xref: /freebsd/sys/dev/agp/agp.c (revision a9148abd9da5db2f1c682fb17bed791845fc41c9)
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/module.h>
37 #include <sys/bus.h>
38 #include <sys/conf.h>
39 #include <sys/ioccom.h>
40 #include <sys/agpio.h>
41 #include <sys/lock.h>
42 #include <sys/mutex.h>
43 #include <sys/proc.h>
44 
45 #include <dev/agp/agppriv.h>
46 #include <dev/agp/agpvar.h>
47 #include <dev/agp/agpreg.h>
48 #include <dev/pci/pcivar.h>
49 #include <dev/pci/pcireg.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 				/* agp_drv.c */
67 static d_open_t agp_open;
68 static d_close_t agp_close;
69 static d_ioctl_t agp_ioctl;
70 static d_mmap_t agp_mmap;
71 
72 static struct cdevsw agp_cdevsw = {
73 	.d_version =	D_VERSION,
74 	.d_flags =	D_NEEDGIANT,
75 	.d_open =	agp_open,
76 	.d_close =	agp_close,
77 	.d_ioctl =	agp_ioctl,
78 	.d_mmap =	agp_mmap,
79 	.d_name =	"agp",
80 };
81 
82 static devclass_t agp_devclass;
83 #define KDEV2DEV(kdev)	devclass_get_device(agp_devclass, dev2unit(kdev))
84 
85 /* Helper functions for implementing chipset mini drivers. */
86 
87 void
88 agp_flush_cache()
89 {
90 #if defined(__i386__) || defined(__amd64__)
91 	wbinvd();
92 #endif
93 }
94 
95 u_int8_t
96 agp_find_caps(device_t dev)
97 {
98 	int capreg;
99 
100 
101 	if (pci_find_extcap(dev, PCIY_AGP, &capreg) != 0)
102 		capreg = 0;
103 	return (capreg);
104 }
105 
106 /*
107  * Find an AGP display device (if any).
108  */
109 static device_t
110 agp_find_display(void)
111 {
112 	devclass_t pci = devclass_find("pci");
113 	device_t bus, dev = 0;
114 	device_t *kids;
115 	int busnum, numkids, i;
116 
117 	for (busnum = 0; busnum < devclass_get_maxunit(pci); busnum++) {
118 		bus = devclass_get_device(pci, busnum);
119 		if (!bus)
120 			continue;
121 		if (device_get_children(bus, &kids, &numkids) != 0)
122 			continue;
123 		for (i = 0; i < numkids; i++) {
124 			dev = kids[i];
125 			if (pci_get_class(dev) == PCIC_DISPLAY
126 			    && pci_get_subclass(dev) == PCIS_DISPLAY_VGA)
127 				if (agp_find_caps(dev)) {
128 					free(kids, M_TEMP);
129 					return dev;
130 				}
131 
132 		}
133 		free(kids, M_TEMP);
134 	}
135 
136 	return 0;
137 }
138 
139 struct agp_gatt *
140 agp_alloc_gatt(device_t dev)
141 {
142 	u_int32_t apsize = AGP_GET_APERTURE(dev);
143 	u_int32_t entries = apsize >> AGP_PAGE_SHIFT;
144 	struct agp_gatt *gatt;
145 
146 	if (bootverbose)
147 		device_printf(dev,
148 			      "allocating GATT for aperture of size %dM\n",
149 			      apsize / (1024*1024));
150 
151 	if (entries == 0) {
152 		device_printf(dev, "bad aperture size\n");
153 		return NULL;
154 	}
155 
156 	gatt = malloc(sizeof(struct agp_gatt), M_AGP, M_NOWAIT);
157 	if (!gatt)
158 		return 0;
159 
160 	gatt->ag_entries = entries;
161 	gatt->ag_virtual = contigmalloc(entries * sizeof(u_int32_t), M_AGP, 0,
162 					0, ~0, PAGE_SIZE, 0);
163 	if (!gatt->ag_virtual) {
164 		if (bootverbose)
165 			device_printf(dev, "contiguous allocation failed\n");
166 		free(gatt, M_AGP);
167 		return 0;
168 	}
169 	bzero(gatt->ag_virtual, entries * sizeof(u_int32_t));
170 	gatt->ag_physical = vtophys((vm_offset_t) gatt->ag_virtual);
171 	agp_flush_cache();
172 
173 	return gatt;
174 }
175 
176 void
177 agp_free_gatt(struct agp_gatt *gatt)
178 {
179 	contigfree(gatt->ag_virtual,
180 		   gatt->ag_entries * sizeof(u_int32_t), M_AGP);
181 	free(gatt, M_AGP);
182 }
183 
184 static u_int agp_max[][2] = {
185 	{0,	0},
186 	{32,	4},
187 	{64,	28},
188 	{128,	96},
189 	{256,	204},
190 	{512,	440},
191 	{1024,	942},
192 	{2048,	1920},
193 	{4096,	3932}
194 };
195 #define agp_max_size	(sizeof(agp_max) / sizeof(agp_max[0]))
196 
197 /**
198  * Sets the PCI resource which represents the AGP aperture.
