- 根目录:
- drivers
- hv
- vmbus_drv.c
/*
* Copyright (c) 2009, Microsoft Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 59 Temple
* Place - Suite 330, Boston, MA 02111-1307 USA.
*
* Authors:
* Haiyang Zhang <haiyangz@microsoft.com>
* Hank Janssen <hjanssen@microsoft.com>
* K. Y. Srinivasan <kys@microsoft.com>
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/sysctl.h>
#include <linux/slab.h>
#include <linux/acpi.h>
#include <acpi/acpi_bus.h>
#include <linux/completion.h>
#include <linux/hyperv.h>
#include <asm/hyperv.h>
#include "hyperv_vmbus.h"
static struct acpi_device *hv_acpi_dev;
static struct tasklet_struct msg_dpc;
static struct tasklet_struct event_dpc;
static struct completion probe_event;
static int irq;
struct hv_device_info {
u32 chn_id;
u32 chn_state;
uuid_le chn_type;
uuid_le chn_instance;
u32 monitor_id;
u32 server_monitor_pending;
u32 server_monitor_latency;
u32 server_monitor_conn_id;
u32 client_monitor_pending;
u32 client_monitor_latency;
u32 client_monitor_conn_id;
struct hv_dev_port_info inbound;
struct hv_dev_port_info outbound;
};
static int vmbus_exists(void)
{
if (hv_acpi_dev == NULL)
return -ENODEV;
return 0;
}
static void get_channel_info(struct hv_device *device,
struct hv_device_info *info)
{
struct vmbus_channel_debug_info debug_info;
if (!device->channel)
return;
vmbus_get_debug_info(device->channel, &debug_info);
info->chn_id = debug_info.relid;
info->chn_state = debug_info.state;
memcpy(&info->chn_type, &debug_info.interfacetype,
sizeof(uuid_le));
memcpy(&info->chn_instance, &debug_info.interface_instance,
sizeof(uuid_le));
info->monitor_id = debug_info.monitorid;
info->server_monitor_pending = debug_info.servermonitor_pending;
info->server_monitor_latency = debug_info.servermonitor_latency;
info->server_monitor_conn_id = debug_info.servermonitor_connectionid;
info->client_monitor_pending = debug_info.clientmonitor_pending;
info->client_monitor_latency = debug_info.clientmonitor_latency;
info->client_monitor_conn_id = debug_info.clientmonitor_connectionid;
info->inbound.int_mask = debug_info.inbound.current_interrupt_mask;
info->inbound.read_idx = debug_info.inbound.current_read_index;
info->inbound.write_idx = debug_info.inbound.current_write_index;
info->inbound.bytes_avail_toread =
debug_info.inbound.bytes_avail_toread;
info->inbound.bytes_avail_towrite =
debug_info.inbound.bytes_avail_towrite;
info->outbound.int_mask =
debug_info.outbound.current_interrupt_mask;
info->outbound.read_idx = debug_info.outbound.current_read_index;
info->outbound.write_idx = debug_info.outbound.current_write_index;
info->outbound.bytes_avail_toread =
debug_info.outbound.bytes_avail_toread;
info->outbound.bytes_avail_towrite =
debug_info.outbound.bytes_avail_towrite;
}
#define VMBUS_ALIAS_LEN ((sizeof((struct hv_vmbus_device_id *)0)->guid) * 2)
static void print_alias_name(struct hv_device *hv_dev, char *alias_name)
{
int i;
for (i = 0; i < VMBUS_ALIAS_LEN; i += 2)
sprintf(&alias_name[i], "%02x", hv_dev->dev_type.b[i/2]);
}
/*
* vmbus_show_device_attr - Show the device attribute in sysfs.
