hw/pci.c

   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 deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24 #include "hw.h"
  25 #include "pci.h"
  26 #include "console.h"
  27 #include "net.h"
  28
  29 //#define DEBUG_PCI
  30
  31 struct PCIBus {
  32     int bus_num;
  33     int devfn_min;
  34     pci_set_irq_fn set_irq;
  35     pci_map_irq_fn map_irq;
  36     uint32_t config_reg; /* XXX: suppress */
  37     /* low level pic */
  38     SetIRQFunc *low_set_irq;
  39     qemu_irq *irq_opaque;
  40     PCIDevice *devices[256];
  41     PCIDevice *parent_dev;
  42     PCIBus *next;
  43     /* The bus IRQ state is the logical OR of the connected devices.
  44        Keep a count of the number of devices with raised IRQs.  */
  45     int nirq;
  46     int irq_count[];
  47 };
  48
  49 static void pci_update_mappings(PCIDevice *d);
  50 static void pci_set_irq(void *opaque, int irq_num, int level);
  51
  52 target_phys_addr_t pci_mem_base;
  53 static int pci_irq_index;
  54 static PCIBus *first_bus;
  55
  56 static void pcibus_save(QEMUFile *f, void *opaque)
  57 {
  58     PCIBus *bus = (PCIBus *)opaque;
  59     int i;
  60
  61     qemu_put_be32(f, bus->nirq);
  62     for (i = 0; i < bus->nirq; i++)
  63         qemu_put_be32(f, bus->irq_count[i]);
  64 }
  65
  66 static int  pcibus_load(QEMUFile *f, void *opaque, int version_id)
  67 {
  68     PCIBus *bus = (PCIBus *)opaque;
  69     int i, nirq;
  70
  71     if (version_id != 1)
  72         return -EINVAL;
  73
  74     nirq = qemu_get_be32(f);
  75     if (bus->nirq != nirq) {
  76         fprintf(stderr, "pcibus_load: nirq mismatch: src=%d dst=%d\n",
  77                 nirq, bus->nirq);
  78         return -EINVAL;
  79     }
  80
  81     for (i = 0; i < nirq; i++)
  82         bus->irq_count[i] = qemu_get_be32(f);
  83
  84     return 0;
  85 }
  86
  87 PCIBus *pci_register_bus(pci_set_irq_fn set_irq, pci_map_irq_fn map_irq,
  88                          qemu_irq *pic, int devfn_min, int nirq)
  89 {
  90     PCIBus *bus;
  91     static int nbus = 0;
  92
  93     bus = qemu_mallocz(sizeof(PCIBus) + (nirq * sizeof(int)));
  94     bus->set_irq = set_irq;
  95     bus->map_irq = map_irq;
  96     bus->irq_opaque = pic;
  97     bus->devfn_min = devfn_min;
  98     bus->nirq = nirq;
  99     first_bus = bus;
 100     register_savevm("PCIBUS", nbus++, 1, pcibus_save, pcibus_load, bus);
 101     return bus;
 102 }
 103
 104 static PCIBus *pci_register_secondary_bus(PCIDevice *dev, pci_map_irq_fn map_irq)
 105 {
 106     PCIBus *bus;
 107     bus = qemu_mallocz(sizeof(PCIBus));
 108     bus->map_irq = map_irq;
 109     bus->parent_dev = dev;
 110     bus->next = dev->bus->next;
 111     dev->bus->next = bus;
 112     return bus;
 113 }
 114
 115 int pci_bus_num(PCIBus *s)
 116 {
 117     return s->bus_num;
 118 }
 119
 120 void pci_device_save(PCIDevice *s, QEMUFile *f)
 121 {
 122     int i;
 123
 124     qemu_put_be32(f, 2); /* PCI device version */
 125     qemu_put_buffer(f, s->config, 256);
 126     for (i = 0; i < 4; i++)
 127         qemu_put_be32(f, s->irq_state[i]);
 128 }
 129
 130 int pci_device_load(PCIDevice *s, QEMUFile *f)
 131 {
 132     uint32_t version_id;
 133     int i;
 134
 135     version_id = qemu_get_be32(f);
 136     if (version_id > 2)
 137         return -EINVAL;
 138     qemu_get_buffer(f, s->config, 256);
 139     pci_update_mappings(s);
 140
 141     if (version_id >= 2)
 142         for (i = 0; i < 4; i ++)
 143             s->irq_state[i] = qemu_get_be32(f);
 144
 145     return 0;
 146 }
 147
 148 /* -1 for devfn means auto assign */
 149 PCIDevice *pci_register_device(PCIBus *bus, const char *name,
 150                                int instance_size, int devfn,
 151                                PCIConfigReadFunc *config_read,
