diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index f497ca77925a..61599b516c66 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -109,9 +109,11 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max)
 }
 
 #ifdef CONFIG_HAVE_ARCH_PFN_VALID
+#define PFN_MASK ((1UL << (64 - PAGE_SHIFT)) - 1)
+
 int pfn_valid(unsigned long pfn)
 {
-	return memblock_is_memory(pfn << PAGE_SHIFT);
+	return (pfn & PFN_MASK) == pfn && memblock_is_memory(pfn << PAGE_SHIFT);
 }
 EXPORT_SYMBOL(pfn_valid);
 #endif