likely(is_swap_pmd(pmd))) {
-		swp_entry_t entry = pmd_to_swp_entry(pmd);
-
-		VM_WARN_ON(!is_pmd_non_present_folio_entry(pmd));
-
-		if (is_writable_migration_entry(entry) ||
-		    is_readable_exclusive_migration_entry(entry)) {
-			entry = make_readable_migration_entry(swp_offset(entry));
-			pmd = swp_entry_to_pmd(entry);
-			if (pmd_swp_soft_dirty(*src_pmd))
-				pmd = pmd_swp_mksoft_dirty(pmd);
-			if (pmd_swp_uffd_wp(*src_pmd))
-				pmd = pmd_swp_mkuffd_wp(pmd);
-			set_pmd_at(src_mm, addr, src_pmd, pmd);
-		} else if (is_device_private_entry(entry)) {
-			/*
-			 * For device private entries, since there are no
-			 * read exclusive entries, writable = !readable
-			 */
-			if (is_writable_device_private_entry(entry)) {
-				entry = make_readable_device_private_entry(swp_offset(entry));
-				pmd = swp_entry_to_pmd(entry);
-
-				if (pmd_swp_soft_dirty(*src_pmd))
-					pmd = pmd_swp_mksoft_dirty(pmd);
-				if (pmd_swp_uffd_wp(*src_pmd))
-					pmd = pmd_swp_mkuffd_wp(pmd);
-				set_pmd_at(src_mm, addr, src_pmd, pmd);
-			}
-
-			src_folio = pfn_swap_entry_folio(entry);
-			VM_WARN_ON(!folio_test_large(src_folio));
-
-			folio_get(src_folio);
-			/*
-			 * folio_try_dup_anon_rmap_pmd does not fail for
-			 * device private entries.
-			 */
-			folio_try_dup_anon_rmap_pmd(src_folio, &src_folio->page,
-							dst_vma, src_vma);
-		}
-
-		add_mm_counter(dst_mm, MM_ANONPAGES, HPAGE_PMD_NR);
-		mm_inc_nr_ptes(dst_mm);
-		pgtable_trans_huge_deposit(dst_mm, dst_pmd, pgtable);
-		if (!userfaultfd_wp(dst_vma))
-			pmd = pmd_swp_clear_uffd_wp(pmd);
-		set_pmd_at(dst_mm, addr, dst_pmd, pmd);
+	if (unlikely(thp_migration_supported() && is_swap_pmd(pmd))) {
+		copy_huge_non_present_pmd(dst_mm, src_mm, dst_pmd, src_pmd, addr,
+					  dst_vma, src_vma, pmd, pgtable);
 		ret = 0;
 		goto out_unlock;
 	}
-#endif
 
 	if (unlikely(!pmd_trans_huge(pmd))) {
 		pte_free(dst_mm, pgtable);
-- 
2.51.0[RFC PATCH 08/12] mm/huge_memory: refactor copy_huge_pmd() non-present logicLorenzo Stoakes <lorenzo.stoakes@oracle.com> undefinedAndrew Morton <akpm@linux-foundation.org> undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined‹bƒÃd