xref: /openbmc/qemu/hw/s390x/ap-bridge.c (revision 65a117da)
1 /*
2  * ap bridge
3  *
4  * Copyright 2018 IBM Corp.
5  *
6  * This work is licensed under the terms of the GNU GPL, version 2 or (at
7  * your option) any later version. See the COPYING file in the top-level
8  * directory.
9  */
10 
11 #include "qemu/osdep.h"
12 #include "qapi/error.h"
13 #include "hw/sysbus.h"
14 #include "qemu/bitops.h"
15 #include "qemu/module.h"
16 #include "hw/s390x/ap-bridge.h"
17 #include "cpu.h"
18 
19 static char *ap_bus_get_dev_path(DeviceState *dev)
20 {
21     /* at most one */
22     return g_strdup_printf("/1");
23 }
24 
25 static void ap_bus_class_init(ObjectClass *oc, void *data)
26 {
27     BusClass *k = BUS_CLASS(oc);
28 
29     k->get_dev_path = ap_bus_get_dev_path;
30     /* More than one ap device does not make sense */
31     k->max_dev = 1;
32 }
33 
34 static const TypeInfo ap_bus_info = {
35     .name = TYPE_AP_BUS,
36     .parent = TYPE_BUS,
37     .instance_size = 0,
38     .class_init = ap_bus_class_init,
39 };
40 
41 void s390_init_ap(void)
42 {
43     DeviceState *dev;
44     BusState *bus;
45 
46     /* If no AP instructions then no need for AP bridge */
47     if (!s390_has_feat(S390_FEAT_AP)) {
48         return;
49     }
50 
51     /* Create bridge device */
52     dev = qdev_create(NULL, TYPE_AP_BRIDGE);
53     object_property_add_child(qdev_get_machine(), TYPE_AP_BRIDGE,
54                               OBJECT(dev));
55     qdev_init_nofail(dev);
56 
57     /* Create bus on bridge device */
58     bus = qbus_create(TYPE_AP_BUS, dev, TYPE_AP_BUS);
59 
60     /* Enable hotplugging */
61     qbus_set_hotplug_handler(bus, OBJECT(dev), &error_abort);
62  }
63 
64 static void ap_bridge_class_init(ObjectClass *oc, void *data)
65 {
66     DeviceClass *dc = DEVICE_CLASS(oc);
67     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(oc);
68 
69     hc->unplug = qdev_simple_device_unplug_cb;
70     set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
71 }
72 
73 static const TypeInfo ap_bridge_info = {
74     .name          = TYPE_AP_BRIDGE,
75     .parent        = TYPE_SYS_BUS_DEVICE,
76     .instance_size = 0,
77     .class_init    = ap_bridge_class_init,
78     .interfaces = (InterfaceInfo[]) {
79         { TYPE_HOTPLUG_HANDLER },
80         { }
81     }
82 };
83 
84 static void ap_register(void)
85 {
86     type_register_static(&ap_bridge_info);
87     type_register_static(&ap_bus_info);
88 }
89 
90 type_init(ap_register)
91