xcache_l.c

基于Xilinx-XUPV2P开发平台的嵌入式系统实验例程：实验4编写基本的应用程序

/*-----------------------------------------------------------------------------
//     $Date: 2004/12/29 18:12:50 $
//     $RCSfile: xcache_l.c,v $
//-----------------------------------------------------------------------------
//
// Copyright (c) 2004 Xilinx, Inc.  All rights reserved. 
// 
// Xilinx, Inc. 
// XILINX IS PROVIDING THIS DESIGN, CODE, OR INFORMATION "AS IS" AS A 
// COURTESY TO YOU.  BY PROVIDING THIS DESIGN, CODE, OR INFORMATION AS 
// ONE POSSIBLE   IMPLEMENTATION OF THIS FEATURE, APPLICATION OR 
// STANDARD, XILINX IS MAKING NO REPRESENTATION THAT THIS IMPLEMENTATION 
// IS FREE FROM ANY CLAIMS OF INFRINGEMENT, AND YOU ARE RESPONSIBLE 
// FOR OBTAINING ANY RIGHTS YOU MAY REQUIRE FOR YOUR IMPLEMENTATION. 
// XILINX EXPRESSLY DISCLAIMS ANY WARRANTY WHATSOEVER WITH RESPECT TO 
// THE ADEQUACY OF THE IMPLEMENTATION, INCLUDING BUT NOT LIMITED TO 
// ANY WARRANTIES OR REPRESENTATIONS THAT THIS IMPLEMENTATION IS FREE 
// FROM CLAIMS OF INFRINGEMENT, IMPLIED WARRANTIES OF MERCHANTABILITY 
// AND FITNESS FOR A PARTICULAR PURPOSE.
//
//---------------------------------------------------------------------------*/

#include "xcache_l.h"
#include "xpseudo_asm.h"

#define DCWR_VAL        0x0
#define SGR_VAL         0x0
/* #define SU0R_VAL        0x0 */
/* #define SLER_VAL        0x0 */
#define CCR0_VAL        0x700a00

#define DCACHE_SIZE     (16*1024)

/****************************************************************************
*
* Write to the Core-Configuration Register (CCR0)
*
* @param    Value to be written to CCR0.  The bit fields are defined 
*           in xreg405.h
*
* @return   None.
*
* @note     
*
* None.
*
****************************************************************************/

/* special registers */
void XCache_WriteCCR0(unsigned int val)
{
  sync;
  isync;
  mtspr(XREG_SPR_CCR0, val);
  sync;
  isync;
}


/****************************************************************************
*
* Enable the data cache. 
*
* @param    Memory regions to be marked as cachable.  Each bit in the regions
*           variable stands for 128MB of memory.
*           regions    --> cached address range
*           ------------|--------------------------------------------------
*           0x80000000  | [0, 0x7FFFFFF]
*           0x00000001  | [0xF8000000, 0xFFFFFFFF]
*           0x80000001  | [0, 0x7FFFFFF],[0xF8000000, 0xFFFFFFFF]
*    
* @return   None.
*
* @note     
*
* Processor must be in real mode.
*
****************************************************************************/

void XCache_EnableDCache(unsigned int regions)
{
  XCache_DisableDCache();
  /* after this point cache is disabled and invalidated */
  
  mtspr(XREG_SPR_SGR,  SGR_VAL);
  /* mtspr(XREG_SPR_SLER, SLER_VAL); */
  /* mtspr(XREG_SPR_SU0R, SU0R_VAL); */
  mtspr(XREG_SPR_DCWR, DCWR_VAL); 
  mtspr(XREG_SPR_DCCR, regions);
  isync;
}

/****************************************************************************
*
* Disable the data cache. 
*
* @param    None
*    
* @return   None.
*
* @note     
*
* Processor must be in real mode.
*
****************************************************************************/
void XCache_DisableDCache(void)
{
  register unsigned int address0;
  register unsigned int ccr0;
  register unsigned int tag;
  register unsigned int i;
  unsigned int dccr;
  
