Mesh_XY.py revision 13774 
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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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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25# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27#
28# Authors: Brad Beckmann
29#          Tushar Krishna
30
31from __future__ import print_function
32from __future__ import absolute_import
33
34from m5.params import *
35from m5.objects import *
36
37from .BaseTopology import SimpleTopology
38
39# Creates a generic Mesh assuming an equal number of cache
40# and directory controllers.
41# XY routing is enforced (using link weights)
42# to guarantee deadlock freedom.
43
44class Mesh_XY(SimpleTopology):
45    description='Mesh_XY'
46
47    def __init__(self, controllers):
48        self.nodes = controllers
49
50    # Makes a generic mesh
51    # assuming an equal number of cache and directory cntrls
52
53    def makeTopology(self, options, network, IntLink, ExtLink, Router):
54        nodes = self.nodes
55
56        num_routers = options.num_cpus
57        num_rows = options.mesh_rows
58
59        # default values for link latency and router latency.
60        # Can be over-ridden on a per link/router basis
61        link_latency = options.link_latency # used by simple and garnet
62        router_latency = options.router_latency # only used by garnet
63
64
65        # There must be an evenly divisible number of cntrls to routers
66        # Also, obviously the number or rows must be <= the number of routers
67        cntrls_per_router, remainder = divmod(len(nodes), num_routers)
68        assert(num_rows > 0 and num_rows <= num_routers)
69        num_columns = int(num_routers / num_rows)
70        assert(num_columns * num_rows == num_routers)
71
72        # Create the routers in the mesh
73        routers = [Router(router_id=i, latency = router_latency) \
74            for i in range(num_routers)]
75        network.routers = routers
76
77        # link counter to set unique link ids
78        link_count = 0
79
80        # Add all but the remainder nodes to the list of nodes to be uniformly
81        # distributed across the network.
82        network_nodes = []
83        remainder_nodes = []
84        for node_index in range(len(nodes)):
85            if node_index < (len(nodes) - remainder):
86                network_nodes.append(nodes[node_index])
87            else:
88                remainder_nodes.append(nodes[node_index])
89
90        # Connect each node to the appropriate router
91        ext_links = []
92        for (i, n) in enumerate(network_nodes):
93            cntrl_level, router_id = divmod(i, num_routers)
94            assert(cntrl_level < cntrls_per_router)
95            ext_links.append(ExtLink(link_id=link_count, ext_node=n,
96                                    int_node=routers[router_id],
97                                    latency = link_latency))
98            link_count += 1
99
100        # Connect the remainding nodes to router 0.  These should only be
101        # DMA nodes.
102        for (i, node) in enumerate(remainder_nodes):
103            assert(node.type == 'DMA_Controller')
104            assert(i < remainder)
105            ext_links.append(ExtLink(link_id=link_count, ext_node=node,
106                                    int_node=routers[0],
107                                    latency = link_latency))
108            link_count += 1
109
110        network.ext_links = ext_links
111
112        # Create the mesh links.
113        int_links = []
114
115        # East output to West input links (weight = 1)
116        for row in range(num_rows):
117            for col in range(num_columns):
118                if (col + 1 < num_columns):
119                    east_out = col + (row * num_columns)
120                    west_in = (col + 1) + (row * num_columns)
121                    int_links.append(IntLink(link_id=link_count,
122                                             src_node=routers[east_out],
123                                             dst_node=routers[west_in],
124                                             src_outport="East",
125                                             dst_inport="West",
126                                             latency = link_latency,
127                                             weight=1))
128                    link_count += 1
129
130        # West output to East input links (weight = 1)
131        for row in range(num_rows):
132            for col in range(num_columns):
133                if (col + 1 < num_columns):
134                    east_in = col + (row * num_columns)
135                    west_out = (col + 1) + (row * num_columns)
136                    int_links.append(IntLink(link_id=link_count,
137                                             src_node=routers[west_out],
138                                             dst_node=routers[east_in],
139                                             src_outport="West",
140                                             dst_inport="East",
141                                             latency = link_latency,
142                                             weight=1))
143                    link_count += 1
144
145        # North output to South input links (weight = 2)
146        for col in range(num_columns):
147            for row in range(num_rows):
148                if (row + 1 < num_rows):
149                    north_out = col + (row * num_columns)
150                    south_in = col + ((row + 1) * num_columns)
151                    int_links.append(IntLink(link_id=link_count,
152                                             src_node=routers[north_out],
153                                             dst_node=routers[south_in],
154                                             src_outport="North",
155                                             dst_inport="South",
156                                             latency = link_latency,
157                                             weight=2))
158                    link_count += 1
159
160        # South output to North input links (weight = 2)
161        for col in range(num_columns):
162            for row in range(num_rows):
163                if (row + 1 < num_rows):
164                    north_in = col + (row * num_columns)
165                    south_out = col + ((row + 1) * num_columns)
166                    int_links.append(IntLink(link_id=link_count,
167                                             src_node=routers[south_out],
168                                             dst_node=routers[north_in],
169                                             src_outport="South",
170                                             dst_inport="North",
171                                             latency = link_latency,
172                                             weight=2))
173                    link_count += 1
174
175
176        network.int_links = int_links
177