qemu

bus.c (9509B)

---

 /*
  *  Dynamic device configuration and creation -- buses.
  *
  *  Copyright (c) 2009 CodeSourcery
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  */
 
 #include "qemu/osdep.h"
 #include "hw/qdev-properties.h"
 #include "qemu/ctype.h"
 #include "qemu/module.h"
 #include "qapi/error.h"
 
 void qbus_set_hotplug_handler(BusState *bus, Object *handler)
 {
     object_property_set_link(OBJECT(bus), QDEV_HOTPLUG_HANDLER_PROPERTY,
                              handler, &error_abort);
 }
 
 void qbus_set_bus_hotplug_handler(BusState *bus)
 {
     qbus_set_hotplug_handler(bus, OBJECT(bus));
 }
 
 int qbus_walk_children(BusState *bus,
                        qdev_walkerfn *pre_devfn, qbus_walkerfn *pre_busfn,
                        qdev_walkerfn *post_devfn, qbus_walkerfn *post_busfn,
                        void *opaque)
 {
     BusChild *kid;
     int err;
 
     if (pre_busfn) {
         err = pre_busfn(bus, opaque);
         if (err) {
             return err;
         }
     }
 
     WITH_RCU_READ_LOCK_GUARD() {
         QTAILQ_FOREACH_RCU(kid, &bus->children, sibling) {
             err = qdev_walk_children(kid->child,
                                      pre_devfn, pre_busfn,
                                      post_devfn, post_busfn, opaque);
             if (err < 0) {
                 return err;
             }
         }
     }
 
     if (post_busfn) {
         err = post_busfn(bus, opaque);
         if (err) {
             return err;
         }
     }
 
     return 0;
 }
 
 void bus_cold_reset(BusState *bus)
 {
     resettable_reset(OBJECT(bus), RESET_TYPE_COLD);
 }
 
 bool bus_is_in_reset(BusState *bus)
 {
     return resettable_is_in_reset(OBJECT(bus));
 }
 
 static ResettableState *bus_get_reset_state(Object *obj)
 {
     BusState *bus = BUS(obj);
     return &bus->reset;
 }
 
 static void bus_reset_child_foreach(Object *obj, ResettableChildCallback cb,
                                     void *opaque, ResetType type)
 {
     BusState *bus = BUS(obj);
     BusChild *kid;
 
     WITH_RCU_READ_LOCK_GUARD() {
         QTAILQ_FOREACH_RCU(kid, &bus->children, sibling) {
             cb(OBJECT(kid->child), opaque, type);
         }
     }
 }
 
 static void qbus_init_internal(BusState *bus, DeviceState *parent,
                                const char *name)
 {
     const char *typename = object_get_typename(OBJECT(bus));
     BusClass *bc;
     int i, bus_id;
 
     bus->parent = parent;
 
     if (name) {
         bus->name = g_strdup(name);
     } else if (bus->parent && bus->parent->id) {
         /* parent device has id -> use it plus parent-bus-id for bus name */
         bus_id = bus->parent->num_child_bus;
         bus->name = g_strdup_printf("%s.%d", bus->parent->id, bus_id);
     } else {
         /* no id -> use lowercase bus type plus global bus-id for bus name */
         bc = BUS_GET_CLASS(bus);
         bus_id = bc->automatic_ids++;
         bus->name = g_strdup_printf("%s.%d", typename, bus_id);
         for (i = 0; bus->name[i]; i++) {
             bus->name[i] = qemu_tolower(bus->name[i]);
         }
     }
 
     if (bus->parent) {
         QLIST_INSERT_HEAD(&bus->parent->child_bus, bus, sibling);
         bus->parent->num_child_bus++;
         object_property_add_child(OBJECT(bus->parent), bus->name, OBJECT(bus));
         object_unref(OBJECT(bus));
     } else {
         /* The only bus without a parent is the main system bus */
         assert(bus == sysbus_get_default());
     }
 }
 
 static void bus_unparent(Object *obj)
 {
     BusState *bus = BUS(obj);
     BusChild *kid;
 
     /* Only the main system bus has no parent, and that bus is never freed */
     assert(bus->parent);
 
     while ((kid = QTAILQ_FIRST(&bus->children)) != NULL) {
         DeviceState *dev = kid->child;
         object_unparent(OBJECT(dev));
     }
     QLIST_REMOVE(bus, sibling);
     bus->parent->num_child_bus--;
     bus->parent = NULL;
 }
 
 void qbus_init(void *bus, size_t size, const char *typename,
                DeviceState *parent, const char *name)
 {
     object_initialize(bus, size, typename);
     qbus_init_internal(bus, parent, name);
 }
 
 BusState *qbus_new(const char *typename, DeviceState *parent, const char *name)
 {
     BusState *bus;
 
     bus = BUS(object_new(typename));
     qbus_init_internal(bus, parent, name);
 
     return bus;
 }
 
 bool qbus_realize(BusState *bus, Error **errp)
 {
     return object_property_set_bool(OBJECT(bus), "realized", true, errp);
 }
 
 void qbus_unrealize(BusState *bus)
 {
     object_property_set_bool(OBJECT(bus), "realized", false, &error_abort);
 }
 
 static bool bus_get_realized(Object *obj, Error **errp)
 {
     BusState *bus = BUS(obj);
 
     return bus->realized;
 }
 
 static void bus_set_realized(Object *obj, bool value, Error **errp)
 {
     BusState *bus = BUS(obj);
     BusClass *bc = BUS_GET_CLASS(bus);
     BusChild *kid;
 
     if (value && !bus->realized) {
         if (bc->realize) {
             bc->realize(bus, errp);
         }
 
         /* TODO: recursive realization */
     } else if (!value && bus->realized) {
         WITH_RCU_READ_LOCK_GUARD() {
             QTAILQ_FOREACH_RCU(kid, &bus->children, sibling) {
                 DeviceState *dev = kid->child;
                 qdev_unrealize(dev);
             }
         }
         if (bc->unrealize) {
             bc->unrealize(bus);
         }
     }
 
     bus->realized = value;
 }
 
 static void qbus_initfn(Object *obj)
 {
     BusState *bus = BUS(obj);
 
     QTAILQ_INIT(&bus->children);
     object_property_add_link(obj, QDEV_HOTPLUG_HANDLER_PROPERTY,
                              TYPE_HOTPLUG_HANDLER,
                              (Object **)&bus->hotplug_handler,
                              object_property_allow_set_link,
                              0);
     object_property_add_bool(obj, "realized",
                              bus_get_realized, bus_set_realized);
 }
 
 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);
     ResettableClass *rc = RESETTABLE_CLASS(class);
 
     class->unparent = bus_unparent;
     bc->get_fw_dev_path = default_bus_get_fw_dev_path;
 
     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)
 {
     BusState *bus = BUS(obj);
 
     g_free(bus->name);
 }
 
 static const TypeInfo bus_info = {
     .name = TYPE_BUS,
     .parent = TYPE_OBJECT,
     .instance_size = sizeof(BusState),
     .abstract = true,
     .class_size = sizeof(BusClass),
     .instance_init = qbus_initfn,
     .instance_finalize = qbus_finalize,
     .class_init = bus_class_init,
     .interfaces = (InterfaceInfo[]) {
         { TYPE_RESETTABLE_INTERFACE },
         { }
     },
 };
 
 static void bus_register_types(void)
 {
     type_register_static(&bus_info);
 }
 
 type_init(bus_register_types)