xref: /dragonfly/sys/dev/agp/agp.c (revision a32bc35d)
1 /*-
2  * Copyright (c) 2000 Doug Rabson
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  *	$FreeBSD: src/sys/dev/agp/agp.c,v 1.58 2007/11/12 21:51:36 jhb Exp $
27  */
28 
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/device.h>
32 #include <sys/conf.h>
33 #include <sys/malloc.h>
34 #include <sys/kernel.h>
35 #include <sys/bus.h>
36 #include <sys/agpio.h>
37 #include <sys/lock.h>
38 #include <sys/proc.h>
39 #include <sys/rman.h>
40 
41 #include <bus/pci/pcivar.h>
42 #include <bus/pci/pcireg.h>
43 #include "agppriv.h"
44 #include "agpvar.h"
45 #include "agpreg.h"
46 
47 #include <vm/vm.h>
48 #include <vm/vm_object.h>
49 #include <vm/vm_page.h>
50 #include <vm/vm_pageout.h>
51 #include <vm/pmap.h>
52 
53 #include <machine/md_var.h>
54 
55 MODULE_VERSION(agp, 1);
56 
57 MALLOC_DEFINE(M_AGP, "agp", "AGP data structures");
58 
59 static d_open_t agp_open;
60 static d_close_t agp_close;
61 static d_ioctl_t agp_ioctl;
62 static d_mmap_t agp_mmap;
63 
64 static struct dev_ops agp_ops = {
65 	{ "agp", 0, D_TTY },
66 	.d_open =	agp_open,
67 	.d_close =	agp_close,
68 	.d_ioctl =	agp_ioctl,
69 	.d_mmap =	agp_mmap,
70 };
71 
72 static devclass_t agp_devclass;
73 #define KDEV2DEV(kdev)	devclass_get_device(agp_devclass, minor(kdev))
74 
75 /* Helper functions for implementing chipset mini drivers. */
76 
77 void
78 agp_flush_cache(void)
79 {
80 #if defined(__i386__) || defined(__x86_64__)
81 	wbinvd();
82 #endif
83 }
84 
85 u_int8_t
86 agp_find_caps(device_t dev)
87 {
88 	int capreg;
89 
90 	if (pci_find_extcap(dev, PCIY_AGP, &capreg) != 0)
91 		capreg = 0;
92 	return (capreg);
93 }
94 
95 /*
96  * Find an AGP display device (if any).
97  */
98 static device_t
99 agp_find_display(void)
100 {
101 	devclass_t pci = devclass_find("pci");
102 	device_t bus, dev = 0;
103 	device_t *kids;
104 	int busnum, numkids, i;
105 
106 	for (busnum = 0; busnum < devclass_get_maxunit(pci); busnum++) {
107 		bus = devclass_get_device(pci, busnum);
108 		if (!bus)
109 			continue;
110 		device_get_children(bus, &kids, &numkids);
111 		for (i = 0; i < numkids; i++) {
112 			dev = kids[i];
113 			if (pci_get_class(dev) == PCIC_DISPLAY
114 			    && pci_get_subclass(dev) == PCIS_DISPLAY_VGA)
115 				if (agp_find_caps(dev)) {
116 					kfree(kids, M_TEMP);
117 					return dev;
118 				}
119 
120 		}
121 		kfree(kids, M_TEMP);
122 	}
123 
124 	return 0;
125 }
126 
127 struct agp_gatt *
128 agp_alloc_gatt(device_t dev)
129 {
130 	u_int32_t apsize = AGP_GET_APERTURE(dev);
131 	u_int32_t entries = apsize >> AGP_PAGE_SHIFT;
132 	struct agp_gatt *gatt;
133 
134 	if (bootverbose)
135 		device_printf(dev,
136 			      "allocating GATT for aperture of size %dM\n",
137 			      apsize / (1024*1024));
138 
139 	if (entries == 0) {
140 		device_printf(dev, "bad aperture size\n");
141 		return NULL;
142 	}
143 
144 	gatt = kmalloc(sizeof(struct agp_gatt), M_AGP, M_INTWAIT);
145 	gatt->ag_entries = entries;
146 	gatt->ag_virtual = contigmalloc(entries * sizeof(u_int32_t), M_AGP,
147 					M_WAITOK|M_ZERO, 0, ~0, PAGE_SIZE, 0);
148 	if (!gatt->ag_virtual) {
149 		if (bootverbose)
150 			device_printf(dev, "contiguous allocation failed\n");
151 		kfree(gatt, M_AGP);
152 		return 0;
153 	}
154 	gatt->ag_physical = vtophys((vm_offset_t) gatt->ag_virtual);
155 	agp_flush_cache();
156 
157 	return gatt;
158 }
159 
160 void
161 agp_free_gatt(struct agp_gatt *gatt)
162 {
163 	contigfree(gatt->ag_virtual,
164 		   gatt->ag_entries * sizeof(u_int32_t), M_AGP);
165 	kfree(gatt, M_AGP);
166 }
167 
168 static u_int agp_max[][2] = {
169 	{0,	0},
170 	{32,	4},
171 	{64,	28},
172 	{128,	96},
173 	{256,	204},
174 	{512,	440},
175 	{1024,	942},
176 	{2048,	1920},
177 	{4096,	3932}
178 };
179 #define agp_max_size	NELEM(agp_max)
180 
181 /**
182  * Sets the PCI resource which represents the AGP aperture.
