kernel/eka/drivers/dma/dma2_pil.cpp
branchRCL_3
changeset 44 3e88ff8f41d5
parent 43 c1f20ce4abcf
child 45 9e2d4f7f5028
--- a/kernel/eka/drivers/dma/dma2_pil.cpp	Tue Aug 31 16:34:26 2010 +0300
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,3131 +0,0 @@
-// Copyright (c) 2002-2010 Nokia Corporation and/or its subsidiary(-ies).
-// All rights reserved.
-// This component and the accompanying materials are made available
-// under the terms of "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/drivers/dma2_pil.cpp
-// DMA Platform Independent Layer (PIL)
-//
-//
-
-#include <drivers/dma.h>
-#include <drivers/dma_hai.h>
-
-#include <kernel/kern_priv.h>
-
-
-// Symbian _Min() & _Max() are broken, so we have to define them ourselves
-inline TUint _Min(TUint aLeft, TUint aRight)
-	{return(aLeft < aRight ? aLeft : aRight);}
-inline TUint _Max(TUint aLeft, TUint aRight)
-	{return(aLeft > aRight ? aLeft : aRight);}
-
-
-// The following section is used only when freezing the DMA2 export library
-/*
-TInt DmaChannelMgr::StaticExtension(TInt, TAny*) {return 0;}
-TDmaChannel* DmaChannelMgr::Open(TUint32, TBool, TUint) {return 0;}
-void DmaChannelMgr::Close(TDmaChannel*) {}
-EXPORT_C const TDmaTestInfo& DmaTestInfo() {static TDmaTestInfo a; return a;}
-EXPORT_C const TDmaV2TestInfo& DmaTestInfoV2() {static TDmaV2TestInfo a; return a;}
-*/
-
-static const char KDmaPanicCat[] = "DMA " __FILE__;
-
-//////////////////////////////////////////////////////////////////////
-// DmaChannelMgr
-//
-// Wait, Signal, and Initialise are defined here in the PIL.
-// Open, Close and Extension must be defined in the PSL.
-
-NFastMutex DmaChannelMgr::Lock;
-
-
-void DmaChannelMgr::Wait()
-	{
-	NKern::FMWait(&Lock);
-	}
-
-
-void DmaChannelMgr::Signal()
-	{
-	NKern::FMSignal(&Lock);
-	}
-
-
-TInt DmaChannelMgr::Initialise()
-	{
-	return KErrNone;
-	}
-
-
-class TDmaCancelInfo : public SDblQueLink
-	{
-public:
-	TDmaCancelInfo();
-	void Signal();
-public:
-	NFastSemaphore iSem;
-	};
-
-
-TDmaCancelInfo::TDmaCancelInfo()
-	: iSem(0)
-	{
-	iNext = this;
-	iPrev = this;
-	}
-
-
-void TDmaCancelInfo::Signal()
-	{
-	TDmaCancelInfo* p = this;
-	FOREVER
-		{
-		TDmaCancelInfo* next = (TDmaCancelInfo*)p->iNext;
-		if (p!=next)
-			p->Deque();
-		NKern::FSSignal(&p->iSem);	// Don't dereference p after this
-		if (p==next)
-			break;
-		p = next;
-		}
-	}
-
-
-//////////////////////////////////////////////////////////////////////////////
-
-#ifdef __DMASIM__
-#ifdef __WINS__
-typedef TLinAddr TPhysAddr;
-#endif
-static inline TPhysAddr LinToPhys(TLinAddr aLin) {return aLin;}
-#else
-static inline TPhysAddr LinToPhys(TLinAddr aLin) {return Epoc::LinearToPhysical(aLin);}
-#endif
-
-//
-// Return minimum of aMaxSize and size of largest physically contiguous block
-// starting at aLinAddr.
-//
-static TUint MaxPhysSize(TLinAddr aLinAddr, const TUint aMaxSize)
-	{
-	const TPhysAddr physBase = LinToPhys(aLinAddr);
-	__DMA_ASSERTD(physBase != KPhysAddrInvalid);
-	TLinAddr lin = aLinAddr;
-	TUint size = 0;
-	for (;;)
-		{
-		// Round up the linear address to the next MMU page boundary
-		const TLinAddr linBoundary = Kern::RoundToPageSize(lin + 1);
-		size += linBoundary - lin;
-		if (size >= aMaxSize)
-			return aMaxSize;
-		if ((physBase + size) != LinToPhys(linBoundary))
-			return size;
-		lin = linBoundary;
-		}
-	}
-
-
-//////////////////////////////////////////////////////////////////////////////
-// TDmac
-
-TDmac::TDmac(const SCreateInfo& aInfo)
-	: iMaxDesCount(aInfo.iDesCount),
-	  iAvailDesCount(aInfo.iDesCount),
-	  iHdrPool(NULL),
-#ifndef __WINS__
-	  iHwDesChunk(NULL),
-#endif
-	  iDesPool(NULL),
-	  iDesSize(aInfo.iDesSize),
-	  iCapsHwDes(aInfo.iCapsHwDes),
-	  iFreeHdr(NULL)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("TDmac::TDmac"));
-	__DMA_ASSERTD(iMaxDesCount > 0);
-	__DMA_ASSERTD(iDesSize > 0);
-	}
-
-
-//
-// Second-phase c'tor
-//
-TInt TDmac::Create(const SCreateInfo& aInfo)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("TDmac::Create"));
-	iHdrPool = new SDmaDesHdr[iMaxDesCount];
-	if (iHdrPool == NULL)
-		{
-		return KErrNoMemory;
-		}
-
-	TInt r = AllocDesPool(aInfo.iDesChunkAttribs);
-	if (r != KErrNone)
-		{
-		return KErrNoMemory;
-		}
-
-	// Link all descriptor headers together on the free list
-	iFreeHdr = iHdrPool;
-	for (TInt i = 0; i < iMaxDesCount - 1; i++)
-		iHdrPool[i].iNext = iHdrPool + i + 1;
-	iHdrPool[iMaxDesCount-1].iNext = NULL;
-
-	__DMA_INVARIANT();
-	return KErrNone;
-	}
-
-
-TDmac::~TDmac()
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("TDmac::~TDmac"));
-	__DMA_INVARIANT();
-
-	FreeDesPool();
-	delete[] iHdrPool;
-	}
-
-
-void TDmac::Transfer(const TDmaChannel& /*aChannel*/, const SDmaDesHdr& /*aHdr*/)
-	{
-	// TDmac needs to override this function if it has reported the channel
-	// type for which the PIL calls it.
-	__DMA_UNREACHABLE_DEFAULT();
-	}
-
-
-void TDmac::Transfer(const TDmaChannel& /*aChannel*/, const SDmaDesHdr& /*aSrcHdr*/,
-					 const SDmaDesHdr& /*aDstHdr*/)
-	{
-	// TDmac needs to override this function if it has reported the channel
-	// type for which the PIL calls it.
-	__DMA_UNREACHABLE_DEFAULT();
-	}
-
-
-TInt TDmac::PauseTransfer(const TDmaChannel& /*aChannel*/)
-	{
-	// TDmac needs to override this function if it has reported support for
-	// channel pausing/resuming.
-	return KErrNotSupported;
-	}
-
-
-TInt TDmac::ResumeTransfer(const TDmaChannel& /*aChannel*/)
-	{
-	// TDmac needs to override this function if it has reported support for
-	// channel pausing/resuming.
-	return KErrNotSupported;
-	}
-
-
-TInt TDmac::AllocDesPool(TUint aAttribs)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("TDmac::AllocDesPool"));
-	// Calling thread must be in CS
-	__ASSERT_CRITICAL;
-	TInt r;
-	if (iCapsHwDes)
-		{
-		const TInt size = iMaxDesCount * iDesSize;
-#ifdef __WINS__
-		(void)aAttribs;
-		iDesPool = new TUint8[size];
-		r = iDesPool ? KErrNone : KErrNoMemory;
-#else
-		// Chunk not mapped as supervisor r/w user none? incorrect mask passed by PSL
-		__DMA_ASSERTD((aAttribs & EMapAttrAccessMask) == EMapAttrSupRw);
-		TPhysAddr phys;
-		r = Epoc::AllocPhysicalRam(size, phys);
-		if (r == KErrNone)
-			{
-			r = DPlatChunkHw::New(iHwDesChunk, phys, size, aAttribs);
-			if (r == KErrNone)
-				{
-				iDesPool = (TAny*)iHwDesChunk->LinearAddress();
-				__KTRACE_OPT(KDMA, Kern::Printf("descriptor hw chunk created lin=0x%08X phys=0x%08X, size=0x%X",
-												iHwDesChunk->iLinAddr, iHwDesChunk->iPhysAddr, size));
-				}
-			else
-				Epoc::FreePhysicalRam(phys, size);
-			}
-#endif
-		}
-	else
-		{
-		iDesPool = Kern::Alloc(iMaxDesCount * sizeof(TDmaTransferArgs));
-		r = iDesPool ? KErrNone : KErrNoMemory;
-		}
-	return r;
-	}
-
-
-void TDmac::FreeDesPool()
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("TDmac::FreeDesPool"));
-	// Calling thread must be in CS
-	__ASSERT_CRITICAL;
-	if (iCapsHwDes)
-		{
-#ifdef __WINS__
-		delete[] iDesPool;
-#else
-		if (iHwDesChunk)
-			{
-			const TPhysAddr phys = iHwDesChunk->PhysicalAddress();
-			const TInt size = iHwDesChunk->iSize;
-			iHwDesChunk->Close(NULL);
-			Epoc::FreePhysicalRam(phys, size);
-			}
-#endif
-		}
-	else
-		{
-		Kern::Free(iDesPool);
-		}
-	}
-
-
-//
-// Prealloc the given number of descriptors.
-//
-TInt TDmac::ReserveSetOfDes(TInt aCount)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("TDmac::ReserveSetOfDes count=%d", aCount));
-	__DMA_ASSERTD(aCount > 0);
-	TInt r = KErrTooBig;
-	Wait();
-	if (iAvailDesCount - aCount >= 0)
-		{
-		iAvailDesCount -= aCount;
-		r = KErrNone;
-		}
-	Signal();
-	__DMA_INVARIANT();
-	return r;
-	}
-
-
-//
-// Return the given number of preallocated descriptors to the free pool.
-//
-void TDmac::ReleaseSetOfDes(TInt aCount)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("TDmac::ReleaseSetOfDes count=%d", aCount));
-	__DMA_ASSERTD(aCount >= 0);
-	Wait();
-	iAvailDesCount += aCount;
-	Signal();
-	__DMA_INVARIANT();
-	}
-
-
-//
-// Queue DFC and update word used to communicate with channel DFC.
-//
-// Called in interrupt context by PSL.
-//
-void TDmac::HandleIsr(TDmaChannel& aChannel, TUint aEventMask, TBool aIsComplete)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("TDmac::HandleIsr"));
-
-	// Function needs to be called by PSL in ISR context
-	__DMA_ASSERTD(NKern::CurrentContext() == NKern::EInterrupt);
-
-	// First the ISR callback stuff
-
-	// Is this a transfer completion notification?
-	if (aEventMask & EDmaCallbackRequestCompletion)
-		{
-		// If so, has the client requested an ISR callback?
-		if (__e32_atomic_load_acq32(&aChannel.iIsrCbRequest))
-			{
-			__KTRACE_OPT(KDMA, Kern::Printf("ISR callback"));
-
-			// Since iIsrCbRequest was set no threads will be
-			// modifying the request queue.
-			const DDmaRequest* const req = _LOFF(aChannel.iReqQ.First(), DDmaRequest, iLink);
-
-			// We expect the request to have requested
-			// ISR callback
-			__NK_ASSERT_DEBUG(req->iIsrCb);
-
-			TDmaCallback const cb = req->iDmaCb;
-			TAny* const arg = req->iDmaCbArg;
-			// Execute the client callback
-			(*cb)(EDmaCallbackRequestCompletion,
-				  (aIsComplete ? EDmaResultOK : EDmaResultError),
-				  arg,
-				  NULL);
-			// Now let's see if the callback rescheduled the transfer request
-			// (see TDmaChannel::IsrRedoRequest()).
-			const TBool redo = aChannel.iRedoRequest;
-			aChannel.iRedoRequest = EFalse;
-			const TBool stop = __e32_atomic_load_acq32(&aChannel.iIsrDfc) &
-				(TUint32)TDmaChannel::KCancelFlagMask;
-			// There won't be another ISR callback if this callback didn't
-			// reschedule the request, or the client cancelled all requests, or
-			// this callback rescheduled the request with a DFC callback.
-			if (!redo || stop || !req->iIsrCb)
-				{
-				__e32_atomic_store_rel32(&aChannel.iIsrCbRequest, EFalse);
-				}
-			if (redo && !stop)
-				{
-				// We won't queue the channel DFC in this case and just return.
-				__KTRACE_OPT(KDMA, Kern::Printf("CB rescheduled xfer -> no DFC"));
-				return;
-				}
-			// Not redoing or being cancelled means we've been calling the
-			// request's ISR callback for the last time. We're going to
-			// complete the request via the DFC in the usual way.
-			}
-		}
-	else
-		{
-		// The PIL doesn't support yet any completion types other than
-		// EDmaCallbackRequestCompletion.
-		__DMA_CANT_HAPPEN();
-		}
-
-	// Now queue a DFC if necessary. The possible scenarios are:
-	// a) DFC not queued (orig == 0)              -> update iIsrDfc + queue DFC
-	// b) DFC queued, not running yet (orig != 0) -> just update iIsrDfc
-	// c) DFC running / iIsrDfc not reset yet (orig != 0) -> just update iIsrDfc
-	// d) DFC running / iIsrDfc already reset (orig == 0) -> update iIsrDfc + requeue DFC
-
-	// Set error flag if necessary.
-	const TUint32 inc = aIsComplete ? 1u : TUint32(TDmaChannel::KErrorFlagMask) | 1u;
-
-	// Add 'inc' (interrupt count increment + poss. error flag) to 'iIsrDfc' if
-	// cancel flag is not set, do nothing otherwise. Assign original value of
-	// 'iIsrDfc' to 'orig' in any case.
-	const TUint32 orig = __e32_atomic_tau_ord32(&aChannel.iIsrDfc,
-												TUint32(TDmaChannel::KCancelFlagMask),
-												0,
-												inc);
-
-	// As transfer should be suspended when an error occurs, we
-	// should never get there with the error flag already set.
