Patent ID: 7886086
Filing Date: 2011-02-08
Classification: G06F

Abstract:
1. A method in a data processing system to restrict input/output peer-to-peer operations between a plurality of peer-to-peer devices that are each operably coupled together by one of a switch and bridge (switch/bridge), wherein the switch/bridge has a primary input/output bus operably coupled to an upstream switch/bridge and a plurality of downstream secondary input/output buses each operably coupled to a given peer device of the plurality of peer-to-peer devices, the method comprising: detecting an input/output operation request on a given secondary input/output bus of the plurality of downstream secondary input/output buses; responsive to determining that a target of the input/output operation request is a peer device coupled to another downstream secondary input/output bus of the plurality of downstream secondary input/output buses, performing a lookup on a peer-to-peer lookup table comprising a plurality of entries for at least some of the plurality of peer-to-peer devices which are each operably coupled to a respective one of the plurality of downstream secondary input/output buses; determining whether a requester identifier of the input/output operation request matches a corresponding requester identifier of any entry in the plurality of entries; when the requester identifier of the input/output operation request does not match at least one corresponding requester identifier in the plurality of entries, rejecting the input/output operation request targeted for the peer device; when the requester identifier of the input/output operation request matches the requester identifier of an entry in the plurality of entries, determining if an accept/reject bit of the entry is equal to one; and when the accept/reject bit is not equal to one, rejecting the input/output operation request targeted for the peer device.