diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index aca924a..83ed74a 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -22,13 +22,17 @@
 #include <asm/pgalloc.h>
 #include <asm/pat.h>
 
-#ifdef CONFIG_X86_64
-
-static inline int phys_addr_valid(unsigned long addr)
+static inline int phys_addr_valid(resource_size_t addr)
 {
-	return addr < (1UL << boot_cpu_data.x86_phys_bits);
+#ifdef CONFIG_PHYS_ADDR_T_64BIT
+	return !(addr >> boot_cpu_data.x86_phys_bits);
+#else
+	return 1;
+#endif
 }
 
+#ifdef CONFIG_X86_64
+
 unsigned long __phys_addr(unsigned long x)
 {
 	if (x >= __START_KERNEL_map) {
@@ -65,11 +69,6 @@
 
 #else
 
-static inline int phys_addr_valid(unsigned long addr)
-{
-	return 1;
-}
-
 #ifdef CONFIG_DEBUG_VIRTUAL
 unsigned long __phys_addr(unsigned long x)
 {