xref: /openbmc/linux/drivers/char/agp/i460-agp.c (revision 5f5bac82)
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 #include <linux/log2.h>
17 
18 #include "agp.h"
19 
20 #define INTEL_I460_BAPBASE		0x98
21 #define INTEL_I460_GXBCTL		0xa0
22 #define INTEL_I460_AGPSIZ		0xa2
23 #define INTEL_I460_ATTBASE		0xfe200000
24 #define INTEL_I460_GATT_VALID		(1UL << 24)
25 #define INTEL_I460_GATT_COHERENT	(1UL << 25)
26 
27 /*
28  * The i460 can operate with large (4MB) pages, but there is no sane way to support this
29  * within the current kernel/DRM environment, so we disable the relevant code for now.
30  * See also comments in ia64_alloc_page()...
31  */
32 #define I460_LARGE_IO_PAGES		0
33 
34 #if I460_LARGE_IO_PAGES
35 # define I460_IO_PAGE_SHIFT		i460.io_page_shift
36 #else
37 # define I460_IO_PAGE_SHIFT		12
38 #endif
39 
40 #define I460_IOPAGES_PER_KPAGE		(PAGE_SIZE >> I460_IO_PAGE_SHIFT)
41 #define I460_KPAGES_PER_IOPAGE		(1 << (I460_IO_PAGE_SHIFT - PAGE_SHIFT))
42 #define I460_SRAM_IO_DISABLE		(1 << 4)
43 #define I460_BAPBASE_ENABLE		(1 << 3)
44 #define I460_AGPSIZ_MASK		0x7
45 #define I460_4M_PS			(1 << 1)
46 
47 /* Control bits for Out-Of-GART coherency and Burst Write Combining */
48 #define I460_GXBCTL_OOG		(1UL << 0)
49 #define I460_GXBCTL_BWC		(1UL << 2)
50 
51 /*
52  * gatt_table entries are 32-bits wide on the i460; the generic code ought to declare the
53  * gatt_table and gatt_table_real pointers a "void *"...
54  */
55 #define RD_GATT(index)		readl((u32 *) i460.gatt + (index))
56 #define WR_GATT(index, val)	writel((val), (u32 *) i460.gatt + (index))
57 /*
58  * The 460 spec says we have to read the last location written to make sure that all
59  * writes have taken effect
60  */
61 #define WR_FLUSH_GATT(index)	RD_GATT(index)
62 
63 static struct {
64 	void *gatt;				/* ioremap'd GATT area */
65 
66 	/* i460 supports multiple GART page sizes, so GART pageshift is dynamic: */
67 	u8 io_page_shift;
68 
69 	/* BIOS configures chipset to one of 2 possible apbase values: */
70 	u8 dynamic_apbase;
71 
72 	/* structure for tracking partial use of 4MB GART pages: */
73 	struct lp_desc {
74 		unsigned long *alloced_map;	/* bitmap of kernel-pages in use */
75 		int refcount;			/* number of kernel pages using the large page */
76 		u64 paddr;			/* physical address of large page */
77 	} *lp_desc;
78 } i460;
79 
80 static const struct aper_size_info_8 i460_sizes[3] =
81 {
82 	/*
83 	 * The 32GB aperture is only available with a 4M GART page size.  Due to the
84 	 * dynamic GART page size, we can't figure out page_order or num_entries until
85 	 * runtime.
