define hotplug interface

Provide a generic hotplug interface for hotplug handlers.
Intended for replacing hotplug mechanism used by
PCI/PCIE/SHPC code and will be used for memory hotplug.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/core/Makefile.objs

@@ -2,6 +2,7 @@
 common-obj-y += qdev.o qdev-properties.o
 # irq.o needed for qdev GPIO handling:
 common-obj-y += irq.o
+common-obj-y += hotplug.o
 
 common-obj-$(CONFIG_EMPTY_SLOT) += empty_slot.o
 common-obj-$(CONFIG_XILINX_AXI) += stream.o

hw/core/hotplug.c

@@ -0,0 +1,48 @@
+/*
+ * Hotplug handler interface.
+ *
+ * Copyright (c) 2014 Red Hat Inc.
+ *
+ * Authors:
+ *  Igor Mammedov <imammedo@redhat.com>,
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+#include "hw/hotplug.h"
+#include "qemu/module.h"
+
+void hotplug_handler_plug(HotplugHandler *plug_handler,
+                          DeviceState *plugged_dev,
+                          Error **errp)
+{
+    HotplugHandlerClass *hdc = HOTPLUG_HANDLER_GET_CLASS(plug_handler);
+
+    if (hdc->plug) {
+        hdc->plug(plug_handler, plugged_dev, errp);
+    }
+}
+
+void hotplug_handler_unplug(HotplugHandler *plug_handler,
+                            DeviceState *plugged_dev,
+                            Error **errp)
+{
+    HotplugHandlerClass *hdc = HOTPLUG_HANDLER_GET_CLASS(plug_handler);
+
+    if (hdc->unplug) {
+        hdc->unplug(plug_handler, plugged_dev, errp);
+    }
+}
+
+static const TypeInfo hotplug_handler_info = {
+    .name          = TYPE_HOTPLUG_HANDLER,
+    .parent        = TYPE_INTERFACE,
+    .class_size = sizeof(HotplugHandlerClass),
+};
+
+static void hotplug_handler_register_types(void)
+{
+    type_register_static(&hotplug_handler_info);
+}
+
+type_init(hotplug_handler_register_types)

include/hw/hotplug.h

@@ -0,0 +1,78 @@
+/*
+ * Hotplug handler interface.
+ *
+ * Copyright (c) 2014 Red Hat Inc.
+ *
+ * Authors:
+ *  Igor Mammedov <imammedo@redhat.com>,
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+#ifndef HOTPLUG_H
+#define HOTPLUG_H
+
+#include "qom/object.h"
+#include "qemu/typedefs.h"
+
+#define TYPE_HOTPLUG_HANDLER "hotplug-handler"
+
+#define HOTPLUG_HANDLER_CLASS(klass) \
+     OBJECT_CLASS_CHECK(HotplugHandlerClass, (klass), TYPE_HOTPLUG_HANDLER)
+#define HOTPLUG_HANDLER_GET_CLASS(obj) \
+     OBJECT_GET_CLASS(HotplugHandlerClass, (obj), TYPE_HOTPLUG_HANDLER)
+#define HOTPLUG_HANDLER(obj) \
+     INTERFACE_CHECK(HotplugHandler, (obj), TYPE_HOTPLUG_HANDLER)
+
+
+typedef struct HotplugHandler {
+    /* <private> */
+    Object Parent;
+} HotplugHandler;
+
+/**
+ * hotplug_fn:
+ * @plug_handler: a device performing plug/uplug action
+ * @plugged_dev: a device that has been (un)plugged
+ * @errp: returns an error if this function fails
+ */
+typedef void (*hotplug_fn)(HotplugHandler *plug_handler,
+                           DeviceState *plugged_dev, Error **errp);
+
+/**
+ * HotplugDeviceClass:
+ *
+ * Interface to be implemented by a device performing
+ * hardware (un)plug functions.
+ *
+ * @parent: Opaque parent interface.
+ * @plug: plug callback.
+ * @unplug: unplug callback.
+ */
+typedef struct HotplugHandlerClass {
+    /* <private> */
+    InterfaceClass parent;
+
+    /* <public> */
+    hotplug_fn plug;
+    hotplug_fn unplug;
+} HotplugHandlerClass;
+
+/**
+ * hotplug_handler_plug:
+ *
+ * Call #HotplugHandlerClass.plug callback of @plug_handler.
+ */
+void hotplug_handler_plug(HotplugHandler *plug_handler,
+                          DeviceState *plugged_dev,
+                          Error **errp);
+
+/**
+ * hotplug_handler_unplug:
+ *
+ * Call #HotplugHandlerClass.unplug callback of @plug_handler.
+ */
+void hotplug_handler_unplug(HotplugHandler *plug_handler,
+                            DeviceState *plugged_dev,
+                            Error **errp);
+#endif