xref: /freebsd/sys/dev/pci/pci_pci.c (revision 35a04710d7286aa9538917fd7f8e417dbee95b82)
1 /*-
2  * Copyright (c) 1994,1995 Stefan Esser, Wolfgang StanglMeier
3  * Copyright (c) 2000 Michael Smith <msmith@freebsd.org>
4  * Copyright (c) 2000 BSDi
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. The name of the author may not be used to endorse or promote products
16  *    derived from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 /*
35  * PCI:PCI bridge support.
36  */
37 
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/kernel.h>
41 #include <sys/module.h>
42 #include <sys/bus.h>
43 #include <machine/bus.h>
44 #include <sys/rman.h>
45 #include <sys/sysctl.h>
46 
47 #include <machine/resource.h>
48 
49 #include <dev/pci/pcivar.h>
50 #include <dev/pci/pcireg.h>
51 #include <dev/pci/pcib_private.h>
52 
53 #include "pcib_if.h"
54 
55 static int		pcib_probe(device_t dev);
56 
57 static device_method_t pcib_methods[] = {
58     /* Device interface */
59     DEVMETHOD(device_probe,		pcib_probe),
60     DEVMETHOD(device_attach,		pcib_attach),
61     DEVMETHOD(device_detach,		bus_generic_detach),
62     DEVMETHOD(device_shutdown,		bus_generic_shutdown),
63     DEVMETHOD(device_suspend,		bus_generic_suspend),
64     DEVMETHOD(device_resume,		bus_generic_resume),
65 
66     /* Bus interface */
67     DEVMETHOD(bus_print_child,		bus_generic_print_child),
68     DEVMETHOD(bus_read_ivar,		pcib_read_ivar),
69     DEVMETHOD(bus_write_ivar,		pcib_write_ivar),
70     DEVMETHOD(bus_alloc_resource,	pcib_alloc_resource),
71     DEVMETHOD(bus_release_resource,	bus_generic_release_resource),
72     DEVMETHOD(bus_activate_resource,	bus_generic_activate_resource),
73     DEVMETHOD(bus_deactivate_resource,	bus_generic_deactivate_resource),
74     DEVMETHOD(bus_setup_intr,		bus_generic_setup_intr),
75     DEVMETHOD(bus_teardown_intr,	bus_generic_teardown_intr),
76 
77     /* pcib interface */
78     DEVMETHOD(pcib_maxslots,		pcib_maxslots),
79     DEVMETHOD(pcib_read_config,		pcib_read_config),
80     DEVMETHOD(pcib_write_config,	pcib_write_config),
81     DEVMETHOD(pcib_route_interrupt,	pcib_route_interrupt),
82     DEVMETHOD(pcib_alloc_msi,		pcib_alloc_msi),
83     DEVMETHOD(pcib_release_msi,		pcib_release_msi),
84     DEVMETHOD(pcib_alloc_msix,		pcib_alloc_msix),
85     DEVMETHOD(pcib_release_msix,	pcib_release_msix),
86     DEVMETHOD(pcib_map_msi,		pcib_map_msi),
87 
88     { 0, 0 }
89 };
90 
91 static devclass_t pcib_devclass;
92 
93 DEFINE_CLASS_0(pcib, pcib_driver, pcib_methods, sizeof(struct pcib_softc));
94 DRIVER_MODULE(pcib, pci, pcib_driver, pcib_devclass, 0, 0);
95 
96 /*
97  * Is the prefetch window open (eg, can we allocate memory in it?)
98  */
99 static int
100 pcib_is_prefetch_open(struct pcib_softc *sc)
101 {
102 	return (sc->pmembase > 0 && sc->pmembase < sc->pmemlimit);
103 }
104 
105 /*
106  * Is the nonprefetch window open (eg, can we allocate memory in it?)
107  */
108 static int
109 pcib_is_nonprefetch_open(struct pcib_softc *sc)
110 {
111 	return (sc->membase > 0 && sc->membase < sc->memlimit);
112 }
113 
114 /*
115  * Is the io window open (eg, can we allocate ports in it?)
