[PATCH] AGP: Allocate AGP pages with GFP_DMA32 by default

Not all graphic page remappers support physical addresses over the 4GB
mark for remapping, so while some do (the AMD64 GART always did, and I
just fixed the i965 to do so properly), we're safest off just forcing
GFP_DMA32 allocations to make sure graphics pages get allocated in the
low 32-bit address space by default.

AGP sub-drivers that really care, and can do better, could just choose
to implement their own allocator (or we could add another "64-bit safe"
default allocator for their use), but quite frankly, you're not likely
to care in practice.

So for now, this trivial change means that we won't be allocating pages
that we can't map correctly by mistake on x86-64.

[ On traditional 32-bit x86, this could never happen, because GFP_KERNEL
  would never allocate any highmem memory anyway ]

Acked-by: Andi Kleen <ak@suse.de>
Acked-by: Dave Jones <davej@redhat.com>
Cc: Eric Anholt <eric@anholt.net>
Cc: Keith Packard <keithp@keithp.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>

diff --git a/drivers/char/agp/generic.c b/drivers/char/agp/generic.c
index cc5ea347a8a7899a9e3228289697a2cd88378839..d218575faeed45999f3f96d86347dc064be69021 100644 (file)
--- a/drivers/char/agp/generic.c
+++ b/drivers/char/agp/generic.c
@@ -1042,7 +1042,7 @@ void *agp_generic_alloc_page(struct agp_bridge_data *bridge)
 {
        struct page * page;
 
-       page = alloc_page(GFP_KERNEL);
+       page = alloc_page(GFP_KERNEL | GFP_DMA32);
        if (page == NULL)
                return NULL;
 

diff --git a/drivers/char/agp/intel-agp.c b/drivers/char/agp/intel-agp.c
index 61ac3809f997cbbb9932a8eb3f0428d63195a2d4..64bb57925d194a77fe96484c219dbd4b6b303772 100644 (file)
--- a/drivers/char/agp/intel-agp.c
+++ b/drivers/char/agp/intel-agp.c
@@ -160,7 +160,7 @@ static void *i8xx_alloc_pages(void)
 {
        struct page * page;
 
-       page = alloc_pages(GFP_KERNEL, 2);
+       page = alloc_pages(GFP_KERNEL | GFP_DMA32, 2);
        if (page == NULL)
                return NULL;