2. NXP DPAA DMA Driver

The DPAA DMA is an implementation of the dmadev APIs, that provide means to initiate a DMA transaction from CPU. The initiated DMA is performed without CPU being involved in the actual DMA transaction. This is achieved via using the QDMA controller of DPAA SoC.

The QDMA controller transfers blocks of data between one source and one destination. The blocks of data transferred can be represented in memory as contiguous or noncontiguous using scatter/gather table(s).

More information can be found at NXP Official Website.

2.1. Supported DPAA SoCs

  • LS1046A

  • LS1043A

2.2. Prerequisites

See NXP QorIQ DPAA Board Support Package for setup information

Note

Some part of dpaa bus code (qbman and fman - library) routines are dual licensed (BSD & GPLv2), however they are used as BSD in DPDK in userspace.

2.3. Compilation

For builds using meson and ninja, the driver will be built when the target platform is dpaa-based. No additional compilation steps are necessary.

RTE_DMA_DPAA_ERRATA_ERR050757

Enable software workaround for Errata-A050757

RTE_DMA_DPAA_ERRATA_ERR050265

Enable software workaround for Errata-A050265

2.4. Initialization

On EAL initialization, DPAA DMA devices will be detected on DPAA bus and will be probed and populated into their device list.

2.5. Features

The DPAA DMA implements following features in the dmadev API:

  • Supports 1 virtual channel.

  • Supports all 4 DMA transfers: MEM_TO_MEM, MEM_TO_DEV, DEV_TO_MEM, DEV_TO_DEV.

  • Supports DMA silent mode.

  • Supports issuing DMA of data within memory without hogging CPU while performing DMA operation.

  • Supports statistics.

2.6. Platform Requirement

DPAA DMA driver for DPDK can only work on NXP SoCs as listed in the Supported DPAA SoCs.

2.7. Device Arguments

dpaa_dma_err_check=1

Check DMA errors at driver level. Usage example: dpaa_bus:dpaa_qdma-1,dpaa_dma_err_check=1