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),
| 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),
|
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::recvTimingResp(PacketPtr pkt) 141{ 142 // all checks are done when the request is accepted on the slave 143 // side, so we are guaranteed to have space for the response 144 DPRINTF(BusBridge, "recvTiming: response %s addr 0x%x\n", 145 pkt->cmdString(), pkt->getAddr()); 146 147 DPRINTF(BusBridge, "Request queue size: %d\n", requestQueue.size()); 148 149 slavePort.queueForSendTiming(pkt); 150 151 return true; 152} 153 154bool 155Bridge::BridgeSlavePort::recvTimingReq(PacketPtr pkt) 156{ 157 DPRINTF(BusBridge, "recvTiming: request %s addr 0x%x\n", 158 pkt->cmdString(), pkt->getAddr()); 159 160 DPRINTF(BusBridge, "Response queue size: %d outresp: %d\n", 161 responseQueue.size(), outstandingResponses); 162 163 if (masterPort.reqQueueFull()) { 164 DPRINTF(BusBridge, "Request queue full, nacking\n"); 165 nackRequest(pkt); 166 return true; 167 } 168 169 if (pkt->needsResponse()) { 170 if (respQueueFull()) { 171 DPRINTF(BusBridge, 172 "Response queue full, no space for response, nacking\n"); 173 DPRINTF(BusBridge, 174 "queue size: %d outstanding resp: %d\n", 175 responseQueue.size(), outstandingResponses); 176 nackRequest(pkt); 177 return true; 178 } else { 179 DPRINTF(BusBridge, "Request Needs response, reserving space\n"); 180 assert(outstandingResponses != respQueueLimit); 181 ++outstandingResponses; 182 } 183 } 184 185 masterPort.queueForSendTiming(pkt); 186 187 return true; 188} 189 190void 191Bridge::BridgeSlavePort::nackRequest(PacketPtr pkt) 192{ 193 // Nack the packet 194 pkt->makeTimingResponse(); 195 pkt->setNacked(); 196 197 // The Nack packets are stored in the response queue just like any 198 // other response, but they do not occupy any space as this is 199 // tracked by the outstandingResponses, this guarantees space for 200 // the Nack packets, but implicitly means we have an (unrealistic) 201 // unbounded Nack queue. 202 203 // put it on the list to send 204 Tick readyTime = curTick() + nackDelay; 205 DeferredResponse resp(pkt, readyTime, true); 206 207 // nothing on the list, add it and we're done 208 if (responseQueue.empty()) { 209 assert(!sendEvent.scheduled()); 210 bridge->schedule(sendEvent, readyTime); 211 responseQueue.push_back(resp); 212 return; 213 } 214 215 assert(sendEvent.scheduled() || inRetry); 216 217 // does it go at the end? 218 if (readyTime >= responseQueue.back().ready) { 219 responseQueue.push_back(resp); 220 return; 221 } 222 223 // ok, somewhere in the middle, fun 224 std::list<DeferredResponse>::iterator i = responseQueue.begin(); 225 std::list<DeferredResponse>::iterator end = responseQueue.end(); 226 std::list<DeferredResponse>::iterator begin = responseQueue.begin(); 227 bool done = false; 228 229 while (i != end && !done) { 230 if (readyTime < (*i).ready) { 231 if (i == begin) 232 bridge->reschedule(sendEvent, readyTime); 233 responseQueue.insert(i, resp); 234 done = true; 235 } 236 i++; 237 } 238 assert(done); 239} 240 241void 242Bridge::BridgeMasterPort::queueForSendTiming(PacketPtr pkt) 243{ 244 Tick readyTime = curTick() + delay; 245 246 // If we expect to see a response, we need to restore the source 247 // and destination field that is potentially changed by a second 248 // bus 249 if (!pkt->memInhibitAsserted() && pkt->needsResponse()) { 250 // Update the sender state so we can deal with the response 251 // appropriately 252 RequestState *req_state = new RequestState(pkt); 253 pkt->senderState = req_state; 254 } 255 256 // If we're about to put this packet at the head of the queue, we 257 // need to schedule an event to do the transmit. Otherwise there 258 // should already be an event scheduled for sending the head 259 // packet. 