aboutsummaryrefslogtreecommitdiff
path: root/hw/pci.c
blob: a0f91a8c72bba42ae80da305234a4cda66c764e3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
/*
 * QEMU PCI bus manager
 *
 * Copyright (c) 2004 Fabrice Bellard
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#include "hw.h"
#include "pci.h"
#include "console.h"
#include "net.h"

//#define DEBUG_PCI

struct PCIBus {
    int bus_num;
    int devfn_min;
    pci_set_irq_fn set_irq;
    pci_map_irq_fn map_irq;
    uint32_t config_reg; /* XXX: suppress */
    /* low level pic */
    SetIRQFunc *low_set_irq;
    qemu_irq *irq_opaque;
    PCIDevice *devices[256];
    PCIDevice *parent_dev;
    PCIBus *next;
    /* The bus IRQ state is the logical OR of the connected devices.
       Keep a count of the number of devices with raised IRQs.  */
    int nirq;
    int irq_count[];
};

static void pci_update_mappings(PCIDevice *d);
static void pci_set_irq(void *opaque, int irq_num, int level);

target_phys_addr_t pci_mem_base;
static int pci_irq_index;
static PCIBus *first_bus;

static void pcibus_save(QEMUFile *f, void *opaque)
{
    PCIBus *bus = (PCIBus *)opaque;
    int i;

    qemu_put_be32(f, bus->nirq);
    for (i = 0; i < bus->nirq; i++)
        qemu_put_be32(f, bus->irq_count[i]);
}

static int  pcibus_load(QEMUFile *f, void *opaque, int version_id)
{
    PCIBus *bus = (PCIBus *)opaque;
    int i, nirq;

    if (version_id != 1)
        return -EINVAL;

    nirq = qemu_get_be32(f);
    if (bus->nirq != nirq) {
        fprintf(stderr, "pcibus_load: nirq mismatch: src=%d dst=%d\n",
                nirq, bus->nirq);
        return -EINVAL;
    }

    for (i = 0; i < nirq; i++)
        bus->irq_count[i] = qemu_get_be32(f);

    return 0;
}

PCIBus *pci_register_bus(pci_set_irq_fn set_irq, pci_map_irq_fn map_irq,
                         qemu_irq *pic, int devfn_min, int nirq)
{
    PCIBus *bus;
    static int nbus = 0;

    bus = qemu_mallocz(sizeof(PCIBus) + (nirq * sizeof(int)));
    bus->set_irq = set_irq;
    bus->map_irq = map_irq;
    bus->irq_opaque = pic;
    bus->devfn_min = devfn_min;
    bus->nirq = nirq;
    first_bus = bus;
    register_savevm("PCIBUS", nbus++, 1, pcibus_save, pcibus_load, bus);
    return bus;
}

static PCIBus *pci_register_secondary_bus(PCIDevice *dev, pci_map_irq_fn map_irq)
{
    PCIBus *bus;
    bus = qemu_mallocz(sizeof(PCIBus));
    bus->map_irq = map_irq;
    bus->parent_dev = dev;
    bus->next = dev->bus->next;
    dev->bus->next = bus;
    return bus;
}

int pci_bus_num(PCIBus *s)
{
    return s->bus_num;
}

void pci_device_save(PCIDevice *s, QEMUFile *f)
{
    int i;

    qemu_put_be32(f, 2); /* PCI device version */
    qemu_put_buffer(f, s->config, 256);
    for (i = 0; i < 4; i++)
        qemu_put_be32(f, s->irq_state[i]);
}

int pci_device_load(PCIDevice *s, QEMUFile *f)
{
    uint32_t version_id;
    int i;

    version_id = qemu_get_be32(f);
    if (version_id > 2)
        return -EINVAL;
    qemu_get_buffer(f, s->config, 256);
    pci_update_mappings(s);

    if (version_id >= 2)
        for (i = 0; i < 4; i ++)
            s->irq_state[i] = qemu_get_be32(f);

    return 0;
}

/* -1 for devfn means auto assign */
PCIDevice *pci_register_device(PCIBus *bus, const char *name,
                               int instance_size, int devfn,
                               PCIConfigReadFunc *config_read,
                               PCIConfigWriteFunc *config_write)
{
    PCIDevice *pci_dev;

    if (pci_irq_index >= PCI_DEVICES_MAX)
        return NULL;

