Exception condition handling at a channel subsystem in an I/O processing system
First Claim
1. A computer program product for handling exception condition feedback at a channel subsystem of an input/output (I/O) processing system using data from a control unit, the channel subsystem configured to send command messages of a corresponding Transport control Word (TCW) channel program and performing I/O operations, the computer program product comprising:
- a tangible storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising;
sending a command message to the control unit for an I/O operation to be performed;
responsive to the sent command message specifying a write operation, sending data for the write operation to the control unit;
receiving a response message in response to the command message, the response message comprising device requested program check information resulting from a TCW channel program error detected by the control unit and a termination reason code, the device requested program check information comprising a device requested program check indication, the device requested program check information for identifying control unit detected channel program errors related to the sent command message or the sent data of the write operation;
interrupting a central processing unit (CPU) in the I/O processing system; and
reporting status associated with the device requested program check information of the received response message to the CPU in an interrupt response block comprising a status flag field having a device requested program check code for indicating whether the device requested program check indication was received.
2 Assignments
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Accused Products
Abstract
A computer program product, apparatus, and method for handling exception condition feedback at a channel subsystem of an I/O processing system using data from a control unit 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 message to the control unit, and receiving a response message in response to the command message. The response message includes exception condition feedback identifying a termination reason code in response to unsuccessful execution of at least one command in the command message. The method also includes interrupting a CPU in the I/O processing system, and reporting status associated with the exception condition feedback to the CPU in an interrupt response block.
153 Citations
31 Claims
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1. A computer program product for handling exception condition feedback at a channel subsystem of an input/output (I/O) processing system using data from a control unit, the channel subsystem configured to send command messages of a corresponding Transport control Word (TCW) channel program and performing I/O operations, the computer program product comprising:
a tangible storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising; sending a command message to the control unit for an I/O operation to be performed; responsive to the sent command message specifying a write operation, sending data for the write operation to the control unit; receiving a response message in response to the command message, the response message comprising device requested program check information resulting from a TCW channel program error detected by the control unit and a termination reason code, the device requested program check information comprising a device requested program check indication, the device requested program check information for identifying control unit detected channel program errors related to the sent command message or the sent data of the write operation; interrupting a central processing unit (CPU) in the I/O processing system; and reporting status associated with the device requested program check information of the received response message to the CPU in an interrupt response block comprising a status flag field having a device requested program check code for indicating whether the device requested program check indication was received. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 26, 27)
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11. An apparatus for handling exception condition feedback in an input/output ((I/O)) processing system, the apparatus comprising:
a channel subsystem in communication with a control unit, the channel subsystem configured to send command messages of a corresponding Transport control word (TCW) channel program and performing (I/O) operations, the channel subsystem configured to perform a method comprising; sending a command message to the control unit for an (I/O) operation to be performed; responsive to the sent command message specifying a write operation, sending data for the write operation to the control unit; receiving a response message in response to the command message, the response message comprising device requested program check information resulting from a TCW channel program error detected by the control unit and a termination reason code, the device requested program check information comprising a device requested program check indication, the device requested program check information for identifying control unit detected channel program errors related to the sent command message or the sent data of the write operation; interrupting a central processing unit (CPU) in the I/O processing system; and reporting status associated with the device requested program check information of the received response message to the CPU in an interrupt response block comprising a status flag field having a device requested program check code for indicating whether the device requested program check indication was received. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 28, 29)
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21. A method for handling exception condition feedback at a channel subsystem of an input/output (I/O) processing system using data from a control unit, the channel subsystem configured to send command messages of a corresponding Transport control word (TCW) channel program and performing I/O operations, the method comprising:
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sending a command message to the control unit for an I/O operation to be performed; responsive to the sent command message specifying a write operation, sending data for the write operation to the control unit; receiving a response message in response to the command message, the response message comprising device requested program check information resulting from a TCW channel program error detected by the control unit and a termination reason code, the device requested program check information comprising a device requested program check indication, the device requested program check information for identifying control unit detected channel program errors related to the sent command message or the sent data of the write operation; interrupting a central processing unit (CPU) in the (I/O) processing system; and reporting status associated with the device requested program check information of the received response message to the CPU in an interrupt response block comprising a status flag field having a device requested program check code for indicating whether the device requested program check indication was received. - View Dependent Claims (22, 23, 24, 25, 30, 31)
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Specification