xref: /freebsd/sys/kern/subr_bus.c (revision d876124d6ae9d56da5b4ff4c6015efd1d0c9222a)
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 
32 #include <sys/param.h>
33 #include <sys/conf.h>
34 #include <sys/filio.h>
35 #include <sys/lock.h>
36 #include <sys/kernel.h>
37 #include <sys/kobj.h>
38 #include <sys/malloc.h>
39 #include <sys/module.h>
40 #include <sys/mutex.h>
41 #include <sys/poll.h>
42 #include <sys/proc.h>
43 #include <sys/condvar.h>
44 #include <sys/queue.h>
45 #include <machine/bus.h>
46 #include <sys/rman.h>
47 #include <sys/selinfo.h>
48 #include <sys/signalvar.h>
49 #include <sys/sysctl.h>
50 #include <sys/systm.h>
51 #include <sys/uio.h>
52 #include <sys/bus.h>
53 #include <sys/interrupt.h>
54 
55 #include <machine/stdarg.h>
56 
57 #include <vm/uma.h>
58 
59 SYSCTL_NODE(_hw, OID_AUTO, bus, CTLFLAG_RW, NULL, NULL);
60 SYSCTL_NODE(, OID_AUTO, dev, CTLFLAG_RW, NULL, NULL);
61 
62 /*
63  * Used to attach drivers to devclasses.
64  */
65 typedef struct driverlink *driverlink_t;
66 struct driverlink {
67 	kobj_class_t	driver;
68 	TAILQ_ENTRY(driverlink) link;	/* list of drivers in devclass */
69 };
70 
71 /*
72  * Forward declarations
73  */
74 typedef TAILQ_HEAD(devclass_list, devclass) devclass_list_t;
75 typedef TAILQ_HEAD(driver_list, driverlink) driver_list_t;
76 typedef TAILQ_HEAD(device_list, device) device_list_t;
77 
78 struct devclass {
79 	TAILQ_ENTRY(devclass) link;
80 	devclass_t	parent;		/* parent in devclass hierarchy */
81 	driver_list_t	drivers;     /* bus devclasses store drivers for bus */
82 	char		*name;
83 	device_t	*devices;	/* array of devices indexed by unit */
84 	int		maxunit;	/* size of devices array */
85 
86 	struct sysctl_ctx_list sysctl_ctx;
87 	struct sysctl_oid *sysctl_tree;
88 };
89 
90 /**
91  * @brief Implementation of device.
92  */
93 struct device {
94 	/*
95 	 * A device is a kernel object. The first field must be the
96 	 * current ops table for the object.
97 	 */
98 	KOBJ_FIELDS;
99 
100 	/*
101 	 * Device hierarchy.
102 	 */
103 	TAILQ_ENTRY(device)	link;	/**< list of devices in parent */
104 	TAILQ_ENTRY(device)	devlink; /**< global device list membership */
105 	device_t	parent;		/**< parent of this device  */
106 	device_list_t	children;	/**< list of child devices */
107 
108 	/*
109 	 * Details of this device.
110 	 */
111 	driver_t	*driver;	/**< current driver */
112 	devclass_t	devclass;	/**< current device class */
113 	int		unit;		/**< current unit number */
114 	char*		nameunit;	/**< name+unit e.g. foodev0 */
115 	char*		desc;		/**< driver specific description */
116 	int		busy;		/**< count of calls to device_busy() */
117 	device_state_t	state;		/**< current device state  */
118 	u_int32_t	devflags;	/**< api level flags for device_get_flags() */
119 	u_short		flags;		/**< internal device flags  */
120 #define	DF_ENABLED	1		/* device should be probed/attached */
121 #define	DF_FIXEDCLASS	2		/* devclass specified at create time */
122 #define	DF_WILDCARD	4		/* unit was originally wildcard */
123 #define	DF_DESCMALLOCED	8		/* description was malloced */
124 #define	DF_QUIET	16		/* don't print verbose attach message */
125 #define	DF_DONENOMATCH	32		/* don't execute DEVICE_NOMATCH again */
126 #define	DF_EXTERNALSOFTC 64		/* softc not allocated by us */
127 #define	DF_REBID	128		/* Can rebid after attach */
128 	u_char	order;			/**< order from device_add_child_ordered() */
129 	u_char	pad;
130 	void	*ivars;			/**< instance variables  */
131 	void	*softc;			/**< current driver's variables  */
132 
133 	struct sysctl_ctx_list sysctl_ctx; /**< state for sysctl variables  */
134 	struct sysctl_oid *sysctl_tree;	/**< state for sysctl variables */
135 };
136 
137 static MALLOC_DEFINE(M_BUS, "bus", "Bus data structures");
138 static MALLOC_DEFINE(M_BUS_SC, "bus-sc", "Bus data structures, softc");
139 
140 #ifdef BUS_DEBUG
141 
142 static int bus_debug = 1;
143 TUNABLE_INT("bus.debug", &bus_debug);
144 SYSCTL_INT(_debug, OID_AUTO, bus_debug, CTLFLAG_RW, &bus_debug, 0,
145     "Debug bus code");
146 
147 #define PDEBUG(a)	if (bus_debug) {printf("%s:%d: ", __func__, __LINE__), printf a; printf("\n");}
148 #define DEVICENAME(d)	((d)? device_get_name(d): "no device")
149 #define DRIVERNAME(d)	((d)? d->name : "no driver")
150 #define DEVCLANAME(d)	((d)? d->name : "no devclass")
151 
152 /**
153  * Produce the indenting, indent*2 spaces plus a '.' ahead of that to
154  * prevent syslog from deleting initial spaces
155  */
156 #define indentprintf(p)	do { int iJ; printf("."); for (iJ=0; iJ<indent; iJ++) printf("  "); printf p ; } while (0)
157 
158 static void print_device_short(device_t dev, int indent);
159 static void print_device(device_t dev, int indent);
160 void print_device_tree_short(device_t dev, int indent);
161 void print_device_tree(device_t dev, int indent);
162 static void print_driver_short(driver_t *driver, int indent);
163 static void print_driver(driver_t *driver, int indent);
164 static void print_driver_list(driver_list_t drivers, int indent);
165 static void print_devclass_short(devclass_t dc, int indent);
166 static void print_devclass(devclass_t dc, int indent);
167 void print_devclass_list_short(void);
168 void print_devclass_list(void);
169 
170 #else
171 /* Make the compiler ignore the function calls */
172 #define PDEBUG(a)			/* nop */
173 #define DEVICENAME(d)			/* nop */
174 #define DRIVERNAME(d)			/* nop */
175 #define DEVCLANAME(d)			/* nop */
176 
177 #define print_device_short(d,i)		/* nop */
178 #define print_device(d,i)		/* nop */
179 #define print_device_tree_short(d,i)	/* nop */
180 #define print_device_tree(d,i)		/* nop */
181 #define print_driver_short(d,i)		/* nop */
182 #define print_driver(d,i)		/* nop */
183 #define print_driver_list(d,i)		/* nop */
184 #define print_devclass_short(d,i)	/* nop */
185 #define print_devclass(d,i)		/* nop */
186 #define print_devclass_list_short()	/* nop */
187 #define print_devclass_list()		/* nop */
188 #endif
189 
190 /*
191  * dev sysctl tree
192  */
193 
194 enum {
195 	DEVCLASS_SYSCTL_PARENT,
196 };
197 
198 static int
199 devclass_sysctl_handler(SYSCTL_HANDLER_ARGS)
200 {
201 	devclass_t dc = (devclass_t)arg1;
202 	const char *value;
203 
204 	switch (arg2) {
205 	case DEVCLASS_SYSCTL_PARENT:
206 		value = dc->parent ? dc->parent->name : "";
207 		break;
208 	default:
209 		return (EINVAL);
210 	}
211 	return (SYSCTL_OUT(req, value, strlen(value)));
212 }
213 
214 static void
215 devclass_sysctl_init(devclass_t dc)
216 {
217 
218 	if (dc->sysctl_tree != NULL)
219 		return;
220 	sysctl_ctx_init(&dc->sysctl_ctx);
221 	dc->sysctl_tree = SYSCTL_ADD_NODE(&dc->sysctl_ctx,
222 	    SYSCTL_STATIC_CHILDREN(_dev), OID_AUTO, dc->name,
223 	    CTLFLAG_RD, 0, "");
224 	SYSCTL_ADD_PROC(&dc->sysctl_ctx, SYSCTL_CHILDREN(dc->sysctl_tree),
225 	    OID_AUTO, "%parent", CTLFLAG_RD,
226 	    dc, DEVCLASS_SYSCTL_PARENT, devclass_sysctl_handler, "A",
227 	    "parent class");
228 }
229 
230 enum {
231 	DEVICE_SYSCTL_DESC,
232 	DEVICE_SYSCTL_DRIVER,
233 	DEVICE_SYSCTL_LOCATION,
234 	DEVICE_SYSCTL_PNPINFO,
235 	DEVICE_SYSCTL_PARENT,
236 };
237 
238 static int
239 device_sysctl_handler(SYSCTL_HANDLER_ARGS)
240 {
241 	device_t dev = (device_t)arg1;
242 	const char *value;
243 	char *buf;
244 	int error;
245 
246 	buf = NULL;
247 	switch (arg2) {
248 	case DEVICE_SYSCTL_DESC:
249 		value = dev->desc ? dev->desc : "";
250 		break;
251 	case DEVICE_SYSCTL_DRIVER:
252 		value = dev->driver ? dev->driver->name : "";
253 		break;
254 	case DEVICE_SYSCTL_LOCATION:
255 		value = buf = malloc(1024, M_BUS, M_WAITOK | M_ZERO);
256 		bus_child_location_str(dev, buf, 1024);
257 		break;
258 	case DEVICE_SYSCTL_PNPINFO:
259 		value = buf = malloc(1024, M_BUS, M_WAITOK | M_ZERO);
260 		bus_child_pnpinfo_str(dev, buf, 1024);
261 		break;
262 	case DEVICE_SYSCTL_PARENT:
263 		value = dev->parent ? dev->parent->nameunit : "";
264 		break;
265 	default:
266 		return (EINVAL);
267 	}
268 	error = SYSCTL_OUT(req, value, strlen(value));
269 	if (buf != NULL)
270 		free(buf, M_BUS);
271 	return (error);
272 }
273 
274 static void
275 device_sysctl_init(device_t dev)
276 {
277 	devclass_t dc = dev->devclass;
278 
279 	if (dev->sysctl_tree != NULL)
280 		return;
281 	devclass_sysctl_init(dc);
282 	sysctl_ctx_init(&dev->sysctl_ctx);
283 	dev->sysctl_tree = SYSCTL_ADD_NODE(&dev->sysctl_ctx,
284 	    SYSCTL_CHILDREN(dc->sysctl_tree), OID_AUTO,
285 	    dev->nameunit + strlen(dc->name),
286 	    CTLFLAG_RD, 0, "");
287 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
288 	    OID_AUTO, "%desc", CTLFLAG_RD,
289 	    dev, DEVICE_SYSCTL_DESC, device_sysctl_handler, "A",
290 	    "device description");
291 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
292 	    OID_AUTO, "%driver", CTLFLAG_RD,
293 	    dev, DEVICE_SYSCTL_DRIVER, device_sysctl_handler, "A",
294 	    "device driver name");
295 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
296 	    OID_AUTO, "%location", CTLFLAG_RD,
297 	    dev, DEVICE_SYSCTL_LOCATION, device_sysctl_handler, "A",
298 	    "device location relative to parent");
299 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
300 	    OID_AUTO, "%pnpinfo", CTLFLAG_RD,
301 	    dev, DEVICE_SYSCTL_PNPINFO, device_sysctl_handler, "A",
302 	    "device identification");
303 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
304 	    OID_AUTO, "%parent", CTLFLAG_RD,
305 	    dev, DEVICE_SYSCTL_PARENT, device_sysctl_handler, "A",
306 	    "parent device");
307 }
308 
309 static void
310 device_sysctl_update(device_t dev)
311 {
312 	devclass_t dc = dev->devclass;
313 
314 	if (dev->sysctl_tree == NULL)
315 		return;
316 	sysctl_rename_oid(dev->sysctl_tree, dev->nameunit + strlen(dc->name));
317 }
318 
319 static void
320 device_sysctl_fini(device_t dev)
321 {
322 	if (dev->sysctl_tree == NULL)
323 		return;
324 	sysctl_ctx_free(&dev->sysctl_ctx);
325 	dev->sysctl_tree = NULL;
326 }
327 
328 /*
329  * /dev/devctl implementation
330  */
331 
332 /*
333  * This design allows only one reader for /dev/devctl.  This is not desirable
334  * in the long run, but will get a lot of hair out of this implementation.
335  * Maybe we should make this device a clonable device.
336  *
337  * Also note: we specifically do not attach a device to the device_t tree
338  * to avoid potential chicken and egg problems.  One could argue that all
339  * of this belongs to the root node.  One could also further argue that the
340  * sysctl interface that we have not might more properly be an ioctl
341  * interface, but at this stage of the game, I'm not inclined to rock that
342  * boat.
343  *
344  * I'm also not sure that the SIGIO support is done correctly or not, as
345  * I copied it from a driver that had SIGIO support that likely hasn't been
346  * tested since 3.4 or 2.2.8!
347  */
348 
349 static int sysctl_devctl_disable(SYSCTL_HANDLER_ARGS);
350 static int devctl_disable = 0;
351 TUNABLE_INT("hw.bus.devctl_disable", &devctl_disable);
352 SYSCTL_PROC(_hw_bus, OID_AUTO, devctl_disable, CTLTYPE_INT | CTLFLAG_RW, 0, 0,
353     sysctl_devctl_disable, "I", "devctl disable");
354 
355 static d_open_t		devopen;
356 static d_close_t	devclose;
357 static d_read_t		devread;
358 static d_ioctl_t	devioctl;
359 static d_poll_t		devpoll;
360 
361 static struct cdevsw dev_cdevsw = {
362 	.d_version =	D_VERSION,
363 	.d_flags =	D_NEEDGIANT,
364 	.d_open =	devopen,
365 	.d_close =	devclose,
366 	.d_read =	devread,
367 	.d_ioctl =	devioctl,
368 	.d_poll =	devpoll,
369 	.d_name =	"devctl",
370 };
371 
372 struct dev_event_info
373 {
374 	char *dei_data;
375 	TAILQ_ENTRY(dev_event_info) dei_link;
376 };
377 
378 TAILQ_HEAD(devq, dev_event_info);
379 
380 static struct dev_softc
381 {
382 	int	inuse;
383 	int	nonblock;
384 	struct mtx mtx;
385 	struct cv cv;
386 	struct selinfo sel;
387 	struct devq devq;
388 	struct proc *async_proc;
389 } devsoftc;
390 
391 static struct cdev *devctl_dev;
392 
393 static void
394 devinit(void)
395 {
396 	devctl_dev = make_dev(&dev_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600,
397 	    "devctl");
398 	mtx_init(&devsoftc.mtx, "dev mtx", "devd", MTX_DEF);
399 	cv_init(&devsoftc.cv, "dev cv");
400 	TAILQ_INIT(&devsoftc.devq);
401 }
402 
403 static int
404 devopen(struct cdev *dev, int oflags, int devtype, d_thread_t *td)
405 {
406 	if (devsoftc.inuse)
407 		return (EBUSY);
408 	/* move to init */
409 	devsoftc.inuse = 1;
410 	devsoftc.nonblock = 0;
411 	devsoftc.async_proc = NULL;
412 	return (0);
413 }
414 
415 static int
416 devclose(struct cdev *dev, int fflag, int devtype, d_thread_t *td)
417 {
418 	devsoftc.inuse = 0;
419 	mtx_lock(&devsoftc.mtx);
420 	cv_broadcast(&devsoftc.cv);
421 	mtx_unlock(&devsoftc.mtx);
422 
423 	return (0);
424 }
425 
426 /*
427  * The read channel for this device is used to report changes to
428  * userland in realtime.  We are required to free the data as well as
429  * the n1 object because we allocate them separately.  Also note that
430  * we return one record at a time.  If you try to read this device a
431  * character at a time, you will lose the rest of the data.  Listening
432  * programs are expected to cope.
433  */
434 static int
435 devread(struct cdev *dev, struct uio *uio, int ioflag)
436 {
437 	struct dev_event_info *n1;
438 	int rv;
439 
440 	mtx_lock(&devsoftc.mtx);
441 	while (TAILQ_EMPTY(&devsoftc.devq)) {
442 		if (devsoftc.nonblock) {
443 			mtx_unlock(&devsoftc.mtx);
444 			return (EAGAIN);
445 		}
446 		rv = cv_wait_sig(&devsoftc.cv, &devsoftc.mtx);
447 		if (rv) {
448 			/*
449 			 * Need to translate ERESTART to EINTR here? -- jake
450 			 */
451 			mtx_unlock(&devsoftc.mtx);
452 			return (rv);
453 		}
454 	}
455 	n1 = TAILQ_FIRST(&devsoftc.devq);
456 	TAILQ_REMOVE(&devsoftc.devq, n1, dei_link);
457 	mtx_unlock(&devsoftc.mtx);
458 	rv = uiomove(n1->dei_data, strlen(n1->dei_data), uio);
459 	free(n1->dei_data, M_BUS);
460 	free(n1, M_BUS);
461 	return (rv);
462 }
463 
464 static	int
465 devioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, d_thread_t *td)
466 {
467 	switch (cmd) {
468 
469 	case FIONBIO:
470 		if (*(int*)data)
471 			devsoftc.nonblock = 1;
472 		else
473 			devsoftc.nonblock = 0;
474 		return (0);
475 	case FIOASYNC:
476 		if (*(int*)data)
477 			devsoftc.async_proc = td->td_proc;
478 		else
479 			devsoftc.async_proc = NULL;
480 		return (0);
481 
482 		/* (un)Support for other fcntl() calls. */
483 	case FIOCLEX:
484 	case FIONCLEX:
485 	case FIONREAD:
486 	case FIOSETOWN:
487 	case FIOGETOWN:
488 	default:
489 		break;
490 	}
491 	return (ENOTTY);
492 }
493 
494 static	int
495 devpoll(struct cdev *dev, int events, d_thread_t *td)
496 {
497 	int	revents = 0;
498 
499 	mtx_lock(&devsoftc.mtx);
500 	if (events & (POLLIN | POLLRDNORM)) {
501 		if (!TAILQ_EMPTY(&devsoftc.devq))
502 			revents = events & (POLLIN | POLLRDNORM);
503 		else
504 			selrecord(td, &devsoftc.sel);
505 	}
506 	mtx_unlock(&devsoftc.mtx);
507 
508 	return (revents);
509 }
510 
511 /**
512  * @brief Return whether the userland process is running
513  */
514 boolean_t
515 devctl_process_running(void)
516 {
517 	return (devsoftc.async_proc != NULL);
518 }
519 
520 /**
521  * @brief Queue data to be read from the devctl device
522  *
523  * Generic interface to queue data to the devctl device.  It is
524  * assumed that @p data is properly formatted.  It is further assumed
525  * that @p data is allocated using the M_BUS malloc type.
