xref: /netbsd-src/sys/dev/pci/agp_i810.c (revision d710132b4b8ce7f7cccaaf660cb16aa16b4077a0) 
1 /*	$NetBSD: agp_i810.c,v 1.16 2003/03/24 09:12:55 drochner Exp $	*/
2 
3 /*-
4  * Copyright (c) 2000 Doug Rabson
5  * Copyright (c) 2000 Ruslan Ermilov
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	$FreeBSD: src/sys/pci/agp_i810.c,v 1.4 2001/07/05 21:28:47 jhb Exp $
30  */
31 
32 #include <sys/cdefs.h>
33 __KERNEL_RCSID(0, "$NetBSD: agp_i810.c,v 1.16 2003/03/24 09:12:55 drochner Exp $");
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/malloc.h>
38 #include <sys/kernel.h>
39 #include <sys/lock.h>
40 #include <sys/proc.h>
41 #include <sys/device.h>
42 #include <sys/conf.h>
43 
44 #include <uvm/uvm_extern.h>
45 
46 #include <dev/pci/pcivar.h>
47 #include <dev/pci/pcireg.h>
48 #include <dev/pci/pcidevs.h>
49 #include <dev/pci/agpvar.h>
50 #include <dev/pci/agpreg.h>
51 
52 #include <sys/agpio.h>
53 
54 #include <machine/bus.h>
55 
56 #define READ1(off)	bus_space_read_1(isc->bst, isc->bsh, off)
57 #define READ4(off)	bus_space_read_4(isc->bst, isc->bsh, off)
58 #define WRITE4(off,v)	bus_space_write_4(isc->bst, isc->bsh, off, v)
59 
60 #define CHIP_I810 0	/* i810/i815 */
61 #define CHIP_I830 1	/* i830/i845 */
62 
63 struct agp_i810_softc {
64 	u_int32_t initial_aperture;	/* aperture size at startup */
65 	struct agp_gatt *gatt;
66 	int chiptype;			/* i810-like or i830 */
67 	u_int32_t dcache_size;		/* i810 only */
68 	u_int32_t stolen;		/* number of i830/845 gtt entries
69 					   for stolen memory */
70 	bus_space_tag_t bst;		/* bus_space tag */
71 	bus_space_handle_t bsh;		/* bus_space handle */
72 	struct pci_attach_args vga_pa;
73 };
74 
75 static u_int32_t agp_i810_get_aperture(struct agp_softc *);
76 static int agp_i810_set_aperture(struct agp_softc *, u_int32_t);
77 static int agp_i810_bind_page(struct agp_softc *, off_t, bus_addr_t);
78 static int agp_i810_unbind_page(struct agp_softc *, off_t);
79 static void agp_i810_flush_tlb(struct agp_softc *);
80 static int agp_i810_enable(struct agp_softc *, u_int32_t mode);
81 static struct agp_memory *agp_i810_alloc_memory(struct agp_softc *, int,
82 						vsize_t);
83 static int agp_i810_free_memory(struct agp_softc *, struct agp_memory *);
84 static int agp_i810_bind_memory(struct agp_softc *, struct agp_memory *, off_t);
85 static int agp_i810_unbind_memory(struct agp_softc *, struct agp_memory *);
86 
87 struct agp_methods agp_i810_methods = {
88 	agp_i810_get_aperture,
89 	agp_i810_set_aperture,
90 	agp_i810_bind_page,
91 	agp_i810_unbind_page,
92 	agp_i810_flush_tlb,
93 	agp_i810_enable,
94 	agp_i810_alloc_memory,
95 	agp_i810_free_memory,
96 	agp_i810_bind_memory,
