coherent_xbar.cc revision 9032
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 * Andreas Hansson 42 * William Wang 43 */ 44 45/** 46 * @file 47 * Definition of a bus object. 48 */ 49 50#include "base/misc.hh" 51#include "base/trace.hh" 52#include "debug/Bus.hh" 53#include "debug/BusAddrRanges.hh" 54#include "mem/bus.hh" 55 56Bus::Bus(const BusParams *p) 57 : MemObject(p), clock(p->clock), 58 headerCycles(p->header_cycles), width(p->width), tickNextIdle(0), 59 drainEvent(NULL), busIdleEvent(this), inRetry(false), 60 defaultPortID(InvalidPortID), 61 useDefaultRange(p->use_default_range), 62 defaultBlockSize(p->block_size), 63 cachedBlockSize(0), cachedBlockSizeValid(false) 64{ 65 //width, clock period, and header cycles must be positive 66 if (width <= 0) 67 fatal("Bus width must be positive\n"); 68 if (clock <= 0) 69 fatal("Bus clock period must be positive\n"); 70 if (headerCycles <= 0) 71 fatal("Number of header cycles must be positive\n"); 72 73 // create the ports based on the size of the master and slave 74 // vector ports, and the presence of the default port, the ports 75 // are enumerated starting from zero 76 for (int i = 0; i < p->port_master_connection_count; ++i) { 77 std::string portName = csprintf("%s-p%d", name(), i); 78 MasterPort* bp = new BusMasterPort(portName, this, i); 79 masterPorts.push_back(bp); 80 } 81 82 // see if we have a default slave device connected and if so add 83 // our corresponding master port 84 if (p->port_default_connection_count) { 85 defaultPortID = masterPorts.size(); 86 std::string portName = csprintf("%s-default", name()); 87 MasterPort* bp = new BusMasterPort(portName, this, defaultPortID); 88 masterPorts.push_back(bp); 89 } 90 91 // create the slave ports, once again starting at zero 92 for (int i = 0; i < p->port_slave_connection_count; ++i) { 93 std::string portName = csprintf("%s-p%d", name(), i); 94 SlavePort* bp = new BusSlavePort(portName, this, i); 95 slavePorts.push_back(bp); 96 } 97 98 clearPortCache(); 99} 100 101MasterPort & 102Bus::getMasterPort(const std::string &if_name, int idx) 103{ 104 if (if_name == "master" && idx < masterPorts.size()) { 105 // the master port index translates directly to the vector position 106 return *masterPorts[idx]; 107 } else if (if_name == "default") { 108 return *masterPorts[defaultPortID]; 109 } else { 110 return MemObject::getMasterPort(if_name, idx); 111 } 112} 113 114SlavePort & 115Bus::getSlavePort(const std::string &if_name, int idx) 116{ 117 if (if_name == "slave" && idx < slavePorts.size()) { 118 // the slave port index translates directly to the vector position 119 return *slavePorts[idx]; 120 } else { 121 return MemObject::getSlavePort(if_name, idx); 122 } 123} 124 125void 126Bus::init() 127{ 128 // iterate over our slave ports and determine which of our 129 // neighbouring master ports are snooping and add them as snoopers 130 for (SlavePortConstIter p = slavePorts.begin(); p != slavePorts.end(); 131 ++p) { 132 if ((*p)->getMasterPort().isSnooping()) { 133 DPRINTF(BusAddrRanges, "Adding snooping neighbour %s\n", 134 (*p)->getMasterPort().name()); 135 snoopPorts.push_back(*p); 136 } 137 } 138} 139 140Tick 141Bus::calcPacketTiming(PacketPtr pkt) 142{ 143 // determine the current time rounded to the closest following 144 // clock edge 145 Tick now = curTick(); 146 if (now % clock != 0) { 147 now = ((now / clock) + 1) * clock; 148 } 149 150 Tick headerTime = now + headerCycles * clock; 151 152 // The packet will be sent. Figure out how long it occupies the bus, and 153 // how much of that time is for the first "word", aka bus width. 