/*
* For documentation on the i460 AGP interface, see Chapter 7 (AGP Subsystem) of
* the "Intel 460GTX Chipset Software Developer's Manual":
* http://developer.intel.com/design/itanium/downloads/24870401s.htm
*/
/*
* 460GX support by Chris Ahna <christopher.j.ahna@intel.com>
* Clean up & simplification by David Mosberger-Tang <davidm@hpl.hp.com>
*/
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/agp_backend.h>
#include "agp.h"
#define INTEL_I460_BAPBASE 0x98
#define INTEL_I460_GXBCTL 0xa0
#define INTEL_I460_AGPSIZ 0xa2
#define INTEL_I460_ATTBASE 0xfe200000
#define INTEL_I460_GATT_VALID (1UL << 24)
#define INTEL_I460_GATT_COHERENT (1UL << 25)
/*
* The i460 can operate with large (4MB) pages, but there is no sane way to support this
* within the current kernel/DRM environment, so we disable the relevant code for now.
* See also comments in ia64_alloc_page()...
*/
#define I460_LARGE_IO_PAGES 0
#if I460_LARGE_IO_PAGES
# define I460_IO_PAGE_SHIFT i460.io_page_shift
#else
# define I460_IO_PAGE_SHIFT 12
#endif
#define I460_IOPAGES_PER_KPAGE (PAGE_SIZE >> I460_IO_PAGE_SHIFT)
#define I460_KPAGES_PER_IOPAGE (1 << (I460_IO_PAGE_SHIFT - PAGE_SHIFT))
#define I460_SRAM_IO_DISABLE (1 << 4)
#define I460_BAPBASE_ENABLE (1 << 3)
#define I460_AGPSIZ_MASK 0x7
#define I460_4M_PS (1 << 1)
/* Control bits for Out-Of-GART coherency and Burst Write Combining */
#define I460_GXBCTL_OOG (1UL << 0)
#define I460_GXBCTL_BWC (1UL << 2)
/*
* gatt_table entries are 32-bits wide on the i460; the generic code ought to declare the
* gatt_table and gatt_table_real pointers a "void *"...
*/
#define RD_GATT(index) readl((u32 *) i460.gatt + (index))
#define WR_GATT(index, val) writel((val), (u32 *) i460.gatt + (index))
/*
* The 460 spec says we have to read the last location written to make sure that all
* writes have taken effect
*/
#define WR_FLUSH_GATT(index) RD_GATT(index)
#define log2(x) ffz(~(x))
static struct {
void *gatt; /* ioremap'd GATT area */
/* i460 supports multiple GART page sizes, so GART pageshift is dynamic: */
u8 io_page_shift;
/* BIOS configures chipset to one of 2 possible apbase values: */
u8 dynamic_apbase;
/* structure for tracking partial use of 4MB GART pages: */
struct lp_desc {
unsigned long *alloced_map; /* bitmap of kernel-pages in use */
int refcount; /* number of kernel pages using the large page */
u64 paddr; /* physical address of large page */
} *lp_desc;
} i460;
static struct aper_size_info_8 i460_sizes[3] =
{
/*
* The 32GB aperture is only available with a 4M GART page size. Due to the
* dynamic GART page size, we can't figure out page_order or num_entries until
* runtime.
