coherent_xbar.cc revision 8975
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(Port::INVALID_PORT_ID), 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 // the packet is a memory-mapped request and should be 221 // broadcasted to our snoopers but the source 222 forwardTiming(pkt, pkt->getSrc()); 223 224 // remember if we add an outstanding req so we can undo it if 225 // necessary, if the packet needs a response, we should add it 226 // as outstanding and express snoops never fail so there is 227 // not need to worry about them 228 bool add_outstanding = !pkt->isExpressSnoop() && pkt->needsResponse(); 229 230 // keep track that we have an outstanding request packet 231 // matching this request, this is used by the coherency 232 // mechanism in determining what to do with snoop responses 233 // (in recvTimingSnoop) 234 if (add_outstanding) { 235 // we should never have an exsiting request outstanding 236 assert(outstandingReq.find(pkt->req) == outstandingReq.end()); 237 outstandingReq.insert(pkt->req); 238 } 239 240 // since it is a normal request, determine the destination 241 // based on the address and attempt to send the packet 242 bool success = masterPorts[findPort(pkt->getAddr())]->sendTimingReq(pkt); 243 244 if (!success) { 245 // inhibited packets should never be forced to retry 246 assert(!pkt->memInhibitAsserted()); 247 248 // if it was added as outstanding and the send failed, then 249 // erase it again 250 if (add_outstanding) 251 outstandingReq.erase(pkt->req); 252 253 DPRINTF(Bus, "recvTimingReq: src %s %s 0x%x RETRY\n", 254 src_port->name(), pkt->cmdString(), pkt->getAddr()); 255 256 addToRetryList(src_port); 257 occupyBus(headerFinishTime); 258 259 return false; 260 } 261 262 succeededTiming(packetFinishTime); 263 264 return true; 265} 266 267bool 268Bus::recvTimingResp(PacketPtr pkt) 269{ 270 // determine the source port based on the id 271 MasterPort *src_port = masterPorts[pkt->getSrc()]; 272 273 // test if the bus should be considered occupied for the current 274 // packet 275 if (isOccupied(pkt, src_port)) { 276 DPRINTF(Bus, "recvTimingResp: src %s %s 0x%x BUSY\n", 277 src_port->name(), pkt->cmdString(), pkt->getAddr()); 278 return false; 279 } 280 281 DPRINTF(Bus, "recvTimingResp: src %s %s 0x%x\n", 282 src_port->name(), pkt->cmdString(), pkt->getAddr()); 283 284 calcPacketTiming(pkt); 285 Tick packetFinishTime = pkt->finishTime; 286 287 // the packet is a normal response to a request that we should 288 // have seen passing through the bus 289 assert(outstandingReq.find(pkt->req) != outstandingReq.end()); 290 291 // remove it as outstanding 292 outstandingReq.erase(pkt->req); 293 294 // send the packet to the destination through one of our slave 295 // ports, as determined by the destination field 296 bool success M5_VAR_USED = slavePorts[pkt->getDest()]->sendTimingResp(pkt); 297 298 // currently it is illegal to block responses... can lead to 299 // deadlock 300 assert(success); 301 302 succeededTiming(packetFinishTime); 303 304 return true; 305} 306 307void 308Bus::recvTimingSnoopReq(PacketPtr pkt) 309{ 310 DPRINTF(Bus, "recvTimingSnoopReq: src %s %s 0x%x\n", 311 masterPorts[pkt->getSrc()]->name(), pkt->cmdString(), 312 pkt->getAddr()); 313 314 // we should only see express snoops from caches 315 assert(pkt->isExpressSnoop()); 316 317 // forward to all snoopers 318 forwardTiming(pkt, Port::INVALID_PORT_ID); 319 320 // a snoop request came