xref: /freebsd/sys/dev/agp/agp.c (revision 3c4ba5f55438f7afd4f4b0b56f88f2bb505fd6a6)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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 __FBSDID("$FreeBSD$");
31 
32 #include "opt_agp.h"
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/malloc.h>
37 #include <sys/kernel.h>
38 #include <sys/module.h>
39 #include <sys/bus.h>
40 #include <sys/conf.h>
41 #include <sys/ioccom.h>
42 #include <sys/agpio.h>
43 #include <sys/lock.h>
44 #include <sys/mutex.h>
45 #include <sys/proc.h>
46 #include <sys/rwlock.h>
47 
48 #include <dev/agp/agppriv.h>
49 #include <dev/agp/agpvar.h>
50 #include <dev/agp/agpreg.h>
51 #include <dev/pci/pcivar.h>
52 #include <dev/pci/pcireg.h>
53 
54 #include <vm/vm.h>
55 #include <vm/vm_extern.h>
56 #include <vm/vm_kern.h>
57 #include <vm/vm_param.h>
58 #include <vm/vm_object.h>
59 #include <vm/vm_page.h>
60 #include <vm/vm_pageout.h>
61 #include <vm/pmap.h>
62 
63 #include <machine/bus.h>
64 #include <machine/resource.h>
65 #include <sys/rman.h>
66 
67 MODULE_VERSION(agp, 1);
68 
69 MALLOC_DEFINE(M_AGP, "agp", "AGP data structures");
70 
71 				/* agp_drv.c */
72 static d_open_t agp_open;
73 static d_close_t agp_close;
74 static d_ioctl_t agp_ioctl;
75 static d_mmap_t agp_mmap;
76 
77 static struct cdevsw agp_cdevsw = {
78 	.d_version =	D_VERSION,
79 	.d_flags =	D_NEEDGIANT,
80 	.d_open =	agp_open,
81 	.d_close =	agp_close,
82 	.d_ioctl =	agp_ioctl,
83 	.d_mmap =	agp_mmap,
84 	.d_name =	"agp",
85 };
86 
87 static devclass_t agp_devclass;
88 
89 /* Helper functions for implementing chipset mini drivers. */
90 
91 u_int8_t
92 agp_find_caps(device_t dev)
93 {
94 	int capreg;
95 
96 	if (pci_find_cap(dev, PCIY_AGP, &capreg) != 0)
97 		capreg = 0;
98 	return (capreg);
99 }
100 
101 /*
102  * Find an AGP display device (if any).
103  */
104 static device_t
105 agp_find_display(void)
106 {
107 	devclass_t pci = devclass_find("pci");
108 	device_t bus, dev = 0;
109 	device_t *kids;
110 	int busnum, numkids, i;
111 
112 	for (busnum = 0; busnum < devclass_get_maxunit(pci); busnum++) {
113 		bus = devclass_get_device(pci, busnum);
114 		if (!bus)
115 			continue;
116 		if (device_get_children(bus, &kids, &numkids) != 0)
117 			continue;
118 		for (i = 0; i < numkids; i++) {
119 			dev = kids[i];
120 			if (pci_get_class(dev) == PCIC_DISPLAY
121 			    && pci_get_subclass(dev) == PCIS_DISPLAY_VGA)
122 				if (agp_find_caps(dev)) {
123 					free(kids, M_TEMP);
124 					return dev;
125 				}
126 
127 		}
128 		free(kids, M_TEMP);
129 	}
130 
131 	return 0;
132 }
133 
134 struct agp_gatt *
135 agp_alloc_gatt(device_t dev)
136 {
137 	u_int32_t apsize = AGP_GET_APERTURE(dev);
138 	u_int32_t entries = apsize >> AGP_PAGE_SHIFT;
139 	struct agp_gatt *gatt;
140 
141 	if (bootverbose)
142 		device_printf(dev,
143 			      "allocating GATT for aperture of size %dM\n",
144 			      apsize / (1024*1024));
145 
146 	if (entries == 0) {
147 		device_printf(dev, "bad aperture size\n");
148 		return NULL;
149 	}
150 
151 	gatt = malloc(sizeof(struct agp_gatt), M_AGP, M_NOWAIT);
152 	if (!gatt)
153 		return 0;
154 
155 	gatt->ag_entries = entries;
156 	gatt->ag_virtual = kmem_alloc_contig(entries * sizeof(uint32_t),
157 	    M_NOWAIT | M_ZERO, 0, ~0, PAGE_SIZE, 0, VM_MEMATTR_WRITE_COMBINING);
158 	if (!gatt->ag_virtual) {
159 		if (bootverbose)
160 			device_printf(dev, "contiguous allocation failed\n");
161 		free(gatt, M_AGP);
162 		return 0;
163 	}
164 	gatt->ag_physical = vtophys((vm_offset_t) gatt->ag_virtual);
165 
166 	return gatt;
167 }
168 
169 void
170 agp_free_gatt(struct agp_gatt *gatt)
171 {
172 	kmem_free(gatt->ag_virtual, gatt->ag_entries * sizeof(uint32_t));
173 	free(gatt, M_AGP);
174 }
175 
176 static u_int agp_max[][2] = {
177 	{0,	0},
178 	{32,	4},
179 	{64,	28},
180 	{128,	96},
181 	{256,	204},
182 	{512,	440},
183 	{1024,	942},
184 	{2048,	1920},
185 	{4096,	3932}
186 };
187 #define	AGP_MAX_SIZE	nitems(agp_max)
188 
189 /**
190  * Sets the PCI resource which represents the AGP aperture.
