bridge.cc (8922:17f037ad8918) bridge.cc (8948:e95ee70f876c)
1/*
2 * Copyright (c) 2011-2012 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 bus bridge that connects a master
48 * and a slave through a request and response queue.
49 */
50
51#include "base/trace.hh"
52#include "debug/BusBridge.hh"
53#include "mem/bridge.hh"
54#include "params/Bridge.hh"
55
56Bridge::BridgeSlavePort::BridgeSlavePort(const std::string &_name,
57 Bridge* _bridge,
58 BridgeMasterPort& _masterPort,
59 int _delay, int _nack_delay,
60 int _resp_limit,
61 std::vector<Range<Addr> > _ranges)
62 : SlavePort(_name, _bridge), bridge(_bridge), masterPort(_masterPort),
63 delay(_delay), nackDelay(_nack_delay),
64 ranges(_ranges.begin(), _ranges.end()),
65 outstandingResponses(0), inRetry(false),
66 respQueueLimit(_resp_limit), sendEvent(*this)
67{
68}
69
70Bridge::BridgeMasterPort::BridgeMasterPort(const std::string &_name,
71 Bridge* _bridge,
72 BridgeSlavePort& _slavePort,
73 int _delay, int _req_limit)
74 : MasterPort(_name, _bridge), bridge(_bridge), slavePort(_slavePort),
75 delay(_delay), inRetry(false), reqQueueLimit(_req_limit),
76 sendEvent(*this)
77{
78}
79
80Bridge::Bridge(Params *p)
81 : MemObject(p),
82 slavePort(p->name + "-slave", this, masterPort, p->delay,
83 p->nack_delay, p->resp_size, p->ranges),
84 masterPort(p->name + "-master", this, slavePort, p->delay, p->req_size),
85 ackWrites(p->write_ack), _params(p)
86{
87 if (ackWrites)
88 panic("No support for acknowledging writes\n");
89}
90
91MasterPort&
92Bridge::getMasterPort(const std::string &if_name, int idx)
93{
94 if (if_name == "master")
95 return masterPort;
96 else
97 // pass it along to our super class
98 return MemObject::getMasterPort(if_name, idx);
99}
100
101SlavePort&
102Bridge::getSlavePort(const std::string &if_name, int idx)
103{
104 if (if_name == "slave")
105 return slavePort;
106 else
107 // pass it along to our super class
108 return MemObject::getSlavePort(if_name, idx);
109}
110
111void
112Bridge::init()
113{
114 // make sure both sides are connected and have the same block size
115 if (!slavePort.isConnected() || !masterPort.isConnected())
116 fatal("Both ports of bus bridge are not connected to a bus.\n");
117
118 if (slavePort.peerBlockSize() != masterPort.peerBlockSize())
119 fatal("Slave port size %d, master port size %d \n " \
120 "Busses don't have the same block size... Not supported.\n",
121 slavePort.peerBlockSize(), masterPort.peerBlockSize());
122
123 // notify the master side of our address ranges
124 slavePort.sendRangeChange();
125}
126
127bool
128Bridge::BridgeSlavePort::respQueueFull()
129{
130 return outstandingResponses == respQueueLimit;
131}
132
133bool
134Bridge::BridgeMasterPort::reqQueueFull()
135{
136 return requestQueue.size() == reqQueueLimit;
137}
138
139bool
140Bridge::BridgeMasterPort::recvTiming(PacketPtr pkt)
141{
142 // should only see responses on the master side
143 assert(pkt->isResponse());
144
145 // all checks are done when the request is accepted on the slave
146 // side, so we are guaranteed to have space for the response
147
148 DPRINTF(BusBridge, "recvTiming: src %d dest %d addr 0x%x\n",
149 pkt->getSrc(), pkt->getDest(), pkt->getAddr());
150
151 DPRINTF(BusBridge, "Request queue size: %d\n", requestQueue.size());
152
153 slavePort.queueForSendTiming(pkt);
154
155 return true;
156}
157
158bool
