xref: /freebsd/sys/dev/pci/pci_pci.c (revision 1670a1c2a47d10ecccd001970b859caf93cd3b6e)
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 #ifdef __HAVE_ACPI
56 #include <contrib/dev/acpica/include/acpi.h>
57 #include "acpi_if.h"
58 #else
59 #define	ACPI_PWR_FOR_SLEEP(x, y, z)
60 #endif
61 
62 extern int		pci_do_power_resume;
63 
64 static int		pcib_probe(device_t dev);
65 static int		pcib_suspend(device_t dev);
66 static int		pcib_resume(device_t dev);
67 
68 static device_method_t pcib_methods[] = {
69     /* Device interface */
70     DEVMETHOD(device_probe,		pcib_probe),
71     DEVMETHOD(device_attach,		pcib_attach),
72     DEVMETHOD(device_detach,		bus_generic_detach),
73     DEVMETHOD(device_shutdown,		bus_generic_shutdown),
74     DEVMETHOD(device_suspend,		pcib_suspend),
75     DEVMETHOD(device_resume,		pcib_resume),
76 
77     /* Bus interface */
78     DEVMETHOD(bus_print_child,		bus_generic_print_child),
79     DEVMETHOD(bus_read_ivar,		pcib_read_ivar),
80     DEVMETHOD(bus_write_ivar,		pcib_write_ivar),
81     DEVMETHOD(bus_alloc_resource,	pcib_alloc_resource),
82     DEVMETHOD(bus_release_resource,	bus_generic_release_resource),
83     DEVMETHOD(bus_activate_resource,	bus_generic_activate_resource),
84     DEVMETHOD(bus_deactivate_resource,	bus_generic_deactivate_resource),
85     DEVMETHOD(bus_setup_intr,		bus_generic_setup_intr),
86     DEVMETHOD(bus_teardown_intr,	bus_generic_teardown_intr),
87 
88     /* pcib interface */
89     DEVMETHOD(pcib_maxslots,		pcib_maxslots),
90     DEVMETHOD(pcib_read_config,		pcib_read_config),
91     DEVMETHOD(pcib_write_config,	pcib_write_config),
92     DEVMETHOD(pcib_route_interrupt,	pcib_route_interrupt),
93     DEVMETHOD(pcib_alloc_msi,		pcib_alloc_msi),
94     DEVMETHOD(pcib_release_msi,		pcib_release_msi),
95     DEVMETHOD(pcib_alloc_msix,		pcib_alloc_msix),
96     DEVMETHOD(pcib_release_msix,	pcib_release_msix),
97     DEVMETHOD(pcib_map_msi,		pcib_map_msi),
98 
99     { 0, 0 }
100 };
101 
102 static devclass_t pcib_devclass;
103 
104 DEFINE_CLASS_0(pcib, pcib_driver, pcib_methods, sizeof(struct pcib_softc));
105 DRIVER_MODULE(pcib, pci, pcib_driver, pcib_devclass, 0, 0);
106 
107 /*
108  * Is the prefetch window open (eg, can we allocate memory in it?)
109  */
110 static int
111 pcib_is_prefetch_open(struct pcib_softc *sc)
112 {
113 	return (sc->pmembase > 0 && sc->pmembase < sc->pmemlimit);
114 }
115 
116 /*
117  * Is the nonprefetch window open (eg, can we allocate memory in it?)
118  */
119 static int
120 pcib_is_nonprefetch_open(struct pcib_softc *sc)
121 {
122 	return (sc->membase > 0 && sc->membase < sc->memlimit);
123 }
124 
125 /*
126  * Is the io window open (eg, can we allocate ports in it?)
127  */
128 static int
129 pcib_is_io_open(struct pcib_softc *sc)
130 {
131 	return (sc->iobase > 0 && sc->iobase < sc->iolimit);
132 }
133 
134 /*
135  * Get current I/O decode.
