src/mem/cache/cache_impl.hh

   1 /*
   2  * Copyright (c) 2002-2005 The Regents of The University of Michigan
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met: redistributions of source code must retain the above copyright
   8  * notice, this list of conditions and the following disclaimer;
   9  * redistributions in binary form must reproduce the above copyright
  10  * notice, this list of conditions and the following disclaimer in the
  11  * documentation and/or other materials provided with the distribution;
  12  * neither the name of the copyright holders nor the names of its
  13  * contributors may be used to endorse or promote products derived from
  14  * this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  17  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  19  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  20  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  21  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  *
  28  * Authors: Erik Hallnor
  29  *          Dave Greene
  30  *          Nathan Binkert
  31  */
  32
  33 /**
  34  * @file
  35  * Cache definitions.
  36  */
  37
  38 #include <assert.h>
  39 #include <math.h>
  40
  41 #include <cassert>
  42 #include <iostream>
  43 #include <string>
  44
  45 #include "sim/host.hh"
  46 #include "base/misc.hh"
  47 #include "cpu/smt.hh"
  48
  49 #include "mem/cache/cache.hh"
  50 #include "mem/cache/cache_blk.hh"
  51 #include "mem/cache/miss/mshr.hh"
  52 #include "mem/cache/prefetch/prefetcher.hh"
  53
  54 #include "sim/sim_exit.hh" // for SimExitEvent
  55
  56 template<class TagStore, class Buffering, class Coherence>
  57 bool
  58 Cache<TagStore,Buffering,Coherence>::
  59 doTimingAccess(Packet *pkt, CachePort *cachePort, bool isCpuSide)
  60 {
  61     if (isCpuSide)
  62     {
  63         if (pkt->isWrite() && (pkt->req->isLocked())) {
  64             pkt->req->setScResult(1);
  65         }
  66         access(pkt);
  67
  68     }
  69     else
  70     {
  71         if (pkt->isResponse())
  72             handleResponse(pkt);
  73         else {
  74             //Check if we should do the snoop
  75             if (pkt->flags & SNOOP_COMMIT)
  76                 snoop(pkt);
  77         }
  78     }
  79     return true;
  80 }
  81
  82 template<class TagStore, class Buffering, class Coherence>
  83 Tick
  84 Cache<TagStore,Buffering,Coherence>::
  85 doAtomicAccess(Packet *pkt, bool isCpuSide)
  86 {
  87     if (isCpuSide)
  88     {
  89         //Temporary solution to LL/SC
  90         if (pkt->isWrite() && (pkt->req->isLocked())) {
  91             pkt->req->setScResult(1);
  92         }
  93
  94         probe(pkt, true, NULL);
  95         //TEMP ALWAYS SUCCES FOR NOW
  96         pkt->result = Packet::Success;
  97     }
  98     else
  99     {
 100         if (pkt->isResponse())
 101             handleResponse(pkt);
 102         else
 103             return snoopProbe(pkt);
 104     }
 105     //Fix this timing info
 106     return hitLatency;
 107 }
 108
 109 template<class TagStore, class Buffering, class Coherence>
 110 void
 111 Cache<TagStore,Buffering,Coherence>::
 112 doFunctionalAccess(Packet *pkt, bool isCpuSide)
 113 {
 114     if (isCpuSide)
 115     {
 116         //TEMP USE CPU?THREAD 0 0
 117         pkt->req->setThreadContext(0,0);
 118
 119         //Temporary solution to LL/SC
 120         if (pkt->isWrite() && (pkt->req->isLocked())) {
 121             assert("Can't handle LL/SC on functional path\n");
 122         }
 123
 124         probe(pkt, false, memSidePort);
 125         //TEMP ALWAYS SUCCESFUL FOR NOW
 126         pkt->result = Packet::Success;
 127     }