116  */
117 static int
118 pcib_is_io_open(struct pcib_softc *sc)
119 {
120 	return (sc->iobase > 0 && sc->iobase < sc->iolimit);
121 }
122 
123 /*
124  * Generic device interface
125  */
126 static int
127 pcib_probe(device_t dev)
128 {
129     if ((pci_get_class(dev) == PCIC_BRIDGE) &&
130 	(pci_get_subclass(dev) == PCIS_BRIDGE_PCI)) {
131 	device_set_desc(dev, "PCI-PCI bridge");
132 	return(-10000);
133     }
134     return(ENXIO);
135 }
136 
137 void
138 pcib_attach_common(device_t dev)
139 {
140     struct pcib_softc	*sc;
141     uint8_t		iolow;
142 
143     sc = device_get_softc(dev);
144     sc->dev = dev;
145 
146     /*
147      * Get current bridge configuration.
148      */
149     sc->command   = pci_read_config(dev, PCIR_COMMAND, 1);
150     sc->domain    = pci_get_domain(dev);
151     sc->secbus    = pci_read_config(dev, PCIR_SECBUS_1, 1);
152     sc->subbus    = pci_read_config(dev, PCIR_SUBBUS_1, 1);
153     sc->secstat   = pci_read_config(dev, PCIR_SECSTAT_1, 2);
154     sc->bridgectl = pci_read_config(dev, PCIR_BRIDGECTL_1, 2);
155     sc->seclat    = pci_read_config(dev, PCIR_SECLAT_1, 1);
156 
157     /*
158      * Determine current I/O decode.
159      */
160     if (sc->command & PCIM_CMD_PORTEN) {
161 	iolow = pci_read_config(dev, PCIR_IOBASEL_1, 1);
162 	if ((iolow & PCIM_BRIO_MASK) == PCIM_BRIO_32) {
163 	    sc->iobase = PCI_PPBIOBASE(pci_read_config(dev, PCIR_IOBASEH_1, 2),
164 				       pci_read_config(dev, PCIR_IOBASEL_1, 1));
165 	} else {
166 	    sc->iobase = PCI_PPBIOBASE(0, pci_read_config(dev, PCIR_IOBASEL_1, 1));
167 	}
168 
169 	iolow = pci_read_config(dev, PCIR_IOLIMITL_1, 1);
170 	if ((iolow & PCIM_BRIO_MASK) == PCIM_BRIO_32) {
171 	    sc->iolimit = PCI_PPBIOLIMIT(pci_read_config(dev, PCIR_IOLIMITH_1, 2),
172 					 pci_read_config(dev, PCIR_IOLIMITL_1, 1));
173 	} else {
174 	    sc->iolimit = PCI_PPBIOLIMIT(0, pci_read_config(dev, PCIR_IOLIMITL_1, 1));
175 	}
176     }
177 
178     /*
179      * Determine current memory decode.
180      */
181     if (sc->command & PCIM_CMD_MEMEN) {
182 	sc->membase   = PCI_PPBMEMBASE(0, pci_read_config(dev, PCIR_MEMBASE_1, 2));
183 	sc->memlimit  = PCI_PPBMEMLIMIT(0, pci_read_config(dev, PCIR_MEMLIMIT_1, 2));
184 	sc->pmembase  = PCI_PPBMEMBASE(pci_read_config(dev, PCIR_PMBASEH_1, 4),
185 	    pci_read_config(dev, PCIR_PMBASEL_1, 2));
186 	sc->pmemlimit = PCI_PPBMEMLIMIT(pci_read_config(dev, PCIR_PMLIMITH_1, 4),
187 	    pci_read_config(dev, PCIR_PMLIMITL_1, 2));
188     }
189 
190     /*
191      * Quirk handling.
192      */
193     switch (pci_get_devid(dev)) {
194     case 0x12258086:		/* Intel 82454KX/GX (Orion) */
195 	{
196 	    uint8_t	supbus;
197 
198 	    supbus = pci_read_config(dev, 0x41, 1);
199 	    if (supbus != 0xff) {
200 		sc->secbus = supbus + 1;
201 		sc->subbus = supbus + 1;
202 	    }
203 	    break;
204 	}
205 
206     /*
207      * The i82380FB mobile docking controller is a PCI-PCI bridge,
208      * and it is a subtractive bridge.  However, the ProgIf is wrong
209      * so the normal setting of PCIB_SUBTRACTIVE bit doesn't
210      * happen.  There's also a Toshiba bridge that behaves this
211      * way.
