x86/amd-iommu: Use fetch_pte in amd_iommu_iova_to_phys

Don't reimplement the page table walker in this function.
Use the generic one.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

arch/x86/kernel/amd_iommu.c

@@ -2140,21 +2140,9 @@ static phys_addr_t amd_iommu_iova_to_phys(struct iommu_domain *dom,
 	phys_addr_t paddr;
 	u64 *pte;
 
-	pte = &domain->pt_root[IOMMU_PTE_L2_INDEX(iova)];
+	pte = fetch_pte(domain, iova);
 
-	if (!IOMMU_PTE_PRESENT(*pte))
-		return 0;
-
-	pte = IOMMU_PTE_PAGE(*pte);
-	pte = &pte[IOMMU_PTE_L1_INDEX(iova)];
-
-	if (!IOMMU_PTE_PRESENT(*pte))
-		return 0;
-
-	pte = IOMMU_PTE_PAGE(*pte);
-	pte = &pte[IOMMU_PTE_L0_INDEX(iova)];
-
-	if (!IOMMU_PTE_PRESENT(*pte))
+	if (!pte || !IOMMU_PTE_PRESENT(*pte))
 		return 0;
 
 	paddr  = *pte & IOMMU_PAGE_MASK;