xref: /openbmc/qemu/hw/pci/pci_bridge.c (revision 354908ce)
1 /*
2  * QEMU PCI bus manager
3  *
4  * Copyright (c) 2004 Fabrice Bellard
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to dea
8 
9  * in the Software without restriction, including without limitation the rights
10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11  * copies of the Software, and to permit persons to whom the Software is
12  * furnished to do so, subject to the following conditions:
13  *
14  * The above copyright notice and this permission notice shall be included in
15  * all copies or substantial portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM
22 
23  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
24  * THE SOFTWARE.
25  */
26 /*
27  * split out from pci.c
28  * Copyright (c) 2010 Isaku Yamahata <yamahata at valinux co jp>
29  *                    VA Linux Systems Japan K.K.
30  */
31 
32 #include "qemu/osdep.h"
33 #include "qemu/units.h"
34 #include "hw/pci/pci_bridge.h"
35 #include "hw/pci/pci_bus.h"
36 #include "qemu/module.h"
37 #include "qemu/range.h"
38 #include "qapi/error.h"
39 
40 /* PCI bridge subsystem vendor ID helper functions */
41 #define PCI_SSVID_SIZEOF        8
42 #define PCI_SSVID_SVID          4
43 #define PCI_SSVID_SSID          6
44 
45 int pci_bridge_ssvid_init(PCIDevice *dev, uint8_t offset,
46                           uint16_t svid, uint16_t ssid,
47                           Error **errp)
48 {
49     int pos;
50 
51     pos = pci_add_capability(dev, PCI_CAP_ID_SSVID, offset,
52                              PCI_SSVID_SIZEOF, errp);
53     if (pos < 0) {
54         return pos;
55     }
56 
57     pci_set_word(dev->config + pos + PCI_SSVID_SVID, svid);
58     pci_set_word(dev->config + pos + PCI_SSVID_SSID, ssid);
59     return pos;
60 }
61 
62 /* Accessor function to get parent bridge device from pci bus. */
63 PCIDevice *pci_bridge_get_device(PCIBus *bus)
64 {
65     return bus->parent_dev;
66 }
67 
68 /* Accessor function to get secondary bus from pci-to-pci bridge device */
69 PCIBus *pci_bridge_get_sec_bus(PCIBridge *br)
70 {
71     return &br->sec_bus;
72 }
73 
74 static uint32_t pci_config_get_io_base(const PCIDevice *d,
75                                        uint32_t base, uint32_t base_upper16)
76 {
77     uint32_t val;
78 
79     val = ((uint32_t)d->config[base] & PCI_IO_RANGE_MASK) << 8;
80     if (d->config[base] & PCI_IO_RANGE_TYPE_32) {
81         val |= (uint32_t)pci_get_word(d->config + base_upper16) << 16;
82     }
83     return val;
84 }
85 
86 static pcibus_t pci_config_get_memory_base(const PCIDevice *d, uint32_t base)
87 {
88     return ((pcibus_t)pci_get_word(d->config + base) & PCI_MEMORY_RANGE_MASK)
89         << 16;
90 }
91 
92 static pcibus_t pci_config_get_pref_base(const PCIDevice *d,
93                                          uint32_t base, uint32_t upper)
94 {
95     pcibus_t tmp;
96     pcibus_t val;
97 
98     tmp = (pcibus_t)pci_get_word(d->config + base);
99     val = (tmp & PCI_PREF_RANGE_MASK) << 16;
100     if (tmp & PCI_PREF_RANGE_TYPE_64) {
101         val |= (pcibus_t)pci_get_long(d->config + upper) << 32;
102     }
103     return val;
104 }
105 
106 /* accessor function to get bridge filtering base address */
107 pcibus_t pci_bridge_get_base(const PCIDevice *bridge, uint8_t type)
108 {
109     pcibus_t base;
110     if (type & PCI_BASE_ADDRESS_SPACE_IO) {
111         base = pci_config_get_io_base(bridge,
112                                       PCI_IO_BASE, PCI_IO_BASE_UPPER16);
113     } else {
114         if (type & PCI_BASE_ADDRESS_MEM_PREFETCH) {
115             base = pci_config_get_pref_base(
116                 bridge, PCI_PREF_MEMORY_BASE, PCI_PREF_BASE_UPPER32);
117         } else {
118             base = pci_config_get_memory_base(bridge, PCI_MEMORY_BASE);
119         }
120     }
121 
122     return base;
123 }
124 
125 /* accessor function to get bridge filtering limit */
126 pcibus_t pci_bridge_get_limit(const PCIDevice *bridge, uint8_t type)
127 {
128     pcibus_t limit;
129     if (type & PCI_BASE_ADDRESS_SPACE_IO) {