 152                                PCIConfigWriteFunc *config_write)
 153 {
 154     PCIDevice *pci_dev;
 155
 156     if (pci_irq_index >= PCI_DEVICES_MAX)
 157         return NULL;
 158
 159     if (devfn < 0) {
 160         for(devfn = bus->devfn_min ; devfn < 256; devfn += 8) {
 161             if (!bus->devices[devfn])
 162                 goto found;
 163         }
 164         return NULL;
 165     found: ;
 166     }
 167     pci_dev = qemu_mallocz(instance_size);
 168     if (!pci_dev)
 169         return NULL;
 170     pci_dev->bus = bus;
 171     pci_dev->devfn = devfn;
 172     pstrcpy(pci_dev->name, sizeof(pci_dev->name), name);
 173     memset(pci_dev->irq_state, 0, sizeof(pci_dev->irq_state));
 174
 175     if (!config_read)
 176         config_read = pci_default_read_config;
 177     if (!config_write)
 178         config_write = pci_default_write_config;
 179     pci_dev->config_read = config_read;
 180     pci_dev->config_write = config_write;
 181     pci_dev->irq_index = pci_irq_index++;
 182     bus->devices[devfn] = pci_dev;
 183     pci_dev->irq = qemu_allocate_irqs(pci_set_irq, pci_dev, 4);
 184     return pci_dev;
 185 }
 186
 187 void pci_register_io_region(PCIDevice *pci_dev, int region_num,
 188                             uint32_t size, int type,
 189                             PCIMapIORegionFunc *map_func)
 190 {
 191     PCIIORegion *r;
 192     uint32_t addr;
 193
 194     if ((unsigned int)region_num >= PCI_NUM_REGIONS)
 195         return;
 196     r = &pci_dev->io_regions[region_num];
 197     r->addr = -1;
 198     r->size = size;
 199     r->type = type;
 200     r->map_func = map_func;
 201     if (region_num == PCI_ROM_SLOT) {
 202         addr = 0x30;
 203     } else {
 204         addr = 0x10 + region_num * 4;
 205     }
 206     *(uint32_t *)(pci_dev->config + addr) = cpu_to_le32(type);
 207 }
 208
 209 static target_phys_addr_t pci_to_cpu_addr(target_phys_addr_t addr)
 210 {
 211     return addr + pci_mem_base;
 212 }
 213
 214 static void pci_update_mappings(PCIDevice *d)
 215 {
 216     PCIIORegion *r;
 217     int cmd, i;
 218     uint32_t last_addr, new_addr, config_ofs;
 219
 220     cmd = le16_to_cpu(*(uint16_t *)(d->config + PCI_COMMAND));
 221     for(i = 0; i < PCI_NUM_REGIONS; i++) {
 222         r = &d->io_regions[i];
 223         if (i == PCI_ROM_SLOT) {
 224             config_ofs = 0x30;
 225         } else {
 226             config_ofs = 0x10 + i * 4;
 227         }
 228         if (r->size != 0) {
 229             if (r->type & PCI_ADDRESS_SPACE_IO) {
 230                 if (cmd & PCI_COMMAND_IO) {
 231                     new_addr = le32_to_cpu(*(uint32_t *)(d->config +
 232                                                          config_ofs));
 233                     new_addr = new_addr & ~(r->size - 1);
 234                     last_addr = new_addr + r->size - 1;
 235                     /* NOTE: we have only 64K ioports on PC */
 236                     if (last_addr <= new_addr || new_addr == 0 ||
 237                         last_addr >= 0x10000) {
 238                         new_addr = -1;
 239                     }
 240                 } else {
 241                     new_addr = -1;
 242                 }
 243             } else {
 244                 if (cmd & PCI_COMMAND_MEMORY) {
 245                     new_addr = le32_to_cpu(*(uint32_t *)(d->config +
 246                                                          config_ofs));
 247                     /* the ROM slot has a specific enable bit */
 248                     if (i == PCI_ROM_SLOT && !(new_addr & 1))
 249                         goto no_mem_map;
 250                     new_addr = new_addr & ~(r->size - 1);
 251                     last_addr = new_addr + r->size - 1;
 252                     /* NOTE: we do not support wrapping */
