1/*
2 * Copyright (c) 2011-2013, 2015 ARM Limited
3 * All rights reserved
4 *
5 * The license below extends only to copyright in the software and shall
6 * not be construed as granting a license to any other intellectual
7 * property including but not limited to intellectual property relating
8 * to a hardware implementation of the functionality of the software
9 * licensed hereunder. You may use the software subject to the license
10 * terms below provided that you ensure that this notice is replicated
11 * unmodified and in its entirety in all distributions of the software,
12 * modified or unmodified, in source code or in binary form.
13 *
14 * Copyright (c) 2006 The Regents of The University of Michigan
15 * All rights reserved.
16 *
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions are
19 * met: redistributions of source code must retain the above copyright
20 * notice, this list of conditions and the following disclaimer;
21 * redistributions in binary form must reproduce the above copyright
22 * notice, this list of conditions and the following disclaimer in the
23 * documentation and/or other materials provided with the distribution;
24 * neither the name of the copyright holders nor the names of its
25 * contributors may be used to endorse or promote products derived from
26 * this software without specific prior written permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
39 *
40 * Authors: Ali Saidi
41 * Steve Reinhardt
42 * Andreas Hansson
43 */
44
45/**
46 * @file
47 * Implementation of a memory-mapped bridge that connects a master
48 * and a slave through a request and response queue.
49 */
50
51#include "mem/bridge.hh"
52
53#include "base/trace.hh"
54#include "debug/Bridge.hh"
55#include "params/Bridge.hh"
56
57Bridge::BridgeSlavePort::BridgeSlavePort(const std::string& _name,
58 Bridge& _bridge,
59 BridgeMasterPort& _masterPort,
60 Cycles _delay, int _resp_limit,
61 std::vector<AddrRange> _ranges)
62 : SlavePort(_name, &_bridge), bridge(_bridge), masterPort(_masterPort),
63 delay(_delay), ranges(_ranges.begin(), _ranges.end()),
64 outstandingResponses(0), retryReq(false), respQueueLimit(_resp_limit),
65 sendEvent([this]{ trySendTiming(); }, _name)
66{
67}
68
69Bridge::BridgeMasterPort::BridgeMasterPort(const std::string& _name,
70 Bridge& _bridge,
71 BridgeSlavePort& _slavePort,
72 Cycles _delay, int _req_limit)
73 : MasterPort(_name, &_bridge), bridge(_bridge), slavePort(_slavePort),
74 delay(_delay), reqQueueLimit(_req_limit),
75 sendEvent([this]{ trySendTiming(); }, _name)
76{
77}
78
79Bridge::Bridge(Params *p)
| 1/*
2 * Copyright (c) 2011-2013, 2015 ARM Limited
3 * All rights reserved
4 *
5 * The license below extends only to copyright in the software and shall
6 * not be construed as granting a license to any other intellectual
7 * property including but not limited to intellectual property relating
8 * to a hardware implementation of the functionality of the software
9 * licensed hereunder. You may use the software subject to the license
10 * terms below provided that you ensure that this notice is replicated
11 * unmodified and in its entirety in all distributions of the software,
12 * modified or unmodified, in source code or in binary form.
13 *
14 * Copyright (c) 2006 The Regents of The University of Michigan
15 * All rights reserved.
16 *
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions are
19 * met: redistributions of source code must retain the above copyright
20 * notice, this list of conditions and the following disclaimer;
21 * redistributions in binary form must reproduce the above copyright
22 * notice, this list of conditions and the following disclaimer in the
23 * documentation and/or other materials provided with the distribution;
24 * neither the name of the copyright holders nor the names of its
25 * contributors may be used to endorse or promote products derived from
26 * this software without specific prior written permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
39 *
40 * Authors: Ali Saidi
41 * Steve Reinhardt
42 * Andreas Hansson
43 */
44
45/**
46 * @file
47 * Implementation of a memory-mapped bridge that connects a master
48 * and a slave through a request and response queue.
