xref: /freebsd/sys/kern/subr_bus.c (revision 721351876cd4d3a8a700f62d2061331fa951a488)
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.inuse == 1);
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 return this status.
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  * @retval -1		Device already attached
2352  */
2353 int
2354 device_probe(device_t dev)
2355 {
2356 	int error;
2357 
2358 	GIANT_REQUIRED;
2359 
2360 	if (dev->state >= DS_ALIVE && (dev->flags & DF_REBID) == 0)
2361 		return (-1);
2362 
2363 	if (!(dev->flags & DF_ENABLED)) {
2364 		if (bootverbose && device_get_name(dev) != NULL) {
2365 			device_print_prettyname(dev);
2366 			printf("not probed (disabled)\n");
2367 		}
2368 		return (-1);
2369 	}
2370 	if ((error = device_probe_child(dev->parent, dev)) != 0) {
2371 		if (!(dev->flags & DF_DONENOMATCH)) {
2372 			BUS_PROBE_NOMATCH(dev->parent, dev);
2373 			devnomatch(dev);
2374 			dev->flags |= DF_DONENOMATCH;
2375 		}
2376 		return (error);
2377 	}
2378 	return (0);
2379 }
2380 
2381 /**
2382  * @brief Probe a device and attach a driver if possible
2383  *
2384  * calls device_probe() and attaches if that was successful.
2385  */
2386 int
2387 device_probe_and_attach(device_t dev)
2388 {
2389 	int error;
2390 
2391 	GIANT_REQUIRED;
2392 
2393 	error = device_probe(dev);
2394 	if (error == -1)
2395 		return (0);
2396 	else if (error != 0)
2397 		return (error);
2398 	return (device_attach(dev));
2399 }
2400 
2401 /**
2402  * @brief Attach a device driver to a device
2403  *
2404  * This function is a wrapper around the DEVICE_ATTACH() driver
2405  * method. In addition to calling DEVICE_ATTACH(), it initialises the
2406  * device's sysctl tree, optionally prints a description of the device
2407  * and queues a notification event for user-based device management
2408  * services.
2409  *
2410  * Normally this function is only called internally from
2411  * device_probe_and_attach().
2412  *
2413  * @param dev		the device to initialise
2414  *
2415  * @retval 0		success
2416  * @retval ENXIO	no driver was found
2417  * @retval ENOMEM	memory allocation failure
2418  * @retval non-zero	some other unix error code
2419  */
2420 int
2421 device_attach(device_t dev)
2422 {
2423 	int error;
2424 
2425 	device_sysctl_init(dev);
2426 	if (!device_is_quiet(dev))
2427 		device_print_child(dev->parent, dev);
2428 	if ((error = DEVICE_ATTACH(dev)) != 0) {
2429 		printf("device_attach: %s%d attach returned %d\n",
2430 		    dev->driver->name, dev->unit, error);
2431 		/* Unset the class; set in device_probe_child */
2432 		if (dev->devclass == NULL)
2433 			device_set_devclass(dev, NULL);
2434 		device_set_driver(dev, NULL);
2435 		device_sysctl_fini(dev);
2436 		dev->state = DS_NOTPRESENT;
2437 		return (error);
2438 	}
2439 	device_sysctl_update(dev);
2440 	dev->state = DS_ATTACHED;
2441 	devadded(dev);
2442 	return (0);
2443 }
2444 
2445 /**
2446  * @brief Detach a driver from a device
2447  *
2448  * This function is a wrapper around the DEVICE_DETACH() driver
2449  * method. If the call to DEVICE_DETACH() succeeds, it calls
2450  * BUS_CHILD_DETACHED() for the parent of @p dev, queues a
2451  * notification event for user-based device management services and
2452  * cleans up the device's sysctl tree.
2453  *
2454  * @param dev		the device to un-initialise
2455  *
2456  * @retval 0		success
2457  * @retval ENXIO	no driver was found
2458  * @retval ENOMEM	memory allocation failure
2459  * @retval non-zero	some other unix error code
2460  */
2461 int
2462 device_detach(device_t dev)
2463 {
2464 	int error;
2465 
2466 	GIANT_REQUIRED;
2467 
2468 	PDEBUG(("%s", DEVICENAME(dev)));
2469 	if (dev->state == DS_BUSY)
2470 		return (EBUSY);
2471 	if (dev->state != DS_ATTACHED)
2472 		return (0);
2473 
2474 	if ((error = DEVICE_DETACH(dev)) != 0)
2475 		return (error);
2476 	devremoved(dev);
2477 	device_printf(dev, "detached\n");
2478 	if (dev->parent)
2479 		BUS_CHILD_DETACHED(dev->parent, dev);
2480 
2481 	if (!(dev->flags & DF_FIXEDCLASS))
2482 		devclass_delete_device(dev->devclass, dev);
2483 
2484 	dev->state = DS_NOTPRESENT;
2485 	device_set_driver(dev, NULL);
2486 	device_set_desc(dev, NULL);
2487 	device_sysctl_fini(dev);
2488 
2489 	return (0);
2490 }
2491 
2492 /**
2493  * @brief Tells a driver to quiesce itself.
2494  *
2495  * This function is a wrapper around the DEVICE_QUIESCE() driver
2496  * method. If the call to DEVICE_QUIESCE() succeeds.
2497  *
2498  * @param dev		the device to quiesce
2499  *
2500  * @retval 0		success
2501  * @retval ENXIO	no driver was found
2502  * @retval ENOMEM	memory allocation failure
2503  * @retval non-zero	some other unix error code
2504  */
2505 int
2506 device_quiesce(device_t dev)
2507 {
2508 
2509 	PDEBUG(("%s", DEVICENAME(dev)));
2510 	if (dev->state == DS_BUSY)
2511 		return (EBUSY);
2512 	if (dev->state != DS_ATTACHED)
2513 		return (0);
2514 
2515 	return (DEVICE_QUIESCE(dev));
2516 }
2517 
2518 /**
2519  * @brief Notify a device of system shutdown
2520  *
2521  * This function calls the DEVICE_SHUTDOWN() driver method if the
2522  * device currently has an attached driver.
2523  *
2524  * @returns the value returned by DEVICE_SHUTDOWN()
2525  */
2526 int
2527 device_shutdown(device_t dev)
2528 {
2529 	if (dev->state < DS_ATTACHED)
2530 		return (0);
2531 	return (DEVICE_SHUTDOWN(dev));
2532 }
2533 
2534 /**
2535  * @brief Set the unit number of a device
2536  *
2537  * This function can be used to override the unit number used for a
2538  * device (e.g. to wire a device to a pre-configured unit number).
2539  */
2540 int
2541 device_set_unit(device_t dev, int unit)
2542 {
2543 	devclass_t dc;
2544 	int err;
2545 
2546 	dc = device_get_devclass(dev);
2547 	if (unit < dc->maxunit && dc->devices[unit])
2548 		return (EBUSY);
2549 	err = devclass_delete_device(dc, dev);
2550 	if (err)
2551 		return (err);
2552 	dev->unit = unit;
2553 	err = devclass_add_device(dc, dev);
2554 	if (err)
2555 		return (err);
2556 
2557 	bus_data_generation_update();
2558 	return (0);
2559 }
2560 
2561 /*======================================*/
2562 /*
2563  * Some useful method implementations to make life easier for bus drivers.
2564  */
2565 
2566 /**
2567  * @brief Initialise a resource list.
2568  *
2569  * @param rl		the resource list to initialise
2570  */
2571 void
2572 resource_list_init(struct resource_list *rl)
2573 {
2574 	STAILQ_INIT(rl);
2575 }
2576 
2577 /**
2578  * @brief Reclaim memory used by a resource list.
2579  *
2580  * This function frees the memory for all resource entries on the list
2581  * (if any).
2582  *
2583  * @param rl		the resource list to free
2584  */
2585 void
2586 resource_list_free(struct resource_list *rl)
2587 {
2588 	struct resource_list_entry *rle;
2589 
2590 	while ((rle = STAILQ_FIRST(rl)) != NULL) {
2591 		if (rle->res)
2592 			panic("resource_list_free: resource entry is busy");
2593 		STAILQ_REMOVE_HEAD(rl, link);
2594 		free(rle, M_BUS);
2595 	}
2596 }
2597 
2598 /**
2599  * @brief Add a resource entry.
