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acpi_pci_link.c revision 1.6
      1 /*	$NetBSD: acpi_pci_link.c,v 1.6 2006/09/24 03:53:08 jmcneill Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2002 Mitsuru IWASAKI <iwasaki (at) 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 1.6 2006/09/24 03:53:08 jmcneill 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 	void *pl_powerhook;
     95 	TAILQ_ENTRY(acpi_pci_link_softc) pl_list;
     96 };
     97 
     98 static TAILQ_HEAD(, acpi_pci_link_softc) acpi_pci_linkdevs =
     99     TAILQ_HEAD_INITIALIZER(acpi_pci_linkdevs);
    100 
    101 
    102 struct link {
    103 	struct acpi_pci_link_softc *l_sc;
    104 	uint8_t	l_bios_irq;
    105 	uint8_t	l_irq;
    106 	uint8_t l_trig;
    107 	uint8_t l_pol;
    108 	uint8_t	l_initial_irq;
    109 	int	l_res_index;
    110 	int	l_num_irqs;
    111 	int	*l_irqs;
    112 	int	l_references;
    113 	int	l_routed:1;
    114 	int	l_isa_irq:1;
    115 	ACPI_RESOURCE l_prs_template;
    116 };
    117 
    118 struct link_count_request {
    119 	int	in_dpf;
    120 	int	count;
    121 };
    122 
    123 struct link_res_request {
    124 	struct acpi_pci_link_softc *sc;
    125 	int	in_dpf;
    126 	int	res_index;
    127 	int	link_index;
    128 };
    129 
    130 MALLOC_DEFINE(M_PCI_LINK, "pci_link", "ACPI PCI Link structures");
    131 
    132 static int pci_link_interrupt_weights[NUM_ACPI_INTERRUPTS];
    133 static int pci_link_bios_isa_irqs;
    134 
    135 static ACPI_STATUS acpi_count_irq_resources(ACPI_RESOURCE *, void *);
    136 static ACPI_STATUS link_add_crs(ACPI_RESOURCE *, void *);
    137 static ACPI_STATUS link_add_prs(ACPI_RESOURCE *, void *);
    138 static int link_valid_irq(struct link *, int);
    139 static void acpi_pci_link_dump(struct acpi_pci_link_softc *);
    140 static int acpi_pci_link_attach(struct acpi_pci_link_softc *);
    141 static uint8_t acpi_pci_link_search_irq(struct acpi_pci_link_softc *, int, int,
    142 					int);
    143 static void acpi_pci_link_resume(int, void *);
    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->SciInt == 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 	}
    472 
    473 	/* Try to read the current settings from _CRS if it is valid. */
    474 	if (!sc->pl_crs_bad) {
    475 		rreq.in_dpf = DPF_OUTSIDE;
    476 		rreq.link_index = 0;
    477 		rreq.res_index = 0;
    478 		rreq.sc = sc;
    479 		status = AcpiWalkResources(sc->pl_handle, "_CRS",
    480 		    link_add_crs, &rreq);
    481 		if (ACPI_FAILURE(status)) {
    482 			aprint_error("%s: Unable to parse _CRS: %s\n",
    483 			    sc->pl_name, AcpiFormatException(status));
    484 			goto fail;
    485 		}
    486 	}
    487 
    488 	/*
    489 	 * Try to read the possible settings from _PRS.  Note that if the
    490 	 * _CRS is toast, we depend on having a working _PRS.  However, if
    491 	 * _CRS works, then it is ok for _PRS to be missing.
    492 	 */
    493 	rreq.in_dpf = DPF_OUTSIDE;
    494 	rreq.link_index = 0;
    495 	rreq.res_index = 0;
    496 	rreq.sc = sc;
    497 	status = AcpiWalkResources(sc->pl_handle, "_PRS",
    498 	    link_add_prs, &rreq);
    499 	if (ACPI_FAILURE(status) &&
    500 	    (status != AE_NOT_FOUND || sc->pl_crs_bad)) {
    501 		aprint_error("%s: Unable to parse _PRS: %s\n",
    502 		    sc->pl_name, AcpiFormatException(status));
    503 		goto fail;
    504 	}
    505 	if (boothowto & AB_VERBOSE) {
    506 		aprint_normal("%s: Links after initial probe:\n", sc->pl_name);
    507 		acpi_pci_link_dump(sc);
    508 	}
    509 
    510 	/* Verify initial IRQs if we have _PRS. */
    511 	if (status != AE_NOT_FOUND)
    512 		for (i = 0; i < sc->pl_num_links; i++)
    513 			if (!link_valid_irq(&sc->pl_links[i],
    514 			    sc->pl_links[i].l_irq))
    515 				sc->pl_links[i].l_irq = PCI_INVALID_IRQ;
    516 	if (boothowto & AB_VERBOSE) {
    517 		printf("%s: Links after initial validation:\n", sc->pl_name);
    518 		acpi_pci_link_dump(sc);
    519 	}
    520 
    521 	/* Save initial IRQs. */
    522 	for (i = 0; i < sc->pl_num_links; i++)
    523 		sc->pl_links[i].l_initial_irq = sc->pl_links[i].l_irq;
    524 
    525 	/*
    526 	 * Try to disable this link.  If successful, set the current IRQ to
    527 	 * zero and flags to indicate this link is not routed.  If we can't
    528 	 * run _DIS (i.e., the method doesn't exist), assume the initial
    529 	 * IRQ was routed by the BIOS.
