src/system/kernel/device_manager/IOCache.h

   1 /*
   2  * Copyright 2010, Ingo Weinhold, ingo_weinhold@gmx.de.
   3  * Distributed under the terms of the MIT License.
   4  */
   5 #ifndef IO_CACHE_H
   6 #define IO_CACHE_H
   7
   8
   9 #include <lock.h>
  10 #include <vm/vm_page.h>
  11
  12 #include "dma_resources.h"
  13 #include "IOScheduler.h"
  14
  15
  16 struct VMCache;
  17 struct vm_page;
  18
  19
  20 class IOCache : public IOScheduler {
  21 public:
  22                                                                 IOCache(DMAResource* resource,
  23                                                                         size_t cacheLineSize);
  24         virtual                                         ~IOCache();
  25
  26         virtual status_t                        Init(const char* name);
  27
  28         virtual void                            SetDeviceCapacity(off_t deviceCapacity);
  29         virtual void                            MediaChanged();
  30
  31         virtual status_t                        ScheduleRequest(IORequest* request);
  32
  33         virtual void                            AbortRequest(IORequest* request,
  34                                                                         status_t status = B_CANCELED);
  35         virtual void                            OperationCompleted(IOOperation* operation,
  36                                                                         status_t status,
  37                                                                         generic_size_t transferredBytes);
  38
  39         virtual void                            Dump() const;
  40
  41 private:
  42                         struct Operation;
  43
  44 private:
  45                         status_t                        _DoRequest(IORequest* request,
  46                                                                         generic_size_t& _bytesTransferred);
  47                         status_t                        _TransferRequestLine(IORequest* request,
  48                                                                         off_t lineOffset, size_t lineSize,
  49                                                                         off_t requestOffset, size_t requestLength);
  50                         status_t                        _TransferRequestLineUncached(IORequest* request,
  51                                                                         off_t lineOffset, off_t requestOffset,
  52                                                                         size_t requestLength);
  53                         status_t                        _DoOperation(Operation& operation);
  54
  55                         status_t                        _TransferPages(size_t firstPage,
  56                                                                         size_t pageCount, bool isWrite, bool isVIP);
  57                         void                            _DiscardPages(size_t firstPage,
  58                                                                         size_t pageCount);
  59                         void                            _CachePages(size_t firstPage, size_t pageCount);
  60
  61                         status_t                        _CopyPages(IORequest* request,
  62                                                                         size_t pagesRelativeOffset,
  63                                                                         off_t requestOffset, size_t requestLength,
  64                                                                         bool toRequest);
  65
  66                         status_t                        _MapPages(size_t firstPage, size_t endPage);
  67                         void                            _UnmapPages(size_t firstPage, size_t endPage);
  68
  69 private:
  70                         mutex                           fSerializationLock;
  71                         off_t                           fDeviceCapacity;
  72                         size_t                          fLineSize;
  73                         uint32                          fLineSizeShift;
  74                         size_t                          fPagesPerLine;
  75                         area_id                         fArea;
  76                         void*                           fAreaBase;
  77                         vm_page_reservation     fMappingReservation;
  78                         VMCache*                        fCache;
  79                         vm_page**                       fPages;
  80                         generic_io_vec*         fVecs;
  81 };
  82
  83
  84 #endif  // IO_CACHE_H