    if (devfn < 0) {
        for(devfn = bus->devfn_min ; devfn < 256; devfn += 8) {
            if (!bus->devices[devfn])
                goto found;
        }
        return NULL;
    found: ;
    }
    pci_dev = qemu_mallocz(instance_size);
    if (!pci_dev)
        return NULL;
    pci_dev->bus = bus;
    pci_dev->devfn = devfn;
    pstrcpy(pci_dev->name, sizeof(pci_dev->name), name);
    memset(pci_dev->irq_state, 0, sizeof(pci_dev->irq_state));

    if (!config_read)
        config_read = pci_default_read_config;
    if (!config_write)
        config_write = pci_default_write_config;
    pci_dev->config_read = config_read;
    pci_dev->config_write = config_write;
    pci_dev->irq_index = pci_irq_index++;
    bus->devices[devfn] = pci_dev;
    pci_dev->irq = qemu_allocate_irqs(pci_set_irq, pci_dev, 4);
    return pci_dev;
}

void pci_register_io_region(PCIDevice *pci_dev, int region_num,
                            uint32_t size, int type,
                            PCIMapIORegionFunc *map_func)
{
    PCIIORegion *r;
    uint32_t addr;

    if ((unsigned int)region_num >= PCI_NUM_REGIONS)
        return;
    r = &pci_dev->io_regions[region_num];
    r->addr = -1;
    r->size = size;
    r->type = type;
    r->map_func = map_func;
    if (region_num == PCI_ROM_SLOT) {
        addr = 0x30;
    } else {
        addr = 0x10 + region_num * 4;
    }
    *(uint32_t *)(pci_dev->config + addr) = cpu_to_le32(type);
}

static target_phys_addr_t pci_to_cpu_addr(target_phys_addr_t addr)
{
    return addr + pci_mem_base;
}

static void pci_update_mappings(PCIDevice *d)
{
    PCIIORegion *r;
    int cmd, i;
    uint32_t last_addr, new_addr, config_ofs;

    cmd = le16_to_cpu(*(uint16_t *)(d->config + PCI_COMMAND));
    for(i = 0; i < PCI_NUM_REGIONS; i++) {
        r = &d->io_regions[i];
        if (i == PCI_ROM_SLOT) {
            config_ofs = 0x30;
        } else {
            config_ofs = 0x10 + i * 4;
        }
        if (r->size != 0) {
            if (r->type & PCI_ADDRESS_SPACE_IO) {
                if (cmd & PCI_COMMAND_IO) {
                    new_addr = le32_to_cpu(*(uint32_t *)(d->config +
                                                         config_ofs));
                    new_addr = new_addr & ~(r->size - 1);
                    last_addr = new_addr + r->size - 1;
                    /* NOTE: we have only 64K ioports on PC */
                    if (last_addr <= new_addr || new_addr == 0 ||
                        last_addr >= 0x10000) {
                        new_addr = -1;
                    }
                } else {
                    new_addr = -1;
                }
            } else {
                if (cmd & PCI_COMMAND_MEMORY) {
                    new_addr = le32_to_cpu(*(uint32_t *)(d->config +
                                                         config_ofs));
                    /* the ROM slot has a specific enable bit */
                    if (i == PCI_ROM_SLOT && !(new_addr & 1))
                        goto no_mem_map;
                    new_addr = new_addr & ~(r->size - 1);
                    last_addr = new_addr + r->size - 1;
                    /* NOTE: we do not support wrapping */
                    /* XXX: as we cannot support really dynamic
                       mappings, we handle specific values as invalid
                       mappings. */
                    if (last_addr <= new_addr || new_addr == 0 ||
                        last_addr == -1) {
                        new_addr = -1;
                    }
                } else {
                no_mem_map:
                    new_addr = -1;
                }
            }
            /* now do the real mapping */
            if (new_addr != r->addr) {
                if (r->addr != -1) {
                    if (r->type & PCI_ADDRESS_SPACE_IO) {
                        int class;
                        /* NOTE: specific hack for IDE in PC case:
                           only one byte must be mapped. */
                        class = d->config[0x0a] | (d->config[0x0b] << 8);
                        if (class == 0x0101 && r->size == 4) {
                            isa_unassign_ioport(r->addr + 2, 1);
                        } else {
                            isa_unassign_ioport(r->addr, r->size);
                        }
                    } else {
                        cpu_register_physical_memory(pci_to_cpu_addr(r->addr),
                                                     r->size,
                                                     IO_MEM_UNASSIGNED);
                    }
                }
                r->addr = new_addr;
                if (r->addr != -1) {
                    r->map_func(d, i, r->addr, r->size, r->type);
                }
            }
        }
    }
}

