xref: /netbsd-src/sys/kern/subr_autoconf.c (revision 6dffe8d42bd46273f674d7ab834e7be9b1af990e)
1 /* $NetBSD: subr_autoconf.c,v 1.179 2009/07/14 13:24:00 tsutsui 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 1.179 2009/07/14 13:24:00 tsutsui Exp $");
81 
82 #include "opt_ddb.h"
83 #include "drvctl.h"
84 
85 #include <sys/param.h>
86 #include <sys/device.h>
87 #include <sys/disklabel.h>
88 #include <sys/conf.h>
89 #include <sys/kauth.h>
90 #include <sys/malloc.h>
91 #include <sys/kmem.h>
92 #include <sys/systm.h>
93 #include <sys/kernel.h>
94 #include <sys/errno.h>
95 #include <sys/proc.h>
96 #include <sys/reboot.h>
97 #include <sys/kthread.h>
98 #include <sys/buf.h>
99 #include <sys/dirent.h>
100 #include <sys/vnode.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 <machine/limits.h>
114 
115 #include "opt_userconf.h"
116 #ifdef USERCONF
117 #include <sys/userconf.h>
118 #endif
119 
120 #ifdef __i386__
121 #include "opt_splash.h"
122 #if defined(SPLASHSCREEN) && defined(SPLASHSCREEN_PROGRESS)
123 #include <dev/splash/splash.h>
124 extern struct splash_progress *splash_progress_state;
125 #endif
126 #endif
127 
128 /*
129  * Autoconfiguration subroutines.
130  */
131 
132 /*
133  * ioconf.c exports exactly two names: cfdata and cfroots.  All system
134  * devices and drivers are found via these tables.
135  */
136 extern struct cfdata cfdata[];
137 extern const short cfroots[];
138 
139 /*
140  * List of all cfdriver structures.  We use this to detect duplicates
141  * when other cfdrivers are loaded.
142  */
143 struct cfdriverlist allcfdrivers = LIST_HEAD_INITIALIZER(&allcfdrivers);
144 extern struct cfdriver * const cfdriver_list_initial[];
145 
146 /*
147  * Initial list of cfattach's.
148  */
149 extern const struct cfattachinit cfattachinit[];
150 
151 /*
152  * List of cfdata tables.  We always have one such list -- the one
153  * built statically when the kernel was configured.
154  */
155 struct cftablelist allcftables = TAILQ_HEAD_INITIALIZER(allcftables);
156 static struct cftable initcftable;
157 
158 #define	ROOT ((device_t)NULL)
159 
160 struct matchinfo {
161 	cfsubmatch_t fn;
162 	struct	device *parent;
163 	const int *locs;
164 	void	*aux;
165 	struct	cfdata *match;
166 	int	pri;
167 };
168 
169 static char *number(char *, int);
170 static void mapply(struct matchinfo *, cfdata_t);
171 static device_t config_devalloc(const device_t, const cfdata_t, const int *);
172 static void config_devdealloc(device_t);
173 static void config_makeroom(int, struct cfdriver *);
174 static void config_devlink(device_t);
175 static void config_devunlink(device_t);
176 static void config_twiddle_fn(void *);
177 
178 static void pmflock_debug(device_t, const char *, int);
179 static void pmflock_debug_with_flags(device_t, const char *, int PMF_FN_PROTO);
180 
181 static device_t deviter_next1(deviter_t *);
182 static void deviter_reinit(deviter_t *);
183 
184 struct deferred_config {
185 	TAILQ_ENTRY(deferred_config) dc_queue;
186 	device_t dc_dev;
187 	void (*dc_func)(device_t);
188 };
189 
190 TAILQ_HEAD(deferred_config_head, deferred_config);
191 
192 struct deferred_config_head deferred_config_queue =
193 	TAILQ_HEAD_INITIALIZER(deferred_config_queue);
194 struct deferred_config_head interrupt_config_queue =
195 	TAILQ_HEAD_INITIALIZER(interrupt_config_queue);
196 int interrupt_config_threads = 8;
197 
198 static void config_process_deferred(struct deferred_config_head *, device_t);
199 
200 /* Hooks to finalize configuration once all real devices have been found. */
201 struct finalize_hook {
202 	TAILQ_ENTRY(finalize_hook) f_list;
203 	int (*f_func)(device_t);
204 	device_t f_dev;
205 };
206 static TAILQ_HEAD(, finalize_hook) config_finalize_list =
207 	TAILQ_HEAD_INITIALIZER(config_finalize_list);
208 static int config_finalize_done;
209 
210 /* list of all devices */
211 struct devicelist alldevs = TAILQ_HEAD_INITIALIZER(alldevs);
212 kcondvar_t alldevs_cv;
213 kmutex_t alldevs_mtx;
214 static int alldevs_nread = 0;
215 static int alldevs_nwrite = 0;
216 static lwp_t *alldevs_writer = NULL;
217 
218 static int config_pending;		/* semaphore for mountroot */
219 static kmutex_t config_misc_lock;
220 static kcondvar_t config_misc_cv;
221 
222 static int detachall = 0;
223 
224 #define	STREQ(s1, s2)			\
225 	(*(s1) == *(s2) && strcmp((s1), (s2)) == 0)
226 
227 static int config_initialized;		/* config_init() has been called. */
228 
229 static int config_do_twiddle;
230 static callout_t config_twiddle_ch;
231 
232 struct vnode *
233 opendisk(struct device *dv)
234 {
235 	int bmajor, bminor;
236 	struct vnode *tmpvn;
237 	int error;
238 	dev_t dev;
239 
240 	/*
241 	 * Lookup major number for disk block device.
242 	 */
243 	bmajor = devsw_name2blk(device_xname(dv), NULL, 0);
244 	if (bmajor == -1)
245 		return NULL;
246 
247 	bminor = minor(device_unit(dv));
248 	/*
249 	 * Fake a temporary vnode for the disk, open it, and read
250 	 * and hash the sectors.
251 	 */
252 	dev = device_is_a(dv, "dk") ? makedev(bmajor, bminor) :
253 	    MAKEDISKDEV(bmajor, bminor, RAW_PART);
254 	if (bdevvp(dev, &tmpvn))
255 		panic("%s: can't alloc vnode for %s", __func__,
256 		    device_xname(dv));
257 	error = VOP_OPEN(tmpvn, FREAD, NOCRED);
258 	if (error) {
259 #ifndef DEBUG
260 		/*
261 		 * Ignore errors caused by missing device, partition,
262 		 * or medium.
263 		 */
264 		if (error != ENXIO && error != ENODEV)
265 #endif
266 			printf("%s: can't open dev %s (%d)\n",
267 			    __func__, device_xname(dv), error);
268 		vput(tmpvn);
269 		return NULL;
270 	}
271 
272 	return tmpvn;
273 }
274 
275 int
276 config_handle_wedges(struct device *dv, int par)
277 {
278 	struct dkwedge_list wl;
279 	struct dkwedge_info *wi;
280 	struct vnode *vn;
281 	char diskname[16];
282 	int i, error;
283 
284 	if ((vn = opendisk(dv)) == NULL)
285 		return -1;
286 
287 	wl.dkwl_bufsize = sizeof(*wi) * 16;
288 	wl.dkwl_buf = wi = malloc(wl.dkwl_bufsize, M_TEMP, M_WAITOK);
289 
290 	error = VOP_IOCTL(vn, DIOCLWEDGES, &wl, FREAD, NOCRED);
291 	VOP_CLOSE(vn, FREAD, NOCRED);
292 	vput(vn);
293 	if (error) {
294 #ifdef DEBUG_WEDGE
295 		printf("%s: List wedges returned %d\n",
296 		    device_xname(dv), error);
297 #endif
298 		free(wi, M_TEMP);
299 		return -1;
300 	}
301 
302 #ifdef DEBUG_WEDGE
303 	printf("%s: Returned %u(%u) wedges\n", device_xname(dv),
304 	    wl.dkwl_nwedges, wl.dkwl_ncopied);
305 #endif
306 	snprintf(diskname, sizeof(diskname), "%s%c", device_xname(dv),
307 	    par + 'a');
308 
309 	for (i = 0; i < wl.dkwl_ncopied; i++) {
310 #ifdef DEBUG_WEDGE
311 		printf("%s: Looking for %s in %s\n",
312 		    device_xname(dv), diskname, wi[i].dkw_wname);
313 #endif
314 		if (strcmp(wi[i].dkw_wname, diskname) == 0)
315 			break;
316 	}
317 
318 	if (i == wl.dkwl_ncopied) {
319 #ifdef DEBUG_WEDGE
320 		printf("%s: Cannot find wedge with parent %s\n",
321 		    device_xname(dv), diskname);
322 #endif
323 		free(wi, M_TEMP);
324 		return -1;
325 	}
326 
327 #ifdef DEBUG_WEDGE
328 	printf("%s: Setting boot wedge %s (%s) at %llu %llu\n",
329 		device_xname(dv), wi[i].dkw_devname, wi[i].dkw_wname,
330 		(unsigned long long)wi[i].dkw_offset,
331 		(unsigned long long)wi[i].dkw_size);
332 #endif
333 	dkwedge_set_bootwedge(dv, wi[i].dkw_offset, wi[i].dkw_size);
334 	free(wi, M_TEMP);
335 	return 0;
336 }
337 
338 /*
339  * Initialize the autoconfiguration data structures.  Normally this
340  * is done by configure(), but some platforms need to do this very
341  * early (to e.g. initialize the console).
342  */
343 void
344 config_init(void)
345 {
346 	const struct cfattachinit *cfai;
347 	int i, j;
348 
349 	if (config_initialized)
350 		return;
351 
352 	mutex_init(&alldevs_mtx, MUTEX_DEFAULT, IPL_NONE);
353 	cv_init(&alldevs_cv, "alldevs");
354 
355 	mutex_init(&config_misc_lock, MUTEX_DEFAULT, IPL_NONE);
356 	cv_init(&config_misc_cv, "cfgmisc");
357 
358 	callout_init(&config_twiddle_ch, CALLOUT_MPSAFE);
359 
360 	/* allcfdrivers is statically initialized. */
361 	for (i = 0; cfdriver_list_initial[i] != NULL; i++) {
362 		if (config_cfdriver_attach(cfdriver_list_initial[i]) != 0)
363 			panic("configure: duplicate `%s' drivers",
364 			    cfdriver_list_initial[i]->cd_name);
365 	}
366 
367 	for (cfai = &cfattachinit[0]; cfai->cfai_name != NULL; cfai++) {
368 		for (j = 0; cfai->cfai_list[j] != NULL; j++) {
369 			if (config_cfattach_attach(cfai->cfai_name,
370 						   cfai->cfai_list[j]) != 0)
371 				panic("configure: duplicate `%s' attachment "
372 				    "of `%s' driver",
373 				    cfai->cfai_list[j]->ca_name,
374 				    cfai->cfai_name);
375 		}
376 	}
377 
378 	initcftable.ct_cfdata = cfdata;
379 	TAILQ_INSERT_TAIL(&allcftables, &initcftable, ct_list);
380 
381 	config_initialized = 1;
382 }
383 
384 void
385 config_deferred(device_t dev)
386 {
387 	config_process_deferred(&deferred_config_queue, dev);
388 	config_process_deferred(&interrupt_config_queue, dev);
389 }
390 
391 static void
392 config_interrupts_thread(void *cookie)
393 {
394 	struct deferred_config *dc;
395 
396 	while ((dc = TAILQ_FIRST(&interrupt_config_queue)) != NULL) {
397 		TAILQ_REMOVE(&interrupt_config_queue, dc, dc_queue);
398 		(*dc->dc_func)(dc->dc_dev);
399 		kmem_free(dc, sizeof(*dc));
400 		config_pending_decr();
401 	}
402 	kthread_exit(0);
403 }
404 
405 /*
406  * Configure the system's hardware.
407  */
408 void
409 configure(void)
410 {
411 	/* Initialize data structures. */
412 	config_init();
413 	/*
414 	 * XXX
415 	 * callout_setfunc() requires mutex(9) so it can't be in config_init()
416 	 * on amiga and atari which use config_init() and autoconf(9) fucntions
417 	 * to initialize console devices.
