xref: /netbsd-src/sys/dev/pci/pciconf.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: pciconf.c,v 1.31 2009/08/02 11:25:50 gavan Exp $	*/
2 
3 /*
4  * Copyright 2001 Wasabi Systems, Inc.
5  * All rights reserved.
6  *
7  * Written by Allen Briggs for Wasabi Systems, Inc.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *      This product includes software developed for the NetBSD Project by
20  *      Wasabi Systems, Inc.
21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22  *    or promote products derived from this software without specific prior
23  *    written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35  * POSSIBILITY OF SUCH DAMAGE.
36  */
37 /*
38  * Derived in part from code from PMON/2000 (http://pmon.groupbsd.org/).
39  */
40 
41 /*
42  * To do:
43  *    - Perform all data structure allocation dynamically, don't have
44  *	statically-sized arrays ("oops, you lose because you have too
45  *	many slots filled!")
46  *    - Do this in 2 passes, with an MD hook to control the behavior:
47  *		(1) Configure the bus (possibly including expansion
48  *		    ROMs.
49  *		(2) Another pass to disable expansion ROMs if they're
50  *		    mapped (since you're not supposed to leave them
51  *		    mapped when you're not using them).
52  *	This would facilitate MD code executing the expansion ROMs
53  *	if necessary (possibly with an x86 emulator) to configure
54  *	devices (e.g. VGA cards).
55  *    - Deal with "anything can be hot-plugged" -- i.e., carry configuration
56  *	information around & be able to reconfigure on the fly
57  *    - Deal with segments (See IA64 System Abstraction Layer)
58  *    - Deal with subtractive bridges (& non-spec positive/subtractive decode)
59  *    - Deal with ISA/VGA/VGA palette snooping
60  *    - Deal with device capabilities on bridges
61  *    - Worry about changing a bridge to/from transparency
62  * From thorpej (05/25/01)
63  *    - Try to handle devices that are already configured (perhaps using that
64  *      as a hint to where we put other devices)
65  */
66 
67 #include <sys/cdefs.h>
68 __KERNEL_RCSID(0, "$NetBSD: pciconf.c,v 1.31 2009/08/02 11:25:50 gavan Exp $");
69 
70 #include "opt_pci.h"
71 
72 #include <sys/param.h>
73 #include <sys/extent.h>
74 #include <sys/queue.h>
75 #include <sys/systm.h>
76 #include <sys/malloc.h>
77 
78 #include <dev/pci/pcivar.h>
79 #include <dev/pci/pciconf.h>
80 #include <dev/pci/pcidevs.h>
81 #include <dev/pci/pccbbreg.h>
82 
83 int pci_conf_debug = 0;
84 
85 #if !defined(MIN)
86 #define	MIN(a,b) (((a)<(b))?(a):(b))
87 #define	MAX(a,b) (((a)>(b))?(a):(b))
88 #endif
89 
90 /* per-bus constants. */
91 #define MAX_CONF_DEV	32			/* Arbitrary */
92 #define MAX_CONF_MEM	(3 * MAX_CONF_DEV)	/* Avg. 3 per device -- Arb. */
93 #define MAX_CONF_IO	(3 * MAX_CONF_DEV)	/* Avg. 1 per device -- Arb. */
94 
95 struct _s_pciconf_bus_t;			/* Forward declaration */
96 
97 typedef struct _s_pciconf_dev_t {
98 	int		ipin;
99 	int		iline;
100 	int		min_gnt;
101 	int		max_lat;
102 	int		enable;
103 	pcitag_t	tag;
104 	pci_chipset_tag_t	pc;
105 	struct _s_pciconf_bus_t	*ppb;		/* I am really a bridge */
106 } pciconf_dev_t;
107 
108 typedef struct _s_pciconf_win_t {
109 	pciconf_dev_t	*dev;
110 	int		reg;			/* 0 for busses */
111 	int		align;
112 	int		prefetch;
113 	u_int64_t	size;
114 	u_int64_t	address;
115 } pciconf_win_t;
116 
117 typedef struct _s_pciconf_bus_t {
118 	int		busno;
119 	int		next_busno;
120 	int		last_busno;
121 	int		max_mingnt;
122 	int		min_maxlat;
123 	int		cacheline_size;
124 	int		prefetch;
125 	int		fast_b2b;
126 	int		freq_66;
127 	int		def_ltim;
128 	int		max_ltim;
129 	int		bandwidth_used;
130 	int		swiz;
131 	int		io_32bit;
132 	int		pmem_64bit;
133 
134 	int		ndevs;
135 	pciconf_dev_t	device[MAX_CONF_DEV];
136 
137 	/* These should be sorted in order of decreasing size */
138 	int		nmemwin;
139 	pciconf_win_t	pcimemwin[MAX_CONF_MEM];
140 	int		niowin;
141 	pciconf_win_t	pciiowin[MAX_CONF_IO];
142 
143 	bus_size_t	io_total;
144 	bus_size_t	mem_total;
145 	bus_size_t	pmem_total;
146 
147 	struct extent	*ioext;
148 	struct extent	*memext;
149 	struct extent	*pmemext;
150 
151 	pci_chipset_tag_t	pc;
152 	struct _s_pciconf_bus_t *parent_bus;
153 } pciconf_bus_t;
154 
155 static int	probe_bus(pciconf_bus_t *);
156 static void	alloc_busno(pciconf_bus_t *, pciconf_bus_t *);
157 static void	set_busreg(pci_chipset_tag_t, pcitag_t, int, int, int);
158 static int	pci_do_device_query(pciconf_bus_t *, pcitag_t, int, int, int);
159 static int	setup_iowins(pciconf_bus_t *);
160 static int	setup_memwins(pciconf_bus_t *);
161 static int	configure_bridge(pciconf_dev_t *);
162 static int	configure_bus(pciconf_bus_t *);
163 static u_int64_t	pci_allocate_range(struct extent *, u_int64_t, int);
164 static pciconf_win_t	*get_io_desc(pciconf_bus_t *, bus_size_t);
165 static pciconf_win_t	*get_mem_desc(pciconf_bus_t *, bus_size_t);
166 static pciconf_bus_t	*query_bus(pciconf_bus_t *, pciconf_dev_t *, int);
167 
168 static void	print_tag(pci_chipset_tag_t, pcitag_t);
169 
170 static void
171 print_tag(pci_chipset_tag_t pc, pcitag_t tag)
172 {
173 	int	bus, dev, func;
174 
175 	pci_decompose_tag(pc, tag, &bus, &dev, &func);
176 	printf("PCI: bus %d, device %d, function %d: ", bus, dev, func);
177 }
178 
179 /************************************************************************/
180 /************************************************************************/
181 /***********************   Bus probing routines   ***********************/
182 /************************************************************************/
183 /************************************************************************/
184 static pciconf_win_t *
185 get_io_desc(pciconf_bus_t *pb, bus_size_t size)
186 {
187 	int	i, n;
188 
189 	n = pb->niowin;
190 	for (i=n; i > 0 && size > pb->pciiowin[i-1].size; i--)
191 		pb->pciiowin[i] = pb->pciiowin[i-1]; /* struct copy */
192 	return &pb->pciiowin[i];
193 }
194 
195 static pciconf_win_t *
196 get_mem_desc(pciconf_bus_t *pb, bus_size_t size)
197 {
198 	int	i, n;
199 
200 	n = pb->nmemwin;
201 	for (i=n; i > 0 && size > pb->pcimemwin[i-1].size; i--)
202 		pb->pcimemwin[i] = pb->pcimemwin[i-1]; /* struct copy */
203 	return &pb->pcimemwin[i];
204 }
205 
206 /*
207  * Set up bus common stuff, then loop over devices & functions.
