score: Fix simple timecounter support

Close #2502.

4 files changed, 67 insertions, 17 deletions

diff --git a/cpukit/rtems/src/clocktick.c b/cpukit/rtems/src/clocktick.c
index e2cd35f5fc..a6bf26d1a4 100644
--- a/cpukit/rtems/src/clocktick.c
+++ b/cpukit/rtems/src/clocktick.c
@@ -23,9 +23,13 @@
 
 rtems_status_code rtems_clock_tick( void )
 {
+  ISR_lock_Context lock_context;
+
+  _Timecounter_Acquire( &lock_context );
   _Timecounter_Tick_simple(
     rtems_configuration_get_microseconds_per_tick(),
-    0
+    0,
+    &lock_context
   );
 
   return RTEMS_SUCCESSFUL;
diff --git a/cpukit/sapi/include/rtems/timecounter.h b/cpukit/sapi/include/rtems/timecounter.h
index 04bc534d55..db0a7eee72 100644
--- a/cpukit/sapi/include/rtems/timecounter.h
+++ b/cpukit/sapi/include/rtems/timecounter.h
@@ -94,6 +94,13 @@ typedef struct {
 } rtems_timecounter_simple;
 
 /**
+ * @brief At tick handling done under protection of the timecounter lock.
+ */
+typedef void rtems_timecounter_simple_at_tick(
+  rtems_timecounter_simple *tc
+);
+
+/**
  * @brief Returns the current value of a simple timecounter.
  */
 typedef uint32_t rtems_timecounter_simple_get(
@@ -199,20 +206,28 @@ RTEMS_INLINE_ROUTINE uint32_t rtems_timecounter_simple_scale(
  *
  * @param[in] tc The simple timecounter.
  * @param[in] get The method to get the value of the simple timecounter.
+ * @param[in] at_tick The method to perform work under timecounter lock
+ * protection at this tick, e.g. clear a pending flag.
  */
 RTEMS_INLINE_ROUTINE void rtems_timecounter_simple_downcounter_tick(
-  rtems_timecounter_simple     *tc,
-  rtems_timecounter_simple_get  get
+  rtems_timecounter_simple         *tc,
+  rtems_timecounter_simple_get      get,
+  rtems_timecounter_simple_at_tick  at_tick
 )
 {
+  ISR_lock_Context lock_context;
   uint32_t current;
 
+  _Timecounter_Acquire( &lock_context );
+
+  ( *at_tick )( tc );
+
   current = rtems_timecounter_simple_scale(
     tc,
     tc->real_interval - ( *get )( tc )
   );
 
-  _Timecounter_Tick_simple( tc->binary_interval, current );
+  _Timecounter_Tick_simple( tc->binary_interval, current, &lock_context );
 }
 
 /**
@@ -220,17 +235,25 @@ RTEMS_INLINE_ROUTINE void rtems_timecounter_simple_downcounter_tick(
  *
  * @param[in] tc The simple timecounter.
  * @param[in] get The method to get the value of the simple timecounter.
+ * @param[in] at_tick The method to perform work under timecounter lock
+ * protection at this tick, e.g. clear a pending flag.
  */
 RTEMS_INLINE_ROUTINE void rtems_timecounter_simple_upcounter_tick(
-  rtems_timecounter_simple     *tc,
-  rtems_timecounter_simple_get  get
+  rtems_timecounter_simple         *tc,
+  rtems_timecounter_simple_get      get,
+  rtems_timecounter_simple_at_tick  at_tick
 )
 {
+  ISR_lock_Context lock_context;
   uint32_t current;
 
+  _Timecounter_Acquire( &lock_context );
+
+  ( *at_tick )( tc );
+
   current = rtems_timecounter_simple_scale( tc, ( *get )( tc ) );
 
-  _Timecounter_Tick_simple( tc->binary_interval, current );
+  _Timecounter_Tick_simple( tc->binary_interval, current, &lock_context );
 }
 
 /**
diff --git a/cpukit/score/include/rtems/score/timecounter.h b/cpukit/score/include/rtems/score/timecounter.h
index 0d17cc7ce3..33de269ec8 100644
--- a/cpukit/score/include/rtems/score/timecounter.h
+++ b/cpukit/score/include/rtems/score/timecounter.h
@@ -26,6 +26,8 @@
 #include <sys/time.h>
 #include <sys/timetc.h>
 