*/
{32768, 0, 0, 4},
{1024, 0, 0, 2},
{256, 0, 0, 1}
};
static struct gatt_mask i460_masks[] =
{
{
.mask = INTEL_I460_GATT_VALID | INTEL_I460_GATT_COHERENT,
.type = 0
}
};
static int i460_fetch_size (void)
{
int i;
u8 temp;
struct aper_size_info_8 *values;
/* Determine the GART page size */
pci_read_config_byte(agp_bridge->dev, INTEL_I460_GXBCTL, &temp);
i460.io_page_shift = (temp & I460_4M_PS) ? 22 : 12;
pr_debug("i460_fetch_size: io_page_shift=%d\n", i460.io_page_shift);
if (i460.io_page_shift != I460_IO_PAGE_SHIFT) {
printk(KERN_ERR PFX
"I/O (GART) page-size %luKB doesn't match expected "
"size %luKB\n",
1UL << (i460.io_page_shift - 10),
1UL << (I460_IO_PAGE_SHIFT));
return 0;
}
values = A_SIZE_8(agp_bridge->driver->aperture_sizes);
pci_read_config_byte(agp_bridge->dev, INTEL_I460_AGPSIZ, &temp);
/* Exit now if the IO drivers for the GART SRAMS are turned off */
if (temp & I460_SRAM_IO_DISABLE) {
printk(KERN_ERR PFX "GART SRAMS disabled on 460GX chipset\n");
printk(KERN_ERR PFX "AGPGART operation not possible\n");
return 0;
}
/* Make sure we don't try to create an 2 ^ 23 entry GATT */
if ((i460.io_page_shift == 0) && ((temp & I460_AGPSIZ_MASK) == 4)) {
printk(KERN_ERR PFX "We can't have a 32GB aperture with 4KB GART pages\n");
return 0;
}
/* Determine the proper APBASE register */
if (temp & I460_BAPBASE_ENABLE)
i460.dynamic_apbase = INTEL_I460_BAPBASE;
else
i460.dynamic_apbase = AGP_APBASE;
for (i = 0; i < agp_bridge->driver->num_aperture_sizes; i++) {
/*
* Dynamically calculate the proper num_entries and page_order values for
* the define aperture sizes. Take care not to shift off the end of
* values[i].size.
*/
values[i].num_entries = (values[i].size << 8) >> (I460_IO_PAGE_SHIFT - 12);
values[i].page_order = log2((sizeof(u32)*values[i].num_entries) >> PAGE_SHIFT);
}
for (i = 0; i < agp_bridge->driver->num_aperture_sizes; i++) {
/* Neglect control bits when matching up size_value */
if ((temp & I460_AGPSIZ_MASK) == values[i].size_value) {
agp_bridge->previous_size = agp_bridge->current_size = (void *) (values + i);
agp_bridge->aperture_size_idx = i;
return values[i].size;
}
}
return 0;
}
/* There isn't anything to do here since 460 has no GART TLB. */
static void i460_tlb_flush (struct agp_memory *mem)
{
return;
}
/*
* This utility function is needed to prevent corruption of the control bits
* which are stored along with the aperture size in 460's AGPSIZ register
*/
static void i460_write_agpsiz (u8 size_value)
{
u8 temp;
pci_read_config_byte(agp_bridge->dev, INTEL_I460_AGPSIZ, &temp);
pci_write_config_byte(agp_bridge->dev, INTEL_I460_AGPSIZ,
((temp & ~I460_AGPSIZ_MASK) | size_value));
}
static void i460_cleanup (void)
{
struct aper_size_info_8 *previous_size;
previous_size = A_SIZE_8(agp_bridge->previous_size);
i460_write_agpsiz(previous_size->size_value);
if (I460_IO_PAGE_SHIFT > PAGE_SHIFT)
kfree(i460.lp_desc);
}
static int i460_configure (void)
{
union {
u32 small[2];
u64 large;
} temp;
size_t size;
u8 scratch;
struct aper_size_info_8 *current_size;
temp.large = 0;
current_size = A_SIZE_8(agp_bridge->current_size);
i460_write_agpsiz(current_size->size_value);
/*
* Do the necessary rigmarole to read all eight bytes of APBASE.
* This has to be done since the AGP aperture can be above 4GB on
* 460 based systems.
