xref: /freebsd/sys/dev/agp/agp.c (revision 8847579c57d6aff2b3371c707dce7a2cee8389aa)
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 }
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 		device_get_children(bus, &kids, &numkids);
122 		for (i = 0; i < numkids; i++) {
123 			dev = kids[i];
124 			if (pci_get_class(dev) == PCIC_DISPLAY
125 			    && pci_get_subclass(dev) == PCIS_DISPLAY_VGA)
126 				if (agp_find_caps(dev)) {
127 					free(kids, M_TEMP);
128 					return dev;
129 				}
130 
131 		}
132 		free(kids, M_TEMP);
133 	}
134 
135 	return 0;
136 }
137 
138 struct agp_gatt *
139 agp_alloc_gatt(device_t dev)
140 {
141 	u_int32_t apsize = AGP_GET_APERTURE(dev);
142 	u_int32_t entries = apsize >> AGP_PAGE_SHIFT;
143 	struct agp_gatt *gatt;
144 
145 	if (bootverbose)
146 		device_printf(dev,
147 			      "allocating GATT for aperture of size %dM\n",
148 			      apsize / (1024*1024));
149 
150 	if (entries == 0) {
151 		device_printf(dev, "bad aperture size\n");
152 		return NULL;
153 	}
154 
155 	gatt = malloc(sizeof(struct agp_gatt), M_AGP, M_NOWAIT);
156 	if (!gatt)
157 		return 0;
158 
159 	gatt->ag_entries = entries;
160 	gatt->ag_virtual = contigmalloc(entries * sizeof(u_int32_t), M_AGP, 0,
161 					0, ~0, PAGE_SIZE, 0);
162 	if (!gatt->ag_virtual) {
163 		if (bootverbose)
164 			device_printf(dev, "contiguous allocation failed\n");
165 		free(gatt, M_AGP);
166 		return 0;
167 	}
168 	bzero(gatt->ag_virtual, entries * sizeof(u_int32_t));
169 	gatt->ag_physical = vtophys((vm_offset_t) gatt->ag_virtual);
170 	agp_flush_cache();
171 
172 	return gatt;
173 }
174 
175 void
176 agp_free_gatt(struct agp_gatt *gatt)
177 {
178 	contigfree(gatt->ag_virtual,
179 		   gatt->ag_entries * sizeof(u_int32_t), M_AGP);
180 	free(gatt, M_AGP);
181 }
182 
183 static int agp_max[][2] = {
184 	{0,	0},
185 	{32,	4},
186 	{64,	28},
187 	{128,	96},
188 	{256,	204},
189 	{512,	440},
190 	{1024,	942},
191 	{2048,	1920},
192 	{4096,	3932}
193 };
194 #define agp_max_size	(sizeof(agp_max) / sizeof(agp_max[0]))
195 
196 int
197 agp_generic_attach(device_t dev)
198 {
199 	struct agp_softc *sc = device_get_softc(dev);
200 	int rid, memsize, i;
201 
202 	/*
203 	 * Find and map the aperture.
204 	 */
205 	rid = AGP_APBASE;
206 	sc->as_aperture = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, 0);
207 	if (!sc->as_aperture)
208 		return ENOMEM;
209 
210 	/*
211 	 * Work out an upper bound for agp memory allocation. This
212 	 * uses a heurisitc table from the Linux driver.
213 	 */
214 	memsize = ptoa(Maxmem) >> 20;
215 	for (i = 0; i < agp_max_size; i++) {
216 		if (memsize <= agp_max[i][0])
217 			break;
218 	}
219 	if (i == agp_max_size) i = agp_max_size - 1;
220 	sc->as_maxmem = agp_max[i][1] << 20U;
221 
222 	/*
223 	 * The lock is used to prevent re-entry to
224 	 * agp_generic_bind_memory() since that function can sleep.
225 	 */
226 	mtx_init(&sc->as_lock, "agp lock", NULL, MTX_DEF);
227 
228 	/*
229 	 * Initialise stuff for the userland device.