    530 	 */
    531 #if 0	/* XXX causes spontaneaous resets on some systems. Disabled for now. */
    532 	if (ACPI_SUCCESS(AcpiEvaluateObject(sc->pl_handle, "_DIS", NULL,
    533 	    NULL)))
    534 		for (i = 0; i < sc->pl_num_links; i++)
    535 			sc->pl_links[i].l_irq = PCI_INVALID_IRQ;
    536 	else
    537 #endif
    538 		for (i = 0; i < sc->pl_num_links; i++)
    539 			if (PCI_INTERRUPT_VALID(sc->pl_links[i].l_irq))
    540 				sc->pl_links[i].l_routed = TRUE;
    541 	if (boothowto & AB_VERBOSE) {
    542 		printf("%s: Links after disable:\n", sc->pl_name);
    543 		acpi_pci_link_dump(sc);
    544 	}
    545 	ACPI_SERIAL_END(pci_link);
    546 	return (0);
    547 fail:
    548 	ACPI_SERIAL_END(pci_link);
    549 	for (i = 0; i < sc->pl_num_links; i++)
    550 		if (sc->pl_links[i].l_irqs != NULL)
    551 			free(sc->pl_links[i].l_irqs, M_PCI_LINK);
    552 	free(sc->pl_links, M_PCI_LINK);
    553 	return (ENXIO);
    554 }
    555 
    556 static uint8_t
    557 acpi_pci_link_search_irq(struct acpi_pci_link_softc *sc, int bus, int device,
    558 			 int pin)
    559 {
    560 	uint32_t value;
    561 	uint8_t func, maxfunc, ipin, iline;
    562 	pcitag_t tag;
    563 
    564 	tag = pci_make_tag(acpi_softc->sc_pc, bus, device, 0);
    565 	/* See if we have a valid device at function 0. */
    566 	value = pci_conf_read(acpi_softc->sc_pc, tag,  PCI_BHLC_REG);
    567 	if (PCI_HDRTYPE_TYPE(value) > PCI_HDRTYPE_PCB)
    568 		return (PCI_INVALID_IRQ);
    569 	if (PCI_HDRTYPE_MULTIFN(value))
    570 		maxfunc = 7;
    571 	else
    572 		maxfunc = 0;
    573 
    574 	/* Scan all possible functions at this device. */
    575 	for (func = 0; func <= maxfunc; func++) {
    576 		tag = pci_make_tag(acpi_softc->sc_pc, bus, device, func);
    577 		value = pci_conf_read(acpi_softc->sc_pc, tag, PCI_ID_REG);
    578 		if (PCI_VENDOR(value) == 0xffff)
    579 			continue;
    580 		value = pci_conf_read(acpi_softc->sc_pc, tag,
    581 		    PCI_INTERRUPT_REG);
    582 		ipin = PCI_INTERRUPT_PIN(value);
    583 		iline = PCI_INTERRUPT_LINE(value);
    584 
    585 		/*
    586 		 * See if it uses the pin in question.  Note that the passed
    587 		 * in pin uses 0 for A, .. 3 for D whereas the intpin
    588 		 * register uses 0 for no interrupt, 1 for A, .. 4 for D.
    589 		 */
    590 		if (ipin != pin + 1)
    591 			continue;
    592 		aprint_verbose(
    593 		    "%s: ACPI: Found matching pin for %d.%d.INT%c"
    594 	            " at func %d: %d\n",
    595 			    sc->pl_name, bus, device, pin + 'A', func, iline);
    596 		if (PCI_INTERRUPT_VALID(iline))
    597 			return (iline);
    598 	}
    599 	return (PCI_INVALID_IRQ);
    600 }
    601 
    602 /*
    603  * Find the link structure that corresponds to the resource index passed in
    604  * via 'source_index'.
