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

*                                                                             *

* License Agreement                                                           *

*                                                                             *

* Copyright (c) 2007 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" 

/*

 * The INITDA instruction was added to Nios II in the 8.0 release.

 *

 * The INITDA instruction has one of the following possible behaviors

 * depending on the processor configuration:

 *  1) Flushes a line by address but does NOT write back dirty data.

 *     Occurs when a data cache is present that supports INITDA.

 *     The macro NIOS2_INITDA_SUPPORTED is defined in system.h.

 *  2) Takes an unimplemented instruction exception.

 *     Occurs when a data cache is present that doesn't support INITDA.

 *  3) Performs no operation

 *     Occurs when there is no data cache present.

 *     The macro NIOS2_DCACHE_SIZE is 0 in system.h.

 */

#define ALT_FLUSH_DATA_NO_WRITEBACK(i) \

  __asm__ volatile ("initda (%0)" :: "r" (i));

/*

 * alt_dcache_flush_no_writeback() 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 NOT written back to memory.

 * Make sure you really want this behavior.  If you aren't 100% sure,

 * use the alt_dcache_flush() routine instead.

 */

void alt_dcache_flush_no_writeback (void* start, alt_u32 len)

{

#if defined(NIOS2_INITDA_SUPPORTED)

  char* i;

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

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

  {

    ALT_FLUSH_DATA_NO_WRITEBACK(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_NO_WRITEBACK(i);

  }

#endif /* NIOS2_INITDA_SUPPORTED */

}