xref: /freebsd/sys/dev/agp/agp.c (revision 3193579b66fd7067f898dbc54bdea81a0e6f9bd0)
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 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include "opt_bus.h"
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/malloc.h>
35 #include <sys/kernel.h>
36 #include <sys/bus.h>
37 #include <sys/conf.h>
38 #include <sys/ioccom.h>
39 #include <sys/agpio.h>
40 #include <sys/lock.h>
41 #include <sys/lockmgr.h>
42 #include <sys/mutex.h>
43 #include <sys/proc.h>
44 
45 #include <dev/pci/pcivar.h>
46 #include <dev/pci/pcireg.h>
47 #include <pci/agppriv.h>
48 #include <pci/agpvar.h>
49 #include <pci/agpreg.h>
50 
51 #include <vm/vm.h>
52 #include <vm/vm_object.h>
53 #include <vm/vm_page.h>
54 #include <vm/vm_pageout.h>
55 #include <vm/pmap.h>
56 
57 #include <machine/md_var.h>
58 #include <machine/bus.h>
59 #include <machine/resource.h>
60 #include <sys/rman.h>
61 
62 MODULE_VERSION(agp, 1);
63 
64 MALLOC_DEFINE(M_AGP, "agp", "AGP data structures");
65 
66 #define CDEV_MAJOR	148
67 				/* agp_drv.c */
68 static d_open_t agp_open;
69 static d_close_t agp_close;
70 static d_ioctl_t agp_ioctl;
71 static d_mmap_t agp_mmap;
72 
73 static struct cdevsw agp_cdevsw = {
74 	.d_open =	agp_open,
75 	.d_close =	agp_close,
76 	.d_ioctl =	agp_ioctl,
77 	.d_mmap =	agp_mmap,
78 	.d_name =	"agp",
79 	.d_maj =	CDEV_MAJOR,
80 	.d_flags =	D_TTY,
81 };
82 
83 static devclass_t agp_devclass;
84 #define KDEV2DEV(kdev)	devclass_get_device(agp_devclass, minor(kdev))
85 
86 /* Helper functions for implementing chipset mini drivers. */
87 
88 void
89 agp_flush_cache()
90 {
91 #ifdef __i386__
92 	wbinvd();
93 #endif
94 #ifdef __alpha__
95 	/* FIXME: This is most likely not correct as it doesn't flush CPU
96 	 * write caches, but we don't have a facility to do that and
97 	 * this is all linux does, too */
98 	alpha_mb();
99 #endif
100 }
101 
102 u_int8_t
103 agp_find_caps(device_t dev)
104 {
105 	u_int32_t status;
106 	u_int8_t ptr, next;
107 
108 	/*
109 	 * Check the CAP_LIST bit of the PCI status register first.
110 	 */
111 	status = pci_read_config(dev, PCIR_STATUS, 2);
112 	if (!(status & 0x10))
113 		return 0;
114 
115 	/*
116 	 * Traverse the capabilities list.
117 	 */
118 	for (ptr = pci_read_config(dev, AGP_CAPPTR, 1);
119 	     ptr != 0;
120 	     ptr = next) {
121 		u_int32_t capid = pci_read_config(dev, ptr, 4);
122 		next = AGP_CAPID_GET_NEXT_PTR(capid);
123 
124 		/*
125 		 * If this capability entry ID is 2, then we are done.
126 		 */
127 		if (AGP_CAPID_GET_CAP_ID(capid) == 2)
128 			return ptr;
129 	}
130 
131 	return 0;
132 }
133 
134 /*
135  * Find an AGP display device (if any).
