xref: /openbmc/qemu/hw/pci/pci_bridge.c (revision f363d039)
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 "hw/pci/pci_bridge.h"
34 #include "hw/pci/pci_bus.h"
35 #include "qemu/module.h"
36 #include "qemu/range.h"
37 #include "qapi/error.h"
38 
39 /* PCI bridge subsystem vendor ID helper functions */
40 #define PCI_SSVID_SIZEOF        8
41 #define PCI_SSVID_SVID          4
42 #define PCI_SSVID_SSID          6
43 
44 int pci_bridge_ssvid_init(PCIDevice *dev, uint8_t offset,
45                           uint16_t svid, uint16_t ssid,
46                           Error **errp)
47 {
48     int pos;
49 
50     pos = pci_add_capability(dev, PCI_CAP_ID_SSVID, offset,
51                              PCI_SSVID_SIZEOF, errp);
52     if (pos < 0) {
53         return pos;
54     }
55 
56     pci_set_word(dev->config + pos + PCI_SSVID_SVID, svid);
57     pci_set_word(dev->config + pos + PCI_SSVID_SSID, ssid);
58     return pos;
59 }
60 
61 /* Accessor function to get parent bridge device from pci bus. */
62 PCIDevice *pci_bridge_get_device(PCIBus *bus)
63 {
64     return bus->parent_dev;
65 }
66 
67 /* Accessor function to get secondary bus from pci-to-pci bridge device */
68 PCIBus *pci_bridge_get_sec_bus(PCIBridge *br)
69 {
70     return &br->sec_bus;
71 }
72 
73 static uint32_t pci_config_get_io_base(const PCIDevice *d,
74                                        uint32_t base, uint32_t base_upper16)
75 {
76     uint32_t val;
77 
78     val = ((uint32_t)d->config[base] & PCI_IO_RANGE_MASK) << 8;
79     if (d->config[base] & PCI_IO_RANGE_TYPE_32) {
80         val |= (uint32_t)pci_get_word(d->config + base_upper16) << 16;
81     }
82     return val;
83 }
84 
85 static pcibus_t pci_config_get_memory_base(const PCIDevice *d, uint32_t base)
86 {
87     return ((pcibus_t)pci_get_word(d->config + base) & PCI_MEMORY_RANGE_MASK)
88         << 16;
89 }
90 
91 static pcibus_t pci_config_get_pref_base(const PCIDevice *d,
92                                          uint32_t base, uint32_t upper)
93 {
94     pcibus_t tmp;
95     pcibus_t val;
96 
97     tmp = (pcibus_t)pci_get_word(d->config + base);
98     val = (tmp & PCI_PREF_RANGE_MASK) << 16;
99     if (tmp & PCI_PREF_RANGE_TYPE_64) {
100         val |= (pcibus_t)pci_get_long(d->config + upper) << 32;
101     }
102     return val;
103 }
104 
105 /* accessor function to get bridge filtering base address */
106 pcibus_t pci_bridge_get_base(const PCIDevice *bridge, uint8_t type)
107 {
108     pcibus_t base;
109     if (type & PCI_BASE_ADDRESS_SPACE_IO) {
110         base = pci_config_get_io_base(bridge,
111                                       PCI_IO_BASE, PCI_IO_BASE_UPPER16);
112     } else {
113         if (type & PCI_BASE_ADDRESS_MEM_PREFETCH) {
114             base = pci_config_get_pref_base(
115                 bridge, PCI_PREF_MEMORY_BASE, PCI_PREF_BASE_UPPER32);
116         } else {
117             base = pci_config_get_memory_base(bridge, PCI_MEMORY_BASE);
118         }
119     }
120 
121     return base;
122 }
123 
124 /* accessor function to get bridge filtering limit */
125 pcibus_t pci_bridge_get_limit(const PCIDevice *bridge, uint8_t type)
126 {
127     pcibus_t limit;
128     if (type & PCI_BASE_ADDRESS_SPACE_IO) {
129         limit = pci_config_get_io_base(bridge,
130                                       PCI_IO_LIMIT, PCI_IO_LIMIT_UPPER16);
131         limit |= 0xfff;         /* PCI bridge spec 3.2.5.6. */
132     } else {
133         if (type & PCI_BASE_ADDRESS_MEM_PREFETCH) {
134             limit = pci_config_get_pref_base(
135                 bridge, PCI_PREF_MEMORY_LIMIT, PCI_PREF_LIMIT_UPPER32);
136         } else {
137             limit = pci_config_get_memory_base(bridge, PCI_MEMORY_LIMIT);
138         }
139         limit |= 0xfffff;       /* PCI bridge spec 3.2.5.{1, 8}. */
140     }
141     return limit;
142 }
143 
144 static void pci_bridge_init_alias(PCIBridge *bridge, MemoryRegion *alias,
145                                   uint8_t type, const char *name,
146                                   MemoryRegion *space,
147                                   MemoryRegion *parent_space,
148                                   bool enabled)
149 {
150     PCIDevice *bridge_dev = PCI_DEVICE(bridge);
151     pcibus_t base = pci_bridge_get_base(bridge_dev, type);
152     pcibus_t limit = pci_bridge_get_limit(bridge_dev, type);
153     /* TODO: this doesn't handle base = 0 limit = 2^64 - 1 correctly.
