The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 15, 2010
Filed:
Mar. 21, 2006
Binh Hua, Austin, TX (US);
Hong L. Hua, Austin, TX (US);
Dirk Michel, Austin, TX (US);
Wen Xiong, Austin, TX (US);
Binh Hua, Austin, TX (US);
Hong L. Hua, Austin, TX (US);
Dirk Michel, Austin, TX (US);
Wen Xiong, Austin, TX (US);
International Business Machines Corporation, Armonk, NY (US);
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.