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 "qapi/error.h"
15 #include "hw/pci/pci.h"
16 #include "hw/pci/pci_bus.h"
17 #include "hw/pci/pci_host.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     /* Reason: Internal part of the pxb/pxb-pcie device, not usable by itself */
153     dc->cannot_instantiate_with_device_add_yet = true;
154     sbc->explicit_ofw_unit_address = pxb_host_ofw_unit_address;
155     hc->root_bus_path = pxb_host_root_bus_path;
156 }
157 
158 static const TypeInfo pxb_host_info = {
159     .name          = TYPE_PXB_HOST,
160     .parent        = TYPE_PCI_HOST_BRIDGE,
161     .class_init    = pxb_host_class_init,
162 };
163 
164 /*
165  * Registers the PXB bus as a child of pci host root bus.
166  */
167 static void pxb_register_bus(PCIDevice *dev, PCIBus *pxb_bus, Error **errp)
168 {
169     PCIBus *bus = dev->bus;
170     int pxb_bus_num = pci_bus_num(pxb_bus);
171 
172     if (bus->parent_dev) {
173         error_setg(errp, "PXB devices can be attached only to root bus");
174         return;
175     }
176 
177     QLIST_FOREACH(bus, &bus->child, sibling) {
178         if (pci_bus_num(bus) == pxb_bus_num) {
179             error_setg(errp, "Bus %d is already in use", pxb_bus_num);
180             return;
181         }
182     }
183     QLIST_INSERT_HEAD(&dev->bus->child, pxb_bus, sibling);
184 }
185 
186 static int pxb_map_irq_fn(PCIDevice *pci_dev, int pin)
187 {
188     PCIDevice *pxb = pci_dev->bus->parent_dev;
189 
190     /*
191      * The bios does not index the pxb slot number when
192      * it computes the IRQ because it resides on bus 0
193      * and not on the current bus.
194      * However QEMU routes the irq through bus 0 and adds
195      * the pxb slot to the IRQ computation of the PXB
196      * device.
197      *
198      * Synchronize between bios and QEMU by canceling
199      * pxb's effect.
200      */
201     return pin - PCI_SLOT(pxb->devfn);
202 }
203 
204 static gint pxb_compare(gconstpointer a, gconstpointer b)
205 {
206     const PXBDev *pxb_a = a, *pxb_b = b;
207 
208     return pxb_a->bus_nr < pxb_b->bus_nr ? -1 :
209            pxb_a->bus_nr > pxb_b->bus_nr ?  1 :
210            0;
211 }
212 
213 static void pxb_dev_realize_common(PCIDevice *dev, bool pcie, Error **errp)
214 {
215     PXBDev *pxb = convert_to_pxb(dev);
216     DeviceState *ds, *bds = NULL;
217     PCIBus *bus;
218     const char *dev_name = NULL;
219     Error *local_err = NULL;
220 
221     if (pxb->numa_node != NUMA_NODE_UNASSIGNED &&
222         pxb->numa_node >= nb_numa_nodes) {
223         error_setg(errp, "Illegal numa node %d", pxb->numa_node);
224         return;
225     }
226 
227     if (dev->qdev.id && *dev->qdev.id) {
228         dev_name = dev->qdev.id;
229     }
230 
231     ds = qdev_create(NULL, TYPE_PXB_HOST);
232     if (pcie) {
233         bus = pci_bus_new(ds, dev_name, NULL, NULL, 0, TYPE_PXB_PCIE_BUS);
234     } else {
235         bus = pci_bus_new(ds, "pxb-internal", NULL, NULL, 0, TYPE_PXB_BUS);
236         bds = qdev_create(BUS(bus), "pci-bridge");
237         bds->id = dev_name;
238         qdev_prop_set_uint8(bds, PCI_BRIDGE_DEV_PROP_CHASSIS_NR, pxb->bus_nr);
239         qdev_prop_set_bit(bds, PCI_BRIDGE_DEV_PROP_SHPC, false);
240     }
241 
242     bus->parent_dev = dev;
243     bus->address_space_mem = dev->bus->address_space_mem;
244     bus->address_space_io = dev->bus->address_space_io;
245     bus->map_irq = pxb_map_irq_fn;
