diff --git a/drivers/timers/arch_alarm.c b/drivers/timers/arch_alarm.c
index 22c9a275bcf..731a05e6c45 100644
--- a/drivers/timers/arch_alarm.c
+++ b/drivers/timers/arch_alarm.c
@@ -392,6 +392,47 @@ int up_alarm_start(FAR const struct timespec *ts)
 }
 #endif
 
+/********************************************************************************
+ * Name: up_critmon_*
+ *
+ * Description:
+ *   The first interface simply provides the current time value in unknown
+ *   units.  NOTE:  This function may be called early before the timer has
+ *   been initialized.  In that event, the function should just return a
+ *   start time of zero.
+ *
+ *   Nothing is assumed about the units of this time value.  The following
+ *   are assumed, however: (1) The time is an unsigned integer value, (2)
+ *   the time is monotonically increasing, and (3) the elapsed time (also
+ *   in unknown units) can be obtained by subtracting a start time from
+ *   the current time.
+ *
+ *   The second interface simple converts an elapsed time into well known
+ *   units.
+ ********************************************************************************/
+
+#ifdef CONFIG_SCHED_CRITMONITOR
+uint32_t up_critmon_gettime(void)
+{
+  uint32_t ret = 0;
+
+  if (g_oneshot_lower != NULL)
+    {
+      struct timespec ts;
+
+      ONESHOT_CURRENT(g_oneshot_lower, &ts);
+      ret = timespec_to_usec(&ts);
+    }
+
+  return ret;
+}
+
+void up_critmon_convert(uint32_t elapsed, FAR struct timespec *ts)
+{
+  timespec_from_usec(ts, elapsed);
+}
+#endif
+
 /****************************************************************************
  * Name: up_mdelay
  *
diff --git a/drivers/timers/arch_timer.c b/drivers/timers/arch_timer.c
index 75fe6864fd2..9d38ae4f6a2 100644
--- a/drivers/timers/arch_timer.c
+++ b/drivers/timers/arch_timer.c
@@ -91,12 +91,8 @@ static struct arch_timer_s g_timer;
  * Private Functions
  ****************************************************************************/
 
-#ifdef CONFIG_SCHED_TICKLESS
-static inline uint64_t timespec_to_usec(const FAR struct timespec *ts)
-{
-  return (uint64_t)ts->tv_sec * USEC_PER_SEC + ts->tv_nsec / NSEC_PER_USEC;
-}
-
+#if defined(CONFIG_SCHED_TICKLESS) || defined(CONFIG_SCHED_CRITMONITOR) \
+    || defined(CONFIG_SCHED_IRQMONITOR_GETTIME)
 static inline void timespec_from_usec(FAR struct timespec *ts,
                                       uint64_t microseconds)
 {
@@ -104,6 +100,13 @@ static inline void timespec_from_usec(FAR struct timespec *ts,
   microseconds -= (uint64_t)ts->tv_sec * USEC_PER_SEC;
   ts->tv_nsec   = microseconds * NSEC_PER_USEC;
 }
+#endif
+
+#ifdef CONFIG_SCHED_TICKLESS
+static inline uint64_t timespec_to_usec(const FAR struct timespec *ts)
+{
+  return (uint64_t)ts->tv_sec * USEC_PER_SEC + ts->tv_nsec / NSEC_PER_USEC;
+}
 
 static inline bool timeout_diff(uint32_t new, uint32_t old)
 {
@@ -143,12 +146,13 @@ static uint64_t current_usec(void)
 {
   struct timer_status_s status;
   uint64_t timebase;
-  irqstate_t flags;
 
-  flags = enter_critical_section();
-  TIMER_GETSTATUS(g_timer.lower, &status);
-  timebase = g_timer.timebase;
-  leave_critical_section(flags);
+  do
+    {
+      timebase = g_timer.timebase;
+      TIMER_GETSTATUS(g_timer.lower, &status);
+    }
+  while (timebase != g_timer.timebase);
 
   return timebase + (status.timeout - status.timeleft);
 }
@@ -425,6 +429,44 @@ int up_timer_start(FAR const struct timespec *ts)
 }
 #endif
 
+/********************************************************************************
+ * Name: up_critmon_*
+ *
+ * Description:
+ *   The first interface simply provides the current time value in unknown
+ *   units.  NOTE:  This function may be called early before the timer has
+ *   been initialized.  In that event, the function should just return a
+ *   start time of zero.
+ *
+ *   Nothing is assumed about the units of this time value.  The following
+ *   are assumed, however: (1) The time is an unsigned integer value, (2)
+ *   the time is monotonically increasing, and (3) the elapsed time (also
+ *   in unknown units) can be obtained by subtracting a start time from
+ *   the current time.
+ *
+ *   The second interface simple converts an elapsed time into well known
+ *   units.
+ ********************************************************************************/
+
+#ifdef CONFIG_SCHED_CRITMONITOR
+uint32_t up_critmon_gettime(void)
+{
+  uint32_t ret = 0;
+
+  if (g_timer.lower != NULL)
+    {
+      ret = current_usec();
+    }
+
+  return ret;
+}
+
+void up_critmon_convert(uint32_t elapsed, FAR struct timespec *ts)
+{
+  timespec_from_usec(ts, elapsed);
+}
+#endif
+
 /****************************************************************************
  * Name: up_mdelay
  *