183  *
184  * If not called, the default AGP aperture resource of AGP_APBASE will
185  * be used.  Must be called before agp_generic_attach().
186  */
187 void
188 agp_set_aperture_resource(device_t dev, int rid)
189 {
190 	struct agp_softc *sc = device_get_softc(dev);
191 
192 	sc->as_aperture_rid = rid;
193 }
194 
195 int
196 agp_generic_attach(device_t dev)
197 {
198 	struct agp_softc *sc = device_get_softc(dev);
199 	int i;
200 	u_int memsize;
201 
202 	/*
203 	 * Find and map the aperture, RF_SHAREABLE for DRM but not RF_ACTIVE
204 	 * because the kernel doesn't need to map it.
205 	 */
206 	if (sc->as_aperture_rid == 0)
207 		sc->as_aperture_rid = AGP_APBASE;
208 
209 	sc->as_aperture = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
210 	    &sc->as_aperture_rid, RF_SHAREABLE);
211 	if (!sc->as_aperture)
212 		return ENOMEM;
213 
214 	/*
215 	 * Work out an upper bound for agp memory allocation. This
216 	 * uses a heurisitc table from the Linux driver.
217 	 */
218 	memsize = ptoa(Maxmem) >> 20;
219 	for (i = 0; i < agp_max_size; i++) {
220 		if (memsize <= agp_max[i][0])
221 			break;
222 	}
223 	if (i == agp_max_size) i = agp_max_size - 1;
224 	sc->as_maxmem = agp_max[i][1] << 20U;
225 
226 	/*
227 	 * The lock is used to prevent re-entry to
228 	 * agp_generic_bind_memory() since that function can sleep.
229 	 */
230 	lockinit(&sc->as_lock, "agplk", 0, 0);
231 
232 	/*
233 	 * Initialise stuff for the userland device.
234 	 */
235 	agp_devclass = devclass_find("agp");
236 	TAILQ_INIT(&sc->as_memory);
237 	sc->as_nextid = 1;
238 
239 	make_dev(&agp_ops, device_get_unit(dev), UID_ROOT, GID_WHEEL,
240 		 0600, "agpgart");
241 
242 	return 0;
243 }
244 
245 void
246 agp_free_cdev(device_t dev)
247 {
248 	dev_ops_remove_minor(&agp_ops, device_get_unit(dev));
249 }
250 
251 void
252 agp_free_res(device_t dev)
253 {
254 	struct agp_softc *sc = device_get_softc(dev);
255 
256 	bus_release_resource(dev, SYS_RES_MEMORY, sc->as_aperture_rid,
257 			     sc->as_aperture);
258 	agp_flush_cache();
259 }
260 
261 int
262 agp_generic_detach(device_t dev)
263 {
264 	agp_free_cdev(dev);
265 	agp_free_res(dev);
266 	return 0;
267 }
268 
269 /**
270  * Default AGP aperture size detection which simply returns the size of
271  * the aperture's PCI resource.
