// Copyright (c) 2007-2009 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:

//

#include <plat_priv.h>

#include "mm.h"

#include "mmu.h"

#include "mmappinglist.h"

#include "mmapping.h"

TSpinLock TMappingListBase::iSpinLock(TSpinLock::EOrderGenericIrqHigh3);

//

// TMappingList

//

void TMappingList::Add(DMemoryMappingBase* aMapping)

	{

	__NK_ASSERT_DEBUG(LockIsHeld());

	aMapping->iLink.InsertBefore(this);

	}

void TMappingList::Remove(DMemoryMappingBase* aMapping)

	{

	__NK_ASSERT_DEBUG(LockIsHeld());

	aMapping->iLink.Remove();

	}

// Utility methods

void TMappingList::RemapPage(TPhysAddr& aPageArray, TUint aIndex, TBool aInvalidateTLB)

	{

	Lock();

	TMappingListIter iter;

	DMemoryMappingBase* mapping = iter.Start(*this);

	while(mapping)

		{		

		TUint start = aIndex-mapping->iStartIndex;

		if(start < mapping->iSizeInPages && !mapping->IsPinned())

			{

			// remap the page in the mapping...

			mapping->Open();

			TUint mapInstanceCount = mapping->MapInstanceCount();

			Unlock();

			mapping->RemapPage(aPageArray, aIndex, mapInstanceCount, aInvalidateTLB);

			mapping->AsyncClose();

			}

		else

			{

			// the mapping doesn't contain the page or is a pinned mapping and therefore doesn't own

			// any page tables...

			Unlock();

			}

		Lock();

		mapping = iter.Next();

		}

	iter.Finish();

	Unlock();

	}

//

// TMappingListIter

//

DMemoryMappingBase* TMappingListIter::Start(TMappingList& aList)

	{

	TRACE2(("TMappingListIter::Start"));

	__NK_ASSERT_DEBUG(LockIsHeld());

	return Next(&aList);

	}

void TMappingListIter::Finish()

	{

	TRACE2(("TMappingListIter::Finish"));

	__NK_ASSERT_DEBUG(LockIsHeld());

	Remove();

	}

DMemoryMappingBase* TMappingListIter::Next(TMappingListBase* aPrev)

	{

	// avoid live-lock by only flashing iSpinLock after a number of attempts greater

	// than the number of CPU cores, that way each core is guaranteed to make some headway...

	const TUint KFlashPeriod = KMaxCpus+1;

	__ASSERT_COMPILE(KFlashPeriod<10); // make sure limit is sensible, if not, will need more complex live-lock avoidance

	TUint flash = 0;

	TMappingListBase* prev = aPrev;

	TMappingListBase* next = prev->iNext;

	for(;;)

		{

		TUint type = next->iType;

		// at end of list?

		if(type==EHead)

			{

			// yes, so put iterator back at end...

			prev->iNext = this;

			next->iPrev = this;

			iNext = next;

			iPrev = prev;

			// return NULL...

			TRACE2(("TMappingListIter::Next returns 0"));

			return 0;

			}

		// move past next...

		prev = next;

		next = next->iNext;

		// have we found a mapping?

		if(type==ELink)

			{

			// yes, so insert iterator after it...

			prev->iNext = this;

			next->iPrev = this;

			iNext = next;

			iPrev = prev;

			// return mapping...

			DMemoryMappingBase* mapping = (DMemoryMappingBase*)((TLinAddr)prev-_FOFF(DMemoryMappingBase,iLink));

			TRACE2(("TMappingListIter::Next returns 0x%08x",mapping));

			return mapping;

			}

		// move on to next...

		TRACE2(("TMappingListIter::Next skip %d",next->iType));

		// but first see if we need to flash lock...

		if(++flash>=KFlashPeriod)

			{

			// we need to flash the lock, but first put iterator back in list so we don't loose our place...

			prev->iNext = this;

			next->iPrev = this;

			iNext = next;

			iPrev = prev;

			// flash lock...

			__SPIN_FLASH_IRQ(iSpinLock);

			// remove iterator again...

			next = iNext;

			prev = iPrev;

			prev->iNext = next;

			next->iPrev = prev;

			}

		// loop back and try next

		}

	}

DMemoryMappingBase* TMappingListIter::Next()

	{

	__NK_ASSERT_DEBUG(LockIsHeld());

	TMappingListBase* next = iNext;

	TMappingListBase* prev = iPrev;

	TUint type = next->iType;

	// at end of list?

	if(type==EHead)

		{

		// yes, return NULL...

		TRACE2(("TMappingListIter::Next returns 0"));

		return 0;

		}

	// unlink iterator...

	prev->iNext = next;

	next->iPrev = prev;

	// have we found a mapping?

	if(type==ELink)

		{

		// yes, so insert iterator after it...

		prev = next;

		next = next->iNext;

		prev->iNext = this;

		next->iPrev = this;

		iNext = next;

		iPrev = prev;

		// return mapping...

		DMemoryMappingBase* mapping = (DMemoryMappingBase*)((TLinAddr)prev-_FOFF(DMemoryMappingBase,iLink));

		TRACE2(("TMappingListIter::Next returns 0x%08x",mapping));

		return mapping;

		}

	// handle more complicated situations...

	return Next(next);

	}