xref: /freebsd/sys/i386/pci/pci_cfgreg.c (revision a3e8fd0b7f663db7eafff527d5c3ca3bcfa8a537)
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  * $FreeBSD$
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 <vm/vm.h>
39 #include <vm/pmap.h>
40 #include <machine/md_var.h>
41 #include <dev/pci/pcivar.h>
42 #include <dev/pci/pcireg.h>
43 #include <isa/isavar.h>
44 #include <machine/pci_cfgreg.h>
45 #include <machine/segments.h>
46 #include <machine/pc/bios.h>
47 
48 #ifdef APIC_IO
49 #include <machine/smp.h>
50 #endif /* APIC_IO */
51 
52 #include "pcib_if.h"
53 
54 #define PRVERB(a) do {							\
55 	if (bootverbose)						\
56 		printf a ;						\
57 } while(0)
58 
59 static int cfgmech;
60 static int devmax;
61 static int usebios;
62 static int enable_pcibios = 0;
63 
64 TUNABLE_INT("hw.pci.enable_pcibios", &enable_pcibios);
65 
66 static int	pci_cfgintr_valid(struct PIR_entry *pe, int pin, int irq);
67 static int	pci_cfgintr_unique(struct PIR_entry *pe, int pin);
68 static int	pci_cfgintr_linked(struct PIR_entry *pe, int pin);
69 static int	pci_cfgintr_search(struct PIR_entry *pe, int bus, int device, int matchpin, int pin);
70 static int	pci_cfgintr_virgin(struct PIR_entry *pe, int pin);
71 
72 static void	pci_print_irqmask(u_int16_t irqs);
73 static void	pci_print_route_table(struct PIR_table *prt, int size);
74 #ifdef USE_PCI_BIOS_FOR_READ_WRITE
75 static int	pcibios_cfgread(int bus, int slot, int func, int reg, int bytes);
76 static void	pcibios_cfgwrite(int bus, int slot, int func, int reg, int data, int bytes);
77 #endif
78 static int	pcibios_cfgopen(void);
79 static int	pcireg_cfgread(int bus, int slot, int func, int reg, int bytes);
80 static void	pcireg_cfgwrite(int bus, int slot, int func, int reg, int data, int bytes);
81 static int	pcireg_cfgopen(void);
82 
83 static struct PIR_table *pci_route_table;
84 static int pci_route_count;
85 
86 /*
87  * Some BIOS writers seem to want to ignore the spec and put
88  * 0 in the intline rather than 255 to indicate none.  Some use
89  * numbers in the range 128-254 to indicate something strange and
90  * apparently undocumented anywhere.  Assume these are completely bogus
91  * and map them to 255, which means "none".
92  */
93 static __inline__ int
94 pci_i386_map_intline(int line)
95 {
96 	if (line == 0 || line >= 128)
97 		return (PCI_INVALID_IRQ);
98 	return (line);
99 }
100 
101 int
102 pci_pcibios_active(void)
103 {
104 	return (usebios);
105 }
106 
107 int
108 pci_kill_pcibios(void)
109 {
110 	usebios = 0;
111 	return (pcireg_cfgopen() != 0);
112 }
113 
114 static u_int16_t
115 pcibios_get_version(void)
116 {
117 	struct bios_regs args;
118 
119 	if (PCIbios.ventry == 0) {
120 		PRVERB(("pcibios: No call entry point\n"));
121 		return (0);
122 	}
123 	args.eax = PCIBIOS_BIOS_PRESENT;
124 	if (bios32(&args, PCIbios.ventry, GSEL(GCODE_SEL, SEL_KPL))) {
125 		PRVERB(("pcibios: BIOS_PRESENT call failed\n"));
126 		return (0);
127 	}
128 	if (args.edx != 0x20494350) {
129 		PRVERB(("pcibios: BIOS_PRESENT didn't return 'PCI ' in edx\n"));
130 		return (0);
131 	}
132 	return (args.ebx & 0xffff);
133 }
134 
135 /*
136  * Initialise access to PCI configuration space
137  */
138 int
139 pci_cfgregopen(void)
140 {
141 	static int		opened = 0;
142 	u_long			sigaddr;
143 	static struct PIR_table	*pt;
144 	u_int8_t		ck, *cv;
145 	int			i;
146 
147 	if (opened)
148 		return(1);
149 
150 	if (pcibios_cfgopen() != 0)
151 		usebios = 1;
152 	else if (pcireg_cfgopen() != 0)
153 		usebios = 0;
154 	else
155 		return(0);
156 
157 	/*
158 	 * Look for the interrupt routing table.
