2 files changed, 6 insertions, 0 deletions

diff --git a/drivers/gpu/drm/gma500/gem.c b/drivers/gpu/drm/gma500/gem.c
index 9fbb86868e2e..fc7d144bc2d3 100644
--- a/drivers/gpu/drm/gma500/gem.c
+++ b/drivers/gpu/drm/gma500/gem.c
@@ -124,6 +124,8 @@ static int psb_gem_create(struct drm_file *file,
                 dev_err(dev->dev, "GEM init failed for %lld\n", size);
                 return -ENOMEM;
         }
+        /* Limit the object to 32bit mappings */
+        mapping_set_gfp_mask(r->gem.filp->f_mapping, GFP_KERNEL | __GFP_DMA32);
         /* Give the object a handle so we can carry it more easily */
         ret = drm_gem_handle_create(file, &r->gem, &handle);
         if (ret) {
diff --git a/drivers/gpu/drm/gma500/gtt.c b/drivers/gpu/drm/gma500/gtt.c
index db2e823e8951..54e5c9e1e6fa 100644
--- a/drivers/gpu/drm/gma500/gtt.c
+++ b/drivers/gpu/drm/gma500/gtt.c
@@ -39,6 +39,10 @@ static inline uint32_t psb_gtt_mask_pte(uint32_t pfn, int type)
 {
         uint32_t mask = PSB_PTE_VALID;
 
+        /* Ensure we explode rather than put an invalid low mapping of
+           a high mapping page into the gtt */
+        BUG_ON(pfn & ~(0xFFFFFFFF >> PAGE_SHIFT));
+
         if (type & PSB_MMU_CACHED_MEMORY)
                 mask |= PSB_PTE_CACHED;
         if (type & PSB_MMU_RO_MEMORY)