2013-08-08 09:37:52

by Cho KyongHo

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

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 <[email protected]>
Signed-off-by: Cho KyongHo <[email protected]>
---
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;
--
1.7.2.5

2013-08-08 13:44:16

by Tomasz Figa

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

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 <[email protected]>
> Signed-off-by: Cho KyongHo <[email protected]>
> ---
> 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 <[email protected]>

Best regards,
Tomasz

2013-08-09 04:02:17

by Cho KyongHo

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

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 <[email protected]>
> > Signed-off-by: Cho KyongHo <[email protected]>
> > ---
> > 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 <[email protected]>
>

Thanks.

KyongHo.
> Best regards,
> Tomasz
>