526  */
527 void
528 devctl_queue_data(char *data)
529 {
530 	struct dev_event_info *n1 = NULL;
531 	struct proc *p;
532 
533 	n1 = malloc(sizeof(*n1), M_BUS, M_NOWAIT);
534 	if (n1 == NULL)
535 		return;
536 	n1->dei_data = data;
537 	mtx_lock(&devsoftc.mtx);
538 	TAILQ_INSERT_TAIL(&devsoftc.devq, n1, dei_link);
539 	cv_broadcast(&devsoftc.cv);
540 	mtx_unlock(&devsoftc.mtx);
541 	selwakeup(&devsoftc.sel);
542 	p = devsoftc.async_proc;
543 	if (p != NULL) {
544 		PROC_LOCK(p);
545 		psignal(p, SIGIO);
546 		PROC_UNLOCK(p);
547 	}
548 }
549 
550 /**
551  * @brief Send a 'notification' to userland, using standard ways
552  */
553 void
554 devctl_notify(const char *system, const char *subsystem, const char *type,
555     const char *data)
556 {
557 	int len = 0;
558 	char *msg;
559 
560 	if (system == NULL)
561 		return;		/* BOGUS!  Must specify system. */
562 	if (subsystem == NULL)
563 		return;		/* BOGUS!  Must specify subsystem. */
564 	if (type == NULL)
565 		return;		/* BOGUS!  Must specify type. */
566 	len += strlen(" system=") + strlen(system);
567 	len += strlen(" subsystem=") + strlen(subsystem);
568 	len += strlen(" type=") + strlen(type);
569 	/* add in the data message plus newline. */
570 	if (data != NULL)
571 		len += strlen(data);
572 	len += 3;	/* '!', '\n', and NUL */
573 	msg = malloc(len, M_BUS, M_NOWAIT);
574 	if (msg == NULL)
575 		return;		/* Drop it on the floor */
576 	if (data != NULL)
577 		snprintf(msg, len, "!system=%s subsystem=%s type=%s %s\n",
578 		    system, subsystem, type, data);
579 	else
580 		snprintf(msg, len, "!system=%s subsystem=%s type=%s\n",
581 		    system, subsystem, type);
582 	devctl_queue_data(msg);
583 }
584 
585 /*
586  * Common routine that tries to make sending messages as easy as possible.
587  * We allocate memory for the data, copy strings into that, but do not
588  * free it unless there's an error.  The dequeue part of the driver should
589  * free the data.  We don't send data when the device is disabled.  We do
590  * send data, even when we have no listeners, because we wish to avoid
591  * races relating to startup and restart of listening applications.
592  *
593  * devaddq is designed to string together the type of event, with the
594  * object of that event, plus the plug and play info and location info
595  * for that event.  This is likely most useful for devices, but less
596  * useful for other consumers of this interface.  Those should use
597  * the devctl_queue_data() interface instead.
598  */
599 static void
600 devaddq(const char *type, const char *what, device_t dev)
601 {
602 	char *data = NULL;
603 	char *loc = NULL;
604 	char *pnp = NULL;
605 	const char *parstr;
606 
607 	if (devctl_disable)
608 		return;
609 	data = malloc(1024, M_BUS, M_NOWAIT);
610 	if (data == NULL)
611 		goto bad;
612 
613 	/* get the bus specific location of this device */
614 	loc = malloc(1024, M_BUS, M_NOWAIT);
615 	if (loc == NULL)
616 		goto bad;
617 	*loc = '\0';
618 	bus_child_location_str(dev, loc, 1024);
619 
620 	/* Get the bus specific pnp info of this device */
621 	pnp = malloc(1024, M_BUS, M_NOWAIT);
622 	if (pnp == NULL)
623 		goto bad;
624 	*pnp = '\0';
625 	bus_child_pnpinfo_str(dev, pnp, 1024);
626 
627 	/* Get the parent of this device, or / if high enough in the tree. */
628 	if (device_get_parent(dev) == NULL)
629 		parstr = ".";	/* Or '/' ? */
630 	else
631 		parstr = device_get_nameunit(device_get_parent(dev));
632 	/* String it all together. */
633 	snprintf(data, 1024, "%s%s at %s %s on %s\n", type, what, loc, pnp,
634 	  parstr);
635 	free(loc, M_BUS);
636 	free(pnp, M_BUS);
637 	devctl_queue_data(data);
638 	return;
639 bad:
640 	free(pnp, M_BUS);
641 	free(loc, M_BUS);
642 	free(data, M_BUS);
643 	return;
644 }
645 
646 /*
647  * A device was added to the tree.  We are called just after it successfully
648  * attaches (that is, probe and attach success for this device).  No call
649  * is made if a device is merely parented into the tree.  See devnomatch
650  * if probe fails.  If attach fails, no notification is sent (but maybe
651  * we should have a different message for this).
652  */
653 static void
654 devadded(device_t dev)
655 {
656 	char *pnp = NULL;
657 	char *tmp = NULL;
658 
659 	pnp = malloc(1024, M_BUS, M_NOWAIT);
660 	if (pnp == NULL)
661 		goto fail;
662 	tmp = malloc(1024, M_BUS, M_NOWAIT);
663 	if (tmp == NULL)
664 		goto fail;
665 	*pnp = '\0';
666 	bus_child_pnpinfo_str(dev, pnp, 1024);
667 	snprintf(tmp, 1024, "%s %s", device_get_nameunit(dev), pnp);
668 	devaddq("+", tmp, dev);
669 fail:
670 	if (pnp != NULL)
671 		free(pnp, M_BUS);
672 	if (tmp != NULL)
673 		free(tmp, M_BUS);
674 	return;
675 }
676 
677 /*
678  * A device was removed from the tree.  We are called just before this
679  * happens.
680  */
681 static void
682 devremoved(device_t dev)
683 {
684 	char *pnp = NULL;
685 	char *tmp = NULL;
686 
687 	pnp = malloc(1024, M_BUS, M_NOWAIT);
688 	if (pnp == NULL)
689 		goto fail;
690 	tmp = malloc(1024, M_BUS, M_NOWAIT);
691 	if (tmp == NULL)
692 		goto fail;
693 	*pnp = '\0';
694 	bus_child_pnpinfo_str(dev, pnp, 1024);
695 	snprintf(tmp, 1024, "%s %s", device_get_nameunit(dev), pnp);
696 	devaddq("-", tmp, dev);
697 fail:
698 	if (pnp != NULL)
699 		free(pnp, M_BUS);
700 	if (tmp != NULL)
701 		free(tmp, M_BUS);
702 	return;
703 }
704 
705 /*
706  * Called when there's no match for this device.  This is only called
707  * the first time that no match happens, so we don't keep getitng this
708  * message.  Should that prove to be undesirable, we can change it.
709  * This is called when all drivers that can attach to a given bus
710  * decline to accept this device.  Other errrors may not be detected.
711  */
712 static void
713 devnomatch(device_t dev)
714 {
715 	devaddq("?", "", dev);
716 }
717 
718 static int
719 sysctl_devctl_disable(SYSCTL_HANDLER_ARGS)
720 {
721 	struct dev_event_info *n1;
722 	int dis, error;
723 
724 	dis = devctl_disable;
725 	error = sysctl_handle_int(oidp, &dis, 0, req);
726 	if (error || !req->newptr)
727 		return (error);
728 	mtx_lock(&devsoftc.mtx);
729 	devctl_disable = dis;
730 	if (dis) {
731 		while (!TAILQ_EMPTY(&devsoftc.devq)) {
732 			n1 = TAILQ_FIRST(&devsoftc.devq);
733 			TAILQ_REMOVE(&devsoftc.devq, n1, dei_link);
734 			free(n1->dei_data, M_BUS);
735 			free(n1, M_BUS);
736 		}
737 	}
738 	mtx_unlock(&devsoftc.mtx);
739 	return (0);
740 }
741 
742 /* End of /dev/devctl code */
743 
744 TAILQ_HEAD(,device)	bus_data_devices;
745 static int bus_data_generation = 1;
746 
747 kobj_method_t null_methods[] = {
748 	{ 0, 0 }
749 };
750 
751 DEFINE_CLASS(null, null_methods, 0);
752 
753 /*
754  * Devclass implementation
755  */
756 
757 static devclass_list_t devclasses = TAILQ_HEAD_INITIALIZER(devclasses);
758 
759 
760 /**
761  * @internal
762  * @brief Find or create a device class
763  *
764  * If a device class with the name @p classname exists, return it,
765  * otherwise if @p create is non-zero create and return a new device
766  * class.
767  *
768  * If @p parentname is non-NULL, the parent of the devclass is set to
769  * the devclass of that name.
770  *
771  * @param classname	the devclass name to find or create
772  * @param parentname	the parent devclass name or @c NULL
773  * @param create	non-zero to create a devclass
774  */
775 static devclass_t
776 devclass_find_internal(const char *classname, const char *parentname,
777 		       int create)
778 {
779 	devclass_t dc;
780 
781 	PDEBUG(("looking for %s", classname));
782 	if (!classname)
783 		return (NULL);
784 
785 	TAILQ_FOREACH(dc, &devclasses, link) {
786 		if (!strcmp(dc->name, classname))
787 			break;
788 	}
789 
790 	if (create && !dc) {
791 		PDEBUG(("creating %s", classname));
792 		dc = malloc(sizeof(struct devclass) + strlen(classname) + 1,
793 		    M_BUS, M_NOWAIT|M_ZERO);
794 		if (!dc)
795 			return (NULL);
796 		dc->parent = NULL;
797 		dc->name = (char*) (dc + 1);
798 		strcpy(dc->name, classname);
799 		TAILQ_INIT(&dc->drivers);
800 		TAILQ_INSERT_TAIL(&devclasses, dc, link);
801 
802 		bus_data_generation_update();
803 	}
804 
805 	/*
806 	 * If a parent class is specified, then set that as our parent so
807 	 * that this devclass will support drivers for the parent class as
808 	 * well.  If the parent class has the same name don't do this though
809 	 * as it creates a cycle that can trigger an infinite loop in
810 	 * device_probe_child() if a device exists for which there is no
811 	 * suitable driver.
812 	 */
813 	if (parentname && dc && !dc->parent &&
814 	    strcmp(classname, parentname) != 0) {
815 		dc->parent = devclass_find_internal(parentname, NULL, FALSE);
816 	}
817 
818 	return (dc);
819 }
820 
821 /**
822  * @brief Create a device class
823  *
824  * If a device class with the name @p classname exists, return it,
825  * otherwise create and return a new device class.
826  *
827  * @param classname	the devclass name to find or create
828  */
829 devclass_t
830 devclass_create(const char *classname)
831 {
832 	return (devclass_find_internal(classname, NULL, TRUE));
833 }
834 
835 /**
836  * @brief Find a device class
837  *
838  * If a device class with the name @p classname exists, return it,
839  * otherwise return @c NULL.
840  *
841  * @param classname	the devclass name to find
842  */
843 devclass_t
844 devclass_find(const char *classname)
845 {
846 	return (devclass_find_internal(classname, NULL, FALSE));
847 }
848 
849 /**
850  * @brief Add a device driver to a device class
851  *
852  * Add a device driver to a devclass. This is normally called
853  * automatically by DRIVER_MODULE(). The BUS_DRIVER_ADDED() method of
854  * all devices in the devclass will be called to allow them to attempt
855  * to re-probe any unmatched children.
856  *
857  * @param dc		the devclass to edit
858  * @param driver	the driver to register
859  */
860 int
861 devclass_add_driver(devclass_t dc, driver_t *driver)
862 {
863 	driverlink_t dl;
864 	int i;
865 
866 	PDEBUG(("%s", DRIVERNAME(driver)));
867 
868 	dl = malloc(sizeof *dl, M_BUS, M_NOWAIT|M_ZERO);
869 	if (!dl)
870 		return (ENOMEM);
871 
872 	/*
873 	 * Compile the driver's methods. Also increase the reference count
874 	 * so that the class doesn't get freed when the last instance
875 	 * goes. This means we can safely use static methods and avoids a
876 	 * double-free in devclass_delete_driver.
877 	 */
878 	kobj_class_compile((kobj_class_t) driver);
879 
880 	/*
881 	 * Make sure the devclass which the driver is implementing exists.
882 	 */
883 	devclass_find_internal(driver->name, NULL, TRUE);
884 
885 	dl->driver = driver;
886 	TAILQ_INSERT_TAIL(&dc->drivers, dl, link);
887 	driver->refs++;		/* XXX: kobj_mtx */
888 
889 	/*
890 	 * Call BUS_DRIVER_ADDED for any existing busses in this class.
891 	 */
892 	for (i = 0; i < dc->maxunit; i++)
893 		if (dc->devices[i])
894 			BUS_DRIVER_ADDED(dc->devices[i], driver);
895 
896 	bus_data_generation_update();
897 	return (0);
898 }
899 
900 /**
901  * @brief Delete a device driver from a device class
902  *
903  * Delete a device driver from a devclass. This is normally called
904  * automatically by DRIVER_MODULE().
905  *
906  * If the driver is currently attached to any devices,
907  * devclass_delete_driver() will first attempt to detach from each
908  * device. If one of the detach calls fails, the driver will not be
909  * deleted.
910  *
911  * @param dc		the devclass to edit
912  * @param driver	the driver to unregister
913  */
914 int
915 devclass_delete_driver(devclass_t busclass, driver_t *driver)
916 {
917 	devclass_t dc = devclass_find(driver->name);
918 	driverlink_t dl;
919 	device_t dev;
920 	int i;
921 	int error;
922 
923 	PDEBUG(("%s from devclass %s", driver->name, DEVCLANAME(busclass)));
924 
925 	if (!dc)
926 		return (0);
927 
928 	/*
929 	 * Find the link structure in the bus' list of drivers.
930 	 */
931 	TAILQ_FOREACH(dl, &busclass->drivers, link) {
932 		if (dl->driver == driver)
933 			break;
934 	}
935 
936 	if (!dl) {
937 		PDEBUG(("%s not found in %s list", driver->name,
938 		    busclass->name));
939 		return (ENOENT);
940 	}
941 
942 	/*
943 	 * Disassociate from any devices.  We iterate through all the
944 	 * devices in the devclass of the driver and detach any which are
945 	 * using the driver and which have a parent in the devclass which
946 	 * we are deleting from.
947 	 *
948 	 * Note that since a driver can be in multiple devclasses, we
949 	 * should not detach devices which are not children of devices in
950 	 * the affected devclass.
951 	 */
952 	for (i = 0; i < dc->maxunit; i++) {
953 		if (dc->devices[i]) {
954 			dev = dc->devices[i];
955 			if (dev->driver == driver && dev->parent &&
956 			    dev->parent->devclass == busclass) {
957 				if ((error = device_detach(dev)) != 0)
958 					return (error);
959 				device_set_driver(dev, NULL);
960 			}
961 		}
962 	}
963 
964 	TAILQ_REMOVE(&busclass->drivers, dl, link);
965 	free(dl, M_BUS);
966 
967 	/* XXX: kobj_mtx */
968 	driver->refs--;
969 	if (driver->refs == 0)
970 		kobj_class_free((kobj_class_t) driver);
971 
972 	bus_data_generation_update();
973 	return (0);
974 }
975 
976 /**
977  * @brief Quiesces a set of device drivers from a device class
978  *
979  * Quiesce a device driver from a devclass. This is normally called
980  * automatically by DRIVER_MODULE().
981  *
982  * If the driver is currently attached to any devices,
983  * devclass_quiesece_driver() will first attempt to quiesce each
984  * device.
985  *
986  * @param dc		the devclass to edit
987  * @param driver	the driver to unregister
988  */
989 int
990 devclass_quiesce_driver(devclass_t busclass, driver_t *driver)
991 {
992 	devclass_t dc = devclass_find(driver->name);
993 	driverlink_t dl;
994 	device_t dev;
995 	int i;
996 	int error;
997 
998 	PDEBUG(("%s from devclass %s", driver->name, DEVCLANAME(busclass)));
999 
1000 	if (!dc)
1001 		return (0);
1002 
1003 	/*
1004 	 * Find the link structure in the bus' list of drivers.
