iommu/amd: Restart loop if cmpxchg64 succeeded in alloc_pte()

This makes sure that __pte always contains the correct value
when the pointer to the next page-table level is derived.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

drivers/iommu/amd_iommu.c

@@ -1474,13 +1474,12 @@ static u64 *alloc_pte(struct protection_domain *domain,
 			__npte = PM_LEVEL_PDE(level, iommu_virt_to_phys(page));
 
 			/* pte could have been changed somewhere. */
-			if (cmpxchg64(pte, __pte, __npte) != __pte) {
+			if (cmpxchg64(pte, __pte, __npte) != __pte)
 				free_page((unsigned long)page);
-				continue;
-			}
-
-			if (pte_level == PAGE_MODE_7_LEVEL)
+			else if (pte_level == PAGE_MODE_7_LEVEL)
 				domain->updated = true;
+
+			continue;
 		}
 
 		/* No level skipping support yet */
@@ -1489,7 +1488,7 @@ static u64 *alloc_pte(struct protection_domain *domain,
 
 		level -= 1;
 
-		pte = IOMMU_PTE_PAGE(*pte);
+		pte = IOMMU_PTE_PAGE(__pte);
 
 		if (pte_page && level == end_lvl)
 			*pte_page = pte;