[PATCH v12 02/31] iommu/exynos: add missing cache flush for removed page table entries

From: Shaik Ameer Basha
Date: Sun Apr 27 2014 - 03:46:24 EST


From: Cho KyongHo <pullip.cho@xxxxxxxxxxx>

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.

Reviewed-by: Tomasz Figa <t.figa@xxxxxxxxxxx>
Tested-by: Grant Grundler <grundler@xxxxxxxxxxxx>
Signed-off-by: Cho KyongHo <pullip.cho@xxxxxxxxxxx>
---
drivers/iommu/exynos-iommu.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
index 46f0ca1..34e4273 100644
--- a/drivers/iommu/exynos-iommu.c
+++ b/drivers/iommu/exynos-iommu.c
@@ -957,6 +957,7 @@ 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;
}
@@ -965,6 +966,7 @@ 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;
--
1.7.9.5

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