86 	 */
87 	{32768, 0, 0, 4},
88 	{1024, 0, 0, 2},
89 	{256, 0, 0, 1}
90 };
91 
92 static struct gatt_mask i460_masks[] =
93 {
94 	{
95 	  .mask = INTEL_I460_GATT_VALID | INTEL_I460_GATT_COHERENT,
96 	  .type = 0
97 	}
98 };
99 
100 static int i460_fetch_size (void)
101 {
102 	int i;
103 	u8 temp;
104 	struct aper_size_info_8 *values;
105 
106 	/* Determine the GART page size */
107 	pci_read_config_byte(agp_bridge->dev, INTEL_I460_GXBCTL, &temp);
108 	i460.io_page_shift = (temp & I460_4M_PS) ? 22 : 12;
109 	pr_debug("i460_fetch_size: io_page_shift=%d\n", i460.io_page_shift);
110 
111 	if (i460.io_page_shift != I460_IO_PAGE_SHIFT) {
112 		printk(KERN_ERR PFX
113 			"I/O (GART) page-size %luKB doesn't match expected "
114 				"size %luKB\n",
115 			1UL << (i460.io_page_shift - 10),
116 			1UL << (I460_IO_PAGE_SHIFT));
117 		return 0;
118 	}
119 
120 	values = A_SIZE_8(agp_bridge->driver->aperture_sizes);
121 
122 	pci_read_config_byte(agp_bridge->dev, INTEL_I460_AGPSIZ, &temp);
123 
124 	/* Exit now if the IO drivers for the GART SRAMS are turned off */
125 	if (temp & I460_SRAM_IO_DISABLE) {
126 		printk(KERN_ERR PFX "GART SRAMS disabled on 460GX chipset\n");
127 		printk(KERN_ERR PFX "AGPGART operation not possible\n");
128 		return 0;
129 	}
130 
131 	/* Make sure we don't try to create an 2 ^ 23 entry GATT */
132 	if ((i460.io_page_shift == 0) && ((temp & I460_AGPSIZ_MASK) == 4)) {
133 		printk(KERN_ERR PFX "We can't have a 32GB aperture with 4KB GART pages\n");
134 		return 0;
135 	}
136 
137 	/* Determine the proper APBASE register */
138 	if (temp & I460_BAPBASE_ENABLE)
139 		i460.dynamic_apbase = INTEL_I460_BAPBASE;
140 	else
141 		i460.dynamic_apbase = AGP_APBASE;
142 
143 	for (i = 0; i < agp_bridge->driver->num_aperture_sizes; i++) {
144 		/*
145 		 * Dynamically calculate the proper num_entries and page_order values for
146 		 * the define aperture sizes. Take care not to shift off the end of
147 		 * values[i].size.
148 		 */
149 		values[i].num_entries = (values[i].size << 8) >> (I460_IO_PAGE_SHIFT - 12);
150 		values[i].page_order = ilog2((sizeof(u32)*values[i].num_entries) >> PAGE_SHIFT);
151 	}
152 
153 	for (i = 0; i < agp_bridge->driver->num_aperture_sizes; i++) {
154 		/* Neglect control bits when matching up size_value */
155 		if ((temp & I460_AGPSIZ_MASK) == values[i].size_value) {
156 			agp_bridge->previous_size = agp_bridge->current_size = (void *) (values + i);
157 			agp_bridge->aperture_size_idx = i;
158 			return values[i].size;
159 		}
160 	}
161 
162 	return 0;
163 }
164 
165 /* There isn't anything to do here since 460 has no GART TLB. */
166 static void i460_tlb_flush (struct agp_memory *mem)
167 {
168 	return;
169 }
170 
171 /*
172  * This utility function is needed to prevent corruption of the control bits
173  * which are stored along with the aperture size in 460's AGPSIZ register
174  */
175 static void i460_write_agpsiz (u8 size_value)
176 {
177 	u8 temp;
178 
179 	pci_read_config_byte(agp_bridge->dev, INTEL_I460_AGPSIZ, &temp);
180 	pci_write_config_byte(agp_bridge->dev, INTEL_I460_AGPSIZ,
181 			      ((temp & ~I460_AGPSIZ_MASK) | size_value));
182 }
183 
184 static void i460_cleanup (void)
185 {
186 	struct aper_size_info_8 *previous_size;
187 
188 	previous_size = A_SIZE_8(agp_bridge->previous_size);
189 	i460_write_agpsiz(previous_size->size_value);
190 
191 	if (I460_IO_PAGE_SHIFT > PAGE_SHIFT)
192 		kfree(i460.lp_desc);
193 }
194 
195 static int i460_configure (void)
196 {
197 	union {
198 		u32 small[2];
199 		u64 large;
200 	} temp;
201 	size_t size;
202 	u8 scratch;
203 	struct aper_size_info_8 *current_size;
204 
205 	temp.large = 0;
206 
207 	current_size = A_SIZE_8(agp_bridge->current_size);
208 	i460_write_agpsiz(current_size->size_value);
209 
210 	/*
211 	 * Do the necessary rigmarole to read all eight bytes of APBASE.
