Re: [PATCH kernel v9 08/32] vfio: powerpc/spapr: Moving pinning/unpinning to helpers

[David Gibson]

On Sat, Apr 25, 2015 at 10:14:32PM +1000, Alexey Kardashevskiy wrote:
> This is a pretty mechanical patch to make next patches simpler.
> 
> New tce_iommu_unuse_page() helper does put_page() now but it might skip
> that after the memory registering patch applied.
> 
> As we are here, this removes unnecessary checks for a value returned
> by pfn_to_page() as it cannot possibly return NULL.
> 
> This moves tce_iommu_disable() later to let tce_iommu_clear() know if
> the container has been enabled because if it has not been, then
> put_page() must not be called on TCEs from the TCE table. This situation
> is not yet possible but it will after KVM acceleration patchset is
> applied.
> 
> This changes code to work with physical addresses rather than linear
> mapping addresses for better code readability. Following patches will
> add an xchg() callback for an IOMMU table which will accept/return
> physical addresses (unlike current tce_build()) which will eliminate
> redundant conversions.
> 
> Signed-off-by: Alexey Kardashevskiy <aik@xxxxxxxxx>
> [aw: for the vfio related changes]
> Acked-by: Alex Williamson <alex.williamson@xxxxxxxxxx>

Reviewed-by: David Gibson <david@xxxxxxxxxxxxxxxxxxxxx>

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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