xref: /openbmc/qemu/hw/pci-bridge/pci_expander_bridge.c (revision abb3009baf90e5984ff1c230af0bc92a45e64864)
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/qdev-properties.h"
19 #include "hw/pci/pci_bridge.h"
20 #include "qemu/range.h"
21 #include "qemu/error-report.h"
22 #include "qemu/module.h"
23 #include "sysemu/numa.h"
24 #include "hw/boards.h"
25 #include "qom/object.h"
26 
27 enum BusType { PCI, PCIE, CXL };
28 
29 #define TYPE_PXB_BUS "pxb-bus"
30 typedef struct PXBBus PXBBus;
31 DECLARE_INSTANCE_CHECKER(PXBBus, PXB_BUS,
32                          TYPE_PXB_BUS)
33 
34 #define TYPE_PXB_PCIE_BUS "pxb-pcie-bus"
35 DECLARE_INSTANCE_CHECKER(PXBBus, PXB_PCIE_BUS,
36                          TYPE_PXB_PCIE_BUS)
37 
38 #define TYPE_PXB_CXL_BUS "pxb-cxl-bus"
39 DECLARE_INSTANCE_CHECKER(PXBBus, PXB_CXL_BUS,
40                          TYPE_PXB_CXL_BUS)
41 
42 struct PXBBus {
43     /*< private >*/
44     PCIBus parent_obj;
45     /*< public >*/
46 
47     char bus_path[8];
48 };
49 
50 #define TYPE_PXB_DEVICE "pxb"
51 typedef struct PXBDev PXBDev;
52 DECLARE_INSTANCE_CHECKER(PXBDev, PXB_DEV,
53                          TYPE_PXB_DEVICE)
54 
55 #define TYPE_PXB_PCIE_DEVICE "pxb-pcie"
56 DECLARE_INSTANCE_CHECKER(PXBDev, PXB_PCIE_DEV,
57                          TYPE_PXB_PCIE_DEVICE)
58 
59 struct PXBDev {
60     /*< private >*/
61     PCIDevice parent_obj;
62     /*< public >*/
63 
64     uint8_t bus_nr;
65     uint16_t numa_node;
66     bool bypass_iommu;
67 };
68 
69 static PXBDev *convert_to_pxb(PCIDevice *dev)
70 {
71     return pci_bus_is_express(pci_get_bus(dev))
72         ? PXB_PCIE_DEV(dev) : PXB_DEV(dev);
73 }
74 
75 static GList *pxb_dev_list;
76 
77 #define TYPE_PXB_HOST "pxb-host"
78 
79 static int pxb_bus_num(PCIBus *bus)
80 {
81     PXBDev *pxb = convert_to_pxb(bus->parent_dev);
82 
83     return pxb->bus_nr;
84 }
85 
86 static uint16_t pxb_bus_numa_node(PCIBus *bus)
87 {
88     PXBDev *pxb = convert_to_pxb(bus->parent_dev);
89 
90     return pxb->numa_node;
91 }
92 
93 static void pxb_bus_class_init(ObjectClass *class, void *data)
94 {
95     PCIBusClass *pbc = PCI_BUS_CLASS(class);
96 
97     pbc->bus_num = pxb_bus_num;
98     pbc->numa_node = pxb_bus_numa_node;
99 }
100 
101 static const TypeInfo pxb_bus_info = {
102     .name          = TYPE_PXB_BUS,
103     .parent        = TYPE_PCI_BUS,
104     .instance_size = sizeof(PXBBus),
105     .class_init    = pxb_bus_class_init,
106 };
107 
108 static const TypeInfo pxb_pcie_bus_info = {
109     .name          = TYPE_PXB_PCIE_BUS,
110     .parent        = TYPE_PCIE_BUS,
111     .instance_size = sizeof(PXBBus),
112     .class_init    = pxb_bus_class_init,
113 };