199  *
200  * If not called, the default AGP aperture resource of AGP_APBASE will
201  * be used.  Must be called before agp_generic_attach().
202  */
203 void
204 agp_set_aperture_resource(device_t dev, int rid)
205 {
206 	struct agp_softc *sc = device_get_softc(dev);
207 
208 	sc->as_aperture_rid = rid;
209 }
210 
211 int
212 agp_generic_attach(device_t dev)
213 {
214 	struct agp_softc *sc = device_get_softc(dev);
215 	int i;
216 	u_int memsize;
217 
218 	/*
219 	 * Find and map the aperture, RF_SHAREABLE for DRM but not RF_ACTIVE
220 	 * because the kernel doesn't need to map it.
221 	 */
222 	if (sc->as_aperture_rid == 0)
223 		sc->as_aperture_rid = AGP_APBASE;
224 
225 	sc->as_aperture = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
226 	    &sc->as_aperture_rid, RF_SHAREABLE);
227 	if (!sc->as_aperture)
228 		return ENOMEM;
229 
230 	/*
231 	 * Work out an upper bound for agp memory allocation. This
232 	 * uses a heurisitc table from the Linux driver.
233 	 */
234 	memsize = ptoa(Maxmem) >> 20;
235 	for (i = 0; i < agp_max_size; i++) {
236 		if (memsize <= agp_max[i][0])
237 			break;
238 	}
239 	if (i == agp_max_size) i = agp_max_size - 1;
240 	sc->as_maxmem = agp_max[i][1] << 20U;
241 
242 	/*
243 	 * The lock is used to prevent re-entry to
244 	 * agp_generic_bind_memory() since that function can sleep.
245 	 */
246 	mtx_init(&sc->as_lock, "agp lock", NULL, MTX_DEF);
247 
248 	/*
249 	 * Initialise stuff for the userland device.
250 	 */
251 	agp_devclass = devclass_find("agp");
252 	TAILQ_INIT(&sc->as_memory);
253 	sc->as_nextid = 1;
254 
255 	sc->as_devnode = make_dev(&agp_cdevsw,
256 				  device_get_unit(dev),
257 				  UID_ROOT,
258 				  GID_WHEEL,
259 				  0600,
260 				  "agpgart");
261 
262 	return 0;
263 }
264 
265 void
266 agp_free_cdev(device_t dev)
267 {
268 	struct agp_softc *sc = device_get_softc(dev);
269 
270 	destroy_dev(sc->as_devnode);
271 }
272 
273 void
274 agp_free_res(device_t dev)
275 {
276 	struct agp_softc *sc = device_get_softc(dev);
277 
278 	bus_release_resource(dev, SYS_RES_MEMORY, sc->as_aperture_rid,
279 	    sc->as_aperture);
280 	mtx_destroy(&sc->as_lock);
281 	agp_flush_cache();
282 }
283 
284 int
285 agp_generic_detach(device_t dev)
286 {
287 
288 	agp_free_cdev(dev);
289 	agp_free_res(dev);
290 	return 0;
291 }
292 
293 /**
294  * Default AGP aperture size detection which simply returns the size of
295  * the aperture's PCI resource.
296  */
297 int
298 agp_generic_get_aperture(device_t dev)
299 {
300 	struct agp_softc *sc = device_get_softc(dev);
301 
302 	return rman_get_size(sc->as_aperture);
303 }
304 
305 /**
306  * Default AGP aperture size setting function, which simply doesn't allow
307  * changes to resource size.
