diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 878a5b926fe5..1f79daa5f4b1 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -1700,13 +1700,12 @@ static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu)
 	id = readl_relaxed(gr0_base + ARM_SMMU_GR0_ID1);
 	smmu->pagesize = (id & ID1_PAGESIZE) ? SZ_64K : SZ_4K;
 
-	/* Check that we ioremapped enough */
+	/* Check for size mismatch of SMMU address space from mapped region */
 	size = 1 << (((id >> ID1_NUMPAGENDXB_SHIFT) & ID1_NUMPAGENDXB_MASK) + 1);
 	size *= (smmu->pagesize << 1);
-	if (smmu->size < size)
-		dev_warn(smmu->dev,
-			 "device is 0x%lx bytes but only mapped 0x%lx!\n",
-			 size, smmu->size);
+	if (smmu->size != size)
+		dev_warn(smmu->dev, "SMMU address space size (0x%lx) differs "
+			"from mapped region size (0x%lx)!\n", size, smmu->size);
 
 	smmu->num_s2_context_banks = (id >> ID1_NUMS2CB_SHIFT) &
 				      ID1_NUMS2CB_MASK;