Performance optimisation.

git-svn-id: http://svn.code.sf.net/p/freertos/code/trunk@251 1d2547de-c912-0410-9cb9-b8ca96c0e9e2

2 files changed, 62 insertions, 96 deletions

diff --git a/Source/portable/IAR/ARM_CM3/port.c b/Source/portable/IAR/ARM_CM3/port.c
index 87caec32d..1a744bcf5 100644
--- a/Source/portable/IAR/ARM_CM3/port.c
+++ b/Source/portable/IAR/ARM_CM3/port.c
@@ -25,11 +25,11 @@
 

 	***************************************************************************

 

-	Please ensure to read the configuration and relevant port sections of the 

+	Please ensure to read the configuration and relevant port sections of the

 	online documentation.

 

 	+++ http://www.FreeRTOS.org +++

-	Documentation, latest information, license and contact details.  

+	Documentation, latest information, license and contact details.

 

 	+++ http://www.SafeRTOS.com +++

 	A version that is certified for use in safety critical systems.

@@ -60,7 +60,6 @@
 #define portNVIC_SYSTICK_LOAD		( ( volatile unsigned portLONG *) 0xe000e014 )

 #define portNVIC_INT_CTRL			( ( volatile unsigned portLONG *) 0xe000ed04 )

 #define portNVIC_SYSPRI2			( ( volatile unsigned portLONG *) 0xe000ed20 )

-#define portNVIC_SYSPRI1			( ( volatile unsigned portLONG *) 0xe000ed1c )

 #define portNVIC_SYSTICK_CLK		0x00000004

 #define portNVIC_SYSTICK_INT		0x00000002

 #define portNVIC_SYSTICK_ENABLE		0x00000001

@@ -88,16 +87,14 @@ unsigned portBASE_TYPE uxCriticalNesting = 0xaaaaaaaa;
 static void prvSetupTimerInterrupt( void );

 

 /*

- * Set the MSP/PSP to a known value.

+ * Exception handlers.

  */

-extern void vSetMSP( unsigned long ulValue );

-extern void vSetPSP( unsigned long ulValue );

+void xPortSysTickHandler( void );

 

 /*

- * Utilities called from the assembler code.

+ * Start first task is a separate function so it can be tested in isolation.

  */

-void vPortSwitchContext( void );

-void vPortIncrementTick( void );

+extern void vPortStartFirstTask( unsigned portLONG ulValue );

 

 /*-----------------------------------------------------------*/

 

@@ -112,7 +109,7 @@ portSTACK_TYPE *pxPortInitialiseStack( portSTACK_TYPE *pxTopOfStack, pdTASK_CODE
 	pxTopOfStack--;

 	*pxTopOfStack = ( portSTACK_TYPE ) pxCode;	/* PC */

 	pxTopOfStack--;

-	*pxTopOfStack = 0xfffffffd;	/* LR */

+	*pxTopOfStack = 0;	/* LR */

 	pxTopOfStack -= 5;	/* R12, R3, R2 and R1. */

 	*pxTopOfStack = ( portSTACK_TYPE ) pvParameters;	/* R0 */

 	pxTopOfStack -= 9;	/* R11, R10, R9, R8, R7, R6, R5 and R4. */

@@ -136,12 +133,7 @@ portBASE_TYPE xPortStartScheduler( void )
 	prvSetupTimerInterrupt();

 	

 	/* Start the first task. */

-	vSetPSP( 0 );

-	vSetMSP( *((unsigned portLONG *) 0 ) );

-	*(portNVIC_INT_CTRL) |= portNVIC_PENDSVSET;

-

-	/* Enable interrupts */

-	portENABLE_INTERRUPTS();

+	vPortStartFirstTask( *((unsigned portLONG *) 0 ) );

 

 	/* Should not get here! */

 	return 0;

@@ -183,6 +175,16 @@ void vPortExitCritical( void )
 }

 /*-----------------------------------------------------------*/

 

+void xPortSysTickHandler( void )

+{

+	vTaskIncrementTick();

+	

+	/* If using preemption, also force a context switch. */

+	#if configUSE_PREEMPTION == 1

+		*(portNVIC_INT_CTRL) |= portNVIC_PENDSVSET;	

+	#endif

+}

+/*-----------------------------------------------------------*/

 

 /*

  * Setup the systick timer to generate the tick interrupts at the required

@@ -196,19 +198,3 @@ void prvSetupTimerInterrupt( void )
 }

 /*-----------------------------------------------------------*/

 

-void vPortSwitchContext( void )

-{

-	vPortSetInterruptMask();

-	vTaskSwitchContext();

-	vPortClearInterruptMask();

-}

-/*-----------------------------------------------------------*/

-

-void vPortIncrementTick( void )

-{

-	vPortSetInterruptMask();

-	vTaskIncrementTick();

-	vPortClearInterruptMask();

-}

-

-

diff --git a/Source/portable/IAR/ARM_CM3/portasm.s b/Source/portable/IAR/ARM_CM3/portasm.s
index 32e79796b..ad2cde1fe 100644
--- a/Source/portable/IAR/ARM_CM3/portasm.s
+++ b/Source/portable/IAR/ARM_CM3/portasm.s
@@ -25,11 +25,11 @@
 

 	***************************************************************************

 

-	Please ensure to read the configuration and relevant port sections of the 

+	Please ensure to read the configuration and relevant port sections of the

 	online documentation.

