xref: /freebsd/sys/kern/subr_bus.c (revision a812392203d7c4c3f0db9d8a0f3391374c49c71f)
1 /*-
2  * Copyright (c) 1997,1998,2003 Doug Rabson
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include "opt_bus.h"
31 #include "opt_random.h"
32 
33 #include <sys/param.h>
34 #include <sys/conf.h>
35 #include <sys/filio.h>
36 #include <sys/lock.h>
37 #include <sys/kernel.h>
38 #include <sys/kobj.h>
39 #include <sys/limits.h>
40 #include <sys/malloc.h>
41 #include <sys/module.h>
42 #include <sys/mutex.h>
43 #include <sys/poll.h>
44 #include <sys/proc.h>
45 #include <sys/condvar.h>
46 #include <sys/queue.h>
47 #include <machine/bus.h>
48 #include <sys/random.h>
49 #include <sys/rman.h>
50 #include <sys/selinfo.h>
51 #include <sys/signalvar.h>
52 #include <sys/sysctl.h>
53 #include <sys/systm.h>
54 #include <sys/uio.h>
55 #include <sys/bus.h>
56 #include <sys/interrupt.h>
57 #include <sys/cpuset.h>
58 
59 #include <net/vnet.h>
60 
61 #include <machine/cpu.h>
62 #include <machine/stdarg.h>
63 
64 #include <vm/uma.h>
65 
66 SYSCTL_NODE(_hw, OID_AUTO, bus, CTLFLAG_RW, NULL, NULL);
67 SYSCTL_ROOT_NODE(OID_AUTO, dev, CTLFLAG_RW, NULL, NULL);
68 
69 /*
70  * Used to attach drivers to devclasses.
71  */
72 typedef struct driverlink *driverlink_t;
73 struct driverlink {
74 	kobj_class_t	driver;
75 	TAILQ_ENTRY(driverlink) link;	/* list of drivers in devclass */
76 	int		pass;
77 	TAILQ_ENTRY(driverlink) passlink;
78 };
79 
80 /*
81  * Forward declarations
82  */
83 typedef TAILQ_HEAD(devclass_list, devclass) devclass_list_t;
84 typedef TAILQ_HEAD(driver_list, driverlink) driver_list_t;
85 typedef TAILQ_HEAD(device_list, device) device_list_t;
86 
87 struct devclass {
88 	TAILQ_ENTRY(devclass) link;
89 	devclass_t	parent;		/* parent in devclass hierarchy */
90 	driver_list_t	drivers;     /* bus devclasses store drivers for bus */
91 	char		*name;
92 	device_t	*devices;	/* array of devices indexed by unit */
93 	int		maxunit;	/* size of devices array */
94 	int		flags;
95 #define DC_HAS_CHILDREN		1
96 
97 	struct sysctl_ctx_list sysctl_ctx;
98 	struct sysctl_oid *sysctl_tree;
99 };
100 
101 /**
102  * @brief Implementation of device.
103  */
104 struct device {
105 	/*
106 	 * A device is a kernel object. The first field must be the
107 	 * current ops table for the object.
108 	 */
109 	KOBJ_FIELDS;
110 
111 	/*
112 	 * Device hierarchy.
113 	 */
114 	TAILQ_ENTRY(device)	link;	/**< list of devices in parent */
115 	TAILQ_ENTRY(device)	devlink; /**< global device list membership */
116 	device_t	parent;		/**< parent of this device  */
117 	device_list_t	children;	/**< list of child devices */
118 
119 	/*
120 	 * Details of this device.
121 	 */
122 	driver_t	*driver;	/**< current driver */
123 	devclass_t	devclass;	/**< current device class */
124 	int		unit;		/**< current unit number */
125 	char*		nameunit;	/**< name+unit e.g. foodev0 */
126 	char*		desc;		/**< driver specific description */
127 	int		busy;		/**< count of calls to device_busy() */
128 	device_state_t	state;		/**< current device state  */
129 	uint32_t	devflags;	/**< api level flags for device_get_flags() */
130 	u_int		flags;		/**< internal device flags  */
131 #define	DF_ENABLED	0x01		/* device should be probed/attached */
132 #define	DF_FIXEDCLASS	0x02		/* devclass specified at create time */
133 #define	DF_WILDCARD	0x04		/* unit was originally wildcard */
134 #define	DF_DESCMALLOCED	0x08		/* description was malloced */
135 #define	DF_QUIET	0x10		/* don't print verbose attach message */
136 #define	DF_DONENOMATCH	0x20		/* don't execute DEVICE_NOMATCH again */
137 #define	DF_EXTERNALSOFTC 0x40		/* softc not allocated by us */
138 #define	DF_REBID	0x80		/* Can rebid after attach */
139 #define	DF_SUSPENDED	0x100		/* Device is suspended. */
140 	u_int	order;			/**< order from device_add_child_ordered() */
141 	void	*ivars;			/**< instance variables  */
142 	void	*softc;			/**< current driver's variables  */
143 
144 	struct sysctl_ctx_list sysctl_ctx; /**< state for sysctl variables  */
145 	struct sysctl_oid *sysctl_tree;	/**< state for sysctl variables */
146 };
147 
148 static MALLOC_DEFINE(M_BUS, "bus", "Bus data structures");
149 static MALLOC_DEFINE(M_BUS_SC, "bus-sc", "Bus data structures, softc");
150 
151 #ifdef BUS_DEBUG
152 
153 static int bus_debug = 1;
154 SYSCTL_INT(_debug, OID_AUTO, bus_debug, CTLFLAG_RWTUN, &bus_debug, 0,
155     "Bus debug level");
156 
157 #define PDEBUG(a)	if (bus_debug) {printf("%s:%d: ", __func__, __LINE__), printf a; printf("\n");}
158 #define DEVICENAME(d)	((d)? device_get_name(d): "no device")
159 #define DRIVERNAME(d)	((d)? d->name : "no driver")
160 #define DEVCLANAME(d)	((d)? d->name : "no devclass")
161 
162 /**
163  * Produce the indenting, indent*2 spaces plus a '.' ahead of that to
164  * prevent syslog from deleting initial spaces
165  */
166 #define indentprintf(p)	do { int iJ; printf("."); for (iJ=0; iJ<indent; iJ++) printf("  "); printf p ; } while (0)
167 
168 static void print_device_short(device_t dev, int indent);
169 static void print_device(device_t dev, int indent);
170 void print_device_tree_short(device_t dev, int indent);
171 void print_device_tree(device_t dev, int indent);
172 static void print_driver_short(driver_t *driver, int indent);
173 static void print_driver(driver_t *driver, int indent);
174 static void print_driver_list(driver_list_t drivers, int indent);
175 static void print_devclass_short(devclass_t dc, int indent);
176 static void print_devclass(devclass_t dc, int indent);
177 void print_devclass_list_short(void);
178 void print_devclass_list(void);
179 
180 #else
181 /* Make the compiler ignore the function calls */
182 #define PDEBUG(a)			/* nop */
183 #define DEVICENAME(d)			/* nop */
184 #define DRIVERNAME(d)			/* nop */
185 #define DEVCLANAME(d)			/* nop */
186 
187 #define print_device_short(d,i)		/* nop */
188 #define print_device(d,i)		/* nop */
189 #define print_device_tree_short(d,i)	/* nop */
190 #define print_device_tree(d,i)		/* nop */
191 #define print_driver_short(d,i)		/* nop */
192 #define print_driver(d,i)		/* nop */
193 #define print_driver_list(d,i)		/* nop */
194 #define print_devclass_short(d,i)	/* nop */
195 #define print_devclass(d,i)		/* nop */
196 #define print_devclass_list_short()	/* nop */
197 #define print_devclass_list()		/* nop */
198 #endif
199 
200 /*
201  * dev sysctl tree
202  */
203 
204 enum {
205 	DEVCLASS_SYSCTL_PARENT,
206 };
207 
208 static int
209 devclass_sysctl_handler(SYSCTL_HANDLER_ARGS)
210 {
211 	devclass_t dc = (devclass_t)arg1;
212 	const char *value;
213 
214 	switch (arg2) {
215 	case DEVCLASS_SYSCTL_PARENT:
216 		value = dc->parent ? dc->parent->name : "";
217 		break;
218 	default:
219 		return (EINVAL);
220 	}
221 	return (SYSCTL_OUT(req, value, strlen(value)));
222 }
223 
224 static void
225 devclass_sysctl_init(devclass_t dc)
226 {
227 
228 	if (dc->sysctl_tree != NULL)
229 		return;
230 	sysctl_ctx_init(&dc->sysctl_ctx);
231 	dc->sysctl_tree = SYSCTL_ADD_NODE(&dc->sysctl_ctx,
232 	    SYSCTL_STATIC_CHILDREN(_dev), OID_AUTO, dc->name,
233 	    CTLFLAG_RD, NULL, "");
234 	SYSCTL_ADD_PROC(&dc->sysctl_ctx, SYSCTL_CHILDREN(dc->sysctl_tree),
235 	    OID_AUTO, "%parent", CTLTYPE_STRING | CTLFLAG_RD,
236 	    dc, DEVCLASS_SYSCTL_PARENT, devclass_sysctl_handler, "A",
237 	    "parent class");
238 }
239 
240 enum {
241 	DEVICE_SYSCTL_DESC,
242 	DEVICE_SYSCTL_DRIVER,
243 	DEVICE_SYSCTL_LOCATION,
244 	DEVICE_SYSCTL_PNPINFO,
245 	DEVICE_SYSCTL_PARENT,
246 };
247 
248 static int
249 device_sysctl_handler(SYSCTL_HANDLER_ARGS)
250 {
251 	device_t dev = (device_t)arg1;
252 	const char *value;
253 	char *buf;
254 	int error;
255 
256 	buf = NULL;
257 	switch (arg2) {
258 	case DEVICE_SYSCTL_DESC:
259 		value = dev->desc ? dev->desc : "";
260 		break;
261 	case DEVICE_SYSCTL_DRIVER:
262 		value = dev->driver ? dev->driver->name : "";
263 		break;
264 	case DEVICE_SYSCTL_LOCATION:
265 		value = buf = malloc(1024, M_BUS, M_WAITOK | M_ZERO);
266 		bus_child_location_str(dev, buf, 1024);
267 		break;
268 	case DEVICE_SYSCTL_PNPINFO:
269 		value = buf = malloc(1024, M_BUS, M_WAITOK | M_ZERO);
270 		bus_child_pnpinfo_str(dev, buf, 1024);
271 		break;
272 	case DEVICE_SYSCTL_PARENT:
273 		value = dev->parent ? dev->parent->nameunit : "";
274 		break;
275 	default:
276 		return (EINVAL);
277 	}
278 	error = SYSCTL_OUT(req, value, strlen(value));
279 	if (buf != NULL)
280 		free(buf, M_BUS);
281 	return (error);
282 }
283 
284 static void
285 device_sysctl_init(device_t dev)
286 {
287 	devclass_t dc = dev->devclass;
288 	int domain;
289 
290 	if (dev->sysctl_tree != NULL)
291 		return;
292 	devclass_sysctl_init(dc);
293 	sysctl_ctx_init(&dev->sysctl_ctx);
294 	dev->sysctl_tree = SYSCTL_ADD_NODE(&dev->sysctl_ctx,
295 	    SYSCTL_CHILDREN(dc->sysctl_tree), OID_AUTO,
296 	    dev->nameunit + strlen(dc->name),
297 	    CTLFLAG_RD, NULL, "");
298 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
299 	    OID_AUTO, "%desc", CTLTYPE_STRING | CTLFLAG_RD,
300 	    dev, DEVICE_SYSCTL_DESC, device_sysctl_handler, "A",
301 	    "device description");
302 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
303 	    OID_AUTO, "%driver", CTLTYPE_STRING | CTLFLAG_RD,
304 	    dev, DEVICE_SYSCTL_DRIVER, device_sysctl_handler, "A",
305 	    "device driver name");
306 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
307 	    OID_AUTO, "%location", CTLTYPE_STRING | CTLFLAG_RD,
308 	    dev, DEVICE_SYSCTL_LOCATION, device_sysctl_handler, "A",
309 	    "device location relative to parent");
310 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
311 	    OID_AUTO, "%pnpinfo", CTLTYPE_STRING | CTLFLAG_RD,
312 	    dev, DEVICE_SYSCTL_PNPINFO, device_sysctl_handler, "A",
313 	    "device identification");
314 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
315 	    OID_AUTO, "%parent", CTLTYPE_STRING | CTLFLAG_RD,
316 	    dev, DEVICE_SYSCTL_PARENT, device_sysctl_handler, "A",
317 	    "parent device");
318 	if (bus_get_domain(dev, &domain) == 0)
319 		SYSCTL_ADD_INT(&dev->sysctl_ctx,
320 		    SYSCTL_CHILDREN(dev->sysctl_tree), OID_AUTO, "%domain",
321 		    CTLFLAG_RD, NULL, domain, "NUMA domain");
322 }
323 
324 static void
325 device_sysctl_update(device_t dev)
326 {
327 	devclass_t dc = dev->devclass;
328 
329 	if (dev->sysctl_tree == NULL)
330 		return;
331 	sysctl_rename_oid(dev->sysctl_tree, dev->nameunit + strlen(dc->name));
332 }
333 
334 static void
335 device_sysctl_fini(device_t dev)
336 {
337 	if (dev->sysctl_tree == NULL)
338 		return;
339 	sysctl_ctx_free(&dev->sysctl_ctx);
340 	dev->sysctl_tree = NULL;
341 }
342 
343 /*
344  * /dev/devctl implementation
345  */
346 
347 /*
348  * This design allows only one reader for /dev/devctl.  This is not desirable
349  * in the long run, but will get a lot of hair out of this implementation.
350  * Maybe we should make this device a clonable device.
351  *
352  * Also note: we specifically do not attach a device to the device_t tree
353  * to avoid potential chicken and egg problems.  One could argue that all
354  * of this belongs to the root node.  One could also further argue that the
355  * sysctl interface that we have not might more properly be an ioctl
356  * interface, but at this stage of the game, I'm not inclined to rock that
357  * boat.
358  *
359  * I'm also not sure that the SIGIO support is done correctly or not, as
360  * I copied it from a driver that had SIGIO support that likely hasn't been
361  * tested since 3.4 or 2.2.8!
362  */
363 
364 /* Deprecated way to adjust queue length */
365 static int sysctl_devctl_disable(SYSCTL_HANDLER_ARGS);
366 SYSCTL_PROC(_hw_bus, OID_AUTO, devctl_disable, CTLTYPE_INT | CTLFLAG_RWTUN |
367     CTLFLAG_MPSAFE, NULL, 0, sysctl_devctl_disable, "I",
368     "devctl disable -- deprecated");
369 
370 #define DEVCTL_DEFAULT_QUEUE_LEN 1000
371 static int sysctl_devctl_queue(SYSCTL_HANDLER_ARGS);
372 static int devctl_queue_length = DEVCTL_DEFAULT_QUEUE_LEN;
373 SYSCTL_PROC(_hw_bus, OID_AUTO, devctl_queue, CTLTYPE_INT | CTLFLAG_RWTUN |
374     CTLFLAG_MPSAFE, NULL, 0, sysctl_devctl_queue, "I", "devctl queue length");
375 
376 static d_open_t		devopen;
377 static d_close_t	devclose;
378 static d_read_t		devread;
379 static d_ioctl_t	devioctl;
380 static d_poll_t		devpoll;
381 static d_kqfilter_t	devkqfilter;
382 
383 static struct cdevsw dev_cdevsw = {
384 	.d_version =	D_VERSION,
385 	.d_open =	devopen,
386 	.d_close =	devclose,
387 	.d_read =	devread,
388 	.d_ioctl =	devioctl,
389 	.d_poll =	devpoll,
390 	.d_kqfilter =	devkqfilter,
391 	.d_name =	"devctl",
392 };
393 
394 struct dev_event_info
395 {
396 	char *dei_data;
397 	TAILQ_ENTRY(dev_event_info) dei_link;
398 };
399 
400 TAILQ_HEAD(devq, dev_event_info);
401 
402 static struct dev_softc
403 {
404 	int	inuse;
405 	int	nonblock;
406 	int	queued;
407 	int	async;
408 	struct mtx mtx;
409 	struct cv cv;
410 	struct selinfo sel;
411 	struct devq devq;
412 	struct sigio *sigio;
413 } devsoftc;
414 
415 static void	filt_devctl_detach(struct knote *kn);
416 static int	filt_devctl_read(struct knote *kn, long hint);
417 
418 struct filterops devctl_rfiltops = {
419 	.f_isfd = 1,
420 	.f_detach = filt_devctl_detach,
421 	.f_event = filt_devctl_read,
422 };
423 
424 static struct cdev *devctl_dev;
425 
426 static void
427 devinit(void)
428 {
429 	devctl_dev = make_dev_credf(MAKEDEV_ETERNAL, &dev_cdevsw, 0, NULL,
430 	    UID_ROOT, GID_WHEEL, 0600, "devctl");
431 	mtx_init(&devsoftc.mtx, "dev mtx", "devd", MTX_DEF);
432 	cv_init(&devsoftc.cv, "dev cv");
433 	TAILQ_INIT(&devsoftc.devq);
434 	knlist_init_mtx(&devsoftc.sel.si_note, &devsoftc.mtx);
435 }
436 
437 static int
438 devopen(struct cdev *dev, int oflags, int devtype, struct thread *td)
439 {
440 
441 	mtx_lock(&devsoftc.mtx);
442 	if (devsoftc.inuse) {
443 		mtx_unlock(&devsoftc.mtx);
444 		return (EBUSY);
445 	}
446 	/* move to init */
447 	devsoftc.inuse = 1;
448 	mtx_unlock(&devsoftc.mtx);
449 	return (0);
450 }
451 
452 static int
453 devclose(struct cdev *dev, int fflag, int devtype, struct thread *td)
454 {
455 
456 	mtx_lock(&devsoftc.mtx);
457 	devsoftc.inuse = 0;
458 	devsoftc.nonblock = 0;
459 	devsoftc.async = 0;
460 	cv_broadcast(&devsoftc.cv);
461 	funsetown(&devsoftc.sigio);
462 	mtx_unlock(&devsoftc.mtx);
463 	return (0);
464 }
465 
466 /*
467  * The read channel for this device is used to report changes to
468  * userland in realtime.  We are required to free the data as well as
469  * the n1 object because we allocate them separately.  Also note that
470  * we return one record at a time.  If you try to read this device a
471  * character at a time, you will lose the rest of the data.  Listening
472  * programs are expected to cope.
473  */
474 static int
475 devread(struct cdev *dev, struct uio *uio, int ioflag)
476 {
477 	struct dev_event_info *n1;
478 	int rv;
479 
480 	mtx_lock(&devsoftc.mtx);
481 	while (TAILQ_EMPTY(&devsoftc.devq)) {
482 		if (devsoftc.nonblock) {
483 			mtx_unlock(&devsoftc.mtx);
484 			return (EAGAIN);
485 		}
486 		rv = cv_wait_sig(&devsoftc.cv, &devsoftc.mtx);
487 		if (rv) {
488 			/*
489 			 * Need to translate ERESTART to EINTR here? -- jake
490 			 */
491 			mtx_unlock(&devsoftc.mtx);
492 			return (rv);
493 		}
494 	}
495 	n1 = TAILQ_FIRST(&devsoftc.devq);
496 	TAILQ_REMOVE(&devsoftc.devq, n1, dei_link);
497 	devsoftc.queued--;
498 	mtx_unlock(&devsoftc.mtx);
499 	rv = uiomove(n1->dei_data, strlen(n1->dei_data), uio);
500 	free(n1->dei_data, M_BUS);
501 	free(n1, M_BUS);
502 	return (rv);
503 }
504 
505 static	int
506 devioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
507 {
508 	switch (cmd) {
509 
510 	case FIONBIO:
511 		if (*(int*)data)
512 			devsoftc.nonblock = 1;
513 		else
514 			devsoftc.nonblock = 0;
515 		return (0);
516 	case FIOASYNC:
517 		if (*(int*)data)
518 			devsoftc.async = 1;
519 		else
520 			devsoftc.async = 0;
521 		return (0);
522 	case FIOSETOWN:
523 		return fsetown(*(int *)data, &devsoftc.sigio);
524 	case FIOGETOWN:
525 		*(int *)data = fgetown(&devsoftc.sigio);
526 		return (0);
527 
528 		/* (un)Support for other fcntl() calls. */
529 	case FIOCLEX:
530 	case FIONCLEX:
531 	case FIONREAD:
532 	default:
533 		break;
534 	}
535 	return (ENOTTY);
536 }
537 
538 static	int
539 devpoll(struct cdev *dev, int events, struct thread *td)
540 {
541 	int	revents = 0;
542 
543 	mtx_lock(&devsoftc.mtx);
544 	if (events & (POLLIN | POLLRDNORM)) {
545 		if (!TAILQ_EMPTY(&devsoftc.devq))
546 			revents = events & (POLLIN | POLLRDNORM);
547 		else
548 			selrecord(td, &devsoftc.sel);
549 	}
550 	mtx_unlock(&devsoftc.mtx);
551 
552 	return (revents);
553 }
554 
555 static int
556 devkqfilter(struct cdev *dev, struct knote *kn)
557 {
558 	int error;
559 
560 	if (kn->kn_filter == EVFILT_READ) {
561 		kn->kn_fop = &devctl_rfiltops;
562 		knlist_add(&devsoftc.sel.si_note, kn, 0);
563 		error = 0;
564 	} else
565 		error = EINVAL;
566 	return (error);
567 }
568 
569 static void
570 filt_devctl_detach(struct knote *kn)
571 {
572 
573 	knlist_remove(&devsoftc.sel.si_note, kn, 0);
574 }
575 
576 static int
577 filt_devctl_read(struct knote *kn, long hint)
578 {
579 	kn->kn_data = devsoftc.queued;
580 	return (kn->kn_data != 0);
581 }
582 
583 /**
584  * @brief Return whether the userland process is running
585  */
586 boolean_t
587 devctl_process_running(void)
588 {
589 	return (devsoftc.inuse == 1);
590 }
591 
592 /**
593  * @brief Queue data to be read from the devctl device
594  *
595  * Generic interface to queue data to the devctl device.  It is
596  * assumed that @p data is properly formatted.  It is further assumed
597  * that @p data is allocated using the M_BUS malloc type.
