hw/core/bus.c

   1 /*
   2  *  Dynamic device configuration and creation -- buses.
   3  *
   4  *  Copyright (c) 2009 CodeSourcery
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "qemu/osdep.h"
  21 #include "hw/qdev-properties.h"
  22 #include "qemu/ctype.h"
  23 #include "qemu/module.h"
  24 #include "qapi/error.h"
  25
  26 void qbus_set_hotplug_handler(BusState *bus, Object *handler, Error **errp)
  27 {
  28     object_property_set_link(OBJECT(bus), OBJECT(handler),
  29                              QDEV_HOTPLUG_HANDLER_PROPERTY, errp);
  30 }
  31
  32 void qbus_set_bus_hotplug_handler(BusState *bus, Error **errp)
  33 {
  34     qbus_set_hotplug_handler(bus, OBJECT(bus), errp);
  35 }
  36
  37 int qbus_walk_children(BusState *bus,
  38                        qdev_walkerfn *pre_devfn, qbus_walkerfn *pre_busfn,
  39                        qdev_walkerfn *post_devfn, qbus_walkerfn *post_busfn,
  40                        void *opaque)
  41 {
  42     BusChild *kid;
  43     int err;
  44
  45     if (pre_busfn) {
  46         err = pre_busfn(bus, opaque);
  47         if (err) {
  48             return err;
  49         }
  50     }
  51
  52     QTAILQ_FOREACH(kid, &bus->children, sibling) {
  53         err = qdev_walk_children(kid->child,
  54                                  pre_devfn, pre_busfn,
  55                                  post_devfn, post_busfn, opaque);
  56         if (err < 0) {
  57             return err;
  58         }
  59     }
  60
  61     if (post_busfn) {
  62         err = post_busfn(bus, opaque);
  63         if (err) {
  64             return err;
  65         }
  66     }
  67
  68     return 0;
  69 }
  70
  71 void bus_cold_reset(BusState *bus)
  72 {
  73     resettable_reset(OBJECT(bus), RESET_TYPE_COLD);
  74 }
  75
  76 bool bus_is_in_reset(BusState *bus)
  77 {
  78     return resettable_is_in_reset(OBJECT(bus));
  79 }
  80
  81 static ResettableState *bus_get_reset_state(Object *obj)
  82 {
  83     BusState *bus = BUS(obj);
  84     return &bus->reset;
  85 }
  86
  87 static void bus_reset_child_foreach(Object *obj, ResettableChildCallback cb,
  88                                     void *opaque, ResetType type)
  89 {
  90     BusState *bus = BUS(obj);
  91     BusChild *kid;
  92
  93     QTAILQ_FOREACH(kid, &bus->children, sibling) {
  94         cb(OBJECT(kid->child), opaque, type);
  95     }
  96 }
  97
  98 static void qbus_realize(BusState *bus, DeviceState *parent, const char *name)
  99 {
 100     const char *typename = object_get_typename(OBJECT(bus));
 101     BusClass *bc;
 102     int i, bus_id;
 103
 104     bus->parent = parent;
 105
 106     if (name) {
 107         bus->name = g_strdup(name);
 108     } else if (bus->parent && bus->parent->id) {
 109         /* parent device has id -> use it plus parent-bus-id for bus name */
 110         bus_id = bus->parent->num_child_bus;
 111         bus->name = g_strdup_printf("%s.%d", bus->parent->id, bus_id);
 112     } else {
 113         /* no id -> use lowercase bus type plus global bus-id for bus name */
 114         bc = BUS_GET_CLASS(bus);
 115         bus_id = bc->automatic_ids++;
 116         bus->name = g_strdup_printf("%s.%d", typename, bus_id);
 117         for (i = 0; bus->name[i]; i++) {
 118             bus->name[i] = qemu_tolower(bus->name[i]);
 119         }
 120     }
 121
 122     if (bus->parent) {
 123         QLIST_INSERT_HEAD(&bus->parent->child_bus, bus, sibling);
 124         bus->parent->num_child_bus++;
 125         object_property_add_child(OBJECT(bus->parent), bus->name, OBJECT(bus));
 126         object_unref(OBJECT(bus));
 127     } else {
 128         /* The only bus without a parent is the main system bus */
 129         assert(bus == sysbus_get_default());
 130     }
 131 }
 132
 133 static void bus_unparent(Object *obj)
 134 {
 135     BusState *bus = BUS(obj);
 136     BusChild *kid;
 137
 138     /* Only the main system bus has no parent, and that bus is never freed */
 139     assert(bus->parent);
 140
 141     while ((kid = QTAILQ_FIRST(&bus->children)) != NULL) {
 142         DeviceState *dev = kid->child;
 143         object_unparent(OBJECT(dev));
 144     }
 145     QLIST_REMOVE(bus, sibling);
 146     bus->parent->num_child_bus--;
 147     bus->parent = NULL;
 148 }
 149
 150 void qbus_create_inplace(void *bus, size_t size, const char *typename,
 151                          DeviceState *parent, const char *name)
 152 {
 153     object_initialize(bus, size, typename);
 154     qbus_realize(bus, parent, name);
 155 }
 156
 157 BusState *qbus_create(const char *typename, DeviceState *parent, const char *name)
 158 {
 159     BusState *bus;
 160
 161     bus = BUS(object_new(typename));
 162     qbus_realize(bus, parent, name);
 163
 164     return bus;
 165 }
 166
 167 static bool bus_get_realized(Object *obj, Error **errp)
 168 {
 169     BusState *bus = BUS(obj);
 170
 171     return bus->realized;
 172 }
 173
 174 static void bus_set_realized(Object *obj, bool value, Error **errp)
