Methods and apparatus for injecting pci express traffic into host cache memory using a bit mask in the transaction layer steering tag

A method of injecting PCIe input/output (I/O) traffic into a cache memory hierarchy associated with a root complex, the method comprising:

• receiving, at said root complex, a transaction request message sent from a PCIe endpoint function, said message including a TLP header comprising a processing hint portion and a steering tag portion;
• reading, by said root complex, said steering tag portion to identify processing resource locations within said root complex targeted by said endpoint function;
• and
• filtering, by said root complex, said targeted locations to reduce the number thereof.

A CPU complex configured to communicate with at least one PCIe endpoint function of the type including a requester module configured to implement an open systems interconnect (OSI) protocol stack and configured to send transaction request messages which include a steering tag header embodying information relating to processing resource locations in the CPU complex targeted by the endpoint function, the CPU complex comprising:

• a cache memory hierarchy comprising a plurality of last level cache memory sectors targetable by the at least one endpoint function;
• a receiving module configured to implement an OSI stack, to receive the transaction request messages from the endpoint function, to read the steering tag header, and to apply a bit mask to reconfigure the target processing resource locations communicated by the endpoint function to the CPU complex;
• and
• a memory controller configured to write data associated with one of the transaction request messages to at least one of said last level cache memory sectors in accordance with said reconfigured targeted locations.