}
 
                if (nfit_mem->bdw && nfit_mem->memdev_pmem)
-                       flags |= NDD_ALIASING;
+                       set_bit(NDD_ALIASING, &flags);
 
                /* collate flags across all memdevs for this dimm */
                list_for_each_entry(nfit_memdev, &acpi_desc->memdevs, list) {
 
                mem_flags = __to_nfit_memdev(nfit_mem)->flags;
                if (mem_flags & ACPI_NFIT_MEM_NOT_ARMED)
-                       flags |= NDD_UNARMED;
+                       set_bit(NDD_UNARMED, &flags);
 
                rc = acpi_nfit_add_dimm(acpi_desc, nfit_mem, device_handle);
                if (rc)
 
 
        if (!nvdimm->cmd_mask ||
            !test_bit(ND_CMD_GET_CONFIG_DATA, &nvdimm->cmd_mask)) {
-               if (nvdimm->flags & NDD_ALIASING)
+               if (test_bit(NDD_ALIASING, &nvdimm->flags))
                        return -ENXIO;
                else
                        return -ENOTTY;
 {
        struct nvdimm *nvdimm = to_nvdimm(dev);
 
-       nvdimm->flags |= NDD_ALIASING;
+       set_bit(NDD_ALIASING, &nvdimm->flags);
+}
+
+void nvdimm_set_locked(struct device *dev)
+{
+       struct nvdimm *nvdimm = to_nvdimm(dev);
+
+       set_bit(NDD_LOCKED, &nvdimm->flags);
 }
 
 static void nvdimm_release(struct device *dev)
 
                 * being activated if it aliases DPA.
                 */
                if (!ndd) {
-                       if ((nvdimm->flags & NDD_ALIASING) == 0)
+                       if (!test_bit(NDD_ALIASING, &nvdimm->flags))
                                return 0;
                        dev_dbg(&nd_region->dev, "%s: is disabled, failing probe\n",
                                        dev_name(&nd_mapping->nvdimm->dev));
 
 long nvdimm_clear_poison(struct device *dev, phys_addr_t phys,
                unsigned int len);
 void nvdimm_set_aliasing(struct device *dev);
+void nvdimm_set_locked(struct device *dev);
 struct nd_btt *to_nd_btt(struct device *dev);
 
 struct nd_gen_sb {
 
                        struct nd_mapping *nd_mapping = &nd_region->mapping[i];
                        struct nvdimm *nvdimm = nd_mapping->nvdimm;
 
-                       if (nvdimm->flags & NDD_ALIASING)
+                       if (test_bit(NDD_ALIASING, &nvdimm->flags))
                                alias++;
                }
                if (alias)
                        return NULL;
                }
 
-               if (nvdimm->flags & NDD_UNARMED)
+               if (test_bit(NDD_UNARMED, &nvdimm->flags))
                        ro = 1;
        }
 
 
 
 enum {
        /* when a dimm supports both PMEM and BLK access a label is required */
-       NDD_ALIASING = 1 << 0,
+       NDD_ALIASING = 0,
        /* unarmed memory devices may not persist writes */
-       NDD_UNARMED = 1 << 1,
+       NDD_UNARMED = 1,
+       /* locked memory devices should not be accessed */
+       NDD_LOCKED = 2,
 
        /* need to set a limit somewhere, but yes, this is likely overkill */
        ND_IOCTL_MAX_BUFLEN = SZ_4M,