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
7 * 460GX support by Chris Ahna <christopher.j.ahna@intel.com>
8 * Clean up & simplification by David Mosberger-Tang <davidm@hpl.hp.com>
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>
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)
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()...
31 #define I460_LARGE_IO_PAGES 0
33 #if I460_LARGE_IO_PAGES
34 # define I460_IO_PAGE_SHIFT i460.io_page_shift
36 # define I460_IO_PAGE_SHIFT 12
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)
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)
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 *"...
54 #define RD_GATT(index) readl((u32 *) i460.gatt + (index))
55 #define WR_GATT(index, val) writel((val), (u32 *) i460.gatt + (index))
57 * The 460 spec says we have to read the last location written to make sure that all
58 * writes have taken effect
60 #define WR_FLUSH_GATT(index) RD_GATT(index)
62 #define log2(x) ffz(~(x))
65 void *gatt; /* ioremap'd GATT area */
67 /* i460 supports multiple GART page sizes, so GART pageshift is dynamic: */
70 /* BIOS configures chipset to one of 2 possible apbase values: */
73 /* structure for tracking partial use of 4MB GART pages: */
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 */
81 static struct aper_size_info_8 i460_sizes[3] =
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
93 static struct gatt_mask i460_masks[] =
96 .mask = INTEL_I460_GATT_VALID | INTEL_I460_GATT_COHERENT,
101 static int i460_fetch_size (void)
105 struct aper_size_info_8 *values;
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);
112 if (i460.io_page_shift != I460_IO_PAGE_SHIFT) {
114 "I/O (GART) page-size %luKB doesn't match expected "
116 1UL << (i460.io_page_shift - 10),
117 1UL << (I460_IO_PAGE_SHIFT));
121 values = A_SIZE_8(agp_bridge->driver->aperture_sizes);
123 pci_read_config_byte(agp_bridge->dev, INTEL_I460_AGPSIZ, &temp);
125 /* Exit now if the IO drivers for the GART SRAMS are turned off */
126 if (temp & I460_SRAM_IO_DISABLE) {
127 printk(KERN_ERR PFX "GART SRAMS disabled on 460GX chipset\n");
128 printk(KERN_ERR PFX "AGPGART operation not possible\n");
132 /* Make sure we don't try to create an 2 ^ 23 entry GATT */
133 if ((i460.io_page_shift == 0) && ((temp & I460_AGPSIZ_MASK) == 4)) {
134 printk(KERN_ERR PFX "We can't have a 32GB aperture with 4KB GART pages\n");
138 /* Determine the proper APBASE register */
139 if (temp & I460_BAPBASE_ENABLE)
140 i460.dynamic_apbase = INTEL_I460_BAPBASE;
142 i460.dynamic_apbase = AGP_APBASE;
144 for (i = 0; i < agp_bridge->driver->num_aperture_sizes; i++) {
146 * Dynamically calculate the proper num_entries and page_order values for
147 * the define aperture sizes. Take care not to shift off the end of
150 values[i].num_entries = (values[i].size << 8) >> (I460_IO_PAGE_SHIFT - 12);
151 values[i].page_order = log2((sizeof(u32)*values[i].num_entries) >> PAGE_SHIFT);
154 for (i = 0; i < agp_bridge->driver->num_aperture_sizes; i++) {
155 /* Neglect control bits when matching up size_value */
156 if ((temp & I460_AGPSIZ_MASK) == values[i].size_value) {
157 agp_bridge->previous_size = agp_bridge->current_size = (void *) (values + i);
158 agp_bridge->aperture_size_idx = i;
159 return values[i].size;
166 /* There isn't anything to do here since 460 has no GART TLB. */
167 static void i460_tlb_flush (struct agp_memory *mem)
173 * This utility function is needed to prevent corruption of the control bits
174 * which are stored along with the aperture size in 460's AGPSIZ register
176 static void i460_write_agpsiz (u8 size_value)
180 pci_read_config_byte(agp_bridge->dev, INTEL_I460_AGPSIZ, &temp);
181 pci_write_config_byte(agp_bridge->dev, INTEL_I460_AGPSIZ,
182 ((temp & ~I460_AGPSIZ_MASK) | size_value));
185 static void i460_cleanup (void)
187 struct aper_size_info_8 *previous_size;
189 previous_size = A_SIZE_8(agp_bridge->previous_size);
190 i460_write_agpsiz(previous_size->size_value);
192 if (I460_IO_PAGE_SHIFT > PAGE_SHIFT)
196 static int i460_configure (void)
204 struct aper_size_info_8 *current_size;
208 current_size = A_SIZE_8(agp_bridge->current_size);
209 i460_write_agpsiz(current_size->size_value);
212 * Do the necessary rigmarole to read all eight bytes of APBASE.