418 	 */
419 	callout_setfunc(&config_twiddle_ch, config_twiddle_fn, NULL);
420 
421 	pmf_init();
422 #if NDRVCTL > 0
423 	drvctl_init();
424 #endif
425 
426 #ifdef USERCONF
427 	if (boothowto & RB_USERCONF)
428 		user_config();
429 #endif
430 
431 	if ((boothowto & (AB_SILENT|AB_VERBOSE)) == AB_SILENT) {
432 		config_do_twiddle = 1;
433 		printf_nolog("Detecting hardware...");
434 	}
435 
436 	/*
437 	 * Do the machine-dependent portion of autoconfiguration.  This
438 	 * sets the configuration machinery here in motion by "finding"
439 	 * the root bus.  When this function returns, we expect interrupts
440 	 * to be enabled.
441 	 */
442 	cpu_configure();
443 }
444 
445 void
446 configure2(void)
447 {
448 	CPU_INFO_ITERATOR cii;
449 	struct cpu_info *ci;
450 	int i, s;
451 
452 	/*
453 	 * Now that we've found all the hardware, start the real time
454 	 * and statistics clocks.
455 	 */
456 	initclocks();
457 
458 	cold = 0;	/* clocks are running, we're warm now! */
459 	s = splsched();
460 	curcpu()->ci_schedstate.spc_flags |= SPCF_RUNNING;
461 	splx(s);
462 
463 	/* Boot the secondary processors. */
464 	for (CPU_INFO_FOREACH(cii, ci)) {
465 		uvm_cpu_attach(ci);
466 	}
467 	mp_online = true;
468 #if defined(MULTIPROCESSOR)
469 	cpu_boot_secondary_processors();
470 #endif
471 
472 	/* Setup the runqueues and scheduler. */
473 	runq_init();
474 	sched_init();
475 
476 	/*
477 	 * Bus scans can make it appear as if the system has paused, so
478 	 * twiddle constantly while config_interrupts() jobs are running.
479 	 */
480 	config_twiddle_fn(NULL);
481 
482 	/*
483 	 * Create threads to call back and finish configuration for
484 	 * devices that want interrupts enabled.
485 	 */
486 	for (i = 0; i < interrupt_config_threads; i++) {
487 		(void)kthread_create(PRI_NONE, 0, NULL,
488 		    config_interrupts_thread, NULL, NULL, "config");
489 	}
490 
491 	/* Get the threads going and into any sleeps before continuing. */
492 	yield();
493 }
494 
495 /*
496  * Announce device attach/detach to userland listeners.
497  */
498 static void
499 devmon_report_device(device_t dev, bool isattach)
500 {
501 #if NDRVCTL > 0
502 	prop_dictionary_t ev;
503 	const char *parent;
504 	const char *what;
505 	device_t pdev = device_parent(dev);
506 
507 	ev = prop_dictionary_create();
508 	if (ev == NULL)
509 		return;
510 
511 	what = (isattach ? "device-attach" : "device-detach");
512 	parent = (pdev == NULL ? "root" : device_xname(pdev));
513 	if (!prop_dictionary_set_cstring(ev, "device", device_xname(dev)) ||
514 	    !prop_dictionary_set_cstring(ev, "parent", parent)) {
515 		prop_object_release(ev);
516 		return;
517 	}
518 
519 	devmon_insert(what, ev);
520 #endif
521 }
522 
523 /*
524  * Add a cfdriver to the system.
525  */
526 int
527 config_cfdriver_attach(struct cfdriver *cd)
528 {
529 	struct cfdriver *lcd;
530 
531 	/* Make sure this driver isn't already in the system. */
532 	LIST_FOREACH(lcd, &allcfdrivers, cd_list) {
533 		if (STREQ(lcd->cd_name, cd->cd_name))
534 			return EEXIST;
535 	}
536 
537 	LIST_INIT(&cd->cd_attach);
538 	LIST_INSERT_HEAD(&allcfdrivers, cd, cd_list);
539 
540 	return 0;
541 }
542 
543 /*
544  * Remove a cfdriver from the system.
545  */
546 int
547 config_cfdriver_detach(struct cfdriver *cd)
548 {
549 	int i;
550 
551 	/* Make sure there are no active instances. */
552 	for (i = 0; i < cd->cd_ndevs; i++) {
553 		if (cd->cd_devs[i] != NULL)
554 			return EBUSY;
555 	}
556 
557 	/* ...and no attachments loaded. */
558 	if (LIST_EMPTY(&cd->cd_attach) == 0)
559 		return EBUSY;
560 
561 	LIST_REMOVE(cd, cd_list);
562 
563 	KASSERT(cd->cd_devs == NULL);
564 
565 	return 0;
566 }
567 
568 /*
569  * Look up a cfdriver by name.
570  */
571 struct cfdriver *
572 config_cfdriver_lookup(const char *name)
573 {
574 	struct cfdriver *cd;
575 
576 	LIST_FOREACH(cd, &allcfdrivers, cd_list) {
577 		if (STREQ(cd->cd_name, name))
578 			return cd;
579 	}
580 
581 	return NULL;
582 }
583 
584 /*
585  * Add a cfattach to the specified driver.
586  */
587 int
588 config_cfattach_attach(const char *driver, struct cfattach *ca)
589 {
590 	struct cfattach *lca;
591 	struct cfdriver *cd;
592 
593 	cd = config_cfdriver_lookup(driver);
594 	if (cd == NULL)
595 		return ESRCH;
596 
597 	/* Make sure this attachment isn't already on this driver. */
598 	LIST_FOREACH(lca, &cd->cd_attach, ca_list) {
599 		if (STREQ(lca->ca_name, ca->ca_name))
600 			return EEXIST;
601 	}
602 
603 	LIST_INSERT_HEAD(&cd->cd_attach, ca, ca_list);
604 
605 	return 0;
606 }
607 
608 /*
609  * Remove a cfattach from the specified driver.
610  */
611 int
612 config_cfattach_detach(const char *driver, struct cfattach *ca)
613 {
614 	struct cfdriver *cd;
615 	device_t dev;
616 	int i;
617 
618 	cd = config_cfdriver_lookup(driver);
619 	if (cd == NULL)
620 		return ESRCH;
621 
622 	/* Make sure there are no active instances. */
623 	for (i = 0; i < cd->cd_ndevs; i++) {
624 		if ((dev = cd->cd_devs[i]) == NULL)
625 			continue;
626 		if (dev->dv_cfattach == ca)
627 			return EBUSY;
628 	}
629 
630 	LIST_REMOVE(ca, ca_list);
631 
632 	return 0;
633 }
634 
635 /*
636  * Look up a cfattach by name.
637  */
638 static struct cfattach *
639 config_cfattach_lookup_cd(struct cfdriver *cd, const char *atname)
640 {
641 	struct cfattach *ca;
642 
643 	LIST_FOREACH(ca, &cd->cd_attach, ca_list) {
644 		if (STREQ(ca->ca_name, atname))
645 			return ca;
646 	}
647 
648 	return NULL;
649 }
650 
651 /*
652  * Look up a cfattach by driver/attachment name.
653  */
654 struct cfattach *
655 config_cfattach_lookup(const char *name, const char *atname)
656 {
657 	struct cfdriver *cd;
658 
659 	cd = config_cfdriver_lookup(name);
660 	if (cd == NULL)
661 		return NULL;
662 
663 	return config_cfattach_lookup_cd(cd, atname);
664 }
665 
666 /*
667  * Apply the matching function and choose the best.  This is used
668  * a few times and we want to keep the code small.
669  */
670 static void
671 mapply(struct matchinfo *m, cfdata_t cf)
672 {
673 	int pri;
674 
675 	if (m->fn != NULL) {
676 		pri = (*m->fn)(m->parent, cf, m->locs, m->aux);
677 	} else {
678 		pri = config_match(m->parent, cf, m->aux);
679 	}
680 	if (pri > m->pri) {
681 		m->match = cf;
682 		m->pri = pri;
683 	}
684 }
685 
686 int
687 config_stdsubmatch(device_t parent, cfdata_t cf, const int *locs, void *aux)
688 {
689 	const struct cfiattrdata *ci;
690 	const struct cflocdesc *cl;
691 	int nlocs, i;
692 
693 	ci = cfiattr_lookup(cf->cf_pspec->cfp_iattr, parent->dv_cfdriver);
694 	KASSERT(ci);
695 	nlocs = ci->ci_loclen;
696 	KASSERT(!nlocs || locs);
697 	for (i = 0; i < nlocs; i++) {
698 		cl = &ci->ci_locdesc[i];
699 		/* !cld_defaultstr means no default value */
700 		if ((!(cl->cld_defaultstr)
701 		     || (cf->cf_loc[i] != cl->cld_default))
702 		    && cf->cf_loc[i] != locs[i])
703 			return 0;
704 	}
705 
706 	return config_match(parent, cf, aux);
707 }
708 
709 /*
710  * Helper function: check whether the driver supports the interface attribute
711  * and return its descriptor structure.
712  */
713 static const struct cfiattrdata *
714 cfdriver_get_iattr(const struct cfdriver *cd, const char *ia)
715 {
716 	const struct cfiattrdata * const *cpp;
717 
718 	if (cd->cd_attrs == NULL)
719 		return 0;
720 
721 	for (cpp = cd->cd_attrs; *cpp; cpp++) {
722 		if (STREQ((*cpp)->ci_name, ia)) {
723 			/* Match. */
724 			return *cpp;
725 		}
726 	}
727 	return 0;
728 }
729 
730 /*
731  * Lookup an interface attribute description by name.
732  * If the driver is given, consider only its supported attributes.
733  */
734 const struct cfiattrdata *
735 cfiattr_lookup(const char *name, const struct cfdriver *cd)
736 {
737 	const struct cfdriver *d;
738 	const struct cfiattrdata *ia;
739 
740 	if (cd)
741 		return cfdriver_get_iattr(cd, name);
742 
743 	LIST_FOREACH(d, &allcfdrivers, cd_list) {
744 		ia = cfdriver_get_iattr(d, name);
745 		if (ia)
746 			return ia;
747 	}
748 	return 0;
749 }
750 
751 /*
752  * Determine if `parent' is a potential parent for a device spec based
753  * on `cfp'.
754  */
755 static int
756 cfparent_match(const device_t parent, const struct cfparent *cfp)
757 {
758 	struct cfdriver *pcd;
759 
760 	/* We don't match root nodes here. */
761 	if (cfp == NULL)
762 		return 0;
763 
764 	pcd = parent->dv_cfdriver;
765 	KASSERT(pcd != NULL);
766 
767 	/*
768 	 * First, ensure this parent has the correct interface
769 	 * attribute.
770 	 */
771 	if (!cfdriver_get_iattr(pcd, cfp->cfp_iattr))
772 		return 0;
773 
774 	/*
775 	 * If no specific parent device instance was specified (i.e.
776 	 * we're attaching to the attribute only), we're done!
777 	 */
778 	if (cfp->cfp_parent == NULL)
779 		return 1;
780 
781 	/*
782 	 * Check the parent device's name.
783 	 */
784 	if (STREQ(pcd->cd_name, cfp->cfp_parent) == 0)
785 		return 0;	/* not the same parent */
786 
787 	/*
788 	 * Make sure the unit number matches.
789 	 */
790 	if (cfp->cfp_unit == DVUNIT_ANY ||	/* wildcard */
791 	    cfp->cfp_unit == parent->dv_unit)
792 		return 1;
793 
794 	/* Unit numbers don't match. */
795 	return 0;
796 }
797 
798 /*
799  * Helper for config_cfdata_attach(): check all devices whether it could be
800  * parent any attachment in the config data table passed, and rescan.
801  */
802 static void
803 rescan_with_cfdata(const struct cfdata *cf)
804 {
805 	device_t d;
806 	const struct cfdata *cf1;
807 	deviter_t di;
808 
809 
810 	/*
811 	 * "alldevs" is likely longer than a modules's cfdata, so make it
812 	 * the outer loop.
