xref: /freebsd/sys/dev/vmd/vmd.c (revision 397e83df75e0fcd0d3fcb95ae4d794cb7600fc89)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2021 Alexander Motin <mav@FreeBSD.org>
5  * Copyright 2019 Cisco Systems, Inc.
6  * All rights reserved.
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  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/types.h>
31 #include <sys/param.h>
32 #include <sys/bus.h>
33 #include <sys/conf.h>
34 #include <sys/kernel.h>
35 #include <sys/limits.h>
36 #include <sys/module.h>
37 #include <sys/sysctl.h>
38 #include <sys/systm.h>
39 #include <sys/malloc.h>
40 
41 #include <machine/bus.h>
42 #include <machine/resource.h>
43 #include <machine/intr_machdep.h>
44 #include <sys/rman.h>
45 #include <sys/lock.h>
46 #include <sys/mutex.h>
47 
48 #include <sys/pciio.h>
49 #include <dev/pci/pcivar.h>
50 #include <dev/pci/pcireg.h>
51 #include <dev/pci/pci_private.h>
52 #include <dev/pci/pcib_private.h>
53 
54 #include <dev/vmd/vmd.h>
55 
56 #include "pcib_if.h"
57 
58 struct vmd_type {
59 	u_int16_t	vmd_vid;
60 	u_int16_t	vmd_did;
61 	char		*vmd_name;
62 	int		flags;
63 #define BUS_RESTRICT	1
64 #define VECTOR_OFFSET	2
65 #define CAN_BYPASS_MSI	4
66 };
67 
68 #define VMD_CAP		0x40
69 #define VMD_BUS_RESTRICT	0x1
70 
71 #define VMD_CONFIG	0x44
72 #define VMD_BYPASS_MSI		0x2
73 #define VMD_BUS_START(x)	((x >> 8) & 0x3)
74 
75 #define VMD_LOCK	0x70
76 
77 SYSCTL_NODE(_hw, OID_AUTO, vmd, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
78     "Intel Volume Management Device tuning parameters");
79 
80 /*
81  * By default all VMD devices remap children MSI/MSI-X interrupts into their
82  * own.  It creates additional isolation, but also complicates things due to
83  * sharing, etc.  Fortunately some VMD devices can bypass the remapping.
84  */
85 static int vmd_bypass_msi = 1;
86 SYSCTL_INT(_hw_vmd, OID_AUTO, bypass_msi, CTLFLAG_RWTUN, &vmd_bypass_msi, 0,
87     "Bypass MSI remapping on capable hardware");
88 
89 /*
90  * All MSIs within a group share address, so VMD can't distinguish them.
91  * It makes no sense to use more than one per device, only if required by
92  * some specific device drivers.
93  */
94 static int vmd_max_msi = 1;
95 SYSCTL_INT(_hw_vmd, OID_AUTO, max_msi, CTLFLAG_RWTUN, &vmd_max_msi, 0,
96     "Maximum number of MSI vectors per device");
97 
98 /*
99  * MSI-X can use different addresses, but we have limited number of MSI-X
100  * we can route to, so use conservative default to try to avoid sharing.
