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 "qemu/osdep.h"
14 #include "hw/pci/pci.h"
15 #include "hw/pci/pci_bus.h"
16 #include "hw/pci/pci_host.h"
17 #include "hw/pci/pci_bus.h"
18 #include "hw/pci/pci_bridge.h"
19 #include "hw/i386/pc.h"
20 #include "qemu/range.h"
21 #include "qemu/error-report.h"
22 #include "sysemu/numa.h"
23 
24 #define TYPE_PXB_BUS "pxb-bus"
25 #define PXB_BUS(obj) OBJECT_CHECK(PXBBus, (obj), TYPE_PXB_BUS)
26 
27 #define TYPE_PXB_PCIE_BUS "pxb-pcie-bus"
28 #define PXB_PCIE_BUS(obj) OBJECT_CHECK(PXBBus, (obj), TYPE_PXB_PCIE_BUS)
29 
30 typedef struct PXBBus {
31     /*< private >*/
32     PCIBus parent_obj;
33     /*< public >*/
34 
35     char bus_path[8];
36 } PXBBus;
37 
38 #define TYPE_PXB_DEVICE "pxb"
39 #define PXB_DEV(obj) OBJECT_CHECK(PXBDev, (obj), TYPE_PXB_DEVICE)
40 
41 #define TYPE_PXB_PCIE_DEVICE "pxb-pcie"
42 #define PXB_PCIE_DEV(obj) OBJECT_CHECK(PXBDev, (obj), TYPE_PXB_PCIE_DEVICE)
43 
44 typedef struct PXBDev {
45     /*< private >*/
46     PCIDevice parent_obj;
47     /*< public >*/
48 
49     uint8_t bus_nr;
50     uint16_t numa_node;
51 } PXBDev;
52 
53 static PXBDev *convert_to_pxb(PCIDevice *dev)
54 {
55     return pci_bus_is_express(dev->bus) ? PXB_PCIE_DEV(dev) : PXB_DEV(dev);
56 }
57 
58 static GList *pxb_dev_list;
59 
60 #define TYPE_PXB_HOST "pxb-host"
61 
62 static int pxb_bus_num(PCIBus *bus)
63 {
64     PXBDev *pxb = convert_to_pxb(bus->parent_dev);
65 
66     return pxb->bus_nr;
67 }
68 
69 static bool pxb_is_root(PCIBus *bus)
70 {
71     return true; /* by definition */
72 }
73 
74 static uint16_t pxb_bus_numa_node(PCIBus *bus)
75 {
76     PXBDev *pxb = convert_to_pxb(bus->parent_dev);
77 
78     return pxb->numa_node;
79 }
80 
81 static void pxb_bus_class_init(ObjectClass *class, void *data)
82 {
83     PCIBusClass *pbc = PCI_BUS_CLASS(class);
84 
85     pbc->bus_num = pxb_bus_num;
86     pbc->is_root = pxb_is_root;
87     pbc->numa_node = pxb_bus_numa_node;
88 }
89 
90 static const TypeInfo pxb_bus_info = {
91     .name          = TYPE_PXB_BUS,
92     .parent        = TYPE_PCI_BUS,
93     .instance_size = sizeof(PXBBus),
94     .class_init    = pxb_bus_class_init,
95 };
96 
97 static const TypeInfo pxb_pcie_bus_info = {
98     .name          = TYPE_PXB_PCIE_BUS,
99     .parent        = TYPE_PCIE_BUS,
100     .instance_size = sizeof(PXBBus),
101     .class_init    = pxb_bus_class_init,
102 };