136  */
137 static void
138 pcib_get_io_decode(struct pcib_softc *sc)
139 {
140 	device_t	dev;
141 	uint32_t	iolow;
142 
143 	dev = sc->dev;
144 
145 	iolow = pci_read_config(dev, PCIR_IOBASEL_1, 1);
146 	if ((iolow & PCIM_BRIO_MASK) == PCIM_BRIO_32)
147 		sc->iobase = PCI_PPBIOBASE(
148 		    pci_read_config(dev, PCIR_IOBASEH_1, 2), iolow);
149 	else
150 		sc->iobase = PCI_PPBIOBASE(0, iolow);
151 
152 	iolow = pci_read_config(dev, PCIR_IOLIMITL_1, 1);
153 	if ((iolow & PCIM_BRIO_MASK) == PCIM_BRIO_32)
154 		sc->iolimit = PCI_PPBIOLIMIT(
155 		    pci_read_config(dev, PCIR_IOLIMITH_1, 2), iolow);
156 	else
157 		sc->iolimit = PCI_PPBIOLIMIT(0, iolow);
158 }
159 
160 /*
161  * Get current memory decode.
162  */
163 static void
164 pcib_get_mem_decode(struct pcib_softc *sc)
165 {
166 	device_t	dev;
167 	pci_addr_t	pmemlow;
168 
169 	dev = sc->dev;
170 
171 	sc->membase = PCI_PPBMEMBASE(0,
172 	    pci_read_config(dev, PCIR_MEMBASE_1, 2));
173 	sc->memlimit = PCI_PPBMEMLIMIT(0,
174 	    pci_read_config(dev, PCIR_MEMLIMIT_1, 2));
175 
176 	pmemlow = pci_read_config(dev, PCIR_PMBASEL_1, 2);
177 	if ((pmemlow & PCIM_BRPM_MASK) == PCIM_BRPM_64)
178 		sc->pmembase = PCI_PPBMEMBASE(
179 		    pci_read_config(dev, PCIR_PMBASEH_1, 4), pmemlow);
180 	else
181 		sc->pmembase = PCI_PPBMEMBASE(0, pmemlow);
182 
183 	pmemlow = pci_read_config(dev, PCIR_PMLIMITL_1, 2);
184 	if ((pmemlow & PCIM_BRPM_MASK) == PCIM_BRPM_64)
185 		sc->pmemlimit = PCI_PPBMEMLIMIT(
186 		    pci_read_config(dev, PCIR_PMLIMITH_1, 4), pmemlow);
187 	else
188 		sc->pmemlimit = PCI_PPBMEMLIMIT(0, pmemlow);
189 }
190 
191 /*
192  * Restore previous I/O decode.
193  */
194 static void
195 pcib_set_io_decode(struct pcib_softc *sc)
196 {
197 	device_t	dev;
198 	uint32_t	iohi;
199 
200 	dev = sc->dev;
201 
202 	iohi = sc->iobase >> 16;
203 	if (iohi > 0)
204 		pci_write_config(dev, PCIR_IOBASEH_1, iohi, 2);
205 	pci_write_config(dev, PCIR_IOBASEL_1, sc->iobase >> 8, 1);
206 
207 	iohi = sc->iolimit >> 16;
208 	if (iohi > 0)
209 		pci_write_config(dev, PCIR_IOLIMITH_1, iohi, 2);
210 	pci_write_config(dev, PCIR_IOLIMITL_1, sc->iolimit >> 8, 1);
211 }
212 
213 /*
214  * Restore previous memory decode.
215  */
216 static void
217 pcib_set_mem_decode(struct pcib_softc *sc)
218 {
219 	device_t	dev;
220 	pci_addr_t	pmemhi;
221 
222 	dev = sc->dev;
223 
224 	pci_write_config(dev, PCIR_MEMBASE_1, sc->membase >> 16, 2);
225 	pci_write_config(dev, PCIR_MEMLIMIT_1, sc->memlimit >> 16, 2);
226 
227 	pmemhi = sc->pmembase >> 32;
228 	if (pmemhi > 0)
229 		pci_write_config(dev, PCIR_PMBASEH_1, pmemhi, 4);
230 	pci_write_config(dev, PCIR_PMBASEL_1, sc->pmembase >> 16, 2);
231 
232 	pmemhi = sc->pmemlimit >> 32;
233 	if (pmemhi > 0)
234 		pci_write_config(dev, PCIR_PMLIMITH_1, pmemhi, 4);
235 	pci_write_config(dev, PCIR_PMLIMITL_1, sc->pmemlimit >> 16, 2);
236 }
237 
238 /*
239  * Get current bridge configuration.