49 */
50
51#include "mem/bridge.hh"
52
53#include "base/trace.hh"
54#include "debug/Bridge.hh"
55#include "params/Bridge.hh"
56
57Bridge::BridgeSlavePort::BridgeSlavePort(const std::string& _name,
58 Bridge& _bridge,
59 BridgeMasterPort& _masterPort,
60 Cycles _delay, int _resp_limit,
61 std::vector<AddrRange> _ranges)
62 : SlavePort(_name, &_bridge), bridge(_bridge), masterPort(_masterPort),
63 delay(_delay), ranges(_ranges.begin(), _ranges.end()),
64 outstandingResponses(0), retryReq(false), respQueueLimit(_resp_limit),
65 sendEvent([this]{ trySendTiming(); }, _name)
66{
67}
68
69Bridge::BridgeMasterPort::BridgeMasterPort(const std::string& _name,
70 Bridge& _bridge,
71 BridgeSlavePort& _slavePort,
72 Cycles _delay, int _req_limit)
73 : MasterPort(_name, &_bridge), bridge(_bridge), slavePort(_slavePort),
74 delay(_delay), reqQueueLimit(_req_limit),
75 sendEvent([this]{ trySendTiming(); }, _name)
76{
77}
78
79Bridge::Bridge(Params *p)
|
80 : MemObject(p),
| 80 : ClockedObject(p),
|
81 slavePort(p->name + ".slave", *this, masterPort,
82 ticksToCycles(p->delay), p->resp_size, p->ranges),
83 masterPort(p->name + ".master", *this, slavePort,
84 ticksToCycles(p->delay), p->req_size)
85{
86}
87
88Port &
89Bridge::getPort(const std::string &if_name, PortID idx)
90{
91 if (if_name == "master")
92 return masterPort;
93 else if (if_name == "slave")
94 return slavePort;
95 else
96 // pass it along to our super class
| 81 slavePort(p->name + ".slave", *this, masterPort,
82 ticksToCycles(p->delay), p->resp_size, p->ranges),
83 masterPort(p->name + ".master", *this, slavePort,
84 ticksToCycles(p->delay), p->req_size)
85{
86}
87
88Port &
89Bridge::getPort(const std::string &if_name, PortID idx)
90{
91 if (if_name == "master")
92 return masterPort;
93 else if (if_name == "slave")
94 return slavePort;
95 else
96 // pass it along to our super class
|
97 return MemObject::getPort(if_name, idx);
| 97 return ClockedObject::getPort(if_name, idx);
|
98}
99
100void
101Bridge::init()
102{
103 // make sure both sides are connected and have the same block size
104 if (!slavePort.isConnected() || !masterPort.isConnected())
105 fatal("Both ports of a bridge must be connected.\n");
106
107 // notify the master side of our address ranges
108 slavePort.sendRangeChange();
109}
110
111bool
112Bridge::BridgeSlavePort::respQueueFull() const
113{
114 return outstandingResponses == respQueueLimit;
115}
116
117bool
118Bridge::BridgeMasterPort::reqQueueFull() const
119{
120 return transmitList.size() == reqQueueLimit;
121}
122
123bool
124Bridge::BridgeMasterPort::recvTimingResp(PacketPtr pkt)
125{
126 // all checks are done when the request is accepted on the slave
127 // side, so we are guaranteed to have space for the response
128 DPRINTF(Bridge, "recvTimingResp: %s addr 0x%x\n",
129 pkt->cmdString(), pkt->getAddr());
130
131 DPRINTF(Bridge, "Request queue size: %d\n", transmitList.size());
132
133 // technically the packet only reaches us after the header delay,
134 // and typically we also need to deserialise any payload (unless
135 // the two sides of the bridge are synchronous)
136 Tick receive_delay = pkt->headerDelay + pkt->payloadDelay;
137 pkt->headerDelay = pkt->payloadDelay = 0;
138
139 slavePort.schedTimingResp(pkt, bridge.clockEdge(delay) +
140 receive_delay);
141
142 return true;
143}
144
145bool
146Bridge::BridgeSlavePort::recvTimingReq(PacketPtr pkt)
147{
148 DPRINTF(Bridge, "recvTimingReq: %s addr 0x%x\n",
149 pkt->cmdString(), pkt->getAddr());
150
151 panic_if(pkt->cacheResponding(), "Should not see packets where cache "
152 "is responding");
153
154 // we should not get a new request after committing to retry the
155 // current one, but unfortunately the CPU violates this rule, so
156 // simply ignore it for now
157 if (retryReq)
158 return false;
159
160 DPRINTF(Bridge, "Response queue size: %d outresp: %d\n",
161 transmitList.size(), outstandingResponses);
162
163 // if the request queue is full then there is no hope
164 if (masterPort.reqQueueFull()) {
165 DPRINTF(Bridge, "Request queue full\n");
166 retryReq = true;
167 } else {
168 // look at the response queue if we expect to see a response
