diff --git a/sys/kern/subr_bus.c b/sys/kern/subr_bus.c
index d271013b4b1f..d22dd4868ff6 100644
--- a/sys/kern/subr_bus.c
+++ b/sys/kern/subr_bus.c
@@ -1,6245 +1,6242 @@
 /*-
  * SPDX-License-Identifier: BSD-2-Clause
  *
  * Copyright (c) 1997,1998,2003 Doug Rabson
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
 
 #include <sys/cdefs.h>
 #include "opt_bus.h"
 #include "opt_ddb.h"
 #include "opt_iommu.h"
 
 #include <sys/param.h>
 #include <sys/conf.h>
 #include <sys/domainset.h>
 #include <sys/eventhandler.h>
 #include <sys/jail.h>
 #include <sys/lock.h>
 #include <sys/kernel.h>
 #include <sys/limits.h>
 #include <sys/malloc.h>
 #include <sys/module.h>
 #include <sys/mutex.h>
 #include <sys/priv.h>
 #include <machine/bus.h>
 #include <sys/random.h>
 #include <sys/refcount.h>
 #include <sys/rman.h>
 #include <sys/sbuf.h>
 #include <sys/smp.h>
 #include <sys/sysctl.h>
 #include <sys/systm.h>
 #include <sys/bus.h>
 #include <sys/cpuset.h>
 #ifdef INTRNG
 #include <sys/intr.h>
 #endif
 
 #include <net/vnet.h>
 
 #include <machine/cpu.h>
 #include <machine/stdarg.h>
 
 #include <vm/uma.h>
 #include <vm/vm.h>
 
 #include <dev/iommu/iommu.h>
 
 #include <ddb/ddb.h>
 
 SYSCTL_NODE(_hw, OID_AUTO, bus, CTLFLAG_RW | CTLFLAG_MPSAFE, NULL,
     NULL);
 SYSCTL_ROOT_NODE(OID_AUTO, dev, CTLFLAG_RW | CTLFLAG_MPSAFE, NULL,
     NULL);
 
 static bool disable_failed_devs = false;
 SYSCTL_BOOL(_hw_bus, OID_AUTO, disable_failed_devices, CTLFLAG_RWTUN, &disable_failed_devs,
     0, "Do not retry attaching devices that return an error from DEVICE_ATTACH the first time");
 
 /*
  * Used to attach drivers to devclasses.
  */
 typedef struct driverlink *driverlink_t;
 struct driverlink {
 	kobj_class_t	driver;
 	TAILQ_ENTRY(driverlink) link;	/* list of drivers in devclass */
 	int		pass;
 	int		flags;
 #define DL_DEFERRED_PROBE	1	/* Probe deferred on this */
 	TAILQ_ENTRY(driverlink) passlink;
 };
 
 /*
  * Forward declarations
  */
 typedef TAILQ_HEAD(devclass_list, devclass) devclass_list_t;
 typedef TAILQ_HEAD(driver_list, driverlink) driver_list_t;
 typedef TAILQ_HEAD(device_list, _device) device_list_t;
 
 struct devclass {
 	TAILQ_ENTRY(devclass) link;
 	devclass_t	parent;		/* parent in devclass hierarchy */
 	driver_list_t	drivers;	/* bus devclasses store drivers for bus */
 	char		*name;
 	device_t	*devices;	/* array of devices indexed by unit */
 	int		maxunit;	/* size of devices array */
 	int		flags;
 #define DC_HAS_CHILDREN		1
 
 	struct sysctl_ctx_list sysctl_ctx;
 	struct sysctl_oid *sysctl_tree;
 };
 
 struct device_prop_elm {
 	const char *name;
 	void *val;
 	void *dtr_ctx;
 	device_prop_dtr_t dtr;
 	LIST_ENTRY(device_prop_elm) link;
 };
 
 static void device_destroy_props(device_t dev);
 
 /**
  * @brief Implementation of _device.
  *
  * The structure is named "_device" instead of "device" to avoid type confusion
  * caused by other subsystems defining a (struct device).
  */
 struct _device {
 	/*
 	 * A device is a kernel object. The first field must be the
 	 * current ops table for the object.
 	 */
 	KOBJ_FIELDS;
 
 	/*
 	 * Device hierarchy.
 	 */
 	TAILQ_ENTRY(_device)	link;	/**< list of devices in parent */
 	TAILQ_ENTRY(_device)	devlink; /**< global device list membership */
 	device_t	parent;		/**< parent of this device  */
 	device_list_t	children;	/**< list of child devices */
 
 	/*
 	 * Details of this device.
 	 */
 	driver_t	*driver;	/**< current driver */
 	devclass_t	devclass;	/**< current device class */
 	int		unit;		/**< current unit number */
 	char*		nameunit;	/**< name+unit e.g. foodev0 */
 	char*		desc;		/**< driver specific description */
 	u_int		busy;		/**< count of calls to device_busy() */
 	device_state_t	state;		/**< current device state  */
 	uint32_t	devflags;	/**< api level flags for device_get_flags() */
 	u_int		flags;		/**< internal device flags  */
 	u_int	order;			/**< order from device_add_child_ordered() */
 	void	*ivars;			/**< instance variables  */
 	void	*softc;			/**< current driver's variables  */
 	LIST_HEAD(, device_prop_elm) props;
 
 	struct sysctl_ctx_list sysctl_ctx; /**< state for sysctl variables  */
 	struct sysctl_oid *sysctl_tree;	/**< state for sysctl variables */
 };
 
 static MALLOC_DEFINE(M_BUS, "bus", "Bus data structures");
 static MALLOC_DEFINE(M_BUS_SC, "bus-sc", "Bus data structures, softc");
 
 EVENTHANDLER_LIST_DEFINE(device_attach);
 EVENTHANDLER_LIST_DEFINE(device_detach);
 EVENTHANDLER_LIST_DEFINE(device_nomatch);
 EVENTHANDLER_LIST_DEFINE(dev_lookup);
 
 static void devctl2_init(void);
 static bool device_frozen;
 
 #define DRIVERNAME(d)	((d)? d->name : "no driver")
 #define DEVCLANAME(d)	((d)? d->name : "no devclass")
 
 #ifdef BUS_DEBUG
 
 static int bus_debug = 1;
 SYSCTL_INT(_debug, OID_AUTO, bus_debug, CTLFLAG_RWTUN, &bus_debug, 0,
     "Bus debug level");
 #define PDEBUG(a)	if (bus_debug) {printf("%s:%d: ", __func__, __LINE__), printf a; printf("\n");}
 #define DEVICENAME(d)	((d)? device_get_name(d): "no device")
 
 /**
  * Produce the indenting, indent*2 spaces plus a '.' ahead of that to
  * prevent syslog from deleting initial spaces
  */
 #define indentprintf(p)	do { int iJ; printf("."); for (iJ=0; iJ<indent; iJ++) printf("  "); printf p ; } while (0)
 
 static void print_device_short(device_t dev, int indent);
 static void print_device(device_t dev, int indent);
 void print_device_tree_short(device_t dev, int indent);
 void print_device_tree(device_t dev, int indent);
 static void print_driver_short(driver_t *driver, int indent);
 static void print_driver(driver_t *driver, int indent);
 static void print_driver_list(driver_list_t drivers, int indent);
 static void print_devclass_short(devclass_t dc, int indent);
 static void print_devclass(devclass_t dc, int indent);
 void print_devclass_list_short(void);
 void print_devclass_list(void);
 
 #else
 /* Make the compiler ignore the function calls */
 #define PDEBUG(a)			/* nop */
 #define DEVICENAME(d)			/* nop */
 
 #define print_device_short(d,i)		/* nop */
 #define print_device(d,i)		/* nop */
 #define print_device_tree_short(d,i)	/* nop */
 #define print_device_tree(d,i)		/* nop */
 #define print_driver_short(d,i)		/* nop */
 #define print_driver(d,i)		/* nop */
 #define print_driver_list(d,i)		/* nop */
 #define print_devclass_short(d,i)	/* nop */
 #define print_devclass(d,i)		/* nop */
 #define print_devclass_list_short()	/* nop */
 #define print_devclass_list()		/* nop */
 #endif
 
 /*
  * dev sysctl tree
  */
 
 enum {
 	DEVCLASS_SYSCTL_PARENT,
 };
 
 static int
 devclass_sysctl_handler(SYSCTL_HANDLER_ARGS)
 {
 	devclass_t dc = (devclass_t)arg1;
 	const char *value;
 
 	switch (arg2) {
 	case DEVCLASS_SYSCTL_PARENT:
 		value = dc->parent ? dc->parent->name : "";
 		break;
 	default:
 		return (EINVAL);
 	}
 	return (SYSCTL_OUT_STR(req, value));
 }
 
 static void
 devclass_sysctl_init(devclass_t dc)
 {
 	if (dc->sysctl_tree != NULL)
 		return;
 	sysctl_ctx_init(&dc->sysctl_ctx);
 	dc->sysctl_tree = SYSCTL_ADD_NODE(&dc->sysctl_ctx,
 	    SYSCTL_STATIC_CHILDREN(_dev), OID_AUTO, dc->name,
 	    CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "");
 	SYSCTL_ADD_PROC(&dc->sysctl_ctx, SYSCTL_CHILDREN(dc->sysctl_tree),
 	    OID_AUTO, "%parent",
 	    CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
 	    dc, DEVCLASS_SYSCTL_PARENT, devclass_sysctl_handler, "A",
 	    "parent class");
 }
 
 enum {
 	DEVICE_SYSCTL_DESC,
 	DEVICE_SYSCTL_DRIVER,
 	DEVICE_SYSCTL_LOCATION,
 	DEVICE_SYSCTL_PNPINFO,
 	DEVICE_SYSCTL_PARENT,
 	DEVICE_SYSCTL_IOMMU,
 };
 
 static int
 device_sysctl_handler(SYSCTL_HANDLER_ARGS)
 {
 	struct sbuf sb;
 	device_t dev = (device_t)arg1;
 	device_t iommu;
 	int error;
 	uint16_t rid;
 	const char *c;
 
 	sbuf_new_for_sysctl(&sb, NULL, 1024, req);
 	sbuf_clear_flags(&sb, SBUF_INCLUDENUL);
 	bus_topo_lock();
 	switch (arg2) {
 	case DEVICE_SYSCTL_DESC:
 		sbuf_cat(&sb, dev->desc ? dev->desc : "");
 		break;
 	case DEVICE_SYSCTL_DRIVER:
 		sbuf_cat(&sb, dev->driver ? dev->driver->name : "");
 		break;
 	case DEVICE_SYSCTL_LOCATION:
 		bus_child_location(dev, &sb);
 		break;
 	case DEVICE_SYSCTL_PNPINFO:
 		bus_child_pnpinfo(dev, &sb);
 		break;
 	case DEVICE_SYSCTL_PARENT:
 		sbuf_cat(&sb, dev->parent ? dev->parent->nameunit : "");
 		break;
 	case DEVICE_SYSCTL_IOMMU:
 		iommu = NULL;
 		error = device_get_prop(dev, DEV_PROP_NAME_IOMMU,
 		    (void **)&iommu);
 		c = "";
 		if (error == 0 && iommu != NULL) {
 			sbuf_printf(&sb, "unit=%s", device_get_nameunit(iommu));
 			c = " ";
 		}
 		rid = 0;
 #ifdef IOMMU
 		iommu_get_requester(dev, &rid);
 #endif
 		if (rid != 0)
 			sbuf_printf(&sb, "%srid=%#x", c, rid);
 		break;
 	default:
 		error = EINVAL;
 		goto out;
 	}
 	error = sbuf_finish(&sb);
 out:
 	bus_topo_unlock();
 	sbuf_delete(&sb);
 	return (error);
 }
 
 static void
 device_sysctl_init(device_t dev)
 {
 	devclass_t dc = dev->devclass;
 	int domain;
 
 	if (dev->sysctl_tree != NULL)
 		return;
 	devclass_sysctl_init(dc);
 	sysctl_ctx_init(&dev->sysctl_ctx);
 	dev->sysctl_tree = SYSCTL_ADD_NODE_WITH_LABEL(&dev->sysctl_ctx,
 	    SYSCTL_CHILDREN(dc->sysctl_tree), OID_AUTO,
 	    dev->nameunit + strlen(dc->name),
 	    CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "", "device_index");
 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
 	    OID_AUTO, "%desc", CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
 	    dev, DEVICE_SYSCTL_DESC, device_sysctl_handler, "A",
 	    "device description");
 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
 	    OID_AUTO, "%driver",
 	    CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
 	    dev, DEVICE_SYSCTL_DRIVER, device_sysctl_handler, "A",
 	    "device driver name");
 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
 	    OID_AUTO, "%location",
 	    CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
 	    dev, DEVICE_SYSCTL_LOCATION, device_sysctl_handler, "A",
 	    "device location relative to parent");
 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
 	    OID_AUTO, "%pnpinfo",
 	    CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
 	    dev, DEVICE_SYSCTL_PNPINFO, device_sysctl_handler, "A",
 	    "device identification");
 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
 	    OID_AUTO, "%parent",
 	    CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
 	    dev, DEVICE_SYSCTL_PARENT, device_sysctl_handler, "A",
 	    "parent device");
 	SYSCTL_ADD_PROC(&dev->sysctl_ctx, SYSCTL_CHILDREN(dev->sysctl_tree),
 	    OID_AUTO, "%iommu",
 	    CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
 	    dev, DEVICE_SYSCTL_IOMMU, device_sysctl_handler, "A",
 	    "iommu unit handling the device requests");
 	if (bus_get_domain(dev, &domain) == 0)
 		SYSCTL_ADD_INT(&dev->sysctl_ctx,
 		    SYSCTL_CHILDREN(dev->sysctl_tree), OID_AUTO, "%domain",
 		    CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, domain, "NUMA domain");
 }
 
 static void
 device_sysctl_update(device_t dev)
 {
 	devclass_t dc = dev->devclass;
 
 	if (dev->sysctl_tree == NULL)
 		return;
 	sysctl_rename_oid(dev->sysctl_tree, dev->nameunit + strlen(dc->name));
 }
 
 static void
 device_sysctl_fini(device_t dev)
 {
 	if (dev->sysctl_tree == NULL)
 		return;
 	sysctl_ctx_free(&dev->sysctl_ctx);
 	dev->sysctl_tree = NULL;
 }
 
 static struct device_list bus_data_devices;
 static int bus_data_generation = 1;
 
 static kobj_method_t null_methods[] = {
 	KOBJMETHOD_END
 };
 
 DEFINE_CLASS(null, null_methods, 0);
 
 void
 bus_topo_assert(void)
 {
 
 	GIANT_REQUIRED;	
 }
 
 struct mtx *
 bus_topo_mtx(void)
 {
 
 	return (&Giant);
 }
 
 void
 bus_topo_lock(void)
 {
 
 	mtx_lock(bus_topo_mtx());
 }
 
 void
 bus_topo_unlock(void)
 {
 
 	mtx_unlock(bus_topo_mtx());
 }
 
 /*
  * Bus pass implementation
  */
 
 static driver_list_t passes = TAILQ_HEAD_INITIALIZER(passes);
 int bus_current_pass = BUS_PASS_ROOT;
 
 /**
  * @internal
  * @brief Register the pass level of a new driver attachment
  *
  * Register a new driver attachment's pass level.  If no driver
  * attachment with the same pass level has been added, then @p new
  * will be added to the global passes list.
  *
  * @param new		the new driver attachment
  */
 static void
 driver_register_pass(struct driverlink *new)
 {
 	struct driverlink *dl;
 
 	/* We only consider pass numbers during boot. */
 	if (bus_current_pass == BUS_PASS_DEFAULT)
 		return;
 
 	/*
 	 * Walk the passes list.  If we already know about this pass
 	 * then there is nothing to do.  If we don't, then insert this
 	 * driver link into the list.
 	 */
 	TAILQ_FOREACH(dl, &passes, passlink) {
 		if (dl->pass < new->pass)
 			continue;
 		if (dl->pass == new->pass)
 			return;
 		TAILQ_INSERT_BEFORE(dl, new, passlink);
 		return;
 	}
 	TAILQ_INSERT_TAIL(&passes, new, passlink);
 }
 
 /**
  * @brief Raise the current bus pass
  *
  * Raise the current bus pass level to @p pass.  Call the BUS_NEW_PASS()
  * method on the root bus to kick off a new device tree scan for each
  * new pass level that has at least one driver.
  */
 void
 bus_set_pass(int pass)
 {
 	struct driverlink *dl;
 
 	if (bus_current_pass > pass)
 		panic("Attempt to lower bus pass level");
 
 	TAILQ_FOREACH(dl, &passes, passlink) {
 		/* Skip pass values below the current pass level. */
 		if (dl->pass <= bus_current_pass)
 			continue;
 
 		/*
 		 * Bail once we hit a driver with a pass level that is
 		 * too high.
 		 */
 		if (dl->pass > pass)
 			break;
 
 		/*
 		 * Raise the pass level to the next level and rescan
 		 * the tree.
 		 */
 		bus_current_pass = dl->pass;
 		BUS_NEW_PASS(root_bus);
 	}
 
 	/*
 	 * If there isn't a driver registered for the requested pass,
 	 * then bus_current_pass might still be less than 'pass'.  Set
 	 * it to 'pass' in that case.
 	 */
 	if (bus_current_pass < pass)
 		bus_current_pass = pass;
 	KASSERT(bus_current_pass == pass, ("Failed to update bus pass level"));
 }
 
 /*
  * Devclass implementation
  */
 
 static devclass_list_t devclasses = TAILQ_HEAD_INITIALIZER(devclasses);
 
 /**
  * @internal
  * @brief Find or create a device class
  *
  * If a device class with the name @p classname exists, return it,
  * otherwise if @p create is non-zero create and return a new device
  * class.
  *
  * If @p parentname is non-NULL, the parent of the devclass is set to
  * the devclass of that name.
  *
  * @param classname	the devclass name to find or create
  * @param parentname	the parent devclass name or @c NULL
  * @param create	non-zero to create a devclass
  */
 static devclass_t
 devclass_find_internal(const char *classname, const char *parentname,
 		       int create)
 {
 	devclass_t dc;
 
 	PDEBUG(("looking for %s", classname));
 	if (!classname)
 		return (NULL);
 
 	TAILQ_FOREACH(dc, &devclasses, link) {
 		if (!strcmp(dc->name, classname))
 			break;
 	}
 
 	if (create && !dc) {
 		PDEBUG(("creating %s", classname));
 		dc = malloc(sizeof(struct devclass) + strlen(classname) + 1,
 		    M_BUS, M_NOWAIT | M_ZERO);
 		if (!dc)
 			return (NULL);
 		dc->parent = NULL;
 		dc->name = (char*) (dc + 1);
 		strcpy(dc->name, classname);
 		TAILQ_INIT(&dc->drivers);
 		TAILQ_INSERT_TAIL(&devclasses, dc, link);
 
 		bus_data_generation_update();
 	}
 
 	/*
 	 * If a parent class is specified, then set that as our parent so
 	 * that this devclass will support drivers for the parent class as
 	 * well.  If the parent class has the same name don't do this though
 	 * as it creates a cycle that can trigger an infinite loop in
 	 * device_probe_child() if a device exists for which there is no
 	 * suitable driver.
 	 */
 	if (parentname && dc && !dc->parent &&
 	    strcmp(classname, parentname) != 0) {
 		dc->parent = devclass_find_internal(parentname, NULL, TRUE);
 		dc->parent->flags |= DC_HAS_CHILDREN;
 	}
 
 	return (dc);
 }
 
 /**
  * @brief Create a device class
  *
  * If a device class with the name @p classname exists, return it,
  * otherwise create and return a new device class.
  *
  * @param classname	the devclass name to find or create
  */
 devclass_t
 devclass_create(const char *classname)
 {
 	return (devclass_find_internal(classname, NULL, TRUE));
 }
 
 /**
  * @brief Find a device class
  *
  * If a device class with the name @p classname exists, return it,
  * otherwise return @c NULL.
  *
  * @param classname	the devclass name to find
  */
 devclass_t
 devclass_find(const char *classname)
 {
 	return (devclass_find_internal(classname, NULL, FALSE));
 }
 
 /**
  * @brief Register that a device driver has been added to a devclass
  *
  * Register that a device driver has been added to a devclass.  This
  * is called by devclass_add_driver to accomplish the recursive
  * notification of all the children classes of dc, as well as dc.
  * Each layer will have BUS_DRIVER_ADDED() called for all instances of
  * the devclass.
  *
  * We do a full search here of the devclass list at each iteration
  * level to save storing children-lists in the devclass structure.  If
  * we ever move beyond a few dozen devices doing this, we may need to
  * reevaluate...
  *
  * @param dc		the devclass to edit
  * @param driver	the driver that was just added
  */
 static void
 devclass_driver_added(devclass_t dc, driver_t *driver)
 {
 	devclass_t parent;
 	int i;
 
 	/*
 	 * Call BUS_DRIVER_ADDED for any existing buses in this class.
 	 */
 	for (i = 0; i < dc->maxunit; i++)
 		if (dc->devices[i] && device_is_attached(dc->devices[i]))
 			BUS_DRIVER_ADDED(dc->devices[i], driver);
 
 	/*
 	 * Walk through the children classes.  Since we only keep a
 	 * single parent pointer around, we walk the entire list of
 	 * devclasses looking for children.  We set the
 	 * DC_HAS_CHILDREN flag when a child devclass is created on
 	 * the parent, so we only walk the list for those devclasses
 	 * that have children.
 	 */
 	if (!(dc->flags & DC_HAS_CHILDREN))
 		return;
 	parent = dc;
 	TAILQ_FOREACH(dc, &devclasses, link) {
 		if (dc->parent == parent)
 			devclass_driver_added(dc, driver);
 	}
 }
 
 static void
 device_handle_nomatch(device_t dev)
 {
 	BUS_PROBE_NOMATCH(dev->parent, dev);
 	EVENTHANDLER_DIRECT_INVOKE(device_nomatch, dev);
 	dev->flags |= DF_DONENOMATCH;
 }
 
 /**
  * @brief Add a device driver to a device class
  *
  * Add a device driver to a devclass. This is normally called
  * automatically by DRIVER_MODULE(). The BUS_DRIVER_ADDED() method of
  * all devices in the devclass will be called to allow them to attempt
  * to re-probe any unmatched children.
  *
  * @param dc		the devclass to edit
  * @param driver	the driver to register
  */
 int
 devclass_add_driver(devclass_t dc, driver_t *driver, int pass, devclass_t *dcp)
 {
 	driverlink_t dl;
 	devclass_t child_dc;
 	const char *parentname;
 
 	PDEBUG(("%s", DRIVERNAME(driver)));
 
 	/* Don't allow invalid pass values. */
 	if (pass <= BUS_PASS_ROOT)
 		return (EINVAL);
 
 	dl = malloc(sizeof *dl, M_BUS, M_NOWAIT|M_ZERO);
 	if (!dl)
 		return (ENOMEM);
 
 	/*
 	 * Compile the driver's methods. Also increase the reference count
 	 * so that the class doesn't get freed when the last instance
 	 * goes. This means we can safely use static methods and avoids a
 	 * double-free in devclass_delete_driver.
 	 */
 	kobj_class_compile((kobj_class_t) driver);
 
