coherent_xbar.cc revision 9031
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) 202{ 203 // determine the source port based on the id 204 SlavePort *src_port = slavePorts[pkt->getSrc()]; 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 Tick headerFinishTime = pkt->isExpressSnoop() ? 0 : calcPacketTiming(pkt); 218 Tick packetFinishTime = pkt->isExpressSnoop() ? 0 : pkt->finishTime; 219 220 // uncacheable requests need never be snooped 221 if (!pkt->req->isUncacheable()) { 222 // the packet is a memory-mapped request and should be 223 // broadcasted to our snoopers but the source 224 forwardTiming(pkt, pkt->getSrc()); 225 } 226 227 // remember if we add an outstanding req so we can undo it if 228 // necessary, if the packet needs a response, we should add it 229 // as outstanding and express snoops never fail so there is 230 // not need to worry about them 231 bool add_outstanding = !pkt->isExpressSnoop() && pkt->needsResponse(); 232 233 // keep track that we have an outstanding request packet 234 // matching this request, this is used by the coherency 235 // mechanism in determining what to do with snoop responses 236 // (in recvTimingSnoop) 237 if (add_outstanding) { 238 // we should never have an exsiting request outstanding 239 assert(outstandingReq.find(pkt->req) == outstandingReq.end()); 240 outstandingReq.insert(pkt->req); 241 } 242 243 // since it is a normal request, determine the destination 244 // based on the address and attempt to send the packet 245 bool success = masterPorts[findPort(pkt->getAddr())]->sendTimingReq(pkt); 246 247 if (!success) { 248 // inhibited packets should never be forced to retry 249 assert(!pkt->memInhibitAsserted()); 250 251 // if it was added as outstanding and the send failed, then 252 // erase it again 253 if (add_outstanding) 254 outstandingReq.erase(pkt->req); 255 256 DPRINTF(Bus, "recvTimingReq: src %s %s 0x%x RETRY\n", 257 src_port->name(), pkt->cmdString(), pkt->getAddr()); 258 259 addToRetryList(src_port); 260 occupyBus(headerFinishTime); 261 262 return false; 263 } 264 265 succeededTiming(packetFinishTime); 266 267 return true; 268} 269 270bool 271Bus::recvTimingResp(PacketPtr pkt) 272{ 273 // determine the source port based on the id 274 MasterPort *src_port = masterPorts[pkt->getSrc()]; 275 276 // test if the bus should be considered occupied for the current 277 // packet 278 if (isOccupied(pkt, src_port)) { 279 DPRINTF(Bus, "recvTimingResp: src %s %s 0x%x BUSY\n", 280 src_port->name(), pkt->cmdString(), pkt->getAddr()); 281 return false; 282 } 283 284 DPRINTF(Bus, "recvTimingResp: src %s %s 0x%x\n", 285 src_port->name(), pkt->cmdString(), pkt->getAddr()); 286 287 calcPacketTiming(pkt); 288 Tick packetFinishTime = pkt->finishTime; 289 290 // the packet is a normal response to a request that we should 291 // have seen passing through the bus 292 assert(outstandingReq.find(pkt->req) != outstandingReq.end()); 293 294 // remove it as outstanding 295 outstandingReq.erase(pkt->req); 296 297 // send the packet to the destination through one of our slave 298 // ports, as determined by the destination field 299 bool success M5_VAR_USED = slavePorts[pkt->getDest()]->sendTimingResp(pkt); 300 301 // currently it is illegal to block responses... can lead to 302 // deadlock 303 assert(success); 304 305 succeededTiming(packetFinishTime); 306 307 return true; 308} 309 310void 311Bus::recvTimingSnoopReq(PacketPtr pkt) 312{ 313 DPRINTF(Bus, "recvTimingSnoopReq: src %s %s 0x%x\n", 314 masterPorts[pkt->getSrc()]->name(), pkt->cmdString(), 