xref: /openbmc/linux/drivers/char/agp/i460-agp.c (revision 4e57b6817880946a3a78d5d8cad1ace363f7e449)
1 /*
2  * For documentation on the i460 AGP interface, see Chapter 7 (AGP Subsystem) of
3  * the "Intel 460GTX Chipset Software Developer's Manual":
4  * http://developer.intel.com/design/itanium/downloads/24870401s.htm
5  */
6 /*
7  * 460GX support by Chris Ahna <christopher.j.ahna@intel.com>
8  * Clean up & simplification by David Mosberger-Tang <davidm@hpl.hp.com>
9  */
10 #include <linux/module.h>
11 #include <linux/pci.h>
12 #include <linux/init.h>
13 #include <linux/string.h>
14 #include <linux/slab.h>
15 #include <linux/agp_backend.h>
16 
17 #include "agp.h"
18 
19 #define INTEL_I460_BAPBASE		0x98
20 #define INTEL_I460_GXBCTL		0xa0
21 #define INTEL_I460_AGPSIZ		0xa2
22 #define INTEL_I460_ATTBASE		0xfe200000
23 #define INTEL_I460_GATT_VALID		(1UL << 24)
24 #define INTEL_I460_GATT_COHERENT	(1UL << 25)
25 
26 /*
27  * The i460 can operate with large (4MB) pages, but there is no sane way to support this
28  * within the current kernel/DRM environment, so we disable the relevant code for now.
29  * See also comments in ia64_alloc_page()...
30  */
31 #define I460_LARGE_IO_PAGES		0
32 
33 #if I460_LARGE_IO_PAGES
34 # define I460_IO_PAGE_SHIFT		i460.io_page_shift
35 #else
36 # define I460_IO_PAGE_SHIFT		12
37 #endif
38 
39 #define I460_IOPAGES_PER_KPAGE		(PAGE_SIZE >> I460_IO_PAGE_SHIFT)
40 #define I460_KPAGES_PER_IOPAGE		(1 << (I460_IO_PAGE_SHIFT - PAGE_SHIFT))
41 #define I460_SRAM_IO_DISABLE		(1 << 4)
42 #define I460_BAPBASE_ENABLE		(1 << 3)
43 #define I460_AGPSIZ_MASK		0x7
44 #define I460_4M_PS			(1 << 1)
45 
46 /* Control bits for Out-Of-GART coherency and Burst Write Combining */
47 #define I460_GXBCTL_OOG		(1UL << 0)
48 #define I460_GXBCTL_BWC		(1UL << 2)
49 
50 /*
51  * gatt_table entries are 32-bits wide on the i460; the generic code ought to declare the
52  * gatt_table and gatt_table_real pointers a "void *"...
53  */
54 #define RD_GATT(index)		readl((u32 *) i460.gatt + (index))
55 #define WR_GATT(index, val)	writel((val), (u32 *) i460.gatt + (index))
56 /*
57  * The 460 spec says we have to read the last location written to make sure that all
58  * writes have taken effect
59  */
60 #define WR_FLUSH_GATT(index)	RD_GATT(index)
61 
62 #define log2(x)			ffz(~(x))
63 
64 static struct {
65 	void *gatt;				/* ioremap'd GATT area */
66 
67 	/* i460 supports multiple GART page sizes, so GART pageshift is dynamic: */
68 	u8 io_page_shift;
69 
70 	/* BIOS configures chipset to one of 2 possible apbase values: */
71 	u8 dynamic_apbase;
72 
73 	/* structure for tracking partial use of 4MB GART pages: */
74 	struct lp_desc {
75 		unsigned long *alloced_map;	/* bitmap of kernel-pages in use */
76 		int refcount;			/* number of kernel pages using the large page */
77 		u64 paddr;			/* physical address of large page */
78 	} *lp_desc;
79 } i460;
80 
81 static struct aper_size_info_8 i460_sizes[3] =
82 {
83 	/*
84 	 * The 32GB aperture is only available with a 4M GART page size.  Due to the
85 	 * dynamic GART page size, we can't figure out page_order or num_entries until
86 	 * runtime.
