fxcommonbuffer.hpp

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/*++
 
Copyright (c) Microsoft Corporation
 
Module Name:
 
    FxCommonBuffer.hpp
 
Abstract:
 
    WDF CommonBuffer Object support
 
Environment:
 
    Kernel mode only.
 
Notes:
 
 
Revision History:
 
--*/
 
#ifndef _FXCOMMONBUFFER_H_
#define _FXCOMMONBUFFER_H_
 
//
// Calculate an "aligned" address (Logical or Virtual) per
// a specific alignment value.
//
FORCEINLINE
PVOID
FX_ALIGN_VIRTUAL_ADDRESS(
    __in PVOID VA,
    __in size_t AlignTo
    )
{
   return (PVOID)(((ULONG_PTR)VA + AlignTo) & ~AlignTo);
}
 
FORCEINLINE
ULONGLONG
FX_ALIGN_LOGICAL_ADDRESS(
    __in PHYSICAL_ADDRESS LA,
    __in size_t AlignTo
    )
{
   return (LA.QuadPart + AlignTo) & ~((ULONGLONG)AlignTo);
}
 
//
// Declare the FxCommonBuffer class
//
class FxCommonBuffer : public FxNonPagedObject {
 
public:
 
    FxCommonBuffer(
        __in PFX_DRIVER_GLOBALS FxDriverGlobals,
        __in FxDmaEnabler * pDmaEnabler
        );
 
    virtual
    BOOLEAN
    Dispose(
        VOID
        );
 
    _Must_inspect_result_
    NTSTATUS
    AllocateCommonBuffer(
        __in size_t   Length
        );
 
    VOID
    FreeCommonBuffer(
        VOID
        );
 
    __forceinline
    PHYSICAL_ADDRESS
    GetAlignedLogicalAddress(
        VOID
        )
    {
        return m_BufferAlignedLA;
    }
 
    __forceinline
    PVOID
    GetAlignedVirtualAddress(
        VOID
        )
    {
        return m_BufferAlignedVA;
    }
 
    __forceinline
    size_t
    GetLength(
        VOID
        )
    {
        return m_Length;
    }
 
    __forceinline
    VOID
    SetAlignment(
        __in ULONG Alignment
        )
    {
        m_Alignment = Alignment;
    }
 
protected:
 
    //
    // Unaligned virtual address
    //
    PVOID                 m_BufferRawVA;
 
    //
    // Aligned virtual address
    //
    PVOID                 m_BufferAlignedVA;
 
    //
    // Aligned logical address
    //
    PHYSICAL_ADDRESS      m_BufferAlignedLA;
 
    //
    // Unaligned logical address
    //
    PHYSICAL_ADDRESS      m_BufferRawLA;
 
    //
    // Pointer to the DMA enabler
    //
    FxDmaEnabler        * m_DmaEnabler;
 
    //
    // Length specified by the caller
    //
    size_t                m_Length;
 
    //
    // Actual length used to allocate buffer after adding the alignement
    // value.
    //
    size_t                m_RawLength;
 
    //
    // Alignment of the allocated buffer.
    //
    size_t               m_Alignment;
 
};
 
#endif // _FXCOMMONBUFFER_H_