2600  *
2601  * This function adds a resource entry using the given @p type, @p
2602  * start, @p end and @p count values. A rid value is chosen by
2603  * searching sequentially for the first unused rid starting at zero.
2604  *
2605  * @param rl		the resource list to edit
2606  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
2607  * @param start		the start address of the resource
2608  * @param end		the end address of the resource
2609  * @param count		XXX end-start+1
2610  */
2611 int
2612 resource_list_add_next(struct resource_list *rl, int type, u_long start,
2613     u_long end, u_long count)
2614 {
2615 	int rid;
2616 
2617 	rid = 0;
2618 	while (resource_list_find(rl, type, rid) != NULL)
2619 		rid++;
2620 	resource_list_add(rl, type, rid, start, end, count);
2621 	return (rid);
2622 }
2623 
2624 /**
2625  * @brief Add or modify a resource entry.
2626  *
2627  * If an existing entry exists with the same type and rid, it will be
2628  * modified using the given values of @p start, @p end and @p
2629  * count. If no entry exists, a new one will be created using the
2630  * given values.  The resource list entry that matches is then returned.
2631  *
2632  * @param rl		the resource list to edit
2633  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
2634  * @param rid		the resource identifier
2635  * @param start		the start address of the resource
2636  * @param end		the end address of the resource
2637  * @param count		XXX end-start+1
2638  */
2639 struct resource_list_entry *
2640 resource_list_add(struct resource_list *rl, int type, int rid,
2641     u_long start, u_long end, u_long count)
2642 {
2643 	struct resource_list_entry *rle;
2644 
2645 	rle = resource_list_find(rl, type, rid);
2646 	if (!rle) {
2647 		rle = malloc(sizeof(struct resource_list_entry), M_BUS,
2648 		    M_NOWAIT);
2649 		if (!rle)
2650 			panic("resource_list_add: can't record entry");
2651 		STAILQ_INSERT_TAIL(rl, rle, link);
2652 		rle->type = type;
2653 		rle->rid = rid;
2654 		rle->res = NULL;
2655 	}
2656 
2657 	if (rle->res)
2658 		panic("resource_list_add: resource entry is busy");
2659 
2660 	rle->start = start;
2661 	rle->end = end;
2662 	rle->count = count;
2663 	return (rle);
2664 }
2665 
2666 /**
2667  * @brief Find a resource entry by type and rid.
2668  *
2669  * @param rl		the resource list to search
2670  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
2671  * @param rid		the resource identifier
2672  *
2673  * @returns the resource entry pointer or NULL if there is no such
2674  * entry.
2675  */
2676 struct resource_list_entry *
2677 resource_list_find(struct resource_list *rl, int type, int rid)
2678 {
2679 	struct resource_list_entry *rle;
2680 
2681 	STAILQ_FOREACH(rle, rl, link) {
2682 		if (rle->type == type && rle->rid == rid)
2683 			return (rle);
2684 	}
2685 	return (NULL);
2686 }
2687 
2688 /**
2689  * @brief Delete a resource entry.
2690  *
2691  * @param rl		the resource list to edit
2692  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
2693  * @param rid		the resource identifier
2694  */
2695 void
2696 resource_list_delete(struct resource_list *rl, int type, int rid)
2697 {
2698 	struct resource_list_entry *rle = resource_list_find(rl, type, rid);
2699 
2700 	if (rle) {
2701 		if (rle->res != NULL)
2702 			panic("resource_list_delete: resource has not been released");
2703 		STAILQ_REMOVE(rl, rle, resource_list_entry, link);
2704 		free(rle, M_BUS);
2705 	}
2706 }
2707 
2708 /**
2709  * @brief Helper function for implementing BUS_ALLOC_RESOURCE()
2710  *
2711  * Implement BUS_ALLOC_RESOURCE() by looking up a resource from the list
2712  * and passing the allocation up to the parent of @p bus. This assumes
2713  * that the first entry of @c device_get_ivars(child) is a struct
2714  * resource_list. This also handles 'passthrough' allocations where a
2715  * child is a remote descendant of bus by passing the allocation up to
2716  * the parent of bus.
2717  *
2718  * Typically, a bus driver would store a list of child resources
2719  * somewhere in the child device's ivars (see device_get_ivars()) and
2720  * its implementation of BUS_ALLOC_RESOURCE() would find that list and
2721  * then call resource_list_alloc() to perform the allocation.
2722  *
2723  * @param rl		the resource list to allocate from
2724  * @param bus		the parent device of @p child
2725  * @param child		the device which is requesting an allocation
2726  * @param type		the type of resource to allocate
2727  * @param rid		a pointer to the resource identifier
2728  * @param start		hint at the start of the resource range - pass
2729  *			@c 0UL for any start address
2730  * @param end		hint at the end of the resource range - pass
2731  *			@c ~0UL for any end address
2732  * @param count		hint at the size of range required - pass @c 1
2733  *			for any size
2734  * @param flags		any extra flags to control the resource
2735  *			allocation - see @c RF_XXX flags in
2736  *			<sys/rman.h> for details
2737  *
2738  * @returns		the resource which was allocated or @c NULL if no
2739  *			resource could be allocated
2740  */
2741 struct resource *
2742 resource_list_alloc(struct resource_list *rl, device_t bus, device_t child,
2743     int type, int *rid, u_long start, u_long end, u_long count, u_int flags)
2744 {
2745 	struct resource_list_entry *rle = NULL;
2746 	int passthrough = (device_get_parent(child) != bus);
2747 	int isdefault = (start == 0UL && end == ~0UL);
2748 
2749 	if (passthrough) {
2750 		return (BUS_ALLOC_RESOURCE(device_get_parent(bus), child,
2751 		    type, rid, start, end, count, flags));
2752 	}
2753 
2754 	rle = resource_list_find(rl, type, *rid);
2755 
2756 	if (!rle)
2757 		return (NULL);		/* no resource of that type/rid */
2758 
2759 	if (rle->res)
2760 		panic("resource_list_alloc: resource entry is busy");
2761 
2762 	if (isdefault) {
2763 		start = rle->start;
2764 		count = ulmax(count, rle->count);
2765 		end = ulmax(rle->end, start + count - 1);
2766 	}
2767 
2768 	rle->res = BUS_ALLOC_RESOURCE(device_get_parent(bus), child,
2769 	    type, rid, start, end, count, flags);
2770 
2771 	/*
2772 	 * Record the new range.
2773 	 */
2774 	if (rle->res) {
2775 		rle->start = rman_get_start(rle->res);
2776 		rle->end = rman_get_end(rle->res);
2777 		rle->count = count;
2778 	}
2779 
2780 	return (rle->res);
2781 }
2782 
2783 /**
2784  * @brief Helper function for implementing BUS_RELEASE_RESOURCE()
2785  *
2786  * Implement BUS_RELEASE_RESOURCE() using a resource list. Normally
2787  * used with resource_list_alloc().
2788  *
2789  * @param rl		the resource list which was allocated from
2790  * @param bus		the parent device of @p child
2791  * @param child		the device which is requesting a release
2792  * @param type		the type of resource to allocate
2793  * @param rid		the resource identifier
2794  * @param res		the resource to release
2795  *
2796  * @retval 0		success
2797  * @retval non-zero	a standard unix error code indicating what
2798  *			error condition prevented the operation
2799  */
2800 int
2801 resource_list_release(struct resource_list *rl, device_t bus, device_t child,
2802     int type, int rid, struct resource *res)
2803 {
2804 	struct resource_list_entry *rle = NULL;
2805 	int passthrough = (device_get_parent(child) != bus);
2806 	int error;
2807 
2808 	if (passthrough) {
2809 		return (BUS_RELEASE_RESOURCE(device_get_parent(bus), child,
2810 		    type, rid, res));
2811 	}
2812 
2813 	rle = resource_list_find(rl, type, rid);
2814 
2815 	if (!rle)
2816 		panic("resource_list_release: can't find resource");
2817 	if (!rle->res)
2818 		panic("resource_list_release: resource entry is not busy");
2819 
2820 	error = BUS_RELEASE_RESOURCE(device_get_parent(bus), child,
2821 	    type, rid, res);
2822 	if (error)
2823 		return (error);
2824 
2825 	rle->res = NULL;
2826 	return (0);
2827 }
2828 
2829 /**
2830  * @brief Print a description of resources in a resource list
2831  *
2832  * Print all resources of a specified type, for use in BUS_PRINT_CHILD().
