xref: /freebsd/sys/dev/agp/agp.c (revision 87569f75a91f298c52a71823c04d41cf53c88889)
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/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 				/* 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, minor(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 #ifdef __alpha__
94 	/* FIXME: This is most likely not correct as it doesn't flush CPU
95 	 * write caches, but we don't have a facility to do that and
96 	 * this is all linux does, too */
97 	alpha_mb();
98 #endif
99 }
100 
101 u_int8_t
102 agp_find_caps(device_t dev)
103 {
104 	int capreg;
105 
106 
107 	if (pci_find_extcap(dev, PCIY_AGP, &capreg) != 0)
108 		capreg = 0;
109 	return (capreg);
110 }
111 
112 /*
113  * Find an AGP display device (if any).
114  */
115 static device_t
116 agp_find_display(void)
117 {
118 	devclass_t pci = devclass_find("pci");
119 	device_t bus, dev = 0;
120 	device_t *kids;
121 	int busnum, numkids, i;
122 
123 	for (busnum = 0; busnum < devclass_get_maxunit(pci); busnum++) {
124 		bus = devclass_get_device(pci, busnum);
125 		if (!bus)
126 			continue;
127 		device_get_children(bus, &kids, &numkids);
128 		for (i = 0; i < numkids; i++) {
129 			dev = kids[i];
130 			if (pci_get_class(dev) == PCIC_DISPLAY
131 			    && pci_get_subclass(dev) == PCIS_DISPLAY_VGA)
132 				if (agp_find_caps(dev)) {
133 					free(kids, M_TEMP);
134 					return dev;
135 				}
136 
137 		}
138 		free(kids, M_TEMP);
139 	}
140 
141 	return 0;
142 }
143 
144 struct agp_gatt *
145 agp_alloc_gatt(device_t dev)
146 {
147 	u_int32_t apsize = AGP_GET_APERTURE(dev);
148 	u_int32_t entries = apsize >> AGP_PAGE_SHIFT;
149 	struct agp_gatt *gatt;
150 
151 	if (bootverbose)
152 		device_printf(dev,
153 			      "allocating GATT for aperture of size %dM\n",
154 			      apsize / (1024*1024));
155 
156 	if (entries == 0) {
157 		device_printf(dev, "bad aperture size\n");
158 		return NULL;
159 	}
160 
161 	gatt = malloc(sizeof(struct agp_gatt), M_AGP, M_NOWAIT);
162 	if (!gatt)
163 		return 0;
164 
165 	gatt->ag_entries = entries;
166 	gatt->ag_virtual = contigmalloc(entries * sizeof(u_int32_t), M_AGP, 0,
167 					0, ~0, PAGE_SIZE, 0);
168 	if (!gatt->ag_virtual) {
169 		if (bootverbose)
170 			device_printf(dev, "contiguous allocation failed\n");
171 		free(gatt, M_AGP);
172 		return 0;
173 	}
174 	bzero(gatt->ag_virtual, entries * sizeof(u_int32_t));
175 	gatt->ag_physical = vtophys((vm_offset_t) gatt->ag_virtual);
176 	agp_flush_cache();
177 
178 	return gatt;
179 }
180 
181 void
182 agp_free_gatt(struct agp_gatt *gatt)
183 {
184 	contigfree(gatt->ag_virtual,
185 		   gatt->ag_entries * sizeof(u_int32_t), M_AGP);
186 	free(gatt, M_AGP);
187 }
188 
189 static int agp_max[][2] = {
190 	{0,	0},
191 	{32,	4},
192 	{64,	28},
193 	{128,	96},
194 	{256,	204},
195 	{512,	440},
196 	{1024,	942},
197 	{2048,	1920},
198 	{4096,	3932}
199 };
200 #define agp_max_size	(sizeof(agp_max) / sizeof(agp_max[0]))
201 
202 int
203 agp_generic_attach(device_t dev)
204 {
205 	struct agp_softc *sc = device_get_softc(dev);
206 	int rid, memsize, i;
207 
208 	/*
209 	 * Find and map the aperture.
