xref: /netbsd-src/sys/dev/acpi/acpi_pci_link.c (revision 466a16a118933bd295a8a104f095714fadf9cf68)
1 /*	$NetBSD: acpi_pci_link.c,v 1.14 2008/11/17 23:29:49 joerg Exp $	*/
2 
3 /*-
4  * Copyright (c) 2002 Mitsuru IWASAKI <iwasaki@jp.freebsd.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __KERNEL_RCSID(0, "$NetBSD: acpi_pci_link.c,v 1.14 2008/11/17 23:29:49 joerg Exp $");
31 
32 #include "opt_acpi.h"
33 #include <sys/param.h>
34 #include <sys/kernel.h>
35 #include <sys/malloc.h>
36 #include <sys/queue.h>
37 #include <sys/reboot.h>
38 
39 #include <dev/acpi/acpica.h>
40 #include <dev/acpi/acpireg.h>
41 #include <dev/acpi/acpivar.h>
42 
43 #include <dev/pci/pcireg.h>
44 #include <dev/pci/pcivar.h>
45 
46 #define NUM_ISA_INTERRUPTS	16
47 #define NUM_ACPI_INTERRUPTS	256
48 
49 #define PCI_INVALID_IRQ	255
50 #define PCI_INTERRUPT_VALID(x) ((x) != PCI_INVALID_IRQ && (x) != 0)
51 
52 #define ACPI_SERIAL_BEGIN(x)
53 #define ACPI_SERIAL_END(x)
54 
55 /*
56  * An ACPI PCI link device may contain multiple links.  Each link has its
57  * own ACPI resource.  _PRT entries specify which link is being used via
58  * the Source Index.
59  *
60  * XXX: A note about Source Indices and DPFs:  Currently we assume that
61  * the DPF start and end tags are not counted towards the index that
62  * Source Index corresponds to.  Also, we assume that when DPFs are in use
63  * they various sets overlap in terms of Indices.  Here's an example
64  * resource list indicating these assumptions:
65  *
66  * Resource		Index
67  * --------		-----
68  * I/O Port		0
69  * Start DPF		-
70  * IRQ			1
71  * MemIO		2
72  * Start DPF		-
73  * IRQ			1
74  * MemIO		2
75  * End DPF		-
76  * DMA Channel		3
77  *
78  * The XXX is because I'm not sure if this is a valid assumption to make.
79  */
80 
81 /* States during DPF processing. */
82 #define	DPF_OUTSIDE	0
83 #define	DPF_FIRST	1
84 #define	DPF_IGNORE	2
85 
86 struct link;
87 
88 struct acpi_pci_link_softc {
89 	int	pl_num_links;
90 	int	pl_crs_bad;
91 	struct link *pl_links;
92 	char pl_name[32];
93 	ACPI_HANDLE pl_handle;
94 	TAILQ_ENTRY(acpi_pci_link_softc) pl_list;
95 };
96 
97 static TAILQ_HEAD(, acpi_pci_link_softc) acpi_pci_linkdevs =
98     TAILQ_HEAD_INITIALIZER(acpi_pci_linkdevs);
99 
100 
101 struct link {
102 	struct acpi_pci_link_softc *l_sc;
103 	uint8_t	l_bios_irq;
104 	uint8_t	l_irq;
105 	uint8_t l_trig;
106 	uint8_t l_pol;
107 	uint8_t	l_initial_irq;
108 	int	l_res_index;
109 	int	l_num_irqs;
110 	int	*l_irqs;
111 	int	l_references;
112 	int	l_dev_count;
113 	pcitag_t *l_devices;
114 	int	l_routed:1;
115 	int	l_isa_irq:1;
116 	ACPI_RESOURCE l_prs_template;
117 };
118 
119 struct link_count_request {
120 	int	in_dpf;
121 	int	count;
122 };
123 
124 struct link_res_request {
125 	struct acpi_pci_link_softc *sc;
126 	int	in_dpf;
127 	int	res_index;
128 	int	link_index;
129 };
130 
131 MALLOC_DEFINE(M_PCI_LINK, "pci_link", "ACPI PCI Link structures");
132 
133 static int pci_link_interrupt_weights[NUM_ACPI_INTERRUPTS];
134 static int pci_link_bios_isa_irqs;
135 
136 static ACPI_STATUS acpi_count_irq_resources(ACPI_RESOURCE *, void *);
137 static ACPI_STATUS link_add_crs(ACPI_RESOURCE *, void *);
138 static ACPI_STATUS link_add_prs(ACPI_RESOURCE *, void *);
139 static int link_valid_irq(struct link *, int);
140 static void acpi_pci_link_dump(struct acpi_pci_link_softc *);
141 static int acpi_pci_link_attach(struct acpi_pci_link_softc *);
142 static uint8_t acpi_pci_link_search_irq(struct acpi_pci_link_softc *, int, int,
143 					int);
144 static struct link *acpi_pci_link_lookup(struct acpi_pci_link_softc *, int);
145 static ACPI_STATUS acpi_pci_link_srs(struct acpi_pci_link_softc *,
146 				     ACPI_BUFFER *);
147 static ACPI_STATUS acpi_AppendBufferResource(ACPI_BUFFER *, ACPI_RESOURCE *);
148 
149 static ACPI_STATUS
150 acpi_count_irq_resources(ACPI_RESOURCE *res, void *context)
151 {
152 	struct link_count_request *req;
153 
154 	req = (struct link_count_request *)context;
155 	switch (res->Type) {
156 	case ACPI_RESOURCE_TYPE_START_DEPENDENT:
157 		switch (req->in_dpf) {
158 		case DPF_OUTSIDE:
159 			/* We've started the first DPF. */
160 			req->in_dpf = DPF_FIRST;
161 			break;
162 		case DPF_FIRST:
163 			/* We've started the second DPF. */
164 			req->in_dpf = DPF_IGNORE;
165 			break;
166 		}
167 		break;
168 	case ACPI_RESOURCE_TYPE_END_DEPENDENT:
169 		/* We are finished with DPF parsing. */
170 		KASSERT(req->in_dpf != DPF_OUTSIDE);
171 		req->in_dpf = DPF_OUTSIDE;
172 		break;
173 	case ACPI_RESOURCE_TYPE_IRQ:
174 	case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
175 		/*
176 		 * Don't count resources if we are in a DPF set that we are
177 		 * ignoring.
