xref: /freebsd/sys/kern/subr_bus.c (revision 9fe48b8076ae9c6dc486d713c468ff03ec056eda)
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/priv.h>
45 #include <sys/proc.h>
46 #include <sys/condvar.h>
47 #include <sys/queue.h>
48 #include <machine/bus.h>
49 #include <sys/random.h>
50 #include <sys/rman.h>
51 #include <sys/selinfo.h>
52 #include <sys/signalvar.h>
53 #include <sys/sysctl.h>
54 #include <sys/systm.h>
55 #include <sys/uio.h>
56 #include <sys/bus.h>
57 #include <sys/interrupt.h>
58 #include <sys/cpuset.h>
59 
60 #include <net/vnet.h>
61 
62 #include <machine/cpu.h>
63 #include <machine/stdarg.h>
64 
65 #include <vm/uma.h>
66 
67 SYSCTL_NODE(_hw, OID_AUTO, bus, CTLFLAG_RW, NULL, NULL);
68 SYSCTL_ROOT_NODE(OID_AUTO, dev, CTLFLAG_RW, NULL, NULL);
69 
70 /*
71  * Used to attach drivers to devclasses.
72  */
73 typedef struct driverlink *driverlink_t;
74 struct driverlink {
75 	kobj_class_t	driver;
76 	TAILQ_ENTRY(driverlink) link;	/* list of drivers in devclass */
77 	int		pass;
78 	TAILQ_ENTRY(driverlink) passlink;
79 };
80 
81 /*
82  * Forward declarations
83  */
84 typedef TAILQ_HEAD(devclass_list, devclass) devclass_list_t;
85 typedef TAILQ_HEAD(driver_list, driverlink) driver_list_t;
86 typedef TAILQ_HEAD(device_list, device) device_list_t;
87 
88 struct devclass {
89 	TAILQ_ENTRY(devclass) link;
90 	devclass_t	parent;		/* parent in devclass hierarchy */
91 	driver_list_t	drivers;     /* bus devclasses store drivers for bus */
92 	char		*name;
93 	device_t	*devices;	/* array of devices indexed by unit */
94 	int		maxunit;	/* size of devices array */
95 	int		flags;
96 #define DC_HAS_CHILDREN		1
97 
98 	struct sysctl_ctx_list sysctl_ctx;
99 	struct sysctl_oid *sysctl_tree;
100 };
101 
102 /**
103  * @brief Implementation of device.
104  */
105 struct device {
106 	/*
107 	 * A device is a kernel object. The first field must be the
108 	 * current ops table for the object.
109 	 */
110 	KOBJ_FIELDS;
111 
112 	/*
113 	 * Device hierarchy.
114 	 */
115 	TAILQ_ENTRY(device)	link;	/**< list of devices in parent */
116 	TAILQ_ENTRY(device)	devlink; /**< global device list membership */
117 	device_t	parent;		/**< parent of this device  */
118 	device_list_t	children;	/**< list of child devices */
119 
120 	/*
121 	 * Details of this device.
122 	 */
123 	driver_t	*driver;	/**< current driver */
124 	devclass_t	devclass;	/**< current device class */
125 	int		unit;		/**< current unit number */
126 	char*		nameunit;	/**< name+unit e.g. foodev0 */
127 	char*		desc;		/**< driver specific description */
128 	int		busy;		/**< count of calls to device_busy() */
129 	device_state_t	state;		/**< current device state  */
130 	uint32_t	devflags;	/**< api level flags for device_get_flags() */
131 	u_int		flags;		/**< internal device flags  */
132 	u_int	order;			/**< order from device_add_child_ordered() */
133 	void	*ivars;			/**< instance variables  */
134 	void	*softc;			/**< current driver's variables  */
135 
136 	struct sysctl_ctx_list sysctl_ctx; /**< state for sysctl variables  */
137 	struct sysctl_oid *sysctl_tree;	/**< state for sysctl variables */
138 };
139 
140 static MALLOC_DEFINE(M_BUS, "bus", "Bus data structures");
141 static MALLOC_DEFINE(M_BUS_SC, "bus-sc", "Bus data structures, softc");
142 
143 static void devctl2_init(void);
144 
145 #ifdef BUS_DEBUG
146 
147 static int bus_debug = 1;
148 SYSCTL_INT(_debug, OID_AUTO, bus_debug, CTLFLAG_RWTUN, &bus_debug, 0,
149     "Bus debug level");
150 
151 #define PDEBUG(a)	if (bus_debug) {printf("%s:%d: ", __func__, __LINE__), printf a; printf("\n");}
152 #define DEVICENAME(d)	((d)? device_get_name(d): "no device")
153 #define DRIVERNAME(d)	((d)? d->name : "no driver")
154 #define DEVCLANAME(d)	((d)? d->name : "no devclass")
155 
156 /**
157  * Produce the indenting, indent*2 spaces plus a '.' ahead of that to
158  * prevent syslog from deleting initial spaces
159  */
160 #define indentprintf(p)	do { int iJ; printf("."); for (iJ=0; iJ<indent; iJ++) printf("  "); printf p ; } while (0)
161 
162 static void print_device_short(device_t dev, int indent);
163 static void print_device(device_t dev, int indent);
164 void print_device_tree_short(device_t dev, int indent);
165 void print_device_tree(device_t dev, int indent);
166 static void print_driver_short(driver_t *driver, int indent);
167 static void print_driver(driver_t *driver, int indent);
168 static void print_driver_list(driver_list_t drivers, int indent);
169 static void print_devclass_short(devclass_t dc, int indent);
170 static void print_devclass(devclass_t dc, int indent);
171 void print_devclass_list_short(void);
172 void print_devclass_list(void);
173 
174 #else
175 /* Make the compiler ignore the function calls */
176 #define PDEBUG(a)			/* nop */
177 #define DEVICENAME(d)			/* nop */
178 #define DRIVERNAME(d)			/* nop */
179 #define DEVCLANAME(d)			/* nop */
180 
181 #define print_device_short(d,i)		/* nop */
182 #define print_device(d,i)		/* nop */
183 #define print_device_tree_short(d,i)	/* nop */
184 #define print_device_tree(d,i)		/* nop */
185 #define print_driver_short(d,i)		/* nop */
186 #define print_driver(d,i)		/* nop */
187 #define print_driver_list(d,i)		/* nop */
188 #define print_devclass_short(d,i)	/* nop */
189 #define print_devclass(d,i)		/* nop */
190 #define print_devclass_list_short()	/* nop */
191 #define print_devclass_list()		/* nop */
192 #endif
193 
194 /*
195  * dev sysctl tree
196  */
197 
198 enum {
199 	DEVCLASS_SYSCTL_PARENT,
200 };
201 
202 static int
203 devclass_sysctl_handler(SYSCTL_HANDLER_ARGS)
204 {
205 	devclass_t dc = (devclass_t)arg1;
206 	const char *value;
207 
208 	switch (arg2) {
209 	case DEVCLASS_SYSCTL_PARENT:
210 		value = dc->parent ? dc->parent->name : "";
211 		break;
212 	default:
213 		return (EINVAL);
214 	}
215 	return (SYSCTL_OUT_STR(req, value));
216 }
217 
218 static void
219 devclass_sysctl_init(devclass_t dc)
220 {
221 
222 	if (dc->sysctl_tree != NULL)
223 		return;
224 	sysctl_ctx_init(&dc->sysctl_ctx);
225 	dc->sysctl_tree = SYSCTL_ADD_NODE(&dc->sysctl_ctx,
226 	    SYSCTL_STATIC_CHILDREN(_dev), OID_AUTO, dc->name,
227 	    CTLFLAG_RD, NULL, "");
228 	SYSCTL_ADD_PROC(&dc->sysctl_ctx, SYSCTL_CHILDREN(dc->sysctl_tree),
229 	    OID_AUTO, "%parent", CTLTYPE_STRING | CTLFLAG_RD,
230 	    dc, DEVCLASS_SYSCTL_PARENT, devclass_sysctl_handler, "A",
231 	    "parent class");
232 }
233 
234 enum {
235 	DEVICE_SYSCTL_DESC,
236 	DEVICE_SYSCTL_DRIVER,
237 	DEVICE_SYSCTL_LOCATION,
238 	DEVICE_SYSCTL_PNPINFO,
239 	DEVICE_SYSCTL_PARENT,
240 };
241 
242 static int
243 device_sysctl_handler(SYSCTL_HANDLER_ARGS)
244 {
245 	device_t dev = (device_t)arg1;
246 	const char *value;
247 	char *buf;
248 	int error;
249 
250 	buf = NULL;
251 	switch (arg2) {
252 	case DEVICE_SYSCTL_DESC:
253 		value = dev->desc ? dev->desc : "";
254 		break;
255 	case DEVICE_SYSCTL_DRIVER:
256 		value = dev->driver ? dev->driver->name : "";
257 		break;
258 	case DEVICE_SYSCTL_LOCATION:
259 		value = buf = malloc(1024, M_BUS, M_WAITOK | M_ZERO);
260 		bus_child_location_str(dev, buf, 1024);
261 		break;
262 	case DEVICE_SYSCTL_PNPINFO:
263 		value = buf = malloc(1024, M_BUS, M_WAITOK | M_ZERO);
264 		bus_child_pnpinfo_str(dev, buf, 1024);
265 		break;
266 	case DEVICE_SYSCTL_PARENT:
267 		value = dev->parent ? dev->parent->nameunit : "";
268 		break;
269 	default:
270 		return (EINVAL);
271 	}
272 	error = SYSCTL_OUT_STR(req, value);
273 	if (buf != NULL)
274 		free(buf, M_BUS);
275 	return (error);
276 }
277 
278 static void
279 device_sysctl_init(device_t dev)
280 {
281 	devclass_t dc = dev->devclass;
282 	int domain;
283 
284 	if (dev->sysctl_tree != NULL)
285 		return;
286 	devclass_sysctl_init(dc);
287 	sysctl_ctx_init(&dev->sysctl_ctx);
288 	dev->sysctl_tree = SYSCTL_ADD_NODE(&dev->sysctl_ctx,
289 	    SYSCTL_CHILDREN(dc->sysctl_tree), OID_AUTO,
290 	    dev->nameunit + strlen(dc->name),
291 	    CTLFLAG_RD, NULL, "");
292 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
293 	    OID_AUTO, "%desc", CTLTYPE_STRING | CTLFLAG_RD,
294 	    dev, DEVICE_SYSCTL_DESC, device_sysctl_handler, "A",
295 	    "device description");
296 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
297 	    OID_AUTO, "%driver", CTLTYPE_STRING | CTLFLAG_RD,
298 	    dev, DEVICE_SYSCTL_DRIVER, device_sysctl_handler, "A",
299 	    "device driver name");
300 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
301 	    OID_AUTO, "%location", CTLTYPE_STRING | CTLFLAG_RD,
302 	    dev, DEVICE_SYSCTL_LOCATION, device_sysctl_handler, "A",
303 	    "device location relative to parent");
304 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
305 	    OID_AUTO, "%pnpinfo", CTLTYPE_STRING | CTLFLAG_RD,
306 	    dev, DEVICE_SYSCTL_PNPINFO, device_sysctl_handler, "A",
307 	    "device identification");
308 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
309 	    OID_AUTO, "%parent", CTLTYPE_STRING | CTLFLAG_RD,
310 	    dev, DEVICE_SYSCTL_PARENT, device_sysctl_handler, "A",
311 	    "parent device");
312 	if (bus_get_domain(dev, &domain) == 0)
313 		SYSCTL_ADD_INT(&dev->sysctl_ctx,
314 		    SYSCTL_CHILDREN(dev->sysctl_tree), OID_AUTO, "%domain",
315 		    CTLFLAG_RD, NULL, domain, "NUMA domain");
316 }
317 
318 static void
319 device_sysctl_update(device_t dev)
320 {
321 	devclass_t dc = dev->devclass;
322 
323 	if (dev->sysctl_tree == NULL)
324 		return;
325 	sysctl_rename_oid(dev->sysctl_tree, dev->nameunit + strlen(dc->name));
326 }
327 
328 static void
329 device_sysctl_fini(device_t dev)
330 {
331 	if (dev->sysctl_tree == NULL)
332 		return;
333 	sysctl_ctx_free(&dev->sysctl_ctx);
334 	dev->sysctl_tree = NULL;
335 }
336 
337 /*
338  * /dev/devctl implementation
339  */
340 
341 /*
342  * This design allows only one reader for /dev/devctl.  This is not desirable
343  * in the long run, but will get a lot of hair out of this implementation.
344  * Maybe we should make this device a clonable device.
345  *
346  * Also note: we specifically do not attach a device to the device_t tree
347  * to avoid potential chicken and egg problems.  One could argue that all
348  * of this belongs to the root node.  One could also further argue that the
349  * sysctl interface that we have not might more properly be an ioctl
350  * interface, but at this stage of the game, I'm not inclined to rock that
351  * boat.
352  *
353  * I'm also not sure that the SIGIO support is done correctly or not, as
354  * I copied it from a driver that had SIGIO support that likely hasn't been
355  * tested since 3.4 or 2.2.8!
356  */
357 
358 /* Deprecated way to adjust queue length */
359 static int sysctl_devctl_disable(SYSCTL_HANDLER_ARGS);
360 SYSCTL_PROC(_hw_bus, OID_AUTO, devctl_disable, CTLTYPE_INT | CTLFLAG_RWTUN |
361     CTLFLAG_MPSAFE, NULL, 0, sysctl_devctl_disable, "I",
362     "devctl disable -- deprecated");
363 
364 #define DEVCTL_DEFAULT_QUEUE_LEN 1000
365 static int sysctl_devctl_queue(SYSCTL_HANDLER_ARGS);
366 static int devctl_queue_length = DEVCTL_DEFAULT_QUEUE_LEN;
367 SYSCTL_PROC(_hw_bus, OID_AUTO, devctl_queue, CTLTYPE_INT | CTLFLAG_RWTUN |
368     CTLFLAG_MPSAFE, NULL, 0, sysctl_devctl_queue, "I", "devctl queue length");
369 
370 static d_open_t		devopen;
371 static d_close_t	devclose;
372 static d_read_t		devread;
373 static d_ioctl_t	devioctl;
374 static d_poll_t		devpoll;
375 static d_kqfilter_t	devkqfilter;
376 
377 static struct cdevsw dev_cdevsw = {
378 	.d_version =	D_VERSION,
379 	.d_open =	devopen,
380 	.d_close =	devclose,
381 	.d_read =	devread,
382 	.d_ioctl =	devioctl,
383 	.d_poll =	devpoll,
384 	.d_kqfilter =	devkqfilter,
385 	.d_name =	"devctl",
386 };
387 
388 struct dev_event_info
389 {
390 	char *dei_data;
391 	TAILQ_ENTRY(dev_event_info) dei_link;
392 };
393 
394 TAILQ_HEAD(devq, dev_event_info);
395 
396 static struct dev_softc
397 {
398 	int	inuse;
399 	int	nonblock;
400 	int	queued;
401 	int	async;
402 	struct mtx mtx;
403 	struct cv cv;
404 	struct selinfo sel;
405 	struct devq devq;
406 	struct sigio *sigio;
407 } devsoftc;
408 
409 static void	filt_devctl_detach(struct knote *kn);
410 static int	filt_devctl_read(struct knote *kn, long hint);
411 
412 struct filterops devctl_rfiltops = {
413 	.f_isfd = 1,
414 	.f_detach = filt_devctl_detach,
415 	.f_event = filt_devctl_read,
416 };
417 
418 static struct cdev *devctl_dev;
419 
420 static void
421 devinit(void)
422 {
423 	devctl_dev = make_dev_credf(MAKEDEV_ETERNAL, &dev_cdevsw, 0, NULL,
424 	    UID_ROOT, GID_WHEEL, 0600, "devctl");
425 	mtx_init(&devsoftc.mtx, "dev mtx", "devd", MTX_DEF);
426 	cv_init(&devsoftc.cv, "dev cv");
427 	TAILQ_INIT(&devsoftc.devq);
428 	knlist_init_mtx(&devsoftc.sel.si_note, &devsoftc.mtx);
429 	devctl2_init();
430 }
431 
432 static int
433 devopen(struct cdev *dev, int oflags, int devtype, struct thread *td)
434 {
435 
436 	mtx_lock(&devsoftc.mtx);
437 	if (devsoftc.inuse) {
438 		mtx_unlock(&devsoftc.mtx);
439 		return (EBUSY);
440 	}
441 	/* move to init */
442 	devsoftc.inuse = 1;
443 	mtx_unlock(&devsoftc.mtx);
444 	return (0);
445 }
446 
447 static int
448 devclose(struct cdev *dev, int fflag, int devtype, struct thread *td)
449 {
450 
451 	mtx_lock(&devsoftc.mtx);
452 	devsoftc.inuse = 0;
453 	devsoftc.nonblock = 0;
454 	devsoftc.async = 0;
455 	cv_broadcast(&devsoftc.cv);
456 	funsetown(&devsoftc.sigio);
457 	mtx_unlock(&devsoftc.mtx);
458 	return (0);
459 }
460 
461 /*
462  * The read channel for this device is used to report changes to
463  * userland in realtime.  We are required to free the data as well as
464  * the n1 object because we allocate them separately.  Also note that
465  * we return one record at a time.  If you try to read this device a
466  * character at a time, you will lose the rest of the data.  Listening
467  * programs are expected to cope.
468  */
469 static int
470 devread(struct cdev *dev, struct uio *uio, int ioflag)
471 {
472 	struct dev_event_info *n1;
473 	int rv;
474 
475 	mtx_lock(&devsoftc.mtx);
476 	while (TAILQ_EMPTY(&devsoftc.devq)) {
477 		if (devsoftc.nonblock) {
478 			mtx_unlock(&devsoftc.mtx);
479 			return (EAGAIN);
480 		}
481 		rv = cv_wait_sig(&devsoftc.cv, &devsoftc.mtx);
482 		if (rv) {
483 			/*
484 			 * Need to translate ERESTART to EINTR here? -- jake
485 			 */
486 			mtx_unlock(&devsoftc.mtx);
487 			return (rv);
488 		}
489 	}
490 	n1 = TAILQ_FIRST(&devsoftc.devq);
491 	TAILQ_REMOVE(&devsoftc.devq, n1, dei_link);
492 	devsoftc.queued--;
493 	mtx_unlock(&devsoftc.mtx);
494 	rv = uiomove(n1->dei_data, strlen(n1->dei_data), uio);
495 	free(n1->dei_data, M_BUS);
496 	free(n1, M_BUS);
497 	return (rv);
498 }
499 
500 static	int
501 devioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
502 {
503 	switch (cmd) {
504 
505 	case FIONBIO:
506 		if (*(int*)data)
507 			devsoftc.nonblock = 1;
508 		else
509 			devsoftc.nonblock = 0;
510 		return (0);
511 	case FIOASYNC:
512 		if (*(int*)data)
513 			devsoftc.async = 1;
514 		else
515 			devsoftc.async = 0;
516 		return (0);
517 	case FIOSETOWN:
518 		return fsetown(*(int *)data, &devsoftc.sigio);
519 	case FIOGETOWN:
520 		*(int *)data = fgetown(&devsoftc.sigio);
521 		return (0);
522 
523 		/* (un)Support for other fcntl() calls. */
524 	case FIOCLEX:
525 	case FIONCLEX:
526 	case FIONREAD:
527 	default:
528 		break;
529 	}
530 	return (ENOTTY);
531 }
532 
533 static	int
534 devpoll(struct cdev *dev, int events, struct thread *td)
535 {
536 	int	revents = 0;
537 
538 	mtx_lock(&devsoftc.mtx);
539 	if (events & (POLLIN | POLLRDNORM)) {
540 		if (!TAILQ_EMPTY(&devsoftc.devq))
541 			revents = events & (POLLIN | POLLRDNORM);
542 		else
543 			selrecord(td, &devsoftc.sel);
544 	}
545 	mtx_unlock(&devsoftc.mtx);
546 
547 	return (revents);
548 }
549 
550 static int
551 devkqfilter(struct cdev *dev, struct knote *kn)
552 {
553 	int error;
554 
555 	if (kn->kn_filter == EVFILT_READ) {
556 		kn->kn_fop = &devctl_rfiltops;
557 		knlist_add(&devsoftc.sel.si_note, kn, 0);
558 		error = 0;
559 	} else
560 		error = EINVAL;
561 	return (error);
562 }
563 
564 static void
565 filt_devctl_detach(struct knote *kn)
566 {
567 
568 	knlist_remove(&devsoftc.sel.si_note, kn, 0);
569 }
570 
571 static int
572 filt_devctl_read(struct knote *kn, long hint)
573 {
574 	kn->kn_data = devsoftc.queued;
575 	return (kn->kn_data != 0);
576 }
577 
578 /**
579  * @brief Return whether the userland process is running
580  */
581 boolean_t
582 devctl_process_running(void)
583 {
584 	return (devsoftc.inuse == 1);
585 }
586 
587 /**
588  * @brief Queue data to be read from the devctl device
589  *
590  * Generic interface to queue data to the devctl device.  It is
591  * assumed that @p data is properly formatted.  It is further assumed
592  * that @p data is allocated using the M_BUS malloc type.
593  */
594 void
595 devctl_queue_data_f(char *data, int flags)
596 {
597 	struct dev_event_info *n1 = NULL, *n2 = NULL;
598 
599 	if (strlen(data) == 0)
600 		goto out;
601 	if (devctl_queue_length == 0)
602 		goto out;
603 	n1 = malloc(sizeof(*n1), M_BUS, flags);
604 	if (n1 == NULL)
605 		goto out;
606 	n1->dei_data = data;
607 	mtx_lock(&devsoftc.mtx);
608 	if (devctl_queue_length == 0) {
609 		mtx_unlock(&devsoftc.mtx);
610 		free(n1->dei_data, M_BUS);
611 		free(n1, M_BUS);
612 		return;
613 	}
614 	/* Leave at least one spot in the queue... */
615 	while (devsoftc.queued > devctl_queue_length - 1) {
616 		n2 = TAILQ_FIRST(&devsoftc.devq);
617 		TAILQ_REMOVE(&devsoftc.devq, n2, dei_link);
618 		free(n2->dei_data, M_BUS);
619 		free(n2, M_BUS);
620 		devsoftc.queued--;
621 	}
622 	TAILQ_INSERT_TAIL(&devsoftc.devq, n1, dei_link);
623 	devsoftc.queued++;
624 	cv_broadcast(&devsoftc.cv);
625 	KNOTE_LOCKED(&devsoftc.sel.si_note, 0);
626 	mtx_unlock(&devsoftc.mtx);
627 	selwakeup(&devsoftc.sel);
628 	if (devsoftc.async && devsoftc.sigio != NULL)
629 		pgsigio(&devsoftc.sigio, SIGIO, 0);
630 	return;
631 out:
632 	/*
633 	 * We have to free data on all error paths since the caller
634 	 * assumes it will be free'd when this item is dequeued.
