xref: /openbmc/qemu/hw/pci-bridge/pci_bridge_dev.c (revision fcf5ef2a)
1 /*
2  * Standard PCI Bridge Device
3  *
4  * Copyright (c) 2011 Red Hat Inc. Author: Michael S. Tsirkin <mst@redhat.com>
5  *
6  * http://www.pcisig.com/specifications/conventional/pci_to_pci_bridge_architecture/
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License along
19  * with this program; if not, see <http://www.gnu.org/licenses/>.
20  */
21 
22 #include "qemu/osdep.h"
23 #include "qapi/error.h"
24 #include "hw/pci/pci_bridge.h"
25 #include "hw/pci/pci_ids.h"
26 #include "hw/pci/msi.h"
27 #include "hw/pci/shpc.h"
28 #include "hw/pci/slotid_cap.h"
29 #include "exec/memory.h"
30 #include "hw/pci/pci_bus.h"
31 #include "hw/hotplug.h"
32 
33 #define TYPE_PCI_BRIDGE_DEV      "pci-bridge"
34 #define TYPE_PCI_BRIDGE_SEAT_DEV "pci-bridge-seat"
35 #define PCI_BRIDGE_DEV(obj) \
36     OBJECT_CHECK(PCIBridgeDev, (obj), TYPE_PCI_BRIDGE_DEV)
37 
38 struct PCIBridgeDev {
39     /*< private >*/
40     PCIBridge parent_obj;
41     /*< public >*/
42 
43     MemoryRegion bar;
44     uint8_t chassis_nr;
45 #define PCI_BRIDGE_DEV_F_SHPC_REQ 0
46     uint32_t flags;
47 
48     OnOffAuto msi;
49 };
50 typedef struct PCIBridgeDev PCIBridgeDev;
51 
52 static int pci_bridge_dev_initfn(PCIDevice *dev)
53 {
54     PCIBridge *br = PCI_BRIDGE(dev);
55     PCIBridgeDev *bridge_dev = PCI_BRIDGE_DEV(dev);
56     int err;
57     Error *local_err = NULL;
58 
59     pci_bridge_initfn(dev, TYPE_PCI_BUS);
60 
61     if (bridge_dev->flags & (1 << PCI_BRIDGE_DEV_F_SHPC_REQ)) {
62         dev->config[PCI_INTERRUPT_PIN] = 0x1;
63         memory_region_init(&bridge_dev->bar, OBJECT(dev), "shpc-bar",
64                            shpc_bar_size(dev));
65         err = shpc_init(dev, &br->sec_bus, &bridge_dev->bar, 0);
66         if (err) {
67             goto shpc_error;
68         }
69     } else {
70         /* MSI is not applicable without SHPC */
71         bridge_dev->msi = ON_OFF_AUTO_OFF;
72     }
73 
74     err = slotid_cap_init(dev, 0, bridge_dev->chassis_nr, 0);
75     if (err) {
76         goto slotid_error;
77     }
78 
79     if (bridge_dev->msi != ON_OFF_AUTO_OFF) {
80         /* it means SHPC exists, because MSI is needed by SHPC */
81 
82         err = msi_init(dev, 0, 1, true, true, &local_err);
83         /* Any error other than -ENOTSUP(board's MSI support is broken)
84          * is a programming error */
85         assert(!err || err == -ENOTSUP);
86         if (err && bridge_dev->msi == ON_OFF_AUTO_ON) {
87             /* Can't satisfy user's explicit msi=on request, fail */
88             error_append_hint(&local_err, "You have to use msi=auto (default) "
89                     "or msi=off with this machine type.\n");
90             error_report_err(local_err);
91             goto msi_error;
92         }
93         assert(!local_err || bridge_dev->msi == ON_OFF_AUTO_AUTO);
94         /* With msi=auto, we fall back to MSI off silently */
95         error_free(local_err);
96     }
97 
98     if (shpc_present(dev)) {
99         /* TODO: spec recommends using 64 bit prefetcheable BAR.