154      * Apparently no way to do this with existing memory APIs. */
155     pcibus_t size = enabled && limit >= base ? limit + 1 - base : 0;
156 
157     memory_region_init_alias(alias, OBJECT(bridge), name, space, base, size);
158     memory_region_add_subregion_overlap(parent_space, base, alias, 1);
159 }
160 
161 static void pci_bridge_init_vga_aliases(PCIBridge *br, PCIBus *parent,
162                                         MemoryRegion *alias_vga)
163 {
164     PCIDevice *pd = PCI_DEVICE(br);
165     uint16_t brctl = pci_get_word(pd->config + PCI_BRIDGE_CONTROL);
166 
167     memory_region_init_alias(&alias_vga[QEMU_PCI_VGA_IO_LO], OBJECT(br),
168                              "pci_bridge_vga_io_lo", &br->address_space_io,
169                              QEMU_PCI_VGA_IO_LO_BASE, QEMU_PCI_VGA_IO_LO_SIZE);
170     memory_region_init_alias(&alias_vga[QEMU_PCI_VGA_IO_HI], OBJECT(br),
171                              "pci_bridge_vga_io_hi", &br->address_space_io,
172                              QEMU_PCI_VGA_IO_HI_BASE, QEMU_PCI_VGA_IO_HI_SIZE);
173     memory_region_init_alias(&alias_vga[QEMU_PCI_VGA_MEM], OBJECT(br),
174                              "pci_bridge_vga_mem", &br->address_space_mem,
175                              QEMU_PCI_VGA_MEM_BASE, QEMU_PCI_VGA_MEM_SIZE);
176 
177     if (brctl & PCI_BRIDGE_CTL_VGA) {
178         pci_register_vga(pd, &alias_vga[QEMU_PCI_VGA_MEM],
179                          &alias_vga[QEMU_PCI_VGA_IO_LO],
180                          &alias_vga[QEMU_PCI_VGA_IO_HI]);
181     }
182 }
183 
184 static PCIBridgeWindows *pci_bridge_region_init(PCIBridge *br)
185 {
186     PCIDevice *pd = PCI_DEVICE(br);
187     PCIBus *parent = pci_get_bus(pd);
188     PCIBridgeWindows *w = g_new(PCIBridgeWindows, 1);
189     uint16_t cmd = pci_get_word(pd->config + PCI_COMMAND);
190 
191     pci_bridge_init_alias(br, &w->alias_pref_mem,
192                           PCI_BASE_ADDRESS_MEM_PREFETCH,
193                           "pci_bridge_pref_mem",
194                           &br->address_space_mem,
195                           parent->address_space_mem,
196                           cmd & PCI_COMMAND_MEMORY);
197     pci_bridge_init_alias(br, &w->alias_mem,
198                           PCI_BASE_ADDRESS_SPACE_MEMORY,
199                           "pci_bridge_mem",
200                           &br->address_space_mem,
201                           parent->address_space_mem,
202                           cmd & PCI_COMMAND_MEMORY);
203     pci_bridge_init_alias(br, &w->alias_io,
204                           PCI_BASE_ADDRESS_SPACE_IO,
205                           "pci_bridge_io",
206                           &br->address_space_io,
207                           parent->address_space_io,
208                           cmd & PCI_COMMAND_IO);
209 
210     pci_bridge_init_vga_aliases(br, parent, w->alias_vga);
211 
212     return w;
213 }
214 
215 static void pci_bridge_region_del(PCIBridge *br, PCIBridgeWindows *w)
216 {
217     PCIDevice *pd = PCI_DEVICE(br);
218     PCIBus *parent = pci_get_bus(pd);
219 
220     memory_region_del_subregion(parent->address_space_io, &w->alias_io);
221     memory_region_del_subregion(parent->address_space_mem, &w->alias_mem);
222     memory_region_del_subregion(parent->address_space_mem, &w->alias_pref_mem);
223     pci_unregister_vga(pd);
224 }
225 
226 static void pci_bridge_region_cleanup(PCIBridge *br, PCIBridgeWindows *w)
227 {