87 	 */
88 	{32768, 0, 0, 4},
89 	{1024, 0, 0, 2},
90 	{256, 0, 0, 1}
91 };
92 
93 static struct gatt_mask i460_masks[] =
94 {
95 	{
96 	  .mask = INTEL_I460_GATT_VALID | INTEL_I460_GATT_COHERENT,
97 	  .type = 0
98 	}
99 };
100 
101 static int i460_fetch_size (void)
102 {
103 	int i;
104 	u8 temp;
105 	struct aper_size_info_8 *values;
106 
107 	/* Determine the GART page size */
108 	pci_read_config_byte(agp_bridge->dev, INTEL_I460_GXBCTL, &temp);
109 	i460.io_page_shift = (temp & I460_4M_PS) ? 22 : 12;
110 	pr_debug("i460_fetch_size: io_page_shift=%d\n", i460.io_page_shift);
111 
112 	if (i460.io_page_shift != I460_IO_PAGE_SHIFT) {
113 		printk(KERN_ERR PFX
114 		       "I/O (GART) page-size %ZuKB doesn't match expected size %ZuKB\n",
115 		       1UL << (i460.io_page_shift - 10), 1UL << (I460_IO_PAGE_SHIFT));
116 		return 0;
117 	}
118 
119 	values = A_SIZE_8(agp_bridge->driver->aperture_sizes);
120 
121 	pci_read_config_byte(agp_bridge->dev, INTEL_I460_AGPSIZ, &temp);
122 
123 	/* Exit now if the IO drivers for the GART SRAMS are turned off */
124 	if (temp & I460_SRAM_IO_DISABLE) {
125 		printk(KERN_ERR PFX "GART SRAMS disabled on 460GX chipset\n");
126 		printk(KERN_ERR PFX "AGPGART operation not possible\n");
127 		return 0;
128 	}
129 
130 	/* Make sure we don't try to create an 2 ^ 23 entry GATT */
131 	if ((i460.io_page_shift == 0) && ((temp & I460_AGPSIZ_MASK) == 4)) {
132 		printk(KERN_ERR PFX "We can't have a 32GB aperture with 4KB GART pages\n");
133 		return 0;
134 	}
135 
136 	/* Determine the proper APBASE register */
137 	if (temp & I460_BAPBASE_ENABLE)
138 		i460.dynamic_apbase = INTEL_I460_BAPBASE;
139 	else
140 		i460.dynamic_apbase = AGP_APBASE;
141 
142 	for (i = 0; i < agp_bridge->driver->num_aperture_sizes; i++) {
143 		/*
144 		 * Dynamically calculate the proper num_entries and page_order values for
145 		 * the define aperture sizes. Take care not to shift off the end of
146 		 * values[i].size.
147 		 */
148 		values[i].num_entries = (values[i].size << 8) >> (I460_IO_PAGE_SHIFT - 12);
149 		values[i].page_order = log2((sizeof(u32)*values[i].num_entries) >> PAGE_SHIFT);
150 	}
151 
152 	for (i = 0; i < agp_bridge->driver->num_aperture_sizes; i++) {
153 		/* Neglect control bits when matching up size_value */
154 		if ((temp & I460_AGPSIZ_MASK) == values[i].size_value) {
155 			agp_bridge->previous_size = agp_bridge->current_size = (void *) (values + i);
156 			agp_bridge->aperture_size_idx = i;
157 			return values[i].size;
158 		}
159 	}
160 
161 	return 0;
162 }
163 
164 /* There isn't anything to do here since 460 has no GART TLB. */
165 static void i460_tlb_flush (struct agp_memory *mem)
166 {
167 	return;
168 }
169 
170 /*
171  * This utility function is needed to prevent corruption of the control bits
172  * which are stored along with the aperture size in 460's AGPSIZ register
173  */
174 static void i460_write_agpsiz (u8 size_value)
175 {
176 	u8 temp;
177 
178 	pci_read_config_byte(agp_bridge->dev, INTEL_I460_AGPSIZ, &temp);
179 	pci_write_config_byte(agp_bridge->dev, INTEL_I460_AGPSIZ,
180 			      ((temp & ~I460_AGPSIZ_MASK) | size_value));
181 }
182 
183 static void i460_cleanup (void)
184 {
185 	struct aper_size_info_8 *previous_size;
186 
187 	previous_size = A_SIZE_8(agp_bridge->previous_size);
188 	i460_write_agpsiz(previous_size->size_value);
189 
190 	if (I460_IO_PAGE_SHIFT > PAGE_SHIFT)
191 		kfree(i460.lp_desc);
192 }
193 
194 static int i460_configure (void)
195 {
196 	union {
197 		u32 small[2];
198 		u64 large;
199 	} temp;
200 	size_t size;
201 	u8 scratch;
202 	struct aper_size_info_8 *current_size;
203 
204 	temp.large = 0;
205 
206 	current_size = A_SIZE_8(agp_bridge->current_size);
207 	i460_write_agpsiz(current_size->size_value);
208 
209 	/*
210 	 * Do the necessary rigmarole to read all eight bytes of APBASE.