 

 	+++ http://www.FreeRTOS.org +++

-	Documentation, latest information, license and contact details.  

+	Documentation, latest information, license and contact details.

 

 	+++ http://www.SafeRTOS.com +++

 	A version that is certified for use in safety critical systems.

@@ -61,23 +61,18 @@ FreeRTOS.org versions prior to V4.3.0 did not include this definition. */
 	thumb

 

 	EXTERN vPortYieldFromISR

-	EXTERN vPortSwitchContext

-	EXTERN vPortIncrementTick

 	EXTERN uxCriticalNesting

 	EXTERN pxCurrentTCB

+	EXTERN vTaskSwitchContext

 

-	PUBLIC vSetPSP

 	PUBLIC vSetMSP

 	PUBLIC xPortPendSVHandler

-	PUBLIC xPortSysTickHandler

 	PUBLIC vPortSetInterruptMask

 	PUBLIC vPortClearInterruptMask

+	PUBLIC vPortSVCHandler

+	PUBLIC vPortStartFirstTask

 

 

-vSetPSP:

-	msr psp, r0

-	bx lr

-	

 /*-----------------------------------------------------------*/

 

 vSetMSP

@@ -88,67 +83,34 @@ vSetMSP
 

 xPortPendSVHandler:

 	mrs r0, psp						

-	cbz r0, no_save					

-	/* Save the context into the TCB. */

-	stmdb r0!, {r4-r11}				

-	sub r0, r0, #0x04					

-	ldr r1, =uxCriticalNesting

-	ldr r2, =pxCurrentTCB		

-	ldr r1, [r1]					

-	ldr r2, [r2]					

-	str r1, [r0]					

-	str r0, [r2]					

-									

-no_save:

-	push {r14}						

-	bl vPortSwitchContext			

-	pop {r14}						

-	/* Restore the context. */		

-	ldr r1, =pxCurrentTCB

+	ldr	r3, =pxCurrentTCB			/* Get the location of the current TCB. */

+	ldr	r2, [r3]						

+

+	ldr r1, =uxCriticalNesting		/* Save the remaining registers and the critical nesting count onto the task stack. */

 	ldr r1, [r1]					

-	ldr r0, [r1]					

-	ldmia r0!, {r1, r4-r11}			

-	ldr r2, =uxCriticalNesting

-	str r1, [r2]					

+	stmdb r0!, {r1,r4-r11}			

+	str r0, [r2]					/* Save the new top of stack into the first member of the TCB. */

+

+	stmdb sp!, {r3, r14}			

+	bl vTaskSwitchContext			

+	ldmia sp!, {r3, r14}			

+

+	ldr r1, [r3]					

+	ldr r2, =uxCriticalNesting	

+	ldr r0, [r1]					/* The first item in pxCurrentTCB is the task top of stack. */

+	ldmia r0!, {r1, r4-r11}			/* Pop the registers and the critical nesting count. */

+	str r1, [r2]					/* Save the new critical nesting value into ulCriticalNesting. */

 	msr psp, r0						

-	orr r14, r14, #0xd					

-	/* Exit with interrupts in the state required by the task. */

-	cbnz r1, sv_disable_interrupts	

+	orr r14, r14, #13			

+

+	cbnz r1, sv_disable_interrupts	/* If the nesting count is greater than 0 we need to exit with interrupts masked. */

 	bx r14							

-									

+

 sv_disable_interrupts:				

 	mov	r1, #configKERNEL_INTERRUPT_PRIORITY

-	msr	basepri, R1

+	msr	basepri, r1

 	bx r14							

 

-

-/*-----------------------------------------------------------*/

-

-xPortSysTickHandler:

-	/* Call the scheduler tick function. */

-	push {r14}

-	bl vPortIncrementTick

-	pop {r14}

-	

-	/* If using preemption, also force a context switch. */

-	#if configUSE_PREEMPTION == 1

-		push {r14}

-		bl vPortYieldFromISR

-		pop {r14}

-	#endif

-

-	/* Exit with interrupts in the correct state. */

-    ldr r2, =uxCriticalNesting

-	ldr r2, [r2]

-	cbnz r2, tick_disable_interrupts

-	bx r14

-

-tick_disable_interrupts:

-	mov	r1, #configKERNEL_INTERRUPT_PRIORITY

-	msr	basepri, R1

-	

-	bx r14

-

 /*-----------------------------------------------------------*/

 

 vPortSetInterruptMask:

@@ -171,5 +133,23 @@ vPortClearInterruptMask:
 

 /*-----------------------------------------------------------*/

 

+vPortSVCHandler;

+	ldr	r3, =pxCurrentTCB

+	ldr r1, [r3]

+	ldr r0, [r1]

+	ldmia r0!, {r1, r4-r11}

+	ldr r2, =uxCriticalNesting

+	str r1, [r2]

+	msr psp, r0

+	orr r14, r14, #13

+	bx r14

+

+/*-----------------------------------------------------------*/

+

+vPortStartFirstTask

+	msr msp, r0

+	svc 0

+

+

 	END

 	
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