130         limit = pci_config_get_io_base(bridge,
131                                       PCI_IO_LIMIT, PCI_IO_LIMIT_UPPER16);
132         limit |= 0xfff;         /* PCI bridge spec 3.2.5.6. */
133     } else {
134         if (type & PCI_BASE_ADDRESS_MEM_PREFETCH) {
135             limit = pci_config_get_pref_base(
136                 bridge, PCI_PREF_MEMORY_LIMIT, PCI_PREF_LIMIT_UPPER32);
137         } else {
138             limit = pci_config_get_memory_base(bridge, PCI_MEMORY_LIMIT);
139         }
140         limit |= 0xfffff;       /* PCI bridge spec 3.2.5.{1, 8}. */
141     }
142     return limit;
143 }
144 
145 static void pci_bridge_init_alias(PCIBridge *bridge, MemoryRegion *alias,
146                                   uint8_t type, const char *name,
147                                   MemoryRegion *space,
148                                   MemoryRegion *parent_space,
149                                   bool enabled)
150 {
151     PCIDevice *bridge_dev = PCI_DEVICE(bridge);
152     pcibus_t base = pci_bridge_get_base(bridge_dev, type);
153     pcibus_t limit = pci_bridge_get_limit(bridge_dev, type);
154     /* TODO: this doesn't handle base = 0 limit = 2^64 - 1 correctly.
155      * Apparently no way to do this with existing memory APIs. */
156     pcibus_t size = enabled && limit >= base ? limit + 1 - base : 0;
157 
158     memory_region_init_alias(alias, OBJECT(bridge), name, space, base, size);
159     memory_region_add_subregion_overlap(parent_space, base, alias, 1);
160 }
161 
162 static void pci_bridge_init_vga_aliases(PCIBridge *br, PCIBus *parent,
163                                         MemoryRegion *alias_vga)
164 {
165     PCIDevice *pd = PCI_DEVICE(br);
166     uint16_t brctl = pci_get_word(pd->config + PCI_BRIDGE_CONTROL);
167 
168     memory_region_init_alias(&alias_vga[QEMU_PCI_VGA_IO_LO], OBJECT(br),
169                              "pci_bridge_vga_io_lo", &br->address_space_io,
170                              QEMU_PCI_VGA_IO_LO_BASE, QEMU_PCI_VGA_IO_LO_SIZE);
171     memory_region_init_alias(&alias_vga[QEMU_PCI_VGA_IO_HI], OBJECT(br),
172                              "pci_bridge_vga_io_hi", &br->address_space_io,
173                              QEMU_PCI_VGA_IO_HI_BASE, QEMU_PCI_VGA_IO_HI_SIZE);
174     memory_region_init_alias(&alias_vga[QEMU_PCI_VGA_MEM], OBJECT(br),
175                              "pci_bridge_vga_mem", &br->address_space_mem,
176                              QEMU_PCI_VGA_MEM_BASE, QEMU_PCI_VGA_MEM_SIZE);
177 
178     if (brctl & PCI_BRIDGE_CTL_VGA) {
179         pci_register_vga(pd, &alias_vga[QEMU_PCI_VGA_MEM],
180                          &alias_vga[QEMU_PCI_VGA_IO_LO],
181                          &alias_vga[QEMU_PCI_VGA_IO_HI]);
182     }
183 }
184 
185 static PCIBridgeWindows *pci_bridge_region_init(PCIBridge *br)
186 {
187     PCIDevice *pd = PCI_DEVICE(br);
188     PCIBus *parent = pci_get_bus(pd);
189     PCIBridgeWindows *w = g_new(PCIBridgeWindows, 1);
190     uint16_t cmd = pci_get_word(pd->config + PCI_COMMAND);
191 
192     pci_bridge_init_alias(br, &w->alias_pref_mem,
193                           PCI_BASE_ADDRESS_MEM_PREFETCH,
194                           "pci_bridge_pref_mem",
195                           &br->address_space_mem,
196                           parent->address_space_mem,
197                           cmd & PCI_COMMAND_MEMORY);
198     pci_bridge_init_alias(br, &w->alias_mem,
199                           PCI_BASE_ADDRESS_SPACE_MEMORY,
200                           "pci_bridge_mem",
201                           &br->address_space_mem,
202                           parent->address_space_mem,
203                           cmd & PCI_COMMAND_MEMORY);
204     pci_bridge_init_alias(br, &w->alias_io,
205                           PCI_BASE_ADDRESS_SPACE_IO,
206                           "pci_bridge_io",
207                           &br->address_space_io,
208                           parent->address_space_io,
209                           cmd & PCI_COMMAND_IO);
210 
211     pci_bridge_init_vga_aliases(br, parent, w->alias_vga);
