xref: /netbsd-src/sys/arch/x86/pci/pci_machdep.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: pci_machdep.c,v 1.44 2010/04/30 21:05:27 dyoung Exp $	*/
2 
3 /*-
4  * Copyright (c) 1997, 1998 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9  * NASA Ames Research Center.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 /*
34  * Copyright (c) 1996 Christopher G. Demetriou.  All rights reserved.
35  * Copyright (c) 1994 Charles M. Hannum.  All rights reserved.
36  *
37  * Redistribution and use in source and binary forms, with or without
38  * modification, are permitted provided that the following conditions
39  * are met:
40  * 1. Redistributions of source code must retain the above copyright
41  *    notice, this list of conditions and the following disclaimer.
42  * 2. Redistributions in binary form must reproduce the above copyright
43  *    notice, this list of conditions and the following disclaimer in the
44  *    documentation and/or other materials provided with the distribution.
45  * 3. All advertising materials mentioning features or use of this software
46  *    must display the following acknowledgement:
47  *	This product includes software developed by Charles M. Hannum.
48  * 4. The name of the author may not be used to endorse or promote products
49  *    derived from this software without specific prior written permission.
50  *
51  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
52  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
53  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
54  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
55  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
56  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
57  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
58  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
59  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
60  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
61  */
62 
63 /*
64  * Machine-specific functions for PCI autoconfiguration.
65  *
66  * On PCs, there are two methods of generating PCI configuration cycles.
67  * We try to detect the appropriate mechanism for this machine and set
68  * up a few function pointers to access the correct method directly.
69  *
70  * The configuration method can be hard-coded in the config file by
71  * using `options PCI_CONF_MODE=N', where `N' is the configuration mode
72  * as defined section 3.6.4.1, `Generating Configuration Cycles'.
73  */
74 
75 #include <sys/cdefs.h>
76 __KERNEL_RCSID(0, "$NetBSD: pci_machdep.c,v 1.44 2010/04/30 21:05:27 dyoung Exp $");
77 
78 #include <sys/types.h>
79 #include <sys/param.h>
80 #include <sys/time.h>
81 #include <sys/systm.h>
82 #include <sys/errno.h>
83 #include <sys/device.h>
84 #include <sys/bus.h>
85 #include <sys/cpu.h>
86 #include <sys/kmem.h>
87 
88 #include <uvm/uvm_extern.h>
89 
90 #include <machine/bus_private.h>
91 
92 #include <machine/pio.h>
93 #include <machine/lock.h>
94 
95 #include <dev/isa/isareg.h>
96 #include <dev/isa/isavar.h>
97 #include <dev/pci/pcivar.h>
98 #include <dev/pci/pcireg.h>
99 #include <dev/pci/pccbbreg.h>
100 #include <dev/pci/pcidevs.h>
101 
102 #include "acpica.h"
103 #include "opt_mpbios.h"
104 #include "opt_acpi.h"
105 
106 #ifdef MPBIOS
107 #include <machine/mpbiosvar.h>
108 #endif
109 
110 #if NACPICA > 0
111 #include <machine/mpacpi.h>
112 #endif
113 
114 #include <machine/mpconfig.h>
115 
116 #include "opt_pci_conf_mode.h"
117 
118 #ifdef __i386__
119 #include "opt_xbox.h"
120 #ifdef XBOX
121 #include <machine/xbox.h>
122 #endif
123 #endif
124 
125 #ifdef PCI_CONF_MODE
126 #if (PCI_CONF_MODE == 1) || (PCI_CONF_MODE == 2)
127 static int pci_mode = PCI_CONF_MODE;
128 #else
129 #error Invalid PCI configuration mode.
