xref: /dpdk/doc/guides/bbdevs/fpga_lte_fec.rst (revision 33f32941ee509f3b66c0c51c44a0288b9c4eec5b)
1..  SPDX-License-Identifier: BSD-3-Clause
2    Copyright(c) 2019 Intel Corporation
3
4Intel(R) FPGA LTE FEC Poll Mode Driver
5======================================
6
7The BBDEV FPGA LTE FEC poll mode driver (PMD) supports an FPGA implementation of a VRAN
8Turbo Encode / Decode LTE wireless acceleration function, using Intel's PCI-e and FPGA
9based Vista Creek device.
10
11Features
12--------
13
14FPGA LTE FEC PMD supports the following features:
15
16- Turbo Encode in the DL with total throughput of 4.5 Gbits/s
17- Turbo Decode in the UL with total throughput of 1.5 Gbits/s assuming 8 decoder iterations
18- 8 VFs per PF (physical device)
19- Maximum of 32 UL queues per VF
20- Maximum of 32 DL queues per VF
21- PCIe Gen-3 x8 Interface
22- MSI-X
23- SR-IOV
24
25
26FPGA LTE FEC PMD supports the following BBDEV capabilities:
27
28* For the turbo encode operation:
29   - ``RTE_BBDEV_TURBO_CRC_24B_ATTACH`` :  set to attach CRC24B to CB(s)
30   - ``RTE_BBDEV_TURBO_RATE_MATCH`` :  if set then do not do Rate Match bypass
31   - ``RTE_BBDEV_TURBO_ENC_INTERRUPTS`` :  set for encoder dequeue interrupts
32
33
34* For the turbo decode operation:
35   - ``RTE_BBDEV_TURBO_CRC_TYPE_24B`` :  check CRC24B from CB(s)
36   - ``RTE_BBDEV_TURBO_SUBBLOCK_DEINTERLEAVE`` :  perform subblock de-interleave
37   - ``RTE_BBDEV_TURBO_DEC_INTERRUPTS`` :  set for decoder dequeue interrupts
38   - ``RTE_BBDEV_TURBO_NEG_LLR_1_BIT_IN`` :  set if negative LLR encoder i/p is supported
39   - ``RTE_BBDEV_TURBO_DEC_TB_CRC_24B_KEEP`` :  keep CRC24B bits appended while decoding
40
41
42Limitations
43-----------
44
45FPGA LTE FEC does not support the following:
46
47- Scatter-Gather function
48
49
50Installation
51--------------
52
53Section 3 of the DPDK manual provides instructions on installing and compiling DPDK.
54
55DPDK requires hugepages to be configured as detailed in section 2 of the DPDK manual.
56The bbdev test application has been tested with a configuration 40 x 1GB hugepages. The
57hugepage configuration of a server may be examined using:
58
59.. code-block:: console
60
61   grep Huge* /proc/meminfo
62
63
64Initialization
65--------------
66
67When the device first powers up, its PCI Physical Functions (PF) can be listed through this command:
68
69.. code-block:: console
70
71  sudo lspci -vd1172:5052
72
73The physical and virtual functions are compatible with Linux UIO drivers:
74``vfio_pci`` and ``igb_uio``. However, in order to work the FPGA LTE FEC device firstly needs
75to be bound to one of these linux drivers through DPDK.
76
77For more details on how to bind the PF device and create VF devices, see
78:ref:`linux_gsg_binding_kernel`.
79
80
81Configure the VFs through PF
82~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
83
84The PCI virtual functions must be configured before working or getting assigned
85to VMs/Containers. The configuration involves allocating the number of hardware
86queues, priorities, load balance, bandwidth and other settings necessary for the
87device to perform FEC functions.
88
89This configuration needs to be executed at least once after reboot or PCI FLR and can
90be achieved by using the function ``rte_fpga_lte_fec_configure()``, which sets up the
91parameters defined in ``rte_fpga_lte_fec_conf`` structure:
92
93.. code-block:: c
94
95  struct rte_fpga_lte_fec_conf {
96      bool pf_mode_en;
97      uint8_t vf_ul_queues_number[FPGA_LTE_FEC_NUM_VFS];
98      uint8_t vf_dl_queues_number[FPGA_LTE_FEC_NUM_VFS];
99      uint8_t ul_bandwidth;
100      uint8_t dl_bandwidth;
101      uint8_t ul_load_balance;
102      uint8_t dl_load_balance;
103      uint16_t flr_time_out;
104  };
105
106- ``pf_mode_en``: identifies whether only PF is to be used, or the VFs. PF and
107  VFs are mutually exclusive and cannot run simultaneously.
108  Set to 1 for PF mode enabled.
109  If PF mode is enabled all queues available in the device are assigned
110  exclusively to PF and 0 queues given to VFs.
111
112- ``vf_*l_queues_number``: defines the hardware queue mapping for every VF.
