# Copyright (c) 2021 The Regents of the University of California
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"""
This script is used for running a traffic generator connected to a memory
device. It supports linear and random accesses with a configurable amount
of write traffic.

By default, this scripts runs with one channel (two pseudo channels) of HBM2
and this channel is driven with 32GiB/s of traffic for 1ms.
"""

import argparse

from m5.objects import MemorySize

from gem5.components.boards.test_board import TestBoard
from gem5.components.memory.dram_interfaces.hbm import HBM_2000_4H_1x64
from gem5.components.memory.hbm import HighBandwidthMemory
from gem5.components.processors.linear_generator import LinearGenerator
from gem5.components.processors.random_generator import RandomGenerator
from gem5.simulate.simulator import Simulator


def generator_factory(
    generator_class: str, rd_perc: int, mem_size: MemorySize
):
    rd_perc = int(rd_perc)
    if rd_perc > 100 or rd_perc < 0:
        raise ValueError(
            "Read percentage has to be an integer number between 0 and 100."
        )
    if generator_class == "LinearGenerator":
        return LinearGenerator(
            duration="1ms", rate="32GiB/s", max_addr=mem_size, rd_perc=rd_perc
        )
    elif generator_class == "RandomGenerator":
        return RandomGenerator(
            duration="1ms", rate="32GiB/s", max_addr=mem_size, rd_perc=rd_perc
        )
    else:
        raise ValueError(f"Unknown generator class {generator_class}")


parser = argparse.ArgumentParser(
    description="A traffic generator that can be used to test a gem5 "
    "memory component."
)

parser.add_argument(
    "generator_class",
    type=str,
    help="The class of generator to use.",
    choices=[
        "LinearGenerator",
        "RandomGenerator",
    ],
)

parser.add_argument(
    "read_percentage",
    type=int,
    help="Percentage of read requests in the generated traffic.",
)

args = parser.parse_args()

# Single pair of HBM2 pseudo channels. This can be replaced with any
# single ported memory device
memory = HighBandwidthMemory(HBM_2000_4H_1x64, 1, 128)

generator = generator_factory(
    args.generator_class, args.read_percentage, memory.get_size()
)

# We use the Test Board. This is a special board to run traffic generation
# tasks. Can replace the cache_hierarchy with any hierarchy to simulate the
# cache as well as the memory
board = TestBoard(
    clk_freq="1GHz",  # Ignored for these generators
    generator=generator,  # We pass the traffic generator as the processor.
    memory=memory,
    # With no cache hierarchy the test board will directly connect the
    # generator to the memory
    cache_hierarchy=None,
)

simulator = Simulator(board=board)
simulator.run()