xref: /freebsd/sys/dev/agp/agp.c (revision bfe691b2f75de2224c7ceb304ebcdef2b42d4179)
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 u_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, i;
201 	u_int memsize;
202 
203 	/*
204 	 * Find and map the aperture.
205 	 */
206 	rid = AGP_APBASE;
207 	sc->as_aperture = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, 0);
208 	if (!sc->as_aperture)
209 		return ENOMEM;
210 
211 	/*
212 	 * Work out an upper bound for agp memory allocation. This
213 	 * uses a heurisitc table from the Linux driver.
214 	 */
215 	memsize = ptoa(Maxmem) >> 20;
216 	for (i = 0; i < agp_max_size; i++) {
217 		if (memsize <= agp_max[i][0])
218 			break;
219 	}
220 	if (i == agp_max_size) i = agp_max_size - 1;
221 	sc->as_maxmem = agp_max[i][1] << 20U;
222 
223 	/*
224 	 * The lock is used to prevent re-entry to
225 	 * agp_generic_bind_memory() since that function can sleep.
226 	 */
227 	mtx_init(&sc->as_lock, "agp lock", NULL, MTX_DEF);
228 
229 	/*
230 	 * Initialise stuff for the userland device.
231 	 */
232 	agp_devclass = devclass_find("agp");
233 	TAILQ_INIT(&sc->as_memory);
234 	sc->as_nextid = 1;
235 
236 	sc->as_devnode = make_dev(&agp_cdevsw,
237 				  device_get_unit(dev),
238 				  UID_ROOT,
239 				  GID_WHEEL,
240 				  0600,
241 				  "agpgart");
242 
243 	return 0;
244 }
245 
246 int
247 agp_generic_detach(device_t dev)
248 {
249 	struct agp_softc *sc = device_get_softc(dev);
250 
251 	destroy_dev(sc->as_devnode);
252 	bus_release_resource(dev, SYS_RES_MEMORY, AGP_APBASE, sc->as_aperture);
253 	mtx_destroy(&sc->as_lock);
254 	agp_flush_cache();
255 	return 0;
256 }
257 
258 /*
259  * This does the enable logic for v3, with the same topology
260  * restrictions as in place for v2 -- one bus, one device on the bus.
261  */
262 static int
263 agp_v3_enable(device_t dev, device_t mdev, u_int32_t mode)
264 {
265 	u_int32_t tstatus, mstatus;
266 	u_int32_t command;
267 	int rq, sba, fw, rate, arqsz, cal;
268 
269 	tstatus = pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
270 	mstatus = pci_read_config(mdev, agp_find_caps(mdev) + AGP_STATUS, 4);
271 
272 	/* Set RQ to the min of mode, tstatus and mstatus */
273 	rq = AGP_MODE_GET_RQ(mode);
274 	if (AGP_MODE_GET_RQ(tstatus) < rq)
275 		rq = AGP_MODE_GET_RQ(tstatus);
276 	if (AGP_MODE_GET_RQ(mstatus) < rq)
277 		rq = AGP_MODE_GET_RQ(mstatus);
278 
279 	/*
280 	 * ARQSZ - Set the value to the maximum one.
281 	 * Don't allow the mode register to override values.
