xref: /freebsd/sys/x86/x86/msi.c (revision 535af610)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 2006 Yahoo!, Inc.
5  * All rights reserved.
6  * Written by: John Baldwin <jhb@FreeBSD.org>
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the author nor the names of any co-contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 /*
34  * Support for PCI Message Signalled Interrupts (MSI).  MSI interrupts on
35  * x86 are basically APIC messages that the northbridge delivers directly
36  * to the local APICs as if they had come from an I/O APIC.
37  */
38 
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
41 
42 #include "opt_acpi.h"
43 #include "opt_iommu.h"
44 
45 #include <sys/param.h>
46 #include <sys/bus.h>
47 #include <sys/kernel.h>
48 #include <sys/limits.h>
49 #include <sys/lock.h>
50 #include <sys/malloc.h>
51 #include <sys/mutex.h>
52 #include <sys/sx.h>
53 #include <sys/sysctl.h>
54 #include <sys/systm.h>
55 #include <x86/apicreg.h>
56 #include <machine/cputypes.h>
57 #include <machine/md_var.h>
58 #include <machine/frame.h>
59 #include <machine/intr_machdep.h>
60 #include <x86/apicvar.h>
61 #include <x86/iommu/iommu_intrmap.h>
62 #include <machine/specialreg.h>
63 #include <dev/pci/pcivar.h>
64 
65 /* Fields in address for Intel MSI messages. */
66 #define	MSI_INTEL_ADDR_DEST		0x000ff000
67 #define	MSI_INTEL_ADDR_RH		0x00000008
68 # define MSI_INTEL_ADDR_RH_ON		0x00000008
69 # define MSI_INTEL_ADDR_RH_OFF		0x00000000
70 #define	MSI_INTEL_ADDR_DM		0x00000004
71 # define MSI_INTEL_ADDR_DM_PHYSICAL	0x00000000
72 # define MSI_INTEL_ADDR_DM_LOGICAL	0x00000004
73 
74 /* Fields in data for Intel MSI messages. */
75 #define	MSI_INTEL_DATA_TRGRMOD		IOART_TRGRMOD	/* Trigger mode. */
76 # define MSI_INTEL_DATA_TRGREDG		IOART_TRGREDG
77 # define MSI_INTEL_DATA_TRGRLVL		IOART_TRGRLVL
78 #define	MSI_INTEL_DATA_LEVEL		0x00004000	/* Polarity. */
79 # define MSI_INTEL_DATA_DEASSERT	0x00000000
80 # define MSI_INTEL_DATA_ASSERT		0x00004000
81 #define	MSI_INTEL_DATA_DELMOD		IOART_DELMOD	/* Delivery mode. */
82 # define MSI_INTEL_DATA_DELFIXED	IOART_DELFIXED
83 # define MSI_INTEL_DATA_DELLOPRI	IOART_DELLOPRI
84 # define MSI_INTEL_DATA_DELSMI		IOART_DELSMI
85 # define MSI_INTEL_DATA_DELNMI		IOART_DELNMI
86 # define MSI_INTEL_DATA_DELINIT		IOART_DELINIT
87 # define MSI_INTEL_DATA_DELEXINT	IOART_DELEXINT
88 #define	MSI_INTEL_DATA_INTVEC		IOART_INTVEC	/* Interrupt vector. */
89 
90 /*
91  * Build Intel MSI message and data values from a source.  AMD64 systems
92  * seem to be compatible, so we use the same function for both.
93  */
94 #define	INTEL_ADDR(msi)							\
95 	(MSI_INTEL_ADDR_BASE | (msi)->msi_cpu << 12 |			\
96 	    MSI_INTEL_ADDR_RH_OFF | MSI_INTEL_ADDR_DM_PHYSICAL)
97 #define	INTEL_DATA(msi)							\
98 	(MSI_INTEL_DATA_TRGREDG | MSI_INTEL_DATA_DELFIXED | (msi)->msi_vector)
99 
100 static MALLOC_DEFINE(M_MSI, "msi", "PCI MSI");
101 
102 /*
103  * MSI sources are bunched into groups.  This is because MSI forces
104  * all of the messages to share the address and data registers and
105  * thus certain properties (such as the local APIC ID target on x86).
