Patent ID: 8364853
Filing Date: 2013-01-29
Classification: G06F

Abstract:
1. A computer program product for performing an input/output (I/O) processing operation at a host computer system configured for communication with a control unit, the computer program product comprising: a non-transitory tangible storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising: obtaining information relating to an I/O operation at a channel subsystem in the host computer system, the channel subsystem including at least one channel having a channel processor and a local channel memory; generating at least one address control word (ACW) configured to specify one or more host memory locations for transfer of data between the host computer system and the control unit, and storing the at least one ACW in the local channel memory, the at least one ACW including at least one ACW error checking field configured to indicate a local channel memory region to which a data transfer request is to be routed; generating an address control structure for each data transfer specified by the I/O operation and forwarding each address control structure from the at least one channel to a network interface between the channel subsystem and at least one I/O device, each address control structure configured to specify a location in the local channel memory of a corresponding ACW, each address control structure including at least one address control structure error checking field configured to indicate a local channel memory region to which the data transfer request is to be routed; forwarding an I/O command message to the at least one I/O device via the network interface; responsive to the I/O command message, receiving a data transfer request from the network interface that includes the addressing information; comparing, by a data router in the channel, the at least one ACW error checking field to the at least one address control structure error checking field; and responsive to the at least one ACW error checking field matching the at least one address control structure error checking field, accessing the corresponding ACW by the data router and routing the data transfer request to the host memory location specified in the corresponding ACW.