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| author | Arjan van dev Ven <arjan@linux.intel.com> | 2008-02-06 05:16:00 +0100 |
|---|---|---|
| committer | Dave Airlie <airlied@linux.ie> | 2008-02-19 14:46:39 +1000 |
| commit | fcea424d31868a78366ad5ee0cb3cc2a4cbe689b (patch) | |
| tree | 9b3a2be661c07d8b094a5489ecafffe4befe5ec0 /drivers/char/agp/amd-k7-agp.c | |
| parent | 16469a0ea0f6b7562eac98ebb8a7c41ce902d0b1 (diff) | |
| download | lwn-fcea424d31868a78366ad5ee0cb3cc2a4cbe689b.tar.gz lwn-fcea424d31868a78366ad5ee0cb3cc2a4cbe689b.zip | |
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>
Diffstat (limited to 'drivers/char/agp/amd-k7-agp.c')
| -rw-r--r-- | drivers/char/agp/amd-k7-agp.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/char/agp/amd-k7-agp.c b/drivers/char/agp/amd-k7-agp.c index 87be46406daf..fca4d7f30443 100644 --- a/drivers/char/agp/amd-k7-agp.c +++ b/drivers/char/agp/amd-k7-agp.c @@ -41,6 +41,7 @@ static int amd_create_page_map(struct amd_page_map *page_map) if (page_map->real == NULL) return -ENOMEM; +#ifndef CONFIG_X86 SetPageReserved(virt_to_page(page_map->real)); global_cache_flush(); page_map->remapped = ioremap_nocache(virt_to_gart(page_map->real), @@ -52,6 +53,10 @@ static int amd_create_page_map(struct amd_page_map *page_map) return -ENOMEM; } global_cache_flush(); +#else + set_memory_uc(page_map->real, 1); + page_map->remapped = page_map->real; +#endif for (i = 0; i < PAGE_SIZE / sizeof(unsigned long); i++) { writel(agp_bridge->scratch_page, page_map->remapped+i); @@ -63,8 +68,12 @@ static int amd_create_page_map(struct amd_page_map *page_map) static void amd_free_page_map(struct amd_page_map *page_map) { +#ifndef CONFIG_X86 iounmap(page_map->remapped); ClearPageReserved(virt_to_page(page_map->real)); +#else + set_memory_wb(page_map->real, 1); +#endif free_page((unsigned long) page_map->real); } |