xref: /freebsd/sys/kern/subr_bus.c (revision ec0e626bafb335b30c499d06066997f54b10c092)
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 			 * The driver returned an error so it
2117 			 * certainly doesn't match.
2118 			 */
2119 			if (result > 0) {
2120 				(void)device_set_driver(child, NULL);
2121 				continue;
2122 			}
2123 
2124 			/*
2125 			 * A priority lower than SUCCESS, remember the
2126 			 * best matching driver. Initialise the value
2127 			 * of pri for the first match.
2128 			 */
2129 			if (best == NULL || result > pri) {
2130 				/*
2131 				 * Probes that return BUS_PROBE_NOWILDCARD
2132 				 * or lower only match on devices whose
2133 				 * driver was explicitly specified.
2134 				 */
2135 				if (result <= BUS_PROBE_NOWILDCARD &&
2136 				    !(child->flags & DF_FIXEDCLASS))
2137 					continue;
2138 				best = dl;
2139 				pri = result;
2140 				continue;
2141 			}
2142 		}
2143 		/*
2144 		 * If we have an unambiguous match in this devclass,
2145 		 * don't look in the parent.
2146 		 */
2147 		if (best && pri == 0)
2148 			break;
2149 	}
2150 
2151 	/*
2152 	 * If we found a driver, change state and initialise the devclass.
2153 	 */
2154 	/* XXX What happens if we rebid and got no best? */
2155 	if (best) {
2156 		/*
2157 		 * If this device was attached, and we were asked to
2158 		 * rescan, and it is a different driver, then we have
2159 		 * to detach the old driver and reattach this new one.
2160 		 * Note, we don't have to check for DF_REBID here
2161 		 * because if the state is > DS_ALIVE, we know it must
2162 		 * be.
2163 		 *
2164 		 * This assumes that all DF_REBID drivers can have
2165 		 * their probe routine called at any time and that
2166 		 * they are idempotent as well as completely benign in
2167 		 * normal operations.
2168 		 *
2169 		 * We also have to make sure that the detach
2170 		 * succeeded, otherwise we fail the operation (or
2171 		 * maybe it should just fail silently?  I'm torn).
2172 		 */
2173 		if (child->state > DS_ALIVE && best->driver != child->driver)
2174 			if ((result = device_detach(dev)) != 0)
2175 				return (result);
2176 
2177 		/* Set the winning driver, devclass, and flags. */
2178 		if (!child->devclass) {
2179 			result = device_set_devclass(child, best->driver->name);
2180 			if (result != 0)
2181 				return (result);
2182 		}
2183 		result = device_set_driver(child, best->driver);
2184 		if (result != 0)
2185 			return (result);
2186 		resource_int_value(best->driver->name, child->unit,
2187 		    "flags", &child->devflags);
2188 
2189 		if (pri < 0) {
2190 			/*
2191 			 * A bit bogus. Call the probe method again to make
2192 			 * sure that we have the right description.
2193 			 */
2194 			DEVICE_PROBE(child);
2195 #if 0
2196 			child->flags |= DF_REBID;
2197 #endif
2198 		} else
2199 			child->flags &= ~DF_REBID;
2200 		child->state = DS_ALIVE;
2201 
2202 		bus_data_generation_update();
2203 		return (0);
2204 	}
2205 
2206 	return (ENXIO);
2207 }
2208 
2209 /**
2210  * @brief Return the parent of a device
2211  */
2212 device_t
2213 device_get_parent(device_t dev)
2214 {
2215 	return (dev->parent);
2216 }
2217 
2218 /**
2219  * @brief Get a list of children of a device
2220  *
2221  * An array containing a list of all the children of the given device
2222  * is allocated and returned in @p *devlistp. The number of devices
2223  * in the array is returned in @p *devcountp. The caller should free
2224  * the array using @c free(p, M_TEMP).
2225  *
2226  * @param dev		the device to examine
2227  * @param devlistp	points at location for array pointer return
2228  *			value
2229  * @param devcountp	points at location for array size return value
2230  *
2231  * @retval 0		success
2232  * @retval ENOMEM	the array allocation failed
2233  */
2234 int
2235 device_get_children(device_t dev, device_t **devlistp, int *devcountp)
2236 {
2237 	int count;
2238 	device_t child;
2239 	device_t *list;
2240 
2241 	count = 0;
2242 	TAILQ_FOREACH(child, &dev->children, link) {
2243 		count++;
2244 	}
2245 	if (count == 0) {
2246 		*devlistp = NULL;
2247 		*devcountp = 0;
2248 		return (0);
2249 	}
2250 
2251 	list = malloc(count * sizeof(device_t), M_TEMP, M_NOWAIT|M_ZERO);
2252 	if (!list)
2253 		return (ENOMEM);
2254 
2255 	count = 0;
2256 	TAILQ_FOREACH(child, &dev->children, link) {
2257 		list[count] = child;
2258 		count++;
2259 	}
2260 
2261 	*devlistp = list;
2262 	*devcountp = count;
2263 
2264 	return (0);
2265 }
2266 
2267 /**
2268  * @brief Return the current driver for the device or @c NULL if there
2269  * is no driver currently attached
2270  */
2271 driver_t *
2272 device_get_driver(device_t dev)
2273 {
2274 	return (dev->driver);
2275 }
2276 
2277 /**
2278  * @brief Return the current devclass for the device or @c NULL if
2279  * there is none.
2280  */
2281 devclass_t
2282 device_get_devclass(device_t dev)
2283 {
2284 	return (dev->devclass);
2285 }
2286 
2287 /**
2288  * @brief Return the name of the device's devclass or @c NULL if there
2289  * is none.
2290  */
2291 const char *
2292 device_get_name(device_t dev)
2293 {
2294 	if (dev != NULL && dev->devclass)
2295 		return (devclass_get_name(dev->devclass));
2296 	return (NULL);
2297 }
2298 
2299 /**
2300  * @brief Return a string containing the device's devclass name
2301  * followed by an ascii representation of the device's unit number
2302  * (e.g. @c "foo2").
2303  */
2304 const char *
2305 device_get_nameunit(device_t dev)
2306 {
2307 	return (dev->nameunit);
2308 }
2309 
2310 /**
2311  * @brief Return the device's unit number.
2312  */
2313 int
2314 device_get_unit(device_t dev)
2315 {
2316 	return (dev->unit);
2317 }
2318 
2319 /**
2320  * @brief Return the device's description string
2321  */
2322 const char *
2323 device_get_desc(device_t dev)
2324 {
2325 	return (dev->desc);
2326 }
2327 
2328 /**
2329  * @brief Return the device's flags
2330  */
2331 uint32_t
2332 device_get_flags(device_t dev)
2333 {
2334 	return (dev->devflags);
2335 }
2336 
2337 struct sysctl_ctx_list *
2338 device_get_sysctl_ctx(device_t dev)
2339 {
2340 	return (&dev->sysctl_ctx);
2341 }
2342 
2343 struct sysctl_oid *
2344 device_get_sysctl_tree(device_t dev)
2345 {
2346 	return (dev->sysctl_tree);
2347 }
2348 
2349 /**
2350  * @brief Print the name of the device followed by a colon and a space
2351  *
2352  * @returns the number of characters printed
2353  */
2354 int
2355 device_print_prettyname(device_t dev)
2356 {
2357 	const char *name = device_get_name(dev);
2358 
2359 	if (name == NULL)
2360 		return (printf("unknown: "));
2361 	return (printf("%s%d: ", name, device_get_unit(dev)));
2362 }
2363 
2364 /**
2365  * @brief Print the name of the device followed by a colon, a space
2366  * and the result of calling vprintf() with the value of @p fmt and
2367  * the following arguments.
2368  *
2369  * @returns the number of characters printed
2370  */
2371 int
2372 device_printf(device_t dev, const char * fmt, ...)
2373 {
2374 	va_list ap;
2375 	int retval;
2376 
2377 	retval = device_print_prettyname(dev);
2378 	va_start(ap, fmt);
2379 	retval += vprintf(fmt, ap);
2380 	va_end(ap);
2381 	return (retval);
2382 }
2383 
2384 /**
2385  * @internal
2386  */
2387 static void
2388 device_set_desc_internal(device_t dev, const char* desc, int copy)
2389 {
2390 	if (dev->desc && (dev->flags & DF_DESCMALLOCED)) {
2391 		free(dev->desc, M_BUS);
2392 		dev->flags &= ~DF_DESCMALLOCED;
2393 		dev->desc = NULL;
2394 	}
2395 
2396 	if (copy && desc) {
2397 		dev->desc = malloc(strlen(desc) + 1, M_BUS, M_NOWAIT);
2398 		if (dev->desc) {
2399 			strcpy(dev->desc, desc);
2400 			dev->flags |= DF_DESCMALLOCED;
2401 		}
2402 	} else {
2403 		/* Avoid a -Wcast-qual warning */
2404 		dev->desc = (char *)(uintptr_t) desc;
2405 	}
2406 
2407 	bus_data_generation_update();
2408 }
2409 
2410 /**
2411  * @brief Set the device's description
2412  *
2413  * The value of @c desc should be a string constant that will not
2414  * change (at least until the description is changed in a subsequent
2415  * call to device_set_desc() or device_set_desc_copy()).
2416  */
2417 void
2418 device_set_desc(device_t dev, const char* desc)
2419 {
2420 	device_set_desc_internal(dev, desc, FALSE);
2421 }
2422 
2423 /**
2424  * @brief Set the device's description
2425  *
2426  * The string pointed to by @c desc is copied. Use this function if
2427  * the device description is generated, (e.g. with sprintf()).
2428  */
2429 void
2430 device_set_desc_copy(device_t dev, const char* desc)
2431 {
2432 	device_set_desc_internal(dev, desc, TRUE);
2433 }
2434 
2435 /**
2436  * @brief Set the device's flags
2437  */
2438 void
2439 device_set_flags(device_t dev, uint32_t flags)
2440 {
2441 	dev->devflags = flags;
2442 }
2443 
2444 /**
2445  * @brief Return the device's softc field
2446  *
2447  * The softc is allocated and zeroed when a driver is attached, based
2448  * on the size field of the driver.
2449  */
2450 void *
2451 device_get_softc(device_t dev)
2452 {
2453 	return (dev->softc);
2454 }
2455 
2456 /**
2457  * @brief Set the device's softc field
2458  *
2459  * Most drivers do not need to use this since the softc is allocated
2460  * automatically when the driver is attached.
2461  */
2462 void
2463 device_set_softc(device_t dev, void *softc)
2464 {
2465 	if (dev->softc && !(dev->flags & DF_EXTERNALSOFTC))
2466 		free(dev->softc, M_BUS_SC);
2467 	dev->softc = softc;
2468 	if (dev->softc)
2469 		dev->flags |= DF_EXTERNALSOFTC;
2470 	else
2471 		dev->flags &= ~DF_EXTERNALSOFTC;
2472 }
2473 
2474 /**
2475  * @brief Free claimed softc
2476  *
2477  * Most drivers do not need to use this since the softc is freed
2478  * automatically when the driver is detached.
2479  */
2480 void
2481 device_free_softc(void *softc)
2482 {
2483 	free(softc, M_BUS_SC);
2484 }
2485 
2486 /**
2487  * @brief Claim softc
2488  *
2489  * This function can be used to let the driver free the automatically
2490  * allocated softc using "device_free_softc()". This function is
2491  * useful when the driver is refcounting the softc and the softc
2492  * cannot be freed when the "device_detach" method is called.
2493  */
2494 void
2495 device_claim_softc(device_t dev)
2496 {
2497 	if (dev->softc)
2498 		dev->flags |= DF_EXTERNALSOFTC;
2499 	else
2500 		dev->flags &= ~DF_EXTERNALSOFTC;
2501 }
2502 
2503 /**
2504  * @brief Get the device's ivars field
2505  *
2506  * The ivars field is used by the parent device to store per-device
2507  * state (e.g. the physical location of the device or a list of
2508  * resources).
