Re: [PATCH v3 3/6] iommu: Improve iommu_iotlb_gather helpers

[Robin Murphy]

On 2021-06-15 13:29, Yong Wu wrote:
> On Mon, 2021-06-07 at 11:25 -0700, Nadav Amit wrote:
> > From: Robin Murphy <robin.murphy@xxxxxxx>
> >
> > The Mediatek driver is not the only one which might want a basic
> > address-based gathering behaviour, so although it's arguably simple
> > enough to open-code, let's factor it out for the sake of cleanliness.
> > Let's also take this opportunity to document the intent of these
> > helpers for clarity.
> >
> > Cc: Joerg Roedel <joro@xxxxxxxxxx>
> > Cc: Will Deacon <will@xxxxxxxxxx>
> > Cc: Jiajun Cao <caojiajun@xxxxxxxxxx>
> > Cc: Robin Murphy <robin.murphy@xxxxxxx>
> > Cc: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
> > Cc: iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx
> > Cc: linux-kernel@xxxxxxxxxxxxxxx
> > Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>
> >
> > ---
> >
> > Changes from Robin's version:
> > * Added iommu_iotlb_gather_add_range() stub !CONFIG_IOMMU_API
> > * Use iommu_iotlb_gather_add_range() in iommu_iotlb_gather_add_page()
> > ---
> >   drivers/iommu/mtk_iommu.c |  5 +----
> >   include/linux/iommu.h     | 43 ++++++++++++++++++++++++++++++++++-----
> >   2 files changed, 39 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
> > index e06b8a0e2b56..0af4a91ac7da 100644
> > --- a/drivers/iommu/mtk_iommu.c
> > +++ b/drivers/iommu/mtk_iommu.c
> > @@ -523,10 +523,7 @@ static size_t mtk_iommu_unmap(struct iommu_domain *domain,
> >   	struct mtk_iommu_domain *dom = to_mtk_domain(domain);
> >   	unsigned long end = iova + size - 1;
>
> Please also help delete this "end".

Yes, that was part of my original patch - not sure what happened here :/

Robin.

> >   
> > -	if (gather->start > iova)
> > -		gather->start = iova;
> > -	if (gather->end < end)
> > -		gather->end = end;
> > +	iommu_iotlb_gather_add_range(gather, iova, size);
> >   	return dom->iop->unmap(dom->iop, iova, size, gather);
> >   }
>
> [snip]
>
>
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