source: rtems/cpukit/include/rtems/score/address.h @ 5803f37

/**
 * @file
 *
 * @ingroup RTEMSScoreAddress
 *
 * @brief Information Required to Manipulate Physical Addresses
 *
 * This include file contains the information required to manipulate
 * physical addresses.
 */

/*
 *  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.org/license/LICENSE.
 */

#ifndef _RTEMS_SCORE_ADDRESS_H
#define _RTEMS_SCORE_ADDRESS_H

#include <rtems/score/cpu.h>

#ifdef __cplusplus
extern "C" {
#endif

/**
 * @defgroup RTEMSScoreAddress Address Handler
 *
 * @ingroup RTEMSScore
 *
 * @brief Support for Address Manipulation
 *
 * This handler encapsulates functionality which abstracts address
 * manipulation in a portable manner.
 *
 * @{
 */

/**
 * @brief Adds offset to an address.
 *
 * This function is used to add an @a offset to a @a base address.
 * It returns the resulting address.  This address is typically
 * converted to an access type before being used further.
 *
 * @param base The base address to add the offset to.
 * @param offset The offset to add to @a base.
 *
 * @return This method returns the resulting address.
 */
RTEMS_INLINE_ROUTINE void *_Addresses_Add_offset (
  const void *base,
  uintptr_t   offset
)
{
  return (void *)((uintptr_t)base + offset);
}

/**
 * @brief Subtracts offset from an address.
 *
 * This function is used to subtract an @a offset from a @a base
 * address.  It returns the resulting address.  This address is
 * typically converted to an access type before being used further.
 *
 * @param base The base address to subtract the offset from.
 * @param offset The offset to subtract from @a base.
 *
 * @return This method returns the resulting address.
 */

RTEMS_INLINE_ROUTINE void *_Addresses_Subtract_offset (
  const void *base,
  uintptr_t   offset
)
{
  return (void *)((uintptr_t)base - offset);
}

/**
 * @brief Subtracts two addresses.
 *
 * This function is used to subtract two addresses.  It returns the
 * resulting offset.
 *
 * @param left The address on the left hand side of the subtraction.
 * @param right The address on the right hand side of the subtraction.
 *
 * @return This method returns the resulting address.
 */
RTEMS_INLINE_ROUTINE intptr_t _Addresses_Subtract(
  const void *left,
  const void *right
)
{
  return (intptr_t) ( (const char *) left - (const char *) right );
}

/**
 * @brief Checks if address is aligned.
 *
 * This function returns true if the given address is correctly
 * aligned for this processor and false otherwise.  Proper alignment
 * is based on correctness and efficiency.
 *
 * @param address The address being checked for alignment.
 *
 * @retval true The @a address is aligned.
 * @retval false The @a address is not aligned.
 */
RTEMS_INLINE_ROUTINE bool _Addresses_Is_aligned(
  const void *address
)
{
  return ( (uintptr_t) address % CPU_ALIGNMENT ) == 0;
}

/**
 * @brief Checks if address is in range.
 *
 * This function returns true if the given address is within the
 * memory range specified and false otherwise.  @a base is the address
 * of the first byte in the memory range and @a limit is the address
 * of the last byte in the memory range.  The base address is
 * assumed to be lower than the limit address.
 *
 * @param address The address to check if it is in the given range.
 * @param base The lowest address of the range to check against.
 * @param limit The highest address of the range to check against.
 *
 * @retval true The @a address is within the memory range specified
 * @retval false The @a address is not within the memory range specified.
 */
RTEMS_INLINE_ROUTINE bool _Addresses_Is_in_range (
  const void *address,
  const void *base,
  const void *limit
)
{
  return (address >= base && address <= limit);
}

/**
 * @brief Aligns address to nearest multiple of alignment, rounding up.
 *
 * This function returns the given address aligned to the given alignment.
 * If the address already is aligned, or if alignment is 0, the address is
 * returned as is. The returned address is greater than or equal to the
 * given address.
 *
 * @param address The address to align to the given alignment.
 * @param alignment The desired alignment for the address. It must be a power of two.
 *
 * @return Returns the aligned address.
 */
RTEMS_INLINE_ROUTINE void *_Addresses_Align_up(
  void *address,
  size_t alignment
)
{
  uintptr_t mask = alignment - (uintptr_t)1;
  return (void*)(((uintptr_t)address + mask) & ~mask);
}

/**
 * @brief Aligns address to nearest multiple of alignment, truncating.
 *
 * This function returns the given address aligned to the given alignment.
 * If the address already is aligned, or if alignment is 0, the address is
 * returned as is. The returned address is less than or equal to the
 * given address.
 *
 * @param address The address to align to the given alignment.
 * @param alignment The desired alignment for the address. It must be a power of two.
 *
 * @return Returns the aligned address.
 */
RTEMS_INLINE_ROUTINE void *_Addresses_Align_down(
  void *address,
  size_t alignment
)
{
  uintptr_t mask = alignment - (uintptr_t)1;
  return (void*)((uintptr_t)address & ~mask);
}

/** @} */

#ifdef __cplusplus
}
#endif

#endif
/* end of include file */