*
* This is invoked when user does a
* "cat /sys/bus/vmbus/devices/<busdevice>/<attr name>"
*/
static ssize_t vmbus_show_device_attr(struct device *dev,
struct device_attribute *dev_attr,
char *buf)
{
struct hv_device *hv_dev = device_to_hv_device(dev);
struct hv_device_info *device_info;
char alias_name[VMBUS_ALIAS_LEN + 1];
int ret = 0;
device_info = kzalloc(sizeof(struct hv_device_info), GFP_KERNEL);
if (!device_info)
return ret;
get_channel_info(hv_dev, device_info);
if (!strcmp(dev_attr->attr.name, "class_id")) {
ret = sprintf(buf, "{%02x%02x%02x%02x-%02x%02x-%02x%02x-"
"%02x%02x%02x%02x%02x%02x%02x%02x}\n",
device_info->chn_type.b[3],
device_info->chn_type.b[2],
device_info->chn_type.b[1],
device_info->chn_type.b[0],
device_info->chn_type.b[5],
device_info->chn_type.b[4],
device_info->chn_type.b[7],
device_info->chn_type.b[6],
device_info->chn_type.b[8],
device_info->chn_type.b[9],
device_info->chn_type.b[10],
device_info->chn_type.b[11],
device_info->chn_type.b[12],
device_info->chn_type.b[13],
device_info->chn_type.b[14],
device_info->chn_type.b[15]);
} else if (!strcmp(dev_attr->attr.name, "device_id")) {
ret = sprintf(buf, "{%02x%02x%02x%02x-%02x%02x-%02x%02x-"
"%02x%02x%02x%02x%02x%02x%02x%02x}\n",
device_info->chn_instance.b[3],
device_info->chn_instance.b[2],
device_info->chn_instance.b[1],
device_info->chn_instance.b[0],
device_info->chn_instance.b[5],
device_info->chn_instance.b[4],
device_info->chn_instance.b[7],
device_info->chn_instance.b[6],
device_info->chn_instance.b[8],
device_info->chn_instance.b[9],
device_info->chn_instance.b[10],
device_info->chn_instance.b[11],
device_info->chn_instance.b[12],
device_info->chn_instance.b[13],
device_info->chn_instance.b[14],
device_info->chn_instance.b[15]);
} else if (!strcmp(dev_attr->attr.name, "modalias")) {
print_alias_name(hv_dev, alias_name);
ret = sprintf(buf, "vmbus:%s\n", alias_name);
} else if (!strcmp(dev_attr->attr.name, "state")) {
ret = sprintf(buf, "%d\n", device_info->chn_state);
} else if (!strcmp(dev_attr->attr.name, "id")) {
ret = sprintf(buf, "%d\n", device_info->chn_id);
} else if (!strcmp(dev_attr->attr.name, "out_intr_mask")) {
ret = sprintf(buf, "%d\n", device_info->outbound.int_mask);
} else if (!strcmp(dev_attr->attr.name, "out_read_index")) {
ret = sprintf(buf, "%d\n", device_info->outbound.read_idx);
} else if (!strcmp(dev_attr->attr.name, "out_write_index")) {
ret = sprintf(buf, "%d\n", device_info->outbound.write_idx);
} else if (!strcmp(dev_attr->attr.name, "out_read_bytes_avail")) {
ret = sprintf(buf, "%d\n",
device_info->outbound.bytes_avail_toread);
} else if (!strcmp(dev_attr->attr.name, "out_write_bytes_avail")) {
ret = sprintf(buf, "%d\n",
device_info->outbound.bytes_avail_towrite);
} else if (!strcmp(dev_attr->attr.name, "in_intr_mask")) {
ret = sprintf(buf, "%d\n", device_info->inbound.int_mask);
} else if (!strcmp(dev_attr->attr.name, "in_read_index")) {
ret = sprintf(buf, "%d\n", device_info->inbound.read_idx);
} else if (!strcmp(dev_attr->attr.name, "in_write_index")) {
ret = sprintf(buf, "%d\n", device_info->inbound.write_idx);
} else if (!strcmp(dev_attr->attr.name, "in_read_bytes_avail")) {
ret = sprintf(buf, "%d\n",
device_info->inbound.bytes_avail_toread);
} else if (!strcmp(dev_attr->attr.name, "in_write_bytes_avail")) {
ret = sprintf(buf, "%d\n",
device_info->inbound.bytes_avail_towrite);
} else if (!strcmp(dev_attr->attr.name, "monitor_id")) {
