| Message ID | 20210107122909.16317-7-yong.wu@mediatek.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | MediaTek IOMMU improve tlb flush performance in map/unmap | expand |
On 2021-01-07 12:29, Yong Wu wrote: > In current iommu_unmap, this code is: > > iommu_iotlb_gather_init(&iotlb_gather); > ret = __iommu_unmap(domain, iova, size, &iotlb_gather); > iommu_iotlb_sync(domain, &iotlb_gather); > > We could gather the whole iova range in __iommu_unmap, and then do tlb > synchronization in the iommu_iotlb_sync. > > This patch implement this, Gather the range in mtk_iommu_unmap. > then iommu_iotlb_sync call tlb synchronization for the gathered iova range. > we don't call iommu_iotlb_gather_add_page since our tlb synchronization > could be regardless of granule size. > > In this way, gather->start is impossible ULONG_MAX, remove the checking. > > This patch aims to do tlb synchronization *once* in the iommu_unmap. Reviewed-by: Robin Murphy <robin.murphy@arm.com> > Signed-off-by: Yong Wu <yong.wu@mediatek.com> > --- > drivers/iommu/mtk_iommu.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c > index 66a00a2cb445..d3b8a1649093 100644 > --- a/drivers/iommu/mtk_iommu.c > +++ b/drivers/iommu/mtk_iommu.c > @@ -430,7 +430,12 @@ static size_t mtk_iommu_unmap(struct iommu_domain *domain, > struct iommu_iotlb_gather *gather) > { > struct mtk_iommu_domain *dom = to_mtk_domain(domain); > + unsigned long end = iova + size - 1; > > + if (gather->start > iova) > + gather->start = iova; > + if (gather->end < end) > + gather->end = end; > return dom->iop->unmap(dom->iop, iova, size, gather); > } > > @@ -445,9 +450,6 @@ static void mtk_iommu_iotlb_sync(struct iommu_domain *domain, > struct mtk_iommu_data *data = mtk_iommu_get_m4u_data(); > size_t length = gather->end - gather->start + 1; > > - if (gather->start == ULONG_MAX) > - return; > - > mtk_iommu_tlb_flush_range_sync(gather->start, length, gather->pgsize, > data); > } >
diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c index 66a00a2cb445..d3b8a1649093 100644 --- a/drivers/iommu/mtk_iommu.c +++ b/drivers/iommu/mtk_iommu.c @@ -430,7 +430,12 @@ static size_t mtk_iommu_unmap(struct iommu_domain *domain, struct iommu_iotlb_gather *gather) { struct mtk_iommu_domain *dom = to_mtk_domain(domain); + unsigned long end = iova + size - 1; + if (gather->start > iova) + gather->start = iova; + if (gather->end < end) + gather->end = end; return dom->iop->unmap(dom->iop, iova, size, gather); } @@ -445,9 +450,6 @@ static void mtk_iommu_iotlb_sync(struct iommu_domain *domain, struct mtk_iommu_data *data = mtk_iommu_get_m4u_data(); size_t length = gather->end - gather->start + 1; - if (gather->start == ULONG_MAX) - return; - mtk_iommu_tlb_flush_range_sync(gather->start, length, gather->pgsize, data); }
In current iommu_unmap, this code is: iommu_iotlb_gather_init(&iotlb_gather); ret = __iommu_unmap(domain, iova, size, &iotlb_gather); iommu_iotlb_sync(domain, &iotlb_gather); We could gather the whole iova range in __iommu_unmap, and then do tlb synchronization in the iommu_iotlb_sync. This patch implement this, Gather the range in mtk_iommu_unmap. then iommu_iotlb_sync call tlb synchronization for the gathered iova range. we don't call iommu_iotlb_gather_add_page since our tlb synchronization could be regardless of granule size. In this way, gather->start is impossible ULONG_MAX, remove the checking. This patch aims to do tlb synchronization *once* in the iommu_unmap. Signed-off-by: Yong Wu <yong.wu@mediatek.com> --- drivers/iommu/mtk_iommu.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)