Update kernel to support SMP

The XMOS XCore ports are also updated to support SMP.

event_groups.c

@@ -256,7 +256,7 @@ EventBits_t xEventGroupSync( EventGroupHandle_t xEventGroup,
     {
         if( xAlreadyYielded == pdFALSE )
         {
-            portYIELD_WITHIN_API();
+            vTaskYieldWithinAPI();
         }
         else
         {
@@ -408,7 +408,7 @@ EventBits_t xEventGroupWaitBits( EventGroupHandle_t xEventGroup,
     {
         if( xAlreadyYielded == pdFALSE )
         {
-            portYIELD_WITHIN_API();
+            vTaskYieldWithinAPI();
         }
         else
         {

include/FreeRTOS.h

@@ -236,6 +236,14 @@
     #define configUSE_COUNTING_SEMAPHORES    0
 #endif
 
+#ifndef configUSE_TASK_PREEMPTION_DISABLE
+    #define configUSE_TASK_PREEMPTION_DISABLE    0
+#endif
+
+#ifndef configUSE_CORE_EXCLUSION
+    #define configUSE_CORE_EXCLUSION    0
+#endif
+
 #ifndef configUSE_ALTERNATIVE_API
     #define configUSE_ALTERNATIVE_API    0
 #endif
@@ -283,6 +291,15 @@
     #define portSOFTWARE_BARRIER()
 #endif
 
+#ifndef configNUM_CORES
+    #define configNUM_CORES    1
+#endif
+
+#ifndef configRUN_MULTIPLE_PRIORITIES
+    #define configRUN_MULTIPLE_PRIORITIES    0
+#endif
+
+
 /* The timers module relies on xTaskGetSchedulerState(). */
 #if configUSE_TIMERS == 1
 
@@ -782,10 +799,6 @@
     #define portPRIVILEGE_BIT    ( ( UBaseType_t ) 0x00 )
 #endif
 
-#ifndef portYIELD_WITHIN_API
-    #define portYIELD_WITHIN_API    portYIELD
-#endif
-
 #ifndef portSUPPRESS_TICKS_AND_SLEEP
     #define portSUPPRESS_TICKS_AND_SLEEP( xExpectedIdleTime )
 #endif
@@ -930,6 +943,18 @@
     #error configUSE_MUTEXES must be set to 1 to use recursive mutexes
 #endif
 
+#if( ( configRUN_MULTIPLE_PRIORITIES == 0 ) && ( configUSE_CORE_EXCLUSION != 0 ) )
+    #error configRUN_MULTIPLE_PRIORITIES must be set to 1 to use core exclusion
+#endif
+
+#if( ( configRUN_MULTIPLE_PRIORITIES == 0 ) && ( configUSE_TASK_PREEMPTION_DISABLE != 0 ) )
+    #error configRUN_MULTIPLE_PRIORITIES must be set to 1 to use task preemption disable
+#endif
+
+#if( ( configUSE_PREEMPTION == 0 ) && ( configUSE_TASK_PREEMPTION_DISABLE != 0 ) )
+    #error configUSE_PREEMPTION must be set to 1 to use task preemption disable
+#endif
+
 #ifndef configINITIAL_TICK_COUNT
     #define configINITIAL_TICK_COUNT    0
 #endif
@@ -1174,7 +1199,14 @@ typedef struct xSTATIC_TCB
     StaticListItem_t xDummy3[ 2 ];
     UBaseType_t uxDummy5;
     void * pxDummy6;
+    BaseType_t xDummy23[ 2 ];
     uint8_t ucDummy7[ configMAX_TASK_NAME_LEN ];
+    #if ( configUSE_TASK_PREEMPTION_DISABLE == 1 )
+        BaseType_t xDummy24;
+    #endif
+    #if ( configUSE_CORE_EXCLUSION == 1 )
+        UBaseType_t uxDummy25;
+    #endif
     #if ( ( portSTACK_GROWTH > 0 ) || ( configRECORD_STACK_HIGH_ADDRESS == 1 ) )
         void * pxDummy8;
     #endif

include/task.h

@@ -214,6 +214,9 @@ typedef enum
  * task. h
  *
  * Macro to disable all maskable interrupts.
+ * This also returns what the interrupt state was
+ * upon being called. This state may subsequently
+ * be passed to taskRESTORE_INTERRUPTS().
  *
  * \defgroup taskDISABLE_INTERRUPTS taskDISABLE_INTERRUPTS
  * \ingroup SchedulerControl
@@ -230,6 +233,28 @@ typedef enum
  */
 #define taskENABLE_INTERRUPTS()            portENABLE_INTERRUPTS()
 
+/**
+ * task. h
+ *
+ * Macro to restore microcontroller interrupts to
+ * a previous state.
+ *
+ * \defgroup taskRESTORE_INTERRUPTS taskRESTORE_INTERRUPTS
+ * \ingroup SchedulerControl
+ */
+#define taskRESTORE_INTERRUPTS(ulState) portRESTORE_INTERRUPTS(ulState)
+
+/**
+ * task. h
+ *
+ * Macro that determines if it is being called from within an ISR
+ * or a task. Returns non-zero if it is in an ISR.
+ *
+ * \defgroup taskCHECK_IF_IN_ISR taskCHECK_IF_IN_ISR
+ * \ingroup SchedulerControl
+ */
+#define taskCHECK_IF_IN_ISR() portCHECK_IF_IN_ISR()
+
 /* Definitions returned by xTaskGetSchedulerState().  taskSCHEDULER_SUSPENDED is
  * 0 to generate more optimal code when configASSERT() is defined as the constant
  * is used in assert() statements. */
@@ -237,6 +262,8 @@ typedef enum
 #define taskSCHEDULER_NOT_STARTED    ( ( BaseType_t ) 1 )
 #define taskSCHEDULER_RUNNING        ( ( BaseType_t ) 2 )
 
+/* Check if core value is valid */
+#define taskVALID_CORE_ID( xCoreID ) ( ( BaseType_t ) ( ( 0 <= xCoreID ) && ( xCoreID < configNUM_CORES ) ) )
 