106  * Each group has a 'first' source that contains information global to
107  * the group.  These fields are marked with (g) below.
108  *
109  * Note that local APIC ID is kind of special.  Each message will be
110  * assigned an ID by the system; however, a group will use the ID from
111  * the first message.
112  *
113  * For MSI-X, each message is isolated.
114  */
115 struct msi_intsrc {
116 	struct intsrc msi_intsrc;
117 	device_t msi_dev;		/* Owning device. (g) */
118 	struct msi_intsrc *msi_first;	/* First source in group. */
119 	u_int msi_irq;			/* IRQ cookie. */
120 	u_int msi_msix;			/* MSI-X message. */
121 	u_int msi_vector:8;		/* IDT vector. */
122 	u_int msi_cpu;			/* Local APIC ID. (g) */
123 	u_int msi_count:8;		/* Messages in this group. (g) */
124 	u_int msi_maxcount:8;		/* Alignment for this group. (g) */
125 	u_int *msi_irqs;		/* Group's IRQ list. (g) */
126 	u_int msi_remap_cookie;
127 };
128 
129 static void	msi_create_source(void);
130 static void	msi_enable_source(struct intsrc *isrc);
131 static void	msi_disable_source(struct intsrc *isrc, int eoi);
132 static void	msi_eoi_source(struct intsrc *isrc);
133 static void	msi_enable_intr(struct intsrc *isrc);
134 static void	msi_disable_intr(struct intsrc *isrc);
135 static int	msi_vector(struct intsrc *isrc);
136 static int	msi_source_pending(struct intsrc *isrc);
137 static int	msi_config_intr(struct intsrc *isrc, enum intr_trigger trig,
138 		    enum intr_polarity pol);
139 static int	msi_assign_cpu(struct intsrc *isrc, u_int apic_id);
140 
141 struct pic msi_pic = {
142 	.pic_enable_source = msi_enable_source,
143 	.pic_disable_source = msi_disable_source,
144 	.pic_eoi_source = msi_eoi_source,
145 	.pic_enable_intr = msi_enable_intr,
146 	.pic_disable_intr = msi_disable_intr,
147 	.pic_vector = msi_vector,
148 	.pic_source_pending = msi_source_pending,
149 	.pic_suspend = NULL,
150 	.pic_resume = NULL,
151 	.pic_config_intr = msi_config_intr,
152 	.pic_assign_cpu = msi_assign_cpu,
153 	.pic_reprogram_pin = NULL,
154 };
155 
156 u_int first_msi_irq;
157 SYSCTL_UINT(_machdep, OID_AUTO, first_msi_irq, CTLFLAG_RD, &first_msi_irq, 0,
158     "Number of first IRQ reserved for MSI and MSI-X interrupts");
159 
160 u_int num_msi_irqs = 2048;
161 SYSCTL_UINT(_machdep, OID_AUTO, num_msi_irqs, CTLFLAG_RDTUN, &num_msi_irqs, 0,
162     "Number of IRQs reserved for MSI and MSI-X interrupts");
163 
164 #ifdef SMP
165 /**
166  * Xen hypervisors prior to 4.6.0 do not properly handle updates to
167  * enabled MSI-X table entries.  Allow migration of MSI-X interrupts
168  * to be disabled via a tunable. Values have the following meaning:
169  *
170  * -1: automatic detection by FreeBSD
171  *  0: enable migration
172  *  1: disable migration
173  */
174 int msix_disable_migration = -1;
175 SYSCTL_INT(_machdep, OID_AUTO, disable_msix_migration, CTLFLAG_RDTUN,
176     &msix_disable_migration, 0,
177     "Disable migration of MSI-X interrupts between CPUs");
178 #endif
179 
180 static int msi_enabled;
181 static u_int msi_last_irq;
182 static struct mtx msi_lock;
183 
184 static void