208  * If we find something, call pci_do_device_query()).
209  */
210 static int
211 probe_bus(pciconf_bus_t *pb)
212 {
213 	int device, maxdevs;
214 #ifdef __PCI_BUS_DEVORDER
215 	char devs[32];
216 	int  i;
217 #endif
218 
219 	maxdevs = pci_bus_maxdevs(pb->pc, pb->busno);
220 	pb->ndevs = 0;
221 	pb->niowin = 0;
222 	pb->nmemwin = 0;
223 	pb->freq_66 = 1;
224 #ifdef PCICONF_NO_FAST_B2B
225 	pb->fast_b2b = 0;
226 #else
227 	pb->fast_b2b = 1;
228 #endif
229 	pb->prefetch = 1;
230 	pb->max_mingnt = 0;	/* we are looking for the maximum */
231 	pb->min_maxlat = 0x100;	/* we are looking for the minimum */
232 	pb->bandwidth_used = 0;
233 
234 #ifdef __PCI_BUS_DEVORDER
235 	pci_bus_devorder(pb->pc, pb->busno, devs);
236 	for (i = 0; (device = devs[i]) < 32 && device >= 0; i++) {
237 #else
238 	for (device = 0; device < maxdevs; device++) {
239 #endif
240 		pcitag_t tag;
241 		pcireg_t id, bhlcr;
242 		int function, nfunction;
243 		int confmode;
244 
245 		tag = pci_make_tag(pb->pc, pb->busno, device, 0);
246 		if (pci_conf_debug) {
247 			print_tag(pb->pc, tag);
248 		}
249 		id = pci_conf_read(pb->pc, tag, PCI_ID_REG);
250 
251 		if (pci_conf_debug) {
252 			printf("id=%x: Vendor=%x, Product=%x\n",
253 			    id, PCI_VENDOR(id),PCI_PRODUCT(id));
254 		}
255 		/* Invalid vendor ID value? */
256 		if (PCI_VENDOR(id) == PCI_VENDOR_INVALID)
257 			continue;
258 
259 		bhlcr = pci_conf_read(pb->pc, tag, PCI_BHLC_REG);
260 		nfunction = PCI_HDRTYPE_MULTIFN(bhlcr) ? 8 : 1;
261 		for (function = 0 ; function < nfunction ; function++) {
262 			tag = pci_make_tag(pb->pc, pb->busno, device, function);
263 			id = pci_conf_read(pb->pc, tag, PCI_ID_REG);
264 			if (PCI_VENDOR(id) == PCI_VENDOR_INVALID)
265 				continue;
266 			if (pb->ndevs+1 < MAX_CONF_DEV) {
267 				if (pci_conf_debug) {
268 					print_tag(pb->pc, tag);
269 					printf("Found dev 0x%04x 0x%04x -- "
270 					    "really probing.\n",
271 					PCI_VENDOR(id), PCI_PRODUCT(id));
272 				}
273 #ifdef __HAVE_PCI_CONF_HOOK
274 				confmode = pci_conf_hook(pb->pc, pb->busno,
275 				    device, function, id);
276 				if (confmode == 0)
277 					continue;
278 #else
279 				/*
280 				 * Don't enable expansion ROMS -- some cards
281 				 * share address decoders between the EXPROM
282 				 * and PCI memory space, and enabling the ROM
283 				 * when not needed will cause all sorts of
284 				 * lossage.