212      */
213     case 0x124b8086:		/* Intel 82380FB Mobile */
214     case 0x060513d7:		/* Toshiba ???? */
215 	sc->flags |= PCIB_SUBTRACTIVE;
216 	break;
217 
218     /* Compaq R3000 BIOS sets wrong subordinate bus number. */
219     case 0x00dd10de:
220 	{
221 	    char *cp;
222 
223 	    if ((cp = getenv("smbios.planar.maker")) == NULL)
224 		break;
225 	    if (strncmp(cp, "Compal", 6) != 0) {
226 		freeenv(cp);
227 		break;
228 	    }
229 	    freeenv(cp);
230 	    if ((cp = getenv("smbios.planar.product")) == NULL)
231 		break;
232 	    if (strncmp(cp, "08A0", 4) != 0) {
233 		freeenv(cp);
234 		break;
235 	    }
236 	    freeenv(cp);
237 	    if (sc->subbus < 0xa) {
238 		pci_write_config(dev, PCIR_SUBBUS_1, 0xa, 1);
239 		sc->subbus = pci_read_config(dev, PCIR_SUBBUS_1, 1);
240 	    }
241 	    break;
242 	}
243     }
244 
245     if (pci_msi_device_blacklisted(dev))
246 	sc->flags |= PCIB_DISABLE_MSI;
247 
248     /*
249      * Intel 815, 845 and other chipsets say they are PCI-PCI bridges,
250      * but have a ProgIF of 0x80.  The 82801 family (AA, AB, BAM/CAM,
251      * BA/CA/DB and E) PCI bridges are HUB-PCI bridges, in Intelese.
252      * This means they act as if they were subtractively decoding
253      * bridges and pass all transactions.  Mark them and real ProgIf 1
254      * parts as subtractive.
255      */
256     if ((pci_get_devid(dev) & 0xff00ffff) == 0x24008086 ||
257       pci_read_config(dev, PCIR_PROGIF, 1) == PCIP_BRIDGE_PCI_SUBTRACTIVE)
258 	sc->flags |= PCIB_SUBTRACTIVE;
259 
260     if (bootverbose) {
261 	device_printf(dev, "  domain            %d\n", sc->domain);
262 	device_printf(dev, "  secondary bus     %d\n", sc->secbus);
263 	device_printf(dev, "  subordinate bus   %d\n", sc->subbus);
264 	device_printf(dev, "  I/O decode        0x%x-0x%x\n", sc->iobase, sc->iolimit);
265 	if (pcib_is_nonprefetch_open(sc))
266 	    device_printf(dev, "  memory decode     0x%jx-0x%jx\n",
267 	      (uintmax_t)sc->membase, (uintmax_t)sc->memlimit);
268 	if (pcib_is_prefetch_open(sc))
269 	    device_printf(dev, "  prefetched decode 0x%jx-0x%jx\n",
270 	      (uintmax_t)sc->pmembase, (uintmax_t)sc->pmemlimit);
271 	else
272 	    device_printf(dev, "  no prefetched decode\n");
273 	if (sc->flags & PCIB_SUBTRACTIVE)
274 	    device_printf(dev, "  Subtractively decoded bridge.\n");
275     }
276 
277     /*
278      * XXX If the secondary bus number is zero, we should assign a bus number
279      *     since the BIOS hasn't, then initialise the bridge.
280      */
281 
282     /*
283      * XXX If the subordinate bus number is less than the secondary bus number,
284      *     we should pick a better value.  One sensible alternative would be to
285      *     pick 255; the only tradeoff here is that configuration transactions
286      *     would be more widely routed than absolutely necessary.
287      */
288 }
289 
290 int
291 pcib_attach(device_t dev)
292 {
293     struct pcib_softc	*sc;
294     device_t		child;
295 
296     pcib_attach_common(dev);
297     sc = device_get_softc(dev);
298     if (sc->secbus != 0) {
299 	child = device_add_child(dev, "pci", sc->secbus);
300 	if (child != NULL)
301 	    return(bus_generic_attach(dev));
302     }
303 
304     /* no secondary bus; we should have fixed this */
305     return(0);
306 }
307 
308 int
309 pcib_read_ivar(device_t dev, device_t child, int which, uintptr_t *result)
310 {
311     struct pcib_softc	*sc = device_get_softc(dev);
312 
313     switch (which) {
314     case PCIB_IVAR_DOMAIN:
315 	*result = sc->domain;
316 	return(0);
317     case PCIB_IVAR_BUS:
318 	*result = sc->secbus;
319 	return(0);
320     }
321     return(ENOENT);
322 }
323 
324 int
325 pcib_write_ivar(device_t dev, device_t child, int which, uintptr_t value)
326 {
327     struct pcib_softc	*sc = device_get_softc(dev);
328 
329     switch (which) {
330     case PCIB_IVAR_DOMAIN:
331 	return(EINVAL);
332     case PCIB_IVAR_BUS:
333 	sc->secbus = value;
334 	return(0);
335     }
336     return(ENOENT);
337 }
338 
339 /*
340  * We have to trap resource allocation requests and ensure that the bridge
341  * is set up to, or capable of handling them.
