/*

* 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:

* Accenture Ltd

*

* Contributors:

*

* Description: This file is a part of sound driver for Syborg adaptation.

*

*/

#include "virtio_queue.h"

// #define ENABLE_QEMU_AUDIO_MODEL_BUG_WORKAROUND

#define ENABLE_QEMU_VIRTIO_CLEANUP_BUG_WORKAROUND

#define PHYS_ADDR(x) Epoc::LinearToPhysical( reinterpret_cast<TUint32>(x))

namespace VirtIo

{

DQueue::DQueue( MIo& aVirtIo, TUint aId, TUint aCount ) 

	: iVirtIo( aVirtIo ), iId( aId ), iCount( aCount )

	{

	}

TInt DQueue::Construct()

	{

	TInt r = AllocQueue();

	if (r!=KErrNone)

		{ return r; }

	PreInitQueue();

	iVirtIo.SetQueueBase( iId, iDesc );

	PostInitQueue();

	return KErrNone;

	}

void DQueue::Wipe()

	{

	if ( iChunk )

		{

		iChunk->Close( NULL );

		iChunk = NULL;

		}

#ifndef ENABLE_QEMU_VIRTIO_CLEANUP_BUG_WORKAROUND		

	if ( iPhysAddr )

		{ Epoc::FreePhysicalRam( iPhysAddr ); }

#endif

	iPhysAddr = 0;

	}

DQueue::~DQueue()

	{

	Wipe();

	}	

//

// Implementation here is that descs are allocated from the one starting with lowest index, 

TInt DQueue::AddBuf( const TAddrLen aScatterList[], TUint32 aOutNum, TUint32 aInNum, Token aToken)

	{

	SYBORG_VIRTIO_DEBUG("AddBuf Q%x %x l%x %x,%x %x",

		iId, aScatterList[0].iAddr, aScatterList[0].iLen, aOutNum, aInNum, aToken );

	TUint outLeft = aOutNum;

	TUint inLeft = aInNum;

	TInt first = -1;

	TInt last = -1;

	TUint totalLen = 0;

	// @TODO maintain freedescs counter to know if the below is going to success from the outset.

	// alloc and initialise descs

	for ( TUint i = 0, j = 0; (i < iCount) && (outLeft+inLeft); ++i )

		{

		if (iDesc[i].iFlags == KFreeDescriptorMarker)

			{

			if (first<0)

				{ first = i; }

			iDesc[i].iFlags = ((outLeft)? 0 : TRingDesc::EFlagWrite);

			iDesc[i].iNext = KFreeDescriptorMarker;

			iDesc[i].iAddr = aScatterList[j].iAddr;

			iDesc[i].iLen = aScatterList[j].iLen;

			totalLen += aScatterList[j].iLen;

			iToken[i].iToken = aToken;

			iToken[i].iTotalLen = 0;

			if ( last >=0 )

				{ 

				iDesc[last].iNext = i; 

				iDesc[last].iFlags |= TRingDesc::EFlagNext;

				}

			last = i;

			if (outLeft) 

				{ --outLeft; }

			else 

				{ --inLeft; }

			j++;

			}

		}

	if (outLeft+inLeft) // rollback descs if not all could have been claimed

		{

		if (first>=0)

			{ FreeDescs(first); }

		SYBORG_VIRTIO_DEBUG("AddBuf Q%x - not ready", iId ); 			

		return KErrNotReady;

		}

	iToken[first].iTotalLen = totalLen;

	// fill a slot in avail ring

	iAvail->iRing[Slot(iAvail->iIdx)] = first;

	++iAvail->iIdx;

	return KErrNone;

	}	

// bases on the assumption that the lowest desc index with given aToken value is used (see addBuf)

// @todo make sure the buffer is not yet posted	

TInt DQueue::DetachBuf( Token aToken )

	{

	TUint myDescId = KFreeDescriptorMarker;

	for ( TIdx i = iNextAvailToSync; i != iAvail->iIdx ; ++i )

		{

		TUint availSlot = Slot( i );

		TUint descId = iAvail->iRing[availSlot];

		if ( descId < iCount )

			{

			if (iToken[descId].iToken == aToken)

				{

				myDescId = descId;

				break;

				}

			}

		}

	if ( myDescId != KFreeDescriptorMarker )

