xref: /freebsd/sys/dev/pci/vga_pci.c (revision 22cf89c938886d14f5796fc49f9f020c23ea8eaf)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2005 John Baldwin <jhb@FreeBSD.org>
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 /*
30  * Simple driver for PCI VGA display devices.  Drivers such as agp(4) and
31  * drm(4) should attach as children of this device.
32  *
33  * XXX: The vgapci name is a hack until we somehow merge the isa vga driver
34  * in or rename it.
35  */
36 
37 #include <sys/param.h>
38 #include <sys/bus.h>
39 #include <sys/kernel.h>
40 #include <sys/module.h>
41 #include <sys/rman.h>
42 #include <sys/sysctl.h>
43 #include <sys/systm.h>
44 
45 #if defined(__amd64__) || defined(__i386__)
46 #include <vm/vm.h>
47 #include <vm/pmap.h>
48 #endif
49 
50 #include <dev/pci/pcireg.h>
51 #include <dev/pci/pcivar.h>
52 
53 #include <compat/x86bios/x86bios.h> /* To re-POST the card. */
54 
55 struct vga_resource {
56 	struct resource	*vr_res;
57 	int	vr_refs;
58 };
59 
60 struct vga_pci_softc {
61 	device_t	vga_msi_child;	/* Child driver using MSI. */
62 	struct vga_resource vga_bars[PCIR_MAX_BAR_0 + 1];
63 	struct vga_resource vga_bios;
64 };
65 
66 SYSCTL_DECL(_hw_pci);
67 
68 static struct vga_resource *lookup_res(struct vga_pci_softc *sc, int rid);
69 static struct resource *vga_pci_alloc_resource(device_t dev, device_t child,
70     int type, int *rid, rman_res_t start, rman_res_t end, rman_res_t count,
71     u_int flags);
72 static int	vga_pci_release_resource(device_t dev, device_t child, int type,
73     int rid, struct resource *r);
74 
75 int vga_pci_default_unit = -1;
76 SYSCTL_INT(_hw_pci, OID_AUTO, default_vgapci_unit, CTLFLAG_RDTUN,
77     &vga_pci_default_unit, -1, "Default VGA-compatible display");
78 
79 int
80 vga_pci_is_boot_display(device_t dev)
81 {
82 	int unit;
83 	device_t pcib;
84 	uint16_t config;
85 
86 	/* Check that the given device is a video card */
87 	if ((pci_get_class(dev) != PCIC_DISPLAY &&
88 	    (pci_get_class(dev) != PCIC_OLD ||
89 	     pci_get_subclass(dev) != PCIS_OLD_VGA)))
90 		return (0);
91 
92 	unit = device_get_unit(dev);
93 
94 	if (vga_pci_default_unit >= 0) {
95 		/*
96 		 * The boot display device was determined by a previous
97 		 * call to this function, or the user forced it using
98 		 * the hw.pci.default_vgapci_unit tunable.
99 		 */
100 		return (vga_pci_default_unit == unit);
101 	}
102 
103 	/*
104 	 * The primary video card used as a boot display must have the
105 	 * "I/O" and "Memory Address Space Decoding" bits set in its
106 	 * Command register.
107 	 *
108 	 * Furthermore, if the card is attached to a bridge, instead of
109 	 * the root PCI bus, the bridge must have the "VGA Enable" bit
110 	 * set in its Control register.
111 	 */
112 
113 	pcib = device_get_parent(device_get_parent(dev));
114 	if (device_get_devclass(device_get_parent(pcib)) ==
115 	    devclass_find("pci")) {
116 		/*
117 		 * The parent bridge is a PCI-to-PCI bridge: check the
118 		 * value of the "VGA Enable" bit.
119 		 */
120 		config = pci_read_config(pcib, PCIR_BRIDGECTL_1, 2);
121 		if ((config & PCIB_BCR_VGA_ENABLE) == 0)
122 			return (0);
123 	}
124 
125 	config = pci_read_config(dev, PCIR_COMMAND, 2);
126 	if ((config & (PCIM_CMD_PORTEN | PCIM_CMD_MEMEN)) == 0)
127 		return (0);
128 
129 	/*
130 	 * Disable interrupts until a chipset driver is loaded for
131 	 * this PCI device. Else unhandled display adapter interrupts
132 	 * might freeze the CPU.