191  *
192  * If not called, the default AGP aperture resource of AGP_APBASE will
193  * be used.  Must be called before agp_generic_attach().
194  */
195 void
196 agp_set_aperture_resource(device_t dev, int rid)
197 {
198 	struct agp_softc *sc = device_get_softc(dev);
199 
200 	sc->as_aperture_rid = rid;
201 }
202 
203 int
204 agp_generic_attach(device_t dev)
205 {
206 	struct make_dev_args mdargs;
207 	struct agp_softc *sc = device_get_softc(dev);
208 	int error, i, unit;
209 	u_int memsize;
210 
211 	/*
212 	 * Find and map the aperture, RF_SHAREABLE for DRM but not RF_ACTIVE
213 	 * because the kernel doesn't need to map it.
214 	 */
215 
216 	if (sc->as_aperture_rid != -1) {
217 		if (sc->as_aperture_rid == 0)
218 			sc->as_aperture_rid = AGP_APBASE;
219 
220 		sc->as_aperture = bus_alloc_resource_any(dev, SYS_RES_MEMORY,
221 		    &sc->as_aperture_rid, RF_SHAREABLE);
222 		if (!sc->as_aperture)
223 			return ENOMEM;
224 	}
225 
226 	/*
227 	 * Work out an upper bound for agp memory allocation. This
228 	 * uses a heurisitc table from the Linux driver.
229 	 */
230 	memsize = ptoa(realmem) >> 20;
231 	for (i = 0; i < AGP_MAX_SIZE; i++) {
232 		if (memsize <= agp_max[i][0])
233 			break;
234 	}
235 	if (i == AGP_MAX_SIZE)
236 		i = AGP_MAX_SIZE - 1;
237 	sc->as_maxmem = agp_max[i][1] << 20U;
238 
239 	/*
240 	 * The lock is used to prevent re-entry to
241 	 * agp_generic_bind_memory() since that function can sleep.
242 	 */
243 	mtx_init(&sc->as_lock, "agp lock", NULL, MTX_DEF);
244 
245 	/*
246 	 * Initialise stuff for the userland device.
247 	 */
248 	agp_devclass = devclass_find("agp");
249 	TAILQ_INIT(&sc->as_memory);
250 	sc->as_nextid = 1;
251 
252 	sc->as_devalias = NULL;
253 
254 	make_dev_args_init(&mdargs);
255 	mdargs.mda_devsw = &agp_cdevsw;
256 	mdargs.mda_uid = UID_ROOT;
257 	mdargs.mda_gid = GID_WHEEL;
258 	mdargs.mda_mode = 0600;
259 	mdargs.mda_si_drv1 = sc;
260 	mdargs.mda_si_drv2 = NULL;
261 
262 	unit = device_get_unit(dev);
263 	error = make_dev_s(&mdargs, &sc->as_devnode, "agpgart%d", unit);
264 	if (error == 0) {
265 		/*
266 		 * Create an alias for the first device that shows up.
267 		 */
268 		if (unit == 0) {
269 			(void)make_dev_alias_p(MAKEDEV_CHECKNAME,
270 			    &sc->as_devalias, sc->as_devnode, "agpgart");
271 		}
272 	} else {
273 		agp_free_res(dev);
274 	}
275 
276 	return error;
277 }
278 
279 void
280 agp_free_cdev(device_t dev)
281 {
282 	struct agp_softc *sc = device_get_softc(dev);
283 
284 	destroy_dev(sc->as_devnode);
285 	if (sc->as_devalias != NULL)
286 		destroy_dev(sc->as_devalias);
287 }
288 
289 void
290 agp_free_res(device_t dev)
291 {
292 	struct agp_softc *sc = device_get_softc(dev);
293 
294 	if (sc->as_aperture != NULL)
295 		bus_release_resource(dev, SYS_RES_MEMORY, sc->as_aperture_rid,
296 		    sc->as_aperture);
297 	mtx_destroy(&sc->as_lock);
298 }
299 
300 int
301 agp_generic_detach(device_t dev)
302 {
303 
304 	agp_free_cdev(dev);
305 	agp_free_res(dev);
306 	return 0;
307 }
308 
309 /**
310  * Default AGP aperture size detection which simply returns the size of
311  * the aperture's PCI resource.