185 msi_enable_source(struct intsrc *isrc)
186 {
187 }
188 
189 static void
190 msi_disable_source(struct intsrc *isrc, int eoi)
191 {
192 
193 	if (eoi == PIC_EOI)
194 		lapic_eoi();
195 }
196 
197 static void
198 msi_eoi_source(struct intsrc *isrc)
199 {
200 
201 	lapic_eoi();
202 }
203 
204 static void
205 msi_enable_intr(struct intsrc *isrc)
206 {
207 	struct msi_intsrc *msi = (struct msi_intsrc *)isrc;
208 
209 	apic_enable_vector(msi->msi_cpu, msi->msi_vector);
210 }
211 
212 static void
213 msi_disable_intr(struct intsrc *isrc)
214 {
215 	struct msi_intsrc *msi = (struct msi_intsrc *)isrc;
216 
217 	apic_disable_vector(msi->msi_cpu, msi->msi_vector);
218 }
219 
220 static int
221 msi_vector(struct intsrc *isrc)
222 {
223 	struct msi_intsrc *msi = (struct msi_intsrc *)isrc;
224 
225 	return (msi->msi_irq);
226 }
227 
228 static int
229 msi_source_pending(struct intsrc *isrc)
230 {
231 
232 	return (0);
233 }
234 
235 static int
236 msi_config_intr(struct intsrc *isrc, enum intr_trigger trig,
237     enum intr_polarity pol)
238 {
239 
240 	return (ENODEV);
241 }
242 
243 static int
244 msi_assign_cpu(struct intsrc *isrc, u_int apic_id)
245 {
246 	struct msi_intsrc *sib, *msi = (struct msi_intsrc *)isrc;
247 	int old_vector;
248 	u_int old_id;
249 	int i, vector;
250 
251 	/*
252 	 * Only allow CPUs to be assigned to the first message for an
253 	 * MSI group.
254 	 */
255 	if (msi->msi_first != msi)
256 		return (EINVAL);
257 
258 #ifdef SMP
259 	if (msix_disable_migration && msi->msi_msix)
260 		return (EINVAL);
261 #endif
262 
263 	/* Store information to free existing irq. */
264 	old_vector = msi->msi_vector;
265 	old_id = msi->msi_cpu;
266 	if (old_id == apic_id)
267 		return (0);
268 
269 	/* Allocate IDT vectors on this cpu. */
270 	if (msi->msi_count > 1) {
271 		KASSERT(msi->msi_msix == 0, ("MSI-X message group"));
272 		vector = apic_alloc_vectors(apic_id, msi->msi_irqs,
273 		    msi->msi_count, msi->msi_maxcount);
274 	} else
275 		vector = apic_alloc_vector(apic_id, msi->msi_irq);
276 	if (vector == 0)
277 		return (ENOSPC);
278 
279 	msi->msi_cpu = apic_id;
280 	msi->msi_vector = vector;
281 	if (msi->msi_intsrc.is_handlers > 0)
282 		apic_enable_vector(msi->msi_cpu, msi->msi_vector);
283 	if (bootverbose)
284 		printf("msi: Assigning %s IRQ %d to local APIC %u vector %u\n",
285 		    msi->msi_msix ? "MSI-X" : "MSI", msi->msi_irq,
286 		    msi->msi_cpu, msi->msi_vector);
287 	for (i = 1; i < msi->msi_count; i++) {
288 		sib = (struct msi_intsrc *)intr_lookup_source(msi->msi_irqs[i]);
289 		sib->msi_cpu = apic_id;
290 		sib->msi_vector = vector + i;
291 		if (sib->msi_intsrc.is_handlers > 0)
292 			apic_enable_vector(sib->msi_cpu, sib->msi_vector);
293 		if (bootverbose)
294 			printf(
295 		    "msi: Assigning MSI IRQ %d to local APIC %u vector %u\n",
296 			    sib->msi_irq, sib->msi_cpu, sib->msi_vector);
297 	}
298 	BUS_REMAP_INTR(device_get_parent(msi->msi_dev), msi->msi_dev,
299 	    msi->msi_irq);
300 
301 	/*
302 	 * Free the old vector after the new one is established.  This is done
303 	 * to prevent races where we could miss an interrupt.