136  */
137 static device_t
138 agp_find_display(void)
139 {
140 	devclass_t pci = devclass_find("pci");
141 	device_t bus, dev = 0;
142 	device_t *kids;
143 	int busnum, numkids, i;
144 
145 	for (busnum = 0; busnum < devclass_get_maxunit(pci); busnum++) {
146 		bus = devclass_get_device(pci, busnum);
147 		if (!bus)
148 			continue;
149 		device_get_children(bus, &kids, &numkids);
150 		for (i = 0; i < numkids; i++) {
151 			dev = kids[i];
152 			if (pci_get_class(dev) == PCIC_DISPLAY
153 			    && pci_get_subclass(dev) == PCIS_DISPLAY_VGA)
154 				if (agp_find_caps(dev)) {
155 					free(kids, M_TEMP);
156 					return dev;
157 				}
158 
159 		}
160 		free(kids, M_TEMP);
161 	}
162 
163 	return 0;
164 }
165 
166 struct agp_gatt *
167 agp_alloc_gatt(device_t dev)
168 {
169 	u_int32_t apsize = AGP_GET_APERTURE(dev);
170 	u_int32_t entries = apsize >> AGP_PAGE_SHIFT;
171 	struct agp_gatt *gatt;
172 
173 	if (bootverbose)
174 		device_printf(dev,
175 			      "allocating GATT for aperture of size %dM\n",
176 			      apsize / (1024*1024));
177 
178 	if (entries == 0) {
179 		device_printf(dev, "bad aperture size\n");
180 		return NULL;
181 	}
182 
183 	gatt = malloc(sizeof(struct agp_gatt), M_AGP, M_NOWAIT);
184 	if (!gatt)
185 		return 0;
186 
187 	gatt->ag_entries = entries;
188 	gatt->ag_virtual = contigmalloc(entries * sizeof(u_int32_t), M_AGP, 0,
189 					0, ~0, PAGE_SIZE, 0);
190 	if (!gatt->ag_virtual) {
191 		if (bootverbose)
192 			device_printf(dev, "contiguous allocation failed\n");
193 		free(gatt, M_AGP);
194 		return 0;
195 	}
196 	bzero(gatt->ag_virtual, entries * sizeof(u_int32_t));
197 	gatt->ag_physical = vtophys((vm_offset_t) gatt->ag_virtual);
198 	agp_flush_cache();
199 
200 	return gatt;
201 }
202 
203 void
204 agp_free_gatt(struct agp_gatt *gatt)
205 {
206 	contigfree(gatt->ag_virtual,
207 		   gatt->ag_entries * sizeof(u_int32_t), M_AGP);
208 	free(gatt, M_AGP);
209 }
210 
211 static int agp_max[][2] = {
212 	{0,	0},
213 	{32,	4},
214 	{64,	28},
215 	{128,	96},
216 	{256,	204},
217 	{512,	440},
218 	{1024,	942},
219 	{2048,	1920},
220 	{4096,	3932}
221 };
222 #define agp_max_size	(sizeof(agp_max) / sizeof(agp_max[0]))
223 
224 int
225 agp_generic_attach(device_t dev)
226 {
227 	struct agp_softc *sc = device_get_softc(dev);
228 	int rid, memsize, i;
229 
230 	/*
231 	 * Find and map the aperture.
232 	 */
233 	rid = AGP_APBASE;
234 	sc->as_aperture = bus_alloc_resource(dev, SYS_RES_MEMORY, &rid,
235 					     0, ~0, 1, RF_ACTIVE);
236 	if (!sc->as_aperture)
237 		return ENOMEM;
238 
239 	/*
240 	 * Work out an upper bound for agp memory allocation. This
241 	 * uses a heurisitc table from the Linux driver.
242 	 */
243 	memsize = ptoa(Maxmem) >> 20;
244 	for (i = 0; i < agp_max_size; i++) {
245 		if (memsize <= agp_max[i][0])
246 			break;
247 	}
248 	if (i == agp_max_size) i = agp_max_size - 1;
249 	sc->as_maxmem = agp_max[i][1] << 20U;
250 
251 	/*
252 	 * The lock is used to prevent re-entry to
253 	 * agp_generic_bind_memory() since that function can sleep.
254 	 */
255 	lockinit(&sc->as_lock, PZERO|PCATCH, "agplk", 0, 0);
256 
257 	/*
258 	 * Initialise stuff for the userland device.