212 	 * This has to be done since the AGP aperture can be above 4GB on
213 	 * 460 based systems.
214 	 */
215 	pci_read_config_dword(agp_bridge->dev, i460.dynamic_apbase, &(temp.small[0]));
216 	pci_read_config_dword(agp_bridge->dev, i460.dynamic_apbase + 4, &(temp.small[1]));
217 
218 	/* Clear BAR control bits */
219 	agp_bridge->gart_bus_addr = temp.large & ~((1UL << 3) - 1);
220 
221 	pci_read_config_byte(agp_bridge->dev, INTEL_I460_GXBCTL, &scratch);
222 	pci_write_config_byte(agp_bridge->dev, INTEL_I460_GXBCTL,
223 			      (scratch & 0x02) | I460_GXBCTL_OOG | I460_GXBCTL_BWC);
224 
225 	/*
226 	 * Initialize partial allocation trackers if a GART page is bigger than a kernel
227 	 * page.
228 	 */
229 	if (I460_IO_PAGE_SHIFT > PAGE_SHIFT) {
230 		size = current_size->num_entries * sizeof(i460.lp_desc[0]);
231 		i460.lp_desc = kzalloc(size, GFP_KERNEL);
232 		if (!i460.lp_desc)
233 			return -ENOMEM;
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 	if (!i460.gatt) {
252 		printk(KERN_ERR PFX "ioremap failed\n");
253 		return -ENOMEM;
254 	}
255 
256 	/* These are no good, the should be removed from the agp_bridge strucure... */
257 	agp_bridge->gatt_table_real = NULL;
258 	agp_bridge->gatt_table = NULL;
259 	agp_bridge->gatt_bus_addr = 0;
260 
261 	for (i = 0; i < num_entries; ++i)
262 		WR_GATT(i, 0);
263 	WR_FLUSH_GATT(i - 1);
264 	return 0;
265 }
266 
267 static int i460_free_gatt_table (struct agp_bridge_data *bridge)
268 {
269 	int num_entries, i;
270 	void *temp;
271 
272 	temp = agp_bridge->current_size;
273 
274 	num_entries = A_SIZE_8(temp)->num_entries;
275 
276 	for (i = 0; i < num_entries; ++i)
277 		WR_GATT(i, 0);
278 	WR_FLUSH_GATT(num_entries - 1);
279 
280 	iounmap(i460.gatt);
281 	return 0;
282 }
283 
284 /*
285  * The following functions are called when the I/O (GART) page size is smaller than
286  * PAGE_SIZE.
