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GetDmaAdapterInfo routine

The GetDmaAdapterInfo routine retrieves information about the hardware capabilities of a system DMA channel.

Syntax


NTSTATUS GetDmaAdapterInfo(
  _In_     PDMA_ADAPTER  DmaAdapter,
  _Inout_  PDMA_ADAPTER_INFO  AdapterInfo
);

Parameters

DmaAdapter [in]

A pointer to a DMA_ADAPTER structure. This structure is the adapter object that represents the driver's system DMA channel. The caller obtained this pointer from a previous call to the IoGetDmaAdapter routine.

AdapterInfo [in, out]

A pointer to a caller-allocated DMA_ADAPTER_INFO structure. The routine writes information about the system DMA controller into this structure. The caller must set the Version member of this structure to DMA_ADAPTER_INFO_VERSION1 before calling GetDmaAdapterInfo.

Return value

GetDmaAdapterInfo returns STATUS_SUCCESS if the call is successful. Possible error return values include the following status code.

Return codeDescription
STATUS_NOT_SUPPORTED

The routine does not support the specified version of the DMA_ADAPTER_INFO_XXX structure.

 

Remarks

GetDmaAdapterInfo is not a system routine that can be called directly by name. This routine can be called only by pointer from the address returned in a DMA_OPERATIONS structure. Drivers obtain the address of this routine by calling IoGetDmaAdapter with the Version member of the DeviceDescription parameter set to DEVICE_DESCRIPTION_VERSION3. If IoGetDmaAdapter returns NULL, the routine is not available on your platform.

GetDmaAdapterInfo retrieves the following information:

  • The maximum number of elements in a scatter/gather list that the DMA controller can process in a single scatter/gather DMA operation.

  • The width, in bits, of a DMA address.

For information about the DMA adapter information that is provided by version 1 of the DMA_ADAPTER_INFO_XXX structure, see DMA_ADAPTER_INFO_V1.

Requirements

Version

Available starting with Windows 8.

Header

Wdm.h (include Wdm.h, Ntddk.h, or Ntifs.h)

IRQL

<= DISPATCH_LEVEL

See also

DMA_ADAPTER
DMA_ADAPTER_INFO
DMA_OPERATIONS
IoGetDmaAdapter

 

 

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