272  */
273 int
274 agp_generic_get_aperture(device_t dev)
275 {
276 	struct agp_softc *sc = device_get_softc(dev);
277 
278 	return rman_get_size(sc->as_aperture);
279 }
280 
281 /**
282  * Default AGP aperture size setting function, which simply doesn't allow
283  * changes to resource size.
284  */
285 int
286 agp_generic_set_aperture(device_t dev, u_int32_t aperture)
287 {
288 	u_int32_t current_aperture;
289 
290 	current_aperture = AGP_GET_APERTURE(dev);
291 	if (current_aperture != aperture)
292 		return EINVAL;
293 	else
294 		return 0;
295 }
296 
297 /*
298  * This does the enable logic for v3, with the same topology
299  * restrictions as in place for v2 -- one bus, one device on the bus.
300  */
301 static int
302 agp_v3_enable(device_t dev, device_t mdev, u_int32_t mode)
303 {
304 	u_int32_t tstatus, mstatus;
305 	u_int32_t command;
306 	int rq, sba, fw, rate, arqsz, cal;
307 
308 	tstatus = pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
309 	mstatus = pci_read_config(mdev, agp_find_caps(mdev) + AGP_STATUS, 4);
310 
311 	/* Set RQ to the min of mode, tstatus and mstatus */
312 	rq = AGP_MODE_GET_RQ(mode);
313 	if (AGP_MODE_GET_RQ(tstatus) < rq)
314 		rq = AGP_MODE_GET_RQ(tstatus);
315 	if (AGP_MODE_GET_RQ(mstatus) < rq)
316 		rq = AGP_MODE_GET_RQ(mstatus);
317 
318 	/*
319 	 * ARQSZ - Set the value to the maximum one.
320 	 * Don't allow the mode register to override values.
321 	 */
322 	arqsz = AGP_MODE_GET_ARQSZ(mode);
323 	if (AGP_MODE_GET_ARQSZ(tstatus) > rq)
324 		rq = AGP_MODE_GET_ARQSZ(tstatus);
325 	if (AGP_MODE_GET_ARQSZ(mstatus) > rq)
326 		rq = AGP_MODE_GET_ARQSZ(mstatus);
327 
328 	/* Calibration cycle - don't allow override by mode register */
329 	cal = AGP_MODE_GET_CAL(tstatus);
330 	if (AGP_MODE_GET_CAL(mstatus) < cal)
331 		cal = AGP_MODE_GET_CAL(mstatus);
332 
333 	/* SBA must be supported for AGP v3. */
334 	sba = 1;
335 
336 	/* Set FW if all three support it. */
337 	fw = (AGP_MODE_GET_FW(tstatus)
338 	       & AGP_MODE_GET_FW(mstatus)
339 	       & AGP_MODE_GET_FW(mode));
340 
341 	/* Figure out the max rate */
342 	rate = (AGP_MODE_GET_RATE(tstatus)
343 		& AGP_MODE_GET_RATE(mstatus)
344 		& AGP_MODE_GET_RATE(mode));
345 	if (rate & AGP_MODE_V3_RATE_8x)
346 		rate = AGP_MODE_V3_RATE_8x;
347 	else
348 		rate = AGP_MODE_V3_RATE_4x;
349 	if (bootverbose)
350 		device_printf(dev, "Setting AGP v3 mode %d\n", rate * 4);
351 
352 	pci_write_config(dev, agp_find_caps(dev) + AGP_COMMAND, 0, 4);
353 
354 	/* Construct the new mode word and tell the hardware */
355 	command = 0;
356 	command = AGP_MODE_SET_RQ(0, rq);
357 	command = AGP_MODE_SET_ARQSZ(command, arqsz);
358 	command = AGP_MODE_SET_CAL(command, cal);
359 	command = AGP_MODE_SET_SBA(command, sba);
360 	command = AGP_MODE_SET_FW(command, fw);
361 	command = AGP_MODE_SET_RATE(command, rate);