133 	 */
134 	pci_write_config(dev, PCIR_COMMAND, config | PCIM_CMD_INTxDIS, 2);
135 
136 	/* This video card is the boot display: record its unit number. */
137 	vga_pci_default_unit = unit;
138 	device_set_flags(dev, 1);
139 
140 	return (1);
141 }
142 
143 static void
144 vga_pci_reset(device_t dev)
145 {
146 	int ps;
147 	/*
148 	 * FLR is unsupported on GPUs so attempt a power-management reset by cycling
149 	 * the device in/out of D3 state.
150 	 * PCI spec says we can only go into D3 state from D0 state.
151 	 * Transition from D[12] into D0 before going to D3 state.
152 	 */
153 	ps = pci_get_powerstate(dev);
154 	if (ps != PCI_POWERSTATE_D0 && ps != PCI_POWERSTATE_D3)
155 		pci_set_powerstate(dev, PCI_POWERSTATE_D0);
156 	if (pci_get_powerstate(dev) != PCI_POWERSTATE_D3)
157 		pci_set_powerstate(dev, PCI_POWERSTATE_D3);
158 	pci_set_powerstate(dev, ps);
159 }
160 
161 void *
162 vga_pci_map_bios(device_t dev, size_t *size)
163 {
164 	struct vga_resource *vr;
165 	struct resource *res;
166 	device_t pcib;
167 	uint32_t rom_addr;
168 	uint16_t config;
169 	volatile unsigned char *bios;
170 	int i, rid, found;
171 
172 #if defined(__amd64__) || defined(__i386__)
173 	if (vga_pci_is_boot_display(dev)) {
174 		/*
175 		 * On x86, the System BIOS copy the default display
176 		 * device's Video BIOS at a fixed location in system
177 		 * memory (0xC0000, 128 kBytes long) at boot time.
178 		 *
179 		 * We use this copy for the default boot device, because
180 		 * the original ROM may not be valid after boot.
181 		 */
182 
183 		*size = VGA_PCI_BIOS_SHADOW_SIZE;
184 		return (pmap_mapbios(VGA_PCI_BIOS_SHADOW_ADDR, *size));
185 	}
186 #endif
187 
188 	pcib = device_get_parent(device_get_parent(dev));
189 	if (device_get_devclass(device_get_parent(pcib)) ==
190 	    devclass_find("pci")) {
191 		/*
192 		 * The parent bridge is a PCI-to-PCI bridge: check the
193 		 * value of the "VGA Enable" bit.
194 		 */
195 		config = pci_read_config(pcib, PCIR_BRIDGECTL_1, 2);
196 		if ((config & PCIB_BCR_VGA_ENABLE) == 0) {
197 			config |= PCIB_BCR_VGA_ENABLE;
198 			pci_write_config(pcib, PCIR_BRIDGECTL_1, config, 2);
199 		}
200 	}
201 
202 	switch(pci_read_config(dev, PCIR_HDRTYPE, 1)) {
203 	case PCIM_HDRTYPE_BRIDGE:
204 		rid = PCIR_BIOS_1;
205 		break;
206 	case PCIM_HDRTYPE_CARDBUS:
207 		rid = 0;
208 		break;
209 	default:
210 		rid = PCIR_BIOS;
211 		break;
212 	}
213 	if (rid == 0)
214 		return (NULL);
