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Commit 33c627db authored by Richard Barry's avatar Richard Barry
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Introduce configKERNEL_INTERRUPT_PRIORITY and make some performance optimisations.

git-svn-id: http://svn.code.sf.net/p/freertos/code/trunk@265 1d2547de-c912-0410-9cb9-b8ca96c0e9e2
parent 0d04fe85
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......@@ -40,13 +40,6 @@
***************************************************************************
*/
/*
Changes between V4.0.0 and V4.0.1
+ Reduced the code used to setup the initial stack frame.
+ The kernel no longer has to install or handle the fault interrupt.
*/
/*-----------------------------------------------------------
* Implementation of functions defined in portable.h for the ARM CM3 port.
*----------------------------------------------------------*/
......@@ -55,21 +48,21 @@
#include "FreeRTOS.h"
#include "task.h"
#ifndef configKERNEL_INTERRUPT_PRIORITY
#define configKERNEL_INTERRUPT_PRIORITY 255
#endif
/* Constants required to manipulate the NVIC. */
#define portNVIC_SYSTICK_CTRL ( ( volatile unsigned portLONG *) 0xe000e010 )
#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_HARD_FAULT_STATUS 0xe000ed2c
#define portNVIC_FORCED_FAULT_BIT 0x40000000
#define portNVIC_SYSTICK_CLK 0x00000004
#define portNVIC_SYSTICK_INT 0x00000002
#define portNVIC_SYSTICK_ENABLE 0x00000001
#define portNVIC_PENDSVSET 0x10000000
#define portNVIC_PENDSV_PRI 0x00ff0000
#define portNVIC_SVCALL_PRI 0xff000000
#define portNVIC_SYSTICK_PRI 0xff000000
#define portNVIC_PENDSV_PRI ( ( ( unsigned portLONG ) configKERNEL_INTERRUPT_PRIORITY ) << 16 )
#define portNVIC_SYSTICK_PRI ( ( ( unsigned portLONG ) configKERNEL_INTERRUPT_PRIORITY ) << 24 )
/* Constants required to set up the initial stack. */
#define portINITIAL_XPSR ( 0x01000000 )
......@@ -78,22 +71,22 @@
variable. */
unsigned portBASE_TYPE uxCriticalNesting = 0xaaaaaaaa;
/* Constant hardware definitions to assist asm code. */
const unsigned long ulHardFaultStatus = portNVIC_HARD_FAULT_STATUS;
const unsigned long ulNVICIntCtrl = ( unsigned long ) 0xe000ed04;
const unsigned long ulForceFaultBit = portNVIC_FORCED_FAULT_BIT;
const unsigned long ulPendSVBit = portNVIC_PENDSVSET;
/*
* Setup the timer to generate the tick interrupts.
*/
static void prvSetupTimerInterrupt( void );
/*
* Set the MSP/PSP to a known value.
* Exception handlers.
*/
void prvSetMSP( unsigned long ulValue );
void prvSetPSP( unsigned long ulValue );
void xPortPendSVHandler( void );
void xPortSysTickHandler( void );
void vPortSVCHandler( void );
/*
* Start first task is a separate function so it can be tested in isolation.
*/
void vPortStartFirstTask( unsigned long ulValue );
/*-----------------------------------------------------------*/
......@@ -108,7 +101,7 @@ 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. */
......@@ -118,19 +111,28 @@ portSTACK_TYPE *pxPortInitialiseStack( portSTACK_TYPE *pxTopOfStack, pdTASK_CODE
}
/*-----------------------------------------------------------*/
__asm void prvSetPSP( unsigned long ulValue )
__asm void vPortSVCHandler( void )
{
PRESERVE8
msr psp, r0
bx lr;
ldr r3, =pxCurrentTCB /* Restore the context. */
ldr r1, [r3] /* Use pxCurrentTCBConst to get the pxCurrentTCB address. */
ldr r0, [r1] /* The first item in pxCurrentTCB is the task top of stack. */
ldmia r0!, {r1, r4-r11} /* Pop the registers that are not automatically saved on exception entry and the critical nesting count. */
ldr r2, =uxCriticalNesting /* Restore the critical nesting count used by the task. */
str r1, [r2]
msr psp, r0 /* Restore the task stack pointer. */
orr r14, #0xd
bx r14
}
/*-----------------------------------------------------------*/
__asm void prvSetMSP( unsigned long ulValue )
__asm void vPortStartFirstTask( unsigned long ulValue )
{
PRESERVE8
msr msp, r0
bx lr;
msr msp, r0 /* Set the msp back to the start of the stack. */
svc 0 /* System call to start first task. */
}
/*-----------------------------------------------------------*/
......@@ -139,22 +141,16 @@ __asm void prvSetMSP( unsigned long ulValue )
*/
portBASE_TYPE xPortStartScheduler( void )
{
/* Start the timer that generates the tick ISR. Interrupts are disabled
here already. */
prvSetupTimerInterrupt();
/* Make PendSV, CallSV and SysTick the lowest priority interrupts. */
/* Make PendSV, CallSV and SysTick the same priroity as the kernel. */
*(portNVIC_SYSPRI2) |= portNVIC_PENDSV_PRI;
*(portNVIC_SYSPRI2) |= portNVIC_SYSTICK_PRI;
*(portNVIC_SYSPRI1) |= portNVIC_SVCALL_PRI;
/* Start the timer that generates the tick ISR. Interrupts are disabled
here already. */
prvSetupTimerInterrupt();