 	/*
 	 * If the driver has any base classes, make the
 	 * devclass inherit from the devclass of the driver's
 	 * first base class. This will allow the system to
 	 * search for drivers in both devclasses for children
 	 * of a device using this driver.
 	 */
 	if (driver->baseclasses)
 		parentname = driver->baseclasses[0]->name;
 	else
 		parentname = NULL;
 	child_dc = devclass_find_internal(driver->name, parentname, TRUE);
 	if (dcp != NULL)
 		*dcp = child_dc;
 
 	dl->driver = driver;
 	TAILQ_INSERT_TAIL(&dc->drivers, dl, link);
 	driver->refs++;		/* XXX: kobj_mtx */
 	dl->pass = pass;
 	driver_register_pass(dl);
 
 	if (device_frozen) {
 		dl->flags |= DL_DEFERRED_PROBE;
 	} else {
 		devclass_driver_added(dc, driver);
 	}
 	bus_data_generation_update();
 	return (0);
 }
 
 /**
  * @brief Register that a device driver has been deleted from a devclass
  *
  * Register that a device driver has been removed from a devclass.
  * This is called by devclass_delete_driver to accomplish the
  * recursive notification of all the children classes of busclass, as
  * well as busclass.  Each layer will attempt to detach the driver
  * from any devices that are children of the bus's devclass.  The function
  * will return an error if a device fails to detach.
  *
  * We do a full search here of the devclass list at each iteration
  * level to save storing children-lists in the devclass structure.  If
  * we ever move beyond a few dozen devices doing this, we may need to
  * reevaluate...
  *
  * @param busclass	the devclass of the parent bus
  * @param dc		the devclass of the driver being deleted
  * @param driver	the driver being deleted
  */
 static int
 devclass_driver_deleted(devclass_t busclass, devclass_t dc, driver_t *driver)
 {
 	devclass_t parent;
 	device_t dev;
 	int error, i;
 
 	/*
 	 * Disassociate from any devices.  We iterate through all the
 	 * devices in the devclass of the driver and detach any which are
 	 * using the driver and which have a parent in the devclass which
 	 * we are deleting from.
 	 *
 	 * Note that since a driver can be in multiple devclasses, we
 	 * should not detach devices which are not children of devices in
 	 * the affected devclass.
 	 *
 	 * If we're frozen, we don't generate NOMATCH events. Mark to
 	 * generate later.
 	 */
 	for (i = 0; i < dc->maxunit; i++) {
 		if (dc->devices[i]) {
 			dev = dc->devices[i];
 			if (dev->driver == driver && dev->parent &&
 			    dev->parent->devclass == busclass) {
 				if ((error = device_detach(dev)) != 0)
 					return (error);
 				if (device_frozen) {
 					dev->flags &= ~DF_DONENOMATCH;
 					dev->flags |= DF_NEEDNOMATCH;
 				} else {
 					device_handle_nomatch(dev);
 				}
 			}
 		}
 	}
 
 	/*
 	 * Walk through the children classes.  Since we only keep a
 	 * single parent pointer around, we walk the entire list of
 	 * devclasses looking for children.  We set the
 	 * DC_HAS_CHILDREN flag when a child devclass is created on
 	 * the parent, so we only walk the list for those devclasses
 	 * that have children.
 	 */
 	if (!(busclass->flags & DC_HAS_CHILDREN))
 		return (0);
 	parent = busclass;
 	TAILQ_FOREACH(busclass, &devclasses, link) {
 		if (busclass->parent == parent) {
 			error = devclass_driver_deleted(busclass, dc, driver);
 			if (error)
 				return (error);
 		}
 	}
 	return (0);
 }
 
 /**
  * @brief Delete a device driver from a device class
  *
  * Delete a device driver from a devclass. This is normally called
  * automatically by DRIVER_MODULE().
  *
  * If the driver is currently attached to any devices,
  * devclass_delete_driver() will first attempt to detach from each
  * device. If one of the detach calls fails, the driver will not be
  * deleted.
  *
  * @param dc		the devclass to edit
  * @param driver	the driver to unregister
  */
 int
 devclass_delete_driver(devclass_t busclass, driver_t *driver)
 {
 	devclass_t dc = devclass_find(driver->name);
 	driverlink_t dl;
 	int error;
 
 	PDEBUG(("%s from devclass %s", driver->name, DEVCLANAME(busclass)));
 
 	if (!dc)
 		return (0);
 
 	/*
 	 * Find the link structure in the bus' list of drivers.
 	 */
 	TAILQ_FOREACH(dl, &busclass->drivers, link) {
 		if (dl->driver == driver)
 			break;
 	}
 
 	if (!dl) {
 		PDEBUG(("%s not found in %s list", driver->name,
 		    busclass->name));
 		return (ENOENT);
 	}
 
 	error = devclass_driver_deleted(busclass, dc, driver);
 	if (error != 0)
 		return (error);
 
 	TAILQ_REMOVE(&busclass->drivers, dl, link);
 	free(dl, M_BUS);
 
 	/* XXX: kobj_mtx */
 	driver->refs--;
 	if (driver->refs == 0)
 		kobj_class_free((kobj_class_t) driver);
 
 	bus_data_generation_update();
 	return (0);
 }
 
 /**
  * @brief Quiesces a set of device drivers from a device class
  *
  * Quiesce a device driver from a devclass. This is normally called
  * automatically by DRIVER_MODULE().
  *
  * If the driver is currently attached to any devices,
  * devclass_quiesece_driver() will first attempt to quiesce each
  * device.
  *
  * @param dc		the devclass to edit
  * @param driver	the driver to unregister
  */
 static int
 devclass_quiesce_driver(devclass_t busclass, driver_t *driver)
 {
 	devclass_t dc = devclass_find(driver->name);
 	driverlink_t dl;
 	device_t dev;
 	int i;
 	int error;
 
 	PDEBUG(("%s from devclass %s", driver->name, DEVCLANAME(busclass)));
 
 	if (!dc)
 		return (0);
 
 	/*
 	 * Find the link structure in the bus' list of drivers.
 	 */
 	TAILQ_FOREACH(dl, &busclass->drivers, link) {
 		if (dl->driver == driver)
 			break;
 	}
 
 	if (!dl) {
 		PDEBUG(("%s not found in %s list", driver->name,
 		    busclass->name));
 		return (ENOENT);
 	}
 
 	/*
 	 * Quiesce all devices.  We iterate through all the devices in
 	 * the devclass of the driver and quiesce any which are using
 	 * the driver and which have a parent in the devclass which we
 	 * are quiescing.
 	 *
 	 * Note that since a driver can be in multiple devclasses, we
 	 * should not quiesce devices which are not children of
 	 * devices in the affected devclass.
 	 */
 	for (i = 0; i < dc->maxunit; i++) {
 		if (dc->devices[i]) {
 			dev = dc->devices[i];
 			if (dev->driver == driver && dev->parent &&
 			    dev->parent->devclass == busclass) {
 				if ((error = device_quiesce(dev)) != 0)
 					return (error);
 			}
 		}
 	}
 
 	return (0);
 }
 
 /**
  * @internal
  */
 static driverlink_t
 devclass_find_driver_internal(devclass_t dc, const char *classname)
 {
 	driverlink_t dl;
 
 	PDEBUG(("%s in devclass %s", classname, DEVCLANAME(dc)));
 
 	TAILQ_FOREACH(dl, &dc->drivers, link) {
 		if (!strcmp(dl->driver->name, classname))
 			return (dl);
 	}
 
 	PDEBUG(("not found"));
 	return (NULL);
 }
 
 /**
  * @brief Return the name of the devclass
  */
 const char *
 devclass_get_name(devclass_t dc)
 {
 	return (dc->name);
 }
 
 /**
  * @brief Find a device given a unit number
  *
  * @param dc		the devclass to search
  * @param unit		the unit number to search for
  *
  * @returns		the device with the given unit number or @c
  *			NULL if there is no such device
  */
 device_t
 devclass_get_device(devclass_t dc, int unit)
 {
 	if (dc == NULL || unit < 0 || unit >= dc->maxunit)
 		return (NULL);
 	return (dc->devices[unit]);
 }
 
 /**
  * @brief Find the softc field of a device given a unit number
  *
  * @param dc		the devclass to search
  * @param unit		the unit number to search for
  *
  * @returns		the softc field of the device with the given
  *			unit number or @c NULL if there is no such
  *			device
  */
 void *
 devclass_get_softc(devclass_t dc, int unit)
 {
 	device_t dev;
 
 	dev = devclass_get_device(dc, unit);
 	if (!dev)
 		return (NULL);
 
 	return (device_get_softc(dev));
 }
 
 /**
  * @brief Get a list of devices in the devclass
  *
  * An array containing a list of all the devices in the given devclass
  * is allocated and returned in @p *devlistp. The number of devices
  * in the array is returned in @p *devcountp. The caller should free
  * the array using @c free(p, M_TEMP), even if @p *devcountp is 0.
  *
  * @param dc		the devclass to examine
  * @param devlistp	points at location for array pointer return
  *			value
  * @param devcountp	points at location for array size return value
  *
  * @retval 0		success
  * @retval ENOMEM	the array allocation failed
  */
 int
 devclass_get_devices(devclass_t dc, device_t **devlistp, int *devcountp)
 {
 	int count, i;
 	device_t *list;
 
 	count = devclass_get_count(dc);
 	list = malloc(count * sizeof(device_t), M_TEMP, M_NOWAIT|M_ZERO);
 	if (!list)
 		return (ENOMEM);
 
 	count = 0;
 	for (i = 0; i < dc->maxunit; i++) {
 		if (dc->devices[i]) {
 			list[count] = dc->devices[i];
 			count++;
 		}
 	}
 
 	*devlistp = list;
 	*devcountp = count;
 
 	return (0);
 }
 
 /**
  * @brief Get a list of drivers in the devclass
  *
  * An array containing a list of pointers to all the drivers in the
  * given devclass is allocated and returned in @p *listp.  The number
  * of drivers in the array is returned in @p *countp. The caller should
  * free the array using @c free(p, M_TEMP).
  *
  * @param dc		the devclass to examine
  * @param listp		gives location for array pointer return value
  * @param countp	gives location for number of array elements
  *			return value
  *
  * @retval 0		success
  * @retval ENOMEM	the array allocation failed
  */
 int
 devclass_get_drivers(devclass_t dc, driver_t ***listp, int *countp)
 {
 	driverlink_t dl;
 	driver_t **list;
 	int count;
 
 	count = 0;
 	TAILQ_FOREACH(dl, &dc->drivers, link)
 		count++;
 	list = malloc(count * sizeof(driver_t *), M_TEMP, M_NOWAIT);
 	if (list == NULL)
 		return (ENOMEM);
 
 	count = 0;
 	TAILQ_FOREACH(dl, &dc->drivers, link) {
 		list[count] = dl->driver;
 		count++;
 	}
 	*listp = list;
 	*countp = count;
 
 	return (0);
 }
 
 /**
  * @brief Get the number of devices in a devclass
  *
  * @param dc		the devclass to examine
  */
 int
 devclass_get_count(devclass_t dc)
 {
 	int count, i;
 
 	count = 0;
 	for (i = 0; i < dc->maxunit; i++)
 		if (dc->devices[i])
 			count++;
 	return (count);
 }
 
 /**
  * @brief Get the maximum unit number used in a devclass
  *
  * Note that this is one greater than the highest currently-allocated
  * unit.  If a null devclass_t is passed in, -1 is returned to indicate
  * that not even the devclass has been allocated yet.
  *
  * @param dc		the devclass to examine
  */
 int
 devclass_get_maxunit(devclass_t dc)
 {
 	if (dc == NULL)
 		return (-1);
 	return (dc->maxunit);
 }
 
 /**
  * @brief Find a free unit number in a devclass
  *
  * This function searches for the first unused unit number greater
  * that or equal to @p unit.
  *
  * @param dc		the devclass to examine
  * @param unit		the first unit number to check
  */
 int
 devclass_find_free_unit(devclass_t dc, int unit)
 {
 	if (dc == NULL)
 		return (unit);
 	while (unit < dc->maxunit && dc->devices[unit] != NULL)
 		unit++;
 	return (unit);
 }
 
 /**
  * @brief Set the parent of a devclass
  *
  * The parent class is normally initialised automatically by
  * DRIVER_MODULE().
  *
  * @param dc		the devclass to edit
  * @param pdc		the new parent devclass
  */
 void
 devclass_set_parent(devclass_t dc, devclass_t pdc)
 {
 	dc->parent = pdc;
 }
 
 /**
  * @brief Get the parent of a devclass
  *
  * @param dc		the devclass to examine
  */
 devclass_t
 devclass_get_parent(devclass_t dc)
 {
 	return (dc->parent);
 }
 
 struct sysctl_ctx_list *
 devclass_get_sysctl_ctx(devclass_t dc)
 {
 	return (&dc->sysctl_ctx);
 }
 
 struct sysctl_oid *
 devclass_get_sysctl_tree(devclass_t dc)
 {
 	return (dc->sysctl_tree);
 }
 
 /**
  * @internal
  * @brief Allocate a unit number
  *
  * On entry, @p *unitp is the desired unit number (or @c -1 if any
  * will do). The allocated unit number is returned in @p *unitp.
 
  * @param dc		the devclass to allocate from
  * @param unitp		points at the location for the allocated unit
  *			number
  *
  * @retval 0		success
  * @retval EEXIST	the requested unit number is already allocated
  * @retval ENOMEM	memory allocation failure
  */
 static int
 devclass_alloc_unit(devclass_t dc, device_t dev, int *unitp)
 {
 	const char *s;
 	int unit = *unitp;
 
 	PDEBUG(("unit %d in devclass %s", unit, DEVCLANAME(dc)));
 
 	/* Ask the parent bus if it wants to wire this device. */
 	if (unit == -1)
 		BUS_HINT_DEVICE_UNIT(device_get_parent(dev), dev, dc->name,
 		    &unit);
 
 	/* If we were given a wired unit number, check for existing device */
 	/* XXX imp XXX */
 	if (unit != -1) {
 		if (unit >= 0 && unit < dc->maxunit &&
 		    dc->devices[unit] != NULL) {
 			if (bootverbose)
 				printf("%s: %s%d already exists; skipping it\n",
 				    dc->name, dc->name, *unitp);
 			return (EEXIST);
 		}
 	} else {
 		/* Unwired device, find the next available slot for it */
 		unit = 0;
 		for (unit = 0;; unit++) {
 			/* If this device slot is already in use, skip it. */
 			if (unit < dc->maxunit && dc->devices[unit] != NULL)
 				continue;
 
 			/* If there is an "at" hint for a unit then skip it. */
 			if (resource_string_value(dc->name, unit, "at", &s) ==
 			    0)
 				continue;
 
 			break;
 		}
 	}
 
 	/*
 	 * We've selected a unit beyond the length of the table, so let's
 	 * extend the table to make room for all units up to and including
 	 * this one.
 	 */
 	if (unit >= dc->maxunit) {
 		device_t *newlist, *oldlist;
 		int newsize;
 
 		oldlist = dc->devices;
 		newsize = roundup((unit + 1),
 		    MAX(1, MINALLOCSIZE / sizeof(device_t)));
 		newlist = malloc(sizeof(device_t) * newsize, M_BUS, M_NOWAIT);
 		if (!newlist)
 			return (ENOMEM);
 		if (oldlist != NULL)
 			bcopy(oldlist, newlist, sizeof(device_t) * dc->maxunit);
 		bzero(newlist + dc->maxunit,
 		    sizeof(device_t) * (newsize - dc->maxunit));
 		dc->devices = newlist;
 		dc->maxunit = newsize;
 		if (oldlist != NULL)
 			free(oldlist, M_BUS);
 	}
 	PDEBUG(("now: unit %d in devclass %s", unit, DEVCLANAME(dc)));
 
 	*unitp = unit;
 	return (0);
 }
 
 /**
  * @internal
  * @brief Add a device to a devclass
  *
  * A unit number is allocated for the device (using the device's
  * preferred unit number if any) and the device is registered in the
  * devclass. This allows the device to be looked up by its unit
  * number, e.g. by decoding a dev_t minor number.
  *
  * @param dc		the devclass to add to
  * @param dev		the device to add
  *
  * @retval 0		success
  * @retval EEXIST	the requested unit number is already allocated
  * @retval ENOMEM	memory allocation failure
  */
 static int
 devclass_add_device(devclass_t dc, device_t dev)
 {
 	int buflen, error;
 
 	PDEBUG(("%s in devclass %s", DEVICENAME(dev), DEVCLANAME(dc)));
 
 	buflen = snprintf(NULL, 0, "%s%d$", dc->name, INT_MAX);
 	if (buflen < 0)
 		return (ENOMEM);
 	dev->nameunit = malloc(buflen, M_BUS, M_NOWAIT|M_ZERO);
 	if (!dev->nameunit)
 		return (ENOMEM);
 
 	if ((error = devclass_alloc_unit(dc, dev, &dev->unit)) != 0) {
 		free(dev->nameunit, M_BUS);
 		dev->nameunit = NULL;
 		return (error);
 	}
 	dc->devices[dev->unit] = dev;
 	dev->devclass = dc;
 	snprintf(dev->nameunit, buflen, "%s%d", dc->name, dev->unit);
 
 	return (0);
 }
 
 /**
  * @internal
  * @brief Delete a device from a devclass
  *
  * The device is removed from the devclass's device list and its unit
  * number is freed.
 
  * @param dc		the devclass to delete from
  * @param dev		the device to delete
  *
  * @retval 0		success
  */
 static int
 devclass_delete_device(devclass_t dc, device_t dev)
 {
 	if (!dc || !dev)
 		return (0);
 
 	PDEBUG(("%s in devclass %s", DEVICENAME(dev), DEVCLANAME(dc)));
 
 	if (dev->devclass != dc || dc->devices[dev->unit] != dev)
 		panic("devclass_delete_device: inconsistent device class");
 	dc->devices[dev->unit] = NULL;
 	if (dev->flags & DF_WILDCARD)
 		dev->unit = -1;
 	dev->devclass = NULL;
 	free(dev->nameunit, M_BUS);
 	dev->nameunit = NULL;
 
 	return (0);
 }
 
 /**
  * @internal
  * @brief Make a new device and add it as a child of @p parent
  *
  * @param parent	the parent of the new device
  * @param name		the devclass name of the new device or @c NULL
  *			to leave the devclass unspecified
  * @parem unit		the unit number of the new device of @c -1 to
  *			leave the unit number unspecified
  *
  * @returns the new device
  */
 static device_t
 make_device(device_t parent, const char *name, int unit)
 {
 	device_t dev;
 	devclass_t dc;
 
 	PDEBUG(("%s at %s as unit %d", name, DEVICENAME(parent), unit));
 
 	if (name) {
 		dc = devclass_find_internal(name, NULL, TRUE);
 		if (!dc) {
 			printf("make_device: can't find device class %s\n",
 			    name);
 			return (NULL);
 		}
 	} else {
 		dc = NULL;
 	}
 
 	dev = malloc(sizeof(*dev), M_BUS, M_NOWAIT|M_ZERO);
 	if (!dev)
 		return (NULL);
 
 	dev->parent = parent;
 	TAILQ_INIT(&dev->children);
 	kobj_init((kobj_t) dev, &null_class);
 	dev->driver = NULL;
 	dev->devclass = NULL;
 	dev->unit = unit;
 	dev->nameunit = NULL;
 	dev->desc = NULL;
 	dev->busy = 0;
 	dev->devflags = 0;
 	dev->flags = DF_ENABLED;
 	dev->order = 0;
 	if (unit == -1)
 		dev->flags |= DF_WILDCARD;
 	if (name) {
 		dev->flags |= DF_FIXEDCLASS;
 		if (devclass_add_device(dc, dev)) {
 			kobj_delete((kobj_t) dev, M_BUS);
 			return (NULL);
 		}
 	}
 	if (parent != NULL && device_has_quiet_children(parent))
 		dev->flags |= DF_QUIET | DF_QUIET_CHILDREN;
 	dev->ivars = NULL;
 	dev->softc = NULL;
 	LIST_INIT(&dev->props);
 
 	dev->state = DS_NOTPRESENT;
 
 	TAILQ_INSERT_TAIL(&bus_data_devices, dev, devlink);
 	bus_data_generation_update();
 
 	return (dev);
 }
 
 /**
  * @internal
  * @brief Print a description of a device.
  */
 static int
 device_print_child(device_t dev, device_t child)
 {
 	int retval = 0;
 
 	if (device_is_alive(child))
 		retval += BUS_PRINT_CHILD(dev, child);
 	else
 		retval += device_printf(child, " not found\n");
 
 	return (retval);
 }
 
 /**
  * @brief Create a new device
  *
  * This creates a new device and adds it as a child of an existing
  * parent device. The new device will be added after the last existing
  * child with order zero.
  *
  * @param dev		the device which will be the parent of the
  *			new child device
  * @param name		devclass name for new device or @c NULL if not
  *			specified
  * @param unit		unit number for new device or @c -1 if not
  *			specified
  *
  * @returns		the new device
  */
 device_t
 device_add_child(device_t dev, const char *name, int unit)
 {
 	return (device_add_child_ordered(dev, 0, name, unit));
 }
 
 /**
  * @brief Create a new device
  *
  * This creates a new device and adds it as a child of an existing
  * parent device. The new device will be added after the last existing
  * child with the same order.
  *
  * @param dev		the device which will be the parent of the
  *			new child device
  * @param order		a value which is used to partially sort the
  *			children of @p dev - devices created using
  *			lower values of @p order appear first in @p
  *			dev's list of children
  * @param name		devclass name for new device or @c NULL if not
  *			specified
  * @param unit		unit number for new device or @c -1 if not
  *			specified
  *
  * @returns		the new device
  */
 device_t
 device_add_child_ordered(device_t dev, u_int order, const char *name, int unit)
 {
 	device_t child;
 	device_t place;
 
 	PDEBUG(("%s at %s with order %u as unit %d",
 	    name, DEVICENAME(dev), order, unit));
 	KASSERT(name != NULL || unit == -1,
 	    ("child device with wildcard name and specific unit number"));
 
 	child = make_device(dev, name, unit);
 	if (child == NULL)
 		return (child);
 	child->order = order;
 
 	TAILQ_FOREACH(place, &dev->children, link) {
 		if (place->order > order)
 			break;
 	}
 
 	if (place) {
 		/*
 		 * The device 'place' is the first device whose order is
 		 * greater than the new child.
 		 */
 		TAILQ_INSERT_BEFORE(place, child, link);
 	} else {
 		/*
 		 * The new child's order is greater or equal to the order of
 		 * any existing device. Add the child to the tail of the list.
 		 */
 		TAILQ_INSERT_TAIL(&dev->children, child, link);
 	}
 
 	bus_data_generation_update();
 	return (child);
 }
 
 /**
  * @brief Delete a device
  *
  * This function deletes a device along with all of its children. If
  * the device currently has a driver attached to it, the device is
  * detached first using device_detach().
  *
  * @param dev		the parent device
  * @param child		the device to delete
  *
  * @retval 0		success
  * @retval non-zero	a unit error code describing the error
  */
 int
 device_delete_child(device_t dev, device_t child)
 {
 	int error;
 	device_t grandchild;
 
 	PDEBUG(("%s from %s", DEVICENAME(child), DEVICENAME(dev)));
 
 	/*
 	 * Detach child.  Ideally this cleans up any grandchild
 	 * devices.
 	 */
 	if ((error = device_detach(child)) != 0)
 		return (error);
 
 	/* Delete any grandchildren left after detach. */
 	while ((grandchild = TAILQ_FIRST(&child->children)) != NULL) {
 		error = device_delete_child(child, grandchild);
 		if (error)
 			return (error);
 	}
 
 	device_destroy_props(dev);
 	if (child->devclass)
 		devclass_delete_device(child->devclass, child);
 	if (child->parent)
 		BUS_CHILD_DELETED(dev, child);
 	TAILQ_REMOVE(&dev->children, child, link);
 	TAILQ_REMOVE(&bus_data_devices, child, devlink);
 	kobj_delete((kobj_t) child, M_BUS);
 
 	bus_data_generation_update();
 	return (0);
 }
 
 /**
  * @brief Delete all children devices of the given device, if any.
  *
  * This function deletes all children devices of the given device, if
  * any, using the device_delete_child() function for each device it
  * finds. If a child device cannot be deleted, this function will
  * return an error code.
  *
  * @param dev		the parent device
  *
  * @retval 0		success
  * @retval non-zero	a device would not detach
  */
 int
 device_delete_children(device_t dev)
 {
 	device_t child;
 	int error;
 
 	PDEBUG(("Deleting all children of %s", DEVICENAME(dev)));
 
 	error = 0;
 
 	while ((child = TAILQ_FIRST(&dev->children)) != NULL) {
 		error = device_delete_child(dev, child);
 		if (error) {
 			PDEBUG(("Failed deleting %s", DEVICENAME(child)));
 			break;
 		}
 	}
 	return (error);
 }
 
 /**
  * @brief Find a device given a unit number
  *
  * This is similar to devclass_get_devices() but only searches for
  * devices which have @p dev as a parent.
  *
  * @param dev		the parent device to search
  * @param unit		the unit number to search for.  If the unit is -1,
  *			return the first child of @p dev which has name
  *			@p classname (that is, the one with the lowest unit.)
  *
  * @returns		the device with the given unit number or @c
  *			NULL if there is no such device
  */
 device_t
 device_find_child(device_t dev, const char *classname, int unit)
 {
 	devclass_t dc;
 	device_t child;
 
 	dc = devclass_find(classname);
 	if (!dc)
 		return (NULL);
 
 	if (unit != -1) {
 		child = devclass_get_device(dc, unit);
 		if (child && child->parent == dev)
 			return (child);
 	} else {
 		for (unit = 0; unit < devclass_get_maxunit(dc); unit++) {
 			child = devclass_get_device(dc, unit);
 			if (child && child->parent == dev)
 				return (child);
 		}
 	}
 	return (NULL);
 }
 
 /**
  * @internal
  */
 static driverlink_t
 first_matching_driver(devclass_t dc, device_t dev)
 {
 	if (dev->devclass)
 		return (devclass_find_driver_internal(dc, dev->devclass->name));
 	return (TAILQ_FIRST(&dc->drivers));
 }
 
 /**
  * @internal
  */
 static driverlink_t
 next_matching_driver(devclass_t dc, device_t dev, driverlink_t last)
 {
 	if (dev->devclass) {
 		driverlink_t dl;
 		for (dl = TAILQ_NEXT(last, link); dl; dl = TAILQ_NEXT(dl, link))
 			if (!strcmp(dev->devclass->name, dl->driver->name))
 				return (dl);
 		return (NULL);
 	}
 	return (TAILQ_NEXT(last, link));
 }
 
 /**
  * @internal
  */
 int
 device_probe_child(device_t dev, device_t child)
 {
 	devclass_t dc;
 	driverlink_t best = NULL;
 	driverlink_t dl;
 	int result, pri = 0;
 	/* We should preserve the devclass (or lack of) set by the bus. */
 	int hasclass = (child->devclass != NULL);
 
 	bus_topo_assert();
 
 	dc = dev->devclass;
 	if (!dc)
 		panic("device_probe_child: parent device has no devclass");
 
 	/*
 	 * If the state is already probed, then return.
 	 */
 	if (child->state == DS_ALIVE)
 		return (0);
 
 	for (; dc; dc = dc->parent) {
 		for (dl = first_matching_driver(dc, child);
 		     dl;
 		     dl = next_matching_driver(dc, child, dl)) {
 			/* If this driver's pass is too high, then ignore it. */
 			if (dl->pass > bus_current_pass)
 				continue;
 
 			PDEBUG(("Trying %s", DRIVERNAME(dl->driver)));
 			result = device_set_driver(child, dl->driver);
 			if (result == ENOMEM)
 				return (result);
 			else if (result != 0)
 				continue;
 			if (!hasclass) {
 				if (device_set_devclass(child,
 				    dl->driver->name) != 0) {
 					char const * devname =
 					    device_get_name(child);
 					if (devname == NULL)
 						devname = "(unknown)";
 					printf("driver bug: Unable to set "
 					    "devclass (class: %s "
 					    "devname: %s)\n",
 					    dl->driver->name,
 					    devname);
 					(void)device_set_driver(child, NULL);
 					continue;
 				}
 			}
 
 			/* Fetch any flags for the device before probing. */
 			resource_int_value(dl->driver->name, child->unit,
 			    "flags", &child->devflags);
 
 			result = DEVICE_PROBE(child);
 
 			/*
 			 * If the driver returns SUCCESS, there can be
 			 * no higher match for this device.
 			 */
 			if (result == 0) {
 				best = dl;
 				pri = 0;
 				break;
 			}
 
 			/* Reset flags and devclass before the next probe. */
 			child->devflags = 0;
 			if (!hasclass)
 				(void)device_set_devclass(child, NULL);
 
 			/*
 			 * Reset DF_QUIET in case this driver doesn't
 			 * end up as the best driver.
 			 */
 			device_verbose(child);
 
 			/*
 			 * Probes that return BUS_PROBE_NOWILDCARD or lower
 			 * only match on devices whose driver was explicitly
 			 * specified.
 			 */
 			if (result <= BUS_PROBE_NOWILDCARD &&
 			    !(child->flags & DF_FIXEDCLASS)) {
 				result = ENXIO;
 			}
 
 			/*
 			 * The driver returned an error so it
 			 * certainly doesn't match.
 			 */
 			if (result > 0) {
 				(void)device_set_driver(child, NULL);
 				continue;
 			}
 
 			/*
 			 * A priority lower than SUCCESS, remember the
 			 * best matching driver. Initialise the value
 			 * of pri for the first match.
 			 */
 			if (best == NULL || result > pri) {
 				best = dl;
 				pri = result;
 				continue;
 			}
 		}
 		/*
 		 * If we have an unambiguous match in this devclass,
 		 * don't look in the parent.
 		 */
 		if (best && pri == 0)
 			break;
 	}
 
 	if (best == NULL)
 		return (ENXIO);
 
 	/*
 	 * If we found a driver, change state and initialise the devclass.
 	 */
 	if (pri < 0) {
 		/* Set the winning driver, devclass, and flags. */
 		result = device_set_driver(child, best->driver);
 		if (result != 0)
 			return (result);
 		if (!child->devclass) {
 			result = device_set_devclass(child, best->driver->name);
 			if (result != 0) {
 				(void)device_set_driver(child, NULL);
 				return (result);
 			}
 		}
 		resource_int_value(best->driver->name, child->unit,
 		    "flags", &child->devflags);
 
 		/*
 		 * A bit bogus. Call the probe method again to make sure
 		 * that we have the right description.
 		 */
 		result = DEVICE_PROBE(child);
 		if (result > 0) {
 			if (!hasclass)
 				(void)device_set_devclass(child, NULL);
 			(void)device_set_driver(child, NULL);
 			return (result);
 		}
 	}
 
 	child->state = DS_ALIVE;
 	bus_data_generation_update();
 	return (0);
 }
 
 /**
  * @brief Return the parent of a device
  */
 device_t
 device_get_parent(device_t dev)
 {
 	return (dev->parent);
 }
 
 /**
  * @brief Get a list of children of a device
  *
  * An array containing a list of all the children of the given device
  * is allocated and returned in @p *devlistp. The number of devices
  * in the array is returned in @p *devcountp. The caller should free
  * the array using @c free(p, M_TEMP).
  *
  * @param dev		the device to examine
  * @param devlistp	points at location for array pointer return
  *			value
  * @param devcountp	points at location for array size return value
  *
  * @retval 0		success
  * @retval ENOMEM	the array allocation failed
  */
 int
 device_get_children(device_t dev, device_t **devlistp, int *devcountp)
 {
 	int count;
 	device_t child;
 	device_t *list;
 
 	count = 0;
 	TAILQ_FOREACH(child, &dev->children, link) {
 		count++;
 	}
 	if (count == 0) {
 		*devlistp = NULL;
 		*devcountp = 0;
 		return (0);
 	}
 
 	list = malloc(count * sizeof(device_t), M_TEMP, M_NOWAIT|M_ZERO);
 	if (!list)
 		return (ENOMEM);
 
 	count = 0;
 	TAILQ_FOREACH(child, &dev->children, link) {
 		list[count] = child;
 		count++;
 	}
 
 	*devlistp = list;
 	*devcountp = count;
 
 	return (0);
 }
 
 /**
  * @brief Return the current driver for the device or @c NULL if there
  * is no driver currently attached
  */
 driver_t *
 device_get_driver(device_t dev)
 {
 	return (dev->driver);
 }
 
 /**
  * @brief Return the current devclass for the device or @c NULL if
  * there is none.
  */
 devclass_t
 device_get_devclass(device_t dev)
 {
 	return (dev->devclass);
 }
 
 /**
  * @brief Return the name of the device's devclass or @c NULL if there
  * is none.
  */
 const char *
 device_get_name(device_t dev)
 {
 	if (dev != NULL && dev->devclass)
 		return (devclass_get_name(dev->devclass));
 	return (NULL);
 }
 
 /**
  * @brief Return a string containing the device's devclass name
  * followed by an ascii representation of the device's unit number
  * (e.g. @c "foo2").
  */
 const char *
 device_get_nameunit(device_t dev)
 {
 	return (dev->nameunit);
 }
 
 /**
  * @brief Return the device's unit number.
  */
 int
 device_get_unit(device_t dev)
 {
 	return (dev->unit);
 }
 
 /**
  * @brief Return the device's description string
  */
 const char *
 device_get_desc(device_t dev)
 {
 	return (dev->desc);
 }
 
 /**
  * @brief Return the device's flags
  */
 uint32_t
 device_get_flags(device_t dev)
 {
 	return (dev->devflags);
 }
 
 struct sysctl_ctx_list *
 device_get_sysctl_ctx(device_t dev)
 {
 	return (&dev->sysctl_ctx);
 }
 
 struct sysctl_oid *
 device_get_sysctl_tree(device_t dev)
 {
 	return (dev->sysctl_tree);
 }
 
 /**
  * @brief Print the name of the device followed by a colon and a space
  *
  * @returns the number of characters printed
  */
 int
 device_print_prettyname(device_t dev)
 {
 	const char *name = device_get_name(dev);
 
 	if (name == NULL)
 		return (printf("unknown: "));
 	return (printf("%s%d: ", name, device_get_unit(dev)));
 }
 
 /**
  * @brief Print the name of the device followed by a colon, a space
  * and the result of calling vprintf() with the value of @p fmt and
  * the following arguments.
  *
  * @returns the number of characters printed
  */
 int
 device_printf(device_t dev, const char * fmt, ...)
 {
 	char buf[128];
 	struct sbuf sb;
 	const char *name;
 	va_list ap;
 	size_t retval;
 
 	retval = 0;
 
 	sbuf_new(&sb, buf, sizeof(buf), SBUF_FIXEDLEN);
 	sbuf_set_drain(&sb, sbuf_printf_drain, &retval);
 
 	name = device_get_name(dev);
 
 	if (name == NULL)
 		sbuf_cat(&sb, "unknown: ");
 	else
 		sbuf_printf(&sb, "%s%d: ", name, device_get_unit(dev));
 
 	va_start(ap, fmt);
 	sbuf_vprintf(&sb, fmt, ap);
 	va_end(ap);
 
 	sbuf_finish(&sb);
 	sbuf_delete(&sb);
 
 	return (retval);
 }
 
 /**
  * @brief Print the name of the device followed by a colon, a space
  * and the result of calling log() with the value of @p fmt and
  * the following arguments.
  *
  * @returns the number of characters printed
  */
 int
 device_log(device_t dev, int pri, const char * fmt, ...)
 {
 	char buf[128];
 	struct sbuf sb;
 	const char *name;
 	va_list ap;
 	size_t retval;
 
 	retval = 0;
 
 	sbuf_new(&sb, buf, sizeof(buf), SBUF_FIXEDLEN);
 
 	name = device_get_name(dev);
 
 	if (name == NULL)
 		sbuf_cat(&sb, "unknown: ");
 	else
 		sbuf_printf(&sb, "%s%d: ", name, device_get_unit(dev));
 
 	va_start(ap, fmt);
 	sbuf_vprintf(&sb, fmt, ap);
 	va_end(ap);
 
 	sbuf_finish(&sb);
 
 	log(pri, "%.*s", (int) sbuf_len(&sb), sbuf_data(&sb));
 	retval = sbuf_len(&sb);
 
 	sbuf_delete(&sb);
 
 	return (retval);
 }
 
 /**
  * @internal
  */
 static void
 device_set_desc_internal(device_t dev, const char *desc, bool allocated)
 {
 	if (dev->desc && (dev->flags & DF_DESCMALLOCED)) {
 		free(dev->desc, M_BUS);
 		dev->flags &= ~DF_DESCMALLOCED;
 		dev->desc = NULL;
 	}
 
 	if (allocated && desc)
 		dev->flags |= DF_DESCMALLOCED;
 	dev->desc = __DECONST(char *, desc);
 
 	bus_data_generation_update();
 }
 
 /**
  * @brief Set the device's description
  *
  * The value of @c desc should be a string constant that will not
  * change (at least until the description is changed in a subsequent
  * call to device_set_desc() or device_set_desc_copy()).
  */
 void
 device_set_desc(device_t dev, const char *desc)
 {
 	device_set_desc_internal(dev, desc, false);
 }
 
 /**
  * @brief Set the device's description
  *
  * A printf-like version of device_set_desc().
  */
 void
 device_set_descf(device_t dev, const char *fmt, ...)
 {
 	va_list ap;
 	char *buf = NULL;
 
 	va_start(ap, fmt);
 	vasprintf(&buf, M_BUS, fmt, ap);
 	va_end(ap);
 	device_set_desc_internal(dev, buf, true);
 }
 
 /**
  * @brief Set the device's description
  *
  * The string pointed to by @c desc is copied. Use this function if
  * the device description is generated, (e.g. with sprintf()).
  */
 void
 device_set_desc_copy(device_t dev, const char *desc)
 {
 	char *buf;
 
 	buf = strdup_flags(desc, M_BUS, M_NOWAIT);
 	device_set_desc_internal(dev, buf, true);
 }
 
 /**
  * @brief Set the device's flags
  */
 void
 device_set_flags(device_t dev, uint32_t flags)
 {
 	dev->devflags = flags;
 }
 
 /**
  * @brief Return the device's softc field
  *
  * The softc is allocated and zeroed when a driver is attached, based
  * on the size field of the driver.
  */
 void *
 device_get_softc(device_t dev)
 {
 	return (dev->softc);
 }
 
 /**
  * @brief Set the device's softc field
  *
  * Most drivers do not need to use this since the softc is allocated
  * automatically when the driver is attached.
  */
 void
 device_set_softc(device_t dev, void *softc)
 {
 	if (dev->softc && !(dev->flags & DF_EXTERNALSOFTC))
 		free(dev->softc, M_BUS_SC);
 	dev->softc = softc;
 	if (dev->softc)
 		dev->flags |= DF_EXTERNALSOFTC;
 	else
 		dev->flags &= ~DF_EXTERNALSOFTC;
 }
 
 /**
  * @brief Free claimed softc
  *
  * Most drivers do not need to use this since the softc is freed
  * automatically when the driver is detached.
  */
 void
 device_free_softc(void *softc)
 {
 	free(softc, M_BUS_SC);
 }
 
 /**
  * @brief Claim softc
  *
  * This function can be used to let the driver free the automatically
  * allocated softc using "device_free_softc()". This function is
  * useful when the driver is refcounting the softc and the softc
  * cannot be freed when the "device_detach" method is called.
  */
 void
 device_claim_softc(device_t dev)
 {
 	if (dev->softc)
 		dev->flags |= DF_EXTERNALSOFTC;
 	else
 		dev->flags &= ~DF_EXTERNALSOFTC;
 }
 
 /**
  * @brief Get the device's ivars field
  *
  * The ivars field is used by the parent device to store per-device
  * state (e.g. the physical location of the device or a list of
  * resources).
  */
 void *
 device_get_ivars(device_t dev)
 {
 	KASSERT(dev != NULL, ("device_get_ivars(NULL, ...)"));
 	return (dev->ivars);
 }
 
 /**
  * @brief Set the device's ivars field
  */
 void
 device_set_ivars(device_t dev, void * ivars)
 {
 	KASSERT(dev != NULL, ("device_set_ivars(NULL, ...)"));
 	dev->ivars = ivars;
 }
 
 /**
  * @brief Return the device's state
  */
 device_state_t
 device_get_state(device_t dev)
 {
 	return (dev->state);
 }
 
 /**
  * @brief Set the DF_ENABLED flag for the device
  */
 void
 device_enable(device_t dev)
 {
 	dev->flags |= DF_ENABLED;
 }
 
 /**
  * @brief Clear the DF_ENABLED flag for the device
  */
 void
 device_disable(device_t dev)
 {
 	dev->flags &= ~DF_ENABLED;
 }
 
 /**
  * @brief Increment the busy counter for the device
  */
 void
 device_busy(device_t dev)
 {
 
 	/*
 	 * Mark the device as busy, recursively up the tree if this busy count
 	 * goes 0->1.
 	 */
 	if (refcount_acquire(&dev->busy) == 0 && dev->parent != NULL)
 		device_busy(dev->parent);
 }
 
 /**
  * @brief Decrement the busy counter for the device
  */
 void
 device_unbusy(device_t dev)
 {
 
 	/*
 	 * Mark the device as unbsy, recursively if this is the last busy count.
 	 */
 	if (refcount_release(&dev->busy) && dev->parent != NULL)
 		device_unbusy(dev->parent);
 }
 
 /**
  * @brief Set the DF_QUIET flag for the device
  */
 void
 device_quiet(device_t dev)
 {
 	dev->flags |= DF_QUIET;
 }
 
 /**
  * @brief Set the DF_QUIET_CHILDREN flag for the device
  */
 void
 device_quiet_children(device_t dev)
 {
 	dev->flags |= DF_QUIET_CHILDREN;
 }
 
 /**
  * @brief Clear the DF_QUIET flag for the device
  */
 void
 device_verbose(device_t dev)
 {
 	dev->flags &= ~DF_QUIET;
 }
 
 ssize_t
 device_get_property(device_t dev, const char *prop, void *val, size_t sz,
     device_property_type_t type)
 {
 	device_t bus = device_get_parent(dev);
 
 	switch (type) {
 	case DEVICE_PROP_ANY:
 	case DEVICE_PROP_BUFFER:
 	case DEVICE_PROP_HANDLE:	/* Size checks done in implementation. */
 		break;
 	case DEVICE_PROP_UINT32:
 		if (sz % 4 != 0)
 			return (-1);
 		break;
 	case DEVICE_PROP_UINT64:
 		if (sz % 8 != 0)
 			return (-1);
 		break;
 	default:
 		return (-1);
 	}
 
 	return (BUS_GET_PROPERTY(bus, dev, prop, val, sz, type));
 }
 
 bool
 device_has_property(device_t dev, const char *prop)
 {
 	return (device_get_property(dev, prop, NULL, 0, DEVICE_PROP_ANY) >= 0);
 }
 
 /**
  * @brief Return non-zero if the DF_QUIET_CHIDLREN flag is set on the device
  */
 int
 device_has_quiet_children(device_t dev)
 {
 	return ((dev->flags & DF_QUIET_CHILDREN) != 0);
 }
 
 /**
  * @brief Return non-zero if the DF_QUIET flag is set on the device
  */
 int
 device_is_quiet(device_t dev)
 {
 	return ((dev->flags & DF_QUIET) != 0);
 }
 
 /**
  * @brief Return non-zero if the DF_ENABLED flag is set on the device
  */
 int
 device_is_enabled(device_t dev)
 {
 	return ((dev->flags & DF_ENABLED) != 0);
 }
 
 /**
  * @brief Return non-zero if the device was successfully probed
  */
 int
 device_is_alive(device_t dev)
 {
 	return (dev->state >= DS_ALIVE);
 }
 
 /**
  * @brief Return non-zero if the device currently has a driver
  * attached to it
  */
 int
 device_is_attached(device_t dev)
 {
 	return (dev->state >= DS_ATTACHED);
 }
 
 /**
  * @brief Return non-zero if the device is currently suspended.
  */
 int
 device_is_suspended(device_t dev)
 {
 	return ((dev->flags & DF_SUSPENDED) != 0);
 }
 
 /**
  * @brief Set the devclass of a device
  * @see devclass_add_device().
  */
 int
 device_set_devclass(device_t dev, const char *classname)
 {
 	devclass_t dc;
 	int error;
 
 	if (!classname) {
 		if (dev->devclass)
 			devclass_delete_device(dev->devclass, dev);
 		return (0);
 	}
 
 	if (dev->devclass) {
 		printf("device_set_devclass: device class already set\n");
 		return (EINVAL);
 	}
 
 	dc = devclass_find_internal(classname, NULL, TRUE);
 	if (!dc)
 		return (ENOMEM);
 
 	error = devclass_add_device(dc, dev);
 
 	bus_data_generation_update();
 	return (error);
 }
 
 /**
  * @brief Set the devclass of a device and mark the devclass fixed.
  * @see device_set_devclass()
  */
 int
 device_set_devclass_fixed(device_t dev, const char *classname)
 {
 	int error;
 
 	if (classname == NULL)
 		return (EINVAL);
 
 	error = device_set_devclass(dev, classname);
 	if (error)
 		return (error);
 	dev->flags |= DF_FIXEDCLASS;
 	return (0);
 }
 
 /**
  * @brief Query the device to determine if it's of a fixed devclass
  * @see device_set_devclass_fixed()
  */
 bool
 device_is_devclass_fixed(device_t dev)
 {
 	return ((dev->flags & DF_FIXEDCLASS) != 0);
 }
 
