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| author | Mitchel Humpherys <mitchelh@codeaurora.org> | 2015-03-26 11:59:02 -0700 |
|---|---|---|
| committer | David Keitel <dkeitel@codeaurora.org> | 2016-03-22 11:11:57 -0700 |
| commit | eadb730a2d0bff616d60368778e087ae6e4c3ec3 (patch) | |
| tree | d6f4f7314870b4367e7a950cd216c4b4dad00479 /include/linux/platform_data | |
| parent | 0ae59a3564a4ecebcd6dfc64ecba09bced3322cb (diff) | |
arm64: dma-mapping: avoid calling iommu_iova_to_phys
We're currently asking the IOMMU layer to do an iova-to-phys translation
in .unmap_page and .sync_single_for_* in the IOMMU DMA mapper. This can
be a costly operation since it will need to walk the domain's page
tables, either in software or in hardware. Also, in some
less-than-ideal implementations of iommu_iova_to_phys this might
actually involve sleeping operations.
Avoid this overhead by saving the physical address of the buffer in the
dma_iommu_mapping structure in .map_page, using it later instead of
iommu_iova_to_phys.
Change-Id: Ic53b91a222dab01cfcdc34246a847a8c399adfb6
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
Diffstat (limited to 'include/linux/platform_data')
0 files changed, 0 insertions, 0 deletions