304 	 */
305 	if (msi->msi_intsrc.is_handlers > 0)
306 		apic_disable_vector(old_id, old_vector);
307 	apic_free_vector(old_id, old_vector, msi->msi_irq);
308 	for (i = 1; i < msi->msi_count; i++) {
309 		sib = (struct msi_intsrc *)intr_lookup_source(msi->msi_irqs[i]);
310 		if (sib->msi_intsrc.is_handlers > 0)
311 			apic_disable_vector(old_id, old_vector + i);
312 		apic_free_vector(old_id, old_vector + i, msi->msi_irqs[i]);
313 	}
314 	return (0);
315 }
316 
317 void
318 msi_init(void)
319 {
320 
321 	/* Check if we have a supported CPU. */
322 	switch (cpu_vendor_id) {
323 	case CPU_VENDOR_INTEL:
324 	case CPU_VENDOR_AMD:
325 	case CPU_VENDOR_HYGON:
326 		break;
327 	case CPU_VENDOR_CENTAUR:
328 		if (CPUID_TO_FAMILY(cpu_id) == 0x6 &&
329 		    CPUID_TO_MODEL(cpu_id) >= 0xf)
330 			break;
331 		/* FALLTHROUGH */
332 	default:
333 		return;
334 	}
335 
336 #ifdef SMP
337 	if (msix_disable_migration == -1) {
338 		/* The default is to allow migration of MSI-X interrupts. */
339 		msix_disable_migration = 0;
340 	}
341 #endif
342 
343 	if (num_msi_irqs == 0)
344 		return;
345 
346 	first_msi_irq = num_io_irqs;
347 	if (num_msi_irqs > UINT_MAX - first_msi_irq)
348 		panic("num_msi_irqs too high");
349 	num_io_irqs = first_msi_irq + num_msi_irqs;
350 
351 	msi_enabled = 1;
352 	intr_register_pic(&msi_pic);
353 	mtx_init(&msi_lock, "msi", NULL, MTX_DEF);
354 }
355 
356 static void
357 msi_create_source(void)
358 {
359 	struct msi_intsrc *msi;
360 	u_int irq;
361 
362 	mtx_lock(&msi_lock);
363 	if (msi_last_irq >= num_msi_irqs) {
364 		mtx_unlock(&msi_lock);
365 		return;
366 	}
367 	irq = msi_last_irq + first_msi_irq;
368 	msi_last_irq++;
369 	mtx_unlock(&msi_lock);
370 
371 	msi = malloc(sizeof(struct msi_intsrc), M_MSI, M_WAITOK | M_ZERO);
372 	msi->msi_intsrc.is_pic = &msi_pic;
373 	msi->msi_irq = irq;
374 	intr_register_source(&msi->msi_intsrc);
375 	nexus_add_irq(irq);
376 }
377 
378 /*
379  * Try to allocate 'count' interrupt sources with contiguous IDT values.
380  */
381 int
382 msi_alloc(device_t dev, int count, int maxcount, int *irqs)
383 {
384 	struct msi_intsrc *msi, *fsrc;
385 	u_int cpu, domain, *mirqs;
386 	int cnt, i, vector;
387 #ifdef IOMMU
388 	u_int cookies[count];
389 	int error;
390 #endif
391 
392 	if (!msi_enabled)
393 		return (ENXIO);
394 
395 	if (bus_get_domain(dev, &domain) != 0)
396 		domain = 0;
397 
398 	if (count > 1)
399 		mirqs = malloc(count * sizeof(*mirqs), M_MSI, M_WAITOK);
400 	else
401 		mirqs = NULL;
402 again:
403 	mtx_lock(&msi_lock);
404 
405 	/* Try to find 'count' free IRQs. */
406 	cnt = 0;
407 	for (i = first_msi_irq; i < first_msi_irq + num_msi_irqs; i++) {
408 		msi = (struct msi_intsrc *)intr_lookup_source(i);
409 
410 		/* End of allocated sources, so break. */
411 		if (msi == NULL)
412 			break;
413 
414 		/* If this is a free one, save its IRQ in the array. */
415 		if (msi->msi_dev == NULL) {
