liteeth/test/test_xgmii_phy.py

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#
# This file is part of LiteEth.
#
# Copyright (c) 2021 Leon Schuermann <leon@is.currently.online>
# SPDX-License-Identifier: BSD-2-Clause
import unittest
import random
import csv
from pathlib import Path
from migen import *
from litex.soc.interconnect.stream import *
from liteeth.phy.xgmii import LiteEthPHYXGMII, LiteEthPHYXGMIIRX
from .test_stream import StreamPacket, stream_inserter, stream_collector, \
compare_packets
def mask_last_be(dw, data, last_be):
"""Mark some data by a last_be data qualifier. The rest of the data
passed in will be zeroed.
"""
masked_data = 0
for byte in range(dw // 8):
if 2**byte > last_be:
break
masked_data |= data & (0xFF << (byte * 8))
return masked_data
class XGMIICollector:
def __init__(self, min_interframegap=12, tolerate_dic=True,
debug_print=False):
# Minimum IFG legal to be accepted on the XGMII interface (excluding
# DIC, if tolerated). On the receiving send, when accounting for
# potential IFG shrinkage and allowing the minimum receive IFG as
# mandated by IEEE 802.3 (e.g. `min_interframegap` = 5 bytes IFG for
# 10Gbit/s Ethernet), tolerate_dic should thus be disabled.
self.min_interframegap = min_interframegap
# Whether the collector should spit out debug information about received
# signal states. Will always print error conditions.
self.debug_print = debug_print
# Whether the deficit idle count mechanism should be tolerated. This
# will allow the receiver to temporarily accept IFGs < 12 bytes, as long
# as an average inter-frame gap of >= 12 is maintained. This must be
# implemented as a 2-bit counter, as per IEEE 802.3-2018, section four,
# 46.3.1.4 Start control character alignment.
self.tolerate_dic = tolerate_dic
# Proper deficit idle count, implemented as a two bit counter using the
# algorithm described by Eric Lynskey of the UNH InterOperability
# Lab[1]:
#
# | current | | | | |
# | count | 0 | 1 | 2 | 3 |
# |---------+-----+-------+-----+-------+-----+-------+-----+-------|
# | | | new | | new | | new | | new |
# | pkt % 4 | IFG | count | IFG | count | IFG | count | IFG | count |
# |---------+-----+-------+-----+-------+-----+-------+-----+-------|
# | 0 | 12 | 0 | 12 | 1 | 12 | 2 | 12 | 3 |
# | 1 | 11 | 1 | 11 | 2 | 11 | 3 | 15 | 0 |
# | 2 | 10 | 2 | 10 | 3 | 14 | 0 | 14 | 1 |
# | 3 | 9 | 3 | 13 | 0 | 13 | 1 | 13 | 2 |
#
# [1]: https://www.iol.unh.edu/sites/default/files/knowledgebase/10gec/10GbE_DIC.pdf
self.dic = 0
# How many additional IDLE characters we've seen. We are faithful that
# the device is complying and initialize this to the mandated IFG byte
# count + 3 bytes extra IDLE characters inserted through DIC, in case we
# listen in to a captured stream and a new packet starts immediately.
self.interframegap = 15
# Received packets, array of arrays of bytes.
self.packets = []
# Packet currently being received. Array of bytes.
self.current_packet = None
# History of observed inter-frame gaps for debugging purposes.
self.interframegaps = []
# Whether the collector is currently collecting data or done. This can
# be very useful information for designing composite test systems and
# running until all data has been gathered.
self.collecting = False
def inject_32b_bus_word(self, ctl_word, data_word):
for i in range(4):
ctl = (ctl_word >> i) & 1
data = (data_word >> (i * 8)) & 0xFF
if ctl == 0 and self.current_packet is not None:
# Data byte _and_ currently reading a packet, all fine!
self.current_packet += [data]
elif ctl == 1 and data == 0xFB:
# XGMII start of frame control character
if self.current_packet is not None:
raise ValueError("Got start of frame control character "
+ "while reading packet")
if i != 0:
raise ValueError("Got start of frame control character on "
+ "lane {}".format(i))
# Check and validate the observed IFG
if self.tolerate_dic:
if self.interframegap < self.min_interframegap:
# Produced some deficit, check if it's legal
self.dic += self.min_interframegap - self.interframegap
if self.dic > 3:
raise ValueError("DIC bounds exceeded. Observed {} "
+ "bytes IFG, but DIC would have "
+ "allowed {}.".format(
self.interfamegap,
3 - self.dic))
elif self.interframegap > self.min_interframegap:
# Inserted some extra IDLE, subtract from the deficit
self.dic = min(0, self.dic - (
self.interframegap - self.min_interframegap
))
elif self.interframegap < self.min_interframegap:
# DIC is disabled
raise ValueError("IFG violated. Oberserved {} bytes, which "
+ "is less than the minimum of {}".format(
self.interframegap,
self.min_interframegap
))
# Store the observed IFG for debugging purposes and reset it
self.interframegaps += [self.interframegap]
self.interframegap = 0
# Start a new packet. The XGMII start of frame character
# replaces the first preamble octet, so store that as the first
# byte.
self.current_packet = [0x55]
elif ctl == 1 and data == 0xFD:
# XGMII end of frame control character
if self.current_packet is None:
if len(self.packets) == 0 and self.debug_print:
print("INFO: got end of frame control character while "
+ "not reading a packet. This can be valid for "
+ "the first partial packet in the capture, but "
+ "not afterwards.")
elif len(self.packets) != 0:
raise ValueError("Got end of frame control character "
+ "while not reading a packet.")
else:
if self.debug_print:
print("Received XGMII packet {}.".format(
len(self.packets)
))
# Transmission ended, store the packet and reset the current
# packet.
self.packets += [self.current_packet]
self.current_packet = None
# The XGMII end of frame control character does count
# towards the IFG
self.interframegap = 1
# All following bytes MUST be XGMII IDLE control
# characters. We will want to verify that and
# count the number of bytes until i % 4 == 0
# towards the DIC counter.
end_of_frame = True
elif ctl == 1 and data == 0x07:
# XGMII idle control character
if self.current_packet is not None:
raise ValueError("Got idle control character in the middle "
+ "of a packet")
self.interframegap += 1
elif ctl == 1:
# Unrecognized XGMII control character
raise ValueError("Invalid XGMII control character {:02x}"
.format(data))
def inject_bus_word(self, dw, ctl_word, data_word):
if dw == 32:
self.inject_32b_bus_word(ctl_word, data_word)
elif dw == 64:
self.inject_32b_bus_word(
ctl_word & 0xF,
data_word & 0xFFFFFFFF
)
self.inject_32b_bus_word(
(ctl_word >> 4) & 0xF,
(data_word >> 32) & 0xFFFFFFFF,
)
else:
raise ValueError("Unknown data width: {} bits".format(dw))
def collect(self, xgmii_interface, tap_signals="tx", stop_cond=None):
self.collecting = True
# Which signals to attach to in the passed XGMII interface
assert tap_signals in ["tx", "rx"]
if stop_cond is None:
stop_cond = lambda: False
while not stop_cond():
if tap_signals == "tx":
ctl_word = yield xgmii_interface.tx_ctl
data_word = yield xgmii_interface.tx_data
dw = len(xgmii_interface.tx_data)
elif tap_signals == "rx":
ctl_word = yield xgmii_interface.rx_ctl
data_word = yield xgmii_interface.rx_data
dw = len(xgmii_interface.rx_data)
self.inject_bus_word(dw, ctl_word, data_word)
yield
self.collecting = False
class XGMII64bCSVReader:
def __init__(self, filename, extract_signals_pattern="rx",
complete_trailing_transaction=True):
# Whether we should attempt to complete a trailing XGMII transaction by
# inserting an XGMII end control character.
self.complete_trailing_transaction = complete_trailing_transaction
# Store filename for reference
self.filename = filename
# Open the CSV file and create a CSV reader over it
self.filehandle = open(filename, 'r')
self.reader = csv.reader(
# Support comments in the CSV file
filter(lambda line: not line.startswith("#"), self.filehandle),
delimiter=','
)
# Extract the headers and correlate them with the required signal
# pattern to find out the matching columns
self.column_headers = next(self.reader, None)
assert self.column_headers is not None, \
"Failed to load column header row from CSV"
self.rx_ctl_col = None
self.rx_data_col = None
for i, header in enumerate(self.column_headers):
if "{}_ctl".format(extract_signals_pattern) in header:
self.rx_ctl_col = i
elif "{}_data".format(extract_signals_pattern) in header:
self.rx_data_col = i
assert self.rx_ctl_col is not None, \
"Failed to find RX CTL signal column in CSV"
assert self.rx_data_col is not None, \
"Failed to find RX DATA signal column in CSV"
self.datatype_headers = next(self.reader, None)
assert self.datatype_headers is not None, \
"Failed to load data type header row from CSV"
assert self.datatype_headers[self.rx_ctl_col] == "HEX", \
"XGMII CTL signal is not hex-encoded"
assert self.datatype_headers[self.rx_data_col] == "HEX", \
"XGMII DATA signal is not hex-encoded"