 /*-----------------------------------------------------------
 * TASK CREATION API
@@ -1208,6 +1235,12 @@ void vTaskResume( TaskHandle_t xTaskToResume ) PRIVILEGED_FUNCTION;
  */
 BaseType_t xTaskResumeFromISR( TaskHandle_t xTaskToResume ) PRIVILEGED_FUNCTION;
 
+void vTaskCoreExclusionSet( const TaskHandle_t xTask, UBaseType_t uxCoreExclude );
+UBaseType_t vTaskCoreExclusionGet( const TaskHandle_t xTask );
+
+void vTaskPreemptionDisable( const TaskHandle_t xTask );
+void vTaskPreemptionEnable( const TaskHandle_t xTask );
+
 /*-----------------------------------------------------------
 * SCHEDULER CONTROL
 *----------------------------------------------------------*/
@@ -1666,10 +1699,10 @@ BaseType_t xTaskCallApplicationTaskHook( TaskHandle_t xTask,
  * xTaskGetIdleTaskHandle() is only available if
  * INCLUDE_xTaskGetIdleTaskHandle is set to 1 in FreeRTOSConfig.h.
  *
- * Simply returns the handle of the idle task.  It is not valid to call
+ * Simply returns a pointer to the array of idle task handles.
- * xTaskGetIdleTaskHandle() before the scheduler has been started.
+ * It is not valid to call xTaskGetIdleTaskHandle() before the scheduler has been started.
  */
-TaskHandle_t xTaskGetIdleTaskHandle( void ) PRIVILEGED_FUNCTION;
+TaskHandle_t *xTaskGetIdleTaskHandle( void ) PRIVILEGED_FUNCTION;
 
 /**
  * configUSE_TRACE_FACILITY must be defined as 1 in FreeRTOSConfig.h for
@@ -2946,7 +2979,7 @@ void vTaskRemoveFromUnorderedEventList( ListItem_t * pxEventListItem,
  * Sets the pointer to the current TCB to the TCB of the highest priority task
  * that is ready to run.
  */
-portDONT_DISCARD void vTaskSwitchContext( void ) PRIVILEGED_FUNCTION;
+portDONT_DISCARD void vTaskSwitchContext( BaseType_t xCoreID ) PRIVILEGED_FUNCTION;
 
 /*
  * THESE FUNCTIONS MUST NOT BE USED FROM APPLICATION CODE.  THEY ARE USED BY
@@ -2959,6 +2992,11 @@ TickType_t uxTaskResetEventItemValue( void ) PRIVILEGED_FUNCTION;
  */
 TaskHandle_t xTaskGetCurrentTaskHandle( void ) PRIVILEGED_FUNCTION;
 
+/*
+ * Return the handle of the task running on specified core.
+ */
+TaskHandle_t xTaskGetCurrentTaskHandleCPU( UBaseType_t xCoreID ) PRIVILEGED_FUNCTION;
+
 /*
  * Shortcut used by the queue implementation to prevent unnecessary call to
  * taskYIELD();
@@ -3044,6 +3082,11 @@ TaskHandle_t pvTaskIncrementMutexHeldCount( void ) PRIVILEGED_FUNCTION;
  */
 void vTaskInternalSetTimeOutState( TimeOut_t * const pxTimeOut ) PRIVILEGED_FUNCTION;
 
+/*
+ * For internal use only. Same as portYIELD_WITHIN_API() in single core FreeRTOS.
+ * For SMP this is not defined by the port.
+ */
+void vTaskYieldWithinAPI( void );
 
 /* *INDENT-OFF* */
 #ifdef __cplusplus

portable/XCC/XCORE200/port.c

@@ -9,14 +9,29 @@
 
 static hwtimer_t xKernelTimer;
 
-uint32_t ulPortYieldRequired = pdFALSE;
+uint32_t ulPortYieldRequired[ portMAX_CORE_COUNT ] = { pdFALSE };
 
 /*-----------------------------------------------------------*/
 
+void vIntercoreInterruptISR( void )
+{
+	int xCoreID;
+
+//	debug_printf( "In KCALL: %u\n", ulData );
+	xCoreID = rtos_core_id_get();
+	ulPortYieldRequired[ xCoreID ] = pdTRUE;
+}
+/*-----------------------------------------------------------*/
+
 DEFINE_RTOS_INTERRUPT_CALLBACK( pxKernelTimerISR, pvData )
 {
 	uint32_t ulLastTrigger;
 	uint32_t ulNow;
+	int xCoreID;
+
+	xCoreID = 0;
+
+	configASSERT( xCoreID == rtos_core_id_get() );
 
 	/* Need the next interrupt to be scheduled relative to
 	 * the current trigger time, rather than the current
@@ -40,14 +55,36 @@ DEFINE_RTOS_INTERRUPT_CALLBACK( pxKernelTimerISR, pvData )
 
 	if( xTaskIncrementTick() != pdFALSE )
 	{
-		ulPortYieldRequired = pdTRUE;
+		ulPortYieldRequired[ xCoreID ] = pdTRUE;
 	}
 }
 /*-----------------------------------------------------------*/
 
-static void prvCoreInit( void )
+void vPortYieldOtherCore( int xOtherCoreID )
 {
-	rtos_core_register();
+	int xCoreID;
+
+	/*
+	 * This function must be called from within a critical section.
+	 */
+
+	xCoreID = rtos_core_id_get();
+
+//	debug_printf("%d->%d\n", xCoreID, xOtherCoreID);
+
+//	debug_printf("Yield core %d from %d\n", xOtherCoreID, xCoreID );
+
+	rtos_irq( xOtherCoreID, xCoreID );
+}
+/*-----------------------------------------------------------*/
+
+static int prvCoreInit( void )
+{
+	int xCoreID;
+
+	xCoreID = rtos_core_register();
+	debug_printf( "Logical Core %d initializing as FreeRTOS Core %d\n", get_logical_core_id(), xCoreID );
+
 	asm volatile (
 			"ldap r11, kexcept\n\t"
 			"set kep, r11\n\t"
@@ -56,35 +93,49 @@ static void prvCoreInit( void )
 			: "r11"
 	);
 
