pci_cfgreg.c revision 111068
1/*
2 * Copyright (c) 1997, Stefan Esser <se@freebsd.org>
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 unmodified, this list of conditions, and the following
12 *    disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * $FreeBSD: head/sys/amd64/pci/pci_cfgreg.c 111068 2003-02-18 03:36:49Z peter $
29 *
30 */
31
32#include <sys/param.h>		/* XXX trim includes */
33#include <sys/systm.h>
34#include <sys/bus.h>
35#include <sys/kernel.h>
36#include <sys/module.h>
37#include <sys/malloc.h>
38#include <sys/lock.h>
39#include <sys/mutex.h>
40#include <vm/vm.h>
41#include <vm/pmap.h>
42#include <machine/md_var.h>
43#include <dev/pci/pcivar.h>
44#include <dev/pci/pcireg.h>
45#include <isa/isavar.h>
46#include <machine/pci_cfgreg.h>
47#include <machine/segments.h>
48#include <machine/pc/bios.h>
49
50#ifdef APIC_IO
51#include <machine/smp.h>
52#endif /* APIC_IO */
53
54#include "pcib_if.h"
55
56#define PRVERB(a) do {							\
57	if (bootverbose)						\
58		printf a ;						\
59} while(0)
60
61static int cfgmech;
62static int devmax;
63
64static int	pci_cfgintr_valid(struct PIR_entry *pe, int pin, int irq);
65static int	pci_cfgintr_unique(struct PIR_entry *pe, int pin);
66static int	pci_cfgintr_linked(struct PIR_entry *pe, int pin);
67static int	pci_cfgintr_search(struct PIR_entry *pe, int bus, int device, int matchpin, int pin);
68static int	pci_cfgintr_virgin(struct PIR_entry *pe, int pin);
69
70static void	pci_print_irqmask(u_int16_t irqs);
71static void	pci_print_route_table(struct PIR_table *prt, int size);
72static int	pcireg_cfgread(int bus, int slot, int func, int reg, int bytes);
73static void	pcireg_cfgwrite(int bus, int slot, int func, int reg, int data, int bytes);
74static int	pcireg_cfgopen(void);
75
76static struct PIR_table *pci_route_table;
77static int pci_route_count;
78
79static struct mtx pcicfg_mtx;
80
81/*
82 * Some BIOS writers seem to want to ignore the spec and put
83 * 0 in the intline rather than 255 to indicate none.  Some use
84 * numbers in the range 128-254 to indicate something strange and
85 * apparently undocumented anywhere.  Assume these are completely bogus
86 * and map them to 255, which means "none".
87 */
88static __inline__ int
89pci_i386_map_intline(int line)
90{
91	if (line == 0 || line >= 128)
92		return (PCI_INVALID_IRQ);
93	return (line);
94}
95
96static u_int16_t
97pcibios_get_version(void)
98{
99	struct bios_regs args;
100
101	if (PCIbios.ventry == 0) {
102		PRVERB(("pcibios: No call entry point\n"));
103		return (0);
104	}
105	args.eax = PCIBIOS_BIOS_PRESENT;
106	if (bios32(&args, PCIbios.ventry, GSEL(GCODE_SEL, SEL_KPL))) {
107		PRVERB(("pcibios: BIOS_PRESENT call failed\n"));
108		return (0);
109	}
110	if (args.edx != 0x20494350) {
111		PRVERB(("pcibios: BIOS_PRESENT didn't return 'PCI ' in edx\n"));
112		return (0);
113	}
114	return (args.ebx & 0xffff);
115}
116
117/*
118 * Initialise access to PCI configuration space
119 */
120int
121pci_cfgregopen(void)
122{
123	static int		opened = 0;
124	u_long			sigaddr;
125	static struct PIR_table	*pt;
126	u_int16_t		v;
127	u_int8_t		ck, *cv;
128	int			i;
129
130	if (opened)
131		return(1);
132
133	if (pcireg_cfgopen() == 0)
134		return(0);
135
136	v = pcibios_get_version();
137	if (v > 0)
138		printf("pcibios: BIOS version %x.%02x\n", (v & 0xff00) >> 8,
139		    v & 0xff);
140
141	/*
142	 * Look for the interrupt routing table.