97 	agp_i810_unbind_memory,
98 };
99 
100 /* XXXthorpej -- duplicated code (see arch/i386/pci/pchb.c) */
101 static int
102 agp_i810_vgamatch(struct pci_attach_args *pa)
103 {
104 
105 	if (PCI_CLASS(pa->pa_class) != PCI_CLASS_DISPLAY ||
106 	    PCI_SUBCLASS(pa->pa_class) != PCI_SUBCLASS_DISPLAY_VGA)
107 		return (0);
108 
109 	switch (PCI_PRODUCT(pa->pa_id)) {
110 	case PCI_PRODUCT_INTEL_82810_GC:
111 	case PCI_PRODUCT_INTEL_82810_DC100_GC:
112 	case PCI_PRODUCT_INTEL_82810E_GC:
113 	case PCI_PRODUCT_INTEL_82815_FULL_GRAPH:
114 	case PCI_PRODUCT_INTEL_82830MP_IV:
115 	case PCI_PRODUCT_INTEL_82845G_IGD:
116 		return (1);
117 	}
118 
119 	return (0);
120 }
121 
122 int
123 agp_i810_attach(struct device *parent, struct device *self, void *aux)
124 {
125 	struct agp_softc *sc = (void *)self;
126 	struct agp_i810_softc *isc;
127 	struct agp_gatt *gatt;
128 	int error;
129 
130 	isc = malloc(sizeof *isc, M_AGP, M_NOWAIT|M_ZERO);
131 	if (isc == NULL) {
132 		aprint_error(": can't allocate chipset-specific softc\n");
133 		return ENOMEM;
134 	}
135 	sc->as_chipc = isc;
136 	sc->as_methods = &agp_i810_methods;
137 
138 	if (pci_find_device(&isc->vga_pa, agp_i810_vgamatch) == 0) {
139 		aprint_error(": can't find internal VGA device config space\n");
140 		free(isc, M_AGP);
141 		return ENOENT;
142 	}
143 
144 	/* XXXfvdl */
145 	sc->as_dmat = isc->vga_pa.pa_dmat;
146 
147 	error = agp_map_aperture(&isc->vga_pa, sc);
148 	if (error != 0) {
149 		aprint_error(": can't map aperture\n");
150 		free(isc, M_AGP);
151 		return error;
152 	}
153 
154 	switch (PCI_PRODUCT(isc->vga_pa.pa_id)) {
155 	case PCI_PRODUCT_INTEL_82810_GC:
156 	case PCI_PRODUCT_INTEL_82810_DC100_GC:
157 	case PCI_PRODUCT_INTEL_82810E_GC:
158 	case PCI_PRODUCT_INTEL_82815_FULL_GRAPH:
159 		isc->chiptype = CHIP_I810;
160 		break;
161 	case PCI_PRODUCT_INTEL_82830MP_IV:
162 	case PCI_PRODUCT_INTEL_82845G_IGD:
163 		isc->chiptype = CHIP_I830;
164 		break;
165 	}
166 
167 	error = pci_mapreg_map(&isc->vga_pa, AGP_I810_MMADR,
168 	    PCI_MAPREG_TYPE_MEM, 0, &isc->bst, &isc->bsh, NULL, NULL);
169 	if (error != 0) {
170 		aprint_error(": can't map mmadr registers\n");
171 		return error;
172 	}
173 
174 	isc->initial_aperture = AGP_GET_APERTURE(sc);
175 
176 	gatt = malloc(sizeof(struct agp_gatt), M_AGP, M_NOWAIT);
177 	if (!gatt) {
178  		agp_generic_detach(sc);
179  		return ENOMEM;
180 	}
181 	isc->gatt = gatt;
182 
183 	gatt->ag_entries = AGP_GET_APERTURE(sc) >> AGP_PAGE_SHIFT;
184 
185 	if (isc->chiptype == CHIP_I810) {
186 		int dummyseg;
187 		/* Some i810s have on-chip memory called dcache */
188 		if (READ1(AGP_I810_DRT) & AGP_I810_DRT_POPULATED)
