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pci_intr_machdep.c revision 1.45
      1 /*	$NetBSD: pci_intr_machdep.c,v 1.45 2018/09/23 02:51:06 cherry Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1997, 1998, 2009 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
      9  * NASA Ames Research Center.
     10  *
     11  * Redistribution and use in source and binary forms, with or without
     12  * modification, are permitted provided that the following conditions
     13  * are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions and the following disclaimer.
     16  * 2. Redistributions in binary form must reproduce the above copyright
     17  *    notice, this list of conditions and the following disclaimer in the
     18  *    documentation and/or other materials provided with the distribution.
     19  *
     20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     30  * POSSIBILITY OF SUCH DAMAGE.
     31  */
     32 
     33 /*
     34  * Copyright (c) 1996 Christopher G. Demetriou.  All rights reserved.
     35  * Copyright (c) 1994 Charles M. Hannum.  All rights reserved.
     36  *
     37  * Redistribution and use in source and binary forms, with or without
     38  * modification, are permitted provided that the following conditions
     39  * are met:
     40  * 1. Redistributions of source code must retain the above copyright
     41  *    notice, this list of conditions and the following disclaimer.
     42  * 2. Redistributions in binary form must reproduce the above copyright
     43  *    notice, this list of conditions and the following disclaimer in the
     44  *    documentation and/or other materials provided with the distribution.
     45  * 3. All advertising materials mentioning features or use of this software
     46  *    must display the following acknowledgement:
     47  *	This product includes software developed by Charles M. Hannum.
     48  * 4. The name of the author may not be used to endorse or promote products
     49  *    derived from this software without specific prior written permission.
     50  *
     51  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     52  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     53  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     54  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     55  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     56  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     57  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     58  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     59  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     60  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     61  */
     62 
     63 /*
     64  * Machine-specific functions for PCI autoconfiguration.
     65  *
     66  * On PCs, there are two methods of generating PCI configuration cycles.
     67  * We try to detect the appropriate mechanism for this machine and set
     68  * up a few function pointers to access the correct method directly.
     69  *
     70  * The configuration method can be hard-coded in the config file by
     71  * using `options PCI_CONF_MODE=N', where `N' is the configuration mode
