xref: /freebsd/sys/dev/agp/agp.c (revision 7899f917b1c0ea178f1d2be0cfb452086d079d23)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2000 Doug Rabson
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 #include "opt_agp.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 #include <sys/rwlock.h>
45 
46 #include <dev/agp/agppriv.h>
47 #include <dev/agp/agpvar.h>
48 #include <dev/agp/agpreg.h>
49 #include <dev/pci/pcivar.h>
50 #include <dev/pci/pcireg.h>
51 
52 #include <vm/vm.h>
53 #include <vm/vm_extern.h>
54 #include <vm/vm_kern.h>
55 #include <vm/vm_param.h>
56 #include <vm/vm_object.h>
57 #include <vm/vm_page.h>
58 #include <vm/vm_pageout.h>
59 #include <vm/pmap.h>
60 
61 #include <machine/bus.h>
62 #include <machine/resource.h>
63 #include <sys/rman.h>
64 
65 MODULE_VERSION(agp, 1);
66 
67 MALLOC_DEFINE(M_AGP, "agp", "AGP data structures");
68 
69 				/* agp_drv.c */
70 static d_open_t agp_open;
71 static d_close_t agp_close;
72 static d_ioctl_t agp_ioctl;
73 static d_mmap_t agp_mmap;
74 
75 static struct cdevsw agp_cdevsw = {
76 	.d_version =	D_VERSION,
77 	.d_flags =	D_NEEDGIANT,
78 	.d_open =	agp_open,
79 	.d_close =	agp_close,
80 	.d_ioctl =	agp_ioctl,
81 	.d_mmap =	agp_mmap,
82 	.d_name =	"agp",
83 };
84 
85 static devclass_t agp_devclass;
86 
87 /* Helper functions for implementing chipset mini drivers. */
88 
89 u_int8_t
90 agp_find_caps(device_t dev)
91 {
92 	int capreg;
93 
94 	if (pci_find_cap(dev, PCIY_AGP, &capreg) != 0)
95 		capreg = 0;
96 	return (capreg);
97 }
98 
99 /*
100  * Find an AGP display device (if any).
101  */
102 static device_t
103 agp_find_display(void)
104 {
105 	devclass_t pci = devclass_find("pci");
106 	device_t bus, dev = 0;
107 	device_t *kids;
108 	int busnum, numkids, i;
109 
110 	for (busnum = 0; busnum < devclass_get_maxunit(pci); busnum++) {
111 		bus = devclass_get_device(pci, busnum);
112 		if (!bus)
113 			continue;
114 		if (device_get_children(bus, &kids, &numkids) != 0)
115 			continue;
116 		for (i = 0; i < numkids; i++) {
117 			dev = kids[i];
118 			if (pci_get_class(dev) == PCIC_DISPLAY
119 			    && pci_get_subclass(dev) == PCIS_DISPLAY_VGA)
120 				if (agp_find_caps(dev)) {
121 					free(kids, M_TEMP);
122 					return dev;
123 				}
124 
125 		}
126 		free(kids, M_TEMP);
127 	}
128 
129 	return 0;
130 }
131 
132 struct agp_gatt *
133 agp_alloc_gatt(device_t dev)
134 {
135 	u_int32_t apsize = AGP_GET_APERTURE(dev);
136 	u_int32_t entries = apsize >> AGP_PAGE_SHIFT;
137 	struct agp_gatt *gatt;
138 
139 	if (bootverbose)
140 		device_printf(dev,
141 			      "allocating GATT for aperture of size %dM\n",
142 			      apsize / (1024*1024));
143 
144 	if (entries == 0) {
145 		device_printf(dev, "bad aperture size\n");
146 		return NULL;
147 	}
148 
149 	gatt = malloc(sizeof(struct agp_gatt), M_AGP, M_NOWAIT);
150 	if (!gatt)
151 		return 0;
152 
153 	gatt->ag_entries = entries;
154 	gatt->ag_virtual = kmem_alloc_contig(entries * sizeof(uint32_t),
155 	    M_NOWAIT | M_ZERO, 0, ~0, PAGE_SIZE, 0, VM_MEMATTR_WRITE_COMBINING);
156 	if (!gatt->ag_virtual) {
157 		if (bootverbose)
158 			device_printf(dev, "contiguous allocation failed\n");
159 		free(gatt, M_AGP);
160 		return 0;
161 	}
162 	gatt->ag_physical = vtophys((vm_offset_t) gatt->ag_virtual);
163 
164 	return gatt;
165 }
166 
167 void
168 agp_free_gatt(struct agp_gatt *gatt)
169 {
170 	kmem_free(gatt->ag_virtual, gatt->ag_entries * sizeof(uint32_t));
171 	free(gatt, M_AGP);
172 }
173 
174 static u_int agp_max[][2] = {
175 	{0,	0},
176 	{32,	4},
177 	{64,	28},
178 	{128,	96},
179 	{256,	204},
180 	{512,	440},
181 	{1024,	942},
182 	{2048,	1920},
183 	{4096,	3932}
184 };
185 #define	AGP_MAX_SIZE	nitems(agp_max)
186 
187 /**
188  * Sets the PCI resource which represents the AGP aperture.