230 	 */
231 	agp_devclass = devclass_find("agp");
232 	TAILQ_INIT(&sc->as_memory);
233 	sc->as_nextid = 1;
234 
235 	sc->as_devnode = make_dev(&agp_cdevsw,
236 				  device_get_unit(dev),
237 				  UID_ROOT,
238 				  GID_WHEEL,
239 				  0600,
240 				  "agpgart");
241 
242 	return 0;
243 }
244 
245 int
246 agp_generic_detach(device_t dev)
247 {
248 	struct agp_softc *sc = device_get_softc(dev);
249 
250 	destroy_dev(sc->as_devnode);
251 	bus_release_resource(dev, SYS_RES_MEMORY, AGP_APBASE, sc->as_aperture);
252 	mtx_destroy(&sc->as_lock);
253 	agp_flush_cache();
254 	return 0;
255 }
256 
257 /*
258  * This does the enable logic for v3, with the same topology
259  * restrictions as in place for v2 -- one bus, one device on the bus.
260  */
261 static int
262 agp_v3_enable(device_t dev, device_t mdev, u_int32_t mode)
263 {
264 	u_int32_t tstatus, mstatus;
265 	u_int32_t command;
266 	int rq, sba, fw, rate, arqsz, cal;
267 
268 	tstatus = pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
269 	mstatus = pci_read_config(mdev, agp_find_caps(mdev) + AGP_STATUS, 4);
270 
271 	/* Set RQ to the min of mode, tstatus and mstatus */
272 	rq = AGP_MODE_GET_RQ(mode);
273 	if (AGP_MODE_GET_RQ(tstatus) < rq)
274 		rq = AGP_MODE_GET_RQ(tstatus);
275 	if (AGP_MODE_GET_RQ(mstatus) < rq)
276 		rq = AGP_MODE_GET_RQ(mstatus);
277 
278 	/*
279 	 * ARQSZ - Set the value to the maximum one.
280 	 * Don't allow the mode register to override values.
281 	 */
282 	arqsz = AGP_MODE_GET_ARQSZ(mode);
283 	if (AGP_MODE_GET_ARQSZ(tstatus) > rq)
284 		rq = AGP_MODE_GET_ARQSZ(tstatus);
285 	if (AGP_MODE_GET_ARQSZ(mstatus) > rq)
286 		rq = AGP_MODE_GET_ARQSZ(mstatus);
287 
288 	/* Calibration cycle - don't allow override by mode register */
289 	cal = AGP_MODE_GET_CAL(tstatus);
290 	if (AGP_MODE_GET_CAL(mstatus) < cal)
291 		cal = AGP_MODE_GET_CAL(mstatus);
292 
293 	/* SBA must be supported for AGP v3. */
294 	sba = 1;
295 
296 	/* Set FW if all three support it. */
297 	fw = (AGP_MODE_GET_FW(tstatus)
298 	       & AGP_MODE_GET_FW(mstatus)
299 	       & AGP_MODE_GET_FW(mode));
300 
301 	/* Figure out the max rate */
302 	rate = (AGP_MODE_GET_RATE(tstatus)
303 		& AGP_MODE_GET_RATE(mstatus)
304 		& AGP_MODE_GET_RATE(mode));
305 	if (rate & AGP_MODE_V3_RATE_8x)
306 		rate = AGP_MODE_V3_RATE_8x;
307 	else
308 		rate = AGP_MODE_V3_RATE_4x;
309 	if (bootverbose)
310 		device_printf(dev, "Setting AGP v3 mode %d\n", rate * 4);
311 
312 	pci_write_config(dev, agp_find_caps(dev) + AGP_COMMAND, 0, 4);
313 
314 	/* Construct the new mode word and tell the hardware */
315 	command = AGP_MODE_SET_RQ(0, rq);
316 	command = AGP_MODE_SET_ARQSZ(command, arqsz);
317 	command = AGP_MODE_SET_CAL(command, cal);
318 	command = AGP_MODE_SET_SBA(command, sba);
319 	command = AGP_MODE_SET_FW(command, fw);
