A processor-cache operational scheme and topology within a multi-processor data processing system having a shared lower level cache (or memory) by which the number of coherency busses is reduced and more efficient snoop resolution and coherency operations with the processor caches are provided. A copy of the internal (L1) cache directory is provided within the lower level (L2) cache or memory. The snoop operations and coherency maintenance operations of the L1 directory are completed by comparing the snoop addresses with the address tags of the copy of the L1 directory in the L2 cache. Updates to the coherency states of the copy of the L1 directory are mirrored in the L1 directory and L1 cache. This eliminates the need for the individual coherency buses of each processor that is coupled to the L2 cache and speeds up coherency operations because the snoops do not have to be transmitted to the L1 caches.