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 static GList *pxb_dev_list;
47 
48 #define TYPE_PXB_HOST "pxb-host"
49 
50 static int pxb_bus_num(PCIBus *bus)
51 {
52     PXBDev *pxb = PXB_DEV(bus->parent_dev);
53 
54     return pxb->bus_nr;
55 }
56 
57 static bool pxb_is_root(PCIBus *bus)
58 {
59     return true; /* by definition */
60 }
61 
62 static uint16_t pxb_bus_numa_node(PCIBus *bus)
63 {
64     PXBDev *pxb = PXB_DEV(bus->parent_dev);
65 
66     return pxb->numa_node;
67 }
68 
69 static void pxb_bus_class_init(ObjectClass *class, void *data)
70 {
71     PCIBusClass *pbc = PCI_BUS_CLASS(class);
72 
73     pbc->bus_num = pxb_bus_num;
74     pbc->is_root = pxb_is_root;
75     pbc->numa_node = pxb_bus_numa_node;
76 }
77 
78 static const TypeInfo pxb_bus_info = {
79     .name          = TYPE_PXB_BUS,
80     .parent        = TYPE_PCI_BUS,
81     .instance_size = sizeof(PXBBus),
82     .class_init    = pxb_bus_class_init,
83 };
84 
85 static const char *pxb_host_root_bus_path(PCIHostState *host_bridge,
86                                           PCIBus *rootbus)
87 {
88     PXBBus *bus = PXB_BUS(rootbus);
89 
90     snprintf(bus->bus_path, 8, "0000:%02x", pxb_bus_num(rootbus));
91     return bus->bus_path;
92 }
93 
94 static char *pxb_host_ofw_unit_address(const SysBusDevice *dev)
95 {
96     const PCIHostState *pxb_host;
97     const PCIBus *pxb_bus;
98     const PXBDev *pxb_dev;
99     int position;
100     const DeviceState *pxb_dev_base;
101     const PCIHostState *main_host;
102     const SysBusDevice *main_host_sbd;
103 
104     pxb_host = PCI_HOST_BRIDGE(dev);
105     pxb_bus = pxb_host->bus;
106     pxb_dev = PXB_DEV(pxb_bus->parent_dev);
107     position = g_list_index(pxb_dev_list, pxb_dev);
108     assert(position >= 0);
109 
110     pxb_dev_base = DEVICE(pxb_dev);
111     main_host = PCI_HOST_BRIDGE(pxb_dev_base->parent_bus->parent);
112     main_host_sbd = SYS_BUS_DEVICE(main_host);
113 
114     if (main_host_sbd->num_mmio > 0) {
115         return g_strdup_printf(TARGET_FMT_plx ",%x",
116                                main_host_sbd->mmio[0].addr, position + 1);
117     }
118     if (main_host_sbd->num_pio > 0) {
119         return g_strdup_printf("i%04x,%x",
120                                main_host_sbd->pio[0], position + 1);
121     }
122     return NULL;
123 }
124 
125 static void pxb_host_class_init(ObjectClass *class, void *data)
126 {
127     DeviceClass *dc = DEVICE_CLASS(class);
128     SysBusDeviceClass *sbc = SYS_BUS_DEVICE_CLASS(class);
129     PCIHostBridgeClass *hc = PCI_HOST_BRIDGE_CLASS(class);
130 
131     dc->fw_name = "pci";
132     sbc->explicit_ofw_unit_address = pxb_host_ofw_unit_address;
133     hc->root_bus_path = pxb_host_root_bus_path;
134 }
135 
136 static const TypeInfo pxb_host_info = {
137     .name          = TYPE_PXB_HOST,
138     .parent        = TYPE_PCI_HOST_BRIDGE,
139     .class_init    = pxb_host_class_init,
140 };
141 
142 /*
143  * Registers the PXB bus as a child of the i440fx root bus.
144  *
145  * Returns 0 on successs, -1 if i440fx host was not
146  * found or the bus number is already in use.
147  */
148 static int pxb_register_bus(PCIDevice *dev, PCIBus *pxb_bus)
149 {
150     PCIBus *bus = dev->bus;
151     int pxb_bus_num = pci_bus_num(pxb_bus);
152 
153     if (bus->parent_dev) {
154         error_report("PXB devices can be attached only to root bus.");
155         return -1;
156     }
157 
158     QLIST_FOREACH(bus, &bus->child, sibling) {
159         if (pci_bus_num(bus) == pxb_bus_num) {
160             error_report("Bus %d is already in use.", pxb_bus_num);
161             return -1;
162         }
163     }
164     QLIST_INSERT_HEAD(&dev->bus->child, pxb_bus, sibling);
165 
166     return 0;
167 }
168 
169 static int pxb_map_irq_fn(PCIDevice *pci_dev, int pin)
170 {
171     PCIDevice *pxb = pci_dev->bus->parent_dev;
172 
173     /*
174      * The bios does not index the pxb slot number when
175      * it computes the IRQ because it resides on bus 0
176      * and not on the current bus.