259 	 */
260 	agp_devclass = devclass_find("agp");
261 	TAILQ_INIT(&sc->as_memory);
262 	sc->as_nextid = 1;
263 
264 	sc->as_devnode = make_dev(&agp_cdevsw,
265 				  device_get_unit(dev),
266 				  UID_ROOT,
267 				  GID_WHEEL,
268 				  0600,
269 				  "agpgart");
270 
271 	return 0;
272 }
273 
274 int
275 agp_generic_detach(device_t dev)
276 {
277 	struct agp_softc *sc = device_get_softc(dev);
278 	bus_release_resource(dev, SYS_RES_MEMORY, AGP_APBASE, sc->as_aperture);
279 	lockmgr(&sc->as_lock, LK_DRAIN, 0, curthread);
280 	lockdestroy(&sc->as_lock);
281 	destroy_dev(sc->as_devnode);
282 	agp_flush_cache();
283 	return 0;
284 }
285 
286 /*
287  * This does the enable logic for v3, with the same topology
288  * restrictions as in place for v2 -- one bus, one device on the bus.
289  */
290 static int
291 agp_v3_enable(device_t dev, device_t mdev, u_int32_t mode)
292 {
293 	u_int32_t tstatus, mstatus;
294 	u_int32_t command;
295 	int rq, sba, fw, rate, arqsz, cal;
296 
297 	tstatus = pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
298 	mstatus = pci_read_config(mdev, agp_find_caps(mdev) + AGP_STATUS, 4);
299 
300 	/* Set RQ to the min of mode, tstatus and mstatus */
301 	rq = AGP_MODE_GET_RQ(mode);
302 	if (AGP_MODE_GET_RQ(tstatus) < rq)
303 		rq = AGP_MODE_GET_RQ(tstatus);
304 	if (AGP_MODE_GET_RQ(mstatus) < rq)
305 		rq = AGP_MODE_GET_RQ(mstatus);
306 
307 	/*
308 	 * ARQSZ - Set the value to the maximum one.
309 	 * Don't allow the mode register to override values.
310 	 */
311 	arqsz = AGP_MODE_GET_ARQSZ(mode);
312 	if (AGP_MODE_GET_ARQSZ(tstatus) > rq)
313 		rq = AGP_MODE_GET_ARQSZ(tstatus);
314 	if (AGP_MODE_GET_ARQSZ(mstatus) > rq)
315 		rq = AGP_MODE_GET_ARQSZ(mstatus);
316 
317 	/* Calibration cycle - don't allow override by mode register */
318 	cal = AGP_MODE_GET_CAL(tstatus);
319 	if (AGP_MODE_GET_CAL(mstatus) < cal)
320 		cal = AGP_MODE_GET_CAL(mstatus);
321 
322 	/* SBA must be supported for AGP v3. */
323 	sba = 1;
324 
325 	/* Set FW if all three support it. */
326 	fw = (AGP_MODE_GET_FW(tstatus)
327 	       & AGP_MODE_GET_FW(mstatus)
328 	       & AGP_MODE_GET_FW(mode));
329 
330 	/* Figure out the max rate */
331 	rate = (AGP_MODE_GET_RATE(tstatus)
332 		& AGP_MODE_GET_RATE(mstatus)
333 		& AGP_MODE_GET_RATE(mode));
334 	if (rate & AGP_MODE_V3_RATE_8x)
335 		rate = AGP_MODE_V3_RATE_8x;
336 	else
337 		rate = AGP_MODE_V3_RATE_4x;
338 	if (bootverbose)
339 		device_printf(dev, "Setting AGP v3 mode %d\n", rate * 4);
340 
341 	pci_write_config(dev, agp_find_caps(dev) + AGP_COMMAND, 0, 4);
342 
343 	/* Construct the new mode word and tell the hardware */
344 	command = AGP_MODE_SET_RQ(0, rq);
345 	command = AGP_MODE_SET_ARQSZ(command, arqsz);
346 	command = AGP_MODE_SET_CAL(command, cal);
347 	command = AGP_MODE_SET_SBA(command, sba);