189  *
190  * If not called, the default AGP aperture resource of AGP_APBASE will
191  * be used.  Must be called before agp_generic_attach().
192  */
193 void
194 agp_set_aperture_resource(device_t dev, int rid)
195 {
196 	struct agp_softc *sc = device_get_softc(dev);
197 
198 	sc->as_aperture_rid = rid;
199 }
200 
201 int
202 agp_generic_attach(device_t dev)
203 {
204 	struct make_dev_args mdargs;
205 	struct agp_softc *sc = device_get_softc(dev);
206 	int error, i, unit;
207 	u_int memsize;
208 
209 	/*
210 	 * Find and map the aperture, RF_SHAREABLE for DRM but not RF_ACTIVE
211 	 * because the kernel doesn't need to map it.
212 	 */
213 
214 	if (sc->as_aperture_rid != -1) {
215 		if (sc->as_aperture_rid == 0)
216 			sc->as_aperture_rid = AGP_APBASE;
217 
218 		sc->as_aperture = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
219 		    &sc->as_aperture_rid, RF_SHAREABLE);
220 		if (!sc->as_aperture)
221 			return ENOMEM;
222 	}
223 
224 	/*
225 	 * Work out an upper bound for agp memory allocation. This
226 	 * uses a heurisitc table from the Linux driver.
227 	 */
228 	memsize = ptoa(realmem) >> 20;
229 	for (i = 0; i < AGP_MAX_SIZE; i++) {
230 		if (memsize <= agp_max[i][0])
231 			break;
232 	}
233 	if (i == AGP_MAX_SIZE)
234 		i = AGP_MAX_SIZE - 1;
235 	sc->as_maxmem = agp_max[i][1] << 20U;
236 
237 	/*
238 	 * The lock is used to prevent re-entry to
239 	 * agp_generic_bind_memory() since that function can sleep.
240 	 */
241 	mtx_init(&sc->as_lock, "agp lock", NULL, MTX_DEF);
242 
243 	/*
244 	 * Initialise stuff for the userland device.
245 	 */
246 	agp_devclass = devclass_find("agp");
247 	TAILQ_INIT(&sc->as_memory);
248 	sc->as_nextid = 1;
249 
250 	sc->as_devalias = NULL;
251 
252 	make_dev_args_init(&mdargs);
253 	mdargs.mda_devsw = &agp_cdevsw;
254 	mdargs.mda_uid = UID_ROOT;
255 	mdargs.mda_gid = GID_WHEEL;
256 	mdargs.mda_mode = 0600;
257 	mdargs.mda_si_drv1 = dev;
258 	mdargs.mda_si_drv2 = NULL;
259 
260 	unit = device_get_unit(dev);
261 	error = make_dev_s(&mdargs, &sc->as_devnode, "agpgart%d", unit);
262 	if (error == 0) {
263 		/*
264 		 * Create an alias for the first device that shows up.
265 		 */
266 		if (unit == 0) {
267 			(void)make_dev_alias_p(MAKEDEV_CHECKNAME,
268 			    &sc->as_devalias, sc->as_devnode, "agpgart");
269 		}
270 	} else {
271 		agp_free_res(dev);
272 	}
273 
274 	return error;
275 }
276 
277 void
278 agp_free_cdev(device_t dev)
279 {
280 	struct agp_softc *sc = device_get_softc(dev);
281 
282 	destroy_dev(sc->as_devnode);
283 	if (sc->as_devalias != NULL)
284 		destroy_dev(sc->as_devalias);
285 }
286 
287 void
288 agp_free_res(device_t dev)
289 {
290 	struct agp_softc *sc = device_get_softc(dev);
291 
292 	if (sc->as_aperture != NULL)
293 		bus_release_resource(dev, SYS_RES_MEMORY, sc->as_aperture_rid,
294 		    sc->as_aperture);
295 	mtx_destroy(&sc->as_lock);
296 }
297 
298 int
299 agp_generic_detach(device_t dev)
300 {
301 
302 	agp_free_cdev(dev);
303 	agp_free_res(dev);
304 	return 0;
305 }
306 
307 /**
308  * Default AGP aperture size detection which simply returns the size of
309  * the aperture's PCI resource.
310  */
311 u_int32_t
312 agp_generic_get_aperture(device_t dev)
313 {
314 	struct agp_softc *sc = device_get_softc(dev);
315 
316 	return rman_get_size(sc->as_aperture);
317 }
318 
319 /**
320  * Default AGP aperture size setting function, which simply doesn't allow
321  * changes to resource size.