 /**
  * @brief Set the driver of a device
  *
  * @retval 0		success
  * @retval EBUSY	the device already has a driver attached
  * @retval ENOMEM	a memory allocation failure occurred
  */
 int
 device_set_driver(device_t dev, driver_t *driver)
 {
 	int domain;
 	struct domainset *policy;
 
 	if (dev->state >= DS_ATTACHED)
 		return (EBUSY);
 
 	if (dev->driver == driver)
 		return (0);
 
 	if (dev->softc && !(dev->flags & DF_EXTERNALSOFTC)) {
 		free(dev->softc, M_BUS_SC);
 		dev->softc = NULL;
 	}
 	device_set_desc(dev, NULL);
 	kobj_delete((kobj_t) dev, NULL);
 	dev->driver = driver;
 	if (driver) {
 		kobj_init((kobj_t) dev, (kobj_class_t) driver);
 		if (!(dev->flags & DF_EXTERNALSOFTC) && driver->size > 0) {
 			if (bus_get_domain(dev, &domain) == 0)
 				policy = DOMAINSET_PREF(domain);
 			else
 				policy = DOMAINSET_RR();
 			dev->softc = malloc_domainset(driver->size, M_BUS_SC,
 			    policy, M_NOWAIT | M_ZERO);
 			if (!dev->softc) {
 				kobj_delete((kobj_t) dev, NULL);
 				kobj_init((kobj_t) dev, &null_class);
 				dev->driver = NULL;
 				return (ENOMEM);
 			}
 		}
 	} else {
 		kobj_init((kobj_t) dev, &null_class);
 	}
 
 	bus_data_generation_update();
 	return (0);
 }
 
 /**
  * @brief Probe a device, and return this status.
  *
  * This function is the core of the device autoconfiguration
  * system. Its purpose is to select a suitable driver for a device and
  * then call that driver to initialise the hardware appropriately. The
  * driver is selected by calling the DEVICE_PROBE() method of a set of
  * candidate drivers and then choosing the driver which returned the
  * best value. This driver is then attached to the device using
  * device_attach().
  *
  * The set of suitable drivers is taken from the list of drivers in
  * the parent device's devclass. If the device was originally created
  * with a specific class name (see device_add_child()), only drivers
  * with that name are probed, otherwise all drivers in the devclass
  * are probed. If no drivers return successful probe values in the
  * parent devclass, the search continues in the parent of that
  * devclass (see devclass_get_parent()) if any.
  *
  * @param dev		the device to initialise
  *
  * @retval 0		success
  * @retval ENXIO	no driver was found
  * @retval ENOMEM	memory allocation failure
  * @retval non-zero	some other unix error code
  * @retval -1		Device already attached
  */
 int
 device_probe(device_t dev)
 {
 	int error;
 
 	bus_topo_assert();
 
 	if (dev->state >= DS_ALIVE)
 		return (-1);
 
 	if (!(dev->flags & DF_ENABLED)) {
 		if (bootverbose && device_get_name(dev) != NULL) {
 			device_print_prettyname(dev);
 			printf("not probed (disabled)\n");
 		}
 		return (-1);
 	}
 	if ((error = device_probe_child(dev->parent, dev)) != 0) {
 		if (bus_current_pass == BUS_PASS_DEFAULT &&
 		    !(dev->flags & DF_DONENOMATCH)) {
 			device_handle_nomatch(dev);
 		}
 		return (error);
 	}
 	return (0);
 }
 
 /**
  * @brief Probe a device and attach a driver if possible
  *
  * calls device_probe() and attaches if that was successful.
  */
 int
 device_probe_and_attach(device_t dev)
 {
 	int error;
 
 	bus_topo_assert();
 
 	error = device_probe(dev);
 	if (error == -1)
 		return (0);
 	else if (error != 0)
 		return (error);
 
 	return (device_attach(dev));
 }
 
 /**
  * @brief Attach a device driver to a device
  *
  * This function is a wrapper around the DEVICE_ATTACH() driver
  * method. In addition to calling DEVICE_ATTACH(), it initialises the
  * device's sysctl tree, optionally prints a description of the device
  * and queues a notification event for user-based device management
  * services.
  *
  * Normally this function is only called internally from
  * device_probe_and_attach().
  *
  * @param dev		the device to initialise
  *
  * @retval 0		success
  * @retval ENXIO	no driver was found
  * @retval ENOMEM	memory allocation failure
  * @retval non-zero	some other unix error code
  */
 int
 device_attach(device_t dev)
 {
 	uint64_t attachtime;
 	uint16_t attachentropy;
 	int error;
 
 	if (resource_disabled(dev->driver->name, dev->unit)) {
 		device_disable(dev);
 		if (bootverbose)
 			 device_printf(dev, "disabled via hints entry\n");
 		return (ENXIO);
 	}
 
 	KASSERT(IS_DEFAULT_VNET(TD_TO_VNET(curthread)),
 	    ("device_attach: curthread is not in default vnet"));
 	CURVNET_SET_QUIET(TD_TO_VNET(curthread));
 
 	device_sysctl_init(dev);
 	if (!device_is_quiet(dev))
 		device_print_child(dev->parent, dev);
 	attachtime = get_cyclecount();
 	dev->state = DS_ATTACHING;
 	if ((error = DEVICE_ATTACH(dev)) != 0) {
 		printf("device_attach: %s%d attach returned %d\n",
 		    dev->driver->name, dev->unit, error);
 		BUS_CHILD_DETACHED(dev->parent, dev);
 		if (disable_failed_devs) {
 			/*
 			 * When the user has asked to disable failed devices, we
 			 * directly disable the device, but leave it in the
 			 * attaching state. It will not try to probe/attach the
 			 * device further. This leaves the device numbering
 			 * intact for other similar devices in the system. It
 			 * can be removed from this state with devctl.
 			 */
 			device_disable(dev);
 		} else {
 			/*
 			 * Otherwise, when attach fails, tear down the state
 			 * around that so we can retry when, for example, new
 			 * drivers are loaded.
 			 */
 			if (!(dev->flags & DF_FIXEDCLASS))
 				devclass_delete_device(dev->devclass, dev);
 			(void)device_set_driver(dev, NULL);
 			device_sysctl_fini(dev);
 			KASSERT(dev->busy == 0, ("attach failed but busy"));
 			dev->state = DS_NOTPRESENT;
 		}
 		CURVNET_RESTORE();
 		return (error);
 	}
 	CURVNET_RESTORE();
 	dev->flags |= DF_ATTACHED_ONCE;
 	/*
 	 * We only need the low bits of this time, but ranges from tens to thousands
 	 * have been seen, so keep 2 bytes' worth.
 	 */
 	attachentropy = (uint16_t)(get_cyclecount() - attachtime);
 	random_harvest_direct(&attachentropy, sizeof(attachentropy), RANDOM_ATTACH);
 	device_sysctl_update(dev);
 	dev->state = DS_ATTACHED;
 	dev->flags &= ~DF_DONENOMATCH;
 	EVENTHANDLER_DIRECT_INVOKE(device_attach, dev);
 	return (0);
 }
 
 /**
  * @brief Detach a driver from a device
  *
  * This function is a wrapper around the DEVICE_DETACH() driver
  * method. If the call to DEVICE_DETACH() succeeds, it calls
  * BUS_CHILD_DETACHED() for the parent of @p dev, queues a
  * notification event for user-based device management services and
  * cleans up the device's sysctl tree.
  *
  * @param dev		the device to un-initialise
  *
  * @retval 0		success
  * @retval ENXIO	no driver was found
  * @retval ENOMEM	memory allocation failure
  * @retval non-zero	some other unix error code
  */
 int
 device_detach(device_t dev)
 {
 	int error;
 
 	bus_topo_assert();
 
 	PDEBUG(("%s", DEVICENAME(dev)));
 	if (dev->busy > 0)
 		return (EBUSY);
 	if (dev->state == DS_ATTACHING) {
 		device_printf(dev, "device in attaching state! Deferring detach.\n");
 		return (EBUSY);
 	}
 	if (dev->state != DS_ATTACHED)
 		return (0);
 
 	EVENTHANDLER_DIRECT_INVOKE(device_detach, dev, EVHDEV_DETACH_BEGIN);
 	if ((error = DEVICE_DETACH(dev)) != 0) {
 		EVENTHANDLER_DIRECT_INVOKE(device_detach, dev,
 		    EVHDEV_DETACH_FAILED);
 		return (error);
 	} else {
 		EVENTHANDLER_DIRECT_INVOKE(device_detach, dev,
 		    EVHDEV_DETACH_COMPLETE);
 	}
 	if (!device_is_quiet(dev))
 		device_printf(dev, "detached\n");
 	if (dev->parent)
 		BUS_CHILD_DETACHED(dev->parent, dev);
 
 	if (!(dev->flags & DF_FIXEDCLASS))
 		devclass_delete_device(dev->devclass, dev);
 
 	device_verbose(dev);
 	dev->state = DS_NOTPRESENT;
 	(void)device_set_driver(dev, NULL);
 	device_sysctl_fini(dev);
 
 	return (0);
 }
 
 /**
  * @brief Tells a driver to quiesce itself.
  *
  * This function is a wrapper around the DEVICE_QUIESCE() driver
  * method. If the call to DEVICE_QUIESCE() succeeds.
  *
  * @param dev		the device to quiesce
  *
  * @retval 0		success
  * @retval ENXIO	no driver was found
  * @retval ENOMEM	memory allocation failure
  * @retval non-zero	some other unix error code
  */
 int
 device_quiesce(device_t dev)
 {
 	PDEBUG(("%s", DEVICENAME(dev)));
 	if (dev->busy > 0)
 		return (EBUSY);
 	if (dev->state != DS_ATTACHED)
 		return (0);
 
 	return (DEVICE_QUIESCE(dev));
 }
 
 /**
  * @brief Notify a device of system shutdown
  *
  * This function calls the DEVICE_SHUTDOWN() driver method if the
  * device currently has an attached driver.
  *
  * @returns the value returned by DEVICE_SHUTDOWN()
  */
 int
 device_shutdown(device_t dev)
 {
 	if (dev->state < DS_ATTACHED)
 		return (0);
 	return (DEVICE_SHUTDOWN(dev));
 }
 
 /**
  * @brief Set the unit number of a device
  *
  * This function can be used to override the unit number used for a
  * device (e.g. to wire a device to a pre-configured unit number).
  */
 int
 device_set_unit(device_t dev, int unit)
 {
 	devclass_t dc;
 	int err;
 
 	if (unit == dev->unit)
 		return (0);
 	dc = device_get_devclass(dev);
 	if (unit < dc->maxunit && dc->devices[unit])
 		return (EBUSY);
 	err = devclass_delete_device(dc, dev);
 	if (err)
 		return (err);
 	dev->unit = unit;
 	err = devclass_add_device(dc, dev);
 	if (err)
 		return (err);
 
 	bus_data_generation_update();
 	return (0);
 }
 
 /*======================================*/
 /*
  * Some useful method implementations to make life easier for bus drivers.
  */
 
 /**
  * @brief Initialize a resource mapping request
  *
  * This is the internal implementation of the public API
  * resource_init_map_request.  Callers may be using a different layout
  * of struct resource_map_request than the kernel, so callers pass in
  * the size of the structure they are using to identify the structure
  * layout.
  */
 void
 resource_init_map_request_impl(struct resource_map_request *args, size_t sz)
 {
 	bzero(args, sz);
 	args->size = sz;
 	args->memattr = VM_MEMATTR_DEVICE;
 }
 
 /**
  * @brief Validate a resource mapping request
  *
  * Translate a device driver's mapping request (@p in) to a struct
  * resource_map_request using the current structure layout (@p out).
  * In addition, validate the offset and length from the mapping
  * request against the bounds of the resource @p r.  If the offset or
  * length are invalid, fail with EINVAL.  If the offset and length are
  * valid, the absolute starting address of the requested mapping is
  * returned in @p startp and the length of the requested mapping is
  * returned in @p lengthp.
  */
 int
 resource_validate_map_request(struct resource *r,
     struct resource_map_request *in, struct resource_map_request *out,
     rman_res_t *startp, rman_res_t *lengthp)
 {
 	rman_res_t end, length, start;
 
 	/*
 	 * This assumes that any callers of this function are compiled
 	 * into the kernel and use the same version of the structure
 	 * as this file.
 	 */
 	MPASS(out->size == sizeof(struct resource_map_request));
 
 	if (in != NULL)
 		bcopy(in, out, imin(in->size, out->size));
 	start = rman_get_start(r) + out->offset;
 	if (out->length == 0)
 		length = rman_get_size(r);
 	else
 		length = out->length;
 	end = start + length - 1;
 	if (start > rman_get_end(r) || start < rman_get_start(r))
 		return (EINVAL);
 	if (end > rman_get_end(r) || end < start)
 		return (EINVAL);
 	*lengthp = length;
 	*startp = start;
 	return (0);
 }
 
 /**
  * @brief Initialise a resource list.
  *
  * @param rl		the resource list to initialise
  */
 void
 resource_list_init(struct resource_list *rl)
 {
 	STAILQ_INIT(rl);
 }
 
 /**
  * @brief Reclaim memory used by a resource list.
  *
  * This function frees the memory for all resource entries on the list
  * (if any).
  *
  * @param rl		the resource list to free
  */
 void
 resource_list_free(struct resource_list *rl)
 {
 	struct resource_list_entry *rle;
 
 	while ((rle = STAILQ_FIRST(rl)) != NULL) {
 		if (rle->res)
 			panic("resource_list_free: resource entry is busy");
 		STAILQ_REMOVE_HEAD(rl, link);
 		free(rle, M_BUS);
 	}
 }
 
 /**
  * @brief Add a resource entry.
  *
  * This function adds a resource entry using the given @p type, @p
  * start, @p end and @p count values. A rid value is chosen by
  * searching sequentially for the first unused rid starting at zero.
  *
  * @param rl		the resource list to edit
  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
  * @param start		the start address of the resource
  * @param end		the end address of the resource
  * @param count		XXX end-start+1
  */
 int
 resource_list_add_next(struct resource_list *rl, int type, rman_res_t start,
     rman_res_t end, rman_res_t count)
 {
 	int rid;
 
 	rid = 0;
 	while (resource_list_find(rl, type, rid) != NULL)
 		rid++;
 	resource_list_add(rl, type, rid, start, end, count);
 	return (rid);
 }
 
 /**
  * @brief Add or modify a resource entry.
  *
  * If an existing entry exists with the same type and rid, it will be
  * modified using the given values of @p start, @p end and @p
  * count. If no entry exists, a new one will be created using the
  * given values.  The resource list entry that matches is then returned.
  *
  * @param rl		the resource list to edit
  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
  * @param rid		the resource identifier
  * @param start		the start address of the resource
  * @param end		the end address of the resource
  * @param count		XXX end-start+1
  */
 struct resource_list_entry *
 resource_list_add(struct resource_list *rl, int type, int rid,
     rman_res_t start, rman_res_t end, rman_res_t count)
 {
 	struct resource_list_entry *rle;
 
 	rle = resource_list_find(rl, type, rid);
 	if (!rle) {
 		rle = malloc(sizeof(struct resource_list_entry), M_BUS,
 		    M_NOWAIT);
 		if (!rle)
 			panic("resource_list_add: can't record entry");
 		STAILQ_INSERT_TAIL(rl, rle, link);
 		rle->type = type;
 		rle->rid = rid;
 		rle->res = NULL;
 		rle->flags = 0;
 	}
 
 	if (rle->res)
 		panic("resource_list_add: resource entry is busy");
 
 	rle->start = start;
 	rle->end = end;
 	rle->count = count;
 	return (rle);
 }
 
 /**
  * @brief Determine if a resource entry is busy.
  *
  * Returns true if a resource entry is busy meaning that it has an
  * associated resource that is not an unallocated "reserved" resource.
  *
  * @param rl		the resource list to search
  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
  * @param rid		the resource identifier
  *
  * @returns Non-zero if the entry is busy, zero otherwise.
  */
 int
 resource_list_busy(struct resource_list *rl, int type, int rid)
 {
 	struct resource_list_entry *rle;
 
 	rle = resource_list_find(rl, type, rid);
 	if (rle == NULL || rle->res == NULL)
 		return (0);
 	if ((rle->flags & (RLE_RESERVED | RLE_ALLOCATED)) == RLE_RESERVED) {
 		KASSERT(!(rman_get_flags(rle->res) & RF_ACTIVE),
 		    ("reserved resource is active"));
 		return (0);
 	}
 	return (1);
 }
 
 /**
  * @brief Determine if a resource entry is reserved.
  *
  * Returns true if a resource entry is reserved meaning that it has an
  * associated "reserved" resource.  The resource can either be
  * allocated or unallocated.
  *
  * @param rl		the resource list to search
  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
  * @param rid		the resource identifier
  *
  * @returns Non-zero if the entry is reserved, zero otherwise.
  */
 int
 resource_list_reserved(struct resource_list *rl, int type, int rid)
 {
 	struct resource_list_entry *rle;
 
 	rle = resource_list_find(rl, type, rid);
 	if (rle != NULL && rle->flags & RLE_RESERVED)
 		return (1);
 	return (0);
 }
 
 /**
  * @brief Find a resource entry by type and rid.
  *
  * @param rl		the resource list to search
  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
  * @param rid		the resource identifier
  *
  * @returns the resource entry pointer or NULL if there is no such
  * entry.
  */
 struct resource_list_entry *
 resource_list_find(struct resource_list *rl, int type, int rid)
 {
 	struct resource_list_entry *rle;
 
 	STAILQ_FOREACH(rle, rl, link) {
 		if (rle->type == type && rle->rid == rid)
 			return (rle);
 	}
 	return (NULL);
 }
 
 /**
  * @brief Delete a resource entry.
  *
  * @param rl		the resource list to edit
  * @param type		the resource entry type (e.g. SYS_RES_MEMORY)
  * @param rid		the resource identifier
  */
 void
 resource_list_delete(struct resource_list *rl, int type, int rid)
 {
 	struct resource_list_entry *rle = resource_list_find(rl, type, rid);
 
 	if (rle) {
 		if (rle->res != NULL)
 			panic("resource_list_delete: resource has not been released");
 		STAILQ_REMOVE(rl, rle, resource_list_entry, link);
 		free(rle, M_BUS);
 	}
 }
 
 /**
  * @brief Allocate a reserved resource
  *
  * This can be used by buses to force the allocation of resources
  * that are always active in the system even if they are not allocated
  * by a driver (e.g. PCI BARs).  This function is usually called when
  * adding a new child to the bus.  The resource is allocated from the
  * parent bus when it is reserved.  The resource list entry is marked
  * with RLE_RESERVED to note that it is a reserved resource.
  *
  * Subsequent attempts to allocate the resource with
  * resource_list_alloc() will succeed the first time and will set
  * RLE_ALLOCATED to note that it has been allocated.  When a reserved
  * resource that has been allocated is released with
  * resource_list_release() the resource RLE_ALLOCATED is cleared, but
  * the actual resource remains allocated.  The resource can be released to
  * the parent bus by calling resource_list_unreserve().
  *
  * @param rl		the resource list to allocate from
  * @param bus		the parent device of @p child
  * @param child		the device for which the resource is being reserved
  * @param type		the type of resource to allocate
  * @param rid		a pointer to the resource identifier
  * @param start		hint at the start of the resource range - pass
  *			@c 0 for any start address
  * @param end		hint at the end of the resource range - pass
  *			@c ~0 for any end address
  * @param count		hint at the size of range required - pass @c 1
  *			for any size
  * @param flags		any extra flags to control the resource
  *			allocation - see @c RF_XXX flags in
  *			<sys/rman.h> for details
  *
  * @returns		the resource which was allocated or @c NULL if no
  *			resource could be allocated
  */
 struct resource *
 resource_list_reserve(struct resource_list *rl, device_t bus, device_t child,
     int type, int *rid, rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
 {
 	struct resource_list_entry *rle = NULL;
 	int passthrough = (device_get_parent(child) != bus);
 	struct resource *r;
 
 	if (passthrough)
 		panic(
     "resource_list_reserve() should only be called for direct children");
 	if (flags & RF_ACTIVE)
 		panic(
     "resource_list_reserve() should only reserve inactive resources");
 
 	r = resource_list_alloc(rl, bus, child, type, rid, start, end, count,
 	    flags);
 	if (r != NULL) {
 		rle = resource_list_find(rl, type, *rid);
 		rle->flags |= RLE_RESERVED;
 	}
 	return (r);
 }
 
 /**
  * @brief Helper function for implementing BUS_ALLOC_RESOURCE()
  *
  * Implement BUS_ALLOC_RESOURCE() by looking up a resource from the list
  * and passing the allocation up to the parent of @p bus. This assumes
  * that the first entry of @c device_get_ivars(child) is a struct
  * resource_list. This also handles 'passthrough' allocations where a
  * child is a remote descendant of bus by passing the allocation up to
  * the parent of bus.
  *
  * Typically, a bus driver would store a list of child resources
  * somewhere in the child device's ivars (see device_get_ivars()) and
  * its implementation of BUS_ALLOC_RESOURCE() would find that list and
  * then call resource_list_alloc() to perform the allocation.
  *
  * @param rl		the resource list to allocate from
  * @param bus		the parent device of @p child
  * @param child		the device which is requesting an allocation
  * @param type		the type of resource to allocate
  * @param rid		a pointer to the resource identifier
  * @param start		hint at the start of the resource range - pass
  *			@c 0 for any start address
  * @param end		hint at the end of the resource range - pass
  *			@c ~0 for any end address
  * @param count		hint at the size of range required - pass @c 1
  *			for any size
  * @param flags		any extra flags to control the resource
  *			allocation - see @c RF_XXX flags in
  *			<sys/rman.h> for details
  *
  * @returns		the resource which was allocated or @c NULL if no
  *			resource could be allocated
  */
 struct resource *
 resource_list_alloc(struct resource_list *rl, device_t bus, device_t child,
     int type, int *rid, rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
 {
 	struct resource_list_entry *rle = NULL;
 	int passthrough = (device_get_parent(child) != bus);
 	int isdefault = RMAN_IS_DEFAULT_RANGE(start, end);
 
 	if (passthrough) {
 		return (BUS_ALLOC_RESOURCE(device_get_parent(bus), child,
 		    type, rid, start, end, count, flags));
 	}
 
 	rle = resource_list_find(rl, type, *rid);
 
 	if (!rle)
 		return (NULL);		/* no resource of that type/rid */
 
 	if (rle->res) {
 		if (rle->flags & RLE_RESERVED) {
 			if (rle->flags & RLE_ALLOCATED)
 				return (NULL);
 			if ((flags & RF_ACTIVE) &&
 			    bus_activate_resource(child, type, *rid,
 			    rle->res) != 0)
 				return (NULL);
 			rle->flags |= RLE_ALLOCATED;
 			return (rle->res);
 		}
 		device_printf(bus,
 		    "resource entry %#x type %d for child %s is busy\n", *rid,
 		    type, device_get_nameunit(child));
 		return (NULL);
 	}
 
 	if (isdefault) {
 		start = rle->start;
 		count = ulmax(count, rle->count);
 		end = ulmax(rle->end, start + count - 1);
 	}
 
 	rle->res = BUS_ALLOC_RESOURCE(device_get_parent(bus), child,
 	    type, rid, start, end, count, flags);
 