285 				 */
286 				confmode = PCI_CONF_DEFAULT;
287 #endif
288 				if (pci_do_device_query(pb, tag, device,
289 				    function, confmode))
290 					return -1;
291 				pb->ndevs++;
292 			}
293 		}
294 	}
295 	return 0;
296 }
297 
298 static void
299 alloc_busno(pciconf_bus_t *parent, pciconf_bus_t *pb)
300 {
301 	pb->busno = parent->next_busno;
302 	pb->next_busno = pb->busno + 1;
303 }
304 
305 static void
306 set_busreg(pci_chipset_tag_t pc, pcitag_t tag, int prim, int sec, int sub)
307 {
308 	pcireg_t	busreg;
309 
310 	busreg  =  prim << PCI_BRIDGE_BUS_PRIMARY_SHIFT;
311 	busreg |=   sec << PCI_BRIDGE_BUS_SECONDARY_SHIFT;
312 	busreg |=   sub << PCI_BRIDGE_BUS_SUBORDINATE_SHIFT;
313 	pci_conf_write(pc, tag, PCI_BRIDGE_BUS_REG, busreg);
314 }
315 
316 static pciconf_bus_t *
317 query_bus(pciconf_bus_t *parent, pciconf_dev_t *pd, int dev)
318 {
319 	pciconf_bus_t	*pb;
320 	pcireg_t	io, pmem;
321 	pciconf_win_t	*pi, *pm;
322 
323 	pb = malloc (sizeof (pciconf_bus_t), M_DEVBUF, M_NOWAIT);
324 	if (!pb)
325 		panic("Unable to allocate memory for PCI configuration.");
326 
327 	pb->cacheline_size = parent->cacheline_size;
328 	pb->parent_bus = parent;
329 	alloc_busno(parent, pb);
330 
331 	set_busreg(parent->pc, pd->tag, parent->busno, pb->busno, 0xff);
332 
333 	pb->swiz = parent->swiz + dev;
334 
335 	pb->ioext = NULL;
336 	pb->memext = NULL;
337 	pb->pmemext = NULL;
338 	pb->pc = parent->pc;
339 	pb->io_total = pb->mem_total = pb->pmem_total = 0;
340 
341 	pb->io_32bit = 0;
342 	if (parent->io_32bit) {
343 		io = pci_conf_read(parent->pc, pd->tag, PCI_BRIDGE_STATIO_REG);
344 		if (PCI_BRIDGE_IO_32BITS(io)) {
345 			pb->io_32bit = 1;
346 		}
347 	}
348 
349 	pb->pmem_64bit = 0;
350 	if (parent->pmem_64bit) {
351 		pmem = pci_conf_read(parent->pc, pd->tag,
352 		    PCI_BRIDGE_PREFETCHMEM_REG);
353 		if (PCI_BRIDGE_PREFETCHMEM_64BITS(pmem)) {
354 			pb->pmem_64bit = 1;
355 		}
356 	}
357 
358 	if (probe_bus(pb)) {
359 		printf("Failed to probe bus %d\n", pb->busno);
360 		goto err;
361 	}
362 
363 	/* We have found all subordinate busses now, reprogram busreg. */
364 	pb->last_busno = pb->next_busno-1;
365 	parent->next_busno = pb->next_busno;
366 	set_busreg(parent->pc, pd->tag, parent->busno, pb->busno,
367 		   pb->last_busno);
368 	if (pci_conf_debug)
369 		printf("PCI bus bridge (parent %d) covers busses %d-%d\n",
370 			parent->busno, pb->busno, pb->last_busno);
371 
372 	if (pb->io_total > 0) {
373 		if (parent->niowin >= MAX_CONF_IO) {
374 			printf("pciconf: too many I/O windows\n");
375 			goto err;
376 		}
377 		pb->io_total |= 0xfff;	/* Round up */
378 		pi = get_io_desc(parent, pb->io_total);
379 		pi->dev = pd;
380 		pi->reg = 0;
381 		pi->size = pb->io_total;
382 		pi->align = 0x1000;	/* 4K alignment */
383 		pi->prefetch = 0;
384 		parent->niowin++;
385 		parent->io_total += pb->io_total;
386 	}
387 
388 	if (pb->mem_total > 0) {
389 		if (parent->nmemwin >= MAX_CONF_MEM) {
390 			printf("pciconf: too many MEM windows\n");
391 			goto err;
392 		}
393 		pb->mem_total |= 0xfffff;	/* Round up */
394 		pm = get_mem_desc(parent, pb->mem_total);
395 		pm->dev = pd;
396 		pm->reg = 0;
397 		pm->size = pb->mem_total;
398 		pm->align = 0x100000;	/* 1M alignment */
399 		pm->prefetch = 0;
400 		parent->nmemwin++;
401 		parent->mem_total += pb->mem_total;
402 	}
403 
404 	if (pb->pmem_total > 0) {
405 		if (parent->nmemwin >= MAX_CONF_MEM) {
406 			printf("pciconf: too many MEM windows\n");
407 			goto err;
408 		}
409 		pb->pmem_total |= 0xfffff;	/* Round up */
410 		pm = get_mem_desc(parent, pb->pmem_total);
411 		pm->dev = pd;
412 		pm->reg = 0;
413 		pm->size = pb->pmem_total;
414 		pm->align = 0x100000;		/* 1M alignment */
415 		pm->prefetch = 1;
416 		parent->nmemwin++;
417 		parent->pmem_total += pb->pmem_total;
418 	}
419 
420 	return pb;
421 err:
422 	free(pb, M_DEVBUF);
423 	return NULL;
424 }
425 
426 static int
427 pci_do_device_query(pciconf_bus_t *pb, pcitag_t tag, int dev, int func, int mode)
428 {
429 	pciconf_dev_t	*pd;
430 	pciconf_win_t	*pi, *pm;
431 	pcireg_t	class, cmd, icr, bhlc, bar, mask, bar64, mask64, busreg;
432 	u_int64_t	size;
433 	int		br, width, reg_start, reg_end;
434 
435 	pd = &pb->device[pb->ndevs];
436 	pd->pc = pb->pc;
437 	pd->tag = tag;
438 	pd->ppb = NULL;
439 	pd->enable = mode;
440 
441 	class = pci_conf_read(pb->pc, tag, PCI_CLASS_REG);
442 
443 	cmd = pci_conf_read(pb->pc, tag, PCI_COMMAND_STATUS_REG);
444 
445 	if (PCI_CLASS(class) != PCI_CLASS_BRIDGE) {
446 		cmd &= ~(PCI_COMMAND_MASTER_ENABLE |
447 		    PCI_COMMAND_IO_ENABLE | PCI_COMMAND_MEM_ENABLE);
448 		pci_conf_write(pb->pc, tag, PCI_COMMAND_STATUS_REG, cmd);
449 	} else if (pci_conf_debug) {