260 if (requestQueue.empty()) { 261 bridge->schedule(sendEvent, readyTime); 262 } 263 264 assert(requestQueue.size() != reqQueueLimit); 265 266 requestQueue.push_back(DeferredRequest(pkt, readyTime)); 267} 268 269 270void 271Bridge::BridgeSlavePort::queueForSendTiming(PacketPtr pkt) 272{ 273 // This is a response for a request we forwarded earlier. The 274 // corresponding request state should be stored in the packet's 275 // senderState field. 276 RequestState *req_state = dynamic_cast<RequestState*>(pkt->senderState); 277 assert(req_state != NULL); 278 // set up new packet dest & senderState based on values saved 279 // from original request 280 req_state->fixResponse(pkt); 281 282 // the bridge assumes that at least one bus has set the 283 // destination field of the packet 284 assert(pkt->isDestValid()); 285 DPRINTF(BusBridge, "response, new dest %d\n", pkt->getDest()); 286 delete req_state; 287 288 Tick readyTime = curTick() + delay; 289 290 // If we're about to put this packet at the head of the queue, we 291 // need to schedule an event to do the transmit. Otherwise there 292 // should already be an event scheduled for sending the head 293 // packet. 294 if (responseQueue.empty()) { 295 bridge->schedule(sendEvent, readyTime); 296 } 297 responseQueue.push_back(DeferredResponse(pkt, readyTime)); 298} 299 300void 301Bridge::BridgeMasterPort::trySend() 302{ 303 assert(!requestQueue.empty()); 304 305 DeferredRequest req = requestQueue.front(); 306 307 assert(req.ready <= curTick()); 308 309 PacketPtr pkt = req.pkt; 310 311 DPRINTF(BusBridge, "trySend request: addr 0x%x\n", pkt->getAddr()); 312 313 if (sendTimingReq(pkt)) { 314 // send successful 315 requestQueue.pop_front(); 316 317 // If there are more packets to send, schedule event to try again. 318 if (!requestQueue.empty()) { 319 req = requestQueue.front(); 320 DPRINTF(BusBridge, "Scheduling next send\n"); 321 bridge->schedule(sendEvent, 322 std::max(req.ready, curTick() + 1)); 323 } 324 } else { 325 inRetry = true; 326 } 327 328 DPRINTF(BusBridge, "trySend: request queue size: %d\n", 329 requestQueue.size()); 330} 331 332void 333Bridge::BridgeSlavePort::trySend() 334{ 335 assert(!responseQueue.empty()); 336 337 DeferredResponse resp = responseQueue.front(); 338 339 assert(resp.ready <= curTick()); 340 341 PacketPtr pkt = resp.pkt; 342 343 DPRINTF(BusBridge, "trySend response: dest %d addr 0x%x\n", 344 pkt->getDest(), pkt->getAddr()); 345 346 bool was_nacked_here = resp.nackedHere; 347 348 if (sendTimingResp(pkt)) { 349 DPRINTF(BusBridge, " successful\n"); 350 // send successful 351 responseQueue.pop_front(); 352 353 if (!was_nacked_here) { 354 assert(outstandingResponses != 0); 355 --outstandingResponses; 356 } 357 358 // If there are more packets to send, schedule event to try again. 