Method and device for off-loading message digest calculations

1. A method for off-loading calculation of a data-integrity-checking value for a data message, the method comprising:

providing a generalized interface allowing application programs to request data-integrity-checking value calculations, wherein the interface is independent of the capabilities of the processing elements that perform the calculations;

an application program selecting a data-integrity-checking scheme from a specified set of schemes, wherein each scheme of the specified set of schemes identifies a corresponding data digest type to calculate a data-integrity-checking value;

the application program communicating the data-integrity-checking scheme and the data message to a second program using the generalized interface; and

the second program calculating a data-integrity-checking value according to the data-integrity-checking scheme for the data message.

2. A method according to claim 1 wherein the specified set of schemes includes at least one scheme that employs a cyclic redundancy check and one scheme that employs a checksum.

3. A method according to claim 1 , wherein the specified set of schemes includes at least two schemes, the schemes differing in at least one of a starting place in the message to start computing the data-checking value, a stopping place in the message to stop computing the data-checking value, and a position in the message at which to insert the data-checking value.

4. A method according to claim 1 wherein the second program runs on a host channel adapter.

5. A method according to claim 1 further including:

the second program transmitting the data-integrity-checking value.

6. A method according to claim 5 wherein transmitting the data-integrity-checking value includes transmitting the value to a remote computer system.

7. A method for off-loading calculation of a data-integrity-checking value for a message received at a computer node, the method comprising:

selecting a data-integrity-checking scheme from a specified set of schemes using an application program;

communicating the data-integrity-checking scheme and a message selection criterion to a second program; and

if the message meets the message selection criterion,

calculating a data-integrity-checking value according to the data-integrity-checking scheme for the message using the second program; and

communicating the message and the data-integrity-checking value to the application program.

8. A method according to claim 7 wherein the specified set of schemes includes at least one scheme that employs a cyclic redundancy check and one scheme that employs a checksum.

9. A method according to claim 7 , wherein the specified set of schemes includes at least two schemes, the schemes differing' in at least one of a starting place in the message to start computing the data-checking value, a stopping place in the message to stop computing the data-checking value, and a position in the message at which to insert the data-checking value.

10. A method according to claim 7 wherein the second program runs on a host channel adapter.

11. A method for off-loading calculation of a data-integrity-checking value for a remote direct memory access (RDMA) transfer to a specified portion of a memory window, the method comprising:

selecting a data-integrity-checking scheme from a specified set of schemes using an application program;

communicating the data-integrity-checking scheme to a second program, including expected address limits;

communicating address limits of the specified portion of the memory window to the second program after the transfer completes;

calculating the data-integrity-checking value according to the given data-integrity-checking scheme for the specified portion of the memory window using the second program, when the remote direct memory access (RDMA) transfer occurs; and

communicating the data-integrity-checking value to the application program.

12. A method according to claim 11 wherein calculating a data-integrity-checking value and communicating the data-integrity-checking value are performed by a host channel adapter.

13. A method for off-loading calculation of a data-integrity-checking value for a direct memory access transfer to a specified portion of a memory window, the method comprising:

selecting a data-integrity-checking scheme from a specified set of schemes using an application program;

communicating the data-integrity-checking scheme to a second program, including expected address limits;

communicating address limits of the specified portion of the memory window to the second program after the transfer completes;

calculating the data-integrity-checking value according to the given data-integrity-checking scheme for the specified portion of the memory window using the second program when the direct memory access transfer occurs; and

communicating the data-integrity-checking value to the application program;

wherein calculating the data-integrity-checking value using the second program includes:

initializing a hardware resource for calculating the value and setting a data-integrity-checking value valid flag to false;

calculating a data-integrity-checking value according to the scheme using the resource when the transfer occurs to expected address limits in the window;

setting the data-integrity-checking value valid flag to true and setting actual-transfer address-values, when the hardware resource completes the data integrity-checking value calculation;

reading the data-integrity-checking value valid flag and actual-transfer address-values using the second program when the application program queries the second program for the data-integrity-checking value, the query including the address limits of the specified portion of the memory window; and

calculating the data-integrity-checking value over the specified portion of the memory window using the second program when at least one of the following conditions is true: (1) the data-integrity-checking value valid flag is false and (2) actual-transfer address-values do not match the specified portion of the memory window.

14. A method for off-loading calculation of a data-integrity-checking value for a direct memory access transfer to a specified portion of a memory window, the method comprising:

selecting a data-integrity-checking scheme from a specified set of schemes using an application program;

communicating the data-integrity-checking scheme to a second program, including expected address limits;

communicating address limits of the specified portion of the memory window to the second program after the transfer completes;

calculating the data-integrity-checking value according to the given data-integrity-checking scheme for the specified portion of the memory window using the second program when the direct memory access transfer occurs; and

communicating the data-integrity-checking value to the application program;

wherein communicating the scheme is performed by a bind memory window operation and wherein the data-integrity-checking value is accessible to the application program by a query memory window operation.

15. A device for off-loading calculation of a data-integrity-checking value for a data message, the device comprising:

a first processor including:

logic for selecting a data-integrity-checking scheme from a specified set of schemes using an application program, wherein each scheme of the specified set of schemes identifies a corresponding data digest type to calculate a data-integrity-checking value; and

logic for communicating the data-integrity-checking scheme and the message; and

a second processor including:

logic for receiving the scheme and the data message from the first processor and calculating a data-integrity-checking value according to the scheme for the data message using a second program.

16. A device according to claim 15 , wherein the second processor further includes:

logic for transmitting the data-integrity-checking value.

17. A device for off-loading calculation of a data-integrity-checking value for a message, the message received at a computer system, the device comprising:

a first processor including:

logic for selecting a data-integrity-checking scheme from a specified set of schemes, the logic executed by an application program, and

logic for communicating the data-integrity-checking scheme and an identifier for the message; and

a second processor including:

logic for receiving the scheme and the message identifier from the first processor and calculating the data-integrity-checking value according to the data-integrity-checking scheme for the message, the logic executed by a second program, and

logic for communicating the given message and the data-integrity-checking value to the first processor.

18. A device for off-loading calculation of a data-integrity-checking value for a direct memory access transfer to a specified portion of a memory window, the device comprising:

a first processor including:

logic for selecting a data-integrity-checking scheme from a specified set of schemes, the logic executed by an application program,

logic for communicating the data-integrity-checking scheme including expected address limits, and

logic for communicating address limits of the specified portion of the memory window after the transfer completes; and

a second processor including:

logic for receiving the scheme from the first processor, receiving the address limits of the specified portion of the address window after the transfer completes and calculating a data-integrity-checking value according to the scheme for the specified portion of the window, when the direct memory access transfer completes, the logic executed by a second program; and

logic for communicating the data-integrity-checking value to the first processor.

19. A device according to claim 18 wherein logic for calculating a data-integrity-checking value includes:

logic for initializing a hardware resource for calculating the value and setting a data-integrity-checking value valid flag to false;

logic for calculating a data-integrity-checking value according to the scheme using the resource when the transfer occurs to expected address limits in the window;

logic for setting the data-integrity-checking value valid flag to true and setting actual-transfer address-values, when the hardware resource completes the data integrity-checking value calculation;

logic for reading the data-integrity-checking value valid flag and actual-transfer address-values using the second program when the application program queries the second program for the data-integrity-checking value, the query including the address limits of the specified portion of the memory window; and

logic for calculating the data-integrity-checking value over the specified portion of the memory window using the second program when at least one of the following conditions is true: (1) the data-integrity-checking value valid flag is false and (2) actual-transfer address-values do not match the specified portion of the memory window.