635 	 */
636 	free(data, M_BUS);
637 	return;
638 }
639 
640 void
641 devctl_queue_data(char *data)
642 {
643 
644 	devctl_queue_data_f(data, M_NOWAIT);
645 }
646 
647 /**
648  * @brief Send a 'notification' to userland, using standard ways
649  */
650 void
651 devctl_notify_f(const char *system, const char *subsystem, const char *type,
652     const char *data, int flags)
653 {
654 	int len = 0;
655 	char *msg;
656 
657 	if (system == NULL)
658 		return;		/* BOGUS!  Must specify system. */
659 	if (subsystem == NULL)
660 		return;		/* BOGUS!  Must specify subsystem. */
661 	if (type == NULL)
662 		return;		/* BOGUS!  Must specify type. */
663 	len += strlen(" system=") + strlen(system);
664 	len += strlen(" subsystem=") + strlen(subsystem);
665 	len += strlen(" type=") + strlen(type);
666 	/* add in the data message plus newline. */
667 	if (data != NULL)
668 		len += strlen(data);
669 	len += 3;	/* '!', '\n', and NUL */
670 	msg = malloc(len, M_BUS, flags);
671 	if (msg == NULL)
672 		return;		/* Drop it on the floor */
673 	if (data != NULL)
674 		snprintf(msg, len, "!system=%s subsystem=%s type=%s %s\n",
675 		    system, subsystem, type, data);
676 	else
677 		snprintf(msg, len, "!system=%s subsystem=%s type=%s\n",
678 		    system, subsystem, type);
679 	devctl_queue_data_f(msg, flags);
680 }
681 
682 void
683 devctl_notify(const char *system, const char *subsystem, const char *type,
684     const char *data)
685 {
686 
687 	devctl_notify_f(system, subsystem, type, data, M_NOWAIT);
688 }
689 
690 /*
691  * Common routine that tries to make sending messages as easy as possible.
692  * We allocate memory for the data, copy strings into that, but do not
693  * free it unless there's an error.  The dequeue part of the driver should
694  * free the data.  We don't send data when the device is disabled.  We do
695  * send data, even when we have no listeners, because we wish to avoid
696  * races relating to startup and restart of listening applications.
697  *
698  * devaddq is designed to string together the type of event, with the
699  * object of that event, plus the plug and play info and location info
700  * for that event.  This is likely most useful for devices, but less
701  * useful for other consumers of this interface.  Those should use
702  * the devctl_queue_data() interface instead.
703  */
704 static void
705 devaddq(const char *type, const char *what, device_t dev)
706 {
707 	char *data = NULL;
708 	char *loc = NULL;
709 	char *pnp = NULL;
710 	const char *parstr;
711 
712 	if (!devctl_queue_length)/* Rare race, but lost races safely discard */
713 		return;
714 	data = malloc(1024, M_BUS, M_NOWAIT);
715 	if (data == NULL)
716 		goto bad;
717 
718 	/* get the bus specific location of this device */
719 	loc = malloc(1024, M_BUS, M_NOWAIT);
720 	if (loc == NULL)
721 		goto bad;
722 	*loc = '\0';
723 	bus_child_location_str(dev, loc, 1024);
724 
725 	/* Get the bus specific pnp info of this device */
726 	pnp = malloc(1024, M_BUS, M_NOWAIT);
727 	if (pnp == NULL)
728 		goto bad;
729 	*pnp = '\0';
730 	bus_child_pnpinfo_str(dev, pnp, 1024);
731 
732 	/* Get the parent of this device, or / if high enough in the tree. */
733 	if (device_get_parent(dev) == NULL)
734 		parstr = ".";	/* Or '/' ? */
735 	else
736 		parstr = device_get_nameunit(device_get_parent(dev));
737 	/* String it all together. */
738 	snprintf(data, 1024, "%s%s at %s %s on %s\n", type, what, loc, pnp,
739 	  parstr);
740 	free(loc, M_BUS);
741 	free(pnp, M_BUS);
742 	devctl_queue_data(data);
743 	return;
744 bad:
745 	free(pnp, M_BUS);
746 	free(loc, M_BUS);
747 	free(data, M_BUS);
748 	return;
749 }
750 
751 /*
752  * A device was added to the tree.  We are called just after it successfully
753  * attaches (that is, probe and attach success for this device).  No call
754  * is made if a device is merely parented into the tree.  See devnomatch
755  * if probe fails.  If attach fails, no notification is sent (but maybe
756  * we should have a different message for this).
757  */
758 static void
759 devadded(device_t dev)
760 {
761 	devaddq("+", device_get_nameunit(dev), dev);
762 }
763 
764 /*
765  * A device was removed from the tree.  We are called just before this
766  * happens.
767  */
768 static void
769 devremoved(device_t dev)
770 {
771 	devaddq("-", device_get_nameunit(dev), dev);
772 }
773 
774 /*
775  * Called when there's no match for this device.  This is only called
776  * the first time that no match happens, so we don't keep getting this
777  * message.  Should that prove to be undesirable, we can change it.
778  * This is called when all drivers that can attach to a given bus
779  * decline to accept this device.  Other errors may not be detected.
780  */
781 static void
782 devnomatch(device_t dev)
783 {
784 	devaddq("?", "", dev);
785 }
786 
787 static int
788 sysctl_devctl_disable(SYSCTL_HANDLER_ARGS)
789 {
790 	struct dev_event_info *n1;
791 	int dis, error;
792 
793 	dis = (devctl_queue_length == 0);
794 	error = sysctl_handle_int(oidp, &dis, 0, req);
795 	if (error || !req->newptr)
796 		return (error);
797 	if (mtx_initialized(&devsoftc.mtx))
798 		mtx_lock(&devsoftc.mtx);
799 	if (dis) {
800 		while (!TAILQ_EMPTY(&devsoftc.devq)) {
801 			n1 = TAILQ_FIRST(&devsoftc.devq);
802 			TAILQ_REMOVE(&devsoftc.devq, n1, dei_link);
803 			free(n1->dei_data, M_BUS);
804 			free(n1, M_BUS);
805 		}
806 		devsoftc.queued = 0;
807 		devctl_queue_length = 0;
808 	} else {
809 		devctl_queue_length = DEVCTL_DEFAULT_QUEUE_LEN;
810 	}
811 	if (mtx_initialized(&devsoftc.mtx))
812 		mtx_unlock(&devsoftc.mtx);
813 	return (0);
814 }
815 
816 static int
817 sysctl_devctl_queue(SYSCTL_HANDLER_ARGS)
818 {
819 	struct dev_event_info *n1;
820 	int q, error;
821 
822 	q = devctl_queue_length;
823 	error = sysctl_handle_int(oidp, &q, 0, req);
824 	if (error || !req->newptr)
825 		return (error);
826 	if (q < 0)
827 		return (EINVAL);
828 	if (mtx_initialized(&devsoftc.mtx))
829 		mtx_lock(&devsoftc.mtx);
830 	devctl_queue_length = q;
831 	while (devsoftc.queued > devctl_queue_length) {
832 		n1 = TAILQ_FIRST(&devsoftc.devq);
833 		TAILQ_REMOVE(&devsoftc.devq, n1, dei_link);
834 		free(n1->dei_data, M_BUS);
835 		free(n1, M_BUS);
836 		devsoftc.queued--;
837 	}
838 	if (mtx_initialized(&devsoftc.mtx))
839 		mtx_unlock(&devsoftc.mtx);
840 	return (0);
841 }
842 
843 /* End of /dev/devctl code */
844 
845 static TAILQ_HEAD(,device)	bus_data_devices;
846 static int bus_data_generation = 1;
847 
848 static kobj_method_t null_methods[] = {
849 	KOBJMETHOD_END
850 };
851 
852 DEFINE_CLASS(null, null_methods, 0);
853 
854 /*
855  * Bus pass implementation
856  */
857 
858 static driver_list_t passes = TAILQ_HEAD_INITIALIZER(passes);
859 int bus_current_pass = BUS_PASS_ROOT;
860 
861 /**
862  * @internal
863  * @brief Register the pass level of a new driver attachment
864  *
865  * Register a new driver attachment's pass level.  If no driver
866  * attachment with the same pass level has been added, then @p new
867  * will be added to the global passes list.
868  *
869  * @param new		the new driver attachment
870  */
871 static void
872 driver_register_pass(struct driverlink *new)
873 {
874 	struct driverlink *dl;
875 
876 	/* We only consider pass numbers during boot. */
877 	if (bus_current_pass == BUS_PASS_DEFAULT)
878 		return;
879 
880 	/*
881 	 * Walk the passes list.  If we already know about this pass
882 	 * then there is nothing to do.  If we don't, then insert this
883 	 * driver link into the list.
884 	 */
885 	TAILQ_FOREACH(dl, &passes, passlink) {
886 		if (dl->pass < new->pass)
887 			continue;
888 		if (dl->pass == new->pass)
889 			return;
890 		TAILQ_INSERT_BEFORE(dl, new, passlink);
891 		return;
892 	}
893 	TAILQ_INSERT_TAIL(&passes, new, passlink);
894 }
895 
896 /**
897  * @brief Raise the current bus pass
898  *
899  * Raise the current bus pass level to @p pass.  Call the BUS_NEW_PASS()
900  * method on the root bus to kick off a new device tree scan for each
901  * new pass level that has at least one driver.
902  */
903 void
904 bus_set_pass(int pass)
905 {
906 	struct driverlink *dl;
907 
908 	if (bus_current_pass > pass)
909 		panic("Attempt to lower bus pass level");
910 
911 	TAILQ_FOREACH(dl, &passes, passlink) {
912 		/* Skip pass values below the current pass level. */
913 		if (dl->pass <= bus_current_pass)
914 			continue;
915 
916 		/*
917 		 * Bail once we hit a driver with a pass level that is
918 		 * too high.
919 		 */
920 		if (dl->pass > pass)
921 			break;
922 
923 		/*
924 		 * Raise the pass level to the next level and rescan
925 		 * the tree.
926 		 */
927 		bus_current_pass = dl->pass;
928 		BUS_NEW_PASS(root_bus);
929 	}
930 
931 	/*
932 	 * If there isn't a driver registered for the requested pass,
933 	 * then bus_current_pass might still be less than 'pass'.  Set
934 	 * it to 'pass' in that case.
935 	 */
936 	if (bus_current_pass < pass)
937 		bus_current_pass = pass;
938 	KASSERT(bus_current_pass == pass, ("Failed to update bus pass level"));
939 }
940 
941 /*
942  * Devclass implementation
943  */
944 
945 static devclass_list_t devclasses = TAILQ_HEAD_INITIALIZER(devclasses);
946 
947 /**
948  * @internal
949  * @brief Find or create a device class
950  *
951  * If a device class with the name @p classname exists, return it,
952  * otherwise if @p create is non-zero create and return a new device
953  * class.
954  *
955  * If @p parentname is non-NULL, the parent of the devclass is set to
956  * the devclass of that name.
957  *
958  * @param classname	the devclass name to find or create
959  * @param parentname	the parent devclass name or @c NULL
960  * @param create	non-zero to create a devclass
961  */
962 static devclass_t
963 devclass_find_internal(const char *classname, const char *parentname,
964 		       int create)
965 {
966 	devclass_t dc;
967 
968 	PDEBUG(("looking for %s", classname));
969 	if (!classname)
970 		return (NULL);
971 
972 	TAILQ_FOREACH(dc, &devclasses, link) {
973 		if (!strcmp(dc->name, classname))
974 			break;
975 	}
976 
977 	if (create && !dc) {
978 		PDEBUG(("creating %s", classname));
979 		dc = malloc(sizeof(struct devclass) + strlen(classname) + 1,
980 		    M_BUS, M_NOWAIT | M_ZERO);
981 		if (!dc)
982 			return (NULL);
983 		dc->parent = NULL;
984 		dc->name = (char*) (dc + 1);
985 		strcpy(dc->name, classname);
986 		TAILQ_INIT(&dc->drivers);
987 		TAILQ_INSERT_TAIL(&devclasses, dc, link);
988 
989 		bus_data_generation_update();
990 	}
991 
992 	/*
993 	 * If a parent class is specified, then set that as our parent so
994 	 * that this devclass will support drivers for the parent class as
995 	 * well.  If the parent class has the same name don't do this though
996 	 * as it creates a cycle that can trigger an infinite loop in
997 	 * device_probe_child() if a device exists for which there is no
998 	 * suitable driver.
999 	 */
1000 	if (parentname && dc && !dc->parent &&
1001 	    strcmp(classname, parentname) != 0) {
1002 		dc->parent = devclass_find_internal(parentname, NULL, TRUE);
1003 		dc->parent->flags |= DC_HAS_CHILDREN;
1004 	}
1005 
1006 	return (dc);
1007 }
1008 
1009 /**
1010  * @brief Create a device class
1011  *
1012  * If a device class with the name @p classname exists, return it,
1013  * otherwise create and return a new device class.
1014  *
1015  * @param classname	the devclass name to find or create
1016  */
1017 devclass_t
1018 devclass_create(const char *classname)
1019 {
1020 	return (devclass_find_internal(classname, NULL, TRUE));
1021 }
1022 
1023 /**
1024  * @brief Find a device class
1025  *
1026  * If a device class with the name @p classname exists, return it,
1027  * otherwise return @c NULL.
1028  *
1029  * @param classname	the devclass name to find
1030  */
1031 devclass_t
1032 devclass_find(const char *classname)
1033 {
1034 	return (devclass_find_internal(classname, NULL, FALSE));
1035 }
1036 
1037 /**
1038  * @brief Register that a device driver has been added to a devclass
1039  *
1040  * Register that a device driver has been added to a devclass.  This
1041  * is called by devclass_add_driver to accomplish the recursive
1042  * notification of all the children classes of dc, as well as dc.
1043  * Each layer will have BUS_DRIVER_ADDED() called for all instances of
1044  * the devclass.
1045  *
1046  * We do a full search here of the devclass list at each iteration
1047  * level to save storing children-lists in the devclass structure.  If
1048  * we ever move beyond a few dozen devices doing this, we may need to
1049  * reevaluate...
1050  *
1051  * @param dc		the devclass to edit
1052  * @param driver	the driver that was just added
1053  */
1054 static void
1055 devclass_driver_added(devclass_t dc, driver_t *driver)
1056 {
1057 	devclass_t parent;
1058 	int i;
1059 
1060 	/*
1061 	 * Call BUS_DRIVER_ADDED for any existing busses in this class.
1062 	 */
1063 	for (i = 0; i < dc->maxunit; i++)
1064 		if (dc->devices[i] && device_is_attached(dc->devices[i]))
1065 			BUS_DRIVER_ADDED(dc->devices[i], driver);
1066 
1067 	/*
1068 	 * Walk through the children classes.  Since we only keep a
1069 	 * single parent pointer around, we walk the entire list of
1070 	 * devclasses looking for children.  We set the
1071 	 * DC_HAS_CHILDREN flag when a child devclass is created on
1072 	 * the parent, so we only walk the list for those devclasses
1073 	 * that have children.
1074 	 */
1075 	if (!(dc->flags & DC_HAS_CHILDREN))
1076 		return;
1077 	parent = dc;
1078 	TAILQ_FOREACH(dc, &devclasses, link) {
1079 		if (dc->parent == parent)
1080 			devclass_driver_added(dc, driver);
1081 	}
1082 }
1083 
1084 /**
1085  * @brief Add a device driver to a device class
1086  *
1087  * Add a device driver to a devclass. This is normally called
1088  * automatically by DRIVER_MODULE(). The BUS_DRIVER_ADDED() method of
1089  * all devices in the devclass will be called to allow them to attempt
1090  * to re-probe any unmatched children.
1091  *
1092  * @param dc		the devclass to edit
1093  * @param driver	the driver to register
1094  */
1095 int
1096 devclass_add_driver(devclass_t dc, driver_t *driver, int pass, devclass_t *dcp)
1097 {
1098 	driverlink_t dl;
1099 	const char *parentname;
1100 
1101 	PDEBUG(("%s", DRIVERNAME(driver)));
1102 
1103 	/* Don't allow invalid pass values. */
1104 	if (pass <= BUS_PASS_ROOT)
1105 		return (EINVAL);
1106 
1107 	dl = malloc(sizeof *dl, M_BUS, M_NOWAIT|M_ZERO);
1108 	if (!dl)
1109 		return (ENOMEM);
1110 
1111 	/*
1112 	 * Compile the driver's methods. Also increase the reference count
1113 	 * so that the class doesn't get freed when the last instance
1114 	 * goes. This means we can safely use static methods and avoids a
1115 	 * double-free in devclass_delete_driver.
1116 	 */
1117 	kobj_class_compile((kobj_class_t) driver);
1118 
1119 	/*
1120 	 * If the driver has any base classes, make the
1121 	 * devclass inherit from the devclass of the driver's
1122 	 * first base class. This will allow the system to
1123 	 * search for drivers in both devclasses for children
1124 	 * of a device using this driver.
1125 	 */
1126 	if (driver->baseclasses)
1127 		parentname = driver->baseclasses[0]->name;
1128 	else
1129 		parentname = NULL;
1130 	*dcp = devclass_find_internal(driver->name, parentname, TRUE);
1131 
1132 	dl->driver = driver;
1133 	TAILQ_INSERT_TAIL(&dc->drivers, dl, link);
1134 	driver->refs++;		/* XXX: kobj_mtx */
1135 	dl->pass = pass;
1136 	driver_register_pass(dl);
1137 
1138 	devclass_driver_added(dc, driver);
1139 	bus_data_generation_update();
1140 	return (0);
1141 }
1142 
1143 /**
1144  * @brief Register that a device driver has been deleted from a devclass
1145  *
1146  * Register that a device driver has been removed from a devclass.
1147  * This is called by devclass_delete_driver to accomplish the
1148  * recursive notification of all the children classes of busclass, as
1149  * well as busclass.  Each layer will attempt to detach the driver
1150  * from any devices that are children of the bus's devclass.  The function
1151  * will return an error if a device fails to detach.
1152  *
1153  * We do a full search here of the devclass list at each iteration
1154  * level to save storing children-lists in the devclass structure.  If
1155  * we ever move beyond a few dozen devices doing this, we may need to
1156  * reevaluate...
1157  *
1158  * @param busclass	the devclass of the parent bus
1159  * @param dc		the devclass of the driver being deleted
1160  * @param driver	the driver being deleted
1161  */
1162 static int
1163 devclass_driver_deleted(devclass_t busclass, devclass_t dc, driver_t *driver)
1164 {
1165 	devclass_t parent;
1166 	device_t dev;
1167 	int error, i;
1168 
1169 	/*
1170 	 * Disassociate from any devices.  We iterate through all the
1171 	 * devices in the devclass of the driver and detach any which are
1172 	 * using the driver and which have a parent in the devclass which
1173 	 * we are deleting from.
1174 	 *
1175 	 * Note that since a driver can be in multiple devclasses, we
1176 	 * should not detach devices which are not children of devices in
1177 	 * the affected devclass.
1178 	 */
1179 	for (i = 0; i < dc->maxunit; i++) {
1180 		if (dc->devices[i]) {
1181 			dev = dc->devices[i];
1182 			if (dev->driver == driver && dev->parent &&
1183 			    dev->parent->devclass == busclass) {
1184 				if ((error = device_detach(dev)) != 0)
1185 					return (error);
1186 				BUS_PROBE_NOMATCH(dev->parent, dev);
1187 				devnomatch(dev);
1188 				dev->flags |= DF_DONENOMATCH;
1189 			}
1190 		}
1191 	}
1192 
1193 	/*
1194 	 * Walk through the children classes.  Since we only keep a
1195 	 * single parent pointer around, we walk the entire list of
1196 	 * devclasses looking for children.  We set the
1197 	 * DC_HAS_CHILDREN flag when a child devclass is created on
1198 	 * the parent, so we only walk the list for those devclasses
1199 	 * that have children.
1200 	 */
1201 	if (!(busclass->flags & DC_HAS_CHILDREN))
1202 		return (0);
1203 	parent = busclass;
1204 	TAILQ_FOREACH(busclass, &devclasses, link) {
1205 		if (busclass->parent == parent) {
1206 			error = devclass_driver_deleted(busclass, dc, driver);
1207 			if (error)
1208 				return (error);
1209 		}
1210 	}
1211 	return (0);
1212 }
1213 
1214 /**
1215  * @brief Delete a device driver from a device class
1216  *
1217  * Delete a device driver from a devclass. This is normally called
1218  * automatically by DRIVER_MODULE().
1219  *
1220  * If the driver is currently attached to any devices,
1221  * devclass_delete_driver() will first attempt to detach from each
1222  * device. If one of the detach calls fails, the driver will not be
1223  * deleted.
1224  *
1225  * @param dc		the devclass to edit
1226  * @param driver	the driver to unregister
1227  */
1228 int
1229 devclass_delete_driver(devclass_t busclass, driver_t *driver)
1230 {
1231 	devclass_t dc = devclass_find(driver->name);
1232 	driverlink_t dl;
1233 	int error;
1234 
1235 	PDEBUG(("%s from devclass %s", driver->name, DEVCLANAME(busclass)));
1236 
1237 	if (!dc)
1238 		return (0);
1239 
1240 	/*
1241 	 * Find the link structure in the bus' list of drivers.
1242 	 */
1243 	TAILQ_FOREACH(dl, &busclass->drivers, link) {
1244 		if (dl->driver == driver)
1245 			break;
1246 	}
1247 
1248 	if (!dl) {
1249 		PDEBUG(("%s not found in %s list", driver->name,
1250 		    busclass->name));
1251 		return (ENOENT);
1252 	}
1253 
1254 	error = devclass_driver_deleted(busclass, dc, driver);
1255 	if (error != 0)
1256 		return (error);
1257 
1258 	TAILQ_REMOVE(&busclass->drivers, dl, link);
1259 	free(dl, M_BUS);
1260 
1261 	/* XXX: kobj_mtx */
1262 	driver->refs--;
1263 	if (driver->refs == 0)
1264 		kobj_class_free((kobj_class_t) driver);
1265 
1266 	bus_data_generation_update();
1267 	return (0);
1268 }
1269 
1270 /**
1271  * @brief Quiesces a set of device drivers from a device class
1272  *
1273  * Quiesce a device driver from a devclass. This is normally called
1274  * automatically by DRIVER_MODULE().