210 	 */
211 	rid = AGP_APBASE;
212 	sc->as_aperture = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, 0);
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 	mtx_init(&sc->as_lock, "agp lock", NULL, MTX_DEF);
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 	sc->as_devnode = make_dev(&agp_cdevsw,
242 				  device_get_unit(dev),
243 				  UID_ROOT,
244 				  GID_WHEEL,
245 				  0600,
246 				  "agpgart");
247 
248 	return 0;
249 }
250 
251 int
252 agp_generic_detach(device_t dev)
253 {
254 	struct agp_softc *sc = device_get_softc(dev);
255 
256 	destroy_dev(sc->as_devnode);
257 	bus_release_resource(dev, SYS_RES_MEMORY, AGP_APBASE, sc->as_aperture);
258 	mtx_destroy(&sc->as_lock);
259 	agp_flush_cache();
260 	return 0;
261 }
262 
263 /*
264  * This does the enable logic for v3, with the same topology
265  * restrictions as in place for v2 -- one bus, one device on the bus.
266  */
267 static int
268 agp_v3_enable(device_t dev, device_t mdev, u_int32_t mode)
269 {
270 	u_int32_t tstatus, mstatus;
271 	u_int32_t command;
272 	int rq, sba, fw, rate, arqsz, cal;
273 
274 	tstatus = pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
275 	mstatus = pci_read_config(mdev, agp_find_caps(mdev) + AGP_STATUS, 4);
276 
277 	/* Set RQ to the min of mode, tstatus and mstatus */
278 	rq = AGP_MODE_GET_RQ(mode);
279 	if (AGP_MODE_GET_RQ(tstatus) < rq)
280 		rq = AGP_MODE_GET_RQ(tstatus);
281 	if (AGP_MODE_GET_RQ(mstatus) < rq)
282 		rq = AGP_MODE_GET_RQ(mstatus);
283 
284 	/*
285 	 * ARQSZ - Set the value to the maximum one.
286 	 * Don't allow the mode register to override values.
287 	 */
288 	arqsz = AGP_MODE_GET_ARQSZ(mode);
289 	if (AGP_MODE_GET_ARQSZ(tstatus) > rq)
290 		rq = AGP_MODE_GET_ARQSZ(tstatus);
291 	if (AGP_MODE_GET_ARQSZ(mstatus) > rq)
292 		rq = AGP_MODE_GET_ARQSZ(mstatus);
293 
294 	/* Calibration cycle - don't allow override by mode register */
295 	cal = AGP_MODE_GET_CAL(tstatus);
296 	if (AGP_MODE_GET_CAL(mstatus) < cal)
297 		cal = AGP_MODE_GET_CAL(mstatus);
298 
299 	/* SBA must be supported for AGP v3. */
300 	sba = 1;
301 
302 	/* Set FW if all three support it. */
303 	fw = (AGP_MODE_GET_FW(tstatus)
304 	       & AGP_MODE_GET_FW(mstatus)
305 	       & AGP_MODE_GET_FW(mode));
306 
307 	/* Figure out the max rate */
308 	rate = (AGP_MODE_GET_RATE(tstatus)
309 		& AGP_MODE_GET_RATE(mstatus)
310 		& AGP_MODE_GET_RATE(mode));
311 	if (rate & AGP_MODE_V3_RATE_8x)
312 		rate = AGP_MODE_V3_RATE_8x;
313 	else
314 		rate = AGP_MODE_V3_RATE_4x;
315 	if (bootverbose)
316 		device_printf(dev, "Setting AGP v3 mode %d\n", rate * 4);
317 
318 	pci_write_config(dev, agp_find_caps(dev) + AGP_COMMAND, 0, 4);
319 
320 	/* Construct the new mode word and tell the hardware */
321 	command = AGP_MODE_SET_RQ(0, rq);
322 	command = AGP_MODE_SET_ARQSZ(command, arqsz);
323 	command = AGP_MODE_SET_CAL(command, cal);
