}
 
 /**
- * intel_vgpu_destroy_mm - destroy a mm object
+ * _intel_vgpu_mm_release - destroy a mm object
  * @mm_ref: a kref object
  *
  * This function is used to destroy a mm object for vGPU
  *
  */
-void intel_vgpu_destroy_mm(struct kref *mm_ref)
+void _intel_vgpu_mm_release(struct kref *mm_ref)
 {
        struct intel_vgpu_mm *mm = container_of(mm_ref, typeof(*mm), ref);
 
 
        list_for_each_safe(pos, n, &vgpu->gtt.ppgtt_mm_list_head) {
                mm = container_of(pos, struct intel_vgpu_mm, ppgtt_mm.list);
-               intel_vgpu_destroy_mm(&mm->ref);
+               intel_vgpu_destroy_mm(mm);
        }
 
        if (GEM_WARN_ON(!list_empty(&vgpu->gtt.ppgtt_mm_list_head)))
 
 static void intel_vgpu_destroy_ggtt_mm(struct intel_vgpu *vgpu)
 {
-       intel_vgpu_destroy_mm(&vgpu->gtt.ggtt_mm->ref);
+       intel_vgpu_destroy_mm(vgpu->gtt.ggtt_mm);
        vgpu->gtt.ggtt_mm = NULL;
 }
 
 
        mm = intel_vgpu_find_ppgtt_mm(vgpu, pdps);
        if (mm) {
-               intel_gvt_mm_reference(mm);
+               intel_vgpu_mm_get(mm);
        } else {
                mm = intel_vgpu_create_ppgtt_mm(vgpu, root_entry_type, pdps);
                if (IS_ERR(mm)) {
                gvt_vgpu_err("fail to find ppgtt instance.\n");
                return -EINVAL;
        }
-       intel_gvt_mm_unreference(mm);
+       intel_vgpu_mm_put(mm);
        return 0;
 }
 
 
 
 struct intel_vgpu_mm *intel_vgpu_create_ppgtt_mm(struct intel_vgpu *vgpu,
                intel_gvt_gtt_type_t root_entry_type, u64 pdps[]);
-extern void intel_vgpu_destroy_mm(struct kref *mm_ref);
+
+static inline void intel_vgpu_mm_get(struct intel_vgpu_mm *mm)
+{
+       kref_get(&mm->ref);
+}
+
+void _intel_vgpu_mm_release(struct kref *mm_ref);
+
+static inline void intel_vgpu_mm_put(struct intel_vgpu_mm *mm)
+{
+       kref_put(&mm->ref, _intel_vgpu_mm_release);
+}
+
+static inline void intel_vgpu_destroy_mm(struct intel_vgpu_mm *mm)
+{
+       intel_vgpu_mm_put(mm);
+}
 
 struct intel_vgpu_guest_page;
 
 
 int intel_vgpu_flush_post_shadow(struct intel_vgpu *vgpu);
 
-static inline void intel_gvt_mm_reference(struct intel_vgpu_mm *mm)
-{
-       kref_get(&mm->ref);
-}
-
-static inline void intel_gvt_mm_unreference(struct intel_vgpu_mm *mm)
-{
-       kref_put(&mm->ref, intel_vgpu_destroy_mm);
-}
-
 int intel_vgpu_pin_mm(struct intel_vgpu_mm *mm);
 
 void intel_vgpu_unpin_mm(struct intel_vgpu_mm *mm);
 
        struct intel_vgpu_submission *s = &workload->vgpu->submission;
 
        if (workload->shadow_mm)
-               intel_gvt_mm_unreference(workload->shadow_mm);
+               intel_vgpu_mm_put(workload->shadow_mm);
 
        kmem_cache_free(s->workloads, workload);
 }
 
        mm = intel_vgpu_find_ppgtt_mm(workload->vgpu, pdps);
        if (mm) {
-               intel_gvt_mm_reference(mm);
+               intel_vgpu_mm_get(mm);
        } else {
 
                mm = intel_vgpu_create_ppgtt_mm(workload->vgpu, root_entry_type,