287  */
288 
289 static int i460_insert_memory_small_io_page (struct agp_memory *mem,
290 				off_t pg_start, int type)
291 {
292 	unsigned long paddr, io_pg_start, io_page_size;
293 	int i, j, k, num_entries;
294 	void *temp;
295 
296 	pr_debug("i460_insert_memory_small_io_page(mem=%p, pg_start=%ld, type=%d, paddr0=0x%lx)\n",
297 		 mem, pg_start, type, mem->memory[0]);
298 
299 	if (type >= AGP_USER_TYPES || mem->type >= AGP_USER_TYPES)
300 		return -EINVAL;
301 
302 	io_pg_start = I460_IOPAGES_PER_KPAGE * pg_start;
303 
304 	temp = agp_bridge->current_size;
305 	num_entries = A_SIZE_8(temp)->num_entries;
306 
307 	if ((io_pg_start + I460_IOPAGES_PER_KPAGE * mem->page_count) > num_entries) {
308 		printk(KERN_ERR PFX "Looks like we're out of AGP memory\n");
309 		return -EINVAL;
310 	}
311 
312 	j = io_pg_start;
313 	while (j < (io_pg_start + I460_IOPAGES_PER_KPAGE * mem->page_count)) {
314 		if (!PGE_EMPTY(agp_bridge, RD_GATT(j))) {
315 			pr_debug("i460_insert_memory_small_io_page: GATT[%d]=0x%x is busy\n",
316 				 j, RD_GATT(j));
317 			return -EBUSY;
318 		}
319 		j++;
320 	}
321 
322 	io_page_size = 1UL << I460_IO_PAGE_SHIFT;
323 	for (i = 0, j = io_pg_start; i < mem->page_count; i++) {
324 		paddr = mem->memory[i];
325 		for (k = 0; k < I460_IOPAGES_PER_KPAGE; k++, j++, paddr += io_page_size)
326 			WR_GATT(j, agp_bridge->driver->mask_memory(agp_bridge,
327 				paddr, mem->type));
328 	}
329 	WR_FLUSH_GATT(j - 1);
330 	return 0;
331 }
332 
333 static int i460_remove_memory_small_io_page(struct agp_memory *mem,
334 				off_t pg_start, int type)
335 {
336 	int i;
337 
338 	pr_debug("i460_remove_memory_small_io_page(mem=%p, pg_start=%ld, type=%d)\n",
339 		 mem, pg_start, type);
340 
341 	pg_start = I460_IOPAGES_PER_KPAGE * pg_start;
342 
343 	for (i = pg_start; i < (pg_start + I460_IOPAGES_PER_KPAGE * mem->page_count); i++)
344 		WR_GATT(i, 0);
345 	WR_FLUSH_GATT(i - 1);
346 	return 0;
347 }
348 
349 #if I460_LARGE_IO_PAGES
350 
351 /*
352  * These functions are called when the I/O (GART) page size exceeds PAGE_SIZE.
353  *
354  * This situation is interesting since AGP memory allocations that are smaller than a
355  * single GART page are possible.  The i460.lp_desc array tracks partial allocation of the
356  * large GART pages to work around this issue.
357  *
358  * i460.lp_desc[pg_num].refcount tracks the number of kernel pages in use within GART page
359  * pg_num.  i460.lp_desc[pg_num].paddr is the physical address of the large page and
360  * i460.lp_desc[pg_num].alloced_map is a bitmap of kernel pages that are in use (allocated).
361  */
362 
363 static int i460_alloc_large_page (struct lp_desc *lp)
364 {
365 	unsigned long order = I460_IO_PAGE_SHIFT - PAGE_SHIFT;
366 	size_t map_size;
367 	void *lpage;
368 
369 	lpage = (void *) __get_free_pages(GFP_KERNEL, order);
370 	if (!lpage) {
371 		printk(KERN_ERR PFX "Couldn't alloc 4M GART page...\n");
372 		return -ENOMEM;
373 	}
374 
375 	map_size = ((I460_KPAGES_PER_IOPAGE + BITS_PER_LONG - 1) & -BITS_PER_LONG)/8;