    605  */
    606 static struct link *
    607 acpi_pci_link_lookup(struct acpi_pci_link_softc *sc, int source_index)
    608 {
    609 	int i;
    610 
    611 	for (i = 0; i < sc->pl_num_links; i++)
    612 		if (sc->pl_links[i].l_res_index == source_index)
    613 			return (&sc->pl_links[i]);
    614 	return (NULL);
    615 }
    616 
    617 void
    618 acpi_pci_link_add_reference(void *v, int index, int bus, int slot, int pin)
    619 {
    620 	struct acpi_pci_link_softc *sc = v;
    621 	struct link *link;
    622 	uint8_t bios_irq;
    623 
    624 	/* Bump the reference count. */
    625 	ACPI_SERIAL_BEGIN(pci_link);
    626 	link = acpi_pci_link_lookup(sc, index);
    627 	if (link == NULL) {
    628 		printf("%s: apparently invalid index %d\n", sc->pl_name, index);
    629 		ACPI_SERIAL_END(pci_link);
    630 		return;
    631 	}
    632 	link->l_references++;
    633 	if (link->l_routed)
    634 		pci_link_interrupt_weights[link->l_irq]++;
    635 
    636 	/*
    637 	 * The BIOS only routes interrupts via ISA IRQs using the ATPICs
    638 	 * (8259As).  Thus, if this link is routed via an ISA IRQ, go
    639 	 * look to see if the BIOS routed an IRQ for this link at the
    640 	 * indicated (bus, slot, pin).  If so, we prefer that IRQ for
    641 	 * this link and add that IRQ to our list of known-good IRQs.
    642 	 * This provides a good work-around for link devices whose _CRS
    643 	 * method is either broken or bogus.  We only use the value
    644 	 * returned by _CRS if we can't find a valid IRQ via this method
    645 	 * in fact.
    646 	 *
    647 	 * If this link is not routed via an ISA IRQ (because we are using
    648 	 * APIC for example), then don't bother looking up the BIOS IRQ
    649 	 * as if we find one it won't be valid anyway.
    650 	 */
    651 	if (!link->l_isa_irq) {
    652 		ACPI_SERIAL_END(pci_link);
    653 		return;
    654 	}
    655 
    656 	/* Try to find a BIOS IRQ setting from any matching devices. */
    657 	bios_irq = acpi_pci_link_search_irq(sc, bus, slot, pin);
    658 	if (!PCI_INTERRUPT_VALID(bios_irq)) {
    659 		ACPI_SERIAL_END(pci_link);
    660 		return;
    661 	}
    662 
    663 	/* Validate the BIOS IRQ. */
    664 	if (!link_valid_irq(link, bios_irq)) {
    665 		printf("%s: BIOS IRQ %u for %d.%d.INT%c is invalid\n",
    666 		    sc->pl_name, bios_irq, (int)bus, slot, pin + 'A');
    667 	} else if (!PCI_INTERRUPT_VALID(link->l_bios_irq)) {
    668 		link->l_bios_irq = bios_irq;
    669 		if (bios_irq < NUM_ISA_INTERRUPTS)
    670 			pci_link_bios_isa_irqs |= (1 << bios_irq);
    671 		if (bios_irq != link->l_initial_irq &&
    672 		    PCI_INTERRUPT_VALID(link->l_initial_irq))
    673 			printf(
    674 			    "%s: BIOS IRQ %u does not match initial IRQ %u\n",
    675 			    sc->pl_name, bios_irq, link->l_initial_irq);
    676 	} else if (bios_irq != link->l_bios_irq)
    677 		printf(
    678 	    "%s: BIOS IRQ %u for %d.%d.INT%c does not match "
    679 	    "previous BIOS IRQ %u\n",
    680 		    sc->pl_name, bios_irq, (int)bus, slot, pin + 'A',
    681 		    link->l_bios_irq);
    682 	ACPI_SERIAL_END(pci_link);
    683 }
    684 
    685 static ACPI_STATUS
    686 acpi_pci_link_srs_from_crs(struct acpi_pci_link_softc *sc, ACPI_BUFFER *srsbuf)
    687 {
    688 	ACPI_RESOURCE *resource, *end, newres, *resptr;
    689 	ACPI_BUFFER crsbuf;
    690 	ACPI_STATUS status;
    691 	struct link *link;
    692 	int i, in_dpf;
    693 
    694 	/* Fetch the _CRS. */
    695 	crsbuf.Pointer = NULL;
    696 	crsbuf.Length = ACPI_ALLOCATE_BUFFER;