1275  *
1276  * If the driver is currently attached to any devices,
1277  * devclass_quiesece_driver() will first attempt to quiesce each
1278  * device.
1279  *
1280  * @param dc		the devclass to edit
1281  * @param driver	the driver to unregister
1282  */
1283 static int
1284 devclass_quiesce_driver(devclass_t busclass, driver_t *driver)
1285 {
1286 	devclass_t dc = devclass_find(driver->name);
1287 	driverlink_t dl;
1288 	device_t dev;
1289 	int i;
1290 	int error;
1291 
1292 	PDEBUG(("%s from devclass %s", driver->name, DEVCLANAME(busclass)));
1293 
1294 	if (!dc)
1295 		return (0);
1296 
1297 	/*
1298 	 * Find the link structure in the bus' list of drivers.
1299 	 */
1300 	TAILQ_FOREACH(dl, &busclass->drivers, link) {
1301 		if (dl->driver == driver)
1302 			break;
1303 	}
1304 
1305 	if (!dl) {
1306 		PDEBUG(("%s not found in %s list", driver->name,
1307 		    busclass->name));
1308 		return (ENOENT);
1309 	}
1310 
1311 	/*
1312 	 * Quiesce all devices.  We iterate through all the devices in
1313 	 * the devclass of the driver and quiesce any which are using
1314 	 * the driver and which have a parent in the devclass which we
1315 	 * are quiescing.
1316 	 *
1317 	 * Note that since a driver can be in multiple devclasses, we
1318 	 * should not quiesce devices which are not children of
1319 	 * devices in the affected devclass.
1320 	 */
1321 	for (i = 0; i < dc->maxunit; i++) {
1322 		if (dc->devices[i]) {
1323 			dev = dc->devices[i];
1324 			if (dev->driver == driver && dev->parent &&
1325 			    dev->parent->devclass == busclass) {
1326 				if ((error = device_quiesce(dev)) != 0)
1327 					return (error);
1328 			}
1329 		}
1330 	}
1331 
1332 	return (0);
1333 }
1334 
1335 /**
1336  * @internal
1337  */
1338 static driverlink_t
1339 devclass_find_driver_internal(devclass_t dc, const char *classname)
1340 {
1341 	driverlink_t dl;
1342 
1343 	PDEBUG(("%s in devclass %s", classname, DEVCLANAME(dc)));
1344 
1345 	TAILQ_FOREACH(dl, &dc->drivers, link) {
1346 		if (!strcmp(dl->driver->name, classname))
1347 			return (dl);
1348 	}
1349 
1350 	PDEBUG(("not found"));
1351 	return (NULL);
1352 }
1353 
1354 /**
1355  * @brief Return the name of the devclass
1356  */
1357 const char *
1358 devclass_get_name(devclass_t dc)
1359 {
1360 	return (dc->name);
1361 }
1362 
1363 /**
1364  * @brief Find a device given a unit number
1365  *
1366  * @param dc		the devclass to search
1367  * @param unit		the unit number to search for
1368  *
1369  * @returns		the device with the given unit number or @c
1370  *			NULL if there is no such device
1371  */
1372 device_t
1373 devclass_get_device(devclass_t dc, int unit)
1374 {
1375 	if (dc == NULL || unit < 0 || unit >= dc->maxunit)
1376 		return (NULL);
1377 	return (dc->devices[unit]);
1378 }
1379 
1380 /**
1381  * @brief Find the softc field of a device given a unit number
1382  *
1383  * @param dc		the devclass to search
1384  * @param unit		the unit number to search for
1385  *
1386  * @returns		the softc field of the device with the given
1387  *			unit number or @c NULL if there is no such
1388  *			device
1389  */
1390 void *
1391 devclass_get_softc(devclass_t dc, int unit)
1392 {
1393 	device_t dev;
1394 
1395 	dev = devclass_get_device(dc, unit);
1396 	if (!dev)
1397 		return (NULL);
1398 
1399 	return (device_get_softc(dev));
1400 }
1401 
1402 /**
1403  * @brief Get a list of devices in the devclass
1404  *
1405  * An array containing a list of all the devices in the given devclass
1406  * is allocated and returned in @p *devlistp. The number of devices
1407  * in the array is returned in @p *devcountp. The caller should free
1408  * the array using @c free(p, M_TEMP), even if @p *devcountp is 0.
1409  *
1410  * @param dc		the devclass to examine
1411  * @param devlistp	points at location for array pointer return
1412  *			value
1413  * @param devcountp	points at location for array size return value
1414  *
1415  * @retval 0		success
1416  * @retval ENOMEM	the array allocation failed
1417  */
1418 int
1419 devclass_get_devices(devclass_t dc, device_t **devlistp, int *devcountp)
1420 {
1421 	int count, i;
1422 	device_t *list;
1423 
1424 	count = devclass_get_count(dc);
1425 	list = malloc(count * sizeof(device_t), M_TEMP, M_NOWAIT|M_ZERO);
1426 	if (!list)
1427 		return (ENOMEM);
1428 
1429 	count = 0;
1430 	for (i = 0; i < dc->maxunit; i++) {
1431 		if (dc->devices[i]) {
1432 			list[count] = dc->devices[i];
1433 			count++;
1434 		}
1435 	}
1436 
1437 	*devlistp = list;
1438 	*devcountp = count;
1439 
1440 	return (0);
1441 }
1442 
1443 /**
1444  * @brief Get a list of drivers in the devclass
1445  *
1446  * An array containing a list of pointers to all the drivers in the
1447  * given devclass is allocated and returned in @p *listp.  The number
1448  * of drivers in the array is returned in @p *countp. The caller should
1449  * free the array using @c free(p, M_TEMP).
1450  *
1451  * @param dc		the devclass to examine
1452  * @param listp		gives location for array pointer return value
1453  * @param countp	gives location for number of array elements
1454  *			return value
1455  *
1456  * @retval 0		success
1457  * @retval ENOMEM	the array allocation failed
1458  */
1459 int
1460 devclass_get_drivers(devclass_t dc, driver_t ***listp, int *countp)
1461 {
1462 	driverlink_t dl;
1463 	driver_t **list;
1464 	int count;
1465 
1466 	count = 0;
1467 	TAILQ_FOREACH(dl, &dc->drivers, link)
1468 		count++;
1469 	list = malloc(count * sizeof(driver_t *), M_TEMP, M_NOWAIT);
1470 	if (list == NULL)
1471 		return (ENOMEM);
1472 
1473 	count = 0;
1474 	TAILQ_FOREACH(dl, &dc->drivers, link) {
1475 		list[count] = dl->driver;
1476 		count++;
1477 	}
1478 	*listp = list;
1479 	*countp = count;
1480 
1481 	return (0);
1482 }
1483 
1484 /**
1485  * @brief Get the number of devices in a devclass
1486  *
1487  * @param dc		the devclass to examine
1488  */
1489 int
1490 devclass_get_count(devclass_t dc)
1491 {
1492 	int count, i;
1493 
1494 	count = 0;
1495 	for (i = 0; i < dc->maxunit; i++)
1496 		if (dc->devices[i])
1497 			count++;
1498 	return (count);
1499 }
1500 
1501 /**
1502  * @brief Get the maximum unit number used in a devclass
1503  *
1504  * Note that this is one greater than the highest currently-allocated
1505  * unit.  If a null devclass_t is passed in, -1 is returned to indicate
1506  * that not even the devclass has been allocated yet.
1507  *
1508  * @param dc		the devclass to examine
1509  */
1510 int
1511 devclass_get_maxunit(devclass_t dc)
1512 {
1513 	if (dc == NULL)
1514 		return (-1);
1515 	return (dc->maxunit);
1516 }
1517 
1518 /**
1519  * @brief Find a free unit number in a devclass
1520  *
1521  * This function searches for the first unused unit number greater
1522  * that or equal to @p unit.
1523  *
1524  * @param dc		the devclass to examine
1525  * @param unit		the first unit number to check
1526  */
1527 int
1528 devclass_find_free_unit(devclass_t dc, int unit)
1529 {
1530 	if (dc == NULL)
1531 		return (unit);
1532 	while (unit < dc->maxunit && dc->devices[unit] != NULL)
1533 		unit++;
1534 	return (unit);
1535 }
1536 
1537 /**
1538  * @brief Set the parent of a devclass
1539  *
1540  * The parent class is normally initialised automatically by
1541  * DRIVER_MODULE().
1542  *
1543  * @param dc		the devclass to edit
1544  * @param pdc		the new parent devclass
1545  */
1546 void
1547 devclass_set_parent(devclass_t dc, devclass_t pdc)
1548 {
1549 	dc->parent = pdc;
1550 }
1551 
1552 /**
1553  * @brief Get the parent of a devclass
1554  *
1555  * @param dc		the devclass to examine
1556  */
1557 devclass_t
1558 devclass_get_parent(devclass_t dc)
1559 {
1560 	return (dc->parent);
1561 }
1562 
1563 struct sysctl_ctx_list *
1564 devclass_get_sysctl_ctx(devclass_t dc)
1565 {
1566 	return (&dc->sysctl_ctx);
1567 }
1568 
1569 struct sysctl_oid *
1570 devclass_get_sysctl_tree(devclass_t dc)
1571 {
1572 	return (dc->sysctl_tree);
1573 }
1574 
1575 /**
1576  * @internal
1577  * @brief Allocate a unit number
1578  *
1579  * On entry, @p *unitp is the desired unit number (or @c -1 if any
1580  * will do). The allocated unit number is returned in @p *unitp.
1581 
1582  * @param dc		the devclass to allocate from
1583  * @param unitp		points at the location for the allocated unit
1584  *			number
1585  *
1586  * @retval 0		success
1587  * @retval EEXIST	the requested unit number is already allocated
1588  * @retval ENOMEM	memory allocation failure
1589  */
1590 static int
1591 devclass_alloc_unit(devclass_t dc, device_t dev, int *unitp)
1592 {
1593 	const char *s;
1594 	int unit = *unitp;
1595 
1596 	PDEBUG(("unit %d in devclass %s", unit, DEVCLANAME(dc)));
1597 
1598 	/* Ask the parent bus if it wants to wire this device. */
1599 	if (unit == -1)
1600 		BUS_HINT_DEVICE_UNIT(device_get_parent(dev), dev, dc->name,
1601 		    &unit);
1602 
1603 	/* If we were given a wired unit number, check for existing device */
1604 	/* XXX imp XXX */
1605 	if (unit != -1) {
1606 		if (unit >= 0 && unit < dc->maxunit &&
1607 		    dc->devices[unit] != NULL) {
1608 			if (bootverbose)
1609 				printf("%s: %s%d already exists; skipping it\n",
1610 				    dc->name, dc->name, *unitp);
1611 			return (EEXIST);
1612 		}
1613 	} else {
1614 		/* Unwired device, find the next available slot for it */
1615 		unit = 0;
1616 		for (unit = 0;; unit++) {
1617 			/* If there is an "at" hint for a unit then skip it. */
1618 			if (resource_string_value(dc->name, unit, "at", &s) ==
1619 			    0)
1620 				continue;
1621 
1622 			/* If this device slot is already in use, skip it. */
1623 			if (unit < dc->maxunit && dc->devices[unit] != NULL)
1624 				continue;
1625 
1626 			break;
1627 		}
1628 	}
1629 
1630 	/*
1631 	 * We've selected a unit beyond the length of the table, so let's
1632 	 * extend the table to make room for all units up to and including
1633 	 * this one.
1634 	 */
1635 	if (unit >= dc->maxunit) {
1636 		device_t *newlist, *oldlist;
1637 		int newsize;
1638 
1639 		oldlist = dc->devices;
1640 		newsize = roundup((unit + 1), MINALLOCSIZE / sizeof(device_t));
1641 		newlist = malloc(sizeof(device_t) * newsize, M_BUS, M_NOWAIT);
1642 		if (!newlist)
1643 			return (ENOMEM);
1644 		if (oldlist != NULL)
1645 			bcopy(oldlist, newlist, sizeof(device_t) * dc->maxunit);
1646 		bzero(newlist + dc->maxunit,
1647 		    sizeof(device_t) * (newsize - dc->maxunit));
1648 		dc->devices = newlist;
1649 		dc->maxunit = newsize;
1650 		if (oldlist != NULL)
1651 			free(oldlist, M_BUS);
1652 	}
1653 	PDEBUG(("now: unit %d in devclass %s", unit, DEVCLANAME(dc)));
1654 
1655 	*unitp = unit;
1656 	return (0);
1657 }
1658 
1659 /**
1660  * @internal
1661  * @brief Add a device to a devclass
1662  *
1663  * A unit number is allocated for the device (using the device's
1664  * preferred unit number if any) and the device is registered in the
1665  * devclass. This allows the device to be looked up by its unit
1666  * number, e.g. by decoding a dev_t minor number.
1667  *
1668  * @param dc		the devclass to add to
1669  * @param dev		the device to add
1670  *
1671  * @retval 0		success
1672  * @retval EEXIST	the requested unit number is already allocated
1673  * @retval ENOMEM	memory allocation failure
1674  */
1675 static int
1676 devclass_add_device(devclass_t dc, device_t dev)
1677 {
1678 	int buflen, error;
1679 
1680 	PDEBUG(("%s in devclass %s", DEVICENAME(dev), DEVCLANAME(dc)));
1681 
1682 	buflen = snprintf(NULL, 0, "%s%d$", dc->name, INT_MAX);
1683 	if (buflen < 0)
1684 		return (ENOMEM);
1685 	dev->nameunit = malloc(buflen, M_BUS, M_NOWAIT|M_ZERO);
1686 	if (!dev->nameunit)
1687 		return (ENOMEM);
1688 
1689 	if ((error = devclass_alloc_unit(dc, dev, &dev->unit)) != 0) {
1690 		free(dev->nameunit, M_BUS);
1691 		dev->nameunit = NULL;
1692 		return (error);
1693 	}
1694 	dc->devices[dev->unit] = dev;
1695 	dev->devclass = dc;
1696 	snprintf(dev->nameunit, buflen, "%s%d", dc->name, dev->unit);
1697 
1698 	return (0);
1699 }
1700 
1701 /**
1702  * @internal
1703  * @brief Delete a device from a devclass
1704  *
1705  * The device is removed from the devclass's device list and its unit
1706  * number is freed.
1707 
1708  * @param dc		the devclass to delete from
1709  * @param dev		the device to delete
1710  *
1711  * @retval 0		success
1712  */
1713 static int
1714 devclass_delete_device(devclass_t dc, device_t dev)
1715 {
1716 	if (!dc || !dev)
1717 		return (0);
1718 
1719 	PDEBUG(("%s in devclass %s", DEVICENAME(dev), DEVCLANAME(dc)));
1720 
1721 	if (dev->devclass != dc || dc->devices[dev->unit] != dev)
1722 		panic("devclass_delete_device: inconsistent device class");
1723 	dc->devices[dev->unit] = NULL;
1724 	if (dev->flags & DF_WILDCARD)
1725 		dev->unit = -1;
1726 	dev->devclass = NULL;
1727 	free(dev->nameunit, M_BUS);
1728 	dev->nameunit = NULL;
1729 
1730 	return (0);
1731 }
1732 
1733 /**
1734  * @internal
1735  * @brief Make a new device and add it as a child of @p parent
1736  *
1737  * @param parent	the parent of the new device
1738  * @param name		the devclass name of the new device or @c NULL
1739  *			to leave the devclass unspecified
1740  * @parem unit		the unit number of the new device of @c -1 to
1741  *			leave the unit number unspecified
1742  *
1743  * @returns the new device
1744  */
1745 static device_t
1746 make_device(device_t parent, const char *name, int unit)
1747 {
1748 	device_t dev;
1749 	devclass_t dc;
1750 
1751 	PDEBUG(("%s at %s as unit %d", name, DEVICENAME(parent), unit));
1752 
1753 	if (name) {
1754 		dc = devclass_find_internal(name, NULL, TRUE);
1755 		if (!dc) {
1756 			printf("make_device: can't find device class %s\n",
1757 			    name);
1758 			return (NULL);
1759 		}
1760 	} else {
1761 		dc = NULL;
1762 	}
1763 
1764 	dev = malloc(sizeof(struct device), M_BUS, M_NOWAIT|M_ZERO);
1765 	if (!dev)
1766 		return (NULL);
1767 
1768 	dev->parent = parent;
1769 	TAILQ_INIT(&dev->children);
1770 	kobj_init((kobj_t) dev, &null_class);
1771 	dev->driver = NULL;
1772 	dev->devclass = NULL;
1773 	dev->unit = unit;
1774 	dev->nameunit = NULL;
1775 	dev->desc = NULL;
1776 	dev->busy = 0;
1777 	dev->devflags = 0;
1778 	dev->flags = DF_ENABLED;
1779 	dev->order = 0;
1780 	if (unit == -1)
1781 		dev->flags |= DF_WILDCARD;
1782 	if (name) {
1783 		dev->flags |= DF_FIXEDCLASS;
1784 		if (devclass_add_device(dc, dev)) {
1785 			kobj_delete((kobj_t) dev, M_BUS);
1786 			return (NULL);
1787 		}
1788 	}
1789 	dev->ivars = NULL;
1790 	dev->softc = NULL;
1791 
1792 	dev->state = DS_NOTPRESENT;
1793 
1794 	TAILQ_INSERT_TAIL(&bus_data_devices, dev, devlink);
1795 	bus_data_generation_update();
1796 
1797 	return (dev);
1798 }
1799 
1800 /**
1801  * @internal
1802  * @brief Print a description of a device.
1803  */
1804 static int
1805 device_print_child(device_t dev, device_t child)
1806 {
1807 	int retval = 0;
1808 
1809 	if (device_is_alive(child))
1810 		retval += BUS_PRINT_CHILD(dev, child);
1811 	else
1812 		retval += device_printf(child, " not found\n");
1813 
1814 	return (retval);
1815 }
1816 
1817 /**
1818  * @brief Create a new device
1819  *
1820  * This creates a new device and adds it as a child of an existing
1821  * parent device. The new device will be added after the last existing
1822  * child with order zero.
1823  *
1824  * @param dev		the device which will be the parent of the
1825  *			new child device
1826  * @param name		devclass name for new device or @c NULL if not
1827  *			specified
1828  * @param unit		unit number for new device or @c -1 if not
1829  *			specified
1830  *
1831  * @returns		the new device
1832  */
1833 device_t
1834 device_add_child(device_t dev, const char *name, int unit)
1835 {
1836 	return (device_add_child_ordered(dev, 0, name, unit));
1837 }
1838 
1839 /**
1840  * @brief Create a new device
1841  *
1842  * This creates a new device and adds it as a child of an existing
1843  * parent device. The new device will be added after the last existing
1844  * child with the same order.
1845  *
1846  * @param dev		the device which will be the parent of the
1847  *			new child device
1848  * @param order		a value which is used to partially sort the
1849  *			children of @p dev - devices created using
1850  *			lower values of @p order appear first in @p
1851  *			dev's list of children
1852  * @param name		devclass name for new device or @c NULL if not
1853  *			specified
1854  * @param unit		unit number for new device or @c -1 if not
1855  *			specified
1856  *
1857  * @returns		the new device
1858  */
1859 device_t
1860 device_add_child_ordered(device_t dev, u_int order, const char *name, int unit)
1861 {
1862 	device_t child;
1863 	device_t place;
1864 
1865 	PDEBUG(("%s at %s with order %u as unit %d",
1866 	    name, DEVICENAME(dev), order, unit));
1867 	KASSERT(name != NULL || unit == -1,
1868 	    ("child device with wildcard name and specific unit number"));
1869 
1870 	child = make_device(dev, name, unit);
1871 	if (child == NULL)
1872 		return (child);
1873 	child->order = order;
1874 
1875 	TAILQ_FOREACH(place, &dev->children, link) {
1876 		if (place->order > order)
1877 			break;
1878 	}
1879 
1880 	if (place) {
1881 		/*
1882 		 * The device 'place' is the first device whose order is
1883 		 * greater than the new child.
1884 		 */
1885 		TAILQ_INSERT_BEFORE(place, child, link);
1886 	} else {
1887 		/*
1888 		 * The new child's order is greater or equal to the order of
1889 		 * any existing device. Add the child to the tail of the list.
1890 		 */
1891 		TAILQ_INSERT_TAIL(&dev->children, child, link);
1892 	}
1893 
1894 	bus_data_generation_update();
1895 	return (child);
1896 }
1897 
1898 /**
1899  * @brief Delete a device
1900  *
1901  * This function deletes a device along with all of its children. If
1902  * the device currently has a driver attached to it, the device is
1903  * detached first using device_detach().
1904  *
1905  * @param dev		the parent device
1906  * @param child		the device to delete
1907  *
1908  * @retval 0		success
1909  * @retval non-zero	a unit error code describing the error
1910  */
1911 int
1912 device_delete_child(device_t dev, device_t child)
1913 {
1914 	int error;
1915 	device_t grandchild;
1916 
1917 	PDEBUG(("%s from %s", DEVICENAME(child), DEVICENAME(dev)));
1918 
1919 	/* remove children first */
1920 	while ((grandchild = TAILQ_FIRST(&child->children)) != NULL) {
1921 		error = device_delete_child(child, grandchild);
1922 		if (error)
1923 			return (error);
1924 	}
1925 
1926 	if ((error = device_detach(child)) != 0)
1927 		return (error);
1928 	if (child->devclass)
1929 		devclass_delete_device(child->devclass, child);
1930 	if (child->parent)
1931 		BUS_CHILD_DELETED(dev, child);
1932 	TAILQ_REMOVE(&dev->children, child, link);
1933 	TAILQ_REMOVE(&bus_data_devices, child, devlink);
1934 	kobj_delete((kobj_t) child, M_BUS);
1935 
1936 	bus_data_generation_update();
1937 	return (0);
1938 }
1939 
1940 /**
1941  * @brief Delete all children devices of the given device, if any.
1942  *
1943  * This function deletes all children devices of the given device, if
1944  * any, using the device_delete_child() function for each device it
1945  * finds. If a child device cannot be deleted, this function will
1946  * return an error code.
1947  *
1948  * @param dev		the parent device
1949  *
1950  * @retval 0		success
1951  * @retval non-zero	a device would not detach
1952  */
1953 int
1954 device_delete_children(device_t dev)
1955 {
1956 	device_t child;
1957 	int error;
1958 
1959 	PDEBUG(("Deleting all children of %s", DEVICENAME(dev)));
1960 
1961 	error = 0;
1962 
1963 	while ((child = TAILQ_FIRST(&dev->children)) != NULL) {
1964 		error = device_delete_child(dev, child);
1965 		if (error) {
1966 			PDEBUG(("Failed deleting %s", DEVICENAME(child)));
1967 			break;
1968 		}
1969 	}
1970 	return (error);
1971 }
1972 
1973 /**
1974  * @brief Find a device given a unit number
1975  *
1976  * This is similar to devclass_get_devices() but only searches for
1977  * devices which have @p dev as a parent.
