xref: /freebsd/sys/kern/subr_bus.c (revision 43d55325406e96e37be661de52289c2592c82ec9)
1 /*-
2  * Copyright (c) 1997,1998,2003 Doug Rabson
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include "opt_bus.h"
31 #include "opt_random.h"
32 
33 #include <sys/param.h>
34 #include <sys/conf.h>
35 #include <sys/filio.h>
36 #include <sys/lock.h>
37 #include <sys/kernel.h>
38 #include <sys/kobj.h>
39 #include <sys/limits.h>
40 #include <sys/malloc.h>
41 #include <sys/module.h>
42 #include <sys/mutex.h>
43 #include <sys/poll.h>
44 #include <sys/proc.h>
45 #include <sys/condvar.h>
46 #include <sys/queue.h>
47 #include <machine/bus.h>
48 #include <sys/random.h>
49 #include <sys/rman.h>
50 #include <sys/selinfo.h>
51 #include <sys/signalvar.h>
52 #include <sys/sysctl.h>
53 #include <sys/systm.h>
54 #include <sys/uio.h>
55 #include <sys/bus.h>
56 #include <sys/interrupt.h>
57 #include <sys/cpuset.h>
58 
59 #include <net/vnet.h>
60 
61 #include <machine/cpu.h>
62 #include <machine/stdarg.h>
63 
64 #include <vm/uma.h>
65 
66 SYSCTL_NODE(_hw, OID_AUTO, bus, CTLFLAG_RW, NULL, NULL);
67 SYSCTL_ROOT_NODE(OID_AUTO, dev, CTLFLAG_RW, NULL, NULL);
68 
69 /*
70  * Used to attach drivers to devclasses.
71  */
72 typedef struct driverlink *driverlink_t;
73 struct driverlink {
74 	kobj_class_t	driver;
75 	TAILQ_ENTRY(driverlink) link;	/* list of drivers in devclass */
76 	int		pass;
77 	TAILQ_ENTRY(driverlink) passlink;
78 };
79 
80 /*
81  * Forward declarations
82  */
83 typedef TAILQ_HEAD(devclass_list, devclass) devclass_list_t;
84 typedef TAILQ_HEAD(driver_list, driverlink) driver_list_t;
85 typedef TAILQ_HEAD(device_list, device) device_list_t;
86 
87 struct devclass {
88 	TAILQ_ENTRY(devclass) link;
89 	devclass_t	parent;		/* parent in devclass hierarchy */
90 	driver_list_t	drivers;     /* bus devclasses store drivers for bus */
91 	char		*name;
92 	device_t	*devices;	/* array of devices indexed by unit */
93 	int		maxunit;	/* size of devices array */
94 	int		flags;
95 #define DC_HAS_CHILDREN		1
96 
97 	struct sysctl_ctx_list sysctl_ctx;
98 	struct sysctl_oid *sysctl_tree;
99 };
100 
101 /**
102  * @brief Implementation of device.
103  */
104 struct device {
105 	/*
106 	 * A device is a kernel object. The first field must be the
107 	 * current ops table for the object.
108 	 */
109 	KOBJ_FIELDS;
110 
111 	/*
112 	 * Device hierarchy.
113 	 */
114 	TAILQ_ENTRY(device)	link;	/**< list of devices in parent */
115 	TAILQ_ENTRY(device)	devlink; /**< global device list membership */
116 	device_t	parent;		/**< parent of this device  */
117 	device_list_t	children;	/**< list of child devices */
118 
119 	/*
120 	 * Details of this device.
121 	 */
122 	driver_t	*driver;	/**< current driver */
123 	devclass_t	devclass;	/**< current device class */
124 	int		unit;		/**< current unit number */
125 	char*		nameunit;	/**< name+unit e.g. foodev0 */
126 	char*		desc;		/**< driver specific description */
127 	int		busy;		/**< count of calls to device_busy() */
128 	device_state_t	state;		/**< current device state  */
129 	uint32_t	devflags;	/**< api level flags for device_get_flags() */
130 	u_int		flags;		/**< internal device flags  */
131 #define	DF_ENABLED	0x01		/* device should be probed/attached */
132 #define	DF_FIXEDCLASS	0x02		/* devclass specified at create time */
133 #define	DF_WILDCARD	0x04		/* unit was originally wildcard */
134 #define	DF_DESCMALLOCED	0x08		/* description was malloced */
135 #define	DF_QUIET	0x10		/* don't print verbose attach message */
136 #define	DF_DONENOMATCH	0x20		/* don't execute DEVICE_NOMATCH again */
137 #define	DF_EXTERNALSOFTC 0x40		/* softc not allocated by us */
138 #define	DF_REBID	0x80		/* Can rebid after attach */
139 #define	DF_SUSPENDED	0x100		/* Device is suspended. */
140 	u_int	order;			/**< order from device_add_child_ordered() */
141 	void	*ivars;			/**< instance variables  */
142 	void	*softc;			/**< current driver's variables  */
143 
144 	struct sysctl_ctx_list sysctl_ctx; /**< state for sysctl variables  */
145 	struct sysctl_oid *sysctl_tree;	/**< state for sysctl variables */
146 };
147 
148 static MALLOC_DEFINE(M_BUS, "bus", "Bus data structures");
149 static MALLOC_DEFINE(M_BUS_SC, "bus-sc", "Bus data structures, softc");
150 
151 #ifdef BUS_DEBUG
152 
153 static int bus_debug = 1;
154 SYSCTL_INT(_debug, OID_AUTO, bus_debug, CTLFLAG_RWTUN, &bus_debug, 0,
155     "Bus debug level");
156 
157 #define PDEBUG(a)	if (bus_debug) {printf("%s:%d: ", __func__, __LINE__), printf a; printf("\n");}
158 #define DEVICENAME(d)	((d)? device_get_name(d): "no device")
159 #define DRIVERNAME(d)	((d)? d->name : "no driver")
160 #define DEVCLANAME(d)	((d)? d->name : "no devclass")
161 
162 /**
163  * Produce the indenting, indent*2 spaces plus a '.' ahead of that to
164  * prevent syslog from deleting initial spaces
165  */
166 #define indentprintf(p)	do { int iJ; printf("."); for (iJ=0; iJ<indent; iJ++) printf("  "); printf p ; } while (0)
167 
168 static void print_device_short(device_t dev, int indent);
169 static void print_device(device_t dev, int indent);
170 void print_device_tree_short(device_t dev, int indent);
171 void print_device_tree(device_t dev, int indent);
172 static void print_driver_short(driver_t *driver, int indent);
173 static void print_driver(driver_t *driver, int indent);
174 static void print_driver_list(driver_list_t drivers, int indent);
175 static void print_devclass_short(devclass_t dc, int indent);
176 static void print_devclass(devclass_t dc, int indent);
177 void print_devclass_list_short(void);
178 void print_devclass_list(void);
179 
180 #else
181 /* Make the compiler ignore the function calls */
182 #define PDEBUG(a)			/* nop */
183 #define DEVICENAME(d)			/* nop */
184 #define DRIVERNAME(d)			/* nop */
185 #define DEVCLANAME(d)			/* nop */
186 
187 #define print_device_short(d,i)		/* nop */
188 #define print_device(d,i)		/* nop */
189 #define print_device_tree_short(d,i)	/* nop */
190 #define print_device_tree(d,i)		/* nop */
191 #define print_driver_short(d,i)		/* nop */
192 #define print_driver(d,i)		/* nop */
193 #define print_driver_list(d,i)		/* nop */
194 #define print_devclass_short(d,i)	/* nop */
195 #define print_devclass(d,i)		/* nop */
196 #define print_devclass_list_short()	/* nop */
197 #define print_devclass_list()		/* nop */
198 #endif
199 
200 /*
201  * dev sysctl tree
202  */
203 
204 enum {
205 	DEVCLASS_SYSCTL_PARENT,
206 };
207 
208 static int
209 devclass_sysctl_handler(SYSCTL_HANDLER_ARGS)
210 {
211 	devclass_t dc = (devclass_t)arg1;
212 	const char *value;
213 
214 	switch (arg2) {
215 	case DEVCLASS_SYSCTL_PARENT:
216 		value = dc->parent ? dc->parent->name : "";
217 		break;
218 	default:
219 		return (EINVAL);
220 	}
221 	return (SYSCTL_OUT(req, value, strlen(value)));
222 }
223 
224 static void
225 devclass_sysctl_init(devclass_t dc)
226 {
227 
228 	if (dc->sysctl_tree != NULL)
229 		return;
230 	sysctl_ctx_init(&dc->sysctl_ctx);
231 	dc->sysctl_tree = SYSCTL_ADD_NODE(&dc->sysctl_ctx,
232 	    SYSCTL_STATIC_CHILDREN(_dev), OID_AUTO, dc->name,
233 	    CTLFLAG_RD, NULL, "");
234 	SYSCTL_ADD_PROC(&dc->sysctl_ctx, SYSCTL_CHILDREN(dc->sysctl_tree),
235 	    OID_AUTO, "%parent", CTLTYPE_STRING | CTLFLAG_RD,
236 	    dc, DEVCLASS_SYSCTL_PARENT, devclass_sysctl_handler, "A",
237 	    "parent class");
238 }
239 
240 enum {
241 	DEVICE_SYSCTL_DESC,
242 	DEVICE_SYSCTL_DRIVER,
243 	DEVICE_SYSCTL_LOCATION,
244 	DEVICE_SYSCTL_PNPINFO,
245 	DEVICE_SYSCTL_PARENT,
246 };
247 
248 static int
249 device_sysctl_handler(SYSCTL_HANDLER_ARGS)
250 {
251 	device_t dev = (device_t)arg1;
252 	const char *value;
253 	char *buf;
254 	int error;
255 
256 	buf = NULL;
257 	switch (arg2) {
258 	case DEVICE_SYSCTL_DESC:
259 		value = dev->desc ? dev->desc : "";
260 		break;
261 	case DEVICE_SYSCTL_DRIVER:
262 		value = dev->driver ? dev->driver->name : "";
263 		break;
264 	case DEVICE_SYSCTL_LOCATION:
265 		value = buf = malloc(1024, M_BUS, M_WAITOK | M_ZERO);
266 		bus_child_location_str(dev, buf, 1024);
267 		break;
268 	case DEVICE_SYSCTL_PNPINFO:
269 		value = buf = malloc(1024, M_BUS, M_WAITOK | M_ZERO);
270 		bus_child_pnpinfo_str(dev, buf, 1024);
271 		break;
272 	case DEVICE_SYSCTL_PARENT:
273 		value = dev->parent ? dev->parent->nameunit : "";
274 		break;
275 	default:
276 		return (EINVAL);
277 	}
278 	error = SYSCTL_OUT(req, value, strlen(value));
279 	if (buf != NULL)
280 		free(buf, M_BUS);
281 	return (error);
282 }
283 
284 static void
285 device_sysctl_init(device_t dev)
286 {
287 	devclass_t dc = dev->devclass;
288 
289 	if (dev->sysctl_tree != NULL)
290 		return;
291 	devclass_sysctl_init(dc);
292 	sysctl_ctx_init(&dev->sysctl_ctx);
293 	dev->sysctl_tree = SYSCTL_ADD_NODE(&dev->sysctl_ctx,
294 	    SYSCTL_CHILDREN(dc->sysctl_tree), OID_AUTO,
295 	    dev->nameunit + strlen(dc->name),
296 	    CTLFLAG_RD, NULL, "");
297 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
298 	    OID_AUTO, "%desc", CTLTYPE_STRING | CTLFLAG_RD,
299 	    dev, DEVICE_SYSCTL_DESC, device_sysctl_handler, "A",
300 	    "device description");
301 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
302 	    OID_AUTO, "%driver", CTLTYPE_STRING | CTLFLAG_RD,
303 	    dev, DEVICE_SYSCTL_DRIVER, device_sysctl_handler, "A",
304 	    "device driver name");
305 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
306 	    OID_AUTO, "%location", CTLTYPE_STRING | CTLFLAG_RD,
307 	    dev, DEVICE_SYSCTL_LOCATION, device_sysctl_handler, "A",
308 	    "device location relative to parent");
309 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
310 	    OID_AUTO, "%pnpinfo", CTLTYPE_STRING | CTLFLAG_RD,
311 	    dev, DEVICE_SYSCTL_PNPINFO, device_sysctl_handler, "A",
312 	    "device identification");
313 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
314 	    OID_AUTO, "%parent", CTLTYPE_STRING | CTLFLAG_RD,
315 	    dev, DEVICE_SYSCTL_PARENT, device_sysctl_handler, "A",
316 	    "parent device");
317 }
318 
319 static void
320 device_sysctl_update(device_t dev)
321 {
322 	devclass_t dc = dev->devclass;
323 
324 	if (dev->sysctl_tree == NULL)
325 		return;
326 	sysctl_rename_oid(dev->sysctl_tree, dev->nameunit + strlen(dc->name));
327 }
328 
329 static void
330 device_sysctl_fini(device_t dev)
331 {
332 	if (dev->sysctl_tree == NULL)
333 		return;
334 	sysctl_ctx_free(&dev->sysctl_ctx);
335 	dev->sysctl_tree = NULL;
336 }
337 
338 /*
339  * /dev/devctl implementation
340  */
341 
342 /*
343  * This design allows only one reader for /dev/devctl.  This is not desirable
344  * in the long run, but will get a lot of hair out of this implementation.
345  * Maybe we should make this device a clonable device.
346  *
347  * Also note: we specifically do not attach a device to the device_t tree
348  * to avoid potential chicken and egg problems.  One could argue that all
349  * of this belongs to the root node.  One could also further argue that the
350  * sysctl interface that we have not might more properly be an ioctl
351  * interface, but at this stage of the game, I'm not inclined to rock that
352  * boat.
353  *
354  * I'm also not sure that the SIGIO support is done correctly or not, as
355  * I copied it from a driver that had SIGIO support that likely hasn't been
356  * tested since 3.4 or 2.2.8!
357  */
358 
359 /* Deprecated way to adjust queue length */
360 static int sysctl_devctl_disable(SYSCTL_HANDLER_ARGS);
361 SYSCTL_PROC(_hw_bus, OID_AUTO, devctl_disable, CTLTYPE_INT | CTLFLAG_RWTUN |
362     CTLFLAG_MPSAFE, NULL, 0, sysctl_devctl_disable, "I",
363     "devctl disable -- deprecated");
364 
365 #define DEVCTL_DEFAULT_QUEUE_LEN 1000
366 static int sysctl_devctl_queue(SYSCTL_HANDLER_ARGS);
367 static int devctl_queue_length = DEVCTL_DEFAULT_QUEUE_LEN;
368 SYSCTL_PROC(_hw_bus, OID_AUTO, devctl_queue, CTLTYPE_INT | CTLFLAG_RWTUN |
369     CTLFLAG_MPSAFE, NULL, 0, sysctl_devctl_queue, "I", "devctl queue length");
370 
371 static d_open_t		devopen;
372 static d_close_t	devclose;
373 static d_read_t		devread;
374 static d_ioctl_t	devioctl;
375 static d_poll_t		devpoll;
376 static d_kqfilter_t	devkqfilter;
377 
378 static struct cdevsw dev_cdevsw = {
379 	.d_version =	D_VERSION,
380 	.d_open =	devopen,
381 	.d_close =	devclose,
382 	.d_read =	devread,
383 	.d_ioctl =	devioctl,
384 	.d_poll =	devpoll,
385 	.d_kqfilter =	devkqfilter,
386 	.d_name =	"devctl",
387 };
388 
389 struct dev_event_info
390 {
391 	char *dei_data;
392 	TAILQ_ENTRY(dev_event_info) dei_link;
393 };
394 
395 TAILQ_HEAD(devq, dev_event_info);
396 
397 static struct dev_softc
398 {
399 	int	inuse;
400 	int	nonblock;
401 	int	queued;
402 	int	async;
403 	struct mtx mtx;
404 	struct cv cv;
405 	struct selinfo sel;
406 	struct devq devq;
407 	struct sigio *sigio;
408 } devsoftc;
409 
410 static void	filt_devctl_detach(struct knote *kn);
411 static int	filt_devctl_read(struct knote *kn, long hint);
412 
413 struct filterops devctl_rfiltops = {
414 	.f_isfd = 1,
415 	.f_detach = filt_devctl_detach,
416 	.f_event = filt_devctl_read,
417 };
418 
419 static struct cdev *devctl_dev;
420 
421 static void
422 devinit(void)
423 {
424 	devctl_dev = make_dev_credf(MAKEDEV_ETERNAL, &dev_cdevsw, 0, NULL,
425 	    UID_ROOT, GID_WHEEL, 0600, "devctl");
426 	mtx_init(&devsoftc.mtx, "dev mtx", "devd", MTX_DEF);
427 	cv_init(&devsoftc.cv, "dev cv");
428 	TAILQ_INIT(&devsoftc.devq);
429 	knlist_init_mtx(&devsoftc.sel.si_note, &devsoftc.mtx);
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 Set the devclass of a device
2647  * @see devclass_add_device().
2648  */
2649 int
2650 device_set_devclass(device_t dev, const char *classname)
2651 {
2652 	devclass_t dc;
2653 	int error;
2654 
2655 	if (!classname) {
2656 		if (dev->devclass)
2657 			devclass_delete_device(dev->devclass, dev);
2658 		return (0);
2659 	}
2660 
2661 	if (dev->devclass) {
2662 		printf("device_set_devclass: device class already set\n");
2663 		return (EINVAL);
2664 	}
2665 
2666 	dc = devclass_find_internal(classname, NULL, TRUE);
2667 	if (!dc)
2668 		return (ENOMEM);
2669 
2670 	error = devclass_add_device(dc, dev);
2671 
2672 	bus_data_generation_update();
2673 	return (error);
2674 }
2675 
2676 /**
2677  * @brief Set the driver of a device
2678  *
2679  * @retval 0		success
2680  * @retval EBUSY	the device already has a driver attached
2681  * @retval ENOMEM	a memory allocation failure occurred
2682  */
2683 int
2684 device_set_driver(device_t dev, driver_t *driver)
2685 {
2686 	if (dev->state >= DS_ATTACHED)
2687 		return (EBUSY);
2688 
2689 	if (dev->driver == driver)
2690 		return (0);
2691 
2692 	if (dev->softc && !(dev->flags & DF_EXTERNALSOFTC)) {
2693 		free(dev->softc, M_BUS_SC);
2694 		dev->softc = NULL;
2695 	}
2696 	device_set_desc(dev, NULL);
2697 	kobj_delete((kobj_t) dev, NULL);
2698 	dev->driver = driver;
2699 	if (driver) {
2700 		kobj_init((kobj_t) dev, (kobj_class_t) driver);
2701 		if (!(dev->flags & DF_EXTERNALSOFTC) && driver->size > 0) {
2702 			dev->softc = malloc(driver->size, M_BUS_SC,
2703 			    M_NOWAIT | M_ZERO);
2704 			if (!dev->softc) {
2705 				kobj_delete((kobj_t) dev, NULL);
2706 				kobj_init((kobj_t) dev, &null_class);
2707 				dev->driver = NULL;
2708 				return (ENOMEM);
2709 			}
2710 		}
2711 	} else {
2712 		kobj_init((kobj_t) dev, &null_class);
2713 	}
2714 
2715 	bus_data_generation_update();
2716 	return (0);
2717 }
2718 
2719 /**
2720  * @brief Probe a device, and return this status.
2721  *
2722  * This function is the core of the device autoconfiguration
2723  * system. Its purpose is to select a suitable driver for a device and
2724  * then call that driver to initialise the hardware appropriately. The
2725  * driver is selected by calling the DEVICE_PROBE() method of a set of
2726  * candidate drivers and then choosing the driver which returned the
2727  * best value. This driver is then attached to the device using
2728  * device_attach().
2729  *
2730  * The set of suitable drivers is taken from the list of drivers in
2731  * the parent device's devclass. If the device was originally created
2732  * with a specific class name (see device_add_child()), only drivers
2733  * with that name are probed, otherwise all drivers in the devclass
2734  * are probed. If no drivers return successful probe values in the
2735  * parent devclass, the search continues in the parent of that
2736  * devclass (see devclass_get_parent()) if any.
2737  *
2738  * @param dev		the device to initialise
2739  *
2740  * @retval 0		success
2741  * @retval ENXIO	no driver was found
2742  * @retval ENOMEM	memory allocation failure
2743  * @retval non-zero	some other unix error code
2744  * @retval -1		Device already attached
2745  */
2746 int
2747 device_probe(device_t dev)
2748 {
2749 	int error;
2750 
2751 	GIANT_REQUIRED;
2752 
2753 	if (dev->state >= DS_ALIVE && (dev->flags & DF_REBID) == 0)
2754 		return (-1);
2755 
2756 	if (!(dev->flags & DF_ENABLED)) {
2757 		if (bootverbose && device_get_name(dev) != NULL) {
2758 			device_print_prettyname(dev);
2759 			printf("not probed (disabled)\n");
2760 		}
2761 		return (-1);
2762 	}
2763 	if ((error = device_probe_child(dev->parent, dev)) != 0) {
2764 		if (bus_current_pass == BUS_PASS_DEFAULT &&
2765 		    !(dev->flags & DF_DONENOMATCH)) {
2766 			BUS_PROBE_NOMATCH(dev->parent, dev);
2767 			devnomatch(dev);
2768 			dev->flags |= DF_DONENOMATCH;
2769 		}
2770 		return (error);
2771 	}
2772 	return (0);
2773 }
2774 
2775 /**
2776  * @brief Probe a device and attach a driver if possible
2777  *
2778  * calls device_probe() and attaches if that was successful.
2779  */
2780 int
2781 device_probe_and_attach(device_t dev)
2782 {
2783 	int error;
2784 
2785 	GIANT_REQUIRED;
2786 
2787 	error = device_probe(dev);
2788 	if (error == -1)
2789 		return (0);
2790 	else if (error != 0)
2791 		return (error);
2792 
2793 	CURVNET_SET_QUIET(vnet0);
2794 	error = device_attach(dev);
2795 	CURVNET_RESTORE();
2796 	return error;
2797 }
2798 
2799 /**
2800  * @brief Attach a device driver to a device
2801  *
2802  * This function is a wrapper around the DEVICE_ATTACH() driver
2803  * method. In addition to calling DEVICE_ATTACH(), it initialises the
2804  * device's sysctl tree, optionally prints a description of the device
2805  * and queues a notification event for user-based device management
2806  * services.
2807  *
2808  * Normally this function is only called internally from
2809  * device_probe_and_attach().
2810  *
2811  * @param dev		the device to initialise
2812  *
2813  * @retval 0		success
2814  * @retval ENXIO	no driver was found
2815  * @retval ENOMEM	memory allocation failure
2816  * @retval non-zero	some other unix error code
2817  */
2818 int
2819 device_attach(device_t dev)
2820 {
2821 	uint64_t attachtime;
2822 	int error;
2823 
2824 	if (resource_disabled(dev->driver->name, dev->unit)) {
2825 		device_disable(dev);
2826 		if (bootverbose)
2827 			 device_printf(dev, "disabled via hints entry\n");
2828 		return (ENXIO);
2829 	}
2830 
2831 	device_sysctl_init(dev);
2832 	if (!device_is_quiet(dev))
2833 		device_print_child(dev->parent, dev);
2834 	attachtime = get_cyclecount();
2835 	dev->state = DS_ATTACHING;
2836 	if ((error = DEVICE_ATTACH(dev)) != 0) {
2837 		printf("device_attach: %s%d attach returned %d\n",
2838 		    dev->driver->name, dev->unit, error);
2839 		if (!(dev->flags & DF_FIXEDCLASS))
2840 			devclass_delete_device(dev->devclass, dev);
2841 		(void)device_set_driver(dev, NULL);
2842 		device_sysctl_fini(dev);
2843 		KASSERT(dev->busy == 0, ("attach failed but busy"));
2844 		dev->state = DS_NOTPRESENT;
2845 		return (error);
2846 	}
2847 	attachtime = get_cyclecount() - attachtime;
2848 	/*
2849 	 * 4 bits per device is a reasonable value for desktop and server
2850 	 * hardware with good get_cyclecount() implementations, but may
2851 	 * need to be adjusted on other platforms.
2852 	 */
2853 #ifdef RANDOM_DEBUG
2854 	printf("random: %s(): feeding %d bit(s) of entropy from %s%d\n",
2855 	    __func__, 4, dev->driver->name, dev->unit);
2856 #endif
2857 	random_harvest(&attachtime, sizeof(attachtime), 4, RANDOM_ATTACH);
2858 	device_sysctl_update(dev);
2859 	if (dev->busy)
2860 		dev->state = DS_BUSY;
2861 	else
2862 		dev->state = DS_ATTACHED;
2863 	dev->flags &= ~DF_DONENOMATCH;
2864 	devadded(dev);
2865 	return (0);
2866 }
2867 
2868 /**
2869  * @brief Detach a driver from a device
2870  *
2871  * This function is a wrapper around the DEVICE_DETACH() driver
2872  * method. If the call to DEVICE_DETACH() succeeds, it calls
2873  * BUS_CHILD_DETACHED() for the parent of @p dev, queues a
2874  * notification event for user-based device management services and
2875  * cleans up the device's sysctl tree.
2876  *
2877  * @param dev		the device to un-initialise
2878  *
2879  * @retval 0		success
2880  * @retval ENXIO	no driver was found
2881  * @retval ENOMEM	memory allocation failure
2882  * @retval non-zero	some other unix error code
2883  */
2884 int
2885 device_detach(device_t dev)
2886 {
2887 	int error;
2888 
2889 	GIANT_REQUIRED;
2890 
2891 	PDEBUG(("%s", DEVICENAME(dev)));
2892 	if (dev->state == DS_BUSY)
2893 		return (EBUSY);
2894 	if (dev->state != DS_ATTACHED)
2895 		return (0);
2896 
2897 	if ((error = DEVICE_DETACH(dev)) != 0)
2898 		return (error);
2899 	devremoved(dev);
2900 	if (!device_is_quiet(dev))
2901 		device_printf(dev, "detached\n");
2902 	if (dev->parent)
2903 		BUS_CHILD_DETACHED(dev->parent, dev);
2904 
2905 	if (!(dev->flags & DF_FIXEDCLASS))
2906 		devclass_delete_device(dev->devclass, dev);
2907 
2908 	dev->state = DS_NOTPRESENT;
2909 	(void)device_set_driver(dev, NULL);
2910 	device_sysctl_fini(dev);
2911 
2912 	return (0);
2913 }
2914 
2915 /**
2916  * @brief Tells a driver to quiesce itself.
2917  *
2918  * This function is a wrapper around the DEVICE_QUIESCE() driver
2919  * method. If the call to DEVICE_QUIESCE() succeeds.
2920  *
2921  * @param dev		the device to quiesce
2922  *
2923  * @retval 0		success
2924  * @retval ENXIO	no driver was found
2925  * @retval ENOMEM	memory allocation failure
2926  * @retval non-zero	some other unix error code
2927  */
2928 int
2929 device_quiesce(device_t dev)
2930 {
2931 
2932 	PDEBUG(("%s", DEVICENAME(dev)));
2933 	if (dev->state == DS_BUSY)
2934 		return (EBUSY);
2935 	if (dev->state != DS_ATTACHED)
2936 		return (0);
2937 
2938 	return (DEVICE_QUIESCE(dev));
2939 }
2940 
2941 /**
2942  * @brief Notify a device of system shutdown
2943  *
2944  * This function calls the DEVICE_SHUTDOWN() driver method if the
2945  * device currently has an attached driver.
2946  *
2947  * @returns the value returned by DEVICE_SHUTDOWN()
2948  */
2949 int
2950 device_shutdown(device_t dev)
2951 {
2952 	if (dev->state < DS_ATTACHED)
2953 		return (0);
2954 	return (DEVICE_SHUTDOWN(dev));
2955 }
2956 
2957 /**
2958  * @brief Set the unit number of a device
2959  *
2960  * This function can be used to override the unit number used for a
2961  * device (e.g. to wire a device to a pre-configured unit number).
2962  */
2963 int
2964 device_set_unit(device_t dev, int unit)
2965 {
2966 	devclass_t dc;
2967 	int err;
2968 
2969 	dc = device_get_devclass(dev);
2970 	if (unit < dc->maxunit && dc->devices[unit])
2971 		return (EBUSY);
2972 	err = devclass_delete_device(dc, dev);
2973 	if (err)
2974 		return (err);
2975 	dev->unit = unit;
2976 	err = devclass_add_device(dc, dev);
2977 	if (err)
2978 		return (err);
2979 
2980 	bus_data_generation_update();
2981 	return (0);
2982 }
2983 
2984 /*======================================*/
2985 /*
2986  * Some useful method implementations to make life easier for bus drivers.
2987  */
2988 
2989 /**
2990  * @brief Initialise a resource list.
2991  *
2992  * @param rl		the resource list to initialise
2993  */
2994 void
2995 resource_list_init(struct resource_list *rl)
2996 {
2997 	STAILQ_INIT(rl);
2998 }
2999 
3000 /**
3001  * @brief Reclaim memory used by a resource list.
3002  *
3003  * This function frees the memory for all resource entries on the list
3004  * (if any).
3005  *
3006  * @param rl		the resource list to free
3007  */
3008 void
3009 resource_list_free(struct resource_list *rl)
3010 {
3011 	struct resource_list_entry *rle;
3012 
3013 	while ((rle = STAILQ_FIRST(rl)) != NULL) {
3014 		if (rle->res)
3015 			panic("resource_list_free: resource entry is busy");
3016 		STAILQ_REMOVE_HEAD(rl, link);
3017 		free(rle, M_BUS);
3018 	}
3019 }
3020 
3021 /**
3022  * @brief Add a resource entry.
3023  *
3024  * This function adds a resource entry using the given @p type, @p
3025  * start, @p end and @p count values. A rid value is chosen by
3026  * searching sequentially for the first unused rid starting at zero.
3027  *
3028  * @param rl		the resource list to edit
3029  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
3030  * @param start		the start address of the resource
3031  * @param end		the end address of the resource
3032  * @param count		XXX end-start+1
3033  */
3034 int
3035 resource_list_add_next(struct resource_list *rl, int type, u_long start,
3036     u_long end, u_long count)
3037 {
3038 	int rid;
3039 
3040 	rid = 0;
3041 	while (resource_list_find(rl, type, rid) != NULL)
3042 		rid++;
3043 	resource_list_add(rl, type, rid, start, end, count);
3044 	return (rid);
3045 }
3046 
3047 /**
3048  * @brief Add or modify a resource entry.
3049  *
3050  * If an existing entry exists with the same type and rid, it will be
3051  * modified using the given values of @p start, @p end and @p
3052  * count. If no entry exists, a new one will be created using the
3053  * given values.  The resource list entry that matches is then returned.
3054  *
3055  * @param rl		the resource list to edit
3056  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
3057  * @param rid		the resource identifier
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 struct resource_list_entry *
3063 resource_list_add(struct resource_list *rl, int type, int rid,
3064     u_long start, u_long end, u_long count)
3065 {
3066 	struct resource_list_entry *rle;
3067 
3068 	rle = resource_list_find(rl, type, rid);
3069 	if (!rle) {
3070 		rle = malloc(sizeof(struct resource_list_entry), M_BUS,
3071 		    M_NOWAIT);
3072 		if (!rle)
3073 			panic("resource_list_add: can't record entry");
3074 		STAILQ_INSERT_TAIL(rl, rle, link);
3075 		rle->type = type;
3076 		rle->rid = rid;
3077 		rle->res = NULL;
3078 		rle->flags = 0;
3079 	}
3080 
3081 	if (rle->res)
3082 		panic("resource_list_add: resource entry is busy");
3083 
3084 	rle->start = start;
3085 	rle->end = end;
3086 	rle->count = count;
3087 	return (rle);
3088 }
3089 
3090 /**
3091  * @brief Determine if a resource entry is busy.
3092  *
3093  * Returns true if a resource entry is busy meaning that it has an
3094  * associated resource that is not an unallocated "reserved" resource.
3095  *
3096  * @param rl		the resource list to search
3097  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
3098  * @param rid		the resource identifier
3099  *
3100  * @returns Non-zero if the entry is busy, zero otherwise.
3101  */
3102 int
3103 resource_list_busy(struct resource_list *rl, int type, int rid)
3104 {
3105 	struct resource_list_entry *rle;
3106 
3107 	rle = resource_list_find(rl, type, rid);
3108 	if (rle == NULL || rle->res == NULL)
3109 		return (0);
3110 	if ((rle->flags & (RLE_RESERVED | RLE_ALLOCATED)) == RLE_RESERVED) {
3111 		KASSERT(!(rman_get_flags(rle->res) & RF_ACTIVE),
3112 		    ("reserved resource is active"));
3113 		return (0);
3114 	}
3115 	return (1);
3116 }
3117 
3118 /**
3119  * @brief Determine if a resource entry is reserved.
3120  *
3121  * Returns true if a resource entry is reserved meaning that it has an
3122  * associated "reserved" resource.  The resource can either be
3123  * allocated or unallocated.
3124  *
3125  * @param rl		the resource list to search
3126  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
3127  * @param rid		the resource identifier
3128  *
3129  * @returns Non-zero if the entry is reserved, zero otherwise.
3130  */
3131 int
3132 resource_list_reserved(struct resource_list *rl, int type, int rid)
3133 {
3134 	struct resource_list_entry *rle;
3135 
3136 	rle = resource_list_find(rl, type, rid);
3137 	if (rle != NULL && rle->flags & RLE_RESERVED)
3138 		return (1);
3139 	return (0);
3140 }
3141 
3142 /**
3143  * @brief Find a resource entry by type and rid.
3144  *
3145  * @param rl		the resource list to search
3146  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
3147  * @param rid		the resource identifier
3148  *
3149  * @returns the resource entry pointer or NULL if there is no such
3150  * entry.
3151  */
3152 struct resource_list_entry *
3153 resource_list_find(struct resource_list *rl, int type, int rid)
3154 {
3155 	struct resource_list_entry *rle;
3156 
3157 	STAILQ_FOREACH(rle, rl, link) {
3158 		if (rle->type == type && rle->rid == rid)
3159 			return (rle);
3160 	}
3161 	return (NULL);
3162 }
3163 
3164 /**
3165  * @brief Delete a resource entry.
3166  *
3167  * @param rl		the resource list to edit
3168  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
3169  * @param rid		the resource identifier
3170  */
3171 void
3172 resource_list_delete(struct resource_list *rl, int type, int rid)
3173 {
3174 	struct resource_list_entry *rle = resource_list_find(rl, type, rid);
3175 
3176 	if (rle) {
3177 		if (rle->res != NULL)
3178 			panic("resource_list_delete: resource has not been released");
3179 		STAILQ_REMOVE(rl, rle, resource_list_entry, link);
3180 		free(rle, M_BUS);
3181 	}
3182 }
3183 
3184 /**
3185  * @brief Allocate a reserved resource
3186  *
3187  * This can be used by busses to force the allocation of resources
3188  * that are always active in the system even if they are not allocated
3189  * by a driver (e.g. PCI BARs).  This function is usually called when
3190  * adding a new child to the bus.  The resource is allocated from the
3191  * parent bus when it is reserved.  The resource list entry is marked
3192  * with RLE_RESERVED to note that it is a reserved resource.
3193  *
3194  * Subsequent attempts to allocate the resource with
3195  * resource_list_alloc() will succeed the first time and will set
3196  * RLE_ALLOCATED to note that it has been allocated.  When a reserved
3197  * resource that has been allocated is released with
3198  * resource_list_release() the resource RLE_ALLOCATED is cleared, but
3199  * the actual resource remains allocated.  The resource can be released to
3200  * the parent bus by calling resource_list_unreserve().
3201  *
3202  * @param rl		the resource list to allocate from
3203  * @param bus		the parent device of @p child
3204  * @param child		the device for which the resource is being reserved
3205  * @param type		the type of resource to allocate
3206  * @param rid		a pointer to the resource identifier
3207  * @param start		hint at the start of the resource range - pass
3208  *			@c 0UL for any start address
3209  * @param end		hint at the end of the resource range - pass
3210  *			@c ~0UL for any end address
3211  * @param count		hint at the size of range required - pass @c 1
3212  *			for any size
3213  * @param flags		any extra flags to control the resource
3214  *			allocation - see @c RF_XXX flags in
3215  *			<sys/rman.h> for details
3216  *
3217  * @returns		the resource which was allocated or @c NULL if no
3218  *			resource could be allocated
3219  */
3220 struct resource *
3221 resource_list_reserve(struct resource_list *rl, device_t bus, device_t child,
3222     int type, int *rid, u_long start, u_long end, u_long count, u_int flags)
3223 {
3224 	struct resource_list_entry *rle = NULL;
3225 	int passthrough = (device_get_parent(child) != bus);
3226 	struct resource *r;
3227 
3228 	if (passthrough)
3229 		panic(
3230     "resource_list_reserve() should only be called for direct children");
3231 	if (flags & RF_ACTIVE)
3232 		panic(
3233     "resource_list_reserve() should only reserve inactive resources");
3234 
3235 	r = resource_list_alloc(rl, bus, child, type, rid, start, end, count,
3236 	    flags);
3237 	if (r != NULL) {
3238 		rle = resource_list_find(rl, type, *rid);
3239 		rle->flags |= RLE_RESERVED;
3240 	}
3241 	return (r);
3242 }
3243 
3244 /**
3245  * @brief Helper function for implementing BUS_ALLOC_RESOURCE()
3246  *
3247  * Implement BUS_ALLOC_RESOURCE() by looking up a resource from the list
3248  * and passing the allocation up to the parent of @p bus. This assumes
3249  * that the first entry of @c device_get_ivars(child) is a struct
3250  * resource_list. This also handles 'passthrough' allocations where a
3251  * child is a remote descendant of bus by passing the allocation up to
3252  * the parent of bus.
