2. SW Turbo Poll Mode Driver

The SW Turbo PMD (turbo_sw) provides a poll mode bbdev driver that utilizes Intel optimized libraries for LTE Layer 1 workloads acceleration. This PMD supports the functions: Turbo FEC, Rate Matching and CRC functions.

2.1. Features

SW Turbo PMD has support for the following capabilities:

For the encode operation:

  • RTE_BBDEV_TURBO_CRC_24A_ATTACH
  • RTE_BBDEV_TURBO_CRC_24B_ATTACH
  • RTE_BBDEV_TURBO_RATE_MATCH
  • RTE_BBDEV_TURBO_RV_INDEX_BYPASS

For the decode operation:

  • RTE_BBDEV_TURBO_SUBBLOCK_DEINTERLEAVE
  • RTE_BBDEV_TURBO_CRC_TYPE_24B
  • RTE_BBDEV_TURBO_POS_LLR_1_BIT_IN
  • RTE_BBDEV_TURBO_NEG_LLR_1_BIT_IN

2.2. Limitations

  • In-place operations for Turbo encode and decode are not supported

2.3. Installation

2.3.1. FlexRAN SDK Download

To build DPDK with the turbo_sw PMD the user is required to download the export controlled FlexRAN SDK Libraries. An account at Intel Resource Design Center needs to be registered from https://www.intel.com/content/www/us/en/design/resource-design-center.html.

Once registered, the user needs to log in, and look for Intel SWA_SW_FlexRAN_Release_Package R1_3_0 and click for download. Or use this direct download link https://cdrd.intel.com/v1/dl/getContent/575367.

After download is complete, the user needs to unpack and compile on their system before building DPDK.

2.3.2. FlexRAN SDK Installation

The following are pre-requisites for building FlexRAN SDK Libraries:
  1. An AVX2 supporting machine
  2. Windriver TS 2 or CentOS 7 operating systems
  3. Intel ICC compiler installed

The following instructions should be followed in this exact order:

  1. Set the environment variables:

    source <path-to-icc-compiler-install-folder>/linux/bin/compilervars.sh intel64 -platform linux

  2. Extract the FlexRAN-1.3.0.tar.gz.zip package, then run the SDK extractor script and accept the license:

    cd <path-to-workspace>/FlexRAN-1.3.0/
./SDK-R1.3.0.sh

  3. To allow FlexRAN SDK R1.3.0 to work with bbdev properly, the following hotfix is required. Change the return of function rate_matching_turbo_lte_avx2() located in file <path-to-workspace>/FlexRAN-1.3.0/SDK-R1.3.0/sdk/source/phy/lib_rate_matching/phy_rate_match_avx2.cpp to return 0 instead of 1.

    -  return 1;
+  return 0;

  4. Generate makefiles based on system configuration:

    cd <path-to-workspace>/FlexRAN-1.3.0/SDK-R1.3.0/sdk/
./create-makefiles-linux.sh

  5. A build folder is generated in this form build-<ISA>-<CC>, enter that folder and install:

    cd build-avx2-icc/
make install

2.4. Initialization

In order to enable this virtual bbdev PMD, the user must:

  • Build the FLEXRAN SDK libraries (explained in Installation section).
  • Export the environmental variables FLEXRAN_SDK to the path where the FlexRAN SDK libraries were installed. And DIR_WIRELESS_SDK to the path where the libraries were extracted.

Example:

export FLEXRAN_SDK=<path-to-workspace>/FlexRAN-1.3.0/SDK-R1.3.0/sdk/build-avx2-icc/install
export DIR_WIRELESS_SDK=<path-to-workspace>/FlexRAN-1.3.0/SDK-R1.3.0/sdk/
  • Set CONFIG_RTE_LIBRTE_PMD_BBDEV_TURBO_SW=y in DPDK common configuration file config/common_base.

To use the PMD in an application, user must:

  • Call rte_vdev_init("turbo_sw") within the application.
  • Use --vdev="turbo_sw" in the EAL options, which will call rte_vdev_init() internally.

The following parameters (all optional) can be provided in the previous two calls:

  • socket_id: Specify the socket where the memory for the device is going to be allocated (by default, socket_id will be the socket where the core that is creating the PMD is running on).
  • max_nb_queues: Specify the maximum number of queues in the device (default is RTE_MAX_LCORE).

2.4.1. Example:

./test-bbdev.py -e="--vdev=turbo_sw,socket_id=0,max_nb_queues=8" \
-c validation -v ./test_vectors/bbdev_vector_t?_default.data