215 	res = vga_pci_alloc_resource(dev, NULL, SYS_RES_MEMORY, &rid, 0,
216 	    ~0, 1, RF_ACTIVE);
217 
218 	if (res == NULL) {
219 		device_printf(dev, "vga_pci_alloc_resource failed\n");
220 		return (NULL);
221 	}
222 	bios = rman_get_virtual(res);
223 	*size = rman_get_size(res);
224 	for (found = i = 0; i < hz; i++) {
225 		found = (bios[0] == 0x55 && bios[1] == 0xaa);
226 		if (found)
227 			break;
228 		pause("vgabios", 1);
229 	}
230 	if (found)
231 		return (__DEVOLATILE(void *, bios));
232 	if (bootverbose)
233 		device_printf(dev, "initial ROM mapping failed -- resetting\n");
234 
235 	/*
236 	 * Enable ROM decode
237 	 */
238 	vga_pci_reset(dev);
239 	rom_addr = pci_read_config(dev, rid, 4);
240 	rom_addr &= 0x7ff;
241 	rom_addr |= rman_get_start(res) | 0x1;
242 	pci_write_config(dev, rid, rom_addr, 4);
243 	vr = lookup_res(device_get_softc(dev), rid);
244 	vga_pci_release_resource(dev, NULL, SYS_RES_MEMORY, rid,
245 	    vr->vr_res);
246 
247 	/*
248 	 * re-allocate
249 	 */
250 	res = vga_pci_alloc_resource(dev, NULL, SYS_RES_MEMORY, &rid, 0,
251 	    ~0, 1, RF_ACTIVE);
252 	if (res == NULL) {
253 		device_printf(dev, "vga_pci_alloc_resource failed\n");
254 		return (NULL);
255 	}
256 	bios = rman_get_virtual(res);
257 	*size = rman_get_size(res);
258 	for (found = i = 0; i < 3*hz; i++) {
259 		found = (bios[0] == 0x55 && bios[1] == 0xaa);
260 		if (found)
261 			break;
262 		pause("vgabios", 1);
263 	}
264 	if (found)
265 		return (__DEVOLATILE(void *, bios));
266 	device_printf(dev, "ROM mapping failed\n");
267 	vr = lookup_res(device_get_softc(dev), rid);
268 	vga_pci_release_resource(dev, NULL, SYS_RES_MEMORY, rid,
269 	    vr->vr_res);
270 	return (NULL);
271 }
272 
273 void
274 vga_pci_unmap_bios(device_t dev, void *bios)
275 {
276 	struct vga_resource *vr;
277 	int rid;
278 
279 	if (bios == NULL) {
280 		return;
281 	}
282 
283 #if defined(__amd64__) || defined(__i386__)
284 	if (vga_pci_is_boot_display(dev)) {
285 		/* We mapped the BIOS shadow copy located at 0xC0000. */
286 		pmap_unmapdev(bios, VGA_PCI_BIOS_SHADOW_SIZE);
287 
288 		return;
289 	}
290 #endif
291 	switch(pci_read_config(dev, PCIR_HDRTYPE, 1)) {
292 	case PCIM_HDRTYPE_BRIDGE:
293 		rid = PCIR_BIOS_1;
294 		break;
295 	case PCIM_HDRTYPE_CARDBUS:
296 		rid = 0;
297 		break;
298 	default:
299 		rid = PCIR_BIOS;
300 		break;
301 	}
302 	if (rid == 0)
303 		return;
304 	/*
305 	 * Look up the PCIR_BIOS resource in our softc.  It should match
306 	 * the address we returned previously.
