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Subject: Re: [PATCH v4 11/16] powerpc/powernv: Release replaced TCE
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Alexey Kardashevskiy <aik@ozlabs.ru>
Date: Wed, 06 Aug 2014 16:27:37 +1000
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Cc: Michael Ellerman <michael@ellerman.id.au>,
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On Wed, 2014-07-30 at 19:31 +1000, Alexey Kardashevskiy wrote:
> 
> This adds a set_and_get() callback to iommu_table_ops which does the
> same
> thing as set() plus it returns replaced TCE(s) so the caller can
> release
> the pages afterwards.

Call it xchg() instead of set_and_get(), it better reflects the
atomicity requirement.

Cheers,
Ben.