Re: [PATCH v3 2/7] dma: Introduce dma_aligned_pow2_mask()

[Peter Xu]

On Tue, Mar 09, 2021 at 11:27:37AM +0100, Eric Auger wrote:
> Currently get_naturally_aligned_size() is used by the intel iommu
> to compute the maximum invalidation range based on @size which is
> a power of 2 while being aligned with the @start address and less
> than the maximum range defined by @gaw.
> 
> This helper is also useful for other iommu devices (virtio-iommu,
> SMMUv3) to make sure IOMMU UNMAP notifiers only are called with
> power of 2 range sizes.
> 
> Let's move this latter into dma-helpers.c and rename it into
> dma_aligned_pow2_mask(). Also rewrite the helper so that it
> accomodates UINT64_MAX values for the size mask and max mask.
> It now returns a mask instead of a size. Change the caller.
> 
> Signed-off-by: Eric Auger <eric.auger@redhat.com>

Reviewed-by: Peter Xu <peterx@redhat.com>

-- 
Peter Xu