813 	 */
814 	for (d = deviter_first(&di, 0); d != NULL; d = deviter_next(&di)) {
815 
816 		if (!(d->dv_cfattach->ca_rescan))
817 			continue;
818 
819 		for (cf1 = cf; cf1->cf_name; cf1++) {
820 
821 			if (!cfparent_match(d, cf1->cf_pspec))
822 				continue;
823 
824 			(*d->dv_cfattach->ca_rescan)(d,
825 				cf1->cf_pspec->cfp_iattr, cf1->cf_loc);
826 		}
827 	}
828 	deviter_release(&di);
829 }
830 
831 /*
832  * Attach a supplemental config data table and rescan potential
833  * parent devices if required.
834  */
835 int
836 config_cfdata_attach(cfdata_t cf, int scannow)
837 {
838 	struct cftable *ct;
839 
840 	ct = kmem_alloc(sizeof(*ct), KM_SLEEP);
841 	ct->ct_cfdata = cf;
842 	TAILQ_INSERT_TAIL(&allcftables, ct, ct_list);
843 
844 	if (scannow)
845 		rescan_with_cfdata(cf);
846 
847 	return 0;
848 }
849 
850 /*
851  * Helper for config_cfdata_detach: check whether a device is
852  * found through any attachment in the config data table.
853  */
854 static int
855 dev_in_cfdata(const struct device *d, const struct cfdata *cf)
856 {
857 	const struct cfdata *cf1;
858 
859 	for (cf1 = cf; cf1->cf_name; cf1++)
860 		if (d->dv_cfdata == cf1)
861 			return 1;
862 
863 	return 0;
864 }
865 
866 /*
867  * Detach a supplemental config data table. Detach all devices found
868  * through that table (and thus keeping references to it) before.
869  */
870 int
871 config_cfdata_detach(cfdata_t cf)
872 {
873 	device_t d;
874 	int error = 0;
875 	struct cftable *ct;
876 	deviter_t di;
877 
878 	for (d = deviter_first(&di, DEVITER_F_RW); d != NULL;
879 	     d = deviter_next(&di)) {
880 		if (!dev_in_cfdata(d, cf))
881 			continue;
882 		if ((error = config_detach(d, 0)) != 0)
883 			break;
884 	}
885 	deviter_release(&di);
886 	if (error) {
887 		aprint_error_dev(d, "unable to detach instance\n");
888 		return error;
889 	}
890 
891 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
892 		if (ct->ct_cfdata == cf) {
893 			TAILQ_REMOVE(&allcftables, ct, ct_list);
894 			kmem_free(ct, sizeof(*ct));
895 			return 0;
896 		}
897 	}
898 
899 	/* not found -- shouldn't happen */
900 	return EINVAL;
901 }
902 
903 /*
904  * Invoke the "match" routine for a cfdata entry on behalf of
905  * an external caller, usually a "submatch" routine.
906  */
907 int
908 config_match(device_t parent, cfdata_t cf, void *aux)
909 {
910 	struct cfattach *ca;
911 
912 	ca = config_cfattach_lookup(cf->cf_name, cf->cf_atname);
913 	if (ca == NULL) {
914 		/* No attachment for this entry, oh well. */
915 		return 0;
916 	}
917 
918 	return (*ca->ca_match)(parent, cf, aux);
919 }
920 
921 /*
922  * Iterate over all potential children of some device, calling the given
923  * function (default being the child's match function) for each one.
924  * Nonzero returns are matches; the highest value returned is considered
925  * the best match.  Return the `found child' if we got a match, or NULL
926  * otherwise.  The `aux' pointer is simply passed on through.
927  *
928  * Note that this function is designed so that it can be used to apply
929  * an arbitrary function to all potential children (its return value
930  * can be ignored).
931  */
932 cfdata_t
933 config_search_loc(cfsubmatch_t fn, device_t parent,
934 		  const char *ifattr, const int *locs, void *aux)
935 {
936 	struct cftable *ct;
937 	cfdata_t cf;
938 	struct matchinfo m;
939 
940 	KASSERT(config_initialized);
941 	KASSERT(!ifattr || cfdriver_get_iattr(parent->dv_cfdriver, ifattr));
942 
943 	m.fn = fn;
944 	m.parent = parent;
945 	m.locs = locs;
946 	m.aux = aux;
947 	m.match = NULL;
948 	m.pri = 0;
949 
950 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
951 		for (cf = ct->ct_cfdata; cf->cf_name; cf++) {
952 
953 			/* We don't match root nodes here. */
954 			if (!cf->cf_pspec)
955 				continue;
956 
957 			/*
958 			 * Skip cf if no longer eligible, otherwise scan
959 			 * through parents for one matching `parent', and
960 			 * try match function.
961 			 */
962 			if (cf->cf_fstate == FSTATE_FOUND)
963 				continue;
964 			if (cf->cf_fstate == FSTATE_DNOTFOUND ||
965 			    cf->cf_fstate == FSTATE_DSTAR)
966 				continue;
967 
968 			/*
969 			 * If an interface attribute was specified,
970 			 * consider only children which attach to
971 			 * that attribute.
972 			 */
973 			if (ifattr && !STREQ(ifattr, cf->cf_pspec->cfp_iattr))
974 				continue;
975 
976 			if (cfparent_match(parent, cf->cf_pspec))
977 				mapply(&m, cf);
978 		}
979 	}
980 	return m.match;
981 }
982 
983 cfdata_t
984 config_search_ia(cfsubmatch_t fn, device_t parent, const char *ifattr,
985     void *aux)
986 {
987 
988 	return config_search_loc(fn, parent, ifattr, NULL, aux);
989 }
990 
991 /*
992  * Find the given root device.
993  * This is much like config_search, but there is no parent.
994  * Don't bother with multiple cfdata tables; the root node
995  * must always be in the initial table.
996  */
997 cfdata_t
998 config_rootsearch(cfsubmatch_t fn, const char *rootname, void *aux)
999 {
1000 	cfdata_t cf;
1001 	const short *p;
1002 	struct matchinfo m;
1003 
1004 	m.fn = fn;
1005 	m.parent = ROOT;
1006 	m.aux = aux;
1007 	m.match = NULL;
1008 	m.pri = 0;
1009 	m.locs = 0;
1010 	/*
1011 	 * Look at root entries for matching name.  We do not bother
1012 	 * with found-state here since only one root should ever be
1013 	 * searched (and it must be done first).
1014 	 */
1015 	for (p = cfroots; *p >= 0; p++) {
1016 		cf = &cfdata[*p];
1017 		if (strcmp(cf->cf_name, rootname) == 0)
1018 			mapply(&m, cf);
1019 	}
1020 	return m.match;
1021 }
1022 
1023 static const char * const msgs[3] = { "", " not configured\n", " unsupported\n" };
1024 
1025 /*
1026  * The given `aux' argument describes a device that has been found
1027  * on the given parent, but not necessarily configured.  Locate the
1028  * configuration data for that device (using the submatch function
1029  * provided, or using candidates' cd_match configuration driver
1030  * functions) and attach it, and return true.  If the device was
1031  * not configured, call the given `print' function and return 0.
1032  */
1033 device_t
1034 config_found_sm_loc(device_t parent,
1035 		const char *ifattr, const int *locs, void *aux,
1036 		cfprint_t print, cfsubmatch_t submatch)
1037 {
1038 	cfdata_t cf;
1039 
1040 #if defined(SPLASHSCREEN) && defined(SPLASHSCREEN_PROGRESS)
1041 	if (splash_progress_state)
1042 		splash_progress_update(splash_progress_state);
1043 #endif
1044 
1045 	if ((cf = config_search_loc(submatch, parent, ifattr, locs, aux)))
1046 		return(config_attach_loc(parent, cf, locs, aux, print));
1047 	if (print) {
1048 		if (config_do_twiddle && cold)
1049 			twiddle();
1050 		aprint_normal("%s", msgs[(*print)(aux, device_xname(parent))]);
1051 	}
1052 
1053 #if defined(SPLASHSCREEN) && defined(SPLASHSCREEN_PROGRESS)
1054 	if (splash_progress_state)
1055 		splash_progress_update(splash_progress_state);
1056 #endif
1057 
1058 	return NULL;
1059 }
1060 
1061 device_t
1062 config_found_ia(device_t parent, const char *ifattr, void *aux,
1063     cfprint_t print)
1064 {
1065 
1066 	return config_found_sm_loc(parent, ifattr, NULL, aux, print, NULL);
1067 }
1068 
1069 device_t
1070 config_found(device_t parent, void *aux, cfprint_t print)
1071 {
1072 
1073 	return config_found_sm_loc(parent, NULL, NULL, aux, print, NULL);
1074 }
1075 
1076 /*
1077  * As above, but for root devices.
1078  */
1079 device_t
1080 config_rootfound(const char *rootname, void *aux)
1081 {
1082 	cfdata_t cf;
1083 
1084 	if ((cf = config_rootsearch((cfsubmatch_t)NULL, rootname, aux)) != NULL)
1085 		return config_attach(ROOT, cf, aux, (cfprint_t)NULL);
1086 	aprint_error("root device %s not configured\n", rootname);
1087 	return NULL;
1088 }
1089 
1090 /* just like sprintf(buf, "%d") except that it works from the end */
1091 static char *
1092 number(char *ep, int n)
1093 {
1094 
1095 	*--ep = 0;
1096 	while (n >= 10) {
1097 		*--ep = (n % 10) + '0';
1098 		n /= 10;
1099 	}
1100 	*--ep = n + '0';
1101 	return ep;
1102 }
1103 
1104 /*
1105  * Expand the size of the cd_devs array if necessary.
1106  */
1107 static void
1108 config_makeroom(int n, struct cfdriver *cd)
1109 {
1110 	int old, new;
1111 	device_t *nsp;
1112 
1113 	if (n < cd->cd_ndevs)
1114 		return;
1115 
1116 	/*
1117 	 * Need to expand the array.
1118 	 */
1119 	old = cd->cd_ndevs;
1120 	if (old == 0)
1121 		new = 4;
1122 	else
1123 		new = old * 2;
1124 	while (new <= n)
1125 		new *= 2;
1126 	cd->cd_ndevs = new;
1127 	nsp = kmem_alloc(sizeof(device_t [new]), KM_SLEEP);
1128 	if (nsp == NULL)
1129 		panic("config_attach: %sing dev array",
1130 		    old != 0 ? "expand" : "creat");
1131 	memset(nsp + old, 0, sizeof(device_t [new - old]));
1132 	if (old != 0) {
1133 		memcpy(nsp, cd->cd_devs, sizeof(device_t [old]));
1134 		kmem_free(cd->cd_devs, sizeof(device_t [old]));
1135 	}
1136 	cd->cd_devs = nsp;
1137 }
1138 
1139 static void
1140 config_devlink(device_t dev)
1141 {
1142 	struct cfdriver *cd = dev->dv_cfdriver;
1143 
1144 	/* put this device in the devices array */
1145 	config_makeroom(dev->dv_unit, cd);
1146 	if (cd->cd_devs[dev->dv_unit])
1147 		panic("config_attach: duplicate %s", device_xname(dev));
1148 	cd->cd_devs[dev->dv_unit] = dev;
1149 
1150 	/* It is safe to add a device to the tail of the list while
1151 	 * readers are in the list, but not while a writer is in
1152 	 * the list.  Wait for any writer to complete.
1153 	 */
1154 	mutex_enter(&alldevs_mtx);
1155 	while (alldevs_nwrite != 0 && alldevs_writer != curlwp)
1156 		cv_wait(&alldevs_cv, &alldevs_mtx);
1157 	TAILQ_INSERT_TAIL(&alldevs, dev, dv_list);	/* link up */
1158 	cv_signal(&alldevs_cv);
1159 	mutex_exit(&alldevs_mtx);
1160 }
1161 
1162 static void
1163 config_devunlink(device_t dev)
1164 {
1165 	struct cfdriver *cd = dev->dv_cfdriver;
1166 	int i;
1167 
1168 	/* Unlink from device list. */
1169 	TAILQ_REMOVE(&alldevs, dev, dv_list);
1170 
1171 	/* Remove from cfdriver's array. */
1172 	cd->cd_devs[dev->dv_unit] = NULL;
1173 
1174 	/*
1175 	 * If the device now has no units in use, deallocate its softc array.
