xil_mmu.c

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/*****************************************************************************/
/**
* @file xil_mmu.c
*
* This file provides APIs for enabling/disabling MMU and setting the memory
* attributes for sections, in the MMU translation table.
*
* <pre>
* MODIFICATION HISTORY:
*
* Ver   Who  Date     Changes
* ----- ---- -------- ---------------------------------------------------
* 1.00a sdm  01/12/12 Initial version
* 3.05a asa  03/10/12 Modified the Xil_EnableMMU to invalidate the caches
*		      before enabling back.
* 3.05a asa  04/15/12 Modified the Xil_SetTlbAttributes routine so that
*		      translation table and branch predictor arrays are
*		      invalidated, D-cache flushed before the attribute
*		      change is applied. This is done so that the user
*		      need not call Xil_DisableMMU before calling
*		      Xil_SetTlbAttributes.
* </pre>
*
* @note
*
* None.
*
******************************************************************************/

/***************************** Include Files *********************************/

#include "xil_cache.h"
#include "xpseudo_asm.h"
#include "xil_types.h"

/***************** Macros (Inline Functions) Definitions *********************/

/**************************** Type Definitions *******************************/

/************************** Constant Definitions *****************************/

/************************** Variable Definitions *****************************/

extern u32 MMUTable;

/************************** Function Prototypes ******************************/

/*****************************************************************************
*
* Set the memory attributes for a section, in the translation table. Each
* section covers 1MB of memory.
*
* @param	addr is the address for which attributes are to be set.
* @param	attrib specifies the attributes for that memory region.
*
* @return	None.
*
* @note		The MMU and D-cache need not be disabled before changing an
*		translation table attribute.
*
******************************************************************************/
void Xil_SetTlbAttributes(u32 addr, u32 attrib)
{
	u32 *ptr;
	u32 section;

	mtcp(XREG_CP15_INVAL_UTLB_UNLOCKED, 0);
	dsb();

	section = addr / 0x100000;
	ptr = &MMUTable + section;
	*ptr = (addr & 0xFFF00000) | attrib;
	dsb();

	mtcp(XREG_CP15_INVAL_UTLB_UNLOCKED, 0);
	/* Invalidate all branch predictors */
	mtcp(XREG_CP15_INVAL_BRANCH_ARRAY, 0);

	dsb(); /* ensure completion of the BP and TLB invalidation */
    isb(); /* synchronize context on this processor */
}

/*****************************************************************************
*
* Invalidate the caches, enable MMU and D Caches for Cortex A9 processor.
*
* @param	None.
* @return	None.
*
******************************************************************************/
void Xil_EnableMMU(void)
{
	u32 Reg;
	Xil_DCacheInvalidate();
	Xil_ICacheInvalidate();

#ifdef __GNUC__
	Reg = mfcp(XREG_CP15_SYS_CONTROL);
#else
	{ volatile register unsigned int Cp15Reg __asm(XREG_CP15_SYS_CONTROL);
	  Reg = Cp15Reg; }
#endif
	Reg |= 0x05;
	mtcp(XREG_CP15_SYS_CONTROL, Reg);

	dsb();
	isb();
}

/*****************************************************************************
*
* Disable MMU for Cortex A9 processors. This function invalidates the TLBs,
* Branch Predictor Array and flushed the D Caches before disabling
* the MMU and D cache.
*
* @param	None.
*
* @return	None.
*
******************************************************************************/
void Xil_DisableMMU(void)
{
	u32 Reg;

	mtcp(XREG_CP15_INVAL_UTLB_UNLOCKED, 0);
	mtcp(XREG_CP15_INVAL_BRANCH_ARRAY, 0);
	Xil_DCacheFlush();

#ifdef __GNUC__
	Reg = mfcp(XREG_CP15_SYS_CONTROL);
#else
	{ volatile register unsigned int Cp15Reg __asm(XREG_CP15_SYS_CONTROL);
	  Reg = Cp15Reg; }
#endif
	Reg &= ~0x05;
	mtcp(XREG_CP15_SYS_CONTROL, Reg);
}