114 
115 static const char *pxb_host_root_bus_path(PCIHostState *host_bridge,
116                                           PCIBus *rootbus)
117 {
118     PXBBus *bus = pci_bus_is_express(rootbus) ?
119                   PXB_PCIE_BUS(rootbus) : PXB_BUS(rootbus);
120 
121     snprintf(bus->bus_path, 8, "0000:%02x", pxb_bus_num(rootbus));
122     return bus->bus_path;
123 }
124 
125 static char *pxb_host_ofw_unit_address(const SysBusDevice *dev)
126 {
127     const PCIHostState *pxb_host;
128     const PCIBus *pxb_bus;
129     const PXBDev *pxb_dev;
130     int position;
131     const DeviceState *pxb_dev_base;
132     const PCIHostState *main_host;
133     const SysBusDevice *main_host_sbd;
134 
135     pxb_host = PCI_HOST_BRIDGE(dev);
136     pxb_bus = pxb_host->bus;
137     pxb_dev = convert_to_pxb(pxb_bus->parent_dev);
138     position = g_list_index(pxb_dev_list, pxb_dev);
139     assert(position >= 0);
140 
141     pxb_dev_base = DEVICE(pxb_dev);
142     main_host = PCI_HOST_BRIDGE(pxb_dev_base->parent_bus->parent);
143     main_host_sbd = SYS_BUS_DEVICE(main_host);
144 
145     if (main_host_sbd->num_mmio > 0) {
146         return g_strdup_printf(TARGET_FMT_plx ",%x",
147                                main_host_sbd->mmio[0].addr, position + 1);
148     }
149     if (main_host_sbd->num_pio > 0) {
150         return g_strdup_printf("i%04x,%x",
151                                main_host_sbd->pio[0], position + 1);
152     }
153     return NULL;
154 }
155 
156 static void pxb_host_class_init(ObjectClass *class, void *data)
157 {
158     DeviceClass *dc = DEVICE_CLASS(class);
159     SysBusDeviceClass *sbc = SYS_BUS_DEVICE_CLASS(class);
160     PCIHostBridgeClass *hc = PCI_HOST_BRIDGE_CLASS(class);
161 
162     dc->fw_name = "pci";
163     /* Reason: Internal part of the pxb/pxb-pcie device, not usable by itself */
164     dc->user_creatable = false;
165     sbc->explicit_ofw_unit_address = pxb_host_ofw_unit_address;
166     hc->root_bus_path = pxb_host_root_bus_path;
167 }
168 
169 static const TypeInfo pxb_host_info = {
170     .name          = TYPE_PXB_HOST,
171     .parent        = TYPE_PCI_HOST_BRIDGE,
172     .class_init    = pxb_host_class_init,
173 };
174 
175 /*
176  * Registers the PXB bus as a child of pci host root bus.
177  */
178 static void pxb_register_bus(PCIDevice *dev, PCIBus *pxb_bus, Error **errp)
179 {
180     PCIBus *bus = pci_get_bus(dev);
181     int pxb_bus_num = pci_bus_num(pxb_bus);
182 
183     if (bus->parent_dev) {
184         error_setg(errp, "PXB devices can be attached only to root bus");
185         return;
186     }
187 
188     QLIST_FOREACH(bus, &bus->child, sibling) {
189         if (pci_bus_num(bus) == pxb_bus_num) {
190             error_setg(errp, "Bus %d is already in use", pxb_bus_num);
191             return;
192         }
193     }
194     QLIST_INSERT_HEAD(&pci_get_bus(dev)->child, pxb_bus, sibling);
195 }
196 
197 static int pxb_map_irq_fn(PCIDevice *pci_dev, int pin)
198 {
199     PCIDevice *pxb = pci_get_bus(pci_dev)->parent_dev;
200 
201     /*
202      * First carry out normal swizzle to handle
203      * multple root ports on a pxb instance.
204      */
205     pin = pci_swizzle_map_irq_fn(pci_dev, pin);
206 
207     /*
208      * The bios does not index the pxb slot number when
209      * it computes the IRQ because it resides on bus 0
210      * and not on the current bus.
211      * However QEMU routes the irq through bus 0 and adds
212      * the pxb slot to the IRQ computation of the PXB
213      * device.