189 			isc->dcache_size = 4 * 1024 * 1024;
190 		else
191 			isc->dcache_size = 0;
192 
193 		/* According to the specs the gatt on the i810 must be 64k */
194 		if (agp_alloc_dmamem(sc->as_dmat, 64 * 1024,
195 		    0, &gatt->ag_dmamap, (caddr_t *)&gatt->ag_virtual,
196 		    &gatt->ag_physical, &gatt->ag_dmaseg, 1, &dummyseg) != 0) {
197 			free(gatt, M_AGP);
198 			agp_generic_detach(sc);
199 			return ENOMEM;
200 		}
201 
202 		gatt->ag_size = gatt->ag_entries * sizeof(u_int32_t);
203 		memset(gatt->ag_virtual, 0, gatt->ag_size);
204 
205 		agp_flush_cache();
206 		/* Install the GATT. */
207 		WRITE4(AGP_I810_PGTBL_CTL, gatt->ag_physical | 1);
208 	} else {
209 		/* The i830 automatically initializes the 128k gatt on boot. */
210 		pcireg_t reg;
211 		u_int32_t pgtblctl;
212 		u_int16_t gcc1;
213 
214 		reg = pci_conf_read(sc->as_pc, sc->as_tag, AGP_I830_GCC0);
215 		gcc1 = (u_int16_t)(reg >> 16);
216 		switch (gcc1 & AGP_I830_GCC1_GMS) {
217 		case AGP_I830_GCC1_GMS_STOLEN_512:
218 			isc->stolen = (512 - 132) * 1024 / 4096;
219 			break;
220 		case AGP_I830_GCC1_GMS_STOLEN_1024:
221 			isc->stolen = (1024 - 132) * 1024 / 4096;
222 			break;
223 		case AGP_I830_GCC1_GMS_STOLEN_8192:
224 			isc->stolen = (8192 - 132) * 1024 / 4096;
225 			break;
226 		default:
227 			isc->stolen = 0;
228 			aprint_error(
229 			    ": unknown memory configuration, disabling\n");
230 			agp_generic_detach(sc);
231 			return EINVAL;
232 		}
233 		if (isc->stolen > 0) {
234 			aprint_error(": detected %dk stolen memory\n",
235 			    isc->stolen * 4);
236 		}
237 		aprint_error("%s: aperture size is %dM\n", sc->as_dev.dv_xname,
238 		       isc->initial_aperture / 1024 / 1024);
239 
240 		/* GATT address is already in there, make sure it's enabled */
241 		pgtblctl = READ4(AGP_I810_PGTBL_CTL);
242 		pgtblctl |= 1;
243 		WRITE4(AGP_I810_PGTBL_CTL, pgtblctl);
244 
245 		gatt->ag_physical = pgtblctl & ~1;
246 	}
247 
248 	/*
249 	 * Make sure the chipset can see everything.
250 	 */
251 	agp_flush_cache();
252 
253 	return 0;
254 }
255 
256 #if 0
257 static int
258 agp_i810_detach(struct agp_softc *sc)
259 {
260 	int error;
261 	struct agp_i810_softc *isc = sc->as_chipc;
262 
263 	error = agp_generic_detach(sc);
264 	if (error)
265 		return error;
266 
267 	/* Clear the GATT base. */
268 	if (sc->chiptype == CHIP_I810) {
269 		WRITE4(AGP_I810_PGTBL_CTL, 0);
270 	} else {
271 		unsigned int pgtblctl;
272 		pgtblctl = READ4(AGP_I810_PGTBL_CTL);
273 		pgtblctl &= ~1;
274 		WRITE4(AGP_I810_PGTBL_CTL, pgtblctl);
275 	}
276 
277 	/* Put the aperture back the way it started. */
278 	AGP_SET_APERTURE(sc, isc->initial_aperture);
279 