ret = sprintf(buf, "%d\n", device_info->monitor_id);
} else if (!strcmp(dev_attr->attr.name, "server_monitor_pending")) {
ret = sprintf(buf, "%d\n", device_info->server_monitor_pending);
} else if (!strcmp(dev_attr->attr.name, "server_monitor_latency")) {
ret = sprintf(buf, "%d\n", device_info->server_monitor_latency);
} else if (!strcmp(dev_attr->attr.name, "server_monitor_conn_id")) {
ret = sprintf(buf, "%d\n",
device_info->server_monitor_conn_id);
} else if (!strcmp(dev_attr->attr.name, "client_monitor_pending")) {
ret = sprintf(buf, "%d\n", device_info->client_monitor_pending);
} else if (!strcmp(dev_attr->attr.name, "client_monitor_latency")) {
ret = sprintf(buf, "%d\n", device_info->client_monitor_latency);
} else if (!strcmp(dev_attr->attr.name, "client_monitor_conn_id")) {
ret = sprintf(buf, "%d\n",
device_info->client_monitor_conn_id);
}
kfree(device_info);
return ret;
}
/* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
static struct device_attribute vmbus_device_attrs[] = {
__ATTR(id, S_IRUGO, vmbus_show_device_attr, NULL),
__ATTR(state, S_IRUGO, vmbus_show_device_attr, NULL),
__ATTR(class_id, S_IRUGO, vmbus_show_device_attr, NULL),
__ATTR(device_id, S_IRUGO, vmbus_show_device_attr, NULL),
__ATTR(monitor_id, S_IRUGO, vmbus_show_device_attr, NULL),
__ATTR(modalias, S_IRUGO, vmbus_show_device_attr, NULL),
__ATTR(server_monitor_pending, S_IRUGO, vmbus_show_device_attr, NULL),
__ATTR(server_monitor_latency, S_IRUGO, vmbus_show_device_attr, NULL),
__ATTR(server_monitor_conn_id, S_IRUGO, vmbus_show_device_attr, NULL),
__ATTR(client_monitor_pending, S_IRUGO, vmbus_show_device_attr, NULL),
__ATTR(client_monitor_latency, S_IRUGO, vmbus_show_device_attr, NULL),
__ATTR(client_monitor_conn_id, S_IRUGO, vmbus_show_device_attr, NULL),
__ATTR(out_intr_mask, S_IRUGO, vmbus_show_device_attr, NULL),
__ATTR(out_read_index, S_IRUGO, vmbus_show_device_attr, NULL),
__ATTR(out_write_index, S_IRUGO, vmbus_show_device_attr, NULL),
__ATTR(out_read_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
__ATTR(out_write_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
__ATTR(in_intr_mask, S_IRUGO, vmbus_show_device_attr, NULL),
__ATTR(in_read_index, S_IRUGO, vmbus_show_device_attr, NULL),
__ATTR(in_write_index, S_IRUGO, vmbus_show_device_attr, NULL),
__ATTR(in_read_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
__ATTR(in_write_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
__ATTR_NULL
};
/*
* vmbus_uevent - add uevent for our device
*
* This routine is invoked when a device is added or removed on the vmbus to
* generate a uevent to udev in the userspace. The udev will then look at its
* rule and the uevent generated here to load the appropriate driver
*
* The alias string will be of the form vmbus:guid where guid is the string
* representation of the device guid (each byte of the guid will be
* represented with two hex characters.
*/
static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env)
{
struct hv_device *dev = device_to_hv_device(device);
int ret;
char alias_name[VMBUS_ALIAS_LEN + 1];
print_alias_name(dev, alias_name);
ret = add_uevent_var(env, "MODALIAS=vmbus:%s", alias_name);
return ret;
}
static uuid_le null_guid;
static inline bool is_null_guid(const __u8 *guid)
{
if (memcmp(guid, &null_guid, sizeof(uuid_le)))
return false;
return true;
}
/*
* Return a matching hv_vmbus_device_id pointer.
* If there is no match, return NULL.