130 #endif
131 #else
132 static int pci_mode = -1;
133 #endif
134 
135 struct pci_conf_lock {
136 	uint32_t cl_cpuno;	/* 0: unlocked
137 				 * 1 + n: locked by CPU n (0 <= n)
138 				 */
139 	uint32_t cl_sel;	/* the address that's being read. */
140 };
141 
142 static void pci_conf_unlock(struct pci_conf_lock *);
143 static uint32_t pci_conf_selector(pcitag_t, int);
144 static unsigned int pci_conf_port(pcitag_t, int);
145 static void pci_conf_select(uint32_t);
146 static void pci_conf_lock(struct pci_conf_lock *, uint32_t);
147 static void pci_bridge_hook(pci_chipset_tag_t, pcitag_t, void *);
148 struct pci_bridge_hook_arg {
149 	void (*func)(pci_chipset_tag_t, pcitag_t, void *);
150 	void *arg;
151 };
152 
153 #define	PCI_MODE1_ENABLE	0x80000000UL
154 #define	PCI_MODE1_ADDRESS_REG	0x0cf8
155 #define	PCI_MODE1_DATA_REG	0x0cfc
156 
157 #define	PCI_MODE2_ENABLE_REG	0x0cf8
158 #define	PCI_MODE2_FORWARD_REG	0x0cfa
159 
160 #define _m1tag(b, d, f) \
161 	(PCI_MODE1_ENABLE | ((b) << 16) | ((d) << 11) | ((f) << 8))
162 #define _qe(bus, dev, fcn, vend, prod) \
163 	{_m1tag(bus, dev, fcn), PCI_ID_CODE(vend, prod)}
164 struct {
165 	uint32_t tag;
166 	pcireg_t id;
167 } pcim1_quirk_tbl[] = {
168 	_qe(0, 0, 0, PCI_VENDOR_COMPAQ, PCI_PRODUCT_COMPAQ_TRIFLEX1),
169 	/* XXX Triflex2 not tested */
170 	_qe(0, 0, 0, PCI_VENDOR_COMPAQ, PCI_PRODUCT_COMPAQ_TRIFLEX2),
171 	_qe(0, 0, 0, PCI_VENDOR_COMPAQ, PCI_PRODUCT_COMPAQ_TRIFLEX4),
172 	/* Triton needed for Connectix Virtual PC */
173 	_qe(0, 0, 0, PCI_VENDOR_INTEL, PCI_PRODUCT_INTEL_82437FX),
174 	/* Connectix Virtual PC 5 has a 440BX */
175 	_qe(0, 0, 0, PCI_VENDOR_INTEL, PCI_PRODUCT_INTEL_82443BX_NOAGP),
176 	/* Parallels Desktop for Mac */
177 	_qe(0, 2, 0, PCI_VENDOR_PARALLELS, PCI_PRODUCT_PARALLELS_VIDEO),
178 	_qe(0, 3, 0, PCI_VENDOR_PARALLELS, PCI_PRODUCT_PARALLELS_TOOLS),
179 	/* SIS 740 */
180 	_qe(0, 0, 0, PCI_VENDOR_SIS, PCI_PRODUCT_SIS_740),
181 	/* SIS 741 */
182 	_qe(0, 0, 0, PCI_VENDOR_SIS, PCI_PRODUCT_SIS_741),
183 	{0, 0xffffffff} /* patchable */
184 };
185 #undef _m1tag
186 #undef _id
187 #undef _qe
188 
189 /*
190  * PCI doesn't have any special needs; just use the generic versions
191  * of these functions.
