// 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

 	}