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subr_autoconf.c revision 1.286
      1 /* $NetBSD: subr_autoconf.c,v 1.286 2021/06/13 00:11:46 riastradh Exp $ */
      2 
      3 /*
      4  * Copyright (c) 1996, 2000 Christopher G. Demetriou
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *          This product includes software developed for the
     18  *          NetBSD Project.  See http://www.NetBSD.org/ for
     19  *          information about NetBSD.
     20  * 4. The name of the author may not be used to endorse or promote products
     21  *    derived from this software without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     26  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     27  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     28  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     29  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     30  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     32  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     33  *
     34  * --(license Id: LICENSE.proto,v 1.1 2000/06/13 21:40:26 cgd Exp )--
     35  */
     36 
     37 /*
     38  * Copyright (c) 1992, 1993
     39  *	The Regents of the University of California.  All rights reserved.
     40  *
     41  * This software was developed by the Computer Systems Engineering group
     42  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
     43  * contributed to Berkeley.
     44  *
     45  * All advertising materials mentioning features or use of this software
     46  * must display the following acknowledgement:
     47  *	This product includes software developed by the University of
     48  *	California, Lawrence Berkeley Laboratories.
     49  *
     50  * Redistribution and use in source and binary forms, with or without
     51  * modification, are permitted provided that the following conditions
     52  * are met:
     53  * 1. Redistributions of source code must retain the above copyright
     54  *    notice, this list of conditions and the following disclaimer.
     55  * 2. Redistributions in binary form must reproduce the above copyright
     56  *    notice, this list of conditions and the following disclaimer in the
     57  *    documentation and/or other materials provided with the distribution.
     58  * 3. Neither the name of the University nor the names of its contributors
     59  *    may be used to endorse or promote products derived from this software
     60  *    without specific prior written permission.
     61  *
     62  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     63  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     64  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     65  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     66  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     67  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     68  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     69  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     70  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     71  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     72  * SUCH DAMAGE.
     73  *
     74  * from: Header: subr_autoconf.c,v 1.12 93/02/01 19:31:48 torek Exp  (LBL)
     75  *
     76  *	@(#)subr_autoconf.c	8.3 (Berkeley) 5/17/94
     77  */
     78 
     79 #define	__SUBR_AUTOCONF_PRIVATE	/* see <sys/device.h> */
     80 
     81 #include <sys/cdefs.h>
     82 __KERNEL_RCSID(0, "$NetBSD: subr_autoconf.c,v 1.286 2021/06/13 00:11:46 riastradh Exp $");
     83 
     84 #ifdef _KERNEL_OPT
     85 #include "opt_ddb.h"
     86 #include "drvctl.h"
     87 #endif
     88 
     89 #include <sys/param.h>
     90 #include <sys/device.h>
     91 #include <sys/disklabel.h>
     92 #include <sys/conf.h>
     93 #include <sys/kauth.h>
     94 #include <sys/kmem.h>
     95 #include <sys/systm.h>
     96 #include <sys/kernel.h>
     97 #include <sys/errno.h>
     98 #include <sys/proc.h>
     99 #include <sys/reboot.h>
    100 #include <sys/kthread.h>
    101 #include <sys/buf.h>
    102 #include <sys/dirent.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 #include <sys/stdarg.h>
    113 
    114 #include <sys/disk.h>
    115 
    116 #include <sys/rndsource.h>
    117 
    118 #include <machine/limits.h>
    119 
    120 /*
    121  * Autoconfiguration subroutines.
    122  */
    123 
    124 /*
    125  * Device autoconfiguration timings are mixed into the entropy pool.
    126  */
    127 static krndsource_t rnd_autoconf_source;
    128 
    129 /*
    130  * ioconf.c exports exactly two names: cfdata and cfroots.  All system
    131  * devices and drivers are found via these tables.
    132  */
    133 extern struct cfdata cfdata[];
    134 extern const short cfroots[];
    135 
    136 /*
    137  * List of all cfdriver structures.  We use this to detect duplicates
    138  * when other cfdrivers are loaded.
    139  */
    140 struct cfdriverlist allcfdrivers = LIST_HEAD_INITIALIZER(&allcfdrivers);
    141 extern struct cfdriver * const cfdriver_list_initial[];
    142 
    143 /*
    144  * Initial list of cfattach's.
    145  */
    146 extern const struct cfattachinit cfattachinit[];
    147 
    148 /*
    149  * List of cfdata tables.  We always have one such list -- the one
    150  * built statically when the kernel was configured.
    151  */
    152 struct cftablelist allcftables = TAILQ_HEAD_INITIALIZER(allcftables);
    153 static struct cftable initcftable;
    154 
    155 #define	ROOT ((device_t)NULL)
    156 
    157 struct matchinfo {
    158 	cfsubmatch_t fn;
    159 	device_t parent;
    160 	const int *locs;
    161 	void	*aux;
    162 	struct	cfdata *match;
    163 	int	pri;
    164 };
    165 
    166 struct alldevs_foray {
    167 	int			af_s;
    168 	struct devicelist	af_garbage;
    169 };
    170 
    171 static char *number(char *, int);
    172 static void mapply(struct matchinfo *, cfdata_t);
    173 static void config_devdelete(device_t);
    174 static void config_devunlink(device_t, struct devicelist *);
    175 static void config_makeroom(int, struct cfdriver *);
    176 static void config_devlink(device_t);
    177 static void config_alldevs_enter(struct alldevs_foray *);
    178 static void config_alldevs_exit(struct alldevs_foray *);
    179 static void config_add_attrib_dict(device_t);
    180 
    181 static void config_collect_garbage(struct devicelist *);
    182 static void config_dump_garbage(struct devicelist *);
    183 
    184 static void pmflock_debug(device_t, const char *, int);
    185 
    186 static device_t deviter_next1(deviter_t *);
    187 static void deviter_reinit(deviter_t *);
    188 
    189 struct deferred_config {
    190 	TAILQ_ENTRY(deferred_config) dc_queue;
    191 	device_t dc_dev;
    192 	void (*dc_func)(device_t);
    193 };
    194 
    195 TAILQ_HEAD(deferred_config_head, deferred_config);
    196 
    197 static struct deferred_config_head deferred_config_queue =
    198 	TAILQ_HEAD_INITIALIZER(deferred_config_queue);
    199 static struct deferred_config_head interrupt_config_queue =
    200 	TAILQ_HEAD_INITIALIZER(interrupt_config_queue);
    201 static int interrupt_config_threads = 8;
    202 static struct deferred_config_head mountroot_config_queue =
    203 	TAILQ_HEAD_INITIALIZER(mountroot_config_queue);
    204 static int mountroot_config_threads = 2;
    205 static lwp_t **mountroot_config_lwpids;
    206 static size_t mountroot_config_lwpids_size;
    207 bool root_is_mounted = false;
    208 
    209 static void config_process_deferred(struct deferred_config_head *, device_t);
    210 
    211 /* Hooks to finalize configuration once all real devices have been found. */
    212 struct finalize_hook {
    213 	TAILQ_ENTRY(finalize_hook) f_list;
    214 	int (*f_func)(device_t);
    215 	device_t f_dev;
    216 };
    217 static TAILQ_HEAD(, finalize_hook) config_finalize_list =
    218 	TAILQ_HEAD_INITIALIZER(config_finalize_list);
    219 static int config_finalize_done;
    220 
    221 /* list of all devices */
    222 static struct devicelist alldevs = TAILQ_HEAD_INITIALIZER(alldevs);
    223 static kmutex_t alldevs_lock __cacheline_aligned;
    224 static devgen_t alldevs_gen = 1;
    225 static int alldevs_nread = 0;
    226 static int alldevs_nwrite = 0;
    227 static bool alldevs_garbage = false;
    228 
    229 static struct devicelist config_pending =
    230     TAILQ_HEAD_INITIALIZER(config_pending);
    231 static kmutex_t config_misc_lock;
    232 static kcondvar_t config_misc_cv;
    233 
    234 static bool detachall = false;
    235 
    236 #define	STREQ(s1, s2)			\
    237 	(*(s1) == *(s2) && strcmp((s1), (s2)) == 0)
    238 
    239 static bool config_initialized = false;	/* config_init() has been called. */
    240 
    241 static int config_do_twiddle;
    242 static callout_t config_twiddle_ch;
    243 
    244 static void sysctl_detach_setup(struct sysctllog **);
    245 
    246 int no_devmon_insert(const char *, prop_dictionary_t);
    247 int (*devmon_insert_vec)(const char *, prop_dictionary_t) = no_devmon_insert;
    248 
    249 typedef int (*cfdriver_fn)(struct cfdriver *);
    250 static int
    251 frob_cfdrivervec(struct cfdriver * const *cfdriverv,
    252 	cfdriver_fn drv_do, cfdriver_fn drv_undo,
    253 	const char *style, bool dopanic)
    254 {
    255 	void (*pr)(const char *, ...) __printflike(1, 2) =
    256 	    dopanic ? panic : printf;
    257 	int i, error = 0, e2 __diagused;
    258 
    259 	for (i = 0; cfdriverv[i] != NULL; i++) {
    260 		if ((error = drv_do(cfdriverv[i])) != 0) {
    261 			pr("configure: `%s' driver %s failed: %d",
    262 			    cfdriverv[i]->cd_name, style, error);
    263 			goto bad;
    264 		}
    265 	}
    266 
    267 	KASSERT(error == 0);
    268 	return 0;
    269 
    270  bad:
    271 	printf("\n");
    272 	for (i--; i >= 0; i--) {
    273 		e2 = drv_undo(cfdriverv[i]);
    274 		KASSERT(e2 == 0);
    275 	}
    276 
    277 	return error;
    278 }
    279 
    280 typedef int (*cfattach_fn)(const char *, struct cfattach *);
    281 static int
    282 frob_cfattachvec(const struct cfattachinit *cfattachv,
    283 	cfattach_fn att_do, cfattach_fn att_undo,
    284 	const char *style, bool dopanic)
    285 {
    286 	const struct cfattachinit *cfai = NULL;
    287 	void (*pr)(const char *, ...) __printflike(1, 2) =
    288 	    dopanic ? panic : printf;
    289 	int j = 0, error = 0, e2 __diagused;
    290 
    291 	for (cfai = &cfattachv[0]; cfai->cfai_name != NULL; cfai++) {
    292 		for (j = 0; cfai->cfai_list[j] != NULL; j++) {
    293 			if ((error = att_do(cfai->cfai_name,
    294 			    cfai->cfai_list[j])) != 0) {
    295 				pr("configure: attachment `%s' "
    296 				    "of `%s' driver %s failed: %d",
    297 				    cfai->cfai_list[j]->ca_name,
    298 				    cfai->cfai_name, style, error);
    299 				goto bad;
    300 			}
    301 		}
    302 	}
    303 
    304 	KASSERT(error == 0);
    305 	return 0;
    306 
    307  bad:
    308 	/*
    309 	 * Rollback in reverse order.  dunno if super-important, but
    310 	 * do that anyway.  Although the code looks a little like
    311 	 * someone did a little integration (in the math sense).
    312 	 */
    313 	printf("\n");
    314 	if (cfai) {
    315 		bool last;
    316 
    317 		for (last = false; last == false; ) {
    318 			if (cfai == &cfattachv[0])
    319 				last = true;
    320 			for (j--; j >= 0; j--) {
    321 				e2 = att_undo(cfai->cfai_name,
    322 				    cfai->cfai_list[j]);
    323 				KASSERT(e2 == 0);
    324 			}
    325 			if (!last) {
    326 				cfai--;
    327 				for (j = 0; cfai->cfai_list[j] != NULL; j++)
    328 					;
    329 			}
    330 		}
    331 	}
    332 
    333 	return error;
    334 }
    335 
    336 /*
    337  * Initialize the autoconfiguration data structures.  Normally this
    338  * is done by configure(), but some platforms need to do this very
    339  * early (to e.g. initialize the console).
    340  */
    341 void
    342 config_init(void)
    343 {
    344 
    345 	KASSERT(config_initialized == false);
    346 
    347 	mutex_init(&alldevs_lock, MUTEX_DEFAULT, IPL_VM);
    348 
    349 	mutex_init(&config_misc_lock, MUTEX_DEFAULT, IPL_NONE);
    350 	cv_init(&config_misc_cv, "cfgmisc");
    351 
    352 	callout_init(&config_twiddle_ch, CALLOUT_MPSAFE);
    353 
    354 	frob_cfdrivervec(cfdriver_list_initial,
    355 	    config_cfdriver_attach, NULL, "bootstrap", true);
    356 	frob_cfattachvec(cfattachinit,
    357 	    config_cfattach_attach, NULL, "bootstrap", true);
    358 
    359 	initcftable.ct_cfdata = cfdata;
    360 	TAILQ_INSERT_TAIL(&allcftables, &initcftable, ct_list);
    361 
    362 	rnd_attach_source(&rnd_autoconf_source, "autoconf", RND_TYPE_UNKNOWN,
    363 	    RND_FLAG_COLLECT_TIME);
    364 
    365 	config_initialized = true;
    366 }
    367 
    368 /*
    369  * Init or fini drivers and attachments.  Either all or none
    370  * are processed (via rollback).  It would be nice if this were
    371  * atomic to outside consumers, but with the current state of
    372  * locking ...
