- modify retrieve_ldpc_enc_op() to store encoded results in a packed format
- add timing measurements for T2 encoder
- add simde implementation for bit reversal
- Introduce new bit reversal implementation using simde_mm_gf2p8affine_epi64_epi8
instruction, based on https://wunkolo.github.io/post/2020/11/gf2p8affineqb-bit-reversal/.
This implementation requires GFNI and AVX512VL support on the target machine.
1. The encoder writes the output in sequence after the encoding tasks completed instead of writing within the tasks.
2. Simplify the output writing to make it more readable.
Co-authored-by: Laurent Thomas <laurent.thomas@open-cells.com>
There was a risk of a race condition between encoding tasks on the output array.
It could be that two task compete in writing a word at the border of their respective segment groups.
This commit offers to solve this issue by retaining the tail word in a struct that is returned after task completion so that segment group border can be fixed after completion of all the tasks.
Comes with additional cleanups of nrLDPC_coding_segment_encoder:
1. Move the section of code dedicated to writing to the encoding library output to a separate function.
2. Remove bit interleave debug in AVX512VBMI case of output writing for improving code readability.
1. nrLDPC_coding_segment_encoding: Clarifying encoder parameters
The way the encoder implementation params was used could be made clearer:
* `macro_num` was always used in order to calculate segment indexes.
It is clearer to pass directly the first segment index.
* The initialisation of a common implementation parameters structure can be made clearer.
2. nrLDPC_coding_segment_encoder: Remove multi segment dimension in encoder output
The output of `LDPCencoder` was a 2D unsigned char array.
But all the segments were actually packed in the first segment, 8 bits of different segments per byte of the first segment.
So the first dimension was useless. This commit removes this dimension.
3. nrLDPC_coding_segment_encoder: Rename `nrLDPC_prepare_TB_encoding` into `nrLDPC_launch_TB_encoding`
4. nrLDPC_coding_segment_encoder: Remove the useless second rate matching for E2, one rate matching with max(E, E2) does the job.
5. nr_interleaving_ldpc: cleanup
Rewrite code to use different SIMD sizes in a linear fashion.
This means cascading preprocessor directives are used to start from a high SIMD size an decrease it progressively.
6. ldpc_encoder_optim8segmulti: linear usage of SIMD
Use cascading preprocessor directives to include different SIMD sizes and types depending on which are available on the system.
The different loops use a common index that is progressively incremented.
Also add AVX512 version of bits distribution from 8 segments into one byte.
Co-authored-by: Laurent Thomas <laurent.thomas@open-cells.com>
Since this branch aims to bring all the encoded segments packed and contiguous,
it doesn't make anymore sense to have one output array per segment.
Therefore this commit moves the output array to the TB instead of the segment and adapts its size.
TODO: Adapt the size of f where it is relevant.
1. nrLDPC_coding_segment_encoder: pointer not aligned on 64 bits
An undefined behavior was happening because of a shift on a __m64 which
was actually a uint32_t which was not aligned on 64 bits.
This commit suggests a fix by properly loading into a __m64 with _mm_set_pi32
before performing the shift.
2. nr_rate_matching: Filler bits detection
Previously, if the bit selection was reaching Ncb and restarting selection from the beginning of encoded data, the filler bits were detected by testing the bytes again NR_NULL which was equal to 2.
But on this branch the bits of up to 8 segments are stored in one byte while doing rate matching so that one byte could be tested to be a filler while it is not.
So this commit changes the way to test filler bits.
Instead of relying on NR_NULL, bit selection now relies on the offset and size of filler bits.
3. nr_ulsch_coding: missing filling f with zeros
The array `f` of the UE UL HARQ process was not filled with zeros between transmissions.
This is a problem if the encoder does not properly overwrite its output.
In order to avoid such situation, this commit adds a memset to fill `f` with zeros before passing it to the encoder.
4. nrLDPC_coding_segment_encoder: missing init of f to zeros
In the encoder, `f` is not filled with zeros before being used.
`f` is instead somehow filled with arbitrary values.
When writing to `output` by 64 bit vectors, some arbitrary bits may be added after the segment.
Then the arbitrary added ones are not overwritten when writing the next segment because of writing with a logical or.
This commit properly fills `f` and `f2` with zeros.
