xref: /dpdk/doc/guides/bbdevs/fpga_lte_fec.rst (revision 10b71caecbe1cddcbb65c050ca775fba575e88db)
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. The
54default set of bbdev compile flags may be found in config/common_base, where for example
55the flag to build the FPGA LTE FEC device, ``CONFIG_RTE_LIBRTE_PMD_BBDEV_FPGA_LTE_FEC``, is already
56set.
57
58DPDK requires hugepages to be configured as detailed in section 2 of the DPDK manual.
59The bbdev test application has been tested with a configuration 40 x 1GB hugepages. The
60hugepage configuration of a server may be examined using:
61
62.. code-block:: console
63
64   grep Huge* /proc/meminfo
65
66
67Initialization
68--------------
69
70When the device first powers up, its PCI Physical Functions (PF) can be listed through this command:
71
72.. code-block:: console
73
74  sudo lspci -vd1172:5052
75
76The physical and virtual functions are compatible with Linux UIO drivers:
77``vfio`` and ``igb_uio``. However, in order to work the FPGA LTE FEC device firstly needs
78to be bound to one of these linux drivers through DPDK.
79
80
81Bind PF UIO driver(s)
82~~~~~~~~~~~~~~~~~~~~~
83
84Install the DPDK igb_uio driver, bind it with the PF PCI device ID and use
85``lspci`` to confirm the PF device is under use by ``igb_uio`` DPDK UIO driver.
86
87The igb_uio driver may be bound to the PF PCI device using one of three methods:
88
89
901. PCI functions (physical or virtual, depending on the use case) can be bound to
91the UIO driver by repeating this command for every function.
92
93.. code-block:: console
94
95  cd <dpdk-top-level-directory>
96  insmod ./build/kmod/igb_uio.ko
97  echo "1172 5052" > /sys/bus/pci/drivers/igb_uio/new_id
98  lspci -vd1172:
99
100
1012. Another way to bind PF with DPDK UIO driver is by using the ``dpdk-devbind.py`` tool
102
103.. code-block:: console
104
105  cd <dpdk-top-level-directory>
106  ./usertools/dpdk-devbind.py -b igb_uio 0000:06:00.0
107
108where the PCI device ID (example: 0000:06:00.0) is obtained using lspci -vd1172:
109
110
1113. A third way to bind is to use ``dpdk-setup.sh`` tool
112
113.. code-block:: console
114
115  cd <dpdk-top-level-directory>
116  ./usertools/dpdk-setup.sh
117
118  select 'Bind Ethernet/Crypto/Baseband device to IGB UIO module'
119  or
120  select 'Bind Ethernet/Crypto/Baseband device to VFIO module' depending on driver required
121  enter PCI device ID
122  select 'Display current Ethernet/Crypto/Baseband device settings' to confirm binding
123
124
125In the same way the FPGA LTE FEC PF can be bound with vfio, but vfio driver does not
126support SR-IOV configuration right out of the box, so it will need to be patched.
127
128
129Enable Virtual Functions
130~~~~~~~~~~~~~~~~~~~~~~~~
131
132Now, it should be visible in the printouts that PCI PF is under igb_uio control
133"``Kernel driver in use: igb_uio``"
134
135To show the number of available VFs on the device, read ``sriov_totalvfs`` file..
136
137.. code-block:: console
138
139  cat /sys/bus/pci/devices/0000\:<b>\:<d>.<f>/sriov_totalvfs
140
141  where 0000\:<b>\:<d>.<f> is the PCI device ID
142
143
144To enable VFs via igb_uio, echo the number of virtual functions intended to
145enable to ``max_vfs`` file..
146
147.. code-block:: console
148
149  echo <num-of-vfs> > /sys/bus/pci/devices/0000\:<b>\:<d>.<f>/max_vfs
150
151
152Afterwards, all VFs must be bound to appropriate UIO drivers as required, same
153way it was done with the physical function previously.
154
155Enabling SR-IOV via vfio driver is pretty much the same, except that the file
156name is different:
157
158.. code-block:: console
159
160  echo <num-of-vfs> > /sys/bus/pci/devices/0000\:<b>\:<d>.<f>/sriov_numvfs
161
162
163Configure the VFs through PF
164~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
165
166The PCI virtual functions must be configured before working or getting assigned
167to VMs/Containers. The configuration involves allocating the number of hardware
168queues, priorities, load balance, bandwidth and other settings necessary for the
169device to perform FEC functions.
170
171This configuration needs to be executed at least once after reboot or PCI FLR and can
172be achieved by using the function ``fpga_lte_fec_configure()``, which sets up the
173parameters defined in ``fpga_lte_fec_conf`` structure:
174
175.. code-block:: c
176
177  struct fpga_lte_fec_conf {
178      bool pf_mode_en;
179      uint8_t vf_ul_queues_number[FPGA_LTE_FEC_NUM_VFS];
180      uint8_t vf_dl_queues_number[FPGA_LTE_FEC_NUM_VFS];
181      uint8_t ul_bandwidth;
182      uint8_t dl_bandwidth;
183      uint8_t ul_load_balance;
184      uint8_t dl_load_balance;
185      uint16_t flr_time_out;
186  };
187
188- ``pf_mode_en``: identifies whether only PF is to be used, or the VFs. PF and
189  VFs are mutually exclusive and cannot run simultaneously.
190  Set to 1 for PF mode enabled.
191  If PF mode is enabled all queues available in the device are assigned
192  exclusively to PF and 0 queues given to VFs.
193
194- ``vf_*l_queues_number``: defines the hardware queue mapping for every VF.
