GFP_DMA32
ret = setup_scratch_page(&ggtt->vm, GFP_DMA32);
if (flags & GFP_DMA32)
glob->dummy_read_page = alloc_page(__GFP_ZERO | GFP_DMA32);
gfp_flags |= GFP_DMA32;
GFP_USER | GFP_DMA32, "wc dma", 0);
GFP_USER | GFP_DMA32, "uc dma", 0);
gfp_flags = GFP_USER | GFP_DMA32;