450 		print_tag(pb->pc, tag);
451 		printf("device is a bridge; not clearing enables\n");
452 	}
453 
454 	if ((cmd & PCI_STATUS_BACKTOBACK_SUPPORT) == 0)
455 		pb->fast_b2b = 0;
456 
457 	if ((cmd & PCI_STATUS_66MHZ_SUPPORT) == 0)
458 		pb->freq_66 = 0;
459 
460 	bhlc = pci_conf_read(pb->pc, tag, PCI_BHLC_REG);
461 	switch (PCI_HDRTYPE_TYPE(bhlc)) {
462 	case PCI_HDRTYPE_DEVICE:
463 		reg_start = PCI_MAPREG_START;
464 		reg_end = PCI_MAPREG_END;
465 		break;
466 	case PCI_HDRTYPE_PPB:
467 		pd->ppb = query_bus(pb, pd, dev);
468 		if (pd->ppb == NULL)
469 			return -1;
470 		return 0;
471 	case PCI_HDRTYPE_PCB:
472 		reg_start = PCI_MAPREG_START;
473 		reg_end = PCI_MAPREG_PCB_END;
474 
475 		busreg = pci_conf_read(pb->pc, tag, PCI_BUSNUM);
476 		busreg  =  (busreg & 0xff000000) |
477 		    pb->busno << PCI_BRIDGE_BUS_PRIMARY_SHIFT |
478 		    pb->next_busno << PCI_BRIDGE_BUS_SECONDARY_SHIFT |
479 		    pb->next_busno << PCI_BRIDGE_BUS_SUBORDINATE_SHIFT;
480 		pci_conf_write(pb->pc, tag, PCI_BUSNUM, busreg);
481 
482 		pb->next_busno++;
483 		break;
484 	default:
485 		return -1;
486 	}
487 
488 	icr = pci_conf_read(pb->pc, tag, PCI_INTERRUPT_REG);
489 	pd->ipin = PCI_INTERRUPT_PIN(icr);
490 	pd->iline = PCI_INTERRUPT_LINE(icr);
491 	pd->min_gnt = PCI_MIN_GNT(icr);
492 	pd->max_lat = PCI_MAX_LAT(icr);
493 	if (pd->iline || pd->ipin) {
494 		pci_conf_interrupt(pb->pc, pb->busno, dev, pd->ipin, pb->swiz,
495 		    &pd->iline);
496 		icr &= ~(PCI_INTERRUPT_LINE_MASK << PCI_INTERRUPT_LINE_SHIFT);
497 		icr |= (pd->iline << PCI_INTERRUPT_LINE_SHIFT);
498 		pci_conf_write(pb->pc, tag, PCI_INTERRUPT_REG, icr);
499 	}
500 
501 	if (pd->min_gnt != 0 || pd->max_lat != 0) {
502 		if (pd->min_gnt != 0 && pd->min_gnt > pb->max_mingnt)
503 			pb->max_mingnt = pd->min_gnt;
504 
505 		if (pd->max_lat != 0 && pd->max_lat < pb->min_maxlat)
506 			pb->min_maxlat = pd->max_lat;
507 
508 		pb->bandwidth_used += pd->min_gnt * 4000000 /
509 				(pd->min_gnt + pd->max_lat);
510 	}
511 
512 	width = 4;
513 	for (br = reg_start; br < reg_end; br += width) {
514 #if 0
515 /* XXX Should only ignore if IDE not in legacy mode? */
516 		if (PCI_CLASS(class) == PCI_CLASS_MASS_STORAGE &&
517 		    PCI_SUBCLASS(class) == PCI_SUBCLASS_MASS_STORAGE_IDE) {
518 			break;
519 		}
520 #endif
521 		bar = pci_conf_read(pb->pc, tag, br);
522 		pci_conf_write(pb->pc, tag, br, 0xffffffff);
523 		mask = pci_conf_read(pb->pc, tag, br);
524 		pci_conf_write(pb->pc, tag, br, bar);
525 		width = 4;
526 
527 		if (   (mode & PCI_CONF_MAP_IO)
528 		    && (PCI_MAPREG_TYPE(mask) == PCI_MAPREG_TYPE_IO)) {
529 			/*
530 			 * Upper 16 bits must be one.  Devices may hardwire
531 			 * them to zero, though, per PCI 2.2, 6.2.5.1, p 203.
532 			 */
533 			mask |= 0xffff0000;
534 
535 			size = PCI_MAPREG_IO_SIZE(mask);
536 			if (size == 0) {
537 				if (pci_conf_debug) {
538 					print_tag(pb->pc, tag);
539 					printf("I/O BAR 0x%x is void\n", br);
540 				}
541 				continue;
542 			}
543 
544 			if (pb->niowin >= MAX_CONF_IO) {
545 				printf("pciconf: too many I/O windows\n");
546 				return -1;
547 			}
548 
549 			pi = get_io_desc(pb, size);
550 			pi->dev = pd;
551 			pi->reg = br;
552 			pi->size = (u_int64_t) size;
553 			pi->align = 4;
554 			pi->prefetch = 0;
555 			if (pci_conf_debug) {
556 				print_tag(pb->pc, tag);
557 				printf("Register 0x%x, I/O size %" PRIu64 "\n",
558 				    br, pi->size);
559 			}
560 			pb->niowin++;
561 			pb->io_total += size;
562 		} else if ((mode & PCI_CONF_MAP_MEM)
563 			   && (PCI_MAPREG_TYPE(mask) == PCI_MAPREG_TYPE_MEM)) {
564 			switch (PCI_MAPREG_MEM_TYPE(mask)) {
565 			case PCI_MAPREG_MEM_TYPE_32BIT:
566 			case PCI_MAPREG_MEM_TYPE_32BIT_1M:
567 				size = (u_int64_t) PCI_MAPREG_MEM_SIZE(mask);
568 				break;
569 			case PCI_MAPREG_MEM_TYPE_64BIT:
570 				bar64 = pci_conf_read(pb->pc, tag, br + 4);
571 				pci_conf_write(pb->pc, tag, br + 4, 0xffffffff);
572 				mask64 = pci_conf_read(pb->pc, tag, br + 4);
573 				pci_conf_write(pb->pc, tag, br + 4, bar64);
574 				size = (u_int64_t) PCI_MAPREG_MEM64_SIZE(
575 				      (((u_int64_t) mask64) << 32) | mask);
576 				width = 8;
577 				break;
578 			default:
579 				print_tag(pb->pc, tag);
580 				printf("reserved mapping type 0x%x\n",
581 					PCI_MAPREG_MEM_TYPE(mask));
582 				continue;
583 			}
584 
585 			if (size == 0) {
586 				if (pci_conf_debug) {
587 					print_tag(pb->pc, tag);
588 					printf("MEM%d BAR 0x%x is void\n",
589 					    PCI_MAPREG_MEM_TYPE(mask) ==
590 						PCI_MAPREG_MEM_TYPE_64BIT ?
591 						64 : 32, br);
592 				}
593 				continue;
594 			} else {
595 				if (pci_conf_debug) {
596 					print_tag(pb->pc, tag);