2509  */
2510 void *
2511 device_get_ivars(device_t dev)
2512 {
2513 
2514 	KASSERT(dev != NULL, ("device_get_ivars(NULL, ...)"));
2515 	return (dev->ivars);
2516 }
2517 
2518 /**
2519  * @brief Set the device's ivars field
2520  */
2521 void
2522 device_set_ivars(device_t dev, void * ivars)
2523 {
2524 
2525 	KASSERT(dev != NULL, ("device_set_ivars(NULL, ...)"));
2526 	dev->ivars = ivars;
2527 }
2528 
2529 /**
2530  * @brief Return the device's state
2531  */
2532 device_state_t
2533 device_get_state(device_t dev)
2534 {
2535 	return (dev->state);
2536 }
2537 
2538 /**
2539  * @brief Set the DF_ENABLED flag for the device
2540  */
2541 void
2542 device_enable(device_t dev)
2543 {
2544 	dev->flags |= DF_ENABLED;
2545 }
2546 
2547 /**
2548  * @brief Clear the DF_ENABLED flag for the device
2549  */
2550 void
2551 device_disable(device_t dev)
2552 {
2553 	dev->flags &= ~DF_ENABLED;
2554 }
2555 
2556 /**
2557  * @brief Increment the busy counter for the device
2558  */
2559 void
2560 device_busy(device_t dev)
2561 {
2562 	if (dev->state < DS_ATTACHING)
2563 		panic("device_busy: called for unattached device");
2564 	if (dev->busy == 0 && dev->parent)
2565 		device_busy(dev->parent);
2566 	dev->busy++;
2567 	if (dev->state == DS_ATTACHED)
2568 		dev->state = DS_BUSY;
2569 }
2570 
2571 /**
2572  * @brief Decrement the busy counter for the device
2573  */
2574 void
2575 device_unbusy(device_t dev)
2576 {
2577 	if (dev->busy != 0 && dev->state != DS_BUSY &&
2578 	    dev->state != DS_ATTACHING)
2579 		panic("device_unbusy: called for non-busy device %s",
2580 		    device_get_nameunit(dev));
2581 	dev->busy--;
2582 	if (dev->busy == 0) {
2583 		if (dev->parent)
2584 			device_unbusy(dev->parent);
2585 		if (dev->state == DS_BUSY)
2586 			dev->state = DS_ATTACHED;
2587 	}
2588 }
2589 
2590 /**
2591  * @brief Set the DF_QUIET flag for the device
2592  */
2593 void
2594 device_quiet(device_t dev)
2595 {
2596 	dev->flags |= DF_QUIET;
2597 }
2598 
2599 /**
2600  * @brief Clear the DF_QUIET flag for the device
2601  */
2602 void
2603 device_verbose(device_t dev)
2604 {
2605 	dev->flags &= ~DF_QUIET;
2606 }
2607 
2608 /**
2609  * @brief Return non-zero if the DF_QUIET flag is set on the device
2610  */
2611 int
2612 device_is_quiet(device_t dev)
2613 {
2614 	return ((dev->flags & DF_QUIET) != 0);
2615 }
2616 
2617 /**
2618  * @brief Return non-zero if the DF_ENABLED flag is set on the device
2619  */
2620 int
2621 device_is_enabled(device_t dev)
2622 {
2623 	return ((dev->flags & DF_ENABLED) != 0);
2624 }
2625 
2626 /**
2627  * @brief Return non-zero if the device was successfully probed
2628  */
2629 int
2630 device_is_alive(device_t dev)
2631 {
2632 	return (dev->state >= DS_ALIVE);
2633 }
2634 
2635 /**
2636  * @brief Return non-zero if the device currently has a driver
2637  * attached to it
2638  */
2639 int
2640 device_is_attached(device_t dev)
2641 {
2642 	return (dev->state >= DS_ATTACHED);
2643 }
2644 
2645 /**
2646  * @brief Return non-zero if the device is currently suspended.
2647  */
2648 int
2649 device_is_suspended(device_t dev)
2650 {
2651 	return ((dev->flags & DF_SUSPENDED) != 0);
2652 }
2653 
2654 /**
2655  * @brief Set the devclass of a device
2656  * @see devclass_add_device().
2657  */
2658 int
2659 device_set_devclass(device_t dev, const char *classname)
2660 {
2661 	devclass_t dc;
2662 	int error;
2663 
2664 	if (!classname) {
2665 		if (dev->devclass)
2666 			devclass_delete_device(dev->devclass, dev);
2667 		return (0);
2668 	}
2669 
2670 	if (dev->devclass) {
2671 		printf("device_set_devclass: device class already set\n");
2672 		return (EINVAL);
2673 	}
2674 
2675 	dc = devclass_find_internal(classname, NULL, TRUE);
2676 	if (!dc)
2677 		return (ENOMEM);
2678 
2679 	error = devclass_add_device(dc, dev);
2680 
2681 	bus_data_generation_update();
2682 	return (error);
2683 }
2684 
2685 /**
2686  * @brief Set the devclass of a device and mark the devclass fixed.
2687  * @see device_set_devclass()
2688  */
2689 int
2690 device_set_devclass_fixed(device_t dev, const char *classname)
2691 {
2692 	int error;
2693 
2694 	if (classname == NULL)
2695 		return (EINVAL);
2696 
2697 	error = device_set_devclass(dev, classname);
2698 	if (error)
2699 		return (error);
2700 	dev->flags |= DF_FIXEDCLASS;
2701 	return (0);
2702 }
2703 
2704 /**
2705  * @brief Set the driver of a device
2706  *
2707  * @retval 0		success
2708  * @retval EBUSY	the device already has a driver attached
2709  * @retval ENOMEM	a memory allocation failure occurred
2710  */
2711 int
2712 device_set_driver(device_t dev, driver_t *driver)
2713 {
2714 	if (dev->state >= DS_ATTACHED)
2715 		return (EBUSY);
2716 
2717 	if (dev->driver == driver)
2718 		return (0);
2719 
2720 	if (dev->softc && !(dev->flags & DF_EXTERNALSOFTC)) {
2721 		free(dev->softc, M_BUS_SC);
2722 		dev->softc = NULL;
2723 	}
2724 	device_set_desc(dev, NULL);
2725 	kobj_delete((kobj_t) dev, NULL);
2726 	dev->driver = driver;
2727 	if (driver) {
2728 		kobj_init((kobj_t) dev, (kobj_class_t) driver);
2729 		if (!(dev->flags & DF_EXTERNALSOFTC) && driver->size > 0) {
2730 			dev->softc = malloc(driver->size, M_BUS_SC,
2731 			    M_NOWAIT | M_ZERO);
2732 			if (!dev->softc) {
2733 				kobj_delete((kobj_t) dev, NULL);
2734 				kobj_init((kobj_t) dev, &null_class);
2735 				dev->driver = NULL;
2736 				return (ENOMEM);
2737 			}
2738 		}
2739 	} else {
2740 		kobj_init((kobj_t) dev, &null_class);
2741 	}
2742 
2743 	bus_data_generation_update();
2744 	return (0);
2745 }
2746 
2747 /**
2748  * @brief Probe a device, and return this status.
2749  *
2750  * This function is the core of the device autoconfiguration
2751  * system. Its purpose is to select a suitable driver for a device and
2752  * then call that driver to initialise the hardware appropriately. The
2753  * driver is selected by calling the DEVICE_PROBE() method of a set of
2754  * candidate drivers and then choosing the driver which returned the
2755  * best value. This driver is then attached to the device using
2756  * device_attach().
2757  *
2758  * The set of suitable drivers is taken from the list of drivers in
2759  * the parent device's devclass. If the device was originally created
2760  * with a specific class name (see device_add_child()), only drivers
2761  * with that name are probed, otherwise all drivers in the devclass
2762  * are probed. If no drivers return successful probe values in the
2763  * parent devclass, the search continues in the parent of that
2764  * devclass (see devclass_get_parent()) if any.
2765  *
2766  * @param dev		the device to initialise
2767  *
2768  * @retval 0		success
2769  * @retval ENXIO	no driver was found
2770  * @retval ENOMEM	memory allocation failure
2771  * @retval non-zero	some other unix error code
2772  * @retval -1		Device already attached
2773  */
2774 int
2775 device_probe(device_t dev)
2776 {
2777 	int error;
2778 
2779 	GIANT_REQUIRED;
2780 
2781 	if (dev->state >= DS_ALIVE && (dev->flags & DF_REBID) == 0)
2782 		return (-1);
2783 
2784 	if (!(dev->flags & DF_ENABLED)) {
2785 		if (bootverbose && device_get_name(dev) != NULL) {
2786 			device_print_prettyname(dev);
2787 			printf("not probed (disabled)\n");
2788 		}
2789 		return (-1);
2790 	}
2791 	if ((error = device_probe_child(dev->parent, dev)) != 0) {
2792 		if (bus_current_pass == BUS_PASS_DEFAULT &&
2793 		    !(dev->flags & DF_DONENOMATCH)) {
2794 			BUS_PROBE_NOMATCH(dev->parent, dev);
2795 			devnomatch(dev);
2796 			dev->flags |= DF_DONENOMATCH;
2797 		}
2798 		return (error);
2799 	}
2800 	return (0);
2801 }
2802 
2803 /**
2804  * @brief Probe a device and attach a driver if possible
2805  *
2806  * calls device_probe() and attaches if that was successful.
2807  */
2808 int
2809 device_probe_and_attach(device_t dev)
2810 {
2811 	int error;
2812 
2813 	GIANT_REQUIRED;
2814 
2815 	error = device_probe(dev);
2816 	if (error == -1)
2817 		return (0);
2818 	else if (error != 0)
2819 		return (error);
2820 
2821 	CURVNET_SET_QUIET(vnet0);
2822 	error = device_attach(dev);
2823 	CURVNET_RESTORE();
2824 	return error;
2825 }
2826 
2827 /**
2828  * @brief Attach a device driver to a device
2829  *
2830  * This function is a wrapper around the DEVICE_ATTACH() driver
2831  * method. In addition to calling DEVICE_ATTACH(), it initialises the
2832  * device's sysctl tree, optionally prints a description of the device
2833  * and queues a notification event for user-based device management
2834  * services.
2835  *
2836  * Normally this function is only called internally from
2837  * device_probe_and_attach().
2838  *
2839  * @param dev		the device to initialise
2840  *
2841  * @retval 0		success
2842  * @retval ENXIO	no driver was found
2843  * @retval ENOMEM	memory allocation failure
2844  * @retval non-zero	some other unix error code
2845  */
2846 int
2847 device_attach(device_t dev)
2848 {
2849 	uint64_t attachtime;
2850 	int error;
2851 
2852 	if (resource_disabled(dev->driver->name, dev->unit)) {
2853 		device_disable(dev);
2854 		if (bootverbose)
2855 			 device_printf(dev, "disabled via hints entry\n");
2856 		return (ENXIO);
2857 	}
2858 
2859 	device_sysctl_init(dev);
2860 	if (!device_is_quiet(dev))
2861 		device_print_child(dev->parent, dev);
2862 	attachtime = get_cyclecount();
2863 	dev->state = DS_ATTACHING;
2864 	if ((error = DEVICE_ATTACH(dev)) != 0) {
2865 		printf("device_attach: %s%d attach returned %d\n",
2866 		    dev->driver->name, dev->unit, error);
2867 		if (!(dev->flags & DF_FIXEDCLASS))
2868 			devclass_delete_device(dev->devclass, dev);
2869 		(void)device_set_driver(dev, NULL);
2870 		device_sysctl_fini(dev);
2871 		KASSERT(dev->busy == 0, ("attach failed but busy"));
2872 		dev->state = DS_NOTPRESENT;
2873 		return (error);
2874 	}
2875 	attachtime = get_cyclecount() - attachtime;
2876 	/*
2877 	 * 4 bits per device is a reasonable value for desktop and server
2878 	 * hardware with good get_cyclecount() implementations, but may
2879 	 * need to be adjusted on other platforms.
2880 	 */
2881 #ifdef RANDOM_DEBUG
2882 	printf("random: %s(): feeding %d bit(s) of entropy from %s%d\n",
2883 	    __func__, 4, dev->driver->name, dev->unit);
2884 #endif
2885 	random_harvest(&attachtime, sizeof(attachtime), 4, RANDOM_ATTACH);
2886 	device_sysctl_update(dev);
2887 	if (dev->busy)
2888 		dev->state = DS_BUSY;
2889 	else
2890 		dev->state = DS_ATTACHED;
2891 	dev->flags &= ~DF_DONENOMATCH;
2892 	devadded(dev);
2893 	return (0);
2894 }
2895 
2896 /**
2897  * @brief Detach a driver from a device
2898  *
2899  * This function is a wrapper around the DEVICE_DETACH() driver
2900  * method. If the call to DEVICE_DETACH() succeeds, it calls
2901  * BUS_CHILD_DETACHED() for the parent of @p dev, queues a
2902  * notification event for user-based device management services and
2903  * cleans up the device's sysctl tree.
2904  *
2905  * @param dev		the device to un-initialise
2906  *
2907  * @retval 0		success
2908  * @retval ENXIO	no driver was found
2909  * @retval ENOMEM	memory allocation failure
2910  * @retval non-zero	some other unix error code
2911  */
2912 int
2913 device_detach(device_t dev)
2914 {
2915 	int error;
2916 
2917 	GIANT_REQUIRED;
2918 
2919 	PDEBUG(("%s", DEVICENAME(dev)));
2920 	if (dev->state == DS_BUSY)
2921 		return (EBUSY);
2922 	if (dev->state != DS_ATTACHED)
2923 		return (0);
2924 
2925 	if ((error = DEVICE_DETACH(dev)) != 0)
2926 		return (error);
2927 	devremoved(dev);
2928 	if (!device_is_quiet(dev))
2929 		device_printf(dev, "detached\n");
2930 	if (dev->parent)
2931 		BUS_CHILD_DETACHED(dev->parent, dev);
2932 
2933 	if (!(dev->flags & DF_FIXEDCLASS))
2934 		devclass_delete_device(dev->devclass, dev);
2935 
2936 	dev->state = DS_NOTPRESENT;
2937 	(void)device_set_driver(dev, NULL);
2938 	device_sysctl_fini(dev);
2939 
2940 	return (0);
2941 }
2942 
2943 /**
2944  * @brief Tells a driver to quiesce itself.
2945  *
2946  * This function is a wrapper around the DEVICE_QUIESCE() driver
2947  * method. If the call to DEVICE_QUIESCE() succeeds.
2948  *
2949  * @param dev		the device to quiesce
2950  *
2951  * @retval 0		success
2952  * @retval ENXIO	no driver was found
2953  * @retval ENOMEM	memory allocation failure
2954  * @retval non-zero	some other unix error code
2955  */
2956 int
2957 device_quiesce(device_t dev)
2958 {
2959 
2960 	PDEBUG(("%s", DEVICENAME(dev)));
2961 	if (dev->state == DS_BUSY)
2962 		return (EBUSY);
2963 	if (dev->state != DS_ATTACHED)
2964 		return (0);
2965 
2966 	return (DEVICE_QUIESCE(dev));
2967 }
2968 
2969 /**
2970  * @brief Notify a device of system shutdown
2971  *
2972  * This function calls the DEVICE_SHUTDOWN() driver method if the
2973  * device currently has an attached driver.