*/
static const struct hv_vmbus_device_id *hv_vmbus_get_id(
const struct hv_vmbus_device_id *id,
__u8 *guid)
{
for (; !is_null_guid(id->guid); id++)
if (!memcmp(&id->guid, guid, sizeof(uuid_le)))
return id;
return NULL;
}
/*
* vmbus_match - Attempt to match the specified device to the specified driver
*/
static int vmbus_match(struct device *device, struct device_driver *driver)
{
struct hv_driver *drv = drv_to_hv_drv(driver);
struct hv_device *hv_dev = device_to_hv_device(device);
if (hv_vmbus_get_id(drv->id_table, hv_dev->dev_type.b))
return 1;
return 0;
}
/*
* vmbus_probe - Add the new vmbus's child device
*/
static int vmbus_probe(struct device *child_device)
{
int ret = 0;
struct hv_driver *drv =
drv_to_hv_drv(child_device->driver);
struct hv_device *dev = device_to_hv_device(child_device);
const struct hv_vmbus_device_id *dev_id;
dev_id = hv_vmbus_get_id(drv->id_table, dev->dev_type.b);
if (drv->probe) {
ret = drv->probe(dev, dev_id);
if (ret != 0)
pr_err("probe failed for device %s (%d)\n",
dev_name(child_device), ret);
} else {
pr_err("probe not set for driver %s\n",
dev_name(child_device));
ret = -ENODEV;
}
return ret;
}
/*
* vmbus_remove - Remove a vmbus device
*/
static int vmbus_remove(struct device *child_device)
{
struct hv_driver *drv = drv_to_hv_drv(child_device->driver);
struct hv_device *dev = device_to_hv_device(child_device);
if (drv->remove)
drv->remove(dev);
else
pr_err("remove not set for driver %s\n",
dev_name(child_device));
return 0;
}
/*
* vmbus_shutdown - Shutdown a vmbus device
*/
static void vmbus_shutdown(struct device *child_device)
{
struct hv_driver *drv;
struct hv_device *dev = device_to_hv_device(child_device);
/* The device may not be attached yet */
if (!child_device->driver)
return;
drv = drv_to_hv_drv(child_device->driver);
if (drv->shutdown)
drv->shutdown(dev);
return;
}
/*
* vmbus_device_release - Final callback release of the vmbus child device
*/
static void vmbus_device_release(struct device *device)
{
struct hv_device *hv_dev = device_to_hv_device(device);
kfree(hv_dev);
}
/* The one and only one */
static struct bus_type hv_bus = {
.name = "vmbus",
.match = vmbus_match,
.shutdown = vmbus_shutdown,
.remove = vmbus_remove,
.probe = vmbus_probe,
.uevent = vmbus_uevent,
.dev_attrs = vmbus_device_attrs,
};
static const char *driver_name = "hyperv";
struct onmessage_work_context {
struct work_struct work;
struct hv_message msg;
};
static void vmbus_onmessage_work(struct work_struct *work)
{
struct onmessage_work_context *ctx;
ctx = container_of(work, struct onmessage_work_context,
work);
vmbus_onmessage(&ctx->msg);
kfree(ctx);
}
static void vmbus_on_msg_dpc(unsigned long data)
{
int cpu = smp_processor_id();
void *page_addr = hv_context.synic_message_page[cpu];
struct hv_message *msg = (struct hv_message *)page_addr +
VMBUS_MESSAGE_SINT;
struct onmessage_work_context *ctx;
while (1) {
if (msg->header.message_type == HVMSG_NONE) {
/* no msg */
break;
} else {
ctx = kmalloc(sizeof(*ctx), GFP_ATOMIC);
if (ctx == NULL)
continue;
INIT_WORK(&ctx->work, vmbus_onmessage_work);
memcpy(&ctx->msg, msg, sizeof(*msg));
queue_work(vmbus_connection.work_queue, &ctx->work);
}
msg->header.message_type = HVMSG_NONE;
/*
* Make sure the write to MessageType (ie set to
* HVMSG_NONE) happens before we read the
* MessagePending and EOMing. Otherwise, the EOMing
* will not deliver any more messages since there is
* no empty slot
*/
smp_mb();
if (msg->header.message_flags.msg_pending) {
/*
* This will cause message queue rescan to
* possibly deliver another msg from the
* hypervisor
*/
wrmsrl(HV_X64_MSR_EOM, 0);
}
}
}
static irqreturn_t vmbus_isr(int irq, void *dev_id)
{
int cpu = smp_processor_id();
void *page_addr;
struct hv_message *msg;
union hv_synic_event_flags *event;
bool handled = false;
/*
* Check for events before checking for messages. This is the order
* in which events and messages are checked in Windows guests on
* Hyper-V, and the Windows team suggested we do the same.
