On Fri, Jul 26, 2013 at 4:26 AM, Cho KyongHo <pullip.cho@xxxxxxxxxxx> 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.
>
> Signed-off-by: Cho KyongHo <pullip.cho@xxxxxxxxxxx>
Tested-by: Grant Grundler <grundler@xxxxxxxxxxxx>
I'm convinced this is a critical fix to apply. Any time we touch the
IOMMU Page Table, we need to flush so the change is immediately
visible to the IOMMU.
thanks,
grant
> ---
> 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..e3be3e5 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
>
>
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