Critical Section Monitor (sched/ and fs/procfs: Remove SCHED_IRQMONITOR_GETTIME to simplify the clock source selection: (1) Use up_critmon_gettime if SCHED_IRQMONITOR, (2) Call clock_systimespec if SCHED_TICKLESS, (3) Don't collect timing info for all other cases and move up_critmon_* to arch.h avoid the duplicated declaration.

include/nuttx/arch.h

@@ -2400,6 +2400,30 @@ void arch_sporadic_suspend(FAR struct tcb_s *tcb);
 void arch_sporadic_resume(FAR struct tcb_s *tcb);
 #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);
+void up_critmon_convert(uint32_t elapsed, FAR struct timespec *ts);
+#endif
+
 #undef EXTERN
 #if defined(__cplusplus)
 }