From 30e13dac2bd97b7c1429cdead03406d94a83a042 Mon Sep 17 00:00:00 2001
From: chinglee-iot <61685396+chinglee-iot@users.noreply.github.com>
Date: Wed, 4 Oct 2023 19:33:28 +0800
Subject: [PATCH] Implement prvYieldCore with macro (#785)

* Implement prvYieldCore with macro for performance and memory
* Remove the portCHECK_IF_IN_ISR macro check. It is not required in SMP
  now

Co-authored-by: kar-rahul-aws <118818625+kar-rahul-aws@users.noreply.github.com>
Co-authored-by: Gaurav-Aggarwal-AWS <33462878+aggarg@users.noreply.github.com>
---
 include/FreeRTOS.h |  8 -------
 tasks.c            | 60 +++++++++++++++++++---------------------------
 2 files changed, 25 insertions(+), 43 deletions(-)

diff --git a/include/FreeRTOS.h b/include/FreeRTOS.h
index d0d63f1a22f..712d8cb52fe 100644
--- a/include/FreeRTOS.h
+++ b/include/FreeRTOS.h
@@ -453,14 +453,6 @@
 
 #endif /* portGET_ISR_LOCK */
 
-#ifndef portCHECK_IF_IN_ISR
-
-    #if ( configNUMBER_OF_CORES > 1 )
-        #error portCHECK_IF_IN_ISR is required in SMP
-    #endif
-
-#endif /* portCHECK_IF_IN_ISR */
-
 #ifndef portENTER_CRITICAL_FROM_ISR
 
     #if ( configNUMBER_OF_CORES > 1 )
diff --git a/tasks.c b/tasks.c
index 000767bb5e5..e0fc15bcc65 100644
--- a/tasks.c
+++ b/tasks.c
@@ -325,6 +325,31 @@
 
 #define taskBITS_PER_BYTE    ( ( size_t ) 8 )
 
+#if ( configNUMBER_OF_CORES > 1 )
+
+/* Yields the given core. This must be called from a critical section and xCoreID
+ * must be valid. This macro is not required in single core since there is only
+ * one core to yield. */
+    #define prvYieldCore( xCoreID )                                                      \
+    do {                                                                                 \
+        if( xCoreID == ( BaseType_t ) portGET_CORE_ID() )                                \
+        {                                                                                \
+            /* Pending a yield for this core since it is in the critical section. */     \
+            xYieldPendings[ xCoreID ] = pdTRUE;                                          \
+        }                                                                                \
+        else                                                                             \
+        {                                                                                \
+            /* Request other core to yield if it is not requested before. */             \
+            if( pxCurrentTCBs[ xCoreID ]->xTaskRunState != taskTASK_SCHEDULED_TO_YIELD ) \
+            {                                                                            \
+                portYIELD_CORE( xCoreID );                                               \
+                pxCurrentTCBs[ xCoreID ]->xTaskRunState = taskTASK_SCHEDULED_TO_YIELD;   \
+            }                                                                            \
+        }                                                                                \
+    } while( 0 )
+#endif /* #if ( configNUMBER_OF_CORES > 1 ) */
+/*-----------------------------------------------------------*/
+
 /*
  * Task control block.  A task control block (TCB) is allocated for each task,
  * and stores task state information, including a pointer to the task's context
@@ -527,14 +552,6 @@ static BaseType_t prvCreateIdleTasks( void );
 
 #if ( configNUMBER_OF_CORES > 1 )
 
-/*
- * Yields the given core.
- */
-    static void prvYieldCore( BaseType_t xCoreID );
-#endif /* #if ( configNUMBER_OF_CORES > 1 ) */
-
-#if ( configNUMBER_OF_CORES > 1 )
-
 /*
  * Yields a core, or cores if multiple priorities are not allowed to run
  * simultaneously, to allow the task pxTCB to run.
@@ -811,33 +828,6 @@ static void prvAddNewTaskToReadyList( TCB_t * pxNewTCB ) PRIVILEGED_FUNCTION;
 
 /*-----------------------------------------------------------*/
 
-#if ( configNUMBER_OF_CORES > 1 )
-    static void prvYieldCore( BaseType_t xCoreID )
-    {
-        /* This must be called from a critical section and xCoreID must be valid. */
-        if( ( portCHECK_IF_IN_ISR() == pdTRUE ) && ( xCoreID == ( BaseType_t ) portGET_CORE_ID() ) )
-        {
-            xYieldPendings[ xCoreID ] = pdTRUE;
-        }
-        else
-        {
-            if( pxCurrentTCBs[ xCoreID ]->xTaskRunState != taskTASK_SCHEDULED_TO_YIELD )
-            {
-                if( xCoreID == ( BaseType_t ) portGET_CORE_ID() )
-                {
-                    xYieldPendings[ xCoreID ] = pdTRUE;
-                }
-                else
-                {
-                    portYIELD_CORE( xCoreID );
-                    pxCurrentTCBs[ xCoreID ]->xTaskRunState = taskTASK_SCHEDULED_TO_YIELD;
-                }
-            }
-        }
-    }
-#endif /* #if ( configNUMBER_OF_CORES > 1 ) */
-/*-----------------------------------------------------------*/
-
 #if ( configNUMBER_OF_CORES > 1 )
     static void prvYieldForTask( const TCB_t * pxTCB )
     {