178 		 */
179 		if (req->in_dpf != DPF_IGNORE)
180 			req->count++;
181 	}
182 	return (AE_OK);
183 }
184 
185 static ACPI_STATUS
186 link_add_crs(ACPI_RESOURCE *res, void *context)
187 {
188 	struct link_res_request *req;
189 	struct link *link;
190 
191 	req = (struct link_res_request *)context;
192 	switch (res->Type) {
193 	case ACPI_RESOURCE_TYPE_START_DEPENDENT:
194 		switch (req->in_dpf) {
195 		case DPF_OUTSIDE:
196 			/* We've started the first DPF. */
197 			req->in_dpf = DPF_FIRST;
198 			break;
199 		case DPF_FIRST:
200 			/* We've started the second DPF. */
201 			panic(
202 		"%s: Multiple dependent functions within a current resource",
203 			    __func__);
204 			break;
205 		}
206 		break;
207 	case ACPI_RESOURCE_TYPE_END_DEPENDENT:
208 		/* We are finished with DPF parsing. */
209 		KASSERT(req->in_dpf != DPF_OUTSIDE);
210 		req->in_dpf = DPF_OUTSIDE;
211 		break;
212 	case ACPI_RESOURCE_TYPE_IRQ:
213 	case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
214 		KASSERT(req->link_index < req->sc->pl_num_links);
215 		link = &req->sc->pl_links[req->link_index];
216 		link->l_res_index = req->res_index;
217 		req->link_index++;
218 		req->res_index++;
219 
220 		/*
221 		 * Only use the current value if there's one IRQ.  Some
222 		 * systems return multiple IRQs (which is nonsense for _CRS)
223 		 * when the link hasn't been programmed.
224 		 */
225 		if (res->Type == ACPI_RESOURCE_TYPE_IRQ) {
226 			if (res->Data.Irq.InterruptCount == 1) {
227 				link->l_irq = res->Data.Irq.Interrupts[0];
228 				link->l_trig = res->Data.Irq.Triggering;
229 				link->l_pol = res->Data.Irq.Polarity;
230 			}
231 		} else if (res->Data.ExtendedIrq.InterruptCount == 1) {
232 			link->l_irq = res->Data.ExtendedIrq.Interrupts[0];
233 			link->l_trig = res->Data.ExtendedIrq.Triggering;
234 			link->l_pol = res->Data.ExtendedIrq.Polarity;
235 		}
236 
237 		/*
238 		 * An IRQ of zero means that the link isn't routed.
239 		 */
240 		if (link->l_irq == 0)
241 			link->l_irq = PCI_INVALID_IRQ;
242 		break;
243 	default:
244 		req->res_index++;
245 	}
246 	return (AE_OK);
247 }
248 
249 /*
250  * Populate the set of possible IRQs for each device.
251  */
252 static ACPI_STATUS
253 link_add_prs(ACPI_RESOURCE *res, void *context)
254 {
255 	struct link_res_request *req;
256 	struct link *link;
257 	UINT8 *irqs = NULL;
258 	UINT32 *ext_irqs = NULL;
259 	int i, is_ext_irq = 1;
260 
261 	req = (struct link_res_request *)context;
262 	switch (res->Type) {
263 	case ACPI_RESOURCE_TYPE_START_DEPENDENT:
264 		switch (req->in_dpf) {
265 		case DPF_OUTSIDE:
266 			/* We've started the first DPF. */
267 			req->in_dpf = DPF_FIRST;
268 			break;
269 		case DPF_FIRST:
270 			/* We've started the second DPF. */
271 			req->in_dpf = DPF_IGNORE;
272 			break;
273 		}
274 		break;
275 	case ACPI_RESOURCE_TYPE_END_DEPENDENT:
276 		/* We are finished with DPF parsing. */
277 		KASSERT(req->in_dpf != DPF_OUTSIDE);
278 		req->in_dpf = DPF_OUTSIDE;
279 		break;
280 	case ACPI_RESOURCE_TYPE_IRQ:
281 		is_ext_irq = 0;
282 		/* fall through */
283 	case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
284 		/*
285 		 * Don't parse resources if we are in a DPF set that we are
286 		 * ignoring.
287 		 */
288 		if (req->in_dpf == DPF_IGNORE)
289 			break;
290 
291 		KASSERT(req->link_index < req->sc->pl_num_links);
292 		link = &req->sc->pl_links[req->link_index];
293 		if (link->l_res_index == -1) {
294 			KASSERT(req->sc->pl_crs_bad);
295 			link->l_res_index = req->res_index;
296 		}
297 		req->link_index++;
298 		req->res_index++;
299 
300 		/*
301 		 * Stash a copy of the resource for later use when
302 		 * doing _SRS.
303 		 *
304 		 * Note that in theory res->Length may exceed the size
305 		 * of ACPI_RESOURCE, due to variable length lists in
306 		 * subtypes.  However, all uses of l_prs_template only
307 		 * rely on lists lengths of zero or one, for which
308 		 * sizeof(ACPI_RESOURCE) is sufficient space anyway.
309 		 * We cannot read longer than Length bytes, in case we
310 		 * read off the end of mapped memory.  So we read
311 		 * whichever length is shortest, Length or
312 		 * sizeof(ACPI_RESOURCE).
313 		 */
314 		KASSERT(res->Length >= ACPI_RS_SIZE_MIN);
315 
316 		memset(&link->l_prs_template, 0, sizeof(link->l_prs_template));
317 		memcpy(&link->l_prs_template, res,
318 		       MIN(res->Length, sizeof(link->l_prs_template)));
319 
320 		if (is_ext_irq) {
321 			link->l_num_irqs =
322 			    res->Data.ExtendedIrq.InterruptCount;
323 			link->l_trig = res->Data.ExtendedIrq.Triggering;
324 			link->l_pol = res->Data.ExtendedIrq.Polarity;
325 			ext_irqs = res->Data.ExtendedIrq.Interrupts;
326 		} else {
327 			link->l_num_irqs = res->Data.Irq.InterruptCount;
328 			link->l_trig = res->Data.Irq.Triggering;
329 			link->l_pol = res->Data.Irq.Polarity;
330 			irqs = res->Data.Irq.Interrupts;
331 		}
332 		if (link->l_num_irqs == 0)
333 			break;
334 
335 		/*
336 		 * Save a list of the valid IRQs.  Also, if all of the
337 		 * valid IRQs are ISA IRQs, then mark this link as
338 		 * routed via an ISA interrupt.