154 int numCycles = 0; 155 if (pkt->hasData()) { 156 // If a packet has data, it needs ceil(size/width) cycles to send it 157 int dataSize = pkt->getSize(); 158 numCycles += dataSize/width; 159 if (dataSize % width) 160 numCycles++; 161 } 162 163 // The first word will be delivered after the current tick, the delivery 164 // of the address if any, and one bus cycle to deliver the data 165 pkt->firstWordTime = headerTime + clock; 166 167 pkt->finishTime = headerTime + numCycles * clock; 168 169 return headerTime; 170} 171 172void Bus::occupyBus(Tick until) 173{ 174 if (until == 0) { 175 // shortcut for express snoop packets 176 return; 177 } 178 179 tickNextIdle = until; 180 reschedule(busIdleEvent, tickNextIdle, true); 181 182 DPRINTF(Bus, "The bus is now occupied from tick %d to %d\n", 183 curTick(), tickNextIdle); 184} 185 186bool 187Bus::isOccupied(PacketPtr pkt, Port* port) 188{ 189 // first we see if the next idle tick is in the future, next the 190 // bus is considered occupied if there are ports on the retry list 191 // and we are not in a retry with the current port 192 if (tickNextIdle > curTick() || 193 (!retryList.empty() && !(inRetry && port == retryList.front()))) { 194 addToRetryList(port); 195 return true; 196 } 197 return false; 198} 199 200bool 201Bus::recvTimingReq(PacketPtr pkt, PortID slave_port_id) 202{ 203 // determine the source port based on the id 204 SlavePort *src_port = slavePorts[slave_port_id]; 205 206 // test if the bus should be considered occupied for the current 207 // packet, and exclude express snoops from the check 208 if (!pkt->isExpressSnoop() && isOccupied(pkt, src_port)) { 209 DPRINTF(Bus, "recvTimingReq: src %s %s 0x%x BUSY\n", 210 src_port->name(), pkt->cmdString(), pkt->getAddr()); 211 return false; 212 } 213 214 DPRINTF(Bus, "recvTimingReq: src %s %s 0x%x\n", 215 src_port->name(), pkt->cmdString(), pkt->getAddr()); 216 217 // set the source port for routing of the response 218 pkt->setSrc(slave_port_id); 219 220 Tick headerFinishTime = pkt->isExpressSnoop() ? 0 : calcPacketTiming(pkt); 221 Tick packetFinishTime = pkt->isExpressSnoop() ? 0 : pkt->finishTime; 222 223 // uncacheable requests need never be snooped 224 if (!pkt->req->isUncacheable()) { 225 // the packet is a memory-mapped request and should be 226 // broadcasted to our snoopers but the source 227 forwardTiming(pkt, slave_port_id); 228 } 229 230 // remember if we add an outstanding req so we can undo it if 231 // necessary, if the packet needs a response, we should add it 232 // as outstanding and express snoops never fail so there is 233 // not need to worry about them 234 bool add_outstanding = !pkt->isExpressSnoop() && pkt->needsResponse(); 235 236 // keep track that we have an outstanding request packet 237 // matching this request, this is used by the coherency 238 // mechanism in determining what to do with snoop responses 239 // (in recvTimingSnoop) 240 if (add_outstanding) { 241 // we should never have an exsiting request outstanding 242 assert(outstandingReq.find(pkt->req) == outstandingReq.end()); 243 outstandingReq.insert(pkt->req); 244 } 245 246 // since it is a normal request, determine the destination 247 // based on the address and attempt to send the packet 248 bool success = masterPorts[findPort(pkt->getAddr())]->sendTimingReq(pkt); 249 250 if (!success) { 251 // inhibited packets should never be forced to retry 252 assert(!pkt->memInhibitAsserted()); 253 254 // if it was added as outstanding and the send failed, then 255 // erase it again 256 if (add_outstanding) 257 outstandingReq.erase(pkt->req); 258 259 DPRINTF(Bus, "recvTimingReq: src %s %s 0x%x RETRY\n", 260 src_port->name(), pkt->cmdString(), pkt->getAddr()); 261 262 addToRetryList(src_port); 263 occupyBus(headerFinishTime); 264 265 return false; 266 } 267 268 succeededTiming(packetFinishTime); 269 270 return true; 271} 272 273bool 274Bus::recvTimingResp(PacketPtr pkt, PortID master_port_id) 275{ 276 // determine the source port based on the id 277 MasterPort *src_port = masterPorts[master_port_id]; 