    373  */
    374 int
    375 config_init_component(struct cfdriver * const *cfdriverv,
    376 	const struct cfattachinit *cfattachv, struct cfdata *cfdatav)
    377 {
    378 	int error;
    379 
    380 	KERNEL_LOCK(1, NULL);
    381 
    382 	if ((error = frob_cfdrivervec(cfdriverv,
    383 	    config_cfdriver_attach, config_cfdriver_detach, "init", false))!= 0)
    384 		goto out;
    385 	if ((error = frob_cfattachvec(cfattachv,
    386 	    config_cfattach_attach, config_cfattach_detach,
    387 	    "init", false)) != 0) {
    388 		frob_cfdrivervec(cfdriverv,
    389 	            config_cfdriver_detach, NULL, "init rollback", true);
    390 		goto out;
    391 	}
    392 	if ((error = config_cfdata_attach(cfdatav, 1)) != 0) {
    393 		frob_cfattachvec(cfattachv,
    394 		    config_cfattach_detach, NULL, "init rollback", true);
    395 		frob_cfdrivervec(cfdriverv,
    396 	            config_cfdriver_detach, NULL, "init rollback", true);
    397 		goto out;
    398 	}
    399 
    400 	/* Success!  */
    401 	error = 0;
    402 
    403 out:	KERNEL_UNLOCK_ONE(NULL);
    404 	return error;
    405 }
    406 
    407 int
    408 config_fini_component(struct cfdriver * const *cfdriverv,
    409 	const struct cfattachinit *cfattachv, struct cfdata *cfdatav)
    410 {
    411 	int error;
    412 
    413 	KERNEL_LOCK(1, NULL);
    414 
    415 	if ((error = config_cfdata_detach(cfdatav)) != 0)
    416 		goto out;
    417 	if ((error = frob_cfattachvec(cfattachv,
    418 	    config_cfattach_detach, config_cfattach_attach,
    419 	    "fini", false)) != 0) {
    420 		if (config_cfdata_attach(cfdatav, 0) != 0)
    421 			panic("config_cfdata fini rollback failed");
    422 		goto out;
    423 	}
    424 	if ((error = frob_cfdrivervec(cfdriverv,
    425 	    config_cfdriver_detach, config_cfdriver_attach,
    426 	    "fini", false)) != 0) {
    427 		frob_cfattachvec(cfattachv,
    428 	            config_cfattach_attach, NULL, "fini rollback", true);
    429 		if (config_cfdata_attach(cfdatav, 0) != 0)
    430 			panic("config_cfdata fini rollback failed");
    431 		goto out;
    432 	}
    433 
    434 	/* Success!  */
    435 	error = 0;
    436 
    437 out:	KERNEL_UNLOCK_ONE(NULL);
    438 	return error;
    439 }
    440 
    441 void
    442 config_init_mi(void)
    443 {
    444 
    445 	if (!config_initialized)
    446 		config_init();
    447 
    448 	sysctl_detach_setup(NULL);
    449 }
    450 
    451 void
    452 config_deferred(device_t dev)
    453 {
    454 
    455 	KASSERT(KERNEL_LOCKED_P());
    456 
    457 	config_process_deferred(&deferred_config_queue, dev);
    458 	config_process_deferred(&interrupt_config_queue, dev);
    459 	config_process_deferred(&mountroot_config_queue, dev);
    460 }
    461 
    462 static void
    463 config_interrupts_thread(void *cookie)
    464 {
    465 	struct deferred_config *dc;
    466 	device_t dev;
    467 
    468 	mutex_enter(&config_misc_lock);
    469 	while ((dc = TAILQ_FIRST(&interrupt_config_queue)) != NULL) {
    470 		TAILQ_REMOVE(&interrupt_config_queue, dc, dc_queue);
    471 		mutex_exit(&config_misc_lock);
    472 
    473 		dev = dc->dc_dev;
    474 		(*dc->dc_func)(dev);
    475 		if (!device_pmf_is_registered(dev))
    476 			aprint_debug_dev(dev,
    477 			    "WARNING: power management not supported\n");
    478 		config_pending_decr(dev);
    479 		kmem_free(dc, sizeof(*dc));
    480 
    481 		mutex_enter(&config_misc_lock);
    482 	}
    483 	mutex_exit(&config_misc_lock);
    484 
    485 	kthread_exit(0);
    486 }
    487 
    488 void
    489 config_create_interruptthreads(void)
    490 {
    491 	int i;
    492 
    493 	for (i = 0; i < interrupt_config_threads; i++) {
    494 		(void)kthread_create(PRI_NONE, 0/*XXXSMP */, NULL,
    495 		    config_interrupts_thread, NULL, NULL, "configintr");
    496 	}
    497 }
    498 
    499 static void
    500 config_mountroot_thread(void *cookie)
    501 {
    502 	struct deferred_config *dc;
    503 
    504 	mutex_enter(&config_misc_lock);
    505 	while ((dc = TAILQ_FIRST(&mountroot_config_queue)) != NULL) {
    506 		TAILQ_REMOVE(&mountroot_config_queue, dc, dc_queue);
    507 		mutex_exit(&config_misc_lock);
    508 
    509 		(*dc->dc_func)(dc->dc_dev);
    510 		kmem_free(dc, sizeof(*dc));
    511 
    512 		mutex_enter(&config_misc_lock);
    513 	}
    514 	mutex_exit(&config_misc_lock);
    515 
    516 	kthread_exit(0);
    517 }
    518 
    519 void
    520 config_create_mountrootthreads(void)
    521 {
    522 	int i;
    523 
    524 	if (!root_is_mounted)
    525 		root_is_mounted = true;
    526 
    527 	mountroot_config_lwpids_size = sizeof(mountroot_config_lwpids) *
    528 				       mountroot_config_threads;
    529 	mountroot_config_lwpids = kmem_alloc(mountroot_config_lwpids_size,
    530 					     KM_NOSLEEP);
    531 	KASSERT(mountroot_config_lwpids);
    532 	for (i = 0; i < mountroot_config_threads; i++) {
    533 		mountroot_config_lwpids[i] = 0;
    534 		(void)kthread_create(PRI_NONE, KTHREAD_MUSTJOIN/* XXXSMP */,
    535 				     NULL, config_mountroot_thread, NULL,
    536 				     &mountroot_config_lwpids[i],
    537 				     "configroot");
    538 	}
    539 }
    540 
    541 void
    542 config_finalize_mountroot(void)
    543 {
    544 	int i, error;
    545 
    546 	for (i = 0; i < mountroot_config_threads; i++) {
    547 		if (mountroot_config_lwpids[i] == 0)
    548 			continue;
    549 
    550 		error = kthread_join(mountroot_config_lwpids[i]);
    551 		if (error)
    552 			printf("%s: thread %x joined with error %d\n",
    553 			       __func__, i, error);
    554 	}
    555 	kmem_free(mountroot_config_lwpids, mountroot_config_lwpids_size);
    556 }
    557 
    558 /*
    559  * Announce device attach/detach to userland listeners.
    560  */
    561 
    562 int
    563 no_devmon_insert(const char *name, prop_dictionary_t p)
    564 {
    565 
    566 	return ENODEV;
    567 }
    568 
    569 static void
    570 devmon_report_device(device_t dev, bool isattach)
    571 {
    572 	prop_dictionary_t ev, dict = device_properties(dev);
    573 	const char *parent;
    574 	const char *what;
    575 	const char *where;
    576 	device_t pdev = device_parent(dev);
    577 
    578 	/* If currently no drvctl device, just return */
    579 	if (devmon_insert_vec == no_devmon_insert)
    580 		return;
    581 
    582 	ev = prop_dictionary_create();
    583 	if (ev == NULL)
    584 		return;
    585 
    586 	what = (isattach ? "device-attach" : "device-detach");
    587 	parent = (pdev == NULL ? "root" : device_xname(pdev));
    588 	if (prop_dictionary_get_string(dict, "location", &where)) {
    589 		prop_dictionary_set_string(ev, "location", where);
    590 		aprint_debug("ev: %s %s at %s in [%s]\n",
    591 		    what, device_xname(dev), parent, where);
    592 	}
    593 	if (!prop_dictionary_set_string(ev, "device", device_xname(dev)) ||
    594 	    !prop_dictionary_set_string(ev, "parent", parent)) {
    595 		prop_object_release(ev);
    596 		return;
    597 	}
    598 
    599 	if ((*devmon_insert_vec)(what, ev) != 0)
    600 		prop_object_release(ev);
    601 }
    602 
    603 /*
    604  * Add a cfdriver to the system.
    605  */
    606 int
    607 config_cfdriver_attach(struct cfdriver *cd)
    608 {
    609 	struct cfdriver *lcd;
    610 
    611 	/* Make sure this driver isn't already in the system. */
    612 	LIST_FOREACH(lcd, &allcfdrivers, cd_list) {
    613 		if (STREQ(lcd->cd_name, cd->cd_name))
    614 			return EEXIST;
    615 	}
    616 
    617 	LIST_INIT(&cd->cd_attach);
    618 	LIST_INSERT_HEAD(&allcfdrivers, cd, cd_list);
    619 
    620 	return 0;
    621 }
    622 
    623 /*
    624  * Remove a cfdriver from the system.
    625  */
    626 int
    627 config_cfdriver_detach(struct cfdriver *cd)
    628 {
    629 	struct alldevs_foray af;
    630 	int i, rc = 0;
    631 
    632 	config_alldevs_enter(&af);
    633 	/* Make sure there are no active instances. */
    634 	for (i = 0; i < cd->cd_ndevs; i++) {
    635 		if (cd->cd_devs[i] != NULL) {
    636 			rc = EBUSY;
    637 			break;
    638 		}
    639 	}
    640 	config_alldevs_exit(&af);
    641 
    642 	if (rc != 0)
    643 		return rc;
    644 
    645 	/* ...and no attachments loaded. */
    646 	if (LIST_EMPTY(&cd->cd_attach) == 0)
    647 		return EBUSY;
    648 
    649 	LIST_REMOVE(cd, cd_list);
    650 
    651 	KASSERT(cd->cd_devs == NULL);
    652 
    653 	return 0;
    654 }
    655 
    656 /*
    657  * Look up a cfdriver by name.
    658  */
    659 struct cfdriver *
    660 config_cfdriver_lookup(const char *name)
    661 {
    662 	struct cfdriver *cd;
    663 
    664 	LIST_FOREACH(cd, &allcfdrivers, cd_list) {
    665 		if (STREQ(cd->cd_name, name))
    666 			return cd;
    667 	}
    668 
    669 	return NULL;
    670 }
    671 
    672 /*
    673  * Add a cfattach to the specified driver.
    674  */
    675 int
    676 config_cfattach_attach(const char *driver, struct cfattach *ca)
    677 {
    678 	struct cfattach *lca;
    679 	struct cfdriver *cd;
    680 
    681 	cd = config_cfdriver_lookup(driver);
    682 	if (cd == NULL)
    683 		return ESRCH;
    684 
    685 	/* Make sure this attachment isn't already on this driver. */
    686 	LIST_FOREACH(lca, &cd->cd_attach, ca_list) {
    687 		if (STREQ(lca->ca_name, ca->ca_name))
    688 			return EEXIST;
    689 	}
    690 
    691 	LIST_INSERT_HEAD(&cd->cd_attach, ca, ca_list);
    692 
    693 	return 0;
    694 }
    695 
    696 /*
    697  * Remove a cfattach from the specified driver.
    698  */
    699 int
    700 config_cfattach_detach(const char *driver, struct cfattach *ca)
    701 {
    702 	struct alldevs_foray af;
    703 	struct cfdriver *cd;
    704 	device_t dev;
    705 	int i, rc = 0;
    706 
    707 	cd = config_cfdriver_lookup(driver);
    708 	if (cd == NULL)
    709 		return ESRCH;
    710 
    711 	config_alldevs_enter(&af);
    712 	/* Make sure there are no active instances. */
    713 	for (i = 0; i < cd->cd_ndevs; i++) {
    714 		if ((dev = cd->cd_devs[i]) == NULL)
    715 			continue;
    716 		if (dev->dv_cfattach == ca) {
    717 			rc = EBUSY;
    718 			break;
    719 		}
    720 	}
    721 	config_alldevs_exit(&af);
    722 
    723 	if (rc != 0)
    724 		return rc;
    725 
    726 	LIST_REMOVE(ca, ca_list);
    727 
    728 	return 0;
    729 }
    730 
    731 /*
    732  * Look up a cfattach by name.
    733  */
    734 static struct cfattach *
    735 config_cfattach_lookup_cd(struct cfdriver *cd, const char *atname)
    736 {
    737 	struct cfattach *ca;
    738 
    739 	LIST_FOREACH(ca, &cd->cd_attach, ca_list) {
    740 		if (STREQ(ca->ca_name, atname))
    741 			return ca;
    742 	}
    743 
    744 	return NULL;
    745 }
    746 
    747 /*
    748  * Look up a cfattach by driver/attachment name.
    749  */
    750 struct cfattach *
    751 config_cfattach_lookup(const char *name, const char *atname)
    752 {
    753 	struct cfdriver *cd;
    754 
    755 	cd = config_cfdriver_lookup(name);
    756 	if (cd == NULL)
    757 		return NULL;
    758 
    759 	return config_cfattach_lookup_cd(cd, atname);
    760 }
    761 
    762 /*
    763  * Apply the matching function and choose the best.  This is used
    764  * a few times and we want to keep the code small.
    765  */
    766 static void
    767 mapply(struct matchinfo *m, cfdata_t cf)
    768 {
    769 	int pri;
    770 
    771 	if (m->fn != NULL) {
    772 		pri = (*m->fn)(m->parent, cf, m->locs, m->aux);
    773 	} else {
    774 		pri = config_match(m->parent, cf, m->aux);
    775 	}
    776 	if (pri > m->pri) {
    777 		m->match = cf;
    778 		m->pri = pri;
    779 	}
    780 }
    781 
    782 int
    783 config_stdsubmatch(device_t parent, cfdata_t cf, const int *locs, void *aux)
    784 {
    785 	const struct cfiattrdata *ci;
    786 	const struct cflocdesc *cl;
    787 	int nlocs, i;
    788 
    789 	ci = cfiattr_lookup(cfdata_ifattr(cf), parent->dv_cfdriver);
    790 	KASSERT(ci);
    791 	nlocs = ci->ci_loclen;
    792 	KASSERT(!nlocs || locs);
    793 	for (i = 0; i < nlocs; i++) {
    794 		cl = &ci->ci_locdesc[i];
    795 		if (cl->cld_defaultstr != NULL &&
    796 		    cf->cf_loc[i] == cl->cld_default)
    797 			continue;
    798 		if (cf->cf_loc[i] == locs[i])
    799 			continue;
    800 		return 0;
    801 	}
    802 
    803 	return config_match(parent, cf, aux);
    804 }
    805 
    806 /*
    807  * Helper function: check whether the driver supports the interface attribute
    808  * and return its descriptor structure.
    809  */
    810 static const struct cfiattrdata *
    811 cfdriver_get_iattr(const struct cfdriver *cd, const char *ia)
    812 {
    813 	const struct cfiattrdata * const *cpp;
    814 
    815 	if (cd->cd_attrs == NULL)
    816 		return 0;
    817 
    818 	for (cpp = cd->cd_attrs; *cpp; cpp++) {
    819 		if (STREQ((*cpp)->ci_name, ia)) {
    820 			/* Match. */
    821 			return *cpp;
    822 		}
    823 	}
    824 	return 0;
    825 }
    826 
    827 #if defined(DIAGNOSTIC)
    828 static int
    829 cfdriver_iattr_count(const struct cfdriver *cd)
    830 {
    831 	const struct cfiattrdata * const *cpp;
    832 	int i;
    833 
    834 	if (cd->cd_attrs == NULL)
    835 		return 0;
    836 
    837 	for (i = 0, cpp = cd->cd_attrs; *cpp; cpp++) {
    838 		i++;
    839 	}
    840 	return i;
    841 }
    842 #endif /* DIAGNOSTIC */
    843 
    844 /*
    845  * Lookup an interface attribute description by name.
    846  * If the driver is given, consider only its supported attributes.
    847  */
    848 const struct cfiattrdata *
    849 cfiattr_lookup(const char *name, const struct cfdriver *cd)
    850 {
    851 	const struct cfdriver *d;
    852 	const struct cfiattrdata *ia;
    853 
    854 	if (cd)
    855 		return cfdriver_get_iattr(cd, name);
    856 
    857 	LIST_FOREACH(d, &allcfdrivers, cd_list) {
    858 		ia = cfdriver_get_iattr(d, name);
    859 		if (ia)
    860 			return ia;
    861 	}
    862 	return 0;
    863 }
    864 
    865 /*
    866  * Determine if `parent' is a potential parent for a device spec based
    867  * on `cfp'.
    868  */
    869 static int
    870 cfparent_match(const device_t parent, const struct cfparent *cfp)
    871 {
    872 	struct cfdriver *pcd;
    873 
    874 	/* We don't match root nodes here. */
    875 	if (cfp == NULL)
    876 		return 0;
    877 
    878 	pcd = parent->dv_cfdriver;
    879 	KASSERT(pcd != NULL);
    880 
    881 	/*
    882 	 * First, ensure this parent has the correct interface
    883 	 * attribute.
    884 	 */
    885 	if (!cfdriver_get_iattr(pcd, cfp->cfp_iattr))
    886 		return 0;
    887 
    888 	/*
    889 	 * If no specific parent device instance was specified (i.e.
    890 	 * we're attaching to the attribute only), we're done!
    891 	 */
    892 	if (cfp->cfp_parent == NULL)
    893 		return 1;
    894 
    895 	/*
    896 	 * Check the parent device's name.
    897 	 */
    898 	if (STREQ(pcd->cd_name, cfp->cfp_parent) == 0)
    899 		return 0;	/* not the same parent */
    900 
    901 	/*
    902 	 * Make sure the unit number matches.
    903 	 */
    904 	if (cfp->cfp_unit == DVUNIT_ANY ||	/* wildcard */
    905 	    cfp->cfp_unit == parent->dv_unit)
    906 		return 1;
    907 
    908 	/* Unit numbers don't match. */
    909 	return 0;
    910 }
    911 
    912 /*
    913  * Helper for config_cfdata_attach(): check all devices whether it could be
    914  * parent any attachment in the config data table passed, and rescan.
    915  */
    916 static void
    917 rescan_with_cfdata(const struct cfdata *cf)
    918 {
    919 	device_t d;
    920 	const struct cfdata *cf1;
    921 	deviter_t di;
    922 
    923 	KASSERT(KERNEL_LOCKED_P());
    924 
    925 	/*
    926 	 * "alldevs" is likely longer than a modules's cfdata, so make it
    927 	 * the outer loop.
    928 	 */
    929 	for (d = deviter_first(&di, 0); d != NULL; d = deviter_next(&di)) {
    930 
    931 		if (!(d->dv_cfattach->ca_rescan))
    932 			continue;
    933 
    934 		for (cf1 = cf; cf1->cf_name; cf1++) {
    935 
    936 			if (!cfparent_match(d, cf1->cf_pspec))
    937 				continue;
    938 
    939 			(*d->dv_cfattach->ca_rescan)(d,
    940 				cfdata_ifattr(cf1), cf1->cf_loc);
    941 
    942 			config_deferred(d);
    943 		}
    944 	}
    945 	deviter_release(&di);
    946 }
    947 
    948 /*
    949  * Attach a supplemental config data table and rescan potential
    950  * parent devices if required.
    951  */
    952 int
    953 config_cfdata_attach(cfdata_t cf, int scannow)
    954 {
    955 	struct cftable *ct;
    956 
    957 	KERNEL_LOCK(1, NULL);
    958 
    959 	ct = kmem_alloc(sizeof(*ct), KM_SLEEP);
    960 	ct->ct_cfdata = cf;
    961 	TAILQ_INSERT_TAIL(&allcftables, ct, ct_list);
    962 
    963 	if (scannow)
    964 		rescan_with_cfdata(cf);
    965 
    966 	KERNEL_UNLOCK_ONE();
    967 
    968 	return 0;
    969 }
    970 
    971 /*
    972  * Helper for config_cfdata_detach: check whether a device is
    973  * found through any attachment in the config data table.