228     object_unparent(OBJECT(&w->alias_io));
229     object_unparent(OBJECT(&w->alias_mem));
230     object_unparent(OBJECT(&w->alias_pref_mem));
231     object_unparent(OBJECT(&w->alias_vga[QEMU_PCI_VGA_IO_LO]));
232     object_unparent(OBJECT(&w->alias_vga[QEMU_PCI_VGA_IO_HI]));
233     object_unparent(OBJECT(&w->alias_vga[QEMU_PCI_VGA_MEM]));
234     g_free(w);
235 }
236 
237 void pci_bridge_update_mappings(PCIBridge *br)
238 {
239     PCIBridgeWindows *w = br->windows;
240 
241     /* Make updates atomic to: handle the case of one VCPU updating the bridge
242      * while another accesses an unaffected region. */
243     memory_region_transaction_begin();
244     pci_bridge_region_del(br, br->windows);
245     pci_bridge_region_cleanup(br, w);
246     br->windows = pci_bridge_region_init(br);
247     memory_region_transaction_commit();
248 }
249 
250 /* default write_config function for PCI-to-PCI bridge */
251 void pci_bridge_write_config(PCIDevice *d,
252                              uint32_t address, uint32_t val, int len)
253 {
254     PCIBridge *s = PCI_BRIDGE(d);
255     uint16_t oldctl = pci_get_word(d->config + PCI_BRIDGE_CONTROL);
256     uint16_t newctl;
257 
258     pci_default_write_config(d, address, val, len);
259 
260     if (ranges_overlap(address, len, PCI_COMMAND, 2) ||
261 
262         /* io base/limit */
263         ranges_overlap(address, len, PCI_IO_BASE, 2) ||
264 
265         /* memory base/limit, prefetchable base/limit and
266            io base/limit upper 16 */
267         ranges_overlap(address, len, PCI_MEMORY_BASE, 20) ||
268 
269         /* vga enable */
270         ranges_overlap(address, len, PCI_BRIDGE_CONTROL, 2)) {
271         pci_bridge_update_mappings(s);
272     }
273 
274     newctl = pci_get_word(d->config + PCI_BRIDGE_CONTROL);
275     if (~oldctl & newctl & PCI_BRIDGE_CTL_BUS_RESET) {
276         /* Trigger hot reset on 0->1 transition. */
277         qbus_reset_all(BUS(&s->sec_bus));
278     }
279 }
280 
281 void pci_bridge_disable_base_limit(PCIDevice *dev)
282 {
283     uint8_t *conf = dev->config;
284 
285     pci_byte_test_and_set_mask(conf + PCI_IO_BASE,
286                                PCI_IO_RANGE_MASK & 0xff);
287     pci_byte_test_and_clear_mask(conf + PCI_IO_LIMIT,
288                                  PCI_IO_RANGE_MASK & 0xff);
289     pci_word_test_and_set_mask(conf + PCI_MEMORY_BASE,
290                                PCI_MEMORY_RANGE_MASK & 0xffff);
291     pci_word_test_and_clear_mask(conf + PCI_MEMORY_LIMIT,
292                                  PCI_MEMORY_RANGE_MASK & 0xffff);
293     pci_word_test_and_set_mask(conf + PCI_PREF_MEMORY_BASE,
294                                PCI_PREF_RANGE_MASK & 0xffff);
295     pci_word_test_and_clear_mask(conf + PCI_PREF_MEMORY_LIMIT,
296                                  PCI_PREF_RANGE_MASK & 0xffff);
297     pci_set_long(conf + PCI_PREF_BASE_UPPER32, 0);
298     pci_set_long(conf + PCI_PREF_LIMIT_UPPER32, 0);
299 }
300 
301 /* reset bridge specific configuration registers */
302 void pci_bridge_reset(DeviceState *qdev)
303 {
304     PCIDevice *dev = PCI_DEVICE(qdev);
305     uint8_t *conf = dev->config;
306 
307     conf[PCI_PRIMARY_BUS] = 0;
308     conf[PCI_SECONDARY_BUS] = 0;
309     conf[PCI_SUBORDINATE_BUS] = 0;
310     conf[PCI_SEC_LATENCY_TIMER] = 0;
311 
312     /*
313      * the default values for base/limit registers aren't specified
314      * in the PCI-to-PCI-bridge spec. So we don't thouch them here.
