xref: /freebsd/sys/kern/subr_bus.c (revision 77013d11e6483b970af25e13c9b892075742f7e5)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 1997,1998,2003 Doug Rabson
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include "opt_bus.h"
33 #include "opt_ddb.h"
34 
35 #include <sys/param.h>
36 #include <sys/conf.h>
37 #include <sys/domainset.h>
38 #include <sys/eventhandler.h>
39 #include <sys/filio.h>
40 #include <sys/lock.h>
41 #include <sys/kernel.h>
42 #include <sys/kobj.h>
43 #include <sys/limits.h>
44 #include <sys/malloc.h>
45 #include <sys/module.h>
46 #include <sys/mutex.h>
47 #include <sys/poll.h>
48 #include <sys/priv.h>
49 #include <sys/proc.h>
50 #include <sys/condvar.h>
51 #include <sys/queue.h>
52 #include <machine/bus.h>
53 #include <sys/random.h>
54 #include <sys/rman.h>
55 #include <sys/sbuf.h>
56 #include <sys/selinfo.h>
57 #include <sys/signalvar.h>
58 #include <sys/smp.h>
59 #include <sys/sysctl.h>
60 #include <sys/systm.h>
61 #include <sys/uio.h>
62 #include <sys/bus.h>
63 #include <sys/cpuset.h>
64 
65 #include <net/vnet.h>
66 
67 #include <machine/cpu.h>
68 #include <machine/stdarg.h>
69 
70 #include <vm/uma.h>
71 #include <vm/vm.h>
72 
73 #include <ddb/ddb.h>
74 
75 SYSCTL_NODE(_hw, OID_AUTO, bus, CTLFLAG_RW | CTLFLAG_MPSAFE, NULL,
76     NULL);
77 SYSCTL_ROOT_NODE(OID_AUTO, dev, CTLFLAG_RW | CTLFLAG_MPSAFE, NULL,
78     NULL);
79 
80 /*
81  * Used to attach drivers to devclasses.
82  */
83 typedef struct driverlink *driverlink_t;
84 struct driverlink {
85 	kobj_class_t	driver;
86 	TAILQ_ENTRY(driverlink) link;	/* list of drivers in devclass */
87 	int		pass;
88 	int		flags;
89 #define DL_DEFERRED_PROBE	1	/* Probe deferred on this */
90 	TAILQ_ENTRY(driverlink) passlink;
91 };
92 
93 /*
94  * Forward declarations
95  */
96 typedef TAILQ_HEAD(devclass_list, devclass) devclass_list_t;
97 typedef TAILQ_HEAD(driver_list, driverlink) driver_list_t;
98 typedef TAILQ_HEAD(device_list, _device) device_list_t;
99 
100 struct devclass {
101 	TAILQ_ENTRY(devclass) link;
102 	devclass_t	parent;		/* parent in devclass hierarchy */
103 	driver_list_t	drivers;	/* bus devclasses store drivers for bus */
104 	char		*name;
105 	device_t	*devices;	/* array of devices indexed by unit */
106 	int		maxunit;	/* size of devices array */
107 	int		flags;
108 #define DC_HAS_CHILDREN		1
109 
110 	struct sysctl_ctx_list sysctl_ctx;
111 	struct sysctl_oid *sysctl_tree;
112 };
113 
114 /**
115  * @brief Implementation of _device.
116  *
117  * The structure is named "_device" instead of "device" to avoid type confusion
118  * caused by other subsystems defining a (struct device).
119  */
120 struct _device {
121 	/*
122 	 * A device is a kernel object. The first field must be the
123 	 * current ops table for the object.
124 	 */
125 	KOBJ_FIELDS;
126 
127 	/*
128 	 * Device hierarchy.
129 	 */
130 	TAILQ_ENTRY(_device)	link;	/**< list of devices in parent */
131 	TAILQ_ENTRY(_device)	devlink; /**< global device list membership */
132 	device_t	parent;		/**< parent of this device  */
133 	device_list_t	children;	/**< list of child devices */
134 
135 	/*
136 	 * Details of this device.
137 	 */
138 	driver_t	*driver;	/**< current driver */
139 	devclass_t	devclass;	/**< current device class */
140 	int		unit;		/**< current unit number */
141 	char*		nameunit;	/**< name+unit e.g. foodev0 */
142 	char*		desc;		/**< driver specific description */
143 	int		busy;		/**< count of calls to device_busy() */
144 	device_state_t	state;		/**< current device state  */
145 	uint32_t	devflags;	/**< api level flags for device_get_flags() */
146 	u_int		flags;		/**< internal device flags  */
147 	u_int	order;			/**< order from device_add_child_ordered() */
148 	void	*ivars;			/**< instance variables  */
149 	void	*softc;			/**< current driver's variables  */
150 
151 	struct sysctl_ctx_list sysctl_ctx; /**< state for sysctl variables  */
152 	struct sysctl_oid *sysctl_tree;	/**< state for sysctl variables */
153 };
154 
155 static MALLOC_DEFINE(M_BUS, "bus", "Bus data structures");
156 static MALLOC_DEFINE(M_BUS_SC, "bus-sc", "Bus data structures, softc");
157 
158 EVENTHANDLER_LIST_DEFINE(device_attach);
159 EVENTHANDLER_LIST_DEFINE(device_detach);
160 EVENTHANDLER_LIST_DEFINE(dev_lookup);
161 
162 static void devctl2_init(void);
163 static bool device_frozen;
164 
165 #define DRIVERNAME(d)	((d)? d->name : "no driver")
166 #define DEVCLANAME(d)	((d)? d->name : "no devclass")
167 
168 #ifdef BUS_DEBUG
169 
170 static int bus_debug = 1;
171 SYSCTL_INT(_debug, OID_AUTO, bus_debug, CTLFLAG_RWTUN, &bus_debug, 0,
172     "Bus debug level");
173 #define PDEBUG(a)	if (bus_debug) {printf("%s:%d: ", __func__, __LINE__), printf a; printf("\n");}
174 #define DEVICENAME(d)	((d)? device_get_name(d): "no device")
175 
176 /**
177  * Produce the indenting, indent*2 spaces plus a '.' ahead of that to
178  * prevent syslog from deleting initial spaces
179  */
180 #define indentprintf(p)	do { int iJ; printf("."); for (iJ=0; iJ<indent; iJ++) printf("  "); printf p ; } while (0)
181 
182 static void print_device_short(device_t dev, int indent);
183 static void print_device(device_t dev, int indent);
184 void print_device_tree_short(device_t dev, int indent);
185 void print_device_tree(device_t dev, int indent);
186 static void print_driver_short(driver_t *driver, int indent);
187 static void print_driver(driver_t *driver, int indent);
188 static void print_driver_list(driver_list_t drivers, int indent);
189 static void print_devclass_short(devclass_t dc, int indent);
190 static void print_devclass(devclass_t dc, int indent);
191 void print_devclass_list_short(void);
192 void print_devclass_list(void);
193 
194 #else
195 /* Make the compiler ignore the function calls */
196 #define PDEBUG(a)			/* nop */
197 #define DEVICENAME(d)			/* nop */
198 
199 #define print_device_short(d,i)		/* nop */
200 #define print_device(d,i)		/* nop */
201 #define print_device_tree_short(d,i)	/* nop */
202 #define print_device_tree(d,i)		/* nop */
203 #define print_driver_short(d,i)		/* nop */
204 #define print_driver(d,i)		/* nop */
205 #define print_driver_list(d,i)		/* nop */
206 #define print_devclass_short(d,i)	/* nop */
207 #define print_devclass(d,i)		/* nop */
208 #define print_devclass_list_short()	/* nop */
209 #define print_devclass_list()		/* nop */
210 #endif
211 
212 /*
213  * dev sysctl tree
214  */
215 
216 enum {
217 	DEVCLASS_SYSCTL_PARENT,
218 };
219 
220 static int
221 devclass_sysctl_handler(SYSCTL_HANDLER_ARGS)
222 {
223 	devclass_t dc = (devclass_t)arg1;
224 	const char *value;
225 
226 	switch (arg2) {
227 	case DEVCLASS_SYSCTL_PARENT:
228 		value = dc->parent ? dc->parent->name : "";
229 		break;
230 	default:
231 		return (EINVAL);
232 	}
233 	return (SYSCTL_OUT_STR(req, value));
234 }
235 
236 static void
237 devclass_sysctl_init(devclass_t dc)
238 {
239 	if (dc->sysctl_tree != NULL)
240 		return;
241 	sysctl_ctx_init(&dc->sysctl_ctx);
242 	dc->sysctl_tree = SYSCTL_ADD_NODE(&dc->sysctl_ctx,
243 	    SYSCTL_STATIC_CHILDREN(_dev), OID_AUTO, dc->name,
244 	    CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "");
245 	SYSCTL_ADD_PROC(&dc->sysctl_ctx, SYSCTL_CHILDREN(dc->sysctl_tree),
246 	    OID_AUTO, "%parent",
247 	    CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT,
248 	    dc, DEVCLASS_SYSCTL_PARENT, devclass_sysctl_handler, "A",
249 	    "parent class");
250 }
251 
252 enum {
253 	DEVICE_SYSCTL_DESC,
254 	DEVICE_SYSCTL_DRIVER,
255 	DEVICE_SYSCTL_LOCATION,
256 	DEVICE_SYSCTL_PNPINFO,
257 	DEVICE_SYSCTL_PARENT,
258 };
259 
260 static int
261 device_sysctl_handler(SYSCTL_HANDLER_ARGS)
262 {
263 	struct sbuf sb;
264 	device_t dev = (device_t)arg1;
265 	int error;
266 
267 	sbuf_new_for_sysctl(&sb, NULL, 1024, req);
268 	sbuf_clear_flags(&sb, SBUF_INCLUDENUL);
269 	switch (arg2) {
270 	case DEVICE_SYSCTL_DESC:
271 		sbuf_cat(&sb, dev->desc ? dev->desc : "");
272 		break;
273 	case DEVICE_SYSCTL_DRIVER:
274 		sbuf_cat(&sb, dev->driver ? dev->driver->name : "");
275 		break;
276 	case DEVICE_SYSCTL_LOCATION:
277 		bus_child_location(dev, &sb);
278 		break;
279 	case DEVICE_SYSCTL_PNPINFO:
280 		bus_child_pnpinfo(dev, &sb);
281 		break;
282 	case DEVICE_SYSCTL_PARENT:
283 		sbuf_cat(&sb, dev->parent ? dev->parent->nameunit : "");
284 		break;
285 	default:
286 		sbuf_delete(&sb);
287 		return (EINVAL);
288 	}
289 	error = sbuf_finish(&sb);
290 	sbuf_delete(&sb);
291 	return (error);
292 }
293 
294 static void
295 device_sysctl_init(device_t dev)
296 {
297 	devclass_t dc = dev->devclass;
298 	int domain;
299 
300 	if (dev->sysctl_tree != NULL)
301 		return;
302 	devclass_sysctl_init(dc);
303 	sysctl_ctx_init(&dev->sysctl_ctx);
304 	dev->sysctl_tree = SYSCTL_ADD_NODE_WITH_LABEL(&dev->sysctl_ctx,
305 	    SYSCTL_CHILDREN(dc->sysctl_tree), OID_AUTO,
306 	    dev->nameunit + strlen(dc->name),
307 	    CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "", "device_index");
308 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
309 	    OID_AUTO, "%desc", CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT,
310 	    dev, DEVICE_SYSCTL_DESC, device_sysctl_handler, "A",
311 	    "device description");
312 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
313 	    OID_AUTO, "%driver",
314 	    CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT,
315 	    dev, DEVICE_SYSCTL_DRIVER, device_sysctl_handler, "A",
316 	    "device driver name");
317 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
318 	    OID_AUTO, "%location",
319 	    CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT,
320 	    dev, DEVICE_SYSCTL_LOCATION, device_sysctl_handler, "A",
321 	    "device location relative to parent");
322 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
323 	    OID_AUTO, "%pnpinfo",
324 	    CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT,
325 	    dev, DEVICE_SYSCTL_PNPINFO, device_sysctl_handler, "A",
326 	    "device identification");
327 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
328 	    OID_AUTO, "%parent",
329 	    CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT,
330 	    dev, DEVICE_SYSCTL_PARENT, device_sysctl_handler, "A",
331 	    "parent device");
332 	if (bus_get_domain(dev, &domain) == 0)
333 		SYSCTL_ADD_INT(&dev->sysctl_ctx,
334 		    SYSCTL_CHILDREN(dev->sysctl_tree), OID_AUTO, "%domain",
335 		    CTLFLAG_RD, NULL, domain, "NUMA domain");
336 }
337 
338 static void
339 device_sysctl_update(device_t dev)
340 {
341 	devclass_t dc = dev->devclass;
342 
343 	if (dev->sysctl_tree == NULL)
344 		return;
345 	sysctl_rename_oid(dev->sysctl_tree, dev->nameunit + strlen(dc->name));
346 }
347 
348 static void
349 device_sysctl_fini(device_t dev)
350 {
351 	if (dev->sysctl_tree == NULL)
352 		return;
353 	sysctl_ctx_free(&dev->sysctl_ctx);
354 	dev->sysctl_tree = NULL;
355 }
356 
357 /*
358  * /dev/devctl implementation
359  */
360 
361 /*
362  * This design allows only one reader for /dev/devctl.  This is not desirable
363  * in the long run, but will get a lot of hair out of this implementation.
364  * Maybe we should make this device a clonable device.
365  *
366  * Also note: we specifically do not attach a device to the device_t tree
367  * to avoid potential chicken and egg problems.  One could argue that all
368  * of this belongs to the root node.
369  */
370 
371 #define DEVCTL_DEFAULT_QUEUE_LEN 1000
372 static int sysctl_devctl_queue(SYSCTL_HANDLER_ARGS);
373 static int devctl_queue_length = DEVCTL_DEFAULT_QUEUE_LEN;
374 SYSCTL_PROC(_hw_bus, OID_AUTO, devctl_queue, CTLTYPE_INT | CTLFLAG_RWTUN |
375     CTLFLAG_MPSAFE, NULL, 0, sysctl_devctl_queue, "I", "devctl queue length");
376 
377 static d_open_t		devopen;
378 static d_close_t	devclose;
379 static d_read_t		devread;
380 static d_ioctl_t	devioctl;
381 static d_poll_t		devpoll;
382 static d_kqfilter_t	devkqfilter;
383 
384 static struct cdevsw dev_cdevsw = {
385 	.d_version =	D_VERSION,
386 	.d_open =	devopen,
387 	.d_close =	devclose,
388 	.d_read =	devread,
389 	.d_ioctl =	devioctl,
390 	.d_poll =	devpoll,
391 	.d_kqfilter =	devkqfilter,
392 	.d_name =	"devctl",
393 };
394 
395 #define DEVCTL_BUFFER (1024 - sizeof(void *))
396 struct dev_event_info {
397 	STAILQ_ENTRY(dev_event_info) dei_link;
398 	char dei_data[DEVCTL_BUFFER];
399 };
400 
401 STAILQ_HEAD(devq, dev_event_info);
402 
403 static struct dev_softc {
404 	int		inuse;
405 	int		nonblock;
406 	int		queued;
407 	int		async;
408 	struct mtx	mtx;
409 	struct cv	cv;
410 	struct selinfo	sel;
411 	struct devq	devq;
412 	struct sigio	*sigio;
413 	uma_zone_t	zone;
414 } devsoftc;
415 
416 static void	filt_devctl_detach(struct knote *kn);
417 static int	filt_devctl_read(struct knote *kn, long hint);
418 
419 struct filterops devctl_rfiltops = {
420 	.f_isfd = 1,
421 	.f_detach = filt_devctl_detach,
422 	.f_event = filt_devctl_read,
423 };
424 
425 static struct cdev *devctl_dev;
426 
427 static void
428 devinit(void)
429 {
430 	int reserve;
431 	uma_zone_t z;
432 
433 	devctl_dev = make_dev_credf(MAKEDEV_ETERNAL, &dev_cdevsw, 0, NULL,
434 	    UID_ROOT, GID_WHEEL, 0600, "devctl");
435 	mtx_init(&devsoftc.mtx, "dev mtx", "devd", MTX_DEF);
436 	cv_init(&devsoftc.cv, "dev cv");
437 	STAILQ_INIT(&devsoftc.devq);
438 	knlist_init_mtx(&devsoftc.sel.si_note, &devsoftc.mtx);
439 	if (devctl_queue_length > 0) {
440 		/*
441 		 * Allocate a zone for the messages. Preallocate 2% of these for
442 		 * a reserve. Allow only devctl_queue_length slabs to cap memory
443 		 * usage.  The reserve usually allows coverage of surges of
444 		 * events during memory shortages. Normally we won't have to
445 		 * re-use events from the queue, but will in extreme shortages.
446 		 */
447 		z = devsoftc.zone = uma_zcreate("DEVCTL",
448 		    sizeof(struct dev_event_info), NULL, NULL, NULL, NULL,
449 		    UMA_ALIGN_PTR, 0);
450 		reserve = max(devctl_queue_length / 50, 100);	/* 2% reserve */
451 		uma_zone_set_max(z, devctl_queue_length);
452 		uma_zone_set_maxcache(z, 0);
453 		uma_zone_reserve(z, reserve);
454 		uma_prealloc(z, reserve);
455 	}
456 	devctl2_init();
457 }
458 
459 static int
460 devopen(struct cdev *dev, int oflags, int devtype, struct thread *td)
461 {
462 	mtx_lock(&devsoftc.mtx);
463 	if (devsoftc.inuse) {
464 		mtx_unlock(&devsoftc.mtx);
465 		return (EBUSY);
466 	}
467 	/* move to init */
468 	devsoftc.inuse = 1;
469 	mtx_unlock(&devsoftc.mtx);
470 	return (0);
471 }
472 
473 static int
474 devclose(struct cdev *dev, int fflag, int devtype, struct thread *td)
475 {
476 	mtx_lock(&devsoftc.mtx);
477 	devsoftc.inuse = 0;
478 	devsoftc.nonblock = 0;
479 	devsoftc.async = 0;
480 	cv_broadcast(&devsoftc.cv);
481 	funsetown(&devsoftc.sigio);
482 	mtx_unlock(&devsoftc.mtx);
483 	return (0);
484 }
485 
486 /*
487  * The read channel for this device is used to report changes to
488  * userland in realtime.  We are required to free the data as well as
489  * the n1 object because we allocate them separately.  Also note that
490  * we return one record at a time.  If you try to read this device a
491  * character at a time, you will lose the rest of the data.  Listening
492  * programs are expected to cope.
493  */
494 static int
495 devread(struct cdev *dev, struct uio *uio, int ioflag)
496 {
497 	struct dev_event_info *n1;
498 	int rv;
499 
500 	mtx_lock(&devsoftc.mtx);
501 	while (STAILQ_EMPTY(&devsoftc.devq)) {
502 		if (devsoftc.nonblock) {
503 			mtx_unlock(&devsoftc.mtx);
504 			return (EAGAIN);
505 		}
506 		rv = cv_wait_sig(&devsoftc.cv, &devsoftc.mtx);
507 		if (rv) {
508 			/*
509 			 * Need to translate ERESTART to EINTR here? -- jake
510 			 */
511 			mtx_unlock(&devsoftc.mtx);
512 			return (rv);
513 		}
514 	}
515 	n1 = STAILQ_FIRST(&devsoftc.devq);
516 	STAILQ_REMOVE_HEAD(&devsoftc.devq, dei_link);
517 	devsoftc.queued--;
518 	mtx_unlock(&devsoftc.mtx);
519 	rv = uiomove(n1->dei_data, strlen(n1->dei_data), uio);
520 	uma_zfree(devsoftc.zone, n1);
521 	return (rv);
522 }
523 
524 static	int
525 devioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
526 {
527 	switch (cmd) {
528 	case FIONBIO:
529 		if (*(int*)data)
530 			devsoftc.nonblock = 1;
531 		else
532 			devsoftc.nonblock = 0;
533 		return (0);
534 	case FIOASYNC:
535 		if (*(int*)data)
536 			devsoftc.async = 1;
537 		else
538 			devsoftc.async = 0;
539 		return (0);
540 	case FIOSETOWN:
541 		return fsetown(*(int *)data, &devsoftc.sigio);
542 	case FIOGETOWN:
543 		*(int *)data = fgetown(&devsoftc.sigio);
544 		return (0);
545 
546 		/* (un)Support for other fcntl() calls. */
547 	case FIOCLEX:
548 	case FIONCLEX:
549 	case FIONREAD:
550 	default:
551 		break;
552 	}
553 	return (ENOTTY);
554 }
555 
556 static	int
557 devpoll(struct cdev *dev, int events, struct thread *td)
558 {
559 	int	revents = 0;
560 
561 	mtx_lock(&devsoftc.mtx);
562 	if (events & (POLLIN | POLLRDNORM)) {
563 		if (!STAILQ_EMPTY(&devsoftc.devq))
564 			revents = events & (POLLIN | POLLRDNORM);
565 		else
566 			selrecord(td, &devsoftc.sel);
567 	}
568 	mtx_unlock(&devsoftc.mtx);
569 
570 	return (revents);
571 }
572 
573 static int
574 devkqfilter(struct cdev *dev, struct knote *kn)
575 {
576 	int error;
577 
578 	if (kn->kn_filter == EVFILT_READ) {
579 		kn->kn_fop = &devctl_rfiltops;
580 		knlist_add(&devsoftc.sel.si_note, kn, 0);
581 		error = 0;
582 	} else
583 		error = EINVAL;
584 	return (error);
585 }
586 
587 static void
588 filt_devctl_detach(struct knote *kn)
589 {
590 	knlist_remove(&devsoftc.sel.si_note, kn, 0);
591 }
592 
593 static int
594 filt_devctl_read(struct knote *kn, long hint)
595 {
596 	kn->kn_data = devsoftc.queued;
597 	return (kn->kn_data != 0);
598 }
599 
600 /**
601  * @brief Return whether the userland process is running
602  */
603 bool
604 devctl_process_running(void)
605 {
606 	return (devsoftc.inuse == 1);
607 }
608 
609 static struct dev_event_info *
610 devctl_alloc_dei(void)
611 {
612 	struct dev_event_info *dei = NULL;
613 
614 	mtx_lock(&devsoftc.mtx);
615 	if (devctl_queue_length == 0)
616 		goto out;
617 	dei = uma_zalloc(devsoftc.zone, M_NOWAIT);
618 	if (dei == NULL)
619 		dei = uma_zalloc(devsoftc.zone, M_NOWAIT | M_USE_RESERVE);
620 	if (dei == NULL) {
621 		/*
622 		 * Guard against no items in the queue. Normally, this won't
623 		 * happen, but if lots of events happen all at once and there's
624 		 * a chance we're out of allocated space but none have yet been
625 		 * queued when we get here, leaving nothing to steal. This can
626 		 * also happen with error injection. Fail safe by returning
627 		 * NULL in that case..
628 		 */
629 		if (devsoftc.queued == 0)
630 			goto out;
631 		dei = STAILQ_FIRST(&devsoftc.devq);
632 		STAILQ_REMOVE_HEAD(&devsoftc.devq, dei_link);
633 		devsoftc.queued--;
634 	}
635 	MPASS(dei != NULL);
636 	*dei->dei_data = '\0';
637 out:
638 	mtx_unlock(&devsoftc.mtx);
639 	return (dei);
640 }
641 
642 static struct dev_event_info *
643 devctl_alloc_dei_sb(struct sbuf *sb)
644 {
645 	struct dev_event_info *dei;
646 
647 	dei = devctl_alloc_dei();
648 	if (dei != NULL)
649 		sbuf_new(sb, dei->dei_data, sizeof(dei->dei_data), SBUF_FIXEDLEN);
650 	return (dei);
651 }
652 
653 static void
654 devctl_free_dei(struct dev_event_info *dei)
655 {
656 	uma_zfree(devsoftc.zone, dei);
657 }
658 
659 static void
660 devctl_queue(struct dev_event_info *dei)
661 {
662 	mtx_lock(&devsoftc.mtx);
663 	STAILQ_INSERT_TAIL(&devsoftc.devq, dei, dei_link);
664 	devsoftc.queued++;
665 	cv_broadcast(&devsoftc.cv);
666 	KNOTE_LOCKED(&devsoftc.sel.si_note, 0);
667 	mtx_unlock(&devsoftc.mtx);
668 	selwakeup(&devsoftc.sel);
669 	if (devsoftc.async && devsoftc.sigio != NULL)
670 		pgsigio(&devsoftc.sigio, SIGIO, 0);
671 }
672 
673 /**
674  * @brief Send a 'notification' to userland, using standard ways
675  */
676 void
677 devctl_notify(const char *system, const char *subsystem, const char *type,
678     const char *data)
679 {
680 	struct dev_event_info *dei;
681 	struct sbuf sb;
682 
683 	if (system == NULL || subsystem == NULL || type == NULL)
684 		return;
685 	dei = devctl_alloc_dei_sb(&sb);
686 	if (dei == NULL)
687 		return;
688 	sbuf_cpy(&sb, "!system=");
689 	sbuf_cat(&sb, system);
690 	sbuf_cat(&sb, " subsystem=");
691 	sbuf_cat(&sb, subsystem);
692 	sbuf_cat(&sb, " type=");
693 	sbuf_cat(&sb, type);
694 	if (data != NULL) {
695 		sbuf_putc(&sb, ' ');
696 		sbuf_cat(&sb, data);
697 	}
698 	sbuf_putc(&sb, '\n');
699 	if (sbuf_finish(&sb) != 0)
700 		devctl_free_dei(dei);	/* overflow -> drop it */
701 	else
702 		devctl_queue(dei);
703 }
704 
705 /*
706  * Common routine that tries to make sending messages as easy as possible.
