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Subject: Re: [RFC PATCH V1 14/33] powerpc/mm: Use helper for finding pte
 bits mapping I/O area
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Denis Kirjanov <kda@linux-powerpc.org>, "Aneesh Kumar K.V"
 <aneesh.kumar@linux.vnet.ibm.com>
Cc: paulus@samba.org, mpe@ellerman.id.au, Michael Neuling <mikey@neuling.org>,
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Date: Wed, 13 Jan 2016 14:57:17 +1100
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On Tue, 2016-01-12 at 10:42 +0300, Denis Kirjanov wrote:
> > +static inline unsigned long pte_io_cache_bits(void)
> > +{
> > +     return _PAGE_NO_CACHE | _PAGE_GUARDED;
> > +}
> This could be just plain #define

Or just use pgprot_noncached()

Cheers,
Ben.