WDC_DMAReservedBufLock()

DWORD DLLCALLCONV WDC_DMAReservedBufLock	(	_In_ WDC_DEVICE_HANDLE	hDev,
		_In_ PHYS_ADDR	qwAddr,
		_Outptr_ PVOID *	ppBuf,
		_In_ DWORD	dwOptions,
		_In_ DWORD	dwDMABufSize,
		_Outptr_ WD_DMA **	ppDma
	)

Locks a physical reserved memory buffer for DMA and returns the corresponding user mode address of locked DMA buffer.

Parameters

[in]	hDev	Handle to a WDC device, returned by WDC_xxxDeviceOpen()
[in]	qwAddr	Physical address of the reserved buffer to lock
[out]	ppBuf	Pointer to a pointer to be filled by the function with the user-mode mapped address of the locked DMA buffer
[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_64BIT_ADDRESS: Allow allocation of 64-bit DMA addresses. This flag is supported on Windows and Linux.
[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_DMABufUnlock() when the DMA buffer is no longer needed.

Returns

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

For more detailed usage of the WDC_DMA functions, please refer to 11.2. Performing Direct Memory Access (DMA)