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Subject: Re: [PATCH 2/7 v2] powerpc/dma-mapping: override dma_get_page_shift
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>, Alexey Kardashevskiy
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Date: Wed, 28 Oct 2015 11:20:05 +0900
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On Tue, 2015-10-27 at 18:54 -0700, Nishanth Aravamudan wrote:
> 
> In "bypass" mode, what TCE size is used? Is it guaranteed to be 4K?

None :-) The TCEs are completely bypassed. You get a N:M linear mapping
of all memory starting at 1<<59 PCI side.

> Seems like this would be a different platform implentation I'd put in
> for 'powernv', is that right?
> 
> My apologies for missing that, and thank you for the review!

Cheers,
Ben.