  dccr = mfspr(XREG_SPR_DCCR);
  if (dccr != 0)
  { /* dcache is enabled; read tags and flush valid and dirty lines */
    ccr0 = mfspr(XREG_SPR_CCR0);                /* read CCR0 */
    ccr0 = (ccr0 & 0xfffffffe) | 0x10;  /* read tags from A way */
    i = 0;
    while (i < 2)
    {
      mtspr(XREG_SPR_CCR0, ccr0);
      address0 = 0x0;
      while (address0 < (DCACHE_SIZE / 2))
      {
        tag = dcread(address0);
        if ((tag & 0x30) == 0x30)       /* valid and dirty? */
          dcbf((tag & 0xfffff000) | address0);
        address0 += 32;
      }
      ccr0 |= 1;                        /* read tags from B way */
      i++;
    }
    sync;
    mtspr(XREG_SPR_DCCR, 0);
    isync;
  }
  else
  {  /* dcache is not enabled; invalidate all lines */
    address0 = 0;
    while (address0 < (DCACHE_SIZE/2))
    {
      dccci(address0);
      address0 += 32;
    }
  }
}

/****************************************************************************
*
* Flush a data cache line. If the byte specified by the address (adr) 
* is cached by the data cache, the cacheline containing that byte is 
* invalidated.  If the cacheline is modified (dirty), the entire 
* contents of the cacheline are written to system memory before the 
* line is invalidated.
*
* @param    Address to be flushed
*    
* @return   None.
*
* @note     
*
* Processor must be in real mode.
*
****************************************************************************/

void XCache_FlushDCacheLine(unsigned int adr)
{
  dcbf(adr);
  sync;
  isync;
}

/****************************************************************************
*
* Invalidate a data cache line. If the byte specified by the address (adr) 
* is cached by the data cache, the cacheline containing that byte is 
* invalidated.  If the cacheline is modified (dirty), the modified contents  
* are lost and are NOT written to system memory before the line is 
* invalidated.
*
* @param    Address to be flushed
*    
* @return   None.
*
* @note     
*
* Processor must be in real mode.
*
****************************************************************************/

void XCache_InvalidateDCacheLine(unsigned int adr)
{
  dcbi(adr);
  sync;
  isync;
}

/****************************************************************************
*
* Store a data cache line. If the byte specified by the address (adr) 
* is cached by the data cache and the cacheline is modified (dirty), 
* the entire contents of the cacheline are written to system memory.  
* After the store completes, the cacheline is marked as unmodified 
* (not dirty).
*
* @param    Address to be stored
*    
* @return   None.
*
* @note     
*
* Processor must be in real mode.
*
****************************************************************************/

void XCache_StoreDCacheLine(unsigned int adr)
{
  dcbst(adr);
  sync;
  isync;
}

/****************************************************************************
*
* Enable the instruction cache. 
*
* @param    Memory regions to be marked as cachable.  Each bit in the regions
*           variable stands for 128MB of memory.
*           regions    --> cached address range
*           ------------|--------------------------------------------------
*           0x80000000  | [0, 0x7FFFFFF]
*           0x00000001  | [0xF8000000, 0xFFFFFFFF]
*           0x80000001  | [0, 0x7FFFFFF],[0xF8000000, 0xFFFFFFFF]
*    
* @return   None.
*
* @note     
*
* Processor must be in real mode.
*
****************************************************************************/

void XCache_EnableICache(unsigned int regions)
{
  XCache_DisableICache();
  
  mtspr(XREG_SPR_SGR, SGR_VAL);
  /* mtspr(XREG_SPR_SLER, SLER_VAL); */
  /* mtspr(XREG_SPR_SU0R, SU0R_VAL); */
  iccci;
  mtspr(XREG_SPR_ICCR, regions);
  isync;
}

/****************************************************************************
*
* Disable the instruction cache. 
*
* @param    None
*    
* @return   None.
*
* @note     
*
* Processor must be in real mode.
*
****************************************************************************/

void XCache_DisableICache(void)
{
  iccci;
  mtspr(XREG_SPR_ICCR, 0);
  isync;
}

/****************************************************************************
*
* Invalidate the entire instruction cache. 
*
* @param    None
*    
* @return   None.
*
* @note     
*
* Processor must be in real mode.
*
****************************************************************************/

void XCache_InvalidateICache(void)
{
  iccci;
  isync;
}

/****************************************************************************
*
* Invalidate an instruction cache line.  If the instruction specified by the
* parameter adr is cached by the instruction cache, the cacheline containing
* that instruction is invalidated.
*
* @param    None
*    
* @return   None.
*
* @note     
*
* Processor must be in real mode.
*
****************************************************************************/

void XCache_InvalidateICacheLine(unsigned int adr)
{
  icbi(adr);
  isync;
}