1005 	 */
1006 	TAILQ_FOREACH(dl, &busclass->drivers, link) {
1007 		if (dl->driver == driver)
1008 			break;
1009 	}
1010 
1011 	if (!dl) {
1012 		PDEBUG(("%s not found in %s list", driver->name,
1013 		    busclass->name));
1014 		return (ENOENT);
1015 	}
1016 
1017 	/*
1018 	 * Quiesce all devices.  We iterate through all the devices in
1019 	 * the devclass of the driver and quiesce any which are using
1020 	 * the driver and which have a parent in the devclass which we
1021 	 * are quiescing.
1022 	 *
1023 	 * Note that since a driver can be in multiple devclasses, we
1024 	 * should not quiesce devices which are not children of
1025 	 * devices in the affected devclass.
1026 	 */
1027 	for (i = 0; i < dc->maxunit; i++) {
1028 		if (dc->devices[i]) {
1029 			dev = dc->devices[i];
1030 			if (dev->driver == driver && dev->parent &&
1031 			    dev->parent->devclass == busclass) {
1032 				if ((error = device_quiesce(dev)) != 0)
1033 					return (error);
1034 			}
1035 		}
1036 	}
1037 
1038 	return (0);
1039 }
1040 
1041 /**
1042  * @internal
1043  */
1044 static driverlink_t
1045 devclass_find_driver_internal(devclass_t dc, const char *classname)
1046 {
1047 	driverlink_t dl;
1048 
1049 	PDEBUG(("%s in devclass %s", classname, DEVCLANAME(dc)));
1050 
1051 	TAILQ_FOREACH(dl, &dc->drivers, link) {
1052 		if (!strcmp(dl->driver->name, classname))
1053 			return (dl);
1054 	}
1055 
1056 	PDEBUG(("not found"));
1057 	return (NULL);
1058 }
1059 
1060 /**
1061  * @brief Search a devclass for a driver
1062  *
1063  * This function searches the devclass's list of drivers and returns
1064  * the first driver whose name is @p classname or @c NULL if there is
1065  * no driver of that name.
1066  *
1067  * @param dc		the devclass to search
1068  * @param classname	the driver name to search for
1069  */
1070 kobj_class_t
1071 devclass_find_driver(devclass_t dc, const char *classname)
1072 {
1073 	driverlink_t dl;
1074 
1075 	dl = devclass_find_driver_internal(dc, classname);
1076 	if (dl)
1077 		return (dl->driver);
1078 	return (NULL);
1079 }
1080 
1081 /**
1082  * @brief Return the name of the devclass
1083  */
1084 const char *
1085 devclass_get_name(devclass_t dc)
1086 {
1087 	return (dc->name);
1088 }
1089 
1090 /**
1091  * @brief Find a device given a unit number
1092  *
1093  * @param dc		the devclass to search
1094  * @param unit		the unit number to search for
1095  *
1096  * @returns		the device with the given unit number or @c
1097  *			NULL if there is no such device
1098  */
1099 device_t
1100 devclass_get_device(devclass_t dc, int unit)
1101 {
1102 	if (dc == NULL || unit < 0 || unit >= dc->maxunit)
1103 		return (NULL);
1104 	return (dc->devices[unit]);
1105 }
1106 
1107 /**
1108  * @brief Find the softc field of a device given a unit number
1109  *
1110  * @param dc		the devclass to search
1111  * @param unit		the unit number to search for
1112  *
1113  * @returns		the softc field of the device with the given
1114  *			unit number or @c NULL if there is no such
1115  *			device
1116  */
1117 void *
1118 devclass_get_softc(devclass_t dc, int unit)
1119 {
1120 	device_t dev;
1121 
1122 	dev = devclass_get_device(dc, unit);
1123 	if (!dev)
1124 		return (NULL);
1125 
1126 	return (device_get_softc(dev));
1127 }
1128 
1129 /**
1130  * @brief Get a list of devices in the devclass
1131  *
1132  * An array containing a list of all the devices in the given devclass
1133  * is allocated and returned in @p *devlistp. The number of devices
1134  * in the array is returned in @p *devcountp. The caller should free
1135  * the array using @c free(p, M_TEMP), even if @p *devcountp is 0.
1136  *
1137  * @param dc		the devclass to examine
1138  * @param devlistp	points at location for array pointer return
1139  *			value
1140  * @param devcountp	points at location for array size return value
1141  *
1142  * @retval 0		success
1143  * @retval ENOMEM	the array allocation failed
1144  */
1145 int
1146 devclass_get_devices(devclass_t dc, device_t **devlistp, int *devcountp)
1147 {
1148 	int count, i;
1149 	device_t *list;
1150 
1151 	count = devclass_get_count(dc);
1152 	list = malloc(count * sizeof(device_t), M_TEMP, M_NOWAIT|M_ZERO);
1153 	if (!list)
1154 		return (ENOMEM);
1155 
1156 	count = 0;
1157 	for (i = 0; i < dc->maxunit; i++) {
1158 		if (dc->devices[i]) {
1159 			list[count] = dc->devices[i];
1160 			count++;
1161 		}
1162 	}
1163 
1164 	*devlistp = list;
1165 	*devcountp = count;
1166 
1167 	return (0);
1168 }
1169 
1170 /**
1171  * @brief Get a list of drivers in the devclass
1172  *
1173  * An array containing a list of pointers to all the drivers in the
1174  * given devclass is allocated and returned in @p *listp.  The number
1175  * of drivers in the array is returned in @p *countp. The caller should
1176  * free the array using @c free(p, M_TEMP).
1177  *
1178  * @param dc		the devclass to examine
1179  * @param listp		gives location for array pointer return value
1180  * @param countp	gives location for number of array elements
1181  *			return value
1182  *
1183  * @retval 0		success
1184  * @retval ENOMEM	the array allocation failed
1185  */
1186 int
1187 devclass_get_drivers(devclass_t dc, driver_t ***listp, int *countp)
1188 {
1189 	driverlink_t dl;
1190 	driver_t **list;
1191 	int count;
1192 
1193 	count = 0;
1194 	TAILQ_FOREACH(dl, &dc->drivers, link)
1195 		count++;
1196 	list = malloc(count * sizeof(driver_t *), M_TEMP, M_NOWAIT);
1197 	if (list == NULL)
1198 		return (ENOMEM);
1199 
1200 	count = 0;
1201 	TAILQ_FOREACH(dl, &dc->drivers, link) {
1202 		list[count] = dl->driver;
1203 		count++;
1204 	}
1205 	*listp = list;
1206 	*countp = count;
1207 
1208 	return (0);
1209 }
1210 
1211 /**
1212  * @brief Get the number of devices in a devclass
1213  *
1214  * @param dc		the devclass to examine
1215  */
1216 int
1217 devclass_get_count(devclass_t dc)
1218 {
1219 	int count, i;
1220 
1221 	count = 0;
1222 	for (i = 0; i < dc->maxunit; i++)
1223 		if (dc->devices[i])
1224 			count++;
1225 	return (count);
1226 }
1227 
1228 /**
1229  * @brief Get the maximum unit number used in a devclass
1230  *
1231  * Note that this is one greater than the highest currently-allocated
1232  * unit.  If a null devclass_t is passed in, -1 is returned to indicate
1233  * that not even the devclass has been allocated yet.
1234  *
1235  * @param dc		the devclass to examine
1236  */
1237 int
1238 devclass_get_maxunit(devclass_t dc)
1239 {
1240 	if (dc == NULL)
1241 		return (-1);
1242 	return (dc->maxunit);
1243 }
1244 
1245 /**
1246  * @brief Find a free unit number in a devclass
1247  *
1248  * This function searches for the first unused unit number greater
1249  * that or equal to @p unit.
1250  *
1251  * @param dc		the devclass to examine
1252  * @param unit		the first unit number to check
1253  */
1254 int
1255 devclass_find_free_unit(devclass_t dc, int unit)
1256 {
1257 	if (dc == NULL)
1258 		return (unit);
1259 	while (unit < dc->maxunit && dc->devices[unit] != NULL)
1260 		unit++;
1261 	return (unit);
1262 }
1263 
1264 /**
1265  * @brief Set the parent of a devclass
1266  *
1267  * The parent class is normally initialised automatically by
1268  * DRIVER_MODULE().
1269  *
1270  * @param dc		the devclass to edit
1271  * @param pdc		the new parent devclass
1272  */
1273 void
1274 devclass_set_parent(devclass_t dc, devclass_t pdc)
1275 {
1276 	dc->parent = pdc;
1277 }
1278 
1279 /**
1280  * @brief Get the parent of a devclass
1281  *
1282  * @param dc		the devclass to examine
1283  */
1284 devclass_t
1285 devclass_get_parent(devclass_t dc)
1286 {
1287 	return (dc->parent);
1288 }
1289 
1290 struct sysctl_ctx_list *
1291 devclass_get_sysctl_ctx(devclass_t dc)
1292 {
1293 	return (&dc->sysctl_ctx);
1294 }
1295 
1296 struct sysctl_oid *
1297 devclass_get_sysctl_tree(devclass_t dc)
1298 {
1299 	return (dc->sysctl_tree);
1300 }
1301 
1302 /**
1303  * @internal
1304  * @brief Allocate a unit number
1305  *
1306  * On entry, @p *unitp is the desired unit number (or @c -1 if any
1307  * will do). The allocated unit number is returned in @p *unitp.
1308 
1309  * @param dc		the devclass to allocate from
1310  * @param unitp		points at the location for the allocated unit
1311  *			number
1312  *
1313  * @retval 0		success
1314  * @retval EEXIST	the requested unit number is already allocated
1315  * @retval ENOMEM	memory allocation failure
1316  */
1317 static int
1318 devclass_alloc_unit(devclass_t dc, int *unitp)
1319 {
1320 	int unit = *unitp;
1321 
1322 	PDEBUG(("unit %d in devclass %s", unit, DEVCLANAME(dc)));
1323 
1324 	/* If we were given a wired unit number, check for existing device */
1325 	/* XXX imp XXX */
1326 	if (unit != -1) {
1327 		if (unit >= 0 && unit < dc->maxunit &&
1328 		    dc->devices[unit] != NULL) {
1329 			if (bootverbose)
1330 				printf("%s: %s%d already exists; skipping it\n",
1331 				    dc->name, dc->name, *unitp);
1332 			return (EEXIST);
1333 		}
1334 	} else {
1335 		/* Unwired device, find the next available slot for it */
1336 		unit = 0;
1337 		while (unit < dc->maxunit && dc->devices[unit] != NULL)
1338 			unit++;
1339 	}
1340 
1341 	/*
1342 	 * We've selected a unit beyond the length of the table, so let's
1343 	 * extend the table to make room for all units up to and including
1344 	 * this one.
1345 	 */
1346 	if (unit >= dc->maxunit) {
1347 		device_t *newlist;
1348 		int newsize;
1349 
1350 		newsize = roundup((unit + 1), MINALLOCSIZE / sizeof(device_t));
1351 		newlist = malloc(sizeof(device_t) * newsize, M_BUS, M_NOWAIT);
1352 		if (!newlist)
1353 			return (ENOMEM);
1354 		bcopy(dc->devices, newlist, sizeof(device_t) * dc->maxunit);
1355 		bzero(newlist + dc->maxunit,
1356 		    sizeof(device_t) * (newsize - dc->maxunit));
1357 		if (dc->devices)
1358 			free(dc->devices, M_BUS);
1359 		dc->devices = newlist;
1360 		dc->maxunit = newsize;
1361 	}
1362 	PDEBUG(("now: unit %d in devclass %s", unit, DEVCLANAME(dc)));
1363 
1364 	*unitp = unit;
1365 	return (0);
1366 }
1367 
1368 /**
1369  * @internal
1370  * @brief Add a device to a devclass
1371  *
1372  * A unit number is allocated for the device (using the device's
1373  * preferred unit number if any) and the device is registered in the
1374  * devclass. This allows the device to be looked up by its unit
1375  * number, e.g. by decoding a dev_t minor number.
1376  *
1377  * @param dc		the devclass to add to
1378  * @param dev		the device to add
1379  *
1380  * @retval 0		success
1381  * @retval EEXIST	the requested unit number is already allocated
1382  * @retval ENOMEM	memory allocation failure
1383  */
1384 static int
1385 devclass_add_device(devclass_t dc, device_t dev)
1386 {
1387 	int buflen, error;
1388 
1389 	PDEBUG(("%s in devclass %s", DEVICENAME(dev), DEVCLANAME(dc)));
1390 
1391 	buflen = snprintf(NULL, 0, "%s%d$", dc->name, dev->unit);
1392 	if (buflen < 0)
1393 		return (ENOMEM);
1394 	dev->nameunit = malloc(buflen, M_BUS, M_NOWAIT|M_ZERO);
1395 	if (!dev->nameunit)
1396 		return (ENOMEM);
1397 
1398 	if ((error = devclass_alloc_unit(dc, &dev->unit)) != 0) {
1399 		free(dev->nameunit, M_BUS);
1400 		dev->nameunit = NULL;
1401 		return (error);
1402 	}
1403 	dc->devices[dev->unit] = dev;
1404 	dev->devclass = dc;
1405 	snprintf(dev->nameunit, buflen, "%s%d", dc->name, dev->unit);
1406 
1407 	return (0);
1408 }
1409 
1410 /**
1411  * @internal
1412  * @brief Delete a device from a devclass
1413  *
1414  * The device is removed from the devclass's device list and its unit
1415  * number is freed.
1416 
1417  * @param dc		the devclass to delete from
1418  * @param dev		the device to delete
1419  *
1420  * @retval 0		success
1421  */
1422 static int
1423 devclass_delete_device(devclass_t dc, device_t dev)
1424 {
1425 	if (!dc || !dev)
1426 		return (0);
1427 
1428 	PDEBUG(("%s in devclass %s", DEVICENAME(dev), DEVCLANAME(dc)));
1429 
1430 	if (dev->devclass != dc || dc->devices[dev->unit] != dev)
1431 		panic("devclass_delete_device: inconsistent device class");
1432 	dc->devices[dev->unit] = NULL;
1433 	if (dev->flags & DF_WILDCARD)
1434 		dev->unit = -1;
1435 	dev->devclass = NULL;
1436 	free(dev->nameunit, M_BUS);
1437 	dev->nameunit = NULL;
1438 
1439 	return (0);
1440 }
1441 
1442 /**
1443  * @internal
1444  * @brief Make a new device and add it as a child of @p parent
1445  *
1446  * @param parent	the parent of the new device
1447  * @param name		the devclass name of the new device or @c NULL
1448  *			to leave the devclass unspecified
1449  * @parem unit		the unit number of the new device of @c -1 to
1450  *			leave the unit number unspecified
1451  *
1452  * @returns the new device
1453  */
1454 static device_t
1455 make_device(device_t parent, const char *name, int unit)
1456 {
1457 	device_t dev;
1458 	devclass_t dc;
1459 
1460 	PDEBUG(("%s at %s as unit %d", name, DEVICENAME(parent), unit));
1461 
1462 	if (name) {
1463 		dc = devclass_find_internal(name, NULL, TRUE);
1464 		if (!dc) {
1465 			printf("make_device: can't find device class %s\n",
1466 			    name);
1467 			return (NULL);
1468 		}
1469 	} else {
1470 		dc = NULL;
1471 	}
1472 
1473 	dev = malloc(sizeof(struct device), M_BUS, M_NOWAIT|M_ZERO);
1474 	if (!dev)
1475 		return (NULL);
1476 
1477 	dev->parent = parent;
1478 	TAILQ_INIT(&dev->children);
1479 	kobj_init((kobj_t) dev, &null_class);
1480 	dev->driver = NULL;
1481 	dev->devclass = NULL;
1482 	dev->unit = unit;
1483 	dev->nameunit = NULL;
1484 	dev->desc = NULL;
1485 	dev->busy = 0;
1486 	dev->devflags = 0;
1487 	dev->flags = DF_ENABLED;
1488 	dev->order = 0;
1489 	if (unit == -1)
1490 		dev->flags |= DF_WILDCARD;
1491 	if (name) {
1492 		dev->flags |= DF_FIXEDCLASS;
1493 		if (devclass_add_device(dc, dev)) {
1494 			kobj_delete((kobj_t) dev, M_BUS);
1495 			return (NULL);
1496 		}
1497 	}
1498 	dev->ivars = NULL;
1499 	dev->softc = NULL;
1500 
1501 	dev->state = DS_NOTPRESENT;
1502 
1503 	TAILQ_INSERT_TAIL(&bus_data_devices, dev, devlink);
1504 	bus_data_generation_update();
1505 
1506 	return (dev);
1507 }
1508 
1509 /**
1510  * @internal
1511  * @brief Print a description of a device.
1512  */
1513 static int
1514 device_print_child(device_t dev, device_t child)
1515 {
1516 	int retval = 0;
1517 
1518 	if (device_is_alive(child))
1519 		retval += BUS_PRINT_CHILD(dev, child);
1520 	else
1521 		retval += device_printf(child, " not found\n");
1522 
1523 	return (retval);
1524 }
1525 
1526 /**
1527  * @brief Create a new device
1528  *
1529  * This creates a new device and adds it as a child of an existing
1530  * parent device. The new device will be added after the last existing
1531  * child with order zero.
1532  *
1533  * @param dev		the device which will be the parent of the
1534  *			new child device
1535  * @param name		devclass name for new device or @c NULL if not
1536  *			specified
1537  * @param unit		unit number for new device or @c -1 if not
1538  *			specified
1539  *
1540  * @returns		the new device
1541  */
1542 device_t
1543 device_add_child(device_t dev, const char *name, int unit)
1544 {
1545 	return (device_add_child_ordered(dev, 0, name, unit));
1546 }
1547 
1548 /**
1549  * @brief Create a new device
1550  *
1551  * This creates a new device and adds it as a child of an existing
1552  * parent device. The new device will be added after the last existing
1553  * child with the same order.