707  * We allocate memory for the data, copy strings into that, but do not
708  * free it unless there's an error.  The dequeue part of the driver should
709  * free the data.  We don't send data when the device is disabled.  We do
710  * send data, even when we have no listeners, because we wish to avoid
711  * races relating to startup and restart of listening applications.
712  *
713  * devaddq is designed to string together the type of event, with the
714  * object of that event, plus the plug and play info and location info
715  * for that event.  This is likely most useful for devices, but less
716  * useful for other consumers of this interface.  Those should use
717  * the devctl_notify() interface instead.
718  *
719  * Output:
720  *	${type}${what} at $(location dev) $(pnp-info dev) on $(parent dev)
721  */
722 static void
723 devaddq(const char *type, const char *what, device_t dev)
724 {
725 	struct dev_event_info *dei;
726 	const char *parstr;
727 	struct sbuf sb;
728 
729 	dei = devctl_alloc_dei_sb(&sb);
730 	if (dei == NULL)
731 		return;
732 	sbuf_cpy(&sb, type);
733 	sbuf_cat(&sb, what);
734 	sbuf_cat(&sb, " at ");
735 
736 	/* Add in the location */
737 	bus_child_location(dev, &sb);
738 	sbuf_putc(&sb, ' ');
739 
740 	/* Add in pnpinfo */
741 	bus_child_pnpinfo(dev, &sb);
742 
743 	/* Get the parent of this device, or / if high enough in the tree. */
744 	if (device_get_parent(dev) == NULL)
745 		parstr = ".";	/* Or '/' ? */
746 	else
747 		parstr = device_get_nameunit(device_get_parent(dev));
748 	sbuf_cat(&sb, " on ");
749 	sbuf_cat(&sb, parstr);
750 	sbuf_putc(&sb, '\n');
751 	if (sbuf_finish(&sb) != 0)
752 		goto bad;
753 	devctl_queue(dei);
754 	return;
755 bad:
756 	devctl_free_dei(dei);
757 }
758 
759 /*
760  * A device was added to the tree.  We are called just after it successfully
761  * attaches (that is, probe and attach success for this device).  No call
762  * is made if a device is merely parented into the tree.  See devnomatch
763  * if probe fails.  If attach fails, no notification is sent (but maybe
764  * we should have a different message for this).
765  */
766 static void
767 devadded(device_t dev)
768 {
769 	devaddq("+", device_get_nameunit(dev), dev);
770 }
771 
772 /*
773  * A device was removed from the tree.  We are called just before this
774  * happens.
775  */
776 static void
777 devremoved(device_t dev)
778 {
779 	devaddq("-", device_get_nameunit(dev), dev);
780 }
781 
782 /*
783  * Called when there's no match for this device.  This is only called
784  * the first time that no match happens, so we don't keep getting this
785  * message.  Should that prove to be undesirable, we can change it.
786  * This is called when all drivers that can attach to a given bus
787  * decline to accept this device.  Other errors may not be detected.
788  */
789 static void
790 devnomatch(device_t dev)
791 {
792 	devaddq("?", "", dev);
793 }
794 
795 static int
796 sysctl_devctl_queue(SYSCTL_HANDLER_ARGS)
797 {
798 	int q, error;
799 
800 	q = devctl_queue_length;
801 	error = sysctl_handle_int(oidp, &q, 0, req);
802 	if (error || !req->newptr)
803 		return (error);
804 	if (q < 0)
805 		return (EINVAL);
806 
807 	/*
808 	 * When set as a tunable, we've not yet initialized the mutex.
809 	 * It is safe to just assign to devctl_queue_length and return
810 	 * as we're racing no one. We'll use whatever value set in
811 	 * devinit.
812 	 */
813 	if (!mtx_initialized(&devsoftc.mtx)) {
814 		devctl_queue_length = q;
815 		return (0);
816 	}
817 
818 	/*
819 	 * XXX It's hard to grow or shrink the UMA zone. Only allow
820 	 * disabling the queue size for the moment until underlying
821 	 * UMA issues can be sorted out.
822 	 */
823 	if (q != 0)
824 		return (EINVAL);
825 	if (q == devctl_queue_length)
826 		return (0);
827 	mtx_lock(&devsoftc.mtx);
828 	devctl_queue_length = 0;
829 	uma_zdestroy(devsoftc.zone);
830 	devsoftc.zone = 0;
831 	mtx_unlock(&devsoftc.mtx);
832 	return (0);
833 }
834 
835 /**
836  * @brief safely quotes strings that might have double quotes in them.
837  *
838  * The devctl protocol relies on quoted strings having matching quotes.
839  * This routine quotes any internal quotes so the resulting string
840  * is safe to pass to snprintf to construct, for example pnp info strings.
841  *
842  * @param sb	sbuf to place the characters into
843  * @param src	Original buffer.
844  */
845 void
846 devctl_safe_quote_sb(struct sbuf *sb, const char *src)
847 {
848 	while (*src != '\0') {
849 		if (*src == '"' || *src == '\\')
850 			sbuf_putc(sb, '\\');
851 		sbuf_putc(sb, *src++);
852 	}
853 }
854 
855 /* End of /dev/devctl code */
856 
857 static struct device_list bus_data_devices;
858 static int bus_data_generation = 1;
859 
860 static kobj_method_t null_methods[] = {
861 	KOBJMETHOD_END
862 };
863 
864 DEFINE_CLASS(null, null_methods, 0);
865 
866 /*
867  * Bus pass implementation
868  */
869 
870 static driver_list_t passes = TAILQ_HEAD_INITIALIZER(passes);
871 int bus_current_pass = BUS_PASS_ROOT;
872 
873 /**
874  * @internal
875  * @brief Register the pass level of a new driver attachment
876  *
877  * Register a new driver attachment's pass level.  If no driver
878  * attachment with the same pass level has been added, then @p new
879  * will be added to the global passes list.
880  *
881  * @param new		the new driver attachment
882  */
883 static void
884 driver_register_pass(struct driverlink *new)
885 {
886 	struct driverlink *dl;
887 
888 	/* We only consider pass numbers during boot. */
889 	if (bus_current_pass == BUS_PASS_DEFAULT)
890 		return;
891 
892 	/*
893 	 * Walk the passes list.  If we already know about this pass
894 	 * then there is nothing to do.  If we don't, then insert this
895 	 * driver link into the list.
896 	 */
897 	TAILQ_FOREACH(dl, &passes, passlink) {
898 		if (dl->pass < new->pass)
899 			continue;
900 		if (dl->pass == new->pass)
901 			return;
902 		TAILQ_INSERT_BEFORE(dl, new, passlink);
903 		return;
904 	}
905 	TAILQ_INSERT_TAIL(&passes, new, passlink);
906 }
907 
908 /**
909  * @brief Raise the current bus pass
910  *
911  * Raise the current bus pass level to @p pass.  Call the BUS_NEW_PASS()
912  * method on the root bus to kick off a new device tree scan for each
913  * new pass level that has at least one driver.
914  */
915 void
916 bus_set_pass(int pass)
917 {
918 	struct driverlink *dl;
919 
920 	if (bus_current_pass > pass)
921 		panic("Attempt to lower bus pass level");
922 
923 	TAILQ_FOREACH(dl, &passes, passlink) {
924 		/* Skip pass values below the current pass level. */
925 		if (dl->pass <= bus_current_pass)
926 			continue;
927 
928 		/*
929 		 * Bail once we hit a driver with a pass level that is
930 		 * too high.
931 		 */
932 		if (dl->pass > pass)
933 			break;
934 
935 		/*
936 		 * Raise the pass level to the next level and rescan
937 		 * the tree.
938 		 */
939 		bus_current_pass = dl->pass;
940 		BUS_NEW_PASS(root_bus);
941 	}
942 
943 	/*
944 	 * If there isn't a driver registered for the requested pass,
945 	 * then bus_current_pass might still be less than 'pass'.  Set
946 	 * it to 'pass' in that case.
947 	 */
948 	if (bus_current_pass < pass)
949 		bus_current_pass = pass;
950 	KASSERT(bus_current_pass == pass, ("Failed to update bus pass level"));
951 }
952 
953 /*
954  * Devclass implementation
955  */
956 
957 static devclass_list_t devclasses = TAILQ_HEAD_INITIALIZER(devclasses);
958 
959 /**
960  * @internal
961  * @brief Find or create a device class
962  *
963  * If a device class with the name @p classname exists, return it,
964  * otherwise if @p create is non-zero create and return a new device
965  * class.
966  *
967  * If @p parentname is non-NULL, the parent of the devclass is set to
968  * the devclass of that name.
969  *
970  * @param classname	the devclass name to find or create
971  * @param parentname	the parent devclass name or @c NULL
972  * @param create	non-zero to create a devclass
973  */
974 static devclass_t
975 devclass_find_internal(const char *classname, const char *parentname,
976 		       int create)
977 {
978 	devclass_t dc;
979 
980 	PDEBUG(("looking for %s", classname));
981 	if (!classname)
982 		return (NULL);
983 
984 	TAILQ_FOREACH(dc, &devclasses, link) {
985 		if (!strcmp(dc->name, classname))
986 			break;
987 	}
988 
989 	if (create && !dc) {
990 		PDEBUG(("creating %s", classname));
991 		dc = malloc(sizeof(struct devclass) + strlen(classname) + 1,
992 		    M_BUS, M_NOWAIT | M_ZERO);
993 		if (!dc)
994 			return (NULL);
995 		dc->parent = NULL;
996 		dc->name = (char*) (dc + 1);
997 		strcpy(dc->name, classname);
998 		TAILQ_INIT(&dc->drivers);
999 		TAILQ_INSERT_TAIL(&devclasses, dc, link);
1000 
1001 		bus_data_generation_update();
1002 	}
1003 
1004 	/*
1005 	 * If a parent class is specified, then set that as our parent so
1006 	 * that this devclass will support drivers for the parent class as
1007 	 * well.  If the parent class has the same name don't do this though
1008 	 * as it creates a cycle that can trigger an infinite loop in
1009 	 * device_probe_child() if a device exists for which there is no
1010 	 * suitable driver.
1011 	 */
1012 	if (parentname && dc && !dc->parent &&
1013 	    strcmp(classname, parentname) != 0) {
1014 		dc->parent = devclass_find_internal(parentname, NULL, TRUE);
1015 		dc->parent->flags |= DC_HAS_CHILDREN;
1016 	}
1017 
1018 	return (dc);
1019 }
1020 
1021 /**
1022  * @brief Create a device class
1023  *
1024  * If a device class with the name @p classname exists, return it,
1025  * otherwise create and return a new device class.
1026  *
1027  * @param classname	the devclass name to find or create
1028  */
1029 devclass_t
1030 devclass_create(const char *classname)
1031 {
1032 	return (devclass_find_internal(classname, NULL, TRUE));
1033 }
1034 
1035 /**
1036  * @brief Find a device class
1037  *
1038  * If a device class with the name @p classname exists, return it,
1039  * otherwise return @c NULL.
1040  *
1041  * @param classname	the devclass name to find
1042  */
1043 devclass_t
1044 devclass_find(const char *classname)
1045 {
1046 	return (devclass_find_internal(classname, NULL, FALSE));
1047 }
1048 
1049 /**
1050  * @brief Register that a device driver has been added to a devclass
1051  *
1052  * Register that a device driver has been added to a devclass.  This
1053  * is called by devclass_add_driver to accomplish the recursive
1054  * notification of all the children classes of dc, as well as dc.
1055  * Each layer will have BUS_DRIVER_ADDED() called for all instances of
1056  * the devclass.
1057  *
1058  * We do a full search here of the devclass list at each iteration
1059  * level to save storing children-lists in the devclass structure.  If
1060  * we ever move beyond a few dozen devices doing this, we may need to
1061  * reevaluate...
1062  *
1063  * @param dc		the devclass to edit
1064  * @param driver	the driver that was just added
1065  */
1066 static void
1067 devclass_driver_added(devclass_t dc, driver_t *driver)
1068 {
1069 	devclass_t parent;
1070 	int i;
1071 
1072 	/*
1073 	 * Call BUS_DRIVER_ADDED for any existing buses in this class.
1074 	 */
1075 	for (i = 0; i < dc->maxunit; i++)
1076 		if (dc->devices[i] && device_is_attached(dc->devices[i]))
1077 			BUS_DRIVER_ADDED(dc->devices[i], driver);
1078 
1079 	/*
1080 	 * Walk through the children classes.  Since we only keep a
1081 	 * single parent pointer around, we walk the entire list of
1082 	 * devclasses looking for children.  We set the
1083 	 * DC_HAS_CHILDREN flag when a child devclass is created on
1084 	 * the parent, so we only walk the list for those devclasses
1085 	 * that have children.
1086 	 */
1087 	if (!(dc->flags & DC_HAS_CHILDREN))
1088 		return;
1089 	parent = dc;
1090 	TAILQ_FOREACH(dc, &devclasses, link) {
1091 		if (dc->parent == parent)
1092 			devclass_driver_added(dc, driver);
1093 	}
1094 }
1095 
1096 /**
1097  * @brief Add a device driver to a device class
1098  *
1099  * Add a device driver to a devclass. This is normally called
1100  * automatically by DRIVER_MODULE(). The BUS_DRIVER_ADDED() method of
1101  * all devices in the devclass will be called to allow them to attempt
1102  * to re-probe any unmatched children.
1103  *
1104  * @param dc		the devclass to edit
1105  * @param driver	the driver to register
1106  */
1107 int
1108 devclass_add_driver(devclass_t dc, driver_t *driver, int pass, devclass_t *dcp)
1109 {
1110 	driverlink_t dl;
1111 	const char *parentname;
1112 
1113 	PDEBUG(("%s", DRIVERNAME(driver)));
1114 
1115 	/* Don't allow invalid pass values. */
1116 	if (pass <= BUS_PASS_ROOT)
1117 		return (EINVAL);
1118 
1119 	dl = malloc(sizeof *dl, M_BUS, M_NOWAIT|M_ZERO);
1120 	if (!dl)
1121 		return (ENOMEM);
1122 
1123 	/*
1124 	 * Compile the driver's methods. Also increase the reference count
1125 	 * so that the class doesn't get freed when the last instance
1126 	 * goes. This means we can safely use static methods and avoids a
1127 	 * double-free in devclass_delete_driver.
1128 	 */
1129 	kobj_class_compile((kobj_class_t) driver);
1130 
1131 	/*
1132 	 * If the driver has any base classes, make the
1133 	 * devclass inherit from the devclass of the driver's
1134 	 * first base class. This will allow the system to
1135 	 * search for drivers in both devclasses for children
1136 	 * of a device using this driver.
1137 	 */
1138 	if (driver->baseclasses)
1139 		parentname = driver->baseclasses[0]->name;
1140 	else
1141 		parentname = NULL;
1142 	*dcp = devclass_find_internal(driver->name, parentname, TRUE);
1143 
1144 	dl->driver = driver;
1145 	TAILQ_INSERT_TAIL(&dc->drivers, dl, link);
1146 	driver->refs++;		/* XXX: kobj_mtx */
1147 	dl->pass = pass;
1148 	driver_register_pass(dl);
1149 
1150 	if (device_frozen) {
1151 		dl->flags |= DL_DEFERRED_PROBE;
1152 	} else {
1153 		devclass_driver_added(dc, driver);
1154 	}
1155 	bus_data_generation_update();
1156 	return (0);
1157 }
1158 
1159 /**
1160  * @brief Register that a device driver has been deleted from a devclass
1161  *
1162  * Register that a device driver has been removed from a devclass.
1163  * This is called by devclass_delete_driver to accomplish the
1164  * recursive notification of all the children classes of busclass, as
1165  * well as busclass.  Each layer will attempt to detach the driver
1166  * from any devices that are children of the bus's devclass.  The function
1167  * will return an error if a device fails to detach.
1168  *
1169  * We do a full search here of the devclass list at each iteration
1170  * level to save storing children-lists in the devclass structure.  If
1171  * we ever move beyond a few dozen devices doing this, we may need to
1172  * reevaluate...
1173  *
1174  * @param busclass	the devclass of the parent bus
1175  * @param dc		the devclass of the driver being deleted
1176  * @param driver	the driver being deleted
1177  */
1178 static int
1179 devclass_driver_deleted(devclass_t busclass, devclass_t dc, driver_t *driver)
1180 {
1181 	devclass_t parent;
1182 	device_t dev;
1183 	int error, i;
1184 
1185 	/*
1186 	 * Disassociate from any devices.  We iterate through all the
1187 	 * devices in the devclass of the driver and detach any which are
1188 	 * using the driver and which have a parent in the devclass which
1189 	 * we are deleting from.
1190 	 *
1191 	 * Note that since a driver can be in multiple devclasses, we
1192 	 * should not detach devices which are not children of devices in
1193 	 * the affected devclass.
1194 	 *
1195 	 * If we're frozen, we don't generate NOMATCH events. Mark to
1196 	 * generate later.
1197 	 */
1198 	for (i = 0; i < dc->maxunit; i++) {
1199 		if (dc->devices[i]) {
1200 			dev = dc->devices[i];
1201 			if (dev->driver == driver && dev->parent &&
1202 			    dev->parent->devclass == busclass) {
1203 				if ((error = device_detach(dev)) != 0)
1204 					return (error);
1205 				if (device_frozen) {
1206 					dev->flags &= ~DF_DONENOMATCH;
1207 					dev->flags |= DF_NEEDNOMATCH;
1208 				} else {
1209 					BUS_PROBE_NOMATCH(dev->parent, dev);
1210 					devnomatch(dev);
1211 					dev->flags |= DF_DONENOMATCH;
1212 				}
1213 			}
1214 		}
1215 	}
1216 
1217 	/*
1218 	 * Walk through the children classes.  Since we only keep a
1219 	 * single parent pointer around, we walk the entire list of
1220 	 * devclasses looking for children.  We set the
1221 	 * DC_HAS_CHILDREN flag when a child devclass is created on
1222 	 * the parent, so we only walk the list for those devclasses
1223 	 * that have children.
1224 	 */
1225 	if (!(busclass->flags & DC_HAS_CHILDREN))
1226 		return (0);
1227 	parent = busclass;
1228 	TAILQ_FOREACH(busclass, &devclasses, link) {
1229 		if (busclass->parent == parent) {
1230 			error = devclass_driver_deleted(busclass, dc, driver);
1231 			if (error)
1232 				return (error);
1233 		}
1234 	}
1235 	return (0);
1236 }
1237 
1238 /**
1239  * @brief Delete a device driver from a device class
1240  *
1241  * Delete a device driver from a devclass. This is normally called
1242  * automatically by DRIVER_MODULE().
1243  *
1244  * If the driver is currently attached to any devices,
1245  * devclass_delete_driver() will first attempt to detach from each
1246  * device. If one of the detach calls fails, the driver will not be
1247  * deleted.
1248  *
1249  * @param dc		the devclass to edit
1250  * @param driver	the driver to unregister
1251  */
1252 int
1253 devclass_delete_driver(devclass_t busclass, driver_t *driver)
1254 {
1255 	devclass_t dc = devclass_find(driver->name);
1256 	driverlink_t dl;
1257 	int error;
1258 
1259 	PDEBUG(("%s from devclass %s", driver->name, DEVCLANAME(busclass)));
1260 
1261 	if (!dc)
1262 		return (0);
1263 
1264 	/*
1265 	 * Find the link structure in the bus' list of drivers.
1266 	 */
1267 	TAILQ_FOREACH(dl, &busclass->drivers, link) {
1268 		if (dl->driver == driver)
1269 			break;
1270 	}
1271 
1272 	if (!dl) {
1273 		PDEBUG(("%s not found in %s list", driver->name,
1274 		    busclass->name));
1275 		return (ENOENT);
1276 	}
1277 
1278 	error = devclass_driver_deleted(busclass, dc, driver);
1279 	if (error != 0)
1280 		return (error);
1281 
1282 	TAILQ_REMOVE(&busclass->drivers, dl, link);
1283 	free(dl, M_BUS);
1284 
1285 	/* XXX: kobj_mtx */
1286 	driver->refs--;
1287 	if (driver->refs == 0)
1288 		kobj_class_free((kobj_class_t) driver);
1289 
1290 	bus_data_generation_update();
1291 	return (0);
1292 }
1293 
1294 /**
1295  * @brief Quiesces a set of device drivers from a device class
1296  *
1297  * Quiesce a device driver from a devclass. This is normally called
1298  * automatically by DRIVER_MODULE().
1299  *
1300  * If the driver is currently attached to any devices,
1301  * devclass_quiesece_driver() will first attempt to quiesce each
1302  * device.
1303  *
1304  * @param dc		the devclass to edit
1305  * @param driver	the driver to unregister
1306  */
1307 static int
1308 devclass_quiesce_driver(devclass_t busclass, driver_t *driver)
1309 {
1310 	devclass_t dc = devclass_find(driver->name);
1311 	driverlink_t dl;
1312 	device_t dev;
1313 	int i;
1314 	int error;
1315 
1316 	PDEBUG(("%s from devclass %s", driver->name, DEVCLANAME(busclass)));
1317 
1318 	if (!dc)
1319 		return (0);
1320 
1321 	/*
1322 	 * Find the link structure in the bus' list of drivers.
1323 	 */
1324 	TAILQ_FOREACH(dl, &busclass->drivers, link) {
1325 		if (dl->driver == driver)
1326 			break;
1327 	}
1328 
1329 	if (!dl) {
1330 		PDEBUG(("%s not found in %s list", driver->name,
1331 		    busclass->name));
1332 		return (ENOENT);
1333 	}
1334 
1335 	/*
1336 	 * Quiesce all devices.  We iterate through all the devices in
1337 	 * the devclass of the driver and quiesce any which are using
1338 	 * the driver and which have a parent in the devclass which we
1339 	 * are quiescing.
1340 	 *
1341 	 * Note that since a driver can be in multiple devclasses, we
1342 	 * should not quiesce devices which are not children of
1343 	 * devices in the affected devclass.
1344 	 */
1345 	for (i = 0; i < dc->maxunit; i++) {
1346 		if (dc->devices[i]) {
1347 			dev = dc->devices[i];
1348 			if (dev->driver == driver && dev->parent &&
1349 			    dev->parent->devclass == busclass) {
1350 				if ((error = device_quiesce(dev)) != 0)
1351 					return (error);
1352 			}
1353 		}
1354 	}
1355 
1356 	return (0);
1357 }
1358 
1359 /**
1360  * @internal
1361  */
1362 static driverlink_t
1363 devclass_find_driver_internal(devclass_t dc, const char *classname)
1364 {
1365 	driverlink_t dl;
1366 
1367 	PDEBUG(("%s in devclass %s", classname, DEVCLANAME(dc)));
1368 
1369 	TAILQ_FOREACH(dl, &dc->drivers, link) {
1370 		if (!strcmp(dl->driver->name, classname))
1371 			return (dl);
1372 	}
1373 
1374 	PDEBUG(("not found"));
1375 	return (NULL);
1376 }
1377 
1378 /**
1379  * @brief Return the name of the devclass
1380  */
1381 const char *
1382 devclass_get_name(devclass_t dc)
1383 {
1384 	return (dc->name);
1385 }
1386 
1387 /**
1388  * @brief Find a device given a unit number
1389  *
1390  * @param dc		the devclass to search
1391  * @param unit		the unit number to search for
1392  *
1393  * @returns		the device with the given unit number or @c
1394  *			NULL if there is no such device
1395  */
1396 device_t
1397 devclass_get_device(devclass_t dc, int unit)
1398 {
1399 	if (dc == NULL || unit < 0 || unit >= dc->maxunit)
1400 		return (NULL);
1401 	return (dc->devices[unit]);
1402 }
1403 
1404 /**
1405  * @brief Find the softc field of a device given a unit number
1406  *
1407  * @param dc		the devclass to search
1408  * @param unit		the unit number to search for
1409  *
1410  * @returns		the softc field of the device with the given
1411  *			unit number or @c NULL if there is no such
1412  *			device
1413  */
1414 void *
1415 devclass_get_softc(devclass_t dc, int unit)
1416 {
1417 	device_t dev;
1418 
1419 	dev = devclass_get_device(dc, unit);
1420 	if (!dev)
1421 		return (NULL);
1422 
1423 	return (device_get_softc(dev));
1424 }
1425 
1426 /**
1427  * @brief Get a list of devices in the devclass
1428  *
1429  * An array containing a list of all the devices in the given devclass
1430  * is allocated and returned in @p *devlistp. The number of devices
1431  * in the array is returned in @p *devcountp. The caller should free
1432  * the array using @c free(p, M_TEMP), even if @p *devcountp is 0.
1433  *
1434  * @param dc		the devclass to examine
1435  * @param devlistp	points at location for array pointer return
1436  *			value
1437  * @param devcountp	points at location for array size return value
1438  *
1439  * @retval 0		success
1440  * @retval ENOMEM	the array allocation failed
1441  */
1442 int
1443 devclass_get_devices(devclass_t dc, device_t **devlistp, int *devcountp)
1444 {
1445 	int count, i;
1446 	device_t *list;
1447 
1448 	count = devclass_get_count(dc);
1449 	list = malloc(count * sizeof(device_t), M_TEMP, M_NOWAIT|M_ZERO);
1450 	if (!list)
1451 		return (ENOMEM);
1452 
1453 	count = 0;
1454 	for (i = 0; i < dc->maxunit; i++) {
1455 		if (dc->devices[i]) {
1456 			list[count] = dc->devices[i];
1457 			count++;
1458 		}
1459 	}
1460 
1461 	*devlistp = list;
1462 	*devcountp = count;
1463 
1464 	return (0);
1465 }
1466 
1467 /**
1468  * @brief Get a list of drivers in the devclass
1469  *
1470  * An array containing a list of pointers to all the drivers in the
1471  * given devclass is allocated and returned in @p *listp.  The number
1472  * of drivers in the array is returned in @p *countp. The caller should
1473  * free the array using @c free(p, M_TEMP).