312  */
313 u_int32_t
314 agp_generic_get_aperture(device_t dev)
315 {
316 	struct agp_softc *sc = device_get_softc(dev);
317 
318 	return rman_get_size(sc->as_aperture);
319 }
320 
321 /**
322  * Default AGP aperture size setting function, which simply doesn't allow
323  * changes to resource size.
324  */
325 int
326 agp_generic_set_aperture(device_t dev, u_int32_t aperture)
327 {
328 	u_int32_t current_aperture;
329 
330 	current_aperture = AGP_GET_APERTURE(dev);
331 	if (current_aperture != aperture)
332 		return EINVAL;
333 	else
334 		return 0;
335 }
336 
337 /*
338  * This does the enable logic for v3, with the same topology
339  * restrictions as in place for v2 -- one bus, one device on the bus.
340  */
341 static int
342 agp_v3_enable(device_t dev, device_t mdev, u_int32_t mode)
343 {
344 	u_int32_t tstatus, mstatus;
345 	u_int32_t command;
346 	int rq, sba, fw, rate, arqsz, cal;
347 
348 	tstatus = pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
349 	mstatus = pci_read_config(mdev, agp_find_caps(mdev) + AGP_STATUS, 4);
350 
351 	/* Set RQ to the min of mode, tstatus and mstatus */
352 	rq = AGP_MODE_GET_RQ(mode);
353 	if (AGP_MODE_GET_RQ(tstatus) < rq)
354 		rq = AGP_MODE_GET_RQ(tstatus);
355 	if (AGP_MODE_GET_RQ(mstatus) < rq)
356 		rq = AGP_MODE_GET_RQ(mstatus);
357 
358 	/*
359 	 * ARQSZ - Set the value to the maximum one.
360 	 * Don't allow the mode register to override values.
361 	 */
362 	arqsz = AGP_MODE_GET_ARQSZ(mode);
363 	if (AGP_MODE_GET_ARQSZ(tstatus) > rq)
364 		rq = AGP_MODE_GET_ARQSZ(tstatus);
365 	if (AGP_MODE_GET_ARQSZ(mstatus) > rq)
366 		rq = AGP_MODE_GET_ARQSZ(mstatus);
367 
368 	/* Calibration cycle - don't allow override by mode register */
369 	cal = AGP_MODE_GET_CAL(tstatus);
370 	if (AGP_MODE_GET_CAL(mstatus) < cal)
371 		cal = AGP_MODE_GET_CAL(mstatus);
372 
373 	/* SBA must be supported for AGP v3. */
374 	sba = 1;
375 
376 	/* Set FW if all three support it. */
377 	fw = (AGP_MODE_GET_FW(tstatus)
378 	       & AGP_MODE_GET_FW(mstatus)
379 	       & AGP_MODE_GET_FW(mode));
380 
381 	/* Figure out the max rate */
382 	rate = (AGP_MODE_GET_RATE(tstatus)
383 		& AGP_MODE_GET_RATE(mstatus)
384 		& AGP_MODE_GET_RATE(mode));
385 	if (rate & AGP_MODE_V3_RATE_8x)
386 		rate = AGP_MODE_V3_RATE_8x;
387 	else
388 		rate = AGP_MODE_V3_RATE_4x;
389 	if (bootverbose)
390 		device_printf(dev, "Setting AGP v3 mode %d\n", rate * 4);
391 
392 	pci_write_config(dev, agp_find_caps(dev) + AGP_COMMAND, 0, 4);
393 
394 	/* Construct the new mode word and tell the hardware */
395 	command = 0;
396 	command = AGP_MODE_SET_RQ(0, rq);
397 	command = AGP_MODE_SET_ARQSZ(command, arqsz);
398 	command = AGP_MODE_SET_CAL(command, cal);
399 	command = AGP_MODE_SET_SBA(command, sba);
400 	command = AGP_MODE_SET_FW(command, fw);
401 	command = AGP_MODE_SET_RATE(command, rate);
402 	command = AGP_MODE_SET_MODE_3(command, 1);
403 	command = AGP_MODE_SET_AGP(command, 1);
404 	pci_write_config(dev, agp_find_caps(dev) + AGP_COMMAND, command, 4);
405 	pci_write_config(mdev, agp_find_caps(mdev) + AGP_COMMAND, command, 4);
406 
407 	return 0;
408 }
409 
410 static int
411 agp_v2_enable(device_t dev, device_t mdev, u_int32_t mode)
412 {
413 	u_int32_t tstatus, mstatus;
414 	u_int32_t command;
415 	int rq, sba, fw, rate;
416 
417 	tstatus = pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
418 	mstatus = pci_read_config(mdev, agp_find_caps(mdev) + AGP_STATUS, 4);
419 
420 	/* Set RQ to the min of mode, tstatus and mstatus */
421 	rq = AGP_MODE_GET_RQ(mode);
422 	if (AGP_MODE_GET_RQ(tstatus) < rq)
423 		rq = AGP_MODE_GET_RQ(tstatus);
424 	if (AGP_MODE_GET_RQ(mstatus) < rq)
425 		rq = AGP_MODE_GET_RQ(mstatus);
426 
427 	/* Set SBA if all three can deal with SBA */
428 	sba = (AGP_MODE_GET_SBA(tstatus)
429 	       & AGP_MODE_GET_SBA(mstatus)
430 	       & AGP_MODE_GET_SBA(mode));
431 
432 	/* Similar for FW */
