diff --git a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c
index 604c0e3bcc83..09408794eab2 100644
--- a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c
+++ b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c
@@ -431,11 +431,7 @@ static int pseudo_lock_fn(void *_rdtgrp)
 #else
 	register unsigned int line_size asm("esi");
 	register unsigned int size asm("edi");
-#ifdef CONFIG_X86_64
-	register void *mem_r asm("rbx");
-#else
-	register void *mem_r asm("ebx");
-#endif /* CONFIG_X86_64 */
+	register void *mem_r asm(_ASM_BX);
 #endif /* CONFIG_KASAN */
 
 	/*