240  */
241 static void
242 pcib_cfg_save(struct pcib_softc *sc)
243 {
244 	device_t	dev;
245 
246 	dev = sc->dev;
247 
248 	sc->command = pci_read_config(dev, PCIR_COMMAND, 2);
249 	sc->pribus = pci_read_config(dev, PCIR_PRIBUS_1, 1);
250 	sc->secbus = pci_read_config(dev, PCIR_SECBUS_1, 1);
251 	sc->subbus = pci_read_config(dev, PCIR_SUBBUS_1, 1);
252 	sc->bridgectl = pci_read_config(dev, PCIR_BRIDGECTL_1, 2);
253 	sc->seclat = pci_read_config(dev, PCIR_SECLAT_1, 1);
254 	if (sc->command & PCIM_CMD_PORTEN)
255 		pcib_get_io_decode(sc);
256 	if (sc->command & PCIM_CMD_MEMEN)
257 		pcib_get_mem_decode(sc);
258 }
259 
260 /*
261  * Restore previous bridge configuration.
262  */
263 static void
264 pcib_cfg_restore(struct pcib_softc *sc)
265 {
266 	device_t	dev;
267 
268 	dev = sc->dev;
269 
270 	pci_write_config(dev, PCIR_COMMAND, sc->command, 2);
271 	pci_write_config(dev, PCIR_PRIBUS_1, sc->pribus, 1);
272 	pci_write_config(dev, PCIR_SECBUS_1, sc->secbus, 1);
273 	pci_write_config(dev, PCIR_SUBBUS_1, sc->subbus, 1);
274 	pci_write_config(dev, PCIR_BRIDGECTL_1, sc->bridgectl, 2);
275 	pci_write_config(dev, PCIR_SECLAT_1, sc->seclat, 1);
276 	if (sc->command & PCIM_CMD_PORTEN)
277 		pcib_set_io_decode(sc);
278 	if (sc->command & PCIM_CMD_MEMEN)
279 		pcib_set_mem_decode(sc);
280 }
281 
282 /*
283  * Generic device interface
284  */
285 static int
286 pcib_probe(device_t dev)
287 {
288     if ((pci_get_class(dev) == PCIC_BRIDGE) &&
289 	(pci_get_subclass(dev) == PCIS_BRIDGE_PCI)) {
290 	device_set_desc(dev, "PCI-PCI bridge");
291 	return(-10000);
292     }
293     return(ENXIO);
294 }
295 
296 void
297 pcib_attach_common(device_t dev)
298 {
299     struct pcib_softc	*sc;
300     struct sysctl_ctx_list *sctx;
301     struct sysctl_oid	*soid;
302 
303     sc = device_get_softc(dev);
304     sc->dev = dev;
305 
306     /*
307      * Get current bridge configuration.
308      */
309     sc->domain = pci_get_domain(dev);
310     sc->secstat = pci_read_config(dev, PCIR_SECSTAT_1, 2);
311     pcib_cfg_save(sc);
312 
313     /*
314      * Setup sysctl reporting nodes
315      */
316     sctx = device_get_sysctl_ctx(dev);
317     soid = device_get_sysctl_tree(dev);
318     SYSCTL_ADD_UINT(sctx, SYSCTL_CHILDREN(soid), OID_AUTO, "domain",
319       CTLFLAG_RD, &sc->domain, 0, "Domain number");
320     SYSCTL_ADD_UINT(sctx, SYSCTL_CHILDREN(soid), OID_AUTO, "pribus",
321       CTLFLAG_RD, &sc->pribus, 0, "Primary bus number");
322     SYSCTL_ADD_UINT(sctx, SYSCTL_CHILDREN(soid), OID_AUTO, "secbus",
323       CTLFLAG_RD, &sc->secbus, 0, "Secondary bus number");
324     SYSCTL_ADD_UINT(sctx, SYSCTL_CHILDREN(soid), OID_AUTO, "subbus",
325       CTLFLAG_RD, &sc->subbus, 0, "Subordinate bus number");
326 
327     /*
328      * Quirk handling.
