[PATCH] iommu/io-pgtable: Remove tlb_flush_leaf

Will Deacon will at kernel.org
Thu Dec 3 06:53:11 EST 2020


On Wed, Nov 25, 2020 at 05:29:39PM +0000, Robin Murphy wrote:
> The only user of tlb_flush_leaf is a particularly hairy corner of the
> Arm short-descriptor code, which wants a synchronous invalidation to
> minimise the races inherent in trying to split a large page mapping.
> This is already far enough into "here be dragons" territory that no
> sensible caller should ever hit it, and thus it really doesn't need
> optimising. Although using tlb_flush_walk there may technically be
> more heavyweight than needed, it does the job and saves everyone else
> having to carry around useless baggage.
> 
> Signed-off-by: Robin Murphy <robin.murphy at arm.com>
> ---
> 
> Reviewing the Mediatek TLB optimisation patches just left me thinking
> "why do we even have this?"... Panfrost folks, this has zero functional
> impact to you, merely wants an ack for straying outside drivers/iommu.

Thanks, this looks good to me, but I'll defer queuing it until the last
minute so that I can merge all the iommu component branches together
first and then apply this on top. Should happen next week.

Will



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