Data transfer device and data transfer method

• US 8,495,164 B2
• Filed: 06/07/2010
• Issued: 07/23/2013
• Est. Priority Date: 06/07/2010
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Torigoe, Osamu, Yauchi, Yusuke
• Primary Examiner(s): WANG, LIANG CHE A
• Application Number:
  US12/919,176
• Publication Number:
  US 20120185554A1
• Time in Patent Office: 1,142 Days
• Field of Search: 709/201, 709/212, 709/217, 709/218, 709/220, 709/223
• US Class Current: 709/212
• CPC Class Codes: G06F 13/28 using burst mode transfer, e.g. direct memory access DMA, cycle steal G06F13/32 takes precedence

Abstract

An object of the present invention is to efficiently perform a data transfer by using a plurality of data transfer devices. A storage apparatus 10 includes: a channel control unit 11 having a first DMA 1142, a second DMA 1112, and a memory 113; a processor unit 12; and a drive control unit 13 that communicates with a storage device 17. When the channel control unit 11 transfers to a host computer 3 data stored in a cache memory 14, the first DMA 1142 receives from a processor unit 12 a setting of a first transfer parameter 151 for the first DMA 1142 containing a second transfer parameter 152 for the second DMA 1112, performs a first data transfer from the cache memory 14 to the memory 113 according to the first transfer parameter 151, and sets the second transfer parameter in the second DMA 1112 thereby to cause the second DMA 1112 to perform a data transfer from the memory 113 to the host computer 3.

Claims

1. A data transfer device functioning as a first data transfer device in a data transfer control device which is configured to transfer data from a transfer source device to a transfer destination device via a memory, the data transfer device comprising:

the first data transfer device coupled to the transfer source device and the memory, and configured to perform a first data transfer of the data from the transfer source device to the memory according to a first transfer parameter, when the first transfer parameter is set; and

a second data transfer device coupled to the transfer destination device, the memory and the first data transfer device, and configured to perform a second data transfer of the data from the memory to the transfer destination device according to a second transfer parameter, when the second transfer parameter is set, wherein

the data transfer device is configured to;

receive the first transfer parameter containing the second transfer parameter;

perform the first data transfer according to the first transfer parameter; and

set the second transfer parameter contained in the first transfer parameter to the second data transfer device.

2. The data transfer device according to claim 1, wherein:

the data transfer device is configured to determine whether the first data transfer according to the first transfer parameter is completed or not, and to set the second data transfer device to have the second transfer parameter contained in the first transfer parameter when determining that the first data transfer is completed;

after receiving the setting of the second transfer parameter from the first data transfer device, the second data transfer device is configured to send to the memory a data read request for the second data transfer;

when receiving the data read request while the first data transfer is in progress, the memory is configured to hold the data read request thus received in a wait state until the first data transfer is completed, and to start the second data transfer after the first data transfer is completed;

after receiving the setting of the second transfer parameter from the first data transfer device, the second data transfer device is configured to determine whether the first data transfer is completed or not by accessing the memory, and to start the second data transfer when determining that the first data transfer is completed;

when starting the first data transfer, the first data transfer device is configured to send to the second data transfer device a start notification stating that the first data transfer is started;

after receiving the start notification, the second data transfer device is configured to start to access the memory;

the first data transfer device is configured to receive settings of first transfer parameters, and to perform the first data transfer according to each of the first transfer parameters thus received;

when receiving the settings of the first transfer parameters, the first data transfer device is configured to determine whether each of the received first transfer parameters contains the second transfer parameter or not;

when the first transfer parameter does not contain the second transfer parameter, the first data transfer device is configured to perform the first data transfer according to the first transfer parameter;

when the first transfer parameter contains the second transfer parameter, the first data transfer device is configured to perform the first data transfer according to the first transfer parameter, and also to set the second data transfer device to have the second transfer parameter contained in the first transfer parameter;

the first data transfer device includes a first DMA (Direct Memory Access) which is configured to perform the first data transfer according to the first transfer parameter;

the second data transfer device includes a second DMA which is configured to perform the second data transfer according to the second transfer parameter;

after completing the first data transfer, the first data transfer device is configured to notify a first completion status of the first data transfer;

after completing the second data transfer, the second data transfer device is configured to notify a second completion status of the second data transfer;

the first transfer parameter includes first transfer source information and first transfer destination information, the first transfer source information indicating a storage location in the transfer source device where data to be transferred by the first data transfer is stored, the first transfer destination information indicating a storage location in the memory where the data is to be stored;

the second transfer parameter includes second transfer source information and second transfer destination information, the second transfer source information indicating a storage location in the memory where data to be transferred by the second data transfer is stored, the second transfer destination information indicating a storage location in the transfer destination device where the data is to be stored;

the data transfer control device is included in a channel control unit in a storage apparatus including the channel control unit that is configured to communicate with a host computer;

a drive control unit that is configured to communicate with a storage device;

a cache memory;

a processor unit that is configured to perform a data transfer between the channel control unit, the drive control unit, and the cache memory; and

an internal switch that communicatively couples the channel control unit and the processor unit;

the memory is included in the channel control unit;

the transfer source device is the cache memory;

the transfer destination device is the host computer;

each of the devices is a microprocessor included in the processor unit;

the processor unit includes a memory and a plurality of the microprocessors;

after completing the first data transfer, the first data transfer device is configured to write a first completion status of the first data transfer into a storage area in the memory allocated to the microprocessor which has set the first transfer parameter; and

after completing the second data transfer, the second data transfer device is configured to write a second completion status of the second data transfer into a storage area in the memory allocated to the microprocessor which has set the first transfer parameter.