320 	command = AGP_MODE_SET_RATE(command, rate);
321 	command = AGP_MODE_SET_AGP(command, 1);
322 	pci_write_config(dev, agp_find_caps(dev) + AGP_COMMAND, command, 4);
323 	pci_write_config(mdev, agp_find_caps(mdev) + AGP_COMMAND, command, 4);
324 
325 	return 0;
326 }
327 
328 static int
329 agp_v2_enable(device_t dev, device_t mdev, u_int32_t mode)
330 {
331 	u_int32_t tstatus, mstatus;
332 	u_int32_t command;
333 	int rq, sba, fw, rate;
334 
335 	tstatus = pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
336 	mstatus = pci_read_config(mdev, agp_find_caps(mdev) + AGP_STATUS, 4);
337 
338 	/* Set RQ to the min of mode, tstatus and mstatus */
339 	rq = AGP_MODE_GET_RQ(mode);
340 	if (AGP_MODE_GET_RQ(tstatus) < rq)
341 		rq = AGP_MODE_GET_RQ(tstatus);
342 	if (AGP_MODE_GET_RQ(mstatus) < rq)
343 		rq = AGP_MODE_GET_RQ(mstatus);
344 
345 	/* Set SBA if all three can deal with SBA */
346 	sba = (AGP_MODE_GET_SBA(tstatus)
347 	       & AGP_MODE_GET_SBA(mstatus)
348 	       & AGP_MODE_GET_SBA(mode));
349 
350 	/* Similar for FW */
351 	fw = (AGP_MODE_GET_FW(tstatus)
352 	       & AGP_MODE_GET_FW(mstatus)
353 	       & AGP_MODE_GET_FW(mode));
354 
355 	/* Figure out the max rate */
356 	rate = (AGP_MODE_GET_RATE(tstatus)
357 		& AGP_MODE_GET_RATE(mstatus)
358 		& AGP_MODE_GET_RATE(mode));
359 	if (rate & AGP_MODE_V2_RATE_4x)
360 		rate = AGP_MODE_V2_RATE_4x;
361 	else if (rate & AGP_MODE_V2_RATE_2x)
362 		rate = AGP_MODE_V2_RATE_2x;
363 	else
364 		rate = AGP_MODE_V2_RATE_1x;
365 	if (bootverbose)
366 		device_printf(dev, "Setting AGP v2 mode %d\n", rate);
367 
368 	/* Construct the new mode word and tell the hardware */
369 	command = AGP_MODE_SET_RQ(0, rq);
370 	command = AGP_MODE_SET_SBA(command, sba);
371 	command = AGP_MODE_SET_FW(command, fw);
372 	command = AGP_MODE_SET_RATE(command, rate);
373 	command = AGP_MODE_SET_AGP(command, 1);
374 	pci_write_config(dev, agp_find_caps(dev) + AGP_COMMAND, command, 4);
375 	pci_write_config(mdev, agp_find_caps(mdev) + AGP_COMMAND, command, 4);
376 
377 	return 0;
378 }
379 
380 int
381 agp_generic_enable(device_t dev, u_int32_t mode)
382 {
383 	device_t mdev = agp_find_display();
384 	u_int32_t tstatus, mstatus;
385 
386 	if (!mdev) {
387 		AGP_DPF("can't find display\n");
388 		return ENXIO;
389 	}
390 
391 	tstatus = pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
392 	mstatus = pci_read_config(mdev, agp_find_caps(mdev) + AGP_STATUS, 4);
393 
394 	/*
395 	 * Check display and bridge for AGP v3 support.  AGP v3 allows
396 	 * more variety in topology than v2, e.g. multiple AGP devices
397 	 * attached to one bridge, or multiple AGP bridges in one
398 	 * system.  This doesn't attempt to address those situations,
399 	 * but should work fine for a classic single AGP slot system
400 	 * with AGP v3.
