]> git.sur5r.net Git - freertos/blobdiff - FreeRTOS/Source/portable/GCC/ARM_CM3/port.c
Added portASSERT_IF_INTERRUPT_PRIORITY_INVALID() implementation to Cortex-M3 and...
[freertos] / FreeRTOS / Source / portable / GCC / ARM_CM3 / port.c
index e9acf2eaa96dce1fce07f0f396b0d99a5d771c4f..a3d652f12a9913903a00dce8d855cea63728a339 100644 (file)
@@ -107,6 +107,12 @@ FreeRTOS.org versions prior to V4.4.0 did not include this definition. */
 #define portNVIC_PENDSV_PRI                                    ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 16UL )\r
 #define portNVIC_SYSTICK_PRI                           ( ( ( unsigned long ) configKERNEL_INTERRUPT_PRIORITY ) << 24UL )\r
 \r
+/* Constants required to check the validity of an interrupt prority. */\r
+#define portFIRST_USER_INTERRUPT_NUMBER                ( 16 )\r
+#define portNVIC_IP_REGISTERS_OFFSET_16        ( 0xE000E3F0 )\r
+#define portAIRCR_REG                                          ( * ( ( volatile unsigned long * ) 0xE000ED0C ) )\r
+#define portPRIORITY_GROUP_MASK                                ( 0x07UL << 8UL )\r
+\r
 /* Constants required to set up the initial stack. */\r
 #define portINITIAL_XPSR                                       ( 0x01000000 )\r
 \r
@@ -166,6 +172,16 @@ static void prvPortStartFirstTask( void ) __attribute__ (( naked ));
        static unsigned long ulStoppedTimerCompensation = 0;\r
 #endif /* configUSE_TICKLESS_IDLE */\r
 \r
+/*\r
+ * Used by the portASSERT_IF_INTERRUPT_PRIORITY_INVALID() macro to ensure \r
+ * FreeRTOS API functions are not called from interrupts that have been assigned\r
+ * a priority above configMAX_SYSCALL_INTERRUPT_PRIORITY.\r
+ */\r
+#if ( configASSERT_DEFINED == 1 )\r
+        static unsigned char ucMaxSysCallPriority = 0;\r
+        static const volatile unsigned char * const pcInterruptPriorityRegisters = ( const volatile unsigned char * const ) portNVIC_IP_REGISTERS_OFFSET_16;\r
+#endif /* configASSERT_DEFINED */\r
+\r
 /*-----------------------------------------------------------*/\r
 \r
 /*\r
@@ -231,6 +247,33 @@ portBASE_TYPE xPortStartScheduler( void )
        See http://www.FreeRTOS.org/RTOS-Cortex-M3-M4.html */\r
        configASSERT( configMAX_SYSCALL_INTERRUPT_PRIORITY );\r
 \r
+       #if( configASSERT_DEFINED == 1 )\r
+       {\r
+               volatile unsigned long ulOriginalPriority;\r
+               volatile char * const pcFirstUserPriorityRegister = ( volatile char * const ) ( portNVIC_IP_REGISTERS_OFFSET_16 + portFIRST_USER_INTERRUPT_NUMBER );\r
+\r
+               /* Determine the maximum priority from which ISR safe FreeRTOS API\r
+               functions can be called.  ISR safe functions are those that end in\r
+               "FromISR".  FreeRTOS maintains separate thread and ISR API functions to\r
+               ensure interrupt entry is as fast and simple as possible.\r
+\r
+               Save the interrupt priority value that is about to be clobbered. */\r
+               ulOriginalPriority = *pcFirstUserPriorityRegister;\r
+\r
+               /* Write the configMAX_SYSCALL_INTERRUPT_PRIORITY value to an interrupt\r
+               priority register. */\r
+               *pcFirstUserPriorityRegister = configMAX_SYSCALL_INTERRUPT_PRIORITY;\r
+\r
+               /* Read back the written priority to obtain its value as seen by the\r
+               hardware, which will only implement a subset of the priority bits. */\r
+               ucMaxSysCallPriority = *pcFirstUserPriorityRegister;\r
+\r
+               /* Restore the clobbered interrupt priority register to its original\r
+               value. */\r
+               *pcFirstUserPriorityRegister = ulOriginalPriority;\r
+       }\r
+       #endif /* conifgASSERT_DEFINED */\r
+\r
        /* Make PendSV and SysTick the lowest priority interrupts. */\r
        portNVIC_SYSPRI2_REG |= portNVIC_PENDSV_PRI;\r