uint32_t pci_default_read_config(PCIDevice *d,
                                 uint32_t address, int len)
{
    uint32_t val;

    switch(len) {
    default:
    case 4:
	if (address <= 0xfc) {
	    val = le32_to_cpu(*(uint32_t *)(d->config + address));
	    break;
	}
	/* fall through */
    case 2:
        if (address <= 0xfe) {
	    val = le16_to_cpu(*(uint16_t *)(d->config + address));
	    break;
	}
	/* fall through */
    case 1:
        val = d->config[address];
        break;
    }
    return val;
}

void pci_default_write_config(PCIDevice *d,
                              uint32_t address, uint32_t val, int len)
{
    int can_write, i;
    uint32_t end, addr;

    if (len == 4 && ((address >= 0x10 && address < 0x10 + 4 * 6) ||
                     (address >= 0x30 && address < 0x34))) {
        PCIIORegion *r;
        int reg;

        if ( address >= 0x30 ) {
            reg = PCI_ROM_SLOT;
        }else{
            reg = (address - 0x10) >> 2;
        }
        r = &d->io_regions[reg];
        if (r->size == 0)
            goto default_config;
        /* compute the stored value */
        if (reg == PCI_ROM_SLOT) {
            /* keep ROM enable bit */
            val &= (~(r->size - 1)) | 1;
        } else {
            val &= ~(r->size - 1);
            val |= r->type;
        }
        *(uint32_t *)(d->config + address) = cpu_to_le32(val);
        pci_update_mappings(d);
        return;
    }
 default_config:
    /* not efficient, but simple */
    addr = address;
    for(i = 0; i < len; i++) {
        /* default read/write accesses */
        switch(d->config[0x0e]) {
        case 0x00:
        case 0x80:
            switch(addr) {
            case 0x00:
            case 0x01:
            case 0x02:
            case 0x03:
            case 0x08:
            case 0x09:
            case 0x0a:
            case 0x0b:
            case 0x0e:
            case 0x10 ... 0x27: /* base */
            case 0x30 ... 0x33: /* rom */
            case 0x3d:
                can_write = 0;
                break;
            default:
                can_write = 1;
                break;
            }
            break;
        default:
        case 0x01:
            switch(addr) {
            case 0x00:
            case 0x01:
            case 0x02:
            case 0x03:
            case 0x08:
            case 0x09:
            case 0x0a:
            case 0x0b:
            case 0x0e:
            case 0x38 ... 0x3b: /* rom */
            case 0x3d:
                can_write = 0;
                break;
            default:
                can_write = 1;
                break;
            }
            break;
        }
        if (can_write) {
            d->config[addr] = val;
        }
        if (++addr > 0xff)
        	break;
        val >>= 8;
    }

    end = address + len;
    if (end > PCI_COMMAND && address < (PCI_COMMAND + 2)) {
        /* if the command register is modified, we must modify the mappings */
        pci_update_mappings(d);
    }
}

void pci_data_write(void *opaque, uint32_t addr, uint32_t val, int len)
{
    PCIBus *s = opaque;
    PCIDevice *pci_dev;
    int config_addr, bus_num;

#if defined(DEBUG_PCI) && 0
    printf("pci_data_write: addr=%08x val=%08x len=%d\n",
           addr, val, len);
#endif
    bus_num = (addr >> 16) & 0xff;
    while (s && s->bus_num != bus_num)
        s = s->next;
    if (!s)
        return;
    pci_dev = s->devices[(addr >> 8) & 0xff];
    if (!pci_dev)
        return;
    config_addr = addr & 0xff;
#if defined(DEBUG_PCI)
    printf("pci_config_write: %s: addr=%02x val=%08x len=%d\n",
           pci_dev->name, config_addr, val, len);
#endif
    pci_dev->config_write(pci_dev, config_addr, val, len);
}

uint32_t pci_data_read(void *opaque, uint32_t addr, int len)
{
    PCIBus *s = opaque;
    PCIDevice *pci_dev;
    int config_addr, bus_num;
    uint32_t val;

    bus_num = (addr >> 16) & 0xff;
    while (s && s->bus_num != bus_num)
        s= s->next;
    if (!s)
        goto fail;
    pci_dev = s->devices[(addr >> 8) & 0xff];
    if (!pci_dev) {
    fail:
        switch(len) {
        case 1:
            val = 0xff;
            break;
        case 2:
            val = 0xffff;
            break;
        default:
        case 4:
            val = 0xffffffff;
            break;
        }
        goto the_end;
    }
    config_addr = addr & 0xff;
    val = pci_dev->config_read(pci_dev, config_addr, len);
#if defined(DEBUG_PCI)
    printf("pci_config_read: %s: addr=%02x val=%08x len=%d\n",
           pci_dev->name, config_addr, val, len);
#endif
 the_end:
#if defined(DEBUG_PCI) && 0
    printf("pci_data_read: addr=%08x val=%08x len=%d\n",
           addr, val, len);
#endif
    return val;
}