1554  *
1555  * @param dev		the device which will be the parent of the
1556  *			new child device
1557  * @param order		a value which is used to partially sort the
1558  *			children of @p dev - devices created using
1559  *			lower values of @p order appear first in @p
1560  *			dev's list of children
1561  * @param name		devclass name for new device or @c NULL if not
1562  *			specified
1563  * @param unit		unit number for new device or @c -1 if not
1564  *			specified
1565  *
1566  * @returns		the new device
1567  */
1568 device_t
1569 device_add_child_ordered(device_t dev, int order, const char *name, int unit)
1570 {
1571 	device_t child;
1572 	device_t place;
1573 
1574 	PDEBUG(("%s at %s with order %d as unit %d",
1575 	    name, DEVICENAME(dev), order, unit));
1576 
1577 	child = make_device(dev, name, unit);
1578 	if (child == NULL)
1579 		return (child);
1580 	child->order = order;
1581 
1582 	TAILQ_FOREACH(place, &dev->children, link) {
1583 		if (place->order > order)
1584 			break;
1585 	}
1586 
1587 	if (place) {
1588 		/*
1589 		 * The device 'place' is the first device whose order is
1590 		 * greater than the new child.
1591 		 */
1592 		TAILQ_INSERT_BEFORE(place, child, link);
1593 	} else {
1594 		/*
1595 		 * The new child's order is greater or equal to the order of
1596 		 * any existing device. Add the child to the tail of the list.
1597 		 */
1598 		TAILQ_INSERT_TAIL(&dev->children, child, link);
1599 	}
1600 
1601 	bus_data_generation_update();
1602 	return (child);
1603 }
1604 
1605 /**
1606  * @brief Delete a device
1607  *
1608  * This function deletes a device along with all of its children. If
1609  * the device currently has a driver attached to it, the device is
1610  * detached first using device_detach().
1611  *
1612  * @param dev		the parent device
1613  * @param child		the device to delete
1614  *
1615  * @retval 0		success
1616  * @retval non-zero	a unit error code describing the error
1617  */
1618 int
1619 device_delete_child(device_t dev, device_t child)
1620 {
1621 	int error;
1622 	device_t grandchild;
1623 
1624 	PDEBUG(("%s from %s", DEVICENAME(child), DEVICENAME(dev)));
1625 
1626 	/* remove children first */
1627 	while ( (grandchild = TAILQ_FIRST(&child->children)) ) {
1628 		error = device_delete_child(child, grandchild);
1629 		if (error)
1630 			return (error);
1631 	}
1632 
1633 	if ((error = device_detach(child)) != 0)
1634 		return (error);
1635 	if (child->devclass)
1636 		devclass_delete_device(child->devclass, child);
1637 	TAILQ_REMOVE(&dev->children, child, link);
1638 	TAILQ_REMOVE(&bus_data_devices, child, devlink);
1639 	kobj_delete((kobj_t) child, M_BUS);
1640 
1641 	bus_data_generation_update();
1642 	return (0);
1643 }
1644 
1645 /**
1646  * @brief Find a device given a unit number
1647  *
1648  * This is similar to devclass_get_devices() but only searches for
1649  * devices which have @p dev as a parent.
1650  *
1651  * @param dev		the parent device to search
1652  * @param unit		the unit number to search for.  If the unit is -1,
1653  *			return the first child of @p dev which has name
1654  *			@p classname (that is, the one with the lowest unit.)
1655  *
1656  * @returns		the device with the given unit number or @c
1657  *			NULL if there is no such device
1658  */
1659 device_t
1660 device_find_child(device_t dev, const char *classname, int unit)
1661 {
1662 	devclass_t dc;
1663 	device_t child;
1664 
1665 	dc = devclass_find(classname);
1666 	if (!dc)
1667 		return (NULL);
1668 
1669 	if (unit != -1) {
1670 		child = devclass_get_device(dc, unit);
1671 		if (child && child->parent == dev)
1672 			return (child);
1673 	} else {
1674 		for (unit = 0; unit < devclass_get_maxunit(dc); unit++) {
1675 			child = devclass_get_device(dc, unit);
1676 			if (child && child->parent == dev)
1677 				return (child);
1678 		}
1679 	}
1680 	return (NULL);
1681 }
1682 
1683 /**
1684  * @internal
1685  */
1686 static driverlink_t
1687 first_matching_driver(devclass_t dc, device_t dev)
1688 {
1689 	if (dev->devclass)
1690 		return (devclass_find_driver_internal(dc, dev->devclass->name));
1691 	return (TAILQ_FIRST(&dc->drivers));
1692 }
1693 
1694 /**
1695  * @internal
1696  */
1697 static driverlink_t
1698 next_matching_driver(devclass_t dc, device_t dev, driverlink_t last)
1699 {
1700 	if (dev->devclass) {
1701 		driverlink_t dl;
1702 		for (dl = TAILQ_NEXT(last, link); dl; dl = TAILQ_NEXT(dl, link))
1703 			if (!strcmp(dev->devclass->name, dl->driver->name))
1704 				return (dl);
1705 		return (NULL);
1706 	}
1707 	return (TAILQ_NEXT(last, link));
1708 }
1709 
1710 /**
1711  * @internal
1712  */
1713 int
1714 device_probe_child(device_t dev, device_t child)
1715 {
1716 	devclass_t dc;
1717 	driverlink_t best = NULL;
1718 	driverlink_t dl;
1719 	int result, pri = 0;
1720 	int hasclass = (child->devclass != 0);
1721 
1722 	GIANT_REQUIRED;
1723 
1724 	dc = dev->devclass;
1725 	if (!dc)
1726 		panic("device_probe_child: parent device has no devclass");
1727 
1728 	/*
1729 	 * If the state is already probed, then return.  However, don't
1730 	 * return if we can rebid this object.
1731 	 */
1732 	if (child->state == DS_ALIVE && (child->flags & DF_REBID) == 0)
1733 		return (0);
1734 
1735 	for (; dc; dc = dc->parent) {
1736 		for (dl = first_matching_driver(dc, child);
1737 		     dl;
1738 		     dl = next_matching_driver(dc, child, dl)) {
1739 			PDEBUG(("Trying %s", DRIVERNAME(dl->driver)));
1740 			device_set_driver(child, dl->driver);
1741 			if (!hasclass)
1742 				device_set_devclass(child, dl->driver->name);
1743 
1744 			/* Fetch any flags for the device before probing. */
1745 			resource_int_value(dl->driver->name, child->unit,
1746 			    "flags", &child->devflags);
1747 
1748 			result = DEVICE_PROBE(child);
1749 
1750 			/* Reset flags and devclass before the next probe. */
1751 			child->devflags = 0;
1752 			if (!hasclass)
1753 				device_set_devclass(child, NULL);
1754 
1755 			/*
1756 			 * If the driver returns SUCCESS, there can be
1757 			 * no higher match for this device.
1758 			 */
1759 			if (result == 0) {
1760 				best = dl;
1761 				pri = 0;
1762 				break;
1763 			}
1764 
1765 			/*
1766 			 * The driver returned an error so it
1767 			 * certainly doesn't match.
1768 			 */
1769 			if (result > 0) {
1770 				device_set_driver(child, NULL);
1771 				continue;
1772 			}
1773 
1774 			/*
1775 			 * A priority lower than SUCCESS, remember the
1776 			 * best matching driver. Initialise the value
1777 			 * of pri for the first match.
1778 			 */
1779 			if (best == NULL || result > pri) {
1780 				/*
1781 				 * Probes that return BUS_PROBE_NOWILDCARD
1782 				 * or lower only match when they are set
1783 				 * in stone by the parent bus.
1784 				 */
1785 				if (result <= BUS_PROBE_NOWILDCARD &&
1786 				    child->flags & DF_WILDCARD)
1787 					continue;
1788 				best = dl;
1789 				pri = result;
1790 				continue;
1791 			}
1792 		}
1793 		/*
1794 		 * If we have an unambiguous match in this devclass,
1795 		 * don't look in the parent.
1796 		 */
1797 		if (best && pri == 0)
1798 			break;
1799 	}
1800 
1801 	/*
1802 	 * If we found a driver, change state and initialise the devclass.
1803 	 */
1804 	/* XXX What happens if we rebid and got no best? */
1805 	if (best) {
1806 		/*
1807 		 * If this device was atached, and we were asked to
1808 		 * rescan, and it is a different driver, then we have
1809 		 * to detach the old driver and reattach this new one.
1810 		 * Note, we don't have to check for DF_REBID here
1811 		 * because if the state is > DS_ALIVE, we know it must
1812 		 * be.
1813 		 *
1814 		 * This assumes that all DF_REBID drivers can have
1815 		 * their probe routine called at any time and that
1816 		 * they are idempotent as well as completely benign in
1817 		 * normal operations.
1818 		 *
1819 		 * We also have to make sure that the detach
1820 		 * succeeded, otherwise we fail the operation (or
1821 		 * maybe it should just fail silently?  I'm torn).
1822 		 */
1823 		if (child->state > DS_ALIVE && best->driver != child->driver)
1824 			if ((result = device_detach(dev)) != 0)
1825 				return (result);
1826 
1827 		/* Set the winning driver, devclass, and flags. */
1828 		if (!child->devclass)
1829 			device_set_devclass(child, best->driver->name);
1830 		device_set_driver(child, best->driver);
1831 		resource_int_value(best->driver->name, child->unit,
1832 		    "flags", &child->devflags);
1833 
1834 		if (pri < 0) {
1835 			/*
1836 			 * A bit bogus. Call the probe method again to make
1837 			 * sure that we have the right description.
1838 			 */
1839 			DEVICE_PROBE(child);
1840 #if 0
1841 			child->flags |= DF_REBID;
1842 #endif
1843 		} else
1844 			child->flags &= ~DF_REBID;
1845 		child->state = DS_ALIVE;
1846 
1847 		bus_data_generation_update();
1848 		return (0);
1849 	}
1850 
1851 	return (ENXIO);
1852 }
1853 
1854 /**
1855  * @brief Return the parent of a device
1856  */
1857 device_t
1858 device_get_parent(device_t dev)
1859 {
1860 	return (dev->parent);
1861 }
1862 
1863 /**
1864  * @brief Get a list of children of a device
1865  *
1866  * An array containing a list of all the children of the given device
1867  * is allocated and returned in @p *devlistp. The number of devices
1868  * in the array is returned in @p *devcountp. The caller should free
1869  * the array using @c free(p, M_TEMP).
1870  *
1871  * @param dev		the device to examine
1872  * @param devlistp	points at location for array pointer return
1873  *			value
1874  * @param devcountp	points at location for array size return value
1875  *
1876  * @retval 0		success
1877  * @retval ENOMEM	the array allocation failed
1878  */
1879 int
1880 device_get_children(device_t dev, device_t **devlistp, int *devcountp)
1881 {
1882 	int count;
1883 	device_t child;
1884 	device_t *list;
1885 
1886 	count = 0;
1887 	TAILQ_FOREACH(child, &dev->children, link) {
1888 		count++;
1889 	}
1890 
1891 	list = malloc(count * sizeof(device_t), M_TEMP, M_NOWAIT|M_ZERO);
1892 	if (!list)
1893 		return (ENOMEM);
1894 
1895 	count = 0;
1896 	TAILQ_FOREACH(child, &dev->children, link) {
1897 		list[count] = child;
1898 		count++;
1899 	}
1900 
1901 	*devlistp = list;
1902 	*devcountp = count;
1903 
1904 	return (0);
1905 }
1906 
1907 /**
1908  * @brief Return the current driver for the device or @c NULL if there
1909  * is no driver currently attached
1910  */
1911 driver_t *
1912 device_get_driver(device_t dev)
1913 {
1914 	return (dev->driver);
1915 }
1916 
1917 /**
1918  * @brief Return the current devclass for the device or @c NULL if
1919  * there is none.
1920  */
1921 devclass_t
1922 device_get_devclass(device_t dev)
1923 {
1924 	return (dev->devclass);
1925 }
1926 
1927 /**
1928  * @brief Return the name of the device's devclass or @c NULL if there
1929  * is none.
1930  */
1931 const char *
1932 device_get_name(device_t dev)
1933 {
1934 	if (dev != NULL && dev->devclass)
1935 		return (devclass_get_name(dev->devclass));
1936 	return (NULL);
1937 }
1938 
1939 /**
1940  * @brief Return a string containing the device's devclass name
1941  * followed by an ascii representation of the device's unit number
1942  * (e.g. @c "foo2").
1943  */
1944 const char *
1945 device_get_nameunit(device_t dev)
1946 {
1947 	return (dev->nameunit);
1948 }
1949 
1950 /**
1951  * @brief Return the device's unit number.
1952  */
1953 int
1954 device_get_unit(device_t dev)
1955 {
1956 	return (dev->unit);
1957 }
1958 
1959 /**
1960  * @brief Return the device's description string
1961  */
1962 const char *
1963 device_get_desc(device_t dev)
1964 {
1965 	return (dev->desc);
1966 }
1967 
1968 /**
1969  * @brief Return the device's flags
1970  */
1971 u_int32_t
1972 device_get_flags(device_t dev)
1973 {
1974 	return (dev->devflags);
1975 }
1976 
1977 struct sysctl_ctx_list *
1978 device_get_sysctl_ctx(device_t dev)
1979 {
1980 	return (&dev->sysctl_ctx);
1981 }
1982 
1983 struct sysctl_oid *
1984 device_get_sysctl_tree(device_t dev)
1985 {
1986 	return (dev->sysctl_tree);
1987 }
1988 
1989 /**
1990  * @brief Print the name of the device followed by a colon and a space
1991  *
1992  * @returns the number of characters printed
1993  */
1994 int
1995 device_print_prettyname(device_t dev)
1996 {
1997 	const char *name = device_get_name(dev);
1998 
1999 	if (name == 0)
2000 		return (printf("unknown: "));
2001 	return (printf("%s%d: ", name, device_get_unit(dev)));
2002 }
2003 
2004 /**
2005  * @brief Print the name of the device followed by a colon, a space
2006  * and the result of calling vprintf() with the value of @p fmt and
2007  * the following arguments.
2008  *
2009  * @returns the number of characters printed
2010  */
2011 int
2012 device_printf(device_t dev, const char * fmt, ...)
2013 {
2014 	va_list ap;
2015 	int retval;
2016 
2017 	retval = device_print_prettyname(dev);
2018 	va_start(ap, fmt);
2019 	retval += vprintf(fmt, ap);
2020 	va_end(ap);
2021 	return (retval);
2022 }
2023 
2024 /**
2025  * @internal
2026  */
2027 static void
2028 device_set_desc_internal(device_t dev, const char* desc, int copy)
2029 {
2030 	if (dev->desc && (dev->flags & DF_DESCMALLOCED)) {
2031 		free(dev->desc, M_BUS);
2032 		dev->flags &= ~DF_DESCMALLOCED;
2033 		dev->desc = NULL;
2034 	}
2035 
2036 	if (copy && desc) {
2037 		dev->desc = malloc(strlen(desc) + 1, M_BUS, M_NOWAIT);
2038 		if (dev->desc) {
2039 			strcpy(dev->desc, desc);
2040 			dev->flags |= DF_DESCMALLOCED;
2041 		}
2042 	} else {
2043 		/* Avoid a -Wcast-qual warning */
2044 		dev->desc = (char *)(uintptr_t) desc;
2045 	}
2046 
2047 	bus_data_generation_update();
2048 }
2049 
2050 /**
2051  * @brief Set the device's description
2052  *
2053  * The value of @c desc should be a string constant that will not
2054  * change (at least until the description is changed in a subsequent
2055  * call to device_set_desc() or device_set_desc_copy()).
2056  */
2057 void
2058 device_set_desc(device_t dev, const char* desc)
2059 {
2060 	device_set_desc_internal(dev, desc, FALSE);
2061 }
2062 
2063 /**
2064  * @brief Set the device's description
2065  *
2066  * The string pointed to by @c desc is copied. Use this function if
2067  * the device description is generated, (e.g. with sprintf()).
2068  */
2069 void
2070 device_set_desc_copy(device_t dev, const char* desc)
2071 {
2072 	device_set_desc_internal(dev, desc, TRUE);
2073 }
2074 
2075 /**
2076  * @brief Set the device's flags
2077  */
2078 void
2079 device_set_flags(device_t dev, u_int32_t flags)
2080 {
2081 	dev->devflags = flags;
2082 }
2083 
2084 /**
2085  * @brief Return the device's softc field
2086  *
2087  * The softc is allocated and zeroed when a driver is attached, based
2088  * on the size field of the driver.
2089  */
2090 void *
2091 device_get_softc(device_t dev)
2092 {
2093 	return (dev->softc);
2094 }
2095 
2096 /**
2097  * @brief Set the device's softc field
2098  *
2099  * Most drivers do not need to use this since the softc is allocated
2100  * automatically when the driver is attached.
2101  */
2102 void
2103 device_set_softc(device_t dev, void *softc)
2104 {
2105 	if (dev->softc && !(dev->flags & DF_EXTERNALSOFTC))
2106 		free(dev->softc, M_BUS_SC);
2107 	dev->softc = softc;
2108 	if (dev->softc)
2109 		dev->flags |= DF_EXTERNALSOFTC;
2110 	else
2111 		dev->flags &= ~DF_EXTERNALSOFTC;
2112 }
2113 
2114 /**
2115  * @brief Get the device's ivars field
2116  *
2117  * The ivars field is used by the parent device to store per-device
2118  * state (e.g. the physical location of the device or a list of
2119  * resources).
