1/*
2 * Copyright (c) 2008 Princeton University
3 * Copyright (c) 2016 Georgia Institute of Technology
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are
8 * met: redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer;
10 * redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution;
13 * neither the name of the copyright holders nor the names of its
14 * contributors may be used to endorse or promote products derived from
15 * this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
20 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
21 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 *
29 * Authors: Niket Agarwal
30 * Tushar Krishna
31 */
32
33
34#include "mem/ruby/network/garnet2.0/NetworkInterface.hh"
35
36#include <cassert>
37#include <cmath>
38
39#include "base/cast.hh"
40#include "base/stl_helpers.hh"
41#include "debug/RubyNetwork.hh"
42#include "mem/ruby/network/MessageBuffer.hh"
43#include "mem/ruby/network/garnet2.0/Credit.hh"
44#include "mem/ruby/network/garnet2.0/flitBuffer.hh"
45#include "mem/ruby/slicc_interface/Message.hh"
46
47using namespace std;
48using m5::stl_helpers::deletePointers;
49
50NetworkInterface::NetworkInterface(const Params *p)
51 : ClockedObject(p), Consumer(this), m_id(p->id),
52 m_virtual_networks(p->virt_nets), m_vc_per_vnet(p->vcs_per_vnet),
53 m_num_vcs(m_vc_per_vnet * m_virtual_networks)
53 m_num_vcs(m_vc_per_vnet * m_virtual_networks),
54 m_deadlock_threshold(p->garnet_deadlock_threshold),
55 vc_busy_counter(m_virtual_networks, 0)
56{
57 m_router_id = -1;
58 m_vc_round_robin = 0;
59 m_ni_out_vcs.resize(m_num_vcs);
60 m_ni_out_vcs_enqueue_time.resize(m_num_vcs);
61 outCreditQueue = new flitBuffer();
62
63 // instantiating the NI flit buffers
64 for (int i = 0; i < m_num_vcs; i++) {
65 m_ni_out_vcs[i] = new flitBuffer();
66 m_ni_out_vcs_enqueue_time[i] = Cycles(INFINITE_);
67 }
68
69 m_vc_allocator.resize(m_virtual_networks); // 1 allocator per vnet
70 for (int i = 0; i < m_virtual_networks; i++) {
71 m_vc_allocator[i] = 0;
72 }
73}
74
75void
76NetworkInterface::init()
77{
78 for (int i = 0; i < m_num_vcs; i++) {
79 m_out_vc_state.push_back(new OutVcState(i, m_net_ptr));
80 }
81}
82
83NetworkInterface::~NetworkInterface()
84{
85 deletePointers(m_out_vc_state);
86 deletePointers(m_ni_out_vcs);
87 delete outCreditQueue;
88 delete outFlitQueue;
89}
90
91void
92NetworkInterface::addInPort(NetworkLink *in_link,
93 CreditLink *credit_link)
94{
95 inNetLink = in_link;
96 in_link->setLinkConsumer(this);
97 outCreditLink = credit_link;
98 credit_link->setSourceQueue(outCreditQueue);
99}
100
101void
102NetworkInterface::addOutPort(NetworkLink *out_link,
103 CreditLink *credit_link,
104 SwitchID router_id)
105{
106 inCreditLink = credit_link;
107 credit_link->setLinkConsumer(this);
108
109 outNetLink = out_link;
110 outFlitQueue = new flitBuffer();
111 out_link->setSourceQueue(outFlitQueue);
112
113 m_router_id = router_id;
114}
115
116void
117NetworkInterface::addNode(vector<MessageBuffer *>& in,
118 vector<MessageBuffer *>& out)
119{
120 inNode_ptr = in;
121 outNode_ptr = out;
122
123 for (auto& it : in) {
124 if (it != nullptr) {
125 it->setConsumer(this);
126 }
127 }
128}
129
130
131/*
132 * The NI wakeup checks whether there are any ready messages in the protocol
133 * buffer. If yes, it picks that up, flitisizes it into a number of flits and
134 * puts it into an output buffer and schedules the output link. On a wakeup
135 * it also checks whether there are flits in the input link. If yes, it picks
136 * them up and if the flit is a tail, the NI inserts the corresponding message
137 * into the protocol buffer. It also checks for credits being sent by the
138 * downstream router.