    697 	status = AcpiGetCurrentResources(sc->pl_handle, &crsbuf);
    698 	if (ACPI_SUCCESS(status) && crsbuf.Pointer == NULL)
    699 		status = AE_NO_MEMORY;
    700 	if (ACPI_FAILURE(status)) {
    701 		aprint_verbose("%s: Unable to fetch current resources: %s\n",
    702 		    sc->pl_name, AcpiFormatException(status));
    703 		return (status);
    704 	}
    705 
    706 	/* Fill in IRQ resources via link structures. */
    707 	srsbuf->Pointer = NULL;
    708 	link = sc->pl_links;
    709 	i = 0;
    710 	in_dpf = DPF_OUTSIDE;
    711 	resource = (ACPI_RESOURCE *)crsbuf.Pointer;
    712 	end = (ACPI_RESOURCE *)((char *)crsbuf.Pointer + crsbuf.Length);
    713 	for (;;) {
    714 		switch (resource->Type) {
    715 		case ACPI_RESOURCE_TYPE_START_DEPENDENT:
    716 			switch (in_dpf) {
    717 			case DPF_OUTSIDE:
    718 				/* We've started the first DPF. */
    719 				in_dpf = DPF_FIRST;
    720 				break;
    721 			case DPF_FIRST:
    722 				/* We've started the second DPF. */
    723 				panic(
    724 		"%s: Multiple dependent functions within a current resource",
    725 				    __func__);
    726 				break;
    727 			}
    728 			resptr = NULL;
    729 			break;
    730 		case ACPI_RESOURCE_TYPE_END_DEPENDENT:
    731 			/* We are finished with DPF parsing. */
    732 			KASSERT(in_dpf != DPF_OUTSIDE);
    733 			in_dpf = DPF_OUTSIDE;
    734 			resptr = NULL;
    735 			break;
    736 		case ACPI_RESOURCE_TYPE_IRQ:
    737 			newres = link->l_prs_template;
    738 			resptr = &newres;
    739 			resptr->Data.Irq.InterruptCount = 1;
    740 			if (PCI_INTERRUPT_VALID(link->l_irq)) {
    741 				KASSERT(link->l_irq < NUM_ISA_INTERRUPTS);
    742 				resptr->Data.Irq.Interrupts[0] = link->l_irq;
    743 				resptr->Data.Irq.Triggering = link->l_trig;
    744 				resptr->Data.Irq.Polarity = link->l_pol;
    745 			} else
    746 				resptr->Data.Irq.Interrupts[0] = 0;
    747 			link++;
    748 			i++;
    749 			break;
    750 		case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
    751 			newres = link->l_prs_template;
    752 			resptr = &newres;
    753 			resptr->Data.ExtendedIrq.InterruptCount = 1;
    754 			if (PCI_INTERRUPT_VALID(link->l_irq)) {
    755 				resptr->Data.ExtendedIrq.Interrupts[0] =
    756 				    link->l_irq;
    757 				resptr->Data.ExtendedIrq.Triggering =
    758 				    link->l_trig;
    759 				resptr->Data.ExtendedIrq.Polarity = link->l_pol;
    760 			} else
    761 				resptr->Data.ExtendedIrq.Interrupts[0] = 0;
    762 			link++;
    763 			i++;
    764 			break;
    765 		default:
    766 			resptr = resource;
    767 		}
    768 		if (resptr != NULL) {
    769 			status = acpi_AppendBufferResource(srsbuf, resptr);
    770 			if (ACPI_FAILURE(status)) {
    771 				printf("%s: Unable to build resources: %s\n",
    772 				    sc->pl_name, AcpiFormatException(status));
    773 				if (srsbuf->Pointer != NULL)
    774 					AcpiOsFree(srsbuf->Pointer);
    775 				AcpiOsFree(crsbuf.Pointer);
    776 				return (status);
    777 			}
    778 		}
    779 		if (resource->Type == ACPI_RESOURCE_TYPE_END_TAG)
    780 			break;
    781 		resource = ACPI_NEXT_RESOURCE(resource);
    782 		if (resource >= end)
    783 			break;
    784 	}
    785 	AcpiOsFree(crsbuf.Pointer);
    786 	return (AE_OK);
    787 }
    788 
    789 static ACPI_STATUS
    790 acpi_pci_link_srs_from_links(struct acpi_pci_link_softc *sc,
    791     ACPI_BUFFER *srsbuf)
    792 {
    793 	ACPI_RESOURCE newres;
    794 	ACPI_STATUS status;
    795 	struct link *link;
    796 	int i;
    797 
    798 	/* Start off with an empty buffer. */