# Whether the inserter is currently in the middle of a packet
self.currently_in_packet = False
# Hack around Python not having a peekable iterator by always taking the
# next element at the end of a function.
self.next_row = next(self.reader, None)
# Upper XGMII bus word, for when 32 bit words are accessed
self.upper_ctl = None
self.upper_data = None
def __del__(self):
self.filehandle.close()
def get_64b_bus_word(self):
if self.next_row is None:
return None
ctl_word = int(self.next_row[self.rx_ctl_col], 16)
data_word = int(self.next_row[self.rx_data_col], 16)
new_packet = False
# Detect whether this is just starting a new packet
for i in range(8):
ctl = (ctl_word >> i) & 1
data = (data_word >> (i * 8)) & 0xFF
if ctl == 1 and data == 0xFB:
new_packet = True
self.currently_in_packet = True
if ctl == 1 and data == 0xFD:
self.currently_in_packet = False
# Store for below
prev_row = self.next_row
self.next_row = next(self.reader, None)
# Let's make sure we have now half / dangling packet at the end. If this
# was the last column and we're currently receiving one, make sure we
# end it properly. This might go terribly wrong if this is condition
# aries at the start of a packet though, in this case just throw an
# error.
if self.next_row is None and self.currently_in_packet \
and self.complete_trailing_transaction:
if new_packet:
raise ValueError("CSV ends just at the start of a new packet, "
+ "we can't handle that!")
self.next_row = prev_row
self.next_row[self.rx_ctl_col] = "ff"
self.next_row[self.rx_data_col] = "07070707070707fd"
return (ctl_word, data_word)
def get_bus_word(self, dw=64):
if dw == 64:
assert self.upper_data is None and self.upper_ctl is None, \
"Cannot query 32bit and 64bit bus words interchangeably"
return self.get_64b_bus_word()
elif dw == 64:
if self.upper_data is not None:
assert self.upper_ctl is not None
return (self.upper_ctl, self.upper_data)
else:
xgmii_64b = self.get_64b_bus_word()
self.upper_ctl = (xgmii_64b[0] >> 4) & 0xF
self.upper_data = (xgmii_64b[1] >> 32) & 0xFFFFFFFF
return (
xgmii_64b[0] & 0xF,
xgmii_64b[1] & 0xFFFFFFFF,
)
else:
raise ValueError("Unknown dw {}!".format(dw))
def done(self):
return self.next_row is None
def inject(self, xgmii_interface, stop_cond=None):
proper_stop_cond = True
if stop_cond is None:
proper_stop_cond = False
stop_cond = lambda: False
while not self.done():
if stop_cond():
return
(ctl, data) = self.get_bus_word(len(xgmii_interface.rx_data))
yield xgmii_interface.rx_ctl.eq(ctl)
yield xgmii_interface.rx_data.eq(data)
yield
while self.done() and proper_stop_cond and not stop_cond():
yield xgmii_interface.rx_ctl.eq(0xFF)
yield xgmii_interface.rx_data.eq(0x0707070707070707)
yield
class TestXGMIIPHY(unittest.TestCase):
def test_xgmii_rx(self):
# Read XGMII data from the CSV file
csv_file = Path(__file__).parent / "assets" / "xgmii_bus_capture.csv"
xgmii_injector = XGMII64bCSVReader(
csv_file.resolve(),
complete_trailing_transaction=True
)
# Collect the XGMII transactions from the reader with a minimum
# inter-frame gap of 5 (accounted for potential IFG shrinkage).
xgmii_collector = XGMIICollector(
min_interframegap=5,
tolerate_dic=False,
debug_print=True,
)
# XGMII interface
xgmii_interface = Record([
("rx_ctl", 8),
("rx_data", 64),
("tx_ctl", 8),
("tx_data", 64),
])
# We simply test the receiver component (XGMII -> stream) here.
dut = LiteEthPHYXGMIIRX(
xgmii_interface,
64,
)
recvd_packets = []
run_simulation(
dut,
[
xgmii_injector.inject(
xgmii_interface,
),
xgmii_collector.collect(
xgmii_interface,
tap_signals="rx",
stop_cond=lambda: xgmii_injector.done() \
and xgmii_collector.current_packet is None,
),
stream_collector(
dut.source,
dest=recvd_packets,
stop_cond=xgmii_injector.done,
seed=42,
debug_print=True,
# The XGMII PHY RX part deliberately does not support a
# deasserted ready signal. The sink is assumed to be always
# ready.
ready_rand=0,
),
],
)
self.assertTrue(
len(recvd_packets) == len(xgmii_collector.packets),
"Different number of received and sent packets: {} vs. {}!"
