goto out_free;
 
        memset(&tmp, 0, sizeof(tmp));
+       mutex_lock(&ggtt->vm.mutex);
        err = drm_mm_insert_node_in_range(&ggtt->vm.mm, &tmp,
                                          count * PAGE_SIZE, 0,
                                          I915_COLOR_UNEVICTABLE,
                                          0, ggtt->mappable_end,
                                          DRM_MM_INSERT_LOW);
+       mutex_unlock(&ggtt->vm.mutex);
        if (err)
                goto out_unpin;
 
 out_remove:
        ggtt->vm.clear_range(&ggtt->vm, tmp.start, tmp.size);
        intel_runtime_pm_put(&i915->runtime_pm, wakeref);
+       mutex_lock(&ggtt->vm.mutex);
        drm_mm_remove_node(&tmp);
+       mutex_unlock(&ggtt->vm.mutex);
 out_unpin:
        i915_gem_object_unpin_pages(obj);
 out_free: