[PATCH] powerpc/iommu: use iommu_num_pages() to calculate the number of iommu page

[Wei Yang]

Someone willing to take a look?

On Fri, Oct 02, 2015 at 06:51:59AM +0800, Wei Yang wrote:
>On Thu, Oct 01, 2015 at 02:15:45PM +1000, Michael Ellerman wrote:
>>On Thu, 2015-10-01 at 07:50 +0800, Wei Yang wrote:
>>> Hmm... some comments on this one? like it or not?
>>
>>It sounds like it's fixing a bug, but you don't really say. Have you seen this
>>fail in the wild?
>
>Hmm... as described in the commit log, this would be a bug when 
>PAGE_SIZE is much smaller than IOMMU Page Size. This configuration doesn't
>happen on current platform. So I didn't see this failure yet.
>
>>
>>Which commit introduced the breakage?
>
>Hmm...  maybe we could say it is 'commit d084775738b7
><powerpc/iommu: Update the generic code to use dynamic iommu page sizes>'.
>>From this commit, powerpc iommu supports dynamic iommu page size. 
>
>Before this commit, the size is aligned with PAGE_SIZE, so the value after
>shift would be non-zero. After this commit, when PAGE_SIZE is smaller than
>the IOMMU Page Size, shift right will make the size 0.
>
>>
>>cheers
>>
>
>-- 
>Richard Yang
>Help you, Help me

-- 
Richard Yang
Help you, Help me