362 	command = AGP_MODE_SET_MODE_3(command, 1);
363 	command = AGP_MODE_SET_AGP(command, 1);
364 	pci_write_config(dev, agp_find_caps(dev) + AGP_COMMAND, command, 4);
365 	pci_write_config(mdev, agp_find_caps(mdev) + AGP_COMMAND, command, 4);
366 
367 	return 0;
368 }
369 
370 static int
371 agp_v2_enable(device_t dev, device_t mdev, u_int32_t mode)
372 {
373 	u_int32_t tstatus, mstatus;
374 	u_int32_t command;
375 	int rq, sba, fw, rate;
376 
377 	tstatus = pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
378 	mstatus = pci_read_config(mdev, agp_find_caps(mdev) + AGP_STATUS, 4);
379 
380 	/* Set RQ to the min of mode, tstatus and mstatus */
381 	rq = AGP_MODE_GET_RQ(mode);
382 	if (AGP_MODE_GET_RQ(tstatus) < rq)
383 		rq = AGP_MODE_GET_RQ(tstatus);
384 	if (AGP_MODE_GET_RQ(mstatus) < rq)
385 		rq = AGP_MODE_GET_RQ(mstatus);
386 
387 	/* Set SBA if all three can deal with SBA */
388 	sba = (AGP_MODE_GET_SBA(tstatus)
389 	       & AGP_MODE_GET_SBA(mstatus)
390 	       & AGP_MODE_GET_SBA(mode));
391 
392 	/* Similar for FW */
393 	fw = (AGP_MODE_GET_FW(tstatus)
394 	       & AGP_MODE_GET_FW(mstatus)
395 	       & AGP_MODE_GET_FW(mode));
396 
397 	/* Figure out the max rate */
398 	rate = (AGP_MODE_GET_RATE(tstatus)
399 		& AGP_MODE_GET_RATE(mstatus)
400 		& AGP_MODE_GET_RATE(mode));
401 	if (rate & AGP_MODE_V2_RATE_4x)
402 		rate = AGP_MODE_V2_RATE_4x;
403 	else if (rate & AGP_MODE_V2_RATE_2x)
404 		rate = AGP_MODE_V2_RATE_2x;
405 	else
406 		rate = AGP_MODE_V2_RATE_1x;
407 	if (bootverbose)
408 		device_printf(dev, "Setting AGP v2 mode %d\n", rate);
409 
410 	/* Construct the new mode word and tell the hardware */
411 	command = 0;
412 	command = AGP_MODE_SET_RQ(0, rq);
413 	command = AGP_MODE_SET_SBA(command, sba);
414 	command = AGP_MODE_SET_FW(command, fw);
415 	command = AGP_MODE_SET_RATE(command, rate);
416 	command = AGP_MODE_SET_AGP(command, 1);
417 	pci_write_config(dev, agp_find_caps(dev) + AGP_COMMAND, command, 4);
418 	pci_write_config(mdev, agp_find_caps(mdev) + AGP_COMMAND, command, 4);
419 
420 	return 0;
421 }
422 
423 int
424 agp_generic_enable(device_t dev, u_int32_t mode)
425 {
426 	device_t mdev = agp_find_display();
427 	u_int32_t tstatus, mstatus;
428 
429 	if (!mdev) {
430 		AGP_DPF("can't find display\n");
431 		return ENXIO;
432 	}
433 
434 	tstatus = pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
435 	mstatus = pci_read_config(mdev, agp_find_caps(mdev) + AGP_STATUS, 4);
436 
437 	/*
438 	 * Check display and bridge for AGP v3 support.  AGP v3 allows
439 	 * more variety in topology than v2, e.g. multiple AGP devices
440 	 * attached to one bridge, or multiple AGP bridges in one
441 	 * system.  This doesn't attempt to address those situations,
442 	 * but should work fine for a classic single AGP slot system
443 	 * with AGP v3.