    799 	srsbuf->Pointer = NULL;
    800 	link = sc->pl_links;
    801 	for (i = 0; i < sc->pl_num_links; i++) {
    802 
    803 		/* Add a new IRQ resource from each link. */
    804 		link = &sc->pl_links[i];
    805 		newres = link->l_prs_template;
    806 		if (newres.Type == ACPI_RESOURCE_TYPE_IRQ) {
    807 
    808 			/* Build an IRQ resource. */
    809 			newres.Data.Irq.InterruptCount = 1;
    810 			if (PCI_INTERRUPT_VALID(link->l_irq)) {
    811 				KASSERT(link->l_irq < NUM_ISA_INTERRUPTS);
    812 				newres.Data.Irq.Interrupts[0] = link->l_irq;
    813 				newres.Data.Irq.Triggering = link->l_trig;
    814 				newres.Data.Irq.Polarity = link->l_pol;
    815 			} else
    816 				newres.Data.Irq.Interrupts[0] = 0;
    817 		} else {
    818 
    819 			/* Build an ExtIRQ resuorce. */
    820 			newres.Data.ExtendedIrq.InterruptCount = 1;
    821 			if (PCI_INTERRUPT_VALID(link->l_irq)) {
    822 				newres.Data.ExtendedIrq.Interrupts[0] =
    823 				    link->l_irq;
    824 				newres.Data.ExtendedIrq.Triggering =
    825 				    link->l_trig;
    826 				newres.Data.ExtendedIrq.Polarity =
    827 				    link->l_pol;
    828 			} else {
    829 				newres.Data.ExtendedIrq.Interrupts[0] = 0;
    830 			}
    831 		}
    832 
    833 		/* Add the new resource to the end of the _SRS buffer. */
    834 		status = acpi_AppendBufferResource(srsbuf, &newres);
    835 		if (ACPI_FAILURE(status)) {
    836 			printf("%s: Unable to build resources: %s\n",
    837 			    sc->pl_name, AcpiFormatException(status));
    838 			if (srsbuf->Pointer != NULL)
    839 				AcpiOsFree(srsbuf->Pointer);
    840 			return (status);
    841 		}
    842 	}
    843 	return (AE_OK);
    844 }
    845 
    846 static ACPI_STATUS
    847 acpi_pci_link_srs(struct acpi_pci_link_softc *sc, ACPI_BUFFER *srsbuf)
    848 {
    849 	ACPI_STATUS status;
    850 
    851 	if (sc->pl_crs_bad)
    852 		status = acpi_pci_link_srs_from_links(sc, srsbuf);
    853 	else
    854 		status = acpi_pci_link_srs_from_crs(sc, srsbuf);
    855 
    856 	/* Write out new resources via _SRS. */
    857 	return AcpiSetCurrentResources(sc->pl_handle, srsbuf);
    858 }
    859 
    860 static ACPI_STATUS
    861 acpi_pci_link_route_irqs(struct acpi_pci_link_softc *sc, int *irq, int *pol,
    862 			 int *trig)
    863 {
    864 	ACPI_RESOURCE *resource, *end;
    865 	ACPI_BUFFER srsbuf;
    866 	ACPI_STATUS status;
    867 	struct link *link;
    868 	int i, is_ext = 0;
    869 
    870 	status = acpi_pci_link_srs(sc, &srsbuf);
    871 	if (ACPI_FAILURE(status)) {
    872 		printf("%s: _SRS failed: %s\n",
    873 		    sc->pl_name, AcpiFormatException(status));
    874 		return (status);
    875 	}
    876 	/*
    877 	 * Perform acpi_config_intr() on each IRQ resource if it was just
    878 	 * routed for the first time.
    879 	 */
    880 	link = sc->pl_links;
    881 	i = 0;
    882 	resource = (ACPI_RESOURCE *)srsbuf.Pointer;
    883 	end = (ACPI_RESOURCE *)((char *)srsbuf.Pointer + srsbuf.Length);
    884 	for (;;) {
    885 		if (resource->Type == ACPI_RESOURCE_TYPE_END_TAG)
    886 			break;
    887 		switch (resource->Type) {
    888 		case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
    889 			is_ext = 1;
    890 			/* FALLTHROUGH */
    891 		case ACPI_RESOURCE_TYPE_IRQ:
    892 			/*
    893 			 * Only configure the interrupt and update the
    894 			 * weights if this link has a valid IRQ and was
    895 			 * previously unrouted.
    896 			 */
    897 			if (!link->l_routed &&
    898 			    PCI_INTERRUPT_VALID(link->l_irq)) {
    899 				*trig = is_ext ?