/***********************************************************/
/* generic PCI irq support */

/* 0 <= irq_num <= 3. level must be 0 or 1 */
static void pci_set_irq(void *opaque, int irq_num, int level)
{
    PCIDevice *pci_dev = (PCIDevice *)opaque;
    PCIBus *bus;
    int change;

    change = level - pci_dev->irq_state[irq_num];
    if (!change)
        return;

    pci_dev->irq_state[irq_num] = level;
    for (;;) {
        bus = pci_dev->bus;
        irq_num = bus->map_irq(pci_dev, irq_num);
        if (bus->set_irq)
            break;
        pci_dev = bus->parent_dev;
    }
    bus->irq_count[irq_num] += change;
    bus->set_irq(bus->irq_opaque, irq_num, bus->irq_count[irq_num] != 0);
}

/***********************************************************/
/* monitor info on PCI */

typedef struct {
    uint16_t class;
    const char *desc;
} pci_class_desc;

static const pci_class_desc pci_class_descriptions[] =
{
    { 0x0100, "SCSI controller"},
    { 0x0101, "IDE controller"},
    { 0x0102, "Floppy controller"},
    { 0x0103, "IPI controller"},
    { 0x0104, "RAID controller"},
    { 0x0106, "SATA controller"},
    { 0x0107, "SAS controller"},
    { 0x0180, "Storage controller"},
    { 0x0200, "Ethernet controller"},
    { 0x0201, "Token Ring controller"},
    { 0x0202, "FDDI controller"},
    { 0x0203, "ATM controller"},
    { 0x0280, "Network controller"},
    { 0x0300, "VGA controller"},
    { 0x0301, "XGA controller"},
    { 0x0302, "3D controller"},
    { 0x0380, "Display controller"},
    { 0x0400, "Video controller"},
    { 0x0401, "Audio controller"},
    { 0x0402, "Phone"},
    { 0x0480, "Multimedia controller"},
    { 0x0500, "RAM controller"},
    { 0x0501, "Flash controller"},
    { 0x0580, "Memory controller"},
    { 0x0600, "Host bridge"},
    { 0x0601, "ISA bridge"},
    { 0x0602, "EISA bridge"},
    { 0x0603, "MC bridge"},
    { 0x0604, "PCI bridge"},
    { 0x0605, "PCMCIA bridge"},
    { 0x0606, "NUBUS bridge"},
    { 0x0607, "CARDBUS bridge"},
    { 0x0608, "RACEWAY bridge"},
    { 0x0680, "Bridge"},
    { 0x0c03, "USB controller"},
    { 0, NULL}
};

static void pci_info_device(PCIDevice *d)
{
    int i, class;
    PCIIORegion *r;
    const pci_class_desc *desc;

    term_printf("  Bus %2d, device %3d, function %d:\n",
           d->bus->bus_num, d->devfn >> 3, d->devfn & 7);
    class = le16_to_cpu(*((uint16_t *)(d->config + PCI_CLASS_DEVICE)));
    term_printf("    ");
    desc = pci_class_descriptions;
    while (desc->desc && class != desc->class)
        desc++;
    if (desc->desc) {
        term_printf("%s", desc->desc);
    } else {
        term_printf("Class %04x", class);
    }
    term_printf(": PCI device %04x:%04x\n",
           le16_to_cpu(*((uint16_t *)(d->config + PCI_VENDOR_ID))),
           le16_to_cpu(*((uint16_t *)(d->config + PCI_DEVICE_ID))));

