1/*
2 * Copyright (c) 1999-2008 Mark D. Hill and David A. Wood
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
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;

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98
99PerfectSwitch::~PerfectSwitch()
100{
101}
102
103void
104PerfectSwitch::operateVnet(int vnet)
105{
106 // This is for round-robin scheduling
107 int incoming = m_round_robin_start;
108 m_round_robin_start++;
109 if (m_round_robin_start >= m_in.size()) {
110 m_round_robin_start = 0;
111 }
112
113 if(m_pending_message_count[vnet] > 0) {
114 // for all input ports, use round robin scheduling
115 for (int counter = 0; counter < m_in.size(); counter++) {
116 // Round robin scheduling
117 incoming++;
118 if (incoming >= m_in.size()) {
119 incoming = 0;
120 }
121
122 // Is there a message waiting?
123 if (m_in[incoming].size() <= vnet) {
124 continue;
125 }
126
127 MessageBuffer *buffer = m_in[incoming][vnet];
128 if (buffer == nullptr) {
129 continue;
130 }
131
132 operateMessageBuffer(buffer, incoming, vnet);
133 }
134 }
135}
136
137void
138PerfectSwitch::operateMessageBuffer(MessageBuffer *buffer, int incoming,
139 int vnet)
140{
141 MsgPtr msg_ptr;
142 Message *net_msg_ptr = NULL;
143
144 // temporary vectors to store the routing results
145 vector<LinkID> output_links;
146 vector<NetDest> output_link_destinations;
147
148 while (buffer->isReady()) {
149 DPRINTF(RubyNetwork, "incoming: %d\n", incoming);
150
151 // Peek at message
152 msg_ptr = buffer->peekMsgPtr();
153 net_msg_ptr = msg_ptr.get();
154 DPRINTF(RubyNetwork, "Message: %s\n", (*net_msg_ptr));
155
156 output_links.clear();
157 output_link_destinations.clear();
158 NetDest msg_dsts = net_msg_ptr->getDestination();
159
160 // Unfortunately, the token-protocol sends some
161 // zero-destination messages, so this assert isn't valid
162 // assert(msg_dsts.count() > 0);
163
164 assert(m_link_order.size() == m_routing_table.size());
165 assert(m_link_order.size() == m_out.size());
166
167 if (m_network_ptr->getAdaptiveRouting()) {
168 if (m_network_ptr->isVNetOrdered(vnet)) {
169 // Don't adaptively route
170 for (int out = 0; out < m_out.size(); out++) {
171 m_link_order[out].m_link = out;
172 m_link_order[out].m_value = 0;
173 }
174 } else {
175 // Find how clogged each link is
176 for (int out = 0; out < m_out.size(); out++) {
177 int out_queue_length = 0;
178 for (int v = 0; v < m_virtual_networks; v++) {
179 out_queue_length += m_out[out][v]->getSize();
180 }
181 int value =
182 (out_queue_length << 8) |
183 random_mt.random(0, 0xff);
184 m_link_order[out].m_link = out;
185 m_link_order[out].m_value = value;
186 }
187
188 // Look at the most empty link first
189 sort(m_link_order.begin(), m_link_order.end());
190 }
191 }
192
193 for (int i = 0; i < m_routing_table.size(); i++) {
194 // pick the next link to look at
195 int link = m_link_order[i].m_link;
196 NetDest dst = m_routing_table[link];
197 DPRINTF(RubyNetwork, "dst: %s\n", dst);
198
199 if (!msg_dsts.intersectionIsNotEmpty(dst))
200 continue;
201
202 // Remember what link we're using
203 output_links.push_back(link);
204
205 // Need to remember which destinations need this message in
206 // another vector. This Set is the intersection of the
207 // routing_table entry and the current destination set. The
208 // intersection must not be empty, since we are inside "if"
209 output_link_destinations.push_back(msg_dsts.AND(dst));
210
211 // Next, we update the msg_destination not to include
212 // those nodes that were already handled by this link
213 msg_dsts.removeNetDest(dst);
214 }
215
216 assert(msg_dsts.count() == 0);
217
218 // Check for resources - for all outgoing queues
219 bool enough = true;
220 for (int i = 0; i < output_links.size(); i++) {
221 int outgoing = output_links[i];
222
223 if (!m_out[outgoing][vnet]->areNSlotsAvailable(1))
224 enough = false;
225
226 DPRINTF(RubyNetwork, "Checking if node is blocked ..."
227 "outgoing: %d, vnet: %d, enough: %d\n",
228 outgoing, vnet, enough);
229 }
230
231 // There were not enough resources
232 if (!enough) {
233 scheduleEvent(Cycles(1));
234 DPRINTF(RubyNetwork, "Can't deliver message since a node "
235 "is blocked\n");
236 DPRINTF(RubyNetwork, "Message: %s\n", (*net_msg_ptr));
237 break; // go to next incoming port
238 }
239
240 MsgPtr unmodified_msg_ptr;
241
242 if (output_links.size() > 1) {
243 // If we are sending this message down more than one link
244 // (size>1), we need to make a copy of the message so each
245 // branch can have a different internal destination we need
246 // to create an unmodified MsgPtr because the MessageBuffer
247 // enqueue func will modify the message
248
249 // This magic line creates a private copy of the message
250 unmodified_msg_ptr = msg_ptr->clone();
251 }
252
253 // Dequeue msg
254 buffer->dequeue();
255 m_pending_message_count[vnet]--;
256
257 // Enqueue it - for all outgoing queues
258 for (int i=0; i<output_links.size(); i++) {
259 int outgoing = output_links[i];
260
261 if (i > 0) {
262 // create a private copy of the unmodified message
263 msg_ptr = unmodified_msg_ptr->clone();
264 }
265
266 // Change the internal destination set of the message so it
267 // knows which destinations this link is responsible for.
268 net_msg_ptr = msg_ptr.get();
269 net_msg_ptr->getDestination() = output_link_destinations[i];
270
271 // Enqeue msg
272 DPRINTF(RubyNetwork, "Enqueuing net msg from "
273 "inport[%d][%d] to outport [%d][%d].\n",
274 incoming, vnet, outgoing, vnet);
275
276 m_out[outgoing][vnet]->enqueue(msg_ptr);
277 }
278 }
279}
280
281void
282PerfectSwitch::wakeup()
283{
284 // Give the highest numbered link priority most of the time

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