xref: /dragonfly/sys/dev/agp/agp.c (revision 4353aa4e)
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 "opt_bus.h"
30 
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/device.h>
34 #include <sys/conf.h>
35 #include <sys/malloc.h>
36 #include <sys/kernel.h>
37 #include <sys/bus.h>
38 #include <sys/agpio.h>
39 #include <sys/lock.h>
40 #include <sys/proc.h>
41 #include <sys/rman.h>
42 
43 #include <bus/pci/pcivar.h>
44 #include <bus/pci/pcireg.h>
45 #include "agppriv.h"
46 #include "agpvar.h"
47 #include "agpreg.h"
48 
49 #include <vm/vm.h>
50 #include <vm/vm_object.h>
51 #include <vm/vm_page.h>
52 #include <vm/vm_pageout.h>
53 #include <vm/pmap.h>
54 
55 #include <machine/md_var.h>
56 
57 MODULE_VERSION(agp, 1);
58 
59 MALLOC_DEFINE(M_AGP, "agp", "AGP data structures");
60 
61 static d_open_t agp_open;
62 static d_close_t agp_close;
63 static d_ioctl_t agp_ioctl;
64 static d_mmap_t agp_mmap;
65 
66 static struct dev_ops agp_ops = {
67 	{ "agp", 0, D_TTY },
68 	.d_open =	agp_open,
69 	.d_close =	agp_close,
70 	.d_ioctl =	agp_ioctl,
71 	.d_mmap =	agp_mmap,
72 };
73 
74 static devclass_t agp_devclass;
75 #define KDEV2DEV(kdev)	devclass_get_device(agp_devclass, minor(kdev))
76 
77 /* Helper functions for implementing chipset mini drivers. */
78 
79 void
80 agp_flush_cache(void)
81 {
82 #if defined(__i386__) || defined(__x86_64__)
83 	wbinvd();
84 #endif
85 }
86 
87 u_int8_t
88 agp_find_caps(device_t dev)
89 {
90 	int capreg;
91 
92 	if (pci_find_extcap(dev, PCIY_AGP, &capreg) != 0)
93 		capreg = 0;
94 	return (capreg);
95 }
96 
97 /*
98  * Find an AGP display device (if any).
99  */
100 static device_t
101 agp_find_display(void)
102 {
103 	devclass_t pci = devclass_find("pci");
104 	device_t bus, dev = 0;
105 	device_t *kids;
106 	int busnum, numkids, i;
107 
108 	for (busnum = 0; busnum < devclass_get_maxunit(pci); busnum++) {
109 		bus = devclass_get_device(pci, busnum);
110 		if (!bus)
111 			continue;
112 		device_get_children(bus, &kids, &numkids);
113 		for (i = 0; i < numkids; i++) {
114 			dev = kids[i];
115 			if (pci_get_class(dev) == PCIC_DISPLAY
116 			    && pci_get_subclass(dev) == PCIS_DISPLAY_VGA)
117 				if (agp_find_caps(dev)) {
118 					kfree(kids, M_TEMP);
119 					return dev;
120 				}
121 
122 		}
123 		kfree(kids, M_TEMP);
124 	}
125 
126 	return 0;
127 }
128 
129 struct agp_gatt *
130 agp_alloc_gatt(device_t dev)
131 {
132 	u_int32_t apsize = AGP_GET_APERTURE(dev);
133 	u_int32_t entries = apsize >> AGP_PAGE_SHIFT;
134 	struct agp_gatt *gatt;
135 
136 	if (bootverbose)
137 		device_printf(dev,
138 			      "allocating GATT for aperture of size %dM\n",
139 			      apsize / (1024*1024));
140 
141 	if (entries == 0) {
142 		device_printf(dev, "bad aperture size\n");
143 		return NULL;
144 	}
145 
146 	gatt = kmalloc(sizeof(struct agp_gatt), M_AGP, M_INTWAIT);
147 	gatt->ag_entries = entries;
148 	gatt->ag_virtual = contigmalloc(entries * sizeof(u_int32_t), M_AGP,
149 					M_WAITOK|M_ZERO, 0, ~0, PAGE_SIZE, 0);
150 	if (!gatt->ag_virtual) {
151 		if (bootverbose)
152 			device_printf(dev, "contiguous allocation failed\n");
153 		kfree(gatt, M_AGP);
154 		return 0;
155 	}
156 	gatt->ag_physical = vtophys((vm_offset_t) gatt->ag_virtual);
157 	agp_flush_cache();
158 
159 	return gatt;
160 }
161 
162 void
163 agp_free_gatt(struct agp_gatt *gatt)
164 {
165 	contigfree(gatt->ag_virtual,
166 		   gatt->ag_entries * sizeof(u_int32_t), M_AGP);
167 	kfree(gatt, M_AGP);
168 }
169 
170 static u_int agp_max[][2] = {
171 	{0,	0},
172 	{32,	4},
173 	{64,	28},
174 	{128,	96},
175 	{256,	204},
176 	{512,	440},
177 	{1024,	942},
178 	{2048,	1920},
179 	{4096,	3932}
180 };
181 #define agp_max_size	NELEM(agp_max)
182 
183 /**
184  * Sets the PCI resource which represents the AGP aperture.
