Re: [PATCH 1/2] dma-mapping: introduce dma_get_seg_boundary_nr_pages()

Michael Ellerman
2020-09-03T03:48:02Z

Nicolin Chen <nicoleotsuka@gmail.com> writes:
> diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
> index 9704f3f76e63..cbc2e62db597 100644
> --- a/arch/powerpc/kernel/iommu.c
> +++ b/arch/powerpc/kernel/iommu.c
> @@ -236,15 +236,10 @@ static unsigned long iommu_range_alloc(struct device *dev,
> }
> }
>
> - if (dev)
> - boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1,
> - 1 << tbl->it_page_shift);
> - else
> - boundary_size = ALIGN(1UL << 32, 1 << tbl->it_page_shift);
> - /* 4GB boundary for iseries_hv_alloc and iseries_hv_map */
> + boundary_size = dma_get_seg_boundary_nr_pages(dev, tbl->it_page_shift);
>
> n = iommu_area_alloc(tbl->it_map, limit, start, npages, tbl->it_offset,
> - boundary_size >> tbl->it_page_shift, align_mask);
> + boundary_size, align_mask);

This has changed the units of boundary_size, but it's unused elsewhere
in the function so that's OK.

If you need to do a v2 for any other reason, then I'd just drop
boundary_size and call dma_get_seg_boundary_nr_pages() directly in the
function call.

Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)

cheers