mm/migrate: support un-addressable ZONE_DEVICE page in migration

[sfrench/cifs-2.6.git] / mm / page_vma_mapped.c

diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c
index 3bd3008db4cb39017feef01061d3f92149bd9c0e..6a03946469a99eb535851194f519893a5e8a2d11 100644 (file)
--- a/mm/page_vma_mapped.c
+++ b/mm/page_vma_mapped.c
@@ -48,6 +48,7 @@ static bool check_pte(struct page_vma_mapped_walk *pvmw)
                if (!is_swap_pte(*pvmw->pte))
                        return false;
                entry = pte_to_swp_entry(*pvmw->pte);
+
                if (!is_migration_entry(entry))
                        return false;
                if (migration_entry_to_page(entry) - pvmw->page >=
@@ -60,6 +61,15 @@ static bool check_pte(struct page_vma_mapped_walk *pvmw)
                WARN_ON_ONCE(1);
 #endif
        } else {
+               if (is_swap_pte(*pvmw->pte)) {
+                       swp_entry_t entry;
+
+                       entry = pte_to_swp_entry(*pvmw->pte);
+                       if (is_device_private_entry(entry) &&
+                           device_private_entry_to_page(entry) == pvmw->page)
+                               return true;
+               }
+
                if (!pte_present(*pvmw->pte))
                        return false;