101  */
102 static int vmd_max_msix = 3;
103 SYSCTL_INT(_hw_vmd, OID_AUTO, max_msix, CTLFLAG_RWTUN, &vmd_max_msix, 0,
104     "Maximum number of MSI-X vectors per device");
105 
106 static struct vmd_type vmd_devs[] = {
107         { 0x8086, 0x201d, "Intel Volume Management Device", 0 },
108         { 0x8086, 0x28c0, "Intel Volume Management Device", BUS_RESTRICT | CAN_BYPASS_MSI },
109         { 0x8086, 0x467f, "Intel Volume Management Device", BUS_RESTRICT | VECTOR_OFFSET },
110         { 0x8086, 0x4c3d, "Intel Volume Management Device", BUS_RESTRICT | VECTOR_OFFSET },
111         { 0x8086, 0x7d0b, "Intel Volume Management Device", BUS_RESTRICT | VECTOR_OFFSET },
112         { 0x8086, 0x9a0b, "Intel Volume Management Device", BUS_RESTRICT | VECTOR_OFFSET },
113         { 0x8086, 0xa77f, "Intel Volume Management Device", BUS_RESTRICT | VECTOR_OFFSET },
114         { 0x8086, 0xad0b, "Intel Volume Management Device", BUS_RESTRICT | VECTOR_OFFSET },
115         { 0, 0, NULL, 0 }
116 };
117 
118 static int
119 vmd_probe(device_t dev)
120 {
121 	struct vmd_type *t;
122 	uint16_t vid, did;
123 
124 	vid = pci_get_vendor(dev);
125 	did = pci_get_device(dev);
126 	for (t = vmd_devs; t->vmd_name != NULL; t++) {
127 		if (vid == t->vmd_vid && did == t->vmd_did) {
128 			device_set_desc(dev, t->vmd_name);
129 			return (BUS_PROBE_DEFAULT);
130 		}
131 	}
132 	return (ENXIO);
133 }
134 
135 static void
136 vmd_free(struct vmd_softc *sc)
137 {
138 	struct vmd_irq *vi;
139 	struct vmd_irq_user *u;
140 	int i;
141 
142 	if (sc->psc.bus.rman.rm_end != 0)
143 		rman_fini(&sc->psc.bus.rman);
144 	if (sc->psc.mem.rman.rm_end != 0)
145 		rman_fini(&sc->psc.mem.rman);
146 	while ((u = LIST_FIRST(&sc->vmd_users)) != NULL) {
147 		LIST_REMOVE(u, viu_link);
148 		free(u, M_DEVBUF);
149 	}
150 	if (sc->vmd_irq != NULL) {
151 		for (i = 0; i < sc->vmd_msix_count; i++) {
152 			vi = &sc->vmd_irq[i];
153 			if (vi->vi_res == NULL)
154 				continue;
155 			bus_teardown_intr(sc->psc.dev, vi->vi_res,
156 			    vi->vi_handle);
157 			bus_release_resource(sc->psc.dev, SYS_RES_IRQ,
158 			    vi->vi_rid, vi->vi_res);
159 		}
160 	}
161 	free(sc->vmd_irq, M_DEVBUF);
162 	sc->vmd_irq = NULL;
163 	pci_release_msi(sc->psc.dev);
164 	for (i = 0; i < VMD_MAX_BAR; i++) {
165 		if (sc->vmd_regs_res[i] != NULL)
166 			bus_release_resource(sc->psc.dev, SYS_RES_MEMORY,
167 			    sc->vmd_regs_rid[i], sc->vmd_regs_res[i]);
168 	}
169 }
170 
171 /* Hidden PCI Roots are hidden in BAR(0). */
172 
173 static uint32_t
174 vmd_read_config(device_t dev, u_int b, u_int s, u_int f, u_int reg, int width)
175 {
176 	struct vmd_softc *sc;
177 	bus_addr_t offset;
178 
179 	sc = device_get_softc(dev);
180 	if (b < sc->vmd_bus_start || b > sc->vmd_bus_end)
181 		return (0xffffffff);
182 
183 	offset = ((b - sc->vmd_bus_start) << 20) + (s << 15) + (f << 12) + reg;