*/
pci_read_config_dword(agp_bridge->dev, i460.dynamic_apbase, &(temp.small[0]));
pci_read_config_dword(agp_bridge->dev, i460.dynamic_apbase + 4, &(temp.small[1]));
/* Clear BAR control bits */
agp_bridge->gart_bus_addr = temp.large & ~((1UL << 3) - 1);
pci_read_config_byte(agp_bridge->dev, INTEL_I460_GXBCTL, &scratch);
pci_write_config_byte(agp_bridge->dev, INTEL_I460_GXBCTL,
(scratch & 0x02) | I460_GXBCTL_OOG | I460_GXBCTL_BWC);
/*
* Initialize partial allocation trackers if a GART page is bigger than a kernel
* page.
*/
if (I460_IO_PAGE_SHIFT > PAGE_SHIFT) {
size = current_size->num_entries * sizeof(i460.lp_desc[0]);
i460.lp_desc = kzalloc(size, GFP_KERNEL);
if (!i460.lp_desc)
return -ENOMEM;
}
return 0;
}
static int i460_create_gatt_table (struct agp_bridge_data *bridge)
{
int page_order, num_entries, i;
void *temp;
/*
* Load up the fixed address of the GART SRAMS which hold our GATT table.
*/
temp = agp_bridge->current_size;
page_order = A_SIZE_8(temp)->page_order;
num_entries = A_SIZE_8(temp)->num_entries;
i460.gatt = ioremap(INTEL_I460_ATTBASE, PAGE_SIZE << page_order);
/* These are no good, the should be removed from the agp_bridge strucure... */
agp_bridge->gatt_table_real = NULL;
agp_bridge->gatt_table = NULL;
agp_bridge->gatt_bus_addr = 0;
for (i = 0; i < num_entries; ++i)
WR_GATT(i, 0);
WR_FLUSH_GATT(i - 1);
return 0;
}
static int i460_free_gatt_table (struct agp_bridge_data *bridge)
{
int num_entries, i;
void *temp;
temp = agp_bridge->current_size;
num_entries = A_SIZE_8(temp)->num_entries;
for (i = 0; i < num_entries; ++i)
WR_GATT(i, 0);
WR_FLUSH_GATT(num_entries - 1);
iounmap(i460.gatt);
return 0;
}
/*
* The following functions are called when the I/O (GART) page size is smaller than
* PAGE_SIZE.
*/
static int i460_insert_memory_small_io_page (struct agp_memory *mem,
off_t pg_start, int type)
{
unsigned long paddr, io_pg_start, io_page_size;
int i, j, k, num_entries;
void *temp;
pr_debug("i460_insert_memory_small_io_page(mem=%p, pg_start=%ld, type=%d, paddr0=0x%lx)\n",
mem, pg_start, type, mem->memory[0]);
io_pg_start = I460_IOPAGES_PER_KPAGE * pg_start;
temp = agp_bridge->current_size;
num_entries = A_SIZE_8(temp)->num_entries;
if ((io_pg_start + I460_IOPAGES_PER_KPAGE * mem->page_count) > num_entries) {
printk(KERN_ERR PFX "Looks like we're out of AGP memory\n");
return -EINVAL;
}
j = io_pg_start;
while (j < (io_pg_start + I460_IOPAGES_PER_KPAGE * mem->page_count)) {
if (!PGE_EMPTY(agp_bridge, RD_GATT(j))) {
pr_debug("i460_insert_memory_small_io_page: GATT[%d]=0x%x is busy\n",
j, RD_GATT(j));
return -EBUSY;
}
j++;
}
io_page_size = 1UL << I460_IO_PAGE_SHIFT;
for (i = 0, j = io_pg_start; i < mem->page_count; i++) {
paddr = mem->memory[i];
for (k = 0; k < I460_IOPAGES_PER_KPAGE; k++, j++, paddr += io_page_size)
WR_GATT(j, agp_bridge->driver->mask_memory(agp_bridge,
paddr, mem->type));
}
WR_FLUSH_GATT(j - 1);
return 0;
}
static int i460_remove_memory_small_io_page(struct agp_memory *mem,
off_t pg_start, int type)
{
int i;
pr_debug("i460_remove_memory_small_io_page(mem=%p, pg_start=%ld, type=%d)\n",
mem, pg_start, type);
pg_start = I460_IOPAGES_PER_KPAGE * pg_start;
for (i = pg_start; i < (pg_start + I460_IOPAGES_PER_KPAGE * mem->page_count); i++)
WR_GATT(i, 0);
WR_FLUSH_GATT(i - 1);
return 0;
}
#if I460_LARGE_IO_PAGES
/*
* These functions are called when the I/O (GART) page size exceeds PAGE_SIZE.
