diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 1b1378619fc9ec2f0caa0bbbd262192c21de61e4..ff40ba758cf365e89ddeb2270971e1536554b817 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -359,7 +359,7 @@ static void iommu_write_l2(struct amd_iommu *iommu, u8 address, u32 val)
 static void iommu_set_exclusion_range(struct amd_iommu *iommu)
 {
 	u64 start = iommu->exclusion_start & PAGE_MASK;
-	u64 limit = (start + iommu->exclusion_length) & PAGE_MASK;
+	u64 limit = (start + iommu->exclusion_length - 1) & PAGE_MASK;
 	u64 entry;
 
 	if (!iommu->exclusion_start)