192  */
193 struct x86_bus_dma_tag pci_bus_dma_tag = {
194 	0,				/* tag_needs_free */
195 #if defined(_LP64) || defined(PAE)
196 	PCI32_DMA_BOUNCE_THRESHOLD,	/* bounce_thresh */
197 	ISA_DMA_BOUNCE_THRESHOLD,	/* bounce_alloclo */
198 	PCI32_DMA_BOUNCE_THRESHOLD,	/* bounce_allochi */
199 #else
200 	0,
201 	0,
202 	0,
203 #endif
204 	NULL,			/* _may_bounce */
205 	_bus_dmamap_create,
206 	_bus_dmamap_destroy,
207 	_bus_dmamap_load,
208 	_bus_dmamap_load_mbuf,
209 	_bus_dmamap_load_uio,
210 	_bus_dmamap_load_raw,
211 	_bus_dmamap_unload,
212 	_bus_dmamap_sync,
213 	_bus_dmamem_alloc,
214 	_bus_dmamem_free,
215 	_bus_dmamem_map,
216 	_bus_dmamem_unmap,
217 	_bus_dmamem_mmap,
218 	_bus_dmatag_subregion,
219 	_bus_dmatag_destroy,
220 };
221 
222 #ifdef _LP64
223 struct x86_bus_dma_tag pci_bus_dma64_tag = {
224 	0,				/* tag_needs_free */
225 	0,
226 	0,
227 	0,
228 	NULL,			/* _may_bounce */
229 	_bus_dmamap_create,
230 	_bus_dmamap_destroy,
231 	_bus_dmamap_load,
232 	_bus_dmamap_load_mbuf,
233 	_bus_dmamap_load_uio,
234 	_bus_dmamap_load_raw,
235 	_bus_dmamap_unload,
236 	NULL,
237 	_bus_dmamem_alloc,
238 	_bus_dmamem_free,
239 	_bus_dmamem_map,
240 	_bus_dmamem_unmap,
241 	_bus_dmamem_mmap,
242 	_bus_dmatag_subregion,
243 	_bus_dmatag_destroy,
244 };
245 #endif
246 
247 static struct pci_conf_lock cl0 = {
248 	  .cl_cpuno = 0UL
249 	, .cl_sel = 0UL
250 };
251 
252 static struct pci_conf_lock * const cl = &cl0;
253 
254 static void
255 pci_conf_lock(struct pci_conf_lock *ocl, uint32_t sel)
256 {
257 	uint32_t cpuno;
258 
259 	KASSERT(sel != 0);
260 
261 	kpreempt_disable();
262 	cpuno = cpu_number() + 1;
263 	/* If the kernel enters pci_conf_lock() through an interrupt
264 	 * handler, then the CPU may already hold the lock.
265 	 *
266 	 * If the CPU does not already hold the lock, spin until
267 	 * we can acquire it.
268 	 */
269 	if (cpuno == cl->cl_cpuno) {
270 		ocl->cl_cpuno = cpuno;
271 	} else {
272 		u_int spins;
273 
274 		ocl->cl_cpuno = 0;
275 
276 		spins = SPINLOCK_BACKOFF_MIN;
277 		while (atomic_cas_32(&cl->cl_cpuno, 0, cpuno) != 0) {
278 			SPINLOCK_BACKOFF(spins);
279 #ifdef LOCKDEBUG
280 			if (SPINLOCK_SPINOUT(spins)) {
281 				panic("%s: cpu %" PRId32
282 				    " spun out waiting for cpu %" PRId32,
283 				    __func__, cpuno, cl->cl_cpuno);
284 			}
285 #endif	/* LOCKDEBUG */
286 		}
287 	}
288 
289 	/* Only one CPU can be here, so an interlocked atomic_swap(3)
290 	 * is not necessary.
291 	 *
292 	 * Evaluating atomic_cas_32_ni()'s argument, cl->cl_sel,
293 	 * and applying atomic_cas_32_ni() is not an atomic operation,
294 	 * however, any interrupt that, in the middle of the
295 	 * operation, modifies cl->cl_sel, will also restore
296 	 * cl->cl_sel.  So cl->cl_sel will have the same value when
297 	 * we apply atomic_cas_32_ni() as when we evaluated it,
298 	 * before.
