Providing indirect data addressing for a control block at a channel subsystem of an I/O processing system
First Claim
1. A computer program product 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 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 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 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
forwarding the message to the control unit for execution.
1 Assignment
0 Petitions
Accused Products
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.
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Citations
20 Claims
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1. A computer program product 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 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 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 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
forwarding the message to the control unit for execution. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
- 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;
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10. An apparatus for providing indirect data addressing for a control block at a host computer system configured for communication with a control unit, the host computer system performing:
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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 the one or more I/O commands; gathering the one or more I/O commands from a plurality of storage 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. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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17. A method for providing indirect data addressing for a control block at a host computer system, the host computer system including a channel subsystem configured for communication with a control unit, the method comprising:
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obtaining a transport command word (TCW) for an I/O operation by the channel subsystem, 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 the one or more I/O commands; gathering the one or more I/O commands from a plurality of storage 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. - View Dependent Claims (18, 19, 20)
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Specification