PCIe TLP size and alignment management
A data storage device includes a memory device and a controller coupled to the memory device. The controller is configured to issue an unaligned transaction, determine that there is a transfer failure indication for the unaligned transaction, and retry the unaligned transaction with either a different alignment or a different transfer size. The different alignment or the different transfer size is used for another unaligned transaction from a same address range upon successful retry of the unaligned transaction.
1. A data storage device, comprising:
a memory device; and
a controller coupled to the memory device, the controller configured to:
issue an unaligned transaction;
determine that there is a transfer failure indication for the unaligned transaction; and
retry the unaligned transaction with either a different alignment or a different transfer size, wherein the controller is further configure to use the different alignment or the different transfer size for another unaligned transaction from a same address range upon successful retry of the unaligned transaction.
2. The data storage device of claim 1 , wherein the controller is further configured to scan a host address grouping table before issuing the unaligned transaction.
3. The data storage device of claim 2 , wherein the controller is further configured to determine that there is an entry corresponding to the unaligned transaction in the host address grouping table.
4. The data storage device of claim 3 , wherein the controller is further configured to, when the entry corresponding to the unaligned transaction is present, either:
issue an aligned transaction; or
issue an unaligned transaction.
5. The data storage device of claim 4 , wherein the issued transaction is issued as specified in the host address grouping table.
6. The data storage device of claim 3 , wherein the controller is further configured to, when the entry corresponding to the unaligned transaction is not present, issue an unaligned transaction.
7. The data storage device of claim 1 , wherein the controller is further configured to determine that there is a second transfer failure indication for the unaligned transaction with either the different alignment or the different transfer size.
8. The data storage device of claim 7 , wherein the controller is further configured to execute error correction function on the unaligned transaction.
9. The data storage device of claim 1 , wherein the controller is further configured to determine that there is not a second transfer failure indication for the unaligned transaction with either the different alignment or the different transfer size.
10. The data storage device of claim 9 , wherein the controller is further configured to update a host address grouping table with the different alignment or the different transfer size for a same address.
11. The data storage device of claim 10 , wherein the controller is further configured to process the unaligned transaction with the different alignment or the different transfer size.
12. The data storage device of claim 1 ,
wherein the controller comprises:
a host interface module, wherein the host interface module comprises a host address grouping table and alignment logic;
a command scheduler;
one or more processors; and
a flash interface module.
13. The data storage device of claim 12 , wherein the host address grouping table comprises one or more entries, and wherein each entry of the one or more entries corresponds to an alignment or a transfer size for an unaligned transaction.
14. The data storage device of claim 12 , wherein the controller is operable according to CXL protocol.
15. The data storage device of claim 12 , wherein the alignment logic determines a different alignment or a different transfer size for an unaligned transaction.
16. The data storage device of claim 12 , wherein the controller is configured to access the host address grouping table upon determining that either:
a first address in a physical region page (PRP) list is misaligned;
a fetched logical to physical (L2P) entry or cache line from an host memory buffer is misaligned; or
an issued transaction is less than a maximum transfer layer packet (TLP) size.
17. The data storage device of claim 1 ,
wherein the controller is further configured to:
determine that an issued transaction is unaligned;
adjust either an alignment or a transfer size of the issued transaction;
determine if the adjusting is successful; and
process the adjusted issued transaction upon determining that the adjusting is successful.
18. The data storage device of claim 17 , wherein the controller is further configured to:
check a host address grouping table upon determining that the issued transaction is unaligned; and
update the host address grouping table based on determining that the adjusting is successful.
19. The data storage device of claim 17 , wherein the controller is further configured to check the issued transaction for a transfer failure indication two or more times.
20. The data storage device of claim 1 , wherein the controller is configured to issue an aligned transaction by reading more data.