348 	command = AGP_MODE_SET_FW(command, fw);
349 	command = AGP_MODE_SET_RATE(command, rate);
350 	command = AGP_MODE_SET_AGP(command, 1);
351 	pci_write_config(dev, agp_find_caps(dev) + AGP_COMMAND, command, 4);
352 	pci_write_config(mdev, agp_find_caps(mdev) + AGP_COMMAND, command, 4);
353 
354 	return 0;
355 }
356 
357 static int
358 agp_v2_enable(device_t dev, device_t mdev, u_int32_t mode)
359 {
360 	u_int32_t tstatus, mstatus;
361 	u_int32_t command;
362 	int rq, sba, fw, rate;
363 
364 	tstatus = pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
365 	mstatus = pci_read_config(mdev, agp_find_caps(mdev) + AGP_STATUS, 4);
366 
367 	/* Set RQ to the min of mode, tstatus and mstatus */
368 	rq = AGP_MODE_GET_RQ(mode);
369 	if (AGP_MODE_GET_RQ(tstatus) < rq)
370 		rq = AGP_MODE_GET_RQ(tstatus);
371 	if (AGP_MODE_GET_RQ(mstatus) < rq)
372 		rq = AGP_MODE_GET_RQ(mstatus);
373 
374 	/* Set SBA if all three can deal with SBA */
375 	sba = (AGP_MODE_GET_SBA(tstatus)
376 	       & AGP_MODE_GET_SBA(mstatus)
377 	       & AGP_MODE_GET_SBA(mode));
378 
379 	/* Similar for FW */
380 	fw = (AGP_MODE_GET_FW(tstatus)
381 	       & AGP_MODE_GET_FW(mstatus)
382 	       & AGP_MODE_GET_FW(mode));
383 
384 	/* Figure out the max rate */
385 	rate = (AGP_MODE_GET_RATE(tstatus)
386 		& AGP_MODE_GET_RATE(mstatus)
387 		& AGP_MODE_GET_RATE(mode));
388 	if (rate & AGP_MODE_V2_RATE_4x)
389 		rate = AGP_MODE_V2_RATE_4x;
390 	else if (rate & AGP_MODE_V2_RATE_2x)
391 		rate = AGP_MODE_V2_RATE_2x;
392 	else
393 		rate = AGP_MODE_V2_RATE_1x;
394 	if (bootverbose)
395 		device_printf(dev, "Setting AGP v2 mode %d\n", rate);
396 
397 	/* Construct the new mode word and tell the hardware */
398 	command = AGP_MODE_SET_RQ(0, rq);
399 	command = AGP_MODE_SET_SBA(command, sba);
400 	command = AGP_MODE_SET_FW(command, fw);
401 	command = AGP_MODE_SET_RATE(command, rate);
402 	command = AGP_MODE_SET_AGP(command, 1);
403 	pci_write_config(dev, agp_find_caps(dev) + AGP_COMMAND, command, 4);
404 	pci_write_config(mdev, agp_find_caps(mdev) + AGP_COMMAND, command, 4);
405 
406 	return 0;
407 }
408 
409 int
410 agp_generic_enable(device_t dev, u_int32_t mode)
411 {
412 	device_t mdev = agp_find_display();
413 	u_int32_t tstatus, mstatus;
414 
415 	if (!mdev) {
416 		AGP_DPF("can't find display\n");
417 		return ENXIO;
418 	}
419 
420 	tstatus = pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
421 	mstatus = pci_read_config(mdev, agp_find_caps(mdev) + AGP_STATUS, 4);
422 
423 	/*
424 	 * Check display and bridge for AGP v3 support.  AGP v3 allows
425 	 * more variety in topology than v2, e.g. multiple AGP devices
426 	 * attached to one bridge, or multiple AGP bridges in one
427 	 * system.  This doesn't attempt to address those situations,
428 	 * but should work fine for a classic single AGP slot system
429 	 * with AGP v3.
