Default the definition of portASSERT_IF_IN_ISR() to nothing if it is not defined.

Helper updates to allow a count of the number of mutexes held to be added.
Updates to the CCS Cortex-R4 implementation necessitated by a change in compiler semantics.
Update PIC32MX and MZ ports to assert if a non ISR safe function is called from an ISR.

FreeRTOS/Source/include/FreeRTOS.h

@@ -717,6 +717,10 @@ is included as it is used by the port layer. */
 	#define mtCOVERAGE_TEST_MARKER()
 #endif
 
+#ifndef portASSERT_IF_IN_ISR
+	#define portASSERT_IF_IN_ISR()
+#endif
+
 /* Definitions to allow backward compatibility with FreeRTOS versions prior to
 V8 if desired. */
 #ifndef configENABLE_BACKWARD_COMPATIBILITY

FreeRTOS/Source/include/task.h

@@ -1507,7 +1507,7 @@ void vTaskPriorityInherit( TaskHandle_t const pxMutexHolder ) PRIVILEGED_FUNCTIO
  * Set the priority of a task back to its proper priority in the case that it
  * inherited a higher priority while it was holding a semaphore.
  */
-void vTaskPriorityDisinherit( TaskHandle_t const pxMutexHolder ) PRIVILEGED_FUNCTION;
+BaseType_t xTaskPriorityDisinherit( TaskHandle_t const pxMutexHolder ) PRIVILEGED_FUNCTION;
 
 /*
  * Generic version of the task creation function which is in turn called by the
@@ -1552,6 +1552,15 @@ void vTaskStepTick( const TickType_t xTicksToJump ) PRIVILEGED_FUNCTION;
  */
 eSleepModeStatus eTaskConfirmSleepModeStatus( void ) PRIVILEGED_FUNCTION;
 
+/*
+ * For internal use only.  Increment the mutex held count when a mutex is
+ * taken and decrement the mutex held count when the mutex is given back
+ * respectively.  The mutex held count is used to know when it is safe to
+ * disinherit a priority.
+ */
+void vTaskIncrementMutexHeldCount( void );
+void vTaskDecrementMutexHeldCount( void );
+
 #ifdef __cplusplus
 }
 #endif

FreeRTOS/Source/portable/CCS/ARM_Cortex-R4/portASM.asm

@@ -101,7 +101,7 @@ portSAVE_CONTEXT .macro
 
 		; If the task is not using a floating point context then skip the
 		; saving of the FPU registers.
-		BEQ		PC+3
+		BEQ		$+16
 		FSTMDBD	LR!, {D0-D15}
 		FMRX    R1,  FPSCR
 		STMFD   LR!, {R1}
@@ -137,7 +137,7 @@ portRESTORE_CONTEXT .macro
 
 		; If the task is not using a floating point context then skip the
 		; VFP register loads.
-		BEQ		PC+3
+		BEQ		$+16
 
 		; Restore the floating point context.
 		LDMFD   LR!, {R0}

FreeRTOS/Source/portable/IAR/ARM_CA9/port.c

@@ -315,6 +315,16 @@ void vPortEnterCritical( void )
 	directly.  Increment ulCriticalNesting to keep a count of how many times
 	portENTER_CRITICAL() has been called. */
 	ulCriticalNesting++;
+	
+	/* This is not the interrupt safe version of the enter critical function so
+	assert() if it is being called from an interrupt context.  Only API 
+	functions that end in "FromISR" can be used in an interrupt.  Only assert if
+	the critical nesting count is 1 to protect against recursive calls if the
+	assert function also uses a critical section. */
+	if( ulCriticalNesting == 1 )
+	{
+		configASSERT( ulPortInterruptNesting == 0 );
+	}
 }
 /*-----------------------------------------------------------*/
 

FreeRTOS/Source/portable/MPLAB/PIC32MX/portmacro.h

@@ -204,8 +204,8 @@ uint32_t ulCause;							\
 	_CP0_SET_CAUSE( ulCause );					\
 }
 
-#define portCURRENT_INTERRUPT_PRIORITY ( ( _CP0_GET_STATUS() & portALL_IPL_BITS ) >> portIPL_SHIFT )
-#define portASSERT_IF_INTERRUPT_PRIORITY_INVALID() configASSERT( portCURRENT_INTERRUPT_PRIORITY <= configMAX_SYSCALL_INTERRUPT_PRIORITY )
+extern volatile UBaseType_t uxInterruptNesting;
+#define portASSERT_IF_IN_ISR() configASSERT( uxInterruptNesting == 0 )
 