278 279 // test if the bus should be considered occupied for the current 280 // packet 281 if (isOccupied(pkt, src_port)) { 282 DPRINTF(Bus, "recvTimingResp: src %s %s 0x%x BUSY\n", 283 src_port->name(), pkt->cmdString(), pkt->getAddr()); 284 return false; 285 } 286 287 DPRINTF(Bus, "recvTimingResp: src %s %s 0x%x\n", 288 src_port->name(), pkt->cmdString(), pkt->getAddr()); 289 290 calcPacketTiming(pkt); 291 Tick packetFinishTime = pkt->finishTime; 292 293 // the packet is a normal response to a request that we should 294 // have seen passing through the bus 295 assert(outstandingReq.find(pkt->req) != outstandingReq.end()); 296 297 // remove it as outstanding 298 outstandingReq.erase(pkt->req); 299 300 // send the packet to the destination through one of our slave 301 // ports, as determined by the destination field 302 bool success M5_VAR_USED = slavePorts[pkt->getDest()]->sendTimingResp(pkt); 303 304 // currently it is illegal to block responses... can lead to 305 // deadlock 306 assert(success); 307 308 succeededTiming(packetFinishTime); 309 310 return true; 311} 312 313void 314Bus::recvTimingSnoopReq(PacketPtr pkt, PortID master_port_id) 315{ 316 DPRINTF(Bus, "recvTimingSnoopReq: src %s %s 0x%x\n", 317 masterPorts[master_port_id]->name(), pkt->cmdString(), 318 pkt->getAddr()); 319 320 // we should only see express snoops from caches 321 assert(pkt->isExpressSnoop()); 322 323 // set the source port for routing of the response 324 pkt->setSrc(master_port_id); 325 326 // forward to all snoopers 327 forwardTiming(pkt, InvalidPortID); 328 329 // a snoop request came from a connected slave device (one of 330 // our master ports), and if it is not coming from the slave 331 // device responsible for the address range something is 332 // wrong, hence there is nothing further to do as the packet 333 // would be going back to where it came from 334 assert(master_port_id == findPort(pkt->getAddr())); 335 336 // this is an express snoop and is never forced to retry 337 assert(!inRetry); 338} 339 340bool 341Bus::recvTimingSnoopResp(PacketPtr pkt, PortID slave_port_id) 342{ 343 // determine the source port based on the id 344 SlavePort* src_port = slavePorts[slave_port_id]; 345 346 if (isOccupied(pkt, src_port)) { 347 DPRINTF(Bus, "recvTimingSnoopResp: src %s %s 0x%x BUSY\n", 348 src_port->name(), pkt->cmdString(), pkt->getAddr()); 349 return false; 350 } 351 352 DPRINTF(Bus, "recvTimingSnoop: src %s %s 0x%x\n", 353 src_port->name(), pkt->cmdString(), pkt->getAddr()); 354 355 // get the destination from the packet 356 PortID dest = pkt->getDest(); 357 358 // responses are never express snoops 359 assert(!pkt->isExpressSnoop()); 360 361 calcPacketTiming(pkt); 362 Tick packetFinishTime = pkt->finishTime; 363 364 // determine if the response is from a snoop request we 365 // created as the result of a normal request (in which case it 366 // should be in the outstandingReq), or if we merely forwarded 367 // someone else's snoop request 368 if (outstandingReq.find(pkt->req) == outstandingReq.end()) { 369 // this is a snoop response to a snoop request we 370 // forwarded, e.g. coming from the L1 and going to the L2 371 // this should be forwarded as a snoop response 372 bool success M5_VAR_USED = masterPorts[dest]->sendTimingSnoopResp(pkt); 373 assert(success); 374 } else { 375 // we got a snoop response on one of our slave ports, 376 // i.e. from a coherent master connected to the bus, and 377 // since we created the snoop request as part of 378 // recvTiming, this should now be a normal response again 379 outstandingReq.erase(pkt->req); 380 381 // this is a snoop response from a coherent master, with a 382 // destination field set on its way through the bus as 383 // request, hence it should never go back to where the 384 // snoop response came