282 	 */
283 	arqsz = AGP_MODE_GET_ARQSZ(mode);
284 	if (AGP_MODE_GET_ARQSZ(tstatus) > rq)
285 		rq = AGP_MODE_GET_ARQSZ(tstatus);
286 	if (AGP_MODE_GET_ARQSZ(mstatus) > rq)
287 		rq = AGP_MODE_GET_ARQSZ(mstatus);
288 
289 	/* Calibration cycle - don't allow override by mode register */
290 	cal = AGP_MODE_GET_CAL(tstatus);
291 	if (AGP_MODE_GET_CAL(mstatus) < cal)
292 		cal = AGP_MODE_GET_CAL(mstatus);
293 
294 	/* SBA must be supported for AGP v3. */
295 	sba = 1;
296 
297 	/* Set FW if all three support it. */
298 	fw = (AGP_MODE_GET_FW(tstatus)
299 	       & AGP_MODE_GET_FW(mstatus)
300 	       & AGP_MODE_GET_FW(mode));
301 
302 	/* Figure out the max rate */
303 	rate = (AGP_MODE_GET_RATE(tstatus)
304 		& AGP_MODE_GET_RATE(mstatus)
305 		& AGP_MODE_GET_RATE(mode));
306 	if (rate & AGP_MODE_V3_RATE_8x)
307 		rate = AGP_MODE_V3_RATE_8x;
308 	else
309 		rate = AGP_MODE_V3_RATE_4x;
310 	if (bootverbose)
311 		device_printf(dev, "Setting AGP v3 mode %d\n", rate * 4);
312 
313 	pci_write_config(dev, agp_find_caps(dev) + AGP_COMMAND, 0, 4);
314 
315 	/* Construct the new mode word and tell the hardware */
316 	command = 0;
317 	command = AGP_MODE_SET_RQ(0, rq);
318 	command = AGP_MODE_SET_ARQSZ(command, arqsz);
319 	command = AGP_MODE_SET_CAL(command, cal);
320 	command = AGP_MODE_SET_SBA(command, sba);
321 	command = AGP_MODE_SET_FW(command, fw);
322 	command = AGP_MODE_SET_RATE(command, rate);
323 	command = AGP_MODE_SET_MODE_3(command, 1);
324 	command = AGP_MODE_SET_AGP(command, 1);
325 	pci_write_config(dev, agp_find_caps(dev) + AGP_COMMAND, command, 4);
326 	pci_write_config(mdev, agp_find_caps(mdev) + AGP_COMMAND, command, 4);
327 
328 	return 0;
329 }
330 
331 static int
332 agp_v2_enable(device_t dev, device_t mdev, u_int32_t mode)
333 {
334 	u_int32_t tstatus, mstatus;
335 	u_int32_t command;
336 	int rq, sba, fw, rate;
337 
338 	tstatus = pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
339 	mstatus = pci_read_config(mdev, agp_find_caps(mdev) + AGP_STATUS, 4);
340 
341 	/* Set RQ to the min of mode, tstatus and mstatus */
342 	rq = AGP_MODE_GET_RQ(mode);
343 	if (AGP_MODE_GET_RQ(tstatus) < rq)
344 		rq = AGP_MODE_GET_RQ(tstatus);
345 	if (AGP_MODE_GET_RQ(mstatus) < rq)
346 		rq = AGP_MODE_GET_RQ(mstatus);
347 
348 	/* Set SBA if all three can deal with SBA */
349 	sba = (AGP_MODE_GET_SBA(tstatus)
350 	       & AGP_MODE_GET_SBA(mstatus)
351 	       & AGP_MODE_GET_SBA(mode));
352 
353 	/* Similar for FW */
354 	fw = (AGP_MODE_GET_FW(tstatus)
355 	       & AGP_MODE_GET_FW(mstatus)
356 	       & AGP_MODE_GET_FW(mode));
357 
358 	/* Figure out the max rate */
359 	rate = (AGP_MODE_GET_RATE(tstatus)
360 		& AGP_MODE_GET_RATE(mstatus)
361 		& AGP_MODE_GET_RATE(mode));
362 	if (rate & AGP_MODE_V2_RATE_4x)
363 		rate = AGP_MODE_V2_RATE_4x;