    900 				    resource->Data.ExtendedIrq.Triggering :
    901 				    resource->Data.Irq.Triggering;
    902 				*pol = is_ext ?
    903 				    resource->Data.ExtendedIrq.Polarity :
    904 				    resource->Data.Irq.Polarity;
    905 				*irq = is_ext ?
    906 				    resource->Data.ExtendedIrq.Interrupts[0] :
    907 				    resource->Data.Irq.Interrupts[0];
    908 				link->l_routed = TRUE;
    909 				pci_link_interrupt_weights[link->l_irq] +=
    910 				    link->l_references;
    911 			}
    912 			link++;
    913 			i++;
    914 			break;
    915 		}
    916 		resource = ACPI_NEXT_RESOURCE(resource);
    917 		if (resource >= end)
    918 			break;
    919 	}
    920 	AcpiOsFree(srsbuf.Pointer);
    921 	return (AE_OK);
    922 }
    923 
    924 static void
    925 acpi_pci_link_resume(int why, void *arg)
    926 {
    927 	struct acpi_pci_link_softc *sc = arg;
    928 	ACPI_BUFFER srsbuf;
    929 
    930 	switch (why) {
    931 	case PWR_RESUME:
    932 		ACPI_SERIAL_BEGIN(pci_link);
    933 		if (ACPI_SUCCESS(acpi_pci_link_srs(sc, &srsbuf)))
    934 			AcpiOsFree(srsbuf.Pointer);
    935 		ACPI_SERIAL_END(pci_link);
    936 	default:
    937 		break;
    938 	}
    939 }
    940 
    941 /*
    942  * Pick an IRQ to use for this unrouted link.
    943  */
    944 static uint8_t
    945 acpi_pci_link_choose_irq(struct acpi_pci_link_softc *sc, struct link *link)
    946 {
    947 	u_int8_t best_irq, pos_irq;
    948 	int best_weight, pos_weight, i;
    949 
    950 	KASSERT(!link->l_routed);
    951 	KASSERT(!PCI_INTERRUPT_VALID(link->l_irq));
    952 
    953 	/*
    954 	 * If we have a valid BIOS IRQ, use that.  We trust what the BIOS
    955 	 * says it routed over what _CRS says the link thinks is routed.
    956 	 */
    957 	if (PCI_INTERRUPT_VALID(link->l_bios_irq))
    958 		return (link->l_bios_irq);
    959 
    960 	/*
    961 	 * If we don't have a BIOS IRQ but do have a valid IRQ from _CRS,
    962 	 * then use that.
    963 	 */
    964 	if (PCI_INTERRUPT_VALID(link->l_initial_irq))
    965 		return (link->l_initial_irq);
    966 
    967 	/*
    968 	 * Ok, we have no useful hints, so we have to pick from the
    969 	 * possible IRQs.  For ISA IRQs we only use interrupts that
    970 	 * have already been used by the BIOS.
    971 	 */
    972 	best_irq = PCI_INVALID_IRQ;
    973 	best_weight = INT_MAX;
    974 	for (i = 0; i < link->l_num_irqs; i++) {
    975 		pos_irq = link->l_irqs[i];
    976 		if (pos_irq < NUM_ISA_INTERRUPTS &&
    977 		    (pci_link_bios_isa_irqs & 1 << pos_irq) == 0)
    978 			continue;
    979 		pos_weight = pci_link_interrupt_weights[pos_irq];
    980 		if (pos_weight < best_weight) {
    981 			best_weight = pos_weight;
    982 			best_irq = pos_irq;
    983 		}
    984 	}
    985 
    986 	/*
    987 	 * If this is an ISA IRQ, try using the SCI if it is also an ISA
    988 	 * interrupt as a fallback.
    989 	 */
    990 	if (link->l_isa_irq) {
    991 		pos_irq = AcpiGbl_FADT->SciInt;
    992 		pos_weight = pci_link_interrupt_weights[pos_irq];
    993 		if (pos_weight < best_weight) {
    994 			best_weight = pos_weight;
    995 			best_irq = pos_irq;
    996 		}
    997 	}
    998 
    999 	if (PCI_INTERRUPT_VALID(best_irq)) {
   1000 		aprint_verbose("%s: Picked IRQ %u with weight %d\n",
   1001 		    sc->pl_name, best_irq, best_weight);
   1002 	} else
   1003 		printf("%s: Unable to choose an IRQ\n", sc->pl_name);
   1004 	return (best_irq);
   1005 }
   1006 
   1007 int
   1008 acpi_pci_link_route_interrupt(void *v, int index, int *irq, int *pol, int *trig)
   1009 {
   1010 	struct acpi_pci_link_softc *sc = v;
   1011 	struct link *link;
   1012 
   1013 	ACPI_SERIAL_BEGIN(pci_link);
   1014 	link = acpi_pci_link_lookup(sc, index);
   1015 	if (link == NULL)
   1016 		panic("%s: apparently invalid index %d", __func__, index);
   1017 
   1018 	/*
   1019 	 * If this link device is already routed to an interrupt, just return
   1020 	 * the interrupt it is routed to.
