1 files changed, 17 insertions, 39 deletions

diff --git a/mm/migrate.c b/mm/migrate.c
index e9594bc0d406..a42858d8e00b 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -246,8 +246,6 @@ static bool remove_migration_pte(struct page *page, struct vm_area_struct *vma,
 			if (is_device_private_page(new)) {
 				entry = make_device_private_entry(new, pte_write(pte));
 				pte = swp_entry_to_pte(entry);
-			} else if (is_device_public_page(new)) {
-				pte = pte_mkdevmap(pte);
 			}
 		}
 
@@ -381,7 +379,6 @@ static int expected_page_refs(struct address_space *mapping, struct page *page)
 	 * ZONE_DEVICE pages.
 	 */
 	expected_count += is_device_private_page(page);
-	expected_count += is_device_public_page(page);
 	if (mapping)
 		expected_count += hpage_nr_pages(page) + page_has_private(page);
 
@@ -397,8 +394,7 @@ static int expected_page_refs(struct address_space *mapping, struct page *page)
  * 3 for pages with a mapping and PagePrivate/PagePrivate2 set.
  */
 int migrate_page_move_mapping(struct address_space *mapping,
-		struct page *newpage, struct page *page, enum migrate_mode mode,
-		int extra_count)
+		struct page *newpage, struct page *page, int extra_count)
 {
 	XA_STATE(xas, &mapping->i_pages, page_index(page));
 	struct zone *oldzone, *newzone;
@@ -684,7 +680,7 @@ int migrate_page(struct address_space *mapping,
 
 	BUG_ON(PageWriteback(page));	/* Writeback must be complete */
 
-	rc = migrate_page_move_mapping(mapping, newpage, page, mode, 0);
+	rc = migrate_page_move_mapping(mapping, newpage, page, 0);
 
 	if (rc != MIGRATEPAGE_SUCCESS)
 		return rc;
@@ -771,19 +767,19 @@ recheck_buffers:
 			}
 			bh = bh->b_this_page;
 		} while (bh != head);
-		spin_unlock(&mapping->private_lock);
 		if (busy) {
 			if (invalidated) {
 				rc = -EAGAIN;
 				goto unlock_buffers;
 			}
+			spin_unlock(&mapping->private_lock);
 			invalidate_bh_lrus();
 			invalidated = true;
 			goto recheck_buffers;
 		}
 	}
 
-	rc = migrate_page_move_mapping(mapping, newpage, page, mode, 0);
+	rc = migrate_page_move_mapping(mapping, newpage, page, 0);
 	if (rc != MIGRATEPAGE_SUCCESS)
 		goto unlock_buffers;
 
@@ -809,6 +805,8 @@ recheck_buffers:
 
 	rc = MIGRATEPAGE_SUCCESS;
 unlock_buffers:
+	if (check_refs)
+		spin_unlock(&mapping->private_lock);
 	bh = head;
 	do {
 		unlock_buffer(bh);
@@ -994,10 +992,7 @@ static int move_to_new_page(struct page *newpage, struct page *page,
 		if (!PageMappingFlags(page))
 			page->mapping = NULL;
 
-		if (unlikely(is_zone_device_page(newpage))) {
-			if (is_device_public_page(newpage))
-				flush_dcache_page(newpage);
-		} else
+		if (likely(!is_zone_device_page(newpage)))
 			flush_dcache_page(newpage);
 
 	}
@@ -2265,7 +2260,7 @@ again:
 				pfn = 0;
 				goto next;
 			}
-			page = _vm_normal_page(migrate->vma, addr, pte, true);
+			page = vm_normal_page(migrate->vma, addr, pte);
 			mpfn = migrate_pfn(pfn) | MIGRATE_PFN_MIGRATE;
 			mpfn |= pte_write(pte) ? MIGRATE_PFN_WRITE : 0;
 		}
@@ -2345,16 +2340,13 @@ next:
 static void migrate_vma_collect(struct migrate_vma *migrate)
 {
 	struct mmu_notifier_range range;
-	struct mm_walk mm_walk;
-
-	mm_walk.pmd_entry = migrate_vma_collect_pmd;
-	mm_walk.pte_entry = NULL;
-	mm_walk.pte_hole = migrate_vma_collect_hole;
-	mm_walk.hugetlb_entry = NULL;
-	mm_walk.test_walk = NULL;
-	mm_walk.vma = migrate->vma;
-	mm_walk.mm = migrate->vma->vm_mm;
-	mm_walk.private = migrate;
+	struct mm_walk mm_walk = {
+		.pmd_entry = migrate_vma_collect_pmd,
+		.pte_hole = migrate_vma_collect_hole,
+		.vma = migrate->vma,
+		.mm = migrate->vma->vm_mm,
+		.private = migrate,
+	};
 
 	mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, NULL, mm_walk.mm,
 				migrate->start,
@@ -2406,16 +2398,7 @@ static bool migrate_vma_check_page(struct page *page)
 		 * FIXME proper solution is to rework migration_entry_wait() so
 		 * it does not need to take a reference on page.
 		 */
-		if (is_device_private_page(page))
-			return true;
-
-		/*
-		 * Only allow device public page to be migrated and account for
-		 * the extra reference count imply by ZONE_DEVICE pages.
-		 */
-		if (!is_device_public_page(page))
-			return false;
-		extra++;
+		return is_device_private_page(page);
 	}
 
 	/* For file back page */
@@ -2665,11 +2648,6 @@ static void migrate_vma_insert_page(struct migrate_vma *migrate,
 
 			swp_entry = make_device_private_entry(page, vma->vm_flags & VM_WRITE);
 			entry = swp_entry_to_pte(swp_entry);
-		} else if (is_device_public_page(page)) {
-			entry = pte_mkold(mk_pte(page, READ_ONCE(vma->vm_page_prot)));
-			if (vma->vm_flags & VM_WRITE)
-				entry = pte_mkwrite(pte_mkdirty(entry));
-			entry = pte_mkdevmap(entry);
 		}
 	} else {
 		entry = mk_pte(page, vma->vm_page_prot);
@@ -2789,7 +2767,7 @@ static void migrate_vma_pages(struct migrate_vma *migrate)
 					migrate->src[i] &= ~MIGRATE_PFN_MIGRATE;
 					continue;
 				}
-			} else if (!is_device_public_page(newpage)) {
+			} else {
 				/*
 				 * Other types of ZONE_DEVICE page are not
 				 * supported.