2120  */
2121 void *
2122 device_get_ivars(device_t dev)
2123 {
2124 
2125 	KASSERT(dev != NULL, ("device_get_ivars(NULL, ...)"));
2126 	return (dev->ivars);
2127 }
2128 
2129 /**
2130  * @brief Set the device's ivars field
2131  */
2132 void
2133 device_set_ivars(device_t dev, void * ivars)
2134 {
2135 
2136 	KASSERT(dev != NULL, ("device_set_ivars(NULL, ...)"));
2137 	dev->ivars = ivars;
2138 }
2139 
2140 /**
2141  * @brief Return the device's state
2142  */
2143 device_state_t
2144 device_get_state(device_t dev)
2145 {
2146 	return (dev->state);
2147 }
2148 
2149 /**
2150  * @brief Set the DF_ENABLED flag for the device
2151  */
2152 void
2153 device_enable(device_t dev)
2154 {
2155 	dev->flags |= DF_ENABLED;
2156 }
2157 
2158 /**
2159  * @brief Clear the DF_ENABLED flag for the device
2160  */
2161 void
2162 device_disable(device_t dev)
2163 {
2164 	dev->flags &= ~DF_ENABLED;
2165 }
2166 
2167 /**
2168  * @brief Increment the busy counter for the device
2169  */
2170 void
2171 device_busy(device_t dev)
2172 {
2173 	if (dev->state < DS_ATTACHED)
2174 		panic("device_busy: called for unattached device");
2175 	if (dev->busy == 0 && dev->parent)
2176 		device_busy(dev->parent);
2177 	dev->busy++;
2178 	dev->state = DS_BUSY;
2179 }
2180 
2181 /**
2182  * @brief Decrement the busy counter for the device
2183  */
2184 void
2185 device_unbusy(device_t dev)
2186 {
2187 	if (dev->state != DS_BUSY)
2188 		panic("device_unbusy: called for non-busy device %s",
2189 		    device_get_nameunit(dev));
2190 	dev->busy--;
2191 	if (dev->busy == 0) {
2192 		if (dev->parent)
2193 			device_unbusy(dev->parent);
2194 		dev->state = DS_ATTACHED;
2195 	}
2196 }
2197 
2198 /**
2199  * @brief Set the DF_QUIET flag for the device
2200  */
2201 void
2202 device_quiet(device_t dev)
2203 {
2204 	dev->flags |= DF_QUIET;
2205 }
2206 
2207 /**
2208  * @brief Clear the DF_QUIET flag for the device
2209  */
2210 void
2211 device_verbose(device_t dev)
2212 {
2213 	dev->flags &= ~DF_QUIET;
2214 }
2215 
2216 /**
2217  * @brief Return non-zero if the DF_QUIET flag is set on the device
2218  */
2219 int
2220 device_is_quiet(device_t dev)
2221 {
2222 	return ((dev->flags & DF_QUIET) != 0);
2223 }
2224 
2225 /**
2226  * @brief Return non-zero if the DF_ENABLED flag is set on the device
2227  */
2228 int
2229 device_is_enabled(device_t dev)
2230 {
2231 	return ((dev->flags & DF_ENABLED) != 0);
2232 }
2233 
2234 /**
2235  * @brief Return non-zero if the device was successfully probed
2236  */
2237 int
2238 device_is_alive(device_t dev)
2239 {
2240 	return (dev->state >= DS_ALIVE);
2241 }
2242 
2243 /**
2244  * @brief Return non-zero if the device currently has a driver
2245  * attached to it
2246  */
2247 int
2248 device_is_attached(device_t dev)
2249 {
2250 	return (dev->state >= DS_ATTACHED);
2251 }
2252 
2253 /**
2254  * @brief Set the devclass of a device
2255  * @see devclass_add_device().
2256  */
2257 int
2258 device_set_devclass(device_t dev, const char *classname)
2259 {
2260 	devclass_t dc;
2261 	int error;
2262 
2263 	if (!classname) {
2264 		if (dev->devclass)
2265 			devclass_delete_device(dev->devclass, dev);
2266 		return (0);
2267 	}
2268 
2269 	if (dev->devclass) {
2270 		printf("device_set_devclass: device class already set\n");
2271 		return (EINVAL);
2272 	}
2273 
2274 	dc = devclass_find_internal(classname, NULL, TRUE);
2275 	if (!dc)
2276 		return (ENOMEM);
2277 
2278 	error = devclass_add_device(dc, dev);
2279 
2280 	bus_data_generation_update();
2281 	return (error);
2282 }
2283 
2284 /**
2285  * @brief Set the driver of a device
2286  *
2287  * @retval 0		success
2288  * @retval EBUSY	the device already has a driver attached
2289  * @retval ENOMEM	a memory allocation failure occurred
2290  */
2291 int
2292 device_set_driver(device_t dev, driver_t *driver)
2293 {
2294 	if (dev->state >= DS_ATTACHED)
2295 		return (EBUSY);
2296 
2297 	if (dev->driver == driver)
2298 		return (0);
2299 
2300 	if (dev->softc && !(dev->flags & DF_EXTERNALSOFTC)) {
2301 		free(dev->softc, M_BUS_SC);
2302 		dev->softc = NULL;
2303 	}
2304 	kobj_delete((kobj_t) dev, NULL);
2305 	dev->driver = driver;
2306 	if (driver) {
2307 		kobj_init((kobj_t) dev, (kobj_class_t) driver);
2308 		if (!(dev->flags & DF_EXTERNALSOFTC) && driver->size > 0) {
2309 			dev->softc = malloc(driver->size, M_BUS_SC,
2310 			    M_NOWAIT | M_ZERO);
2311 			if (!dev->softc) {
2312 				kobj_delete((kobj_t) dev, NULL);
2313 				kobj_init((kobj_t) dev, &null_class);
2314 				dev->driver = NULL;
2315 				return (ENOMEM);
2316 			}
2317 		}
2318 	} else {
2319 		kobj_init((kobj_t) dev, &null_class);
2320 	}
2321 
2322 	bus_data_generation_update();
2323 	return (0);
2324 }
2325 
2326 /**
2327  * @brief Probe a device and attach a driver if possible
2328  *
2329  * This function is the core of the device autoconfiguration
2330  * system. Its purpose is to select a suitable driver for a device and
2331  * then call that driver to initialise the hardware appropriately. The
2332  * driver is selected by calling the DEVICE_PROBE() method of a set of
2333  * candidate drivers and then choosing the driver which returned the
2334  * best value. This driver is then attached to the device using
2335  * device_attach().
2336  *
2337  * The set of suitable drivers is taken from the list of drivers in
2338  * the parent device's devclass. If the device was originally created
2339  * with a specific class name (see device_add_child()), only drivers
2340  * with that name are probed, otherwise all drivers in the devclass
2341  * are probed. If no drivers return successful probe values in the
2342  * parent devclass, the search continues in the parent of that
2343  * devclass (see devclass_get_parent()) if any.
2344  *
2345  * @param dev		the device to initialise
2346  *
2347  * @retval 0		success
2348  * @retval ENXIO	no driver was found
2349  * @retval ENOMEM	memory allocation failure
2350  * @retval non-zero	some other unix error code
2351  */
2352 int
2353 device_probe_and_attach(device_t dev)
2354 {
2355 	int error;
2356 
2357 	GIANT_REQUIRED;
2358 
2359 	if (dev->state >= DS_ALIVE && (dev->flags & DF_REBID) == 0)
2360 		return (0);
2361 
2362 	if (!(dev->flags & DF_ENABLED)) {
2363 		if (bootverbose && device_get_name(dev) != NULL) {
2364 			device_print_prettyname(dev);
2365 			printf("not probed (disabled)\n");
2366 		}
2367 		return (0);
2368 	}
2369 	if ((error = device_probe_child(dev->parent, dev)) != 0) {
2370 		if (!(dev->flags & DF_DONENOMATCH)) {
2371 			BUS_PROBE_NOMATCH(dev->parent, dev);
2372 			devnomatch(dev);
2373 			dev->flags |= DF_DONENOMATCH;
2374 		}
2375 		return (error);
2376 	}
2377 	error = device_attach(dev);
2378 
2379 	return (error);
2380 }
2381 
2382 /**
2383  * @brief Attach a device driver to a device
2384  *
2385  * This function is a wrapper around the DEVICE_ATTACH() driver
2386  * method. In addition to calling DEVICE_ATTACH(), it initialises the
2387  * device's sysctl tree, optionally prints a description of the device
2388  * and queues a notification event for user-based device management
2389  * services.
2390  *
2391  * Normally this function is only called internally from
2392  * device_probe_and_attach().
2393  *
2394  * @param dev		the device to initialise
2395  *
2396  * @retval 0		success
2397  * @retval ENXIO	no driver was found
2398  * @retval ENOMEM	memory allocation failure
2399  * @retval non-zero	some other unix error code
2400  */
2401 int
2402 device_attach(device_t dev)
2403 {
2404 	int error;
2405 
2406 	device_sysctl_init(dev);
2407 	if (!device_is_quiet(dev))
2408 		device_print_child(dev->parent, dev);
2409 	if ((error = DEVICE_ATTACH(dev)) != 0) {
2410 		printf("device_attach: %s%d attach returned %d\n",
2411 		    dev->driver->name, dev->unit, error);
2412 		/* Unset the class; set in device_probe_child */
2413 		if (dev->devclass == NULL)
2414 			device_set_devclass(dev, NULL);
2415 		device_set_driver(dev, NULL);
2416 		device_sysctl_fini(dev);
2417 		dev->state = DS_NOTPRESENT;
2418 		return (error);
2419 	}
2420 	device_sysctl_update(dev);
2421 	dev->state = DS_ATTACHED;
2422 	devadded(dev);
2423 	return (0);
2424 }
2425 
2426 /**
2427  * @brief Detach a driver from a device
2428  *
2429  * This function is a wrapper around the DEVICE_DETACH() driver
2430  * method. If the call to DEVICE_DETACH() succeeds, it calls
2431  * BUS_CHILD_DETACHED() for the parent of @p dev, queues a
2432  * notification event for user-based device management services and
2433  * cleans up the device's sysctl tree.
2434  *
2435  * @param dev		the device to un-initialise
2436  *
2437  * @retval 0		success
2438  * @retval ENXIO	no driver was found
2439  * @retval ENOMEM	memory allocation failure
2440  * @retval non-zero	some other unix error code
2441  */
2442 int
2443 device_detach(device_t dev)
2444 {
2445 	int error;
2446 
2447 	GIANT_REQUIRED;
2448 
2449 	PDEBUG(("%s", DEVICENAME(dev)));
2450 	if (dev->state == DS_BUSY)
2451 		return (EBUSY);
2452 	if (dev->state != DS_ATTACHED)
2453 		return (0);
2454 
2455 	if ((error = DEVICE_DETACH(dev)) != 0)
2456 		return (error);
2457 	devremoved(dev);
2458 	device_printf(dev, "detached\n");
2459 	if (dev->parent)
2460 		BUS_CHILD_DETACHED(dev->parent, dev);
2461 
2462 	if (!(dev->flags & DF_FIXEDCLASS))
2463 		devclass_delete_device(dev->devclass, dev);
2464 
2465 	dev->state = DS_NOTPRESENT;
2466 	device_set_driver(dev, NULL);
2467 	device_set_desc(dev, NULL);
2468 	device_sysctl_fini(dev);
2469 
2470 	return (0);
2471 }
2472 
2473 /**
2474  * @brief Tells a driver to quiesce itself.
2475  *
2476  * This function is a wrapper around the DEVICE_QUIESCE() driver
2477  * method. If the call to DEVICE_QUIESCE() succeeds.
2478  *
2479  * @param dev		the device to quiesce
2480  *
2481  * @retval 0		success
2482  * @retval ENXIO	no driver was found
2483  * @retval ENOMEM	memory allocation failure
2484  * @retval non-zero	some other unix error code
2485  */
2486 int
2487 device_quiesce(device_t dev)
2488 {
2489 
2490 	PDEBUG(("%s", DEVICENAME(dev)));
2491 	if (dev->state == DS_BUSY)
2492 		return (EBUSY);
2493 	if (dev->state != DS_ATTACHED)
2494 		return (0);
2495 
2496 	return (DEVICE_QUIESCE(dev));
2497 }
2498 
2499 /**
2500  * @brief Notify a device of system shutdown
2501  *
2502  * This function calls the DEVICE_SHUTDOWN() driver method if the
2503  * device currently has an attached driver.
2504  *
2505  * @returns the value returned by DEVICE_SHUTDOWN()
2506  */
2507 int
2508 device_shutdown(device_t dev)
2509 {
2510 	if (dev->state < DS_ATTACHED)
2511 		return (0);
2512 	return (DEVICE_SHUTDOWN(dev));
2513 }
2514 
2515 /**
2516  * @brief Set the unit number of a device
2517  *
2518  * This function can be used to override the unit number used for a
2519  * device (e.g. to wire a device to a pre-configured unit number).
2520  */
2521 int
2522 device_set_unit(device_t dev, int unit)
2523 {
2524 	devclass_t dc;
2525 	int err;
2526 
2527 	dc = device_get_devclass(dev);
2528 	if (unit < dc->maxunit && dc->devices[unit])
2529 		return (EBUSY);
2530 	err = devclass_delete_device(dc, dev);
2531 	if (err)
2532 		return (err);
2533 	dev->unit = unit;
2534 	err = devclass_add_device(dc, dev);
2535 	if (err)
2536 		return (err);
2537 
2538 	bus_data_generation_update();
2539 	return (0);
2540 }
2541 
2542 /*======================================*/
2543 /*
2544  * Some useful method implementations to make life easier for bus drivers.
2545  */
2546 
2547 /**
2548  * @brief Initialise a resource list.
2549  *
2550  * @param rl		the resource list to initialise
2551  */
2552 void
2553 resource_list_init(struct resource_list *rl)
2554 {
2555 	STAILQ_INIT(rl);
2556 }
2557 
2558 /**
2559  * @brief Reclaim memory used by a resource list.
2560  *
2561  * This function frees the memory for all resource entries on the list
2562  * (if any).
2563  *
2564  * @param rl		the resource list to free
2565  */
2566 void
2567 resource_list_free(struct resource_list *rl)
2568 {
2569 	struct resource_list_entry *rle;
2570 
2571 	while ((rle = STAILQ_FIRST(rl)) != NULL) {
2572 		if (rle->res)
2573 			panic("resource_list_free: resource entry is busy");
2574 		STAILQ_REMOVE_HEAD(rl, link);
2575 		free(rle, M_BUS);
2576 	}
2577 }
2578 
2579 /**
2580  * @brief Add a resource entry.
2581  *
2582  * This function adds a resource entry using the given @p type, @p
2583  * start, @p end and @p count values. A rid value is chosen by
2584  * searching sequentially for the first unused rid starting at zero.
2585  *
2586  * @param rl		the resource list to edit
2587  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
2588  * @param start		the start address of the resource
2589  * @param end		the end address of the resource
2590  * @param count		XXX end-start+1
2591  */
2592 int
2593 resource_list_add_next(struct resource_list *rl, int type, u_long start,
2594     u_long end, u_long count)
2595 {
2596 	int rid;
2597 
2598 	rid = 0;
2599 	while (resource_list_find(rl, type, rid) != NULL)
2600 		rid++;
2601 	resource_list_add(rl, type, rid, start, end, count);
2602 	return (rid);
2603 }
2604 
2605 /**
2606  * @brief Add or modify a resource entry.
2607  *
2608  * If an existing entry exists with the same type and rid, it will be
2609  * modified using the given values of @p start, @p end and @p
2610  * count. If no entry exists, a new one will be created using the
2611  * given values.  The resource list entry that matches is then returned.
2612  *
2613  * @param rl		the resource list to edit
2614  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
2615  * @param rid		the resource identifier
2616  * @param start		the start address of the resource
2617  * @param end		the end address of the resource
2618  * @param count		XXX end-start+1
2619  */
2620 struct resource_list_entry *
2621 resource_list_add(struct resource_list *rl, int type, int rid,
2622     u_long start, u_long end, u_long count)
2623 {
2624 	struct resource_list_entry *rle;
2625 
2626 	rle = resource_list_find(rl, type, rid);
2627 	if (!rle) {
2628 		rle = malloc(sizeof(struct resource_list_entry), M_BUS,
2629 		    M_NOWAIT);
2630 		if (!rle)
2631 			panic("resource_list_add: can't record entry");
2632 		STAILQ_INSERT_TAIL(rl, rle, link);
2633 		rle->type = type;
2634 		rle->rid = rid;
2635 		rle->res = NULL;
2636 	}
2637 
2638 	if (rle->res)
2639 		panic("resource_list_add: resource entry is busy");
2640 
2641 	rle->start = start;
2642 	rle->end = end;
2643 	rle->count = count;
2644 	return (rle);
2645 }
2646 
2647 /**
2648  * @brief Find a resource entry by type and rid.
2649  *
2650  * @param rl		the resource list to search
2651  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
2652  * @param rid		the resource identifier
2653  *
2654  * @returns the resource entry pointer or NULL if there is no such
2655  * entry.
2656  */
2657 struct resource_list_entry *
2658 resource_list_find(struct resource_list *rl, int type, int rid)
2659 {
2660 	struct resource_list_entry *rle;
2661 
2662 	STAILQ_FOREACH(rle, rl, link) {
2663 		if (rle->type == type && rle->rid == rid)
2664 			return (rle);
2665 	}
2666 	return (NULL);
2667 }
2668 
2669 /**
2670  * @brief Delete a resource entry.
