255  * Note that because pseudo-devices are attached silently, any information
1256  * the attach routine wishes to print should be prefixed with the device
1257  * name by the attach routine.
1258  */
1259 device_t
1260 config_attach_pseudo(cfdata_t cf)
1261 {
1262 	device_t dev;
1263 
1264 	dev = config_devalloc(ROOT, cf, NULL);
1265 	if (!dev)
1266 		return NULL;
1267 
1268 	/* XXX mark busy in cfdata */
1269 
1270 	if (cf->cf_fstate != FSTATE_STAR) {
1271 		KASSERT(cf->cf_fstate == FSTATE_NOTFOUND);
1272 		cf->cf_fstate = FSTATE_FOUND;
1273 	}
1274 
1275 	config_devlink(dev);
1276 
1277 #if 0	/* XXXJRT not yet */
1278 #ifdef __HAVE_DEVICE_REGISTER
1279 	device_register(dev, NULL);	/* like a root node */
1280 #endif
1281 #endif
1282 	(*dev->dv_cfattach->ca_attach)(ROOT, dev, NULL);
1283 	config_process_deferred(&deferred_config_queue, dev);
1284 	return dev;
1285 }
1286 
1287 /*
1288  * Detach a device.  Optionally forced (e.g. because of hardware
1289  * removal) and quiet.  Returns zero if successful, non-zero
1290  * (an error code) otherwise.
1291  *
1292  * Note that this code wants to be run from a process context, so
1293  * that the detach can sleep to allow processes which have a device
1294  * open to run and unwind their stacks.
1295  */
1296 int
1297 config_detach(device_t dev, int flags)
1298 {
1299 	struct cftable *ct;
1300 	cfdata_t cf;
1301 	const struct cfattach *ca;
1302 	struct cfdriver *cd;
1303 #ifdef DIAGNOSTIC
1304 	device_t d;
1305 #endif
1306 	int rv = 0;
1307 
1308 #ifdef DIAGNOSTIC
1309 	cf = dev->dv_cfdata;
1310 	if (cf != NULL && cf->cf_fstate != FSTATE_FOUND &&
1311 	    cf->cf_fstate != FSTATE_STAR)
1312 		panic("config_detach: %s: bad device fstate %d",
1313 		    device_xname(dev), cf ? cf->cf_fstate : -1);
1314 #endif
1315 	cd = dev->dv_cfdriver;
1316 	KASSERT(cd != NULL);
1317 
1318 	ca = dev->dv_cfattach;
1319 	KASSERT(ca != NULL);
1320 
1321 	KASSERT(curlwp != NULL);
1322 	mutex_enter(&alldevs_mtx);
1323 	if (alldevs_nwrite > 0 && alldevs_writer == NULL)
1324 		;
1325 	else while (alldevs_nread != 0 ||
1326 	       (alldevs_nwrite != 0 && alldevs_writer != curlwp))
1327 		cv_wait(&alldevs_cv, &alldevs_mtx);
1328 	if (alldevs_nwrite++ == 0)
1329 		alldevs_writer = curlwp;
1330 	mutex_exit(&alldevs_mtx);
1331 
1332 	/*
1333 	 * Ensure the device is deactivated.  If the device doesn't
1334 	 * have an activation entry point, we allow DVF_ACTIVE to
1335 	 * remain set.  Otherwise, if DVF_ACTIVE is still set, the
1336 	 * device is busy, and the detach fails.
1337 	 */
1338 	if (!detachall &&
1339 	    (flags & (DETACH_SHUTDOWN|DETACH_FORCE)) == DETACH_SHUTDOWN &&
1340 	    (dev->dv_flags & DVF_DETACH_SHUTDOWN) == 0) {
1341 		rv = EOPNOTSUPP;
1342 	} else if ((rv = config_deactivate(dev)) == EOPNOTSUPP)
1343 		rv = 0;	/* Do not treat EOPNOTSUPP as an error */
1344 
1345 	/*
1346 	 * Try to detach the device.  If that's not possible, then
1347 	 * we either panic() (for the forced but failed case), or
1348 	 * return an error.
1349 	 */
1350 	if (rv == 0) {
1351 		if (ca->ca_detach != NULL)
1352 			rv = (*ca->ca_detach)(dev, flags);
1353 		else
1354 			rv = EOPNOTSUPP;
1355 	}
1356 	if (rv != 0) {
1357 		if ((flags & DETACH_FORCE) == 0)
1358 			goto out;
1359 		else
1360 			panic("config_detach: forced detach of %s failed (%d)",
1361 			    device_xname(dev), rv);
1362 	}
1363 
1364 	dev->dv_flags &= ~DVF_ACTIVE;
1365 
1366 	/*
1367 	 * The device has now been successfully detached.
1368 	 */
1369 
1370 	/* Let userland know */
1371 	devmon_report_device(dev, false);
1372 
1373 #ifdef DIAGNOSTIC
1374 	/*
1375 	 * Sanity: If you're successfully detached, you should have no
1376 	 * children.  (Note that because children must be attached
1377 	 * after parents, we only need to search the latter part of
1378 	 * the list.)
1379 	 */
1380 	for (d = TAILQ_NEXT(dev, dv_list); d != NULL;
1381 	    d = TAILQ_NEXT(d, dv_list)) {
1382 		if (d->dv_parent == dev) {
1383 			printf("config_detach: detached device %s"
1384 			    " has children %s\n", device_xname(dev), device_xname(d));
1385 			panic("config_detach");
1386 		}
1387 	}
1388 #endif
1389 
1390 	/* notify the parent that the child is gone */
1391 	if (dev->dv_parent) {
1392 		device_t p = dev->dv_parent;
1393 		if (p->dv_cfattach->ca_childdetached)
1394 			(*p->dv_cfattach->ca_childdetached)(p, dev);
1395 	}
1396 
1397 	/*
1398 	 * Mark cfdata to show that the unit can be reused, if possible.