103 
104 static const char *pxb_host_root_bus_path(PCIHostState *host_bridge,
105                                           PCIBus *rootbus)
106 {
107     PXBBus *bus = pci_bus_is_express(rootbus) ?
108                   PXB_PCIE_BUS(rootbus) : PXB_BUS(rootbus);
109 
110     snprintf(bus->bus_path, 8, "0000:%02x", pxb_bus_num(rootbus));
111     return bus->bus_path;
112 }
113 
114 static char *pxb_host_ofw_unit_address(const SysBusDevice *dev)
115 {
116     const PCIHostState *pxb_host;
117     const PCIBus *pxb_bus;
118     const PXBDev *pxb_dev;
119     int position;
120     const DeviceState *pxb_dev_base;
121     const PCIHostState *main_host;
122     const SysBusDevice *main_host_sbd;
123 
124     pxb_host = PCI_HOST_BRIDGE(dev);
125     pxb_bus = pxb_host->bus;
126     pxb_dev = convert_to_pxb(pxb_bus->parent_dev);
127     position = g_list_index(pxb_dev_list, pxb_dev);
128     assert(position >= 0);
129 
130     pxb_dev_base = DEVICE(pxb_dev);
131     main_host = PCI_HOST_BRIDGE(pxb_dev_base->parent_bus->parent);
132     main_host_sbd = SYS_BUS_DEVICE(main_host);
133 
134     if (main_host_sbd->num_mmio > 0) {
135         return g_strdup_printf(TARGET_FMT_plx ",%x",
136                                main_host_sbd->mmio[0].addr, position + 1);
137     }
138     if (main_host_sbd->num_pio > 0) {
139         return g_strdup_printf("i%04x,%x",
140                                main_host_sbd->pio[0], position + 1);
141     }
142     return NULL;
143 }
144 
145 static void pxb_host_class_init(ObjectClass *class, void *data)
146 {
147     DeviceClass *dc = DEVICE_CLASS(class);
148     SysBusDeviceClass *sbc = SYS_BUS_DEVICE_CLASS(class);
149     PCIHostBridgeClass *hc = PCI_HOST_BRIDGE_CLASS(class);
150 
151     dc->fw_name = "pci";
152     sbc->explicit_ofw_unit_address = pxb_host_ofw_unit_address;
153     hc->root_bus_path = pxb_host_root_bus_path;
154 }
155 
156 static const TypeInfo pxb_host_info = {
157     .name          = TYPE_PXB_HOST,
158     .parent        = TYPE_PCI_HOST_BRIDGE,
159     .class_init    = pxb_host_class_init,
160 };
161 
162 /*
163  * Registers the PXB bus as a child of the i440fx root bus.
164  *
165  * Returns 0 on successs, -1 if i440fx host was not
166  * found or the bus number is already in use.
167  */
168 static int pxb_register_bus(PCIDevice *dev, PCIBus *pxb_bus)
169 {
170     PCIBus *bus = dev->bus;
171     int pxb_bus_num = pci_bus_num(pxb_bus);
172 
173     if (bus->parent_dev) {
174         error_report("PXB devices can be attached only to root bus.");
175         return -1;
176     }
177 
178     QLIST_FOREACH(bus, &bus->child, sibling) {
179         if (pci_bus_num(bus) == pxb_bus_num) {
180             error_report("Bus %d is already in use.", pxb_bus_num);
181             return -1;
182         }
183     }
184     QLIST_INSERT_HEAD(&dev->bus->child, pxb_bus, sibling);
185 
186     return 0;
187 }
188 
189 static int pxb_map_irq_fn(PCIDevice *pci_dev, int pin)
190 {
191     PCIDevice *pxb = pci_dev->bus->parent_dev;
192 
193     /*
194      * The bios does not index the pxb slot number when
195      * it computes the IRQ because it resides on bus 0
196      * and not on the current bus.
197      * However QEMU routes the irq through bus 0 and adds
198      * the pxb slot to the IRQ computation of the PXB
199      * device.
200      *
201      * Synchronize between bios and QEMU by canceling
202      * pxb's effect.
203      */
204     return pin - PCI_SLOT(pxb->devfn);
205 }
206 
207 static gint pxb_compare(gconstpointer a, gconstpointer b)
208 {
209     const PXBDev *pxb_a = a, *pxb_b = b;
210 
211     return pxb_a->bus_nr < pxb_b->bus_nr ? -1 :
212            pxb_a->bus_nr > pxb_b->bus_nr ?  1 :
213            0;
214 }
215 
216 static int pxb_dev_init_common(PCIDevice *dev, bool pcie)
217 {
218     PXBDev *pxb = convert_to_pxb(dev);
219     DeviceState *ds, *bds = NULL;
220     PCIBus *bus;
221     const char *dev_name = NULL;
222 
223     if (pxb->numa_node != NUMA_NODE_UNASSIGNED &&
224         pxb->numa_node >= nb_numa_nodes) {
225         error_report("Illegal numa node %d.", pxb->numa_node);
226         return -EINVAL;
227     }