315 pkt->getAddr()); 316 317 // we should only see express snoops from caches 318 assert(pkt->isExpressSnoop()); 319 320 // forward to all snoopers 321 forwardTiming(pkt, InvalidPortID); 322 323 // a snoop request came from a connected slave device (one of 324 // our master ports), and if it is not coming from the slave 325 // device responsible for the address range something is 326 // wrong, hence there is nothing further to do as the packet 327 // would be going back to where it came from 328 assert(pkt->getSrc() == findPort(pkt->getAddr())); 329 330 // this is an express snoop and is never forced to retry 331 assert(!inRetry); 332} 333 334bool 335Bus::recvTimingSnoopResp(PacketPtr pkt) 336{ 337 // determine the source port based on the id 338 SlavePort* src_port = slavePorts[pkt->getSrc()]; 339 340 if (isOccupied(pkt, src_port)) { 341 DPRINTF(Bus, "recvTimingSnoopResp: src %s %s 0x%x BUSY\n", 342 src_port->name(), pkt->cmdString(), pkt->getAddr()); 343 return false; 344 } 345 346 DPRINTF(Bus, "recvTimingSnoop: src %s %s 0x%x\n", 347 src_port->name(), pkt->cmdString(), pkt->getAddr()); 348 349 // get the destination from the packet 350 PortID dest = pkt->getDest(); 351 352 // responses are never express snoops 353 assert(!pkt->isExpressSnoop()); 354 355 calcPacketTiming(pkt); 356 Tick packetFinishTime = pkt->finishTime; 357 358 // determine if the response is from a snoop request we 359 // created as the result of a normal request (in which case it 360 // should be in the outstandingReq), or if we merely forwarded 361 // someone else's snoop request 362 if (outstandingReq.find(pkt->req) == outstandingReq.end()) { 363 // this is a snoop response to a snoop request we 364 // forwarded, e.g. coming from the L1 and going to the L2 365 // this should be forwarded as a snoop response 366 bool success M5_VAR_USED = masterPorts[dest]->sendTimingSnoopResp(pkt); 367 assert(success); 368 } else { 369 // we got a snoop response on one of our slave ports, 370 // i.e. from a coherent master connected to the bus, and 371 // since we created the snoop request as part of 372 // recvTiming, this should now be a normal response again 373 outstandingReq.erase(pkt->req); 374 375 // this is a snoop response from a coherent master, with a 376 // destination field set on its way through the bus as 377 // request, hence it should never go back to where the 378 // snoop response came from, but instead to where the 379 // original request came from 380 assert(pkt->getSrc() != dest); 381 382 // as a normal response, it should go back to a master 383 // through one of our slave ports 384 bool success M5_VAR_USED = slavePorts[dest]->sendTimingResp(pkt); 385 386 // currently it is illegal to block responses... can lead 387 // to deadlock 388 assert(success); 389 } 390 391 succeededTiming(packetFinishTime); 392 393 return true; 394} 395 396 397void 398Bus::succeededTiming(Tick busy_time) 399{ 400 // occupy the bus accordingly 401 occupyBus(busy_time); 402 403 // if a retrying port succeeded, also take it off the retry list 404 if (inRetry) { 405 DPRINTF(Bus, "Remove retry from list %s\n", 406 retryList.front()->name()); 407 retryList.pop_front(); 408 inRetry = false; 409 } 410} 411 412void 413Bus::forwardTiming(PacketPtr pkt, PortID exclude_slave_port_id) 414{ 415 for (SlavePortIter s = snoopPorts.begin(); s != snoopPorts.end(); ++s) { 416 SlavePort *p = *s; 417 // we could have gotten this request from a snooping master 418 // (corresponding to our own slave port