2833  * The name is printed if at least one resource of the given type is available.
2834  * The format is used to print resource start and end.
2835  *
2836  * @param rl		the resource list to print
2837  * @param name		the name of @p type, e.g. @c "memory"
2838  * @param type		type type of resource entry to print
2839  * @param format	printf(9) format string to print resource
2840  *			start and end values
2841  *
2842  * @returns		the number of characters printed
2843  */
2844 int
2845 resource_list_print_type(struct resource_list *rl, const char *name, int type,
2846     const char *format)
2847 {
2848 	struct resource_list_entry *rle;
2849 	int printed, retval;
2850 
2851 	printed = 0;
2852 	retval = 0;
2853 	/* Yes, this is kinda cheating */
2854 	STAILQ_FOREACH(rle, rl, link) {
2855 		if (rle->type == type) {
2856 			if (printed == 0)
2857 				retval += printf(" %s ", name);
2858 			else
2859 				retval += printf(",");
2860 			printed++;
2861 			retval += printf(format, rle->start);
2862 			if (rle->count > 1) {
2863 				retval += printf("-");
2864 				retval += printf(format, rle->start +
2865 						 rle->count - 1);
2866 			}
2867 		}
2868 	}
2869 	return (retval);
2870 }
2871 
2872 /**
2873  * @brief Releases all the resources in a list.
2874  *
2875  * @param rl		The resource list to purge.
2876  *
2877  * @returns		nothing
2878  */
2879 void
2880 resource_list_purge(struct resource_list *rl)
2881 {
2882 	struct resource_list_entry *rle;
2883 
2884 	while ((rle = STAILQ_FIRST(rl)) != NULL) {
2885 		if (rle->res)
2886 			bus_release_resource(rman_get_device(rle->res),
2887 			    rle->type, rle->rid, rle->res);
2888 		STAILQ_REMOVE_HEAD(rl, link);
2889 		free(rle, M_BUS);
2890 	}
2891 }
2892 
2893 device_t
2894 bus_generic_add_child(device_t dev, int order, const char *name, int unit)
2895 {
2896 
2897 	return (device_add_child_ordered(dev, order, name, unit));
2898 }
2899 
2900 /**
2901  * @brief Helper function for implementing DEVICE_PROBE()
2902  *
2903  * This function can be used to help implement the DEVICE_PROBE() for
2904  * a bus (i.e. a device which has other devices attached to it). It
2905  * calls the DEVICE_IDENTIFY() method of each driver in the device's
2906  * devclass.
2907  */
2908 int
2909 bus_generic_probe(device_t dev)
2910 {
2911 	devclass_t dc = dev->devclass;
2912 	driverlink_t dl;
2913 
2914 	TAILQ_FOREACH(dl, &dc->drivers, link) {
2915 		DEVICE_IDENTIFY(dl->driver, dev);
2916 	}
2917 
2918 	return (0);
2919 }
2920 
2921 /**
2922  * @brief Helper function for implementing DEVICE_ATTACH()
2923  *
2924  * This function can be used to help implement the DEVICE_ATTACH() for
2925  * a bus. It calls device_probe_and_attach() for each of the device's
2926  * children.
2927  */
2928 int
2929 bus_generic_attach(device_t dev)
2930 {
2931 	device_t child;
2932 
2933 	TAILQ_FOREACH(child, &dev->children, link) {
2934 		device_probe_and_attach(child);
2935 	}
2936 
2937 	return (0);
2938 }
2939 
2940 /**
2941  * @brief Helper function for implementing DEVICE_DETACH()
2942  *
2943  * This function can be used to help implement the DEVICE_DETACH() for
2944  * a bus. It calls device_detach() for each of the device's
2945  * children.
2946  */
2947 int
2948 bus_generic_detach(device_t dev)
2949 {
2950 	device_t child;
2951 	int error;
2952 
2953 	if (dev->state != DS_ATTACHED)
2954 		return (EBUSY);
2955 
2956 	TAILQ_FOREACH(child, &dev->children, link) {
2957 		if ((error = device_detach(child)) != 0)
2958 			return (error);
2959 	}
2960 
2961 	return (0);
2962 }
2963 
2964 /**
2965  * @brief Helper function for implementing DEVICE_SHUTDOWN()
2966  *
2967  * This function can be used to help implement the DEVICE_SHUTDOWN()
2968  * for a bus. It calls device_shutdown() for each of the device's
2969  * children.
2970  */
2971 int
2972 bus_generic_shutdown(device_t dev)
2973 {
2974 	device_t child;
2975 
2976 	TAILQ_FOREACH(child, &dev->children, link) {
2977 		device_shutdown(child);
2978 	}
2979 
2980 	return (0);
2981 }
2982 
2983 /**
2984  * @brief Helper function for implementing DEVICE_SUSPEND()
2985  *
2986  * This function can be used to help implement the DEVICE_SUSPEND()
2987  * for a bus. It calls DEVICE_SUSPEND() for each of the device's
2988  * children. If any call to DEVICE_SUSPEND() fails, the suspend
2989  * operation is aborted and any devices which were suspended are
2990  * resumed immediately by calling their DEVICE_RESUME() methods.
2991  */
2992 int
2993 bus_generic_suspend(device_t dev)
2994 {
2995 	int		error;
2996 	device_t	child, child2;
2997 
2998 	TAILQ_FOREACH(child, &dev->children, link) {
2999 		error = DEVICE_SUSPEND(child);
3000 		if (error) {
3001 			for (child2 = TAILQ_FIRST(&dev->children);
3002 			     child2 && child2 != child;
3003 			     child2 = TAILQ_NEXT(child2, link))
3004 				DEVICE_RESUME(child2);
3005 			return (error);
3006 		}
3007 	}
3008 	return (0);
3009 }
3010 
3011 /**
3012  * @brief Helper function for implementing DEVICE_RESUME()
3013  *
3014  * This function can be used to help implement the DEVICE_RESUME() for
3015  * a bus. It calls DEVICE_RESUME() on each of the device's children.
3016  */
3017 int
3018 bus_generic_resume(device_t dev)
3019 {
3020 	device_t	child;
3021 
3022 	TAILQ_FOREACH(child, &dev->children, link) {
3023 		DEVICE_RESUME(child);
3024 		/* if resume fails, there's nothing we can usefully do... */
3025 	}
3026 	return (0);
3027 }
3028 
3029 /**
3030  * @brief Helper function for implementing BUS_PRINT_CHILD().
3031  *
3032  * This function prints the first part of the ascii representation of
3033  * @p child, including its name, unit and description (if any - see
3034  * device_set_desc()).
3035  *
3036  * @returns the number of characters printed
3037  */
3038 int
3039 bus_print_child_header(device_t dev, device_t child)
3040 {
3041 	int	retval = 0;
3042 
3043 	if (device_get_desc(child)) {
3044 		retval += device_printf(child, "<%s>", device_get_desc(child));
3045 	} else {
3046 		retval += printf("%s", device_get_nameunit(child));
3047 	}
3048 
3049 	return (retval);
3050 }
3051 
3052 /**
3053  * @brief Helper function for implementing BUS_PRINT_CHILD().
3054  *
3055  * This function prints the last part of the ascii representation of
3056  * @p child, which consists of the string @c " on " followed by the
3057  * name and unit of the @p dev.
3058  *
3059  * @returns the number of characters printed
3060  */
3061 int
3062 bus_print_child_footer(device_t dev, device_t child)
3063 {
3064 	return (printf(" on %s\n", device_get_nameunit(dev)));
3065 }
3066 
3067 /**
3068  * @brief Helper function for implementing BUS_PRINT_CHILD().