1399 	 */
1400 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
1401 		for (cf = ct->ct_cfdata; cf->cf_name; cf++) {
1402 			if (STREQ(cf->cf_name, cd->cd_name)) {
1403 				if (cf->cf_fstate == FSTATE_FOUND &&
1404 				    cf->cf_unit == dev->dv_unit)
1405 					cf->cf_fstate = FSTATE_NOTFOUND;
1406 #ifdef __BROKEN_CONFIG_UNIT_USAGE
1407 				/*
1408 				 * Note that we can only re-use a starred
1409 				 * unit number if the unit being detached
1410 				 * had the last assigned unit number.
1411 				 */
1412 				if (cf->cf_fstate == FSTATE_STAR &&
1413 				    cf->cf_unit == dev->dv_unit + 1)
1414 					cf->cf_unit--;
1415 #endif /* __BROKEN_CONFIG_UNIT_USAGE */
1416 			}
1417 		}
1418 	}
1419 
1420 	config_devunlink(dev);
1421 
1422 	if (dev->dv_cfdata != NULL && (flags & DETACH_QUIET) == 0)
1423 		aprint_normal_dev(dev, "detached\n");
1424 
1425 	config_devdealloc(dev);
1426 
1427 out:
1428 	mutex_enter(&alldevs_mtx);
1429 	KASSERT(alldevs_nwrite != 0);
1430 	if (--alldevs_nwrite == 0)
1431 		alldevs_writer = NULL;
1432 	cv_signal(&alldevs_cv);
1433 	mutex_exit(&alldevs_mtx);
1434 	return rv;
1435 }
1436 
1437 int
1438 config_detach_children(device_t parent, int flags)
1439 {
1440 	device_t dv;
1441 	deviter_t di;
1442 	int error = 0;
1443 
1444 	for (dv = deviter_first(&di, DEVITER_F_RW); dv != NULL;
1445 	     dv = deviter_next(&di)) {
1446 		if (device_parent(dv) != parent)
1447 			continue;
1448 		if ((error = config_detach(dv, flags)) != 0)
1449 			break;
1450 	}
1451 	deviter_release(&di);
1452 	return error;
1453 }
1454 
1455 device_t
1456 shutdown_first(struct shutdown_state *s)
1457 {
1458 	if (!s->initialized) {
1459 		deviter_init(&s->di, DEVITER_F_SHUTDOWN|DEVITER_F_LEAVES_FIRST);
1460 		s->initialized = true;
1461 	}
1462 	return shutdown_next(s);
1463 }
1464 
1465 device_t
1466 shutdown_next(struct shutdown_state *s)
1467 {
1468 	device_t dv;
1469 
1470 	while ((dv = deviter_next(&s->di)) != NULL && !device_is_active(dv))
1471 		;
1472 
1473 	if (dv == NULL)
1474 		s->initialized = false;
1475 
1476 	return dv;
1477 }
1478 
1479 bool
1480 config_detach_all(int how)
1481 {
1482 	static struct shutdown_state s;
1483 	device_t curdev;
1484 	bool progress = false;
1485 
1486 	if ((how & RB_NOSYNC) != 0)
1487 		return false;
1488 
1489 	for (curdev = shutdown_first(&s); curdev != NULL;
1490 	     curdev = shutdown_next(&s)) {
1491 		aprint_debug(" detaching %s, ", device_xname(curdev));
1492 		if (config_detach(curdev, DETACH_SHUTDOWN) == 0) {
1493 			progress = true;
1494 			aprint_debug("success.");
1495 		} else
1496 			aprint_debug("failed.");
1497 	}
1498 	return progress;
1499 }
1500 
1501 int
1502 config_deactivate(device_t dev)
1503 {
1504 	const struct cfattach *ca = dev->dv_cfattach;
1505 	int rv = 0, oflags = dev->dv_flags;
1506 
1507 	if (ca->ca_activate == NULL)
1508 		return EOPNOTSUPP;
1509 
1510 	if (dev->dv_flags & DVF_ACTIVE) {
1511 		dev->dv_flags &= ~DVF_ACTIVE;
1512 		rv = (*ca->ca_activate)(dev, DVACT_DEACTIVATE);
1513 		if (rv)
1514 			dev->dv_flags = oflags;
1515 	}
1516 	return rv;
1517 }
1518 
1519 /*
1520  * Defer the configuration of the specified device until all
1521  * of its parent's devices have been attached.
1522  */
1523 void
1524 config_defer(device_t dev, void (*func)(device_t))
1525 {
1526 	struct deferred_config *dc;
1527 
1528 	if (dev->dv_parent == NULL)
1529 		panic("config_defer: can't defer config of a root device");
1530 
1531 #ifdef DIAGNOSTIC
1532 	for (dc = TAILQ_FIRST(&deferred_config_queue); dc != NULL;
1533 	     dc = TAILQ_NEXT(dc, dc_queue)) {
1534 		if (dc->dc_dev == dev)
1535 			panic("config_defer: deferred twice");
1536 	}
1537 #endif
1538 
1539 	dc = kmem_alloc(sizeof(*dc), KM_SLEEP);
1540 	if (dc == NULL)
1541 		panic("config_defer: unable to allocate callback");
1542 
1543 	dc->dc_dev = dev;
1544 	dc->dc_func = func;
1545 	TAILQ_INSERT_TAIL(&deferred_config_queue, dc, dc_queue);
1546 	config_pending_incr();
1547 }
1548 
1549 /*
1550  * Defer some autoconfiguration for a device until after interrupts
1551  * are enabled.
1552  */
1553 void
1554 config_interrupts(device_t dev, void (*func)(device_t))
1555 {
1556 	struct deferred_config *dc;
1557 
1558 	/*
1559 	 * If interrupts are enabled, callback now.