211 	 * This has to be done since the AGP aperture can be above 4GB on
212 	 * 460 based systems.
213 	 */
214 	pci_read_config_dword(agp_bridge->dev, i460.dynamic_apbase, &(temp.small[0]));
215 	pci_read_config_dword(agp_bridge->dev, i460.dynamic_apbase + 4, &(temp.small[1]));
216 
217 	/* Clear BAR control bits */
218 	agp_bridge->gart_bus_addr = temp.large & ~((1UL << 3) - 1);
219 
220 	pci_read_config_byte(agp_bridge->dev, INTEL_I460_GXBCTL, &scratch);
221 	pci_write_config_byte(agp_bridge->dev, INTEL_I460_GXBCTL,
222 			      (scratch & 0x02) | I460_GXBCTL_OOG | I460_GXBCTL_BWC);
223 
224 	/*
225 	 * Initialize partial allocation trackers if a GART page is bigger than a kernel
226 	 * page.
227 	 */
228 	if (I460_IO_PAGE_SHIFT > PAGE_SHIFT) {
229 		size = current_size->num_entries * sizeof(i460.lp_desc[0]);
230 		i460.lp_desc = kmalloc(size, GFP_KERNEL);
231 		if (!i460.lp_desc)
232 			return -ENOMEM;
233 		memset(i460.lp_desc, 0, size);
234 	}
235 	return 0;
236 }
237 
238 static int i460_create_gatt_table (struct agp_bridge_data *bridge)
239 {
240 	int page_order, num_entries, i;
241 	void *temp;
242 
243 	/*
244 	 * Load up the fixed address of the GART SRAMS which hold our GATT table.
245 	 */
246 	temp = agp_bridge->current_size;
247 	page_order = A_SIZE_8(temp)->page_order;
248 	num_entries = A_SIZE_8(temp)->num_entries;
249 
250 	i460.gatt = ioremap(INTEL_I460_ATTBASE, PAGE_SIZE << page_order);
251 
252 	/* These are no good, the should be removed from the agp_bridge strucure... */
253 	agp_bridge->gatt_table_real = NULL;
254 	agp_bridge->gatt_table = NULL;
255 	agp_bridge->gatt_bus_addr = 0;
256 
257 	for (i = 0; i < num_entries; ++i)
258 		WR_GATT(i, 0);
259 	WR_FLUSH_GATT(i - 1);
260 	return 0;
261 }
262 
263 static int i460_free_gatt_table (struct agp_bridge_data *bridge)
264 {
265 	int num_entries, i;
266 	void *temp;
267 
268 	temp = agp_bridge->current_size;
269 
270 	num_entries = A_SIZE_8(temp)->num_entries;
271 
272 	for (i = 0; i < num_entries; ++i)
273 		WR_GATT(i, 0);
274 	WR_FLUSH_GATT(num_entries - 1);
275 
276 	iounmap(i460.gatt);
277 	return 0;
278 }
279 
280 /*
281  * The following functions are called when the I/O (GART) page size is smaller than
282  * PAGE_SIZE.
