xref: /dflybsd-src/sys/dev/agp/agp.c (revision 330d3c4b487f3fc5d0eb023645b0b2a569f7048e)
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  *	$DragonFly: src/sys/dev/agp/agp.c,v 1.30 2008/01/07 01:34:58 corecode Exp $
28  */
29 
30 #include "opt_bus.h"
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/device.h>
35 #include <sys/conf.h>
36 #include <sys/malloc.h>
37 #include <sys/kernel.h>
38 #include <sys/bus.h>
39 #include <sys/agpio.h>
40 #include <sys/lock.h>
41 #include <sys/proc.h>
42 #include <sys/rman.h>
43 
44 #include <bus/pci/pcivar.h>
45 #include <bus/pci/pcireg.h>
46 #include "agppriv.h"
47 #include "agpvar.h"
48 #include "agpreg.h"
49 
50 #include <vm/vm.h>
51 #include <vm/vm_object.h>
52 #include <vm/vm_page.h>
53 #include <vm/vm_pageout.h>
54 #include <vm/pmap.h>
55 
56 #include <machine/md_var.h>
57 
58 MODULE_VERSION(agp, 1);
59 
60 MALLOC_DEFINE(M_AGP, "agp", "AGP data structures");
61 
62 #define CDEV_MAJOR	148
63 				/* agp_drv.c */
64 static d_open_t agp_open;
65 static d_close_t agp_close;
66 static d_ioctl_t agp_ioctl;
67 static d_mmap_t agp_mmap;
68 
69 static struct dev_ops agp_ops = {
70 	{ "agp", CDEV_MAJOR, D_TTY },
71 	.d_open =	agp_open,
72 	.d_close =	agp_close,
73 	.d_ioctl =	agp_ioctl,
74 	.d_mmap =	agp_mmap,
75 };
76 
77 static devclass_t agp_devclass;
78 #define KDEV2DEV(kdev)	devclass_get_device(agp_devclass, minor(kdev))
79 
80 /* Helper functions for implementing chipset mini drivers. */
81 
82 void
83 agp_flush_cache(void)
84 {
85 #if defined(__i386__) || defined(__x86_64__)
86 	wbinvd();
87 #endif
88 }
89 
90 u_int8_t
91 agp_find_caps(device_t dev)
92 {
93 	int capreg;
94 
95 	if (pci_find_extcap(dev, PCIY_AGP, &capreg) != 0)
96 		capreg = 0;
97 	return (capreg);
98 }
99 
100 /*
101  * Find an AGP display device (if any).
102  */
103 static device_t
104 agp_find_display(void)
105 {
106 	devclass_t pci = devclass_find("pci");
107 	device_t bus, dev = 0;
108 	device_t *kids;
109 	int busnum, numkids, i;
110 
111 	for (busnum = 0; busnum < devclass_get_maxunit(pci); busnum++) {
112 		bus = devclass_get_device(pci, busnum);
113 		if (!bus)
114 			continue;
115 		device_get_children(bus, &kids, &numkids);
116 		for (i = 0; i < numkids; i++) {
117 			dev = kids[i];
118 			if (pci_get_class(dev) == PCIC_DISPLAY
119 			    && pci_get_subclass(dev) == PCIS_DISPLAY_VGA)
120 				if (agp_find_caps(dev)) {
121 					kfree(kids, M_TEMP);
122 					return dev;
123 				}
124 
125 		}
126 		kfree(kids, M_TEMP);
127 	}
128 
129 	return 0;
130 }
131 
132 struct agp_gatt *
133 agp_alloc_gatt(device_t dev)
134 {
135 	u_int32_t apsize = AGP_GET_APERTURE(dev);
136 	u_int32_t entries = apsize >> AGP_PAGE_SHIFT;
137 	struct agp_gatt *gatt;
138 
