1 files changed, 2 insertions, 2 deletions

diff --git a/kernel/resource.c b/kernel/resource.c
index 74877e9d90ca..76036a41143b 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -487,8 +487,8 @@ int walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
         while (start < end &&
                !find_next_iomem_res(start, end, flags, IORES_DESC_NONE,
                                     false, &res)) {
-                pfn = (res.start + PAGE_SIZE - 1) >> PAGE_SHIFT;
-                end_pfn = (res.end + 1) >> PAGE_SHIFT;
+                pfn = PFN_UP(res.start);
+                end_pfn = PFN_DOWN(res.end + 1);
                 if (end_pfn > pfn)
                         ret = (*func)(pfn, end_pfn - pfn, arg);
                 if (ret)