322  */
323 int
324 agp_generic_set_aperture(device_t dev, u_int32_t aperture)
325 {
326 	u_int32_t current_aperture;
327 
328 	current_aperture = AGP_GET_APERTURE(dev);
329 	if (current_aperture != aperture)
330 		return EINVAL;
331 	else
332 		return 0;
333 }
334 
335 /*
336  * This does the enable logic for v3, with the same topology
337  * restrictions as in place for v2 -- one bus, one device on the bus.
338  */
339 static int
340 agp_v3_enable(device_t dev, device_t mdev, u_int32_t mode)
341 {
342 	u_int32_t tstatus, mstatus;
343 	u_int32_t command;
344 	int rq, sba, fw, rate, arqsz, cal;
345 
346 	tstatus = pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
347 	mstatus = pci_read_config(mdev, agp_find_caps(mdev) + AGP_STATUS, 4);
348 
349 	/* Set RQ to the min of mode, tstatus and mstatus */
350 	rq = AGP_MODE_GET_RQ(mode);
351 	if (AGP_MODE_GET_RQ(tstatus) < rq)
352 		rq = AGP_MODE_GET_RQ(tstatus);
353 	if (AGP_MODE_GET_RQ(mstatus) < rq)
354 		rq = AGP_MODE_GET_RQ(mstatus);
355 
356 	/*
357 	 * ARQSZ - Set the value to the maximum one.
358 	 * Don't allow the mode register to override values.
359 	 */
360 	arqsz = AGP_MODE_GET_ARQSZ(mode);
361 	if (AGP_MODE_GET_ARQSZ(tstatus) > rq)
362 		rq = AGP_MODE_GET_ARQSZ(tstatus);
363 	if (AGP_MODE_GET_ARQSZ(mstatus) > rq)
364 		rq = AGP_MODE_GET_ARQSZ(mstatus);
365 
366 	/* Calibration cycle - don't allow override by mode register */
367 	cal = AGP_MODE_GET_CAL(tstatus);
368 	if (AGP_MODE_GET_CAL(mstatus) < cal)
369 		cal = AGP_MODE_GET_CAL(mstatus);
370 
371 	/* SBA must be supported for AGP v3. */
372 	sba = 1;
373 
374 	/* Set FW if all three support it. */
375 	fw = (AGP_MODE_GET_FW(tstatus)
376 	       & AGP_MODE_GET_FW(mstatus)
377 	       & AGP_MODE_GET_FW(mode));
378 
379 	/* Figure out the max rate */
380 	rate = (AGP_MODE_GET_RATE(tstatus)
381 		& AGP_MODE_GET_RATE(mstatus)
382 		& AGP_MODE_GET_RATE(mode));
383 	if (rate & AGP_MODE_V3_RATE_8x)
384 		rate = AGP_MODE_V3_RATE_8x;
385 	else
386 		rate = AGP_MODE_V3_RATE_4x;
387 	if (bootverbose)
388 		device_printf(dev, "Setting AGP v3 mode %d\n", rate * 4);
389 
390 	pci_write_config(dev, agp_find_caps(dev) + AGP_COMMAND, 0, 4);
391 
392 	/* Construct the new mode word and tell the hardware */
393 	command = 0;
394 	command = AGP_MODE_SET_RQ(0, rq);
395 	command = AGP_MODE_SET_ARQSZ(command, arqsz);
396 	command = AGP_MODE_SET_CAL(command, cal);
397 	command = AGP_MODE_SET_SBA(command, sba);
398 	command = AGP_MODE_SET_FW(command, fw);
399 	command = AGP_MODE_SET_RATE(command, rate);
400 	command = AGP_MODE_SET_MODE_3(command, 1);
401 	command = AGP_MODE_SET_AGP(command, 1);
402 	pci_write_config(dev, agp_find_caps(dev) + AGP_COMMAND, command, 4);
403 	pci_write_config(mdev, agp_find_caps(mdev) + AGP_COMMAND, command, 4);
404 
405 	return 0;
406 }
407 
408 static int
409 agp_v2_enable(device_t dev, device_t mdev, u_int32_t mode)
410 {
411 	u_int32_t tstatus, mstatus;
412 	u_int32_t command;
413 	int rq, sba, fw, rate;
414 
415 	tstatus = pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
416 	mstatus = pci_read_config(mdev, agp_find_caps(mdev) + AGP_STATUS, 4);
417 
418 	/* Set RQ to the min of mode, tstatus and mstatus */
419 	rq = AGP_MODE_GET_RQ(mode);
420 	if (AGP_MODE_GET_RQ(tstatus) < rq)
421 		rq = AGP_MODE_GET_RQ(tstatus);
422 	if (AGP_MODE_GET_RQ(mstatus) < rq)
423 		rq = AGP_MODE_GET_RQ(mstatus);
424 
425 	/* Set SBA if all three can deal with SBA */
426 	sba = (AGP_MODE_GET_SBA(tstatus)
427 	       & AGP_MODE_GET_SBA(mstatus)
428 	       & AGP_MODE_GET_SBA(mode));
429 
430 	/* Similar for FW */
431 	fw = (AGP_MODE_GET_FW(tstatus)
432 	       & AGP_MODE_GET_FW(mstatus)
433 	       & AGP_MODE_GET_FW(mode));
434 
435 	/* Figure out the max rate */
