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of the devices we manage. These changes can be due to writes we make ourselves or due to changes made by the control domain. The goal of these changes is to insure that all state transitions can be detected regardless of their source and to allow common device policies (e.g. "onlined" backend devices) to be centralized in the XenBus bus code. sys/xen/xenbus/xenbusvar.h: sys/xen/xenbus/xenbus.c: sys/xen/xenbus/xenbus_if.m: Add a new method for XenBus drivers "localend_changed". This method is invoked whenever a write is detected to a device's XenBus tree. The default implementation of this method is a no-op. sys/xen/xenbus/xenbus_if.m: sys/dev/xen/netfront/netfront.c: sys/dev/xen/blkfront/blkfront.c: sys/dev/xen/blkback/blkback.c: Change the signature of the "otherend_changed" method. This notification cannot fail, so it should return void. sys/xen/xenbus/xenbusb_back.c: Add "online" device handling to the XenBus Back Bus support code. An online backend device remains active after a front-end detaches as a reconnect is expected to occur in the near future. sys/xen/interface/io/xenbus.h: Add comment block further explaining the meaning and driver responsibilities associated with the XenBus Closed state. sys/xen/xenbus/xenbusb.c: sys/xen/xenbus/xenbusb.h: sys/xen/xenbus/xenbusb_back.c: sys/xen/xenbus/xenbusb_front.c: sys/xen/xenbus/xenbusb_if.m: o Register a XenStore watch against the local XenBus tree for all devices. o Cache the string length of the path to our local tree. o Allow the xenbus front and back drivers to hook/filter both local and otherend watch processing. o Update the device ivar version of "state" when we detect a XenStore update of that node. sys/dev/xen/control/control.c: sys/xen/xenbus/xenbus.c: sys/xen/xenbus/xenbusb.c: sys/xen/xenbus/xenbusb.h: sys/xen/xenbus/xenbusvar.h: sys/xen/xenstore/xenstorevar.h: Allow clients of the XenStore watch mechanism to attach a single uintptr_t worth of client data to the watch. This removes the need to carefully place client watch data within enclosing objects so that a cast or offsetof calculation can be used to convert from watch to enclosing object. Sponsored by: Spectra Logic Corporation MFC after: 1 week
197 lines
6.3 KiB
C
197 lines
6.3 KiB
C
/******************************************************************************
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* Talks to Xen Store to figure out what devices we have.
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*
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* Copyright (C) 2009, 2010 Spectra Logic Corporation
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* Copyright (C) 2008 Doug Rabson
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* Copyright (C) 2005 Rusty Russell, IBM Corporation
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* Copyright (C) 2005 Mike Wray, Hewlett-Packard
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* Copyright (C) 2005 XenSource Ltd
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*
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* This file may be distributed separately from the Linux kernel, or
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* incorporated into other software packages, subject to the following license:
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this source file (the "Software"), to deal in the Software without
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* restriction, including without limitation the rights to use, copy, modify,
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* merge, publish, distribute, sublicense, and/or sell copies of the Software,
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* and to permit persons to whom the Software is furnished to do so, subject to
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* the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
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* IN THE SOFTWARE.
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*/
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/**
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* \file xenbusb_front.c
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*
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* XenBus management of the NewBus bus containing the frontend instances of
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* Xen split devices.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/bus.h>
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#include <sys/kernel.h>
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#include <sys/lock.h>
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#include <sys/malloc.h>
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#include <sys/module.h>
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#include <sys/sbuf.h>
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#include <sys/sysctl.h>
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#include <sys/syslog.h>
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#include <sys/systm.h>
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#include <sys/sx.h>
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#include <sys/taskqueue.h>
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#include <machine/xen/xen-os.h>
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#include <machine/stdarg.h>
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#include <xen/gnttab.h>
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#include <xen/xenbus/xenbusvar.h>
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#include <xen/xenbus/xenbusb.h>
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/*------------------ Private Device Attachment Functions --------------------*/
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/**
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* \brief Probe for the existance of the XenBus front bus.
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*
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* \param dev NewBus device_t for this XenBus front bus instance.
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*
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* \return Always returns 0 indicating success.
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*/
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static int
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xenbusb_front_probe(device_t dev)
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{
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device_set_desc(dev, "Xen Frontend Devices");
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return (0);
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}
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/**
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* \brief Attach the XenBus front bus.