195
196- ``*l_bandwidth``: in case of congestion on PCIe interface. The device
197  allocates different bandwidth to UL and DL. The weight is configured by this
198  setting. The unit of weight is 3 code blocks. For example, if the code block
199  cbps (code block per second) ratio between UL and DL is 12:1, then the
200  configuration value should be set to 36:3. The schedule algorithm is based
201  on code block regardless the length of each block.
202
203- ``*l_load_balance``: hardware queues are load-balanced in a round-robin
204  fashion. Queues get filled first-in first-out until they reach a pre-defined
205  watermark level, if exceeded, they won't get assigned new code blocks..
206  This watermark is defined by this setting.
207
208  If all hardware queues exceeds the watermark, no code blocks will be
209  streamed in from UL/DL code block FIFO.
210
211- ``flr_time_out``: specifies how many 16.384us to be FLR time out. The
212  time_out = flr_time_out x 16.384us. For instance, if you want to set 10ms for
213  the FLR time out then set this setting to 0x262=610.
214
215
216An example configuration code calling the function ``fpga_lte_fec_configure()`` is shown
217below:
218
219.. code-block:: c
220
221  struct fpga_lte_fec_conf conf;
222  unsigned int i;
223
224  memset(&conf, 0, sizeof(struct fpga_lte_fec_conf));
225  conf.pf_mode_en = 1;
226
227  for (i = 0; i < FPGA_LTE_FEC_NUM_VFS; ++i) {
228      conf.vf_ul_queues_number[i] = 4;
229      conf.vf_dl_queues_number[i] = 4;
230  }
231  conf.ul_bandwidth = 12;
232  conf.dl_bandwidth = 5;
233  conf.dl_load_balance = 64;
234  conf.ul_load_balance = 64;
235
236  /* setup FPGA PF */
237  ret = fpga_lte_fec_configure(info->dev_name, &conf);
238  TEST_ASSERT_SUCCESS(ret,
239      "Failed to configure 4G FPGA PF for bbdev %s",
240      info->dev_name);
241
242
243Test Application
244----------------
245
246BBDEV provides a test application, ``test-bbdev.py`` and range of test data for testing
247the functionality of FPGA LTE FEC turbo encode and turbo decode, depending on the device's
248capabilities. The test application is located under app->test-bbdev folder and has the
249following options:
250
251.. code-block:: console
252
253  "-p", "--testapp-path": specifies path to the bbdev test app.
254  "-e", "--eal-params"	: EAL arguments which are passed to the test app.
255  "-t", "--timeout"	: Timeout in seconds (default=300).
256  "-c", "--test-cases"	: Defines test cases to run. Run all if not specified.
257  "-v", "--test-vector"	: Test vector path (default=dpdk_path+/app/test-bbdev/test_vectors/bbdev_null.data).
258  "-n", "--num-ops"	: Number of operations to process on device (default=32).
259  "-b", "--burst-size"	: Operations enqueue/dequeue burst size (default=32).
260  "-l", "--num-lcores"	: Number of lcores to run (default=16).
261  "-i", "--init-device" : Initialise PF device with default values.
262
263
264To execute the test application tool using simple turbo decode or turbo encode data,
265type one of the following:
266
267.. code-block:: console
268
269  ./test-bbdev.py -c validation -n 64 -b 8 -v ./turbo_dec_default.data
270  ./test-bbdev.py -c validation -n 64 -b 8 -v ./turbo_enc_default.data
271
272
273The test application ``test-bbdev.py``, supports the ability to configure the PF device with
274a default set of values, if the "-i" or "- -init-device" option is included. The default values
275are defined in test_bbdev_perf.c as:
276
277- VF_UL_QUEUE_VALUE 4
278- VF_DL_QUEUE_VALUE 4
279- UL_BANDWIDTH 3
280- DL_BANDWIDTH 3
281- UL_LOAD_BALANCE 128
282- DL_LOAD_BALANCE 128
283- FLR_TIMEOUT 610
284
285
286Test Vectors
287~~~~~~~~~~~~
288
289In addition to the simple turbo decoder and turbo encoder tests, bbdev also provides
290a range of additional tests under the test_vectors folder, which may be useful. The results
291of these tests will depend on the FPGA LTE FEC capabilities:
292
293* turbo decoder tests:
294   - ``turbo_dec_c1_k6144_r0_e10376_crc24b_sbd_negllr_high_snr.data``
295   - ``turbo_dec_c1_k6144_r0_e10376_crc24b_sbd_negllr_low_snr.data``
296   - ``turbo_dec_c1_k6144_r0_e34560_negllr.data``
297   - ``turbo_dec_c1_k6144_r0_e34560_sbd_negllr.data``
298   - ``turbo_dec_c2_k3136_r0_e4920_sbd_negllr_crc24b.data``
299   - ``turbo_dec_c2_k3136_r0_e4920_sbd_negllr.data``
300
301
302* turbo encoder tests:
303   - ``turbo_enc_c1_k40_r0_e1190_rm.data``
304   - ``turbo_enc_c1_k40_r0_e1194_rm.data``
305   - ``turbo_enc_c1_k40_r0_e1196_rm.data``
306   - ``turbo_enc_c1_k40_r0_e272_rm.data``
307   - ``turbo_enc_c1_k6144_r0_e18444.data``
308   - ``turbo_enc_c1_k6144_r0_e32256_crc24b_rm.data``
309   - ``turbo_enc_c2_k5952_r0_e17868_crc24b.data``
310   - ``turbo_enc_c3_k4800_r2_e14412_crc24b.data``
311   - ``turbo_enc_c4_k4800_r2_e14412_crc24b.data``
312