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acpi_pci_machdep.c revision 1.14
      1 /* $NetBSD: acpi_pci_machdep.c,v 1.14 2020/01/23 11:59:37 jmcneill Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2018 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Jared McNeill <jmcneill (at) invisible.ca>.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #define	_INTR_PRIVATE
     33 
     34 #include <sys/cdefs.h>
     35 __KERNEL_RCSID(0, "$NetBSD: acpi_pci_machdep.c,v 1.14 2020/01/23 11:59:37 jmcneill Exp $");
     36 
     37 #include <sys/param.h>
     38 #include <sys/bus.h>
     39 #include <sys/device.h>
     40 #include <sys/intr.h>
     41 #include <sys/systm.h>
     42 #include <sys/kernel.h>
     43 #include <sys/extent.h>
     44 #include <sys/queue.h>
     45 #include <sys/mutex.h>
     46 #include <sys/kmem.h>
     47 
     48 #include <machine/cpu.h>
     49 
     50 #include <arm/cpufunc.h>
     51 
     52 #include <arm/pic/picvar.h>
     53 
     54 #include <dev/pci/pcireg.h>
     55 #include <dev/pci/pcivar.h>
     56 #include <dev/pci/pciconf.h>
     57 
     58 #include <dev/acpi/acpivar.h>
     59 #include <dev/acpi/acpi_mcfg.h>
     60 #include <dev/acpi/acpi_pci.h>
     61 
     62 #include <arm/acpi/acpi_iort.h>
     63 #include <arm/acpi/acpi_pci_machdep.h>
     64 
     65 #include <arm/pci/pci_msi_machdep.h>
     66 
     67 struct acpi_pci_prt {
     68 	u_int				prt_segment;
     69 	u_int				prt_bus;
     70 	ACPI_HANDLE			prt_handle;
     71 	TAILQ_ENTRY(acpi_pci_prt)	prt_list;
     72 };
     73 
     74 static TAILQ_HEAD(, acpi_pci_prt) acpi_pci_irq_routes =
     75     TAILQ_HEAD_INITIALIZER(acpi_pci_irq_routes);
     76 
     77 struct acpi_pci_pct {
     78 	struct acpi_pci_context		pct_ap;
     79 	TAILQ_ENTRY(acpi_pci_pct)	pct_list;
     80 };
     81 
     82 static TAILQ_HEAD(, acpi_pci_pct) acpi_pci_chipset_tags =
     83     TAILQ_HEAD_INITIALIZER(acpi_pci_chipset_tags);
     84 
     85 struct acpi_pci_intr;
     86 
     87 struct acpi_pci_intr {
     88 	struct pic_softc		pi_pic;
     89 	int				pi_irqbase;
     90 	int				pi_irq;
     91 	uint32_t			pi_unblocked;
     92 	void				*pi_ih;
     93 	TAILQ_ENTRY(acpi_pci_intr)	pi_list;
     94 };
     95 
     96 static TAILQ_HEAD(, acpi_pci_intr) acpi_pci_intrs =
     97     TAILQ_HEAD_INITIALIZER(acpi_pci_intrs);
     98 
     99 static const struct acpi_pci_quirk acpi_pci_quirks[] = {
    100 	/* OEM ID	OEM Table ID	Revision	Seg	Func */
    101 	{ "AMAZON",	"GRAVITON",	0,		-1,	acpi_pci_graviton_init },
    102 	{ "ARMLTD",	"ARMN1SDP",	0x20181101,	0,	acpi_pci_n1sdp_init },
    103 	{ "ARMLTD",	"ARMN1SDP",	0x20181101,	1,	acpi_pci_n1sdp_init },
    104 };
    105 
    106 pci_chipset_tag_t acpi_pci_md_get_chipset_tag(struct acpi_softc *, int, int);
    107 
    108 static void	acpi_pci_md_attach_hook(device_t, device_t,
    109 				       struct pcibus_attach_args *);
    110 static int	acpi_pci_md_bus_maxdevs(void *, int);
    111 static pcitag_t	acpi_pci_md_make_tag(void *, int, int, int);
    112 static void	acpi_pci_md_decompose_tag(void *, pcitag_t, int *, int *, int *);
    113 static u_int	acpi_pci_md_get_segment(void *);
    114 static uint32_t	acpi_pci_md_get_devid(void *, uint32_t);
    115 static pcireg_t	acpi_pci_md_conf_read(void *, pcitag_t, int);
    116 static void	acpi_pci_md_conf_write(void *, pcitag_t, int, pcireg_t);
    117 static int	acpi_pci_md_conf_hook(void *, int, int, int, pcireg_t);
    118 static void	acpi_pci_md_conf_interrupt(void *, int, int, int, int, int *);
    119 
    120 static int	acpi_pci_md_intr_map(const struct pci_attach_args *,
