From: Felix Fietkau <nbd@openwrt.org>
Date: Tue, 19 Jan 2016 00:18:09 +0100
Subject: [PATCH] ARM: work around CONFIG_CPU_SW_DOMAIN_PAN breakage on ARM11
 MPCore

Patch taken from http://www.spinics.net/lists/arm-kernel/msg450888.html

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
---

--- a/arch/arm/kernel/smp_tlb.c
+++ b/arch/arm/kernel/smp_tlb.c
@@ -9,6 +9,7 @@
  */
 #include <linux/preempt.h>
 #include <linux/smp.h>
+#include <linux/uaccess.h>
 
 #include <asm/smp_plat.h>
 #include <asm/tlbflush.h>
@@ -40,8 +41,11 @@ static inline void ipi_flush_tlb_mm(void
 static inline void ipi_flush_tlb_page(void *arg)
 {
 	struct tlb_args *ta = (struct tlb_args *)arg;
+	unsigned int __ua_flags = uaccess_save_and_enable();
 
 	local_flush_tlb_page(ta->ta_vma, ta->ta_start);
+
+	uaccess_restore(__ua_flags);
 }
 
 static inline void ipi_flush_tlb_kernel_page(void *arg)
@@ -54,8 +58,11 @@ static inline void ipi_flush_tlb_kernel_
 static inline void ipi_flush_tlb_range(void *arg)
 {
 	struct tlb_args *ta = (struct tlb_args *)arg;
+	unsigned int __ua_flags = uaccess_save_and_enable();
 
 	local_flush_tlb_range(ta->ta_vma, ta->ta_start, ta->ta_end);
+
+	uaccess_restore(__ua_flags);
 }
 
 static inline void ipi_flush_tlb_kernel_range(void *arg)