3. NXP DPAA2 QDMA Driver

The DPAA2 QDMA is an implementation of the dmadev API, 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 DPDMAI device exposed by MC.

More information can be found at NXP Official Website.

3.1. Features

The DPAA2 QDMA implements following features in the dmadev API;

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

  • Supports configuring to optionally get status of the DMA translation on per DMA operation basis.

  • Supports statistics.

3.2. Supported DPAA2 SoCs

  • LX2160A

  • LS2084A/LS2044A

  • LS2088A/LS2048A

  • LS1088A/LS1048A

3.3. Prerequisites

See NXP QorIQ DPAA2 Board Support Package for setup information

Note

Some part of fslmc bus code (mc flib - object library) routines are dual licensed (BSD & GPLv2).

3.4. Enabling logs

For enabling logs, use the following EAL parameter:

./your_qdma_application <EAL args> --log-level=pmd.dma.dpaa2.qdma,<level>

Using pmd.dma.dpaa2.qdma as log matching criteria, all Event PMD logs can be enabled which are lower than logging level.

3.5. Initialization

The DPAA2 QDMA is exposed as a dma device which consists of dpdmai devices. On EAL initialization, dpdmai devices will be probed and populated into the dmadevices. The dmadev ID of the device can be obtained using

  • Invoking rte_dma_get_dev_id_by_name("dpdmai.x") from the application where x is the object ID of the DPDMAI object created by MC. Use can use this index for further rawdev function calls.

3.5.1. Platform Requirement

DPAA2 drivers for DPDK can only work on NXP SoCs as listed in the Supported DPAA2 SoCs.

3.6. Device Arguments

fle_pre_populate=1

Pre-populate all DMA descriptors with pre-initialized values. Usage example: fslmc:dpdmai.1,fle_pre_populate=1

desc_debug=1

Enable descriptor debugs. Usage example: fslmc:dpdmai.1,desc_debug=1

short_fd=1

Enable short FDs. Usage example: fslmc:dpdmai.1,short_fd=1