308  */
309 int
310 agp_generic_set_aperture(device_t dev, u_int32_t aperture)
311 {
312 	u_int32_t current_aperture;
313 
314 	current_aperture = AGP_GET_APERTURE(dev);
315 	if (current_aperture != aperture)
316 		return EINVAL;
317 	else
318 		return 0;
319 }
320 
321 /*
322  * This does the enable logic for v3, with the same topology
323  * restrictions as in place for v2 -- one bus, one device on the bus.
324  */
325 static int
326 agp_v3_enable(device_t dev, device_t mdev, u_int32_t mode)
327 {
328 	u_int32_t tstatus, mstatus;
329 	u_int32_t command;
330 	int rq, sba, fw, rate, arqsz, cal;
331 
332 	tstatus = pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
333 	mstatus = pci_read_config(mdev, agp_find_caps(mdev) + AGP_STATUS, 4);
334 
335 	/* Set RQ to the min of mode, tstatus and mstatus */
336 	rq = AGP_MODE_GET_RQ(mode);
337 	if (AGP_MODE_GET_RQ(tstatus) < rq)
338 		rq = AGP_MODE_GET_RQ(tstatus);
339 	if (AGP_MODE_GET_RQ(mstatus) < rq)
340 		rq = AGP_MODE_GET_RQ(mstatus);
341 
342 	/*
343 	 * ARQSZ - Set the value to the maximum one.
344 	 * Don't allow the mode register to override values.
345 	 */
346 	arqsz = AGP_MODE_GET_ARQSZ(mode);
347 	if (AGP_MODE_GET_ARQSZ(tstatus) > rq)
348 		rq = AGP_MODE_GET_ARQSZ(tstatus);
349 	if (AGP_MODE_GET_ARQSZ(mstatus) > rq)
350 		rq = AGP_MODE_GET_ARQSZ(mstatus);
351 
352 	/* Calibration cycle - don't allow override by mode register */
353 	cal = AGP_MODE_GET_CAL(tstatus);
354 	if (AGP_MODE_GET_CAL(mstatus) < cal)
355 		cal = AGP_MODE_GET_CAL(mstatus);
356 
357 	/* SBA must be supported for AGP v3. */
358 	sba = 1;
359 
360 	/* Set FW if all three support it. */
361 	fw = (AGP_MODE_GET_FW(tstatus)
362 	       & AGP_MODE_GET_FW(mstatus)
363 	       & AGP_MODE_GET_FW(mode));
364 
365 	/* Figure out the max rate */
366 	rate = (AGP_MODE_GET_RATE(tstatus)
367 		& AGP_MODE_GET_RATE(mstatus)
368 		& AGP_MODE_GET_RATE(mode));
369 	if (rate & AGP_MODE_V3_RATE_8x)
370 		rate = AGP_MODE_V3_RATE_8x;
371 	else
372 		rate = AGP_MODE_V3_RATE_4x;
373 	if (bootverbose)
374 		device_printf(dev, "Setting AGP v3 mode %d\n", rate * 4);
375 
376 	pci_write_config(dev, agp_find_caps(dev) + AGP_COMMAND, 0, 4);
377 
378 	/* Construct the new mode word and tell the hardware */
379 	command = 0;
380 	command = AGP_MODE_SET_RQ(0, rq);
381 	command = AGP_MODE_SET_ARQSZ(command, arqsz);
382 	command = AGP_MODE_SET_CAL(command, cal);
383 	command = AGP_MODE_SET_SBA(command, sba);
384 	command = AGP_MODE_SET_FW(command, fw);
385 	command = AGP_MODE_SET_RATE(command, rate);
386 	command = AGP_MODE_SET_MODE_3(command, 1);
387 	command = AGP_MODE_SET_AGP(command, 1);
388 	pci_write_config(dev, agp_find_caps(dev) + AGP_COMMAND, command, 4);