401 	 */
402 	if (AGP_MODE_GET_MODE_3(tstatus) && AGP_MODE_GET_MODE_3(mstatus))
403 		return (agp_v3_enable(dev, mdev, mode));
404 	else
405 		return (agp_v2_enable(dev, mdev, mode));
406 }
407 
408 struct agp_memory *
409 agp_generic_alloc_memory(device_t dev, int type, vm_size_t size)
410 {
411 	struct agp_softc *sc = device_get_softc(dev);
412 	struct agp_memory *mem;
413 
414 	if ((size & (AGP_PAGE_SIZE - 1)) != 0)
415 		return 0;
416 
417 	if (sc->as_allocated + size > sc->as_maxmem)
418 		return 0;
419 
420 	if (type != 0) {
421 		printf("agp_generic_alloc_memory: unsupported type %d\n",
422 		       type);
423 		return 0;
424 	}
425 
426 	mem = malloc(sizeof *mem, M_AGP, M_WAITOK);
427 	mem->am_id = sc->as_nextid++;
428 	mem->am_size = size;
429 	mem->am_type = 0;
430 	mem->am_obj = vm_object_allocate(OBJT_DEFAULT, atop(round_page(size)));
431 	mem->am_physical = 0;
432 	mem->am_offset = 0;
433 	mem->am_is_bound = 0;
434 	TAILQ_INSERT_TAIL(&sc->as_memory, mem, am_link);
435 	sc->as_allocated += size;
436 
437 	return mem;
438 }
439 
440 int
441 agp_generic_free_memory(device_t dev, struct agp_memory *mem)
442 {
443 	struct agp_softc *sc = device_get_softc(dev);
444 
445 	if (mem->am_is_bound)
446 		return EBUSY;
447 
448 	sc->as_allocated -= mem->am_size;
449 	TAILQ_REMOVE(&sc->as_memory, mem, am_link);
450 	vm_object_deallocate(mem->am_obj);
451 	free(mem, M_AGP);
452 	return 0;
453 }
454 
455 int
456 agp_generic_bind_memory(device_t dev, struct agp_memory *mem,
457 			vm_offset_t offset)
458 {
459 	struct agp_softc *sc = device_get_softc(dev);
460 	vm_offset_t i, j, k;
461 	vm_page_t m;
462 	int error;
463 
464 	/* Do some sanity checks first. */
465 	if (offset < 0 || (offset & (AGP_PAGE_SIZE - 1)) != 0 ||
466 	    offset + mem->am_size > AGP_GET_APERTURE(dev)) {
467 		device_printf(dev, "binding memory at bad offset %#x\n",
468 		    (int)offset);
469 		return EINVAL;
470 	}
471 
472 	/*
473 	 * Allocate the pages early, before acquiring the lock,
474 	 * because vm_page_grab() used with VM_ALLOC_RETRY may
475 	 * block and we can't hold a mutex while blocking.
476 	 */
477 	VM_OBJECT_LOCK(mem->am_obj);
478 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
479 		/*
480 		 * Find a page from the object and wire it
481 		 * down. This page will be mapped using one or more
482 		 * entries in the GATT (assuming that PAGE_SIZE >=
483 		 * AGP_PAGE_SIZE. If this is the first call to bind,
484 		 * the pages will be allocated and zeroed.
485 		 */
486 		m = vm_page_grab(mem->am_obj, OFF_TO_IDX(i),
487 		    VM_ALLOC_WIRED | VM_ALLOC_ZERO | VM_ALLOC_RETRY);
488 		AGP_DPF("found page pa=%#x\n", VM_PAGE_TO_PHYS(m));
489 	}
490 	VM_OBJECT_UNLOCK(mem->am_obj);
491 
492 	mtx_lock(&sc->as_lock);
493 
494 	if (mem->am_is_bound) {
495 		device_printf(dev, "memory already bound\n");
496 		error = EINVAL;
497 		VM_OBJECT_LOCK(mem->am_obj);
498 		goto bad;
499 	}
500 
501 	/*
502 	 * Bind the individual pages and flush the chipset's
503 	 * TLB.
504 	 */
505 	VM_OBJECT_LOCK(mem->am_obj);
506 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
507 		m = vm_page_lookup(mem->am_obj, OFF_TO_IDX(i));
508 
509 		/*
510 		 * Install entries in the GATT, making sure that if
511 		 * AGP_PAGE_SIZE < PAGE_SIZE and mem->am_size is not
512 		 * aligned to PAGE_SIZE, we don't modify too many GATT
513 		 * entries.
514 		 */
515 		for (j = 0; j < PAGE_SIZE && i + j < mem->am_size;
516 		     j += AGP_PAGE_SIZE) {
517 			vm_offset_t pa = VM_PAGE_TO_PHYS(m) + j;
518 			AGP_DPF("binding offset %#x to pa %#x\n",
519 				offset + i + j, pa);
520 			error = AGP_BIND_PAGE(dev, offset + i + j, pa);
521 			if (error) {
522 				/*
523 				 * Bail out. Reverse all the mappings
524 				 * and unwire the pages.