from a connected slave device (one of 321 // our master ports), and if it is not coming from the slave 322 // device responsible for the address range something is 323 // wrong, hence there is nothing further to do as the packet 324 // would be going back to where it came from 325 assert(pkt->getSrc() == findPort(pkt->getAddr())); 326 327 // this is an express snoop and is never forced to retry 328 assert(!inRetry); 329} 330 331bool 332Bus::recvTimingSnoopResp(PacketPtr pkt) 333{ 334 // determine the source port based on the id 335 SlavePort* src_port = slavePorts[pkt->getSrc()]; 336 337 if (isOccupied(pkt, src_port)) { 338 DPRINTF(Bus, "recvTimingSnoopResp: src %s %s 0x%x BUSY\n", 339 src_port->name(), pkt->cmdString(), pkt->getAddr()); 340 return false; 341 } 342 343 DPRINTF(Bus, "recvTimingSnoop: src %s %s 0x%x\n", 344 src_port->name(), pkt->cmdString(), pkt->getAddr()); 345 346 // get the destination from the packet 347 Packet::NodeID dest = pkt->getDest(); 348 349 // responses are never express snoops 350 assert(!pkt->isExpressSnoop()); 351 352 calcPacketTiming(pkt); 353 Tick packetFinishTime = pkt->finishTime; 354 355 // determine if the response is from a snoop request we 356 // created as the result of a normal request (in which case it 357 // should be in the outstandingReq), or if we merely forwarded 358 // someone else's snoop request 359 if (outstandingReq.find(pkt->req) == outstandingReq.end()) { 360 // this is a snoop response to a snoop request we 361 // forwarded, e.g. coming from the L1 and going to the L2 362 // this should be forwarded as a snoop response 363 bool success M5_VAR_USED = masterPorts[dest]->sendTimingSnoopResp(pkt); 364 assert(success); 365 } else { 366 // we got a snoop response on one of our slave ports, 367 // i.e. from a coherent master connected to the bus, and 368 // since we created the snoop request as part of 369 // recvTiming, this should now be a normal response again 370 outstandingReq.erase(pkt->req); 371 372 // this is a snoop response from a coherent master, with a 373 // destination field set on its way through the bus as 374 // request, hence it should never go back to where the 375 // snoop response came from, but instead to where the 376 // original request came from 377 assert(pkt->getSrc() != dest); 378 379 // as a normal response, it should go back to a master 380 // through one of our slave ports 381 bool success M5_VAR_USED = slavePorts[dest]->sendTimingResp(pkt); 382 383 // currently it is illegal to block responses... can lead 384 // to deadlock 385 assert(success); 386 } 387 388 succeededTiming(packetFinishTime); 389 390 return true; 391} 392 393 394void 395Bus::succeededTiming(Tick busy_time) 396{ 397 // occupy the bus accordingly 398 occupyBus(busy_time); 399 400 // if a retrying port succeeded, also take it off the retry list 401 if (inRetry) { 402 DPRINTF(Bus, "Remove retry from list %s\n", 403 retryList.front()->name()); 404 retryList.pop_front(); 405 inRetry = false; 406 } 407} 408 409void 410Bus::forwardTiming(PacketPtr pkt, int exclude_slave_port_id) 411{ 412 for (SlavePortIter s = snoopPorts.begin(); s != snoopPorts.end(); ++s) { 413 SlavePort *p = *s; 414 // we could have gotten this request from a snooping master 415 // (corresponding to our own slave port that is also in 416 // snoopPorts) and should not send it back to where it came 417 // from 418 if (exclude_slave_port_id == Port::INVALID_PORT_ID || 