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Subject: Re: [PATCH v5 1/7] powerpc/mm: update ptep_set_access_flag to not
 do full mm tlb flush
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>, Paul Mackerras
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Cc: mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org
Date: Fri, 25 Nov 2016 19:22:47 +1100
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On Fri, 2016-11-25 at 12:35 +0530, Aneesh Kumar K.V wrote:
> Now the question will be how will we support _PAGE_DEVMAP (for
> nvidmm).
> We don't have free software pte bits after we make the above change.
> 
> NOTE: We do have 3 reserved bits(ppc bit 4-6 ) can we use that ?

Yes, I think we can, at least as long as it's a DD1 thing only, future
processors might re-use these.

Cheers,
Ben.