436 	rate = (AGP_MODE_GET_RATE(tstatus)
437 		& AGP_MODE_GET_RATE(mstatus)
438 		& AGP_MODE_GET_RATE(mode));
439 	if (rate & AGP_MODE_V2_RATE_4x)
440 		rate = AGP_MODE_V2_RATE_4x;
441 	else if (rate & AGP_MODE_V2_RATE_2x)
442 		rate = AGP_MODE_V2_RATE_2x;
443 	else
444 		rate = AGP_MODE_V2_RATE_1x;
445 	if (bootverbose)
446 		device_printf(dev, "Setting AGP v2 mode %d\n", rate);
447 
448 	/* Construct the new mode word and tell the hardware */
449 	command = 0;
450 	command = AGP_MODE_SET_RQ(0, rq);
451 	command = AGP_MODE_SET_SBA(command, sba);
452 	command = AGP_MODE_SET_FW(command, fw);
453 	command = AGP_MODE_SET_RATE(command, rate);
454 	command = AGP_MODE_SET_AGP(command, 1);
455 	pci_write_config(dev, agp_find_caps(dev) + AGP_COMMAND, command, 4);
456 	pci_write_config(mdev, agp_find_caps(mdev) + AGP_COMMAND, command, 4);
457 
458 	return 0;
459 }
460 
461 int
462 agp_generic_enable(device_t dev, u_int32_t mode)
463 {
464 	device_t mdev = agp_find_display();
465 	u_int32_t tstatus, mstatus;
466 
467 	if (!mdev) {
468 		AGP_DPF("can't find display\n");
469 		return ENXIO;
470 	}
471 
472 	tstatus = pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
473 	mstatus = pci_read_config(mdev, agp_find_caps(mdev) + AGP_STATUS, 4);
474 
475 	/*
476 	 * Check display and bridge for AGP v3 support.  AGP v3 allows
477 	 * more variety in topology than v2, e.g. multiple AGP devices
478 	 * attached to one bridge, or multiple AGP bridges in one
479 	 * system.  This doesn't attempt to address those situations,
480 	 * but should work fine for a classic single AGP slot system
481 	 * with AGP v3.
482 	 */
483 	if (AGP_MODE_GET_MODE_3(mode) &&
484 	    AGP_MODE_GET_MODE_3(tstatus) &&
485 	    AGP_MODE_GET_MODE_3(mstatus))
486 		return (agp_v3_enable(dev, mdev, mode));
487 	else
488 		return (agp_v2_enable(dev, mdev, mode));
489 }
490 
491 struct agp_memory *
492 agp_generic_alloc_memory(device_t dev, int type, vm_size_t size)
493 {
494 	struct agp_softc *sc = device_get_softc(dev);
495 	struct agp_memory *mem;
496 
497 	if ((size & (AGP_PAGE_SIZE - 1)) != 0)
498 		return 0;
499 
500 	if (size > sc->as_maxmem - sc->as_allocated)
501 		return 0;
502 
503 	if (type != 0) {
504 		printf("agp_generic_alloc_memory: unsupported type %d\n",
505 		       type);
506 		return 0;
507 	}
508 
509 	mem = malloc(sizeof *mem, M_AGP, M_WAITOK);
510 	mem->am_id = sc->as_nextid++;
511 	mem->am_size = size;
512 	mem->am_type = 0;
513 	mem->am_obj = vm_object_allocate(OBJT_SWAP, atop(round_page(size)));
514 	mem->am_physical = 0;
515 	mem->am_offset = 0;
516 	mem->am_is_bound = 0;
517 	TAILQ_INSERT_TAIL(&sc->as_memory, mem, am_link);
518 	sc->as_allocated += size;
519 
520 	return mem;
521 }
522 
523 int
524 agp_generic_free_memory(device_t dev, struct agp_memory *mem)
525 {
526 	struct agp_softc *sc = device_get_softc(dev);
527 
528 	if (mem->am_is_bound)
529 		return EBUSY;
530 
531 	sc->as_allocated -= mem->am_size;
532 	TAILQ_REMOVE(&sc->as_memory, mem, am_link);
533 	vm_object_deallocate(mem->am_obj);
534 	free(mem, M_AGP);
535 	return 0;
536 }
537 
538 int
539 agp_generic_bind_memory(device_t dev, struct agp_memory *mem,
540 			vm_offset_t offset)
541 {
542 	struct agp_softc *sc = device_get_softc(dev);
543 	vm_offset_t i, j, k;
544 	vm_page_t m;
545 	int error;
546 
547 	/* Do some sanity checks first. */
548 	if ((offset & (AGP_PAGE_SIZE - 1)) != 0 ||
549 	    offset + mem->am_size > AGP_GET_APERTURE(dev)) {
550 		device_printf(dev, "binding memory at bad offset %#x\n",
551 		    (int)offset);
552 		return EINVAL;
553 	}
554 
555 	/*
556 	 * Allocate the pages early, before acquiring the lock,
557 	 * because vm_page_grab() may sleep and we can't hold a mutex
558 	 * while sleeping.