419 p->getId() != exclude_slave_port_id) { 420 // cache is not allowed to refuse snoop 421 p->sendTimingSnoopReq(pkt); 422 } 423 } 424} 425 426void 427Bus::releaseBus() 428{ 429 // releasing the bus means we should now be idle 430 assert(curTick() >= tickNextIdle); 431 432 // bus is now idle, so if someone is waiting we can retry 433 if (!retryList.empty()) { 434 // note that we block (return false on recvTiming) both 435 // because the bus is busy and because the destination is 436 // busy, and in the latter case the bus may be released before 437 // we see a retry from the destination 438 retryWaiting(); 439 } 440 441 //If we weren't able to drain before, we might be able to now. 442 if (drainEvent && retryList.empty() && curTick() >= tickNextIdle) { 443 drainEvent->process(); 444 // Clear the drain event once we're done with it. 445 drainEvent = NULL; 446 } 447} 448 449void 450Bus::retryWaiting() 451{ 452 // this should never be called with an empty retry list 453 assert(!retryList.empty()); 454 455 // send a retry to the port at the head of the retry list 456 inRetry = true; 457 458 // note that we might have blocked on the receiving port being 459 // busy (rather than the bus itself) and now call retry before the 460 // destination called retry on the bus 461 retryList.front()->sendRetry(); 462 463 // If inRetry is still true, sendTiming wasn't called in zero time 464 // (e.g. the cache does this) 465 if (inRetry) { 466 retryList.pop_front(); 467 inRetry = false; 468 469 //Bring tickNextIdle up to the present 470 while (tickNextIdle < curTick()) 471 tickNextIdle += clock; 472 473 //Burn a cycle for the missed grant. 474 tickNextIdle += clock; 475 476 reschedule(busIdleEvent, tickNextIdle, true); 477 } 478} 479 480void 481Bus::recvRetry(Port::PortId id) 482{ 483 // we got a retry from a peer that we tried to send something to 484 // and failed, but we sent it on the account of someone else, and 485 // that source port should be on our retry list, however if the 486 // bus is released before this happens and the retry (from the bus 487 // point of view) is successful then this no longer holds and we 488 // could in fact have an empty retry list 489 if (retryList.empty()) 490 return; 491 492 // if the bus isn't busy 493 if (curTick() >= tickNextIdle) { 494 // note that we do not care who told us to retry at the moment, we 495 // merely let the first one on the retry list go 496 retryWaiting(); 497 } 498} 499 500int 501Bus::findPort(Addr addr) 502{ 503 /* An interval tree would be a better way to do this. --ali. */ 504 int dest_id; 505 506 dest_id = checkPortCache(addr); 507 if (dest_id != Port::INVALID_PORT_ID) 508 return dest_id; 509 510 // Check normal port ranges 511 PortIter i = portMap.find(RangeSize(addr,1)); 512 if (i != portMap.end()) { 513 dest_id = i->second; 514 updatePortCache(dest_id, i->first.start, i->first.end); 515 return dest_id; 516 } 517 518 // Check if this matches the default range 519 if (useDefaultRange) { 520 AddrRangeIter a_end = defaultRange.end(); 521 for (AddrRangeIter i = defaultRange.begin(); i != a_end; i++) { 522 if (*i == addr) { 523 DPRINTF(Bus, " found addr %#llx on default\n", addr); 524 return defaultPortId; 525 } 526 } 527 } else if (defaultPortId != Port::INVALID_PORT_ID) { 528 DPRINTF(Bus, "Unable to find destination for addr %#llx, " 529 "will use default port\n", addr); 530 return defaultPortId; 531 } 532 533 // we should use the