    974  */
    975 static int
    976 dev_in_cfdata(device_t d, cfdata_t cf)
    977 {
    978 	const struct cfdata *cf1;
    979 
    980 	for (cf1 = cf; cf1->cf_name; cf1++)
    981 		if (d->dv_cfdata == cf1)
    982 			return 1;
    983 
    984 	return 0;
    985 }
    986 
    987 /*
    988  * Detach a supplemental config data table. Detach all devices found
    989  * through that table (and thus keeping references to it) before.
    990  */
    991 int
    992 config_cfdata_detach(cfdata_t cf)
    993 {
    994 	device_t d;
    995 	int error = 0;
    996 	struct cftable *ct;
    997 	deviter_t di;
    998 
    999 	KERNEL_LOCK(1, NULL);
   1000 
   1001 	for (d = deviter_first(&di, DEVITER_F_RW); d != NULL;
   1002 	     d = deviter_next(&di)) {
   1003 		if (!dev_in_cfdata(d, cf))
   1004 			continue;
   1005 		if ((error = config_detach(d, 0)) != 0)
   1006 			break;
   1007 	}
   1008 	deviter_release(&di);
   1009 	if (error) {
   1010 		aprint_error_dev(d, "unable to detach instance\n");
   1011 		goto out;
   1012 	}
   1013 
   1014 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
   1015 		if (ct->ct_cfdata == cf) {
   1016 			TAILQ_REMOVE(&allcftables, ct, ct_list);
   1017 			kmem_free(ct, sizeof(*ct));
   1018 			error = 0;
   1019 			goto out;
   1020 		}
   1021 	}
   1022 
   1023 	/* not found -- shouldn't happen */
   1024 	error = EINVAL;
   1025 
   1026 out:	KERNEL_UNLOCK_ONE(NULL);
   1027 	return error;
   1028 }
   1029 
   1030 /*
   1031  * Invoke the "match" routine for a cfdata entry on behalf of
   1032  * an external caller, usually a direct config "submatch" routine.
   1033  */
   1034 int
   1035 config_match(device_t parent, cfdata_t cf, void *aux)
   1036 {
   1037 	struct cfattach *ca;
   1038 
   1039 	KASSERT(KERNEL_LOCKED_P());
   1040 
   1041 	ca = config_cfattach_lookup(cf->cf_name, cf->cf_atname);
   1042 	if (ca == NULL) {
   1043 		/* No attachment for this entry, oh well. */
   1044 		return 0;
   1045 	}
   1046 
   1047 	return (*ca->ca_match)(parent, cf, aux);
   1048 }
   1049 
   1050 /*
   1051  * Invoke the "probe" routine for a cfdata entry on behalf of
   1052  * an external caller, usually an indirect config "search" routine.
   1053  */
   1054 int
   1055 config_probe(device_t parent, cfdata_t cf, void *aux)
   1056 {
   1057 	/*
   1058 	 * This is currently a synonym for config_match(), but this
   1059 	 * is an implementation detail; "match" and "probe" routines
   1060 	 * have different behaviors.
   1061 	 *
   1062 	 * XXX config_probe() should return a bool, because there is
   1063 	 * XXX no match score for probe -- it's either there or it's
   1064 	 * XXX not, but some ports abuse the return value as a way
   1065 	 * XXX to attach "critical" devices before "non-critical"
   1066 	 * XXX devices.
   1067 	 */
   1068 	return config_match(parent, cf, aux);
   1069 }
   1070 
   1071 static void
   1072 config_get_cfargs(cfarg_t tag,
   1073 		  cfsubmatch_t *fnp,		/* output */
   1074 		  const char **ifattrp,		/* output */
   1075 		  const int **locsp,		/* output */
   1076 		  devhandle_t *handlep,		/* output */
   1077 		  va_list ap)
   1078 {
   1079 	cfsubmatch_t fn = NULL;
   1080 	const char *ifattr = NULL;
   1081 	const int *locs = NULL;
   1082 	devhandle_t handle;
   1083 
   1084 	devhandle_invalidate(&handle);
   1085 
   1086 	while (tag != CFARG_EOL) {
   1087 		switch (tag) {
   1088 		/*
   1089 		 * CFARG_SUBMATCH and CFARG_SEARCH are synonyms, but this
   1090 		 * is merely an implementation detail.  They are distinct
   1091 		 * from the caller's point of view.
   1092 		 */
   1093 		case CFARG_SUBMATCH:
   1094 		case CFARG_SEARCH:
   1095 			/* Only allow one function to be specified. */
   1096 			if (fn != NULL) {
   1097 				panic("%s: caller specified both "
   1098 				    "SUBMATCH and SEARCH", __func__);
   1099 			}
   1100 			fn = va_arg(ap, cfsubmatch_t);
   1101 			break;
   1102 
   1103 		case CFARG_IATTR:
   1104 			ifattr = va_arg(ap, const char *);
   1105 			break;
   1106 
   1107 		case CFARG_LOCATORS:
   1108 			locs = va_arg(ap, const int *);
   1109 			break;
   1110 
   1111 		case CFARG_DEVHANDLE:
   1112 			handle = va_arg(ap, devhandle_t);
   1113 			break;
   1114 
   1115 		default:
   1116 			panic("%s: unknown cfarg tag: %d\n",
   1117 			    __func__, tag);
   1118 		}
   1119 		tag = va_arg(ap, cfarg_t);
   1120 	}
   1121 
   1122 	if (fnp != NULL)
   1123 		*fnp = fn;
   1124 	if (ifattrp != NULL)
   1125 		*ifattrp = ifattr;
   1126 	if (locsp != NULL)
   1127 		*locsp = locs;
   1128 	if (handlep != NULL)
   1129 		*handlep = handle;
   1130 }
   1131 
   1132 /*
   1133  * Iterate over all potential children of some device, calling the given
   1134  * function (default being the child's match function) for each one.
   1135  * Nonzero returns are matches; the highest value returned is considered
   1136  * the best match.  Return the `found child' if we got a match, or NULL
   1137  * otherwise.  The `aux' pointer is simply passed on through.
   1138  *
   1139  * Note that this function is designed so that it can be used to apply
   1140  * an arbitrary function to all potential children (its return value
   1141  * can be ignored).
   1142  */
   1143 cfdata_t
   1144 config_vsearch(device_t parent, void *aux, cfarg_t tag, va_list ap)
   1145 {
   1146 	cfsubmatch_t fn;
   1147 	const char *ifattr;
   1148 	const int *locs;
   1149 	struct cftable *ct;
   1150 	cfdata_t cf;
   1151 	struct matchinfo m;
   1152 
   1153 	config_get_cfargs(tag, &fn, &ifattr, &locs, NULL, ap);
   1154 
   1155 	KASSERT(config_initialized);
   1156 	KASSERT(!ifattr || cfdriver_get_iattr(parent->dv_cfdriver, ifattr));
   1157 	KASSERT(ifattr || cfdriver_iattr_count(parent->dv_cfdriver) < 2);
   1158 
   1159 	m.fn = fn;
   1160 	m.parent = parent;
   1161 	m.locs = locs;
   1162 	m.aux = aux;
   1163 	m.match = NULL;
   1164 	m.pri = 0;
   1165 
   1166 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
   1167 		for (cf = ct->ct_cfdata; cf->cf_name; cf++) {
   1168 
   1169 			/* We don't match root nodes here. */
   1170 			if (!cf->cf_pspec)
   1171 				continue;
   1172 
   1173 			/*
   1174 			 * Skip cf if no longer eligible, otherwise scan
   1175 			 * through parents for one matching `parent', and
   1176 			 * try match function.
   1177 			 */
   1178 			if (cf->cf_fstate == FSTATE_FOUND)
   1179 				continue;
   1180 			if (cf->cf_fstate == FSTATE_DNOTFOUND ||
   1181 			    cf->cf_fstate == FSTATE_DSTAR)
   1182 				continue;
   1183 
   1184 			/*
   1185 			 * If an interface attribute was specified,
   1186 			 * consider only children which attach to
   1187 			 * that attribute.
   1188 			 */
   1189 			if (ifattr && !STREQ(ifattr, cfdata_ifattr(cf)))
   1190 				continue;
   1191 
   1192 			if (cfparent_match(parent, cf->cf_pspec))
   1193 				mapply(&m, cf);
   1194 		}
   1195 	}
   1196 	return m.match;
   1197 }
   1198 
   1199 cfdata_t
   1200 config_search(device_t parent, void *aux, cfarg_t tag, ...)
   1201 {
   1202 	cfdata_t cf;
   1203 	va_list ap;
   1204 
   1205 	va_start(ap, tag);
   1206 	cf = config_vsearch(parent, aux, tag, ap);
   1207 	va_end(ap);
   1208 
   1209 	return cf;
   1210 }
   1211 
   1212 /*
   1213  * Find the given root device.
   1214  * This is much like config_search, but there is no parent.
   1215  * Don't bother with multiple cfdata tables; the root node
   1216  * must always be in the initial table.
   1217  */
   1218 cfdata_t
   1219 config_rootsearch(cfsubmatch_t fn, const char *rootname, void *aux)
   1220 {
   1221 	cfdata_t cf;
   1222 	const short *p;
   1223 	struct matchinfo m;
   1224 
   1225 	m.fn = fn;
   1226 	m.parent = ROOT;
   1227 	m.aux = aux;
   1228 	m.match = NULL;
   1229 	m.pri = 0;
   1230 	m.locs = 0;
   1231 	/*
   1232 	 * Look at root entries for matching name.  We do not bother
   1233 	 * with found-state here since only one root should ever be
   1234 	 * searched (and it must be done first).
   1235 	 */
   1236 	for (p = cfroots; *p >= 0; p++) {
   1237 		cf = &cfdata[*p];
   1238 		if (strcmp(cf->cf_name, rootname) == 0)
   1239 			mapply(&m, cf);
   1240 	}
   1241 	return m.match;
   1242 }
   1243 
   1244 static const char * const msgs[] = {
   1245 [QUIET]		=	"",
   1246 [UNCONF]	=	" not configured\n",
   1247 [UNSUPP]	=	" unsupported\n",
   1248 };
   1249 
   1250 /*
   1251  * The given `aux' argument describes a device that has been found
   1252  * on the given parent, but not necessarily configured.  Locate the
   1253  * configuration data for that device (using the submatch function
   1254  * provided, or using candidates' cd_match configuration driver
   1255  * functions) and attach it, and return its device_t.  If the device was
   1256  * not configured, call the given `print' function and return NULL.
   1257  */
   1258 device_t
   1259 config_vfound(device_t parent, void *aux, cfprint_t print, cfarg_t tag,
   1260     va_list ap)
   1261 {
   1262 	cfdata_t cf;
   1263 	va_list nap;
   1264 
   1265 	va_copy(nap, ap);
   1266 	cf = config_vsearch(parent, aux, tag, nap);
   1267 	va_end(nap);
   1268 
   1269 	if (cf != NULL) {
   1270 		return config_vattach(parent, cf, aux, print, tag, ap);
   1271 	}
   1272 
   1273 	if (print) {
   1274 		if (config_do_twiddle && cold)
   1275 			twiddle();
   1276 
   1277 		const int pret = (*print)(aux, device_xname(parent));
   1278 		KASSERT(pret >= 0);
   1279 		KASSERT(pret < __arraycount(msgs));
   1280 		KASSERT(msgs[pret] != NULL);
   1281 		aprint_normal("%s", msgs[pret]);
   1282 	}
   1283 
   1284 	/*
   1285 	 * This has the effect of mixing in a single timestamp to the
   1286 	 * entropy pool.  Experiments indicate the estimator will almost
   1287 	 * always attribute one bit of entropy to this sample; analysis
   1288 	 * of device attach/detach timestamps on FreeBSD indicates 4
   1289 	 * bits of entropy/sample so this seems appropriately conservative.
   1290 	 */
   1291 	rnd_add_uint32(&rnd_autoconf_source, 0);
   1292 	return NULL;
   1293 }
   1294 
   1295 device_t
   1296 config_found(device_t parent, void *aux, cfprint_t print, cfarg_t tag, ...)
   1297 {
   1298 	device_t dev;
   1299 	va_list ap;
   1300 
   1301 	va_start(ap, tag);
   1302 	dev = config_vfound(parent, aux, print, tag, ap);
   1303 	va_end(ap);
   1304 
   1305 	return dev;
   1306 }
   1307 
   1308 /*
   1309  * As above, but for root devices.
   1310  */
   1311 device_t
   1312 config_rootfound(const char *rootname, void *aux)
   1313 {
   1314 	cfdata_t cf;
   1315 	device_t dev = NULL;
   1316 
   1317 	KERNEL_LOCK(1, NULL);
   1318 	if ((cf = config_rootsearch(NULL, rootname, aux)) != NULL)
   1319 		dev = config_attach(ROOT, cf, aux, NULL, CFARG_EOL);
   1320 	else
   1321 		aprint_error("root device %s not configured\n", rootname);
   1322 	KERNEL_UNLOCK_ONE(NULL);
   1323 	return dev;
   1324 }
   1325 
   1326 /* just like sprintf(buf, "%d") except that it works from the end */
   1327 static char *
   1328 number(char *ep, int n)
   1329 {
   1330 
   1331 	*--ep = 0;
   1332 	while (n >= 10) {
   1333 		*--ep = (n % 10) + '0';
   1334 		n /= 10;
   1335 	}
   1336 	*--ep = n + '0';
   1337 	return ep;
   1338 }
   1339 
   1340 /*
   1341  * Expand the size of the cd_devs array if necessary.
   1342  *
   1343  * The caller must hold alldevs_lock. config_makeroom() may release and
   1344  * re-acquire alldevs_lock, so callers should re-check conditions such
   1345  * as alldevs_nwrite == 0 and alldevs_nread == 0 when config_makeroom()
   1346  * returns.
   1347  */
   1348 static void
   1349 config_makeroom(int n, struct cfdriver *cd)
   1350 {
   1351 	int ondevs, nndevs;
   1352 	device_t *osp, *nsp;
   1353 
   1354 	KASSERT(mutex_owned(&alldevs_lock));
   1355 	alldevs_nwrite++;
   1356 
   1357 	for (nndevs = MAX(4, cd->cd_ndevs); nndevs <= n; nndevs += nndevs)
   1358 		;
   1359 
   1360 	while (n >= cd->cd_ndevs) {
   1361 		/*
   1362 		 * Need to expand the array.
   1363 		 */
   1364 		ondevs = cd->cd_ndevs;
   1365 		osp = cd->cd_devs;
   1366 
   1367 		/*
   1368 		 * Release alldevs_lock around allocation, which may
   1369 		 * sleep.
   1370 		 */
   1371 		mutex_exit(&alldevs_lock);
   1372 		nsp = kmem_alloc(sizeof(device_t) * nndevs, KM_SLEEP);
   1373 		mutex_enter(&alldevs_lock);
   1374 
   1375 		/*
   1376 		 * If another thread moved the array while we did
   1377 		 * not hold alldevs_lock, try again.
   1378 		 */
   1379 		if (cd->cd_devs != osp) {
   1380 			mutex_exit(&alldevs_lock);
   1381 			kmem_free(nsp, sizeof(device_t) * nndevs);
   1382 			mutex_enter(&alldevs_lock);
   1383 			continue;
   1384 		}
   1385 
   1386 		memset(nsp + ondevs, 0, sizeof(device_t) * (nndevs - ondevs));
   1387 		if (ondevs != 0)
   1388 			memcpy(nsp, cd->cd_devs, sizeof(device_t) * ondevs);
   1389 
   1390 		cd->cd_ndevs = nndevs;
   1391 		cd->cd_devs = nsp;
   1392 		if (ondevs != 0) {
   1393 			mutex_exit(&alldevs_lock);
   1394 			kmem_free(osp, sizeof(device_t) * ondevs);
   1395 			mutex_enter(&alldevs_lock);
   1396 		}
   1397 	}
   1398 	KASSERT(mutex_owned(&alldevs_lock));
   1399 	alldevs_nwrite--;
   1400 }
   1401 
   1402 /*
   1403  * Put dev into the devices list.
