On Thu, Aug 12, 2021 at 3:47 AM Robin Murphy <[email protected]> wrote: > > On 2021-08-11 03:42, David Stevens wrote: > > From: David Stevens <[email protected]> > > > > When calling arch_sync_dma, we need to pass it the memory that's > > actually being used for dma. When using swiotlb bounce buffers, this is > > the bounce buffer. Move arch_sync_dma into the __iommu_dma_map_swiotlb > > helper, so it can use the bounce buffer address if necessary. This also > > means it is no longer necessary to call iommu_dma_sync_sg_for_device in > > iommu_dma_map_sg for untrusted devices. > > > > Fixes: 82612d66d51d ("iommu: Allow the dma-iommu api to use bounce buffers") > > Signed-off-by: David Stevens <[email protected]> > > --- > > drivers/iommu/dma-iommu.c | 16 +++++++--------- > > 1 file changed, 7 insertions(+), 9 deletions(-) > > > > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c > > index 54e103b989d9..4f0cc4a0a61f 100644 > > --- a/drivers/iommu/dma-iommu.c > > +++ b/drivers/iommu/dma-iommu.c > > @@ -576,6 +576,9 @@ static dma_addr_t __iommu_dma_map_swiotlb(struct device > > *dev, phys_addr_t phys, > > memset(padding_start, 0, padding_size); > > } > > > > + if (!coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC)) > > Make that an "else if" - otherwise you're just reintroducing the same > thing that the third hunk is trying to clean up.
swiotlb_tbl_map_single only copies into the swiotlb buffer, it doesn't do any architectural syncing. So this block is necessary in the swiotlb case as well, for iommu_dma_map_page to work properly. The third chunk is a separate optimization, so I'll split it out into its own patch. -David _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