525 				 */
526 				vm_page_lock_queues();
527 				vm_page_wakeup(m);
528 				vm_page_unlock_queues();
529 				for (k = 0; k < i + j; k += AGP_PAGE_SIZE)
530 					AGP_UNBIND_PAGE(dev, offset + k);
531 				goto bad;
532 			}
533 		}
534 		vm_page_lock_queues();
535 		vm_page_wakeup(m);
536 		vm_page_unlock_queues();
537 	}
538 	VM_OBJECT_UNLOCK(mem->am_obj);
539 
540 	/*
541 	 * Flush the cpu cache since we are providing a new mapping
542 	 * for these pages.
543 	 */
544 	agp_flush_cache();
545 
546 	/*
547 	 * Make sure the chipset gets the new mappings.
548 	 */
549 	AGP_FLUSH_TLB(dev);
550 
551 	mem->am_offset = offset;
552 	mem->am_is_bound = 1;
553 
554 	mtx_unlock(&sc->as_lock);
555 
556 	return 0;
557 bad:
558 	mtx_unlock(&sc->as_lock);
559 	VM_OBJECT_LOCK_ASSERT(mem->am_obj, MA_OWNED);
560 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
561 		m = vm_page_lookup(mem->am_obj, OFF_TO_IDX(i));
562 		vm_page_lock_queues();
563 		vm_page_unwire(m, 0);
564 		vm_page_unlock_queues();
565 	}
566 	VM_OBJECT_UNLOCK(mem->am_obj);
567 
568 	return error;
569 }
570 
571 int
572 agp_generic_unbind_memory(device_t dev, struct agp_memory *mem)
573 {
574 	struct agp_softc *sc = device_get_softc(dev);
575 	vm_page_t m;
576 	int i;
577 
578 	mtx_lock(&sc->as_lock);
579 
580 	if (!mem->am_is_bound) {
581 		device_printf(dev, "memory is not bound\n");
582 		mtx_unlock(&sc->as_lock);
583 		return EINVAL;
584 	}
585 
586 
587 	/*
588 	 * Unbind the individual pages and flush the chipset's
589 	 * TLB. Unwire the pages so they can be swapped.
590 	 */
591 	for (i = 0; i < mem->am_size; i += AGP_PAGE_SIZE)
592 		AGP_UNBIND_PAGE(dev, mem->am_offset + i);
593 	VM_OBJECT_LOCK(mem->am_obj);
594 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
595 		m = vm_page_lookup(mem->am_obj, atop(i));
596 		vm_page_lock_queues();
597 		vm_page_unwire(m, 0);
598 		vm_page_unlock_queues();
599 	}
600 	VM_OBJECT_UNLOCK(mem->am_obj);
601 
602 	agp_flush_cache();
603 	AGP_FLUSH_TLB(dev);
604 
605 	mem->am_offset = 0;
606 	mem->am_is_bound = 0;
607 
608 	mtx_unlock(&sc->as_lock);
609 
610 	return 0;
611 }
612 
613 /* Helper functions for implementing user/kernel api */
614 
615 static int
616 agp_acquire_helper(device_t dev, enum agp_acquire_state state)
617 {
618 	struct agp_softc *sc = device_get_softc(dev);
619 
620 	if (sc->as_state != AGP_ACQUIRE_FREE)
621 		return EBUSY;
622 	sc->as_state = state;
623 
624 	return 0;
625 }
626 
627 static int
628 agp_release_helper(device_t dev, enum agp_acquire_state state)
629 {
630 	struct agp_softc *sc = device_get_softc(dev);
631 
632 	if (sc->as_state == AGP_ACQUIRE_FREE)
633 		return 0;
634 
635 	if (sc->as_state != state)
636 		return EBUSY;
637 
638 	sc->as_state = AGP_ACQUIRE_FREE;
639 	return 0;
640 }
641 
642 static struct agp_memory *
643 agp_find_memory(device_t dev, int id)
644 {
645 	struct agp_softc *sc = device_get_softc(dev);
646 	struct agp_memory *mem;
647 
648 	AGP_DPF("searching for memory block %d\n", id);
649 	TAILQ_FOREACH(mem, &sc->as_memory, am_link) {
650 		AGP_DPF("considering memory block %d\n", mem->am_id);
651 		if (mem->am_id == id)
652 			return mem;
653 	}
654 	return 0;
655 }
656 
