On Thu, 30 Sep 2021 13:44:54 +1000, Alexey Kardashevskiy wrote:
> According to dma-api.rst, the dma_get_required_mask() helper should return
> "the mask that the platform requires to operate efficiently". Which in
> the case of PPC64 means the bypass mask and not a mask from an IOMMU table
> which
On Thu, Sep 30, 2021 at 01:44:54PM +1000, Alexey Kardashevskiy wrote:
> and returns the IOMMU table mask on the pseries platform which makes some
> drivers (mpt3sas is one example) choose 32bit DMA even though bypass is
> supported. The powernv platform sort of handles it by having a bigger
> defau
According to dma-api.rst, the dma_get_required_mask() helper should return
"the mask that the platform requires to operate efficiently". Which in
the case of PPC64 means the bypass mask and not a mask from an IOMMU table
which is shorter and slower to use due to map/unmap operations (especially
exp
