From fcea424d31868a78366ad5ee0cb3cc2a4cbe689b Mon Sep 17 00:00:00 2001 From: Arjan van dev Ven Date: Wed, 6 Feb 2008 05:16:00 +0100 Subject: 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 Signed-off-by: Ingo Molnar Signed-off-by: Dave Airlie --- drivers/char/agp/ati-agp.c | 16 +++------------- 1 file changed, 3 insertions(+), 13 deletions(-) (limited to 'drivers/char/agp/ati-agp.c') diff --git a/drivers/char/agp/ati-agp.c b/drivers/char/agp/ati-agp.c index 2d46b713c8f2..9ac3bef3bb7a 100644 --- a/drivers/char/agp/ati-agp.c +++ b/drivers/char/agp/ati-agp.c @@ -60,18 +60,9 @@ static int ati_create_page_map(struct ati_page_map *page_map) 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 int ati_create_page_map(struct ati_page_map *page_map) 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); } -- cgit v1.2.3-59-g8ed1b