On Thu, Sep 20, 2018 at 06:00:46PM +0100, Jean-Philippe Brucker wrote: > Provide an API for allocating PASIDs and populating them manually. To ease > cleanup and factor allocation code, reuse the io_mm structure for private > PASID. Private io_mm has a NULL mm_struct pointer, and cannot be bound to > multiple devices. The mm_alloc() IOMMU op must now check if the mm > argument is NULL, in which case it should allocate io_pgtables instead of > binding to an mm. > > Signed-off-by: Jordan Crouse <jcrouse@xxxxxxxxxxxxxx> > Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@xxxxxxx> > --- > Sadly this probably won't be the final thing. The API in this patch is > used like this: > > iommu_sva_alloc_pasid(dev, &io_mm) -> PASID > iommu_sva_map(io_mm, ...) > iommu_sva_unmap(io_mm, ...) > iommu_sva_free_pasid(dev, io_mm) > > The proposed API for auxiliary domains is in an early stage but might > replace this patch and could be used like this: > > iommu_enable_aux_domain(dev) > d = iommu_domain_alloc() > iommu_attach_aux(dev, d) > iommu_aux_id(d) -> PASID > iommu_map(d, ...) > iommu_unmap(d, ...) > iommu_detach_aux(dev, d) > iommu_domain_free(d) > > The advantage being that the driver doesn't have to use a special > version of map/unmap/etc. Hi Jean-Phillippe - Have you thought about this any more? I want to send out a refresh for the per-context pagetables for arm-smmu so if we want to change the underlying assumptions this would be a great time. For my part I'm okay with either model. In fact the second one is closer to the original implementation that I sent out so I have a clear development path in mind for either option depending on what the community decides. Thanks, Jordan <snip the rest of the patch> -- The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project