143	 *
144	 * We use PCI BIOS's PIR table if it's available $PIR is the
145	 * standard way to do this.  Sadly, some machines are not
146	 * standards conforming and have _PIR instead.  We shrug and cope
147	 * by looking for both.
148	 */
149	if (pcibios_get_version() >= 0x0210 && pt == NULL) {
150		sigaddr = bios_sigsearch(0, "$PIR", 4, 16, 0);
151		if (sigaddr == 0)
152			sigaddr = bios_sigsearch(0, "_PIR", 4, 16, 0);
153		if (sigaddr != 0) {
154			pt = (struct PIR_table *)(uintptr_t)
155			    BIOS_PADDRTOVADDR(sigaddr);
156			for (cv = (u_int8_t *)pt, ck = 0, i = 0;
157			     i < (pt->pt_header.ph_length); i++) {
158				ck += cv[i];
159			}
160			if (ck == 0 && pt->pt_header.ph_length >
161			    sizeof(struct PIR_header)) {
162				pci_route_table = pt;
163				pci_route_count = (pt->pt_header.ph_length -
164				    sizeof(struct PIR_header)) /
165				    sizeof(struct PIR_entry);
166				printf("Using $PIR table, %d entries at %p\n",
167				    pci_route_count, pci_route_table);
168				if (bootverbose)
169					pci_print_route_table(pci_route_table,
170					    pci_route_count);
171			}
172		}
173	}
174	mtx_init(&pcicfg_mtx, "pcicfg", NULL, MTX_SPIN);
175	opened = 1;
176	return(1);
177}
178
179/*
180 * Read configuration space register
181 */
182u_int32_t
183pci_cfgregread(int bus, int slot, int func, int reg, int bytes)
184{
185	uint32_t line;
186#ifdef APIC_IO
187	uint32_t pin;
188
189	/*
190	 * If we are using the APIC, the contents of the intline
191	 * register will probably be wrong (since they are set up for
192	 * use with the PIC.  Rather than rewrite these registers
193	 * (maybe that would be smarter) we trap attempts to read them
194	 * and translate to our private vector numbers.
195	 */
196	if ((reg == PCIR_INTLINE) && (bytes == 1)) {
197
198		pin = pcireg_cfgread(bus, slot, func, PCIR_INTPIN, 1);
199		line = pcireg_cfgread(bus, slot, func, PCIR_INTLINE, 1);
200
201		if (pin != 0) {
202			int airq;
203
204			airq = pci_apic_irq(bus, slot, pin);
205			if (airq >= 0) {
206				/* PCI specific entry found in MP table */
207				if (airq != line)
208					undirect_pci_irq(line);
209				return(airq);
210			} else {
211				/*
212				 * PCI interrupts might be redirected
213				 * to the ISA bus according to some MP
214				 * tables. Use the same methods as
215				 * used by the ISA devices devices to
216				 * find the proper IOAPIC int pin.
217				 */
218				airq = isa_apic_irq(line);
219				if ((airq >= 0) && (airq != line)) {
220					/* XXX: undirect_pci_irq() ? */
221					undirect_isa_irq(line);
222					return(airq);
223				}
224			}
225		}
226		return(line);
227	}
228#else
229	/*
230	 * Some BIOS writers seem to want to ignore the spec and put
231	 * 0 in the intline rather than 255 to indicate none.  The rest of
232	 * the code uses 255 as an invalid IRQ.