   1021 	 */
   1022 	if (link->l_routed) {
   1023 		KASSERT(PCI_INTERRUPT_VALID(link->l_irq));
   1024 		ACPI_SERIAL_END(pci_link);
   1025 		*irq = link->l_irq;
   1026 		*pol = link->l_pol;
   1027 		*trig = link->l_trig;
   1028 		return (link->l_irq);
   1029 	}
   1030 
   1031 	/* Choose an IRQ if we need one. */
   1032 	if (!PCI_INTERRUPT_VALID(link->l_irq)) {
   1033 		link->l_irq = acpi_pci_link_choose_irq(sc, link);
   1034 
   1035 		/*
   1036 		 * Try to route the interrupt we picked.  If it fails, then
   1037 		 * assume the interrupt is not routed.
   1038 		 */
   1039 		if (PCI_INTERRUPT_VALID(link->l_irq)) {
   1040 			acpi_pci_link_route_irqs(sc, irq, pol, trig);
   1041 			if (!link->l_routed)
   1042 				link->l_irq = PCI_INVALID_IRQ;
   1043 			else {
   1044 				link->l_pol = *pol;
   1045 				link->l_trig = *trig;
   1046 			}
   1047 		}
   1048 	}
   1049 	ACPI_SERIAL_END(pci_link);
   1050 
   1051 	return (link->l_irq);
   1052 }
   1053 
   1054 /*
   1055  * This is gross, but we abuse the identify routine to perform one-time
   1056  * SYSINIT() style initialization for the driver.
   1057  */
   1058 static void
   1059 acpi_pci_link_init(struct acpi_pci_link_softc *sc)
   1060 {
   1061 	ACPI_BUFFER buf;
   1062 
   1063 	/*
   1064 	 * If the SCI is an ISA IRQ, add it to the bitmask of known good
   1065 	 * ISA IRQs.
   1066 	 *
   1067 	 * XXX: If we are using the APIC, the SCI might have been
   1068 	 * rerouted to an APIC pin in which case this is invalid.  However,
   1069 	 * if we are using the APIC, we also shouldn't be having any PCI
   1070 	 * interrupts routed via ISA IRQs, so this is probably ok.
   1071 	 */
   1072 	if (AcpiGbl_FADT->SciInt < NUM_ISA_INTERRUPTS)
   1073 		pci_link_bios_isa_irqs |= (1 << AcpiGbl_FADT->SciInt);
   1074 
   1075         sc->pl_powerhook = powerhook_establish("acpi_pci_link",
   1076 	    acpi_pci_link_resume, sc);
   1077         if (sc->pl_powerhook == NULL)
   1078                 aprint_normal("can't establish powerhook\n");
   1079 
   1080 	buf.Length = sizeof (sc->pl_name);
   1081 	buf.Pointer = sc->pl_name;
   1082 
   1083 	if (ACPI_FAILURE(AcpiGetName(sc->pl_handle, ACPI_SINGLE_NAME, &buf)))
   1084 		snprintf(sc->pl_name, sizeof (sc->pl_name), "%s",
   1085 		    "ACPI link device");
   1086 
   1087 	acpi_pci_link_attach(sc);
   1088 }
   1089 
   1090 void *
   1091 acpi_pci_link_devbyhandle(ACPI_HANDLE handle)
   1092 {
   1093 	struct acpi_pci_link_softc *sc;
   1094 
   1095 	TAILQ_FOREACH(sc, &acpi_pci_linkdevs, pl_list) {
   1096 		if (sc->pl_handle == handle)
   1097 			return sc;
   1098 	}
   1099 
   1100 	sc = malloc(sizeof (*sc), M_PCI_LINK, M_NOWAIT|M_ZERO);
   1101 	if (sc == NULL)
   1102 		return NULL;
   1103 
   1104 	sc->pl_handle = handle;
   1105 
   1106 	acpi_pci_link_init(sc);
   1107 
   1108 	TAILQ_INSERT_TAIL(&acpi_pci_linkdevs, sc, pl_list);
   1109 
   1110 	return (void *)sc;
   1111 }
   1112 
   1113 ACPI_HANDLE
   1114 acpi_pci_link_handle(void *v)
   1115 {
   1116 	struct acpi_pci_link_softc *sc = v;
   1117 
   1118 	return sc->pl_handle;
   1119 }
   1120 
   1121 char *
   1122 acpi_pci_link_name(void *v)
   1123 {
   1124 	struct acpi_pci_link_softc *sc = v;
   1125 
   1126 	return sc->pl_name;
   1127 }
   1128 
   1129 
   1130 /*
   1131  * Append an ACPI_RESOURCE to an ACPI_BUFFER.