228 
229     if (dev->qdev.id && *dev->qdev.id) {
230         dev_name = dev->qdev.id;
231     }
232 
233     ds = qdev_create(NULL, TYPE_PXB_HOST);
234     if (pcie) {
235         bus = pci_bus_new(ds, dev_name, NULL, NULL, 0, TYPE_PXB_PCIE_BUS);
236     } else {
237         bus = pci_bus_new(ds, "pxb-internal", NULL, NULL, 0, TYPE_PXB_BUS);
238         bds = qdev_create(BUS(bus), "pci-bridge");
239         bds->id = dev_name;
240         qdev_prop_set_uint8(bds, PCI_BRIDGE_DEV_PROP_CHASSIS_NR, pxb->bus_nr);
241         qdev_prop_set_bit(bds, PCI_BRIDGE_DEV_PROP_SHPC, false);
242     }
243 
244     bus->parent_dev = dev;
245     bus->address_space_mem = dev->bus->address_space_mem;
246     bus->address_space_io = dev->bus->address_space_io;
247     bus->map_irq = pxb_map_irq_fn;
248 
249     PCI_HOST_BRIDGE(ds)->bus = bus;
250 
251     if (pxb_register_bus(dev, bus)) {
252         return -EINVAL;
253     }
254 
255     qdev_init_nofail(ds);
256     if (bds) {
257         qdev_init_nofail(bds);
258     }
259 
260     pci_word_test_and_set_mask(dev->config + PCI_STATUS,
261                                PCI_STATUS_66MHZ | PCI_STATUS_FAST_BACK);
262     pci_config_set_class(dev->config, PCI_CLASS_BRIDGE_HOST);
263 
264     pxb_dev_list = g_list_insert_sorted(pxb_dev_list, pxb, pxb_compare);
265     return 0;
266 }
267 
268 static int pxb_dev_initfn(PCIDevice *dev)
269 {
270     if (pci_bus_is_express(dev->bus)) {
271         error_report("pxb devices cannot reside on a PCIe bus!");
272         return -EINVAL;
273     }
274 
275     return pxb_dev_init_common(dev, false);
276 }
277 
278 static void pxb_dev_exitfn(PCIDevice *pci_dev)
279 {
280     PXBDev *pxb = convert_to_pxb(pci_dev);
281 
282     pxb_dev_list = g_list_remove(pxb_dev_list, pxb);
283 }
284 
285 static Property pxb_dev_properties[] = {
286     /* Note: 0 is not a legal a PXB bus number. */
287     DEFINE_PROP_UINT8("bus_nr", PXBDev, bus_nr, 0),
288     DEFINE_PROP_UINT16("numa_node", PXBDev, numa_node, NUMA_NODE_UNASSIGNED),
289     DEFINE_PROP_END_OF_LIST(),
290 };
291 
292 static void pxb_dev_class_init(ObjectClass *klass, void *data)
293 {
294     DeviceClass *dc = DEVICE_CLASS(klass);
295     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
296 
297     k->init = pxb_dev_initfn;
298     k->exit = pxb_dev_exitfn;
299     k->vendor_id = PCI_VENDOR_ID_REDHAT;
300     k->device_id = PCI_DEVICE_ID_REDHAT_PXB;
301     k->class_id = PCI_CLASS_BRIDGE_HOST;
302 
303     dc->desc = "PCI Expander Bridge";
304     dc->props = pxb_dev_properties;
305 }
306 
307 static const TypeInfo pxb_dev_info = {
308     .name          = TYPE_PXB_DEVICE,
309     .parent        = TYPE_PCI_DEVICE,
310     .instance_size = sizeof(PXBDev),
311     .class_init    = pxb_dev_class_init,
312 };
313 
314 static int pxb_pcie_dev_initfn(PCIDevice *dev)
315 {
316     if (!pci_bus_is_express(dev->bus)) {
317         error_report("pxb-pcie devices cannot reside on a PCI bus!");
318         return -EINVAL;
319     }
320 
321     return pxb_dev_init_common(dev, true);
322 }
323 
324 static void pxb_pcie_dev_class_init(ObjectClass *klass, void *data)
325 {
326     DeviceClass *dc = DEVICE_CLASS(klass);
327     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
328 
329     k->init = pxb_pcie_dev_initfn;
330     k->exit = pxb_dev_exitfn;
331     k->vendor_id = PCI_VENDOR_ID_REDHAT;
332     k->device_id = PCI_DEVICE_ID_REDHAT_PXB_PCIE;
333     k->class_id = PCI_CLASS_BRIDGE_HOST;
334 
335     dc->desc = "PCI Express Expander Bridge";
336     dc->props = pxb_dev_properties;
337 }
338 
339 static const TypeInfo pxb_pcie_dev_info = {
340     .name          = TYPE_PXB_PCIE_DEVICE,
341     .parent        = TYPE_PCI_DEVICE,
342     .instance_size = sizeof(PXBDev),
343     .class_init    = pxb_pcie_dev_class_init,
344 };
345 
346 static void pxb_register_types(void)
347 {
348     type_register_static(&pxb_bus_info);
349     type_register_static(&pxb_pcie_bus_info);
350     type_register_static(&pxb_host_info);
351     type_register_static(&pxb_dev_info);
352     type_register_static(&pxb_pcie_dev_info);
353 }
354 
355 type_init(pxb_register_types)
356