233	 */
234	if (reg == PCIR_INTLINE && bytes == 1) {
235		line = pcireg_cfgread(bus, slot, func, PCIR_INTLINE, 1);
236		return pci_i386_map_intline(line);
237	}
238#endif /* APIC_IO */
239	return(pcireg_cfgread(bus, slot, func, reg, bytes));
240}
241
242/*
243 * Write configuration space register
244 */
245void
246pci_cfgregwrite(int bus, int slot, int func, int reg, u_int32_t data, int bytes)
247{
248
249	pcireg_cfgwrite(bus, slot, func, reg, data, bytes);
250}
251
252/*
253 * Route a PCI interrupt
254 */
255int
256pci_cfgintr(int bus, int device, int pin, int oldirq)
257{
258	struct PIR_entry	*pe;
259	int			i, irq;
260	struct bios_regs	args;
261	u_int16_t		v;
262 	int already = 0;
263 	int errok = 0;
264
265	v = pcibios_get_version();
266	if (v < 0x0210) {
267		PRVERB((
268		"pci_cfgintr: BIOS %x.%02x doesn't support interrupt routing\n",
269		    (v & 0xff00) >> 8, v & 0xff));
270		return (PCI_INVALID_IRQ);
271	}
272	if ((bus < 0) || (bus > 255) || (device < 0) || (device > 255) ||
273	    (pin < 1) || (pin > 4))
274		return(PCI_INVALID_IRQ);
275
276	/*
277	 * Scan the entry table for a contender
278	 */
279	for (i = 0, pe = &pci_route_table->pt_entry[0]; i < pci_route_count;
280	     i++, pe++) {
281		if ((bus != pe->pe_bus) || (device != pe->pe_device))
282			continue;
283		/*
284		 * A link of 0 means that this intpin is not connected to
285		 * any other device's interrupt pins and is not connected to
286		 * any of the Interrupt Router's interrupt pins, so we can't
287		 * route it.
288		 */
289		if (pe->pe_intpin[pin - 1].link == 0)
290			continue;
291
292		if (pci_cfgintr_valid(pe, pin, oldirq)) {
293			printf("pci_cfgintr: %d:%d INT%c BIOS irq %d\n", bus,
294			    device, 'A' + pin - 1, oldirq);
295			return (oldirq);
296		}
297
298		/*
299		 * We try to find a linked interrupt, then we look to see
300		 * if the interrupt is uniquely routed, then we look for
301		 * a virgin interrupt.  The virgin interrupt should return
302		 * an interrupt we can route, but if that fails, maybe we
303		 * should try harder to route a different interrupt.
304		 * However, experience has shown that that's rarely the
305		 * failure mode we see.
306		 */
307		irq = pci_cfgintr_linked(pe, pin);
308		if (irq != PCI_INVALID_IRQ)
309			already = 1;
310		if (irq == PCI_INVALID_IRQ) {
311			irq = pci_cfgintr_unique(pe, pin);
312			if (irq != PCI_INVALID_IRQ)
313				errok = 1;
314		}
315		if (irq == PCI_INVALID_IRQ)
316			irq = pci_cfgintr_virgin(pe, pin);
317		if (irq == PCI_INVALID_IRQ)
318			break;
319
320		/*
321		 * Ask the BIOS to route the interrupt.  If we picked an
322		 * interrupt that failed, we should really try other
323		 * choices that the BIOS offers us.
324		 *
325		 * For uniquely routed interrupts, we need to try
326		 * to route them on some machines.  Yet other machines
327		 * fail to route, so we have to pretend that in that
328		 * case it worked.  Isn't pc hardware fun?
329		 *
330		 * NOTE: if we want to whack hardware to do this, then
331		 * I think the right way to do that would be to have
332		 * bridge drivers that do this.  I'm not sure that the
333		 * $PIR table would be valid for those interrupt
334		 * routers.