159 	 *
160 	 * We use PCI BIOS's PIR table if it's available $PIR is the
161 	 * standard way to do this.  Sadly, some machines are not
162 	 * standards conforming and have _PIR instead.  We shrug and cope
163 	 * by looking for both.
164 	 */
165 	if (pcibios_get_version() >= 0x0210 && pt == NULL) {
166 		sigaddr = bios_sigsearch(0, "$PIR", 4, 16, 0);
167 		if (sigaddr == 0)
168 			sigaddr = bios_sigsearch(0, "_PIR", 4, 16, 0);
169 		if (sigaddr != 0) {
170 			pt = (struct PIR_table *)(uintptr_t)
171 			    BIOS_PADDRTOVADDR(sigaddr);
172 			for (cv = (u_int8_t *)pt, ck = 0, i = 0;
173 			     i < (pt->pt_header.ph_length); i++) {
174 				ck += cv[i];
175 			}
176 			if (ck == 0 && pt->pt_header.ph_length >
177 			    sizeof(struct PIR_header)) {
178 				pci_route_table = pt;
179 				pci_route_count = (pt->pt_header.ph_length -
180 				    sizeof(struct PIR_header)) /
181 				    sizeof(struct PIR_entry);
182 				printf("Using $PIR table, %d entries at %p\n",
183 				    pci_route_count, pci_route_table);
184 				if (bootverbose)
185 					pci_print_route_table(pci_route_table,
186 					    pci_route_count);
187 			}
188 		}
189 	}
190 	opened = 1;
191 	return(1);
192 }
193 
194 /*
195  * Read configuration space register
196  */
197 static u_int32_t
198 pci_do_cfgregread(int bus, int slot, int func, int reg, int bytes)
199 {
200 #ifdef USE_PCI_BIOS_FOR_READ_WRITE
201 	return(usebios ?
202 	    pcibios_cfgread(bus, slot, func, reg, bytes) :
203 	    pcireg_cfgread(bus, slot, func, reg, bytes));
204 #else
205 	return (pcireg_cfgread(bus, slot, func, reg, bytes));
206 #endif
207 }
208 
209 u_int32_t
210 pci_cfgregread(int bus, int slot, int func, int reg, int bytes)
211 {
212 	uint32_t line;
213 #ifdef APIC_IO
214 	uint32_t pin;
215 
216 	/*
217 	 * If we are using the APIC, the contents of the intline
218 	 * register will probably be wrong (since they are set up for
219 	 * use with the PIC.  Rather than rewrite these registers
220 	 * (maybe that would be smarter) we trap attempts to read them
221 	 * and translate to our private vector numbers.
222 	 */
223 	if ((reg == PCIR_INTLINE) && (bytes == 1)) {
224 
225 		pin = pci_do_cfgregread(bus, slot, func, PCIR_INTPIN, 1);
226 		line = pci_do_cfgregread(bus, slot, func, PCIR_INTLINE, 1);
227 
228 		if (pin != 0) {
229 			int airq;
230 
231 			airq = pci_apic_irq(bus, slot, pin);
232 			if (airq >= 0) {
233 				/* PCI specific entry found in MP table */
234 				if (airq != line)
235 					undirect_pci_irq(line);
236 				return(airq);
237 			} else {
238 				/*
239 				 * PCI interrupts might be redirected
240 				 * to the ISA bus according to some MP
241 				 * tables. Use the same methods as
242 				 * used by the ISA devices devices to
243 				 * find the proper IOAPIC int pin.