-	__DMA_ASSERTD((orig & inc & (TUint32)TDmaChannel::KErrorFlagMask) == 0);
-
-	if (orig == 0)
-		{
-		aChannel.iDfc.Add();
-		}
-	}
-
-
-TInt TDmac::InitDes(const SDmaDesHdr& aHdr, const TDmaTransferArgs& aTransferArgs)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("TDmac::InitDes"));
-	TInt r;
-	if (iCapsHwDes)
-		{
-		__KTRACE_OPT(KDMA, Kern::Printf("iCaps.iHwDescriptors"));
-		r = InitHwDes(aHdr, aTransferArgs);
-		}
-	else
-		{
-		TDmaTransferArgs& args = HdrToDes(aHdr);
-		args = aTransferArgs;
-		r = KErrNone;
-		}
-	return r;
-	}
-
-
-TInt TDmac::InitHwDes(const SDmaDesHdr& /*aHdr*/, const TDmaTransferArgs& /*aTransferArgs*/)
-	{
-	// concrete controller must override if SDmacCaps::iHwDescriptors set
-	__DMA_UNREACHABLE_DEFAULT();
-	return KErrGeneral;
-	}
-
-
-TInt TDmac::InitSrcHwDes(const SDmaDesHdr& /*aHdr*/, const TDmaTransferArgs& /*aTransferArgs*/)
-	{
-	// concrete controller must override if SDmacCaps::iAsymHwDescriptors set
-	__DMA_UNREACHABLE_DEFAULT();
-	return KErrGeneral;
-	}
-
-
-TInt TDmac::InitDstHwDes(const SDmaDesHdr& /*aHdr*/, const TDmaTransferArgs& /*aTransferArgs*/)
-	{
-	// concrete controller must override if SDmacCaps::iAsymHwDescriptors set
-	__DMA_UNREACHABLE_DEFAULT();
-	return KErrGeneral;
-	}
-
-
-TInt TDmac::UpdateDes(const SDmaDesHdr& aHdr, TUint32 aSrcAddr, TUint32 aDstAddr,
-					  TUint aTransferCount, TUint32 aPslRequestInfo)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("TDmac::UpdateDes"));
-	TInt r;
-	if (iCapsHwDes)
-		{
-		__KTRACE_OPT(KDMA, Kern::Printf("iCaps.iHwDescriptors"));
-		r = UpdateHwDes(aHdr, aSrcAddr, aDstAddr, aTransferCount, aPslRequestInfo);
-		}
-	else
-		{
-		TDmaTransferArgs& args = HdrToDes(aHdr);
-		if (aSrcAddr != KPhysAddrInvalid)
-			args.iSrcConfig.iAddr = aSrcAddr;
-		if (aDstAddr != KPhysAddrInvalid)
-			args.iDstConfig.iAddr = aDstAddr;
-		if (aTransferCount)
-			args.iTransferCount = aTransferCount;
-		if (aPslRequestInfo)
-			args.iPslRequestInfo = aPslRequestInfo;
-		r = KErrNone;
-		}
-	return r;
-	}
-
-
-TInt TDmac::UpdateHwDes(const SDmaDesHdr& /*aHdr*/, TUint32 /*aSrcAddr*/, TUint32 /*aDstAddr*/,
-						TUint /*aTransferCount*/, TUint32 /*aPslRequestInfo*/)
-	{
-	// concrete controller must override if SDmacCaps::iHwDescriptors set
-	__DMA_UNREACHABLE_DEFAULT();
-	return KErrGeneral;
-	}
-
-
-TInt TDmac::UpdateSrcHwDes(const SDmaDesHdr& /*aHdr*/, TUint32 /*aSrcAddr*/,
-						   TUint /*aTransferCount*/, TUint32 /*aPslRequestInfo*/)
-	{
-	// concrete controller must override if SDmacCaps::iAsymHwDescriptors set
-	__DMA_UNREACHABLE_DEFAULT();
-	return KErrGeneral;
-	}
-
-
-TInt TDmac::UpdateDstHwDes(const SDmaDesHdr& /*aHdr*/, TUint32 /*aDstAddr*/,
-						   TUint /*aTransferCount*/, TUint32 /*aPslRequestInfo*/)
-	{
-	// concrete controller must override if SDmacCaps::iAsymHwDescriptors set
-	__DMA_UNREACHABLE_DEFAULT();
-	return KErrGeneral;
-	}
-
-
-void TDmac::ChainHwDes(const SDmaDesHdr& /*aHdr*/, const SDmaDesHdr& /*aNextHdr*/)
-	{
-	// concrete controller must override if SDmacCaps::iHwDescriptors set
-	__DMA_UNREACHABLE_DEFAULT();
-	}
-
-
-void TDmac::AppendHwDes(const TDmaChannel& /*aChannel*/, const SDmaDesHdr& /*aLastHdr*/,
-						const SDmaDesHdr& /*aNewHdr*/)
-	{
- 	// concrete controller must override if SDmacCaps::iHwDescriptors set
-	__DMA_UNREACHABLE_DEFAULT();
-	}
-
-
-void TDmac::AppendHwDes(const TDmaChannel& /*aChannel*/,
-						const SDmaDesHdr& /*aSrcLastHdr*/, const SDmaDesHdr& /*aSrcNewHdr*/,
-						const SDmaDesHdr& /*aDstLastHdr*/, const SDmaDesHdr& /*aDstNewHdr*/)
-	{
-	// concrete controller must override if SDmacCaps::iAsymHwDescriptors set
-	__DMA_UNREACHABLE_DEFAULT();
-	}
-
-
-void TDmac::UnlinkHwDes(const TDmaChannel& /*aChannel*/, SDmaDesHdr& /*aHdr*/)
-	{
- 	// concrete controller must override if SDmacCaps::iHwDescriptors set
-	__DMA_UNREACHABLE_DEFAULT();
-	}
-
-
-void TDmac::ClearHwDes(const SDmaDesHdr& /*aHdr*/)
-	{
-	// default implementation - NOP; concrete controller may override
-	return;
-	}
-
-
-TInt TDmac::LinkChannels(TDmaChannel& /*a1stChannel*/, TDmaChannel& /*a2ndChannel*/)
-	{
-	// default implementation - NOP; concrete controller may override
-	return KErrNotSupported;
-	}
-
-
-TInt TDmac::UnlinkChannel(TDmaChannel& /*aChannel*/)
-	{
-	// default implementation - NOP; concrete controller may override
-	return KErrNotSupported;
-	}
-
-
-TInt TDmac::FailNext(const TDmaChannel& /*aChannel*/)
-	{
-	// default implementation - NOP; concrete controller may override
-	return KErrNotSupported;
-	}
-
-
-TInt TDmac::MissNextInterrupts(const TDmaChannel& /*aChannel*/, TInt /*aInterruptCount*/)
-	{
-	// default implementation - NOP; concrete controller may override
-	return KErrNotSupported;
-	}
-
-
-TInt TDmac::Extension(TDmaChannel& /*aChannel*/, TInt /*aCmd*/, TAny* /*aArg*/)
-	{
-	// default implementation - NOP; concrete controller may override
-	return KErrNotSupported;
-	}
-
-
-TUint32 TDmac::HwDesNumDstElementsTransferred(const SDmaDesHdr& /*aHdr*/)
-	{
- 	// Concrete controller must override if SDmacCaps::iHwDescriptors set.
-	__DMA_UNREACHABLE_DEFAULT();
-	return 0;
-	}
-
-
-TUint32 TDmac::HwDesNumSrcElementsTransferred(const SDmaDesHdr& /*aHdr*/)
-	{
- 	// Concrete controller must override if SDmacCaps::iHwDescriptors set.
-	__DMA_UNREACHABLE_DEFAULT();
-	return 0;
-	}
-
-
-#ifdef _DEBUG
-
-void TDmac::Invariant()
-	{
-	Wait();
-	__DMA_ASSERTD(0 <= iAvailDesCount && iAvailDesCount <= iMaxDesCount);
-	__DMA_ASSERTD(!iFreeHdr || IsValidHdr(iFreeHdr));
-	for (TInt i = 0; i < iMaxDesCount; i++)
-		__DMA_ASSERTD(iHdrPool[i].iNext == NULL || IsValidHdr(iHdrPool[i].iNext));
-	Signal();
-	}
-
-
-TBool TDmac::IsValidHdr(const SDmaDesHdr* aHdr)
-	{
-	return (iHdrPool <= aHdr) && (aHdr < iHdrPool + iMaxDesCount);
-	}
-
-#endif
-
-
-//
-// Internal compat version, used by legacy Fragment()
-//
-TDmaTransferConfig::TDmaTransferConfig(TUint32 aAddr, TUint aFlags, TBool aAddrInc)
-	: iAddr(aAddr),
-	  iAddrMode(aAddrInc ? KDmaAddrModePostIncrement : KDmaAddrModeConstant),
-	  iElementSize(0),
-	  iElementsPerFrame(0),
-	  iElementsPerPacket(0),
-	  iFramesPerTransfer(0),
-	  iElementSkip(0),
-	  iFrameSkip(0),
-	  iBurstSize(KDmaBurstSizeAny),
-	  iFlags(aFlags),
-	  iSyncFlags(KDmaSyncAuto),
-	  iPslTargetInfo(0),
-	  iRepeatCount(0),
-	  iDelta(~0u),
-	  iReserved(0)
-	{
-	__KTRACE_OPT(KDMA,
-				 Kern::Printf("TDmaTransferConfig::TDmaTransferConfig "
-							  "aAddr=0x%08X aFlags=0x%08X aAddrInc=%d",
-							  aAddr, aFlags, aAddrInc));
-	}
-
-
-//
-// Internal compat version, used by legacy Fragment()
-//
-TDmaTransferArgs::TDmaTransferArgs(TUint32 aSrc, TUint32 aDest, TInt aCount,
-								   TUint aFlags, TUint32 aPslInfo)
-	: iSrcConfig(aSrc, RequestFlags2SrcConfigFlags(aFlags), (aFlags & KDmaIncSrc)),
-	  iDstConfig(aDest, RequestFlags2DstConfigFlags(aFlags), (aFlags & KDmaIncDest)),
-	  iTransferCount(aCount),
-	  iGraphicsOps(KDmaGraphicsOpNone),
-	  iColour(0),
-	  iFlags(0),
-	  iChannelPriority(KDmaPriorityNone),
-	  iPslRequestInfo(aPslInfo),
-	  iChannelCookie(0),
-	  iDelta(~0u),
-	  iReserved1(0),
-	  iReserved2(0)
-	{
-	__KTRACE_OPT(KDMA,
-				 Kern::Printf("TDmaTransferArgs::TDmaTransferArgs"));
-	__KTRACE_OPT(KDMA,
-				 Kern::Printf("  aSrc=0x%08X aDest=0x%08X aCount=%d aFlags=0x%08X aPslInfo=0x%08X",
-							  aSrc, aDest, aCount, aFlags, aPslInfo));
-	}
-
-
-//
-// As DDmaRequest is derived from DBase, the initializations with zero aren't
-// strictly necessary here, but this way it's nicer.
-//
-EXPORT_C DDmaRequest::DDmaRequest(TDmaChannel& aChannel, TCallback aCb,
-								  TAny* aCbArg, TInt aMaxTransferSize)
-	: iChannel(aChannel),
-	  iCb(aCb),
-	  iCbArg(aCbArg),
-	  iDmaCb(NULL),
-	  iDmaCbArg(NULL),
-	  iIsrCb(EFalse),
-	  iDesCount(0),
-	  iFirstHdr(NULL),
-	  iLastHdr(NULL),
-	  iSrcDesCount(0),
-	  iSrcFirstHdr(NULL),
-	  iSrcLastHdr(NULL),
-	  iDstDesCount(0),
-	  iDstFirstHdr(NULL),
-	  iDstLastHdr(NULL),
-	  iQueued(EFalse),
-	  iMaxTransferSize(aMaxTransferSize),
-	  iTotalNumSrcElementsTransferred(0),
-	  iTotalNumDstElementsTransferred(0)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::DDmaRequest =0x%08X (old style)", this));
-	iChannel.iReqCount++;
-	__DMA_ASSERTD(0 <= aMaxTransferSize);
-	__DMA_INVARIANT();
-	}
-
-
-//
-// As DDmaRequest is derived from DBase, the initializations with zero aren't
-// strictly necessary here, but this way it's nicer.
-//
-EXPORT_C DDmaRequest::DDmaRequest(TDmaChannel& aChannel, TDmaCallback aDmaCb,
-								  TAny* aCbArg, TUint aMaxTransferSize)
-	: iChannel(aChannel),
-	  iCb(NULL),
-	  iCbArg(NULL),
-	  iDmaCb(aDmaCb),
-	  iDmaCbArg(aCbArg),
-	  iIsrCb(EFalse),
-	  iDesCount(0),
-	  iFirstHdr(NULL),
-	  iLastHdr(NULL),
-	  iSrcDesCount(0),
-	  iSrcFirstHdr(NULL),
-	  iSrcLastHdr(NULL),
-	  iDstDesCount(0),
-	  iDstFirstHdr(NULL),
-	  iDstLastHdr(NULL),
-	  iQueued(EFalse),
-	  iMaxTransferSize(aMaxTransferSize),
-	  iTotalNumSrcElementsTransferred(0),
-	  iTotalNumDstElementsTransferred(0)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::DDmaRequest =0x%08X (new style)", this));
-	__e32_atomic_add_ord32(&iChannel.iReqCount, 1);
-	__DMA_INVARIANT();
-	}
-
-
-EXPORT_C DDmaRequest::~DDmaRequest()
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::~DDmaRequest"));
-	__DMA_ASSERTD(!iQueued);
-	__DMA_INVARIANT();
-	if (iChannel.iDmacCaps->iAsymHwDescriptors)
-		{
-		FreeSrcDesList();
-		FreeDstDesList();
-		}
-	else
-		{
-		FreeDesList();
-		}
-	__e32_atomic_add_ord32(&iChannel.iReqCount, TUint32(-1));
-	}
-
-
-EXPORT_C TInt DDmaRequest::Fragment(TUint32 aSrc, TUint32 aDest, TInt aCount,
-									TUint aFlags, TUint32 aPslInfo)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::Fragment thread %O (old style)",
-									&Kern::CurrentThread()));
-
-	__DMA_ASSERTD(aCount > 0);
-
-	TDmaTransferArgs args(aSrc, aDest, aCount, aFlags, aPslInfo);
-
-	return Frag(args);
-	}
-
-
-EXPORT_C TInt DDmaRequest::Fragment(const TDmaTransferArgs& aTransferArgs)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::Fragment thread %O (new style)",
-									&Kern::CurrentThread()));
-
-	// Writable temporary working copy of the transfer arguments.