169 bool expects_response = pkt->needsResponse();
170 if (expects_response) {
171 if (respQueueFull()) {
172 DPRINTF(Bridge, "Response queue full\n");
173 retryReq = true;
174 } else {
175 // ok to send the request with space for the response
176 DPRINTF(Bridge, "Reserving space for response\n");
177 assert(outstandingResponses != respQueueLimit);
178 ++outstandingResponses;
179
180 // no need to set retryReq to false as this is already the
181 // case
182 }
183 }
184
185 if (!retryReq) {
186 // technically the packet only reaches us after the header
187 // delay, and typically we also need to deserialise any
188 // payload (unless the two sides of the bridge are
189 // synchronous)
190 Tick receive_delay = pkt->headerDelay + pkt->payloadDelay;
191 pkt->headerDelay = pkt->payloadDelay = 0;
192
193 masterPort.schedTimingReq(pkt, bridge.clockEdge(delay) +
194 receive_delay);
195 }
196 }
197
198 // remember that we are now stalling a packet and that we have to
199 // tell the sending master to retry once space becomes available,
200 // we make no distinction whether the stalling is due to the
201 // request queue or response queue being full
202 return !retryReq;
203}
204
205void
206Bridge::BridgeSlavePort::retryStalledReq()
207{
208 if (retryReq) {
209 DPRINTF(Bridge, "Request waiting for retry, now retrying\n");
210 retryReq = false;
211 sendRetryReq();
212 }
213}
214
215void
216Bridge::BridgeMasterPort::schedTimingReq(PacketPtr pkt, Tick when)
217{
218 // If we're about to put this packet at the head of the queue, we
219 // need to schedule an event to do the transmit. Otherwise there
220 // should already be an event scheduled for sending the head
221 // packet.
222 if (transmitList.empty()) {
223 bridge.schedule(sendEvent, when);
224 }
225
226 assert(transmitList.size() != reqQueueLimit);
227
228 transmitList.emplace_back(pkt, when);
229}
230
231
232void
233Bridge::BridgeSlavePort::schedTimingResp(PacketPtr pkt, Tick when)
234{
235 // If we're about to put this packet at the head of the queue, we
236 // need to schedule an event to do the transmit. Otherwise there
237 // should already be an event scheduled for sending the head
238 // packet.
239 if (transmitList.empty()) {
240 bridge.schedule(sendEvent, when);
241 }
242
243 transmitList.emplace_back(pkt, when);
244}
245
246void
247Bridge::BridgeMasterPort::trySendTiming()
248{
249 assert(!transmitList.empty());
250
251 DeferredPacket req = transmitList.front();
252
253 assert(req.tick <= curTick());
254
255 PacketPtr pkt = req.pkt;
256
257 DPRINTF(Bridge, "trySend request addr 0x%x, queue size %d\n",
258 pkt->getAddr(), transmitList.size());
259
260 if (sendTimingReq(pkt)) {
261 // send successful
262 transmitList.pop_front();
263 DPRINTF(Bridge, "trySend request successful\n");
264
265 // If there are more packets to send, schedule event to try again.
266 if (!transmitList.empty()) {
267 DeferredPacket next_req = transmitList.front();
268 DPRINTF(Bridge, "Scheduling next send\n");
269 bridge.schedule(sendEvent, std::max(next_req.tick,
270 bridge.clockEdge()));
271 }
272
273 // if we have stalled a request due to a full request queue,
274 // then send a retry at this point, also note that if the
275 // request we stalled was waiting for the response queue
276 // rather than the request queue we might stall it again
277 slavePort.retryStalledReq();
278 }
279
280 // if the send failed, then we try again once we receive a retry,
281 // and therefore there is no need to take any action
282}
283
284void
285Bridge::BridgeSlavePort::trySendTiming()
286{
287 assert(!transmitList.empty());
288
289 DeferredPacket resp = transmitList.front();
290
291 assert(resp.tick <= curTick());
292
293 PacketPtr pkt = resp.pkt;
294
295 DPRINTF(Bridge, "trySend response addr 0x%x, outstanding %d\n",
296 pkt->getAddr(), outstandingResponses);
297
298 if (sendTimingResp(pkt)) {
299 // send successful
300 transmitList.pop_front();
301 DPRINTF(Bridge, "trySend response successful\n");
302
303 assert(outstandingResponses != 0);
304 --outstandingResponses;
305
306 // If there are more packets to send, schedule event to try again.