 253                     /* XXX: as we cannot support really dynamic
 254                        mappings, we handle specific values as invalid
 255                        mappings. */
 256                     if (last_addr <= new_addr || new_addr == 0 ||
 257                         last_addr == -1) {
 258                         new_addr = -1;
 259                     }
 260                 } else {
 261                 no_mem_map:
 262                     new_addr = -1;
 263                 }
 264             }
 265             /* now do the real mapping */
 266             if (new_addr != r->addr) {
 267                 if (r->addr != -1) {
 268                     if (r->type & PCI_ADDRESS_SPACE_IO) {
 269                         int class;
 270                         /* NOTE: specific hack for IDE in PC case:
 271                            only one byte must be mapped. */
 272                         class = d->config[0x0a] | (d->config[0x0b] << 8);
 273                         if (class == 0x0101 && r->size == 4) {
 274                             isa_unassign_ioport(r->addr + 2, 1);
 275                         } else {
 276                             isa_unassign_ioport(r->addr, r->size);
 277                         }
 278                     } else {
 279                         cpu_register_physical_memory(pci_to_cpu_addr(r->addr),
 280                                                      r->size,
 281                                                      IO_MEM_UNASSIGNED);
 282                     }
 283                 }
 284                 r->addr = new_addr;
 285                 if (r->addr != -1) {
 286                     r->map_func(d, i, r->addr, r->size, r->type);
 287                 }
 288             }
 289         }
 290     }
 291 }
 292
 293 uint32_t pci_default_read_config(PCIDevice *d,
 294                                  uint32_t address, int len)
 295 {
 296     uint32_t val;
 297
 298     switch(len) {
 299     default:
 300     case 4:
 301         if (address <= 0xfc) {
 302             val = le32_to_cpu(*(uint32_t *)(d->config + address));
 303             break;
 304         }
 305         /* fall through */
 306     case 2:
 307         if (address <= 0xfe) {
 308             val = le16_to_cpu(*(uint16_t *)(d->config + address));
 309             break;
 310         }
 311         /* fall through */
 312     case 1:
 313         val = d->config[address];
 314         break;
 315     }
 316     return val;
 317 }
 318
 319 void pci_default_write_config(PCIDevice *d,
 320                               uint32_t address, uint32_t val, int len)
 321 {
 322     int can_write, i;
 323     uint32_t end, addr;
 324
 325     if (len == 4 && ((address >= 0x10 && address < 0x10 + 4 * 6) ||
 326                      (address >= 0x30 && address < 0x34))) {
 327         PCIIORegion *r;
 328         int reg;
 329
 330         if ( address >= 0x30 ) {
 331             reg = PCI_ROM_SLOT;
 332         }else{
 333             reg = (address - 0x10) >> 2;
 334         }
 335         r = &d->io_regions[reg];
 336         if (r->size == 0)
 337             goto default_config;
 338         /* compute the stored value */
 339         if (reg == PCI_ROM_SLOT) {
 340             /* keep ROM enable bit */
 341             val &= (~(r->size - 1)) | 1;
 342         } else {
 343             val &= ~(r->size - 1);
 344             val |= r->type;
 345         }
 346         *(uint32_t *)(d->config + address) = cpu_to_le32(val);
 347         pci_update_mappings(d);
 348         return;
 349     }
 350  default_config:
 351     /* not efficient, but simple */
 352     addr = address;
 353     for(i = 0; i < len; i++) {
 354         /* default read/write accesses */
 355         switch(d->config[0x0e]) {
 356         case 0x00:
 357         case 0x80:
 358             switch(addr) {
 359             case 0x00:
 360             case 0x01:
 361             case 0x02:
 362             case 0x03:
 363             case 0x08:
 364             case 0x09:
 365             case 0x0a:
 366             case 0x0b:
 367             case 0x0e:
 368             case 0x10 ... 0x27: /* base */
 369             case 0x30 ... 0x33: /* rom */
 370             case 0x3d:
 371                 can_write = 0;
 372                 break;
 373             default:
 374                 can_write = 1;
 375                 break;
 376             }
 377             break;
 378         default:
 379         case 0x01:
 380             switch(addr) {
 381             case 0x00:
 382             case 0x01:
 383             case 0x02:
 384             case 0x03:
 385             case 0x08:
 386             case 0x09:
 387             case 0x0a:
 388             case 0x0b:
 389             case 0x0e:
 390             case 0x38 ... 0x3b: /* rom */
 391             case 0x3d:
 392                 can_write = 0;
 393                 break;
 394             default:
 395                 can_write = 1;
 396                 break;
 397             }
 398             break;
 399         }
 400         if (can_write) {
 401             d->config[addr] = val;
 402         }
 403         if (++addr > 0xff)
 404                 break;
 405         val >>= 8;
 406     }
 407
 408     end = address + len;
 409     if (end > PCI_COMMAND && address < (PCI_COMMAND + 2)) {
 410         /* if the command register is modified, we must modify the mappings */
 411         pci_update_mappings(d);
 412     }
 413 }
 414
 415 void pci_data_write(void *opaque, uint32_t addr, uint32_t val, int len)
 416 {
 417     PCIBus *s = opaque;
 418     PCIDevice *pci_dev;
 419     int config_addr, bus_num;
 420
 421 #if defined(DEBUG_PCI) && 0
 422     printf("pci_data_write: addr=%08x val=%08x len=%d\n",
 423            addr, val, len);
 424 #endif
 425     bus_num = (addr >> 16) & 0xff;
 426     while (s && s->bus_num != bus_num)
 427         s = s->next;
 428     if (!s)
 429         return;
 430     pci_dev = s->devices[(addr >> 8) & 0xff];
 431     if (!pci_dev)
 432         return;
 433     config_addr = addr & 0xff;
 434 #if defined(DEBUG_PCI)
 435     printf("pci_config_write: %s: addr=%02x val=%08x len=%d\n",
 436            pci_dev->name, config_addr, val, len);
 437 #endif
 438     pci_dev->config_write(pci_dev, config_addr, val, len);
 439 }
 440
 441 uint32_t pci_data_read(void *opaque, uint32_t addr, int len)
 442 {
 443     PCIBus *s = opaque;
 444     PCIDevice *pci_dev;
 445     int config_addr, bus_num;
 446     uint32_t val;
 447
 448     bus_num = (addr >> 16) & 0xff;
 449     while (s && s->bus_num != bus_num)
 450         s= s->next;
 451     if (!s)
 452         goto fail;
 453     pci_dev = s->devices[(addr >> 8) & 0xff];
 454     if (!pci_dev) {
 455     fail:
 456         switch(len) {
 457         case 1:
 458             val = 0xff;
 459             break;
 460         case 2:
 461             val = 0xffff;
 462             break;
 463         default:
 464         case 4:
 465             val = 0xffffffff;
 466             break;
 467         }
 468         goto the_end;
 469     }
 470     config_addr = addr & 0xff;
 471     val = pci_dev->config_read(pci_dev, config_addr, len);
 472 #if defined(DEBUG_PCI)
 473     printf("pci_config_read: %s: addr=%02x val=%08x len=%d\n",
 474            pci_dev->name, config_addr, val, len);
 475 #endif
 476  the_end:
 477 #if defined(DEBUG_PCI) && 0
 478     printf("pci_data_read: addr=%08x val=%08x len=%d\n",
 479            addr, val, len);
 480 #endif
 481     return val;
 482 }
 483
 484 /***********************************************************/
 485 /* generic PCI irq support */
 486
