sched/wdog: Inline wd_start() to improve performance

Move wd_start() to an inline function to reduce function call
    overhead and improve performance in time-critical watchdog operations.

Signed-off-by: Chengdong Wang <wangchengdong@lixiang.com>

include/nuttx/wdog.h

@@ -104,45 +104,6 @@ extern "C"
 #define EXTERN extern
 #endif
 
-/****************************************************************************
- * Name: wd_start
- *
- * Description:
- *   This function adds a watchdog timer to the active timer queue.  The
- *   specified watchdog function at 'wdentry' will be called from the
- *   interrupt level after the specified number of ticks has elapsed.
- *   Watchdog timers may be started from the interrupt level.
- *
- *   Watchdog timers execute in the address environment that was in effect
- *   when wd_start() is called.
- *
- *   Watchdog timers execute only once.
- *
- *   To replace either the timeout delay or the function to be executed,
- *   call wd_start again with the same wdog; only the most recent wdStart()
- *   on a given watchdog ID has any effect.
- *
- * Input Parameters:
- *   wdog     - Watchdog ID
- *   delay    - Delay count in clock ticks
- *   wdentry  - Function to call on timeout
- *   arg      - Parameter to pass to wdentry.
- *
- *   NOTE:  The parameter must be of type wdparm_t.
- *
- * Returned Value:
- *   Zero (OK) is returned on success; a negated errno value is return to
- *   indicate the nature of any failure.
- *
- * Assumptions:
- *   The watchdog routine runs in the context of the timer interrupt handler
- *   and is subject to all ISR restrictions.
- *
- ****************************************************************************/
-
-int wd_start(FAR struct wdog_s *wdog, clock_t delay,
-             wdentry_t wdentry, wdparm_t arg);
-
 /****************************************************************************
  * Name: wd_start_abstick
  *
@@ -182,6 +143,56 @@ int wd_start(FAR struct wdog_s *wdog, clock_t delay,
 int wd_start_abstick(FAR struct wdog_s *wdog, clock_t ticks,
                      wdentry_t wdentry, wdparm_t arg);
 
+/****************************************************************************
+ * Name: wd_start
+ *
+ * Description:
+ *   This function adds a watchdog timer to the active timer queue.  The
+ *   specified watchdog function at 'wdentry' will be called from the
+ *   interrupt level after the specified number of ticks has elapsed.
+ *   Watchdog timers may be started from the interrupt level.
+ *
+ *   Watchdog timers execute in the address environment that was in effect
+ *   when wd_start() is called.
+ *
+ *   Watchdog timers execute only once.
+ *
+ *   To replace either the timeout delay or the function to be executed,
+ *   call wd_start again with the same wdog; only the most recent wdStart()
+ *   on a given watchdog ID has any effect.
+ *
+ * Input Parameters:
+ *   wdog     - Watchdog ID
+ *   delay    - Delay count in clock ticks
+ *   wdentry  - Function to call on timeout
+ *   arg      - Parameter to pass to wdentry
+ *
+ *   NOTE:  The parameter must be of type wdparm_t.
+ *
+ * Returned Value:
+ *   Zero (OK) is returned on success; a negated errno value is return to
+ *   indicate the nature of any failure.
+ *
+ * Assumptions:
+ *   The watchdog routine runs in the context of the timer interrupt handler
+ *   and is subject to all ISR restrictions.
+ *
+ ****************************************************************************/
+
+static inline_function
+int wd_start(FAR struct wdog_s *wdog, clock_t delay,
+             wdentry_t wdentry, wdparm_t arg)
+{
+  /* Ensure delay is within the range the wdog can handle. */
+
+  if (delay >= WDOG_MAX_DELAY)
+    {
+      return -EINVAL;
+    }
+
+  return wd_start_abstick(wdog, clock_delay2abstick(delay), wdentry, arg);
+}
+
 /****************************************************************************
  * Name: wd_start_abstime
  *

sched/wdog/wd_start.c

@@ -345,55 +345,6 @@ int wd_start_abstick(FAR struct wdog_s *wdog, clock_t ticks,
   return OK;
 }
 
-/****************************************************************************
- * Name: wd_start
- *
- * Description:
- *   This function adds a watchdog timer to the active timer queue.  The
- *   specified watchdog function at 'wdentry' will be called from the
- *   interrupt level after the specified number of ticks has elapsed.
- *   Watchdog timers may be started from the interrupt level.
- *
- *   Watchdog timers execute in the address environment that was in effect
- *   when wd_start() is called.
- *
- *   Watchdog timers execute only once.
- *
- *   To replace either the timeout delay or the function to be executed,
- *   call wd_start again with the same wdog; only the most recent wdStart()
- *   on a given watchdog ID has any effect.
- *
- * Input Parameters:
- *   wdog     - Watchdog ID
- *   delay    - Delay count in clock ticks
- *   wdentry  - Function to call on timeout
- *   arg      - Parameter to pass to wdentry
- *
- *   NOTE:  The parameter must be of type wdparm_t.
- *
- * Returned Value:
- *   Zero (OK) is returned on success; a negated errno value is return to
- *   indicate the nature of any failure.
- *
- * Assumptions:
- *   The watchdog routine runs in the context of the timer interrupt handler
- *   and is subject to all ISR restrictions.
- *
- ****************************************************************************/
-
-int wd_start(FAR struct wdog_s *wdog, clock_t delay,
-             wdentry_t wdentry, wdparm_t arg)
-{
-  /* Ensure delay is within the range the wdog can handle. */
-
-  if (delay >= WDOG_MAX_DELAY)
-    {
-      return -EINVAL;
-    }
-
-  return wd_start_abstick(wdog, clock_delay2abstick(delay), wdentry, arg);
-}
-
 /****************************************************************************
  * Name: wd_timer
  *