 	/*
 	 * Record the new range.
 	 */
 	if (rle->res) {
 		rle->start = rman_get_start(rle->res);
 		rle->end = rman_get_end(rle->res);
 		rle->count = count;
 	}
 
 	return (rle->res);
 }
 
 /**
  * @brief Helper function for implementing BUS_RELEASE_RESOURCE()
  *
  * Implement BUS_RELEASE_RESOURCE() using a resource list. Normally
  * used with resource_list_alloc().
  *
  * @param rl		the resource list which was allocated from
  * @param bus		the parent device of @p child
  * @param child		the device which is requesting a release
  * @param type		the type of resource to release
  * @param rid		the resource identifier
  * @param res		the resource to release
  *
  * @retval 0		success
  * @retval non-zero	a standard unix error code indicating what
  *			error condition prevented the operation
  */
 int
 resource_list_release(struct resource_list *rl, device_t bus, device_t child,
     int type, int rid, struct resource *res)
 {
 	struct resource_list_entry *rle = NULL;
 	int passthrough = (device_get_parent(child) != bus);
 	int error;
 
 	if (passthrough) {
 		return (BUS_RELEASE_RESOURCE(device_get_parent(bus), child,
 		    type, rid, res));
 	}
 
 	rle = resource_list_find(rl, type, rid);
 
 	if (!rle)
 		panic("resource_list_release: can't find resource");
 	if (!rle->res)
 		panic("resource_list_release: resource entry is not busy");
 	if (rle->flags & RLE_RESERVED) {
 		if (rle->flags & RLE_ALLOCATED) {
 			if (rman_get_flags(res) & RF_ACTIVE) {
 				error = bus_deactivate_resource(child, type,
 				    rid, res);
 				if (error)
 					return (error);
 			}
 			rle->flags &= ~RLE_ALLOCATED;
 			return (0);
 		}
 		return (EINVAL);
 	}
 
 	error = BUS_RELEASE_RESOURCE(device_get_parent(bus), child,
 	    type, rid, res);
 	if (error)
 		return (error);
 
 	rle->res = NULL;
 	return (0);
 }
 
 /**
  * @brief Release all active resources of a given type
  *
  * Release all active resources of a specified type.  This is intended
  * to be used to cleanup resources leaked by a driver after detach or
  * a failed attach.
  *
  * @param rl		the resource list which was allocated from
  * @param bus		the parent device of @p child
  * @param child		the device whose active resources are being released
  * @param type		the type of resources to release
  *
  * @retval 0		success
  * @retval EBUSY	at least one resource was active
  */
 int
 resource_list_release_active(struct resource_list *rl, device_t bus,
     device_t child, int type)
 {
 	struct resource_list_entry *rle;
 	int error, retval;
 
 	retval = 0;
 	STAILQ_FOREACH(rle, rl, link) {
 		if (rle->type != type)
 			continue;
 		if (rle->res == NULL)
 			continue;
 		if ((rle->flags & (RLE_RESERVED | RLE_ALLOCATED)) ==
 		    RLE_RESERVED)
 			continue;
 		retval = EBUSY;
 		error = resource_list_release(rl, bus, child, type,
 		    rman_get_rid(rle->res), rle->res);
 		if (error != 0)
 			device_printf(bus,
 			    "Failed to release active resource: %d\n", error);
 	}
 	return (retval);
 }
 
 /**
  * @brief Fully release a reserved resource
  *
  * Fully releases a resource reserved via resource_list_reserve().
  *
  * @param rl		the resource list which was allocated from
  * @param bus		the parent device of @p child
  * @param child		the device whose reserved resource is being released
  * @param type		the type of resource to release
  * @param rid		the resource identifier
  * @param res		the resource to release
  *
  * @retval 0		success
  * @retval non-zero	a standard unix error code indicating what
  *			error condition prevented the operation
  */
 int
 resource_list_unreserve(struct resource_list *rl, device_t bus, device_t child,
     int type, int rid)
 {
 	struct resource_list_entry *rle = NULL;
 	int passthrough = (device_get_parent(child) != bus);
 
 	if (passthrough)
 		panic(
     "resource_list_unreserve() should only be called for direct children");
 
 	rle = resource_list_find(rl, type, rid);
 
 	if (!rle)
 		panic("resource_list_unreserve: can't find resource");
 	if (!(rle->flags & RLE_RESERVED))
 		return (EINVAL);
 	if (rle->flags & RLE_ALLOCATED)
 		return (EBUSY);
 	rle->flags &= ~RLE_RESERVED;
 	return (resource_list_release(rl, bus, child, type, rid, rle->res));
 }
 
 /**
  * @brief Print a description of resources in a resource list
  *
  * Print all resources of a specified type, for use in BUS_PRINT_CHILD().
  * The name is printed if at least one resource of the given type is available.
  * The format is used to print resource start and end.
  *
  * @param rl		the resource list to print
  * @param name		the name of @p type, e.g. @c "memory"
  * @param type		type type of resource entry to print
  * @param format	printf(9) format string to print resource
  *			start and end values
  *
  * @returns		the number of characters printed
  */
 int
 resource_list_print_type(struct resource_list *rl, const char *name, int type,
     const char *format)
 {
 	struct resource_list_entry *rle;
 	int printed, retval;
 
 	printed = 0;
 	retval = 0;
 	/* Yes, this is kinda cheating */
 	STAILQ_FOREACH(rle, rl, link) {
 		if (rle->type == type) {
 			if (printed == 0)
 				retval += printf(" %s ", name);
 			else
 				retval += printf(",");
 			printed++;
 			retval += printf(format, rle->start);
 			if (rle->count > 1) {
 				retval += printf("-");
 				retval += printf(format, rle->start +
 						 rle->count - 1);
 			}
 		}
 	}
 	return (retval);
 }
 
 /**
  * @brief Releases all the resources in a list.
  *
  * @param rl		The resource list to purge.
  *
  * @returns		nothing
  */
 void
 resource_list_purge(struct resource_list *rl)
 {
 	struct resource_list_entry *rle;
 
 	while ((rle = STAILQ_FIRST(rl)) != NULL) {
 		if (rle->res)
 			bus_release_resource(rman_get_device(rle->res),
 			    rle->type, rle->rid, rle->res);
 		STAILQ_REMOVE_HEAD(rl, link);
 		free(rle, M_BUS);
 	}
 }
 
 device_t
 bus_generic_add_child(device_t dev, u_int order, const char *name, int unit)
 {
 	return (device_add_child_ordered(dev, order, name, unit));
 }
 
 /**
  * @brief Helper function for implementing DEVICE_PROBE()
  *
  * This function can be used to help implement the DEVICE_PROBE() for
  * a bus (i.e. a device which has other devices attached to it). It
  * calls the DEVICE_IDENTIFY() method of each driver in the device's
  * devclass.
  */
 int
 bus_generic_probe(device_t dev)
 {
 	devclass_t dc = dev->devclass;
 	driverlink_t dl;
 
 	TAILQ_FOREACH(dl, &dc->drivers, link) {
 		/*
 		 * If this driver's pass is too high, then ignore it.
 		 * For most drivers in the default pass, this will
 		 * never be true.  For early-pass drivers they will
 		 * only call the identify routines of eligible drivers
 		 * when this routine is called.  Drivers for later
 		 * passes should have their identify routines called
 		 * on early-pass buses during BUS_NEW_PASS().
 		 */
 		if (dl->pass > bus_current_pass)
 			continue;
 		DEVICE_IDENTIFY(dl->driver, dev);
 	}
 
 	return (0);
 }
 
 /**
  * @brief Helper function for implementing DEVICE_ATTACH()
  *
  * This function can be used to help implement the DEVICE_ATTACH() for
  * a bus. It calls device_probe_and_attach() for each of the device's
  * children.
  */
 int
 bus_generic_attach(device_t dev)
 {
 	device_t child;
 
 	TAILQ_FOREACH(child, &dev->children, link) {
 		device_probe_and_attach(child);
 	}
 
 	return (0);
 }
 
 /**
  * @brief Helper function for delaying attaching children
  *
  * Many buses can't run transactions on the bus which children need to probe and
  * attach until after interrupts and/or timers are running.  This function
  * delays their attach until interrupts and timers are enabled.
  */
 int
 bus_delayed_attach_children(device_t dev)
 {
 	/* Probe and attach the bus children when interrupts are available */
 	config_intrhook_oneshot((ich_func_t)bus_generic_attach, dev);
 
 	return (0);
 }
 
 /**
  * @brief Helper function for implementing DEVICE_DETACH()
  *
  * This function can be used to help implement the DEVICE_DETACH() for
  * a bus. It calls device_detach() for each of the device's
  * children.
  */
 int
 bus_generic_detach(device_t dev)
 {
 	device_t child;
 	int error;
 
-	if (dev->state != DS_ATTACHED)
-		return (EBUSY);
-
 	/*
 	 * Detach children in the reverse order.
 	 * See bus_generic_suspend for details.
 	 */
 	TAILQ_FOREACH_REVERSE(child, &dev->children, device_list, link) {
 		if ((error = device_detach(child)) != 0)
 			return (error);
 	}
 
 	return (0);
 }
 
 /**
  * @brief Helper function for implementing DEVICE_SHUTDOWN()
  *
  * This function can be used to help implement the DEVICE_SHUTDOWN()
  * for a bus. It calls device_shutdown() for each of the device's
  * children.
  */
 int
 bus_generic_shutdown(device_t dev)
 {
 	device_t child;
 
 	/*
 	 * Shut down children in the reverse order.
 	 * See bus_generic_suspend for details.
 	 */
 	TAILQ_FOREACH_REVERSE(child, &dev->children, device_list, link) {
 		device_shutdown(child);
 	}
 
 	return (0);
 }
 
 /**
  * @brief Default function for suspending a child device.
  *
  * This function is to be used by a bus's DEVICE_SUSPEND_CHILD().
  */
 int
 bus_generic_suspend_child(device_t dev, device_t child)
 {
 	int	error;
 
 	error = DEVICE_SUSPEND(child);
 
 	if (error == 0) {
 		child->flags |= DF_SUSPENDED;
 	} else {
 		printf("DEVICE_SUSPEND(%s) failed: %d\n",
 		    device_get_nameunit(child), error);
 	}
 
 	return (error);
 }
 
 /**
  * @brief Default function for resuming a child device.
  *
  * This function is to be used by a bus's DEVICE_RESUME_CHILD().
  */
 int
 bus_generic_resume_child(device_t dev, device_t child)
 {
 	DEVICE_RESUME(child);
 	child->flags &= ~DF_SUSPENDED;
 
 	return (0);
 }
 
 /**
  * @brief Helper function for implementing DEVICE_SUSPEND()
  *
  * This function can be used to help implement the DEVICE_SUSPEND()
  * for a bus. It calls DEVICE_SUSPEND() for each of the device's
  * children. If any call to DEVICE_SUSPEND() fails, the suspend
  * operation is aborted and any devices which were suspended are
  * resumed immediately by calling their DEVICE_RESUME() methods.
  */
 int
 bus_generic_suspend(device_t dev)
 {
 	int		error;
 	device_t	child;
 
 	/*
 	 * Suspend children in the reverse order.
 	 * For most buses all children are equal, so the order does not matter.
 	 * Other buses, such as acpi, carefully order their child devices to
 	 * express implicit dependencies between them.  For such buses it is
 	 * safer to bring down devices in the reverse order.
 	 */
 	TAILQ_FOREACH_REVERSE(child, &dev->children, device_list, link) {
 		error = BUS_SUSPEND_CHILD(dev, child);
 		if (error != 0) {
 			child = TAILQ_NEXT(child, link);
 			if (child != NULL) {
 				TAILQ_FOREACH_FROM(child, &dev->children, link)
 					BUS_RESUME_CHILD(dev, child);
 			}
 			return (error);
 		}
 	}
 	return (0);
 }
 
 /**
  * @brief Helper function for implementing DEVICE_RESUME()
  *
  * This function can be used to help implement the DEVICE_RESUME() for
  * a bus. It calls DEVICE_RESUME() on each of the device's children.
  */
 int
 bus_generic_resume(device_t dev)
 {
 	device_t	child;
 
 	TAILQ_FOREACH(child, &dev->children, link) {
 		BUS_RESUME_CHILD(dev, child);
 		/* if resume fails, there's nothing we can usefully do... */
 	}
 	return (0);
 }
 
 /**
  * @brief Helper function for implementing BUS_RESET_POST
  *
  * Bus can use this function to implement common operations of
  * re-attaching or resuming the children after the bus itself was
  * reset, and after restoring bus-unique state of children.
  *
  * @param dev	The bus
  * #param flags	DEVF_RESET_*
  */
 int
 bus_helper_reset_post(device_t dev, int flags)
 {
 	device_t child;
 	int error, error1;
 
 	error = 0;
 	TAILQ_FOREACH(child, &dev->children,link) {
 		BUS_RESET_POST(dev, child);
 		error1 = (flags & DEVF_RESET_DETACH) != 0 ?
 		    device_probe_and_attach(child) :
 		    BUS_RESUME_CHILD(dev, child);
 		if (error == 0 && error1 != 0)
 			error = error1;
 	}
 	return (error);
 }
 
 static void
 bus_helper_reset_prepare_rollback(device_t dev, device_t child, int flags)
 {
 	child = TAILQ_NEXT(child, link);
 	if (child == NULL)
 		return;
 	TAILQ_FOREACH_FROM(child, &dev->children,link) {
 		BUS_RESET_POST(dev, child);
 		if ((flags & DEVF_RESET_DETACH) != 0)
 			device_probe_and_attach(child);
 		else
 			BUS_RESUME_CHILD(dev, child);
 	}
 }
 
 /**
  * @brief Helper function for implementing BUS_RESET_PREPARE
  *
  * Bus can use this function to implement common operations of
  * detaching or suspending the children before the bus itself is
  * reset, and then save bus-unique state of children that must
  * persists around reset.
  *
  * @param dev	The bus
  * #param flags	DEVF_RESET_*
  */
 int
 bus_helper_reset_prepare(device_t dev, int flags)
 {
 	device_t child;
 	int error;
 
 	if (dev->state != DS_ATTACHED)
 		return (EBUSY);
 
 	TAILQ_FOREACH_REVERSE(child, &dev->children, device_list, link) {
 		if ((flags & DEVF_RESET_DETACH) != 0) {
 			error = device_get_state(child) == DS_ATTACHED ?
 			    device_detach(child) : 0;
 		} else {
 			error = BUS_SUSPEND_CHILD(dev, child);
 		}
 		if (error == 0) {
 			error = BUS_RESET_PREPARE(dev, child);
 			if (error != 0) {
 				if ((flags & DEVF_RESET_DETACH) != 0)
 					device_probe_and_attach(child);
 				else
 					BUS_RESUME_CHILD(dev, child);
 			}
 		}
 		if (error != 0) {
 			bus_helper_reset_prepare_rollback(dev, child, flags);
 			return (error);
 		}
 	}
 	return (0);
 }
 
 /**
  * @brief Helper function for implementing BUS_PRINT_CHILD().
  *
  * This function prints the first part of the ascii representation of
  * @p child, including its name, unit and description (if any - see
  * device_set_desc()).
  *
  * @returns the number of characters printed
  */
 int
 bus_print_child_header(device_t dev, device_t child)
 {
 	int	retval = 0;
 
 	if (device_get_desc(child)) {
 		retval += device_printf(child, "<%s>", device_get_desc(child));
 	} else {
 		retval += printf("%s", device_get_nameunit(child));
 	}
 
 	return (retval);
 }
 
 /**
  * @brief Helper function for implementing BUS_PRINT_CHILD().
  *
  * This function prints the last part of the ascii representation of
  * @p child, which consists of the string @c " on " followed by the
  * name and unit of the @p dev.
  *
  * @returns the number of characters printed
  */
 int
 bus_print_child_footer(device_t dev, device_t child)
 {
 	return (printf(" on %s\n", device_get_nameunit(dev)));
 }
 
 /**
  * @brief Helper function for implementing BUS_PRINT_CHILD().
  *
  * This function prints out the VM domain for the given device.
  *
  * @returns the number of characters printed
  */
 int
 bus_print_child_domain(device_t dev, device_t child)
 {
 	int domain;
 
 	/* No domain? Don't print anything */
 	if (BUS_GET_DOMAIN(dev, child, &domain) != 0)
 		return (0);
 
 	return (printf(" numa-domain %d", domain));
 }
 
 /**
  * @brief Helper function for implementing BUS_PRINT_CHILD().
  *
  * This function simply calls bus_print_child_header() followed by
  * bus_print_child_footer().
  *
  * @returns the number of characters printed
  */
 int
 bus_generic_print_child(device_t dev, device_t child)
 {
 	int	retval = 0;
 
 	retval += bus_print_child_header(dev, child);
 	retval += bus_print_child_domain(dev, child);
 	retval += bus_print_child_footer(dev, child);
 
 	return (retval);
 }
 
 /**
  * @brief Stub function for implementing BUS_READ_IVAR().
  *
  * @returns ENOENT
  */
 int
 bus_generic_read_ivar(device_t dev, device_t child, int index,
     uintptr_t * result)
 {
 	return (ENOENT);
 }
 
 /**
  * @brief Stub function for implementing BUS_WRITE_IVAR().
  *
  * @returns ENOENT
  */
 int
 bus_generic_write_ivar(device_t dev, device_t child, int index,
     uintptr_t value)
 {
 	return (ENOENT);
 }
 
 /**
  * @brief Helper function for implementing BUS_GET_PROPERTY().
  *
  * This simply calls the BUS_GET_PROPERTY of the parent of dev,
  * until a non-default implementation is found.
  */
 ssize_t
 bus_generic_get_property(device_t dev, device_t child, const char *propname,
     void *propvalue, size_t size, device_property_type_t type)
 {
 	if (device_get_parent(dev) != NULL)
 		return (BUS_GET_PROPERTY(device_get_parent(dev), child,
 		    propname, propvalue, size, type));
 
 	return (-1);
 }
 
 /**
  * @brief Stub function for implementing BUS_GET_RESOURCE_LIST().
  *
  * @returns NULL
  */
 struct resource_list *
 bus_generic_get_resource_list(device_t dev, device_t child)
 {
 	return (NULL);
 }
 
 /**
  * @brief Helper function for implementing BUS_DRIVER_ADDED().
  *
  * This implementation of BUS_DRIVER_ADDED() simply calls the driver's
  * DEVICE_IDENTIFY() method to allow it to add new children to the bus
  * and then calls device_probe_and_attach() for each unattached child.
  */
 void
 bus_generic_driver_added(device_t dev, driver_t *driver)
 {
 	device_t child;
 
 	DEVICE_IDENTIFY(driver, dev);
 	TAILQ_FOREACH(child, &dev->children, link) {
 		if (child->state == DS_NOTPRESENT)
 			device_probe_and_attach(child);
 	}
 }
 
 /**
  * @brief Helper function for implementing BUS_NEW_PASS().
  *
  * This implementing of BUS_NEW_PASS() first calls the identify
  * routines for any drivers that probe at the current pass.  Then it
  * walks the list of devices for this bus.  If a device is already
  * attached, then it calls BUS_NEW_PASS() on that device.  If the
  * device is not already attached, it attempts to attach a driver to
  * it.
  */
 void
 bus_generic_new_pass(device_t dev)
 {
 	driverlink_t dl;
 	devclass_t dc;
 	device_t child;
 
 	dc = dev->devclass;
 	TAILQ_FOREACH(dl, &dc->drivers, link) {
 		if (dl->pass == bus_current_pass)
 			DEVICE_IDENTIFY(dl->driver, dev);
 	}
 	TAILQ_FOREACH(child, &dev->children, link) {
 		if (child->state >= DS_ATTACHED)
 			BUS_NEW_PASS(child);
 		else if (child->state == DS_NOTPRESENT)
 			device_probe_and_attach(child);
 	}
 }
 
 /**
  * @brief Helper function for implementing BUS_SETUP_INTR().
  *
  * This simple implementation of BUS_SETUP_INTR() simply calls the
  * BUS_SETUP_INTR() method of the parent of @p dev.
  */
 int
 bus_generic_setup_intr(device_t dev, device_t child, struct resource *irq,
     int flags, driver_filter_t *filter, driver_intr_t *intr, void *arg,
     void **cookiep)
 {
 	/* Propagate up the bus hierarchy until someone handles it. */
 	if (dev->parent)
 		return (BUS_SETUP_INTR(dev->parent, child, irq, flags,
 		    filter, intr, arg, cookiep));
 	return (EINVAL);
 }
 
 /**
  * @brief Helper function for implementing BUS_TEARDOWN_INTR().
  *
  * This simple implementation of BUS_TEARDOWN_INTR() simply calls the
  * BUS_TEARDOWN_INTR() method of the parent of @p dev.
  */
 int
 bus_generic_teardown_intr(device_t dev, device_t child, struct resource *irq,
     void *cookie)
 {
 	/* Propagate up the bus hierarchy until someone handles it. */
 	if (dev->parent)
 		return (BUS_TEARDOWN_INTR(dev->parent, child, irq, cookie));
 	return (EINVAL);
 }
 
 /**
  * @brief Helper function for implementing BUS_SUSPEND_INTR().
  *
  * This simple implementation of BUS_SUSPEND_INTR() simply calls the
  * BUS_SUSPEND_INTR() method of the parent of @p dev.
  */
 int
 bus_generic_suspend_intr(device_t dev, device_t child, struct resource *irq)
 {
 	/* Propagate up the bus hierarchy until someone handles it. */
 	if (dev->parent)
 		return (BUS_SUSPEND_INTR(dev->parent, child, irq));
 	return (EINVAL);
 }
 
 /**
  * @brief Helper function for implementing BUS_RESUME_INTR().
  *
  * This simple implementation of BUS_RESUME_INTR() simply calls the
  * BUS_RESUME_INTR() method of the parent of @p dev.
  */
 int
 bus_generic_resume_intr(device_t dev, device_t child, struct resource *irq)
 {
 	/* Propagate up the bus hierarchy until someone handles it. */
 	if (dev->parent)
 		return (BUS_RESUME_INTR(dev->parent, child, irq));
 	return (EINVAL);
 }
 
 /**
  * @brief Helper function for implementing BUS_ADJUST_RESOURCE().
  *
  * This simple implementation of BUS_ADJUST_RESOURCE() simply calls the
  * BUS_ADJUST_RESOURCE() method of the parent of @p dev.
  */
 int
 bus_generic_adjust_resource(device_t dev, device_t child, int type,
     struct resource *r, rman_res_t start, rman_res_t end)
 {
 	/* Propagate up the bus hierarchy until someone handles it. */
 	if (dev->parent)
 		return (BUS_ADJUST_RESOURCE(dev->parent, child, type, r, start,
 		    end));
 	return (EINVAL);
 }
 
 /*
  * @brief Helper function for implementing BUS_TRANSLATE_RESOURCE().
  *
  * This simple implementation of BUS_TRANSLATE_RESOURCE() simply calls the
  * BUS_TRANSLATE_RESOURCE() method of the parent of @p dev.  If there is no
  * parent, no translation happens.
  */
 int
 bus_generic_translate_resource(device_t dev, int type, rman_res_t start,
     rman_res_t *newstart)
 {
 	if (dev->parent)
 		return (BUS_TRANSLATE_RESOURCE(dev->parent, type, start,
 		    newstart));
 	*newstart = start;
 	return (0);
 }
 
 /**
  * @brief Helper function for implementing BUS_ALLOC_RESOURCE().
  *
  * This simple implementation of BUS_ALLOC_RESOURCE() simply calls the
  * BUS_ALLOC_RESOURCE() method of the parent of @p dev.
  */
 struct resource *
 bus_generic_alloc_resource(device_t dev, device_t child, int type, int *rid,
     rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
 {
 	/* Propagate up the bus hierarchy until someone handles it. */
 	if (dev->parent)
 		return (BUS_ALLOC_RESOURCE(dev->parent, child, type, rid,
 		    start, end, count, flags));
 	return (NULL);
 }
 