*/
page_addr = hv_context.synic_event_page[cpu];
event = (union hv_synic_event_flags *)page_addr + VMBUS_MESSAGE_SINT;
/* Since we are a child, we only need to check bit 0 */
if (sync_test_and_clear_bit(0, (unsigned long *) &event->flags32[0])) {
handled = true;
tasklet_schedule(&event_dpc);
}
page_addr = hv_context.synic_message_page[cpu];
msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
/* Check if there are actual msgs to be processed */
if (msg->header.message_type != HVMSG_NONE) {
handled = true;
tasklet_schedule(&msg_dpc);
}
if (handled)
return IRQ_HANDLED;
else
return IRQ_NONE;
}
/*
* vmbus_bus_init -Main vmbus driver initialization routine.
*
* Here, we
* - initialize the vmbus driver context
* - invoke the vmbus hv main init routine
* - get the irq resource
* - retrieve the channel offers
*/
static int vmbus_bus_init(int irq)
{
int ret;
unsigned int vector;
/* Hypervisor initialization...setup hypercall page..etc */
ret = hv_init();
if (ret != 0) {
pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
return ret;
}
tasklet_init(&msg_dpc, vmbus_on_msg_dpc, 0);
tasklet_init(&event_dpc, vmbus_on_event, 0);
ret = bus_register(&hv_bus);
if (ret)
goto err_cleanup;
ret = request_irq(irq, vmbus_isr, IRQF_SAMPLE_RANDOM,
driver_name, hv_acpi_dev);
if (ret != 0) {
pr_err("Unable to request IRQ %d\n",
irq);
goto err_unregister;
}
vector = IRQ0_VECTOR + irq;
/*
* Notify the hypervisor of our irq and
* connect to the host.
*/
on_each_cpu(hv_synic_init, (void *)&vector, 1);
ret = vmbus_connect();
if (ret)
goto err_irq;
vmbus_request_offers();
return 0;
err_irq:
free_irq(irq, hv_acpi_dev);
err_unregister:
bus_unregister(&hv_bus);
err_cleanup:
hv_cleanup();
return ret;
}
/**
* __vmbus_child_driver_register - Register a vmbus's driver
* @drv: Pointer to driver structure you want to register
* @owner: owner module of the drv
* @mod_name: module name string
*
* Registers the given driver with Linux through the 'driver_register()' call
* and sets up the hyper-v vmbus handling for this driver.
* It will return the state of the 'driver_register()' call.
*
*/
int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
{
int ret;
pr_info("registering driver %s\n", hv_driver->name);
ret = vmbus_exists();
if (ret < 0)
return ret;
hv_driver->driver.name = hv_driver->name;
hv_driver->driver.owner = owner;
hv_driver->driver.mod_name = mod_name;
hv_driver->driver.bus = &hv_bus;
ret = driver_register(&hv_driver->driver);
vmbus_request_offers();
return ret;
}
EXPORT_SYMBOL_GPL(__vmbus_driver_register);
/**
* vmbus_driver_unregister() - Unregister a vmbus's driver
* @drv: Pointer to driver structure you want to un-register
*
* Un-register the given driver that was previous registered with a call to
* vmbus_driver_register()
*/
void vmbus_driver_unregister(struct hv_driver *hv_driver)
{
pr_info("unregistering driver %s\n", hv_driver->name);
if (!vmbus_exists())
driver_unregister(&hv_driver->driver);
}
EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
/*
* vmbus_device_create - Creates and registers a new child device
* on the vmbus.
