# Copyright (c) 2016 Georgia Institute of Technology
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import math
import m5
from m5.objects import *
from m5.defines import buildEnv
from m5.util import addToPath, fatal, warn

def define_options(parser):
    # By default, ruby uses the simple timing cpu
    parser.set_defaults(cpu_type="TimingSimpleCPU")

    parser.add_argument(
        "--topology", type=str, default="Crossbar",
        help="check configs/topologies for complete set")
    parser.add_argument(
        "--mesh-rows", type=int, default=0,
        help="the number of rows in the mesh topology")
    parser.add_argument(
        "--network", default="simple",
        choices=['simple', 'garnet'],
        help="""'simple'|'garnet' (garnet2.0 will be deprecated.)""")
    parser.add_argument(
        "--router-latency", action="store", type=int,
        default=1,
        help="""number of pipeline stages in the garnet router.
            Has to be >= 1.
            Can be over-ridden on a per router basis
            in the topology file.""")
    parser.add_argument(
        "--link-latency", action="store", type=int, default=1,
        help="""latency of each link the simple/garnet networks.
        Has to be >= 1. Can be over-ridden on a per link basis
        in the topology file.""")
    parser.add_argument(
        "--link-width-bits", action="store", type=int,
        default=128,
        help="width in bits for all links inside garnet.")
    parser.add_argument(
        "--vcs-per-vnet", action="store", type=int, default=4,
        help="""number of virtual channels per virtual network
            inside garnet network.""")
    parser.add_argument(
        "--routing-algorithm", action="store", type=int,
        default=0,
        help="""routing algorithm in network.
            0: weight-based table
            1: XY (for Mesh. see garnet/RoutingUnit.cc)
            2: Custom (see garnet/RoutingUnit.cc""")
    parser.add_argument(
        "--network-fault-model", action="store_true",
        default=False,
        help="""enable network fault model:
            see src/mem/ruby/network/fault_model/""")
    parser.add_argument(
        "--garnet-deadlock-threshold", action="store",
        type=int, default=50000,
        help="network-level deadlock threshold.")

def create_network(options, ruby):

    # Allow legacy users to use garnet through garnet2.0 option
    # until next gem5 release.
    if options.network == "garnet2.0":
        warn("Usage of option 'garnet2.0' will be depracated. " \
            "Please use 'garnet' for using the latest garnet " \
            "version. Current version: 3.0")
        options.network = "garnet"

    # Set the network classes based on the command line options
    if options.network == "garnet":
        NetworkClass = GarnetNetwork
        IntLinkClass = GarnetIntLink
        ExtLinkClass = GarnetExtLink
        RouterClass = GarnetRouter
        InterfaceClass = GarnetNetworkInterface

    else:
        NetworkClass = SimpleNetwork
        IntLinkClass = SimpleIntLink
        ExtLinkClass = SimpleExtLink
        RouterClass = Switch
        InterfaceClass = None

    # Instantiate the network object
    # so that the controllers can connect to it.
    network = NetworkClass(ruby_system = ruby, topology = options.topology,
            routers = [], ext_links = [], int_links = [], netifs = [])

    return (network, IntLinkClass, ExtLinkClass, RouterClass, InterfaceClass)

def init_network(options, network, InterfaceClass):

    if options.network == "garnet":
        network.num_rows = options.mesh_rows
        network.vcs_per_vnet = options.vcs_per_vnet
        network.ni_flit_size = options.link_width_bits / 8
        network.routing_algorithm = options.routing_algorithm
        network.garnet_deadlock_threshold = options.garnet_deadlock_threshold

        # Create Bridges and connect them to the corresponding links
        for intLink in network.int_links:
            intLink.src_net_bridge = NetworkBridge(
                                     link = intLink.network_link,
                                     vtype = 'OBJECT_LINK',
                                     width = intLink.src_node.width)
            intLink.src_cred_bridge = NetworkBridge(
                                    link = intLink.credit_link,
                                    vtype = 'LINK_OBJECT',
                                    width = intLink.src_node.width)
            intLink.dst_net_bridge = NetworkBridge(
                                   link = intLink.network_link,
                                   vtype = 'LINK_OBJECT',
                                     width = intLink.dst_node.width)
            intLink.dst_cred_bridge = NetworkBridge(
                                    link = intLink.credit_link,
                                    vtype = 'OBJECT_LINK',
                                    width = intLink.dst_node.width)

        for extLink in network.ext_links:
            ext_net_bridges = []
            ext_net_bridges.append(NetworkBridge(link =
                                 extLink.network_links[0],
                                 vtype = 'OBJECT_LINK',
                                 width = extLink.width))
            ext_net_bridges.append(NetworkBridge(link =
                                 extLink.network_links[1],
                                 vtype = 'LINK_OBJECT',
                                 width = extLink.width))
            extLink.ext_net_bridge = ext_net_bridges

            ext_credit_bridges = []
            ext_credit_bridges.append(NetworkBridge(link =
                                    extLink.credit_links[0],
                                    vtype = 'LINK_OBJECT',
                                    width = extLink.width))
            ext_credit_bridges.append(NetworkBridge(link =
                                    extLink.credit_links[1],
                                    vtype = 'OBJECT_LINK',
                                    width = extLink.width))
            extLink.ext_cred_bridge = ext_credit_bridges

            int_net_bridges = []
            int_net_bridges.append(NetworkBridge(link =
                                 extLink.network_links[0],
                                 vtype = 'LINK_OBJECT',
                                 width = extLink.int_node.width))
            int_net_bridges.append(NetworkBridge(link =
                                 extLink.network_links[1],
                                 vtype = 'OBJECT_LINK',
                                 width = extLink.int_node.width))
            extLink.int_net_bridge = int_net_bridges

            int_cred_bridges = []
            int_cred_bridges.append(NetworkBridge(link =
                                  extLink.credit_links[0],
                                  vtype = 'OBJECT_LINK',
                                  width = extLink.int_node.width))
            int_cred_bridges.append(NetworkBridge(link =
                                  extLink.credit_links[1],
                                  vtype = 'LINK_OBJECT',
                                  width = extLink.int_node.width))
            extLink.int_cred_bridge = int_cred_bridges

    if options.network == "simple":
        network.setup_buffers()

    if InterfaceClass != None:
        netifs = [InterfaceClass(id=i) \
                  for (i,n) in enumerate(network.ext_links)]
        network.netifs = netifs

    if options.network_fault_model:
        assert(options.network == "garnet")
        network.enable_fault_model = True
        network.fault_model = FaultModel()