324 	command = AGP_MODE_SET_SBA(command, sba);
325 	command = AGP_MODE_SET_FW(command, fw);
326 	command = AGP_MODE_SET_RATE(command, rate);
327 	command = AGP_MODE_SET_AGP(command, 1);
328 	pci_write_config(dev, agp_find_caps(dev) + AGP_COMMAND, command, 4);
329 	pci_write_config(mdev, agp_find_caps(mdev) + AGP_COMMAND, command, 4);
330 
331 	return 0;
332 }
333 
334 static int
335 agp_v2_enable(device_t dev, device_t mdev, u_int32_t mode)
336 {
337 	u_int32_t tstatus, mstatus;
338 	u_int32_t command;
339 	int rq, sba, fw, rate;
340 
341 	tstatus = pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
342 	mstatus = pci_read_config(mdev, agp_find_caps(mdev) + AGP_STATUS, 4);
343 
344 	/* Set RQ to the min of mode, tstatus and mstatus */
345 	rq = AGP_MODE_GET_RQ(mode);
346 	if (AGP_MODE_GET_RQ(tstatus) < rq)
347 		rq = AGP_MODE_GET_RQ(tstatus);
348 	if (AGP_MODE_GET_RQ(mstatus) < rq)
349 		rq = AGP_MODE_GET_RQ(mstatus);
350 
351 	/* Set SBA if all three can deal with SBA */
352 	sba = (AGP_MODE_GET_SBA(tstatus)
353 	       & AGP_MODE_GET_SBA(mstatus)
354 	       & AGP_MODE_GET_SBA(mode));
355 
356 	/* Similar for FW */
357 	fw = (AGP_MODE_GET_FW(tstatus)
358 	       & AGP_MODE_GET_FW(mstatus)
359 	       & AGP_MODE_GET_FW(mode));
360 
361 	/* Figure out the max rate */
362 	rate = (AGP_MODE_GET_RATE(tstatus)
363 		& AGP_MODE_GET_RATE(mstatus)
364 		& AGP_MODE_GET_RATE(mode));
365 	if (rate & AGP_MODE_V2_RATE_4x)
366 		rate = AGP_MODE_V2_RATE_4x;
367 	else if (rate & AGP_MODE_V2_RATE_2x)
368 		rate = AGP_MODE_V2_RATE_2x;
369 	else
370 		rate = AGP_MODE_V2_RATE_1x;
371 	if (bootverbose)
372 		device_printf(dev, "Setting AGP v2 mode %d\n", rate);
373 
374 	/* Construct the new mode word and tell the hardware */
375 	command = AGP_MODE_SET_RQ(0, rq);
376 	command = AGP_MODE_SET_SBA(command, sba);
377 	command = AGP_MODE_SET_FW(command, fw);
378 	command = AGP_MODE_SET_RATE(command, rate);
379 	command = AGP_MODE_SET_AGP(command, 1);
380 	pci_write_config(dev, agp_find_caps(dev) + AGP_COMMAND, command, 4);
381 	pci_write_config(mdev, agp_find_caps(mdev) + AGP_COMMAND, command, 4);
382 
383 	return 0;
384 }
385 
386 int
387 agp_generic_enable(device_t dev, u_int32_t mode)
388 {
389 	device_t mdev = agp_find_display();
390 	u_int32_t tstatus, mstatus;
391 
392 	if (!mdev) {
393 		AGP_DPF("can't find display\n");
394 		return ENXIO;
395 	}
396 
397 	tstatus = pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
398 	mstatus = pci_read_config(mdev, agp_find_caps(mdev) + AGP_STATUS, 4);
399 
400 	/*
401 	 * Check display and bridge for AGP v3 support.  AGP v3 allows
402 	 * more variety in topology than v2, e.g. multiple AGP devices
403 	 * attached to one bridge, or multiple AGP bridges in one
404 	 * system.  This doesn't attempt to address those situations,
405 	 * but should work fine for a classic single AGP slot system
406 	 * with AGP v3.