329      */
330     switch (pci_get_devid(dev)) {
331     case 0x12258086:		/* Intel 82454KX/GX (Orion) */
332 	{
333 	    uint8_t	supbus;
334 
335 	    supbus = pci_read_config(dev, 0x41, 1);
336 	    if (supbus != 0xff) {
337 		sc->secbus = supbus + 1;
338 		sc->subbus = supbus + 1;
339 	    }
340 	    break;
341 	}
342 
343     /*
344      * The i82380FB mobile docking controller is a PCI-PCI bridge,
345      * and it is a subtractive bridge.  However, the ProgIf is wrong
346      * so the normal setting of PCIB_SUBTRACTIVE bit doesn't
347      * happen.  There's also a Toshiba bridge that behaves this
348      * way.
349      */
350     case 0x124b8086:		/* Intel 82380FB Mobile */
351     case 0x060513d7:		/* Toshiba ???? */
352 	sc->flags |= PCIB_SUBTRACTIVE;
353 	break;
354 
355     /* Compaq R3000 BIOS sets wrong subordinate bus number. */
356     case 0x00dd10de:
357 	{
358 	    char *cp;
359 
360 	    if ((cp = getenv("smbios.planar.maker")) == NULL)
361 		break;
362 	    if (strncmp(cp, "Compal", 6) != 0) {
363 		freeenv(cp);
364 		break;
365 	    }
366 	    freeenv(cp);
367 	    if ((cp = getenv("smbios.planar.product")) == NULL)
368 		break;
369 	    if (strncmp(cp, "08A0", 4) != 0) {
370 		freeenv(cp);
371 		break;
372 	    }
373 	    freeenv(cp);
374 	    if (sc->subbus < 0xa) {
375 		pci_write_config(dev, PCIR_SUBBUS_1, 0xa, 1);
376 		sc->subbus = pci_read_config(dev, PCIR_SUBBUS_1, 1);
377 	    }
378 	    break;
379 	}
380     }
381 
382     if (pci_msi_device_blacklisted(dev))
383 	sc->flags |= PCIB_DISABLE_MSI;
384 
385     /*
386      * Intel 815, 845 and other chipsets say they are PCI-PCI bridges,
387      * but have a ProgIF of 0x80.  The 82801 family (AA, AB, BAM/CAM,
388      * BA/CA/DB and E) PCI bridges are HUB-PCI bridges, in Intelese.
389      * This means they act as if they were subtractively decoding
390      * bridges and pass all transactions.  Mark them and real ProgIf 1
391      * parts as subtractive.
392      */
393     if ((pci_get_devid(dev) & 0xff00ffff) == 0x24008086 ||
394       pci_read_config(dev, PCIR_PROGIF, 1) == PCIP_BRIDGE_PCI_SUBTRACTIVE)
395 	sc->flags |= PCIB_SUBTRACTIVE;
396 
397     if (bootverbose) {
398 	device_printf(dev, "  domain            %d\n", sc->domain);
399 	device_printf(dev, "  secondary bus     %d\n", sc->secbus);
400 	device_printf(dev, "  subordinate bus   %d\n", sc->subbus);
401 	device_printf(dev, "  I/O decode        0x%x-0x%x\n", sc->iobase, sc->iolimit);
402 	if (pcib_is_nonprefetch_open(sc))
403 	    device_printf(dev, "  memory decode     0x%jx-0x%jx\n",
404 	      (uintmax_t)sc->membase, (uintmax_t)sc->memlimit);
405 	if (pcib_is_prefetch_open(sc))
406 	    device_printf(dev, "  prefetched decode 0x%jx-0x%jx\n",
407 	      (uintmax_t)sc->pmembase, (uintmax_t)sc->pmemlimit);
408 	else
409 	    device_printf(dev, "  no prefetched decode\n");
410 	if (sc->flags & PCIB_SUBTRACTIVE)
411 	    device_printf(dev, "  Subtractively decoded bridge.\n");
412     }
413 
414     /*
415      * XXX If the secondary bus number is zero, we should assign a bus number
416      *     since the BIOS hasn't, then initialise the bridge.  A simple
417      *     bus_alloc_resource with the a couple of busses seems like the right
418      *     approach, but we don't know what busses the BIOS might have already
419      *     assigned to other bridges on this bus that probe later than we do.
