drm/i915/gem: Prevent using pgprot_writecombine() if PAT is not supported

[linux-2.6-microblaze.git] / drivers / gpu / drm / i915 / gem / i915_gem_pages.c

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_pages.c b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
index 49ce577..d6eeefa 100644 (file)
--- a/drivers/gpu/drm/i915/gem/i915_gem_pages.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
@@ -254,6 +254,10 @@ static void *i915_gem_object_map(struct drm_i915_gem_object *obj,
        if (!i915_gem_object_has_struct_page(obj) && type != I915_MAP_WC)
                return NULL;
 
+       if (GEM_WARN_ON(type == I915_MAP_WC &&
+                       !static_cpu_has(X86_FEATURE_PAT)))
+               return NULL;
+
        /* A single page can always be kmapped */
        if (n_pte == 1 && type == I915_MAP_WB) {
                struct page *page = sg_page(sgt->sgl);