139 	if (bootverbose)
140 		device_printf(dev,
141 			      "allocating GATT for aperture of size %dM\n",
142 			      apsize / (1024*1024));
143 
144 	if (entries == 0) {
145 		device_printf(dev, "bad aperture size\n");
146 		return NULL;
147 	}
148 
149 	gatt = kmalloc(sizeof(struct agp_gatt), M_AGP, M_INTWAIT);
150 	gatt->ag_entries = entries;
151 	gatt->ag_virtual = contigmalloc(entries * sizeof(u_int32_t), M_AGP,
152 					M_WAITOK|M_ZERO, 0, ~0, PAGE_SIZE, 0);
153 	if (!gatt->ag_virtual) {
154 		if (bootverbose)
155 			device_printf(dev, "contiguous allocation failed\n");
156 		kfree(gatt, M_AGP);
157 		return 0;
158 	}
159 	gatt->ag_physical = vtophys((vm_offset_t) gatt->ag_virtual);
160 	agp_flush_cache();
161 
162 	return gatt;
163 }
164 
165 void
166 agp_free_gatt(struct agp_gatt *gatt)
167 {
168 	contigfree(gatt->ag_virtual,
169 		   gatt->ag_entries * sizeof(u_int32_t), M_AGP);
170 	kfree(gatt, M_AGP);
171 }
172 
173 static u_int agp_max[][2] = {
174 	{0,	0},
175 	{32,	4},
176 	{64,	28},
177 	{128,	96},
178 	{256,	204},
179 	{512,	440},
180 	{1024,	942},
181 	{2048,	1920},
182 	{4096,	3932}
183 };
184 #define agp_max_size	(sizeof(agp_max) / sizeof(agp_max[0]))
185 
186 /**
187  * Sets the PCI resource which represents the AGP aperture.
188  *
189  * If not called, the default AGP aperture resource of AGP_APBASE will
190  * be used.  Must be called before agp_generic_attach().
191  */
192 void
193 agp_set_aperture_resource(device_t dev, int rid)
194 {
195 	struct agp_softc *sc = device_get_softc(dev);
196 
197 	sc->as_aperture_rid = rid;
198 }
199 
200 int
201 agp_generic_attach(device_t dev)
202 {
203 	struct agp_softc *sc = device_get_softc(dev);
204 	int i;
205 	u_int memsize;
206 
207 	/*
208 	 * Find and map the aperture, RF_SHAREABLE for DRM but not RF_ACTIVE
209 	 * because the kernel doesn't need to map it.
210 	 */
211 	if (sc->as_aperture_rid == 0)
212 		sc->as_aperture_rid = AGP_APBASE;
213 
214 	sc->as_aperture = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
215 	    &sc->as_aperture_rid, RF_SHAREABLE);
216 	if (!sc->as_aperture)
217 		return ENOMEM;
218 
219 	/*
220 	 * Work out an upper bound for agp memory allocation. This
221 	 * uses a heurisitc table from the Linux driver.
222 	 */
223 	memsize = ptoa(Maxmem) >> 20;
224 	for (i = 0; i < agp_max_size; i++) {
225 		if (memsize <= agp_max[i][0])
226 			break;
227 	}
228 	if (i == agp_max_size) i = agp_max_size - 1;
229 	sc->as_maxmem = agp_max[i][1] << 20U;
230 
231 	/*
232 	 * The lock is used to prevent re-entry to
233 	 * agp_generic_bind_memory() since that function can sleep.
234 	 */
235 	lockinit(&sc->as_lock, "agplk", 0, 0);
236 
237 	/*
238 	 * Initialise stuff for the userland device.