657 /* Implementation of the userland ioctl api */
658 
659 static int
660 agp_info_user(device_t dev, agp_info *info)
661 {
662 	struct agp_softc *sc = device_get_softc(dev);
663 
664 	bzero(info, sizeof *info);
665 	info->bridge_id = pci_get_devid(dev);
666 	info->agp_mode =
667 	    pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
668 	info->aper_base = rman_get_start(sc->as_aperture);
669 	info->aper_size = AGP_GET_APERTURE(dev) >> 20;
670 	info->pg_total = info->pg_system = sc->as_maxmem >> AGP_PAGE_SHIFT;
671 	info->pg_used = sc->as_allocated >> AGP_PAGE_SHIFT;
672 
673 	return 0;
674 }
675 
676 static int
677 agp_setup_user(device_t dev, agp_setup *setup)
678 {
679 	return AGP_ENABLE(dev, setup->agp_mode);
680 }
681 
682 static int
683 agp_allocate_user(device_t dev, agp_allocate *alloc)
684 {
685 	struct agp_memory *mem;
686 
687 	mem = AGP_ALLOC_MEMORY(dev,
688 			       alloc->type,
689 			       alloc->pg_count << AGP_PAGE_SHIFT);
690 	if (mem) {
691 		alloc->key = mem->am_id;
692 		alloc->physical = mem->am_physical;
693 		return 0;
694 	} else {
695 		return ENOMEM;
696 	}
697 }
698 
699 static int
700 agp_deallocate_user(device_t dev, int id)
701 {
702 	struct agp_memory *mem = agp_find_memory(dev, id);;
703 
704 	if (mem) {
705 		AGP_FREE_MEMORY(dev, mem);
706 		return 0;
707 	} else {
708 		return ENOENT;
709 	}
710 }
711 
712 static int
713 agp_bind_user(device_t dev, agp_bind *bind)
714 {
715 	struct agp_memory *mem = agp_find_memory(dev, bind->key);
716 
717 	if (!mem)
718 		return ENOENT;
719 
720 	return AGP_BIND_MEMORY(dev, mem, bind->pg_start << AGP_PAGE_SHIFT);
721 }
722 
723 static int
724 agp_unbind_user(device_t dev, agp_unbind *unbind)
725 {
726 	struct agp_memory *mem = agp_find_memory(dev, unbind->key);
727 
728 	if (!mem)
729 		return ENOENT;
730 
731 	return AGP_UNBIND_MEMORY(dev, mem);
732 }
733 
734 static int
735 agp_open(struct cdev *kdev, int oflags, int devtype, struct thread *td)
736 {
737 	device_t dev = KDEV2DEV(kdev);
738 	struct agp_softc *sc = device_get_softc(dev);
739 
740 	if (!sc->as_isopen) {
741 		sc->as_isopen = 1;
742 		device_busy(dev);
743 	}
744 
745 	return 0;
746 }
747 
748 static int
749 agp_close(struct cdev *kdev, int fflag, int devtype, struct thread *td)
750 {
751 	device_t dev = KDEV2DEV(kdev);
752 	struct agp_softc *sc = device_get_softc(dev);
753 	struct agp_memory *mem;
754 
755 	/*
756 	 * Clear the GATT and force release on last close
757 	 */
758 	while ((mem = TAILQ_FIRST(&sc->as_memory)) != 0) {
759 		if (mem->am_is_bound)
760 			AGP_UNBIND_MEMORY(dev, mem);
761 		AGP_FREE_MEMORY(dev, mem);
762 	}
763 	if (sc->as_state == AGP_ACQUIRE_USER)
764 		agp_release_helper(dev, AGP_ACQUIRE_USER);
765 	sc->as_isopen = 0;
766 	device_unbusy(dev);
767 
768 	return 0;
769 }
770 
771 static int
772 agp_ioctl(struct cdev *kdev, u_long cmd, caddr_t data, int fflag, struct thread *td)
773 {
774 	device_t dev = KDEV2DEV(kdev);
775 
776 	switch (cmd) {
777 	case AGPIOC_INFO:
778 		return agp_info_user(dev, (agp_info *) data);
779 
780 	case AGPIOC_ACQUIRE:
781 		return agp_acquire_helper(dev, AGP_ACQUIRE_USER);
782 
783 	case AGPIOC_RELEASE:
784 		return agp_release_helper(dev, AGP_ACQUIRE_USER);
785 