 487 /* 0 <= irq_num <= 3. level must be 0 or 1 */
 488 static void pci_set_irq(void *opaque, int irq_num, int level)
 489 {
 490     PCIDevice *pci_dev = (PCIDevice *)opaque;
 491     PCIBus *bus;
 492     int change;
 493
 494     change = level - pci_dev->irq_state[irq_num];
 495     if (!change)
 496         return;
 497
 498     pci_dev->irq_state[irq_num] = level;
 499     for (;;) {
 500         bus = pci_dev->bus;
 501         irq_num = bus->map_irq(pci_dev, irq_num);
 502         if (bus->set_irq)
 503             break;
 504         pci_dev = bus->parent_dev;
 505     }
 506     bus->irq_count[irq_num] += change;
 507     bus->set_irq(bus->irq_opaque, irq_num, bus->irq_count[irq_num] != 0);
 508 }
 509
 510 /***********************************************************/
 511 /* monitor info on PCI */
 512
 513 typedef struct {
 514     uint16_t class;
 515     const char *desc;
 516 } pci_class_desc;
 517
 518 static pci_class_desc pci_class_descriptions[] =
 519 {
 520     { 0x0100, "SCSI controller"},
 521     { 0x0101, "IDE controller"},
 522     { 0x0102, "Floppy controller"},
 523     { 0x0103, "IPI controller"},
 524     { 0x0104, "RAID controller"},
 525     { 0x0106, "SATA controller"},
 526     { 0x0107, "SAS controller"},
 527     { 0x0180, "Storage controller"},
 528     { 0x0200, "Ethernet controller"},
 529     { 0x0201, "Token Ring controller"},
 530     { 0x0202, "FDDI controller"},
 531     { 0x0203, "ATM controller"},
 532     { 0x0280, "Network controller"},
 533     { 0x0300, "VGA controller"},
 534     { 0x0301, "XGA controller"},
 535     { 0x0302, "3D controller"},
 536     { 0x0380, "Display controller"},
 537     { 0x0400, "Video controller"},
 538     { 0x0401, "Audio controller"},
 539     { 0x0402, "Phone"},
 540     { 0x0480, "Multimedia controller"},
 541     { 0x0500, "RAM controller"},
 542     { 0x0501, "Flash controller"},
 543     { 0x0580, "Memory controller"},
 544     { 0x0600, "Host bridge"},
 545     { 0x0601, "ISA bridge"},
 546     { 0x0602, "EISA bridge"},
 547     { 0x0603, "MC bridge"},
 548     { 0x0604, "PCI bridge"},
 549     { 0x0605, "PCMCIA bridge"},
 550     { 0x0606, "NUBUS bridge"},
 551     { 0x0607, "CARDBUS bridge"},
 552     { 0x0608, "RACEWAY bridge"},
 553     { 0x0680, "Bridge"},
 554     { 0x0c03, "USB controller"},
 555     { 0, NULL}
 556 };
 557
 558 static void pci_info_device(PCIDevice *d)
 559 {
 560     int i, class;
 561     PCIIORegion *r;
 562     pci_class_desc *desc;
 563
 564     term_printf("  Bus %2d, device %3d, function %d:\n",
 565            d->bus->bus_num, d->devfn >> 3, d->devfn & 7);
 566     class = le16_to_cpu(*((uint16_t *)(d->config + PCI_CLASS_DEVICE)));
 567     term_printf("    ");
 568     desc = pci_class_descriptions;
 569     while (desc->desc && class != desc->class)
 570         desc++;
 571     if (desc->desc) {
 572         term_printf("%s", desc->desc);
 573     } else {
 574         term_printf("Class %04x", class);
 575     }
 576     term_printf(": PCI device %04x:%04x\n",
 577            le16_to_cpu(*((uint16_t *)(d->config + PCI_VENDOR_ID))),
 578            le16_to_cpu(*((uint16_t *)(d->config + PCI_DEVICE_ID))));
 579
 580     if (d->config[PCI_INTERRUPT_PIN] != 0) {
 581         term_printf("      IRQ %d.\n", d->config[PCI_INTERRUPT_LINE]);
 582     }
 583     if (class == 0x0604) {
 584         term_printf("      BUS %d.\n", d->config[0x19]);
 585     }
 586     for(i = 0;i < PCI_NUM_REGIONS; i++) {
 587         r = &d->io_regions[i];
 588         if (r->size != 0) {
 589             term_printf("      BAR%d: ", i);
 590             if (r->type & PCI_ADDRESS_SPACE_IO) {
 591                 term_printf("I/O at 0x%04x [0x%04x].\n",
 592                        r->addr, r->addr + r->size - 1);
 593             } else {
 594                 term_printf("32 bit memory at 0x%08x [0x%08x].\n",