239 	 */
240 	agp_devclass = devclass_find("agp");
241 	TAILQ_INIT(&sc->as_memory);
242 	sc->as_nextid = 1;
243 
244 	make_dev(&agp_ops, device_get_unit(dev), UID_ROOT, GID_WHEEL,
245 		 0600, "agpgart");
246 
247 	return 0;
248 }
249 
250 void
251 agp_free_cdev(device_t dev)
252 {
253 	dev_ops_remove_minor(&agp_ops, device_get_unit(dev));
254 }
255 
256 void
257 agp_free_res(device_t dev)
258 {
259 	struct agp_softc *sc = device_get_softc(dev);
260 
261 	bus_release_resource(dev, SYS_RES_MEMORY, sc->as_aperture_rid,
262 			     sc->as_aperture);
263 	agp_flush_cache();
264 }
265 
266 int
267 agp_generic_detach(device_t dev)
268 {
269 	agp_free_cdev(dev);
270 	agp_free_res(dev);
271 	return 0;
272 }
273 
274 /**
275  * Default AGP aperture size detection which simply returns the size of
276  * the aperture's PCI resource.
277  */
278 int
279 agp_generic_get_aperture(device_t dev)
280 {
281 	struct agp_softc *sc = device_get_softc(dev);
282 
283 	return rman_get_size(sc->as_aperture);
284 }
285 
286 /**
287  * Default AGP aperture size setting function, which simply doesn't allow
288  * changes to resource size.
289  */
290 int
291 agp_generic_set_aperture(device_t dev, u_int32_t aperture)
292 {
293 	u_int32_t current_aperture;
294 
295 	current_aperture = AGP_GET_APERTURE(dev);
296 	if (current_aperture != aperture)
297 		return EINVAL;
298 	else
299 		return 0;
300 }
301 
302 /*
303  * This does the enable logic for v3, with the same topology
304  * restrictions as in place for v2 -- one bus, one device on the bus.
305  */
306 static int
307 agp_v3_enable(device_t dev, device_t mdev, u_int32_t mode)
308 {
309 	u_int32_t tstatus, mstatus;
310 	u_int32_t command;
311 	int rq, sba, fw, rate, arqsz, cal;
312 
313 	tstatus = pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
314 	mstatus = pci_read_config(mdev, agp_find_caps(mdev) + AGP_STATUS, 4);
315 
316 	/* Set RQ to the min of mode, tstatus and mstatus */
317 	rq = AGP_MODE_GET_RQ(mode);
318 	if (AGP_MODE_GET_RQ(tstatus) < rq)
319 		rq = AGP_MODE_GET_RQ(tstatus);
320 	if (AGP_MODE_GET_RQ(mstatus) < rq)
321 		rq = AGP_MODE_GET_RQ(mstatus);
322 
323 	/*
324 	 * ARQSZ - Set the value to the maximum one.
325 	 * Don't allow the mode register to override values.
326 	 */
327 	arqsz = AGP_MODE_GET_ARQSZ(mode);
328 	if (AGP_MODE_GET_ARQSZ(tstatus) > rq)
329 		rq = AGP_MODE_GET_ARQSZ(tstatus);
330 	if (AGP_MODE_GET_ARQSZ(mstatus) > rq)
331 		rq = AGP_MODE_GET_ARQSZ(mstatus);
332 
333 	/* Calibration cycle - don't allow override by mode register */
334 	cal = AGP_MODE_GET_CAL(tstatus);
335 	if (AGP_MODE_GET_CAL(mstatus) < cal)
336 		cal = AGP_MODE_GET_CAL(mstatus);
337 
338 	/* SBA must be supported for AGP v3. */
339 	sba = 1;
340 
341 	/* Set FW if all three support it. */
342 	fw = (AGP_MODE_GET_FW(tstatus)
343 	       & AGP_MODE_GET_FW(mstatus)
344 	       & AGP_MODE_GET_FW(mode));
345 
346 	/* Figure out the max rate */
347 	rate = (AGP_MODE_GET_RATE(tstatus)
348 		& AGP_MODE_GET_RATE(mstatus)
349 		& AGP_MODE_GET_RATE(mode));
350 	if (rate & AGP_MODE_V3_RATE_8x)
351 		rate = AGP_MODE_V3_RATE_8x;
352 	else
353 		rate = AGP_MODE_V3_RATE_4x;
354 	if (bootverbose)
355 		device_printf(dev, "Setting AGP v3 mode %d\n", rate * 4);
356 
