# Copyright (c) 2010 Advanced Micro Devices, Inc.
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from m5.params import *
from m5.objects import *

from topologies.BaseTopology import SimpleTopology


class Crossbar(SimpleTopology):
    description = "Crossbar"

    def makeTopology(self, options, network, IntLink, ExtLink, Router):

        # default values for link latency and router latency.
        # Can be over-ridden on a per link/router basis
        link_latency = options.link_latency  # used by simple and garnet
        router_latency = options.router_latency  # only used by garnet

        # Create an individual router for each controller plus one more for
        # the centralized crossbar.  The large numbers of routers are needed
        # because external links do not model outgoing bandwidth in the
        # simple network, but internal links do.
        # For garnet, one router suffices, use CrossbarGarnet.py

        routers = [Router(router_id=i) for i in range(len(self.nodes) + 1)]
        xbar = routers[
            len(self.nodes)
        ]  # the crossbar router is the last router created
        network.routers = routers

        ext_links = [
            ExtLink(
                link_id=i,
                ext_node=n,
                int_node=routers[i],
                latency=link_latency,
            )
            for (i, n) in enumerate(self.nodes)
        ]
        network.ext_links = ext_links

        link_count = len(self.nodes)

        int_links = []
        for i in range(len(self.nodes)):
            int_links.append(
                IntLink(
                    link_id=(link_count + i),
                    src_node=routers[i],
                    dst_node=xbar,
                    latency=link_latency,
                )
            )

        link_count += len(self.nodes)

        for i in range(len(self.nodes)):
            int_links.append(
                IntLink(
                    link_id=(link_count + i),
                    src_node=xbar,
                    dst_node=routers[i],
                    latency=link_latency,
                )
            )

        network.int_links = int_links