-	rtos_irq_enable( 1 );
+	rtos_irq_enable( configNUM_CORES );
 
-	uint32_t ulNow;
+	/*
-	ulNow = hwtimer_get_time( xKernelTimer );
+	 * All threads wait here until all have enabled IRQs
-//	debug_printf( "The time is now (%u)\n", ulNow );
+	 */
+	while( rtos_irq_ready() == pdFALSE );
 
-	ulNow += configCPU_CLOCK_HZ / configTICK_RATE_HZ;
+	if( xCoreID == 0 )
+	{
+		uint32_t ulNow;
+		ulNow = hwtimer_get_time( xKernelTimer );
+//		debug_printf( "The time is now (%u)\n", ulNow );
 
-	triggerable_setup_interrupt_callback( xKernelTimer, NULL, RTOS_INTERRUPT_CALLBACK( pxKernelTimerISR ) );
+		ulNow += configCPU_CLOCK_HZ / configTICK_RATE_HZ;
-	hwtimer_set_trigger_time( xKernelTimer, ulNow );
+
-	triggerable_enable_trigger( xKernelTimer );
+		triggerable_setup_interrupt_callback( xKernelTimer, NULL, RTOS_INTERRUPT_CALLBACK( pxKernelTimerISR ) );
+		hwtimer_set_trigger_time( xKernelTimer, ulNow );
+		triggerable_enable_trigger( xKernelTimer );
+	}
+
+	return xCoreID;
 }
 /*-----------------------------------------------------------*/
 
 DEFINE_RTOS_KERNEL_ENTRY( void, vPortStartSchedulerOnCore, void )
 {
-	prvCoreInit();
+	int xCoreID;
 
-	debug_printf( "FreeRTOS initialized\n" );
+	xCoreID = prvCoreInit();
+
+	debug_printf( "FreeRTOS Core %d initialized\n", xCoreID );
 
 	/*
 	 * Restore the context of the first thread
 	 * to run and jump into it.
 	 */
 	asm volatile (
+			"mov r6, %0\n\t" /* R6 must be the FreeRTOS core ID*/
+			"ldaw r5, dp[pxCurrentTCBs]\n\t" /* R5 must be the TCB list which is indexed by R6 */
 			"bu _freertos_restore_ctx\n\t"
 			: /* no outputs */
-			: /* no inputs */
+			: "r"(xCoreID)
-			: /* nothing is clobbered */
+			: "r5", "r6"
 	);
 }
 /*-----------------------------------------------------------*/
@@ -159,14 +210,22 @@ StackType_t *pxPortInitialiseStack( StackType_t *pxTopOfStack, TaskFunction_t px
 }
 /*-----------------------------------------------------------*/
 
+void vPortStartSMPScheduler( void );
+
 /*
  * See header file for description.
  */
 BaseType_t xPortStartScheduler( void )
 {
+	if( ( configNUM_CORES > portMAX_CORE_COUNT ) || ( configNUM_CORES <= 0 ) )
+	{
+		return pdFAIL;
+	}
+
 	rtos_locks_initialize();
 	xKernelTimer = hwtimer_alloc();
-	RTOS_KERNEL_ENTRY(vPortStartSchedulerOnCore)();
+
+	vPortStartSMPScheduler();
 
 	return pdPASS;
 }

portable/XCC/XCORE200/port.xc

@@ -0,0 +1,26 @@
+/*
+ * port.xc
+ *
+ *  Created on: Jul 31, 2019
+ *      Author: mbruno
+ */
+
+//#include "rtos_support.h"
+
+extern "C" {
+
+#include "FreeRTOSConfig.h" /* to get configNUM_CORES */
+#ifndef configNUM_CORES
+#define configNUM_CORES 1
+#endif
+
+void __xcore_interrupt_permitted_ugs_vPortStartSchedulerOnCore(void);
+
+} /* extern "C" */
+
+void vPortStartSMPScheduler( void )
+{
+    par (int i = 0; i < configNUM_CORES; i++) {
+        __xcore_interrupt_permitted_ugs_vPortStartSchedulerOnCore();
+    }
+}

portable/XCC/XCORE200/portasm.S

@@ -21,10 +21,13 @@ kexcept:
   bau r11 //_TrapHandler is at 0x00040080. TODO: Is it always? Why can't I access the symbol _TrapHandler?
 
 _yield:
-  set    sp,     r4  /* Restore the task's SP to save the rest of its context. */
+ {set    sp,     r4                  /* Restore the task's SP to save the rest of its context. */
-  bu _yield_continue /* Skip the ulPortYieldRequired check and jump right to */
+  get    r11,    id}                 /* Get the logical core ID into r11. */
-                     /* the context save and switch. Also skips saving SPC */
+  ldaw   r0,     dp[rtos_core_map]
-                     /* since the kcall handler has already saved it. */
+  ldw    r0,     r0[r11]             /* Translate to the RTOS core ID into r0 */
+  bu _yield_continue                 /* Skip the ulPortYieldRequired check and jump right to */
+                                     /* the context save and switch. Also skips saving SPC */
+                                     /* since the kcall handler has already saved it. */
 
 .align 64
 kcall:
@@ -68,7 +71,7 @@ rtos_interrupt_callback_common:
  {stw    r4,     sp[12]
 /*stw    r11,    sp[19]     already saved by the wrapper function. */
 
-  ldaw   r4,     sp[0]}  /* Get value of current stackpointer into r4 */
+  ldaw   r4,     sp[0]}  /* Get value of current stackpointer into r4. */
 
  {kentsp 0               /* switch to the kernel stack. */
                          /* The value 0 is safe to use since we don't need the SP */
@@ -78,12 +81,16 @@ rtos_interrupt_callback_common:
  {mov    r0,     r11     /* into the first argument for the callback function... */
   bla    r1}             /* and call the callback function. */
 