-	// We need this because we may have to modify some fields before passing it
-	// to the PSL (for example iChannelCookie, iTransferCount,
-	// iDstConfig::iAddr, and iSrcConfig::iAddr).
-	TDmaTransferArgs args(aTransferArgs);
-
-	return Frag(args);
-	}
-
-
-TInt DDmaRequest::CheckTransferConfig(const TDmaTransferConfig& aTarget, TUint aCount) const
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::CheckTransferConfig"));
-
-	if (aTarget.iElementSize != 0)
-		{
-		if ((aCount % aTarget.iElementSize) != 0)
-			{
-			// 2, 7 (These strange numbers refer to some test cases documented
-			// elsewhere - they will be removed eventually.)
-			__KTRACE_OPT(KPANIC,
-						 Kern::Printf("Error: ((aCount %% iElementSize) != 0)"));
-			return KErrArgument;
-			}
-		if (aTarget.iElementsPerFrame != 0)
-			{
-			if ((aTarget.iElementSize * aTarget.iElementsPerFrame *
-				 aTarget.iFramesPerTransfer) != aCount)
-				{
-				// 3, 8
-				__KTRACE_OPT(KPANIC,
-							 Kern::Printf("Error: ((iElementSize * "
-										  "iElementsPerFrame * "
-										  "iFramesPerTransfer) != aCount)"));
-				return KErrArgument;
-				}
-			}
-		}
-	else
-		{
-		if (aTarget.iElementsPerFrame != 0)
-			{
-			// 4, 9
-			__KTRACE_OPT(KPANIC,
-						 Kern::Printf("Error: (iElementsPerFrame != 0)"));
-			return KErrArgument;
-			}
-		if (aTarget.iFramesPerTransfer != 0)
-			{
-			// 5, 10
-			__KTRACE_OPT(KPANIC,
-						 Kern::Printf("Error: (iFramesPerTransfer != 0)"));
-			return KErrArgument;
-			}
-		if (aTarget.iElementsPerPacket != 0)
-			{
-			// 6, 11
-			__KTRACE_OPT(KPANIC,
-						 Kern::Printf("Error: (iElementsPerPacket != 0)"));
-			return KErrArgument;
-			}
-		}
-	return KErrNone;
-	}
-
-
-TInt DDmaRequest::CheckMemFlags(const TDmaTransferConfig& aTarget) const
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::CheckMemFlags"));
-
-	const TBool mem_target = (aTarget.iFlags & KDmaMemAddr);
-
-	if (mem_target && (aTarget.iFlags & KDmaPhysAddr) && !(aTarget.iFlags & KDmaMemIsContiguous))
-		{
-		// Physical memory address implies contiguous range
-		// 13, 15
-		__KTRACE_OPT(KPANIC, Kern::Printf("Error: mem_target && KDmaPhysAddr && !KDmaMemIsContiguous"));
-		return KErrArgument;
-		}
-	else if ((aTarget.iFlags & KDmaMemIsContiguous) && !mem_target)
-		{
-		// Contiguous range implies memory address
-		// 14, 16
-		__KTRACE_OPT(KPANIC, Kern::Printf("Error: KDmaMemIsContiguous && !mem_target"));
-		return KErrArgument;
-		}
-	return KErrNone;
-	}
-
-
-// Makes sure an element or frame never straddles two DMA subtransfer
-// fragments. This would be a fragmentation error by the PIL.
-//
-TInt DDmaRequest::AdjustFragmentSize(TUint& aFragSize, TUint aElementSize,
-									 TUint aFrameSize)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::AdjustFragmentSize FragSize=%d ES=%d FS=%d",
-									aFragSize, aElementSize, aFrameSize));
-
-	TUint rem = 0;
-	TInt r = KErrNone;
-
-	FOREVER
-		{
-		// If an element size is defined, make sure the fragment size is
-		// greater or equal.
-		if (aElementSize)
-			{
-			if (aFragSize < aElementSize)
-				{
-				__KTRACE_OPT(KPANIC, Kern::Printf("Error: aFragSize < aElementSize"));
-				r = KErrArgument;
-				break;
-				}
-			}
-		// If a frame size is defined, make sure the fragment size is greater
-		// or equal.
-		if (aFrameSize)
-			{
-			if (aFragSize < aFrameSize)
-				{
-				__KTRACE_OPT(KPANIC, Kern::Printf("Error: aFragSize < aFrameSize"));
-				r = KErrArgument;
-				break;
-				}
-			}
-		// If a frame size is defined, make sure the fragment ends on a frame
-		// boundary.
-		if (aFrameSize)
-			{
-			rem = aFragSize % aFrameSize;
-			if (rem != 0)
-				{
-				aFragSize -= rem;
-				// 20, 22
-				__KTRACE_OPT(KDMA, Kern::Printf("aFragSize %% aFrameSize != 0 --> aFragSize = %d",
-												aFragSize));
-				// aFragSize has changed, so we have to do all the checks
-				// again.
-				continue;
-				}
-			}
-		// If an element size is defined, make sure the fragment ends on an
-		// element boundary.
-		if (aElementSize)
-			{
-			rem = aFragSize % aElementSize;
-			if (rem != 0)
-				{
-				aFragSize -= rem;
-				// 21, 23
-				__KTRACE_OPT(KDMA, Kern::Printf("aFragSize %% aElementSize != 0 --> aFragSize = %d",
-												aFragSize));
-				// aFragSize has changed, so we have to do all the checks
-				// again.
-				continue;
-				}
-			}
-		// Done - all checks passed. Let's get out.
-		break;
-		}
-
-	return r;
-	}
-
-
-TUint DDmaRequest::GetTransferCount(const TDmaTransferArgs& aTransferArgs) const
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::GetTransferCount"));
-
-	const TDmaTransferConfig& src = aTransferArgs.iSrcConfig;
-#ifdef _DEBUG
-	const TDmaTransferConfig& dst = aTransferArgs.iDstConfig;
-#endif	// #ifdef _DEBUG
-
-	TUint count = aTransferArgs.iTransferCount;
-	if (count == 0)
-		{
-		__KTRACE_OPT(KDMA, Kern::Printf("iTransferCount == 0"));
-		count = src.iElementSize * src.iElementsPerFrame *
-			src.iFramesPerTransfer;
-#ifdef _DEBUG
-		const TUint dst_cnt = dst.iElementSize * dst.iElementsPerFrame *
-			dst.iFramesPerTransfer;
-		if (count != dst_cnt)
-			{
-			// 1
-			__KTRACE_OPT(KPANIC, Kern::Printf("Error: (count != dst_cnt)"));
-			return 0;
-			}
-#endif	// #ifdef _DEBUG
-		}
-	else
-		{
-		__KTRACE_OPT(KDMA, Kern::Printf("iTransferCount == %d", count));
-#ifdef _DEBUG
-		// Client shouldn't specify contradictory or incomplete things
-		if (CheckTransferConfig(src, count) != KErrNone)
-			{
-			__KTRACE_OPT(KPANIC, Kern::Printf("Error: CheckTransferConfig(src)"));
-			return 0;
-			}
-		if (CheckTransferConfig(dst, count) != KErrNone)
-			{
-			__KTRACE_OPT(KPANIC, Kern::Printf("Error: CheckTransferConfig(dst)"));
-			return 0;
-			}
-#endif	// #ifdef _DEBUG
-		}
-	return count;
-	}
-
-
-TUint DDmaRequest::GetMaxTransferlength(const TDmaTransferArgs& aTransferArgs, TUint aCount) const
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::GetMaxTransferlength"));
-
-	const TDmaTransferConfig& src = aTransferArgs.iSrcConfig;
-	const TDmaTransferConfig& dst = aTransferArgs.iDstConfig;
-
-	// Ask the PSL what the maximum length is for a single transfer
-	TUint max_xfer_len = iChannel.MaxTransferLength(src.iFlags, dst.iFlags,
-													aTransferArgs.iPslRequestInfo);
-	if (iMaxTransferSize)
-		{
-		// (User has set a transfer size cap)
-		__KTRACE_OPT(KDMA, Kern::Printf("iMaxTransferSize: %d", iMaxTransferSize));
-		if ((max_xfer_len != 0) && (iMaxTransferSize > max_xfer_len))
-			{
-			// Not really an error, but still...
-			__KTRACE_OPT(KPANIC, Kern::Printf("Warning: iMaxTransferSize > max_xfer_len"));
-			}
-		max_xfer_len = iMaxTransferSize;
-		}
-	else
-		{
-		// (User doesn't care about max transfer size)
-		if (max_xfer_len == 0)
-			{
-			// '0' = no maximum imposed by controller
-			max_xfer_len = aCount;
-			}
-		}
-	__KTRACE_OPT(KDMA, Kern::Printf("max_xfer_len: %d", max_xfer_len));
-
-	// Some sanity checks
-#ifdef _DEBUG
-	if ((max_xfer_len < src.iElementSize) || (max_xfer_len < dst.iElementSize))
-		{
-		// 18
-		__KTRACE_OPT(KPANIC, Kern::Printf("Error: max_xfer_len < iElementSize"));
-		return 0;
-		}
-	if ((max_xfer_len < (src.iElementSize * src.iElementsPerFrame)) ||
-		(max_xfer_len < (dst.iElementSize * dst.iElementsPerFrame)))
-		{
-		// 19
-		__KTRACE_OPT(KPANIC,
-					 Kern::Printf("Error: max_xfer_len < (iElementSize * iElementsPerFrame)"));
-		return 0;
-		}
-#endif	// #ifdef _DEBUG
-
-	return max_xfer_len;
-	}
-
-
-// Unified internal fragmentation routine, called by both the old and new
-// exported Fragment() functions.
-//
-// Depending on whether the DMAC uses a single or two separate descriptor
-// chains, this function branches into either FragSym() or FragAsym(), and the
-// latter function further into either FragAsymSrc()/FragAsymDst() or
-// FragBalancedAsym().
-//
-TInt DDmaRequest::Frag(TDmaTransferArgs& aTransferArgs)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::Frag"));
-	__DMA_ASSERTD(!iQueued);
-
-	// Transfer count + checks
-	const TUint count = GetTransferCount(aTransferArgs);
-	if (count == 0)
-		{
-		return KErrArgument;
-		}
-
-	// Max transfer length + checks
-	const TUint max_xfer_len = GetMaxTransferlength(aTransferArgs, count);
-	if (max_xfer_len == 0)
-		{
-		return KErrArgument;
-		}
-
-	// ISR callback requested?
-	const TBool isr_cb = (aTransferArgs.iFlags & KDmaRequestCallbackFromIsr);
-	if (isr_cb)
-		{
-		// Requesting an ISR callback w/o supplying one?
-		if (!iDmaCb)
-			{
-			// 12
-			__KTRACE_OPT(KPANIC, Kern::Printf("Error: !iDmaCb"));
-			return KErrArgument;
-			}
-		}
-
-	// Set the channel cookie for the PSL
-	aTransferArgs.iChannelCookie = iChannel.PslId();
-
-	// Client shouldn't specify contradictory or invalid things
-	TInt r = CheckMemFlags(aTransferArgs.iSrcConfig);
-	if (r != KErrNone)
-		{
-		__KTRACE_OPT(KPANIC, Kern::Printf("Error: CheckMemFlags(src)"));
-		return r;
-		}
-	r =  CheckMemFlags(aTransferArgs.iDstConfig);
-	if (r != KErrNone)
-		{
-		__KTRACE_OPT(KPANIC, Kern::Printf("Error: CheckMemFlags(dst)"));
-		return r;
-		}
-
-	// Now the actual fragmentation
-	if (iChannel.iDmacCaps->iAsymHwDescriptors)
-		{
-		r = FragAsym(aTransferArgs, count, max_xfer_len);
-		}
-	else
-		{
-		r = FragSym(aTransferArgs, count, max_xfer_len);
-		}
-
-	if (r == KErrNone)
-		{
-		iIsrCb = isr_cb;
-		}
-
-	__DMA_INVARIANT();
-	return r;
-	};
-
-
-TInt DDmaRequest::FragSym(TDmaTransferArgs& aTransferArgs, TUint aCount,
-						  TUint aMaxTransferLen)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::FragSym"));
-
-	TDmaTransferConfig& src = aTransferArgs.iSrcConfig;
-	TDmaTransferConfig& dst = aTransferArgs.iDstConfig;
-	const TBool mem_src = (src.iFlags & KDmaMemAddr);
-	const TBool mem_dst = (dst.iFlags & KDmaMemAddr);
-
-	const TUint align_mask_src = iChannel.AddressAlignMask(src.iFlags,
-														   src.iElementSize,
-														   aTransferArgs.iPslRequestInfo);
-	__KTRACE_OPT(KDMA, Kern::Printf("align_mask_src: 0x%x", align_mask_src));
-	const TUint align_mask_dst = iChannel.AddressAlignMask(dst.iFlags,
-														   dst.iElementSize,
-														   aTransferArgs.iPslRequestInfo);
-	__KTRACE_OPT(KDMA, Kern::Printf("align_mask_dst: 0x%x", align_mask_dst));
-
-	// Memory buffers must satisfy alignment constraint
-	__DMA_ASSERTD(!mem_src || ((src.iAddr & align_mask_src) == 0));
-	__DMA_ASSERTD(!mem_dst || ((dst.iAddr & align_mask_dst) == 0));
-
-	// Max aligned length is used to make sure the beginnings of subtransfers
-	// (i.e. fragments) are correctly aligned.
-	const TUint max_aligned_len = (aMaxTransferLen &
-								   ~(_Max(align_mask_src, align_mask_dst)));
-	__KTRACE_OPT(KDMA, Kern::Printf("max_aligned_len: %d", max_aligned_len));
-	// Client and PSL sane?
