# Copyright (c) 2021 Advanced Micro Devices, Inc.
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
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# 1. Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
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# 2. Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions and the following disclaimer in the documentation
# and/or other materials provided with the distribution.
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# 3. Neither the name of the copyright holder nor the names of its
# contributors may be used to endorse or promote products derived from this
# software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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# POSSIBILITY OF SUCH DAMAGE.

# System includes
import argparse
import math

# gem5 related
import m5
from m5.objects import *
from m5.util import addToPath

# gem5 options and objects
addToPath("../../")
from ruby import Ruby
from common import Simulation
from common import ObjectList
from common import Options
from common import GPUTLBOptions
from common import GPUTLBConfig
from amd import AmdGPUOptions

# GPU FS related
from system.system import makeGpuFSSystem


def addRunFSOptions(parser):
    parser.add_argument(
        "--script",
        default=None,
        help="Script to execute in the simulated system",
    )
    parser.add_argument(
        "--host-parallel",
        default=False,
        action="store_true",
        help="Run multiple host threads in KVM mode",
    )
    parser.add_argument(
        "--restore-dir",
        type=str,
        default=None,
        help="Directory to restore checkpoints from",
    )
    parser.add_argument(
        "--disk-image",
        default="",
        help="The boot disk image to mount (/dev/sda)",
    )
    parser.add_argument(
        "--second-disk",
        default=None,
        help="The second disk image to mount (/dev/sdb)",
    )
    parser.add_argument("--kernel", default=None, help="Linux kernel to boot")
    parser.add_argument("--gpu-rom", default=None, help="GPU BIOS to load")
    parser.add_argument(
        "--gpu-mmio-trace", default=None, help="GPU MMIO trace to load"
    )
    parser.add_argument(
        "--checkpoint-before-mmios",
        default=False,
        action="store_true",
        help="Take a checkpoint before driver sends MMIOs. "
        "This is used to switch out of KVM mode and into "
        "timing mode required to read the VGA ROM on boot.",
    )
    parser.add_argument(
        "--cpu-topology",
        type=str,
        default="Crossbar",
        help="Network topology to use for CPU side. "
        "Check configs/topologies for complete set",
    )
    parser.add_argument(
        "--gpu-topology",
        type=str,
        default="Crossbar",
        help="Network topology to use for GPU side. "
        "Check configs/topologies for complete set",
    )
    parser.add_argument(
        "--dgpu-mem-size",
        action="store",
        type=str,
        default="16GB",
        help="Specify the dGPU physical memory" "  size",
    )
    parser.add_argument(
        "--dgpu-num-dirs",
        type=int,
        default=1,
        help="Set " "the number of dGPU directories (memory controllers",
    )
    parser.add_argument(
        "--dgpu-mem-type",
        default="HBM_1000_4H_1x128",
        choices=ObjectList.mem_list.get_names(),
        help="type of memory to use",
    )


def runGpuFSSystem(args):
    """
    This function can be called by higher level scripts designed to simulate
    specific devices. As a result the scripts typically hard code some args
    that should not be changed by the user.
    """

    # GPUFS is primarily designed to use the X86 KVM CPU. This model needs to
    # use multiple event queues when more than one CPU is simulated. Force it
    # on if that is the case.
    args.host_parallel = True if args.num_cpus > 1 else False

    # These are used by the protocols. They should not be set by the user.
    n_cu = args.num_compute_units
    args.num_sqc = int(math.ceil(float(n_cu) / args.cu_per_sqc))
    args.num_scalar_cache = int(
        math.ceil(float(n_cu) / args.cu_per_scalar_cache)
    )

    system = makeGpuFSSystem(args)

    root = Root(
        full_system=True,
        system=system,
        time_sync_enable=True,
        time_sync_period="1000us",
    )

    if args.host_parallel:
        root.sim_quantum = int(1e8)

    if args.script is not None:
        system.readfile = args.script

    if args.restore_dir is None:
        m5.instantiate()
    else:
        m5.instantiate(args.restore_dir)

    print("Running the simulation")
    sim_ticks = args.abs_max_tick

    exit_event = m5.simulate(sim_ticks)

    # Keep executing while there is something to do
    while True:
        if (
            exit_event.getCause() == "m5_exit instruction encountered"
            or exit_event.getCause() == "user interrupt received"
            or exit_event.getCause() == "simulate() limit reached"
        ):
            break
        elif "checkpoint" in exit_event.getCause():
            assert args.checkpoint_dir is not None
            m5.checkpoint(args.checkpoint_dir)
            break
        else:
            print(
                "Unknown exit event: %s. Continuing..." % exit_event.getCause()
            )

    print(
        "Exiting @ tick %i because %s" % (m5.curTick(), exit_event.getCause())
    )


if __name__ == "__m5_main__":
    # Add gpufs, common, ruby, amdgpu, and gpu tlb args
    parser = argparse.ArgumentParser()
    addRunFSOptions(parser)
    Options.addCommonOptions(parser)
    Ruby.define_options(parser)
    AmdGPUOptions.addAmdGPUOptions(parser)
    GPUTLBOptions.tlb_options(parser)

    args = parser.parse_args()

    runGpuFSSystem(args)