that is also in 419 // snoopPorts) and should not send it back to where it came 420 // from 421 if (exclude_slave_port_id == InvalidPortID || 422 p->getId() != exclude_slave_port_id) { 423 // cache is not allowed to refuse snoop 424 p->sendTimingSnoopReq(pkt); 425 } 426 } 427} 428 429void 430Bus::releaseBus() 431{ 432 // releasing the bus means we should now be idle 433 assert(curTick() >= tickNextIdle); 434 435 // bus is now idle, so if someone is waiting we can retry 436 if (!retryList.empty()) { 437 // note that we block (return false on recvTiming) both 438 // because the bus is busy and because the destination is 439 // busy, and in the latter case the bus may be released before 440 // we see a retry from the destination 441 retryWaiting(); 442 } 443 444 //If we weren't able to drain before, we might be able to now. 445 if (drainEvent && retryList.empty() && curTick() >= tickNextIdle) { 446 drainEvent->process(); 447 // Clear the drain event once we're done with it. 448 drainEvent = NULL; 449 } 450} 451 452void 453Bus::retryWaiting() 454{ 455 // this should never be called with an empty retry list 456 assert(!retryList.empty()); 457 458 // send a retry to the port at the head of the retry list 459 inRetry = true; 460 461 // note that we might have blocked on the receiving port being 462 // busy (rather than the bus itself) and now call retry before the 463 // destination called retry on the bus 464 retryList.front()->sendRetry(); 465 466 // If inRetry is still true, sendTiming wasn't called in zero time 467 // (e.g. the cache does this) 468 if (inRetry) { 469 retryList.pop_front(); 470 inRetry = false; 471 472 //Bring tickNextIdle up to the present 473 while (tickNextIdle < curTick()) 474 tickNextIdle += clock; 475 476 //Burn a cycle for the missed grant. 477 tickNextIdle += clock; 478 479 reschedule(busIdleEvent, tickNextIdle, true); 480 } 481} 482 483void 484Bus::recvRetry(PortID id) 485{ 486 // we got a retry from a peer that we tried to send something to 487 // and failed, but we sent it on the account of someone else, and 488 // that source port should be on our retry list, however if the 489 // bus is released before this happens and the retry (from the bus 490 // point of view) is successful then this no longer holds and we 491 // could in fact have an empty retry list 492 if (retryList.empty()) 493 return; 494 495 // if the bus isn't busy 496 if (curTick() >= tickNextIdle) { 497 // note that we do not care who told us to retry at the moment, we 498 // merely let the first one on the retry list go 499 retryWaiting(); 500 } 501} 502 503PortID 504Bus::findPort(Addr addr) 505{ 506 /* An interval tree would be a better way to do this. --ali. */ 507 PortID dest_id = checkPortCache(addr); 508 if (dest_id != InvalidPortID) 509 return dest_id; 510 511 // Check normal port ranges 512 PortIter i = portMap.find(RangeSize(addr,1)); 513 if (i != portMap.end()) { 514 dest_id = i->second; 515 updatePortCache(dest_id, i->first.start, i->first.end); 516 return dest_id; 517 } 518 519 // Check if this matches the default range 520 if (useDefaultRange) { 521 AddrRangeIter a_end = defaultRange.end(); 522 for (AddrRangeIter i = defaultRange.begin(); i != a_end; i++) { 523 if (*i == addr) { 524 DPRINTF(Bus, " found addr %#llx on default\n", addr); 525 return defaultPortID; 526 } 527 } 528 } else if (defaultPortID != InvalidPortID) { 529 DPRINTF(Bus, "Unable to find destination for addr %#llx, " 530 "will use default port\n", addr); 531 return defaultPortID; 532 } 