283  */
284 
285 static int i460_insert_memory_small_io_page (struct agp_memory *mem,
286 				off_t pg_start, int type)
287 {
288 	unsigned long paddr, io_pg_start, io_page_size;
289 	int i, j, k, num_entries;
290 	void *temp;
291 
292 	pr_debug("i460_insert_memory_small_io_page(mem=%p, pg_start=%ld, type=%d, paddr0=0x%lx)\n",
293 		 mem, pg_start, type, mem->memory[0]);
294 
295 	io_pg_start = I460_IOPAGES_PER_KPAGE * pg_start;
296 
297 	temp = agp_bridge->current_size;
298 	num_entries = A_SIZE_8(temp)->num_entries;
299 
300 	if ((io_pg_start + I460_IOPAGES_PER_KPAGE * mem->page_count) > num_entries) {
301 		printk(KERN_ERR PFX "Looks like we're out of AGP memory\n");
302 		return -EINVAL;
303 	}
304 
305 	j = io_pg_start;
306 	while (j < (io_pg_start + I460_IOPAGES_PER_KPAGE * mem->page_count)) {
307 		if (!PGE_EMPTY(agp_bridge, RD_GATT(j))) {
308 			pr_debug("i460_insert_memory_small_io_page: GATT[%d]=0x%x is busy\n",
309 				 j, RD_GATT(j));
310 			return -EBUSY;
311 		}
312 		j++;
313 	}
314 
315 	io_page_size = 1UL << I460_IO_PAGE_SHIFT;
316 	for (i = 0, j = io_pg_start; i < mem->page_count; i++) {
317 		paddr = mem->memory[i];
318 		for (k = 0; k < I460_IOPAGES_PER_KPAGE; k++, j++, paddr += io_page_size)
319 			WR_GATT(j, agp_bridge->driver->mask_memory(agp_bridge,
320 				paddr, mem->type));
321 	}
322 	WR_FLUSH_GATT(j - 1);
323 	return 0;
324 }
325 
326 static int i460_remove_memory_small_io_page(struct agp_memory *mem,
327 				off_t pg_start, int type)
328 {
329 	int i;
330 
331 	pr_debug("i460_remove_memory_small_io_page(mem=%p, pg_start=%ld, type=%d)\n",
332 		 mem, pg_start, type);
333 
334 	pg_start = I460_IOPAGES_PER_KPAGE * pg_start;
335 
336 	for (i = pg_start; i < (pg_start + I460_IOPAGES_PER_KPAGE * mem->page_count); i++)
337 		WR_GATT(i, 0);
338 	WR_FLUSH_GATT(i - 1);
339 	return 0;
340 }
341 
342 #if I460_LARGE_IO_PAGES
343 
344 /*
345  * These functions are called when the I/O (GART) page size exceeds PAGE_SIZE.
346  *
347  * This situation is interesting since AGP memory allocations that are smaller than a
348  * single GART page are possible.  The i460.lp_desc array tracks partial allocation of the
349  * large GART pages to work around this issue.
350  *
351  * i460.lp_desc[pg_num].refcount tracks the number of kernel pages in use within GART page
352  * pg_num.  i460.lp_desc[pg_num].paddr is the physical address of the large page and
353  * i460.lp_desc[pg_num].alloced_map is a bitmap of kernel pages that are in use (allocated).