-	__DMA_ASSERTD(max_aligned_len > 0);
-
-	if (mem_src && mem_dst &&
-		align_mask_src && align_mask_dst &&
-		(align_mask_src != align_mask_dst) &&
-		(!(src.iFlags & KDmaMemIsContiguous) || !(dst.iFlags & KDmaMemIsContiguous)))
-		{
-		// We don't support transfers which satisfy ALL of the following conditions:
-		// 1) from memory to memory,
-		// 2) both sides have address alignment requirements,
-		// 3) those alignment requirements are not the same,
-		// 4) the memory is non-contiguous on at least one end.
-		//
-		// [A 5th condition is that the channel doesn't support fully
-		// asymmetric h/w descriptor lists,
-		// i.e. TDmaChannel::DmacCaps::iAsymHwDescriptors is reported as EFalse
-		// or iBalancedAsymSegments as ETrue. Hence this check is done in
-		// FragSym() and FragBalancedAsym() but not in FragAsym().]
-		//
-		// The reason for this is that fragmentation could be impossible. The
-		// memory layout (page break) on the side with the less stringent
-		// alignment requirement can result in a misaligned target address on
-		// the other side.
-		//
-		// Here is an example:
-		//
-		// src.iAddr =  3964 (0x0F7C), non-contiguous,
-		// align_mask_src = 1 (alignment = 2 bytes)
-		// dst.iAddr = 16384 (0x4000), contiguous,
-		// align_mask_dst = 7 (alignment = 8 bytes)
-		// count = max_xfer_len = 135 bytes
-		// => max_aligned_len = 128 bytes
-		//
-		// Now, suppose MaxPhysSize() returns 132 bytes because src has 132
-		// contiguous bytes to the end of its current mem page.
-		// Trying to fragment this leads to:
-		//
-		// frag_1 = 128 bytes: src reads from 3964 (0x0F7C),
-		//                     dst writes to 16384 (0x4000).
-		// (Fragment 1 uses the max_aligned_len instead of 132 bytes because
-		// otherwise the next fragment would start for the destination at
-		// dst.iAddr + 132 = 16516 (0x4084), which is not 8-byte aligned.)
-		//
-		// frag_2 = 4 bytes: src reads from 4092 (0x0FFC),
-		//                   dst writes to 16512 (0x4080).
-		// (Fragment 2 uses just 4 bytes instead of the remaining 7 bytes
-		// because there is a memory page break on the source side after 4 bytes.)
-		//
-		// frag_3 = 3 bytes: src reads from 4096 (0x1000),
-		//                   dst writes to 16516 (0x4084).
-		//
-		// And there's the problem: the start address of frag_3 is going to be
-		// misaligned for the destination side - it's not 8-byte aligned!
-		//
-		// 17
-		__KTRACE_OPT(KPANIC, Kern::Printf("Error: Different alignments for src & dst"
-										  " + non-contiguous target(s)"));
-		return KErrArgument;
-		}
-
-	TInt r;
-	// Revert any previous fragmentation attempt
-	FreeDesList();
-	do
-		{
-		// Allocate fragment
-		r = ExpandDesList(/*1*/);
-		if (r != KErrNone)
-			{
-			break;
-			}
-		// Compute fragment size
-		TUint c = _Min(aMaxTransferLen, aCount);
-		__KTRACE_OPT(KDMA, Kern::Printf("c = _Min(aMaxTransferLen, aCount) = %d", c));
-
-		// SRC
-		if (mem_src && !(src.iFlags & KDmaMemIsContiguous))
-			{
-			c = MaxPhysSize(src.iAddr, c);
-			__KTRACE_OPT(KDMA, Kern::Printf("c = MaxPhysSize(src.iAddr, c) = %d", c));
-			}
-
-		// DST
-		if (mem_dst && !(dst.iFlags & KDmaMemIsContiguous))
-			{
-			c = MaxPhysSize(dst.iAddr, c);
-			__KTRACE_OPT(KDMA, Kern::Printf("c = MaxPhysSize(dst.iAddr, c) = %d", c));
-			}
-
-		// SRC & DST
-		if ((mem_src || mem_dst) && (c < aCount) && (c > max_aligned_len))
-			{
-			// This is not the last fragment of a transfer to/from memory.
-			// We must round down the fragment size so the next one is
-			// correctly aligned.
-			c = max_aligned_len;
-			__KTRACE_OPT(KDMA, Kern::Printf("c = max_aligned_len = %d", c));
-			//
-			// But can this condition actually occur if src and dst are
-			// properly aligned to start with?
-			//
-			// If we disallow unequal alignment requirements in connection with
-			// non-contiguous memory buffers (see the long comment above in
-			// this function for why) and if both target addresses are
-			// correctly aligned at the beginning of the transfer then it
-			// doesn't seem possible to end up with a fragment which is not
-			// quite the total remaining size (c < aCount) but still larger
-			// than the greatest aligned length (c > max_aligned_len).
-			//
-			// That's because address alignment values are always a power of
-			// two (at least that's what we assume - otherwise
-			// AddressAlignMask() doesn't work), and memory page sizes are also
-			// always a power of two and hence a multiple of the alignment
-			// value (as long as the alignment is not greater than the page
-			// size, which seems a reasonable assumption regardless of the
-			// actual page size). So if we start properly aligned anywhere in a
-			// memory page then the number of bytes to the end of that page is
-			// always a multiple of the aligment value - there's no remainder.
-			//
-			// So let's see if we ever hit this assertion:
-			Kern::Printf("Unexpected: (mem_src || mem_dst) && (c < aCount) && (c > max_aligned_len)");
-			__DMA_ASSERTA(EFalse);
-			}
-
-		// If this is not the last fragment...
-		if (c < aCount)
-			{
-			const TUint es_src = src.iElementSize;
-			const TUint es_dst = dst.iElementSize;
-			const TUint fs_src = es_src * src.iElementsPerFrame;
-			const TUint fs_dst = es_dst * dst.iElementsPerFrame;
-			TUint c_prev;
-			do
-				{
-				c_prev = c;
-				// If fs_src is !0 then es_src must be !0 as well (see
-				// CheckTransferConfig).
-				if (es_src)
-					{
-					r = AdjustFragmentSize(c, es_src, fs_src);
-					if (r != KErrNone)
-						{
-						break;							// while (c != c_prev);
-						}
-					}
-				// If fs_dst is !0 then es_dst must be !0 as well (see
-				// CheckTransferConfig).
-				if (es_dst)
-					{
-					r = AdjustFragmentSize(c, es_dst, fs_dst);
-					if (r != KErrNone)
-						{
-						break;							// while (c != c_prev);
-						}
-					}
-				} while (c != c_prev);
-			if (r != KErrNone)
-				{
-				break;									 // while (aCount > 0);
-				}
-			}
-
-		// Set transfer count for the PSL
-		aTransferArgs.iTransferCount = c;
-		__KTRACE_OPT(KDMA, Kern::Printf("this fragm.: %d (0x%x) total remain.: %d (0x%x)",
-										c, c, aCount, aCount));
-		// Initialise fragment
-		r = iChannel.iController->InitDes(*iLastHdr, aTransferArgs);
-		if (r != KErrNone)
-			{
-			break;
-			}
-		// Update for next iteration
-		aCount -= c;
-		if (mem_src)
-			{
-			src.iAddr += c;
-			}
-		if (mem_dst)
-			{
-			dst.iAddr += c;
-			}
-		} while (aCount > 0);
-
-	if (r != KErrNone)
-		{
-		FreeDesList();
-		}
-	return r;
-	}
-
-
-TInt DDmaRequest::FragAsym(TDmaTransferArgs& aTransferArgs, TUint aCount,
-						   TUint aMaxTransferLen)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::FragAsym"));
-
-	TInt r;
-	if (iChannel.iDmacCaps->iBalancedAsymSegments)
-		{
-		r = FragBalancedAsym(aTransferArgs, aCount, aMaxTransferLen);
-		if (r != KErrNone)
-			{
-			FreeSrcDesList();
-			FreeDstDesList();
-			}
-		return r;
-		}
-	r = FragAsymSrc(aTransferArgs, aCount, aMaxTransferLen);
-	if (r != KErrNone)
-		{
-		FreeSrcDesList();
-		return r;
-		}
-	r = FragAsymDst(aTransferArgs, aCount, aMaxTransferLen);
-	if (r != KErrNone)
-		{
-		FreeSrcDesList();
-		FreeDstDesList();
-		}
-	return r;
-	}
-
-
-TInt DDmaRequest::FragAsymSrc(TDmaTransferArgs& aTransferArgs, TUint aCount,
-							  TUint aMaxTransferLen)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::FragAsymSrc"));
-
-	TDmaTransferConfig& src = aTransferArgs.iSrcConfig;
-	const TBool mem_src = (src.iFlags & KDmaMemAddr);
-
-	const TUint align_mask = iChannel.AddressAlignMask(src.iFlags,
-													   src.iElementSize,
-													   aTransferArgs.iPslRequestInfo);
-	__KTRACE_OPT(KDMA, Kern::Printf("align_mask: 0x%x", align_mask));
-
-	// Memory buffers must satisfy alignment constraint
-	__DMA_ASSERTD(!mem_src || ((src.iAddr & align_mask) == 0));
-
-	// Max aligned length is used to make sure the beginnings of subtransfers
-	// (i.e. fragments) are correctly aligned.
-	const TUint max_aligned_len = (aMaxTransferLen & ~align_mask);
-	__KTRACE_OPT(KDMA, Kern::Printf("max_aligned_len: %d", max_aligned_len));
-	// Client and PSL sane?
-	__DMA_ASSERTD(max_aligned_len > 0);
-
-	TInt r;
-	// Revert any previous fragmentation attempt
-	FreeSrcDesList();
-	do
-		{
-		// Allocate fragment
-		r = ExpandSrcDesList(/*1*/);
-		if (r != KErrNone)
-			{
-			break;
-			}
-		// Compute fragment size
-		TUint c = _Min(aMaxTransferLen, aCount);
-		__KTRACE_OPT(KDMA, Kern::Printf("c = _Min(aMaxTransferLen, aCount) = %d", c));
-
-		if (mem_src && !(src.iFlags & KDmaMemIsContiguous))
-			{
-			c = MaxPhysSize(src.iAddr, c);
-			__KTRACE_OPT(KDMA, Kern::Printf("c = MaxPhysSize(src.iAddr, c) = %d", c));
-			}
-
-		if (mem_src && (c < aCount) && (c > max_aligned_len))
-			{
-			// This is not the last fragment of a transfer from memory.
-			// We must round down the fragment size so the next one is
-			// correctly aligned.
-			__KTRACE_OPT(KDMA, Kern::Printf("c = max_aligned_len = %d", c));
-			//
-			// But can this condition actually occur if src is properly aligned
-			// to start with?
-			//
-			// If the target address is correctly aligned at the beginning of
-			// the transfer then it doesn't seem possible to end up with a
-			// fragment which is not quite the total remaining size (c <
-			// aCount) but still larger than the greatest aligned length (c >
-			// max_aligned_len).
-			//
-			// That's because address alignment values are always a power of
-			// two (at least that's what we assume - otherwise
-			// AddressAlignMask() doesn't work), and memory page sizes are also
-			// always a power of two and hence a multiple of the alignment
-			// value (as long as the alignment is not greater than the page
-			// size, which seems a reasonable assumption regardless of the
-			// actual page size). So if we start properly aligned anywhere in a
-			// memory page then the number of bytes to the end of that page is
-			// always a multiple of the aligment value - there's no remainder.
-			//
-			// So let's see if we ever hit this assertion:
-			Kern::Printf("Unexpected: mem_src && (c < aCount) && (c > max_aligned_len)");
-			__DMA_ASSERTA(EFalse);
-			}
-
-		// If this is not the last fragment...
-		if (c < aCount)
-			{
-			const TUint es = src.iElementSize;
-			const TUint fs = es * src.iElementsPerFrame;
-			// If fs is !0 then es must be !0 as well (see
-			// CheckTransferConfig).
-			if (es)
-				{
-				r = AdjustFragmentSize(c, es, fs);
-				if (r != KErrNone)
-					{
-					break;								 // while (aCount > 0);
-					}
-				}
-			}
-
-		// Set transfer count for the PSL
-		aTransferArgs.iTransferCount = c;
-		__KTRACE_OPT(KDMA, Kern::Printf("this fragm.: %d (0x%x) total remain.: %d (0x%x)",
-										c, c, aCount, aCount));
-		// Initialise fragment
-		r = iChannel.iController->InitSrcHwDes(*iSrcLastHdr, aTransferArgs);
-		if (r != KErrNone)
-			{
-			break;
-			}
-		// Update for next iteration
-		aCount -= c;
-		if (mem_src)
-			{
-			src.iAddr += c;
-			}
-		} while (aCount > 0);
-
-	return r;
-	}
-
-
-TInt DDmaRequest::FragAsymDst(TDmaTransferArgs& aTransferArgs, TUint aCount,
-							  TUint aMaxTransferLen)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::FragAsymDst"));
-
-	TDmaTransferConfig& dst = aTransferArgs.iDstConfig;
-	const TBool mem_dst = (dst.iFlags & KDmaMemAddr);
-
-	const TUint align_mask = iChannel.AddressAlignMask(dst.iFlags,
-													   dst.iElementSize,
-													   aTransferArgs.iPslRequestInfo);
-	__KTRACE_OPT(KDMA, Kern::Printf("align_mask: 0x%x", align_mask));
-
-	// Memory buffers must satisfy alignment constraint
-	__DMA_ASSERTD(!mem_dst || ((dst.iAddr & align_mask) == 0));
-
-	// Max aligned length is used to make sure the beginnings of subtransfers
-	// (i.e. fragments) are correctly aligned.
-	const TUint max_aligned_len = (aMaxTransferLen & ~align_mask);
-	__KTRACE_OPT(KDMA, Kern::Printf("max_aligned_len: %d", max_aligned_len));
-	// Client and PSL sane?