1176 	 */
1177 	for (i = 0; i < cd->cd_ndevs; i++) {
1178 		if (cd->cd_devs[i] != NULL)
1179 			return;
1180 	}
1181 	/* nothing found; deallocate */
1182 	kmem_free(cd->cd_devs, sizeof(device_t [cd->cd_ndevs]));
1183 	cd->cd_devs = NULL;
1184 	cd->cd_ndevs = 0;
1185 }
1186 
1187 static device_t
1188 config_devalloc(const device_t parent, const cfdata_t cf, const int *locs)
1189 {
1190 	struct cfdriver *cd;
1191 	struct cfattach *ca;
1192 	size_t lname, lunit;
1193 	const char *xunit;
1194 	int myunit;
1195 	char num[10];
1196 	device_t dev;
1197 	void *dev_private;
1198 	const struct cfiattrdata *ia;
1199 	device_lock_t dvl;
1200 
1201 	cd = config_cfdriver_lookup(cf->cf_name);
1202 	if (cd == NULL)
1203 		return NULL;
1204 
1205 	ca = config_cfattach_lookup_cd(cd, cf->cf_atname);
1206 	if (ca == NULL)
1207 		return NULL;
1208 
1209 	if ((ca->ca_flags & DVF_PRIV_ALLOC) == 0 &&
1210 	    ca->ca_devsize < sizeof(struct device))
1211 		panic("config_devalloc: %s", cf->cf_atname);
1212 
1213 #ifndef __BROKEN_CONFIG_UNIT_USAGE
1214 	if (cf->cf_fstate == FSTATE_STAR) {
1215 		for (myunit = cf->cf_unit; myunit < cd->cd_ndevs; myunit++)
1216 			if (cd->cd_devs[myunit] == NULL)
1217 				break;
1218 		/*
1219 		 * myunit is now the unit of the first NULL device pointer,
1220 		 * or max(cd->cd_ndevs,cf->cf_unit).
1221 		 */
1222 	} else {
1223 		myunit = cf->cf_unit;
1224 		if (myunit < cd->cd_ndevs && cd->cd_devs[myunit] != NULL)
1225 			return NULL;
1226 	}
1227 #else
1228 	myunit = cf->cf_unit;
1229 #endif /* ! __BROKEN_CONFIG_UNIT_USAGE */
1230 
1231 	/* compute length of name and decimal expansion of unit number */
1232 	lname = strlen(cd->cd_name);
1233 	xunit = number(&num[sizeof(num)], myunit);
1234 	lunit = &num[sizeof(num)] - xunit;
1235 	if (lname + lunit > sizeof(dev->dv_xname))
1236 		panic("config_devalloc: device name too long");
1237 
1238 	/* get memory for all device vars */
1239 	KASSERT((ca->ca_flags & DVF_PRIV_ALLOC) || ca->ca_devsize >= sizeof(struct device));
1240 	if (ca->ca_devsize > 0) {
1241 		dev_private = kmem_zalloc(ca->ca_devsize, KM_SLEEP);
1242 		if (dev_private == NULL)
1243 			panic("config_devalloc: memory allocation for device softc failed");
1244 	} else {
1245 		KASSERT(ca->ca_flags & DVF_PRIV_ALLOC);
1246 		dev_private = NULL;
1247 	}
1248 
1249 	if ((ca->ca_flags & DVF_PRIV_ALLOC) != 0) {
1250 		dev = kmem_zalloc(sizeof(*dev), KM_SLEEP);
1251 	} else {
1252 		dev = dev_private;
1253 	}
1254 	if (dev == NULL)
1255 		panic("config_devalloc: memory allocation for device_t failed");
1256 
1257 	dvl = device_getlock(dev);
1258 
1259 	mutex_init(&dvl->dvl_mtx, MUTEX_DEFAULT, IPL_NONE);
1260 	cv_init(&dvl->dvl_cv, "pmfsusp");
1261 
1262 	dev->dv_class = cd->cd_class;
1263 	dev->dv_cfdata = cf;
1264 	dev->dv_cfdriver = cd;
1265 	dev->dv_cfattach = ca;
1266 	dev->dv_unit = myunit;
1267 	dev->dv_activity_count = 0;
1268 	dev->dv_activity_handlers = NULL;
1269 	dev->dv_private = dev_private;
1270 	memcpy(dev->dv_xname, cd->cd_name, lname);
1271 	memcpy(dev->dv_xname + lname, xunit, lunit);
1272 	dev->dv_parent = parent;
1273 	if (parent != NULL)
1274 		dev->dv_depth = parent->dv_depth + 1;
1275 	else
1276 		dev->dv_depth = 0;
1277 	dev->dv_flags = DVF_ACTIVE;	/* always initially active */
1278 	dev->dv_flags |= ca->ca_flags;	/* inherit flags from class */
1279 	if (locs) {
1280 		KASSERT(parent); /* no locators at root */
1281 		ia = cfiattr_lookup(cf->cf_pspec->cfp_iattr,
1282 				    parent->dv_cfdriver);
1283 		dev->dv_locators =
1284 		    kmem_alloc(sizeof(int [ia->ci_loclen + 1]), KM_SLEEP);
1285 		*dev->dv_locators++ = sizeof(int [ia->ci_loclen + 1]);
1286 		memcpy(dev->dv_locators, locs, sizeof(int [ia->ci_loclen]));
1287 	}
1288 	dev->dv_properties = prop_dictionary_create();
1289 	KASSERT(dev->dv_properties != NULL);
1290 
1291 	prop_dictionary_set_cstring_nocopy(dev->dv_properties,
1292 	    "device-driver", dev->dv_cfdriver->cd_name);
1293 	prop_dictionary_set_uint16(dev->dv_properties,
1294 	    "device-unit", dev->dv_unit);
1295 
1296 	return dev;
1297 }
1298 
1299 static void
1300 config_devdealloc(device_t dev)
1301 {
1302 	device_lock_t dvl = device_getlock(dev);
1303 	int priv = (dev->dv_flags & DVF_PRIV_ALLOC);
1304 
1305 	cv_destroy(&dvl->dvl_cv);
1306 	mutex_destroy(&dvl->dvl_mtx);
1307 
1308 	KASSERT(dev->dv_properties != NULL);
1309 	prop_object_release(dev->dv_properties);
1310 
1311 	if (dev->dv_activity_handlers)
1312 		panic("config_devdealloc with registered handlers");
1313 
1314 	if (dev->dv_locators) {
1315 		size_t amount = *--dev->dv_locators;
1316 		kmem_free(dev->dv_locators, amount);
1317 	}
1318 
1319 	if (dev->dv_cfattach->ca_devsize > 0)
1320 		kmem_free(dev->dv_private, dev->dv_cfattach->ca_devsize);
1321 	if (priv)
1322 		kmem_free(dev, sizeof(*dev));
1323 }
1324 
1325 /*
1326  * Attach a found device.
1327  */
1328 device_t
1329 config_attach_loc(device_t parent, cfdata_t cf,
1330 	const int *locs, void *aux, cfprint_t print)
1331 {
1332 	device_t dev;
1333 	struct cftable *ct;
1334 	const char *drvname;
1335 
1336 #if defined(SPLASHSCREEN) && defined(SPLASHSCREEN_PROGRESS)
1337 	if (splash_progress_state)
1338 		splash_progress_update(splash_progress_state);
1339 #endif
1340 
1341 	dev = config_devalloc(parent, cf, locs);
1342 	if (!dev)
1343 		panic("config_attach: allocation of device softc failed");
1344 
1345 	/* XXX redundant - see below? */
1346 	if (cf->cf_fstate != FSTATE_STAR) {
1347 		KASSERT(cf->cf_fstate == FSTATE_NOTFOUND);
1348 		cf->cf_fstate = FSTATE_FOUND;
1349 	}
1350 #ifdef __BROKEN_CONFIG_UNIT_USAGE
1351 	  else
1352 		cf->cf_unit++;
1353 #endif
1354 
1355 	config_devlink(dev);
1356 
1357 	if (config_do_twiddle && cold)
1358 		twiddle();
1359 	else
1360 		aprint_naive("Found ");
1361 	/*
1362 	 * We want the next two printfs for normal, verbose, and quiet,
1363 	 * but not silent (in which case, we're twiddling, instead).
1364 	 */
1365 	if (parent == ROOT) {
1366 		aprint_naive("%s (root)", device_xname(dev));
1367 		aprint_normal("%s (root)", device_xname(dev));
1368 	} else {
1369 		aprint_naive("%s at %s", device_xname(dev), device_xname(parent));
1370 		aprint_normal("%s at %s", device_xname(dev), device_xname(parent));
1371 		if (print)
1372 			(void) (*print)(aux, NULL);
1373 	}
1374 
1375 	/*
1376 	 * Before attaching, clobber any unfound devices that are
1377 	 * otherwise identical.
1378 	 * XXX code above is redundant?
1379 	 */
1380 	drvname = dev->dv_cfdriver->cd_name;
1381 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
1382 		for (cf = ct->ct_cfdata; cf->cf_name; cf++) {
1383 			if (STREQ(cf->cf_name, drvname) &&
1384 			    cf->cf_unit == dev->dv_unit) {
1385 				if (cf->cf_fstate == FSTATE_NOTFOUND)
1386 					cf->cf_fstate = FSTATE_FOUND;
1387 #ifdef __BROKEN_CONFIG_UNIT_USAGE
1388 				/*
1389 				 * Bump the unit number on all starred cfdata
1390 				 * entries for this device.
1391 				 */
1392 				if (cf->cf_fstate == FSTATE_STAR)
1393 					cf->cf_unit++;
1394 #endif /* __BROKEN_CONFIG_UNIT_USAGE */
1395 			}
1396 		}
1397 	}
1398 #ifdef __HAVE_DEVICE_REGISTER
1399 	device_register(dev, aux);
1400 #endif
1401 
1402 	/* Let userland know */
1403 	devmon_report_device(dev, true);
1404 
1405 #if defined(SPLASHSCREEN) && defined(SPLASHSCREEN_PROGRESS)
1406 	if (splash_progress_state)
1407 		splash_progress_update(splash_progress_state);
1408 #endif
1409 	(*dev->dv_cfattach->ca_attach)(parent, dev, aux);
1410 #if defined(SPLASHSCREEN) && defined(SPLASHSCREEN_PROGRESS)
1411 	if (splash_progress_state)
1412 		splash_progress_update(splash_progress_state);
1413 #endif
1414 
1415 	if (!device_pmf_is_registered(dev))
1416 		aprint_debug_dev(dev, "WARNING: power management not supported\n");
1417 
1418 	config_process_deferred(&deferred_config_queue, dev);
1419 	return dev;
1420 }
1421 
1422 device_t
1423 config_attach(device_t parent, cfdata_t cf, void *aux, cfprint_t print)
1424 {
1425 
1426 	return config_attach_loc(parent, cf, NULL, aux, print);
1427 }
1428 
1429 /*
1430  * As above, but for pseudo-devices.  Pseudo-devices attached in this
1431  * way are silently inserted into the device tree, and their children
1432  * attached.
1433  *
1434  * Note that because pseudo-devices are attached silently, any information
1435  * the attach routine wishes to print should be prefixed with the device
1436  * name by the attach routine.
1437  */
1438 device_t
1439 config_attach_pseudo(cfdata_t cf)
1440 {
1441 	device_t dev;
1442 
1443 	dev = config_devalloc(ROOT, cf, NULL);
1444 	if (!dev)
1445 		return NULL;
1446 
1447 	/* XXX mark busy in cfdata */
1448 
1449 	if (cf->cf_fstate != FSTATE_STAR) {
1450 		KASSERT(cf->cf_fstate == FSTATE_NOTFOUND);
1451 		cf->cf_fstate = FSTATE_FOUND;
1452 	}
1453 
1454 	config_devlink(dev);
1455 
1456 #if 0	/* XXXJRT not yet */
1457 #ifdef __HAVE_DEVICE_REGISTER
1458 	device_register(dev, NULL);	/* like a root node */
1459 #endif
1460 #endif
1461 	(*dev->dv_cfattach->ca_attach)(ROOT, dev, NULL);
1462 	config_process_deferred(&deferred_config_queue, dev);
1463 	return dev;
1464 }
1465 
1466 /*
1467  * Detach a device.  Optionally forced (e.g. because of hardware
1468  * removal) and quiet.  Returns zero if successful, non-zero
1469  * (an error code) otherwise.