184 
185 	switch (width) {
186 	case 4:
187 		return (bus_read_4(sc->vmd_regs_res[0], offset));
188 	case 2:
189 		return (bus_read_2(sc->vmd_regs_res[0], offset));
190 	case 1:
191 		return (bus_read_1(sc->vmd_regs_res[0], offset));
192 	default:
193 		__assert_unreachable();
194 		return (0xffffffff);
195 	}
196 }
197 
198 static void
199 vmd_write_config(device_t dev, u_int b, u_int s, u_int f, u_int reg,
200     uint32_t val, int width)
201 {
202 	struct vmd_softc *sc;
203 	bus_addr_t offset;
204 
205 	sc = device_get_softc(dev);
206 	if (b < sc->vmd_bus_start || b > sc->vmd_bus_end)
207 		return;
208 
209 	offset = ((b - sc->vmd_bus_start) << 20) + (s << 15) + (f << 12) + reg;
210 
211 	switch (width) {
212 	case 4:
213 		return (bus_write_4(sc->vmd_regs_res[0], offset, val));
214 	case 2:
215 		return (bus_write_2(sc->vmd_regs_res[0], offset, val));
216 	case 1:
217 		return (bus_write_1(sc->vmd_regs_res[0], offset, val));
218 	default:
219 		__assert_unreachable();
220 	}
221 }
222 
223 static void
224 vmd_set_msi_bypass(device_t dev, bool enable)
225 {
226 	uint16_t val;
227 
228 	val = pci_read_config(dev, VMD_CONFIG, 2);
229 	if (enable)
230 		val |= VMD_BYPASS_MSI;
231 	else
232 		val &= ~VMD_BYPASS_MSI;
233 	pci_write_config(dev, VMD_CONFIG, val, 2);
234 }
235 
236 static int
237 vmd_intr(void *arg)
238 {
239 	/*
240 	 * We have nothing to do here, but we have to register some interrupt
241 	 * handler to make PCI code setup and enable the MSI-X vector.
242 	 */
243 	return (FILTER_STRAY);
244 }
245 
246 static int
247 vmd_attach(device_t dev)
248 {
249 	struct vmd_softc *sc;
250 	struct pcib_secbus *bus;
251 	struct pcib_window *w;
252 	struct vmd_type *t;
253 	struct vmd_irq *vi;
254 	uint16_t vid, did;
255 	uint32_t bar;
256 	int i, j, error;
257 	char buf[64];
258 
259 	sc = device_get_softc(dev);
260 	bzero(sc, sizeof(*sc));
261 	sc->psc.dev = dev;
262 	sc->psc.domain = PCI_DOMAINMAX - device_get_unit(dev);
263 
264 	pci_enable_busmaster(dev);
265 
266 	for (i = 0, j = 0; i < VMD_MAX_BAR; i++, j++) {
267 		sc->vmd_regs_rid[i] = PCIR_BAR(j);
268 		bar = pci_read_config(dev, PCIR_BAR(0), 4);
269 		if (PCI_BAR_MEM(bar) && (bar & PCIM_BAR_MEM_TYPE) ==
270 		    PCIM_BAR_MEM_64)
271 			j++;
272 		if ((sc->vmd_regs_res[i] = bus_alloc_resource_any(dev,
273 		    SYS_RES_MEMORY, &sc->vmd_regs_rid[i], RF_ACTIVE)) == NULL) {
274 			device_printf(dev, "Cannot allocate resources\n");
275 			goto fail;
276 		}
277 	}
278 
279 	vid = pci_get_vendor(dev);
280 	did = pci_get_device(dev);
281 	for (t = vmd_devs; t->vmd_name != NULL; t++) {
282 		if (vid == t->vmd_vid && did == t->vmd_did)
283 			break;
284 	}
285 
286 	sc->vmd_bus_start = 0;
287 	if ((t->flags & BUS_RESTRICT) &&
288 	    (pci_read_config(dev, VMD_CAP, 2) & VMD_BUS_RESTRICT)) {
289 		switch (VMD_BUS_START(pci_read_config(dev, VMD_CONFIG, 2))) {
