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 fiber-channel generic services (FC-GS) request, a fiber-channel link services (FC-LS) request, and a fiber-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: Optimizations are provided for frame management operations, including a clear operation and/or a set storage key operation, requested by pageable guests. The operations are performed, absent host intervention, on frames not resident in host memory. The operations may be specified in an instruction issued by the pageable guests.

Abstract: A computer program product for processing input/output (I/O) data is provided for performing a method, which includes receiving a control word having an indirect data address including a starting location of a list of storage addresses, gathering the data and transmitting gathered data to a control unit in the I/O processing system. Gathering includes accessing an entry of the list, the entry located at an entry storage location and including an address. Based on the entry of the list indicating that the address is a data address, data is gathered from a data storage location, and a next entry of the list is accessed. Based on the entry of the list indicating that the address is an address of a next entry of the list, the next entry of the list is obtained from another storage location that is located non-contiguously to the entry storage location.

Abstract: Optimizations are provided for frame management operations, including a clear operation and/or a set storage key operation, requested by pageable guests. The operations are performed, absent host intervention, on frames not resident in host memory. The operations may be specified in an instruction issued by the pageable guests.

Abstract: A computer program product is provided for performing an input/output (I/O) operation initiated by an I/O operation instruction at a host computer system configured for communication with a control unit. 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: receiving, by the control unit, a transport mode command message from a channel subsystem of the host computer system, the command message include a command for data to be transferred between the host computer system and an I/O device controlled by the control unit; and sending a command retry message to the channel subsystem, the command retry message including a request that the command message be re-sent to the control unit and a reason code indicating a reason for the request.

Abstract: What is disclosed is a frame management function defined for a machine architecture of a computer system. In one embodiment, a frame management instruction is obtained which identifies a first and second general register. The first general register contains a frame management field having a key field with access-protection bits and a block-size indication. If the block-size indication indicates a large block then an operand address of a large block of data is obtained from the second general register. The large block of data has a plurality of small blocks each of which is associated with a corresponding storage key having a plurality of storage key access-protection bits. If the block size indication indicates a large block, the storage key access-protection bits of each corresponding storage key of each small block within the large block is set with the access-protection bits of the key field.

Abstract: A computer program product, apparatus, and a method for facilitating input/output (I/O) processing for an I/O operation at a host computer system configured for communication with a control unit. The method includes receiving a command block from the channel subsystem, the command block including at least one input command and at least one output command specified by a transport command word (TCW) and associated with the I/O operation, the I/O operation having both input and output data, the TCW specifying a location in the memory of the output data and a location in the memory for storing the input data; receiving the output data specified by the TCW and executing the at least one output command; and forwarding the input data specified by the TCW to the channel subsystem for storage at a location specified by the TCW.

Abstract: An computer program product, apparatus, and method for facilitating input/output (I/O) processing for an I/O operation at a host computer system configured for communication with a control unit. The computer program product is provided for performing a method including: sending a transport command word (TCW) to an I/O subsystem, the TCW specifying a location address and indicating whether the TCW directly or indirectly addresses a message; extracting the location address from the TCW; obtaining the message from the specified location address based on the TCW indicating direct addressing, the message including the one or more I/O commands; gathering the one or more I/O commands from command locations specified by a list of addresses identified by the specified location address to form the message based on the TCW indicating indirect addressing; and generating a message including the one or more I/O commands.

Abstract: Processing within a computing environment that supports pageable guests is facilitated. Processing is facilitated in many ways, including, but not limited to, associating guest and host state information with guest blocks of storage; maintaining the state information in control blocks in host memory; enabling the changing of states; and using the state information in management decisions. In one particular example, the guest state includes an indication of usefulness and importance of memory contents to the guest, and the host state reflects the ease of access to memory contents. The host and guest state information is used in managing memory of the host and/or guests.

Abstract: A computer program product is provided for performing an input/output (I/O) operation initiated by an I/O operation instruction at a host computer system configured for communication with a control unit. 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: receiving, by the control unit, a transport mode command message from a channel subsystem of the host computer system, the command message include a command for data to be transferred between the host computer system and an I/O device controlled by the control unit; and sending a command retry message to the channel subsystem, the command retry message including a request that the command message be re-sent to the control unit and a reason code indicating a reason for the request.

Abstract: Host page management assist functions are employed to manage storage of a pageable mode virtual environment. These functions enable storage to be managed by a processor of the environment absent intervention of a host of the environment. The functions include a resolve host page function; a pin function; and unpin functions.

