core/sysbus: remove the SysBusDeviceClass::init path

Currently, all sysbus devices have been converted to realize(),
so remove this path.

Cc: ehabkost@redhat.com
Cc: thuth@redhat.com
Cc: pbonzini@redhat.com
Cc: armbru@redhat.com
Cc: peter.maydell@linaro.org
Cc: richard.henderson@linaro.org
Cc: alistair.francis@wdc.com

Signed-off-by: Mao Zhongyi <maozhongyi@cmss.chinamobile.com>
Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Message-id: 20181130093852.20739-22-maozhongyi@cmss.chinamobile.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

hw/core/sysbus.c

@@ -201,18 +201,13 @@ void sysbus_init_ioports(SysBusDevice *dev, uint32_t ioport, uint32_t size)
     }
 }
 
-/* TODO remove once all sysbus devices have been converted to realize */
+/* The purpose of preserving this empty realize function
+ * is to prevent the parent_realize field of some subclasses
+ * from being set to NULL to break the normal init/realize
+ * of some devices.
+ */
 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;
-    }
-    if (sbc->init(sd) < 0) {
-        error_setg(errp, "Device initialization failed");
-    }
 }
 
 DeviceState *sysbus_create_varargs(const char *name,

include/hw/sysbus.h

@@ -38,9 +38,6 @@ typedef struct SysBusDevice SysBusDevice;
 typedef struct SysBusDeviceClass {
     /*< private >*/
     DeviceClass parent_class;
-    /*< public >*/
-
-    int (*init)(SysBusDevice *dev);
 
     /*
      * Let the sysbus device format its own non-PIO, non-MMIO unit address.