 128     else
 129     {
 130             probe(pkt, false, cpuSidePort);
 131     }
 132 }
 133
 134 template<class TagStore, class Buffering, class Coherence>
 135 void
 136 Cache<TagStore,Buffering,Coherence>::
 137 recvStatusChange(Port::Status status, bool isCpuSide)
 138 {
 139
 140 }
 141
 142
 143 template<class TagStore, class Buffering, class Coherence>
 144 Cache<TagStore,Buffering,Coherence>::
 145 Cache(const std::string &_name,
 146       Cache<TagStore,Buffering,Coherence>::Params &params)
 147     : BaseCache(_name, params.baseParams),
 148       prefetchAccess(params.prefetchAccess),
 149       tags(params.tags), missQueue(params.missQueue),
 150       coherence(params.coherence), prefetcher(params.prefetcher),
 151       doCopy(params.doCopy), blockOnCopy(params.blockOnCopy),
 152       hitLatency(params.hitLatency)
 153 {
 154     tags->setCache(this);
 155     tags->setPrefetcher(prefetcher);
 156     missQueue->setCache(this);
 157     missQueue->setPrefetcher(prefetcher);
 158     coherence->setCache(this);
 159     prefetcher->setCache(this);
 160     prefetcher->setTags(tags);
 161     prefetcher->setBuffer(missQueue);
 162     invalidateReq = new Request((Addr) NULL, blkSize, 0);
 163     invalidatePkt = new Packet(invalidateReq, Packet::InvalidateReq, 0);
 164 }
 165
 166 template<class TagStore, class Buffering, class Coherence>
 167 void
 168 Cache<TagStore,Buffering,Coherence>::regStats()
 169 {
 170     BaseCache::regStats();
 171     tags->regStats(name());
 172     missQueue->regStats(name());
 173     coherence->regStats(name());
 174     prefetcher->regStats(name());
 175 }
 176
 177 template<class TagStore, class Buffering, class Coherence>
 178 bool
 179 Cache<TagStore,Buffering,Coherence>::access(PacketPtr &pkt)
 180 {
 181 //@todo Add back in MemDebug Calls
 182 //    MemDebug::cacheAccess(pkt);
 183     BlkType *blk = NULL;
 184     PacketList writebacks;
 185     int size = blkSize;
 186     int lat = hitLatency;
 187     if (prefetchAccess) {
 188         //We are determining prefetches on access stream, call prefetcher
 189         prefetcher->handleMiss(pkt, curTick);
 190     }
 191     if (!pkt->req->isUncacheable()) {
 192         blk = tags->handleAccess(pkt, lat, writebacks);
 193     } else {
 194         size = pkt->getSize();
 195     }
 196     // If this is a block size write/hint (WH64) allocate the block here
 197     // if the coherence protocol allows it.
 198     /** @todo make the fast write alloc (wh64) work with coherence. */
 199     /** @todo Do we want to do fast writes for writebacks as well? */
 200     if (!blk && pkt->getSize() >= blkSize && coherence->allowFastWrites() &&
 201         (pkt->cmd == Packet::WriteReq || pkt->cmd == Packet::WriteInvalidateReq) ) {
 202         // not outstanding misses, can do this
 203         MSHR* outstanding_miss = missQueue->findMSHR(pkt->getAddr());
 204         if (pkt->cmd == Packet::WriteInvalidateReq || !outstanding_miss) {
 205             if (outstanding_miss) {
 206                 warn("WriteInv doing a fastallocate"
 207                      "with an outstanding miss to the same address\n");
 208             }
 209             blk = tags->handleFill(NULL, pkt, BlkValid | BlkWritable,
 210                                    writebacks);
 211             ++fastWrites;
 212         }
 213     }
 214     while (!writebacks.empty()) {
 215         missQueue->doWriteback(writebacks.front());
 216         writebacks.pop_front();
 217     }
 218     DPRINTF(Cache, "%s %x %s blk_addr: %x\n", pkt->cmdString(),
 219             pkt->getAddr() & (((ULL(1))<<48)-1), (blk) ? "hit" : "miss",