range for the default port and it did not 534 // match, or the default port is not set 535 fatal("Unable to find destination for addr %#llx on bus %s\n", addr, 536 name()); 537} 538 539Tick 540Bus::recvAtomic(PacketPtr pkt) 541{ 542 DPRINTF(Bus, "recvAtomic: packet src %s addr 0x%x cmd %s\n", 543 slavePorts[pkt->getSrc()]->name(), pkt->getAddr(), 544 pkt->cmdString()); 545 546 // forward to all snoopers but the source 547 std::pair<MemCmd, Tick> snoop_result = forwardAtomic(pkt, pkt->getSrc()); 548 MemCmd snoop_response_cmd = snoop_result.first; 549 Tick snoop_response_latency = snoop_result.second; 550 551 // even if we had a snoop response, we must continue and also 552 // perform the actual request at the destination 553 int dest_id = findPort(pkt->getAddr()); 554 555 // forward the request to the appropriate destination 556 Tick response_latency = masterPorts[dest_id]->sendAtomic(pkt); 557 558 // if we got a response from a snooper, restore it here 559 if (snoop_response_cmd != MemCmd::InvalidCmd) { 560 // no one else should have responded 561 assert(!pkt->isResponse()); 562 pkt->cmd = snoop_response_cmd; 563 response_latency = snoop_response_latency; 564 } 565 566 pkt->finishTime = curTick() + response_latency; 567 return response_latency; 568} 569 570Tick 571Bus::recvAtomicSnoop(PacketPtr pkt) 572{ 573 DPRINTF(Bus, "recvAtomicSnoop: packet src %s addr 0x%x cmd %s\n", 574 masterPorts[pkt->getSrc()]->name(), pkt->getAddr(), 575 pkt->cmdString()); 576 577 // forward to all snoopers 578 std::pair<MemCmd, Tick> snoop_result = 579 forwardAtomic(pkt, Port::INVALID_PORT_ID); 580 MemCmd snoop_response_cmd = snoop_result.first; 581 Tick snoop_response_latency = snoop_result.second; 582 583 if (snoop_response_cmd != MemCmd::InvalidCmd) 584 pkt->cmd = snoop_response_cmd; 585 586 pkt->finishTime = curTick() + snoop_response_latency; 587 return snoop_response_latency; 588} 589 590std::pair<MemCmd, Tick> 591Bus::forwardAtomic(PacketPtr pkt, int exclude_slave_port_id) 592{ 593 // the packet may be changed on snoops, record the original source 594 // and command to enable us to restore it between snoops so that 595 // additional snoops can take place properly 596 Packet::NodeID orig_src_id = pkt->getSrc(); 597 MemCmd orig_cmd = pkt->cmd; 598 MemCmd snoop_response_cmd = MemCmd::InvalidCmd; 599 Tick snoop_response_latency = 0; 600 601 for (SlavePortIter s = snoopPorts.begin(); s != snoopPorts.end(); ++s) { 602 SlavePort *p = *s; 603 // we could have gotten this request from a snooping master 604 // (corresponding to our own slave port that is also in 605 // snoopPorts) and should not send it back to where it came 606 // from 607 if (exclude_slave_port_id == Port::INVALID_PORT_ID || 608 p->getId() != exclude_slave_port_id) { 609 Tick latency = p->sendAtomicSnoop(pkt); 610 // in contrast to a functional access, we have to keep on 611 // going as all snoopers must be updated even if we get a 612 // response 613 if (pkt->isResponse()) { 614 // response from snoop agent 615 assert(pkt->cmd != orig_cmd); 616 assert(pkt->memInhibitAsserted()); 617 // should only happen once 618 assert(snoop_response_cmd == MemCmd::InvalidCmd); 619 // save response state 620 snoop_response_cmd = pkt->cmd; 621 snoop_response_latency = latency; 622 // restore original packet state for remaining snoopers 623 pkt->cmd = orig_cmd; 624 pkt->setSrc(orig_src_id); 625 pkt->clearDest(); 626 } 627 } 628 } 629 630 // the