559 	 */
560 	VM_OBJECT_WLOCK(mem->am_obj);
561 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
562 		/*
563 		 * Find a page from the object and wire it
564 		 * down. This page will be mapped using one or more
565 		 * entries in the GATT (assuming that PAGE_SIZE >=
566 		 * AGP_PAGE_SIZE. If this is the first call to bind,
567 		 * the pages will be allocated and zeroed.
568 		 */
569 		m = vm_page_grab(mem->am_obj, OFF_TO_IDX(i),
570 		    VM_ALLOC_WIRED | VM_ALLOC_ZERO);
571 		AGP_DPF("found page pa=%#jx\n", (uintmax_t)VM_PAGE_TO_PHYS(m));
572 	}
573 	VM_OBJECT_WUNLOCK(mem->am_obj);
574 
575 	mtx_lock(&sc->as_lock);
576 
577 	if (mem->am_is_bound) {
578 		device_printf(dev, "memory already bound\n");
579 		error = EINVAL;
580 		VM_OBJECT_WLOCK(mem->am_obj);
581 		i = 0;
582 		goto bad;
583 	}
584 
585 	/*
586 	 * Bind the individual pages and flush the chipset's
587 	 * TLB.
588 	 */
589 	VM_OBJECT_WLOCK(mem->am_obj);
590 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
591 		m = vm_page_lookup(mem->am_obj, OFF_TO_IDX(i));
592 
593 		/*
594 		 * Install entries in the GATT, making sure that if
595 		 * AGP_PAGE_SIZE < PAGE_SIZE and mem->am_size is not
596 		 * aligned to PAGE_SIZE, we don't modify too many GATT
597 		 * entries.
598 		 */
599 		for (j = 0; j < PAGE_SIZE && i + j < mem->am_size;
600 		     j += AGP_PAGE_SIZE) {
601 			vm_offset_t pa = VM_PAGE_TO_PHYS(m) + j;
602 			AGP_DPF("binding offset %#jx to pa %#jx\n",
603 				(uintmax_t)offset + i + j, (uintmax_t)pa);
604 			error = AGP_BIND_PAGE(dev, offset + i + j, pa);
605 			if (error) {
606 				/*
607 				 * Bail out. Reverse all the mappings
608 				 * and unwire the pages.
609 				 */
610 				for (k = 0; k < i + j; k += AGP_PAGE_SIZE)
611 					AGP_UNBIND_PAGE(dev, offset + k);
612 				goto bad;
613 			}
614 		}
615 		vm_page_xunbusy(m);
616 	}
617 	VM_OBJECT_WUNLOCK(mem->am_obj);
618 
619 	/*
620 	 * Make sure the chipset gets the new mappings.
621 	 */
622 	AGP_FLUSH_TLB(dev);
623 
624 	mem->am_offset = offset;
625 	mem->am_is_bound = 1;
626 
627 	mtx_unlock(&sc->as_lock);
628 
629 	return 0;
630 bad:
631 	mtx_unlock(&sc->as_lock);
632 	VM_OBJECT_ASSERT_WLOCKED(mem->am_obj);
633 	for (k = 0; k < mem->am_size; k += PAGE_SIZE) {
634 		m = vm_page_lookup(mem->am_obj, OFF_TO_IDX(k));
635 		if (k >= i)
636 			vm_page_xunbusy(m);
637 		vm_page_unwire(m, PQ_INACTIVE);
638 	}
639 	VM_OBJECT_WUNLOCK(mem->am_obj);
640 
641 	return error;
642 }
643 
644 int
645 agp_generic_unbind_memory(device_t dev, struct agp_memory *mem)
646 {
647 	struct agp_softc *sc = device_get_softc(dev);
648 	vm_page_t m;
649 	int i;
650 
651 	mtx_lock(&sc->as_lock);
652 
653 	if (!mem->am_is_bound) {
654 		device_printf(dev, "memory is not bound\n");
655 		mtx_unlock(&sc->as_lock);
656 		return EINVAL;
657 	}
658 
659 	/*
660 	 * Unbind the individual pages and flush the chipset's
661 	 * TLB. Unwire the pages so they can be swapped.