444 	 */
445 	if (AGP_MODE_GET_MODE_3(mode) &&
446 	    AGP_MODE_GET_MODE_3(tstatus) &&
447 	    AGP_MODE_GET_MODE_3(mstatus))
448 		return (agp_v3_enable(dev, mdev, mode));
449 	else
450 		return (agp_v2_enable(dev, mdev, mode));
451 }
452 
453 struct agp_memory *
454 agp_generic_alloc_memory(device_t dev, int type, vm_size_t size)
455 {
456 	struct agp_softc *sc = device_get_softc(dev);
457 	struct agp_memory *mem;
458 
459 	if ((size & (AGP_PAGE_SIZE - 1)) != 0)
460 		return 0;
461 
462 	if (sc->as_allocated + size > sc->as_maxmem)
463 		return 0;
464 
465 	if (type != 0) {
466 		kprintf("agp_generic_alloc_memory: unsupported type %d\n",
467 			type);
468 		return 0;
469 	}
470 
471 	mem = kmalloc(sizeof *mem, M_AGP, M_INTWAIT);
472 	mem->am_id = sc->as_nextid++;
473 	mem->am_size = size;
474 	mem->am_type = 0;
475 	mem->am_obj = vm_object_allocate(OBJT_DEFAULT, atop(round_page(size)));
476 	mem->am_physical = 0;
477 	mem->am_offset = 0;
478 	mem->am_is_bound = 0;
479 	TAILQ_INSERT_TAIL(&sc->as_memory, mem, am_link);
480 	sc->as_allocated += size;
481 
482 	return mem;
483 }
484 
485 int
486 agp_generic_free_memory(device_t dev, struct agp_memory *mem)
487 {
488 	struct agp_softc *sc = device_get_softc(dev);
489 
490 	if (mem->am_is_bound)
491 		return EBUSY;
492 
493 	sc->as_allocated -= mem->am_size;
494 	TAILQ_REMOVE(&sc->as_memory, mem, am_link);
495 	vm_object_deallocate(mem->am_obj);
496 	kfree(mem, M_AGP);
497 	return 0;
498 }
499 
500 int
501 agp_generic_bind_memory(device_t dev, struct agp_memory *mem,
502 			vm_offset_t offset)
503 {
504 	struct agp_softc *sc = device_get_softc(dev);
505 	vm_offset_t i, j, k;
506 	vm_page_t m;
507 	int error;
508 
509 	lockmgr(&sc->as_lock, LK_EXCLUSIVE);
510 
511 	if (mem->am_is_bound) {
512 		device_printf(dev, "memory already bound\n");
513 		lockmgr(&sc->as_lock, LK_RELEASE);
514 		return EINVAL;
515 	}
516 
517 	if (offset < 0
518 	    || (offset & (AGP_PAGE_SIZE - 1)) != 0
519 	    || offset + mem->am_size > AGP_GET_APERTURE(dev)) {
520 		device_printf(dev, "binding memory at bad offset %#x,%#x,%#x\n",
521 			      (int) offset, (int)mem->am_size,
522 			      (int)AGP_GET_APERTURE(dev));
523 		kprintf("Check BIOS's aperature size vs X\n");
524 		lockmgr(&sc->as_lock, LK_RELEASE);
525 		return EINVAL;
526 	}
527 
528 	/*
529 	 * Bind the individual pages and flush the chipset's
530 	 * TLB.
531 	 */
532 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
533 		/*
534 		 * Find a page from the object and wire it down. This page
535 		 * will be mapped using one or more entries in the GATT
536 		 * (assuming that PAGE_SIZE >= AGP_PAGE_SIZE. If this is
537 		 * the first call to bind, the pages will be allocated
538 		 * and zeroed.
539 		 */
540 		m = vm_page_grab(mem->am_obj, OFF_TO_IDX(i),
541 				 VM_ALLOC_NORMAL | VM_ALLOC_ZERO |
542 				 VM_ALLOC_RETRY);
543 		AGP_DPF("found page pa=%#x\n", VM_PAGE_TO_PHYS(m));
544 		vm_page_wire(m);
545 
546 		/*
547 		 * Install entries in the GATT, making sure that if
548 		 * AGP_PAGE_SIZE < PAGE_SIZE and mem->am_size is not
549 		 * aligned to PAGE_SIZE, we don't modify too many GATT
550 		 * entries.
551 		 */
552 		for (j = 0; j < PAGE_SIZE && i + j < mem->am_size;
553 		     j += AGP_PAGE_SIZE) {
554 			vm_offset_t pa = VM_PAGE_TO_PHYS(m) + j;
555 			AGP_DPF("binding offset %#x to pa %#x\n",
556 				offset + i + j, pa);
557 			error = AGP_BIND_PAGE(dev, offset + i + j, pa);
558 			if (error) {
559 				/*
560 				 * Bail out. Reverse all the mappings
561 				 * and unwire the pages.