290 		case 0:
291 			sc->vmd_bus_start = 0;
292 			break;
293 		case 1:
294 			sc->vmd_bus_start = 128;
295 			break;
296 		case 2:
297 			sc->vmd_bus_start = 224;
298 			break;
299 		default:
300 			device_printf(dev, "Unknown bus offset\n");
301 			goto fail;
302 		}
303 	}
304 	sc->vmd_bus_end = MIN(PCI_BUSMAX, sc->vmd_bus_start +
305 	    (rman_get_size(sc->vmd_regs_res[0]) >> 20) - 1);
306 
307 	bus = &sc->psc.bus;
308 	bus->sec = sc->vmd_bus_start;
309 	bus->sub = sc->vmd_bus_end;
310 	bus->dev = dev;
311 	bus->rman.rm_start = 0;
312 	bus->rman.rm_end = PCI_BUSMAX;
313 	bus->rman.rm_type = RMAN_ARRAY;
314 	snprintf(buf, sizeof(buf), "%s bus numbers", device_get_nameunit(dev));
315 	bus->rman.rm_descr = strdup(buf, M_DEVBUF);
316 	error = rman_init(&bus->rman);
317 	if (error) {
318 		device_printf(dev, "Failed to initialize bus rman\n");
319 		bus->rman.rm_end = 0;
320 		goto fail;
321 	}
322 	error = rman_manage_region(&bus->rman, sc->vmd_bus_start,
323 	    sc->vmd_bus_end);
324 	if (error) {
325 		device_printf(dev, "Failed to add resource to bus rman\n");
326 		goto fail;
327 	}
328 
329 	w = &sc->psc.mem;
330 	w->rman.rm_type = RMAN_ARRAY;
331 	snprintf(buf, sizeof(buf), "%s memory window", device_get_nameunit(dev));
332 	w->rman.rm_descr = strdup(buf, M_DEVBUF);
333 	error = rman_init(&w->rman);
334 	if (error) {
335 		device_printf(dev, "Failed to initialize memory rman\n");
336 		w->rman.rm_end = 0;
337 		goto fail;
338 	}
339 	error = rman_manage_region(&w->rman,
340 	    rman_get_start(sc->vmd_regs_res[1]),
341 	    rman_get_end(sc->vmd_regs_res[1]));
342 	if (error) {
343 		device_printf(dev, "Failed to add resource to memory rman\n");
344 		goto fail;
345 	}
346 	error = rman_manage_region(&w->rman,
347 	    rman_get_start(sc->vmd_regs_res[2]) + 0x2000,
348 	    rman_get_end(sc->vmd_regs_res[2]));
349 	if (error) {
350 		device_printf(dev, "Failed to add resource to memory rman\n");
351 		goto fail;
352 	}
353 
354 	LIST_INIT(&sc->vmd_users);
355 	sc->vmd_fist_vector = (t->flags & VECTOR_OFFSET) ? 1 : 0;
356 	sc->vmd_msix_count = pci_msix_count(dev);
357 	if (vmd_bypass_msi && (t->flags & CAN_BYPASS_MSI)) {
358 		sc->vmd_msix_count = 0;
359 		vmd_set_msi_bypass(dev, true);
360 	} else if (pci_alloc_msix(dev, &sc->vmd_msix_count) == 0) {
361 		sc->vmd_irq = malloc(sizeof(struct vmd_irq) *
362 		    sc->vmd_msix_count, M_DEVBUF, M_WAITOK | M_ZERO);
363 		for (i = 0; i < sc->vmd_msix_count; i++) {
364 			vi = &sc->vmd_irq[i];
365 			vi->vi_rid = i + 1;
366 			vi->vi_res = bus_alloc_resource_any(dev, SYS_RES_IRQ,
367 			    &vi->vi_rid, RF_ACTIVE | RF_SHAREABLE);
368 			if (vi->vi_res == NULL) {
369 				device_printf(dev, "Failed to allocate irq\n");
370 				goto fail;
371 			}
372 			vi->vi_irq = rman_get_start(vi->vi_res);
373 			if (bus_setup_intr(dev, vi->vi_res, INTR_TYPE_MISC |