433 	fw = (AGP_MODE_GET_FW(tstatus)
434 	       & AGP_MODE_GET_FW(mstatus)
435 	       & AGP_MODE_GET_FW(mode));
436 
437 	/* Figure out the max rate */
438 	rate = (AGP_MODE_GET_RATE(tstatus)
439 		& AGP_MODE_GET_RATE(mstatus)
440 		& AGP_MODE_GET_RATE(mode));
441 	if (rate & AGP_MODE_V2_RATE_4x)
442 		rate = AGP_MODE_V2_RATE_4x;
443 	else if (rate & AGP_MODE_V2_RATE_2x)
444 		rate = AGP_MODE_V2_RATE_2x;
445 	else
446 		rate = AGP_MODE_V2_RATE_1x;
447 	if (bootverbose)
448 		device_printf(dev, "Setting AGP v2 mode %d\n", rate);
449 
450 	/* Construct the new mode word and tell the hardware */
451 	command = 0;
452 	command = AGP_MODE_SET_RQ(0, rq);
453 	command = AGP_MODE_SET_SBA(command, sba);
454 	command = AGP_MODE_SET_FW(command, fw);
455 	command = AGP_MODE_SET_RATE(command, rate);
456 	command = AGP_MODE_SET_AGP(command, 1);
457 	pci_write_config(dev, agp_find_caps(dev) + AGP_COMMAND, command, 4);
458 	pci_write_config(mdev, agp_find_caps(mdev) + AGP_COMMAND, command, 4);
459 
460 	return 0;
461 }
462 
463 int
464 agp_generic_enable(device_t dev, u_int32_t mode)
465 {
466 	device_t mdev = agp_find_display();
467 	u_int32_t tstatus, mstatus;
468 
469 	if (!mdev) {
470 		AGP_DPF("can't find display\n");
471 		return ENXIO;
472 	}
473 
474 	tstatus = pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
475 	mstatus = pci_read_config(mdev, agp_find_caps(mdev) + AGP_STATUS, 4);
476 
477 	/*
478 	 * Check display and bridge for AGP v3 support.  AGP v3 allows
479 	 * more variety in topology than v2, e.g. multiple AGP devices
480 	 * attached to one bridge, or multiple AGP bridges in one
481 	 * system.  This doesn't attempt to address those situations,
482 	 * but should work fine for a classic single AGP slot system
483 	 * with AGP v3.
484 	 */
485 	if (AGP_MODE_GET_MODE_3(mode) &&
486 	    AGP_MODE_GET_MODE_3(tstatus) &&
487 	    AGP_MODE_GET_MODE_3(mstatus))
488 		return (agp_v3_enable(dev, mdev, mode));
489 	else
490 		return (agp_v2_enable(dev, mdev, mode));
491 }
492 
493 struct agp_memory *
494 agp_generic_alloc_memory(device_t dev, int type, vm_size_t size)
495 {
496 	struct agp_softc *sc = device_get_softc(dev);
497 	struct agp_memory *mem;
498 
499 	if ((size & (AGP_PAGE_SIZE - 1)) != 0)
500 		return 0;
501 
502 	if (size > sc->as_maxmem - sc->as_allocated)
503 		return 0;
504 
505 	if (type != 0) {
506 		printf("agp_generic_alloc_memory: unsupported type %d\n",
507 		       type);
508 		return 0;
509 	}
510 
511 	mem = malloc(sizeof *mem, M_AGP, M_WAITOK);
512 	mem->am_id = sc->as_nextid++;
513 	mem->am_size = size;
514 	mem->am_type = 0;
515 	mem->am_obj = vm_object_allocate(OBJT_SWAP, atop(round_page(size)));
516 	mem->am_physical = 0;
517 	mem->am_offset = 0;
518 	mem->am_is_bound = 0;
519 	TAILQ_INSERT_TAIL(&sc->as_memory, mem, am_link);
520 	sc->as_allocated += size;
521 
522 	return mem;
523 }
524 
525 int
526 agp_generic_free_memory(device_t dev, struct agp_memory *mem)
527 {
528 	struct agp_softc *sc = device_get_softc(dev);
529 
530 	if (mem->am_is_bound)
531 		return EBUSY;
532 
533 	sc->as_allocated -= mem->am_size;
534 	TAILQ_REMOVE(&sc->as_memory, mem, am_link);
535 	vm_object_deallocate(mem->am_obj);
536 	free(mem, M_AGP);
537 	return 0;
538 }
539 
540 int
541 agp_generic_bind_memory(device_t dev, struct agp_memory *mem,
542 			vm_offset_t offset)
543 {
544 	struct agp_softc *sc = device_get_softc(dev);
545 	vm_offset_t i, j, k;
546 	vm_page_t m;
547 	int error;
548 
549 	/* Do some sanity checks first. */
550 	if ((offset & (AGP_PAGE_SIZE - 1)) != 0 ||
551 	    offset + mem->am_size > AGP_GET_APERTURE(dev)) {
552 		device_printf(dev, "binding memory at bad offset %#x\n",
553 		    (int)offset);
554 		return EINVAL;
555 	}
556 
557 	/*
558 	 * Allocate the pages early, before acquiring the lock,
559 	 * because vm_page_grab() may sleep and we can't hold a mutex
560 	 * while sleeping.
