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Subject: Re: [PATCH 0/5 v2] Fix NVMe driver support on Power with 32-bit DMA
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>, Matthew Wilcox
 <willy@linux.intel.com>
Cc: Keith Busch <keith.busch@intel.com>, Paul Mackerras <paulus@samba.org>,
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 Hellwig <hch@infradead.org>, linux-nvme@lists.infradead.org,
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Date: Sat, 03 Oct 2015 06:51:06 +1000
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 <20151002200953.GB40695@linux.vnet.ibm.com>
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On Fri, 2015-10-02 at 13:09 -0700, Nishanth Aravamudan wrote:

> 1) add a generic dma_get_page_shift implementation that just returns
> PAGE_SHIFT

So you chose to return the granularity of the iommu to the driver
rather than providing a way for the driver to request a specific
alignment for DMA mappings. Any specific reason ?

Cheers,
Ben.