389 	pci_write_config(mdev, agp_find_caps(mdev) + AGP_COMMAND, command, 4);
390 
391 	return 0;
392 }
393 
394 static int
395 agp_v2_enable(device_t dev, device_t mdev, u_int32_t mode)
396 {
397 	u_int32_t tstatus, mstatus;
398 	u_int32_t command;
399 	int rq, sba, fw, rate;
400 
401 	tstatus = pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
402 	mstatus = pci_read_config(mdev, agp_find_caps(mdev) + AGP_STATUS, 4);
403 
404 	/* Set RQ to the min of mode, tstatus and mstatus */
405 	rq = AGP_MODE_GET_RQ(mode);
406 	if (AGP_MODE_GET_RQ(tstatus) < rq)
407 		rq = AGP_MODE_GET_RQ(tstatus);
408 	if (AGP_MODE_GET_RQ(mstatus) < rq)
409 		rq = AGP_MODE_GET_RQ(mstatus);
410 
411 	/* Set SBA if all three can deal with SBA */
412 	sba = (AGP_MODE_GET_SBA(tstatus)
413 	       & AGP_MODE_GET_SBA(mstatus)
414 	       & AGP_MODE_GET_SBA(mode));
415 
416 	/* Similar for FW */
417 	fw = (AGP_MODE_GET_FW(tstatus)
418 	       & AGP_MODE_GET_FW(mstatus)
419 	       & AGP_MODE_GET_FW(mode));
420 
421 	/* Figure out the max rate */
422 	rate = (AGP_MODE_GET_RATE(tstatus)
423 		& AGP_MODE_GET_RATE(mstatus)
424 		& AGP_MODE_GET_RATE(mode));
425 	if (rate & AGP_MODE_V2_RATE_4x)
426 		rate = AGP_MODE_V2_RATE_4x;
427 	else if (rate & AGP_MODE_V2_RATE_2x)
428 		rate = AGP_MODE_V2_RATE_2x;
429 	else
430 		rate = AGP_MODE_V2_RATE_1x;
431 	if (bootverbose)
432 		device_printf(dev, "Setting AGP v2 mode %d\n", rate);
433 
434 	/* Construct the new mode word and tell the hardware */
435 	command = 0;
436 	command = AGP_MODE_SET_RQ(0, rq);
437 	command = AGP_MODE_SET_SBA(command, sba);
438 	command = AGP_MODE_SET_FW(command, fw);
439 	command = AGP_MODE_SET_RATE(command, rate);
440 	command = AGP_MODE_SET_AGP(command, 1);
441 	pci_write_config(dev, agp_find_caps(dev) + AGP_COMMAND, command, 4);
442 	pci_write_config(mdev, agp_find_caps(mdev) + AGP_COMMAND, command, 4);
443 
444 	return 0;
445 }
446 
447 int
448 agp_generic_enable(device_t dev, u_int32_t mode)
449 {
450 	device_t mdev = agp_find_display();
451 	u_int32_t tstatus, mstatus;
452 
453 	if (!mdev) {
454 		AGP_DPF("can't find display\n");
455 		return ENXIO;
456 	}
457 
458 	tstatus = pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
459 	mstatus = pci_read_config(mdev, agp_find_caps(mdev) + AGP_STATUS, 4);
460 
461 	/*
462 	 * Check display and bridge for AGP v3 support.  AGP v3 allows
463 	 * more variety in topology than v2, e.g. multiple AGP devices
464 	 * attached to one bridge, or multiple AGP bridges in one
465 	 * system.  This doesn't attempt to address those situations,
466 	 * but should work fine for a classic single AGP slot system
467 	 * with AGP v3.