597 					printf("MEM%d BAR 0x%x has size %lx\n",
598 					    PCI_MAPREG_MEM_TYPE(mask) ==
599 						PCI_MAPREG_MEM_TYPE_64BIT ?
600 						64 : 32, br, (unsigned long)size);
601 				}
602 			}
603 
604 			if (pb->nmemwin >= MAX_CONF_MEM) {
605 				printf("pciconf: too many memory windows\n");
606 				return -1;
607 			}
608 
609 			pm = get_mem_desc(pb, size);
610 			pm->dev = pd;
611 			pm->reg = br;
612 			pm->size = size;
613 			pm->align = 4;
614 			pm->prefetch = PCI_MAPREG_MEM_PREFETCHABLE(mask);
615 			if (pci_conf_debug) {
616 				print_tag(pb->pc, tag);
617 				printf("Register 0x%x, memory size %"
618 				    PRIu64 "\n", br, pm->size);
619 			}
620 			pb->nmemwin++;
621 			if (pm->prefetch) {
622 				pb->pmem_total += size;
623 			} else {
624 				pb->mem_total += size;
625 			}
626 		}
627 	}
628 
629 	if (mode & PCI_CONF_MAP_ROM) {
630 		bar = pci_conf_read(pb->pc, tag, PCI_MAPREG_ROM);
631 		pci_conf_write(pb->pc, tag, PCI_MAPREG_ROM, 0xfffffffe);
632 		mask = pci_conf_read(pb->pc, tag, PCI_MAPREG_ROM);
633 		pci_conf_write(pb->pc, tag, PCI_MAPREG_ROM, bar);
634 
635 		if (mask != 0 && mask != 0xffffffff) {
636 			if (pb->nmemwin >= MAX_CONF_MEM) {
637 				printf("pciconf: too many memory windows\n");
638 				return -1;
639 			}
640 			size = (u_int64_t) PCI_MAPREG_MEM_SIZE(mask);
641 
642 			pm = get_mem_desc(pb, size);
643 			pm->dev = pd;
644 			pm->reg = PCI_MAPREG_ROM;
645 			pm->size = size;
646 			pm->align = 4;
647 			pm->prefetch = 1;
648 			if (pci_conf_debug) {
649 				print_tag(pb->pc, tag);
650 				printf("Expansion ROM memory size %"
651 				    PRIu64 "\n", pm->size);
652 			}
653 			pb->nmemwin++;
654 			pb->pmem_total += size;
655 		}
656 	} else {
657 		/* Don't enable ROMs if we aren't going to map them. */
658 		mode &= ~PCI_CONF_ENABLE_ROM;
659 		pd->enable &= ~PCI_CONF_ENABLE_ROM;
660 	}
661 
662 	if (!(mode & PCI_CONF_ENABLE_ROM)) {
663 		/* Ensure ROM is disabled */
664 		bar = pci_conf_read(pb->pc, tag, PCI_MAPREG_ROM);
665 		pci_conf_write(pb->pc, tag, PCI_MAPREG_ROM,
666 		    bar & ~PCI_MAPREG_ROM_ENABLE);
667 	}
668 
669 	return 0;
670 }
671 
672 /************************************************************************/
673 /************************************************************************/
674 /********************   Bus configuration routines   ********************/
675 /************************************************************************/
676 /************************************************************************/
677 static u_int64_t
678 pci_allocate_range(struct extent *ex, u_int64_t amt, int align)
679 {
680 	int	r;
681 	u_long	addr;
682 
683 	r = extent_alloc(ex, amt, align, 0, EX_NOWAIT, &addr);
684 	if (r) {
685 		addr = (u_long) -1;
686 		printf("extent_alloc(%p, %" PRIu64 ", %d) returned %d\n",
687 		    ex, amt, align, r);
688 		extent_print(ex);
689 	}
690 	return (pcireg_t) addr;
691 }
692 
693 static int
694 setup_iowins(pciconf_bus_t *pb)
695 {
696 	pciconf_win_t	*pi;
697 	pciconf_dev_t	*pd;
698 
699 	for (pi=pb->pciiowin; pi < &pb->pciiowin[pb->niowin] ; pi++) {
700 		if (pi->size == 0)
701 			continue;
702 
703 		pd = pi->dev;
704 		pi->address = pci_allocate_range(pb->ioext, pi->size,
705 		    pi->align);
706 		if (pi->address == -1) {
707 			print_tag(pd->pc, pd->tag);
708 			printf("Failed to allocate PCI I/O space (%"
709 			    PRIu64 " req)\n", pi->size);
710 			return -1;
711 		}
712 		if (pd->ppb && pi->reg == 0) {
713 			pd->ppb->ioext = extent_create("pciconf", pi->address,
714 			    pi->address + pi->size, M_DEVBUF, NULL, 0,
715 			    EX_NOWAIT);
716 			if (pd->ppb->ioext == NULL) {
717 				print_tag(pd->pc, pd->tag);
718 				printf("Failed to alloc I/O ext. for bus %d\n",
719 				    pd->ppb->busno);
720 				return -1;
721 			}
722 			continue;
723 		}
724 		if (!pb->io_32bit && pi->address > 0xFFFF) {
725 			pi->address = 0;
726 			pd->enable &= ~PCI_CONF_ENABLE_IO;
727 		} else {
728 			pd->enable |= PCI_CONF_ENABLE_IO;
729 		}
730 		if (pci_conf_debug) {
731 			print_tag(pd->pc, pd->tag);
732 			printf("Putting %" PRIu64 " I/O bytes @ %#" PRIx64
733 			    " (reg %x)\n", pi->size, pi->address, pi->reg);
734 		}
735 		pci_conf_write(pd->pc, pd->tag, pi->reg,
736 		    PCI_MAPREG_IO_ADDR(pi->address) | PCI_MAPREG_TYPE_IO);
737 	}
738 	return 0;
739 }
740 
741 static int
742 setup_memwins(pciconf_bus_t *pb)
743 {