    121 				    pci_intr_handle_t *);
    122 static const char *acpi_pci_md_intr_string(void *, pci_intr_handle_t,
    123 					  char *, size_t);
    124 static const struct evcnt *acpi_pci_md_intr_evcnt(void *, pci_intr_handle_t);
    125 static int	acpi_pci_md_intr_setattr(void *, pci_intr_handle_t *, int,
    126 					uint64_t);
    127 static void *	acpi_pci_md_intr_establish(void *, pci_intr_handle_t,
    128 					 int, int (*)(void *), void *,
    129 					 const char *);
    130 static void	acpi_pci_md_intr_disestablish(void *, void *);
    131 
    132 struct arm32_pci_chipset arm_acpi_pci_chipset = {
    133 	.pc_attach_hook = acpi_pci_md_attach_hook,
    134 	.pc_bus_maxdevs = acpi_pci_md_bus_maxdevs,
    135 	.pc_make_tag = acpi_pci_md_make_tag,
    136 	.pc_decompose_tag = acpi_pci_md_decompose_tag,
    137 	.pc_get_segment = acpi_pci_md_get_segment,
    138 	.pc_get_devid = acpi_pci_md_get_devid,
    139 	.pc_conf_read = acpi_pci_md_conf_read,
    140 	.pc_conf_write = acpi_pci_md_conf_write,
    141 	.pc_conf_hook = acpi_pci_md_conf_hook,
    142 	.pc_conf_interrupt = acpi_pci_md_conf_interrupt,
    143 
    144 	.pc_intr_map = acpi_pci_md_intr_map,
    145 	.pc_intr_string = acpi_pci_md_intr_string,
    146 	.pc_intr_evcnt = acpi_pci_md_intr_evcnt,
    147 	.pc_intr_setattr = acpi_pci_md_intr_setattr,
    148 	.pc_intr_establish = acpi_pci_md_intr_establish,
    149 	.pc_intr_disestablish = acpi_pci_md_intr_disestablish,
    150 };
    151 
    152 static ACPI_STATUS
    153 acpi_pci_md_pci_link(ACPI_HANDLE handle, pci_chipset_tag_t pc, int bus)
    154 {
    155 	ACPI_PCI_ROUTING_TABLE *prt;
    156 	ACPI_HANDLE linksrc;
    157 	ACPI_BUFFER buf;
    158 	ACPI_STATUS rv;
    159 	void *linkdev;
    160 
    161 	rv = acpi_get(handle, &buf, AcpiGetIrqRoutingTable);
    162 	if (ACPI_FAILURE(rv))
    163 		return rv;
    164 
    165 	for (char *p = buf.Pointer; ; p += prt->Length) {
    166 		prt = (ACPI_PCI_ROUTING_TABLE *)p;
    167 		if (prt->Length == 0)
    168 			break;
    169 
    170 		const u_int dev = ACPI_HIWORD(prt->Address);
    171 		if (prt->Source[0] != 0) {
    172 			aprint_debug("ACPI: %s dev %u INT%c on lnkdev %s\n",
    173 			    acpi_name(handle), dev, 'A' + (prt->Pin & 3), prt->Source);
    174 			rv = AcpiGetHandle(ACPI_ROOT_OBJECT, prt->Source, &linksrc);
    175 			if (ACPI_FAILURE(rv)) {
    176 				aprint_debug("ACPI: AcpiGetHandle failed for '%s': %s\n",
    177 				    prt->Source, AcpiFormatException(rv));
    178 				continue;
    179 			}
    180 
    181 			linkdev = acpi_pci_link_devbyhandle(linksrc);
    182 			acpi_pci_link_add_reference(linkdev, pc, 0, bus, dev, prt->Pin & 3);
    183 		} else {
    184 			aprint_debug("ACPI: %s dev %u INT%c on globint %d\n",
    185 			    acpi_name(handle), dev, 'A' + (prt->Pin & 3), prt->SourceIndex);
    186 		}
    187 	}
    188 
    189 	return AE_OK;
    190 }
    191 
    192 static void
    193 acpi_pci_md_attach_hook(device_t parent, device_t self,
    194     struct pcibus_attach_args *pba)
    195 {
    196 	struct acpi_pci_context *ap = pba->pba_pc->pc_conf_v;
    197 	struct acpi_pci_prt *prt, *prtp;
    198 	struct acpi_devnode *ad;
    199 	ACPI_HANDLE handle;
    200 	int seg, bus, dev, func;
    201 
    202 	seg = ap->ap_seg;
    203 	handle = NULL;
    204 
    205 	if (pba->pba_bridgetag) {
    206 		/*
    207 		 * Find the PCI address of our parent bridge and look for the
    208 		 * corresponding ACPI device node. If there is no node for this
    209 		 * bus, use the parent bridge routing information.