-  set    sp,     r4      /* Restore the task's SP now. */
+ {set    sp,     r4      /* Restore the task's SP now. */
-
+ 
-  ldw    r0,     dp[ulPortYieldRequired]       /* Is a yield required? */
+  get    r11,    id}                           /* Get the logical core ID into r11. */
- {bf     r0,     _freertos_restore_ctx_partial /* If not, restore the context now. */
+  ldaw   r0,     dp[rtos_core_map]
-  ldc    r0,     0}
+  ldw    r0,     r0[r11]                       /* Translate to the RTOS core ID into r0. */
-  stw    r0,     dp[ulPortYieldRequired]       /* Otherwise, clear the yield required flag. */
+  ldaw   r2,     dp[ulPortYieldRequired]       /* Get the yield required array into r2. */
+  ldw    r1,     r2[r0]                        /* Is a yield required for this core? */
+ {bf     r1,     _freertos_restore_ctx_partial /* If not, restore the context now. */
+  ldc    r1,     0}
+  stw    r1,     r2[r0]                        /* Otherwise, clear the yield required flag. */
 
   /* Save the rest of the current task's context. */
   stw    spc,    sp[1]
@@ -100,14 +107,17 @@ _yield_continue:
   stw    r9,     sp[17]
   stw    r10,    sp[18]
 
-  ldw    r0,     dp[pxCurrentTCB] /* Save the current task's SP to the first */
+  ldaw   r5,     dp[pxCurrentTCBs] /* Get the current TCB array into r5. */
-  stw    r4,     r0[0x0]          /* word (top of stack) in the current TCB */
+  ldw    r1,     r5[r0]            /* Get this core's current TCB pointer into r1. */
+  stw    r4,     r1[0x0]           /* Save the current task's SP to the first */
+                                   /* word (top of stack) in the current TCB. */
 
-  kentsp 0                        /* switch back to the kernel stack. */
+ {kentsp 0                         /* switch back to the kernel stack. */
 
+  mov    r6,     r0}               /* copy the RTOS core ID into r6 so we don't lose it. */
   ldap   r11,    vTaskSwitchContext
-  bla    r11             /* Finally call vTaskSwitchContext() now that the task's */
+  bla    r11             /* Finally call vTaskSwitchContext(core_id) now that the task's */
-                         /* entire context is saved. */
+                         /* entire context is saved. Note the core id in r0 is the argument. */
 
 //krestsp 0              /* unnecessary since KSP is already set and the SP */
                          /* is being restored next from the current TCB. */
@@ -115,7 +125,7 @@ _yield_continue:
 .globl _freertos_restore_ctx
 _freertos_restore_ctx:
 
-  ldw    r0,     dp[pxCurrentTCB]
+  ldw    r0,     r5[r6]  /* get this core's current TCB pointer into r0 */
   ldw    r0,     r0[0x0] /* Get the top of the stack from the current TCB... */
   set    sp,     r0;     /* into the stack pointer register. */
 

portable/XCC/XCORE200/portmacro.h

@@ -46,9 +46,9 @@ typedef uint32_t UBaseType_t;
 #define portTICK_PERIOD_MS			  ( ( TickType_t ) 1000 / configTICK_RATE_HZ )
 #define portBYTE_ALIGNMENT			  8
 #define portCRITICAL_NESTING_IN_TCB   1
-#ifdef configNUM_CORES
+#define portMAX_CORE_COUNT            8
-#warning configNUM_CORES should not be defined when using the single core XCORE port
+#ifndef configNUM_CORES
-#undef configNUM_CORES
+#define configNUM_CORES               1
 #endif
 
 /* This may be set to zero in the config file if the rtos_time
@@ -67,6 +67,12 @@ functions are not needed or if it is incremented elsewhere. */
 #define portTHREAD_CONTEXT_STACK_GROWTH RTOS_SUPPORT_INTERRUPT_STACK_GROWTH
 
 #ifndef __ASSEMBLER__
+
+/* Check validity of number of cores specified in config */
+#if ( configNUM_CORES < 1 || portMAX_CORE_COUNT < configNUM_CORES )
+#error "Invalid number of cores specified in config!"
+#endif
+
 #define portMEMORY_BARRIER() RTOS_MEMORY_BARRIER()
 #define portTASK_STACK_DEPTH(pxTaskCode) RTOS_THREAD_STACK_SIZE(pxTaskCode)
 /*-----------------------------------------------------------*/
@@ -79,17 +85,24 @@ do \
 { \
 	if( xSwitchRequired != pdFALSE ) \
 	{ \
-		extern uint32_t ulPortYieldRequired; \
+		extern uint32_t ulPortYieldRequired[ portMAX_CORE_COUNT ]; \
-	    ulPortYieldRequired = pdTRUE; \
+	    ulPortYieldRequired[ portGET_CORE_ID() ] = pdTRUE; \
 	} \
 } while( 0 )
 
 #define portYIELD_FROM_ISR( x ) portEND_SWITCHING_ISR( x )
 /*-----------------------------------------------------------*/
 
+/* SMP utilities. */
+#define portGET_CORE_ID() rtos_core_id_get()
+
+void vPortYieldOtherCore( int xOtherCoreID );
+#define portYIELD_CORE( x ) vPortYieldOtherCore( x )
+/*-----------------------------------------------------------*/
+
 /* Architecture specific optimisations. */
 #ifndef configUSE_PORT_OPTIMISED_TASK_SELECTION
-#define configUSE_PORT_OPTIMISED_TASK_SELECTION 1
+#define configUSE_PORT_OPTIMISED_TASK_SELECTION 0
 #endif
 
 #if configUSE_PORT_OPTIMISED_TASK_SELECTION == 1
@@ -108,10 +121,16 @@ do \
 /* Critical section management. */
 
 #define portGET_INTERRUPT_STATE() rtos_interrupt_mask_get()
+
+/*
+ * This differs from the standard portDISABLE_INTERRUPTS()
+ * in that it also returns what the interrupt state was
+ * before it disabling interrupts.
+ */
 #define portDISABLE_INTERRUPTS() rtos_interrupt_mask_all()
+
 #define portENABLE_INTERRUPTS() rtos_interrupt_unmask_all()
-#define portSET_INTERRUPT_MASK_FROM_ISR() 0
+
-#define portCLEAR_INTERRUPT_MASK_FROM_ISR(x)
 /*
  * Will enable interrupts if ulState is non-zero.
  */
@@ -122,12 +141,43 @@ do \
  * ISR or otherwise in kernel mode.
  */
 #define portCHECK_IF_IN_ISR() rtos_isr_running()
+
 #define portASSERT_IF_IN_ISR() configASSERT( portCHECK_IF_IN_ISR() == 0 )
 
