Systems and methods for target mode connection management in SAS connections

A method operable in a SAS controller having at least one SAS protocol link layer processing element and adapted to interface with a SAS protocol transport layer processing element and operating in the role of a SAS target, the method comprising:

• receiving a request from the SAS protocol transport layer processing element to re-establish a connection to a particular SAS initiator device identified in the request by a supplied index value wherein the supplied index value comprises fewer bits than the SAS address in the request;
• accessing a table using the supplied index value to determine the SAS address for the particular SAS initiator device;
• generating an OPEN request to re-establish the requested connection to the particular SAS initiator device wherein the generated OPEN request uses the SAS address determined by access to the table;
• and
• transmitting the generated OPEN request to the particular SAS initiator device.

A SAS controller adapted for performing SAS protocol link layer processing in the role of a SAS target, the controller comprising:

• an interface to a SAS communication physical medium wherein the controller is adapted to receive an OPEN request from the physical medium through the interface to establish a connection to a particular SAS initiator device;
• a table having a plurality of entries each storing SAS connection information for a corresponding SAS device known to the controller;
• and
• a SAS protocol link layer processing element coupled to the interface and coupled to the table wherein the link layer is adapted to use the SAS address of the particular SAS initiator device and the table to access the SAS connection information corresponding to the particular SAS initiator device, and wherein the link layer is adapted to use the SAS connection information to validate the received request.

A method operable in a SAS controller having at least one SAS protocol link layer processing element adapted to interface with a SAS communication medium and operating in the role of a SAS target, the method comprising:

• receiving an OPEN request from the SAS communication medium to establish a connection to a particular SAS initiator device identified in the request by a SAS address in the received OPEN request;
• accessing a table using the SAS address to retrieve SAS connection information for the particular SAS initiator device;
• validating parameters of the received OPEN request based on the retrieved SAS connection information;
• and
• transmitting a response to the SAS communication medium in response to the OPEN request to indicate the validity of the received OPEN request.