376 	lp->alloced_map = kzalloc(map_size, GFP_KERNEL);
377 	if (!lp->alloced_map) {
378 		free_pages((unsigned long) lpage, order);
379 		printk(KERN_ERR PFX "Out of memory, we're in trouble...\n");
380 		return -ENOMEM;
381 	}
382 
383 	lp->paddr = virt_to_gart(lpage);
384 	lp->refcount = 0;
385 	atomic_add(I460_KPAGES_PER_IOPAGE, &agp_bridge->current_memory_agp);
386 	return 0;
387 }
388 
389 static void i460_free_large_page (struct lp_desc *lp)
390 {
391 	kfree(lp->alloced_map);
392 	lp->alloced_map = NULL;
393 
394 	free_pages((unsigned long) gart_to_virt(lp->paddr), I460_IO_PAGE_SHIFT - PAGE_SHIFT);
395 	atomic_sub(I460_KPAGES_PER_IOPAGE, &agp_bridge->current_memory_agp);
396 }
397 
398 static int i460_insert_memory_large_io_page (struct agp_memory *mem,
399 				off_t pg_start, int type)
400 {
401 	int i, start_offset, end_offset, idx, pg, num_entries;
402 	struct lp_desc *start, *end, *lp;
403 	void *temp;
404 
405 	if (type >= AGP_USER_TYPES || mem->type >= AGP_USER_TYPES)
406 		return -EINVAL;
407 
408 	temp = agp_bridge->current_size;
409 	num_entries = A_SIZE_8(temp)->num_entries;
410 
411 	/* Figure out what pg_start means in terms of our large GART pages */
412 	start = &i460.lp_desc[pg_start / I460_KPAGES_PER_IOPAGE];
413 	end = &i460.lp_desc[(pg_start + mem->page_count - 1) / I460_KPAGES_PER_IOPAGE];
414 	start_offset = pg_start % I460_KPAGES_PER_IOPAGE;
415 	end_offset = (pg_start + mem->page_count - 1) % I460_KPAGES_PER_IOPAGE;
416 
417 	if (end > i460.lp_desc + num_entries) {
418 		printk(KERN_ERR PFX "Looks like we're out of AGP memory\n");
419 		return -EINVAL;
420 	}
421 
422 	/* Check if the requested region of the aperture is free */
423 	for (lp = start; lp <= end; ++lp) {
424 		if (!lp->alloced_map)
425 			continue;	/* OK, the entire large page is available... */
426 
427 		for (idx = ((lp == start) ? start_offset : 0);
428 		     idx < ((lp == end) ? (end_offset + 1) : I460_KPAGES_PER_IOPAGE);
429 		     idx++)
430 		{
431 			if (test_bit(idx, lp->alloced_map))
432 				return -EBUSY;
433 		}
434 	}
435 
436 	for (lp = start, i = 0; lp <= end; ++lp) {
437 		if (!lp->alloced_map) {
438 			/* Allocate new GART pages... */
439 			if (i460_alloc_large_page(lp) < 0)
440 				return -ENOMEM;
441 			pg = lp - i460.lp_desc;
442 			WR_GATT(pg, agp_bridge->driver->mask_memory(agp_bridge,
443 				lp->paddr, 0));
444 			WR_FLUSH_GATT(pg);
445 		}
446 
447 		for (idx = ((lp == start) ? start_offset : 0);
448 		     idx < ((lp == end) ? (end_offset + 1) : I460_KPAGES_PER_IOPAGE);
449 		     idx++, i++)
450 		{
451 			mem->memory[i] = lp->paddr + idx*PAGE_SIZE;
452 			__set_bit(idx, lp->alloced_map);
453 			++lp->refcount;
454 		}
455 	}
456 	return 0;
457 }
458 
459 static int i460_remove_memory_large_io_page (struct agp_memory *mem,
460 				off_t pg_start, int type)
461 {
462 	int i, pg, start_offset, end_offset, idx, num_entries;
463 	struct lp_desc *start, *end, *lp;
464 	void *temp;
465 
466 	temp = agp_bridge->driver->current_size;
467 	num_entries = A_SIZE_8(temp)->num_entries;
468 