407 	 */
408 	if (AGP_MODE_GET_MODE_3(tstatus) && AGP_MODE_GET_MODE_3(mstatus))
409 		return (agp_v3_enable(dev, mdev, mode));
410 	else
411 		return (agp_v2_enable(dev, mdev, mode));
412 }
413 
414 struct agp_memory *
415 agp_generic_alloc_memory(device_t dev, int type, vm_size_t size)
416 {
417 	struct agp_softc *sc = device_get_softc(dev);
418 	struct agp_memory *mem;
419 
420 	if ((size & (AGP_PAGE_SIZE - 1)) != 0)
421 		return 0;
422 
423 	if (sc->as_allocated + size > sc->as_maxmem)
424 		return 0;
425 
426 	if (type != 0) {
427 		printf("agp_generic_alloc_memory: unsupported type %d\n",
428 		       type);
429 		return 0;
430 	}
431 
432 	mem = malloc(sizeof *mem, M_AGP, M_WAITOK);
433 	mem->am_id = sc->as_nextid++;
434 	mem->am_size = size;
435 	mem->am_type = 0;
436 	mem->am_obj = vm_object_allocate(OBJT_DEFAULT, atop(round_page(size)));
437 	mem->am_physical = 0;
438 	mem->am_offset = 0;
439 	mem->am_is_bound = 0;
440 	TAILQ_INSERT_TAIL(&sc->as_memory, mem, am_link);
441 	sc->as_allocated += size;
442 
443 	return mem;
444 }
445 
446 int
447 agp_generic_free_memory(device_t dev, struct agp_memory *mem)
448 {
449 	struct agp_softc *sc = device_get_softc(dev);
450 
451 	if (mem->am_is_bound)
452 		return EBUSY;
453 
454 	sc->as_allocated -= mem->am_size;
455 	TAILQ_REMOVE(&sc->as_memory, mem, am_link);
456 	vm_object_deallocate(mem->am_obj);
457 	free(mem, M_AGP);
458 	return 0;
459 }
460 
461 int
462 agp_generic_bind_memory(device_t dev, struct agp_memory *mem,
463 			vm_offset_t offset)
464 {
465 	struct agp_softc *sc = device_get_softc(dev);
466 	vm_offset_t i, j, k;
467 	vm_page_t m;
468 	int error;
469 
470 	/* Do some sanity checks first. */
471 	if (offset < 0 || (offset & (AGP_PAGE_SIZE - 1)) != 0 ||
472 	    offset + mem->am_size > AGP_GET_APERTURE(dev)) {
473 		device_printf(dev, "binding memory at bad offset %#x\n",
474 		    (int)offset);
475 		return EINVAL;
476 	}
477 
478 	/*
479 	 * Allocate the pages early, before acquiring the lock,
480 	 * because vm_page_grab() used with VM_ALLOC_RETRY may
481 	 * block and we can't hold a mutex while blocking.
482 	 */
483 	VM_OBJECT_LOCK(mem->am_obj);
484 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
485 		/*
486 		 * Find a page from the object and wire it
487 		 * down. This page will be mapped using one or more
488 		 * entries in the GATT (assuming that PAGE_SIZE >=
489 		 * AGP_PAGE_SIZE. If this is the first call to bind,
490 		 * the pages will be allocated and zeroed.
491 		 */
492 		m = vm_page_grab(mem->am_obj, OFF_TO_IDX(i),
493 		    VM_ALLOC_WIRED | VM_ALLOC_ZERO | VM_ALLOC_RETRY);
494 		AGP_DPF("found page pa=%#x\n", VM_PAGE_TO_PHYS(m));
495 	}
496 	VM_OBJECT_UNLOCK(mem->am_obj);
497 
498 	mtx_lock(&sc->as_lock);
499 
500 	if (mem->am_is_bound) {
501 		device_printf(dev, "memory already bound\n");
502 		error = EINVAL;
503 		VM_OBJECT_LOCK(mem->am_obj);
504 		goto bad;
505 	}
506 
507 	/*
508 	 * Bind the individual pages and flush the chipset's
509 	 * TLB.
510 	 *
511 	 * XXX Presumably, this needs to be the pci address on alpha
512 	 * (i.e. use alpha_XXX_dmamap()). I don't have access to any
513 	 * alpha AGP hardware to check.
514 	 */
515 	VM_OBJECT_LOCK(mem->am_obj);
516 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
517 		m = vm_page_lookup(mem->am_obj, OFF_TO_IDX(i));
518 
519 		/*
520 		 * Install entries in the GATT, making sure that if
521 		 * AGP_PAGE_SIZE < PAGE_SIZE and mem->am_size is not
522 		 * aligned to PAGE_SIZE, we don't modify too many GATT
523 		 * entries.
524 		 */
525 		for (j = 0; j < PAGE_SIZE && i + j < mem->am_size;
526 		     j += AGP_PAGE_SIZE) {
527 			vm_offset_t pa = VM_PAGE_TO_PHYS(m) + j;
528 			AGP_DPF("binding offset %#x to pa %#x\n",
529 				offset + i + j, pa);
530 			error = AGP_BIND_PAGE(dev, offset + i + j, pa);
531 			if (error) {
532 				/*
533 				 * Bail out. Reverse all the mappings
534 				 * and unwire the pages.