354  */
355 
356 static int i460_alloc_large_page (struct lp_desc *lp)
357 {
358 	unsigned long order = I460_IO_PAGE_SHIFT - PAGE_SHIFT;
359 	size_t map_size;
360 	void *lpage;
361 
362 	lpage = (void *) __get_free_pages(GFP_KERNEL, order);
363 	if (!lpage) {
364 		printk(KERN_ERR PFX "Couldn't alloc 4M GART page...\n");
365 		return -ENOMEM;
366 	}
367 
368 	map_size = ((I460_KPAGES_PER_IOPAGE + BITS_PER_LONG - 1) & -BITS_PER_LONG)/8;
369 	lp->alloced_map = kmalloc(map_size, GFP_KERNEL);
370 	if (!lp->alloced_map) {
371 		free_pages((unsigned long) lpage, order);
372 		printk(KERN_ERR PFX "Out of memory, we're in trouble...\n");
373 		return -ENOMEM;
374 	}
375 	memset(lp->alloced_map, 0, map_size);
376 
377 	lp->paddr = virt_to_gart(lpage);
378 	lp->refcount = 0;
379 	atomic_add(I460_KPAGES_PER_IOPAGE, &agp_bridge->current_memory_agp);
380 	return 0;
381 }
382 
383 static void i460_free_large_page (struct lp_desc *lp)
384 {
385 	kfree(lp->alloced_map);
386 	lp->alloced_map = NULL;
387 
388 	free_pages((unsigned long) gart_to_virt(lp->paddr), I460_IO_PAGE_SHIFT - PAGE_SHIFT);
389 	atomic_sub(I460_KPAGES_PER_IOPAGE, &agp_bridge->current_memory_agp);
390 }
391 
392 static int i460_insert_memory_large_io_page (struct agp_memory *mem,
393 				off_t pg_start, int type)
394 {
395 	int i, start_offset, end_offset, idx, pg, num_entries;
396 	struct lp_desc *start, *end, *lp;
397 	void *temp;
398 
399 	temp = agp_bridge->current_size;
400 	num_entries = A_SIZE_8(temp)->num_entries;
401 
402 	/* Figure out what pg_start means in terms of our large GART pages */
403 	start	 	= &i460.lp_desc[pg_start / I460_KPAGES_PER_IOPAGE];
404 	end 		= &i460.lp_desc[(pg_start + mem->page_count - 1) / I460_KPAGES_PER_IOPAGE];
405 	start_offset 	= pg_start % I460_KPAGES_PER_IOPAGE;
406 	end_offset 	= (pg_start + mem->page_count - 1) % I460_KPAGES_PER_IOPAGE;
407 
408 	if (end > i460.lp_desc + num_entries) {
409 		printk(KERN_ERR PFX "Looks like we're out of AGP memory\n");
410 		return -EINVAL;
411 	}
412 
413 	/* Check if the requested region of the aperture is free */
414 	for (lp = start; lp <= end; ++lp) {
415 		if (!lp->alloced_map)
416 			continue;	/* OK, the entire large page is available... */
417 
418 		for (idx = ((lp == start) ? start_offset : 0);
419 		     idx < ((lp == end) ? (end_offset + 1) : I460_KPAGES_PER_IOPAGE);
420 		     idx++)
421 		{
422 			if (test_bit(idx, lp->alloced_map))
423 				return -EBUSY;
424 		}
425 	}
426 
427 	for (lp = start, i = 0; lp <= end; ++lp) {
428 		if (!lp->alloced_map) {
429 			/* Allocate new GART pages... */
430 			if (i460_alloc_large_page(lp) < 0)
431 				return -ENOMEM;
432 			pg = lp - i460.lp_desc;
433 			WR_GATT(pg, agp_bridge->driver->mask_memory(agp_bridge,
434 				lp->paddr, 0));
435 			WR_FLUSH_GATT(pg);
436 		}
437 
438 		for (idx = ((lp == start) ? start_offset : 0);
439 		     idx < ((lp == end) ? (end_offset + 1) : I460_KPAGES_PER_IOPAGE);
440 		     idx++, i++)
441 		{
442 			mem->memory[i] = lp->paddr + idx*PAGE_SIZE;
443 			__set_bit(idx, lp->alloced_map);
444 			++lp->refcount;
445 		}
446 	}
447 	return 0;
448 }
449 