342  */
343 struct resource *
344 pcib_alloc_resource(device_t dev, device_t child, int type, int *rid,
345     u_long start, u_long end, u_long count, u_int flags)
346 {
347 	struct pcib_softc	*sc = device_get_softc(dev);
348 	const char *name, *suffix;
349 	int ok;
350 
351 	/*
352 	 * Fail the allocation for this range if it's not supported.
353 	 */
354 	name = device_get_nameunit(child);
355 	if (name == NULL) {
356 		name = "";
357 		suffix = "";
358 	} else
359 		suffix = " ";
360 	switch (type) {
361 	case SYS_RES_IOPORT:
362 		ok = 0;
363 		if (!pcib_is_io_open(sc))
364 			break;
365 		ok = (start >= sc->iobase && end <= sc->iolimit);
366 
367 		/*
368 		 * Make sure we allow access to VGA I/O addresses when the
369 		 * bridge has the "VGA Enable" bit set.
370 		 */
371 		if (!ok && pci_is_vga_ioport_range(start, end))
372 			ok = (sc->bridgectl & PCIB_BCR_VGA_ENABLE) ? 1 : 0;
373 
374 		if ((sc->flags & PCIB_SUBTRACTIVE) == 0) {
375 			if (!ok) {
376 				if (start < sc->iobase)
377 					start = sc->iobase;
378 				if (end > sc->iolimit)
379 					end = sc->iolimit;
380 				if (start < end)
381 					ok = 1;
382 			}
383 		} else {
384 			ok = 1;
385 #if 1
386 			if (start < sc->iobase && end > sc->iolimit) {
387 				start = sc->iobase;
388 				end = sc->iolimit;
389 			}
390 #endif
391 		}
392 		if (end < start) {
393 			device_printf(dev, "ioport: end (%lx) < start (%lx)\n",
394 			    end, start);
395 			start = 0;
396 			end = 0;
397 			ok = 0;
398 		}
399 		if (!ok) {
400 			device_printf(dev, "%s%srequested unsupported I/O "
401 			    "range 0x%lx-0x%lx (decoding 0x%x-0x%x)\n",
402 			    name, suffix, start, end, sc->iobase, sc->iolimit);
403 			return (NULL);
404 		}
405 		if (bootverbose)
406 			device_printf(dev,
407 			    "%s%srequested I/O range 0x%lx-0x%lx: in range\n",
408 			    name, suffix, start, end);
409 		break;
410 
411 	case SYS_RES_MEMORY:
412 		ok = 0;
413 		if (pcib_is_nonprefetch_open(sc))
414 			ok = ok || (start >= sc->membase && end <= sc->memlimit);
415 		if (pcib_is_prefetch_open(sc))
416 			ok = ok || (start >= sc->pmembase && end <= sc->pmemlimit);
417 
418 		/*
419 		 * Make sure we allow access to VGA memory addresses when the
420 		 * bridge has the "VGA Enable" bit set.