662 	 */
663 	for (i = 0; i < mem->am_size; i += AGP_PAGE_SIZE)
664 		AGP_UNBIND_PAGE(dev, mem->am_offset + i);
665 
666 	AGP_FLUSH_TLB(dev);
667 
668 	VM_OBJECT_WLOCK(mem->am_obj);
669 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
670 		m = vm_page_lookup(mem->am_obj, atop(i));
671 		vm_page_unwire(m, PQ_INACTIVE);
672 	}
673 	VM_OBJECT_WUNLOCK(mem->am_obj);
674 
675 	mem->am_offset = 0;
676 	mem->am_is_bound = 0;
677 
678 	mtx_unlock(&sc->as_lock);
679 
680 	return 0;
681 }
682 
683 /* Helper functions for implementing user/kernel api */
684 
685 static int
686 agp_acquire_helper(device_t dev, enum agp_acquire_state state)
687 {
688 	struct agp_softc *sc = device_get_softc(dev);
689 
690 	if (sc->as_state != AGP_ACQUIRE_FREE)
691 		return EBUSY;
692 	sc->as_state = state;
693 
694 	return 0;
695 }
696 
697 static int
698 agp_release_helper(device_t dev, enum agp_acquire_state state)
699 {
700 	struct agp_softc *sc = device_get_softc(dev);
701 
702 	if (sc->as_state == AGP_ACQUIRE_FREE)
703 		return 0;
704 
705 	if (sc->as_state != state)
706 		return EBUSY;
707 
708 	sc->as_state = AGP_ACQUIRE_FREE;
709 	return 0;
710 }
711 
712 static struct agp_memory *
713 agp_find_memory(device_t dev, int id)
714 {
715 	struct agp_softc *sc = device_get_softc(dev);
716 	struct agp_memory *mem;
717 
718 	AGP_DPF("searching for memory block %d\n", id);
719 	TAILQ_FOREACH(mem, &sc->as_memory, am_link) {
720 		AGP_DPF("considering memory block %d\n", mem->am_id);
721 		if (mem->am_id == id)
722 			return mem;
723 	}
724 	return 0;
725 }
726 
727 /* Implementation of the userland ioctl api */
728 
729 static int
730 agp_info_user(device_t dev, agp_info *info)
731 {
732 	struct agp_softc *sc = device_get_softc(dev);
733 
734 	bzero(info, sizeof *info);
735 	info->bridge_id = pci_get_devid(dev);
736 	info->agp_mode =
737 	    pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
738 	if (sc->as_aperture)
739 		info->aper_base = rman_get_start(sc->as_aperture);
740 	else
741 		info->aper_base = 0;
742 	info->aper_size = AGP_GET_APERTURE(dev) >> 20;
743 	info->pg_total = info->pg_system = sc->as_maxmem >> AGP_PAGE_SHIFT;
744 	info->pg_used = sc->as_allocated >> AGP_PAGE_SHIFT;
745 
746 	return 0;
747 }
748 
749 static int
750 agp_setup_user(device_t dev, agp_setup *setup)
751 {
752 	return AGP_ENABLE(dev, setup->agp_mode);
753 }
754 
755 static int
756 agp_allocate_user(device_t dev, agp_allocate *alloc)
757 {
758 	struct agp_memory *mem;
759 
760 	mem = AGP_ALLOC_MEMORY(dev,
761 			       alloc->type,
762 			       alloc->pg_count << AGP_PAGE_SHIFT);
763 	if (mem) {
764 		alloc->key = mem->am_id;
765 		alloc->physical = mem->am_physical;
766 		return 0;
767 	} else {
768 		return ENOMEM;
769 	}
770 }
771 
772 static int
773 agp_deallocate_user(device_t dev, int id)
774 {
775 	struct agp_memory *mem = agp_find_memory(dev, id);
776 
777 	if (mem) {
778 		AGP_FREE_MEMORY(dev, mem);
779 		return 0;
780 	} else {
781 		return ENOENT;
782 	}
783 }
784 
785 static int
786 agp_bind_user(device_t dev, agp_bind *bind)
787 {
788 	struct agp_memory *mem = agp_find_memory(dev, bind->key);
789 
790 	if (!mem)
791 		return ENOENT;
792 
793 	return AGP_BIND_MEMORY(dev, mem, bind->pg_start << AGP_PAGE_SHIFT);
794 }
795 
796 static int
797 agp_unbind_user(device_t dev, agp_unbind *unbind)
798 {
799 	struct agp_memory *mem = agp_find_memory(dev, unbind->key);
800 
801 	if (!mem)
802 		return ENOENT;
803 