212 
213     return w;
214 }
215 
216 static void pci_bridge_region_del(PCIBridge *br, PCIBridgeWindows *w)
217 {
218     PCIDevice *pd = PCI_DEVICE(br);
219     PCIBus *parent = pci_get_bus(pd);
220 
221     memory_region_del_subregion(parent->address_space_io, &w->alias_io);
222     memory_region_del_subregion(parent->address_space_mem, &w->alias_mem);
223     memory_region_del_subregion(parent->address_space_mem, &w->alias_pref_mem);
224     pci_unregister_vga(pd);
225 }
226 
227 static void pci_bridge_region_cleanup(PCIBridge *br, PCIBridgeWindows *w)
228 {
229     object_unparent(OBJECT(&w->alias_io));
230     object_unparent(OBJECT(&w->alias_mem));
231     object_unparent(OBJECT(&w->alias_pref_mem));
232     object_unparent(OBJECT(&w->alias_vga[QEMU_PCI_VGA_IO_LO]));
233     object_unparent(OBJECT(&w->alias_vga[QEMU_PCI_VGA_IO_HI]));
234     object_unparent(OBJECT(&w->alias_vga[QEMU_PCI_VGA_MEM]));
235     g_free(w);
236 }
237 
238 void pci_bridge_update_mappings(PCIBridge *br)
239 {
240     PCIBridgeWindows *w = br->windows;
241 
242     /* Make updates atomic to: handle the case of one VCPU updating the bridge
243      * while another accesses an unaffected region. */
244     memory_region_transaction_begin();
245     pci_bridge_region_del(br, br->windows);
246     pci_bridge_region_cleanup(br, w);
247     br->windows = pci_bridge_region_init(br);
248     memory_region_transaction_commit();
249 }
250 
251 /* default write_config function for PCI-to-PCI bridge */
252 void pci_bridge_write_config(PCIDevice *d,
253                              uint32_t address, uint32_t val, int len)
254 {
255     PCIBridge *s = PCI_BRIDGE(d);
256     uint16_t oldctl = pci_get_word(d->config + PCI_BRIDGE_CONTROL);
257     uint16_t newctl;
258 
259     pci_default_write_config(d, address, val, len);
260 
261     if (ranges_overlap(address, len, PCI_COMMAND, 2) ||
262 
263         /* io base/limit */
264         ranges_overlap(address, len, PCI_IO_BASE, 2) ||
265 
266         /* memory base/limit, prefetchable base/limit and
267            io base/limit upper 16 */
268         ranges_overlap(address, len, PCI_MEMORY_BASE, 20) ||
269 
270         /* vga enable */
271         ranges_overlap(address, len, PCI_BRIDGE_CONTROL, 2)) {
272         pci_bridge_update_mappings(s);
273     }
274 
275     newctl = pci_get_word(d->config + PCI_BRIDGE_CONTROL);
276     if (~oldctl & newctl & PCI_BRIDGE_CTL_BUS_RESET) {
277         /* Trigger hot reset on 0->1 transition. */
278         qbus_reset_all(BUS(&s->sec_bus));
279     }
280 }
281 
282 void pci_bridge_disable_base_limit(PCIDevice *dev)
283 {
284     uint8_t *conf = dev->config;
285 
286     pci_byte_test_and_set_mask(conf + PCI_IO_BASE,
287                                PCI_IO_RANGE_MASK & 0xff);
288     pci_byte_test_and_clear_mask(conf + PCI_IO_LIMIT,
289                                  PCI_IO_RANGE_MASK & 0xff);
290     pci_word_test_and_set_mask(conf + PCI_MEMORY_BASE,
291                                PCI_MEMORY_RANGE_MASK & 0xffff);
292     pci_word_test_and_clear_mask(conf + PCI_MEMORY_LIMIT,
293                                  PCI_MEMORY_RANGE_MASK & 0xffff);
294     pci_word_test_and_set_mask(conf + PCI_PREF_MEMORY_BASE,
295                                PCI_PREF_RANGE_MASK & 0xffff);
296     pci_word_test_and_clear_mask(conf + PCI_PREF_MEMORY_LIMIT,
297                                  PCI_PREF_RANGE_MASK & 0xffff);
298     pci_set_long(conf + PCI_PREF_BASE_UPPER32, 0);
299     pci_set_long(conf + PCI_PREF_LIMIT_UPPER32, 0);
300 }
301 
302 /* reset bridge specific configuration registers */
303 void pci_bridge_reset(DeviceState *qdev)
304 {
305     PCIDevice *dev = PCI_DEVICE(qdev);
306     uint8_t *conf = dev->config;
307 
308     conf[PCI_PRIMARY_BUS] = 0;
309     conf[PCI_SECONDARY_BUS] = 0;
310     conf[PCI_SUBORDINATE_BUS] = 0;
311     conf[PCI_SEC_LATENCY_TIMER] = 0;
312 
313     /*
314      * the default values for base/limit registers aren't specified
315      * in the PCI-to-PCI-bridge spec. So we don't touch them here.