307 if (!transmitList.empty()) {
308 DeferredPacket next_resp = transmitList.front();
309 DPRINTF(Bridge, "Scheduling next send\n");
310 bridge.schedule(sendEvent, std::max(next_resp.tick,
311 bridge.clockEdge()));
312 }
313
314 // if there is space in the request queue and we were stalling
315 // a request, it will definitely be possible to accept it now
316 // since there is guaranteed space in the response queue
317 if (!masterPort.reqQueueFull() && retryReq) {
318 DPRINTF(Bridge, "Request waiting for retry, now retrying\n");
319 retryReq = false;
320 sendRetryReq();
321 }
322 }
323
324 // if the send failed, then we try again once we receive a retry,
325 // and therefore there is no need to take any action
326}
327
328void
329Bridge::BridgeMasterPort::recvReqRetry()
330{
331 trySendTiming();
332}
333
334void
335Bridge::BridgeSlavePort::recvRespRetry()
336{
337 trySendTiming();
338}
339
340Tick
341Bridge::BridgeSlavePort::recvAtomic(PacketPtr pkt)
342{
343 panic_if(pkt->cacheResponding(), "Should not see packets where cache "
344 "is responding");
345
346 return delay * bridge.clockPeriod() + masterPort.sendAtomic(pkt);
347}
348
349void
350Bridge::BridgeSlavePort::recvFunctional(PacketPtr pkt)
351{
352 pkt->pushLabel(name());
353
354 // check the response queue
355 for (auto i = transmitList.begin(); i != transmitList.end(); ++i) {
356 if (pkt->trySatisfyFunctional((*i).pkt)) {
357 pkt->makeResponse();
358 return;
359 }
360 }
361
362 // also check the master port's request queue
363 if (masterPort.trySatisfyFunctional(pkt)) {
364 return;
365 }
366
367 pkt->popLabel();
368
369 // fall through if pkt still not satisfied
370 masterPort.sendFunctional(pkt);
371}
372
373bool
374Bridge::BridgeMasterPort::trySatisfyFunctional(PacketPtr pkt)
375{
376 bool found = false;
377 auto i = transmitList.begin();
378
379 while (i != transmitList.end() && !found) {
380 if (pkt->trySatisfyFunctional((*i).pkt)) {
381 pkt->makeResponse();
382 found = true;
383 }
384 ++i;
385 }
386
387 return found;
388}
389
390AddrRangeList
391Bridge::BridgeSlavePort::getAddrRanges() const
392{
393 return ranges;
394}
395
396Bridge *
397BridgeParams::create()
398{
399 return new Bridge(this);
400}
| 98}
99
100void
101Bridge::init()
102{
103 // make sure both sides are connected and have the same block size
104 if (!slavePort.isConnected() || !masterPort.isConnected())
105 fatal("Both ports of a bridge must be connected.\n");
106
107 // notify the master side of our address ranges
108 slavePort.sendRangeChange();
109}
110
111bool
112Bridge::BridgeSlavePort::respQueueFull() const
113{
114 return outstandingResponses == respQueueLimit;
115}
116
117bool
118Bridge::BridgeMasterPort::reqQueueFull() const
119{
120 return transmitList.size() == reqQueueLimit;
121}
122
123bool
124Bridge::BridgeMasterPort::recvTimingResp(PacketPtr pkt)
125{
126 // all checks are done when the request is accepted on the slave
127 // side, so we are guaranteed to have space for the response
128 DPRINTF(Bridge, "recvTimingResp: %s addr 0x%x\n",
129 pkt->cmdString(), pkt->getAddr());
130
131 DPRINTF(Bridge, "Request queue size: %d\n", transmitList.size());
132
133 // technically the packet only reaches us after the header delay,
134 // and typically we also need to deserialise any payload (unless
135 // the two sides of the bridge are synchronous)
136 Tick receive_delay = pkt->headerDelay + pkt->payloadDelay;
137 pkt->headerDelay = pkt->payloadDelay = 0;
138
139 slavePort.schedTimingResp(pkt, bridge.clockEdge(delay) +
140 receive_delay);
141
142 return true;
143}
144
145bool
146Bridge::BridgeSlavePort::recvTimingReq(PacketPtr pkt)