1978  *
1979  * @param dev		the parent device to search
1980  * @param unit		the unit number to search for.  If the unit is -1,
1981  *			return the first child of @p dev which has name
1982  *			@p classname (that is, the one with the lowest unit.)
1983  *
1984  * @returns		the device with the given unit number or @c
1985  *			NULL if there is no such device
1986  */
1987 device_t
1988 device_find_child(device_t dev, const char *classname, int unit)
1989 {
1990 	devclass_t dc;
1991 	device_t child;
1992 
1993 	dc = devclass_find(classname);
1994 	if (!dc)
1995 		return (NULL);
1996 
1997 	if (unit != -1) {
1998 		child = devclass_get_device(dc, unit);
1999 		if (child && child->parent == dev)
2000 			return (child);
2001 	} else {
2002 		for (unit = 0; unit < devclass_get_maxunit(dc); unit++) {
2003 			child = devclass_get_device(dc, unit);
2004 			if (child && child->parent == dev)
2005 				return (child);
2006 		}
2007 	}
2008 	return (NULL);
2009 }
2010 
2011 /**
2012  * @internal
2013  */
2014 static driverlink_t
2015 first_matching_driver(devclass_t dc, device_t dev)
2016 {
2017 	if (dev->devclass)
2018 		return (devclass_find_driver_internal(dc, dev->devclass->name));
2019 	return (TAILQ_FIRST(&dc->drivers));
2020 }
2021 
2022 /**
2023  * @internal
2024  */
2025 static driverlink_t
2026 next_matching_driver(devclass_t dc, device_t dev, driverlink_t last)
2027 {
2028 	if (dev->devclass) {
2029 		driverlink_t dl;
2030 		for (dl = TAILQ_NEXT(last, link); dl; dl = TAILQ_NEXT(dl, link))
2031 			if (!strcmp(dev->devclass->name, dl->driver->name))
2032 				return (dl);
2033 		return (NULL);
2034 	}
2035 	return (TAILQ_NEXT(last, link));
2036 }
2037 
2038 /**
2039  * @internal
2040  */
2041 int
2042 device_probe_child(device_t dev, device_t child)
2043 {
2044 	devclass_t dc;
2045 	driverlink_t best = NULL;
2046 	driverlink_t dl;
2047 	int result, pri = 0;
2048 	int hasclass = (child->devclass != NULL);
2049 
2050 	GIANT_REQUIRED;
2051 
2052 	dc = dev->devclass;
2053 	if (!dc)
2054 		panic("device_probe_child: parent device has no devclass");
2055 
2056 	/*
2057 	 * If the state is already probed, then return.  However, don't
2058 	 * return if we can rebid this object.
2059 	 */
2060 	if (child->state == DS_ALIVE && (child->flags & DF_REBID) == 0)
2061 		return (0);
2062 
2063 	for (; dc; dc = dc->parent) {
2064 		for (dl = first_matching_driver(dc, child);
2065 		     dl;
2066 		     dl = next_matching_driver(dc, child, dl)) {
2067 			/* If this driver's pass is too high, then ignore it. */
2068 			if (dl->pass > bus_current_pass)
2069 				continue;
2070 
2071 			PDEBUG(("Trying %s", DRIVERNAME(dl->driver)));
2072 			result = device_set_driver(child, dl->driver);
2073 			if (result == ENOMEM)
2074 				return (result);
2075 			else if (result != 0)
2076 				continue;
2077 			if (!hasclass) {
2078 				if (device_set_devclass(child,
2079 				    dl->driver->name) != 0) {
2080 					char const * devname =
2081 					    device_get_name(child);
2082 					if (devname == NULL)
2083 						devname = "(unknown)";
2084 					printf("driver bug: Unable to set "
2085 					    "devclass (class: %s "
2086 					    "devname: %s)\n",
2087 					    dl->driver->name,
2088 					    devname);
2089 					(void)device_set_driver(child, NULL);
2090 					continue;
2091 				}
2092 			}
2093 
2094 			/* Fetch any flags for the device before probing. */
2095 			resource_int_value(dl->driver->name, child->unit,
2096 			    "flags", &child->devflags);
2097 
2098 			result = DEVICE_PROBE(child);
2099 
2100 			/* Reset flags and devclass before the next probe. */
2101 			child->devflags = 0;
2102 			if (!hasclass)
2103 				(void)device_set_devclass(child, NULL);
2104 
2105 			/*
2106 			 * If the driver returns SUCCESS, there can be
2107 			 * no higher match for this device.
2108 			 */
2109 			if (result == 0) {
2110 				best = dl;
2111 				pri = 0;
2112 				break;
2113 			}
2114 
2115 			/*
2116 			 * Probes that return BUS_PROBE_NOWILDCARD or lower
2117 			 * only match on devices whose driver was explicitly
2118 			 * specified.
2119 			 */
2120 			if (result <= BUS_PROBE_NOWILDCARD &&
2121 			    !(child->flags & DF_FIXEDCLASS)) {
2122 				result = ENXIO;
2123 			}
2124 
2125 			/*
2126 			 * The driver returned an error so it
2127 			 * certainly doesn't match.
2128 			 */
2129 			if (result > 0) {
2130 				(void)device_set_driver(child, NULL);
2131 				continue;
2132 			}
2133 
2134 			/*
2135 			 * A priority lower than SUCCESS, remember the
2136 			 * best matching driver. Initialise the value
2137 			 * of pri for the first match.
2138 			 */
2139 			if (best == NULL || result > pri) {
2140 				best = dl;
2141 				pri = result;
2142 				continue;
2143 			}
2144 		}
2145 		/*
2146 		 * If we have an unambiguous match in this devclass,
2147 		 * don't look in the parent.
2148 		 */
2149 		if (best && pri == 0)
2150 			break;
2151 	}
2152 
2153 	/*
2154 	 * If we found a driver, change state and initialise the devclass.
2155 	 */
2156 	/* XXX What happens if we rebid and got no best? */
2157 	if (best) {
2158 		/*
2159 		 * If this device was attached, and we were asked to
2160 		 * rescan, and it is a different driver, then we have
2161 		 * to detach the old driver and reattach this new one.
2162 		 * Note, we don't have to check for DF_REBID here
2163 		 * because if the state is > DS_ALIVE, we know it must
2164 		 * be.
2165 		 *
2166 		 * This assumes that all DF_REBID drivers can have
2167 		 * their probe routine called at any time and that
2168 		 * they are idempotent as well as completely benign in
2169 		 * normal operations.
2170 		 *
2171 		 * We also have to make sure that the detach
2172 		 * succeeded, otherwise we fail the operation (or
2173 		 * maybe it should just fail silently?  I'm torn).
2174 		 */
2175 		if (child->state > DS_ALIVE && best->driver != child->driver)
2176 			if ((result = device_detach(dev)) != 0)
2177 				return (result);
2178 
2179 		/* Set the winning driver, devclass, and flags. */
2180 		if (!child->devclass) {
2181 			result = device_set_devclass(child, best->driver->name);
2182 			if (result != 0)
2183 				return (result);
2184 		}
2185 		result = device_set_driver(child, best->driver);
2186 		if (result != 0)
2187 			return (result);
2188 		resource_int_value(best->driver->name, child->unit,
2189 		    "flags", &child->devflags);
2190 
2191 		if (pri < 0) {
2192 			/*
2193 			 * A bit bogus. Call the probe method again to make
2194 			 * sure that we have the right description.
2195 			 */
2196 			DEVICE_PROBE(child);
2197 #if 0
2198 			child->flags |= DF_REBID;
2199 #endif
2200 		} else
2201 			child->flags &= ~DF_REBID;
2202 		child->state = DS_ALIVE;
2203 
2204 		bus_data_generation_update();
2205 		return (0);
2206 	}
2207 
2208 	return (ENXIO);
2209 }
2210 
2211 /**
2212  * @brief Return the parent of a device
2213  */
2214 device_t
2215 device_get_parent(device_t dev)
2216 {
2217 	return (dev->parent);
2218 }
2219 
2220 /**
2221  * @brief Get a list of children of a device
2222  *
2223  * An array containing a list of all the children of the given device
2224  * is allocated and returned in @p *devlistp. The number of devices
2225  * in the array is returned in @p *devcountp. The caller should free
2226  * the array using @c free(p, M_TEMP).
2227  *
2228  * @param dev		the device to examine
2229  * @param devlistp	points at location for array pointer return
2230  *			value
2231  * @param devcountp	points at location for array size return value
2232  *
2233  * @retval 0		success
2234  * @retval ENOMEM	the array allocation failed
2235  */
2236 int
2237 device_get_children(device_t dev, device_t **devlistp, int *devcountp)
2238 {
2239 	int count;
2240 	device_t child;
2241 	device_t *list;
2242 
2243 	count = 0;
2244 	TAILQ_FOREACH(child, &dev->children, link) {
2245 		count++;
2246 	}
2247 	if (count == 0) {
2248 		*devlistp = NULL;
2249 		*devcountp = 0;
2250 		return (0);
2251 	}
2252 
2253 	list = malloc(count * sizeof(device_t), M_TEMP, M_NOWAIT|M_ZERO);
2254 	if (!list)
2255 		return (ENOMEM);
2256 
2257 	count = 0;
2258 	TAILQ_FOREACH(child, &dev->children, link) {
2259 		list[count] = child;
2260 		count++;
2261 	}
2262 
2263 	*devlistp = list;
2264 	*devcountp = count;
2265 
2266 	return (0);
2267 }
2268 
2269 /**
2270  * @brief Return the current driver for the device or @c NULL if there
2271  * is no driver currently attached
2272  */
2273 driver_t *
2274 device_get_driver(device_t dev)
2275 {
2276 	return (dev->driver);
2277 }
2278 
2279 /**
2280  * @brief Return the current devclass for the device or @c NULL if
2281  * there is none.
2282  */
2283 devclass_t
2284 device_get_devclass(device_t dev)
2285 {
2286 	return (dev->devclass);
2287 }
2288 
2289 /**
2290  * @brief Return the name of the device's devclass or @c NULL if there
2291  * is none.
2292  */
2293 const char *
2294 device_get_name(device_t dev)
2295 {
2296 	if (dev != NULL && dev->devclass)
2297 		return (devclass_get_name(dev->devclass));
2298 	return (NULL);
2299 }
2300 
2301 /**
2302  * @brief Return a string containing the device's devclass name
2303  * followed by an ascii representation of the device's unit number
2304  * (e.g. @c "foo2").
2305  */
2306 const char *
2307 device_get_nameunit(device_t dev)
2308 {
2309 	return (dev->nameunit);
2310 }
2311 
2312 /**
2313  * @brief Return the device's unit number.
2314  */
2315 int
2316 device_get_unit(device_t dev)
2317 {
2318 	return (dev->unit);
2319 }
2320 
2321 /**
2322  * @brief Return the device's description string
2323  */
2324 const char *
2325 device_get_desc(device_t dev)
2326 {
2327 	return (dev->desc);
2328 }
2329 
2330 /**
2331  * @brief Return the device's flags
2332  */
2333 uint32_t
2334 device_get_flags(device_t dev)
2335 {
2336 	return (dev->devflags);
2337 }
2338 
2339 struct sysctl_ctx_list *
2340 device_get_sysctl_ctx(device_t dev)
2341 {
2342 	return (&dev->sysctl_ctx);
2343 }
2344 
2345 struct sysctl_oid *
2346 device_get_sysctl_tree(device_t dev)
2347 {
2348 	return (dev->sysctl_tree);
2349 }
2350 
2351 /**
2352  * @brief Print the name of the device followed by a colon and a space
2353  *
2354  * @returns the number of characters printed
2355  */
2356 int
2357 device_print_prettyname(device_t dev)
2358 {
2359 	const char *name = device_get_name(dev);
2360 
2361 	if (name == NULL)
2362 		return (printf("unknown: "));
2363 	return (printf("%s%d: ", name, device_get_unit(dev)));
2364 }
2365 
2366 /**
2367  * @brief Print the name of the device followed by a colon, a space
2368  * and the result of calling vprintf() with the value of @p fmt and
2369  * the following arguments.
2370  *
2371  * @returns the number of characters printed
2372  */
2373 int
2374 device_printf(device_t dev, const char * fmt, ...)
2375 {
2376 	va_list ap;
2377 	int retval;
2378 
2379 	retval = device_print_prettyname(dev);
2380 	va_start(ap, fmt);
2381 	retval += vprintf(fmt, ap);
2382 	va_end(ap);
2383 	return (retval);
2384 }
2385 
2386 /**
2387  * @internal
2388  */
2389 static void
2390 device_set_desc_internal(device_t dev, const char* desc, int copy)
2391 {
2392 	if (dev->desc && (dev->flags & DF_DESCMALLOCED)) {
2393 		free(dev->desc, M_BUS);
2394 		dev->flags &= ~DF_DESCMALLOCED;
2395 		dev->desc = NULL;
2396 	}
2397 
2398 	if (copy && desc) {
2399 		dev->desc = malloc(strlen(desc) + 1, M_BUS, M_NOWAIT);
2400 		if (dev->desc) {
2401 			strcpy(dev->desc, desc);
2402 			dev->flags |= DF_DESCMALLOCED;
2403 		}
2404 	} else {
2405 		/* Avoid a -Wcast-qual warning */
2406 		dev->desc = (char *)(uintptr_t) desc;
2407 	}
2408 
2409 	bus_data_generation_update();
2410 }
2411 
2412 /**
2413  * @brief Set the device's description
2414  *
2415  * The value of @c desc should be a string constant that will not
2416  * change (at least until the description is changed in a subsequent
2417  * call to device_set_desc() or device_set_desc_copy()).
2418  */
2419 void
2420 device_set_desc(device_t dev, const char* desc)
2421 {
2422 	device_set_desc_internal(dev, desc, FALSE);
2423 }
2424 
2425 /**
2426  * @brief Set the device's description
2427  *
2428  * The string pointed to by @c desc is copied. Use this function if
2429  * the device description is generated, (e.g. with sprintf()).
2430  */
2431 void
2432 device_set_desc_copy(device_t dev, const char* desc)
2433 {
2434 	device_set_desc_internal(dev, desc, TRUE);
2435 }
2436 
2437 /**
2438  * @brief Set the device's flags
2439  */
2440 void
2441 device_set_flags(device_t dev, uint32_t flags)
2442 {
2443 	dev->devflags = flags;
2444 }
2445 
2446 /**
2447  * @brief Return the device's softc field
2448  *
2449  * The softc is allocated and zeroed when a driver is attached, based
2450  * on the size field of the driver.
2451  */
2452 void *
2453 device_get_softc(device_t dev)
2454 {
2455 	return (dev->softc);
2456 }
2457 
2458 /**
2459  * @brief Set the device's softc field
2460  *
2461  * Most drivers do not need to use this since the softc is allocated
2462  * automatically when the driver is attached.
2463  */
2464 void
2465 device_set_softc(device_t dev, void *softc)
2466 {
2467 	if (dev->softc && !(dev->flags & DF_EXTERNALSOFTC))
2468 		free(dev->softc, M_BUS_SC);
2469 	dev->softc = softc;
2470 	if (dev->softc)
2471 		dev->flags |= DF_EXTERNALSOFTC;
2472 	else
2473 		dev->flags &= ~DF_EXTERNALSOFTC;
2474 }
2475 
2476 /**
2477  * @brief Free claimed softc
2478  *
2479  * Most drivers do not need to use this since the softc is freed
2480  * automatically when the driver is detached.
2481  */
2482 void
2483 device_free_softc(void *softc)
2484 {
2485 	free(softc, M_BUS_SC);
2486 }
2487 
2488 /**
2489  * @brief Claim softc
2490  *
2491  * This function can be used to let the driver free the automatically
2492  * allocated softc using "device_free_softc()". This function is
2493  * useful when the driver is refcounting the softc and the softc
2494  * cannot be freed when the "device_detach" method is called.
2495  */
2496 void
2497 device_claim_softc(device_t dev)
2498 {
2499 	if (dev->softc)
2500 		dev->flags |= DF_EXTERNALSOFTC;
2501 	else
2502 		dev->flags &= ~DF_EXTERNALSOFTC;
2503 }
2504 
2505 /**
2506  * @brief Get the device's ivars field
2507  *
2508  * The ivars field is used by the parent device to store per-device
2509  * state (e.g. the physical location of the device or a list of
2510  * resources).
2511  */
2512 void *
2513 device_get_ivars(device_t dev)
2514 {
2515 
2516 	KASSERT(dev != NULL, ("device_get_ivars(NULL, ...)"));
2517 	return (dev->ivars);
2518 }
2519 
2520 /**
2521  * @brief Set the device's ivars field
2522  */
2523 void
2524 device_set_ivars(device_t dev, void * ivars)
2525 {
2526 
2527 	KASSERT(dev != NULL, ("device_set_ivars(NULL, ...)"));
2528 	dev->ivars = ivars;
2529 }
2530 
2531 /**
2532  * @brief Return the device's state
2533  */
2534 device_state_t
2535 device_get_state(device_t dev)
2536 {
2537 	return (dev->state);
2538 }
2539 
2540 /**
2541  * @brief Set the DF_ENABLED flag for the device
2542  */
2543 void
2544 device_enable(device_t dev)
2545 {
2546 	dev->flags |= DF_ENABLED;
2547 }
2548 
2549 /**
2550  * @brief Clear the DF_ENABLED flag for the device
2551  */
2552 void
2553 device_disable(device_t dev)
2554 {
2555 	dev->flags &= ~DF_ENABLED;
2556 }
2557 
2558 /**
2559  * @brief Increment the busy counter for the device
2560  */
2561 void
2562 device_busy(device_t dev)
2563 {
2564 	if (dev->state < DS_ATTACHING)
2565 		panic("device_busy: called for unattached device");
2566 	if (dev->busy == 0 && dev->parent)
2567 		device_busy(dev->parent);
2568 	dev->busy++;
2569 	if (dev->state == DS_ATTACHED)
2570 		dev->state = DS_BUSY;
2571 }
2572 
2573 /**
2574  * @brief Decrement the busy counter for the device
2575  */
2576 void
2577 device_unbusy(device_t dev)
2578 {
2579 	if (dev->busy != 0 && dev->state != DS_BUSY &&
2580 	    dev->state != DS_ATTACHING)
2581 		panic("device_unbusy: called for non-busy device %s",
2582 		    device_get_nameunit(dev));
2583 	dev->busy--;
2584 	if (dev->busy == 0) {
2585 		if (dev->parent)
2586 			device_unbusy(dev->parent);
2587 		if (dev->state == DS_BUSY)
2588 			dev->state = DS_ATTACHED;
2589 	}
2590 }
2591 
2592 /**
2593  * @brief Set the DF_QUIET flag for the device
2594  */
2595 void
2596 device_quiet(device_t dev)
2597 {
2598 	dev->flags |= DF_QUIET;
2599 }
2600 
2601 /**
2602  * @brief Clear the DF_QUIET flag for the device
2603  */
2604 void
2605 device_verbose(device_t dev)
2606 {
2607 	dev->flags &= ~DF_QUIET;
2608 }
2609 
2610 /**
2611  * @brief Return non-zero if the DF_QUIET flag is set on the device
2612  */
2613 int
2614 device_is_quiet(device_t dev)
2615 {
2616 	return ((dev->flags & DF_QUIET) != 0);
2617 }
2618 
2619 /**
2620  * @brief Return non-zero if the DF_ENABLED flag is set on the device
2621  */
2622 int
2623 device_is_enabled(device_t dev)
2624 {
2625 	return ((dev->flags & DF_ENABLED) != 0);
2626 }
2627 
2628 /**
2629  * @brief Return non-zero if the device was successfully probed
2630  */
2631 int
2632 device_is_alive(device_t dev)
2633 {
2634 	return (dev->state >= DS_ALIVE);
2635 }
2636 
2637 /**
2638  * @brief Return non-zero if the device currently has a driver
2639  * attached to it
2640  */
2641 int
2642 device_is_attached(device_t dev)
2643 {
2644 	return (dev->state >= DS_ATTACHED);
2645 }
2646 
2647 /**
2648  * @brief Return non-zero if the device is currently suspended.
2649  */
2650 int
2651 device_is_suspended(device_t dev)
2652 {
2653 	return ((dev->flags & DF_SUSPENDED) != 0);
2654 }
2655 
2656 /**
2657  * @brief Set the devclass of a device
2658  * @see devclass_add_device().
2659  */
2660 int
2661 device_set_devclass(device_t dev, const char *classname)
2662 {
2663 	devclass_t dc;
2664 	int error;
2665 
2666 	if (!classname) {
2667 		if (dev->devclass)
2668 			devclass_delete_device(dev->devclass, dev);
2669 		return (0);
2670 	}
2671 
2672 	if (dev->devclass) {
2673 		printf("device_set_devclass: device class already set\n");
2674 		return (EINVAL);
2675 	}
2676 
2677 	dc = devclass_find_internal(classname, NULL, TRUE);
2678 	if (!dc)
2679 		return (ENOMEM);
2680 
2681 	error = devclass_add_device(dc, dev);
2682 
2683 	bus_data_generation_update();
2684 	return (error);
2685 }
2686 
2687 /**
2688  * @brief Set the devclass of a device and mark the devclass fixed.
2689  * @see device_set_devclass()
2690  */
2691 int
2692 device_set_devclass_fixed(device_t dev, const char *classname)
2693 {
2694 	int error;
2695 
2696 	if (classname == NULL)
2697 		return (EINVAL);
2698 
2699 	error = device_set_devclass(dev, classname);
2700 	if (error)
2701 		return (error);
2702 	dev->flags |= DF_FIXEDCLASS;
2703 	return (0);
2704 }
2705 
2706 /**
2707  * @brief Set the driver of a device
2708  *
2709  * @retval 0		success
2710  * @retval EBUSY	the device already has a driver attached
2711  * @retval ENOMEM	a memory allocation failure occurred
2712  */
2713 int
2714 device_set_driver(device_t dev, driver_t *driver)
2715 {
2716 	if (dev->state >= DS_ATTACHED)
2717 		return (EBUSY);
2718 
2719 	if (dev->driver == driver)
2720 		return (0);
2721 
2722 	if (dev->softc && !(dev->flags & DF_EXTERNALSOFTC)) {
2723 		free(dev->softc, M_BUS_SC);
2724 		dev->softc = NULL;
2725 	}
2726 	device_set_desc(dev, NULL);
2727 	kobj_delete((kobj_t) dev, NULL);
2728 	dev->driver = driver;
2729 	if (driver) {
2730 		kobj_init((kobj_t) dev, (kobj_class_t) driver);
2731 		if (!(dev->flags & DF_EXTERNALSOFTC) && driver->size > 0) {
2732 			dev->softc = malloc(driver->size, M_BUS_SC,
2733 			    M_NOWAIT | M_ZERO);
2734 			if (!dev->softc) {
2735 				kobj_delete((kobj_t) dev, NULL);
2736 				kobj_init((kobj_t) dev, &null_class);
2737 				dev->driver = NULL;
2738 				return (ENOMEM);
2739 			}
2740 		}
2741 	} else {
2742 		kobj_init((kobj_t) dev, &null_class);
2743 	}
2744 
2745 	bus_data_generation_update();
2746 	return (0);
2747 }
2748 
2749 /**
2750  * @brief Probe a device, and return this status.