from, but instead to where the 385 // original request came from 386 assert(slave_port_id != dest); 387 388 // as a normal response, it should go back to a master 389 // through one of our slave ports 390 bool success M5_VAR_USED = slavePorts[dest]->sendTimingResp(pkt); 391 392 // currently it is illegal to block responses... can lead 393 // to deadlock 394 assert(success); 395 } 396 397 succeededTiming(packetFinishTime); 398 399 return true; 400} 401 402 403void 404Bus::succeededTiming(Tick busy_time) 405{ 406 // occupy the bus accordingly 407 occupyBus(busy_time); 408 409 // if a retrying port succeeded, also take it off the retry list 410 if (inRetry) { 411 DPRINTF(Bus, "Remove retry from list %s\n", 412 retryList.front()->name()); 413 retryList.pop_front(); 414 inRetry = false; 415 } 416} 417 418void 419Bus::forwardTiming(PacketPtr pkt, PortID exclude_slave_port_id) 420{ 421 for (SlavePortIter s = snoopPorts.begin(); s != snoopPorts.end(); ++s) { 422 SlavePort *p = *s; 423 // we could have gotten this request from a snooping master 424 // (corresponding to our own slave port that is also in 425 // snoopPorts) and should not send it back to where it came 426 // from 427 if (exclude_slave_port_id == InvalidPortID || 428 p->getId() != exclude_slave_port_id) { 429 // cache is not allowed to refuse snoop 430 p->sendTimingSnoopReq(pkt); 431 } 432 } 433} 434 435void 436Bus::releaseBus() 437{ 438 // releasing the bus means we should now be idle 439 assert(curTick() >= tickNextIdle); 440 441 // bus is now idle, so if someone is waiting we can retry 442 if (!retryList.empty()) { 443 // note that we block (return false on recvTiming) both 444 // because the bus is busy and because the destination is 445 // busy, and in the latter case the bus may be released before 446 // we see a retry from the destination 447 retryWaiting(); 448 } 449 450 //If we weren't able to drain before, we might be able to now. 451 if (drainEvent && retryList.empty() && curTick() >= tickNextIdle) { 452 drainEvent->process(); 453 // Clear the drain event once we're done with it. 454 drainEvent = NULL; 455 } 456} 457 458void 459Bus::retryWaiting() 460{ 461 // this should never be called with an empty retry list 462 assert(!retryList.empty()); 463 464 // send a retry to the port at the head of the retry list 465 inRetry = true; 466 467 // note that we might have blocked on the receiving port being 468 // busy (rather than the bus itself) and now call retry before the 469 // destination called retry on the bus 470 retryList.front()->sendRetry(); 471 472 // If inRetry is still true, sendTiming wasn't called in zero time 473 // (e.g. the cache does this) 474 if (inRetry) { 475 retryList.pop_front(); 476 inRetry = false; 477 478 //Bring tickNextIdle up to the present 479 while (tickNextIdle < curTick()) 480 tickNextIdle += clock; 481 482 //Burn a cycle for the missed grant. 483 tickNextIdle += clock; 484 485 reschedule(busIdleEvent, tickNextIdle, true); 486 } 487} 488 489void 490Bus::recvRetry() 491{ 492 // we got a retry from a peer that we tried to send something to 493 // and failed, but we sent it on the account of someone else, and 494 // that source port should be on our retry list, however if the 495 // bus is released before this happens and the retry (from the bus 496 // point of view) is successful then this no longer holds and we 497 // could in fact have an empty retry list 498 if (retryList.empty()) 499 return; 500 501 // if the bus isn't busy 502 if (curTick() >= tickNextIdle) { 503 // note that we do not care who told us to retry at the moment, we 504 // merely let the first one on the retry list go 505 retryWaiting(); 506 } 507} 508 509PortID 510Bus::findPort(Addr addr) 511{ 512 /* An interval tree would be a better way to do this. --ali. */ 513 PortID dest_id = checkPortCache(addr); 