There are some issues in pgtable_walk():

1. Super page is dumped as non-present page
2. dma_pte_superpage() should not check against leaf page table entries
3. Pointer pte is never NULL so checking it is meaningless

Fix it by moving the check of super page after (level == 1) check and
removing pte check.

Fixes: 914ff7719e8a ("iommu/vt-d: Dump DMAR translation structure when DMA fault occurs")
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
---
 drivers/iommu/intel/iommu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 8288b0ee7a61..fec5cc1147f3 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -707,14 +707,14 @@ static void pgtable_walk(struct intel_iommu *iommu, unsigned long pfn,
 	while (1) {
 		offset = pfn_level_offset(pfn, level);
 		pte = &parent[offset];
-		if (!pte || (dma_pte_superpage(pte) || !dma_pte_present(pte))) {
+		if (!dma_pte_present(pte)) {
 			pr_info("PTE not present at level %d\n", level);
 			break;
 		}
 
 		pr_info("pte level: %d, pte value: 0x%016llx\n", level, pte->val);
 
-		if (level == 1)
+		if (level == 1 || dma_pte_superpage(pte))
 			break;
 
 		parent = phys_to_virt(dma_pte_addr(pte));
-- 
2.34.1