2671  *
2672  * @param rl		the resource list to edit
2673  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
2674  * @param rid		the resource identifier
2675  */
2676 void
2677 resource_list_delete(struct resource_list *rl, int type, int rid)
2678 {
2679 	struct resource_list_entry *rle = resource_list_find(rl, type, rid);
2680 
2681 	if (rle) {
2682 		if (rle->res != NULL)
2683 			panic("resource_list_delete: resource has not been released");
2684 		STAILQ_REMOVE(rl, rle, resource_list_entry, link);
2685 		free(rle, M_BUS);
2686 	}
2687 }
2688 
2689 /**
2690  * @brief Helper function for implementing BUS_ALLOC_RESOURCE()
2691  *
2692  * Implement BUS_ALLOC_RESOURCE() by looking up a resource from the list
2693  * and passing the allocation up to the parent of @p bus. This assumes
2694  * that the first entry of @c device_get_ivars(child) is a struct
2695  * resource_list. This also handles 'passthrough' allocations where a
2696  * child is a remote descendant of bus by passing the allocation up to
2697  * the parent of bus.
2698  *
2699  * Typically, a bus driver would store a list of child resources
2700  * somewhere in the child device's ivars (see device_get_ivars()) and
2701  * its implementation of BUS_ALLOC_RESOURCE() would find that list and
2702  * then call resource_list_alloc() to perform the allocation.
2703  *
2704  * @param rl		the resource list to allocate from
2705  * @param bus		the parent device of @p child
2706  * @param child		the device which is requesting an allocation
2707  * @param type		the type of resource to allocate
2708  * @param rid		a pointer to the resource identifier
2709  * @param start		hint at the start of the resource range - pass
2710  *			@c 0UL for any start address
2711  * @param end		hint at the end of the resource range - pass
2712  *			@c ~0UL for any end address
2713  * @param count		hint at the size of range required - pass @c 1
2714  *			for any size
2715  * @param flags		any extra flags to control the resource
2716  *			allocation - see @c RF_XXX flags in
2717  *			<sys/rman.h> for details
2718  *
2719  * @returns		the resource which was allocated or @c NULL if no
2720  *			resource could be allocated
2721  */
2722 struct resource *
2723 resource_list_alloc(struct resource_list *rl, device_t bus, device_t child,
2724     int type, int *rid, u_long start, u_long end, u_long count, u_int flags)
2725 {
2726 	struct resource_list_entry *rle = NULL;
2727 	int passthrough = (device_get_parent(child) != bus);
2728 	int isdefault = (start == 0UL && end == ~0UL);
2729 
2730 	if (passthrough) {
2731 		return (BUS_ALLOC_RESOURCE(device_get_parent(bus), child,
2732 		    type, rid, start, end, count, flags));
2733 	}
2734 
2735 	rle = resource_list_find(rl, type, *rid);
2736 
2737 	if (!rle)
2738 		return (NULL);		/* no resource of that type/rid */
2739 
2740 	if (rle->res)
2741 		panic("resource_list_alloc: resource entry is busy");
2742 
2743 	if (isdefault) {
2744 		start = rle->start;
2745 		count = ulmax(count, rle->count);
2746 		end = ulmax(rle->end, start + count - 1);
2747 	}
2748 
2749 	rle->res = BUS_ALLOC_RESOURCE(device_get_parent(bus), child,
2750 	    type, rid, start, end, count, flags);
2751 
2752 	/*
2753 	 * Record the new range.
2754 	 */
2755 	if (rle->res) {
2756 		rle->start = rman_get_start(rle->res);
2757 		rle->end = rman_get_end(rle->res);
2758 		rle->count = count;
2759 	}
2760 
2761 	return (rle->res);
2762 }
2763 
2764 /**
2765  * @brief Helper function for implementing BUS_RELEASE_RESOURCE()
2766  *
2767  * Implement BUS_RELEASE_RESOURCE() using a resource list. Normally
2768  * used with resource_list_alloc().
2769  *
2770  * @param rl		the resource list which was allocated from
2771  * @param bus		the parent device of @p child
2772  * @param child		the device which is requesting a release
2773  * @param type		the type of resource to allocate
2774  * @param rid		the resource identifier
2775  * @param res		the resource to release
2776  *
2777  * @retval 0		success
2778  * @retval non-zero	a standard unix error code indicating what
2779  *			error condition prevented the operation
2780  */
2781 int
2782 resource_list_release(struct resource_list *rl, device_t bus, device_t child,
2783     int type, int rid, struct resource *res)
2784 {
2785 	struct resource_list_entry *rle = NULL;
2786 	int passthrough = (device_get_parent(child) != bus);
2787 	int error;
2788 
2789 	if (passthrough) {
2790 		return (BUS_RELEASE_RESOURCE(device_get_parent(bus), child,
2791 		    type, rid, res));
2792 	}
2793 
2794 	rle = resource_list_find(rl, type, rid);
2795 
2796 	if (!rle)
2797 		panic("resource_list_release: can't find resource");
2798 	if (!rle->res)
2799 		panic("resource_list_release: resource entry is not busy");
2800 
2801 	error = BUS_RELEASE_RESOURCE(device_get_parent(bus), child,
2802 	    type, rid, res);
2803 	if (error)
2804 		return (error);
2805 
2806 	rle->res = NULL;
2807 	return (0);
2808 }
2809 
2810 /**
2811  * @brief Print a description of resources in a resource list
2812  *
2813  * Print all resources of a specified type, for use in BUS_PRINT_CHILD().
2814  * The name is printed if at least one resource of the given type is available.
2815  * The format is used to print resource start and end.
2816  *
2817  * @param rl		the resource list to print
2818  * @param name		the name of @p type, e.g. @c "memory"
2819  * @param type		type type of resource entry to print
2820  * @param format	printf(9) format string to print resource
2821  *			start and end values
2822  *
2823  * @returns		the number of characters printed
2824  */
2825 int
2826 resource_list_print_type(struct resource_list *rl, const char *name, int type,
2827     const char *format)
2828 {
2829 	struct resource_list_entry *rle;
2830 	int printed, retval;
2831 
2832 	printed = 0;
2833 	retval = 0;
2834 	/* Yes, this is kinda cheating */
2835 	STAILQ_FOREACH(rle, rl, link) {
2836 		if (rle->type == type) {
2837 			if (printed == 0)
2838 				retval += printf(" %s ", name);
2839 			else
2840 				retval += printf(",");
2841 			printed++;
2842 			retval += printf(format, rle->start);
2843 			if (rle->count > 1) {
2844 				retval += printf("-");
2845 				retval += printf(format, rle->start +
2846 						 rle->count - 1);
2847 			}
2848 		}
2849 	}
2850 	return (retval);
2851 }
2852 
2853 /**
2854  * @brief Releases all the resources in a list.
2855  *
2856  * @param rl		The resource list to purge.
2857  *
2858  * @returns		nothing
2859  */
2860 void
2861 resource_list_purge(struct resource_list *rl)
2862 {
2863 	struct resource_list_entry *rle;
2864 
2865 	while ((rle = STAILQ_FIRST(rl)) != NULL) {
2866 		if (rle->res)
2867 			bus_release_resource(rman_get_device(rle->res),
2868 			    rle->type, rle->rid, rle->res);
2869 		STAILQ_REMOVE_HEAD(rl, link);
2870 		free(rle, M_BUS);
2871 	}
2872 }
2873 
2874 device_t
2875 bus_generic_add_child(device_t dev, int order, const char *name, int unit)
2876 {
2877 
2878 	return (device_add_child_ordered(dev, order, name, unit));
2879 }
2880 
2881 /**
2882  * @brief Helper function for implementing DEVICE_PROBE()
2883  *
2884  * This function can be used to help implement the DEVICE_PROBE() for
2885  * a bus (i.e. a device which has other devices attached to it). It
2886  * calls the DEVICE_IDENTIFY() method of each driver in the device's
2887  * devclass.
2888  */
2889 int
2890 bus_generic_probe(device_t dev)
2891 {
2892 	devclass_t dc = dev->devclass;
2893 	driverlink_t dl;
2894 
2895 	TAILQ_FOREACH(dl, &dc->drivers, link) {
2896 		DEVICE_IDENTIFY(dl->driver, dev);
2897 	}
2898 
2899 	return (0);
2900 }
2901 
2902 /**
2903  * @brief Helper function for implementing DEVICE_ATTACH()
2904  *
2905  * This function can be used to help implement the DEVICE_ATTACH() for
2906  * a bus. It calls device_probe_and_attach() for each of the device's
2907  * children.
2908  */
2909 int
2910 bus_generic_attach(device_t dev)
2911 {
2912 	device_t child;
2913 
2914 	TAILQ_FOREACH(child, &dev->children, link) {
2915 		device_probe_and_attach(child);
2916 	}
2917 
2918 	return (0);
2919 }
2920 
2921 /**
2922  * @brief Helper function for implementing DEVICE_DETACH()
2923  *
2924  * This function can be used to help implement the DEVICE_DETACH() for
2925  * a bus. It calls device_detach() for each of the device's
2926  * children.
2927  */
2928 int
2929 bus_generic_detach(device_t dev)
2930 {
2931 	device_t child;
2932 	int error;
2933 
2934 	if (dev->state != DS_ATTACHED)
2935 		return (EBUSY);
2936 
2937 	TAILQ_FOREACH(child, &dev->children, link) {
2938 		if ((error = device_detach(child)) != 0)
2939 			return (error);
2940 	}
2941 
2942 	return (0);
2943 }
2944 
2945 /**
2946  * @brief Helper function for implementing DEVICE_SHUTDOWN()
2947  *
2948  * This function can be used to help implement the DEVICE_SHUTDOWN()
2949  * for a bus. It calls device_shutdown() for each of the device's
2950  * children.
2951  */
2952 int
2953 bus_generic_shutdown(device_t dev)
2954 {
2955 	device_t child;
2956 
2957 	TAILQ_FOREACH(child, &dev->children, link) {
2958 		device_shutdown(child);
2959 	}
2960 
2961 	return (0);
2962 }
2963 
2964 /**
2965  * @brief Helper function for implementing DEVICE_SUSPEND()
2966  *
2967  * This function can be used to help implement the DEVICE_SUSPEND()
2968  * for a bus. It calls DEVICE_SUSPEND() for each of the device's
2969  * children. If any call to DEVICE_SUSPEND() fails, the suspend
2970  * operation is aborted and any devices which were suspended are
2971  * resumed immediately by calling their DEVICE_RESUME() methods.
2972  */
2973 int
2974 bus_generic_suspend(device_t dev)
2975 {
2976 	int		error;
2977 	device_t	child, child2;
2978 
2979 	TAILQ_FOREACH(child, &dev->children, link) {
2980 		error = DEVICE_SUSPEND(child);
2981 		if (error) {
2982 			for (child2 = TAILQ_FIRST(&dev->children);
2983 			     child2 && child2 != child;
2984 			     child2 = TAILQ_NEXT(child2, link))
2985 				DEVICE_RESUME(child2);
2986 			return (error);
2987 		}
2988 	}
2989 	return (0);
2990 }
2991 
2992 /**
2993  * @brief Helper function for implementing DEVICE_RESUME()
2994  *
2995  * This function can be used to help implement the DEVICE_RESUME() for
2996  * a bus. It calls DEVICE_RESUME() on each of the device's children.
2997  */
2998 int
2999 bus_generic_resume(device_t dev)
3000 {
3001 	device_t	child;
3002 
3003 	TAILQ_FOREACH(child, &dev->children, link) {
3004 		DEVICE_RESUME(child);
3005 		/* if resume fails, there's nothing we can usefully do... */
3006 	}
3007 	return (0);
3008 }
3009 
3010 /**
3011  * @brief Helper function for implementing BUS_PRINT_CHILD().
3012  *
3013  * This function prints the first part of the ascii representation of
3014  * @p child, including its name, unit and description (if any - see
3015  * device_set_desc()).
3016  *
3017  * @returns the number of characters printed
3018  */
3019 int
3020 bus_print_child_header(device_t dev, device_t child)
3021 {
3022 	int	retval = 0;
3023 
3024 	if (device_get_desc(child)) {
3025 		retval += device_printf(child, "<%s>", device_get_desc(child));
3026 	} else {
3027 		retval += printf("%s", device_get_nameunit(child));
3028 	}
3029 
3030 	return (retval);
3031 }
3032 
3033 /**
3034  * @brief Helper function for implementing BUS_PRINT_CHILD().
3035  *
3036  * This function prints the last part of the ascii representation of
3037  * @p child, which consists of the string @c " on " followed by the
3038  * name and unit of the @p dev.
3039  *
3040  * @returns the number of characters printed
3041  */
3042 int
3043 bus_print_child_footer(device_t dev, device_t child)
3044 {
3045 	return (printf(" on %s\n", device_get_nameunit(dev)));
3046 }
3047 
3048 /**
3049  * @brief Helper function for implementing BUS_PRINT_CHILD().
3050  *
3051  * This function simply calls bus_print_child_header() followed by
3052  * bus_print_child_footer().
3053  *
3054  * @returns the number of characters printed
3055  */
3056 int
3057 bus_generic_print_child(device_t dev, device_t child)
3058 {
3059 	int	retval = 0;
3060 
3061 	retval += bus_print_child_header(dev, child);
3062 	retval += bus_print_child_footer(dev, child);
3063 
3064 	return (retval);
3065 }
3066 
3067 /**
3068  * @brief Stub function for implementing BUS_READ_IVAR().
3069  *
3070  * @returns ENOENT
3071  */
3072 int
3073 bus_generic_read_ivar(device_t dev, device_t child, int index,
3074     uintptr_t * result)
3075 {
3076 	return (ENOENT);
3077 }
3078 
3079 /**
3080  * @brief Stub function for implementing BUS_WRITE_IVAR().
3081  *
3082  * @returns ENOENT
3083  */
3084 int
3085 bus_generic_write_ivar(device_t dev, device_t child, int index,
3086     uintptr_t value)
3087 {
3088 	return (ENOENT);
3089 }
3090 
3091 /**
3092  * @brief Stub function for implementing BUS_GET_RESOURCE_LIST().
3093  *
3094  * @returns NULL
3095  */
3096 struct resource_list *
3097 bus_generic_get_resource_list(device_t dev, device_t child)
3098 {
3099 	return (NULL);
3100 }
3101 
3102 /**
3103  * @brief Helper function for implementing BUS_DRIVER_ADDED().
3104  *
3105  * This implementation of BUS_DRIVER_ADDED() simply calls the driver's
3106  * DEVICE_IDENTIFY() method to allow it to add new children to the bus
3107  * and then calls device_probe_and_attach() for each unattached child.
3108  */
3109 void
3110 bus_generic_driver_added(device_t dev, driver_t *driver)
3111 {
3112 	device_t child;
3113 
3114 	DEVICE_IDENTIFY(driver, dev);
3115 	TAILQ_FOREACH(child, &dev->children, link) {
3116 		if (child->state == DS_NOTPRESENT ||
3117 		    (child->flags & DF_REBID))
3118 			device_probe_and_attach(child);
3119 	}
3120 }
3121 
3122 /**
3123  * @brief Helper function for implementing BUS_SETUP_INTR().
3124  *
3125  * This simple implementation of BUS_SETUP_INTR() simply calls the
3126  * BUS_SETUP_INTR() method of the parent of @p dev.
3127  */
3128 int
3129 bus_generic_setup_intr(device_t dev, device_t child, struct resource *irq,
3130     int flags, driver_filter_t *filter, driver_intr_t *intr, void *arg,
3131     void **cookiep)
3132 {
3133 	/* Propagate up the bus hierarchy until someone handles it. */
3134 	if (dev->parent)
3135 		return (BUS_SETUP_INTR(dev->parent, child, irq, flags,
3136 		    filter, intr, arg, cookiep));
3137 	return (EINVAL);
3138 }
3139 
3140 /**
3141  * @brief Helper function for implementing BUS_TEARDOWN_INTR().
3142  *
3143  * This simple implementation of BUS_TEARDOWN_INTR() simply calls the
3144  * BUS_TEARDOWN_INTR() method of the parent of @p dev.
3145  */
3146 int
3147 bus_generic_teardown_intr(device_t dev, device_t child, struct resource *irq,
3148     void *cookie)
3149 {
3150 	/* Propagate up the bus hierarchy until someone handles it. */
3151 	if (dev->parent)
3152 		return (BUS_TEARDOWN_INTR(dev->parent, child, irq, cookie));
3153 	return (EINVAL);
3154 }
3155 
3156 /**
3157  * @brief Helper function for implementing BUS_ALLOC_RESOURCE().
3158  *
3159  * This simple implementation of BUS_ALLOC_RESOURCE() simply calls the
3160  * BUS_ALLOC_RESOURCE() method of the parent of @p dev.
3161  */
3162 struct resource *
3163 bus_generic_alloc_resource(device_t dev, device_t child, int type, int *rid,
3164     u_long start, u_long end, u_long count, u_int flags)
3165 {
3166 	/* Propagate up the bus hierarchy until someone handles it. */
3167 	if (dev->parent)
3168 		return (BUS_ALLOC_RESOURCE(dev->parent, child, type, rid,
3169 		    start, end, count, flags));
3170 	return (NULL);
3171 }
3172 
3173 /**
3174  * @brief Helper function for implementing BUS_RELEASE_RESOURCE().
3175  *
3176  * This simple implementation of BUS_RELEASE_RESOURCE() simply calls the
3177  * BUS_RELEASE_RESOURCE() method of the parent of @p dev.
3178  */
3179 int
3180 bus_generic_release_resource(device_t dev, device_t child, int type, int rid,
3181     struct resource *r)
3182 {
3183 	/* Propagate up the bus hierarchy until someone handles it. */
3184 	if (dev->parent)
3185 		return (BUS_RELEASE_RESOURCE(dev->parent, child, type, rid,
3186 		    r));
3187 	return (EINVAL);
3188 }
3189 
3190 /**
3191  * @brief Helper function for implementing BUS_ACTIVATE_RESOURCE().
3192  *
3193  * This simple implementation of BUS_ACTIVATE_RESOURCE() simply calls the
3194  * BUS_ACTIVATE_RESOURCE() method of the parent of @p dev.
3195  */
3196 int
3197 bus_generic_activate_resource(device_t dev, device_t child, int type, int rid,
3198     struct resource *r)
3199 {
3200 	/* Propagate up the bus hierarchy until someone handles it. */
3201 	if (dev->parent)
3202 		return (BUS_ACTIVATE_RESOURCE(dev->parent, child, type, rid,
3203 		    r));
3204 	return (EINVAL);
3205 }
3206 
3207 /**
3208  * @brief Helper function for implementing BUS_DEACTIVATE_RESOURCE().
3209  *
3210  * This simple implementation of BUS_DEACTIVATE_RESOURCE() simply calls the
3211  * BUS_DEACTIVATE_RESOURCE() method of the parent of @p dev.
3212  */
3213 int
3214 bus_generic_deactivate_resource(device_t dev, device_t child, int type,
3215     int rid, struct resource *r)
3216 {
3217 	/* Propagate up the bus hierarchy until someone handles it. */
3218 	if (dev->parent)
3219 		return (BUS_DEACTIVATE_RESOURCE(dev->parent, child, type, rid,
3220 		    r));
3221 	return (EINVAL);
3222 }
3223 
3224 /**
3225  * @brief Helper function for implementing BUS_BIND_INTR().
3226  *
3227  * This simple implementation of BUS_BIND_INTR() simply calls the
3228  * BUS_BIND_INTR() method of the parent of @p dev.
3229  */
3230 int
3231 bus_generic_bind_intr(device_t dev, device_t child, struct resource *irq,
3232     int cpu)
3233 {
3234 
3235 	/* Propagate up the bus hierarchy until someone handles it. */
3236 	if (dev->parent)
3237 		return (BUS_BIND_INTR(dev->parent, child, irq, cpu));
3238 	return (EINVAL);
3239 }
3240 
3241 /**
3242  * @brief Helper function for implementing BUS_CONFIG_INTR().
3243  *
3244  * This simple implementation of BUS_CONFIG_INTR() simply calls the
3245  * BUS_CONFIG_INTR() method of the parent of @p dev.
3246  */
3247 int
3248 bus_generic_config_intr(device_t dev, int irq, enum intr_trigger trig,
3249     enum intr_polarity pol)
3250 {
3251 
3252 	/* Propagate up the bus hierarchy until someone handles it. */
3253 	if (dev->parent)
3254 		return (BUS_CONFIG_INTR(dev->parent, irq, trig, pol));
3255 	return (EINVAL);
3256 }
3257 
3258 /**
3259  * @brief Helper function for implementing BUS_GET_DMA_TAG().
3260  *
3261  * This simple implementation of BUS_GET_DMA_TAG() simply calls the
3262  * BUS_GET_DMA_TAG() method of the parent of @p dev.
3263  */
3264 bus_dma_tag_t
3265 bus_generic_get_dma_tag(device_t dev, device_t child)
3266 {
3267 
3268 	/* Propagate up the bus hierarchy until someone handles it. */
3269 	if (dev->parent != NULL)
3270 		return (BUS_GET_DMA_TAG(dev->parent, child));
3271 	return (NULL);
3272 }
3273 
3274 /**
3275  * @brief Helper function for implementing BUS_GET_RESOURCE().
3276  *
3277  * This implementation of BUS_GET_RESOURCE() uses the
3278  * resource_list_find() function to do most of the work. It calls
3279  * BUS_GET_RESOURCE_LIST() to find a suitable resource list to
3280  * search.
3281  */
3282 int
3283 bus_generic_rl_get_resource(device_t dev, device_t child, int type, int rid,
3284     u_long *startp, u_long *countp)
3285 {
3286 	struct resource_list *		rl = NULL;
3287 	struct resource_list_entry *	rle = NULL;
3288 
3289 	rl = BUS_GET_RESOURCE_LIST(dev, child);
3290 	if (!rl)
3291 		return (EINVAL);
3292 
3293 	rle = resource_list_find(rl, type, rid);
3294 	if (!rle)
3295 		return (ENOENT);
3296 
3297 	if (startp)
3298 		*startp = rle->start;
3299 	if (countp)
3300 		*countp = rle->count;
3301 
3302 	return (0);
3303 }
3304 
3305 /**
3306  * @brief Helper function for implementing BUS_SET_RESOURCE().
3307  *
3308  * This implementation of BUS_SET_RESOURCE() uses the
3309  * resource_list_add() function to do most of the work. It calls
3310  * BUS_GET_RESOURCE_LIST() to find a suitable resource list to
3311  * edit.
3312  */
3313 int
3314 bus_generic_rl_set_resource(device_t dev, device_t child, int type, int rid,
3315     u_long start, u_long count)
3316 {
3317 	struct resource_list *		rl = NULL;
3318 
3319 	rl = BUS_GET_RESOURCE_LIST(dev, child);
3320 	if (!rl)
3321 		return (EINVAL);
3322 
3323 	resource_list_add(rl, type, rid, start, (start + count - 1), count);
3324 
3325 	return (0);
3326 }
3327 
3328 /**
3329  * @brief Helper function for implementing BUS_DELETE_RESOURCE().
3330  *
3331  * This implementation of BUS_DELETE_RESOURCE() uses the
3332  * resource_list_delete() function to do most of the work. It calls
3333  * BUS_GET_RESOURCE_LIST() to find a suitable resource list to
3334  * edit.
3335  */
3336 void
3337 bus_generic_rl_delete_resource(device_t dev, device_t child, int type, int rid)
3338 {
3339 	struct resource_list *		rl = NULL;
3340 
3341 	rl = BUS_GET_RESOURCE_LIST(dev, child);
3342 	if (!rl)
3343 		return;
3344 
3345 	resource_list_delete(rl, type, rid);
3346 
3347 	return;
3348 }
3349 
3350 /**
3351  * @brief Helper function for implementing BUS_RELEASE_RESOURCE().
3352  *
3353  * This implementation of BUS_RELEASE_RESOURCE() uses the
3354  * resource_list_release() function to do most of the work. It calls
3355  * BUS_GET_RESOURCE_LIST() to find a suitable resource list.
3356  */
3357 int
3358 bus_generic_rl_release_resource(device_t dev, device_t child, int type,
3359     int rid, struct resource *r)
3360 {
3361 	struct resource_list *		rl = NULL;
3362 
3363 	rl = BUS_GET_RESOURCE_LIST(dev, child);
3364 	if (!rl)
3365 		return (EINVAL);
3366 
3367 	return (resource_list_release(rl, dev, child, type, rid, r));
3368 }
3369 
3370 /**
3371  * @brief Helper function for implementing BUS_ALLOC_RESOURCE().
3372  *
3373  * This implementation of BUS_ALLOC_RESOURCE() uses the
3374  * resource_list_alloc() function to do most of the work. It calls
3375  * BUS_GET_RESOURCE_LIST() to find a suitable resource list.
3376  */
3377 struct resource *
3378 bus_generic_rl_alloc_resource(device_t dev, device_t child, int type,
3379     int *rid, u_long start, u_long end, u_long count, u_int flags)
3380 {
3381 	struct resource_list *		rl = NULL;
3382 
3383 	rl = BUS_GET_RESOURCE_LIST(dev, child);
3384 	if (!rl)
3385 		return (NULL);
3386 
3387 	return (resource_list_alloc(rl, dev, child, type, rid,
3388 	    start, end, count, flags));
3389 }
3390 
3391 /**
3392  * @brief Helper function for implementing BUS_CHILD_PRESENT().
3393  *
3394  * This simple implementation of BUS_CHILD_PRESENT() simply calls the
3395  * BUS_CHILD_PRESENT() method of the parent of @p dev.
3396  */
3397 int
3398 bus_generic_child_present(device_t dev, device_t child)
3399 {
3400 	return (BUS_CHILD_PRESENT(device_get_parent(dev), dev));
3401 }
3402 
3403 /*
3404  * Some convenience functions to make it easier for drivers to use the
3405  * resource-management functions.  All these really do is hide the
3406  * indirection through the parent's method table, making for slightly
3407  * less-wordy code.  In the future, it might make sense for this code
3408  * to maintain some sort of a list of resources allocated by each device.
3409  */
3410 
3411 int
3412 bus_alloc_resources(device_t dev, struct resource_spec *rs,
3413     struct resource **res)
3414 {
3415 	int i;
3416 
3417 	for (i = 0; rs[i].type != -1; i++)
3418 		res[i] = NULL;
3419 	for (i = 0; rs[i].type != -1; i++) {
3420 		res[i] = bus_alloc_resource_any(dev,
3421 		    rs[i].type, &rs[i].rid, rs[i].flags);
3422 		if (res[i] == NULL && !(rs[i].flags & RF_OPTIONAL)) {
3423 			bus_release_resources(dev, rs, res);
3424 			return (ENXIO);
3425 		}
3426 	}
3427 	return (0);
3428 }
3429 
3430 void
3431 bus_release_resources(device_t dev, const struct resource_spec *rs,
3432     struct resource **res)
3433 {
3434 	int i;
3435 
3436 	for (i = 0; rs[i].type != -1; i++)
3437 		if (res[i] != NULL) {
3438 			bus_release_resource(
3439 			    dev, rs[i].type, rs[i].rid, res[i]);
3440 			res[i] = NULL;
3441 		}
3442 }
3443 
3444 /**
3445  * @brief Wrapper function for BUS_ALLOC_RESOURCE().
3446  *
3447  * This function simply calls the BUS_ALLOC_RESOURCE() method of the
3448  * parent of @p dev.
3449  */
3450 struct resource *
3451 bus_alloc_resource(device_t dev, int type, int *rid, u_long start, u_long end,
3452     u_long count, u_int flags)
3453 {
3454 	if (dev->parent == NULL)
3455 		return (NULL);
3456 	return (BUS_ALLOC_RESOURCE(dev->parent, dev, type, rid, start, end,
3457 	    count, flags));
3458 }
3459 
3460 /**
3461  * @brief Wrapper function for BUS_ACTIVATE_RESOURCE().
3462  *
3463  * This function simply calls the BUS_ACTIVATE_RESOURCE() method of the
3464  * parent of @p dev.
3465  */
3466 int
3467 bus_activate_resource(device_t dev, int type, int rid, struct resource *r)
3468 {
3469 	if (dev->parent == NULL)
3470 		return (EINVAL);
3471 	return (BUS_ACTIVATE_RESOURCE(dev->parent, dev, type, rid, r));
3472 }
3473 
3474 /**
3475  * @brief Wrapper function for BUS_DEACTIVATE_RESOURCE().
3476  *
3477  * This function simply calls the BUS_DEACTIVATE_RESOURCE() method of the
3478  * parent of @p dev.
3479  */
3480 int
3481 bus_deactivate_resource(device_t dev, int type, int rid, struct resource *r)
3482 {
3483 	if (dev->parent == NULL)
3484 		return (EINVAL);
3485 	return (BUS_DEACTIVATE_RESOURCE(dev->parent, dev, type, rid, r));
3486 }
3487 
3488 /**
3489  * @brief Wrapper function for BUS_RELEASE_RESOURCE().
3490  *
3491  * This function simply calls the BUS_RELEASE_RESOURCE() method of the
3492  * parent of @p dev.
3493  */
3494 int
3495 bus_release_resource(device_t dev, int type, int rid, struct resource *r)
3496 {
3497 	if (dev->parent == NULL)
3498 		return (EINVAL);
3499 	return (BUS_RELEASE_RESOURCE(dev->parent, dev, type, rid, r));
3500 }
3501 
3502 /**
3503  * @brief Wrapper function for BUS_SETUP_INTR().
3504  *
3505  * This function simply calls the BUS_SETUP_INTR() method of the
3506  * parent of @p dev.
3507  */
3508 int
3509 bus_setup_intr(device_t dev, struct resource *r, int flags,
3510     driver_filter_t filter, driver_intr_t handler, void *arg, void **cookiep)
3511 {
3512 	int error;
3513 
3514 	if (dev->parent == NULL)
3515 		return (EINVAL);
3516 	error = BUS_SETUP_INTR(dev->parent, dev, r, flags, filter, handler,
3517 	    arg, cookiep);
3518 	if (error != 0)
3519 		return (error);
3520 	if (handler != NULL && !(flags & INTR_MPSAFE))
3521 		device_printf(dev, "[GIANT-LOCKED]\n");
3522 	if (bootverbose && (flags & INTR_MPSAFE))
3523 		device_printf(dev, "[MPSAFE]\n");
3524 	if (filter != NULL) {
3525 		if (handler == NULL)
3526 			device_printf(dev, "[FILTER]\n");
3527 		else
3528 			device_printf(dev, "[FILTER+ITHREAD]\n");
3529 	} else
3530 		device_printf(dev, "[ITHREAD]\n");
3531 	return (0);
3532 }
3533 
3534 /**
3535  * @brief Wrapper function for BUS_TEARDOWN_INTR().
3536  *
3537  * This function simply calls the BUS_TEARDOWN_INTR() method of the
3538  * parent of @p dev.
3539  */
3540 int
3541 bus_teardown_intr(device_t dev, struct resource *r, void *cookie)
3542 {
3543 	if (dev->parent == NULL)
3544 		return (EINVAL);
3545 	return (BUS_TEARDOWN_INTR(dev->parent, dev, r, cookie));
3546 }
3547 
3548 /**
3549  * @brief Wrapper function for BUS_BIND_INTR().
3550  *
3551  * This function simply calls the BUS_BIND_INTR() method of the
3552  * parent of @p dev.
3553  */
3554 int
3555 bus_bind_intr(device_t dev, struct resource *r, int cpu)
3556 {
3557 	if (dev->parent == NULL)
3558 		return (EINVAL);
3559 	return (BUS_BIND_INTR(dev->parent, dev, r, cpu));
3560 }
3561 
3562 /**
3563  * @brief Wrapper function for BUS_SET_RESOURCE().
3564  *
3565  * This function simply calls the BUS_SET_RESOURCE() method of the
3566  * parent of @p dev.
3567  */
3568 int
3569 bus_set_resource(device_t dev, int type, int rid,
3570     u_long start, u_long count)
3571 {
3572 	return (BUS_SET_RESOURCE(device_get_parent(dev), dev, type, rid,
3573 	    start, count));
3574 }
3575 
3576 /**
3577  * @brief Wrapper function for BUS_GET_RESOURCE().
3578  *
3579  * This function simply calls the BUS_GET_RESOURCE() method of the
3580  * parent of @p dev.
3581  */
3582 int
3583 bus_get_resource(device_t dev, int type, int rid,
3584     u_long *startp, u_long *countp)
3585 {
3586 	return (BUS_GET_RESOURCE(device_get_parent(dev), dev, type, rid,
3587 	    startp, countp));
3588 }
3589 
3590 /**
3591  * @brief Wrapper function for BUS_GET_RESOURCE().
3592  *
3593  * This function simply calls the BUS_GET_RESOURCE() method of the
3594  * parent of @p dev and returns the start value.
3595  */
3596 u_long
3597 bus_get_resource_start(device_t dev, int type, int rid)
3598 {
3599 	u_long start, count;
3600 	int error;
3601 
3602 	error = BUS_GET_RESOURCE(device_get_parent(dev), dev, type, rid,
3603 	    &start, &count);
3604 	if (error)
3605 		return (0);
3606 	return (start);
3607 }
3608 
3609 /**
3610  * @brief Wrapper function for BUS_GET_RESOURCE().
3611  *
3612  * This function simply calls the BUS_GET_RESOURCE() method of the
3613  * parent of @p dev and returns the count value.
3614  */
3615 u_long
3616 bus_get_resource_count(device_t dev, int type, int rid)
3617 {
3618 	u_long start, count;
3619 	int error;
3620 
3621 	error = BUS_GET_RESOURCE(device_get_parent(dev), dev, type, rid,
3622 	    &start, &count);
3623 	if (error)
3624 		return (0);
3625 	return (count);
3626 }
3627 
3628 /**
3629  * @brief Wrapper function for BUS_DELETE_RESOURCE().
3630  *
3631  * This function simply calls the BUS_DELETE_RESOURCE() method of the
3632  * parent of @p dev.
3633  */
3634 void
3635 bus_delete_resource(device_t dev, int type, int rid)
3636 {
3637 	BUS_DELETE_RESOURCE(device_get_parent(dev), dev, type, rid);
3638 }
3639 
3640 /**
3641  * @brief Wrapper function for BUS_CHILD_PRESENT().
3642  *
3643  * This function simply calls the BUS_CHILD_PRESENT() method of the
3644  * parent of @p dev.
3645  */
3646 int
3647 bus_child_present(device_t child)
3648 {
3649 	return (BUS_CHILD_PRESENT(device_get_parent(child), child));
3650 }
3651 
3652 /**
3653  * @brief Wrapper function for BUS_CHILD_PNPINFO_STR().
3654  *
3655  * This function simply calls the BUS_CHILD_PNPINFO_STR() method of the
3656  * parent of @p dev.
3657  */
3658 int
3659 bus_child_pnpinfo_str(device_t child, char *buf, size_t buflen)
3660 {
3661 	device_t parent;
3662 
3663 	parent = device_get_parent(child);
3664 	if (parent == NULL) {
3665 		*buf = '\0';
3666 		return (0);
3667 	}
3668 	return (BUS_CHILD_PNPINFO_STR(parent, child, buf, buflen));
3669 }
3670 
3671 /**
3672  * @brief Wrapper function for BUS_CHILD_LOCATION_STR().
3673  *
3674  * This function simply calls the BUS_CHILD_LOCATION_STR() method of the
3675  * parent of @p dev.
