Providing data integrity for data streams

• US 20060074960A1
• Filed: 09/20/2004
• Published: 04/06/2006
• Est. Priority Date: 09/20/2004
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Sheffield, Robert L., Beckett, Richard C., Schmisseur, Mark A., Goldschmidt, Marc A.
• Granted Patent: US 7,340,672 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 2211/109 Sector level checksum or ECC, i.e. sector or stripe level checksum or ECC in addition to the RAID parity calculation
• CPC Class Codes: H03M 13/11 using multiple parity bits
• CPC Class Codes: H04L 1/0065 Serial concatenated codes
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27

Abstract

Provided are a method, system, and article of manufacture for providing data integrity for data streams. Input data streams are received. A parity data stream is generated by computing parity data from the input data streams, wherein the parity data stream comprises data blocks. Data integrity fields are computed for the data blocks, wherein a data integrity field is used to ensure the integrity of a data block for which the data integrity field is computed. The computed data integrity fields are added to the data blocks to generate an output stream.

Claims

1. A method, comprising:

receiving input data streams;

generating a parity data stream by computing parity data from the input data streams, wherein the parity data stream comprises data blocks;

computing data integrity fields for the data blocks, wherein a data integrity field is used to ensure the integrity of a data block for which the data integrity field is computed; and

adding the computed data integrity fields to the data blocks to generate an output stream.

2. The method of claim 1, wherein the input data streams and the parity data stream comprise a plurality of bytes, and wherein generating the parity data stream further comprises:

generating a first byte of the parity data by an exclusive OR operation of first bytes of the input data streams;

adding the first byte of the parity data to the parity data stream;

generating a next byte of the parity data by an exclusive OR operation of next bytes of the input data streams, in response to determining that there are additional bytes of the input data streams for which parity data byte has not been generated; and

adding the next byte of the parity data to the parity data stream.

3. The method of claim 1, wherein the parity data stream is generated by a parity generating unit, and further comprising:

computing, by a data integrity function, one data integrity field for one data block in a source data stream.

4. The method of claim 1, wherein the input data streams are block guarded input data streams, and further comprising:

receiving, at a controller, a plurality of data streams;

applying a data integrity function to the plurality of data streams to form the block guarded input data streams; and

sending the block guarded input data streams to a parity generating unit to generate the parity data stream.

5. The method of claim 4, wherein the data integrity function is a first data integrity function, wherein computing the data integrity fields and adding the computed data integrity fields to the data blocks are performed by a second data integrity function, wherein the parity data stream is generated by a parity generating unit, and wherein the first and second data integrity functions further perform:

computing one data integrity field for an expanded data block in a source data stream; and

adding the one data integrity field to the source data stream.

6. The method of claim 4, wherein the data integrity function is a first data integrity function, wherein computing the data integrity fields and adding the computed data integrity fields to the data blocks are performed by a second data integrity function, wherein the parity data stream is generated by a parity generating unit, and wherein the first and second data integrity functions further perform:

computing one data integrity field for an expanded data block in a source data stream; and

verifying that the one data integrity field matches an existing data integrity field embedded in the expanded data block.

7. The method of claim 4, wherein the data integrity function is a first data integrity function, wherein computing the data integrity fields and adding the computed data integrity fields to the data blocks are performed by a second data integrity function, wherein the parity data stream is generated by a parity generating unit, and wherein the first and second data integrity functions further perform:

removing one data integrity field for an expanded data block to generate a compressed data block; and

writing the generated compressed data block.

8. The method of claim 1, wherein receiving, generating, computing, and adding are performed by a storage controller comprising a parity generating unit, a data integrity engine, and an interface unit, wherein the parity data stream is generated by the parity generating unit, wherein computing the data integrity fields and adding the computed data integrity fields to the data blocks are performed by the data integrity engine, the method further comprising:

sending the output stream to the interface unit for transmission to a bus.

9. A system, comprising:

memory; and

circuitry coupled to the memory, wherein the circuitry is operable to;

(i) receive input data streams;

(ii) generate a parity data stream by computing parity data from the input data streams, wherein the parity data stream comprises data blocks;

(iii) compute data integrity fields for the data blocks, wherein a data integrity field is used to ensure the integrity of a data block for which the data integrity field is computed; and

(iv) add the computed data integrity fields to the data blocks to generate an output stream.

10. The system of claim 9, wherein the input data streams and the parity data stream comprise a plurality of bytes, and wherein the circuitry is further operable to:

generate a first byte of the parity data by an exclusive OR operation of first bytes of the input data streams;

add the first byte of the parity data to the parity data stream;

generate a next byte of the parity data by an exclusive OR operation of next bytes of the input data streams, in response to determining that there are additional bytes of the input data streams for which parity data byte has not been generated; and

add the next byte of the parity data to the parity data stream.

11. The system of claim 9, further comprising a parity generating unit and a data integrity function, wherein the parity data stream is generated by the parity generating unit, and wherein the circuitry is further operable to:

compute, by the data integrity function, one data integrity field for one data block in a source data stream.

12. The system of claim 9, further comprising:

a controller, wherein the input data streams are block guarded input data streams, and wherein the circuitry is further operable to;

(i) receive, at the controller, a plurality of data streams;

(ii) apply a data integrity function to the plurality of data streams to form the block guarded input data streams; and

(iii) send the block guarded input data streams to a parity generating unit to generate the parity data stream.

13. The system of claim 12, further comprising a parity generating unit, wherein the data integrity function is a first data integrity function, wherein computing the data integrity fields and adding the computed data integrity fields to the data blocks are performed by a second data integrity function, wherein the parity data stream is generated by the parity generating unit, and wherein the circuitry is further operable to:

compute one data integrity field for an expanded data block in a source data stream; and

add the one data integrity field to the source data stream.

