Non-fenced list DMA command mechanism

Abstract

A DMA controller (DMAC) for handling a list DMA command in a computer system is provided. The computer system has at least one processor and a system memory, the list DMA command relates to an effective address (EA) of the system memory, and the at least one processor has a local storage. The DMAC includes a DMA command queue (DMAQ) coupled to the local storage and configured to receive the list DMA command from the local storage and to enqueue the list DMA command. An issue logic is coupled to the DMAQ and configured to issue an issue request to the DMAQ. A request interface logic (RIL) is coupled to the DMAQ and configured to read the list DMA command based on the issue request. The RIL is further coupled to the local storage and configured to send a fetch request to the local storage to initiate a fetch of a list element of the list DMA command from the local storage to the DMAQ. Each list element comprises a stall bit indicating whether the list element is fenced and a DMA completion logic (DCL) is coupled to the at least one processor, the issue logic, and the RIL, and configured to indicate completion of all outstanding bus requests relating to the list element.

Dependencies are inferred from the claim text.