139 */
140
141void
142NetworkInterface::wakeup()
143{
144 DPRINTF(RubyNetwork, "Network Interface %d connected to router %d "
145 "woke up at time: %lld\n", m_id, m_router_id, curCycle());
146
147 MsgPtr msg_ptr;
148 Tick curTime = clockEdge();
149
150 // Checking for messages coming from the protocol
151 // can pick up a message/cycle for each virtual net
152 for (int vnet = 0; vnet < inNode_ptr.size(); ++vnet) {
153 MessageBuffer *b = inNode_ptr[vnet];
154 if (b == nullptr) {
155 continue;
156 }
157
158 if (b->isReady(curTime)) { // Is there a message waiting
159 msg_ptr = b->peekMsgPtr();
160 if (flitisizeMessage(msg_ptr, vnet)) {
161 b->dequeue(curTime);
162 } else {
163 break;
164 }
165 }
166 }
167
168 scheduleOutputLink();
169 checkReschedule();
170
171 /*********** Check the incoming flit link **********/
172
173 if (inNetLink->isReady(curCycle())) {
174 flit *t_flit = inNetLink->consumeLink();
175 bool free_signal = false;
176 if (t_flit->get_type() == TAIL_ || t_flit->get_type() == HEAD_TAIL_) {
177 free_signal = true;
178
179 // enqueue into the protocol buffers
180 outNode_ptr[t_flit->get_vnet()]->enqueue(
181 t_flit->get_msg_ptr(), curTime, cyclesToTicks(Cycles(1)));
182 }
183 // Simply send a credit back since we are not buffering
184 // this flit in the NI
185 Credit *t_credit = new Credit(t_flit->get_vc(), free_signal,
186 curCycle());
187 outCreditQueue->insert(t_credit);
188 outCreditLink->
189 scheduleEventAbsolute(clockEdge(Cycles(1)));
190
191 int vnet = t_flit->get_vnet();
192
193 // Update Stats
194
195 // Latency
196 m_net_ptr->increment_received_flits(vnet);
197 Cycles network_delay = curCycle() - t_flit->get_enqueue_time();
198 Cycles queueing_delay = t_flit->get_src_delay();
199
200 m_net_ptr->increment_flit_network_latency(network_delay, vnet);
201 m_net_ptr->increment_flit_queueing_latency(queueing_delay, vnet);
202
203 if (t_flit->get_type() == TAIL_ || t_flit->get_type() == HEAD_TAIL_) {
204 m_net_ptr->increment_received_packets(vnet);
205 m_net_ptr->increment_packet_network_latency(network_delay, vnet);
206 m_net_ptr->increment_packet_queueing_latency(queueing_delay, vnet);
207 }
208
209 // Hops
210 m_net_ptr->increment_total_hops(t_flit->get_route().hops_traversed);
211
212 delete t_flit;
213 }
214
215 /****************** Check the incoming credit link *******/
216
217 if (inCreditLink->isReady(curCycle())) {
218 Credit *t_credit = (Credit*) inCreditLink->consumeLink();
219 m_out_vc_state[t_credit->get_vc()]->increment_credit();
220 if (t_credit->is_free_signal()) {
221 m_out_vc_state[t_credit->get_vc()]->setState(IDLE_, curCycle());
222 }
223 delete t_credit;
224 }
225}
226
227
228// Embed the protocol message into flits
229bool
230NetworkInterface::flitisizeMessage(MsgPtr msg_ptr, int vnet)
231{
232 Message *net_msg_ptr = msg_ptr.get();
233 NetDest net_msg_dest = net_msg_ptr->getDestination();
234
235 // gets all the destinations associated with this message.