598  */
599 void
600 devctl_queue_data_f(char *data, int flags)
601 {
602 	struct dev_event_info *n1 = NULL, *n2 = NULL;
603 
604 	if (strlen(data) == 0)
605 		goto out;
606 	if (devctl_queue_length == 0)
607 		goto out;
608 	n1 = malloc(sizeof(*n1), M_BUS, flags);
609 	if (n1 == NULL)
610 		goto out;
611 	n1->dei_data = data;
612 	mtx_lock(&devsoftc.mtx);
613 	if (devctl_queue_length == 0) {
614 		mtx_unlock(&devsoftc.mtx);
615 		free(n1->dei_data, M_BUS);
616 		free(n1, M_BUS);
617 		return;
618 	}
619 	/* Leave at least one spot in the queue... */
620 	while (devsoftc.queued > devctl_queue_length - 1) {
621 		n2 = TAILQ_FIRST(&devsoftc.devq);
622 		TAILQ_REMOVE(&devsoftc.devq, n2, dei_link);
623 		free(n2->dei_data, M_BUS);
624 		free(n2, M_BUS);
625 		devsoftc.queued--;
626 	}
627 	TAILQ_INSERT_TAIL(&devsoftc.devq, n1, dei_link);
628 	devsoftc.queued++;
629 	cv_broadcast(&devsoftc.cv);
630 	KNOTE_LOCKED(&devsoftc.sel.si_note, 0);
631 	mtx_unlock(&devsoftc.mtx);
632 	selwakeup(&devsoftc.sel);
633 	if (devsoftc.async && devsoftc.sigio != NULL)
634 		pgsigio(&devsoftc.sigio, SIGIO, 0);
635 	return;
636 out:
637 	/*
638 	 * We have to free data on all error paths since the caller
639 	 * assumes it will be free'd when this item is dequeued.
640 	 */
641 	free(data, M_BUS);
642 	return;
643 }
644 
645 void
646 devctl_queue_data(char *data)
647 {
648 
649 	devctl_queue_data_f(data, M_NOWAIT);
650 }
651 
652 /**
653  * @brief Send a 'notification' to userland, using standard ways
654  */
655 void
656 devctl_notify_f(const char *system, const char *subsystem, const char *type,
657     const char *data, int flags)
658 {
659 	int len = 0;
660 	char *msg;
661 
662 	if (system == NULL)
663 		return;		/* BOGUS!  Must specify system. */
664 	if (subsystem == NULL)
665 		return;		/* BOGUS!  Must specify subsystem. */
666 	if (type == NULL)
667 		return;		/* BOGUS!  Must specify type. */
668 	len += strlen(" system=") + strlen(system);
669 	len += strlen(" subsystem=") + strlen(subsystem);
670 	len += strlen(" type=") + strlen(type);
671 	/* add in the data message plus newline. */
672 	if (data != NULL)
673 		len += strlen(data);
674 	len += 3;	/* '!', '\n', and NUL */
675 	msg = malloc(len, M_BUS, flags);
676 	if (msg == NULL)
677 		return;		/* Drop it on the floor */
678 	if (data != NULL)
679 		snprintf(msg, len, "!system=%s subsystem=%s type=%s %s\n",
680 		    system, subsystem, type, data);
681 	else
682 		snprintf(msg, len, "!system=%s subsystem=%s type=%s\n",
683 		    system, subsystem, type);
684 	devctl_queue_data_f(msg, flags);
685 }
686 
687 void
688 devctl_notify(const char *system, const char *subsystem, const char *type,
689     const char *data)
690 {
691 
692 	devctl_notify_f(system, subsystem, type, data, M_NOWAIT);
693 }
694 
695 /*
696  * Common routine that tries to make sending messages as easy as possible.
697  * We allocate memory for the data, copy strings into that, but do not
698  * free it unless there's an error.  The dequeue part of the driver should
699  * free the data.  We don't send data when the device is disabled.  We do
700  * send data, even when we have no listeners, because we wish to avoid
701  * races relating to startup and restart of listening applications.
702  *
703  * devaddq is designed to string together the type of event, with the
704  * object of that event, plus the plug and play info and location info
705  * for that event.  This is likely most useful for devices, but less
706  * useful for other consumers of this interface.  Those should use
707  * the devctl_queue_data() interface instead.
708  */
709 static void
710 devaddq(const char *type, const char *what, device_t dev)
711 {
712 	char *data = NULL;
713 	char *loc = NULL;
714 	char *pnp = NULL;
715 	const char *parstr;
716 
717 	if (!devctl_queue_length)/* Rare race, but lost races safely discard */
718 		return;
719 	data = malloc(1024, M_BUS, M_NOWAIT);
720 	if (data == NULL)
721 		goto bad;
722 
723 	/* get the bus specific location of this device */
724 	loc = malloc(1024, M_BUS, M_NOWAIT);
725 	if (loc == NULL)
726 		goto bad;
727 	*loc = '\0';
728 	bus_child_location_str(dev, loc, 1024);
729 
730 	/* Get the bus specific pnp info of this device */
731 	pnp = malloc(1024, M_BUS, M_NOWAIT);
732 	if (pnp == NULL)
733 		goto bad;
734 	*pnp = '\0';
735 	bus_child_pnpinfo_str(dev, pnp, 1024);
736 
737 	/* Get the parent of this device, or / if high enough in the tree. */
738 	if (device_get_parent(dev) == NULL)
739 		parstr = ".";	/* Or '/' ? */
740 	else
741 		parstr = device_get_nameunit(device_get_parent(dev));
742 	/* String it all together. */
743 	snprintf(data, 1024, "%s%s at %s %s on %s\n", type, what, loc, pnp,
744 	  parstr);
745 	free(loc, M_BUS);
746 	free(pnp, M_BUS);
747 	devctl_queue_data(data);
748 	return;
749 bad:
750 	free(pnp, M_BUS);
751 	free(loc, M_BUS);
752 	free(data, M_BUS);
753 	return;
754 }
755 
756 /*
757  * A device was added to the tree.  We are called just after it successfully
758  * attaches (that is, probe and attach success for this device).  No call
759  * is made if a device is merely parented into the tree.  See devnomatch
760  * if probe fails.  If attach fails, no notification is sent (but maybe
761  * we should have a different message for this).
762  */
763 static void
764 devadded(device_t dev)
765 {
766 	devaddq("+", device_get_nameunit(dev), dev);
767 }
768 
769 /*
770  * A device was removed from the tree.  We are called just before this
771  * happens.
772  */
773 static void
774 devremoved(device_t dev)
775 {
776 	devaddq("-", device_get_nameunit(dev), dev);
777 }
778 
779 /*
780  * Called when there's no match for this device.  This is only called
781  * the first time that no match happens, so we don't keep getting this
782  * message.  Should that prove to be undesirable, we can change it.
783  * This is called when all drivers that can attach to a given bus
784  * decline to accept this device.  Other errors may not be detected.
785  */
786 static void
787 devnomatch(device_t dev)
788 {
789 	devaddq("?", "", dev);
790 }
791 
792 static int
793 sysctl_devctl_disable(SYSCTL_HANDLER_ARGS)
794 {
795 	struct dev_event_info *n1;
796 	int dis, error;
797 
798 	dis = (devctl_queue_length == 0);
799 	error = sysctl_handle_int(oidp, &dis, 0, req);
800 	if (error || !req->newptr)
801 		return (error);
802 	if (mtx_initialized(&devsoftc.mtx))
803 		mtx_lock(&devsoftc.mtx);
804 	if (dis) {
805 		while (!TAILQ_EMPTY(&devsoftc.devq)) {
806 			n1 = TAILQ_FIRST(&devsoftc.devq);
807 			TAILQ_REMOVE(&devsoftc.devq, n1, dei_link);
808 			free(n1->dei_data, M_BUS);
809 			free(n1, M_BUS);
810 		}
811 		devsoftc.queued = 0;
812 		devctl_queue_length = 0;
813 	} else {
814 		devctl_queue_length = DEVCTL_DEFAULT_QUEUE_LEN;
815 	}
816 	if (mtx_initialized(&devsoftc.mtx))
817 		mtx_unlock(&devsoftc.mtx);
818 	return (0);
819 }
820 
821 static int
822 sysctl_devctl_queue(SYSCTL_HANDLER_ARGS)
823 {
824 	struct dev_event_info *n1;
825 	int q, error;
826 
827 	q = devctl_queue_length;
828 	error = sysctl_handle_int(oidp, &q, 0, req);
829 	if (error || !req->newptr)
830 		return (error);
831 	if (q < 0)
832 		return (EINVAL);
833 	if (mtx_initialized(&devsoftc.mtx))
834 		mtx_lock(&devsoftc.mtx);
835 	devctl_queue_length = q;
836 	while (devsoftc.queued > devctl_queue_length) {
837 		n1 = TAILQ_FIRST(&devsoftc.devq);
838 		TAILQ_REMOVE(&devsoftc.devq, n1, dei_link);
839 		free(n1->dei_data, M_BUS);
840 		free(n1, M_BUS);
841 		devsoftc.queued--;
842 	}
843 	if (mtx_initialized(&devsoftc.mtx))
844 		mtx_unlock(&devsoftc.mtx);
845 	return (0);
846 }
847 
848 /* End of /dev/devctl code */
849 
850 static TAILQ_HEAD(,device)	bus_data_devices;
851 static int bus_data_generation = 1;
852 
853 static kobj_method_t null_methods[] = {
854 	KOBJMETHOD_END
855 };
856 
857 DEFINE_CLASS(null, null_methods, 0);
858 
859 /*
860  * Bus pass implementation
861  */
862 
863 static driver_list_t passes = TAILQ_HEAD_INITIALIZER(passes);
864 int bus_current_pass = BUS_PASS_ROOT;
865 
866 /**
867  * @internal
868  * @brief Register the pass level of a new driver attachment
869  *
870  * Register a new driver attachment's pass level.  If no driver
871  * attachment with the same pass level has been added, then @p new
872  * will be added to the global passes list.
873  *
874  * @param new		the new driver attachment
875  */
876 static void
877 driver_register_pass(struct driverlink *new)
878 {
879 	struct driverlink *dl;
880 
881 	/* We only consider pass numbers during boot. */
882 	if (bus_current_pass == BUS_PASS_DEFAULT)
883 		return;
884 
885 	/*
886 	 * Walk the passes list.  If we already know about this pass
887 	 * then there is nothing to do.  If we don't, then insert this
888 	 * driver link into the list.
889 	 */
890 	TAILQ_FOREACH(dl, &passes, passlink) {
891 		if (dl->pass < new->pass)
892 			continue;
893 		if (dl->pass == new->pass)
894 			return;
895 		TAILQ_INSERT_BEFORE(dl, new, passlink);
896 		return;
897 	}
898 	TAILQ_INSERT_TAIL(&passes, new, passlink);
899 }
900 
901 /**
902  * @brief Raise the current bus pass
903  *
904  * Raise the current bus pass level to @p pass.  Call the BUS_NEW_PASS()
905  * method on the root bus to kick off a new device tree scan for each
906  * new pass level that has at least one driver.
907  */
908 void
909 bus_set_pass(int pass)
910 {
911 	struct driverlink *dl;
912 
913 	if (bus_current_pass > pass)
914 		panic("Attempt to lower bus pass level");
915 
916 	TAILQ_FOREACH(dl, &passes, passlink) {
917 		/* Skip pass values below the current pass level. */
918 		if (dl->pass <= bus_current_pass)
919 			continue;
920 
921 		/*
922 		 * Bail once we hit a driver with a pass level that is
923 		 * too high.
924 		 */
925 		if (dl->pass > pass)
926 			break;
927 
928 		/*
929 		 * Raise the pass level to the next level and rescan
930 		 * the tree.
931 		 */
932 		bus_current_pass = dl->pass;
933 		BUS_NEW_PASS(root_bus);
934 	}
935 
936 	/*
937 	 * If there isn't a driver registered for the requested pass,
938 	 * then bus_current_pass might still be less than 'pass'.  Set
939 	 * it to 'pass' in that case.
940 	 */
941 	if (bus_current_pass < pass)
942 		bus_current_pass = pass;
943 	KASSERT(bus_current_pass == pass, ("Failed to update bus pass level"));
944 }
945 
946 /*
947  * Devclass implementation
948  */
949 
950 static devclass_list_t devclasses = TAILQ_HEAD_INITIALIZER(devclasses);
951 
952 /**
953  * @internal
954  * @brief Find or create a device class
955  *
956  * If a device class with the name @p classname exists, return it,
957  * otherwise if @p create is non-zero create and return a new device
958  * class.
959  *
960  * If @p parentname is non-NULL, the parent of the devclass is set to
961  * the devclass of that name.
962  *
963  * @param classname	the devclass name to find or create
964  * @param parentname	the parent devclass name or @c NULL
965  * @param create	non-zero to create a devclass
966  */
967 static devclass_t
968 devclass_find_internal(const char *classname, const char *parentname,
969 		       int create)
970 {
971 	devclass_t dc;
972 
973 	PDEBUG(("looking for %s", classname));
974 	if (!classname)
975 		return (NULL);
976 
977 	TAILQ_FOREACH(dc, &devclasses, link) {
978 		if (!strcmp(dc->name, classname))
979 			break;
980 	}
981 
982 	if (create && !dc) {
983 		PDEBUG(("creating %s", classname));
984 		dc = malloc(sizeof(struct devclass) + strlen(classname) + 1,
985 		    M_BUS, M_NOWAIT | M_ZERO);
986 		if (!dc)
987 			return (NULL);
988 		dc->parent = NULL;
989 		dc->name = (char*) (dc + 1);
990 		strcpy(dc->name, classname);
991 		TAILQ_INIT(&dc->drivers);
992 		TAILQ_INSERT_TAIL(&devclasses, dc, link);
993 
994 		bus_data_generation_update();
995 	}
996 
997 	/*
998 	 * If a parent class is specified, then set that as our parent so
999 	 * that this devclass will support drivers for the parent class as
1000 	 * well.  If the parent class has the same name don't do this though
1001 	 * as it creates a cycle that can trigger an infinite loop in
1002 	 * device_probe_child() if a device exists for which there is no
1003 	 * suitable driver.
1004 	 */
1005 	if (parentname && dc && !dc->parent &&
1006 	    strcmp(classname, parentname) != 0) {
1007 		dc->parent = devclass_find_internal(parentname, NULL, TRUE);
1008 		dc->parent->flags |= DC_HAS_CHILDREN;
1009 	}
1010 
1011 	return (dc);
1012 }
1013 
1014 /**
1015  * @brief Create a device class
1016  *
1017  * If a device class with the name @p classname exists, return it,
1018  * otherwise create and return a new device class.
1019  *
1020  * @param classname	the devclass name to find or create
1021  */
1022 devclass_t
1023 devclass_create(const char *classname)
1024 {
1025 	return (devclass_find_internal(classname, NULL, TRUE));
1026 }
1027 
1028 /**
1029  * @brief Find a device class
1030  *
1031  * If a device class with the name @p classname exists, return it,
1032  * otherwise return @c NULL.
1033  *
1034  * @param classname	the devclass name to find
1035  */
1036 devclass_t
1037 devclass_find(const char *classname)
1038 {
1039 	return (devclass_find_internal(classname, NULL, FALSE));
1040 }
1041 
1042 /**
1043  * @brief Register that a device driver has been added to a devclass
1044  *
1045  * Register that a device driver has been added to a devclass.  This
1046  * is called by devclass_add_driver to accomplish the recursive
1047  * notification of all the children classes of dc, as well as dc.
1048  * Each layer will have BUS_DRIVER_ADDED() called for all instances of
1049  * the devclass.
1050  *
1051  * We do a full search here of the devclass list at each iteration
1052  * level to save storing children-lists in the devclass structure.  If
1053  * we ever move beyond a few dozen devices doing this, we may need to
1054  * reevaluate...
1055  *
1056  * @param dc		the devclass to edit
1057  * @param driver	the driver that was just added
1058  */
1059 static void
1060 devclass_driver_added(devclass_t dc, driver_t *driver)
1061 {
1062 	devclass_t parent;
1063 	int i;
1064 
1065 	/*
1066 	 * Call BUS_DRIVER_ADDED for any existing busses in this class.
1067 	 */
1068 	for (i = 0; i < dc->maxunit; i++)
1069 		if (dc->devices[i] && device_is_attached(dc->devices[i]))
1070 			BUS_DRIVER_ADDED(dc->devices[i], driver);
1071 
1072 	/*
1073 	 * Walk through the children classes.  Since we only keep a
1074 	 * single parent pointer around, we walk the entire list of
1075 	 * devclasses looking for children.  We set the
1076 	 * DC_HAS_CHILDREN flag when a child devclass is created on
1077 	 * the parent, so we only walk the list for those devclasses
1078 	 * that have children.
1079 	 */
1080 	if (!(dc->flags & DC_HAS_CHILDREN))
1081 		return;
1082 	parent = dc;
1083 	TAILQ_FOREACH(dc, &devclasses, link) {
1084 		if (dc->parent == parent)
1085 			devclass_driver_added(dc, driver);
1086 	}
1087 }
1088 
1089 /**
1090  * @brief Add a device driver to a device class
1091  *
1092  * Add a device driver to a devclass. This is normally called
1093  * automatically by DRIVER_MODULE(). The BUS_DRIVER_ADDED() method of
1094  * all devices in the devclass will be called to allow them to attempt
1095  * to re-probe any unmatched children.
1096  *
1097  * @param dc		the devclass to edit
1098  * @param driver	the driver to register
1099  */
1100 int
1101 devclass_add_driver(devclass_t dc, driver_t *driver, int pass, devclass_t *dcp)
1102 {
1103 	driverlink_t dl;
1104 	const char *parentname;
1105 
1106 	PDEBUG(("%s", DRIVERNAME(driver)));
1107 
1108 	/* Don't allow invalid pass values. */
1109 	if (pass <= BUS_PASS_ROOT)
1110 		return (EINVAL);
1111 
1112 	dl = malloc(sizeof *dl, M_BUS, M_NOWAIT|M_ZERO);
1113 	if (!dl)
1114 		return (ENOMEM);
1115 
1116 	/*
1117 	 * Compile the driver's methods. Also increase the reference count
1118 	 * so that the class doesn't get freed when the last instance
1119 	 * goes. This means we can safely use static methods and avoids a
1120 	 * double-free in devclass_delete_driver.
1121 	 */
1122 	kobj_class_compile((kobj_class_t) driver);
1123 
1124 	/*
1125 	 * If the driver has any base classes, make the
1126 	 * devclass inherit from the devclass of the driver's
1127 	 * first base class. This will allow the system to
1128 	 * search for drivers in both devclasses for children
1129 	 * of a device using this driver.
1130 	 */
1131 	if (driver->baseclasses)
1132 		parentname = driver->baseclasses[0]->name;
1133 	else
1134 		parentname = NULL;
1135 	*dcp = devclass_find_internal(driver->name, parentname, TRUE);
1136 
1137 	dl->driver = driver;
1138 	TAILQ_INSERT_TAIL(&dc->drivers, dl, link);
1139 	driver->refs++;		/* XXX: kobj_mtx */
1140 	dl->pass = pass;
1141 	driver_register_pass(dl);
1142 
1143 	devclass_driver_added(dc, driver);
1144 	bus_data_generation_update();
1145 	return (0);
1146 }
1147 
1148 /**
1149  * @brief Register that a device driver has been deleted from a devclass
1150  *
1151  * Register that a device driver has been removed from a devclass.
1152  * This is called by devclass_delete_driver to accomplish the
1153  * recursive notification of all the children classes of busclass, as
1154  * well as busclass.  Each layer will attempt to detach the driver
1155  * from any devices that are children of the bus's devclass.  The function
1156  * will return an error if a device fails to detach.
1157  *
1158  * We do a full search here of the devclass list at each iteration
1159  * level to save storing children-lists in the devclass structure.  If
1160  * we ever move beyond a few dozen devices doing this, we may need to
1161  * reevaluate...
1162  *
1163  * @param busclass	the devclass of the parent bus
1164  * @param dc		the devclass of the driver being deleted
1165  * @param driver	the driver being deleted
1166  */
1167 static int
1168 devclass_driver_deleted(devclass_t busclass, devclass_t dc, driver_t *driver)
1169 {
1170 	devclass_t parent;
1171 	device_t dev;
1172 	int error, i;
1173 
1174 	/*
1175 	 * Disassociate from any devices.  We iterate through all the
1176 	 * devices in the devclass of the driver and detach any which are
1177 	 * using the driver and which have a parent in the devclass which
1178 	 * we are deleting from.
1179 	 *
1180 	 * Note that since a driver can be in multiple devclasses, we
1181 	 * should not detach devices which are not children of devices in
1182 	 * the affected devclass.