1470  *
1471  * Note that this code wants to be run from a process context, so
1472  * that the detach can sleep to allow processes which have a device
1473  * open to run and unwind their stacks.
1474  */
1475 int
1476 config_detach(device_t dev, int flags)
1477 {
1478 	struct cftable *ct;
1479 	cfdata_t cf;
1480 	const struct cfattach *ca;
1481 	struct cfdriver *cd;
1482 #ifdef DIAGNOSTIC
1483 	device_t d;
1484 #endif
1485 	int rv = 0;
1486 
1487 #ifdef DIAGNOSTIC
1488 	cf = dev->dv_cfdata;
1489 	if (cf != NULL && cf->cf_fstate != FSTATE_FOUND &&
1490 	    cf->cf_fstate != FSTATE_STAR)
1491 		panic("config_detach: %s: bad device fstate %d",
1492 		    device_xname(dev), cf ? cf->cf_fstate : -1);
1493 #endif
1494 	cd = dev->dv_cfdriver;
1495 	KASSERT(cd != NULL);
1496 
1497 	ca = dev->dv_cfattach;
1498 	KASSERT(ca != NULL);
1499 
1500 	KASSERT(curlwp != NULL);
1501 	mutex_enter(&alldevs_mtx);
1502 	if (alldevs_nwrite > 0 && alldevs_writer == NULL)
1503 		;
1504 	else while (alldevs_nread != 0 ||
1505 	       (alldevs_nwrite != 0 && alldevs_writer != curlwp))
1506 		cv_wait(&alldevs_cv, &alldevs_mtx);
1507 	if (alldevs_nwrite++ == 0)
1508 		alldevs_writer = curlwp;
1509 	mutex_exit(&alldevs_mtx);
1510 
1511 	/*
1512 	 * Ensure the device is deactivated.  If the device doesn't
1513 	 * have an activation entry point, we allow DVF_ACTIVE to
1514 	 * remain set.  Otherwise, if DVF_ACTIVE is still set, the
1515 	 * device is busy, and the detach fails.
1516 	 */
1517 	if (!detachall &&
1518 	    (flags & (DETACH_SHUTDOWN|DETACH_FORCE)) == DETACH_SHUTDOWN &&
1519 	    (dev->dv_flags & DVF_DETACH_SHUTDOWN) == 0) {
1520 		rv = EBUSY;	/* XXX EOPNOTSUPP? */
1521 	} else if ((rv = config_deactivate(dev)) == EOPNOTSUPP)
1522 		rv = 0;	/* Do not treat EOPNOTSUPP as an error */
1523 
1524 	/*
1525 	 * Try to detach the device.  If that's not possible, then
1526 	 * we either panic() (for the forced but failed case), or
1527 	 * return an error.
1528 	 */
1529 	if (rv == 0) {
1530 		if (ca->ca_detach != NULL)
1531 			rv = (*ca->ca_detach)(dev, flags);
1532 		else
1533 			rv = EOPNOTSUPP;
1534 	}
1535 	if (rv != 0) {
1536 		if ((flags & DETACH_FORCE) == 0)
1537 			goto out;
1538 		else
1539 			panic("config_detach: forced detach of %s failed (%d)",
1540 			    device_xname(dev), rv);
1541 	}
1542 
1543 	dev->dv_flags &= ~DVF_ACTIVE;
1544 
1545 	/*
1546 	 * The device has now been successfully detached.
1547 	 */
1548 
1549 	/* Let userland know */
1550 	devmon_report_device(dev, false);
1551 
1552 #ifdef DIAGNOSTIC
1553 	/*
1554 	 * Sanity: If you're successfully detached, you should have no
1555 	 * children.  (Note that because children must be attached
1556 	 * after parents, we only need to search the latter part of
1557 	 * the list.)
1558 	 */
1559 	for (d = TAILQ_NEXT(dev, dv_list); d != NULL;
1560 	    d = TAILQ_NEXT(d, dv_list)) {
1561 		if (d->dv_parent == dev) {
1562 			printf("config_detach: detached device %s"
1563 			    " has children %s\n", device_xname(dev), device_xname(d));
1564 			panic("config_detach");
1565 		}
1566 	}
1567 #endif
1568 
1569 	/* notify the parent that the child is gone */
1570 	if (dev->dv_parent) {
1571 		device_t p = dev->dv_parent;
1572 		if (p->dv_cfattach->ca_childdetached)
1573 			(*p->dv_cfattach->ca_childdetached)(p, dev);
1574 	}
1575 
1576 	/*
1577 	 * Mark cfdata to show that the unit can be reused, if possible.
1578 	 */
1579 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
1580 		for (cf = ct->ct_cfdata; cf->cf_name; cf++) {
1581 			if (STREQ(cf->cf_name, cd->cd_name)) {
1582 				if (cf->cf_fstate == FSTATE_FOUND &&
1583 				    cf->cf_unit == dev->dv_unit)
1584 					cf->cf_fstate = FSTATE_NOTFOUND;
1585 #ifdef __BROKEN_CONFIG_UNIT_USAGE
1586 				/*
1587 				 * Note that we can only re-use a starred
1588 				 * unit number if the unit being detached
1589 				 * had the last assigned unit number.
1590 				 */
1591 				if (cf->cf_fstate == FSTATE_STAR &&
1592 				    cf->cf_unit == dev->dv_unit + 1)
1593 					cf->cf_unit--;
1594 #endif /* __BROKEN_CONFIG_UNIT_USAGE */
1595 			}
1596 		}
1597 	}
1598 
1599 	config_devunlink(dev);
1600 
1601 	if (dev->dv_cfdata != NULL && (flags & DETACH_QUIET) == 0)
1602 		aprint_normal_dev(dev, "detached\n");
1603 
1604 	config_devdealloc(dev);
1605 
1606 out:
1607 	mutex_enter(&alldevs_mtx);
1608 	KASSERT(alldevs_nwrite != 0);
1609 	if (--alldevs_nwrite == 0)
1610 		alldevs_writer = NULL;
1611 	cv_signal(&alldevs_cv);
1612 	mutex_exit(&alldevs_mtx);
1613 	return rv;
1614 }
1615 
1616 int
1617 config_detach_children(device_t parent, int flags)
1618 {
1619 	device_t dv;
1620 	deviter_t di;
1621 	int error = 0;
1622 
1623 	for (dv = deviter_first(&di, DEVITER_F_RW); dv != NULL;
1624 	     dv = deviter_next(&di)) {
1625 		if (device_parent(dv) != parent)
1626 			continue;
1627 		if ((error = config_detach(dv, flags)) != 0)
1628 			break;
1629 	}
1630 	deviter_release(&di);
1631 	return error;
1632 }
1633 
1634 device_t
1635 shutdown_first(struct shutdown_state *s)
1636 {
1637 	if (!s->initialized) {
1638 		deviter_init(&s->di, DEVITER_F_SHUTDOWN|DEVITER_F_LEAVES_FIRST);
1639 		s->initialized = true;
1640 	}
1641 	return shutdown_next(s);
1642 }
1643 
1644 device_t
1645 shutdown_next(struct shutdown_state *s)
1646 {
1647 	device_t dv;
1648 
1649 	while ((dv = deviter_next(&s->di)) != NULL && !device_is_active(dv))
1650 		;
1651 
1652 	if (dv == NULL)
1653 		s->initialized = false;
1654 
1655 	return dv;
1656 }
1657 
1658 bool
1659 config_detach_all(int how)
1660 {
1661 	static struct shutdown_state s;
1662 	device_t curdev;
1663 	bool progress = false;
1664 
1665 	if ((how & RB_NOSYNC) != 0)
1666 		return false;
1667 
1668 	for (curdev = shutdown_first(&s); curdev != NULL;
1669 	     curdev = shutdown_next(&s)) {
1670 		aprint_debug(" detaching %s, ", device_xname(curdev));
1671 		if (config_detach(curdev, DETACH_SHUTDOWN) == 0) {
1672 			progress = true;
1673 			aprint_debug("success.");
1674 		} else
1675 			aprint_debug("failed.");
1676 	}
1677 	return progress;
1678 }
1679 
1680 int
1681 config_activate(device_t dev)
1682 {
1683 	const struct cfattach *ca = dev->dv_cfattach;
1684 	int rv = 0, oflags = dev->dv_flags;
1685 
1686 	if (ca->ca_activate == NULL)
1687 		return EOPNOTSUPP;
1688 
1689 	if ((dev->dv_flags & DVF_ACTIVE) == 0) {
1690 		dev->dv_flags |= DVF_ACTIVE;
1691 		rv = (*ca->ca_activate)(dev, DVACT_ACTIVATE);
1692 		if (rv)
1693 			dev->dv_flags = oflags;
1694 	}
1695 	return rv;
1696 }
1697 
1698 int
1699 config_deactivate(device_t dev)
1700 {
1701 	const struct cfattach *ca = dev->dv_cfattach;
1702 	int rv = 0, oflags = dev->dv_flags;
1703 
1704 	if (ca->ca_activate == NULL)
1705 		return EOPNOTSUPP;
1706 
1707 	if (dev->dv_flags & DVF_ACTIVE) {
1708 		dev->dv_flags &= ~DVF_ACTIVE;
1709 		rv = (*ca->ca_activate)(dev, DVACT_DEACTIVATE);
1710 		if (rv)
1711 			dev->dv_flags = oflags;
1712 	}
1713 	return rv;
1714 }
1715 
1716 /*
1717  * Defer the configuration of the specified device until all
1718  * of its parent's devices have been attached.
1719  */
1720 void
1721 config_defer(device_t dev, void (*func)(device_t))
1722 {
1723 	struct deferred_config *dc;
1724 
1725 	if (dev->dv_parent == NULL)
1726 		panic("config_defer: can't defer config of a root device");
1727 
1728 #ifdef DIAGNOSTIC
1729 	for (dc = TAILQ_FIRST(&deferred_config_queue); dc != NULL;
1730 	     dc = TAILQ_NEXT(dc, dc_queue)) {
1731 		if (dc->dc_dev == dev)
1732 			panic("config_defer: deferred twice");
1733 	}
1734 #endif
1735 
1736 	dc = kmem_alloc(sizeof(*dc), KM_SLEEP);
1737 	if (dc == NULL)
1738 		panic("config_defer: unable to allocate callback");
1739 
1740 	dc->dc_dev = dev;
1741 	dc->dc_func = func;
1742 	TAILQ_INSERT_TAIL(&deferred_config_queue, dc, dc_queue);
1743 	config_pending_incr();
1744 }
1745 
1746 /*
1747  * Defer some autoconfiguration for a device until after interrupts
1748  * are enabled.
1749  */
1750 void
1751 config_interrupts(device_t dev, void (*func)(device_t))
1752 {
1753 	struct deferred_config *dc;
1754 
1755 	/*
1756 	 * If interrupts are enabled, callback now.
1757 	 */
1758 	if (cold == 0) {
1759 		(*func)(dev);
1760 		return;
1761 	}
1762 
1763 #ifdef DIAGNOSTIC
1764 	for (dc = TAILQ_FIRST(&interrupt_config_queue); dc != NULL;
1765 	     dc = TAILQ_NEXT(dc, dc_queue)) {
1766 		if (dc->dc_dev == dev)
1767 			panic("config_interrupts: deferred twice");
1768 	}
1769 #endif
1770 
1771 	dc = kmem_alloc(sizeof(*dc), KM_SLEEP);
1772 	if (dc == NULL)
1773 		panic("config_interrupts: unable to allocate callback");
1774 
1775 	dc->dc_dev = dev;
1776 	dc->dc_func = func;
1777 	TAILQ_INSERT_TAIL(&interrupt_config_queue, dc, dc_queue);
1778 	config_pending_incr();
1779 }
1780 
1781 /*
1782  * Process a deferred configuration queue.