299 	 */
300 	ocl->cl_sel = atomic_cas_32_ni(&cl->cl_sel, cl->cl_sel, sel);
301 	pci_conf_select(sel);
302 }
303 
304 static void
305 pci_conf_unlock(struct pci_conf_lock *ocl)
306 {
307 	uint32_t sel;
308 
309 	sel = atomic_cas_32_ni(&cl->cl_sel, cl->cl_sel, ocl->cl_sel);
310 	pci_conf_select(ocl->cl_sel);
311 	if (ocl->cl_cpuno != cl->cl_cpuno)
312 		atomic_cas_32(&cl->cl_cpuno, cl->cl_cpuno, ocl->cl_cpuno);
313 	kpreempt_enable();
314 }
315 
316 static uint32_t
317 pci_conf_selector(pcitag_t tag, int reg)
318 {
319 	static const pcitag_t mode2_mask = {
320 		.mode2 = {
321 			  .enable = 0xff
322 			, .forward = 0xff
323 		}
324 	};
325 
326 	switch (pci_mode) {
327 	case 1:
328 		return tag.mode1 | reg;
329 	case 2:
330 		return tag.mode1 & mode2_mask.mode1;
331 	default:
332 		panic("%s: mode not configured", __func__);
333 	}
334 }
335 
336 static unsigned int
337 pci_conf_port(pcitag_t tag, int reg)
338 {
339 	switch (pci_mode) {
340 	case 1:
341 		return PCI_MODE1_DATA_REG;
342 	case 2:
343 		return tag.mode2.port | reg;
344 	default:
345 		panic("%s: mode not configured", __func__);
346 	}
347 }
348 
349 static void
350 pci_conf_select(uint32_t sel)
351 {
352 	pcitag_t tag;
353 
354 	switch (pci_mode) {
355 	case 1:
356 		outl(PCI_MODE1_ADDRESS_REG, sel);
357 		return;
358 	case 2:
359 		tag.mode1 = sel;
360 		outb(PCI_MODE2_ENABLE_REG, tag.mode2.enable);
361 		if (tag.mode2.enable != 0)
362 			outb(PCI_MODE2_FORWARD_REG, tag.mode2.forward);
363 		return;
364 	default:
365 		panic("%s: mode not configured", __func__);
366 	}
367 }
368 
369 void
370 pci_attach_hook(device_t parent, device_t self, struct pcibus_attach_args *pba)
371 {
372 
373 	if (pba->pba_bus == 0)
374 		aprint_normal(": configuration mode %d", pci_mode);
375 #ifdef MPBIOS
376 	mpbios_pci_attach_hook(parent, self, pba);
377 #endif
378 #if NACPICA > 0
379 	mpacpi_pci_attach_hook(parent, self, pba);
380 #endif
381 }
382 
383 int
384 pci_bus_maxdevs(pci_chipset_tag_t pc, int busno)
385 {
386 
387 #if defined(__i386__) && defined(XBOX)
388 	/*
389 	 * Scanning above the first device is fatal on the Microsoft Xbox.
390 	 * If busno=1, only allow for one device.
391 	 */
392 	if (arch_i386_is_xbox) {
393 		if (busno == 1)
394 			return 1;
395 		else if (busno > 1)
396 			return 0;
397 	}
398 #endif
399 
400 	/*
401 	 * Bus number is irrelevant.  If Configuration Mechanism 2 is in
402 	 * use, can only have devices 0-15 on any bus.  If Configuration
403 	 * Mechanism 1 is in use, can have devices 0-32 (i.e. the `normal'
404 	 * range).
