From: Linus Torvalds Date: Wed, 22 Nov 2006 22:55:29 +0000 (-0800) Subject: [AGP] Allocate AGP pages with GFP_DMA32 by default X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=66c669baa7d70b8d135da67f36c8dba12cea71b8;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git [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 Acked-by: Dave Jones Cc: Eric Anholt Cc: Keith Packard Signed-off-by: Linus Torvalds --- diff --git a/drivers/char/agp/generic.c b/drivers/char/agp/generic.c index c39200161688..5ff457b41efb 100644 --- a/drivers/char/agp/generic.c +++ b/drivers/char/agp/generic.c @@ -1054,7 +1054,7 @@ 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 aceece71a85d..555b3a8ab49c 100644 --- a/drivers/char/agp/intel-agp.c +++ b/drivers/char/agp/intel-agp.c @@ -169,7 +169,7 @@ 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;