 /**
  * @brief Helper function for implementing BUS_RELEASE_RESOURCE().
  *
  * This simple implementation of BUS_RELEASE_RESOURCE() simply calls the
  * BUS_RELEASE_RESOURCE() method of the parent of @p dev.
  */
 int
 bus_generic_release_resource(device_t dev, device_t child, int type, int rid,
     struct resource *r)
 {
 	/* Propagate up the bus hierarchy until someone handles it. */
 	if (dev->parent)
 		return (BUS_RELEASE_RESOURCE(dev->parent, child, type, rid,
 		    r));
 	return (EINVAL);
 }
 
 /**
  * @brief Helper function for implementing BUS_ACTIVATE_RESOURCE().
  *
  * This simple implementation of BUS_ACTIVATE_RESOURCE() simply calls the
  * BUS_ACTIVATE_RESOURCE() method of the parent of @p dev.
  */
 int
 bus_generic_activate_resource(device_t dev, device_t child, int type, int rid,
     struct resource *r)
 {
 	/* Propagate up the bus hierarchy until someone handles it. */
 	if (dev->parent)
 		return (BUS_ACTIVATE_RESOURCE(dev->parent, child, type, rid,
 		    r));
 	return (EINVAL);
 }
 
 /**
  * @brief Helper function for implementing BUS_DEACTIVATE_RESOURCE().
  *
  * This simple implementation of BUS_DEACTIVATE_RESOURCE() simply calls the
  * BUS_DEACTIVATE_RESOURCE() method of the parent of @p dev.
  */
 int
 bus_generic_deactivate_resource(device_t dev, device_t child, int type,
     int rid, struct resource *r)
 {
 	/* Propagate up the bus hierarchy until someone handles it. */
 	if (dev->parent)
 		return (BUS_DEACTIVATE_RESOURCE(dev->parent, child, type, rid,
 		    r));
 	return (EINVAL);
 }
 
 /**
  * @brief Helper function for implementing BUS_MAP_RESOURCE().
  *
  * This simple implementation of BUS_MAP_RESOURCE() simply calls the
  * BUS_MAP_RESOURCE() method of the parent of @p dev.
  */
 int
 bus_generic_map_resource(device_t dev, device_t child, int type,
     struct resource *r, struct resource_map_request *args,
     struct resource_map *map)
 {
 	/* Propagate up the bus hierarchy until someone handles it. */
 	if (dev->parent)
 		return (BUS_MAP_RESOURCE(dev->parent, child, type, r, args,
 		    map));
 	return (EINVAL);
 }
 
 /**
  * @brief Helper function for implementing BUS_UNMAP_RESOURCE().
  *
  * This simple implementation of BUS_UNMAP_RESOURCE() simply calls the
  * BUS_UNMAP_RESOURCE() method of the parent of @p dev.
  */
 int
 bus_generic_unmap_resource(device_t dev, device_t child, int type,
     struct resource *r, struct resource_map *map)
 {
 	/* Propagate up the bus hierarchy until someone handles it. */
 	if (dev->parent)
 		return (BUS_UNMAP_RESOURCE(dev->parent, child, type, r, map));
 	return (EINVAL);
 }
 
 /**
  * @brief Helper function for implementing BUS_BIND_INTR().
  *
  * This simple implementation of BUS_BIND_INTR() simply calls the
  * BUS_BIND_INTR() method of the parent of @p dev.
  */
 int
 bus_generic_bind_intr(device_t dev, device_t child, struct resource *irq,
     int cpu)
 {
 	/* Propagate up the bus hierarchy until someone handles it. */
 	if (dev->parent)
 		return (BUS_BIND_INTR(dev->parent, child, irq, cpu));
 	return (EINVAL);
 }
 
 /**
  * @brief Helper function for implementing BUS_CONFIG_INTR().
  *
  * This simple implementation of BUS_CONFIG_INTR() simply calls the
  * BUS_CONFIG_INTR() method of the parent of @p dev.
  */
 int
 bus_generic_config_intr(device_t dev, int irq, enum intr_trigger trig,
     enum intr_polarity pol)
 {
 	/* Propagate up the bus hierarchy until someone handles it. */
 	if (dev->parent)
 		return (BUS_CONFIG_INTR(dev->parent, irq, trig, pol));
 	return (EINVAL);
 }
 
 /**
  * @brief Helper function for implementing BUS_DESCRIBE_INTR().
  *
  * This simple implementation of BUS_DESCRIBE_INTR() simply calls the
  * BUS_DESCRIBE_INTR() method of the parent of @p dev.
  */
 int
 bus_generic_describe_intr(device_t dev, device_t child, struct resource *irq,
     void *cookie, const char *descr)
 {
 	/* Propagate up the bus hierarchy until someone handles it. */
 	if (dev->parent)
 		return (BUS_DESCRIBE_INTR(dev->parent, child, irq, cookie,
 		    descr));
 	return (EINVAL);
 }
 
 /**
  * @brief Helper function for implementing BUS_GET_CPUS().
  *
  * This simple implementation of BUS_GET_CPUS() simply calls the
  * BUS_GET_CPUS() method of the parent of @p dev.
  */
 int
 bus_generic_get_cpus(device_t dev, device_t child, enum cpu_sets op,
     size_t setsize, cpuset_t *cpuset)
 {
 	/* Propagate up the bus hierarchy until someone handles it. */
 	if (dev->parent != NULL)
 		return (BUS_GET_CPUS(dev->parent, child, op, setsize, cpuset));
 	return (EINVAL);
 }
 
 /**
  * @brief Helper function for implementing BUS_GET_DMA_TAG().
  *
  * This simple implementation of BUS_GET_DMA_TAG() simply calls the
  * BUS_GET_DMA_TAG() method of the parent of @p dev.
  */
 bus_dma_tag_t
 bus_generic_get_dma_tag(device_t dev, device_t child)
 {
 	/* Propagate up the bus hierarchy until someone handles it. */
 	if (dev->parent != NULL)
 		return (BUS_GET_DMA_TAG(dev->parent, child));
 	return (NULL);
 }
 
 /**
  * @brief Helper function for implementing BUS_GET_BUS_TAG().
  *
  * This simple implementation of BUS_GET_BUS_TAG() simply calls the
  * BUS_GET_BUS_TAG() method of the parent of @p dev.
  */
 bus_space_tag_t
 bus_generic_get_bus_tag(device_t dev, device_t child)
 {
 	/* Propagate up the bus hierarchy until someone handles it. */
 	if (dev->parent != NULL)
 		return (BUS_GET_BUS_TAG(dev->parent, child));
 	return ((bus_space_tag_t)0);
 }
 
 /**
  * @brief Helper function for implementing BUS_GET_RESOURCE().
  *
  * This implementation of BUS_GET_RESOURCE() uses the
  * resource_list_find() function to do most of the work. It calls
  * BUS_GET_RESOURCE_LIST() to find a suitable resource list to
  * search.
  */
 int
 bus_generic_rl_get_resource(device_t dev, device_t child, int type, int rid,
     rman_res_t *startp, rman_res_t *countp)
 {
 	struct resource_list *		rl = NULL;
 	struct resource_list_entry *	rle = NULL;
 
 	rl = BUS_GET_RESOURCE_LIST(dev, child);
 	if (!rl)
 		return (EINVAL);
 
 	rle = resource_list_find(rl, type, rid);
 	if (!rle)
 		return (ENOENT);
 
 	if (startp)
 		*startp = rle->start;
 	if (countp)
 		*countp = rle->count;
 
 	return (0);
 }
 
 /**
  * @brief Helper function for implementing BUS_SET_RESOURCE().
  *
  * This implementation of BUS_SET_RESOURCE() uses the
  * resource_list_add() function to do most of the work. It calls
  * BUS_GET_RESOURCE_LIST() to find a suitable resource list to
  * edit.
  */
 int
 bus_generic_rl_set_resource(device_t dev, device_t child, int type, int rid,
     rman_res_t start, rman_res_t count)
 {
 	struct resource_list *		rl = NULL;
 
 	rl = BUS_GET_RESOURCE_LIST(dev, child);
 	if (!rl)
 		return (EINVAL);
 
 	resource_list_add(rl, type, rid, start, (start + count - 1), count);
 
 	return (0);
 }
 
 /**
  * @brief Helper function for implementing BUS_DELETE_RESOURCE().
  *
  * This implementation of BUS_DELETE_RESOURCE() uses the
  * resource_list_delete() function to do most of the work. It calls
  * BUS_GET_RESOURCE_LIST() to find a suitable resource list to
  * edit.
  */
 void
 bus_generic_rl_delete_resource(device_t dev, device_t child, int type, int rid)
 {
 	struct resource_list *		rl = NULL;
 
 	rl = BUS_GET_RESOURCE_LIST(dev, child);
 	if (!rl)
 		return;
 
 	resource_list_delete(rl, type, rid);
 
 	return;
 }
 
 /**
  * @brief Helper function for implementing BUS_RELEASE_RESOURCE().
  *
  * This implementation of BUS_RELEASE_RESOURCE() uses the
  * resource_list_release() function to do most of the work. It calls
  * BUS_GET_RESOURCE_LIST() to find a suitable resource list.
  */
 int
 bus_generic_rl_release_resource(device_t dev, device_t child, int type,
     int rid, struct resource *r)
 {
 	struct resource_list *		rl = NULL;
 
 	if (device_get_parent(child) != dev)
 		return (BUS_RELEASE_RESOURCE(device_get_parent(dev), child,
 		    type, rid, r));
 
 	rl = BUS_GET_RESOURCE_LIST(dev, child);
 	if (!rl)
 		return (EINVAL);
 
 	return (resource_list_release(rl, dev, child, type, rid, r));
 }
 
 /**
  * @brief Helper function for implementing BUS_ALLOC_RESOURCE().
  *
  * This implementation of BUS_ALLOC_RESOURCE() uses the
  * resource_list_alloc() function to do most of the work. It calls
  * BUS_GET_RESOURCE_LIST() to find a suitable resource list.
  */
 struct resource *
 bus_generic_rl_alloc_resource(device_t dev, device_t child, int type,
     int *rid, rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
 {
 	struct resource_list *		rl = NULL;
 
 	if (device_get_parent(child) != dev)
 		return (BUS_ALLOC_RESOURCE(device_get_parent(dev), child,
 		    type, rid, start, end, count, flags));
 
 	rl = BUS_GET_RESOURCE_LIST(dev, child);
 	if (!rl)
 		return (NULL);
 
 	return (resource_list_alloc(rl, dev, child, type, rid,
 	    start, end, count, flags));
 }
 
 /**
  * @brief Helper function for implementing BUS_ALLOC_RESOURCE().
  *
  * This implementation of BUS_ALLOC_RESOURCE() allocates a
  * resource from a resource manager.  It uses BUS_GET_RMAN()
  * to obtain the resource manager.
  */
 struct resource *
 bus_generic_rman_alloc_resource(device_t dev, device_t child, int type,
     int *rid, rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
 {
 	struct resource *r;
 	struct rman *rm;
 
 	rm = BUS_GET_RMAN(dev, type, flags);
 	if (rm == NULL)
 		return (NULL);
 
 	r = rman_reserve_resource(rm, start, end, count, flags & ~RF_ACTIVE,
 	    child);
 	if (r == NULL)
 		return (NULL);
 	rman_set_rid(r, *rid);
 
 	if (flags & RF_ACTIVE) {
 		if (bus_activate_resource(child, type, *rid, r) != 0) {
 			rman_release_resource(r);
 			return (NULL);
 		}
 	}
 
 	return (r);
 }
 
 /**
  * @brief Helper function for implementing BUS_ADJUST_RESOURCE().
  *
  * This implementation of BUS_ADJUST_RESOURCE() adjusts resources only
  * if they were allocated from the resource manager returned by
  * BUS_GET_RMAN().
  */
 int
 bus_generic_rman_adjust_resource(device_t dev, device_t child, int type,
     struct resource *r, rman_res_t start, rman_res_t end)
 {
 	struct rman *rm;
 
 	rm = BUS_GET_RMAN(dev, type, rman_get_flags(r));
 	if (rm == NULL)
 		return (ENXIO);
 	if (!rman_is_region_manager(r, rm))
 		return (EINVAL);
 	return (rman_adjust_resource(r, start, end));
 }
 
 /**
  * @brief Helper function for implementing BUS_RELEASE_RESOURCE().
  *
  * This implementation of BUS_RELEASE_RESOURCE() releases resources
  * allocated by bus_generic_rman_alloc_resource.
  */
 int
 bus_generic_rman_release_resource(device_t dev, device_t child, int type,
     int rid, struct resource *r)
 {
 #ifdef INVARIANTS
 	struct rman *rm;
 #endif
 	int error;
 
 #ifdef INVARIANTS
 	rm = BUS_GET_RMAN(dev, type, rman_get_flags(r));
 	KASSERT(rman_is_region_manager(r, rm),
 	    ("%s: rman %p doesn't match for resource %p", __func__, rm, r));
 #endif
 
 	if (rman_get_flags(r) & RF_ACTIVE) {
 		error = bus_deactivate_resource(child, type, rid, r);
 		if (error != 0)
 			return (error);
 	}
 	return (rman_release_resource(r));
 }
 
 /**
  * @brief Helper function for implementing BUS_ACTIVATE_RESOURCE().
  *
  * This implementation of BUS_ACTIVATE_RESOURCE() activates resources
  * allocated by bus_generic_rman_alloc_resource.
  */
 int
 bus_generic_rman_activate_resource(device_t dev, device_t child, int type,
     int rid, struct resource *r)
 {
 	struct resource_map map;
 #ifdef INVARIANTS_XXX
 	struct rman *rm;
 #endif
 	int error;
 
 #ifdef INVARIANTS_XXX
 	rm = BUS_GET_RMAN(dev, type, rman_get_flags(r));
 	KASSERT(rman_is_region_manager(r, rm),
 	    ("%s: rman %p doesn't match for resource %p", __func__, rm, r));
 #endif
 
 	error = rman_activate_resource(r);
 	if (error != 0)
 		return (error);
 
 	switch (type) {
 	case SYS_RES_IOPORT:
 	case SYS_RES_MEMORY:
 		if ((rman_get_flags(r) & RF_UNMAPPED) == 0) {
 			error = BUS_MAP_RESOURCE(dev, child, type, r, NULL, &map);
 			if (error != 0)
 				break;
 
 			rman_set_mapping(r, &map);
 		}
 		break;
 #ifdef INTRNG
 	case SYS_RES_IRQ:
 		error = intr_activate_irq(child, r);
 		break;
 #endif
 	}
 	if (error != 0)
 		rman_deactivate_resource(r);
 	return (error);
 }
 
 /**
  * @brief Helper function for implementing BUS_DEACTIVATE_RESOURCE().
  *
  * This implementation of BUS_DEACTIVATE_RESOURCE() deactivates
  * resources allocated by bus_generic_rman_alloc_resource.
  */
 int
 bus_generic_rman_deactivate_resource(device_t dev, device_t child, int type,
     int rid, struct resource *r)
 {
 	struct resource_map map;
 #ifdef INVARIANTS_XXX
 	struct rman *rm;
 #endif
 	int error;
 
 #ifdef INVARIANTS_XXX
 	rm = BUS_GET_RMAN(dev, type, rman_get_flags(r));
 	KASSERT(rman_is_region_manager(r, rm),
 	    ("%s: rman %p doesn't match for resource %p", __func__, rm, r));
 #endif
 
 	error = rman_deactivate_resource(r);
 	if (error != 0)
 		return (error);
 
 	switch (type) {
 	case SYS_RES_IOPORT:
 	case SYS_RES_MEMORY:
 		if ((rman_get_flags(r) & RF_UNMAPPED) == 0) {
 			rman_get_mapping(r, &map);
 			BUS_UNMAP_RESOURCE(dev, child, type, r, &map);
 		}
 		break;
 #ifdef INTRNG
 	case SYS_RES_IRQ:
 		intr_deactivate_irq(child, r);
 		break;
 #endif
 	}
 	return (0);
 }
 
 /**
  * @brief Helper function for implementing BUS_CHILD_PRESENT().
  *
  * This simple implementation of BUS_CHILD_PRESENT() simply calls the
  * BUS_CHILD_PRESENT() method of the parent of @p dev.
  */
 int
 bus_generic_child_present(device_t dev, device_t child)
 {
 	return (BUS_CHILD_PRESENT(device_get_parent(dev), dev));
 }
 
 /**
  * @brief Helper function for implementing BUS_GET_DOMAIN().
  *
  * This simple implementation of BUS_GET_DOMAIN() calls the
  * BUS_GET_DOMAIN() method of the parent of @p dev.  If @p dev
  * does not have a parent, the function fails with ENOENT.
  */
 int
 bus_generic_get_domain(device_t dev, device_t child, int *domain)
 {
 	if (dev->parent)
 		return (BUS_GET_DOMAIN(dev->parent, dev, domain));
 
 	return (ENOENT);
 }
 
 /**
  * @brief Helper function to implement normal BUS_GET_DEVICE_PATH()
  *
  * This function knows how to (a) pass the request up the tree if there's
  * a parent and (b) Knows how to supply a FreeBSD locator.
  *
  * @param bus		bus in the walk up the tree
  * @param child		leaf node to print information about
  * @param locator	BUS_LOCATOR_xxx string for locator
  * @param sb		Buffer to print information into
  */
 int
 bus_generic_get_device_path(device_t bus, device_t child, const char *locator,
     struct sbuf *sb)
 {
 	int rv = 0;
 	device_t parent;
 
 	/*
 	 * We don't recurse on ACPI since either we know the handle for the
 	 * device or we don't. And if we're in the generic routine, we don't
 	 * have a ACPI override. All other locators build up a path by having
 	 * their parents create a path and then adding the path element for this
 	 * node. That's why we recurse with parent, bus rather than the typical
 	 * parent, child: each spot in the tree is independent of what our child
 	 * will do with this path.
 	 */
 	parent = device_get_parent(bus);
 	if (parent != NULL && strcmp(locator, BUS_LOCATOR_ACPI) != 0) {
 		rv = BUS_GET_DEVICE_PATH(parent, bus, locator, sb);
 	}
 	if (strcmp(locator, BUS_LOCATOR_FREEBSD) == 0) {
 		if (rv == 0) {
 			sbuf_printf(sb, "/%s", device_get_nameunit(child));
 		}
 		return (rv);
 	}
 	/*
 	 * Don't know what to do. So assume we do nothing. Not sure that's
 	 * the right thing, but keeps us from having a big list here.
 	 */
 	return (0);
 }
 
 
 /**
  * @brief Helper function for implementing BUS_RESCAN().
  *
  * This null implementation of BUS_RESCAN() always fails to indicate
  * the bus does not support rescanning.
  */
 int
 bus_null_rescan(device_t dev)
 {
 	return (ENODEV);
 }
 
 /*
  * Some convenience functions to make it easier for drivers to use the
  * resource-management functions.  All these really do is hide the
  * indirection through the parent's method table, making for slightly
  * less-wordy code.  In the future, it might make sense for this code
  * to maintain some sort of a list of resources allocated by each device.
  */
 
 int
 bus_alloc_resources(device_t dev, struct resource_spec *rs,
     struct resource **res)
 {
 	int i;
 
 	for (i = 0; rs[i].type != -1; i++)
 		res[i] = NULL;
 	for (i = 0; rs[i].type != -1; i++) {
 		res[i] = bus_alloc_resource_any(dev,
 		    rs[i].type, &rs[i].rid, rs[i].flags);
 		if (res[i] == NULL && !(rs[i].flags & RF_OPTIONAL)) {
 			bus_release_resources(dev, rs, res);
 			return (ENXIO);
 		}
 	}
 	return (0);
 }
 
 void
 bus_release_resources(device_t dev, const struct resource_spec *rs,
     struct resource **res)
 {
 	int i;
 
 	for (i = 0; rs[i].type != -1; i++)
 		if (res[i] != NULL) {
 			bus_release_resource(
 			    dev, rs[i].type, rs[i].rid, res[i]);
 			res[i] = NULL;
 		}
 }
 
 /**
  * @brief Wrapper function for BUS_ALLOC_RESOURCE().
  *
  * This function simply calls the BUS_ALLOC_RESOURCE() method of the
  * parent of @p dev.
  */
 struct resource *
 bus_alloc_resource(device_t dev, int type, int *rid, rman_res_t start,
     rman_res_t end, rman_res_t count, u_int flags)
 {
 	struct resource *res;
 
 	if (dev->parent == NULL)
 		return (NULL);
 	res = BUS_ALLOC_RESOURCE(dev->parent, dev, type, rid, start, end,
 	    count, flags);
 	return (res);
 }
 
 /**
  * @brief Wrapper function for BUS_ADJUST_RESOURCE().
  *
  * This function simply calls the BUS_ADJUST_RESOURCE() method of the
  * parent of @p dev.
  */
 int
 bus_adjust_resource(device_t dev, int type, struct resource *r, rman_res_t start,
     rman_res_t end)
 {
 	if (dev->parent == NULL)
 		return (EINVAL);
 	return (BUS_ADJUST_RESOURCE(dev->parent, dev, type, r, start, end));
 }
 
 /**
  * @brief Wrapper function for BUS_TRANSLATE_RESOURCE().
  *
  * This function simply calls the BUS_TRANSLATE_RESOURCE() method of the
  * parent of @p dev.
  */
 int
 bus_translate_resource(device_t dev, int type, rman_res_t start,
     rman_res_t *newstart)
 {
 	if (dev->parent == NULL)
 		return (EINVAL);
 	return (BUS_TRANSLATE_RESOURCE(dev->parent, type, start, newstart));
 }
 
 /**
  * @brief Wrapper function for BUS_ACTIVATE_RESOURCE().
  *
  * This function simply calls the BUS_ACTIVATE_RESOURCE() method of the
  * parent of @p dev.
  */
 int
 bus_activate_resource(device_t dev, int type, int rid, struct resource *r)
 {
 	if (dev->parent == NULL)
 		return (EINVAL);
 	return (BUS_ACTIVATE_RESOURCE(dev->parent, dev, type, rid, r));
 }
 
 /**
  * @brief Wrapper function for BUS_DEACTIVATE_RESOURCE().
  *
  * This function simply calls the BUS_DEACTIVATE_RESOURCE() method of the
  * parent of @p dev.
  */
 int
 bus_deactivate_resource(device_t dev, int type, int rid, struct resource *r)
 {
 	if (dev->parent == NULL)
 		return (EINVAL);
 	return (BUS_DEACTIVATE_RESOURCE(dev->parent, dev, type, rid, r));
 }
 
 /**
  * @brief Wrapper function for BUS_MAP_RESOURCE().
  *
  * This function simply calls the BUS_MAP_RESOURCE() method of the
  * parent of @p dev.
  */
 int
 bus_map_resource(device_t dev, int type, struct resource *r,
     struct resource_map_request *args, struct resource_map *map)
 {
 	if (dev->parent == NULL)
 		return (EINVAL);
 	return (BUS_MAP_RESOURCE(dev->parent, dev, type, r, args, map));
 }
 
