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

[Tomasz Figa]

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@xxxxxxxxxxxx>
> Signed-off-by: Cho KyongHo <pullip.cho@xxxxxxxxxxx>
> ---
>  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@xxxxxxxxxxx>

Best regards,
Tomasz

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