v4.19.13 snapshot.
diff --git a/arch/riscv/kernel/time.c b/arch/riscv/kernel/time.c
new file mode 100644
index 0000000..1911c8f
--- /dev/null
+++ b/arch/riscv/kernel/time.c
@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2012 Regents of the University of California
+ * Copyright (C) 2017 SiFive
+ *
+ * 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, version 2.
+ *
+ * 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.
+ */
+
+#include <linux/clocksource.h>
+#include <linux/delay.h>
+#include <asm/sbi.h>
+
+unsigned long riscv_timebase;
+
+void __init time_init(void)
+{
+ struct device_node *cpu;
+ u32 prop;
+
+ cpu = of_find_node_by_path("/cpus");
+ if (!cpu || of_property_read_u32(cpu, "timebase-frequency", &prop))
+ panic(KERN_WARNING "RISC-V system with no 'timebase-frequency' in DTS\n");
+ riscv_timebase = prop;
+
+ lpj_fine = riscv_timebase / HZ;
+ timer_probe();
+}