316      * Each implementation can override it.
317      * typical implementation does
318      * zero base/limit registers or
319      * disable forwarding: pci_bridge_disable_base_limit()
320      * If disable forwarding is wanted, call pci_bridge_disable_base_limit()
321      * after this function.
322      */
323     pci_byte_test_and_clear_mask(conf + PCI_IO_BASE,
324                                  PCI_IO_RANGE_MASK & 0xff);
325     pci_byte_test_and_clear_mask(conf + PCI_IO_LIMIT,
326                                  PCI_IO_RANGE_MASK & 0xff);
327     pci_word_test_and_clear_mask(conf + PCI_MEMORY_BASE,
328                                  PCI_MEMORY_RANGE_MASK & 0xffff);
329     pci_word_test_and_clear_mask(conf + PCI_MEMORY_LIMIT,
330                                  PCI_MEMORY_RANGE_MASK & 0xffff);
331     pci_word_test_and_clear_mask(conf + PCI_PREF_MEMORY_BASE,
332                                  PCI_PREF_RANGE_MASK & 0xffff);
333     pci_word_test_and_clear_mask(conf + PCI_PREF_MEMORY_LIMIT,
334                                  PCI_PREF_RANGE_MASK & 0xffff);
335     pci_set_long(conf + PCI_PREF_BASE_UPPER32, 0);
336     pci_set_long(conf + PCI_PREF_LIMIT_UPPER32, 0);
337 
338     pci_set_word(conf + PCI_BRIDGE_CONTROL, 0);
339 }
340 
341 /* default qdev initialization function for PCI-to-PCI bridge */
342 void pci_bridge_initfn(PCIDevice *dev, const char *typename)
343 {
344     PCIBus *parent = pci_get_bus(dev);
345     PCIBridge *br = PCI_BRIDGE(dev);
346     PCIBus *sec_bus = &br->sec_bus;
347 
348     pci_word_test_and_set_mask(dev->config + PCI_STATUS,
349                                PCI_STATUS_66MHZ | PCI_STATUS_FAST_BACK);
350 
351     /*
352      * TODO: We implement VGA Enable in the Bridge Control Register
353      * therefore per the PCI to PCI bridge spec we must also implement
354      * VGA Palette Snooping.  When done, set this bit writable:
355      *
356      * pci_word_test_and_set_mask(dev->wmask + PCI_COMMAND,
357      *                            PCI_COMMAND_VGA_PALETTE);
358      */
359 
360     pci_config_set_class(dev->config, PCI_CLASS_BRIDGE_PCI);
361     dev->config[PCI_HEADER_TYPE] =
362         (dev->config[PCI_HEADER_TYPE] & PCI_HEADER_TYPE_MULTI_FUNCTION) |
363         PCI_HEADER_TYPE_BRIDGE;
364     pci_set_word(dev->config + PCI_SEC_STATUS,
365                  PCI_STATUS_66MHZ | PCI_STATUS_FAST_BACK);
366 
367     /*
368      * If we don't specify the name, the bus will be addressed as <id>.0, where
369      * id is the device id.
370      * Since PCI Bridge devices have a single bus each, we don't need the index:
371      * let users address the bus using the device name.