214      *
215      * Synchronize between bios and QEMU by canceling
216      * pxb's effect.
217      */
218     return pin - PCI_SLOT(pxb->devfn);
219 }
220 
221 static gint pxb_compare(gconstpointer a, gconstpointer b)
222 {
223     const PXBDev *pxb_a = a, *pxb_b = b;
224 
225     return pxb_a->bus_nr < pxb_b->bus_nr ? -1 :
226            pxb_a->bus_nr > pxb_b->bus_nr ?  1 :
227            0;
228 }
229 
230 static void pxb_dev_realize_common(PCIDevice *dev, enum BusType type,
231                                    Error **errp)
232 {
233     PXBDev *pxb = convert_to_pxb(dev);
234     DeviceState *ds, *bds = NULL;
235     PCIBus *bus;
236     const char *dev_name = NULL;
237     Error *local_err = NULL;
238     MachineState *ms = MACHINE(qdev_get_machine());
239 
240     if (ms->numa_state == NULL) {
241         error_setg(errp, "NUMA is not supported by this machine-type");
242         return;
243     }
244 
245     if (pxb->numa_node != NUMA_NODE_UNASSIGNED &&
246         pxb->numa_node >= ms->numa_state->num_nodes) {
247         error_setg(errp, "Illegal numa node %d", pxb->numa_node);
248         return;
249     }
250 
251     if (dev->qdev.id && *dev->qdev.id) {
252         dev_name = dev->qdev.id;
253     }
254 
255     ds = qdev_new(TYPE_PXB_HOST);
256     if (type == PCIE) {
257         bus = pci_root_bus_new(ds, dev_name, NULL, NULL, 0, TYPE_PXB_PCIE_BUS);
258     } else if (type == CXL) {
259         bus = pci_root_bus_new(ds, dev_name, NULL, NULL, 0, TYPE_PXB_CXL_BUS);
260         bus->flags |= PCI_BUS_CXL;
261     } else {
262         bus = pci_root_bus_new(ds, "pxb-internal", NULL, NULL, 0, TYPE_PXB_BUS);
263         bds = qdev_new("pci-bridge");
264         bds->id = g_strdup(dev_name);
265         qdev_prop_set_uint8(bds, PCI_BRIDGE_DEV_PROP_CHASSIS_NR, pxb->bus_nr);
266         qdev_prop_set_bit(bds, PCI_BRIDGE_DEV_PROP_SHPC, false);
267     }
268 
269     bus->parent_dev = dev;
270     bus->address_space_mem = pci_get_bus(dev)->address_space_mem;
271     bus->address_space_io = pci_get_bus(dev)->address_space_io;
272     bus->map_irq = pxb_map_irq_fn;
273 
274     PCI_HOST_BRIDGE(ds)->bus = bus;
275     PCI_HOST_BRIDGE(ds)->bypass_iommu = pxb->bypass_iommu;
276 
277     pxb_register_bus(dev, bus, &local_err);
278     if (local_err) {
279         error_propagate(errp, local_err);
280         goto err_register_bus;
281     }
282 
283     sysbus_realize_and_unref(SYS_BUS_DEVICE(ds), &error_fatal);
284     if (bds) {
285         qdev_realize_and_unref(bds, &bus->qbus, &error_fatal);
286     }
287 
288     pci_word_test_and_set_mask(dev->config + PCI_STATUS,
289                                PCI_STATUS_66MHZ | PCI_STATUS_FAST_BACK);
290     pci_config_set_class(dev->config, PCI_CLASS_BRIDGE_HOST);
291 
292     pxb_dev_list = g_list_insert_sorted(pxb_dev_list, pxb, pxb_compare);
293     return;
294 
295 err_register_bus:
296     object_unref(OBJECT(bds));
297     object_unparent(OBJECT(bus));
298     object_unref(OBJECT(ds));
299 }
300 
301 static void pxb_dev_realize(PCIDevice *dev, Error **errp)
302 {
303     if (pci_bus_is_express(pci_get_bus(dev))) {
304         error_setg(errp, "pxb devices cannot reside on a PCIe bus");
