s390x/css: Unplug handler of virtual css bridge

The previous patch moved virtual css bridge and bus out from
virtio-ccw, but kept the direct reference of virtio-ccw specific
unplug function inside css-bridge.c.

To make the virtual css bus and bridge useful for non-virtio devices,
this introduces a common unplug function pointer "unplug" to call
specific virtio-ccw unplug parts. Thus, the tight coupling to
virtio-ccw can be removed.

This unplug pointer is a member of CCWDeviceClass, which is introduced
as an abstract device layer called "ccw-device". This layer is between
DeviceState and specific devices which are plugged in virtual css bus,
like virtio-ccw device. The specific unplug handlers should be assigned
to "unplug" during initialization.

Signed-off-by: Jing Liu <liujbjl@linux.vnet.ibm.com>
Reviewed-by: Sascha Silbe <silbe@linux.vnet.ibm.com>
Reviewed-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Reviewed-by: Yi Min Zhao <zyimin@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>

1 files changed, 27 insertions, 0 deletions

diff --git a/hw/s390x/ccw-device.c b/hw/s390x/ccw-device.c
new file mode 100644
index 0000000000..28ea20440e
--- /dev/null
+++ b/hw/s390x/ccw-device.c
@@ -0,0 +1,27 @@
+/*
+ * Common device infrastructure for devices in the virtual css
+ *
+ * Copyright 2016 IBM Corp.
+ * Author(s): Jing Liu <liujbjl@linux.vnet.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or (at
+ * your option) any later version. See the COPYING file in the top-level
+ * directory.
+ */
+#include "qemu/osdep.h"
+#include "ccw-device.h"
+
+static const TypeInfo ccw_device_info = {
+    .name = TYPE_CCW_DEVICE,
+    .parent = TYPE_DEVICE,
+    .instance_size = sizeof(CcwDevice),
+    .class_size = sizeof(CCWDeviceClass),
+    .abstract = true,
+};
+
+static void ccw_device_register(void)
+{
+    type_register_static(&ccw_device_info);
+}
+
+type_init(ccw_device_register)