18.5 PCI DMA
There are three types of DMA transactions that can be implemented using the services of the PCI I/O Protocol:
- Bus master read transactions
- Bus master write transactions
- Common buffer transactions
The PCI I/O Protocol services used to manage PCI DMA transactions include:
PciIo->AllocateBuffer()PciIo->FreeBuffer()PciIo->Map()PciIo->Unmap()-PciIo->Flush()