357 	pci_write_config(dev, agp_find_caps(dev) + AGP_COMMAND, 0, 4);
358 
359 	/* Construct the new mode word and tell the hardware */
360 	command = 0;
361 	command = AGP_MODE_SET_RQ(0, rq);
362 	command = AGP_MODE_SET_ARQSZ(command, arqsz);
363 	command = AGP_MODE_SET_CAL(command, cal);
364 	command = AGP_MODE_SET_SBA(command, sba);
365 	command = AGP_MODE_SET_FW(command, fw);
366 	command = AGP_MODE_SET_RATE(command, rate);
367 	command = AGP_MODE_SET_MODE_3(command, 1);
368 	command = AGP_MODE_SET_AGP(command, 1);
369 	pci_write_config(dev, agp_find_caps(dev) + AGP_COMMAND, command, 4);
370 	pci_write_config(mdev, agp_find_caps(mdev) + AGP_COMMAND, command, 4);
371 
372 	return 0;
373 }
374 
375 static int
376 agp_v2_enable(device_t dev, device_t mdev, u_int32_t mode)
377 {
378 	u_int32_t tstatus, mstatus;
379 	u_int32_t command;
380 	int rq, sba, fw, rate;
381 
382 	tstatus = pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
383 	mstatus = pci_read_config(mdev, agp_find_caps(mdev) + AGP_STATUS, 4);
384 
385 	/* Set RQ to the min of mode, tstatus and mstatus */
386 	rq = AGP_MODE_GET_RQ(mode);
387 	if (AGP_MODE_GET_RQ(tstatus) < rq)
388 		rq = AGP_MODE_GET_RQ(tstatus);
389 	if (AGP_MODE_GET_RQ(mstatus) < rq)
390 		rq = AGP_MODE_GET_RQ(mstatus);
391 
392 	/* Set SBA if all three can deal with SBA */
393 	sba = (AGP_MODE_GET_SBA(tstatus)
394 	       & AGP_MODE_GET_SBA(mstatus)
395 	       & AGP_MODE_GET_SBA(mode));
396 
397 	/* Similar for FW */
398 	fw = (AGP_MODE_GET_FW(tstatus)
399 	       & AGP_MODE_GET_FW(mstatus)
400 	       & AGP_MODE_GET_FW(mode));
401 
402 	/* Figure out the max rate */
403 	rate = (AGP_MODE_GET_RATE(tstatus)
404 		& AGP_MODE_GET_RATE(mstatus)
405 		& AGP_MODE_GET_RATE(mode));
406 	if (rate & AGP_MODE_V2_RATE_4x)
407 		rate = AGP_MODE_V2_RATE_4x;
408 	else if (rate & AGP_MODE_V2_RATE_2x)
409 		rate = AGP_MODE_V2_RATE_2x;
410 	else
411 		rate = AGP_MODE_V2_RATE_1x;
412 	if (bootverbose)
413 		device_printf(dev, "Setting AGP v2 mode %d\n", rate);
414 
415 	/* Construct the new mode word and tell the hardware */
416 	command = 0;
417 	command = AGP_MODE_SET_RQ(0, rq);
418 	command = AGP_MODE_SET_SBA(command, sba);
419 	command = AGP_MODE_SET_FW(command, fw);
420 	command = AGP_MODE_SET_RATE(command, rate);
421 	command = AGP_MODE_SET_AGP(command, 1);
422 	pci_write_config(dev, agp_find_caps(dev) + AGP_COMMAND, command, 4);
423 	pci_write_config(mdev, agp_find_caps(mdev) + AGP_COMMAND, command, 4);
424 
425 	return 0;
426 }
427 
428 int
429 agp_generic_enable(device_t dev, u_int32_t mode)
430 {
431 	device_t mdev = agp_find_display();
432 	u_int32_t tstatus, mstatus;
433 
434 	if (!mdev) {
435 		AGP_DPF("can't find display\n");
436 		return ENXIO;
437 	}
438 
439 	tstatus = pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
440 	mstatus = pci_read_config(mdev, agp_find_caps(mdev) + AGP_STATUS, 4);
441 
442 	/*
443 	 * Check display and bridge for AGP v3 support.  AGP v3 allows
444 	 * more variety in topology than v2, e.g. multiple AGP devices
445 	 * attached to one bridge, or multiple AGP bridges in one
446 	 * system.  This doesn't attempt to address those situations,
447 	 * but should work fine for a classic single AGP slot system
448 	 * with AGP v3.