305         return;
306     }
307 
308     pxb_dev_realize_common(dev, PCI, errp);
309 }
310 
311 static void pxb_dev_exitfn(PCIDevice *pci_dev)
312 {
313     PXBDev *pxb = convert_to_pxb(pci_dev);
314 
315     pxb_dev_list = g_list_remove(pxb_dev_list, pxb);
316 }
317 
318 static Property pxb_dev_properties[] = {
319     /* Note: 0 is not a legal PXB bus number. */
320     DEFINE_PROP_UINT8("bus_nr", PXBDev, bus_nr, 0),
321     DEFINE_PROP_UINT16("numa_node", PXBDev, numa_node, NUMA_NODE_UNASSIGNED),
322     DEFINE_PROP_BOOL("bypass_iommu", PXBDev, bypass_iommu, false),
323     DEFINE_PROP_END_OF_LIST(),
324 };
325 
326 static void pxb_dev_class_init(ObjectClass *klass, void *data)
327 {
328     DeviceClass *dc = DEVICE_CLASS(klass);
329     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
330 
331     k->realize = pxb_dev_realize;
332     k->exit = pxb_dev_exitfn;
333     k->vendor_id = PCI_VENDOR_ID_REDHAT;
334     k->device_id = PCI_DEVICE_ID_REDHAT_PXB;
335     k->class_id = PCI_CLASS_BRIDGE_HOST;
336 
337     dc->desc = "PCI Expander Bridge";
338     device_class_set_props(dc, pxb_dev_properties);
339     dc->hotpluggable = false;
340     set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
341 }
342 
343 static const TypeInfo pxb_dev_info = {
344     .name          = TYPE_PXB_DEVICE,
345     .parent        = TYPE_PCI_DEVICE,
346     .instance_size = sizeof(PXBDev),
347     .class_init    = pxb_dev_class_init,
348     .interfaces = (InterfaceInfo[]) {
349         { INTERFACE_CONVENTIONAL_PCI_DEVICE },
350         { },
351     },
352 };
353 
354 static void pxb_pcie_dev_realize(PCIDevice *dev, Error **errp)
355 {
356     if (!pci_bus_is_express(pci_get_bus(dev))) {
357         error_setg(errp, "pxb-pcie devices cannot reside on a PCI bus");
358         return;
359     }
360 
361     pxb_dev_realize_common(dev, PCIE, errp);
362 }
363 
364 static void pxb_pcie_dev_class_init(ObjectClass *klass, void *data)
365 {
366     DeviceClass *dc = DEVICE_CLASS(klass);
367     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
368 
369     k->realize = pxb_pcie_dev_realize;
370     k->exit = pxb_dev_exitfn;
371     k->vendor_id = PCI_VENDOR_ID_REDHAT;
372     k->device_id = PCI_DEVICE_ID_REDHAT_PXB_PCIE;
373     k->class_id = PCI_CLASS_BRIDGE_HOST;
374 
375     dc->desc = "PCI Express Expander Bridge";
376     device_class_set_props(dc, pxb_dev_properties);
377     dc->hotpluggable = false;
378     set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
379 }
380 
381 static const TypeInfo pxb_pcie_dev_info = {
382     .name          = TYPE_PXB_PCIE_DEVICE,
383     .parent        = TYPE_PCI_DEVICE,
384     .instance_size = sizeof(PXBDev),
385     .class_init    = pxb_pcie_dev_class_init,
386     .interfaces = (InterfaceInfo[]) {
387         { INTERFACE_CONVENTIONAL_PCI_DEVICE },
388         { },
389     },
390 };
391 
392 static void pxb_register_types(void)
393 {
394     type_register_static(&pxb_bus_info);
395     type_register_static(&pxb_pcie_bus_info);
396     type_register_static(&pxb_host_info);
397     type_register_static(&pxb_dev_info);
398     type_register_static(&pxb_pcie_dev_info);
399 }
400 
401 type_init(pxb_register_types)
402