185  *
186  * If not called, the default AGP aperture resource of AGP_APBASE will
187  * be used.  Must be called before agp_generic_attach().
188  */
189 void
190 agp_set_aperture_resource(device_t dev, int rid)
191 {
192 	struct agp_softc *sc = device_get_softc(dev);
193 
194 	sc->as_aperture_rid = rid;
195 }
196 
197 int
198 agp_generic_attach(device_t dev)
199 {
200 	struct agp_softc *sc = device_get_softc(dev);
201 	int i;
202 	u_int memsize;
203 
204 	/*
205 	 * Find and map the aperture, RF_SHAREABLE for DRM but not RF_ACTIVE
206 	 * because the kernel doesn't need to map it.
207 	 */
208 	if (sc->as_aperture_rid == 0)
209 		sc->as_aperture_rid = AGP_APBASE;
210 
211 	sc->as_aperture = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
212 	    &sc->as_aperture_rid, RF_SHAREABLE);
213 	if (!sc->as_aperture)
214 		return ENOMEM;
215 
216 	/*
217 	 * Work out an upper bound for agp memory allocation. This
218 	 * uses a heurisitc table from the Linux driver.
219 	 */
220 	memsize = ptoa(Maxmem) >> 20;
221 	for (i = 0; i < agp_max_size; i++) {
222 		if (memsize <= agp_max[i][0])
223 			break;
224 	}
225 	if (i == agp_max_size) i = agp_max_size - 1;
226 	sc->as_maxmem = agp_max[i][1] << 20U;
227 
228 	/*
229 	 * The lock is used to prevent re-entry to
230 	 * agp_generic_bind_memory() since that function can sleep.
231 	 */
232 	lockinit(&sc->as_lock, "agplk", 0, 0);
233 
234 	/*
235 	 * Initialise stuff for the userland device.
236 	 */
237 	agp_devclass = devclass_find("agp");
238 	TAILQ_INIT(&sc->as_memory);
239 	sc->as_nextid = 1;
240 
241 	make_dev(&agp_ops, device_get_unit(dev), UID_ROOT, GID_WHEEL,
242 		 0600, "agpgart");
243 
244 	return 0;
245 }
246 
247 void
248 agp_free_cdev(device_t dev)
249 {
250 	dev_ops_remove_minor(&agp_ops, device_get_unit(dev));
251 }
252 
253 void
254 agp_free_res(device_t dev)
255 {
256 	struct agp_softc *sc = device_get_softc(dev);
257 
258 	bus_release_resource(dev, SYS_RES_MEMORY, sc->as_aperture_rid,
259 			     sc->as_aperture);
260 	agp_flush_cache();
261 }
262 
263 int
264 agp_generic_detach(device_t dev)
265 {
266 	agp_free_cdev(dev);
267 	agp_free_res(dev);
268 	return 0;
269 }
270 
271 /**
272  * Default AGP aperture size detection which simply returns the size of
273  * the aperture's PCI resource.