2751  *
2752  * This function is the core of the device autoconfiguration
2753  * system. Its purpose is to select a suitable driver for a device and
2754  * then call that driver to initialise the hardware appropriately. The
2755  * driver is selected by calling the DEVICE_PROBE() method of a set of
2756  * candidate drivers and then choosing the driver which returned the
2757  * best value. This driver is then attached to the device using
2758  * device_attach().
2759  *
2760  * The set of suitable drivers is taken from the list of drivers in
2761  * the parent device's devclass. If the device was originally created
2762  * with a specific class name (see device_add_child()), only drivers
2763  * with that name are probed, otherwise all drivers in the devclass
2764  * are probed. If no drivers return successful probe values in the
2765  * parent devclass, the search continues in the parent of that
2766  * devclass (see devclass_get_parent()) if any.
2767  *
2768  * @param dev		the device to initialise
2769  *
2770  * @retval 0		success
2771  * @retval ENXIO	no driver was found
2772  * @retval ENOMEM	memory allocation failure
2773  * @retval non-zero	some other unix error code
2774  * @retval -1		Device already attached
2775  */
2776 int
2777 device_probe(device_t dev)
2778 {
2779 	int error;
2780 
2781 	GIANT_REQUIRED;
2782 
2783 	if (dev->state >= DS_ALIVE && (dev->flags & DF_REBID) == 0)
2784 		return (-1);
2785 
2786 	if (!(dev->flags & DF_ENABLED)) {
2787 		if (bootverbose && device_get_name(dev) != NULL) {
2788 			device_print_prettyname(dev);
2789 			printf("not probed (disabled)\n");
2790 		}
2791 		return (-1);
2792 	}
2793 	if ((error = device_probe_child(dev->parent, dev)) != 0) {
2794 		if (bus_current_pass == BUS_PASS_DEFAULT &&
2795 		    !(dev->flags & DF_DONENOMATCH)) {
2796 			BUS_PROBE_NOMATCH(dev->parent, dev);
2797 			devnomatch(dev);
2798 			dev->flags |= DF_DONENOMATCH;
2799 		}
2800 		return (error);
2801 	}
2802 	return (0);
2803 }
2804 
2805 /**
2806  * @brief Probe a device and attach a driver if possible
2807  *
2808  * calls device_probe() and attaches if that was successful.
2809  */
2810 int
2811 device_probe_and_attach(device_t dev)
2812 {
2813 	int error;
2814 
2815 	GIANT_REQUIRED;
2816 
2817 	error = device_probe(dev);
2818 	if (error == -1)
2819 		return (0);
2820 	else if (error != 0)
2821 		return (error);
2822 
2823 	CURVNET_SET_QUIET(vnet0);
2824 	error = device_attach(dev);
2825 	CURVNET_RESTORE();
2826 	return error;
2827 }
2828 
2829 /**
2830  * @brief Attach a device driver to a device
2831  *
2832  * This function is a wrapper around the DEVICE_ATTACH() driver
2833  * method. In addition to calling DEVICE_ATTACH(), it initialises the
2834  * device's sysctl tree, optionally prints a description of the device
2835  * and queues a notification event for user-based device management
2836  * services.
2837  *
2838  * Normally this function is only called internally from
2839  * device_probe_and_attach().
2840  *
2841  * @param dev		the device to initialise
2842  *
2843  * @retval 0		success
2844  * @retval ENXIO	no driver was found
2845  * @retval ENOMEM	memory allocation failure
2846  * @retval non-zero	some other unix error code
2847  */
2848 int
2849 device_attach(device_t dev)
2850 {
2851 	uint64_t attachtime;
2852 	int error;
2853 
2854 	if (resource_disabled(dev->driver->name, dev->unit)) {
2855 		device_disable(dev);
2856 		if (bootverbose)
2857 			 device_printf(dev, "disabled via hints entry\n");
2858 		return (ENXIO);
2859 	}
2860 
2861 	device_sysctl_init(dev);
2862 	if (!device_is_quiet(dev))
2863 		device_print_child(dev->parent, dev);
2864 	attachtime = get_cyclecount();
2865 	dev->state = DS_ATTACHING;
2866 	if ((error = DEVICE_ATTACH(dev)) != 0) {
2867 		printf("device_attach: %s%d attach returned %d\n",
2868 		    dev->driver->name, dev->unit, error);
2869 		if (!(dev->flags & DF_FIXEDCLASS))
2870 			devclass_delete_device(dev->devclass, dev);
2871 		(void)device_set_driver(dev, NULL);
2872 		device_sysctl_fini(dev);
2873 		KASSERT(dev->busy == 0, ("attach failed but busy"));
2874 		dev->state = DS_NOTPRESENT;
2875 		return (error);
2876 	}
2877 	attachtime = get_cyclecount() - attachtime;
2878 	/*
2879 	 * 4 bits per device is a reasonable value for desktop and server
2880 	 * hardware with good get_cyclecount() implementations, but may
2881 	 * need to be adjusted on other platforms.
2882 	 */
2883 #ifdef RANDOM_DEBUG
2884 	printf("random: %s(): feeding %d bit(s) of entropy from %s%d\n",
2885 	    __func__, 4, dev->driver->name, dev->unit);
2886 #endif
2887 	random_harvest(&attachtime, sizeof(attachtime), 4, RANDOM_ATTACH);
2888 	device_sysctl_update(dev);
2889 	if (dev->busy)
2890 		dev->state = DS_BUSY;
2891 	else
2892 		dev->state = DS_ATTACHED;
2893 	dev->flags &= ~DF_DONENOMATCH;
2894 	devadded(dev);
2895 	return (0);
2896 }
2897 
2898 /**
2899  * @brief Detach a driver from a device
2900  *
2901  * This function is a wrapper around the DEVICE_DETACH() driver
2902  * method. If the call to DEVICE_DETACH() succeeds, it calls
2903  * BUS_CHILD_DETACHED() for the parent of @p dev, queues a
2904  * notification event for user-based device management services and
2905  * cleans up the device's sysctl tree.
2906  *
2907  * @param dev		the device to un-initialise
2908  *
2909  * @retval 0		success
2910  * @retval ENXIO	no driver was found
2911  * @retval ENOMEM	memory allocation failure
2912  * @retval non-zero	some other unix error code
2913  */
2914 int
2915 device_detach(device_t dev)
2916 {
2917 	int error;
2918 
2919 	GIANT_REQUIRED;
2920 
2921 	PDEBUG(("%s", DEVICENAME(dev)));
2922 	if (dev->state == DS_BUSY)
2923 		return (EBUSY);
2924 	if (dev->state != DS_ATTACHED)
2925 		return (0);
2926 
2927 	if ((error = DEVICE_DETACH(dev)) != 0)
2928 		return (error);
2929 	devremoved(dev);
2930 	if (!device_is_quiet(dev))
2931 		device_printf(dev, "detached\n");
2932 	if (dev->parent)
2933 		BUS_CHILD_DETACHED(dev->parent, dev);
2934 
2935 	if (!(dev->flags & DF_FIXEDCLASS))
2936 		devclass_delete_device(dev->devclass, dev);
2937 
2938 	dev->state = DS_NOTPRESENT;
2939 	(void)device_set_driver(dev, NULL);
2940 	device_sysctl_fini(dev);
2941 
2942 	return (0);
2943 }
2944 
2945 /**
2946  * @brief Tells a driver to quiesce itself.
2947  *
2948  * This function is a wrapper around the DEVICE_QUIESCE() driver
2949  * method. If the call to DEVICE_QUIESCE() succeeds.
2950  *
2951  * @param dev		the device to quiesce
2952  *
2953  * @retval 0		success
2954  * @retval ENXIO	no driver was found
2955  * @retval ENOMEM	memory allocation failure
2956  * @retval non-zero	some other unix error code
2957  */
2958 int
2959 device_quiesce(device_t dev)
2960 {
2961 
2962 	PDEBUG(("%s", DEVICENAME(dev)));
2963 	if (dev->state == DS_BUSY)
2964 		return (EBUSY);
2965 	if (dev->state != DS_ATTACHED)
2966 		return (0);
2967 
2968 	return (DEVICE_QUIESCE(dev));
2969 }
2970 
2971 /**
2972  * @brief Notify a device of system shutdown
2973  *
2974  * This function calls the DEVICE_SHUTDOWN() driver method if the
2975  * device currently has an attached driver.
2976  *
2977  * @returns the value returned by DEVICE_SHUTDOWN()
2978  */
2979 int
2980 device_shutdown(device_t dev)
2981 {
2982 	if (dev->state < DS_ATTACHED)
2983 		return (0);
2984 	return (DEVICE_SHUTDOWN(dev));
2985 }
2986 
2987 /**
2988  * @brief Set the unit number of a device
2989  *
2990  * This function can be used to override the unit number used for a
2991  * device (e.g. to wire a device to a pre-configured unit number).
2992  */
2993 int
2994 device_set_unit(device_t dev, int unit)
2995 {
2996 	devclass_t dc;
2997 	int err;
2998 
2999 	dc = device_get_devclass(dev);
3000 	if (unit < dc->maxunit && dc->devices[unit])
3001 		return (EBUSY);
3002 	err = devclass_delete_device(dc, dev);
3003 	if (err)
3004 		return (err);
3005 	dev->unit = unit;
3006 	err = devclass_add_device(dc, dev);
3007 	if (err)
3008 		return (err);
3009 
3010 	bus_data_generation_update();
3011 	return (0);
3012 }
3013 
3014 /*======================================*/
3015 /*
3016  * Some useful method implementations to make life easier for bus drivers.
3017  */
3018 
3019 /**
3020  * @brief Initialise a resource list.
3021  *
3022  * @param rl		the resource list to initialise
3023  */
3024 void
3025 resource_list_init(struct resource_list *rl)
3026 {
3027 	STAILQ_INIT(rl);
3028 }
3029 
3030 /**
3031  * @brief Reclaim memory used by a resource list.
3032  *
3033  * This function frees the memory for all resource entries on the list
3034  * (if any).
3035  *
3036  * @param rl		the resource list to free
3037  */
3038 void
3039 resource_list_free(struct resource_list *rl)
3040 {
3041 	struct resource_list_entry *rle;
3042 
3043 	while ((rle = STAILQ_FIRST(rl)) != NULL) {
3044 		if (rle->res)
3045 			panic("resource_list_free: resource entry is busy");
3046 		STAILQ_REMOVE_HEAD(rl, link);
3047 		free(rle, M_BUS);
3048 	}
3049 }
3050 
3051 /**
3052  * @brief Add a resource entry.
3053  *
3054  * This function adds a resource entry using the given @p type, @p
3055  * start, @p end and @p count values. A rid value is chosen by
3056  * searching sequentially for the first unused rid starting at zero.
3057  *
3058  * @param rl		the resource list to edit
3059  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
3060  * @param start		the start address of the resource
3061  * @param end		the end address of the resource
3062  * @param count		XXX end-start+1
3063  */
3064 int
3065 resource_list_add_next(struct resource_list *rl, int type, u_long start,
3066     u_long end, u_long count)
3067 {
3068 	int rid;
3069 
3070 	rid = 0;
3071 	while (resource_list_find(rl, type, rid) != NULL)
3072 		rid++;
3073 	resource_list_add(rl, type, rid, start, end, count);
3074 	return (rid);
3075 }
3076 
3077 /**
3078  * @brief Add or modify a resource entry.
3079  *
3080  * If an existing entry exists with the same type and rid, it will be
3081  * modified using the given values of @p start, @p end and @p
3082  * count. If no entry exists, a new one will be created using the
3083  * given values.  The resource list entry that matches is then returned.
3084  *
3085  * @param rl		the resource list to edit
3086  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
3087  * @param rid		the resource identifier
3088  * @param start		the start address of the resource
3089  * @param end		the end address of the resource
3090  * @param count		XXX end-start+1
3091  */
3092 struct resource_list_entry *
3093 resource_list_add(struct resource_list *rl, int type, int rid,
3094     u_long start, u_long end, u_long count)
3095 {
3096 	struct resource_list_entry *rle;
3097 
3098 	rle = resource_list_find(rl, type, rid);
3099 	if (!rle) {
3100 		rle = malloc(sizeof(struct resource_list_entry), M_BUS,
3101 		    M_NOWAIT);
3102 		if (!rle)
3103 			panic("resource_list_add: can't record entry");
3104 		STAILQ_INSERT_TAIL(rl, rle, link);
3105 		rle->type = type;
3106 		rle->rid = rid;
3107 		rle->res = NULL;
3108 		rle->flags = 0;
3109 	}
3110 
3111 	if (rle->res)
3112 		panic("resource_list_add: resource entry is busy");
3113 
3114 	rle->start = start;
3115 	rle->end = end;
3116 	rle->count = count;
3117 	return (rle);
3118 }
3119 
3120 /**
3121  * @brief Determine if a resource entry is busy.
3122  *
3123  * Returns true if a resource entry is busy meaning that it has an
3124  * associated resource that is not an unallocated "reserved" resource.
3125  *
3126  * @param rl		the resource list to search
3127  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
3128  * @param rid		the resource identifier
3129  *
3130  * @returns Non-zero if the entry is busy, zero otherwise.
3131  */
3132 int
3133 resource_list_busy(struct resource_list *rl, int type, int rid)
3134 {
3135 	struct resource_list_entry *rle;
3136 
3137 	rle = resource_list_find(rl, type, rid);
3138 	if (rle == NULL || rle->res == NULL)
3139 		return (0);
3140 	if ((rle->flags & (RLE_RESERVED | RLE_ALLOCATED)) == RLE_RESERVED) {
3141 		KASSERT(!(rman_get_flags(rle->res) & RF_ACTIVE),
3142 		    ("reserved resource is active"));
3143 		return (0);
3144 	}
3145 	return (1);
3146 }
3147 
3148 /**
3149  * @brief Determine if a resource entry is reserved.
3150  *
3151  * Returns true if a resource entry is reserved meaning that it has an
3152  * associated "reserved" resource.  The resource can either be
3153  * allocated or unallocated.
3154  *
3155  * @param rl		the resource list to search
3156  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
3157  * @param rid		the resource identifier
3158  *
3159  * @returns Non-zero if the entry is reserved, zero otherwise.
3160  */
3161 int
3162 resource_list_reserved(struct resource_list *rl, int type, int rid)
3163 {
3164 	struct resource_list_entry *rle;
3165 
3166 	rle = resource_list_find(rl, type, rid);
3167 	if (rle != NULL && rle->flags & RLE_RESERVED)
3168 		return (1);
3169 	return (0);
3170 }
3171 
3172 /**
3173  * @brief Find a resource entry by type and rid.
3174  *
3175  * @param rl		the resource list to search
3176  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
3177  * @param rid		the resource identifier
3178  *
3179  * @returns the resource entry pointer or NULL if there is no such
3180  * entry.
3181  */
3182 struct resource_list_entry *
3183 resource_list_find(struct resource_list *rl, int type, int rid)
3184 {
3185 	struct resource_list_entry *rle;
3186 
3187 	STAILQ_FOREACH(rle, rl, link) {
3188 		if (rle->type == type && rle->rid == rid)
3189 			return (rle);
3190 	}
3191 	return (NULL);
3192 }
3193 
3194 /**
3195  * @brief Delete a resource entry.
3196  *
3197  * @param rl		the resource list to edit
3198  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
3199  * @param rid		the resource identifier
3200  */
3201 void
3202 resource_list_delete(struct resource_list *rl, int type, int rid)
3203 {
3204 	struct resource_list_entry *rle = resource_list_find(rl, type, rid);
3205 
3206 	if (rle) {
3207 		if (rle->res != NULL)
3208 			panic("resource_list_delete: resource has not been released");
3209 		STAILQ_REMOVE(rl, rle, resource_list_entry, link);
3210 		free(rle, M_BUS);
3211 	}
3212 }
3213 
3214 /**
3215  * @brief Allocate a reserved resource
3216  *
3217  * This can be used by busses to force the allocation of resources
3218  * that are always active in the system even if they are not allocated
3219  * by a driver (e.g. PCI BARs).  This function is usually called when
3220  * adding a new child to the bus.  The resource is allocated from the
3221  * parent bus when it is reserved.  The resource list entry is marked
3222  * with RLE_RESERVED to note that it is a reserved resource.
3223  *
3224  * Subsequent attempts to allocate the resource with
3225  * resource_list_alloc() will succeed the first time and will set
3226  * RLE_ALLOCATED to note that it has been allocated.  When a reserved
3227  * resource that has been allocated is released with
3228  * resource_list_release() the resource RLE_ALLOCATED is cleared, but
3229  * the actual resource remains allocated.  The resource can be released to
3230  * the parent bus by calling resource_list_unreserve().
3231  *
3232  * @param rl		the resource list to allocate from
3233  * @param bus		the parent device of @p child
3234  * @param child		the device for which the resource is being reserved
3235  * @param type		the type of resource to allocate
3236  * @param rid		a pointer to the resource identifier
3237  * @param start		hint at the start of the resource range - pass
3238  *			@c 0UL for any start address
3239  * @param end		hint at the end of the resource range - pass
3240  *			@c ~0UL for any end address
3241  * @param count		hint at the size of range required - pass @c 1
3242  *			for any size
3243  * @param flags		any extra flags to control the resource
3244  *			allocation - see @c RF_XXX flags in
3245  *			<sys/rman.h> for details
3246  *
3247  * @returns		the resource which was allocated or @c NULL if no
3248  *			resource could be allocated
3249  */
3250 struct resource *
3251 resource_list_reserve(struct resource_list *rl, device_t bus, device_t child,
3252     int type, int *rid, u_long start, u_long end, u_long count, u_int flags)
3253 {
3254 	struct resource_list_entry *rle = NULL;
3255 	int passthrough = (device_get_parent(child) != bus);
3256 	struct resource *r;
3257 
3258 	if (passthrough)
3259 		panic(
3260     "resource_list_reserve() should only be called for direct children");
3261 	if (flags & RF_ACTIVE)
3262 		panic(
3263     "resource_list_reserve() should only reserve inactive resources");
3264 
3265 	r = resource_list_alloc(rl, bus, child, type, rid, start, end, count,
3266 	    flags);
3267 	if (r != NULL) {
3268 		rle = resource_list_find(rl, type, *rid);
3269 		rle->flags |= RLE_RESERVED;
3270 	}
3271 	return (r);
3272 }
3273 
3274 /**
3275  * @brief Helper function for implementing BUS_ALLOC_RESOURCE()
3276  *
3277  * Implement BUS_ALLOC_RESOURCE() by looking up a resource from the list
3278  * and passing the allocation up to the parent of @p bus. This assumes
3279  * that the first entry of @c device_get_ivars(child) is a struct
3280  * resource_list. This also handles 'passthrough' allocations where a
3281  * child is a remote descendant of bus by passing the allocation up to
3282  * the parent of bus.
3283  *
3284  * Typically, a bus driver would store a list of child resources
3285  * somewhere in the child device's ivars (see device_get_ivars()) and
3286  * its implementation of BUS_ALLOC_RESOURCE() would find that list and
3287  * then call resource_list_alloc() to perform the allocation.
3288  *
3289  * @param rl		the resource list to allocate from
3290  * @param bus		the parent device of @p child
3291  * @param child		the device which is requesting an allocation
3292  * @param type		the type of resource to allocate
3293  * @param rid		a pointer to the resource identifier
3294  * @param start		hint at the start of the resource range - pass
3295  *			@c 0UL for any start address
3296  * @param end		hint at the end of the resource range - pass
3297  *			@c ~0UL for any end address
3298  * @param count		hint at the size of range required - pass @c 1
3299  *			for any size
3300  * @param flags		any extra flags to control the resource
3301  *			allocation - see @c RF_XXX flags in
3302  *			<sys/rman.h> for details
3303  *
3304  * @returns		the resource which was allocated or @c NULL if no
3305  *			resource could be allocated
3306  */
3307 struct resource *
3308 resource_list_alloc(struct resource_list *rl, device_t bus, device_t child,
3309     int type, int *rid, u_long start, u_long end, u_long count, u_int flags)
3310 {
3311 	struct resource_list_entry *rle = NULL;
3312 	int passthrough = (device_get_parent(child) != bus);
3313 	int isdefault = (start == 0UL && end == ~0UL);
3314 
3315 	if (passthrough) {
3316 		return (BUS_ALLOC_RESOURCE(device_get_parent(bus), child,
3317 		    type, rid, start, end, count, flags));
3318 	}
3319 
3320 	rle = resource_list_find(rl, type, *rid);
3321 
3322 	if (!rle)
3323 		return (NULL);		/* no resource of that type/rid */
3324 
3325 	if (rle->res) {
3326 		if (rle->flags & RLE_RESERVED) {
3327 			if (rle->flags & RLE_ALLOCATED)
3328 				return (NULL);
3329 			if ((flags & RF_ACTIVE) &&
3330 			    bus_activate_resource(child, type, *rid,
3331 			    rle->res) != 0)
3332 				return (NULL);
3333 			rle->flags |= RLE_ALLOCATED;
3334 			return (rle->res);
3335 		}
3336 		device_printf(bus,
3337 		    "resource entry %#x type %d for child %s is busy\n", *rid,
3338 		    type, device_get_nameunit(child));
3339 		return (NULL);
3340 	}
3341 
3342 	if (isdefault) {
3343 		start = rle->start;
3344 		count = ulmax(count, rle->count);
3345 		end = ulmax(rle->end, start + count - 1);
3346 	}
3347 
3348 	rle->res = BUS_ALLOC_RESOURCE(device_get_parent(bus), child,
3349 	    type, rid, start, end, count, flags);
3350 
3351 	/*
3352 	 * Record the new range.