364 	else if (rate & AGP_MODE_V2_RATE_2x)
365 		rate = AGP_MODE_V2_RATE_2x;
366 	else
367 		rate = AGP_MODE_V2_RATE_1x;
368 	if (bootverbose)
369 		device_printf(dev, "Setting AGP v2 mode %d\n", rate);
370 
371 	/* Construct the new mode word and tell the hardware */
372 	command = 0;
373 	command = AGP_MODE_SET_RQ(0, rq);
374 	command = AGP_MODE_SET_SBA(command, sba);
375 	command = AGP_MODE_SET_FW(command, fw);
376 	command = AGP_MODE_SET_RATE(command, rate);
377 	command = AGP_MODE_SET_AGP(command, 1);
378 	pci_write_config(dev, agp_find_caps(dev) + AGP_COMMAND, command, 4);
379 	pci_write_config(mdev, agp_find_caps(mdev) + AGP_COMMAND, command, 4);
380 
381 	return 0;
382 }
383 
384 int
385 agp_generic_enable(device_t dev, u_int32_t mode)
386 {
387 	device_t mdev = agp_find_display();
388 	u_int32_t tstatus, mstatus;
389 
390 	if (!mdev) {
391 		AGP_DPF("can't find display\n");
392 		return ENXIO;
393 	}
394 
395 	tstatus = pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
396 	mstatus = pci_read_config(mdev, agp_find_caps(mdev) + AGP_STATUS, 4);
397 
398 	/*
399 	 * Check display and bridge for AGP v3 support.  AGP v3 allows
400 	 * more variety in topology than v2, e.g. multiple AGP devices
401 	 * attached to one bridge, or multiple AGP bridges in one
402 	 * system.  This doesn't attempt to address those situations,
403 	 * but should work fine for a classic single AGP slot system
404 	 * with AGP v3.
405 	 */
406 	if (AGP_MODE_GET_MODE_3(mode) &&
407 	    AGP_MODE_GET_MODE_3(tstatus) &&
408 	    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 	VM_OBJECT_LOCK(mem->am_obj);
512 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
513 		m = vm_page_lookup(mem->am_obj, OFF_TO_IDX(i));
514 
515 		/*
516 		 * Install entries in the GATT, making sure that if
517 		 * AGP_PAGE_SIZE < PAGE_SIZE and mem->am_size is not
518 		 * aligned to PAGE_SIZE, we don't modify too many GATT
519 		 * entries.
520 		 */
521 		for (j = 0; j < PAGE_SIZE && i + j < mem->am_size;
522 		     j += AGP_PAGE_SIZE) {
523 			vm_offset_t pa = VM_PAGE_TO_PHYS(m) + j;
524 			AGP_DPF("binding offset %#x to pa %#x\n",
525 				offset + i + j, pa);
526 			error = AGP_BIND_PAGE(dev, offset + i + j, pa);
527 			if (error) {
528 				/*
529 				 * Bail out. Reverse all the mappings
530 				 * and unwire the pages.
531 				 */
532 				vm_page_wakeup(m);
533 				for (k = 0; k < i + j; k += AGP_PAGE_SIZE)
534 					AGP_UNBIND_PAGE(dev, offset + k);
535 				goto bad;
536 			}
537 		}
538 		vm_page_wakeup(m);
539 	}
540 	VM_OBJECT_UNLOCK(mem->am_obj);
541 
542 	/*
543 	 * Flush the cpu cache since we are providing a new mapping
544 	 * for these pages.
545 	 */
546 	agp_flush_cache();
547 
548 	/*
549 	 * Make sure the chipset gets the new mappings.