420      *
421      *     If the subordinate bus number is less than the secondary bus number,
422      *     we should pick a better value.  One sensible alternative would be to
423      *     pick 255; the only tradeoff here is that configuration transactions
424      *     would be more widely routed than absolutely necessary.  We could
425      *     then do a walk of the tree later and fix it.
426      */
427 }
428 
429 int
430 pcib_attach(device_t dev)
431 {
432     struct pcib_softc	*sc;
433     device_t		child;
434 
435     pcib_attach_common(dev);
436     sc = device_get_softc(dev);
437     if (sc->secbus != 0) {
438 	child = device_add_child(dev, "pci", sc->secbus);
439 	if (child != NULL)
440 	    return(bus_generic_attach(dev));
441     }
442 
443     /* no secondary bus; we should have fixed this */
444     return(0);
445 }
446 
447 int
448 pcib_suspend(device_t dev)
449 {
450 	device_t	acpi_dev;
451 	int		dstate, error;
452 
453 	pcib_cfg_save(device_get_softc(dev));
454 	error = bus_generic_suspend(dev);
455 	if (error == 0 && pci_do_power_resume) {
456 		acpi_dev = devclass_get_device(devclass_find("acpi"), 0);
457 		if (acpi_dev != NULL) {
458 			dstate = PCI_POWERSTATE_D3;
459 			ACPI_PWR_FOR_SLEEP(acpi_dev, dev, &dstate);
460 			pci_set_powerstate(dev, dstate);
461 		}
462 	}
463 	return (error);
464 }
465 
466 int
467 pcib_resume(device_t dev)
468 {
469 	device_t	acpi_dev;
470 
471 	if (pci_do_power_resume) {
472 		acpi_dev = devclass_get_device(devclass_find("acpi"), 0);
473 		if (acpi_dev != NULL) {
474 			ACPI_PWR_FOR_SLEEP(acpi_dev, dev, NULL);
475 			pci_set_powerstate(dev, PCI_POWERSTATE_D0);
476 		}
477 	}
478 	pcib_cfg_restore(device_get_softc(dev));
479 	return (bus_generic_resume(dev));
480 }
481 
482 int
483 pcib_read_ivar(device_t dev, device_t child, int which, uintptr_t *result)
484 {
485     struct pcib_softc	*sc = device_get_softc(dev);
486 
487     switch (which) {
488     case PCIB_IVAR_DOMAIN:
489 	*result = sc->domain;
490 	return(0);
491     case PCIB_IVAR_BUS:
492 	*result = sc->secbus;
493 	return(0);
494     }
495     return(ENOENT);
496 }
497 
498 int
499 pcib_write_ivar(device_t dev, device_t child, int which, uintptr_t value)
500 {
501     struct pcib_softc	*sc = device_get_softc(dev);
502 
503     switch (which) {
504     case PCIB_IVAR_DOMAIN:
505 	return(EINVAL);
506     case PCIB_IVAR_BUS:
507 	sc->secbus = value;
508 	return(0);
509     }
510     return(ENOENT);
511 }
512 
513 /*
514  * We have to trap resource allocation requests and ensure that the bridge
515  * is set up to, or capable of handling them.
516  */
517 struct resource *
518 pcib_alloc_resource(device_t dev, device_t child, int type, int *rid,
519     u_long start, u_long end, u_long count, u_int flags)
520 {
521 	struct pcib_softc	*sc = device_get_softc(dev);
522 	const char *name, *suffix;
523 	int ok;
524 
525 	/*
526 	 * Fail the allocation for this range if it's not supported.
527 	 */
528 	name = device_get_nameunit(child);
529 	if (name == NULL) {
530 		name = "";
531 		suffix = "";
532 	} else
533 		suffix = " ";
534 	switch (type) {
535 	case SYS_RES_IOPORT:
536 		ok = 0;
537 		if (!pcib_is_io_open(sc))
538 			break;
539 		ok = (start >= sc->iobase && end <= sc->iolimit);
540 
541 		/*
542 		 * Make sure we allow access to VGA I/O addresses when the
543 		 * bridge has the "VGA Enable" bit set.
