Merge remote-tracking branch 'remotes/alistair/tags/pull-riscv-to-apply-20220121...
[qemu.git] / 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)