307 	 */
308 	vr = lookup_res(device_get_softc(dev), rid);
309 	KASSERT(vr->vr_res != NULL, ("vga_pci_unmap_bios: bios not mapped"));
310 	KASSERT(rman_get_virtual(vr->vr_res) == bios,
311 	    ("vga_pci_unmap_bios: mismatch"));
312 	vga_pci_release_resource(dev, NULL, SYS_RES_MEMORY, rid,
313 	    vr->vr_res);
314 }
315 
316 int
317 vga_pci_repost(device_t dev)
318 {
319 #if defined(__amd64__) || defined(__i386__)
320 	x86regs_t regs;
321 
322 	if (!vga_pci_is_boot_display(dev))
323 		return (EINVAL);
324 
325 	if (x86bios_get_orm(VGA_PCI_BIOS_SHADOW_ADDR) == NULL)
326 		return (ENOTSUP);
327 
328 	x86bios_init_regs(&regs);
329 
330 	regs.R_AH = pci_get_bus(dev);
331 	regs.R_AL = (pci_get_slot(dev) << 3) | (pci_get_function(dev) & 0x07);
332 	regs.R_DL = 0x80;
333 
334 	device_printf(dev, "REPOSTing\n");
335 	x86bios_call(&regs, X86BIOS_PHYSTOSEG(VGA_PCI_BIOS_SHADOW_ADDR + 3),
336 	    X86BIOS_PHYSTOOFF(VGA_PCI_BIOS_SHADOW_ADDR + 3));
337 
338 	x86bios_get_intr(0x10);
339 
340 	return (0);
341 #else
342 	return (ENOTSUP);
343 #endif
344 }
345 
346 static int
347 vga_pci_probe(device_t dev)
348 {
349 
350 	switch (pci_get_class(dev)) {
351 	case PCIC_DISPLAY:
352 		break;
353 	case PCIC_OLD:
354 		if (pci_get_subclass(dev) != PCIS_OLD_VGA)
355 			return (ENXIO);
356 		break;
357 	default:
358 		return (ENXIO);
359 	}
360 
361 	/* Probe default display. */
362 	vga_pci_is_boot_display(dev);
363 
364 	device_set_desc(dev, "VGA-compatible display");
365 	return (BUS_PROBE_GENERIC);
366 }
367 
368 static int
369 vga_pci_attach(device_t dev)
370 {
371 
372 	bus_generic_probe(dev);
373 
374 	/* Always create a drmn child for now to make it easier on drm. */
375 	device_add_child(dev, "drmn", -1);
376 	bus_generic_attach(dev);
377 
378 	if (vga_pci_is_boot_display(dev))
379 		device_printf(dev, "Boot video device\n");
380 
381 	return (0);
382 }
383 
384 static int
385 vga_pci_suspend(device_t dev)
386 {
387 
388 	return (bus_generic_suspend(dev));
389 }
390 
391 static int
392 vga_pci_detach(device_t dev)
393 {
394 	int error;
395 
396 	error = bus_generic_detach(dev);
397 	if (error == 0)
398 		error = device_delete_children(dev);
399 	return (error);
400 }
401 
402 static int
403 vga_pci_resume(device_t dev)
404 {
405 
406 	return (bus_generic_resume(dev));
407 }
408 
409 /* Bus interface. */
410 
411 static int
412 vga_pci_read_ivar(device_t dev, device_t child, int which, uintptr_t *result)
413 {
414 
415 	return (BUS_READ_IVAR(device_get_parent(dev), dev, which, result));
416 }
417 
418 static int
419 vga_pci_write_ivar(device_t dev, device_t child, int which, uintptr_t value)
420 {
421 
422 	return (EINVAL);
423 }
424 
425 static int
426 vga_pci_setup_intr(device_t dev, device_t child, struct resource *irq,
427     int flags, driver_filter_t *filter, driver_intr_t *intr, void *arg,
428     void **cookiep)
429 {
430 	return (BUS_SETUP_INTR(device_get_parent(dev), dev, irq, flags,
431 	    filter, intr, arg, cookiep));
432 }
433 
434 static int
435 vga_pci_teardown_intr(device_t dev, device_t child, struct resource *irq,
436     void *cookie)
437 {
438 	return (BUS_TEARDOWN_INTR(device_get_parent(dev), dev, irq, cookie));
439 }
440 
441 static struct vga_resource *
442 lookup_res(struct vga_pci_softc *sc, int rid)
443 {
444 	int bar;
445 
446 	if (rid == PCIR_BIOS)
447 		return (&sc->vga_bios);
448 	bar = PCI_RID2BAR(rid);
449 	if (bar >= 0 && bar <= PCIR_MAX_BAR_0)
450 		return (&sc->vga_bars[bar]);
451 	return (NULL);
452 }
453 
454 static struct resource *
455 vga_pci_alloc_resource(device_t dev, device_t child, int type, int *rid,
456     rman_res_t start, rman_res_t end, rman_res_t count, u_int flags)
457 {
458 	struct vga_resource *vr;
459 
460 	switch (type) {
461 	case SYS_RES_MEMORY:
462 	case SYS_RES_IOPORT:
463 		/*
464 		 * For BARs, we cache the resource so that we only allocate it
465 		 * from the PCI bus once.