3353 	 */
3354 	if (rle->res) {
3355 		rle->start = rman_get_start(rle->res);
3356 		rle->end = rman_get_end(rle->res);
3357 		rle->count = count;
3358 	}
3359 
3360 	return (rle->res);
3361 }
3362 
3363 /**
3364  * @brief Helper function for implementing BUS_RELEASE_RESOURCE()
3365  *
3366  * Implement BUS_RELEASE_RESOURCE() using a resource list. Normally
3367  * used with resource_list_alloc().
3368  *
3369  * @param rl		the resource list which was allocated from
3370  * @param bus		the parent device of @p child
3371  * @param child		the device which is requesting a release
3372  * @param type		the type of resource to release
3373  * @param rid		the resource identifier
3374  * @param res		the resource to release
3375  *
3376  * @retval 0		success
3377  * @retval non-zero	a standard unix error code indicating what
3378  *			error condition prevented the operation
3379  */
3380 int
3381 resource_list_release(struct resource_list *rl, device_t bus, device_t child,
3382     int type, int rid, struct resource *res)
3383 {
3384 	struct resource_list_entry *rle = NULL;
3385 	int passthrough = (device_get_parent(child) != bus);
3386 	int error;
3387 
3388 	if (passthrough) {
3389 		return (BUS_RELEASE_RESOURCE(device_get_parent(bus), child,
3390 		    type, rid, res));
3391 	}
3392 
3393 	rle = resource_list_find(rl, type, rid);
3394 
3395 	if (!rle)
3396 		panic("resource_list_release: can't find resource");
3397 	if (!rle->res)
3398 		panic("resource_list_release: resource entry is not busy");
3399 	if (rle->flags & RLE_RESERVED) {
3400 		if (rle->flags & RLE_ALLOCATED) {
3401 			if (rman_get_flags(res) & RF_ACTIVE) {
3402 				error = bus_deactivate_resource(child, type,
3403 				    rid, res);
3404 				if (error)
3405 					return (error);
3406 			}
3407 			rle->flags &= ~RLE_ALLOCATED;
3408 			return (0);
3409 		}
3410 		return (EINVAL);
3411 	}
3412 
3413 	error = BUS_RELEASE_RESOURCE(device_get_parent(bus), child,
3414 	    type, rid, res);
3415 	if (error)
3416 		return (error);
3417 
3418 	rle->res = NULL;
3419 	return (0);
3420 }
3421 
3422 /**
3423  * @brief Release all active resources of a given type
3424  *
3425  * Release all active resources of a specified type.  This is intended
3426  * to be used to cleanup resources leaked by a driver after detach or
3427  * a failed attach.
3428  *
3429  * @param rl		the resource list which was allocated from
3430  * @param bus		the parent device of @p child
3431  * @param child		the device whose active resources are being released
3432  * @param type		the type of resources to release
3433  *
3434  * @retval 0		success
3435  * @retval EBUSY	at least one resource was active
3436  */
3437 int
3438 resource_list_release_active(struct resource_list *rl, device_t bus,
3439     device_t child, int type)
3440 {
3441 	struct resource_list_entry *rle;
3442 	int error, retval;
3443 
3444 	retval = 0;
3445 	STAILQ_FOREACH(rle, rl, link) {
3446 		if (rle->type != type)
3447 			continue;
3448 		if (rle->res == NULL)
3449 			continue;
3450 		if ((rle->flags & (RLE_RESERVED | RLE_ALLOCATED)) ==
3451 		    RLE_RESERVED)
3452 			continue;
3453 		retval = EBUSY;
3454 		error = resource_list_release(rl, bus, child, type,
3455 		    rman_get_rid(rle->res), rle->res);
3456 		if (error != 0)
3457 			device_printf(bus,
3458 			    "Failed to release active resource: %d\n", error);
3459 	}
3460 	return (retval);
3461 }
3462 
3463 
3464 /**
3465  * @brief Fully release a reserved resource
3466  *
3467  * Fully releases a resource reserved via resource_list_reserve().
3468  *
3469  * @param rl		the resource list which was allocated from
3470  * @param bus		the parent device of @p child
3471  * @param child		the device whose reserved resource is being released
3472  * @param type		the type of resource to release
3473  * @param rid		the resource identifier
3474  * @param res		the resource to release
3475  *
3476  * @retval 0		success
3477  * @retval non-zero	a standard unix error code indicating what
3478  *			error condition prevented the operation
3479  */
3480 int
3481 resource_list_unreserve(struct resource_list *rl, device_t bus, device_t child,
3482     int type, int rid)
3483 {
3484 	struct resource_list_entry *rle = NULL;
3485 	int passthrough = (device_get_parent(child) != bus);
3486 
3487 	if (passthrough)
3488 		panic(
3489     "resource_list_unreserve() should only be called for direct children");
3490 
3491 	rle = resource_list_find(rl, type, rid);
3492 
3493 	if (!rle)
3494 		panic("resource_list_unreserve: can't find resource");
3495 	if (!(rle->flags & RLE_RESERVED))
3496 		return (EINVAL);
3497 	if (rle->flags & RLE_ALLOCATED)
3498 		return (EBUSY);
3499 	rle->flags &= ~RLE_RESERVED;
3500 	return (resource_list_release(rl, bus, child, type, rid, rle->res));
3501 }
3502 
3503 /**
3504  * @brief Print a description of resources in a resource list
3505  *
3506  * Print all resources of a specified type, for use in BUS_PRINT_CHILD().
3507  * The name is printed if at least one resource of the given type is available.
3508  * The format is used to print resource start and end.
3509  *
3510  * @param rl		the resource list to print
3511  * @param name		the name of @p type, e.g. @c "memory"
3512  * @param type		type type of resource entry to print
3513  * @param format	printf(9) format string to print resource
3514  *			start and end values
3515  *
3516  * @returns		the number of characters printed
3517  */
3518 int
3519 resource_list_print_type(struct resource_list *rl, const char *name, int type,
3520     const char *format)
3521 {
3522 	struct resource_list_entry *rle;
3523 	int printed, retval;
3524 
3525 	printed = 0;
3526 	retval = 0;
3527 	/* Yes, this is kinda cheating */
3528 	STAILQ_FOREACH(rle, rl, link) {
3529 		if (rle->type == type) {
3530 			if (printed == 0)
3531 				retval += printf(" %s ", name);
3532 			else
3533 				retval += printf(",");
3534 			printed++;
3535 			retval += printf(format, rle->start);
3536 			if (rle->count > 1) {
3537 				retval += printf("-");
3538 				retval += printf(format, rle->start +
3539 						 rle->count - 1);
3540 			}
3541 		}
3542 	}
3543 	return (retval);
3544 }
3545 
3546 /**
3547  * @brief Releases all the resources in a list.
3548  *
3549  * @param rl		The resource list to purge.
3550  *
3551  * @returns		nothing
3552  */
3553 void
3554 resource_list_purge(struct resource_list *rl)
3555 {
3556 	struct resource_list_entry *rle;
3557 
3558 	while ((rle = STAILQ_FIRST(rl)) != NULL) {
3559 		if (rle->res)
3560 			bus_release_resource(rman_get_device(rle->res),
3561 			    rle->type, rle->rid, rle->res);
3562 		STAILQ_REMOVE_HEAD(rl, link);
3563 		free(rle, M_BUS);
3564 	}
3565 }
3566 
3567 device_t
3568 bus_generic_add_child(device_t dev, u_int order, const char *name, int unit)
3569 {
3570 
3571 	return (device_add_child_ordered(dev, order, name, unit));
3572 }
3573 
3574 /**
3575  * @brief Helper function for implementing DEVICE_PROBE()
3576  *
3577  * This function can be used to help implement the DEVICE_PROBE() for
3578  * a bus (i.e. a device which has other devices attached to it). It
3579  * calls the DEVICE_IDENTIFY() method of each driver in the device's
3580  * devclass.
3581  */
3582 int
3583 bus_generic_probe(device_t dev)
3584 {
3585 	devclass_t dc = dev->devclass;
3586 	driverlink_t dl;
3587 
3588 	TAILQ_FOREACH(dl, &dc->drivers, link) {
3589 		/*
3590 		 * If this driver's pass is too high, then ignore it.
3591 		 * For most drivers in the default pass, this will
3592 		 * never be true.  For early-pass drivers they will
3593 		 * only call the identify routines of eligible drivers
3594 		 * when this routine is called.  Drivers for later
3595 		 * passes should have their identify routines called
3596 		 * on early-pass busses during BUS_NEW_PASS().
3597 		 */
3598 		if (dl->pass > bus_current_pass)
3599 			continue;
3600 		DEVICE_IDENTIFY(dl->driver, dev);
3601 	}
3602 
3603 	return (0);
3604 }
3605 
3606 /**
3607  * @brief Helper function for implementing DEVICE_ATTACH()
3608  *
3609  * This function can be used to help implement the DEVICE_ATTACH() for
3610  * a bus. It calls device_probe_and_attach() for each of the device's
3611  * children.
3612  */
3613 int
3614 bus_generic_attach(device_t dev)
3615 {
3616 	device_t child;
3617 
3618 	TAILQ_FOREACH(child, &dev->children, link) {
3619 		device_probe_and_attach(child);
3620 	}
3621 
3622 	return (0);
3623 }
3624 
3625 /**
3626  * @brief Helper function for implementing DEVICE_DETACH()
3627  *
3628  * This function can be used to help implement the DEVICE_DETACH() for
3629  * a bus. It calls device_detach() for each of the device's
3630  * children.
3631  */
3632 int
3633 bus_generic_detach(device_t dev)
3634 {
3635 	device_t child;
3636 	int error;
3637 
3638 	if (dev->state != DS_ATTACHED)
3639 		return (EBUSY);
3640 
3641 	TAILQ_FOREACH(child, &dev->children, link) {
3642 		if ((error = device_detach(child)) != 0)
3643 			return (error);
3644 	}
3645 
3646 	return (0);
3647 }
3648 
3649 /**
3650  * @brief Helper function for implementing DEVICE_SHUTDOWN()
3651  *
3652  * This function can be used to help implement the DEVICE_SHUTDOWN()
3653  * for a bus. It calls device_shutdown() for each of the device's
3654  * children.
3655  */
3656 int
3657 bus_generic_shutdown(device_t dev)
3658 {
3659 	device_t child;
3660 
3661 	TAILQ_FOREACH(child, &dev->children, link) {
3662 		device_shutdown(child);
3663 	}
3664 
3665 	return (0);
3666 }
3667 
3668 /**
3669  * @brief Default function for suspending a child device.
3670  *
3671  * This function is to be used by a bus's DEVICE_SUSPEND_CHILD().
3672  */
3673 int
3674 bus_generic_suspend_child(device_t dev, device_t child)
3675 {
3676 	int	error;
3677 
3678 	error = DEVICE_SUSPEND(child);
3679 
3680 	if (error == 0)
3681 		child->flags |= DF_SUSPENDED;
3682 
3683 	return (error);
3684 }
3685 
3686 /**
3687  * @brief Default function for resuming a child device.
3688  *
3689  * This function is to be used by a bus's DEVICE_RESUME_CHILD().
3690  */
3691 int
3692 bus_generic_resume_child(device_t dev, device_t child)
3693 {
3694 
3695 	DEVICE_RESUME(child);
3696 	child->flags &= ~DF_SUSPENDED;
3697 
3698 	return (0);
3699 }
3700 
3701 /**
3702  * @brief Helper function for implementing DEVICE_SUSPEND()
3703  *
3704  * This function can be used to help implement the DEVICE_SUSPEND()
3705  * for a bus. It calls DEVICE_SUSPEND() for each of the device's
3706  * children. If any call to DEVICE_SUSPEND() fails, the suspend
3707  * operation is aborted and any devices which were suspended are
3708  * resumed immediately by calling their DEVICE_RESUME() methods.
3709  */
3710 int
3711 bus_generic_suspend(device_t dev)
3712 {
3713 	int		error;
3714 	device_t	child, child2;
3715 
3716 	TAILQ_FOREACH(child, &dev->children, link) {
3717 		error = BUS_SUSPEND_CHILD(dev, child);
3718 		if (error) {
3719 			for (child2 = TAILQ_FIRST(&dev->children);
3720 			     child2 && child2 != child;
3721 			     child2 = TAILQ_NEXT(child2, link))
3722 				BUS_RESUME_CHILD(dev, child2);
3723 			return (error);
3724 		}
3725 	}
3726 	return (0);
3727 }
3728 
3729 /**
3730  * @brief Helper function for implementing DEVICE_RESUME()
3731  *
3732  * This function can be used to help implement the DEVICE_RESUME() for
3733  * a bus. It calls DEVICE_RESUME() on each of the device's children.
3734  */
3735 int
3736 bus_generic_resume(device_t dev)
3737 {
3738 	device_t	child;
3739 
3740 	TAILQ_FOREACH(child, &dev->children, link) {
3741 		BUS_RESUME_CHILD(dev, child);
3742 		/* if resume fails, there's nothing we can usefully do... */
3743 	}
3744 	return (0);
3745 }
3746 
3747 /**
3748  * @brief Helper function for implementing BUS_PRINT_CHILD().
3749  *
3750  * This function prints the first part of the ascii representation of
3751  * @p child, including its name, unit and description (if any - see
3752  * device_set_desc()).
3753  *
3754  * @returns the number of characters printed
3755  */
3756 int
3757 bus_print_child_header(device_t dev, device_t child)
3758 {
3759 	int	retval = 0;
3760 
3761 	if (device_get_desc(child)) {
3762 		retval += device_printf(child, "<%s>", device_get_desc(child));
3763 	} else {
3764 		retval += printf("%s", device_get_nameunit(child));
3765 	}
3766 
3767 	return (retval);
3768 }
3769 
3770 /**
3771  * @brief Helper function for implementing BUS_PRINT_CHILD().
3772  *
3773  * This function prints the last part of the ascii representation of
3774  * @p child, which consists of the string @c " on " followed by the
3775  * name and unit of the @p dev.
3776  *
3777  * @returns the number of characters printed
3778  */
3779 int
3780 bus_print_child_footer(device_t dev, device_t child)
3781 {
3782 	return (printf(" on %s\n", device_get_nameunit(dev)));
3783 }
3784 
3785 /**
3786  * @brief Helper function for implementing BUS_PRINT_CHILD().
3787  *
3788  * This function prints out the VM domain for the given device.
3789  *
3790  * @returns the number of characters printed
3791  */
3792 int
3793 bus_print_child_domain(device_t dev, device_t child)
3794 {
3795 	int domain;
3796 
3797 	/* No domain? Don't print anything */
3798 	if (BUS_GET_DOMAIN(dev, child, &domain) != 0)
3799 		return (0);
3800 
3801 	return (printf(" numa-domain %d", domain));
3802 }
3803 
3804 /**
3805  * @brief Helper function for implementing BUS_PRINT_CHILD().
3806  *
3807  * This function simply calls bus_print_child_header() followed by
3808  * bus_print_child_footer().
3809  *
3810  * @returns the number of characters printed
3811  */
3812 int
3813 bus_generic_print_child(device_t dev, device_t child)
3814 {
3815 	int	retval = 0;
3816 
3817 	retval += bus_print_child_header(dev, child);
3818 	retval += bus_print_child_domain(dev, child);
3819 	retval += bus_print_child_footer(dev, child);
3820 
3821 	return (retval);
3822 }
3823 
3824 /**
3825  * @brief Stub function for implementing BUS_READ_IVAR().
3826  *
3827  * @returns ENOENT
3828  */
3829 int
3830 bus_generic_read_ivar(device_t dev, device_t child, int index,
3831     uintptr_t * result)
3832 {
3833 	return (ENOENT);
3834 }
3835 
3836 /**
3837  * @brief Stub function for implementing BUS_WRITE_IVAR().
3838  *
3839  * @returns ENOENT
3840  */
3841 int
3842 bus_generic_write_ivar(device_t dev, device_t child, int index,
3843     uintptr_t value)
3844 {
3845 	return (ENOENT);
3846 }
3847 
3848 /**
3849  * @brief Stub function for implementing BUS_GET_RESOURCE_LIST().
3850  *
3851  * @returns NULL
3852  */
3853 struct resource_list *
3854 bus_generic_get_resource_list(device_t dev, device_t child)
3855 {
3856 	return (NULL);
3857 }
3858 
3859 /**
3860  * @brief Helper function for implementing BUS_DRIVER_ADDED().
3861  *
3862  * This implementation of BUS_DRIVER_ADDED() simply calls the driver's
3863  * DEVICE_IDENTIFY() method to allow it to add new children to the bus
3864  * and then calls device_probe_and_attach() for each unattached child.
3865  */
3866 void
3867 bus_generic_driver_added(device_t dev, driver_t *driver)
3868 {
3869 	device_t child;
3870 
3871 	DEVICE_IDENTIFY(driver, dev);
3872 	TAILQ_FOREACH(child, &dev->children, link) {
3873 		if (child->state == DS_NOTPRESENT ||
3874 		    (child->flags & DF_REBID))
3875 			device_probe_and_attach(child);
3876 	}
3877 }
3878 
3879 /**
3880  * @brief Helper function for implementing BUS_NEW_PASS().
3881  *
3882  * This implementing of BUS_NEW_PASS() first calls the identify
3883  * routines for any drivers that probe at the current pass.  Then it
3884  * walks the list of devices for this bus.  If a device is already
3885  * attached, then it calls BUS_NEW_PASS() on that device.  If the
3886  * device is not already attached, it attempts to attach a driver to
3887  * it.
3888  */
3889 void
3890 bus_generic_new_pass(device_t dev)
3891 {
3892 	driverlink_t dl;
3893 	devclass_t dc;
3894 	device_t child;
3895 
3896 	dc = dev->devclass;
3897 	TAILQ_FOREACH(dl, &dc->drivers, link) {
3898 		if (dl->pass == bus_current_pass)
3899 			DEVICE_IDENTIFY(dl->driver, dev);
3900 	}
3901 	TAILQ_FOREACH(child, &dev->children, link) {
3902 		if (child->state >= DS_ATTACHED)
3903 			BUS_NEW_PASS(child);
3904 		else if (child->state == DS_NOTPRESENT)
3905 			device_probe_and_attach(child);
3906 	}
3907 }
3908 
3909 /**
3910  * @brief Helper function for implementing BUS_SETUP_INTR().
3911  *
3912  * This simple implementation of BUS_SETUP_INTR() simply calls the
3913  * BUS_SETUP_INTR() method of the parent of @p dev.
3914  */
3915 int
3916 bus_generic_setup_intr(device_t dev, device_t child, struct resource *irq,
3917     int flags, driver_filter_t *filter, driver_intr_t *intr, void *arg,
3918     void **cookiep)
3919 {
3920 	/* Propagate up the bus hierarchy until someone handles it. */
3921 	if (dev->parent)
3922 		return (BUS_SETUP_INTR(dev->parent, child, irq, flags,
3923 		    filter, intr, arg, cookiep));
3924 	return (EINVAL);
3925 }
3926 
3927 /**
3928  * @brief Helper function for implementing BUS_TEARDOWN_INTR().
3929  *
3930  * This simple implementation of BUS_TEARDOWN_INTR() simply calls the
3931  * BUS_TEARDOWN_INTR() method of the parent of @p dev.
3932  */
3933 int
3934 bus_generic_teardown_intr(device_t dev, device_t child, struct resource *irq,
3935     void *cookie)
3936 {
3937 	/* Propagate up the bus hierarchy until someone handles it. */
3938 	if (dev->parent)
3939 		return (BUS_TEARDOWN_INTR(dev->parent, child, irq, cookie));
3940 	return (EINVAL);
3941 }
3942 
3943 /**
3944  * @brief Helper function for implementing BUS_ADJUST_RESOURCE().
3945  *
3946  * This simple implementation of BUS_ADJUST_RESOURCE() simply calls the
3947  * BUS_ADJUST_RESOURCE() method of the parent of @p dev.
3948  */
3949 int
3950 bus_generic_adjust_resource(device_t dev, device_t child, int type,
3951     struct resource *r, u_long start, u_long end)
3952 {
3953 	/* Propagate up the bus hierarchy until someone handles it. */
3954 	if (dev->parent)
3955 		return (BUS_ADJUST_RESOURCE(dev->parent, child, type, r, start,
3956 		    end));
3957 	return (EINVAL);
3958 }
3959 
3960 /**
3961  * @brief Helper function for implementing BUS_ALLOC_RESOURCE().
3962  *
3963  * This simple implementation of BUS_ALLOC_RESOURCE() simply calls the
3964  * BUS_ALLOC_RESOURCE() method of the parent of @p dev.
3965  */
3966 struct resource *
3967 bus_generic_alloc_resource(device_t dev, device_t child, int type, int *rid,
3968     u_long start, u_long end, u_long count, u_int flags)
3969 {
3970 	/* Propagate up the bus hierarchy until someone handles it. */
3971 	if (dev->parent)
3972 		return (BUS_ALLOC_RESOURCE(dev->parent, child, type, rid,
3973 		    start, end, count, flags));
3974 	return (NULL);
3975 }
3976 
3977 /**
3978  * @brief Helper function for implementing BUS_RELEASE_RESOURCE().
3979  *
3980  * This simple implementation of BUS_RELEASE_RESOURCE() simply calls the
3981  * BUS_RELEASE_RESOURCE() method of the parent of @p dev.
3982  */
3983 int
3984 bus_generic_release_resource(device_t dev, device_t child, int type, int rid,
3985     struct resource *r)
3986 {
3987 	/* Propagate up the bus hierarchy until someone handles it. */
3988 	if (dev->parent)
3989 		return (BUS_RELEASE_RESOURCE(dev->parent, child, type, rid,
3990 		    r));
3991 	return (EINVAL);
3992 }
3993 
3994 /**
3995  * @brief Helper function for implementing BUS_ACTIVATE_RESOURCE().
3996  *
3997  * This simple implementation of BUS_ACTIVATE_RESOURCE() simply calls the
3998  * BUS_ACTIVATE_RESOURCE() method of the parent of @p dev.
3999  */
4000 int
4001 bus_generic_activate_resource(device_t dev, device_t child, int type, int rid,
4002     struct resource *r)
4003 {
4004 	/* Propagate up the bus hierarchy until someone handles it. */
4005 	if (dev->parent)
4006 		return (BUS_ACTIVATE_RESOURCE(dev->parent, child, type, rid,
4007 		    r));
4008 	return (EINVAL);
4009 }
4010 
4011 /**
4012  * @brief Helper function for implementing BUS_DEACTIVATE_RESOURCE().
4013  *
4014  * This simple implementation of BUS_DEACTIVATE_RESOURCE() simply calls the
4015  * BUS_DEACTIVATE_RESOURCE() method of the parent of @p dev.
