diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index a546a71..1b2d3bd 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4168,6 +4168,8 @@ i915_gem_phys_pwrite(struct drm_device *dev,
 		     struct drm_file *file_priv)
 {
 	void *vaddr = obj->phys_obj->handle->vaddr + args->offset;
+	void *vaddr_end = vaddr + args->size;
+
 	char __user *user_data = (char __user *) (uintptr_t) args->data_ptr;
 
 	if (__copy_from_user_inatomic_nocache(vaddr, user_data, args->size)) {
@@ -4184,6 +4186,11 @@ i915_gem_phys_pwrite(struct drm_device *dev,
 			return -EFAULT;
 	}
 
+	mb();
+	for (; vaddr < vaddr_end; vaddr += boot_cpu_data.x86_clflush_size)
+		clflush(vaddr);
+	mb();
+
 	intel_gtt_chipset_flush();
 	return 0;
 }