274  */
275 int
276 agp_generic_get_aperture(device_t dev)
277 {
278 	struct agp_softc *sc = device_get_softc(dev);
279 
280 	return rman_get_size(sc->as_aperture);
281 }
282 
283 /**
284  * Default AGP aperture size setting function, which simply doesn't allow
285  * changes to resource size.
286  */
287 int
288 agp_generic_set_aperture(device_t dev, u_int32_t aperture)
289 {
290 	u_int32_t current_aperture;
291 
292 	current_aperture = AGP_GET_APERTURE(dev);
293 	if (current_aperture != aperture)
294 		return EINVAL;
295 	else
296 		return 0;
297 }
298 
299 /*
300  * This does the enable logic for v3, with the same topology
301  * restrictions as in place for v2 -- one bus, one device on the bus.
302  */
303 static int
304 agp_v3_enable(device_t dev, device_t mdev, u_int32_t mode)
305 {
306 	u_int32_t tstatus, mstatus;
307 	u_int32_t command;
308 	int rq, sba, fw, rate, arqsz, cal;
309 
310 	tstatus = pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
311 	mstatus = pci_read_config(mdev, agp_find_caps(mdev) + AGP_STATUS, 4);
312 
313 	/* Set RQ to the min of mode, tstatus and mstatus */
314 	rq = AGP_MODE_GET_RQ(mode);
315 	if (AGP_MODE_GET_RQ(tstatus) < rq)
316 		rq = AGP_MODE_GET_RQ(tstatus);
317 	if (AGP_MODE_GET_RQ(mstatus) < rq)
318 		rq = AGP_MODE_GET_RQ(mstatus);
319 
320 	/*
321 	 * ARQSZ - Set the value to the maximum one.
322 	 * Don't allow the mode register to override values.
323 	 */
324 	arqsz = AGP_MODE_GET_ARQSZ(mode);
325 	if (AGP_MODE_GET_ARQSZ(tstatus) > rq)
326 		rq = AGP_MODE_GET_ARQSZ(tstatus);
327 	if (AGP_MODE_GET_ARQSZ(mstatus) > rq)
328 		rq = AGP_MODE_GET_ARQSZ(mstatus);
329 
330 	/* Calibration cycle - don't allow override by mode register */
331 	cal = AGP_MODE_GET_CAL(tstatus);
332 	if (AGP_MODE_GET_CAL(mstatus) < cal)
333 		cal = AGP_MODE_GET_CAL(mstatus);
334 
335 	/* SBA must be supported for AGP v3. */
336 	sba = 1;
337 
338 	/* Set FW if all three support it. */
339 	fw = (AGP_MODE_GET_FW(tstatus)
340 	       & AGP_MODE_GET_FW(mstatus)
341 	       & AGP_MODE_GET_FW(mode));
342 
343 	/* Figure out the max rate */
344 	rate = (AGP_MODE_GET_RATE(tstatus)
345 		& AGP_MODE_GET_RATE(mstatus)
346 		& AGP_MODE_GET_RATE(mode));
347 	if (rate & AGP_MODE_V3_RATE_8x)
348 		rate = AGP_MODE_V3_RATE_8x;
349 	else
350 		rate = AGP_MODE_V3_RATE_4x;
351 	if (bootverbose)
352 		device_printf(dev, "Setting AGP v3 mode %d\n", rate * 4);
353 
354 	pci_write_config(dev, agp_find_caps(dev) + AGP_COMMAND, 0, 4);
355 
356 	/* Construct the new mode word and tell the hardware */
357 	command = 0;
358 	command = AGP_MODE_SET_RQ(0, rq);
359 	command = AGP_MODE_SET_ARQSZ(command, arqsz);
360 	command = AGP_MODE_SET_CAL(command, cal);
361 	command = AGP_MODE_SET_SBA(command, sba);
362 	command = AGP_MODE_SET_FW(command, fw);
363 	command = AGP_MODE_SET_RATE(command, rate);