544 		 */
545 		if (!ok && pci_is_vga_ioport_range(start, end))
546 			ok = (sc->bridgectl & PCIB_BCR_VGA_ENABLE) ? 1 : 0;
547 
548 		if ((sc->flags & PCIB_SUBTRACTIVE) == 0) {
549 			if (!ok) {
550 				if (start < sc->iobase)
551 					start = sc->iobase;
552 				if (end > sc->iolimit)
553 					end = sc->iolimit;
554 				if (start < end)
555 					ok = 1;
556 			}
557 		} else {
558 			ok = 1;
559 #if 0
560 			/*
561 			 * If we overlap with the subtractive range, then
562 			 * pick the upper range to use.
563 			 */
564 			if (start < sc->iolimit && end > sc->iobase)
565 				start = sc->iolimit + 1;
566 #endif
567 		}
568 		if (end < start) {
569 			device_printf(dev, "ioport: end (%lx) < start (%lx)\n",
570 			    end, start);
571 			start = 0;
572 			end = 0;
573 			ok = 0;
574 		}
575 		if (!ok) {
576 			device_printf(dev, "%s%srequested unsupported I/O "
577 			    "range 0x%lx-0x%lx (decoding 0x%x-0x%x)\n",
578 			    name, suffix, start, end, sc->iobase, sc->iolimit);
579 			return (NULL);
580 		}
581 		if (bootverbose)
582 			device_printf(dev,
583 			    "%s%srequested I/O range 0x%lx-0x%lx: in range\n",
584 			    name, suffix, start, end);
585 		break;
586 
587 	case SYS_RES_MEMORY:
588 		ok = 0;
589 		if (pcib_is_nonprefetch_open(sc))
590 			ok = ok || (start >= sc->membase && end <= sc->memlimit);
591 		if (pcib_is_prefetch_open(sc))
592 			ok = ok || (start >= sc->pmembase && end <= sc->pmemlimit);
593 
594 		/*
595 		 * Make sure we allow access to VGA memory addresses when the
596 		 * bridge has the "VGA Enable" bit set.
597 		 */
598 		if (!ok && pci_is_vga_memory_range(start, end))
599 			ok = (sc->bridgectl & PCIB_BCR_VGA_ENABLE) ? 1 : 0;
600 
601 		if ((sc->flags & PCIB_SUBTRACTIVE) == 0) {
602 			if (!ok) {
603 				ok = 1;
604 				if (flags & RF_PREFETCHABLE) {
605 					if (pcib_is_prefetch_open(sc)) {
606 						if (start < sc->pmembase)
607 							start = sc->pmembase;
608 						if (end > sc->pmemlimit)
609 							end = sc->pmemlimit;
610 					} else {
611 						ok = 0;
612 					}
613 				} else {	/* non-prefetchable */
614 					if (pcib_is_nonprefetch_open(sc)) {
615 						if (start < sc->membase)
616 							start = sc->membase;
617 						if (end > sc->memlimit)
618 							end = sc->memlimit;
619 					} else {
620 						ok = 0;
621 					}
622 				}
623 			}
624 		} else if (!ok) {
625 			ok = 1;	/* subtractive bridge: always ok */
626 #if 0
627 			if (pcib_is_nonprefetch_open(sc)) {
628 				if (start < sc->memlimit && end > sc->membase)
629 					start = sc->memlimit + 1;
630 			}
631 			if (pcib_is_prefetch_open(sc)) {
632 				if (start < sc->pmemlimit && end > sc->pmembase)
633 					start = sc->pmemlimit + 1;
634 			}
635 #endif
636 		}
637 		if (end < start) {
638 			device_printf(dev, "memory: end (%lx) < start (%lx)\n",
639 			    end, start);
640 			start = 0;
641 			end = 0;
642 			ok = 0;
643 		}
644 		if (!ok && bootverbose)
645 			device_printf(dev,
646 			    "%s%srequested unsupported memory range %#lx-%#lx "
647 			    "(decoding %#jx-%#jx, %#jx-%#jx)\n",
648 			    name, suffix, start, end,
649 			    (uintmax_t)sc->membase, (uintmax_t)sc->memlimit,
650 			    (uintmax_t)sc->pmembase, (uintmax_t)sc->pmemlimit);
651 		if (!ok)
652 			return (NULL);
653 		if (bootverbose)
654 			device_printf(dev,"%s%srequested memory range "
655 			    "0x%lx-0x%lx: good\n",
656 			    name, suffix, start, end);
657 		break;
658 
659 	default:
660 		break;
661 	}
662 	/*
663 	 * Bridge is OK decoding this resource, so pass it up.