430 	 */
431 	if (AGP_MODE_GET_MODE_3(tstatus) && AGP_MODE_GET_MODE_3(mstatus))
432 		return (agp_v3_enable(dev, mdev, mode));
433 	else
434 		return (agp_v2_enable(dev, mdev, mode));
435 }
436 
437 struct agp_memory *
438 agp_generic_alloc_memory(device_t dev, int type, vm_size_t size)
439 {
440 	struct agp_softc *sc = device_get_softc(dev);
441 	struct agp_memory *mem;
442 
443 	if ((size & (AGP_PAGE_SIZE - 1)) != 0)
444 		return 0;
445 
446 	if (sc->as_allocated + size > sc->as_maxmem)
447 		return 0;
448 
449 	if (type != 0) {
450 		printf("agp_generic_alloc_memory: unsupported type %d\n",
451 		       type);
452 		return 0;
453 	}
454 
455 	mem = malloc(sizeof *mem, M_AGP, M_WAITOK);
456 	mem->am_id = sc->as_nextid++;
457 	mem->am_size = size;
458 	mem->am_type = 0;
459 	mem->am_obj = vm_object_allocate(OBJT_DEFAULT, atop(round_page(size)));
460 	mem->am_physical = 0;
461 	mem->am_offset = 0;
462 	mem->am_is_bound = 0;
463 	TAILQ_INSERT_TAIL(&sc->as_memory, mem, am_link);
464 	sc->as_allocated += size;
465 
466 	return mem;
467 }
468 
469 int
470 agp_generic_free_memory(device_t dev, struct agp_memory *mem)
471 {
472 	struct agp_softc *sc = device_get_softc(dev);
473 
474 	if (mem->am_is_bound)
475 		return EBUSY;
476 
477 	sc->as_allocated -= mem->am_size;
478 	TAILQ_REMOVE(&sc->as_memory, mem, am_link);
479 	vm_object_deallocate(mem->am_obj);
480 	free(mem, M_AGP);
481 	return 0;
482 }
483 
484 int
485 agp_generic_bind_memory(device_t dev, struct agp_memory *mem,
486 			vm_offset_t offset)
487 {
488 	struct agp_softc *sc = device_get_softc(dev);
489 	vm_offset_t i, j, k;
490 	vm_page_t m;
491 	int error;
492 
493 	lockmgr(&sc->as_lock, LK_EXCLUSIVE, 0, curthread);
494 
495 	if (mem->am_is_bound) {
496 		device_printf(dev, "memory already bound\n");
497 		return EINVAL;
498 	}
499 
500 	if (offset < 0
501 	    || (offset & (AGP_PAGE_SIZE - 1)) != 0
502 	    || offset + mem->am_size > AGP_GET_APERTURE(dev)) {
503 		device_printf(dev, "binding memory at bad offset %#x\n",
504 			      (int) offset);
505 		return EINVAL;
506 	}
507 
508 	/*
509 	 * Bind the individual pages and flush the chipset's
510 	 * TLB.
511 	 *
512 	 * XXX Presumably, this needs to be the pci address on alpha
513 	 * (i.e. use alpha_XXX_dmamap()). I don't have access to any
514 	 * alpha AGP hardware to check.
515 	 */
516 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
517 		/*
518 		 * Find a page from the object and wire it
519 		 * down. This page will be mapped using one or more
520 		 * entries in the GATT (assuming that PAGE_SIZE >=
521 		 * AGP_PAGE_SIZE. If this is the first call to bind,
522 		 * the pages will be allocated and zeroed.
523 		 */
524 		VM_OBJECT_LOCK(mem->am_obj);
525 		m = vm_page_grab(mem->am_obj, OFF_TO_IDX(i),
526 		    VM_ALLOC_WIRED | VM_ALLOC_ZERO | VM_ALLOC_RETRY);
527 		VM_OBJECT_UNLOCK(mem->am_obj);
528 		if ((m->flags & PG_ZERO) == 0)
529 			pmap_zero_page(m);
530 		AGP_DPF("found page pa=%#x\n", VM_PAGE_TO_PHYS(m));
531 
532 		/*
533 		 * Install entries in the GATT, making sure that if
534 		 * AGP_PAGE_SIZE < PAGE_SIZE and mem->am_size is not
535 		 * aligned to PAGE_SIZE, we don't modify too many GATT
536 		 * entries.
537 		 */
538 		for (j = 0; j < PAGE_SIZE && i + j < mem->am_size;
539 		     j += AGP_PAGE_SIZE) {
540 			vm_offset_t pa = VM_PAGE_TO_PHYS(m) + j;
541 			AGP_DPF("binding offset %#x to pa %#x\n",
542 				offset + i + j, pa);
543 			error = AGP_BIND_PAGE(dev, offset + i + j, pa);
544 			if (error) {
545 				/*
546 				 * Bail out. Reverse all the mappings
547 				 * and unwire the pages.
