Mesh_XY.py revision 11663 
1# Copyright (c) 2010 Advanced Micro Devices, Inc.
2#               2016 Georgia Institute of Technology
3# All rights reserved.
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9# redistributions in binary form must reproduce the above copyright
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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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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        # There must be an evenly divisible number of cntrls to routers
57        # Also, obviously the number or rows must be <= the number of routers
58        cntrls_per_router, remainder = divmod(len(nodes), num_routers)
59        assert(num_rows <= num_routers)
60        num_columns = int(num_routers / num_rows)
61        assert(num_columns * num_rows == num_routers)
62
63        # Create the routers in the mesh
64        routers = [Router(router_id=i) for i in range(num_routers)]
65        network.routers = routers
66
67        # link counter to set unique link ids
68        link_count = 0
69
70        # Add all but the remainder nodes to the list of nodes to be uniformly
71        # distributed across the network.
72        network_nodes = []
73        remainder_nodes = []
74        for node_index in xrange(len(nodes)):
75            if node_index < (len(nodes) - remainder):
76                network_nodes.append(nodes[node_index])
77            else:
78                remainder_nodes.append(nodes[node_index])
79
80        # Connect each node to the appropriate router
81        ext_links = []
82        for (i, n) in enumerate(network_nodes):
83            cntrl_level, router_id = divmod(i, num_routers)
84            assert(cntrl_level < cntrls_per_router)
85            ext_links.append(ExtLink(link_id=link_count, ext_node=n,
86                                    int_node=routers[router_id]))
87            link_count += 1
88
89        # Connect the remainding nodes to router 0.  These should only be
90        # DMA nodes.
91        for (i, node) in enumerate(remainder_nodes):
92            assert(node.type == 'DMA_Controller')
93            assert(i < remainder)
94            ext_links.append(ExtLink(link_id=link_count, ext_node=node,
95                                    int_node=routers[0]))
96            link_count += 1
97
98        network.ext_links = ext_links
99
100        # Create the mesh links.
101        int_links = []
102
103        # East output to West input links (weight = 1)
104        for row in xrange(num_rows):
105            for col in xrange(num_columns):
106                if (col + 1 < num_columns):
107                    east_out = col + (row * num_columns)
108                    west_in = (col + 1) + (row * num_columns)
109                    int_links.append(IntLink(link_id=link_count,
110                                             src_node=routers[east_out],
111                                             dst_node=routers[west_in],
112                                             weight=1))
113                    link_count += 1
114
115        # West output to East input links (weight = 1)
116        for row in xrange(num_rows):
117            for col in xrange(num_columns):
118                if (col + 1 < num_columns):
119                    east_in = col + (row * num_columns)
120                    west_out = (col + 1) + (row * num_columns)
121                    int_links.append(IntLink(link_id=link_count,
122                                             src_node=routers[west_out],
123                                             dst_node=routers[east_in],
124                                             weight=1))
125                    link_count += 1
126
127        # North output to South input links (weight = 2)
128        for col in xrange(num_columns):
129            for row in xrange(num_rows):
130                if (row + 1 < num_rows):
131                    north_out = col + (row * num_columns)
132                    south_in = col + ((row + 1) * num_columns)
133                    int_links.append(IntLink(link_id=link_count,
134                                             src_node=routers[north_out],
135                                             dst_node=routers[south_in],
136                                             weight=2))
137                    link_count += 1
138
139        # South output to North input links (weight = 2)
140        for col in xrange(num_columns):
141            for row in xrange(num_rows):
142                if (row + 1 < num_rows):
143                    north_in = col + (row * num_columns)
144                    south_out = col + ((row + 1) * num_columns)
145                    int_links.append(IntLink(link_id=link_count,
146                                             src_node=routers[south_out],
147                                             dst_node=routers[north_in],
148                                             weight=2))
149                    link_count += 1
150
151
152        network.int_links = int_links
153