--- zzzz-none-000/linux-3.10.107/arch/arm/include/asm/switch_to.h	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/arch/arm/include/asm/switch_to.h	2021-02-04 17:41:59.000000000 +0000
@@ -4,6 +4,18 @@
 #include <linux/thread_info.h>
 
 /*
+ * For v7 SMP cores running a preemptible kernel we may be pre-empted
+ * during a TLB maintenance operation, so execute an inner-shareable dsb
+ * to ensure that the maintenance completes in case we migrate to another
+ * CPU.
+ */
+#if defined(CONFIG_PREEMPT) && defined(CONFIG_SMP) && defined(CONFIG_CPU_V7)
+#define __complete_pending_tlbi()	dsb(ish)
+#else
+#define __complete_pending_tlbi()
+#endif
+
+/*
  * switch_to(prev, next) should switch from task `prev' to `next'
  * `prev' will never be the same as `next'.  schedule() itself
  * contains the memory barrier to tell GCC not to cache `current'.
@@ -12,6 +24,7 @@
 
 #define switch_to(prev,next,last)					\
 do {									\
+	__complete_pending_tlbi();					\
 	last = __switch_to(prev,task_thread_info(prev), task_thread_info(next));	\
 } while (0)