*
* This situation is interesting since AGP memory allocations that are smaller than a
* single GART page are possible. The i460.lp_desc array tracks partial allocation of the
* large GART pages to work around this issue.
*
* i460.lp_desc[pg_num].refcount tracks the number of kernel pages in use within GART page
* pg_num. i460.lp_desc[pg_num].paddr is the physical address of the large page and
* i460.lp_desc[pg_num].alloced_map is a bitmap of kernel pages that are in use (allocated).
*/
static int i460_alloc_large_page (struct lp_desc *lp)
{
unsigned long order = I460_IO_PAGE_SHIFT - PAGE_SHIFT;
size_t map_size;
void *lpage;
lpage = (void *) __get_free_pages(GFP_KERNEL, order);
if (!lpage) {
printk(KERN_ERR PFX "Couldn't alloc 4M GART page...\n");
return -ENOMEM;
}
map_size = ((I460_KPAGES_PER_IOPAGE + BITS_PER_LONG - 1) & -BITS_PER_LONG)/8;
lp->alloced_map = kzalloc(map_size, GFP_KERNEL);
if (!lp->alloced_map) {
free_pages((unsigned long) lpage, order);
printk(KERN_ERR PFX "Out of memory, we're in trouble...\n");
return -ENOMEM;
}
lp->paddr = virt_to_gart(lpage);
lp->refcount = 0;
atomic_add(I460_KPAGES_PER_IOPAGE, &agp_bridge->current_memory_agp);
return 0;
}
static void i460_free_large_page (struct lp_desc *lp)
{
kfree(lp->alloced_map);
lp->alloced_map = NULL;
free_pages((unsigned long) gart_to_virt(lp->paddr), I460_IO_PAGE_SHIFT - PAGE_SHIFT);
atomic_sub(I460_KPAGES_PER_IOPAGE, &agp_bridge->current_memory_agp);
}
static int i460_insert_memory_large_io_page (struct agp_memory *mem,
off_t pg_start, int type)
{
int i, start_offset, end_offset, idx, pg, num_entries;
struct lp_desc *start, *end, *lp;
void *temp;
temp = agp_bridge->current_size;
num_entries = A_SIZE_8(temp)->num_entries;
/* Figure out what pg_start means in terms of our large GART pages */
start = &i460.lp_desc[pg_start / I460_KPAGES_PER_IOPAGE];
end = &i460.lp_desc[(pg_start + mem->page_count - 1) / I460_KPAGES_PER_IOPAGE];
start_offset = pg_start % I460_KPAGES_PER_IOPAGE;
end_offset = (pg_start + mem->page_count - 1) % I460_KPAGES_PER_IOPAGE;
if (end > i460.lp_desc + num_entries) {
printk(KERN_ERR PFX "Looks like we're out of AGP memory\n");
return -EINVAL;
}
/* Check if the requested region of the aperture is free */
for (lp = start; lp <= end; ++lp) {
if (!lp->alloced_map)
continue; /* OK, the entire large page is available... */
for (idx = ((lp == start) ? start_offset : 0);
idx < ((lp == end) ? (end_offset + 1) : I460_KPAGES_PER_IOPAGE);
idx++)
{
if (test_bit(idx, lp->alloced_map))