2974  *
2975  * @returns the value returned by DEVICE_SHUTDOWN()
2976  */
2977 int
2978 device_shutdown(device_t dev)
2979 {
2980 	if (dev->state < DS_ATTACHED)
2981 		return (0);
2982 	return (DEVICE_SHUTDOWN(dev));
2983 }
2984 
2985 /**
2986  * @brief Set the unit number of a device
2987  *
2988  * This function can be used to override the unit number used for a
2989  * device (e.g. to wire a device to a pre-configured unit number).
2990  */
2991 int
2992 device_set_unit(device_t dev, int unit)
2993 {
2994 	devclass_t dc;
2995 	int err;
2996 
2997 	dc = device_get_devclass(dev);
2998 	if (unit < dc->maxunit && dc->devices[unit])
2999 		return (EBUSY);
3000 	err = devclass_delete_device(dc, dev);
3001 	if (err)
3002 		return (err);
3003 	dev->unit = unit;
3004 	err = devclass_add_device(dc, dev);
3005 	if (err)
3006 		return (err);
3007 
3008 	bus_data_generation_update();
3009 	return (0);
3010 }
3011 
3012 /*======================================*/
3013 /*
3014  * Some useful method implementations to make life easier for bus drivers.
3015  */
3016 
3017 /**
3018  * @brief Initialise a resource list.
3019  *
3020  * @param rl		the resource list to initialise
3021  */
3022 void
3023 resource_list_init(struct resource_list *rl)
3024 {
3025 	STAILQ_INIT(rl);
3026 }
3027 
3028 /**
3029  * @brief Reclaim memory used by a resource list.
3030  *
3031  * This function frees the memory for all resource entries on the list
3032  * (if any).
3033  *
3034  * @param rl		the resource list to free
3035  */
3036 void
3037 resource_list_free(struct resource_list *rl)
3038 {
3039 	struct resource_list_entry *rle;
3040 
3041 	while ((rle = STAILQ_FIRST(rl)) != NULL) {
3042 		if (rle->res)
3043 			panic("resource_list_free: resource entry is busy");
3044 		STAILQ_REMOVE_HEAD(rl, link);
3045 		free(rle, M_BUS);
3046 	}
3047 }
3048 
3049 /**
3050  * @brief Add a resource entry.
3051  *
3052  * This function adds a resource entry using the given @p type, @p
3053  * start, @p end and @p count values. A rid value is chosen by
3054  * searching sequentially for the first unused rid starting at zero.
3055  *
3056  * @param rl		the resource list to edit
3057  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
3058  * @param start		the start address of the resource
3059  * @param end		the end address of the resource
3060  * @param count		XXX end-start+1
3061  */
3062 int
3063 resource_list_add_next(struct resource_list *rl, int type, u_long start,
3064     u_long end, u_long count)
3065 {
3066 	int rid;
3067 
3068 	rid = 0;
3069 	while (resource_list_find(rl, type, rid) != NULL)
3070 		rid++;
3071 	resource_list_add(rl, type, rid, start, end, count);
3072 	return (rid);
3073 }
3074 
3075 /**
3076  * @brief Add or modify a resource entry.
3077  *
3078  * If an existing entry exists with the same type and rid, it will be
3079  * modified using the given values of @p start, @p end and @p
3080  * count. If no entry exists, a new one will be created using the
3081  * given values.  The resource list entry that matches is then returned.
3082  *
3083  * @param rl		the resource list to edit
3084  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
3085  * @param rid		the resource identifier
3086  * @param start		the start address of the resource
3087  * @param end		the end address of the resource
3088  * @param count		XXX end-start+1
3089  */
3090 struct resource_list_entry *
3091 resource_list_add(struct resource_list *rl, int type, int rid,
3092     u_long start, u_long end, u_long count)
3093 {
3094 	struct resource_list_entry *rle;
3095 
3096 	rle = resource_list_find(rl, type, rid);
3097 	if (!rle) {
3098 		rle = malloc(sizeof(struct resource_list_entry), M_BUS,
3099 		    M_NOWAIT);
3100 		if (!rle)
3101 			panic("resource_list_add: can't record entry");
3102 		STAILQ_INSERT_TAIL(rl, rle, link);
3103 		rle->type = type;
3104 		rle->rid = rid;
3105 		rle->res = NULL;
3106 		rle->flags = 0;
3107 	}
3108 
3109 	if (rle->res)
3110 		panic("resource_list_add: resource entry is busy");
3111 
3112 	rle->start = start;
3113 	rle->end = end;
3114 	rle->count = count;
3115 	return (rle);
3116 }
3117 
3118 /**
3119  * @brief Determine if a resource entry is busy.
3120  *
3121  * Returns true if a resource entry is busy meaning that it has an
3122  * associated resource that is not an unallocated "reserved" resource.
3123  *
3124  * @param rl		the resource list to search
3125  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
3126  * @param rid		the resource identifier
3127  *
3128  * @returns Non-zero if the entry is busy, zero otherwise.
3129  */
3130 int
3131 resource_list_busy(struct resource_list *rl, int type, int rid)
3132 {
3133 	struct resource_list_entry *rle;
3134 
3135 	rle = resource_list_find(rl, type, rid);
3136 	if (rle == NULL || rle->res == NULL)
3137 		return (0);
3138 	if ((rle->flags & (RLE_RESERVED | RLE_ALLOCATED)) == RLE_RESERVED) {
3139 		KASSERT(!(rman_get_flags(rle->res) & RF_ACTIVE),
3140 		    ("reserved resource is active"));
3141 		return (0);
3142 	}
3143 	return (1);
3144 }
3145 
3146 /**
3147  * @brief Determine if a resource entry is reserved.
3148  *
3149  * Returns true if a resource entry is reserved meaning that it has an
3150  * associated "reserved" resource.  The resource can either be
3151  * allocated or unallocated.
3152  *
3153  * @param rl		the resource list to search
3154  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
3155  * @param rid		the resource identifier
3156  *
3157  * @returns Non-zero if the entry is reserved, zero otherwise.
3158  */
3159 int
3160 resource_list_reserved(struct resource_list *rl, int type, int rid)
3161 {
3162 	struct resource_list_entry *rle;
3163 
3164 	rle = resource_list_find(rl, type, rid);
3165 	if (rle != NULL && rle->flags & RLE_RESERVED)
3166 		return (1);
3167 	return (0);
3168 }
3169 
3170 /**
3171  * @brief Find a resource entry by type and rid.
3172  *
3173  * @param rl		the resource list to search
3174  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
3175  * @param rid		the resource identifier
3176  *
3177  * @returns the resource entry pointer or NULL if there is no such
3178  * entry.
3179  */
3180 struct resource_list_entry *
3181 resource_list_find(struct resource_list *rl, int type, int rid)
3182 {
3183 	struct resource_list_entry *rle;
3184 
3185 	STAILQ_FOREACH(rle, rl, link) {
3186 		if (rle->type == type && rle->rid == rid)
3187 			return (rle);
3188 	}
3189 	return (NULL);
3190 }
3191 
3192 /**
3193  * @brief Delete a resource entry.
3194  *
3195  * @param rl		the resource list to edit
3196  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
3197  * @param rid		the resource identifier
3198  */
3199 void
3200 resource_list_delete(struct resource_list *rl, int type, int rid)
3201 {
3202 	struct resource_list_entry *rle = resource_list_find(rl, type, rid);
3203 
3204 	if (rle) {
3205 		if (rle->res != NULL)
3206 			panic("resource_list_delete: resource has not been released");
3207 		STAILQ_REMOVE(rl, rle, resource_list_entry, link);
3208 		free(rle, M_BUS);
3209 	}
3210 }
3211 
3212 /**
3213  * @brief Allocate a reserved resource
3214  *
3215  * This can be used by busses to force the allocation of resources
3216  * that are always active in the system even if they are not allocated
3217  * by a driver (e.g. PCI BARs).  This function is usually called when
3218  * adding a new child to the bus.  The resource is allocated from the
3219  * parent bus when it is reserved.  The resource list entry is marked
3220  * with RLE_RESERVED to note that it is a reserved resource.
3221  *
3222  * Subsequent attempts to allocate the resource with
3223  * resource_list_alloc() will succeed the first time and will set
3224  * RLE_ALLOCATED to note that it has been allocated.  When a reserved
3225  * resource that has been allocated is released with
3226  * resource_list_release() the resource RLE_ALLOCATED is cleared, but
3227  * the actual resource remains allocated.  The resource can be released to
3228  * the parent bus by calling resource_list_unreserve().
3229  *
3230  * @param rl		the resource list to allocate from
3231  * @param bus		the parent device of @p child
3232  * @param child		the device for which the resource is being reserved
3233  * @param type		the type of resource to allocate
3234  * @param rid		a pointer to the resource identifier
3235  * @param start		hint at the start of the resource range - pass
3236  *			@c 0UL for any start address
3237  * @param end		hint at the end of the resource range - pass
3238  *			@c ~0UL for any end address
3239  * @param count		hint at the size of range required - pass @c 1
3240  *			for any size
3241  * @param flags		any extra flags to control the resource
3242  *			allocation - see @c RF_XXX flags in
3243  *			<sys/rman.h> for details
3244  *
3245  * @returns		the resource which was allocated or @c NULL if no
3246  *			resource could be allocated
3247  */
3248 struct resource *
3249 resource_list_reserve(struct resource_list *rl, device_t bus, device_t child,
3250     int type, int *rid, u_long start, u_long end, u_long count, u_int flags)
3251 {
3252 	struct resource_list_entry *rle = NULL;
3253 	int passthrough = (device_get_parent(child) != bus);
3254 	struct resource *r;
3255 
3256 	if (passthrough)
3257 		panic(
3258     "resource_list_reserve() should only be called for direct children");
3259 	if (flags & RF_ACTIVE)
3260 		panic(
3261     "resource_list_reserve() should only reserve inactive resources");
3262 
3263 	r = resource_list_alloc(rl, bus, child, type, rid, start, end, count,
3264 	    flags);
3265 	if (r != NULL) {
3266 		rle = resource_list_find(rl, type, *rid);
3267 		rle->flags |= RLE_RESERVED;
3268 	}
3269 	return (r);
3270 }
3271 
3272 /**
3273  * @brief Helper function for implementing BUS_ALLOC_RESOURCE()
3274  *
3275  * Implement BUS_ALLOC_RESOURCE() by looking up a resource from the list
3276  * and passing the allocation up to the parent of @p bus. This assumes
3277  * that the first entry of @c device_get_ivars(child) is a struct
3278  * resource_list. This also handles 'passthrough' allocations where a
3279  * child is a remote descendant of bus by passing the allocation up to
3280  * the parent of bus.
3281  *
3282  * Typically, a bus driver would store a list of child resources
3283  * somewhere in the child device's ivars (see device_get_ivars()) and
3284  * its implementation of BUS_ALLOC_RESOURCE() would find that list and
3285  * then call resource_list_alloc() to perform the allocation.
3286  *
3287  * @param rl		the resource list to allocate from
3288  * @param bus		the parent device of @p child
3289  * @param child		the device which is requesting an allocation
3290  * @param type		the type of resource to allocate
3291  * @param rid		a pointer to the resource identifier
3292  * @param start		hint at the start of the resource range - pass
3293  *			@c 0UL for any start address
3294  * @param end		hint at the end of the resource range - pass
3295  *			@c ~0UL for any end address
3296  * @param count		hint at the size of range required - pass @c 1
3297  *			for any size
3298  * @param flags		any extra flags to control the resource
3299  *			allocation - see @c RF_XXX flags in
3300  *			<sys/rman.h> for details
3301  *
3302  * @returns		the resource which was allocated or @c NULL if no
3303  *			resource could be allocated
3304  */
3305 struct resource *
3306 resource_list_alloc(struct resource_list *rl, device_t bus, device_t child,
3307     int type, int *rid, u_long start, u_long end, u_long count, u_int flags)
3308 {
3309 	struct resource_list_entry *rle = NULL;
3310 	int passthrough = (device_get_parent(child) != bus);
3311 	int isdefault = (start == 0UL && end == ~0UL);
3312 
3313 	if (passthrough) {
3314 		return (BUS_ALLOC_RESOURCE(device_get_parent(bus), child,
3315 		    type, rid, start, end, count, flags));
3316 	}
3317 
3318 	rle = resource_list_find(rl, type, *rid);
3319 
3320 	if (!rle)
3321 		return (NULL);		/* no resource of that type/rid */
3322 
3323 	if (rle->res) {
3324 		if (rle->flags & RLE_RESERVED) {
3325 			if (rle->flags & RLE_ALLOCATED)
3326 				return (NULL);
3327 			if ((flags & RF_ACTIVE) &&
3328 			    bus_activate_resource(child, type, *rid,
3329 			    rle->res) != 0)
3330 				return (NULL);
3331 			rle->flags |= RLE_ALLOCATED;
3332 			return (rle->res);
3333 		}
3334 		device_printf(bus,
3335 		    "resource entry %#x type %d for child %s is busy\n", *rid,
3336 		    type, device_get_nameunit(child));
3337 		return (NULL);
3338 	}
3339 
3340 	if (isdefault) {
3341 		start = rle->start;
3342 		count = ulmax(count, rle->count);
3343 		end = ulmax(rle->end, start + count - 1);
3344 	}
3345 
3346 	rle->res = BUS_ALLOC_RESOURCE(device_get_parent(bus), child,
3347 	    type, rid, start, end, count, flags);
3348 
3349 	/*
3350 	 * Record the new range.