14. The system of claim 12, further comprising a parity generating unit, wherein the data integrity function is a first data integrity function, wherein computing the data integrity fields and adding the computed data integrity fields to the data blocks are performed by a second data integrity function, wherein the parity data stream is generated by the parity generating unit, and wherein the circuitry is further operable to:

compute one data integrity field for an expanded data block in a source data stream; and

verify that the one data integrity field matches an existing data integrity field embedded in the expanded data block.

15. The system of claim 12, further comprising a parity generating unit, wherein the data integrity function is a first data integrity function, wherein computing the data integrity fields and adding the computed data integrity fields to the data blocks are performed by a second data integrity function, wherein the parity data stream is generated by the parity generating unit, and wherein the circuitry is further operable to:

remove one data integrity field for an expanded data block to generate a compressed data block; and

write the generated compressed data block.

16. The system of claim 9, further comprising a storage controller, wherein receiving, generating, computing, and adding are performed by the storage controller having a parity generating unit, a data integrity engine, and an interface unit, wherein the parity data stream is generated by the parity generating unit, wherein computing the data integrity fields and adding the computed data integrity fields to the data blocks are performed by the data integrity engine, and wherein the circuitry is further operable to:

send the output stream to the interface unit for transmission to a bus.

17. A system, comprising:

memory;

a video controller coupled to the memory; and

a storage controller coupled to the memory, wherein the storage controller has circuitry that is operable to;

(i) receive input data streams;

(ii) generate a parity data stream by computing parity data from the input data streams, wherein the parity data stream comprises data blocks;

(iii) compute data integrity fields for the data blocks, wherein a data integrity field is used to ensure the integrity of a data block for which the data integrity field is computed; and

(iv) add the computed data integrity fields to the data blocks to generate an output stream.

18. The system of claim 17, wherein the input data streams and the parity data stream comprise a plurality of bytes, and wherein the circuitry is further operable to:

generate a first byte of the parity data by an exclusive OR operation of first bytes of the input data streams;

add the first byte of the parity data to the parity data stream;

generate a next byte of the parity data by an exclusive OR operation of next bytes of the input data streams, in response to determining that there are additional bytes of the input data streams for which parity data byte has not been generated; and

add the next byte of the parity data to the parity data stream.

19. The system of claim 17, wherein the storage controller has an accelerator unit, wherein the accelerator unit has a parity generating unit, wherein the input data. streams are block guarded input data streams, and wherein the circuitry is further operable to:

(i) receive, at the accelerator unit, a plurality of data streams;

(ii) apply a data integrity function to the plurality of data streams to form the block guarded input data streams; and

(iii) send the block guarded input data streams to the parity generating unit to generate the parity data stream.

20. An article of manufacture, comprising a storage medium having stored therein instructions capable of being executed by a machine to:

receive input data streams;

generate a parity data stream by computing parity data from the input data streams, wherein the parity data stream comprises data blocks;

compute data integrity fields for the data blocks, wherein a data integrity field is used to ensure the integrity of a data block for which the data integrity field is computed; and

add the computed data integrity fields to the data blocks to generate an output stream.

21. The article of manufacture of claim 20, wherein the input data streams and the parity data stream comprise a plurality of bytes, and wherein the instructions are further capable of being executed to:

generate a first byte of the parity data by an exclusive OR operation of first bytes of the input data streams;

add the first byte of the parity data to the parity data stream;

generate a next byte of the parity data by an exclusive OR operation of next bytes of the input data streams, in response to determining that there are additional bytes of the input data streams for which parity data byte has not been generated; and

add the next byte of the parity data to the parity data stream.

22. The article of manufacture of claim 20, wherein the parity data stream is generated by a parity generating unit coupled to a data integrity function, and wherein the instructions are further capable of being executed to:

compute, by the data integrity function, one data integrity field for one data block in a source data stream.

23. The article of manufacture of claim 20, wherein the input data streams are block guarded input data streams, and wherein the instructions are further capable of being executed to:

receive a plurality of data streams;

apply a data integrity function to the plurality of data streams to form the block guarded input data streams; and

send the block guarded input data streams to a parity generating unit to generate the parity data stream.

24. The article of manufacture of claim 23, wherein the data integrity function is a first data integrity function, wherein computing the data integrity fields and adding the computed data integrity fields to the data blocks are performed by a second data integrity function, and wherein the instructions are further capable of being executed to:

compute one data integrity field for an expanded data block in a source data stream; and

add the one data integrity field to the source data stream.

25. The article of manufacture of claim 23, wherein the data integrity function is a first data integrity function, wherein computing the data integrity fields and adding the computed data integrity fields to the data blocks are performed by a second data integrity function, and wherein the instructions are further capable of being executed to:

compute one data integrity field for an expanded data block in a source data stream; and

verify that the one data integrity field matches an existing data integrity field embedded in the expanded data block.

26. The article of manufacture of claim 23, wherein the data integrity function is a first data integrity function, wherein computing the data integrity fields and adding the computed data integrity fields to the data blocks are performed by a second data integrity function, and wherein the instructions are further capable of being executed to:

remove one data integrity field for an expanded data block to generate a compressed data block; and

write the generated compressed data block.

27. The article of manufacture of claim 20, wherein receiving, generating, computing, and adding are performed by a storage controller comprising a parity generating unit, a data integrity engine, and an interface unit, wherein the parity data stream is generated by the parity generating unit, wherein computing the data integrity fields and adding the computed data integrity fields to the data blocks are performed by the data integrity engine, and wherein the instructions are further capable of being executed to:

send the output stream to the interface unit for transmission to a bus.