+#define portGET_ISR_LOCK()      rtos_lock_acquire(0)
+#define portRELEASE_ISR_LOCK()  rtos_lock_release(0)
+#define portGET_TASK_LOCK()     rtos_lock_acquire(1)
+#define portRELEASE_TASK_LOCK() rtos_lock_release(1)
+
 void vTaskEnterCritical(void);
 void vTaskExitCritical(void);
-#define portENTER_CRITICAL()					vTaskEnterCritical()
+#define portENTER_CRITICAL()                   vTaskEnterCritical()
-#define portEXIT_CRITICAL()						vTaskExitCritical()
+#define portEXIT_CRITICAL()                    vTaskExitCritical()
+
+/*
+ * vTaskEnterCritical() has been modified to be safe to use
+ * from within ISRs. The previous mask does not need to be
+ * returned since in the xCORE interrupts are always disabled
+ * in ISRs. Effectively this call just grabs the kernel lock
+ * when called from an ISR.
+ */
+static inline uint32_t portSET_INTERRUPT_MASK_FROM_ISR( void )
+{
+	vTaskEnterCritical();
+	return 0;
+}
+#define portSET_INTERRUPT_MASK_FROM_ISR() portSET_INTERRUPT_MASK_FROM_ISR()
+
+/*
+ * vTaskExitCritical() has been modified to be safe to use
+ * from within ISRs. When the nesting level has reached zero
+ * it releases the lock, but when called from within an ISR
+ * it will *not* re-enable interrupts since it is assumed they
+ * were previously disabled. Thus the previous state in x is
+ * unused.
+ */
+#define portCLEAR_INTERRUPT_MASK_FROM_ISR(x)   vTaskExitCritical()
+
 /*-----------------------------------------------------------*/
 
 /* Runtime stats support */

portable/XCC/XCORE200/rtos_support_rtos_config.h

@@ -35,7 +35,10 @@
  * The RTOS provided handler that should run when a
  * core receives an intercore interrupt request.
  */
-#define RTOS_INTERCORE_INTERRUPT_ISR()
+#define RTOS_INTERCORE_INTERRUPT_ISR() do { \
+	void vIntercoreInterruptISR( void ); \
+	vIntercoreInterruptISR(); \
+} while ( 0 )
 
 /**
  * The number of hardware locks that the RTOS
@@ -45,7 +48,7 @@
  * Note that the IRQ routines require a lock and
  * will share the first one with the RTOS.
  */
-#define RTOS_LOCK_COUNT 0
+#define RTOS_LOCK_COUNT 2
 
 /**
  * Remaps all calls to debug_printf() to rtos_printf().
@@ -64,6 +67,15 @@
 		#endif
 		#define DEBUG_PRINT_ENABLE 1
 
+		#ifndef configTASKS_DEBUG
+			#define configTASKS_DEBUG 0
+		#endif
+		#if configTASKS_DEBUG == 1
+			#define DEBUG_PRINT_ENABLE_FREERTOS_TASKS 1
+		#else
+			#define DEBUG_PRINT_DISABLE_FREERTOS_TASKS 1
+		#endif
+
 	#else /* configENABLE_DEBUG_PRINTF */
 
 		/* ensure that debug_printf is disabled */

portable/XCC/XCOREAI/port.c

@@ -10,14 +10,29 @@
 
 static hwtimer_t xKernelTimer;
 
-uint32_t ulPortYieldRequired = pdFALSE;
+uint32_t ulPortYieldRequired[ portMAX_CORE_COUNT ] = { pdFALSE };
 
 /*-----------------------------------------------------------*/
 
+void vIntercoreInterruptISR( void )
+{
+	int xCoreID;
+
+//	debug_printf( "In KCALL: %u\n", ulData );
+	xCoreID = rtos_core_id_get();
+	ulPortYieldRequired[ xCoreID ] = pdTRUE;
+}
+/*-----------------------------------------------------------*/
+
 DEFINE_RTOS_INTERRUPT_CALLBACK( pxKernelTimerISR, pvData )
 {
 	uint32_t ulLastTrigger;
 	uint32_t ulNow;
+	int xCoreID;
+
+	xCoreID = 0;
+
+	configASSERT( xCoreID == rtos_core_id_get() );
 
 	/* Need the next interrupt to be scheduled relative to
 	 * the current trigger time, rather than the current
@@ -41,14 +56,36 @@ DEFINE_RTOS_INTERRUPT_CALLBACK( pxKernelTimerISR, pvData )
 
 	if( xTaskIncrementTick() != pdFALSE )
 	{
-		ulPortYieldRequired = pdTRUE;
+		ulPortYieldRequired[ xCoreID ] = pdTRUE;
 	}
 }
 /*-----------------------------------------------------------*/
 
-static void prvCoreInit( void )
+void vPortYieldOtherCore( int xOtherCoreID )
 {
-	rtos_core_register();
+	int xCoreID;
+
+	/*
+	 * This function must be called from within a critical section.
+	 */
+
+	xCoreID = rtos_core_id_get();
+
+//	debug_printf("%d->%d\n", xCoreID, xOtherCoreID);
+
+//	debug_printf("Yield core %d from %d\n", xOtherCoreID, xCoreID );
+
+	rtos_irq( xOtherCoreID, xCoreID );
+}
+/*-----------------------------------------------------------*/
+
+static int prvCoreInit( void )
+{
+	int xCoreID;
+
+	xCoreID = rtos_core_register();
+	debug_printf( "Logical Core %d initializing as FreeRTOS Core %d\n", get_logical_core_id(), xCoreID );
+
 	asm volatile (
 			"ldap r11, kexcept\n\t"
 			"set kep, r11\n\t"
@@ -57,35 +94,57 @@ static void prvCoreInit( void )
 			: "r11"
 	);
 