469 	/* Figure out what pg_start means in terms of our large GART pages */
470 	start = &i460.lp_desc[pg_start / I460_KPAGES_PER_IOPAGE];
471 	end = &i460.lp_desc[(pg_start + mem->page_count - 1) / I460_KPAGES_PER_IOPAGE];
472 	start_offset = pg_start % I460_KPAGES_PER_IOPAGE;
473 	end_offset = (pg_start + mem->page_count - 1) % I460_KPAGES_PER_IOPAGE;
474 
475 	for (i = 0, lp = start; lp <= end; ++lp) {
476 		for (idx = ((lp == start) ? start_offset : 0);
477 		     idx < ((lp == end) ? (end_offset + 1) : I460_KPAGES_PER_IOPAGE);
478 		     idx++, i++)
479 		{
480 			mem->memory[i] = 0;
481 			__clear_bit(idx, lp->alloced_map);
482 			--lp->refcount;
483 		}
484 
485 		/* Free GART pages if they are unused */
486 		if (lp->refcount == 0) {
487 			pg = lp - i460.lp_desc;
488 			WR_GATT(pg, 0);
489 			WR_FLUSH_GATT(pg);
490 			i460_free_large_page(lp);
491 		}
492 	}
493 	return 0;
494 }
495 
496 /* Wrapper routines to call the approriate {small_io_page,large_io_page} function */
497 
498 static int i460_insert_memory (struct agp_memory *mem,
499 				off_t pg_start, int type)
500 {
501 	if (I460_IO_PAGE_SHIFT <= PAGE_SHIFT)
502 		return i460_insert_memory_small_io_page(mem, pg_start, type);
503 	else
504 		return i460_insert_memory_large_io_page(mem, pg_start, type);
505 }
506 
507 static int i460_remove_memory (struct agp_memory *mem,
508 				off_t pg_start, int type)
509 {
510 	if (I460_IO_PAGE_SHIFT <= PAGE_SHIFT)
511 		return i460_remove_memory_small_io_page(mem, pg_start, type);
512 	else
513 		return i460_remove_memory_large_io_page(mem, pg_start, type);
514 }
515 
516 /*
517  * If the I/O (GART) page size is bigger than the kernel page size, we don't want to
518  * allocate memory until we know where it is to be bound in the aperture (a
519  * multi-kernel-page alloc might fit inside of an already allocated GART page).
520  *
521  * Let's just hope nobody counts on the allocated AGP memory being there before bind time
522  * (I don't think current drivers do)...
523  */
524 static void *i460_alloc_page (struct agp_bridge_data *bridge)
525 {
526 	void *page;
527 
528 	if (I460_IO_PAGE_SHIFT <= PAGE_SHIFT) {
529 		page = agp_generic_alloc_page(agp_bridge);
530 	} else
531 		/* Returning NULL would cause problems */
532 		/* AK: really dubious code. */
533 		page = (void *)~0UL;
534 	return page;
535 }
536 
537 static void i460_destroy_page (void *page, int flags)
538 {
539 	if (I460_IO_PAGE_SHIFT <= PAGE_SHIFT) {
540 		agp_generic_destroy_page(page, flags);
541 	}
542 }
543 
544 #endif /* I460_LARGE_IO_PAGES */
545 
546 static unsigned long i460_mask_memory (struct agp_bridge_data *bridge,
547 	unsigned long addr, int type)
548 {
549 	/* Make sure the returned address is a valid GATT entry */
550 	return bridge->driver->masks[0].mask
551 		| (((addr & ~((1 << I460_IO_PAGE_SHIFT) - 1)) & 0xfffff000) >> 12);
552 }
553 
554 const struct agp_bridge_driver intel_i460_driver = {
555 	.owner			= THIS_MODULE,
556 	.aperture_sizes		= i460_sizes,
557 	.size_type		= U8_APER_SIZE,
558 	.num_aperture_sizes	= 3,