159Bridge::BridgeSlavePort::recvTiming(PacketPtr pkt)
160{
161 // should only see requests on the slave side
162 assert(pkt->isRequest());
163
164 DPRINTF(BusBridge, "recvTiming: src %d dest %d addr 0x%x\n",
165 pkt->getSrc(), pkt->getDest(), pkt->getAddr());
166
167 DPRINTF(BusBridge, "Response queue size: %d outresp: %d\n",
168 responseQueue.size(), outstandingResponses);
169
170 if (masterPort.reqQueueFull()) {
171 DPRINTF(BusBridge, "Request queue full, nacking\n");
172 nackRequest(pkt);
173 return true;
174 }
175
176 if (pkt->needsResponse()) {
177 if (respQueueFull()) {
178 DPRINTF(BusBridge,
179 "Response queue full, no space for response, nacking\n");
180 DPRINTF(BusBridge,
181 "queue size: %d outstanding resp: %d\n",
182 responseQueue.size(), outstandingResponses);
183 nackRequest(pkt);
184 return true;
185 } else {
186 DPRINTF(BusBridge, "Request Needs response, reserving space\n");
187 assert(outstandingResponses != respQueueLimit);
188 ++outstandingResponses;
189 }
190 }
191
192 masterPort.queueForSendTiming(pkt);
193
194 return true;
195}
196
197void
198Bridge::BridgeSlavePort::nackRequest(PacketPtr pkt)
199{
200 // Nack the packet
201 pkt->makeTimingResponse();
202 pkt->setNacked();
203
204 // The Nack packets are stored in the response queue just like any
205 // other response, but they do not occupy any space as this is
206 // tracked by the outstandingResponses, this guarantees space for
207 // the Nack packets, but implicitly means we have an (unrealistic)
208 // unbounded Nack queue.
209
210 // put it on the list to send
211 Tick readyTime = curTick() + nackDelay;
212 PacketBuffer *buf = new PacketBuffer(pkt, readyTime, true);
213
214 // nothing on the list, add it and we're done
215 if (responseQueue.empty()) {
216 assert(!sendEvent.scheduled());
217 bridge->schedule(sendEvent, readyTime);
218 responseQueue.push_back(buf);
219 return;
220 }
221
222 assert(sendEvent.scheduled() || inRetry);
223
224 // does it go at the end?
225 if (readyTime >= responseQueue.back()->ready) {
226 responseQueue.push_back(buf);
227 return;
228 }
229
230 // ok, somewhere in the middle, fun
231 std::list<PacketBuffer*>::iterator i = responseQueue.begin();
232 std::list<PacketBuffer*>::iterator end = responseQueue.end();
233 std::list<PacketBuffer*>::iterator begin = responseQueue.begin();
234 bool done = false;
235
236 while (i != end && !done) {
237 if (readyTime < (*i)->ready) {
238 if (i == begin)
239 bridge->reschedule(sendEvent, readyTime);
240 responseQueue.insert(i,buf);
241 done = true;
242 }
243 i++;
244 }
245 assert(done);
246}
247
248void
249Bridge::BridgeMasterPort::queueForSendTiming(PacketPtr pkt)
250{
251 Tick readyTime = curTick() + delay;
252 PacketBuffer *buf = new PacketBuffer(pkt, readyTime);
253
254 // If we're about to put this packet at the head of the queue, we
255 // need to schedule an event to do the transmit. Otherwise there
256 // should already be an event scheduled for sending the head
257 // packet.
258 if (requestQueue.empty()) {
259 bridge->schedule(sendEvent, readyTime);
260 }
261
262 assert(requestQueue.size() != reqQueueLimit);
263
264 requestQueue.push_back(buf);
265}
266
267
268void
269Bridge::BridgeSlavePort::queueForSendTiming(PacketPtr pkt)
270{
271 // This is a response for a request we forwarded earlier. The
272 // corresponding PacketBuffer should be stored in the packet's
273 // senderState field.