1183 	 */
1184 	for (i = 0; i < dc->maxunit; i++) {
1185 		if (dc->devices[i]) {
1186 			dev = dc->devices[i];
1187 			if (dev->driver == driver && dev->parent &&
1188 			    dev->parent->devclass == busclass) {
1189 				if ((error = device_detach(dev)) != 0)
1190 					return (error);
1191 				BUS_PROBE_NOMATCH(dev->parent, dev);
1192 				devnomatch(dev);
1193 				dev->flags |= DF_DONENOMATCH;
1194 			}
1195 		}
1196 	}
1197 
1198 	/*
1199 	 * Walk through the children classes.  Since we only keep a
1200 	 * single parent pointer around, we walk the entire list of
1201 	 * devclasses looking for children.  We set the
1202 	 * DC_HAS_CHILDREN flag when a child devclass is created on
1203 	 * the parent, so we only walk the list for those devclasses
1204 	 * that have children.
1205 	 */
1206 	if (!(busclass->flags & DC_HAS_CHILDREN))
1207 		return (0);
1208 	parent = busclass;
1209 	TAILQ_FOREACH(busclass, &devclasses, link) {
1210 		if (busclass->parent == parent) {
1211 			error = devclass_driver_deleted(busclass, dc, driver);
1212 			if (error)
1213 				return (error);
1214 		}
1215 	}
1216 	return (0);
1217 }
1218 
1219 /**
1220  * @brief Delete a device driver from a device class
1221  *
1222  * Delete a device driver from a devclass. This is normally called
1223  * automatically by DRIVER_MODULE().
1224  *
1225  * If the driver is currently attached to any devices,
1226  * devclass_delete_driver() will first attempt to detach from each
1227  * device. If one of the detach calls fails, the driver will not be
1228  * deleted.
1229  *
1230  * @param dc		the devclass to edit
1231  * @param driver	the driver to unregister
1232  */
1233 int
1234 devclass_delete_driver(devclass_t busclass, driver_t *driver)
1235 {
1236 	devclass_t dc = devclass_find(driver->name);
1237 	driverlink_t dl;
1238 	int error;
1239 
1240 	PDEBUG(("%s from devclass %s", driver->name, DEVCLANAME(busclass)));
1241 
1242 	if (!dc)
1243 		return (0);
1244 
1245 	/*
1246 	 * Find the link structure in the bus' list of drivers.
1247 	 */
1248 	TAILQ_FOREACH(dl, &busclass->drivers, link) {
1249 		if (dl->driver == driver)
1250 			break;
1251 	}
1252 
1253 	if (!dl) {
1254 		PDEBUG(("%s not found in %s list", driver->name,
1255 		    busclass->name));
1256 		return (ENOENT);
1257 	}
1258 
1259 	error = devclass_driver_deleted(busclass, dc, driver);
1260 	if (error != 0)
1261 		return (error);
1262 
1263 	TAILQ_REMOVE(&busclass->drivers, dl, link);
1264 	free(dl, M_BUS);
1265 
1266 	/* XXX: kobj_mtx */
1267 	driver->refs--;
1268 	if (driver->refs == 0)
1269 		kobj_class_free((kobj_class_t) driver);
1270 
1271 	bus_data_generation_update();
1272 	return (0);
1273 }
1274 
1275 /**
1276  * @brief Quiesces a set of device drivers from a device class
1277  *
1278  * Quiesce a device driver from a devclass. This is normally called
1279  * automatically by DRIVER_MODULE().
1280  *
1281  * If the driver is currently attached to any devices,
1282  * devclass_quiesece_driver() will first attempt to quiesce each
1283  * device.
1284  *
1285  * @param dc		the devclass to edit
1286  * @param driver	the driver to unregister
1287  */
1288 static int
1289 devclass_quiesce_driver(devclass_t busclass, driver_t *driver)
1290 {
1291 	devclass_t dc = devclass_find(driver->name);
1292 	driverlink_t dl;
1293 	device_t dev;
1294 	int i;
1295 	int error;
1296 
1297 	PDEBUG(("%s from devclass %s", driver->name, DEVCLANAME(busclass)));
1298 
1299 	if (!dc)
1300 		return (0);
1301 
1302 	/*
1303 	 * Find the link structure in the bus' list of drivers.
1304 	 */
1305 	TAILQ_FOREACH(dl, &busclass->drivers, link) {
1306 		if (dl->driver == driver)
1307 			break;
1308 	}
1309 
1310 	if (!dl) {
1311 		PDEBUG(("%s not found in %s list", driver->name,
1312 		    busclass->name));
1313 		return (ENOENT);
1314 	}
1315 
1316 	/*
1317 	 * Quiesce all devices.  We iterate through all the devices in
1318 	 * the devclass of the driver and quiesce any which are using
1319 	 * the driver and which have a parent in the devclass which we
1320 	 * are quiescing.
1321 	 *
1322 	 * Note that since a driver can be in multiple devclasses, we
1323 	 * should not quiesce devices which are not children of
1324 	 * devices in the affected devclass.
1325 	 */
1326 	for (i = 0; i < dc->maxunit; i++) {
1327 		if (dc->devices[i]) {
1328 			dev = dc->devices[i];
1329 			if (dev->driver == driver && dev->parent &&
1330 			    dev->parent->devclass == busclass) {
1331 				if ((error = device_quiesce(dev)) != 0)
1332 					return (error);
1333 			}
1334 		}
1335 	}
1336 
1337 	return (0);
1338 }
1339 
1340 /**
1341  * @internal
1342  */
1343 static driverlink_t
1344 devclass_find_driver_internal(devclass_t dc, const char *classname)
1345 {
1346 	driverlink_t dl;
1347 
1348 	PDEBUG(("%s in devclass %s", classname, DEVCLANAME(dc)));
1349 
1350 	TAILQ_FOREACH(dl, &dc->drivers, link) {
1351 		if (!strcmp(dl->driver->name, classname))
1352 			return (dl);
1353 	}
1354 
1355 	PDEBUG(("not found"));
1356 	return (NULL);
1357 }
1358 
1359 /**
1360  * @brief Return the name of the devclass
1361  */
1362 const char *
1363 devclass_get_name(devclass_t dc)
1364 {
1365 	return (dc->name);
1366 }
1367 
1368 /**
1369  * @brief Find a device given a unit number
1370  *
1371  * @param dc		the devclass to search
1372  * @param unit		the unit number to search for
1373  *
1374  * @returns		the device with the given unit number or @c
1375  *			NULL if there is no such device
1376  */
1377 device_t
1378 devclass_get_device(devclass_t dc, int unit)
1379 {
1380 	if (dc == NULL || unit < 0 || unit >= dc->maxunit)
1381 		return (NULL);
1382 	return (dc->devices[unit]);
1383 }
1384 
1385 /**
1386  * @brief Find the softc field of a device given a unit number
1387  *
1388  * @param dc		the devclass to search
1389  * @param unit		the unit number to search for
1390  *
1391  * @returns		the softc field of the device with the given
1392  *			unit number or @c NULL if there is no such
1393  *			device
1394  */
1395 void *
1396 devclass_get_softc(devclass_t dc, int unit)
1397 {
1398 	device_t dev;
1399 
1400 	dev = devclass_get_device(dc, unit);
1401 	if (!dev)
1402 		return (NULL);
1403 
1404 	return (device_get_softc(dev));
1405 }
1406 
1407 /**
1408  * @brief Get a list of devices in the devclass
1409  *
1410  * An array containing a list of all the devices in the given devclass
1411  * is allocated and returned in @p *devlistp. The number of devices
1412  * in the array is returned in @p *devcountp. The caller should free
1413  * the array using @c free(p, M_TEMP), even if @p *devcountp is 0.
1414  *
1415  * @param dc		the devclass to examine
1416  * @param devlistp	points at location for array pointer return
1417  *			value
1418  * @param devcountp	points at location for array size return value
1419  *
1420  * @retval 0		success
1421  * @retval ENOMEM	the array allocation failed
1422  */
1423 int
1424 devclass_get_devices(devclass_t dc, device_t **devlistp, int *devcountp)
1425 {
1426 	int count, i;
1427 	device_t *list;
1428 
1429 	count = devclass_get_count(dc);
1430 	list = malloc(count * sizeof(device_t), M_TEMP, M_NOWAIT|M_ZERO);
1431 	if (!list)
1432 		return (ENOMEM);
1433 
1434 	count = 0;
1435 	for (i = 0; i < dc->maxunit; i++) {
1436 		if (dc->devices[i]) {
1437 			list[count] = dc->devices[i];
1438 			count++;
1439 		}
1440 	}
1441 
1442 	*devlistp = list;
1443 	*devcountp = count;
1444 
1445 	return (0);
1446 }
1447 
1448 /**
1449  * @brief Get a list of drivers in the devclass
1450  *
1451  * An array containing a list of pointers to all the drivers in the
1452  * given devclass is allocated and returned in @p *listp.  The number
1453  * of drivers in the array is returned in @p *countp. The caller should
1454  * free the array using @c free(p, M_TEMP).
1455  *
1456  * @param dc		the devclass to examine
1457  * @param listp		gives location for array pointer return value
1458  * @param countp	gives location for number of array elements
1459  *			return value
1460  *
1461  * @retval 0		success
1462  * @retval ENOMEM	the array allocation failed
1463  */
1464 int
1465 devclass_get_drivers(devclass_t dc, driver_t ***listp, int *countp)
1466 {
1467 	driverlink_t dl;
1468 	driver_t **list;
1469 	int count;
1470 
1471 	count = 0;
1472 	TAILQ_FOREACH(dl, &dc->drivers, link)
1473 		count++;
1474 	list = malloc(count * sizeof(driver_t *), M_TEMP, M_NOWAIT);
1475 	if (list == NULL)
1476 		return (ENOMEM);
1477 
1478 	count = 0;
1479 	TAILQ_FOREACH(dl, &dc->drivers, link) {
1480 		list[count] = dl->driver;
1481 		count++;
1482 	}
1483 	*listp = list;
1484 	*countp = count;
1485 
1486 	return (0);
1487 }
1488 
1489 /**
1490  * @brief Get the number of devices in a devclass
1491  *
1492  * @param dc		the devclass to examine
1493  */
1494 int
1495 devclass_get_count(devclass_t dc)
1496 {
1497 	int count, i;
1498 
1499 	count = 0;
1500 	for (i = 0; i < dc->maxunit; i++)
1501 		if (dc->devices[i])
1502 			count++;
1503 	return (count);
1504 }
1505 
1506 /**
1507  * @brief Get the maximum unit number used in a devclass
1508  *
1509  * Note that this is one greater than the highest currently-allocated
1510  * unit.  If a null devclass_t is passed in, -1 is returned to indicate
1511  * that not even the devclass has been allocated yet.
1512  *
1513  * @param dc		the devclass to examine
1514  */
1515 int
1516 devclass_get_maxunit(devclass_t dc)
1517 {
1518 	if (dc == NULL)
1519 		return (-1);
1520 	return (dc->maxunit);
1521 }
1522 
1523 /**
1524  * @brief Find a free unit number in a devclass
1525  *
1526  * This function searches for the first unused unit number greater
1527  * that or equal to @p unit.
1528  *
1529  * @param dc		the devclass to examine
1530  * @param unit		the first unit number to check
1531  */
1532 int
1533 devclass_find_free_unit(devclass_t dc, int unit)
1534 {
1535 	if (dc == NULL)
1536 		return (unit);
1537 	while (unit < dc->maxunit && dc->devices[unit] != NULL)
1538 		unit++;
1539 	return (unit);
1540 }
1541 
1542 /**
1543  * @brief Set the parent of a devclass
1544  *
1545  * The parent class is normally initialised automatically by
1546  * DRIVER_MODULE().
1547  *
1548  * @param dc		the devclass to edit
1549  * @param pdc		the new parent devclass
1550  */
1551 void
1552 devclass_set_parent(devclass_t dc, devclass_t pdc)
1553 {
1554 	dc->parent = pdc;
1555 }
1556 
1557 /**
1558  * @brief Get the parent of a devclass
1559  *
1560  * @param dc		the devclass to examine
1561  */
1562 devclass_t
1563 devclass_get_parent(devclass_t dc)
1564 {
1565 	return (dc->parent);
1566 }
1567 
1568 struct sysctl_ctx_list *
1569 devclass_get_sysctl_ctx(devclass_t dc)
1570 {
1571 	return (&dc->sysctl_ctx);
1572 }
1573 
1574 struct sysctl_oid *
1575 devclass_get_sysctl_tree(devclass_t dc)
1576 {
1577 	return (dc->sysctl_tree);
1578 }
1579 
1580 /**
1581  * @internal
1582  * @brief Allocate a unit number
1583  *
1584  * On entry, @p *unitp is the desired unit number (or @c -1 if any
1585  * will do). The allocated unit number is returned in @p *unitp.
1586 
1587  * @param dc		the devclass to allocate from
1588  * @param unitp		points at the location for the allocated unit
1589  *			number
1590  *
1591  * @retval 0		success
1592  * @retval EEXIST	the requested unit number is already allocated
1593  * @retval ENOMEM	memory allocation failure
1594  */
1595 static int
1596 devclass_alloc_unit(devclass_t dc, device_t dev, int *unitp)
1597 {
1598 	const char *s;
1599 	int unit = *unitp;
1600 
1601 	PDEBUG(("unit %d in devclass %s", unit, DEVCLANAME(dc)));
1602 
1603 	/* Ask the parent bus if it wants to wire this device. */
1604 	if (unit == -1)
1605 		BUS_HINT_DEVICE_UNIT(device_get_parent(dev), dev, dc->name,
1606 		    &unit);
1607 
1608 	/* If we were given a wired unit number, check for existing device */
1609 	/* XXX imp XXX */
1610 	if (unit != -1) {
1611 		if (unit >= 0 && unit < dc->maxunit &&
1612 		    dc->devices[unit] != NULL) {
1613 			if (bootverbose)
1614 				printf("%s: %s%d already exists; skipping it\n",
1615 				    dc->name, dc->name, *unitp);
1616 			return (EEXIST);
1617 		}
1618 	} else {
1619 		/* Unwired device, find the next available slot for it */
1620 		unit = 0;
1621 		for (unit = 0;; unit++) {
1622 			/* If there is an "at" hint for a unit then skip it. */
1623 			if (resource_string_value(dc->name, unit, "at", &s) ==
1624 			    0)
1625 				continue;
1626 
1627 			/* If this device slot is already in use, skip it. */
1628 			if (unit < dc->maxunit && dc->devices[unit] != NULL)
1629 				continue;
1630 
1631 			break;
1632 		}
1633 	}
1634 
1635 	/*
1636 	 * We've selected a unit beyond the length of the table, so let's
1637 	 * extend the table to make room for all units up to and including
1638 	 * this one.
1639 	 */
1640 	if (unit >= dc->maxunit) {
1641 		device_t *newlist, *oldlist;
1642 		int newsize;
1643 
1644 		oldlist = dc->devices;
1645 		newsize = roundup((unit + 1), MINALLOCSIZE / sizeof(device_t));
1646 		newlist = malloc(sizeof(device_t) * newsize, M_BUS, M_NOWAIT);
1647 		if (!newlist)
1648 			return (ENOMEM);
1649 		if (oldlist != NULL)
1650 			bcopy(oldlist, newlist, sizeof(device_t) * dc->maxunit);
1651 		bzero(newlist + dc->maxunit,
1652 		    sizeof(device_t) * (newsize - dc->maxunit));
1653 		dc->devices = newlist;
1654 		dc->maxunit = newsize;
1655 		if (oldlist != NULL)
1656 			free(oldlist, M_BUS);
1657 	}
1658 	PDEBUG(("now: unit %d in devclass %s", unit, DEVCLANAME(dc)));
1659 
1660 	*unitp = unit;
1661 	return (0);
1662 }
1663 
1664 /**
1665  * @internal
1666  * @brief Add a device to a devclass
1667  *
1668  * A unit number is allocated for the device (using the device's
1669  * preferred unit number if any) and the device is registered in the
1670  * devclass. This allows the device to be looked up by its unit
1671  * number, e.g. by decoding a dev_t minor number.
1672  *
1673  * @param dc		the devclass to add to
1674  * @param dev		the device to add
1675  *
1676  * @retval 0		success
1677  * @retval EEXIST	the requested unit number is already allocated
1678  * @retval ENOMEM	memory allocation failure
1679  */
1680 static int
1681 devclass_add_device(devclass_t dc, device_t dev)
1682 {
1683 	int buflen, error;
1684 
1685 	PDEBUG(("%s in devclass %s", DEVICENAME(dev), DEVCLANAME(dc)));
1686 
1687 	buflen = snprintf(NULL, 0, "%s%d$", dc->name, INT_MAX);
1688 	if (buflen < 0)
1689 		return (ENOMEM);
1690 	dev->nameunit = malloc(buflen, M_BUS, M_NOWAIT|M_ZERO);
1691 	if (!dev->nameunit)
1692 		return (ENOMEM);
1693 
1694 	if ((error = devclass_alloc_unit(dc, dev, &dev->unit)) != 0) {
1695 		free(dev->nameunit, M_BUS);
1696 		dev->nameunit = NULL;
1697 		return (error);
1698 	}
1699 	dc->devices[dev->unit] = dev;
1700 	dev->devclass = dc;
1701 	snprintf(dev->nameunit, buflen, "%s%d", dc->name, dev->unit);
1702 
1703 	return (0);
1704 }
1705 
1706 /**
1707  * @internal
1708  * @brief Delete a device from a devclass
1709  *
1710  * The device is removed from the devclass's device list and its unit
1711  * number is freed.
1712 
1713  * @param dc		the devclass to delete from
1714  * @param dev		the device to delete
1715  *
1716  * @retval 0		success
1717  */
1718 static int
1719 devclass_delete_device(devclass_t dc, device_t dev)
1720 {
1721 	if (!dc || !dev)
1722 		return (0);
1723 
1724 	PDEBUG(("%s in devclass %s", DEVICENAME(dev), DEVCLANAME(dc)));
1725 
1726 	if (dev->devclass != dc || dc->devices[dev->unit] != dev)
1727 		panic("devclass_delete_device: inconsistent device class");
1728 	dc->devices[dev->unit] = NULL;
1729 	if (dev->flags & DF_WILDCARD)
1730 		dev->unit = -1;
1731 	dev->devclass = NULL;
1732 	free(dev->nameunit, M_BUS);
1733 	dev->nameunit = NULL;
1734 
1735 	return (0);
1736 }
1737 
1738 /**
1739  * @internal
1740  * @brief Make a new device and add it as a child of @p parent
1741  *
1742  * @param parent	the parent of the new device
1743  * @param name		the devclass name of the new device or @c NULL
1744  *			to leave the devclass unspecified
1745  * @parem unit		the unit number of the new device of @c -1 to
1746  *			leave the unit number unspecified
1747  *
1748  * @returns the new device
1749  */
1750 static device_t
1751 make_device(device_t parent, const char *name, int unit)
1752 {
1753 	device_t dev;
1754 	devclass_t dc;
1755 
1756 	PDEBUG(("%s at %s as unit %d", name, DEVICENAME(parent), unit));
1757 
1758 	if (name) {
1759 		dc = devclass_find_internal(name, NULL, TRUE);
1760 		if (!dc) {
1761 			printf("make_device: can't find device class %s\n",
1762 			    name);
1763 			return (NULL);
1764 		}
1765 	} else {
1766 		dc = NULL;
1767 	}
1768 
1769 	dev = malloc(sizeof(struct device), M_BUS, M_NOWAIT|M_ZERO);
1770 	if (!dev)
1771 		return (NULL);
1772 
1773 	dev->parent = parent;
1774 	TAILQ_INIT(&dev->children);
1775 	kobj_init((kobj_t) dev, &null_class);
1776 	dev->driver = NULL;
1777 	dev->devclass = NULL;
1778 	dev->unit = unit;
1779 	dev->nameunit = NULL;
1780 	dev->desc = NULL;
1781 	dev->busy = 0;
1782 	dev->devflags = 0;
1783 	dev->flags = DF_ENABLED;
1784 	dev->order = 0;
1785 	if (unit == -1)
1786 		dev->flags |= DF_WILDCARD;
1787 	if (name) {
1788 		dev->flags |= DF_FIXEDCLASS;
1789 		if (devclass_add_device(dc, dev)) {
1790 			kobj_delete((kobj_t) dev, M_BUS);
1791 			return (NULL);
1792 		}
1793 	}
1794 	dev->ivars = NULL;
1795 	dev->softc = NULL;
1796 
1797 	dev->state = DS_NOTPRESENT;
1798 
1799 	TAILQ_INSERT_TAIL(&bus_data_devices, dev, devlink);
1800 	bus_data_generation_update();
1801 
1802 	return (dev);
1803 }
1804 
1805 /**
1806  * @internal
1807  * @brief Print a description of a device.
1808  */
1809 static int
1810 device_print_child(device_t dev, device_t child)
1811 {
1812 	int retval = 0;
1813 
1814 	if (device_is_alive(child))
1815 		retval += BUS_PRINT_CHILD(dev, child);
1816 	else
1817 		retval += device_printf(child, " not found\n");
1818 
1819 	return (retval);
1820 }
1821 
1822 /**
1823  * @brief Create a new device
1824  *
1825  * This creates a new device and adds it as a child of an existing
1826  * parent device. The new device will be added after the last existing
1827  * child with order zero.
1828  *
1829  * @param dev		the device which will be the parent of the
1830  *			new child device
1831  * @param name		devclass name for new device or @c NULL if not
1832  *			specified
1833  * @param unit		unit number for new device or @c -1 if not
1834  *			specified
1835  *
1836  * @returns		the new device
1837  */
1838 device_t
1839 device_add_child(device_t dev, const char *name, int unit)
1840 {
1841 	return (device_add_child_ordered(dev, 0, name, unit));
1842 }
1843 
1844 /**
1845  * @brief Create a new device
1846  *
1847  * This creates a new device and adds it as a child of an existing
1848  * parent device. The new device will be added after the last existing
1849  * child with the same order.