3253  *
3254  * Typically, a bus driver would store a list of child resources
3255  * somewhere in the child device's ivars (see device_get_ivars()) and
3256  * its implementation of BUS_ALLOC_RESOURCE() would find that list and
3257  * then call resource_list_alloc() to perform the allocation.
3258  *
3259  * @param rl		the resource list to allocate from
3260  * @param bus		the parent device of @p child
3261  * @param child		the device which is requesting an allocation
3262  * @param type		the type of resource to allocate
3263  * @param rid		a pointer to the resource identifier
3264  * @param start		hint at the start of the resource range - pass
3265  *			@c 0UL for any start address
3266  * @param end		hint at the end of the resource range - pass
3267  *			@c ~0UL for any end address
3268  * @param count		hint at the size of range required - pass @c 1
3269  *			for any size
3270  * @param flags		any extra flags to control the resource
3271  *			allocation - see @c RF_XXX flags in
3272  *			<sys/rman.h> for details
3273  *
3274  * @returns		the resource which was allocated or @c NULL if no
3275  *			resource could be allocated
3276  */
3277 struct resource *
3278 resource_list_alloc(struct resource_list *rl, device_t bus, device_t child,
3279     int type, int *rid, u_long start, u_long end, u_long count, u_int flags)
3280 {
3281 	struct resource_list_entry *rle = NULL;
3282 	int passthrough = (device_get_parent(child) != bus);
3283 	int isdefault = (start == 0UL && end == ~0UL);
3284 
3285 	if (passthrough) {
3286 		return (BUS_ALLOC_RESOURCE(device_get_parent(bus), child,
3287 		    type, rid, start, end, count, flags));
3288 	}
3289 
3290 	rle = resource_list_find(rl, type, *rid);
3291 
3292 	if (!rle)
3293 		return (NULL);		/* no resource of that type/rid */
3294 
3295 	if (rle->res) {
3296 		if (rle->flags & RLE_RESERVED) {
3297 			if (rle->flags & RLE_ALLOCATED)
3298 				return (NULL);
3299 			if ((flags & RF_ACTIVE) &&
3300 			    bus_activate_resource(child, type, *rid,
3301 			    rle->res) != 0)
3302 				return (NULL);
3303 			rle->flags |= RLE_ALLOCATED;
3304 			return (rle->res);
3305 		}
3306 		device_printf(bus,
3307 		    "resource entry %#x type %d for child %s is busy\n", *rid,
3308 		    type, device_get_nameunit(child));
3309 		return (NULL);
3310 	}
3311 
3312 	if (isdefault) {
3313 		start = rle->start;
3314 		count = ulmax(count, rle->count);
3315 		end = ulmax(rle->end, start + count - 1);
3316 	}
3317 
3318 	rle->res = BUS_ALLOC_RESOURCE(device_get_parent(bus), child,
3319 	    type, rid, start, end, count, flags);
3320 
3321 	/*
3322 	 * Record the new range.
3323 	 */
3324 	if (rle->res) {
3325 		rle->start = rman_get_start(rle->res);
3326 		rle->end = rman_get_end(rle->res);
3327 		rle->count = count;
3328 	}
3329 
3330 	return (rle->res);
3331 }
3332 
3333 /**
3334  * @brief Helper function for implementing BUS_RELEASE_RESOURCE()
3335  *
3336  * Implement BUS_RELEASE_RESOURCE() using a resource list. Normally
3337  * used with resource_list_alloc().
3338  *
3339  * @param rl		the resource list which was allocated from
3340  * @param bus		the parent device of @p child
3341  * @param child		the device which is requesting a release
3342  * @param type		the type of resource to release
3343  * @param rid		the resource identifier
3344  * @param res		the resource to release
3345  *
3346  * @retval 0		success
3347  * @retval non-zero	a standard unix error code indicating what
3348  *			error condition prevented the operation
3349  */
3350 int
3351 resource_list_release(struct resource_list *rl, device_t bus, device_t child,
3352     int type, int rid, struct resource *res)
3353 {
3354 	struct resource_list_entry *rle = NULL;
3355 	int passthrough = (device_get_parent(child) != bus);
3356 	int error;
3357 
3358 	if (passthrough) {
3359 		return (BUS_RELEASE_RESOURCE(device_get_parent(bus), child,
3360 		    type, rid, res));
3361 	}
3362 
3363 	rle = resource_list_find(rl, type, rid);
3364 
3365 	if (!rle)
3366 		panic("resource_list_release: can't find resource");
3367 	if (!rle->res)
3368 		panic("resource_list_release: resource entry is not busy");
3369 	if (rle->flags & RLE_RESERVED) {
3370 		if (rle->flags & RLE_ALLOCATED) {
3371 			if (rman_get_flags(res) & RF_ACTIVE) {
3372 				error = bus_deactivate_resource(child, type,
3373 				    rid, res);
3374 				if (error)
3375 					return (error);
3376 			}
3377 			rle->flags &= ~RLE_ALLOCATED;
3378 			return (0);
3379 		}
3380 		return (EINVAL);
3381 	}
3382 
3383 	error = BUS_RELEASE_RESOURCE(device_get_parent(bus), child,
3384 	    type, rid, res);
3385 	if (error)
3386 		return (error);
3387 
3388 	rle->res = NULL;
3389 	return (0);
3390 }
3391 
3392 /**
3393  * @brief Release all active resources of a given type
3394  *
3395  * Release all active resources of a specified type.  This is intended
3396  * to be used to cleanup resources leaked by a driver after detach or
3397  * a failed attach.
3398  *
3399  * @param rl		the resource list which was allocated from
3400  * @param bus		the parent device of @p child
3401  * @param child		the device whose active resources are being released
3402  * @param type		the type of resources to release
3403  *
3404  * @retval 0		success
3405  * @retval EBUSY	at least one resource was active
3406  */
3407 int
3408 resource_list_release_active(struct resource_list *rl, device_t bus,
3409     device_t child, int type)
3410 {
3411 	struct resource_list_entry *rle;
3412 	int error, retval;
3413 
3414 	retval = 0;
3415 	STAILQ_FOREACH(rle, rl, link) {
3416 		if (rle->type != type)
3417 			continue;
3418 		if (rle->res == NULL)
3419 			continue;
3420 		if ((rle->flags & (RLE_RESERVED | RLE_ALLOCATED)) ==
3421 		    RLE_RESERVED)
3422 			continue;
3423 		retval = EBUSY;
3424 		error = resource_list_release(rl, bus, child, type,
3425 		    rman_get_rid(rle->res), rle->res);
3426 		if (error != 0)
3427 			device_printf(bus,
3428 			    "Failed to release active resource: %d\n", error);
3429 	}
3430 	return (retval);
3431 }
3432 
3433 
3434 /**
3435  * @brief Fully release a reserved resource
3436  *
3437  * Fully releases a resource reserved via resource_list_reserve().
3438  *
3439  * @param rl		the resource list which was allocated from
3440  * @param bus		the parent device of @p child
3441  * @param child		the device whose reserved resource is being released
3442  * @param type		the type of resource to release
3443  * @param rid		the resource identifier
3444  * @param res		the resource to release
3445  *
3446  * @retval 0		success
3447  * @retval non-zero	a standard unix error code indicating what
3448  *			error condition prevented the operation
3449  */
3450 int
3451 resource_list_unreserve(struct resource_list *rl, device_t bus, device_t child,
3452     int type, int rid)
3453 {
3454 	struct resource_list_entry *rle = NULL;
3455 	int passthrough = (device_get_parent(child) != bus);
3456 
3457 	if (passthrough)
3458 		panic(
3459     "resource_list_unreserve() should only be called for direct children");
3460 
3461 	rle = resource_list_find(rl, type, rid);
3462 
3463 	if (!rle)
3464 		panic("resource_list_unreserve: can't find resource");
3465 	if (!(rle->flags & RLE_RESERVED))
3466 		return (EINVAL);
3467 	if (rle->flags & RLE_ALLOCATED)
3468 		return (EBUSY);
3469 	rle->flags &= ~RLE_RESERVED;
3470 	return (resource_list_release(rl, bus, child, type, rid, rle->res));
3471 }
3472 
3473 /**
3474  * @brief Print a description of resources in a resource list
3475  *
3476  * Print all resources of a specified type, for use in BUS_PRINT_CHILD().
3477  * The name is printed if at least one resource of the given type is available.
3478  * The format is used to print resource start and end.
3479  *
3480  * @param rl		the resource list to print
3481  * @param name		the name of @p type, e.g. @c "memory"
3482  * @param type		type type of resource entry to print
3483  * @param format	printf(9) format string to print resource
3484  *			start and end values
3485  *
3486  * @returns		the number of characters printed
3487  */
3488 int
3489 resource_list_print_type(struct resource_list *rl, const char *name, int type,
3490     const char *format)
3491 {
3492 	struct resource_list_entry *rle;
3493 	int printed, retval;
3494 
3495 	printed = 0;
3496 	retval = 0;
3497 	/* Yes, this is kinda cheating */
3498 	STAILQ_FOREACH(rle, rl, link) {
3499 		if (rle->type == type) {
3500 			if (printed == 0)
3501 				retval += printf(" %s ", name);
3502 			else
3503 				retval += printf(",");
3504 			printed++;
3505 			retval += printf(format, rle->start);
3506 			if (rle->count > 1) {
3507 				retval += printf("-");
3508 				retval += printf(format, rle->start +
3509 						 rle->count - 1);
3510 			}
3511 		}
3512 	}
3513 	return (retval);
3514 }
3515 
3516 /**
3517  * @brief Releases all the resources in a list.
3518  *
3519  * @param rl		The resource list to purge.
3520  *
3521  * @returns		nothing
3522  */
3523 void
3524 resource_list_purge(struct resource_list *rl)
3525 {
3526 	struct resource_list_entry *rle;
3527 
3528 	while ((rle = STAILQ_FIRST(rl)) != NULL) {
3529 		if (rle->res)
3530 			bus_release_resource(rman_get_device(rle->res),
3531 			    rle->type, rle->rid, rle->res);
3532 		STAILQ_REMOVE_HEAD(rl, link);
3533 		free(rle, M_BUS);
3534 	}
3535 }
3536 
3537 device_t
3538 bus_generic_add_child(device_t dev, u_int order, const char *name, int unit)
3539 {
3540 
3541 	return (device_add_child_ordered(dev, order, name, unit));
3542 }
3543 
3544 /**
3545  * @brief Helper function for implementing DEVICE_PROBE()
3546  *
3547  * This function can be used to help implement the DEVICE_PROBE() for
3548  * a bus (i.e. a device which has other devices attached to it). It
3549  * calls the DEVICE_IDENTIFY() method of each driver in the device's
3550  * devclass.
3551  */
3552 int
3553 bus_generic_probe(device_t dev)
3554 {
3555 	devclass_t dc = dev->devclass;
3556 	driverlink_t dl;
3557 
3558 	TAILQ_FOREACH(dl, &dc->drivers, link) {
3559 		/*
3560 		 * If this driver's pass is too high, then ignore it.
3561 		 * For most drivers in the default pass, this will
3562 		 * never be true.  For early-pass drivers they will
3563 		 * only call the identify routines of eligible drivers
3564 		 * when this routine is called.  Drivers for later
3565 		 * passes should have their identify routines called
3566 		 * on early-pass busses during BUS_NEW_PASS().
3567 		 */
3568 		if (dl->pass > bus_current_pass)
3569 			continue;
3570 		DEVICE_IDENTIFY(dl->driver, dev);
3571 	}
3572 
3573 	return (0);
3574 }
3575 
3576 /**
3577  * @brief Helper function for implementing DEVICE_ATTACH()
3578  *
3579  * This function can be used to help implement the DEVICE_ATTACH() for
3580  * a bus. It calls device_probe_and_attach() for each of the device's
3581  * children.