 /**
  * @brief Wrapper function for BUS_UNMAP_RESOURCE().
  *
  * This function simply calls the BUS_UNMAP_RESOURCE() method of the
  * parent of @p dev.
  */
 int
 bus_unmap_resource(device_t dev, int type, struct resource *r,
     struct resource_map *map)
 {
 	if (dev->parent == NULL)
 		return (EINVAL);
 	return (BUS_UNMAP_RESOURCE(dev->parent, dev, type, r, map));
 }
 
 /**
  * @brief Wrapper function for BUS_RELEASE_RESOURCE().
  *
  * This function simply calls the BUS_RELEASE_RESOURCE() method of the
  * parent of @p dev.
  */
 int
 bus_release_resource(device_t dev, int type, int rid, struct resource *r)
 {
 	int rv;
 
 	if (dev->parent == NULL)
 		return (EINVAL);
 	rv = BUS_RELEASE_RESOURCE(dev->parent, dev, type, rid, r);
 	return (rv);
 }
 
 /**
  * @brief Wrapper function for BUS_SETUP_INTR().
  *
  * This function simply calls the BUS_SETUP_INTR() method of the
  * parent of @p dev.
  */
 int
 bus_setup_intr(device_t dev, struct resource *r, int flags,
     driver_filter_t filter, driver_intr_t handler, void *arg, void **cookiep)
 {
 	int error;
 
 	if (dev->parent == NULL)
 		return (EINVAL);
 	error = BUS_SETUP_INTR(dev->parent, dev, r, flags, filter, handler,
 	    arg, cookiep);
 	if (error != 0)
 		return (error);
 	if (handler != NULL && !(flags & INTR_MPSAFE))
 		device_printf(dev, "[GIANT-LOCKED]\n");
 	return (0);
 }
 
 /**
  * @brief Wrapper function for BUS_TEARDOWN_INTR().
  *
  * This function simply calls the BUS_TEARDOWN_INTR() method of the
  * parent of @p dev.
  */
 int
 bus_teardown_intr(device_t dev, struct resource *r, void *cookie)
 {
 	if (dev->parent == NULL)
 		return (EINVAL);
 	return (BUS_TEARDOWN_INTR(dev->parent, dev, r, cookie));
 }
 
 /**
  * @brief Wrapper function for BUS_SUSPEND_INTR().
  *
  * This function simply calls the BUS_SUSPEND_INTR() method of the
  * parent of @p dev.
  */
 int
 bus_suspend_intr(device_t dev, struct resource *r)
 {
 	if (dev->parent == NULL)
 		return (EINVAL);
 	return (BUS_SUSPEND_INTR(dev->parent, dev, r));
 }
 
 /**
  * @brief Wrapper function for BUS_RESUME_INTR().
  *
  * This function simply calls the BUS_RESUME_INTR() method of the
  * parent of @p dev.
  */
 int
 bus_resume_intr(device_t dev, struct resource *r)
 {
 	if (dev->parent == NULL)
 		return (EINVAL);
 	return (BUS_RESUME_INTR(dev->parent, dev, r));
 }
 
 /**
  * @brief Wrapper function for BUS_BIND_INTR().
  *
  * This function simply calls the BUS_BIND_INTR() method of the
  * parent of @p dev.
  */
 int
 bus_bind_intr(device_t dev, struct resource *r, int cpu)
 {
 	if (dev->parent == NULL)
 		return (EINVAL);
 	return (BUS_BIND_INTR(dev->parent, dev, r, cpu));
 }
 
 /**
  * @brief Wrapper function for BUS_DESCRIBE_INTR().
  *
  * This function first formats the requested description into a
  * temporary buffer and then calls the BUS_DESCRIBE_INTR() method of
  * the parent of @p dev.
  */
 int
 bus_describe_intr(device_t dev, struct resource *irq, void *cookie,
     const char *fmt, ...)
 {
 	va_list ap;
 	char descr[MAXCOMLEN + 1];
 
 	if (dev->parent == NULL)
 		return (EINVAL);
 	va_start(ap, fmt);
 	vsnprintf(descr, sizeof(descr), fmt, ap);
 	va_end(ap);
 	return (BUS_DESCRIBE_INTR(dev->parent, dev, irq, cookie, descr));
 }
 
 /**
  * @brief Wrapper function for BUS_SET_RESOURCE().
  *
  * This function simply calls the BUS_SET_RESOURCE() method of the
  * parent of @p dev.
  */
 int
 bus_set_resource(device_t dev, int type, int rid,
     rman_res_t start, rman_res_t count)
 {
 	return (BUS_SET_RESOURCE(device_get_parent(dev), dev, type, rid,
 	    start, count));
 }
 
 /**
  * @brief Wrapper function for BUS_GET_RESOURCE().
  *
  * This function simply calls the BUS_GET_RESOURCE() method of the
  * parent of @p dev.
  */
 int
 bus_get_resource(device_t dev, int type, int rid,
     rman_res_t *startp, rman_res_t *countp)
 {
 	return (BUS_GET_RESOURCE(device_get_parent(dev), dev, type, rid,
 	    startp, countp));
 }
 
 /**
  * @brief Wrapper function for BUS_GET_RESOURCE().
  *
  * This function simply calls the BUS_GET_RESOURCE() method of the
  * parent of @p dev and returns the start value.
  */
 rman_res_t
 bus_get_resource_start(device_t dev, int type, int rid)
 {
 	rman_res_t start;
 	rman_res_t count;
 	int error;
 
 	error = BUS_GET_RESOURCE(device_get_parent(dev), dev, type, rid,
 	    &start, &count);
 	if (error)
 		return (0);
 	return (start);
 }
 
 /**
  * @brief Wrapper function for BUS_GET_RESOURCE().
  *
  * This function simply calls the BUS_GET_RESOURCE() method of the
  * parent of @p dev and returns the count value.
  */
 rman_res_t
 bus_get_resource_count(device_t dev, int type, int rid)
 {
 	rman_res_t start;
 	rman_res_t count;
 	int error;
 
 	error = BUS_GET_RESOURCE(device_get_parent(dev), dev, type, rid,
 	    &start, &count);
 	if (error)
 		return (0);
 	return (count);
 }
 
 /**
  * @brief Wrapper function for BUS_DELETE_RESOURCE().
  *
  * This function simply calls the BUS_DELETE_RESOURCE() method of the
  * parent of @p dev.
  */
 void
 bus_delete_resource(device_t dev, int type, int rid)
 {
 	BUS_DELETE_RESOURCE(device_get_parent(dev), dev, type, rid);
 }
 
 /**
  * @brief Wrapper function for BUS_CHILD_PRESENT().
  *
  * This function simply calls the BUS_CHILD_PRESENT() method of the
  * parent of @p dev.
  */
 int
 bus_child_present(device_t child)
 {
 	return (BUS_CHILD_PRESENT(device_get_parent(child), child));
 }
 
 /**
  * @brief Wrapper function for BUS_CHILD_PNPINFO().
  *
  * This function simply calls the BUS_CHILD_PNPINFO() method of the parent of @p
  * dev.
  */
 int
 bus_child_pnpinfo(device_t child, struct sbuf *sb)
 {
 	device_t parent;
 
 	parent = device_get_parent(child);
 	if (parent == NULL)
 		return (0);
 	return (BUS_CHILD_PNPINFO(parent, child, sb));
 }
 
 /**
  * @brief Generic implementation that does nothing for bus_child_pnpinfo
  *
  * This function has the right signature and returns 0 since the sbuf is passed
  * to us to append to.
  */
 int
 bus_generic_child_pnpinfo(device_t dev, device_t child, struct sbuf *sb)
 {
 	return (0);
 }
 
 /**
  * @brief Wrapper function for BUS_CHILD_LOCATION().
  *
  * This function simply calls the BUS_CHILD_LOCATION() method of the parent of
  * @p dev.
  */
 int
 bus_child_location(device_t child, struct sbuf *sb)
 {
 	device_t parent;
 
 	parent = device_get_parent(child);
 	if (parent == NULL)
 		return (0);
 	return (BUS_CHILD_LOCATION(parent, child, sb));
 }
 
 /**
  * @brief Generic implementation that does nothing for bus_child_location
  *
  * This function has the right signature and returns 0 since the sbuf is passed
  * to us to append to.
  */
 int
 bus_generic_child_location(device_t dev, device_t child, struct sbuf *sb)
 {
 	return (0);
 }
 
 /**
  * @brief Wrapper function for BUS_GET_CPUS().
  *
  * This function simply calls the BUS_GET_CPUS() method of the
  * parent of @p dev.
  */
 int
 bus_get_cpus(device_t dev, enum cpu_sets op, size_t setsize, cpuset_t *cpuset)
 {
 	device_t parent;
 
 	parent = device_get_parent(dev);
 	if (parent == NULL)
 		return (EINVAL);
 	return (BUS_GET_CPUS(parent, dev, op, setsize, cpuset));
 }
 
 /**
  * @brief Wrapper function for BUS_GET_DMA_TAG().
  *
  * This function simply calls the BUS_GET_DMA_TAG() method of the
  * parent of @p dev.
  */
 bus_dma_tag_t
 bus_get_dma_tag(device_t dev)
 {
 	device_t parent;
 
 	parent = device_get_parent(dev);
 	if (parent == NULL)
 		return (NULL);
 	return (BUS_GET_DMA_TAG(parent, dev));
 }
 
 /**
  * @brief Wrapper function for BUS_GET_BUS_TAG().
  *
  * This function simply calls the BUS_GET_BUS_TAG() method of the
  * parent of @p dev.
  */
 bus_space_tag_t
 bus_get_bus_tag(device_t dev)
 {
 	device_t parent;
 
 	parent = device_get_parent(dev);
 	if (parent == NULL)
 		return ((bus_space_tag_t)0);
 	return (BUS_GET_BUS_TAG(parent, dev));
 }
 
 /**
  * @brief Wrapper function for BUS_GET_DOMAIN().
  *
  * This function simply calls the BUS_GET_DOMAIN() method of the
  * parent of @p dev.
  */
 int
 bus_get_domain(device_t dev, int *domain)
 {
 	return (BUS_GET_DOMAIN(device_get_parent(dev), dev, domain));
 }
 
 /* Resume all devices and then notify userland that we're up again. */
 static int
 root_resume(device_t dev)
 {
 	int error;
 
 	error = bus_generic_resume(dev);
 	if (error == 0) {
 		devctl_notify("kernel", "power", "resume", NULL);
 	}
 	return (error);
 }
 
 static int
 root_print_child(device_t dev, device_t child)
 {
 	int	retval = 0;
 
 	retval += bus_print_child_header(dev, child);
 	retval += printf("\n");
 
 	return (retval);
 }
 
 static int
 root_setup_intr(device_t dev, device_t child, struct resource *irq, int flags,
     driver_filter_t *filter, driver_intr_t *intr, void *arg, void **cookiep)
 {
 	/*
 	 * If an interrupt mapping gets to here something bad has happened.
 	 */
 	panic("root_setup_intr");
 }
 
 /*
  * If we get here, assume that the device is permanent and really is
  * present in the system.  Removable bus drivers are expected to intercept
  * this call long before it gets here.  We return -1 so that drivers that
  * really care can check vs -1 or some ERRNO returned higher in the food
  * chain.
  */
 static int
 root_child_present(device_t dev, device_t child)
 {
 	return (-1);
 }
 
 static int
 root_get_cpus(device_t dev, device_t child, enum cpu_sets op, size_t setsize,
     cpuset_t *cpuset)
 {
 	switch (op) {
 	case INTR_CPUS:
 		/* Default to returning the set of all CPUs. */
 		if (setsize != sizeof(cpuset_t))
 			return (EINVAL);
 		*cpuset = all_cpus;
 		return (0);
 	default:
 		return (EINVAL);
 	}
 }
 
 static kobj_method_t root_methods[] = {
 	/* Device interface */
 	KOBJMETHOD(device_shutdown,	bus_generic_shutdown),
 	KOBJMETHOD(device_suspend,	bus_generic_suspend),
 	KOBJMETHOD(device_resume,	root_resume),
 
 	/* Bus interface */
 	KOBJMETHOD(bus_print_child,	root_print_child),
 	KOBJMETHOD(bus_read_ivar,	bus_generic_read_ivar),
 	KOBJMETHOD(bus_write_ivar,	bus_generic_write_ivar),
 	KOBJMETHOD(bus_setup_intr,	root_setup_intr),
 	KOBJMETHOD(bus_child_present,	root_child_present),
 	KOBJMETHOD(bus_get_cpus,	root_get_cpus),
 
 	KOBJMETHOD_END
 };
 
 static driver_t root_driver = {
 	"root",
 	root_methods,
 	1,			/* no softc */
 };
 
 device_t	root_bus;
 devclass_t	root_devclass;
 
 static int
 root_bus_module_handler(module_t mod, int what, void* arg)
 {
 	switch (what) {
 	case MOD_LOAD:
 		TAILQ_INIT(&bus_data_devices);
 		kobj_class_compile((kobj_class_t) &root_driver);
 		root_bus = make_device(NULL, "root", 0);
 		root_bus->desc = "System root bus";
 		kobj_init((kobj_t) root_bus, (kobj_class_t) &root_driver);
 		root_bus->driver = &root_driver;
 		root_bus->state = DS_ATTACHED;
 		root_devclass = devclass_find_internal("root", NULL, FALSE);
 		devctl2_init();
 		return (0);
 
 	case MOD_SHUTDOWN:
 		device_shutdown(root_bus);
 		return (0);
 	default:
 		return (EOPNOTSUPP);
 	}
 
 	return (0);
 }
 
 static moduledata_t root_bus_mod = {
 	"rootbus",
 	root_bus_module_handler,
 	NULL
 };
 DECLARE_MODULE(rootbus, root_bus_mod, SI_SUB_DRIVERS, SI_ORDER_FIRST);
 
 /**
  * @brief Automatically configure devices
  *
  * This function begins the autoconfiguration process by calling
  * device_probe_and_attach() for each child of the @c root0 device.
  */
 void
 root_bus_configure(void)
 {
 	PDEBUG(("."));
 
 	/* Eventually this will be split up, but this is sufficient for now. */
 	bus_set_pass(BUS_PASS_DEFAULT);
 }
 
 /**
  * @brief Module handler for registering device drivers
  *
  * This module handler is used to automatically register device
  * drivers when modules are loaded. If @p what is MOD_LOAD, it calls
  * devclass_add_driver() for the driver described by the
  * driver_module_data structure pointed to by @p arg
  */
 int
 driver_module_handler(module_t mod, int what, void *arg)
 {
 	struct driver_module_data *dmd;
 	devclass_t bus_devclass;
 	kobj_class_t driver;
 	int error, pass;
 
 	dmd = (struct driver_module_data *)arg;
 	bus_devclass = devclass_find_internal(dmd->dmd_busname, NULL, TRUE);
 	error = 0;
 
 	switch (what) {
 	case MOD_LOAD:
 		if (dmd->dmd_chainevh)
 			error = dmd->dmd_chainevh(mod,what,dmd->dmd_chainarg);
 
 		pass = dmd->dmd_pass;
 		driver = dmd->dmd_driver;
 		PDEBUG(("Loading module: driver %s on bus %s (pass %d)",
 		    DRIVERNAME(driver), dmd->dmd_busname, pass));
 		error = devclass_add_driver(bus_devclass, driver, pass,
 		    dmd->dmd_devclass);
 		break;
 
 	case MOD_UNLOAD:
 		PDEBUG(("Unloading module: driver %s from bus %s",
 		    DRIVERNAME(dmd->dmd_driver),
 		    dmd->dmd_busname));
 		error = devclass_delete_driver(bus_devclass,
 		    dmd->dmd_driver);
 
 		if (!error && dmd->dmd_chainevh)
 			error = dmd->dmd_chainevh(mod,what,dmd->dmd_chainarg);
 		break;
 	case MOD_QUIESCE:
 		PDEBUG(("Quiesce module: driver %s from bus %s",
 		    DRIVERNAME(dmd->dmd_driver),
 		    dmd->dmd_busname));
 		error = devclass_quiesce_driver(bus_devclass,
 		    dmd->dmd_driver);
 
 		if (!error && dmd->dmd_chainevh)
 			error = dmd->dmd_chainevh(mod,what,dmd->dmd_chainarg);
 		break;
 	default:
 		error = EOPNOTSUPP;
 		break;
 	}
 
 	return (error);
 }
 
 /**
  * @brief Enumerate all hinted devices for this bus.
  *
  * Walks through the hints for this bus and calls the bus_hinted_child
  * routine for each one it fines.  It searches first for the specific
  * bus that's being probed for hinted children (eg isa0), and then for
  * generic children (eg isa).
  *
  * @param	dev	bus device to enumerate
  */
 void
 bus_enumerate_hinted_children(device_t bus)
 {
 	int i;
 	const char *dname, *busname;
 	int dunit;
 
 	/*
 	 * enumerate all devices on the specific bus
 	 */
 	busname = device_get_nameunit(bus);
 	i = 0;
 	while (resource_find_match(&i, &dname, &dunit, "at", busname) == 0)
 		BUS_HINTED_CHILD(bus, dname, dunit);
 
 	/*
 	 * and all the generic ones.
 	 */
 	busname = device_get_name(bus);
 	i = 0;
 	while (resource_find_match(&i, &dname, &dunit, "at", busname) == 0)
 		BUS_HINTED_CHILD(bus, dname, dunit);
 }
 
 #ifdef BUS_DEBUG
 
 /* the _short versions avoid iteration by not calling anything that prints
  * more than oneliners. I love oneliners.
  */
 
 static void
 print_device_short(device_t dev, int indent)
 {
 	if (!dev)
 		return;
 
 	indentprintf(("device %d: <%s> %sparent,%schildren,%s%s%s%s%s,%sivars,%ssoftc,busy=%d\n",
 	    dev->unit, dev->desc,
 	    (dev->parent? "":"no "),
 	    (TAILQ_EMPTY(&dev->children)? "no ":""),
 	    (dev->flags&DF_ENABLED? "enabled,":"disabled,"),
 	    (dev->flags&DF_FIXEDCLASS? "fixed,":""),
 	    (dev->flags&DF_WILDCARD? "wildcard,":""),
 	    (dev->flags&DF_DESCMALLOCED? "descmalloced,":""),
 	    (dev->flags&DF_SUSPENDED? "suspended,":""),
 	    (dev->ivars? "":"no "),
 	    (dev->softc? "":"no "),
 	    dev->busy));
 }
 
 static void
 print_device(device_t dev, int indent)
 {
 	if (!dev)
 		return;
 
 	print_device_short(dev, indent);
 
 	indentprintf(("Parent:\n"));
 	print_device_short(dev->parent, indent+1);
 	indentprintf(("Driver:\n"));
 	print_driver_short(dev->driver, indent+1);
 	indentprintf(("Devclass:\n"));
 	print_devclass_short(dev->devclass, indent+1);
 }
 
 void
 print_device_tree_short(device_t dev, int indent)
 /* print the device and all its children (indented) */
 {
 	device_t child;
 
 	if (!dev)
 		return;
 
 	print_device_short(dev, indent);
 
 	TAILQ_FOREACH(child, &dev->children, link) {
 		print_device_tree_short(child, indent+1);
 	}
 }
 
 void
 print_device_tree(device_t dev, int indent)
 /* print the device and all its children (indented) */
 {
 	device_t child;
 
 	if (!dev)
 		return;
 
 	print_device(dev, indent);
 
 	TAILQ_FOREACH(child, &dev->children, link) {
 		print_device_tree(child, indent+1);
 	}
 }
 
 static void
 print_driver_short(driver_t *driver, int indent)
 {
 	if (!driver)
 		return;
 
 	indentprintf(("driver %s: softc size = %zd\n",
 	    driver->name, driver->size));
 }
 
 static void
 print_driver(driver_t *driver, int indent)
 {
 	if (!driver)
 		return;
 
 	print_driver_short(driver, indent);
 }
 
 static void
 print_driver_list(driver_list_t drivers, int indent)
 {
 	driverlink_t driver;
 
 	TAILQ_FOREACH(driver, &drivers, link) {
 		print_driver(driver->driver, indent);
 	}
 }
 
 static void
 print_devclass_short(devclass_t dc, int indent)
 {
 	if ( !dc )
 		return;
 
 	indentprintf(("devclass %s: max units = %d\n", dc->name, dc->maxunit));
 }
 
 static void
 print_devclass(devclass_t dc, int indent)
 {
 	int i;
 
 	if ( !dc )
 		return;
 
 	print_devclass_short(dc, indent);
 	indentprintf(("Drivers:\n"));
 	print_driver_list(dc->drivers, indent+1);
 
 	indentprintf(("Devices:\n"));
 	for (i = 0; i < dc->maxunit; i++)
 		if (dc->devices[i])
 			print_device(dc->devices[i], indent+1);
 }
 
 void
 print_devclass_list_short(void)
 {
 	devclass_t dc;
 
 	printf("Short listing of devclasses, drivers & devices:\n");
 	TAILQ_FOREACH(dc, &devclasses, link) {
 		print_devclass_short(dc, 0);
 	}
 }
 
 void
 print_devclass_list(void)
 {
 	devclass_t dc;
 
 	printf("Full listing of devclasses, drivers & devices:\n");
 	TAILQ_FOREACH(dc, &devclasses, link) {
 		print_devclass(dc, 0);
 	}
 }
 
 #endif
 
 /*
  * User-space access to the device tree.
  *
  * We implement a small set of nodes:
  *
  * hw.bus			Single integer read method to obtain the
  *				current generation count.
  * hw.bus.devices		Reads the entire device tree in flat space.
  * hw.bus.rman			Resource manager interface
  *
  * We might like to add the ability to scan devclasses and/or drivers to
  * determine what else is currently loaded/available.
  */
 
 static int
 sysctl_bus_info(SYSCTL_HANDLER_ARGS)
 {
 	struct u_businfo	ubus;
 
 	ubus.ub_version = BUS_USER_VERSION;
 	ubus.ub_generation = bus_data_generation;
 
 	return (SYSCTL_OUT(req, &ubus, sizeof(ubus)));
 }
 SYSCTL_PROC(_hw_bus, OID_AUTO, info, CTLTYPE_STRUCT | CTLFLAG_RD |
     CTLFLAG_MPSAFE, NULL, 0, sysctl_bus_info, "S,u_businfo",
     "bus-related data");
 
 static int
 sysctl_devices(SYSCTL_HANDLER_ARGS)
 {
 	struct sbuf		sb;
 	int			*name = (int *)arg1;
 	u_int			namelen = arg2;
 	int			index;
 	device_t		dev;
 	struct u_device		*udev;
 	int			error;
 
 	if (namelen != 2)
 		return (EINVAL);
 
 	if (bus_data_generation_check(name[0]))
 		return (EINVAL);
 
 	index = name[1];
 
 	/*
 	 * Scan the list of devices, looking for the requested index.
 	 */
 	TAILQ_FOREACH(dev, &bus_data_devices, devlink) {
 		if (index-- == 0)
 			break;
 	}
 	if (dev == NULL)
 		return (ENOENT);
 