return -EBUSY;
}
}
for (lp = start, i = 0; lp <= end; ++lp) {
if (!lp->alloced_map) {
/* Allocate new GART pages... */
if (i460_alloc_large_page(lp) < 0)
return -ENOMEM;
pg = lp - i460.lp_desc;
WR_GATT(pg, agp_bridge->driver->mask_memory(agp_bridge,
lp->paddr, 0));
WR_FLUSH_GATT(pg);
}
for (idx = ((lp == start) ? start_offset : 0);
idx < ((lp == end) ? (end_offset + 1) : I460_KPAGES_PER_IOPAGE);
idx++, i++)
{
mem->memory[i] = lp->paddr + idx*PAGE_SIZE;
__set_bit(idx, lp->alloced_map);
++lp->refcount;
}
}
return 0;
}
static int i460_remove_memory_large_io_page (struct agp_memory *mem,
off_t pg_start, int type)
{
int i, pg, start_offset, end_offset, idx, num_entries;
struct lp_desc *start, *end, *lp;
void *temp;
temp = agp_bridge->driver->current_size;
num_entries = A_SIZE_8(temp)->num_entries;
/* Figure out what pg_start means in terms of our large GART pages */
start = &i460.lp_desc[pg_start / I460_KPAGES_PER_IOPAGE];
end = &i460.lp_desc[(pg_start + mem->page_count - 1) / I460_KPAGES_PER_IOPAGE];
start_offset = pg_start % I460_KPAGES_PER_IOPAGE;
end_offset = (pg_start + mem->page_count - 1) % I460_KPAGES_PER_IOPAGE;
for (i = 0, lp = start; lp <= end; ++lp) {
for (idx = ((lp == start) ? start_offset : 0);
idx < ((lp == end) ? (end_offset + 1) : I460_KPAGES_PER_IOPAGE);
idx++, i++)
{
mem->memory[i] = 0;
__clear_bit(idx, lp->alloced_map);
--lp->refcount;
}
/* Free GART pages if they are unused */
if (lp->refcount == 0) {
pg = lp - i460.lp_desc;
WR_GATT(pg, 0);
WR_FLUSH_GATT(pg);
i460_free_large_page(lp);
}
}
return 0;
}
/* Wrapper routines to call the approriate {small_io_page,large_io_page} function */
static int i460_insert_memory (struct agp_memory *mem,
off_t pg_start, int type)
{
if (I460_IO_PAGE_SHIFT <= PAGE_SHIFT)
return i460_insert_memory_small_io_page(mem, pg_start, type);
else
return i460_insert_memory_large_io_page(mem, pg_start, type);
}
static int i460_remove_memory (struct agp_memory *mem,
off_t pg_start, int type)
{
if (I460_IO_PAGE_SHIFT <= PAGE_SHIFT)
return i460_remove_memory_small_io_page(mem, pg_start, type);
else
return i460_remove_memory_large_io_page(mem, pg_start, type);
}
/*
* If the I/O (GART) page size is bigger than the kernel page size, we don't want to
* allocate memory until we know where it is to be bound in the aperture (a
* multi-kernel-page alloc might fit inside of an already allocated GART page).
*
* Let's just hope nobody counts on the allocated AGP memory being there before bind time
* (I don't think current drivers do)...