1560 	 */
1561 	if (cold == 0) {
1562 		(*func)(dev);
1563 		return;
1564 	}
1565 
1566 #ifdef DIAGNOSTIC
1567 	for (dc = TAILQ_FIRST(&interrupt_config_queue); dc != NULL;
1568 	     dc = TAILQ_NEXT(dc, dc_queue)) {
1569 		if (dc->dc_dev == dev)
1570 			panic("config_interrupts: deferred twice");
1571 	}
1572 #endif
1573 
1574 	dc = kmem_alloc(sizeof(*dc), KM_SLEEP);
1575 	if (dc == NULL)
1576 		panic("config_interrupts: unable to allocate callback");
1577 
1578 	dc->dc_dev = dev;
1579 	dc->dc_func = func;
1580 	TAILQ_INSERT_TAIL(&interrupt_config_queue, dc, dc_queue);
1581 	config_pending_incr();
1582 }
1583 
1584 /*
1585  * Process a deferred configuration queue.
1586  */
1587 static void
1588 config_process_deferred(struct deferred_config_head *queue,
1589     device_t parent)
1590 {
1591 	struct deferred_config *dc, *ndc;
1592 
1593 	for (dc = TAILQ_FIRST(queue); dc != NULL; dc = ndc) {
1594 		ndc = TAILQ_NEXT(dc, dc_queue);
1595 		if (parent == NULL || dc->dc_dev->dv_parent == parent) {
1596 			TAILQ_REMOVE(queue, dc, dc_queue);
1597 			(*dc->dc_func)(dc->dc_dev);
1598 			kmem_free(dc, sizeof(*dc));
1599 			config_pending_decr();
1600 		}
1601 	}
1602 }
1603 
1604 /*
1605  * Manipulate the config_pending semaphore.
1606  */
1607 void
1608 config_pending_incr(void)
1609 {
1610 
1611 	mutex_enter(&config_misc_lock);
1612 	config_pending++;
1613 	mutex_exit(&config_misc_lock);
1614 }
1615 
1616 void
1617 config_pending_decr(void)
1618 {
1619 
1620 #ifdef DIAGNOSTIC
1621 	if (config_pending == 0)
1622 		panic("config_pending_decr: config_pending == 0");
1623 #endif
1624 	mutex_enter(&config_misc_lock);
1625 	config_pending--;
1626 	if (config_pending == 0)
1627 		cv_broadcast(&config_misc_cv);
1628 	mutex_exit(&config_misc_lock);
1629 }
1630 
1631 /*
1632  * Register a "finalization" routine.  Finalization routines are
1633  * called iteratively once all real devices have been found during
1634  * autoconfiguration, for as long as any one finalizer has done
1635  * any work.
1636  */
1637 int
1638 config_finalize_register(device_t dev, int (*fn)(device_t))
1639 {
1640 	struct finalize_hook *f;
1641 
1642 	/*
1643 	 * If finalization has already been done, invoke the
1644 	 * callback function now.
1645 	 */
1646 	if (config_finalize_done) {
1647 		while ((*fn)(dev) != 0)
1648 			/* loop */ ;
1649 	}
1650 
1651 	/* Ensure this isn't already on the list. */
1652 	TAILQ_FOREACH(f, &config_finalize_list, f_list) {
1653 		if (f->f_func == fn && f->f_dev == dev)
1654 			return EEXIST;
1655 	}
1656 
1657 	f = kmem_alloc(sizeof(*f), KM_SLEEP);
1658 	f->f_func = fn;
1659 	f->f_dev = dev;
1660 	TAILQ_INSERT_TAIL(&config_finalize_list, f, f_list);
1661 
1662 	return 0;
1663 }
1664 
1665 void
1666 config_finalize(void)
1667 {
1668 	struct finalize_hook *f;
1669 	struct pdevinit *pdev;
1670 	extern struct pdevinit pdevinit[];
1671 	int errcnt, rv;
1672 
1673 	/*
1674 	 * Now that device driver threads have been created, wait for
1675 	 * them to finish any deferred autoconfiguration.
1676 	 */
1677 	mutex_enter(&config_misc_lock);
1678 	while (config_pending != 0)
1679 		cv_wait(&config_misc_cv, &config_misc_lock);
1680 	mutex_exit(&config_misc_lock);
1681 
1682 	KERNEL_LOCK(1, NULL);
1683 
1684 	/* Attach pseudo-devices. */
1685 	for (pdev = pdevinit; pdev->pdev_attach != NULL; pdev++)
1686 		(*pdev->pdev_attach)(pdev->pdev_count);
1687 
1688 	/* Run the hooks until none of them does any work. */
1689 	do {
1690 		rv = 0;
1691 		TAILQ_FOREACH(f, &config_finalize_list, f_list)
1692 			rv |= (*f->f_func)(f->f_dev);
1693 	} while (rv != 0);
1694 
1695 	config_finalize_done = 1;
1696 
1697 	/* Now free all the hooks. */
1698 	while ((f = TAILQ_FIRST(&config_finalize_list)) != NULL) {
1699 		TAILQ_REMOVE(&config_finalize_list, f, f_list);
1700 		kmem_free(f, sizeof(*f));
1701 	}
1702 
1703 	KERNEL_UNLOCK_ONE(NULL);
1704 
1705 	errcnt = aprint_get_error_count();
1706 	if ((boothowto & (AB_QUIET|AB_SILENT)) != 0 &&
1707 	    (boothowto & AB_VERBOSE) == 0) {
1708 		mutex_enter(&config_misc_lock);
1709 		if (config_do_twiddle) {
1710 			config_do_twiddle = 0;
1711 			printf_nolog(" done.\n");
1712 		}
1713 		mutex_exit(&config_misc_lock);
1714 		if (errcnt != 0) {
1715 			printf("WARNING: %d error%s while detecting hardware; "
1716 			    "check system log.\n", errcnt,
1717 			    errcnt == 1 ? "" : "s");
1718 		}
1719 	}
1720 }
1721 
1722 void
1723 config_twiddle_init()
1724 {
1725 
1726 	if ((boothowto & (AB_SILENT|AB_VERBOSE)) == AB_SILENT) {
1727 		config_do_twiddle = 1;
1728 	}
1729 	callout_setfunc(&config_twiddle_ch, config_twiddle_fn, NULL);
1730 }
1731 
1732 void
1733 config_twiddle_fn(void *cookie)
1734 {
1735 
1736 	mutex_enter(&config_misc_lock);
1737 	if (config_do_twiddle) {
1738 		twiddle();
1739 		callout_schedule(&config_twiddle_ch, mstohz(100));
1740 	}
1741 	mutex_exit(&config_misc_lock);
1742 }
1743 
1744 /*
1745  * device_lookup:
1746  *
1747  *	Look up a device instance for a given driver.