339 		 */
340 		link->l_isa_irq = TRUE;
341 		link->l_irqs = malloc(sizeof(int) * link->l_num_irqs,
342 		    M_PCI_LINK, M_WAITOK | M_ZERO);
343 		for (i = 0; i < link->l_num_irqs; i++) {
344 			if (is_ext_irq) {
345 				link->l_irqs[i] = ext_irqs[i];
346 				if (ext_irqs[i] >= NUM_ISA_INTERRUPTS)
347 					link->l_isa_irq = FALSE;
348 			} else {
349 				link->l_irqs[i] = irqs[i];
350 				if (irqs[i] >= NUM_ISA_INTERRUPTS)
351 					link->l_isa_irq = FALSE;
352 			}
353 		}
354 		break;
355 	default:
356 		if (req->in_dpf == DPF_IGNORE)
357 			break;
358 		if (req->sc->pl_crs_bad)
359 			aprint_normal("%s: Warning: possible resource %d "
360 			       "will be lost during _SRS\n", req->sc->pl_name,
361 			       req->res_index);
362 		req->res_index++;
363 	}
364 	return (AE_OK);
365 }
366 
367 static int
368 link_valid_irq(struct link *link, int irq)
369 {
370 	int i;
371 
372 	/* Invalid interrupts are never valid. */
373 	if (!PCI_INTERRUPT_VALID(irq))
374 		return (FALSE);
375 
376 	/* Any interrupt in the list of possible interrupts is valid. */
377 	for (i = 0; i < link->l_num_irqs; i++)
378 		if (link->l_irqs[i] == irq)
379 			 return (TRUE);
380 
381 	/*
382 	 * For links routed via an ISA interrupt, if the SCI is routed via
383 	 * an ISA interrupt, the SCI is always treated as a valid IRQ.
384 	 */
385 	if (link->l_isa_irq && AcpiGbl_FADT.SciInterrupt == irq &&
386 	    irq < NUM_ISA_INTERRUPTS)
387 		return (TRUE);
388 
389 	/* If the interrupt wasn't found in the list it is not valid. */
390 	return (FALSE);
391 }
392 
393 void
394 acpi_pci_link_state(void)
395 {
396 	struct acpi_pci_link_softc *sc;
397 
398 	TAILQ_FOREACH(sc, &acpi_pci_linkdevs, pl_list) {
399 		acpi_pci_link_dump(sc);
400 	}
401 }
402 
403 static void
404 acpi_pci_link_dump(struct acpi_pci_link_softc *sc)
405 {
406 	struct link *link;
407 	int i, j;
408 
409 	printf("Link Device %s:\n", sc->pl_name);
410 	printf("Index  IRQ  Rtd  Ref  IRQs\n");
411 	for (i = 0; i < sc->pl_num_links; i++) {
412 		link = &sc->pl_links[i];
413 		printf("%5d  %3d   %c   %3d ", i, link->l_irq,
414 		    link->l_routed ? 'Y' : 'N',  link->l_references);
415 		if (link->l_num_irqs == 0)
416 			printf(" none");
417 		else for (j = 0; j < link->l_num_irqs; j++)
418 			printf(" %d", link->l_irqs[j]);
419 		printf(" polarity %u trigger %u\n", link->l_pol, link->l_trig);
420 	}
421 	printf("\n");
422 }
423 
424 static int
425 acpi_pci_link_attach(struct acpi_pci_link_softc *sc)
426 {
427 	struct link_count_request creq;
428 	struct link_res_request rreq;
429 	ACPI_STATUS status;
430 	int i;
431 
432 	ACPI_SERIAL_BEGIN(pci_link);
433 
434 	/*
435 	 * Count the number of current resources so we know how big of
436 	 * a link array to allocate.  On some systems, _CRS is broken,
437 	 * so for those systems try to derive the count from _PRS instead.
438 	 */
439 	creq.in_dpf = DPF_OUTSIDE;
440 	creq.count = 0;
441 	status = AcpiWalkResources(sc->pl_handle, "_CRS",
442 	    acpi_count_irq_resources, &creq);
443 	sc->pl_crs_bad = ACPI_FAILURE(status);
444 	if (sc->pl_crs_bad) {
445 		creq.in_dpf = DPF_OUTSIDE;
446 		creq.count = 0;
447 		status = AcpiWalkResources(sc->pl_handle, "_PRS",
448 		    acpi_count_irq_resources, &creq);
449 		if (ACPI_FAILURE(status)) {
450 			aprint_error("%s: Unable to parse _CRS or _PRS: %s\n",
451 			    sc->pl_name, AcpiFormatException(status));
452 			ACPI_SERIAL_END(pci_link);
453 			return (ENXIO);
454 		}
455 	}
456 	sc->pl_num_links = creq.count;
457 	if (creq.count == 0) {
458 		ACPI_SERIAL_END(pci_link);
459 		return (0);
460 	}
461 	sc->pl_links = malloc(sizeof(struct link) * sc->pl_num_links,
462 	    M_PCI_LINK, M_WAITOK | M_ZERO);
463 
464 	/* Initialize the child links. */
465 	for (i = 0; i < sc->pl_num_links; i++) {
466 		sc->pl_links[i].l_irq = PCI_INVALID_IRQ;
467 		sc->pl_links[i].l_bios_irq = PCI_INVALID_IRQ;
468 		sc->pl_links[i].l_sc = sc;
469 		sc->pl_links[i].l_isa_irq = FALSE;
470 		sc->pl_links[i].l_res_index = -1;
471 		sc->pl_links[i].l_dev_count = 0;
472 		sc->pl_links[i].l_devices = NULL;
473 	}
474 
475 	/* Try to read the current settings from _CRS if it is valid. */
476 	if (!sc->pl_crs_bad) {
477 		rreq.in_dpf = DPF_OUTSIDE;
478 		rreq.link_index = 0;
479 		rreq.res_index = 0;
480 		rreq.sc = sc;
481 		status = AcpiWalkResources(sc->pl_handle, "_CRS",
482 		    link_add_crs, &rreq);
483 		if (ACPI_FAILURE(status)) {
484 			aprint_error("%s: Unable to parse _CRS: %s\n",
485 			    sc->pl_name, AcpiFormatException(status));
486 			goto fail;
487 		}
488 	}
489 
490 	/*
491 	 * Try to read the possible settings from _PRS.  Note that if the
492 	 * _CRS is toast, we depend on having a working _PRS.  However, if
493 	 * _CRS works, then it is ok for _PRS to be missing.