 175 {
 176     BusState *bus = BUS(obj);
 177     BusClass *bc = BUS_GET_CLASS(bus);
 178     BusChild *kid;
 179
 180     if (value && !bus->realized) {
 181         if (bc->realize) {
 182             bc->realize(bus, errp);
 183         }
 184
 185         /* TODO: recursive realization */
 186     } else if (!value && bus->realized) {
 187         QTAILQ_FOREACH(kid, &bus->children, sibling) {
 188             DeviceState *dev = kid->child;
 189             object_property_set_bool(OBJECT(dev), false, "realized",
 190                                      &error_abort);
 191         }
 192         if (bc->unrealize) {
 193             bc->unrealize(bus);
 194         }
 195     }
 196
 197     bus->realized = value;
 198 }
 199
 200 static void qbus_initfn(Object *obj)
 201 {
 202     BusState *bus = BUS(obj);
 203
 204     QTAILQ_INIT(&bus->children);
 205     object_property_add_link(obj, QDEV_HOTPLUG_HANDLER_PROPERTY,
 206                              TYPE_HOTPLUG_HANDLER,
 207                              (Object **)&bus->hotplug_handler,
 208                              object_property_allow_set_link,
 209                              0);
 210     object_property_add_bool(obj, "realized",
 211                              bus_get_realized, bus_set_realized);
 212 }
 213
 214 static char *default_bus_get_fw_dev_path(DeviceState *dev)
 215 {
 216     return g_strdup(object_get_typename(OBJECT(dev)));
 217 }
 218
 219 /**
 220  * bus_phases_reset:
 221  * Transition reset method for buses to allow moving
 222  * smoothly from legacy reset method to multi-phases
 223  */
 224 static void bus_phases_reset(BusState *bus)
 225 {
 226     ResettableClass *rc = RESETTABLE_GET_CLASS(bus);
 227
 228     if (rc->phases.enter) {
 229         rc->phases.enter(OBJECT(bus), RESET_TYPE_COLD);
 230     }
 231     if (rc->phases.hold) {
 232         rc->phases.hold(OBJECT(bus));
 233     }
 234     if (rc->phases.exit) {
 235         rc->phases.exit(OBJECT(bus));
 236     }
 237 }
 238
 239 static void bus_transitional_reset(Object *obj)
 240 {
 241     BusClass *bc = BUS_GET_CLASS(obj);
 242
 243     /*
 244      * This will call either @bus_phases_reset (for multi-phases transitioned
 245      * buses) or a bus's specific method for not-yet transitioned buses.
 246      * In both case, it does not reset children.
 247      */
 248     if (bc->reset) {
 249         bc->reset(BUS(obj));
 250     }
 251 }
 252
 253 /**
 254  * bus_get_transitional_reset:
 255  * check if the bus's class is ready for multi-phase
 256  */
 257 static ResettableTrFunction bus_get_transitional_reset(Object *obj)
 258 {
 259     BusClass *dc = BUS_GET_CLASS(obj);
 260     if (dc->reset != bus_phases_reset) {
 261         /*
 262          * dc->reset has been overridden by a subclass,
 263          * the bus is not ready for multi phase yet.
 264          */
 265         return bus_transitional_reset;
 266     }
 267     return NULL;
 268 }
 269
 270 static void bus_class_init(ObjectClass *class, void *data)
 271 {
 272     BusClass *bc = BUS_CLASS(class);
 273     ResettableClass *rc = RESETTABLE_CLASS(class);
 274
 275     class->unparent = bus_unparent;
 276     bc->get_fw_dev_path = default_bus_get_fw_dev_path;
 277
 278     rc->get_state = bus_get_reset_state;
 279     rc->child_foreach = bus_reset_child_foreach;
 280
 281     /*
 282      * @bus_phases_reset is put as the default reset method below, allowing
 283      * to do the multi-phase transition from base classes to leaf classes. It
 284      * allows a legacy-reset Bus class to extend a multi-phases-reset
 285      * Bus class for the following reason:
 286      * + If a base class B has been moved to multi-phase, then it does not
 287      *   override this default reset method and may have defined phase methods.
 288      * + A child class C (extending class B) which uses
 289      *   bus_class_set_parent_reset() (or similar means) to override the
 290      *   reset method will still work as expected. @bus_phases_reset function
 291      *   will be registered as the parent reset method and effectively call
 292      *   parent reset phases.
 293      */
 294     bc->reset = bus_phases_reset;
 295     rc->get_transitional_function = bus_get_transitional_reset;
 296 }
 297
 298 static void qbus_finalize(Object *obj)
 299 {
 300     BusState *bus = BUS(obj);
 301
 302     g_free(bus->name);
 303 }
 304
 305 static const TypeInfo bus_info = {
 306     .name = TYPE_BUS,
 307     .parent = TYPE_OBJECT,
 308     .instance_size = sizeof(BusState),
 309     .abstract = true,
 310     .class_size = sizeof(BusClass),
 311     .instance_init = qbus_initfn,
 312     .instance_finalize = qbus_finalize,
 313     .class_init = bus_class_init,
 314     .interfaces = (InterfaceInfo[]) {
 315         { TYPE_RESETTABLE_INTERFACE },
 316         { }
 317     },
 318 };
 319
 320 static void bus_register_types(void)
 321 {
 322     type_register_static(&bus_info);
 323 }
 324
 325 type_init(bus_register_types)