Non-volatile storage controller with partial logical-to-physical (L2P) address translation table

An apparatus, comprising:

• a processor, and
• a logical-to-physical (L2P) translation engine comprising a cache of lookup directory entries of recently accessed translation data units (TDUs) and a miss buffer, the L2P translation engine configured to:
• receive a request for a first logical data address (LDA) from the processor;
• calculate a first TDU index for a first TDU, the first TDU containing a L2P entry for the first LDA;
• search the cache of lookup directory entries of recently accessed TDUs using the first TDU index;
• determine that the cache does not have a lookup directory entry for the first TDU;
• generate and store an outstanding request for the lookup directory entry for the first TDU in the miss buffer;
• retrieve the lookup directory entry for the first TDU from an in-memory lookup directory in a memory coupled to the apparatus;
• determine that the lookup directory entry for the first TDU is not valid;
• reserve a TDU space for the first TDU in the memory;
• generate a load request for the first TDU;
• receive a TDU load completion message for the first TDU;
• process the outstanding request for the lookup directory entry for the first TDU in the miss buffer;
• update the lookup directory entry for the first TDU in the in-memory lookup directory with a memory location of the first TDU;
• and
• update the lookup directory entry for the first TDU in the cache of lookup directory entries with the memory location of the first TDU.

A non-transitory machine-readable medium having executable instructions, wherein the executable instructions, when executed by a storage controller, causes the storage controller to:

• receive a request for a first logical data address (LDA);
• calculate a first translation data unit (TDU) index for a first TDU, the first TDU containing a logical-to-physical (L2P) entry for the first LDA;
• search a cache of lookup directory entries of recently accessed TDUs using the first TDU index;
• determine that the cache does not have a lookup directory entry for the first TDU;
• generate and storing an outstanding request for the lookup directory entry for the first TDU in a miss buffer;
• retrieve the lookup directory entry for the first TDU from an in-memory lookup directory in a memory coupled to the storage controller;
• determine that the lookup directory entry for the first TDU is not valid;
• reserve a TDU space for the first TDU in the memory;
• generate a load request for the first TDU;
• receive a TDU load completion message for the first TDU;
• process the outstanding request for the lookup directory entry for the first TDU in the miss buffer;
• update the lookup directory entry for the first TDU in the in-memory lookup directory with a memory location of the first TDU;
• and
• update the lookup directory entry for the first TDU in the cache of lookup directory entries with the memory location of the first TDU.