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 2.1 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)
  27 {
  28     object_property_set_link(OBJECT(bus), QDEV_HOTPLUG_HANDLER_PROPERTY,
  29                              handler, &error_abort);
  30 }
  31
  32 void qbus_set_bus_hotplug_handler(BusState *bus)
  33 {
  34     qbus_set_hotplug_handler(bus, OBJECT(bus));
  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     WITH_RCU_READ_LOCK_GUARD() {
  53         QTAILQ_FOREACH_RCU(kid, &bus->children, sibling) {
  54             err = qdev_walk_children(kid->child,
  55                                      pre_devfn, pre_busfn,
  56                                      post_devfn, post_busfn, opaque);
  57             if (err < 0) {
  58                 return err;
  59             }
  60         }
  61     }
  62
  63     if (post_busfn) {
  64         err = post_busfn(bus, opaque);
  65         if (err) {
  66             return err;
  67         }
  68     }
  69
  70     return 0;
  71 }
  72
  73 void bus_cold_reset(BusState *bus)
  74 {
  75     resettable_reset(OBJECT(bus), RESET_TYPE_COLD);
  76 }
  77
  78 bool bus_is_in_reset(BusState *bus)
  79 {
  80     return resettable_is_in_reset(OBJECT(bus));
  81 }
  82
  83 static ResettableState *bus_get_reset_state(Object *obj)
  84 {
  85     BusState *bus = BUS(obj);
  86     return &bus->reset;
  87 }
  88
  89 static void bus_reset_child_foreach(Object *obj, ResettableChildCallback cb,
  90                                     void *opaque, ResetType type)
  91 {
  92     BusState *bus = BUS(obj);
  93     BusChild *kid;
  94
  95     WITH_RCU_READ_LOCK_GUARD() {
  96         QTAILQ_FOREACH_RCU(kid, &bus->children, sibling) {
  97             cb(OBJECT(kid->child), opaque, type);
  98         }
  99     }
 100 }
 101
 102 static void qbus_init(BusState *bus, DeviceState *parent, const char *name)
 103 {
 104     const char *typename = object_get_typename(OBJECT(bus));
 105     BusClass *bc;
 106     int i, bus_id;
 107
 108     bus->parent = parent;
 109
 110     if (name) {
 111         bus->name = g_strdup(name);
 112     } else if (bus->parent && bus->parent->id) {
 113         /* parent device has id -> use it plus parent-bus-id for bus name */
 114         bus_id = bus->parent->num_child_bus;
 115         bus->name = g_strdup_printf("%s.%d", bus->parent->id, bus_id);
 116     } else {
 117         /* no id -> use lowercase bus type plus global bus-id for bus name */
 118         bc = BUS_GET_CLASS(bus);
 119         bus_id = bc->automatic_ids++;
 120         bus->name = g_strdup_printf("%s.%d", typename, bus_id);
 121         for (i = 0; bus->name[i]; i++) {
 122             bus->name[i] = qemu_tolower(bus->name[i]);
 123         }
 124     }
 125
 126     if (bus->parent) {
 127         QLIST_INSERT_HEAD(&bus->parent->child_bus, bus, sibling);
 128         bus->parent->num_child_bus++;
 129         object_property_add_child(OBJECT(bus->parent), bus->name, OBJECT(bus));
 130         object_unref(OBJECT(bus));
 131     } else {
 132         /* The only bus without a parent is the main system bus */
 133         assert(bus == sysbus_get_default());
 134     }
 135 }
 136
 137 static void bus_unparent(Object *obj)
 138 {
 139     BusState *bus = BUS(obj);
 140     BusChild *kid;
 141
 142     /* Only the main system bus has no parent, and that bus is never freed */
 143     assert(bus->parent);
 144
 145     while ((kid = QTAILQ_FIRST(&bus->children)) != NULL) {
 146         DeviceState *dev = kid->child;
 147         object_unparent(OBJECT(dev));
 148     }
 149     QLIST_REMOVE(bus, sibling);
 150     bus->parent->num_child_bus--;
 151     bus->parent = NULL;
 152 }
 153
 154 void qbus_create_inplace(void *bus, size_t size, const char *typename,
 155                          DeviceState *parent, const char *name)
 156 {
 157     object_initialize(bus, size, typename);
 158     qbus_init(bus, parent, name);
 159 }
 160
 161 BusState *qbus_create(const char *typename, DeviceState *parent, const char *name)
 162 {
 163     BusState *bus;
 164
 165     bus = BUS(object_new(typename));
 166     qbus_init(bus, parent, name);
 167
 168     return bus;
 169 }
 170
 171 bool qbus_realize(BusState *bus, Error **errp)
 172 {
 173     return object_property_set_bool(OBJECT(bus), "realized", true, errp);
 174 }
 175
 176 void qbus_unrealize(BusState *bus)
 177 {
 178     object_property_set_bool(OBJECT(bus), "realized", false, &error_abort);
 179 }
 180
 181 static bool bus_get_realized(Object *obj, Error **errp)
 182 {
 183     BusState *bus = BUS(obj);
 184
 185     return bus->realized;
 186 }
 187
 188 static void bus_set_realized(Object *obj, bool value, Error **errp)
 189 {
 190     BusState *bus = BUS(obj);
 191     BusClass *bc = BUS_GET_CLASS(bus);
 192     BusChild *kid;
 193
 194     if (value && !bus->realized) {