466 		 */
467 		vr = lookup_res(device_get_softc(dev), *rid);
468 		if (vr == NULL)
469 			return (NULL);
470 		if (vr->vr_res == NULL)
471 			vr->vr_res = bus_alloc_resource(dev, type, rid, start,
472 			    end, count, flags);
473 		if (vr->vr_res != NULL)
474 			vr->vr_refs++;
475 		return (vr->vr_res);
476 	}
477 	return (bus_alloc_resource(dev, type, rid, start, end, count, flags));
478 }
479 
480 static int
481 vga_pci_release_resource(device_t dev, device_t child, int type, int rid,
482     struct resource *r)
483 {
484 	struct vga_resource *vr;
485 	int error;
486 
487 	switch (type) {
488 	case SYS_RES_MEMORY:
489 	case SYS_RES_IOPORT:
490 		/*
491 		 * For BARs, we release the resource from the PCI bus
492 		 * when the last child reference goes away.
493 		 */
494 		vr = lookup_res(device_get_softc(dev), rid);
495 		if (vr == NULL)
496 			return (EINVAL);
497 		if (vr->vr_res == NULL)
498 			return (EINVAL);
499 		KASSERT(vr->vr_res == r, ("vga_pci resource mismatch"));
500 		if (vr->vr_refs > 1) {
501 			vr->vr_refs--;
502 			return (0);
503 		}
504 		KASSERT(vr->vr_refs > 0,
505 		    ("vga_pci resource reference count underflow"));
506 		error = bus_release_resource(dev, type, rid, r);
507 		if (error == 0) {
508 			vr->vr_res = NULL;
509 			vr->vr_refs = 0;
510 		}
511 		return (error);
512 	}
513 
514 	return (bus_release_resource(dev, type, rid, r));
515 }
516 
517 /* PCI interface. */
518 
519 static uint32_t
520 vga_pci_read_config(device_t dev, device_t child, int reg, int width)
521 {
522 
523 	return (pci_read_config(dev, reg, width));
524 }
525 
526 static void
527 vga_pci_write_config(device_t dev, device_t child, int reg,
528     uint32_t val, int width)
529 {
530 
531 	pci_write_config(dev, reg, val, width);
532 }
533 
534 static int
535 vga_pci_enable_busmaster(device_t dev, device_t child)
536 {
537 
538 	return (pci_enable_busmaster(dev));
539 }
540 
541 static int
542 vga_pci_disable_busmaster(device_t dev, device_t child)
543 {
544 
545 	return (pci_disable_busmaster(dev));
546 }
547 
548 static int
549 vga_pci_enable_io(device_t dev, device_t child, int space)
550 {
551 
552 	device_printf(dev, "child %s requested pci_enable_io\n",
553 	    device_get_nameunit(child));
554 	return (pci_enable_io(dev, space));
555 }
556 
557 static int
558 vga_pci_disable_io(device_t dev, device_t child, int space)
559 {
560 
561 	device_printf(dev, "child %s requested pci_disable_io\n",
562 	    device_get_nameunit(child));
563 	return (pci_disable_io(dev, space));
564 }
565 
566 static int
567 vga_pci_get_vpd_ident(device_t dev, device_t child, const char **identptr)
568 {
569 
570 	return (pci_get_vpd_ident(dev, identptr));
571 }
572 
573 static int
574 vga_pci_get_vpd_readonly(device_t dev, device_t child, const char *kw,
575     const char **vptr)
576 {
577 
578 	return (pci_get_vpd_readonly(dev, kw, vptr));
579 }
580 
581 static int
582 vga_pci_set_powerstate(device_t dev, device_t child, int state)
583 {
584 
585 	device_printf(dev, "child %s requested pci_set_powerstate\n",