335		 */
336		args.eax = PCIBIOS_ROUTE_INTERRUPT;
337		args.ebx = (bus << 8) | (device << 3);
338		/* pin value is 0xa - 0xd */
339		args.ecx = (irq << 8) | (0xa + pin - 1);
340		if (!already &&
341		    bios32(&args, PCIbios.ventry, GSEL(GCODE_SEL, SEL_KPL)) &&
342		    !errok) {
343			PRVERB(("pci_cfgintr: ROUTE_INTERRUPT failed.\n"));
344			return(PCI_INVALID_IRQ);
345		}
346		printf("pci_cfgintr: %d:%d INT%c routed to irq %d\n", bus,
347		    device, 'A' + pin - 1, irq);
348		return(irq);
349	}
350
351	PRVERB(("pci_cfgintr: can't route an interrupt to %d:%d INT%c\n", bus,
352	    device, 'A' + pin - 1));
353	return(PCI_INVALID_IRQ);
354}
355
356/*
357 * Check to see if an existing IRQ setting is valid.
358 */
359static int
360pci_cfgintr_valid(struct PIR_entry *pe, int pin, int irq)
361{
362	uint32_t irqmask;
363
364	if (!PCI_INTERRUPT_VALID(irq))
365		return (0);
366	irqmask = pe->pe_intpin[pin - 1].irqs;
367	if (irqmask & (1 << irq)) {
368		PRVERB(("pci_cfgintr_valid: BIOS irq %d is valid\n", irq));
369		return (1);
370	}
371	return (0);
372}
373
374/*
375 * Look to see if the routing table claims this pin is uniquely routed.
376 */
377static int
378pci_cfgintr_unique(struct PIR_entry *pe, int pin)
379{
380	int		irq;
381	uint32_t	irqmask;
382
383	irqmask = pe->pe_intpin[pin - 1].irqs;
384	if (irqmask != 0 && powerof2(irqmask)) {
385		irq = ffs(irqmask) - 1;
386		PRVERB(("pci_cfgintr_unique: hard-routed to irq %d\n", irq));
387		return(irq);
388	}
389	return(PCI_INVALID_IRQ);
390}
391
392/*
393 * Look for another device which shares the same link byte and
394 * already has a unique IRQ, or which has had one routed already.
395 */
396static int
397pci_cfgintr_linked(struct PIR_entry *pe, int pin)
398{
399	struct PIR_entry	*oe;
400	struct PIR_intpin	*pi;
401	int			i, j, irq;
402
403	/*
404	 * Scan table slots.
405	 */
406	for (i = 0, oe = &pci_route_table->pt_entry[0]; i < pci_route_count;
407	     i++, oe++) {
408		/* scan interrupt pins */
409		for (j = 0, pi = &oe->pe_intpin[0]; j < 4; j++, pi++) {
410
411			/* don't look at the entry we're trying to match */
412			if ((pe == oe) && (i == (pin - 1)))
413				continue;
414			/* compare link bytes */
415			if (pi->link != pe->pe_intpin[pin - 1].link)
416				continue;
417			/* link destination mapped to a unique interrupt? */
418			if (pi->irqs != 0 && powerof2(pi->irqs)) {
419				irq = ffs(pi->irqs) - 1;
420				PRVERB(("pci_cfgintr_linked: linked (%x) to hard-routed irq %d\n",
421				    pi->link, irq));
422				return(irq);
423			}
424
425			/*
426			 * look for the real PCI device that matches this
427			 * table entry
428			 */
429			irq = pci_cfgintr_search(pe, oe->pe_bus, oe->pe_device,
430			    j, pin);
431			if (irq != PCI_INVALID_IRQ)
432				return(irq);
433		}
434	}
435	return(PCI_INVALID_IRQ);
436}
437
438/*
439 * Scan for the real PCI device at (bus)/(device) using intpin (matchpin) and
440 * see if it has already been assigned an interrupt.
441 */
442static int
443pci_cfgintr_search(struct PIR_entry *pe, int bus, int device, int matchpin, int pin)
444{
445	devclass_t		pci_devclass;
446	device_t		*pci_devices;
447	int			pci_count;
448	device_t		*pci_children;
449	int			pci_childcount;
450	device_t		*busp, *childp;
451	int			i, j, irq;
452
453	/*
454	 * Find all the PCI busses.