405 	 */
406 	if (pci_mode == 2)
407 		return (16);
408 	else
409 		return (32);
410 }
411 
412 pcitag_t
413 pci_make_tag(pci_chipset_tag_t pc, int bus, int device, int function)
414 {
415 	pcitag_t tag;
416 
417 	if (pc != NULL) {
418 		if ((pc->pc_present & PCI_OVERRIDE_MAKE_TAG) != 0) {
419 			return (*pc->pc_ov->ov_make_tag)(pc->pc_ctx,
420 			    pc, bus, device, function);
421 		}
422 		if (pc->pc_super != NULL) {
423 			return pci_make_tag(pc->pc_super, bus, device,
424 			    function);
425 		}
426 	}
427 
428 	switch (pci_mode) {
429 	case 1:
430 		if (bus >= 256 || device >= 32 || function >= 8)
431 			panic("%s: bad request", __func__);
432 
433 		tag.mode1 = PCI_MODE1_ENABLE |
434 			    (bus << 16) | (device << 11) | (function << 8);
435 		return tag;
436 	case 2:
437 		if (bus >= 256 || device >= 16 || function >= 8)
438 			panic("%s: bad request", __func__);
439 
440 		tag.mode2.port = 0xc000 | (device << 8);
441 		tag.mode2.enable = 0xf0 | (function << 1);
442 		tag.mode2.forward = bus;
443 		return tag;
444 	default:
445 		panic("%s: mode not configured", __func__);
446 	}
447 }
448 
449 void
450 pci_decompose_tag(pci_chipset_tag_t pc, pcitag_t tag,
451     int *bp, int *dp, int *fp)
452 {
453 
454 	if (pc != NULL) {
455 		if ((pc->pc_present & PCI_OVERRIDE_DECOMPOSE_TAG) != 0) {
456 			(*pc->pc_ov->ov_decompose_tag)(pc->pc_ctx,
457 			    pc, tag, bp, dp, fp);
458 			return;
459 		}
460 		if (pc->pc_super != NULL) {
461 			pci_decompose_tag(pc->pc_super, tag, bp, dp, fp);
462 			return;
463 		}
464 	}
465 
466 	switch (pci_mode) {
467 	case 1:
468 		if (bp != NULL)
469 			*bp = (tag.mode1 >> 16) & 0xff;
470 		if (dp != NULL)
471 			*dp = (tag.mode1 >> 11) & 0x1f;
472 		if (fp != NULL)
473 			*fp = (tag.mode1 >> 8) & 0x7;
474 		return;
475 	case 2:
476 		if (bp != NULL)
477 			*bp = tag.mode2.forward & 0xff;
478 		if (dp != NULL)
479 			*dp = (tag.mode2.port >> 8) & 0xf;
480 		if (fp != NULL)
481 			*fp = (tag.mode2.enable >> 1) & 0x7;
482 		return;
483 	default:
484 		panic("%s: mode not configured", __func__);
485 	}
486 }
487 
488 pcireg_t
489 pci_conf_read(pci_chipset_tag_t pc, pcitag_t tag, int reg)
490 {
491 	pcireg_t data;
492 	struct pci_conf_lock ocl;
493 
494 	KASSERT((reg & 0x3) == 0);
495 
496 	if (pc != NULL) {
497 		if ((pc->pc_present & PCI_OVERRIDE_CONF_READ) != 0) {
498 			return (*pc->pc_ov->ov_conf_read)(pc->pc_ctx,
499 			    pc, tag, reg);
500 		}
501 		if (pc->pc_super != NULL)
502 			return pci_conf_read(pc->pc_super, tag, reg);
503 	}
504 
505 #if defined(__i386__) && defined(XBOX)
506 	if (arch_i386_is_xbox) {
507 		int bus, dev, fn;
508 		pci_decompose_tag(pc, tag, &bus, &dev, &fn);
509 		if (bus == 0 && dev == 0 && (fn == 1 || fn == 2))
510 			return (pcireg_t)-1;
511 	}
512 #endif
513 
514 	pci_conf_lock(&ocl, pci_conf_selector(tag, reg));
515 	data = inl(pci_conf_port(tag, reg));
516 	pci_conf_unlock(&ocl);
517 	return data;
518 }
519 
520 void
521 pci_conf_write(pci_chipset_tag_t pc, pcitag_t tag, int reg, pcireg_t data)
522 {
523 	struct pci_conf_lock ocl;
524 
525 	KASSERT((reg & 0x3) == 0);
526 
527 	if (pc != NULL) {
528 		if ((pc->pc_present & PCI_OVERRIDE_CONF_WRITE) != 0) {
529 			(*pc->pc_ov->ov_conf_write)(pc->pc_ctx, pc, tag, reg,
530 			    data);
531 			return;
532 		}
533 		if (pc->pc_super != NULL) {
534 			pci_conf_write(pc->pc_super, tag, reg, data);
535 			return;
536 		}
537 	}
538 
539 #if defined(__i386__) && defined(XBOX)
540 	if (arch_i386_is_xbox) {
541 		int bus, dev, fn;
542 		pci_decompose_tag(pc, tag, &bus, &dev, &fn);
543 		if (bus == 0 && dev == 0 && (fn == 1 || fn == 2))
544 			return;
545 	}
546 #endif
547 
548 	pci_conf_lock(&ocl, pci_conf_selector(tag, reg));
549 	outl(pci_conf_port(tag, reg), data);
550 	pci_conf_unlock(&ocl);
551 }
552 
553 void
554 pci_mode_set(int mode)
555 {
556 	KASSERT(pci_mode == -1 || pci_mode == mode);
557 
558 	pci_mode = mode;
559 }
560 
561 int
562 pci_mode_detect(void)
563 {
564 	uint32_t sav, val;
565 	int i;
566 	pcireg_t idreg;
567 
568 	if (pci_mode != -1)
569 		return pci_mode;
570 
571 	/*
572 	 * We try to divine which configuration mode the host bridge wants.
