Abstract: A computer program product is provided for performing: obtaining, by a channel subsystem, a transport command word (TCW) specified by an operating system, the TCW comprising an address of a transport services request block (TSRQB) and an address of a transport services response block (TSRSB); obtaining the TSRQB; building at least one command request based on the TSRQB, and sending the at least one command request from the channel subsystem to at least one network entity, the at least one command request including at least one of a fibre-channel generic services (FC-GS) request, a fibre-channel link services (FC-LS) request, and a fibre-channel link-level function (FC-SB) request; receiving a response to the at least one command request from the at least one network entity; and storing the response to the TSRSB based on the address of the TSRSB obtained from the TCW.

Abstract: Systems, methods and computer program products for providing indirect data addressing at an I/O subsystem of an I/O processing system. The computer program product includes a tangible storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method. The method includes receiving a control word for an I/O operation. The control word includes an indirect data address for data associated with the I/O operation. The indirect data address includes a starting location of a list of storage addresses that collectively specify the data, the list spans two or more non-contiguous storage locations. Data is gathered responsive to the list. The gathered data is transmitted to a control unit in the I/O processing system.

Abstract: A computer program product is provided for performing input/output (I/O) processing at a host computer system. The computer program product is configured to perform: generating an address control structure for each of a plurality of consecutive data transfer requests specified by an I/O operation, each address control structure specifying a location in the local channel memory of a corresponding address control word (ACW) that includes an Offset field indicating a relative order of a data transfer request; generating and storing in local channel memory at least one ACW specifying one or more host memory locations for the plurality of consecutive data transfer requests and including an Expected Offset field indicating a relative order of an expected data transfer request; receiving a transfer request from the network interface and comparing the Offset field and the Expected Offset field to determine whether the data transfer request has been received in the correct order.

Abstract: A computer program product is provided for performing a method including: obtaining information relating to an I/O operation at a channel subsystem in a host computer system; generating at least one address control word (ACW) in the local channel memory specifying one or more host memory locations for transfer of data between the host and a control unit and including at least one ACW error checking field; generating an address control structure specifying a location in the local channel memory of a corresponding ACW and including at least one address control structure error checking field; receiving a data transfer request from the network interface that includes the addressing information; comparing the at least one ACW error checking field to the at least one address control structure error checking field; and, responsive to the fields matching, routing the data transfer request to the host memory location specified in the corresponding ACW.

Abstract: A computer program product is configured for performing a method including: generating at least one command message by a channel subsystem of the host computer system, the at least one command message including one or more device command words (DCWs), wherein at least one DCW of the one or more DCWs includes a suppress-length indication (SLI) configured to instruct a control unit to continue to perform the I/O operation in response to the control unit detecting that the data count does not match an amount of data required; receiving an incorrect length (IL) value, the IL value being a first IL value in response to the SLI being a first SLI value and the data count not matching the amount of data required; and responsive to receiving the IL value from the control unit, storing an IL indicator in a subchannel-status word.

Abstract: A computer program product is configured for performing a method including: receiving at least one command message specifying an I/O operation at a control unit from a channel subsystem, the at least one command message including one or more device command words (DCWs) having a data count and a suppress-length indication (SLI), the SLI configured to instruct the control unit whether to continue to perform the I/O operation in response to the control unit detecting an incorrect length condition; processing at least one of the one or more DCWs; and returning a transport response message including an incorrect length (IL) value, the IL value being a first IL value in response to the SLI being a first SLI value and the data count not matching the amount of data required, the IL value being a second IL value in response to the SLI being a second SLI value and the data count not matching the amount of data required.

Abstract: A computer program product is provided for performing an input/output (I/O) processing operation at a host computer system. The computer program product is configured to perform: obtaining a transport command word (TCW) at a channel subsystem for an I/O operation, the TCW including an address of a transport command control block (TCCB) having a transport command area (TCA) configured to hold a first plurality of device command words (DCW) and control data associated with respective DCWs, the first plurality of DCWs including a transfer TCA extension (TTE) DCW that specifies a TCA extension, the TCA extension configured to hold one or more DCWs and control data associated with respective DCWs; gathering the TCCB from one or more locations specified in the TCCB address and transferring the TCCB to the control unit; gathering the TCA extension specified by the TTE DCW; and transferring the TCA extension to the control unit.

Abstract: A computer program product is configured for performing a method including: receiving at least one command message specifying an I/O operation at a control unit from a channel subsystem, the at least one command message including one or more device command words (DCWs) having a data count and a suppress-length indication (SLI), the SLI configured to instruct the control unit whether to continue to perform the I/O operation in response to the control unit detecting an incorrect length condition; processing at least one of the one or more DCWs; and returning a transport response message including an incorrect length (IL) value, the IL value being a first IL value in response to the SLI being a first SLI value and the data count not matching the amount of data required, the IL value being a second IL value in response to the SLI being a second SLI value and the data count not matching the amount of data required.

Abstract: A computer program product for procuring information from entities in a network via an Input/Output (I/O) processing system includes a tangible storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method. The method includes receiving, at a channel subsystem, at least one network topology information request from an operating system. The method also includes building at least one command request that includes the at least one network topology information request, and sending the at least one command request from the channel subsystem to at least one network entity. The method further includes receiving a response to the at least one command request from the at least one network entity by the channel subsystem, and forwarding the response from the channel subsystem to the operating system.