1474  *
1475  * @param dc		the devclass to examine
1476  * @param listp		gives location for array pointer return value
1477  * @param countp	gives location for number of array elements
1478  *			return value
1479  *
1480  * @retval 0		success
1481  * @retval ENOMEM	the array allocation failed
1482  */
1483 int
1484 devclass_get_drivers(devclass_t dc, driver_t ***listp, int *countp)
1485 {
1486 	driverlink_t dl;
1487 	driver_t **list;
1488 	int count;
1489 
1490 	count = 0;
1491 	TAILQ_FOREACH(dl, &dc->drivers, link)
1492 		count++;
1493 	list = malloc(count * sizeof(driver_t *), M_TEMP, M_NOWAIT);
1494 	if (list == NULL)
1495 		return (ENOMEM);
1496 
1497 	count = 0;
1498 	TAILQ_FOREACH(dl, &dc->drivers, link) {
1499 		list[count] = dl->driver;
1500 		count++;
1501 	}
1502 	*listp = list;
1503 	*countp = count;
1504 
1505 	return (0);
1506 }
1507 
1508 /**
1509  * @brief Get the number of devices in a devclass
1510  *
1511  * @param dc		the devclass to examine
1512  */
1513 int
1514 devclass_get_count(devclass_t dc)
1515 {
1516 	int count, i;
1517 
1518 	count = 0;
1519 	for (i = 0; i < dc->maxunit; i++)
1520 		if (dc->devices[i])
1521 			count++;
1522 	return (count);
1523 }
1524 
1525 /**
1526  * @brief Get the maximum unit number used in a devclass
1527  *
1528  * Note that this is one greater than the highest currently-allocated
1529  * unit.  If a null devclass_t is passed in, -1 is returned to indicate
1530  * that not even the devclass has been allocated yet.
1531  *
1532  * @param dc		the devclass to examine
1533  */
1534 int
1535 devclass_get_maxunit(devclass_t dc)
1536 {
1537 	if (dc == NULL)
1538 		return (-1);
1539 	return (dc->maxunit);
1540 }
1541 
1542 /**
1543  * @brief Find a free unit number in a devclass
1544  *
1545  * This function searches for the first unused unit number greater
1546  * that or equal to @p unit.
1547  *
1548  * @param dc		the devclass to examine
1549  * @param unit		the first unit number to check
1550  */
1551 int
1552 devclass_find_free_unit(devclass_t dc, int unit)
1553 {
1554 	if (dc == NULL)
1555 		return (unit);
1556 	while (unit < dc->maxunit && dc->devices[unit] != NULL)
1557 		unit++;
1558 	return (unit);
1559 }
1560 
1561 /**
1562  * @brief Set the parent of a devclass
1563  *
1564  * The parent class is normally initialised automatically by
1565  * DRIVER_MODULE().
1566  *
1567  * @param dc		the devclass to edit
1568  * @param pdc		the new parent devclass
1569  */
1570 void
1571 devclass_set_parent(devclass_t dc, devclass_t pdc)
1572 {
1573 	dc->parent = pdc;
1574 }
1575 
1576 /**
1577  * @brief Get the parent of a devclass
1578  *
1579  * @param dc		the devclass to examine
1580  */
1581 devclass_t
1582 devclass_get_parent(devclass_t dc)
1583 {
1584 	return (dc->parent);
1585 }
1586 
1587 struct sysctl_ctx_list *
1588 devclass_get_sysctl_ctx(devclass_t dc)
1589 {
1590 	return (&dc->sysctl_ctx);
1591 }
1592 
1593 struct sysctl_oid *
1594 devclass_get_sysctl_tree(devclass_t dc)
1595 {
1596 	return (dc->sysctl_tree);
1597 }
1598 
1599 /**
1600  * @internal
1601  * @brief Allocate a unit number
1602  *
1603  * On entry, @p *unitp is the desired unit number (or @c -1 if any
1604  * will do). The allocated unit number is returned in @p *unitp.
1605 
1606  * @param dc		the devclass to allocate from
1607  * @param unitp		points at the location for the allocated unit
1608  *			number
1609  *
1610  * @retval 0		success
1611  * @retval EEXIST	the requested unit number is already allocated
1612  * @retval ENOMEM	memory allocation failure
1613  */
1614 static int
1615 devclass_alloc_unit(devclass_t dc, device_t dev, int *unitp)
1616 {
1617 	const char *s;
1618 	int unit = *unitp;
1619 
1620 	PDEBUG(("unit %d in devclass %s", unit, DEVCLANAME(dc)));
1621 
1622 	/* Ask the parent bus if it wants to wire this device. */
1623 	if (unit == -1)
1624 		BUS_HINT_DEVICE_UNIT(device_get_parent(dev), dev, dc->name,
1625 		    &unit);
1626 
1627 	/* If we were given a wired unit number, check for existing device */
1628 	/* XXX imp XXX */
1629 	if (unit != -1) {
1630 		if (unit >= 0 && unit < dc->maxunit &&
1631 		    dc->devices[unit] != NULL) {
1632 			if (bootverbose)
1633 				printf("%s: %s%d already exists; skipping it\n",
1634 				    dc->name, dc->name, *unitp);
1635 			return (EEXIST);
1636 		}
1637 	} else {
1638 		/* Unwired device, find the next available slot for it */
1639 		unit = 0;
1640 		for (unit = 0;; unit++) {
1641 			/* If this device slot is already in use, skip it. */
1642 			if (unit < dc->maxunit && dc->devices[unit] != NULL)
1643 				continue;
1644 
1645 			/* If there is an "at" hint for a unit then skip it. */
1646 			if (resource_string_value(dc->name, unit, "at", &s) ==
1647 			    0)
1648 				continue;
1649 
1650 			break;
1651 		}
1652 	}
1653 
1654 	/*
1655 	 * We've selected a unit beyond the length of the table, so let's
1656 	 * extend the table to make room for all units up to and including
1657 	 * this one.
1658 	 */
1659 	if (unit >= dc->maxunit) {
1660 		device_t *newlist, *oldlist;
1661 		int newsize;
1662 
1663 		oldlist = dc->devices;
1664 		newsize = roundup((unit + 1),
1665 		    MAX(1, MINALLOCSIZE / sizeof(device_t)));
1666 		newlist = malloc(sizeof(device_t) * newsize, M_BUS, M_NOWAIT);
1667 		if (!newlist)
1668 			return (ENOMEM);
1669 		if (oldlist != NULL)
1670 			bcopy(oldlist, newlist, sizeof(device_t) * dc->maxunit);
1671 		bzero(newlist + dc->maxunit,
1672 		    sizeof(device_t) * (newsize - dc->maxunit));
1673 		dc->devices = newlist;
1674 		dc->maxunit = newsize;
1675 		if (oldlist != NULL)
1676 			free(oldlist, M_BUS);
1677 	}
1678 	PDEBUG(("now: unit %d in devclass %s", unit, DEVCLANAME(dc)));
1679 
1680 	*unitp = unit;
1681 	return (0);
1682 }
1683 
1684 /**
1685  * @internal
1686  * @brief Add a device to a devclass
1687  *
1688  * A unit number is allocated for the device (using the device's
1689  * preferred unit number if any) and the device is registered in the
1690  * devclass. This allows the device to be looked up by its unit
1691  * number, e.g. by decoding a dev_t minor number.
1692  *
1693  * @param dc		the devclass to add to
1694  * @param dev		the device to add
1695  *
1696  * @retval 0		success
1697  * @retval EEXIST	the requested unit number is already allocated
1698  * @retval ENOMEM	memory allocation failure
1699  */
1700 static int
1701 devclass_add_device(devclass_t dc, device_t dev)
1702 {
1703 	int buflen, error;
1704 
1705 	PDEBUG(("%s in devclass %s", DEVICENAME(dev), DEVCLANAME(dc)));
1706 
1707 	buflen = snprintf(NULL, 0, "%s%d$", dc->name, INT_MAX);
1708 	if (buflen < 0)
1709 		return (ENOMEM);
1710 	dev->nameunit = malloc(buflen, M_BUS, M_NOWAIT|M_ZERO);
1711 	if (!dev->nameunit)
1712 		return (ENOMEM);
1713 
1714 	if ((error = devclass_alloc_unit(dc, dev, &dev->unit)) != 0) {
1715 		free(dev->nameunit, M_BUS);
1716 		dev->nameunit = NULL;
1717 		return (error);
1718 	}
1719 	dc->devices[dev->unit] = dev;
1720 	dev->devclass = dc;
1721 	snprintf(dev->nameunit, buflen, "%s%d", dc->name, dev->unit);
1722 
1723 	return (0);
1724 }
1725 
1726 /**
1727  * @internal
1728  * @brief Delete a device from a devclass
1729  *
1730  * The device is removed from the devclass's device list and its unit
1731  * number is freed.
1732 
1733  * @param dc		the devclass to delete from
1734  * @param dev		the device to delete
1735  *
1736  * @retval 0		success
1737  */
1738 static int
1739 devclass_delete_device(devclass_t dc, device_t dev)
1740 {
1741 	if (!dc || !dev)
1742 		return (0);
1743 
1744 	PDEBUG(("%s in devclass %s", DEVICENAME(dev), DEVCLANAME(dc)));
1745 
1746 	if (dev->devclass != dc || dc->devices[dev->unit] != dev)
1747 		panic("devclass_delete_device: inconsistent device class");
1748 	dc->devices[dev->unit] = NULL;
1749 	if (dev->flags & DF_WILDCARD)
1750 		dev->unit = -1;
1751 	dev->devclass = NULL;
1752 	free(dev->nameunit, M_BUS);
1753 	dev->nameunit = NULL;
1754 
1755 	return (0);
1756 }
1757 
1758 /**
1759  * @internal
1760  * @brief Make a new device and add it as a child of @p parent
1761  *
1762  * @param parent	the parent of the new device
1763  * @param name		the devclass name of the new device or @c NULL
1764  *			to leave the devclass unspecified
1765  * @parem unit		the unit number of the new device of @c -1 to
1766  *			leave the unit number unspecified
1767  *
1768  * @returns the new device
1769  */
1770 static device_t
1771 make_device(device_t parent, const char *name, int unit)
1772 {
1773 	device_t dev;
1774 	devclass_t dc;
1775 
1776 	PDEBUG(("%s at %s as unit %d", name, DEVICENAME(parent), unit));
1777 
1778 	if (name) {
1779 		dc = devclass_find_internal(name, NULL, TRUE);
1780 		if (!dc) {
1781 			printf("make_device: can't find device class %s\n",
1782 			    name);
1783 			return (NULL);
1784 		}
1785 	} else {
1786 		dc = NULL;
1787 	}
1788 
1789 	dev = malloc(sizeof(*dev), M_BUS, M_NOWAIT|M_ZERO);
1790 	if (!dev)
1791 		return (NULL);
1792 
1793 	dev->parent = parent;
1794 	TAILQ_INIT(&dev->children);
1795 	kobj_init((kobj_t) dev, &null_class);
1796 	dev->driver = NULL;
1797 	dev->devclass = NULL;
1798 	dev->unit = unit;
1799 	dev->nameunit = NULL;
1800 	dev->desc = NULL;
1801 	dev->busy = 0;
1802 	dev->devflags = 0;
1803 	dev->flags = DF_ENABLED;
1804 	dev->order = 0;
1805 	if (unit == -1)
1806 		dev->flags |= DF_WILDCARD;
1807 	if (name) {
1808 		dev->flags |= DF_FIXEDCLASS;
1809 		if (devclass_add_device(dc, dev)) {
1810 			kobj_delete((kobj_t) dev, M_BUS);
1811 			return (NULL);
1812 		}
1813 	}
1814 	if (parent != NULL && device_has_quiet_children(parent))
1815 		dev->flags |= DF_QUIET | DF_QUIET_CHILDREN;
1816 	dev->ivars = NULL;
1817 	dev->softc = NULL;
1818 
1819 	dev->state = DS_NOTPRESENT;
1820 
1821 	TAILQ_INSERT_TAIL(&bus_data_devices, dev, devlink);
1822 	bus_data_generation_update();
1823 
1824 	return (dev);
1825 }
1826 
1827 /**
1828  * @internal
1829  * @brief Print a description of a device.
1830  */
1831 static int
1832 device_print_child(device_t dev, device_t child)
1833 {
1834 	int retval = 0;
1835 
1836 	if (device_is_alive(child))
1837 		retval += BUS_PRINT_CHILD(dev, child);
1838 	else
1839 		retval += device_printf(child, " not found\n");
1840 
1841 	return (retval);
1842 }
1843 
1844 /**
1845  * @brief Create a new device
1846  *
1847  * This creates a new device and adds it as a child of an existing
1848  * parent device. The new device will be added after the last existing
1849  * child with order zero.
1850  *
1851  * @param dev		the device which will be the parent of the
1852  *			new child device
1853  * @param name		devclass name for new device or @c NULL if not
1854  *			specified
1855  * @param unit		unit number for new device or @c -1 if not
1856  *			specified
1857  *
1858  * @returns		the new device
1859  */
1860 device_t
1861 device_add_child(device_t dev, const char *name, int unit)
1862 {
1863 	return (device_add_child_ordered(dev, 0, name, unit));
1864 }
1865 
1866 /**
1867  * @brief Create a new device
1868  *
1869  * This creates a new device and adds it as a child of an existing
1870  * parent device. The new device will be added after the last existing
1871  * child with the same order.
1872  *
1873  * @param dev		the device which will be the parent of the
1874  *			new child device
1875  * @param order		a value which is used to partially sort the
1876  *			children of @p dev - devices created using
1877  *			lower values of @p order appear first in @p
1878  *			dev's list of children
1879  * @param name		devclass name for new device or @c NULL if not
1880  *			specified
1881  * @param unit		unit number for new device or @c -1 if not
1882  *			specified
1883  *
1884  * @returns		the new device
1885  */
1886 device_t
1887 device_add_child_ordered(device_t dev, u_int order, const char *name, int unit)
1888 {
1889 	device_t child;
1890 	device_t place;
1891 
1892 	PDEBUG(("%s at %s with order %u as unit %d",
1893 	    name, DEVICENAME(dev), order, unit));
1894 	KASSERT(name != NULL || unit == -1,
1895 	    ("child device with wildcard name and specific unit number"));
1896 
1897 	child = make_device(dev, name, unit);
1898 	if (child == NULL)
1899 		return (child);
1900 	child->order = order;
1901 
1902 	TAILQ_FOREACH(place, &dev->children, link) {
1903 		if (place->order > order)
1904 			break;
1905 	}
1906 
1907 	if (place) {
1908 		/*
1909 		 * The device 'place' is the first device whose order is
1910 		 * greater than the new child.
1911 		 */
1912 		TAILQ_INSERT_BEFORE(place, child, link);
1913 	} else {
1914 		/*
1915 		 * The new child's order is greater or equal to the order of
1916 		 * any existing device. Add the child to the tail of the list.
1917 		 */
1918 		TAILQ_INSERT_TAIL(&dev->children, child, link);
1919 	}
1920 
1921 	bus_data_generation_update();
1922 	return (child);
1923 }
1924 
1925 /**
1926  * @brief Delete a device
1927  *
1928  * This function deletes a device along with all of its children. If
1929  * the device currently has a driver attached to it, the device is
1930  * detached first using device_detach().
1931  *
1932  * @param dev		the parent device
1933  * @param child		the device to delete
1934  *
1935  * @retval 0		success
1936  * @retval non-zero	a unit error code describing the error
1937  */
1938 int
1939 device_delete_child(device_t dev, device_t child)
1940 {
1941 	int error;
1942 	device_t grandchild;
1943 
1944 	PDEBUG(("%s from %s", DEVICENAME(child), DEVICENAME(dev)));
1945 
1946 	/* detach parent before deleting children, if any */
1947 	if ((error = device_detach(child)) != 0)
1948 		return (error);
1949 
1950 	/* remove children second */
1951 	while ((grandchild = TAILQ_FIRST(&child->children)) != NULL) {
1952 		error = device_delete_child(child, grandchild);
1953 		if (error)
1954 			return (error);
1955 	}
1956 
1957 	if (child->devclass)
1958 		devclass_delete_device(child->devclass, child);
1959 	if (child->parent)
1960 		BUS_CHILD_DELETED(dev, child);
1961 	TAILQ_REMOVE(&dev->children, child, link);
1962 	TAILQ_REMOVE(&bus_data_devices, child, devlink);
1963 	kobj_delete((kobj_t) child, M_BUS);
1964 
1965 	bus_data_generation_update();
1966 	return (0);
1967 }
1968 
1969 /**
1970  * @brief Delete all children devices of the given device, if any.
1971  *
1972  * This function deletes all children devices of the given device, if
1973  * any, using the device_delete_child() function for each device it
1974  * finds. If a child device cannot be deleted, this function will
1975  * return an error code.
1976  *
1977  * @param dev		the parent device
1978  *
1979  * @retval 0		success
1980  * @retval non-zero	a device would not detach
1981  */
1982 int
1983 device_delete_children(device_t dev)
1984 {
1985 	device_t child;
1986 	int error;
1987 
1988 	PDEBUG(("Deleting all children of %s", DEVICENAME(dev)));
1989 
1990 	error = 0;
1991 
1992 	while ((child = TAILQ_FIRST(&dev->children)) != NULL) {
1993 		error = device_delete_child(dev, child);
1994 		if (error) {
1995 			PDEBUG(("Failed deleting %s", DEVICENAME(child)));
1996 			break;
1997 		}
1998 	}
1999 	return (error);
2000 }
2001 
2002 /**
2003  * @brief Find a device given a unit number
2004  *
2005  * This is similar to devclass_get_devices() but only searches for
2006  * devices which have @p dev as a parent.
2007  *
2008  * @param dev		the parent device to search
2009  * @param unit		the unit number to search for.  If the unit is -1,
2010  *			return the first child of @p dev which has name
2011  *			@p classname (that is, the one with the lowest unit.)
2012  *
2013  * @returns		the device with the given unit number or @c
2014  *			NULL if there is no such device
2015  */
2016 device_t
2017 device_find_child(device_t dev, const char *classname, int unit)
2018 {
2019 	devclass_t dc;
2020 	device_t child;
2021 
2022 	dc = devclass_find(classname);
2023 	if (!dc)
2024 		return (NULL);
2025 
2026 	if (unit != -1) {
2027 		child = devclass_get_device(dc, unit);
2028 		if (child && child->parent == dev)
2029 			return (child);
2030 	} else {
2031 		for (unit = 0; unit < devclass_get_maxunit(dc); unit++) {
2032 			child = devclass_get_device(dc, unit);
2033 			if (child && child->parent == dev)
2034 				return (child);
2035 		}
2036 	}
2037 	return (NULL);
2038 }
2039 
2040 /**
2041  * @internal
2042  */
2043 static driverlink_t
2044 first_matching_driver(devclass_t dc, device_t dev)
2045 {
2046 	if (dev->devclass)
2047 		return (devclass_find_driver_internal(dc, dev->devclass->name));
2048 	return (TAILQ_FIRST(&dc->drivers));
2049 }
2050 
2051 /**
2052  * @internal
2053  */
2054 static driverlink_t
2055 next_matching_driver(devclass_t dc, device_t dev, driverlink_t last)
2056 {
2057 	if (dev->devclass) {
2058 		driverlink_t dl;
2059 		for (dl = TAILQ_NEXT(last, link); dl; dl = TAILQ_NEXT(dl, link))
2060 			if (!strcmp(dev->devclass->name, dl->driver->name))
2061 				return (dl);
2062 		return (NULL);
2063 	}
2064 	return (TAILQ_NEXT(last, link));
2065 }
2066 
2067 /**
2068  * @internal
2069  */
2070 int
2071 device_probe_child(device_t dev, device_t child)
2072 {
2073 	devclass_t dc;
2074 	driverlink_t best = NULL;
2075 	driverlink_t dl;
2076 	int result, pri = 0;
2077 	int hasclass = (child->devclass != NULL);
2078 
2079 	GIANT_REQUIRED;
2080 
2081 	dc = dev->devclass;
2082 	if (!dc)
2083 		panic("device_probe_child: parent device has no devclass");
2084 
2085 	/*
2086 	 * If the state is already probed, then return.  However, don't
2087 	 * return if we can rebid this object.
2088 	 */
2089 	if (child->state == DS_ALIVE && (child->flags & DF_REBID) == 0)
2090 		return (0);
2091 
2092 	for (; dc; dc = dc->parent) {
2093 		for (dl = first_matching_driver(dc, child);
2094 		     dl;
2095 		     dl = next_matching_driver(dc, child, dl)) {
2096 			/* If this driver's pass is too high, then ignore it. */
2097 			if (dl->pass > bus_current_pass)
2098 				continue;
2099 
2100 			PDEBUG(("Trying %s", DRIVERNAME(dl->driver)));
2101 			result = device_set_driver(child, dl->driver);
2102 			if (result == ENOMEM)
2103 				return (result);
2104 			else if (result != 0)
2105 				continue;
2106 			if (!hasclass) {
2107 				if (device_set_devclass(child,
2108 				    dl->driver->name) != 0) {
2109 					char const * devname =
2110 					    device_get_name(child);
2111 					if (devname == NULL)
2112 						devname = "(unknown)";
2113 					printf("driver bug: Unable to set "
2114 					    "devclass (class: %s "
2115 					    "devname: %s)\n",
2116 					    dl->driver->name,
2117 					    devname);
2118 					(void)device_set_driver(child, NULL);
2119 					continue;
2120 				}
2121 			}
2122 
2123 			/* Fetch any flags for the device before probing. */
2124 			resource_int_value(dl->driver->name, child->unit,
2125 			    "flags", &child->devflags);
2126 
2127 			result = DEVICE_PROBE(child);
2128 
2129 			/* Reset flags and devclass before the next probe. */
2130 			child->devflags = 0;
2131 			if (!hasclass)
2132 				(void)device_set_devclass(child, NULL);
2133 
2134 			/*
2135 			 * If the driver returns SUCCESS, there can be
2136 			 * no higher match for this device.
2137 			 */
2138 			if (result == 0) {
2139 				best = dl;
2140 				pri = 0;
2141 				break;
2142 			}
2143 
2144 			/*
2145 			 * Reset DF_QUIET in case this driver doesn't
2146 			 * end up as the best driver.
2147 			 */
2148 			device_verbose(child);
2149 
2150 			/*
2151 			 * Probes that return BUS_PROBE_NOWILDCARD or lower
2152 			 * only match on devices whose driver was explicitly
2153 			 * specified.
2154 			 */
2155 			if (result <= BUS_PROBE_NOWILDCARD &&
2156 			    !(child->flags & DF_FIXEDCLASS)) {
2157 				result = ENXIO;
2158 			}
2159 
2160 			/*
2161 			 * The driver returned an error so it
2162 			 * certainly doesn't match.
2163 			 */
2164 			if (result > 0) {
2165 				(void)device_set_driver(child, NULL);
2166 				continue;
2167 			}
2168 
2169 			/*
2170 			 * A priority lower than SUCCESS, remember the
2171 			 * best matching driver. Initialise the value
2172 			 * of pri for the first match.
2173 			 */
2174 			if (best == NULL || result > pri) {
2175 				best = dl;
2176 				pri = result;
2177 				continue;
2178 			}
2179 		}
2180 		/*
2181 		 * If we have an unambiguous match in this devclass,
2182 		 * don't look in the parent.
2183 		 */
2184 		if (best && pri == 0)
2185 			break;
2186 	}
2187 
2188 	/*
2189 	 * If we found a driver, change state and initialise the devclass.
2190 	 */
2191 	/* XXX What happens if we rebid and got no best? */
2192 	if (best) {
2193 		/*
2194 		 * If this device was attached, and we were asked to
2195 		 * rescan, and it is a different driver, then we have
2196 		 * to detach the old driver and reattach this new one.
2197 		 * Note, we don't have to check for DF_REBID here
2198 		 * because if the state is > DS_ALIVE, we know it must
2199 		 * be.
2200 		 *
2201 		 * This assumes that all DF_REBID drivers can have
2202 		 * their probe routine called at any time and that
2203 		 * they are idempotent as well as completely benign in
2204 		 * normal operations.
2205 		 *
2206 		 * We also have to make sure that the detach
2207 		 * succeeded, otherwise we fail the operation (or
2208 		 * maybe it should just fail silently?  I'm torn).
2209 		 */
2210 		if (child->state > DS_ALIVE && best->driver != child->driver)
2211 			if ((result = device_detach(dev)) != 0)
2212 				return (result);
2213 
2214 		/* Set the winning driver, devclass, and flags. */
2215 		if (!child->devclass) {
2216 			result = device_set_devclass(child, best->driver->name);
2217 			if (result != 0)
2218 				return (result);
2219 		}
2220 		result = device_set_driver(child, best->driver);
2221 		if (result != 0)
2222 			return (result);
2223 		resource_int_value(best->driver->name, child->unit,
2224 		    "flags", &child->devflags);
2225 
2226 		if (pri < 0) {
2227 			/*
2228 			 * A bit bogus. Call the probe method again to make
2229 			 * sure that we have the right description.
2230 			 */
2231 			DEVICE_PROBE(child);
2232 #if 0
2233 			child->flags |= DF_REBID;
2234 #endif
2235 		} else
2236 			child->flags &= ~DF_REBID;
2237 		child->state = DS_ALIVE;
2238 
2239 		bus_data_generation_update();
2240 		return (0);
2241 	}
2242 
2243 	return (ENXIO);
2244 }
2245 
2246 /**
2247  * @brief Return the parent of a device
2248  */
2249 device_t
2250 device_get_parent(device_t dev)
2251 {
2252 	return (dev->parent);
2253 }
2254 
2255 /**
2256  * @brief Get a list of children of a device
2257  *
2258  * An array containing a list of all the children of the given device
2259  * is allocated and returned in @p *devlistp. The number of devices
2260  * in the array is returned in @p *devcountp. The caller should free
2261  * the array using @c free(p, M_TEMP).