3069  *
3070  * This function simply calls bus_print_child_header() followed by
3071  * bus_print_child_footer().
3072  *
3073  * @returns the number of characters printed
3074  */
3075 int
3076 bus_generic_print_child(device_t dev, device_t child)
3077 {
3078 	int	retval = 0;
3079 
3080 	retval += bus_print_child_header(dev, child);
3081 	retval += bus_print_child_footer(dev, child);
3082 
3083 	return (retval);
3084 }
3085 
3086 /**
3087  * @brief Stub function for implementing BUS_READ_IVAR().
3088  *
3089  * @returns ENOENT
3090  */
3091 int
3092 bus_generic_read_ivar(device_t dev, device_t child, int index,
3093     uintptr_t * result)
3094 {
3095 	return (ENOENT);
3096 }
3097 
3098 /**
3099  * @brief Stub function for implementing BUS_WRITE_IVAR().
3100  *
3101  * @returns ENOENT
3102  */
3103 int
3104 bus_generic_write_ivar(device_t dev, device_t child, int index,
3105     uintptr_t value)
3106 {
3107 	return (ENOENT);
3108 }
3109 
3110 /**
3111  * @brief Stub function for implementing BUS_GET_RESOURCE_LIST().
3112  *
3113  * @returns NULL
3114  */
3115 struct resource_list *
3116 bus_generic_get_resource_list(device_t dev, device_t child)
3117 {
3118 	return (NULL);
3119 }
3120 
3121 /**
3122  * @brief Helper function for implementing BUS_DRIVER_ADDED().
3123  *
3124  * This implementation of BUS_DRIVER_ADDED() simply calls the driver's
3125  * DEVICE_IDENTIFY() method to allow it to add new children to the bus
3126  * and then calls device_probe_and_attach() for each unattached child.
3127  */
3128 void
3129 bus_generic_driver_added(device_t dev, driver_t *driver)
3130 {
3131 	device_t child;
3132 
3133 	DEVICE_IDENTIFY(driver, dev);
3134 	TAILQ_FOREACH(child, &dev->children, link) {
3135 		if (child->state == DS_NOTPRESENT ||
3136 		    (child->flags & DF_REBID))
3137 			device_probe_and_attach(child);
3138 	}
3139 }
3140 
3141 /**
3142  * @brief Helper function for implementing BUS_SETUP_INTR().
3143  *
3144  * This simple implementation of BUS_SETUP_INTR() simply calls the
3145  * BUS_SETUP_INTR() method of the parent of @p dev.
3146  */
3147 int
3148 bus_generic_setup_intr(device_t dev, device_t child, struct resource *irq,
3149     int flags, driver_filter_t *filter, driver_intr_t *intr, void *arg,
3150     void **cookiep)
3151 {
3152 	/* Propagate up the bus hierarchy until someone handles it. */
3153 	if (dev->parent)
3154 		return (BUS_SETUP_INTR(dev->parent, child, irq, flags,
3155 		    filter, intr, arg, cookiep));
3156 	return (EINVAL);
3157 }
3158 
3159 /**
3160  * @brief Helper function for implementing BUS_TEARDOWN_INTR().
3161  *
3162  * This simple implementation of BUS_TEARDOWN_INTR() simply calls the
3163  * BUS_TEARDOWN_INTR() method of the parent of @p dev.
3164  */
3165 int
3166 bus_generic_teardown_intr(device_t dev, device_t child, struct resource *irq,
3167     void *cookie)
3168 {
3169 	/* Propagate up the bus hierarchy until someone handles it. */
3170 	if (dev->parent)
3171 		return (BUS_TEARDOWN_INTR(dev->parent, child, irq, cookie));
3172 	return (EINVAL);
3173 }
3174 
3175 /**
3176  * @brief Helper function for implementing BUS_ALLOC_RESOURCE().
3177  *
3178  * This simple implementation of BUS_ALLOC_RESOURCE() simply calls the
3179  * BUS_ALLOC_RESOURCE() method of the parent of @p dev.
3180  */
3181 struct resource *
3182 bus_generic_alloc_resource(device_t dev, device_t child, int type, int *rid,
3183     u_long start, u_long end, u_long count, u_int flags)
3184 {
3185 	/* Propagate up the bus hierarchy until someone handles it. */
3186 	if (dev->parent)
3187 		return (BUS_ALLOC_RESOURCE(dev->parent, child, type, rid,
3188 		    start, end, count, flags));
3189 	return (NULL);
3190 }
3191 
3192 /**
3193  * @brief Helper function for implementing BUS_RELEASE_RESOURCE().
3194  *
3195  * This simple implementation of BUS_RELEASE_RESOURCE() simply calls the
3196  * BUS_RELEASE_RESOURCE() method of the parent of @p dev.
3197  */
3198 int
3199 bus_generic_release_resource(device_t dev, device_t child, int type, int rid,
3200     struct resource *r)
3201 {
3202 	/* Propagate up the bus hierarchy until someone handles it. */
3203 	if (dev->parent)
3204 		return (BUS_RELEASE_RESOURCE(dev->parent, child, type, rid,
3205 		    r));
3206 	return (EINVAL);
3207 }
3208 
3209 /**
3210  * @brief Helper function for implementing BUS_ACTIVATE_RESOURCE().
3211  *
3212  * This simple implementation of BUS_ACTIVATE_RESOURCE() simply calls the
3213  * BUS_ACTIVATE_RESOURCE() method of the parent of @p dev.
3214  */
3215 int
3216 bus_generic_activate_resource(device_t dev, device_t child, int type, int rid,
3217     struct resource *r)
3218 {
3219 	/* Propagate up the bus hierarchy until someone handles it. */
3220 	if (dev->parent)
3221 		return (BUS_ACTIVATE_RESOURCE(dev->parent, child, type, rid,
3222 		    r));
3223 	return (EINVAL);
3224 }
3225 
3226 /**
3227  * @brief Helper function for implementing BUS_DEACTIVATE_RESOURCE().
3228  *
3229  * This simple implementation of BUS_DEACTIVATE_RESOURCE() simply calls the
3230  * BUS_DEACTIVATE_RESOURCE() method of the parent of @p dev.
3231  */
3232 int
3233 bus_generic_deactivate_resource(device_t dev, device_t child, int type,
3234     int rid, struct resource *r)
3235 {
3236 	/* Propagate up the bus hierarchy until someone handles it. */
3237 	if (dev->parent)
3238 		return (BUS_DEACTIVATE_RESOURCE(dev->parent, child, type, rid,
3239 		    r));
3240 	return (EINVAL);
3241 }
3242 
3243 /**
3244  * @brief Helper function for implementing BUS_BIND_INTR().
3245  *
3246  * This simple implementation of BUS_BIND_INTR() simply calls the
3247  * BUS_BIND_INTR() method of the parent of @p dev.
3248  */
3249 int
3250 bus_generic_bind_intr(device_t dev, device_t child, struct resource *irq,
3251     int cpu)
3252 {
3253 
3254 	/* Propagate up the bus hierarchy until someone handles it. */
3255 	if (dev->parent)
3256 		return (BUS_BIND_INTR(dev->parent, child, irq, cpu));
3257 	return (EINVAL);
3258 }
3259 
3260 /**
3261  * @brief Helper function for implementing BUS_CONFIG_INTR().
3262  *
3263  * This simple implementation of BUS_CONFIG_INTR() simply calls the
3264  * BUS_CONFIG_INTR() method of the parent of @p dev.
3265  */
3266 int
3267 bus_generic_config_intr(device_t dev, int irq, enum intr_trigger trig,
3268     enum intr_polarity pol)
3269 {
3270 
3271 	/* Propagate up the bus hierarchy until someone handles it. */
3272 	if (dev->parent)
3273 		return (BUS_CONFIG_INTR(dev->parent, irq, trig, pol));
3274 	return (EINVAL);
3275 }
3276 
3277 /**
3278  * @brief Helper function for implementing BUS_GET_DMA_TAG().
3279  *
3280  * This simple implementation of BUS_GET_DMA_TAG() simply calls the
3281  * BUS_GET_DMA_TAG() method of the parent of @p dev.
