Method to improve system DMA mapping while substantially...

Details Method to improve system DMA mapping while substantially... Method to improve system DMA mapping while substantially...

2006-03-21

2010-06-15

Tsai, Henry W. H. (Department: 2184)

Electrical computers and digital data processing systems: input/

Input/output data processing

Direct memory accessing

Reexamination Certificate

active

07739422

ABSTRACT:
A method, system and computer program product for eliminating the latency in searching for contiguous memory space by an IO DMA request of a device driver. Three new application programming interfaces (APIs) are provided within the operating system (OS) code that allows the device driver(s) to (1) pre-request and pre-allocate the IO DMA address range from the OS during the IPL and maintain control of the address, (2) map a system (virtual/physical) address range to a specific pre-allocated IO DMA address range, and (3) free the pre-allocated IO DMA address space back to the kernel when the space is no longer required. Utilizing these APIs enables advanced IO DMA address mapping techniques maintained by the device drivers, and the assigned/allocated IO DMA address space is no longer fragmented, and the latency of completing the IO DMA mapping is substantially reduced/eliminated.

REFERENCES:
patent: 5815678 (1998-09-01), Hoffman et al.
patent: 5991520 (1999-11-01), Smyers et al.
patent: 6128713 (2000-10-01), Eisler et al.
patent: 6243783 (2001-06-01), Smyers et al.
patent: 6629162 (2003-09-01), Arndt et al.
patent: 6662242 (2003-12-01), Holm et al.
patent: 6704808 (2004-03-01), Kasamatsu et al.
Hua et al., Method for Minimizing the Translation Overhead for Large I/O Transfers, U.S. Appl. No. 10/965,633, filed Oct. 14, 2004.
Tago, High Performance DMA, IBM Technical Disclosure Bulletin, v36, n11, Nov. 1993, pp. 139-140.
Lyons, Resource Management for Non-Micro Channel DMA Masters, IBM Technical Disclosure Bulletin, v38, n10, Oct. 1995, pp. 537-540.

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