359 if (!responseQueue.empty()) { 360 resp = responseQueue.front(); 361 DPRINTF(BusBridge, "Scheduling next send\n"); 362 bridge->schedule(sendEvent, 363 std::max(resp.ready, curTick() + 1)); 364 } 365 } else { 366 DPRINTF(BusBridge, " unsuccessful\n"); 367 inRetry = true; 368 } 369 370 DPRINTF(BusBridge, "trySend: queue size: %d outstanding resp: %d\n", 371 responseQueue.size(), outstandingResponses); 372} 373 374void 375Bridge::BridgeMasterPort::recvRetry() 376{ 377 inRetry = false; 378 Tick nextReady = requestQueue.front().ready; 379 if (nextReady <= curTick()) 380 trySend(); 381 else 382 bridge->schedule(sendEvent, nextReady); 383} 384 385void 386Bridge::BridgeSlavePort::recvRetry() 387{ 388 inRetry = false; 389 Tick nextReady = responseQueue.front().ready; 390 if (nextReady <= curTick()) 391 trySend(); 392 else 393 bridge->schedule(sendEvent, nextReady); 394} 395 396Tick 397Bridge::BridgeSlavePort::recvAtomic(PacketPtr pkt) 398{ 399 return delay + masterPort.sendAtomic(pkt); 400} 401 402void 403Bridge::BridgeSlavePort::recvFunctional(PacketPtr pkt) 404{ 405 std::list<DeferredResponse>::iterator i; 406 407 pkt->pushLabel(name()); 408 409 // check the response queue 410 for (i = responseQueue.begin(); i != responseQueue.end(); ++i) { 411 if (pkt->checkFunctional((*i).pkt)) { 412 pkt->makeResponse(); 413 return; 414 } 415 } 416 417 // also check the master port's request queue 418 if (masterPort.checkFunctional(pkt)) { 419 return; 420 } 421 422 pkt->popLabel(); 423 424 // fall through if pkt still not satisfied 425 masterPort.sendFunctional(pkt); 426} 427 428bool 429Bridge::BridgeMasterPort::checkFunctional(PacketPtr pkt) 430{ 431 bool found = false; 432 std::list<DeferredRequest>::iterator i = requestQueue.begin(); 433 434 while(i != requestQueue.end() && !found) { 435 if (pkt->checkFunctional((*i).pkt)) { 436 pkt->makeResponse(); 437 found = true; 438 } 439 ++i; 440 } 441 442 return found; 443} 444 445AddrRangeList 446Bridge::BridgeSlavePort::getAddrRanges() const 447{ 448 return ranges; 449} 450 451Bridge * 452BridgeParams::create() 453{ 454 return new Bridge(this); 455}
| 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::recvTimingResp(PacketPtr pkt) 141{ 142 // all checks are done when the request is accepted on the slave 143 // side, so we are guaranteed to have space for the response 144 DPRINTF(BusBridge, "recvTiming: response %s addr 0x%x\n", 145 pkt->cmdString(), pkt->getAddr()); 146 147 DPRINTF(BusBridge, "Request queue size: %d\n", requestQueue.size()); 148 149 slavePort.queueForSendTiming(pkt); 150 151 return true; 152} 153 154bool 155Bridge::BridgeSlavePort::recvTimingReq(PacketPtr pkt) 156{ 157 DPRINTF(BusBridge, "recvTiming: request %s addr 0x%x\n", 158 pkt->cmdString(), pkt->getAddr()); 159 160 DPRINTF(BusBridge, "Response queue size: %d outresp: %d\n", 161 responseQueue.size(), outstandingResponses); 162 163 if (masterPort.reqQueueFull()) { 164 DPRINTF(BusBridge, "Request queue full, nacking\n"); 165 nackRequest(pkt); 166 return true; 167 } 168 169 if (pkt->needsResponse()) { 170 if (respQueueFull()) { 171 DPRINTF(BusBridge, 172 "Response queue full, no space for response, nacking\n"); 173 DPRINTF(BusBridge, 174 "queue size: %d outstanding resp: %d\n", 175 responseQueue.size(), outstandingResponses); 176 nackRequest(pkt); 177 return true; 178 } else { 179 DPRINTF(BusBridge, "Request Needs response, reserving space\n"); 180 assert(outstandingResponses != respQueueLimit); 181 ++outstandingResponses; 182 } 183 } 184 185 masterPort.queueForSendTiming(pkt); 186 187 return true; 188} 189 190void 191Bridge::BridgeSlavePort::nackRequest(PacketPtr pkt) 192{ 193 // Nack the packet 194 pkt->makeTimingResponse(); 195 pkt->setNacked(); 196 197 // The Nack packets are stored in the response queue just like any 198 // other response, but they do not occupy any space as this is 199 // tracked by the outstandingResponses, this guarantees space for 200 // the Nack packets, but implicitly means we have an (unrealistic) 201 // unbounded Nack queue. 