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Date: Wed, 22 Aug 2018 09:04:07 +0200
From: Christoph Hellwig <hch@lst.de>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Christoph Hellwig <hch@lst.de>, Paul Mackerras <paulus@samba.org>,
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 Robin Murphy <robin.murphy@arm.com>, linuxppc-dev@lists.ozlabs.org,
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Subject: Re: [PATCH 17/20] powerpc/dma-swiotlb: use generic swiotlb_dma_ops
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On Thu, Aug 09, 2018 at 11:57:53AM +1000, Benjamin Herrenschmidt wrote:
> Note: We will still need to implement some custom variant of this
> for our secure VMs ... 
> 
> Basically we'll need to use the existing bounce bufferring as-is but
> the condition will be different, it won't be whether the address is
> below a certain limit, it will be *always*.

The conditions are in the dma_capable() helper that the architecture
can override (and which powerpc already does override).