diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
index 610c11e..824d117 100644
--- a/arch/riscv/kernel/process.c
+++ b/arch/riscv/kernel/process.c
@@ -22,7 +22,7 @@
 #include <asm/switch_to.h>
 #include <asm/thread_info.h>
 
-unsigned long gp_in_global __asm__("gp");
+register unsigned long gp_in_global __asm__("gp");
 
 extern asmlinkage void ret_from_fork(void);
 extern asmlinkage void ret_from_kernel_thread(void);
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 27a3341..736de6c 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -47,7 +47,7 @@
 	memset((void *)empty_zero_page, 0, PAGE_SIZE);
 }
 
-#ifdef CONFIG_DEBUG_VM
+#if defined(CONFIG_MMU) && defined(CONFIG_DEBUG_VM)
 static inline void print_mlk(char *name, unsigned long b, unsigned long t)
 {
 	pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld kB)\n", name, b, t,