374 			    INTR_MPSAFE, vmd_intr, NULL, vi, &vi->vi_handle)) {
375 				device_printf(dev, "Can't set up interrupt\n");
376 				bus_release_resource(dev, SYS_RES_IRQ,
377 				    vi->vi_rid, vi->vi_res);
378 				vi->vi_res = NULL;
379 				goto fail;
380 			}
381 		}
382 		vmd_set_msi_bypass(dev, false);
383 	}
384 
385 	sc->vmd_dma_tag = bus_get_dma_tag(dev);
386 
387 	sc->psc.child = device_add_child(dev, "pci", -1);
388 	return (bus_generic_attach(dev));
389 
390 fail:
391 	vmd_free(sc);
392 	return (ENXIO);
393 }
394 
395 static int
396 vmd_detach(device_t dev)
397 {
398 	struct vmd_softc *sc = device_get_softc(dev);
399 	int error;
400 
401 	error = bus_generic_detach(dev);
402 	if (error)
403 		return (error);
404 	error = device_delete_children(dev);
405 	if (error)
406 		return (error);
407 	if (sc->vmd_msix_count == 0)
408 		vmd_set_msi_bypass(dev, false);
409 	vmd_free(sc);
410 	return (0);
411 }
412 
413 static bus_dma_tag_t
414 vmd_get_dma_tag(device_t dev, device_t child)
415 {
416 	struct vmd_softc *sc = device_get_softc(dev);
417 
418 	return (sc->vmd_dma_tag);
419 }
420 
421 static struct rman *
422 vmd_get_rman(device_t dev, int type, u_int flags)
423 {
424 	struct vmd_softc *sc = device_get_softc(dev);
425 
426 	switch (type) {
427 	case SYS_RES_MEMORY:
428 		return (&sc->psc.mem.rman);
429 	case PCI_RES_BUS:
430 		return (&sc->psc.bus.rman);
431 	default:
432 		/* VMD hardware does not support I/O ports. */
433 		return (NULL);
434 	}
435 }
436 
437 static struct resource *
438 vmd_alloc_resource(device_t dev, device_t child, int type, int *rid,
439     rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
440 {
441 	struct resource *res;
442 
443 	if (type == SYS_RES_IRQ) {
444 		/* VMD hardware does not support legacy interrupts. */
445 		if (*rid == 0)
446 			return (NULL);
447 		return (bus_generic_alloc_resource(dev, child, type, rid,
448 		    start, end, count, flags | RF_SHAREABLE));
449 	}
450 	res = bus_generic_rman_alloc_resource(dev, child, type, rid, start,
451 	    end, count, flags);
452 	if (bootverbose && res != NULL) {
453 		switch (type) {
454 		case SYS_RES_MEMORY:
455 			device_printf(dev,
456 			    "allocated memory range (%#jx-%#jx) for rid %d of %s\n",
457 			    rman_get_start(res), rman_get_end(res), *rid,
458 			    pcib_child_name(child));
459 			break;
460 		case PCI_RES_BUS:
461 			device_printf(dev,
462 			    "allocated bus range (%ju-%ju) for rid %d of %s\n",
463 			    rman_get_start(res), rman_get_end(res), *rid,
464 			    pcib_child_name(child));
465 			break;
466 		}
467 	}
468 	return (res);
469 }
470 
471 static int
472 vmd_adjust_resource(device_t dev, device_t child,
473     struct resource *r, rman_res_t start, rman_res_t end)
474 {
475 
476 	if (rman_get_type(r) == SYS_RES_IRQ) {
477 		return (bus_generic_adjust_resource(dev, child, r, start, end));