1748  */
1749 device_t
1750 device_lookup(cfdriver_t cd, int unit)
1751 {
1752 
1753 	if (unit < 0 || unit >= cd->cd_ndevs)
1754 		return NULL;
1755 
1756 	return cd->cd_devs[unit];
1757 }
1758 
1759 /*
1760  * device_lookup:
1761  *
1762  *	Look up a device instance for a given driver.
1763  */
1764 void *
1765 device_lookup_private(cfdriver_t cd, int unit)
1766 {
1767 	device_t dv;
1768 
1769 	if (unit < 0 || unit >= cd->cd_ndevs)
1770 		return NULL;
1771 
1772 	if ((dv = cd->cd_devs[unit]) == NULL)
1773 		return NULL;
1774 
1775 	return dv->dv_private;
1776 }
1777 
1778 /*
1779  * Accessor functions for the device_t type.
1780  */
1781 devclass_t
1782 device_class(device_t dev)
1783 {
1784 
1785 	return dev->dv_class;
1786 }
1787 
1788 cfdata_t
1789 device_cfdata(device_t dev)
1790 {
1791 
1792 	return dev->dv_cfdata;
1793 }
1794 
1795 cfdriver_t
1796 device_cfdriver(device_t dev)
1797 {
1798 
1799 	return dev->dv_cfdriver;
1800 }
1801 
1802 cfattach_t
1803 device_cfattach(device_t dev)
1804 {
1805 
1806 	return dev->dv_cfattach;
1807 }
1808 
1809 int
1810 device_unit(device_t dev)
1811 {
1812 
1813 	return dev->dv_unit;
1814 }
1815 
1816 const char *
1817 device_xname(device_t dev)
1818 {
1819 
1820 	return dev->dv_xname;
1821 }
1822 
1823 device_t
1824 device_parent(device_t dev)
1825 {
1826 
1827 	return dev->dv_parent;
1828 }
1829 
1830 bool
1831 device_activation(device_t dev, devact_level_t level)
1832 {
1833 	int active_flags;
1834 
1835 	active_flags = DVF_ACTIVE;
1836 	switch (level) {
1837 	case DEVACT_LEVEL_FULL:
1838 		active_flags |= DVF_CLASS_SUSPENDED;
1839 		/*FALLTHROUGH*/
1840 	case DEVACT_LEVEL_DRIVER:
1841 		active_flags |= DVF_DRIVER_SUSPENDED;
1842 		/*FALLTHROUGH*/
1843 	case DEVACT_LEVEL_BUS:
1844 		active_flags |= DVF_BUS_SUSPENDED;
1845 		break;
1846 	}
1847 
1848 	return (dev->dv_flags & active_flags) == DVF_ACTIVE;
1849 }
1850 
1851 bool
1852 device_is_active(device_t dev)
1853 {
1854 	int active_flags;
1855 
1856 	active_flags = DVF_ACTIVE;
1857 	active_flags |= DVF_CLASS_SUSPENDED;
1858 	active_flags |= DVF_DRIVER_SUSPENDED;
1859 	active_flags |= DVF_BUS_SUSPENDED;
1860 
1861 	return (dev->dv_flags & active_flags) == DVF_ACTIVE;
1862 }
1863 
1864 bool
1865 device_is_enabled(device_t dev)
1866 {
1867 	return (dev->dv_flags & DVF_ACTIVE) == DVF_ACTIVE;
1868 }
1869 
1870 bool
1871 device_has_power(device_t dev)
1872 {
1873 	int active_flags;
1874 
1875 	active_flags = DVF_ACTIVE | DVF_BUS_SUSPENDED;
1876 
1877 	return (dev->dv_flags & active_flags) == DVF_ACTIVE;
1878 }
1879 
1880 int
1881 device_locator(device_t dev, u_int locnum)
1882 {
1883 
1884 	KASSERT(dev->dv_locators != NULL);
1885 	return dev->dv_locators[locnum];
1886 }
1887 
1888 void *
1889 device_private(device_t dev)
1890 {
1891 
1892 	/*
1893 	 * The reason why device_private(NULL) is allowed is to simplify the
1894 	 * work of a lot of userspace request handlers (i.e., c/bdev
1895 	 * handlers) which grab cfdriver_t->cd_units[n].
1896 	 * It avoids having them test for it to be NULL and only then calling
1897 	 * device_private.
1898 	 */
1899 	return dev == NULL ? NULL : dev->dv_private;
1900 }
1901 
1902 prop_dictionary_t
1903 device_properties(device_t dev)
1904 {
1905 
1906 	return dev->dv_properties;
1907 }
1908 
1909 /*
1910  * device_is_a:
1911  *
1912  *	Returns true if the device is an instance of the specified
1913  *	driver.
1914  */
1915 bool
1916 device_is_a(device_t dev, const char *dname)
1917 {
1918 
1919 	return strcmp(dev->dv_cfdriver->cd_name, dname) == 0;
1920 }
1921 
1922 /*
1923  * device_find_by_xname:
1924  *
1925  *	Returns the device of the given name or NULL if it doesn't exist.
1926  */
1927 device_t
1928 device_find_by_xname(const char *name)
1929 {
1930 	device_t dv;
1931 	deviter_t di;
1932 
1933 	for (dv = deviter_first(&di, 0); dv != NULL; dv = deviter_next(&di)) {
1934 		if (strcmp(device_xname(dv), name) == 0)
1935 			break;
1936 	}
1937 	deviter_release(&di);
1938 
1939 	return dv;
1940 }
1941 
1942 /*
1943  * device_find_by_driver_unit:
1944  *
1945  *	Returns the device of the given driver name and unit or
1946  *	NULL if it doesn't exist.