177      * However QEMU routes the irq through bus 0 and adds
178      * the pxb slot to the IRQ computation of the PXB
179      * device.
180      *
181      * Synchronize between bios and QEMU by canceling
182      * pxb's effect.
183      */
184     return pin - PCI_SLOT(pxb->devfn);
185 }
186 
187 static gint pxb_compare(gconstpointer a, gconstpointer b)
188 {
189     const PXBDev *pxb_a = a, *pxb_b = b;
190 
191     return pxb_a->bus_nr < pxb_b->bus_nr ? -1 :
192            pxb_a->bus_nr > pxb_b->bus_nr ?  1 :
193            0;
194 }
195 
196 static int pxb_dev_initfn(PCIDevice *dev)
197 {
198     PXBDev *pxb = PXB_DEV(dev);
199     DeviceState *ds, *bds;
200     PCIBus *bus;
201     const char *dev_name = NULL;
202 
203     if (pxb->numa_node != NUMA_NODE_UNASSIGNED &&
204         pxb->numa_node >= nb_numa_nodes) {
205         error_report("Illegal numa node %d.", pxb->numa_node);
206         return -EINVAL;
207     }
208 
209     if (dev->qdev.id && *dev->qdev.id) {
210         dev_name = dev->qdev.id;
211     }
212 
213     ds = qdev_create(NULL, TYPE_PXB_HOST);
214     bus = pci_bus_new(ds, "pxb-internal", NULL, NULL, 0, TYPE_PXB_BUS);
215 
216     bus->parent_dev = dev;
217     bus->address_space_mem = dev->bus->address_space_mem;
218     bus->address_space_io = dev->bus->address_space_io;
219     bus->map_irq = pxb_map_irq_fn;
220 
221     bds = qdev_create(BUS(bus), "pci-bridge");
222     bds->id = dev_name;
223     qdev_prop_set_uint8(bds, PCI_BRIDGE_DEV_PROP_CHASSIS_NR, pxb->bus_nr);
224     qdev_prop_set_bit(bds, PCI_BRIDGE_DEV_PROP_SHPC, false);
225 
226     PCI_HOST_BRIDGE(ds)->bus = bus;
227 
228     if (pxb_register_bus(dev, bus)) {
229         return -EINVAL;
230     }
231 
232     qdev_init_nofail(ds);
233     qdev_init_nofail(bds);
234 
235     pci_word_test_and_set_mask(dev->config + PCI_STATUS,
236                                PCI_STATUS_66MHZ | PCI_STATUS_FAST_BACK);
237     pci_config_set_class(dev->config, PCI_CLASS_BRIDGE_HOST);
238 
239     pxb_dev_list = g_list_insert_sorted(pxb_dev_list, pxb, pxb_compare);
240     return 0;
241 }
242 
243 static void pxb_dev_exitfn(PCIDevice *pci_dev)
244 {
245     PXBDev *pxb = PXB_DEV(pci_dev);
246 
247     pxb_dev_list = g_list_remove(pxb_dev_list, pxb);
248 }
249 
250 static Property pxb_dev_properties[] = {
251     /* Note: 0 is not a legal a PXB bus number. */
252     DEFINE_PROP_UINT8("bus_nr", PXBDev, bus_nr, 0),
253     DEFINE_PROP_UINT16("numa_node", PXBDev, numa_node, NUMA_NODE_UNASSIGNED),
254     DEFINE_PROP_END_OF_LIST(),
255 };
256 
257 static void pxb_dev_class_init(ObjectClass *klass, void *data)
258 {
259     DeviceClass *dc = DEVICE_CLASS(klass);
260     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
261 
262     k->init = pxb_dev_initfn;
263     k->exit = pxb_dev_exitfn;
264     k->vendor_id = PCI_VENDOR_ID_REDHAT;
265     k->device_id = PCI_DEVICE_ID_REDHAT_PXB;
266     k->class_id = PCI_CLASS_BRIDGE_HOST;
267 
268     dc->desc = "PCI Expander Bridge";
269     dc->props = pxb_dev_properties;
270 }
271 
272 static const TypeInfo pxb_dev_info = {
273     .name          = TYPE_PXB_DEVICE,
274     .parent        = TYPE_PCI_DEVICE,
275     .instance_size = sizeof(PXBDev),
276     .class_init    = pxb_dev_class_init,
277 };
278 
279 static void pxb_register_types(void)
280 {
281     type_register_static(&pxb_bus_info);
282     type_register_static(&pxb_host_info);
283     type_register_static(&pxb_dev_info);
284 }
285 
286 type_init(pxb_register_types)
287