-	rtos_irq_enable( 1 );
+	rtos_irq_enable( configNUM_CORES );
 
-	uint32_t ulNow;
+	/*
-	ulNow = hwtimer_get_time( xKernelTimer );
+	 * All threads wait here until all have enabled IRQs
-//	debug_printf( "The time is now (%u)\n", ulNow );
+	 */
+	while( rtos_irq_ready() == pdFALSE );
 
-	ulNow += configCPU_CLOCK_HZ / configTICK_RATE_HZ;
+	if( xCoreID == 0 )
+	{
+		uint32_t ulNow;
+		ulNow = hwtimer_get_time( xKernelTimer );
+//		debug_printf( "The time is now (%u)\n", ulNow );
 
-	triggerable_setup_interrupt_callback( xKernelTimer, NULL, RTOS_INTERRUPT_CALLBACK( pxKernelTimerISR ) );
+		ulNow += configCPU_CLOCK_HZ / configTICK_RATE_HZ;
-	hwtimer_set_trigger_time( xKernelTimer, ulNow );
+
-	triggerable_enable_trigger( xKernelTimer );
+		triggerable_setup_interrupt_callback( xKernelTimer, NULL, RTOS_INTERRUPT_CALLBACK( pxKernelTimerISR ) );
+		hwtimer_set_trigger_time( xKernelTimer, ulNow );
+		triggerable_enable_trigger( xKernelTimer );
+	}
+
+	return xCoreID;
 }
 /*-----------------------------------------------------------*/
 
 DEFINE_RTOS_KERNEL_ENTRY( void, vPortStartSchedulerOnCore, void )
 {
-	prvCoreInit();
+	int xCoreID;
 
-	debug_printf( "FreeRTOS initialized\n" );
+	xCoreID = prvCoreInit();
+
+	#if( configUSE_CORE_INIT_HOOK == 1 )
+	{
+		extern void vApplicationCoreInitHook( BaseType_t xCoreID );
+
+		vApplicationCoreInitHook( xCoreID );
+	}
+	#endif
+
+	debug_printf( "FreeRTOS Core %d initialized\n", xCoreID );
 
 	/*
 	 * Restore the context of the first thread
 	 * to run and jump into it.
 	 */
 	asm volatile (
+			"mov r6, %0\n\t" /* R6 must be the FreeRTOS core ID*/
+			"ldaw r5, dp[pxCurrentTCBs]\n\t" /* R5 must be the TCB list which is indexed by R6 */
 			"bu _freertos_restore_ctx\n\t"
 			: /* no outputs */
-			: /* no inputs */
+			: "r"(xCoreID)
-			: /* nothing is clobbered */
+			: "r5", "r6"
 	);
 }
 /*-----------------------------------------------------------*/
@@ -164,14 +223,22 @@ StackType_t *pxPortInitialiseStack( StackType_t *pxTopOfStack, TaskFunction_t px
 }
 /*-----------------------------------------------------------*/
 
+void vPortStartSMPScheduler( void );
+
 /*
  * See header file for description.
  */
 BaseType_t xPortStartScheduler( void )
 {
+	if( ( configNUM_CORES > portMAX_CORE_COUNT ) || ( configNUM_CORES <= 0 ) )
+	{
+		return pdFAIL;
+	}
+
 	rtos_locks_initialize();
 	xKernelTimer = hwtimer_alloc();
-	RTOS_KERNEL_ENTRY(vPortStartSchedulerOnCore)();
+
+	vPortStartSMPScheduler();
 
 	return pdPASS;
 }

portable/XCC/XCOREAI/port.xc

@@ -0,0 +1,26 @@
+/*
+ * port.xc
+ *
+ *  Created on: Jul 31, 2019
+ *      Author: mbruno
+ */
+
+//#include "rtos_support.h"
+
+extern "C" {
+
+#include "FreeRTOSConfig.h" /* to get configNUM_CORES */
+#ifndef configNUM_CORES
+#define configNUM_CORES 1
+#endif
+
+void __xcore_interrupt_permitted_ugs_vPortStartSchedulerOnCore(void);
+
+} /* extern "C" */
+
+void vPortStartSMPScheduler( void )
+{
+    par (int i = 0; i < configNUM_CORES; i++) {
+        __xcore_interrupt_permitted_ugs_vPortStartSchedulerOnCore();
+    }
+}

portable/XCC/XCOREAI/portasm.S

@@ -21,10 +21,13 @@ kexcept:
   bau r11 //_TrapHandler is at 0x00080080. TODO: Is it always? Why can't I access the symbol _TrapHandler?
 
 _yield:
-  set    sp,     r4  /* Restore the task's SP to save the rest of its context. */
+ {set    sp,     r4                  /* Restore the task's SP to save the rest of its context. */
-  bu _yield_continue /* Skip the ulPortYieldRequired check and jump right to */
+  get    r11,    id}                 /* Get the logical core ID into r11. */
-                     /* the context save and switch. Also skips saving SPC */
+  ldaw   r0,     dp[rtos_core_map]
-                     /* since the kcall handler has already saved it. */
+  ldw    r0,     r0[r11]             /* Translate to the RTOS core ID into r0 */
+  bu _yield_continue                 /* Skip the ulPortYieldRequired check and jump right to */
+                                     /* the context save and switch. Also skips saving SPC */
+                                     /* since the kcall handler has already saved it. */
 
 .align 64
 kcall:
@@ -68,7 +71,7 @@ rtos_interrupt_callback_common:
  {stw    r4,     sp[12]
 /*stw    r11,    sp[19]     already saved by the wrapper function. */
 
-  ldaw   r4,     sp[0]}  /* Get value of current stackpointer into r4 */
+  ldaw   r4,     sp[0]}  /* Get value of current stackpointer into r4. */
 
  {kentsp 0               /* switch to the kernel stack. */
                          /* The value 0 is safe to use since we don't need the SP */
@@ -78,12 +81,16 @@ rtos_interrupt_callback_common:
  {mov    r0,     r11     /* into the first argument for the callback function... */
   bla    r1}             /* and call the callback function. */
 