494 	 */
495 	rreq.in_dpf = DPF_OUTSIDE;
496 	rreq.link_index = 0;
497 	rreq.res_index = 0;
498 	rreq.sc = sc;
499 	status = AcpiWalkResources(sc->pl_handle, "_PRS",
500 	    link_add_prs, &rreq);
501 	if (ACPI_FAILURE(status) &&
502 	    (status != AE_NOT_FOUND || sc->pl_crs_bad)) {
503 		aprint_error("%s: Unable to parse _PRS: %s\n",
504 		    sc->pl_name, AcpiFormatException(status));
505 		goto fail;
506 	}
507 	if (boothowto & AB_VERBOSE) {
508 		aprint_normal("%s: Links after initial probe:\n", sc->pl_name);
509 		acpi_pci_link_dump(sc);
510 	}
511 
512 	/* Verify initial IRQs if we have _PRS. */
513 	if (status != AE_NOT_FOUND)
514 		for (i = 0; i < sc->pl_num_links; i++)
515 			if (!link_valid_irq(&sc->pl_links[i],
516 			    sc->pl_links[i].l_irq))
517 				sc->pl_links[i].l_irq = PCI_INVALID_IRQ;
518 	if (boothowto & AB_VERBOSE) {
519 		printf("%s: Links after initial validation:\n", sc->pl_name);
520 		acpi_pci_link_dump(sc);
521 	}
522 
523 	/* Save initial IRQs. */
524 	for (i = 0; i < sc->pl_num_links; i++)
525 		sc->pl_links[i].l_initial_irq = sc->pl_links[i].l_irq;
526 
527 	/*
528 	 * Try to disable this link.  If successful, set the current IRQ to
529 	 * zero and flags to indicate this link is not routed.  If we can't
530 	 * run _DIS (i.e., the method doesn't exist), assume the initial
531 	 * IRQ was routed by the BIOS.
532 	 */
533 #if 0	/* XXX causes spontaneaous resets on some systems. Disabled for now. */
534 	if (ACPI_SUCCESS(AcpiEvaluateObject(sc->pl_handle, "_DIS", NULL,
535 	    NULL)))
536 		for (i = 0; i < sc->pl_num_links; i++)
537 			sc->pl_links[i].l_irq = PCI_INVALID_IRQ;
538 	else
539 #endif
540 		for (i = 0; i < sc->pl_num_links; i++)
541 			if (PCI_INTERRUPT_VALID(sc->pl_links[i].l_irq))
542 				sc->pl_links[i].l_routed = TRUE;
543 	if (boothowto & AB_VERBOSE) {
544 		printf("%s: Links after disable:\n", sc->pl_name);
545 		acpi_pci_link_dump(sc);
546 	}
547 	ACPI_SERIAL_END(pci_link);
548 	return (0);
549 fail:
550 	ACPI_SERIAL_END(pci_link);
551 	for (i = 0; i < sc->pl_num_links; i++) {
552 		if (sc->pl_links[i].l_irqs != NULL)
553 			free(sc->pl_links[i].l_irqs, M_PCI_LINK);
554 		if (sc->pl_links[i].l_devices != NULL)
555 			free(sc->pl_links[i].l_devices, M_PCI_LINK);
556 	}
557 	free(sc->pl_links, M_PCI_LINK);
558 	return (ENXIO);
559 }
560 
561 static void
562 acpi_pci_link_add_functions(struct acpi_pci_link_softc *sc, struct link *link,
563     int bus, int device, int pin)
564 {
565 	uint32_t value;
566 	uint8_t func, maxfunc, ipin;
567 	pcitag_t tag;
568 
569 	tag = pci_make_tag(acpi_softc->sc_pc, bus, device, 0);
570 	/* See if we have a valid device at function 0. */
571 	value = pci_conf_read(acpi_softc->sc_pc, tag,  PCI_BHLC_REG);
572 	if (PCI_HDRTYPE_TYPE(value) > PCI_HDRTYPE_PCB)
573 		return;
574 	if (PCI_HDRTYPE_MULTIFN(value))
575 		maxfunc = 7;
576 	else
577 		maxfunc = 0;
578 
579 	/* Scan all possible functions at this device. */
580 	for (func = 0; func <= maxfunc; func++) {
581 		tag = pci_make_tag(acpi_softc->sc_pc, bus, device, func);
582 		value = pci_conf_read(acpi_softc->sc_pc, tag, PCI_ID_REG);
583 		if (PCI_VENDOR(value) == 0xffff)
584 			continue;
585 		value = pci_conf_read(acpi_softc->sc_pc, tag,
586 		    PCI_INTERRUPT_REG);
587 		ipin = PCI_INTERRUPT_PIN(value);
588 		/*
589 		 * See if it uses the pin in question.  Note that the passed
590 		 * in pin uses 0 for A, .. 3 for D whereas the intpin
591 		 * register uses 0 for no interrupt, 1 for A, .. 4 for D.
592 		 */
593 		if (ipin != pin + 1)
594 			continue;
595 
596 		link->l_devices = realloc(link->l_devices,
597 		    sizeof(pcitag_t) * (link->l_dev_count + 1),
598 		    M_PCI_LINK, M_WAITOK);
599 		link->l_devices[link->l_dev_count] = tag;
600 		++link->l_dev_count;
601 	}
602 }
603 
604 static uint8_t
605 acpi_pci_link_search_irq(struct acpi_pci_link_softc *sc, int bus, int device,
606 			 int pin)
607 {
608 	uint32_t value;
609 	uint8_t func, maxfunc, ipin, iline;
610 	pcitag_t tag;
611 
612 	tag = pci_make_tag(acpi_softc->sc_pc, bus, device, 0);
613 	/* See if we have a valid device at function 0. */
614 	value = pci_conf_read(acpi_softc->sc_pc, tag,  PCI_BHLC_REG);
615 	if (PCI_HDRTYPE_TYPE(value) > PCI_HDRTYPE_PCB)
616 		return (PCI_INVALID_IRQ);
617 	if (PCI_HDRTYPE_MULTIFN(value))
618 		maxfunc = 7;
619 	else
620 		maxfunc = 0;
621 
622 	/* Scan all possible functions at this device. */
623 	for (func = 0; func <= maxfunc; func++) {
624 		tag = pci_make_tag(acpi_softc->sc_pc, bus, device, func);
625 		value = pci_conf_read(acpi_softc->sc_pc, tag, PCI_ID_REG);
626 		if (PCI_VENDOR(value) == 0xffff)
627 			continue;
628 		value = pci_conf_read(acpi_softc->sc_pc, tag,
629 		    PCI_INTERRUPT_REG);
630 		ipin = PCI_INTERRUPT_PIN(value);
631 		iline = PCI_INTERRUPT_LINE(value);
632 
633 		/*
634 		 * See if it uses the pin in question.  Note that the passed
635 		 * in pin uses 0 for A, .. 3 for D whereas the intpin
636 		 * register uses 0 for no interrupt, 1 for A, .. 4 for D.
637 		 */
638 		if (ipin != pin + 1)
639 			continue;
640 		aprint_verbose(
641 		    "%s: ACPI: Found matching pin for %d.%d.INT%c"
642 	            " at func %d: %d\n",
643 			    sc->pl_name, bus, device, pin + 'A', func, iline);
644 		if (PCI_INTERRUPT_VALID(iline))
645 			return (iline);
646 	}
647 	return (PCI_INVALID_IRQ);
648 }
649 
650 /*
651  * Find the link structure that corresponds to the resource index passed in
652  * via 'source_index'.