     72  * as defined section 3.6.4.1, `Generating Configuration Cycles'.
     73  */
     74 
     75 #include <sys/cdefs.h>
     76 __KERNEL_RCSID(0, "$NetBSD: pci_intr_machdep.c,v 1.45 2018/09/23 02:51:06 cherry Exp $");
     77 
     78 #include <sys/types.h>
     79 #include <sys/param.h>
     80 #include <sys/time.h>
     81 #include <sys/systm.h>
     82 #include <sys/cpu.h>
     83 #include <sys/errno.h>
     84 #include <sys/device.h>
     85 #include <sys/intr.h>
     86 #include <sys/kmem.h>
     87 
     88 #include <dev/pci/pcivar.h>
     89 
     90 #include "ioapic.h"
     91 #include "eisa.h"
     92 #include "acpica.h"
     93 #include "opt_mpbios.h"
     94 #include "opt_acpi.h"
     95 
     96 #include <machine/i82489reg.h>
     97 
     98 #if NIOAPIC > 0 || NACPICA > 0
     99 #include <machine/i82093reg.h>
    100 #include <machine/i82093var.h>
    101 #include <machine/mpconfig.h>
    102 #include <machine/mpbiosvar.h>
    103 #include <machine/pic.h>
    104 #include <x86/pci/pci_msi_machdep.h>
    105 #endif
    106 
    107 #ifdef MPBIOS
    108 #include <machine/mpbiosvar.h>
    109 #endif
    110 
    111 #if NACPICA > 0
    112 #include <machine/mpacpi.h>
    113 #endif
    114 
    115 int
    116 pci_intr_map(const struct pci_attach_args *pa, pci_intr_handle_t *ihp)
    117 {
    118 	pci_intr_pin_t pin = pa->pa_intrpin;
    119 	pci_intr_line_t line = pa->pa_intrline;
    120 	pci_chipset_tag_t ipc, pc = pa->pa_pc;
    121 #if NIOAPIC > 0 || NACPICA > 0
    122 	pci_intr_pin_t rawpin = pa->pa_rawintrpin;
    123 	int bus, dev, func;
    124 #endif
    125 
    126 	for (ipc = pc; ipc != NULL; ipc = ipc->pc_super) {
    127 		if ((ipc->pc_present & PCI_OVERRIDE_INTR_MAP) == 0)
    128 			continue;
    129 		return (*ipc->pc_ov->ov_intr_map)(ipc->pc_ctx, pa, ihp);
    130 	}
    131 
    132 	if (pin == 0) {
    133 		/* No IRQ used. */
    134 		goto bad;
    135 	}
    136 
    137 	*ihp = 0;
    138 
    139 	if (pin > PCI_INTERRUPT_PIN_MAX) {
    140 		aprint_normal("pci_intr_map: bad interrupt pin %d\n", pin);
    141 		goto bad;
    142 	}
    143 
    144 #if NIOAPIC > 0 || NACPICA > 0
    145 	KASSERT(rawpin >= PCI_INTERRUPT_PIN_A);
    146 	KASSERT(rawpin <= PCI_INTERRUPT_PIN_D);
    147 	pci_decompose_tag(pc, pa->pa_tag, &bus, &dev, &func);
    148 	if (mp_busses != NULL) {
    149 		/*
    150 		 * Note: PCI_INTERRUPT_PIN_A == 1 where intr_find_mpmapping
    151 		 * wants pci bus_pin encoding which uses INT_A == 0.
    152 		 */
    153 		if (intr_find_mpmapping(bus,
    154 		    (dev << 2) | (rawpin - PCI_INTERRUPT_PIN_A), ihp) == 0) {
    155 			if (APIC_IRQ_LEGACY_IRQ(*ihp) == 0)
    156 				*ihp |= line;
    157 			return 0;
    158 		}
    159 		/*
    160 		 * No explicit PCI mapping found. This is not fatal,
    161 		 * we'll try the ISA (or possibly EISA) mappings next.
    162 		 */
    163 	}
    164 #endif
    165 
    166 	/*
    167 	 * Section 6.2.4, `Miscellaneous Functions', says that 255 means
    168 	 * `unknown' or `no connection' on a PC.  We assume that a device with
    169 	 * `no connection' either doesn't have an interrupt (in which case the
    170 	 * pin number should be 0, and would have been noticed above), or