535 				 */
536 				vm_page_lock_queues();
537 				vm_page_wakeup(m);
538 				vm_page_unlock_queues();
539 				for (k = 0; k < i + j; k += AGP_PAGE_SIZE)
540 					AGP_UNBIND_PAGE(dev, offset + k);
541 				goto bad;
542 			}
543 		}
544 		vm_page_lock_queues();
545 		vm_page_wakeup(m);
546 		vm_page_unlock_queues();
547 	}
548 	VM_OBJECT_UNLOCK(mem->am_obj);
549 
550 	/*
551 	 * Flush the cpu cache since we are providing a new mapping
552 	 * for these pages.
553 	 */
554 	agp_flush_cache();
555 
556 	/*
557 	 * Make sure the chipset gets the new mappings.
558 	 */
559 	AGP_FLUSH_TLB(dev);
560 
561 	mem->am_offset = offset;
562 	mem->am_is_bound = 1;
563 
564 	mtx_unlock(&sc->as_lock);
565 
566 	return 0;
567 bad:
568 	mtx_unlock(&sc->as_lock);
569 	VM_OBJECT_LOCK_ASSERT(mem->am_obj, MA_OWNED);
570 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
571 		m = vm_page_lookup(mem->am_obj, OFF_TO_IDX(i));
572 		vm_page_lock_queues();
573 		vm_page_unwire(m, 0);
574 		vm_page_unlock_queues();
575 	}
576 	VM_OBJECT_UNLOCK(mem->am_obj);
577 
578 	return error;
579 }
580 
581 int
582 agp_generic_unbind_memory(device_t dev, struct agp_memory *mem)
583 {
584 	struct agp_softc *sc = device_get_softc(dev);
585 	vm_page_t m;
586 	int i;
587 
588 	mtx_lock(&sc->as_lock);
589 
590 	if (!mem->am_is_bound) {
591 		device_printf(dev, "memory is not bound\n");
592 		mtx_unlock(&sc->as_lock);
593 		return EINVAL;
594 	}
595 
596 
597 	/*
598 	 * Unbind the individual pages and flush the chipset's
599 	 * TLB. Unwire the pages so they can be swapped.
600 	 */
601 	for (i = 0; i < mem->am_size; i += AGP_PAGE_SIZE)
602 		AGP_UNBIND_PAGE(dev, mem->am_offset + i);
603 	VM_OBJECT_LOCK(mem->am_obj);
604 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
605 		m = vm_page_lookup(mem->am_obj, atop(i));
606 		vm_page_lock_queues();
607 		vm_page_unwire(m, 0);
608 		vm_page_unlock_queues();
609 	}
610 	VM_OBJECT_UNLOCK(mem->am_obj);
611 
612 	agp_flush_cache();
613 	AGP_FLUSH_TLB(dev);
614 
615 	mem->am_offset = 0;
616 	mem->am_is_bound = 0;
617 
618 	mtx_unlock(&sc->as_lock);
619 
620 	return 0;
621 }
622 
623 /* Helper functions for implementing user/kernel api */
624 
625 static int
626 agp_acquire_helper(device_t dev, enum agp_acquire_state state)
627 {
628 	struct agp_softc *sc = device_get_softc(dev);
629 
630 	if (sc->as_state != AGP_ACQUIRE_FREE)
631 		return EBUSY;
632 	sc->as_state = state;
633 
634 	return 0;
635 }
636 
637 static int
638 agp_release_helper(device_t dev, enum agp_acquire_state state)
639 {
640 	struct agp_softc *sc = device_get_softc(dev);
641 
642 	if (sc->as_state == AGP_ACQUIRE_FREE)
643 		return 0;
644 
645 	if (sc->as_state != state)
646 		return EBUSY;
647 
648 	sc->as_state = AGP_ACQUIRE_FREE;
649 	return 0;
650 }
651 
652 static struct agp_memory *
653 agp_find_memory(device_t dev, int id)
654 {
655 	struct agp_softc *sc = device_get_softc(dev);
656 	struct agp_memory *mem;
657 
658 	AGP_DPF("searching for memory block %d\n", id);
659 	TAILQ_FOREACH(mem, &sc->as_memory, am_link) {
660 		AGP_DPF("considering memory block %d\n", mem->am_id);
661 		if (mem->am_id == id)
662 			return mem;
663 	}
664 	return 0;
665 }
666 