315      * Each implementation can override it.
316      * typical implementation does
317      * zero base/limit registers or
318      * disable forwarding: pci_bridge_disable_base_limit()
319      * If disable forwarding is wanted, call pci_bridge_disable_base_limit()
320      * after this function.
321      */
322     pci_byte_test_and_clear_mask(conf + PCI_IO_BASE,
323                                  PCI_IO_RANGE_MASK & 0xff);
324     pci_byte_test_and_clear_mask(conf + PCI_IO_LIMIT,
325                                  PCI_IO_RANGE_MASK & 0xff);
326     pci_word_test_and_clear_mask(conf + PCI_MEMORY_BASE,
327                                  PCI_MEMORY_RANGE_MASK & 0xffff);
328     pci_word_test_and_clear_mask(conf + PCI_MEMORY_LIMIT,
329                                  PCI_MEMORY_RANGE_MASK & 0xffff);
330     pci_word_test_and_clear_mask(conf + PCI_PREF_MEMORY_BASE,
331                                  PCI_PREF_RANGE_MASK & 0xffff);
332     pci_word_test_and_clear_mask(conf + PCI_PREF_MEMORY_LIMIT,
333                                  PCI_PREF_RANGE_MASK & 0xffff);
334     pci_set_long(conf + PCI_PREF_BASE_UPPER32, 0);
335     pci_set_long(conf + PCI_PREF_LIMIT_UPPER32, 0);
336 
337     pci_set_word(conf + PCI_BRIDGE_CONTROL, 0);
338 }
339 
340 /* default qdev initialization function for PCI-to-PCI bridge */
341 void pci_bridge_initfn(PCIDevice *dev, const char *typename)
342 {
343     PCIBus *parent = pci_get_bus(dev);
344     PCIBridge *br = PCI_BRIDGE(dev);
345     PCIBus *sec_bus = &br->sec_bus;
346 
347     pci_word_test_and_set_mask(dev->config + PCI_STATUS,
348                                PCI_STATUS_66MHZ | PCI_STATUS_FAST_BACK);
349 
350     /*
351      * TODO: We implement VGA Enable in the Bridge Control Register
352      * therefore per the PCI to PCI bridge spec we must also implement
353      * VGA Palette Snooping.  When done, set this bit writable:
354      *
355      * pci_word_test_and_set_mask(dev->wmask + PCI_COMMAND,
356      *                            PCI_COMMAND_VGA_PALETTE);
357      */
358 
359     pci_config_set_class(dev->config, PCI_CLASS_BRIDGE_PCI);
360     dev->config[PCI_HEADER_TYPE] =
361         (dev->config[PCI_HEADER_TYPE] & PCI_HEADER_TYPE_MULTI_FUNCTION) |
362         PCI_HEADER_TYPE_BRIDGE;
363     pci_set_word(dev->config + PCI_SEC_STATUS,
364                  PCI_STATUS_66MHZ | PCI_STATUS_FAST_BACK);
365 
366     /*
367      * If we don't specify the name, the bus will be addressed as <id>.0, where
368      * id is the device id.
369      * Since PCI Bridge devices have a single bus each, we don't need the index:
370      * let users address the bus using the device name.
