A basic DMA transfer works a bit like this: the CPU sets up a transfer by telling the DMA controller what address to start reading at, what address to start writing at, and how much data to copy.

With DMA, peripheral devices do not have to ask the CPU to fetch some data for them, but can do it themselves. Unfortunately, this means multiple systems vying for the same memory pool’s content ...

For any DMA transfer, the first problem to consider is the user may request a large transfer (kilobytes to megabytes) ... , enum dma_data_direction dir); where the arguments are identical to dma_unmap ...

This allows the DMA data transfer to occur in parallel with CPU processing. This process is illustrated in Figure 10. The DMA transfer in is started to fill InBuffB. The CPU processes data in InBuffA.

For memory-intensive and high-performance computing, direct memory access (DMA) is indispensable. A typical DMA operation in PCI Express (PCIe) entails the transfer of data from the system memory to ...