561 	 */
562 	VM_OBJECT_WLOCK(mem->am_obj);
563 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
564 		/*
565 		 * Find a page from the object and wire it
566 		 * down. This page will be mapped using one or more
567 		 * entries in the GATT (assuming that PAGE_SIZE >=
568 		 * AGP_PAGE_SIZE. If this is the first call to bind,
569 		 * the pages will be allocated and zeroed.
570 		 */
571 		m = vm_page_grab(mem->am_obj, OFF_TO_IDX(i),
572 		    VM_ALLOC_WIRED | VM_ALLOC_ZERO);
573 		AGP_DPF("found page pa=%#jx\n", (uintmax_t)VM_PAGE_TO_PHYS(m));
574 	}
575 	VM_OBJECT_WUNLOCK(mem->am_obj);
576 
577 	mtx_lock(&sc->as_lock);
578 
579 	if (mem->am_is_bound) {
580 		device_printf(dev, "memory already bound\n");
581 		error = EINVAL;
582 		VM_OBJECT_WLOCK(mem->am_obj);
583 		i = 0;
584 		goto bad;
585 	}
586 
587 	/*
588 	 * Bind the individual pages and flush the chipset's
589 	 * TLB.
590 	 */
591 	VM_OBJECT_WLOCK(mem->am_obj);
592 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
593 		m = vm_page_lookup(mem->am_obj, OFF_TO_IDX(i));
594 
595 		/*
596 		 * Install entries in the GATT, making sure that if
597 		 * AGP_PAGE_SIZE < PAGE_SIZE and mem->am_size is not
598 		 * aligned to PAGE_SIZE, we don't modify too many GATT
599 		 * entries.
600 		 */
601 		for (j = 0; j < PAGE_SIZE && i + j < mem->am_size;
602 		     j += AGP_PAGE_SIZE) {
603 			vm_offset_t pa = VM_PAGE_TO_PHYS(m) + j;
604 			AGP_DPF("binding offset %#jx to pa %#jx\n",
605 				(uintmax_t)offset + i + j, (uintmax_t)pa);
606 			error = AGP_BIND_PAGE(dev, offset + i + j, pa);
607 			if (error) {
608 				/*
609 				 * Bail out. Reverse all the mappings
610 				 * and unwire the pages.
611 				 */
612 				for (k = 0; k < i + j; k += AGP_PAGE_SIZE)
613 					AGP_UNBIND_PAGE(dev, offset + k);
614 				goto bad;
615 			}
616 		}
617 		vm_page_xunbusy(m);
618 	}
619 	VM_OBJECT_WUNLOCK(mem->am_obj);
620 
621 	/*
622 	 * Make sure the chipset gets the new mappings.
623 	 */
624 	AGP_FLUSH_TLB(dev);
625 
626 	mem->am_offset = offset;
627 	mem->am_is_bound = 1;
628 
629 	mtx_unlock(&sc->as_lock);
630 
631 	return 0;
632 bad:
633 	mtx_unlock(&sc->as_lock);
634 	VM_OBJECT_ASSERT_WLOCKED(mem->am_obj);
635 	for (k = 0; k < mem->am_size; k += PAGE_SIZE) {
636 		m = vm_page_lookup(mem->am_obj, OFF_TO_IDX(k));
637 		if (k >= i)
638 			vm_page_xunbusy(m);
639 		vm_page_unwire(m, PQ_INACTIVE);
640 	}
641 	VM_OBJECT_WUNLOCK(mem->am_obj);
642 
643 	return error;
644 }
645 
646 int
647 agp_generic_unbind_memory(device_t dev, struct agp_memory *mem)
648 {
649 	struct agp_softc *sc = device_get_softc(dev);
650 	vm_page_t m;
651 	int i;
652 
653 	mtx_lock(&sc->as_lock);
654 
655 	if (!mem->am_is_bound) {
656 		device_printf(dev, "memory is not bound\n");
657 		mtx_unlock(&sc->as_lock);
658 		return EINVAL;
659 	}
660 
661 	/*
662 	 * Unbind the individual pages and flush the chipset's
663 	 * TLB. Unwire the pages so they can be swapped.