147{
148 DPRINTF(Bridge, "recvTimingReq: %s addr 0x%x\n",
149 pkt->cmdString(), pkt->getAddr());
150
151 panic_if(pkt->cacheResponding(), "Should not see packets where cache "
152 "is responding");
153
154 // we should not get a new request after committing to retry the
155 // current one, but unfortunately the CPU violates this rule, so
156 // simply ignore it for now
157 if (retryReq)
158 return false;
159
160 DPRINTF(Bridge, "Response queue size: %d outresp: %d\n",
161 transmitList.size(), outstandingResponses);
162
163 // if the request queue is full then there is no hope
164 if (masterPort.reqQueueFull()) {
165 DPRINTF(Bridge, "Request queue full\n");
166 retryReq = true;
167 } else {
168 // look at the response queue if we expect to see a response
169 bool expects_response = pkt->needsResponse();
170 if (expects_response) {
171 if (respQueueFull()) {
172 DPRINTF(Bridge, "Response queue full\n");
173 retryReq = true;
174 } else {
175 // ok to send the request with space for the response
176 DPRINTF(Bridge, "Reserving space for response\n");
177 assert(outstandingResponses != respQueueLimit);
178 ++outstandingResponses;
179
180 // no need to set retryReq to false as this is already the
181 // case
182 }
183 }
184
185 if (!retryReq) {
186 // technically the packet only reaches us after the header
187 // delay, and typically we also need to deserialise any
188 // payload (unless the two sides of the bridge are
189 // synchronous)
190 Tick receive_delay = pkt->headerDelay + pkt->payloadDelay;
191 pkt->headerDelay = pkt->payloadDelay = 0;
192
193 masterPort.schedTimingReq(pkt, bridge.clockEdge(delay) +
194 receive_delay);
195 }
196 }
197
198 // remember that we are now stalling a packet and that we have to
199 // tell the sending master to retry once space becomes available,
200 // we make no distinction whether the stalling is due to the
201 // request queue or response queue being full
202 return !retryReq;
203}
204
205void
206Bridge::BridgeSlavePort::retryStalledReq()
207{
208 if (retryReq) {
209 DPRINTF(Bridge, "Request waiting for retry, now retrying\n");
210 retryReq = false;
211 sendRetryReq();
212 }
213}
214
215void
216Bridge::BridgeMasterPort::schedTimingReq(PacketPtr pkt, Tick when)
217{
218 // If we're about to put this packet at the head of the queue, we
219 // need to schedule an event to do the transmit. Otherwise there
220 // should already be an event scheduled for sending the head
221 // packet.
222 if (transmitList.empty()) {
223 bridge.schedule(sendEvent, when);
224 }
225
226 assert(transmitList.size() != reqQueueLimit);
227
228 transmitList.emplace_back(pkt, when);
229}
230
231
232void
233Bridge::BridgeSlavePort::schedTimingResp(PacketPtr pkt, Tick when)
234{
235 // If we're about to put this packet at the head of the queue, we
236 // need to schedule an event to do the transmit. Otherwise there
237 // should already be an event scheduled for sending the head
238 // packet.
239 if (transmitList.empty()) {
240 bridge.schedule(sendEvent, when);
241 }
242
243 transmitList.emplace_back(pkt, when);
244}
245
246void
247Bridge::BridgeMasterPort::trySendTiming()
248{
249 assert(!transmitList.empty());
250
251 DeferredPacket req = transmitList.front();
252
253 assert(req.tick <= curTick());
254
255 PacketPtr pkt = req.pkt;
256
257 DPRINTF(Bridge, "trySend request addr 0x%x, queue size %d\n",
258 pkt->getAddr(), transmitList.size());
259
260 if (sendTimingReq(pkt)) {
261 // send successful
262 transmitList.pop_front();
263 DPRINTF(Bridge, "trySend request successful\n");
264
265 // If there are more packets to send, schedule event to try again.