364 	command = AGP_MODE_SET_MODE_3(command, 1);
365 	command = AGP_MODE_SET_AGP(command, 1);
366 	pci_write_config(dev, agp_find_caps(dev) + AGP_COMMAND, command, 4);
367 	pci_write_config(mdev, agp_find_caps(mdev) + AGP_COMMAND, command, 4);
368 
369 	return 0;
370 }
371 
372 static int
373 agp_v2_enable(device_t dev, device_t mdev, u_int32_t mode)
374 {
375 	u_int32_t tstatus, mstatus;
376 	u_int32_t command;
377 	int rq, sba, fw, rate;
378 
379 	tstatus = pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
380 	mstatus = pci_read_config(mdev, agp_find_caps(mdev) + AGP_STATUS, 4);
381 
382 	/* Set RQ to the min of mode, tstatus and mstatus */
383 	rq = AGP_MODE_GET_RQ(mode);
384 	if (AGP_MODE_GET_RQ(tstatus) < rq)
385 		rq = AGP_MODE_GET_RQ(tstatus);
386 	if (AGP_MODE_GET_RQ(mstatus) < rq)
387 		rq = AGP_MODE_GET_RQ(mstatus);
388 
389 	/* Set SBA if all three can deal with SBA */
390 	sba = (AGP_MODE_GET_SBA(tstatus)
391 	       & AGP_MODE_GET_SBA(mstatus)
392 	       & AGP_MODE_GET_SBA(mode));
393 
394 	/* Similar for FW */
395 	fw = (AGP_MODE_GET_FW(tstatus)
396 	       & AGP_MODE_GET_FW(mstatus)
397 	       & AGP_MODE_GET_FW(mode));
398 
399 	/* Figure out the max rate */
400 	rate = (AGP_MODE_GET_RATE(tstatus)
401 		& AGP_MODE_GET_RATE(mstatus)
402 		& AGP_MODE_GET_RATE(mode));
403 	if (rate & AGP_MODE_V2_RATE_4x)
404 		rate = AGP_MODE_V2_RATE_4x;
405 	else if (rate & AGP_MODE_V2_RATE_2x)
406 		rate = AGP_MODE_V2_RATE_2x;
407 	else
408 		rate = AGP_MODE_V2_RATE_1x;
409 	if (bootverbose)
410 		device_printf(dev, "Setting AGP v2 mode %d\n", rate);
411 
412 	/* Construct the new mode word and tell the hardware */
413 	command = 0;
414 	command = AGP_MODE_SET_RQ(0, rq);
415 	command = AGP_MODE_SET_SBA(command, sba);
416 	command = AGP_MODE_SET_FW(command, fw);
417 	command = AGP_MODE_SET_RATE(command, rate);
418 	command = AGP_MODE_SET_AGP(command, 1);
419 	pci_write_config(dev, agp_find_caps(dev) + AGP_COMMAND, command, 4);
420 	pci_write_config(mdev, agp_find_caps(mdev) + AGP_COMMAND, command, 4);
421 
422 	return 0;
423 }
424 
425 int
426 agp_generic_enable(device_t dev, u_int32_t mode)
427 {
428 	device_t mdev = agp_find_display();
429 	u_int32_t tstatus, mstatus;
430 
431 	if (!mdev) {
432 		AGP_DPF("can't find display\n");
433 		return ENXIO;
434 	}
435 
436 	tstatus = pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
437 	mstatus = pci_read_config(mdev, agp_find_caps(mdev) + AGP_STATUS, 4);
438 
439 	/*
440 	 * Check display and bridge for AGP v3 support.  AGP v3 allows
441 	 * more variety in topology than v2, e.g. multiple AGP devices
442 	 * attached to one bridge, or multiple AGP bridges in one
443 	 * system.  This doesn't attempt to address those situations,
444 	 * but should work fine for a classic single AGP slot system
445 	 * with AGP v3.