667 /* Implementation of the userland ioctl api */
668 
669 static int
670 agp_info_user(device_t dev, agp_info *info)
671 {
672 	struct agp_softc *sc = device_get_softc(dev);
673 
674 	bzero(info, sizeof *info);
675 	info->bridge_id = pci_get_devid(dev);
676 	info->agp_mode =
677 	    pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
678 	info->aper_base = rman_get_start(sc->as_aperture);
679 	info->aper_size = AGP_GET_APERTURE(dev) >> 20;
680 	info->pg_total = info->pg_system = sc->as_maxmem >> AGP_PAGE_SHIFT;
681 	info->pg_used = sc->as_allocated >> AGP_PAGE_SHIFT;
682 
683 	return 0;
684 }
685 
686 static int
687 agp_setup_user(device_t dev, agp_setup *setup)
688 {
689 	return AGP_ENABLE(dev, setup->agp_mode);
690 }
691 
692 static int
693 agp_allocate_user(device_t dev, agp_allocate *alloc)
694 {
695 	struct agp_memory *mem;
696 
697 	mem = AGP_ALLOC_MEMORY(dev,
698 			       alloc->type,
699 			       alloc->pg_count << AGP_PAGE_SHIFT);
700 	if (mem) {
701 		alloc->key = mem->am_id;
702 		alloc->physical = mem->am_physical;
703 		return 0;
704 	} else {
705 		return ENOMEM;
706 	}
707 }
708 
709 static int
710 agp_deallocate_user(device_t dev, int id)
711 {
712 	struct agp_memory *mem = agp_find_memory(dev, id);;
713 
714 	if (mem) {
715 		AGP_FREE_MEMORY(dev, mem);
716 		return 0;
717 	} else {
718 		return ENOENT;
719 	}
720 }
721 
722 static int
723 agp_bind_user(device_t dev, agp_bind *bind)
724 {
725 	struct agp_memory *mem = agp_find_memory(dev, bind->key);
726 
727 	if (!mem)
728 		return ENOENT;
729 
730 	return AGP_BIND_MEMORY(dev, mem, bind->pg_start << AGP_PAGE_SHIFT);
731 }
732 
733 static int
734 agp_unbind_user(device_t dev, agp_unbind *unbind)
735 {
736 	struct agp_memory *mem = agp_find_memory(dev, unbind->key);
737 
738 	if (!mem)
739 		return ENOENT;
740 
741 	return AGP_UNBIND_MEMORY(dev, mem);
742 }
743 
744 static int
745 agp_open(struct cdev *kdev, int oflags, int devtype, struct thread *td)
746 {
747 	device_t dev = KDEV2DEV(kdev);
748 	struct agp_softc *sc = device_get_softc(dev);
749 
750 	if (!sc->as_isopen) {
751 		sc->as_isopen = 1;
752 		device_busy(dev);
753 	}
754 
755 	return 0;
756 }
757 
758 static int
759 agp_close(struct cdev *kdev, int fflag, int devtype, struct thread *td)
760 {
761 	device_t dev = KDEV2DEV(kdev);
762 	struct agp_softc *sc = device_get_softc(dev);
763 	struct agp_memory *mem;
764 
765 	/*
766 	 * Clear the GATT and force release on last close
767 	 */
768 	while ((mem = TAILQ_FIRST(&sc->as_memory)) != 0) {
769 		if (mem->am_is_bound)
770 			AGP_UNBIND_MEMORY(dev, mem);
771 		AGP_FREE_MEMORY(dev, mem);
772 	}
773 	if (sc->as_state == AGP_ACQUIRE_USER)
774 		agp_release_helper(dev, AGP_ACQUIRE_USER);
775 	sc->as_isopen = 0;
776 	device_unbusy(dev);
777 
778 	return 0;
779 }
780 
781 static int
782 agp_ioctl(struct cdev *kdev, u_long cmd, caddr_t data, int fflag, struct thread *td)
783 {
784 	device_t dev = KDEV2DEV(kdev);
785 
786 	switch (cmd) {
787 	case AGPIOC_INFO:
788 		return agp_info_user(dev, (agp_info *) data);
789 
790 	case AGPIOC_ACQUIRE:
791 		return agp_acquire_helper(dev, AGP_ACQUIRE_USER);
792 
793 	case AGPIOC_RELEASE:
794 		return agp_release_helper(dev, AGP_ACQUIRE_USER);
795 