    210 		 */
    211 		acpi_pci_md_decompose_tag(NULL, *pba->pba_bridgetag, &bus, &dev, &func);
    212 		ad = acpi_pcidev_find(seg, bus, dev, func);
    213 		if (ad != NULL) {
    214 			handle = ad->ad_handle;
    215 		} else {
    216 			/* No routes defined for this bus, copy from parent */
    217 			TAILQ_FOREACH(prtp, &acpi_pci_irq_routes, prt_list)
    218 				if (prtp->prt_bus == bus) {
    219 					handle = prtp->prt_handle;
    220 					break;
    221 				}
    222 		}
    223 	} else {
    224 		/*
    225 		 * Lookup the ACPI device node for the root bus.
    226 		 */
    227 		ad = acpi_pciroot_find(seg, 0);
    228 		if (ad != NULL)
    229 			handle = ad->ad_handle;
    230 	}
    231 
    232 	if (handle != NULL) {
    233 		prt = kmem_alloc(sizeof(*prt), KM_SLEEP);
    234 		prt->prt_bus = pba->pba_bus;
    235 		prt->prt_segment = ap->ap_seg;
    236 		prt->prt_handle = handle;
    237 		TAILQ_INSERT_TAIL(&acpi_pci_irq_routes, prt, prt_list);
    238 	}
    239 
    240 	acpimcfg_map_bus(self, pba->pba_pc, pba->pba_bus);
    241 
    242 	if (ad != NULL) {
    243 		/*
    244 		 * This is a new ACPI managed bus. Add PCI link references.
    245 		 */
    246 		acpi_pci_md_pci_link(ad->ad_handle, pba->pba_pc, pba->pba_bus);
    247 	}
    248 }
    249 
    250 static int
    251 acpi_pci_md_bus_maxdevs(void *v, int busno)
    252 {
    253 	return 32;
    254 }
    255 
    256 static pcitag_t
    257 acpi_pci_md_make_tag(void *v, int b, int d, int f)
    258 {
    259 	return (b << 16) | (d << 11) | (f << 8);
    260 }
    261 
    262 static void
    263 acpi_pci_md_decompose_tag(void *v, pcitag_t tag, int *bp, int *dp, int *fp)
    264 {
    265 	if (bp)
    266 		*bp = (tag >> 16) & 0xff;
    267 	if (dp)
    268 		*dp = (tag >> 11) & 0x1f;
    269 	if (fp)
    270 		*fp = (tag >> 8) & 0x7;
    271 }
    272 
    273 static u_int
    274 acpi_pci_md_get_segment(void *v)
    275 {
    276 	struct acpi_pci_context * const ap = v;
    277 
    278 	return ap->ap_seg;
    279 }
    280 
    281 static uint32_t
    282 acpi_pci_md_get_devid(void *v, uint32_t devid)
    283 {
    284 	struct acpi_pci_context * const ap = v;
    285 
    286 	return acpi_iort_pci_root_map(ap->ap_seg, devid);
    287 }
    288 
    289 static pcireg_t
    290 acpi_pci_md_conf_read(void *v, pcitag_t tag, int offset)
    291 {
    292 	struct acpi_pci_context * const ap = v;
    293 	pcireg_t val;
    294 
    295 	if (offset < 0 || offset >= PCI_EXTCONF_SIZE)
    296 		return (pcireg_t) -1;
    297 
    298 	if (ap->ap_conf_read != NULL)
    299 		ap->ap_conf_read(&ap->ap_pc, tag, offset, &val);
    300 	else
    301 		acpimcfg_conf_read(&ap->ap_pc, tag, offset, &val);
    302 
    303 	return val;
    304 }
    305 
    306 static void
    307 acpi_pci_md_conf_write(void *v, pcitag_t tag, int offset, pcireg_t val)
    308 {
    309 	struct acpi_pci_context * const ap = v;
    310 
    311 	if (offset < 0 || offset >= PCI_EXTCONF_SIZE)
    312 		return;
    313 
    314 	if (ap->ap_conf_write != NULL)