1850  *
1851  * @param dev		the device which will be the parent of the
1852  *			new child device
1853  * @param order		a value which is used to partially sort the
1854  *			children of @p dev - devices created using
1855  *			lower values of @p order appear first in @p
1856  *			dev's list of children
1857  * @param name		devclass name for new device or @c NULL if not
1858  *			specified
1859  * @param unit		unit number for new device or @c -1 if not
1860  *			specified
1861  *
1862  * @returns		the new device
1863  */
1864 device_t
1865 device_add_child_ordered(device_t dev, u_int order, const char *name, int unit)
1866 {
1867 	device_t child;
1868 	device_t place;
1869 
1870 	PDEBUG(("%s at %s with order %u as unit %d",
1871 	    name, DEVICENAME(dev), order, unit));
1872 	KASSERT(name != NULL || unit == -1,
1873 	    ("child device with wildcard name and specific unit number"));
1874 
1875 	child = make_device(dev, name, unit);
1876 	if (child == NULL)
1877 		return (child);
1878 	child->order = order;
1879 
1880 	TAILQ_FOREACH(place, &dev->children, link) {
1881 		if (place->order > order)
1882 			break;
1883 	}
1884 
1885 	if (place) {
1886 		/*
1887 		 * The device 'place' is the first device whose order is
1888 		 * greater than the new child.
1889 		 */
1890 		TAILQ_INSERT_BEFORE(place, child, link);
1891 	} else {
1892 		/*
1893 		 * The new child's order is greater or equal to the order of
1894 		 * any existing device. Add the child to the tail of the list.
1895 		 */
1896 		TAILQ_INSERT_TAIL(&dev->children, child, link);
1897 	}
1898 
1899 	bus_data_generation_update();
1900 	return (child);
1901 }
1902 
1903 /**
1904  * @brief Delete a device
1905  *
1906  * This function deletes a device along with all of its children. If
1907  * the device currently has a driver attached to it, the device is
1908  * detached first using device_detach().
1909  *
1910  * @param dev		the parent device
1911  * @param child		the device to delete
1912  *
1913  * @retval 0		success
1914  * @retval non-zero	a unit error code describing the error
1915  */
1916 int
1917 device_delete_child(device_t dev, device_t child)
1918 {
1919 	int error;
1920 	device_t grandchild;
1921 
1922 	PDEBUG(("%s from %s", DEVICENAME(child), DEVICENAME(dev)));
1923 
1924 	/* remove children first */
1925 	while ((grandchild = TAILQ_FIRST(&child->children)) != NULL) {
1926 		error = device_delete_child(child, grandchild);
1927 		if (error)
1928 			return (error);
1929 	}
1930 
1931 	if ((error = device_detach(child)) != 0)
1932 		return (error);
1933 	if (child->devclass)
1934 		devclass_delete_device(child->devclass, child);
1935 	if (child->parent)
1936 		BUS_CHILD_DELETED(dev, child);
1937 	TAILQ_REMOVE(&dev->children, child, link);
1938 	TAILQ_REMOVE(&bus_data_devices, child, devlink);
1939 	kobj_delete((kobj_t) child, M_BUS);
1940 
1941 	bus_data_generation_update();
1942 	return (0);
1943 }
1944 
1945 /**
1946  * @brief Delete all children devices of the given device, if any.
1947  *
1948  * This function deletes all children devices of the given device, if
1949  * any, using the device_delete_child() function for each device it
1950  * finds. If a child device cannot be deleted, this function will
1951  * return an error code.
1952  *
1953  * @param dev		the parent device
1954  *
1955  * @retval 0		success
1956  * @retval non-zero	a device would not detach
1957  */
1958 int
1959 device_delete_children(device_t dev)
1960 {
1961 	device_t child;
1962 	int error;
1963 
1964 	PDEBUG(("Deleting all children of %s", DEVICENAME(dev)));
1965 
1966 	error = 0;
1967 
1968 	while ((child = TAILQ_FIRST(&dev->children)) != NULL) {
1969 		error = device_delete_child(dev, child);
1970 		if (error) {
1971 			PDEBUG(("Failed deleting %s", DEVICENAME(child)));
1972 			break;
1973 		}
1974 	}
1975 	return (error);
1976 }
1977 
1978 /**
1979  * @brief Find a device given a unit number
1980  *
1981  * This is similar to devclass_get_devices() but only searches for
1982  * devices which have @p dev as a parent.
1983  *
1984  * @param dev		the parent device to search
1985  * @param unit		the unit number to search for.  If the unit is -1,
1986  *			return the first child of @p dev which has name
1987  *			@p classname (that is, the one with the lowest unit.)
1988  *
1989  * @returns		the device with the given unit number or @c
1990  *			NULL if there is no such device
1991  */
1992 device_t
1993 device_find_child(device_t dev, const char *classname, int unit)
1994 {
1995 	devclass_t dc;
1996 	device_t child;
1997 
1998 	dc = devclass_find(classname);
1999 	if (!dc)
2000 		return (NULL);
2001 
2002 	if (unit != -1) {
2003 		child = devclass_get_device(dc, unit);
2004 		if (child && child->parent == dev)
2005 			return (child);
2006 	} else {
2007 		for (unit = 0; unit < devclass_get_maxunit(dc); unit++) {
2008 			child = devclass_get_device(dc, unit);
2009 			if (child && child->parent == dev)
2010 				return (child);
2011 		}
2012 	}
2013 	return (NULL);
2014 }
2015 
2016 /**
2017  * @internal
2018  */
2019 static driverlink_t
2020 first_matching_driver(devclass_t dc, device_t dev)
2021 {
2022 	if (dev->devclass)
2023 		return (devclass_find_driver_internal(dc, dev->devclass->name));
2024 	return (TAILQ_FIRST(&dc->drivers));
2025 }
2026 
2027 /**
2028  * @internal
2029  */
2030 static driverlink_t
2031 next_matching_driver(devclass_t dc, device_t dev, driverlink_t last)
2032 {
2033 	if (dev->devclass) {
2034 		driverlink_t dl;
2035 		for (dl = TAILQ_NEXT(last, link); dl; dl = TAILQ_NEXT(dl, link))
2036 			if (!strcmp(dev->devclass->name, dl->driver->name))
2037 				return (dl);
2038 		return (NULL);
2039 	}
2040 	return (TAILQ_NEXT(last, link));
2041 }
2042 
2043 /**
2044  * @internal
2045  */
2046 int
2047 device_probe_child(device_t dev, device_t child)
2048 {
2049 	devclass_t dc;
2050 	driverlink_t best = NULL;
2051 	driverlink_t dl;
2052 	int result, pri = 0;
2053 	int hasclass = (child->devclass != NULL);
2054 
2055 	GIANT_REQUIRED;
2056 
2057 	dc = dev->devclass;
2058 	if (!dc)
2059 		panic("device_probe_child: parent device has no devclass");
2060 
2061 	/*
2062 	 * If the state is already probed, then return.  However, don't
2063 	 * return if we can rebid this object.
2064 	 */
2065 	if (child->state == DS_ALIVE && (child->flags & DF_REBID) == 0)
2066 		return (0);
2067 
2068 	for (; dc; dc = dc->parent) {
2069 		for (dl = first_matching_driver(dc, child);
2070 		     dl;
2071 		     dl = next_matching_driver(dc, child, dl)) {
2072 			/* If this driver's pass is too high, then ignore it. */
2073 			if (dl->pass > bus_current_pass)
2074 				continue;
2075 
2076 			PDEBUG(("Trying %s", DRIVERNAME(dl->driver)));
2077 			result = device_set_driver(child, dl->driver);
2078 			if (result == ENOMEM)
2079 				return (result);
2080 			else if (result != 0)
2081 				continue;
2082 			if (!hasclass) {
2083 				if (device_set_devclass(child,
2084 				    dl->driver->name) != 0) {
2085 					char const * devname =
2086 					    device_get_name(child);
2087 					if (devname == NULL)
2088 						devname = "(unknown)";
2089 					printf("driver bug: Unable to set "
2090 					    "devclass (class: %s "
2091 					    "devname: %s)\n",
2092 					    dl->driver->name,
2093 					    devname);
2094 					(void)device_set_driver(child, NULL);
2095 					continue;
2096 				}
2097 			}
2098 
2099 			/* Fetch any flags for the device before probing. */
2100 			resource_int_value(dl->driver->name, child->unit,
2101 			    "flags", &child->devflags);
2102 
2103 			result = DEVICE_PROBE(child);
2104 
2105 			/* Reset flags and devclass before the next probe. */
2106 			child->devflags = 0;
2107 			if (!hasclass)
2108 				(void)device_set_devclass(child, NULL);
2109 
2110 			/*
2111 			 * If the driver returns SUCCESS, there can be
2112 			 * no higher match for this device.
2113 			 */
2114 			if (result == 0) {
2115 				best = dl;
2116 				pri = 0;
2117 				break;
2118 			}
2119 
2120 			/*
2121 			 * The driver returned an error so it
2122 			 * certainly doesn't match.
2123 			 */
2124 			if (result > 0) {
2125 				(void)device_set_driver(child, NULL);
2126 				continue;
2127 			}
2128 
2129 			/*
2130 			 * A priority lower than SUCCESS, remember the
2131 			 * best matching driver. Initialise the value
2132 			 * of pri for the first match.
2133 			 */
2134 			if (best == NULL || result > pri) {
2135 				/*
2136 				 * Probes that return BUS_PROBE_NOWILDCARD
2137 				 * or lower only match on devices whose
2138 				 * driver was explicitly specified.
2139 				 */
2140 				if (result <= BUS_PROBE_NOWILDCARD &&
2141 				    !(child->flags & DF_FIXEDCLASS))
2142 					continue;
2143 				best = dl;
2144 				pri = result;
2145 				continue;
2146 			}
2147 		}
2148 		/*
2149 		 * If we have an unambiguous match in this devclass,
2150 		 * don't look in the parent.
2151 		 */
2152 		if (best && pri == 0)
2153 			break;
2154 	}
2155 
2156 	/*
2157 	 * If we found a driver, change state and initialise the devclass.
2158 	 */
2159 	/* XXX What happens if we rebid and got no best? */
2160 	if (best) {
2161 		/*
2162 		 * If this device was attached, and we were asked to
2163 		 * rescan, and it is a different driver, then we have
2164 		 * to detach the old driver and reattach this new one.
2165 		 * Note, we don't have to check for DF_REBID here
2166 		 * because if the state is > DS_ALIVE, we know it must
2167 		 * be.
2168 		 *
2169 		 * This assumes that all DF_REBID drivers can have
2170 		 * their probe routine called at any time and that
2171 		 * they are idempotent as well as completely benign in
2172 		 * normal operations.
2173 		 *
2174 		 * We also have to make sure that the detach
2175 		 * succeeded, otherwise we fail the operation (or
2176 		 * maybe it should just fail silently?  I'm torn).
2177 		 */
2178 		if (child->state > DS_ALIVE && best->driver != child->driver)
2179 			if ((result = device_detach(dev)) != 0)
2180 				return (result);
2181 
2182 		/* Set the winning driver, devclass, and flags. */
2183 		if (!child->devclass) {
2184 			result = device_set_devclass(child, best->driver->name);
2185 			if (result != 0)
2186 				return (result);
2187 		}
2188 		result = device_set_driver(child, best->driver);
2189 		if (result != 0)
2190 			return (result);
2191 		resource_int_value(best->driver->name, child->unit,
2192 		    "flags", &child->devflags);
2193 
2194 		if (pri < 0) {
2195 			/*
2196 			 * A bit bogus. Call the probe method again to make
2197 			 * sure that we have the right description.
2198 			 */
2199 			DEVICE_PROBE(child);
2200 #if 0
2201 			child->flags |= DF_REBID;
2202 #endif
2203 		} else
2204 			child->flags &= ~DF_REBID;
2205 		child->state = DS_ALIVE;
2206 
2207 		bus_data_generation_update();
2208 		return (0);
2209 	}
2210 
2211 	return (ENXIO);
2212 }
2213 
2214 /**
2215  * @brief Return the parent of a device
2216  */
2217 device_t
2218 device_get_parent(device_t dev)
2219 {
2220 	return (dev->parent);
2221 }
2222 
2223 /**
2224  * @brief Get a list of children of a device
2225  *
2226  * An array containing a list of all the children of the given device
2227  * is allocated and returned in @p *devlistp. The number of devices
2228  * in the array is returned in @p *devcountp. The caller should free
2229  * the array using @c free(p, M_TEMP).
2230  *
2231  * @param dev		the device to examine
2232  * @param devlistp	points at location for array pointer return
2233  *			value
2234  * @param devcountp	points at location for array size return value
2235  *
2236  * @retval 0		success
2237  * @retval ENOMEM	the array allocation failed
2238  */
2239 int
2240 device_get_children(device_t dev, device_t **devlistp, int *devcountp)
2241 {
2242 	int count;
2243 	device_t child;
2244 	device_t *list;
2245 
2246 	count = 0;
2247 	TAILQ_FOREACH(child, &dev->children, link) {
2248 		count++;
2249 	}
2250 	if (count == 0) {
2251 		*devlistp = NULL;
2252 		*devcountp = 0;
2253 		return (0);
2254 	}
2255 
2256 	list = malloc(count * sizeof(device_t), M_TEMP, M_NOWAIT|M_ZERO);
2257 	if (!list)
2258 		return (ENOMEM);
2259 
2260 	count = 0;
2261 	TAILQ_FOREACH(child, &dev->children, link) {
2262 		list[count] = child;
2263 		count++;
2264 	}
2265 
2266 	*devlistp = list;
2267 	*devcountp = count;
2268 
2269 	return (0);
2270 }
2271 
2272 /**
2273  * @brief Return the current driver for the device or @c NULL if there
2274  * is no driver currently attached
2275  */
2276 driver_t *
2277 device_get_driver(device_t dev)
2278 {
2279 	return (dev->driver);
2280 }
2281 
2282 /**
2283  * @brief Return the current devclass for the device or @c NULL if
2284  * there is none.
2285  */
2286 devclass_t
2287 device_get_devclass(device_t dev)
2288 {
2289 	return (dev->devclass);
2290 }
2291 
2292 /**
2293  * @brief Return the name of the device's devclass or @c NULL if there
2294  * is none.
2295  */
2296 const char *
2297 device_get_name(device_t dev)
2298 {
2299 	if (dev != NULL && dev->devclass)
2300 		return (devclass_get_name(dev->devclass));
2301 	return (NULL);
2302 }
2303 
2304 /**
2305  * @brief Return a string containing the device's devclass name
2306  * followed by an ascii representation of the device's unit number
2307  * (e.g. @c "foo2").
2308  */
2309 const char *
2310 device_get_nameunit(device_t dev)
2311 {
2312 	return (dev->nameunit);
2313 }
2314 
2315 /**
2316  * @brief Return the device's unit number.
2317  */
2318 int
2319 device_get_unit(device_t dev)
2320 {
2321 	return (dev->unit);
2322 }
2323 
2324 /**
2325  * @brief Return the device's description string
2326  */
2327 const char *
2328 device_get_desc(device_t dev)
2329 {
2330 	return (dev->desc);
2331 }
2332 
2333 /**
2334  * @brief Return the device's flags
2335  */
2336 uint32_t
2337 device_get_flags(device_t dev)
2338 {
2339 	return (dev->devflags);
2340 }
2341 
2342 struct sysctl_ctx_list *
2343 device_get_sysctl_ctx(device_t dev)
2344 {
2345 	return (&dev->sysctl_ctx);
2346 }
2347 
2348 struct sysctl_oid *
2349 device_get_sysctl_tree(device_t dev)
2350 {
2351 	return (dev->sysctl_tree);
2352 }
2353 
2354 /**
2355  * @brief Print the name of the device followed by a colon and a space
2356  *
2357  * @returns the number of characters printed
2358  */
2359 int
2360 device_print_prettyname(device_t dev)
2361 {
2362 	const char *name = device_get_name(dev);
2363 
2364 	if (name == NULL)
2365 		return (printf("unknown: "));
2366 	return (printf("%s%d: ", name, device_get_unit(dev)));
2367 }
2368 
2369 /**
2370  * @brief Print the name of the device followed by a colon, a space
2371  * and the result of calling vprintf() with the value of @p fmt and
2372  * the following arguments.
2373  *
2374  * @returns the number of characters printed
2375  */
2376 int
2377 device_printf(device_t dev, const char * fmt, ...)
2378 {
2379 	va_list ap;
2380 	int retval;
2381 
2382 	retval = device_print_prettyname(dev);
2383 	va_start(ap, fmt);
2384 	retval += vprintf(fmt, ap);
2385 	va_end(ap);
2386 	return (retval);
2387 }
2388 
2389 /**
2390  * @internal
2391  */
2392 static void
2393 device_set_desc_internal(device_t dev, const char* desc, int copy)
2394 {
2395 	if (dev->desc && (dev->flags & DF_DESCMALLOCED)) {
2396 		free(dev->desc, M_BUS);
2397 		dev->flags &= ~DF_DESCMALLOCED;
2398 		dev->desc = NULL;
2399 	}
2400 
2401 	if (copy && desc) {
2402 		dev->desc = malloc(strlen(desc) + 1, M_BUS, M_NOWAIT);
2403 		if (dev->desc) {
2404 			strcpy(dev->desc, desc);
2405 			dev->flags |= DF_DESCMALLOCED;
2406 		}
2407 	} else {
2408 		/* Avoid a -Wcast-qual warning */
2409 		dev->desc = (char *)(uintptr_t) desc;
2410 	}
2411 
2412 	bus_data_generation_update();
2413 }
2414 
2415 /**
2416  * @brief Set the device's description
2417  *
2418  * The value of @c desc should be a string constant that will not
2419  * change (at least until the description is changed in a subsequent
2420  * call to device_set_desc() or device_set_desc_copy()).
2421  */
2422 void
2423 device_set_desc(device_t dev, const char* desc)
2424 {
2425 	device_set_desc_internal(dev, desc, FALSE);
2426 }
2427 
2428 /**
2429  * @brief Set the device's description
2430  *
2431  * The string pointed to by @c desc is copied. Use this function if
2432  * the device description is generated, (e.g. with sprintf()).
2433  */
2434 void
2435 device_set_desc_copy(device_t dev, const char* desc)
2436 {
2437 	device_set_desc_internal(dev, desc, TRUE);
2438 }
2439 
2440 /**
2441  * @brief Set the device's flags
2442  */
2443 void
2444 device_set_flags(device_t dev, uint32_t flags)
2445 {
2446 	dev->devflags = flags;
2447 }
2448 
2449 /**
2450  * @brief Return the device's softc field
2451  *
2452  * The softc is allocated and zeroed when a driver is attached, based
2453  * on the size field of the driver.
2454  */
2455 void *
2456 device_get_softc(device_t dev)
2457 {
2458 	return (dev->softc);
2459 }
2460 
2461 /**
2462  * @brief Set the device's softc field
2463  *
2464  * Most drivers do not need to use this since the softc is allocated
2465  * automatically when the driver is attached.
2466  */
2467 void
2468 device_set_softc(device_t dev, void *softc)
2469 {
2470 	if (dev->softc && !(dev->flags & DF_EXTERNALSOFTC))
2471 		free(dev->softc, M_BUS_SC);
2472 	dev->softc = softc;
2473 	if (dev->softc)
2474 		dev->flags |= DF_EXTERNALSOFTC;
2475 	else
2476 		dev->flags &= ~DF_EXTERNALSOFTC;
2477 }
2478 
2479 /**
2480  * @brief Free claimed softc
2481  *
2482  * Most drivers do not need to use this since the softc is freed
2483  * automatically when the driver is detached.
2484  */
2485 void
2486 device_free_softc(void *softc)
2487 {
2488 	free(softc, M_BUS_SC);
2489 }
2490 
2491 /**
2492  * @brief Claim softc
2493  *
2494  * This function can be used to let the driver free the automatically
2495  * allocated softc using "device_free_softc()". This function is
2496  * useful when the driver is refcounting the softc and the softc
2497  * cannot be freed when the "device_detach" method is called.
2498  */
2499 void
2500 device_claim_softc(device_t dev)
2501 {
2502 	if (dev->softc)
2503 		dev->flags |= DF_EXTERNALSOFTC;
2504 	else
2505 		dev->flags &= ~DF_EXTERNALSOFTC;
2506 }
2507 
2508 /**
2509  * @brief Get the device's ivars field
2510  *
2511  * The ivars field is used by the parent device to store per-device
2512  * state (e.g. the physical location of the device or a list of
2513  * resources).