653  */
654 static struct link *
655 acpi_pci_link_lookup(struct acpi_pci_link_softc *sc, int source_index)
656 {
657 	int i;
658 
659 	for (i = 0; i < sc->pl_num_links; i++)
660 		if (sc->pl_links[i].l_res_index == source_index)
661 			return (&sc->pl_links[i]);
662 	return (NULL);
663 }
664 
665 void
666 acpi_pci_link_add_reference(void *v, int index, int bus, int slot, int pin)
667 {
668 	struct acpi_pci_link_softc *sc = v;
669 	struct link *link;
670 	uint8_t bios_irq;
671 
672 	/* Bump the reference count. */
673 	ACPI_SERIAL_BEGIN(pci_link);
674 	link = acpi_pci_link_lookup(sc, index);
675 	if (link == NULL) {
676 		printf("%s: apparently invalid index %d\n", sc->pl_name, index);
677 		ACPI_SERIAL_END(pci_link);
678 		return;
679 	}
680 	link->l_references++;
681 	acpi_pci_link_add_functions(sc, link, bus, slot, pin);
682 	if (link->l_routed)
683 		pci_link_interrupt_weights[link->l_irq]++;
684 
685 	/*
686 	 * The BIOS only routes interrupts via ISA IRQs using the ATPICs
687 	 * (8259As).  Thus, if this link is routed via an ISA IRQ, go
688 	 * look to see if the BIOS routed an IRQ for this link at the
689 	 * indicated (bus, slot, pin).  If so, we prefer that IRQ for
690 	 * this link and add that IRQ to our list of known-good IRQs.
691 	 * This provides a good work-around for link devices whose _CRS
692 	 * method is either broken or bogus.  We only use the value
693 	 * returned by _CRS if we can't find a valid IRQ via this method
694 	 * in fact.
695 	 *
696 	 * If this link is not routed via an ISA IRQ (because we are using
697 	 * APIC for example), then don't bother looking up the BIOS IRQ
698 	 * as if we find one it won't be valid anyway.
699 	 */
700 	if (!link->l_isa_irq) {
701 		ACPI_SERIAL_END(pci_link);
702 		return;
703 	}
704 
705 	/* Try to find a BIOS IRQ setting from any matching devices. */
706 	bios_irq = acpi_pci_link_search_irq(sc, bus, slot, pin);
707 	if (!PCI_INTERRUPT_VALID(bios_irq)) {
708 		ACPI_SERIAL_END(pci_link);
709 		return;
710 	}
711 
712 	/* Validate the BIOS IRQ. */
713 	if (!link_valid_irq(link, bios_irq)) {
714 		printf("%s: BIOS IRQ %u for %d.%d.INT%c is invalid\n",
715 		    sc->pl_name, bios_irq, (int)bus, slot, pin + 'A');
716 	} else if (!PCI_INTERRUPT_VALID(link->l_bios_irq)) {
717 		link->l_bios_irq = bios_irq;
718 		if (bios_irq < NUM_ISA_INTERRUPTS)
719 			pci_link_bios_isa_irqs |= (1 << bios_irq);
720 		if (bios_irq != link->l_initial_irq &&
721 		    PCI_INTERRUPT_VALID(link->l_initial_irq))
722 			printf(
723 			    "%s: BIOS IRQ %u does not match initial IRQ %u\n",
724 			    sc->pl_name, bios_irq, link->l_initial_irq);
725 	} else if (bios_irq != link->l_bios_irq)
726 		printf(
727 	    "%s: BIOS IRQ %u for %d.%d.INT%c does not match "
728 	    "previous BIOS IRQ %u\n",
729 		    sc->pl_name, bios_irq, (int)bus, slot, pin + 'A',
730 		    link->l_bios_irq);
731 	ACPI_SERIAL_END(pci_link);
732 }
733 
734 static ACPI_STATUS
735 acpi_pci_link_srs_from_crs(struct acpi_pci_link_softc *sc, ACPI_BUFFER *srsbuf)
736 {
737 	ACPI_RESOURCE *resource, *end, newres, *resptr;
738 	ACPI_BUFFER crsbuf;
739 	ACPI_STATUS status;
740 	struct link *link;
741 	int i, in_dpf;
742 
743 	/* Fetch the _CRS. */
744 	crsbuf.Pointer = NULL;
745 	crsbuf.Length = ACPI_ALLOCATE_BUFFER;
746 	status = AcpiGetCurrentResources(sc->pl_handle, &crsbuf);
747 	if (ACPI_SUCCESS(status) && crsbuf.Pointer == NULL)
748 		status = AE_NO_MEMORY;
749 	if (ACPI_FAILURE(status)) {
750 		aprint_verbose("%s: Unable to fetch current resources: %s\n",
751 		    sc->pl_name, AcpiFormatException(status));
752 		return (status);
753 	}
754 
755 	/* Fill in IRQ resources via link structures. */
756 	srsbuf->Pointer = NULL;
757 	link = sc->pl_links;
758 	i = 0;
759 	in_dpf = DPF_OUTSIDE;
760 	resource = (ACPI_RESOURCE *)crsbuf.Pointer;
761 	end = (ACPI_RESOURCE *)((char *)crsbuf.Pointer + crsbuf.Length);
762 	for (;;) {
763 		switch (resource->Type) {
764 		case ACPI_RESOURCE_TYPE_START_DEPENDENT:
765 			switch (in_dpf) {
766 			case DPF_OUTSIDE:
767 				/* We've started the first DPF. */
768 				in_dpf = DPF_FIRST;
769 				break;
770 			case DPF_FIRST:
771 				/* We've started the second DPF. */
772 				panic(
773 		"%s: Multiple dependent functions within a current resource",
774 				    __func__);
775 				break;
776 			}
777 			resptr = NULL;
778 			break;
779 		case ACPI_RESOURCE_TYPE_END_DEPENDENT:
780 			/* We are finished with DPF parsing. */
781 			KASSERT(in_dpf != DPF_OUTSIDE);
782 			in_dpf = DPF_OUTSIDE;
783 			resptr = NULL;
784 			break;
785 		case ACPI_RESOURCE_TYPE_IRQ:
786 			newres = link->l_prs_template;
787 			resptr = &newres;
788 			resptr->Data.Irq.InterruptCount = 1;
789 			if (PCI_INTERRUPT_VALID(link->l_irq)) {
790 				KASSERT(link->l_irq < NUM_ISA_INTERRUPTS);
791 				resptr->Data.Irq.Interrupts[0] = link->l_irq;
792 				resptr->Data.Irq.Triggering = link->l_trig;
793 				resptr->Data.Irq.Polarity = link->l_pol;
794 			} else