246 
247     PCI_HOST_BRIDGE(ds)->bus = bus;
248 
249     pxb_register_bus(dev, bus, &local_err);
250     if (local_err) {
251         error_propagate(errp, local_err);
252         goto err_register_bus;
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;
266 
267 err_register_bus:
268     object_unref(OBJECT(bds));
269     object_unparent(OBJECT(bus));
270     object_unref(OBJECT(ds));
271 }
272 
273 static void pxb_dev_realize(PCIDevice *dev, Error **errp)
274 {
275     if (pci_bus_is_express(dev->bus)) {
276         error_setg(errp, "pxb devices cannot reside on a PCIe bus");
277         return;
278     }
279 
280     pxb_dev_realize_common(dev, false, errp);
281 }
282 
283 static void pxb_dev_exitfn(PCIDevice *pci_dev)
284 {
285     PXBDev *pxb = convert_to_pxb(pci_dev);
286 
287     pxb_dev_list = g_list_remove(pxb_dev_list, pxb);
288 }
289 
290 static Property pxb_dev_properties[] = {
291     /* Note: 0 is not a legal PXB bus number. */
292     DEFINE_PROP_UINT8("bus_nr", PXBDev, bus_nr, 0),
293     DEFINE_PROP_UINT16("numa_node", PXBDev, numa_node, NUMA_NODE_UNASSIGNED),
294     DEFINE_PROP_END_OF_LIST(),
295 };
296 
297 static void pxb_dev_class_init(ObjectClass *klass, void *data)
298 {
299     DeviceClass *dc = DEVICE_CLASS(klass);
300     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
301 
302     k->realize = pxb_dev_realize;
303     k->exit = pxb_dev_exitfn;
304     k->vendor_id = PCI_VENDOR_ID_REDHAT;
305     k->device_id = PCI_DEVICE_ID_REDHAT_PXB;
306     k->class_id = PCI_CLASS_BRIDGE_HOST;
307 
308     dc->desc = "PCI Expander Bridge";
309     dc->props = pxb_dev_properties;
310     dc->hotpluggable = false;
311     set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
312 }
313 
314 static const TypeInfo pxb_dev_info = {
315     .name          = TYPE_PXB_DEVICE,
316     .parent        = TYPE_PCI_DEVICE,
317     .instance_size = sizeof(PXBDev),
318     .class_init    = pxb_dev_class_init,
319 };
320 
321 static void pxb_pcie_dev_realize(PCIDevice *dev, Error **errp)
322 {
323     if (!pci_bus_is_express(dev->bus)) {
324         error_setg(errp, "pxb-pcie devices cannot reside on a PCI bus");
325         return;
326     }
327 
328     pxb_dev_realize_common(dev, true, errp);
329 }
330 
331 static void pxb_pcie_dev_class_init(ObjectClass *klass, void *data)
332 {
333     DeviceClass *dc = DEVICE_CLASS(klass);
334     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
335 
336     k->realize = pxb_pcie_dev_realize;
337     k->exit = pxb_dev_exitfn;
338     k->vendor_id = PCI_VENDOR_ID_REDHAT;
339     k->device_id = PCI_DEVICE_ID_REDHAT_PXB_PCIE;
340     k->class_id = PCI_CLASS_BRIDGE_HOST;
341 
342     dc->desc = "PCI Express Expander Bridge";
343     dc->props = pxb_dev_properties;
344     dc->hotpluggable = false;
345     set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
346 }
347 
348 static const TypeInfo pxb_pcie_dev_info = {
349     .name          = TYPE_PXB_PCIE_DEVICE,
350     .parent        = TYPE_PCI_DEVICE,
351     .instance_size = sizeof(PXBDev),
352     .class_init    = pxb_pcie_dev_class_init,
353 };
354 
355 static void pxb_register_types(void)
356 {
357     type_register_static(&pxb_bus_info);
358     type_register_static(&pxb_pcie_bus_info);
359     type_register_static(&pxb_host_info);
360     type_register_static(&pxb_dev_info);
361     type_register_static(&pxb_pcie_dev_info);
362 }
363 
364 type_init(pxb_register_types)
365