450 static int i460_remove_memory_large_io_page (struct agp_memory *mem,
451 				off_t pg_start, int type)
452 {
453 	int i, pg, start_offset, end_offset, idx, num_entries;
454 	struct lp_desc *start, *end, *lp;
455 	void *temp;
456 
457 	temp = agp_bridge->driver->current_size;
458 	num_entries = A_SIZE_8(temp)->num_entries;
459 
460 	/* Figure out what pg_start means in terms of our large GART pages */
461 	start	 	= &i460.lp_desc[pg_start / I460_KPAGES_PER_IOPAGE];
462 	end 		= &i460.lp_desc[(pg_start + mem->page_count - 1) / I460_KPAGES_PER_IOPAGE];
463 	start_offset 	= pg_start % I460_KPAGES_PER_IOPAGE;
464 	end_offset 	= (pg_start + mem->page_count - 1) % I460_KPAGES_PER_IOPAGE;
465 
466 	for (i = 0, lp = start; lp <= end; ++lp) {
467 		for (idx = ((lp == start) ? start_offset : 0);
468 		     idx < ((lp == end) ? (end_offset + 1) : I460_KPAGES_PER_IOPAGE);
469 		     idx++, i++)
470 		{
471 			mem->memory[i] = 0;
472 			__clear_bit(idx, lp->alloced_map);
473 			--lp->refcount;
474 		}
475 
476 		/* Free GART pages if they are unused */
477 		if (lp->refcount == 0) {
478 			pg = lp - i460.lp_desc;
479 			WR_GATT(pg, 0);
480 			WR_FLUSH_GATT(pg);
481 			i460_free_large_page(lp);
482 		}
483 	}
484 	return 0;
485 }
486 
487 /* Wrapper routines to call the approriate {small_io_page,large_io_page} function */
488 
489 static int i460_insert_memory (struct agp_memory *mem,
490 				off_t pg_start, int type)
491 {
492 	if (I460_IO_PAGE_SHIFT <= PAGE_SHIFT)
493 		return i460_insert_memory_small_io_page(mem, pg_start, type);
494 	else
495 		return i460_insert_memory_large_io_page(mem, pg_start, type);
496 }
497 
498 static int i460_remove_memory (struct agp_memory *mem,
499 				off_t pg_start, int type)
500 {
501 	if (I460_IO_PAGE_SHIFT <= PAGE_SHIFT)
502 		return i460_remove_memory_small_io_page(mem, pg_start, type);
503 	else
504 		return i460_remove_memory_large_io_page(mem, pg_start, type);
505 }
506 
507 /*
508  * If the I/O (GART) page size is bigger than the kernel page size, we don't want to
509  * allocate memory until we know where it is to be bound in the aperture (a
510  * multi-kernel-page alloc might fit inside of an already allocated GART page).
511  *
512  * Let's just hope nobody counts on the allocated AGP memory being there before bind time
513  * (I don't think current drivers do)...
514  */
515 static void *i460_alloc_page (struct agp_bridge_data *bridge)
516 {
517 	void *page;
518 
519 	if (I460_IO_PAGE_SHIFT <= PAGE_SHIFT)
520 		page = agp_generic_alloc_page(agp_bridge);
521 	else
522 		/* Returning NULL would cause problems */
523 		/* AK: really dubious code. */
524 		page = (void *)~0UL;
525 	return page;
526 }
527 
528 static void i460_destroy_page (void *page)
529 {
530 	if (I460_IO_PAGE_SHIFT <= PAGE_SHIFT)
531 		agp_generic_destroy_page(page);
532 }
533 
534 #endif /* I460_LARGE_IO_PAGES */
535 
536 static unsigned long i460_mask_memory (struct agp_bridge_data *bridge,
537 	unsigned long addr, int type)
538 {
539 	/* Make sure the returned address is a valid GATT entry */
540 	return bridge->driver->masks[0].mask