562 				 */
563 				vm_page_wakeup(m);
564 				for (k = 0; k < i + j; k += AGP_PAGE_SIZE)
565 					AGP_UNBIND_PAGE(dev, offset + k);
566 				vm_object_hold(mem->am_obj);
567 				for (k = 0; k <= i; k += PAGE_SIZE) {
568 					m = vm_page_lookup_busy_wait(
569 						mem->am_obj, OFF_TO_IDX(k),
570 						FALSE, "agppg");
571 					vm_page_unwire(m, 0);
572 					vm_page_wakeup(m);
573 				}
574 				vm_object_drop(mem->am_obj);
575 				lockmgr(&sc->as_lock, LK_RELEASE);
576 				return error;
577 			}
578 		}
579 		vm_page_wakeup(m);
580 	}
581 
582 	/*
583 	 * Flush the cpu cache since we are providing a new mapping
584 	 * for these pages.
585 	 */
586 	agp_flush_cache();
587 
588 	/*
589 	 * Make sure the chipset gets the new mappings.
590 	 */
591 	AGP_FLUSH_TLB(dev);
592 
593 	mem->am_offset = offset;
594 	mem->am_is_bound = 1;
595 
596 	lockmgr(&sc->as_lock, LK_RELEASE);
597 
598 	return 0;
599 }
600 
601 int
602 agp_generic_unbind_memory(device_t dev, struct agp_memory *mem)
603 {
604 	struct agp_softc *sc = device_get_softc(dev);
605 	vm_page_t m;
606 	int i;
607 
608 	lockmgr(&sc->as_lock, LK_EXCLUSIVE);
609 
610 	if (!mem->am_is_bound) {
611 		device_printf(dev, "memory is not bound\n");
612 		lockmgr(&sc->as_lock, LK_RELEASE);
613 		return EINVAL;
614 	}
615 
616 
617 	/*
618 	 * Unbind the individual pages and flush the chipset's
619 	 * TLB. Unwire the pages so they can be swapped.
620 	 */
621 	for (i = 0; i < mem->am_size; i += AGP_PAGE_SIZE)
622 		AGP_UNBIND_PAGE(dev, mem->am_offset + i);
623 	vm_object_hold(mem->am_obj);
624 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
625 		m = vm_page_lookup_busy_wait(mem->am_obj, atop(i),
626 					     FALSE, "agppg");
627 		vm_page_unwire(m, 0);
628 		vm_page_wakeup(m);
629 	}
630 	vm_object_drop(mem->am_obj);
631 
632 	agp_flush_cache();
633 	AGP_FLUSH_TLB(dev);
634 
635 	mem->am_offset = 0;
636 	mem->am_is_bound = 0;
637 
638 	lockmgr(&sc->as_lock, LK_RELEASE);
639 
640 	return 0;
641 }
642 
643 /* Helper functions for implementing user/kernel api */
644 
645 static int
646 agp_acquire_helper(device_t dev, enum agp_acquire_state state)
647 {
648 	struct agp_softc *sc = device_get_softc(dev);
649 
650 	if (sc->as_state != AGP_ACQUIRE_FREE)
651 		return EBUSY;
652 	sc->as_state = state;
653 
654 	return 0;
655 }
656 
657 static int
658 agp_release_helper(device_t dev, enum agp_acquire_state state)
659 {
660 	struct agp_softc *sc = device_get_softc(dev);
661 
662 	if (sc->as_state == AGP_ACQUIRE_FREE)
663 		return 0;
664 
665 	if (sc->as_state != state)
666 		return EBUSY;
667 
668 	sc->as_state = AGP_ACQUIRE_FREE;
669 	return 0;
670 }
671 
672 static struct agp_memory *
673 agp_find_memory(device_t dev, int id)
674 {
675 	struct agp_softc *sc = device_get_softc(dev);
676 	struct agp_memory *mem;
677 
678 	AGP_DPF("searching for memory block %d\n", id);
679 	TAILQ_FOREACH(mem, &sc->as_memory, am_link) {
680 		AGP_DPF("considering memory block %d\n", mem->am_id);
681 		if (mem->am_id == id)
682 			return mem;
683 	}
684 	return 0;
685 }
686 
687 /* Implementation of the userland ioctl api */
688 
689 static int
690 agp_info_user(device_t dev, agp_info *info)
691 {
