dmapool.h

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/*
 * PROJECT:     ReactOS xHCI Host Controller Driver
 * LICENSE:     MIT (https://spdx.org/licenses/MIT)
 * PURPOSE:     DMA enabler and the pool of zeroed common buffers
 * COPYRIGHT:   Copyright 2026 Justin Miller <justin.miller@reactos.org>
 */
 
#pragma once
 
class XhciController;
 
struct XhciDmaBuffer
{
    LIST_ENTRY Link;            
    PVOID VirtualAddress;
    PHYSICAL_ADDRESS LogicalAddress;
    ULONG Size;
    PVOID Page;                 
    BOOLEAN Owned;              
};
 
class XhciCommonBuffer
{
public:
    NTSTATUS
    Create(
        _In_ XhciController* Controller);
    NTSTATUS Prepare();
    VOID Release();
    VOID D0Exit();
    VOID PostResetFlush();
    VOID OnHostLost();
 
    VOID Rebalance();
 
    _IRQL_requires_max_(DISPATCH_LEVEL)
    XhciDmaBuffer*
    Acquire(
        _In_ ULONG Size);
 
    _IRQL_requires_max_(DISPATCH_LEVEL)
    NTSTATUS
    AcquireList(
        _In_ ULONG Size,
        _In_ ULONG Count,
        _Inout_ PLIST_ENTRY List);
 
    _IRQL_requires_max_(DISPATCH_LEVEL)
    VOID
    Free(
        _In_ XhciDmaBuffer* Buffer);
 
    _IRQL_requires_max_(DISPATCH_LEVEL)
    VOID
    FreeList(
        _Inout_ PLIST_ENTRY List);
 
    WDFDMAENABLER DmaEnabler() const;
 
    PDMA_ADAPTER DmaAdapter() const;
    ULONG MaxDmaSize() const;
    ULONG MapRegisterCount() const;
 
    /* Work item and cleanup bodies, called only from dmapool.cpp */
    _IRQL_requires_(PASSIVE_LEVEL)
    VOID GrowthWork();
 
    _IRQL_requires_(PASSIVE_LEVEL)
    VOID ReclaimWork();
 
    VOID EnablerCleanup();
 
private:
    struct SizeClass
    {
        LIST_ENTRY FreeList;
        LIST_ENTRY PageList;
        ULONG SegmentSize;
        ULONG Total;
        ULONG Available;
        ULONG GrowBelow;        
        ULONG GrowBy;           
        ULONG KeepAtLeast;      
    };
 
    _IRQL_requires_(PASSIVE_LEVEL)
    NTSTATUS CreateEnabler();
 
    SizeClass*
    ClassForSize(
        _In_ ULONG Size);
 
    _IRQL_requires_(PASSIVE_LEVEL)
    VOID
    AddSegments(
        _Inout_ SizeClass* Class,
        _In_ ULONG Count);
 
    _IRQL_requires_max_(DISPATCH_LEVEL)
    BOOLEAN
    Grab(
        _Inout_ SizeClass* Class,
        _In_ ULONG Count,
        _Out_ PLIST_ENTRY Taken,
        _Out_ PBOOLEAN NeedGrow);
 
    _Requires_lock_held_(m_Lock)
    BOOLEAN
    ReturnFree(
        _Inout_ XhciDmaBuffer* Buffer);
 
    _Requires_lock_held_(m_Lock)
    VOID
    ShrinkClass(
        _Inout_ SizeClass* Class);
 
    _IRQL_requires_max_(DISPATCH_LEVEL)
    VOID QueueGrowth();
 
    _IRQL_requires_(PASSIVE_LEVEL)
    VOID Flush();
 
    XhciController* m_Controller;
    WDFDMAENABLER m_Enabler;
    PDMA_ADAPTER m_Adapter;
    ULONG m_MaxDmaSize;
    ULONG m_MapRegisters;
    BOOLEAN m_Initialized;
    BOOLEAN m_HoldsUcxReference;
 
    KSPIN_LOCK m_Lock;
    SizeClass m_Small;
    SizeClass m_Large;
    ULONG m_PagesTotal;
    ULONG m_PagesInUse;
 
    LIST_ENTRY m_ReclaimList;
    ULONG m_ReclaimPages;
    WDFWORKITEM m_ReclaimItem;
 
    WDFWORKITEM m_GrowthItem;
    BOOLEAN m_GrowthQueued;
    ULONG m_GrowthOutstanding;
    KEVENT m_GrowthIdle;
};