3582  */
3583 int
3584 bus_generic_attach(device_t dev)
3585 {
3586 	device_t child;
3587 
3588 	TAILQ_FOREACH(child, &dev->children, link) {
3589 		device_probe_and_attach(child);
3590 	}
3591 
3592 	return (0);
3593 }
3594 
3595 /**
3596  * @brief Helper function for implementing DEVICE_DETACH()
3597  *
3598  * This function can be used to help implement the DEVICE_DETACH() for
3599  * a bus. It calls device_detach() for each of the device's
3600  * children.
3601  */
3602 int
3603 bus_generic_detach(device_t dev)
3604 {
3605 	device_t child;
3606 	int error;
3607 
3608 	if (dev->state != DS_ATTACHED)
3609 		return (EBUSY);
3610 
3611 	TAILQ_FOREACH(child, &dev->children, link) {
3612 		if ((error = device_detach(child)) != 0)
3613 			return (error);
3614 	}
3615 
3616 	return (0);
3617 }
3618 
3619 /**
3620  * @brief Helper function for implementing DEVICE_SHUTDOWN()
3621  *
3622  * This function can be used to help implement the DEVICE_SHUTDOWN()
3623  * for a bus. It calls device_shutdown() for each of the device's
3624  * children.
3625  */
3626 int
3627 bus_generic_shutdown(device_t dev)
3628 {
3629 	device_t child;
3630 
3631 	TAILQ_FOREACH(child, &dev->children, link) {
3632 		device_shutdown(child);
3633 	}
3634 
3635 	return (0);
3636 }
3637 
3638 /**
3639  * @brief Default function for suspending a child device.
3640  *
3641  * This function is to be used by a bus's DEVICE_SUSPEND_CHILD().
3642  */
3643 int
3644 bus_generic_suspend_child(device_t dev, device_t child)
3645 {
3646 	int	error;
3647 
3648 	error = DEVICE_SUSPEND(child);
3649 
3650 	if (error == 0)
3651 		dev->flags |= DF_SUSPENDED;
3652 
3653 	return (error);
3654 }
3655 
3656 /**
3657  * @brief Default function for resuming a child device.
3658  *
3659  * This function is to be used by a bus's DEVICE_RESUME_CHILD().
3660  */
3661 int
3662 bus_generic_resume_child(device_t dev, device_t child)
3663 {
3664 
3665 	DEVICE_RESUME(child);
3666 	dev->flags &= ~DF_SUSPENDED;
3667 
3668 	return (0);
3669 }
3670 
3671 /**
3672  * @brief Helper function for implementing DEVICE_SUSPEND()
3673  *
3674  * This function can be used to help implement the DEVICE_SUSPEND()
3675  * for a bus. It calls DEVICE_SUSPEND() for each of the device's
3676  * children. If any call to DEVICE_SUSPEND() fails, the suspend
3677  * operation is aborted and any devices which were suspended are
3678  * resumed immediately by calling their DEVICE_RESUME() methods.
3679  */
3680 int
3681 bus_generic_suspend(device_t dev)
3682 {
3683 	int		error;
3684 	device_t	child, child2;
3685 
3686 	TAILQ_FOREACH(child, &dev->children, link) {
3687 		error = BUS_SUSPEND_CHILD(dev, child);
3688 		if (error) {
3689 			for (child2 = TAILQ_FIRST(&dev->children);
3690 			     child2 && child2 != child;
3691 			     child2 = TAILQ_NEXT(child2, link))
3692 				BUS_RESUME_CHILD(dev, child2);
3693 			return (error);
3694 		}
3695 	}
3696 	return (0);
3697 }
3698 
3699 /**
3700  * @brief Helper function for implementing DEVICE_RESUME()
3701  *
3702  * This function can be used to help implement the DEVICE_RESUME() for
3703  * a bus. It calls DEVICE_RESUME() on each of the device's children.
3704  */
3705 int
3706 bus_generic_resume(device_t dev)
3707 {
3708 	device_t	child;
3709 
3710 	TAILQ_FOREACH(child, &dev->children, link) {
3711 		BUS_RESUME_CHILD(dev, child);
3712 		/* if resume fails, there's nothing we can usefully do... */
3713 	}
3714 	return (0);
3715 }
3716 
3717 /**
3718  * @brief Helper function for implementing BUS_PRINT_CHILD().
3719  *
3720  * This function prints the first part of the ascii representation of
3721  * @p child, including its name, unit and description (if any - see
3722  * device_set_desc()).
3723  *
3724  * @returns the number of characters printed
3725  */
3726 int
3727 bus_print_child_header(device_t dev, device_t child)
3728 {
3729 	int	retval = 0;
3730 
3731 	if (device_get_desc(child)) {
3732 		retval += device_printf(child, "<%s>", device_get_desc(child));
3733 	} else {
3734 		retval += printf("%s", device_get_nameunit(child));
3735 	}
3736 
3737 	return (retval);
3738 }
3739 
3740 /**
3741  * @brief Helper function for implementing BUS_PRINT_CHILD().
3742  *
3743  * This function prints the last part of the ascii representation of
3744  * @p child, which consists of the string @c " on " followed by the
3745  * name and unit of the @p dev.
3746  *
3747  * @returns the number of characters printed
3748  */
3749 int
3750 bus_print_child_footer(device_t dev, device_t child)
3751 {
3752 	return (printf(" on %s\n", device_get_nameunit(dev)));
3753 }
3754 
3755 /**
3756  * @brief Helper function for implementing BUS_PRINT_CHILD().
3757  *
3758  * This function prints out the VM domain for the given device.
3759  *
3760  * @returns the number of characters printed
3761  */
3762 int
3763 bus_print_child_domain(device_t dev, device_t child)
3764 {
3765 	int domain;
3766 
3767 	/* No domain? Don't print anything */
3768 	if (BUS_GET_DOMAIN(dev, child, &domain) != 0)
3769 		return (0);
3770 
3771 	return (printf(" numa-domain %d", domain));
3772 }
3773 
3774 /**
3775  * @brief Helper function for implementing BUS_PRINT_CHILD().
3776  *
3777  * This function simply calls bus_print_child_header() followed by
3778  * bus_print_child_footer().
3779  *
3780  * @returns the number of characters printed
3781  */
3782 int
3783 bus_generic_print_child(device_t dev, device_t child)
3784 {
3785 	int	retval = 0;
3786 
3787 	retval += bus_print_child_header(dev, child);
3788 	retval += bus_print_child_domain(dev, child);
3789 	retval += bus_print_child_footer(dev, child);
3790 
3791 	return (retval);
3792 }
3793 
3794 /**
3795  * @brief Stub function for implementing BUS_READ_IVAR().
3796  *
3797  * @returns ENOENT
3798  */
3799 int
3800 bus_generic_read_ivar(device_t dev, device_t child, int index,
3801     uintptr_t * result)
3802 {
3803 	return (ENOENT);
3804 }
3805 
3806 /**
3807  * @brief Stub function for implementing BUS_WRITE_IVAR().
3808  *
3809  * @returns ENOENT
3810  */
3811 int
3812 bus_generic_write_ivar(device_t dev, device_t child, int index,
3813     uintptr_t value)
3814 {
3815 	return (ENOENT);
3816 }
3817 
3818 /**
3819  * @brief Stub function for implementing BUS_GET_RESOURCE_LIST().
3820  *
3821  * @returns NULL
3822  */
3823 struct resource_list *
3824 bus_generic_get_resource_list(device_t dev, device_t child)
3825 {
3826 	return (NULL);
3827 }
3828 
3829 /**
3830  * @brief Helper function for implementing BUS_DRIVER_ADDED().
3831  *
3832  * This implementation of BUS_DRIVER_ADDED() simply calls the driver's
3833  * DEVICE_IDENTIFY() method to allow it to add new children to the bus
3834  * and then calls device_probe_and_attach() for each unattached child.
3835  */
3836 void
3837 bus_generic_driver_added(device_t dev, driver_t *driver)
3838 {
3839 	device_t child;
3840 
3841 	DEVICE_IDENTIFY(driver, dev);
3842 	TAILQ_FOREACH(child, &dev->children, link) {
3843 		if (child->state == DS_NOTPRESENT ||
3844 		    (child->flags & DF_REBID))
3845 			device_probe_and_attach(child);
3846 	}
3847 }
3848 
3849 /**
3850  * @brief Helper function for implementing BUS_NEW_PASS().
3851  *
3852  * This implementing of BUS_NEW_PASS() first calls the identify
3853  * routines for any drivers that probe at the current pass.  Then it
3854  * walks the list of devices for this bus.  If a device is already
3855  * attached, then it calls BUS_NEW_PASS() on that device.  If the
3856  * device is not already attached, it attempts to attach a driver to
3857  * it.
3858  */
3859 void
3860 bus_generic_new_pass(device_t dev)
3861 {
3862 	driverlink_t dl;
3863 	devclass_t dc;
3864 	device_t child;
3865 
3866 	dc = dev->devclass;
3867 	TAILQ_FOREACH(dl, &dc->drivers, link) {
3868 		if (dl->pass == bus_current_pass)
3869 			DEVICE_IDENTIFY(dl->driver, dev);
3870 	}
3871 	TAILQ_FOREACH(child, &dev->children, link) {
3872 		if (child->state >= DS_ATTACHED)
3873 			BUS_NEW_PASS(child);
3874 		else if (child->state == DS_NOTPRESENT)
3875 			device_probe_and_attach(child);
3876 	}
3877 }
3878 
3879 /**
3880  * @brief Helper function for implementing BUS_SETUP_INTR().
3881  *
3882  * This simple implementation of BUS_SETUP_INTR() simply calls the
3883  * BUS_SETUP_INTR() method of the parent of @p dev.
3884  */
3885 int
3886 bus_generic_setup_intr(device_t dev, device_t child, struct resource *irq,
3887     int flags, driver_filter_t *filter, driver_intr_t *intr, void *arg,
3888     void **cookiep)
3889 {
3890 	/* Propagate up the bus hierarchy until someone handles it. */
3891 	if (dev->parent)
3892 		return (BUS_SETUP_INTR(dev->parent, child, irq, flags,
3893 		    filter, intr, arg, cookiep));
3894 	return (EINVAL);
3895 }
3896 
3897 /**
3898  * @brief Helper function for implementing BUS_TEARDOWN_INTR().
3899  *
3900  * This simple implementation of BUS_TEARDOWN_INTR() simply calls the
3901  * BUS_TEARDOWN_INTR() method of the parent of @p dev.
3902  */
3903 int
3904 bus_generic_teardown_intr(device_t dev, device_t child, struct resource *irq,
3905     void *cookie)
3906 {
3907 	/* Propagate up the bus hierarchy until someone handles it. */
3908 	if (dev->parent)
3909 		return (BUS_TEARDOWN_INTR(dev->parent, child, irq, cookie));
3910 	return (EINVAL);
3911 }
3912 
3913 /**
3914  * @brief Helper function for implementing BUS_ADJUST_RESOURCE().
3915  *
3916  * This simple implementation of BUS_ADJUST_RESOURCE() simply calls the
3917  * BUS_ADJUST_RESOURCE() method of the parent of @p dev.
3918  */
3919 int
3920 bus_generic_adjust_resource(device_t dev, device_t child, int type,
3921     struct resource *r, u_long start, u_long end)
3922 {
3923 	/* Propagate up the bus hierarchy until someone handles it. */
3924 	if (dev->parent)
3925 		return (BUS_ADJUST_RESOURCE(dev->parent, child, type, r, start,
3926 		    end));
3927 	return (EINVAL);
3928 }
3929 
3930 /**
3931  * @brief Helper function for implementing BUS_ALLOC_RESOURCE().
3932  *
3933  * This simple implementation of BUS_ALLOC_RESOURCE() simply calls the
3934  * BUS_ALLOC_RESOURCE() method of the parent of @p dev.
3935  */
3936 struct resource *
3937 bus_generic_alloc_resource(device_t dev, device_t child, int type, int *rid,
3938     u_long start, u_long end, u_long count, u_int flags)
3939 {
3940 	/* Propagate up the bus hierarchy until someone handles it. */
3941 	if (dev->parent)
3942 		return (BUS_ALLOC_RESOURCE(dev->parent, child, type, rid,
3943 		    start, end, count, flags));
3944 	return (NULL);
3945 }
3946 
3947 /**
3948  * @brief Helper function for implementing BUS_RELEASE_RESOURCE().
3949  *
3950  * This simple implementation of BUS_RELEASE_RESOURCE() simply calls the
3951  * BUS_RELEASE_RESOURCE() method of the parent of @p dev.
3952  */
3953 int
3954 bus_generic_release_resource(device_t dev, device_t child, int type, int rid,
3955     struct resource *r)
3956 {
3957 	/* Propagate up the bus hierarchy until someone handles it. */
3958 	if (dev->parent)
3959 		return (BUS_RELEASE_RESOURCE(dev->parent, child, type, rid,
3960 		    r));
3961 	return (EINVAL);
3962 }
3963 
3964 /**
3965  * @brief Helper function for implementing BUS_ACTIVATE_RESOURCE().