586 	    device_get_nameunit(child));
587 	return (pci_set_powerstate(dev, state));
588 }
589 
590 static int
591 vga_pci_get_powerstate(device_t dev, device_t child)
592 {
593 
594 	device_printf(dev, "child %s requested pci_get_powerstate\n",
595 	    device_get_nameunit(child));
596 	return (pci_get_powerstate(dev));
597 }
598 
599 static int
600 vga_pci_assign_interrupt(device_t dev, device_t child)
601 {
602 
603 	device_printf(dev, "child %s requested pci_assign_interrupt\n",
604 	    device_get_nameunit(child));
605 	return (PCI_ASSIGN_INTERRUPT(device_get_parent(dev), dev));
606 }
607 
608 static int
609 vga_pci_find_cap(device_t dev, device_t child, int capability,
610     int *capreg)
611 {
612 
613 	return (pci_find_cap(dev, capability, capreg));
614 }
615 
616 static int
617 vga_pci_find_next_cap(device_t dev, device_t child, int capability,
618     int start, int *capreg)
619 {
620 
621 	return (pci_find_next_cap(dev, capability, start, capreg));
622 }
623 
624 static int
625 vga_pci_find_extcap(device_t dev, device_t child, int capability,
626     int *capreg)
627 {
628 
629 	return (pci_find_extcap(dev, capability, capreg));
630 }
631 
632 static int
633 vga_pci_find_next_extcap(device_t dev, device_t child, int capability,
634     int start, int *capreg)
635 {
636 
637 	return (pci_find_next_extcap(dev, capability, start, capreg));
638 }
639 
640 static int
641 vga_pci_find_htcap(device_t dev, device_t child, int capability,
642     int *capreg)
643 {
644 
645 	return (pci_find_htcap(dev, capability, capreg));
646 }
647 
648 static int
649 vga_pci_find_next_htcap(device_t dev, device_t child, int capability,
650     int start, int *capreg)
651 {
652 
653 	return (pci_find_next_htcap(dev, capability, start, capreg));
654 }
655 
656 static int
657 vga_pci_alloc_msi(device_t dev, device_t child, int *count)
658 {
659 	struct vga_pci_softc *sc;
660 	int error;
661 
662 	sc = device_get_softc(dev);
663 	if (sc->vga_msi_child != NULL)
664 		return (EBUSY);
665 	error = pci_alloc_msi(dev, count);
666 	if (error == 0)
667 		sc->vga_msi_child = child;
668 	return (error);
669 }
670 
671 static int
672 vga_pci_alloc_msix(device_t dev, device_t child, int *count)
673 {
674 	struct vga_pci_softc *sc;
675 	int error;
676 
677 	sc = device_get_softc(dev);
678 	if (sc->vga_msi_child != NULL)
679 		return (EBUSY);
680 	error = pci_alloc_msix(dev, count);
681 	if (error == 0)
682 		sc->vga_msi_child = child;
683 	return (error);
684 }
685 
686 static int
687 vga_pci_remap_msix(device_t dev, device_t child, int count,
688     const u_int *vectors)
689 {
690 	struct vga_pci_softc *sc;
691 
692 	sc = device_get_softc(dev);
693 	if (sc->vga_msi_child != child)
694 		return (ENXIO);
695 	return (pci_remap_msix(dev, count, vectors));
696 }
697 
698 static int
699 vga_pci_release_msi(device_t dev, device_t child)
700 {
701 	struct vga_pci_softc *sc;
702 	int error;
703 
704 	sc = device_get_softc(dev);
705 	if (sc->vga_msi_child != child)