213 * This has to be done since the AGP aperture can be above 4GB on
216 pci_read_config_dword(agp_bridge->dev, i460.dynamic_apbase, &(temp.small[0]));
217 pci_read_config_dword(agp_bridge->dev, i460.dynamic_apbase + 4, &(temp.small[1]));
219 /* Clear BAR control bits */
220 agp_bridge->gart_bus_addr = temp.large & ~((1UL << 3) - 1);
222 pci_read_config_byte(agp_bridge->dev, INTEL_I460_GXBCTL, &scratch);
223 pci_write_config_byte(agp_bridge->dev, INTEL_I460_GXBCTL,
224 (scratch & 0x02) | I460_GXBCTL_OOG | I460_GXBCTL_BWC);
227 * Initialize partial allocation trackers if a GART page is bigger than a kernel
230 if (I460_IO_PAGE_SHIFT > PAGE_SHIFT) {
231 size = current_size->num_entries * sizeof(i460.lp_desc[0]);
232 i460.lp_desc = kzalloc(size, GFP_KERNEL);
239 static int i460_create_gatt_table (struct agp_bridge_data *bridge)
241 int page_order, num_entries, i;
245 * Load up the fixed address of the GART SRAMS which hold our GATT table.
247 temp = agp_bridge->current_size;
248 page_order = A_SIZE_8(temp)->page_order;
249 num_entries = A_SIZE_8(temp)->num_entries;
251 i460.gatt = ioremap(INTEL_I460_ATTBASE, PAGE_SIZE << page_order);
253 /* These are no good, the should be removed from the agp_bridge strucure... */
254 agp_bridge->gatt_table_real = NULL;
255 agp_bridge->gatt_table = NULL;
256 agp_bridge->gatt_bus_addr = 0;
258 for (i = 0; i < num_entries; ++i)
260 WR_FLUSH_GATT(i - 1);
264 static int i460_free_gatt_table (struct agp_bridge_data *bridge)
269 temp = agp_bridge->current_size;
271 num_entries = A_SIZE_8(temp)->num_entries;
273 for (i = 0; i < num_entries; ++i)
275 WR_FLUSH_GATT(num_entries - 1);
282 * The following functions are called when the I/O (GART) page size is smaller than
286 static int i460_insert_memory_small_io_page (struct agp_memory *mem,
287 off_t pg_start, int type)
289 unsigned long paddr, io_pg_start, io_page_size;
290 int i, j, k, num_entries;
293 pr_debug("i460_insert_memory_small_io_page(mem=%p, pg_start=%ld, type=%d, paddr0=0x%lx)\n",
294 mem, pg_start, type, mem->memory[0]);
296 io_pg_start = I460_IOPAGES_PER_KPAGE * pg_start;
298 temp = agp_bridge->current_size;
299 num_entries = A_SIZE_8(temp)->num_entries;
301 if ((io_pg_start + I460_IOPAGES_PER_KPAGE * mem->page_count) > num_entries) {
302 printk(KERN_ERR PFX "Looks like we're out of AGP memory\n");
307 while (j < (io_pg_start + I460_IOPAGES_PER_KPAGE * mem->page_count)) {
308 if (!PGE_EMPTY(agp_bridge, RD_GATT(j))) {
309 pr_debug("i460_insert_memory_small_io_page: GATT[%d]=0x%x is busy\n",
316 io_page_size = 1UL << I460_IO_PAGE_SHIFT;
317 for (i = 0, j = io_pg_start; i < mem->page_count; i++) {
318 paddr = mem->memory[i];
319 for (k = 0; k < I460_IOPAGES_PER_KPAGE; k++, j++, paddr += io_page_size)
320 WR_GATT(j, agp_bridge->driver->mask_memory(agp_bridge,
323 WR_FLUSH_GATT(j - 1);
327 static int i460_remove_memory_small_io_page(struct agp_memory *mem,
328 off_t pg_start, int type)
332 pr_debug("i460_remove_memory_small_io_page(mem=%p, pg_start=%ld, type=%d)\n",
333 mem, pg_start, type);
335 pg_start = I460_IOPAGES_PER_KPAGE * pg_start;
337 for (i = pg_start; i < (pg_start + I460_IOPAGES_PER_KPAGE * mem->page_count); i++)
339 WR_FLUSH_GATT(i - 1);
343 #if I460_LARGE_IO_PAGES
346 * These functions are called when the I/O (GART) page size exceeds PAGE_SIZE.