 	/*
 	 * Populate the return item, careful not to overflow the buffer.
 	 */
 	udev = malloc(sizeof(*udev), M_BUS, M_WAITOK | M_ZERO);
 	udev->dv_handle = (uintptr_t)dev;
 	udev->dv_parent = (uintptr_t)dev->parent;
 	udev->dv_devflags = dev->devflags;
 	udev->dv_flags = dev->flags;
 	udev->dv_state = dev->state;
 	sbuf_new(&sb, udev->dv_fields, sizeof(udev->dv_fields), SBUF_FIXEDLEN);
 	if (dev->nameunit != NULL)
 		sbuf_cat(&sb, dev->nameunit);
 	sbuf_putc(&sb, '\0');
 	if (dev->desc != NULL)
 		sbuf_cat(&sb, dev->desc);
 	sbuf_putc(&sb, '\0');
 	if (dev->driver != NULL)
 		sbuf_cat(&sb, dev->driver->name);
 	sbuf_putc(&sb, '\0');
 	bus_child_pnpinfo(dev, &sb);
 	sbuf_putc(&sb, '\0');
 	bus_child_location(dev, &sb);
 	sbuf_putc(&sb, '\0');
 	error = sbuf_finish(&sb);
 	if (error == 0)
 		error = SYSCTL_OUT(req, udev, sizeof(*udev));
 	sbuf_delete(&sb);
 	free(udev, M_BUS);
 	return (error);
 }
 
 SYSCTL_NODE(_hw_bus, OID_AUTO, devices,
     CTLFLAG_RD | CTLFLAG_NEEDGIANT, sysctl_devices,
     "system device tree");
 
 int
 bus_data_generation_check(int generation)
 {
 	if (generation != bus_data_generation)
 		return (1);
 
 	/* XXX generate optimised lists here? */
 	return (0);
 }
 
 void
 bus_data_generation_update(void)
 {
 	atomic_add_int(&bus_data_generation, 1);
 }
 
 int
 bus_free_resource(device_t dev, int type, struct resource *r)
 {
 	if (r == NULL)
 		return (0);
 	return (bus_release_resource(dev, type, rman_get_rid(r), r));
 }
 
 device_t
 device_lookup_by_name(const char *name)
 {
 	device_t dev;
 
 	TAILQ_FOREACH(dev, &bus_data_devices, devlink) {
 		if (dev->nameunit != NULL && strcmp(dev->nameunit, name) == 0)
 			return (dev);
 	}
 	return (NULL);
 }
 
 /*
  * /dev/devctl2 implementation.  The existing /dev/devctl device has
  * implicit semantics on open, so it could not be reused for this.
  * Another option would be to call this /dev/bus?
  */
 static int
 find_device(struct devreq *req, device_t *devp)
 {
 	device_t dev;
 
 	/*
 	 * First, ensure that the name is nul terminated.
 	 */
 	if (memchr(req->dr_name, '\0', sizeof(req->dr_name)) == NULL)
 		return (EINVAL);
 
 	/*
 	 * Second, try to find an attached device whose name matches
 	 * 'name'.
 	 */
 	dev = device_lookup_by_name(req->dr_name);
 	if (dev != NULL) {
 		*devp = dev;
 		return (0);
 	}
 
 	/* Finally, give device enumerators a chance. */
 	dev = NULL;
 	EVENTHANDLER_DIRECT_INVOKE(dev_lookup, req->dr_name, &dev);
 	if (dev == NULL)
 		return (ENOENT);
 	*devp = dev;
 	return (0);
 }
 
 static bool
 driver_exists(device_t bus, const char *driver)
 {
 	devclass_t dc;
 
 	for (dc = bus->devclass; dc != NULL; dc = dc->parent) {
 		if (devclass_find_driver_internal(dc, driver) != NULL)
 			return (true);
 	}
 	return (false);
 }
 
 static void
 device_gen_nomatch(device_t dev)
 {
 	device_t child;
 
 	if (dev->flags & DF_NEEDNOMATCH &&
 	    dev->state == DS_NOTPRESENT) {
 		device_handle_nomatch(dev);
 	}
 	dev->flags &= ~DF_NEEDNOMATCH;
 	TAILQ_FOREACH(child, &dev->children, link) {
 		device_gen_nomatch(child);
 	}
 }
 
 static void
 device_do_deferred_actions(void)
 {
 	devclass_t dc;
 	driverlink_t dl;
 
 	/*
 	 * Walk through the devclasses to find all the drivers we've tagged as
 	 * deferred during the freeze and call the driver added routines. They
 	 * have already been added to the lists in the background, so the driver
 	 * added routines that trigger a probe will have all the right bidders
 	 * for the probe auction.
 	 */
 	TAILQ_FOREACH(dc, &devclasses, link) {
 		TAILQ_FOREACH(dl, &dc->drivers, link) {
 			if (dl->flags & DL_DEFERRED_PROBE) {
 				devclass_driver_added(dc, dl->driver);
 				dl->flags &= ~DL_DEFERRED_PROBE;
 			}
 		}
 	}
 
 	/*
 	 * We also defer no-match events during a freeze. Walk the tree and
 	 * generate all the pent-up events that are still relevant.
 	 */
 	device_gen_nomatch(root_bus);
 	bus_data_generation_update();
 }
 
 static int
 device_get_path(device_t dev, const char *locator, struct sbuf *sb)
 {
 	device_t parent;
 	int error;
 
 	KASSERT(sb != NULL, ("sb is NULL"));
 	parent = device_get_parent(dev);
 	if (parent == NULL) {
 		error = sbuf_printf(sb, "/");
 	} else {
 		error = BUS_GET_DEVICE_PATH(parent, dev, locator, sb);
 		if (error == 0) {
 			error = sbuf_error(sb);
 			if (error == 0 && sbuf_len(sb) <= 1)
 				error = EIO;
 		}
 	}
 	sbuf_finish(sb);
 	return (error);
 }
 
 static int
 devctl2_ioctl(struct cdev *cdev, u_long cmd, caddr_t data, int fflag,
     struct thread *td)
 {
 	struct devreq *req;
 	device_t dev;
 	int error, old;
 
 	/* Locate the device to control. */
 	bus_topo_lock();
 	req = (struct devreq *)data;
 	switch (cmd) {
 	case DEV_ATTACH:
 	case DEV_DETACH:
 	case DEV_ENABLE:
 	case DEV_DISABLE:
 	case DEV_SUSPEND:
 	case DEV_RESUME:
 	case DEV_SET_DRIVER:
 	case DEV_CLEAR_DRIVER:
 	case DEV_RESCAN:
 	case DEV_DELETE:
 	case DEV_RESET:
 		error = priv_check(td, PRIV_DRIVER);
 		if (error == 0)
 			error = find_device(req, &dev);
 		break;
 	case DEV_FREEZE:
 	case DEV_THAW:
 		error = priv_check(td, PRIV_DRIVER);
 		break;
 	case DEV_GET_PATH:
 		error = find_device(req, &dev);
 		break;
 	default:
 		error = ENOTTY;
 		break;
 	}
 	if (error) {
 		bus_topo_unlock();
 		return (error);
 	}
 
 	/* Perform the requested operation. */
 	switch (cmd) {
 	case DEV_ATTACH:
 		if (device_is_attached(dev))
 			error = EBUSY;
 		else if (!device_is_enabled(dev))
 			error = ENXIO;
 		else
 			error = device_probe_and_attach(dev);
 		break;
 	case DEV_DETACH:
 		if (!device_is_attached(dev)) {
 			error = ENXIO;
 			break;
 		}
 		if (!(req->dr_flags & DEVF_FORCE_DETACH)) {
 			error = device_quiesce(dev);
 			if (error)
 				break;
 		}
 		error = device_detach(dev);
 		break;
 	case DEV_ENABLE:
 		if (device_is_enabled(dev)) {
 			error = EBUSY;
 			break;
 		}
 
 		/*
 		 * If the device has been probed but not attached (e.g.
 		 * when it has been disabled by a loader hint), just
 		 * attach the device rather than doing a full probe.
 		 */
 		device_enable(dev);
 		if (device_is_alive(dev)) {
 			/*
 			 * If the device was disabled via a hint, clear
 			 * the hint.
 			 */
 			if (resource_disabled(dev->driver->name, dev->unit))
 				resource_unset_value(dev->driver->name,
 				    dev->unit, "disabled");
 			error = device_attach(dev);
 		} else
 			error = device_probe_and_attach(dev);
 		break;
 	case DEV_DISABLE:
 		if (!device_is_enabled(dev)) {
 			error = ENXIO;
 			break;
 		}
 
 		if (!(req->dr_flags & DEVF_FORCE_DETACH)) {
 			error = device_quiesce(dev);
 			if (error)
 				break;
 		}
 
 		/*
 		 * Force DF_FIXEDCLASS on around detach to preserve
 		 * the existing name.
 		 */
 		old = dev->flags;
 		dev->flags |= DF_FIXEDCLASS;
 		error = device_detach(dev);
 		if (!(old & DF_FIXEDCLASS))
 			dev->flags &= ~DF_FIXEDCLASS;
 		if (error == 0)
 			device_disable(dev);
 		break;
 	case DEV_SUSPEND:
 		if (device_is_suspended(dev)) {
 			error = EBUSY;
 			break;
 		}
 		if (device_get_parent(dev) == NULL) {
 			error = EINVAL;
 			break;
 		}
 		error = BUS_SUSPEND_CHILD(device_get_parent(dev), dev);
 		break;
 	case DEV_RESUME:
 		if (!device_is_suspended(dev)) {
 			error = EINVAL;
 			break;
 		}
 		if (device_get_parent(dev) == NULL) {
 			error = EINVAL;
 			break;
 		}
 		error = BUS_RESUME_CHILD(device_get_parent(dev), dev);
 		break;
 	case DEV_SET_DRIVER: {
 		devclass_t dc;
 		char driver[128];
 
 		error = copyinstr(req->dr_data, driver, sizeof(driver), NULL);
 		if (error)
 			break;
 		if (driver[0] == '\0') {
 			error = EINVAL;
 			break;
 		}
 		if (dev->devclass != NULL &&
 		    strcmp(driver, dev->devclass->name) == 0)
 			/* XXX: Could possibly force DF_FIXEDCLASS on? */
 			break;
 
 		/*
 		 * Scan drivers for this device's bus looking for at
 		 * least one matching driver.
 		 */
 		if (dev->parent == NULL) {
 			error = EINVAL;
 			break;
 		}
 		if (!driver_exists(dev->parent, driver)) {
 			error = ENOENT;
 			break;
 		}
 		dc = devclass_create(driver);
 		if (dc == NULL) {
 			error = ENOMEM;
 			break;
 		}
 
 		/* Detach device if necessary. */
 		if (device_is_attached(dev)) {
 			if (req->dr_flags & DEVF_SET_DRIVER_DETACH)
 				error = device_detach(dev);
 			else
 				error = EBUSY;
 			if (error)
 				break;
 		}
 
 		/* Clear any previously-fixed device class and unit. */
 		if (dev->flags & DF_FIXEDCLASS)
 			devclass_delete_device(dev->devclass, dev);
 		dev->flags |= DF_WILDCARD;
 		dev->unit = -1;
 
 		/* Force the new device class. */
 		error = devclass_add_device(dc, dev);
 		if (error)
 			break;
 		dev->flags |= DF_FIXEDCLASS;
 		error = device_probe_and_attach(dev);
 		break;
 	}
 	case DEV_CLEAR_DRIVER:
 		if (!(dev->flags & DF_FIXEDCLASS)) {
 			error = 0;
 			break;
 		}
 		if (device_is_attached(dev)) {
 			if (req->dr_flags & DEVF_CLEAR_DRIVER_DETACH)
 				error = device_detach(dev);
 			else
 				error = EBUSY;
 			if (error)
 				break;
 		}
 
 		dev->flags &= ~DF_FIXEDCLASS;
 		dev->flags |= DF_WILDCARD;
 		devclass_delete_device(dev->devclass, dev);
 		error = device_probe_and_attach(dev);
 		break;
 	case DEV_RESCAN:
 		if (!device_is_attached(dev)) {
 			error = ENXIO;
 			break;
 		}
 		error = BUS_RESCAN(dev);
 		break;
 	case DEV_DELETE: {
 		device_t parent;
 
 		parent = device_get_parent(dev);
 		if (parent == NULL) {
 			error = EINVAL;
 			break;
 		}
 		if (!(req->dr_flags & DEVF_FORCE_DELETE)) {
 			if (bus_child_present(dev) != 0) {
 				error = EBUSY;
 				break;
 			}
 		}
 		
 		error = device_delete_child(parent, dev);
 		break;
 	}
 	case DEV_FREEZE:
 		if (device_frozen)
 			error = EBUSY;
 		else
 			device_frozen = true;
 		break;
 	case DEV_THAW:
 		if (!device_frozen)
 			error = EBUSY;
 		else {
 			device_do_deferred_actions();
 			device_frozen = false;
 		}
 		break;
 	case DEV_RESET:
 		if ((req->dr_flags & ~(DEVF_RESET_DETACH)) != 0) {
 			error = EINVAL;
 			break;
 		}
 		error = BUS_RESET_CHILD(device_get_parent(dev), dev,
 		    req->dr_flags);
 		break;
 	case DEV_GET_PATH: {
 		struct sbuf *sb;
 		char locator[64];
 		ssize_t len;
 
 		error = copyinstr(req->dr_buffer.buffer, locator,
 		    sizeof(locator), NULL);
 		if (error != 0)
 			break;
 		sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND |
 		    SBUF_INCLUDENUL /* | SBUF_WAITOK */);
 		error = device_get_path(dev, locator, sb);
 		if (error == 0) {
 			len = sbuf_len(sb);
 			if (req->dr_buffer.length < len) {
 				error = ENAMETOOLONG;
 			} else {
 				error = copyout(sbuf_data(sb),
 				    req->dr_buffer.buffer, len);
 			}
 			req->dr_buffer.length = len;
 		}
 		sbuf_delete(sb);
 		break;
 	}
 	}
 	bus_topo_unlock();
 	return (error);
 }
 
 static struct cdevsw devctl2_cdevsw = {
 	.d_version =	D_VERSION,
 	.d_ioctl =	devctl2_ioctl,
 	.d_name =	"devctl2",
 };
 
 static void
 devctl2_init(void)
 {
 	make_dev_credf(MAKEDEV_ETERNAL, &devctl2_cdevsw, 0, NULL,
 	    UID_ROOT, GID_WHEEL, 0644, "devctl2");
 }
 
 /*
  * For maintaining device 'at' location info to avoid recomputing it
  */
 struct device_location_node {
 	const char *dln_locator;
 	const char *dln_path;
 	TAILQ_ENTRY(device_location_node) dln_link;
 };
 typedef TAILQ_HEAD(device_location_list, device_location_node) device_location_list_t;
 
 struct device_location_cache {
 	device_location_list_t dlc_list;
 };
 
 
 /*
  * Location cache for wired devices.
  */
 device_location_cache_t *
 dev_wired_cache_init(void)
 {
 	device_location_cache_t *dcp;
 
 	dcp = malloc(sizeof(*dcp), M_BUS, M_WAITOK | M_ZERO);
 	TAILQ_INIT(&dcp->dlc_list);
 
 	return (dcp);
 }
 
 void
 dev_wired_cache_fini(device_location_cache_t *dcp)
 {
 	struct device_location_node *dln, *tdln;
 
 	TAILQ_FOREACH_SAFE(dln, &dcp->dlc_list, dln_link, tdln) {
 		free(dln, M_BUS);
 	}
 	free(dcp, M_BUS);
 }
 
 static struct device_location_node *
 dev_wired_cache_lookup(device_location_cache_t *dcp, const char *locator)
 {
 	struct device_location_node *dln;
 
 	TAILQ_FOREACH(dln, &dcp->dlc_list, dln_link) {
 		if (strcmp(locator, dln->dln_locator) == 0)
 			return (dln);
 	}
 
 	return (NULL);
 }
 
 static struct device_location_node *
 dev_wired_cache_add(device_location_cache_t *dcp, const char *locator, const char *path)
 {
 	struct device_location_node *dln;
 	size_t loclen, pathlen;
 
 	loclen = strlen(locator) + 1;
 	pathlen = strlen(path) + 1;
 	dln = malloc(sizeof(*dln) + loclen + pathlen, M_BUS, M_WAITOK | M_ZERO);
 	dln->dln_locator = (char *)(dln + 1);
 	memcpy(__DECONST(char *, dln->dln_locator), locator, loclen);
 	dln->dln_path = dln->dln_locator + loclen;
 	memcpy(__DECONST(char *, dln->dln_path), path, pathlen);
 	TAILQ_INSERT_HEAD(&dcp->dlc_list, dln, dln_link);
 
 	return (dln);
 }
 
 bool
 dev_wired_cache_match(device_location_cache_t *dcp, device_t dev,
     const char *at)
 {
 	struct sbuf *sb;
 	const char *cp;
 	char locator[32];
 	int error, len;
 	struct device_location_node *res;
 
 	cp = strchr(at, ':');
 	if (cp == NULL)
 		return (false);
 	len = cp - at;
 	if (len > sizeof(locator) - 1)	/* Skip too long locator */
 		return (false);
 	memcpy(locator, at, len);
 	locator[len] = '\0';
 	cp++;
 
 	error = 0;
 	/* maybe cache this inside device_t and look that up, but not yet */
 	res = dev_wired_cache_lookup(dcp, locator);
 	if (res == NULL) {
 		sb = sbuf_new(NULL, NULL, 0, SBUF_AUTOEXTEND |
 		    SBUF_INCLUDENUL | SBUF_NOWAIT);
 		if (sb != NULL) {
 			error = device_get_path(dev, locator, sb);
 			if (error == 0) {
 				res = dev_wired_cache_add(dcp, locator,
 				    sbuf_data(sb));
 			}
 			sbuf_delete(sb);
 		}
 	}
 	if (error != 0 || res == NULL || res->dln_path == NULL)
 		return (false);
 
 	return (strcmp(res->dln_path, cp) == 0);
 }
 
 static struct device_prop_elm *
 device_prop_find(device_t dev, const char *name)
 {
 	struct device_prop_elm *e;
 
 	bus_topo_assert();
 
 	LIST_FOREACH(e, &dev->props, link) {
 		if (strcmp(name, e->name) == 0)
 			return (e);
 	}
 	return (NULL);
 }
 
 int
 device_set_prop(device_t dev, const char *name, void *val,
     device_prop_dtr_t dtr, void *dtr_ctx)
 {
 	struct device_prop_elm *e, *e1;
 
 	bus_topo_assert();
 
 	e = device_prop_find(dev, name);
 	if (e != NULL)
 		goto found;
 
 	e1 = malloc(sizeof(*e), M_BUS, M_WAITOK);
 	e = device_prop_find(dev, name);
 	if (e != NULL) {
 		free(e1, M_BUS);
 		goto found;
 	}
 
 	e1->name = name;
 	e1->val = val;
 	e1->dtr = dtr;
 	e1->dtr_ctx = dtr_ctx;
 	LIST_INSERT_HEAD(&dev->props, e1, link);
 	return (0);
 
 found:
 	LIST_REMOVE(e, link);
 	if (e->dtr != NULL)
 		e->dtr(dev, name, e->val, e->dtr_ctx);
 	e->val = val;
 	e->dtr = dtr;
 	e->dtr_ctx = dtr_ctx;
 	LIST_INSERT_HEAD(&dev->props, e, link);
 	return (EEXIST);
 }
 
 int
 device_get_prop(device_t dev, const char *name, void **valp)
 {
 	struct device_prop_elm *e;
 
 	bus_topo_assert();
 
 	e = device_prop_find(dev, name);
 	if (e == NULL)
 		return (ENOENT);
 	*valp = e->val;
 	return (0);
 }
 
 int
 device_clear_prop(device_t dev, const char *name)
 {
 	struct device_prop_elm *e;
 
 	bus_topo_assert();
 
 	e = device_prop_find(dev, name);
 	if (e == NULL)
 		return (ENOENT);
 	LIST_REMOVE(e, link);
 	if (e->dtr != NULL)
 		e->dtr(dev, e->name, e->val, e->dtr_ctx);
 	free(e, M_BUS);
 	return (0);
 }
 
 static void
 device_destroy_props(device_t dev)
 {
 	struct device_prop_elm *e;
 
 	bus_topo_assert();
 
 	while ((e = LIST_FIRST(&dev->props)) != NULL) {
 		LIST_REMOVE_HEAD(&dev->props, link);
 		if (e->dtr != NULL)
 			e->dtr(dev, e->name, e->val, e->dtr_ctx);
 		free(e, M_BUS);
 	}
 }
 
 void
 device_clear_prop_alldev(const char *name)
 {
 	device_t dev;
 
 	TAILQ_FOREACH(dev, &bus_data_devices, devlink) {
 		device_clear_prop(dev, name);
 	}
 }
 
 /*
  * APIs to manage deprecation and obsolescence.
  */
 static int obsolete_panic = 0;
 SYSCTL_INT(_debug, OID_AUTO, obsolete_panic, CTLFLAG_RWTUN, &obsolete_panic, 0,
     "Panic when obsolete features are used (0 = never, 1 = if obsolete, "
     "2 = if deprecated)");
 
 static void
 gone_panic(int major, int running, const char *msg)
 {
 	switch (obsolete_panic)
 	{
 	case 0:
 		return;
 	case 1:
 		if (running < major)
 			return;
 		/* FALLTHROUGH */
 	default:
 		panic("%s", msg);
 	}
 }
 
 void
 _gone_in(int major, const char *msg)
 {
 	gone_panic(major, P_OSREL_MAJOR(__FreeBSD_version), msg);
 	if (P_OSREL_MAJOR(__FreeBSD_version) >= major)
 		printf("Obsolete code will be removed soon: %s\n", msg);
 	else
 		printf("Deprecated code (to be removed in FreeBSD %d): %s\n",
 		    major, msg);
 }
 
 void
 _gone_in_dev(device_t dev, int major, const char *msg)
 {
 	gone_panic(major, P_OSREL_MAJOR(__FreeBSD_version), msg);
 	if (P_OSREL_MAJOR(__FreeBSD_version) >= major)
 		device_printf(dev,
 		    "Obsolete code will be removed soon: %s\n", msg);
 	else
 		device_printf(dev,
 		    "Deprecated code (to be removed in FreeBSD %d): %s\n",
 		    major, msg);
 }
 
 #ifdef DDB
 DB_SHOW_COMMAND(device, db_show_device)
 {
 	device_t dev;
 
 	if (!have_addr)
 		return;
 
 	dev = (device_t)addr;
 
 	db_printf("name:    %s\n", device_get_nameunit(dev));
 	db_printf("  driver:  %s\n", DRIVERNAME(dev->driver));
 	db_printf("  class:   %s\n", DEVCLANAME(dev->devclass));
 	db_printf("  addr:    %p\n", dev);
 	db_printf("  parent:  %p\n", dev->parent);
 	db_printf("  softc:   %p\n", dev->softc);
 	db_printf("  ivars:   %p\n", dev->ivars);
 }
 
 DB_SHOW_ALL_COMMAND(devices, db_show_all_devices)
 {
 	device_t dev;
 
 	TAILQ_FOREACH(dev, &bus_data_devices, devlink) {
 		db_show_device((db_expr_t)dev, true, count, modif);
 	}
 }
 #endif