2514  */
2515 void *
2516 device_get_ivars(device_t dev)
2517 {
2518 
2519 	KASSERT(dev != NULL, ("device_get_ivars(NULL, ...)"));
2520 	return (dev->ivars);
2521 }
2522 
2523 /**
2524  * @brief Set the device's ivars field
2525  */
2526 void
2527 device_set_ivars(device_t dev, void * ivars)
2528 {
2529 
2530 	KASSERT(dev != NULL, ("device_set_ivars(NULL, ...)"));
2531 	dev->ivars = ivars;
2532 }
2533 
2534 /**
2535  * @brief Return the device's state
2536  */
2537 device_state_t
2538 device_get_state(device_t dev)
2539 {
2540 	return (dev->state);
2541 }
2542 
2543 /**
2544  * @brief Set the DF_ENABLED flag for the device
2545  */
2546 void
2547 device_enable(device_t dev)
2548 {
2549 	dev->flags |= DF_ENABLED;
2550 }
2551 
2552 /**
2553  * @brief Clear the DF_ENABLED flag for the device
2554  */
2555 void
2556 device_disable(device_t dev)
2557 {
2558 	dev->flags &= ~DF_ENABLED;
2559 }
2560 
2561 /**
2562  * @brief Increment the busy counter for the device
2563  */
2564 void
2565 device_busy(device_t dev)
2566 {
2567 	if (dev->state < DS_ATTACHING)
2568 		panic("device_busy: called for unattached device");
2569 	if (dev->busy == 0 && dev->parent)
2570 		device_busy(dev->parent);
2571 	dev->busy++;
2572 	if (dev->state == DS_ATTACHED)
2573 		dev->state = DS_BUSY;
2574 }
2575 
2576 /**
2577  * @brief Decrement the busy counter for the device
2578  */
2579 void
2580 device_unbusy(device_t dev)
2581 {
2582 	if (dev->busy != 0 && dev->state != DS_BUSY &&
2583 	    dev->state != DS_ATTACHING)
2584 		panic("device_unbusy: called for non-busy device %s",
2585 		    device_get_nameunit(dev));
2586 	dev->busy--;
2587 	if (dev->busy == 0) {
2588 		if (dev->parent)
2589 			device_unbusy(dev->parent);
2590 		if (dev->state == DS_BUSY)
2591 			dev->state = DS_ATTACHED;
2592 	}
2593 }
2594 
2595 /**
2596  * @brief Set the DF_QUIET flag for the device
2597  */
2598 void
2599 device_quiet(device_t dev)
2600 {
2601 	dev->flags |= DF_QUIET;
2602 }
2603 
2604 /**
2605  * @brief Clear the DF_QUIET flag for the device
2606  */
2607 void
2608 device_verbose(device_t dev)
2609 {
2610 	dev->flags &= ~DF_QUIET;
2611 }
2612 
2613 /**
2614  * @brief Return non-zero if the DF_QUIET flag is set on the device
2615  */
2616 int
2617 device_is_quiet(device_t dev)
2618 {
2619 	return ((dev->flags & DF_QUIET) != 0);
2620 }
2621 
2622 /**
2623  * @brief Return non-zero if the DF_ENABLED flag is set on the device
2624  */
2625 int
2626 device_is_enabled(device_t dev)
2627 {
2628 	return ((dev->flags & DF_ENABLED) != 0);
2629 }
2630 
2631 /**
2632  * @brief Return non-zero if the device was successfully probed
2633  */
2634 int
2635 device_is_alive(device_t dev)
2636 {
2637 	return (dev->state >= DS_ALIVE);
2638 }
2639 
2640 /**
2641  * @brief Return non-zero if the device currently has a driver
2642  * attached to it
2643  */
2644 int
2645 device_is_attached(device_t dev)
2646 {
2647 	return (dev->state >= DS_ATTACHED);
2648 }
2649 
2650 /**
2651  * @brief Set the devclass of a device
2652  * @see devclass_add_device().
2653  */
2654 int
2655 device_set_devclass(device_t dev, const char *classname)
2656 {
2657 	devclass_t dc;
2658 	int error;
2659 
2660 	if (!classname) {
2661 		if (dev->devclass)
2662 			devclass_delete_device(dev->devclass, dev);
2663 		return (0);
2664 	}
2665 
2666 	if (dev->devclass) {
2667 		printf("device_set_devclass: device class already set\n");
2668 		return (EINVAL);
2669 	}
2670 
2671 	dc = devclass_find_internal(classname, NULL, TRUE);
2672 	if (!dc)
2673 		return (ENOMEM);
2674 
2675 	error = devclass_add_device(dc, dev);
2676 
2677 	bus_data_generation_update();
2678 	return (error);
2679 }
2680 
2681 /**
2682  * @brief Set the driver of a device
2683  *
2684  * @retval 0		success
2685  * @retval EBUSY	the device already has a driver attached
2686  * @retval ENOMEM	a memory allocation failure occurred
2687  */
2688 int
2689 device_set_driver(device_t dev, driver_t *driver)
2690 {
2691 	if (dev->state >= DS_ATTACHED)
2692 		return (EBUSY);
2693 
2694 	if (dev->driver == driver)
2695 		return (0);
2696 
2697 	if (dev->softc && !(dev->flags & DF_EXTERNALSOFTC)) {
2698 		free(dev->softc, M_BUS_SC);
2699 		dev->softc = NULL;
2700 	}
2701 	device_set_desc(dev, NULL);
2702 	kobj_delete((kobj_t) dev, NULL);
2703 	dev->driver = driver;
2704 	if (driver) {
2705 		kobj_init((kobj_t) dev, (kobj_class_t) driver);
2706 		if (!(dev->flags & DF_EXTERNALSOFTC) && driver->size > 0) {
2707 			dev->softc = malloc(driver->size, M_BUS_SC,
2708 			    M_NOWAIT | M_ZERO);
2709 			if (!dev->softc) {
2710 				kobj_delete((kobj_t) dev, NULL);
2711 				kobj_init((kobj_t) dev, &null_class);
2712 				dev->driver = NULL;
2713 				return (ENOMEM);
2714 			}
2715 		}
2716 	} else {
2717 		kobj_init((kobj_t) dev, &null_class);
2718 	}
2719 
2720 	bus_data_generation_update();
2721 	return (0);
2722 }
2723 
2724 /**
2725  * @brief Probe a device, and return this status.
2726  *
2727  * This function is the core of the device autoconfiguration
2728  * system. Its purpose is to select a suitable driver for a device and
2729  * then call that driver to initialise the hardware appropriately. The
2730  * driver is selected by calling the DEVICE_PROBE() method of a set of
2731  * candidate drivers and then choosing the driver which returned the
2732  * best value. This driver is then attached to the device using
2733  * device_attach().
2734  *
2735  * The set of suitable drivers is taken from the list of drivers in
2736  * the parent device's devclass. If the device was originally created
2737  * with a specific class name (see device_add_child()), only drivers
2738  * with that name are probed, otherwise all drivers in the devclass
2739  * are probed. If no drivers return successful probe values in the
2740  * parent devclass, the search continues in the parent of that
2741  * devclass (see devclass_get_parent()) if any.
2742  *
2743  * @param dev		the device to initialise
2744  *
2745  * @retval 0		success
2746  * @retval ENXIO	no driver was found
2747  * @retval ENOMEM	memory allocation failure
2748  * @retval non-zero	some other unix error code
2749  * @retval -1		Device already attached
2750  */
2751 int
2752 device_probe(device_t dev)
2753 {
2754 	int error;
2755 
2756 	GIANT_REQUIRED;
2757 
2758 	if (dev->state >= DS_ALIVE && (dev->flags & DF_REBID) == 0)
2759 		return (-1);
2760 
2761 	if (!(dev->flags & DF_ENABLED)) {
2762 		if (bootverbose && device_get_name(dev) != NULL) {
2763 			device_print_prettyname(dev);
2764 			printf("not probed (disabled)\n");
2765 		}
2766 		return (-1);
2767 	}
2768 	if ((error = device_probe_child(dev->parent, dev)) != 0) {
2769 		if (bus_current_pass == BUS_PASS_DEFAULT &&
2770 		    !(dev->flags & DF_DONENOMATCH)) {
2771 			BUS_PROBE_NOMATCH(dev->parent, dev);
2772 			devnomatch(dev);
2773 			dev->flags |= DF_DONENOMATCH;
2774 		}
2775 		return (error);
2776 	}
2777 	return (0);
2778 }
2779 
2780 /**
2781  * @brief Probe a device and attach a driver if possible
2782  *
2783  * calls device_probe() and attaches if that was successful.
2784  */
2785 int
2786 device_probe_and_attach(device_t dev)
2787 {
2788 	int error;
2789 
2790 	GIANT_REQUIRED;
2791 
2792 	error = device_probe(dev);
2793 	if (error == -1)
2794 		return (0);
2795 	else if (error != 0)
2796 		return (error);
2797 
2798 	CURVNET_SET_QUIET(vnet0);
2799 	error = device_attach(dev);
2800 	CURVNET_RESTORE();
2801 	return error;
2802 }
2803 
2804 /**
2805  * @brief Attach a device driver to a device
2806  *
2807  * This function is a wrapper around the DEVICE_ATTACH() driver
2808  * method. In addition to calling DEVICE_ATTACH(), it initialises the
2809  * device's sysctl tree, optionally prints a description of the device
2810  * and queues a notification event for user-based device management
2811  * services.
2812  *
2813  * Normally this function is only called internally from
2814  * device_probe_and_attach().
2815  *
2816  * @param dev		the device to initialise
2817  *
2818  * @retval 0		success
2819  * @retval ENXIO	no driver was found
2820  * @retval ENOMEM	memory allocation failure
2821  * @retval non-zero	some other unix error code
2822  */
2823 int
2824 device_attach(device_t dev)
2825 {
2826 	uint64_t attachtime;
2827 	int error;
2828 
2829 	if (resource_disabled(dev->driver->name, dev->unit)) {
2830 		device_disable(dev);
2831 		if (bootverbose)
2832 			 device_printf(dev, "disabled via hints entry\n");
2833 		return (ENXIO);
2834 	}
2835 
2836 	device_sysctl_init(dev);
2837 	if (!device_is_quiet(dev))
2838 		device_print_child(dev->parent, dev);
2839 	attachtime = get_cyclecount();
2840 	dev->state = DS_ATTACHING;
2841 	if ((error = DEVICE_ATTACH(dev)) != 0) {
2842 		printf("device_attach: %s%d attach returned %d\n",
2843 		    dev->driver->name, dev->unit, error);
2844 		if (!(dev->flags & DF_FIXEDCLASS))
2845 			devclass_delete_device(dev->devclass, dev);
2846 		(void)device_set_driver(dev, NULL);
2847 		device_sysctl_fini(dev);
2848 		KASSERT(dev->busy == 0, ("attach failed but busy"));
2849 		dev->state = DS_NOTPRESENT;
2850 		return (error);
2851 	}
2852 	attachtime = get_cyclecount() - attachtime;
2853 	/*
2854 	 * 4 bits per device is a reasonable value for desktop and server
2855 	 * hardware with good get_cyclecount() implementations, but may
2856 	 * need to be adjusted on other platforms.
2857 	 */
2858 #ifdef RANDOM_DEBUG
2859 	printf("random: %s(): feeding %d bit(s) of entropy from %s%d\n",
2860 	    __func__, 4, dev->driver->name, dev->unit);
2861 #endif
2862 	random_harvest(&attachtime, sizeof(attachtime), 4, RANDOM_ATTACH);
2863 	device_sysctl_update(dev);
2864 	if (dev->busy)
2865 		dev->state = DS_BUSY;
2866 	else
2867 		dev->state = DS_ATTACHED;
2868 	dev->flags &= ~DF_DONENOMATCH;
2869 	devadded(dev);
2870 	return (0);
2871 }
2872 
2873 /**
2874  * @brief Detach a driver from a device
2875  *
2876  * This function is a wrapper around the DEVICE_DETACH() driver
2877  * method. If the call to DEVICE_DETACH() succeeds, it calls
2878  * BUS_CHILD_DETACHED() for the parent of @p dev, queues a
2879  * notification event for user-based device management services and
2880  * cleans up the device's sysctl tree.
2881  *
2882  * @param dev		the device to un-initialise
2883  *
2884  * @retval 0		success
2885  * @retval ENXIO	no driver was found
2886  * @retval ENOMEM	memory allocation failure
2887  * @retval non-zero	some other unix error code
2888  */
2889 int
2890 device_detach(device_t dev)
2891 {
2892 	int error;
2893 
2894 	GIANT_REQUIRED;
2895 
2896 	PDEBUG(("%s", DEVICENAME(dev)));
2897 	if (dev->state == DS_BUSY)
2898 		return (EBUSY);
2899 	if (dev->state != DS_ATTACHED)
2900 		return (0);
2901 
2902 	if ((error = DEVICE_DETACH(dev)) != 0)
2903 		return (error);
2904 	devremoved(dev);
2905 	if (!device_is_quiet(dev))
2906 		device_printf(dev, "detached\n");
2907 	if (dev->parent)
2908 		BUS_CHILD_DETACHED(dev->parent, dev);
2909 
2910 	if (!(dev->flags & DF_FIXEDCLASS))
2911 		devclass_delete_device(dev->devclass, dev);
2912 
2913 	dev->state = DS_NOTPRESENT;
2914 	(void)device_set_driver(dev, NULL);
2915 	device_sysctl_fini(dev);
2916 
2917 	return (0);
2918 }
2919 
2920 /**
2921  * @brief Tells a driver to quiesce itself.
2922  *
2923  * This function is a wrapper around the DEVICE_QUIESCE() driver
2924  * method. If the call to DEVICE_QUIESCE() succeeds.
2925  *
2926  * @param dev		the device to quiesce
2927  *
2928  * @retval 0		success
2929  * @retval ENXIO	no driver was found
2930  * @retval ENOMEM	memory allocation failure
2931  * @retval non-zero	some other unix error code
2932  */
2933 int
2934 device_quiesce(device_t dev)
2935 {
2936 
2937 	PDEBUG(("%s", DEVICENAME(dev)));
2938 	if (dev->state == DS_BUSY)
2939 		return (EBUSY);
2940 	if (dev->state != DS_ATTACHED)
2941 		return (0);
2942 
2943 	return (DEVICE_QUIESCE(dev));
2944 }
2945 
2946 /**
2947  * @brief Notify a device of system shutdown
2948  *
2949  * This function calls the DEVICE_SHUTDOWN() driver method if the
2950  * device currently has an attached driver.
2951  *
2952  * @returns the value returned by DEVICE_SHUTDOWN()
2953  */
2954 int
2955 device_shutdown(device_t dev)
2956 {
2957 	if (dev->state < DS_ATTACHED)
2958 		return (0);
2959 	return (DEVICE_SHUTDOWN(dev));
2960 }
2961 
2962 /**
2963  * @brief Set the unit number of a device
2964  *
2965  * This function can be used to override the unit number used for a
2966  * device (e.g. to wire a device to a pre-configured unit number).
2967  */
2968 int
2969 device_set_unit(device_t dev, int unit)
2970 {
2971 	devclass_t dc;
2972 	int err;
2973 
2974 	dc = device_get_devclass(dev);
2975 	if (unit < dc->maxunit && dc->devices[unit])
2976 		return (EBUSY);
2977 	err = devclass_delete_device(dc, dev);
2978 	if (err)
2979 		return (err);
2980 	dev->unit = unit;
2981 	err = devclass_add_device(dc, dev);
2982 	if (err)
2983 		return (err);
2984 
2985 	bus_data_generation_update();
2986 	return (0);
2987 }
2988 
2989 /*======================================*/
2990 /*
2991  * Some useful method implementations to make life easier for bus drivers.
2992  */
2993 
2994 /**
2995  * @brief Initialise a resource list.
2996  *
2997  * @param rl		the resource list to initialise
2998  */
2999 void
3000 resource_list_init(struct resource_list *rl)
3001 {
3002 	STAILQ_INIT(rl);
3003 }
3004 
3005 /**
3006  * @brief Reclaim memory used by a resource list.
3007  *
3008  * This function frees the memory for all resource entries on the list
3009  * (if any).
3010  *
3011  * @param rl		the resource list to free
3012  */
3013 void
3014 resource_list_free(struct resource_list *rl)
3015 {
3016 	struct resource_list_entry *rle;
3017 
3018 	while ((rle = STAILQ_FIRST(rl)) != NULL) {
3019 		if (rle->res)
3020 			panic("resource_list_free: resource entry is busy");
3021 		STAILQ_REMOVE_HEAD(rl, link);
3022 		free(rle, M_BUS);
3023 	}
3024 }
3025 
3026 /**
3027  * @brief Add a resource entry.
3028  *
3029  * This function adds a resource entry using the given @p type, @p
3030  * start, @p end and @p count values. A rid value is chosen by
3031  * searching sequentially for the first unused rid starting at zero.
3032  *
3033  * @param rl		the resource list to edit
3034  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
3035  * @param start		the start address of the resource
3036  * @param end		the end address of the resource
3037  * @param count		XXX end-start+1
3038  */
3039 int
3040 resource_list_add_next(struct resource_list *rl, int type, u_long start,
3041     u_long end, u_long count)
3042 {
3043 	int rid;
3044 
3045 	rid = 0;
3046 	while (resource_list_find(rl, type, rid) != NULL)
3047 		rid++;
3048 	resource_list_add(rl, type, rid, start, end, count);
3049 	return (rid);
3050 }
3051 
3052 /**
3053  * @brief Add or modify a resource entry.
3054  *
3055  * If an existing entry exists with the same type and rid, it will be
3056  * modified using the given values of @p start, @p end and @p
3057  * count. If no entry exists, a new one will be created using the
3058  * given values.  The resource list entry that matches is then returned.
3059  *
3060  * @param rl		the resource list to edit
3061  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
3062  * @param rid		the resource identifier
3063  * @param start		the start address of the resource
3064  * @param end		the end address of the resource
3065  * @param count		XXX end-start+1
3066  */
3067 struct resource_list_entry *
3068 resource_list_add(struct resource_list *rl, int type, int rid,
3069     u_long start, u_long end, u_long count)
3070 {
3071 	struct resource_list_entry *rle;
3072 
3073 	rle = resource_list_find(rl, type, rid);
3074 	if (!rle) {
3075 		rle = malloc(sizeof(struct resource_list_entry), M_BUS,
3076 		    M_NOWAIT);
3077 		if (!rle)
3078 			panic("resource_list_add: can't record entry");
3079 		STAILQ_INSERT_TAIL(rl, rle, link);
3080 		rle->type = type;
3081 		rle->rid = rid;
3082 		rle->res = NULL;
3083 		rle->flags = 0;
3084 	}
3085 
3086 	if (rle->res)
3087 		panic("resource_list_add: resource entry is busy");
3088 
3089 	rle->start = start;
3090 	rle->end = end;
3091 	rle->count = count;
3092 	return (rle);
3093 }
3094 
3095 /**
3096  * @brief Determine if a resource entry is busy.
3097  *
3098  * Returns true if a resource entry is busy meaning that it has an
3099  * associated resource that is not an unallocated "reserved" resource.
3100  *
3101  * @param rl		the resource list to search
3102  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
3103  * @param rid		the resource identifier
3104  *
3105  * @returns Non-zero if the entry is busy, zero otherwise.
3106  */
3107 int
3108 resource_list_busy(struct resource_list *rl, int type, int rid)
3109 {
3110 	struct resource_list_entry *rle;
3111 
3112 	rle = resource_list_find(rl, type, rid);
3113 	if (rle == NULL || rle->res == NULL)
3114 		return (0);
3115 	if ((rle->flags & (RLE_RESERVED | RLE_ALLOCATED)) == RLE_RESERVED) {
3116 		KASSERT(!(rman_get_flags(rle->res) & RF_ACTIVE),
3117 		    ("reserved resource is active"));
3118 		return (0);
3119 	}
3120 	return (1);
3121 }
3122 
3123 /**
3124  * @brief Determine if a resource entry is reserved.
3125  *
3126  * Returns true if a resource entry is reserved meaning that it has an
3127  * associated "reserved" resource.  The resource can either be
3128  * allocated or unallocated.
3129  *
3130  * @param rl		the resource list to search
3131  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
3132  * @param rid		the resource identifier
3133  *
3134  * @returns Non-zero if the entry is reserved, zero otherwise.
3135  */
3136 int
3137 resource_list_reserved(struct resource_list *rl, int type, int rid)
3138 {
3139 	struct resource_list_entry *rle;
3140 
3141 	rle = resource_list_find(rl, type, rid);
3142 	if (rle != NULL && rle->flags & RLE_RESERVED)
3143 		return (1);
3144 	return (0);
3145 }
3146 
3147 /**
3148  * @brief Find a resource entry by type and rid.
3149  *
3150  * @param rl		the resource list to search
3151  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
3152  * @param rid		the resource identifier
3153  *
3154  * @returns the resource entry pointer or NULL if there is no such
3155  * entry.
3156  */
3157 struct resource_list_entry *
3158 resource_list_find(struct resource_list *rl, int type, int rid)
3159 {
3160 	struct resource_list_entry *rle;
3161 
3162 	STAILQ_FOREACH(rle, rl, link) {
3163 		if (rle->type == type && rle->rid == rid)
3164 			return (rle);
3165 	}
3166 	return (NULL);
3167 }
3168 
3169 /**
3170  * @brief Delete a resource entry.
3171  *
3172  * @param rl		the resource list to edit
3173  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
3174  * @param rid		the resource identifier
3175  */
3176 void
3177 resource_list_delete(struct resource_list *rl, int type, int rid)
3178 {
3179 	struct resource_list_entry *rle = resource_list_find(rl, type, rid);
3180 
3181 	if (rle) {
3182 		if (rle->res != NULL)
3183 			panic("resource_list_delete: resource has not been released");
3184 		STAILQ_REMOVE(rl, rle, resource_list_entry, link);
3185 		free(rle, M_BUS);
3186 	}
3187 }
3188 
3189 /**
3190  * @brief Allocate a reserved resource
3191  *
3192  * This can be used by busses to force the allocation of resources
3193  * that are always active in the system even if they are not allocated
3194  * by a driver (e.g. PCI BARs).  This function is usually called when
3195  * adding a new child to the bus.  The resource is allocated from the
3196  * parent bus when it is reserved.  The resource list entry is marked
3197  * with RLE_RESERVED to note that it is a reserved resource.