274 PacketBuffer *buf = dynamic_cast<PacketBuffer*>(pkt->senderState);
275 assert(buf != NULL);
276 // set up new packet dest & senderState based on values saved
277 // from original request
278 buf->fixResponse(pkt);
279
280 DPRINTF(BusBridge, "response, new dest %d\n", pkt->getDest());
281 delete buf;
282
283 Tick readyTime = curTick() + delay;
284 buf = new PacketBuffer(pkt, readyTime);
285
286 // If we're about to put this packet at the head of the queue, we
287 // need to schedule an event to do the transmit. Otherwise there
288 // should already be an event scheduled for sending the head
289 // packet.
290 if (responseQueue.empty()) {
291 bridge->schedule(sendEvent, readyTime);
292 }
293 responseQueue.push_back(buf);
294}
295
296void
297Bridge::BridgeMasterPort::trySend()
298{
299 assert(!requestQueue.empty());
300
301 PacketBuffer *buf = requestQueue.front();
302
303 assert(buf->ready <= curTick());
304
305 PacketPtr pkt = buf->pkt;
306
307 DPRINTF(BusBridge, "trySend: origSrc %d dest %d addr 0x%x\n",
308 buf->origSrc, pkt->getDest(), pkt->getAddr());
309
310 // If the send was successful, make sure sender state was set to NULL
311 // otherwise we could get a NACK back of a packet that didn't expect a
312 // response and we would try to use freed memory.
313
314 Packet::SenderState *old_sender_state = pkt->senderState;
315 if (!buf->expectResponse)
316 pkt->senderState = NULL;
317
318 if (sendTiming(pkt)) {
319 // send successful
320 requestQueue.pop_front();
321 // we no longer own packet, so it's not safe to look at it
322 buf->pkt = NULL;
323
324 if (!buf->expectResponse) {
325 // no response expected... deallocate packet buffer now.
326 DPRINTF(BusBridge, " successful: no response expected\n");
327 delete buf;
328 }
329
330 // If there are more packets to send, schedule event to try again.
331 if (!requestQueue.empty()) {
332 buf = requestQueue.front();
333 DPRINTF(BusBridge, "Scheduling next send\n");
334 bridge->schedule(sendEvent, std::max(buf->ready, curTick() + 1));
335 }
336 } else {
337 DPRINTF(BusBridge, " unsuccessful\n");
338 pkt->senderState = old_sender_state;
339 inRetry = true;
340 }
341
342 DPRINTF(BusBridge, "trySend: request queue size: %d\n",
343 requestQueue.size());
344}
345
346void
347Bridge::BridgeSlavePort::trySend()
348{
349 assert(!responseQueue.empty());
350
351 PacketBuffer *buf = responseQueue.front();
352
353 assert(buf->ready <= curTick());
354
355 PacketPtr pkt = buf->pkt;
356
357 DPRINTF(BusBridge, "trySend: origSrc %d dest %d addr 0x%x\n",
358 buf->origSrc, pkt->getDest(), pkt->getAddr());
359
360 bool was_nacked_here = buf->nackedHere;
361
362 // no need to worry about the sender state since we are not
363 // modifying it
364
365 if (sendTiming(pkt)) {
366 DPRINTF(BusBridge, " successful\n");
367 // send successful
368 responseQueue.pop_front();
369 // this is a response... deallocate packet buffer now.
370 delete buf;
371
372 if (!was_nacked_here) {
373 assert(outstandingResponses != 0);
374 --outstandingResponses;
375 }
376
377 // If there are more packets to send, schedule event to try again.
378 if (!responseQueue.empty()) {
379 buf = responseQueue.front();
380 DPRINTF(BusBridge, "Scheduling next send\n");
381 bridge->schedule(sendEvent, std::max(buf->ready, curTick() + 1));
382 }
383 } else {
384 DPRINTF(BusBridge, " unsuccessful\n");
385 inRetry = true;
386 }
387
388 DPRINTF(BusBridge, "trySend: queue size: %d outstanding resp: %d\n",
389 responseQueue.size(), outstandingResponses);
390}
391
392void
393Bridge::BridgeMasterPort::recvRetry()
394{
395 inRetry = false;
396 Tick nextReady = requestQueue.front()->ready;
397 if (nextReady <= curTick())
398 trySend();
399 else
400 bridge->schedule(sendEvent, nextReady);
401}
402
403void
404Bridge::BridgeSlavePort::recvRetry()
405{
406 inRetry = false;
407 Tick nextReady = responseQueue.front()->ready;
408 if (nextReady <= curTick())
409 trySend();
410 else
411 bridge->schedule(sendEvent, nextReady);
412}
413
414Tick
1/*
2 * Copyright (c) 2011-2012 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 bus bridge that connects a master
48 * and a slave through a request and response queue.