348 * This situation is interesting since AGP memory allocations that are smaller than a
349 * single GART page are possible. The i460.lp_desc array tracks partial allocation of the
350 * large GART pages to work around this issue.
352 * i460.lp_desc[pg_num].refcount tracks the number of kernel pages in use within GART page
353 * pg_num. i460.lp_desc[pg_num].paddr is the physical address of the large page and
354 * i460.lp_desc[pg_num].alloced_map is a bitmap of kernel pages that are in use (allocated).
357 static int i460_alloc_large_page (struct lp_desc *lp)
359 unsigned long order = I460_IO_PAGE_SHIFT - PAGE_SHIFT;
363 lpage = (void *) __get_free_pages(GFP_KERNEL, order);
365 printk(KERN_ERR PFX "Couldn't alloc 4M GART page...\n");
369 map_size = ((I460_KPAGES_PER_IOPAGE + BITS_PER_LONG - 1) & -BITS_PER_LONG)/8;
370 lp->alloced_map = kzalloc(map_size, GFP_KERNEL);
371 if (!lp->alloced_map) {
372 free_pages((unsigned long) lpage, order);
373 printk(KERN_ERR PFX "Out of memory, we're in trouble...\n");
377 lp->paddr = virt_to_gart(lpage);
379 atomic_add(I460_KPAGES_PER_IOPAGE, &agp_bridge->current_memory_agp);
383 static void i460_free_large_page (struct lp_desc *lp)
385 kfree(lp->alloced_map);
386 lp->alloced_map = NULL;
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);
392 static int i460_insert_memory_large_io_page (struct agp_memory *mem,
393 off_t pg_start, int type)
395 int i, start_offset, end_offset, idx, pg, num_entries;
396 struct lp_desc *start, *end, *lp;
399 temp = agp_bridge->current_size;
400 num_entries = A_SIZE_8(temp)->num_entries;
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;
408 if (end > i460.lp_desc + num_entries) {
409 printk(KERN_ERR PFX "Looks like we're out of AGP memory\n");
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... */
418 for (idx = ((lp == start) ? start_offset : 0);
419 idx < ((lp == end) ? (end_offset + 1) : I460_KPAGES_PER_IOPAGE);
422 if (test_bit(idx, lp->alloced_map))
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)
432 pg = lp - i460.lp_desc;
433 WR_GATT(pg, agp_bridge->driver->mask_memory(agp_bridge,
438 for (idx = ((lp == start) ? start_offset : 0);
439 idx < ((lp == end) ? (end_offset + 1) : I460_KPAGES_PER_IOPAGE);
442 mem->memory[i] = lp->paddr + idx*PAGE_SIZE;
443 __set_bit(idx, lp->alloced_map);
450 static int i460_remove_memory_large_io_page (struct agp_memory *mem,
451 off_t pg_start, int type)
453 int i, pg, start_offset, end_offset, idx, num_entries;
454 struct lp_desc *start, *end, *lp;
457 temp = agp_bridge->driver->current_size;
458 num_entries = A_SIZE_8(temp)->num_entries;
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;
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);
472 __clear_bit(idx, lp->alloced_map);
476 /* Free GART pages if they are unused */
477 if (lp->refcount == 0) {
478 pg = lp - i460.lp_desc;
481 i460_free_large_page(lp);
487 /* Wrapper routines to call the approriate {small_io_page,large_io_page} function */
489 static int i460_insert_memory (struct agp_memory *mem,
490 off_t pg_start, int type)
492 if (I460_IO_PAGE_SHIFT <= PAGE_SHIFT)
493 return i460_insert_memory_small_io_page(mem, pg_start, type);
495 return i460_insert_memory_large_io_page(mem, pg_start, type);
498 static int i460_remove_memory (struct agp_memory *mem,
499 off_t pg_start, int type)
501 if (I460_IO_PAGE_SHIFT <= PAGE_SHIFT)
502 return i460_remove_memory_small_io_page(mem, pg_start, type);
504 return i460_remove_memory_large_io_page(mem, pg_start, type);
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).