478 	}
479 	return (bus_generic_rman_adjust_resource(dev, child, r, start, end));
480 }
481 
482 static int
483 vmd_release_resource(device_t dev, device_t child, struct resource *r)
484 {
485 
486 	if (rman_get_type(r) == SYS_RES_IRQ) {
487 		return (bus_generic_release_resource(dev, child, r));
488 	}
489 	return (bus_generic_rman_release_resource(dev, child, r));
490 }
491 
492 static int
493 vmd_activate_resource(device_t dev, device_t child, struct resource *r)
494 {
495 	if (rman_get_type(r) == SYS_RES_IRQ) {
496 		return (bus_generic_activate_resource(dev, child, r));
497 	}
498 	return (bus_generic_rman_activate_resource(dev, child, r));
499 }
500 
501 static int
502 vmd_deactivate_resource(device_t dev, device_t child, struct resource *r)
503 {
504 	if (rman_get_type(r) == SYS_RES_IRQ) {
505 		return (bus_generic_deactivate_resource(dev, child, r));
506 	}
507 	return (bus_generic_rman_deactivate_resource(dev, child, r));
508 }
509 
510 static struct resource *
511 vmd_find_parent_resource(struct vmd_softc *sc, struct resource *r)
512 {
513 	for (int i = 1; i < 3; i++) {
514 		if (rman_get_start(sc->vmd_regs_res[i]) <= rman_get_start(r) &&
515 		    rman_get_end(sc->vmd_regs_res[i]) >= rman_get_end(r))
516 			return (sc->vmd_regs_res[i]);
517 	}
518 	return (NULL);
519 }
520 
521 static int
522 vmd_map_resource(device_t dev, device_t child, struct resource *r,
523     struct resource_map_request *argsp, struct resource_map *map)
524 {
525 	struct vmd_softc *sc = device_get_softc(dev);
526 	struct resource_map_request args;
527 	struct resource *pres;
528 	rman_res_t length, start;
529 	int error;
530 
531 	/* Resources must be active to be mapped. */
532 	if (!(rman_get_flags(r) & RF_ACTIVE))
533 		return (ENXIO);
534 
535 	resource_init_map_request(&args);
536 	error = resource_validate_map_request(r, argsp, &args, &start, &length);
537 	if (error)
538 		return (error);
539 
540 	pres = vmd_find_parent_resource(sc, r);
541 	if (pres == NULL)
542 		return (ENOENT);
543 
544 	args.offset = start - rman_get_start(pres);
545 	args.length = length;
546 	return (bus_generic_map_resource(dev, child, pres, &args, map));
547 }
548 
549 static int
550 vmd_unmap_resource(device_t dev, device_t child, struct resource *r,
551     struct resource_map *map)
552 {
553 	struct vmd_softc *sc = device_get_softc(dev);
554 
555 	r = vmd_find_parent_resource(sc, r);
556 	if (r == NULL)
557 		return (ENOENT);
558 	return (bus_generic_unmap_resource(dev, child, r, map));
559 }
560 
561 static int
562 vmd_route_interrupt(device_t dev, device_t child, int pin)
563 {
564 
565 	/* VMD hardware does not support legacy interrupts. */
566 	return (PCI_INVALID_IRQ);
567 }
568 
569 static int
570 vmd_alloc_msi(device_t dev, device_t child, int count, int maxcount,
571     int *irqs)
572 {
573 	struct vmd_softc *sc = device_get_softc(dev);