packet is restored as part of the loop and any potential 631 // snoop response is part of the returned pair 632 return std::make_pair(snoop_response_cmd, snoop_response_latency); 633} 634 635void 636Bus::recvFunctional(PacketPtr pkt) 637{ 638 if (!pkt->isPrint()) { 639 // don't do DPRINTFs on PrintReq as it clutters up the output 640 DPRINTF(Bus, 641 "recvFunctional: packet src %s addr 0x%x cmd %s\n", 642 slavePorts[pkt->getSrc()]->name(), pkt->getAddr(), 643 pkt->cmdString()); 644 } 645 646 // forward to all snoopers but the source 647 forwardFunctional(pkt, pkt->getSrc()); 648 649 // there is no need to continue if the snooping has found what we 650 // were looking for and the packet is already a response 651 if (!pkt->isResponse()) { 652 int dest_id = findPort(pkt->getAddr()); 653 654 masterPorts[dest_id]->sendFunctional(pkt); 655 } 656} 657 658void 659Bus::recvFunctionalSnoop(PacketPtr pkt) 660{ 661 if (!pkt->isPrint()) { 662 // don't do DPRINTFs on PrintReq as it clutters up the output 663 DPRINTF(Bus, 664 "recvFunctionalSnoop: packet src %s addr 0x%x cmd %s\n", 665 masterPorts[pkt->getSrc()]->name(), pkt->getAddr(), 666 pkt->cmdString()); 667 } 668 669 // forward to all snoopers 670 forwardFunctional(pkt, Port::INVALID_PORT_ID); 671} 672 673void 674Bus::forwardFunctional(PacketPtr pkt, int exclude_slave_port_id) 675{ 676 for (SlavePortIter s = snoopPorts.begin(); s != snoopPorts.end(); ++s) { 677 SlavePort *p = *s; 678 // we could have gotten this request from a snooping master 679 // (corresponding to our own slave port that is also in 680 // snoopPorts) and should not send it back to where it came 681 // from 682 if (exclude_slave_port_id == Port::INVALID_PORT_ID || 683 p->getId() != exclude_slave_port_id) 684 p->sendFunctionalSnoop(pkt); 685 686 // if we get a response we are done 687 if (pkt->isResponse()) { 688 break; 689 } 690 } 691} 692 693/** Function called by the port when the bus is receiving a range change.*/ 694void 695Bus::recvRangeChange(Port::PortId id) 696{ 697 AddrRangeList ranges; 698 AddrRangeIter iter; 699 700 if (inRecvRangeChange.count(id)) 701 return; 702 inRecvRangeChange.insert(id); 703 704 DPRINTF(BusAddrRanges, "received RangeChange from device id %d\n", id); 705 706 clearPortCache(); 707 if (id == defaultPortId) { 708 defaultRange.clear(); 709 // Only try to update these ranges if the user set a default responder. 710 if (useDefaultRange) { 711 AddrRangeList ranges = 712 masterPorts[id]->getSlavePort().getAddrRanges(); 713 for(iter = ranges.begin(); iter != ranges.end(); iter++) { 714 defaultRange.push_back(*iter); 715 DPRINTF(BusAddrRanges, "Adding range %#llx - %#llx for default range\n", 716 iter->start, iter->end); 717 } 718 } 719 } else { 720 721 assert(id < masterPorts.size() && id >= 0); 722 MasterPort *port = masterPorts[id]; 723 724 // Clean out any previously existent ids 725 for (PortIter portIter = portMap.begin(); 726 portIter != portMap.end(); ) { 727 if (portIter->second == id) 728 portMap.erase(portIter++); 729 else 730 portIter++; 731 } 732 733 ranges = port->getSlavePort().getAddrRanges(); 734 735 for (iter = ranges.begin(); iter != ranges.end(); iter++) { 736 DPRINTF(BusAddrRanges, "Adding range %#llx - %#llx for id %d\n", 737 iter->start, iter->end, id); 738 if (portMap.insert(*iter, id) == portMap.end()) { 739 int conflict_id = portMap.find(*iter)->second; 740 fatal("%s has two ports with same range:\n\t%s\n\t%s\n", 741 