804 	return AGP_UNBIND_MEMORY(dev, mem);
805 }
806 
807 static int
808 agp_chipset_flush(device_t dev)
809 {
810 
811 	return (AGP_CHIPSET_FLUSH(dev));
812 }
813 
814 static int
815 agp_open(struct cdev *kdev, int oflags, int devtype, struct thread *td)
816 {
817 	device_t dev = kdev->si_drv1;
818 	struct agp_softc *sc = device_get_softc(dev);
819 
820 	if (!sc->as_isopen) {
821 		sc->as_isopen = 1;
822 		device_busy(dev);
823 	}
824 
825 	return 0;
826 }
827 
828 static int
829 agp_close(struct cdev *kdev, int fflag, int devtype, struct thread *td)
830 {
831 	device_t dev = kdev->si_drv1;
832 	struct agp_softc *sc = device_get_softc(dev);
833 	struct agp_memory *mem;
834 
835 	/*
836 	 * Clear the GATT and force release on last close
837 	 */
838 	while ((mem = TAILQ_FIRST(&sc->as_memory)) != NULL) {
839 		if (mem->am_is_bound)
840 			AGP_UNBIND_MEMORY(dev, mem);
841 		AGP_FREE_MEMORY(dev, mem);
842 	}
843 	if (sc->as_state == AGP_ACQUIRE_USER)
844 		agp_release_helper(dev, AGP_ACQUIRE_USER);
845 	sc->as_isopen = 0;
846 	device_unbusy(dev);
847 
848 	return 0;
849 }
850 
851 static int
852 agp_ioctl(struct cdev *kdev, u_long cmd, caddr_t data, int fflag, struct thread *td)
853 {
854 	device_t dev = kdev->si_drv1;
855 
856 	switch (cmd) {
857 	case AGPIOC_INFO:
858 		return agp_info_user(dev, (agp_info *) data);
859 
860 	case AGPIOC_ACQUIRE:
861 		return agp_acquire_helper(dev, AGP_ACQUIRE_USER);
862 
863 	case AGPIOC_RELEASE:
864 		return agp_release_helper(dev, AGP_ACQUIRE_USER);
865 
866 	case AGPIOC_SETUP:
867 		return agp_setup_user(dev, (agp_setup *)data);
868 
869 	case AGPIOC_ALLOCATE:
870 		return agp_allocate_user(dev, (agp_allocate *)data);
871 
872 	case AGPIOC_DEALLOCATE:
873 		return agp_deallocate_user(dev, *(int *) data);
874 
875 	case AGPIOC_BIND:
876 		return agp_bind_user(dev, (agp_bind *)data);
877 
878 	case AGPIOC_UNBIND:
879 		return agp_unbind_user(dev, (agp_unbind *)data);
880 
881 	case AGPIOC_CHIPSET_FLUSH:
882 		return agp_chipset_flush(dev);
883 	}
884 
885 	return EINVAL;
886 }
887 
888 static int
889 agp_mmap(struct cdev *kdev, vm_ooffset_t offset, vm_paddr_t *paddr,
890     int prot, vm_memattr_t *memattr)
891 {
892 	device_t dev = kdev->si_drv1;
893 	struct agp_softc *sc = device_get_softc(dev);
894 
895 	if (offset > AGP_GET_APERTURE(dev))
896 		return -1;
897 	if (sc->as_aperture == NULL)
898 		return -1;
899 	*paddr = rman_get_start(sc->as_aperture) + offset;
900 	return 0;
901 }
902 
903 /* Implementation of the kernel api */
904 
905 device_t
906 agp_find_device(void)
907 {
908 	device_t *children, child;
909 	int i, count;
910 
911 	if (!agp_devclass)
912 		return NULL;
913 	if (devclass_get_devices(agp_devclass, &children, &count) != 0)
914 		return NULL;
915 	child = NULL;
916 	for (i = 0; i < count; i++) {
917 		if (device_is_attached(children[i])) {
918 			child = children[i];
919 			break;
920 		}
921 	}
922 	free(children, M_TEMP);
923 	return child;
924 }
925 
926 enum agp_acquire_state
927 agp_state(device_t dev)
928 {
929 	struct agp_softc *sc = device_get_softc(dev);
930 	return sc->as_state;
931 }
932 
933 void
934 agp_get_info(device_t dev, struct agp_info *info)
935 {
936 	struct agp_softc *sc = device_get_softc(dev);
937 
938 	info->ai_mode =
939 		pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
940 	if (sc->as_aperture != NULL)
941 		info->ai_aperture_base = rman_get_start(sc->as_aperture);
942 	else
943 		info->ai_aperture_base = 0;