Abstract: An computer program product, apparatus, and method for facilitating input/output (I/O) processing for an I/O operation at a host computer system configured for communication with a control unit. The computer program product is provided for performing a method including: obtaining a transport command word (TCW) for an I/O operation, the TCW specifying a location address and indicating whether the TCW directly or indirectly addresses a message for transmitting one or more commands to the control unit; extracting the specified location address from the TCW; obtaining the message from the specified location address based on the TCW indicating direct addressing, the message including one or more I/O commands; gathering one or more I/O commands from command locations specified by a list of addresses identified by the specified location address to form the message based on the TCW indicating indirect addressing; and forwarding the message to the control unit for execution.

Abstract: Automatically converting a synchronous data transfer to an asynchronous data transfer. Data to be transferred from a sender to a receiver is initiated using a synchronous data transfer protocol. Responsive to a determination that the data is to be sent asynchronously, the data transfer is automatically converted from the synchronous data transfer to the asynchronous data transfer.

Abstract: Executing a Next Instruction Access Intent instruction by a computer. The processor obtains an access intent instruction indicating an access intent. The access intent is associated with an operand of a next sequential instruction. The access intent indicates usage of the operand by one or more instructions subsequent to the next sequential instruction. The computer executes the access intent instruction. The computer obtains the next sequential instruction. The computer executes the next sequential instruction, which comprises based on the access intent, adjusting one or more cache behaviors for the operand of the next sequential instruction.

Abstract: Optimizations are provided for frame management operations, including a clear operation and/or a set storage key operation, requested by pageable guests. The operations are performed, absent host intervention, on frames not resident in host memory. The operations may be specified in an instruction issued by the pageable guests.

Abstract: An instruction is provided that includes an opcode field to identify a store instruction to store in a designated location current values of operational parameters of an adapter function of an adapter; a first field to identify a location, the contents of which include a function handle identifying a handle of the adapter function for which the store instruction is being performed, and an indication of an address space associated with the adapter function identified by the function handle to which the store instruction applies; and a second field to identify the designated location of where a result of the store instruction is to be stored. Execution of the instruction includes obtaining information from a function information block associated with the adapter function; and copying the information from the function information block into the designated location, based on completion of one or more validity checks with one or more predefined results.

Abstract: What is provided is a load page table entry address function defined for a machine architecture of a computer system. In one embodiment, a machine instruction is obtained which contains an opcode indicating that a load page table entry address function is to be performed. The machine instruction contains an M field, a first field identifying a first general register, and a second field identifying a second general register. Based on the contents of the M field, an initial origin address of a hierarchy of address translation tables having at least one segment table is obtained. Based on the obtained initial origin address, dynamic address translation is performed until a page table entry is obtained. The page table entry address is saved in the identified first general register.

Abstract: What is provided is a load page table entry address function defined for a machine architecture of a computer system. In one embodiment, a machine instruction is obtained which contains an opcode indicating that a load page table entry address function is to be performed. The machine instruction contains an M field, a first field identifying a first general register, and a second field identifying a second general register. Based on the contents of the M field, an initial origin address of a hierarchy of address translation tables having at least one segment table is obtained. Based on the obtained initial origin address, dynamic address translation is performed until a page table entry is obtained. The page table entry address is saved in the identified first general register.

Abstract: An instruction is provided to establish various operational parameters for an adapter. These parameters include adapter interruption parameters, input/output address translation parameters, resetting error indications, setting measurement parameters, and setting an interception control, as examples. The instruction specifies a function information block, which is a program representation of a device table entry used by the adapter, to be used in certain situations in establishing the parameters. A store instruction is also provided that stores the current contents of the function information block.

Abstract: An computer program product, apparatus, and method for facilitating input/output (I/O) processing for an I/O operation at a host computer system configured for communication with a control unit. The computer program product is provided for performing a method including: obtaining a transport command word (TCW) for an I/O operation, the TCW specifying a location address and indicating whether the TCW directly or indirectly addresses a message for transmitting one or more commands to the control unit; extracting the specified location address from the TCW; obtaining the message from the specified location address based on the TCW indicating direct addressing, the message including one or more I/O commands; gathering one or more I/O commands from command locations specified by a list of addresses identified by the specified location address to form the message based on the TCW indicating indirect addressing; and forwarding the message to the control unit for execution.