664 	 */
665 	return (bus_generic_alloc_resource(dev, child, type, rid, start, end,
666 	    count, flags));
667 }
668 
669 /*
670  * PCIB interface.
671  */
672 int
673 pcib_maxslots(device_t dev)
674 {
675     return(PCI_SLOTMAX);
676 }
677 
678 /*
679  * Since we are a child of a PCI bus, its parent must support the pcib interface.
680  */
681 uint32_t
682 pcib_read_config(device_t dev, u_int b, u_int s, u_int f, u_int reg, int width)
683 {
684     return(PCIB_READ_CONFIG(device_get_parent(device_get_parent(dev)), b, s, f, reg, width));
685 }
686 
687 void
688 pcib_write_config(device_t dev, u_int b, u_int s, u_int f, u_int reg, uint32_t val, int width)
689 {
690     PCIB_WRITE_CONFIG(device_get_parent(device_get_parent(dev)), b, s, f, reg, val, width);
691 }
692 
693 /*
694  * Route an interrupt across a PCI bridge.
695  */
696 int
697 pcib_route_interrupt(device_t pcib, device_t dev, int pin)
698 {
699     device_t	bus;
700     int		parent_intpin;
701     int		intnum;
702 
703     /*
704      *
705      * The PCI standard defines a swizzle of the child-side device/intpin to
706      * the parent-side intpin as follows.
707      *
708      * device = device on child bus
709      * child_intpin = intpin on child bus slot (0-3)
710      * parent_intpin = intpin on parent bus slot (0-3)
711      *
712      * parent_intpin = (device + child_intpin) % 4
713      */
714     parent_intpin = (pci_get_slot(dev) + (pin - 1)) % 4;
715 
716     /*
717      * Our parent is a PCI bus.  Its parent must export the pcib interface
718      * which includes the ability to route interrupts.
719      */
720     bus = device_get_parent(pcib);
721     intnum = PCIB_ROUTE_INTERRUPT(device_get_parent(bus), pcib, parent_intpin + 1);
722     if (PCI_INTERRUPT_VALID(intnum) && bootverbose) {
723 	device_printf(pcib, "slot %d INT%c is routed to irq %d\n",
724 	    pci_get_slot(dev), 'A' + pin - 1, intnum);
725     }
726     return(intnum);
727 }
728 
729 /* Pass request to alloc MSI/MSI-X messages up to the parent bridge. */
730 int
731 pcib_alloc_msi(device_t pcib, device_t dev, int count, int maxcount, int *irqs)
732 {
733 	struct pcib_softc *sc = device_get_softc(pcib);
734 	device_t bus;
735 
736 	if (sc->flags & PCIB_DISABLE_MSI)
737 		return (ENXIO);
738 	bus = device_get_parent(pcib);
739 	return (PCIB_ALLOC_MSI(device_get_parent(bus), dev, count, maxcount,
740 	    irqs));
741 }
742 
743 /* Pass request to release MSI/MSI-X messages up to the parent bridge. */
744 int
745 pcib_release_msi(device_t pcib, device_t dev, int count, int *irqs)
746 {
747 	device_t bus;
748 
749 	bus = device_get_parent(pcib);
750 	return (PCIB_RELEASE_MSI(device_get_parent(bus), dev, count, irqs));
751 }
752 
753 /* Pass request to alloc an MSI-X message up to the parent bridge. */
754 int
755 pcib_alloc_msix(device_t pcib, device_t dev, int *irq)
756 {
757 	struct pcib_softc *sc = device_get_softc(pcib);
758 	device_t bus;
759 
760 	if (sc->flags & PCIB_DISABLE_MSI)
761 		return (ENXIO);
762 	bus = device_get_parent(pcib);
763 	return (PCIB_ALLOC_MSIX(device_get_parent(bus), dev, irq));
764 }
765 
766 /* Pass request to release an MSI-X message up to the parent bridge. */
767 int
768 pcib_release_msix(device_t pcib, device_t dev, int irq)
769 {
770 	device_t bus;
771 
772 	bus = device_get_parent(pcib);
773 	return (PCIB_RELEASE_MSIX(device_get_parent(bus), dev, irq));
774 }
775 
776 /* Pass request to map MSI/MSI-X message up to parent bridge. */
777 int
778 pcib_map_msi(device_t pcib, device_t dev, int irq, uint64_t *addr,
779     uint32_t *data)
780 {
781 	device_t bus;
782 	int error;
783 
784 	bus = device_get_parent(pcib);
785 	error = PCIB_MAP_MSI(device_get_parent(bus), dev, irq, addr, data);
786 	if (error)
787 		return (error);
788 
789 	pci_ht_map_msi(pcib, *addr);
790 	return (0);
791 }
792 
793 /*
794  * Try to read the bus number of a host-PCI bridge using appropriate config
795  * registers.