1947  */
1948 device_t
1949 device_find_by_driver_unit(const char *name, int unit)
1950 {
1951 	struct cfdriver *cd;
1952 
1953 	if ((cd = config_cfdriver_lookup(name)) == NULL)
1954 		return NULL;
1955 	return device_lookup(cd, unit);
1956 }
1957 
1958 /*
1959  * Power management related functions.
1960  */
1961 
1962 bool
1963 device_pmf_is_registered(device_t dev)
1964 {
1965 	return (dev->dv_flags & DVF_POWER_HANDLERS) != 0;
1966 }
1967 
1968 bool
1969 device_pmf_driver_suspend(device_t dev PMF_FN_ARGS)
1970 {
1971 	if ((dev->dv_flags & DVF_DRIVER_SUSPENDED) != 0)
1972 		return true;
1973 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) == 0)
1974 		return false;
1975 	if (pmf_qual_depth(PMF_FN_CALL1) <= DEVACT_LEVEL_DRIVER &&
1976 	    dev->dv_driver_suspend != NULL &&
1977 	    !(*dev->dv_driver_suspend)(dev PMF_FN_CALL))
1978 		return false;
1979 
1980 	dev->dv_flags |= DVF_DRIVER_SUSPENDED;
1981 	return true;
1982 }
1983 
1984 bool
1985 device_pmf_driver_resume(device_t dev PMF_FN_ARGS)
1986 {
1987 	if ((dev->dv_flags & DVF_DRIVER_SUSPENDED) == 0)
1988 		return true;
1989 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) != 0)
1990 		return false;
1991 	if (pmf_qual_depth(PMF_FN_CALL1) <= DEVACT_LEVEL_DRIVER &&
1992 	    dev->dv_driver_resume != NULL &&
1993 	    !(*dev->dv_driver_resume)(dev PMF_FN_CALL))
1994 		return false;
1995 
1996 	dev->dv_flags &= ~DVF_DRIVER_SUSPENDED;
1997 	return true;
1998 }
1999 
2000 bool
2001 device_pmf_driver_shutdown(device_t dev, int how)
2002 {
2003 
2004 	if (*dev->dv_driver_shutdown != NULL &&
2005 	    !(*dev->dv_driver_shutdown)(dev, how))
2006 		return false;
2007 	return true;
2008 }
2009 
2010 bool
2011 device_pmf_driver_register(device_t dev,
2012     bool (*suspend)(device_t PMF_FN_PROTO),
2013     bool (*resume)(device_t PMF_FN_PROTO),
2014     bool (*shutdown)(device_t, int))
2015 {
2016 	dev->dv_driver_suspend = suspend;
2017 	dev->dv_driver_resume = resume;
2018 	dev->dv_driver_shutdown = shutdown;
2019 	dev->dv_flags |= DVF_POWER_HANDLERS;
2020 	return true;
2021 }
2022 
2023 static const char *
2024 curlwp_name(void)
2025 {
2026 	if (curlwp->l_name != NULL)
2027 		return curlwp->l_name;
2028 	else
2029 		return curlwp->l_proc->p_comm;
2030 }
2031 
2032 void
2033 device_pmf_driver_deregister(device_t dev)
2034 {
2035 	device_lock_t dvl = device_getlock(dev);
2036 
2037 	dev->dv_driver_suspend = NULL;
2038 	dev->dv_driver_resume = NULL;
2039 
2040 	mutex_enter(&dvl->dvl_mtx);
2041 	dev->dv_flags &= ~DVF_POWER_HANDLERS;
2042 	while (dvl->dvl_nlock > 0 || dvl->dvl_nwait > 0) {
2043 		/* Wake a thread that waits for the lock.  That
2044 		 * thread will fail to acquire the lock, and then
2045 		 * it will wake the next thread that waits for the
2046 		 * lock, or else it will wake us.
2047 		 */
2048 		cv_signal(&dvl->dvl_cv);
2049 		pmflock_debug(dev, __func__, __LINE__);
2050 		cv_wait(&dvl->dvl_cv, &dvl->dvl_mtx);
2051 		pmflock_debug(dev, __func__, __LINE__);
2052 	}
2053 	mutex_exit(&dvl->dvl_mtx);
2054 }
2055 
2056 bool
2057 device_pmf_driver_child_register(device_t dev)
2058 {
2059 	device_t parent = device_parent(dev);
2060 
2061 	if (parent == NULL || parent->dv_driver_child_register == NULL)
2062 		return true;
2063 	return (*parent->dv_driver_child_register)(dev);
2064 }
2065 
2066 void
2067 device_pmf_driver_set_child_register(device_t dev,
2068     bool (*child_register)(device_t))
2069 {
2070 	dev->dv_driver_child_register = child_register;
2071 }
2072 
2073 static void
2074 pmflock_debug(device_t dev, const char *func, int line)
2075 {
2076 	device_lock_t dvl = device_getlock(dev);
2077 
2078 	aprint_debug_dev(dev, "%s.%d, %s dvl_nlock %d dvl_nwait %d dv_flags %x\n",
2079 	    func, line, curlwp_name(), dvl->dvl_nlock, dvl->dvl_nwait,
2080 	    dev->dv_flags);
2081 }
2082 
2083 static bool
2084 device_pmf_lock1(device_t dev)
2085 {
2086 	device_lock_t dvl = device_getlock(dev);
2087 
2088 	while (device_pmf_is_registered(dev) &&
2089 	    dvl->dvl_nlock > 0 && dvl->dvl_holder != curlwp) {
2090 		dvl->dvl_nwait++;
2091 		pmflock_debug(dev, __func__, __LINE__);
2092 		cv_wait(&dvl->dvl_cv, &dvl->dvl_mtx);
2093 		pmflock_debug(dev, __func__, __LINE__);
2094 		dvl->dvl_nwait--;
2095 	}
2096 	if (!device_pmf_is_registered(dev)) {
2097 		pmflock_debug(dev, __func__, __LINE__);
2098 		/* We could not acquire the lock, but some other thread may
2099 		 * wait for it, also.  Wake that thread.