236 vector<NodeID> dest_nodes = net_msg_dest.getAllDest();
237
238 // Number of flits is dependent on the link bandwidth available.
239 // This is expressed in terms of bytes/cycle or the flit size
240 int num_flits = (int) ceil((double) m_net_ptr->MessageSizeType_to_int(
241 net_msg_ptr->getMessageSize())/m_net_ptr->getNiFlitSize());
242
243 // loop to convert all multicast messages into unicast messages
244 for (int ctr = 0; ctr < dest_nodes.size(); ctr++) {
245
246 // this will return a free output virtual channel
247 int vc = calculateVC(vnet);
248
249 if (vc == -1) {
250 return false ;
251 }
252 MsgPtr new_msg_ptr = msg_ptr->clone();
253 NodeID destID = dest_nodes[ctr];
254
255 Message *new_net_msg_ptr = new_msg_ptr.get();
256 if (dest_nodes.size() > 1) {
257 NetDest personal_dest;
258 for (int m = 0; m < (int) MachineType_NUM; m++) {
259 if ((destID >= MachineType_base_number((MachineType) m)) &&
260 destID < MachineType_base_number((MachineType) (m+1))) {
261 // calculating the NetDest associated with this destID
262 personal_dest.clear();
263 personal_dest.add((MachineID) {(MachineType) m, (destID -
264 MachineType_base_number((MachineType) m))});
265 new_net_msg_ptr->getDestination() = personal_dest;
266 break;
267 }
268 }
269 net_msg_dest.removeNetDest(personal_dest);
270 // removing the destination from the original message to reflect
271 // that a message with this particular destination has been
272 // flitisized and an output vc is acquired
273 net_msg_ptr->getDestination().removeNetDest(personal_dest);
274 }
275
276 // Embed Route into the flits
277 // NetDest format is used by the routing table
278 // Custom routing algorithms just need destID
279 RouteInfo route;
280 route.vnet = vnet;
281 route.net_dest = new_net_msg_ptr->getDestination();
282 route.src_ni = m_id;
283 route.src_router = m_router_id;
284 route.dest_ni = destID;
285 route.dest_router = m_net_ptr->get_router_id(destID);
286
287 // initialize hops_traversed to -1
288 // so that the first router increments it to 0
289 route.hops_traversed = -1;
290
291 m_net_ptr->increment_injected_packets(vnet);
292 for (int i = 0; i < num_flits; i++) {
293 m_net_ptr->increment_injected_flits(vnet);
294 flit *fl = new flit(i, vc, vnet, route, num_flits, new_msg_ptr,
295 curCycle());
296
297 fl->set_src_delay(curCycle() - ticksToCycles(msg_ptr->getTime()));
298 m_ni_out_vcs[vc]->insert(fl);
299 }
300
301 m_ni_out_vcs_enqueue_time[vc] = curCycle();
302 m_out_vc_state[vc]->setState(ACTIVE_, curCycle());
303 }
304 return true ;
305}
306
307// Looking for a free output vc
308int
309NetworkInterface::calculateVC(int vnet)
310{
311 for (int i = 0; i < m_vc_per_vnet; i++) {
312 int delta = m_vc_allocator[vnet];
313 m_vc_allocator[vnet]++;
314 if (m_vc_allocator[vnet] == m_vc_per_vnet)
315 m_vc_allocator[vnet] = 0;
316
317 if (m_out_vc_state[(vnet*m_vc_per_vnet) + delta]->isInState(
318 IDLE_, curCycle())) {
319 vc_busy_counter[vnet] = 0;
320 return ((vnet*m_vc_per_vnet) + delta);
321 }
322 }
323
324 vc_busy_counter[vnet] += 1;
325 panic_if(vc_busy_counter[vnet] > m_deadlock_threshold,