202 203 // put it on the list to send 204 Tick readyTime = curTick() + nackDelay; 205 DeferredResponse resp(pkt, readyTime, true); 206 207 // nothing on the list, add it and we're done 208 if (responseQueue.empty()) { 209 assert(!sendEvent.scheduled()); 210 bridge->schedule(sendEvent, readyTime); 211 responseQueue.push_back(resp); 212 return; 213 } 214 215 assert(sendEvent.scheduled() || inRetry); 216 217 // does it go at the end? 218 if (readyTime >= responseQueue.back().ready) { 219 responseQueue.push_back(resp); 220 return; 221 } 222 223 // ok, somewhere in the middle, fun 224 std::list<DeferredResponse>::iterator i = responseQueue.begin(); 225 std::list<DeferredResponse>::iterator end = responseQueue.end(); 226 std::list<DeferredResponse>::iterator begin = responseQueue.begin(); 227 bool done = false; 228 229 while (i != end && !done) { 230 if (readyTime < (*i).ready) { 231 if (i == begin) 232 bridge->reschedule(sendEvent, readyTime); 233 responseQueue.insert(i, resp); 234 done = true; 235 } 236 i++; 237 } 238 assert(done); 239} 240 241void 242Bridge::BridgeMasterPort::queueForSendTiming(PacketPtr pkt) 243{ 244 Tick readyTime = curTick() + delay; 245 246 // If we expect to see a response, we need to restore the source 247 // and destination field that is potentially changed by a second 248 // bus 249 if (!pkt->memInhibitAsserted() && pkt->needsResponse()) { 250 // Update the sender state so we can deal with the response 251 // appropriately 252 RequestState *req_state = new RequestState(pkt); 253 pkt->senderState = req_state; 254 } 255 256 // If we're about to put this packet at the head of the queue, we 257 // need to schedule an event to do the transmit. Otherwise there 258 // should already be an event scheduled for sending the head 259 // packet. 260 if (requestQueue.empty()) { 261 bridge->schedule(sendEvent, readyTime); 262 } 263 264 assert(requestQueue.size() != reqQueueLimit); 265 266 requestQueue.push_back(DeferredRequest(pkt, readyTime)); 267} 268 269 270void 271Bridge::BridgeSlavePort::queueForSendTiming(PacketPtr pkt) 272{ 273 // This is a response for a request we forwarded earlier. The 274 // corresponding request state should be stored in the packet's 275 // senderState field. 276 RequestState *req_state = dynamic_cast<RequestState*>(pkt->senderState); 277 assert(req_state != NULL); 278 // set up new packet dest & senderState based on values saved 279 // from original request 280 req_state->fixResponse(pkt); 281 282 // the bridge assumes that at least one bus has set the 283 // destination field of the packet 284 assert(pkt->isDestValid()); 285 DPRINTF(BusBridge, "response, new dest %d\n", pkt->getDest()); 286 delete req_state; 287 288 Tick readyTime = curTick() + delay; 289 290 // If we're about to put this packet at the head of the queue, we 291 // need to schedule an event to do the transmit. Otherwise there 292 // should already be an event scheduled for sending the head 293 // packet. 