Re: [PATCH v9 02/16] iommu/exynos: add missing cache flush for removed page table entries

[Cho KyongHo <pullip.cho@samsung.com>]

On Thu, 08 Aug 2013 15:44:09 +0200, Tomasz Figa wrote:
> On Thursday 08 of August 2013 18:37:34 Cho KyongHo wrote:
> > This commit adds cache flush for removed small and large page entries
> > in exynos_iommu_unmap(). Missing cache flush of removed page table
> > entries can cause missing page fault interrupt when a master IP
> > accesses an unmapped area.
> > 
> > Tested-by: Grant Grundler <grundler@chromium.org>
> > Signed-off-by: Cho KyongHo <pullip.cho@samsung.com>
> > ---
> >  drivers/iommu/exynos-iommu.c |    2 ++
> >  1 files changed, 2 insertions(+), 0 deletions(-)
> > 
> > diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
> > index 233f382..d545a25 100644
> > --- a/drivers/iommu/exynos-iommu.c
> > +++ b/drivers/iommu/exynos-iommu.c
> > @@ -1002,6 +1002,7 @@ static size_t exynos_iommu_unmap(struct
> > iommu_domain *domain, if (lv2ent_small(ent)) {
> >  		*ent = 0;
> >  		size = SPAGE_SIZE;
> > +		pgtable_flush(ent, ent + 1);
> >  		priv->lv2entcnt[lv1ent_offset(iova)] += 1;
> >  		goto done;
> >  	}
> > @@ -1010,6 +1011,7 @@ static size_t exynos_iommu_unmap(struct
> > iommu_domain *domain, BUG_ON(size < LPAGE_SIZE);
> > 
> >  	memset(ent, 0, sizeof(*ent) * SPAGES_PER_LPAGE);
> > +	pgtable_flush(ent, ent + SPAGES_PER_LPAGE);
> > 
> >  	size = LPAGE_SIZE;
> >  	priv->lv2entcnt[lv1ent_offset(iova)] += SPAGES_PER_LPAGE;
> 
> Looks reasonable.
> 
> Reviewed-by: Tomasz Figa <t.figa@samsung.com>
> 

Thanks.

KyongHo.
> Best regards,
> Tomasz
>