Merge "These changes are a raw update to a vanilla kernel 4.1.10, with the recently announced rt patch patch-4.1.10-rt10.patch. No further changes needed."

1 files changed, 16 insertions, 1 deletions

diff --git a/kernel/drivers/iommu/io-pgtable-arm.c b/kernel/drivers/iommu/io-pgtable-arm.c
index 4e460216b..e29d5d7fe 100644
--- a/kernel/drivers/iommu/io-pgtable-arm.c
+++ b/kernel/drivers/iommu/io-pgtable-arm.c
@@ -200,6 +200,10 @@ typedef u64 arm_lpae_iopte;
 
 static bool selftest_running = false;
 
+static int __arm_lpae_unmap(struct arm_lpae_io_pgtable *data,
+			    unsigned long iova, size_t size, int lvl,
+			    arm_lpae_iopte *ptep);
+
 static int arm_lpae_init_pte(struct arm_lpae_io_pgtable *data,
 			     unsigned long iova, phys_addr_t paddr,
 			     arm_lpae_iopte prot, int lvl,
@@ -207,10 +211,21 @@ static int arm_lpae_init_pte(struct arm_lpae_io_pgtable *data,
 {
 	arm_lpae_iopte pte = prot;
 
-	/* We require an unmap first */
 	if (iopte_leaf(*ptep, lvl)) {
+		/* We require an unmap first */
 		WARN_ON(!selftest_running);
 		return -EEXIST;
+	} else if (iopte_type(*ptep, lvl) == ARM_LPAE_PTE_TYPE_TABLE) {
+		/*
+		 * We need to unmap and free the old table before
+		 * overwriting it with a block entry.
+		 */
+		arm_lpae_iopte *tblp;
+		size_t sz = ARM_LPAE_BLOCK_SIZE(lvl, data);
+
+		tblp = ptep - ARM_LPAE_LVL_IDX(iova, lvl, data);
+		if (WARN_ON(__arm_lpae_unmap(data, iova, sz, lvl, tblp) != sz))
+			return -EINVAL;
 	}
 
 	if (data->iop.cfg.quirks & IO_PGTABLE_QUIRK_ARM_NS)