3282  */
3283 bus_dma_tag_t
3284 bus_generic_get_dma_tag(device_t dev, device_t child)
3285 {
3286 
3287 	/* Propagate up the bus hierarchy until someone handles it. */
3288 	if (dev->parent != NULL)
3289 		return (BUS_GET_DMA_TAG(dev->parent, child));
3290 	return (NULL);
3291 }
3292 
3293 /**
3294  * @brief Helper function for implementing BUS_GET_RESOURCE().
3295  *
3296  * This implementation of BUS_GET_RESOURCE() uses the
3297  * resource_list_find() function to do most of the work. It calls
3298  * BUS_GET_RESOURCE_LIST() to find a suitable resource list to
3299  * search.
3300  */
3301 int
3302 bus_generic_rl_get_resource(device_t dev, device_t child, int type, int rid,
3303     u_long *startp, u_long *countp)
3304 {
3305 	struct resource_list *		rl = NULL;
3306 	struct resource_list_entry *	rle = NULL;
3307 
3308 	rl = BUS_GET_RESOURCE_LIST(dev, child);
3309 	if (!rl)
3310 		return (EINVAL);
3311 
3312 	rle = resource_list_find(rl, type, rid);
3313 	if (!rle)
3314 		return (ENOENT);
3315 
3316 	if (startp)
3317 		*startp = rle->start;
3318 	if (countp)
3319 		*countp = rle->count;
3320 
3321 	return (0);
3322 }
3323 
3324 /**
3325  * @brief Helper function for implementing BUS_SET_RESOURCE().
3326  *
3327  * This implementation of BUS_SET_RESOURCE() uses the
3328  * resource_list_add() function to do most of the work. It calls
3329  * BUS_GET_RESOURCE_LIST() to find a suitable resource list to
3330  * edit.
3331  */
3332 int
3333 bus_generic_rl_set_resource(device_t dev, device_t child, int type, int rid,
3334     u_long start, u_long count)
3335 {
3336 	struct resource_list *		rl = NULL;
3337 
3338 	rl = BUS_GET_RESOURCE_LIST(dev, child);
3339 	if (!rl)
3340 		return (EINVAL);
3341 
3342 	resource_list_add(rl, type, rid, start, (start + count - 1), count);
3343 
3344 	return (0);
3345 }
3346 
3347 /**
3348  * @brief Helper function for implementing BUS_DELETE_RESOURCE().
3349  *
3350  * This implementation of BUS_DELETE_RESOURCE() uses the
3351  * resource_list_delete() function to do most of the work. It calls
3352  * BUS_GET_RESOURCE_LIST() to find a suitable resource list to
3353  * edit.
3354  */
3355 void
3356 bus_generic_rl_delete_resource(device_t dev, device_t child, int type, int rid)
3357 {
3358 	struct resource_list *		rl = NULL;
3359 
3360 	rl = BUS_GET_RESOURCE_LIST(dev, child);
3361 	if (!rl)
3362 		return;
3363 
3364 	resource_list_delete(rl, type, rid);
3365 
3366 	return;
3367 }
3368 
3369 /**
3370  * @brief Helper function for implementing BUS_RELEASE_RESOURCE().
3371  *
3372  * This implementation of BUS_RELEASE_RESOURCE() uses the
3373  * resource_list_release() function to do most of the work. It calls
3374  * BUS_GET_RESOURCE_LIST() to find a suitable resource list.
3375  */
3376 int
3377 bus_generic_rl_release_resource(device_t dev, device_t child, int type,
3378     int rid, struct resource *r)
3379 {
3380 	struct resource_list *		rl = NULL;
3381 
3382 	rl = BUS_GET_RESOURCE_LIST(dev, child);
3383 	if (!rl)
3384 		return (EINVAL);
3385 
3386 	return (resource_list_release(rl, dev, child, type, rid, r));
3387 }
3388 
3389 /**
3390  * @brief Helper function for implementing BUS_ALLOC_RESOURCE().
3391  *
3392  * This implementation of BUS_ALLOC_RESOURCE() uses the
3393  * resource_list_alloc() function to do most of the work. It calls
3394  * BUS_GET_RESOURCE_LIST() to find a suitable resource list.
3395  */
3396 struct resource *
3397 bus_generic_rl_alloc_resource(device_t dev, device_t child, int type,
3398     int *rid, u_long start, u_long end, u_long count, u_int flags)
3399 {
3400 	struct resource_list *		rl = NULL;
3401 
3402 	rl = BUS_GET_RESOURCE_LIST(dev, child);
3403 	if (!rl)
3404 		return (NULL);
3405 
3406 	return (resource_list_alloc(rl, dev, child, type, rid,
3407 	    start, end, count, flags));
3408 }
3409 
3410 /**
3411  * @brief Helper function for implementing BUS_CHILD_PRESENT().
3412  *
3413  * This simple implementation of BUS_CHILD_PRESENT() simply calls the
3414  * BUS_CHILD_PRESENT() method of the parent of @p dev.
3415  */
3416 int
3417 bus_generic_child_present(device_t dev, device_t child)
3418 {
3419 	return (BUS_CHILD_PRESENT(device_get_parent(dev), dev));
3420 }
3421 
3422 /*
3423  * Some convenience functions to make it easier for drivers to use the
3424  * resource-management functions.  All these really do is hide the
3425  * indirection through the parent's method table, making for slightly
3426  * less-wordy code.  In the future, it might make sense for this code
3427  * to maintain some sort of a list of resources allocated by each device.
3428  */
3429 
3430 int
3431 bus_alloc_resources(device_t dev, struct resource_spec *rs,
3432     struct resource **res)
3433 {
3434 	int i;
3435 
3436 	for (i = 0; rs[i].type != -1; i++)
3437 		res[i] = NULL;
3438 	for (i = 0; rs[i].type != -1; i++) {
3439 		res[i] = bus_alloc_resource_any(dev,
3440 		    rs[i].type, &rs[i].rid, rs[i].flags);
3441 		if (res[i] == NULL && !(rs[i].flags & RF_OPTIONAL)) {
3442 			bus_release_resources(dev, rs, res);
3443 			return (ENXIO);
3444 		}
3445 	}
3446 	return (0);
3447 }
3448 
3449 void
3450 bus_release_resources(device_t dev, const struct resource_spec *rs,
3451     struct resource **res)
3452 {
3453 	int i;
3454 
3455 	for (i = 0; rs[i].type != -1; i++)
3456 		if (res[i] != NULL) {
3457 			bus_release_resource(
3458 			    dev, rs[i].type, rs[i].rid, res[i]);
3459 			res[i] = NULL;
3460 		}
3461 }
3462 
3463 /**
3464  * @brief Wrapper function for BUS_ALLOC_RESOURCE().
3465  *
3466  * This function simply calls the BUS_ALLOC_RESOURCE() method of the
3467  * parent of @p dev.
3468  */
3469 struct resource *
3470 bus_alloc_resource(device_t dev, int type, int *rid, u_long start, u_long end,
3471     u_long count, u_int flags)
3472 {
3473 	if (dev->parent == NULL)
3474 		return (NULL);
3475 	return (BUS_ALLOC_RESOURCE(dev->parent, dev, type, rid, start, end,
3476 	    count, flags));
3477 }
3478 
3479 /**
3480  * @brief Wrapper function for BUS_ACTIVATE_RESOURCE().
3481  *
3482  * This function simply calls the BUS_ACTIVATE_RESOURCE() method of the
3483  * parent of @p dev.
3484  */
3485 int
3486 bus_activate_resource(device_t dev, int type, int rid, struct resource *r)
3487 {
3488 	if (dev->parent == NULL)
3489 		return (EINVAL);
3490 	return (BUS_ACTIVATE_RESOURCE(dev->parent, dev, type, rid, r));
3491 }
3492 
3493 /**
3494  * @brief Wrapper function for BUS_DEACTIVATE_RESOURCE().
3495  *
3496  * This function simply calls the BUS_DEACTIVATE_RESOURCE() method of the
3497  * parent of @p dev.