574 	struct vmd_irq_user *u;
575 	int i, ibest = 0, best = INT_MAX;
576 
577 	if (sc->vmd_msix_count == 0) {
578 		return (PCIB_ALLOC_MSI(device_get_parent(device_get_parent(dev)),
579 		    child, count, maxcount, irqs));
580 	}
581 
582 	if (count > vmd_max_msi)
583 		return (ENOSPC);
584 	LIST_FOREACH(u, &sc->vmd_users, viu_link) {
585 		if (u->viu_child == child)
586 			return (EBUSY);
587 	}
588 
589 	for (i = sc->vmd_fist_vector; i < sc->vmd_msix_count; i++) {
590 		if (best > sc->vmd_irq[i].vi_nusers) {
591 			best = sc->vmd_irq[i].vi_nusers;
592 			ibest = i;
593 		}
594 	}
595 
596 	u = malloc(sizeof(*u), M_DEVBUF, M_WAITOK | M_ZERO);
597 	u->viu_child = child;
598 	u->viu_vector = ibest;
599 	LIST_INSERT_HEAD(&sc->vmd_users, u, viu_link);
600 	sc->vmd_irq[ibest].vi_nusers += count;
601 
602 	for (i = 0; i < count; i++)
603 		irqs[i] = sc->vmd_irq[ibest].vi_irq;
604 	return (0);
605 }
606 
607 static int
608 vmd_release_msi(device_t dev, device_t child, int count, int *irqs)
609 {
610 	struct vmd_softc *sc = device_get_softc(dev);
611 	struct vmd_irq_user *u;
612 
613 	if (sc->vmd_msix_count == 0) {
614 		return (PCIB_RELEASE_MSI(device_get_parent(device_get_parent(dev)),
615 		    child, count, irqs));
616 	}
617 
618 	LIST_FOREACH(u, &sc->vmd_users, viu_link) {
619 		if (u->viu_child == child) {
620 			sc->vmd_irq[u->viu_vector].vi_nusers -= count;
621 			LIST_REMOVE(u, viu_link);
622 			free(u, M_DEVBUF);
623 			return (0);
624 		}
625 	}
626 	return (EINVAL);
627 }
628 
629 static int
630 vmd_alloc_msix(device_t dev, device_t child, int *irq)
631 {
632 	struct vmd_softc *sc = device_get_softc(dev);
633 	struct vmd_irq_user *u;
634 	int i, ibest = 0, best = INT_MAX;
635 
636 	if (sc->vmd_msix_count == 0) {
637 		return (PCIB_ALLOC_MSIX(device_get_parent(device_get_parent(dev)),
638 		    child, irq));
639 	}
640 
641 	i = 0;
642 	LIST_FOREACH(u, &sc->vmd_users, viu_link) {
643 		if (u->viu_child == child)
644 			i++;
645 	}
646 	if (i >= vmd_max_msix)
647 		return (ENOSPC);
648 
649 	for (i = sc->vmd_fist_vector; i < sc->vmd_msix_count; i++) {
650 		if (best > sc->vmd_irq[i].vi_nusers) {
651 			best = sc->vmd_irq[i].vi_nusers;
652 			ibest = i;
653 		}
654 	}
655 
656 	u = malloc(sizeof(*u), M_DEVBUF, M_WAITOK | M_ZERO);
657 	u->viu_child = child;
658 	u->viu_vector = ibest;
659 	LIST_INSERT_HEAD(&sc->vmd_users, u, viu_link);
660 	sc->vmd_irq[ibest].vi_nusers++;
661 
662 	*irq = sc->vmd_irq[ibest].vi_irq;
663 	return (0);
664 }
665 
666 static int
667 vmd_release_msix(device_t dev, device_t child, int irq)
668 {
669 	struct vmd_softc *sc = device_get_softc(dev);
670 	struct vmd_irq_user *u;
671 
672 	if (sc->vmd_msix_count == 0) {
673 		return (PCIB_RELEASE_MSIX(device_get_parent(device_get_parent(dev)),
674 		    child, irq));
675 	}
676 
677 	LIST_FOREACH(u, &sc->vmd_users, viu_link) {