455	 */
456	pci_count = 0;
457	if ((pci_devclass = devclass_find("pci")) != NULL)
458		devclass_get_devices(pci_devclass, &pci_devices, &pci_count);
459
460	/*
461	 * Scan all the PCI busses/devices looking for this one.
462	 */
463	irq = PCI_INVALID_IRQ;
464	for (i = 0, busp = pci_devices; (i < pci_count) && (irq == PCI_INVALID_IRQ);
465	     i++, busp++) {
466		pci_childcount = 0;
467		device_get_children(*busp, &pci_children, &pci_childcount);
468
469		for (j = 0, childp = pci_children; j < pci_childcount; j++,
470		    childp++) {
471			if ((pci_get_bus(*childp) == bus) &&
472			    (pci_get_slot(*childp) == device) &&
473			    (pci_get_intpin(*childp) == matchpin)) {
474				irq = pci_i386_map_intline(pci_get_irq(*childp));
475				if (irq != PCI_INVALID_IRQ)
476					PRVERB(("pci_cfgintr_search: linked (%x) to configured irq %d at %d:%d:%d\n",
477					    pe->pe_intpin[pin - 1].link, irq,
478					    pci_get_bus(*childp),
479					    pci_get_slot(*childp),
480					    pci_get_function(*childp)));
481				break;
482			}
483		}
484		if (pci_children != NULL)
485			free(pci_children, M_TEMP);
486	}
487	if (pci_devices != NULL)
488		free(pci_devices, M_TEMP);
489	return(irq);
490}
491
492/*
493 * Pick a suitable IRQ from those listed as routable to this device.
494 */
495static int
496pci_cfgintr_virgin(struct PIR_entry *pe, int pin)
497{
498	int		irq, ibit;
499
500	/*
501	 * first scan the set of PCI-only interrupts and see if any of these
502	 * are routable
503	 */
504	for (irq = 0; irq < 16; irq++) {
505		ibit = (1 << irq);
506
507		/* can we use this interrupt? */
508		if ((pci_route_table->pt_header.ph_pci_irqs & ibit) &&
509		    (pe->pe_intpin[pin - 1].irqs & ibit)) {
510			PRVERB(("pci_cfgintr_virgin: using routable PCI-only interrupt %d\n", irq));
511			return(irq);
512		}
513	}
514
515	/* life is tough, so just pick an interrupt */
516	for (irq = 0; irq < 16; irq++) {
517		ibit = (1 << irq);
518		if (pe->pe_intpin[pin - 1].irqs & ibit) {
519			PRVERB(("pci_cfgintr_virgin: using routable interrupt %d\n", irq));
520			return(irq);
521		}
522	}
523	return(PCI_INVALID_IRQ);
524}
525
526static void
527pci_print_irqmask(u_int16_t irqs)
528{
529	int i, first;
530
531	if (irqs == 0) {
532		printf("none");
533		return;
534	}
535	first = 1;
536	for (i = 0; i < 16; i++, irqs >>= 1)
537		if (irqs & 1) {
538			if (!first)
539				printf(" ");
540			else
541				first = 0;
542			printf("%d", i);
543		}
544}
545
546/*
547 * Dump the contents of a PCI BIOS Interrupt Routing Table to the console.
548 */
549static void
550pci_print_route_table(struct PIR_table *prt, int size)
551{
552	struct PIR_entry *entry;
553	struct PIR_intpin *intpin;
554	int i, pin;
555
556	printf("PCI-Only Interrupts: ");
557	pci_print_irqmask(prt->pt_header.ph_pci_irqs);
558	printf("\nLocation  Bus Device Pin  Link  IRQs\n");
559	entry = &prt->pt_entry[0];
560	for (i = 0; i < size; i++, entry++) {
561		intpin = &entry->pe_intpin[0];
562		for (pin = 0; pin < 4; pin++, intpin++)
563			if (intpin->link != 0) {
564				if (entry->pe_slot == 0)
565					printf("embedded ");
566				else
567					printf("slot %-3d ", entry->pe_slot);
568				printf(" %3d  %3d    %c   0x%02x  ",
569				    entry->pe_bus, entry->pe_device,
570				    'A' + pin, intpin->link);
571				pci_print_irqmask(intpin->irqs);
572				printf("\n");
573			}
574	}
575}
576
577/*
578 * See if any interrupts for a given PCI bus are routed in the PIR.  Don't
579 * even bother looking if the BIOS doesn't support routing anyways.
