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