664 	 */
665 	for (i = 0; i < mem->am_size; i += AGP_PAGE_SIZE)
666 		AGP_UNBIND_PAGE(dev, mem->am_offset + i);
667 
668 	AGP_FLUSH_TLB(dev);
669 
670 	VM_OBJECT_WLOCK(mem->am_obj);
671 	for (i = 0; i < mem->am_size; i += PAGE_SIZE) {
672 		m = vm_page_lookup(mem->am_obj, atop(i));
673 		vm_page_unwire(m, PQ_INACTIVE);
674 	}
675 	VM_OBJECT_WUNLOCK(mem->am_obj);
676 
677 	mem->am_offset = 0;
678 	mem->am_is_bound = 0;
679 
680 	mtx_unlock(&sc->as_lock);
681 
682 	return 0;
683 }
684 
685 /* Helper functions for implementing user/kernel api */
686 
687 static int
688 agp_acquire_helper(device_t dev, enum agp_acquire_state state)
689 {
690 	struct agp_softc *sc = device_get_softc(dev);
691 
692 	if (sc->as_state != AGP_ACQUIRE_FREE)
693 		return EBUSY;
694 	sc->as_state = state;
695 
696 	return 0;
697 }
698 
699 static int
700 agp_release_helper(device_t dev, enum agp_acquire_state state)
701 {
702 	struct agp_softc *sc = device_get_softc(dev);
703 
704 	if (sc->as_state == AGP_ACQUIRE_FREE)
705 		return 0;
706 
707 	if (sc->as_state != state)
708 		return EBUSY;
709 
710 	sc->as_state = AGP_ACQUIRE_FREE;
711 	return 0;
712 }
713 
714 static struct agp_memory *
715 agp_find_memory(device_t dev, int id)
716 {
717 	struct agp_softc *sc = device_get_softc(dev);
718 	struct agp_memory *mem;
719 
720 	AGP_DPF("searching for memory block %d\n", id);
721 	TAILQ_FOREACH(mem, &sc->as_memory, am_link) {
722 		AGP_DPF("considering memory block %d\n", mem->am_id);
723 		if (mem->am_id == id)
724 			return mem;
725 	}
726 	return 0;
727 }
728 
729 /* Implementation of the userland ioctl api */
730 
731 static int
732 agp_info_user(device_t dev, agp_info *info)
733 {
734 	struct agp_softc *sc = device_get_softc(dev);
735 
736 	bzero(info, sizeof *info);
737 	info->bridge_id = pci_get_devid(dev);
738 	info->agp_mode =
739 	    pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
740 	if (sc->as_aperture)
741 		info->aper_base = rman_get_start(sc->as_aperture);
742 	else
743 		info->aper_base = 0;
744 	info->aper_size = AGP_GET_APERTURE(dev) >> 20;
745 	info->pg_total = info->pg_system = sc->as_maxmem >> AGP_PAGE_SHIFT;
746 	info->pg_used = sc->as_allocated >> AGP_PAGE_SHIFT;
747 
748 	return 0;
749 }
750 
751 static int
752 agp_setup_user(device_t dev, agp_setup *setup)
753 {
754 	return AGP_ENABLE(dev, setup->agp_mode);
755 }
756 
757 static int
758 agp_allocate_user(device_t dev, agp_allocate *alloc)
759 {
760 	struct agp_memory *mem;
761 
762 	mem = AGP_ALLOC_MEMORY(dev,
763 			       alloc->type,
764 			       alloc->pg_count << AGP_PAGE_SHIFT);
765 	if (mem) {
766 		alloc->key = mem->am_id;
767 		alloc->physical = mem->am_physical;
768 		return 0;
769 	} else {
770 		return ENOMEM;
771 	}
772 }
773 
774 static int
775 agp_deallocate_user(device_t dev, int id)
776 {
777 	struct agp_memory *mem = agp_find_memory(dev, id);
778 
779 	if (mem) {
780 		AGP_FREE_MEMORY(dev, mem);
781 		return 0;
782 	} else {
783 		return ENOENT;
784 	}
785 }
786 
787 static int
788 agp_bind_user(device_t dev, agp_bind *bind)
789 {
790 	struct agp_memory *mem = agp_find_memory(dev, bind->key);
791 
792 	if (!mem)
793 		return ENOENT;
794 
795 	return AGP_BIND_MEMORY(dev, mem, bind->pg_start << AGP_PAGE_SHIFT);
796 }
797 
798 static int
799 agp_unbind_user(device_t dev, agp_unbind *unbind)
800 {
801 	struct agp_memory *mem = agp_find_memory(dev, unbind->key);
802 
803 	if (!mem)
804 		return ENOENT;
805 
806 	return AGP_UNBIND_MEMORY(dev, mem);