*/
static void *i460_alloc_page (struct agp_bridge_data *bridge)
{
void *page;
if (I460_IO_PAGE_SHIFT <= PAGE_SHIFT) {
page = agp_generic_alloc_page(agp_bridge);
global_flush_tlb();
} else
/* Returning NULL would cause problems */
/* AK: really dubious code. */
page = (void *)~0UL;
return page;
}
static void i460_destroy_page (void *page)
{
if (I460_IO_PAGE_SHIFT <= PAGE_SHIFT) {
agp_generic_destroy_page(page);
global_flush_tlb();
}
}
#endif /* I460_LARGE_IO_PAGES */
static unsigned long i460_mask_memory (struct agp_bridge_data *bridge,
unsigned long addr, int type)
{
/* Make sure the returned address is a valid GATT entry */
return bridge->driver->masks[0].mask
| (((addr & ~((1 << I460_IO_PAGE_SHIFT) - 1)) & 0xfffff000) >> 12);
}
struct agp_bridge_driver intel_i460_driver = {
.owner = THIS_MODULE,
.aperture_sizes = i460_sizes,
.size_type = U8_APER_SIZE,
.num_aperture_sizes = 3,
.configure = i460_configure,
.fetch_size = i460_fetch_size,
.cleanup = i460_cleanup,
.tlb_flush = i460_tlb_flush,
.mask_memory = i460_mask_memory,
.masks = i460_masks,
.agp_enable = agp_generic_enable,
.cache_flush = global_cache_flush,
.create_gatt_table = i460_create_gatt_table,
.free_gatt_table = i460_free_gatt_table,
#if I460_LARGE_IO_PAGES
.insert_memory = i460_insert_memory,
.remove_memory = i460_remove_memory,
.agp_alloc_page = i460_alloc_page,
.agp_destroy_page = i460_destroy_page,
#else
.insert_memory = i460_insert_memory_small_io_page,
.remove_memory = i460_remove_memory_small_io_page,
.agp_alloc_page = agp_generic_alloc_page,
.agp_destroy_page = agp_generic_destroy_page,
#endif
.alloc_by_type = agp_generic_alloc_by_type,
.free_by_type = agp_generic_free_by_type,
.cant_use_aperture = 1,
};
static int __devinit agp_intel_i460_probe(struct pci_dev *pdev,
const struct pci_device_id *ent)
{
struct agp_bridge_data *bridge;
u8 cap_ptr;
cap_ptr = pci_find_capability(pdev, PCI_CAP_ID_AGP);
if (!cap_ptr)
return -ENODEV;
bridge = agp_alloc_bridge();
if (!bridge)
return -ENOMEM;
bridge->driver = &intel_i460_driver;
bridge->dev = pdev;
bridge->capndx = cap_ptr;
printk(KERN_INFO PFX "Detected Intel 460GX chipset\n");
pci_set_drvdata(pdev, bridge);
return agp_add_bridge(bridge);
}
static void __devexit agp_intel_i460_remove(struct pci_dev *pdev)
{
struct agp_bridge_data *bridge = pci_get_drvdata(pdev);
agp_remove_bridge(bridge);
agp_put_bridge(bridge);
}
static struct pci_device_id agp_intel_i460_pci_table[] = {
{
.class = (PCI_CLASS_BRIDGE_HOST << 8),
.class_mask = ~0,
.vendor = PCI_VENDOR_ID_INTEL,
.device = PCI_DEVICE_ID_INTEL_84460GX,
.subvendor = PCI_ANY_ID,
.subdevice = PCI_ANY_ID,
},
{ }
};
MODULE_DEVICE_TABLE(pci, agp_intel_i460_pci_table);
static struct pci_driver agp_intel_i460_pci_driver = {
.name = "agpgart-intel-i460",
.id_table = agp_intel_i460_pci_table,
.probe = agp_intel_i460_probe,
.remove = __devexit_p(agp_intel_i460_remove),
};
static int __init agp_intel_i460_init(void)
{
if (agp_off)
return -EINVAL;
return pci_register_driver(&agp_intel_i460_pci_driver);
}
static void __exit agp_intel_i460_cleanup(void)
{
pci_unregister_driver(&agp_intel_i460_pci_driver);
}
module_init(agp_intel_i460_init);
module_exit(agp_intel_i460_cleanup);
MODULE_AUTHOR("Chris Ahna <Christopher.J.Ahna@intel.com>");
MODULE_LICENSE("GPL and additional rights");