113
114- ``*l_bandwidth``: in case of congestion on PCIe interface. The device
115  allocates different bandwidth to UL and DL. The weight is configured by this
116  setting. The unit of weight is 3 code blocks. For example, if the code block
117  cbps (code block per second) ratio between UL and DL is 12:1, then the
118  configuration value should be set to 36:3. The schedule algorithm is based
119  on code block regardless the length of each block.
120
121- ``*l_load_balance``: hardware queues are load-balanced in a round-robin
122  fashion. Queues get filled first-in first-out until they reach a pre-defined
123  watermark level, if exceeded, they won't get assigned new code blocks..
124  This watermark is defined by this setting.
125
126  If all hardware queues exceeds the watermark, no code blocks will be
127  streamed in from UL/DL code block FIFO.
128
129- ``flr_time_out``: specifies how many 16.384us to be FLR time out. The
130  time_out = flr_time_out x 16.384us. For instance, if you want to set 10ms for
131  the FLR time out then set this setting to 0x262=610.
132
133
134An example configuration code calling the function ``rte_fpga_lte_fec_configure()`` is shown
135below:
136
137.. code-block:: c
138
139  struct rte_fpga_lte_fec_conf conf;
140  unsigned int i;
141
142  memset(&conf, 0, sizeof(struct rte_fpga_lte_fec_conf));
143  conf.pf_mode_en = 1;
144
145  for (i = 0; i < FPGA_LTE_FEC_NUM_VFS; ++i) {
146      conf.vf_ul_queues_number[i] = 4;
147      conf.vf_dl_queues_number[i] = 4;
148  }
149  conf.ul_bandwidth = 12;
150  conf.dl_bandwidth = 5;
151  conf.dl_load_balance = 64;
152  conf.ul_load_balance = 64;
153
154  /* setup FPGA PF */
155  ret = rte_fpga_lte_fec_configure(info->dev_name, &conf);
156  TEST_ASSERT_SUCCESS(ret,
157      "Failed to configure 4G FPGA PF for bbdev %s",
158      info->dev_name);
159
160
161Test Application
162----------------
163
164BBDEV provides a test application, ``test-bbdev.py`` and range of test data for testing
165the functionality of the device, depending on the device's capabilities.
166
167For more details on how to use the test application,
168see :ref:`test_bbdev_application`.
169
170Test Vectors
171~~~~~~~~~~~~
172
173In addition to the simple turbo decoder and turbo encoder tests, bbdev also provides
174a range of additional tests under the test_vectors folder, which may be useful. The results
175of these tests will depend on the FPGA LTE FEC capabilities:
176
177* turbo decoder tests:
178   - ``turbo_dec_c1_k6144_r0_e10376_crc24b_sbd_negllr_high_snr.data``
179   - ``turbo_dec_c1_k6144_r0_e10376_crc24b_sbd_negllr_low_snr.data``
180   - ``turbo_dec_c1_k6144_r0_e34560_negllr.data``
181   - ``turbo_dec_c1_k6144_r0_e34560_sbd_negllr.data``
182   - ``turbo_dec_c2_k3136_r0_e4920_sbd_negllr_crc24b.data``
183   - ``turbo_dec_c2_k3136_r0_e4920_sbd_negllr.data``
184
185
186* turbo encoder tests:
187   - ``turbo_enc_c1_k40_r0_e1190_rm.data``
188   - ``turbo_enc_c1_k40_r0_e1194_rm.data``
189   - ``turbo_enc_c1_k40_r0_e1196_rm.data``
190   - ``turbo_enc_c1_k40_r0_e272_rm.data``
191   - ``turbo_enc_c1_k6144_r0_e18444.data``
192   - ``turbo_enc_c1_k6144_r0_e32256_crc24b_rm.data``
193   - ``turbo_enc_c2_k5952_r0_e17868_crc24b.data``
194   - ``turbo_enc_c3_k4800_r2_e14412_crc24b.data``
195   - ``turbo_enc_c4_k4800_r2_e14412_crc24b.data``
196
197
198Alternate Baseband Device configuration tool
199~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
200
201On top of the embedded configuration feature supported in test-bbdev using "- -init-device"
202option, there is also a tool available to perform that device configuration using a companion
203application.
204The ``pf_bb_config`` application notably enables then to run bbdev-test from the VF
205and not only limited to the PF as captured above.
206
207See for more details: https://github.com/intel/pf-bb-config
208
209Specifically for the BBDEV FPGA LTE FEC PMD, the command below can be used:
210
211.. code-block:: console
212
213  ./pf_bb_config FPGA_LTE -c fpga_lte/fpga_lte_config_vf.cfg
214  ./test-bbdev.py -e="-c 0xff0 -a${VF_PCI_ADDR}" -c validation -n 64 -b 32 -l 1 -v ./turbo_dec_default.data
215