litex/test/test_stream.py

336 lines
12 KiB
Python

# Copyright (c) 2020 Florent Kermarrec <florent@enjoy-digital.fr>
# SPDX-License-Identifier: BSD-2-Clause
import unittest
import random
import itertools
import sys
from migen import *
from litex.soc.interconnect.stream import *
# Function to iterate over chunks of data, from
# https://docs.python.org/3/library/itertools.html#itertools-recipes
def grouper(iterable, n, fillvalue=None):
"Collect data into fixed-length chunks or blocks"
# grouper('ABCDEFG', 3, 'x') --> ABC DEF Gxx"
args = [iter(iterable)] * n
return itertools.zip_longest(*args, fillvalue=fillvalue)
class StreamPacket:
def __init__(self, data, params={}):
# Data must be a list of bytes
assert type(data) == list
for b in data:
assert type(b) == int and b >= 0 and b < 256
# Params must be a dictionary of strings mapping to integers
assert type(params) == dict
for param_key, param_value in params.items():
assert type(param_key) == str
assert type(param_value) == int
self.data = data
self.params = params
def compare(self, other, quiet=True, output_target=sys.stdout):
if len(self.data) != len(other.data):
if not quiet:
print("Length mismatch in number of received bytes of packet:" \
" {} {}".format(len(self.data), len(other.data)),
file=sys.stdout)
return False
for nbyte, (byte_a, byte_b) in enumerate(zip(self.data, other.data)):
if byte_a != byte_b:
if not quiet:
print("Mismatch between sent and received bytes {}: " \
"0x{:02x} 0x{:02x}".format(nbyte, byte_a, byte_b),
file=sys.stdout)
return False
if set(self.params.keys()) != set(other.params.keys()):
if not quiet:
print("Sent and received packets have different param fields:" \
" {} {}".format(self.params.keys(), other.params.keys()),
file=sys.stdout)
return False
for param_name, self_param_value in self.params.items():
other_param_value = other.params[param_name]
if self_param_value != other_param_value:
if not quiet:
print("Sent and received packets have different value for" \
" param signal \"{}\": 0x{:x} 0x{:x}".format(
param_name,
self_param_value,
other_param_value),
file=sys.stdout)
return False
return True
def stream_inserter(
sink,
src,
seed=42,
valid_rand=50,
debug_print=False,
broken_8bit_last_be=True):
"""Insert a list of packets of bytes on to the stream interface `sink`. If
`sink` has a `last_be` signal, that is set accordingly.
"""
prng = random.Random(seed)
# Extract the data width from the provided sink Endpoint
dw = len(sink.data)
# Make sure dw is evenly divisible by 8 as the logic below relies on
# that. Also, last_be wouldn't make much sense otherwise.
assert dw % 8 == 0
# If a last_be signal is provided, it must contain one bit per byte of data,
# i.e. be dw // 8 long.
if hasattr(sink, "last_be"):
assert dw // 8 == len(sink.last_be)
# src is a list of lists. Each list represents a packet of bytes. Send each
# packet over the bus.
for pi, packet in enumerate(src):
assert len(packet.data) > 0, "Packets of length 0 are not compatible " \
"with the ready/valid stream interface"
# Each packet is a list. We must send dw // 8 bytes at a time. Use the
# grouper method to get a chunked iterator over the packet bytes and
# shift them to their correct position. Use a random filler byte to
# complete a bus word.
words = []
for chunk in grouper(packet.data, dw // 8, prng.randrange(256)):
word = 0
for i, b in enumerate(chunk):
assert b >= 0 and b < 256
word |= b << (i * 8)
words += [word]
if hasattr(sink, "last_be"):
encoded_last_be = Constant(
1 << ((len(packet.data) - 1) % (dw // 8)),
bits_sign=len(sink.last_be)
)
# In legacy code for 8bit data paths last_be might not be set
# properly: while last_be should always be equal to last for 8bit
# data paths, if new code interacts with old code which is not yet
# last_be aware, it might always be deasserted. If
# broken_8bit_last_be is set and we have an 8bit data path, randomly
# set last_be to either one or zero to check whether the DUT handles
# these cases properly.
if broken_8bit_last_be and dw == 8:
encoded_last_be = Constant(prng.randrange(2), bits_sign=1)
# At the very beginning of the packet transmission, set the param
# signals
for param_signal, param_value in packet.params.items():
yield getattr(sink, param_signal).eq(param_value)
for i, word in enumerate(words):
last = i == len(words) - 1
# Place the word on the bus, if its the last word set last and
# last_be accordingly and finally set sink to valid
yield sink.data.eq(word)
yield sink.last.eq(last)
if hasattr(sink, "last_be"):
if last:
yield sink.last_be.eq(encoded_last_be)
else:
yield sink.last_be.eq(0)
yield sink.valid.eq(1)
yield
# Wait until the sink has become ready for one clock cycle
while not (yield sink.ready):
yield
# Set sink to not valid for a random amount of time
yield sink.valid.eq(0)
while prng.randrange(100) < valid_rand:
yield
# Okay, we've transmitted a packet. We must set sink.valid to false, for
# good measure clear all other signals as well. We don't explicitly
# yield, given a there might be a new packet waiting already.
yield sink.data.eq(0)
yield sink.last.eq(0)
if hasattr(sink, "last_be"):
yield sink.last_be.eq(0)
for param_signal in packet.params.keys():
yield getattr(sink, param_signal).eq(0)
yield sink.valid.eq(0)
if debug_print:
print("Sent packet {}.".format(pi), file=sys.stderr)
# All packets have been transmitted. sink.valid has already been
# deasserted, yield once to properly apply that value.
yield
def stream_collector(
source,
dest=[],
expect_npackets=None,
seed=42,
ready_rand=50,
debug_print=False):
"""Consume some packets of bytes from the stream interface
`source`. If `source` has a `last_be` signal, that is respected
properly.
"""
prng = random.Random(seed)
# Extract the data width from the provided source endpoint
dw = len(source.data)
# Make sure dw is evenly divisible by 8 as the logic below relies on
# that. Also, last_be wouldn't make much sense otherwise.
assert dw % 8 == 0
# If a last_be signal is provided, it must contain one bit per byte of data,
# i.e. be dw // 8 long.
if hasattr(source, "last_be"):
assert dw // 8 == len(source.last_be)
# Extract "param_signals" from the source Endpoint. They are extracted on
# the first valid word of a packet. If dest will be a list of tuples with
# data and param signals if there are any, otherwise just a list of lists.
param_signals = [
signal_name for signal_name, _, _ in source.param.layout
] if hasattr(source, "param") else []
# Loop for collecting individual packets, separated by source.last
while expect_npackets == None or len(dest) < expect_npackets:
# Buffer for the current packet
collected_bytes = []
param_signal_states = {}
# Iterate until "last" has been seen. That concludes the end of a bus
# transaction / packet.
read_last = False
first_word = True
while not read_last:
# We are ready to accept another bus word
yield source.ready.eq(1)
yield
# Wait for data to become valid
while (yield source.valid) == 0:
yield
# Data is now valid, read it byte by byte
data = yield source.data
for byte in range(dw // 8):
if (yield source.last) == 1:
read_last = True
if hasattr(source, "last_be") and \
2**byte > (yield source.last_be):
break
collected_bytes += [((data >> (byte * 8)) & 0xFF)]
# Also, if this is the first loop iteration, latch all param signals
for param_signal in param_signals:
param_signal_states[param_signal] = \
yield getattr(source, param_signal)
# Set source to not valid for a random amount of time
yield source.ready.eq(0)
while prng.randrange(100) < ready_rand:
yield
# This is no longer the first loop iteration
first_word = False
# A full packet has been read. Append it to dest.
dest += [StreamPacket(collected_bytes, param_signal_states)]
if debug_print:
print("Received packet {}.".format(len(dest) - 1), file=sys.stderr)
def generate_test_packets(npackets, seed=42):
# Generate a number of last-terminated bus transaction byte contents (dubbed
# packets)
prng = random.Random(42)
packets = []
for _ in range(npackets):
# With a random number of bytes from [1, 1024)
values = []
for _ in range(prng.randrange(1023) + 1):
# With random values from [0, 256).
values += [prng.randrange(256)]
packets += [StreamPacket(values)]
return packets
def compare_packets(packets_a, packets_b):
if len(packets_a) != len(packets_b):
print("Length mismatch in number of received packets: {} {}"
.format(len(packets_a), len(packets_b)), file=sys.stderr)
return False
for npacket, (packet_a, packet_b) in enumerate(zip(packets_a, packets_b)):
if not packet_a.compare(packet_b):
print("Error in packet", npacket)
packet_a.compare(packet_b, quiet=False)
return False
return True
class TestStream(unittest.TestCase):
def pipe_test(self, dut, seed=42, npackets=64, debug_print=False):
# Get some data to test with
packets = generate_test_packets(npackets, seed=seed)
# Buffer for received packets (filled by collector)
recvd_packets = []
run_simulation(
dut,
[
stream_inserter(
dut.sink,
src=packets,
debug_print=debug_print,
seed=seed,
),
stream_collector(
dut.source,
dest=recvd_packets,
expect_npackets=npackets,
debug_print=debug_print,
seed=seed,
),
],
)
self.assertTrue(compare_packets(packets, recvd_packets))
def test_pipe_valid(self):
# PipeValid either connects the entire payload or not. Thus we don't
# need to test for 8bit support or a missing last_be signal
# specifically. This test does however ensure that last_be will continue
# to be respected in the future.
dut = PipeValid([("data", 32), ("last_be", 4)])
self.pipe_test(dut)
def test_pipe_ready(self):
# PipeReady either connects the entire stream Endpoint or not. Thus we
# don't need to test for 8bit support or a missing last_be signal
# specifically. This test does however ensure that last_be will continue
# to be respected in the future.
dut = PipeReady([("data", 64), ("last_be", 8)])
self.pipe_test(dut)