3351 	 */
3352 	if (rle->res) {
3353 		rle->start = rman_get_start(rle->res);
3354 		rle->end = rman_get_end(rle->res);
3355 		rle->count = count;
3356 	}
3357 
3358 	return (rle->res);
3359 }
3360 
3361 /**
3362  * @brief Helper function for implementing BUS_RELEASE_RESOURCE()
3363  *
3364  * Implement BUS_RELEASE_RESOURCE() using a resource list. Normally
3365  * used with resource_list_alloc().
3366  *
3367  * @param rl		the resource list which was allocated from
3368  * @param bus		the parent device of @p child
3369  * @param child		the device which is requesting a release
3370  * @param type		the type of resource to release
3371  * @param rid		the resource identifier
3372  * @param res		the resource to release
3373  *
3374  * @retval 0		success
3375  * @retval non-zero	a standard unix error code indicating what
3376  *			error condition prevented the operation
3377  */
3378 int
3379 resource_list_release(struct resource_list *rl, device_t bus, device_t child,
3380     int type, int rid, struct resource *res)
3381 {
3382 	struct resource_list_entry *rle = NULL;
3383 	int passthrough = (device_get_parent(child) != bus);
3384 	int error;
3385 
3386 	if (passthrough) {
3387 		return (BUS_RELEASE_RESOURCE(device_get_parent(bus), child,
3388 		    type, rid, res));
3389 	}
3390 
3391 	rle = resource_list_find(rl, type, rid);
3392 
3393 	if (!rle)
3394 		panic("resource_list_release: can't find resource");
3395 	if (!rle->res)
3396 		panic("resource_list_release: resource entry is not busy");
3397 	if (rle->flags & RLE_RESERVED) {
3398 		if (rle->flags & RLE_ALLOCATED) {
3399 			if (rman_get_flags(res) & RF_ACTIVE) {
3400 				error = bus_deactivate_resource(child, type,
3401 				    rid, res);
3402 				if (error)
3403 					return (error);
3404 			}
3405 			rle->flags &= ~RLE_ALLOCATED;
3406 			return (0);
3407 		}
3408 		return (EINVAL);
3409 	}
3410 
3411 	error = BUS_RELEASE_RESOURCE(device_get_parent(bus), child,
3412 	    type, rid, res);
3413 	if (error)
3414 		return (error);
3415 
3416 	rle->res = NULL;
3417 	return (0);
3418 }
3419 
3420 /**
3421  * @brief Release all active resources of a given type
3422  *
3423  * Release all active resources of a specified type.  This is intended
3424  * to be used to cleanup resources leaked by a driver after detach or
3425  * a failed attach.
3426  *
3427  * @param rl		the resource list which was allocated from
3428  * @param bus		the parent device of @p child
3429  * @param child		the device whose active resources are being released
3430  * @param type		the type of resources to release
3431  *
3432  * @retval 0		success
3433  * @retval EBUSY	at least one resource was active
3434  */
3435 int
3436 resource_list_release_active(struct resource_list *rl, device_t bus,
3437     device_t child, int type)
3438 {
3439 	struct resource_list_entry *rle;
3440 	int error, retval;
3441 
3442 	retval = 0;
3443 	STAILQ_FOREACH(rle, rl, link) {
3444 		if (rle->type != type)
3445 			continue;
3446 		if (rle->res == NULL)
3447 			continue;
3448 		if ((rle->flags & (RLE_RESERVED | RLE_ALLOCATED)) ==
3449 		    RLE_RESERVED)
3450 			continue;
3451 		retval = EBUSY;
3452 		error = resource_list_release(rl, bus, child, type,
3453 		    rman_get_rid(rle->res), rle->res);
3454 		if (error != 0)
3455 			device_printf(bus,
3456 			    "Failed to release active resource: %d\n", error);
3457 	}
3458 	return (retval);
3459 }
3460 
3461 
3462 /**
3463  * @brief Fully release a reserved resource
3464  *
3465  * Fully releases a resource reserved via resource_list_reserve().
3466  *
3467  * @param rl		the resource list which was allocated from
3468  * @param bus		the parent device of @p child
3469  * @param child		the device whose reserved resource is being released
3470  * @param type		the type of resource to release
3471  * @param rid		the resource identifier
3472  * @param res		the resource to release
3473  *
3474  * @retval 0		success
3475  * @retval non-zero	a standard unix error code indicating what
3476  *			error condition prevented the operation
3477  */
3478 int
3479 resource_list_unreserve(struct resource_list *rl, device_t bus, device_t child,
3480     int type, int rid)
3481 {
3482 	struct resource_list_entry *rle = NULL;
3483 	int passthrough = (device_get_parent(child) != bus);
3484 
3485 	if (passthrough)
3486 		panic(
3487     "resource_list_unreserve() should only be called for direct children");
3488 
3489 	rle = resource_list_find(rl, type, rid);
3490 
3491 	if (!rle)
3492 		panic("resource_list_unreserve: can't find resource");
3493 	if (!(rle->flags & RLE_RESERVED))
3494 		return (EINVAL);
3495 	if (rle->flags & RLE_ALLOCATED)
3496 		return (EBUSY);
3497 	rle->flags &= ~RLE_RESERVED;
3498 	return (resource_list_release(rl, bus, child, type, rid, rle->res));
3499 }
3500 
3501 /**
3502  * @brief Print a description of resources in a resource list
3503  *
3504  * Print all resources of a specified type, for use in BUS_PRINT_CHILD().
3505  * The name is printed if at least one resource of the given type is available.
3506  * The format is used to print resource start and end.
3507  *
3508  * @param rl		the resource list to print
3509  * @param name		the name of @p type, e.g. @c "memory"
3510  * @param type		type type of resource entry to print
3511  * @param format	printf(9) format string to print resource
3512  *			start and end values
3513  *
3514  * @returns		the number of characters printed
3515  */
3516 int
3517 resource_list_print_type(struct resource_list *rl, const char *name, int type,
3518     const char *format)
3519 {
3520 	struct resource_list_entry *rle;
3521 	int printed, retval;
3522 
3523 	printed = 0;
3524 	retval = 0;
3525 	/* Yes, this is kinda cheating */
3526 	STAILQ_FOREACH(rle, rl, link) {
3527 		if (rle->type == type) {
3528 			if (printed == 0)
3529 				retval += printf(" %s ", name);
3530 			else
3531 				retval += printf(",");
3532 			printed++;
3533 			retval += printf(format, rle->start);
3534 			if (rle->count > 1) {
3535 				retval += printf("-");
3536 				retval += printf(format, rle->start +
3537 						 rle->count - 1);
3538 			}
3539 		}
3540 	}
3541 	return (retval);
3542 }
3543 
3544 /**
3545  * @brief Releases all the resources in a list.
3546  *
3547  * @param rl		The resource list to purge.
3548  *
3549  * @returns		nothing
3550  */
3551 void
3552 resource_list_purge(struct resource_list *rl)
3553 {
3554 	struct resource_list_entry *rle;
3555 
3556 	while ((rle = STAILQ_FIRST(rl)) != NULL) {
3557 		if (rle->res)
3558 			bus_release_resource(rman_get_device(rle->res),
3559 			    rle->type, rle->rid, rle->res);
3560 		STAILQ_REMOVE_HEAD(rl, link);
3561 		free(rle, M_BUS);
3562 	}
3563 }
3564 
3565 device_t
3566 bus_generic_add_child(device_t dev, u_int order, const char *name, int unit)
3567 {
3568 
3569 	return (device_add_child_ordered(dev, order, name, unit));
3570 }
3571 
3572 /**
3573  * @brief Helper function for implementing DEVICE_PROBE()
3574  *
3575  * This function can be used to help implement the DEVICE_PROBE() for
3576  * a bus (i.e. a device which has other devices attached to it). It
3577  * calls the DEVICE_IDENTIFY() method of each driver in the device's
3578  * devclass.
3579  */
3580 int
3581 bus_generic_probe(device_t dev)
3582 {
3583 	devclass_t dc = dev->devclass;
3584 	driverlink_t dl;
3585 
3586 	TAILQ_FOREACH(dl, &dc->drivers, link) {
3587 		/*
3588 		 * If this driver's pass is too high, then ignore it.
3589 		 * For most drivers in the default pass, this will
3590 		 * never be true.  For early-pass drivers they will
3591 		 * only call the identify routines of eligible drivers
3592 		 * when this routine is called.  Drivers for later
3593 		 * passes should have their identify routines called
3594 		 * on early-pass busses during BUS_NEW_PASS().
3595 		 */
3596 		if (dl->pass > bus_current_pass)
3597 			continue;
3598 		DEVICE_IDENTIFY(dl->driver, dev);
3599 	}
3600 
3601 	return (0);
3602 }
3603 
3604 /**
3605  * @brief Helper function for implementing DEVICE_ATTACH()
3606  *
3607  * This function can be used to help implement the DEVICE_ATTACH() for
3608  * a bus. It calls device_probe_and_attach() for each of the device's
3609  * children.
3610  */
3611 int
3612 bus_generic_attach(device_t dev)
3613 {
3614 	device_t child;
3615 
3616 	TAILQ_FOREACH(child, &dev->children, link) {
3617 		device_probe_and_attach(child);
3618 	}
3619 
3620 	return (0);
3621 }
3622 
3623 /**
3624  * @brief Helper function for implementing DEVICE_DETACH()
3625  *
3626  * This function can be used to help implement the DEVICE_DETACH() for
3627  * a bus. It calls device_detach() for each of the device's
3628  * children.
3629  */
3630 int
3631 bus_generic_detach(device_t dev)
3632 {
3633 	device_t child;
3634 	int error;
3635 
3636 	if (dev->state != DS_ATTACHED)
3637 		return (EBUSY);
3638 
3639 	TAILQ_FOREACH(child, &dev->children, link) {
3640 		if ((error = device_detach(child)) != 0)
3641 			return (error);
3642 	}
3643 
3644 	return (0);
3645 }
3646 
3647 /**
3648  * @brief Helper function for implementing DEVICE_SHUTDOWN()
3649  *
3650  * This function can be used to help implement the DEVICE_SHUTDOWN()
3651  * for a bus. It calls device_shutdown() for each of the device's
3652  * children.
3653  */
3654 int
3655 bus_generic_shutdown(device_t dev)
3656 {
3657 	device_t child;
3658 
3659 	TAILQ_FOREACH(child, &dev->children, link) {
3660 		device_shutdown(child);
3661 	}
3662 
3663 	return (0);
3664 }
3665 
3666 /**
3667  * @brief Default function for suspending a child device.
3668  *
3669  * This function is to be used by a bus's DEVICE_SUSPEND_CHILD().
3670  */
3671 int
3672 bus_generic_suspend_child(device_t dev, device_t child)
3673 {
3674 	int	error;
3675 
3676 	error = DEVICE_SUSPEND(child);
3677 
3678 	if (error == 0)
3679 		child->flags |= DF_SUSPENDED;
3680 
3681 	return (error);
3682 }
3683 
3684 /**
3685  * @brief Default function for resuming a child device.
3686  *
3687  * This function is to be used by a bus's DEVICE_RESUME_CHILD().
3688  */
3689 int
3690 bus_generic_resume_child(device_t dev, device_t child)
3691 {
3692 
3693 	DEVICE_RESUME(child);
3694 	child->flags &= ~DF_SUSPENDED;
3695 
3696 	return (0);
3697 }
3698 
3699 /**
3700  * @brief Helper function for implementing DEVICE_SUSPEND()
3701  *
3702  * This function can be used to help implement the DEVICE_SUSPEND()
3703  * for a bus. It calls DEVICE_SUSPEND() for each of the device's
3704  * children. If any call to DEVICE_SUSPEND() fails, the suspend
3705  * operation is aborted and any devices which were suspended are
3706  * resumed immediately by calling their DEVICE_RESUME() methods.
3707  */
3708 int
3709 bus_generic_suspend(device_t dev)
3710 {
3711 	int		error;
3712 	device_t	child, child2;
3713 
3714 	TAILQ_FOREACH(child, &dev->children, link) {
3715 		error = BUS_SUSPEND_CHILD(dev, child);
3716 		if (error) {
3717 			for (child2 = TAILQ_FIRST(&dev->children);
3718 			     child2 && child2 != child;
3719 			     child2 = TAILQ_NEXT(child2, link))
3720 				BUS_RESUME_CHILD(dev, child2);
3721 			return (error);
3722 		}
3723 	}
3724 	return (0);
3725 }
3726 
3727 /**
3728  * @brief Helper function for implementing DEVICE_RESUME()
3729  *
3730  * This function can be used to help implement the DEVICE_RESUME() for
3731  * a bus. It calls DEVICE_RESUME() on each of the device's children.
3732  */
3733 int
3734 bus_generic_resume(device_t dev)
3735 {
3736 	device_t	child;
3737 
3738 	TAILQ_FOREACH(child, &dev->children, link) {
3739 		BUS_RESUME_CHILD(dev, child);
3740 		/* if resume fails, there's nothing we can usefully do... */
3741 	}
3742 	return (0);
3743 }
3744 
3745 /**
3746  * @brief Helper function for implementing BUS_PRINT_CHILD().
3747  *
3748  * This function prints the first part of the ascii representation of
3749  * @p child, including its name, unit and description (if any - see
3750  * device_set_desc()).
3751  *
3752  * @returns the number of characters printed
3753  */
3754 int
3755 bus_print_child_header(device_t dev, device_t child)
3756 {
3757 	int	retval = 0;
3758 
3759 	if (device_get_desc(child)) {
3760 		retval += device_printf(child, "<%s>", device_get_desc(child));
3761 	} else {
3762 		retval += printf("%s", device_get_nameunit(child));
3763 	}
3764 
3765 	return (retval);
3766 }
3767 
3768 /**
3769  * @brief Helper function for implementing BUS_PRINT_CHILD().