49 */
50
51#include "base/trace.hh"
52#include "debug/BusBridge.hh"
53#include "mem/bridge.hh"
54#include "params/Bridge.hh"
55
56Bridge::BridgeSlavePort::BridgeSlavePort(const std::string &_name,
57 Bridge* _bridge,
58 BridgeMasterPort& _masterPort,
59 int _delay, int _nack_delay,
60 int _resp_limit,
61 std::vector<Range<Addr> > _ranges)
62 : SlavePort(_name, _bridge), bridge(_bridge), masterPort(_masterPort),
63 delay(_delay), nackDelay(_nack_delay),
64 ranges(_ranges.begin(), _ranges.end()),
65 outstandingResponses(0), inRetry(false),
66 respQueueLimit(_resp_limit), sendEvent(*this)
67{
68}
69
70Bridge::BridgeMasterPort::BridgeMasterPort(const std::string &_name,
71 Bridge* _bridge,
72 BridgeSlavePort& _slavePort,
73 int _delay, int _req_limit)
74 : MasterPort(_name, _bridge), bridge(_bridge), slavePort(_slavePort),
75 delay(_delay), inRetry(false), reqQueueLimit(_req_limit),
76 sendEvent(*this)
77{
78}
79
80Bridge::Bridge(Params *p)
81 : MemObject(p),
82 slavePort(p->name + "-slave", this, masterPort, p->delay,
83 p->nack_delay, p->resp_size, p->ranges),
84 masterPort(p->name + "-master", this, slavePort, p->delay, p->req_size),
85 ackWrites(p->write_ack), _params(p)
86{
87 if (ackWrites)
88 panic("No support for acknowledging writes\n");
89}
90
91MasterPort&
92Bridge::getMasterPort(const std::string &if_name, int idx)
93{
94 if (if_name == "master")
95 return masterPort;
96 else
97 // pass it along to our super class
98 return MemObject::getMasterPort(if_name, idx);
99}
100
101SlavePort&
102Bridge::getSlavePort(const std::string &if_name, int idx)
103{
104 if (if_name == "slave")
105 return slavePort;
106 else
107 // pass it along to our super class
108 return MemObject::getSlavePort(if_name, idx);
109}
110
111void
112Bridge::init()
113{
114 // make sure both sides are connected and have the same block size
115 if (!slavePort.isConnected() || !masterPort.isConnected())
116 fatal("Both ports of bus bridge are not connected to a bus.\n");
117
118 if (slavePort.peerBlockSize() != masterPort.peerBlockSize())
119 fatal("Slave port size %d, master port size %d \n " \
120 "Busses don't have the same block size... Not supported.\n",
121 slavePort.peerBlockSize(), masterPort.peerBlockSize());
122
123 // notify the master side of our address ranges
124 slavePort.sendRangeChange();
125}
126
127bool
128Bridge::BridgeSlavePort::respQueueFull()
129{
130 return outstandingResponses == respQueueLimit;
131}
132
133bool
134Bridge::BridgeMasterPort::reqQueueFull()
135{
136 return requestQueue.size() == reqQueueLimit;
137}
138
139bool
140Bridge::BridgeMasterPort::recvTiming(PacketPtr pkt)
141{
142 // should only see responses on the master side
143 assert(pkt->isResponse());
144
145 // all checks are done when the request is accepted on the slave
146 // side, so we are guaranteed to have space for the response
147
148 DPRINTF(BusBridge, "recvTiming: src %d dest %d addr 0x%x\n",
149 pkt->getSrc(), pkt->getDest(), pkt->getAddr());
150
151 DPRINTF(BusBridge, "Request queue size: %d\n", requestQueue.size());
152
153 slavePort.queueForSendTiming(pkt);
154
155 return true;
156}
157
158bool
159Bridge::BridgeSlavePort::recvTiming(PacketPtr pkt)
160{
161 // should only see requests on the slave side
162 assert(pkt->isRequest());
