// All rights reserved.

// This component and the accompanying materials are made available

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

// which accompanies this distribution, and is available

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

//

// Initial Contributors:

// Nokia Corporation - initial contribution.

//

// Contributors:

//

// Description:

// e32\include\drivers\dmasupport.h

// 

//

#ifndef DMASUPPORT_H

#define DMASUPPORT_H

#include "plat_priv.h"

#include <d32locd.h>

class TLocDrvRequest;

/**

@internalTechnology

Class used for read / write requests to the local media subsystem to gain access

to physical memory address to make use of DMA without the need of an intermediate buffer.

*/

class DDmaHelper : public DBase

	{

public:

	enum TMemoryType

		{

		EUnknown,

		EFileServerChunk,

		ESharedChunk,

		};

	/**

	Class used to describe a number of contiguous physical pages

	*/

	class TPageList

		{

	public:

		TPhysAddr iAddress;	// address of page

		TInt 	  iLength;

		};

public:

	DDmaHelper();

	~DDmaHelper();

	TInt Construct(TInt aLength, TInt aMediaBlockSize, TInt aDmaAlignment);

	TInt SendReceive(TLocDrvRequest& aReq, TLinAddr aLinAddress);

	TInt GetPhysicalAddress(TPhysAddr& aAddr, TInt& aLen);

#ifdef __DEMAND_PAGING__

	static TInt GetPhysicalAddress(TLocDrvRequest& aReq, TPhysAddr& aAddr, TInt& aLen);

#endif

	inline TInt PageSize()	const { return iPageSize; }

private:

	static inline TBool IsPageAligned(TLinAddr aAddr);

	static inline TLinAddr PageAlign(TLinAddr aAddr);

	static inline TLinAddr PageOffset(TLinAddr aAddr);

	inline TInt MaxFragLength()	const;

	inline void SetFragLength(TInt aLength);

	inline TInt FragLength()	const;

	inline TInt LengthRemaining() const;

	inline TBool IsDmaAligned(TLinAddr aAddr);

	inline TBool IsBlockAligned(TInt64 aPos);

	inline TInt64 BlockAlign(TInt64 aPos);

	inline TInt BlockOffset(TInt64 aPos);

	inline TLinAddr LinAddress() const;

	void ResetPageLists();

	TInt UpdateRemoteDescriptorLength(TInt aLength);

	TInt RequestStart();

	void RequestEnd();

	void BuildPageList();

	void ReleasePages(TLinAddr aAddr);

private:

	TInt iMediaBlockSize;		// Minimum transfer size (bytes) for the media.

	TInt64 iMediaBlockSizeMask;	// iMediaBlockSize - 1

	TInt iDmaAlignment;			// DMA Alignment req for media's DMA controller i.e. word alignment

	static TInt iPageSize;		// Memory page size in bytes (e.g. 4096 Bytes)

	static TInt iPageSizeLog2;	// Log2 of page size (e.g. 4096 -> 12)

	static TInt iPageSizeMsk;	// Mask of page size (e.g. 4096-1 -> 4095)

	TInt iMaxPages;				// Maximum number of pages that can be stored by this object

	DThread* iRemoteThread;		// 

	DThread* iCurrentThread;	//  

	DThread* iOwningThread;		// Thread owning remote descriptor, either iRemoteThread or iCurrentThread

	TLocDrvRequest* iReq;		// Current TLocDrvRequest

	// The following attributes are copied from the current TLocDrvRequest

	TInt iReqId;

	TInt iReqRemoteDesOffset;

	TInt iReqFlags;				// 

	TInt iReqLenClient;			// length of data requested by client (unmodified)

	TInt64 iReqPosClient;		// position of data requested by client (unmodified)

	TLinAddr iLinAddressUser;	// linear address of client buffer in user process

	TLinAddr iLinAddressKernel;	// linear address of client buffer in kernel process

	TInt iFragLen;				// length of data to be read into physical pages (possibly < a multiple of the page-size)

	TInt iFragLenRemaining;		// length of data to be read left in this fragment

	TMemoryType iMemoryType;

	/** array of (possibly non-contiguous) pages */

	TPhysAddr* iPageArray;

	TInt iPageArrayCount;

	/** list of contiguous pages */

	TPageList* iPageList;

	TInt iPageListCount;

	TInt iIndex;					// Current memory fragment index

	/** Represents the current read/write position in terms of an offset 

	from the start of the caller's linear address */ 

	TInt iLenConsumed;				// Offset from start of client buffer

	DChunk* iChunk;					// Shared chunk object in use

	TInt    iChunkOffset;			// Offset within shared chunk

	TUint32 iMapAttr;				// mmu mapping attributes for the Shared chunk or pinned physical memory.

	TUint32 iPhysAddr;				// Physical Address of chunk (if contiguous)

	TInt iLockCount;				// Prevent 2+ threads accessing this object

	TBool iPhysPinningAvailable;    // True if physical memory pinning Kernel interface is available

	TUint  iPageColour;				// Mapping colour of the first page in iPageArray.

	TPhysicalPinObject* iPhysicalPinObject;	// Physical pinning object.

	};

#endif	// DMASUPPORT_H