 #define portNOP()	__asm volatile ( "nop" )
 

FreeRTOS/Source/portable/MPLAB/PIC32MZ/portmacro.h

@@ -206,8 +206,8 @@ uint32_t ulCause;							\
 	_CP0_SET_CAUSE( ulCause );					\
 }
 
-#define portCURRENT_INTERRUPT_PRIORITY ( ( _CP0_GET_STATUS() & portALL_IPL_BITS ) >> portIPL_SHIFT )
-#define portASSERT_IF_INTERRUPT_PRIORITY_INVALID() configASSERT( portCURRENT_INTERRUPT_PRIORITY <= configMAX_SYSCALL_INTERRUPT_PRIORITY )
+extern volatile UBaseType_t uxInterruptNesting;
+#define portASSERT_IF_IN_ISR() configASSERT( uxInterruptNesting == 0 )
 
 #define portNOP()	__asm volatile ( "nop" )
 

FreeRTOS/Source/queue.c

@@ -216,7 +216,7 @@ static BaseType_t prvIsQueueFull( const Queue_t *pxQueue ) PRIVILEGED_FUNCTION;
  * Copies an item into the queue, either at the front of the queue or the
  * back of the queue.
  */
-static void prvCopyDataToQueue( Queue_t * const pxQueue, const void *pvItemToQueue, const BaseType_t xPosition ) PRIVILEGED_FUNCTION;
+static BaseType_t prvCopyDataToQueue( Queue_t * const pxQueue, const void *pvItemToQueue, const BaseType_t xPosition ) PRIVILEGED_FUNCTION;
 
 /*
  * Copies an item out of a queue.
@@ -421,7 +421,10 @@ QueueHandle_t xReturn = NULL;
 
 			traceCREATE_MUTEX( pxNewQueue );
 
-			/* Start with the semaphore in the expected state. */
+			/* Start with the semaphore in the expected state.  Preload the
+			 mutex held count as calling xQueueGenericSend() will decrement the
+			 count back to 0. */
+			vTaskIncrementMutexHeldCount();
 			( void ) xQueueGenericSend( pxNewQueue, NULL, ( TickType_t ) 0U, queueSEND_TO_BACK );
 		}
 		else
@@ -508,7 +511,8 @@ QueueHandle_t xReturn = NULL;
 		}
 		else
 		{
-			/* We cannot give the mutex because we are not the holder. */
+			/* The mutex cannot be given because the calling task is not the 
+			holder. */
 			xReturn = pdFAIL;
 
 			traceGIVE_MUTEX_RECURSIVE_FAILED( pxMutex );
@@ -543,8 +547,9 @@ QueueHandle_t xReturn = NULL;
 		{
 			xReturn = xQueueGenericReceive( pxMutex, NULL, xTicksToWait, pdFALSE );
 
-			/* pdPASS will only be returned if we successfully obtained the mutex,
-			we may have blocked to reach here. */
+			/* pdPASS will only be returned if the mutex was successfully 
+			obtained.  The calling task may have entered the Blocked state
+			before reaching here. */
 			if( xReturn == pdPASS )
 			{
 				( pxMutex->u.uxRecursiveCallCount )++;
@@ -592,7 +597,7 @@ QueueHandle_t xReturn = NULL;
 
 BaseType_t xQueueGenericSend( QueueHandle_t xQueue, const void * const pvItemToQueue, TickType_t xTicksToWait, const BaseType_t xCopyPosition )
 {
-BaseType_t xEntryTimeSet = pdFALSE;
+BaseType_t xEntryTimeSet = pdFALSE, xYieldRequired;
 TimeOut_t xTimeOut;
 Queue_t * const pxQueue = ( Queue_t * ) xQueue;
 
@@ -620,7 +625,7 @@ Queue_t * const pxQueue = ( Queue_t * ) xQueue;
 			if( ( pxQueue->uxMessagesWaiting < pxQueue->uxLength ) || ( xCopyPosition == queueOVERWRITE ) )
 			{
 				traceQUEUE_SEND( pxQueue );
-				prvCopyDataToQueue( pxQueue, pvItemToQueue, xCopyPosition );
+				xYieldRequired = prvCopyDataToQueue( pxQueue, pvItemToQueue, xCopyPosition );
 