678 		if (u->viu_child == child &&
679 		    sc->vmd_irq[u->viu_vector].vi_irq == irq) {
680 			sc->vmd_irq[u->viu_vector].vi_nusers--;
681 			LIST_REMOVE(u, viu_link);
682 			free(u, M_DEVBUF);
683 			return (0);
684 		}
685 	}
686 	return (EINVAL);
687 }
688 
689 static int
690 vmd_map_msi(device_t dev, device_t child, int irq, uint64_t *addr, uint32_t *data)
691 {
692 	struct vmd_softc *sc = device_get_softc(dev);
693 	int i;
694 
695 	if (sc->vmd_msix_count == 0) {
696 		return (PCIB_MAP_MSI(device_get_parent(device_get_parent(dev)),
697 		    child, irq, addr, data));
698 	}
699 
700 	for (i = sc->vmd_fist_vector; i < sc->vmd_msix_count; i++) {
701 		if (sc->vmd_irq[i].vi_irq == irq)
702 			break;
703 	}
704 	if (i >= sc->vmd_msix_count)
705 		return (EINVAL);
706 	*addr = MSI_INTEL_ADDR_BASE | (i << 12);
707 	*data = 0;
708 	return (0);
709 }
710 
711 static device_method_t vmd_pci_methods[] = {
712 	/* Device interface */
713 	DEVMETHOD(device_probe,			vmd_probe),
714 	DEVMETHOD(device_attach,		vmd_attach),
715 	DEVMETHOD(device_detach,		vmd_detach),
716 	DEVMETHOD(device_suspend,		bus_generic_suspend),
717 	DEVMETHOD(device_resume,		bus_generic_resume),
718 	DEVMETHOD(device_shutdown,		bus_generic_shutdown),
719 
720 	/* Bus interface */
721 	DEVMETHOD(bus_get_dma_tag,		vmd_get_dma_tag),
722 	DEVMETHOD(bus_get_rman,			vmd_get_rman),
723 	DEVMETHOD(bus_read_ivar,		pcib_read_ivar),
724 	DEVMETHOD(bus_write_ivar,		pcib_write_ivar),
725 	DEVMETHOD(bus_alloc_resource,		vmd_alloc_resource),
726 	DEVMETHOD(bus_adjust_resource,		vmd_adjust_resource),
727 	DEVMETHOD(bus_release_resource,		vmd_release_resource),
728 	DEVMETHOD(bus_activate_resource,	vmd_activate_resource),
729 	DEVMETHOD(bus_deactivate_resource,	vmd_deactivate_resource),
730 	DEVMETHOD(bus_map_resource,		vmd_map_resource),
731 	DEVMETHOD(bus_unmap_resource,		vmd_unmap_resource),
732 	DEVMETHOD(bus_setup_intr,		bus_generic_setup_intr),
733 	DEVMETHOD(bus_teardown_intr,		bus_generic_teardown_intr),
734 
735 	/* pcib interface */
736 	DEVMETHOD(pcib_maxslots,		pcib_maxslots),
737 	DEVMETHOD(pcib_read_config,		vmd_read_config),
738 	DEVMETHOD(pcib_write_config,		vmd_write_config),
739 	DEVMETHOD(pcib_route_interrupt,		vmd_route_interrupt),
740 	DEVMETHOD(pcib_alloc_msi,		vmd_alloc_msi),
741 	DEVMETHOD(pcib_release_msi,		vmd_release_msi),
742 	DEVMETHOD(pcib_alloc_msix,		vmd_alloc_msix),
743 	DEVMETHOD(pcib_release_msix,		vmd_release_msix),
744 	DEVMETHOD(pcib_map_msi,			vmd_map_msi),
745 	DEVMETHOD(pcib_request_feature,		pcib_request_feature_allow),
746 
747 	DEVMETHOD_END
748 };
749 
750 DEFINE_CLASS_0(pcib, vmd_pci_driver, vmd_pci_methods, sizeof(struct vmd_softc));
751 DRIVER_MODULE(vmd, pci, vmd_pci_driver, NULL, NULL);
752 MODULE_PNP_INFO("U16:vendor;U16:device;D:#", pci, vmd,
753     vmd_devs, nitems(vmd_devs) - 1);
754