.format(len(recvd_packets), len(xgmii_collector.packets))
)
for p, (recvd, sent) in enumerate(
zip(recvd_packets, xgmii_collector.packets)):
self.assertTrue(
len(recvd.data) == len(sent),
("Packet sent and received with different length: {} vs. {} "
+ "at packet {}!"
).format(len(recvd.data), len(sent), p)
)
for i, (a, b) in enumerate(zip(recvd.data, sent)):
self.assertTrue(
a == b,
("Byte sent and received differ: {} vs. {} at {} byte of "
+ "packet {}"
).format(a, b, i, p)
)
def test_xgmii_stream_loopback(self):
# Read XGMII data from the CSV file
csv_file = Path(__file__).parent / "assets" / "xgmii_bus_capture.csv"
xgmii_injector = XGMII64bCSVReader(
csv_file.resolve(),
complete_trailing_transaction=True
)
# Collect the XGMII transactions from the CSV reader with a minimum
# inter-frame gap of 5 (accounted for potential IFG shrinkage).
xgmii_rx_collector = XGMIICollector(
min_interframegap=5,
tolerate_dic=False,
debug_print=True
)
# Collect the XGMII transactions from the TX PHY with a minimum
# inter-frame gap of 5. As a dumb loopback (akin to the behavior of a
# repeater) this is the smallest IPG value which may be put on the wire
# again.
xgmii_tx_collector = XGMIICollector(
min_interframegap=12,
tolerate_dic=True,
debug_print=True
)
class DUT(Module):
def __init__(self):
# XGMII signals
self.xgmii_interface = Record([
("rx_ctl", 8),
("rx_data", 64),
("tx_ctl", 8),
("tx_data", 64),
])
# PHY with TX and RX side
self.submodules.ethphy = ClockDomainsRenamer({
"eth_tx": "sys",
"eth_rx": "sys",
})(LiteEthPHYXGMII(
Record([("rx", 1), ("tx", 1)]),
self.xgmii_interface,
model=True,
))
# Insert a synchronous FIFO to allow some variability of the
# inter-frame gap. If it overflows we know that we're not
# processing data at line rate, thus we must make sure that we
# detect such a case.
self.submodules.loopback_fifo = SyncFIFO(
self.ethphy.source.payload.layout,
4,
True,
)
self.comb += [
self.ethphy.source.connect(self.loopback_fifo.sink),
self.loopback_fifo.source.connect(self.ethphy.sink),
]
dut = DUT()
run_simulation(
dut,
[
xgmii_rx_collector.collect(
dut.xgmii_interface,
tap_signals="rx",
stop_cond=lambda: xgmii_injector.done() \
and xgmii_rx_collector.current_packet is None,
),
xgmii_tx_collector.collect(
dut.xgmii_interface,
tap_signals="tx",
stop_cond=lambda: xgmii_injector.done() \
and xgmii_tx_collector.current_packet is None \
and len(xgmii_tx_collector.packets) \
>= len(xgmii_rx_collector.packets),
),
xgmii_injector.inject(
dut.xgmii_interface,
stop_cond=lambda: not xgmii_rx_collector.collecting \
and not xgmii_tx_collector.collecting,
),
],
)
self.assertTrue(
len(xgmii_rx_collector.packets) == len(xgmii_tx_collector.packets),
"Different number of sent and received packets: {} vs. {}!"
.format(len(xgmii_rx_collector.packets),
len(xgmii_tx_collector.packets))
)
for p, (recvd, sent) in enumerate(
zip(xgmii_tx_collector.packets, xgmii_rx_collector.packets)):
self.assertTrue(
len(recvd) == len(sent),
("Packet sent and received with different length: {} vs. {} at "
+ "packet {}!"
).format(len(recvd), len(sent), p)
)
for i, (a, b) in enumerate(zip(recvd, sent)):
self.assertTrue(
a == b,
("Byte sent and received differ: {} vs. {} at {} byte of "
+ "packet {}"
).format(a, b, i, p)
)