744 	pciconf_win_t	*pm;
745 	pciconf_dev_t	*pd;
746 	pcireg_t	base;
747 	struct extent	*ex;
748 
749 	for (pm=pb->pcimemwin; pm < &pb->pcimemwin[pb->nmemwin] ; pm++) {
750 		if (pm->size == 0)
751 			continue;
752 
753 		pd = pm->dev;
754 		ex = (pm->prefetch) ? pb->pmemext : pb->memext;
755 		pm->address = pci_allocate_range(ex, pm->size, pm->align);
756 		if (pm->address == -1) {
757 			print_tag(pd->pc, pd->tag);
758 			printf(
759 			   "Failed to allocate PCI memory space (%" PRIu64
760 			   " req)\n", pm->size);
761 			return -1;
762 		}
763 		if (pd->ppb && pm->reg == 0) {
764 			ex = extent_create("pciconf", pm->address,
765 			    pm->address + pm->size, M_DEVBUF, NULL, 0,
766 			    EX_NOWAIT);
767 			if (ex == NULL) {
768 				print_tag(pd->pc, pd->tag);
769 				printf("Failed to alloc MEM ext. for bus %d\n",
770 				    pd->ppb->busno);
771 				return -1;
772 			}
773 			if (pm->prefetch) {
774 				pd->ppb->pmemext = ex;
775 			} else {
776 				pd->ppb->memext = ex;
777 			}
778 			continue;
779 		}
780 		if (pm->prefetch && !pb->pmem_64bit &&
781 		    pm->address > 0xFFFFFFFFULL) {
782 			pm->address = 0;
783 			pd->enable &= ~PCI_CONF_ENABLE_MEM;
784 		} else {
785 			pd->enable |= PCI_CONF_ENABLE_MEM;
786 		}
787 		if (pm->reg != PCI_MAPREG_ROM) {
788 			if (pci_conf_debug) {
789 				print_tag(pd->pc, pd->tag);
790 				printf(
791 				    "Putting %" PRIu64 " MEM bytes @ %#"
792 				    PRIx64 " (reg %x)\n", pm->size,
793 				    pm->address, pm->reg);
794 			}
795 			base = pci_conf_read(pd->pc, pd->tag, pm->reg);
796 			base = PCI_MAPREG_MEM_ADDR(pm->address) |
797 			    PCI_MAPREG_MEM_TYPE(base);
798 			pci_conf_write(pd->pc, pd->tag, pm->reg, base);
799 			if (PCI_MAPREG_MEM_TYPE(base) ==
800 			    PCI_MAPREG_MEM_TYPE_64BIT) {
801 				base = (pcireg_t)
802 				    (PCI_MAPREG_MEM64_ADDR(pm->address) >> 32);
803 				pci_conf_write(pd->pc, pd->tag, pm->reg + 4,
804 				    base);
805 			}
806 		}
807 	}
808 	for (pm=pb->pcimemwin; pm < &pb->pcimemwin[pb->nmemwin] ; pm++) {
809 		if (pm->reg == PCI_MAPREG_ROM && pm->address != -1) {
810 			pd = pm->dev;
811 			if (!(pd->enable & PCI_CONF_MAP_ROM))
812 				continue;
813 			if (pci_conf_debug) {
814 				print_tag(pd->pc, pd->tag);
815 				printf(
816 				    "Putting %" PRIu64 " ROM bytes @ %#"
817 				    PRIx64 " (reg %x)\n", pm->size,
818 				    pm->address, pm->reg);
819 			}
820 			base = (pcireg_t) pm->address;
821 			if (pd->enable & PCI_CONF_ENABLE_ROM)
822 				base |= PCI_MAPREG_ROM_ENABLE;
823 
824 			pci_conf_write(pd->pc, pd->tag, pm->reg, base);
825 		}
826 	}
827 	return 0;
828 }
829 
830 /*
831  * Configure I/O, memory, and prefetcable memory spaces, then make
832  * a call to configure_bus().
833  */
834 static int
835 configure_bridge(pciconf_dev_t *pd)
836 {
837 	unsigned long	io_base, io_limit, mem_base, mem_limit;
838 	pciconf_bus_t	*pb;
839 	pcireg_t	io, iohigh, mem, cmd;
840 	int		rv;
841 
842 	pb = pd->ppb;
843 	/* Configure I/O base & limit*/
844 	if (pb->ioext) {
845 		io_base = pb->ioext->ex_start;
846 		io_limit = pb->ioext->ex_end;
847 	} else {
848 		io_base  = 0x1000;	/* 4K */
849 		io_limit = 0x0000;
850 	}
851 	if (pb->io_32bit) {
852 		iohigh =
853 		    ((io_base >> 16) << PCI_BRIDGE_IOHIGH_BASE_SHIFT) |
854 		    ((io_limit >> 16) << PCI_BRIDGE_IOHIGH_LIMIT_SHIFT);
855 	} else {
856 		if (io_limit > 0xFFFF) {
857 			printf("Bus %d bridge does not support 32-bit I/O.  ",
858 			    pb->busno);
859 			printf("Disabling I/O accesses\n");
860 			io_base  = 0x1000;	/* 4K */
861 			io_limit = 0x0000;
862 		}
863 		iohigh = 0;
864 	}
865 	io = pci_conf_read(pb->pc, pd->tag, PCI_BRIDGE_STATIO_REG) &
866 	    (PCI_BRIDGE_STATIO_STATUS_MASK << PCI_BRIDGE_STATIO_STATUS_SHIFT);
867 	io |= (((io_base >> 8) & PCI_BRIDGE_STATIO_IOBASE_MASK)
868 	    << PCI_BRIDGE_STATIO_IOBASE_SHIFT);
869 	io |= (((io_limit >> 8) & PCI_BRIDGE_STATIO_IOLIMIT_MASK)
870 	    << PCI_BRIDGE_STATIO_IOLIMIT_SHIFT);
871 	pci_conf_write(pb->pc, pd->tag, PCI_BRIDGE_STATIO_REG, io);
872 	pci_conf_write(pb->pc, pd->tag, PCI_BRIDGE_IOHIGH_REG, iohigh);
873 
874 	/* Configure mem base & limit */
875 	if (pb->memext) {
876 		mem_base = pb->memext->ex_start;
877 		mem_limit = pb->memext->ex_end;
878 	} else {
879 		mem_base  = 0x100000;	/* 1M */
880 		mem_limit = 0x000000;
881 	}
882 #if ULONG_MAX > 0xffffffff
883 	if (mem_limit > 0xFFFFFFFFULL) {