326 "%s: Possible network deadlock in vnet: %d at time: %llu \n",
327 name(), vnet, curTick());
328
329 return -1;
330}
331
332
333/** This function looks at the NI buffers
334 * if some buffer has flits which are ready to traverse the link in the next
335 * cycle, and the downstream output vc associated with this flit has buffers
336 * left, the link is scheduled for the next cycle
337 */
338
339void
340NetworkInterface::scheduleOutputLink()
341{
342 int vc = m_vc_round_robin;
343 m_vc_round_robin++;
344 if (m_vc_round_robin == m_num_vcs)
345 m_vc_round_robin = 0;
346
347 for (int i = 0; i < m_num_vcs; i++) {
348 vc++;
349 if (vc == m_num_vcs)
350 vc = 0;
351
352 // model buffer backpressure
353 if (m_ni_out_vcs[vc]->isReady(curCycle()) &&
354 m_out_vc_state[vc]->has_credit()) {
355
356 bool is_candidate_vc = true;
357 int t_vnet = get_vnet(vc);
358 int vc_base = t_vnet * m_vc_per_vnet;
359
360 if (m_net_ptr->isVNetOrdered(t_vnet)) {
361 for (int vc_offset = 0; vc_offset < m_vc_per_vnet;
362 vc_offset++) {
363 int t_vc = vc_base + vc_offset;
364 if (m_ni_out_vcs[t_vc]->isReady(curCycle())) {
365 if (m_ni_out_vcs_enqueue_time[t_vc] <
366 m_ni_out_vcs_enqueue_time[vc]) {
367 is_candidate_vc = false;
368 break;
369 }
370 }
371 }
372 }
373 if (!is_candidate_vc)
374 continue;
375
376 m_out_vc_state[vc]->decrement_credit();
377 // Just removing the flit
378 flit *t_flit = m_ni_out_vcs[vc]->getTopFlit();
379 t_flit->set_time(curCycle() + Cycles(1));
380 outFlitQueue->insert(t_flit);
381 // schedule the out link
382 outNetLink->scheduleEventAbsolute(clockEdge(Cycles(1)));
383
384 if (t_flit->get_type() == TAIL_ ||
385 t_flit->get_type() == HEAD_TAIL_) {
386 m_ni_out_vcs_enqueue_time[vc] = Cycles(INFINITE_);
387 }
388 return;
389 }
390 }
391}
392
393int
394NetworkInterface::get_vnet(int vc)
395{
396 for (int i = 0; i < m_virtual_networks; i++) {
397 if (vc >= (i*m_vc_per_vnet) && vc < ((i+1)*m_vc_per_vnet)) {
398 return i;
399 }
400 }
401 fatal("Could not determine vc");
402}
403
404
405// Wakeup the NI in the next cycle if there are waiting
406// messages in the protocol buffer, or waiting flits in the
407// output VC buffer
408void
409NetworkInterface::checkReschedule()
410{
411 for (const auto& it : inNode_ptr) {
412 if (it == nullptr) {
413 continue;
414 }
415
416 while (it->isReady(clockEdge())) { // Is there a message waiting
417 scheduleEvent(Cycles(1));
418 return;
419 }
420 }
421
422 for (int vc = 0; vc < m_num_vcs; vc++) {
423 if (m_ni_out_vcs[vc]->isReady(curCycle() + Cycles(1))) {
424 scheduleEvent(Cycles(1));
425 return;
426 }
427 }
428}
429
430void
431NetworkInterface::print(std::ostream& out) const
432{
433 out << "[Network Interface]";
434}
435
436uint32_t
437NetworkInterface::functionalWrite(Packet *pkt)
438{
439 uint32_t num_functional_writes = 0;
440 for (unsigned int i = 0; i < m_num_vcs; ++i) {
441 num_functional_writes += m_ni_out_vcs[i]->functionalWrite(pkt);
442 }
443
444 num_functional_writes += outFlitQueue->functionalWrite(pkt);
445 return num_functional_writes;
446}
447
448NetworkInterface *
449GarnetNetworkInterfaceParams::create()
450{
451 return new NetworkInterface(this);
452}