449 	 */
450 	if (AGP_MODE_GET_MODE_3(mode) &&
451 	    AGP_MODE_GET_MODE_3(tstatus) &&
452 	    AGP_MODE_GET_MODE_3(mstatus))
453 		return (agp_v3_enable(dev, mdev, mode));
454 	else
455 		return (agp_v2_enable(dev, mdev, mode));
456 }
457 
458 struct agp_memory *
459 agp_generic_alloc_memory(device_t dev, int type, vm_size_t size)
460 {
461 	struct agp_softc *sc = device_get_softc(dev);
462 	struct agp_memory *mem;
463 
464 	if ((size & (AGP_PAGE_SIZE - 1)) != 0)
465 		return 0;
466 
467 	if (sc->as_allocated + size > sc->as_maxmem)
468 		return 0;
469 
470 	if (type != 0) {
471 		kprintf("agp_generic_alloc_memory: unsupported type %d\n",
472 			type);
473 		return 0;
474 	}
475 
476 	mem = kmalloc(sizeof *mem, M_AGP, M_INTWAIT);
477 	mem->am_id = sc->as_nextid++;
478 	mem->am_size = size;
479 	mem->am_type = 0;
480 	mem->am_obj = vm_object_allocate(OBJT_DEFAULT, atop(round_page(size)));
481 	mem->am_physical = 0;
482 	mem->am_offset = 0;
483 	mem->am_is_bound = 0;
484 	TAILQ_INSERT_TAIL(&sc->as_memory, mem, am_link);
485 	sc->as_allocated += size;
486 
487 	return mem;
488 }
489 
490 int
491 agp_generic_free_memory(device_t dev, struct agp_memory *mem)
492 {
493 	struct agp_softc *sc = device_get_softc(dev);
494 
495 	if (mem->am_is_bound)
496 		return EBUSY;
497 
498 	sc->as_allocated -= mem->am_size;
499 	TAILQ_REMOVE(&sc->as_memory, mem, am_link);
500 	vm_object_deallocate(mem->am_obj);
501 	kfree(mem, M_AGP);
502 	return 0;
503 }
504 
505 int
506 agp_generic_bind_memory(device_t dev, struct agp_memory *mem,
507 			vm_offset_t offset)
508 {
509 	struct agp_softc *sc = device_get_softc(dev);
510 	vm_offset_t i, j, k;
511 	vm_page_t m;
512 	int error;
513 
514 	lockmgr(&sc->as_lock, LK_EXCLUSIVE);
515 
516 	if (mem->am_is_bound) {
517 		device_printf(dev, "memory already bound\n");
518 		lockmgr(&sc->as_lock, LK_RELEASE);
519 		return EINVAL;
520 	}
521 
522 	if (offset < 0
523 	    || (offset & (AGP_PAGE_SIZE - 1)) != 0
524 	    || offset + mem->am_size > AGP_GET_APERTURE(dev)) {
525 		device_printf(dev, "binding memory at bad offset %#x,%#x,%#x\n",
526 			      (int) offset, (int)mem->am_size,
527 			      (int)AGP_GET_APERTURE(dev));
528 		kprintf("Check BIOS's aperature size vs X\n");
529 		lockmgr(&sc->as_lock, LK_RELEASE);
530 		return EINVAL;
531 	}
532 
533 	/*
534 	 * Bind the individual pages and flush the chipset's
535 	 * TLB.
