Porting DMA

[Applies to KMDF only]

Performing DMA (Direct Memory Access) in a KMDF driver is simpler than in a WDM driver because the framework handles many of the details on behalf of the driver.

Basically, the framework-based driver creates a DMA enabler object, specifies the DMA capabilities of the device, and supplies a callback function that manipulates the hardware to perform the transfer.

The framework determines the number of map registers that are required for the transfer, allocates the map registers, builds a scatter/gather list (if the device supports scatter/gather DMA), and flushes the processor cache and the buffers whenever necessary.

For implementation details, see Handling DMA Operations in KMDF Drivers.