244 				 */
245 				airq = isa_apic_irq(line);
246 				if ((airq >= 0) && (airq != line)) {
247 					/* XXX: undirect_pci_irq() ? */
248 					undirect_isa_irq(line);
249 					return(airq);
250 				}
251 			}
252 		}
253 		return(line);
254 	}
255 #else
256 	/*
257 	 * Some BIOS writers seem to want to ignore the spec and put
258 	 * 0 in the intline rather than 255 to indicate none.  The rest of
259 	 * the code uses 255 as an invalid IRQ.
260 	 */
261 	if (reg == PCIR_INTLINE && bytes == 1) {
262 		line = pci_do_cfgregread(bus, slot, func, PCIR_INTLINE, 1);
263 		return pci_i386_map_intline(line);
264 	}
265 #endif /* APIC_IO */
266 	return(pci_do_cfgregread(bus, slot, func, reg, bytes));
267 }
268 
269 /*
270  * Write configuration space register
271  */
272 void
273 pci_cfgregwrite(int bus, int slot, int func, int reg, u_int32_t data, int bytes)
274 {
275 #ifdef USE_PCI_BIOS_FOR_READ_WRITE
276 	if (usebios)
277 		pcibios_cfgwrite(bus, slot, func, reg, data, bytes);
278 	else
279 		pcireg_cfgwrite(bus, slot, func, reg, data, bytes);
280 #else
281 	pcireg_cfgwrite(bus, slot, func, reg, data, bytes);
282 #endif
283 }
284 
285 /*
286  * Route a PCI interrupt
287  */
288 int
289 pci_cfgintr(int bus, int device, int pin, int oldirq)
290 {
291 	struct PIR_entry	*pe;
292 	int			i, irq;
293 	struct bios_regs	args;
294 	u_int16_t		v;
295 	int already = 0;
296 
297 	v = pcibios_get_version();
298 	if (v < 0x0210) {
299 		PRVERB((
300 		"pci_cfgintr: BIOS %x.%02x doesn't support interrupt routing\n",
301 		    (v & 0xff00) >> 8, v & 0xff));
302 		return (PCI_INVALID_IRQ);
303 	}
304 	if ((bus < 0) || (bus > 255) || (device < 0) || (device > 255) ||
305 	    (pin < 1) || (pin > 4))
306 		return(PCI_INVALID_IRQ);
307 
308 	/*
309 	 * Scan the entry table for a contender
310 	 */
311 	for (i = 0, pe = &pci_route_table->pt_entry[0]; i < pci_route_count;
312 	     i++, pe++) {
313 		if ((bus != pe->pe_bus) || (device != pe->pe_device))
314 			continue;
315 		/*
316 		 * A link of 0 means that this intpin is not connected to
317 		 * any other device's interrupt pins and is not connected to
318 		 * any of the Interrupt Router's interrupt pins, so we can't
319 		 * route it.
320 		 */
321 		if (pe->pe_intpin[pin - 1].link == 0)
322 			continue;
323 
324 		if (pci_cfgintr_valid(pe, pin, oldirq)) {
325 			printf("pci_cfgintr: %d:%d INT%c BIOS irq %d\n", bus,
326 			    device, 'A' + pin - 1, oldirq);
327 			return (oldirq);
328 		}
329 		irq = pci_cfgintr_linked(pe, pin);
330 		if (irq == PCI_INVALID_IRQ)
331 			irq = pci_cfgintr_unique(pe, pin);
332 		if (irq == PCI_INVALID_IRQ)
333 			irq = pci_cfgintr_virgin(pe, pin);
334 		if (irq == PCI_INVALID_IRQ)
335 			break;
336 
337 		/*
338 		 * Ask the BIOS to route the interrupt
339 		 */
340 		args.eax = PCIBIOS_ROUTE_INTERRUPT;
341 		args.ebx = (bus << 8) | (device << 3);
342 		/* pin value is 0xa - 0xd */
343 		args.ecx = (irq << 8) | (0xa + pin - 1);
344 		if (!already &&
345 		    bios32(&args, PCIbios.ventry, GSEL(GCODE_SEL, SEL_KPL))) {
346 			/*
347 			 * XXX if it fails, we should try to smack the router
348 			 * hardware directly.