580 */
581int
582pci_probe_route_table(int bus)
583{
584	int i;
585	u_int16_t v;
586
587	v = pcibios_get_version();
588	if (v < 0x0210)
589		return (0);
590	for (i = 0; i < pci_route_count; i++)
591		if (pci_route_table->pt_entry[i].pe_bus == bus)
592			return (1);
593	return (0);
594}
595
596/*
597 * Configuration space access using direct register operations
598 */
599
600/* enable configuration space accesses and return data port address */
601static int
602pci_cfgenable(unsigned bus, unsigned slot, unsigned func, int reg, int bytes)
603{
604	int dataport = 0;
605
606	if (bus <= PCI_BUSMAX
607	    && slot < devmax
608	    && func <= PCI_FUNCMAX
609	    && reg <= PCI_REGMAX
610	    && bytes != 3
611	    && (unsigned) bytes <= 4
612	    && (reg & (bytes - 1)) == 0) {
613		switch (cfgmech) {
614		case 1:
615			outl(CONF1_ADDR_PORT, (1 << 31)
616			    | (bus << 16) | (slot << 11)
617			    | (func << 8) | (reg & ~0x03));
618			dataport = CONF1_DATA_PORT + (reg & 0x03);
619			break;
620		case 2:
621			outb(CONF2_ENABLE_PORT, 0xf0 | (func << 1));
622			outb(CONF2_FORWARD_PORT, bus);
623			dataport = 0xc000 | (slot << 8) | reg;
624			break;
625		}
626	}
627	return (dataport);
628}
629
630/* disable configuration space accesses */
631static void
632pci_cfgdisable(void)
633{
634	switch (cfgmech) {
635	case 1:
636		outl(CONF1_ADDR_PORT, 0);
637		break;
638	case 2:
639		outb(CONF2_ENABLE_PORT, 0);
640		outb(CONF2_FORWARD_PORT, 0);
641		break;
642	}
643}
644
645static int
646pcireg_cfgread(int bus, int slot, int func, int reg, int bytes)
647{
648	int data = -1;
649	int port;
650
651	mtx_lock_spin(&pcicfg_mtx);
652	port = pci_cfgenable(bus, slot, func, reg, bytes);
653	if (port != 0) {
654		switch (bytes) {
655		case 1:
656			data = inb(port);
657			break;
658		case 2:
659			data = inw(port);
660			break;
661		case 4:
662			data = inl(port);
663			break;
664		}
665		pci_cfgdisable();
666	}
667	mtx_unlock_spin(&pcicfg_mtx);
668	return (data);
669}
670
671static void
672pcireg_cfgwrite(int bus, int slot, int func, int reg, int data, int bytes)
673{
674	int port;
675
676	mtx_lock_spin(&pcicfg_mtx);
677	port = pci_cfgenable(bus, slot, func, reg, bytes);
678	if (port != 0) {
679		switch (bytes) {
680		case 1:
681			outb(port, data);
682			break;
683		case 2:
684			outw(port, data);
685			break;
686		case 4:
687			outl(port, data);
688			break;
689		}
690		pci_cfgdisable();
691	}
692	mtx_unlock_spin(&pcicfg_mtx);
693}
694
695/* check whether the configuration mechanism has been correctly identified */
696static int
697pci_cfgcheck(int maxdev)
698{
699	uint32_t id, class;
700	uint8_t header;
701	uint8_t device;
702	int port;
703
704	if (bootverbose)
705		printf("pci_cfgcheck:\tdevice ");