795 				resptr->Data.Irq.Interrupts[0] = 0;
796 			link++;
797 			i++;
798 			break;
799 		case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
800 			newres = link->l_prs_template;
801 			resptr = &newres;
802 			resptr->Data.ExtendedIrq.InterruptCount = 1;
803 			if (PCI_INTERRUPT_VALID(link->l_irq)) {
804 				resptr->Data.ExtendedIrq.Interrupts[0] =
805 				    link->l_irq;
806 				resptr->Data.ExtendedIrq.Triggering =
807 				    link->l_trig;
808 				resptr->Data.ExtendedIrq.Polarity = link->l_pol;
809 			} else
810 				resptr->Data.ExtendedIrq.Interrupts[0] = 0;
811 			link++;
812 			i++;
813 			break;
814 		default:
815 			resptr = resource;
816 		}
817 		if (resptr != NULL) {
818 			status = acpi_AppendBufferResource(srsbuf, resptr);
819 			if (ACPI_FAILURE(status)) {
820 				printf("%s: Unable to build resources: %s\n",
821 				    sc->pl_name, AcpiFormatException(status));
822 				if (srsbuf->Pointer != NULL)
823 					AcpiOsFree(srsbuf->Pointer);
824 				AcpiOsFree(crsbuf.Pointer);
825 				return (status);
826 			}
827 		}
828 		if (resource->Type == ACPI_RESOURCE_TYPE_END_TAG)
829 			break;
830 		resource = ACPI_NEXT_RESOURCE(resource);
831 		if (resource >= end)
832 			break;
833 	}
834 	AcpiOsFree(crsbuf.Pointer);
835 	return (AE_OK);
836 }
837 
838 static ACPI_STATUS
839 acpi_pci_link_srs_from_links(struct acpi_pci_link_softc *sc,
840     ACPI_BUFFER *srsbuf)
841 {
842 	ACPI_RESOURCE newres;
843 	ACPI_STATUS status;
844 	struct link *link;
845 	int i;
846 
847 	/* Start off with an empty buffer. */
848 	srsbuf->Pointer = NULL;
849 	link = sc->pl_links;
850 	for (i = 0; i < sc->pl_num_links; i++) {
851 
852 		/* Add a new IRQ resource from each link. */
853 		link = &sc->pl_links[i];
854 		newres = link->l_prs_template;
855 		if (newres.Type == ACPI_RESOURCE_TYPE_IRQ) {
856 
857 			/* Build an IRQ resource. */
858 			newres.Data.Irq.InterruptCount = 1;
859 			if (PCI_INTERRUPT_VALID(link->l_irq)) {
860 				KASSERT(link->l_irq < NUM_ISA_INTERRUPTS);
861 				newres.Data.Irq.Interrupts[0] = link->l_irq;
862 				newres.Data.Irq.Triggering = link->l_trig;
863 				newres.Data.Irq.Polarity = link->l_pol;
864 			} else
865 				newres.Data.Irq.Interrupts[0] = 0;
866 		} else {
867 
868 			/* Build an ExtIRQ resuorce. */
869 			newres.Data.ExtendedIrq.InterruptCount = 1;
870 			if (PCI_INTERRUPT_VALID(link->l_irq)) {
871 				newres.Data.ExtendedIrq.Interrupts[0] =
872 				    link->l_irq;
873 				newres.Data.ExtendedIrq.Triggering =
874 				    link->l_trig;
875 				newres.Data.ExtendedIrq.Polarity =
876 				    link->l_pol;
877 			} else {
878 				newres.Data.ExtendedIrq.Interrupts[0] = 0;
879 			}
880 		}
881 
882 		/* Add the new resource to the end of the _SRS buffer. */
883 		status = acpi_AppendBufferResource(srsbuf, &newres);
884 		if (ACPI_FAILURE(status)) {
885 			printf("%s: Unable to build resources: %s\n",
886 			    sc->pl_name, AcpiFormatException(status));
887 			if (srsbuf->Pointer != NULL)
888 				AcpiOsFree(srsbuf->Pointer);
889 			return (status);
890 		}
891 	}
892 	return (AE_OK);
893 }
894 
895 static ACPI_STATUS
896 acpi_pci_link_srs(struct acpi_pci_link_softc *sc, ACPI_BUFFER *srsbuf)
897 {
898 	ACPI_STATUS status;
899 
900 	if (sc->pl_crs_bad)
901 		status = acpi_pci_link_srs_from_links(sc, srsbuf);
902 	else
903 		status = acpi_pci_link_srs_from_crs(sc, srsbuf);
904 
905 	/* Write out new resources via _SRS. */
906 	return AcpiSetCurrentResources(sc->pl_handle, srsbuf);
907 }
908 
909 static ACPI_STATUS
910 acpi_pci_link_route_irqs(struct acpi_pci_link_softc *sc, int *irq, int *pol,
911 			 int *trig)
912 {
913 	ACPI_RESOURCE *resource, *end;
914 	ACPI_BUFFER srsbuf;
915 	ACPI_STATUS status;
916 	struct link *link;
917 	int i, is_ext = 0;
918 
919 	status = acpi_pci_link_srs(sc, &srsbuf);
920 	if (ACPI_FAILURE(status)) {
921 		printf("%s: _SRS failed: %s\n",
922 		    sc->pl_name, AcpiFormatException(status));
923 		return (status);
924 	}
925 	/*
926 	 * Perform acpi_config_intr() on each IRQ resource if it was just
927 	 * routed for the first time.
928 	 */
929 	link = sc->pl_links;
930 	i = 0;
931 	resource = (ACPI_RESOURCE *)srsbuf.Pointer;
932 	end = (ACPI_RESOURCE *)((char *)srsbuf.Pointer + srsbuf.Length);
933 	for (;;) {
934 		if (resource->Type == ACPI_RESOURCE_TYPE_END_TAG)
935 			break;
936 		switch (resource->Type) {
937 		case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
938 			is_ext = 1;
939 			/* FALLTHROUGH */
940 		case ACPI_RESOURCE_TYPE_IRQ:
941 			/*
942 			 * Only configure the interrupt and update the
943 			 * weights if this link has a valid IRQ and was
944 			 * previously unrouted.
945 			 */
946 			if (!link->l_routed &&
947 			    PCI_INTERRUPT_VALID(link->l_irq)) {
948 				*trig = is_ext ?
949 				    resource->Data.ExtendedIrq.Triggering :
950 				    resource->Data.Irq.Triggering;
951 				*pol = is_ext ?
952 				    resource->Data.ExtendedIrq.Polarity :
953 				    resource->Data.Irq.Polarity;
954 				*irq = is_ext ?