3966  *
3967  * This simple implementation of BUS_ACTIVATE_RESOURCE() simply calls the
3968  * BUS_ACTIVATE_RESOURCE() method of the parent of @p dev.
3969  */
3970 int
3971 bus_generic_activate_resource(device_t dev, device_t child, int type, int rid,
3972     struct resource *r)
3973 {
3974 	/* Propagate up the bus hierarchy until someone handles it. */
3975 	if (dev->parent)
3976 		return (BUS_ACTIVATE_RESOURCE(dev->parent, child, type, rid,
3977 		    r));
3978 	return (EINVAL);
3979 }
3980 
3981 /**
3982  * @brief Helper function for implementing BUS_DEACTIVATE_RESOURCE().
3983  *
3984  * This simple implementation of BUS_DEACTIVATE_RESOURCE() simply calls the
3985  * BUS_DEACTIVATE_RESOURCE() method of the parent of @p dev.
3986  */
3987 int
3988 bus_generic_deactivate_resource(device_t dev, device_t child, int type,
3989     int rid, struct resource *r)
3990 {
3991 	/* Propagate up the bus hierarchy until someone handles it. */
3992 	if (dev->parent)
3993 		return (BUS_DEACTIVATE_RESOURCE(dev->parent, child, type, rid,
3994 		    r));
3995 	return (EINVAL);
3996 }
3997 
3998 /**
3999  * @brief Helper function for implementing BUS_BIND_INTR().
4000  *
4001  * This simple implementation of BUS_BIND_INTR() simply calls the
4002  * BUS_BIND_INTR() method of the parent of @p dev.
4003  */
4004 int
4005 bus_generic_bind_intr(device_t dev, device_t child, struct resource *irq,
4006     int cpu)
4007 {
4008 
4009 	/* Propagate up the bus hierarchy until someone handles it. */
4010 	if (dev->parent)
4011 		return (BUS_BIND_INTR(dev->parent, child, irq, cpu));
4012 	return (EINVAL);
4013 }
4014 
4015 /**
4016  * @brief Helper function for implementing BUS_CONFIG_INTR().
4017  *
4018  * This simple implementation of BUS_CONFIG_INTR() simply calls the
4019  * BUS_CONFIG_INTR() method of the parent of @p dev.
4020  */
4021 int
4022 bus_generic_config_intr(device_t dev, int irq, enum intr_trigger trig,
4023     enum intr_polarity pol)
4024 {
4025 
4026 	/* Propagate up the bus hierarchy until someone handles it. */
4027 	if (dev->parent)
4028 		return (BUS_CONFIG_INTR(dev->parent, irq, trig, pol));
4029 	return (EINVAL);
4030 }
4031 
4032 /**
4033  * @brief Helper function for implementing BUS_DESCRIBE_INTR().
4034  *
4035  * This simple implementation of BUS_DESCRIBE_INTR() simply calls the
4036  * BUS_DESCRIBE_INTR() method of the parent of @p dev.
4037  */
4038 int
4039 bus_generic_describe_intr(device_t dev, device_t child, struct resource *irq,
4040     void *cookie, const char *descr)
4041 {
4042 
4043 	/* Propagate up the bus hierarchy until someone handles it. */
4044 	if (dev->parent)
4045 		return (BUS_DESCRIBE_INTR(dev->parent, child, irq, cookie,
4046 		    descr));
4047 	return (EINVAL);
4048 }
4049 
4050 /**
4051  * @brief Helper function for implementing BUS_GET_DMA_TAG().
4052  *
4053  * This simple implementation of BUS_GET_DMA_TAG() simply calls the
4054  * BUS_GET_DMA_TAG() method of the parent of @p dev.
4055  */
4056 bus_dma_tag_t
4057 bus_generic_get_dma_tag(device_t dev, device_t child)
4058 {
4059 
4060 	/* Propagate up the bus hierarchy until someone handles it. */
4061 	if (dev->parent != NULL)
4062 		return (BUS_GET_DMA_TAG(dev->parent, child));
4063 	return (NULL);
4064 }
4065 
4066 /**
4067  * @brief Helper function for implementing BUS_GET_RESOURCE().
4068  *
4069  * This implementation of BUS_GET_RESOURCE() uses the
4070  * resource_list_find() function to do most of the work. It calls
4071  * BUS_GET_RESOURCE_LIST() to find a suitable resource list to
4072  * search.
4073  */
4074 int
4075 bus_generic_rl_get_resource(device_t dev, device_t child, int type, int rid,
4076     u_long *startp, u_long *countp)
4077 {
4078 	struct resource_list *		rl = NULL;
4079 	struct resource_list_entry *	rle = NULL;
4080 
4081 	rl = BUS_GET_RESOURCE_LIST(dev, child);
4082 	if (!rl)
4083 		return (EINVAL);
4084 
4085 	rle = resource_list_find(rl, type, rid);
4086 	if (!rle)
4087 		return (ENOENT);
4088 
4089 	if (startp)
4090 		*startp = rle->start;
4091 	if (countp)
4092 		*countp = rle->count;
4093 
4094 	return (0);
4095 }
4096 
4097 /**
4098  * @brief Helper function for implementing BUS_SET_RESOURCE().
4099  *
4100  * This implementation of BUS_SET_RESOURCE() uses the
4101  * resource_list_add() function to do most of the work. It calls
4102  * BUS_GET_RESOURCE_LIST() to find a suitable resource list to
4103  * edit.
4104  */
4105 int
4106 bus_generic_rl_set_resource(device_t dev, device_t child, int type, int rid,
4107     u_long start, u_long count)
4108 {
4109 	struct resource_list *		rl = NULL;
4110 
4111 	rl = BUS_GET_RESOURCE_LIST(dev, child);
4112 	if (!rl)
4113 		return (EINVAL);
4114 
4115 	resource_list_add(rl, type, rid, start, (start + count - 1), count);
4116 
4117 	return (0);
4118 }
4119 
4120 /**
4121  * @brief Helper function for implementing BUS_DELETE_RESOURCE().
4122  *
4123  * This implementation of BUS_DELETE_RESOURCE() uses the
4124  * resource_list_delete() function to do most of the work. It calls
4125  * BUS_GET_RESOURCE_LIST() to find a suitable resource list to
4126  * edit.
4127  */
4128 void
4129 bus_generic_rl_delete_resource(device_t dev, device_t child, int type, int rid)
4130 {
4131 	struct resource_list *		rl = NULL;
4132 
4133 	rl = BUS_GET_RESOURCE_LIST(dev, child);
4134 	if (!rl)
4135 		return;
4136 
4137 	resource_list_delete(rl, type, rid);
4138 
4139 	return;
4140 }
4141 
4142 /**
4143  * @brief Helper function for implementing BUS_RELEASE_RESOURCE().
4144  *
4145  * This implementation of BUS_RELEASE_RESOURCE() uses the
4146  * resource_list_release() function to do most of the work. It calls
4147  * BUS_GET_RESOURCE_LIST() to find a suitable resource list.
4148  */
4149 int
4150 bus_generic_rl_release_resource(device_t dev, device_t child, int type,
4151     int rid, struct resource *r)
4152 {
4153 	struct resource_list *		rl = NULL;
4154 
4155 	if (device_get_parent(child) != dev)
4156 		return (BUS_RELEASE_RESOURCE(device_get_parent(dev), child,
4157 		    type, rid, r));
4158 
4159 	rl = BUS_GET_RESOURCE_LIST(dev, child);
4160 	if (!rl)
4161 		return (EINVAL);
4162 
4163 	return (resource_list_release(rl, dev, child, type, rid, r));
4164 }
4165 
4166 /**
4167  * @brief Helper function for implementing BUS_ALLOC_RESOURCE().
4168  *
4169  * This implementation of BUS_ALLOC_RESOURCE() uses the
4170  * resource_list_alloc() function to do most of the work. It calls
4171  * BUS_GET_RESOURCE_LIST() to find a suitable resource list.
4172  */
4173 struct resource *
4174 bus_generic_rl_alloc_resource(device_t dev, device_t child, int type,
4175     int *rid, u_long start, u_long end, u_long count, u_int flags)
4176 {
4177 	struct resource_list *		rl = NULL;
4178 
4179 	if (device_get_parent(child) != dev)
4180 		return (BUS_ALLOC_RESOURCE(device_get_parent(dev), child,
4181 		    type, rid, start, end, count, flags));
4182 
4183 	rl = BUS_GET_RESOURCE_LIST(dev, child);
4184 	if (!rl)
4185 		return (NULL);
4186 
4187 	return (resource_list_alloc(rl, dev, child, type, rid,
4188 	    start, end, count, flags));
4189 }
4190 
4191 /**
4192  * @brief Helper function for implementing BUS_CHILD_PRESENT().
4193  *
4194  * This simple implementation of BUS_CHILD_PRESENT() simply calls the
4195  * BUS_CHILD_PRESENT() method of the parent of @p dev.
4196  */
4197 int
4198 bus_generic_child_present(device_t dev, device_t child)
4199 {
4200 	return (BUS_CHILD_PRESENT(device_get_parent(dev), dev));
4201 }
4202 
4203 int
4204 bus_generic_get_domain(device_t dev, device_t child, int *domain)
4205 {
4206 
4207 	if (dev->parent)
4208 		return (BUS_GET_DOMAIN(dev->parent, dev, domain));
4209 
4210 	return (ENOENT);
4211 }
4212 
4213 /*
4214  * Some convenience functions to make it easier for drivers to use the
4215  * resource-management functions.  All these really do is hide the
4216  * indirection through the parent's method table, making for slightly
4217  * less-wordy code.  In the future, it might make sense for this code
4218  * to maintain some sort of a list of resources allocated by each device.
4219  */
4220 
4221 int
4222 bus_alloc_resources(device_t dev, struct resource_spec *rs,
4223     struct resource **res)
4224 {
4225 	int i;
4226 
4227 	for (i = 0; rs[i].type != -1; i++)
4228 		res[i] = NULL;
4229 	for (i = 0; rs[i].type != -1; i++) {
4230 		res[i] = bus_alloc_resource_any(dev,
4231 		    rs[i].type, &rs[i].rid, rs[i].flags);
4232 		if (res[i] == NULL && !(rs[i].flags & RF_OPTIONAL)) {
4233 			bus_release_resources(dev, rs, res);
4234 			return (ENXIO);
4235 		}
4236 	}
4237 	return (0);
4238 }
4239 
4240 void
4241 bus_release_resources(device_t dev, const struct resource_spec *rs,
4242     struct resource **res)
4243 {
4244 	int i;
4245 
4246 	for (i = 0; rs[i].type != -1; i++)
4247 		if (res[i] != NULL) {
4248 			bus_release_resource(
4249 			    dev, rs[i].type, rs[i].rid, res[i]);
4250 			res[i] = NULL;
4251 		}
4252 }
4253 
4254 /**
4255  * @brief Wrapper function for BUS_ALLOC_RESOURCE().
4256  *
4257  * This function simply calls the BUS_ALLOC_RESOURCE() method of the
4258  * parent of @p dev.
4259  */
4260 struct resource *
4261 bus_alloc_resource(device_t dev, int type, int *rid, u_long start, u_long end,
4262     u_long count, u_int flags)
4263 {
4264 	if (dev->parent == NULL)
4265 		return (NULL);
4266 	return (BUS_ALLOC_RESOURCE(dev->parent, dev, type, rid, start, end,
4267 	    count, flags));
4268 }
4269 
4270 /**
4271  * @brief Wrapper function for BUS_ADJUST_RESOURCE().
4272  *
4273  * This function simply calls the BUS_ADJUST_RESOURCE() method of the
4274  * parent of @p dev.
4275  */
4276 int
4277 bus_adjust_resource(device_t dev, int type, struct resource *r, u_long start,
4278     u_long end)
4279 {
4280 	if (dev->parent == NULL)
4281 		return (EINVAL);
4282 	return (BUS_ADJUST_RESOURCE(dev->parent, dev, type, r, start, end));
4283 }
4284 
4285 /**
4286  * @brief Wrapper function for BUS_ACTIVATE_RESOURCE().
4287  *
4288  * This function simply calls the BUS_ACTIVATE_RESOURCE() method of the
4289  * parent of @p dev.