4016  */
4017 int
4018 bus_generic_deactivate_resource(device_t dev, device_t child, int type,
4019     int rid, struct resource *r)
4020 {
4021 	/* Propagate up the bus hierarchy until someone handles it. */
4022 	if (dev->parent)
4023 		return (BUS_DEACTIVATE_RESOURCE(dev->parent, child, type, rid,
4024 		    r));
4025 	return (EINVAL);
4026 }
4027 
4028 /**
4029  * @brief Helper function for implementing BUS_BIND_INTR().
4030  *
4031  * This simple implementation of BUS_BIND_INTR() simply calls the
4032  * BUS_BIND_INTR() method of the parent of @p dev.
4033  */
4034 int
4035 bus_generic_bind_intr(device_t dev, device_t child, struct resource *irq,
4036     int cpu)
4037 {
4038 
4039 	/* Propagate up the bus hierarchy until someone handles it. */
4040 	if (dev->parent)
4041 		return (BUS_BIND_INTR(dev->parent, child, irq, cpu));
4042 	return (EINVAL);
4043 }
4044 
4045 /**
4046  * @brief Helper function for implementing BUS_CONFIG_INTR().
4047  *
4048  * This simple implementation of BUS_CONFIG_INTR() simply calls the
4049  * BUS_CONFIG_INTR() method of the parent of @p dev.
4050  */
4051 int
4052 bus_generic_config_intr(device_t dev, int irq, enum intr_trigger trig,
4053     enum intr_polarity pol)
4054 {
4055 
4056 	/* Propagate up the bus hierarchy until someone handles it. */
4057 	if (dev->parent)
4058 		return (BUS_CONFIG_INTR(dev->parent, irq, trig, pol));
4059 	return (EINVAL);
4060 }
4061 
4062 /**
4063  * @brief Helper function for implementing BUS_DESCRIBE_INTR().
4064  *
4065  * This simple implementation of BUS_DESCRIBE_INTR() simply calls the
4066  * BUS_DESCRIBE_INTR() method of the parent of @p dev.
4067  */
4068 int
4069 bus_generic_describe_intr(device_t dev, device_t child, struct resource *irq,
4070     void *cookie, const char *descr)
4071 {
4072 
4073 	/* Propagate up the bus hierarchy until someone handles it. */
4074 	if (dev->parent)
4075 		return (BUS_DESCRIBE_INTR(dev->parent, child, irq, cookie,
4076 		    descr));
4077 	return (EINVAL);
4078 }
4079 
4080 /**
4081  * @brief Helper function for implementing BUS_GET_DMA_TAG().
4082  *
4083  * This simple implementation of BUS_GET_DMA_TAG() simply calls the
4084  * BUS_GET_DMA_TAG() method of the parent of @p dev.
4085  */
4086 bus_dma_tag_t
4087 bus_generic_get_dma_tag(device_t dev, device_t child)
4088 {
4089 
4090 	/* Propagate up the bus hierarchy until someone handles it. */
4091 	if (dev->parent != NULL)
4092 		return (BUS_GET_DMA_TAG(dev->parent, child));
4093 	return (NULL);
4094 }
4095 
4096 /**
4097  * @brief Helper function for implementing BUS_GET_RESOURCE().
4098  *
4099  * This implementation of BUS_GET_RESOURCE() uses the
4100  * resource_list_find() function to do most of the work. It calls
4101  * BUS_GET_RESOURCE_LIST() to find a suitable resource list to
4102  * search.
4103  */
4104 int
4105 bus_generic_rl_get_resource(device_t dev, device_t child, int type, int rid,
4106     u_long *startp, u_long *countp)
4107 {
4108 	struct resource_list *		rl = NULL;
4109 	struct resource_list_entry *	rle = NULL;
4110 
4111 	rl = BUS_GET_RESOURCE_LIST(dev, child);
4112 	if (!rl)
4113 		return (EINVAL);
4114 
4115 	rle = resource_list_find(rl, type, rid);
4116 	if (!rle)
4117 		return (ENOENT);
4118 
4119 	if (startp)
4120 		*startp = rle->start;
4121 	if (countp)
4122 		*countp = rle->count;
4123 
4124 	return (0);
4125 }
4126 
4127 /**
4128  * @brief Helper function for implementing BUS_SET_RESOURCE().
4129  *
4130  * This implementation of BUS_SET_RESOURCE() uses the
4131  * resource_list_add() function to do most of the work. It calls
4132  * BUS_GET_RESOURCE_LIST() to find a suitable resource list to
4133  * edit.
4134  */
4135 int
4136 bus_generic_rl_set_resource(device_t dev, device_t child, int type, int rid,
4137     u_long start, u_long count)
4138 {
4139 	struct resource_list *		rl = NULL;
4140 
4141 	rl = BUS_GET_RESOURCE_LIST(dev, child);
4142 	if (!rl)
4143 		return (EINVAL);
4144 
4145 	resource_list_add(rl, type, rid, start, (start + count - 1), count);
4146 
4147 	return (0);
4148 }
4149 
4150 /**
4151  * @brief Helper function for implementing BUS_DELETE_RESOURCE().
4152  *
4153  * This implementation of BUS_DELETE_RESOURCE() uses the
4154  * resource_list_delete() function to do most of the work. It calls
4155  * BUS_GET_RESOURCE_LIST() to find a suitable resource list to
4156  * edit.
4157  */
4158 void
4159 bus_generic_rl_delete_resource(device_t dev, device_t child, int type, int rid)
4160 {
4161 	struct resource_list *		rl = NULL;
4162 
4163 	rl = BUS_GET_RESOURCE_LIST(dev, child);
4164 	if (!rl)
4165 		return;
4166 
4167 	resource_list_delete(rl, type, rid);
4168 
4169 	return;
4170 }
4171 
4172 /**
4173  * @brief Helper function for implementing BUS_RELEASE_RESOURCE().
4174  *
4175  * This implementation of BUS_RELEASE_RESOURCE() uses the
4176  * resource_list_release() function to do most of the work. It calls
4177  * BUS_GET_RESOURCE_LIST() to find a suitable resource list.
4178  */
4179 int
4180 bus_generic_rl_release_resource(device_t dev, device_t child, int type,
4181     int rid, struct resource *r)
4182 {
4183 	struct resource_list *		rl = NULL;
4184 
4185 	if (device_get_parent(child) != dev)
4186 		return (BUS_RELEASE_RESOURCE(device_get_parent(dev), child,
4187 		    type, rid, r));
4188 
4189 	rl = BUS_GET_RESOURCE_LIST(dev, child);
4190 	if (!rl)
4191 		return (EINVAL);
4192 
4193 	return (resource_list_release(rl, dev, child, type, rid, r));
4194 }
4195 
4196 /**
4197  * @brief Helper function for implementing BUS_ALLOC_RESOURCE().
4198  *
4199  * This implementation of BUS_ALLOC_RESOURCE() uses the
4200  * resource_list_alloc() function to do most of the work. It calls
4201  * BUS_GET_RESOURCE_LIST() to find a suitable resource list.
4202  */
4203 struct resource *
4204 bus_generic_rl_alloc_resource(device_t dev, device_t child, int type,
4205     int *rid, u_long start, u_long end, u_long count, u_int flags)
4206 {
4207 	struct resource_list *		rl = NULL;
4208 
4209 	if (device_get_parent(child) != dev)
4210 		return (BUS_ALLOC_RESOURCE(device_get_parent(dev), child,
4211 		    type, rid, start, end, count, flags));
4212 
4213 	rl = BUS_GET_RESOURCE_LIST(dev, child);
4214 	if (!rl)
4215 		return (NULL);
4216 
4217 	return (resource_list_alloc(rl, dev, child, type, rid,
4218 	    start, end, count, flags));
4219 }
4220 
4221 /**
4222  * @brief Helper function for implementing BUS_CHILD_PRESENT().
4223  *
4224  * This simple implementation of BUS_CHILD_PRESENT() simply calls the
4225  * BUS_CHILD_PRESENT() method of the parent of @p dev.
4226  */
4227 int
4228 bus_generic_child_present(device_t dev, device_t child)
4229 {
4230 	return (BUS_CHILD_PRESENT(device_get_parent(dev), dev));
4231 }
4232 
4233 int
4234 bus_generic_get_domain(device_t dev, device_t child, int *domain)
4235 {
4236 
4237 	if (dev->parent)
4238 		return (BUS_GET_DOMAIN(dev->parent, dev, domain));
4239 
4240 	return (ENOENT);
4241 }
4242 
4243 /*
4244  * Some convenience functions to make it easier for drivers to use the
4245  * resource-management functions.  All these really do is hide the
4246  * indirection through the parent's method table, making for slightly
4247  * less-wordy code.  In the future, it might make sense for this code
4248  * to maintain some sort of a list of resources allocated by each device.
4249  */
4250 
4251 int
4252 bus_alloc_resources(device_t dev, struct resource_spec *rs,
4253     struct resource **res)
4254 {
4255 	int i;
4256 
4257 	for (i = 0; rs[i].type != -1; i++)
4258 		res[i] = NULL;
4259 	for (i = 0; rs[i].type != -1; i++) {
4260 		res[i] = bus_alloc_resource_any(dev,
4261 		    rs[i].type, &rs[i].rid, rs[i].flags);
4262 		if (res[i] == NULL && !(rs[i].flags & RF_OPTIONAL)) {
4263 			bus_release_resources(dev, rs, res);
4264 			return (ENXIO);
4265 		}
4266 	}
4267 	return (0);
4268 }
4269 
4270 void
4271 bus_release_resources(device_t dev, const struct resource_spec *rs,
4272     struct resource **res)
4273 {
4274 	int i;
4275 
4276 	for (i = 0; rs[i].type != -1; i++)
4277 		if (res[i] != NULL) {
4278 			bus_release_resource(
4279 			    dev, rs[i].type, rs[i].rid, res[i]);
4280 			res[i] = NULL;
4281 		}
4282 }
4283 
4284 /**
4285  * @brief Wrapper function for BUS_ALLOC_RESOURCE().
4286  *
4287  * This function simply calls the BUS_ALLOC_RESOURCE() method of the
4288  * parent of @p dev.
4289  */
4290 struct resource *
4291 bus_alloc_resource(device_t dev, int type, int *rid, u_long start, u_long end,
4292     u_long count, u_int flags)
4293 {
4294 	if (dev->parent == NULL)
4295 		return (NULL);
4296 	return (BUS_ALLOC_RESOURCE(dev->parent, dev, type, rid, start, end,
4297 	    count, flags));
4298 }
4299 
4300 /**
4301  * @brief Wrapper function for BUS_ADJUST_RESOURCE().
4302  *
4303  * This function simply calls the BUS_ADJUST_RESOURCE() method of the
4304  * parent of @p dev.
4305  */
4306 int
4307 bus_adjust_resource(device_t dev, int type, struct resource *r, u_long start,
4308     u_long end)
4309 {
4310 	if (dev->parent == NULL)
4311 		return (EINVAL);
4312 	return (BUS_ADJUST_RESOURCE(dev->parent, dev, type, r, start, end));
4313 }
4314 
4315 /**
4316  * @brief Wrapper function for BUS_ACTIVATE_RESOURCE().
4317  *
4318  * This function simply calls the BUS_ACTIVATE_RESOURCE() method of the
4319  * parent of @p dev.
4320  */
4321 int
4322 bus_activate_resource(device_t dev, int type, int rid, struct resource *r)
4323 {
4324 	if (dev->parent == NULL)
4325 		return (EINVAL);
4326 	return (BUS_ACTIVATE_RESOURCE(dev->parent, dev, type, rid, r));
4327 }
4328 
4329 /**
4330  * @brief Wrapper function for BUS_DEACTIVATE_RESOURCE().
4331  *
4332  * This function simply calls the BUS_DEACTIVATE_RESOURCE() method of the
4333  * parent of @p dev.
4334  */
4335 int
4336 bus_deactivate_resource(device_t dev, int type, int rid, struct resource *r)
4337 {
4338 	if (dev->parent == NULL)
4339 		return (EINVAL);
4340 	return (BUS_DEACTIVATE_RESOURCE(dev->parent, dev, type, rid, r));
4341 }
4342 
4343 /**
4344  * @brief Wrapper function for BUS_RELEASE_RESOURCE().
4345  *
4346  * This function simply calls the BUS_RELEASE_RESOURCE() method of the
4347  * parent of @p dev.
4348  */
4349 int
4350 bus_release_resource(device_t dev, int type, int rid, struct resource *r)
4351 {
4352 	if (dev->parent == NULL)
4353 		return (EINVAL);
4354 	return (BUS_RELEASE_RESOURCE(dev->parent, dev, type, rid, r));
4355 }
4356 
4357 /**
4358  * @brief Wrapper function for BUS_SETUP_INTR().
4359  *
4360  * This function simply calls the BUS_SETUP_INTR() method of the
4361  * parent of @p dev.
4362  */
4363 int
4364 bus_setup_intr(device_t dev, struct resource *r, int flags,
4365     driver_filter_t filter, driver_intr_t handler, void *arg, void **cookiep)
4366 {
4367 	int error;
4368 
4369 	if (dev->parent == NULL)
4370 		return (EINVAL);
4371 	error = BUS_SETUP_INTR(dev->parent, dev, r, flags, filter, handler,
4372 	    arg, cookiep);
4373 	if (error != 0)
4374 		return (error);
4375 	if (handler != NULL && !(flags & INTR_MPSAFE))
4376 		device_printf(dev, "[GIANT-LOCKED]\n");
4377 	return (0);
4378 }
4379 
4380 /**
4381  * @brief Wrapper function for BUS_TEARDOWN_INTR().
4382  *
4383  * This function simply calls the BUS_TEARDOWN_INTR() method of the
4384  * parent of @p dev.
4385  */
4386 int
4387 bus_teardown_intr(device_t dev, struct resource *r, void *cookie)
4388 {
4389 	if (dev->parent == NULL)
4390 		return (EINVAL);
4391 	return (BUS_TEARDOWN_INTR(dev->parent, dev, r, cookie));
4392 }
4393 
4394 /**
4395  * @brief Wrapper function for BUS_BIND_INTR().
4396  *
4397  * This function simply calls the BUS_BIND_INTR() method of the
4398  * parent of @p dev.
4399  */
4400 int
4401 bus_bind_intr(device_t dev, struct resource *r, int cpu)
4402 {
4403 	if (dev->parent == NULL)
4404 		return (EINVAL);
4405 	return (BUS_BIND_INTR(dev->parent, dev, r, cpu));
4406 }
4407 
4408 /**
4409  * @brief Wrapper function for BUS_DESCRIBE_INTR().
4410  *
4411  * This function first formats the requested description into a
4412  * temporary buffer and then calls the BUS_DESCRIBE_INTR() method of
4413  * the parent of @p dev.
4414  */
4415 int
4416 bus_describe_intr(device_t dev, struct resource *irq, void *cookie,
4417     const char *fmt, ...)
4418 {
4419 	va_list ap;
4420 	char descr[MAXCOMLEN + 1];
4421 
4422 	if (dev->parent == NULL)
4423 		return (EINVAL);
4424 	va_start(ap, fmt);
4425 	vsnprintf(descr, sizeof(descr), fmt, ap);
4426 	va_end(ap);
4427 	return (BUS_DESCRIBE_INTR(dev->parent, dev, irq, cookie, descr));
4428 }
4429 
4430 /**
4431  * @brief Wrapper function for BUS_SET_RESOURCE().
4432  *
4433  * This function simply calls the BUS_SET_RESOURCE() method of the
4434  * parent of @p dev.
4435  */
4436 int
4437 bus_set_resource(device_t dev, int type, int rid,
4438     u_long start, u_long count)
4439 {
4440 	return (BUS_SET_RESOURCE(device_get_parent(dev), dev, type, rid,
4441 	    start, count));
4442 }
4443 
4444 /**
4445  * @brief Wrapper function for BUS_GET_RESOURCE().
4446  *
4447  * This function simply calls the BUS_GET_RESOURCE() method of the
4448  * parent of @p dev.
4449  */
4450 int
4451 bus_get_resource(device_t dev, int type, int rid,
4452     u_long *startp, u_long *countp)
4453 {
4454 	return (BUS_GET_RESOURCE(device_get_parent(dev), dev, type, rid,
4455 	    startp, countp));
4456 }
4457 
4458 /**
4459  * @brief Wrapper function for BUS_GET_RESOURCE().
4460  *
4461  * This function simply calls the BUS_GET_RESOURCE() method of the
4462  * parent of @p dev and returns the start value.
4463  */
4464 u_long
4465 bus_get_resource_start(device_t dev, int type, int rid)
4466 {
4467 	u_long start, count;
4468 	int error;
4469 
4470 	error = BUS_GET_RESOURCE(device_get_parent(dev), dev, type, rid,
4471 	    &start, &count);
4472 	if (error)
4473 		return (0);
4474 	return (start);
4475 }
4476 
4477 /**
4478  * @brief Wrapper function for BUS_GET_RESOURCE().
4479  *
4480  * This function simply calls the BUS_GET_RESOURCE() method of the
4481  * parent of @p dev and returns the count value.
4482  */
4483 u_long
4484 bus_get_resource_count(device_t dev, int type, int rid)
4485 {
4486 	u_long start, count;
4487 	int error;
4488 
4489 	error = BUS_GET_RESOURCE(device_get_parent(dev), dev, type, rid,
4490 	    &start, &count);
4491 	if (error)
4492 		return (0);
4493 	return (count);
4494 }
4495 
4496 /**
4497  * @brief Wrapper function for BUS_DELETE_RESOURCE().
4498  *
4499  * This function simply calls the BUS_DELETE_RESOURCE() method of the
4500  * parent of @p dev.
4501  */
4502 void
4503 bus_delete_resource(device_t dev, int type, int rid)
4504 {
4505 	BUS_DELETE_RESOURCE(device_get_parent(dev), dev, type, rid);
4506 }
4507 
4508 /**
4509  * @brief Wrapper function for BUS_CHILD_PRESENT().
4510  *
4511  * This function simply calls the BUS_CHILD_PRESENT() method of the
4512  * parent of @p dev.
4513  */
4514 int
4515 bus_child_present(device_t child)
4516 {
4517 	return (BUS_CHILD_PRESENT(device_get_parent(child), child));
4518 }
4519 
4520 /**
4521  * @brief Wrapper function for BUS_CHILD_PNPINFO_STR().
4522  *
4523  * This function simply calls the BUS_CHILD_PNPINFO_STR() method of the
4524  * parent of @p dev.
4525  */
4526 int
4527 bus_child_pnpinfo_str(device_t child, char *buf, size_t buflen)
4528 {
4529 	device_t parent;
4530 
4531 	parent = device_get_parent(child);
4532 	if (parent == NULL) {
4533 		*buf = '\0';
4534 		return (0);
4535 	}
4536 	return (BUS_CHILD_PNPINFO_STR(parent, child, buf, buflen));
4537 }
4538 
4539 /**
4540  * @brief Wrapper function for BUS_CHILD_LOCATION_STR().
4541  *
4542  * This function simply calls the BUS_CHILD_LOCATION_STR() method of the
4543  * parent of @p dev.
4544  */
4545 int
4546 bus_child_location_str(device_t child, char *buf, size_t buflen)
4547 {
4548 	device_t parent;
4549 
4550 	parent = device_get_parent(child);
4551 	if (parent == NULL) {
4552 		*buf = '\0';
4553 		return (0);
4554 	}
4555 	return (BUS_CHILD_LOCATION_STR(parent, child, buf, buflen));
4556 }
4557 
4558 /**
4559  * @brief Wrapper function for BUS_GET_DMA_TAG().
4560  *
4561  * This function simply calls the BUS_GET_DMA_TAG() method of the
4562  * parent of @p dev.
4563  */
4564 bus_dma_tag_t
4565 bus_get_dma_tag(device_t dev)
4566 {
4567 	device_t parent;
4568 
4569 	parent = device_get_parent(dev);
4570 	if (parent == NULL)
4571 		return (NULL);
4572 	return (BUS_GET_DMA_TAG(parent, dev));
4573 }
4574 
4575 /**
4576  * @brief Wrapper function for BUS_GET_DOMAIN().
4577  *
4578  * This function simply calls the BUS_GET_DOMAIN() method of the
4579  * parent of @p dev.
4580  */
4581 int
4582 bus_get_domain(device_t dev, int *domain)
4583 {
4584 	return (BUS_GET_DOMAIN(device_get_parent(dev), dev, domain));
4585 }
4586 
4587 /* Resume all devices and then notify userland that we're up again. */
4588 static int
4589 root_resume(device_t dev)
4590 {
4591 	int error;
4592 
4593 	error = bus_generic_resume(dev);
4594 	if (error == 0)
4595 		devctl_notify("kern", "power", "resume", NULL);
4596 	return (error);
4597 }
4598 
4599 static int
4600 root_print_child(device_t dev, device_t child)
4601 {
4602 	int	retval = 0;
4603 
4604 	retval += bus_print_child_header(dev, child);
4605 	retval += printf("\n");
4606 
4607 	return (retval);
4608 }
4609 
4610 static int
4611 root_setup_intr(device_t dev, device_t child, struct resource *irq, int flags,
4612     driver_filter_t *filter, driver_intr_t *intr, void *arg, void **cookiep)
4613 {
4614 	/*
4615 	 * If an interrupt mapping gets to here something bad has happened.
4616 	 */
4617 	panic("root_setup_intr");
4618 }
4619 
4620 /*
4621  * If we get here, assume that the device is permanant and really is
4622  * present in the system.  Removable bus drivers are expected to intercept
4623  * this call long before it gets here.  We return -1 so that drivers that
4624  * really care can check vs -1 or some ERRNO returned higher in the food
4625  * chain.
