xref: /openbmc/qemu/hw/pci-bridge/pci_expander_bridge.c (revision 0b336b3b98d8983d821ef9b0f159acc7c77cbac7)
1 /*
2  * PCI Expander Bridge Device Emulation
3  *
4  * Copyright (C) 2015 Red Hat Inc
5  *
6  * Authors:
7  *   Marcel Apfelbaum <marcel@redhat.com>
8  *
9  * This work is licensed under the terms of the GNU GPL, version 2 or later.
10  * See the COPYING file in the top-level directory.
11  */
12 
13 #include "hw/pci/pci.h"
14 #include "hw/pci/pci_bus.h"
15 #include "hw/pci/pci_host.h"
16 #include "hw/pci/pci_bus.h"
17 #include "hw/pci/pci_bridge.h"
18 #include "hw/i386/pc.h"
19 #include "qemu/range.h"
20 #include "qemu/error-report.h"
21 #include "sysemu/numa.h"
22 
23 #define TYPE_PXB_BUS "pxb-bus"
24 #define PXB_BUS(obj) OBJECT_CHECK(PXBBus, (obj), TYPE_PXB_BUS)
25 
26 typedef struct PXBBus {
27     /*< private >*/
28     PCIBus parent_obj;
29     /*< public >*/
30 
31     char bus_path[8];
32 } PXBBus;
33 
34 #define TYPE_PXB_DEVICE "pxb"
35 #define PXB_DEV(obj) OBJECT_CHECK(PXBDev, (obj), TYPE_PXB_DEVICE)
36 
37 typedef struct PXBDev {
38     /*< private >*/
39     PCIDevice parent_obj;
40     /*< public >*/
41 
42     uint8_t bus_nr;
43     uint16_t numa_node;
44 } PXBDev;
45 
46 #define TYPE_PXB_HOST "pxb-host"
47 
48 static int pxb_bus_num(PCIBus *bus)
49 {
50     PXBDev *pxb = PXB_DEV(bus->parent_dev);
51 
52     return pxb->bus_nr;
53 }
54 
55 static bool pxb_is_root(PCIBus *bus)
56 {
57     return true; /* by definition */
58 }
59 
60 static uint16_t pxb_bus_numa_node(PCIBus *bus)
61 {
62     PXBDev *pxb = PXB_DEV(bus->parent_dev);
63 
64     return pxb->numa_node;
65 }
66 
67 static void pxb_bus_class_init(ObjectClass *class, void *data)
68 {
69     PCIBusClass *pbc = PCI_BUS_CLASS(class);
70 
71     pbc->bus_num = pxb_bus_num;
72     pbc->is_root = pxb_is_root;
73     pbc->numa_node = pxb_bus_numa_node;
74 }
75 
76 static const TypeInfo pxb_bus_info = {
77     .name          = TYPE_PXB_BUS,
78     .parent        = TYPE_PCI_BUS,
79     .instance_size = sizeof(PXBBus),
80     .class_init    = pxb_bus_class_init,
81 };
82 
83 static const char *pxb_host_root_bus_path(PCIHostState *host_bridge,
84                                           PCIBus *rootbus)
85 {
86     PXBBus *bus = PXB_BUS(rootbus);
87 
88     snprintf(bus->bus_path, 8, "0000:%02x", pxb_bus_num(rootbus));
89     return bus->bus_path;
90 }
91 
92 static void pxb_host_class_init(ObjectClass *class, void *data)
93 {
94     DeviceClass *dc = DEVICE_CLASS(class);
95     PCIHostBridgeClass *hc = PCI_HOST_BRIDGE_CLASS(class);
96 
97     dc->fw_name = "pci";
98     hc->root_bus_path = pxb_host_root_bus_path;
99 }
100 
101 static const TypeInfo pxb_host_info = {
102     .name          = TYPE_PXB_HOST,
103     .parent        = TYPE_PCI_HOST_BRIDGE,
104     .class_init    = pxb_host_class_init,
105 };
106 
107 /*
108  * Registers the PXB bus as a child of the i440fx root bus.
109  *
110  * Returns 0 on successs, -1 if i440fx host was not
111  * found or the bus number is already in use.