2100 		 */
2101 		cv_signal(&dvl->dvl_cv);
2102 		return false;
2103 	}
2104 	dvl->dvl_nlock++;
2105 	dvl->dvl_holder = curlwp;
2106 	pmflock_debug(dev, __func__, __LINE__);
2107 	return true;
2108 }
2109 
2110 bool
2111 device_pmf_lock(device_t dev)
2112 {
2113 	bool rc;
2114 	device_lock_t dvl = device_getlock(dev);
2115 
2116 	mutex_enter(&dvl->dvl_mtx);
2117 	rc = device_pmf_lock1(dev);
2118 	mutex_exit(&dvl->dvl_mtx);
2119 
2120 	return rc;
2121 }
2122 
2123 void
2124 device_pmf_unlock(device_t dev)
2125 {
2126 	device_lock_t dvl = device_getlock(dev);
2127 
2128 	KASSERT(dvl->dvl_nlock > 0);
2129 	mutex_enter(&dvl->dvl_mtx);
2130 	if (--dvl->dvl_nlock == 0)
2131 		dvl->dvl_holder = NULL;
2132 	cv_signal(&dvl->dvl_cv);
2133 	pmflock_debug(dev, __func__, __LINE__);
2134 	mutex_exit(&dvl->dvl_mtx);
2135 }
2136 
2137 device_lock_t
2138 device_getlock(device_t dev)
2139 {
2140 	return &dev->dv_lock;
2141 }
2142 
2143 void *
2144 device_pmf_bus_private(device_t dev)
2145 {
2146 	return dev->dv_bus_private;
2147 }
2148 
2149 bool
2150 device_pmf_bus_suspend(device_t dev PMF_FN_ARGS)
2151 {
2152 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) != 0)
2153 		return true;
2154 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) == 0 ||
2155 	    (dev->dv_flags & DVF_DRIVER_SUSPENDED) == 0)
2156 		return false;
2157 	if (pmf_qual_depth(PMF_FN_CALL1) <= DEVACT_LEVEL_BUS &&
2158 	    dev->dv_bus_suspend != NULL &&
2159 	    !(*dev->dv_bus_suspend)(dev PMF_FN_CALL))
2160 		return false;
2161 
2162 	dev->dv_flags |= DVF_BUS_SUSPENDED;
2163 	return true;
2164 }
2165 
2166 bool
2167 device_pmf_bus_resume(device_t dev PMF_FN_ARGS)
2168 {
2169 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) == 0)
2170 		return true;
2171 	if (pmf_qual_depth(PMF_FN_CALL1) <= DEVACT_LEVEL_BUS &&
2172 	    dev->dv_bus_resume != NULL &&
2173 	    !(*dev->dv_bus_resume)(dev PMF_FN_CALL))
2174 		return false;
2175 
2176 	dev->dv_flags &= ~DVF_BUS_SUSPENDED;
2177 	return true;
2178 }
2179 
2180 bool
2181 device_pmf_bus_shutdown(device_t dev, int how)
2182 {
2183 
2184 	if (*dev->dv_bus_shutdown != NULL &&
2185 	    !(*dev->dv_bus_shutdown)(dev, how))
2186 		return false;
2187 	return true;
2188 }
2189 
2190 void
2191 device_pmf_bus_register(device_t dev, void *priv,
2192     bool (*suspend)(device_t PMF_FN_PROTO),
2193     bool (*resume)(device_t PMF_FN_PROTO),
2194     bool (*shutdown)(device_t, int), void (*deregister)(device_t))
2195 {
2196 	dev->dv_bus_private = priv;
2197 	dev->dv_bus_resume = resume;
2198 	dev->dv_bus_suspend = suspend;
2199 	dev->dv_bus_shutdown = shutdown;
2200 	dev->dv_bus_deregister = deregister;
2201 }
2202 
2203 void
2204 device_pmf_bus_deregister(device_t dev)
2205 {
2206 	if (dev->dv_bus_deregister == NULL)
2207 		return;
2208 	(*dev->dv_bus_deregister)(dev);
2209 	dev->dv_bus_private = NULL;
2210 	dev->dv_bus_suspend = NULL;
2211 	dev->dv_bus_resume = NULL;
2212 	dev->dv_bus_deregister = NULL;
2213 }
2214 
2215 void *
2216 device_pmf_class_private(device_t dev)
2217 {
2218 	return dev->dv_class_private;
2219 }
2220 
2221 bool
2222 device_pmf_class_suspend(device_t dev PMF_FN_ARGS)
2223 {
2224 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) != 0)
2225 		return true;
2226 	if (pmf_qual_depth(PMF_FN_CALL1) <= DEVACT_LEVEL_CLASS &&
2227 	    dev->dv_class_suspend != NULL &&
2228 	    !(*dev->dv_class_suspend)(dev PMF_FN_CALL))
2229 		return false;
2230 
2231 	dev->dv_flags |= DVF_CLASS_SUSPENDED;
2232 	return true;
2233 }
2234 
2235 bool
2236 device_pmf_class_resume(device_t dev PMF_FN_ARGS)
2237 {
2238 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) == 0)
2239 		return true;
2240 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) != 0 ||
2241 	    (dev->dv_flags & DVF_DRIVER_SUSPENDED) != 0)
2242 		return false;
2243 	if (pmf_qual_depth(PMF_FN_CALL1) <= DEVACT_LEVEL_CLASS &&
2244 	    dev->dv_class_resume != NULL &&
2245 	    !(*dev->dv_class_resume)(dev PMF_FN_CALL))
2246 		return false;
2247 
2248 	dev->dv_flags &= ~DVF_CLASS_SUSPENDED;
2249 	return true;
2250 }
2251 
2252 void
2253 device_pmf_class_register(device_t dev, void *priv,
2254     bool (*suspend)(device_t PMF_FN_PROTO),
2255     bool (*resume)(device_t PMF_FN_PROTO),
2256     void (*deregister)(device_t))
2257 {
2258 	dev->dv_class_private = priv;
2259 	dev->dv_class_suspend = suspend;
2260 	dev->dv_class_resume = resume;
2261 	dev->dv_class_deregister = deregister;
2262 }
2263 
2264 void
2265 device_pmf_class_deregister(device_t dev)
2266 {
2267 	if (dev->dv_class_deregister == NULL)
2268 		return;
2269 	(*dev->dv_class_deregister)(dev);
2270 	dev->dv_class_private = NULL;
2271 	dev->dv_class_suspend = NULL;
2272 	dev->dv_class_resume = NULL;
2273 	dev->dv_class_deregister = NULL;
2274 }
2275 
2276 bool