4626  */
4627 static int
4628 root_child_present(device_t dev, device_t child)
4629 {
4630 	return (-1);
4631 }
4632 
4633 static kobj_method_t root_methods[] = {
4634 	/* Device interface */
4635 	KOBJMETHOD(device_shutdown,	bus_generic_shutdown),
4636 	KOBJMETHOD(device_suspend,	bus_generic_suspend),
4637 	KOBJMETHOD(device_resume,	root_resume),
4638 
4639 	/* Bus interface */
4640 	KOBJMETHOD(bus_print_child,	root_print_child),
4641 	KOBJMETHOD(bus_read_ivar,	bus_generic_read_ivar),
4642 	KOBJMETHOD(bus_write_ivar,	bus_generic_write_ivar),
4643 	KOBJMETHOD(bus_setup_intr,	root_setup_intr),
4644 	KOBJMETHOD(bus_child_present,	root_child_present),
4645 
4646 	KOBJMETHOD_END
4647 };
4648 
4649 static driver_t root_driver = {
4650 	"root",
4651 	root_methods,
4652 	1,			/* no softc */
4653 };
4654 
4655 device_t	root_bus;
4656 devclass_t	root_devclass;
4657 
4658 static int
4659 root_bus_module_handler(module_t mod, int what, void* arg)
4660 {
4661 	switch (what) {
4662 	case MOD_LOAD:
4663 		TAILQ_INIT(&bus_data_devices);
4664 		kobj_class_compile((kobj_class_t) &root_driver);
4665 		root_bus = make_device(NULL, "root", 0);
4666 		root_bus->desc = "System root bus";
4667 		kobj_init((kobj_t) root_bus, (kobj_class_t) &root_driver);
4668 		root_bus->driver = &root_driver;
4669 		root_bus->state = DS_ATTACHED;
4670 		root_devclass = devclass_find_internal("root", NULL, FALSE);
4671 		devinit();
4672 		return (0);
4673 
4674 	case MOD_SHUTDOWN:
4675 		device_shutdown(root_bus);
4676 		return (0);
4677 	default:
4678 		return (EOPNOTSUPP);
4679 	}
4680 
4681 	return (0);
4682 }
4683 
4684 static moduledata_t root_bus_mod = {
4685 	"rootbus",
4686 	root_bus_module_handler,
4687 	NULL
4688 };
4689 DECLARE_MODULE(rootbus, root_bus_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
4690 
4691 /**
4692  * @brief Automatically configure devices
4693  *
4694  * This function begins the autoconfiguration process by calling
4695  * device_probe_and_attach() for each child of the @c root0 device.
4696  */
4697 void
4698 root_bus_configure(void)
4699 {
4700 
4701 	PDEBUG(("."));
4702 
4703 	/* Eventually this will be split up, but this is sufficient for now. */
4704 	bus_set_pass(BUS_PASS_DEFAULT);
4705 }
4706 
4707 /**
4708  * @brief Module handler for registering device drivers
4709  *
4710  * This module handler is used to automatically register device
4711  * drivers when modules are loaded. If @p what is MOD_LOAD, it calls
4712  * devclass_add_driver() for the driver described by the
4713  * driver_module_data structure pointed to by @p arg
4714  */
4715 int
4716 driver_module_handler(module_t mod, int what, void *arg)
4717 {
4718 	struct driver_module_data *dmd;
4719 	devclass_t bus_devclass;
4720 	kobj_class_t driver;
4721 	int error, pass;
4722 
4723 	dmd = (struct driver_module_data *)arg;
4724 	bus_devclass = devclass_find_internal(dmd->dmd_busname, NULL, TRUE);
4725 	error = 0;
4726 
4727 	switch (what) {
4728 	case MOD_LOAD:
4729 		if (dmd->dmd_chainevh)
4730 			error = dmd->dmd_chainevh(mod,what,dmd->dmd_chainarg);
4731 
4732 		pass = dmd->dmd_pass;
4733 		driver = dmd->dmd_driver;
4734 		PDEBUG(("Loading module: driver %s on bus %s (pass %d)",
4735 		    DRIVERNAME(driver), dmd->dmd_busname, pass));
4736 		error = devclass_add_driver(bus_devclass, driver, pass,
4737 		    dmd->dmd_devclass);
4738 		break;
4739 
4740 	case MOD_UNLOAD:
4741 		PDEBUG(("Unloading module: driver %s from bus %s",
4742 		    DRIVERNAME(dmd->dmd_driver),
4743 		    dmd->dmd_busname));
4744 		error = devclass_delete_driver(bus_devclass,
4745 		    dmd->dmd_driver);
4746 
4747 		if (!error && dmd->dmd_chainevh)
4748 			error = dmd->dmd_chainevh(mod,what,dmd->dmd_chainarg);
4749 		break;
4750 	case MOD_QUIESCE:
4751 		PDEBUG(("Quiesce module: driver %s from bus %s",
4752 		    DRIVERNAME(dmd->dmd_driver),
4753 		    dmd->dmd_busname));
4754 		error = devclass_quiesce_driver(bus_devclass,
4755 		    dmd->dmd_driver);
4756 
4757 		if (!error && dmd->dmd_chainevh)
4758 			error = dmd->dmd_chainevh(mod,what,dmd->dmd_chainarg);
4759 		break;
4760 	default:
4761 		error = EOPNOTSUPP;
4762 		break;
4763 	}
4764 
4765 	return (error);
4766 }
4767 
4768 /**
4769  * @brief Enumerate all hinted devices for this bus.
4770  *
4771  * Walks through the hints for this bus and calls the bus_hinted_child
4772  * routine for each one it fines.  It searches first for the specific
4773  * bus that's being probed for hinted children (eg isa0), and then for
4774  * generic children (eg isa).
4775  *
4776  * @param	dev	bus device to enumerate
4777  */
4778 void
4779 bus_enumerate_hinted_children(device_t bus)
4780 {
4781 	int i;
4782 	const char *dname, *busname;
4783 	int dunit;
4784 
4785 	/*
4786 	 * enumerate all devices on the specific bus
4787 	 */
4788 	busname = device_get_nameunit(bus);
4789 	i = 0;
4790 	while (resource_find_match(&i, &dname, &dunit, "at", busname) == 0)
4791 		BUS_HINTED_CHILD(bus, dname, dunit);
4792 
4793 	/*
4794 	 * and all the generic ones.
4795 	 */
4796 	busname = device_get_name(bus);
4797 	i = 0;
4798 	while (resource_find_match(&i, &dname, &dunit, "at", busname) == 0)
4799 		BUS_HINTED_CHILD(bus, dname, dunit);
4800 }
4801 
4802 #ifdef BUS_DEBUG
4803 
4804 /* the _short versions avoid iteration by not calling anything that prints
4805  * more than oneliners. I love oneliners.
4806  */
4807 
4808 static void
4809 print_device_short(device_t dev, int indent)
4810 {
4811 	if (!dev)
4812 		return;
4813 
4814 	indentprintf(("device %d: <%s> %sparent,%schildren,%s%s%s%s%s,%sivars,%ssoftc,busy=%d\n",
4815 	    dev->unit, dev->desc,
4816 	    (dev->parent? "":"no "),
4817 	    (TAILQ_EMPTY(&dev->children)? "no ":""),
4818 	    (dev->flags&DF_ENABLED? "enabled,":"disabled,"),
4819 	    (dev->flags&DF_FIXEDCLASS? "fixed,":""),
4820 	    (dev->flags&DF_WILDCARD? "wildcard,":""),
4821 	    (dev->flags&DF_DESCMALLOCED? "descmalloced,":""),
4822 	    (dev->flags&DF_REBID? "rebiddable,":""),
4823 	    (dev->ivars? "":"no "),
4824 	    (dev->softc? "":"no "),
4825 	    dev->busy));
4826 }
4827 
4828 static void
4829 print_device(device_t dev, int indent)
4830 {
4831 	if (!dev)
4832 		return;
4833 
4834 	print_device_short(dev, indent);
4835 
4836 	indentprintf(("Parent:\n"));
4837 	print_device_short(dev->parent, indent+1);
4838 	indentprintf(("Driver:\n"));
4839 	print_driver_short(dev->driver, indent+1);
4840 	indentprintf(("Devclass:\n"));
4841 	print_devclass_short(dev->devclass, indent+1);
4842 }
4843 
4844 void
4845 print_device_tree_short(device_t dev, int indent)
4846 /* print the device and all its children (indented) */
4847 {
4848 	device_t child;
4849 
4850 	if (!dev)
4851 		return;
4852 
4853 	print_device_short(dev, indent);
4854 
4855 	TAILQ_FOREACH(child, &dev->children, link) {
4856 		print_device_tree_short(child, indent+1);
4857 	}
4858 }
4859 
4860 void
4861 print_device_tree(device_t dev, int indent)
4862 /* print the device and all its children (indented) */
4863 {
4864 	device_t child;
4865 
4866 	if (!dev)
4867 		return;
4868 
4869 	print_device(dev, indent);
4870 
4871 	TAILQ_FOREACH(child, &dev->children, link) {
4872 		print_device_tree(child, indent+1);
4873 	}
4874 }
4875 
4876 static void
4877 print_driver_short(driver_t *driver, int indent)
4878 {
4879 	if (!driver)
4880 		return;
4881 
4882 	indentprintf(("driver %s: softc size = %zd\n",
4883 	    driver->name, driver->size));
4884 }
4885 
4886 static void
4887 print_driver(driver_t *driver, int indent)
4888 {
4889 	if (!driver)
4890 		return;
4891 
4892 	print_driver_short(driver, indent);
4893 }
4894 
4895 static void
4896 print_driver_list(driver_list_t drivers, int indent)
4897 {
4898 	driverlink_t driver;
4899 
4900 	TAILQ_FOREACH(driver, &drivers, link) {
4901 		print_driver(driver->driver, indent);
4902 	}
4903 }
4904 
4905 static void
4906 print_devclass_short(devclass_t dc, int indent)
4907 {
4908 	if ( !dc )
4909 		return;
4910 
4911 	indentprintf(("devclass %s: max units = %d\n", dc->name, dc->maxunit));
4912 }
4913 
4914 static void
4915 print_devclass(devclass_t dc, int indent)
4916 {
4917 	int i;
4918 
4919 	if ( !dc )
4920 		return;
4921 
4922 	print_devclass_short(dc, indent);
4923 	indentprintf(("Drivers:\n"));
4924 	print_driver_list(dc->drivers, indent+1);
4925 
4926 	indentprintf(("Devices:\n"));
4927 	for (i = 0; i < dc->maxunit; i++)
4928 		if (dc->devices[i])
4929 			print_device(dc->devices[i], indent+1);
4930 }
4931 
4932 void
4933 print_devclass_list_short(void)
4934 {
4935 	devclass_t dc;
4936 
4937 	printf("Short listing of devclasses, drivers & devices:\n");
4938 	TAILQ_FOREACH(dc, &devclasses, link) {
4939 		print_devclass_short(dc, 0);
4940 	}
4941 }
4942 
4943 void
4944 print_devclass_list(void)
4945 {
4946 	devclass_t dc;
4947 
4948 	printf("Full listing of devclasses, drivers & devices:\n");
4949 	TAILQ_FOREACH(dc, &devclasses, link) {
4950 		print_devclass(dc, 0);
4951 	}
4952 }
4953 
4954 #endif
4955 
4956 /*
4957  * User-space access to the device tree.
4958  *
4959  * We implement a small set of nodes:
4960  *
4961  * hw.bus			Single integer read method to obtain the
4962  *				current generation count.
4963  * hw.bus.devices		Reads the entire device tree in flat space.
4964  * hw.bus.rman			Resource manager interface
4965  *
4966  * We might like to add the ability to scan devclasses and/or drivers to
4967  * determine what else is currently loaded/available.
4968  */
4969 
4970 static int
4971 sysctl_bus(SYSCTL_HANDLER_ARGS)
4972 {
4973 	struct u_businfo	ubus;
4974 
4975 	ubus.ub_version = BUS_USER_VERSION;
4976 	ubus.ub_generation = bus_data_generation;
4977 
4978 	return (SYSCTL_OUT(req, &ubus, sizeof(ubus)));
4979 }
4980 SYSCTL_NODE(_hw_bus, OID_AUTO, info, CTLFLAG_RW, sysctl_bus,
4981     "bus-related data");
4982 
4983 static int
4984 sysctl_devices(SYSCTL_HANDLER_ARGS)
4985 {
4986 	int			*name = (int *)arg1;
4987 	u_int			namelen = arg2;
4988 	int			index;
4989 	struct device		*dev;
4990 	struct u_device		udev;	/* XXX this is a bit big */
4991 	int			error;
4992 
4993 	if (namelen != 2)
4994 		return (EINVAL);
4995 
4996 	if (bus_data_generation_check(name[0]))
4997 		return (EINVAL);
4998 
4999 	index = name[1];
5000 
5001 	/*
5002 	 * Scan the list of devices, looking for the requested index.
5003 	 */
5004 	TAILQ_FOREACH(dev, &bus_data_devices, devlink) {
5005 		if (index-- == 0)
5006 			break;
5007 	}
5008 	if (dev == NULL)
5009 		return (ENOENT);
5010 
5011 	/*
5012 	 * Populate the return array.
5013 	 */
5014 	bzero(&udev, sizeof(udev));
5015 	udev.dv_handle = (uintptr_t)dev;
5016 	udev.dv_parent = (uintptr_t)dev->parent;
5017 	if (dev->nameunit != NULL)
5018 		strlcpy(udev.dv_name, dev->nameunit, sizeof(udev.dv_name));
5019 	if (dev->desc != NULL)
5020 		strlcpy(udev.dv_desc, dev->desc, sizeof(udev.dv_desc));
5021 	if (dev->driver != NULL && dev->driver->name != NULL)
5022 		strlcpy(udev.dv_drivername, dev->driver->name,
5023 		    sizeof(udev.dv_drivername));
5024 	bus_child_pnpinfo_str(dev, udev.dv_pnpinfo, sizeof(udev.dv_pnpinfo));
5025 	bus_child_location_str(dev, udev.dv_location, sizeof(udev.dv_location));
5026 	udev.dv_devflags = dev->devflags;
5027 	udev.dv_flags = dev->flags;
5028 	udev.dv_state = dev->state;
5029 	error = SYSCTL_OUT(req, &udev, sizeof(udev));
5030 	return (error);
5031 }
5032 
5033 SYSCTL_NODE(_hw_bus, OID_AUTO, devices, CTLFLAG_RD, sysctl_devices,
5034     "system device tree");
5035 
5036 int
5037 bus_data_generation_check(int generation)
5038 {
5039 	if (generation != bus_data_generation)
5040 		return (1);
5041 
5042 	/* XXX generate optimised lists here? */
5043 	return (0);
5044 }
5045 
5046 void
5047 bus_data_generation_update(void)
5048 {
5049 	bus_data_generation++;
5050 }
5051 
5052 int
5053 bus_free_resource(device_t dev, int type, struct resource *r)
5054 {
5055 	if (r == NULL)
5056 		return (0);
5057 	return (bus_release_resource(dev, type, rman_get_rid(r), r));
5058 }
5059 
5060 /*
5061  * /dev/devctl2 implementation.  The existing /dev/devctl device has
5062  * implicit semantics on open, so it could not be reused for this.
5063  * Another option would be to call this /dev/bus?
5064  */
5065 static int
5066 find_device(struct devreq *req, device_t *devp)
5067 {
5068 	device_t dev;
5069 
5070 	/*
5071 	 * First, ensure that the name is nul terminated.
5072 	 */
5073 	if (memchr(req->dr_name, '\0', sizeof(req->dr_name)) == NULL)
5074 		return (EINVAL);
5075 
5076 	/*
5077 	 * Second, try to find an attached device whose name matches
5078 	 * 'name'.
5079 	 */
5080 	TAILQ_FOREACH(dev, &bus_data_devices, devlink) {
5081 		if (dev->nameunit != NULL &&
5082 		    strcmp(dev->nameunit, req->dr_name) == 0) {
5083 			*devp = dev;
5084 			return (0);
5085 		}
5086 	}
5087 
5088 	/* Finally, give device enumerators a chance. */
5089 	dev = NULL;
5090 	EVENTHANDLER_INVOKE(dev_lookup, req->dr_name, &dev);
5091 	if (dev == NULL)
5092 		return (ENOENT);
5093 	*devp = dev;
5094 	return (0);
5095 }
5096 
5097 static bool
5098 driver_exists(struct device *bus, const char *driver)
5099 {
5100 	devclass_t dc;
5101 
5102 	for (dc = bus->devclass; dc != NULL; dc = dc->parent) {
5103 		if (devclass_find_driver_internal(dc, driver) != NULL)
5104 			return (true);
5105 	}
5106 	return (false);
5107 }
5108 
5109 static int
5110 devctl2_ioctl(struct cdev *cdev, u_long cmd, caddr_t data, int fflag,
5111     struct thread *td)
5112 {
5113 	struct devreq *req;
5114 	device_t dev;
5115 	int error, old;
5116 
5117 	/* Locate the device to control. */
5118 	mtx_lock(&Giant);
5119 	req = (struct devreq *)data;
5120 	switch (cmd) {
5121 	case DEV_ATTACH:
5122 	case DEV_DETACH:
5123 	case DEV_ENABLE:
5124 	case DEV_DISABLE:
5125 	case DEV_SUSPEND:
5126 	case DEV_RESUME:
5127 	case DEV_SET_DRIVER:
5128 		error = priv_check(td, PRIV_DRIVER);
5129 		if (error == 0)
5130 			error = find_device(req, &dev);
5131 		break;
5132 	default:
5133 		error = ENOTTY;
5134 		break;
5135 	}
5136 	if (error) {
5137 		mtx_unlock(&Giant);
5138 		return (error);
5139 	}
5140 
5141 	/* Perform the requested operation. */
5142 	switch (cmd) {
5143 	case DEV_ATTACH:
5144 		if (device_is_attached(dev) && (dev->flags & DF_REBID) == 0)
5145 			error = EBUSY;
5146 		else if (!device_is_enabled(dev))
5147 			error = ENXIO;
5148 		else
5149 			error = device_probe_and_attach(dev);
5150 		break;
5151 	case DEV_DETACH:
5152 		if (!device_is_attached(dev)) {
5153 			error = ENXIO;
5154 			break;
5155 		}
5156 		if (!(req->dr_flags & DEVF_FORCE_DETACH)) {
5157 			error = device_quiesce(dev);
5158 			if (error)
5159 				break;
5160 		}
5161 		error = device_detach(dev);
5162 		break;
5163 	case DEV_ENABLE:
5164 		if (device_is_enabled(dev)) {
5165 			error = EBUSY;
5166 			break;
5167 		}
5168 
5169 		/*
5170 		 * If the device has been probed but not attached (e.g.
5171 		 * when it has been disabled by a loader hint), just
5172 		 * attach the device rather than doing a full probe.
5173 		 */
5174 		device_enable(dev);
5175 		if (device_is_alive(dev)) {
5176 			/*
5177 			 * If the device was disabled via a hint, clear
5178 			 * the hint.
5179 			 */
5180 			if (resource_disabled(dev->driver->name, dev->unit))
5181 				resource_unset_value(dev->driver->name,
5182 				    dev->unit, "disabled");
5183 			error = device_attach(dev);
5184 		} else
5185 			error = device_probe_and_attach(dev);
5186 		break;
5187 	case DEV_DISABLE:
5188 		if (!device_is_enabled(dev)) {
5189 			error = ENXIO;
5190 			break;
5191 		}
5192 
5193 		if (!(req->dr_flags & DEVF_FORCE_DETACH)) {
5194 			error = device_quiesce(dev);
5195 			if (error)
5196 				break;
5197 		}
5198 
5199 		/*
5200 		 * Force DF_FIXEDCLASS on around detach to preserve
5201 		 * the existing name.
5202 		 */
5203 		old = dev->flags;
5204 		dev->flags |= DF_FIXEDCLASS;
5205 		error = device_detach(dev);
5206 		if (!(old & DF_FIXEDCLASS))
5207 			dev->flags &= ~DF_FIXEDCLASS;
5208 		if (error == 0)
5209 			device_disable(dev);
5210 		break;
5211 	case DEV_SUSPEND:
5212 		if (device_is_suspended(dev)) {
5213 			error = EBUSY;
5214 			break;
5215 		}
5216 		if (device_get_parent(dev) == NULL) {
5217 			error = EINVAL;
5218 			break;
5219 		}
5220 		error = BUS_SUSPEND_CHILD(device_get_parent(dev), dev);
5221 		break;
5222 	case DEV_RESUME:
5223 		if (!device_is_suspended(dev)) {
5224 			error = EINVAL;
5225 			break;
5226 		}
5227 		if (device_get_parent(dev) == NULL) {
5228 			error = EINVAL;
5229 			break;
5230 		}
5231 		error = BUS_RESUME_CHILD(device_get_parent(dev), dev);
5232 		break;
5233 	case DEV_SET_DRIVER: {
5234 		devclass_t dc;
5235 		char driver[128];
5236 
5237 		error = copyinstr(req->dr_data, driver, sizeof(driver), NULL);
5238 		if (error)
5239 			break;
5240 		if (driver[0] == '\0') {
5241 			error = EINVAL;
5242 			break;
5243 		}
5244 		if (dev->devclass != NULL &&
5245 		    strcmp(driver, dev->devclass->name) == 0)
5246 			/* XXX: Could possibly force DF_FIXEDCLASS on? */
5247 			break;
5248 
5249 		/*
5250 		 * Scan drivers for this device's bus looking for at
5251 		 * least one matching driver.
5252 		 */
5253 		if (dev->parent == NULL) {
5254 			error = EINVAL;
5255 			break;
5256 		}
5257 		if (!driver_exists(dev->parent, driver)) {
5258 			error = ENOENT;
5259 			break;
5260 		}
5261 		dc = devclass_create(driver);
5262 		if (dc == NULL) {
5263 			error = ENOMEM;
5264 			break;
5265 		}
5266 
5267 		/* Detach device if necessary. */
5268 		if (device_is_attached(dev)) {
5269 			if (req->dr_flags & DEVF_SET_DRIVER_DETACH)
5270 				error = device_detach(dev);
5271 			else
5272 				error = EBUSY;
5273 			if (error)
5274 				break;
5275 		}
5276 
5277 		/* Clear any previously-fixed device class and unit. */
5278 		if (dev->flags & DF_FIXEDCLASS)
5279 			devclass_delete_device(dev->devclass, dev);
5280 		dev->flags |= DF_WILDCARD;
5281 		dev->unit = -1;
5282 
5283 		/* Force the new device class. */
5284 		error = devclass_add_device(dc, dev);
5285 		if (error)
5286 			break;
5287 		dev->flags |= DF_FIXEDCLASS;
5288 		error = device_probe_and_attach(dev);
5289 		break;
5290 	}
5291 	}
5292 	mtx_unlock(&Giant);
5293 	return (error);
5294 }
5295 
5296 static struct cdevsw devctl2_cdevsw = {
5297 	.d_version =	D_VERSION,
5298 	.d_ioctl =	devctl2_ioctl,
5299 	.d_name =	"devctl2",
5300 };
5301 
5302 static void
5303 devctl2_init(void)
5304 {
5305 
5306 	make_dev_credf(MAKEDEV_ETERNAL, &devctl2_cdevsw, 0, NULL,
5307 	    UID_ROOT, GID_WHEEL, 0600, "devctl2");
5308 }
5309