configs/topologies/Mesh_westfirst.py

   1 # Copyright (c) 2010 Advanced Micro Devices, Inc.
   2 #               2016 Georgia Institute of Technology
   3 # All rights reserved.
   4 #
   5 # Redistribution and use in source and binary forms, with or without
   6 # modification, are permitted provided that the following conditions are
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   9 # redistributions in binary form must reproduce the above copyright
  10 # notice, this list of conditions and the following disclaimer in the
  11 # documentation and/or other materials provided with the distribution;
  12 # neither the name of the copyright holders nor the names of its
  13 # contributors may be used to endorse or promote products derived from
  14 # this software without specific prior written permission.
  15 #
  16 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  17 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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  20 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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  26 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27
  28 from __future__ import print_function
  29 from __future__ import absolute_import
  30
  31 from m5.params import *
  32 from m5.objects import *
  33
  34 from topologies.BaseTopology import SimpleTopology
  35
  36 # Creates a generic Mesh assuming an equal number of cache
  37 # and directory controllers.
  38 # West-first routing is enforced (using link weights)
  39 # to guarantee deadlock freedom.
  40 # The network randomly chooses between links with the same
  41 # weight for messages within unordered virtual networks.
  42 # Within ordered virtual networks, a fixed link direction
  43 # is always chosen based on which appears first inside the
  44 # routing table.
  45
  46 class Mesh_westfirst(SimpleTopology):
  47     description='Mesh_westfirst'
  48
  49     def __init__(self, controllers):
  50         self.nodes = controllers
  51
  52     # Makes a generic mesh
  53     # assuming an equal number of cache and directory cntrls
  54
  55     def makeTopology(self, options, network, IntLink, ExtLink, Router):
  56         nodes = self.nodes
  57
  58         num_routers = options.num_cpus
  59         num_rows = options.mesh_rows
  60
  61         # default values for link latency and router latency.
  62         # Can be over-ridden on a per link/router basis
  63         link_latency = options.link_latency # used by simple and garnet
  64         router_latency = options.router_latency # only used by garnet
  65
  66         # There must be an evenly divisible number of cntrls to routers
  67         # Also, obviously the number or rows must be <= the number of routers
  68         cntrls_per_router, remainder = divmod(len(nodes), num_routers)
  69         assert(num_rows > 0 and num_rows <= num_routers)
  70         num_columns = int(num_routers / num_rows)
  71         assert(num_columns * num_rows == num_routers)
  72
  73         # Create the routers in the mesh
  74         routers = [Router(router_id=i, latency=router_latency) \
  75             for i in range(num_routers)]
  76         network.routers = routers
  77
  78         # link counter to set unique link ids
  79         link_count = 0
  80
  81         # Add all but the remainder nodes to the list of nodes to be uniformly
  82         # distributed across the network.
  83         network_nodes = []
  84         remainder_nodes = []
  85         for node_index in range(len(nodes)):
  86             if node_index < (len(nodes) - remainder):
  87                 network_nodes.append(nodes[node_index])
  88             else:
  89                 remainder_nodes.append(nodes[node_index])
  90
  91         # Connect each node to the appropriate router
  92         ext_links = []
  93         for (i, n) in enumerate(network_nodes):
  94             cntrl_level, router_id = divmod(i, num_routers)
  95             assert(cntrl_level < cntrls_per_router)
  96             ext_links.append(ExtLink(link_id=link_count, ext_node=n,
  97                                     int_node=routers[router_id],
  98                                     latency = link_latency))
  99             link_count += 1
 100
 101         # Connect the remainding nodes to router 0.  These should only be
 102         # DMA nodes.
 103         for (i, node) in enumerate(remainder_nodes):
 104             assert(node.type == 'DMA_Controller')
 105             assert(i < remainder)
 106             ext_links.append(ExtLink(link_id=link_count, ext_node=node,
 107                                     int_node=routers[0],
 108                                     latency = link_latency))
 109             link_count += 1
 110
 111         network.ext_links = ext_links
 112
 113         # Create the mesh links.
 114         int_links = []
 115
 116         # East output to West input links (weight = 2)
 117         for row in range(num_rows):
 118             for col in range(num_columns):
 119                 if (col + 1 < num_columns):
 120                     east_out = col + (row * num_columns)
 121                     west_in = (col + 1) + (row * num_columns)
 122                     int_links.append(IntLink(link_id=link_count,
 123                                              src_node=routers[east_out],
 124                                              dst_node=routers[west_in],
 125                                              latency = link_latency,
 126                                              weight=2))
 127                     link_count += 1
 128
 129         # West output to East input links (weight = 1)
 130         for row in range(num_rows):
 131             for col in range(num_columns):
 132                 if (col + 1 < num_columns):
 133                     east_in = col + (row * num_columns)
 134                     west_out = (col + 1) + (row * num_columns)
 135                     int_links.append(IntLink(link_id=link_count,
 136                                              src_node=routers[west_out],
 137                                              dst_node=routers[east_in],
 138                                              latency = link_latency,
 139                                              weight=1))
 140                     link_count += 1
 141
 142
 143         # North output to South input links (weight = 2)
 144         for col in range(num_columns):
 145             for row in range(num_rows):
 146                 if (row + 1 < num_rows):
 147                     north_out = col + (row * num_columns)
 148                     south_in = col + ((row + 1) * num_columns)
 149                     int_links.append(IntLink(link_id=link_count,
 150                                              src_node=routers[north_out],
 151                                              dst_node=routers[south_in],
 152                                              latency = link_latency,
 153                                              weight=2))
 154                     link_count += 1
 155
 156         # South output to North input links (weight = 2)
 157         for col in range(num_columns):
 158             for row in range(num_rows):
 159                 if (row + 1 < num_rows):
 160                     north_in = col + (row * num_columns)
 161                     south_out = col + ((row + 1) * num_columns)
 162                     int_links.append(IntLink(link_id=link_count,
 163                                              src_node=routers[south_out],
 164                                              dst_node=routers[north_in],
 165                                              latency = link_latency,
 166                                              weight=2))
 167                     link_count += 1
 168
 169
 170         network.int_links = int_links