    315 		ap->ap_conf_write(&ap->ap_pc, tag, offset, val);
    316 	else
    317 		acpimcfg_conf_write(&ap->ap_pc, tag, offset, val);
    318 }
    319 
    320 static int
    321 acpi_pci_md_conf_hook(void *v, int b, int d, int f, pcireg_t id)
    322 {
    323 	return PCI_CONF_DEFAULT;
    324 }
    325 
    326 static void
    327 acpi_pci_md_conf_interrupt(void *v, int bus, int dev, int ipin, int sqiz, int *ilinep)
    328 {
    329 }
    330 
    331 static struct acpi_pci_prt *
    332 acpi_pci_md_intr_find_prt(pci_chipset_tag_t pc, u_int bus)
    333 {
    334 	struct acpi_pci_prt *prt, *prtp;
    335 	u_int segment;
    336 
    337 	segment = pci_get_segment(pc);
    338 
    339 	prt = NULL;
    340 	TAILQ_FOREACH(prtp, &acpi_pci_irq_routes, prt_list)
    341 		if (prtp->prt_segment == segment && prtp->prt_bus == bus) {
    342 			prt = prtp;
    343 			break;
    344 		}
    345 
    346 	return prt;
    347 }
    348 
    349 static int
    350 acpi_pci_md_intr_map(const struct pci_attach_args *pa, pci_intr_handle_t *ih)
    351 {
    352 	struct acpi_pci_prt *prt;
    353 	ACPI_PCI_ROUTING_TABLE *tab;
    354 	int line, pol, trig, error;
    355 	ACPI_HANDLE linksrc;
    356 	ACPI_BUFFER buf;
    357 	void *linkdev;
    358 
    359 	if (pa->pa_intrpin == PCI_INTERRUPT_PIN_NONE)
    360 		return EINVAL;
    361 
    362 	prt = acpi_pci_md_intr_find_prt(pa->pa_pc, pa->pa_bus);
    363 	if (prt == NULL)
    364 		return ENXIO;
    365 
    366 	if (ACPI_FAILURE(acpi_get(prt->prt_handle, &buf, AcpiGetIrqRoutingTable)))
    367 		return EIO;
    368 
    369 	error = ENOENT;
    370 	for (char *p = buf.Pointer; ; p += tab->Length) {
    371 		tab = (ACPI_PCI_ROUTING_TABLE *)p;
    372 		if (tab->Length == 0)
    373 			break;
    374 
    375 		if (pa->pa_device == ACPI_HIWORD(tab->Address) &&
    376 		    (pa->pa_intrpin - 1) == (tab->Pin & 3)) {
    377 			if (tab->Source[0] != 0) {
    378 				if (ACPI_FAILURE(AcpiGetHandle(ACPI_ROOT_OBJECT, tab->Source, &linksrc)))
    379 					goto done;
    380 				linkdev = acpi_pci_link_devbyhandle(linksrc);
    381 				*ih = acpi_pci_link_route_interrupt(linkdev,
    382 				    pa->pa_pc, tab->SourceIndex,
    383 				    &line, &pol, &trig);
    384 				error = 0;
    385 				goto done;
    386 			} else {
    387 				*ih = tab->SourceIndex;
    388 				error = 0;
    389 				goto done;
    390 			}
    391 		}
    392 	}
    393 
    394 done:
    395 	ACPI_FREE(buf.Pointer);
    396 	return error;
    397 }
    398 
    399 static const char *
    400 acpi_pci_md_intr_string(void *v, pci_intr_handle_t ih, char *buf, size_t len)
    401 {
    402 	const int irq = __SHIFTOUT(ih, ARM_PCI_INTR_IRQ);
    403 	const int vec = __SHIFTOUT(ih, ARM_PCI_INTR_MSI_VEC);
    404 
    405 	if (ih & ARM_PCI_INTR_MSIX)
    406 		snprintf(buf, len, "irq %d (MSI-X vec %d)", irq, vec);
    407 	else if (ih & ARM_PCI_INTR_MSI)
    408 		snprintf(buf, len, "irq %d (MSI vec %d)", irq, vec);
    409 	else
    410 		snprintf(buf, len, "irq %d", irq);