163
164 DPRINTF(BusBridge, "recvTiming: src %d dest %d addr 0x%x\n",
165 pkt->getSrc(), pkt->getDest(), pkt->getAddr());
166
167 DPRINTF(BusBridge, "Response queue size: %d outresp: %d\n",
168 responseQueue.size(), outstandingResponses);
169
170 if (masterPort.reqQueueFull()) {
171 DPRINTF(BusBridge, "Request queue full, nacking\n");
172 nackRequest(pkt);
173 return true;
174 }
175
176 if (pkt->needsResponse()) {
177 if (respQueueFull()) {
178 DPRINTF(BusBridge,
179 "Response queue full, no space for response, nacking\n");
180 DPRINTF(BusBridge,
181 "queue size: %d outstanding resp: %d\n",
182 responseQueue.size(), outstandingResponses);
183 nackRequest(pkt);
184 return true;
185 } else {
186 DPRINTF(BusBridge, "Request Needs response, reserving space\n");
187 assert(outstandingResponses != respQueueLimit);
188 ++outstandingResponses;
189 }
190 }
191
192 masterPort.queueForSendTiming(pkt);
193
194 return true;
195}
196
197void
198Bridge::BridgeSlavePort::nackRequest(PacketPtr pkt)
199{
200 // Nack the packet
201 pkt->makeTimingResponse();
202 pkt->setNacked();
203
204 // The Nack packets are stored in the response queue just like any
205 // other response, but they do not occupy any space as this is
206 // tracked by the outstandingResponses, this guarantees space for
207 // the Nack packets, but implicitly means we have an (unrealistic)
208 // unbounded Nack queue.
209
210 // put it on the list to send
211 Tick readyTime = curTick() + nackDelay;
212 PacketBuffer *buf = new PacketBuffer(pkt, readyTime, true);
213
214 // nothing on the list, add it and we're done
215 if (responseQueue.empty()) {
216 assert(!sendEvent.scheduled());
217 bridge->schedule(sendEvent, readyTime);
218 responseQueue.push_back(buf);
219 return;
220 }
221
222 assert(sendEvent.scheduled() || inRetry);
223
224 // does it go at the end?
225 if (readyTime >= responseQueue.back()->ready) {
226 responseQueue.push_back(buf);
227 return;
228 }
229
230 // ok, somewhere in the middle, fun
231 std::list<PacketBuffer*>::iterator i = responseQueue.begin();
232 std::list<PacketBuffer*>::iterator end = responseQueue.end();
233 std::list<PacketBuffer*>::iterator begin = responseQueue.begin();
234 bool done = false;
235
236 while (i != end && !done) {
237 if (readyTime < (*i)->ready) {
238 if (i == begin)
239 bridge->reschedule(sendEvent, readyTime);
240 responseQueue.insert(i,buf);
241 done = true;
242 }
243 i++;
244 }
245 assert(done);
246}
247
248void
249Bridge::BridgeMasterPort::queueForSendTiming(PacketPtr pkt)
250{
251 Tick readyTime = curTick() + delay;
252 PacketBuffer *buf = new PacketBuffer(pkt, readyTime);
253
254 // If we're about to put this packet at the head of the queue, we
255 // need to schedule an event to do the transmit. Otherwise there
256 // should already be an event scheduled for sending the head
257 // packet.
258 if (requestQueue.empty()) {
259 bridge->schedule(sendEvent, readyTime);
260 }
261
262 assert(requestQueue.size() != reqQueueLimit);
263
264 requestQueue.push_back(buf);
265}
266
267
268void
269Bridge::BridgeSlavePort::queueForSendTiming(PacketPtr pkt)
270{
271 // This is a response for a request we forwarded earlier. The
272 // corresponding PacketBuffer should be stored in the packet's
273 // senderState field.