446 	 */
447 	if (AGP_MODE_GET_MODE_3(mode) &&
448 	    AGP_MODE_GET_MODE_3(tstatus) &&
449 	    AGP_MODE_GET_MODE_3(mstatus))
450 		return (agp_v3_enable(dev, mdev, mode));
451 	else
452 		return (agp_v2_enable(dev, mdev, mode));
453 }
454 
455 struct agp_memory *
456 agp_generic_alloc_memory(device_t dev, int type, vm_size_t size)
457 {
458 	struct agp_softc *sc = device_get_softc(dev);
459 	struct agp_memory *mem;
460 
461 	if ((size & (AGP_PAGE_SIZE - 1)) != 0)
462 		return 0;
463 
464 	if (sc->as_allocated + size > sc->as_maxmem)
465 		return 0;
466 
467 	if (type != 0) {
468 		kprintf("agp_generic_alloc_memory: unsupported type %d\n",
469 			type);
470 		return 0;
471 	}
472 
473 	mem = kmalloc(sizeof *mem, M_AGP, M_INTWAIT);
474 	mem->am_id = sc->as_nextid++;
475 	mem->am_size = size;
476 	mem->am_type = 0;
477 	mem->am_obj = vm_object_allocate(OBJT_DEFAULT, atop(round_page(size)));
478 	mem->am_physical = 0;
479 	mem->am_offset = 0;
480 	mem->am_is_bound = 0;
481 	TAILQ_INSERT_TAIL(&sc->as_memory, mem, am_link);
482 	sc->as_allocated += size;
483 
484 	return mem;
485 }
486 
487 int
488 agp_generic_free_memory(device_t dev, struct agp_memory *mem)
489 {
490 	struct agp_softc *sc = device_get_softc(dev);
491 
492 	if (mem->am_is_bound)
493 		return EBUSY;
494 
495 	sc->as_allocated -= mem->am_size;
496 	TAILQ_REMOVE(&sc->as_memory, mem, am_link);
497 	vm_object_deallocate(mem->am_obj);
498 	kfree(mem, M_AGP);
499 	return 0;
500 }
501 
502 int
503 agp_generic_bind_memory(device_t dev, struct agp_memory *mem,
504 			vm_offset_t offset)
505 {
506 	struct agp_softc *sc = device_get_softc(dev);
507 	vm_offset_t i, j, k;
508 	vm_page_t m;
509 	int error;
510 
511 	lockmgr(&sc->as_lock, LK_EXCLUSIVE);
512 
513 	if (mem->am_is_bound) {
514 		device_printf(dev, "memory already bound\n");
515 		lockmgr(&sc->as_lock, LK_RELEASE);
516 		return EINVAL;
517 	}
518 
519 	if (offset < 0
520 	    || (offset & (AGP_PAGE_SIZE - 1)) != 0
521 	    || offset + mem->am_size > AGP_GET_APERTURE(dev)) {
522 		device_printf(dev, "binding memory at bad offset %#x,%#x,%#x\n",
523 			      (int) offset, (int)mem->am_size,
524 			      (int)AGP_GET_APERTURE(dev));
525 		kprintf("Check BIOS's aperature size vs X\n");
526 		lockmgr(&sc->as_lock, LK_RELEASE);
527 		return EINVAL;
528 	}
529 
530 	/*
531 	 * Bind the individual pages and flush the chipset's
532 	 * TLB.
533 	 */
534 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
535 		/*
536 		 * Find a page from the object and wire it down. This page
537 		 * will be mapped using one or more entries in the GATT
538 		 * (assuming that PAGE_SIZE >= AGP_PAGE_SIZE. If this is
539 		 * the first call to bind, the pages will be allocated
540 		 * and zeroed.
541 		 */
542 		m = vm_page_grab(mem->am_obj, OFF_TO_IDX(i),
543 				 VM_ALLOC_NORMAL | VM_ALLOC_ZERO |
544 				 VM_ALLOC_RETRY);
545 		AGP_DPF("found page pa=%#x\n", VM_PAGE_TO_PHYS(m));
546 		vm_page_wire(m);
547 
548 		/*
549 		 * Install entries in the GATT, making sure that if
550 		 * AGP_PAGE_SIZE < PAGE_SIZE and mem->am_size is not
551 		 * aligned to PAGE_SIZE, we don't modify too many GATT
552 		 * entries.