294 if (responseQueue.empty()) { 295 bridge->schedule(sendEvent, readyTime); 296 } 297 responseQueue.push_back(DeferredResponse(pkt, readyTime)); 298} 299 300void 301Bridge::BridgeMasterPort::trySend() 302{ 303 assert(!requestQueue.empty()); 304 305 DeferredRequest req = requestQueue.front(); 306 307 assert(req.ready <= curTick()); 308 309 PacketPtr pkt = req.pkt; 310 311 DPRINTF(BusBridge, "trySend request: addr 0x%x\n", pkt->getAddr()); 312 313 if (sendTimingReq(pkt)) { 314 // send successful 315 requestQueue.pop_front(); 316 317 // If there are more packets to send, schedule event to try again. 318 if (!requestQueue.empty()) { 319 req = requestQueue.front(); 320 DPRINTF(BusBridge, "Scheduling next send\n"); 321 bridge->schedule(sendEvent, 322 std::max(req.ready, curTick() + 1)); 323 } 324 } else { 325 inRetry = true; 326 } 327 328 DPRINTF(BusBridge, "trySend: request queue size: %d\n", 329 requestQueue.size()); 330} 331 332void 333Bridge::BridgeSlavePort::trySend() 334{ 335 assert(!responseQueue.empty()); 336 337 DeferredResponse resp = responseQueue.front(); 338 339 assert(resp.ready <= curTick()); 340 341 PacketPtr pkt = resp.pkt; 342 343 DPRINTF(BusBridge, "trySend response: dest %d addr 0x%x\n", 344 pkt->getDest(), pkt->getAddr()); 345 346 bool was_nacked_here = resp.nackedHere; 347 348 if (sendTimingResp(pkt)) { 349 DPRINTF(BusBridge, " successful\n"); 350 // send successful 351 responseQueue.pop_front(); 352 353 if (!was_nacked_here) { 354 assert(outstandingResponses != 0); 355 --outstandingResponses; 356 } 357 358 // If there are more packets to send, schedule event to try again. 359 if (!responseQueue.empty()) { 360 resp = responseQueue.front(); 361 DPRINTF(BusBridge, "Scheduling next send\n"); 362 bridge->schedule(sendEvent, 363 std::max(resp.ready, curTick() + 1)); 364 } 365 } else { 366 DPRINTF(BusBridge, " unsuccessful\n"); 367 inRetry = true; 368 } 369 370 DPRINTF(BusBridge, "trySend: queue size: %d outstanding resp: %d\n", 371 responseQueue.size(), outstandingResponses); 372} 373 374void 375Bridge::BridgeMasterPort::recvRetry() 376{ 377 inRetry = false; 378 Tick nextReady = requestQueue.front().ready; 379 if (nextReady <= curTick()) 380 trySend(); 381 else 382 bridge->schedule(sendEvent, nextReady); 383} 384 385void 386Bridge::BridgeSlavePort::recvRetry() 387{ 388 inRetry = false; 389 Tick nextReady = responseQueue.front().ready; 390 if (nextReady <= curTick()) 391 trySend(); 392 else 393 bridge->schedule(sendEvent, nextReady); 394} 395 396Tick 397Bridge::BridgeSlavePort::recvAtomic(PacketPtr pkt) 398{ 399 return delay + masterPort.sendAtomic(pkt); 400} 401 402void 403Bridge::BridgeSlavePort::recvFunctional(PacketPtr pkt) 404{ 405 std::list<DeferredResponse>::iterator i; 406 407 pkt->pushLabel(name()); 408 409 // check the response queue 410 for (i = responseQueue.begin(); i != responseQueue.end(); ++i) { 411 if (pkt->checkFunctional((*i).pkt)) { 412 pkt->makeResponse(); 413 return; 414 } 415 } 416 417 // also check the master port's request queue 418 if (masterPort.checkFunctional(pkt)) { 419 return; 420 } 421 422 pkt->popLabel(); 423 424 // fall through if pkt still not satisfied 425 masterPort.sendFunctional(pkt); 426} 427 428bool 429Bridge::BridgeMasterPort::checkFunctional(PacketPtr pkt) 430{ 431 bool found = false; 432 std::list<DeferredRequest>::iterator i = requestQueue.begin(); 433 434 while(i != requestQueue.end() && !found) { 435 if (pkt->checkFunctional((*i).pkt)) { 436 pkt->makeResponse(); 437 found = true; 438 } 439 ++i; 440 } 441 442 return found; 443} 444 445AddrRangeList 446Bridge::BridgeSlavePort::getAddrRanges() const 447{ 448 return ranges; 449} 450 451Bridge * 452BridgeParams::create() 453{ 454 return new Bridge(this); 455}
|