349 			 * XXX Also, there may be other choices that we can
350 			 * try that will work.
351 			 */
352 			PRVERB(("pci_cfgintr: ROUTE_INTERRUPT failed.\n"));
353 			return(PCI_INVALID_IRQ);
354 		}
355 		printf("pci_cfgintr: %d:%d INT%c routed to irq %d\n", bus,
356 		    device, 'A' + pin - 1, irq);
357 		return(irq);
358 	}
359 
360 	PRVERB(("pci_cfgintr: can't route an interrupt to %d:%d INT%c\n", bus,
361 	    device, 'A' + pin - 1));
362 	return(PCI_INVALID_IRQ);
363 }
364 
365 /*
366  * Check to see if an existing IRQ setting is valid.
367  */
368 static int
369 pci_cfgintr_valid(struct PIR_entry *pe, int pin, int irq)
370 {
371 	uint32_t irqmask;
372 
373 	if (!PCI_INTERRUPT_VALID(irq))
374 		return (0);
375 	irqmask = pe->pe_intpin[pin - 1].irqs;
376 	if (irqmask & (1 << irq)) {
377 		PRVERB(("pci_cfgintr_valid: BIOS irq %d is valid\n", irq));
378 		return (1);
379 	}
380 	return (0);
381 }
382 
383 /*
384  * Look to see if the routing table claims this pin is uniquely routed.
385  */
386 static int
387 pci_cfgintr_unique(struct PIR_entry *pe, int pin)
388 {
389 	int		irq;
390 	uint32_t	irqmask;
391 
392 	irqmask = pe->pe_intpin[pin - 1].irqs;
393 	if (irqmask != 0 && powerof2(irqmask)) {
394 		irq = ffs(irqmask) - 1;
395 		PRVERB(("pci_cfgintr_unique: hard-routed to irq %d\n", irq));
396 		return(irq);
397 	}
398 	return(PCI_INVALID_IRQ);
399 }
400 
401 /*
402  * Look for another device which shares the same link byte and
403  * already has a unique IRQ, or which has had one routed already.
404  */
405 static int
406 pci_cfgintr_linked(struct PIR_entry *pe, int pin)
407 {
408 	struct PIR_entry	*oe;
409 	struct PIR_intpin	*pi;
410 	int			i, j, irq;
411 
412 	/*
413 	 * Scan table slots.
414 	 */
415 	for (i = 0, oe = &pci_route_table->pt_entry[0]; i < pci_route_count;
416 	     i++, oe++) {
417 		/* scan interrupt pins */
418 		for (j = 0, pi = &oe->pe_intpin[0]; j < 4; j++, pi++) {
419 
420 			/* don't look at the entry we're trying to match */
421 			if ((pe == oe) && (i == (pin - 1)))
422 				continue;
423 			/* compare link bytes */
424 			if (pi->link != pe->pe_intpin[pin - 1].link)
425 				continue;
426 			/* link destination mapped to a unique interrupt? */
427 			if (pi->irqs != 0 && powerof2(pi->irqs)) {
428 				irq = ffs(pi->irqs) - 1;
429 				PRVERB(("pci_cfgintr_linked: linked (%x) to hard-routed irq %d\n",
430 				    pi->link, irq));
431 				return(irq);
432 			}
433 
434 			/*
435 			 * look for the real PCI device that matches this
436 			 * table entry
437 			 */
438 			irq = pci_cfgintr_search(pe, oe->pe_bus, oe->pe_device,
439 			    j, pin);
440 			if (irq != PCI_INVALID_IRQ)
441 				return(irq);
442 		}
443 	}
444 	return(PCI_INVALID_IRQ);
445 }
446 
447 /*
448  * Scan for the real PCI device at (bus)/(device) using intpin (matchpin) and
449  * see if it has already been assigned an interrupt.
