drm/i915: Silently fallback to 4k scratch

If we fail to allocate a 64k hugepage for scratch, we try again with a
normal 4k page (with some loss of efficiency at runtime). As we handle
this gracefully, we do not need a noisy allocation failure warning.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.william.auld@gmail.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171010111005.13625-1-chris@chris-wilson.co.uk
Reviewed-by: Matthew Auld <matthew.william.auld@gmail.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drivers/gpu/drm/i915/i915_gem_gtt.c

@@ -538,7 +538,7 @@ setup_scratch_page(struct i915_address_space *vm, gfp_t gfp)
 	if (i915_vm_is_48bit(vm) &&
 	    HAS_PAGE_SIZES(vm->i915, I915_GTT_PAGE_SIZE_64K)) {
 		order = get_order(I915_GTT_PAGE_SIZE_64K);
-		page = alloc_pages(gfp | __GFP_ZERO, order);
+		page = alloc_pages(gfp | __GFP_ZERO | __GFP_NOWARN, order);
 		if (page) {
 			addr = dma_map_page(vm->dma, page, 0,
 					    I915_GTT_PAGE_SIZE_64K,