100          * Check whether that works well. */
101         pci_register_bar(dev, 0, PCI_BASE_ADDRESS_SPACE_MEMORY |
102                          PCI_BASE_ADDRESS_MEM_TYPE_64, &bridge_dev->bar);
103     }
104     return 0;
105 
106 msi_error:
107     slotid_cap_cleanup(dev);
108 slotid_error:
109     if (shpc_present(dev)) {
110         shpc_cleanup(dev, &bridge_dev->bar);
111     }
112 shpc_error:
113     pci_bridge_exitfn(dev);
114 
115     return err;
116 }
117 
118 static void pci_bridge_dev_exitfn(PCIDevice *dev)
119 {
120     PCIBridgeDev *bridge_dev = PCI_BRIDGE_DEV(dev);
121     if (msi_present(dev)) {
122         msi_uninit(dev);
123     }
124     slotid_cap_cleanup(dev);
125     if (shpc_present(dev)) {
126         shpc_cleanup(dev, &bridge_dev->bar);
127     }
128     pci_bridge_exitfn(dev);
129 }
130 
131 static void pci_bridge_dev_instance_finalize(Object *obj)
132 {
133     /* this function is idempotent and handles (PCIDevice.shpc == NULL) */
134     shpc_free(PCI_DEVICE(obj));
135 }
136 
137 static void pci_bridge_dev_write_config(PCIDevice *d,
138                                         uint32_t address, uint32_t val, int len)
139 {
140     pci_bridge_write_config(d, address, val, len);
141     if (msi_present(d)) {
142         msi_write_config(d, address, val, len);
143     }
144     if (shpc_present(d)) {
145         shpc_cap_write_config(d, address, val, len);
146     }
147 }
148 
149 static void qdev_pci_bridge_dev_reset(DeviceState *qdev)
150 {
151     PCIDevice *dev = PCI_DEVICE(qdev);
152 
153     pci_bridge_reset(qdev);
154     if (shpc_present(dev)) {
155         shpc_reset(dev);
156     }
157 }
158 
159 static Property pci_bridge_dev_properties[] = {
160                     /* Note: 0 is not a legal chassis number. */
161     DEFINE_PROP_UINT8(PCI_BRIDGE_DEV_PROP_CHASSIS_NR, PCIBridgeDev, chassis_nr,
162                       0),
163     DEFINE_PROP_ON_OFF_AUTO(PCI_BRIDGE_DEV_PROP_MSI, PCIBridgeDev, msi,
164                             ON_OFF_AUTO_AUTO),
165     DEFINE_PROP_BIT(PCI_BRIDGE_DEV_PROP_SHPC, PCIBridgeDev, flags,
166                     PCI_BRIDGE_DEV_F_SHPC_REQ, true),
167     DEFINE_PROP_END_OF_LIST(),
168 };
169 
170 static bool pci_device_shpc_present(void *opaque, int version_id)
171 {
172     PCIDevice *dev = opaque;
173 
174     return shpc_present(dev);
175 }
176 
177 static const VMStateDescription pci_bridge_dev_vmstate = {
178     .name = "pci_bridge",
179     .fields = (VMStateField[]) {
180         VMSTATE_PCI_DEVICE(parent_obj, PCIBridge),
181         SHPC_VMSTATE(shpc, PCIDevice, pci_device_shpc_present),
182         VMSTATE_END_OF_LIST()
183     }
184 };
185 
186 static void pci_bridge_dev_hotplug_cb(HotplugHandler *hotplug_dev,
187                                       DeviceState *dev, Error **errp)
188 {
189     PCIDevice *pci_hotplug_dev = PCI_DEVICE(hotplug_dev);
190 
191     if (!shpc_present(pci_hotplug_dev)) {
192         error_setg(errp, "standard hotplug controller has been disabled for "
193                    "this %s", TYPE_PCI_BRIDGE_DEV);
194         return;
195     }
196     shpc_device_hotplug_cb(hotplug_dev, dev, errp);
197 }
198 
199 static void pci_bridge_dev_hot_unplug_request_cb(HotplugHandler *hotplug_dev,
200                                                  DeviceState *dev,
201                                                  Error **errp)
202 {
203     PCIDevice *pci_hotplug_dev = PCI_DEVICE(hotplug_dev);
204 
205     if (!shpc_present(pci_hotplug_dev)) {
206         error_setg(errp, "standard hotplug controller has been disabled for "
207                    "this %s", TYPE_PCI_BRIDGE_DEV);
208         return;
209     }
210     shpc_device_hot_unplug_request_cb(hotplug_dev, dev, errp);
211 }
212 
213 static void pci_bridge_dev_class_init(ObjectClass *klass, void *data)
214 {
215     DeviceClass *dc = DEVICE_CLASS(klass);
216     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
217     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
218 
219     k->init = pci_bridge_dev_initfn;
220     k->exit = pci_bridge_dev_exitfn;
221     k->config_write = pci_bridge_dev_write_config;
222     k->vendor_id = PCI_VENDOR_ID_REDHAT;
223     k->device_id = PCI_DEVICE_ID_REDHAT_BRIDGE;
224     k->class_id = PCI_CLASS_BRIDGE_PCI;
225     k->is_bridge = 1,
226     dc->desc = "Standard PCI Bridge";
227     dc->reset = qdev_pci_bridge_dev_reset;
228     dc->props = pci_bridge_dev_properties;
229     dc->vmsd = &pci_bridge_dev_vmstate;
230     set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
231     hc->plug = pci_bridge_dev_hotplug_cb;
232     hc->unplug_request = pci_bridge_dev_hot_unplug_request_cb;
233 }
234 
235 static const TypeInfo pci_bridge_dev_info = {
236     .name              = TYPE_PCI_BRIDGE_DEV,
237     .parent            = TYPE_PCI_BRIDGE,
238     .instance_size     = sizeof(PCIBridgeDev),
239     .class_init        = pci_bridge_dev_class_init,
240     .instance_finalize = pci_bridge_dev_instance_finalize,
241     .interfaces = (InterfaceInfo[]) {
242         { TYPE_HOTPLUG_HANDLER },
243         { }
244     }
245 };
246 
247 /*
248  * Multiseat bridge.  Same as the standard pci bridge, only with a
249  * different pci id, so we can match it easily in the guest for
250  * automagic multiseat configuration.  See docs/multiseat.txt for more.
251  */
252 static void pci_bridge_dev_seat_class_init(ObjectClass *klass, void *data)
253 {
254     DeviceClass *dc = DEVICE_CLASS(klass);
255     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
256 
257     k->device_id = PCI_DEVICE_ID_REDHAT_BRIDGE_SEAT;
258     dc->desc = "Standard PCI Bridge (multiseat)";
259 }
260 
261 static const TypeInfo pci_bridge_dev_seat_info = {
262     .name              = TYPE_PCI_BRIDGE_SEAT_DEV,
263     .parent            = TYPE_PCI_BRIDGE_DEV,
264     .instance_size     = sizeof(PCIBridgeDev),
265     .class_init        = pci_bridge_dev_seat_class_init,
266 };
267 
268 static void pci_bridge_dev_register(void)
269 {
270     type_register_static(&pci_bridge_dev_info);
271     type_register_static(&pci_bridge_dev_seat_info);
272 }
273 
274 type_init(pci_bridge_dev_register);
275