    411 
    412 	return buf;
    413 }
    414 
    415 static const struct evcnt *
    416 acpi_pci_md_intr_evcnt(void *v, pci_intr_handle_t ih)
    417 {
    418 	return NULL;
    419 }
    420 
    421 static int
    422 acpi_pci_md_intr_setattr(void *v, pci_intr_handle_t *ih, int attr, uint64_t data)
    423 {
    424 	switch (attr) {
    425 	case PCI_INTR_MPSAFE:
    426 		if (data)
    427 			*ih |= ARM_PCI_INTR_MPSAFE;
    428 		else
    429 			*ih &= ~ARM_PCI_INTR_MPSAFE;
    430 		return 0;
    431 	default:
    432 		return ENODEV;
    433 	}
    434 }
    435 
    436 static struct acpi_pci_intr *
    437 acpi_pci_md_intr_lookup(int irq)
    438 {
    439 	struct acpi_pci_intr *pi;
    440 
    441 	TAILQ_FOREACH(pi, &acpi_pci_intrs, pi_list)
    442 		if (pi->pi_irq == irq)
    443 			return pi;
    444 
    445 	return NULL;
    446 }
    447 
    448 static void
    449 acpi_pci_md_unblock_irqs(struct pic_softc *pic, size_t irqbase, uint32_t irqmask)
    450 {
    451 	struct acpi_pci_intr * const pi = (struct acpi_pci_intr *)pic;
    452 
    453 	pi->pi_unblocked |= irqmask;
    454 }
    455 
    456 static void
    457 acpi_pci_md_block_irqs(struct pic_softc *pic, size_t irqbase, uint32_t irqmask)
    458 {
    459 	struct acpi_pci_intr * const pi = (struct acpi_pci_intr *)pic;
    460 
    461 	pi->pi_unblocked &= ~irqmask;
    462 }
    463 
    464 static int
    465 acpi_pci_md_find_pending_irqs(struct pic_softc *pic)
    466 {
    467 	struct acpi_pci_intr * const pi = (struct acpi_pci_intr *)pic;
    468 
    469 	pic_mark_pending_sources(pic, 0, pi->pi_unblocked);
    470 
    471 	return 1;
    472 }
    473 
    474 static void
    475 acpi_pci_md_establish_irq(struct pic_softc *pic, struct intrsource *is)
    476 {
    477 }
    478 
    479 static void
    480 acpi_pci_md_source_name(struct pic_softc *pic, int irq, char *buf, size_t len)
    481 {
    482 	snprintf(buf, len, "slot %d", irq);
    483 }
    484 
    485 static struct pic_ops acpi_pci_pic_ops = {
    486 	.pic_unblock_irqs = acpi_pci_md_unblock_irqs,
    487 	.pic_block_irqs = acpi_pci_md_block_irqs,
    488 	.pic_find_pending_irqs = acpi_pci_md_find_pending_irqs,
    489 	.pic_establish_irq = acpi_pci_md_establish_irq,
    490 	.pic_source_name = acpi_pci_md_source_name,
    491 };
    492 
    493 static void *
    494 acpi_pci_md_intr_establish(void *v, pci_intr_handle_t ih, int ipl,
    495     int (*callback)(void *), void *arg, const char *xname)
    496 {
    497 	struct acpi_pci_context * const ap = v;
    498 	struct acpi_pci_intr *pi;
    499 	int slot;
    500 
    501 	if ((ih & (ARM_PCI_INTR_MSI | ARM_PCI_INTR_MSIX)) != 0)
    502 		return arm_pci_msi_intr_establish(&ap->ap_pc, ih, ipl, callback, arg, xname);
    503 
    504 	const int irq = (int)__SHIFTOUT(ih, ARM_PCI_INTR_IRQ);
    505 	const int mpsafe = (ih & ARM_PCI_INTR_MPSAFE) ? IST_MPSAFE : 0;
    506 
    507 	pi = acpi_pci_md_intr_lookup(irq);
    508 	if (pi == NULL) {
    509 		pi = kmem_zalloc(sizeof(*pi), KM_SLEEP);
