WDC_DMATransactionSGInit()

DWORD DLLCALLCONV WDC_DMATransactionSGInit	(	_In_ WDC_DEVICE_HANDLE	hDev,
		_In_ PVOID	pBuf,
		_In_ DWORD	dwOptions,
		_In_ DWORD	dwDMABufSize,
		_Outptr_ WD_DMA **	ppDma,
		_In_ WDC_INTERRUPT_PARAMS *	pInterruptParams,
		_In_ DWORD	dwMaxTransferSize,
		_In_ DWORD	dwTransferElementSize
	)

Initializes the transaction and locks a pre-allocated user-mode memory buffer for DMA.

Parameters

[in]	hDev	Handle to a WDC device, returned by WDC_xxxDeviceOpen()
[in]	pBuf	Pointer to a user-mode buffer to be mapped to the allocated physical DMA buffer(s).
[in]	dwOptions	A bit mask of any of the following flags (defined in an enumeration in windrvr.h): DMA_FROM_DEVICE: Synchronize the DMA buffer for transfers from the device to memory. DMA_TO_DEVICE: Synchronize the DMA buffer for transfers from memory to the device. DMA_TO_FROM_DEVICE: Synchronize the DMA buffer for transfers in both directions i.e., from the device to memory and from memory to the device (<=> DMA_FROM_DEVICE | DMA_TO_DEVICE). DMA_ALLOW_CACHE: Allow caching of the memory. DMA_ALLOW_64BIT_ADDRESS: Allow allocation of 64-bit DMA addresses.
[in]	dwDMABufSize	The size (in bytes) of the DMA buffer.
[out]	ppDma	Pointer to a pointer to a DMA buffer information structure, which is allocated by the function. The pointer to this structure (*ppDma) should be passed to WDC_DMATransactionUninit() when the DMA buffer is no longer needed.
[in]	pInterruptParams	WDC_DMATransactionSGInit() invokes WDC_IntEnable() with the relevant parameters from the structure (WDC_INTERRUPT_PARAMS). No action will be taken if this parameter is NULL.
[in]	dwMaxTransferSize	The maximum size for each of the transfers.
[in]	dwTransferElementSize	The size (in bytes) of the DMA transfer element (descriptor).

Returns

Returns WD_STATUS_SUCCESS (0) on success, or an appropriate error code otherwise

For more detailed usage of the WDC_DMA Transactions functions, please refer to 11.3. Performing Direct Memory Access (DMA) transactions