*/
struct hv_device *vmbus_device_create(uuid_le *type,
uuid_le *instance,
struct vmbus_channel *channel)
{
struct hv_device *child_device_obj;
child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
if (!child_device_obj) {
pr_err("Unable to allocate device object for child device\n");
return NULL;
}
child_device_obj->channel = channel;
memcpy(&child_device_obj->dev_type, type, sizeof(uuid_le));
memcpy(&child_device_obj->dev_instance, instance,
sizeof(uuid_le));
return child_device_obj;
}
/*
* vmbus_device_register - Register the child device
*/
int vmbus_device_register(struct hv_device *child_device_obj)
{
int ret = 0;
static atomic_t device_num = ATOMIC_INIT(0);
dev_set_name(&child_device_obj->device, "vmbus_0_%d",
atomic_inc_return(&device_num));
child_device_obj->device.bus = &hv_bus;
child_device_obj->device.parent = &hv_acpi_dev->dev;
child_device_obj->device.release = vmbus_device_release;
/*
* Register with the LDM. This will kick off the driver/device
* binding...which will eventually call vmbus_match() and vmbus_probe()
*/
ret = device_register(&child_device_obj->device);
if (ret)
pr_err("Unable to register child device\n");
else
pr_info("child device %s registered\n",
dev_name(&child_device_obj->device));
return ret;
}
/*
* vmbus_device_unregister - Remove the specified child device
* from the vmbus.
*/
void vmbus_device_unregister(struct hv_device *device_obj)
{
/*
* Kick off the process of unregistering the device.
* This will call vmbus_remove() and eventually vmbus_device_release()
*/
device_unregister(&device_obj->device);
pr_info("child device %s unregistered\n",
dev_name(&device_obj->device));
}
/*
* VMBUS is an acpi enumerated device. Get the the IRQ information
* from DSDT.
*/
static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *irq)
{
if (res->type == ACPI_RESOURCE_TYPE_IRQ) {
struct acpi_resource_irq *irqp;
irqp = &res->data.irq;
*((unsigned int *)irq) = irqp->interrupts[0];
}
return AE_OK;
}
static int vmbus_acpi_add(struct acpi_device *device)
{
acpi_status result;
hv_acpi_dev = device;
result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
vmbus_walk_resources, &irq);
if (ACPI_FAILURE(result)) {
complete(&probe_event);
return -ENODEV;
}
complete(&probe_event);
return 0;
}
static const struct acpi_device_id vmbus_acpi_device_ids[] = {
{"VMBUS", 0},
{"VMBus", 0},
{"", 0},
};
MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
static struct acpi_driver vmbus_acpi_driver = {
.name = "vmbus",
.ids = vmbus_acpi_device_ids,
.ops = {
.add = vmbus_acpi_add,
},
};
static int __init hv_acpi_init(void)
{
int ret, t;
init_completion(&probe_event);
/*
* Get irq resources first.
*/
ret = acpi_bus_register_driver(&vmbus_acpi_driver);
if (ret)
return ret;
t = wait_for_completion_timeout(&probe_event, 5*HZ);
if (t == 0) {
ret = -ETIMEDOUT;
goto cleanup;
}
if (irq <= 0) {
ret = -ENODEV;
goto cleanup;
}
ret = vmbus_bus_init(irq);
if (ret)
goto cleanup;
return 0;
cleanup:
acpi_bus_unregister_driver(&vmbus_acpi_driver);
hv_acpi_dev = NULL;
return ret;
}
static void __exit vmbus_exit(void)
{
free_irq(irq, hv_acpi_dev);
vmbus_free_channels();
bus_unregister(&hv_bus);
hv_cleanup();
acpi_bus_unregister_driver(&vmbus_acpi_driver);
}
MODULE_LICENSE("GPL");
MODULE_VERSION(HV_DRV_VERSION);
subsys_initcall(hv_acpi_init);
module_exit(vmbus_exit);