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*
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* \param dev NewBus device_t for this XenBus front bus instance.
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*
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* \return On success, 0. Otherwise an errno value indicating the
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* type of failure.
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*/
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static int
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xenbusb_front_attach(device_t dev)
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{
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return (xenbusb_attach(dev, "device", /*id_components*/1));
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}
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/**
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* \brief Enumerate all devices of the given type on this bus.
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*
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* \param dev NewBus device_t for this XenBus front bus instance.
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* \param type String indicating the device sub-tree (e.g. "vfb", "vif")
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* to enumerate.
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*
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* \return On success, 0. Otherwise an errno value indicating the
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* type of failure.
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*
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* Devices that are found are entered into the NewBus hierarchy via
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* xenbusb_add_device(). xenbusb_add_device() ignores duplicate detects
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* and ignores duplicate devices, so it can be called unconditionally
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* for any device found in the XenStore.
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*/
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static int
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xenbusb_front_enumerate_type(device_t dev, const char *type)
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{
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struct xenbusb_softc *xbs;
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const char **dir;
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unsigned int i, count;
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int error;
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xbs = device_get_softc(dev);
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error = xs_directory(XST_NIL, xbs->xbs_node, type, &count, &dir);
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if (error)
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return (error);
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for (i = 0; i < count; i++)
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xenbusb_add_device(dev, type, dir[i]);
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free(dir, M_XENSTORE);
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return (0);
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}
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/**
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* \brief Determine and store the XenStore path for the other end of
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* a split device whose local end is represented by ivars.
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*
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* If successful, the xd_otherend_path field of the child's instance
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* variables will be updated.
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*
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* \param dev NewBus device_t for this XenBus front bus instance.
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* \param ivars Instance variables from the XenBus child device for
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* which to perform this function.
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*
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* \return On success, 0. Otherwise an errno value indicating the
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* type of failure.
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*/
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static int
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xenbusb_front_get_otherend_node(device_t dev, struct xenbus_device_ivars *ivars)
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{
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char *otherend_path;
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int error;
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if (ivars->xd_otherend_path != NULL) {
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free(ivars->xd_otherend_path, M_XENBUS);
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ivars->xd_otherend_path = NULL;
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}
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error = xs_gather(XST_NIL, ivars->xd_node,
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"backend-id", "%i", &ivars->xd_otherend_id,
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"backend", NULL, &otherend_path,
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NULL);
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if (error == 0) {
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ivars->xd_otherend_path = strdup(otherend_path, M_XENBUS);
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ivars->xd_otherend_path_len = strlen(otherend_path);
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free(otherend_path, M_XENSTORE);
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}
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return (error);
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}
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/*-------------------- Private Device Attachment Data -----------------------*/
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static device_method_t xenbusb_front_methods[] = {
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/* Device interface */
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DEVMETHOD(device_identify, xenbusb_identify),
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DEVMETHOD(device_probe, xenbusb_front_probe),
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DEVMETHOD(device_attach, xenbusb_front_attach),
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DEVMETHOD(device_detach, bus_generic_detach),
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DEVMETHOD(device_shutdown, bus_generic_shutdown),
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DEVMETHOD(device_suspend, bus_generic_suspend),
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DEVMETHOD(device_resume, bus_generic_resume),
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/* Bus Interface */
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DEVMETHOD(bus_print_child, xenbusb_print_child),
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DEVMETHOD(bus_read_ivar, xenbusb_read_ivar),
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DEVMETHOD(bus_write_ivar, xenbusb_write_ivar),
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DEVMETHOD(bus_alloc_resource, bus_generic_alloc_resource),
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DEVMETHOD(bus_release_resource, bus_generic_release_resource),
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DEVMETHOD(bus_activate_resource, bus_generic_activate_resource),
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DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource),
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/* XenBus Bus Interface */
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DEVMETHOD(xenbusb_enumerate_type, xenbusb_front_enumerate_type),
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DEVMETHOD(xenbusb_get_otherend_node, xenbusb_front_get_otherend_node),
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{ 0, 0 }
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};
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DEFINE_CLASS_0(xenbusb_front, xenbusb_front_driver, xenbusb_front_methods,
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sizeof(struct xenbusb_softc));
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devclass_t xenbusb_front_devclass;
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DRIVER_MODULE(xenbusb_front, xenstore, xenbusb_front_driver,
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xenbusb_front_devclass, 0, 0);
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