468 	 */
469 	if (AGP_MODE_GET_MODE_3(mode) &&
470 	    AGP_MODE_GET_MODE_3(tstatus) &&
471 	    AGP_MODE_GET_MODE_3(mstatus))
472 		return (agp_v3_enable(dev, mdev, mode));
473 	else
474 		return (agp_v2_enable(dev, mdev, mode));
475 }
476 
477 struct agp_memory *
478 agp_generic_alloc_memory(device_t dev, int type, vm_size_t size)
479 {
480 	struct agp_softc *sc = device_get_softc(dev);
481 	struct agp_memory *mem;
482 
483 	if ((size & (AGP_PAGE_SIZE - 1)) != 0)
484 		return 0;
485 
486 	if (sc->as_allocated + size > sc->as_maxmem)
487 		return 0;
488 
489 	if (type != 0) {
490 		printf("agp_generic_alloc_memory: unsupported type %d\n",
491 		       type);
492 		return 0;
493 	}
494 
495 	mem = malloc(sizeof *mem, M_AGP, M_WAITOK);
496 	mem->am_id = sc->as_nextid++;
497 	mem->am_size = size;
498 	mem->am_type = 0;
499 	mem->am_obj = vm_object_allocate(OBJT_DEFAULT, atop(round_page(size)));
500 	mem->am_physical = 0;
501 	mem->am_offset = 0;
502 	mem->am_is_bound = 0;
503 	TAILQ_INSERT_TAIL(&sc->as_memory, mem, am_link);
504 	sc->as_allocated += size;
505 
506 	return mem;
507 }
508 
509 int
510 agp_generic_free_memory(device_t dev, struct agp_memory *mem)
511 {
512 	struct agp_softc *sc = device_get_softc(dev);
513 
514 	if (mem->am_is_bound)
515 		return EBUSY;
516 
517 	sc->as_allocated -= mem->am_size;
518 	TAILQ_REMOVE(&sc->as_memory, mem, am_link);
519 	vm_object_deallocate(mem->am_obj);
520 	free(mem, M_AGP);
521 	return 0;
522 }
523 
524 int
525 agp_generic_bind_memory(device_t dev, struct agp_memory *mem,
526 			vm_offset_t offset)
527 {
528 	struct agp_softc *sc = device_get_softc(dev);
529 	vm_offset_t i, j, k;
530 	vm_page_t m;
531 	int error;
532 
533 	/* Do some sanity checks first. */
534 	if (offset < 0 || (offset & (AGP_PAGE_SIZE - 1)) != 0 ||
535 	    offset + mem->am_size > AGP_GET_APERTURE(dev)) {
536 		device_printf(dev, "binding memory at bad offset %#x\n",
537 		    (int)offset);
538 		return EINVAL;
539 	}
540 
541 	/*
542 	 * Allocate the pages early, before acquiring the lock,
543 	 * because vm_page_grab() used with VM_ALLOC_RETRY may
544 	 * block and we can't hold a mutex while blocking.
545 	 */
546 	VM_OBJECT_LOCK(mem->am_obj);
547 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
548 		/*
549 		 * Find a page from the object and wire it
550 		 * down. This page will be mapped using one or more
551 		 * entries in the GATT (assuming that PAGE_SIZE >=
552 		 * AGP_PAGE_SIZE. If this is the first call to bind,
553 		 * the pages will be allocated and zeroed.
554 		 */
555 		m = vm_page_grab(mem->am_obj, OFF_TO_IDX(i),
556 		    VM_ALLOC_WIRED | VM_ALLOC_ZERO | VM_ALLOC_RETRY);
557 		AGP_DPF("found page pa=%#x\n", VM_PAGE_TO_PHYS(m));
558 	}
559 	VM_OBJECT_UNLOCK(mem->am_obj);
560 
561 	mtx_lock(&sc->as_lock);
562 
563 	if (mem->am_is_bound) {
564 		device_printf(dev, "memory already bound\n");
565 		error = EINVAL;
566 		VM_OBJECT_LOCK(mem->am_obj);
567 		goto bad;
568 	}
569 
570 	/*
571 	 * Bind the individual pages and flush the chipset's
572 	 * TLB.
573 	 */
574 	VM_OBJECT_LOCK(mem->am_obj);
575 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
576 		m = vm_page_lookup(mem->am_obj, OFF_TO_IDX(i));
577 
578 		/*
579 		 * Install entries in the GATT, making sure that if
580 		 * AGP_PAGE_SIZE < PAGE_SIZE and mem->am_size is not
581 		 * aligned to PAGE_SIZE, we don't modify too many GATT
582 		 * entries.
583 		 */
584 		for (j = 0; j < PAGE_SIZE && i + j < mem->am_size;
585 		     j += AGP_PAGE_SIZE) {
586 			vm_offset_t pa = VM_PAGE_TO_PHYS(m) + j;
587 			AGP_DPF("binding offset %#x to pa %#x\n",
588 				offset + i + j, pa);
589 			error = AGP_BIND_PAGE(dev, offset + i + j, pa);
590 			if (error) {
591 				/*
592 				 * Bail out. Reverse all the mappings
593 				 * and unwire the pages.