-	__DMA_ASSERTD(max_aligned_len > 0);
-
-	TInt r;
-	// Revert any previous fragmentation attempt
-	FreeDstDesList();
-	do
-		{
-		// Allocate fragment
-		r = ExpandDstDesList(/*1*/);
-		if (r != KErrNone)
-			{
-			break;
-			}
-		// Compute fragment size
-		TUint c = _Min(aMaxTransferLen, aCount);
-		__KTRACE_OPT(KDMA, Kern::Printf("c = _Min(aMaxTransferLen, aCount) = %d", c));
-
-		if (mem_dst && !(dst.iFlags & KDmaMemIsContiguous))
-			{
-			c = MaxPhysSize(dst.iAddr, c);
-			__KTRACE_OPT(KDMA, Kern::Printf("c = MaxPhysSize(dst.iAddr, c) = %d", c));
-			}
-
-		if (mem_dst && (c < aCount) && (c > max_aligned_len))
-			{
-			// This is not the last fragment of a transfer to memory.
-			// We must round down the fragment size so the next one is
-			// correctly aligned.
-			__KTRACE_OPT(KDMA, Kern::Printf("c = max_aligned_len = %d", c));
-			//
-			// But can this condition actually occur if dst is properly aligned
-			// to start with?
-			//
-			// If the target address is correctly aligned at the beginning of
-			// the transfer then it doesn't seem possible to end up with a
-			// fragment which is not quite the total remaining size (c <
-			// aCount) but still larger than the greatest aligned length (c >
-			// max_aligned_len).
-			//
-			// That's because address alignment values are always a power of
-			// two (at least that's what we assume - otherwise
-			// AddressAlignMask() doesn't work), and memory page sizes are also
-			// always a power of two and hence a multiple of the alignment
-			// value (as long as the alignment is not greater than the page
-			// size, which seems a reasonable assumption regardless of the
-			// actual page size). So if we start properly aligned anywhere in a
-			// memory page then the number of bytes to the end of that page is
-			// always a multiple of the aligment value - there's no remainder.
-			//
-			// So let's see if we ever hit this assertion:
-			Kern::Printf("Unexpected: mem_dst && (c < aCount) && (c > max_aligned_len)");
-			__DMA_ASSERTA(EFalse);
-			}
-
-		// If this is not the last fragment...
-		if (c < aCount)
-			{
-			const TUint es = dst.iElementSize;
-			const TUint fs = es * dst.iElementsPerFrame;
-			// If fs is !0 then es must be !0 as well (see
-			// CheckTransferConfig).
-			if (es)
-				{
-				r = AdjustFragmentSize(c, es, fs);
-				if (r != KErrNone)
-					{
-					break;								 // while (aCount > 0);
-					}
-				}
-			}
-
-		// Set transfer count for the PSL
-		aTransferArgs.iTransferCount = c;
-		__KTRACE_OPT(KDMA, Kern::Printf("this fragm.: %d (0x%x) total remain.: %d (0x%x)",
-										c, c, aCount, aCount));
-		// Initialise fragment
-		r = iChannel.iController->InitDstHwDes(*iDstLastHdr, aTransferArgs);
-		if (r != KErrNone)
-			{
-			break;
-			}
-		// Update for next iteration
-		aCount -= c;
-		if (mem_dst)
-			{
-			dst.iAddr += c;
-			}
-		}
-	while (aCount > 0);
-
-	return r;
-	}
-
-
-TInt DDmaRequest::FragBalancedAsym(TDmaTransferArgs& aTransferArgs, TUint aCount,
-								   TUint aMaxTransferLen)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::FragBalancedAsym"));
-
-	TDmaTransferConfig& src = aTransferArgs.iSrcConfig;
-	TDmaTransferConfig& dst = aTransferArgs.iDstConfig;
-	const TBool mem_src = (src.iFlags & KDmaMemAddr);
-	const TBool mem_dst = (dst.iFlags & KDmaMemAddr);
-
-	const TUint align_mask_src = iChannel.AddressAlignMask(src.iFlags,
-														   src.iElementSize,
-														   aTransferArgs.iPslRequestInfo);
-	__KTRACE_OPT(KDMA, Kern::Printf("align_mask_src: 0x%x", align_mask_src));
-	const TUint align_mask_dst = iChannel.AddressAlignMask(dst.iFlags,
-														   dst.iElementSize,
-														   aTransferArgs.iPslRequestInfo);
-	__KTRACE_OPT(KDMA, Kern::Printf("align_mask_dst: 0x%x", align_mask_dst));
-
-	// Memory buffers must satisfy alignment constraint
-	__DMA_ASSERTD(!mem_src || ((src.iAddr & align_mask_src) == 0));
-	__DMA_ASSERTD(!mem_dst || ((dst.iAddr & align_mask_dst) == 0));
-
-	// Max aligned length is used to make sure the beginnings of subtransfers
-	// (i.e. fragments) are correctly aligned.
-	const TUint max_aligned_len = (aMaxTransferLen &
-								   ~(_Max(align_mask_src, align_mask_dst)));
-	__KTRACE_OPT(KDMA, Kern::Printf("max_aligned_len: %d", max_aligned_len));
-	// Client and PSL sane?
-	__DMA_ASSERTD(max_aligned_len > 0);
-
-	if (mem_src && mem_dst &&
-		align_mask_src && align_mask_dst &&
-		(align_mask_src != align_mask_dst) &&
-		(!(src.iFlags & KDmaMemIsContiguous) || !(dst.iFlags & KDmaMemIsContiguous)))
-		{
-		// We don't support transfers which satisfy ALL of the following conditions:
-		// 1) from memory to memory,
-		// 2) both sides have address alignment requirements,
-		// 3) those alignment requirements are not the same,
-		// 4) the memory is non-contiguous on at least one end.
-		//
-		// [A 5th condition is that the channel doesn't support fully
-		// asymmetric h/w descriptor lists,
-		// i.e. TDmaChannel::DmacCaps::iAsymHwDescriptors is reported as EFalse
-		// or iBalancedAsymSegments as ETrue. Hence this check is done in
-		// FragSym() and FragBalancedAsym() but not in FragAsym().]
-		//
-		// The reason for this is that fragmentation could be impossible. The
-		// memory layout (page break) on the side with the less stringent
-		// alignment requirement can result in a misaligned target address on
-		// the other side.
-		//
-		// Here is an example:
-		//
-		// src.iAddr =  3964 (0x0F7C), non-contiguous,
-		// align_mask_src = 1 (alignment = 2 bytes)
-		// dst.iAddr = 16384 (0x4000), contiguous,
-		// align_mask_dst = 7 (alignment = 8 bytes)
-		// count = max_xfer_len = 135 bytes
-		// => max_aligned_len = 128 bytes
-		//
-		// Now, suppose MaxPhysSize() returns 132 bytes because src has 132
-		// contiguous bytes to the end of its current mem page.
-		// Trying to fragment this leads to:
-		//
-		// frag_1 = 128 bytes: src reads from 3964 (0x0F7C),
-		//                     dst writes to 16384 (0x4000).
-		// (Fragment 1 uses the max_aligned_len instead of 132 bytes because
-		// otherwise the next fragment would start for the destination at
-		// dst.iAddr + 132 = 16516 (0x4084), which is not 8-byte aligned.)
-		//
-		// frag_2 = 4 bytes: src reads from 4092 (0x0FFC),
-		//                   dst writes to 16512 (0x4080).
-		// (Fragment 2 uses just 4 bytes instead of the remaining 7 bytes
-		// because there is a memory page break on the source side after 4 bytes.)
-		//
-		// frag_3 = 3 bytes: src reads from 4096 (0x1000),
-		//                   dst writes to 16516 (0x4084).
-		//
-		// And there's the problem: the start address of frag_3 is going to be
-		// misaligned for the destination side - it's not 8-byte aligned!
-		//
-		__KTRACE_OPT(KPANIC, Kern::Printf("Error: Different alignments for src & dst"
-										  " + non-contiguous target(s)"));
-		return KErrArgument;
-		}
-
-	TInt r;
-	// Revert any previous fragmentation attempt
-	FreeSrcDesList();
-	FreeDstDesList();
-	__DMA_ASSERTD(iSrcDesCount == iDstDesCount);
-	do
-		{
-		// Allocate fragment
-		r = ExpandSrcDesList(/*1*/);
-		if (r != KErrNone)
-			{
-			break;
-			}
-		r = ExpandDstDesList(/*1*/);
-		if (r != KErrNone)
-			{
-			break;
-			}
-		__DMA_ASSERTD(iSrcDesCount == iDstDesCount);
-		// Compute fragment size
-		TUint c = _Min(aMaxTransferLen, aCount);
-		__KTRACE_OPT(KDMA, Kern::Printf("c = _Min(aMaxTransferLen, aCount) = %d", c));
-
-		// SRC
-		if (mem_src && !(src.iFlags & KDmaMemIsContiguous))
-			{
-			c = MaxPhysSize(src.iAddr, c);
-			__KTRACE_OPT(KDMA, Kern::Printf("c = MaxPhysSize(src.iAddr, c) = %d", c));
-			}
-
-		// DST
-		if (mem_dst && !(dst.iFlags & KDmaMemIsContiguous))
-			{
-			c = MaxPhysSize(dst.iAddr, c);
-			__KTRACE_OPT(KDMA, Kern::Printf("c = MaxPhysSize(dst.iAddr, c) = %d", c));
-			}
-
-		// SRC & DST
-		if ((mem_src || mem_dst) && (c < aCount) && (c > max_aligned_len))
-			{
-			// This is not the last fragment of a transfer to/from memory.
-			// We must round down the fragment size so the next one is
-			// correctly aligned.
-			c = max_aligned_len;
-			__KTRACE_OPT(KDMA, Kern::Printf("c = max_aligned_len = %d", c));
-			//
-			// But can this condition actually occur if src and dst are
-			// properly aligned to start with?
-			//
-			// If we disallow unequal alignment requirements in connection with
-			// non-contiguous memory buffers (see the long comment above in
-			// this function for why) and if both target addresses are
-			// correctly aligned at the beginning of the transfer then it
-			// doesn't seem possible to end up with a fragment which is not
-			// quite the total remaining size (c < aCount) but still larger
-			// than the greatest aligned length (c > max_aligned_len).
-			//
-			// That's because address alignment values are always a power of
-			// two (at least that's what we assume - otherwise
-			// AddressAlignMask() doesn't work), and memory page sizes are also
-			// always a power of two and hence a multiple of the alignment
-			// value (as long as the alignment is not greater than the page
-			// size, which seems a reasonable assumption regardless of the
-			// actual page size). So if we start properly aligned anywhere in a
-			// memory page then the number of bytes to the end of that page is
-			// always a multiple of the aligment value - there's no remainder.
-			//
-			// So let's see if we ever hit this assertion:
-			Kern::Printf("Unexpected: (mem_src || mem_dst) && (c < aCount) && (c > max_aligned_len)");
-			__DMA_ASSERTA(EFalse);
-			}
-
-		// If this is not the last fragment...
-		if (c < aCount)
-			{
-			const TUint es_src = src.iElementSize;
-			const TUint es_dst = dst.iElementSize;
-			const TUint fs_src = es_src * src.iElementsPerFrame;
-			const TUint fs_dst = es_dst * dst.iElementsPerFrame;
-			TUint c_prev;
-			do
-				{
-				c_prev = c;
-				// If fs_src is !0 then es_src must be !0 as well (see
-				// CheckTransferConfig).
-				if (es_src)
-					{
-					r = AdjustFragmentSize(c, es_src, fs_src);
-					if (r != KErrNone)
-						{
-						break;							// while (c != c_prev);
-						}
-					}
-				// If fs_dst is !0 then es_dst must be !0 as well (see
-				// CheckTransferConfig).
-				if (es_dst)
-					{
-					r = AdjustFragmentSize(c, es_dst, fs_dst);
-					if (r != KErrNone)
-						{
-						break;							// while (c != c_prev);
-						}
-					}
-				} while (c != c_prev);
-			if (r != KErrNone)
-				{
-				break;									 // while (aCount > 0);
-				}
-			}
-
-		// Set transfer count for the PSL
-		aTransferArgs.iTransferCount = c;
-		__KTRACE_OPT(KDMA, Kern::Printf("this fragm.: %d (0x%x) total remain.: %d (0x%x)",
-										c, c, aCount, aCount));
-		// Initialise SRC fragment
-		r = iChannel.iController->InitSrcHwDes(*iSrcLastHdr, aTransferArgs);
-		if (r != KErrNone)
-			{
-			break;
-			}
-		// Initialise DST fragment
-		r = iChannel.iController->InitDstHwDes(*iDstLastHdr, aTransferArgs);
-		if (r != KErrNone)
-			{
-			break;
-			}
-		// Update for next iteration
-		aCount -= c;
-		if (mem_src)
-			{
-			src.iAddr += c;
-			}
-		if (mem_dst)
-			{
-			dst.iAddr += c;
-			}
-		}
-	while (aCount > 0);
-
-	return r;
-	}
-
-
-EXPORT_C TInt DDmaRequest::Queue()
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::Queue thread %O", &Kern::CurrentThread()));
-	// Not configured? Call Fragment() first!
-	if (iChannel.iDmacCaps->iAsymHwDescriptors)
-		{
-		__DMA_ASSERTD((iSrcDesCount > 0) && (iDstDesCount > 0));
-		}
-	else
-		{
-		__DMA_ASSERTD(iDesCount > 0);
-		}
-	__DMA_ASSERTD(!iQueued);
-
-	// Append request to queue and link new descriptor list to existing one.
-	iChannel.Wait();
-
-	TUint32 req_count = iChannel.iQueuedRequests++;
-	if (iChannel.iCallQueuedRequestFn)
-		{
-		if (req_count == 0)
-			{
-			iChannel.Signal();
-			iChannel.QueuedRequestCountChanged();
-			iChannel.Wait();
-			}
-		}
-
-	TInt r = KErrGeneral;
-	const TBool ch_isr_cb = __e32_atomic_load_acq32(&iChannel.iIsrCbRequest);
-	if (ch_isr_cb)
-		{
-		// Client mustn't try to queue any new request while one with an ISR
-		// callback is already queued on this channel. This is to make sure
-		// that the channel's Transfer() function is not called by both the ISR
-		// and the client thread at the same time.
-		__KTRACE_OPT(KPANIC, Kern::Printf("An ISR cb request exists - not queueing"));
-		// Undo the request count increment...