3770  *
3771  * This function prints the last part of the ascii representation of
3772  * @p child, which consists of the string @c " on " followed by the
3773  * name and unit of the @p dev.
3774  *
3775  * @returns the number of characters printed
3776  */
3777 int
3778 bus_print_child_footer(device_t dev, device_t child)
3779 {
3780 	return (printf(" on %s\n", device_get_nameunit(dev)));
3781 }
3782 
3783 /**
3784  * @brief Helper function for implementing BUS_PRINT_CHILD().
3785  *
3786  * This function prints out the VM domain for the given device.
3787  *
3788  * @returns the number of characters printed
3789  */
3790 int
3791 bus_print_child_domain(device_t dev, device_t child)
3792 {
3793 	int domain;
3794 
3795 	/* No domain? Don't print anything */
3796 	if (BUS_GET_DOMAIN(dev, child, &domain) != 0)
3797 		return (0);
3798 
3799 	return (printf(" numa-domain %d", domain));
3800 }
3801 
3802 /**
3803  * @brief Helper function for implementing BUS_PRINT_CHILD().
3804  *
3805  * This function simply calls bus_print_child_header() followed by
3806  * bus_print_child_footer().
3807  *
3808  * @returns the number of characters printed
3809  */
3810 int
3811 bus_generic_print_child(device_t dev, device_t child)
3812 {
3813 	int	retval = 0;
3814 
3815 	retval += bus_print_child_header(dev, child);
3816 	retval += bus_print_child_domain(dev, child);
3817 	retval += bus_print_child_footer(dev, child);
3818 
3819 	return (retval);
3820 }
3821 
3822 /**
3823  * @brief Stub function for implementing BUS_READ_IVAR().
3824  *
3825  * @returns ENOENT
3826  */
3827 int
3828 bus_generic_read_ivar(device_t dev, device_t child, int index,
3829     uintptr_t * result)
3830 {
3831 	return (ENOENT);
3832 }
3833 
3834 /**
3835  * @brief Stub function for implementing BUS_WRITE_IVAR().
3836  *
3837  * @returns ENOENT
3838  */
3839 int
3840 bus_generic_write_ivar(device_t dev, device_t child, int index,
3841     uintptr_t value)
3842 {
3843 	return (ENOENT);
3844 }
3845 
3846 /**
3847  * @brief Stub function for implementing BUS_GET_RESOURCE_LIST().
3848  *
3849  * @returns NULL
3850  */
3851 struct resource_list *
3852 bus_generic_get_resource_list(device_t dev, device_t child)
3853 {
3854 	return (NULL);
3855 }
3856 
3857 /**
3858  * @brief Helper function for implementing BUS_DRIVER_ADDED().
3859  *
3860  * This implementation of BUS_DRIVER_ADDED() simply calls the driver's
3861  * DEVICE_IDENTIFY() method to allow it to add new children to the bus
3862  * and then calls device_probe_and_attach() for each unattached child.
3863  */
3864 void
3865 bus_generic_driver_added(device_t dev, driver_t *driver)
3866 {
3867 	device_t child;
3868 
3869 	DEVICE_IDENTIFY(driver, dev);
3870 	TAILQ_FOREACH(child, &dev->children, link) {
3871 		if (child->state == DS_NOTPRESENT ||
3872 		    (child->flags & DF_REBID))
3873 			device_probe_and_attach(child);
3874 	}
3875 }
3876 
3877 /**
3878  * @brief Helper function for implementing BUS_NEW_PASS().
3879  *
3880  * This implementing of BUS_NEW_PASS() first calls the identify
3881  * routines for any drivers that probe at the current pass.  Then it
3882  * walks the list of devices for this bus.  If a device is already
3883  * attached, then it calls BUS_NEW_PASS() on that device.  If the
3884  * device is not already attached, it attempts to attach a driver to
3885  * it.
3886  */
3887 void
3888 bus_generic_new_pass(device_t dev)
3889 {
3890 	driverlink_t dl;
3891 	devclass_t dc;
3892 	device_t child;
3893 
3894 	dc = dev->devclass;
3895 	TAILQ_FOREACH(dl, &dc->drivers, link) {
3896 		if (dl->pass == bus_current_pass)
3897 			DEVICE_IDENTIFY(dl->driver, dev);
3898 	}
3899 	TAILQ_FOREACH(child, &dev->children, link) {
3900 		if (child->state >= DS_ATTACHED)
3901 			BUS_NEW_PASS(child);
3902 		else if (child->state == DS_NOTPRESENT)
3903 			device_probe_and_attach(child);
3904 	}
3905 }
3906 
3907 /**
3908  * @brief Helper function for implementing BUS_SETUP_INTR().
3909  *
3910  * This simple implementation of BUS_SETUP_INTR() simply calls the
3911  * BUS_SETUP_INTR() method of the parent of @p dev.
3912  */
3913 int
3914 bus_generic_setup_intr(device_t dev, device_t child, struct resource *irq,
3915     int flags, driver_filter_t *filter, driver_intr_t *intr, void *arg,
3916     void **cookiep)
3917 {
3918 	/* Propagate up the bus hierarchy until someone handles it. */
3919 	if (dev->parent)
3920 		return (BUS_SETUP_INTR(dev->parent, child, irq, flags,
3921 		    filter, intr, arg, cookiep));
3922 	return (EINVAL);
3923 }
3924 
3925 /**
3926  * @brief Helper function for implementing BUS_TEARDOWN_INTR().
3927  *
3928  * This simple implementation of BUS_TEARDOWN_INTR() simply calls the
3929  * BUS_TEARDOWN_INTR() method of the parent of @p dev.
3930  */
3931 int
3932 bus_generic_teardown_intr(device_t dev, device_t child, struct resource *irq,
3933     void *cookie)
3934 {
3935 	/* Propagate up the bus hierarchy until someone handles it. */
3936 	if (dev->parent)
3937 		return (BUS_TEARDOWN_INTR(dev->parent, child, irq, cookie));
3938 	return (EINVAL);
3939 }
3940 
3941 /**
3942  * @brief Helper function for implementing BUS_ADJUST_RESOURCE().
3943  *
3944  * This simple implementation of BUS_ADJUST_RESOURCE() simply calls the
3945  * BUS_ADJUST_RESOURCE() method of the parent of @p dev.
3946  */
3947 int
3948 bus_generic_adjust_resource(device_t dev, device_t child, int type,
3949     struct resource *r, u_long start, u_long end)
3950 {
3951 	/* Propagate up the bus hierarchy until someone handles it. */
3952 	if (dev->parent)
3953 		return (BUS_ADJUST_RESOURCE(dev->parent, child, type, r, start,
3954 		    end));
3955 	return (EINVAL);
3956 }
3957 
3958 /**
3959  * @brief Helper function for implementing BUS_ALLOC_RESOURCE().
3960  *
3961  * This simple implementation of BUS_ALLOC_RESOURCE() simply calls the
3962  * BUS_ALLOC_RESOURCE() method of the parent of @p dev.
3963  */
3964 struct resource *
3965 bus_generic_alloc_resource(device_t dev, device_t child, int type, int *rid,
3966     u_long start, u_long end, u_long count, u_int flags)
3967 {
3968 	/* Propagate up the bus hierarchy until someone handles it. */
3969 	if (dev->parent)
3970 		return (BUS_ALLOC_RESOURCE(dev->parent, child, type, rid,
3971 		    start, end, count, flags));
3972 	return (NULL);
3973 }
3974 
3975 /**
3976  * @brief Helper function for implementing BUS_RELEASE_RESOURCE().
3977  *
3978  * This simple implementation of BUS_RELEASE_RESOURCE() simply calls the
3979  * BUS_RELEASE_RESOURCE() method of the parent of @p dev.
3980  */
3981 int
3982 bus_generic_release_resource(device_t dev, device_t child, int type, int rid,
3983     struct resource *r)
3984 {
3985 	/* Propagate up the bus hierarchy until someone handles it. */
3986 	if (dev->parent)
3987 		return (BUS_RELEASE_RESOURCE(dev->parent, child, type, rid,
3988 		    r));
3989 	return (EINVAL);
3990 }
3991 
3992 /**
3993  * @brief Helper function for implementing BUS_ACTIVATE_RESOURCE().
3994  *
3995  * This simple implementation of BUS_ACTIVATE_RESOURCE() simply calls the
3996  * BUS_ACTIVATE_RESOURCE() method of the parent of @p dev.
3997  */
3998 int
3999 bus_generic_activate_resource(device_t dev, device_t child, int type, int rid,
4000     struct resource *r)
4001 {
4002 	/* Propagate up the bus hierarchy until someone handles it. */
4003 	if (dev->parent)
4004 		return (BUS_ACTIVATE_RESOURCE(dev->parent, child, type, rid,
4005 		    r));
4006 	return (EINVAL);
4007 }
4008 
4009 /**
4010  * @brief Helper function for implementing BUS_DEACTIVATE_RESOURCE().
4011  *
4012  * This simple implementation of BUS_DEACTIVATE_RESOURCE() simply calls the
4013  * BUS_DEACTIVATE_RESOURCE() method of the parent of @p dev.
4014  */
4015 int
4016 bus_generic_deactivate_resource(device_t dev, device_t child, int type,
4017     int rid, struct resource *r)
4018 {
4019 	/* Propagate up the bus hierarchy until someone handles it. */
4020 	if (dev->parent)
4021 		return (BUS_DEACTIVATE_RESOURCE(dev->parent, child, type, rid,
4022 		    r));
4023 	return (EINVAL);
4024 }
4025 
4026 /**
4027  * @brief Helper function for implementing BUS_BIND_INTR().
4028  *
4029  * This simple implementation of BUS_BIND_INTR() simply calls the
4030  * BUS_BIND_INTR() method of the parent of @p dev.
4031  */
4032 int
4033 bus_generic_bind_intr(device_t dev, device_t child, struct resource *irq,
4034     int cpu)
4035 {
4036 
4037 	/* Propagate up the bus hierarchy until someone handles it. */
4038 	if (dev->parent)
4039 		return (BUS_BIND_INTR(dev->parent, child, irq, cpu));
4040 	return (EINVAL);
4041 }
4042 
4043 /**
4044  * @brief Helper function for implementing BUS_CONFIG_INTR().
4045  *
4046  * This simple implementation of BUS_CONFIG_INTR() simply calls the
4047  * BUS_CONFIG_INTR() method of the parent of @p dev.
4048  */
4049 int
4050 bus_generic_config_intr(device_t dev, int irq, enum intr_trigger trig,
4051     enum intr_polarity pol)
4052 {
4053 
4054 	/* Propagate up the bus hierarchy until someone handles it. */
4055 	if (dev->parent)
4056 		return (BUS_CONFIG_INTR(dev->parent, irq, trig, pol));
4057 	return (EINVAL);
4058 }
4059 
4060 /**
4061  * @brief Helper function for implementing BUS_DESCRIBE_INTR().
4062  *
4063  * This simple implementation of BUS_DESCRIBE_INTR() simply calls the
4064  * BUS_DESCRIBE_INTR() method of the parent of @p dev.
4065  */
4066 int
4067 bus_generic_describe_intr(device_t dev, device_t child, struct resource *irq,
4068     void *cookie, const char *descr)
4069 {
4070 
4071 	/* Propagate up the bus hierarchy until someone handles it. */
4072 	if (dev->parent)
4073 		return (BUS_DESCRIBE_INTR(dev->parent, child, irq, cookie,
4074 		    descr));
4075 	return (EINVAL);
4076 }
4077 
4078 /**
4079  * @brief Helper function for implementing BUS_GET_DMA_TAG().
4080  *
4081  * This simple implementation of BUS_GET_DMA_TAG() simply calls the
4082  * BUS_GET_DMA_TAG() method of the parent of @p dev.
4083  */
4084 bus_dma_tag_t
4085 bus_generic_get_dma_tag(device_t dev, device_t child)
4086 {
4087 
4088 	/* Propagate up the bus hierarchy until someone handles it. */
4089 	if (dev->parent != NULL)
4090 		return (BUS_GET_DMA_TAG(dev->parent, child));
4091 	return (NULL);
4092 }
4093 
4094 /**
4095  * @brief Helper function for implementing BUS_GET_RESOURCE().
4096  *
4097  * This implementation of BUS_GET_RESOURCE() uses the
4098  * resource_list_find() function to do most of the work. It calls
4099  * BUS_GET_RESOURCE_LIST() to find a suitable resource list to
4100  * search.
4101  */
4102 int
4103 bus_generic_rl_get_resource(device_t dev, device_t child, int type, int rid,
4104     u_long *startp, u_long *countp)
4105 {
4106 	struct resource_list *		rl = NULL;
4107 	struct resource_list_entry *	rle = NULL;
4108 
4109 	rl = BUS_GET_RESOURCE_LIST(dev, child);
4110 	if (!rl)
4111 		return (EINVAL);
4112 
4113 	rle = resource_list_find(rl, type, rid);
4114 	if (!rle)
4115 		return (ENOENT);
4116 
4117 	if (startp)
4118 		*startp = rle->start;
4119 	if (countp)
4120 		*countp = rle->count;
4121 
4122 	return (0);
4123 }
4124 
4125 /**
4126  * @brief Helper function for implementing BUS_SET_RESOURCE().
4127  *
4128  * This implementation of BUS_SET_RESOURCE() uses the
4129  * resource_list_add() function to do most of the work. It calls
4130  * BUS_GET_RESOURCE_LIST() to find a suitable resource list to
4131  * edit.