/* Start the first task. */
prvSetPSP( 0 );
prvSetMSP( *((unsigned portLONG *) 0 ) );
*(portNVIC_INT_CTRL) |= portNVIC_PENDSVSET;
/* Enable interrupts */
portENABLE_INTERRUPTS();
vPortStartFirstTask( *((unsigned portLONG *) 0 ) );
/* Should not get here! */
return 0;
......@@ -171,30 +167,17 @@ void vPortEndScheduler( void )
void vPortYieldFromISR( void )
{
/* Set a PendSV to request a context switch. */
*(portNVIC_INT_CTRL) |= portNVIC_PENDSVSET;
portENABLE_INTERRUPTS();
}
/*-----------------------------------------------------------*/
__asm void vPortDisableInterrupts( void )
{
PRESERVE8
cpsid i;
bx lr;
}
/*-----------------------------------------------------------*/
*(portNVIC_INT_CTRL) |= portNVIC_PENDSVSET;
__asm void vPortEnableInterrupts( void )
{
PRESERVE8
cpsie i;
bx lr;
/* This function is also called in response to a Yield(), so we want
the yield to occur immediately. */
portENABLE_INTERRUPTS();
}
/*-----------------------------------------------------------*/
void vPortEnterCritical( void )
{
vPortDisableInterrupts();
portDISABLE_INTERRUPTS();
uxCriticalNesting++;
}
/*-----------------------------------------------------------*/
......@@ -204,7 +187,7 @@ void vPortExitCritical( void )
uxCriticalNesting--;
if( uxCriticalNesting == 0 )
{
vPortEnableInterrupts();
portENABLE_INTERRUPTS();
}
}
/*-----------------------------------------------------------*/
......@@ -217,81 +200,46 @@ __asm void xPortPendSVHandler( void )
PRESERVE8
/* Start first task if the stack has not yet been setup. */
mrs r0, psp
cbz r0, no_save
mrs r0, psp
/* Save the context into the TCB. */
stmdb r0!, {r4-r11}
sub r0, r0, #0x04
ldr r1, =uxCriticalNesting
ldr r2, =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 r2, [r2]
str r1, [r0]
str r0, [r2]
stmdb r0!, {r1,r4-r11}
str r0, [r2] /* Save the new top of stack into the first member of the TCB. */
no_save;
/* Find the task to execute. */
push {r14}
cpsid i
bl vTaskSwitchContext
cpsie i
pop {r14}
/* Restore the context. */
ldr r1, =pxCurrentTCB
ldr r1, [r1];
ldr r0, [r1];
ldmia r0!, {r1, r4-r11}
stmdb sp!, {r3, r14}
bl vTaskSwitchContext
ldmia sp!, {r3, r14}
ldr r1, [r3]
ldr r2, =uxCriticalNesting
str r1, [r2]
ldr r2, [r2]
msr psp, r0
orr r14, #0xd
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, #0xd
/* Exit with interrupts in the state required by the task. */
cbnz r2, sv_disable_interrupts
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;
cpsid i
bx r14
sv_disable_interrupts
mov r1, #configKERNEL_INTERRUPT_PRIORITY
msr basepri, r1
bx r14
}
/*-----------------------------------------------------------*/
__asm void xPortSysTickHandler( void )
void xPortSysTickHandler( void )
{
extern vTaskIncrementTick
PRESERVE8
/* Call the scheduler tick function. */
push {r14}
cpsid i
bl vTaskIncrementTick
cpsie i
pop {r14}
vTaskIncrementTick();
/* If using preemption, also force a context switch. */
#if configUSE_PREEMPTION == 1
extern vPortYieldFromISR
push {r14}
bl vPortYieldFromISR
pop {r14}
*(portNVIC_INT_CTRL) |= portNVIC_PENDSVSET;
#endif
/* Exit with interrupts in the correct state. */
ldr r2, =uxCriticalNesting
ldr r2, [r2]
cbnz r2, tick_disable_interrupts
bx r14
tick_disable_interrupts;
cpsid i
bx r14
}
/*-----------------------------------------------------------*/
......@@ -305,5 +253,26 @@ void prvSetupTimerInterrupt( void )
*(portNVIC_SYSTICK_LOAD) = configCPU_CLOCK_HZ / configTICK_RATE_HZ;
*(portNVIC_SYSTICK_CTRL) = portNVIC_SYSTICK_CLK | portNVIC_SYSTICK_INT | portNVIC_SYSTICK_ENABLE;
}
/*-----------------------------------------------------------*/
__asm void vPortSetInterruptMask( void )
{
PRESERVE8
push { r0 }
mov r0, #configKERNEL_INTERRUPT_PRIORITY
msr basepri, r0
pop { r0 }
}
/*-----------------------------------------------------------*/
__asm void vPortClearInterruptMask( void )
{
PRESERVE8
push { r0 }
mov r0, #0
msr basepri, r0
pop { r0 }
}
......@@ -94,13 +94,13 @@ extern void vPortYieldFromISR( void );
/* Critical section management. */
extern void vPortDisableInterrupts( void );
extern void vPortEnableInterrupts( void );
extern void vPortSetInterruptMask( void );
extern void vPortClearInterruptMask( void );
extern void vPortEnterCritical( void );
extern void vPortExitCritical( void );
#define portDISABLE_INTERRUPTS() vPortDisableInterrupts()
#define portENABLE_INTERRUPTS() vPortEnableInterrupts()
#define portDISABLE_INTERRUPTS() vPortSetInterruptMask()
#define portENABLE_INTERRUPTS() vPortClearInterruptMask()
#define portENTER_CRITICAL() vPortEnterCritical()
#define portEXIT_CRITICAL() vPortExitCritical()
/*-----------------------------------------------------------*/
......
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