692 	struct agp_softc *sc = device_get_softc(dev);
693 
694 	bzero(info, sizeof *info);
695 	info->bridge_id = pci_get_devid(dev);
696 	info->agp_mode =
697 	    pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
698 	info->aper_base = rman_get_start(sc->as_aperture);
699 	info->aper_size = AGP_GET_APERTURE(dev) >> 20;
700 	info->pg_total = info->pg_system = sc->as_maxmem >> AGP_PAGE_SHIFT;
701 	info->pg_used = sc->as_allocated >> AGP_PAGE_SHIFT;
702 
703 	return 0;
704 }
705 
706 static int
707 agp_setup_user(device_t dev, agp_setup *setup)
708 {
709 	return AGP_ENABLE(dev, setup->agp_mode);
710 }
711 
712 static int
713 agp_allocate_user(device_t dev, agp_allocate *alloc)
714 {
715 	struct agp_memory *mem;
716 
717 	mem = AGP_ALLOC_MEMORY(dev,
718 			       alloc->type,
719 			       alloc->pg_count << AGP_PAGE_SHIFT);
720 	if (mem) {
721 		alloc->key = mem->am_id;
722 		alloc->physical = mem->am_physical;
723 		return 0;
724 	} else {
725 		return ENOMEM;
726 	}
727 }
728 
729 static int
730 agp_deallocate_user(device_t dev, int id)
731 {
732 	struct agp_memory *mem = agp_find_memory(dev, id);
733 
734 	if (mem) {
735 		AGP_FREE_MEMORY(dev, mem);
736 		return 0;
737 	} else {
738 		return ENOENT;
739 	}
740 }
741 
742 static int
743 agp_bind_user(device_t dev, agp_bind *bind)
744 {
745 	struct agp_memory *mem = agp_find_memory(dev, bind->key);
746 
747 	if (!mem)
748 		return ENOENT;
749 
750 	return AGP_BIND_MEMORY(dev, mem, bind->pg_start << AGP_PAGE_SHIFT);
751 }
752 
753 static int
754 agp_unbind_user(device_t dev, agp_unbind *unbind)
755 {
756 	struct agp_memory *mem = agp_find_memory(dev, unbind->key);
757 
758 	if (!mem)
759 		return ENOENT;
760 
761 	return AGP_UNBIND_MEMORY(dev, mem);
762 }
763 
764 static int
765 agp_open(struct dev_open_args *ap)
766 {
767 	cdev_t kdev = ap->a_head.a_dev;
768 	device_t dev = KDEV2DEV(kdev);
769 	struct agp_softc *sc = device_get_softc(dev);
770 
771 	if (!sc->as_isopen) {
772 		sc->as_isopen = 1;
773 		device_busy(dev);
774 	}
775 
776 	return 0;
777 }
778 
779 static int
780 agp_close(struct dev_close_args *ap)
781 {
782 	cdev_t kdev = ap->a_head.a_dev;
783 	device_t dev = KDEV2DEV(kdev);
784 	struct agp_softc *sc = device_get_softc(dev);
785 	struct agp_memory *mem;
786 
787 	/*
788 	 * Clear the GATT and force release on last close
789 	 */
790 	while ((mem = TAILQ_FIRST(&sc->as_memory)) != NULL) {
791 		if (mem->am_is_bound)
792 			AGP_UNBIND_MEMORY(dev, mem);
793 		AGP_FREE_MEMORY(dev, mem);
794 	}
795 	if (sc->as_state == AGP_ACQUIRE_USER)
796 		agp_release_helper(dev, AGP_ACQUIRE_USER);
797 	if (sc->as_isopen) {
798 		sc->as_isopen = 0;
799 		device_unbusy(dev);
800 	}
801 
802 	return 0;
803 }
804 
805 static int
806 agp_ioctl(struct dev_ioctl_args *ap)
807 {
808 	cdev_t kdev = ap->a_head.a_dev;
809 	device_t dev = KDEV2DEV(kdev);
810 
811 	switch (ap->a_cmd) {
812 	case AGPIOC_INFO:
813 		return agp_info_user(dev, (agp_info *)ap->a_data);
814 
815 	case AGPIOC_ACQUIRE:
816 		return agp_acquire_helper(dev, AGP_ACQUIRE_USER);
817 
818 	case AGPIOC_RELEASE:
819 		return agp_release_helper(dev, AGP_ACQUIRE_USER);
820 
821 	case AGPIOC_SETUP:
822 		return agp_setup_user(dev, (agp_setup *)ap->a_data);
