v4.19.13 snapshot.
diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h
new file mode 100644
index 0000000..8d9a0ea
--- /dev/null
+++ b/include/linux/rcutiny.h
@@ -0,0 +1,137 @@
+/*
+ * Read-Copy Update mechanism for mutual exclusion, the Bloatwatch edition.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, you can access it online at
+ * http://www.gnu.org/licenses/gpl-2.0.html.
+ *
+ * Copyright IBM Corporation, 2008
+ *
+ * Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
+ *
+ * For detailed explanation of Read-Copy Update mechanism see -
+ * Documentation/RCU
+ */
+#ifndef __LINUX_TINY_H
+#define __LINUX_TINY_H
+
+#include <linux/ktime.h>
+
+struct rcu_dynticks;
+static inline int rcu_dynticks_snap(struct rcu_dynticks *rdtp)
+{
+ return 0;
+}
+
+/* Never flag non-existent other CPUs! */
+static inline bool rcu_eqs_special_set(int cpu) { return false; }
+
+static inline unsigned long get_state_synchronize_rcu(void)
+{
+ return 0;
+}
+
+static inline void cond_synchronize_rcu(unsigned long oldstate)
+{
+ might_sleep();
+}
+
+static inline unsigned long get_state_synchronize_sched(void)
+{
+ return 0;
+}
+
+static inline void cond_synchronize_sched(unsigned long oldstate)
+{
+ might_sleep();
+}
+
+extern void rcu_barrier_bh(void);
+extern void rcu_barrier_sched(void);
+
+static inline void synchronize_rcu_expedited(void)
+{
+ synchronize_sched(); /* Only one CPU, so pretty fast anyway!!! */
+}
+
+static inline void rcu_barrier(void)
+{
+ rcu_barrier_sched(); /* Only one CPU, so only one list of callbacks! */
+}
+
+static inline void synchronize_rcu_bh(void)
+{
+ synchronize_sched();
+}
+
+static inline void synchronize_rcu_bh_expedited(void)
+{
+ synchronize_sched();
+}
+
+static inline void synchronize_sched_expedited(void)
+{
+ synchronize_sched();
+}
+
+static inline void kfree_call_rcu(struct rcu_head *head,
+ rcu_callback_t func)
+{
+ call_rcu(head, func);
+}
+
+#define rcu_note_context_switch(preempt) \
+ do { \
+ rcu_sched_qs(); \
+ rcu_tasks_qs(current); \
+ } while (0)
+
+static inline int rcu_needs_cpu(u64 basemono, u64 *nextevt)
+{
+ *nextevt = KTIME_MAX;
+ return 0;
+}
+
+/*
+ * Take advantage of the fact that there is only one CPU, which
+ * allows us to ignore virtualization-based context switches.
+ */
+static inline void rcu_virt_note_context_switch(int cpu) { }
+static inline void rcu_cpu_stall_reset(void) { }
+static inline void rcu_idle_enter(void) { }
+static inline void rcu_idle_exit(void) { }
+static inline void rcu_irq_enter(void) { }
+static inline void rcu_irq_exit_irqson(void) { }
+static inline void rcu_irq_enter_irqson(void) { }
+static inline void rcu_irq_exit(void) { }
+static inline void exit_rcu(void) { }
+#ifdef CONFIG_SRCU
+void rcu_scheduler_starting(void);
+#else /* #ifndef CONFIG_SRCU */
+static inline void rcu_scheduler_starting(void) { }
+#endif /* #else #ifndef CONFIG_SRCU */
+static inline void rcu_end_inkernel_boot(void) { }
+static inline bool rcu_is_watching(void) { return true; }
+
+/* Avoid RCU read-side critical sections leaking across. */
+static inline void rcu_all_qs(void) { barrier(); }
+
+/* RCUtree hotplug events */
+#define rcutree_prepare_cpu NULL
+#define rcutree_online_cpu NULL
+#define rcutree_offline_cpu NULL
+#define rcutree_dead_cpu NULL
+#define rcutree_dying_cpu NULL
+static inline void rcu_cpu_starting(unsigned int cpu) { }
+
+#endif /* __LINUX_RCUTINY_H */