    171 	 * wasn't configured by the BIOS (in which case we punt, since there's
    172 	 * no real way we can know how the interrupt lines are mapped in the
    173 	 * hardware).
    174 	 *
    175 	 * XXX
    176 	 * Since IRQ 0 is only used by the clock, and we can't actually be sure
    177 	 * that the BIOS did its job, we also recognize that as meaning that
    178 	 * the BIOS has not configured the device.
    179 	 */
    180 	if (line == 0 || line == X86_PCI_INTERRUPT_LINE_NO_CONNECTION) {
    181 		aprint_normal("pci_intr_map: no mapping for pin %c (line=%02x)\n",
    182 		       '@' + pin, line);
    183 		goto bad;
    184 	} else {
    185 		if (line >= NUM_LEGACY_IRQS) {
    186 			aprint_normal("pci_intr_map: bad interrupt line %d\n", line);
    187 			goto bad;
    188 		}
    189 		if (line == 2) {
    190 			aprint_normal("pci_intr_map: changed line 2 to line 9\n");
    191 			line = 9;
    192 		}
    193 	}
    194 #if NIOAPIC > 0 || NACPICA > 0
    195 	if (mp_busses != NULL) {
    196 		if (intr_find_mpmapping(mp_isa_bus, line, ihp) == 0) {
    197 			if ((*ihp & 0xff) == 0)
    198 				*ihp |= line;
    199 			return 0;
    200 		}
    201 #if NEISA > 0
    202 		if (intr_find_mpmapping(mp_eisa_bus, line, ihp) == 0) {
    203 			if ((*ihp & 0xff) == 0)
    204 				*ihp |= line;
    205 			return 0;
    206 		}
    207 #endif
    208 		aprint_normal("pci_intr_map: bus %d dev %d func %d pin %d; line %d\n",
    209 		    bus, dev, func, pin, line);
    210 		aprint_normal("pci_intr_map: no MP mapping found\n");
    211 	}
    212 #endif
    213 
    214 	*ihp = line;
    215 	return 0;
    216 
    217 bad:
    218 	*ihp = -1;
    219 	return 1;
    220 }
    221 
    222 const char *
    223 pci_intr_string(pci_chipset_tag_t pc, pci_intr_handle_t ih, char *buf,
    224     size_t len)
    225 {
    226 	pci_chipset_tag_t ipc;
    227 
    228 	for (ipc = pc; ipc != NULL; ipc = ipc->pc_super) {
    229 		if ((ipc->pc_present & PCI_OVERRIDE_INTR_STRING) == 0)
    230 			continue;
    231 		return (*ipc->pc_ov->ov_intr_string)(ipc->pc_ctx, pc, ih,
    232 		    buf, len);
    233 	}
    234 
    235 	if (INT_VIA_MSI(ih))
    236 		return x86_pci_msi_string(pc, ih, buf, len);
    237 
    238 	return intr_string(ih & ~MPSAFE_MASK, buf, len);
    239 }
    240 
    241 
    242 const struct evcnt *
    243 pci_intr_evcnt(pci_chipset_tag_t pc, pci_intr_handle_t ih)
    244 {
    245 	pci_chipset_tag_t ipc;
    246 
    247 	for (ipc = pc; ipc != NULL; ipc = ipc->pc_super) {
    248 		if ((ipc->pc_present & PCI_OVERRIDE_INTR_EVCNT) == 0)
    249 			continue;
    250 		return (*ipc->pc_ov->ov_intr_evcnt)(ipc->pc_ctx, pc, ih);
    251 	}
    252 
    253 	/* XXX for now, no evcnt parent reported */
    254 	return NULL;
    255 }
    256 
    257 int
    258 pci_intr_setattr(pci_chipset_tag_t pc, pci_intr_handle_t *ih,
    259 		 int attr, uint64_t data)
    260 {
    261 
    262 	switch (attr) {
    263 	case PCI_INTR_MPSAFE:
    264 		if (data) {
    265 			 *ih |= MPSAFE_MASK;
    266 		} else {
    267 			 *ih &= ~MPSAFE_MASK;
    268 		}
    269 		/* XXX Set live if already mapped. */
    270 		return 0;
    271 	default:
    272 		return ENODEV;
    273 	}
    274 }
    275 