573 	 */
574 
575 	sav = inl(PCI_MODE1_ADDRESS_REG);
576 
577 	pci_mode = 1; /* assume this for now */
578 	/*
579 	 * catch some known buggy implementations of mode 1
580 	 */
581 	for (i = 0; i < __arraycount(pcim1_quirk_tbl); i++) {
582 		pcitag_t t;
583 
584 		if (!pcim1_quirk_tbl[i].tag)
585 			break;
586 		t.mode1 = pcim1_quirk_tbl[i].tag;
587 		idreg = pci_conf_read(0, t, PCI_ID_REG); /* needs "pci_mode" */
588 		if (idreg == pcim1_quirk_tbl[i].id) {
589 #ifdef DEBUG
590 			printf("known mode 1 PCI chipset (%08x)\n",
591 			       idreg);
592 #endif
593 			return (pci_mode);
594 		}
595 	}
596 
597 	/*
598 	 * Strong check for standard compliant mode 1:
599 	 * 1. bit 31 ("enable") can be set
600 	 * 2. byte/word access does not affect register
601 	 */
602 	outl(PCI_MODE1_ADDRESS_REG, PCI_MODE1_ENABLE);
603 	outb(PCI_MODE1_ADDRESS_REG + 3, 0);
604 	outw(PCI_MODE1_ADDRESS_REG + 2, 0);
605 	val = inl(PCI_MODE1_ADDRESS_REG);
606 	if ((val & 0x80fffffc) != PCI_MODE1_ENABLE) {
607 #ifdef DEBUG
608 		printf("pci_mode_detect: mode 1 enable failed (%x)\n",
609 		       val);
610 #endif
611 		goto not1;
612 	}
613 	outl(PCI_MODE1_ADDRESS_REG, 0);
614 	val = inl(PCI_MODE1_ADDRESS_REG);
615 	if ((val & 0x80fffffc) != 0)
616 		goto not1;
617 	return (pci_mode);
618 not1:
619 	outl(PCI_MODE1_ADDRESS_REG, sav);
620 
621 	/*
622 	 * This mode 2 check is quite weak (and known to give false
623 	 * positives on some Compaq machines).
624 	 * However, this doesn't matter, because this is the
625 	 * last test, and simply no PCI devices will be found if
626 	 * this happens.
627 	 */
628 	outb(PCI_MODE2_ENABLE_REG, 0);
629 	outb(PCI_MODE2_FORWARD_REG, 0);
630 	if (inb(PCI_MODE2_ENABLE_REG) != 0 ||
631 	    inb(PCI_MODE2_FORWARD_REG) != 0)
632 		goto not2;
633 	return (pci_mode = 2);
634 not2:
635 
636 	return (pci_mode = 0);
637 }
638 
639 /*
640  * Determine which flags should be passed to the primary PCI bus's
641  * autoconfiguration node.  We use this to detect broken chipsets
642  * which cannot safely use memory-mapped device access.