2262  *
2263  * @param dev		the device to examine
2264  * @param devlistp	points at location for array pointer return
2265  *			value
2266  * @param devcountp	points at location for array size return value
2267  *
2268  * @retval 0		success
2269  * @retval ENOMEM	the array allocation failed
2270  */
2271 int
2272 device_get_children(device_t dev, device_t **devlistp, int *devcountp)
2273 {
2274 	int count;
2275 	device_t child;
2276 	device_t *list;
2277 
2278 	count = 0;
2279 	TAILQ_FOREACH(child, &dev->children, link) {
2280 		count++;
2281 	}
2282 	if (count == 0) {
2283 		*devlistp = NULL;
2284 		*devcountp = 0;
2285 		return (0);
2286 	}
2287 
2288 	list = malloc(count * sizeof(device_t), M_TEMP, M_NOWAIT|M_ZERO);
2289 	if (!list)
2290 		return (ENOMEM);
2291 
2292 	count = 0;
2293 	TAILQ_FOREACH(child, &dev->children, link) {
2294 		list[count] = child;
2295 		count++;
2296 	}
2297 
2298 	*devlistp = list;
2299 	*devcountp = count;
2300 
2301 	return (0);
2302 }
2303 
2304 /**
2305  * @brief Return the current driver for the device or @c NULL if there
2306  * is no driver currently attached
2307  */
2308 driver_t *
2309 device_get_driver(device_t dev)
2310 {
2311 	return (dev->driver);
2312 }
2313 
2314 /**
2315  * @brief Return the current devclass for the device or @c NULL if
2316  * there is none.
2317  */
2318 devclass_t
2319 device_get_devclass(device_t dev)
2320 {
2321 	return (dev->devclass);
2322 }
2323 
2324 /**
2325  * @brief Return the name of the device's devclass or @c NULL if there
2326  * is none.
2327  */
2328 const char *
2329 device_get_name(device_t dev)
2330 {
2331 	if (dev != NULL && dev->devclass)
2332 		return (devclass_get_name(dev->devclass));
2333 	return (NULL);
2334 }
2335 
2336 /**
2337  * @brief Return a string containing the device's devclass name
2338  * followed by an ascii representation of the device's unit number
2339  * (e.g. @c "foo2").
2340  */
2341 const char *
2342 device_get_nameunit(device_t dev)
2343 {
2344 	return (dev->nameunit);
2345 }
2346 
2347 /**
2348  * @brief Return the device's unit number.
2349  */
2350 int
2351 device_get_unit(device_t dev)
2352 {
2353 	return (dev->unit);
2354 }
2355 
2356 /**
2357  * @brief Return the device's description string
2358  */
2359 const char *
2360 device_get_desc(device_t dev)
2361 {
2362 	return (dev->desc);
2363 }
2364 
2365 /**
2366  * @brief Return the device's flags
2367  */
2368 uint32_t
2369 device_get_flags(device_t dev)
2370 {
2371 	return (dev->devflags);
2372 }
2373 
2374 struct sysctl_ctx_list *
2375 device_get_sysctl_ctx(device_t dev)
2376 {
2377 	return (&dev->sysctl_ctx);
2378 }
2379 
2380 struct sysctl_oid *
2381 device_get_sysctl_tree(device_t dev)
2382 {
2383 	return (dev->sysctl_tree);
2384 }
2385 
2386 /**
2387  * @brief Print the name of the device followed by a colon and a space
2388  *
2389  * @returns the number of characters printed
2390  */
2391 int
2392 device_print_prettyname(device_t dev)
2393 {
2394 	const char *name = device_get_name(dev);
2395 
2396 	if (name == NULL)
2397 		return (printf("unknown: "));
2398 	return (printf("%s%d: ", name, device_get_unit(dev)));
2399 }
2400 
2401 /**
2402  * @brief Print the name of the device followed by a colon, a space
2403  * and the result of calling vprintf() with the value of @p fmt and
2404  * the following arguments.
2405  *
2406  * @returns the number of characters printed
2407  */
2408 int
2409 device_printf(device_t dev, const char * fmt, ...)
2410 {
2411 	char buf[128];
2412 	struct sbuf sb;
2413 	const char *name;
2414 	va_list ap;
2415 	size_t retval;
2416 
2417 	retval = 0;
2418 
2419 	sbuf_new(&sb, buf, sizeof(buf), SBUF_FIXEDLEN);
2420 	sbuf_set_drain(&sb, sbuf_printf_drain, &retval);
2421 
2422 	name = device_get_name(dev);
2423 
2424 	if (name == NULL)
2425 		sbuf_cat(&sb, "unknown: ");
2426 	else
2427 		sbuf_printf(&sb, "%s%d: ", name, device_get_unit(dev));
2428 
2429 	va_start(ap, fmt);
2430 	sbuf_vprintf(&sb, fmt, ap);
2431 	va_end(ap);
2432 
2433 	sbuf_finish(&sb);
2434 	sbuf_delete(&sb);
2435 
2436 	return (retval);
2437 }
2438 
2439 /**
2440  * @brief Print the name of the device followed by a colon, a space
2441  * and the result of calling log() with the value of @p fmt and
2442  * the following arguments.
2443  *
2444  * @returns the number of characters printed
2445  */
2446 int
2447 device_log(device_t dev, int pri, const char * fmt, ...)
2448 {
2449 	char buf[128];
2450 	struct sbuf sb;
2451 	const char *name;
2452 	va_list ap;
2453 	size_t retval;
2454 
2455 	retval = 0;
2456 
2457 	sbuf_new(&sb, buf, sizeof(buf), SBUF_FIXEDLEN);
2458 
2459 	name = device_get_name(dev);
2460 
2461 	if (name == NULL)
2462 		sbuf_cat(&sb, "unknown: ");
2463 	else
2464 		sbuf_printf(&sb, "%s%d: ", name, device_get_unit(dev));
2465 
2466 	va_start(ap, fmt);
2467 	sbuf_vprintf(&sb, fmt, ap);
2468 	va_end(ap);
2469 
2470 	sbuf_finish(&sb);
2471 
2472 	log(pri, "%.*s", (int) sbuf_len(&sb), sbuf_data(&sb));
2473 	retval = sbuf_len(&sb);
2474 
2475 	sbuf_delete(&sb);
2476 
2477 	return (retval);
2478 }
2479 
2480 /**
2481  * @internal
2482  */
2483 static void
2484 device_set_desc_internal(device_t dev, const char* desc, int copy)
2485 {
2486 	if (dev->desc && (dev->flags & DF_DESCMALLOCED)) {
2487 		free(dev->desc, M_BUS);
2488 		dev->flags &= ~DF_DESCMALLOCED;
2489 		dev->desc = NULL;
2490 	}
2491 
2492 	if (copy && desc) {
2493 		dev->desc = malloc(strlen(desc) + 1, M_BUS, M_NOWAIT);
2494 		if (dev->desc) {
2495 			strcpy(dev->desc, desc);
2496 			dev->flags |= DF_DESCMALLOCED;
2497 		}
2498 	} else {
2499 		/* Avoid a -Wcast-qual warning */
2500 		dev->desc = (char *)(uintptr_t) desc;
2501 	}
2502 
2503 	bus_data_generation_update();
2504 }
2505 
2506 /**
2507  * @brief Set the device's description
2508  *
2509  * The value of @c desc should be a string constant that will not
2510  * change (at least until the description is changed in a subsequent
2511  * call to device_set_desc() or device_set_desc_copy()).
2512  */
2513 void
2514 device_set_desc(device_t dev, const char* desc)
2515 {
2516 	device_set_desc_internal(dev, desc, FALSE);
2517 }
2518 
2519 /**
2520  * @brief Set the device's description
2521  *
2522  * The string pointed to by @c desc is copied. Use this function if
2523  * the device description is generated, (e.g. with sprintf()).
2524  */
2525 void
2526 device_set_desc_copy(device_t dev, const char* desc)
2527 {
2528 	device_set_desc_internal(dev, desc, TRUE);
2529 }
2530 
2531 /**
2532  * @brief Set the device's flags
2533  */
2534 void
2535 device_set_flags(device_t dev, uint32_t flags)
2536 {
2537 	dev->devflags = flags;
2538 }
2539 
2540 /**
2541  * @brief Return the device's softc field
2542  *
2543  * The softc is allocated and zeroed when a driver is attached, based
2544  * on the size field of the driver.
2545  */
2546 void *
2547 device_get_softc(device_t dev)
2548 {
2549 	return (dev->softc);
2550 }
2551 
2552 /**
2553  * @brief Set the device's softc field
2554  *
2555  * Most drivers do not need to use this since the softc is allocated
2556  * automatically when the driver is attached.
2557  */
2558 void
2559 device_set_softc(device_t dev, void *softc)
2560 {
2561 	if (dev->softc && !(dev->flags & DF_EXTERNALSOFTC))
2562 		free(dev->softc, M_BUS_SC);
2563 	dev->softc = softc;
2564 	if (dev->softc)
2565 		dev->flags |= DF_EXTERNALSOFTC;
2566 	else
2567 		dev->flags &= ~DF_EXTERNALSOFTC;
2568 }
2569 
2570 /**
2571  * @brief Free claimed softc
2572  *
2573  * Most drivers do not need to use this since the softc is freed
2574  * automatically when the driver is detached.
2575  */
2576 void
2577 device_free_softc(void *softc)
2578 {
2579 	free(softc, M_BUS_SC);
2580 }
2581 
2582 /**
2583  * @brief Claim softc
2584  *
2585  * This function can be used to let the driver free the automatically
2586  * allocated softc using "device_free_softc()". This function is
2587  * useful when the driver is refcounting the softc and the softc
2588  * cannot be freed when the "device_detach" method is called.
2589  */
2590 void
2591 device_claim_softc(device_t dev)
2592 {
2593 	if (dev->softc)
2594 		dev->flags |= DF_EXTERNALSOFTC;
2595 	else
2596 		dev->flags &= ~DF_EXTERNALSOFTC;
2597 }
2598 
2599 /**
2600  * @brief Get the device's ivars field
2601  *
2602  * The ivars field is used by the parent device to store per-device
2603  * state (e.g. the physical location of the device or a list of
2604  * resources).
2605  */
2606 void *
2607 device_get_ivars(device_t dev)
2608 {
2609 	KASSERT(dev != NULL, ("device_get_ivars(NULL, ...)"));
2610 	return (dev->ivars);
2611 }
2612 
2613 /**
2614  * @brief Set the device's ivars field
2615  */
2616 void
2617 device_set_ivars(device_t dev, void * ivars)
2618 {
2619 	KASSERT(dev != NULL, ("device_set_ivars(NULL, ...)"));
2620 	dev->ivars = ivars;
2621 }
2622 
2623 /**
2624  * @brief Return the device's state
2625  */
2626 device_state_t
2627 device_get_state(device_t dev)
2628 {
2629 	return (dev->state);
2630 }
2631 
2632 /**
2633  * @brief Set the DF_ENABLED flag for the device
2634  */
2635 void
2636 device_enable(device_t dev)
2637 {
2638 	dev->flags |= DF_ENABLED;
2639 }
2640 
2641 /**
2642  * @brief Clear the DF_ENABLED flag for the device
2643  */
2644 void
2645 device_disable(device_t dev)
2646 {
2647 	dev->flags &= ~DF_ENABLED;
2648 }
2649 
2650 /**
2651  * @brief Increment the busy counter for the device
2652  */
2653 void
2654 device_busy(device_t dev)
2655 {
2656 	if (dev->state < DS_ATTACHING)
2657 		panic("device_busy: called for unattached device");
2658 	if (dev->busy == 0 && dev->parent)
2659 		device_busy(dev->parent);
2660 	dev->busy++;
2661 	if (dev->state == DS_ATTACHED)
2662 		dev->state = DS_BUSY;
2663 }
2664 
2665 /**
2666  * @brief Decrement the busy counter for the device
2667  */
2668 void
2669 device_unbusy(device_t dev)
2670 {
2671 	if (dev->busy != 0 && dev->state != DS_BUSY &&
2672 	    dev->state != DS_ATTACHING)
2673 		panic("device_unbusy: called for non-busy device %s",
2674 		    device_get_nameunit(dev));
2675 	dev->busy--;
2676 	if (dev->busy == 0) {
2677 		if (dev->parent)
2678 			device_unbusy(dev->parent);
2679 		if (dev->state == DS_BUSY)
2680 			dev->state = DS_ATTACHED;
2681 	}
2682 }
2683 
2684 /**
2685  * @brief Set the DF_QUIET flag for the device
2686  */
2687 void
2688 device_quiet(device_t dev)
2689 {
2690 	dev->flags |= DF_QUIET;
2691 }
2692 
2693 /**
2694  * @brief Set the DF_QUIET_CHILDREN flag for the device
2695  */
2696 void
2697 device_quiet_children(device_t dev)
2698 {
2699 	dev->flags |= DF_QUIET_CHILDREN;
2700 }
2701 
2702 /**
2703  * @brief Clear the DF_QUIET flag for the device
2704  */
2705 void
2706 device_verbose(device_t dev)
2707 {
2708 	dev->flags &= ~DF_QUIET;
2709 }
2710 
2711 /**
2712  * @brief Return non-zero if the DF_QUIET_CHIDLREN flag is set on the device
2713  */
2714 int
2715 device_has_quiet_children(device_t dev)
2716 {
2717 	return ((dev->flags & DF_QUIET_CHILDREN) != 0);
2718 }
2719 
2720 /**
2721  * @brief Return non-zero if the DF_QUIET flag is set on the device
2722  */
2723 int
2724 device_is_quiet(device_t dev)
2725 {
2726 	return ((dev->flags & DF_QUIET) != 0);
2727 }
2728 
2729 /**
2730  * @brief Return non-zero if the DF_ENABLED flag is set on the device
2731  */
2732 int
2733 device_is_enabled(device_t dev)
2734 {
2735 	return ((dev->flags & DF_ENABLED) != 0);
2736 }
2737 
2738 /**
2739  * @brief Return non-zero if the device was successfully probed
2740  */
2741 int
2742 device_is_alive(device_t dev)
2743 {
2744 	return (dev->state >= DS_ALIVE);
2745 }
2746 
2747 /**
2748  * @brief Return non-zero if the device currently has a driver
2749  * attached to it
2750  */
2751 int
2752 device_is_attached(device_t dev)
2753 {
2754 	return (dev->state >= DS_ATTACHED);
2755 }
2756 
2757 /**
2758  * @brief Return non-zero if the device is currently suspended.
2759  */
2760 int
2761 device_is_suspended(device_t dev)
2762 {
2763 	return ((dev->flags & DF_SUSPENDED) != 0);
2764 }
2765 
2766 /**
2767  * @brief Set the devclass of a device
2768  * @see devclass_add_device().
2769  */
2770 int
2771 device_set_devclass(device_t dev, const char *classname)
2772 {
2773 	devclass_t dc;
2774 	int error;
2775 
2776 	if (!classname) {
2777 		if (dev->devclass)
2778 			devclass_delete_device(dev->devclass, dev);
2779 		return (0);
2780 	}
2781 
2782 	if (dev->devclass) {
2783 		printf("device_set_devclass: device class already set\n");
2784 		return (EINVAL);
2785 	}
2786 
2787 	dc = devclass_find_internal(classname, NULL, TRUE);
2788 	if (!dc)
2789 		return (ENOMEM);
2790 
2791 	error = devclass_add_device(dc, dev);
2792 
2793 	bus_data_generation_update();
2794 	return (error);
2795 }
2796 
2797 /**
2798  * @brief Set the devclass of a device and mark the devclass fixed.
2799  * @see device_set_devclass()
2800  */
2801 int
2802 device_set_devclass_fixed(device_t dev, const char *classname)
2803 {
2804 	int error;
2805 
2806 	if (classname == NULL)
2807 		return (EINVAL);
2808 
2809 	error = device_set_devclass(dev, classname);
2810 	if (error)
2811 		return (error);
2812 	dev->flags |= DF_FIXEDCLASS;
2813 	return (0);
2814 }
2815 
2816 /**
2817  * @brief Query the device to determine if it's of a fixed devclass
2818  * @see device_set_devclass_fixed()
2819  */
2820 bool
2821 device_is_devclass_fixed(device_t dev)
2822 {
2823 	return ((dev->flags & DF_FIXEDCLASS) != 0);
2824 }
2825 
2826 /**
2827  * @brief Set the driver of a device
2828  *
2829  * @retval 0		success
2830  * @retval EBUSY	the device already has a driver attached
2831  * @retval ENOMEM	a memory allocation failure occurred
2832  */
2833 int
2834 device_set_driver(device_t dev, driver_t *driver)
2835 {
2836 	int domain;
2837 	struct domainset *policy;
2838 
2839 	if (dev->state >= DS_ATTACHED)
2840 		return (EBUSY);
2841 
2842 	if (dev->driver == driver)
2843 		return (0);
2844 
2845 	if (dev->softc && !(dev->flags & DF_EXTERNALSOFTC)) {
2846 		free(dev->softc, M_BUS_SC);
2847 		dev->softc = NULL;
2848 	}
2849 	device_set_desc(dev, NULL);
2850 	kobj_delete((kobj_t) dev, NULL);
2851 	dev->driver = driver;
2852 	if (driver) {
2853 		kobj_init((kobj_t) dev, (kobj_class_t) driver);
2854 		if (!(dev->flags & DF_EXTERNALSOFTC) && driver->size > 0) {
2855 			if (bus_get_domain(dev, &domain) == 0)
2856 				policy = DOMAINSET_PREF(domain);
2857 			else
2858 				policy = DOMAINSET_RR();
2859 			dev->softc = malloc_domainset(driver->size, M_BUS_SC,
2860 			    policy, M_NOWAIT | M_ZERO);
2861 			if (!dev->softc) {
2862 				kobj_delete((kobj_t) dev, NULL);
2863 				kobj_init((kobj_t) dev, &null_class);
2864 				dev->driver = NULL;
2865 				return (ENOMEM);
2866 			}
2867 		}
2868 	} else {
2869 		kobj_init((kobj_t) dev, &null_class);
2870 	}
2871 
2872 	bus_data_generation_update();
2873 	return (0);
2874 }
2875 
2876 /**
2877  * @brief Probe a device, and return this status.
2878  *
2879  * This function is the core of the device autoconfiguration
2880  * system. Its purpose is to select a suitable driver for a device and
2881  * then call that driver to initialise the hardware appropriately. The
2882  * driver is selected by calling the DEVICE_PROBE() method of a set of
2883  * candidate drivers and then choosing the driver which returned the
2884  * best value. This driver is then attached to the device using
2885  * device_attach().
2886  *
2887  * The set of suitable drivers is taken from the list of drivers in
2888  * the parent device's devclass. If the device was originally created
2889  * with a specific class name (see device_add_child()), only drivers
2890  * with that name are probed, otherwise all drivers in the devclass
2891  * are probed. If no drivers return successful probe values in the
2892  * parent devclass, the search continues in the parent of that
2893  * devclass (see devclass_get_parent()) if any.
2894  *
2895  * @param dev		the device to initialise
2896  *
2897  * @retval 0		success
2898  * @retval ENXIO	no driver was found
2899  * @retval ENOMEM	memory allocation failure
2900  * @retval non-zero	some other unix error code
2901  * @retval -1		Device already attached
2902  */
2903 int
2904 device_probe(device_t dev)
2905 {
2906 	int error;
2907 
2908 	GIANT_REQUIRED;
2909 
2910 	if (dev->state >= DS_ALIVE && (dev->flags & DF_REBID) == 0)
2911 		return (-1);
2912 
2913 	if (!(dev->flags & DF_ENABLED)) {
2914 		if (bootverbose && device_get_name(dev) != NULL) {
2915 			device_print_prettyname(dev);
2916 			printf("not probed (disabled)\n");
2917 		}
2918 		return (-1);
2919 	}
2920 	if ((error = device_probe_child(dev->parent, dev)) != 0) {
2921 		if (bus_current_pass == BUS_PASS_DEFAULT &&
2922 		    !(dev->flags & DF_DONENOMATCH)) {
2923 			BUS_PROBE_NOMATCH(dev->parent, dev);
2924 			devnomatch(dev);
2925 			dev->flags |= DF_DONENOMATCH;
2926 		}
2927 		return (error);
2928 	}
2929 	return (0);
2930 }
2931 
2932 /**
2933  * @brief Probe a device and attach a driver if possible
2934  *
2935  * calls device_probe() and attaches if that was successful.
2936  */
2937 int
2938 device_probe_and_attach(device_t dev)
2939 {
2940 	int error;
2941 
2942 	GIANT_REQUIRED;
2943 
2944 	error = device_probe(dev);
2945 	if (error == -1)
2946 		return (0);
2947 	else if (error != 0)
2948 		return (error);
2949 
2950 	CURVNET_SET_QUIET(vnet0);
2951 	error = device_attach(dev);
2952 	CURVNET_RESTORE();
2953 	return error;
2954 }
2955 
2956 /**
2957  * @brief Attach a device driver to a device
2958  *
2959  * This function is a wrapper around the DEVICE_ATTACH() driver
2960  * method. In addition to calling DEVICE_ATTACH(), it initialises the
2961  * device's sysctl tree, optionally prints a description of the device
2962  * and queues a notification event for user-based device management
2963  * services.
2964  *
2965  * Normally this function is only called internally from
2966  * device_probe_and_attach().
2967  *
2968  * @param dev		the device to initialise
2969  *
2970  * @retval 0		success
2971  * @retval ENXIO	no driver was found
2972  * @retval ENOMEM	memory allocation failure
2973  * @retval non-zero	some other unix error code
2974  */
2975 int
2976 device_attach(device_t dev)
2977 {
2978 	uint64_t attachtime;
2979 	uint16_t attachentropy;
2980 	int error;
2981 
2982 	if (resource_disabled(dev->driver->name, dev->unit)) {
2983 		device_disable(dev);
2984 		if (bootverbose)
2985 			 device_printf(dev, "disabled via hints entry\n");
2986 		return (ENXIO);
2987 	}
2988 
2989 	device_sysctl_init(dev);
2990 	if (!device_is_quiet(dev))
2991 		device_print_child(dev->parent, dev);
2992 	attachtime = get_cyclecount();
2993 	dev->state = DS_ATTACHING;
2994 	if ((error = DEVICE_ATTACH(dev)) != 0) {
2995 		printf("device_attach: %s%d attach returned %d\n",
2996 		    dev->driver->name, dev->unit, error);
2997 		if (!(dev->flags & DF_FIXEDCLASS))
2998 			devclass_delete_device(dev->devclass, dev);
2999 		(void)device_set_driver(dev, NULL);
3000 		device_sysctl_fini(dev);
3001 		KASSERT(dev->busy == 0, ("attach failed but busy"));
3002 		dev->state = DS_NOTPRESENT;
3003 		return (error);
3004 	}
3005 	dev->flags |= DF_ATTACHED_ONCE;
3006 	/* We only need the low bits of this time, but ranges from tens to thousands
3007 	 * have been seen, so keep 2 bytes' worth.
3008 	 */
3009 	attachentropy = (uint16_t)(get_cyclecount() - attachtime);
3010 	random_harvest_direct(&attachentropy, sizeof(attachentropy), RANDOM_ATTACH);
3011 	device_sysctl_update(dev);
3012 	if (dev->busy)
3013 		dev->state = DS_BUSY;
3014 	else
3015 		dev->state = DS_ATTACHED;
3016 	dev->flags &= ~DF_DONENOMATCH;
3017 	EVENTHANDLER_DIRECT_INVOKE(device_attach, dev);
3018 	devadded(dev);
3019 	return (0);
3020 }
3021 
3022 /**
3023  * @brief Detach a driver from a device
3024  *
3025  * This function is a wrapper around the DEVICE_DETACH() driver
3026  * method. If the call to DEVICE_DETACH() succeeds, it calls
3027  * BUS_CHILD_DETACHED() for the parent of @p dev, queues a
3028  * notification event for user-based device management services and
3029  * cleans up the device's sysctl tree.
3030  *
3031  * @param dev		the device to un-initialise
3032  *
3033  * @retval 0		success
3034  * @retval ENXIO	no driver was found
3035  * @retval ENOMEM	memory allocation failure
3036  * @retval non-zero	some other unix error code
3037  */
3038 int
3039 device_detach(device_t dev)
3040 {
3041 	int error;
3042 
3043 	GIANT_REQUIRED;
3044 
3045 	PDEBUG(("%s", DEVICENAME(dev)));
3046 	if (dev->state == DS_BUSY)
3047 		return (EBUSY);
3048 	if (dev->state == DS_ATTACHING) {
3049 		device_printf(dev, "device in attaching state! Deferring detach.\n");
3050 		return (EBUSY);
3051 	}
3052 	if (dev->state != DS_ATTACHED)
3053 		return (0);
3054 
3055 	EVENTHANDLER_DIRECT_INVOKE(device_detach, dev, EVHDEV_DETACH_BEGIN);
3056 	if ((error = DEVICE_DETACH(dev)) != 0) {
3057 		EVENTHANDLER_DIRECT_INVOKE(device_detach, dev,
3058 		    EVHDEV_DETACH_FAILED);
3059 		return (error);
3060 	} else {
3061 		EVENTHANDLER_DIRECT_INVOKE(device_detach, dev,
3062 		    EVHDEV_DETACH_COMPLETE);
3063 	}
3064 	devremoved(dev);
3065 	if (!device_is_quiet(dev))
3066 		device_printf(dev, "detached\n");
3067 	if (dev->parent)
3068 		BUS_CHILD_DETACHED(dev->parent, dev);
3069 
3070 	if (!(dev->flags & DF_FIXEDCLASS))
3071 		devclass_delete_device(dev->devclass, dev);
3072 
3073 	device_verbose(dev);
3074 	dev->state = DS_NOTPRESENT;
3075 	(void)device_set_driver(dev, NULL);
3076 	device_sysctl_fini(dev);
3077 
3078 	return (0);
3079 }
3080 
3081 /**
3082  * @brief Tells a driver to quiesce itself.
