Patent ID: 7644198

Claim:
A computer-implemented method comprising: selecting, at a DMA (Direct Memory Access) queue, a DMA command, the DMA command including a plurality of DMA command fields, the plurality of DMA command fields including a real page number field and a transfer size field; determining whether a real page number included in the real page number field is valid; providing, in response to determining that the real page number is valid, the real page number from the DMA queue to process the DMA command; identifying a transfer size that is included in the transfer size field, the transfer size indicating an amount of data to be transferred for the DMA command; detecting a maximum transfer size allowed value that identifies a maximum amount of data capable of being transferred during a DMA request; subtracting the maximum transfer size allowed value from the transfer size, the subtracting resulting in a decremented transfer size that is greater than zero; receiving write back information in response to providing the real page number, the write back information including the decremented transfer size and the real page number; and storing the received real page number in the real page number field and storing the decremented transfer size in the transfer size field, the decremented transfer size indicating the amount of data that remains to be transferred for the DMA command after processing the DMA request.