884 		printf("Bus %d bridge MEM range out of range.  ", pb->busno);
885 		printf("Disabling MEM accesses\n");
886 		mem_base  = 0x100000;	/* 1M */
887 		mem_limit = 0x000000;
888 	}
889 #endif
890 	mem = (((mem_base >> 20) & PCI_BRIDGE_MEMORY_BASE_MASK)
891 	    << PCI_BRIDGE_MEMORY_BASE_SHIFT);
892 	mem |= (((mem_limit >> 20) & PCI_BRIDGE_MEMORY_LIMIT_MASK)
893 	    << PCI_BRIDGE_MEMORY_LIMIT_SHIFT);
894 	pci_conf_write(pb->pc, pd->tag, PCI_BRIDGE_MEMORY_REG, mem);
895 
896 	/* Configure prefetchable mem base & limit */
897 	if (pb->pmemext) {
898 		mem_base = pb->pmemext->ex_start;
899 		mem_limit = pb->pmemext->ex_end;
900 	} else {
901 		mem_base  = 0x100000;	/* 1M */
902 		mem_limit = 0x000000;
903 	}
904 	mem = pci_conf_read(pb->pc, pd->tag, PCI_BRIDGE_PREFETCHMEM_REG);
905 #if ULONG_MAX > 0xffffffff
906 	if (!PCI_BRIDGE_PREFETCHMEM_64BITS(mem) && mem_limit > 0xFFFFFFFFULL) {
907 		printf("Bus %d bridge does not support 64-bit PMEM.  ",
908 		    pb->busno);
909 		printf("Disabling prefetchable-MEM accesses\n");
910 		mem_base  = 0x100000;	/* 1M */
911 		mem_limit = 0x000000;
912 	}
913 #endif
914 	mem = (((mem_base >> 20) & PCI_BRIDGE_PREFETCHMEM_BASE_MASK)
915 	    << PCI_BRIDGE_PREFETCHMEM_BASE_SHIFT);
916 	mem |= (((mem_limit >> 20) & PCI_BRIDGE_PREFETCHMEM_LIMIT_MASK)
917 	    << PCI_BRIDGE_PREFETCHMEM_LIMIT_SHIFT);
918 	pci_conf_write(pb->pc, pd->tag, PCI_BRIDGE_PREFETCHMEM_REG, mem);
919 	/*
920 	 * XXX -- 64-bit systems need a lot more than just this...
921 	 */
922 	if (sizeof(u_long) > 4) {
923 		mem_base  = (int64_t) mem_base  >> 32;
924 		mem_limit = (int64_t) mem_limit >> 32;
925 	}
926 	pci_conf_write(pb->pc, pd->tag, PCI_BRIDGE_PREFETCHBASE32_REG,
927 	    mem_base & 0xffffffff);
928 	pci_conf_write(pb->pc, pd->tag, PCI_BRIDGE_PREFETCHLIMIT32_REG,
929 	    mem_limit & 0xffffffff);
930 
931 	rv = configure_bus(pb);
932 
933 	if (pb->ioext)
934 		extent_destroy(pb->ioext);
935 	if (pb->memext)
936 		extent_destroy(pb->memext);
937 	if (pb->pmemext)
938 		extent_destroy(pb->pmemext);
939 	if (rv == 0) {
940 		cmd = pci_conf_read(pd->pc, pd->tag, PCI_BRIDGE_CONTROL_REG);
941 		cmd &= PCI_BRIDGE_CONTROL_MASK;
942 		cmd |= (PCI_BRIDGE_CONTROL_PERE | PCI_BRIDGE_CONTROL_SERR)
943 		    << PCI_BRIDGE_CONTROL_SHIFT;
944 		if (pb->fast_b2b) {
945 			cmd |= PCI_BRIDGE_CONTROL_SECFASTB2B
946 			    << PCI_BRIDGE_CONTROL_SHIFT;
947 		}
948 		pci_conf_write(pd->pc, pd->tag, PCI_BRIDGE_CONTROL_REG, cmd);
949 		cmd = pci_conf_read(pd->pc, pd->tag, PCI_COMMAND_STATUS_REG);
950 		cmd |= PCI_COMMAND_IO_ENABLE | PCI_COMMAND_MEM_ENABLE;
951 		pci_conf_write(pd->pc, pd->tag, PCI_COMMAND_STATUS_REG, cmd);
952 	}
953 
954 	return rv;
955 }
956 
957 /*
958  * Calculate latency values, allocate I/O and MEM segments, then set them
959  * up.  If a PCI-PCI bridge is found, configure the bridge separately,
960  * which will cause a recursive call back here.
961  */
962 static int
963 configure_bus(pciconf_bus_t *pb)
964 {
965 	pciconf_dev_t	*pd;
966 	int		def_ltim, max_ltim, band, bus_mhz;
967 
968 	if (pb->ndevs == 0) {
969 		if (pci_conf_debug)
970 			printf("PCI bus %d - no devices\n", pb->busno);
971 		return (1);
972 	}
973 	bus_mhz = pb->freq_66 ? 66 : 33;
974 	max_ltim = pb->max_mingnt * bus_mhz / 4;	/* cvt to cycle count */
975 	band = 4000000;					/* 0.25us cycles/sec */
976 	if (band < pb->bandwidth_used) {
977 		printf("PCI bus %d: Warning: Total bandwidth exceeded!? (%d)\n",
978 		    pb->busno, pb->bandwidth_used);
979 		def_ltim = -1;
980 	} else {
981 		def_ltim = (band - pb->bandwidth_used) / pb->ndevs;
982 		if (def_ltim > pb->min_maxlat)
983 			def_ltim = pb->min_maxlat;
984 		def_ltim = def_ltim * bus_mhz / 4;
985 	}
986 	def_ltim = (def_ltim + 7) & ~7;
987 	max_ltim = (max_ltim + 7) & ~7;
988 
989 	pb->def_ltim = MIN( def_ltim, 255 );
990 	pb->max_ltim = MIN( MAX(max_ltim, def_ltim ), 255 );
991 
992 	/*
993 	 * Now we have what we need to initialize the devices.
994 	 * It would probably be better if we could allocate all of these
995 	 * for all busses at once, but "not right now".  First, get a list
996 	 * of free memory ranges from the m.d. system.
997 	 */
998 	if (setup_iowins(pb) || setup_memwins(pb)) {
999 		printf("PCI bus configuration failed: ");
1000 		printf("unable to assign all I/O and memory ranges.");
1001 		return -1;
1002 	}
1003 
1004 	/*
1005 	 * Configure the latency for the devices, and enable them.