   1404  */
   1405 static void
   1406 config_devlink(device_t dev)
   1407 {
   1408 
   1409 	mutex_enter(&alldevs_lock);
   1410 
   1411 	KASSERT(device_cfdriver(dev)->cd_devs[dev->dv_unit] == dev);
   1412 
   1413 	dev->dv_add_gen = alldevs_gen;
   1414 	/* It is safe to add a device to the tail of the list while
   1415 	 * readers and writers are in the list.
   1416 	 */
   1417 	TAILQ_INSERT_TAIL(&alldevs, dev, dv_list);
   1418 	mutex_exit(&alldevs_lock);
   1419 }
   1420 
   1421 static void
   1422 config_devfree(device_t dev)
   1423 {
   1424 
   1425 	KASSERT(dev->dv_flags & DVF_PRIV_ALLOC);
   1426 	KASSERTMSG(dev->dv_pending == 0, "%d", dev->dv_pending);
   1427 
   1428 	if (dev->dv_cfattach->ca_devsize > 0)
   1429 		kmem_free(dev->dv_private, dev->dv_cfattach->ca_devsize);
   1430 	kmem_free(dev, sizeof(*dev));
   1431 }
   1432 
   1433 /*
   1434  * Caller must hold alldevs_lock.
   1435  */
   1436 static void
   1437 config_devunlink(device_t dev, struct devicelist *garbage)
   1438 {
   1439 	struct device_garbage *dg = &dev->dv_garbage;
   1440 	cfdriver_t cd = device_cfdriver(dev);
   1441 	int i;
   1442 
   1443 	KASSERT(mutex_owned(&alldevs_lock));
   1444 	KASSERTMSG(dev->dv_pending == 0, "%d", dev->dv_pending);
   1445 
   1446  	/* Unlink from device list.  Link to garbage list. */
   1447 	TAILQ_REMOVE(&alldevs, dev, dv_list);
   1448 	TAILQ_INSERT_TAIL(garbage, dev, dv_list);
   1449 
   1450 	/* Remove from cfdriver's array. */
   1451 	cd->cd_devs[dev->dv_unit] = NULL;
   1452 
   1453 	/*
   1454 	 * If the device now has no units in use, unlink its softc array.
   1455 	 */
   1456 	for (i = 0; i < cd->cd_ndevs; i++) {
   1457 		if (cd->cd_devs[i] != NULL)
   1458 			break;
   1459 	}
   1460 	/* Nothing found.  Unlink, now.  Deallocate, later. */
   1461 	if (i == cd->cd_ndevs) {
   1462 		dg->dg_ndevs = cd->cd_ndevs;
   1463 		dg->dg_devs = cd->cd_devs;
   1464 		cd->cd_devs = NULL;
   1465 		cd->cd_ndevs = 0;
   1466 	}
   1467 }
   1468 
   1469 static void
   1470 config_devdelete(device_t dev)
   1471 {
   1472 	struct device_garbage *dg = &dev->dv_garbage;
   1473 	device_lock_t dvl = device_getlock(dev);
   1474 
   1475 	KASSERTMSG(dev->dv_pending == 0, "%d", dev->dv_pending);
   1476 
   1477 	if (dg->dg_devs != NULL)
   1478 		kmem_free(dg->dg_devs, sizeof(device_t) * dg->dg_ndevs);
   1479 
   1480 	cv_destroy(&dvl->dvl_cv);
   1481 	mutex_destroy(&dvl->dvl_mtx);
   1482 
   1483 	KASSERT(dev->dv_properties != NULL);
   1484 	prop_object_release(dev->dv_properties);
   1485 
   1486 	if (dev->dv_activity_handlers)
   1487 		panic("%s with registered handlers", __func__);
   1488 
   1489 	if (dev->dv_locators) {
   1490 		size_t amount = *--dev->dv_locators;
   1491 		kmem_free(dev->dv_locators, amount);
   1492 	}
   1493 
   1494 	config_devfree(dev);
   1495 }
   1496 
   1497 static int
   1498 config_unit_nextfree(cfdriver_t cd, cfdata_t cf)
   1499 {
   1500 	int unit;
   1501 
   1502 	if (cf->cf_fstate == FSTATE_STAR) {
   1503 		for (unit = cf->cf_unit; unit < cd->cd_ndevs; unit++)
   1504 			if (cd->cd_devs[unit] == NULL)
   1505 				break;
   1506 		/*
   1507 		 * unit is now the unit of the first NULL device pointer,
   1508 		 * or max(cd->cd_ndevs,cf->cf_unit).
   1509 		 */
   1510 	} else {
   1511 		unit = cf->cf_unit;
   1512 		if (unit < cd->cd_ndevs && cd->cd_devs[unit] != NULL)
   1513 			unit = -1;
   1514 	}
   1515 	return unit;
   1516 }
   1517 
   1518 static int
   1519 config_unit_alloc(device_t dev, cfdriver_t cd, cfdata_t cf)
   1520 {
   1521 	struct alldevs_foray af;
   1522 	int unit;
   1523 
   1524 	config_alldevs_enter(&af);
   1525 	for (;;) {
   1526 		unit = config_unit_nextfree(cd, cf);
   1527 		if (unit == -1)
   1528 			break;
   1529 		if (unit < cd->cd_ndevs) {
   1530 			cd->cd_devs[unit] = dev;
   1531 			dev->dv_unit = unit;
   1532 			break;
   1533 		}
   1534 		config_makeroom(unit, cd);
   1535 	}
   1536 	config_alldevs_exit(&af);
   1537 
   1538 	return unit;
   1539 }
   1540 
   1541 static device_t
   1542 config_vdevalloc(const device_t parent, const cfdata_t cf, cfarg_t tag,
   1543     va_list ap)
   1544 {
   1545 	cfdriver_t cd;
   1546 	cfattach_t ca;
   1547 	size_t lname, lunit;
   1548 	const char *xunit;
   1549 	int myunit;
   1550 	char num[10];
   1551 	device_t dev;
   1552 	void *dev_private;
   1553 	const struct cfiattrdata *ia;
   1554 	device_lock_t dvl;
   1555 	const int *locs;
   1556 
   1557 	cd = config_cfdriver_lookup(cf->cf_name);
   1558 	if (cd == NULL)
   1559 		return NULL;
   1560 
   1561 	ca = config_cfattach_lookup_cd(cd, cf->cf_atname);
   1562 	if (ca == NULL)
   1563 		return NULL;
   1564 
   1565 	/* get memory for all device vars */
   1566 	KASSERT(ca->ca_flags & DVF_PRIV_ALLOC);
   1567 	if (ca->ca_devsize > 0) {
   1568 		dev_private = kmem_zalloc(ca->ca_devsize, KM_SLEEP);
   1569 	} else {
   1570 		dev_private = NULL;
   1571 	}
   1572 	dev = kmem_zalloc(sizeof(*dev), KM_SLEEP);
   1573 
   1574 	/*
   1575 	 * If a handle was supplied to config_attach(), we'll get it
   1576 	 * assigned automatically here.  If not, then we'll get the
   1577 	 * default invalid handle.
   1578 	 */
   1579 	config_get_cfargs(tag, NULL, NULL, &locs, &dev->dv_handle, ap);
   1580 
   1581 	dev->dv_class = cd->cd_class;
   1582 	dev->dv_cfdata = cf;
   1583 	dev->dv_cfdriver = cd;
   1584 	dev->dv_cfattach = ca;
   1585 	dev->dv_activity_count = 0;
   1586 	dev->dv_activity_handlers = NULL;
   1587 	dev->dv_private = dev_private;
   1588 	dev->dv_flags = ca->ca_flags;	/* inherit flags from class */
   1589 
   1590 	myunit = config_unit_alloc(dev, cd, cf);
   1591 	if (myunit == -1) {
   1592 		config_devfree(dev);
   1593 		return NULL;
   1594 	}
   1595 
   1596 	/* compute length of name and decimal expansion of unit number */
   1597 	lname = strlen(cd->cd_name);
   1598 	xunit = number(&num[sizeof(num)], myunit);
   1599 	lunit = &num[sizeof(num)] - xunit;
   1600 	if (lname + lunit > sizeof(dev->dv_xname))
   1601 		panic("config_vdevalloc: device name too long");
   1602 
   1603 	dvl = device_getlock(dev);
   1604 
   1605 	mutex_init(&dvl->dvl_mtx, MUTEX_DEFAULT, IPL_NONE);
   1606 	cv_init(&dvl->dvl_cv, "pmfsusp");
   1607 
   1608 	memcpy(dev->dv_xname, cd->cd_name, lname);
   1609 	memcpy(dev->dv_xname + lname, xunit, lunit);
   1610 	dev->dv_parent = parent;
   1611 	if (parent != NULL)
   1612 		dev->dv_depth = parent->dv_depth + 1;
   1613 	else
   1614 		dev->dv_depth = 0;
   1615 	dev->dv_flags |= DVF_ACTIVE;	/* always initially active */
   1616 	if (locs) {
   1617 		KASSERT(parent); /* no locators at root */
   1618 		ia = cfiattr_lookup(cfdata_ifattr(cf), parent->dv_cfdriver);
   1619 		dev->dv_locators =
   1620 		    kmem_alloc(sizeof(int) * (ia->ci_loclen + 1), KM_SLEEP);
   1621 		*dev->dv_locators++ = sizeof(int) * (ia->ci_loclen + 1);
   1622 		memcpy(dev->dv_locators, locs, sizeof(int) * ia->ci_loclen);
   1623 	}
   1624 	dev->dv_properties = prop_dictionary_create();
   1625 	KASSERT(dev->dv_properties != NULL);
   1626 
   1627 	prop_dictionary_set_string_nocopy(dev->dv_properties,
   1628 	    "device-driver", dev->dv_cfdriver->cd_name);
   1629 	prop_dictionary_set_uint16(dev->dv_properties,
   1630 	    "device-unit", dev->dv_unit);
   1631 	if (parent != NULL) {
   1632 		prop_dictionary_set_string(dev->dv_properties,
   1633 		    "device-parent", device_xname(parent));
   1634 	}
   1635 
   1636 	if (dev->dv_cfdriver->cd_attrs != NULL)
   1637 		config_add_attrib_dict(dev);
   1638 
   1639 	return dev;
   1640 }
   1641 
   1642 static device_t
   1643 config_devalloc(const device_t parent, const cfdata_t cf, cfarg_t tag, ...)
   1644 {
   1645 	device_t dev;
   1646 	va_list ap;
   1647 
   1648 	va_start(ap, tag);
   1649 	dev = config_vdevalloc(parent, cf, tag, ap);
   1650 	va_end(ap);
   1651 
   1652 	return dev;
   1653 }
   1654 
   1655 /*
   1656  * Create an array of device attach attributes and add it
   1657  * to the device's dv_properties dictionary.
   1658  *
   1659  * <key>interface-attributes</key>
   1660  * <array>
   1661  *    <dict>
   1662  *       <key>attribute-name</key>
   1663  *       <string>foo</string>
   1664  *       <key>locators</key>
   1665  *       <array>
   1666  *          <dict>
   1667  *             <key>loc-name</key>
   1668  *             <string>foo-loc1</string>
   1669  *          </dict>
   1670  *          <dict>
   1671  *             <key>loc-name</key>
   1672  *             <string>foo-loc2</string>
   1673  *             <key>default</key>
   1674  *             <string>foo-loc2-default</string>
   1675  *          </dict>
   1676  *          ...
   1677  *       </array>
   1678  *    </dict>
   1679  *    ...
   1680  * </array>
   1681  */
   1682 
   1683 static void
   1684 config_add_attrib_dict(device_t dev)
   1685 {
   1686 	int i, j;
   1687 	const struct cfiattrdata *ci;
   1688 	prop_dictionary_t attr_dict, loc_dict;
   1689 	prop_array_t attr_array, loc_array;
   1690 
   1691 	if ((attr_array = prop_array_create()) == NULL)
   1692 		return;
   1693 
   1694 	for (i = 0; ; i++) {
   1695 		if ((ci = dev->dv_cfdriver->cd_attrs[i]) == NULL)
   1696 			break;
   1697 		if ((attr_dict = prop_dictionary_create()) == NULL)
   1698 			break;
   1699 		prop_dictionary_set_string_nocopy(attr_dict, "attribute-name",
   1700 		    ci->ci_name);
   1701 
   1702 		/* Create an array of the locator names and defaults */
   1703 
   1704 		if (ci->ci_loclen != 0 &&
   1705 		    (loc_array = prop_array_create()) != NULL) {
   1706 			for (j = 0; j < ci->ci_loclen; j++) {
   1707 				loc_dict = prop_dictionary_create();
   1708 				if (loc_dict == NULL)
   1709 					continue;
   1710 				prop_dictionary_set_string_nocopy(loc_dict,
   1711 				    "loc-name", ci->ci_locdesc[j].cld_name);
   1712 				if (ci->ci_locdesc[j].cld_defaultstr != NULL)
   1713 					prop_dictionary_set_string_nocopy(
   1714 					    loc_dict, "default",
   1715 					    ci->ci_locdesc[j].cld_defaultstr);
   1716 				prop_array_set(loc_array, j, loc_dict);
   1717 				prop_object_release(loc_dict);
   1718 			}
   1719 			prop_dictionary_set_and_rel(attr_dict, "locators",
   1720 			    loc_array);
   1721 		}
   1722 		prop_array_add(attr_array, attr_dict);
   1723 		prop_object_release(attr_dict);
   1724 	}
   1725 	if (i == 0)
   1726 		prop_object_release(attr_array);
   1727 	else
   1728 		prop_dictionary_set_and_rel(dev->dv_properties,
   1729 		    "interface-attributes", attr_array);
   1730 
   1731 	return;
   1732 }
   1733 
   1734 /*
   1735  * Attach a found device.
   1736  */
   1737 device_t
   1738 config_vattach(device_t parent, cfdata_t cf, void *aux, cfprint_t print,
   1739     cfarg_t tag, va_list ap)
   1740 {
   1741 	device_t dev;
   1742 	struct cftable *ct;
   1743 	const char *drvname;
   1744 	bool deferred;
   1745 
   1746 	KASSERT(KERNEL_LOCKED_P());
   1747 
   1748 	dev = config_vdevalloc(parent, cf, tag, ap);
   1749 	if (!dev)
   1750 		panic("config_attach: allocation of device softc failed");
   1751 
   1752 	/* XXX redundant - see below? */
   1753 	if (cf->cf_fstate != FSTATE_STAR) {
   1754 		KASSERT(cf->cf_fstate == FSTATE_NOTFOUND);
   1755 		cf->cf_fstate = FSTATE_FOUND;
   1756 	}
   1757 
   1758 	config_devlink(dev);
   1759 
   1760 	if (config_do_twiddle && cold)
   1761 		twiddle();
   1762 	else
   1763 		aprint_naive("Found ");
   1764 	/*
   1765 	 * We want the next two printfs for normal, verbose, and quiet,
   1766 	 * but not silent (in which case, we're twiddling, instead).
   1767 	 */
   1768 	if (parent == ROOT) {
   1769 		aprint_naive("%s (root)", device_xname(dev));
   1770 		aprint_normal("%s (root)", device_xname(dev));
   1771 	} else {
   1772 		aprint_naive("%s at %s", device_xname(dev),
   1773 		    device_xname(parent));
   1774 		aprint_normal("%s at %s", device_xname(dev),
   1775 		    device_xname(parent));
   1776 		if (print)
   1777 			(void) (*print)(aux, NULL);
   1778 	}
   1779 
   1780 	/*
   1781 	 * Before attaching, clobber any unfound devices that are
   1782 	 * otherwise identical.
   1783 	 * XXX code above is redundant?
   1784 	 */
   1785 	drvname = dev->dv_cfdriver->cd_name;
   1786 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
   1787 		for (cf = ct->ct_cfdata; cf->cf_name; cf++) {
   1788 			if (STREQ(cf->cf_name, drvname) &&
   1789 			    cf->cf_unit == dev->dv_unit) {
   1790 				if (cf->cf_fstate == FSTATE_NOTFOUND)
   1791 					cf->cf_fstate = FSTATE_FOUND;
   1792 			}
   1793 		}
   1794 	}
   1795 	device_register(dev, aux);
   1796 
   1797 	/* Let userland know */
   1798 	devmon_report_device(dev, true);
   1799 
   1800 	config_pending_incr(dev);
   1801 	(*dev->dv_cfattach->ca_attach)(parent, dev, aux);
   1802 	config_pending_decr(dev);
   1803 
   1804 	mutex_enter(&config_misc_lock);
   1805 	deferred = (dev->dv_pending != 0);
   1806 	mutex_exit(&config_misc_lock);
   1807 
   1808 	if (!deferred && !device_pmf_is_registered(dev))
   1809 		aprint_debug_dev(dev,
   1810 		    "WARNING: power management not supported\n");
   1811 
   1812 	config_process_deferred(&deferred_config_queue, dev);
   1813 
   1814 	device_register_post_config(dev, aux);
   1815 	return dev;
   1816 }
   1817 
   1818 device_t
   1819 config_attach(device_t parent, cfdata_t cf, void *aux, cfprint_t print,
   1820     cfarg_t tag, ...)