553 		 */
554 		for (j = 0; j < PAGE_SIZE && i + j < mem->am_size;
555 		     j += AGP_PAGE_SIZE) {
556 			vm_offset_t pa = VM_PAGE_TO_PHYS(m) + j;
557 			AGP_DPF("binding offset %#x to pa %#x\n",
558 				offset + i + j, pa);
559 			error = AGP_BIND_PAGE(dev, offset + i + j, pa);
560 			if (error) {
561 				/*
562 				 * Bail out. Reverse all the mappings
563 				 * and unwire the pages.
564 				 */
565 				vm_page_wakeup(m);
566 				for (k = 0; k < i + j; k += AGP_PAGE_SIZE)
567 					AGP_UNBIND_PAGE(dev, offset + k);
568 				vm_object_hold(mem->am_obj);
569 				for (k = 0; k <= i; k += PAGE_SIZE) {
570 					m = vm_page_lookup_busy_wait(
571 						mem->am_obj, OFF_TO_IDX(k),
572 						FALSE, "agppg");
573 					vm_page_unwire(m, 0);
574 					vm_page_wakeup(m);
575 				}
576 				vm_object_drop(mem->am_obj);
577 				lockmgr(&sc->as_lock, LK_RELEASE);
578 				return error;
579 			}
580 		}
581 		vm_page_wakeup(m);
582 	}
583 
584 	/*
585 	 * Flush the cpu cache since we are providing a new mapping
586 	 * for these pages.
587 	 */
588 	agp_flush_cache();
589 
590 	/*
591 	 * Make sure the chipset gets the new mappings.
592 	 */
593 	AGP_FLUSH_TLB(dev);
594 
595 	mem->am_offset = offset;
596 	mem->am_is_bound = 1;
597 
598 	lockmgr(&sc->as_lock, LK_RELEASE);
599 
600 	return 0;
601 }
602 
603 int
604 agp_generic_unbind_memory(device_t dev, struct agp_memory *mem)
605 {
606 	struct agp_softc *sc = device_get_softc(dev);
607 	vm_page_t m;
608 	int i;
609 
610 	lockmgr(&sc->as_lock, LK_EXCLUSIVE);
611 
612 	if (!mem->am_is_bound) {
613 		device_printf(dev, "memory is not bound\n");
614 		lockmgr(&sc->as_lock, LK_RELEASE);
615 		return EINVAL;
616 	}
617 
618 
619 	/*
620 	 * Unbind the individual pages and flush the chipset's
621 	 * TLB. Unwire the pages so they can be swapped.
622 	 */
623 	for (i = 0; i < mem->am_size; i += AGP_PAGE_SIZE)
624 		AGP_UNBIND_PAGE(dev, mem->am_offset + i);
625 	vm_object_hold(mem->am_obj);
626 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
627 		m = vm_page_lookup_busy_wait(mem->am_obj, atop(i),
628 					     FALSE, "agppg");
629 		vm_page_unwire(m, 0);
630 		vm_page_wakeup(m);
631 	}
632 	vm_object_drop(mem->am_obj);
633 
634 	agp_flush_cache();
635 	AGP_FLUSH_TLB(dev);
636 
637 	mem->am_offset = 0;
638 	mem->am_is_bound = 0;
639 
640 	lockmgr(&sc->as_lock, LK_RELEASE);
641 
642 	return 0;
643 }
644 
645 /* Helper functions for implementing user/kernel api */
646 
647 static int
648 agp_acquire_helper(device_t dev, enum agp_acquire_state state)
649 {
650 	struct agp_softc *sc = device_get_softc(dev);
651 
652 	if (sc->as_state != AGP_ACQUIRE_FREE)
653 		return EBUSY;
654 	sc->as_state = state;
655 
656 	return 0;
657 }
658 
659 static int
660 agp_release_helper(device_t dev, enum agp_acquire_state state)
661 {
662 	struct agp_softc *sc = device_get_softc(dev);
663 
664 	if (sc->as_state == AGP_ACQUIRE_FREE)
665 		return 0;
666 
667 	if (sc->as_state != state)
668 		return EBUSY;
669 
670 	sc->as_state = AGP_ACQUIRE_FREE;
671 	return 0;
672 }
673 
674 static struct agp_memory *
675 agp_find_memory(device_t dev, int id)
676 {