280 	if (sc->chiptype == CHIP_I810) {
281 		agp_free_dmamem(sc->as_dmat, gatt->ag_size, gatt->ag_dmamap,
282 		    (caddr_t)gatt->ag_virtual, &gatt->ag_dmaseg, 1);
283 	}
284 	free(sc->gatt, M_AGP);
285 
286 	return 0;
287 }
288 #endif
289 
290 static u_int32_t
291 agp_i810_get_aperture(struct agp_softc *sc)
292 {
293 	struct agp_i810_softc *isc = sc->as_chipc;
294 	pcireg_t reg;
295 
296 	if (isc->chiptype == CHIP_I810) {
297 		u_int16_t miscc;
298 
299 		reg = pci_conf_read(sc->as_pc, sc->as_tag, AGP_I810_SMRAM);
300 		miscc = (u_int16_t)(reg >> 16);
301 		if ((miscc & AGP_I810_MISCC_WINSIZE) ==
302 		    AGP_I810_MISCC_WINSIZE_32)
303 			return 32 * 1024 * 1024;
304 		else
305 			return 64 * 1024 * 1024;
306 	} else {		/* I830 */
307 		u_int16_t gcc1;
308 
309 		reg = pci_conf_read(sc->as_pc, sc->as_tag, AGP_I830_GCC0);
310 		gcc1 = (u_int16_t)(reg >> 16);
311 		if ((gcc1 & AGP_I830_GCC1_GMASIZE) == AGP_I830_GCC1_GMASIZE_64)
312 			return 64 * 1024 * 1024;
313 		else
314 			return 128 * 1024 * 1024;
315 	}
316 }
317 
318 static int
319 agp_i810_set_aperture(struct agp_softc *sc, u_int32_t aperture)
320 {
321 	struct agp_i810_softc *isc = sc->as_chipc;
322 	pcireg_t reg;
323 
324 	if (isc->chiptype == CHIP_I810) {
325 		u_int16_t miscc;
326 
327 		/*
328 		 * Double check for sanity.
329 		 */
330 		if (aperture != (32 * 1024 * 1024) &&
331 		    aperture != (64 * 1024 * 1024)) {
332 			printf("%s: bad aperture size %d\n",
333 			    sc->as_dev.dv_xname, aperture);
334 			return EINVAL;
335 		}
336 
337 		reg = pci_conf_read(sc->as_pc, sc->as_tag, AGP_I810_SMRAM);
338 		miscc = (u_int16_t)(reg >> 16);
339 		miscc &= ~AGP_I810_MISCC_WINSIZE;
340 		if (aperture == 32 * 1024 * 1024)
341 			miscc |= AGP_I810_MISCC_WINSIZE_32;
342 		else
343 			miscc |= AGP_I810_MISCC_WINSIZE_64;
344 
345 		reg &= 0x0000ffff;
346 		reg |= ((pcireg_t)miscc) << 16;
347 		pci_conf_write(sc->as_pc, sc->as_tag, AGP_I810_SMRAM, reg);
348 	} else {		/* I830 */
349 		u_int16_t gcc1;
350 
351 		if (aperture != (64 * 1024 * 1024) &&
352 		    aperture != (128 * 1024 * 1024)) {
353 			printf("%s: bad aperture size %d\n",
354 			    sc->as_dev.dv_xname, aperture);
355 			return EINVAL;
356 		}
357 		reg = pci_conf_read(sc->as_pc, sc->as_tag, AGP_I830_GCC0);
358 		gcc1 = (u_int16_t)(reg >> 16);
359 		gcc1 &= ~AGP_I830_GCC1_GMASIZE;
360 		if (aperture == 64 * 1024 * 1024)
361 			gcc1 |= AGP_I830_GCC1_GMASIZE_64;
362 		else
363 			gcc1 |= AGP_I830_GCC1_GMASIZE_128;
364 
365 		reg &= 0x0000ffff;
366 		reg |= ((pcireg_t)gcc1) << 16;
367 		pci_conf_write(sc->as_pc, sc->as_tag, AGP_I830_GCC0, reg);
368 	}
369 
370 	return 0;
371 }
372 
373 static int