514 if (dest_id != InvalidPortID) 515 return dest_id; 516 517 // Check normal port ranges 518 PortIter i = portMap.find(RangeSize(addr,1)); 519 if (i != portMap.end()) { 520 dest_id = i->second; 521 updatePortCache(dest_id, i->first.start, i->first.end); 522 return dest_id; 523 } 524 525 // Check if this matches the default range 526 if (useDefaultRange) { 527 AddrRangeIter a_end = defaultRange.end(); 528 for (AddrRangeIter i = defaultRange.begin(); i != a_end; i++) { 529 if (*i == addr) { 530 DPRINTF(Bus, " found addr %#llx on default\n", addr); 531 return defaultPortID; 532 } 533 } 534 } else if (defaultPortID != InvalidPortID) { 535 DPRINTF(Bus, "Unable to find destination for addr %#llx, " 536 "will use default port\n", addr); 537 return defaultPortID; 538 } 539 540 // we should use the range for the default port and it did not 541 // match, or the default port is not set 542 fatal("Unable to find destination for addr %#llx on bus %s\n", addr, 543 name()); 544} 545 546Tick 547Bus::recvAtomic(PacketPtr pkt, PortID slave_port_id) 548{ 549 DPRINTF(Bus, "recvAtomic: packet src %s addr 0x%x cmd %s\n", 550 slavePorts[slave_port_id]->name(), pkt->getAddr(), 551 pkt->cmdString()); 552 553 MemCmd snoop_response_cmd = MemCmd::InvalidCmd; 554 Tick snoop_response_latency = 0; 555 556 // uncacheable requests need never be snooped 557 if (!pkt->req->isUncacheable()) { 558 // forward to all snoopers but the source 559 std::pair<MemCmd, Tick> snoop_result = 560 forwardAtomic(pkt, slave_port_id); 561 snoop_response_cmd = snoop_result.first; 562 snoop_response_latency = snoop_result.second; 563 } 564 565 // even if we had a snoop response, we must continue and also 566 // perform the actual request at the destination 567 PortID dest_id = findPort(pkt->getAddr()); 568 569 // forward the request to the appropriate destination 570 Tick response_latency = masterPorts[dest_id]->sendAtomic(pkt); 571 572 // if we got a response from a snooper, restore it here 573 if (snoop_response_cmd != MemCmd::InvalidCmd) { 574 // no one else should have responded 575 assert(!pkt->isResponse()); 576 pkt->cmd = snoop_response_cmd; 577 response_latency = snoop_response_latency; 578 } 579 580 pkt->finishTime = curTick() + response_latency; 581 return response_latency; 582} 583 584Tick 585Bus::recvAtomicSnoop(PacketPtr pkt, PortID master_port_id) 586{ 587 DPRINTF(Bus, "recvAtomicSnoop: packet src %s addr 0x%x cmd %s\n", 588 masterPorts[master_port_id]->name(), pkt->getAddr(), 589 pkt->cmdString()); 590 591 // forward to all snoopers 592 std::pair<MemCmd, Tick> snoop_result = 593 forwardAtomic(pkt, InvalidPortID); 594 MemCmd snoop_response_cmd = snoop_result.first; 595 Tick snoop_response_latency = snoop_result.second; 596 597 if (snoop_response_cmd != MemCmd::InvalidCmd) 598 pkt->cmd = snoop_response_cmd; 599 600 pkt->finishTime = curTick() + snoop_response_latency; 601 return snoop_response_latency; 602} 603 604std::pair<MemCmd, Tick> 605Bus::forwardAtomic(PacketPtr pkt, PortID exclude_slave_port_id) 606{ 607 // the packet may be changed on snoops, record the original 608 // command to enable us to restore it between snoops so that 609 // additional snoops can take place properly 610 MemCmd orig_cmd = pkt->cmd; 611 MemCmd snoop_response_cmd = MemCmd::InvalidCmd; 612 Tick snoop_response_latency = 0; 613 614 for (SlavePortIter s = snoopPorts.begin(); s != snoopPorts.end(); ++s) { 615 SlavePort *p = *s; 616 // we could have gotten this request from a snooping master 617 // (corresponding to our own slave port that is also in 618 // snoopPorts) and should not send it back to where it came 619 // from 620 if (exclude_slave_port_id == InvalidPortID || 621 p->getId() != exclude_slave_port_id) { 622 Tick latency = p->sendAtomicSnoop(pkt); 623 // in contrast to a functional access, we