4132  */
4133 int
4134 bus_generic_rl_set_resource(device_t dev, device_t child, int type, int rid,
4135     u_long start, u_long count)
4136 {
4137 	struct resource_list *		rl = NULL;
4138 
4139 	rl = BUS_GET_RESOURCE_LIST(dev, child);
4140 	if (!rl)
4141 		return (EINVAL);
4142 
4143 	resource_list_add(rl, type, rid, start, (start + count - 1), count);
4144 
4145 	return (0);
4146 }
4147 
4148 /**
4149  * @brief Helper function for implementing BUS_DELETE_RESOURCE().
4150  *
4151  * This implementation of BUS_DELETE_RESOURCE() uses the
4152  * resource_list_delete() function to do most of the work. It calls
4153  * BUS_GET_RESOURCE_LIST() to find a suitable resource list to
4154  * edit.
4155  */
4156 void
4157 bus_generic_rl_delete_resource(device_t dev, device_t child, int type, int rid)
4158 {
4159 	struct resource_list *		rl = NULL;
4160 
4161 	rl = BUS_GET_RESOURCE_LIST(dev, child);
4162 	if (!rl)
4163 		return;
4164 
4165 	resource_list_delete(rl, type, rid);
4166 
4167 	return;
4168 }
4169 
4170 /**
4171  * @brief Helper function for implementing BUS_RELEASE_RESOURCE().
4172  *
4173  * This implementation of BUS_RELEASE_RESOURCE() uses the
4174  * resource_list_release() function to do most of the work. It calls
4175  * BUS_GET_RESOURCE_LIST() to find a suitable resource list.
4176  */
4177 int
4178 bus_generic_rl_release_resource(device_t dev, device_t child, int type,
4179     int rid, struct resource *r)
4180 {
4181 	struct resource_list *		rl = NULL;
4182 
4183 	if (device_get_parent(child) != dev)
4184 		return (BUS_RELEASE_RESOURCE(device_get_parent(dev), child,
4185 		    type, rid, r));
4186 
4187 	rl = BUS_GET_RESOURCE_LIST(dev, child);
4188 	if (!rl)
4189 		return (EINVAL);
4190 
4191 	return (resource_list_release(rl, dev, child, type, rid, r));
4192 }
4193 
4194 /**
4195  * @brief Helper function for implementing BUS_ALLOC_RESOURCE().
4196  *
4197  * This implementation of BUS_ALLOC_RESOURCE() uses the
4198  * resource_list_alloc() function to do most of the work. It calls
4199  * BUS_GET_RESOURCE_LIST() to find a suitable resource list.
4200  */
4201 struct resource *
4202 bus_generic_rl_alloc_resource(device_t dev, device_t child, int type,
4203     int *rid, u_long start, u_long end, u_long count, u_int flags)
4204 {
4205 	struct resource_list *		rl = NULL;
4206 
4207 	if (device_get_parent(child) != dev)
4208 		return (BUS_ALLOC_RESOURCE(device_get_parent(dev), child,
4209 		    type, rid, start, end, count, flags));
4210 
4211 	rl = BUS_GET_RESOURCE_LIST(dev, child);
4212 	if (!rl)
4213 		return (NULL);
4214 
4215 	return (resource_list_alloc(rl, dev, child, type, rid,
4216 	    start, end, count, flags));
4217 }
4218 
4219 /**
4220  * @brief Helper function for implementing BUS_CHILD_PRESENT().
4221  *
4222  * This simple implementation of BUS_CHILD_PRESENT() simply calls the
4223  * BUS_CHILD_PRESENT() method of the parent of @p dev.
4224  */
4225 int
4226 bus_generic_child_present(device_t dev, device_t child)
4227 {
4228 	return (BUS_CHILD_PRESENT(device_get_parent(dev), dev));
4229 }
4230 
4231 int
4232 bus_generic_get_domain(device_t dev, device_t child, int *domain)
4233 {
4234 
4235 	if (dev->parent)
4236 		return (BUS_GET_DOMAIN(dev->parent, dev, domain));
4237 
4238 	return (ENOENT);
4239 }
4240 
4241 /*
4242  * Some convenience functions to make it easier for drivers to use the
4243  * resource-management functions.  All these really do is hide the
4244  * indirection through the parent's method table, making for slightly
4245  * less-wordy code.  In the future, it might make sense for this code
4246  * to maintain some sort of a list of resources allocated by each device.
4247  */
4248 
4249 int
4250 bus_alloc_resources(device_t dev, struct resource_spec *rs,
4251     struct resource **res)
4252 {
4253 	int i;
4254 
4255 	for (i = 0; rs[i].type != -1; i++)
4256 		res[i] = NULL;
4257 	for (i = 0; rs[i].type != -1; i++) {
4258 		res[i] = bus_alloc_resource_any(dev,
4259 		    rs[i].type, &rs[i].rid, rs[i].flags);
4260 		if (res[i] == NULL && !(rs[i].flags & RF_OPTIONAL)) {
4261 			bus_release_resources(dev, rs, res);
4262 			return (ENXIO);
4263 		}
4264 	}
4265 	return (0);
4266 }
4267 
4268 void
4269 bus_release_resources(device_t dev, const struct resource_spec *rs,
4270     struct resource **res)
4271 {
4272 	int i;
4273 
4274 	for (i = 0; rs[i].type != -1; i++)
4275 		if (res[i] != NULL) {
4276 			bus_release_resource(
4277 			    dev, rs[i].type, rs[i].rid, res[i]);
4278 			res[i] = NULL;
4279 		}
4280 }
4281 
4282 /**
4283  * @brief Wrapper function for BUS_ALLOC_RESOURCE().
4284  *
4285  * This function simply calls the BUS_ALLOC_RESOURCE() method of the
4286  * parent of @p dev.
4287  */
4288 struct resource *
4289 bus_alloc_resource(device_t dev, int type, int *rid, u_long start, u_long end,
4290     u_long count, u_int flags)
4291 {
4292 	if (dev->parent == NULL)
4293 		return (NULL);
4294 	return (BUS_ALLOC_RESOURCE(dev->parent, dev, type, rid, start, end,
4295 	    count, flags));
4296 }
4297 
4298 /**
4299  * @brief Wrapper function for BUS_ADJUST_RESOURCE().
4300  *
4301  * This function simply calls the BUS_ADJUST_RESOURCE() method of the
4302  * parent of @p dev.
4303  */
4304 int
4305 bus_adjust_resource(device_t dev, int type, struct resource *r, u_long start,
4306     u_long end)
4307 {
4308 	if (dev->parent == NULL)
4309 		return (EINVAL);
4310 	return (BUS_ADJUST_RESOURCE(dev->parent, dev, type, r, start, end));
4311 }
4312 
4313 /**
4314  * @brief Wrapper function for BUS_ACTIVATE_RESOURCE().
4315  *
4316  * This function simply calls the BUS_ACTIVATE_RESOURCE() method of the
4317  * parent of @p dev.
4318  */
4319 int
4320 bus_activate_resource(device_t dev, int type, int rid, struct resource *r)
4321 {
4322 	if (dev->parent == NULL)
4323 		return (EINVAL);
4324 	return (BUS_ACTIVATE_RESOURCE(dev->parent, dev, type, rid, r));
4325 }
4326 
4327 /**
4328  * @brief Wrapper function for BUS_DEACTIVATE_RESOURCE().
4329  *
4330  * This function simply calls the BUS_DEACTIVATE_RESOURCE() method of the
4331  * parent of @p dev.
4332  */
4333 int
4334 bus_deactivate_resource(device_t dev, int type, int rid, struct resource *r)
4335 {
4336 	if (dev->parent == NULL)
4337 		return (EINVAL);
4338 	return (BUS_DEACTIVATE_RESOURCE(dev->parent, dev, type, rid, r));
4339 }
4340 
4341 /**
4342  * @brief Wrapper function for BUS_RELEASE_RESOURCE().
4343  *
4344  * This function simply calls the BUS_RELEASE_RESOURCE() method of the
4345  * parent of @p dev.
4346  */
4347 int
4348 bus_release_resource(device_t dev, int type, int rid, struct resource *r)
4349 {
4350 	if (dev->parent == NULL)
4351 		return (EINVAL);
4352 	return (BUS_RELEASE_RESOURCE(dev->parent, dev, type, rid, r));
4353 }
4354 
4355 /**
4356  * @brief Wrapper function for BUS_SETUP_INTR().
4357  *
4358  * This function simply calls the BUS_SETUP_INTR() method of the
4359  * parent of @p dev.
4360  */
4361 int
4362 bus_setup_intr(device_t dev, struct resource *r, int flags,
4363     driver_filter_t filter, driver_intr_t handler, void *arg, void **cookiep)
4364 {
4365 	int error;
4366 
4367 	if (dev->parent == NULL)
4368 		return (EINVAL);
4369 	error = BUS_SETUP_INTR(dev->parent, dev, r, flags, filter, handler,
4370 	    arg, cookiep);
4371 	if (error != 0)
4372 		return (error);
4373 	if (handler != NULL && !(flags & INTR_MPSAFE))
4374 		device_printf(dev, "[GIANT-LOCKED]\n");
4375 	return (0);
4376 }
4377 
4378 /**
4379  * @brief Wrapper function for BUS_TEARDOWN_INTR().
4380  *
4381  * This function simply calls the BUS_TEARDOWN_INTR() method of the
4382  * parent of @p dev.
4383  */
4384 int
4385 bus_teardown_intr(device_t dev, struct resource *r, void *cookie)
4386 {
4387 	if (dev->parent == NULL)
4388 		return (EINVAL);
4389 	return (BUS_TEARDOWN_INTR(dev->parent, dev, r, cookie));
4390 }
4391 
4392 /**
4393  * @brief Wrapper function for BUS_BIND_INTR().
4394  *
4395  * This function simply calls the BUS_BIND_INTR() method of the
4396  * parent of @p dev.
4397  */
4398 int
4399 bus_bind_intr(device_t dev, struct resource *r, int cpu)
4400 {
4401 	if (dev->parent == NULL)
4402 		return (EINVAL);
4403 	return (BUS_BIND_INTR(dev->parent, dev, r, cpu));
4404 }
4405 
4406 /**
4407  * @brief Wrapper function for BUS_DESCRIBE_INTR().
4408  *
4409  * This function first formats the requested description into a
4410  * temporary buffer and then calls the BUS_DESCRIBE_INTR() method of
4411  * the parent of @p dev.
4412  */
4413 int
4414 bus_describe_intr(device_t dev, struct resource *irq, void *cookie,
4415     const char *fmt, ...)
4416 {
4417 	va_list ap;
4418 	char descr[MAXCOMLEN + 1];
4419 
4420 	if (dev->parent == NULL)
4421 		return (EINVAL);
4422 	va_start(ap, fmt);
4423 	vsnprintf(descr, sizeof(descr), fmt, ap);
4424 	va_end(ap);
4425 	return (BUS_DESCRIBE_INTR(dev->parent, dev, irq, cookie, descr));
4426 }
4427 
4428 /**
4429  * @brief Wrapper function for BUS_SET_RESOURCE().
4430  *
4431  * This function simply calls the BUS_SET_RESOURCE() method of the
4432  * parent of @p dev.
4433  */
4434 int
4435 bus_set_resource(device_t dev, int type, int rid,
4436     u_long start, u_long count)
4437 {
4438 	return (BUS_SET_RESOURCE(device_get_parent(dev), dev, type, rid,
4439 	    start, count));
4440 }
4441 
4442 /**
4443  * @brief Wrapper function for BUS_GET_RESOURCE().
4444  *
4445  * This function simply calls the BUS_GET_RESOURCE() method of the
4446  * parent of @p dev.
4447  */
4448 int
4449 bus_get_resource(device_t dev, int type, int rid,
4450     u_long *startp, u_long *countp)
4451 {
4452 	return (BUS_GET_RESOURCE(device_get_parent(dev), dev, type, rid,
4453 	    startp, countp));
4454 }
4455 
4456 /**
4457  * @brief Wrapper function for BUS_GET_RESOURCE().
4458  *
4459  * This function simply calls the BUS_GET_RESOURCE() method of the
4460  * parent of @p dev and returns the start value.
4461  */
4462 u_long
4463 bus_get_resource_start(device_t dev, int type, int rid)
4464 {
4465 	u_long start, count;
4466 	int error;
4467 
4468 	error = BUS_GET_RESOURCE(device_get_parent(dev), dev, type, rid,
4469 	    &start, &count);
4470 	if (error)
4471 		return (0);
4472 	return (start);
4473 }
4474 
4475 /**
4476  * @brief Wrapper function for BUS_GET_RESOURCE().
4477  *
4478  * This function simply calls the BUS_GET_RESOURCE() method of the
4479  * parent of @p dev and returns the count value.
4480  */
4481 u_long
4482 bus_get_resource_count(device_t dev, int type, int rid)
4483 {
4484 	u_long start, count;
4485 	int error;
4486 
4487 	error = BUS_GET_RESOURCE(device_get_parent(dev), dev, type, rid,
4488 	    &start, &count);
4489 	if (error)
4490 		return (0);
4491 	return (count);
4492 }
4493 
4494 /**
4495  * @brief Wrapper function for BUS_DELETE_RESOURCE().
4496  *
4497  * This function simply calls the BUS_DELETE_RESOURCE() method of the
4498  * parent of @p dev.
4499  */
4500 void
4501 bus_delete_resource(device_t dev, int type, int rid)
4502 {
4503 	BUS_DELETE_RESOURCE(device_get_parent(dev), dev, type, rid);
4504 }
4505 
4506 /**
4507  * @brief Wrapper function for BUS_CHILD_PRESENT().
4508  *
4509  * This function simply calls the BUS_CHILD_PRESENT() method of the
4510  * parent of @p dev.