2277 device_active(device_t dev, devactive_t type)
2278 {
2279 	size_t i;
2280 
2281 	if (dev->dv_activity_count == 0)
2282 		return false;
2283 
2284 	for (i = 0; i < dev->dv_activity_count; ++i) {
2285 		if (dev->dv_activity_handlers[i] == NULL)
2286 			break;
2287 		(*dev->dv_activity_handlers[i])(dev, type);
2288 	}
2289 
2290 	return true;
2291 }
2292 
2293 bool
2294 device_active_register(device_t dev, void (*handler)(device_t, devactive_t))
2295 {
2296 	void (**new_handlers)(device_t, devactive_t);
2297 	void (**old_handlers)(device_t, devactive_t);
2298 	size_t i, old_size, new_size;
2299 	int s;
2300 
2301 	old_handlers = dev->dv_activity_handlers;
2302 	old_size = dev->dv_activity_count;
2303 
2304 	for (i = 0; i < old_size; ++i) {
2305 		KASSERT(old_handlers[i] != handler);
2306 		if (old_handlers[i] == NULL) {
2307 			old_handlers[i] = handler;
2308 			return true;
2309 		}
2310 	}
2311 
2312 	new_size = old_size + 4;
2313 	new_handlers = kmem_alloc(sizeof(void *[new_size]), KM_SLEEP);
2314 
2315 	memcpy(new_handlers, old_handlers, sizeof(void *[old_size]));
2316 	new_handlers[old_size] = handler;
2317 	memset(new_handlers + old_size + 1, 0,
2318 	    sizeof(int [new_size - (old_size+1)]));
2319 
2320 	s = splhigh();
2321 	dev->dv_activity_count = new_size;
2322 	dev->dv_activity_handlers = new_handlers;
2323 	splx(s);
2324 
2325 	if (old_handlers != NULL)
2326 		kmem_free(old_handlers, sizeof(void * [old_size]));
2327 
2328 	return true;
2329 }
2330 
2331 void
2332 device_active_deregister(device_t dev, void (*handler)(device_t, devactive_t))
2333 {
2334 	void (**old_handlers)(device_t, devactive_t);
2335 	size_t i, old_size;
2336 	int s;
2337 
2338 	old_handlers = dev->dv_activity_handlers;
2339 	old_size = dev->dv_activity_count;
2340 
2341 	for (i = 0; i < old_size; ++i) {
2342 		if (old_handlers[i] == handler)
2343 			break;
2344 		if (old_handlers[i] == NULL)
2345 			return; /* XXX panic? */
2346 	}
2347 
2348 	if (i == old_size)
2349 		return; /* XXX panic? */
2350 
2351 	for (; i < old_size - 1; ++i) {
2352 		if ((old_handlers[i] = old_handlers[i + 1]) != NULL)
2353 			continue;
2354 
2355 		if (i == 0) {
2356 			s = splhigh();
2357 			dev->dv_activity_count = 0;
2358 			dev->dv_activity_handlers = NULL;
2359 			splx(s);
2360 			kmem_free(old_handlers, sizeof(void *[old_size]));
2361 		}
2362 		return;
2363 	}
2364 	old_handlers[i] = NULL;
2365 }
2366 
2367 /*
2368  * Device Iteration
2369  *
2370  * deviter_t: a device iterator.  Holds state for a "walk" visiting
2371  *     each device_t's in the device tree.
2372  *
2373  * deviter_init(di, flags): initialize the device iterator `di'
2374  *     to "walk" the device tree.  deviter_next(di) will return
2375  *     the first device_t in the device tree, or NULL if there are
2376  *     no devices.
2377  *
2378  *     `flags' is one or more of DEVITER_F_RW, indicating that the
2379  *     caller intends to modify the device tree by calling
2380  *     config_detach(9) on devices in the order that the iterator
2381  *     returns them; DEVITER_F_ROOT_FIRST, asking for the devices
2382  *     nearest the "root" of the device tree to be returned, first;
2383  *     DEVITER_F_LEAVES_FIRST, asking for the devices furthest from
2384  *     the root of the device tree, first; and DEVITER_F_SHUTDOWN,
2385  *     indicating both that deviter_init() should not respect any
2386  *     locks on the device tree, and that deviter_next(di) may run
2387  *     in more than one LWP before the walk has finished.
2388  *
2389  *     Only one DEVITER_F_RW iterator may be in the device tree at
2390  *     once.
2391  *
2392  *     DEVITER_F_SHUTDOWN implies DEVITER_F_RW.
2393  *
2394  *     Results are undefined if the flags DEVITER_F_ROOT_FIRST and
2395  *     DEVITER_F_LEAVES_FIRST are used in combination.
2396  *
2397  * deviter_first(di, flags): initialize the device iterator `di'
2398  *     and return the first device_t in the device tree, or NULL
2399  *     if there are no devices.  The statement
2400  *
2401  *         dv = deviter_first(di);
2402  *
2403  *     is shorthand for
2404  *
2405  *         deviter_init(di);
2406  *         dv = deviter_next(di);
2407  *
2408  * deviter_next(di): return the next device_t in the device tree,
2409  *     or NULL if there are no more devices.  deviter_next(di)
2410  *     is undefined if `di' was not initialized with deviter_init() or
2411  *     deviter_first().
2412  *
2413  * deviter_release(di): stops iteration (subsequent calls to
2414  *     deviter_next() will return NULL), releases any locks and
2415  *     resources held by the device iterator.
2416  *
2417  * Device iteration does not return device_t's in any particular
2418  * order.  An iterator will never return the same device_t twice.