550 	 */
551 	AGP_FLUSH_TLB(dev);
552 
553 	mem->am_offset = offset;
554 	mem->am_is_bound = 1;
555 
556 	mtx_unlock(&sc->as_lock);
557 
558 	return 0;
559 bad:
560 	mtx_unlock(&sc->as_lock);
561 	VM_OBJECT_LOCK_ASSERT(mem->am_obj, MA_OWNED);
562 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
563 		m = vm_page_lookup(mem->am_obj, OFF_TO_IDX(i));
564 		vm_page_lock_queues();
565 		vm_page_unwire(m, 0);
566 		vm_page_unlock_queues();
567 	}
568 	VM_OBJECT_UNLOCK(mem->am_obj);
569 
570 	return error;
571 }
572 
573 int
574 agp_generic_unbind_memory(device_t dev, struct agp_memory *mem)
575 {
576 	struct agp_softc *sc = device_get_softc(dev);
577 	vm_page_t m;
578 	int i;
579 
580 	mtx_lock(&sc->as_lock);
581 
582 	if (!mem->am_is_bound) {
583 		device_printf(dev, "memory is not bound\n");
584 		mtx_unlock(&sc->as_lock);
585 		return EINVAL;
586 	}
587 
588 
589 	/*
590 	 * Unbind the individual pages and flush the chipset's
591 	 * TLB. Unwire the pages so they can be swapped.
592 	 */
593 	for (i = 0; i < mem->am_size; i += AGP_PAGE_SIZE)
594 		AGP_UNBIND_PAGE(dev, mem->am_offset + i);
595 	VM_OBJECT_LOCK(mem->am_obj);
596 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
597 		m = vm_page_lookup(mem->am_obj, atop(i));
598 		vm_page_lock_queues();
599 		vm_page_unwire(m, 0);
600 		vm_page_unlock_queues();
601 	}
602 	VM_OBJECT_UNLOCK(mem->am_obj);
603 
604 	agp_flush_cache();
605 	AGP_FLUSH_TLB(dev);
606 
607 	mem->am_offset = 0;
608 	mem->am_is_bound = 0;
609 
610 	mtx_unlock(&sc->as_lock);
611 
612 	return 0;
613 }
614 
615 /* Helper functions for implementing user/kernel api */
616 
617 static int
618 agp_acquire_helper(device_t dev, enum agp_acquire_state state)
619 {
620 	struct agp_softc *sc = device_get_softc(dev);
621 
622 	if (sc->as_state != AGP_ACQUIRE_FREE)
623 		return EBUSY;
624 	sc->as_state = state;
625 
626 	return 0;
627 }
628 
629 static int
630 agp_release_helper(device_t dev, enum agp_acquire_state state)
631 {
632 	struct agp_softc *sc = device_get_softc(dev);
633 
634 	if (sc->as_state == AGP_ACQUIRE_FREE)
635 		return 0;
636 
637 	if (sc->as_state != state)
638 		return EBUSY;
639 
640 	sc->as_state = AGP_ACQUIRE_FREE;
641 	return 0;
642 }
643 
644 static struct agp_memory *
645 agp_find_memory(device_t dev, int id)
646 {
647 	struct agp_softc *sc = device_get_softc(dev);
648 	struct agp_memory *mem;
649 
650 	AGP_DPF("searching for memory block %d\n", id);
651 	TAILQ_FOREACH(mem, &sc->as_memory, am_link) {
652 		AGP_DPF("considering memory block %d\n", mem->am_id);
653 		if (mem->am_id == id)
654 			return mem;
655 	}
656 	return 0;
657 }
658 
659 /* Implementation of the userland ioctl api */
660 
661 static int
662 agp_info_user(device_t dev, agp_info *info)
663 {
664 	struct agp_softc *sc = device_get_softc(dev);
665 
666 	bzero(info, sizeof *info);
667 	info->bridge_id = pci_get_devid(dev);
668 	info->agp_mode =
669 	    pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
670 	info->aper_base = rman_get_start(sc->as_aperture);