533 534 // we should use the range for the default port and it did not 535 // match, or the default port is not set 536 fatal("Unable to find destination for addr %#llx on bus %s\n", addr, 537 name()); 538} 539 540Tick 541Bus::recvAtomic(PacketPtr pkt) 542{ 543 DPRINTF(Bus, "recvAtomic: packet src %s addr 0x%x cmd %s\n", 544 slavePorts[pkt->getSrc()]->name(), pkt->getAddr(), 545 pkt->cmdString()); 546 547 MemCmd snoop_response_cmd = MemCmd::InvalidCmd; 548 Tick snoop_response_latency = 0; 549 550 // uncacheable requests need never be snooped 551 if (!pkt->req->isUncacheable()) { 552 // forward to all snoopers but the source 553 std::pair<MemCmd, Tick> snoop_result = 554 forwardAtomic(pkt, pkt->getSrc()); 555 snoop_response_cmd = snoop_result.first; 556 snoop_response_latency = snoop_result.second; 557 } 558 559 // even if we had a snoop response, we must continue and also 560 // perform the actual request at the destination 561 PortID dest_id = findPort(pkt->getAddr()); 562 563 // forward the request to the appropriate destination 564 Tick response_latency = masterPorts[dest_id]->sendAtomic(pkt); 565 566 // if we got a response from a snooper, restore it here 567 if (snoop_response_cmd != MemCmd::InvalidCmd) { 568 // no one else should have responded 569 assert(!pkt->isResponse()); 570 pkt->cmd = snoop_response_cmd; 571 response_latency = snoop_response_latency; 572 } 573 574 pkt->finishTime = curTick() + response_latency; 575 return response_latency; 576} 577 578Tick 579Bus::recvAtomicSnoop(PacketPtr pkt) 580{ 581 DPRINTF(Bus, "recvAtomicSnoop: packet src %s addr 0x%x cmd %s\n", 582 masterPorts[pkt->getSrc()]->name(), pkt->getAddr(), 583 pkt->cmdString()); 584 585 // forward to all snoopers 586 std::pair<MemCmd, Tick> snoop_result = 587 forwardAtomic(pkt, InvalidPortID); 588 MemCmd snoop_response_cmd = snoop_result.first; 589 Tick snoop_response_latency = snoop_result.second; 590 591 if (snoop_response_cmd != MemCmd::InvalidCmd) 592 pkt->cmd = snoop_response_cmd; 593 594 pkt->finishTime = curTick() + snoop_response_latency; 595 return snoop_response_latency; 596} 597 598std::pair<MemCmd, Tick> 599Bus::forwardAtomic(PacketPtr pkt, PortID exclude_slave_port_id) 600{ 601 // the packet may be changed on snoops, record the original source 602 // and command to enable us to restore it between snoops so that 603 // additional snoops can take place properly 604 PortID orig_src_id = pkt->getSrc(); 605 MemCmd orig_cmd = pkt->cmd; 606 MemCmd snoop_response_cmd = MemCmd::InvalidCmd; 607 Tick snoop_response_latency = 0; 608 609 for (SlavePortIter s = snoopPorts.begin(); s != snoopPorts.end(); ++s) { 610 SlavePort *p = *s; 611 // we could have gotten this request from a snooping master 612 // (corresponding to our own slave port that is also in 613 // snoopPorts) and should not send it back to where it came 614 // from 615 if (exclude_slave_port_id == InvalidPortID || 616 p->getId() != exclude_slave_port_id) { 617 Tick latency = p->sendAtomicSnoop(pkt); 618 // in contrast to a functional access, we have to keep on 619 // going as all snoopers must be updated even if we get a 620 // response 621 if (pkt->isResponse()) { 622 // response from snoop agent 623 assert(pkt->cmd != orig_cmd); 624 assert(pkt->memInhibitAsserted()); 625 // should only happen once 626 assert(snoop_response_cmd == MemCmd::InvalidCmd); 627 // save response state 628 snoop_response_cmd = pkt->cmd; 629 snoop_response_latency = latency; 630 // restore original packet state for remaining snoopers 631 