have to keep on 624 // going as all snoopers must be updated even if we get a 625 // response 626 if (pkt->isResponse()) { 627 // response from snoop agent 628 assert(pkt->cmd != orig_cmd); 629 assert(pkt->memInhibitAsserted()); 630 // should only happen once 631 assert(snoop_response_cmd == MemCmd::InvalidCmd); 632 // save response state 633 snoop_response_cmd = pkt->cmd; 634 snoop_response_latency = latency; 635 // restore original packet state for remaining snoopers 636 pkt->cmd = orig_cmd; 637 } 638 } 639 } 640 641 // the packet is restored as part of the loop and any potential 642 // snoop response is part of the returned pair 643 return std::make_pair(snoop_response_cmd, snoop_response_latency); 644} 645 646void 647Bus::recvFunctional(PacketPtr pkt, PortID slave_port_id) 648{ 649 if (!pkt->isPrint()) { 650 // don't do DPRINTFs on PrintReq as it clutters up the output 651 DPRINTF(Bus, 652 "recvFunctional: packet src %s addr 0x%x cmd %s\n", 653 slavePorts[slave_port_id]->name(), pkt->getAddr(), 654 pkt->cmdString()); 655 } 656 657 // uncacheable requests need never be snooped 658 if (!pkt->req->isUncacheable()) { 659 // forward to all snoopers but the source 660 forwardFunctional(pkt, slave_port_id); 661 } 662 663 // there is no need to continue if the snooping has found what we 664 // were looking for and the packet is already a response 665 if (!pkt->isResponse()) { 666 PortID dest_id = findPort(pkt->getAddr()); 667 668 masterPorts[dest_id]->sendFunctional(pkt); 669 } 670} 671 672void 673Bus::recvFunctionalSnoop(PacketPtr pkt, PortID master_port_id) 674{ 675 if (!pkt->isPrint()) { 676 // don't do DPRINTFs on PrintReq as it clutters up the output 677 DPRINTF(Bus, 678 "recvFunctionalSnoop: packet src %s addr 0x%x cmd %s\n", 679 masterPorts[master_port_id]->name(), pkt->getAddr(), 680 pkt->cmdString()); 681 } 682 683 // forward to all snoopers 684 forwardFunctional(pkt, InvalidPortID); 685} 686 687void 688Bus::forwardFunctional(PacketPtr pkt, PortID exclude_slave_port_id) 689{ 690 for (SlavePortIter s = snoopPorts.begin(); s != snoopPorts.end(); ++s) { 691 SlavePort *p = *s; 692 // we could have gotten this request from a snooping master 693 // (corresponding to our own slave port that is also in 694 // snoopPorts) and should not send it back to where it came 695 // from 696 if (exclude_slave_port_id == InvalidPortID || 697 p->getId() != exclude_slave_port_id) 698 p->sendFunctionalSnoop(pkt); 699 700 // if we get a response we are done 701 if (pkt->isResponse()) { 702 break; 703 } 704 } 705} 706 707/** Function called by the port when the bus is receiving a range change.*/ 708void 709Bus::recvRangeChange(PortID master_port_id) 710{ 711 AddrRangeList ranges; 712 AddrRangeIter iter; 713 714 if (inRecvRangeChange.count(master_port_id)) 715 return; 716 inRecvRangeChange.insert(master_port_id); 717 718 DPRINTF(BusAddrRanges, "received RangeChange from device id %d\n", 719 master_port_id); 720 721 clearPortCache(); 722 if (master_port_id == defaultPortID) { 723 defaultRange.clear(); 724 // Only try to update these ranges if the user set a default responder. 725 if (useDefaultRange) { 726 AddrRangeList ranges = 727 masterPorts[master_port_id]->getSlavePort().getAddrRanges(); 728 for(iter = ranges.begin(); iter != ranges.end(); iter++) { 729 defaultRange.push_back(*iter); 730 DPRINTF(BusAddrRanges, "Adding range %#llx - %#llx for default range\n", 731 iter->start, iter->end); 732 } 733 } 734 } else { 735 736 assert(master_port_id < masterPorts.size() && master_port_id >= 0); 737 MasterPort *port = masterPorts[master_port_id]; 738 739 // Clean out any previously existent ids 740 for (PortIter portIter = portMap.begin(); 741 portIter != portMap.end(); ) { 742 if (portIter->second == master_port_id) 743 portMap.erase(portIter++); 744 else 745 portIter++; 746 } 747 748 ranges = port->getSlavePort().getAddrRanges(); 749 750 for (iter = ranges.begin(); iter != ranges.end(); iter++) { 751 DPRINTF(BusAddrRanges, "Adding range %#llx - %#llx for id %d\n", 752 iter->start, iter->end, master_port_id); 753 if (portMap.insert(*iter, master_port_id) == portMap.end()) { 754 PortID conflict_id = portMap.find(*iter)->second; 755 fatal("%s has two ports with same range:\n\t%s\n\t%s\n", 756 name(), 757 masterPorts[master_port_id]->getSlavePort().name(), 758 masterPorts[conflict_id]->getSlavePort().name()); 759 } 760 } 761 } 762 DPRINTF(BusAddrRanges, "port list has %d entries\n", portMap.size()); 763 764 // tell all our neighbouring master ports that our address range 765 // has changed 766 for (SlavePortConstIter p = slavePorts.begin(); p != slavePorts.end(); 767 ++p) 768 (*p)->sendRangeChange(); 769 770 inRecvRangeChange.erase(master_port_id); 771} 772 773AddrRangeList 774Bus::getAddrRanges() 775{ 776 AddrRangeList ranges; 777 778 DPRINTF(BusAddrRanges, "received address range request, returning:\n"); 779 780 for (AddrRangeIter dflt_iter = defaultRange.begin(); 781 dflt_iter != defaultRange.end(); dflt_iter++) { 782 ranges.push_back(*dflt_iter); 783 DPRINTF(BusAddrRanges, " -- Dflt: %#llx : %#llx\n",dflt_iter->start, 784 dflt_iter->end); 785 } 786 for (PortIter portIter = portMap.begin(); 787 portIter != portMap.end(); portIter++) { 788 bool subset = false; 789 for (AddrRangeIter dflt_iter = defaultRange.begin(); 790 dflt_iter != defaultRange.end(); dflt_iter++) { 791 if ((portIter->first.start < dflt_iter->start && 792 portIter->first.end >= dflt_iter->start) || 793 (portIter->first.start < dflt_iter->end && 794 portIter->first.end >= dflt_iter->end)) 795 fatal("Devices can not set ranges that itersect the default set\ 796 but are not a subset of the default set.\n"); 797 if (portIter->first.start >= dflt_iter->start && 798 portIter->first.end <= dflt_iter->end) { 799 subset = true; 800 DPRINTF(BusAddrRanges, " -- %#llx : %#llx is a SUBSET\n", 801 portIter->first.start, portIter->first.end); 802 } 803 } 804 if (!subset) { 805 ranges.push_back(portIter->first); 806 DPRINTF(BusAddrRanges, " -- %#llx : %#llx\n", 807 portIter->first.start, portIter->first.end); 808 } 809 } 810 811 return ranges; 812} 813 814bool 815Bus::isSnooping() const 816{ 817 // in essence, answer the question if there are snooping ports 818 return !snoopPorts.empty(); 819} 820 821unsigned 822Bus::findBlockSize() 823{ 824 if (cachedBlockSizeValid) 825 return cachedBlockSize; 826 827 unsigned max_bs = 0; 828 829 PortIter p_end = portMap.end(); 830 for (PortIter p_iter = portMap.begin(); p_iter != p_end; p_iter++) { 831 unsigned tmp_bs = masterPorts[p_iter->second]->peerBlockSize(); 832 if (tmp_bs > max_bs) 833 max_bs = tmp_bs; 834 } 835 836 for (SlavePortConstIter s = snoopPorts.begin(); s != snoopPorts.end(); 837 ++s) { 838 unsigned tmp_bs = (*s)->peerBlockSize(); 839 if (tmp_bs > max_bs) 840 max_bs = tmp_bs; 841 } 842 if (max_bs == 0) 843 max_bs = defaultBlockSize; 844 845 if (max_bs != 64) 846 warn_once("Blocksize found to not be 64... hmm... probably not.\n"); 847 cachedBlockSize = max_bs; 848 cachedBlockSizeValid = true; 849 return max_bs; 850} 851 852 853unsigned int 854Bus::drain(Event * de) 855{ 856 //We should check that we're not "doing" anything, and that noone is 857 //waiting. We might be idle but have someone waiting if the device we 858 //contacted for a retry didn't actually retry. 859 if (!retryList.empty() || (curTick() < tickNextIdle && 860 busIdleEvent.scheduled())) { 861 drainEvent = de; 862 return 1; 863 } 864 return 0; 865} 866 867void 868Bus::startup() 869{ 870 if (tickNextIdle < curTick()) 871 tickNextIdle = (curTick() / clock) * clock + clock; 872} 873 874Bus * 875BusParams::create() 876{ 877 return new Bus(this); 878} 879