2419  * Device iteration is guaranteed to complete---i.e., if deviter_next(di)
2420  * is called repeatedly on the same `di', it will eventually return
2421  * NULL.  It is ok to attach/detach devices during device iteration.
2422  */
2423 void
2424 deviter_init(deviter_t *di, deviter_flags_t flags)
2425 {
2426 	device_t dv;
2427 	bool rw;
2428 
2429 	mutex_enter(&alldevs_mtx);
2430 	if ((flags & DEVITER_F_SHUTDOWN) != 0) {
2431 		flags |= DEVITER_F_RW;
2432 		alldevs_nwrite++;
2433 		alldevs_writer = NULL;
2434 		alldevs_nread = 0;
2435 	} else {
2436 		rw = (flags & DEVITER_F_RW) != 0;
2437 
2438 		if (alldevs_nwrite > 0 && alldevs_writer == NULL)
2439 			;
2440 		else while ((alldevs_nwrite != 0 && alldevs_writer != curlwp) ||
2441 		       (rw && alldevs_nread != 0))
2442 			cv_wait(&alldevs_cv, &alldevs_mtx);
2443 
2444 		if (rw) {
2445 			if (alldevs_nwrite++ == 0)
2446 				alldevs_writer = curlwp;
2447 		} else
2448 			alldevs_nread++;
2449 	}
2450 	mutex_exit(&alldevs_mtx);
2451 
2452 	memset(di, 0, sizeof(*di));
2453 
2454 	di->di_flags = flags;
2455 
2456 	switch (di->di_flags & (DEVITER_F_LEAVES_FIRST|DEVITER_F_ROOT_FIRST)) {
2457 	case DEVITER_F_LEAVES_FIRST:
2458 		TAILQ_FOREACH(dv, &alldevs, dv_list)
2459 			di->di_curdepth = MAX(di->di_curdepth, dv->dv_depth);
2460 		break;
2461 	case DEVITER_F_ROOT_FIRST:
2462 		TAILQ_FOREACH(dv, &alldevs, dv_list)
2463 			di->di_maxdepth = MAX(di->di_maxdepth, dv->dv_depth);
2464 		break;
2465 	default:
2466 		break;
2467 	}
2468 
2469 	deviter_reinit(di);
2470 }
2471 
2472 static void
2473 deviter_reinit(deviter_t *di)
2474 {
2475 	if ((di->di_flags & DEVITER_F_RW) != 0)
2476 		di->di_prev = TAILQ_LAST(&alldevs, devicelist);
2477 	else
2478 		di->di_prev = TAILQ_FIRST(&alldevs);
2479 }
2480 
2481 device_t
2482 deviter_first(deviter_t *di, deviter_flags_t flags)
2483 {
2484 	deviter_init(di, flags);
2485 	return deviter_next(di);
2486 }
2487 
2488 static device_t
2489 deviter_next1(deviter_t *di)
2490 {
2491 	device_t dv;
2492 
2493 	dv = di->di_prev;
2494 
2495 	if (dv == NULL)
2496 		;
2497 	else if ((di->di_flags & DEVITER_F_RW) != 0)
2498 		di->di_prev = TAILQ_PREV(dv, devicelist, dv_list);
2499 	else
2500 		di->di_prev = TAILQ_NEXT(dv, dv_list);
2501 
2502 	return dv;
2503 }
2504 
2505 device_t
2506 deviter_next(deviter_t *di)
2507 {
2508 	device_t dv = NULL;
2509 
2510 	switch (di->di_flags & (DEVITER_F_LEAVES_FIRST|DEVITER_F_ROOT_FIRST)) {
2511 	case 0:
2512 		return deviter_next1(di);
2513 	case DEVITER_F_LEAVES_FIRST:
2514 		while (di->di_curdepth >= 0) {
2515 			if ((dv = deviter_next1(di)) == NULL) {
2516 				di->di_curdepth--;
2517 				deviter_reinit(di);
2518 			} else if (dv->dv_depth == di->di_curdepth)
2519 				break;
2520 		}
2521 		return dv;
2522 	case DEVITER_F_ROOT_FIRST:
2523 		while (di->di_curdepth <= di->di_maxdepth) {
2524 			if ((dv = deviter_next1(di)) == NULL) {
2525 				di->di_curdepth++;
2526 				deviter_reinit(di);
2527 			} else if (dv->dv_depth == di->di_curdepth)
2528 				break;
2529 		}
2530 		return dv;
2531 	default:
2532 		return NULL;
2533 	}
2534 }
2535 
2536 void
2537 deviter_release(deviter_t *di)
2538 {
2539 	bool rw = (di->di_flags & DEVITER_F_RW) != 0;
2540 
2541 	mutex_enter(&alldevs_mtx);
2542 	if (!rw) {
2543 		--alldevs_nread;
2544 		cv_signal(&alldevs_cv);
2545 	} else if (alldevs_nwrite > 0 && alldevs_writer == NULL) {
2546 		--alldevs_nwrite;	/* shutting down: do not signal */
2547 	} else {
2548 		KASSERT(alldevs_nwrite != 0);
2549 		if (--alldevs_nwrite == 0)
2550 			alldevs_writer = NULL;
2551 		cv_signal(&alldevs_cv);
2552 	}
2553 	mutex_exit(&alldevs_mtx);
2554 }
2555 
2556 static void
2557 sysctl_detach_setup(struct sysctllog **clog)
2558 {
2559 	const struct sysctlnode *node = NULL;
2560 
2561 	sysctl_createv(clog, 0, NULL, &node,
2562 		CTLFLAG_PERMANENT,
2563 		CTLTYPE_NODE, "kern", NULL,
2564 		NULL, 0, NULL, 0,
2565 		CTL_KERN, CTL_EOL);
2566 
2567 	if (node == NULL)
2568 		return;
2569 
2570 	sysctl_createv(clog, 0, &node, NULL,
2571 		CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
2572 		CTLTYPE_INT, "detachall",
2573 		SYSCTL_DESCR("Detach all devices at shutdown"),
2574 		NULL, 0, &detachall, 0,
2575 		CTL_CREATE, CTL_EOL);
2576 }
2577