548 				 */
549 				vm_page_lock_queues();
550 				vm_page_wakeup(m);
551 				vm_page_unlock_queues();
552 				for (k = 0; k < i + j; k += AGP_PAGE_SIZE)
553 					AGP_UNBIND_PAGE(dev, offset + k);
554 				VM_OBJECT_LOCK(mem->am_obj);
555 				for (k = 0; k <= i; k += PAGE_SIZE) {
556 					m = vm_page_lookup(mem->am_obj,
557 							   OFF_TO_IDX(k));
558 					vm_page_lock_queues();
559 					vm_page_unwire(m, 0);
560 					vm_page_unlock_queues();
561 				}
562 				VM_OBJECT_UNLOCK(mem->am_obj);
563 				lockmgr(&sc->as_lock, LK_RELEASE, 0, curthread);
564 				return error;
565 			}
566 		}
567 		vm_page_lock_queues();
568 		vm_page_wakeup(m);
569 		vm_page_unlock_queues();
570 	}
571 
572 	/*
573 	 * Flush the cpu cache since we are providing a new mapping
574 	 * for these pages.
575 	 */
576 	agp_flush_cache();
577 
578 	/*
579 	 * Make sure the chipset gets the new mappings.
580 	 */
581 	AGP_FLUSH_TLB(dev);
582 
583 	mem->am_offset = offset;
584 	mem->am_is_bound = 1;
585 
586 	lockmgr(&sc->as_lock, LK_RELEASE, 0, curthread);
587 
588 	return 0;
589 }
590 
591 int
592 agp_generic_unbind_memory(device_t dev, struct agp_memory *mem)
593 {
594 	struct agp_softc *sc = device_get_softc(dev);
595 	vm_page_t m;
596 	int i;
597 
598 	lockmgr(&sc->as_lock, LK_EXCLUSIVE, 0, curthread);
599 
600 	if (!mem->am_is_bound) {
601 		device_printf(dev, "memory is not bound\n");
602 		return EINVAL;
603 	}
604 
605 
606 	/*
607 	 * Unbind the individual pages and flush the chipset's
608 	 * TLB. Unwire the pages so they can be swapped.
609 	 */
610 	for (i = 0; i < mem->am_size; i += AGP_PAGE_SIZE)
611 		AGP_UNBIND_PAGE(dev, mem->am_offset + i);
612 	VM_OBJECT_LOCK(mem->am_obj);
613 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
614 		m = vm_page_lookup(mem->am_obj, atop(i));
615 		vm_page_lock_queues();
616 		vm_page_unwire(m, 0);
617 		vm_page_unlock_queues();
618 	}
619 	VM_OBJECT_UNLOCK(mem->am_obj);
620 
621 	agp_flush_cache();
622 	AGP_FLUSH_TLB(dev);
623 
624 	mem->am_offset = 0;
625 	mem->am_is_bound = 0;
626 
627 	lockmgr(&sc->as_lock, LK_RELEASE, 0, curthread);
628 
629 	return 0;
630 }
631 
632 /* Helper functions for implementing user/kernel api */
633 
634 static int
635 agp_acquire_helper(device_t dev, enum agp_acquire_state state)
636 {
637 	struct agp_softc *sc = device_get_softc(dev);
638 
639 	if (sc->as_state != AGP_ACQUIRE_FREE)
640 		return EBUSY;
641 	sc->as_state = state;
642 
643 	return 0;
644 }
645 
646 static int
647 agp_release_helper(device_t dev, enum agp_acquire_state state)
648 {
649 	struct agp_softc *sc = device_get_softc(dev);
650 
651 	if (sc->as_state == AGP_ACQUIRE_FREE)
652 		return 0;
653 
654 	if (sc->as_state != state)
655 		return EBUSY;
656 
657 	sc->as_state = AGP_ACQUIRE_FREE;
658 	return 0;
659 }
660 
661 static struct agp_memory *
662 agp_find_memory(device_t dev, int id)
663 {
664 	struct agp_softc *sc = device_get_softc(dev);
665 	struct agp_memory *mem;
666 
667 	AGP_DPF("searching for memory block %d\n", id);
668 	TAILQ_FOREACH(mem, &sc->as_memory, am_link) {
669 		AGP_DPF("considering memory block %d\n", mem->am_id);
