/** * @file * * @ingroup RTEMSScorePriority * * @brief Inlined Routines in the Priority Handler Bit Map Implementation * * This file contains the static inline implementation of all inlined * routines in the Priority Handler bit map implementation */ /* * COPYRIGHT (c) 1989-2010. * 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.org/license/LICENSE. */ #ifndef _RTEMS_SCORE_PRIORITYBITMAPIMPL_H #define _RTEMS_SCORE_PRIORITYBITMAPIMPL_H #include #include #ifdef __cplusplus extern "C" { #endif /** * @addtogroup RTEMSScorePriority * * @{ */ /** * This table is used by the generic bitfield routines to perform * a highly optimized bit scan without the use of special CPU * instructions. */ extern const unsigned char _Bitfield_Leading_zeros[256]; /** * @brief Returns the bit number of the first bit set in the specified value. * * The correspondence between the bit number and actual bit position is CPU * architecture dependent. The search for the first bit set may run from most * to least significant bit or vice-versa. * * @param value The value to bit scan. * * @return The bit number of the first bit set. * * @see _Priority_Bits_index() and _Priority_Mask(). */ RTEMS_INLINE_ROUTINE unsigned int _Bitfield_Find_first_bit( unsigned int value ) { unsigned int bit_number; #if ( CPU_USE_GENERIC_BITFIELD_CODE == FALSE ) _CPU_Bitfield_Find_first_bit( value, bit_number ); #elif defined(__GNUC__) bit_number = (unsigned int) __builtin_clz( value ) - __SIZEOF_INT__ * __CHAR_BIT__ + 16; #else if ( value < 0x100 ) { bit_number = _Bitfield_Leading_zeros[ value ] + 8; } else { \ bit_number = _Bitfield_Leading_zeros[ value >> 8 ]; } #endif return bit_number; } /** * @brief Returns the priority bit mask for the specified major or minor bit * number. * * @param bit_number The bit number for which we need a mask. * * @return The priority bit mask. */ RTEMS_INLINE_ROUTINE Priority_bit_map_Word _Priority_Mask( unsigned int bit_number ) { #if ( CPU_USE_GENERIC_BITFIELD_CODE == FALSE ) return _CPU_Priority_Mask( bit_number ); #else return (Priority_bit_map_Word) ( 0x8000u >> bit_number ); #endif } /** * @brief Returns the bit index position for the specified major or minor bit * number. * * @param bit_number The bit number for which we need an index. * * @return The corresponding array index into the priority bit map. */ RTEMS_INLINE_ROUTINE unsigned int _Priority_Bits_index( unsigned int bit_number ) { #if ( CPU_USE_GENERIC_BITFIELD_CODE == FALSE ) return _CPU_Priority_bits_index( bit_number ); #else return bit_number; #endif } /** * @brief Returns the major portion of the_priority. * * @param the_priority The priority of which we want the major portion. * * @return The major portion of the priority. */ RTEMS_INLINE_ROUTINE unsigned int _Priority_Major( unsigned int the_priority ) { return the_priority / 16; } /** * @brief Returns the minor portion of the_priority. * * @param the_priority The priority of which we want the minor portion. * * @return The minor portion of the priority. */ RTEMS_INLINE_ROUTINE unsigned int _Priority_Minor( unsigned int the_priority ) { return the_priority % 16; } /** * @brief Initializes a bit map. * * @param[out] bit_map The bit map to initialize. */ RTEMS_INLINE_ROUTINE void _Priority_bit_map_Initialize( Priority_bit_map_Control *bit_map ) { memset( bit_map, 0, sizeof( *bit_map ) ); } /** * @brief Adds Priority queue bit map information. * * Priority Queue implemented by bit map. * * @param[out] bit_map The bit map to be altered by @a bit_map_info. * @param bit_map_info The information with which to alter @a bit_map. */ RTEMS_INLINE_ROUTINE void _Priority_bit_map_Add ( Priority_bit_map_Control *bit_map, Priority_bit_map_Information *bit_map_info ) { *bit_map_info->minor |= bit_map_info->ready_minor; bit_map->major_bit_map |= bit_map_info->ready_major; } /** * @brief Removes Priority queue bit map information. * * Priority Queue implemented by bit map. * * @param[out] bit_map The bit map to be altered by @a bit_map_info. * @param bit_map_info The information with which to alter @a bit_map. */ RTEMS_INLINE_ROUTINE void _Priority_bit_map_Remove ( Priority_bit_map_Control *bit_map, Priority_bit_map_Information *bit_map_info ) { *bit_map_info->minor &= bit_map_info->block_minor; if ( *bit_map_info->minor == 0 ) bit_map->major_bit_map &= bit_map_info->block_major; } /** * @brief Gets highest portion of Priority queue bit map. * * @param bit_map The bitmap to get the highest portion from. * * @return The highest portion of the bitmap. */ RTEMS_INLINE_ROUTINE unsigned int _Priority_bit_map_Get_highest( const Priority_bit_map_Control *bit_map ) { unsigned int minor; unsigned int major; major = _Bitfield_Find_first_bit( bit_map->major_bit_map ); minor = _Bitfield_Find_first_bit( bit_map->bit_map[ major ] ); return (_Priority_Bits_index( major ) << 4) + _Priority_Bits_index( minor ); } /** * @brief Checks if the Priority queue bit map is empty. * * @param bit_map The bit map of which to check if it is empty. * * @retval true The Priority queue bit map is empty * @retval false The Priority queue bit map is not empty. */ RTEMS_INLINE_ROUTINE bool _Priority_bit_map_Is_empty( const Priority_bit_map_Control *bit_map ) { return bit_map->major_bit_map == 0; } /** * @brief Initializes the bit map information. * * @param bit_map The bit map for the initialization of the bit * map information. * @param[out] bit_map_info The bit map information to initialize. * @param new_priority The new priority for the initialization * of the bit map information. */ RTEMS_INLINE_ROUTINE void _Priority_bit_map_Initialize_information( Priority_bit_map_Control *bit_map, Priority_bit_map_Information *bit_map_info, unsigned int new_priority ) { unsigned int major; unsigned int minor; Priority_bit_map_Word mask; major = _Priority_Major( new_priority ); minor = _Priority_Minor( new_priority ); bit_map_info->minor = &bit_map->bit_map[ _Priority_Bits_index( major ) ]; mask = _Priority_Mask( major ); bit_map_info->ready_major = mask; bit_map_info->block_major = (Priority_bit_map_Word) ~mask; mask = _Priority_Mask( minor ); bit_map_info->ready_minor = mask; bit_map_info->block_minor = (Priority_bit_map_Word) ~mask; } /** @} */ #ifdef __cplusplus } #endif #endif /* end of include file */