Messages in this thread | | | Date | Mon, 30 Jan 2012 15:30:10 +0100 | From | Joerg Roedel <> | Subject | Re: [PATCH 2/5] iommu/amd: Implement DOMAIN_ATTR_GEOMETRY attribute |
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On Mon, Jan 30, 2012 at 06:27:30AM +0000, Sethi Varun-B16395 wrote:
> Can you please explain how would IOMMU remapping be used, based on the > force_aperture flag.
If force_aperture is flase the dma-api code needs to check if remapping is required at all. It performs the following checks:
* Does the physical address of the buffer not overlap with the aperture? * Fits the buffer into the device's dma address mask?
If both questions are answered with yes no remapping is required and dma-api just returns the physical address. Otherwise it calls into the dma-api to create a mapping.
Joerg
-- AMD Operating System Research Center
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