594 				 */
595 				vm_page_wakeup(m);
596 				for (k = 0; k < i + j; k += AGP_PAGE_SIZE)
597 					AGP_UNBIND_PAGE(dev, offset + k);
598 				goto bad;
599 			}
600 		}
601 		vm_page_wakeup(m);
602 	}
603 	VM_OBJECT_UNLOCK(mem->am_obj);
604 
605 	/*
606 	 * Flush the cpu cache since we are providing a new mapping
607 	 * for these pages.
608 	 */
609 	agp_flush_cache();
610 
611 	/*
612 	 * Make sure the chipset gets the new mappings.
613 	 */
614 	AGP_FLUSH_TLB(dev);
615 
616 	mem->am_offset = offset;
617 	mem->am_is_bound = 1;
618 
619 	mtx_unlock(&sc->as_lock);
620 
621 	return 0;
622 bad:
623 	mtx_unlock(&sc->as_lock);
624 	VM_OBJECT_LOCK_ASSERT(mem->am_obj, MA_OWNED);
625 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
626 		m = vm_page_lookup(mem->am_obj, OFF_TO_IDX(i));
627 		vm_page_lock_queues();
628 		vm_page_unwire(m, 0);
629 		vm_page_unlock_queues();
630 	}
631 	VM_OBJECT_UNLOCK(mem->am_obj);
632 
633 	return error;
634 }
635 
636 int
637 agp_generic_unbind_memory(device_t dev, struct agp_memory *mem)
638 {
639 	struct agp_softc *sc = device_get_softc(dev);
640 	vm_page_t m;
641 	int i;
642 
643 	mtx_lock(&sc->as_lock);
644 
645 	if (!mem->am_is_bound) {
646 		device_printf(dev, "memory is not bound\n");
647 		mtx_unlock(&sc->as_lock);
648 		return EINVAL;
649 	}
650 
651 
652 	/*
653 	 * Unbind the individual pages and flush the chipset's
654 	 * TLB. Unwire the pages so they can be swapped.
655 	 */
656 	for (i = 0; i < mem->am_size; i += AGP_PAGE_SIZE)
657 		AGP_UNBIND_PAGE(dev, mem->am_offset + i);
658 	VM_OBJECT_LOCK(mem->am_obj);
659 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
660 		m = vm_page_lookup(mem->am_obj, atop(i));
661 		vm_page_lock_queues();
662 		vm_page_unwire(m, 0);
663 		vm_page_unlock_queues();
664 	}
665 	VM_OBJECT_UNLOCK(mem->am_obj);
666 
667 	agp_flush_cache();
668 	AGP_FLUSH_TLB(dev);
669 
670 	mem->am_offset = 0;
671 	mem->am_is_bound = 0;
672 
673 	mtx_unlock(&sc->as_lock);
674 
675 	return 0;
676 }
677 
678 /* Helper functions for implementing user/kernel api */
679 
680 static int
681 agp_acquire_helper(device_t dev, enum agp_acquire_state state)
682 {
683 	struct agp_softc *sc = device_get_softc(dev);
684 
685 	if (sc->as_state != AGP_ACQUIRE_FREE)
686 		return EBUSY;
687 	sc->as_state = state;
688 
689 	return 0;
690 }
691 
692 static int
693 agp_release_helper(device_t dev, enum agp_acquire_state state)
694 {
695 	struct agp_softc *sc = device_get_softc(dev);
696 
697 	if (sc->as_state == AGP_ACQUIRE_FREE)
698 		return 0;
699 
700 	if (sc->as_state != state)
701 		return EBUSY;
702 
703 	sc->as_state = AGP_ACQUIRE_FREE;
704 	return 0;
705 }
706 
707 static struct agp_memory *
708 agp_find_memory(device_t dev, int id)
709 {
710 	struct agp_softc *sc = device_get_softc(dev);
711 	struct agp_memory *mem;
712 
713 	AGP_DPF("searching for memory block %d\n", id);
714 	TAILQ_FOREACH(mem, &sc->as_memory, am_link) {
715 		AGP_DPF("considering memory block %d\n", mem->am_id);
716 		if (mem->am_id == id)
717 			return mem;
718 	}
719 	return 0;
720 }
721 
722 /* Implementation of the userland ioctl api */
723 
724 static int
725 agp_info_user(device_t dev, agp_info *info)