4290  */
4291 int
4292 bus_activate_resource(device_t dev, int type, int rid, struct resource *r)
4293 {
4294 	if (dev->parent == NULL)
4295 		return (EINVAL);
4296 	return (BUS_ACTIVATE_RESOURCE(dev->parent, dev, type, rid, r));
4297 }
4298 
4299 /**
4300  * @brief Wrapper function for BUS_DEACTIVATE_RESOURCE().
4301  *
4302  * This function simply calls the BUS_DEACTIVATE_RESOURCE() method of the
4303  * parent of @p dev.
4304  */
4305 int
4306 bus_deactivate_resource(device_t dev, int type, int rid, struct resource *r)
4307 {
4308 	if (dev->parent == NULL)
4309 		return (EINVAL);
4310 	return (BUS_DEACTIVATE_RESOURCE(dev->parent, dev, type, rid, r));
4311 }
4312 
4313 /**
4314  * @brief Wrapper function for BUS_RELEASE_RESOURCE().
4315  *
4316  * This function simply calls the BUS_RELEASE_RESOURCE() method of the
4317  * parent of @p dev.
4318  */
4319 int
4320 bus_release_resource(device_t dev, int type, int rid, struct resource *r)
4321 {
4322 	if (dev->parent == NULL)
4323 		return (EINVAL);
4324 	return (BUS_RELEASE_RESOURCE(dev->parent, dev, type, rid, r));
4325 }
4326 
4327 /**
4328  * @brief Wrapper function for BUS_SETUP_INTR().
4329  *
4330  * This function simply calls the BUS_SETUP_INTR() method of the
4331  * parent of @p dev.
4332  */
4333 int
4334 bus_setup_intr(device_t dev, struct resource *r, int flags,
4335     driver_filter_t filter, driver_intr_t handler, void *arg, void **cookiep)
4336 {
4337 	int error;
4338 
4339 	if (dev->parent == NULL)
4340 		return (EINVAL);
4341 	error = BUS_SETUP_INTR(dev->parent, dev, r, flags, filter, handler,
4342 	    arg, cookiep);
4343 	if (error != 0)
4344 		return (error);
4345 	if (handler != NULL && !(flags & INTR_MPSAFE))
4346 		device_printf(dev, "[GIANT-LOCKED]\n");
4347 	return (0);
4348 }
4349 
4350 /**
4351  * @brief Wrapper function for BUS_TEARDOWN_INTR().
4352  *
4353  * This function simply calls the BUS_TEARDOWN_INTR() method of the
4354  * parent of @p dev.
4355  */
4356 int
4357 bus_teardown_intr(device_t dev, struct resource *r, void *cookie)
4358 {
4359 	if (dev->parent == NULL)
4360 		return (EINVAL);
4361 	return (BUS_TEARDOWN_INTR(dev->parent, dev, r, cookie));
4362 }
4363 
4364 /**
4365  * @brief Wrapper function for BUS_BIND_INTR().
4366  *
4367  * This function simply calls the BUS_BIND_INTR() method of the
4368  * parent of @p dev.
4369  */
4370 int
4371 bus_bind_intr(device_t dev, struct resource *r, int cpu)
4372 {
4373 	if (dev->parent == NULL)
4374 		return (EINVAL);
4375 	return (BUS_BIND_INTR(dev->parent, dev, r, cpu));
4376 }
4377 
4378 /**
4379  * @brief Wrapper function for BUS_DESCRIBE_INTR().
4380  *
4381  * This function first formats the requested description into a
4382  * temporary buffer and then calls the BUS_DESCRIBE_INTR() method of
4383  * the parent of @p dev.
4384  */
4385 int
4386 bus_describe_intr(device_t dev, struct resource *irq, void *cookie,
4387     const char *fmt, ...)
4388 {
4389 	va_list ap;
4390 	char descr[MAXCOMLEN + 1];
4391 
4392 	if (dev->parent == NULL)
4393 		return (EINVAL);
4394 	va_start(ap, fmt);
4395 	vsnprintf(descr, sizeof(descr), fmt, ap);
4396 	va_end(ap);
4397 	return (BUS_DESCRIBE_INTR(dev->parent, dev, irq, cookie, descr));
4398 }
4399 
4400 /**
4401  * @brief Wrapper function for BUS_SET_RESOURCE().
4402  *
4403  * This function simply calls the BUS_SET_RESOURCE() method of the
4404  * parent of @p dev.
4405  */
4406 int
4407 bus_set_resource(device_t dev, int type, int rid,
4408     u_long start, u_long count)
4409 {
4410 	return (BUS_SET_RESOURCE(device_get_parent(dev), dev, type, rid,
4411 	    start, count));
4412 }
4413 
4414 /**
4415  * @brief Wrapper function for BUS_GET_RESOURCE().
4416  *
4417  * This function simply calls the BUS_GET_RESOURCE() method of the
4418  * parent of @p dev.
4419  */
4420 int
4421 bus_get_resource(device_t dev, int type, int rid,
4422     u_long *startp, u_long *countp)
4423 {
4424 	return (BUS_GET_RESOURCE(device_get_parent(dev), dev, type, rid,
4425 	    startp, countp));
4426 }
4427 
4428 /**
4429  * @brief Wrapper function for BUS_GET_RESOURCE().
4430  *
4431  * This function simply calls the BUS_GET_RESOURCE() method of the
4432  * parent of @p dev and returns the start value.
4433  */
4434 u_long
4435 bus_get_resource_start(device_t dev, int type, int rid)
4436 {
4437 	u_long start, count;
4438 	int error;
4439 
4440 	error = BUS_GET_RESOURCE(device_get_parent(dev), dev, type, rid,
4441 	    &start, &count);
4442 	if (error)
4443 		return (0);
4444 	return (start);
4445 }
4446 
4447 /**
4448  * @brief Wrapper function for BUS_GET_RESOURCE().
4449  *
4450  * This function simply calls the BUS_GET_RESOURCE() method of the
4451  * parent of @p dev and returns the count value.
4452  */
4453 u_long
4454 bus_get_resource_count(device_t dev, int type, int rid)
4455 {
4456 	u_long start, count;
4457 	int error;
4458 
4459 	error = BUS_GET_RESOURCE(device_get_parent(dev), dev, type, rid,
4460 	    &start, &count);
4461 	if (error)
4462 		return (0);
4463 	return (count);
4464 }
4465 
4466 /**
4467  * @brief Wrapper function for BUS_DELETE_RESOURCE().
4468  *
4469  * This function simply calls the BUS_DELETE_RESOURCE() method of the
4470  * parent of @p dev.
4471  */
4472 void
4473 bus_delete_resource(device_t dev, int type, int rid)
4474 {
4475 	BUS_DELETE_RESOURCE(device_get_parent(dev), dev, type, rid);
4476 }
4477 
4478 /**
4479  * @brief Wrapper function for BUS_CHILD_PRESENT().
4480  *
4481  * This function simply calls the BUS_CHILD_PRESENT() method of the
4482  * parent of @p dev.
4483  */
4484 int
4485 bus_child_present(device_t child)
4486 {
4487 	return (BUS_CHILD_PRESENT(device_get_parent(child), child));
4488 }
4489 
4490 /**
4491  * @brief Wrapper function for BUS_CHILD_PNPINFO_STR().
4492  *
4493  * This function simply calls the BUS_CHILD_PNPINFO_STR() method of the
4494  * parent of @p dev.
4495  */
4496 int
4497 bus_child_pnpinfo_str(device_t child, char *buf, size_t buflen)
4498 {
4499 	device_t parent;
4500 
4501 	parent = device_get_parent(child);
4502 	if (parent == NULL) {
4503 		*buf = '\0';
4504 		return (0);
4505 	}
4506 	return (BUS_CHILD_PNPINFO_STR(parent, child, buf, buflen));
4507 }
4508 
4509 /**
4510  * @brief Wrapper function for BUS_CHILD_LOCATION_STR().
4511  *
4512  * This function simply calls the BUS_CHILD_LOCATION_STR() method of the
4513  * parent of @p dev.
4514  */
4515 int
4516 bus_child_location_str(device_t child, char *buf, size_t buflen)
4517 {
4518 	device_t parent;
4519 
4520 	parent = device_get_parent(child);
4521 	if (parent == NULL) {
4522 		*buf = '\0';
4523 		return (0);
4524 	}
4525 	return (BUS_CHILD_LOCATION_STR(parent, child, buf, buflen));
4526 }
4527 
4528 /**
4529  * @brief Wrapper function for BUS_GET_DMA_TAG().
4530  *
4531  * This function simply calls the BUS_GET_DMA_TAG() method of the
4532  * parent of @p dev.
4533  */
4534 bus_dma_tag_t
4535 bus_get_dma_tag(device_t dev)
4536 {
4537 	device_t parent;
4538 
4539 	parent = device_get_parent(dev);
4540 	if (parent == NULL)
4541 		return (NULL);
4542 	return (BUS_GET_DMA_TAG(parent, dev));
4543 }
4544 
4545 /* Resume all devices and then notify userland that we're up again. */
4546 static int
4547 root_resume(device_t dev)
4548 {
4549 	int error;
4550 
4551 	error = bus_generic_resume(dev);
4552 	if (error == 0)
4553 		devctl_notify("kern", "power", "resume", NULL);
4554 	return (error);
4555 }
4556 
4557 static int
4558 root_print_child(device_t dev, device_t child)
4559 {
4560 	int	retval = 0;
4561 
4562 	retval += bus_print_child_header(dev, child);
4563 	retval += printf("\n");
4564 
4565 	return (retval);
4566 }
4567 
4568 static int
4569 root_setup_intr(device_t dev, device_t child, struct resource *irq, int flags,
4570     driver_filter_t *filter, driver_intr_t *intr, void *arg, void **cookiep)
4571 {
4572 	/*
4573 	 * If an interrupt mapping gets to here something bad has happened.
4574 	 */
4575 	panic("root_setup_intr");
4576 }
4577 
4578 /*
4579  * If we get here, assume that the device is permanant and really is
4580  * present in the system.  Removable bus drivers are expected to intercept
4581  * this call long before it gets here.  We return -1 so that drivers that
4582  * really care can check vs -1 or some ERRNO returned higher in the food
4583  * chain.
4584  */
4585 static int
4586 root_child_present(device_t dev, device_t child)
4587 {
4588 	return (-1);
4589 }
4590 
4591 static kobj_method_t root_methods[] = {
4592 	/* Device interface */
4593 	KOBJMETHOD(device_shutdown,	bus_generic_shutdown),
4594 	KOBJMETHOD(device_suspend,	bus_generic_suspend),
4595 	KOBJMETHOD(device_resume,	root_resume),
4596 
4597 	/* Bus interface */
4598 	KOBJMETHOD(bus_print_child,	root_print_child),
4599 	KOBJMETHOD(bus_read_ivar,	bus_generic_read_ivar),
4600 	KOBJMETHOD(bus_write_ivar,	bus_generic_write_ivar),
4601 	KOBJMETHOD(bus_setup_intr,	root_setup_intr),
4602 	KOBJMETHOD(bus_child_present,	root_child_present),
4603 
4604 	KOBJMETHOD_END
4605 };
4606 
4607 static driver_t root_driver = {
4608 	"root",
4609 	root_methods,
4610 	1,			/* no softc */
4611 };
4612 
4613 device_t	root_bus;
4614 devclass_t	root_devclass;
4615 
4616 static int
4617 root_bus_module_handler(module_t mod, int what, void* arg)
4618 {
4619 	switch (what) {
4620 	case MOD_LOAD:
4621 		TAILQ_INIT(&bus_data_devices);
4622 		kobj_class_compile((kobj_class_t) &root_driver);
4623 		root_bus = make_device(NULL, "root", 0);
4624 		root_bus->desc = "System root bus";
4625 		kobj_init((kobj_t) root_bus, (kobj_class_t) &root_driver);
4626 		root_bus->driver = &root_driver;
4627 		root_bus->state = DS_ATTACHED;
4628 		root_devclass = devclass_find_internal("root", NULL, FALSE);
4629 		devinit();
4630 		return (0);
4631 
4632 	case MOD_SHUTDOWN:
4633 		device_shutdown(root_bus);
4634 		return (0);
4635 	default:
4636 		return (EOPNOTSUPP);
4637 	}
4638 
4639 	return (0);
4640 }
4641 
4642 static moduledata_t root_bus_mod = {
4643 	"rootbus",
4644 	root_bus_module_handler,
4645 	NULL
4646 };
4647 DECLARE_MODULE(rootbus, root_bus_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
4648 
4649 /**
4650  * @brief Automatically configure devices
4651  *
4652  * This function begins the autoconfiguration process by calling
4653  * device_probe_and_attach() for each child of the @c root0 device.
