v4.19.13 snapshot.
diff --git a/include/linux/bottom_half.h b/include/linux/bottom_half.h
new file mode 100644
index 0000000..a19519f
--- /dev/null
+++ b/include/linux/bottom_half.h
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_BH_H
+#define _LINUX_BH_H
+
+#include <linux/preempt.h>
+
+#ifdef CONFIG_TRACE_IRQFLAGS
+extern void __local_bh_disable_ip(unsigned long ip, unsigned int cnt);
+#else
+static __always_inline void __local_bh_disable_ip(unsigned long ip, unsigned int cnt)
+{
+ preempt_count_add(cnt);
+ barrier();
+}
+#endif
+
+static inline void local_bh_disable(void)
+{
+ __local_bh_disable_ip(_THIS_IP_, SOFTIRQ_DISABLE_OFFSET);
+}
+
+extern void _local_bh_enable(void);
+extern void __local_bh_enable_ip(unsigned long ip, unsigned int cnt);
+
+static inline void local_bh_enable_ip(unsigned long ip)
+{
+ __local_bh_enable_ip(ip, SOFTIRQ_DISABLE_OFFSET);
+}
+
+static inline void local_bh_enable(void)
+{
+ __local_bh_enable_ip(_THIS_IP_, SOFTIRQ_DISABLE_OFFSET);
+}
+
+#endif /* _LINUX_BH_H */