1006 	 */
1007 	for (pd=pb->device ; pd < &pb->device[pb->ndevs] ; pd++) {
1008 		pcireg_t cmd, class, misc;
1009 		int	ltim;
1010 
1011 		if (pci_conf_debug) {
1012 			print_tag(pd->pc, pd->tag);
1013 			printf("Configuring device.\n");
1014 		}
1015 		class = pci_conf_read(pd->pc, pd->tag, PCI_CLASS_REG);
1016 		misc = pci_conf_read(pd->pc, pd->tag, PCI_BHLC_REG);
1017 		cmd = pci_conf_read(pd->pc, pd->tag, PCI_COMMAND_STATUS_REG);
1018 		if (pd->enable & PCI_CONF_ENABLE_PARITY)
1019 			cmd |= PCI_COMMAND_PARITY_ENABLE;
1020 		if (pd->enable & PCI_CONF_ENABLE_SERR)
1021 			cmd |= PCI_COMMAND_SERR_ENABLE;
1022 		if (pb->fast_b2b)
1023 			cmd |= PCI_COMMAND_BACKTOBACK_ENABLE;
1024 		if (PCI_CLASS(class) != PCI_CLASS_BRIDGE ||
1025 		    PCI_SUBCLASS(class) != PCI_SUBCLASS_BRIDGE_PCI) {
1026 			if (pd->enable & PCI_CONF_ENABLE_IO)
1027 				cmd |= PCI_COMMAND_IO_ENABLE;
1028 			if (pd->enable & PCI_CONF_ENABLE_MEM)
1029 				cmd |= PCI_COMMAND_MEM_ENABLE;
1030 			if (pd->enable & PCI_CONF_ENABLE_BM)
1031 				cmd |= PCI_COMMAND_MASTER_ENABLE;
1032 			ltim = pd->min_gnt * bus_mhz / 4;
1033 			ltim = MIN (MAX (pb->def_ltim, ltim), pb->max_ltim);
1034 		} else {
1035 			cmd |= PCI_COMMAND_MASTER_ENABLE;
1036 			ltim = MIN (pb->def_ltim, pb->max_ltim);
1037 		}
1038 		if ((pd->enable &
1039 		    (PCI_CONF_ENABLE_MEM|PCI_CONF_ENABLE_IO)) == 0) {
1040 			print_tag(pd->pc, pd->tag);
1041 			printf("Disabled due to lack of resources.\n");
1042 			cmd &= ~(PCI_COMMAND_MASTER_ENABLE |
1043 			    PCI_COMMAND_IO_ENABLE | PCI_COMMAND_MEM_ENABLE);
1044 		}
1045 		pci_conf_write(pd->pc, pd->tag, PCI_COMMAND_STATUS_REG, cmd);
1046 
1047 		misc &= ~((PCI_LATTIMER_MASK << PCI_LATTIMER_SHIFT) |
1048 		    (PCI_CACHELINE_MASK << PCI_CACHELINE_SHIFT));
1049 		misc |= (ltim & PCI_LATTIMER_MASK) << PCI_LATTIMER_SHIFT;
1050 		misc |= ((pb->cacheline_size >> 2) & PCI_CACHELINE_MASK) <<
1051 		    PCI_CACHELINE_SHIFT;
1052 		pci_conf_write(pd->pc, pd->tag, PCI_BHLC_REG, misc);
1053 
1054 		if (pd->ppb) {
1055 			if (configure_bridge(pd) < 0)
1056 				return -1;
1057 			continue;
1058 		}
1059 	}
1060 
1061 	if (pci_conf_debug) {
1062 		printf("PCI bus %d configured\n", pb->busno);
1063 	}
1064 
1065 	return 0;
1066 }
1067 
1068 /*
1069  * Let's configure the PCI bus.
1070  * This consists of basically scanning for all existing devices,
1071  * identifying their needs, and then making another pass over them
1072  * to set:
1073  *	1. I/O addresses
1074  *	2. Memory addresses (Prefetchable and not)
1075  *	3. PCI command register
1076  *	4. The latency part of the PCI BHLC (BIST (Built-In Self Test),
1077  *	    Header type, Latency timer, Cache line size) register
1078  *
1079  * The command register is set to enable fast back-to-back transactions
1080  * if the host bridge says it can handle it.  We also configure
1081  * Master Enable, SERR enable, parity enable, and (if this is not a
1082  * PCI-PCI bridge) the I/O and Memory spaces.  Apparently some devices
1083  * will not report some I/O space.
1084  *
1085  * The latency is computed to be a "fair share" of the bus bandwidth.
1086  * The bus bandwidth variable is initialized to the number of PCI cycles
1087  * in one second.  The number of cycles taken for one transaction by each
1088  * device (MAX_LAT + MIN_GNT) is then subtracted from the bandwidth.
1089  * Care is taken to ensure that the latency timer won't be set such that
1090  * it would exceed the critical time for any device.
1091  *
1092  * This is complicated somewhat due to the presence of bridges.  PCI-PCI
1093  * bridges are probed and configured recursively.
1094  */
1095 int
1096 pci_configure_bus(pci_chipset_tag_t pc, struct extent *ioext,
1097     struct extent *memext, struct extent *pmemext, int firstbus,
1098     int cacheline_size)
1099 {
1100 	pciconf_bus_t	*pb;
1101 	int		rv;
1102 
1103 	pb = malloc (sizeof (pciconf_bus_t), M_DEVBUF, M_NOWAIT);
1104 	pb->busno = firstbus;
1105 	pb->next_busno = pb->busno + 1;
1106 	pb->last_busno = 255;
1107 	pb->cacheline_size = cacheline_size;
1108 	pb->parent_bus = NULL;
1109 	pb->swiz = 0;
1110 	pb->io_32bit = 1;
1111 	pb->pmem_64bit = 0;
1112 	pb->ioext = ioext;
1113 	pb->memext = memext;
1114 	if (pmemext == NULL) {
1115 		pb->pmemext = memext;
1116 	} else {
1117 		pb->pmemext = pmemext;
1118 	}
1119 	pb->pc = pc;
1120 	pb->io_total = pb->mem_total = pb->pmem_total = 0;
1121 
1122 	rv = probe_bus(pb);
1123 	pb->last_busno = pb->next_busno-1;
1124 	if (rv == 0) {
1125 		rv = configure_bus(pb);
1126 	}
1127 
1128 	/*
1129 	 * All done!
1130 	 */
1131 	free(pb, M_DEVBUF);
1132 	return rv;
1133 }
1134