3676  */
3677 int
3678 bus_child_location_str(device_t child, char *buf, size_t buflen)
3679 {
3680 	device_t parent;
3681 
3682 	parent = device_get_parent(child);
3683 	if (parent == NULL) {
3684 		*buf = '\0';
3685 		return (0);
3686 	}
3687 	return (BUS_CHILD_LOCATION_STR(parent, child, buf, buflen));
3688 }
3689 
3690 /**
3691  * @brief Wrapper function for BUS_GET_DMA_TAG().
3692  *
3693  * This function simply calls the BUS_GET_DMA_TAG() method of the
3694  * parent of @p dev.
3695  */
3696 bus_dma_tag_t
3697 bus_get_dma_tag(device_t dev)
3698 {
3699 	device_t parent;
3700 
3701 	parent = device_get_parent(dev);
3702 	if (parent == NULL)
3703 		return (NULL);
3704 	return (BUS_GET_DMA_TAG(parent, dev));
3705 }
3706 
3707 /* Resume all devices and then notify userland that we're up again. */
3708 static int
3709 root_resume(device_t dev)
3710 {
3711 	int error;
3712 
3713 	error = bus_generic_resume(dev);
3714 	if (error == 0)
3715 		devctl_notify("kern", "power", "resume", NULL);
3716 	return (error);
3717 }
3718 
3719 static int
3720 root_print_child(device_t dev, device_t child)
3721 {
3722 	int	retval = 0;
3723 
3724 	retval += bus_print_child_header(dev, child);
3725 	retval += printf("\n");
3726 
3727 	return (retval);
3728 }
3729 
3730 static int
3731 root_setup_intr(device_t dev, device_t child, driver_intr_t *intr, void *arg,
3732     void **cookiep)
3733 {
3734 	/*
3735 	 * If an interrupt mapping gets to here something bad has happened.
3736 	 */
3737 	panic("root_setup_intr");
3738 }
3739 
3740 /*
3741  * If we get here, assume that the device is permanant and really is
3742  * present in the system.  Removable bus drivers are expected to intercept
3743  * this call long before it gets here.  We return -1 so that drivers that
3744  * really care can check vs -1 or some ERRNO returned higher in the food
3745  * chain.
3746  */
3747 static int
3748 root_child_present(device_t dev, device_t child)
3749 {
3750 	return (-1);
3751 }
3752 
3753 static kobj_method_t root_methods[] = {
3754 	/* Device interface */
3755 	KOBJMETHOD(device_shutdown,	bus_generic_shutdown),
3756 	KOBJMETHOD(device_suspend,	bus_generic_suspend),
3757 	KOBJMETHOD(device_resume,	root_resume),
3758 
3759 	/* Bus interface */
3760 	KOBJMETHOD(bus_print_child,	root_print_child),
3761 	KOBJMETHOD(bus_read_ivar,	bus_generic_read_ivar),
3762 	KOBJMETHOD(bus_write_ivar,	bus_generic_write_ivar),
3763 	KOBJMETHOD(bus_setup_intr,	root_setup_intr),
3764 	KOBJMETHOD(bus_child_present,	root_child_present),
3765 
3766 	{ 0, 0 }
3767 };
3768 
3769 static driver_t root_driver = {
3770 	"root",
3771 	root_methods,
3772 	1,			/* no softc */
3773 };
3774 
3775 device_t	root_bus;
3776 devclass_t	root_devclass;
3777 
3778 static int
3779 root_bus_module_handler(module_t mod, int what, void* arg)
3780 {
3781 	switch (what) {
3782 	case MOD_LOAD:
3783 		TAILQ_INIT(&bus_data_devices);
3784 		kobj_class_compile((kobj_class_t) &root_driver);
3785 		root_bus = make_device(NULL, "root", 0);
3786 		root_bus->desc = "System root bus";
3787 		kobj_init((kobj_t) root_bus, (kobj_class_t) &root_driver);
3788 		root_bus->driver = &root_driver;
3789 		root_bus->state = DS_ATTACHED;
3790 		root_devclass = devclass_find_internal("root", NULL, FALSE);
3791 		devinit();
3792 		return (0);
3793 
3794 	case MOD_SHUTDOWN:
3795 		device_shutdown(root_bus);
3796 		return (0);
3797 	default:
3798 		return (EOPNOTSUPP);
3799 	}
3800 
3801 	return (0);
3802 }
3803 
3804 static moduledata_t root_bus_mod = {
3805 	"rootbus",
3806 	root_bus_module_handler,
3807 	0
3808 };
3809 DECLARE_MODULE(rootbus, root_bus_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
3810 
3811 /**
3812  * @brief Automatically configure devices
3813  *
3814  * This function begins the autoconfiguration process by calling
3815  * device_probe_and_attach() for each child of the @c root0 device.
3816  */
3817 void
3818 root_bus_configure(void)
3819 {
3820 	device_t dev;
3821 
3822 	PDEBUG(("."));
3823 
3824 	TAILQ_FOREACH(dev, &root_bus->children, link) {
3825 		device_probe_and_attach(dev);
3826 	}
3827 }
3828 
3829 /**
3830  * @brief Module handler for registering device drivers
3831  *
3832  * This module handler is used to automatically register device
3833  * drivers when modules are loaded. If @p what is MOD_LOAD, it calls
3834  * devclass_add_driver() for the driver described by the
3835  * driver_module_data structure pointed to by @p arg
3836  */
3837 int
3838 driver_module_handler(module_t mod, int what, void *arg)
3839 {
3840 	int error;
3841 	struct driver_module_data *dmd;
3842 	devclass_t bus_devclass;
3843 	kobj_class_t driver;
3844 
3845 	dmd = (struct driver_module_data *)arg;
3846 	bus_devclass = devclass_find_internal(dmd->dmd_busname, NULL, TRUE);
3847 	error = 0;
3848 
3849 	switch (what) {
3850 	case MOD_LOAD:
3851 		if (dmd->dmd_chainevh)
3852 			error = dmd->dmd_chainevh(mod,what,dmd->dmd_chainarg);
3853 
3854 		driver = dmd->dmd_driver;
3855 		PDEBUG(("Loading module: driver %s on bus %s",
3856 		    DRIVERNAME(driver), dmd->dmd_busname));
3857 		error = devclass_add_driver(bus_devclass, driver);
3858 		if (error)
3859 			break;
3860 
3861 		/*
3862 		 * If the driver has any base classes, make the
3863 		 * devclass inherit from the devclass of the driver's
3864 		 * first base class. This will allow the system to
3865 		 * search for drivers in both devclasses for children
3866 		 * of a device using this driver.
3867 		 */
3868 		if (driver->baseclasses) {
3869 			const char *parentname;
3870 			parentname = driver->baseclasses[0]->name;
3871 			*dmd->dmd_devclass =
3872 				devclass_find_internal(driver->name,
3873 				    parentname, TRUE);
3874 		} else {
3875 			*dmd->dmd_devclass =
3876 				devclass_find_internal(driver->name, NULL, TRUE);
3877 		}
3878 		break;
3879 
3880 	case MOD_UNLOAD:
3881 		PDEBUG(("Unloading module: driver %s from bus %s",
3882 		    DRIVERNAME(dmd->dmd_driver),
3883 		    dmd->dmd_busname));
3884 		error = devclass_delete_driver(bus_devclass,
3885 		    dmd->dmd_driver);
3886 
3887 		if (!error && dmd->dmd_chainevh)
3888 			error = dmd->dmd_chainevh(mod,what,dmd->dmd_chainarg);
3889 		break;
3890 	case MOD_QUIESCE:
3891 		PDEBUG(("Quiesce module: driver %s from bus %s",
3892 		    DRIVERNAME(dmd->dmd_driver),
3893 		    dmd->dmd_busname));
3894 		error = devclass_quiesce_driver(bus_devclass,
3895 		    dmd->dmd_driver);
3896 
3897 		if (!error && dmd->dmd_chainevh)
3898 			error = dmd->dmd_chainevh(mod,what,dmd->dmd_chainarg);
3899 		break;
3900 	default:
3901 		error = EOPNOTSUPP;
3902 		break;
3903 	}
3904 
3905 	return (error);
3906 }
3907 
3908 /**
3909  * @brief Enumerate all hinted devices for this bus.
3910  *
3911  * Walks through the hints for this bus and calls the bus_hinted_child
3912  * routine for each one it fines.  It searches first for the specific
3913  * bus that's being probed for hinted children (eg isa0), and then for
3914  * generic children (eg isa).
3915  *
3916  * @param	dev	bus device to enumerate
3917  */
3918 void
3919 bus_enumerate_hinted_children(device_t bus)
3920 {
3921 	int i;
3922 	const char *dname, *busname;
3923 	int dunit;
3924 
3925 	/*
3926 	 * enumerate all devices on the specific bus
3927 	 */
3928 	busname = device_get_nameunit(bus);
3929 	i = 0;
3930 	while (resource_find_match(&i, &dname, &dunit, "at", busname) == 0)
3931 		BUS_HINTED_CHILD(bus, dname, dunit);
3932 
3933 	/*
3934 	 * and all the generic ones.
3935 	 */
3936 	busname = device_get_name(bus);
3937 	i = 0;
3938 	while (resource_find_match(&i, &dname, &dunit, "at", busname) == 0)
3939 		BUS_HINTED_CHILD(bus, dname, dunit);
3940 }
3941 
3942 #ifdef BUS_DEBUG
3943 
3944 /* the _short versions avoid iteration by not calling anything that prints
3945  * more than oneliners. I love oneliners.
3946  */
3947 
3948 static void
3949 print_device_short(device_t dev, int indent)
3950 {
3951 	if (!dev)
3952 		return;
3953 
3954 	indentprintf(("device %d: <%s> %sparent,%schildren,%s%s%s%s%s,%sivars,%ssoftc,busy=%d\n",
3955 	    dev->unit, dev->desc,
3956 	    (dev->parent? "":"no "),
3957 	    (TAILQ_EMPTY(&dev->children)? "no ":""),
3958 	    (dev->flags&DF_ENABLED? "enabled,":"disabled,"),
3959 	    (dev->flags&DF_FIXEDCLASS? "fixed,":""),
3960 	    (dev->flags&DF_WILDCARD? "wildcard,":""),
3961 	    (dev->flags&DF_DESCMALLOCED? "descmalloced,":""),
3962 	    (dev->flags&DF_REBID? "rebiddable,":""),
3963 	    (dev->ivars? "":"no "),
3964 	    (dev->softc? "":"no "),
3965 	    dev->busy));
3966 }
3967 
3968 static void
3969 print_device(device_t dev, int indent)
3970 {
3971 	if (!dev)
3972 		return;
3973 
3974 	print_device_short(dev, indent);
3975 
3976 	indentprintf(("Parent:\n"));
3977 	print_device_short(dev->parent, indent+1);
3978 	indentprintf(("Driver:\n"));
3979 	print_driver_short(dev->driver, indent+1);
3980 	indentprintf(("Devclass:\n"));
3981 	print_devclass_short(dev->devclass, indent+1);
3982 }
3983 
3984 void
3985 print_device_tree_short(device_t dev, int indent)
3986 /* print the device and all its children (indented) */
3987 {
3988 	device_t child;
3989 
3990 	if (!dev)
3991 		return;
3992 
3993 	print_device_short(dev, indent);
3994 
3995 	TAILQ_FOREACH(child, &dev->children, link) {
3996 		print_device_tree_short(child, indent+1);
3997 	}
3998 }
3999 
4000 void
4001 print_device_tree(device_t dev, int indent)
4002 /* print the device and all its children (indented) */
4003 {
4004 	device_t child;
4005 
4006 	if (!dev)
4007 		return;
4008 
4009 	print_device(dev, indent);
4010 
4011 	TAILQ_FOREACH(child, &dev->children, link) {
4012 		print_device_tree(child, indent+1);
4013 	}
4014 }
4015 
4016 static void
4017 print_driver_short(driver_t *driver, int indent)
4018 {
4019 	if (!driver)
4020 		return;
4021 
4022 	indentprintf(("driver %s: softc size = %zd\n",
4023 	    driver->name, driver->size));
4024 }
4025 
4026 static void
4027 print_driver(driver_t *driver, int indent)
4028 {
4029 	if (!driver)
4030 		return;
4031 
4032 	print_driver_short(driver, indent);
4033 }
4034 
4035 
4036 static void
4037 print_driver_list(driver_list_t drivers, int indent)
4038 {
4039 	driverlink_t driver;
4040 
4041 	TAILQ_FOREACH(driver, &drivers, link) {
4042 		print_driver(driver->driver, indent);
4043 	}
4044 }
4045 
4046 static void
4047 print_devclass_short(devclass_t dc, int indent)
4048 {
4049 	if ( !dc )
4050 		return;
4051 
4052 	indentprintf(("devclass %s: max units = %d\n", dc->name, dc->maxunit));
4053 }
4054 
4055 static void
4056 print_devclass(devclass_t dc, int indent)
4057 {
4058 	int i;
4059 
4060 	if ( !dc )
4061 		return;
4062 
4063 	print_devclass_short(dc, indent);
4064 	indentprintf(("Drivers:\n"));
4065 	print_driver_list(dc->drivers, indent+1);
4066 
4067 	indentprintf(("Devices:\n"));
4068 	for (i = 0; i < dc->maxunit; i++)
4069 		if (dc->devices[i])
4070 			print_device(dc->devices[i], indent+1);
4071 }
4072 
4073 void
4074 print_devclass_list_short(void)
4075 {
4076 	devclass_t dc;
4077 
4078 	printf("Short listing of devclasses, drivers & devices:\n");
4079 	TAILQ_FOREACH(dc, &devclasses, link) {
4080 		print_devclass_short(dc, 0);
4081 	}
4082 }
4083 
4084 void
4085 print_devclass_list(void)
4086 {
4087 	devclass_t dc;
4088 
4089 	printf("Full listing of devclasses, drivers & devices:\n");
4090 	TAILQ_FOREACH(dc, &devclasses, link) {
4091 		print_devclass(dc, 0);
4092 	}
4093 }
4094 
4095 #endif
4096 
4097 /*
4098  * User-space access to the device tree.
4099  *
4100  * We implement a small set of nodes:
4101  *
4102  * hw.bus			Single integer read method to obtain the
4103  *				current generation count.
4104  * hw.bus.devices		Reads the entire device tree in flat space.
4105  * hw.bus.rman			Resource manager interface
4106  *
4107  * We might like to add the ability to scan devclasses and/or drivers to
4108  * determine what else is currently loaded/available.
4109  */
4110 
4111 static int
4112 sysctl_bus(SYSCTL_HANDLER_ARGS)
4113 {
4114 	struct u_businfo	ubus;
4115 
4116 	ubus.ub_version = BUS_USER_VERSION;
4117 	ubus.ub_generation = bus_data_generation;
4118 
4119 	return (SYSCTL_OUT(req, &ubus, sizeof(ubus)));
4120 }
4121 SYSCTL_NODE(_hw_bus, OID_AUTO, info, CTLFLAG_RW, sysctl_bus,
4122     "bus-related data");
4123 
4124 static int
4125 sysctl_devices(SYSCTL_HANDLER_ARGS)
4126 {
4127 	int			*name = (int *)arg1;
4128 	u_int			namelen = arg2;
4129 	int			index;
4130 	struct device		*dev;
4131 	struct u_device		udev;	/* XXX this is a bit big */
4132 	int			error;
4133 
4134 	if (namelen != 2)
4135 		return (EINVAL);
4136 
4137 	if (bus_data_generation_check(name[0]))
4138 		return (EINVAL);
4139 
4140 	index = name[1];
4141 
4142 	/*
4143 	 * Scan the list of devices, looking for the requested index.
4144 	 */
4145 	TAILQ_FOREACH(dev, &bus_data_devices, devlink) {
4146 		if (index-- == 0)
4147 			break;
4148 	}
4149 	if (dev == NULL)
4150 		return (ENOENT);
4151 
4152 	/*
4153 	 * Populate the return array.
4154 	 */
4155 	bzero(&udev, sizeof(udev));
4156 	udev.dv_handle = (uintptr_t)dev;
4157 	udev.dv_parent = (uintptr_t)dev->parent;
4158 	if (dev->nameunit != NULL)
4159 		strlcpy(udev.dv_name, dev->nameunit, sizeof(udev.dv_name));
4160 	if (dev->desc != NULL)
4161 		strlcpy(udev.dv_desc, dev->desc, sizeof(udev.dv_desc));
4162 	if (dev->driver != NULL && dev->driver->name != NULL)
4163 		strlcpy(udev.dv_drivername, dev->driver->name,
4164 		    sizeof(udev.dv_drivername));
4165 	bus_child_pnpinfo_str(dev, udev.dv_pnpinfo, sizeof(udev.dv_pnpinfo));
4166 	bus_child_location_str(dev, udev.dv_location, sizeof(udev.dv_location));
4167 	udev.dv_devflags = dev->devflags;
4168 	udev.dv_flags = dev->flags;
4169 	udev.dv_state = dev->state;
4170 	error = SYSCTL_OUT(req, &udev, sizeof(udev));
4171 	return (error);
4172 }
4173 
4174 SYSCTL_NODE(_hw_bus, OID_AUTO, devices, CTLFLAG_RD, sysctl_devices,
4175     "system device tree");
4176 
4177 int
4178 bus_data_generation_check(int generation)
4179 {
4180 	if (generation != bus_data_generation)
4181 		return (1);
4182 
4183 	/* XXX generate optimised lists here? */
4184 	return (0);
4185 }
4186 
4187 void
4188 bus_data_generation_update(void)
4189 {
4190 	bus_data_generation++;
4191 }
4192 
4193 int
4194 bus_free_resource(device_t dev, int type, struct resource *r)
4195 {
4196 	if (r == NULL)
4197 		return (0);
4198 	return (bus_release_resource(dev, type, rman_get_rid(r), r));
4199 }
4200