3083  *
3084  * This function is a wrapper around the DEVICE_QUIESCE() driver
3085  * method. If the call to DEVICE_QUIESCE() succeeds.
3086  *
3087  * @param dev		the device to quiesce
3088  *
3089  * @retval 0		success
3090  * @retval ENXIO	no driver was found
3091  * @retval ENOMEM	memory allocation failure
3092  * @retval non-zero	some other unix error code
3093  */
3094 int
3095 device_quiesce(device_t dev)
3096 {
3097 	PDEBUG(("%s", DEVICENAME(dev)));
3098 	if (dev->state == DS_BUSY)
3099 		return (EBUSY);
3100 	if (dev->state != DS_ATTACHED)
3101 		return (0);
3102 
3103 	return (DEVICE_QUIESCE(dev));
3104 }
3105 
3106 /**
3107  * @brief Notify a device of system shutdown
3108  *
3109  * This function calls the DEVICE_SHUTDOWN() driver method if the
3110  * device currently has an attached driver.
3111  *
3112  * @returns the value returned by DEVICE_SHUTDOWN()
3113  */
3114 int
3115 device_shutdown(device_t dev)
3116 {
3117 	if (dev->state < DS_ATTACHED)
3118 		return (0);
3119 	return (DEVICE_SHUTDOWN(dev));
3120 }
3121 
3122 /**
3123  * @brief Set the unit number of a device
3124  *
3125  * This function can be used to override the unit number used for a
3126  * device (e.g. to wire a device to a pre-configured unit number).
3127  */
3128 int
3129 device_set_unit(device_t dev, int unit)
3130 {
3131 	devclass_t dc;
3132 	int err;
3133 
3134 	dc = device_get_devclass(dev);
3135 	if (unit < dc->maxunit && dc->devices[unit])
3136 		return (EBUSY);
3137 	err = devclass_delete_device(dc, dev);
3138 	if (err)
3139 		return (err);
3140 	dev->unit = unit;
3141 	err = devclass_add_device(dc, dev);
3142 	if (err)
3143 		return (err);
3144 
3145 	bus_data_generation_update();
3146 	return (0);
3147 }
3148 
3149 /*======================================*/
3150 /*
3151  * Some useful method implementations to make life easier for bus drivers.
3152  */
3153 
3154 void
3155 resource_init_map_request_impl(struct resource_map_request *args, size_t sz)
3156 {
3157 	bzero(args, sz);
3158 	args->size = sz;
3159 	args->memattr = VM_MEMATTR_DEVICE;
3160 }
3161 
3162 /**
3163  * @brief Initialise a resource list.
3164  *
3165  * @param rl		the resource list to initialise
3166  */
3167 void
3168 resource_list_init(struct resource_list *rl)
3169 {
3170 	STAILQ_INIT(rl);
3171 }
3172 
3173 /**
3174  * @brief Reclaim memory used by a resource list.
3175  *
3176  * This function frees the memory for all resource entries on the list
3177  * (if any).
3178  *
3179  * @param rl		the resource list to free
3180  */
3181 void
3182 resource_list_free(struct resource_list *rl)
3183 {
3184 	struct resource_list_entry *rle;
3185 
3186 	while ((rle = STAILQ_FIRST(rl)) != NULL) {
3187 		if (rle->res)
3188 			panic("resource_list_free: resource entry is busy");
3189 		STAILQ_REMOVE_HEAD(rl, link);
3190 		free(rle, M_BUS);
3191 	}
3192 }
3193 
3194 /**
3195  * @brief Add a resource entry.
3196  *
3197  * This function adds a resource entry using the given @p type, @p
3198  * start, @p end and @p count values. A rid value is chosen by
3199  * searching sequentially for the first unused rid starting at zero.
3200  *
3201  * @param rl		the resource list to edit
3202  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
3203  * @param start		the start address of the resource
3204  * @param end		the end address of the resource
3205  * @param count		XXX end-start+1
3206  */
3207 int
3208 resource_list_add_next(struct resource_list *rl, int type, rman_res_t start,
3209     rman_res_t end, rman_res_t count)
3210 {
3211 	int rid;
3212 
3213 	rid = 0;
3214 	while (resource_list_find(rl, type, rid) != NULL)
3215 		rid++;
3216 	resource_list_add(rl, type, rid, start, end, count);
3217 	return (rid);
3218 }
3219 
3220 /**
3221  * @brief Add or modify a resource entry.
3222  *
3223  * If an existing entry exists with the same type and rid, it will be
3224  * modified using the given values of @p start, @p end and @p
3225  * count. If no entry exists, a new one will be created using the
3226  * given values.  The resource list entry that matches is then returned.
3227  *
3228  * @param rl		the resource list to edit
3229  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
3230  * @param rid		the resource identifier
3231  * @param start		the start address of the resource
3232  * @param end		the end address of the resource
3233  * @param count		XXX end-start+1
3234  */
3235 struct resource_list_entry *
3236 resource_list_add(struct resource_list *rl, int type, int rid,
3237     rman_res_t start, rman_res_t end, rman_res_t count)
3238 {
3239 	struct resource_list_entry *rle;
3240 
3241 	rle = resource_list_find(rl, type, rid);
3242 	if (!rle) {
3243 		rle = malloc(sizeof(struct resource_list_entry), M_BUS,
3244 		    M_NOWAIT);
3245 		if (!rle)
3246 			panic("resource_list_add: can't record entry");
3247 		STAILQ_INSERT_TAIL(rl, rle, link);
3248 		rle->type = type;
3249 		rle->rid = rid;
3250 		rle->res = NULL;
3251 		rle->flags = 0;
3252 	}
3253 
3254 	if (rle->res)
3255 		panic("resource_list_add: resource entry is busy");
3256 
3257 	rle->start = start;
3258 	rle->end = end;
3259 	rle->count = count;
3260 	return (rle);
3261 }
3262 
3263 /**
3264  * @brief Determine if a resource entry is busy.
3265  *
3266  * Returns true if a resource entry is busy meaning that it has an
3267  * associated resource that is not an unallocated "reserved" resource.
3268  *
3269  * @param rl		the resource list to search
3270  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
3271  * @param rid		the resource identifier
3272  *
3273  * @returns Non-zero if the entry is busy, zero otherwise.
3274  */
3275 int
3276 resource_list_busy(struct resource_list *rl, int type, int rid)
3277 {
3278 	struct resource_list_entry *rle;
3279 
3280 	rle = resource_list_find(rl, type, rid);
3281 	if (rle == NULL || rle->res == NULL)
3282 		return (0);
3283 	if ((rle->flags & (RLE_RESERVED | RLE_ALLOCATED)) == RLE_RESERVED) {
3284 		KASSERT(!(rman_get_flags(rle->res) & RF_ACTIVE),
3285 		    ("reserved resource is active"));
3286 		return (0);
3287 	}
3288 	return (1);
3289 }
3290 
3291 /**
3292  * @brief Determine if a resource entry is reserved.
3293  *
3294  * Returns true if a resource entry is reserved meaning that it has an
3295  * associated "reserved" resource.  The resource can either be
3296  * allocated or unallocated.
3297  *
3298  * @param rl		the resource list to search
3299  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
3300  * @param rid		the resource identifier
3301  *
3302  * @returns Non-zero if the entry is reserved, zero otherwise.
3303  */
3304 int
3305 resource_list_reserved(struct resource_list *rl, int type, int rid)
3306 {
3307 	struct resource_list_entry *rle;
3308 
3309 	rle = resource_list_find(rl, type, rid);
3310 	if (rle != NULL && rle->flags & RLE_RESERVED)
3311 		return (1);
3312 	return (0);
3313 }
3314 
3315 /**
3316  * @brief Find a resource entry by type and rid.
3317  *
3318  * @param rl		the resource list to search
3319  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
3320  * @param rid		the resource identifier
3321  *
3322  * @returns the resource entry pointer or NULL if there is no such
3323  * entry.
3324  */
3325 struct resource_list_entry *
3326 resource_list_find(struct resource_list *rl, int type, int rid)
3327 {
3328 	struct resource_list_entry *rle;
3329 
3330 	STAILQ_FOREACH(rle, rl, link) {
3331 		if (rle->type == type && rle->rid == rid)
3332 			return (rle);
3333 	}
3334 	return (NULL);
3335 }
3336 
3337 /**
3338  * @brief Delete a resource entry.
3339  *
3340  * @param rl		the resource list to edit
3341  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
3342  * @param rid		the resource identifier
3343  */
3344 void
3345 resource_list_delete(struct resource_list *rl, int type, int rid)
3346 {
3347 	struct resource_list_entry *rle = resource_list_find(rl, type, rid);
3348 
3349 	if (rle) {
3350 		if (rle->res != NULL)
3351 			panic("resource_list_delete: resource has not been released");
3352 		STAILQ_REMOVE(rl, rle, resource_list_entry, link);
3353 		free(rle, M_BUS);
3354 	}
3355 }
3356 
3357 /**
3358  * @brief Allocate a reserved resource
3359  *
3360  * This can be used by buses to force the allocation of resources
3361  * that are always active in the system even if they are not allocated
3362  * by a driver (e.g. PCI BARs).  This function is usually called when
3363  * adding a new child to the bus.  The resource is allocated from the
3364  * parent bus when it is reserved.  The resource list entry is marked
3365  * with RLE_RESERVED to note that it is a reserved resource.
3366  *
3367  * Subsequent attempts to allocate the resource with
3368  * resource_list_alloc() will succeed the first time and will set
3369  * RLE_ALLOCATED to note that it has been allocated.  When a reserved
3370  * resource that has been allocated is released with
3371  * resource_list_release() the resource RLE_ALLOCATED is cleared, but
3372  * the actual resource remains allocated.  The resource can be released to
3373  * the parent bus by calling resource_list_unreserve().
3374  *
3375  * @param rl		the resource list to allocate from
3376  * @param bus		the parent device of @p child
3377  * @param child		the device for which the resource is being reserved
3378  * @param type		the type of resource to allocate
3379  * @param rid		a pointer to the resource identifier
3380  * @param start		hint at the start of the resource range - pass
3381  *			@c 0 for any start address
3382  * @param end		hint at the end of the resource range - pass
3383  *			@c ~0 for any end address
3384  * @param count		hint at the size of range required - pass @c 1
3385  *			for any size
3386  * @param flags		any extra flags to control the resource
3387  *			allocation - see @c RF_XXX flags in
3388  *			<sys/rman.h> for details
3389  *
3390  * @returns		the resource which was allocated or @c NULL if no
3391  *			resource could be allocated
3392  */
3393 struct resource *
3394 resource_list_reserve(struct resource_list *rl, device_t bus, device_t child,
3395     int type, int *rid, rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
3396 {
3397 	struct resource_list_entry *rle = NULL;
3398 	int passthrough = (device_get_parent(child) != bus);
3399 	struct resource *r;
3400 
3401 	if (passthrough)
3402 		panic(
3403     "resource_list_reserve() should only be called for direct children");
3404 	if (flags & RF_ACTIVE)
3405 		panic(
3406     "resource_list_reserve() should only reserve inactive resources");
3407 
3408 	r = resource_list_alloc(rl, bus, child, type, rid, start, end, count,
3409 	    flags);
3410 	if (r != NULL) {
3411 		rle = resource_list_find(rl, type, *rid);
3412 		rle->flags |= RLE_RESERVED;
3413 	}
3414 	return (r);
3415 }
3416 
3417 /**
3418  * @brief Helper function for implementing BUS_ALLOC_RESOURCE()
3419  *
3420  * Implement BUS_ALLOC_RESOURCE() by looking up a resource from the list
3421  * and passing the allocation up to the parent of @p bus. This assumes
3422  * that the first entry of @c device_get_ivars(child) is a struct
3423  * resource_list. This also handles 'passthrough' allocations where a
3424  * child is a remote descendant of bus by passing the allocation up to
3425  * the parent of bus.
3426  *
3427  * Typically, a bus driver would store a list of child resources
3428  * somewhere in the child device's ivars (see device_get_ivars()) and
3429  * its implementation of BUS_ALLOC_RESOURCE() would find that list and
3430  * then call resource_list_alloc() to perform the allocation.
3431  *
3432  * @param rl		the resource list to allocate from
3433  * @param bus		the parent device of @p child
3434  * @param child		the device which is requesting an allocation
3435  * @param type		the type of resource to allocate
3436  * @param rid		a pointer to the resource identifier
3437  * @param start		hint at the start of the resource range - pass
3438  *			@c 0 for any start address
3439  * @param end		hint at the end of the resource range - pass
3440  *			@c ~0 for any end address
3441  * @param count		hint at the size of range required - pass @c 1
3442  *			for any size
3443  * @param flags		any extra flags to control the resource
3444  *			allocation - see @c RF_XXX flags in
3445  *			<sys/rman.h> for details
3446  *
3447  * @returns		the resource which was allocated or @c NULL if no
3448  *			resource could be allocated
3449  */
3450 struct resource *
3451 resource_list_alloc(struct resource_list *rl, device_t bus, device_t child,
3452     int type, int *rid, rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
3453 {
3454 	struct resource_list_entry *rle = NULL;
3455 	int passthrough = (device_get_parent(child) != bus);
3456 	int isdefault = RMAN_IS_DEFAULT_RANGE(start, end);
3457 
3458 	if (passthrough) {
3459 		return (BUS_ALLOC_RESOURCE(device_get_parent(bus), child,
3460 		    type, rid, start, end, count, flags));
3461 	}
3462 
3463 	rle = resource_list_find(rl, type, *rid);
3464 
3465 	if (!rle)
3466 		return (NULL);		/* no resource of that type/rid */
3467 
3468 	if (rle->res) {
3469 		if (rle->flags & RLE_RESERVED) {
3470 			if (rle->flags & RLE_ALLOCATED)
3471 				return (NULL);
3472 			if ((flags & RF_ACTIVE) &&
3473 			    bus_activate_resource(child, type, *rid,
3474 			    rle->res) != 0)
3475 				return (NULL);
3476 			rle->flags |= RLE_ALLOCATED;
3477 			return (rle->res);
3478 		}
3479 		device_printf(bus,
3480 		    "resource entry %#x type %d for child %s is busy\n", *rid,
3481 		    type, device_get_nameunit(child));
3482 		return (NULL);
3483 	}
3484 
3485 	if (isdefault) {
3486 		start = rle->start;
3487 		count = ulmax(count, rle->count);
3488 		end = ulmax(rle->end, start + count - 1);
3489 	}
3490 
3491 	rle->res = BUS_ALLOC_RESOURCE(device_get_parent(bus), child,
3492 	    type, rid, start, end, count, flags);
3493 
3494 	/*
3495 	 * Record the new range.
3496 	 */
3497 	if (rle->res) {
3498 		rle->start = rman_get_start(rle->res);
3499 		rle->end = rman_get_end(rle->res);
3500 		rle->count = count;
3501 	}
3502 
3503 	return (rle->res);
3504 }
3505 
3506 /**
3507  * @brief Helper function for implementing BUS_RELEASE_RESOURCE()
3508  *
3509  * Implement BUS_RELEASE_RESOURCE() using a resource list. Normally
3510  * used with resource_list_alloc().
3511  *
3512  * @param rl		the resource list which was allocated from
3513  * @param bus		the parent device of @p child
3514  * @param child		the device which is requesting a release
3515  * @param type		the type of resource to release
3516  * @param rid		the resource identifier
3517  * @param res		the resource to release
3518  *
3519  * @retval 0		success
3520  * @retval non-zero	a standard unix error code indicating what
3521  *			error condition prevented the operation
3522  */
3523 int
3524 resource_list_release(struct resource_list *rl, device_t bus, device_t child,
3525     int type, int rid, struct resource *res)
3526 {
3527 	struct resource_list_entry *rle = NULL;
3528 	int passthrough = (device_get_parent(child) != bus);
3529 	int error;
3530 
3531 	if (passthrough) {
3532 		return (BUS_RELEASE_RESOURCE(device_get_parent(bus), child,
3533 		    type, rid, res));
3534 	}
3535 
3536 	rle = resource_list_find(rl, type, rid);
3537 
3538 	if (!rle)
3539 		panic("resource_list_release: can't find resource");
3540 	if (!rle->res)
3541 		panic("resource_list_release: resource entry is not busy");
3542 	if (rle->flags & RLE_RESERVED) {
3543 		if (rle->flags & RLE_ALLOCATED) {
3544 			if (rman_get_flags(res) & RF_ACTIVE) {
3545 				error = bus_deactivate_resource(child, type,
3546 				    rid, res);
3547 				if (error)
3548 					return (error);
3549 			}
3550 			rle->flags &= ~RLE_ALLOCATED;
3551 			return (0);
3552 		}
3553 		return (EINVAL);
3554 	}
3555 
3556 	error = BUS_RELEASE_RESOURCE(device_get_parent(bus), child,
3557 	    type, rid, res);
3558 	if (error)
3559 		return (error);
3560 
3561 	rle->res = NULL;
3562 	return (0);
3563 }
3564 
3565 /**
3566  * @brief Release all active resources of a given type
3567  *
3568  * Release all active resources of a specified type.  This is intended
3569  * to be used to cleanup resources leaked by a driver after detach or
3570  * a failed attach.
3571  *
3572  * @param rl		the resource list which was allocated from
3573  * @param bus		the parent device of @p child
3574  * @param child		the device whose active resources are being released
3575  * @param type		the type of resources to release
3576  *
3577  * @retval 0		success
3578  * @retval EBUSY	at least one resource was active
3579  */
3580 int
3581 resource_list_release_active(struct resource_list *rl, device_t bus,
3582     device_t child, int type)
3583 {
3584 	struct resource_list_entry *rle;
3585 	int error, retval;
3586 
3587 	retval = 0;
3588 	STAILQ_FOREACH(rle, rl, link) {
3589 		if (rle->type != type)
3590 			continue;
3591 		if (rle->res == NULL)
3592 			continue;
3593 		if ((rle->flags & (RLE_RESERVED | RLE_ALLOCATED)) ==
3594 		    RLE_RESERVED)
3595 			continue;
3596 		retval = EBUSY;
3597 		error = resource_list_release(rl, bus, child, type,
3598 		    rman_get_rid(rle->res), rle->res);
3599 		if (error != 0)
3600 			device_printf(bus,
3601 			    "Failed to release active resource: %d\n", error);
3602 	}
3603 	return (retval);
3604 }
3605 
3606 /**
3607  * @brief Fully release a reserved resource
3608  *
3609  * Fully releases a resource reserved via resource_list_reserve().
3610  *
3611  * @param rl		the resource list which was allocated from
3612  * @param bus		the parent device of @p child
3613  * @param child		the device whose reserved resource is being released
3614  * @param type		the type of resource to release
3615  * @param rid		the resource identifier
3616  * @param res		the resource to release
3617  *
3618  * @retval 0		success
3619  * @retval non-zero	a standard unix error code indicating what
3620  *			error condition prevented the operation
3621  */
3622 int
3623 resource_list_unreserve(struct resource_list *rl, device_t bus, device_t child,
3624     int type, int rid)
3625 {
3626 	struct resource_list_entry *rle = NULL;
3627 	int passthrough = (device_get_parent(child) != bus);
3628 
3629 	if (passthrough)
3630 		panic(
3631     "resource_list_unreserve() should only be called for direct children");
3632 
3633 	rle = resource_list_find(rl, type, rid);
3634 
3635 	if (!rle)
3636 		panic("resource_list_unreserve: can't find resource");
3637 	if (!(rle->flags & RLE_RESERVED))
3638 		return (EINVAL);
3639 	if (rle->flags & RLE_ALLOCATED)
3640 		return (EBUSY);
3641 	rle->flags &= ~RLE_RESERVED;
3642 	return (resource_list_release(rl, bus, child, type, rid, rle->res));
3643 }
3644 
3645 /**
3646  * @brief Print a description of resources in a resource list
3647  *
3648  * Print all resources of a specified type, for use in BUS_PRINT_CHILD().
3649  * The name is printed if at least one resource of the given type is available.
3650  * The format is used to print resource start and end.
3651  *
3652  * @param rl		the resource list to print
3653  * @param name		the name of @p type, e.g. @c "memory"
3654  * @param type		type type of resource entry to print
3655  * @param format	printf(9) format string to print resource
3656  *			start and end values
3657  *
3658  * @returns		the number of characters printed
3659  */
3660 int
3661 resource_list_print_type(struct resource_list *rl, const char *name, int type,
3662     const char *format)
3663 {
3664 	struct resource_list_entry *rle;
3665 	int printed, retval;
3666 
3667 	printed = 0;
3668 	retval = 0;
3669 	/* Yes, this is kinda cheating */
3670 	STAILQ_FOREACH(rle, rl, link) {
3671 		if (rle->type == type) {
3672 			if (printed == 0)
3673 				retval += printf(" %s ", name);
3674 			else
3675 				retval += printf(",");
3676 			printed++;
3677 			retval += printf(format, rle->start);
3678 			if (rle->count > 1) {
3679 				retval += printf("-");
3680 				retval += printf(format, rle->start +
3681 						 rle->count - 1);
3682 			}
3683 		}
3684 	}
3685 	return (retval);
3686 }
3687 
3688 /**
3689  * @brief Releases all the resources in a list.
3690  *
3691  * @param rl		The resource list to purge.
3692  *
3693  * @returns		nothing
3694  */
3695 void
3696 resource_list_purge(struct resource_list *rl)
3697 {
3698 	struct resource_list_entry *rle;
3699 
3700 	while ((rle = STAILQ_FIRST(rl)) != NULL) {
3701 		if (rle->res)
3702 			bus_release_resource(rman_get_device(rle->res),
3703 			    rle->type, rle->rid, rle->res);
3704 		STAILQ_REMOVE_HEAD(rl, link);
3705 		free(rle, M_BUS);
3706 	}
3707 }
3708 
3709 device_t
3710 bus_generic_add_child(device_t dev, u_int order, const char *name, int unit)
3711 {
3712 	return (device_add_child_ordered(dev, order, name, unit));
3713 }
3714 
3715 /**
3716  * @brief Helper function for implementing DEVICE_PROBE()
3717  *
3718  * This function can be used to help implement the DEVICE_PROBE() for
3719  * a bus (i.e. a device which has other devices attached to it). It
3720  * calls the DEVICE_IDENTIFY() method of each driver in the device's
3721  * devclass.
3722  */
3723 int
3724 bus_generic_probe(device_t dev)
3725 {
3726 	devclass_t dc = dev->devclass;
3727 	driverlink_t dl;
3728 
3729 	TAILQ_FOREACH(dl, &dc->drivers, link) {
3730 		/*
3731 		 * If this driver's pass is too high, then ignore it.
3732 		 * For most drivers in the default pass, this will
3733 		 * never be true.  For early-pass drivers they will
3734 		 * only call the identify routines of eligible drivers
3735 		 * when this routine is called.  Drivers for later
3736 		 * passes should have their identify routines called
3737 		 * on early-pass buses during BUS_NEW_PASS().
3738 		 */
3739 		if (dl->pass > bus_current_pass)
3740 			continue;
3741 		DEVICE_IDENTIFY(dl->driver, dev);
3742 	}
3743 
3744 	return (0);
3745 }
3746 
3747 /**
3748  * @brief Helper function for implementing DEVICE_ATTACH()
3749  *
3750  * This function can be used to help implement the DEVICE_ATTACH() for
3751  * a bus. It calls device_probe_and_attach() for each of the device's
3752  * children.
3753  */
3754 int
3755 bus_generic_attach(device_t dev)
3756 {
3757 	device_t child;
3758 
3759 	TAILQ_FOREACH(child, &dev->children, link) {
3760 		device_probe_and_attach(child);
3761 	}
3762 
3763 	return (0);
3764 }
3765 
3766 /**
3767  * @brief Helper function for delaying attaching children
3768  *
3769  * Many buses can't run transactions on the bus which children need to probe and
3770  * attach until after interrupts and/or timers are running.  This function
3771  * delays their attach until interrupts and timers are enabled.
3772  */
3773 int
3774 bus_delayed_attach_children(device_t dev)
3775 {
3776 	/* Probe and attach the bus children when interrupts are available */
3777 	config_intrhook_oneshot((ich_func_t)bus_generic_attach, dev);
3778 
3779 	return (0);
3780 }
3781 
3782 /**
3783  * @brief Helper function for implementing DEVICE_DETACH()
3784  *
3785  * This function can be used to help implement the DEVICE_DETACH() for
3786  * a bus. It calls device_detach() for each of the device's
3787  * children.
3788  */
3789 int
3790 bus_generic_detach(device_t dev)
3791 {
3792 	device_t child;
3793 	int error;
3794 
3795 	if (dev->state != DS_ATTACHED)
3796 		return (EBUSY);
3797 
3798 	/*
3799 	 * Detach children in the reverse order.
3800 	 * See bus_generic_suspend for details.
3801 	 */
3802 	TAILQ_FOREACH_REVERSE(child, &dev->children, device_list, link) {
3803 		if ((error = device_detach(child)) != 0)
3804 			return (error);
3805 	}
3806 
3807 	return (0);
3808 }
3809 
3810 /**
3811  * @brief Helper function for implementing DEVICE_SHUTDOWN()
3812  *
3813  * This function can be used to help implement the DEVICE_SHUTDOWN()
3814  * for a bus. It calls device_shutdown() for each of the device's
3815  * children.
3816  */
3817 int
3818 bus_generic_shutdown(device_t dev)
3819 {
3820 	device_t child;
3821 
3822 	/*
3823 	 * Shut down children in the reverse order.
3824 	 * See bus_generic_suspend for details.
3825 	 */
3826 	TAILQ_FOREACH_REVERSE(child, &dev->children, device_list, link) {
3827 		device_shutdown(child);
3828 	}
3829 
3830 	return (0);
3831 }
3832 
3833 /**
3834  * @brief Default function for suspending a child device.
