Automated transformation from command mode to transport mode
Communicating between a first device and a second device includes the first device generating command mode control words for communication with the second device, the first device converting the command mode control words into transport mode control words prior to transmitting the control words to the second device, the first device receiving transport mode control words from the second device, and the first device converting the transport mode control words received from the second device into received command mode control words. An application running on the first device may generate command mode control words for communication with the second device. The application may directly provide command mode control words to an ssch or channel subsystem layer. The first device may convert the command mode control words into transport mode control words using an ssch or channel subsystem layer. The first device may be a host computing system.
1. A method of communicating between a first device and a second device, comprising:
the first device generating command mode control words for communication with the second device;
the first device converting the command mode control words into transport mode control words prior to transmitting the control words to the second device by waiting to receive a command mode prefix command, receiving additional command mode control words following the command mode prefix command, receiving a final command mode control word, and generating each of the transport mode control words based on the plurality of command mode control words that follow the command mode prefix command;
the first device receiving transport mode control words from the second device; and
the first device converting the transport mode control words received from the second device into received command mode control words.
2. A method, according to claim 1 , wherein an application running on the first device generates command mode control words for communication with the second device.
3. A method, according to claim 2 , wherein the application directly provides command mode control words to one of: an ssch layer or a channel subsystem layer.
4. A method, according to claim 1 , wherein the first device converts the command mode control words into transport mode control words using one of: an ssch layer or a channel subsystem layer.
5. A method, according to claim 1 , wherein the first device is a host computing system.
6. A method, according to claim 1 , wherein the second device is a data storage system.
7. A method, according to claim 1 , further comprising:
the first device determining if the second device accepts transport mode control words.
8. A method, according to claim 7 , wherein the first device checks a flag to determine if the second device accepts transport mode control words.
9. A method, according to claim 8 , wherein the flag is set in response to an inquiry to the second device.
10. A method, according to claim 1 , wherein the first and second devices are coupled using a FICON connection.
11. A non-transitory computer readable medium containing software that provides communication between a first device and a second device, the software comprising:
executable code in the first device that generates command mode control words for communication with the second device;
executable code in the first device that converts the command mode control words into transport mode control words prior to transmitting the control words to the second device by waiting to receive a command mode prefix command, receiving additional command mode control words following the command mode prefix command, receiving a final command mode control word, and generating each of the transport mode control words based on the plurality of command mode control words that follow the command mode prefix command;
executable code in the first device that receives transport mode control words from the second device; and
executable code in the first device that converts the transport mode control words received from the second device into received command mode control words.
12. A non-transitory computer readable medium, according to claim 11 , wherein an application running on the first device generates command mode control words for communication with the second device.
13. A non-transitory computer readable medium, according to claim 12 , wherein the application directly provides command mode control words to one of: an ssch layer or a channel subsystem layer.
14. A non-transitory computer readable medium, according to claim 11 , wherein the first device converts the command mode control words into transport mode control words using one of: an ssch layer or a channel subsystem layer.
15. A non-transitory computer readable medium, according to claim 11 , wherein the first device is a host computing system.
16. A non-transitory computer readable medium, according to claim 11 , wherein the second device is a data storage system.
17. A non-transitory computer readable medium, according to claim 11 , further comprising:
executable code at the first device that determines if the second device accepts transport mode control words.
18. A non-transitory computer readable medium, according to claim 17 , wherein the first device checks a flag to determine if the second device accepts transport mode control words.
19. A non-transitory computer readable medium, according to claim 18 , wherein the flag is set in response to an inquiry to the second device.
20. A non-transitory computer readable medium, according to claim 11 , wherein the first and second devices are coupled using a FICON connection.