3198  *
3199  * Subsequent attempts to allocate the resource with
3200  * resource_list_alloc() will succeed the first time and will set
3201  * RLE_ALLOCATED to note that it has been allocated.  When a reserved
3202  * resource that has been allocated is released with
3203  * resource_list_release() the resource RLE_ALLOCATED is cleared, but
3204  * the actual resource remains allocated.  The resource can be released to
3205  * the parent bus by calling resource_list_unreserve().
3206  *
3207  * @param rl		the resource list to allocate from
3208  * @param bus		the parent device of @p child
3209  * @param child		the device for which the resource is being reserved
3210  * @param type		the type of resource to allocate
3211  * @param rid		a pointer to the resource identifier
3212  * @param start		hint at the start of the resource range - pass
3213  *			@c 0UL for any start address
3214  * @param end		hint at the end of the resource range - pass
3215  *			@c ~0UL for any end address
3216  * @param count		hint at the size of range required - pass @c 1
3217  *			for any size
3218  * @param flags		any extra flags to control the resource
3219  *			allocation - see @c RF_XXX flags in
3220  *			<sys/rman.h> for details
3221  *
3222  * @returns		the resource which was allocated or @c NULL if no
3223  *			resource could be allocated
3224  */
3225 struct resource *
3226 resource_list_reserve(struct resource_list *rl, device_t bus, device_t child,
3227     int type, int *rid, u_long start, u_long end, u_long count, u_int flags)
3228 {
3229 	struct resource_list_entry *rle = NULL;
3230 	int passthrough = (device_get_parent(child) != bus);
3231 	struct resource *r;
3232 
3233 	if (passthrough)
3234 		panic(
3235     "resource_list_reserve() should only be called for direct children");
3236 	if (flags & RF_ACTIVE)
3237 		panic(
3238     "resource_list_reserve() should only reserve inactive resources");
3239 
3240 	r = resource_list_alloc(rl, bus, child, type, rid, start, end, count,
3241 	    flags);
3242 	if (r != NULL) {
3243 		rle = resource_list_find(rl, type, *rid);
3244 		rle->flags |= RLE_RESERVED;
3245 	}
3246 	return (r);
3247 }
3248 
3249 /**
3250  * @brief Helper function for implementing BUS_ALLOC_RESOURCE()
3251  *
3252  * Implement BUS_ALLOC_RESOURCE() by looking up a resource from the list
3253  * and passing the allocation up to the parent of @p bus. This assumes
3254  * that the first entry of @c device_get_ivars(child) is a struct
3255  * resource_list. This also handles 'passthrough' allocations where a
3256  * child is a remote descendant of bus by passing the allocation up to
3257  * the parent of bus.
3258  *
3259  * Typically, a bus driver would store a list of child resources
3260  * somewhere in the child device's ivars (see device_get_ivars()) and
3261  * its implementation of BUS_ALLOC_RESOURCE() would find that list and
3262  * then call resource_list_alloc() to perform the allocation.
3263  *
3264  * @param rl		the resource list to allocate from
3265  * @param bus		the parent device of @p child
3266  * @param child		the device which is requesting an allocation
3267  * @param type		the type of resource to allocate
3268  * @param rid		a pointer to the resource identifier
3269  * @param start		hint at the start of the resource range - pass
3270  *			@c 0UL for any start address
3271  * @param end		hint at the end of the resource range - pass
3272  *			@c ~0UL for any end address
3273  * @param count		hint at the size of range required - pass @c 1
3274  *			for any size
3275  * @param flags		any extra flags to control the resource
3276  *			allocation - see @c RF_XXX flags in
3277  *			<sys/rman.h> for details
3278  *
3279  * @returns		the resource which was allocated or @c NULL if no
3280  *			resource could be allocated
3281  */
3282 struct resource *
3283 resource_list_alloc(struct resource_list *rl, device_t bus, device_t child,
3284     int type, int *rid, u_long start, u_long end, u_long count, u_int flags)
3285 {
3286 	struct resource_list_entry *rle = NULL;
3287 	int passthrough = (device_get_parent(child) != bus);
3288 	int isdefault = (start == 0UL && end == ~0UL);
3289 
3290 	if (passthrough) {
3291 		return (BUS_ALLOC_RESOURCE(device_get_parent(bus), child,
3292 		    type, rid, start, end, count, flags));
3293 	}
3294 
3295 	rle = resource_list_find(rl, type, *rid);
3296 
3297 	if (!rle)
3298 		return (NULL);		/* no resource of that type/rid */
3299 
3300 	if (rle->res) {
3301 		if (rle->flags & RLE_RESERVED) {
3302 			if (rle->flags & RLE_ALLOCATED)
3303 				return (NULL);
3304 			if ((flags & RF_ACTIVE) &&
3305 			    bus_activate_resource(child, type, *rid,
3306 			    rle->res) != 0)
3307 				return (NULL);
3308 			rle->flags |= RLE_ALLOCATED;
3309 			return (rle->res);
3310 		}
3311 		device_printf(bus,
3312 		    "resource entry %#x type %d for child %s is busy\n", *rid,
3313 		    type, device_get_nameunit(child));
3314 		return (NULL);
3315 	}
3316 
3317 	if (isdefault) {
3318 		start = rle->start;
3319 		count = ulmax(count, rle->count);
3320 		end = ulmax(rle->end, start + count - 1);
3321 	}
3322 
3323 	rle->res = BUS_ALLOC_RESOURCE(device_get_parent(bus), child,
3324 	    type, rid, start, end, count, flags);
3325 
3326 	/*
3327 	 * Record the new range.
3328 	 */
3329 	if (rle->res) {
3330 		rle->start = rman_get_start(rle->res);
3331 		rle->end = rman_get_end(rle->res);
3332 		rle->count = count;
3333 	}
3334 
3335 	return (rle->res);
3336 }
3337 
3338 /**
3339  * @brief Helper function for implementing BUS_RELEASE_RESOURCE()
3340  *
3341  * Implement BUS_RELEASE_RESOURCE() using a resource list. Normally
3342  * used with resource_list_alloc().
3343  *
3344  * @param rl		the resource list which was allocated from
3345  * @param bus		the parent device of @p child
3346  * @param child		the device which is requesting a release
3347  * @param type		the type of resource to release
3348  * @param rid		the resource identifier
3349  * @param res		the resource to release
3350  *
3351  * @retval 0		success
3352  * @retval non-zero	a standard unix error code indicating what
3353  *			error condition prevented the operation
3354  */
3355 int
3356 resource_list_release(struct resource_list *rl, device_t bus, device_t child,
3357     int type, int rid, struct resource *res)
3358 {
3359 	struct resource_list_entry *rle = NULL;
3360 	int passthrough = (device_get_parent(child) != bus);
3361 	int error;
3362 
3363 	if (passthrough) {
3364 		return (BUS_RELEASE_RESOURCE(device_get_parent(bus), child,
3365 		    type, rid, res));
3366 	}
3367 
3368 	rle = resource_list_find(rl, type, rid);
3369 
3370 	if (!rle)
3371 		panic("resource_list_release: can't find resource");
3372 	if (!rle->res)
3373 		panic("resource_list_release: resource entry is not busy");
3374 	if (rle->flags & RLE_RESERVED) {
3375 		if (rle->flags & RLE_ALLOCATED) {
3376 			if (rman_get_flags(res) & RF_ACTIVE) {
3377 				error = bus_deactivate_resource(child, type,
3378 				    rid, res);
3379 				if (error)
3380 					return (error);
3381 			}
3382 			rle->flags &= ~RLE_ALLOCATED;
3383 			return (0);
3384 		}
3385 		return (EINVAL);
3386 	}
3387 
3388 	error = BUS_RELEASE_RESOURCE(device_get_parent(bus), child,
3389 	    type, rid, res);
3390 	if (error)
3391 		return (error);
3392 
3393 	rle->res = NULL;
3394 	return (0);
3395 }
3396 
3397 /**
3398  * @brief Release all active resources of a given type
3399  *
3400  * Release all active resources of a specified type.  This is intended
3401  * to be used to cleanup resources leaked by a driver after detach or
3402  * a failed attach.
3403  *
3404  * @param rl		the resource list which was allocated from
3405  * @param bus		the parent device of @p child
3406  * @param child		the device whose active resources are being released
3407  * @param type		the type of resources to release
3408  *
3409  * @retval 0		success
3410  * @retval EBUSY	at least one resource was active
3411  */
3412 int
3413 resource_list_release_active(struct resource_list *rl, device_t bus,
3414     device_t child, int type)
3415 {
3416 	struct resource_list_entry *rle;
3417 	int error, retval;
3418 
3419 	retval = 0;
3420 	STAILQ_FOREACH(rle, rl, link) {
3421 		if (rle->type != type)
3422 			continue;
3423 		if (rle->res == NULL)
3424 			continue;
3425 		if ((rle->flags & (RLE_RESERVED | RLE_ALLOCATED)) ==
3426 		    RLE_RESERVED)
3427 			continue;
3428 		retval = EBUSY;
3429 		error = resource_list_release(rl, bus, child, type,
3430 		    rman_get_rid(rle->res), rle->res);
3431 		if (error != 0)
3432 			device_printf(bus,
3433 			    "Failed to release active resource: %d\n", error);
3434 	}
3435 	return (retval);
3436 }
3437 
3438 
3439 /**
3440  * @brief Fully release a reserved resource
3441  *
3442  * Fully releases a resource reserved via resource_list_reserve().
3443  *
3444  * @param rl		the resource list which was allocated from
3445  * @param bus		the parent device of @p child
3446  * @param child		the device whose reserved resource is being released
3447  * @param type		the type of resource to release
3448  * @param rid		the resource identifier
3449  * @param res		the resource to release
3450  *
3451  * @retval 0		success
3452  * @retval non-zero	a standard unix error code indicating what
3453  *			error condition prevented the operation
3454  */
3455 int
3456 resource_list_unreserve(struct resource_list *rl, device_t bus, device_t child,
3457     int type, int rid)
3458 {
3459 	struct resource_list_entry *rle = NULL;
3460 	int passthrough = (device_get_parent(child) != bus);
3461 
3462 	if (passthrough)
3463 		panic(
3464     "resource_list_unreserve() should only be called for direct children");
3465 
3466 	rle = resource_list_find(rl, type, rid);
3467 
3468 	if (!rle)
3469 		panic("resource_list_unreserve: can't find resource");
3470 	if (!(rle->flags & RLE_RESERVED))
3471 		return (EINVAL);
3472 	if (rle->flags & RLE_ALLOCATED)
3473 		return (EBUSY);
3474 	rle->flags &= ~RLE_RESERVED;
3475 	return (resource_list_release(rl, bus, child, type, rid, rle->res));
3476 }
3477 
3478 /**
3479  * @brief Print a description of resources in a resource list
3480  *
3481  * Print all resources of a specified type, for use in BUS_PRINT_CHILD().
3482  * The name is printed if at least one resource of the given type is available.
3483  * The format is used to print resource start and end.
3484  *
3485  * @param rl		the resource list to print
3486  * @param name		the name of @p type, e.g. @c "memory"
3487  * @param type		type type of resource entry to print
3488  * @param format	printf(9) format string to print resource
3489  *			start and end values
3490  *
3491  * @returns		the number of characters printed
3492  */
3493 int
3494 resource_list_print_type(struct resource_list *rl, const char *name, int type,
3495     const char *format)
3496 {
3497 	struct resource_list_entry *rle;
3498 	int printed, retval;
3499 
3500 	printed = 0;
3501 	retval = 0;
3502 	/* Yes, this is kinda cheating */
3503 	STAILQ_FOREACH(rle, rl, link) {
3504 		if (rle->type == type) {
3505 			if (printed == 0)
3506 				retval += printf(" %s ", name);
3507 			else
3508 				retval += printf(",");
3509 			printed++;
3510 			retval += printf(format, rle->start);
3511 			if (rle->count > 1) {
3512 				retval += printf("-");
3513 				retval += printf(format, rle->start +
3514 						 rle->count - 1);
3515 			}
3516 		}
3517 	}
3518 	return (retval);
3519 }
3520 
3521 /**
3522  * @brief Releases all the resources in a list.
3523  *
3524  * @param rl		The resource list to purge.
3525  *
3526  * @returns		nothing
3527  */
3528 void
3529 resource_list_purge(struct resource_list *rl)
3530 {
3531 	struct resource_list_entry *rle;
3532 
3533 	while ((rle = STAILQ_FIRST(rl)) != NULL) {
3534 		if (rle->res)
3535 			bus_release_resource(rman_get_device(rle->res),
3536 			    rle->type, rle->rid, rle->res);
3537 		STAILQ_REMOVE_HEAD(rl, link);
3538 		free(rle, M_BUS);
3539 	}
3540 }
3541 
3542 device_t
3543 bus_generic_add_child(device_t dev, u_int order, const char *name, int unit)
3544 {
3545 
3546 	return (device_add_child_ordered(dev, order, name, unit));
3547 }
3548 
3549 /**
3550  * @brief Helper function for implementing DEVICE_PROBE()
3551  *
3552  * This function can be used to help implement the DEVICE_PROBE() for
3553  * a bus (i.e. a device which has other devices attached to it). It
3554  * calls the DEVICE_IDENTIFY() method of each driver in the device's
3555  * devclass.
3556  */
3557 int
3558 bus_generic_probe(device_t dev)
3559 {
3560 	devclass_t dc = dev->devclass;
3561 	driverlink_t dl;
3562 
3563 	TAILQ_FOREACH(dl, &dc->drivers, link) {
3564 		/*
3565 		 * If this driver's pass is too high, then ignore it.
3566 		 * For most drivers in the default pass, this will
3567 		 * never be true.  For early-pass drivers they will
3568 		 * only call the identify routines of eligible drivers
3569 		 * when this routine is called.  Drivers for later
3570 		 * passes should have their identify routines called
3571 		 * on early-pass busses during BUS_NEW_PASS().
3572 		 */
3573 		if (dl->pass > bus_current_pass)
3574 			continue;
3575 		DEVICE_IDENTIFY(dl->driver, dev);
3576 	}
3577 
3578 	return (0);
3579 }
3580 
3581 /**
3582  * @brief Helper function for implementing DEVICE_ATTACH()
3583  *
3584  * This function can be used to help implement the DEVICE_ATTACH() for
3585  * a bus. It calls device_probe_and_attach() for each of the device's
3586  * children.
3587  */
3588 int
3589 bus_generic_attach(device_t dev)
3590 {
3591 	device_t child;
3592 
3593 	TAILQ_FOREACH(child, &dev->children, link) {
3594 		device_probe_and_attach(child);
3595 	}
3596 
3597 	return (0);
3598 }
3599 
3600 /**
3601  * @brief Helper function for implementing DEVICE_DETACH()
3602  *
3603  * This function can be used to help implement the DEVICE_DETACH() for
3604  * a bus. It calls device_detach() for each of the device's
3605  * children.
3606  */
3607 int
3608 bus_generic_detach(device_t dev)
3609 {
3610 	device_t child;
3611 	int error;
3612 
3613 	if (dev->state != DS_ATTACHED)
3614 		return (EBUSY);
3615 
3616 	TAILQ_FOREACH(child, &dev->children, link) {
3617 		if ((error = device_detach(child)) != 0)
3618 			return (error);
3619 	}
3620 
3621 	return (0);
3622 }
3623 
3624 /**
3625  * @brief Helper function for implementing DEVICE_SHUTDOWN()
3626  *
3627  * This function can be used to help implement the DEVICE_SHUTDOWN()
3628  * for a bus. It calls device_shutdown() for each of the device's
3629  * children.
3630  */
3631 int
3632 bus_generic_shutdown(device_t dev)
3633 {
3634 	device_t child;
3635 
3636 	TAILQ_FOREACH(child, &dev->children, link) {
3637 		device_shutdown(child);
3638 	}
3639 
3640 	return (0);
3641 }
3642 
3643 /**
3644  * @brief Default function for suspending a child device.
3645  *
3646  * This function is to be used by a bus's DEVICE_SUSPEND_CHILD().
3647  */
3648 int
3649 bus_generic_suspend_child(device_t dev, device_t child)
3650 {
3651 	int	error;
3652 
3653 	error = DEVICE_SUSPEND(child);
3654 
3655 	if (error == 0)
3656 		dev->flags |= DF_SUSPENDED;
3657 
3658 	return (error);
3659 }
3660 
3661 /**
3662  * @brief Default function for resuming a child device.
3663  *
3664  * This function is to be used by a bus's DEVICE_RESUME_CHILD().
3665  */
3666 int
3667 bus_generic_resume_child(device_t dev, device_t child)
3668 {
3669 
3670 	DEVICE_RESUME(child);
3671 	dev->flags &= ~DF_SUSPENDED;
3672 
3673 	return (0);
3674 }
3675 
3676 /**
3677  * @brief Helper function for implementing DEVICE_SUSPEND()
3678  *
3679  * This function can be used to help implement the DEVICE_SUSPEND()
3680  * for a bus. It calls DEVICE_SUSPEND() for each of the device's
3681  * children. If any call to DEVICE_SUSPEND() fails, the suspend
3682  * operation is aborted and any devices which were suspended are
3683  * resumed immediately by calling their DEVICE_RESUME() methods.
3684  */
3685 int
3686 bus_generic_suspend(device_t dev)
3687 {
3688 	int		error;
3689 	device_t	child, child2;
3690 
3691 	TAILQ_FOREACH(child, &dev->children, link) {
3692 		error = BUS_SUSPEND_CHILD(dev, child);
3693 		if (error) {
3694 			for (child2 = TAILQ_FIRST(&dev->children);
3695 			     child2 && child2 != child;
3696 			     child2 = TAILQ_NEXT(child2, link))
3697 				BUS_RESUME_CHILD(dev, child2);
3698 			return (error);
3699 		}
3700 	}
3701 	return (0);
3702 }
3703 
3704 /**
3705  * @brief Helper function for implementing DEVICE_RESUME()
3706  *
3707  * This function can be used to help implement the DEVICE_RESUME() for
3708  * a bus. It calls DEVICE_RESUME() on each of the device's children.
3709  */
3710 int
3711 bus_generic_resume(device_t dev)
3712 {
3713 	device_t	child;
3714 
3715 	TAILQ_FOREACH(child, &dev->children, link) {
3716 		BUS_RESUME_CHILD(dev, child);
3717 		/* if resume fails, there's nothing we can usefully do... */
3718 	}
3719 	return (0);
3720 }
3721 
3722 /**
3723  * @brief Helper function for implementing BUS_PRINT_CHILD().
3724  *
3725  * This function prints the first part of the ascii representation of
3726  * @p child, including its name, unit and description (if any - see
3727  * device_set_desc()).
3728  *
3729  * @returns the number of characters printed
3730  */
3731 int
3732 bus_print_child_header(device_t dev, device_t child)
3733 {
3734 	int	retval = 0;
3735 
3736 	if (device_get_desc(child)) {
3737 		retval += device_printf(child, "<%s>", device_get_desc(child));
3738 	} else {
3739 		retval += printf("%s", device_get_nameunit(child));
3740 	}
3741 
3742 	return (retval);
3743 }
3744 
3745 /**
3746  * @brief Helper function for implementing BUS_PRINT_CHILD().
3747  *
3748  * This function prints the last part of the ascii representation of
3749  * @p child, which consists of the string @c " on " followed by the
3750  * name and unit of the @p dev.
3751  *
3752  * @returns the number of characters printed
3753  */
3754 int
3755 bus_print_child_footer(device_t dev, device_t child)
3756 {
3757 	return (printf(" on %s\n", device_get_nameunit(dev)));
3758 }
3759 
3760 /**
3761  * @brief Helper function for implementing BUS_PRINT_CHILD().
3762  *
3763  * This function prints out the VM domain for the given device.
3764  *
3765  * @returns the number of characters printed
3766  */
3767 int
3768 bus_print_child_domain(device_t dev, device_t child)
3769 {
3770 	int domain;
3771 
3772 	/* No domain? Don't print anything */
3773 	if (BUS_GET_DOMAIN(dev, child, &domain) != 0)
3774 		return (0);
3775 
3776 	return (printf(" numa-domain %d", domain));
3777 }
3778 
3779 /**
3780  * @brief Helper function for implementing BUS_PRINT_CHILD().
3781  *
3782  * This function simply calls bus_print_child_header() followed by
3783  * bus_print_child_footer().
3784  *
3785  * @returns the number of characters printed
3786  */
3787 int
3788 bus_generic_print_child(device_t dev, device_t child)
3789 {
3790 	int	retval = 0;
3791 
3792 	retval += bus_print_child_header(dev, child);
3793 	retval += bus_print_child_domain(dev, child);
3794 	retval += bus_print_child_footer(dev, child);
3795 
3796 	return (retval);
3797 }
3798 
3799 /**
3800  * @brief Stub function for implementing BUS_READ_IVAR().
3801  *
3802  * @returns ENOENT
3803  */
3804 int
3805 bus_generic_read_ivar(device_t dev, device_t child, int index,
3806     uintptr_t * result)
3807 {
3808 	return (ENOENT);
3809 }
3810 
3811 /**
3812  * @brief Stub function for implementing BUS_WRITE_IVAR().
3813  *
3814  * @returns ENOENT
3815  */
3816 int
3817 bus_generic_write_ivar(device_t dev, device_t child, int index,
3818     uintptr_t value)
3819 {
3820 	return (ENOENT);
3821 }
3822 
3823 /**
3824  * @brief Stub function for implementing BUS_GET_RESOURCE_LIST().
3825  *
3826  * @returns NULL
3827  */
3828 struct resource_list *
3829 bus_generic_get_resource_list(device_t dev, device_t child)
3830 {
3831 	return (NULL);
3832 }
3833 
3834 /**
3835  * @brief Helper function for implementing BUS_DRIVER_ADDED().