3835  *
3836  * This function is to be used by a bus's DEVICE_SUSPEND_CHILD().
3837  */
3838 int
3839 bus_generic_suspend_child(device_t dev, device_t child)
3840 {
3841 	int	error;
3842 
3843 	error = DEVICE_SUSPEND(child);
3844 
3845 	if (error == 0)
3846 		child->flags |= DF_SUSPENDED;
3847 
3848 	return (error);
3849 }
3850 
3851 /**
3852  * @brief Default function for resuming a child device.
3853  *
3854  * This function is to be used by a bus's DEVICE_RESUME_CHILD().
3855  */
3856 int
3857 bus_generic_resume_child(device_t dev, device_t child)
3858 {
3859 	DEVICE_RESUME(child);
3860 	child->flags &= ~DF_SUSPENDED;
3861 
3862 	return (0);
3863 }
3864 
3865 /**
3866  * @brief Helper function for implementing DEVICE_SUSPEND()
3867  *
3868  * This function can be used to help implement the DEVICE_SUSPEND()
3869  * for a bus. It calls DEVICE_SUSPEND() for each of the device's
3870  * children. If any call to DEVICE_SUSPEND() fails, the suspend
3871  * operation is aborted and any devices which were suspended are
3872  * resumed immediately by calling their DEVICE_RESUME() methods.
3873  */
3874 int
3875 bus_generic_suspend(device_t dev)
3876 {
3877 	int		error;
3878 	device_t	child;
3879 
3880 	/*
3881 	 * Suspend children in the reverse order.
3882 	 * For most buses all children are equal, so the order does not matter.
3883 	 * Other buses, such as acpi, carefully order their child devices to
3884 	 * express implicit dependencies between them.  For such buses it is
3885 	 * safer to bring down devices in the reverse order.
3886 	 */
3887 	TAILQ_FOREACH_REVERSE(child, &dev->children, device_list, link) {
3888 		error = BUS_SUSPEND_CHILD(dev, child);
3889 		if (error != 0) {
3890 			child = TAILQ_NEXT(child, link);
3891 			if (child != NULL) {
3892 				TAILQ_FOREACH_FROM(child, &dev->children, link)
3893 					BUS_RESUME_CHILD(dev, child);
3894 			}
3895 			return (error);
3896 		}
3897 	}
3898 	return (0);
3899 }
3900 
3901 /**
3902  * @brief Helper function for implementing DEVICE_RESUME()
3903  *
3904  * This function can be used to help implement the DEVICE_RESUME() for
3905  * a bus. It calls DEVICE_RESUME() on each of the device's children.
3906  */
3907 int
3908 bus_generic_resume(device_t dev)
3909 {
3910 	device_t	child;
3911 
3912 	TAILQ_FOREACH(child, &dev->children, link) {
3913 		BUS_RESUME_CHILD(dev, child);
3914 		/* if resume fails, there's nothing we can usefully do... */
3915 	}
3916 	return (0);
3917 }
3918 
3919 /**
3920  * @brief Helper function for implementing BUS_RESET_POST
3921  *
3922  * Bus can use this function to implement common operations of
3923  * re-attaching or resuming the children after the bus itself was
3924  * reset, and after restoring bus-unique state of children.
3925  *
3926  * @param dev	The bus
3927  * #param flags	DEVF_RESET_*
3928  */
3929 int
3930 bus_helper_reset_post(device_t dev, int flags)
3931 {
3932 	device_t child;
3933 	int error, error1;
3934 
3935 	error = 0;
3936 	TAILQ_FOREACH(child, &dev->children,link) {
3937 		BUS_RESET_POST(dev, child);
3938 		error1 = (flags & DEVF_RESET_DETACH) != 0 ?
3939 		    device_probe_and_attach(child) :
3940 		    BUS_RESUME_CHILD(dev, child);
3941 		if (error == 0 && error1 != 0)
3942 			error = error1;
3943 	}
3944 	return (error);
3945 }
3946 
3947 static void
3948 bus_helper_reset_prepare_rollback(device_t dev, device_t child, int flags)
3949 {
3950 	child = TAILQ_NEXT(child, link);
3951 	if (child == NULL)
3952 		return;
3953 	TAILQ_FOREACH_FROM(child, &dev->children,link) {
3954 		BUS_RESET_POST(dev, child);
3955 		if ((flags & DEVF_RESET_DETACH) != 0)
3956 			device_probe_and_attach(child);
3957 		else
3958 			BUS_RESUME_CHILD(dev, child);
3959 	}
3960 }
3961 
3962 /**
3963  * @brief Helper function for implementing BUS_RESET_PREPARE
3964  *
3965  * Bus can use this function to implement common operations of
3966  * detaching or suspending the children before the bus itself is
3967  * reset, and then save bus-unique state of children that must
3968  * persists around reset.
3969  *
3970  * @param dev	The bus
3971  * #param flags	DEVF_RESET_*
3972  */
3973 int
3974 bus_helper_reset_prepare(device_t dev, int flags)
3975 {
3976 	device_t child;
3977 	int error;
3978 
3979 	if (dev->state != DS_ATTACHED)
3980 		return (EBUSY);
3981 
3982 	TAILQ_FOREACH_REVERSE(child, &dev->children, device_list, link) {
3983 		if ((flags & DEVF_RESET_DETACH) != 0) {
3984 			error = device_get_state(child) == DS_ATTACHED ?
3985 			    device_detach(child) : 0;
3986 		} else {
3987 			error = BUS_SUSPEND_CHILD(dev, child);
3988 		}
3989 		if (error == 0) {
3990 			error = BUS_RESET_PREPARE(dev, child);
3991 			if (error != 0) {
3992 				if ((flags & DEVF_RESET_DETACH) != 0)
3993 					device_probe_and_attach(child);
3994 				else
3995 					BUS_RESUME_CHILD(dev, child);
3996 			}
3997 		}
3998 		if (error != 0) {
3999 			bus_helper_reset_prepare_rollback(dev, child, flags);
4000 			return (error);
4001 		}
4002 	}
4003 	return (0);
4004 }
4005 
4006 /**
4007  * @brief Helper function for implementing BUS_PRINT_CHILD().
4008  *
4009  * This function prints the first part of the ascii representation of
4010  * @p child, including its name, unit and description (if any - see
4011  * device_set_desc()).
4012  *
4013  * @returns the number of characters printed
4014  */
4015 int
4016 bus_print_child_header(device_t dev, device_t child)
4017 {
4018 	int	retval = 0;
4019 
4020 	if (device_get_desc(child)) {
4021 		retval += device_printf(child, "<%s>", device_get_desc(child));
4022 	} else {
4023 		retval += printf("%s", device_get_nameunit(child));
4024 	}
4025 
4026 	return (retval);
4027 }
4028 
4029 /**
4030  * @brief Helper function for implementing BUS_PRINT_CHILD().
4031  *
4032  * This function prints the last part of the ascii representation of
4033  * @p child, which consists of the string @c " on " followed by the
4034  * name and unit of the @p dev.
4035  *
4036  * @returns the number of characters printed
4037  */
4038 int
4039 bus_print_child_footer(device_t dev, device_t child)
4040 {
4041 	return (printf(" on %s\n", device_get_nameunit(dev)));
4042 }
4043 
4044 /**
4045  * @brief Helper function for implementing BUS_PRINT_CHILD().
4046  *
4047  * This function prints out the VM domain for the given device.
4048  *
4049  * @returns the number of characters printed
4050  */
4051 int
4052 bus_print_child_domain(device_t dev, device_t child)
4053 {
4054 	int domain;
4055 
4056 	/* No domain? Don't print anything */
4057 	if (BUS_GET_DOMAIN(dev, child, &domain) != 0)
4058 		return (0);
4059 
4060 	return (printf(" numa-domain %d", domain));
4061 }
4062 
4063 /**
4064  * @brief Helper function for implementing BUS_PRINT_CHILD().
4065  *
4066  * This function simply calls bus_print_child_header() followed by
4067  * bus_print_child_footer().
4068  *
4069  * @returns the number of characters printed
4070  */
4071 int
4072 bus_generic_print_child(device_t dev, device_t child)
4073 {
4074 	int	retval = 0;
4075 
4076 	retval += bus_print_child_header(dev, child);
4077 	retval += bus_print_child_domain(dev, child);
4078 	retval += bus_print_child_footer(dev, child);
4079 
4080 	return (retval);
4081 }
4082 
4083 /**
4084  * @brief Stub function for implementing BUS_READ_IVAR().
4085  *
4086  * @returns ENOENT
4087  */
4088 int
4089 bus_generic_read_ivar(device_t dev, device_t child, int index,
4090     uintptr_t * result)
4091 {
4092 	return (ENOENT);
4093 }
4094 
4095 /**
4096  * @brief Stub function for implementing BUS_WRITE_IVAR().
4097  *
4098  * @returns ENOENT
4099  */
4100 int
4101 bus_generic_write_ivar(device_t dev, device_t child, int index,
4102     uintptr_t value)
4103 {
4104 	return (ENOENT);
4105 }
4106 
4107 /**
4108  * @brief Stub function for implementing BUS_GET_RESOURCE_LIST().
4109  *
4110  * @returns NULL
4111  */
4112 struct resource_list *
4113 bus_generic_get_resource_list(device_t dev, device_t child)
4114 {
4115 	return (NULL);
4116 }
4117 
4118 /**
4119  * @brief Helper function for implementing BUS_DRIVER_ADDED().
4120  *
4121  * This implementation of BUS_DRIVER_ADDED() simply calls the driver's
4122  * DEVICE_IDENTIFY() method to allow it to add new children to the bus
4123  * and then calls device_probe_and_attach() for each unattached child.
4124  */
4125 void
4126 bus_generic_driver_added(device_t dev, driver_t *driver)
4127 {
4128 	device_t child;
4129 
4130 	DEVICE_IDENTIFY(driver, dev);
4131 	TAILQ_FOREACH(child, &dev->children, link) {
4132 		if (child->state == DS_NOTPRESENT ||
4133 		    (child->flags & DF_REBID))
4134 			device_probe_and_attach(child);
4135 	}
4136 }
4137 
4138 /**
4139  * @brief Helper function for implementing BUS_NEW_PASS().
4140  *
4141  * This implementing of BUS_NEW_PASS() first calls the identify
4142  * routines for any drivers that probe at the current pass.  Then it
4143  * walks the list of devices for this bus.  If a device is already
4144  * attached, then it calls BUS_NEW_PASS() on that device.  If the
4145  * device is not already attached, it attempts to attach a driver to
4146  * it.
4147  */
4148 void
4149 bus_generic_new_pass(device_t dev)
4150 {
4151 	driverlink_t dl;
4152 	devclass_t dc;
4153 	device_t child;
4154 
4155 	dc = dev->devclass;
4156 	TAILQ_FOREACH(dl, &dc->drivers, link) {
4157 		if (dl->pass == bus_current_pass)
4158 			DEVICE_IDENTIFY(dl->driver, dev);
4159 	}
4160 	TAILQ_FOREACH(child, &dev->children, link) {
4161 		if (child->state >= DS_ATTACHED)
4162 			BUS_NEW_PASS(child);
4163 		else if (child->state == DS_NOTPRESENT)
4164 			device_probe_and_attach(child);
4165 	}
4166 }
4167 
4168 /**
4169  * @brief Helper function for implementing BUS_SETUP_INTR().
4170  *
4171  * This simple implementation of BUS_SETUP_INTR() simply calls the
4172  * BUS_SETUP_INTR() method of the parent of @p dev.
4173  */
4174 int
4175 bus_generic_setup_intr(device_t dev, device_t child, struct resource *irq,
4176     int flags, driver_filter_t *filter, driver_intr_t *intr, void *arg,
4177     void **cookiep)
4178 {
4179 	/* Propagate up the bus hierarchy until someone handles it. */
4180 	if (dev->parent)
4181 		return (BUS_SETUP_INTR(dev->parent, child, irq, flags,
4182 		    filter, intr, arg, cookiep));
4183 	return (EINVAL);
4184 }
4185 
4186 /**
4187  * @brief Helper function for implementing BUS_TEARDOWN_INTR().
4188  *
4189  * This simple implementation of BUS_TEARDOWN_INTR() simply calls the
4190  * BUS_TEARDOWN_INTR() method of the parent of @p dev.
4191  */
4192 int
4193 bus_generic_teardown_intr(device_t dev, device_t child, struct resource *irq,
4194     void *cookie)
4195 {
4196 	/* Propagate up the bus hierarchy until someone handles it. */
4197 	if (dev->parent)
4198 		return (BUS_TEARDOWN_INTR(dev->parent, child, irq, cookie));
4199 	return (EINVAL);
4200 }
4201 
4202 /**
4203  * @brief Helper function for implementing BUS_SUSPEND_INTR().
4204  *
4205  * This simple implementation of BUS_SUSPEND_INTR() simply calls the
4206  * BUS_SUSPEND_INTR() method of the parent of @p dev.
4207  */
4208 int
4209 bus_generic_suspend_intr(device_t dev, device_t child, struct resource *irq)
4210 {
4211 	/* Propagate up the bus hierarchy until someone handles it. */
4212 	if (dev->parent)
4213 		return (BUS_SUSPEND_INTR(dev->parent, child, irq));
4214 	return (EINVAL);
4215 }
4216 
4217 /**
4218  * @brief Helper function for implementing BUS_RESUME_INTR().
4219  *
4220  * This simple implementation of BUS_RESUME_INTR() simply calls the
4221  * BUS_RESUME_INTR() method of the parent of @p dev.
4222  */
4223 int
4224 bus_generic_resume_intr(device_t dev, device_t child, struct resource *irq)
4225 {
4226 	/* Propagate up the bus hierarchy until someone handles it. */
4227 	if (dev->parent)
4228 		return (BUS_RESUME_INTR(dev->parent, child, irq));
4229 	return (EINVAL);
4230 }
4231 
4232 /**
4233  * @brief Helper function for implementing BUS_ADJUST_RESOURCE().
4234  *
4235  * This simple implementation of BUS_ADJUST_RESOURCE() simply calls the
4236  * BUS_ADJUST_RESOURCE() method of the parent of @p dev.
4237  */
4238 int
4239 bus_generic_adjust_resource(device_t dev, device_t child, int type,
4240     struct resource *r, rman_res_t start, rman_res_t end)
4241 {
4242 	/* Propagate up the bus hierarchy until someone handles it. */
4243 	if (dev->parent)
4244 		return (BUS_ADJUST_RESOURCE(dev->parent, child, type, r, start,
4245 		    end));
4246 	return (EINVAL);
4247 }
4248 
4249 /**
4250  * @brief Helper function for implementing BUS_ALLOC_RESOURCE().
4251  *
4252  * This simple implementation of BUS_ALLOC_RESOURCE() simply calls the
4253  * BUS_ALLOC_RESOURCE() method of the parent of @p dev.
4254  */
4255 struct resource *
4256 bus_generic_alloc_resource(device_t dev, device_t child, int type, int *rid,
4257     rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
4258 {
4259 	/* Propagate up the bus hierarchy until someone handles it. */
4260 	if (dev->parent)
4261 		return (BUS_ALLOC_RESOURCE(dev->parent, child, type, rid,
4262 		    start, end, count, flags));
4263 	return (NULL);
4264 }
4265 
4266 /**
4267  * @brief Helper function for implementing BUS_RELEASE_RESOURCE().
4268  *
4269  * This simple implementation of BUS_RELEASE_RESOURCE() simply calls the
4270  * BUS_RELEASE_RESOURCE() method of the parent of @p dev.
4271  */
4272 int
4273 bus_generic_release_resource(device_t dev, device_t child, int type, int rid,
4274     struct resource *r)
4275 {
4276 	/* Propagate up the bus hierarchy until someone handles it. */
4277 	if (dev->parent)
4278 		return (BUS_RELEASE_RESOURCE(dev->parent, child, type, rid,
4279 		    r));
4280 	return (EINVAL);
4281 }
4282 
4283 /**
4284  * @brief Helper function for implementing BUS_ACTIVATE_RESOURCE().
4285  *
4286  * This simple implementation of BUS_ACTIVATE_RESOURCE() simply calls the
4287  * BUS_ACTIVATE_RESOURCE() method of the parent of @p dev.
4288  */
4289 int
4290 bus_generic_activate_resource(device_t dev, device_t child, int type, int rid,
4291     struct resource *r)
4292 {
4293 	/* Propagate up the bus hierarchy until someone handles it. */
4294 	if (dev->parent)
4295 		return (BUS_ACTIVATE_RESOURCE(dev->parent, child, type, rid,
4296 		    r));
4297 	return (EINVAL);
4298 }
4299 
4300 /**
4301  * @brief Helper function for implementing BUS_DEACTIVATE_RESOURCE().
4302  *
4303  * This simple implementation of BUS_DEACTIVATE_RESOURCE() simply calls the
4304  * BUS_DEACTIVATE_RESOURCE() method of the parent of @p dev.
4305  */
4306 int
4307 bus_generic_deactivate_resource(device_t dev, device_t child, int type,
4308     int rid, struct resource *r)
4309 {
4310 	/* Propagate up the bus hierarchy until someone handles it. */
4311 	if (dev->parent)
4312 		return (BUS_DEACTIVATE_RESOURCE(dev->parent, child, type, rid,
4313 		    r));
4314 	return (EINVAL);
4315 }
4316 
4317 /**
4318  * @brief Helper function for implementing BUS_MAP_RESOURCE().
4319  *
4320  * This simple implementation of BUS_MAP_RESOURCE() simply calls the
4321  * BUS_MAP_RESOURCE() method of the parent of @p dev.
4322  */
4323 int
4324 bus_generic_map_resource(device_t dev, device_t child, int type,
4325     struct resource *r, struct resource_map_request *args,
4326     struct resource_map *map)
4327 {
4328 	/* Propagate up the bus hierarchy until someone handles it. */
4329 	if (dev->parent)
4330 		return (BUS_MAP_RESOURCE(dev->parent, child, type, r, args,
4331 		    map));
4332 	return (EINVAL);
4333 }
4334 
4335 /**
4336  * @brief Helper function for implementing BUS_UNMAP_RESOURCE().
4337  *
4338  * This simple implementation of BUS_UNMAP_RESOURCE() simply calls the
4339  * BUS_UNMAP_RESOURCE() method of the parent of @p dev.
4340  */
4341 int
4342 bus_generic_unmap_resource(device_t dev, device_t child, int type,
4343     struct resource *r, struct resource_map *map)
4344 {
4345 	/* Propagate up the bus hierarchy until someone handles it. */
4346 	if (dev->parent)
4347 		return (BUS_UNMAP_RESOURCE(dev->parent, child, type, r, map));
4348 	return (EINVAL);
4349 }
4350 
4351 /**
4352  * @brief Helper function for implementing BUS_BIND_INTR().
4353  *
4354  * This simple implementation of BUS_BIND_INTR() simply calls the
4355  * BUS_BIND_INTR() method of the parent of @p dev.
4356  */
4357 int
4358 bus_generic_bind_intr(device_t dev, device_t child, struct resource *irq,
4359     int cpu)
4360 {
4361 	/* Propagate up the bus hierarchy until someone handles it. */
4362 	if (dev->parent)
4363 		return (BUS_BIND_INTR(dev->parent, child, irq, cpu));
4364 	return (EINVAL);
4365 }
4366 
4367 /**
4368  * @brief Helper function for implementing BUS_CONFIG_INTR().
4369  *
4370  * This simple implementation of BUS_CONFIG_INTR() simply calls the
4371  * BUS_CONFIG_INTR() method of the parent of @p dev.
4372  */
4373 int
4374 bus_generic_config_intr(device_t dev, int irq, enum intr_trigger trig,
4375     enum intr_polarity pol)
4376 {
4377 	/* Propagate up the bus hierarchy until someone handles it. */
4378 	if (dev->parent)
4379 		return (BUS_CONFIG_INTR(dev->parent, irq, trig, pol));
4380 	return (EINVAL);
4381 }
4382 
4383 /**
4384  * @brief Helper function for implementing BUS_DESCRIBE_INTR().
4385  *
4386  * This simple implementation of BUS_DESCRIBE_INTR() simply calls the
4387  * BUS_DESCRIBE_INTR() method of the parent of @p dev.
4388  */
4389 int
4390 bus_generic_describe_intr(device_t dev, device_t child, struct resource *irq,
4391     void *cookie, const char *descr)
4392 {
4393 	/* Propagate up the bus hierarchy until someone handles it. */
4394 	if (dev->parent)
4395 		return (BUS_DESCRIBE_INTR(dev->parent, child, irq, cookie,
4396 		    descr));
4397 	return (EINVAL);
4398 }
4399 
4400 /**
4401  * @brief Helper function for implementing BUS_GET_CPUS().
4402  *
4403  * This simple implementation of BUS_GET_CPUS() simply calls the
4404  * BUS_GET_CPUS() method of the parent of @p dev.
4405  */
4406 int
4407 bus_generic_get_cpus(device_t dev, device_t child, enum cpu_sets op,
4408     size_t setsize, cpuset_t *cpuset)
4409 {
4410 	/* Propagate up the bus hierarchy until someone handles it. */
4411 	if (dev->parent != NULL)
4412 		return (BUS_GET_CPUS(dev->parent, child, op, setsize, cpuset));
4413 	return (EINVAL);
4414 }
4415 
4416 /**
4417  * @brief Helper function for implementing BUS_GET_DMA_TAG().
4418  *
4419  * This simple implementation of BUS_GET_DMA_TAG() simply calls the
4420  * BUS_GET_DMA_TAG() method of the parent of @p dev.
4421  */
4422 bus_dma_tag_t
4423 bus_generic_get_dma_tag(device_t dev, device_t child)
4424 {
4425 	/* Propagate up the bus hierarchy until someone handles it. */
4426 	if (dev->parent != NULL)
4427 		return (BUS_GET_DMA_TAG(dev->parent, child));
4428 	return (NULL);
4429 }
4430 
4431 /**
4432  * @brief Helper function for implementing BUS_GET_BUS_TAG().
4433  *
4434  * This simple implementation of BUS_GET_BUS_TAG() simply calls the
4435  * BUS_GET_BUS_TAG() method of the parent of @p dev.
4436  */
4437 bus_space_tag_t
4438 bus_generic_get_bus_tag(device_t dev, device_t child)
4439 {
4440 	/* Propagate up the bus hierarchy until someone handles it. */
4441 	if (dev->parent != NULL)
4442 		return (BUS_GET_BUS_TAG(dev->parent, child));
4443 	return ((bus_space_tag_t)0);
4444 }
4445 
4446 /**
4447  * @brief Helper function for implementing BUS_GET_RESOURCE().
4448  *
4449  * This implementation of BUS_GET_RESOURCE() uses the
4450  * resource_list_find() function to do most of the work. It calls
4451  * BUS_GET_RESOURCE_LIST() to find a suitable resource list to
4452  * search.
4453  */
4454 int
4455 bus_generic_rl_get_resource(device_t dev, device_t child, int type, int rid,
4456     rman_res_t *startp, rman_res_t *countp)
4457 {
4458 	struct resource_list *		rl = NULL;
4459 	struct resource_list_entry *	rle = NULL;
4460 
4461 	rl = BUS_GET_RESOURCE_LIST(dev, child);
4462 	if (!rl)
4463 		return (EINVAL);
4464 
4465 	rle = resource_list_find(rl, type, rid);
4466 	if (!rle)
4467 		return (ENOENT);
4468 
4469 	if (startp)
4470 		*startp = rle->start;
4471 	if (countp)
4472 		*countp = rle->count;
4473 
4474 	return (0);
4475 }
4476 
4477 /**
4478  * @brief Helper function for implementing BUS_SET_RESOURCE().
4479  *
4480  * This implementation of BUS_SET_RESOURCE() uses the
4481  * resource_list_add() function to do most of the work. It calls
4482  * BUS_GET_RESOURCE_LIST() to find a suitable resource list to
4483  * edit.
4484  */
4485 int
4486 bus_generic_rl_set_resource(device_t dev, device_t child, int type, int rid,
4487     rman_res_t start, rman_res_t count)
4488 {
4489 	struct resource_list *		rl = NULL;
4490 
4491 	rl = BUS_GET_RESOURCE_LIST(dev, child);
4492 	if (!rl)
4493 		return (EINVAL);
4494 
4495 	resource_list_add(rl, type, rid, start, (start + count - 1), count);
4496 
4497 	return (0);
4498 }
4499 
4500 /**
4501  * @brief Helper function for implementing BUS_DELETE_RESOURCE().
4502  *
4503  * This implementation of BUS_DELETE_RESOURCE() uses the
4504  * resource_list_delete() function to do most of the work. It calls
4505  * BUS_GET_RESOURCE_LIST() to find a suitable resource list to
4506  * edit.
4507  */
4508 void
4509 bus_generic_rl_delete_resource(device_t dev, device_t child, int type, int rid)
4510 {
4511 	struct resource_list *		rl = NULL;
4512 
4513 	rl = BUS_GET_RESOURCE_LIST(dev, child);
4514 	if (!rl)
4515 		return;
4516 
4517 	resource_list_delete(rl, type, rid);
4518 
4519 	return;
4520 }
4521 
4522 /**
4523  * @brief Helper function for implementing BUS_RELEASE_RESOURCE().
4524  *
4525  * This implementation of BUS_RELEASE_RESOURCE() uses the
4526  * resource_list_release() function to do most of the work. It calls
4527  * BUS_GET_RESOURCE_LIST() to find a suitable resource list.
4528  */
4529 int
4530 bus_generic_rl_release_resource(device_t dev, device_t child, int type,
4531     int rid, struct resource *r)
4532 {
4533 	struct resource_list *		rl = NULL;
4534 
4535 	if (device_get_parent(child) != dev)
4536 		return (BUS_RELEASE_RESOURCE(device_get_parent(dev), child,
4537 		    type, rid, r));
4538 
4539 	rl = BUS_GET_RESOURCE_LIST(dev, child);
4540 	if (!rl)
4541 		return (EINVAL);
4542 
4543 	return (resource_list_release(rl, dev, child, type, rid, r));
4544 }
4545 
4546 /**
4547  * @brief Helper function for implementing BUS_ALLOC_RESOURCE().