643  */
644 int
645 pci_bus_flags(void)
646 {
647 	int rval = PCI_FLAGS_IO_ENABLED | PCI_FLAGS_MEM_ENABLED |
648 	    PCI_FLAGS_MRL_OKAY | PCI_FLAGS_MRM_OKAY | PCI_FLAGS_MWI_OKAY;
649 	int device, maxndevs;
650 	pcitag_t tag;
651 	pcireg_t id;
652 
653 	maxndevs = pci_bus_maxdevs(NULL, 0);
654 
655 	for (device = 0; device < maxndevs; device++) {
656 		tag = pci_make_tag(NULL, 0, device, 0);
657 		id = pci_conf_read(NULL, tag, PCI_ID_REG);
658 
659 		/* Invalid vendor ID value? */
660 		if (PCI_VENDOR(id) == PCI_VENDOR_INVALID)
661 			continue;
662 		/* XXX Not invalid, but we've done this ~forever. */
663 		if (PCI_VENDOR(id) == 0)
664 			continue;
665 
666 		switch (PCI_VENDOR(id)) {
667 		case PCI_VENDOR_SIS:
668 			switch (PCI_PRODUCT(id)) {
669 			case PCI_PRODUCT_SIS_85C496:
670 				goto disable_mem;
671 			}
672 			break;
673 		}
674 	}
675 
676 	return (rval);
677 
678  disable_mem:
679 	printf("Warning: broken PCI-Host bridge detected; "
680 	    "disabling memory-mapped access\n");
681 	rval &= ~(PCI_FLAGS_MEM_ENABLED|PCI_FLAGS_MRL_OKAY|PCI_FLAGS_MRM_OKAY|
682 	    PCI_FLAGS_MWI_OKAY);
683 	return (rval);
684 }
685 
686 void
687 pci_device_foreach(pci_chipset_tag_t pc, int maxbus,
688 	void (*func)(pci_chipset_tag_t, pcitag_t, void *), void *context)
689 {
690 	pci_device_foreach_min(pc, 0, maxbus, func, context);
691 }
692 
693 void
694 pci_device_foreach_min(pci_chipset_tag_t pc, int minbus, int maxbus,
695 	void (*func)(pci_chipset_tag_t, pcitag_t, void *), void *context)
696 {
697 	const struct pci_quirkdata *qd;
698 	int bus, device, function, maxdevs, nfuncs;
699 	pcireg_t id, bhlcr;
700 	pcitag_t tag;
701 
702 	for (bus = minbus; bus <= maxbus; bus++) {
703 		maxdevs = pci_bus_maxdevs(pc, bus);
704 		for (device = 0; device < maxdevs; device++) {
705 			tag = pci_make_tag(pc, bus, device, 0);
706 			id = pci_conf_read(pc, tag, PCI_ID_REG);
707 
708 			/* Invalid vendor ID value? */
709 			if (PCI_VENDOR(id) == PCI_VENDOR_INVALID)
710 				continue;
711 			/* XXX Not invalid, but we've done this ~forever. */
712 			if (PCI_VENDOR(id) == 0)
713 				continue;
714 
715 			qd = pci_lookup_quirkdata(PCI_VENDOR(id),
716 				PCI_PRODUCT(id));
717 
718 			bhlcr = pci_conf_read(pc, tag, PCI_BHLC_REG);
719 			if (PCI_HDRTYPE_MULTIFN(bhlcr) ||
720 			     (qd != NULL &&
721 		  	     (qd->quirks & PCI_QUIRK_MULTIFUNCTION) != 0))
722 				nfuncs = 8;
723 			else
724 				nfuncs = 1;
725 
726 			for (function = 0; function < nfuncs; function++) {
727 				tag = pci_make_tag(pc, bus, device, function);
728 				id = pci_conf_read(pc, tag, PCI_ID_REG);
729 
730 				/* Invalid vendor ID value? */
731 				if (PCI_VENDOR(id) == PCI_VENDOR_INVALID)
732 					continue;
733 				/*
734 				 * XXX Not invalid, but we've done this
735 				 * ~forever.