4511  */
4512 int
4513 bus_child_present(device_t child)
4514 {
4515 	return (BUS_CHILD_PRESENT(device_get_parent(child), child));
4516 }
4517 
4518 /**
4519  * @brief Wrapper function for BUS_CHILD_PNPINFO_STR().
4520  *
4521  * This function simply calls the BUS_CHILD_PNPINFO_STR() method of the
4522  * parent of @p dev.
4523  */
4524 int
4525 bus_child_pnpinfo_str(device_t child, char *buf, size_t buflen)
4526 {
4527 	device_t parent;
4528 
4529 	parent = device_get_parent(child);
4530 	if (parent == NULL) {
4531 		*buf = '\0';
4532 		return (0);
4533 	}
4534 	return (BUS_CHILD_PNPINFO_STR(parent, child, buf, buflen));
4535 }
4536 
4537 /**
4538  * @brief Wrapper function for BUS_CHILD_LOCATION_STR().
4539  *
4540  * This function simply calls the BUS_CHILD_LOCATION_STR() method of the
4541  * parent of @p dev.
4542  */
4543 int
4544 bus_child_location_str(device_t child, char *buf, size_t buflen)
4545 {
4546 	device_t parent;
4547 
4548 	parent = device_get_parent(child);
4549 	if (parent == NULL) {
4550 		*buf = '\0';
4551 		return (0);
4552 	}
4553 	return (BUS_CHILD_LOCATION_STR(parent, child, buf, buflen));
4554 }
4555 
4556 /**
4557  * @brief Wrapper function for BUS_GET_DMA_TAG().
4558  *
4559  * This function simply calls the BUS_GET_DMA_TAG() method of the
4560  * parent of @p dev.
4561  */
4562 bus_dma_tag_t
4563 bus_get_dma_tag(device_t dev)
4564 {
4565 	device_t parent;
4566 
4567 	parent = device_get_parent(dev);
4568 	if (parent == NULL)
4569 		return (NULL);
4570 	return (BUS_GET_DMA_TAG(parent, dev));
4571 }
4572 
4573 /**
4574  * @brief Wrapper function for BUS_GET_DOMAIN().
4575  *
4576  * This function simply calls the BUS_GET_DOMAIN() method of the
4577  * parent of @p dev.
4578  */
4579 int
4580 bus_get_domain(device_t dev, int *domain)
4581 {
4582 	return (BUS_GET_DOMAIN(device_get_parent(dev), dev, domain));
4583 }
4584 
4585 /* Resume all devices and then notify userland that we're up again. */
4586 static int
4587 root_resume(device_t dev)
4588 {
4589 	int error;
4590 
4591 	error = bus_generic_resume(dev);
4592 	if (error == 0)
4593 		devctl_notify("kern", "power", "resume", NULL);
4594 	return (error);
4595 }
4596 
4597 static int
4598 root_print_child(device_t dev, device_t child)
4599 {
4600 	int	retval = 0;
4601 
4602 	retval += bus_print_child_header(dev, child);
4603 	retval += printf("\n");
4604 
4605 	return (retval);
4606 }
4607 
4608 static int
4609 root_setup_intr(device_t dev, device_t child, struct resource *irq, int flags,
4610     driver_filter_t *filter, driver_intr_t *intr, void *arg, void **cookiep)
4611 {
4612 	/*
4613 	 * If an interrupt mapping gets to here something bad has happened.
4614 	 */
4615 	panic("root_setup_intr");
4616 }
4617 
4618 /*
4619  * If we get here, assume that the device is permanant and really is
4620  * present in the system.  Removable bus drivers are expected to intercept
4621  * this call long before it gets here.  We return -1 so that drivers that
4622  * really care can check vs -1 or some ERRNO returned higher in the food
4623  * chain.
4624  */
4625 static int
4626 root_child_present(device_t dev, device_t child)
4627 {
4628 	return (-1);
4629 }
4630 
4631 static kobj_method_t root_methods[] = {
4632 	/* Device interface */
4633 	KOBJMETHOD(device_shutdown,	bus_generic_shutdown),
4634 	KOBJMETHOD(device_suspend,	bus_generic_suspend),
4635 	KOBJMETHOD(device_resume,	root_resume),
4636 
4637 	/* Bus interface */
4638 	KOBJMETHOD(bus_print_child,	root_print_child),
4639 	KOBJMETHOD(bus_read_ivar,	bus_generic_read_ivar),
4640 	KOBJMETHOD(bus_write_ivar,	bus_generic_write_ivar),
4641 	KOBJMETHOD(bus_setup_intr,	root_setup_intr),
4642 	KOBJMETHOD(bus_child_present,	root_child_present),
4643 
4644 	KOBJMETHOD_END
4645 };
4646 
4647 static driver_t root_driver = {
4648 	"root",
4649 	root_methods,
4650 	1,			/* no softc */
4651 };
4652 
4653 device_t	root_bus;
4654 devclass_t	root_devclass;
4655 
4656 static int
4657 root_bus_module_handler(module_t mod, int what, void* arg)
4658 {
4659 	switch (what) {
4660 	case MOD_LOAD:
4661 		TAILQ_INIT(&bus_data_devices);
4662 		kobj_class_compile((kobj_class_t) &root_driver);
4663 		root_bus = make_device(NULL, "root", 0);
4664 		root_bus->desc = "System root bus";
4665 		kobj_init((kobj_t) root_bus, (kobj_class_t) &root_driver);
4666 		root_bus->driver = &root_driver;
4667 		root_bus->state = DS_ATTACHED;
4668 		root_devclass = devclass_find_internal("root", NULL, FALSE);
4669 		devinit();
4670 		return (0);
4671 
4672 	case MOD_SHUTDOWN:
4673 		device_shutdown(root_bus);
4674 		return (0);
4675 	default:
4676 		return (EOPNOTSUPP);
4677 	}
4678 
4679 	return (0);
4680 }
4681 
4682 static moduledata_t root_bus_mod = {
4683 	"rootbus",
4684 	root_bus_module_handler,
4685 	NULL
4686 };
4687 DECLARE_MODULE(rootbus, root_bus_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
4688 
4689 /**
4690  * @brief Automatically configure devices
4691  *
4692  * This function begins the autoconfiguration process by calling
4693  * device_probe_and_attach() for each child of the @c root0 device.
4694  */
4695 void
4696 root_bus_configure(void)
4697 {
4698 
4699 	PDEBUG(("."));
4700 
4701 	/* Eventually this will be split up, but this is sufficient for now. */
4702 	bus_set_pass(BUS_PASS_DEFAULT);
4703 }
4704 
4705 /**
4706  * @brief Module handler for registering device drivers
4707  *
4708  * This module handler is used to automatically register device
4709  * drivers when modules are loaded. If @p what is MOD_LOAD, it calls
4710  * devclass_add_driver() for the driver described by the
4711  * driver_module_data structure pointed to by @p arg
4712  */
4713 int
4714 driver_module_handler(module_t mod, int what, void *arg)
4715 {
4716 	struct driver_module_data *dmd;
4717 	devclass_t bus_devclass;
4718 	kobj_class_t driver;
4719 	int error, pass;
4720 
4721 	dmd = (struct driver_module_data *)arg;
4722 	bus_devclass = devclass_find_internal(dmd->dmd_busname, NULL, TRUE);
4723 	error = 0;
4724 
4725 	switch (what) {
4726 	case MOD_LOAD:
4727 		if (dmd->dmd_chainevh)
4728 			error = dmd->dmd_chainevh(mod,what,dmd->dmd_chainarg);
4729 
4730 		pass = dmd->dmd_pass;
4731 		driver = dmd->dmd_driver;
4732 		PDEBUG(("Loading module: driver %s on bus %s (pass %d)",
4733 		    DRIVERNAME(driver), dmd->dmd_busname, pass));
4734 		error = devclass_add_driver(bus_devclass, driver, pass,
4735 		    dmd->dmd_devclass);
4736 		break;
4737 
4738 	case MOD_UNLOAD:
4739 		PDEBUG(("Unloading module: driver %s from bus %s",
4740 		    DRIVERNAME(dmd->dmd_driver),
4741 		    dmd->dmd_busname));
4742 		error = devclass_delete_driver(bus_devclass,
4743 		    dmd->dmd_driver);
4744 
4745 		if (!error && dmd->dmd_chainevh)
4746 			error = dmd->dmd_chainevh(mod,what,dmd->dmd_chainarg);
4747 		break;
4748 	case MOD_QUIESCE:
4749 		PDEBUG(("Quiesce module: driver %s from bus %s",
4750 		    DRIVERNAME(dmd->dmd_driver),
4751 		    dmd->dmd_busname));
4752 		error = devclass_quiesce_driver(bus_devclass,
4753 		    dmd->dmd_driver);
4754 
4755 		if (!error && dmd->dmd_chainevh)
4756 			error = dmd->dmd_chainevh(mod,what,dmd->dmd_chainarg);
4757 		break;
4758 	default:
4759 		error = EOPNOTSUPP;
4760 		break;
4761 	}
4762 
4763 	return (error);
4764 }
4765 
4766 /**
4767  * @brief Enumerate all hinted devices for this bus.
4768  *
4769  * Walks through the hints for this bus and calls the bus_hinted_child
4770  * routine for each one it fines.  It searches first for the specific
4771  * bus that's being probed for hinted children (eg isa0), and then for
4772  * generic children (eg isa).
4773  *
4774  * @param	dev	bus device to enumerate
4775  */
4776 void
4777 bus_enumerate_hinted_children(device_t bus)
4778 {
4779 	int i;
4780 	const char *dname, *busname;
4781 	int dunit;
4782 
4783 	/*
4784 	 * enumerate all devices on the specific bus
4785 	 */
4786 	busname = device_get_nameunit(bus);
4787 	i = 0;
4788 	while (resource_find_match(&i, &dname, &dunit, "at", busname) == 0)
4789 		BUS_HINTED_CHILD(bus, dname, dunit);
4790 
4791 	/*
4792 	 * and all the generic ones.
4793 	 */
4794 	busname = device_get_name(bus);
4795 	i = 0;
4796 	while (resource_find_match(&i, &dname, &dunit, "at", busname) == 0)
4797 		BUS_HINTED_CHILD(bus, dname, dunit);
4798 }
4799 
4800 #ifdef BUS_DEBUG
4801 
4802 /* the _short versions avoid iteration by not calling anything that prints
4803  * more than oneliners. I love oneliners.
4804  */
4805 
4806 static void
4807 print_device_short(device_t dev, int indent)
4808 {
4809 	if (!dev)
4810 		return;
4811 
4812 	indentprintf(("device %d: <%s> %sparent,%schildren,%s%s%s%s%s,%sivars,%ssoftc,busy=%d\n",
4813 	    dev->unit, dev->desc,
4814 	    (dev->parent? "":"no "),
4815 	    (TAILQ_EMPTY(&dev->children)? "no ":""),
4816 	    (dev->flags&DF_ENABLED? "enabled,":"disabled,"),
4817 	    (dev->flags&DF_FIXEDCLASS? "fixed,":""),
4818 	    (dev->flags&DF_WILDCARD? "wildcard,":""),
4819 	    (dev->flags&DF_DESCMALLOCED? "descmalloced,":""),
4820 	    (dev->flags&DF_REBID? "rebiddable,":""),
4821 	    (dev->ivars? "":"no "),
4822 	    (dev->softc? "":"no "),
4823 	    dev->busy));
4824 }
4825 
4826 static void
4827 print_device(device_t dev, int indent)
4828 {
4829 	if (!dev)
4830 		return;
4831 
4832 	print_device_short(dev, indent);
4833 
4834 	indentprintf(("Parent:\n"));
4835 	print_device_short(dev->parent, indent+1);
4836 	indentprintf(("Driver:\n"));
4837 	print_driver_short(dev->driver, indent+1);
4838 	indentprintf(("Devclass:\n"));
4839 	print_devclass_short(dev->devclass, indent+1);
4840 }
4841 
4842 void
4843 print_device_tree_short(device_t dev, int indent)
4844 /* print the device and all its children (indented) */
4845 {
4846 	device_t child;
4847 
4848 	if (!dev)
4849 		return;
4850 
4851 	print_device_short(dev, indent);
4852 
4853 	TAILQ_FOREACH(child, &dev->children, link) {
4854 		print_device_tree_short(child, indent+1);
4855 	}
4856 }
4857 
4858 void
4859 print_device_tree(device_t dev, int indent)
4860 /* print the device and all its children (indented) */
4861 {
4862 	device_t child;
4863 
4864 	if (!dev)
4865 		return;
4866 
4867 	print_device(dev, indent);
4868 
4869 	TAILQ_FOREACH(child, &dev->children, link) {
4870 		print_device_tree(child, indent+1);
4871 	}
4872 }
4873 
4874 static void
4875 print_driver_short(driver_t *driver, int indent)
4876 {
4877 	if (!driver)
4878 		return;
4879 
4880 	indentprintf(("driver %s: softc size = %zd\n",
4881 	    driver->name, driver->size));
4882 }
4883 
4884 static void
4885 print_driver(driver_t *driver, int indent)
4886 {
4887 	if (!driver)
4888 		return;
4889 
4890 	print_driver_short(driver, indent);
4891 }
4892 
4893 static void
4894 print_driver_list(driver_list_t drivers, int indent)
4895 {
4896 	driverlink_t driver;
4897 
4898 	TAILQ_FOREACH(driver, &drivers, link) {
4899 		print_driver(driver->driver, indent);
4900 	}
4901 }
4902 
4903 static void
4904 print_devclass_short(devclass_t dc, int indent)
4905 {
4906 	if ( !dc )
4907 		return;
4908 
4909 	indentprintf(("devclass %s: max units = %d\n", dc->name, dc->maxunit));
4910 }
4911 
4912 static void
4913 print_devclass(devclass_t dc, int indent)
4914 {
4915 	int i;
4916 
4917 	if ( !dc )
4918 		return;
4919 
4920 	print_devclass_short(dc, indent);
4921 	indentprintf(("Drivers:\n"));
4922 	print_driver_list(dc->drivers, indent+1);
4923 
4924 	indentprintf(("Devices:\n"));
4925 	for (i = 0; i < dc->maxunit; i++)
4926 		if (dc->devices[i])
4927 			print_device(dc->devices[i], indent+1);
4928 }
4929 
4930 void
4931 print_devclass_list_short(void)
4932 {
4933 	devclass_t dc;
4934 
4935 	printf("Short listing of devclasses, drivers & devices:\n");
4936 	TAILQ_FOREACH(dc, &devclasses, link) {
4937 		print_devclass_short(dc, 0);
4938 	}
4939 }
4940 
4941 void
4942 print_devclass_list(void)
4943 {
4944 	devclass_t dc;
4945 
4946 	printf("Full listing of devclasses, drivers & devices:\n");
4947 	TAILQ_FOREACH(dc, &devclasses, link) {
4948 		print_devclass(dc, 0);
4949 	}
4950 }
4951 
4952 #endif
4953 
4954 /*
4955  * User-space access to the device tree.
