DPAA2 Ethernet configuration¶
The DPAA2 network complex is somewhat unique as the resources available are not "hardwired" - they can be connected dynamically to achieve various scenarios, such as connecting certain ports to virtual machines or to accelerators such as the AIOP.
DPAA2 can be complicated to understand - what is presented here is an attempt to simplify it for those looking to use it with standard Linux network interfaces.
For a more in depth overview of DPAA2 technologies, see DPAA2 overview
Terms you need to know:¶
MC: Management Complex
This is the internal engine in the DPAA2 complex which manages the DPAA2 objects, and abstracts many of the low level details away from the operating system.
DPC: Data path configuration file
The data path configuration file sets out the hardware resources available - most users do not need to touch this file.
DPL: Data path layout file
The DPL sets up the connections between resources in the DPAA2 complex - practically this is where MACs are connected to the network controllers.
DPNI: Data path network interface
This is most analogous to an "eth" interface in Linux
DPMAC: Data path MAC:
This is the "front" end of an Ethernet interface - what connects to the PHY.
DPIO: Data path I/O
This is the operating system interface to the data plane - all frames are transmitted and received through a DPIO object. The LS1088 has eight DPIO objects available so the processing of frames can be spread across all cores.
The simplest configuration is to connect each DPNI to a DPMAC.
Other end point for DPNI's exist such as DPDMUX or DPSW in the larger SoCs (LS/LX2XXX) - for more information on these, please see the NXP documentation.
The default configuration (eth-dpl-all)¶
|MAC name||Device||Name on Panel||Linux Interface Name (10 port config)|
In U-Boot, these will be prefixed based on the interconnect type, e.g 'DPMAC6@qsgmii' for VSC8514 and 'DPMAC1@xgmii' for SFP+
The default DPC and DPL configuration is provided in the firmware builder repository.
Ten64 ships with a configuration that makes all 10 ethernet ports available. However, this is a compromise configuration that stretches the resources in the LS1088 - if you don't need all 10 interfaces it is a good idea to remove any you are not using.
(Up to nine interfaces can be supported without compromising the internal resources in the LS1088)
Boot time set up and deployment¶
To get working network interfaces the following steps need to happen, at the bootloader stage:
- Load the MC firmware and DPC file into memory and then start the management complex For example (when U-Boot is loaded from QSPI):
mcinitcmd=sf probe 0:0;sf read 0x80000000 0x300000 0x200000;sf read 0x80100000 0x5C0000 0x40000;fsl_mc start mc 0x80000000 0x80100000
- Read the DPL file and (lazy)apply it:
sf read 0x80001000 0x580000 0x40000 && fsl_mc lazyapply dpl 0x80001000
Lazyapply delays the application of the DPL until the hand off to Linux, so you can still use the network interfaes in U-Boot.
You can also leave DPNI's and DPMAC's unconfigured in the DPL and connect them at runtime using restool.
Resource object dependencies¶
Each network interface (DPNI) requires a certain number of dependent objects (such as DPMCPs or DPCONs).
A full overview can be found in NXP's DPAA2 objects dependencies, which can be summarized as:
- Each DPNI requires a DPBP and DPMCP, plus N * DPCON where
Nis the number of receive queues.
- Each DPMAC being controlled by an operating system requires one DPMCP
- One DPIO is required per CPU core, and each DPIO requires a DPMCP.
DPAA2 requires a portion of host memory to function, on the Ten64 we use the lowest amount by default (around ~700MiB). If you use AIOP or push high amounts of packets, you may need to adjust this using the "mcmemsize" variable in U-Boot. A reboot is required for changes to "mcmemsize" to take effect.
See README.lsch3 in U-Boot for more details on the MC memory reservation.
As a guide, NXP sets a default of "mcmemsize=0x70000000" (1.75GiB) on the developer boards.
Layerscape SDK User Guide chapter 8.3 (DPAA2-specific Software) Embedded in the SDK user guide is the following (use the 'Attachments' tab in Acrobat Reader to access):
- DPAA2 user manual
- DPAA2 API reference
- AIOP User manual
- AIOP Service Layer reference