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/**
* @file rtems/score/isr.h
*
* @brief Data Related to the Management of Processor Interrupt Levels
*
* This include file contains all the constants and structures associated
* with the management of processor interrupt levels. This handler
* supports interrupt critical sections, vectoring of user interrupt
* handlers, nesting of interrupts, and manipulating interrupt levels.
*/
/*
* COPYRIGHT (c) 1989-2012.
* On-Line Applications Research Corporation (OAR).
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.com/license/LICENSE.
*/
#ifndef _RTEMS_SCORE_ISR_H
#define _RTEMS_SCORE_ISR_H
#include <rtems/score/isrlevel.h>
#include <rtems/score/percpu.h>
/**
* @defgroup ScoreISR ISR Handler
*
* @ingroup Score
*
* This handler encapsulates functionality which provides the foundation
* ISR services used in all of the APIs supported by RTEMS.
*
* The ISR Nest level counter variable is maintained as part of the
* per cpu data structure.
*/
/**@{*/
#ifdef __cplusplus
extern "C" {
#endif
/**
* The following type defines the type used to manage the vectors.
*/
typedef uint32_t ISR_Vector_number;
/**
* Return type for ISR Handler
*/
typedef void ISR_Handler;
#if (CPU_SIMPLE_VECTORED_INTERRUPTS == FALSE)
typedef void * ISR_Handler_entry;
#else
/**
* Pointer to an ISR Handler
*/
#if (CPU_ISR_PASSES_FRAME_POINTER == 1)
typedef ISR_Handler ( *ISR_Handler_entry )(
ISR_Vector_number,
CPU_Interrupt_frame *
);
#else
typedef ISR_Handler ( *ISR_Handler_entry )(
ISR_Vector_number
);
#endif
/**
* This constant promotes out the number of vectors truly supported by
* the current CPU being used. This is usually the number of distinct vectors
* the cpu can vector.
*/
#define ISR_NUMBER_OF_VECTORS CPU_INTERRUPT_NUMBER_OF_VECTORS
/**
* This constant promotes out the highest valid interrupt vector number.
*/
#define ISR_INTERRUPT_MAXIMUM_VECTOR_NUMBER CPU_INTERRUPT_MAXIMUM_VECTOR_NUMBER
/**
* The following declares the Vector Table. Application
* interrupt service routines are vectored by the ISR Handler via this table.
*/
SCORE_EXTERN ISR_Handler_entry *_ISR_Vector_table;
#endif
/**
* @brief Initialize the ISR handler.
*
* This routine performs the initialization necessary for the ISR handler.
*/
void _ISR_Handler_initialization ( void );
#if defined( RTEMS_SMP )
/**
* @brief Initialize SMP interrupt critical section support.
*
* This method initializes the variables required by the SMP implementation
* of interrupt critical section management.
*/
void _ISR_SMP_Initialize(void);
/**
* @brief Enter SMP interrupt code.
*
* This method is used to enter the SMP interrupt section.
*
* @retval This method returns the isr level.
*/
int _ISR_SMP_Enter(void);
/**
* @brief Exit SMP interrupt code.
*
* This method is used to exit the SMP interrupt.
*
* @retval This method returns 0 on a simple return and returns 1 on a
* dispatching return.
*/
int _ISR_SMP_Exit(void);
#endif /* defined( RTEMS_SMP ) */
/**
* @brief Install interrupt handler vector.
*
* This routine installs new_handler as the interrupt service routine
* for the specified vector. The previous interrupt service routine is
* returned as old_handler.
*
* LM32 Specific Information:
* XXX document implementation including references if appropriate
*
* @param[in] _vector is the vector number
* @param[in] _new_handler is ISR handler to install
* @param[in] _old_handler is a pointer to a variable which will be set
* to the old handler
*
* @retval *_old_handler will be set to the old ISR handler
*/
#define _ISR_Install_vector( _vector, _new_handler, _old_handler ) \
_CPU_ISR_install_vector( _vector, _new_handler, _old_handler )
/**
* @brief ISR interrupt dispatcher.
*
* This routine is the interrupt dispatcher. ALL interrupts
* are vectored to this routine so that minimal context can be saved
* and setup performed before the application's high-level language
* interrupt service routine is invoked. After the application's
* interrupt service routine returns control to this routine, it
* will determine if a thread dispatch is necessary. If so, it will
* ensure that the necessary thread scheduling operations are
* performed when the outermost interrupt service routine exits.
*
* @note Typically implemented in assembly language.
*/
void _ISR_Handler( void );
/**
* @brief ISR wrapper for thread dispatcher.
*
* This routine provides a wrapper so that the routine
* @ref _Thread_Dispatch can be invoked when a reschedule is necessary
* at the end of the outermost interrupt service routine. This
* wrapper is necessary to establish the processor context needed
* by _Thread_Dispatch and to save the processor context which is
* corrupted by _Thread_Dispatch. This context typically consists
* of registers which are not preserved across routine invocations.
*
* @note Typically mplemented in assembly language.
*/
void _ISR_Dispatch( void );
/**
* @brief Returns the current ISR nest level
*
* This function can be called in any context. On SMP configurations
* interrupts are disabled to ensure that the processor index is used
* consistently.
*
* @return The current ISR nest level.
*/
RTEMS_INLINE_ROUTINE uint32_t _ISR_Get_nest_level( void )
{
uint32_t isr_nest_level;
#if defined( RTEMS_SMP )
ISR_Level level;
_ISR_Disable( level );
#endif
isr_nest_level = _ISR_Nest_level;
#if defined( RTEMS_SMP )
_ISR_Enable( level );
#endif
return isr_nest_level;
}
/**
* @brief Checks if an ISR in progress.
*
* This function returns true if the processor is currently servicing
* and interrupt and false otherwise. A return value of true indicates
* that the caller is an interrupt service routine, NOT a thread.
*
* @retval This methods returns true when called from an ISR.
*/
#if (CPU_PROVIDES_ISR_IS_IN_PROGRESS == TRUE)
bool _ISR_Is_in_progress( void );
#else
#define _ISR_Is_in_progress() \
(_ISR_Get_nest_level() != 0)
#endif
#ifdef __cplusplus
}
#endif
/**@}*/
#endif
/* end of include file */
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