274 PacketBuffer *buf = dynamic_cast<PacketBuffer*>(pkt->senderState);
275 assert(buf != NULL);
276 // set up new packet dest & senderState based on values saved
277 // from original request
278 buf->fixResponse(pkt);
279
280 DPRINTF(BusBridge, "response, new dest %d\n", pkt->getDest());
281 delete buf;
282
283 Tick readyTime = curTick() + delay;
284 buf = new PacketBuffer(pkt, readyTime);
285
286 // If we're about to put this packet at the head of the queue, we
287 // need to schedule an event to do the transmit. Otherwise there
288 // should already be an event scheduled for sending the head
289 // packet.
290 if (responseQueue.empty()) {
291 bridge->schedule(sendEvent, readyTime);
292 }
293 responseQueue.push_back(buf);
294}
295
296void
297Bridge::BridgeMasterPort::trySend()
298{
299 assert(!requestQueue.empty());
300
301 PacketBuffer *buf = requestQueue.front();
302
303 assert(buf->ready <= curTick());
304
305 PacketPtr pkt = buf->pkt;
306
307 DPRINTF(BusBridge, "trySend: origSrc %d dest %d addr 0x%x\n",
308 buf->origSrc, pkt->getDest(), pkt->getAddr());
309
310 // If the send was successful, make sure sender state was set to NULL
311 // otherwise we could get a NACK back of a packet that didn't expect a
312 // response and we would try to use freed memory.
313
314 Packet::SenderState *old_sender_state = pkt->senderState;
315 if (!buf->expectResponse)
316 pkt->senderState = NULL;
317
318 if (sendTiming(pkt)) {
319 // send successful
320 requestQueue.pop_front();
321 // we no longer own packet, so it's not safe to look at it
322 buf->pkt = NULL;
323
324 if (!buf->expectResponse) {
325 // no response expected... deallocate packet buffer now.
326 DPRINTF(BusBridge, " successful: no response expected\n");
327 delete buf;
328 }
329
330 // If there are more packets to send, schedule event to try again.
331 if (!requestQueue.empty()) {
332 buf = requestQueue.front();
333 DPRINTF(BusBridge, "Scheduling next send\n");
334 bridge->schedule(sendEvent, std::max(buf->ready, curTick() + 1));
335 }
336 } else {
337 DPRINTF(BusBridge, " unsuccessful\n");
338 pkt->senderState = old_sender_state;
339 inRetry = true;
340 }
341
342 DPRINTF(BusBridge, "trySend: request queue size: %d\n",
343 requestQueue.size());
344}
345
346void
347Bridge::BridgeSlavePort::trySend()
348{
349 assert(!responseQueue.empty());
350
351 PacketBuffer *buf = responseQueue.front();
352
353 assert(buf->ready <= curTick());
354
355 PacketPtr pkt = buf->pkt;
356
357 DPRINTF(BusBridge, "trySend: origSrc %d dest %d addr 0x%x\n",
358 buf->origSrc, pkt->getDest(), pkt->getAddr());
359
360 bool was_nacked_here = buf->nackedHere;
361
362 // no need to worry about the sender state since we are not
363 // modifying it
364
365 if (sendTiming(pkt)) {
366 DPRINTF(BusBridge, " successful\n");
367 // send successful
368 responseQueue.pop_front();
369 // this is a response... deallocate packet buffer now.
370 delete buf;
371
372 if (!was_nacked_here) {
373 assert(outstandingResponses != 0);
374 --outstandingResponses;
375 }
376
377 // If there are more packets to send, schedule event to try again.