416 			irqs[cnt] = i;
417 			cnt++;
418 			if (cnt == count)
419 				break;
420 		}
421 	}
422 
423 	/* Do we need to create some new sources? */
424 	if (cnt < count) {
425 		/* If we would exceed the max, give up. */
426 		if (i + (count - cnt) > first_msi_irq + num_msi_irqs) {
427 			mtx_unlock(&msi_lock);
428 			free(mirqs, M_MSI);
429 			return (ENXIO);
430 		}
431 		mtx_unlock(&msi_lock);
432 
433 		/* We need count - cnt more sources. */
434 		while (cnt < count) {
435 			msi_create_source();
436 			cnt++;
437 		}
438 		goto again;
439 	}
440 
441 	/* Ok, we now have the IRQs allocated. */
442 	KASSERT(cnt == count, ("count mismatch"));
443 
444 	/* Allocate 'count' IDT vectors. */
445 	cpu = intr_next_cpu(domain);
446 	vector = apic_alloc_vectors(cpu, irqs, count, maxcount);
447 	if (vector == 0) {
448 		mtx_unlock(&msi_lock);
449 		free(mirqs, M_MSI);
450 		return (ENOSPC);
451 	}
452 
453 #ifdef IOMMU
454 	mtx_unlock(&msi_lock);
455 	error = iommu_alloc_msi_intr(dev, cookies, count);
456 	mtx_lock(&msi_lock);
457 	if (error == EOPNOTSUPP)
458 		error = 0;
459 	if (error != 0) {
460 		for (i = 0; i < count; i++)
461 			apic_free_vector(cpu, vector + i, irqs[i]);
462 		free(mirqs, M_MSI);
463 		return (error);
464 	}
465 	for (i = 0; i < count; i++) {
466 		msi = (struct msi_intsrc *)intr_lookup_source(irqs[i]);
467 		msi->msi_remap_cookie = cookies[i];
468 	}
469 #endif
470 
471 	/* Assign IDT vectors and make these messages owned by 'dev'. */
472 	fsrc = (struct msi_intsrc *)intr_lookup_source(irqs[0]);
473 	for (i = 0; i < count; i++) {
474 		msi = (struct msi_intsrc *)intr_lookup_source(irqs[i]);
475 		msi->msi_cpu = cpu;
476 		msi->msi_dev = dev;
477 		msi->msi_vector = vector + i;
478 		if (bootverbose)
479 			printf(
480 		    "msi: routing MSI IRQ %d to local APIC %u vector %u\n",
481 			    msi->msi_irq, msi->msi_cpu, msi->msi_vector);
482 		msi->msi_first = fsrc;
483 		KASSERT(msi->msi_intsrc.is_handlers == 0,
484 		    ("dead MSI has handlers"));
485 	}
486 	fsrc->msi_count = count;
487 	fsrc->msi_maxcount = maxcount;
488 	if (count > 1)
489 		bcopy(irqs, mirqs, count * sizeof(*mirqs));
490 	fsrc->msi_irqs = mirqs;
491 	mtx_unlock(&msi_lock);
492 	return (0);
493 }
494 
495 int
496 msi_release(int *irqs, int count)
497 {
498 	struct msi_intsrc *msi, *first;
499 	int i;
500 
501 	mtx_lock(&msi_lock);
502 	first = (struct msi_intsrc *)intr_lookup_source(irqs[0]);
503 	if (first == NULL) {
504 		mtx_unlock(&msi_lock);
505 		return (ENOENT);
506 	}
507 
508 	/* Make sure this isn't an MSI-X message. */
509 	if (first->msi_msix) {
510 		mtx_unlock(&msi_lock);
511 		return (EINVAL);
512 	}
513 
514 	/* Make sure this message is allocated to a group. */
515 	if (first->msi_first == NULL) {
516 		mtx_unlock(&msi_lock);
517 		return (ENXIO);
518 	}
519 
520 	/*
521 	 * Make sure this is the start of a group and that we are releasing
522 	 * the entire group.