-		req_count = --iChannel.iQueuedRequests;
-		__DMA_INVARIANT();
-		iChannel.Signal();
-		if (iChannel.iCallQueuedRequestFn)
-			{
-			if (req_count == 0)
-				{
-				iChannel.QueuedRequestCountChanged();
-				}
-			}
-		}
-	else if (iIsrCb && !iChannel.IsQueueEmpty())
-		{
-		// Client mustn't try to queue an ISR callback request whilst any
-		// others are still queued on this channel. This is to make sure that
-		// the ISR callback doesn't get executed together with the DFC(s) of
-		// any previous request(s).
-		__KTRACE_OPT(KPANIC, Kern::Printf("Request queue not empty - not queueing"));
-		// Undo the request count increment...
-		req_count = --iChannel.iQueuedRequests;
-		__DMA_INVARIANT();
-		iChannel.Signal();
-		if (iChannel.iCallQueuedRequestFn)
-			{
-			if (req_count == 0)
-				{
-				iChannel.QueuedRequestCountChanged();
-				}
-			}
-		}
-	else if (iChannel.iIsrDfc & (TUint32)TDmaChannel::KCancelFlagMask)
-		{
-		__KTRACE_OPT(KPANIC, Kern::Printf("Channel requests cancelled - not queueing"));
-		// Someone is cancelling all requests - undo the request count increment...
-		req_count = --iChannel.iQueuedRequests;
-		__DMA_INVARIANT();
-		iChannel.Signal();
-		if (iChannel.iCallQueuedRequestFn)
-			{
-			if (req_count == 0)
-				{
-				iChannel.QueuedRequestCountChanged();
-				}
-			}
-		}
-	else
-		{
-		iQueued = ETrue;
-		iChannel.iReqQ.Add(&iLink);
-		iChannel.SetNullPtr(*this);
-		if (iIsrCb)
-			{
-			// Since we've made sure that there is no other request in the
-			// queue before this, the only thing of relevance is the channel
-			// DFC which might yet have to complete for the previous request,
-			// and this function might indeed have been called from there via
-			// the client callback. This should be all right though as once
-			// we've set the following flag no further Queue()'s will be
-			// possible.
-			__e32_atomic_store_rel32(&iChannel.iIsrCbRequest, ETrue);
-			}
-		iChannel.DoQueue(*this);
-		r = KErrNone;
-		__DMA_INVARIANT();
-		iChannel.Signal();
-		}
-
-	return r;
-	}
-
-
-EXPORT_C TInt DDmaRequest::ExpandDesList(TInt aCount)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::ExpandDesList aCount=%d", aCount));
-	return ExpandDesList(aCount, iDesCount, iFirstHdr, iLastHdr);
-	}
-
-
-EXPORT_C TInt DDmaRequest::ExpandSrcDesList(TInt aCount)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::ExpandSrcDesList"));
-	return ExpandDesList(aCount, iSrcDesCount, iSrcFirstHdr, iSrcLastHdr);
-	}
-
-
-EXPORT_C TInt DDmaRequest::ExpandDstDesList(TInt aCount)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::ExpandDstDesList"));
-	return ExpandDesList(aCount, iDstDesCount, iDstFirstHdr, iDstLastHdr);
-	}
-
-
-TInt DDmaRequest::ExpandDesList(TInt aCount, TInt& aDesCount,
-								SDmaDesHdr*& aFirstHdr,
-								SDmaDesHdr*& aLastHdr)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::ExpandDesList"));
-	__DMA_ASSERTD(!iQueued);
-	__DMA_ASSERTD(aCount > 0);
-
-	if (aCount > iChannel.iAvailDesCount)
-		{
-		return KErrTooBig;
-		}
-
-	iChannel.iAvailDesCount -= aCount;
-	aDesCount += aCount;
-
-	TDmac& c = *(iChannel.iController);
-	c.Wait();
-
-	if (aFirstHdr == NULL)
-		{
-		// Handle an empty list specially to simplify the following loop
-		aFirstHdr = aLastHdr = c.iFreeHdr;
-		c.iFreeHdr = c.iFreeHdr->iNext;
-		--aCount;
-		}
-	else
-		{
-		aLastHdr->iNext = c.iFreeHdr;
-		}
-
-	// Remove as many descriptors and headers from the free pool as necessary
-	// and ensure hardware descriptors are chained together.
-	while (aCount-- > 0)
-		{
-		__DMA_ASSERTD(c.iFreeHdr != NULL);
-		if (c.iCapsHwDes)
-			{
-			c.ChainHwDes(*aLastHdr, *(c.iFreeHdr));
-			}
-		aLastHdr = c.iFreeHdr;
-		c.iFreeHdr = c.iFreeHdr->iNext;
-		}
-
-	c.Signal();
-
-	aLastHdr->iNext = NULL;
-
-	__DMA_INVARIANT();
-	return KErrNone;
-	}
-
-
-EXPORT_C void DDmaRequest::FreeDesList()
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::FreeDesList"));
-	FreeDesList(iDesCount, iFirstHdr, iLastHdr);
-	}
-
-
-EXPORT_C void DDmaRequest::FreeSrcDesList()
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::FreeSrcDesList"));
-	FreeDesList(iSrcDesCount, iSrcFirstHdr, iSrcLastHdr);
-	}
-
-
-EXPORT_C void DDmaRequest::FreeDstDesList()
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::FreeDstDesList"));
-	FreeDesList(iDstDesCount, iDstFirstHdr, iDstLastHdr);
-	}
-
-
-void DDmaRequest::FreeDesList(TInt& aDesCount, SDmaDesHdr*& aFirstHdr, SDmaDesHdr*& aLastHdr)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::FreeDesList count=%d", aDesCount));
-	__DMA_ASSERTD(!iQueued);
-
-	if (aDesCount > 0)
-		{
-		iChannel.iAvailDesCount += aDesCount;
-		TDmac& c = *(iChannel.iController);
-		const SDmaDesHdr* hdr = aFirstHdr;
-		while (hdr)
-			{
-			__DMA_ASSERTD(c.IsValidHdr(hdr));
-
-			// This (potential) PSL call doesn't follow the "overhead
-			// principle", and something should be done about this.
-			c.ClearHwDes(*hdr);
-			hdr = hdr->iNext;
-			};
-
-		c.Wait();
-		__DMA_ASSERTD(c.IsValidHdr(c.iFreeHdr));
-		aLastHdr->iNext = c.iFreeHdr;
-		c.iFreeHdr = aFirstHdr;
-		c.Signal();
-
-		aFirstHdr = aLastHdr = NULL;
-		aDesCount = 0;
-		}
-	}
-
-
-EXPORT_C void DDmaRequest::EnableSrcElementCounting(TBool /*aResetElementCount*/)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::EnableSrcElementCounting"));
-
-	// Not yet implemented.
-	return;
-	}
-
-
-EXPORT_C void DDmaRequest::EnableDstElementCounting(TBool /*aResetElementCount*/)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::EnableDstElementCounting"));
-
-	// Not yet implemented.
-	return;
-	}
-
-
-EXPORT_C void DDmaRequest::DisableSrcElementCounting()
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::DisableSrcElementCounting"));
-
-	// Not yet implemented.
-	return;
-	}
-
-
-EXPORT_C void DDmaRequest::DisableDstElementCounting()
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::DisableDstElementCounting"));
-
-	// Not yet implemented.
-	return;
-	}
-
-
-EXPORT_C TUint32 DDmaRequest::TotalNumSrcElementsTransferred()
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::TotalNumSrcElementsTransferred"));
-
-	// Not yet implemented.
-	return iTotalNumSrcElementsTransferred;
-	}
-
-
-EXPORT_C TUint32 DDmaRequest::TotalNumDstElementsTransferred()
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::TotalNumDstElementsTransferred"));
-
-	// Not yet implemented.
-	return iTotalNumDstElementsTransferred;
-	}
-
-
-EXPORT_C TInt DDmaRequest::FragmentCount()
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::FragmentCount"));
-	return FragmentCount(iFirstHdr);
-	}
-
-
-EXPORT_C TInt DDmaRequest::SrcFragmentCount()
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::SrcFragmentCount"));
-	return FragmentCount(iSrcFirstHdr);
-	}
-
-
-EXPORT_C TInt DDmaRequest::DstFragmentCount()
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::DstFragmentCount"));
-	return FragmentCount(iDstFirstHdr);
-	}
-
-
-TInt DDmaRequest::FragmentCount(const SDmaDesHdr* aHdr)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("DDmaRequest::FragmentCount aHdr=0x%08x", aHdr));
-	TInt count = 0;
-	for (const SDmaDesHdr* pH = aHdr; pH != NULL; pH = pH->iNext)
-		{
-		count++;
-		}
-	return count;
-	}
-
-
-//
-// Called when request is removed from request queue in channel
-//
-inline void DDmaRequest::OnDeque()
-	{
-	iQueued = EFalse;
-	if (iChannel.iDmacCaps->iAsymHwDescriptors)
-		{
-		iSrcLastHdr->iNext = NULL;
-		iDstLastHdr->iNext = NULL;
-		iChannel.DoUnlink(*iSrcLastHdr);
-		iChannel.DoUnlink(*iDstLastHdr);
-		}
-	else
-		{
-		iLastHdr->iNext = NULL;
-		iChannel.DoUnlink(*iLastHdr);
-		}
-	}
-
-
-#ifdef _DEBUG
-void DDmaRequest::Invariant()
-	{
-	// This invariant may be called either with,
-	// or without the channel lock already held
-	TBool channelLockAquired=EFalse;
-	if(!iChannel.iLock.HeldByCurrentThread())
-		{
-		iChannel.Wait();
-		channelLockAquired = ETrue;
-		}
-
-	__DMA_ASSERTD(LOGICAL_XOR(iCb, iDmaCb));
-	if (iChannel.iDmacCaps->iAsymHwDescriptors)
-		{
-		__DMA_ASSERTD((0 <= iSrcDesCount) && (iSrcDesCount <= iChannel.iMaxDesCount) &&
-					  (0 <= iDstDesCount) && (iDstDesCount <= iChannel.iMaxDesCount));
-		if (iSrcDesCount == 0)
-			{
-			// Not fragmented yet
-			__DMA_ASSERTD(iDstDesCount == 0);
-			__DMA_ASSERTD(!iQueued);
-			__DMA_ASSERTD(!iSrcFirstHdr && !iSrcLastHdr &&
-						  !iDstFirstHdr && !iDstLastHdr);
-			}
-		else if (iDstDesCount == 0)
-			{
-			// Src side only fragmented yet
-			__DMA_ASSERTD(iChannel.iController->IsValidHdr(iSrcFirstHdr));
-			__DMA_ASSERTD(iChannel.iController->IsValidHdr(iSrcLastHdr));
-			}
-		else
-			{
-			// Src & Dst sides fragmented
-			__DMA_ASSERTD(iChannel.iController->IsValidHdr(iSrcFirstHdr));
-			__DMA_ASSERTD(iChannel.iController->IsValidHdr(iSrcLastHdr));
-			__DMA_ASSERTD(iChannel.iController->IsValidHdr(iDstFirstHdr));
-			__DMA_ASSERTD(iChannel.iController->IsValidHdr(iDstLastHdr));
-			}
-		}
-	else
-		{
-		__DMA_ASSERTD((0 <= iDesCount) && (iDesCount <= iChannel.iMaxDesCount));
-		if (iDesCount == 0)
-			{
-			__DMA_ASSERTD(!iQueued);
-			__DMA_ASSERTD(!iFirstHdr && !iLastHdr);
-			}
-		else
-			{
-			__DMA_ASSERTD(iChannel.iController->IsValidHdr(iFirstHdr));
-			__DMA_ASSERTD(iChannel.iController->IsValidHdr(iLastHdr));
-			}
-		}
-
-	if(channelLockAquired)
-			{
-			iChannel.Signal();
-			}
-	}
-#endif
-
-
-//////////////////////////////////////////////////////////////////////////////
-// TDmaChannel
-
-TDmaChannel::TDmaChannel()
-	: iController(NULL),
-	  iDmacCaps(NULL),
-	  iPslId(0),
-	  iDynChannel(EFalse),
-	  iPriority(KDmaPriorityNone),
-	  iCurHdr(NULL),
-	  iNullPtr(&iCurHdr),
-	  iDfc(Dfc, NULL, 0),
-	  iMaxDesCount(0),
-	  iAvailDesCount(0),
-	  iIsrDfc(0),
-	  iReqQ(),
-	  iReqCount(0),
-	  iQueuedRequests(0),
-	  iCallQueuedRequestFn(ETrue),
-	  iCancelInfo(NULL),
-	  iRedoRequest(EFalse),
-	  iIsrCbRequest(EFalse)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("TDmaChannel::TDmaChannel =0x%08X", this));
-	__DMA_INVARIANT();
-	}
-
-
-//
-// static member function
-//
-EXPORT_C TInt TDmaChannel::Open(const SCreateInfo& aInfo, TDmaChannel*& aChannel)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("TDmaChannel::Open thread %O", &Kern::CurrentThread()));
-
-	if (aInfo.iDesCount < 1)
-		{
-		__KTRACE_OPT(KPANIC, Kern::Printf("DMA channel failed to open: iDescount<1"));
-		return KErrArgument;
-		}
-
-	__DMA_ASSERTD(aInfo.iPriority <= KDmaPriority8);
-	__DMA_ASSERTD(aInfo.iDfcQ != NULL);
-	__DMA_ASSERTD(aInfo.iDfcPriority < KNumDfcPriorities);
-
-	aChannel = NULL;
-
-	DmaChannelMgr::Wait();
-	TDmaChannel* pC = DmaChannelMgr::Open(aInfo.iCookie, aInfo.iDynChannel, aInfo.iPriority);
-	DmaChannelMgr::Signal();
-	if (!pC)
-		{
-		return KErrInUse;
-		}
-	__DMA_ASSERTD(pC->iController != NULL);
-	__DMA_ASSERTD(pC->iDmacCaps != NULL);
-	__DMA_ASSERTD(pC->iController->iCapsHwDes == pC->DmacCaps().iHwDescriptors);
-	// PSL needs to set iDynChannel if and only if dynamic channel was requested
-	__DMA_ASSERTD(!LOGICAL_XOR(aInfo.iDynChannel, pC->iDynChannel));
-
-	const TInt r = pC->iController->ReserveSetOfDes(aInfo.iDesCount);
-	if (r != KErrNone)
-		{
-		pC->Close();
-		return r;
-		}
-	pC->iAvailDesCount = pC->iMaxDesCount = aInfo.iDesCount;
-
-	new (&pC->iDfc) TDfc(&Dfc, pC, aInfo.iDfcQ, aInfo.iDfcPriority);
-
-	aChannel = pC;
-
-#ifdef _DEBUG
-	pC->Invariant();
-#endif
-	__KTRACE_OPT(KDMA, Kern::Printf("opened channel %d", pC->iPslId));
-	return KErrNone;
-	}
-
-
-EXPORT_C void TDmaChannel::Close()
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("TDmaChannel::Close %d iReqCount=%d", iPslId, iReqCount));
-	__DMA_ASSERTD(IsQueueEmpty());
-	__DMA_ASSERTD(iReqCount == 0);
-
-	__DMA_ASSERTD(iQueuedRequests == 0);
-
-	// Descriptor leak? -> bug in request code
-	__DMA_ASSERTD(iAvailDesCount == iMaxDesCount);
-
-	__DMA_ASSERTD(!iRedoRequest);
-	__DMA_ASSERTD(!iIsrCbRequest);
-
-	iController->ReleaseSetOfDes(iMaxDesCount);
-	iAvailDesCount = iMaxDesCount = 0;
-
-	DmaChannelMgr::Wait();
-	DmaChannelMgr::Close(this);
-	// The following assignment will be removed once IsOpened() has been
-	// removed. That's because 'this' shouldn't be touched any more once
-	// Close() has returned from the PSL.
