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/**
* @file rtems/score/isr.h
*
* 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) 1989-2006.
* 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.
*
* $Id$
*/
#ifndef _RTEMS_SCORE_ISR_H
#define _RTEMS_SCORE_ISR_H
#include <rtems/score/percpu.h>
/**
* @defgroup ScoreISR ISR Handler
*
* 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 control block used to manage
* the interrupt level portion of the status register.
*/
typedef uint32_t ISR_Level;
/**
* 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;
/**
* 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
#if (CPU_SIMPLE_VECTORED_INTERRUPTS == TRUE)
/**
* 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
/**
* This routine performs the initialization necessary for this handler.
*/
void _ISR_Handler_initialization ( void );
/**
* This routine disables all interrupts so that a critical section
* of code can be executing without being interrupted. Upon return,
* the argument _level will contain the previous interrupt mask level.
*/
#define _ISR_Disable( _level ) \
do { \
_CPU_ISR_Disable( _level ); \
RTEMS_COMPILER_MEMORY_BARRIER(); \
} while (0)
/**
* This routine enables interrupts to the previous interrupt mask
* LEVEL. It is used at the end of a critical section of code to
* enable interrupts so they can be processed again.
*/
#define _ISR_Enable( _level ) \
do { \
RTEMS_COMPILER_MEMORY_BARRIER(); \
_CPU_ISR_Enable( _level ); \
} while (0)
/**
* This routine temporarily enables interrupts to the previous
* interrupt mask level and then disables all interrupts so that
* the caller can continue into the second part of a critical
* section. This routine is used to temporarily enable interrupts
* during a long critical section. It is used in long sections of
* critical code when a point is reached at which interrupts can
* be temporarily enabled. Deciding where to flash interrupts
* in a long critical section is often difficult and the point
* must be selected with care to ensure that the critical section
* properly protects itself.
*/
#define _ISR_Flash( _level ) \
do { \
RTEMS_COMPILER_MEMORY_BARRIER(); \
_CPU_ISR_Flash( _level ); \
RTEMS_COMPILER_MEMORY_BARRIER(); \
} while (0)
/**
* This routine installs new_handler as the interrupt service routine
* for the specified vector. The previous interrupt service routine is
* returned as old_handler.
*/
#define _ISR_Install_vector( _vector, _new_handler, _old_handler ) \
_CPU_ISR_install_vector( _vector, _new_handler, _old_handler )
/**
* This routine returns the current interrupt level.
*/
#define _ISR_Get_level() \
_CPU_ISR_Get_level()
/**
* This routine sets the current interrupt level to that specified
* by new_level. The new interrupt level is effective when the
* routine exits.
*/
#define _ISR_Set_level( _new_level ) \
do { \
RTEMS_COMPILER_MEMORY_BARRIER(); \
_CPU_ISR_Set_level( _new_level ); \
RTEMS_COMPILER_MEMORY_BARRIER(); \
} while (0)
/**
* 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 Implemented in assembly language.
*/
void _ISR_Handler( void );
/**
* 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 Implemented in assembly language.
*/
void _ISR_Dispatch( void );
/**
* 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. The
*/
#if (CPU_PROVIDES_ISR_IS_IN_PROGRESS == TRUE)
bool _ISR_Is_in_progress( void );
#else
#define _ISR_Is_in_progress() \
(_ISR_Nest_level != 0)
#endif
#include <rtems/score/isr.inl>
#ifdef __cplusplus
}
#endif
/**@}*/
#endif
/* end of include file */
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