static int tpmback_probe(struct xenbus_device *dev,
const struct xenbus_device_id *id)
{
int err;
struct backend_info *be = kzalloc(sizeof(struct backend_info),
GFP_KERNEL);
if (!be) {
xenbus_dev_fatal(dev, -ENOMEM,
"allocating backend structure");
return -ENOMEM;
}
be->is_instance_set = 0;
be->dev = dev;
dev->data = be;
err = xenbus_watch_path2(dev, dev->nodename,
"instance", &be->backend_watch,
backend_changed);
if (err) {
goto fail;
}
err = xenbus_switch_state(dev, XenbusStateInitWait);
if (err) {
goto fail;
}
return 0;
fail:
tpmback_remove(dev);
return err;
}
static void frontend_changed(struct xenbus_device *dev,
enum xenbus_state frontend_state)
{
struct backend_info *be = dev->data;
int err;
be->frontend_state = frontend_state;
switch (frontend_state) {
case XenbusStateInitialising:
case XenbusStateInitialised:
break;
case XenbusStateConnected:
err = connect_ring(be);
if (err) {
return;
}
maybe_connect(be);
break;
case XenbusStateClosing:
be->tpmif->tpm_instance = -1;
break;
case XenbusStateClosed:
/*
* Notify the vTPM manager about the front-end
* having left.
*/
tpmif_vtpm_close(be->instance);
device_unregister(&be->dev->dev);
tpmback_remove(dev);
break;
case XenbusStateUnknown:
case XenbusStateInitWait:
default:
xenbus_dev_fatal(dev, -EINVAL,
"saw state %d at frontend",
frontend_state);
break;
}
}
static void frontend_changed(struct xenbus_device *dev,
enum xenbus_state frontend_state)
{
struct backend_info *be = dev->dev.driver_data;
int err;
switch (frontend_state) {
case XenbusStateInitialising:
case XenbusStateInitialised:
break;
case XenbusStateConnected:
err = connect_ring(be);
if (err) {
return;
}
maybe_connect(be);
break;
case XenbusStateClosing:
be->instance = -1;
break;
case XenbusStateUnknown:
case XenbusStateClosed:
device_unregister(&be->dev->dev);
tpmback_remove(dev);
break;
default:
xenbus_dev_fatal(dev, -EINVAL,
"saw state %d at frontend",
frontend_state);
break;
}
}