374 agp_i810_bind_page(struct agp_softc *sc, off_t offset, bus_addr_t physical)
375 {
376 	struct agp_i810_softc *isc = sc->as_chipc;
377 
378 	if (offset < 0 || offset >= (isc->gatt->ag_entries << AGP_PAGE_SHIFT)) {
379 #ifdef DEBUG
380 		printf("%s: failed: offset 0x%08x, shift %d, entries %d\n",
381 		    sc->as_dev.dv_xname, (int)offset, AGP_PAGE_SHIFT,
382 		    isc->gatt->ag_entries);
383 #endif
384 		return EINVAL;
385 	}
386 
387 	if (isc->chiptype == CHIP_I810) {
388 		if ((offset >> AGP_PAGE_SHIFT) < isc->stolen) {
389 #ifdef DEBUG
390 			printf("%s: trying to bind into stolen memory",
391 			    sc->as_dev.dv_xname);
392 #endif
393 			return EINVAL;
394 		}
395 	}
396 
397 	WRITE4(AGP_I810_GTT + (u_int32_t)(offset >> AGP_PAGE_SHIFT) * 4,
398 	    physical | 1);
399 	return 0;
400 }
401 
402 static int
403 agp_i810_unbind_page(struct agp_softc *sc, off_t offset)
404 {
405 	struct agp_i810_softc *isc = sc->as_chipc;
406 
407 	if (offset < 0 || offset >= (isc->gatt->ag_entries << AGP_PAGE_SHIFT))
408 		return EINVAL;
409 
410 	if (isc->chiptype == CHIP_I830 ) {
411 		if ((offset >> AGP_PAGE_SHIFT) < isc->stolen) {
412 #ifdef DEBUG
413 			printf("%s: trying to unbind from stolen memory",
414 			    sc->as_dev.dv_xname);
415 #endif
416 			return EINVAL;
417 		}
418 	}
419 
420 	WRITE4(AGP_I810_GTT + (u_int32_t)(offset >> AGP_PAGE_SHIFT) * 4, 0);
421 	return 0;
422 }
423 
424 /*
425  * Writing via memory mapped registers already flushes all TLBs.
426  */
427 static void
428 agp_i810_flush_tlb(struct agp_softc *sc)
429 {
430 }
431 
432 static int
433 agp_i810_enable(struct agp_softc *sc, u_int32_t mode)
434 {
435 
436 	return 0;
437 }
438 
439 static struct agp_memory *
440 agp_i810_alloc_memory(struct agp_softc *sc, int type, vsize_t size)
441 {
442 	struct agp_i810_softc *isc = sc->as_chipc;
443 	struct agp_memory *mem;
444 
445 	if ((size & (AGP_PAGE_SIZE - 1)) != 0)
446 		return 0;
447 
448 	if (sc->as_allocated + size > sc->as_maxmem)
449 		return 0;
450 
451 	if (type == 1) {
452 		/*
453 		 * Mapping local DRAM into GATT.
454 		 */
455 		if (isc->chiptype == CHIP_I830 )
456 			return 0;
457 		if (size != isc->dcache_size)
458 			return 0;
459 	} else if (type == 2) {
460 		/*
461 		 * Bogus mapping of a single page for the hardware cursor.
462 		 */
463 		if (size != AGP_PAGE_SIZE)
464 			return 0;
465 	}
466 
467 	mem = malloc(sizeof *mem, M_AGP, M_WAITOK|M_ZERO);
468 	if (mem == NULL)
469 		return NULL;
470 	mem->am_id = sc->as_nextid++;
471 	mem->am_size = size;
472 	mem->am_type = type;
473 
474 	if (type == 2) {
475 		/*
476 		 * Allocate and wire down the page now so that we can
477 		 * get its physical address.