559 	.configure		= i460_configure,
560 	.fetch_size		= i460_fetch_size,
561 	.cleanup		= i460_cleanup,
562 	.tlb_flush		= i460_tlb_flush,
563 	.mask_memory		= i460_mask_memory,
564 	.masks			= i460_masks,
565 	.agp_enable		= agp_generic_enable,
566 	.cache_flush		= global_cache_flush,
567 	.create_gatt_table	= i460_create_gatt_table,
568 	.free_gatt_table	= i460_free_gatt_table,
569 #if I460_LARGE_IO_PAGES
570 	.insert_memory		= i460_insert_memory,
571 	.remove_memory		= i460_remove_memory,
572 	.agp_alloc_page		= i460_alloc_page,
573 	.agp_destroy_page	= i460_destroy_page,
574 #else
575 	.insert_memory		= i460_insert_memory_small_io_page,
576 	.remove_memory		= i460_remove_memory_small_io_page,
577 	.agp_alloc_page		= agp_generic_alloc_page,
578 	.agp_alloc_pages	= agp_generic_alloc_pages,
579 	.agp_destroy_page	= agp_generic_destroy_page,
580 	.agp_destroy_pages	= agp_generic_destroy_pages,
581 #endif
582 	.alloc_by_type		= agp_generic_alloc_by_type,
583 	.free_by_type		= agp_generic_free_by_type,
584 	.agp_type_to_mask_type  = agp_generic_type_to_mask_type,
585 	.cant_use_aperture	= true,
586 };
587 
588 static int __devinit agp_intel_i460_probe(struct pci_dev *pdev,
589 					  const struct pci_device_id *ent)
590 {
591 	struct agp_bridge_data *bridge;
592 	u8 cap_ptr;
593 
594 	cap_ptr = pci_find_capability(pdev, PCI_CAP_ID_AGP);
595 	if (!cap_ptr)
596 		return -ENODEV;
597 
598 	bridge = agp_alloc_bridge();
599 	if (!bridge)
600 		return -ENOMEM;
601 
602 	bridge->driver = &intel_i460_driver;
603 	bridge->dev = pdev;
604 	bridge->capndx = cap_ptr;
605 
606 	printk(KERN_INFO PFX "Detected Intel 460GX chipset\n");
607 
608 	pci_set_drvdata(pdev, bridge);
609 	return agp_add_bridge(bridge);
610 }
611 
612 static void __devexit agp_intel_i460_remove(struct pci_dev *pdev)
613 {
614 	struct agp_bridge_data *bridge = pci_get_drvdata(pdev);
615 
616 	agp_remove_bridge(bridge);
617 	agp_put_bridge(bridge);
618 }
619 
620 static struct pci_device_id agp_intel_i460_pci_table[] = {
621 	{
622 	.class		= (PCI_CLASS_BRIDGE_HOST << 8),
623 	.class_mask	= ~0,
624 	.vendor		= PCI_VENDOR_ID_INTEL,
625 	.device		= PCI_DEVICE_ID_INTEL_84460GX,
626 	.subvendor	= PCI_ANY_ID,
627 	.subdevice	= PCI_ANY_ID,
628 	},
629 	{ }
630 };
631 
632 MODULE_DEVICE_TABLE(pci, agp_intel_i460_pci_table);
633 
634 static struct pci_driver agp_intel_i460_pci_driver = {
635 	.name		= "agpgart-intel-i460",
636 	.id_table	= agp_intel_i460_pci_table,
637 	.probe		= agp_intel_i460_probe,
638 	.remove		= __devexit_p(agp_intel_i460_remove),
639 };
640 
641 static int __init agp_intel_i460_init(void)
642 {
643 	if (agp_off)
644 		return -EINVAL;
645 	return pci_register_driver(&agp_intel_i460_pci_driver);
646 }
647 
648 static void __exit agp_intel_i460_cleanup(void)
649 {
650 	pci_unregister_driver(&agp_intel_i460_pci_driver);
651 }
652 
653 module_init(agp_intel_i460_init);
654 module_exit(agp_intel_i460_cleanup);
655 
656 MODULE_AUTHOR("Chris Ahna <Christopher.J.Ahna@intel.com>");
657 MODULE_LICENSE("GPL and additional rights");
658