541 		| (((addr & ~((1 << I460_IO_PAGE_SHIFT) - 1)) & 0xffffff000) >> 12);
542 }
543 
544 struct agp_bridge_driver intel_i460_driver = {
545 	.owner			= THIS_MODULE,
546 	.aperture_sizes		= i460_sizes,
547 	.size_type		= U8_APER_SIZE,
548 	.num_aperture_sizes	= 3,
549 	.configure		= i460_configure,
550 	.fetch_size		= i460_fetch_size,
551 	.cleanup		= i460_cleanup,
552 	.tlb_flush		= i460_tlb_flush,
553 	.mask_memory		= i460_mask_memory,
554 	.masks			= i460_masks,
555 	.agp_enable		= agp_generic_enable,
556 	.cache_flush		= global_cache_flush,
557 	.create_gatt_table	= i460_create_gatt_table,
558 	.free_gatt_table	= i460_free_gatt_table,
559 #if I460_LARGE_IO_PAGES
560 	.insert_memory		= i460_insert_memory,
561 	.remove_memory		= i460_remove_memory,
562 	.agp_alloc_page		= i460_alloc_page,
563 	.agp_destroy_page	= i460_destroy_page,
564 #else
565 	.insert_memory		= i460_insert_memory_small_io_page,
566 	.remove_memory		= i460_remove_memory_small_io_page,
567 	.agp_alloc_page		= agp_generic_alloc_page,
568 	.agp_destroy_page	= agp_generic_destroy_page,
569 #endif
570 	.alloc_by_type		= agp_generic_alloc_by_type,
571 	.free_by_type		= agp_generic_free_by_type,
572 	.cant_use_aperture	= 1,
573 };
574 
575 static int __devinit agp_intel_i460_probe(struct pci_dev *pdev,
576 					  const struct pci_device_id *ent)
577 {
578 	struct agp_bridge_data *bridge;
579 	u8 cap_ptr;
580 
581 	cap_ptr = pci_find_capability(pdev, PCI_CAP_ID_AGP);
582 	if (!cap_ptr)
583 		return -ENODEV;
584 
585 	bridge = agp_alloc_bridge();
586 	if (!bridge)
587 		return -ENOMEM;
588 
589 	bridge->driver = &intel_i460_driver;
590 	bridge->dev = pdev;
591 	bridge->capndx = cap_ptr;
592 
593 	printk(KERN_INFO PFX "Detected Intel 460GX chipset\n");
594 
595 	pci_set_drvdata(pdev, bridge);
596 	return agp_add_bridge(bridge);
597 }
598 
599 static void __devexit agp_intel_i460_remove(struct pci_dev *pdev)
600 {
601 	struct agp_bridge_data *bridge = pci_get_drvdata(pdev);
602 
603 	agp_remove_bridge(bridge);
604 	agp_put_bridge(bridge);
605 }
606 
607 static struct pci_device_id agp_intel_i460_pci_table[] = {
608 	{
609 	.class		= (PCI_CLASS_BRIDGE_HOST << 8),
610 	.class_mask	= ~0,
611 	.vendor		= PCI_VENDOR_ID_INTEL,
612 	.device		= PCI_DEVICE_ID_INTEL_84460GX,
613 	.subvendor	= PCI_ANY_ID,
614 	.subdevice	= PCI_ANY_ID,
615 	},
616 	{ }
617 };
618 
619 MODULE_DEVICE_TABLE(pci, agp_intel_i460_pci_table);
620 
621 static struct pci_driver agp_intel_i460_pci_driver = {
622 	.name		= "agpgart-intel-i460",
623 	.id_table	= agp_intel_i460_pci_table,
624 	.probe		= agp_intel_i460_probe,
625 	.remove		= __devexit_p(agp_intel_i460_remove),
626 };
627 
628 static int __init agp_intel_i460_init(void)
629 {
630 	if (agp_off)
631 		return -EINVAL;
632 	return pci_register_driver(&agp_intel_i460_pci_driver);
633 }
634 
635 static void __exit agp_intel_i460_cleanup(void)
636 {
637 	pci_unregister_driver(&agp_intel_i460_pci_driver);
638 }
639 
640 module_init(agp_intel_i460_init);
641 module_exit(agp_intel_i460_cleanup);
642 
643 MODULE_AUTHOR("Chris Ahna <Christopher.J.Ahna@intel.com>");
644 MODULE_LICENSE("GPL and additional rights");
645