944 	info->ai_aperture_size = AGP_GET_APERTURE(dev);
945 	info->ai_memory_allowed = sc->as_maxmem;
946 	info->ai_memory_used = sc->as_allocated;
947 }
948 
949 int
950 agp_acquire(device_t dev)
951 {
952 	return agp_acquire_helper(dev, AGP_ACQUIRE_KERNEL);
953 }
954 
955 int
956 agp_release(device_t dev)
957 {
958 	return agp_release_helper(dev, AGP_ACQUIRE_KERNEL);
959 }
960 
961 int
962 agp_enable(device_t dev, u_int32_t mode)
963 {
964 	return AGP_ENABLE(dev, mode);
965 }
966 
967 void *agp_alloc_memory(device_t dev, int type, vm_size_t bytes)
968 {
969 	return  (void *) AGP_ALLOC_MEMORY(dev, type, bytes);
970 }
971 
972 void agp_free_memory(device_t dev, void *handle)
973 {
974 	struct agp_memory *mem = (struct agp_memory *) handle;
975 	AGP_FREE_MEMORY(dev, mem);
976 }
977 
978 int agp_bind_memory(device_t dev, void *handle, vm_offset_t offset)
979 {
980 	struct agp_memory *mem = (struct agp_memory *) handle;
981 	return AGP_BIND_MEMORY(dev, mem, offset);
982 }
983 
984 int agp_unbind_memory(device_t dev, void *handle)
985 {
986 	struct agp_memory *mem = (struct agp_memory *) handle;
987 	return AGP_UNBIND_MEMORY(dev, mem);
988 }
989 
990 void agp_memory_info(device_t dev, void *handle, struct
991 		     agp_memory_info *mi)
992 {
993 	struct agp_memory *mem = (struct agp_memory *) handle;
994 
995 	mi->ami_size = mem->am_size;
996 	mi->ami_physical = mem->am_physical;
997 	mi->ami_offset = mem->am_offset;
998 	mi->ami_is_bound = mem->am_is_bound;
999 }
1000 
1001 int
1002 agp_bind_pages(device_t dev, vm_page_t *pages, vm_size_t size,
1003     vm_offset_t offset)
1004 {
1005 	struct agp_softc *sc;
1006 	vm_offset_t i, j, k, pa;
1007 	vm_page_t m;
1008 	int error;
1009 
1010 	if ((size & (AGP_PAGE_SIZE - 1)) != 0 ||
1011 	    (offset & (AGP_PAGE_SIZE - 1)) != 0)
1012 		return (EINVAL);
1013 
1014 	sc = device_get_softc(dev);
1015 
1016 	mtx_lock(&sc->as_lock);
1017 	for (i = 0; i < size; i += PAGE_SIZE) {
1018 		m = pages[OFF_TO_IDX(i)];
1019 		KASSERT(vm_page_wired(m),
1020 		    ("agp_bind_pages: page %p hasn't been wired", m));
1021 
1022 		/*
1023 		 * Install entries in the GATT, making sure that if
1024 		 * AGP_PAGE_SIZE < PAGE_SIZE and size is not
1025 		 * aligned to PAGE_SIZE, we don't modify too many GATT
1026 		 * entries.
1027 		 */
1028 		for (j = 0; j < PAGE_SIZE && i + j < size; j += AGP_PAGE_SIZE) {
1029 			pa = VM_PAGE_TO_PHYS(m) + j;
1030 			AGP_DPF("binding offset %#jx to pa %#jx\n",
1031 				(uintmax_t)offset + i + j, (uintmax_t)pa);
1032 			error = AGP_BIND_PAGE(dev, offset + i + j, pa);
1033 			if (error) {
1034 				/*
1035 				 * Bail out. Reverse all the mappings.
1036 				 */
1037 				for (k = 0; k < i + j; k += AGP_PAGE_SIZE)
1038 					AGP_UNBIND_PAGE(dev, offset + k);
1039 
1040 				mtx_unlock(&sc->as_lock);
1041 				return (error);
1042 			}
1043 		}
1044 	}
1045 
1046 	AGP_FLUSH_TLB(dev);
1047 
1048 	mtx_unlock(&sc->as_lock);
1049 	return (0);
1050 }
1051 
1052 int
1053 agp_unbind_pages(device_t dev, vm_size_t size, vm_offset_t offset)
1054 {
1055 	struct agp_softc *sc;
1056 	vm_offset_t i;
1057 
1058 	if ((size & (AGP_PAGE_SIZE - 1)) != 0 ||
1059 	    (offset & (AGP_PAGE_SIZE - 1)) != 0)
1060 		return (EINVAL);
1061 
1062 	sc = device_get_softc(dev);
1063 
1064 	mtx_lock(&sc->as_lock);
1065 	for (i = 0; i < size; i += AGP_PAGE_SIZE)
1066 		AGP_UNBIND_PAGE(dev, offset + i);
1067 
1068 	AGP_FLUSH_TLB(dev);
1069 
1070 	mtx_unlock(&sc->as_lock);
1071 	return (0);
1072 }
1073