786 	case AGPIOC_SETUP:
787 		return agp_setup_user(dev, (agp_setup *)data);
788 
789 	case AGPIOC_ALLOCATE:
790 		return agp_allocate_user(dev, (agp_allocate *)data);
791 
792 	case AGPIOC_DEALLOCATE:
793 		return agp_deallocate_user(dev, *(int *) data);
794 
795 	case AGPIOC_BIND:
796 		return agp_bind_user(dev, (agp_bind *)data);
797 
798 	case AGPIOC_UNBIND:
799 		return agp_unbind_user(dev, (agp_unbind *)data);
800 
801 	}
802 
803 	return EINVAL;
804 }
805 
806 static int
807 agp_mmap(struct cdev *kdev, vm_offset_t offset, vm_paddr_t *paddr, int prot)
808 {
809 	device_t dev = KDEV2DEV(kdev);
810 	struct agp_softc *sc = device_get_softc(dev);
811 
812 	if (offset > AGP_GET_APERTURE(dev))
813 		return -1;
814 	*paddr = rman_get_start(sc->as_aperture) + offset;
815 	return 0;
816 }
817 
818 /* Implementation of the kernel api */
819 
820 device_t
821 agp_find_device()
822 {
823 	device_t *children, child;
824 	int i, count;
825 
826 	if (!agp_devclass)
827 		return NULL;
828 	if (devclass_get_devices(agp_devclass, &children, &count) != 0)
829 		return NULL;
830 	child = NULL;
831 	for (i = 0; i < count; i++) {
832 		if (device_is_attached(children[i])) {
833 			child = children[i];
834 			break;
835 		}
836 	}
837 	free(children, M_TEMP);
838 	return child;
839 }
840 
841 enum agp_acquire_state
842 agp_state(device_t dev)
843 {
844 	struct agp_softc *sc = device_get_softc(dev);
845 	return sc->as_state;
846 }
847 
848 void
849 agp_get_info(device_t dev, struct agp_info *info)
850 {
851 	struct agp_softc *sc = device_get_softc(dev);
852 
853 	info->ai_mode =
854 		pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
855 	info->ai_aperture_base = rman_get_start(sc->as_aperture);
856 	info->ai_aperture_size = rman_get_size(sc->as_aperture);
857 	info->ai_memory_allowed = sc->as_maxmem;
858 	info->ai_memory_used = sc->as_allocated;
859 }
860 
861 int
862 agp_acquire(device_t dev)
863 {
864 	return agp_acquire_helper(dev, AGP_ACQUIRE_KERNEL);
865 }
866 
867 int
868 agp_release(device_t dev)
869 {
870 	return agp_release_helper(dev, AGP_ACQUIRE_KERNEL);
871 }
872 
873 int
874 agp_enable(device_t dev, u_int32_t mode)
875 {
876 	return AGP_ENABLE(dev, mode);
877 }
878 
879 void *agp_alloc_memory(device_t dev, int type, vm_size_t bytes)
880 {
881 	return  (void *) AGP_ALLOC_MEMORY(dev, type, bytes);
882 }
883 
884 void agp_free_memory(device_t dev, void *handle)
885 {
886 	struct agp_memory *mem = (struct agp_memory *) handle;
887 	AGP_FREE_MEMORY(dev, mem);
888 }
889 
890 int agp_bind_memory(device_t dev, void *handle, vm_offset_t offset)
891 {
892 	struct agp_memory *mem = (struct agp_memory *) handle;
893 	return AGP_BIND_MEMORY(dev, mem, offset);
894 }
895 
896 int agp_unbind_memory(device_t dev, void *handle)
897 {
898 	struct agp_memory *mem = (struct agp_memory *) handle;
899 	return AGP_UNBIND_MEMORY(dev, mem);
900 }
901 
902 void agp_memory_info(device_t dev, void *handle, struct
903 		     agp_memory_info *mi)
904 {
905 	struct agp_memory *mem = (struct agp_memory *) handle;
906 
907 	mi->ami_size = mem->am_size;
908 	mi->ami_physical = mem->am_physical;
909 	mi->ami_offset = mem->am_offset;
910 	mi->ami_is_bound = mem->am_is_bound;
911 }
912