112  */
113 static int pxb_register_bus(PCIDevice *dev, PCIBus *pxb_bus)
114 {
115     PCIBus *bus = dev->bus;
116     int pxb_bus_num = pci_bus_num(pxb_bus);
117 
118     if (bus->parent_dev) {
119         error_report("PXB devices can be attached only to root bus.");
120         return -1;
121     }
122 
123     QLIST_FOREACH(bus, &bus->child, sibling) {
124         if (pci_bus_num(bus) == pxb_bus_num) {
125             error_report("Bus %d is already in use.", pxb_bus_num);
126             return -1;
127         }
128     }
129     QLIST_INSERT_HEAD(&dev->bus->child, pxb_bus, sibling);
130 
131     return 0;
132 }
133 
134 static int pxb_map_irq_fn(PCIDevice *pci_dev, int pin)
135 {
136     PCIDevice *pxb = pci_dev->bus->parent_dev;
137 
138     /*
139      * The bios does not index the pxb slot number when
140      * it computes the IRQ because it resides on bus 0
141      * and not on the current bus.
142      * However QEMU routes the irq through bus 0 and adds
143      * the pxb slot to the IRQ computation of the PXB
144      * device.
145      *
146      * Synchronize between bios and QEMU by canceling
147      * pxb's effect.
148      */
149     return pin - PCI_SLOT(pxb->devfn);
150 }
151 
152 static int pxb_dev_initfn(PCIDevice *dev)
153 {
154     PXBDev *pxb = PXB_DEV(dev);
155     DeviceState *ds, *bds;
156     PCIBus *bus;
157     const char *dev_name = NULL;
158 
159     if (pxb->numa_node != NUMA_NODE_UNASSIGNED &&
160         pxb->numa_node >= nb_numa_nodes) {
161         error_report("Illegal numa node %d.", pxb->numa_node);
162         return -EINVAL;
163     }
164 
165     if (dev->qdev.id && *dev->qdev.id) {
166         dev_name = dev->qdev.id;
167     }
168 
169     ds = qdev_create(NULL, TYPE_PXB_HOST);
170     bus = pci_bus_new(ds, "pxb-internal", NULL, NULL, 0, TYPE_PXB_BUS);
171 
172     bus->parent_dev = dev;
173     bus->address_space_mem = dev->bus->address_space_mem;
174     bus->address_space_io = dev->bus->address_space_io;
175     bus->map_irq = pxb_map_irq_fn;
176 
177     bds = qdev_create(BUS(bus), "pci-bridge");
178     bds->id = dev_name;
179     qdev_prop_set_uint8(bds, PCI_BRIDGE_DEV_PROP_CHASSIS_NR, pxb->bus_nr);
180     qdev_prop_set_bit(bds, PCI_BRIDGE_DEV_PROP_SHPC, false);
181 
182     PCI_HOST_BRIDGE(ds)->bus = bus;
183 
184     if (pxb_register_bus(dev, bus)) {
185         return -EINVAL;
186     }
187 
188     qdev_init_nofail(ds);
189     qdev_init_nofail(bds);
190 
191     pci_word_test_and_set_mask(dev->config + PCI_STATUS,
192                                PCI_STATUS_66MHZ | PCI_STATUS_FAST_BACK);
193     pci_config_set_class(dev->config, PCI_CLASS_BRIDGE_HOST);
194 
195     return 0;
196 }
197 
198 static Property pxb_dev_properties[] = {
199     /* Note: 0 is not a legal a PXB bus number. */
200     DEFINE_PROP_UINT8("bus_nr", PXBDev, bus_nr, 0),
201     DEFINE_PROP_UINT16("numa_node", PXBDev, numa_node, NUMA_NODE_UNASSIGNED),
202     DEFINE_PROP_END_OF_LIST(),
203 };
204 
205 static void pxb_dev_class_init(ObjectClass *klass, void *data)
206 {
207     DeviceClass *dc = DEVICE_CLASS(klass);
208     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
209 
210     k->init = pxb_dev_initfn;
211     k->vendor_id = PCI_VENDOR_ID_REDHAT;
212     k->device_id = PCI_DEVICE_ID_REDHAT_PXB;
213     k->class_id = PCI_CLASS_BRIDGE_HOST;
214 
215     dc->desc = "PCI Expander Bridge";
216     dc->props = pxb_dev_properties;
217 }
218 
219 static const TypeInfo pxb_dev_info = {
220     .name          = TYPE_PXB_DEVICE,
221     .parent        = TYPE_PCI_DEVICE,
222     .instance_size = sizeof(PXBDev),
223     .class_init    = pxb_dev_class_init,
224 };
225 
226 static void pxb_register_types(void)
227 {
228     type_register_static(&pxb_bus_info);
229     type_register_static(&pxb_host_info);
230     type_register_static(&pxb_dev_info);
231 }
232 
233 type_init(pxb_register_types)
234