# Copyright (c) 2021 ARM Limited
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# Copyright (c) 2011 Advanced Micro Devices, Inc.
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from m5.params import *
from m5.proxy import *
from m5.util import fatal
from m5.SimObject import SimObject
from m5.objects.BasicLink import BasicIntLink, BasicExtLink
from m5.objects.MessageBuffer import MessageBuffer


class SimpleExtLink(BasicExtLink):
    type = "SimpleExtLink"
    cxx_header = "mem/ruby/network/simple/SimpleLink.hh"
    cxx_class = "gem5::ruby::SimpleExtLink"


class SimpleIntLink(BasicIntLink):
    type = "SimpleIntLink"
    cxx_header = "mem/ruby/network/simple/SimpleLink.hh"
    cxx_class = "gem5::ruby::SimpleIntLink"

    # Buffers for this internal link.
    # One buffer is allocated per vnet when setup_buffers is called.
    # These are created by setup_buffers and the user should not
    # set these manually.
    buffers = VectorParam.MessageBuffer([], "Buffers for int_links")

    def setup_buffers(self, network):
        if len(self.buffers) > 0:
            fatal(
                "User should not manually set links' \
                   in_buffers or out_buffers"
            )

        # The network needs number_of_virtual_networks buffers per
        # in and out port
        buffers = []
        for i in range(int(network.number_of_virtual_networks)):
            buffers.append(MessageBuffer(ordered=True))

        # If physical_vnets_channels is set we adjust the buffer sizes and
        # the max_dequeue_rate in order to achieve the expected thoughput
        # assuming a fully pipelined link, i.e., throughput of 1 msg per cycle
        # per channel (assuming the channels width matches the protocol
        # logical message size, otherwise maximum thoughput may be smaller).
        # In MessageBuffer, an entry occupied by a dequeued message at cycle
        # X will available for enqueuing another message at cycle X+1. So
        # for a 1 cy enqueue latency, 2 entries are needed. For any latency,
        # the size should be at least latency+1.
        if len(network.physical_vnets_channels) != 0:
            assert len(network.physical_vnets_channels) == int(
                network.number_of_virtual_networks
            )
            for i in range(int(network.number_of_virtual_networks)):
                buffers[i].buffer_size = network.physical_vnets_channels[i] * (
                    self.latency + 1
                )
                buffers[i].max_dequeue_rate = network.physical_vnets_channels[
                    i
                ]

        self.buffers = buffers