450  */
451 static int
452 pci_cfgintr_search(struct PIR_entry *pe, int bus, int device, int matchpin, int pin)
453 {
454 	devclass_t		pci_devclass;
455 	device_t		*pci_devices;
456 	int			pci_count;
457 	device_t		*pci_children;
458 	int			pci_childcount;
459 	device_t		*busp, *childp;
460 	int			i, j, irq;
461 
462 	/*
463 	 * Find all the PCI busses.
464 	 */
465 	pci_count = 0;
466 	if ((pci_devclass = devclass_find("pci")) != NULL)
467 		devclass_get_devices(pci_devclass, &pci_devices, &pci_count);
468 
469 	/*
470 	 * Scan all the PCI busses/devices looking for this one.
471 	 */
472 	irq = PCI_INVALID_IRQ;
473 	for (i = 0, busp = pci_devices; (i < pci_count) && (irq == PCI_INVALID_IRQ);
474 	     i++, busp++) {
475 		pci_childcount = 0;
476 		device_get_children(*busp, &pci_children, &pci_childcount);
477 
478 		for (j = 0, childp = pci_children; j < pci_childcount; j++,
479 		    childp++) {
480 			if ((pci_get_bus(*childp) == bus) &&
481 			    (pci_get_slot(*childp) == device) &&
482 			    (pci_get_intpin(*childp) == matchpin)) {
483 				irq = pci_i386_map_intline(pci_get_irq(*childp));
484 				if (irq != PCI_INVALID_IRQ)
485 					PRVERB(("pci_cfgintr_search: linked (%x) to configured irq %d at %d:%d:%d\n",
486 					    pe->pe_intpin[pin - 1].link, irq,
487 					    pci_get_bus(*childp),
488 					    pci_get_slot(*childp),
489 					    pci_get_function(*childp)));
490 				break;
491 			}
492 		}
493 		if (pci_children != NULL)
494 			free(pci_children, M_TEMP);
495 	}
496 	if (pci_devices != NULL)
497 		free(pci_devices, M_TEMP);
498 	return(irq);
499 }
500 
501 /*
502  * Pick a suitable IRQ from those listed as routable to this device.
503  */
504 static int
505 pci_cfgintr_virgin(struct PIR_entry *pe, int pin)
506 {
507 	int		irq, ibit;
508 
509 	/*
510 	 * first scan the set of PCI-only interrupts and see if any of these
511 	 * are routable
512 	 */
513 	for (irq = 0; irq < 16; irq++) {
514 		ibit = (1 << irq);
515 
516 		/* can we use this interrupt? */
517 		if ((pci_route_table->pt_header.ph_pci_irqs & ibit) &&
518 		    (pe->pe_intpin[pin - 1].irqs & ibit)) {
519 			PRVERB(("pci_cfgintr_virgin: using routable PCI-only interrupt %d\n", irq));
520 			return(irq);
521 		}
522 	}
523 
524 	/* life is tough, so just pick an interrupt */
525 	for (irq = 0; irq < 16; irq++) {
526 		ibit = (1 << irq);
527 		if (pe->pe_intpin[pin - 1].irqs & ibit) {
528 			PRVERB(("pci_cfgintr_virgin: using routable interrupt %d\n", irq));
529 			return(irq);
530 		}
531 	}
532 	return(PCI_INVALID_IRQ);
533 }
534 
535 static void
536 pci_print_irqmask(u_int16_t irqs)
537 {
538 	int i, first;
539 
540 	if (irqs == 0) {
541 		printf("none");
542 		return;
543 	}
544 	first = 1;
545 	for (i = 0; i < 16; i++, irqs >>= 1)
546 		if (irqs & 1) {
547 			if (!first)
548 				printf(" ");
549 			else
550 				first = 0;
551 			printf("%d", i);
552 		}
553 }
554 
555 /*
556  * Dump the contents of a PCI BIOS Interrupt Routing Table to the console.