372      */
373     if (!br->bus_name && dev->qdev.id && *dev->qdev.id) {
374             br->bus_name = dev->qdev.id;
375     }
376 
377     qbus_create_inplace(sec_bus, sizeof(br->sec_bus), typename, DEVICE(dev),
378                         br->bus_name);
379     sec_bus->parent_dev = dev;
380     sec_bus->map_irq = br->map_irq ? br->map_irq : pci_swizzle_map_irq_fn;
381     sec_bus->address_space_mem = &br->address_space_mem;
382     memory_region_init(&br->address_space_mem, OBJECT(br), "pci_bridge_pci", UINT64_MAX);
383     sec_bus->address_space_io = &br->address_space_io;
384     memory_region_init(&br->address_space_io, OBJECT(br), "pci_bridge_io",
385                        4 * GiB);
386     br->windows = pci_bridge_region_init(br);
387     QLIST_INIT(&sec_bus->child);
388     QLIST_INSERT_HEAD(&parent->child, sec_bus, sibling);
389 }
390 
391 /* default qdev clean up function for PCI-to-PCI bridge */
392 void pci_bridge_exitfn(PCIDevice *pci_dev)
393 {
394     PCIBridge *s = PCI_BRIDGE(pci_dev);
395     assert(QLIST_EMPTY(&s->sec_bus.child));
396     QLIST_REMOVE(&s->sec_bus, sibling);
397     pci_bridge_region_del(s, s->windows);
398     pci_bridge_region_cleanup(s, s->windows);
399     /* object_unparent() is called automatically during device deletion */
400 }
401 
402 /*
403  * before qdev initialization(qdev_init()), this function sets bus_name and
404  * map_irq callback which are necessary for pci_bridge_initfn() to
405  * initialize bus.
406  */
407 void pci_bridge_map_irq(PCIBridge *br, const char* bus_name,
408                         pci_map_irq_fn map_irq)
409 {
410     br->map_irq = map_irq;
411     br->bus_name = bus_name;
412 }
413 
414 
415 int pci_bridge_qemu_reserve_cap_init(PCIDevice *dev, int cap_offset,
416                                      PCIResReserve res_reserve, Error **errp)
417 {
418     if (res_reserve.mem_pref_32 != (uint64_t)-1 &&
419         res_reserve.mem_pref_64 != (uint64_t)-1) {
420         error_setg(errp,
421                    "PCI resource reserve cap: PREF32 and PREF64 conflict");
422         return -EINVAL;
423     }
424 
425     if (res_reserve.mem_non_pref != (uint64_t)-1 &&
426         res_reserve.mem_non_pref >= 4 * GiB) {
427         error_setg(errp,
428                    "PCI resource reserve cap: mem-reserve must be less than 4G");
429         return -EINVAL;
430     }
431 
432     if (res_reserve.mem_pref_32 != (uint64_t)-1 &&
433         res_reserve.mem_pref_32 >= 4 * GiB) {
434         error_setg(errp,
435                    "PCI resource reserve cap: pref32-reserve  must be less than 4G");
436         return -EINVAL;
437     }
438 
439     if (res_reserve.bus == (uint32_t)-1 &&
440         res_reserve.io == (uint64_t)-1 &&
441         res_reserve.mem_non_pref == (uint64_t)-1 &&
442         res_reserve.mem_pref_32 == (uint64_t)-1 &&
443         res_reserve.mem_pref_64 == (uint64_t)-1) {
444         return 0;
445     }
446 
447     size_t cap_len = sizeof(PCIBridgeQemuCap);
448     PCIBridgeQemuCap cap = {
449             .len = cap_len,
450             .type = REDHAT_PCI_CAP_RESOURCE_RESERVE,
451             .bus_res = res_reserve.bus,
452             .io = res_reserve.io,
453             .mem = res_reserve.mem_non_pref,
454             .mem_pref_32 = res_reserve.mem_pref_32,
455             .mem_pref_64 = res_reserve.mem_pref_64
456     };
457 
458     int offset = pci_add_capability(dev, PCI_CAP_ID_VNDR,
459                                     cap_offset, cap_len, errp);
460     if (offset < 0) {
461         return offset;
462     }
463 
464     memcpy(dev->config + offset + PCI_CAP_FLAGS,
465            (char *)&cap + PCI_CAP_FLAGS,
466            cap_len - PCI_CAP_FLAGS);
467     return 0;
468 }
469 
470 static const TypeInfo pci_bridge_type_info = {
471     .name = TYPE_PCI_BRIDGE,
472     .parent = TYPE_PCI_DEVICE,
473     .instance_size = sizeof(PCIBridge),
474     .abstract = true,
475 };
476 
477 static void pci_bridge_register_types(void)
478 {
479     type_register_static(&pci_bridge_type_info);
480 }
481 
482 type_init(pci_bridge_register_types)
483