807 }
808 
809 static int
810 agp_chipset_flush(device_t dev)
811 {
812 
813 	return (AGP_CHIPSET_FLUSH(dev));
814 }
815 
816 static int
817 agp_open(struct cdev *kdev, int oflags, int devtype, struct thread *td)
818 {
819 	device_t dev = kdev->si_drv1;
820 	struct agp_softc *sc = device_get_softc(dev);
821 
822 	if (!sc->as_isopen) {
823 		sc->as_isopen = 1;
824 		device_busy(dev);
825 	}
826 
827 	return 0;
828 }
829 
830 static int
831 agp_close(struct cdev *kdev, int fflag, int devtype, struct thread *td)
832 {
833 	device_t dev = kdev->si_drv1;
834 	struct agp_softc *sc = device_get_softc(dev);
835 	struct agp_memory *mem;
836 
837 	/*
838 	 * Clear the GATT and force release on last close
839 	 */
840 	while ((mem = TAILQ_FIRST(&sc->as_memory)) != NULL) {
841 		if (mem->am_is_bound)
842 			AGP_UNBIND_MEMORY(dev, mem);
843 		AGP_FREE_MEMORY(dev, mem);
844 	}
845 	if (sc->as_state == AGP_ACQUIRE_USER)
846 		agp_release_helper(dev, AGP_ACQUIRE_USER);
847 	sc->as_isopen = 0;
848 	device_unbusy(dev);
849 
850 	return 0;
851 }
852 
853 static int
854 agp_ioctl(struct cdev *kdev, u_long cmd, caddr_t data, int fflag, struct thread *td)
855 {
856 	device_t dev = kdev->si_drv1;
857 
858 	switch (cmd) {
859 	case AGPIOC_INFO:
860 		return agp_info_user(dev, (agp_info *) data);
861 
862 	case AGPIOC_ACQUIRE:
863 		return agp_acquire_helper(dev, AGP_ACQUIRE_USER);
864 
865 	case AGPIOC_RELEASE:
866 		return agp_release_helper(dev, AGP_ACQUIRE_USER);
867 
868 	case AGPIOC_SETUP:
869 		return agp_setup_user(dev, (agp_setup *)data);
870 
871 	case AGPIOC_ALLOCATE:
872 		return agp_allocate_user(dev, (agp_allocate *)data);
873 
874 	case AGPIOC_DEALLOCATE:
875 		return agp_deallocate_user(dev, *(int *) data);
876 
877 	case AGPIOC_BIND:
878 		return agp_bind_user(dev, (agp_bind *)data);
879 
880 	case AGPIOC_UNBIND:
881 		return agp_unbind_user(dev, (agp_unbind *)data);
882 
883 	case AGPIOC_CHIPSET_FLUSH:
884 		return agp_chipset_flush(dev);
885 	}
886 
887 	return EINVAL;
888 }
889 
890 static int
891 agp_mmap(struct cdev *kdev, vm_ooffset_t offset, vm_paddr_t *paddr,
892     int prot, vm_memattr_t *memattr)
893 {
894 	device_t dev = kdev->si_drv1;
895 	struct agp_softc *sc = device_get_softc(dev);
896 
897 	if (offset > AGP_GET_APERTURE(dev))
898 		return -1;
899 	if (sc->as_aperture == NULL)
900 		return -1;
901 	*paddr = rman_get_start(sc->as_aperture) + offset;
902 	return 0;
903 }
904 
905 /* Implementation of the kernel api */
906 
907 device_t
908 agp_find_device(void)
909 {
910 	device_t *children, child;
911 	int i, count;
912 
913 	if (!agp_devclass)
914 		return NULL;
915 	if (devclass_get_devices(agp_devclass, &children, &count) != 0)
916 		return NULL;
917 	child = NULL;
918 	for (i = 0; i < count; i++) {
919 		if (device_is_attached(children[i])) {
920 			child = children[i];
921 			break;
922 		}
923 	}
924 	free(children, M_TEMP);
925 	return child;
926 }
927 
928 enum agp_acquire_state
929 agp_state(device_t dev)
930 {
931 	struct agp_softc *sc = device_get_softc(dev);
932 	return sc->as_state;
933 }
934 
935 void
936 agp_get_info(device_t dev, struct agp_info *info)
937 {
938 	struct agp_softc *sc = device_get_softc(dev);
939 
940 	info->ai_mode =
941 		pci_read_config(dev, agp_find_caps(dev) + AGP_STATUS, 4);
942 	if (sc->as_aperture != NULL)
943 		info->ai_aperture_base = rman_get_start(sc->as_aperture);
944 	else
945 		info->ai_aperture_base = 0;
