ND_REGION_PERSIST_CACHE
set_bit(ND_REGION_PERSIST_CACHE, &ndr_desc->flags);
!test_bit(ND_REGION_PERSIST_CACHE, &nd_region->flags);
if (test_bit(ND_REGION_PERSIST_CACHE, &nd_region->flags))
if ((nd_region->flags & (BIT(ND_REGION_PERSIST_CACHE)