 				#if ( configUSE_QUEUE_SETS == 1 )
 				{
@@ -657,6 +662,14 @@ Queue_t * const pxQueue = ( Queue_t * ) xQueue;
 								mtCOVERAGE_TEST_MARKER();
 							}
 						}
+						else if( xYieldRequired != pdFALSE )
+						{
+							/* This path is a special case that will only get
+							executed if the task was holding multiple mutexes
+							and the mutexes were given back in an order that is
+							different to that in which they were taken. */
+							queueYIELD_IF_USING_PREEMPTION();
+						}
 						else
 						{
 							mtCOVERAGE_TEST_MARKER();
@@ -690,9 +703,6 @@ Queue_t * const pxQueue = ( Queue_t * ) xQueue;
 				#endif /* configUSE_QUEUE_SETS */
 
 				taskEXIT_CRITICAL();
-
-				/* Return to the original privilege level before exiting the
-				function. */
 				return pdPASS;
 			}
 			else
@@ -1059,7 +1069,20 @@ Queue_t * const pxQueue = ( Queue_t * ) xQueue;
 		{
 			traceQUEUE_SEND_FROM_ISR( pxQueue );
 
-			prvCopyDataToQueue( pxQueue, pvItemToQueue, xCopyPosition );
+			if( prvCopyDataToQueue( pxQueue, pvItemToQueue, xCopyPosition ) != pdFALSE )
+			{
+				/* This is a special case that can only be executed if a task
+				holds multiple mutexes and then gives the mutexes back in an
+				order that is different to that in which they were taken. */
+				if( pxHigherPriorityTaskWoken != NULL )
+				{
+					*pxHigherPriorityTaskWoken = pdTRUE;
+				}
+				else
+				{
+					mtCOVERAGE_TEST_MARKER();
+				}
+			}
 
 			/* The event list is not altered if the queue is locked.  This will
 			be done when the queue is unlocked later. */
@@ -1591,8 +1614,10 @@ Queue_t * const pxQueue = ( Queue_t * ) xQueue;
 #endif /* configUSE_TRACE_FACILITY */
 /*-----------------------------------------------------------*/
 
-static void prvCopyDataToQueue( Queue_t * const pxQueue, const void *pvItemToQueue, const BaseType_t xPosition )
+static BaseType_t prvCopyDataToQueue( Queue_t * const pxQueue, const void *pvItemToQueue, const BaseType_t xPosition )
 {
+BaseType_t xReturn = pdFALSE;
+
 	if( pxQueue->uxItemSize == ( UBaseType_t ) 0 )
 	{
 		#if ( configUSE_MUTEXES == 1 )
@@ -1600,7 +1625,8 @@ static void prvCopyDataToQueue( Queue_t * const pxQueue, const void *pvItemToQue
 			if( pxQueue->uxQueueType == queueQUEUE_IS_MUTEX )
 			{
 				/* The mutex is no longer being held. */
-				vTaskPriorityDisinherit( ( void * ) pxQueue->pxMutexHolder );
+				vTaskDecrementMutexHeldCount();
+				xReturn = xTaskPriorityDisinherit( ( void * ) pxQueue->pxMutexHolder );
 				pxQueue->pxMutexHolder = NULL;				
 			}
 			else
@@ -1658,6 +1684,8 @@ static void prvCopyDataToQueue( Queue_t * const pxQueue, const void *pvItemToQue
 	}
 
 	++( pxQueue->uxMessagesWaiting );
+
+	return xReturn;
 }
 /*-----------------------------------------------------------*/
 
@@ -1678,7 +1706,8 @@ static void prvCopyDataFromQueue( Queue_t * const pxQueue, void * const pvBuffer
 	}
 	else
 	{
-		mtCOVERAGE_TEST_MARKER();
+		/* A mutex was taken. */
+		vTaskIncrementMutexHeldCount();
 	}
 }
 /*-----------------------------------------------------------*/
@@ -2367,8 +2396,9 @@ BaseType_t xReturn;
 		if( pxQueueSetContainer->uxMessagesWaiting < pxQueueSetContainer->uxLength )
 		{
 			traceQUEUE_SEND( pxQueueSetContainer );
-			/* The data copies is the handle of the queue that contains data. */
-			prvCopyDataToQueue( pxQueueSetContainer, &pxQueue, xCopyPosition );
+			/* The data copied is the handle of the queue that contains data. */
+			xReturn = prvCopyDataToQueue( pxQueueSetContainer, &pxQueue, xCopyPosition );
+
 			if( listLIST_IS_EMPTY( &( pxQueueSetContainer->xTasksWaitingToReceive ) ) == pdFALSE )
 			{
 				if( xTaskRemoveFromEventList( &( pxQueueSetContainer->xTasksWaitingToReceive ) ) != pdFALSE )