   1821 {
   1822 	device_t dev;
   1823 	va_list ap;
   1824 
   1825 	KASSERT(KERNEL_LOCKED_P());
   1826 
   1827 	va_start(ap, tag);
   1828 	dev = config_vattach(parent, cf, aux, print, tag, ap);
   1829 	va_end(ap);
   1830 
   1831 	return dev;
   1832 }
   1833 
   1834 /*
   1835  * As above, but for pseudo-devices.  Pseudo-devices attached in this
   1836  * way are silently inserted into the device tree, and their children
   1837  * attached.
   1838  *
   1839  * Note that because pseudo-devices are attached silently, any information
   1840  * the attach routine wishes to print should be prefixed with the device
   1841  * name by the attach routine.
   1842  */
   1843 device_t
   1844 config_attach_pseudo(cfdata_t cf)
   1845 {
   1846 	device_t dev;
   1847 
   1848 	KERNEL_LOCK(1, NULL);
   1849 
   1850 	dev = config_devalloc(ROOT, cf, CFARG_EOL);
   1851 	if (!dev)
   1852 		goto out;
   1853 
   1854 	/* XXX mark busy in cfdata */
   1855 
   1856 	if (cf->cf_fstate != FSTATE_STAR) {
   1857 		KASSERT(cf->cf_fstate == FSTATE_NOTFOUND);
   1858 		cf->cf_fstate = FSTATE_FOUND;
   1859 	}
   1860 
   1861 	config_devlink(dev);
   1862 
   1863 #if 0	/* XXXJRT not yet */
   1864 	device_register(dev, NULL);	/* like a root node */
   1865 #endif
   1866 
   1867 	/* Let userland know */
   1868 	devmon_report_device(dev, true);
   1869 
   1870 	config_pending_incr(dev);
   1871 	(*dev->dv_cfattach->ca_attach)(ROOT, dev, NULL);
   1872 	config_pending_decr(dev);
   1873 
   1874 	config_process_deferred(&deferred_config_queue, dev);
   1875 
   1876 out:	KERNEL_UNLOCK_ONE(NULL);
   1877 	return dev;
   1878 }
   1879 
   1880 /*
   1881  * Caller must hold alldevs_lock.
   1882  */
   1883 static void
   1884 config_collect_garbage(struct devicelist *garbage)
   1885 {
   1886 	device_t dv;
   1887 
   1888 	KASSERT(!cpu_intr_p());
   1889 	KASSERT(!cpu_softintr_p());
   1890 	KASSERT(mutex_owned(&alldevs_lock));
   1891 
   1892 	while (alldevs_nwrite == 0 && alldevs_nread == 0 && alldevs_garbage) {
   1893 		TAILQ_FOREACH(dv, &alldevs, dv_list) {
   1894 			if (dv->dv_del_gen != 0)
   1895 				break;
   1896 		}
   1897 		if (dv == NULL) {
   1898 			alldevs_garbage = false;
   1899 			break;
   1900 		}
   1901 		config_devunlink(dv, garbage);
   1902 	}
   1903 	KASSERT(mutex_owned(&alldevs_lock));
   1904 }
   1905 
   1906 static void
   1907 config_dump_garbage(struct devicelist *garbage)
   1908 {
   1909 	device_t dv;
   1910 
   1911 	while ((dv = TAILQ_FIRST(garbage)) != NULL) {
   1912 		TAILQ_REMOVE(garbage, dv, dv_list);
   1913 		config_devdelete(dv);
   1914 	}
   1915 }
   1916 
   1917 static int
   1918 config_detach_enter(device_t dev)
   1919 {
   1920 	int error;
   1921 
   1922 	mutex_enter(&config_misc_lock);
   1923 	for (;;) {
   1924 		if (dev->dv_pending == 0 && dev->dv_detaching == NULL) {
   1925 			dev->dv_detaching = curlwp;
   1926 			error = 0;
   1927 			break;
   1928 		}
   1929 		KASSERTMSG(dev->dv_detaching != curlwp,
   1930 		    "recursively detaching %s", device_xname(dev));
   1931 		error = cv_wait_sig(&config_misc_cv, &config_misc_lock);
   1932 		if (error)
   1933 			break;
   1934 	}
   1935 	KASSERT(error || dev->dv_detaching == curlwp);
   1936 	mutex_exit(&config_misc_lock);
   1937 
   1938 	return error;
   1939 }
   1940 
   1941 static void
   1942 config_detach_exit(device_t dev)
   1943 {
   1944 
   1945 	mutex_enter(&config_misc_lock);
   1946 	KASSERT(dev->dv_detaching == curlwp);
   1947 	dev->dv_detaching = NULL;
   1948 	cv_broadcast(&config_misc_cv);
   1949 	mutex_exit(&config_misc_lock);
   1950 }
   1951 
   1952 /*
   1953  * Detach a device.  Optionally forced (e.g. because of hardware
   1954  * removal) and quiet.  Returns zero if successful, non-zero
   1955  * (an error code) otherwise.
   1956  *
   1957  * Note that this code wants to be run from a process context, so
   1958  * that the detach can sleep to allow processes which have a device
   1959  * open to run and unwind their stacks.
   1960  */
   1961 int
   1962 config_detach(device_t dev, int flags)
   1963 {
   1964 	struct alldevs_foray af;
   1965 	struct cftable *ct;
   1966 	cfdata_t cf;
   1967 	const struct cfattach *ca;
   1968 	struct cfdriver *cd;
   1969 	device_t d __diagused;
   1970 	int rv = 0;
   1971 
   1972 	KASSERT(KERNEL_LOCKED_P());
   1973 
   1974 	cf = dev->dv_cfdata;
   1975 	KASSERTMSG((cf == NULL || cf->cf_fstate == FSTATE_FOUND ||
   1976 		cf->cf_fstate == FSTATE_STAR),
   1977 	    "config_detach: %s: bad device fstate: %d",
   1978 	    device_xname(dev), cf ? cf->cf_fstate : -1);
   1979 
   1980 	cd = dev->dv_cfdriver;
   1981 	KASSERT(cd != NULL);
   1982 
   1983 	ca = dev->dv_cfattach;
   1984 	KASSERT(ca != NULL);
   1985 
   1986 	/*
   1987 	 * Only one detach at a time, please -- and not until fully
   1988 	 * attached.
   1989 	 */
   1990 	rv = config_detach_enter(dev);
   1991 	if (rv)
   1992 		return rv;
   1993 
   1994 	mutex_enter(&alldevs_lock);
   1995 	if (dev->dv_del_gen != 0) {
   1996 		mutex_exit(&alldevs_lock);
   1997 #ifdef DIAGNOSTIC
   1998 		printf("%s: %s is already detached\n", __func__,
   1999 		    device_xname(dev));
   2000 #endif /* DIAGNOSTIC */
   2001 		config_detach_exit(dev);
   2002 		return ENOENT;
   2003 	}
   2004 	alldevs_nwrite++;
   2005 	mutex_exit(&alldevs_lock);
   2006 
   2007 	if (!detachall &&
   2008 	    (flags & (DETACH_SHUTDOWN|DETACH_FORCE)) == DETACH_SHUTDOWN &&
   2009 	    (dev->dv_flags & DVF_DETACH_SHUTDOWN) == 0) {
   2010 		rv = EOPNOTSUPP;
   2011 	} else if (ca->ca_detach != NULL) {
   2012 		rv = (*ca->ca_detach)(dev, flags);
   2013 	} else
   2014 		rv = EOPNOTSUPP;
   2015 
   2016 	/*
   2017 	 * If it was not possible to detach the device, then we either
   2018 	 * panic() (for the forced but failed case), or return an error.
   2019 	 *
   2020 	 * If it was possible to detach the device, ensure that the
   2021 	 * device is deactivated.
   2022 	 */
   2023 	if (rv == 0)
   2024 		dev->dv_flags &= ~DVF_ACTIVE;
   2025 	else if ((flags & DETACH_FORCE) == 0)
   2026 		goto out;
   2027 	else {
   2028 		panic("config_detach: forced detach of %s failed (%d)",
   2029 		    device_xname(dev), rv);
   2030 	}
   2031 
   2032 	/*
   2033 	 * The device has now been successfully detached.
   2034 	 */
   2035 
   2036 	/* Let userland know */
   2037 	devmon_report_device(dev, false);
   2038 
   2039 #ifdef DIAGNOSTIC
   2040 	/*
   2041 	 * Sanity: If you're successfully detached, you should have no
   2042 	 * children.  (Note that because children must be attached
   2043 	 * after parents, we only need to search the latter part of
   2044 	 * the list.)
   2045 	 */
   2046 	mutex_enter(&alldevs_lock);
   2047 	for (d = TAILQ_NEXT(dev, dv_list); d != NULL;
   2048 	    d = TAILQ_NEXT(d, dv_list)) {
   2049 		if (d->dv_parent == dev && d->dv_del_gen == 0) {
   2050 			printf("config_detach: detached device %s"
   2051 			    " has children %s\n", device_xname(dev),
   2052 			    device_xname(d));
   2053 			panic("config_detach");
   2054 		}
   2055 	}
   2056 	mutex_exit(&alldevs_lock);
   2057 #endif
   2058 
   2059 	/* notify the parent that the child is gone */
   2060 	if (dev->dv_parent) {
   2061 		device_t p = dev->dv_parent;
   2062 		if (p->dv_cfattach->ca_childdetached)
   2063 			(*p->dv_cfattach->ca_childdetached)(p, dev);
   2064 	}
   2065 
   2066 	/*
   2067 	 * Mark cfdata to show that the unit can be reused, if possible.
   2068 	 */
   2069 	TAILQ_FOREACH(ct, &allcftables, ct_list) {
   2070 		for (cf = ct->ct_cfdata; cf->cf_name; cf++) {
   2071 			if (STREQ(cf->cf_name, cd->cd_name)) {
   2072 				if (cf->cf_fstate == FSTATE_FOUND &&
   2073 				    cf->cf_unit == dev->dv_unit)
   2074 					cf->cf_fstate = FSTATE_NOTFOUND;
   2075 			}
   2076 		}
   2077 	}
   2078 
   2079 	if (dev->dv_cfdata != NULL && (flags & DETACH_QUIET) == 0)
   2080 		aprint_normal_dev(dev, "detached\n");
   2081 
   2082 out:
   2083 	config_detach_exit(dev);
   2084 
   2085 	config_alldevs_enter(&af);
   2086 	KASSERT(alldevs_nwrite != 0);
   2087 	--alldevs_nwrite;
   2088 	if (rv == 0 && dev->dv_del_gen == 0) {
   2089 		if (alldevs_nwrite == 0 && alldevs_nread == 0)
   2090 			config_devunlink(dev, &af.af_garbage);
   2091 		else {
   2092 			dev->dv_del_gen = alldevs_gen;
   2093 			alldevs_garbage = true;
   2094 		}
   2095 	}
   2096 	config_alldevs_exit(&af);
   2097 
   2098 	return rv;
   2099 }
   2100 
   2101 int
   2102 config_detach_children(device_t parent, int flags)
   2103 {
   2104 	device_t dv;
   2105 	deviter_t di;
   2106 	int error = 0;
   2107 
   2108 	KASSERT(KERNEL_LOCKED_P());
   2109 
   2110 	for (dv = deviter_first(&di, DEVITER_F_RW); dv != NULL;
   2111 	     dv = deviter_next(&di)) {
   2112 		if (device_parent(dv) != parent)
   2113 			continue;
   2114 		if ((error = config_detach(dv, flags)) != 0)
   2115 			break;
   2116 	}
   2117 	deviter_release(&di);
   2118 	return error;
   2119 }
   2120 
   2121 device_t
   2122 shutdown_first(struct shutdown_state *s)
   2123 {
   2124 	if (!s->initialized) {
   2125 		deviter_init(&s->di, DEVITER_F_SHUTDOWN|DEVITER_F_LEAVES_FIRST);
   2126 		s->initialized = true;
   2127 	}
   2128 	return shutdown_next(s);
   2129 }
   2130 
   2131 device_t
   2132 shutdown_next(struct shutdown_state *s)
   2133 {
   2134 	device_t dv;
   2135 
   2136 	while ((dv = deviter_next(&s->di)) != NULL && !device_is_active(dv))
   2137 		;
   2138 
   2139 	if (dv == NULL)
   2140 		s->initialized = false;
   2141 
   2142 	return dv;
   2143 }
   2144 
   2145 bool
   2146 config_detach_all(int how)
   2147 {
   2148 	static struct shutdown_state s;
   2149 	device_t curdev;
   2150 	bool progress = false;
   2151 	int flags;
   2152 
   2153 	KERNEL_LOCK(1, NULL);
   2154 
   2155 	if ((how & (RB_NOSYNC|RB_DUMP)) != 0)
   2156 		goto out;
   2157 
   2158 	if ((how & RB_POWERDOWN) == RB_POWERDOWN)
   2159 		flags = DETACH_SHUTDOWN | DETACH_POWEROFF;
   2160 	else
   2161 		flags = DETACH_SHUTDOWN;
   2162 
   2163 	for (curdev = shutdown_first(&s); curdev != NULL;
   2164 	     curdev = shutdown_next(&s)) {
   2165 		aprint_debug(" detaching %s, ", device_xname(curdev));
   2166 		if (config_detach(curdev, flags) == 0) {
   2167 			progress = true;
   2168 			aprint_debug("success.");
   2169 		} else
   2170 			aprint_debug("failed.");
   2171 	}
   2172 
   2173 out:	KERNEL_UNLOCK_ONE(NULL);
   2174 	return progress;
   2175 }
   2176 
   2177 static bool
   2178 device_is_ancestor_of(device_t ancestor, device_t descendant)
   2179 {
   2180 	device_t dv;
   2181 
   2182 	for (dv = descendant; dv != NULL; dv = device_parent(dv)) {
   2183 		if (device_parent(dv) == ancestor)
   2184 			return true;
   2185 	}
   2186 	return false;
   2187 }
   2188 
   2189 int
   2190 config_deactivate(device_t dev)
   2191 {
   2192 	deviter_t di;
   2193 	const struct cfattach *ca;
   2194 	device_t descendant;
   2195 	int s, rv = 0, oflags;
   2196 
   2197 	for (descendant = deviter_first(&di, DEVITER_F_ROOT_FIRST);
   2198 	     descendant != NULL;
   2199 	     descendant = deviter_next(&di)) {
   2200 		if (dev != descendant &&
   2201 		    !device_is_ancestor_of(dev, descendant))
   2202 			continue;
   2203 
   2204 		if ((descendant->dv_flags & DVF_ACTIVE) == 0)
   2205 			continue;
   2206 
   2207 		ca = descendant->dv_cfattach;
   2208 		oflags = descendant->dv_flags;
   2209 
   2210 		descendant->dv_flags &= ~DVF_ACTIVE;
   2211 		if (ca->ca_activate == NULL)
   2212 			continue;
   2213 		s = splhigh();
   2214 		rv = (*ca->ca_activate)(descendant, DVACT_DEACTIVATE);
   2215 		splx(s);
   2216 		if (rv != 0)
   2217 			descendant->dv_flags = oflags;
   2218 	}
   2219 	deviter_release(&di);
   2220 	return rv;
   2221 }
   2222 
   2223 /*
   2224  * Defer the configuration of the specified device until all
   2225  * of its parent's devices have been attached.
   2226  */
   2227 void
   2228 config_defer(device_t dev, void (*func)(device_t))
   2229 {
   2230 	struct deferred_config *dc;
   2231 
   2232 	if (dev->dv_parent == NULL)
   2233 		panic("config_defer: can't defer config of a root device");
   2234 
   2235 	dc = kmem_alloc(sizeof(*dc), KM_SLEEP);
   2236 
   2237 	config_pending_incr(dev);
   2238 
   2239 	mutex_enter(&config_misc_lock);
   2240 #ifdef DIAGNOSTIC
   2241 	struct deferred_config *odc;
   2242 	TAILQ_FOREACH(odc, &deferred_config_queue, dc_queue) {
   2243 		if (odc->dc_dev == dev)
   2244 			panic("config_defer: deferred twice");
   2245 	}
   2246 #endif
   2247 	dc->dc_dev = dev;
   2248 	dc->dc_func = func;
   2249 	TAILQ_INSERT_TAIL(&deferred_config_queue, dc, dc_queue);
   2250 	mutex_exit(&config_misc_lock);
   2251 }
   2252 
   2253 /*
   2254  * Defer some autoconfiguration for a device until after interrupts
   2255  * are enabled.