421 		 */
422 		if (!ok && pci_is_vga_memory_range(start, end))
423 			ok = (sc->bridgectl & PCIB_BCR_VGA_ENABLE) ? 1 : 0;
424 
425 		if ((sc->flags & PCIB_SUBTRACTIVE) == 0) {
426 			if (!ok) {
427 				ok = 1;
428 				if (flags & RF_PREFETCHABLE) {
429 					if (pcib_is_prefetch_open(sc)) {
430 						if (start < sc->pmembase)
431 							start = sc->pmembase;
432 						if (end > sc->pmemlimit)
433 							end = sc->pmemlimit;
434 					} else {
435 						ok = 0;
436 					}
437 				} else {	/* non-prefetchable */
438 					if (pcib_is_nonprefetch_open(sc)) {
439 						if (start < sc->membase)
440 							start = sc->membase;
441 						if (end > sc->memlimit)
442 							end = sc->memlimit;
443 					} else {
444 						ok = 0;
445 					}
446 				}
447 			}
448 		} else if (!ok) {
449 			ok = 1;	/* subtractive bridge: always ok */
450 #if 1
451 			if (pcib_is_nonprefetch_open(sc)) {
452 				if (start < sc->membase && end > sc->memlimit) {
453 					start = sc->membase;
454 					end = sc->memlimit;
455 				}
456 			}
457 			if (pcib_is_prefetch_open(sc)) {
458 				if (start < sc->pmembase && end > sc->pmemlimit) {
459 					start = sc->pmembase;
460 					end = sc->pmemlimit;
461 				}
462 			}
463 #endif
464 		}
465 		if (end < start) {
466 			device_printf(dev, "memory: end (%lx) < start (%lx)\n",
467 			    end, start);
468 			start = 0;
469 			end = 0;
470 			ok = 0;
471 		}
472 		if (!ok && bootverbose)
473 			device_printf(dev,
474 			    "%s%srequested unsupported memory range %#lx-%#lx "
475 			    "(decoding %#jx-%#jx, %#jx-%#jx)\n",
476 			    name, suffix, start, end,
477 			    (uintmax_t)sc->membase, (uintmax_t)sc->memlimit,
478 			    (uintmax_t)sc->pmembase, (uintmax_t)sc->pmemlimit);
479 		if (!ok)
480 			return (NULL);
481 		if (bootverbose)
482 			device_printf(dev,"%s%srequested memory range "
483 			    "0x%lx-0x%lx: good\n",
484 			    name, suffix, start, end);
485 		break;
486 
487 	default:
488 		break;
489 	}
490 	/*
491 	 * Bridge is OK decoding this resource, so pass it up.
492 	 */
493 	return (bus_generic_alloc_resource(dev, child, type, rid, start, end,
494 	    count, flags));
495 }
496 
497 /*
498  * PCIB interface.
499  */
500 int
501 pcib_maxslots(device_t dev)
502 {
503     return(PCI_SLOTMAX);
504 }
505 
506 /*
507  * Since we are a child of a PCI bus, its parent must support the pcib interface.
508  */
509 uint32_t
510 pcib_read_config(device_t dev, int b, int s, int f, int reg, int width)
511 {
512     return(PCIB_READ_CONFIG(device_get_parent(device_get_parent(dev)), b, s, f, reg, width));
513 }
514 
515 void
516 pcib_write_config(device_t dev, int b, int s, int f, int reg, uint32_t val, int width)
517 {
518     PCIB_WRITE_CONFIG(device_get_parent(device_get_parent(dev)), b, s, f, reg, val, width);
519 }
520 
521 /*
522  * Route an interrupt across a PCI bridge.
523  */
524 int
525 pcib_route_interrupt(device_t pcib, device_t dev, int pin)
526 {
527     device_t	bus;
528     int		parent_intpin;
529     int		intnum;
530 
531     /*
532      *
533      * The PCI standard defines a swizzle of the child-side device/intpin to
534      * the parent-side intpin as follows.
535      *
536      * device = device on child bus
537      * child_intpin = intpin on child bus slot (0-3)
538      * parent_intpin = intpin on parent bus slot (0-3)
539      *
540      * parent_intpin = (device + child_intpin) % 4
541      */
542     parent_intpin = (pci_get_slot(dev) + (pin - 1)) % 4;
543 
544     /*
545      * Our parent is a PCI bus.  Its parent must export the pcib interface
546      * which includes the ability to route interrupts.
547      */
548     bus = device_get_parent(pcib);
549     intnum = PCIB_ROUTE_INTERRUPT(device_get_parent(bus), pcib, parent_intpin + 1);
550     if (PCI_INTERRUPT_VALID(intnum) && bootverbose) {
551 	device_printf(pcib, "slot %d INT%c is routed to irq %d\n",
552 	    pci_get_slot(dev), 'A' + pin - 1, intnum);
553     }
554     return(intnum);
555 }
556 
557 /* Pass request to alloc MSI/MSI-X messages up to the parent bridge. */
558 int
