..  SPDX-License-Identifier: BSD-3-Clause
    Copyright(c) 2017 Intel Corporation

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.

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``


Limitations
-----------

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

Installation
------------

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.

FlexRAN SDK Installation
~~~~~~~~~~~~~~~~~~~~~~~~

The following are pre-requisites for building FlexRAN SDK Libraries:
 (a) An AVX2 supporting machine
 (b) Windriver TS 2 or CentOS 7 operating systems
 (c) Intel ICC compiler installed

The following instructions should be followed in this exact order:

#. Set the environment variables:

    .. code-block:: console

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


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

    .. code-block:: console

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

#. 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.

    .. code-block:: c

        -  return 1;
        +  return 0;

#. Generate makefiles based on system configuration:

    .. code-block:: console

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

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

    .. code-block:: console

        cd build-avx2-icc/
        make install


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:

.. code-block:: console

    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``).

Example:
~~~~~~~~

.. code-block:: console

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