955 				    resource->Data.ExtendedIrq.Interrupts[0] :
956 				    resource->Data.Irq.Interrupts[0];
957 				link->l_routed = TRUE;
958 				pci_link_interrupt_weights[link->l_irq] +=
959 				    link->l_references;
960 			}
961 			link++;
962 			i++;
963 			break;
964 		}
965 		resource = ACPI_NEXT_RESOURCE(resource);
966 		if (resource >= end)
967 			break;
968 	}
969 	AcpiOsFree(srsbuf.Pointer);
970 	return (AE_OK);
971 }
972 
973 /*
974  * Pick an IRQ to use for this unrouted link.
975  */
976 static uint8_t
977 acpi_pci_link_choose_irq(struct acpi_pci_link_softc *sc, struct link *link)
978 {
979 	u_int8_t best_irq, pos_irq;
980 	int best_weight, pos_weight, i;
981 
982 	KASSERT(!link->l_routed);
983 	KASSERT(!PCI_INTERRUPT_VALID(link->l_irq));
984 
985 	/*
986 	 * If we have a valid BIOS IRQ, use that.  We trust what the BIOS
987 	 * says it routed over what _CRS says the link thinks is routed.
988 	 */
989 	if (PCI_INTERRUPT_VALID(link->l_bios_irq))
990 		return (link->l_bios_irq);
991 
992 	/*
993 	 * If we don't have a BIOS IRQ but do have a valid IRQ from _CRS,
994 	 * then use that.
995 	 */
996 	if (PCI_INTERRUPT_VALID(link->l_initial_irq))
997 		return (link->l_initial_irq);
998 
999 	/*
1000 	 * Ok, we have no useful hints, so we have to pick from the
1001 	 * possible IRQs.  For ISA IRQs we only use interrupts that
1002 	 * have already been used by the BIOS.
1003 	 */
1004 	best_irq = PCI_INVALID_IRQ;
1005 	best_weight = INT_MAX;
1006 	for (i = 0; i < link->l_num_irqs; i++) {
1007 		pos_irq = link->l_irqs[i];
1008 		if (pos_irq < NUM_ISA_INTERRUPTS &&
1009 		    (pci_link_bios_isa_irqs & 1 << pos_irq) == 0)
1010 			continue;
1011 		pos_weight = pci_link_interrupt_weights[pos_irq];
1012 		if (pos_weight < best_weight) {
1013 			best_weight = pos_weight;
1014 			best_irq = pos_irq;
1015 		}
1016 	}
1017 
1018 	/*
1019 	 * If this is an ISA IRQ, try using the SCI if it is also an ISA
1020 	 * interrupt as a fallback.
1021 	 */
1022 	if (link->l_isa_irq && !PCI_INTERRUPT_VALID(best_irq)) {
1023 		pos_irq = AcpiGbl_FADT.SciInterrupt;
1024 		pos_weight = pci_link_interrupt_weights[pos_irq];
1025 		if (pos_weight < best_weight) {
1026 			best_weight = pos_weight;
1027 			best_irq = pos_irq;
1028 		}
1029 	}
1030 
1031 	if (PCI_INTERRUPT_VALID(best_irq)) {
1032 		aprint_verbose("%s: Picked IRQ %u with weight %d\n",
1033 		    sc->pl_name, best_irq, best_weight);
1034 	} else
1035 		printf("%s: Unable to choose an IRQ\n", sc->pl_name);
1036 	return (best_irq);
1037 }
1038 
1039 int
1040 acpi_pci_link_route_interrupt(void *v, int index, int *irq, int *pol, int *trig)
1041 {
1042 	struct acpi_pci_link_softc *sc = v;
1043 	struct link *link;
1044 	int i;
1045 	pcireg_t reg;
1046 
1047 	ACPI_SERIAL_BEGIN(pci_link);
1048 	link = acpi_pci_link_lookup(sc, index);
1049 	if (link == NULL)
1050 		panic("%s: apparently invalid index %d", __func__, index);
1051 
1052 	/*
1053 	 * If this link device is already routed to an interrupt, just return
1054 	 * the interrupt it is routed to.
1055 	 */
1056 	if (link->l_routed) {
1057 		KASSERT(PCI_INTERRUPT_VALID(link->l_irq));
1058 		ACPI_SERIAL_END(pci_link);
1059 		*irq = link->l_irq;
1060 		*pol = link->l_pol;
1061 		*trig = link->l_trig;
1062 		return (link->l_irq);
1063 	}
1064 
1065 	/* Choose an IRQ if we need one. */
1066 	if (PCI_INTERRUPT_VALID(link->l_irq)) {
1067 		*irq = link->l_irq;
1068 		*pol = link->l_pol;
1069 		*trig = link->l_trig;
1070 		goto done;
1071 	}
1072 
1073 	link->l_irq = acpi_pci_link_choose_irq(sc, link);
1074 
1075 	/*
1076 	 * Try to route the interrupt we picked.  If it fails, then
1077 	 * assume the interrupt is not routed.
1078 	 */
1079 	if (!PCI_INTERRUPT_VALID(link->l_irq))
1080 		goto done;
1081 
1082 	acpi_pci_link_route_irqs(sc, irq, pol, trig);
1083 	if (!link->l_routed) {
1084 		link->l_irq = PCI_INVALID_IRQ;
1085 		goto done;
1086 	}
1087 
1088 	link->l_pol = *pol;
1089 	link->l_trig = *trig;
1090 	for (i = 0; i < link->l_dev_count; ++i) {
1091 		reg = pci_conf_read(acpi_softc->sc_pc, link->l_devices[i],
1092 		    PCI_INTERRUPT_REG);
1093 		reg &= ~(PCI_INTERRUPT_LINE_MASK << PCI_INTERRUPT_LINE_SHIFT);
1094 		reg |= link->l_irq << PCI_INTERRUPT_LINE_SHIFT;
1095 		pci_conf_write(acpi_softc->sc_pc, link->l_devices[i],
1096 		    PCI_INTERRUPT_REG, reg);
1097 	}
1098 
1099 done:
1100 	ACPI_SERIAL_END(pci_link);
1101 
1102 	return (link->l_irq);
1103 }
1104 
1105 /*
1106  * This is gross, but we abuse the identify routine to perform one-time
1107  * SYSINIT() style initialization for the driver.
1108  */
1109 static void
1110 acpi_pci_link_init(struct acpi_pci_link_softc *sc)
1111 {
1112 	ACPI_BUFFER buf;
1113 
1114 	/*
1115 	 * If the SCI is an ISA IRQ, add it to the bitmask of known good
1116 	 * ISA IRQs.