266 if (!transmitList.empty()) {
267 DeferredPacket next_req = transmitList.front();
268 DPRINTF(Bridge, "Scheduling next send\n");
269 bridge.schedule(sendEvent, std::max(next_req.tick,
270 bridge.clockEdge()));
271 }
272
273 // if we have stalled a request due to a full request queue,
274 // then send a retry at this point, also note that if the
275 // request we stalled was waiting for the response queue
276 // rather than the request queue we might stall it again
277 slavePort.retryStalledReq();
278 }
279
280 // if the send failed, then we try again once we receive a retry,
281 // and therefore there is no need to take any action
282}
283
284void
285Bridge::BridgeSlavePort::trySendTiming()
286{
287 assert(!transmitList.empty());
288
289 DeferredPacket resp = transmitList.front();
290
291 assert(resp.tick <= curTick());
292
293 PacketPtr pkt = resp.pkt;
294
295 DPRINTF(Bridge, "trySend response addr 0x%x, outstanding %d\n",
296 pkt->getAddr(), outstandingResponses);
297
298 if (sendTimingResp(pkt)) {
299 // send successful
300 transmitList.pop_front();
301 DPRINTF(Bridge, "trySend response successful\n");
302
303 assert(outstandingResponses != 0);
304 --outstandingResponses;
305
306 // If there are more packets to send, schedule event to try again.
307 if (!transmitList.empty()) {
308 DeferredPacket next_resp = transmitList.front();
309 DPRINTF(Bridge, "Scheduling next send\n");
310 bridge.schedule(sendEvent, std::max(next_resp.tick,
311 bridge.clockEdge()));
312 }
313
314 // if there is space in the request queue and we were stalling
315 // a request, it will definitely be possible to accept it now
316 // since there is guaranteed space in the response queue
317 if (!masterPort.reqQueueFull() && retryReq) {
318 DPRINTF(Bridge, "Request waiting for retry, now retrying\n");
319 retryReq = false;
320 sendRetryReq();
321 }
322 }
323
324 // if the send failed, then we try again once we receive a retry,
325 // and therefore there is no need to take any action
326}
327
328void
329Bridge::BridgeMasterPort::recvReqRetry()
330{
331 trySendTiming();
332}
333
334void
335Bridge::BridgeSlavePort::recvRespRetry()
336{
337 trySendTiming();
338}
339
340Tick
341Bridge::BridgeSlavePort::recvAtomic(PacketPtr pkt)
342{
343 panic_if(pkt->cacheResponding(), "Should not see packets where cache "
344 "is responding");
345
346 return delay * bridge.clockPeriod() + masterPort.sendAtomic(pkt);
347}
348
349void
350Bridge::BridgeSlavePort::recvFunctional(PacketPtr pkt)
351{
352 pkt->pushLabel(name());
353
354 // check the response queue
355 for (auto i = transmitList.begin(); i != transmitList.end(); ++i) {
356 if (pkt->trySatisfyFunctional((*i).pkt)) {
357 pkt->makeResponse();
358 return;
359 }
360 }
361
362 // also check the master port's request queue
363 if (masterPort.trySatisfyFunctional(pkt)) {
364 return;
365 }
366
367 pkt->popLabel();
368
369 // fall through if pkt still not satisfied
370 masterPort.sendFunctional(pkt);
371}
372
373bool
374Bridge::BridgeMasterPort::trySatisfyFunctional(PacketPtr pkt)
375{
376 bool found = false;
377 auto i = transmitList.begin();
378
379 while (i != transmitList.end() && !found) {
380 if (pkt->trySatisfyFunctional((*i).pkt)) {
381 pkt->makeResponse();
382 found = true;
383 }
384 ++i;
385 }
386
387 return found;
388}
389
390AddrRangeList
391Bridge::BridgeSlavePort::getAddrRanges() const
392{
393 return ranges;
394}
395
396Bridge *
397BridgeParams::create()
398{
399 return new Bridge(this);
400}
|