Added a critical section around the call to vTaskIncrementTick() in all the RX ports.

Source/portable/GCC/RX600/port.c

@@ -72,6 +72,14 @@ PSW is set with U and I set, and PM and IPL clear. */
 #define portINITIAL_PSW     ( ( portSTACK_TYPE ) 0x00030000 )
 #define portINITIAL_FPSW    ( ( portSTACK_TYPE ) 0x00000100 )
 
+/* These macros allow a critical section to be added around the call to
+vTaskIncrementTick(), which is only ever called from interrupts at the kernel 
+priority - ie a known priority.  Therefore these local macros are a slight 
+optimisation compared to calling the global SET/CLEAR_INTERRUPT_MASK macros, 
+which would require the old IPL to be read first and stored in a local variable. */
+#define portDISABLE_INTERRUPTS_FROM_KERNEL_ISR() 	__asm volatile ( "MVTIPL	%0" ::"i"(configMAX_SYSCALL_INTERRUPT_PRIORITY) )
+#define portENABLE_INTERRUPTS_FROM_KERNEL_ISR() 	__asm volatile ( "MVTIPL	%0" ::"i"(configKERNEL_INTERRUPT_PRIORITY) )
+
 /*-----------------------------------------------------------*/
 
 /*
@@ -201,8 +209,12 @@ void vTickISR( void )
 	__asm volatile( "SETPSW		I" );
 	
 	/* Increment the tick, and perform any processing the new tick value
-	necessitates. */
-	vTaskIncrementTick(); 
+	necessitates.  Ensure IPL is at the max syscall value first. */
+	portDISABLE_INTERRUPTS_FROM_KERNEL_ISR();
+	{
+		vTaskIncrementTick(); 
+	}
+	portENABLE_INTERRUPTS_FROM_KERNEL_ISR();
 	
 	/* Only select a new task if the preemptive scheduler is being used. */
 	#if( configUSE_PREEMPTION == 1 )

Source/portable/IAR/RX600/port.c

@@ -196,7 +196,11 @@ __interrupt void vTickISR( void )
 	
 	/* Increment the tick, and perform any processing the new tick value
 	necessitates. */
-	vTaskIncrementTick();
+	__set_interrupt_level( configMAX_SYSCALL_INTERRUPT_PRIORITY );
+	{
+		vTaskIncrementTick();
+	}
+	__set_interrupt_level( configKERNEL_INTERRUPT_PRIORITY );
 	
 	/* Only select a new task if the preemptive scheduler is being used. */
 	#if( configUSE_PREEMPTION == 1 )

Source/portable/Renesas/RX600/port.c

@@ -237,7 +237,11 @@ void vTickISR( void )
 {
 	/* Increment the tick, and perform any processing the new tick value
 	necessitates. */
-	vTaskIncrementTick();
+	set_ipl( configMAX_SYSCALL_INTERRUPT_PRIORITY );
+	{
+		vTaskIncrementTick();
+	}
+	set_ipl( configKERNEL_INTERRUPT_PRIORITY );
 	
 	/* Only select a new task if the preemptive scheduler is being used. */
 	#if( configUSE_PREEMPTION == 1 )