Messages in this thread |  | | | Subject | Re: [RFC 3/3] mm: iommu: The Virtual Contiguous Memory Manager | | From | Daniel Walker <> | | Date | Thu, 01 Jul 2010 15:05:44 -0700 |
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On Thu, 2010-07-01 at 15:00 -0700, Zach Pfeffer wrote:
> Additionally, the current IOMMU interface does not allow users to > associate one page table with multiple IOMMUs unless the user explicitly > wrote a muxed device underneith the IOMMU interface. This also could be > done, but would have to be done for every such use case. Since the > particular topology is run-time configurable all of these use-cases and > more can be expressed without pushing the topology into the low-level > IOMMU driver. > > The VCMM takes the long view. Its designed for a future in which the > number of IOMMUs will go up and the ways in which these IOMMUs are > composed will vary from system to system, and may vary at > runtime. Already, there are ~20 different IOMMU map implementations in > the kernel. Had the Linux kernel had the VCMM, many of those > implementations could have leveraged the mapping and topology management > of a VCMM, while focusing on a few key hardware specific functions (map > this physical address, program the page table base register).
So if we include this code which "map implementations" could you collapse into this implementations ? Generally , what currently existing code can VCMM help to eliminate?
Daniel
-- Sent by a consultant of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.
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