523 	 */
524 	if (first->msi_first != first || first->msi_count != count) {
525 		mtx_unlock(&msi_lock);
526 		return (EINVAL);
527 	}
528 	KASSERT(first->msi_dev != NULL, ("unowned group"));
529 
530 	/* Clear all the extra messages in the group. */
531 	for (i = 1; i < count; i++) {
532 		msi = (struct msi_intsrc *)intr_lookup_source(irqs[i]);
533 		KASSERT(msi->msi_first == first, ("message not in group"));
534 		KASSERT(msi->msi_dev == first->msi_dev, ("owner mismatch"));
535 #ifdef IOMMU
536 		iommu_unmap_msi_intr(first->msi_dev, msi->msi_remap_cookie);
537 #endif
538 		msi->msi_first = NULL;
539 		msi->msi_dev = NULL;
540 		apic_free_vector(msi->msi_cpu, msi->msi_vector, msi->msi_irq);
541 		msi->msi_vector = 0;
542 	}
543 
544 	/* Clear out the first message. */
545 #ifdef IOMMU
546 	mtx_unlock(&msi_lock);
547 	iommu_unmap_msi_intr(first->msi_dev, first->msi_remap_cookie);
548 	mtx_lock(&msi_lock);
549 #endif
550 	first->msi_first = NULL;
551 	first->msi_dev = NULL;
552 	apic_free_vector(first->msi_cpu, first->msi_vector, first->msi_irq);
553 	first->msi_vector = 0;
554 	first->msi_count = 0;
555 	first->msi_maxcount = 0;
556 	free(first->msi_irqs, M_MSI);
557 	first->msi_irqs = NULL;
558 
559 	mtx_unlock(&msi_lock);
560 	return (0);
561 }
562 
563 int
564 msi_map(int irq, uint64_t *addr, uint32_t *data)
565 {
566 	struct msi_intsrc *msi;
567 	int error;
568 #ifdef IOMMU
569 	struct msi_intsrc *msi1;
570 	int i, k;
571 #endif
572 
573 	mtx_lock(&msi_lock);
574 	msi = (struct msi_intsrc *)intr_lookup_source(irq);
575 	if (msi == NULL) {
576 		mtx_unlock(&msi_lock);
577 		return (ENOENT);
578 	}
579 
580 	/* Make sure this message is allocated to a device. */
581 	if (msi->msi_dev == NULL) {
582 		mtx_unlock(&msi_lock);
583 		return (ENXIO);
584 	}
585 
586 	/*
587 	 * If this message isn't an MSI-X message, make sure it's part
588 	 * of a group, and switch to the first message in the
589 	 * group.
590 	 */
591 	if (!msi->msi_msix) {
592 		if (msi->msi_first == NULL) {
593 			mtx_unlock(&msi_lock);
594 			return (ENXIO);
595 		}
596 		msi = msi->msi_first;
597 	}
598 
599 #ifdef IOMMU
600 	if (!msi->msi_msix) {
601 		for (k = msi->msi_count - 1, i = first_msi_irq; k > 0 &&
602 		    i < first_msi_irq + num_msi_irqs; i++) {
603 			if (i == msi->msi_irq)
604 				continue;
605 			msi1 = (struct msi_intsrc *)intr_lookup_source(i);
606 			if (!msi1->msi_msix && msi1->msi_first == msi) {
607 				mtx_unlock(&msi_lock);
608 				iommu_map_msi_intr(msi1->msi_dev,
609 				    msi1->msi_cpu, msi1->msi_vector,
610 				    msi1->msi_remap_cookie, NULL, NULL);
611 				k--;
612 				mtx_lock(&msi_lock);
613 			}
614 		}
615 	}
616 	mtx_unlock(&msi_lock);
617 	error = iommu_map_msi_intr(msi->msi_dev, msi->msi_cpu,
618 	    msi->msi_vector, msi->msi_remap_cookie, addr, data);
619 #else
620 	mtx_unlock(&msi_lock);
621 	error = EOPNOTSUPP;
622 #endif
623 	if (error == EOPNOTSUPP && msi->msi_cpu > 0xff) {
624 		printf("%s: unsupported destination APIC ID %u\n", __func__,
625 		    msi->msi_cpu);
626 		error = EINVAL;
627 	}
628 	if (error == EOPNOTSUPP) {
629 		*addr = INTEL_ADDR(msi);