726 {
727 	struct agp_softc *sc = device_get_softc(dev);
728 
729 	bzero(info, sizeof *info);
730 	info->bridge_id = pci_get_devid(dev);
731 	info->agp_mode =
732 	    pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
733 	info->aper_base = rman_get_start(sc->as_aperture);
734 	info->aper_size = AGP_GET_APERTURE(dev) >> 20;
735 	info->pg_total = info->pg_system = sc->as_maxmem >> AGP_PAGE_SHIFT;
736 	info->pg_used = sc->as_allocated >> AGP_PAGE_SHIFT;
737 
738 	return 0;
739 }
740 
741 static int
742 agp_setup_user(device_t dev, agp_setup *setup)
743 {
744 	return AGP_ENABLE(dev, setup->agp_mode);
745 }
746 
747 static int
748 agp_allocate_user(device_t dev, agp_allocate *alloc)
749 {
750 	struct agp_memory *mem;
751 
752 	mem = AGP_ALLOC_MEMORY(dev,
753 			       alloc->type,
754 			       alloc->pg_count << AGP_PAGE_SHIFT);
755 	if (mem) {
756 		alloc->key = mem->am_id;
757 		alloc->physical = mem->am_physical;
758 		return 0;
759 	} else {
760 		return ENOMEM;
761 	}
762 }
763 
764 static int
765 agp_deallocate_user(device_t dev, int id)
766 {
767 	struct agp_memory *mem = agp_find_memory(dev, id);;
768 
769 	if (mem) {
770 		AGP_FREE_MEMORY(dev, mem);
771 		return 0;
772 	} else {
773 		return ENOENT;
774 	}
775 }
776 
777 static int
778 agp_bind_user(device_t dev, agp_bind *bind)
779 {
780 	struct agp_memory *mem = agp_find_memory(dev, bind->key);
781 
782 	if (!mem)
783 		return ENOENT;
784 
785 	return AGP_BIND_MEMORY(dev, mem, bind->pg_start << AGP_PAGE_SHIFT);
786 }
787 
788 static int
789 agp_unbind_user(device_t dev, agp_unbind *unbind)
790 {
791 	struct agp_memory *mem = agp_find_memory(dev, unbind->key);
792 
793 	if (!mem)
794 		return ENOENT;
795 
796 	return AGP_UNBIND_MEMORY(dev, mem);
797 }
798 
799 static int
800 agp_open(struct cdev *kdev, int oflags, int devtype, struct thread *td)
801 {
802 	device_t dev = KDEV2DEV(kdev);
803 	struct agp_softc *sc = device_get_softc(dev);
804 
805 	if (!sc->as_isopen) {
806 		sc->as_isopen = 1;
807 		device_busy(dev);
808 	}
809 
810 	return 0;
811 }
812 
813 static int
814 agp_close(struct cdev *kdev, int fflag, int devtype, struct thread *td)
815 {
816 	device_t dev = KDEV2DEV(kdev);
817 	struct agp_softc *sc = device_get_softc(dev);
818 	struct agp_memory *mem;
819 
820 	/*
821 	 * Clear the GATT and force release on last close
822 	 */
823 	while ((mem = TAILQ_FIRST(&sc->as_memory)) != 0) {
824 		if (mem->am_is_bound)
825 			AGP_UNBIND_MEMORY(dev, mem);
826 		AGP_FREE_MEMORY(dev, mem);
827 	}
828 	if (sc->as_state == AGP_ACQUIRE_USER)
829 		agp_release_helper(dev, AGP_ACQUIRE_USER);
830 	sc->as_isopen = 0;
831 	device_unbusy(dev);
832 
833 	return 0;
834 }
835 
836 static int
837 agp_ioctl(struct cdev *kdev, u_long cmd, caddr_t data, int fflag, struct thread *td)
838 {
839 	device_t dev = KDEV2DEV(kdev);
840 
841 	switch (cmd) {
842 	case AGPIOC_INFO:
843 		return agp_info_user(dev, (agp_info *) data);
844 
845 	case AGPIOC_ACQUIRE:
846 		return agp_acquire_helper(dev, AGP_ACQUIRE_USER);
847 
848 	case AGPIOC_RELEASE:
849 		return agp_release_helper(dev, AGP_ACQUIRE_USER);
850 
851 	case AGPIOC_SETUP:
852 		return agp_setup_user(dev, (agp_setup *)data);
853 
854 	case AGPIOC_ALLOCATE:
855 		return agp_allocate_user(dev, (agp_allocate *)data);
856 
857 	case AGPIOC_DEALLOCATE:
858 		return agp_deallocate_user(dev, *(int *) data);
859 
860 	case AGPIOC_BIND:
861 		return agp_bind_user(dev, (agp_bind *)data);
862 
863 	case AGPIOC_UNBIND:
864 		return agp_unbind_user(dev, (agp_unbind *)data);
865 
866 	}
867 
868 	return EINVAL;
869 }
870 
871 static int
872 agp_mmap(struct cdev *kdev, vm_offset_t offset, vm_paddr_t *paddr, int prot)
873 {
874 	device_t dev = KDEV2DEV(kdev);
875 	struct agp_softc *sc = device_get_softc(dev);
876 
877 	if (offset > AGP_GET_APERTURE(dev))
878 		return -1;
879 	*paddr = rman_get_start(sc->as_aperture) + offset;
880 	return 0;
881 }
882 
883 /* Implementation of the kernel api */
884 
885 device_t
886 agp_find_device()
887 {
888 	device_t *children, child;
889 	int i, count;
890 
891 	if (!agp_devclass)
892 		return NULL;
893 	if (devclass_get_devices(agp_devclass, &children, &count) != 0)
894 		return NULL;
895 	child = NULL;
896 	for (i = 0; i < count; i++) {
897 		if (device_is_attached(children[i])) {
898 			child = children[i];
899 			break;
900 		}
901 	}
902 	free(children, M_TEMP);
903 	return child;
904 }
905 
906 enum agp_acquire_state
907 agp_state(device_t dev)
908 {
909 	struct agp_softc *sc = device_get_softc(dev);
910 	return sc->as_state;
911 }
912 
913 void
914 agp_get_info(device_t dev, struct agp_info *info)
915 {
916 	struct agp_softc *sc = device_get_softc(dev);
917 
918 	info->ai_mode =
919 		pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
920 	info->ai_aperture_base = rman_get_start(sc->as_aperture);
921 	info->ai_aperture_size = rman_get_size(sc->as_aperture);
922 	info->ai_memory_allowed = sc->as_maxmem;
923 	info->ai_memory_used = sc->as_allocated;
924 }
925 
926 int
927 agp_acquire(device_t dev)
928 {
929 	return agp_acquire_helper(dev, AGP_ACQUIRE_KERNEL);
930 }
931 
932 int
933 agp_release(device_t dev)
934 {
935 	return agp_release_helper(dev, AGP_ACQUIRE_KERNEL);
936 }
937 
938 int
939 agp_enable(device_t dev, u_int32_t mode)
940 {
941 	return AGP_ENABLE(dev, mode);
942 }
943 
944 void *agp_alloc_memory(device_t dev, int type, vm_size_t bytes)
945 {
946 	return  (void *) AGP_ALLOC_MEMORY(dev, type, bytes);
947 }
948 
949 void agp_free_memory(device_t dev, void *handle)
950 {
951 	struct agp_memory *mem = (struct agp_memory *) handle;
952 	AGP_FREE_MEMORY(dev, mem);
953 }
954 
955 int agp_bind_memory(device_t dev, void *handle, vm_offset_t offset)
956 {
957 	struct agp_memory *mem = (struct agp_memory *) handle;
958 	return AGP_BIND_MEMORY(dev, mem, offset);
959 }
960 
961 int agp_unbind_memory(device_t dev, void *handle)
962 {
963 	struct agp_memory *mem = (struct agp_memory *) handle;
964 	return AGP_UNBIND_MEMORY(dev, mem);
965 }
966 
967 void agp_memory_info(device_t dev, void *handle, struct
968 		     agp_memory_info *mi)
969 {
970 	struct agp_memory *mem = (struct agp_memory *) handle;
971 
972 	mi->ami_size = mem->am_size;
973 	mi->ami_physical = mem->am_physical;
974 	mi->ami_offset = mem->am_offset;
975 	mi->ami_is_bound = mem->am_is_bound;
976 }
977