hw/core: Remove transitional infrastructure from BusClass

BusClass currently has transitional infrastructure to support
subclasses which implement the legacy BusClass::reset method rather
than the Resettable interface.  We have now removed all the users of
BusClass::reset in the tree, so we can remove the transitional
infrastructure.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Cédric Le Goater <clg@redhat.com>
Acked-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Tested-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Message-id: 20240119163512.3810301-6-peter.maydell@linaro.org

hw/core/bus.c

@@ -232,57 +232,6 @@ static char *default_bus_get_fw_dev_path(DeviceState *dev)
     return g_strdup(object_get_typename(OBJECT(dev)));
 }
 
-/**
- * bus_phases_reset:
- * Transition reset method for buses to allow moving
- * smoothly from legacy reset method to multi-phases
- */
-static void bus_phases_reset(BusState *bus)
-{
-    ResettableClass *rc = RESETTABLE_GET_CLASS(bus);
-
-    if (rc->phases.enter) {
-        rc->phases.enter(OBJECT(bus), RESET_TYPE_COLD);
-    }
-    if (rc->phases.hold) {
-        rc->phases.hold(OBJECT(bus));
-    }
-    if (rc->phases.exit) {
-        rc->phases.exit(OBJECT(bus));
-    }
-}
-
-static void bus_transitional_reset(Object *obj)
-{
-    BusClass *bc = BUS_GET_CLASS(obj);
-
-    /*
-     * This will call either @bus_phases_reset (for multi-phases transitioned
-     * buses) or a bus's specific method for not-yet transitioned buses.
-     * In both case, it does not reset children.
-     */
-    if (bc->reset) {
-        bc->reset(BUS(obj));
-    }
-}
-
-/**
- * bus_get_transitional_reset:
- * check if the bus's class is ready for multi-phase
- */
-static ResettableTrFunction bus_get_transitional_reset(Object *obj)
-{
-    BusClass *dc = BUS_GET_CLASS(obj);
-    if (dc->reset != bus_phases_reset) {
-        /*
-         * dc->reset has been overridden by a subclass,
-         * the bus is not ready for multi phase yet.
-         */
-        return bus_transitional_reset;
-    }
-    return NULL;
-}
-
 static void bus_class_init(ObjectClass *class, void *data)
 {
     BusClass *bc = BUS_CLASS(class);
@@ -293,22 +242,6 @@ static void bus_class_init(ObjectClass *class, void *data)
 
     rc->get_state = bus_get_reset_state;
     rc->child_foreach = bus_reset_child_foreach;
-
-    /*
-     * @bus_phases_reset is put as the default reset method below, allowing
-     * to do the multi-phase transition from base classes to leaf classes. It
-     * allows a legacy-reset Bus class to extend a multi-phases-reset
-     * Bus class for the following reason:
-     * + If a base class B has been moved to multi-phase, then it does not
-     *   override this default reset method and may have defined phase methods.
-     * + A child class C (extending class B) which uses
-     *   bus_class_set_parent_reset() (or similar means) to override the
-     *   reset method will still work as expected. @bus_phases_reset function
-     *   will be registered as the parent reset method and effectively call
-     *   parent reset phases.
-     */
-    bc->reset = bus_phases_reset;
-    rc->get_transitional_function = bus_get_transitional_reset;
 }
 
 static void qbus_finalize(Object *obj)

include/hw/qdev-core.h

@@ -329,8 +329,6 @@ struct BusClass {
      */
     char *(*get_fw_dev_path)(DeviceState *dev);
 
-    void (*reset)(BusState *bus);
-
     /*
      * Return whether the device can be added to @bus,
      * based on the address that was set (via device properties)