+#include <rtems/score/isrlock.h>
+
 #ifdef __cplusplus
 extern "C" {
 #endif /* __cplusplus */
@@ -161,6 +163,21 @@ void _Timecounter_Install( struct timecounter *tc );
 void _Timecounter_Tick( void );
 
 /**
+ * @brief Lock to protect the timecounter mechanic.
+ */
+ISR_LOCK_DECLARE( extern, _Timecounter_Lock )
+
+/**
+ * @brief Acquires the timecounter lock.
+ *
+ * @param[in] lock_context The lock context.
+ *
+ * See _Timecounter_Tick_simple().
+ */
+#define _Timecounter_Acquire( lock_context ) \
+  _ISR_lock_ISR_disable_and_acquire( &_Timecounter_Lock, lock_context )
+
+/**
  * @brief Performs a simple timecounter tick.
  *
  * This is a special purpose tick function for simple timecounter to support
@@ -169,8 +186,14 @@ void _Timecounter_Tick( void );
  * @param[in] delta The time in timecounter ticks elapsed since the last call
  * to _Timecounter_Tick_simple().
  * @param[in] offset The current value of the timecounter.
- */
-void _Timecounter_Tick_simple( uint32_t delta, uint32_t offset );
+ * @param[in] lock_context The lock context of the corresponding
+ * _Timecounter_Acquire().
+ */
+void _Timecounter_Tick_simple(
+  uint32_t delta,
+  uint32_t offset,
+  ISR_lock_Context *lock_context
+);
 
 /**
  * @brief The wall clock time in seconds.
diff --git a/cpukit/score/src/kern_tc.c b/cpukit/score/src/kern_tc.c
index f6a1136d31..4257533455 100644
--- a/cpukit/score/src/kern_tc.c
+++ b/cpukit/score/src/kern_tc.c
@@ -64,7 +64,9 @@ __FBSDID("$FreeBSD r284178 2015-06-09T11:49:56Z$");
 #ifdef __rtems__
 #include <limits.h>
 #include <rtems.h>
-ISR_LOCK_DEFINE(static, _Timecounter_Lock, "Timecounter");
+ISR_LOCK_DEFINE(, _Timecounter_Lock, "Timecounter")
+#define _Timecounter_Release(lock_context) \
+  _ISR_lock_Release_and_ISR_enable(&_Timecounter_Lock, lock_context)
 #define hz rtems_clock_get_ticks_per_second()
 #define printf(...)
 #define log(...)
@@ -1383,7 +1385,7 @@ tc_windup(void)
 #ifdef __rtems__
 	ISR_lock_Context lock_context;
 
-	_ISR_lock_ISR_disable_and_acquire(&_Timecounter_Lock, &lock_context);
+	_Timecounter_Acquire(&lock_context);
 #endif /* __rtems__ */
 
 	/*
@@ -1538,7 +1540,7 @@ tc_windup(void)
 	timekeep_push_vdso();
 #endif /* __rtems__ */
 #ifdef __rtems__
-	_ISR_lock_Release_and_ISR_enable(&_Timecounter_Lock, &lock_context);
+	_Timecounter_Release(&lock_context);
 #endif /* __rtems__ */
 }
 
@@ -1963,14 +1965,12 @@ _Timecounter_Tick(void)
 }
 #ifdef __rtems__
 void
-_Timecounter_Tick_simple(uint32_t delta, uint32_t offset)
+_Timecounter_Tick_simple(uint32_t delta, uint32_t offset,
+    ISR_lock_Context *lock_context)
 {
 	struct bintime bt;
 	struct timehands *th;
 	uint32_t ogen;
-	ISR_lock_Context lock_context;
-
-	_ISR_lock_ISR_disable_and_acquire(&_Timecounter_Lock, &lock_context);
 
 	th = timehands;
 	ogen = th->th_generation;
@@ -1997,7 +1997,7 @@ _Timecounter_Tick_simple(uint32_t delta, uint32_t offset)
 	time_second = th->th_microtime.tv_sec;
 	time_uptime = th->th_offset.sec;
 
-	_ISR_lock_Release_and_ISR_enable(&_Timecounter_Lock, &lock_context);
+	_Timecounter_Release(lock_context);
 
 	_Watchdog_Tick();
 }