677 	struct agp_softc *sc = device_get_softc(dev);
678 	struct agp_memory *mem;
679 
680 	AGP_DPF("searching for memory block %d\n", id);
681 	TAILQ_FOREACH(mem, &sc->as_memory, am_link) {
682 		AGP_DPF("considering memory block %d\n", mem->am_id);
683 		if (mem->am_id == id)
684 			return mem;
685 	}
686 	return 0;
687 }
688 
689 /* Implementation of the userland ioctl api */
690 
691 static int
692 agp_info_user(device_t dev, agp_info *info)
693 {
694 	struct agp_softc *sc = device_get_softc(dev);
695 
696 	bzero(info, sizeof *info);
697 	info->bridge_id = pci_get_devid(dev);
698 	info->agp_mode =
699 	    pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
700 	info->aper_base = rman_get_start(sc->as_aperture);
701 	info->aper_size = AGP_GET_APERTURE(dev) >> 20;
702 	info->pg_total = info->pg_system = sc->as_maxmem >> AGP_PAGE_SHIFT;
703 	info->pg_used = sc->as_allocated >> AGP_PAGE_SHIFT;
704 
705 	return 0;
706 }
707 
708 static int
709 agp_setup_user(device_t dev, agp_setup *setup)
710 {
711 	return AGP_ENABLE(dev, setup->agp_mode);
712 }
713 
714 static int
715 agp_allocate_user(device_t dev, agp_allocate *alloc)
716 {
717 	struct agp_memory *mem;
718 
719 	mem = AGP_ALLOC_MEMORY(dev,
720 			       alloc->type,
721 			       alloc->pg_count << AGP_PAGE_SHIFT);
722 	if (mem) {
723 		alloc->key = mem->am_id;
724 		alloc->physical = mem->am_physical;
725 		return 0;
726 	} else {
727 		return ENOMEM;
728 	}
729 }
730 
731 static int
732 agp_deallocate_user(device_t dev, int id)
733 {
734 	struct agp_memory *mem = agp_find_memory(dev, id);
735 
736 	if (mem) {
737 		AGP_FREE_MEMORY(dev, mem);
738 		return 0;
739 	} else {
740 		return ENOENT;
741 	}
742 }
743 
744 static int
745 agp_bind_user(device_t dev, agp_bind *bind)
746 {
747 	struct agp_memory *mem = agp_find_memory(dev, bind->key);
748 
749 	if (!mem)
750 		return ENOENT;
751 
752 	return AGP_BIND_MEMORY(dev, mem, bind->pg_start << AGP_PAGE_SHIFT);
753 }
754 
755 static int
756 agp_unbind_user(device_t dev, agp_unbind *unbind)
757 {
758 	struct agp_memory *mem = agp_find_memory(dev, unbind->key);
759 
760 	if (!mem)
761 		return ENOENT;
762 
763 	return AGP_UNBIND_MEMORY(dev, mem);
764 }
765 
766 static int
767 agp_open(struct dev_open_args *ap)
768 {
769 	cdev_t kdev = ap->a_head.a_dev;
770 	device_t dev = KDEV2DEV(kdev);
771 	struct agp_softc *sc = device_get_softc(dev);
772 
773 	if (!sc->as_isopen) {
774 		sc->as_isopen = 1;
775 		device_busy(dev);
776 	}
777 
778 	return 0;
779 }
780 
781 static int
782 agp_close(struct dev_close_args *ap)
783 {
784 	cdev_t kdev = ap->a_head.a_dev;
785 	device_t dev = KDEV2DEV(kdev);
786 	struct agp_softc *sc = device_get_softc(dev);
787 	struct agp_memory *mem;
788 
789 	/*
790 	 * Clear the GATT and force release on last close
791 	 */
792 	while ((mem = TAILQ_FIRST(&sc->as_memory)) != NULL) {
793 		if (mem->am_is_bound)
794 			AGP_UNBIND_MEMORY(dev, mem);
795 		AGP_FREE_MEMORY(dev, mem);
796 	}
797 	if (sc->as_state == AGP_ACQUIRE_USER)
798 		agp_release_helper(dev, AGP_ACQUIRE_USER);
799 	sc->as_isopen = 0;
800 	device_unbusy(dev);
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