557  */
558 static void
559 pci_print_route_table(struct PIR_table *prt, int size)
560 {
561 	struct PIR_entry *entry;
562 	struct PIR_intpin *intpin;
563 	int i, pin;
564 
565 	printf("PCI-Only Interrupts: ");
566 	pci_print_irqmask(prt->pt_header.ph_pci_irqs);
567 	printf("\nLocation  Bus Device Pin  Link  IRQs\n");
568 	entry = &prt->pt_entry[0];
569 	for (i = 0; i < size; i++, entry++) {
570 		intpin = &entry->pe_intpin[0];
571 		for (pin = 0; pin < 4; pin++, intpin++)
572 			if (intpin->link != 0) {
573 				if (entry->pe_slot == 0)
574 					printf("embedded ");
575 				else
576 					printf("slot %-3d ", entry->pe_slot);
577 				printf(" %3d  %3d    %c   0x%02x  ",
578 				    entry->pe_bus, entry->pe_device,
579 				    'A' + pin, intpin->link);
580 				pci_print_irqmask(intpin->irqs);
581 				printf("\n");
582 			}
583 	}
584 }
585 
586 /*
587  * See if any interrupts for a given PCI bus are routed in the PIR.  Don't
588  * even bother looking if the BIOS doesn't support routing anyways.
589  */
590 int
591 pci_probe_route_table(int bus)
592 {
593 	int i;
594 	u_int16_t v;
595 
596 	v = pcibios_get_version();
597 	if (v < 0x0210)
598 		return (0);
599 	for (i = 0; i < pci_route_count; i++)
600 		if (pci_route_table->pt_entry[i].pe_bus == bus)
601 			return (1);
602 	return (0);
603 }
604 
605 #ifdef USE_PCI_BIOS_FOR_READ_WRITE
606 /*
607  * Config space access using BIOS functions
608  */
609 static int
610 pcibios_cfgread(int bus, int slot, int func, int reg, int bytes)
611 {
612 	struct bios_regs args;
613 	u_int mask;
614 
615 	switch(bytes) {
616 	case 1:
617 		args.eax = PCIBIOS_READ_CONFIG_BYTE;
618 		mask = 0xff;
619 		break;
620 	case 2:
621 		args.eax = PCIBIOS_READ_CONFIG_WORD;
622 		mask = 0xffff;
623 		break;
624 	case 4:
625 		args.eax = PCIBIOS_READ_CONFIG_DWORD;
626 		mask = 0xffffffff;
627 		break;
628 	default:
629 		return(-1);
630 	}
631 	args.ebx = (bus << 8) | (slot << 3) | func;
632 	args.edi = reg;
633 	bios32(&args, PCIbios.ventry, GSEL(GCODE_SEL, SEL_KPL));
634 	/* check call results? */
635 	return(args.ecx & mask);
636 }
637 
638 static void
639 pcibios_cfgwrite(int bus, int slot, int func, int reg, int data, int bytes)
640 {
641 	struct bios_regs args;
642 
643 	switch(bytes) {
644 	case 1:
645 		args.eax = PCIBIOS_WRITE_CONFIG_BYTE;
646 		break;
647 	case 2:
648 		args.eax = PCIBIOS_WRITE_CONFIG_WORD;
649 		break;
650 	case 4:
651 		args.eax = PCIBIOS_WRITE_CONFIG_DWORD;
652 		break;
653 	default:
654 		return;
655 	}
656 	args.ebx = (bus << 8) | (slot << 3) | func;
657 	args.ecx = data;
658 	args.edi = reg;
659 	bios32(&args, PCIbios.ventry, GSEL(GCODE_SEL, SEL_KPL));
660 }
661 #endif
662 
663 /*
664  * Determine whether there is a PCI BIOS present