4548  *
4549  * This implementation of BUS_ALLOC_RESOURCE() uses the
4550  * resource_list_alloc() function to do most of the work. It calls
4551  * BUS_GET_RESOURCE_LIST() to find a suitable resource list.
4552  */
4553 struct resource *
4554 bus_generic_rl_alloc_resource(device_t dev, device_t child, int type,
4555     int *rid, rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
4556 {
4557 	struct resource_list *		rl = NULL;
4558 
4559 	if (device_get_parent(child) != dev)
4560 		return (BUS_ALLOC_RESOURCE(device_get_parent(dev), child,
4561 		    type, rid, start, end, count, flags));
4562 
4563 	rl = BUS_GET_RESOURCE_LIST(dev, child);
4564 	if (!rl)
4565 		return (NULL);
4566 
4567 	return (resource_list_alloc(rl, dev, child, type, rid,
4568 	    start, end, count, flags));
4569 }
4570 
4571 /**
4572  * @brief Helper function for implementing BUS_CHILD_PRESENT().
4573  *
4574  * This simple implementation of BUS_CHILD_PRESENT() simply calls the
4575  * BUS_CHILD_PRESENT() method of the parent of @p dev.
4576  */
4577 int
4578 bus_generic_child_present(device_t dev, device_t child)
4579 {
4580 	return (BUS_CHILD_PRESENT(device_get_parent(dev), dev));
4581 }
4582 
4583 int
4584 bus_generic_get_domain(device_t dev, device_t child, int *domain)
4585 {
4586 	if (dev->parent)
4587 		return (BUS_GET_DOMAIN(dev->parent, dev, domain));
4588 
4589 	return (ENOENT);
4590 }
4591 
4592 /**
4593  * @brief Helper function for implementing BUS_RESCAN().
4594  *
4595  * This null implementation of BUS_RESCAN() always fails to indicate
4596  * the bus does not support rescanning.
4597  */
4598 int
4599 bus_null_rescan(device_t dev)
4600 {
4601 	return (ENXIO);
4602 }
4603 
4604 /*
4605  * Some convenience functions to make it easier for drivers to use the
4606  * resource-management functions.  All these really do is hide the
4607  * indirection through the parent's method table, making for slightly
4608  * less-wordy code.  In the future, it might make sense for this code
4609  * to maintain some sort of a list of resources allocated by each device.
4610  */
4611 
4612 int
4613 bus_alloc_resources(device_t dev, struct resource_spec *rs,
4614     struct resource **res)
4615 {
4616 	int i;
4617 
4618 	for (i = 0; rs[i].type != -1; i++)
4619 		res[i] = NULL;
4620 	for (i = 0; rs[i].type != -1; i++) {
4621 		res[i] = bus_alloc_resource_any(dev,
4622 		    rs[i].type, &rs[i].rid, rs[i].flags);
4623 		if (res[i] == NULL && !(rs[i].flags & RF_OPTIONAL)) {
4624 			bus_release_resources(dev, rs, res);
4625 			return (ENXIO);
4626 		}
4627 	}
4628 	return (0);
4629 }
4630 
4631 void
4632 bus_release_resources(device_t dev, const struct resource_spec *rs,
4633     struct resource **res)
4634 {
4635 	int i;
4636 
4637 	for (i = 0; rs[i].type != -1; i++)
4638 		if (res[i] != NULL) {
4639 			bus_release_resource(
4640 			    dev, rs[i].type, rs[i].rid, res[i]);
4641 			res[i] = NULL;
4642 		}
4643 }
4644 
4645 /**
4646  * @brief Wrapper function for BUS_ALLOC_RESOURCE().
4647  *
4648  * This function simply calls the BUS_ALLOC_RESOURCE() method of the
4649  * parent of @p dev.
4650  */
4651 struct resource *
4652 bus_alloc_resource(device_t dev, int type, int *rid, rman_res_t start,
4653     rman_res_t end, rman_res_t count, u_int flags)
4654 {
4655 	struct resource *res;
4656 
4657 	if (dev->parent == NULL)
4658 		return (NULL);
4659 	res = BUS_ALLOC_RESOURCE(dev->parent, dev, type, rid, start, end,
4660 	    count, flags);
4661 	return (res);
4662 }
4663 
4664 /**
4665  * @brief Wrapper function for BUS_ADJUST_RESOURCE().
4666  *
4667  * This function simply calls the BUS_ADJUST_RESOURCE() method of the
4668  * parent of @p dev.
4669  */
4670 int
4671 bus_adjust_resource(device_t dev, int type, struct resource *r, rman_res_t start,
4672     rman_res_t end)
4673 {
4674 	if (dev->parent == NULL)
4675 		return (EINVAL);
4676 	return (BUS_ADJUST_RESOURCE(dev->parent, dev, type, r, start, end));
4677 }
4678 
4679 /**
4680  * @brief Wrapper function for BUS_ACTIVATE_RESOURCE().
4681  *
4682  * This function simply calls the BUS_ACTIVATE_RESOURCE() method of the
4683  * parent of @p dev.
4684  */
4685 int
4686 bus_activate_resource(device_t dev, int type, int rid, struct resource *r)
4687 {
4688 	if (dev->parent == NULL)
4689 		return (EINVAL);
4690 	return (BUS_ACTIVATE_RESOURCE(dev->parent, dev, type, rid, r));
4691 }
4692 
4693 /**
4694  * @brief Wrapper function for BUS_DEACTIVATE_RESOURCE().
4695  *
4696  * This function simply calls the BUS_DEACTIVATE_RESOURCE() method of the
4697  * parent of @p dev.
4698  */
4699 int
4700 bus_deactivate_resource(device_t dev, int type, int rid, struct resource *r)
4701 {
4702 	if (dev->parent == NULL)
4703 		return (EINVAL);
4704 	return (BUS_DEACTIVATE_RESOURCE(dev->parent, dev, type, rid, r));
4705 }
4706 
4707 /**
4708  * @brief Wrapper function for BUS_MAP_RESOURCE().
4709  *
4710  * This function simply calls the BUS_MAP_RESOURCE() method of the
4711  * parent of @p dev.
4712  */
4713 int
4714 bus_map_resource(device_t dev, int type, struct resource *r,
4715     struct resource_map_request *args, struct resource_map *map)
4716 {
4717 	if (dev->parent == NULL)
4718 		return (EINVAL);
4719 	return (BUS_MAP_RESOURCE(dev->parent, dev, type, r, args, map));
4720 }
4721 
4722 /**
4723  * @brief Wrapper function for BUS_UNMAP_RESOURCE().
4724  *
4725  * This function simply calls the BUS_UNMAP_RESOURCE() method of the
4726  * parent of @p dev.
4727  */
4728 int
4729 bus_unmap_resource(device_t dev, int type, struct resource *r,
4730     struct resource_map *map)
4731 {
4732 	if (dev->parent == NULL)
4733 		return (EINVAL);
4734 	return (BUS_UNMAP_RESOURCE(dev->parent, dev, type, r, map));
4735 }
4736 
4737 /**
4738  * @brief Wrapper function for BUS_RELEASE_RESOURCE().
4739  *
4740  * This function simply calls the BUS_RELEASE_RESOURCE() method of the
4741  * parent of @p dev.
4742  */
4743 int
4744 bus_release_resource(device_t dev, int type, int rid, struct resource *r)
4745 {
4746 	int rv;
4747 
4748 	if (dev->parent == NULL)
4749 		return (EINVAL);
4750 	rv = BUS_RELEASE_RESOURCE(dev->parent, dev, type, rid, r);
4751 	return (rv);
4752 }
4753 
4754 /**
4755  * @brief Wrapper function for BUS_SETUP_INTR().
4756  *
4757  * This function simply calls the BUS_SETUP_INTR() method of the
4758  * parent of @p dev.
4759  */
4760 int
4761 bus_setup_intr(device_t dev, struct resource *r, int flags,
4762     driver_filter_t filter, driver_intr_t handler, void *arg, void **cookiep)
4763 {
4764 	int error;
4765 
4766 	if (dev->parent == NULL)
4767 		return (EINVAL);
4768 	error = BUS_SETUP_INTR(dev->parent, dev, r, flags, filter, handler,
4769 	    arg, cookiep);
4770 	if (error != 0)
4771 		return (error);
4772 	if (handler != NULL && !(flags & INTR_MPSAFE))
4773 		device_printf(dev, "[GIANT-LOCKED]\n");
4774 	return (0);
4775 }
4776 
4777 /**
4778  * @brief Wrapper function for BUS_TEARDOWN_INTR().
4779  *
4780  * This function simply calls the BUS_TEARDOWN_INTR() method of the
4781  * parent of @p dev.
4782  */
4783 int
4784 bus_teardown_intr(device_t dev, struct resource *r, void *cookie)
4785 {
4786 	if (dev->parent == NULL)
4787 		return (EINVAL);
4788 	return (BUS_TEARDOWN_INTR(dev->parent, dev, r, cookie));
4789 }
4790 
4791 /**
4792  * @brief Wrapper function for BUS_SUSPEND_INTR().
4793  *
4794  * This function simply calls the BUS_SUSPEND_INTR() method of the
4795  * parent of @p dev.
4796  */
4797 int
4798 bus_suspend_intr(device_t dev, struct resource *r)
4799 {
4800 	if (dev->parent == NULL)
4801 		return (EINVAL);
4802 	return (BUS_SUSPEND_INTR(dev->parent, dev, r));
4803 }
4804 
4805 /**
4806  * @brief Wrapper function for BUS_RESUME_INTR().
4807  *
4808  * This function simply calls the BUS_RESUME_INTR() method of the
4809  * parent of @p dev.
4810  */
4811 int
4812 bus_resume_intr(device_t dev, struct resource *r)
4813 {
4814 	if (dev->parent == NULL)
4815 		return (EINVAL);
4816 	return (BUS_RESUME_INTR(dev->parent, dev, r));
4817 }
4818 
4819 /**
4820  * @brief Wrapper function for BUS_BIND_INTR().
4821  *
4822  * This function simply calls the BUS_BIND_INTR() method of the
4823  * parent of @p dev.
4824  */
4825 int
4826 bus_bind_intr(device_t dev, struct resource *r, int cpu)
4827 {
4828 	if (dev->parent == NULL)
4829 		return (EINVAL);
4830 	return (BUS_BIND_INTR(dev->parent, dev, r, cpu));
4831 }
4832 
4833 /**
4834  * @brief Wrapper function for BUS_DESCRIBE_INTR().
4835  *
4836  * This function first formats the requested description into a
4837  * temporary buffer and then calls the BUS_DESCRIBE_INTR() method of
4838  * the parent of @p dev.
4839  */
4840 int
4841 bus_describe_intr(device_t dev, struct resource *irq, void *cookie,
4842     const char *fmt, ...)
4843 {
4844 	va_list ap;
4845 	char descr[MAXCOMLEN + 1];
4846 
4847 	if (dev->parent == NULL)
4848 		return (EINVAL);
4849 	va_start(ap, fmt);
4850 	vsnprintf(descr, sizeof(descr), fmt, ap);
4851 	va_end(ap);
4852 	return (BUS_DESCRIBE_INTR(dev->parent, dev, irq, cookie, descr));
4853 }
4854 
4855 /**
4856  * @brief Wrapper function for BUS_SET_RESOURCE().
4857  *
4858  * This function simply calls the BUS_SET_RESOURCE() method of the
4859  * parent of @p dev.
4860  */
4861 int
4862 bus_set_resource(device_t dev, int type, int rid,
4863     rman_res_t start, rman_res_t count)
4864 {
4865 	return (BUS_SET_RESOURCE(device_get_parent(dev), dev, type, rid,
4866 	    start, count));
4867 }
4868 
4869 /**
4870  * @brief Wrapper function for BUS_GET_RESOURCE().
4871  *
4872  * This function simply calls the BUS_GET_RESOURCE() method of the
4873  * parent of @p dev.
4874  */
4875 int
4876 bus_get_resource(device_t dev, int type, int rid,
4877     rman_res_t *startp, rman_res_t *countp)
4878 {
4879 	return (BUS_GET_RESOURCE(device_get_parent(dev), dev, type, rid,
4880 	    startp, countp));
4881 }
4882 
4883 /**
4884  * @brief Wrapper function for BUS_GET_RESOURCE().
4885  *
4886  * This function simply calls the BUS_GET_RESOURCE() method of the
4887  * parent of @p dev and returns the start value.
4888  */
4889 rman_res_t
4890 bus_get_resource_start(device_t dev, int type, int rid)
4891 {
4892 	rman_res_t start;
4893 	rman_res_t count;
4894 	int error;
4895 
4896 	error = BUS_GET_RESOURCE(device_get_parent(dev), dev, type, rid,
4897 	    &start, &count);
4898 	if (error)
4899 		return (0);
4900 	return (start);
4901 }
4902 
4903 /**
4904  * @brief Wrapper function for BUS_GET_RESOURCE().
4905  *
4906  * This function simply calls the BUS_GET_RESOURCE() method of the
4907  * parent of @p dev and returns the count value.
4908  */
4909 rman_res_t
4910 bus_get_resource_count(device_t dev, int type, int rid)
4911 {
4912 	rman_res_t start;
4913 	rman_res_t count;
4914 	int error;
4915 
4916 	error = BUS_GET_RESOURCE(device_get_parent(dev), dev, type, rid,
4917 	    &start, &count);
4918 	if (error)
4919 		return (0);
4920 	return (count);
4921 }
4922 
4923 /**
4924  * @brief Wrapper function for BUS_DELETE_RESOURCE().
4925  *
4926  * This function simply calls the BUS_DELETE_RESOURCE() method of the
4927  * parent of @p dev.
4928  */
4929 void
4930 bus_delete_resource(device_t dev, int type, int rid)
4931 {
4932 	BUS_DELETE_RESOURCE(device_get_parent(dev), dev, type, rid);
4933 }
4934 
4935 /**
4936  * @brief Wrapper function for BUS_CHILD_PRESENT().
4937  *
4938  * This function simply calls the BUS_CHILD_PRESENT() method of the
4939  * parent of @p dev.
4940  */
4941 int
4942 bus_child_present(device_t child)
4943 {
4944 	return (BUS_CHILD_PRESENT(device_get_parent(child), child));
4945 }
4946 
4947 /**
4948  * @brief Wrapper function for BUS_CHILD_PNPINFO().
4949  *
4950  * This function simply calls the BUS_CHILD_PNPINFO() method of the parent of @p
4951  * dev.
4952  */
4953 int
4954 bus_child_pnpinfo(device_t child, struct sbuf *sb)
4955 {
4956 	device_t parent;
4957 
4958 	parent = device_get_parent(child);
4959 	if (parent == NULL)
4960 		return (0);
4961 	return (BUS_CHILD_PNPINFO(parent, child, sb));
4962 }
4963 
4964 /**
4965  * @brief Generic implementation that does nothing for bus_child_pnpinfo
4966  *
4967  * This function has the right signature and returns 0 since the sbuf is passed
4968  * to us to append to.
4969  */
4970 int
4971 bus_generic_child_pnpinfo(device_t dev, device_t child, struct sbuf *sb)
4972 {
4973 	return (0);
4974 }
4975 
4976 /**
4977  * @brief Wrapper function for BUS_CHILD_LOCATION().
4978  *
4979  * This function simply calls the BUS_CHILD_LOCATION() method of the parent of
4980  * @p dev.
4981  */
4982 int
4983 bus_child_location(device_t child, struct sbuf *sb)
4984 {
4985 	device_t parent;
4986 
4987 	parent = device_get_parent(child);
4988 	if (parent == NULL)
4989 		return (0);
4990 	return (BUS_CHILD_LOCATION(parent, child, sb));
4991 }
4992 
4993 /**
4994  * @brief Generic implementation that does nothing for bus_child_location
4995  *
4996  * This function has the right signature and returns 0 since the sbuf is passed
4997  * to us to append to.
4998  */
4999 int
5000 bus_generic_child_location(device_t dev, device_t child, struct sbuf *sb)
5001 {
5002 	return (0);
5003 }
5004 
5005 /**
5006  * @brief Wrapper function for BUS_GET_CPUS().
5007  *
5008  * This function simply calls the BUS_GET_CPUS() method of the
5009  * parent of @p dev.
5010  */
5011 int
5012 bus_get_cpus(device_t dev, enum cpu_sets op, size_t setsize, cpuset_t *cpuset)
5013 {
5014 	device_t parent;
5015 
5016 	parent = device_get_parent(dev);
5017 	if (parent == NULL)
5018 		return (EINVAL);
5019 	return (BUS_GET_CPUS(parent, dev, op, setsize, cpuset));
5020 }
5021 
5022 /**
5023  * @brief Wrapper function for BUS_GET_DMA_TAG().
5024  *
5025  * This function simply calls the BUS_GET_DMA_TAG() method of the
5026  * parent of @p dev.
5027  */
5028 bus_dma_tag_t
5029 bus_get_dma_tag(device_t dev)
5030 {
5031 	device_t parent;
5032 
5033 	parent = device_get_parent(dev);
5034 	if (parent == NULL)
5035 		return (NULL);
5036 	return (BUS_GET_DMA_TAG(parent, dev));
5037 }
5038 
5039 /**
5040  * @brief Wrapper function for BUS_GET_BUS_TAG().
5041  *
5042  * This function simply calls the BUS_GET_BUS_TAG() method of the
5043  * parent of @p dev.
5044  */
5045 bus_space_tag_t
5046 bus_get_bus_tag(device_t dev)
5047 {
5048 	device_t parent;
5049 
5050 	parent = device_get_parent(dev);
5051 	if (parent == NULL)
5052 		return ((bus_space_tag_t)0);
5053 	return (BUS_GET_BUS_TAG(parent, dev));
5054 }
5055 
5056 /**
5057  * @brief Wrapper function for BUS_GET_DOMAIN().
5058  *
5059  * This function simply calls the BUS_GET_DOMAIN() method of the
5060  * parent of @p dev.
5061  */
5062 int
5063 bus_get_domain(device_t dev, int *domain)
5064 {
5065 	return (BUS_GET_DOMAIN(device_get_parent(dev), dev, domain));
5066 }
5067 
5068 /* Resume all devices and then notify userland that we're up again. */
5069 static int
5070 root_resume(device_t dev)
5071 {
5072 	int error;
5073 
5074 	error = bus_generic_resume(dev);
5075 	if (error == 0) {
5076 		devctl_notify("kern", "power", "resume", NULL); /* Deprecated gone in 14 */
5077 		devctl_notify("kernel", "power", "resume", NULL);
5078 	}
5079 	return (error);
5080 }
5081 
5082 static int
5083 root_print_child(device_t dev, device_t child)
5084 {
5085 	int	retval = 0;
5086 
5087 	retval += bus_print_child_header(dev, child);
5088 	retval += printf("\n");
5089 
5090 	return (retval);
5091 }
5092 
5093 static int
5094 root_setup_intr(device_t dev, device_t child, struct resource *irq, int flags,
5095     driver_filter_t *filter, driver_intr_t *intr, void *arg, void **cookiep)
5096 {
5097 	/*
5098 	 * If an interrupt mapping gets to here something bad has happened.
5099 	 */
5100 	panic("root_setup_intr");
5101 }
5102 
5103 /*
5104  * If we get here, assume that the device is permanent and really is
5105  * present in the system.  Removable bus drivers are expected to intercept
5106  * this call long before it gets here.  We return -1 so that drivers that
5107  * really care can check vs -1 or some ERRNO returned higher in the food
5108  * chain.
5109  */
5110 static int
5111 root_child_present(device_t dev, device_t child)
5112 {
5113 	return (-1);
5114 }
5115 
5116 static int
5117 root_get_cpus(device_t dev, device_t child, enum cpu_sets op, size_t setsize,
5118     cpuset_t *cpuset)
5119 {
5120 	switch (op) {
5121 	case INTR_CPUS:
5122 		/* Default to returning the set of all CPUs. */
5123 		if (setsize != sizeof(cpuset_t))
5124 			return (EINVAL);
5125 		*cpuset = all_cpus;
5126 		return (0);
5127 	default:
5128 		return (EINVAL);
5129 	}
5130 }
5131 
5132 static kobj_method_t root_methods[] = {
5133 	/* Device interface */
5134 	KOBJMETHOD(device_shutdown,	bus_generic_shutdown),
5135 	KOBJMETHOD(device_suspend,	bus_generic_suspend),
5136 	KOBJMETHOD(device_resume,	root_resume),
5137 
5138 	/* Bus interface */
5139 	KOBJMETHOD(bus_print_child,	root_print_child),
5140 	KOBJMETHOD(bus_read_ivar,	bus_generic_read_ivar),
5141 	KOBJMETHOD(bus_write_ivar,	bus_generic_write_ivar),
5142 	KOBJMETHOD(bus_setup_intr,	root_setup_intr),
5143 	KOBJMETHOD(bus_child_present,	root_child_present),
5144 	KOBJMETHOD(bus_get_cpus,	root_get_cpus),
5145 
5146 	KOBJMETHOD_END
5147 };
5148 
5149 static driver_t root_driver = {
5150 	"root",
5151 	root_methods,
5152 	1,			/* no softc */
5153 };
5154 
5155 device_t	root_bus;
5156 devclass_t	root_devclass;
5157 
5158 static int
5159 root_bus_module_handler(module_t mod, int what, void* arg)
5160 {
5161 	switch (what) {
5162 	case MOD_LOAD:
5163 		TAILQ_INIT(&bus_data_devices);
5164 		kobj_class_compile((kobj_class_t) &root_driver);
5165 		root_bus = make_device(NULL, "root", 0);
5166 		root_bus->desc = "System root bus";
5167 		kobj_init((kobj_t) root_bus, (kobj_class_t) &root_driver);
5168 		root_bus->driver = &root_driver;
5169 		root_bus->state = DS_ATTACHED;
5170 		root_devclass = devclass_find_internal("root", NULL, FALSE);
5171 		devinit();
5172 		return (0);
5173 
5174 	case MOD_SHUTDOWN:
5175 		device_shutdown(root_bus);
5176 		return (0);
5177 	default:
5178 		return (EOPNOTSUPP);
5179 	}
5180 
5181 	return (0);
5182 }
5183 
5184 static moduledata_t root_bus_mod = {
5185 	"rootbus",
5186 	root_bus_module_handler,
5187 	NULL
5188 };
5189 DECLARE_MODULE(rootbus, root_bus_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
5190 
5191 /**
5192  * @brief Automatically configure devices
5193  *
5194  * This function begins the autoconfiguration process by calling
5195  * device_probe_and_attach() for each child of the @c root0 device.
5196  */
5197 void
5198 root_bus_configure(void)
5199 {
5200 	PDEBUG(("."));
5201 
5202 	/* Eventually this will be split up, but this is sufficient for now. */
5203 	bus_set_pass(BUS_PASS_DEFAULT);
5204 }
5205 
5206 /**
5207  * @brief Module handler for registering device drivers
5208  *
5209  * This module handler is used to automatically register device
5210  * drivers when modules are loaded. If @p what is MOD_LOAD, it calls
5211  * devclass_add_driver() for the driver described by the
5212  * driver_module_data structure pointed to by @p arg
5213  */
5214 int
5215 driver_module_handler(module_t mod, int what, void *arg)
5216 {
5217 	struct driver_module_data *dmd;
5218 	devclass_t bus_devclass;
5219 	kobj_class_t driver;
5220 	int error, pass;
5221 
5222 	dmd = (struct driver_module_data *)arg;
5223 	bus_devclass = devclass_find_internal(dmd->dmd_busname, NULL, TRUE);
5224 	error = 0;
5225 
5226 	switch (what) {
5227 	case MOD_LOAD:
5228 		if (dmd->dmd_chainevh)
5229 			error = dmd->dmd_chainevh(mod,what,dmd->dmd_chainarg);
5230 
5231 		pass = dmd->dmd_pass;
5232 		driver = dmd->dmd_driver;
5233 		PDEBUG(("Loading module: driver %s on bus %s (pass %d)",
5234 		    DRIVERNAME(driver), dmd->dmd_busname, pass));
5235 		error = devclass_add_driver(bus_devclass, driver, pass,
5236 		    dmd->dmd_devclass);
5237 		break;
5238 
5239 	case MOD_UNLOAD:
5240 		PDEBUG(("Unloading module: driver %s from bus %s",
5241 		    DRIVERNAME(dmd->dmd_driver),
5242 		    dmd->dmd_busname));
5243 		error = devclass_delete_driver(bus_devclass,
5244 		    dmd->dmd_driver);
5245 
5246 		if (!error && dmd->dmd_chainevh)
5247 			error = dmd->dmd_chainevh(mod,what,dmd->dmd_chainarg);
5248 		break;
5249 	case MOD_QUIESCE:
5250 		PDEBUG(("Quiesce module: driver %s from bus %s",
5251 		    DRIVERNAME(dmd->dmd_driver),
5252 		    dmd->dmd_busname));
5253 		error = devclass_quiesce_driver(bus_devclass,
5254 		    dmd->dmd_driver);
5255 
5256 		if (!error && dmd->dmd_chainevh)
5257 			error = dmd->dmd_chainevh(mod,what,dmd->dmd_chainarg);
5258 		break;
5259 	default:
5260 		error = EOPNOTSUPP;
5261 		break;
5262 	}
5263 
5264 	return (error);
5265 }
5266 
5267 /**
5268  * @brief Enumerate all hinted devices for this bus.
5269  *
5270  * Walks through the hints for this bus and calls the bus_hinted_child
5271  * routine for each one it fines.  It searches first for the specific
5272  * bus that's being probed for hinted children (eg isa0), and then for
5273  * generic children (eg isa).