559 pcib_alloc_msi(device_t pcib, device_t dev, int count, int maxcount, int *irqs)
560 {
561 	struct pcib_softc *sc = device_get_softc(pcib);
562 	device_t bus;
563 
564 	if (sc->flags & PCIB_DISABLE_MSI)
565 		return (ENXIO);
566 	bus = device_get_parent(pcib);
567 	return (PCIB_ALLOC_MSI(device_get_parent(bus), dev, count, maxcount,
568 	    irqs));
569 }
570 
571 /* Pass request to release MSI/MSI-X messages up to the parent bridge. */
572 int
573 pcib_release_msi(device_t pcib, device_t dev, int count, int *irqs)
574 {
575 	device_t bus;
576 
577 	bus = device_get_parent(pcib);
578 	return (PCIB_RELEASE_MSI(device_get_parent(bus), dev, count, irqs));
579 }
580 
581 /* Pass request to alloc an MSI-X message up to the parent bridge. */
582 int
583 pcib_alloc_msix(device_t pcib, device_t dev, int *irq)
584 {
585 	struct pcib_softc *sc = device_get_softc(pcib);
586 	device_t bus;
587 
588 	if (sc->flags & PCIB_DISABLE_MSI)
589 		return (ENXIO);
590 	bus = device_get_parent(pcib);
591 	return (PCIB_ALLOC_MSIX(device_get_parent(bus), dev, irq));
592 }
593 
594 /* Pass request to release an MSI-X message up to the parent bridge. */
595 int
596 pcib_release_msix(device_t pcib, device_t dev, int irq)
597 {
598 	device_t bus;
599 
600 	bus = device_get_parent(pcib);
601 	return (PCIB_RELEASE_MSIX(device_get_parent(bus), dev, irq));
602 }
603 
604 /* Pass request to map MSI/MSI-X message up to parent bridge. */
605 int
606 pcib_map_msi(device_t pcib, device_t dev, int irq, uint64_t *addr,
607     uint32_t *data)
608 {
609 	device_t bus;
610 
611 	bus = device_get_parent(pcib);
612 	return (PCIB_MAP_MSI(device_get_parent(bus), dev, irq, addr, data));
613 }
614 
615 /*
616  * Try to read the bus number of a host-PCI bridge using appropriate config
617  * registers.
618  */
619 int
620 host_pcib_get_busno(pci_read_config_fn read_config, int bus, int slot, int func,
621     uint8_t *busnum)
622 {
623 	uint32_t id;
624 
625 	id = read_config(bus, slot, func, PCIR_DEVVENDOR, 4);
626 	if (id == 0xffffffff)
627 		return (0);
628 
629 	switch (id) {
630 	case 0x12258086:
631 		/* Intel 824?? */
632 		/* XXX This is a guess */
633 		/* *busnum = read_config(bus, slot, func, 0x41, 1); */
634 		*busnum = bus;
635 		break;
636 	case 0x84c48086:
637 		/* Intel 82454KX/GX (Orion) */
638 		*busnum = read_config(bus, slot, func, 0x4a, 1);
639 		break;
640 	case 0x84ca8086:
641 		/*
642 		 * For the 450nx chipset, there is a whole bundle of
643 		 * things pretending to be host bridges. The MIOC will
644 		 * be seen first and isn't really a pci bridge (the
645 		 * actual busses are attached to the PXB's). We need to
646 		 * read the registers of the MIOC to figure out the
647 		 * bus numbers for the PXB channels.
648 		 *
649 		 * Since the MIOC doesn't have a pci bus attached, we
650 		 * pretend it wasn't there.
651 		 */
652 		return (0);
653 	case 0x84cb8086:
654 		switch (slot) {
655 		case 0x12:
656 			/* Intel 82454NX PXB#0, Bus#A */
657 			*busnum = read_config(bus, 0x10, func, 0xd0, 1);
658 			break;
659 		case 0x13:
660 			/* Intel 82454NX PXB#0, Bus#B */
661 			*busnum = read_config(bus, 0x10, func, 0xd1, 1) + 1;
662 			break;
663 		case 0x14:
664 			/* Intel 82454NX PXB#1, Bus#A */
665 			*busnum = read_config(bus, 0x10, func, 0xd3, 1);
666 			break;
667 		case 0x15:
668 			/* Intel 82454NX PXB#1, Bus#B */
669 			*busnum = read_config(bus, 0x10, func, 0xd4, 1) + 1;
670 			break;
671 		}
672 		break;
673 
674 		/* ServerWorks -- vendor 0x1166 */
675 	case 0x00051166:
676 	case 0x00061166:
677 	case 0x00081166:
678 	case 0x00091166:
679 	case 0x00101166:
680 	case 0x00111166:
681 	case 0x00171166:
682 	case 0x01011166:
683 	case 0x010f1014:
684 	case 0x02011166:
685 	case 0x03021014:
686 		*busnum = read_config(bus, slot, func, 0x44, 1);
687 		break;
688 
689 		/* Compaq/HP -- vendor 0x0e11 */
690 	case 0x60100e11:
691 		*busnum = read_config(bus, slot, func, 0xc8, 1);
692 		break;
693 	default:
694 		/* Don't know how to read bus number. */
695 		return 0;
696 	}
697 
698 	return 1;
699 }
700