[PATCH 0/4] MTK_IOMMU: Optimize mapping / unmapping performance

Chao Hao chao.hao at mediatek.com
Mon Oct 19 07:30:56 EDT 2020


    For MTK platforms, mtk_iommu is using iotlb_sync(), tlb_add_range() and tlb_flush_walk/leaf()
to do tlb sync when iommu driver runs iova mapping/unmapping. But if buffer size is large,
it maybe consist of many pages(4K/8K/64K/1MB......). So iommu driver maybe run many times tlb
sync in mapping for this case and it will degrade performance seriously. In order to resolve the
issue, we hope to add iotlb_sync_range() callback in iommu_ops, it can appiont iova and size to
do tlb sync. MTK_IOMMU will use iotlb_sync_range() callback when the whole mapping/unmapping is
completed and remove iotlb_sync(), tlb_add_range() and tlb_flush_walk/leaf().
    So this patchset will replace iotlb_sync(), tlb_add_range() and tlb_flush_walk/leaf() with
iotlb_sync_range() callback.

Chao Hao (4):
  iommu: Introduce iotlb_sync_range callback
  iommu/mediatek: Add iotlb_sync_range() support
  iommu/mediatek: Remove unnecessary tlb sync
  iommu/mediatek: Adjust iotlb_sync_range

    drivers/iommu/dma-iommu.c |  9 +++++++++
    drivers/iommu/iommu.c     |  7 +++++++
    drivers/iommu/mtk_iommu.c | 36 ++++++++----------------------------
    include/linux/iommu.h     |  2 ++
    4 files changed, 26 insertions(+), 28 deletions(-)

--
2.18.0


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