1783  */
1784 static void
1785 config_process_deferred(struct deferred_config_head *queue,
1786     device_t parent)
1787 {
1788 	struct deferred_config *dc, *ndc;
1789 
1790 	for (dc = TAILQ_FIRST(queue); dc != NULL; dc = ndc) {
1791 		ndc = TAILQ_NEXT(dc, dc_queue);
1792 		if (parent == NULL || dc->dc_dev->dv_parent == parent) {
1793 			TAILQ_REMOVE(queue, dc, dc_queue);
1794 			(*dc->dc_func)(dc->dc_dev);
1795 			kmem_free(dc, sizeof(*dc));
1796 			config_pending_decr();
1797 		}
1798 	}
1799 }
1800 
1801 /*
1802  * Manipulate the config_pending semaphore.
1803  */
1804 void
1805 config_pending_incr(void)
1806 {
1807 
1808 	mutex_enter(&config_misc_lock);
1809 	config_pending++;
1810 	mutex_exit(&config_misc_lock);
1811 }
1812 
1813 void
1814 config_pending_decr(void)
1815 {
1816 
1817 #ifdef DIAGNOSTIC
1818 	if (config_pending == 0)
1819 		panic("config_pending_decr: config_pending == 0");
1820 #endif
1821 	mutex_enter(&config_misc_lock);
1822 	config_pending--;
1823 	if (config_pending == 0)
1824 		cv_broadcast(&config_misc_cv);
1825 	mutex_exit(&config_misc_lock);
1826 }
1827 
1828 /*
1829  * Register a "finalization" routine.  Finalization routines are
1830  * called iteratively once all real devices have been found during
1831  * autoconfiguration, for as long as any one finalizer has done
1832  * any work.
1833  */
1834 int
1835 config_finalize_register(device_t dev, int (*fn)(device_t))
1836 {
1837 	struct finalize_hook *f;
1838 
1839 	/*
1840 	 * If finalization has already been done, invoke the
1841 	 * callback function now.
1842 	 */
1843 	if (config_finalize_done) {
1844 		while ((*fn)(dev) != 0)
1845 			/* loop */ ;
1846 	}
1847 
1848 	/* Ensure this isn't already on the list. */
1849 	TAILQ_FOREACH(f, &config_finalize_list, f_list) {
1850 		if (f->f_func == fn && f->f_dev == dev)
1851 			return EEXIST;
1852 	}
1853 
1854 	f = kmem_alloc(sizeof(*f), KM_SLEEP);
1855 	f->f_func = fn;
1856 	f->f_dev = dev;
1857 	TAILQ_INSERT_TAIL(&config_finalize_list, f, f_list);
1858 
1859 	return 0;
1860 }
1861 
1862 void
1863 config_finalize(void)
1864 {
1865 	struct finalize_hook *f;
1866 	struct pdevinit *pdev;
1867 	extern struct pdevinit pdevinit[];
1868 	int errcnt, rv;
1869 
1870 	/*
1871 	 * Now that device driver threads have been created, wait for
1872 	 * them to finish any deferred autoconfiguration.
1873 	 */
1874 	mutex_enter(&config_misc_lock);
1875 	while (config_pending != 0)
1876 		cv_wait(&config_misc_cv, &config_misc_lock);
1877 	mutex_exit(&config_misc_lock);
1878 
1879 	KERNEL_LOCK(1, NULL);
1880 
1881 	/* Attach pseudo-devices. */
1882 	for (pdev = pdevinit; pdev->pdev_attach != NULL; pdev++)
1883 		(*pdev->pdev_attach)(pdev->pdev_count);
1884 
1885 	/* Run the hooks until none of them does any work. */
1886 	do {
1887 		rv = 0;
1888 		TAILQ_FOREACH(f, &config_finalize_list, f_list)
1889 			rv |= (*f->f_func)(f->f_dev);
1890 	} while (rv != 0);
1891 
1892 	config_finalize_done = 1;
1893 
1894 	/* Now free all the hooks. */
1895 	while ((f = TAILQ_FIRST(&config_finalize_list)) != NULL) {
1896 		TAILQ_REMOVE(&config_finalize_list, f, f_list);
1897 		kmem_free(f, sizeof(*f));
1898 	}
1899 
1900 	KERNEL_UNLOCK_ONE(NULL);
1901 
1902 	errcnt = aprint_get_error_count();
1903 	if ((boothowto & (AB_QUIET|AB_SILENT)) != 0 &&
1904 	    (boothowto & AB_VERBOSE) == 0) {
1905 		mutex_enter(&config_misc_lock);
1906 		if (config_do_twiddle) {
1907 			config_do_twiddle = 0;
1908 			printf_nolog(" done.\n");
1909 		}
1910 		mutex_exit(&config_misc_lock);
1911 		if (errcnt != 0) {
1912 			printf("WARNING: %d error%s while detecting hardware; "
1913 			    "check system log.\n", errcnt,
1914 			    errcnt == 1 ? "" : "s");
1915 		}
1916 	}
1917 }
1918 
1919 void
1920 config_twiddle_fn(void *cookie)
1921 {
1922 
1923 	mutex_enter(&config_misc_lock);
1924 	if (config_do_twiddle) {
1925 		twiddle();
1926 		callout_schedule(&config_twiddle_ch, mstohz(100));
1927 	}
1928 	mutex_exit(&config_misc_lock);
1929 }
1930 
1931 /*
1932  * device_lookup:
1933  *
1934  *	Look up a device instance for a given driver.
1935  */
1936 device_t
1937 device_lookup(cfdriver_t cd, int unit)
1938 {
1939 
1940 	if (unit < 0 || unit >= cd->cd_ndevs)
1941 		return NULL;
1942 
1943 	return cd->cd_devs[unit];
1944 }
1945 
1946 /*
1947  * device_lookup:
1948  *
1949  *	Look up a device instance for a given driver.
1950  */
1951 void *
1952 device_lookup_private(cfdriver_t cd, int unit)
1953 {
1954 	device_t dv;
1955 
1956 	if (unit < 0 || unit >= cd->cd_ndevs)
1957 		return NULL;
1958 
1959 	if ((dv = cd->cd_devs[unit]) == NULL)
1960 		return NULL;
1961 
1962 	return dv->dv_private;
1963 }
1964 
1965 /*
1966  * Accessor functions for the device_t type.
1967  */
1968 devclass_t
1969 device_class(device_t dev)
1970 {
1971 
1972 	return dev->dv_class;
1973 }
1974 
1975 cfdata_t
1976 device_cfdata(device_t dev)
1977 {
1978 
1979 	return dev->dv_cfdata;
1980 }
1981 
1982 cfdriver_t
1983 device_cfdriver(device_t dev)
1984 {
1985 
1986 	return dev->dv_cfdriver;
1987 }
1988 
1989 cfattach_t
1990 device_cfattach(device_t dev)
1991 {
1992 
1993 	return dev->dv_cfattach;
1994 }
1995 
1996 int
1997 device_unit(device_t dev)
1998 {
1999 
2000 	return dev->dv_unit;
2001 }
2002 
2003 const char *
2004 device_xname(device_t dev)
2005 {
2006 
2007 	return dev->dv_xname;
2008 }
2009 
2010 device_t
2011 device_parent(device_t dev)
2012 {
2013 
2014 	return dev->dv_parent;
2015 }
2016 
2017 bool
2018 device_is_active(device_t dev)
2019 {
2020 	int active_flags;
2021 
2022 	active_flags = DVF_ACTIVE;
2023 	active_flags |= DVF_CLASS_SUSPENDED;
2024 	active_flags |= DVF_DRIVER_SUSPENDED;
2025 	active_flags |= DVF_BUS_SUSPENDED;
2026 
2027 	return (dev->dv_flags & active_flags) == DVF_ACTIVE;
2028 }
2029 
2030 bool
2031 device_is_enabled(device_t dev)
2032 {
2033 	return (dev->dv_flags & DVF_ACTIVE) == DVF_ACTIVE;
2034 }
2035 
2036 bool
2037 device_has_power(device_t dev)
2038 {
2039 	int active_flags;
2040 
2041 	active_flags = DVF_ACTIVE | DVF_BUS_SUSPENDED;
2042 
2043 	return (dev->dv_flags & active_flags) == DVF_ACTIVE;
2044 }
2045 
2046 int
2047 device_locator(device_t dev, u_int locnum)
2048 {
2049 
2050 	KASSERT(dev->dv_locators != NULL);
2051 	return dev->dv_locators[locnum];
2052 }
2053 
2054 void *
2055 device_private(device_t dev)
2056 {
2057 
2058 	/*
2059 	 * The reason why device_private(NULL) is allowed is to simplify the
2060 	 * work of a lot of userspace request handlers (i.e., c/bdev
2061 	 * handlers) which grab cfdriver_t->cd_units[n].
2062 	 * It avoids having them test for it to be NULL and only then calling
2063 	 * device_private.
2064 	 */
2065 	return dev == NULL ? NULL : dev->dv_private;
2066 }
2067 
2068 prop_dictionary_t
2069 device_properties(device_t dev)
2070 {
2071 
2072 	return dev->dv_properties;
2073 }
2074 
2075 /*
2076  * device_is_a:
2077  *
2078  *	Returns true if the device is an instance of the specified
2079  *	driver.
2080  */
2081 bool
2082 device_is_a(device_t dev, const char *dname)
2083 {
2084 
2085 	return strcmp(dev->dv_cfdriver->cd_name, dname) == 0;
2086 }
2087 
2088 /*
2089  * device_find_by_xname:
2090  *
2091  *	Returns the device of the given name or NULL if it doesn't exist.
2092  */
2093 device_t
2094 device_find_by_xname(const char *name)
2095 {
2096 	device_t dv;
2097 	deviter_t di;
2098 
2099 	for (dv = deviter_first(&di, 0); dv != NULL; dv = deviter_next(&di)) {
2100 		if (strcmp(device_xname(dv), name) == 0)
2101 			break;
2102 	}
2103 	deviter_release(&di);
2104 
2105 	return dv;
2106 }
2107 
2108 /*
2109  * device_find_by_driver_unit:
2110  *
2111  *	Returns the device of the given driver name and unit or
2112  *	NULL if it doesn't exist.
2113  */
2114 device_t
2115 device_find_by_driver_unit(const char *name, int unit)
2116 {
2117 	struct cfdriver *cd;
2118 
2119 	if ((cd = config_cfdriver_lookup(name)) == NULL)
2120 		return NULL;
2121 	return device_lookup(cd, unit);
2122 }
2123 
2124 /*
2125  * Power management related functions.