pkt->cmd = orig_cmd; 632 pkt->setSrc(orig_src_id); 633 pkt->clearDest(); 634 } 635 } 636 } 637 638 // the packet is restored as part of the loop and any potential 639 // snoop response is part of the returned pair 640 return std::make_pair(snoop_response_cmd, snoop_response_latency); 641} 642 643void 644Bus::recvFunctional(PacketPtr pkt) 645{ 646 if (!pkt->isPrint()) { 647 // don't do DPRINTFs on PrintReq as it clutters up the output 648 DPRINTF(Bus, 649 "recvFunctional: packet src %s addr 0x%x cmd %s\n", 650 slavePorts[pkt->getSrc()]->name(), pkt->getAddr(), 651 pkt->cmdString()); 652 } 653 654 // uncacheable requests need never be snooped 655 if (!pkt->req->isUncacheable()) { 656 // forward to all snoopers but the source 657 forwardFunctional(pkt, pkt->getSrc()); 658 } 659 660 // there is no need to continue if the snooping has found what we 661 // were looking for and the packet is already a response 662 if (!pkt->isResponse()) { 663 PortID dest_id = findPort(pkt->getAddr()); 664 665 masterPorts[dest_id]->sendFunctional(pkt); 666 } 667} 668 669void 670Bus::recvFunctionalSnoop(PacketPtr pkt) 671{ 672 if (!pkt->isPrint()) { 673 // don't do DPRINTFs on PrintReq as it clutters up the output 674 DPRINTF(Bus, 675 "recvFunctionalSnoop: packet src %s addr 0x%x cmd %s\n", 676 masterPorts[pkt->getSrc()]->name(), pkt->getAddr(), 677 pkt->cmdString()); 678 } 679 680 // forward to all snoopers 681 forwardFunctional(pkt, InvalidPortID); 682} 683 684void 685Bus::forwardFunctional(PacketPtr pkt, PortID exclude_slave_port_id) 686{ 687 for (SlavePortIter s = snoopPorts.begin(); s != snoopPorts.end(); ++s) { 688 SlavePort *p = *s; 689 // we could have gotten this request from a snooping master 690 // (corresponding to our own slave port that is also in 691 // snoopPorts) and should not send it back to where it came 692 // from 693 if (exclude_slave_port_id == InvalidPortID || 694 p->getId() != exclude_slave_port_id) 695 p->sendFunctionalSnoop(pkt); 696 697 // if we get a response we are done 698 if (pkt->isResponse()) { 699 break; 700 } 701 } 702} 703 704/** Function called by the port when the bus is receiving a range change.*/ 705void 706Bus::recvRangeChange(PortID id) 707{ 708 AddrRangeList ranges; 709 AddrRangeIter iter; 710 711 if (inRecvRangeChange.count(id)) 712 return; 713 inRecvRangeChange.insert(id); 714 715 DPRINTF(BusAddrRanges, "received RangeChange from device id %d\n", id); 716 717 clearPortCache(); 718 if (id == defaultPortID) { 719 defaultRange.clear(); 720 // Only try to update these ranges if the user set a default responder. 721 if (useDefaultRange) { 722 AddrRangeList ranges = 723 masterPorts[id]->getSlavePort().getAddrRanges(); 724 for(iter = ranges.begin(); iter != ranges.end(); iter++) { 725 defaultRange.push_back(*iter); 726 DPRINTF(BusAddrRanges, "Adding range %#llx - %#llx for default range\n", 727 iter->start, iter->end); 728 } 729 } 730 } else { 731 732 assert(id < masterPorts.size() && id >= 0); 733 MasterPort *port = masterPorts[id]; 734 735 // Clean out any previously existent ids 736 for (PortIter portIter = portMap.begin(); 737 portIter != portMap.end(); ) { 738 if (portIter->second == id) 739 portMap.erase(portIter++); 740 else 741 portIter++; 742 } 743 744 ranges = port->getSlavePort().getAddrRanges(); 745 746 for (iter = ranges.begin(); iter != ranges.end(); iter++) { 747 DPRINTF(BusAddrRanges, "Adding range %#llx - %#llx for id %d\n", 748 iter->start, iter->end, id); 749 if (portMap.insert(*iter, id) == portMap.end()) { 750 PortID