* Copyright 2010, Ingo Weinhold, ingo_weinhold@gmx.de.
* Distributed under the terms of the MIT License.
*/
#ifndef IO_CACHE_H
#define IO_CACHE_H
#include <lock.h>
#include <vm/vm_page.h>
#include "dma_resources.h"
#include "IOScheduler.h"
struct VMCache;
struct vm_page;
class IOCache : public IOScheduler {
public:
IOCache(DMAResource* resource,
size_t cacheLineSize);
virtual ~IOCache();
virtual status_t Init(const char* name);
virtual void SetDeviceCapacity(off_t deviceCapacity);
virtual void MediaChanged();
virtual status_t ScheduleRequest(IORequest* request);
virtual void AbortRequest(IORequest* request,
status_t status = B_CANCELED);
virtual void OperationCompleted(IOOperation* operation,
status_t status,
generic_size_t transferredBytes);
virtual void Dump() const;
private:
struct Operation;
private:
status_t _DoRequest(IORequest* request,
generic_size_t& _bytesTransferred);
status_t _TransferRequestLine(IORequest* request,
off_t lineOffset, size_t lineSize,
off_t requestOffset, size_t requestLength);
status_t _TransferRequestLineUncached(IORequest* request,
off_t lineOffset, off_t requestOffset,
size_t requestLength);
status_t _DoOperation(Operation& operation);
status_t _TransferPages(size_t firstPage,
size_t pageCount, bool isWrite, bool isVIP);
void _DiscardPages(size_t firstPage,
size_t pageCount);
void _CachePages(size_t firstPage, size_t pageCount);
status_t _CopyPages(IORequest* request,
size_t pagesRelativeOffset,
off_t requestOffset, size_t requestLength,
bool toRequest);
status_t _MapPages(size_t firstPage, size_t endPage);
void _UnmapPages(size_t firstPage, size_t endPage);
private:
mutex fSerializationLock;
off_t fDeviceCapacity;
size_t fLineSize;
uint32 fLineSizeShift;
size_t fPagesPerLine;
area_id fArea;
void* fAreaBase;
vm_page_reservation fMappingReservation;
VMCache* fCache;
vm_page** fPages;
generic_io_vec* fVecs;
};
#endif