    276 static int
    277 pci_intr_find_intx_irq(pci_intr_handle_t ih, int *irq, struct pic **pic,
    278     int *pin)
    279 {
    280 
    281 	KASSERT(irq != NULL);
    282 	KASSERT(pic != NULL);
    283 	KASSERT(pin != NULL);
    284 
    285 	*pic = &i8259_pic;
    286 	*pin = *irq = APIC_IRQ_LEGACY_IRQ(ih);
    287 
    288 #if NIOAPIC > 0
    289 	if (ih & APIC_INT_VIA_APIC) {
    290 		struct ioapic_softc *ioapic;
    291 
    292 		ioapic = ioapic_find(APIC_IRQ_APIC(ih));
    293 		if (ioapic == NULL)
    294 			return ENOENT;
    295 		*pic = &ioapic->sc_pic;
    296 		*pin = APIC_IRQ_PIN(ih);
    297 		*irq = APIC_IRQ_LEGACY_IRQ(ih);
    298 		if (*irq < 0 || *irq >= NUM_LEGACY_IRQS)
    299 			*irq = -1;
    300 	}
    301 #endif
    302 
    303 	return 0;
    304 }
    305 
    306 static void *
    307 pci_intr_establish_xname_internal(pci_chipset_tag_t pc, pci_intr_handle_t ih,
    308     int level, int (*func)(void *), void *arg, const char *xname)
    309 {
    310 	int pin, irq;
    311 	struct pic *pic;
    312 	bool mpsafe;
    313 	pci_chipset_tag_t ipc;
    314 
    315 	for (ipc = pc; ipc != NULL; ipc = ipc->pc_super) {
    316 		if ((ipc->pc_present & PCI_OVERRIDE_INTR_ESTABLISH) == 0)
    317 			continue;
    318 		return (*ipc->pc_ov->ov_intr_establish)(ipc->pc_ctx,
    319 		    pc, ih, level, func, arg);
    320 	}
    321 
    322 	if (INT_VIA_MSI(ih)) {
    323 		if (MSI_INT_IS_MSIX(ih))
    324 			return x86_pci_msix_establish(pc, ih, level, func, arg,
    325 			    xname);
    326 		else
    327 			return x86_pci_msi_establish(pc, ih, level, func, arg,
    328 			    xname);
    329 	}
    330 
    331 	if (pci_intr_find_intx_irq(ih, &irq, &pic, &pin)) {
    332 		aprint_normal("%s: bad pic %d\n", __func__,
    333 		    APIC_IRQ_APIC(ih));
    334 		return NULL;
    335 	}
    336 
    337 	mpsafe = ((ih & MPSAFE_MASK) != 0);
    338 
    339 	return intr_establish_xname(irq, pic, pin, IST_LEVEL, level, func, arg,
    340 	    mpsafe, xname);
    341 }
    342 
    343 void *
    344 pci_intr_establish(pci_chipset_tag_t pc, pci_intr_handle_t ih,
    345     int level, int (*func)(void *), void *arg)
    346 {
    347 
    348 	return pci_intr_establish_xname_internal(pc, ih, level, func, arg, "unknown");
    349 }
    350 
    351 void *
    352 pci_intr_establish_xname(pci_chipset_tag_t pc, pci_intr_handle_t ih,
    353     int level, int (*func)(void *), void *arg, const char *xname)
    354 {
    355 
    356 	return pci_intr_establish_xname_internal(pc, ih, level, func, arg, xname);
    357 }
    358 
    359 
    360 void
    361 pci_intr_disestablish(pci_chipset_tag_t pc, void *cookie)
    362 {
    363 	pci_chipset_tag_t ipc;
    364 
    365 	for (ipc = pc; ipc != NULL; ipc = ipc->pc_super) {
    366 		if ((ipc->pc_present & PCI_OVERRIDE_INTR_DISESTABLISH) == 0)
    367 			continue;
    368 		(*ipc->pc_ov->ov_intr_disestablish)(ipc->pc_ctx, pc, cookie);
    369 		return;
    370 	}
    371 
    372 	/* MSI/MSI-X processing is switched in intr_disestablish(). */
    373 	intr_disestablish(cookie);
    374 }
    375 
    376 #if NIOAPIC > 0
    377 #ifdef __HAVE_PCI_MSI_MSIX
    378 pci_intr_type_t
    379 pci_intr_type(pci_chipset_tag_t pc, pci_intr_handle_t ih)