   2256  */
   2257 void
   2258 config_interrupts(device_t dev, void (*func)(device_t))
   2259 {
   2260 	struct deferred_config *dc;
   2261 
   2262 	/*
   2263 	 * If interrupts are enabled, callback now.
   2264 	 */
   2265 	if (cold == 0) {
   2266 		(*func)(dev);
   2267 		return;
   2268 	}
   2269 
   2270 	dc = kmem_alloc(sizeof(*dc), KM_SLEEP);
   2271 
   2272 	config_pending_incr(dev);
   2273 
   2274 	mutex_enter(&config_misc_lock);
   2275 #ifdef DIAGNOSTIC
   2276 	struct deferred_config *odc;
   2277 	TAILQ_FOREACH(odc, &interrupt_config_queue, dc_queue) {
   2278 		if (odc->dc_dev == dev)
   2279 			panic("config_interrupts: deferred twice");
   2280 	}
   2281 #endif
   2282 	dc->dc_dev = dev;
   2283 	dc->dc_func = func;
   2284 	TAILQ_INSERT_TAIL(&interrupt_config_queue, dc, dc_queue);
   2285 	mutex_exit(&config_misc_lock);
   2286 }
   2287 
   2288 /*
   2289  * Defer some autoconfiguration for a device until after root file system
   2290  * is mounted (to load firmware etc).
   2291  */
   2292 void
   2293 config_mountroot(device_t dev, void (*func)(device_t))
   2294 {
   2295 	struct deferred_config *dc;
   2296 
   2297 	/*
   2298 	 * If root file system is mounted, callback now.
   2299 	 */
   2300 	if (root_is_mounted) {
   2301 		(*func)(dev);
   2302 		return;
   2303 	}
   2304 
   2305 	dc = kmem_alloc(sizeof(*dc), KM_SLEEP);
   2306 
   2307 	mutex_enter(&config_misc_lock);
   2308 #ifdef DIAGNOSTIC
   2309 	struct deferred_config *odc;
   2310 	TAILQ_FOREACH(odc, &mountroot_config_queue, dc_queue) {
   2311 		if (odc->dc_dev == dev)
   2312 			panic("%s: deferred twice", __func__);
   2313 	}
   2314 #endif
   2315 
   2316 	dc->dc_dev = dev;
   2317 	dc->dc_func = func;
   2318 	TAILQ_INSERT_TAIL(&mountroot_config_queue, dc, dc_queue);
   2319 	mutex_exit(&config_misc_lock);
   2320 }
   2321 
   2322 /*
   2323  * Process a deferred configuration queue.
   2324  */
   2325 static void
   2326 config_process_deferred(struct deferred_config_head *queue, device_t parent)
   2327 {
   2328 	struct deferred_config *dc;
   2329 
   2330 	KASSERT(KERNEL_LOCKED_P());
   2331 
   2332 	mutex_enter(&config_misc_lock);
   2333 	dc = TAILQ_FIRST(queue);
   2334 	while (dc) {
   2335 		if (parent == NULL || dc->dc_dev->dv_parent == parent) {
   2336 			TAILQ_REMOVE(queue, dc, dc_queue);
   2337 			mutex_exit(&config_misc_lock);
   2338 
   2339 			(*dc->dc_func)(dc->dc_dev);
   2340 			config_pending_decr(dc->dc_dev);
   2341 			kmem_free(dc, sizeof(*dc));
   2342 
   2343 			mutex_enter(&config_misc_lock);
   2344 			/* Restart, queue might have changed */
   2345 			dc = TAILQ_FIRST(queue);
   2346 		} else {
   2347 			dc = TAILQ_NEXT(dc, dc_queue);
   2348 		}
   2349 	}
   2350 	mutex_exit(&config_misc_lock);
   2351 }
   2352 
   2353 /*
   2354  * Manipulate the config_pending semaphore.
   2355  */
   2356 void
   2357 config_pending_incr(device_t dev)
   2358 {
   2359 
   2360 	mutex_enter(&config_misc_lock);
   2361 	KASSERTMSG(dev->dv_pending < INT_MAX,
   2362 	    "%s: excess config_pending_incr", device_xname(dev));
   2363 	if (dev->dv_pending++ == 0)
   2364 		TAILQ_INSERT_TAIL(&config_pending, dev, dv_pending_list);
   2365 #ifdef DEBUG_AUTOCONF
   2366 	printf("%s: %s %d\n", __func__, device_xname(dev), dev->dv_pending);
   2367 #endif
   2368 	mutex_exit(&config_misc_lock);
   2369 }
   2370 
   2371 void
   2372 config_pending_decr(device_t dev)
   2373 {
   2374 
   2375 	mutex_enter(&config_misc_lock);
   2376 	KASSERTMSG(dev->dv_pending > 0,
   2377 	    "%s: excess config_pending_decr", device_xname(dev));
   2378 	if (--dev->dv_pending == 0) {
   2379 		TAILQ_REMOVE(&config_pending, dev, dv_pending_list);
   2380 		cv_broadcast(&config_misc_cv);
   2381 	}
   2382 #ifdef DEBUG_AUTOCONF
   2383 	printf("%s: %s %d\n", __func__, device_xname(dev), dev->dv_pending);
   2384 #endif
   2385 	mutex_exit(&config_misc_lock);
   2386 }
   2387 
   2388 /*
   2389  * Register a "finalization" routine.  Finalization routines are
   2390  * called iteratively once all real devices have been found during
   2391  * autoconfiguration, for as long as any one finalizer has done
   2392  * any work.
   2393  */
   2394 int
   2395 config_finalize_register(device_t dev, int (*fn)(device_t))
   2396 {
   2397 	struct finalize_hook *f;
   2398 	int error = 0;
   2399 
   2400 	KERNEL_LOCK(1, NULL);
   2401 
   2402 	/*
   2403 	 * If finalization has already been done, invoke the
   2404 	 * callback function now.
   2405 	 */
   2406 	if (config_finalize_done) {
   2407 		while ((*fn)(dev) != 0)
   2408 			/* loop */ ;
   2409 		goto out;
   2410 	}
   2411 
   2412 	/* Ensure this isn't already on the list. */
   2413 	TAILQ_FOREACH(f, &config_finalize_list, f_list) {
   2414 		if (f->f_func == fn && f->f_dev == dev) {
   2415 			error = EEXIST;
   2416 			goto out;
   2417 		}
   2418 	}
   2419 
   2420 	f = kmem_alloc(sizeof(*f), KM_SLEEP);
   2421 	f->f_func = fn;
   2422 	f->f_dev = dev;
   2423 	TAILQ_INSERT_TAIL(&config_finalize_list, f, f_list);
   2424 
   2425 	/* Success!  */
   2426 	error = 0;
   2427 
   2428 out:	KERNEL_UNLOCK_ONE(NULL);
   2429 	return error;
   2430 }
   2431 
   2432 void
   2433 config_finalize(void)
   2434 {
   2435 	struct finalize_hook *f;
   2436 	struct pdevinit *pdev;
   2437 	extern struct pdevinit pdevinit[];
   2438 	int errcnt, rv;
   2439 
   2440 	/*
   2441 	 * Now that device driver threads have been created, wait for
   2442 	 * them to finish any deferred autoconfiguration.
   2443 	 */
   2444 	mutex_enter(&config_misc_lock);
   2445 	while (!TAILQ_EMPTY(&config_pending)) {
   2446 		device_t dev;
   2447 		TAILQ_FOREACH(dev, &config_pending, dv_pending_list)
   2448 			aprint_debug_dev(dev, "holding up boot\n");
   2449 		cv_wait(&config_misc_cv, &config_misc_lock);
   2450 	}
   2451 	mutex_exit(&config_misc_lock);
   2452 
   2453 	KERNEL_LOCK(1, NULL);
   2454 
   2455 	/* Attach pseudo-devices. */
   2456 	for (pdev = pdevinit; pdev->pdev_attach != NULL; pdev++)
   2457 		(*pdev->pdev_attach)(pdev->pdev_count);
   2458 
   2459 	/* Run the hooks until none of them does any work. */
   2460 	do {
   2461 		rv = 0;
   2462 		TAILQ_FOREACH(f, &config_finalize_list, f_list)
   2463 			rv |= (*f->f_func)(f->f_dev);
   2464 	} while (rv != 0);
   2465 
   2466 	config_finalize_done = 1;
   2467 
   2468 	/* Now free all the hooks. */
   2469 	while ((f = TAILQ_FIRST(&config_finalize_list)) != NULL) {
   2470 		TAILQ_REMOVE(&config_finalize_list, f, f_list);
   2471 		kmem_free(f, sizeof(*f));
   2472 	}
   2473 
   2474 	KERNEL_UNLOCK_ONE(NULL);
   2475 
   2476 	errcnt = aprint_get_error_count();
   2477 	if ((boothowto & (AB_QUIET|AB_SILENT)) != 0 &&
   2478 	    (boothowto & AB_VERBOSE) == 0) {
   2479 		mutex_enter(&config_misc_lock);
   2480 		if (config_do_twiddle) {
   2481 			config_do_twiddle = 0;
   2482 			printf_nolog(" done.\n");
   2483 		}
   2484 		mutex_exit(&config_misc_lock);
   2485 	}
   2486 	if (errcnt != 0) {
   2487 		printf("WARNING: %d error%s while detecting hardware; "
   2488 		    "check system log.\n", errcnt,
   2489 		    errcnt == 1 ? "" : "s");
   2490 	}
   2491 }
   2492 
   2493 void
   2494 config_twiddle_init(void)
   2495 {
   2496 
   2497 	if ((boothowto & (AB_SILENT|AB_VERBOSE)) == AB_SILENT) {
   2498 		config_do_twiddle = 1;
   2499 	}
   2500 	callout_setfunc(&config_twiddle_ch, config_twiddle_fn, NULL);
   2501 }
   2502 
   2503 void
   2504 config_twiddle_fn(void *cookie)
   2505 {
   2506 
   2507 	mutex_enter(&config_misc_lock);
   2508 	if (config_do_twiddle) {
   2509 		twiddle();
   2510 		callout_schedule(&config_twiddle_ch, mstohz(100));
   2511 	}
   2512 	mutex_exit(&config_misc_lock);
   2513 }
   2514 
   2515 static void
   2516 config_alldevs_enter(struct alldevs_foray *af)
   2517 {
   2518 	TAILQ_INIT(&af->af_garbage);
   2519 	mutex_enter(&alldevs_lock);
   2520 	config_collect_garbage(&af->af_garbage);
   2521 }
   2522 
   2523 static void
   2524 config_alldevs_exit(struct alldevs_foray *af)
   2525 {
   2526 	mutex_exit(&alldevs_lock);
   2527 	config_dump_garbage(&af->af_garbage);
   2528 }
   2529 
   2530 /*
   2531  * device_lookup:
   2532  *
   2533  *	Look up a device instance for a given driver.
   2534  */
   2535 device_t
   2536 device_lookup(cfdriver_t cd, int unit)
   2537 {
   2538 	device_t dv;
   2539 
   2540 	mutex_enter(&alldevs_lock);
   2541 	if (unit < 0 || unit >= cd->cd_ndevs)
   2542 		dv = NULL;
   2543 	else if ((dv = cd->cd_devs[unit]) != NULL && dv->dv_del_gen != 0)
   2544 		dv = NULL;
   2545 	mutex_exit(&alldevs_lock);
   2546 
   2547 	return dv;
   2548 }
   2549 
   2550 /*
   2551  * device_lookup_private:
   2552  *
   2553  *	Look up a softc instance for a given driver.
   2554  */
   2555 void *
   2556 device_lookup_private(cfdriver_t cd, int unit)
   2557 {
   2558 
   2559 	return device_private(device_lookup(cd, unit));
   2560 }
   2561 
   2562 /*
   2563  * device_find_by_xname:
   2564  *
   2565  *	Returns the device of the given name or NULL if it doesn't exist.
   2566  */
   2567 device_t
   2568 device_find_by_xname(const char *name)
   2569 {
   2570 	device_t dv;
   2571 	deviter_t di;
   2572 
   2573 	for (dv = deviter_first(&di, 0); dv != NULL; dv = deviter_next(&di)) {
   2574 		if (strcmp(device_xname(dv), name) == 0)
   2575 			break;
   2576 	}
   2577 	deviter_release(&di);
   2578 
   2579 	return dv;
   2580 }
   2581 
   2582 /*
   2583  * device_find_by_driver_unit:
   2584  *
   2585  *	Returns the device of the given driver name and unit or
   2586  *	NULL if it doesn't exist.
   2587  */
   2588 device_t
   2589 device_find_by_driver_unit(const char *name, int unit)
   2590 {
   2591 	struct cfdriver *cd;
   2592 
   2593 	if ((cd = config_cfdriver_lookup(name)) == NULL)
   2594 		return NULL;
   2595 	return device_lookup(cd, unit);
   2596 }
   2597 
   2598 static bool
   2599 match_strcmp(const char * const s1, const char * const s2)
   2600 {
   2601 	return strcmp(s1, s2) == 0;
   2602 }
   2603 
   2604 static bool
   2605 match_pmatch(const char * const s1, const char * const s2)
   2606 {
   2607 	return pmatch(s1, s2, NULL) == 2;
   2608 }
   2609 
   2610 static bool
   2611 strarray_match_internal(const char ** const strings,
   2612     unsigned int const nstrings, const char * const str,
   2613     unsigned int * const indexp,
   2614     bool (*match_fn)(const char *, const char *))
   2615 {
   2616 	unsigned int i;
   2617 
   2618 	if (strings == NULL || nstrings == 0) {
   2619 		return false;
   2620 	}
   2621 
   2622 	for (i = 0; i < nstrings; i++) {
   2623 		if ((*match_fn)(strings[i], str)) {
   2624 			*indexp = i;
   2625 			return true;
   2626 		}
   2627 	}
   2628 
   2629 	return false;
   2630 }
   2631 
   2632 static int
   2633 strarray_match(const char ** const strings, unsigned int const nstrings,
   2634     const char * const str)
   2635 {
   2636 	unsigned int idx;
   2637 
   2638 	if (strarray_match_internal(strings, nstrings, str, &idx,
   2639 				    match_strcmp)) {
   2640 		return (int)(nstrings - idx);
   2641 	}
   2642 	return 0;
   2643 }
   2644 
   2645 static int
   2646 strarray_pmatch(const char ** const strings, unsigned int const nstrings,
   2647     const char * const pattern)
   2648 {
   2649 	unsigned int idx;
   2650 
   2651 	if (strarray_match_internal(strings, nstrings, pattern, &idx,
   2652 				    match_pmatch)) {
   2653 		return (int)(nstrings - idx);
   2654 	}
   2655 	return 0;
   2656 }
   2657 
   2658 static int
   2659 device_compatible_match_strarray_internal(
   2660     const char **device_compats, int ndevice_compats,
   2661     const struct device_compatible_entry *driver_compats,
   2662     const struct device_compatible_entry **matching_entryp,
   2663     int (*match_fn)(const char **, unsigned int, const char *))
   2664 {
   2665 	const struct device_compatible_entry *dce = NULL;
   2666 	int rv;
   2667 
   2668 	if (ndevice_compats == 0 || device_compats == NULL ||
   2669 	    driver_compats == NULL)
   2670 		return 0;
   2671 
   2672 	for (dce = driver_compats; dce->compat != NULL; dce++) {
   2673 		rv = (*match_fn)(device_compats, ndevice_compats, dce->compat);
   2674 		if (rv != 0) {
   2675 			if (matching_entryp != NULL) {
   2676 				*matching_entryp = dce;
   2677 			}
   2678 			return rv;
   2679 		}
   2680 	}
   2681 	return 0;
   2682 }
   2683 
   2684 /*
   2685  * device_compatible_match:
   2686  *
   2687  *	Match a driver's "compatible" data against a device's
   2688  *	"compatible" strings.  Returns resulted weighted by
   2689  *	which device "compatible" string was matched.
   2690  */
   2691 int
   2692 device_compatible_match(const char **device_compats, int ndevice_compats,
   2693     const struct device_compatible_entry *driver_compats)
   2694 {
   2695 	return device_compatible_match_strarray_internal(device_compats,
   2696 	    ndevice_compats, driver_compats, NULL, strarray_match);
   2697 }
   2698 
   2699 /*
   2700  * device_compatible_pmatch:
   2701  *
   2702  *	Like device_compatible_match(), but uses pmatch(9) to compare
   2703  *	the device "compatible" strings against patterns in the
   2704  *	driver's "compatible" data.