-	iController = NULL;
-	DmaChannelMgr::Signal();
-	}
-
-
-EXPORT_C TInt TDmaChannel::LinkToChannel(TDmaChannel* aChannel)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("TDmaChannel::LinkToChannel thread %O",
-									&Kern::CurrentThread()));
-	if (aChannel)
-		{
-		return iController->LinkChannels(*this, *aChannel);
-		}
-	else
-		{
-		return iController->UnlinkChannel(*this);
-		}
-	}
-
-
-EXPORT_C TInt TDmaChannel::Pause()
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("TDmaChannel::Pause thread %O",
-									&Kern::CurrentThread()));
-	return iController->PauseTransfer(*this);
-	}
-
-
-EXPORT_C TInt TDmaChannel::Resume()
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("TDmaChannel::Resume thread %O",
-									&Kern::CurrentThread()));
-	return iController->ResumeTransfer(*this);
-	}
-
-
-EXPORT_C void TDmaChannel::CancelAll()
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("TDmaChannel::CancelAll thread %O channel - %d",
-									&Kern::CurrentThread(), iPslId));
-	NThread* const nt = NKern::CurrentThread();
-	TBool wait = EFalse;
-	TDmaCancelInfo cancelinfo;
-	TDmaCancelInfo* waiters = NULL;
-
-	NKern::ThreadEnterCS();
-	Wait();
-	const TUint32 req_count_before = iQueuedRequests;
-	NThreadBase* const dfc_nt = iDfc.Thread();
-	// Shouldn't be NULL (i.e. an IDFC)
-	__DMA_ASSERTD(dfc_nt);
-
-	__e32_atomic_store_ord32(&iIsrDfc, (TUint32)KCancelFlagMask);
-	// ISRs after this point will not post a DFC, however a DFC may already be
-	// queued or running or both.
-	if (!IsQueueEmpty())
-		{
-		// There is a transfer in progress. It may complete before the DMAC
-		// has stopped, but the resulting ISR will not post a DFC.
-		// ISR should not happen after this function returns.
-		iController->StopTransfer(*this);
-
-		DoCancelAll();
-		ResetNullPtr();
-
-		// Clean-up the request queue.
-		SDblQueLink* pL;
-		while ((pL = iReqQ.GetFirst()) != NULL)
-			{
-			iQueuedRequests--;
-			DDmaRequest* pR = _LOFF(pL, DDmaRequest, iLink);
-			pR->OnDeque();
-			}
-		}
-	if (dfc_nt == nt)
-		{
-		// DFC runs in this thread, so just cancel it and we're finished
-		iDfc.Cancel();
-
-		// If other calls to CancelAll() are waiting for the DFC, release them here
-		waiters = iCancelInfo;
-		iCancelInfo = NULL;
-
-		// Reset the ISR count
-		__e32_atomic_store_rel32(&iIsrDfc, 0);
-		}
-	else
-		{
-		// DFC runs in another thread. Make sure it's queued and then wait for it to run.
-		if (iCancelInfo)
-			{
-			// Insert cancelinfo into the list so that it precedes iCancelInfo
-			cancelinfo.InsertBefore(iCancelInfo);
-			}
-		else
-			{
-			iCancelInfo = &cancelinfo;
-			}
-		wait = ETrue;
-		iDfc.Enque();
-		}
-
-	const TUint32 req_count_after = iQueuedRequests;
-
-	Signal();
-
-	if (waiters)
-		{
-		waiters->Signal();
-		}
-	else if (wait)
-		{
-		NKern::FSWait(&cancelinfo.iSem);
-		}
-
- 	NKern::ThreadLeaveCS();
-
-	// Only call PSL if there were requests queued when we entered AND there
-	// are now no requests left on the queue.
-	if (iCallQueuedRequestFn)
-		{
-		if ((req_count_before != 0) && (req_count_after == 0))
-			{
-			QueuedRequestCountChanged();
-			}
-		}
-
-	__DMA_INVARIANT();
-	}
-
-
-EXPORT_C TInt TDmaChannel::IsrRedoRequest(TUint32 aSrcAddr, TUint32 aDstAddr,
-										  TUint aTransferCount,
-										  TUint32 aPslRequestInfo,
-										  TBool aIsrCb)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("TDmaChannel::IsrRedoRequest src=0x%08X, "
-									"dst=0x%08X, count=%d, pslInfo=0x%08X, isrCb=%d",
-									aSrcAddr, aDstAddr, aTransferCount, aPslRequestInfo,
-									aIsrCb));
-	// Function needs to be called in ISR context.
-	__DMA_ASSERTD(NKern::CurrentContext() == NKern::EInterrupt);
-
-	__DMA_ASSERTD(!iReqQ.IsEmpty());
-	__DMA_ASSERTD(iIsrCbRequest);
-
-#ifdef _DEBUG
-	if ((aSrcAddr != KPhysAddrInvalid) && (aSrcAddr == aDstAddr))
-		{
-		__KTRACE_OPT(KPANIC,
-					 Kern::Printf("Error: Updating src & dst to same address: 0x%08X",
-								  aSrcAddr));
-		return KErrArgument;
-		}
-#endif
-
-	// We assume here that the just completed request is the first one in the
-	// queue, i.e. that even if there is more than one request in the queue,
-	// their respective last and first (hw) descriptors are *not* linked.
-	// (Although that's what apparently happens in TDmaSgChannel::DoQueue() /
-	// TDmac::AppendHwDes() @@@).
-	DDmaRequest* const pCurReq = _LOFF(iReqQ.First(), DDmaRequest, iLink);
-	TInt r;
-
-	if (iDmacCaps->iAsymHwDescriptors)
-		{
-		// We don't allow multiple-descriptor chains to be updated here.
-		// That we just panic (instead of returning an error), and also only in
-		// the UDEB case (instead of always) is not ideal, but done here in the
-		// interest of performance.
-		__DMA_ASSERTD((pCurReq->iSrcDesCount == 1) && (pCurReq->iDstDesCount == 1));
-
-		// Adjust parameters if necessary (asymmetrical s/g variety)
-		const SDmaDesHdr* const pSrcFirstHdr = pCurReq->iSrcFirstHdr;
-		if ((aSrcAddr != KPhysAddrInvalid) || aTransferCount || aPslRequestInfo)
-			{
-			r = iController->UpdateSrcHwDes(*pSrcFirstHdr, aSrcAddr,
-											aTransferCount, aPslRequestInfo);
-			if (r != KErrNone)
-				{
-				__KTRACE_OPT(KPANIC, Kern::Printf("Src descriptor updating failed in PSL"));
-				return r;
-				}
-			}
-		const SDmaDesHdr* const pDstFirstHdr = pCurReq->iDstFirstHdr;
-		if ((aDstAddr != KPhysAddrInvalid) || aTransferCount || aPslRequestInfo)
-			{
-			r = iController->UpdateDstHwDes(*pDstFirstHdr, aSrcAddr,
-											aTransferCount, aPslRequestInfo);
-			if (r != KErrNone)
-				{
-				__KTRACE_OPT(KPANIC, Kern::Printf("Dst descriptor updating failed in PSL"));
-				return r;
-				}
-			}
-		// Reschedule the request
-		iController->Transfer(*this, *pSrcFirstHdr, *pDstFirstHdr);
-		}
-	else
-		{
-		// We don't allow a multiple-descriptor chain to be updated here.
-		// That we just panic (instead of returning an error), and also only in
-		// the UDEB case (instead of always) is not ideal, but done here in the
-		// interest of performance.
-		__DMA_ASSERTD(pCurReq->iDesCount == 1);
-
-		// Adjust parameters if necessary (symmetrical s/g and non-s/g variety)
-		const SDmaDesHdr* const pFirstHdr = pCurReq->iFirstHdr;
-		if ((aSrcAddr != KPhysAddrInvalid) || (aDstAddr != KPhysAddrInvalid) ||
-			aTransferCount || aPslRequestInfo)
-			{
-			r = iController->UpdateDes(*pFirstHdr, aSrcAddr, aDstAddr,
-									   aTransferCount, aPslRequestInfo);
-			if (r != KErrNone)
-				{
-				__KTRACE_OPT(KPANIC, Kern::Printf("Descriptor updating failed"));
-				return r;
-				}
-			}
-		// Reschedule the request
-		iController->Transfer(*this, *pFirstHdr);
-		}
-
-	if (!aIsrCb)
-		{
-		// Not another ISR callback please
-		pCurReq->iIsrCb = aIsrCb;
-		}
-	iRedoRequest = ETrue;
-
-	return KErrNone;
-	}
-
-
-EXPORT_C TInt TDmaChannel::FailNext(TInt /*aFragmentCount*/)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("TDmaChannel::FailNext"));
-	return iController->FailNext(*this);
-	}
-
-
-EXPORT_C TInt TDmaChannel::MissNextInterrupts(TInt aInterruptCount)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("TDmaChannel::MissNextInterrupts"));
-	return iController->MissNextInterrupts(*this, aInterruptCount);
-	}
-
-
-EXPORT_C TInt TDmaChannel::Extension(TInt aCmd, TAny* aArg)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("TDmaChannel::Extension"));
-	return iController->Extension(*this, aCmd, aArg);
-	}
-
-
-//
-// static member function
-//
-EXPORT_C TInt TDmaChannel::StaticExtension(TInt aCmd, TAny* aArg)
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("TDmaChannel::StaticExtension"));
-	return DmaChannelMgr::StaticExtension(aCmd, aArg);
-	}
-
-
-EXPORT_C TUint TDmaChannel::MaxTransferLength(TUint aSrcFlags, TUint aDstFlags,
-											  TUint32 aPslInfo)
-	{
-	return iController->MaxTransferLength(*this, aSrcFlags, aDstFlags, aPslInfo);
-	}
-
-
-EXPORT_C TUint TDmaChannel::AddressAlignMask(TUint aTargetFlags, TUint aElementSize,
-											 TUint32 aPslInfo)
-	{
-	return iController->AddressAlignMask(*this, aTargetFlags, aElementSize, aPslInfo);
-	}
-
-
-EXPORT_C const SDmacCaps& TDmaChannel::DmacCaps()
-	{
-	return *iDmacCaps;
-	}
-
-
-//
-// DFC callback function (static member).
-//
-void TDmaChannel::Dfc(TAny* aArg)
-	{
-	static_cast<TDmaChannel*>(aArg)->DoDfc();
-	}
-
-
-//
-// This is quite a long function, but what can you do...
-//
-void TDmaChannel::DoDfc()
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("TDmaChannel::DoDfc thread %O channel - %d",
-									&Kern::CurrentThread(), iPslId));
-	Wait();
-
-	// Atomically fetch and reset the number of DFCs queued by the ISR and the
-	// error flag. Leave the cancel flag alone for now.
-	const TUint32 w = __e32_atomic_and_ord32(&iIsrDfc, (TUint32)KCancelFlagMask);
-	TUint32 count = w & KDfcCountMask;
-	const TBool error = w & (TUint32)KErrorFlagMask;
-	TBool stop = w & (TUint32)KCancelFlagMask;
-	const TUint32 req_count_before = iQueuedRequests;
-	TUint32 req_count_after = 0;
-
-	__DMA_ASSERTD((count > 0) || stop);
-	__DMA_ASSERTD(!iRedoRequest); // We shouldn't be here if this is true
-
-	while (count && !stop)
-		{
-		--count;
-
-		__DMA_ASSERTA(!iReqQ.IsEmpty());
-
-		// If an error occurred it must have been reported on the last
-		// interrupt since transfers are suspended after an error.
-		DDmaRequest::TResult const res = (count == 0 && error) ?
-			DDmaRequest::EError : DDmaRequest::EOk;
-		DDmaRequest* pCompletedReq = NULL;
-		DDmaRequest* const pCurReq = _LOFF(iReqQ.First(), DDmaRequest, iLink);
-
-		if (res == DDmaRequest::EOk)
-			{
-			// Update state machine, current fragment, completed fragment and
-			// tell the DMAC to transfer the next fragment if necessary.
-			TBool complete;
-			if (iDmacCaps->iAsymHwDescriptors)
-				{
-				SDmaDesHdr* pCompletedSrcHdr = NULL;
-				SDmaDesHdr* pCompletedDstHdr = NULL;
-				DoDfc(*pCurReq, pCompletedSrcHdr, pCompletedDstHdr);
-				// We don't support asymmetrical ISR notifications and request
-				// completions yet, hence we can do the following assert test
-				// here; also 'complete' is determined equally by either the
-				// SRC or DST side.
-				__DMA_ASSERTD(!LOGICAL_XOR((pCompletedSrcHdr == pCurReq->iSrcLastHdr),
-										   (pCompletedDstHdr == pCurReq->iDstLastHdr)));
-				complete = (pCompletedDstHdr == pCurReq->iDstLastHdr);
-				}
-			else
-				{
-				SDmaDesHdr* pCompletedHdr = NULL;
-				DoDfc(*pCurReq, pCompletedHdr);
-				complete = (pCompletedHdr == pCurReq->iLastHdr);
-				}
-			// If just completed last fragment from current request, switch to
-			// next request (if any).
