[Qemu-devel] [PATCH v3 3/4] qdev: Simplify the SysBusDeviceClass::init path

["Philippe Mathieu-Daudé" <f4bug@amsat.org>]

The SysBusDevice is the last DeviceClass::init user.

Instead of using
  SysBusDeviceClass::realize
   -> DeviceClass::realize
       -> DeviceClass::init
           -> sysbus_device_init
              -> SysBusDeviceClass::init

Simplify the path by directly calling SysBusDeviceClass::init
in SysBusDeviceClass::realize:

  SysBusDeviceClass::realize
   -> SysBusDeviceClass::init

Finally, remove the DeviceClass::init, there are no more users.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 include/hw/qdev-core.h |  2 --
 hw/core/qdev.c         | 14 --------------
 hw/core/sysbus.c       | 15 ++++++++++-----
 3 files changed, 10 insertions(+), 21 deletions(-)

diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
index 9453588160..6f60748043 100644
--- a/include/hw/qdev-core.h
+++ b/include/hw/qdev-core.h
@@ -29,7 +29,6 @@ typedef enum DeviceCategory {
     DEVICE_CATEGORY_MAX
 } DeviceCategory;
 
-typedef int (*qdev_initfn)(DeviceState *dev);
 typedef int (*qdev_event)(DeviceState *dev);
 typedef void (*DeviceRealize)(DeviceState *dev, Error **errp);
 typedef void (*DeviceUnrealize)(DeviceState *dev, Error **errp);
@@ -124,7 +123,6 @@ typedef struct DeviceClass {
     const struct VMStateDescription *vmsd;
 
     /* Private to qdev / bus.  */
-    qdev_initfn init; /* TODO remove, once users are converted to realize */
     qdev_event exit; /* TODO remove, once users are converted to unrealize */
     const char *bus_type;
 } DeviceClass;
diff --git a/hw/core/qdev.c b/hw/core/qdev.c
index f6f92473b8..4153b733c8 100644
--- a/hw/core/qdev.c
+++ b/hw/core/qdev.c
@@ -208,19 +208,6 @@ void device_listener_unregister(DeviceListener *listener)
     QTAILQ_REMOVE(&device_listeners, listener, link);
 }
 
-static void device_realize(DeviceState *dev, Error **errp)
-{
-    DeviceClass *dc = DEVICE_GET_CLASS(dev);
-
-    if (dc->init) {
-        int rc = dc->init(dev);
-        if (rc < 0) {
-            error_setg(errp, "Device initialization failed.");
-            return;
-        }
-    }
-}
-
 static void device_unrealize(DeviceState *dev, Error **errp)
 {
     DeviceClass *dc = DEVICE_GET_CLASS(dev);
@@ -1065,7 +1052,6 @@ static void device_class_init(ObjectClass *class, void *data)
     DeviceClass *dc = DEVICE_CLASS(class);
 
     class->unparent = device_unparent;
-    dc->realize = device_realize;
     dc->unrealize = device_unrealize;
 
     /* by default all devices were considered as hotpluggable,
diff --git a/hw/core/sysbus.c b/hw/core/sysbus.c
index 5d0887f499..11f6d14b84 100644
--- a/hw/core/sysbus.c
+++ b/hw/core/sysbus.c
@@ -18,6 +18,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "qapi/error.h"
 #include "hw/sysbus.h"
 #include "monitor/monitor.h"
 #include "exec/address-spaces.h"
@@ -200,15 +201,19 @@ void sysbus_init_ioports(SysBusDevice *dev, uint32_t ioport, uint32_t size)
     }
 }
 
-static int sysbus_device_init(DeviceState *dev)
+static void sysbus_realize(DeviceState *dev, Error **errp)
 {
     SysBusDevice *sd = SYS_BUS_DEVICE(dev);
     SysBusDeviceClass *sbc = SYS_BUS_DEVICE_GET_CLASS(sd);
 
-    if (!sbc->init) {
-        return 0;
+    /* TODO remove, once users are converted to realize */
+    if (sbc->init) {
+        int rc = sbc->init(sd);
+        if (rc < 0) {
+            error_setg(errp, "Device initialization failed.");
+            return;
+        }
     }
-    return sbc->init(sd);
 }
 
 DeviceState *sysbus_create_varargs(const char *name,
@@ -324,7 +329,7 @@ MemoryRegion *sysbus_address_space(SysBusDevice *dev)
 static void sysbus_device_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *k = DEVICE_CLASS(klass);
-    k->init = sysbus_device_init;
+    k->realize = sysbus_realize;
     k->bus_type = TYPE_SYSTEM_BUS;
     /*
      * device_add plugs devices into a suitable bus.  For "real" buses,
-- 
2.17.0