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)...
515 static void *i460_alloc_page (struct agp_bridge_data *bridge)
519 if (I460_IO_PAGE_SHIFT <= PAGE_SHIFT) {
520 page = agp_generic_alloc_page(agp_bridge);
523 /* Returning NULL would cause problems */
524 /* AK: really dubious code. */
529 static void i460_destroy_page (void *page)
531 if (I460_IO_PAGE_SHIFT <= PAGE_SHIFT) {
532 agp_generic_destroy_page(page);
537 #endif /* I460_LARGE_IO_PAGES */
539 static unsigned long i460_mask_memory (struct agp_bridge_data *bridge,
540 unsigned long addr, int type)
542 /* Make sure the returned address is a valid GATT entry */
543 return bridge->driver->masks[0].mask
544 | (((addr & ~((1 << I460_IO_PAGE_SHIFT) - 1)) & 0xfffff000) >> 12);
547 struct agp_bridge_driver intel_i460_driver = {
548 .owner = THIS_MODULE,
549 .aperture_sizes = i460_sizes,
550 .size_type = U8_APER_SIZE,
551 .num_aperture_sizes = 3,
552 .configure = i460_configure,
553 .fetch_size = i460_fetch_size,
554 .cleanup = i460_cleanup,
555 .tlb_flush = i460_tlb_flush,
556 .mask_memory = i460_mask_memory,
558 .agp_enable = agp_generic_enable,
559 .cache_flush = global_cache_flush,
560 .create_gatt_table = i460_create_gatt_table,
561 .free_gatt_table = i460_free_gatt_table,
562 #if I460_LARGE_IO_PAGES
563 .insert_memory = i460_insert_memory,
564 .remove_memory = i460_remove_memory,
565 .agp_alloc_page = i460_alloc_page,
566 .agp_destroy_page = i460_destroy_page,
568 .insert_memory = i460_insert_memory_small_io_page,
569 .remove_memory = i460_remove_memory_small_io_page,
570 .agp_alloc_page = agp_generic_alloc_page,
571 .agp_destroy_page = agp_generic_destroy_page,
573 .alloc_by_type = agp_generic_alloc_by_type,
574 .free_by_type = agp_generic_free_by_type,
575 .cant_use_aperture = 1,
578 static int __devinit agp_intel_i460_probe(struct pci_dev *pdev,
579 const struct pci_device_id *ent)
581 struct agp_bridge_data *bridge;
584 cap_ptr = pci_find_capability(pdev, PCI_CAP_ID_AGP);
588 bridge = agp_alloc_bridge();
592 bridge->driver = &intel_i460_driver;
594 bridge->capndx = cap_ptr;
596 printk(KERN_INFO PFX "Detected Intel 460GX chipset\n");
598 pci_set_drvdata(pdev, bridge);
599 return agp_add_bridge(bridge);
602 static void __devexit agp_intel_i460_remove(struct pci_dev *pdev)
604 struct agp_bridge_data *bridge = pci_get_drvdata(pdev);
606 agp_remove_bridge(bridge);
607 agp_put_bridge(bridge);
610 static struct pci_device_id agp_intel_i460_pci_table[] = {
612 .class = (PCI_CLASS_BRIDGE_HOST << 8),
614 .vendor = PCI_VENDOR_ID_INTEL,
615 .device = PCI_DEVICE_ID_INTEL_84460GX,
616 .subvendor = PCI_ANY_ID,
617 .subdevice = PCI_ANY_ID,
622 MODULE_DEVICE_TABLE(pci, agp_intel_i460_pci_table);
624 static struct pci_driver agp_intel_i460_pci_driver = {
625 .name = "agpgart-intel-i460",
626 .id_table = agp_intel_i460_pci_table,
627 .probe = agp_intel_i460_probe,
628 .remove = __devexit_p(agp_intel_i460_remove),
631 static int __init agp_intel_i460_init(void)
635 return pci_register_driver(&agp_intel_i460_pci_driver);
638 static void __exit agp_intel_i460_cleanup(void)
640 pci_unregister_driver(&agp_intel_i460_pci_driver);
643 module_init(agp_intel_i460_init);
644 module_exit(agp_intel_i460_cleanup);
646 MODULE_AUTHOR("Chris Ahna <Christopher.J.Ahna@intel.com>");
647 MODULE_LICENSE("GPL and additional rights");