v4.19.13 snapshot.
diff --git a/arch/arm/kernel/time.c b/arch/arm/kernel/time.c
new file mode 100644
index 0000000..078b259
--- /dev/null
+++ b/arch/arm/kernel/time.c
@@ -0,0 +1,114 @@
+/*
+ * linux/arch/arm/kernel/time.c
+ *
+ * Copyright (C) 1991, 1992, 1995 Linus Torvalds
+ * Modifications for ARM (C) 1994-2001 Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This file contains the ARM-specific time handling details:
+ * reading the RTC at bootup, etc...
+ */
+#include <linux/clk-provider.h>
+#include <linux/clocksource.h>
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/profile.h>
+#include <linux/sched.h>
+#include <linux/sched_clock.h>
+#include <linux/smp.h>
+#include <linux/time.h>
+#include <linux/timex.h>
+#include <linux/timer.h>
+
+#include <asm/mach/arch.h>
+#include <asm/mach/time.h>
+#include <asm/stacktrace.h>
+#include <asm/thread_info.h>
+
+#if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) || \
+ defined(CONFIG_NVRAM) || defined(CONFIG_NVRAM_MODULE)
+/* this needs a better home */
+DEFINE_SPINLOCK(rtc_lock);
+EXPORT_SYMBOL(rtc_lock);
+#endif /* pc-style 'CMOS' RTC support */
+
+/* change this if you have some constant time drift */
+#define USECS_PER_JIFFY (1000000/HZ)
+
+#ifdef CONFIG_SMP
+unsigned long profile_pc(struct pt_regs *regs)
+{
+ struct stackframe frame;
+
+ if (!in_lock_functions(regs->ARM_pc))
+ return regs->ARM_pc;
+
+ arm_get_current_stackframe(regs, &frame);
+ do {
+ int ret = unwind_frame(&frame);
+ if (ret < 0)
+ return 0;
+ } while (in_lock_functions(frame.pc));
+
+ return frame.pc;
+}
+EXPORT_SYMBOL(profile_pc);
+#endif
+
+#ifndef CONFIG_GENERIC_CLOCKEVENTS
+/*
+ * Kernel system timer support.
+ */
+void timer_tick(void)
+{
+ profile_tick(CPU_PROFILING);
+ xtime_update(1);
+#ifndef CONFIG_SMP
+ update_process_times(user_mode(get_irq_regs()));
+#endif
+}
+#endif
+
+static void dummy_clock_access(struct timespec64 *ts)
+{
+ ts->tv_sec = 0;
+ ts->tv_nsec = 0;
+}
+
+static clock_access_fn __read_persistent_clock = dummy_clock_access;
+
+void read_persistent_clock64(struct timespec64 *ts)
+{
+ __read_persistent_clock(ts);
+}
+
+int __init register_persistent_clock(clock_access_fn read_persistent)
+{
+ /* Only allow the clockaccess functions to be registered once */
+ if (__read_persistent_clock == dummy_clock_access) {
+ if (read_persistent)
+ __read_persistent_clock = read_persistent;
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+void __init time_init(void)
+{
+ if (machine_desc->init_time) {
+ machine_desc->init_time();
+ } else {
+#ifdef CONFIG_COMMON_CLK
+ of_clk_init(NULL);
+#endif
+ timer_probe();
+ }
+}