PGET_DMA_ADAPTER_INFO callback function (wdm.h)

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

Syntax

PGET_DMA_ADAPTER_INFO PgetDmaAdapterInfo;

NTSTATUS PgetDmaAdapterInfo(
  [in]      PDMA_ADAPTER DmaAdapter,
  [in, out] PDMA_ADAPTER_INFO AdapterInfo
)
{...}

Parameters

[in] DmaAdapter

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.

[in, out] AdapterInfo

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.

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.

Requirements

See also

DMA_ADAPTER

DMA_ADAPTER_INFO

DMA_OPERATIONS

IoGetDmaAdapter