3498  */
3499 int
3500 bus_deactivate_resource(device_t dev, int type, int rid, struct resource *r)
3501 {
3502 	if (dev->parent == NULL)
3503 		return (EINVAL);
3504 	return (BUS_DEACTIVATE_RESOURCE(dev->parent, dev, type, rid, r));
3505 }
3506 
3507 /**
3508  * @brief Wrapper function for BUS_RELEASE_RESOURCE().
3509  *
3510  * This function simply calls the BUS_RELEASE_RESOURCE() method of the
3511  * parent of @p dev.
3512  */
3513 int
3514 bus_release_resource(device_t dev, int type, int rid, struct resource *r)
3515 {
3516 	if (dev->parent == NULL)
3517 		return (EINVAL);
3518 	return (BUS_RELEASE_RESOURCE(dev->parent, dev, type, rid, r));
3519 }
3520 
3521 /**
3522  * @brief Wrapper function for BUS_SETUP_INTR().
3523  *
3524  * This function simply calls the BUS_SETUP_INTR() method of the
3525  * parent of @p dev.
3526  */
3527 int
3528 bus_setup_intr(device_t dev, struct resource *r, int flags,
3529     driver_filter_t filter, driver_intr_t handler, void *arg, void **cookiep)
3530 {
3531 	int error;
3532 
3533 	if (dev->parent == NULL)
3534 		return (EINVAL);
3535 	error = BUS_SETUP_INTR(dev->parent, dev, r, flags, filter, handler,
3536 	    arg, cookiep);
3537 	if (error != 0)
3538 		return (error);
3539 	if (handler != NULL && !(flags & INTR_MPSAFE))
3540 		device_printf(dev, "[GIANT-LOCKED]\n");
3541 	if (bootverbose && (flags & INTR_MPSAFE))
3542 		device_printf(dev, "[MPSAFE]\n");
3543 	if (filter != NULL) {
3544 		if (handler == NULL)
3545 			device_printf(dev, "[FILTER]\n");
3546 		else
3547 			device_printf(dev, "[FILTER+ITHREAD]\n");
3548 	} else
3549 		device_printf(dev, "[ITHREAD]\n");
3550 	return (0);
3551 }
3552 
3553 /**
3554  * @brief Wrapper function for BUS_TEARDOWN_INTR().
3555  *
3556  * This function simply calls the BUS_TEARDOWN_INTR() method of the
3557  * parent of @p dev.
3558  */
3559 int
3560 bus_teardown_intr(device_t dev, struct resource *r, void *cookie)
3561 {
3562 	if (dev->parent == NULL)
3563 		return (EINVAL);
3564 	return (BUS_TEARDOWN_INTR(dev->parent, dev, r, cookie));
3565 }
3566 
3567 /**
3568  * @brief Wrapper function for BUS_BIND_INTR().
3569  *
3570  * This function simply calls the BUS_BIND_INTR() method of the
3571  * parent of @p dev.
3572  */
3573 int
3574 bus_bind_intr(device_t dev, struct resource *r, int cpu)
3575 {
3576 	if (dev->parent == NULL)
3577 		return (EINVAL);
3578 	return (BUS_BIND_INTR(dev->parent, dev, r, cpu));
3579 }
3580 
3581 /**
3582  * @brief Wrapper function for BUS_SET_RESOURCE().
3583  *
3584  * This function simply calls the BUS_SET_RESOURCE() method of the
3585  * parent of @p dev.
3586  */
3587 int
3588 bus_set_resource(device_t dev, int type, int rid,
3589     u_long start, u_long count)
3590 {
3591 	return (BUS_SET_RESOURCE(device_get_parent(dev), dev, type, rid,
3592 	    start, count));
3593 }
3594 
3595 /**
3596  * @brief Wrapper function for BUS_GET_RESOURCE().
3597  *
3598  * This function simply calls the BUS_GET_RESOURCE() method of the
3599  * parent of @p dev.
3600  */
3601 int
3602 bus_get_resource(device_t dev, int type, int rid,
3603     u_long *startp, u_long *countp)
3604 {
3605 	return (BUS_GET_RESOURCE(device_get_parent(dev), dev, type, rid,
3606 	    startp, countp));
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 start value.
3614  */
3615 u_long
3616 bus_get_resource_start(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 (start);
3626 }
3627 
3628 /**
3629  * @brief Wrapper function for BUS_GET_RESOURCE().
3630  *
3631  * This function simply calls the BUS_GET_RESOURCE() method of the
3632  * parent of @p dev and returns the count value.
3633  */
3634 u_long
3635 bus_get_resource_count(device_t dev, int type, int rid)
3636 {
3637 	u_long start, count;
3638 	int error;
3639 
3640 	error = BUS_GET_RESOURCE(device_get_parent(dev), dev, type, rid,
3641 	    &start, &count);
3642 	if (error)
3643 		return (0);
3644 	return (count);
3645 }
3646 
3647 /**
3648  * @brief Wrapper function for BUS_DELETE_RESOURCE().
3649  *
3650  * This function simply calls the BUS_DELETE_RESOURCE() method of the
3651  * parent of @p dev.
3652  */
3653 void
3654 bus_delete_resource(device_t dev, int type, int rid)
3655 {
3656 	BUS_DELETE_RESOURCE(device_get_parent(dev), dev, type, rid);
3657 }
3658 
3659 /**
3660  * @brief Wrapper function for BUS_CHILD_PRESENT().
3661  *
3662  * This function simply calls the BUS_CHILD_PRESENT() method of the
3663  * parent of @p dev.
3664  */
3665 int
3666 bus_child_present(device_t child)
3667 {
3668 	return (BUS_CHILD_PRESENT(device_get_parent(child), child));
3669 }
3670 
3671 /**
3672  * @brief Wrapper function for BUS_CHILD_PNPINFO_STR().
3673  *
3674  * This function simply calls the BUS_CHILD_PNPINFO_STR() method of the
3675  * parent of @p dev.
3676  */
3677 int
3678 bus_child_pnpinfo_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_PNPINFO_STR(parent, child, buf, buflen));
3688 }
3689 
3690 /**
3691  * @brief Wrapper function for BUS_CHILD_LOCATION_STR().
3692  *
3693  * This function simply calls the BUS_CHILD_LOCATION_STR() method of the
3694  * parent of @p dev.
3695  */
3696 int
3697 bus_child_location_str(device_t child, char *buf, size_t buflen)
3698 {
3699 	device_t parent;
3700 
3701 	parent = device_get_parent(child);
3702 	if (parent == NULL) {
3703 		*buf = '\0';
3704 		return (0);
3705 	}
3706 	return (BUS_CHILD_LOCATION_STR(parent, child, buf, buflen));
3707 }
3708 
3709 /**
3710  * @brief Wrapper function for BUS_GET_DMA_TAG().
3711  *
3712  * This function simply calls the BUS_GET_DMA_TAG() method of the
3713  * parent of @p dev.
3714  */
3715 bus_dma_tag_t
3716 bus_get_dma_tag(device_t dev)
3717 {
3718 	device_t parent;
3719 
3720 	parent = device_get_parent(dev);
3721 	if (parent == NULL)
3722 		return (NULL);
3723 	return (BUS_GET_DMA_TAG(parent, dev));
3724 }
3725 
3726 /* Resume all devices and then notify userland that we're up again. */
3727 static int
3728 root_resume(device_t dev)
3729 {
3730 	int error;
3731 
3732 	error = bus_generic_resume(dev);
3733 	if (error == 0)
3734 		devctl_notify("kern", "power", "resume", NULL);
3735 	return (error);
3736 }
3737 
3738 static int
3739 root_print_child(device_t dev, device_t child)
3740 {
3741 	int	retval = 0;
3742 
3743 	retval += bus_print_child_header(dev, child);
3744 	retval += printf("\n");
3745 
3746 	return (retval);
3747 }
3748 
3749 static int
3750 root_setup_intr(device_t dev, device_t child, driver_intr_t *intr, void *arg,
3751     void **cookiep)
3752 {
3753 	/*
3754 	 * If an interrupt mapping gets to here something bad has happened.