478 		 */
479 		mem->am_dmaseg = malloc(sizeof *mem->am_dmaseg, M_AGP,
480 		    M_WAITOK);
481 		if (mem->am_dmaseg == NULL) {
482 			free(mem, M_AGP);
483 			return NULL;
484 		}
485 		if (agp_alloc_dmamem(sc->as_dmat, size, 0,
486 		    &mem->am_dmamap, &mem->am_virtual, &mem->am_physical,
487 		    mem->am_dmaseg, 1, &mem->am_nseg) != 0) {
488 			free(mem->am_dmaseg, M_AGP);
489 			free(mem, M_AGP);
490 			return NULL;
491 		}
492 	} else if (type != 1) {
493 		if (bus_dmamap_create(sc->as_dmat, size, size / PAGE_SIZE + 1,
494 				      size, 0, BUS_DMA_NOWAIT,
495 				      &mem->am_dmamap) != 0) {
496 			free(mem, M_AGP);
497 			return NULL;
498 		}
499 	}
500 
501 	TAILQ_INSERT_TAIL(&sc->as_memory, mem, am_link);
502 	sc->as_allocated += size;
503 
504 	return mem;
505 }
506 
507 static int
508 agp_i810_free_memory(struct agp_softc *sc, struct agp_memory *mem)
509 {
510 	if (mem->am_is_bound)
511 		return EBUSY;
512 
513 	if (mem->am_type == 2) {
514 		agp_free_dmamem(sc->as_dmat, mem->am_size, mem->am_dmamap,
515 		    mem->am_virtual, mem->am_dmaseg, mem->am_nseg);
516 		free(mem->am_dmaseg, M_AGP);
517 	}
518 
519 	sc->as_allocated -= mem->am_size;
520 	TAILQ_REMOVE(&sc->as_memory, mem, am_link);
521 	free(mem, M_AGP);
522 	return 0;
523 }
524 
525 static int
526 agp_i810_bind_memory(struct agp_softc *sc, struct agp_memory *mem,
527 		     off_t offset)
528 {
529 	struct agp_i810_softc *isc = sc->as_chipc;
530 	u_int32_t regval, i;
531 
532 	/*
533 	 * XXX evil hack: the PGTBL_CTL appearently gets overwritten by the
534 	 * X server for mysterious reasons which leads to crashes if we write
535 	 * to the GTT through the MMIO window.
536 	 * Until the issue is solved, simply restore it.
537 	 */
538 	regval = bus_space_read_4(isc->bst, isc->bsh, AGP_I810_PGTBL_CTL);
539 	if (regval != (isc->gatt->ag_physical | 1)) {
540 		printf("agp_i810_bind_memory: PGTBL_CTL is 0x%x - fixing\n",
541 		       regval);
542 		bus_space_write_4(isc->bst, isc->bsh, AGP_I810_PGTBL_CTL,
543 				  isc->gatt->ag_physical | 1);
544 	}
545 
546 	if (mem->am_type == 2) {
547 		WRITE4(AGP_I810_GTT + (u_int32_t)(offset >> AGP_PAGE_SHIFT) * 4,
548 		       mem->am_physical | 1);
549 		mem->am_offset = offset;
550 		mem->am_is_bound = 1;
551 		return 0;
552 	}
553 
554 	if (mem->am_type != 1)
555 		return agp_generic_bind_memory(sc, mem, offset);
556 
557 	if (isc->chiptype == CHIP_I830)
558 		return EINVAL;
559 
560 	for (i = 0; i < mem->am_size; i += AGP_PAGE_SIZE) {
561 		WRITE4(AGP_I810_GTT + (u_int32_t)(offset >> AGP_PAGE_SHIFT) * 4,
562 		       i | 3);
563 	}
564 	mem->am_is_bound = 1;
565 	return 0;
566 }
567 
568 static int
569 agp_i810_unbind_memory(struct agp_softc *sc, struct agp_memory *mem)
570 {
571 	struct agp_i810_softc *isc = sc->as_chipc;
572 	u_int32_t i;
573 
574 	if (mem->am_type == 2) {
575 		WRITE4(AGP_I810_GTT +
576 		       (u_int32_t)(mem->am_offset >> AGP_PAGE_SHIFT) * 4,
577 		       0);
578 		mem->am_offset = 0;
579 		mem->am_is_bound = 0;
580 		return 0;
581 	}
582 
583 	if (mem->am_type != 1)
584 		return agp_generic_unbind_memory(sc, mem);
585 
586 	if (isc->chiptype == CHIP_I830)
587 		return EINVAL;
588 
589 	for (i = 0; i < mem->am_size; i += AGP_PAGE_SIZE)
590 		WRITE4(AGP_I810_GTT + (i >> AGP_PAGE_SHIFT) * 4, 0);
591 	mem->am_is_bound = 0;
592 	return 0;
593 }
594