        portNVIC_SYSPRI2_REG |= portNVIC_SYSTICK_PRI;\r
@@ -523,4 +566,81 @@ __attribute__(( weak )) void vPortSetupTimerInterrupt( void )
        portNVIC_SYSTICK_CTRL_REG = portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT | portNVIC_SYSTICK_ENABLE_BIT;\r
 }\r
 /*-----------------------------------------------------------*/\r
+\r
+#if( configASSERT_DEFINED == 1 )\r
+\r
+       void vPortValidateInterruptPriority( void )\r
+       {\r
+       unsigned long ulCurrentInterrupt;\r
+       unsigned char ucCurrentPriority;\r
+\r
+               /* Obtain the number of the currently executing interrupt. */\r
+               __asm volatile( "mrs %0, ipsr" : "=r"( ulCurrentInterrupt ) );\r
+\r
+               /* Is the interrupt number a user defined interrupt? */\r
+               if( ulCurrentInterrupt >= portFIRST_USER_INTERRUPT_NUMBER )\r
+               {\r
+                       /* Look up the interrupt's priority. */\r
+                       ucCurrentPriority = pcInterruptPriorityRegisters[ ulCurrentInterrupt ];\r
+\r
+                       /* The following assertion will fail if a service routine (ISR) for \r
+                       an interrupt that has been assigned a priority above\r
+                       configMAX_SYSCALL_INTERRUPT_PRIORITY calls an ISR safe FreeRTOS API\r
+                       function.  ISR safe FreeRTOS API functions must *only* be called \r
+                       from interrupts that have been assigned a priority at or below\r
+                       configMAX_SYSCALL_INTERRUPT_PRIORITY.\r
+                       \r
+                       Numerically low interrupt priority numbers represent logically high\r
+                       interrupt priorities, therefore the priority of the interrupt must \r
+                       be set to a value equal to or numerically *higher* than \r
+                       configMAX_SYSCALL_INTERRUPT_PRIORITY.\r
+                       \r
+                       Interrupts that use the FreeRTOS API must not be left at their\r
+                       default priority of     zero as that is the highest possible priority,\r
+                       which is guaranteed to be above configMAX_SYSCALL_INTERRUPT_PRIORITY, \r
+                       and     therefore also guaranteed to be invalid.  \r
+                       \r
+                       FreeRTOS maintains separate thread and ISR API functions to ensure \r
+                       interrupt entry is as fast and simple as possible.\r
+                       \r
+                       The following links provide detailed information:\r
+                       http://www.freertos.org/RTOS-Cortex-M3-M4.html\r
+                       http://www.freertos.org/FAQHelp.html */\r
+                       configASSERT( ucCurrentPriority >= ucMaxSysCallPriority );\r
+               }\r
+\r
+               /* Priority grouping:  The interrupt controller (NVIC) allows the bits \r
+               that define each interrupt's priority to be split between bits that \r
+               define the interrupt's pre-emption priority bits and bits that define\r
+               the interrupt's sub-priority.  For simplicity all bits must be defined \r
+               to be pre-emption priority bits.  The following assertion will fail if\r
+               this is not the case (if some bits represent a sub-priority).  \r
+               \r
+               If CMSIS libraries are being used then the correct setting can be \r
+               achieved by calling     NVIC_SetPriorityGrouping( 0 ); before starting the \r
+               scheduler. */\r
+               configASSERT( ( portAIRCR_REG & portPRIORITY_GROUP_MASK ) == 0 );\r
+       }\r
+\r
+#endif /* configASSERT_DEFINED */\r
+\r
+\r
+\r
+\r
+\r
+\r
+\r
+\r
+\r
+\r
+\r
+\r
+\r
+\r
+\r
+\r
+\r
+\r
+\r
+\r
 \r