3755 	 */
3756 	panic("root_setup_intr");
3757 }
3758 
3759 /*
3760  * If we get here, assume that the device is permanant and really is
3761  * present in the system.  Removable bus drivers are expected to intercept
3762  * this call long before it gets here.  We return -1 so that drivers that
3763  * really care can check vs -1 or some ERRNO returned higher in the food
3764  * chain.
3765  */
3766 static int
3767 root_child_present(device_t dev, device_t child)
3768 {
3769 	return (-1);
3770 }
3771 
3772 static kobj_method_t root_methods[] = {
3773 	/* Device interface */
3774 	KOBJMETHOD(device_shutdown,	bus_generic_shutdown),
3775 	KOBJMETHOD(device_suspend,	bus_generic_suspend),
3776 	KOBJMETHOD(device_resume,	root_resume),
3777 
3778 	/* Bus interface */
3779 	KOBJMETHOD(bus_print_child,	root_print_child),
3780 	KOBJMETHOD(bus_read_ivar,	bus_generic_read_ivar),
3781 	KOBJMETHOD(bus_write_ivar,	bus_generic_write_ivar),
3782 	KOBJMETHOD(bus_setup_intr,	root_setup_intr),
3783 	KOBJMETHOD(bus_child_present,	root_child_present),
3784 
3785 	{ 0, 0 }
3786 };
3787 
3788 static driver_t root_driver = {
3789 	"root",
3790 	root_methods,
3791 	1,			/* no softc */
3792 };
3793 
3794 device_t	root_bus;
3795 devclass_t	root_devclass;
3796 
3797 static int
3798 root_bus_module_handler(module_t mod, int what, void* arg)
3799 {
3800 	switch (what) {
3801 	case MOD_LOAD:
3802 		TAILQ_INIT(&bus_data_devices);
3803 		kobj_class_compile((kobj_class_t) &root_driver);
3804 		root_bus = make_device(NULL, "root", 0);
3805 		root_bus->desc = "System root bus";
3806 		kobj_init((kobj_t) root_bus, (kobj_class_t) &root_driver);
3807 		root_bus->driver = &root_driver;
3808 		root_bus->state = DS_ATTACHED;
3809 		root_devclass = devclass_find_internal("root", NULL, FALSE);
3810 		devinit();
3811 		return (0);
3812 
3813 	case MOD_SHUTDOWN:
3814 		device_shutdown(root_bus);
3815 		return (0);
3816 	default:
3817 		return (EOPNOTSUPP);
3818 	}
3819 
3820 	return (0);
3821 }
3822 
3823 static moduledata_t root_bus_mod = {
3824 	"rootbus",
3825 	root_bus_module_handler,
3826 	0
3827 };
3828 DECLARE_MODULE(rootbus, root_bus_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
3829 
3830 /**
3831  * @brief Automatically configure devices
3832  *
3833  * This function begins the autoconfiguration process by calling
3834  * device_probe_and_attach() for each child of the @c root0 device.
3835  */
3836 void
3837 root_bus_configure(void)
3838 {
3839 	device_t dev;
3840 
3841 	PDEBUG(("."));
3842 
3843 	TAILQ_FOREACH(dev, &root_bus->children, link) {
3844 		device_probe_and_attach(dev);
3845 	}
3846 }
3847 
3848 /**
3849  * @brief Module handler for registering device drivers
3850  *
3851  * This module handler is used to automatically register device
3852  * drivers when modules are loaded. If @p what is MOD_LOAD, it calls
3853  * devclass_add_driver() for the driver described by the
3854  * driver_module_data structure pointed to by @p arg
3855  */
3856 int
3857 driver_module_handler(module_t mod, int what, void *arg)
3858 {
3859 	int error;
3860 	struct driver_module_data *dmd;
3861 	devclass_t bus_devclass;
3862 	kobj_class_t driver;
3863 
3864 	dmd = (struct driver_module_data *)arg;
3865 	bus_devclass = devclass_find_internal(dmd->dmd_busname, NULL, TRUE);
3866 	error = 0;
3867 
3868 	switch (what) {
3869 	case MOD_LOAD:
3870 		if (dmd->dmd_chainevh)
3871 			error = dmd->dmd_chainevh(mod,what,dmd->dmd_chainarg);
3872 
3873 		driver = dmd->dmd_driver;
3874 		PDEBUG(("Loading module: driver %s on bus %s",
3875 		    DRIVERNAME(driver), dmd->dmd_busname));
3876 		error = devclass_add_driver(bus_devclass, driver);
3877 		if (error)
3878 			break;
3879 
3880 		/*
3881 		 * If the driver has any base classes, make the
3882 		 * devclass inherit from the devclass of the driver's
3883 		 * first base class. This will allow the system to
3884 		 * search for drivers in both devclasses for children
3885 		 * of a device using this driver.
3886 		 */
3887 		if (driver->baseclasses) {
3888 			const char *parentname;
3889 			parentname = driver->baseclasses[0]->name;
3890 			*dmd->dmd_devclass =
3891 				devclass_find_internal(driver->name,
3892 				    parentname, TRUE);
3893 		} else {
3894 			*dmd->dmd_devclass =
3895 				devclass_find_internal(driver->name, NULL, TRUE);
3896 		}
3897 		break;
3898 
3899 	case MOD_UNLOAD:
3900 		PDEBUG(("Unloading module: driver %s from bus %s",
3901 		    DRIVERNAME(dmd->dmd_driver),
3902 		    dmd->dmd_busname));
3903 		error = devclass_delete_driver(bus_devclass,
3904 		    dmd->dmd_driver);
3905 
3906 		if (!error && dmd->dmd_chainevh)
3907 			error = dmd->dmd_chainevh(mod,what,dmd->dmd_chainarg);
3908 		break;
3909 	case MOD_QUIESCE:
3910 		PDEBUG(("Quiesce module: driver %s from bus %s",
3911 		    DRIVERNAME(dmd->dmd_driver),
3912 		    dmd->dmd_busname));
3913 		error = devclass_quiesce_driver(bus_devclass,
3914 		    dmd->dmd_driver);
3915 
3916 		if (!error && dmd->dmd_chainevh)
3917 			error = dmd->dmd_chainevh(mod,what,dmd->dmd_chainarg);
3918 		break;
3919 	default:
3920 		error = EOPNOTSUPP;
3921 		break;
3922 	}
3923 
3924 	return (error);
3925 }
3926 
3927 /**
3928  * @brief Enumerate all hinted devices for this bus.
3929  *
3930  * Walks through the hints for this bus and calls the bus_hinted_child
3931  * routine for each one it fines.  It searches first for the specific
3932  * bus that's being probed for hinted children (eg isa0), and then for
3933  * generic children (eg isa).
3934  *
3935  * @param	dev	bus device to enumerate
3936  */
3937 void
3938 bus_enumerate_hinted_children(device_t bus)
3939 {
3940 	int i;
3941 	const char *dname, *busname;
3942 	int dunit;
3943 
3944 	/*
3945 	 * enumerate all devices on the specific bus
3946 	 */
3947 	busname = device_get_nameunit(bus);
3948 	i = 0;
3949 	while (resource_find_match(&i, &dname, &dunit, "at", busname) == 0)
3950 		BUS_HINTED_CHILD(bus, dname, dunit);
3951 
3952 	/*
3953 	 * and all the generic ones.
3954 	 */
3955 	busname = device_get_name(bus);
3956 	i = 0;
3957 	while (resource_find_match(&i, &dname, &dunit, "at", busname) == 0)
3958 		BUS_HINTED_CHILD(bus, dname, dunit);
3959 }
3960 
3961 #ifdef BUS_DEBUG
3962 
3963 /* the _short versions avoid iteration by not calling anything that prints
3964  * more than oneliners. I love oneliners.