   2705  */
   2706 int
   2707 device_compatible_pmatch(const char **device_compats, int ndevice_compats,
   2708     const struct device_compatible_entry *driver_compats)
   2709 {
   2710 	return device_compatible_match_strarray_internal(device_compats,
   2711 	    ndevice_compats, driver_compats, NULL, strarray_pmatch);
   2712 }
   2713 
   2714 static int
   2715 device_compatible_match_strlist_internal(
   2716     const char * const device_compats, size_t const device_compatsize,
   2717     const struct device_compatible_entry *driver_compats,
   2718     const struct device_compatible_entry **matching_entryp,
   2719     int (*match_fn)(const char *, size_t, const char *))
   2720 {
   2721 	const struct device_compatible_entry *dce = NULL;
   2722 	int rv;
   2723 
   2724 	if (device_compats == NULL || device_compatsize == 0 ||
   2725 	    driver_compats == NULL)
   2726 		return 0;
   2727 
   2728 	for (dce = driver_compats; dce->compat != NULL; dce++) {
   2729 		rv = (*match_fn)(device_compats, device_compatsize,
   2730 		    dce->compat);
   2731 		if (rv != 0) {
   2732 			if (matching_entryp != NULL) {
   2733 				*matching_entryp = dce;
   2734 			}
   2735 			return rv;
   2736 		}
   2737 	}
   2738 	return 0;
   2739 }
   2740 
   2741 /*
   2742  * device_compatible_match_strlist:
   2743  *
   2744  *	Like device_compatible_match(), but take the device
   2745  *	"compatible" strings as an OpenFirmware-style string
   2746  *	list.
   2747  */
   2748 int
   2749 device_compatible_match_strlist(
   2750     const char * const device_compats, size_t const device_compatsize,
   2751     const struct device_compatible_entry *driver_compats)
   2752 {
   2753 	return device_compatible_match_strlist_internal(device_compats,
   2754 	    device_compatsize, driver_compats, NULL, strlist_match);
   2755 }
   2756 
   2757 /*
   2758  * device_compatible_pmatch_strlist:
   2759  *
   2760  *	Like device_compatible_pmatch(), but take the device
   2761  *	"compatible" strings as an OpenFirmware-style string
   2762  *	list.
   2763  */
   2764 int
   2765 device_compatible_pmatch_strlist(
   2766     const char * const device_compats, size_t const device_compatsize,
   2767     const struct device_compatible_entry *driver_compats)
   2768 {
   2769 	return device_compatible_match_strlist_internal(device_compats,
   2770 	    device_compatsize, driver_compats, NULL, strlist_pmatch);
   2771 }
   2772 
   2773 static int
   2774 device_compatible_match_id_internal(
   2775     uintptr_t const id, uintptr_t const mask, uintptr_t const sentinel_id,
   2776     const struct device_compatible_entry *driver_compats,
   2777     const struct device_compatible_entry **matching_entryp)
   2778 {
   2779 	const struct device_compatible_entry *dce = NULL;
   2780 
   2781 	if (mask == 0)
   2782 		return 0;
   2783 
   2784 	for (dce = driver_compats; dce->id != sentinel_id; dce++) {
   2785 		if ((id & mask) == dce->id) {
   2786 			if (matching_entryp != NULL) {
   2787 				*matching_entryp = dce;
   2788 			}
   2789 			return 1;
   2790 		}
   2791 	}
   2792 	return 0;
   2793 }
   2794 
   2795 /*
   2796  * device_compatible_match_id:
   2797  *
   2798  *	Like device_compatible_match(), but takes a single
   2799  *	unsigned integer device ID.
   2800  */
   2801 int
   2802 device_compatible_match_id(
   2803     uintptr_t const id, uintptr_t const sentinel_id,
   2804     const struct device_compatible_entry *driver_compats)
   2805 {
   2806 	return device_compatible_match_id_internal(id, (uintptr_t)-1,
   2807 	    sentinel_id, driver_compats, NULL);
   2808 }
   2809 
   2810 /*
   2811  * device_compatible_lookup:
   2812  *
   2813  *	Look up and return the device_compatible_entry, using the
   2814  *	same matching criteria used by device_compatible_match().
   2815  */
   2816 const struct device_compatible_entry *
   2817 device_compatible_lookup(const char **device_compats, int ndevice_compats,
   2818 			 const struct device_compatible_entry *driver_compats)
   2819 {
   2820 	const struct device_compatible_entry *dce;
   2821 
   2822 	if (device_compatible_match_strarray_internal(device_compats,
   2823 	    ndevice_compats, driver_compats, &dce, strarray_match)) {
   2824 		return dce;
   2825 	}
   2826 	return NULL;
   2827 }
   2828 
   2829 /*
   2830  * device_compatible_plookup:
   2831  *
   2832  *	Look up and return the device_compatible_entry, using the
   2833  *	same matching criteria used by device_compatible_pmatch().
   2834  */
   2835 const struct device_compatible_entry *
   2836 device_compatible_plookup(const char **device_compats, int ndevice_compats,
   2837 			  const struct device_compatible_entry *driver_compats)
   2838 {
   2839 	const struct device_compatible_entry *dce;
   2840 
   2841 	if (device_compatible_match_strarray_internal(device_compats,
   2842 	    ndevice_compats, driver_compats, &dce, strarray_pmatch)) {
   2843 		return dce;
   2844 	}
   2845 	return NULL;
   2846 }
   2847 
   2848 /*
   2849  * device_compatible_lookup_strlist:
   2850  *
   2851  *	Like device_compatible_lookup(), but take the device
   2852  *	"compatible" strings as an OpenFirmware-style string
   2853  *	list.
   2854  */
   2855 const struct device_compatible_entry *
   2856 device_compatible_lookup_strlist(
   2857     const char * const device_compats, size_t const device_compatsize,
   2858     const struct device_compatible_entry *driver_compats)
   2859 {
   2860 	const struct device_compatible_entry *dce;
   2861 
   2862 	if (device_compatible_match_strlist_internal(device_compats,
   2863 	    device_compatsize, driver_compats, &dce, strlist_match)) {
   2864 		return dce;
   2865 	}
   2866 	return NULL;
   2867 }
   2868 
   2869 /*
   2870  * device_compatible_plookup_strlist:
   2871  *
   2872  *	Like device_compatible_plookup(), but take the device
   2873  *	"compatible" strings as an OpenFirmware-style string
   2874  *	list.
   2875  */
   2876 const struct device_compatible_entry *
   2877 device_compatible_plookup_strlist(
   2878     const char * const device_compats, size_t const device_compatsize,
   2879     const struct device_compatible_entry *driver_compats)
   2880 {
   2881 	const struct device_compatible_entry *dce;
   2882 
   2883 	if (device_compatible_match_strlist_internal(device_compats,
   2884 	    device_compatsize, driver_compats, &dce, strlist_pmatch)) {
   2885 		return dce;
   2886 	}
   2887 	return NULL;
   2888 }
   2889 
   2890 /*
   2891  * device_compatible_lookup_id:
   2892  *
   2893  *	Like device_compatible_lookup(), but takes a single
   2894  *	unsigned integer device ID.
   2895  */
   2896 const struct device_compatible_entry *
   2897 device_compatible_lookup_id(
   2898     uintptr_t const id, uintptr_t const sentinel_id,
   2899     const struct device_compatible_entry *driver_compats)
   2900 {
   2901 	const struct device_compatible_entry *dce;
   2902 
   2903 	if (device_compatible_match_id_internal(id, (uintptr_t)-1,
   2904 	    sentinel_id, driver_compats, &dce)) {
   2905 		return dce;
   2906 	}
   2907 	return NULL;
   2908 }
   2909 
   2910 /*
   2911  * Power management related functions.
   2912  */
   2913 
   2914 bool
   2915 device_pmf_is_registered(device_t dev)
   2916 {
   2917 	return (dev->dv_flags & DVF_POWER_HANDLERS) != 0;
   2918 }
   2919 
   2920 bool
   2921 device_pmf_driver_suspend(device_t dev, const pmf_qual_t *qual)
   2922 {
   2923 	if ((dev->dv_flags & DVF_DRIVER_SUSPENDED) != 0)
   2924 		return true;
   2925 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) == 0)
   2926 		return false;
   2927 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_DRIVER &&
   2928 	    dev->dv_driver_suspend != NULL &&
   2929 	    !(*dev->dv_driver_suspend)(dev, qual))
   2930 		return false;
   2931 
   2932 	dev->dv_flags |= DVF_DRIVER_SUSPENDED;
   2933 	return true;
   2934 }
   2935 
   2936 bool
   2937 device_pmf_driver_resume(device_t dev, const pmf_qual_t *qual)
   2938 {
   2939 	if ((dev->dv_flags & DVF_DRIVER_SUSPENDED) == 0)
   2940 		return true;
   2941 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) != 0)
   2942 		return false;
   2943 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_DRIVER &&
   2944 	    dev->dv_driver_resume != NULL &&
   2945 	    !(*dev->dv_driver_resume)(dev, qual))
   2946 		return false;
   2947 
   2948 	dev->dv_flags &= ~DVF_DRIVER_SUSPENDED;
   2949 	return true;
   2950 }
   2951 
   2952 bool
   2953 device_pmf_driver_shutdown(device_t dev, int how)
   2954 {
   2955 
   2956 	if (*dev->dv_driver_shutdown != NULL &&
   2957 	    !(*dev->dv_driver_shutdown)(dev, how))
   2958 		return false;
   2959 	return true;
   2960 }
   2961 
   2962 bool
   2963 device_pmf_driver_register(device_t dev,
   2964     bool (*suspend)(device_t, const pmf_qual_t *),
   2965     bool (*resume)(device_t, const pmf_qual_t *),
   2966     bool (*shutdown)(device_t, int))
   2967 {
   2968 	dev->dv_driver_suspend = suspend;
   2969 	dev->dv_driver_resume = resume;
   2970 	dev->dv_driver_shutdown = shutdown;
   2971 	dev->dv_flags |= DVF_POWER_HANDLERS;
   2972 	return true;
   2973 }
   2974 
   2975 static const char *
   2976 curlwp_name(void)
   2977 {
   2978 	if (curlwp->l_name != NULL)
   2979 		return curlwp->l_name;
   2980 	else
   2981 		return curlwp->l_proc->p_comm;
   2982 }
   2983 
   2984 void
   2985 device_pmf_driver_deregister(device_t dev)
   2986 {
   2987 	device_lock_t dvl = device_getlock(dev);
   2988 
   2989 	dev->dv_driver_suspend = NULL;
   2990 	dev->dv_driver_resume = NULL;
   2991 
   2992 	mutex_enter(&dvl->dvl_mtx);
   2993 	dev->dv_flags &= ~DVF_POWER_HANDLERS;
   2994 	while (dvl->dvl_nlock > 0 || dvl->dvl_nwait > 0) {
   2995 		/* Wake a thread that waits for the lock.  That
   2996 		 * thread will fail to acquire the lock, and then
   2997 		 * it will wake the next thread that waits for the
   2998 		 * lock, or else it will wake us.
   2999 		 */
   3000 		cv_signal(&dvl->dvl_cv);
   3001 		pmflock_debug(dev, __func__, __LINE__);
   3002 		cv_wait(&dvl->dvl_cv, &dvl->dvl_mtx);
   3003 		pmflock_debug(dev, __func__, __LINE__);
   3004 	}
   3005 	mutex_exit(&dvl->dvl_mtx);
   3006 }
   3007 
   3008 bool
   3009 device_pmf_driver_child_register(device_t dev)
   3010 {
   3011 	device_t parent = device_parent(dev);
   3012 
   3013 	if (parent == NULL || parent->dv_driver_child_register == NULL)
   3014 		return true;
   3015 	return (*parent->dv_driver_child_register)(dev);
   3016 }
   3017 
   3018 void
   3019 device_pmf_driver_set_child_register(device_t dev,
   3020     bool (*child_register)(device_t))
   3021 {
   3022 	dev->dv_driver_child_register = child_register;
   3023 }
   3024 
   3025 static void
   3026 pmflock_debug(device_t dev, const char *func, int line)
   3027 {
   3028 	device_lock_t dvl = device_getlock(dev);
   3029 
   3030 	aprint_debug_dev(dev,
   3031 	    "%s.%d, %s dvl_nlock %d dvl_nwait %d dv_flags %x\n", func, line,
   3032 	    curlwp_name(), dvl->dvl_nlock, dvl->dvl_nwait, dev->dv_flags);
   3033 }
   3034 
   3035 static bool
   3036 device_pmf_lock1(device_t dev)
   3037 {
   3038 	device_lock_t dvl = device_getlock(dev);
   3039 
   3040 	while (device_pmf_is_registered(dev) &&
   3041 	    dvl->dvl_nlock > 0 && dvl->dvl_holder != curlwp) {
   3042 		dvl->dvl_nwait++;
   3043 		pmflock_debug(dev, __func__, __LINE__);
   3044 		cv_wait(&dvl->dvl_cv, &dvl->dvl_mtx);
   3045 		pmflock_debug(dev, __func__, __LINE__);
   3046 		dvl->dvl_nwait--;
   3047 	}
   3048 	if (!device_pmf_is_registered(dev)) {
   3049 		pmflock_debug(dev, __func__, __LINE__);
   3050 		/* We could not acquire the lock, but some other thread may
   3051 		 * wait for it, also.  Wake that thread.