665  */
666 static int
667 pcibios_cfgopen(void)
668 {
669 	u_int16_t		v = 0;
670 
671 	if (PCIbios.ventry != 0 && enable_pcibios) {
672 		v = pcibios_get_version();
673 		if (v > 0)
674 			printf("pcibios: BIOS version %x.%02x\n",
675 			    (v & 0xff00) >> 8, v & 0xff);
676 	}
677 	return (v > 0);
678 }
679 
680 /*
681  * Configuration space access using direct register operations
682  */
683 
684 /* enable configuration space accesses and return data port address */
685 static int
686 pci_cfgenable(unsigned bus, unsigned slot, unsigned func, int reg, int bytes)
687 {
688 	int dataport = 0;
689 
690 	if (bus <= PCI_BUSMAX
691 	    && slot < devmax
692 	    && func <= PCI_FUNCMAX
693 	    && reg <= PCI_REGMAX
694 	    && bytes != 3
695 	    && (unsigned) bytes <= 4
696 	    && (reg & (bytes -1)) == 0) {
697 		switch (cfgmech) {
698 		case 1:
699 			outl(CONF1_ADDR_PORT, (1 << 31)
700 			    | (bus << 16) | (slot << 11)
701 			    | (func << 8) | (reg & ~0x03));
702 			dataport = CONF1_DATA_PORT + (reg & 0x03);
703 			break;
704 		case 2:
705 			outb(CONF2_ENABLE_PORT, 0xf0 | (func << 1));
706 			outb(CONF2_FORWARD_PORT, bus);
707 			dataport = 0xc000 | (slot << 8) | reg;
708 			break;
709 		}
710 	}
711 	return (dataport);
712 }
713 
714 /* disable configuration space accesses */
715 static void
716 pci_cfgdisable(void)
717 {
718 	switch (cfgmech) {
719 	case 1:
720 		outl(CONF1_ADDR_PORT, 0);
721 		break;
722 	case 2:
723 		outb(CONF2_ENABLE_PORT, 0);
724 		outb(CONF2_FORWARD_PORT, 0);
725 		break;
726 	}
727 }
728 
729 static int
730 pcireg_cfgread(int bus, int slot, int func, int reg, int bytes)
731 {
732 	int data = -1;
733 	int port;
734 
735 	port = pci_cfgenable(bus, slot, func, reg, bytes);
736 
737 	if (port != 0) {
738 		switch (bytes) {
739 		case 1:
740 			data = inb(port);
741 			break;
742 		case 2:
743 			data = inw(port);
744 			break;
745 		case 4:
746 			data = inl(port);
747 			break;
748 		}
749 		pci_cfgdisable();
750 	}
751 	return (data);
752 }
753 
754 static void
755 pcireg_cfgwrite(int bus, int slot, int func, int reg, int data, int bytes)
756 {
757 	int port;
758 
759 	port = pci_cfgenable(bus, slot, func, reg, bytes);
760 	if (port != 0) {
761 		switch (bytes) {
762 		case 1:
763 			outb(port, data);
764 			break;
765 		case 2:
766 			outw(port, data);
767 			break;
768 		case 4:
769 			outl(port, data);
770 			break;
771 		}
772 		pci_cfgdisable();
773 	}
774 }
775 
776 /* check whether the configuration mechanism has been correctly identified */
777 static int
778 pci_cfgcheck(int maxdev)
779 {
780 	u_char device;
781 
782 	if (bootverbose)
783 		printf("pci_cfgcheck:\tdevice ");
784 
785 	for (device = 0; device < maxdev; device++) {
786 		unsigned id, class, header;