378 if (!responseQueue.empty()) {
379 buf = responseQueue.front();
380 DPRINTF(BusBridge, "Scheduling next send\n");
381 bridge->schedule(sendEvent, std::max(buf->ready, curTick() + 1));
382 }
383 } else {
384 DPRINTF(BusBridge, " unsuccessful\n");
385 inRetry = true;
386 }
387
388 DPRINTF(BusBridge, "trySend: queue size: %d outstanding resp: %d\n",
389 responseQueue.size(), outstandingResponses);
390}
391
392void
393Bridge::BridgeMasterPort::recvRetry()
394{
395 inRetry = false;
396 Tick nextReady = requestQueue.front()->ready;
397 if (nextReady <= curTick())
398 trySend();
399 else
400 bridge->schedule(sendEvent, nextReady);
401}
402
403void
404Bridge::BridgeSlavePort::recvRetry()
405{
406 inRetry = false;
407 Tick nextReady = responseQueue.front()->ready;
408 if (nextReady <= curTick())
409 trySend();
410 else
411 bridge->schedule(sendEvent, nextReady);
412}
413
414Tick
415Bridge::BridgeMasterPort::recvAtomic(PacketPtr pkt)
416{
417 // master port should never receive any atomic access (panic only
418 // works once the other side, i.e. the busses, respects this)
419 //
420 //panic("Master port on %s got a recvAtomic\n", bridge->name());
421 return 0;
422}
423
424Tick
425Bridge::BridgeSlavePort::recvAtomic(PacketPtr pkt)
426{
427 return delay + masterPort.sendAtomic(pkt);
428}
429
430void
415Bridge::BridgeSlavePort::recvAtomic(PacketPtr pkt)
416{
417 return delay + masterPort.sendAtomic(pkt);
418}
419
420void
431Bridge::BridgeMasterPort::recvFunctional(PacketPtr pkt)
432{
433 // master port should never receive any functional access (panic
434 // only works once the other side, i.e. the busses, respect this)
435
436 // panic("Master port on %s got a recvFunctional\n", bridge->name());
437}
438
439void
440Bridge::BridgeSlavePort::recvFunctional(PacketPtr pkt)
441{
442 std::list<PacketBuffer*>::iterator i;
443
444 pkt->pushLabel(name());
445
446 // check the response queue
447 for (i = responseQueue.begin(); i != responseQueue.end(); ++i) {
448 if (pkt->checkFunctional((*i)->pkt)) {
449 pkt->makeResponse();
450 return;
451 }
452 }
453
454 // also check the master port's request queue
455 if (masterPort.checkFunctional(pkt)) {
456 return;
457 }
458
459 pkt->popLabel();
460
461 // fall through if pkt still not satisfied
462 masterPort.sendFunctional(pkt);
463}
464
465bool
466Bridge::BridgeMasterPort::checkFunctional(PacketPtr pkt)
467{
468 bool found = false;
469 std::list<PacketBuffer*>::iterator i = requestQueue.begin();
470
471 while(i != requestQueue.end() && !found) {
472 if (pkt->checkFunctional((*i)->pkt)) {
473 pkt->makeResponse();
474 found = true;
475 }
476 ++i;
477 }
478
479 return found;
480}
481
482AddrRangeList
483Bridge::BridgeSlavePort::getAddrRanges()
484{
485 return ranges;
486}
487
488Bridge *
489BridgeParams::create()
490{
491 return new Bridge(this);
492}
421Bridge::BridgeSlavePort::recvFunctional(PacketPtr pkt)
422{
423 std::list<PacketBuffer*>::iterator i;
424
425 pkt->pushLabel(name());
426
427 // check the response queue
428 for (i = responseQueue.begin(); i != responseQueue.end(); ++i) {
429 if (pkt->checkFunctional((*i)->pkt)) {
430 pkt->makeResponse();
431 return;
432 }
433 }
434
435 // also check the master port's request queue
436 if (masterPort.checkFunctional(pkt)) {
437 return;
438 }
439
440 pkt->popLabel();
441
442 // fall through if pkt still not satisfied
443 masterPort.sendFunctional(pkt);
444}
445
446bool
447Bridge::BridgeMasterPort::checkFunctional(PacketPtr pkt)
448{
449 bool found = false;
450 std::list<PacketBuffer*>::iterator i = requestQueue.begin();
451
452 while(i != requestQueue.end() && !found) {
453 if (pkt->checkFunctional((*i)->pkt)) {
454 pkt->makeResponse();
455 found = true;
456 }
457 ++i;
458 }
459
460 return found;
461}
462
463AddrRangeList
464Bridge::BridgeSlavePort::getAddrRanges()
465{
466 return ranges;
467}
468
469Bridge *
470BridgeParams::create()
471{
472 return new Bridge(this);
473}