671 	info->aper_size = AGP_GET_APERTURE(dev) >> 20;
672 	info->pg_total = info->pg_system = sc->as_maxmem >> AGP_PAGE_SHIFT;
673 	info->pg_used = sc->as_allocated >> AGP_PAGE_SHIFT;
674 
675 	return 0;
676 }
677 
678 static int
679 agp_setup_user(device_t dev, agp_setup *setup)
680 {
681 	return AGP_ENABLE(dev, setup->agp_mode);
682 }
683 
684 static int
685 agp_allocate_user(device_t dev, agp_allocate *alloc)
686 {
687 	struct agp_memory *mem;
688 
689 	mem = AGP_ALLOC_MEMORY(dev,
690 			       alloc->type,
691 			       alloc->pg_count << AGP_PAGE_SHIFT);
692 	if (mem) {
693 		alloc->key = mem->am_id;
694 		alloc->physical = mem->am_physical;
695 		return 0;
696 	} else {
697 		return ENOMEM;
698 	}
699 }
700 
701 static int
702 agp_deallocate_user(device_t dev, int id)
703 {
704 	struct agp_memory *mem = agp_find_memory(dev, id);;
705 
706 	if (mem) {
707 		AGP_FREE_MEMORY(dev, mem);
708 		return 0;
709 	} else {
710 		return ENOENT;
711 	}
712 }
713 
714 static int
715 agp_bind_user(device_t dev, agp_bind *bind)
716 {
717 	struct agp_memory *mem = agp_find_memory(dev, bind->key);
718 
719 	if (!mem)
720 		return ENOENT;
721 
722 	return AGP_BIND_MEMORY(dev, mem, bind->pg_start << AGP_PAGE_SHIFT);
723 }
724 
725 static int
726 agp_unbind_user(device_t dev, agp_unbind *unbind)
727 {
728 	struct agp_memory *mem = agp_find_memory(dev, unbind->key);
729 
730 	if (!mem)
731 		return ENOENT;
732 
733 	return AGP_UNBIND_MEMORY(dev, mem);
734 }
735 
736 static int
737 agp_open(struct cdev *kdev, int oflags, int devtype, struct thread *td)
738 {
739 	device_t dev = KDEV2DEV(kdev);
740 	struct agp_softc *sc = device_get_softc(dev);
741 
742 	if (!sc->as_isopen) {
743 		sc->as_isopen = 1;
744 		device_busy(dev);
745 	}
746 
747 	return 0;
748 }
749 
750 static int
751 agp_close(struct cdev *kdev, int fflag, int devtype, struct thread *td)
752 {
753 	device_t dev = KDEV2DEV(kdev);
754 	struct agp_softc *sc = device_get_softc(dev);
755 	struct agp_memory *mem;
756 
757 	/*
758 	 * Clear the GATT and force release on last close
759 	 */
760 	while ((mem = TAILQ_FIRST(&sc->as_memory)) != 0) {
761 		if (mem->am_is_bound)
762 			AGP_UNBIND_MEMORY(dev, mem);
763 		AGP_FREE_MEMORY(dev, mem);
764 	}
765 	if (sc->as_state == AGP_ACQUIRE_USER)
766 		agp_release_helper(dev, AGP_ACQUIRE_USER);
767 	sc->as_isopen = 0;
768 	device_unbusy(dev);
769 
770 	return 0;
771 }
772 
773 static int
774 agp_ioctl(struct cdev *kdev, u_long cmd, caddr_t data, int fflag, struct thread *td)
775 {
776 	device_t dev = KDEV2DEV(kdev);
777 
778 	switch (cmd) {
779 	case AGPIOC_INFO:
780 		return agp_info_user(dev, (agp_info *) data);
781 
782 	case AGPIOC_ACQUIRE:
783 		return agp_acquire_helper(dev, AGP_ACQUIRE_USER);
784 
785 	case AGPIOC_RELEASE:
786 		return agp_release_helper(dev, AGP_ACQUIRE_USER);
787 
788 	case AGPIOC_SETUP:
789 		return agp_setup_user(dev, (agp_setup *)data);
790 
791 	case AGPIOC_ALLOCATE:
792 		return agp_allocate_user(dev, (agp_allocate *)data);
793 
794 	case AGPIOC_DEALLOCATE:
795 		return agp_deallocate_user(dev, *(int *) data);
796 
797 	case AGPIOC_BIND:
798 		return agp_bind_user(dev, (agp_bind *)data);
799 
800 	case AGPIOC_UNBIND:
801 		return agp_unbind_user(dev, (agp_unbind *)data);
802 
803 	}
804 
805 	return EINVAL;
806 }
807 
808 static int
809 agp_mmap(struct cdev *kdev, vm_offset_t offset, vm_paddr_t *paddr, int prot)
810 {
811 	device_t dev = KDEV2DEV(kdev);
812 	struct agp_softc *sc = device_get_softc(dev);
813 
814 	if (offset > AGP_GET_APERTURE(dev))
815 		return -1;
816 	*paddr = rman_get_start(sc->as_aperture) + offset;
817 	return 0;
818 }
819 
820 /* Implementation of the kernel api */
821 
822 device_t
823 agp_find_device()
824 {
825 	device_t *children, child;
826 	int i, count;
827 
828 	if (!agp_devclass)
829 		return NULL;
830 	if (devclass_get_devices(agp_devclass, &children, &count) != 0)
831 		return NULL;
832 	child = NULL;
833 	for (i = 0; i < count; i++) {
834 		if (device_is_attached(children[i])) {
835 			child = children[i];
836 			break;
837 		}
838 	}
839 	free(children, M_TEMP);
840 	return child;
841 }
842 
843 enum agp_acquire_state
844 agp_state(device_t dev)
845 {
846 	struct agp_softc *sc = device_get_softc(dev);
847 	return sc->as_state;
848 }
849 
850 void
851 agp_get_info(device_t dev, struct agp_info *info)
852 {
853 	struct agp_softc *sc = device_get_softc(dev);
854 
855 	info->ai_mode =
856 		pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
857 	info->ai_aperture_base = rman_get_start(sc->as_aperture);
858 	info->ai_aperture_size = rman_get_size(sc->as_aperture);
859 	info->ai_memory_allowed = sc->as_maxmem;
860 	info->ai_memory_used = sc->as_allocated;
861 }
862 
863 int
864 agp_acquire(device_t dev)
865 {
866 	return agp_acquire_helper(dev, AGP_ACQUIRE_KERNEL);
867 }
868 
869 int
870 agp_release(device_t dev)
871 {
872 	return agp_release_helper(dev, AGP_ACQUIRE_KERNEL);
873 }
874 
875 int
876 agp_enable(device_t dev, u_int32_t mode)
877 {
878 	return AGP_ENABLE(dev, mode);
879 }
880 
881 void *agp_alloc_memory(device_t dev, int type, vm_size_t bytes)
882 {
883 	return  (void *) AGP_ALLOC_MEMORY(dev, type, bytes);
884 }
885 
886 void agp_free_memory(device_t dev, void *handle)
887 {
888 	struct agp_memory *mem = (struct agp_memory *) handle;
889 	AGP_FREE_MEMORY(dev, mem);
890 }
891 
892 int agp_bind_memory(device_t dev, void *handle, vm_offset_t offset)
893 {
894 	struct agp_memory *mem = (struct agp_memory *) handle;
895 	return AGP_BIND_MEMORY(dev, mem, offset);
896 }
897 
898 int agp_unbind_memory(device_t dev, void *handle)
899 {
900 	struct agp_memory *mem = (struct agp_memory *) handle;
901 	return AGP_UNBIND_MEMORY(dev, mem);
902 }
903 
904 void agp_memory_info(device_t dev, void *handle, struct
905 		     agp_memory_info *mi)
906 {
907 	struct agp_memory *mem = (struct agp_memory *) handle;
908 
909 	mi->ami_size = mem->am_size;
910 	mi->ami_physical = mem->am_physical;
911 	mi->ami_offset = mem->am_offset;
912 	mi->ami_is_bound = mem->am_is_bound;
913 }
914