摘要:
A computer program product, apparatus, and method are provided for determining a state of an input/output (I/O) operation in an I/O processing system. A request from a channel subsystem is received at a control unit for performing the I/O operation. After a predetermined amount of time passes without the I/O operation completing, an interrogation request is received from the channel subsystem at the control unit for determining the state of the I/O operation. A response is sent from the control unit to the channel subsystem indicating the state of the I/O operation in response to the interrogation request. The response also includes information regarding a state of an I/O device executing the I/O operation and information indicating a state of the control unit controlling the I/O device executing the I/O operation.
摘要:
An article of manufacture, an apparatus, and a method for determining an extended measurement word at a channel subsystem of an I/O processing system using data from a control unit are provided. The article of manufacture includes at least one computer usable medium having computer readable program code logic. The computer readable program code logic performs a method including sending a command message to the control unit, and receiving a transport response information unit message at the channel subsystem in response to sending the command message to the control unit. The computer readable program code logic additionally extracts a plurality of time values from the transport response information unit message as calculated by the control unit, calculates an extended measurement word as a function of the time values, and writes the extended measurement word to computer readable memory in the I/O processing system.
摘要:
The state of an input/output (I/O) operation is determined in an I/O processing system. A command is received from an I/O operating system at a channel subsystem for initiating the I/O operation, a time period is for completion of the I/O operation, and the command for initiating the I/O operation is sent from the channel subsystem to the control unit. Responsive to the time period nearing elapsing without the I/O operation completing, a cancel instruction is received from the I/O operating system at the channel subsystem. Responsive to a determination by the I/O operating system to interrogate the control unit, an instruction to interrogate the control unit is received with the cancel instruction from the I/O operating system.
摘要:
Input/output processing is facilitated by reducing communications between input/output communications adapters and control units during input/output processing. The number of exchanges and sequences between an input/output communications adapter and control unit is reduced by sending a plurality of commands from the adapter to the control unit as a single entity for execution by the control unit. The control unit executes the commands and provides the data, if any, in one sequence. The control unit relieves the adapter of the responsibility of tracking state of the individual commands and is able to calculate precise measurement data relating to execution of the commands.
摘要:
A data communication architecture including a plurality of devices having input/output (I/O) ports supporting communication at a first rate and a data processor having a number of I/O ports where each I/O port supports data communication at a second data rate. The second data rate is at least double the first data rate. A communication link coupled to one of the data processor I/O ports supports the second data rate. A bridge device is coupled to the communication link and to the I/O ports of the plurality of devices. The bridge device translates the communication link at the second data rate to a plurality of communication links at the first data rate, where the plurality of communication links at the first data rate are substantially independent of each other.
摘要:
An outbound frame state machine (OFSM) which generates data frames for transmission over a data link. The OFSM is microcode controlled and includes an outbound frame header buffer for containing information to be included in the header of the frame, a data buffer for storing data characters to be included in the data frame, a data generator register for providing special sequences of data characters, if required, and an outbound frame trace buffer for storing a trace log of all frames transmitted in the normal mode and to be used if the OFSM is operating in the simulated I/O mode or the diagnostic mode. In the normal mode of operation, the OFSM builds a data frame using header information from the frame heater bufferm and may include data from the data buffer, all as specified by control bits stored in a control register. The control register may also include a bit for causing special sequences to be transmitted. In the simulation mode, frames are built by the OFSM and then wrapped back to the channel to be processed like frames from a control unit. In the diagnostic mode, the OFSM inserts various characters into the outbound data bit stream to create possible error situations on the data link.
摘要:
An apparatus for decoding frames from a data link including a multiple entry expect/mask buffer an input for receiving multiple character frames, a comparator for comparing characters received from the data link with expected characters in the expect/mask buffer as masked by a mask also in the expect/mask buffer, a multiple entry header buffer for storing characters of frames received by the input, and a multiple entry compare buffer for storing in an entry the results of the comparison of the characters stored in the corresponding entry in the header buffer to expected characters as masked by the mask in a corresponding entry of the expect/mask buffer. Storage into the header buffer and the compare buffer is stopped by terminating events which are detected by a state machine. A data frame recognition circuit is provided which detects a variety of data frames from among the frames transmitted over the data link to the input of the apparatus.
摘要:
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.
摘要:
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.
摘要:
An article of manufacture, 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 the host computer system obtaining a transport command word (TCW) for an I/O operation having both input and output data. The TCW specifies a location of the output data and a location for storing the input data. The host computer system forwards the I/O operation to the control unit for execution. The host computer system gathers the output data responsive to the location of the output data specified by the TCW, and then forwards the output data to the control unit for use in the execution of the I/O operation. The host computer system receives the input data from the control unit and stores the input data at the location specified by the TCW.