2126  */
2127 
2128 bool
2129 device_pmf_is_registered(device_t dev)
2130 {
2131 	return (dev->dv_flags & DVF_POWER_HANDLERS) != 0;
2132 }
2133 
2134 bool
2135 device_pmf_driver_suspend(device_t dev PMF_FN_ARGS)
2136 {
2137 	if ((dev->dv_flags & DVF_DRIVER_SUSPENDED) != 0)
2138 		return true;
2139 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) == 0)
2140 		return false;
2141 	if (*dev->dv_driver_suspend != NULL &&
2142 	    !(*dev->dv_driver_suspend)(dev PMF_FN_CALL))
2143 		return false;
2144 
2145 	dev->dv_flags |= DVF_DRIVER_SUSPENDED;
2146 	return true;
2147 }
2148 
2149 bool
2150 device_pmf_driver_resume(device_t dev PMF_FN_ARGS)
2151 {
2152 	if ((dev->dv_flags & DVF_DRIVER_SUSPENDED) == 0)
2153 		return true;
2154 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) != 0)
2155 		return false;
2156 	if ((flags & PMF_F_SELF) != 0 && !device_is_self_suspended(dev))
2157 		return false;
2158 	if (*dev->dv_driver_resume != NULL &&
2159 	    !(*dev->dv_driver_resume)(dev PMF_FN_CALL))
2160 		return false;
2161 
2162 	dev->dv_flags &= ~DVF_DRIVER_SUSPENDED;
2163 	return true;
2164 }
2165 
2166 bool
2167 device_pmf_driver_shutdown(device_t dev, int how)
2168 {
2169 
2170 	if (*dev->dv_driver_shutdown != NULL &&
2171 	    !(*dev->dv_driver_shutdown)(dev, how))
2172 		return false;
2173 	return true;
2174 }
2175 
2176 bool
2177 device_pmf_driver_register(device_t dev,
2178     bool (*suspend)(device_t PMF_FN_PROTO),
2179     bool (*resume)(device_t PMF_FN_PROTO),
2180     bool (*shutdown)(device_t, int))
2181 {
2182 	dev->dv_driver_suspend = suspend;
2183 	dev->dv_driver_resume = resume;
2184 	dev->dv_driver_shutdown = shutdown;
2185 	dev->dv_flags |= DVF_POWER_HANDLERS;
2186 	return true;
2187 }
2188 
2189 static const char *
2190 curlwp_name(void)
2191 {
2192 	if (curlwp->l_name != NULL)
2193 		return curlwp->l_name;
2194 	else
2195 		return curlwp->l_proc->p_comm;
2196 }
2197 
2198 void
2199 device_pmf_driver_deregister(device_t dev)
2200 {
2201 	device_lock_t dvl = device_getlock(dev);
2202 
2203 	dev->dv_driver_suspend = NULL;
2204 	dev->dv_driver_resume = NULL;
2205 
2206 	mutex_enter(&dvl->dvl_mtx);
2207 	dev->dv_flags &= ~DVF_POWER_HANDLERS;
2208 	while (dvl->dvl_nlock > 0 || dvl->dvl_nwait > 0) {
2209 		/* Wake a thread that waits for the lock.  That
2210 		 * thread will fail to acquire the lock, and then
2211 		 * it will wake the next thread that waits for the
2212 		 * lock, or else it will wake us.
2213 		 */
2214 		cv_signal(&dvl->dvl_cv);
2215 		pmflock_debug(dev, __func__, __LINE__);
2216 		cv_wait(&dvl->dvl_cv, &dvl->dvl_mtx);
2217 		pmflock_debug(dev, __func__, __LINE__);
2218 	}
2219 	mutex_exit(&dvl->dvl_mtx);
2220 }
2221 
2222 bool
2223 device_pmf_driver_child_register(device_t dev)
2224 {
2225 	device_t parent = device_parent(dev);
2226 
2227 	if (parent == NULL || parent->dv_driver_child_register == NULL)
2228 		return true;
2229 	return (*parent->dv_driver_child_register)(dev);
2230 }
2231 
2232 void
2233 device_pmf_driver_set_child_register(device_t dev,
2234     bool (*child_register)(device_t))
2235 {
2236 	dev->dv_driver_child_register = child_register;
2237 }
2238 
2239 void
2240 device_pmf_self_resume(device_t dev PMF_FN_ARGS)
2241 {
2242 	pmflock_debug_with_flags(dev, __func__, __LINE__ PMF_FN_CALL);
2243 	if ((dev->dv_flags & DVF_SELF_SUSPENDED) != 0)
2244 		dev->dv_flags &= ~DVF_SELF_SUSPENDED;
2245 	pmflock_debug_with_flags(dev, __func__, __LINE__ PMF_FN_CALL);
2246 }
2247 
2248 bool
2249 device_is_self_suspended(device_t dev)
2250 {
2251 	return (dev->dv_flags & DVF_SELF_SUSPENDED) != 0;
2252 }
2253 
2254 void
2255 device_pmf_self_suspend(device_t dev PMF_FN_ARGS)
2256 {
2257 	bool self = (flags & PMF_F_SELF) != 0;
2258 
2259 	pmflock_debug_with_flags(dev, __func__, __LINE__ PMF_FN_CALL);
2260 
2261 	if (!self)
2262 		dev->dv_flags &= ~DVF_SELF_SUSPENDED;
2263 	else if (device_is_active(dev))
2264 		dev->dv_flags |= DVF_SELF_SUSPENDED;
2265 
2266 	pmflock_debug_with_flags(dev, __func__, __LINE__ PMF_FN_CALL);
2267 }
2268 
2269 static void
2270 pmflock_debug(device_t dev, const char *func, int line)
2271 {
2272 	device_lock_t dvl = device_getlock(dev);
2273 
2274 	aprint_debug_dev(dev, "%s.%d, %s dvl_nlock %d dvl_nwait %d dv_flags %x\n",
2275 	    func, line, curlwp_name(), dvl->dvl_nlock, dvl->dvl_nwait,
2276 	    dev->dv_flags);
2277 }
2278 
2279 static void
2280 pmflock_debug_with_flags(device_t dev, const char *func, int line PMF_FN_ARGS)
2281 {
2282 	device_lock_t dvl = device_getlock(dev);
2283 
2284 	aprint_debug_dev(dev, "%s.%d, %s dvl_nlock %d dvl_nwait %d dv_flags %x "
2285 	    "flags " PMF_FLAGS_FMT "\n", func, line, curlwp_name(),
2286 	    dvl->dvl_nlock, dvl->dvl_nwait, dev->dv_flags PMF_FN_CALL);
2287 }
2288 
2289 static bool
2290 device_pmf_lock1(device_t dev PMF_FN_ARGS)
2291 {
2292 	device_lock_t dvl = device_getlock(dev);
2293 
2294 	while (device_pmf_is_registered(dev) &&
2295 	    dvl->dvl_nlock > 0 && dvl->dvl_holder != curlwp) {
2296 		dvl->dvl_nwait++;
2297 		pmflock_debug_with_flags(dev, __func__, __LINE__ PMF_FN_CALL);
2298 		cv_wait(&dvl->dvl_cv, &dvl->dvl_mtx);
2299 		pmflock_debug_with_flags(dev, __func__, __LINE__ PMF_FN_CALL);
2300 		dvl->dvl_nwait--;
2301 	}
2302 	if (!device_pmf_is_registered(dev)) {
2303 		pmflock_debug_with_flags(dev, __func__, __LINE__ PMF_FN_CALL);
2304 		/* We could not acquire the lock, but some other thread may
2305 		 * wait for it, also.  Wake that thread.
2306 		 */
2307 		cv_signal(&dvl->dvl_cv);
2308 		return false;
2309 	}
2310 	dvl->dvl_nlock++;
2311 	dvl->dvl_holder = curlwp;
2312 	pmflock_debug_with_flags(dev, __func__, __LINE__ PMF_FN_CALL);
2313 	return true;
2314 }
2315 
2316 bool
2317 device_pmf_lock(device_t dev PMF_FN_ARGS)
2318 {
2319 	bool rc;
2320 	device_lock_t dvl = device_getlock(dev);
2321 
2322 	mutex_enter(&dvl->dvl_mtx);
2323 	rc = device_pmf_lock1(dev PMF_FN_CALL);
2324 	mutex_exit(&dvl->dvl_mtx);
2325 
2326 	return rc;
2327 }
2328 
2329 void
2330 device_pmf_unlock(device_t dev PMF_FN_ARGS)
2331 {
2332 	device_lock_t dvl = device_getlock(dev);
2333 
2334 	KASSERT(dvl->dvl_nlock > 0);
2335 	mutex_enter(&dvl->dvl_mtx);
2336 	if (--dvl->dvl_nlock == 0)
2337 		dvl->dvl_holder = NULL;
2338 	cv_signal(&dvl->dvl_cv);
2339 	pmflock_debug_with_flags(dev, __func__, __LINE__ PMF_FN_CALL);
2340 	mutex_exit(&dvl->dvl_mtx);
2341 }
2342 
2343 device_lock_t
2344 device_getlock(device_t dev)
2345 {
2346 	return &dev->dv_lock;
2347 }
2348 
2349 void *
2350 device_pmf_bus_private(device_t dev)
2351 {
2352 	return dev->dv_bus_private;
2353 }
2354 
2355 bool
2356 device_pmf_bus_suspend(device_t dev PMF_FN_ARGS)
2357 {
2358 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) != 0)
2359 		return true;
2360 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) == 0 ||
2361 	    (dev->dv_flags & DVF_DRIVER_SUSPENDED) == 0)
2362 		return false;
2363 	if (*dev->dv_bus_suspend != NULL &&
2364 	    !(*dev->dv_bus_suspend)(dev PMF_FN_CALL))
2365 		return false;
2366 
2367 	dev->dv_flags |= DVF_BUS_SUSPENDED;
2368 	return true;
2369 }
2370 
2371 bool
2372 device_pmf_bus_resume(device_t dev PMF_FN_ARGS)
2373 {
2374 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) == 0)
2375 		return true;
2376 	if ((flags & PMF_F_SELF) != 0 && !device_is_self_suspended(dev))
2377 		return false;
2378 	if (*dev->dv_bus_resume != NULL &&
2379 	    !(*dev->dv_bus_resume)(dev PMF_FN_CALL))
2380 		return false;
2381 
2382 	dev->dv_flags &= ~DVF_BUS_SUSPENDED;
2383 	return true;
2384 }
2385 
2386 bool
2387 device_pmf_bus_shutdown(device_t dev, int how)
2388 {
2389 
2390 	if (*dev->dv_bus_shutdown != NULL &&
2391 	    !(*dev->dv_bus_shutdown)(dev, how))
2392 		return false;
2393 	return true;
2394 }
2395 
2396 void
2397 device_pmf_bus_register(device_t dev, void *priv,
2398     bool (*suspend)(device_t PMF_FN_PROTO),
2399     bool (*resume)(device_t PMF_FN_PROTO),
2400     bool (*shutdown)(device_t, int), void (*deregister)(device_t))
2401 {
2402 	dev->dv_bus_private = priv;
2403 	dev->dv_bus_resume = resume;
2404 	dev->dv_bus_suspend = suspend;
2405 	dev->dv_bus_shutdown = shutdown;
2406 	dev->dv_bus_deregister = deregister;
2407 }
2408 
2409 void
2410 device_pmf_bus_deregister(device_t dev)
2411 {
2412 	if (dev->dv_bus_deregister == NULL)
2413 		return;
2414 	(*dev->dv_bus_deregister)(dev);
2415 	dev->dv_bus_private = NULL;
2416 	dev->dv_bus_suspend = NULL;
2417 	dev->dv_bus_resume = NULL;
2418 	dev->dv_bus_deregister = NULL;
2419 }
2420 
2421 void *
2422 device_pmf_class_private(device_t dev)
2423 {
2424 	return dev->dv_class_private;
2425 }
2426 
2427 bool
2428 device_pmf_class_suspend(device_t dev PMF_FN_ARGS)
2429 {
2430 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) != 0)
2431 		return true;
2432 	if (*dev->dv_class_suspend != NULL &&
2433 	    !(*dev->dv_class_suspend)(dev PMF_FN_CALL))
2434 		return false;
2435 
2436 	dev->dv_flags |= DVF_CLASS_SUSPENDED;
2437 	return true;
2438 }
2439 
2440 bool
2441 device_pmf_class_resume(device_t dev PMF_FN_ARGS)
2442 {
2443 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) == 0)
2444 		return true;
2445 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) != 0 ||
2446 	    (dev->dv_flags & DVF_DRIVER_SUSPENDED) != 0)
2447 		return false;
2448 	if (*dev->dv_class_resume != NULL &&
2449 	    !(*dev->dv_class_resume)(dev PMF_FN_CALL))
2450 		return false;
2451 
2452 	dev->dv_flags &= ~DVF_CLASS_SUSPENDED;
2453 	return true;
2454 }
2455 
2456 void
2457 device_pmf_class_register(device_t dev, void *priv,
2458     bool (*suspend)(device_t PMF_FN_PROTO),
