/******************************************************************************
* Talks to Xen Store to figure out what devices we have.
*
* Copyright (C) 2009, 2010 Spectra Logic Corporation
* Copyright (C) 2008 Doug Rabson
* Copyright (C) 2005 Rusty Russell, IBM Corporation
* Copyright (C) 2005 Mike Wray, Hewlett-Packard
* Copyright (C) 2005 XenSource Ltd
*
* This file may be distributed separately from the Linux kernel, or
* incorporated into other software packages, subject to the following license:
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this source file (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use, copy, modify,
* merge, publish, distribute, sublicense, and/or sell copies of the Software,
* and to permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
/**
* \file xenbusb_front.c
*
* XenBus management of the NewBus bus containing the frontend instances of
* Xen split devices.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/sbuf.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <sys/systm.h>
#include <sys/sx.h>
#include <sys/taskqueue.h>
#include <machine/stdarg.h>
#include <xen/xen-os.h>
#include <xen/gnttab.h>
#include <xen/xenbus/xenbusvar.h>
#include <xen/xenbus/xenbusb.h>
/*------------------ Private Device Attachment Functions --------------------*/
/**
* \brief Probe for the existance of the XenBus front bus.
*
* \param dev NewBus device_t for this XenBus front bus instance.
*
* \return Always returns 0 indicating success.
*/
static int
xenbusb_front_probe(device_t dev)
{
device_set_desc(dev, "Xen Frontend Devices");
return (0);
}
/**
* \brief Attach the XenBus front bus.
*
* \param dev NewBus device_t for this XenBus front bus instance.
*
* \return On success, 0. Otherwise an errno value indicating the
* type of failure.
*/
static int
xenbusb_front_attach(device_t dev)
{
return (xenbusb_attach(dev, "device", /*id_components*/1));
}
/**
* \brief Enumerate all devices of the given type on this bus.
*
* \param dev NewBus device_t for this XenBus front bus instance.
* \param type String indicating the device sub-tree (e.g. "vfb", "vif")
* to enumerate.
*
* \return On success, 0. Otherwise an errno value indicating the
* type of failure.
*
* Devices that are found are entered into the NewBus hierarchy via
* xenbusb_add_device(). xenbusb_add_device() ignores duplicate detects
* and ignores duplicate devices, so it can be called unconditionally
* for any device found in the XenStore.
*/
static int
xenbusb_front_enumerate_type(device_t dev, const char *type)
{
struct xenbusb_softc *xbs;
const char **dir;
unsigned int i, count;
int error;
xbs = device_get_softc(dev);
error = xs_directory(XST_NIL, xbs->xbs_node, type, &count, &dir);
if (error)
return (error);
for (i = 0; i < count; i++)
xenbusb_add_device(dev, type, dir[i]);
free(dir, M_XENSTORE);
return (0);
}
/**
* \brief Determine and store the XenStore path for the other end of
* a split device whose local end is represented by ivars.
*
* If successful, the xd_otherend_path field of the child's instance
* variables will be updated.
*
* \param dev NewBus device_t for this XenBus front bus instance.
* \param ivars Instance variables from the XenBus child device for
* which to perform this function.
*
* \return On success, 0. Otherwise an errno value indicating the
* type of failure.
*/
static int
xenbusb_front_get_otherend_node(device_t dev, struct xenbus_device_ivars *ivars)
{
char *otherend_path;
int error;
if (ivars->xd_otherend_path != NULL) {
free(ivars->xd_otherend_path, M_XENBUS);
ivars->xd_otherend_path = NULL;
}
error = xs_gather(XST_NIL, ivars->xd_node,
"backend-id", "%i", &ivars->xd_otherend_id,
"backend", NULL, &otherend_path,
NULL);
if (error == 0) {
ivars->xd_otherend_path = strdup(otherend_path, M_XENBUS);
ivars->xd_otherend_path_len = strlen(otherend_path);
free(otherend_path, M_XENSTORE);
}
return (error);
}
/*-------------------- Private Device Attachment Data -----------------------*/
static device_method_t xenbusb_front_methods[] = {
/* Device interface */
DEVMETHOD(device_identify, xenbusb_identify),
DEVMETHOD(device_probe, xenbusb_front_probe),
DEVMETHOD(device_attach, xenbusb_front_attach),
DEVMETHOD(device_detach, bus_generic_detach),
DEVMETHOD(device_shutdown, bus_generic_shutdown),
DEVMETHOD(device_suspend, bus_generic_suspend),
DEVMETHOD(device_resume, xenbusb_resume),
/* Bus Interface */
DEVMETHOD(bus_print_child, xenbusb_print_child),
DEVMETHOD(bus_read_ivar, xenbusb_read_ivar),
DEVMETHOD(bus_write_ivar, xenbusb_write_ivar),
DEVMETHOD(bus_alloc_resource, bus_generic_alloc_resource),
DEVMETHOD(bus_release_resource, bus_generic_release_resource),
DEVMETHOD(bus_activate_resource, bus_generic_activate_resource),
DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource),
/* XenBus Bus Interface */
DEVMETHOD(xenbusb_enumerate_type, xenbusb_front_enumerate_type),
DEVMETHOD(xenbusb_get_otherend_node, xenbusb_front_get_otherend_node),
{ 0, 0 }
};
DEFINE_CLASS_0(xenbusb_front, xenbusb_front_driver, xenbusb_front_methods,
sizeof(struct xenbusb_softc));
devclass_t xenbusb_front_devclass;
DRIVER_MODULE(xenbusb_front, xenstore, xenbusb_front_driver,
xenbusb_front_devclass, 0, 0);
