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:
Oct. 31, 2006
Filed:
Mar. 31, 2004
David Charles Boutcher, Rochester, MN (US);
Colin Robert Devilbiss, Rochester, MN (US);
David Robert Engebretsen, Cannon Falls, MN (US);
David Charles Boutcher, Rochester, MN (US);
Colin Robert DeVilbiss, Rochester, MN (US);
David Robert Engebretsen, Cannon Falls, MN (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A memory tag mechanism creates a logical memory tag of a first length that corresponds to an I/O address of a second length. The memory tag is 'logical' because it does not represent physical memory. When an I/O adapter device driver that expects an address of the first length is invoked, the memory tag is passed. When the I/O adapter device driver makes a call to the partition manager to convert the address of the first length (i.e., memory tag) to an I/O address of the second length, the partition manager detects that the passed address is a memory tag instead of a real address, and returns the corresponding I/O address. In this manner existing device drivers that expect addresses of the first length may be used for redirected DMA, which allows performing DMA operations directly from a shared I/O adapter in a hosting partition to memory in a hosted partition.