3836  *
3837  * This implementation of BUS_DRIVER_ADDED() simply calls the driver's
3838  * DEVICE_IDENTIFY() method to allow it to add new children to the bus
3839  * and then calls device_probe_and_attach() for each unattached child.
3840  */
3841 void
3842 bus_generic_driver_added(device_t dev, driver_t *driver)
3843 {
3844 	device_t child;
3845 
3846 	DEVICE_IDENTIFY(driver, dev);
3847 	TAILQ_FOREACH(child, &dev->children, link) {
3848 		if (child->state == DS_NOTPRESENT ||
3849 		    (child->flags & DF_REBID))
3850 			device_probe_and_attach(child);
3851 	}
3852 }
3853 
3854 /**
3855  * @brief Helper function for implementing BUS_NEW_PASS().
3856  *
3857  * This implementing of BUS_NEW_PASS() first calls the identify
3858  * routines for any drivers that probe at the current pass.  Then it
3859  * walks the list of devices for this bus.  If a device is already
3860  * attached, then it calls BUS_NEW_PASS() on that device.  If the
3861  * device is not already attached, it attempts to attach a driver to
3862  * it.
3863  */
3864 void
3865 bus_generic_new_pass(device_t dev)
3866 {
3867 	driverlink_t dl;
3868 	devclass_t dc;
3869 	device_t child;
3870 
3871 	dc = dev->devclass;
3872 	TAILQ_FOREACH(dl, &dc->drivers, link) {
3873 		if (dl->pass == bus_current_pass)
3874 			DEVICE_IDENTIFY(dl->driver, dev);
3875 	}
3876 	TAILQ_FOREACH(child, &dev->children, link) {
3877 		if (child->state >= DS_ATTACHED)
3878 			BUS_NEW_PASS(child);
3879 		else if (child->state == DS_NOTPRESENT)
3880 			device_probe_and_attach(child);
3881 	}
3882 }
3883 
3884 /**
3885  * @brief Helper function for implementing BUS_SETUP_INTR().
3886  *
3887  * This simple implementation of BUS_SETUP_INTR() simply calls the
3888  * BUS_SETUP_INTR() method of the parent of @p dev.
3889  */
3890 int
3891 bus_generic_setup_intr(device_t dev, device_t child, struct resource *irq,
3892     int flags, driver_filter_t *filter, driver_intr_t *intr, void *arg,
3893     void **cookiep)
3894 {
3895 	/* Propagate up the bus hierarchy until someone handles it. */
3896 	if (dev->parent)
3897 		return (BUS_SETUP_INTR(dev->parent, child, irq, flags,
3898 		    filter, intr, arg, cookiep));
3899 	return (EINVAL);
3900 }
3901 
3902 /**
3903  * @brief Helper function for implementing BUS_TEARDOWN_INTR().
3904  *
3905  * This simple implementation of BUS_TEARDOWN_INTR() simply calls the
3906  * BUS_TEARDOWN_INTR() method of the parent of @p dev.
3907  */
3908 int
3909 bus_generic_teardown_intr(device_t dev, device_t child, struct resource *irq,
3910     void *cookie)
3911 {
3912 	/* Propagate up the bus hierarchy until someone handles it. */
3913 	if (dev->parent)
3914 		return (BUS_TEARDOWN_INTR(dev->parent, child, irq, cookie));
3915 	return (EINVAL);
3916 }
3917 
3918 /**
3919  * @brief Helper function for implementing BUS_ADJUST_RESOURCE().
3920  *
3921  * This simple implementation of BUS_ADJUST_RESOURCE() simply calls the
3922  * BUS_ADJUST_RESOURCE() method of the parent of @p dev.
3923  */
3924 int
3925 bus_generic_adjust_resource(device_t dev, device_t child, int type,
3926     struct resource *r, u_long start, u_long end)
3927 {
3928 	/* Propagate up the bus hierarchy until someone handles it. */
3929 	if (dev->parent)
3930 		return (BUS_ADJUST_RESOURCE(dev->parent, child, type, r, start,
3931 		    end));
3932 	return (EINVAL);
3933 }
3934 
3935 /**
3936  * @brief Helper function for implementing BUS_ALLOC_RESOURCE().
3937  *
3938  * This simple implementation of BUS_ALLOC_RESOURCE() simply calls the
3939  * BUS_ALLOC_RESOURCE() method of the parent of @p dev.
3940  */
3941 struct resource *
3942 bus_generic_alloc_resource(device_t dev, device_t child, int type, int *rid,
3943     u_long start, u_long end, u_long count, u_int flags)
3944 {
3945 	/* Propagate up the bus hierarchy until someone handles it. */
3946 	if (dev->parent)
3947 		return (BUS_ALLOC_RESOURCE(dev->parent, child, type, rid,
3948 		    start, end, count, flags));
3949 	return (NULL);
3950 }
3951 
3952 /**
3953  * @brief Helper function for implementing BUS_RELEASE_RESOURCE().
3954  *
3955  * This simple implementation of BUS_RELEASE_RESOURCE() simply calls the
3956  * BUS_RELEASE_RESOURCE() method of the parent of @p dev.
3957  */
3958 int
3959 bus_generic_release_resource(device_t dev, device_t child, int type, int rid,
3960     struct resource *r)
3961 {
3962 	/* Propagate up the bus hierarchy until someone handles it. */
3963 	if (dev->parent)
3964 		return (BUS_RELEASE_RESOURCE(dev->parent, child, type, rid,
3965 		    r));
3966 	return (EINVAL);
3967 }
3968 
3969 /**
3970  * @brief Helper function for implementing BUS_ACTIVATE_RESOURCE().
3971  *
3972  * This simple implementation of BUS_ACTIVATE_RESOURCE() simply calls the
3973  * BUS_ACTIVATE_RESOURCE() method of the parent of @p dev.
3974  */
3975 int
3976 bus_generic_activate_resource(device_t dev, device_t child, int type, int rid,
3977     struct resource *r)
3978 {
3979 	/* Propagate up the bus hierarchy until someone handles it. */
3980 	if (dev->parent)
3981 		return (BUS_ACTIVATE_RESOURCE(dev->parent, child, type, rid,
3982 		    r));
3983 	return (EINVAL);
3984 }
3985 
3986 /**
3987  * @brief Helper function for implementing BUS_DEACTIVATE_RESOURCE().
3988  *
3989  * This simple implementation of BUS_DEACTIVATE_RESOURCE() simply calls the
3990  * BUS_DEACTIVATE_RESOURCE() method of the parent of @p dev.
3991  */
3992 int
3993 bus_generic_deactivate_resource(device_t dev, device_t child, int type,
3994     int rid, struct resource *r)
3995 {
3996 	/* Propagate up the bus hierarchy until someone handles it. */
3997 	if (dev->parent)
3998 		return (BUS_DEACTIVATE_RESOURCE(dev->parent, child, type, rid,
3999 		    r));
4000 	return (EINVAL);
4001 }
4002 
4003 /**
4004  * @brief Helper function for implementing BUS_BIND_INTR().
4005  *
4006  * This simple implementation of BUS_BIND_INTR() simply calls the
4007  * BUS_BIND_INTR() method of the parent of @p dev.
4008  */
4009 int
4010 bus_generic_bind_intr(device_t dev, device_t child, struct resource *irq,
4011     int cpu)
4012 {
4013 
4014 	/* Propagate up the bus hierarchy until someone handles it. */
4015 	if (dev->parent)
4016 		return (BUS_BIND_INTR(dev->parent, child, irq, cpu));
4017 	return (EINVAL);
4018 }
4019 
4020 /**
4021  * @brief Helper function for implementing BUS_CONFIG_INTR().
4022  *
4023  * This simple implementation of BUS_CONFIG_INTR() simply calls the
4024  * BUS_CONFIG_INTR() method of the parent of @p dev.
4025  */
4026 int
4027 bus_generic_config_intr(device_t dev, int irq, enum intr_trigger trig,
4028     enum intr_polarity pol)
4029 {
4030 
4031 	/* Propagate up the bus hierarchy until someone handles it. */
4032 	if (dev->parent)
4033 		return (BUS_CONFIG_INTR(dev->parent, irq, trig, pol));
4034 	return (EINVAL);
4035 }
4036 
4037 /**
4038  * @brief Helper function for implementing BUS_DESCRIBE_INTR().
4039  *
4040  * This simple implementation of BUS_DESCRIBE_INTR() simply calls the
4041  * BUS_DESCRIBE_INTR() method of the parent of @p dev.
4042  */
4043 int
4044 bus_generic_describe_intr(device_t dev, device_t child, struct resource *irq,
4045     void *cookie, const char *descr)
4046 {
4047 
4048 	/* Propagate up the bus hierarchy until someone handles it. */
4049 	if (dev->parent)
4050 		return (BUS_DESCRIBE_INTR(dev->parent, child, irq, cookie,
4051 		    descr));
4052 	return (EINVAL);
4053 }
4054 
4055 /**
4056  * @brief Helper function for implementing BUS_GET_DMA_TAG().
4057  *
4058  * This simple implementation of BUS_GET_DMA_TAG() simply calls the
4059  * BUS_GET_DMA_TAG() method of the parent of @p dev.
4060  */
4061 bus_dma_tag_t
4062 bus_generic_get_dma_tag(device_t dev, device_t child)
4063 {
4064 
4065 	/* Propagate up the bus hierarchy until someone handles it. */
4066 	if (dev->parent != NULL)
4067 		return (BUS_GET_DMA_TAG(dev->parent, child));
4068 	return (NULL);
4069 }
4070 
4071 /**
4072  * @brief Helper function for implementing BUS_GET_RESOURCE().
4073  *
4074  * This implementation of BUS_GET_RESOURCE() uses the
4075  * resource_list_find() function to do most of the work. It calls
4076  * BUS_GET_RESOURCE_LIST() to find a suitable resource list to
4077  * search.
4078  */
4079 int
4080 bus_generic_rl_get_resource(device_t dev, device_t child, int type, int rid,
4081     u_long *startp, u_long *countp)
4082 {
4083 	struct resource_list *		rl = NULL;
4084 	struct resource_list_entry *	rle = NULL;
4085 
4086 	rl = BUS_GET_RESOURCE_LIST(dev, child);
4087 	if (!rl)
4088 		return (EINVAL);
4089 
4090 	rle = resource_list_find(rl, type, rid);
4091 	if (!rle)
4092 		return (ENOENT);
4093 
4094 	if (startp)
4095 		*startp = rle->start;
4096 	if (countp)
4097 		*countp = rle->count;
4098 
4099 	return (0);
4100 }
4101 
4102 /**
4103  * @brief Helper function for implementing BUS_SET_RESOURCE().
4104  *
4105  * This implementation of BUS_SET_RESOURCE() uses the
4106  * resource_list_add() function to do most of the work. It calls
4107  * BUS_GET_RESOURCE_LIST() to find a suitable resource list to
4108  * edit.
4109  */
4110 int
4111 bus_generic_rl_set_resource(device_t dev, device_t child, int type, int rid,
4112     u_long start, u_long count)
4113 {
4114 	struct resource_list *		rl = NULL;
4115 
4116 	rl = BUS_GET_RESOURCE_LIST(dev, child);
4117 	if (!rl)
4118 		return (EINVAL);
4119 
4120 	resource_list_add(rl, type, rid, start, (start + count - 1), count);
4121 
4122 	return (0);
4123 }
4124 
4125 /**
4126  * @brief Helper function for implementing BUS_DELETE_RESOURCE().
4127  *
4128  * This implementation of BUS_DELETE_RESOURCE() uses the
4129  * resource_list_delete() function to do most of the work. It calls
4130  * BUS_GET_RESOURCE_LIST() to find a suitable resource list to
4131  * edit.
4132  */
4133 void
4134 bus_generic_rl_delete_resource(device_t dev, device_t child, int type, int rid)
4135 {
4136 	struct resource_list *		rl = NULL;
4137 
4138 	rl = BUS_GET_RESOURCE_LIST(dev, child);
4139 	if (!rl)
4140 		return;
4141 
4142 	resource_list_delete(rl, type, rid);
4143 
4144 	return;
4145 }
4146 
4147 /**
4148  * @brief Helper function for implementing BUS_RELEASE_RESOURCE().
4149  *
4150  * This implementation of BUS_RELEASE_RESOURCE() uses the
4151  * resource_list_release() function to do most of the work. It calls
4152  * BUS_GET_RESOURCE_LIST() to find a suitable resource list.
4153  */
4154 int
4155 bus_generic_rl_release_resource(device_t dev, device_t child, int type,
4156     int rid, struct resource *r)
4157 {
4158 	struct resource_list *		rl = NULL;
4159 
4160 	if (device_get_parent(child) != dev)
4161 		return (BUS_RELEASE_RESOURCE(device_get_parent(dev), child,
4162 		    type, rid, r));
4163 
4164 	rl = BUS_GET_RESOURCE_LIST(dev, child);
4165 	if (!rl)
4166 		return (EINVAL);
4167 
4168 	return (resource_list_release(rl, dev, child, type, rid, r));
4169 }
4170 
4171 /**
4172  * @brief Helper function for implementing BUS_ALLOC_RESOURCE().
4173  *
4174  * This implementation of BUS_ALLOC_RESOURCE() uses the
4175  * resource_list_alloc() function to do most of the work. It calls
4176  * BUS_GET_RESOURCE_LIST() to find a suitable resource list.
4177  */
4178 struct resource *
4179 bus_generic_rl_alloc_resource(device_t dev, device_t child, int type,
4180     int *rid, u_long start, u_long end, u_long count, u_int flags)
4181 {
4182 	struct resource_list *		rl = NULL;
4183 
4184 	if (device_get_parent(child) != dev)
4185 		return (BUS_ALLOC_RESOURCE(device_get_parent(dev), child,
4186 		    type, rid, start, end, count, flags));
4187 
4188 	rl = BUS_GET_RESOURCE_LIST(dev, child);
4189 	if (!rl)
4190 		return (NULL);
4191 
4192 	return (resource_list_alloc(rl, dev, child, type, rid,
4193 	    start, end, count, flags));
4194 }
4195 
4196 /**
4197  * @brief Helper function for implementing BUS_CHILD_PRESENT().
4198  *
4199  * This simple implementation of BUS_CHILD_PRESENT() simply calls the
4200  * BUS_CHILD_PRESENT() method of the parent of @p dev.
4201  */
4202 int
4203 bus_generic_child_present(device_t dev, device_t child)
4204 {
4205 	return (BUS_CHILD_PRESENT(device_get_parent(dev), dev));
4206 }
4207 
4208 int
4209 bus_generic_get_domain(device_t dev, device_t child, int *domain)
4210 {
4211 
4212 	if (dev->parent)
4213 		return (BUS_GET_DOMAIN(dev->parent, dev, domain));
4214 
4215 	return (ENOENT);
4216 }
4217 
4218 /*
4219  * Some convenience functions to make it easier for drivers to use the
4220  * resource-management functions.  All these really do is hide the
4221  * indirection through the parent's method table, making for slightly
4222  * less-wordy code.  In the future, it might make sense for this code
4223  * to maintain some sort of a list of resources allocated by each device.
4224  */
4225 
4226 int
4227 bus_alloc_resources(device_t dev, struct resource_spec *rs,
4228     struct resource **res)
4229 {
4230 	int i;
4231 
4232 	for (i = 0; rs[i].type != -1; i++)
4233 		res[i] = NULL;
4234 	for (i = 0; rs[i].type != -1; i++) {
4235 		res[i] = bus_alloc_resource_any(dev,
4236 		    rs[i].type, &rs[i].rid, rs[i].flags);
4237 		if (res[i] == NULL && !(rs[i].flags & RF_OPTIONAL)) {
4238 			bus_release_resources(dev, rs, res);
4239 			return (ENXIO);
4240 		}
4241 	}
4242 	return (0);
4243 }
4244 
4245 void
4246 bus_release_resources(device_t dev, const struct resource_spec *rs,
4247     struct resource **res)
4248 {
4249 	int i;
4250 
4251 	for (i = 0; rs[i].type != -1; i++)
4252 		if (res[i] != NULL) {
4253 			bus_release_resource(
4254 			    dev, rs[i].type, rs[i].rid, res[i]);
4255 			res[i] = NULL;
4256 		}
4257 }
4258 
4259 /**
4260  * @brief Wrapper function for BUS_ALLOC_RESOURCE().
4261  *
4262  * This function simply calls the BUS_ALLOC_RESOURCE() method of the
4263  * parent of @p dev.
4264  */
4265 struct resource *
4266 bus_alloc_resource(device_t dev, int type, int *rid, u_long start, u_long end,
4267     u_long count, u_int flags)
4268 {
4269 	if (dev->parent == NULL)
4270 		return (NULL);
4271 	return (BUS_ALLOC_RESOURCE(dev->parent, dev, type, rid, start, end,
4272 	    count, flags));
4273 }
4274 
4275 /**
4276  * @brief Wrapper function for BUS_ADJUST_RESOURCE().
4277  *
4278  * This function simply calls the BUS_ADJUST_RESOURCE() method of the
4279  * parent of @p dev.
4280  */
4281 int
4282 bus_adjust_resource(device_t dev, int type, struct resource *r, u_long start,
4283     u_long end)
4284 {
4285 	if (dev->parent == NULL)
4286 		return (EINVAL);
4287 	return (BUS_ADJUST_RESOURCE(dev->parent, dev, type, r, start, end));
4288 }
4289 
4290 /**
4291  * @brief Wrapper function for BUS_ACTIVATE_RESOURCE().
4292  *
4293  * This function simply calls the BUS_ACTIVATE_RESOURCE() method of the
4294  * parent of @p dev.
4295  */
4296 int
4297 bus_activate_resource(device_t dev, int type, int rid, struct resource *r)
4298 {
4299 	if (dev->parent == NULL)
4300 		return (EINVAL);
4301 	return (BUS_ACTIVATE_RESOURCE(dev->parent, dev, type, rid, r));
4302 }
4303 
4304 /**
4305  * @brief Wrapper function for BUS_DEACTIVATE_RESOURCE().
4306  *
4307  * This function simply calls the BUS_DEACTIVATE_RESOURCE() method of the
4308  * parent of @p dev.
4309  */
4310 int
4311 bus_deactivate_resource(device_t dev, int type, int rid, struct resource *r)
4312 {
4313 	if (dev->parent == NULL)
4314 		return (EINVAL);
4315 	return (BUS_DEACTIVATE_RESOURCE(dev->parent, dev, type, rid, r));
4316 }
4317 
4318 /**
4319  * @brief Wrapper function for BUS_RELEASE_RESOURCE().
4320  *
4321  * This function simply calls the BUS_RELEASE_RESOURCE() method of the
4322  * parent of @p dev.
4323  */
4324 int
4325 bus_release_resource(device_t dev, int type, int rid, struct resource *r)
4326 {
4327 	if (dev->parent == NULL)
4328 		return (EINVAL);
4329 	return (BUS_RELEASE_RESOURCE(dev->parent, dev, type, rid, r));
4330 }
4331 
4332 /**
4333  * @brief Wrapper function for BUS_SETUP_INTR().
4334  *
4335  * This function simply calls the BUS_SETUP_INTR() method of the
4336  * parent of @p dev.
4337  */
4338 int
4339 bus_setup_intr(device_t dev, struct resource *r, int flags,
4340     driver_filter_t filter, driver_intr_t handler, void *arg, void **cookiep)
4341 {
4342 	int error;
4343 
4344 	if (dev->parent == NULL)
4345 		return (EINVAL);
4346 	error = BUS_SETUP_INTR(dev->parent, dev, r, flags, filter, handler,
4347 	    arg, cookiep);
4348 	if (error != 0)
4349 		return (error);
4350 	if (handler != NULL && !(flags & INTR_MPSAFE))
4351 		device_printf(dev, "[GIANT-LOCKED]\n");
4352 	return (0);
4353 }
4354 
4355 /**
4356  * @brief Wrapper function for BUS_TEARDOWN_INTR().
4357  *
4358  * This function simply calls the BUS_TEARDOWN_INTR() method of the
4359  * parent of @p dev.
4360  */
4361 int
4362 bus_teardown_intr(device_t dev, struct resource *r, void *cookie)
4363 {
4364 	if (dev->parent == NULL)
4365 		return (EINVAL);
4366 	return (BUS_TEARDOWN_INTR(dev->parent, dev, r, cookie));
4367 }
4368 
4369 /**
4370  * @brief Wrapper function for BUS_BIND_INTR().
4371  *
4372  * This function simply calls the BUS_BIND_INTR() method of the
4373  * parent of @p dev.
4374  */
4375 int
4376 bus_bind_intr(device_t dev, struct resource *r, int cpu)
4377 {
4378 	if (dev->parent == NULL)
4379 		return (EINVAL);
4380 	return (BUS_BIND_INTR(dev->parent, dev, r, cpu));
4381 }
4382 
4383 /**
4384  * @brief Wrapper function for BUS_DESCRIBE_INTR().
4385  *
4386  * This function first formats the requested description into a
4387  * temporary buffer and then calls the BUS_DESCRIBE_INTR() method of
4388  * the parent of @p dev.
4389  */
4390 int
4391 bus_describe_intr(device_t dev, struct resource *irq, void *cookie,
4392     const char *fmt, ...)
4393 {
4394 	va_list ap;
4395 	char descr[MAXCOMLEN + 1];
4396 
4397 	if (dev->parent == NULL)
4398 		return (EINVAL);
4399 	va_start(ap, fmt);
4400 	vsnprintf(descr, sizeof(descr), fmt, ap);
4401 	va_end(ap);
4402 	return (BUS_DESCRIBE_INTR(dev->parent, dev, irq, cookie, descr));
4403 }
4404 
4405 /**
4406  * @brief Wrapper function for BUS_SET_RESOURCE().
