Patent ID: 8914812

Claim:
A computer program product for facilitating access to input/output (I/O) devices of a computing environment, the computer program product comprising: a non-transitory computer readable storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising: processing, by an application program interface executing on a processor of a first computer system operating according to a first system architecture, an I/O operation requested by an application of the first computer system to access an I/O device operating according to a second system architecture, the second system architecture different from the first system architecture, wherein the first system architecture has a first machine instruction set different from a second machine instruction set of the second system architecture, said processing providing an I/O request, and wherein the application program interface executing on the processor of the first computer system operating according to the first system architecture includes one or more library functions to implement functionality of one or more I/O instructions of the second system architecture to provide access to the I/O device; wherein, based on invoking the one or more library functions of the application program interface, the application program interface provides information about the I/O operation to a subsystem operating according to the second system architecture to access the I/O device operating according to the second system architecture, and wherein the method further comprises accessing the I/O device by the subsystem, wherein the subsystem comprises a channel subsystem executing an instruction set of the second system architecture; and obtaining by the application program interface an interrupt for the I/O device accessed based on the I/O request, the interrupt to indicate completion of the I/O operation.