xref: /openbmc/qemu/hw/s390x/css-bridge.c (revision e09484ef)
1 /*
2  * css bridge implementation
3  *
4  * Copyright 2012,2016 IBM Corp.
5  * Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
6  *            Pierre Morel <pmorel@linux.vnet.ibm.com>
7  *
8  * This work is licensed under the terms of the GNU GPL, version 2 or (at
9  * your option) any later version. See the COPYING file in the top-level
10  * directory.
11  */
12 #include "qemu/osdep.h"
13 #include "qapi/error.h"
14 #include "hw/hotplug.h"
15 #include "hw/sysbus.h"
16 #include "qemu/bitops.h"
17 #include "hw/s390x/css.h"
18 #include "ccw-device.h"
19 #include "hw/s390x/css-bridge.h"
20 
21 /*
22  * Invoke device-specific unplug handler, disable the subchannel
23  * (including sending a channel report to the guest) and remove the
24  * device from the virtual css bus.
25  */
26 static void ccw_device_unplug(HotplugHandler *hotplug_dev,
27                               DeviceState *dev, Error **errp)
28 {
29     CcwDevice *ccw_dev = CCW_DEVICE(dev);
30     CCWDeviceClass *k = CCW_DEVICE_GET_CLASS(ccw_dev);
31     SubchDev *sch = ccw_dev->sch;
32     Error *err = NULL;
33 
34     if (k->unplug) {
35         k->unplug(hotplug_dev, dev, &err);
36         if (err) {
37             error_propagate(errp, err);
38             return;
39         }
40     }
41 
42     /*
43      * We should arrive here only for device_del, since we don't support
44      * direct hot(un)plug of channels.
45      */
46     assert(sch != NULL);
47     /* Subchannel is now disabled and no longer valid. */
48     sch->curr_status.pmcw.flags &= ~(PMCW_FLAGS_MASK_ENA |
49                                      PMCW_FLAGS_MASK_DNV);
50 
51     css_generate_sch_crws(sch->cssid, sch->ssid, sch->schid, 1, 0);
52 
53     object_unparent(OBJECT(dev));
54 }
55 
56 static void virtual_css_bus_reset(BusState *qbus)
57 {
58     /* This should actually be modelled via the generic css */
59     css_reset();
60 }
61 
62 static char *virtual_css_bus_get_dev_path(DeviceState *dev)
63 {
64     CcwDevice *ccw_dev = CCW_DEVICE(dev);
65     SubchDev *sch = ccw_dev->sch;
66     VirtualCssBridge *bridge =
67         VIRTUAL_CSS_BRIDGE(qdev_get_parent_bus(dev)->parent);
68 
69     /*
70      * We can't provide a dev path for backward compatibility on
71      * older machines, as it is visible in the migration stream.
72      */
73     return bridge->css_dev_path ?
74         g_strdup_printf("/%02x.%1x.%04x", sch->cssid, sch->ssid, sch->devno) :
75         NULL;
76 }
77 
78 static void virtual_css_bus_class_init(ObjectClass *klass, void *data)
79 {
80     BusClass *k = BUS_CLASS(klass);
81 
82     k->reset = virtual_css_bus_reset;
83     k->get_dev_path = virtual_css_bus_get_dev_path;
84 }
85 
86 static const TypeInfo virtual_css_bus_info = {
87     .name = TYPE_VIRTUAL_CSS_BUS,
88     .parent = TYPE_BUS,
89     .instance_size = sizeof(VirtualCssBus),
90     .class_init = virtual_css_bus_class_init,
91 };
92 
93 VirtualCssBus *virtual_css_bus_init(void)
94 {
95     VirtualCssBus *cbus;
96     BusState *bus;
97     DeviceState *dev;
98 
99     /* Create bridge device */
100     dev = qdev_create(NULL, TYPE_VIRTUAL_CSS_BRIDGE);
101     qdev_init_nofail(dev);
102 
103     /* Create bus on bridge device */
104     bus = qbus_create(TYPE_VIRTUAL_CSS_BUS, dev, "virtual-css");
105     cbus = VIRTUAL_CSS_BUS(bus);
106 
107     /* Enable hotplugging */
108     qbus_set_hotplug_handler(bus, dev, &error_abort);
109 
110     return cbus;
111  }
112 
113 /***************** Virtual-css Bus Bridge Device ********************/
114 
115 static Property virtual_css_bridge_properties[] = {
116     DEFINE_PROP_BOOL("css_dev_path", VirtualCssBridge, css_dev_path,
117                      true),
118     DEFINE_PROP_END_OF_LIST(),
119 };
120 
121 static void virtual_css_bridge_class_init(ObjectClass *klass, void *data)
122 {
123     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
124     DeviceClass *dc = DEVICE_CLASS(klass);
125 
126     hc->unplug = ccw_device_unplug;
127     set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
128     dc->props = virtual_css_bridge_properties;
129 }
130 
131 static const TypeInfo virtual_css_bridge_info = {
132     .name          = TYPE_VIRTUAL_CSS_BRIDGE,
133     .parent        = TYPE_SYS_BUS_DEVICE,
134     .instance_size = sizeof(VirtualCssBridge),
135     .class_init    = virtual_css_bridge_class_init,
136     .interfaces = (InterfaceInfo[]) {
137         { TYPE_HOTPLUG_HANDLER },
138         { }
139     }
140 };
141 
142 static void virtual_css_register(void)
143 {
144     type_register_static(&virtual_css_bridge_info);
145     type_register_static(&virtual_css_bus_info);
146 }
147 
148 type_init(virtual_css_register)
149