736 				 */
737 				if (PCI_VENDOR(id) == 0)
738 					continue;
739 				(*func)(pc, tag, context);
740 			}
741 		}
742 	}
743 }
744 
745 void
746 pci_bridge_foreach(pci_chipset_tag_t pc, int minbus, int maxbus,
747 	void (*func)(pci_chipset_tag_t, pcitag_t, void *), void *ctx)
748 {
749 	struct pci_bridge_hook_arg bridge_hook;
750 
751 	bridge_hook.func = func;
752 	bridge_hook.arg = ctx;
753 
754 	pci_device_foreach_min(pc, minbus, maxbus, pci_bridge_hook,
755 		&bridge_hook);
756 }
757 
758 static void
759 pci_bridge_hook(pci_chipset_tag_t pc, pcitag_t tag, void *ctx)
760 {
761 	struct pci_bridge_hook_arg *bridge_hook = (void *)ctx;
762 	pcireg_t reg;
763 
764 	reg = pci_conf_read(pc, tag, PCI_CLASS_REG);
765 	if (PCI_CLASS(reg) == PCI_CLASS_BRIDGE &&
766  	     (PCI_SUBCLASS(reg) == PCI_SUBCLASS_BRIDGE_PCI ||
767 		PCI_SUBCLASS(reg) == PCI_SUBCLASS_BRIDGE_CARDBUS)) {
768 		(*bridge_hook->func)(pc, tag, bridge_hook->arg);
769 	}
770 }
771 
772 static const void *
773 bit_to_function_pointer(const struct pci_overrides *ov, uint64_t bit)
774 {
775 	switch (bit) {
776 	case PCI_OVERRIDE_CONF_READ:
777 		return ov->ov_conf_read;
778 	case PCI_OVERRIDE_CONF_WRITE:
779 		return ov->ov_conf_write;
780 	case PCI_OVERRIDE_INTR_MAP:
781 		return ov->ov_intr_map;
782 	case PCI_OVERRIDE_INTR_STRING:
783 		return ov->ov_intr_string;
784 	case PCI_OVERRIDE_INTR_EVCNT:
785 		return ov->ov_intr_evcnt;
786 	case PCI_OVERRIDE_INTR_ESTABLISH:
787 		return ov->ov_intr_establish;
788 	case PCI_OVERRIDE_INTR_DISESTABLISH:
789 		return ov->ov_intr_disestablish;
790 	case PCI_OVERRIDE_MAKE_TAG:
791 		return ov->ov_make_tag;
792 	case PCI_OVERRIDE_DECOMPOSE_TAG:
793 		return ov->ov_decompose_tag;
794 	default:
795 		return NULL;
796 	}
797 }
798 
799 void
800 pci_chipset_tag_destroy(pci_chipset_tag_t pc)
801 {
802 	kmem_free(pc, sizeof(struct pci_chipset_tag));
803 }
804 
805 int
806 pci_chipset_tag_create(pci_chipset_tag_t opc, const uint64_t present,
807     const struct pci_overrides *ov, void *ctx, pci_chipset_tag_t *pcp)
808 {
809 	uint64_t bit, bits, nbits;
810 	pci_chipset_tag_t pc;
811 	const void *fp;
812 
813 	if (ov == NULL || present == 0)
814 		return EINVAL;
815 
816 	pc = kmem_alloc(sizeof(struct pci_chipset_tag), KM_SLEEP);
817 
818 	if (pc == NULL)
819 		return ENOMEM;
820 
821 	pc->pc_super = opc;
822 
823 	for (bits = present; bits != 0; bits = nbits) {
824 		nbits = bits & (bits - 1);
825 		bit = nbits ^ bits;
826 		if ((fp = bit_to_function_pointer(ov, bit)) == NULL) {
827 			printf("%s: missing bit %" PRIx64 "\n", __func__, bit);
828 			goto einval;
829 		}
830 	}
831 
832 	pc->pc_ov = ov;
833 	pc->pc_present = present;
834 	pc->pc_ctx = ctx;
835 
836 	*pcp = pc;
837 
838 	return 0;
839 einval:
840 	kmem_free(pc, sizeof(struct pci_chipset_tag));
841 	return EINVAL;
842 }
843