   1132  *
   1133  * Given a pointer to an ACPI_RESOURCE structure, expand the ACPI_BUFFER
   1134  * provided to contain it.  If the ACPI_BUFFER is empty, allocate a sensible
   1135  * backing block.  If the ACPI_RESOURCE is NULL, return an empty set of
   1136  * resources.
   1137  */
   1138 #define ACPI_INITIAL_RESOURCE_BUFFER_SIZE	512
   1139 
   1140 static ACPI_STATUS
   1141 acpi_AppendBufferResource(ACPI_BUFFER *buf, ACPI_RESOURCE *res)
   1142 {
   1143 	ACPI_RESOURCE	*rp;
   1144 	void		*newp;
   1145 
   1146 	/* Initialise the buffer if necessary. */
   1147 	if (buf->Pointer == NULL) {
   1148 	buf->Length = ACPI_INITIAL_RESOURCE_BUFFER_SIZE;
   1149 	if ((buf->Pointer = AcpiOsAllocate(buf->Length)) == NULL)
   1150 		return (AE_NO_MEMORY);
   1151 	rp = (ACPI_RESOURCE *)buf->Pointer;
   1152 	rp->Type =  ACPI_RESOURCE_TYPE_END_TAG;
   1153 	rp->Length = 0;
   1154 	}
   1155 
   1156 	if (res == NULL)
   1157 		return (AE_OK);
   1158 
   1159 	/*
   1160 	 * Scan the current buffer looking for the terminator.
   1161 	 * This will either find the terminator or hit the end
   1162 	 * of the buffer and return an error.
   1163 	 */
   1164 	rp = (ACPI_RESOURCE *)buf->Pointer;
   1165 	for (;;) {
   1166 		/* Range check, don't go outside the buffer */
   1167 		if (rp >= (ACPI_RESOURCE *)((u_int8_t *)buf->Pointer +
   1168 		    buf->Length))
   1169 			return (AE_BAD_PARAMETER);
   1170 		if (rp->Type ==  ACPI_RESOURCE_TYPE_END_TAG || rp->Length == 0)
   1171 			break;
   1172 		rp = ACPI_NEXT_RESOURCE(rp);
   1173 	}
   1174 
   1175 	/*
   1176 	 * Check the size of the buffer and expand if required.
   1177 	 *
   1178 	 * Required size is:
   1179 	 *	size of existing resources before terminator +
   1180 	 *	size of new resource and header +
   1181 	 * 	size of terminator.
   1182 	 *
   1183 	 * Note that this loop should really only run once, unless
   1184 	 * for some reason we are stuffing a *really* huge resource.
   1185 	 */
   1186 	while ((((u_int8_t *)rp - (u_int8_t *)buf->Pointer) +
   1187 	    res->Length + ACPI_RS_SIZE_NO_DATA +
   1188 	    ACPI_RS_SIZE_MIN) >= buf->Length) {
   1189 		if ((newp = AcpiOsAllocate(buf->Length * 2)) == NULL)
   1190 			return (AE_NO_MEMORY);
   1191 		memcpy(newp, buf->Pointer, buf->Length);
   1192 		rp = (ACPI_RESOURCE *)((u_int8_t *)newp +
   1193 		   ((u_int8_t *)rp - (u_int8_t *)buf->Pointer));
   1194 		AcpiOsFree(buf->Pointer);
   1195 		buf->Pointer = newp;
   1196 		buf->Length += buf->Length;
   1197 	}
   1198 
   1199 	/* Insert the new resource. */
   1200 	memcpy(rp, res, res->Length + ACPI_RS_SIZE_NO_DATA);
   1201 
   1202 	/* And add the terminator. */
   1203 	rp = ACPI_NEXT_RESOURCE(rp);
   1204 	rp->Type =  ACPI_RESOURCE_TYPE_END_TAG;
   1205 	rp->Length = 0;
   1206 
   1207 	return (AE_OK);
   1208 }
   1209