Mesh_XY.py revision 11666:10d59d546ea2 
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
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9# redistributions in binary form must reproduce the above copyright
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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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19# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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26# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27#
28# Authors: Brad Beckmann
29#          Tushar Krishna
30
31from m5.params import *
32from m5.objects import *
33
34from BaseTopology import SimpleTopology
35
36# Creates a generic Mesh assuming an equal number of cache
37# and directory controllers.
38# XY routing is enforced (using link weights)
39# to guarantee deadlock freedom.
40
41class Mesh_XY(SimpleTopology):
42    description='Mesh_XY'
43
44    def __init__(self, controllers):
45        self.nodes = controllers
46
47    # Makes a generic mesh
48    # assuming an equal number of cache and directory cntrls
49
50    def makeTopology(self, options, network, IntLink, ExtLink, Router):
51        nodes = self.nodes
52
53        num_routers = options.num_cpus
54        num_rows = options.mesh_rows
55
56        # default values for link latency and router latency.
57        # Can be over-ridden on a per link/router basis
58        link_latency = options.link_latency # used by simple and garnet
59        router_latency = options.router_latency # only used by garnet
60
61
62        # There must be an evenly divisible number of cntrls to routers
63        # Also, obviously the number or rows must be <= the number of routers
64        cntrls_per_router, remainder = divmod(len(nodes), num_routers)
65        assert(num_rows > 0 and num_rows <= num_routers)
66        num_columns = int(num_routers / num_rows)
67        assert(num_columns * num_rows == num_routers)
68
69        # Create the routers in the mesh
70        routers = [Router(router_id=i, latency = router_latency) \
71            for i in range(num_routers)]
72        network.routers = routers
73
74        # link counter to set unique link ids
75        link_count = 0
76
77        # Add all but the remainder nodes to the list of nodes to be uniformly
78        # distributed across the network.
79        network_nodes = []
80        remainder_nodes = []
81        for node_index in xrange(len(nodes)):
82            if node_index < (len(nodes) - remainder):
83                network_nodes.append(nodes[node_index])
84            else:
85                remainder_nodes.append(nodes[node_index])
86
87        # Connect each node to the appropriate router
88        ext_links = []
89        for (i, n) in enumerate(network_nodes):
90            cntrl_level, router_id = divmod(i, num_routers)
91            assert(cntrl_level < cntrls_per_router)
92            ext_links.append(ExtLink(link_id=link_count, ext_node=n,
93                                    int_node=routers[router_id],
94                                    latency = link_latency))
95            link_count += 1
96
97        # Connect the remainding nodes to router 0.  These should only be
98        # DMA nodes.
99        for (i, node) in enumerate(remainder_nodes):
100            assert(node.type == 'DMA_Controller')
101            assert(i < remainder)
102            ext_links.append(ExtLink(link_id=link_count, ext_node=node,
103                                    int_node=routers[0],
104                                    latency = link_latency))
105            link_count += 1
106
107        network.ext_links = ext_links
108
109        # Create the mesh links.
110        int_links = []
111
112        # East output to West input links (weight = 1)
113        for row in xrange(num_rows):
114            for col in xrange(num_columns):
115                if (col + 1 < num_columns):
116                    east_out = col + (row * num_columns)
117                    west_in = (col + 1) + (row * num_columns)
118                    int_links.append(IntLink(link_id=link_count,
119                                             src_node=routers[east_out],
120                                             dst_node=routers[west_in],
121                                             src_outport="East",
122                                             dst_inport="West",
123                                             latency = link_latency,
124                                             weight=1))
125                    link_count += 1
126
127        # West output to East input links (weight = 1)
128        for row in xrange(num_rows):
129            for col in xrange(num_columns):
130                if (col + 1 < num_columns):
131                    east_in = col + (row * num_columns)
132                    west_out = (col + 1) + (row * num_columns)
133                    int_links.append(IntLink(link_id=link_count,
134                                             src_node=routers[west_out],
135                                             dst_node=routers[east_in],
136                                             src_outport="West",
137                                             dst_inport="East",
138                                             latency = link_latency,
139                                             weight=1))
140                    link_count += 1
141
142        # North output to South input links (weight = 2)
143        for col in xrange(num_columns):
144            for row in xrange(num_rows):
145                if (row + 1 < num_rows):
146                    north_out = col + (row * num_columns)
147                    south_in = col + ((row + 1) * num_columns)
148                    int_links.append(IntLink(link_id=link_count,
149                                             src_node=routers[north_out],
150                                             dst_node=routers[south_in],
151                                             src_outport="North",
152                                             dst_inport="South",
153                                             latency = link_latency,
154                                             weight=2))
155                    link_count += 1
156
157        # South output to North input links (weight = 2)
158        for col in xrange(num_columns):
159            for row in xrange(num_rows):
160                if (row + 1 < num_rows):
161                    north_in = col + (row * num_columns)
162                    south_out = col + ((row + 1) * num_columns)
163                    int_links.append(IntLink(link_id=link_count,
164                                             src_node=routers[south_out],
165                                             dst_node=routers[north_in],
166                                             src_outport="South",
167                                             dst_inport="North",
168                                             latency = link_latency,
169                                             weight=2))
170                    link_count += 1
171
172
173        network.int_links = int_links
174