    if (d->config[PCI_INTERRUPT_PIN] != 0) {
        term_printf("      IRQ %d.\n", d->config[PCI_INTERRUPT_LINE]);
    }
    if (class == 0x0604) {
        term_printf("      BUS %d.\n", d->config[0x19]);
    }
    for(i = 0;i < PCI_NUM_REGIONS; i++) {
        r = &d->io_regions[i];
        if (r->size != 0) {
            term_printf("      BAR%d: ", i);
            if (r->type & PCI_ADDRESS_SPACE_IO) {
                term_printf("I/O at 0x%04x [0x%04x].\n",
                       r->addr, r->addr + r->size - 1);
            } else {
                term_printf("32 bit memory at 0x%08x [0x%08x].\n",
                       r->addr, r->addr + r->size - 1);
            }
        }
    }
    if (class == 0x0604 && d->config[0x19] != 0) {
        pci_for_each_device(d->config[0x19], pci_info_device);
    }
}

void pci_for_each_device(int bus_num, void (*fn)(PCIDevice *d))
{
    PCIBus *bus = first_bus;
    PCIDevice *d;
    int devfn;

    while (bus && bus->bus_num != bus_num)
        bus = bus->next;
    if (bus) {
        for(devfn = 0; devfn < 256; devfn++) {
            d = bus->devices[devfn];
            if (d)
                fn(d);
        }
    }
}

void pci_info(void)
{
    pci_for_each_device(0, pci_info_device);
}

/* Initialize a PCI NIC.  */
void pci_nic_init(PCIBus *bus, NICInfo *nd, int devfn)
{
    if (strcmp(nd->model, "ne2k_pci") == 0) {
        pci_ne2000_init(bus, nd, devfn);
    } else if (strcmp(nd->model, "i82551") == 0) {
        pci_i82551_init(bus, nd, devfn);
    } else if (strcmp(nd->model, "i82557b") == 0) {
        pci_i82557b_init(bus, nd, devfn);
    } else if (strcmp(nd->model, "i82559er") == 0) {
        pci_i82559er_init(bus, nd, devfn);
    } else if (strcmp(nd->model, "rtl8139") == 0) {
        pci_rtl8139_init(bus, nd, devfn);
    } else if (strcmp(nd->model, "e1000") == 0) {
        pci_e1000_init(bus, nd, devfn);
    } else if (strcmp(nd->model, "pcnet") == 0) {
        pci_pcnet_init(bus, nd, devfn);
    } else if (strcmp(nd->model, "?") == 0) {
        fprintf(stderr, "qemu: Supported PCI NICs: i82551 i82557b i82559er"
                        " ne2k_pci pcnet rtl8139 e1000\n");
        exit (1);
    } else {
        fprintf(stderr, "qemu: Unsupported NIC: %s\n", nd->model);
        exit (1);
    }
}

typedef struct {
    PCIDevice dev;
    PCIBus *bus;
} PCIBridge;

static void pci_bridge_write_config(PCIDevice *d,
                             uint32_t address, uint32_t val, int len)
{
    PCIBridge *s = (PCIBridge *)d;

    if (address == 0x19 || (address == 0x18 && len > 1)) {
        if (address == 0x19)
            s->bus->bus_num = val & 0xff;
        else
            s->bus->bus_num = (val >> 8) & 0xff;
#if defined(DEBUG_PCI)
        printf ("pci-bridge: %s: Assigned bus %d\n", d->name, s->bus->bus_num);
#endif
    }
    pci_default_write_config(d, address, val, len);
}

PCIBus *pci_bridge_init(PCIBus *bus, int devfn, uint32_t id,
                        pci_map_irq_fn map_irq, const char *name)
{
    PCIBridge *s;
    s = (PCIBridge *)pci_register_device(bus, name, sizeof(PCIBridge),
                                         devfn, NULL, pci_bridge_write_config);
    s->dev.config[0x00] = id >> 16;
    s->dev.config[0x01] = id >> 24;
    s->dev.config[0x02] = id; // device_id
    s->dev.config[0x03] = id >> 8;
    s->dev.config[0x04] = 0x06; // command = bus master, pci mem
    s->dev.config[0x05] = 0x00;
    s->dev.config[0x06] = 0xa0; // status = fast back-to-back, 66MHz, no error
    s->dev.config[0x07] = 0x00; // status = fast devsel
    s->dev.config[0x08] = 0x00; // revision
    s->dev.config[0x09] = 0x00; // programming i/f
    s->dev.config[0x0A] = 0x04; // class_sub = PCI to PCI bridge
    s->dev.config[0x0B] = 0x06; // class_base = PCI_bridge
    s->dev.config[0x0D] = 0x10; // latency_timer
    s->dev.config[0x0E] = 0x81; // header_type
    s->dev.config[0x1E] = 0xa0; // secondary status

    s->bus = pci_register_secondary_bus(&s->dev, map_irq);
    return s->bus;
}