   3052 		 */
   3053 		cv_signal(&dvl->dvl_cv);
   3054 		return false;
   3055 	}
   3056 	dvl->dvl_nlock++;
   3057 	dvl->dvl_holder = curlwp;
   3058 	pmflock_debug(dev, __func__, __LINE__);
   3059 	return true;
   3060 }
   3061 
   3062 bool
   3063 device_pmf_lock(device_t dev)
   3064 {
   3065 	bool rc;
   3066 	device_lock_t dvl = device_getlock(dev);
   3067 
   3068 	mutex_enter(&dvl->dvl_mtx);
   3069 	rc = device_pmf_lock1(dev);
   3070 	mutex_exit(&dvl->dvl_mtx);
   3071 
   3072 	return rc;
   3073 }
   3074 
   3075 void
   3076 device_pmf_unlock(device_t dev)
   3077 {
   3078 	device_lock_t dvl = device_getlock(dev);
   3079 
   3080 	KASSERT(dvl->dvl_nlock > 0);
   3081 	mutex_enter(&dvl->dvl_mtx);
   3082 	if (--dvl->dvl_nlock == 0)
   3083 		dvl->dvl_holder = NULL;
   3084 	cv_signal(&dvl->dvl_cv);
   3085 	pmflock_debug(dev, __func__, __LINE__);
   3086 	mutex_exit(&dvl->dvl_mtx);
   3087 }
   3088 
   3089 device_lock_t
   3090 device_getlock(device_t dev)
   3091 {
   3092 	return &dev->dv_lock;
   3093 }
   3094 
   3095 void *
   3096 device_pmf_bus_private(device_t dev)
   3097 {
   3098 	return dev->dv_bus_private;
   3099 }
   3100 
   3101 bool
   3102 device_pmf_bus_suspend(device_t dev, const pmf_qual_t *qual)
   3103 {
   3104 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) != 0)
   3105 		return true;
   3106 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) == 0 ||
   3107 	    (dev->dv_flags & DVF_DRIVER_SUSPENDED) == 0)
   3108 		return false;
   3109 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_BUS &&
   3110 	    dev->dv_bus_suspend != NULL &&
   3111 	    !(*dev->dv_bus_suspend)(dev, qual))
   3112 		return false;
   3113 
   3114 	dev->dv_flags |= DVF_BUS_SUSPENDED;
   3115 	return true;
   3116 }
   3117 
   3118 bool
   3119 device_pmf_bus_resume(device_t dev, const pmf_qual_t *qual)
   3120 {
   3121 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) == 0)
   3122 		return true;
   3123 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_BUS &&
   3124 	    dev->dv_bus_resume != NULL &&
   3125 	    !(*dev->dv_bus_resume)(dev, qual))
   3126 		return false;
   3127 
   3128 	dev->dv_flags &= ~DVF_BUS_SUSPENDED;
   3129 	return true;
   3130 }
   3131 
   3132 bool
   3133 device_pmf_bus_shutdown(device_t dev, int how)
   3134 {
   3135 
   3136 	if (*dev->dv_bus_shutdown != NULL &&
   3137 	    !(*dev->dv_bus_shutdown)(dev, how))
   3138 		return false;
   3139 	return true;
   3140 }
   3141 
   3142 void
   3143 device_pmf_bus_register(device_t dev, void *priv,
   3144     bool (*suspend)(device_t, const pmf_qual_t *),
   3145     bool (*resume)(device_t, const pmf_qual_t *),
   3146     bool (*shutdown)(device_t, int), void (*deregister)(device_t))
   3147 {
   3148 	dev->dv_bus_private = priv;
   3149 	dev->dv_bus_resume = resume;
   3150 	dev->dv_bus_suspend = suspend;
   3151 	dev->dv_bus_shutdown = shutdown;
   3152 	dev->dv_bus_deregister = deregister;
   3153 }
   3154 
   3155 void
   3156 device_pmf_bus_deregister(device_t dev)
   3157 {
   3158 	if (dev->dv_bus_deregister == NULL)
   3159 		return;
   3160 	(*dev->dv_bus_deregister)(dev);
   3161 	dev->dv_bus_private = NULL;
   3162 	dev->dv_bus_suspend = NULL;
   3163 	dev->dv_bus_resume = NULL;
   3164 	dev->dv_bus_deregister = NULL;
   3165 }
   3166 
   3167 void *
   3168 device_pmf_class_private(device_t dev)
   3169 {
   3170 	return dev->dv_class_private;
   3171 }
   3172 
   3173 bool
   3174 device_pmf_class_suspend(device_t dev, const pmf_qual_t *qual)
   3175 {
   3176 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) != 0)
   3177 		return true;
   3178 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_CLASS &&
   3179 	    dev->dv_class_suspend != NULL &&
   3180 	    !(*dev->dv_class_suspend)(dev, qual))
   3181 		return false;
   3182 
   3183 	dev->dv_flags |= DVF_CLASS_SUSPENDED;
   3184 	return true;
   3185 }
   3186 
   3187 bool
   3188 device_pmf_class_resume(device_t dev, const pmf_qual_t *qual)
   3189 {
   3190 	if ((dev->dv_flags & DVF_CLASS_SUSPENDED) == 0)
   3191 		return true;
   3192 	if ((dev->dv_flags & DVF_BUS_SUSPENDED) != 0 ||
   3193 	    (dev->dv_flags & DVF_DRIVER_SUSPENDED) != 0)
   3194 		return false;
   3195 	if (pmf_qual_depth(qual) <= DEVACT_LEVEL_CLASS &&
   3196 	    dev->dv_class_resume != NULL &&
   3197 	    !(*dev->dv_class_resume)(dev, qual))
   3198 		return false;
   3199 
   3200 	dev->dv_flags &= ~DVF_CLASS_SUSPENDED;
   3201 	return true;
   3202 }
   3203 
   3204 void
   3205 device_pmf_class_register(device_t dev, void *priv,
   3206     bool (*suspend)(device_t, const pmf_qual_t *),
   3207     bool (*resume)(device_t, const pmf_qual_t *),
   3208     void (*deregister)(device_t))
   3209 {
   3210 	dev->dv_class_private = priv;
   3211 	dev->dv_class_suspend = suspend;
   3212 	dev->dv_class_resume = resume;
   3213 	dev->dv_class_deregister = deregister;
   3214 }
   3215 
   3216 void
   3217 device_pmf_class_deregister(device_t dev)
   3218 {
   3219 	if (dev->dv_class_deregister == NULL)
   3220 		return;
   3221 	(*dev->dv_class_deregister)(dev);
   3222 	dev->dv_class_private = NULL;
   3223 	dev->dv_class_suspend = NULL;
   3224 	dev->dv_class_resume = NULL;
   3225 	dev->dv_class_deregister = NULL;
   3226 }
   3227 
   3228 bool
   3229 device_active(device_t dev, devactive_t type)
   3230 {
   3231 	size_t i;
   3232 
   3233 	if (dev->dv_activity_count == 0)
   3234 		return false;
   3235 
   3236 	for (i = 0; i < dev->dv_activity_count; ++i) {
   3237 		if (dev->dv_activity_handlers[i] == NULL)
   3238 			break;
   3239 		(*dev->dv_activity_handlers[i])(dev, type);
   3240 	}
   3241 
   3242 	return true;
   3243 }
   3244 
   3245 bool
   3246 device_active_register(device_t dev, void (*handler)(device_t, devactive_t))
   3247 {
   3248 	void (**new_handlers)(device_t, devactive_t);
   3249 	void (**old_handlers)(device_t, devactive_t);
   3250 	size_t i, old_size, new_size;
   3251 	int s;
   3252 
   3253 	old_handlers = dev->dv_activity_handlers;
   3254 	old_size = dev->dv_activity_count;
   3255 
   3256 	KASSERT(old_size == 0 || old_handlers != NULL);
   3257 
   3258 	for (i = 0; i < old_size; ++i) {
   3259 		KASSERT(old_handlers[i] != handler);
   3260 		if (old_handlers[i] == NULL) {
   3261 			old_handlers[i] = handler;
   3262 			return true;
   3263 		}
   3264 	}
   3265 
   3266 	new_size = old_size + 4;
   3267 	new_handlers = kmem_alloc(sizeof(void *) * new_size, KM_SLEEP);
   3268 
   3269 	for (i = 0; i < old_size; ++i)
   3270 		new_handlers[i] = old_handlers[i];
   3271 	new_handlers[old_size] = handler;
   3272 	for (i = old_size+1; i < new_size; ++i)
   3273 		new_handlers[i] = NULL;
   3274 
   3275 	s = splhigh();
   3276 	dev->dv_activity_count = new_size;
   3277 	dev->dv_activity_handlers = new_handlers;
   3278 	splx(s);
   3279 
   3280 	if (old_size > 0)
   3281 		kmem_free(old_handlers, sizeof(void *) * old_size);
   3282 
   3283 	return true;
   3284 }
   3285 
   3286 void
   3287 device_active_deregister(device_t dev, void (*handler)(device_t, devactive_t))
   3288 {
   3289 	void (**old_handlers)(device_t, devactive_t);
   3290 	size_t i, old_size;
   3291 	int s;
   3292 
   3293 	old_handlers = dev->dv_activity_handlers;
   3294 	old_size = dev->dv_activity_count;
   3295 
   3296 	for (i = 0; i < old_size; ++i) {
   3297 		if (old_handlers[i] == handler)
   3298 			break;
   3299 		if (old_handlers[i] == NULL)
   3300 			return; /* XXX panic? */
   3301 	}
   3302 
   3303 	if (i == old_size)
   3304 		return; /* XXX panic? */
   3305 
   3306 	for (; i < old_size - 1; ++i) {
   3307 		if ((old_handlers[i] = old_handlers[i + 1]) != NULL)
   3308 			continue;
   3309 
   3310 		if (i == 0) {
   3311 			s = splhigh();
   3312 			dev->dv_activity_count = 0;
   3313 			dev->dv_activity_handlers = NULL;
   3314 			splx(s);
   3315 			kmem_free(old_handlers, sizeof(void *) * old_size);
   3316 		}
   3317 		return;
   3318 	}
   3319 	old_handlers[i] = NULL;
   3320 }
   3321 
   3322 /* Return true iff the device_t `dev' exists at generation `gen'. */
   3323 static bool
   3324 device_exists_at(device_t dv, devgen_t gen)
   3325 {
   3326 	return (dv->dv_del_gen == 0 || dv->dv_del_gen > gen) &&
   3327 	    dv->dv_add_gen <= gen;
   3328 }
   3329 
   3330 static bool
   3331 deviter_visits(const deviter_t *di, device_t dv)
   3332 {
   3333 	return device_exists_at(dv, di->di_gen);
   3334 }
   3335 
   3336 /*
   3337  * Device Iteration
   3338  *
   3339  * deviter_t: a device iterator.  Holds state for a "walk" visiting
   3340  *     each device_t's in the device tree.
   3341  *
   3342  * deviter_init(di, flags): initialize the device iterator `di'
   3343  *     to "walk" the device tree.  deviter_next(di) will return
   3344  *     the first device_t in the device tree, or NULL if there are
   3345  *     no devices.
   3346  *
   3347  *     `flags' is one or more of DEVITER_F_RW, indicating that the
   3348  *     caller intends to modify the device tree by calling
   3349  *     config_detach(9) on devices in the order that the iterator
   3350  *     returns them; DEVITER_F_ROOT_FIRST, asking for the devices
   3351  *     nearest the "root" of the device tree to be returned, first;
   3352  *     DEVITER_F_LEAVES_FIRST, asking for the devices furthest from
   3353  *     the root of the device tree, first; and DEVITER_F_SHUTDOWN,
   3354  *     indicating both that deviter_init() should not respect any
   3355  *     locks on the device tree, and that deviter_next(di) may run
   3356  *     in more than one LWP before the walk has finished.
   3357  *
   3358  *     Only one DEVITER_F_RW iterator may be in the device tree at
   3359  *     once.
   3360  *
   3361  *     DEVITER_F_SHUTDOWN implies DEVITER_F_RW.
   3362  *
   3363  *     Results are undefined if the flags DEVITER_F_ROOT_FIRST and
   3364  *     DEVITER_F_LEAVES_FIRST are used in combination.
   3365  *
   3366  * deviter_first(di, flags): initialize the device iterator `di'
   3367  *     and return the first device_t in the device tree, or NULL
   3368  *     if there are no devices.  The statement
   3369  *
   3370  *         dv = deviter_first(di);
   3371  *
   3372  *     is shorthand for
   3373  *
   3374  *         deviter_init(di);
   3375  *         dv = deviter_next(di);
   3376  *
   3377  * deviter_next(di): return the next device_t in the device tree,
   3378  *     or NULL if there are no more devices.  deviter_next(di)
   3379  *     is undefined if `di' was not initialized with deviter_init() or
   3380  *     deviter_first().
   3381  *
   3382  * deviter_release(di): stops iteration (subsequent calls to
   3383  *     deviter_next() will return NULL), releases any locks and
   3384  *     resources held by the device iterator.
   3385  *
   3386  * Device iteration does not return device_t's in any particular
   3387  * order.  An iterator will never return the same device_t twice.
   3388  * Device iteration is guaranteed to complete---i.e., if deviter_next(di)
   3389  * is called repeatedly on the same `di', it will eventually return
   3390  * NULL.  It is ok to attach/detach devices during device iteration.
   3391  */
   3392 void
   3393 deviter_init(deviter_t *di, deviter_flags_t flags)
   3394 {
   3395 	device_t dv;
   3396 
   3397 	memset(di, 0, sizeof(*di));
   3398 
   3399 	if ((flags & DEVITER_F_SHUTDOWN) != 0)
   3400 		flags |= DEVITER_F_RW;
   3401 
   3402 	mutex_enter(&alldevs_lock);
   3403 	if ((flags & DEVITER_F_RW) != 0)
   3404 		alldevs_nwrite++;
   3405 	else
   3406 		alldevs_nread++;
   3407 	di->di_gen = alldevs_gen++;
   3408 	di->di_flags = flags;
   3409 
   3410 	switch (di->di_flags & (DEVITER_F_LEAVES_FIRST|DEVITER_F_ROOT_FIRST)) {
   3411 	case DEVITER_F_LEAVES_FIRST:
   3412 		TAILQ_FOREACH(dv, &alldevs, dv_list) {
   3413 			if (!deviter_visits(di, dv))
   3414 				continue;
   3415 			di->di_curdepth = MAX(di->di_curdepth, dv->dv_depth);
   3416 		}
   3417 		break;
   3418 	case DEVITER_F_ROOT_FIRST:
   3419 		TAILQ_FOREACH(dv, &alldevs, dv_list) {
   3420 			if (!deviter_visits(di, dv))
   3421 				continue;
   3422 			di->di_maxdepth = MAX(di->di_maxdepth, dv->dv_depth);
   3423 		}
   3424 		break;
   3425 	default:
   3426 		break;
   3427 	}
   3428 
   3429 	deviter_reinit(di);
   3430 	mutex_exit(&alldevs_lock);
   3431 }
   3432 
   3433 static void
   3434 deviter_reinit(deviter_t *di)
   3435 {
   3436 
   3437 	KASSERT(mutex_owned(&alldevs_lock));
   3438 	if ((di->di_flags & DEVITER_F_RW) != 0)
   3439 		di->di_prev = TAILQ_LAST(&alldevs, devicelist);
   3440 	else
   3441 		di->di_prev = TAILQ_FIRST(&alldevs);
   3442 }
   3443 
   3444 device_t
   3445 deviter_first(deviter_t *di, deviter_flags_t flags)
   3446 {
   3447 
   3448 	deviter_init(di, flags);
   3449 	return deviter_next(di);
   3450 }
   3451 
   3452 static device_t
   3453 deviter_next2(deviter_t *di)
   3454 {
   3455 	device_t dv;
   3456 
   3457 	KASSERT(mutex_owned(&alldevs_lock));
   3458 
   3459 	dv = di->di_prev;
   3460 
   3461 	if (dv == NULL)
   3462 		return NULL;
   3463 
   3464 	if ((di->di_flags & DEVITER_F_RW) != 0)
   3465 		di->di_prev = TAILQ_PREV(dv, devicelist, dv_list);
   3466 	else
   3467 		di->di_prev = TAILQ_NEXT(dv, dv_list);
   3468 
   3469 	return dv;
   3470 }
   3471 
   3472 static device_t
   3473 deviter_next1(deviter_t *di)
   3474 {
   3475 	device_t dv;
   3476 
   3477 	KASSERT(mutex_owned(&alldevs_lock));
   3478 
   3479 	do {
   3480 		dv = deviter_next2(di);
   3481 	} while (dv != NULL && !deviter_visits(di, dv));
   3482 
   3483 	return dv;
   3484 }
   3485 
   3486 device_t
   3487 deviter_next(deviter_t *di)
   3488 {
   3489 	device_t dv = NULL;
   3490 
   3491 	mutex_enter(&alldevs_lock);
   3492 	switch (di->di_flags & (DEVITER_F_LEAVES_FIRST|DEVITER_F_ROOT_FIRST)) {
   3493 	case 0:
   3494 		dv = deviter_next1(di);
   3495 		break;
   3496 	case DEVITER_F_LEAVES_FIRST:
   3497 		while (di->di_curdepth >= 0) {
   3498 			if ((dv = deviter_next1(di)) == NULL) {
   3499 				di->di_curdepth--;
   3500 				deviter_reinit(di);
   3501 			} else if (dv->dv_depth == di->di_curdepth)
   3502 				break;
   3503 		}
   3504 		break;
   3505 	case DEVITER_F_ROOT_FIRST:
   3506 		while (di->di_curdepth <= di->di_maxdepth) {
   3507 			if ((dv = deviter_next1(di)) == NULL) {
   3508 				di->di_curdepth++;
   3509 				deviter_reinit(di);
   3510 			} else if (dv->dv_depth == di->di_curdepth)
   3511 				break;
   3512 		}
   3513 		break;
   3514 	default:
   3515 		break;
   3516 	}
   3517 	mutex_exit(&alldevs_lock);
   3518 
   3519 	return dv;
   3520 }
   3521 
   3522 void
   3523 deviter_release(deviter_t *di)
   3524 {
   3525 	bool rw = (di->di_flags & DEVITER_F_RW) != 0;
   3526 
   3527 	mutex_enter(&alldevs_lock);
   3528 	if (rw)
   3529 		--alldevs_nwrite;
   3530 	else
   3531 		--alldevs_nread;
   3532 	/* XXX wake a garbage-collection thread */
   3533 	mutex_exit(&alldevs_lock);
   3534 }
   3535 
   3536 const char *
   3537 cfdata_ifattr(const struct cfdata *cf)
   3538 {
   3539 	return cf->cf_pspec->cfp_iattr;
   3540 }
   3541 
   3542 bool
   3543 ifattr_match(const char *snull, const char *t)
   3544 {
   3545 	return (snull == NULL) || strcmp(snull, t) == 0;
   3546 }
   3547 
   3548 void
   3549 null_childdetached(device_t self, device_t child)
   3550 {
   3551 	/* do nothing */
   3552 }
   3553 
   3554 static void
   3555 sysctl_detach_setup(struct sysctllog **clog)
   3556 {
   3557 
   3558 	sysctl_createv(clog, 0, NULL, NULL,
   3559 		CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
   3560 		CTLTYPE_BOOL, "detachall",
   3561 		SYSCTL_DESCR("Detach all devices at shutdown"),
   3562 		NULL, 0, &detachall, 0,
   3563 		CTL_KERN, CTL_CREATE, CTL_EOL);
   3564 }
   3565