-  set    sp,     r4      /* Restore the task's SP now. */
+ {set    sp,     r4      /* Restore the task's SP now. */
-
+ 
-  ldw    r0,     dp[ulPortYieldRequired]       /* Is a yield required? */
+  get    r11,    id}                           /* Get the logical core ID into r11. */
- {bf     r0,     _freertos_restore_ctx_partial /* If not, restore the context now. */
+  ldaw   r0,     dp[rtos_core_map]
-  ldc    r0,     0}
+  ldw    r0,     r0[r11]                       /* Translate to the RTOS core ID into r0. */
-  stw    r0,     dp[ulPortYieldRequired]       /* Otherwise, clear the yield required flag. */
+  ldaw   r2,     dp[ulPortYieldRequired]       /* Get the yield required array into r2. */
+  ldw    r1,     r2[r0]                        /* Is a yield required for this core? */
+ {bf     r1,     _freertos_restore_ctx_partial /* If not, restore the context now. */
+  ldc    r1,     0}
+  stw    r1,     r2[r0]                        /* Otherwise, clear the yield required flag. */
 
   /* Save the rest of the current task's context. */
 
@@ -113,14 +120,17 @@ _yield_continue:
   ldaw   r11,    sp[37]}
   vstc   r11[0]
 #endif
-  ldw    r0,     dp[pxCurrentTCB] /* Save the current task's SP to the first */
+  ldaw   r5,     dp[pxCurrentTCBs] /* Get the current TCB array into r5. */
-  stw    r4,     r0[0x0]          /* word (top of stack) in the current TCB */
+  ldw    r1,     r5[r0]            /* Get this core's current TCB pointer into r1. */
+  stw    r4,     r1[0x0]           /* Save the current task's SP to the first */
+                                   /* word (top of stack) in the current TCB. */
 
-  kentsp 0                        /* switch back to the kernel stack. */
+ {kentsp 0                         /* switch back to the kernel stack. */
 
+  mov    r6,     r0}               /* copy the RTOS core ID into r6 so we don't lose it. */
   ldap   r11,    vTaskSwitchContext
-  bla    r11             /* Finally call vTaskSwitchContext() now that the task's */
+  bla    r11             /* Finally call vTaskSwitchContext(core_id) now that the task's */
-                         /* entire context is saved. */
+                         /* entire context is saved. Note the core id in r0 is the argument. */
 
 //krestsp 0              /* unnecessary since KSP is already set and the SP */
                          /* is being restored next from the current TCB. */
@@ -128,7 +138,7 @@ _yield_continue:
 .globl _freertos_restore_ctx
 _freertos_restore_ctx:
 
-  ldw    r0,     dp[pxCurrentTCB]
+  ldw    r0,     r5[r6]  /* get this core's current TCB pointer into r0 */
   ldw    r0,     r0[0x0] /* Get the top of the stack from the current TCB... */
   set    sp,     r0      /* into the stack pointer register. */
 

portable/XCC/XCOREAI/portmacro.h

@@ -46,9 +46,9 @@ typedef uint32_t UBaseType_t;
 #define portTICK_PERIOD_MS			  ( ( TickType_t ) 1000 / configTICK_RATE_HZ )
 #define portBYTE_ALIGNMENT			  8
 #define portCRITICAL_NESTING_IN_TCB   1
-#ifdef configNUM_CORES
+#define portMAX_CORE_COUNT            8
-#warning configNUM_CORES should not be defined when using the single core XCORE port
+#ifndef configNUM_CORES
-#undef configNUM_CORES
+#define configNUM_CORES               1
 #endif
 
 /* This may be set to zero in the config file if the rtos_time
@@ -67,6 +67,12 @@ functions are not needed or if it is incremented elsewhere. */
 #define portTHREAD_CONTEXT_STACK_GROWTH RTOS_SUPPORT_INTERRUPT_STACK_GROWTH
 
 #ifndef __ASSEMBLER__
+
+/* Check validity of number of cores specified in config */
+#if ( configNUM_CORES < 1 || portMAX_CORE_COUNT < configNUM_CORES )
+#error "Invalid number of cores specified in config!"
+#endif
+
 #define portMEMORY_BARRIER() RTOS_MEMORY_BARRIER()
 #define portTASK_STACK_DEPTH(pxTaskCode) RTOS_THREAD_STACK_SIZE(pxTaskCode)
 /*-----------------------------------------------------------*/
@@ -79,17 +85,24 @@ do \
 { \
 	if( xSwitchRequired != pdFALSE ) \
 	{ \
-		extern uint32_t ulPortYieldRequired; \
+		extern uint32_t ulPortYieldRequired[ portMAX_CORE_COUNT ]; \
-	    ulPortYieldRequired = pdTRUE; \
+	    ulPortYieldRequired[ portGET_CORE_ID() ] = pdTRUE; \
 	} \
 } while( 0 )
 
 #define portYIELD_FROM_ISR( x ) portEND_SWITCHING_ISR( x )
 /*-----------------------------------------------------------*/
 
+/* SMP utilities. */
+#define portGET_CORE_ID() rtos_core_id_get()
+
+void vPortYieldOtherCore( int xOtherCoreID );
+#define portYIELD_CORE( x ) vPortYieldOtherCore( x )
+/*-----------------------------------------------------------*/
+
 /* Architecture specific optimisations. */
 #ifndef configUSE_PORT_OPTIMISED_TASK_SELECTION
-#define configUSE_PORT_OPTIMISED_TASK_SELECTION 1
+#define configUSE_PORT_OPTIMISED_TASK_SELECTION 0
 #endif
 
 #if configUSE_PORT_OPTIMISED_TASK_SELECTION == 1
@@ -108,10 +121,16 @@ do \
 /* Critical section management. */
 