796  */
797 int
798 host_pcib_get_busno(pci_read_config_fn read_config, int bus, int slot, int func,
799     uint8_t *busnum)
800 {
801 	uint32_t id;
802 
803 	id = read_config(bus, slot, func, PCIR_DEVVENDOR, 4);
804 	if (id == 0xffffffff)
805 		return (0);
806 
807 	switch (id) {
808 	case 0x12258086:
809 		/* Intel 824?? */
810 		/* XXX This is a guess */
811 		/* *busnum = read_config(bus, slot, func, 0x41, 1); */
812 		*busnum = bus;
813 		break;
814 	case 0x84c48086:
815 		/* Intel 82454KX/GX (Orion) */
816 		*busnum = read_config(bus, slot, func, 0x4a, 1);
817 		break;
818 	case 0x84ca8086:
819 		/*
820 		 * For the 450nx chipset, there is a whole bundle of
821 		 * things pretending to be host bridges. The MIOC will
822 		 * be seen first and isn't really a pci bridge (the
823 		 * actual busses are attached to the PXB's). We need to
824 		 * read the registers of the MIOC to figure out the
825 		 * bus numbers for the PXB channels.
826 		 *
827 		 * Since the MIOC doesn't have a pci bus attached, we
828 		 * pretend it wasn't there.
829 		 */
830 		return (0);
831 	case 0x84cb8086:
832 		switch (slot) {
833 		case 0x12:
834 			/* Intel 82454NX PXB#0, Bus#A */
835 			*busnum = read_config(bus, 0x10, func, 0xd0, 1);
836 			break;
837 		case 0x13:
838 			/* Intel 82454NX PXB#0, Bus#B */
839 			*busnum = read_config(bus, 0x10, func, 0xd1, 1) + 1;
840 			break;
841 		case 0x14:
842 			/* Intel 82454NX PXB#1, Bus#A */
843 			*busnum = read_config(bus, 0x10, func, 0xd3, 1);
844 			break;
845 		case 0x15:
846 			/* Intel 82454NX PXB#1, Bus#B */
847 			*busnum = read_config(bus, 0x10, func, 0xd4, 1) + 1;
848 			break;
849 		}
850 		break;
851 
852 		/* ServerWorks -- vendor 0x1166 */
853 	case 0x00051166:
854 	case 0x00061166:
855 	case 0x00081166:
856 	case 0x00091166:
857 	case 0x00101166:
858 	case 0x00111166:
859 	case 0x00171166:
860 	case 0x01011166:
861 	case 0x010f1014:
862 	case 0x02011166:
863 	case 0x03021014:
864 		*busnum = read_config(bus, slot, func, 0x44, 1);
865 		break;
866 
867 		/* Compaq/HP -- vendor 0x0e11 */
868 	case 0x60100e11:
869 		*busnum = read_config(bus, slot, func, 0xc8, 1);
870 		break;
871 	default:
872 		/* Don't know how to read bus number. */
873 		return 0;
874 	}
875 
876 	return 1;
877 }
878