5274  *
5275  * @param	dev	bus device to enumerate
5276  */
5277 void
5278 bus_enumerate_hinted_children(device_t bus)
5279 {
5280 	int i;
5281 	const char *dname, *busname;
5282 	int dunit;
5283 
5284 	/*
5285 	 * enumerate all devices on the specific bus
5286 	 */
5287 	busname = device_get_nameunit(bus);
5288 	i = 0;
5289 	while (resource_find_match(&i, &dname, &dunit, "at", busname) == 0)
5290 		BUS_HINTED_CHILD(bus, dname, dunit);
5291 
5292 	/*
5293 	 * and all the generic ones.
5294 	 */
5295 	busname = device_get_name(bus);
5296 	i = 0;
5297 	while (resource_find_match(&i, &dname, &dunit, "at", busname) == 0)
5298 		BUS_HINTED_CHILD(bus, dname, dunit);
5299 }
5300 
5301 #ifdef BUS_DEBUG
5302 
5303 /* the _short versions avoid iteration by not calling anything that prints
5304  * more than oneliners. I love oneliners.
5305  */
5306 
5307 static void
5308 print_device_short(device_t dev, int indent)
5309 {
5310 	if (!dev)
5311 		return;
5312 
5313 	indentprintf(("device %d: <%s> %sparent,%schildren,%s%s%s%s%s%s,%sivars,%ssoftc,busy=%d\n",
5314 	    dev->unit, dev->desc,
5315 	    (dev->parent? "":"no "),
5316 	    (TAILQ_EMPTY(&dev->children)? "no ":""),
5317 	    (dev->flags&DF_ENABLED? "enabled,":"disabled,"),
5318 	    (dev->flags&DF_FIXEDCLASS? "fixed,":""),
5319 	    (dev->flags&DF_WILDCARD? "wildcard,":""),
5320 	    (dev->flags&DF_DESCMALLOCED? "descmalloced,":""),
5321 	    (dev->flags&DF_REBID? "rebiddable,":""),
5322 	    (dev->flags&DF_SUSPENDED? "suspended,":""),
5323 	    (dev->ivars? "":"no "),
5324 	    (dev->softc? "":"no "),
5325 	    dev->busy));
5326 }
5327 
5328 static void
5329 print_device(device_t dev, int indent)
5330 {
5331 	if (!dev)
5332 		return;
5333 
5334 	print_device_short(dev, indent);
5335 
5336 	indentprintf(("Parent:\n"));
5337 	print_device_short(dev->parent, indent+1);
5338 	indentprintf(("Driver:\n"));
5339 	print_driver_short(dev->driver, indent+1);
5340 	indentprintf(("Devclass:\n"));
5341 	print_devclass_short(dev->devclass, indent+1);
5342 }
5343 
5344 void
5345 print_device_tree_short(device_t dev, int indent)
5346 /* print the device and all its children (indented) */
5347 {
5348 	device_t child;
5349 
5350 	if (!dev)
5351 		return;
5352 
5353 	print_device_short(dev, indent);
5354 
5355 	TAILQ_FOREACH(child, &dev->children, link) {
5356 		print_device_tree_short(child, indent+1);
5357 	}
5358 }
5359 
5360 void
5361 print_device_tree(device_t dev, int indent)
5362 /* print the device and all its children (indented) */
5363 {
5364 	device_t child;
5365 
5366 	if (!dev)
5367 		return;
5368 
5369 	print_device(dev, indent);
5370 
5371 	TAILQ_FOREACH(child, &dev->children, link) {
5372 		print_device_tree(child, indent+1);
5373 	}
5374 }
5375 
5376 static void
5377 print_driver_short(driver_t *driver, int indent)
5378 {
5379 	if (!driver)
5380 		return;
5381 
5382 	indentprintf(("driver %s: softc size = %zd\n",
5383 	    driver->name, driver->size));
5384 }
5385 
5386 static void
5387 print_driver(driver_t *driver, int indent)
5388 {
5389 	if (!driver)
5390 		return;
5391 
5392 	print_driver_short(driver, indent);
5393 }
5394 
5395 static void
5396 print_driver_list(driver_list_t drivers, int indent)
5397 {
5398 	driverlink_t driver;
5399 
5400 	TAILQ_FOREACH(driver, &drivers, link) {
5401 		print_driver(driver->driver, indent);
5402 	}
5403 }
5404 
5405 static void
5406 print_devclass_short(devclass_t dc, int indent)
5407 {
5408 	if ( !dc )
5409 		return;
5410 
5411 	indentprintf(("devclass %s: max units = %d\n", dc->name, dc->maxunit));
5412 }
5413 
5414 static void
5415 print_devclass(devclass_t dc, int indent)
5416 {
5417 	int i;
5418 
5419 	if ( !dc )
5420 		return;
5421 
5422 	print_devclass_short(dc, indent);
5423 	indentprintf(("Drivers:\n"));
5424 	print_driver_list(dc->drivers, indent+1);
5425 
5426 	indentprintf(("Devices:\n"));
5427 	for (i = 0; i < dc->maxunit; i++)
5428 		if (dc->devices[i])
5429 			print_device(dc->devices[i], indent+1);
5430 }
5431 
5432 void
5433 print_devclass_list_short(void)
5434 {
5435 	devclass_t dc;
5436 
5437 	printf("Short listing of devclasses, drivers & devices:\n");
5438 	TAILQ_FOREACH(dc, &devclasses, link) {
5439 		print_devclass_short(dc, 0);
5440 	}
5441 }
5442 
5443 void
5444 print_devclass_list(void)
5445 {
5446 	devclass_t dc;
5447 
5448 	printf("Full listing of devclasses, drivers & devices:\n");
5449 	TAILQ_FOREACH(dc, &devclasses, link) {
5450 		print_devclass(dc, 0);
5451 	}
5452 }
5453 
5454 #endif
5455 
5456 /*
5457  * User-space access to the device tree.
5458  *
5459  * We implement a small set of nodes:
5460  *
5461  * hw.bus			Single integer read method to obtain the
5462  *				current generation count.
5463  * hw.bus.devices		Reads the entire device tree in flat space.
5464  * hw.bus.rman			Resource manager interface
5465  *
5466  * We might like to add the ability to scan devclasses and/or drivers to
5467  * determine what else is currently loaded/available.
5468  */
5469 
5470 static int
5471 sysctl_bus_info(SYSCTL_HANDLER_ARGS)
5472 {
5473 	struct u_businfo	ubus;
5474 
5475 	ubus.ub_version = BUS_USER_VERSION;
5476 	ubus.ub_generation = bus_data_generation;
5477 
5478 	return (SYSCTL_OUT(req, &ubus, sizeof(ubus)));
5479 }
5480 SYSCTL_PROC(_hw_bus, OID_AUTO, info, CTLTYPE_STRUCT | CTLFLAG_RD |
5481     CTLFLAG_MPSAFE, NULL, 0, sysctl_bus_info, "S,u_businfo",
5482     "bus-related data");
5483 
5484 static int
5485 sysctl_devices(SYSCTL_HANDLER_ARGS)
5486 {
5487 	struct sbuf		sb;
5488 	int			*name = (int *)arg1;
5489 	u_int			namelen = arg2;
5490 	int			index;
5491 	device_t		dev;
5492 	struct u_device		*udev;
5493 	int			error;
5494 
5495 	if (namelen != 2)
5496 		return (EINVAL);
5497 
5498 	if (bus_data_generation_check(name[0]))
5499 		return (EINVAL);
5500 
5501 	index = name[1];
5502 
5503 	/*
5504 	 * Scan the list of devices, looking for the requested index.
5505 	 */
5506 	TAILQ_FOREACH(dev, &bus_data_devices, devlink) {
5507 		if (index-- == 0)
5508 			break;
5509 	}
5510 	if (dev == NULL)
5511 		return (ENOENT);
5512 
5513 	/*
5514 	 * Populate the return item, careful not to overflow the buffer.
5515 	 */
5516 	udev = malloc(sizeof(*udev), M_BUS, M_WAITOK | M_ZERO);
5517 	if (udev == NULL)
5518 		return (ENOMEM);
5519 	udev->dv_handle = (uintptr_t)dev;
5520 	udev->dv_parent = (uintptr_t)dev->parent;
5521 	udev->dv_devflags = dev->devflags;
5522 	udev->dv_flags = dev->flags;
5523 	udev->dv_state = dev->state;
5524 	sbuf_new(&sb, udev->dv_fields, sizeof(udev->dv_fields), SBUF_FIXEDLEN);
5525 	if (dev->nameunit != NULL)
5526 		sbuf_cat(&sb, dev->nameunit);
5527 	sbuf_putc(&sb, '\0');
5528 	if (dev->desc != NULL)
5529 		sbuf_cat(&sb, dev->desc);
5530 	sbuf_putc(&sb, '\0');
5531 	if (dev->driver != NULL)
5532 		sbuf_cat(&sb, dev->driver->name);
5533 	sbuf_putc(&sb, '\0');
5534 	bus_child_pnpinfo(dev, &sb);
5535 	sbuf_putc(&sb, '\0');
5536 	bus_child_location(dev, &sb);
5537 	sbuf_putc(&sb, '\0');
5538 	error = sbuf_finish(&sb);
5539 	if (error == 0)
5540 		error = SYSCTL_OUT(req, udev, sizeof(*udev));
5541 	sbuf_delete(&sb);
5542 	free(udev, M_BUS);
5543 	return (error);
5544 }
5545 
5546 SYSCTL_NODE(_hw_bus, OID_AUTO, devices,
5547     CTLFLAG_RD | CTLFLAG_NEEDGIANT, sysctl_devices,
5548     "system device tree");
5549 
5550 int
5551 bus_data_generation_check(int generation)
5552 {
5553 	if (generation != bus_data_generation)
5554 		return (1);
5555 
5556 	/* XXX generate optimised lists here? */
5557 	return (0);
5558 }
5559 
5560 void
5561 bus_data_generation_update(void)
5562 {
5563 	atomic_add_int(&bus_data_generation, 1);
5564 }
5565 
5566 int
5567 bus_free_resource(device_t dev, int type, struct resource *r)
5568 {
5569 	if (r == NULL)
5570 		return (0);
5571 	return (bus_release_resource(dev, type, rman_get_rid(r), r));
5572 }
5573 
5574 device_t
5575 device_lookup_by_name(const char *name)
5576 {
5577 	device_t dev;
5578 
5579 	TAILQ_FOREACH(dev, &bus_data_devices, devlink) {
5580 		if (dev->nameunit != NULL && strcmp(dev->nameunit, name) == 0)
5581 			return (dev);
5582 	}
5583 	return (NULL);
5584 }
5585 
5586 /*
5587  * /dev/devctl2 implementation.  The existing /dev/devctl device has
5588  * implicit semantics on open, so it could not be reused for this.
5589  * Another option would be to call this /dev/bus?
5590  */
5591 static int
5592 find_device(struct devreq *req, device_t *devp)
5593 {
5594 	device_t dev;
5595 
5596 	/*
5597 	 * First, ensure that the name is nul terminated.
5598 	 */
5599 	if (memchr(req->dr_name, '\0', sizeof(req->dr_name)) == NULL)
5600 		return (EINVAL);
5601 
5602 	/*
5603 	 * Second, try to find an attached device whose name matches
5604 	 * 'name'.
5605 	 */
5606 	dev = device_lookup_by_name(req->dr_name);
5607 	if (dev != NULL) {
5608 		*devp = dev;
5609 		return (0);
5610 	}
5611 
5612 	/* Finally, give device enumerators a chance. */
5613 	dev = NULL;
5614 	EVENTHANDLER_DIRECT_INVOKE(dev_lookup, req->dr_name, &dev);
5615 	if (dev == NULL)
5616 		return (ENOENT);
5617 	*devp = dev;
5618 	return (0);
5619 }
5620 
5621 static bool
5622 driver_exists(device_t bus, const char *driver)
5623 {
5624 	devclass_t dc;
5625 
5626 	for (dc = bus->devclass; dc != NULL; dc = dc->parent) {
5627 		if (devclass_find_driver_internal(dc, driver) != NULL)
5628 			return (true);
5629 	}
5630 	return (false);
5631 }
5632 
5633 static void
5634 device_gen_nomatch(device_t dev)
5635 {
5636 	device_t child;
5637 
5638 	if (dev->flags & DF_NEEDNOMATCH &&
5639 	    dev->state == DS_NOTPRESENT) {
5640 		BUS_PROBE_NOMATCH(dev->parent, dev);
5641 		devnomatch(dev);
5642 		dev->flags |= DF_DONENOMATCH;
5643 	}
5644 	dev->flags &= ~DF_NEEDNOMATCH;
5645 	TAILQ_FOREACH(child, &dev->children, link) {
5646 		device_gen_nomatch(child);
5647 	}
5648 }
5649 
5650 static void
5651 device_do_deferred_actions(void)
5652 {
5653 	devclass_t dc;
5654 	driverlink_t dl;
5655 
5656 	/*
5657 	 * Walk through the devclasses to find all the drivers we've tagged as
5658 	 * deferred during the freeze and call the driver added routines. They
5659 	 * have already been added to the lists in the background, so the driver
5660 	 * added routines that trigger a probe will have all the right bidders
5661 	 * for the probe auction.
5662 	 */
5663 	TAILQ_FOREACH(dc, &devclasses, link) {
5664 		TAILQ_FOREACH(dl, &dc->drivers, link) {
5665 			if (dl->flags & DL_DEFERRED_PROBE) {
5666 				devclass_driver_added(dc, dl->driver);
5667 				dl->flags &= ~DL_DEFERRED_PROBE;
5668 			}
5669 		}
5670 	}
5671 
5672 	/*
5673 	 * We also defer no-match events during a freeze. Walk the tree and
5674 	 * generate all the pent-up events that are still relevant.
5675 	 */
5676 	device_gen_nomatch(root_bus);
5677 	bus_data_generation_update();
5678 }
5679 
5680 static int
5681 devctl2_ioctl(struct cdev *cdev, u_long cmd, caddr_t data, int fflag,
5682     struct thread *td)
5683 {
5684 	struct devreq *req;
5685 	device_t dev;
5686 	int error, old;
5687 
5688 	/* Locate the device to control. */
5689 	mtx_lock(&Giant);
5690 	req = (struct devreq *)data;
5691 	switch (cmd) {
5692 	case DEV_ATTACH:
5693 	case DEV_DETACH:
5694 	case DEV_ENABLE:
5695 	case DEV_DISABLE:
5696 	case DEV_SUSPEND:
5697 	case DEV_RESUME:
5698 	case DEV_SET_DRIVER:
5699 	case DEV_CLEAR_DRIVER:
5700 	case DEV_RESCAN:
5701 	case DEV_DELETE:
5702 	case DEV_RESET:
5703 		error = priv_check(td, PRIV_DRIVER);
5704 		if (error == 0)
5705 			error = find_device(req, &dev);
5706 		break;
5707 	case DEV_FREEZE:
5708 	case DEV_THAW:
5709 		error = priv_check(td, PRIV_DRIVER);
5710 		break;
5711 	default:
5712 		error = ENOTTY;
5713 		break;
5714 	}
5715 	if (error) {
5716 		mtx_unlock(&Giant);
5717 		return (error);
5718 	}
5719 
5720 	/* Perform the requested operation. */
5721 	switch (cmd) {
5722 	case DEV_ATTACH:
5723 		if (device_is_attached(dev) && (dev->flags & DF_REBID) == 0)
5724 			error = EBUSY;
5725 		else if (!device_is_enabled(dev))
5726 			error = ENXIO;
5727 		else
5728 			error = device_probe_and_attach(dev);
5729 		break;
5730 	case DEV_DETACH:
5731 		if (!device_is_attached(dev)) {
5732 			error = ENXIO;
5733 			break;
5734 		}
5735 		if (!(req->dr_flags & DEVF_FORCE_DETACH)) {
5736 			error = device_quiesce(dev);
5737 			if (error)
5738 				break;
5739 		}
5740 		error = device_detach(dev);
5741 		break;
5742 	case DEV_ENABLE:
5743 		if (device_is_enabled(dev)) {
5744 			error = EBUSY;
5745 			break;
5746 		}
5747 
5748 		/*
5749 		 * If the device has been probed but not attached (e.g.
5750 		 * when it has been disabled by a loader hint), just
5751 		 * attach the device rather than doing a full probe.
5752 		 */
5753 		device_enable(dev);
5754 		if (device_is_alive(dev)) {
5755 			/*
5756 			 * If the device was disabled via a hint, clear
5757 			 * the hint.
5758 			 */
5759 			if (resource_disabled(dev->driver->name, dev->unit))
5760 				resource_unset_value(dev->driver->name,
5761 				    dev->unit, "disabled");
5762 			error = device_attach(dev);
5763 		} else
5764 			error = device_probe_and_attach(dev);
5765 		break;
5766 	case DEV_DISABLE:
5767 		if (!device_is_enabled(dev)) {
5768 			error = ENXIO;
5769 			break;
5770 		}
5771 
5772 		if (!(req->dr_flags & DEVF_FORCE_DETACH)) {
5773 			error = device_quiesce(dev);
5774 			if (error)
5775 				break;
5776 		}
5777 
5778 		/*
5779 		 * Force DF_FIXEDCLASS on around detach to preserve
5780 		 * the existing name.
5781 		 */
5782 		old = dev->flags;
5783 		dev->flags |= DF_FIXEDCLASS;
5784 		error = device_detach(dev);
5785 		if (!(old & DF_FIXEDCLASS))
5786 			dev->flags &= ~DF_FIXEDCLASS;
5787 		if (error == 0)
5788 			device_disable(dev);
5789 		break;
5790 	case DEV_SUSPEND:
5791 		if (device_is_suspended(dev)) {
5792 			error = EBUSY;
5793 			break;
5794 		}
5795 		if (device_get_parent(dev) == NULL) {
5796 			error = EINVAL;
5797 			break;
5798 		}
5799 		error = BUS_SUSPEND_CHILD(device_get_parent(dev), dev);
5800 		break;
5801 	case DEV_RESUME:
5802 		if (!device_is_suspended(dev)) {
5803 			error = EINVAL;
5804 			break;
5805 		}
5806 		if (device_get_parent(dev) == NULL) {
5807 			error = EINVAL;
5808 			break;
5809 		}
5810 		error = BUS_RESUME_CHILD(device_get_parent(dev), dev);
5811 		break;
5812 	case DEV_SET_DRIVER: {
5813 		devclass_t dc;
5814 		char driver[128];
5815 
5816 		error = copyinstr(req->dr_data, driver, sizeof(driver), NULL);
5817 		if (error)
5818 			break;
5819 		if (driver[0] == '\0') {
5820 			error = EINVAL;
5821 			break;
5822 		}
5823 		if (dev->devclass != NULL &&
5824 		    strcmp(driver, dev->devclass->name) == 0)
5825 			/* XXX: Could possibly force DF_FIXEDCLASS on? */
5826 			break;
5827 
5828 		/*
5829 		 * Scan drivers for this device's bus looking for at
5830 		 * least one matching driver.
5831 		 */
5832 		if (dev->parent == NULL) {
5833 			error = EINVAL;
5834 			break;
5835 		}
5836 		if (!driver_exists(dev->parent, driver)) {
5837 			error = ENOENT;
5838 			break;
5839 		}
5840 		dc = devclass_create(driver);
5841 		if (dc == NULL) {
5842 			error = ENOMEM;
5843 			break;
5844 		}
5845 
5846 		/* Detach device if necessary. */
5847 		if (device_is_attached(dev)) {
5848 			if (req->dr_flags & DEVF_SET_DRIVER_DETACH)
5849 				error = device_detach(dev);
5850 			else
5851 				error = EBUSY;
5852 			if (error)
5853 				break;
5854 		}
5855 
5856 		/* Clear any previously-fixed device class and unit. */
5857 		if (dev->flags & DF_FIXEDCLASS)
5858 			devclass_delete_device(dev->devclass, dev);
5859 		dev->flags |= DF_WILDCARD;
5860 		dev->unit = -1;
5861 
5862 		/* Force the new device class. */
5863 		error = devclass_add_device(dc, dev);
5864 		if (error)
5865 			break;
5866 		dev->flags |= DF_FIXEDCLASS;
5867 		error = device_probe_and_attach(dev);
5868 		break;
5869 	}
5870 	case DEV_CLEAR_DRIVER:
5871 		if (!(dev->flags & DF_FIXEDCLASS)) {
5872 			error = 0;
5873 			break;
5874 		}
5875 		if (device_is_attached(dev)) {
5876 			if (req->dr_flags & DEVF_CLEAR_DRIVER_DETACH)
5877 				error = device_detach(dev);
5878 			else
5879 				error = EBUSY;
5880 			if (error)
5881 				break;
5882 		}
5883 
5884 		dev->flags &= ~DF_FIXEDCLASS;
5885 		dev->flags |= DF_WILDCARD;
5886 		devclass_delete_device(dev->devclass, dev);
5887 		error = device_probe_and_attach(dev);
5888 		break;
5889 	case DEV_RESCAN:
5890 		if (!device_is_attached(dev)) {
5891 			error = ENXIO;
5892 			break;
5893 		}
5894 		error = BUS_RESCAN(dev);
5895 		break;
5896 	case DEV_DELETE: {
5897 		device_t parent;
5898 
5899 		parent = device_get_parent(dev);
5900 		if (parent == NULL) {
5901 			error = EINVAL;
5902 			break;
5903 		}
5904 		if (!(req->dr_flags & DEVF_FORCE_DELETE)) {
5905 			if (bus_child_present(dev) != 0) {
5906 				error = EBUSY;
5907 				break;
5908 			}
5909 		}
5910 
5911 		error = device_delete_child(parent, dev);
5912 		break;
5913 	}
5914 	case DEV_FREEZE:
5915 		if (device_frozen)
5916 			error = EBUSY;
5917 		else
5918 			device_frozen = true;
5919 		break;
5920 	case DEV_THAW:
5921 		if (!device_frozen)
5922 			error = EBUSY;
5923 		else {
5924 			device_do_deferred_actions();
5925 			device_frozen = false;
5926 		}
5927 		break;
5928 	case DEV_RESET:
5929 		if ((req->dr_flags & ~(DEVF_RESET_DETACH)) != 0) {
5930 			error = EINVAL;
5931 			break;
5932 		}
5933 		error = BUS_RESET_CHILD(device_get_parent(dev), dev,
5934 		    req->dr_flags);
5935 		break;
5936 	}
5937 	mtx_unlock(&Giant);
5938 	return (error);
5939 }
5940 
5941 static struct cdevsw devctl2_cdevsw = {
5942 	.d_version =	D_VERSION,
5943 	.d_ioctl =	devctl2_ioctl,
5944 	.d_name =	"devctl2",
5945 };
5946 
5947 static void
5948 devctl2_init(void)
5949 {
5950 	make_dev_credf(MAKEDEV_ETERNAL, &devctl2_cdevsw, 0, NULL,
5951 	    UID_ROOT, GID_WHEEL, 0600, "devctl2");
5952 }
5953 
5954 /*
5955  * APIs to manage deprecation and obsolescence.
5956  */
5957 static int obsolete_panic = 0;
5958 SYSCTL_INT(_debug, OID_AUTO, obsolete_panic, CTLFLAG_RWTUN, &obsolete_panic, 0,
5959     "Panic when obsolete features are used (0 = never, 1 = if osbolete, "
5960     "2 = if deprecated)");
5961 
5962 static void
5963 gone_panic(int major, int running, const char *msg)
5964 {
5965 	switch (obsolete_panic)
5966 	{
5967 	case 0:
5968 		return;
5969 	case 1:
5970 		if (running < major)
5971 			return;
5972 		/* FALLTHROUGH */
5973 	default:
5974 		panic("%s", msg);
5975 	}
5976 }
5977 
5978 void
5979 _gone_in(int major, const char *msg)
5980 {
5981 	gone_panic(major, P_OSREL_MAJOR(__FreeBSD_version), msg);
5982 	if (P_OSREL_MAJOR(__FreeBSD_version) >= major)
5983 		printf("Obsolete code will be removed soon: %s\n", msg);
5984 	else
5985 		printf("Deprecated code (to be removed in FreeBSD %d): %s\n",
5986 		    major, msg);
5987 }
5988 
5989 void
5990 _gone_in_dev(device_t dev, int major, const char *msg)
5991 {
5992 	gone_panic(major, P_OSREL_MAJOR(__FreeBSD_version), msg);
5993 	if (P_OSREL_MAJOR(__FreeBSD_version) >= major)
5994 		device_printf(dev,
5995 		    "Obsolete code will be removed soon: %s\n", msg);
5996 	else
5997 		device_printf(dev,
5998 		    "Deprecated code (to be removed in FreeBSD %d): %s\n",
5999 		    major, msg);
6000 }
6001 
6002 #ifdef DDB
6003 DB_SHOW_COMMAND(device, db_show_device)
6004 {
6005 	device_t dev;
6006 
6007 	if (!have_addr)
6008 		return;
6009 
6010 	dev = (device_t)addr;
6011 
6012 	db_printf("name:    %s\n", device_get_nameunit(dev));
6013 	db_printf("  driver:  %s\n", DRIVERNAME(dev->driver));
6014 	db_printf("  class:   %s\n", DEVCLANAME(dev->devclass));
6015 	db_printf("  addr:    %p\n", dev);
6016 	db_printf("  parent:  %p\n", dev->parent);
6017 	db_printf("  softc:   %p\n", dev->softc);
6018 	db_printf("  ivars:   %p\n", dev->ivars);
6019 }
6020 
6021 DB_SHOW_ALL_COMMAND(devices, db_show_all_devices)
6022 {
6023 	device_t dev;
6024 
6025 	TAILQ_FOREACH(dev, &bus_data_devices, devlink) {
6026 		db_show_device((db_expr_t)dev, true, count, modif);
6027 	}
6028 }
6029 #endif
6030