4654  */
4655 void
4656 root_bus_configure(void)
4657 {
4658 
4659 	PDEBUG(("."));
4660 
4661 	/* Eventually this will be split up, but this is sufficient for now. */
4662 	bus_set_pass(BUS_PASS_DEFAULT);
4663 }
4664 
4665 /**
4666  * @brief Module handler for registering device drivers
4667  *
4668  * This module handler is used to automatically register device
4669  * drivers when modules are loaded. If @p what is MOD_LOAD, it calls
4670  * devclass_add_driver() for the driver described by the
4671  * driver_module_data structure pointed to by @p arg
4672  */
4673 int
4674 driver_module_handler(module_t mod, int what, void *arg)
4675 {
4676 	struct driver_module_data *dmd;
4677 	devclass_t bus_devclass;
4678 	kobj_class_t driver;
4679 	int error, pass;
4680 
4681 	dmd = (struct driver_module_data *)arg;
4682 	bus_devclass = devclass_find_internal(dmd->dmd_busname, NULL, TRUE);
4683 	error = 0;
4684 
4685 	switch (what) {
4686 	case MOD_LOAD:
4687 		if (dmd->dmd_chainevh)
4688 			error = dmd->dmd_chainevh(mod,what,dmd->dmd_chainarg);
4689 
4690 		pass = dmd->dmd_pass;
4691 		driver = dmd->dmd_driver;
4692 		PDEBUG(("Loading module: driver %s on bus %s (pass %d)",
4693 		    DRIVERNAME(driver), dmd->dmd_busname, pass));
4694 		error = devclass_add_driver(bus_devclass, driver, pass,
4695 		    dmd->dmd_devclass);
4696 		break;
4697 
4698 	case MOD_UNLOAD:
4699 		PDEBUG(("Unloading module: driver %s from bus %s",
4700 		    DRIVERNAME(dmd->dmd_driver),
4701 		    dmd->dmd_busname));
4702 		error = devclass_delete_driver(bus_devclass,
4703 		    dmd->dmd_driver);
4704 
4705 		if (!error && dmd->dmd_chainevh)
4706 			error = dmd->dmd_chainevh(mod,what,dmd->dmd_chainarg);
4707 		break;
4708 	case MOD_QUIESCE:
4709 		PDEBUG(("Quiesce module: driver %s from bus %s",
4710 		    DRIVERNAME(dmd->dmd_driver),
4711 		    dmd->dmd_busname));
4712 		error = devclass_quiesce_driver(bus_devclass,
4713 		    dmd->dmd_driver);
4714 
4715 		if (!error && dmd->dmd_chainevh)
4716 			error = dmd->dmd_chainevh(mod,what,dmd->dmd_chainarg);
4717 		break;
4718 	default:
4719 		error = EOPNOTSUPP;
4720 		break;
4721 	}
4722 
4723 	return (error);
4724 }
4725 
4726 /**
4727  * @brief Enumerate all hinted devices for this bus.
4728  *
4729  * Walks through the hints for this bus and calls the bus_hinted_child
4730  * routine for each one it fines.  It searches first for the specific
4731  * bus that's being probed for hinted children (eg isa0), and then for
4732  * generic children (eg isa).
4733  *
4734  * @param	dev	bus device to enumerate
4735  */
4736 void
4737 bus_enumerate_hinted_children(device_t bus)
4738 {
4739 	int i;
4740 	const char *dname, *busname;
4741 	int dunit;
4742 
4743 	/*
4744 	 * enumerate all devices on the specific bus
4745 	 */
4746 	busname = device_get_nameunit(bus);
4747 	i = 0;
4748 	while (resource_find_match(&i, &dname, &dunit, "at", busname) == 0)
4749 		BUS_HINTED_CHILD(bus, dname, dunit);
4750 
4751 	/*
4752 	 * and all the generic ones.
4753 	 */
4754 	busname = device_get_name(bus);
4755 	i = 0;
4756 	while (resource_find_match(&i, &dname, &dunit, "at", busname) == 0)
4757 		BUS_HINTED_CHILD(bus, dname, dunit);
4758 }
4759 
4760 #ifdef BUS_DEBUG
4761 
4762 /* the _short versions avoid iteration by not calling anything that prints
4763  * more than oneliners. I love oneliners.
4764  */
4765 
4766 static void
4767 print_device_short(device_t dev, int indent)
4768 {
4769 	if (!dev)
4770 		return;
4771 
4772 	indentprintf(("device %d: <%s> %sparent,%schildren,%s%s%s%s%s,%sivars,%ssoftc,busy=%d\n",
4773 	    dev->unit, dev->desc,
4774 	    (dev->parent? "":"no "),
4775 	    (TAILQ_EMPTY(&dev->children)? "no ":""),
4776 	    (dev->flags&DF_ENABLED? "enabled,":"disabled,"),
4777 	    (dev->flags&DF_FIXEDCLASS? "fixed,":""),
4778 	    (dev->flags&DF_WILDCARD? "wildcard,":""),
4779 	    (dev->flags&DF_DESCMALLOCED? "descmalloced,":""),
4780 	    (dev->flags&DF_REBID? "rebiddable,":""),
4781 	    (dev->ivars? "":"no "),
4782 	    (dev->softc? "":"no "),
4783 	    dev->busy));
4784 }
4785 
4786 static void
4787 print_device(device_t dev, int indent)
4788 {
4789 	if (!dev)
4790 		return;
4791 
4792 	print_device_short(dev, indent);
4793 
4794 	indentprintf(("Parent:\n"));
4795 	print_device_short(dev->parent, indent+1);
4796 	indentprintf(("Driver:\n"));
4797 	print_driver_short(dev->driver, indent+1);
4798 	indentprintf(("Devclass:\n"));
4799 	print_devclass_short(dev->devclass, indent+1);
4800 }
4801 
4802 void
4803 print_device_tree_short(device_t dev, int indent)
4804 /* print the device and all its children (indented) */
4805 {
4806 	device_t child;
4807 
4808 	if (!dev)
4809 		return;
4810 
4811 	print_device_short(dev, indent);
4812 
4813 	TAILQ_FOREACH(child, &dev->children, link) {
4814 		print_device_tree_short(child, indent+1);
4815 	}
4816 }
4817 
4818 void
4819 print_device_tree(device_t dev, int indent)
4820 /* print the device and all its children (indented) */
4821 {
4822 	device_t child;
4823 
4824 	if (!dev)
4825 		return;
4826 
4827 	print_device(dev, indent);
4828 
4829 	TAILQ_FOREACH(child, &dev->children, link) {
4830 		print_device_tree(child, indent+1);
4831 	}
4832 }
4833 
4834 static void
4835 print_driver_short(driver_t *driver, int indent)
4836 {
4837 	if (!driver)
4838 		return;
4839 
4840 	indentprintf(("driver %s: softc size = %zd\n",
4841 	    driver->name, driver->size));
4842 }
4843 
4844 static void
4845 print_driver(driver_t *driver, int indent)
4846 {
4847 	if (!driver)
4848 		return;
4849 
4850 	print_driver_short(driver, indent);
4851 }
4852 
4853 static void
4854 print_driver_list(driver_list_t drivers, int indent)
4855 {
4856 	driverlink_t driver;
4857 
4858 	TAILQ_FOREACH(driver, &drivers, link) {
4859 		print_driver(driver->driver, indent);
4860 	}
4861 }
4862 
4863 static void
4864 print_devclass_short(devclass_t dc, int indent)
4865 {
4866 	if ( !dc )
4867 		return;
4868 
4869 	indentprintf(("devclass %s: max units = %d\n", dc->name, dc->maxunit));
4870 }
4871 
4872 static void
4873 print_devclass(devclass_t dc, int indent)
4874 {
4875 	int i;
4876 
4877 	if ( !dc )
4878 		return;
4879 
4880 	print_devclass_short(dc, indent);
4881 	indentprintf(("Drivers:\n"));
4882 	print_driver_list(dc->drivers, indent+1);
4883 
4884 	indentprintf(("Devices:\n"));
4885 	for (i = 0; i < dc->maxunit; i++)
4886 		if (dc->devices[i])
4887 			print_device(dc->devices[i], indent+1);
4888 }
4889 
4890 void
4891 print_devclass_list_short(void)
4892 {
4893 	devclass_t dc;
4894 
4895 	printf("Short listing of devclasses, drivers & devices:\n");
4896 	TAILQ_FOREACH(dc, &devclasses, link) {
4897 		print_devclass_short(dc, 0);
4898 	}
4899 }
4900 
4901 void
4902 print_devclass_list(void)
4903 {
4904 	devclass_t dc;
4905 
4906 	printf("Full listing of devclasses, drivers & devices:\n");
4907 	TAILQ_FOREACH(dc, &devclasses, link) {
4908 		print_devclass(dc, 0);
4909 	}
4910 }
4911 
4912 #endif
4913 
4914 /*
4915  * User-space access to the device tree.
4916  *
4917  * We implement a small set of nodes:
4918  *
4919  * hw.bus			Single integer read method to obtain the
4920  *				current generation count.
4921  * hw.bus.devices		Reads the entire device tree in flat space.
4922  * hw.bus.rman			Resource manager interface
4923  *
4924  * We might like to add the ability to scan devclasses and/or drivers to
4925  * determine what else is currently loaded/available.
4926  */
4927 
4928 static int
4929 sysctl_bus(SYSCTL_HANDLER_ARGS)
4930 {
4931 	struct u_businfo	ubus;
4932 
4933 	ubus.ub_version = BUS_USER_VERSION;
4934 	ubus.ub_generation = bus_data_generation;
4935 
4936 	return (SYSCTL_OUT(req, &ubus, sizeof(ubus)));
4937 }
4938 SYSCTL_NODE(_hw_bus, OID_AUTO, info, CTLFLAG_RW, sysctl_bus,
4939     "bus-related data");
4940 
4941 static int
4942 sysctl_devices(SYSCTL_HANDLER_ARGS)
4943 {
4944 	int			*name = (int *)arg1;
4945 	u_int			namelen = arg2;
4946 	int			index;
4947 	struct device		*dev;
4948 	struct u_device		udev;	/* XXX this is a bit big */
4949 	int			error;
4950 
4951 	if (namelen != 2)
4952 		return (EINVAL);
4953 
4954 	if (bus_data_generation_check(name[0]))
4955 		return (EINVAL);
4956 
4957 	index = name[1];
4958 
4959 	/*
4960 	 * Scan the list of devices, looking for the requested index.
4961 	 */
4962 	TAILQ_FOREACH(dev, &bus_data_devices, devlink) {
4963 		if (index-- == 0)
4964 			break;
4965 	}
4966 	if (dev == NULL)
4967 		return (ENOENT);
4968 
4969 	/*
4970 	 * Populate the return array.
4971 	 */
4972 	bzero(&udev, sizeof(udev));
4973 	udev.dv_handle = (uintptr_t)dev;
4974 	udev.dv_parent = (uintptr_t)dev->parent;
4975 	if (dev->nameunit != NULL)
4976 		strlcpy(udev.dv_name, dev->nameunit, sizeof(udev.dv_name));
4977 	if (dev->desc != NULL)
4978 		strlcpy(udev.dv_desc, dev->desc, sizeof(udev.dv_desc));
4979 	if (dev->driver != NULL && dev->driver->name != NULL)
4980 		strlcpy(udev.dv_drivername, dev->driver->name,
4981 		    sizeof(udev.dv_drivername));
4982 	bus_child_pnpinfo_str(dev, udev.dv_pnpinfo, sizeof(udev.dv_pnpinfo));
4983 	bus_child_location_str(dev, udev.dv_location, sizeof(udev.dv_location));
4984 	udev.dv_devflags = dev->devflags;
4985 	udev.dv_flags = dev->flags;
4986 	udev.dv_state = dev->state;
4987 	error = SYSCTL_OUT(req, &udev, sizeof(udev));
4988 	return (error);
4989 }
4990 
4991 SYSCTL_NODE(_hw_bus, OID_AUTO, devices, CTLFLAG_RD, sysctl_devices,
4992     "system device tree");
4993 
4994 int
4995 bus_data_generation_check(int generation)
4996 {
4997 	if (generation != bus_data_generation)
4998 		return (1);
4999 
5000 	/* XXX generate optimised lists here? */
5001 	return (0);
5002 }
5003 
5004 void
5005 bus_data_generation_update(void)
5006 {
5007 	bus_data_generation++;
5008 }
5009 
5010 int
5011 bus_free_resource(device_t dev, int type, struct resource *r)
5012 {
5013 	if (r == NULL)
5014 		return (0);
5015 	return (bus_release_resource(dev, type, rman_get_rid(r), r));
5016 }
5017