706 		return (ENXIO);
707 	error = pci_release_msi(dev);
708 	if (error == 0)
709 		sc->vga_msi_child = NULL;
710 	return (error);
711 }
712 
713 static int
714 vga_pci_msi_count(device_t dev, device_t child)
715 {
716 
717 	return (pci_msi_count(dev));
718 }
719 
720 static int
721 vga_pci_msix_count(device_t dev, device_t child)
722 {
723 
724 	return (pci_msix_count(dev));
725 }
726 
727 static bus_dma_tag_t
728 vga_pci_get_dma_tag(device_t bus, device_t child)
729 {
730 
731 	return (bus_get_dma_tag(bus));
732 }
733 
734 static device_method_t vga_pci_methods[] = {
735 	/* Device interface */
736 	DEVMETHOD(device_probe,		vga_pci_probe),
737 	DEVMETHOD(device_attach,	vga_pci_attach),
738 	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
739 	DEVMETHOD(device_suspend,	vga_pci_suspend),
740 	DEVMETHOD(device_detach,	vga_pci_detach),
741 	DEVMETHOD(device_resume,	vga_pci_resume),
742 
743 	/* Bus interface */
744 	DEVMETHOD(bus_read_ivar,	vga_pci_read_ivar),
745 	DEVMETHOD(bus_write_ivar,	vga_pci_write_ivar),
746 	DEVMETHOD(bus_setup_intr,	vga_pci_setup_intr),
747 	DEVMETHOD(bus_teardown_intr,	vga_pci_teardown_intr),
748 	DEVMETHOD(bus_alloc_resource,	vga_pci_alloc_resource),
749 	DEVMETHOD(bus_release_resource,	vga_pci_release_resource),
750 	DEVMETHOD(bus_activate_resource, bus_generic_activate_resource),
751 	DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource),
752 	DEVMETHOD(bus_get_dma_tag,	vga_pci_get_dma_tag),
753 
754 	/* PCI interface */
755 	DEVMETHOD(pci_read_config,	vga_pci_read_config),
756 	DEVMETHOD(pci_write_config,	vga_pci_write_config),
757 	DEVMETHOD(pci_enable_busmaster,	vga_pci_enable_busmaster),
758 	DEVMETHOD(pci_disable_busmaster, vga_pci_disable_busmaster),
759 	DEVMETHOD(pci_enable_io,	vga_pci_enable_io),
760 	DEVMETHOD(pci_disable_io,	vga_pci_disable_io),
761 	DEVMETHOD(pci_get_vpd_ident,	vga_pci_get_vpd_ident),
762 	DEVMETHOD(pci_get_vpd_readonly,	vga_pci_get_vpd_readonly),
763 	DEVMETHOD(pci_get_powerstate,	vga_pci_get_powerstate),
764 	DEVMETHOD(pci_set_powerstate,	vga_pci_set_powerstate),
765 	DEVMETHOD(pci_assign_interrupt,	vga_pci_assign_interrupt),
766 	DEVMETHOD(pci_find_cap,		vga_pci_find_cap),
767 	DEVMETHOD(pci_find_next_cap,	vga_pci_find_next_cap),
768 	DEVMETHOD(pci_find_extcap,	vga_pci_find_extcap),
769 	DEVMETHOD(pci_find_next_extcap,	vga_pci_find_next_extcap),
770 	DEVMETHOD(pci_find_htcap,	vga_pci_find_htcap),
771 	DEVMETHOD(pci_find_next_htcap,	vga_pci_find_next_htcap),
772 	DEVMETHOD(pci_alloc_msi,	vga_pci_alloc_msi),
773 	DEVMETHOD(pci_alloc_msix,	vga_pci_alloc_msix),
774 	DEVMETHOD(pci_remap_msix,	vga_pci_remap_msix),
775 	DEVMETHOD(pci_release_msi,	vga_pci_release_msi),
776 	DEVMETHOD(pci_msi_count,	vga_pci_msi_count),
777 	DEVMETHOD(pci_msix_count,	vga_pci_msix_count),
778 	{ 0, 0 }
779 };
780 
781 static driver_t vga_pci_driver = {
782 	"vgapci",
783 	vga_pci_methods,
784 	sizeof(struct vga_pci_softc),
785 };
786 
787 DRIVER_MODULE(vgapci, pci, vga_pci_driver, 0, 0);
788 MODULE_DEPEND(vgapci, x86bios, 1, 1, 1);
789