v4.19.13 snapshot.
diff --git a/arch/um/os-Linux/time.c b/arch/um/os-Linux/time.c
new file mode 100644
index 0000000..0e39b99
--- /dev/null
+++ b/arch/um/os-Linux/time.c
@@ -0,0 +1,189 @@
+/*
+ * Copyright (C) 2015 Anton Ivanov (aivanov@{brocade.com,kot-begemot.co.uk})
+ * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
+ * Copyright (C) 2012-2014 Cisco Systems
+ * Copyright (C) 2000 - 2007 Jeff Dike (jdike{addtoit,linux.intel}.com)
+ * Licensed under the GPL
+ */
+
+#include <stddef.h>
+#include <errno.h>
+#include <signal.h>
+#include <time.h>
+#include <sys/time.h>
+#include <kern_util.h>
+#include <os.h>
+#include <string.h>
+#include <timer-internal.h>
+
+static timer_t event_high_res_timer = 0;
+
+static inline long long timeval_to_ns(const struct timeval *tv)
+{
+ return ((long long) tv->tv_sec * UM_NSEC_PER_SEC) +
+ tv->tv_usec * UM_NSEC_PER_USEC;
+}
+
+static inline long long timespec_to_ns(const struct timespec *ts)
+{
+ return ((long long) ts->tv_sec * UM_NSEC_PER_SEC) +
+ ts->tv_nsec;
+}
+
+long long os_persistent_clock_emulation (void) {
+ struct timespec realtime_tp;
+
+ clock_gettime(CLOCK_REALTIME, &realtime_tp);
+ return timespec_to_ns(&realtime_tp);
+}
+
+/**
+ * os_timer_create() - create an new posix (interval) timer
+ */
+int os_timer_create(void* timer) {
+
+ timer_t* t = timer;
+
+ if(t == NULL) {
+ t = &event_high_res_timer;
+ }
+
+ if (timer_create(
+ CLOCK_MONOTONIC,
+ NULL,
+ t) == -1) {
+ return -1;
+ }
+ return 0;
+}
+
+int os_timer_set_interval(void* timer, void* i)
+{
+ struct itimerspec its;
+ unsigned long long nsec;
+ timer_t* t = timer;
+ struct itimerspec* its_in = i;
+
+ if(t == NULL) {
+ t = &event_high_res_timer;
+ }
+
+ nsec = UM_NSEC_PER_SEC / UM_HZ;
+
+ if(its_in != NULL) {
+ its.it_value.tv_sec = its_in->it_value.tv_sec;
+ its.it_value.tv_nsec = its_in->it_value.tv_nsec;
+ } else {
+ its.it_value.tv_sec = 0;
+ its.it_value.tv_nsec = nsec;
+ }
+
+ its.it_interval.tv_sec = 0;
+ its.it_interval.tv_nsec = nsec;
+
+ if(timer_settime(*t, 0, &its, NULL) == -1) {
+ return -errno;
+ }
+
+ return 0;
+}
+
+/**
+ * os_timer_remain() - returns the remaining nano seconds of the given interval
+ * timer
+ * Because this is the remaining time of an interval timer, which correspondends
+ * to HZ, this value can never be bigger than one second. Just
+ * the nanosecond part of the timer is returned.
+ * The returned time is relative to the start time of the interval timer.
+ * Return an negative value in an error case.
+ */
+long os_timer_remain(void* timer)
+{
+ struct itimerspec its;
+ timer_t* t = timer;
+
+ if(t == NULL) {
+ t = &event_high_res_timer;
+ }
+
+ if(timer_gettime(t, &its) == -1) {
+ return -errno;
+ }
+
+ return its.it_value.tv_nsec;
+}
+
+int os_timer_one_shot(int ticks)
+{
+ struct itimerspec its;
+ unsigned long long nsec;
+ unsigned long sec;
+
+ nsec = (ticks + 1);
+ sec = nsec / UM_NSEC_PER_SEC;
+ nsec = nsec % UM_NSEC_PER_SEC;
+
+ its.it_value.tv_sec = nsec / UM_NSEC_PER_SEC;
+ its.it_value.tv_nsec = nsec;
+
+ its.it_interval.tv_sec = 0;
+ its.it_interval.tv_nsec = 0; // we cheat here
+
+ timer_settime(event_high_res_timer, 0, &its, NULL);
+ return 0;
+}
+
+/**
+ * os_timer_disable() - disable the posix (interval) timer
+ * Returns the remaining interval timer time in nanoseconds
+ */
+long long os_timer_disable(void)
+{
+ struct itimerspec its;
+
+ memset(&its, 0, sizeof(struct itimerspec));
+ timer_settime(event_high_res_timer, 0, &its, &its);
+
+ return its.it_value.tv_sec * UM_NSEC_PER_SEC + its.it_value.tv_nsec;
+}
+
+long long os_vnsecs(void)
+{
+ struct timespec ts;
+
+ clock_gettime(CLOCK_PROCESS_CPUTIME_ID,&ts);
+ return timespec_to_ns(&ts);
+}
+
+long long os_nsecs(void)
+{
+ struct timespec ts;
+
+ clock_gettime(CLOCK_MONOTONIC,&ts);
+ return timespec_to_ns(&ts);
+}
+
+/**
+ * os_idle_sleep() - sleep for a given time of nsecs
+ * @nsecs: nanoseconds to sleep
+ */
+void os_idle_sleep(unsigned long long nsecs)
+{
+ struct timespec ts;
+
+ if (nsecs <= 0) {
+ return;
+ }
+
+ ts = ((struct timespec) {
+ .tv_sec = nsecs / UM_NSEC_PER_SEC,
+ .tv_nsec = nsecs % UM_NSEC_PER_SEC
+ });
+
+ /*
+ * Relay the signal if clock_nanosleep is interrupted.
+ */
+ if (clock_nanosleep(CLOCK_MONOTONIC, 0, &ts, NULL)) {
+ deliver_alarm();
+ }
+}