 195         if (bc->realize) {
 196             bc->realize(bus, errp);
 197         }
 198
 199         /* TODO: recursive realization */
 200     } else if (!value && bus->realized) {
 201         WITH_RCU_READ_LOCK_GUARD() {
 202             QTAILQ_FOREACH_RCU(kid, &bus->children, sibling) {
 203                 DeviceState *dev = kid->child;
 204                 qdev_unrealize(dev);
 205             }
 206         }
 207         if (bc->unrealize) {
 208             bc->unrealize(bus);
 209         }
 210     }
 211
 212     bus->realized = value;
 213 }
 214
 215 static void qbus_initfn(Object *obj)
 216 {
 217     BusState *bus = BUS(obj);
 218
 219     QTAILQ_INIT(&bus->children);
 220     object_property_add_link(obj, QDEV_HOTPLUG_HANDLER_PROPERTY,
 221                              TYPE_HOTPLUG_HANDLER,
 222                              (Object **)&bus->hotplug_handler,
 223                              object_property_allow_set_link,
 224                              0);
 225     object_property_add_bool(obj, "realized",
 226                              bus_get_realized, bus_set_realized);
 227 }
 228
 229 static char *default_bus_get_fw_dev_path(DeviceState *dev)
 230 {
 231     return g_strdup(object_get_typename(OBJECT(dev)));
 232 }
 233
 234 /**
 235  * bus_phases_reset:
 236  * Transition reset method for buses to allow moving
 237  * smoothly from legacy reset method to multi-phases
 238  */
 239 static void bus_phases_reset(BusState *bus)
 240 {
 241     ResettableClass *rc = RESETTABLE_GET_CLASS(bus);
 242
 243     if (rc->phases.enter) {
 244         rc->phases.enter(OBJECT(bus), RESET_TYPE_COLD);
 245     }
 246     if (rc->phases.hold) {
 247         rc->phases.hold(OBJECT(bus));
 248     }
 249     if (rc->phases.exit) {
 250         rc->phases.exit(OBJECT(bus));
 251     }
 252 }
 253
 254 static void bus_transitional_reset(Object *obj)
 255 {
 256     BusClass *bc = BUS_GET_CLASS(obj);
 257
 258     /*
 259      * This will call either @bus_phases_reset (for multi-phases transitioned
 260      * buses) or a bus's specific method for not-yet transitioned buses.
 261      * In both case, it does not reset children.
 262      */
 263     if (bc->reset) {
 264         bc->reset(BUS(obj));
 265     }
 266 }
 267
 268 /**
 269  * bus_get_transitional_reset:
 270  * check if the bus's class is ready for multi-phase
 271  */
 272 static ResettableTrFunction bus_get_transitional_reset(Object *obj)
 273 {
 274     BusClass *dc = BUS_GET_CLASS(obj);
 275     if (dc->reset != bus_phases_reset) {
 276         /*
 277          * dc->reset has been overridden by a subclass,
 278          * the bus is not ready for multi phase yet.
 279          */
 280         return bus_transitional_reset;
 281     }
 282     return NULL;
 283 }
 284
 285 static void bus_class_init(ObjectClass *class, void *data)
 286 {
 287     BusClass *bc = BUS_CLASS(class);
 288     ResettableClass *rc = RESETTABLE_CLASS(class);
 289
 290     class->unparent = bus_unparent;
 291     bc->get_fw_dev_path = default_bus_get_fw_dev_path;
 292
 293     rc->get_state = bus_get_reset_state;
 294     rc->child_foreach = bus_reset_child_foreach;
 295
 296     /*
 297      * @bus_phases_reset is put as the default reset method below, allowing
 298      * to do the multi-phase transition from base classes to leaf classes. It
 299      * allows a legacy-reset Bus class to extend a multi-phases-reset
 300      * Bus class for the following reason:
 301      * + If a base class B has been moved to multi-phase, then it does not
 302      *   override this default reset method and may have defined phase methods.
 303      * + A child class C (extending class B) which uses
 304      *   bus_class_set_parent_reset() (or similar means) to override the
 305      *   reset method will still work as expected. @bus_phases_reset function
 306      *   will be registered as the parent reset method and effectively call
 307      *   parent reset phases.
 308      */
 309     bc->reset = bus_phases_reset;
 310     rc->get_transitional_function = bus_get_transitional_reset;
 311 }
 312
 313 static void qbus_finalize(Object *obj)
 314 {
 315     BusState *bus = BUS(obj);
 316
 317     g_free(bus->name);
 318 }
 319
 320 static const TypeInfo bus_info = {
 321     .name = TYPE_BUS,
 322     .parent = TYPE_OBJECT,
 323     .instance_size = sizeof(BusState),
 324     .abstract = true,
 325     .class_size = sizeof(BusClass),
 326     .instance_init = qbus_initfn,
 327     .instance_finalize = qbus_finalize,
 328     .class_init = bus_class_init,
 329     .interfaces = (InterfaceInfo[]) {
 330         { TYPE_RESETTABLE_INTERFACE },
 331         { }
 332     },
 333 };
 334
 335 static void bus_register_types(void)
 336 {
 337     type_register_static(&bus_info);
 338 }
 339
 340 type_init(bus_register_types)