fix historic ioremap() abuse in AGP
Several AGP drivers right now use ioremap_nocache() on kernel ram in order
to turn a page of regular memory uncached.
There are two problems with this:
1) This is a total nightmare for the ioremap() implementation to keep
various mappings of the same page coherent.
2) It's a total nightmare for the AGP code since it adds a ton of
complexity in terms of keeping track of 2 different pointers to
the same thing, in terms of error handling etc etc.
This patch fixes this by making the AGP drivers use the new
set_memory_XX APIs instead.
Note: amd-k7-agp.c is built on Alpha too, and generic.c is built
on ia64 as well, which do not yet have the set_memory_*() APIs,
so for them some we have a few ugly #ifdefs - hopefully they'll
be fixed soon.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Dave Airlie <airlied@linux.ie>
diff --git a/drivers/char/agp/ati-agp.c b/drivers/char/agp/ati-agp.c
index 2d46b71..9ac3bef 100644
--- a/drivers/char/agp/ati-agp.c
+++ b/drivers/char/agp/ati-agp.c
@@ -60,18 +60,9 @@
if (page_map->real == NULL)
return -ENOMEM;
- SetPageReserved(virt_to_page(page_map->real));
+ set_memory_uc(page_map->real, 1);
err = map_page_into_agp(virt_to_page(page_map->real));
- page_map->remapped = ioremap_nocache(virt_to_gart(page_map->real),
- PAGE_SIZE);
- if (page_map->remapped == NULL || err) {
- ClearPageReserved(virt_to_page(page_map->real));
- free_page((unsigned long) page_map->real);
- page_map->real = NULL;
- return -ENOMEM;
- }
- /*CACHE_FLUSH();*/
- global_cache_flush();
+ page_map->remapped = page_map->real;
for (i = 0; i < PAGE_SIZE / sizeof(unsigned long); i++) {
writel(agp_bridge->scratch_page, page_map->remapped+i);
@@ -85,8 +76,7 @@
static void ati_free_page_map(struct ati_page_map *page_map)
{
unmap_page_from_agp(virt_to_page(page_map->real));
- iounmap(page_map->remapped);
- ClearPageReserved(virt_to_page(page_map->real));
+ set_memory_wb(page_map->real, 1);
free_page((unsigned long) page_map->real);
}