diff --git a/arch/openrisc/kernel/smp.c b/arch/openrisc/kernel/smp.c
index 7d518ee8bddc..bd1e660bbc89 100644
--- a/arch/openrisc/kernel/smp.c
+++ b/arch/openrisc/kernel/smp.c
@@ -14,6 +14,7 @@
 #include <linux/smp.h>
 #include <linux/cpu.h>
 #include <linux/sched.h>
+#include <linux/sched/mm.h>
 #include <linux/irq.h>
 #include <asm/cpuinfo.h>
 #include <asm/mmu_context.h>
@@ -113,7 +114,7 @@ asmlinkage __init void secondary_start_kernel(void)
 	 * All kernel threads share the same mm context; grab a
 	 * reference and switch to it.
 	 */
-	atomic_inc(&mm->mm_count);
+	mmgrab(mm);
 	current->active_mm = mm;
 	cpumask_set_cpu(cpu, mm_cpumask(mm));