787 		if (bootverbose)
788 			printf("%d ", device);
789 
790 		id = inl(pci_cfgenable(0, device, 0, 0, 4));
791 		if (id == 0 || id == -1)
792 			continue;
793 
794 		class = inl(pci_cfgenable(0, device, 0, 8, 4)) >> 8;
795 		if (bootverbose)
796 			printf("[class=%06x] ", class);
797 		if (class == 0 || (class & 0xf870ff) != 0)
798 			continue;
799 
800 		header = inb(pci_cfgenable(0, device, 0, 14, 1));
801 		if (bootverbose)
802 			printf("[hdr=%02x] ", header);
803 		if ((header & 0x7e) != 0)
804 			continue;
805 
806 		if (bootverbose)
807 			printf("is there (id=%08x)\n", id);
808 
809 		pci_cfgdisable();
810 		return (1);
811 	}
812 	if (bootverbose)
813 		printf("-- nothing found\n");
814 
815 	pci_cfgdisable();
816 	return (0);
817 }
818 
819 static int
820 pcireg_cfgopen(void)
821 {
822 	unsigned long mode1res,oldval1;
823 	unsigned char mode2res,oldval2;
824 
825 	oldval1 = inl(CONF1_ADDR_PORT);
826 
827 	if (bootverbose) {
828 		printf("pci_open(1):\tmode 1 addr port (0x0cf8) is 0x%08lx\n",
829 		    oldval1);
830 	}
831 
832 	if ((oldval1 & CONF1_ENABLE_MSK) == 0) {
833 
834 		cfgmech = 1;
835 		devmax = 32;
836 
837 		outl(CONF1_ADDR_PORT, CONF1_ENABLE_CHK);
838 		outb(CONF1_ADDR_PORT +3, 0);
839 		mode1res = inl(CONF1_ADDR_PORT);
840 		outl(CONF1_ADDR_PORT, oldval1);
841 
842 		if (bootverbose)
843 			printf("pci_open(1a):\tmode1res=0x%08lx (0x%08lx)\n",
844 			    mode1res, CONF1_ENABLE_CHK);
845 
846 		if (mode1res) {
847 			if (pci_cfgcheck(32))
848 				return (cfgmech);
849 		}
850 
851 		outl(CONF1_ADDR_PORT, CONF1_ENABLE_CHK1);
852 		mode1res = inl(CONF1_ADDR_PORT);
853 		outl(CONF1_ADDR_PORT, oldval1);
854 
855 		if (bootverbose)
856 			printf("pci_open(1b):\tmode1res=0x%08lx (0x%08lx)\n",
857 			    mode1res, CONF1_ENABLE_CHK1);
858 
859 		if ((mode1res & CONF1_ENABLE_MSK1) == CONF1_ENABLE_RES1) {
860 			if (pci_cfgcheck(32))
861 				return (cfgmech);
862 		}
863 	}
864 
865 	oldval2 = inb(CONF2_ENABLE_PORT);
866 
867 	if (bootverbose) {
868 		printf("pci_open(2):\tmode 2 enable port (0x0cf8) is 0x%02x\n",
869 		    oldval2);
870 	}
871 
872 	if ((oldval2 & 0xf0) == 0) {
873 
874 		cfgmech = 2;
875 		devmax = 16;
876 
877 		outb(CONF2_ENABLE_PORT, CONF2_ENABLE_CHK);
878 		mode2res = inb(CONF2_ENABLE_PORT);
879 		outb(CONF2_ENABLE_PORT, oldval2);
880 
881 		if (bootverbose)
882 			printf("pci_open(2a):\tmode2res=0x%02x (0x%02x)\n",
883 			    mode2res, CONF2_ENABLE_CHK);
884 
885 		if (mode2res == CONF2_ENABLE_RES) {
886 			if (bootverbose)
887 				printf("pci_open(2a):\tnow trying mechanism 2\n");
888 
889 			if (pci_cfgcheck(16))
890 				return (cfgmech);
891 		}
892 	}
893 
894 	cfgmech = 0;
895 	devmax = 0;
896 	return (cfgmech);
897 }
898 
899