630 		*data = INTEL_DATA(msi);
631 		error = 0;
632 	}
633 	return (error);
634 }
635 
636 int
637 msix_alloc(device_t dev, int *irq)
638 {
639 	struct msi_intsrc *msi;
640 	u_int cpu, domain;
641 	int i, vector;
642 #ifdef IOMMU
643 	u_int cookie;
644 	int error;
645 #endif
646 
647 	if (!msi_enabled)
648 		return (ENXIO);
649 
650 	if (bus_get_domain(dev, &domain) != 0)
651 		domain = 0;
652 
653 again:
654 	mtx_lock(&msi_lock);
655 
656 	/* Find a free IRQ. */
657 	for (i = first_msi_irq; i < first_msi_irq + num_msi_irqs; i++) {
658 		msi = (struct msi_intsrc *)intr_lookup_source(i);
659 
660 		/* End of allocated sources, so break. */
661 		if (msi == NULL)
662 			break;
663 
664 		/* Stop at the first free source. */
665 		if (msi->msi_dev == NULL)
666 			break;
667 	}
668 
669 	/* Are all IRQs in use? */
670 	if (i == first_msi_irq + num_msi_irqs) {
671 		mtx_unlock(&msi_lock);
672 		return (ENXIO);
673 	}
674 
675 	/* Do we need to create a new source? */
676 	if (msi == NULL) {
677 		mtx_unlock(&msi_lock);
678 
679 		/* Create a new source. */
680 		msi_create_source();
681 		goto again;
682 	}
683 
684 	/* Allocate an IDT vector. */
685 	cpu = intr_next_cpu(domain);
686 	vector = apic_alloc_vector(cpu, i);
687 	if (vector == 0) {
688 		mtx_unlock(&msi_lock);
689 		return (ENOSPC);
690 	}
691 
692 	msi->msi_dev = dev;
693 #ifdef IOMMU
694 	mtx_unlock(&msi_lock);
695 	error = iommu_alloc_msi_intr(dev, &cookie, 1);
696 	mtx_lock(&msi_lock);
697 	if (error == EOPNOTSUPP)
698 		error = 0;
699 	if (error != 0) {
700 		msi->msi_dev = NULL;
701 		apic_free_vector(cpu, vector, i);
702 		return (error);
703 	}
704 	msi->msi_remap_cookie = cookie;
705 #endif
706 
707 	if (bootverbose)
708 		printf("msi: routing MSI-X IRQ %d to local APIC %u vector %u\n",
709 		    msi->msi_irq, cpu, vector);
710 
711 	/* Setup source. */
712 	msi->msi_cpu = cpu;
713 	msi->msi_first = msi;
714 	msi->msi_vector = vector;
715 	msi->msi_msix = 1;
716 	msi->msi_count = 1;
717 	msi->msi_maxcount = 1;
718 	msi->msi_irqs = NULL;
719 
720 	KASSERT(msi->msi_intsrc.is_handlers == 0, ("dead MSI-X has handlers"));
721 	mtx_unlock(&msi_lock);
722 
723 	*irq = i;
724 	return (0);
725 }
726 
727 int
728 msix_release(int irq)
729 {
730 	struct msi_intsrc *msi;
731 
732 	mtx_lock(&msi_lock);
733 	msi = (struct msi_intsrc *)intr_lookup_source(irq);
734 	if (msi == NULL) {
735 		mtx_unlock(&msi_lock);
736 		return (ENOENT);
737 	}
738 
739 	/* Make sure this is an MSI-X message. */
740 	if (!msi->msi_msix) {
741 		mtx_unlock(&msi_lock);
742 		return (EINVAL);
743 	}
744 
745 	KASSERT(msi->msi_dev != NULL, ("unowned message"));
746 
747 	/* Clear out the message. */
748 #ifdef IOMMU
749 	mtx_unlock(&msi_lock);
750 	iommu_unmap_msi_intr(msi->msi_dev, msi->msi_remap_cookie);
751 	mtx_lock(&msi_lock);
752 #endif
753 	msi->msi_first = NULL;
754 	msi->msi_dev = NULL;
755 	apic_free_vector(msi->msi_cpu, msi->msi_vector, msi->msi_irq);
756 	msi->msi_vector = 0;
757 	msi->msi_msix = 0;
758 	msi->msi_count = 0;
759 	msi->msi_maxcount = 0;
760 
761 	mtx_unlock(&msi_lock);
762 	return (0);
763 }
764