670 		if (mem->am_id == id)
671 			return mem;
672 	}
673 	return 0;
674 }
675 
676 /* Implementation of the userland ioctl api */
677 
678 static int
679 agp_info_user(device_t dev, agp_info *info)
680 {
681 	struct agp_softc *sc = device_get_softc(dev);
682 
683 	bzero(info, sizeof *info);
684 	info->bridge_id = pci_get_devid(dev);
685 	info->agp_mode =
686 	    pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
687 	info->aper_base = rman_get_start(sc->as_aperture);
688 	info->aper_size = AGP_GET_APERTURE(dev) >> 20;
689 	info->pg_total = info->pg_system = sc->as_maxmem >> AGP_PAGE_SHIFT;
690 	info->pg_used = sc->as_allocated >> AGP_PAGE_SHIFT;
691 
692 	return 0;
693 }
694 
695 static int
696 agp_setup_user(device_t dev, agp_setup *setup)
697 {
698 	return AGP_ENABLE(dev, setup->agp_mode);
699 }
700 
701 static int
702 agp_allocate_user(device_t dev, agp_allocate *alloc)
703 {
704 	struct agp_memory *mem;
705 
706 	mem = AGP_ALLOC_MEMORY(dev,
707 			       alloc->type,
708 			       alloc->pg_count << AGP_PAGE_SHIFT);
709 	if (mem) {
710 		alloc->key = mem->am_id;
711 		alloc->physical = mem->am_physical;
712 		return 0;
713 	} else {
714 		return ENOMEM;
715 	}
716 }
717 
718 static int
719 agp_deallocate_user(device_t dev, int id)
720 {
721 	struct agp_memory *mem = agp_find_memory(dev, id);;
722 
723 	if (mem) {
724 		AGP_FREE_MEMORY(dev, mem);
725 		return 0;
726 	} else {
727 		return ENOENT;
728 	}
729 }
730 
731 static int
732 agp_bind_user(device_t dev, agp_bind *bind)
733 {
734 	struct agp_memory *mem = agp_find_memory(dev, bind->key);
735 
736 	if (!mem)
737 		return ENOENT;
738 
739 	return AGP_BIND_MEMORY(dev, mem, bind->pg_start << AGP_PAGE_SHIFT);
740 }
741 
742 static int
743 agp_unbind_user(device_t dev, agp_unbind *unbind)
744 {
745 	struct agp_memory *mem = agp_find_memory(dev, unbind->key);
746 
747 	if (!mem)
748 		return ENOENT;
749 
750 	return AGP_UNBIND_MEMORY(dev, mem);
751 }
752 
753 static int
754 agp_open(dev_t kdev, int oflags, int devtype, struct thread *td)
755 {
756 	device_t dev = KDEV2DEV(kdev);
757 	struct agp_softc *sc = device_get_softc(dev);
758 
759 	if (!sc->as_isopen) {
760 		sc->as_isopen = 1;
761 		device_busy(dev);
762 	}
763 
764 	return 0;
765 }
766 
767 static int
768 agp_close(dev_t kdev, int fflag, int devtype, struct thread *td)
769 {
770 	device_t dev = KDEV2DEV(kdev);
771 	struct agp_softc *sc = device_get_softc(dev);
772 	struct agp_memory *mem;
773 
774 	/*
775 	 * Clear the GATT and force release on last close
776 	 */
777 	while ((mem = TAILQ_FIRST(&sc->as_memory)) != 0) {
778 		if (mem->am_is_bound)
779 			AGP_UNBIND_MEMORY(dev, mem);
780 		AGP_FREE_MEMORY(dev, mem);
781 	}
782 	if (sc->as_state == AGP_ACQUIRE_USER)
783 		agp_release_helper(dev, AGP_ACQUIRE_USER);
784 	sc->as_isopen = 0;
785 	device_unbusy(dev);
786 
787 	return 0;
788 }
789 
790 static int
791 agp_ioctl(dev_t kdev, u_long cmd, caddr_t data, int fflag, struct thread *td)
792 {
793 	device_t dev = KDEV2DEV(kdev);
794 
795 	switch (cmd) {
796 	case AGPIOC_INFO:
797 		return agp_info_user(dev, (agp_info *) data);
798 
799 	case AGPIOC_ACQUIRE:
800 		return agp_acquire_helper(dev, AGP_ACQUIRE_USER);
801 
802 	case AGPIOC_RELEASE:
803 		return agp_release_helper(dev, AGP_ACQUIRE_USER);
804 
805 	case AGPIOC_SETUP:
806 		return agp_setup_user(dev, (agp_setup *)data);
807 
808 	case AGPIOC_ALLOCATE:
809 		return agp_allocate_user(dev, (agp_allocate *)data);
810 
811 	case AGPIOC_DEALLOCATE:
812 		return agp_deallocate_user(dev, *(int *) data);
813 
814 	case AGPIOC_BIND:
815 		return agp_bind_user(dev, (agp_bind *)data);
816 
817 	case AGPIOC_UNBIND:
818 		return agp_unbind_user(dev, (agp_unbind *)data);
819 
820 	}
821 
822 	return EINVAL;
823 }
824 
825 static int
826 agp_mmap(dev_t kdev, vm_offset_t offset, vm_paddr_t *paddr, int prot)
827 {
828 	device_t dev = KDEV2DEV(kdev);
829 	struct agp_softc *sc = device_get_softc(dev);
830 
831 	if (offset > AGP_GET_APERTURE(dev))
832 		return -1;
833 	*paddr = rman_get_start(sc->as_aperture) + offset;
834 	return 0;
835 }
836 
837 /* Implementation of the kernel api */
838 
839 device_t
840 agp_find_device()
841 {
842 	if (!agp_devclass)
843 		return 0;
844 	return devclass_get_device(agp_devclass, 0);
845 }
846 
847 enum agp_acquire_state
848 agp_state(device_t dev)
849 {
850 	struct agp_softc *sc = device_get_softc(dev);
851 	return sc->as_state;
852 }
853 
854 void
855 agp_get_info(device_t dev, struct agp_info *info)
856 {
857 	struct agp_softc *sc = device_get_softc(dev);
858 
859 	info->ai_mode =
860 		pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
861 	info->ai_aperture_base = rman_get_start(sc->as_aperture);
862 	info->ai_aperture_size = rman_get_size(sc->as_aperture);
863 	info->ai_aperture_va = (vm_offset_t) rman_get_virtual(sc->as_aperture);
864 	info->ai_memory_allowed = sc->as_maxmem;
865 	info->ai_memory_used = sc->as_allocated;
866 }
867 
868 int
869 agp_acquire(device_t dev)
870 {
871 	return agp_acquire_helper(dev, AGP_ACQUIRE_KERNEL);
872 }
873 
874 int
875 agp_release(device_t dev)
876 {
877 	return agp_release_helper(dev, AGP_ACQUIRE_KERNEL);
878 }
879 
880 int
881 agp_enable(device_t dev, u_int32_t mode)
882 {
883 	return AGP_ENABLE(dev, mode);
884 }
885 
886 void *agp_alloc_memory(device_t dev, int type, vm_size_t bytes)
887 {
888 	return  (void *) AGP_ALLOC_MEMORY(dev, type, bytes);
889 }
890 
891 void agp_free_memory(device_t dev, void *handle)
892 {
893 	struct agp_memory *mem = (struct agp_memory *) handle;
894 	AGP_FREE_MEMORY(dev, mem);
895 }
896 
897 int agp_bind_memory(device_t dev, void *handle, vm_offset_t offset)
898 {
899 	struct agp_memory *mem = (struct agp_memory *) handle;
900 	return AGP_BIND_MEMORY(dev, mem, offset);
901 }
902 
903 int agp_unbind_memory(device_t dev, void *handle)
904 {
905 	struct agp_memory *mem = (struct agp_memory *) handle;
906 	return AGP_UNBIND_MEMORY(dev, mem);
907 }
908 
909 void agp_memory_info(device_t dev, void *handle, struct
910 		     agp_memory_info *mi)
911 {
912 	struct agp_memory *mem = (struct agp_memory *) handle;
913 
914 	mi->ami_size = mem->am_size;
915 	mi->ami_physical = mem->am_physical;
916 	mi->ami_offset = mem->am_offset;
917 	mi->ami_is_bound = mem->am_is_bound;
918 }
919