		{ return KErrNotFound; }

	FreeDescs( myDescId );

	return KErrNone;

	}	

Token DQueue::GetBuf( TUint& aLen )

	{

	TIdx usedIdx = iUsed->iIdx;

	ASSERT( ((TIdx)iNextUsedToRead) <= usedIdx );

	if (usedIdx == ((TIdx)iNextUsedToRead))

		{ return 0; }

	TUint nextUsedSlot = Slot(iNextUsedToRead);

	TUint len = iUsed->iRing[nextUsedSlot].iLen;

	TUint descId = iUsed->iRing[nextUsedSlot].iId;

	ASSERT(descId<iCount);

	Token token = iToken[descId].iToken;		

	SYBORG_VIRTIO_DEBUG( "GetBuf Q%x %x ..%x t%x D%x L%x OL%x", iId, iNextUsedToRead, usedIdx, token, descId, len, iToken[descId].iTotalLen );

	++iNextUsedToRead;

	FreeDescs( descId );

#ifdef ENABLE_QEMU_AUDIO_MODEL_BUG_WORKAROUND	

	aLen = len?len:iToken[descId].iTotalLen; // @TODO kind of a hack to solve virtio-audio's failure to report len by syborg on the side of qemu

#else

    aLen = len;

#endif

	return token;

	}	

TInt DQueue::Processing()

	{ return  ((TIdx)(iAvail->iIdx - iFirstEverToSync)) 

		- ((TIdx)(iUsed->iIdx - iFirstEverToRead)); }	

TInt DQueue::Completed()

	{ return  ((TIdx)(iUsed->iIdx - iNextUsedToRead)); }		

void DQueue::Sync()

	{

	SYBORG_VIRTIO_DEBUG("Sync Q%d, %x..%x",

		iId, iNextAvailToSync, iAvail->iIdx );	

	if ( ((TIdx)iNextAvailToSync) == iAvail->iIdx)

		{ return; }

	DumpAvailPending();

	iNextAvailToSync = iAvail->iIdx;

	iVirtIo.PostQueue( iId );

	}

void DQueue::DumpUsedPending()

	{

	for (TIdx i = iNextUsedToRead; i != iUsed->iIdx; ++i )

		{ DumpUsed( Slot(i) ); }

	}	

void DQueue::DumpUsed(TUint usedSlot)

	{

	SYBORG_VIRTIO_DEBUG("Usedslot = %x, aLen = %x, descId=%x", usedSlot, (TUint32) iUsed->iRing[usedSlot].iLen, iUsed->iRing[usedSlot].iId);

	TUint descId = iUsed->iRing[usedSlot].iId;

	DumpDescs( descId );

	}	

void DQueue::DumpAvailPending()

	{

	for (TIdx i = iNextAvailToSync; i != iAvail->iIdx; ++i )

		{ DumpAvail( Slot(i) ); }

	}

void DQueue::DumpAvail(TUint availSlot)

	{

	SYBORG_VIRTIO_DEBUG("Q%d, availslot = %x", iId, availSlot);

	TUint descId = iAvail->iRing[availSlot];

	DumpDescs( descId );

	}

void DQueue::DumpDescs(TUint descId )

	{

	do {

		TRingDesc& d = iDesc[descId];

        if ( (-1) == ((signed)d.iAddr) )

            break;

		SYBORG_VIRTIO_DEBUG(" Desc %x,addr %x, len %x, flags %x, next %x",

			(TUint32)descId, (TUint32)d.iAddr, (TUint32)d.iLen, (TUint32)d.iFlags, (TUint32)d.iNext );

		if ((d.iFlags&TRingDesc::EFlagNext)==0)

			{ break; }

        if ( KFreeDescriptorMarker == d.iNext )

            break;

		descId = d.iNext;

		} while (ETrue);

	}

void DQueue::DumpAll()

	{

	DumpAvailPending();

	DumpUsedPending();

	}	

void DQueue::FreeDescs( TUint firstDescIdx )

	{

	TInt i = firstDescIdx;

	Token token = iToken[firstDescIdx].iToken;

	while (i>=0)

		{

		ASSERT( ( ((TUint)i) < iCount ) );

		TUint flags = iDesc[i].iFlags;