796 	case AGPIOC_SETUP:
797 		return agp_setup_user(dev, (agp_setup *)data);
798 
799 	case AGPIOC_ALLOCATE:
800 		return agp_allocate_user(dev, (agp_allocate *)data);
801 
802 	case AGPIOC_DEALLOCATE:
803 		return agp_deallocate_user(dev, *(int *) data);
804 
805 	case AGPIOC_BIND:
806 		return agp_bind_user(dev, (agp_bind *)data);
807 
808 	case AGPIOC_UNBIND:
809 		return agp_unbind_user(dev, (agp_unbind *)data);
810 
811 	}
812 
813 	return EINVAL;
814 }
815 
816 static int
817 agp_mmap(struct cdev *kdev, vm_offset_t offset, vm_paddr_t *paddr, int prot)
818 {
819 	device_t dev = KDEV2DEV(kdev);
820 	struct agp_softc *sc = device_get_softc(dev);
821 
822 	if (offset > AGP_GET_APERTURE(dev))
823 		return -1;
824 	*paddr = rman_get_start(sc->as_aperture) + offset;
825 	return 0;
826 }
827 
828 /* Implementation of the kernel api */
829 
830 device_t
831 agp_find_device()
832 {
833 	device_t *children, child;
834 	int i, count;
835 
836 	if (!agp_devclass)
837 		return NULL;
838 	if (devclass_get_devices(agp_devclass, &children, &count) != 0)
839 		return NULL;
840 	child = NULL;
841 	for (i = 0; i < count; i++) {
842 		if (device_is_attached(children[i])) {
843 			child = children[i];
844 			break;
845 		}
846 	}
847 	free(children, M_TEMP);
848 	return child;
849 }
850 
851 enum agp_acquire_state
852 agp_state(device_t dev)
853 {
854 	struct agp_softc *sc = device_get_softc(dev);
855 	return sc->as_state;
856 }
857 
858 void
859 agp_get_info(device_t dev, struct agp_info *info)
860 {
861 	struct agp_softc *sc = device_get_softc(dev);
862 
863 	info->ai_mode =
864 		pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
865 	info->ai_aperture_base = rman_get_start(sc->as_aperture);
866 	info->ai_aperture_size = rman_get_size(sc->as_aperture);
867 	info->ai_memory_allowed = sc->as_maxmem;
868 	info->ai_memory_used = sc->as_allocated;
869 }
870 
871 int
872 agp_acquire(device_t dev)
873 {
874 	return agp_acquire_helper(dev, AGP_ACQUIRE_KERNEL);
875 }
876 
877 int
878 agp_release(device_t dev)
879 {
880 	return agp_release_helper(dev, AGP_ACQUIRE_KERNEL);
881 }
882 
883 int
884 agp_enable(device_t dev, u_int32_t mode)
885 {
886 	return AGP_ENABLE(dev, mode);
887 }
888 
889 void *agp_alloc_memory(device_t dev, int type, vm_size_t bytes)
890 {
891 	return  (void *) AGP_ALLOC_MEMORY(dev, type, bytes);
892 }
893 
894 void agp_free_memory(device_t dev, void *handle)
895 {
896 	struct agp_memory *mem = (struct agp_memory *) handle;
897 	AGP_FREE_MEMORY(dev, mem);
898 }
899 
900 int agp_bind_memory(device_t dev, void *handle, vm_offset_t offset)
901 {
902 	struct agp_memory *mem = (struct agp_memory *) handle;
903 	return AGP_BIND_MEMORY(dev, mem, offset);
904 }
905 
906 int agp_unbind_memory(device_t dev, void *handle)
907 {
908 	struct agp_memory *mem = (struct agp_memory *) handle;
909 	return AGP_UNBIND_MEMORY(dev, mem);
910 }
911 
912 void agp_memory_info(device_t dev, void *handle, struct
913 		     agp_memory_info *mi)
914 {
915 	struct agp_memory *mem = (struct agp_memory *) handle;
916 
917 	mi->ami_size = mem->am_size;
918 	mi->ami_physical = mem->am_physical;
919 	mi->ami_offset = mem->am_offset;
920 	mi->ami_is_bound = mem->am_is_bound;
921 }
922