706
707	for (device = 0; device < maxdev; device++) {
708		if (bootverbose)
709			printf("%d ", device);
710
711		port = pci_cfgenable(0, device, 0, 0, 4);
712		id = inl(port);
713		if (id == 0 || id == 0xffffffff)
714			continue;
715
716		port = pci_cfgenable(0, device, 0, 8, 4);
717		class = inl(port) >> 8;
718		if (bootverbose)
719			printf("[class=%06x] ", class);
720		if (class == 0 || (class & 0xf870ff) != 0)
721			continue;
722
723		port = pci_cfgenable(0, device, 0, 14, 1);
724		header = inb(port);
725		if (bootverbose)
726			printf("[hdr=%02x] ", header);
727		if ((header & 0x7e) != 0)
728			continue;
729
730		if (bootverbose)
731			printf("is there (id=%08x)\n", id);
732
733		pci_cfgdisable();
734		return (1);
735	}
736	if (bootverbose)
737		printf("-- nothing found\n");
738
739	pci_cfgdisable();
740	return (0);
741}
742
743static int
744pcireg_cfgopen(void)
745{
746	uint32_t mode1res, oldval1;
747	uint8_t mode2res, oldval2;
748
749	oldval1 = inl(CONF1_ADDR_PORT);
750
751	if (bootverbose) {
752		printf("pci_open(1):\tmode 1 addr port (0x0cf8) is 0x%08x\n",
753		    oldval1);
754	}
755
756	if ((oldval1 & CONF1_ENABLE_MSK) == 0) {
757
758		cfgmech = 1;
759		devmax = 32;
760
761		outl(CONF1_ADDR_PORT, CONF1_ENABLE_CHK);
762		outb(CONF1_ADDR_PORT + 3, 0);
763		mode1res = inl(CONF1_ADDR_PORT);
764		outl(CONF1_ADDR_PORT, oldval1);
765
766		if (bootverbose)
767			printf("pci_open(1a):\tmode1res=0x%08x (0x%08lx)\n",
768			    mode1res, CONF1_ENABLE_CHK);
769
770		if (mode1res) {
771			if (pci_cfgcheck(32))
772				return (cfgmech);
773		}
774
775		outl(CONF1_ADDR_PORT, CONF1_ENABLE_CHK1);
776		mode1res = inl(CONF1_ADDR_PORT);
777		outl(CONF1_ADDR_PORT, oldval1);
778
779		if (bootverbose)
780			printf("pci_open(1b):\tmode1res=0x%08x (0x%08lx)\n",
781			    mode1res, CONF1_ENABLE_CHK1);
782
783		if ((mode1res & CONF1_ENABLE_MSK1) == CONF1_ENABLE_RES1) {
784			if (pci_cfgcheck(32))
785				return (cfgmech);
786		}
787	}
788
789	oldval2 = inb(CONF2_ENABLE_PORT);
790
791	if (bootverbose) {
792		printf("pci_open(2):\tmode 2 enable port (0x0cf8) is 0x%02x\n",
793		    oldval2);
794	}
795
796	if ((oldval2 & 0xf0) == 0) {
797
798		cfgmech = 2;
799		devmax = 16;
800
801		outb(CONF2_ENABLE_PORT, CONF2_ENABLE_CHK);
802		mode2res = inb(CONF2_ENABLE_PORT);
803		outb(CONF2_ENABLE_PORT, oldval2);
804
805		if (bootverbose)
806			printf("pci_open(2a):\tmode2res=0x%02x (0x%02x)\n",
807			    mode2res, CONF2_ENABLE_CHK);
808
809		if (mode2res == CONF2_ENABLE_RES) {
810			if (bootverbose)
811				printf("pci_open(2a):\tnow trying mechanism 2\n");
812
813			if (pci_cfgcheck(16))
814				return (cfgmech);
815		}
816	}
817
818	cfgmech = 0;
819	devmax = 0;
820	return (cfgmech);
821}
822
823