Abstract: A computer program product for performing input/output (I/O) processing is provided. The computer program product is configured to perform: obtaining information relating to an I/O operation at a channel subsystem; generating and storing in local channel memory at least one address control word (ACW) specifying one or more host memory locations for data transfer and including a data check word generation field and/or a data check word save field; responsive to receiving an input data transfer request including at least one data check word, storing the at least one data check word in the data check word save field and performing a check of the data to determine whether the data has been corrupted; and responsive to receiving an output data transfer, generating at least one data check word based on the data check word generation field and appending the at least one data check word to the data.

Abstract: Processing of out-of-order data transfers is facilitated in computing environments that enable data to be directly transferred between a host bus adapter (or other adapter) and a system without first staging the data in hardware disposed between the host bus adapter and the system. An address to be used in the data transfer is determined, in real-time, by efficiently locating an entry in an address data structure that includes the address to be used in the data transfer.

Abstract: A computer program product is provided for performing input/output (I/O) processing at a host computer system. The computer program product is configured to perform: generating an address control structure for each of a plurality of consecutive data transfer requests specified by an I/O operation, each address control structure specifying a location in the local channel memory of a corresponding address control word (ACW) that includes an Offset field indicating a relative order of a data transfer request; generating and storing in local channel memory at least one ACW specifying one or more host memory locations for the plurality of consecutive data transfer requests and including an Expected Offset field indicating a relative order of an expected data transfer request; receiving a transfer request from the network interface and comparing the Offset field and the Expected Offset field to determine whether the data transfer request has been received in the correct order.

Abstract: A computer program product for performing input/output (I/O) processing is configured for performing a method including: obtaining information relating to an I/O operation at a channel subsystem; generating and storing in local channel memory at least one address control word (ACW) specifying one or more host memory locations for data transfer and including a field for storing header information; generating an address control structure specifying a location in the local channel memory of a corresponding ACW; receiving a data transfer request from a network interface that includes the address control structure; responsive to an input data request, routing the data to at least one host memory location specified by the corresponding ACW and storing header information in the corresponding ACW; and responsive to an output data request, routing the data from a host memory location specified by the ACW to the network interface and appending header information to the data.

Abstract: A method of performing an input/output (I/O) processing operation includes: generating an address control structure for each of a plurality of consecutive data transfer requests, each address control structure specifying a local channel memory location of a corresponding address control word (ACW); receiving a data transfer request from a network interface that includes addressing information specified by a corresponding address control structure; comparing, by a data router in the channel, an Offset field of an address control structure and an Expected Offset field of an ACW to determine whether the data transfer request has been received in the correct order; and based on determining that the data transfer request has been received in the correct order, accessing the ACW by the data router and routing the data transfer request to a host memory location specified in the ACW.

Abstract: A computer program product is provided for performing a method including: obtaining information relating to an I/O operation at a channel subsystem in a host computer system; generating at least one address control word (ACW) in the local channel memory specifying one or more host memory locations for transfer of data between the host and a control unit and including at least one ACW error checking field; generating an address control structure specifying a location in the local channel memory of a corresponding ACW and including at least one address control structure error checking field; receiving a data transfer request from the network interface that includes the addressing information; comparing the at least one ACW error checking field to the at least one address control structure error checking field; and, responsive to the fields matching, routing the data transfer request to the host memory location specified in the corresponding ACW.

Abstract: On embodiment includes a computer program product for performing a method including: obtaining information relating to an I/O operation at a channel subsystem in a host computer system; generating addressing information and forwarding the addressing information from at least one channel to a network interface between the channel subsystem and at least one I/O device, the addressing information specifying a location in a local channel memory; 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; responsive to receiving the data transfer request, accessing one of a plurality of address control words (ACWs), each ACW specifying an address of a location in a host computer memory; and routing the data transfer request to the host memory location specified in the ACW.

Abstract: Processing of out-of-order data transfers is facilitated in computing environments that enable data to be directly transferred between a host bus adapter (or other adapter) and a system without first staging the data in hardware disposed between the host bus adapter and the system. An address to be used in the data transfer is determined, in real-time, by efficiently locating an entry in an address data structure that includes the address to be used in the data transfer.

Abstract: A computer program product is provided for performing input/output (I/O) processing. The computer program product is configured to perform: generating and storing in local channel memory at least one address control word (ACW) specifying one or more host memory locations for data transfer and including a data discard field; generating an address control structure specifying a local channel memory location of a corresponding ACW; receiving one or more data transfer requests from a network interface that each corresponding address control structure information; accessing an ACW and routing the data transfer request to a host memory location specified in the ACW; and responsive to encountering an error during at least one of the accessing and the routing, discarding the one or more data transfer requests and setting the data discard field to a value configured to instruct a channel to discard any subsequent data transfer requests associated with the ACW.

Abstract: A computer program product, an apparatus, and a method for processing communications between a control unit and a channel subsystem in an input/output processing system are provided. The computer program product includes a tangible storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method. The method includes: sending a command from the channel subsystem to the control unit to initiate an input/output operation; setting a time period for completion of the operation; and responsive to the operation not completing within the time period, sending a message to determine whether the control unit has an exchange open for the command.

Abstract: A computer program product is provided for performing: sending, by a channel subsystem, a process login (PRLI) request message to the control unit that indicates whether the channel subsystem supports bi-directional data transfer; receiving a PRLI response message from the control unit that indicates whether the control unit supports bi-directional data transfer; gathering a plurality of commands, at least one which specifies an input data transfer and at least one specifying an output data transfer; sending at least one output data message to the control unit including output data to be transferred to the control unit, the output data message associated with the at least one of the plurality of commands specifying an output data transfer; and receiving at least one input message from the control unit including input data to be stored in a main storage of the host computer system.