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.
Reviewed-by: NTomasz Figa <t.figa@samsung.com>
Tested-by: NGrant Grundler <grundler@chromium.org>
Signed-off-by: NCho KyongHo <pullip.cho@samsung.com>
Signed-off-by: NShaik Ameer Basha <shaik.ameer@samsung.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

drivers/iommu/exynos-iommu.c

@@ -904,6 +904,7 @@ 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;
 	}
@@ -915,6 +916,7 @@ static size_t exynos_iommu_unmap(struct iommu_domain *domain,
 	}
 
 	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;