		ASSERT( flags != KFreeDescriptorMarker );

		iDesc[i].iFlags = KFreeDescriptorMarker;

		ASSERT( iToken[i].iToken == token );

		iToken[i].iToken = 0;

		iToken[i].iTotalLen = 0;

        if ((flags&TRingDesc::EFlagNext)==0)

            break;

		i = iDesc[i].iNext;

		}

	}		

TUint8* DQueue::AllocMem( TUint aSize )

	{

	TInt r = KErrNone;

#ifdef ENABLE_QEMU_VIRTIO_CLEANUP_BUG_WORKAROUND		

	// note this is second part of workaround that deals

	// with the issue that memory once assigned to queuebase cannot be 

	// changed,

	// if queuebase != 0 this is because it was set when the driver

	// was loaded previous time

	iPhysAddr = (TUint32) iVirtIo.GetQueueBase( iId );

	iPhysMemReallyAllocated = (iPhysAddr == 0);

	if (iPhysMemReallyAllocated)

		{ r = Epoc::AllocPhysicalRam(aSize, iPhysAddr, 0 ); }

#endif

	if (r!=KErrNone ) 

		{ return NULL; }

	r = DPlatChunkHw::New( iChunk, iPhysAddr, aSize, 

		EMapAttrSupRw | EMapAttrL2Uncached | EMapAttrL1Uncached );

	if (r!=KErrNone ) 

		{

		if ( iPhysMemReallyAllocated )

			{ Epoc::FreePhysicalRam( iPhysAddr, aSize ); }

		iChunk->Close( NULL );

		return NULL;

		}

	ASSERT( r == KErrNone );

	return reinterpret_cast<TUint8*>( iChunk->LinearAddress() );

	}	

TInt DQueue::AllocQueue()

	{

	iDescSize = iCount * sizeof(TRingDesc);

	iAvailSize = sizeof(TRingAvail) + (iCount-1) * sizeof(((TRingAvail*)0)->iRing[0]);

	iTokenSize = iCount * sizeof(TTransactionInfo);

	TUint usedOffset = Align( iDescSize +  iAvailSize, KVirtIoAlignment );

	iUsedSize = sizeof(TRingUsed) + (iCount-1) * sizeof(((TRingUsed*)0)->iRing[0]);

	TUint size = usedOffset + iUsedSize;

	TUint8* iMemAligned;

	iMemAligned = AllocMem( size );

	if (!iMemAligned)

		{ return KErrNoMemory; }

	iDesc = reinterpret_cast<TRingDesc*>( iMemAligned );

	iAvail = reinterpret_cast<TRingAvail*>( iMemAligned + iDescSize );

	iUsed = reinterpret_cast<TRingUsed*>( iMemAligned + usedOffset );

	iToken = reinterpret_cast<TTransactionInfo*>( Kern::Alloc( iTokenSize ) );

	SYBORG_VIRTIO_DEBUG("DQueue %d, Virt iDesc=%x/%x,iAvail=%x/%x,iToken=%x,iUsed=%x/%x",

		iId, iDesc, iDescSize, iAvail, iAvailSize, iToken, iUsed, iUsedSize );

	SYBORG_VIRTIO_DEBUG("DQueue %d, Phys iDesc=%x, iUsed=%x",

		iId, PHYS_ADDR(iDesc), PHYS_ADDR(iUsed) );

	ASSERT( ((PHYS_ADDR(iUsed)-PHYS_ADDR(iDesc))) == ((TUint32)((TUint8*)iUsed-(TUint8*)iDesc)) );

	return KErrNone;

	}	

void DQueue::PreInitQueue()

	{

	memset(iDesc, -1, iDescSize );

	memset( ((TUint8*) iAvail) + 4, -1, iAvailSize - 4 );

	memset( ((TUint8*) iUsed) + 4, -1, iUsedSize - 4 );

	iAvail->iFlags = 0; // no notifications from control queue

	iUsed->iFlags = 0;

	if ( iPhysMemReallyAllocated )

		{

		iAvail->iIdx = 0;

		iUsed->iIdx = 0;

		}

	}	

void DQueue::PostInitQueue()

	{

	iFirstEverToSync = iNextAvailToSync = iAvail->iIdx;

	iFirstEverToRead = iNextUsedToRead = iUsed->iIdx;

	}		

} // namespace VirtIo