3. HISILICON Kunpeng DMA Driver

Kunpeng SoC has an internal DMA unit which can be used by application to accelerate data copies. The DMA PF function supports multiple DMA channels.

3.1. Supported Kunpeng SoCs

  • Kunpeng 920

3.2. Device Setup

Kunpeng DMA devices will need to be bound to a suitable DPDK-supported user-space IO driver such as vfio-pci in order to be used by DPDK.

3.2.1. Device Probing and Initialization

Once probed successfully, the device will appear as four dmadev which can be accessed using API from the rte_dmadev library.

The name of the dmadev created is like “B:D.F-chX”, e.g. DMA 0000:7b:00.0 will create four dmadev, the 1st dmadev name is “0000:7b:00.0-ch0”, and the 2nd dmadev name is “0000:7b:00.0-ch1”.

3.2.2. Device Configuration

Kunpeng DMA configuration requirements:

  • ring_size must be a power of two, between 32 and 8192.
  • Only one vchan is supported per dmadev.
  • Silent mode is not supported.
  • The transfer direction must be set to RTE_DMA_DIR_MEM_TO_MEM.