    380 {
    381 
    382 	if (INT_VIA_MSI(ih)) {
    383 		if (MSI_INT_IS_MSIX(ih))
    384 			return PCI_INTR_TYPE_MSIX;
    385 		else
    386 			return PCI_INTR_TYPE_MSI;
    387 	} else {
    388 		return PCI_INTR_TYPE_INTX;
    389 	}
    390 }
    391 
    392 static const char *
    393 x86_pci_intx_create_intrid(pci_chipset_tag_t pc, pci_intr_handle_t ih, char *buf,
    394     size_t len)
    395 {
    396 #if !defined(XEN)
    397 	int pin, irq;
    398 	struct pic *pic;
    399 
    400 	KASSERT(!INT_VIA_MSI(ih));
    401 
    402 	pic = &i8259_pic;
    403 	pin = irq = APIC_IRQ_LEGACY_IRQ(ih);
    404 
    405 	if (pci_intr_find_intx_irq(ih, &irq, &pic, &pin)) {
    406 		aprint_normal("%s: bad pic %d\n", __func__,
    407 		    APIC_IRQ_APIC(ih));
    408 		return NULL;
    409 	}
    410 
    411 	return intr_create_intrid(irq, pic, pin, buf, len);
    412 #else
    413 	return pci_intr_string(pc, ih, buf, len);
    414 #endif /* !XEN */
    415 }
    416 
    417 static void
    418 x86_pci_intx_release(pci_chipset_tag_t pc, pci_intr_handle_t *pih)
    419 {
    420 	char intrstr_buf[INTRIDBUF];
    421 	const char *intrstr;
    422 
    423 	intrstr = pci_intr_string(NULL, *pih, intrstr_buf, sizeof(intrstr_buf));
    424 	mutex_enter(&cpu_lock);
    425 	intr_free_io_intrsource(intrstr);
    426 	mutex_exit(&cpu_lock);
    427 
    428 	kmem_free(pih, sizeof(*pih));
    429 }
    430 
    431 int
    432 pci_intx_alloc(const struct pci_attach_args *pa, pci_intr_handle_t **pih)
    433 {
    434 	struct intrsource *isp;
    435 	pci_intr_handle_t *handle;
    436 	int error;
    437 	char intrstr_buf[INTRIDBUF];
    438 	const char *intrstr;
    439 
    440 	handle = kmem_zalloc(sizeof(*handle), KM_SLEEP);
    441 	if (pci_intr_map(pa, handle) != 0) {
    442 		aprint_normal("cannot set up pci_intr_handle_t\n");
    443 		error = EINVAL;
    444 		goto error;
    445 	}
    446 
    447 	/*
    448 	 * must be the same intrstr as intr_establish_xname()
    449 	 */
    450 	intrstr = x86_pci_intx_create_intrid(pa->pa_pc, *handle, intrstr_buf,
    451 	    sizeof(intrstr_buf));
    452 	mutex_enter(&cpu_lock);
    453 	isp = intr_allocate_io_intrsource(intrstr);
    454 	mutex_exit(&cpu_lock);
    455 	if (isp == NULL) {
    456 		aprint_normal("can't allocate io_intersource\n");
    457 		error = ENOMEM;
    458 		goto error;
    459 	}
    460 
    461 	*pih = handle;
    462 	return 0;
    463 
    464 error:
    465 	kmem_free(handle, sizeof(*handle));
    466 	return error;
    467 }
    468 
    469 /*
    470  * Interrupt handler allocation utility. This function calls each allocation
    471  * function as specified by arguments.
    472  * Currently callee functions are pci_intx_alloc(), pci_msi_alloc_exact(),
    473  * and pci_msix_alloc_exact().
    474  * pa       : pci_attach_args
    475  * ihps     : interrupt handlers
    476  * counts   : The array of number of required interrupt handlers.
    477  *            It is overwritten by allocated the number of handlers.
    478  *            CAUTION: The size of counts[] must be PCI_INTR_TYPE_SIZE.
    479  * max_type : "max" type of using interrupts. See below.
    480  *     e.g.