1117 	 *
1118 	 * XXX: If we are using the APIC, the SCI might have been
1119 	 * rerouted to an APIC pin in which case this is invalid.  However,
1120 	 * if we are using the APIC, we also shouldn't be having any PCI
1121 	 * interrupts routed via ISA IRQs, so this is probably ok.
1122 	 */
1123 	if (AcpiGbl_FADT.SciInterrupt < NUM_ISA_INTERRUPTS)
1124 		pci_link_bios_isa_irqs |= (1 << AcpiGbl_FADT.SciInterrupt);
1125 
1126 	buf.Length = sizeof (sc->pl_name);
1127 	buf.Pointer = sc->pl_name;
1128 
1129 	if (ACPI_FAILURE(AcpiGetName(sc->pl_handle, ACPI_SINGLE_NAME, &buf)))
1130 		snprintf(sc->pl_name, sizeof (sc->pl_name), "%s",
1131 		    "ACPI link device");
1132 
1133 	acpi_pci_link_attach(sc);
1134 }
1135 
1136 void *
1137 acpi_pci_link_devbyhandle(ACPI_HANDLE handle)
1138 {
1139 	struct acpi_pci_link_softc *sc;
1140 
1141 	TAILQ_FOREACH(sc, &acpi_pci_linkdevs, pl_list) {
1142 		if (sc->pl_handle == handle)
1143 			return sc;
1144 	}
1145 
1146 	sc = malloc(sizeof (*sc), M_PCI_LINK, M_NOWAIT|M_ZERO);
1147 	if (sc == NULL)
1148 		return NULL;
1149 
1150 	sc->pl_handle = handle;
1151 
1152 	acpi_pci_link_init(sc);
1153 
1154 	TAILQ_INSERT_TAIL(&acpi_pci_linkdevs, sc, pl_list);
1155 
1156 	return (void *)sc;
1157 }
1158 
1159 void
1160 acpi_pci_link_resume(void)
1161 {
1162 	struct acpi_pci_link_softc *sc;
1163 	ACPI_BUFFER srsbuf;
1164 
1165 	TAILQ_FOREACH(sc, &acpi_pci_linkdevs, pl_list) {
1166 		ACPI_SERIAL_BEGIN(pci_link);
1167 		if (ACPI_SUCCESS(acpi_pci_link_srs(sc, &srsbuf)))
1168 			AcpiOsFree(srsbuf.Pointer);
1169 		ACPI_SERIAL_END(pci_link);
1170 	}
1171 }
1172 
1173 ACPI_HANDLE
1174 acpi_pci_link_handle(void *v)
1175 {
1176 	struct acpi_pci_link_softc *sc = v;
1177 
1178 	return sc->pl_handle;
1179 }
1180 
1181 char *
1182 acpi_pci_link_name(void *v)
1183 {
1184 	struct acpi_pci_link_softc *sc = v;
1185 
1186 	return sc->pl_name;
1187 }
1188 
1189 
1190 /*
1191  * Append an ACPI_RESOURCE to an ACPI_BUFFER.
1192  *
1193  * Given a pointer to an ACPI_RESOURCE structure, expand the ACPI_BUFFER
1194  * provided to contain it.  If the ACPI_BUFFER is empty, allocate a sensible
1195  * backing block.  If the ACPI_RESOURCE is NULL, return an empty set of
1196  * resources.
1197  */
1198 #define ACPI_INITIAL_RESOURCE_BUFFER_SIZE	512
1199 
1200 static ACPI_STATUS
1201 acpi_AppendBufferResource(ACPI_BUFFER *buf, ACPI_RESOURCE *res)
1202 {
1203 	ACPI_RESOURCE	*rp;
1204 	void		*newp;
1205 
1206 	/* Initialise the buffer if necessary. */
1207 	if (buf->Pointer == NULL) {
1208 	buf->Length = ACPI_INITIAL_RESOURCE_BUFFER_SIZE;
1209 	if ((buf->Pointer = AcpiOsAllocate(buf->Length)) == NULL)
1210 		return (AE_NO_MEMORY);
1211 	rp = (ACPI_RESOURCE *)buf->Pointer;
1212 	rp->Type =  ACPI_RESOURCE_TYPE_END_TAG;
1213 	rp->Length = 0;
1214 	}
1215 
1216 	if (res == NULL)
1217 		return (AE_OK);
1218 
1219 	/*
1220 	 * Scan the current buffer looking for the terminator.
1221 	 * This will either find the terminator or hit the end
1222 	 * of the buffer and return an error.
1223 	 */
1224 	rp = (ACPI_RESOURCE *)buf->Pointer;
1225 	for (;;) {
1226 		/* Range check, don't go outside the buffer */
1227 		if (rp >= (ACPI_RESOURCE *)((u_int8_t *)buf->Pointer +
1228 		    buf->Length))
1229 			return (AE_BAD_PARAMETER);
1230 		if (rp->Type ==  ACPI_RESOURCE_TYPE_END_TAG || rp->Length == 0)
1231 			break;
1232 		rp = ACPI_NEXT_RESOURCE(rp);
1233 	}
1234 
1235 	/*
1236 	 * Check the size of the buffer and expand if required.
1237 	 *
1238 	 * Required size is:
1239 	 *	size of existing resources before terminator +
1240 	 *	size of new resource and header +
1241 	 * 	size of terminator.
1242 	 *
1243 	 * Note that this loop should really only run once, unless
1244 	 * for some reason we are stuffing a *really* huge resource.
1245 	 */
1246 	while ((((u_int8_t *)rp - (u_int8_t *)buf->Pointer) +
1247 	    res->Length + ACPI_RS_SIZE_NO_DATA +
1248 	    ACPI_RS_SIZE_MIN) >= buf->Length) {
1249 		if ((newp = AcpiOsAllocate(buf->Length * 2)) == NULL)
1250 			return (AE_NO_MEMORY);
1251 		memcpy(newp, buf->Pointer, buf->Length);
1252 		rp = (ACPI_RESOURCE *)((u_int8_t *)newp +
1253 		   ((u_int8_t *)rp - (u_int8_t *)buf->Pointer));
1254 		AcpiOsFree(buf->Pointer);
1255 		buf->Pointer = newp;
1256 		buf->Length += buf->Length;
1257 	}
1258 
1259 	/* Insert the new resource. */
1260 	memcpy(rp, res, res->Length + ACPI_RS_SIZE_NO_DATA);
1261 
1262 	/* And add the terminator. */
1263 	rp = ACPI_NEXT_RESOURCE(rp);
1264 	rp->Type =  ACPI_RESOURCE_TYPE_END_TAG;
1265 	rp->Length = 0;
1266 
1267 	return (AE_OK);
1268 }
1269