4956  *
4957  * We implement a small set of nodes:
4958  *
4959  * hw.bus			Single integer read method to obtain the
4960  *				current generation count.
4961  * hw.bus.devices		Reads the entire device tree in flat space.
4962  * hw.bus.rman			Resource manager interface
4963  *
4964  * We might like to add the ability to scan devclasses and/or drivers to
4965  * determine what else is currently loaded/available.
4966  */
4967 
4968 static int
4969 sysctl_bus(SYSCTL_HANDLER_ARGS)
4970 {
4971 	struct u_businfo	ubus;
4972 
4973 	ubus.ub_version = BUS_USER_VERSION;
4974 	ubus.ub_generation = bus_data_generation;
4975 
4976 	return (SYSCTL_OUT(req, &ubus, sizeof(ubus)));
4977 }
4978 SYSCTL_NODE(_hw_bus, OID_AUTO, info, CTLFLAG_RW, sysctl_bus,
4979     "bus-related data");
4980 
4981 static int
4982 sysctl_devices(SYSCTL_HANDLER_ARGS)
4983 {
4984 	int			*name = (int *)arg1;
4985 	u_int			namelen = arg2;
4986 	int			index;
4987 	struct device		*dev;
4988 	struct u_device		udev;	/* XXX this is a bit big */
4989 	int			error;
4990 
4991 	if (namelen != 2)
4992 		return (EINVAL);
4993 
4994 	if (bus_data_generation_check(name[0]))
4995 		return (EINVAL);
4996 
4997 	index = name[1];
4998 
4999 	/*
5000 	 * Scan the list of devices, looking for the requested index.
5001 	 */
5002 	TAILQ_FOREACH(dev, &bus_data_devices, devlink) {
5003 		if (index-- == 0)
5004 			break;
5005 	}
5006 	if (dev == NULL)
5007 		return (ENOENT);
5008 
5009 	/*
5010 	 * Populate the return array.
5011 	 */
5012 	bzero(&udev, sizeof(udev));
5013 	udev.dv_handle = (uintptr_t)dev;
5014 	udev.dv_parent = (uintptr_t)dev->parent;
5015 	if (dev->nameunit != NULL)
5016 		strlcpy(udev.dv_name, dev->nameunit, sizeof(udev.dv_name));
5017 	if (dev->desc != NULL)
5018 		strlcpy(udev.dv_desc, dev->desc, sizeof(udev.dv_desc));
5019 	if (dev->driver != NULL && dev->driver->name != NULL)
5020 		strlcpy(udev.dv_drivername, dev->driver->name,
5021 		    sizeof(udev.dv_drivername));
5022 	bus_child_pnpinfo_str(dev, udev.dv_pnpinfo, sizeof(udev.dv_pnpinfo));
5023 	bus_child_location_str(dev, udev.dv_location, sizeof(udev.dv_location));
5024 	udev.dv_devflags = dev->devflags;
5025 	udev.dv_flags = dev->flags;
5026 	udev.dv_state = dev->state;
5027 	error = SYSCTL_OUT(req, &udev, sizeof(udev));
5028 	return (error);
5029 }
5030 
5031 SYSCTL_NODE(_hw_bus, OID_AUTO, devices, CTLFLAG_RD, sysctl_devices,
5032     "system device tree");
5033 
5034 int
5035 bus_data_generation_check(int generation)
5036 {
5037 	if (generation != bus_data_generation)
5038 		return (1);
5039 
5040 	/* XXX generate optimised lists here? */
5041 	return (0);
5042 }
5043 
5044 void
5045 bus_data_generation_update(void)
5046 {
5047 	bus_data_generation++;
5048 }
5049 
5050 int
5051 bus_free_resource(device_t dev, int type, struct resource *r)
5052 {
5053 	if (r == NULL)
5054 		return (0);
5055 	return (bus_release_resource(dev, type, rman_get_rid(r), r));
5056 }
5057 
5058 /*
5059  * /dev/devctl2 implementation.  The existing /dev/devctl device has
5060  * implicit semantics on open, so it could not be reused for this.
5061  * Another option would be to call this /dev/bus?
5062  */
5063 static int
5064 find_device(struct devreq *req, device_t *devp)
5065 {
5066 	device_t dev;
5067 
5068 	/*
5069 	 * First, ensure that the name is nul terminated.
5070 	 */
5071 	if (memchr(req->dr_name, '\0', sizeof(req->dr_name)) == NULL)
5072 		return (EINVAL);
5073 
5074 	/*
5075 	 * Second, try to find an attached device whose name matches
5076 	 * 'name'.
5077 	 */
5078 	TAILQ_FOREACH(dev, &bus_data_devices, devlink) {
5079 		if (dev->nameunit != NULL &&
5080 		    strcmp(dev->nameunit, req->dr_name) == 0) {
5081 			*devp = dev;
5082 			return (0);
5083 		}
5084 	}
5085 
5086 	/* Finally, give device enumerators a chance. */
5087 	dev = NULL;
5088 	EVENTHANDLER_INVOKE(dev_lookup, req->dr_name, &dev);
5089 	if (dev == NULL)
5090 		return (ENOENT);
5091 	*devp = dev;
5092 	return (0);
5093 }
5094 
5095 static bool
5096 driver_exists(struct device *bus, const char *driver)
5097 {
5098 	devclass_t dc;
5099 
5100 	for (dc = bus->devclass; dc != NULL; dc = dc->parent) {
5101 		if (devclass_find_driver_internal(dc, driver) != NULL)
5102 			return (true);
5103 	}
5104 	return (false);
5105 }
5106 
5107 static int
5108 devctl2_ioctl(struct cdev *cdev, u_long cmd, caddr_t data, int fflag,
5109     struct thread *td)
5110 {
5111 	struct devreq *req;
5112 	device_t dev;
5113 	int error, old;
5114 
5115 	/* Locate the device to control. */
5116 	mtx_lock(&Giant);
5117 	req = (struct devreq *)data;
5118 	switch (cmd) {
5119 	case DEV_ATTACH:
5120 	case DEV_DETACH:
5121 	case DEV_ENABLE:
5122 	case DEV_DISABLE:
5123 	case DEV_SUSPEND:
5124 	case DEV_RESUME:
5125 	case DEV_SET_DRIVER:
5126 		error = priv_check(td, PRIV_DRIVER);
5127 		if (error == 0)
5128 			error = find_device(req, &dev);
5129 		break;
5130 	default:
5131 		error = ENOTTY;
5132 		break;
5133 	}
5134 	if (error) {
5135 		mtx_unlock(&Giant);
5136 		return (error);
5137 	}
5138 
5139 	/* Perform the requested operation. */
5140 	switch (cmd) {
5141 	case DEV_ATTACH:
5142 		if (device_is_attached(dev) && (dev->flags & DF_REBID) == 0)
5143 			error = EBUSY;
5144 		else if (!device_is_enabled(dev))
5145 			error = ENXIO;
5146 		else
5147 			error = device_probe_and_attach(dev);
5148 		break;
5149 	case DEV_DETACH:
5150 		if (!device_is_attached(dev)) {
5151 			error = ENXIO;
5152 			break;
5153 		}
5154 		if (!(req->dr_flags & DEVF_FORCE_DETACH)) {
5155 			error = device_quiesce(dev);
5156 			if (error)
5157 				break;
5158 		}
5159 		error = device_detach(dev);
5160 		break;
5161 	case DEV_ENABLE:
5162 		if (device_is_enabled(dev)) {
5163 			error = EBUSY;
5164 			break;
5165 		}
5166 
5167 		/*
5168 		 * If the device has been probed but not attached (e.g.
5169 		 * when it has been disabled by a loader hint), just
5170 		 * attach the device rather than doing a full probe.
5171 		 */
5172 		device_enable(dev);
5173 		if (device_is_alive(dev)) {
5174 			/*
5175 			 * If the device was disabled via a hint, clear
5176 			 * the hint.
5177 			 */
5178 			if (resource_disabled(dev->driver->name, dev->unit))
5179 				resource_unset_value(dev->driver->name,
5180 				    dev->unit, "disabled");
5181 			error = device_attach(dev);
5182 		} else
5183 			error = device_probe_and_attach(dev);
5184 		break;
5185 	case DEV_DISABLE:
5186 		if (!device_is_enabled(dev)) {
5187 			error = ENXIO;
5188 			break;
5189 		}
5190 
5191 		if (!(req->dr_flags & DEVF_FORCE_DETACH)) {
5192 			error = device_quiesce(dev);
5193 			if (error)
5194 				break;
5195 		}
5196 
5197 		/*
5198 		 * Force DF_FIXEDCLASS on around detach to preserve
5199 		 * the existing name.
5200 		 */
5201 		old = dev->flags;
5202 		dev->flags |= DF_FIXEDCLASS;
5203 		error = device_detach(dev);
5204 		if (!(old & DF_FIXEDCLASS))
5205 			dev->flags &= ~DF_FIXEDCLASS;
5206 		if (error == 0)
5207 			device_disable(dev);
5208 		break;
5209 	case DEV_SUSPEND:
5210 		if (device_is_suspended(dev)) {
5211 			error = EBUSY;
5212 			break;
5213 		}
5214 		if (device_get_parent(dev) == NULL) {
5215 			error = EINVAL;
5216 			break;
5217 		}
5218 		error = BUS_SUSPEND_CHILD(device_get_parent(dev), dev);
5219 		break;
5220 	case DEV_RESUME:
5221 		if (!device_is_suspended(dev)) {
5222 			error = EINVAL;
5223 			break;
5224 		}
5225 		if (device_get_parent(dev) == NULL) {
5226 			error = EINVAL;
5227 			break;
5228 		}
5229 		error = BUS_RESUME_CHILD(device_get_parent(dev), dev);
5230 		break;
5231 	case DEV_SET_DRIVER: {
5232 		devclass_t dc;
5233 		char driver[128];
5234 
5235 		error = copyinstr(req->dr_data, driver, sizeof(driver), NULL);
5236 		if (error)
5237 			break;
5238 		if (driver[0] == '\0') {
5239 			error = EINVAL;
5240 			break;
5241 		}
5242 		if (dev->devclass != NULL &&
5243 		    strcmp(driver, dev->devclass->name) == 0)
5244 			/* XXX: Could possibly force DF_FIXEDCLASS on? */
5245 			break;
5246 
5247 		/*
5248 		 * Scan drivers for this device's bus looking for at
5249 		 * least one matching driver.
5250 		 */
5251 		if (dev->parent == NULL) {
5252 			error = EINVAL;
5253 			break;
5254 		}
5255 		if (!driver_exists(dev->parent, driver)) {
5256 			error = ENOENT;
5257 			break;
5258 		}
5259 		dc = devclass_create(driver);
5260 		if (dc == NULL) {
5261 			error = ENOMEM;
5262 			break;
5263 		}
5264 
5265 		/* Detach device if necessary. */
5266 		if (device_is_attached(dev)) {
5267 			if (req->dr_flags & DEVF_SET_DRIVER_DETACH)
5268 				error = device_detach(dev);
5269 			else
5270 				error = EBUSY;
5271 			if (error)
5272 				break;
5273 		}
5274 
5275 		/* Clear any previously-fixed device class and unit. */
5276 		if (dev->flags & DF_FIXEDCLASS)
5277 			devclass_delete_device(dev->devclass, dev);
5278 		dev->flags |= DF_WILDCARD;
5279 		dev->unit = -1;
5280 
5281 		/* Force the new device class. */
5282 		error = devclass_add_device(dc, dev);
5283 		if (error)
5284 			break;
5285 		dev->flags |= DF_FIXEDCLASS;
5286 		error = device_probe_and_attach(dev);
5287 		break;
5288 	}
5289 	}
5290 	mtx_unlock(&Giant);
5291 	return (error);
5292 }
5293 
5294 static struct cdevsw devctl2_cdevsw = {
5295 	.d_version =	D_VERSION,
5296 	.d_ioctl =	devctl2_ioctl,
5297 	.d_name =	"devctl2",
5298 };
5299 
5300 static void
5301 devctl2_init(void)
5302 {
5303 
5304 	make_dev_credf(MAKEDEV_ETERNAL, &devctl2_cdevsw, 0, NULL,
5305 	    UID_ROOT, GID_WHEEL, 0600, "devctl2");
5306 }
5307