name(), masterPorts[id]->getSlavePort().name(), 742 masterPorts[conflict_id]->getSlavePort().name()); 743 } 744 } 745 } 746 DPRINTF(BusAddrRanges, "port list has %d entries\n", portMap.size()); 747 748 // tell all our neighbouring master ports that our address range 749 // has changed 750 for (SlavePortConstIter p = slavePorts.begin(); p != slavePorts.end(); 751 ++p) 752 (*p)->sendRangeChange(); 753 754 inRecvRangeChange.erase(id); 755} 756 757AddrRangeList 758Bus::getAddrRanges(Port::PortId id) 759{ 760 AddrRangeList ranges; 761 762 DPRINTF(BusAddrRanges, "received address range request, returning:\n"); 763 764 for (AddrRangeIter dflt_iter = defaultRange.begin(); 765 dflt_iter != defaultRange.end(); dflt_iter++) { 766 ranges.push_back(*dflt_iter); 767 DPRINTF(BusAddrRanges, " -- Dflt: %#llx : %#llx\n",dflt_iter->start, 768 dflt_iter->end); 769 } 770 for (PortIter portIter = portMap.begin(); 771 portIter != portMap.end(); portIter++) { 772 bool subset = false; 773 for (AddrRangeIter dflt_iter = defaultRange.begin(); 774 dflt_iter != defaultRange.end(); dflt_iter++) { 775 if ((portIter->first.start < dflt_iter->start && 776 portIter->first.end >= dflt_iter->start) || 777 (portIter->first.start < dflt_iter->end && 778 portIter->first.end >= dflt_iter->end)) 779 fatal("Devices can not set ranges that itersect the default set\ 780 but are not a subset of the default set.\n"); 781 if (portIter->first.start >= dflt_iter->start && 782 portIter->first.end <= dflt_iter->end) { 783 subset = true; 784 DPRINTF(BusAddrRanges, " -- %#llx : %#llx is a SUBSET\n", 785 portIter->first.start, portIter->first.end); 786 } 787 } 788 if (portIter->second != id && !subset) { 789 ranges.push_back(portIter->first); 790 DPRINTF(BusAddrRanges, " -- %#llx : %#llx\n", 791 portIter->first.start, portIter->first.end); 792 } 793 } 794 795 return ranges; 796} 797 798bool 799Bus::isSnooping(Port::PortId id) const 800{ 801 // in essence, answer the question if there are snooping ports 802 return !snoopPorts.empty(); 803} 804 805unsigned 806Bus::findBlockSize(Port::PortId id) 807{ 808 if (cachedBlockSizeValid) 809 return cachedBlockSize; 810 811 unsigned max_bs = 0; 812 813 PortIter p_end = portMap.end(); 814 for (PortIter p_iter = portMap.begin(); p_iter != p_end; p_iter++) { 815 unsigned tmp_bs = masterPorts[p_iter->second]->peerBlockSize(); 816 if (tmp_bs > max_bs) 817 max_bs = tmp_bs; 818 } 819 820 for (SlavePortConstIter s = snoopPorts.begin(); s != snoopPorts.end(); 821 ++s) { 822 unsigned tmp_bs = (*s)->peerBlockSize(); 823 if (tmp_bs > max_bs) 824 max_bs = tmp_bs; 825 } 826 if (max_bs == 0) 827 max_bs = defaultBlockSize; 828 829 if (max_bs != 64) 830 warn_once("Blocksize found to not be 64... hmm... probably not.\n"); 831 cachedBlockSize = max_bs; 832 cachedBlockSizeValid = true; 833 return max_bs; 834} 835 836 837unsigned int 838Bus::drain(Event * de) 839{ 840 //We should check that we're not "doing" anything, and that noone is 841 //waiting. We might be idle but have someone waiting if the device we 842 //contacted for a retry didn't actually retry. 843 if (!retryList.empty() || (curTick() < tickNextIdle && 844 busIdleEvent.scheduled())) { 845 drainEvent = de; 846 return 1; 847 } 848 return 0; 849} 850 851void 852Bus::startup() 853{ 854 if (tickNextIdle < curTick()) 855 tickNextIdle = (curTick() / clock) * clock + clock; 856} 857 858Bus * 859BusParams::create() 860{ 861 return new Bus(this); 862} 863