 #define portGET_INTERRUPT_STATE() rtos_interrupt_mask_get()
+
+/*
+ * This differs from the standard portDISABLE_INTERRUPTS()
+ * in that it also returns what the interrupt state was
+ * before it disabling interrupts.
+ */
 #define portDISABLE_INTERRUPTS() rtos_interrupt_mask_all()
+
 #define portENABLE_INTERRUPTS() rtos_interrupt_unmask_all()
-#define portSET_INTERRUPT_MASK_FROM_ISR() 0
+
-#define portCLEAR_INTERRUPT_MASK_FROM_ISR(x)
 /*
  * Will enable interrupts if ulState is non-zero.
  */
@@ -122,12 +141,43 @@ do \
  * ISR or otherwise in kernel mode.
  */
 #define portCHECK_IF_IN_ISR() rtos_isr_running()
+
 #define portASSERT_IF_IN_ISR() configASSERT( portCHECK_IF_IN_ISR() == 0 )
 
+#define portGET_ISR_LOCK()      rtos_lock_acquire(0)
+#define portRELEASE_ISR_LOCK()  rtos_lock_release(0)
+#define portGET_TASK_LOCK()     rtos_lock_acquire(1)
+#define portRELEASE_TASK_LOCK() rtos_lock_release(1)
+
 void vTaskEnterCritical(void);
 void vTaskExitCritical(void);
-#define portENTER_CRITICAL()					vTaskEnterCritical()
+#define portENTER_CRITICAL()                   vTaskEnterCritical()
-#define portEXIT_CRITICAL()						vTaskExitCritical()
+#define portEXIT_CRITICAL()                    vTaskExitCritical()
+
+/*
+ * vTaskEnterCritical() has been modified to be safe to use
+ * from within ISRs. The previous mask does not need to be
+ * returned since in the xCORE interrupts are always disabled
+ * in ISRs. Effectively this call just grabs the kernel lock
+ * when called from an ISR.
+ */
+static inline uint32_t portSET_INTERRUPT_MASK_FROM_ISR( void )
+{
+	vTaskEnterCritical();
+	return 0;
+}
+#define portSET_INTERRUPT_MASK_FROM_ISR() portSET_INTERRUPT_MASK_FROM_ISR()
+
+/*
+ * vTaskExitCritical() has been modified to be safe to use
+ * from within ISRs. When the nesting level has reached zero
+ * it releases the lock, but when called from within an ISR
+ * it will *not* re-enable interrupts since it is assumed they
+ * were previously disabled. Thus the previous state in x is
+ * unused.
+ */
+#define portCLEAR_INTERRUPT_MASK_FROM_ISR(x)   vTaskExitCritical()
+
 /*-----------------------------------------------------------*/
 
 /* Runtime stats support */

portable/XCC/XCOREAI/rtos_support_rtos_config.h

@@ -35,7 +35,10 @@
  * The RTOS provided handler that should run when a
  * core receives an intercore interrupt request.
  */
-#define RTOS_INTERCORE_INTERRUPT_ISR()
+#define RTOS_INTERCORE_INTERRUPT_ISR() do { \
+	void vIntercoreInterruptISR( void ); \
+	vIntercoreInterruptISR(); \
+} while ( 0 )
 
 /**
  * The number of hardware locks that the RTOS
@@ -45,7 +48,7 @@
  * Note that the IRQ routines require a lock and
  * will share the first one with the RTOS.
  */
-#define RTOS_LOCK_COUNT 0
+#define RTOS_LOCK_COUNT 2
 
 /**
  * Remaps all calls to debug_printf() to rtos_printf().
@@ -64,6 +67,15 @@
 		#endif
 		#define DEBUG_PRINT_ENABLE 1
 
+		#ifndef configTASKS_DEBUG
+			#define configTASKS_DEBUG 0
+		#endif
+		#if configTASKS_DEBUG == 1
+			#define DEBUG_PRINT_ENABLE_FREERTOS_TASKS 1
+		#else
+			#define DEBUG_PRINT_DISABLE_FREERTOS_TASKS 1
+		#endif
+
 	#else /* configENABLE_DEBUG_PRINTF */
 
 		/* ensure that debug_printf is disabled */

queue.c

@@ -87,7 +87,7 @@ typedef struct SemaphoreData
  * performed just because a higher priority task has been woken. */
     #define queueYIELD_IF_USING_PREEMPTION()
 #else
-    #define queueYIELD_IF_USING_PREEMPTION()    portYIELD_WITHIN_API()
+    #define queueYIELD_IF_USING_PREEMPTION()    vTaskYieldWithinAPI()
 #endif
 
 /*
@@ -957,7 +957,7 @@ BaseType_t xQueueGenericSend( QueueHandle_t xQueue,
                  * is also a higher priority task in the pending ready list. */
                 if( xTaskResumeAll() == pdFALSE )
                 {
-                    portYIELD_WITHIN_API();
+                    vTaskYieldWithinAPI();
                 }
             }
             else
@@ -1422,7 +1422,7 @@ BaseType_t xQueueReceive( QueueHandle_t xQueue,
 
                 if( xTaskResumeAll() == pdFALSE )
                 {
-                    portYIELD_WITHIN_API();
+                    vTaskYieldWithinAPI();
                 }
                 else
                 {
@@ -1614,7 +1614,7 @@ BaseType_t xQueueSemaphoreTake( QueueHandle_t xQueue,
 
                 if( xTaskResumeAll() == pdFALSE )
                 {
-                    portYIELD_WITHIN_API();
+                    vTaskYieldWithinAPI();
                 }
                 else
                 {
@@ -1792,7 +1792,7 @@ BaseType_t xQueuePeek( QueueHandle_t xQueue,
 
                 if( xTaskResumeAll() == pdFALSE )
                 {
-                    portYIELD_WITHIN_API();
+                    vTaskYieldWithinAPI();
                 }
                 else
                 {

timers.c

@@ -1,7 +1,6 @@
 /*
  * FreeRTOS Kernel V10.4.3
  * Copyright (C) 2020 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
-
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy of
  * this software and associated documentation files (the "Software"), to deal in
@@ -669,7 +668,7 @@
                          * block time to expire.  If a command arrived between the
                          * critical section being exited and this yield then the yield
                          * will not cause the task to block. */
-                        portYIELD_WITHIN_API();
+                        vTaskYieldWithinAPI();
                     }
                     else
                     {