-			if (complete)
-				{
-				pCompletedReq = pCurReq;
-				pCurReq->iLink.Deque();
-				iQueuedRequests--;
-				if (iReqQ.IsEmpty())
-					ResetNullPtr();
-				pCompletedReq->OnDeque();
-				}
-			}
-		else
-			{
-			pCompletedReq = pCurReq;
-			}
-
-		if (pCompletedReq && !pCompletedReq->iIsrCb)
-			{
-			// Don't execute ISR callbacks here (they have already been called)
-			DDmaRequest::TCallback const cb = pCompletedReq->iCb;
-			if (cb)
-				{
-				// Old style callback
-				TAny* const arg = pCompletedReq->iCbArg;
-				Signal();
-				__KTRACE_OPT(KDMA, Kern::Printf("Client CB res=%d", res));
-				(*cb)(res, arg);
-				Wait();
-				}
-			else
-				{
-				// New style callback
-				TDmaCallback const ncb = pCompletedReq->iDmaCb;
-				if (ncb)
-					{
-					TAny* const arg = pCompletedReq->iDmaCbArg;
-					TDmaResult const result = (res == DDmaRequest::EOk) ?
-						EDmaResultOK : EDmaResultError;
-					Signal();
-					__KTRACE_OPT(KDMA, Kern::Printf("Client CB result=%d", result));
-					(*ncb)(EDmaCallbackRequestCompletion, result, arg, NULL);
-					Wait();
-					}
-				}
-			}
-		// Allow another thread in, in case they are trying to cancel
-		if (pCompletedReq || Flash())
-			{
-			stop = __e32_atomic_load_acq32(&iIsrDfc) & (TUint32)KCancelFlagMask;
-			}
-		}
-
-	if (stop)
-		{
-		// If another thread set the cancel flag, it should have
-		// cleaned up the request queue
-		__DMA_ASSERTD(IsQueueEmpty());
-
-		TDmaCancelInfo* const waiters = iCancelInfo;
-		iCancelInfo = NULL;
-
-		// make sure DFC doesn't run again until a new request completes
-		iDfc.Cancel();
-
-		// reset the ISR count - new requests can now be processed
-		__e32_atomic_store_rel32(&iIsrDfc, 0);
-
-		req_count_after = iQueuedRequests;
-		Signal();
-
-		// release threads doing CancelAll()
-		waiters->Signal();
-		}
-	else
-		{
-		req_count_after = iQueuedRequests;
-		Signal();
-		}
-
-	// Only call PSL if there were requests queued when we entered AND there
-	// are now no requests left on the queue (after also having executed all
-	// client callbacks).
-	if (iCallQueuedRequestFn)
-		{
-		if ((req_count_before != 0) && (req_count_after == 0))
-			{
-			QueuedRequestCountChanged();
-			}
-		}
-
-	__DMA_INVARIANT();
-	}
-
-
-void TDmaChannel::DoQueue(const DDmaRequest& /*aReq*/)
-	{
-	// Must be overridden
-	__DMA_UNREACHABLE_DEFAULT();
-	}
-
-
-//
-// Unlink the last item of a LLI chain from the next chain.
-// Default implementation does nothing. This is overridden by scatter-gather
-// channels.
-//
-void TDmaChannel::DoUnlink(SDmaDesHdr& /*aHdr*/)
-	{
-	}
-
-
-void TDmaChannel::DoDfc(const DDmaRequest& /*aCurReq*/, SDmaDesHdr*& /*aCompletedHdr*/)
-	{
-	// To make sure this version of the function isn't called for channels for
-	// which it isn't appropriate (and which therefore don't override it) we
-	// put this check in here.
-	__DMA_UNREACHABLE_DEFAULT();
-	}
-
-
-void TDmaChannel::DoDfc(const DDmaRequest& /*aCurReq*/, SDmaDesHdr*& /*aSrcCompletedHdr*/,
-						SDmaDesHdr*& /*aDstCompletedHdr*/)
-	{
-	// To make sure this version of the function isn't called for channels for
-	// which it isn't appropriate (and which therefore don't override it) we
-	// put this check in here.
-	__DMA_UNREACHABLE_DEFAULT();
-	}
-
-
-void TDmaChannel::SetNullPtr(const DDmaRequest& aReq)
-	{
-	// iNullPtr points to iCurHdr for an empty queue
-	*iNullPtr = aReq.iFirstHdr;
-	iNullPtr = &(aReq.iLastHdr->iNext);
-	}
-
-
-void TDmaChannel::ResetNullPtr()
-	{
-	iCurHdr = NULL;
-	iNullPtr = &iCurHdr;
-	}
-
-
-/** PSL may override */
-void TDmaChannel::QueuedRequestCountChanged()
-	{
-	__KTRACE_OPT(KDMA, Kern::Printf("TDmaChannel::QueuedRequestCountChanged(): "
-									"disabling further calls"));
-	Wait();
-	iCallQueuedRequestFn = EFalse;
-	Signal();
-	}
-
-
-#ifdef _DEBUG
-void TDmaChannel::Invariant()
-	{
-	Wait();
-
-	__DMA_ASSERTD(iReqCount >= 0);
-
-	__DMA_ASSERTD(iCurHdr == NULL || iController->IsValidHdr(iCurHdr));
-
-	// should always point to NULL pointer ending fragment queue
-	__DMA_ASSERTD(*iNullPtr == NULL);
-
-	__DMA_ASSERTD((0 <= iAvailDesCount) && (iAvailDesCount <= iMaxDesCount));
-
-	__DMA_ASSERTD(LOGICAL_XOR(iCurHdr, IsQueueEmpty()));
-	if (iCurHdr == NULL)
-		{
-		__DMA_ASSERTD(iNullPtr == &iCurHdr);
-		}
-
-	Signal();
-	}
-#endif
-
-
-//////////////////////////////////////////////////////////////////////////////
-// TDmaSbChannel
-
-void TDmaSbChannel::DoQueue(const DDmaRequest& /*aReq*/)
-	{
-	if (iState != ETransferring)
-		{
-		iController->Transfer(*this, *iCurHdr);
-		iState = ETransferring;
-		}
-	}
-
-
-void TDmaSbChannel::DoCancelAll()
-	{
-	__DMA_ASSERTD(iState == ETransferring);
-	iState = EIdle;
-	}
-
-
-void TDmaSbChannel::DoDfc(const DDmaRequest& /*aCurReq*/, SDmaDesHdr*& aCompletedHdr)
-	{
-	__DMA_ASSERTD(iState == ETransferring);
-	aCompletedHdr = iCurHdr;
-	iCurHdr = iCurHdr->iNext;
-	if (iCurHdr != NULL)
-		{
-		iController->Transfer(*this, *iCurHdr);
-		}
-	else
-		{
-		iState = EIdle;
-		}
-	}
-
-
-//////////////////////////////////////////////////////////////////////////////
-// TDmaDbChannel
-
-void TDmaDbChannel::DoQueue(const DDmaRequest& aReq)
-	{
-	switch (iState)
-		{
-	case EIdle:
-		iController->Transfer(*this, *iCurHdr);
-		if (iCurHdr->iNext)
-			{
-			iController->Transfer(*this, *(iCurHdr->iNext));
-			iState = ETransferring;
-			}
-		else
-			iState = ETransferringLast;
-		break;
-	case ETransferring:
-		// nothing to do
-		break;
-	case ETransferringLast:
-		iController->Transfer(*this, *(aReq.iFirstHdr));
-		iState = ETransferring;
-		break;
-	default:
-		__DMA_CANT_HAPPEN();
-		}
-	}
-
-
-void TDmaDbChannel::DoCancelAll()
-	{
-	iState = EIdle;
-	}
-
-
-void TDmaDbChannel::DoDfc(const DDmaRequest& /*aCurReq*/, SDmaDesHdr*& aCompletedHdr)
-	{
-	aCompletedHdr = iCurHdr;
-	iCurHdr = iCurHdr->iNext;
-	switch (iState)
-		{
-	case ETransferringLast:
-		iState = EIdle;
-		break;
-	case ETransferring:
-		if (iCurHdr->iNext == NULL)
-			iState = ETransferringLast;
-		else
-			iController->Transfer(*this, *(iCurHdr->iNext));
-		break;
-	default:
-		__DMA_CANT_HAPPEN();
-		}
-	}
-
-
-//////////////////////////////////////////////////////////////////////////////
-// TDmaSgChannel
-
-void TDmaSgChannel::DoQueue(const DDmaRequest& aReq)
-	{
-	if (iState == ETransferring)
-		{
-		__DMA_ASSERTD(!aReq.iLink.Alone());
-		DDmaRequest* pReqPrev = _LOFF(aReq.iLink.iPrev, DDmaRequest, iLink);
-		iController->AppendHwDes(*this, *(pReqPrev->iLastHdr), *(aReq.iFirstHdr));
-		}
-	else
-		{
-		iController->Transfer(*this, *(aReq.iFirstHdr));
-		iState = ETransferring;
-		}
-	}
-
-
-void TDmaSgChannel::DoCancelAll()
-	{
-	__DMA_ASSERTD(iState == ETransferring);
-	iState = EIdle;
-	}
-
-
-void TDmaSgChannel::DoUnlink(SDmaDesHdr& aHdr)
-	{
-	iController->UnlinkHwDes(*this, aHdr);
-	}
-
-
-void TDmaSgChannel::DoDfc(const DDmaRequest& aCurReq, SDmaDesHdr*& aCompletedHdr)
-	{
-	__DMA_ASSERTD(iState == ETransferring);
-	aCompletedHdr = aCurReq.iLastHdr;
-	iCurHdr = aCompletedHdr->iNext;
-	iState = (iCurHdr != NULL) ? ETransferring : EIdle;
-	}
-
-
-//////////////////////////////////////////////////////////////////////////////
-// TDmaAsymSgChannel
-
-TDmaAsymSgChannel::TDmaAsymSgChannel()
-	: iSrcCurHdr(NULL),
-	  iSrcNullPtr(&iSrcCurHdr),
-	  iDstCurHdr(NULL),
-	  iDstNullPtr(&iDstCurHdr)
-	{
-	__DMA_INVARIANT();
-	}
-
-
-void TDmaAsymSgChannel::SetNullPtr(const DDmaRequest& aReq)
-	{
-	// i{Src|Dst}NullPtr points to i{Src|Dst}CurHdr for an empty queue
-	*iSrcNullPtr = aReq.iSrcFirstHdr;
-	*iDstNullPtr = aReq.iDstFirstHdr;
-	iSrcNullPtr = &(aReq.iSrcLastHdr->iNext);
-	iDstNullPtr = &(aReq.iDstLastHdr->iNext);
-	}
-
-
-void TDmaAsymSgChannel::ResetNullPtr()
-	{
-	iSrcCurHdr = NULL;
-	iSrcNullPtr = &iSrcCurHdr;
-	iDstCurHdr = NULL;
-	iDstNullPtr = &iDstCurHdr;
-	}
-
-
-void TDmaAsymSgChannel::DoQueue(const DDmaRequest& aReq)
-	{
-	if (iState == ETransferring)
-		{
-		__DMA_ASSERTD(!aReq.iLink.Alone());
-		DDmaRequest* pReqPrev = _LOFF(aReq.iLink.iPrev, DDmaRequest, iLink);
-		iController->AppendHwDes(*this,
-								 *(pReqPrev->iSrcLastHdr), *(aReq.iSrcFirstHdr),
-								 *(pReqPrev->iDstLastHdr), *(aReq.iDstFirstHdr));
-		}
-	else
-		{
-		iController->Transfer(*this, *(aReq.iSrcFirstHdr), *(aReq.iDstFirstHdr));
-		iState = ETransferring;
-		}
-	}
-
-
-void TDmaAsymSgChannel::DoCancelAll()
-	{
-	__DMA_ASSERTD(iState == ETransferring);
-	iState = EIdle;
-	}
-
-
-void TDmaAsymSgChannel::DoUnlink(SDmaDesHdr& aHdr)
-	{
-	iController->UnlinkHwDes(*this, aHdr);
-	}
-
-
-void TDmaAsymSgChannel::DoDfc(const DDmaRequest& aCurReq, SDmaDesHdr*& aSrcCompletedHdr,
-							  SDmaDesHdr*& aDstCompletedHdr)
-	{
-	__DMA_ASSERTD(iState == ETransferring);
-	aSrcCompletedHdr = aCurReq.iSrcLastHdr;
-	iSrcCurHdr = aSrcCompletedHdr->iNext;
-	aDstCompletedHdr = aCurReq.iDstLastHdr;
-	iDstCurHdr = aDstCompletedHdr->iNext;
-	// Must be either both NULL or none of them.
-	__DMA_ASSERTD(!LOGICAL_XOR(iSrcCurHdr, iDstCurHdr));
-	iState = (iSrcCurHdr != NULL) ? ETransferring : EIdle;
-	}
-
-
-#ifdef _DEBUG
-void TDmaAsymSgChannel::Invariant()
-	{
-	Wait();
-
-	__DMA_ASSERTD(iReqCount >= 0);
-
-	__DMA_ASSERTD(iSrcCurHdr == NULL || iController->IsValidHdr(iSrcCurHdr));
-	__DMA_ASSERTD(iDstCurHdr == NULL || iController->IsValidHdr(iDstCurHdr));
-
-	// should always point to NULL pointer ending fragment queue
-	__DMA_ASSERTD(*iSrcNullPtr == NULL);
-	__DMA_ASSERTD(*iDstNullPtr == NULL);
-
-	__DMA_ASSERTD((0 <= iAvailDesCount) && (iAvailDesCount <= iMaxDesCount));
-
-	__DMA_ASSERTD((iSrcCurHdr && iDstCurHdr && !IsQueueEmpty()) ||
-				  (!iSrcCurHdr && !iDstCurHdr && IsQueueEmpty()));
-	if (iSrcCurHdr == NULL)
-		{
-		__DMA_ASSERTD(iSrcNullPtr == &iSrcCurHdr);
-		}
-	if (iDstCurHdr == NULL)
-		{
-		__DMA_ASSERTD(iDstNullPtr == &iDstCurHdr);
-		}
-
-	Signal();
-	}
-#endif