823 
824 	case AGPIOC_ALLOCATE:
825 		return agp_allocate_user(dev, (agp_allocate *)ap->a_data);
826 
827 	case AGPIOC_DEALLOCATE:
828 		return agp_deallocate_user(dev, *(int *)ap->a_data);
829 
830 	case AGPIOC_BIND:
831 		return agp_bind_user(dev, (agp_bind *)ap->a_data);
832 
833 	case AGPIOC_UNBIND:
834 		return agp_unbind_user(dev, (agp_unbind *)ap->a_data);
835 
836 	}
837 
838 	return EINVAL;
839 }
840 
841 static int
842 agp_mmap(struct dev_mmap_args *ap)
843 {
844 	cdev_t kdev = ap->a_head.a_dev;
845 	device_t dev = KDEV2DEV(kdev);
846 	struct agp_softc *sc = device_get_softc(dev);
847 
848 	if (ap->a_offset > AGP_GET_APERTURE(dev))
849 		return EINVAL;
850 	ap->a_result = atop(rman_get_start(sc->as_aperture) + ap->a_offset);
851 	return 0;
852 }
853 
854 /* Implementation of the kernel api */
855 
856 device_t
857 agp_find_device(void)
858 {
859 	device_t *children, child;
860 	int i, count;
861 
862 	if (!agp_devclass)
863 		return NULL;
864 	if (devclass_get_devices(agp_devclass, &children, &count) != 0)
865 		return NULL;
866 	child = NULL;
867 	for (i = 0; i < count; i++) {
868 		if (device_is_attached(children[i])) {
869 			child = children[i];
870 			break;
871 		}
872 	}
873 	kfree(children, M_TEMP);
874 	return child;
875 }
876 
877 enum agp_acquire_state
878 agp_state(device_t dev)
879 {
880 	struct agp_softc *sc = device_get_softc(dev);
881 	return sc->as_state;
882 }
883 
884 void
885 agp_get_info(device_t dev, struct agp_info *info)
886 {
887 	struct agp_softc *sc = device_get_softc(dev);
888 
889 	info->ai_mode =
890 		pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
891 	info->ai_aperture_base = rman_get_start(sc->as_aperture);
892 	info->ai_aperture_size = rman_get_size(sc->as_aperture);
893 	info->ai_memory_allowed = sc->as_maxmem;
894 	info->ai_memory_used = sc->as_allocated;
895 }
896 
897 int
898 agp_acquire(device_t dev)
899 {
900 	return agp_acquire_helper(dev, AGP_ACQUIRE_KERNEL);
901 }
902 
903 int
904 agp_release(device_t dev)
905 {
906 	return agp_release_helper(dev, AGP_ACQUIRE_KERNEL);
907 }
908 
909 int
910 agp_enable(device_t dev, u_int32_t mode)
911 {
912 	return AGP_ENABLE(dev, mode);
913 }
914 
915 void *agp_alloc_memory(device_t dev, int type, vm_size_t bytes)
916 {
917 	return  (void *) AGP_ALLOC_MEMORY(dev, type, bytes);
918 }
919 
920 void agp_free_memory(device_t dev, void *handle)
921 {
922 	struct agp_memory *mem = (struct agp_memory *) handle;
923 	AGP_FREE_MEMORY(dev, mem);
924 }
925 
926 int agp_bind_memory(device_t dev, void *handle, vm_offset_t offset)
927 {
928 	struct agp_memory *mem = (struct agp_memory *) handle;
929 	return AGP_BIND_MEMORY(dev, mem, offset);
930 }
931 
932 int agp_unbind_memory(device_t dev, void *handle)
933 {
934 	struct agp_memory *mem = (struct agp_memory *) handle;
935 	return AGP_UNBIND_MEMORY(dev, mem);
936 }
937 
938 void agp_memory_info(device_t dev, void *handle, struct
939 		     agp_memory_info *mi)
940 {
941 	struct agp_memory *mem = (struct agp_memory *) handle;
942 
943 	mi->ami_size = mem->am_size;
944 	mi->ami_physical = mem->am_physical;
945 	mi->ami_offset = mem->am_offset;
946 	mi->ami_is_bound = mem->am_is_bound;
947 }
948