conflict_id = portMap.find(*iter)->second; 751 fatal("%s has two ports with same range:\n\t%s\n\t%s\n", 752 name(), masterPorts[id]->getSlavePort().name(), 753 masterPorts[conflict_id]->getSlavePort().name()); 754 } 755 } 756 } 757 DPRINTF(BusAddrRanges, "port list has %d entries\n", portMap.size()); 758 759 // tell all our neighbouring master ports that our address range 760 // has changed 761 for (SlavePortConstIter p = slavePorts.begin(); p != slavePorts.end(); 762 ++p) 763 (*p)->sendRangeChange(); 764 765 inRecvRangeChange.erase(id); 766} 767 768AddrRangeList 769Bus::getAddrRanges(PortID id) 770{ 771 AddrRangeList ranges; 772 773 DPRINTF(BusAddrRanges, "received address range request, returning:\n"); 774 775 for (AddrRangeIter dflt_iter = defaultRange.begin(); 776 dflt_iter != defaultRange.end(); dflt_iter++) { 777 ranges.push_back(*dflt_iter); 778 DPRINTF(BusAddrRanges, " -- Dflt: %#llx : %#llx\n",dflt_iter->start, 779 dflt_iter->end); 780 } 781 for (PortIter portIter = portMap.begin(); 782 portIter != portMap.end(); portIter++) { 783 bool subset = false; 784 for (AddrRangeIter dflt_iter = defaultRange.begin(); 785 dflt_iter != defaultRange.end(); dflt_iter++) { 786 if ((portIter->first.start < dflt_iter->start && 787 portIter->first.end >= dflt_iter->start) || 788 (portIter->first.start < dflt_iter->end && 789 portIter->first.end >= dflt_iter->end)) 790 fatal("Devices can not set ranges that itersect the default set\ 791 but are not a subset of the default set.\n"); 792 if (portIter->first.start >= dflt_iter->start && 793 portIter->first.end <= dflt_iter->end) { 794 subset = true; 795 DPRINTF(BusAddrRanges, " -- %#llx : %#llx is a SUBSET\n", 796 portIter->first.start, portIter->first.end); 797 } 798 } 799 if (portIter->second != id && !subset) { 800 ranges.push_back(portIter->first); 801 DPRINTF(BusAddrRanges, " -- %#llx : %#llx\n", 802 portIter->first.start, portIter->first.end); 803 } 804 } 805 806 return ranges; 807} 808 809bool 810Bus::isSnooping(PortID id) const 811{ 812 // in essence, answer the question if there are snooping ports 813 return !snoopPorts.empty(); 814} 815 816unsigned 817Bus::findBlockSize(PortID id) 818{ 819 if (cachedBlockSizeValid) 820 return cachedBlockSize; 821 822 unsigned max_bs = 0; 823 824 PortIter p_end = portMap.end(); 825 for (PortIter p_iter = portMap.begin(); p_iter != p_end; p_iter++) { 826 unsigned tmp_bs = masterPorts[p_iter->second]->peerBlockSize(); 827 if (tmp_bs > max_bs) 828 max_bs = tmp_bs; 829 } 830 831 for (SlavePortConstIter s = snoopPorts.begin(); s != snoopPorts.end(); 832 ++s) { 833 unsigned tmp_bs = (*s)->peerBlockSize(); 834 if (tmp_bs > max_bs) 835 max_bs = tmp_bs; 836 } 837 if (max_bs == 0) 838 max_bs = defaultBlockSize; 839 840 if (max_bs != 64) 841 warn_once("Blocksize found to not be 64... hmm... probably not.\n"); 842 cachedBlockSize = max_bs; 843 cachedBlockSizeValid = true; 844 return max_bs; 845} 846 847 848unsigned int 849Bus::drain(Event * de) 850{ 851 //We should check that we're not "doing" anything, and that noone is 852 //waiting. We might be idle but have someone waiting if the device we 853 //contacted for a retry didn't actually retry. 854 if (!retryList.empty() || (curTick() < tickNextIdle && 855 busIdleEvent.scheduled())) { 856 drainEvent = de; 857 return 1; 858 } 859 return 0; 860} 861 862void 863Bus::startup() 864{ 865 if (tickNextIdle < curTick()) 866 tickNextIdle = (curTick() / clock) * clock + clock; 867} 868 869Bus * 870BusParams::create() 871{ 872 return new Bus(this); 873} 874