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/******************************************************************************

*                                                                             *

* License Agreement                                                           *

*                                                                             *

* Copyright (c) 2003-2005 Altera Corporation, San Jose, California, USA.      *

* All rights reserved.                                                        *

*                                                                             *

* Permission is hereby granted, free of charge, to any person obtaining a     *

* copy of this software and associated documentation files (the "Software"),  *

* to deal in the Software without restriction, including without limitation   *

* the rights to use, copy, modify, merge, publish, distribute, sublicense,    *

* and/or sell copies of the Software, and to permit persons to whom the       *

* Software is furnished to do so, subject to the following conditions:        *

*                                                                             *

* The above copyright notice and this permission notice shall be included in  *

* all copies or substantial portions of the Software.                         *

*                                                                             *

* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR  *

* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,    *

* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE *

* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER      *

* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING     *

* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER         *

* DEALINGS IN THE SOFTWARE.                                                   *

*                                                                             *

* This agreement shall be governed in all respects by the laws of the State   *

* of California and by the laws of the United States of America.              *

*                                                                             *

******************************************************************************/

#include "nios2.h"

#include "system.h"

#include "alt_types.h"

#include "sys/alt_cache.h" 

/*

 * Nios II version 1.2 and newer supports the "flush by address" instruction, in

 * addition to the "flush by line" instruction provided by older versions of

 * the core. This newer instruction is used by preference when it is

 * available.

 */

#ifdef NIOS2_FLUSHDA_SUPPORTED

#define ALT_FLUSH_DATA(i) __asm__ volatile ("flushda (%0)" :: "r" (i));

#else

#define ALT_FLUSH_DATA(i) __asm__ volatile ("flushd (%0)" :: "r" (i));

#endif /* NIOS2_FLUSHDA_SUPPORTED */

/*

 * alt_dcache_flush() is called to flush the data cache for a memory

 * region of length "len" bytes, starting at address "start".

 *

 * Any dirty lines in the data cache are written back to memory.

 */

void alt_dcache_flush (void* start, alt_u32 len)

{

#if NIOS2_DCACHE_SIZE > 0

  char* i;

  char* end;

  /*

   * This is the most we would ever need to flush.

   *

   * SPR 196942, 2006.01.13: The cache flush loop below will use the

   * 'flushda' instruction if its available; in that case each line

   * must be flushed individually, and thus 'len' cannot be trimmed.

   */

  #ifndef NIOS2_FLUSHDA_SUPPORTED

  if (len > NIOS2_DCACHE_SIZE)

  {

    len = NIOS2_DCACHE_SIZE;

  }

  #endif

  end = ((char*) start) + len;

  for (i = start; i < end; i+= NIOS2_DCACHE_LINE_SIZE)

  {

    ALT_FLUSH_DATA(i);

  }

  /*

   * For an unaligned flush request, we've got one more line left.

   * Note that this is dependent on NIOS2_DCACHE_LINE_SIZE to be a

   * multiple of 2 (which it always is).

   */

  if (((alt_u32) start) & (NIOS2_DCACHE_LINE_SIZE - 1))

  {

    ALT_FLUSH_DATA(i);

  }

#endif /* NIOS2_DCACHE_SIZE > 0 */

}