536 	 */
537 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
538 		/*
539 		 * Find a page from the object and wire it
540 		 * down. This page will be mapped using one or more
541 		 * entries in the GATT (assuming that PAGE_SIZE >=
542 		 * AGP_PAGE_SIZE. If this is the first call to bind,
543 		 * the pages will be allocated and zeroed.
544 		 */
545 		m = vm_page_grab(mem->am_obj, OFF_TO_IDX(i),
546 			 VM_ALLOC_NORMAL | VM_ALLOC_ZERO | VM_ALLOC_RETRY);
547 		if ((m->flags & PG_ZERO) == 0)
548 			vm_page_zero_fill(m);
549 		AGP_DPF("found page pa=%#x\n", VM_PAGE_TO_PHYS(m));
550 		vm_page_wire(m);
551 
552 		/*
553 		 * Install entries in the GATT, making sure that if
554 		 * AGP_PAGE_SIZE < PAGE_SIZE and mem->am_size is not
555 		 * aligned to PAGE_SIZE, we don't modify too many GATT
556 		 * entries.
557 		 */
558 		for (j = 0; j < PAGE_SIZE && i + j < mem->am_size;
559 		     j += AGP_PAGE_SIZE) {
560 			vm_offset_t pa = VM_PAGE_TO_PHYS(m) + j;
561 			AGP_DPF("binding offset %#x to pa %#x\n",
562 				offset + i + j, pa);
563 			error = AGP_BIND_PAGE(dev, offset + i + j, pa);
564 			if (error) {
565 				/*
566 				 * Bail out. Reverse all the mappings
567 				 * and unwire the pages.
568 				 */
569 				vm_page_wakeup(m);
570 				for (k = 0; k < i + j; k += AGP_PAGE_SIZE)
571 					AGP_UNBIND_PAGE(dev, offset + k);
572 				lwkt_gettoken(&vm_token);
573 				for (k = 0; k <= i; k += PAGE_SIZE) {
574 					m = vm_page_lookup(mem->am_obj,
575 							   OFF_TO_IDX(k));
576 					vm_page_unwire(m, 0);
577 				}
578 				lwkt_reltoken(&vm_token);
579 				lockmgr(&sc->as_lock, LK_RELEASE);
580 				return error;
581 			}
582 		}
583 		vm_page_wakeup(m);
584 	}
585 
586 	/*
587 	 * Flush the cpu cache since we are providing a new mapping
588 	 * for these pages.
589 	 */
590 	agp_flush_cache();
591 
592 	/*
593 	 * Make sure the chipset gets the new mappings.
594 	 */
595 	AGP_FLUSH_TLB(dev);
596 
597 	mem->am_offset = offset;
598 	mem->am_is_bound = 1;
599 
600 	lockmgr(&sc->as_lock, LK_RELEASE);
601 
602 	return 0;
603 }
604 
605 int
606 agp_generic_unbind_memory(device_t dev, struct agp_memory *mem)
607 {
608 	struct agp_softc *sc = device_get_softc(dev);
609 	vm_page_t m;
610 	int i;
611 
612 	lockmgr(&sc->as_lock, LK_EXCLUSIVE);
613 
614 	if (!mem->am_is_bound) {
615 		device_printf(dev, "memory is not bound\n");
616 		lockmgr(&sc->as_lock, LK_RELEASE);
617 		return EINVAL;
618 	}
619 
620 
621 	/*
622 	 * Unbind the individual pages and flush the chipset's
623 	 * TLB. Unwire the pages so they can be swapped.
624 	 */
625 	for (i = 0; i < mem->am_size; i += AGP_PAGE_SIZE)
626 		AGP_UNBIND_PAGE(dev, mem->am_offset + i);
627 	lwkt_gettoken(&vm_token);
628 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
629 		m = vm_page_lookup(mem->am_obj, atop(i));
630 		vm_page_unwire(m, 0);
631 	}
632 	lwkt_reltoken(&vm_token);
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)) != 0) {
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