2459     bool (*resume)(device_t PMF_FN_PROTO),
2460     void (*deregister)(device_t))
2461 {
2462 	dev->dv_class_private = priv;
2463 	dev->dv_class_suspend = suspend;
2464 	dev->dv_class_resume = resume;
2465 	dev->dv_class_deregister = deregister;
2466 }
2467 
2468 void
2469 device_pmf_class_deregister(device_t dev)
2470 {
2471 	if (dev->dv_class_deregister == NULL)
2472 		return;
2473 	(*dev->dv_class_deregister)(dev);
2474 	dev->dv_class_private = NULL;
2475 	dev->dv_class_suspend = NULL;
2476 	dev->dv_class_resume = NULL;
2477 	dev->dv_class_deregister = NULL;
2478 }
2479 
2480 bool
2481 device_active(device_t dev, devactive_t type)
2482 {
2483 	size_t i;
2484 
2485 	if (dev->dv_activity_count == 0)
2486 		return false;
2487 
2488 	for (i = 0; i < dev->dv_activity_count; ++i) {
2489 		if (dev->dv_activity_handlers[i] == NULL)
2490 			break;
2491 		(*dev->dv_activity_handlers[i])(dev, type);
2492 	}
2493 
2494 	return true;
2495 }
2496 
2497 bool
2498 device_active_register(device_t dev, void (*handler)(device_t, devactive_t))
2499 {
2500 	void (**new_handlers)(device_t, devactive_t);
2501 	void (**old_handlers)(device_t, devactive_t);
2502 	size_t i, old_size, new_size;
2503 	int s;
2504 
2505 	old_handlers = dev->dv_activity_handlers;
2506 	old_size = dev->dv_activity_count;
2507 
2508 	for (i = 0; i < old_size; ++i) {
2509 		KASSERT(old_handlers[i] != handler);
2510 		if (old_handlers[i] == NULL) {
2511 			old_handlers[i] = handler;
2512 			return true;
2513 		}
2514 	}
2515 
2516 	new_size = old_size + 4;
2517 	new_handlers = kmem_alloc(sizeof(void *[new_size]), KM_SLEEP);
2518 
2519 	memcpy(new_handlers, old_handlers, sizeof(void *[old_size]));
2520 	new_handlers[old_size] = handler;
2521 	memset(new_handlers + old_size + 1, 0,
2522 	    sizeof(int [new_size - (old_size+1)]));
2523 
2524 	s = splhigh();
2525 	dev->dv_activity_count = new_size;
2526 	dev->dv_activity_handlers = new_handlers;
2527 	splx(s);
2528 
2529 	if (old_handlers != NULL)
2530 		kmem_free(old_handlers, sizeof(void * [old_size]));
2531 
2532 	return true;
2533 }
2534 
2535 void
2536 device_active_deregister(device_t dev, void (*handler)(device_t, devactive_t))
2537 {
2538 	void (**old_handlers)(device_t, devactive_t);
2539 	size_t i, old_size;
2540 	int s;
2541 
2542 	old_handlers = dev->dv_activity_handlers;
2543 	old_size = dev->dv_activity_count;
2544 
2545 	for (i = 0; i < old_size; ++i) {
2546 		if (old_handlers[i] == handler)
2547 			break;
2548 		if (old_handlers[i] == NULL)
2549 			return; /* XXX panic? */
2550 	}
2551 
2552 	if (i == old_size)
2553 		return; /* XXX panic? */
2554 
2555 	for (; i < old_size - 1; ++i) {
2556 		if ((old_handlers[i] = old_handlers[i + 1]) != NULL)
2557 			continue;
2558 
2559 		if (i == 0) {
2560 			s = splhigh();
2561 			dev->dv_activity_count = 0;
2562 			dev->dv_activity_handlers = NULL;
2563 			splx(s);
2564 			kmem_free(old_handlers, sizeof(void *[old_size]));
2565 		}
2566 		return;
2567 	}
2568 	old_handlers[i] = NULL;
2569 }
2570 
2571 /*
2572  * Device Iteration
2573  *
2574  * deviter_t: a device iterator.  Holds state for a "walk" visiting
2575  *     each device_t's in the device tree.
2576  *
2577  * deviter_init(di, flags): initialize the device iterator `di'
2578  *     to "walk" the device tree.  deviter_next(di) will return
2579  *     the first device_t in the device tree, or NULL if there are
2580  *     no devices.
2581  *
2582  *     `flags' is one or more of DEVITER_F_RW, indicating that the
2583  *     caller intends to modify the device tree by calling
2584  *     config_detach(9) on devices in the order that the iterator
2585  *     returns them; DEVITER_F_ROOT_FIRST, asking for the devices
2586  *     nearest the "root" of the device tree to be returned, first;
2587  *     DEVITER_F_LEAVES_FIRST, asking for the devices furthest from
2588  *     the root of the device tree, first; and DEVITER_F_SHUTDOWN,
2589  *     indicating both that deviter_init() should not respect any
2590  *     locks on the device tree, and that deviter_next(di) may run
2591  *     in more than one LWP before the walk has finished.
2592  *
2593  *     Only one DEVITER_F_RW iterator may be in the device tree at
2594  *     once.
2595  *
2596  *     DEVITER_F_SHUTDOWN implies DEVITER_F_RW.
2597  *
2598  *     Results are undefined if the flags DEVITER_F_ROOT_FIRST and
2599  *     DEVITER_F_LEAVES_FIRST are used in combination.
2600  *
2601  * deviter_first(di, flags): initialize the device iterator `di'
2602  *     and return the first device_t in the device tree, or NULL
2603  *     if there are no devices.  The statement
2604  *
2605  *         dv = deviter_first(di);
2606  *
2607  *     is shorthand for
2608  *
2609  *         deviter_init(di);
2610  *         dv = deviter_next(di);
2611  *
2612  * deviter_next(di): return the next device_t in the device tree,
2613  *     or NULL if there are no more devices.  deviter_next(di)
2614  *     is undefined if `di' was not initialized with deviter_init() or
2615  *     deviter_first().
2616  *
2617  * deviter_release(di): stops iteration (subsequent calls to
2618  *     deviter_next() will return NULL), releases any locks and
2619  *     resources held by the device iterator.
2620  *
2621  * Device iteration does not return device_t's in any particular
2622  * order.  An iterator will never return the same device_t twice.
2623  * Device iteration is guaranteed to complete---i.e., if deviter_next(di)
2624  * is called repeatedly on the same `di', it will eventually return
2625  * NULL.  It is ok to attach/detach devices during device iteration.
2626  */
2627 void
2628 deviter_init(deviter_t *di, deviter_flags_t flags)
2629 {
2630 	device_t dv;
2631 	bool rw;
2632 
2633 	mutex_enter(&alldevs_mtx);
2634 	if ((flags & DEVITER_F_SHUTDOWN) != 0) {
2635 		flags |= DEVITER_F_RW;
2636 		alldevs_nwrite++;
2637 		alldevs_writer = NULL;
2638 		alldevs_nread = 0;
2639 	} else {
2640 		rw = (flags & DEVITER_F_RW) != 0;
2641 
2642 		if (alldevs_nwrite > 0 && alldevs_writer == NULL)
2643 			;
2644 		else while ((alldevs_nwrite != 0 && alldevs_writer != curlwp) ||
2645 		       (rw && alldevs_nread != 0))
2646 			cv_wait(&alldevs_cv, &alldevs_mtx);
2647 
2648 		if (rw) {
2649 			if (alldevs_nwrite++ == 0)
2650 				alldevs_writer = curlwp;
2651 		} else
2652 			alldevs_nread++;
2653 	}
2654 	mutex_exit(&alldevs_mtx);
2655 
2656 	memset(di, 0, sizeof(*di));
2657 
2658 	di->di_flags = flags;
2659 
2660 	switch (di->di_flags & (DEVITER_F_LEAVES_FIRST|DEVITER_F_ROOT_FIRST)) {
2661 	case DEVITER_F_LEAVES_FIRST:
2662 		TAILQ_FOREACH(dv, &alldevs, dv_list)
2663 			di->di_curdepth = MAX(di->di_curdepth, dv->dv_depth);
2664 		break;
2665 	case DEVITER_F_ROOT_FIRST:
2666 		TAILQ_FOREACH(dv, &alldevs, dv_list)
2667 			di->di_maxdepth = MAX(di->di_maxdepth, dv->dv_depth);
2668 		break;
2669 	default:
2670 		break;
2671 	}
2672 
2673 	deviter_reinit(di);
2674 }
2675 
2676 static void
2677 deviter_reinit(deviter_t *di)
2678 {
2679 	if ((di->di_flags & DEVITER_F_RW) != 0)
2680 		di->di_prev = TAILQ_LAST(&alldevs, devicelist);
2681 	else
2682 		di->di_prev = TAILQ_FIRST(&alldevs);
2683 }
2684 
2685 device_t
2686 deviter_first(deviter_t *di, deviter_flags_t flags)
2687 {
2688 	deviter_init(di, flags);
2689 	return deviter_next(di);
2690 }
2691 
2692 static device_t
2693 deviter_next1(deviter_t *di)
2694 {
2695 	device_t dv;
2696 
2697 	dv = di->di_prev;
2698 
2699 	if (dv == NULL)
2700 		;
2701 	else if ((di->di_flags & DEVITER_F_RW) != 0)
2702 		di->di_prev = TAILQ_PREV(dv, devicelist, dv_list);
2703 	else
2704 		di->di_prev = TAILQ_NEXT(dv, dv_list);
2705 
2706 	return dv;
2707 }
2708 
2709 device_t
2710 deviter_next(deviter_t *di)
2711 {
2712 	device_t dv = NULL;
2713 
2714 	switch (di->di_flags & (DEVITER_F_LEAVES_FIRST|DEVITER_F_ROOT_FIRST)) {
2715 	case 0:
2716 		return deviter_next1(di);
2717 	case DEVITER_F_LEAVES_FIRST:
2718 		while (di->di_curdepth >= 0) {
2719 			if ((dv = deviter_next1(di)) == NULL) {
2720 				di->di_curdepth--;
2721 				deviter_reinit(di);
2722 			} else if (dv->dv_depth == di->di_curdepth)
2723 				break;
2724 		}
2725 		return dv;
2726 	case DEVITER_F_ROOT_FIRST:
2727 		while (di->di_curdepth <= di->di_maxdepth) {
2728 			if ((dv = deviter_next1(di)) == NULL) {
2729 				di->di_curdepth++;
2730 				deviter_reinit(di);
2731 			} else if (dv->dv_depth == di->di_curdepth)
2732 				break;
2733 		}
2734 		return dv;
2735 	default:
2736 		return NULL;
2737 	}
2738 }
2739 
2740 void
2741 deviter_release(deviter_t *di)
2742 {
2743 	bool rw = (di->di_flags & DEVITER_F_RW) != 0;
2744 
2745 	mutex_enter(&alldevs_mtx);
2746 	if (!rw) {
2747 		--alldevs_nread;
2748 		cv_signal(&alldevs_cv);
2749 	} else if (alldevs_nwrite > 0 && alldevs_writer == NULL) {
2750 		--alldevs_nwrite;	/* shutting down: do not signal */
2751 	} else {
2752 		KASSERT(alldevs_nwrite != 0);
2753 		if (--alldevs_nwrite == 0)
2754 			alldevs_writer = NULL;
2755 		cv_signal(&alldevs_cv);
2756 	}
2757 	mutex_exit(&alldevs_mtx);
2758 }
2759 
2760 SYSCTL_SETUP(sysctl_detach_setup, "sysctl detach setup")
2761 {
2762 	const struct sysctlnode *node = NULL;
2763 
2764 	sysctl_createv(clog, 0, NULL, &node,
2765 		CTLFLAG_PERMANENT,
2766 		CTLTYPE_NODE, "kern", NULL,
2767 		NULL, 0, NULL, 0,
2768 		CTL_KERN, CTL_EOL);
2769 
2770 	if (node == NULL)
2771 		return;
2772 
2773 	sysctl_createv(clog, 0, &node, NULL,
2774 		CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
2775 		CTLTYPE_INT, "detachall",
2776 		SYSCTL_DESCR("Detach all devices at shutdown"),
2777 		NULL, 0, &detachall, 0,
2778 		CTL_CREATE, CTL_EOL);
2779 }
2780