371      */
372     if (!br->bus_name && dev->qdev.id && *dev->qdev.id) {
373             br->bus_name = dev->qdev.id;
374     }
375 
376     qbus_create_inplace(sec_bus, sizeof(br->sec_bus), typename, DEVICE(dev),
377                         br->bus_name);
378     sec_bus->parent_dev = dev;
379     sec_bus->map_irq = br->map_irq ? br->map_irq : pci_swizzle_map_irq_fn;
380     sec_bus->address_space_mem = &br->address_space_mem;
381     memory_region_init(&br->address_space_mem, OBJECT(br), "pci_bridge_pci", UINT64_MAX);
382     sec_bus->address_space_io = &br->address_space_io;
383     memory_region_init(&br->address_space_io, OBJECT(br), "pci_bridge_io",
384                        UINT32_MAX);
385     br->windows = pci_bridge_region_init(br);
386     QLIST_INIT(&sec_bus->child);
387     QLIST_INSERT_HEAD(&parent->child, sec_bus, sibling);
388 }
389 
390 /* default qdev clean up function for PCI-to-PCI bridge */
391 void pci_bridge_exitfn(PCIDevice *pci_dev)
392 {
393     PCIBridge *s = PCI_BRIDGE(pci_dev);
394     assert(QLIST_EMPTY(&s->sec_bus.child));
395     QLIST_REMOVE(&s->sec_bus, sibling);
396     pci_bridge_region_del(s, s->windows);
397     pci_bridge_region_cleanup(s, s->windows);
398     /* object_unparent() is called automatically during device deletion */
399 }
400 
401 /*
402  * before qdev initialization(qdev_init()), this function sets bus_name and
403  * map_irq callback which are necessary for pci_bridge_initfn() to
404  * initialize bus.
405  */
406 void pci_bridge_map_irq(PCIBridge *br, const char* bus_name,
407                         pci_map_irq_fn map_irq)
408 {
409     br->map_irq = map_irq;
410     br->bus_name = bus_name;
411 }
412 
413 
414 int pci_bridge_qemu_reserve_cap_init(PCIDevice *dev, int cap_offset,
415                                      PCIResReserve res_reserve, Error **errp)
416 {
417     if (res_reserve.mem_pref_32 != (uint64_t)-1 &&
418         res_reserve.mem_pref_64 != (uint64_t)-1) {
419         error_setg(errp,
420                    "PCI resource reserve cap: PREF32 and PREF64 conflict");
421         return -EINVAL;
422     }
423 
424     if (res_reserve.mem_non_pref != (uint64_t)-1 &&
425         res_reserve.mem_non_pref >= (1ULL << 32)) {
426         error_setg(errp,
427                    "PCI resource reserve cap: mem-reserve must be less than 4G");
428         return -EINVAL;
429     }
430 
431     if (res_reserve.mem_pref_32 != (uint64_t)-1 &&
432         res_reserve.mem_pref_32 >= (1ULL << 32)) {
433         error_setg(errp,
434                    "PCI resource reserve cap: pref32-reserve  must be less than 4G");
435         return -EINVAL;
436     }
437 
438     if (res_reserve.bus == (uint32_t)-1 &&
439         res_reserve.io == (uint64_t)-1 &&
440         res_reserve.mem_non_pref == (uint64_t)-1 &&
441         res_reserve.mem_pref_32 == (uint64_t)-1 &&
442         res_reserve.mem_pref_64 == (uint64_t)-1) {
443         return 0;
444     }
445 
446     size_t cap_len = sizeof(PCIBridgeQemuCap);
447     PCIBridgeQemuCap cap = {
448             .len = cap_len,
449             .type = REDHAT_PCI_CAP_RESOURCE_RESERVE,
450             .bus_res = res_reserve.bus,
451             .io = res_reserve.io,
452             .mem = res_reserve.mem_non_pref,
453             .mem_pref_32 = res_reserve.mem_pref_32,
454             .mem_pref_64 = res_reserve.mem_pref_64
455     };
456 
457     int offset = pci_add_capability(dev, PCI_CAP_ID_VNDR,
458                                     cap_offset, cap_len, errp);
459     if (offset < 0) {
460         return offset;
461     }
462 
463     memcpy(dev->config + offset + PCI_CAP_FLAGS,
464            (char *)&cap + PCI_CAP_FLAGS,
465            cap_len - PCI_CAP_FLAGS);
466     return 0;
467 }
468 
469 static const TypeInfo pci_bridge_type_info = {
470     .name = TYPE_PCI_BRIDGE,
471     .parent = TYPE_PCI_DEVICE,
472     .instance_size = sizeof(PCIBridge),
473     .abstract = true,
474 };
475 
476 static void pci_bridge_register_types(void)
477 {
478     type_register_static(&pci_bridge_type_info);
479 }
480 
481 type_init(pci_bridge_register_types)
482