    481  *         If you want to use 5 MSI-X, 1 MSI, or INTx, you use "counts" as
    482  *             int counts[PCI_INTR_TYPE_SIZE];
    483  *             counts[PCI_INTR_TYPE_MSIX] = 5;
    484  *             counts[PCI_INTR_TYPE_MSI] = 1;
    485  *             counts[PCI_INTR_TYPE_INTX] = 1;
    486  *             error = pci_intr_alloc(pa, ihps, counts, PCI_INTR_TYPE_MSIX);
    487  *
    488  *         If you want to use hardware max number MSI-X or 1 MSI,
    489  *         and not to use INTx, you use "counts" as
    490  *             int counts[PCI_INTR_TYPE_SIZE];
    491  *             counts[PCI_INTR_TYPE_MSIX] = -1;
    492  *             counts[PCI_INTR_TYPE_MSI] = 1;
    493  *             counts[PCI_INTR_TYPE_INTX] = 0;
    494  *             error = pci_intr_alloc(pa, ihps, counts, PCI_INTR_TYPE_MSIX);
    495  *
    496  *         If you want to use 3 MSI or INTx, you can use "counts" as
    497  *             int counts[PCI_INTR_TYPE_SIZE];
    498  *             counts[PCI_INTR_TYPE_MSI] = 3;
    499  *             counts[PCI_INTR_TYPE_INTX] = 1;
    500  *             error = pci_intr_alloc(pa, ihps, counts, PCI_INTR_TYPE_MSI);
    501  *
    502  *         If you want to use 1 MSI or INTx (probably most general usage),
    503  *         you can simply use this API like
    504  *         below
    505  *             error = pci_intr_alloc(pa, ihps, NULL, 0);
    506  *                                                    ^ ignored
    507  */
    508 int
    509 pci_intr_alloc(const struct pci_attach_args *pa, pci_intr_handle_t **ihps,
    510     int *counts, pci_intr_type_t max_type)
    511 {
    512 	int error;
    513 	int intx_count, msi_count, msix_count;
    514 
    515 	intx_count = msi_count = msix_count = 0;
    516 	if (counts == NULL) { /* simple pattern */
    517 		msi_count = 1;
    518 		intx_count = 1;
    519 	} else {
    520 		switch(max_type) {
    521 		case PCI_INTR_TYPE_MSIX:
    522 			msix_count = counts[PCI_INTR_TYPE_MSIX];
    523 			/* FALLTHROUGH */
    524 		case PCI_INTR_TYPE_MSI:
    525 			msi_count = counts[PCI_INTR_TYPE_MSI];
    526 			/* FALLTHROUGH */
    527 		case PCI_INTR_TYPE_INTX:
    528 			intx_count = counts[PCI_INTR_TYPE_INTX];
    529 			break;
    530 		default:
    531 			return EINVAL;
    532 		}
    533 	}
    534 
    535 	if (counts != NULL)
    536 		memset(counts, 0, sizeof(counts[0]) * PCI_INTR_TYPE_SIZE);
    537 	error = EINVAL;
    538 
    539 	/* try MSI-X */
    540 	if (msix_count == -1) /* use hardware max */
    541 		msix_count = pci_msix_count(pa->pa_pc, pa->pa_tag);
    542 	if (msix_count > 0) {
    543 		error = pci_msix_alloc_exact(pa, ihps, msix_count);
    544 		if (error == 0) {
    545 			KASSERTMSG(counts != NULL,
    546 			    "If MSI-X is used, counts must not be NULL.");
    547 			counts[PCI_INTR_TYPE_MSIX] = msix_count;
    548 			goto out;
    549 		}
    550 	}
    551 
    552 	/* try MSI */
    553 	if (msi_count == -1) /* use hardware max */
    554 		msi_count = pci_msi_count(pa->pa_pc, pa->pa_tag);
    555 	if (msi_count > 0) {
    556 		error = pci_msi_alloc_exact(pa, ihps, msi_count);
    557 		if (error == 0) {
    558 			if (counts != NULL)
    559 				counts[PCI_INTR_TYPE_MSI] = msi_count;
    560 			goto out;
    561 		}
    562 	}
    563 
    564 	/* try INTx */
    565 	if (intx_count != 0) { /* The number of INTx is always 1. */
    566 		error = pci_intx_alloc(pa, ihps);
    567 		if (error == 0) {
    568 			if (counts != NULL)
    569 				counts[PCI_INTR_TYPE_INTX] = 1;
    570 		}
    571 	}
    572 
    573  out:
    574 	return error;
    575 }
    576 
    577 void
    578 pci_intr_release(pci_chipset_tag_t pc, pci_intr_handle_t *pih, int count)
    579 {
    580 	if (pih == NULL)
    581 		return;
    582 
    583 	if (INT_VIA_MSI(*pih)) {
    584 		if (MSI_INT_IS_MSIX(*pih))
    585 			return x86_pci_msix_release(pc, pih, count);
    586 		else
    587 			return x86_pci_msi_release(pc, pih, count);
    588 	} else {
    589 		KASSERT(count == 1);
    590 		return x86_pci_intx_release(pc, pih);
    591 	}
    592 
    593 }
    594 #endif /* __HAVE_PCI_MSI_MSIX */
    595 #endif /*  NIOAPIC > 0 */
    596