// Copyright (c) 1994-2009 Nokia Corporation and/or its subsidiary(-ies).

// All rights reserved.

// This component and the accompanying materials are made available

// under the terms of the License "Eclipse Public License v1.0"

// which accompanies this distribution, and is available

// at the URL "http://www.eclipse.org/legal/epl-v10.html".

//

// Initial Contributors:

// Nokia Corporation - initial contribution.

//

// Contributors:

//

// Description:

// e32\memmodel\epoc\direct\arm\xutils.cpp

// 

//

//#define __DBG_MON_FAULT__

//#define __RAM_LOADED_CODE__

//#define __EARLY_DEBUG__

#include "arm_mem.h"

/**

	@pre	Call in a thread context.

	@pre	Interrupts must be enabled.

	@pre	Kernel must be unlocked.

 */

EXPORT_C TPhysAddr Epoc::LinearToPhysical(TLinAddr aLinAddr)

	{

	CHECK_PRECONDITIONS(MASK_KERNEL_UNLOCKED|MASK_INTERRUPTS_ENABLED|MASK_NOT_ISR|MASK_NOT_IDFC,"Epoc::LinearToPhysical");

	__KTRACE_OPT(KMMU,Kern::Printf("Epoc::LinearToPhysical(%08x)", aLinAddr));

#ifdef __CPU_HAS_MMU

	// Deal with faking no MMU on hardware with an MMU

	if (!Arm::MmuActive())

		return aLinAddr;

	TUint32 phys=0xffffffffu;

	TUint32 pdphys = Arm::MmuTTBR0();

	TUint32 pdlin = TheSuperPage().iPageDir;

	TUint32 offset = pdlin - pdphys;	// offset from phys to lin for page directory/tables

	const TUint32* pageDir = (const TUint32*)pdlin;

	TUint32 pde = pageDir[aLinAddr>>20];

	__KTRACE_OPT(KMMU,Kern::Printf("PDE %08x", pde));

	if ((pde&3)==2)

		{

		// section

		phys = (pde&0xfff00000u) | (aLinAddr&0x000fffffu);

		}

	else if ((pde&3)==1)

		{

		// page table

		TUint32 ptphys = pde & 0xfffffc00u;

		const TUint32* pageTable = (const TUint32*)(ptphys + offset);

		TUint32 pte = pageTable[(aLinAddr>>12)&0xff];

		__KTRACE_OPT(KMMU,Kern::Printf("PTE %08x", pte));

		if ((pte&3)==1)

			{

			// 64K page

			phys = (pte&0xffff0000u) | (aLinAddr&0x0000ffffu);

			}

		else if (pte&3)

			{

			// 4K page

			phys = (pte&0xfffff000u) | (aLinAddr&0x00000fffu);

			}

		else

			{

			FAULT();

			}

		}

	else

		{

		FAULT();

		}

	__KTRACE_OPT(KMMU,Kern::Printf("Physical address = %08x",phys));

	return phys;

#else

	// real non-MMU hardware

	return aLinAddr;

#endif

	}