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: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 6a88ba9..c539b2a 100644 (file)
--- a/drivers/iommu/amd_iommu.c
+++ b/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;