946 	info->ai_aperture_size = AGP_GET_APERTURE(dev);
947 	info->ai_memory_allowed = sc->as_maxmem;
948 	info->ai_memory_used = sc->as_allocated;
949 }
950 
951 int
952 agp_acquire(device_t dev)
953 {
954 	return agp_acquire_helper(dev, AGP_ACQUIRE_KERNEL);
955 }
956 
957 int
958 agp_release(device_t dev)
959 {
960 	return agp_release_helper(dev, AGP_ACQUIRE_KERNEL);
961 }
962 
963 int
964 agp_enable(device_t dev, u_int32_t mode)
965 {
966 	return AGP_ENABLE(dev, mode);
967 }
968 
969 void *agp_alloc_memory(device_t dev, int type, vm_size_t bytes)
970 {
971 	return  (void *) AGP_ALLOC_MEMORY(dev, type, bytes);
972 }
973 
974 void agp_free_memory(device_t dev, void *handle)
975 {
976 	struct agp_memory *mem = (struct agp_memory *) handle;
977 	AGP_FREE_MEMORY(dev, mem);
978 }
979 
980 int agp_bind_memory(device_t dev, void *handle, vm_offset_t offset)
981 {
982 	struct agp_memory *mem = (struct agp_memory *) handle;
983 	return AGP_BIND_MEMORY(dev, mem, offset);
984 }
985 
986 int agp_unbind_memory(device_t dev, void *handle)
987 {
988 	struct agp_memory *mem = (struct agp_memory *) handle;
989 	return AGP_UNBIND_MEMORY(dev, mem);
990 }
991 
992 void agp_memory_info(device_t dev, void *handle, struct
993 		     agp_memory_info *mi)
994 {
995 	struct agp_memory *mem = (struct agp_memory *) handle;
996 
997 	mi->ami_size = mem->am_size;
998 	mi->ami_physical = mem->am_physical;
999 	mi->ami_offset = mem->am_offset;
1000 	mi->ami_is_bound = mem->am_is_bound;
1001 }
1002 
1003 int
1004 agp_bind_pages(device_t dev, vm_page_t *pages, vm_size_t size,
1005     vm_offset_t offset)
1006 {
1007 	struct agp_softc *sc;
1008 	vm_offset_t i, j, k, pa;
1009 	vm_page_t m;
1010 	int error;
1011 
1012 	if ((size & (AGP_PAGE_SIZE - 1)) != 0 ||
1013 	    (offset & (AGP_PAGE_SIZE - 1)) != 0)
1014 		return (EINVAL);
1015 
1016 	sc = device_get_softc(dev);
1017 
1018 	mtx_lock(&sc->as_lock);
1019 	for (i = 0; i < size; i += PAGE_SIZE) {
1020 		m = pages[OFF_TO_IDX(i)];
1021 		KASSERT(vm_page_wired(m),
1022 		    ("agp_bind_pages: page %p hasn't been wired", m));
1023 
1024 		/*
1025 		 * Install entries in the GATT, making sure that if
1026 		 * AGP_PAGE_SIZE < PAGE_SIZE and size is not
1027 		 * aligned to PAGE_SIZE, we don't modify too many GATT
1028 		 * entries.
1029 		 */
1030 		for (j = 0; j < PAGE_SIZE && i + j < size; j += AGP_PAGE_SIZE) {
1031 			pa = VM_PAGE_TO_PHYS(m) + j;
1032 			AGP_DPF("binding offset %#jx to pa %#jx\n",
1033 				(uintmax_t)offset + i + j, (uintmax_t)pa);
1034 			error = AGP_BIND_PAGE(dev, offset + i + j, pa);
1035 			if (error) {
1036 				/*
1037 				 * Bail out. Reverse all the mappings.
1038 				 */
1039 				for (k = 0; k < i + j; k += AGP_PAGE_SIZE)
1040 					AGP_UNBIND_PAGE(dev, offset + k);
1041 
1042 				mtx_unlock(&sc->as_lock);
1043 				return (error);
1044 			}
1045 		}
1046 	}
1047 
1048 	AGP_FLUSH_TLB(dev);
1049 
1050 	mtx_unlock(&sc->as_lock);
1051 	return (0);
1052 }
1053 
1054 int
1055 agp_unbind_pages(device_t dev, vm_size_t size, vm_offset_t offset)
1056 {
1057 	struct agp_softc *sc;
1058 	vm_offset_t i;
1059 
1060 	if ((size & (AGP_PAGE_SIZE - 1)) != 0 ||
1061 	    (offset & (AGP_PAGE_SIZE - 1)) != 0)
1062 		return (EINVAL);
1063 
1064 	sc = device_get_softc(dev);
1065 
1066 	mtx_lock(&sc->as_lock);
1067 	for (i = 0; i < size; i += AGP_PAGE_SIZE)
1068 		AGP_UNBIND_PAGE(dev, offset + i);
1069 
1070 	AGP_FLUSH_TLB(dev);
1071 
1072 	mtx_unlock(&sc->as_lock);
1073 	return (0);
1074 }
1075