3. The data transfer device according to claim 1, wherein the data transfer device is configured to determine whether the first data transfer according to the first transfer parameter is completed or not, and to set the second data transfer device to have the second transfer parameter contained in the first transfer parameter when determining that the first data transfer is completed.

4. The data transfer device according to claim 1, wherein after receiving the setting of the second transfer parameter from the first data transfer device, the second data transfer device is configured to send to the memory a data read request for the second data transfer, and when receiving the data read request while the first data transfer is in progress, the memory is configured to hold the data read request thus received in a wait state until the first data transfer is completed, and thereafter when the first data transfer is completed, the memory is configured to start the second data transfer.

5. The data transfer device according to claim 1, wherein, after receiving the setting of the second transfer parameter from the first data transfer device, the second data transfer device is configured to determine whether the first data transfer is completed or not by accessing the memory, and to start the second data transfer when determining that the first data transfer is completed.

6. The data transfer device according to claim 5, wherein when starting the first data transfer, the first data transfer device is configured to send to the second data transfer device a start notification stating that the first data transfer is started, and after receiving the start notification, the second data transfer device is configured to start to access the memory.

7. The data transfer device according to claim 6, wherein the first data transfer device is configured to receive settings of first transfer parameters, and to perform the first data transfer according to each of the first transfer parameters thus received.

8. The data transfer device according to claim 1, wherein:

when receiving the settings of the first transfer parameters, the first data transfer device is configured to determine whether each of the received first transfer parameters contains the second transfer parameter or not;

when the first transfer parameter does not contain the second transfer parameter, the first data transfer device is configured to perform the first data transfer according to the first transfer parameter; and

when the first transfer parameter contains the second transfer parameter, the first data transfer device is configured to perform the first data transfer according to the first transfer parameter, and also to set the second data transfer device to have the second transfer parameter contained in the first transfer parameter.

9. The data transfer device according to claim 1, wherein the first data transfer device includes a first DMA (Direct Memory Access) which is configured to perform the first data transfer according to the first transfer parameter, and the second data transfer device includes a second DMA which is configured to perform the second data transfer according to the second transfer parameter.

10. The data transfer device according to claim 1, wherein after completing the first data transfer, the first data transfer device is configured to notify a first completion status of the first data transfer, and after completing the second data transfer, the second data transfer device is configured to notify a second completion status of the second data transfer.

11. The data transfer device according to claim 1, wherein the first transfer parameter includes first transfer source information and first transfer destination information, the first transfer source information indicating a storage location in the transfer source device where data to be transferred by the first data transfer is stored, the first transfer destination information indicating a storage location in the memory where the data is to be stored, and the second transfer parameter includes second transfer source information and second transfer destination information, the second transfer source information indicating a storage location in the memory where data to be transferred by the second data transfer is stored, the second transfer destination information indicating a storage location in the transfer destination device where the data is to be stored.

12. The data transfer device according to claim 1, wherein:

the data transfer control device is included in a channel control unit in a storage apparatus including;

the channel control unit that is configured to communicate with a host computer;

a drive control unit that is configured to communicate with a storage device;

a cache memory;

a processor unit that is configured to perform a data transfer between the channel control unit, the drive control unit, and the cache memory; and

an internal switch that is configured to communicatively couple the channel control unit and the processor unit;

the memory is included in the channel control unit;

the transfer source device is the cache memory;

the transfer destination device is the host computer.

13. The data transfer device according to claim 12, wherein:

the processor unit includes a memory and a plurality of microprocessors;

after completing the first data transfer, the first data transfer device is configured to write a first completion status of the first data transfer into a storage area in the memory allocated to the microprocessor which has set the first transfer parameter; and

after completing the second data transfer, the second data transfer device is configured to write a second completion status of the second data transfer into a storage area in the memory allocated to the microprocessor which has set the first transfer parameter.

14. A data transfer method using a data transfer control device, which is configured to transfer data from a transfer source device to a transfer destination device via a memory, the data transfer device comprising:

a first data transfer device coupled to the transfer source device and the memory, and configured to perform a first data transfer of the data from the transfer source device to the memory according to a first transfer parameter when the first transfer parameter is set; and

a second data transfer device coupled to the transfer destination device, the memory and the first data transfer device, and configured to perform a second data transfer of the data from the memory to the transfer destination device according to a second transfer parameter when the second transfer parameter is set, the method comprising;

causing the first data transfer device to receive the first transfer parameter containing the second transfer parameter;

performing the first data transfer according to the first transfer parameter; and

setting the second transfer parameter contained in the first transfer parameter to the second data transfer device.

15. The data transfer method according to claim 14, wherein the first data transfer device determines whether the first data transfer according to the first transfer parameter is completed or not, and sets the second data transfer device to have the second transfer parameter contained in the first transfer parameter when determining that the first data transfer is completed.