 595                        r->addr, r->addr + r->size - 1);
 596             }
 597         }
 598     }
 599     if (class == 0x0604 && d->config[0x19] != 0) {
 600         pci_for_each_device(d->config[0x19], pci_info_device);
 601     }
 602 }
 603
 604 void pci_for_each_device(int bus_num, void (*fn)(PCIDevice *d))
 605 {
 606     PCIBus *bus = first_bus;
 607     PCIDevice *d;
 608     int devfn;
 609
 610     while (bus && bus->bus_num != bus_num)
 611         bus = bus->next;
 612     if (bus) {
 613         for(devfn = 0; devfn < 256; devfn++) {
 614             d = bus->devices[devfn];
 615             if (d)
 616                 fn(d);
 617         }
 618     }
 619 }
 620
 621 void pci_info(void)
 622 {
 623     pci_for_each_device(0, pci_info_device);
 624 }
 625
 626 /* Initialize a PCI NIC.  */
 627 void pci_nic_init(PCIBus *bus, NICInfo *nd, int devfn)
 628 {
 629     if (strcmp(nd->model, "ne2k_pci") == 0) {
 630         pci_ne2000_init(bus, nd, devfn);
 631     } else if (strcmp(nd->model, "i82551") == 0) {
 632         pci_i82551_init(bus, nd, devfn);
 633     } else if (strcmp(nd->model, "i82557b") == 0) {
 634         pci_i82557b_init(bus, nd, devfn);
 635     } else if (strcmp(nd->model, "i82559er") == 0) {
 636         pci_i82559er_init(bus, nd, devfn);
 637     } else if (strcmp(nd->model, "rtl8139") == 0) {
 638         pci_rtl8139_init(bus, nd, devfn);
 639     } else if (strcmp(nd->model, "pcnet") == 0) {
 640         pci_pcnet_init(bus, nd, devfn);
 641     } else if (strcmp(nd->model, "?") == 0) {
 642         fprintf(stderr, "qemu: Supported PCI NICs: i82551 i82557b i82559er"
 643                         " ne2k_pci pcnet rtl8139\n");
 644         exit (1);
 645     } else {
 646         fprintf(stderr, "qemu: Unsupported NIC: %s\n", nd->model);
 647         exit (1);
 648     }
 649 }
 650
 651 typedef struct {
 652     PCIDevice dev;
 653     PCIBus *bus;
 654 } PCIBridge;
 655
 656 static void pci_bridge_write_config(PCIDevice *d,
 657                              uint32_t address, uint32_t val, int len)
 658 {
 659     PCIBridge *s = (PCIBridge *)d;
 660
 661     if (address == 0x19 || (address == 0x18 && len > 1)) {
 662         if (address == 0x19)
 663             s->bus->bus_num = val & 0xff;
 664         else
 665             s->bus->bus_num = (val >> 8) & 0xff;
 666 #if defined(DEBUG_PCI)
 667         printf ("pci-bridge: %s: Assigned bus %d\n", d->name, s->bus->bus_num);
 668 #endif
 669     }
 670     pci_default_write_config(d, address, val, len);
 671 }
 672
 673 PCIBus *pci_bridge_init(PCIBus *bus, int devfn, uint32_t id,
 674                         pci_map_irq_fn map_irq, const char *name)
 675 {
 676     PCIBridge *s;
 677     s = (PCIBridge *)pci_register_device(bus, name, sizeof(PCIBridge),
 678                                          devfn, NULL, pci_bridge_write_config);
 679     s->dev.config[0x00] = id >> 16;
 680     s->dev.config[0x01] = id >> 24;
 681     s->dev.config[0x02] = id; // device_id
 682     s->dev.config[0x03] = id >> 8;
 683     s->dev.config[0x04] = 0x06; // command = bus master, pci mem
 684     s->dev.config[0x05] = 0x00;
 685     s->dev.config[0x06] = 0xa0; // status = fast back-to-back, 66MHz, no error
 686     s->dev.config[0x07] = 0x00; // status = fast devsel
 687     s->dev.config[0x08] = 0x00; // revision
 688     s->dev.config[0x09] = 0x00; // programming i/f
 689     s->dev.config[0x0A] = 0x04; // class_sub = PCI to PCI bridge
 690     s->dev.config[0x0B] = 0x06; // class_base = PCI_bridge
 691     s->dev.config[0x0D] = 0x10; // latency_timer
 692     s->dev.config[0x0E] = 0x81; // header_type
 693     s->dev.config[0x1E] = 0xa0; // secondary status
 694
 695     s->bus = pci_register_secondary_bus(&s->dev, map_irq);
 696     return s->bus;
 697 }