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/*++
Copyright (C) Microsoft Corporation. All rights reserved.
Module Name:
mmc.h
Abstract:
Functions/macros for using the scratch buffer and scratch request/SRB
in the serial I/O queue context
Author:
Environment:
kernel mode only
Notes:
Revision History:
--*/
#ifndef __SCRATCH_H__
#define __SCRATCH_H__
_IRQL_requires_max_(APC_LEVEL)
VOID
ScratchBuffer_Deallocate(
_Inout_ PCDROM_DEVICE_EXTENSION DeviceExtension
);
_IRQL_requires_max_(APC_LEVEL)
BOOLEAN
ScratchBuffer_Allocate(
_Inout_ PCDROM_DEVICE_EXTENSION DeviceExtension
);
VOID
ScratchBuffer_ResetItems(
_Inout_ PCDROM_DEVICE_EXTENSION DeviceExtension,
_In_ BOOLEAN ResetRequestHistory
);
_IRQL_requires_max_(APC_LEVEL)
VOID
ScratchBuffer_SetupSrb(
_Inout_ PCDROM_DEVICE_EXTENSION DeviceExtension,
_In_opt_ WDFREQUEST OriginalRequest,
_In_ ULONG MaximumTransferLength,
_In_ BOOLEAN GetDataFromDevice
);
VOID
ScratchBuffer_SetupReadWriteSrb(
_Inout_ PCDROM_DEVICE_EXTENSION DeviceExtension,
_In_ WDFREQUEST OriginalRequest,
_In_ LARGE_INTEGER StartingOffset,
_In_ ULONG RequiredLength,
_Inout_updates_bytes_(RequiredLength) UCHAR* DataBuffer,
_In_ BOOLEAN IsReadRequest,
_In_ BOOLEAN UsePartialMdl
);
NTSTATUS
ScratchBuffer_SendSrb(
_Inout_ PCDROM_DEVICE_EXTENSION DeviceExtension,
_In_ BOOLEAN SynchronousSrb,
_When_(SynchronousSrb, _Pre_null_)
_When_(!SynchronousSrb, _In_opt_)
PSRB_HISTORY_ITEM *SrbHistoryItem
);
NTSTATUS
ScratchBuffer_PerformNextReadWrite(
_In_ PCDROM_DEVICE_EXTENSION DeviceExtension,
_In_ BOOLEAN FirstTry
);
#if DBG
#define ScratchBuffer_BeginUse(context) ScratchBuffer_BeginUseX((context), __FILE__, __LINE__)
#else
#define ScratchBuffer_BeginUse(context) ScratchBuffer_BeginUseX((context), NULL, (ULONG)-1)
#endif
__inline VOID ScratchBuffer_BeginUseX(_Inout_ PCDROM_DEVICE_EXTENSION DeviceExtension, _In_opt_ LPCSTR File, ULONG Line)
{
// NOTE: these are not "real" locks. They are simply to help
// avoid multiple uses of the scratch buffer. Thus, it
// is not critical to have atomic operations here.
PVOID tmp = InterlockedCompareExchangePointer((PVOID)&(DeviceExtension->ScratchContext.ScratchInUse), (PVOID)-1, NULL);
NT_ASSERT(tmp == NULL);
UNREFERENCED_PARAMETER(tmp); //defensive coding, avoid PREFAST warning.
DeviceExtension->ScratchContext.ScratchInUseFileName = File;
DeviceExtension->ScratchContext.ScratchInUseLineNumber = Line;
ScratchBuffer_ResetItems(DeviceExtension, TRUE);
RequestClearSendTime(DeviceExtension->ScratchContext.ScratchRequest);
return;
}
__inline VOID ScratchBuffer_EndUse(_Inout_ PCDROM_DEVICE_EXTENSION DeviceExtension)
{
// NOTE: these are not "real" locks. They are simply to help
// avoid multiple uses of the scratch buffer. Thus, it
// is not critical to have atomic operations here.
// On lock release, we erase ScratchInUseFileName and ScratchInUseLineNumber _before_ releasing ScratchInUse,
// because otherwise we may erase these after the lock has been acquired again by another thread. We store the
// old values of ScratchInUseFileName and ScratchInUseLineNumber in local variables to facilitate debugging,
// if the ASSERT at the end of the function is hit.
PCSTR scratchInUseFileName;
ULONG scratchInUseLineNumber;
PVOID tmp;
scratchInUseFileName = DeviceExtension->ScratchContext.ScratchInUseFileName;
scratchInUseLineNumber = DeviceExtension->ScratchContext.ScratchInUseLineNumber;
UNREFERENCED_PARAMETER(scratchInUseFileName);
UNREFERENCED_PARAMETER(scratchInUseLineNumber);
DeviceExtension->ScratchContext.ScratchInUseFileName = NULL;
DeviceExtension->ScratchContext.ScratchInUseLineNumber = 0;
//
// If we have used the PartialMdl in the scratch context we should notify MM that we will be reusing it
// otherwise it may leak System VA if some one below us has mapped the same.
//
if (DeviceExtension->ScratchContext.PartialMdlIsBuilt != FALSE)
{
MmPrepareMdlForReuse(DeviceExtension->ScratchContext.PartialMdl);
DeviceExtension->ScratchContext.PartialMdlIsBuilt = FALSE;
}
tmp = InterlockedCompareExchangePointer((PVOID)&(DeviceExtension->ScratchContext.ScratchInUse), NULL, (PVOID)-1);
NT_ASSERT(tmp == ((PVOID)-1));
UNREFERENCED_PARAMETER(tmp); //defensive coding, avoid PREFAST warning.
return;
}
VOID
CompressSrbHistoryData(
_Inout_ PSRB_HISTORY RequestHistory
);
VOID
ValidateSrbHistoryDataPresumptions(
_In_ SRB_HISTORY const* RequestHistory
);
_IRQL_requires_max_(APC_LEVEL)
NTSTATUS
ScratchBuffer_ExecuteCdbEx(
_Inout_ PCDROM_DEVICE_EXTENSION DeviceExtension,
_In_opt_ WDFREQUEST OriginalRequest,
_In_ ULONG TransferSize,
_In_ BOOLEAN GetDataFromDevice,
_In_ PCDB Cdb,
_In_ UCHAR OprationLength,
_In_ ULONG TimeoutValue
);
_IRQL_requires_max_(APC_LEVEL)
__inline
NTSTATUS
ScratchBuffer_ExecuteCdb(
_Inout_ PCDROM_DEVICE_EXTENSION DeviceExtension,
_In_opt_ WDFREQUEST OriginalRequest,
_In_ ULONG TransferSize,
_In_ BOOLEAN GetDataFromDevice,
_In_ PCDB Cdb,
_In_ UCHAR OprationLength
)
{
return ScratchBuffer_ExecuteCdbEx(DeviceExtension,
OriginalRequest,
TransferSize,
GetDataFromDevice,
Cdb,
OprationLength,
0);
}
KDEFERRED_ROUTINE ScratchBuffer_ReadWriteTimerRoutine;
#endif //__SCRATCH_H__
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