Re: [RFC PATCH 0/3] iommu: Add range flush operation

[Joerg Roedel]

On Tue, Sep 29, 2015 at 11:27:14AM +0200, Thierry Reding wrote:
> On Tue, Sep 29, 2015 at 02:25:23PM +0900, Tomasz Figa wrote:
> >  3) possibility of exporting the iommu_flush() operation and providing
> >     unsynchronized map/unmap operations for subsystems with even higher
> >     requirements for performance (e.g. drivers/gpu/drm).
> 
> That would require passing in some sort of flag that the core shouldn't
> be flushing itself, right? Currently it would flush on every map/unmap.

Not necessarily. Introducing a flag would require updating all callers,
so while at it we could also just change the semantics of map/unmap to
require an explicit flush afterwards (only if it turns out that such an
iommu_flush() function is really needed).



	Joerg

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