5. nr_ulschsim & nr_dlschsim: Adapt modulation to new encoder output
The QPSK symbols that are feed to the channel model of nr_dlschsim were determined based on the bytes of the encoder output.
With the new output of the encoder, it had to be reworked to determine the QPSK symbols based on the bits of the encoder output.
1. 3GPP Rate-matching/interleaving on 8-segment blocks, deinterleaving at output of multi-segment processing.
2. Bit-packing done in nrLDPC_coding_segment_encoder.c now instead of nr_scrambling.
Interestingly, it improves performance significantly too.
Tested for AVX512 only for now.
Avoid the use of simde_mm_sign_epi8 which is inefficient on aarch64.
Decoding times are significantly improved on aarch64.
Co-authored-by: Romain Beurdouche <romain.beurdouche@eurecom.fr>
Integration: `2025.w18`
Closes#953
See merge request oai/openairinterface5g!3413
* !3385 Add enc/dec lib for E1 Bearer Context Setup Failure
* !3410 Avoid segmentation fault when testing trigger reestablishment and there is no DRB[0] established
* !3411 Remove assert for SRI-PUSCH-PowerControl
* !3291 Improvements in handling UE context in gNB DU
* !3416 Signal gNB-DU config update CellStatus from DU to CU
* patch to fix memory leak on DRB_ToAddModList
* update phytest-timing thresholds
Signal gNB-DU config update CellStatus from DU to CU
Add the cell status to gNB-DU configuration update message, including
test. Use the gNB-DU configuration update to signal the cell status in
the stack.
This IE was not included in a previous refactoring round, but is at
least necessary to be decoded when interoperating with the OSC O-DU.
Improvements in handling UE context in gNB DU
The goal of this MR is to improve the handling of UE context in gNB DU.
To achieve this goal, the UE structure is created as soon as the gNB
receive a PRACH indication. At that stage the UE is placed in a new
structure containing UEs performing RA, untill RA is complete where it
is moved to the list of connected UEs. To simplify the code and to
improve the handling of initial procedures (see #751), DCI 10 and DCI 00
is used at every stage until the DU receives from CU the indication of
UE RRC reconfiguration being completed.
Remove assert for SRI-PUSCH-PowerControl
SRI-PUSCH-PowerControl is not implemented at this point but its enough
to warn about incorrect power control behavior rather than assert on the
configuration.
Closes#953
This is preparatory work to allow NSA-like modes to be used over F1 in
the future. Notably, it fills the F1 message for UE context setup with
GTP TEID, and fills additional information to "make the F1 encoder
happy" (fill in QFI etc). Also, provide some F1 fixes to make this work.
Remove stale UE connections, if relevant.
sdap_tun_read_thread needs to know if we are gNB/UE. Previously, we
passed this into the thread, but the next commit also needs to for
interface termination, where this info is not available. So, for noS1
mode, pass this in.
Add functionality to trigger the addition of a new RRC UE context (in
the CU) for NSA modes, using F1. This commit makes do-ra and phy-test
modes work. "True" NSA will work in the next commit, which also sends
the X2 addition request answer message.
Use the gNB-DU configuration update to signal the cell status in the
stack. At the DU, modify the code to always send this message --
previously, we only sent this message if a SIB1 update was necessary,
but now it's always, only including SIB1 updates if necessary.
At the CU, as we don't really have a use as of now, print the
information, but don't do anything with it.
Add enc/dec lib for E1 Bearer Context Setup Failure
This MR is adding:
- the enc/dec library
- unit test
- handler and callback in stack
For the E1 Bearer Context Setup Failure.
- rewrite add_UE_to_list() and rewrite remove_UE_from_list() to simplify
list handling
- return pointer from get_new_nr_ue_inst(); it's completely freed by
delete_nr_ue_data()
- have add_new_UE_RA() add UE context to access list; remove with
nr_release_ra_UE()
- have add_connected_nr_ue() only add UE to connected list; to move from
access to connected use transition_ra_connected_nr_ue(); remove with
mac_remove_nr_ue() as previously
- free memory on problems during RA
- add some documentation
- in NSA/HO: check for pre-configured RA process
- there are asserts in all functions to clarify when a UE has RA
Romain Beurdouche