3965  */
3966 
3967 static void
3968 print_device_short(device_t dev, int indent)
3969 {
3970 	if (!dev)
3971 		return;
3972 
3973 	indentprintf(("device %d: <%s> %sparent,%schildren,%s%s%s%s%s,%sivars,%ssoftc,busy=%d\n",
3974 	    dev->unit, dev->desc,
3975 	    (dev->parent? "":"no "),
3976 	    (TAILQ_EMPTY(&dev->children)? "no ":""),
3977 	    (dev->flags&DF_ENABLED? "enabled,":"disabled,"),
3978 	    (dev->flags&DF_FIXEDCLASS? "fixed,":""),
3979 	    (dev->flags&DF_WILDCARD? "wildcard,":""),
3980 	    (dev->flags&DF_DESCMALLOCED? "descmalloced,":""),
3981 	    (dev->flags&DF_REBID? "rebiddable,":""),
3982 	    (dev->ivars? "":"no "),
3983 	    (dev->softc? "":"no "),
3984 	    dev->busy));
3985 }
3986 
3987 static void
3988 print_device(device_t dev, int indent)
3989 {
3990 	if (!dev)
3991 		return;
3992 
3993 	print_device_short(dev, indent);
3994 
3995 	indentprintf(("Parent:\n"));
3996 	print_device_short(dev->parent, indent+1);
3997 	indentprintf(("Driver:\n"));
3998 	print_driver_short(dev->driver, indent+1);
3999 	indentprintf(("Devclass:\n"));
4000 	print_devclass_short(dev->devclass, indent+1);
4001 }
4002 
4003 void
4004 print_device_tree_short(device_t dev, int indent)
4005 /* print the device and all its children (indented) */
4006 {
4007 	device_t child;
4008 
4009 	if (!dev)
4010 		return;
4011 
4012 	print_device_short(dev, indent);
4013 
4014 	TAILQ_FOREACH(child, &dev->children, link) {
4015 		print_device_tree_short(child, indent+1);
4016 	}
4017 }
4018 
4019 void
4020 print_device_tree(device_t dev, int indent)
4021 /* print the device and all its children (indented) */
4022 {
4023 	device_t child;
4024 
4025 	if (!dev)
4026 		return;
4027 
4028 	print_device(dev, indent);
4029 
4030 	TAILQ_FOREACH(child, &dev->children, link) {
4031 		print_device_tree(child, indent+1);
4032 	}
4033 }
4034 
4035 static void
4036 print_driver_short(driver_t *driver, int indent)
4037 {
4038 	if (!driver)
4039 		return;
4040 
4041 	indentprintf(("driver %s: softc size = %zd\n",
4042 	    driver->name, driver->size));
4043 }
4044 
4045 static void
4046 print_driver(driver_t *driver, int indent)
4047 {
4048 	if (!driver)
4049 		return;
4050 
4051 	print_driver_short(driver, indent);
4052 }
4053 
4054 
4055 static void
4056 print_driver_list(driver_list_t drivers, int indent)
4057 {
4058 	driverlink_t driver;
4059 
4060 	TAILQ_FOREACH(driver, &drivers, link) {
4061 		print_driver(driver->driver, indent);
4062 	}
4063 }
4064 
4065 static void
4066 print_devclass_short(devclass_t dc, int indent)
4067 {
4068 	if ( !dc )
4069 		return;
4070 
4071 	indentprintf(("devclass %s: max units = %d\n", dc->name, dc->maxunit));
4072 }
4073 
4074 static void
4075 print_devclass(devclass_t dc, int indent)
4076 {
4077 	int i;
4078 
4079 	if ( !dc )
4080 		return;
4081 
4082 	print_devclass_short(dc, indent);
4083 	indentprintf(("Drivers:\n"));
4084 	print_driver_list(dc->drivers, indent+1);
4085 
4086 	indentprintf(("Devices:\n"));
4087 	for (i = 0; i < dc->maxunit; i++)
4088 		if (dc->devices[i])
4089 			print_device(dc->devices[i], indent+1);
4090 }
4091 
4092 void
4093 print_devclass_list_short(void)
4094 {
4095 	devclass_t dc;
4096 
4097 	printf("Short listing of devclasses, drivers & devices:\n");
4098 	TAILQ_FOREACH(dc, &devclasses, link) {
4099 		print_devclass_short(dc, 0);
4100 	}
4101 }
4102 
4103 void
4104 print_devclass_list(void)
4105 {
4106 	devclass_t dc;
4107 
4108 	printf("Full listing of devclasses, drivers & devices:\n");
4109 	TAILQ_FOREACH(dc, &devclasses, link) {
4110 		print_devclass(dc, 0);
4111 	}
4112 }
4113 
4114 #endif
4115 
4116 /*
4117  * User-space access to the device tree.
4118  *
4119  * We implement a small set of nodes:
4120  *
4121  * hw.bus			Single integer read method to obtain the
4122  *				current generation count.
4123  * hw.bus.devices		Reads the entire device tree in flat space.
4124  * hw.bus.rman			Resource manager interface
4125  *
4126  * We might like to add the ability to scan devclasses and/or drivers to
4127  * determine what else is currently loaded/available.
4128  */
4129 
4130 static int
4131 sysctl_bus(SYSCTL_HANDLER_ARGS)
4132 {
4133 	struct u_businfo	ubus;
4134 
4135 	ubus.ub_version = BUS_USER_VERSION;
4136 	ubus.ub_generation = bus_data_generation;
4137 
4138 	return (SYSCTL_OUT(req, &ubus, sizeof(ubus)));
4139 }
4140 SYSCTL_NODE(_hw_bus, OID_AUTO, info, CTLFLAG_RW, sysctl_bus,
4141     "bus-related data");
4142 
4143 static int
4144 sysctl_devices(SYSCTL_HANDLER_ARGS)
4145 {
4146 	int			*name = (int *)arg1;
4147 	u_int			namelen = arg2;
4148 	int			index;
4149 	struct device		*dev;
4150 	struct u_device		udev;	/* XXX this is a bit big */
4151 	int			error;
4152 
4153 	if (namelen != 2)
4154 		return (EINVAL);
4155 
4156 	if (bus_data_generation_check(name[0]))
4157 		return (EINVAL);
4158 
4159 	index = name[1];
4160 
4161 	/*
4162 	 * Scan the list of devices, looking for the requested index.
4163 	 */
4164 	TAILQ_FOREACH(dev, &bus_data_devices, devlink) {
4165 		if (index-- == 0)
4166 			break;
4167 	}
4168 	if (dev == NULL)
4169 		return (ENOENT);
4170 
4171 	/*
4172 	 * Populate the return array.
4173 	 */
4174 	bzero(&udev, sizeof(udev));
4175 	udev.dv_handle = (uintptr_t)dev;
4176 	udev.dv_parent = (uintptr_t)dev->parent;
4177 	if (dev->nameunit != NULL)
4178 		strlcpy(udev.dv_name, dev->nameunit, sizeof(udev.dv_name));
4179 	if (dev->desc != NULL)
4180 		strlcpy(udev.dv_desc, dev->desc, sizeof(udev.dv_desc));
4181 	if (dev->driver != NULL && dev->driver->name != NULL)
4182 		strlcpy(udev.dv_drivername, dev->driver->name,
4183 		    sizeof(udev.dv_drivername));
4184 	bus_child_pnpinfo_str(dev, udev.dv_pnpinfo, sizeof(udev.dv_pnpinfo));
4185 	bus_child_location_str(dev, udev.dv_location, sizeof(udev.dv_location));
4186 	udev.dv_devflags = dev->devflags;
4187 	udev.dv_flags = dev->flags;
4188 	udev.dv_state = dev->state;
4189 	error = SYSCTL_OUT(req, &udev, sizeof(udev));
4190 	return (error);
4191 }
4192 
4193 SYSCTL_NODE(_hw_bus, OID_AUTO, devices, CTLFLAG_RD, sysctl_devices,
4194     "system device tree");
4195 
4196 int
4197 bus_data_generation_check(int generation)
4198 {
4199 	if (generation != bus_data_generation)
4200 		return (1);
4201 
4202 	/* XXX generate optimised lists here? */
4203 	return (0);
4204 }
4205 
4206 void
4207 bus_data_generation_update(void)
4208 {
4209 	bus_data_generation++;
4210 }
4211 
4212 int
4213 bus_free_resource(device_t dev, int type, struct resource *r)
4214 {
4215 	if (r == NULL)
4216 		return (0);
4217 	return (bus_release_resource(dev, type, rman_get_rid(r), r));
4218 }
4219