    510 		pi->pi_irq = irq;
    511 		snprintf(pi->pi_pic.pic_name, sizeof(pi->pi_pic.pic_name),
    512 		    "PCI irq %d", irq);
    513 		pi->pi_pic.pic_maxsources = 32;
    514 		pi->pi_pic.pic_ops = &acpi_pci_pic_ops;
    515 		pi->pi_irqbase = pic_add(&pi->pi_pic, PIC_IRQBASE_ALLOC);
    516 		TAILQ_INSERT_TAIL(&acpi_pci_intrs, pi, pi_list);
    517 		pi->pi_ih = intr_establish_xname(irq, IPL_SCHED, IST_LEVEL | IST_MPSAFE,
    518 		    pic_handle_intr, &pi->pi_pic, device_xname(ap->ap_dev));
    519 	}
    520 	if (pi->pi_ih == NULL)
    521 		return NULL;
    522 
    523 	/* Find a free slot */
    524 	for (slot = 0; slot < pi->pi_pic.pic_maxsources; slot++)
    525 		if (pi->pi_pic.pic_sources[slot] == NULL)
    526 			break;
    527 	if (slot == pi->pi_pic.pic_maxsources)
    528 		return NULL;
    529 
    530 	return intr_establish_xname(pi->pi_irqbase + slot, ipl, IST_LEVEL | mpsafe,
    531 	    callback, arg, xname);
    532 }
    533 
    534 static void
    535 acpi_pci_md_intr_disestablish(void *v, void *vih)
    536 {
    537 	intr_disestablish(vih);
    538 }
    539 
    540 const struct acpi_pci_quirk *
    541 acpi_pci_md_find_quirk(int seg)
    542 {
    543 	ACPI_STATUS rv;
    544 	ACPI_TABLE_MCFG *mcfg;
    545 	u_int n;
    546 
    547 	rv = AcpiGetTable(ACPI_SIG_MCFG, 0, (ACPI_TABLE_HEADER **)&mcfg);
    548 	if (ACPI_FAILURE(rv))
    549 		return NULL;
    550 
    551 	for (n = 0; n < __arraycount(acpi_pci_quirks); n++) {
    552 		const struct acpi_pci_quirk *q = &acpi_pci_quirks[n];
    553 		if (memcmp(q->q_oemid, mcfg->Header.OemId, ACPI_OEM_ID_SIZE) == 0 &&
    554 		    memcmp(q->q_oemtableid, mcfg->Header.OemTableId, ACPI_OEM_TABLE_ID_SIZE) == 0 &&
    555 		    q->q_oemrevision == mcfg->Header.OemRevision &&
    556 		    (q->q_segment == -1 || q->q_segment == seg))
    557 			return q;
    558 	}
    559 
    560 	return NULL;
    561 }
    562 
    563 pci_chipset_tag_t
    564 acpi_pci_md_get_chipset_tag(struct acpi_softc *sc, int seg, int bbn)
    565 {
    566 	struct acpi_pci_pct *pct = NULL, *pctp;
    567 	const struct acpi_pci_quirk *q;
    568 
    569 	TAILQ_FOREACH(pctp, &acpi_pci_chipset_tags, pct_list)
    570 		if (pctp->pct_ap.ap_seg == seg) {
    571 			pct = pctp;
    572 			break;
    573 		}
    574 
    575 	if (pct == NULL) {
    576 		pct = kmem_zalloc(sizeof(*pct), KM_SLEEP);
    577 		pct->pct_ap.ap_dev = sc->sc_dev;
    578 		pct->pct_ap.ap_pc = arm_acpi_pci_chipset;
    579 		pct->pct_ap.ap_pc.pc_conf_v = &pct->pct_ap;
    580 		pct->pct_ap.ap_pc.pc_intr_v = &pct->pct_ap;
    581 		pct->pct_ap.ap_seg = seg;
    582 		pct->pct_ap.ap_bus = bbn;
    583 		pct->pct_ap.ap_bst = acpi_softc->sc_memt;
    584 
    585 		q = acpi_pci_md_find_quirk(seg);
    586 		if (q != NULL)
    587 			q->q_init(&pct->pct_ap);
    588 
    589 		TAILQ_INSERT_TAIL(&acpi_pci_chipset_tags, pct, pct_list);
    590 	}
    591 
    592 	return &pct->pct_ap.ap_pc;
    593 }
    594 __strong_alias(acpi_get_pci_chipset_tag,acpi_pci_md_get_chipset_tag);
    595