4407  *
4408  * This function simply calls the BUS_SET_RESOURCE() method of the
4409  * parent of @p dev.
4410  */
4411 int
4412 bus_set_resource(device_t dev, int type, int rid,
4413     u_long start, u_long count)
4414 {
4415 	return (BUS_SET_RESOURCE(device_get_parent(dev), dev, type, rid,
4416 	    start, count));
4417 }
4418 
4419 /**
4420  * @brief Wrapper function for BUS_GET_RESOURCE().
4421  *
4422  * This function simply calls the BUS_GET_RESOURCE() method of the
4423  * parent of @p dev.
4424  */
4425 int
4426 bus_get_resource(device_t dev, int type, int rid,
4427     u_long *startp, u_long *countp)
4428 {
4429 	return (BUS_GET_RESOURCE(device_get_parent(dev), dev, type, rid,
4430 	    startp, countp));
4431 }
4432 
4433 /**
4434  * @brief Wrapper function for BUS_GET_RESOURCE().
4435  *
4436  * This function simply calls the BUS_GET_RESOURCE() method of the
4437  * parent of @p dev and returns the start value.
4438  */
4439 u_long
4440 bus_get_resource_start(device_t dev, int type, int rid)
4441 {
4442 	u_long start, count;
4443 	int error;
4444 
4445 	error = BUS_GET_RESOURCE(device_get_parent(dev), dev, type, rid,
4446 	    &start, &count);
4447 	if (error)
4448 		return (0);
4449 	return (start);
4450 }
4451 
4452 /**
4453  * @brief Wrapper function for BUS_GET_RESOURCE().
4454  *
4455  * This function simply calls the BUS_GET_RESOURCE() method of the
4456  * parent of @p dev and returns the count value.
4457  */
4458 u_long
4459 bus_get_resource_count(device_t dev, int type, int rid)
4460 {
4461 	u_long start, count;
4462 	int error;
4463 
4464 	error = BUS_GET_RESOURCE(device_get_parent(dev), dev, type, rid,
4465 	    &start, &count);
4466 	if (error)
4467 		return (0);
4468 	return (count);
4469 }
4470 
4471 /**
4472  * @brief Wrapper function for BUS_DELETE_RESOURCE().
4473  *
4474  * This function simply calls the BUS_DELETE_RESOURCE() method of the
4475  * parent of @p dev.
4476  */
4477 void
4478 bus_delete_resource(device_t dev, int type, int rid)
4479 {
4480 	BUS_DELETE_RESOURCE(device_get_parent(dev), dev, type, rid);
4481 }
4482 
4483 /**
4484  * @brief Wrapper function for BUS_CHILD_PRESENT().
4485  *
4486  * This function simply calls the BUS_CHILD_PRESENT() method of the
4487  * parent of @p dev.
4488  */
4489 int
4490 bus_child_present(device_t child)
4491 {
4492 	return (BUS_CHILD_PRESENT(device_get_parent(child), child));
4493 }
4494 
4495 /**
4496  * @brief Wrapper function for BUS_CHILD_PNPINFO_STR().
4497  *
4498  * This function simply calls the BUS_CHILD_PNPINFO_STR() method of the
4499  * parent of @p dev.
4500  */
4501 int
4502 bus_child_pnpinfo_str(device_t child, char *buf, size_t buflen)
4503 {
4504 	device_t parent;
4505 
4506 	parent = device_get_parent(child);
4507 	if (parent == NULL) {
4508 		*buf = '\0';
4509 		return (0);
4510 	}
4511 	return (BUS_CHILD_PNPINFO_STR(parent, child, buf, buflen));
4512 }
4513 
4514 /**
4515  * @brief Wrapper function for BUS_CHILD_LOCATION_STR().
4516  *
4517  * This function simply calls the BUS_CHILD_LOCATION_STR() method of the
4518  * parent of @p dev.
4519  */
4520 int
4521 bus_child_location_str(device_t child, char *buf, size_t buflen)
4522 {
4523 	device_t parent;
4524 
4525 	parent = device_get_parent(child);
4526 	if (parent == NULL) {
4527 		*buf = '\0';
4528 		return (0);
4529 	}
4530 	return (BUS_CHILD_LOCATION_STR(parent, child, buf, buflen));
4531 }
4532 
4533 /**
4534  * @brief Wrapper function for BUS_GET_DMA_TAG().
4535  *
4536  * This function simply calls the BUS_GET_DMA_TAG() method of the
4537  * parent of @p dev.
4538  */
4539 bus_dma_tag_t
4540 bus_get_dma_tag(device_t dev)
4541 {
4542 	device_t parent;
4543 
4544 	parent = device_get_parent(dev);
4545 	if (parent == NULL)
4546 		return (NULL);
4547 	return (BUS_GET_DMA_TAG(parent, dev));
4548 }
4549 
4550 /**
4551  * @brief Wrapper function for BUS_GET_DOMAIN().
4552  *
4553  * This function simply calls the BUS_GET_DOMAIN() method of the
4554  * parent of @p dev.
4555  */
4556 int
4557 bus_get_domain(device_t dev, int *domain)
4558 {
4559 	return (BUS_GET_DOMAIN(device_get_parent(dev), dev, domain));
4560 }
4561 
4562 /* Resume all devices and then notify userland that we're up again. */
4563 static int
4564 root_resume(device_t dev)
4565 {
4566 	int error;
4567 
4568 	error = bus_generic_resume(dev);
4569 	if (error == 0)
4570 		devctl_notify("kern", "power", "resume", NULL);
4571 	return (error);
4572 }
4573 
4574 static int
4575 root_print_child(device_t dev, device_t child)
4576 {
4577 	int	retval = 0;
4578 
4579 	retval += bus_print_child_header(dev, child);
4580 	retval += printf("\n");
4581 
4582 	return (retval);
4583 }
4584 
4585 static int
4586 root_setup_intr(device_t dev, device_t child, struct resource *irq, int flags,
4587     driver_filter_t *filter, driver_intr_t *intr, void *arg, void **cookiep)
4588 {
4589 	/*
4590 	 * If an interrupt mapping gets to here something bad has happened.
4591 	 */
4592 	panic("root_setup_intr");
4593 }
4594 
4595 /*
4596  * If we get here, assume that the device is permanant and really is
4597  * present in the system.  Removable bus drivers are expected to intercept
4598  * this call long before it gets here.  We return -1 so that drivers that
4599  * really care can check vs -1 or some ERRNO returned higher in the food
4600  * chain.
4601  */
4602 static int
4603 root_child_present(device_t dev, device_t child)
4604 {
4605 	return (-1);
4606 }
4607 
4608 static kobj_method_t root_methods[] = {
4609 	/* Device interface */
4610 	KOBJMETHOD(device_shutdown,	bus_generic_shutdown),
4611 	KOBJMETHOD(device_suspend,	bus_generic_suspend),
4612 	KOBJMETHOD(device_resume,	root_resume),
4613 
4614 	/* Bus interface */
4615 	KOBJMETHOD(bus_print_child,	root_print_child),
4616 	KOBJMETHOD(bus_read_ivar,	bus_generic_read_ivar),
4617 	KOBJMETHOD(bus_write_ivar,	bus_generic_write_ivar),
4618 	KOBJMETHOD(bus_setup_intr,	root_setup_intr),
4619 	KOBJMETHOD(bus_child_present,	root_child_present),
4620 
4621 	KOBJMETHOD_END
4622 };
4623 
4624 static driver_t root_driver = {
4625 	"root",
4626 	root_methods,
4627 	1,			/* no softc */
4628 };
4629 
4630 device_t	root_bus;
4631 devclass_t	root_devclass;
4632 
4633 static int
4634 root_bus_module_handler(module_t mod, int what, void* arg)
4635 {
4636 	switch (what) {
4637 	case MOD_LOAD:
4638 		TAILQ_INIT(&bus_data_devices);
4639 		kobj_class_compile((kobj_class_t) &root_driver);
4640 		root_bus = make_device(NULL, "root", 0);
4641 		root_bus->desc = "System root bus";
4642 		kobj_init((kobj_t) root_bus, (kobj_class_t) &root_driver);
4643 		root_bus->driver = &root_driver;
4644 		root_bus->state = DS_ATTACHED;
4645 		root_devclass = devclass_find_internal("root", NULL, FALSE);
4646 		devinit();
4647 		return (0);
4648 
4649 	case MOD_SHUTDOWN:
4650 		device_shutdown(root_bus);
4651 		return (0);
4652 	default:
4653 		return (EOPNOTSUPP);
4654 	}
4655 
4656 	return (0);
4657 }
4658 
4659 static moduledata_t root_bus_mod = {
4660 	"rootbus",
4661 	root_bus_module_handler,
4662 	NULL
4663 };
4664 DECLARE_MODULE(rootbus, root_bus_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
4665 
4666 /**
4667  * @brief Automatically configure devices
4668  *
4669  * This function begins the autoconfiguration process by calling
4670  * device_probe_and_attach() for each child of the @c root0 device.
4671  */
4672 void
4673 root_bus_configure(void)
4674 {
4675 
4676 	PDEBUG(("."));
4677 
4678 	/* Eventually this will be split up, but this is sufficient for now. */
4679 	bus_set_pass(BUS_PASS_DEFAULT);
4680 }
4681 
4682 /**
4683  * @brief Module handler for registering device drivers
4684  *
4685  * This module handler is used to automatically register device
4686  * drivers when modules are loaded. If @p what is MOD_LOAD, it calls
4687  * devclass_add_driver() for the driver described by the
4688  * driver_module_data structure pointed to by @p arg
4689  */
4690 int
4691 driver_module_handler(module_t mod, int what, void *arg)
4692 {
4693 	struct driver_module_data *dmd;
4694 	devclass_t bus_devclass;
4695 	kobj_class_t driver;
4696 	int error, pass;
4697 
4698 	dmd = (struct driver_module_data *)arg;
4699 	bus_devclass = devclass_find_internal(dmd->dmd_busname, NULL, TRUE);
4700 	error = 0;
4701 
4702 	switch (what) {
4703 	case MOD_LOAD:
4704 		if (dmd->dmd_chainevh)
4705 			error = dmd->dmd_chainevh(mod,what,dmd->dmd_chainarg);
4706 
4707 		pass = dmd->dmd_pass;
4708 		driver = dmd->dmd_driver;
4709 		PDEBUG(("Loading module: driver %s on bus %s (pass %d)",
4710 		    DRIVERNAME(driver), dmd->dmd_busname, pass));
4711 		error = devclass_add_driver(bus_devclass, driver, pass,
4712 		    dmd->dmd_devclass);
4713 		break;
4714 
4715 	case MOD_UNLOAD:
4716 		PDEBUG(("Unloading module: driver %s from bus %s",
4717 		    DRIVERNAME(dmd->dmd_driver),
4718 		    dmd->dmd_busname));
4719 		error = devclass_delete_driver(bus_devclass,
4720 		    dmd->dmd_driver);
4721 
4722 		if (!error && dmd->dmd_chainevh)
4723 			error = dmd->dmd_chainevh(mod,what,dmd->dmd_chainarg);
4724 		break;
4725 	case MOD_QUIESCE:
4726 		PDEBUG(("Quiesce module: driver %s from bus %s",
4727 		    DRIVERNAME(dmd->dmd_driver),
4728 		    dmd->dmd_busname));
4729 		error = devclass_quiesce_driver(bus_devclass,
4730 		    dmd->dmd_driver);
4731 
4732 		if (!error && dmd->dmd_chainevh)
4733 			error = dmd->dmd_chainevh(mod,what,dmd->dmd_chainarg);
4734 		break;
4735 	default:
4736 		error = EOPNOTSUPP;
4737 		break;
4738 	}
4739 
4740 	return (error);
4741 }
4742 
4743 /**
4744  * @brief Enumerate all hinted devices for this bus.
4745  *
4746  * Walks through the hints for this bus and calls the bus_hinted_child
4747  * routine for each one it fines.  It searches first for the specific
4748  * bus that's being probed for hinted children (eg isa0), and then for
4749  * generic children (eg isa).
4750  *
4751  * @param	dev	bus device to enumerate
4752  */
4753 void
4754 bus_enumerate_hinted_children(device_t bus)
4755 {
4756 	int i;
4757 	const char *dname, *busname;
4758 	int dunit;
4759 
4760 	/*
4761 	 * enumerate all devices on the specific bus
4762 	 */
4763 	busname = device_get_nameunit(bus);
4764 	i = 0;
4765 	while (resource_find_match(&i, &dname, &dunit, "at", busname) == 0)
4766 		BUS_HINTED_CHILD(bus, dname, dunit);
4767 
4768 	/*
4769 	 * and all the generic ones.
4770 	 */
4771 	busname = device_get_name(bus);
4772 	i = 0;
4773 	while (resource_find_match(&i, &dname, &dunit, "at", busname) == 0)
4774 		BUS_HINTED_CHILD(bus, dname, dunit);
4775 }
4776 
4777 #ifdef BUS_DEBUG
4778 
4779 /* the _short versions avoid iteration by not calling anything that prints
4780  * more than oneliners. I love oneliners.
4781  */
4782 
4783 static void
4784 print_device_short(device_t dev, int indent)
4785 {
4786 	if (!dev)
4787 		return;
4788 
4789 	indentprintf(("device %d: <%s> %sparent,%schildren,%s%s%s%s%s,%sivars,%ssoftc,busy=%d\n",
4790 	    dev->unit, dev->desc,
4791 	    (dev->parent? "":"no "),
4792 	    (TAILQ_EMPTY(&dev->children)? "no ":""),
4793 	    (dev->flags&DF_ENABLED? "enabled,":"disabled,"),
4794 	    (dev->flags&DF_FIXEDCLASS? "fixed,":""),
4795 	    (dev->flags&DF_WILDCARD? "wildcard,":""),
4796 	    (dev->flags&DF_DESCMALLOCED? "descmalloced,":""),
4797 	    (dev->flags&DF_REBID? "rebiddable,":""),
4798 	    (dev->ivars? "":"no "),
4799 	    (dev->softc? "":"no "),
4800 	    dev->busy));
4801 }
4802 
4803 static void
4804 print_device(device_t dev, int indent)
4805 {
4806 	if (!dev)
4807 		return;
4808 
4809 	print_device_short(dev, indent);
4810 
4811 	indentprintf(("Parent:\n"));
4812 	print_device_short(dev->parent, indent+1);
4813 	indentprintf(("Driver:\n"));
4814 	print_driver_short(dev->driver, indent+1);
4815 	indentprintf(("Devclass:\n"));
4816 	print_devclass_short(dev->devclass, indent+1);
4817 }
4818 
4819 void
4820 print_device_tree_short(device_t dev, int indent)
4821 /* print the device and all its children (indented) */
4822 {
4823 	device_t child;
4824 
4825 	if (!dev)
4826 		return;
4827 
4828 	print_device_short(dev, indent);
4829 
4830 	TAILQ_FOREACH(child, &dev->children, link) {
4831 		print_device_tree_short(child, indent+1);
4832 	}
4833 }
4834 
4835 void
4836 print_device_tree(device_t dev, int indent)
4837 /* print the device and all its children (indented) */
4838 {
4839 	device_t child;
4840 
4841 	if (!dev)
4842 		return;
4843 
4844 	print_device(dev, indent);
4845 
4846 	TAILQ_FOREACH(child, &dev->children, link) {
4847 		print_device_tree(child, indent+1);
4848 	}
4849 }
4850 
4851 static void
4852 print_driver_short(driver_t *driver, int indent)
4853 {
4854 	if (!driver)
4855 		return;
4856 
4857 	indentprintf(("driver %s: softc size = %zd\n",
4858 	    driver->name, driver->size));
4859 }
4860 
4861 static void
4862 print_driver(driver_t *driver, int indent)
4863 {
4864 	if (!driver)
4865 		return;
4866 
4867 	print_driver_short(driver, indent);
4868 }
4869 
4870 static void
4871 print_driver_list(driver_list_t drivers, int indent)
4872 {
4873 	driverlink_t driver;
4874 
4875 	TAILQ_FOREACH(driver, &drivers, link) {
4876 		print_driver(driver->driver, indent);
4877 	}
4878 }
4879 
4880 static void
4881 print_devclass_short(devclass_t dc, int indent)
4882 {
4883 	if ( !dc )
4884 		return;
4885 
4886 	indentprintf(("devclass %s: max units = %d\n", dc->name, dc->maxunit));
4887 }
4888 
4889 static void
4890 print_devclass(devclass_t dc, int indent)
4891 {
4892 	int i;
4893 
4894 	if ( !dc )
4895 		return;
4896 
4897 	print_devclass_short(dc, indent);
4898 	indentprintf(("Drivers:\n"));
4899 	print_driver_list(dc->drivers, indent+1);
4900 
4901 	indentprintf(("Devices:\n"));
4902 	for (i = 0; i < dc->maxunit; i++)
4903 		if (dc->devices[i])
4904 			print_device(dc->devices[i], indent+1);
4905 }
4906 
4907 void
4908 print_devclass_list_short(void)
4909 {
4910 	devclass_t dc;
4911 
4912 	printf("Short listing of devclasses, drivers & devices:\n");
4913 	TAILQ_FOREACH(dc, &devclasses, link) {
4914 		print_devclass_short(dc, 0);
4915 	}
4916 }
4917 
4918 void
4919 print_devclass_list(void)
4920 {
4921 	devclass_t dc;
4922 
4923 	printf("Full listing of devclasses, drivers & devices:\n");
4924 	TAILQ_FOREACH(dc, &devclasses, link) {
4925 		print_devclass(dc, 0);
4926 	}
4927 }
4928 
4929 #endif
4930 
4931 /*
4932  * User-space access to the device tree.
4933  *
4934  * We implement a small set of nodes:
4935  *
4936  * hw.bus			Single integer read method to obtain the
4937  *				current generation count.
4938  * hw.bus.devices		Reads the entire device tree in flat space.
4939  * hw.bus.rman			Resource manager interface
4940  *
4941  * We might like to add the ability to scan devclasses and/or drivers to
4942  * determine what else is currently loaded/available.
4943  */
4944 
4945 static int
4946 sysctl_bus(SYSCTL_HANDLER_ARGS)
4947 {
4948 	struct u_businfo	ubus;
4949 
4950 	ubus.ub_version = BUS_USER_VERSION;
4951 	ubus.ub_generation = bus_data_generation;
4952 
4953 	return (SYSCTL_OUT(req, &ubus, sizeof(ubus)));
4954 }
4955 SYSCTL_NODE(_hw_bus, OID_AUTO, info, CTLFLAG_RW, sysctl_bus,
4956     "bus-related data");
4957 
4958 static int
4959 sysctl_devices(SYSCTL_HANDLER_ARGS)
4960 {
4961 	int			*name = (int *)arg1;
4962 	u_int			namelen = arg2;
4963 	int			index;
4964 	struct device		*dev;
4965 	struct u_device		udev;	/* XXX this is a bit big */
4966 	int			error;
4967 
4968 	if (namelen != 2)
4969 		return (EINVAL);
4970 
4971 	if (bus_data_generation_check(name[0]))
4972 		return (EINVAL);
4973 
4974 	index = name[1];
4975 
4976 	/*
4977 	 * Scan the list of devices, looking for the requested index.
4978 	 */
4979 	TAILQ_FOREACH(dev, &bus_data_devices, devlink) {
4980 		if (index-- == 0)
4981 			break;
4982 	}
4983 	if (dev == NULL)
4984 		return (ENOENT);
4985 
4986 	/*
4987 	 * Populate the return array.
4988 	 */
4989 	bzero(&udev, sizeof(udev));
4990 	udev.dv_handle = (uintptr_t)dev;
4991 	udev.dv_parent = (uintptr_t)dev->parent;
4992 	if (dev->nameunit != NULL)
4993 		strlcpy(udev.dv_name, dev->nameunit, sizeof(udev.dv_name));
4994 	if (dev->desc != NULL)
4995 		strlcpy(udev.dv_desc, dev->desc, sizeof(udev.dv_desc));
4996 	if (dev->driver != NULL && dev->driver->name != NULL)
4997 		strlcpy(udev.dv_drivername, dev->driver->name,
4998 		    sizeof(udev.dv_drivername));
4999 	bus_child_pnpinfo_str(dev, udev.dv_pnpinfo, sizeof(udev.dv_pnpinfo));
5000 	bus_child_location_str(dev, udev.dv_location, sizeof(udev.dv_location));
5001 	udev.dv_devflags = dev->devflags;
5002 	udev.dv_flags = dev->flags;
5003 	udev.dv_state = dev->state;
5004 	error = SYSCTL_OUT(req, &udev, sizeof(udev));
5005 	return (error);
5006 }
5007 
5008 SYSCTL_NODE(_hw_bus, OID_AUTO, devices, CTLFLAG_RD, sysctl_devices,
5009     "system device tree");
5010 
5011 int
5012 bus_data_generation_check(int generation)
5013 {
5014 	if (generation != bus_data_generation)
5015 		return (1);
5016 
5017 	/* XXX generate optimised lists here? */
5018 	return (0);
5019 }
5020 
5021 void
5022 bus_data_generation_update(void)
5023 {
5024 	bus_data_generation++;
5025 }
5026 
5027 int
5028 bus_free_resource(device_t dev, int type, struct resource *r)
5029 {
5030 	if (r == NULL)
5031 		return (0);
5032 	return (bus_release_resource(dev, type, rman_get_rid(r), r));
5033 }
5034