 220             pkt->getAddr() & ~((Addr)blkSize - 1));
 221     if (blk) {
 222         // Hit
 223         hits[pkt->cmdToIndex()][0/*pkt->req->getThreadNum()*/]++;
 224         // clear dirty bit if write through
 225         if (pkt->needsResponse())
 226             respond(pkt, curTick+lat);
 227         if (pkt->cmd == Packet::Writeback) {
 228             //Signal that you can kill the pkt/req
 229             pkt->flags |= SATISFIED;
 230         }
 231         return true;
 232     }
 233
 234     // Miss
 235     if (!pkt->req->isUncacheable()) {
 236         misses[pkt->cmdToIndex()][0/*pkt->req->getThreadNum()*/]++;
 237         /** @todo Move miss count code into BaseCache */
 238         if (missCount) {
 239             --missCount;
 240             if (missCount == 0)
 241                 exitSimLoop("A cache reached the maximum miss count");
 242         }
 243     }
 244     missQueue->handleMiss(pkt, size, curTick + hitLatency);
 245 //    return MA_CACHE_MISS;
 246     return true;
 247 }
 248
 249
 250 template<class TagStore, class Buffering, class Coherence>
 251 Packet *
 252 Cache<TagStore,Buffering,Coherence>::getPacket()
 253 {
 254     assert(missQueue->havePending());
 255     Packet * pkt = missQueue->getPacket();
 256     if (pkt) {
 257         if (!pkt->req->isUncacheable()) {
 258             if (pkt->cmd == Packet::HardPFReq) misses[Packet::HardPFReq][0/*pkt->req->getThreadNum()*/]++;
 259             BlkType *blk = tags->findBlock(pkt);
 260             Packet::Command cmd = coherence->getBusCmd(pkt->cmd,
 261                                               (blk)? blk->status : 0);
 262             missQueue->setBusCmd(pkt, cmd);
 263         }
 264     }
 265
 266     assert(!doMasterRequest() || missQueue->havePending());
 267     assert(!pkt || pkt->time <= curTick);
 268     return pkt;
 269 }
 270
 271 template<class TagStore, class Buffering, class Coherence>
 272 void
 273 Cache<TagStore,Buffering,Coherence>::sendResult(PacketPtr &pkt, MSHR* mshr, bool success)
 274 {
 275     if (success && !(pkt && (pkt->flags & NACKED_LINE))) {
 276         missQueue->markInService(mshr->pkt, mshr);
 277         //Temp Hack for UPGRADES
 278         if (mshr->pkt->cmd == Packet::UpgradeReq) {
 279             assert(pkt);  //Upgrades need to be fixed
 280             pkt->flags &= ~CACHE_LINE_FILL;
 281             BlkType *blk = tags->findBlock(pkt);
 282             CacheBlk::State old_state = (blk) ? blk->status : 0;
 283             CacheBlk::State new_state = coherence->getNewState(pkt,old_state);
 284             if (old_state != new_state)
 285                 DPRINTF(Cache, "Block for blk addr %x moving from state %i to %i\n",
 286                         pkt->getAddr() & (((ULL(1))<<48)-1), old_state, new_state);
 287             //Set the state on the upgrade
 288             memcpy(pkt->getPtr<uint8_t>(), blk->data, blkSize);
 289             PacketList writebacks;
 290             tags->handleFill(blk, mshr, new_state, writebacks, pkt);
 291             assert(writebacks.empty());
 292             missQueue->handleResponse(pkt, curTick + hitLatency);
 293         }
 294     } else if (pkt && !pkt->req->isUncacheable()) {
 295         pkt->flags &= ~NACKED_LINE;
 296         pkt->flags &= ~SATISFIED;
 297         pkt->flags &= ~SNOOP_COMMIT;
 298         missQueue->restoreOrigCmd(pkt);
 299     }
 300 }
 301
 302 template<class TagStore, class Buffering, class Coherence>
 303 void
 304 Cache<TagStore,Buffering,Coherence>::handleResponse(Packet * &pkt)
 305 {
 306     BlkType *blk = NULL;
 307     if (pkt->senderState) {
 308         //Delete temp copy in MSHR, restore it.
 309         delete ((MSHR*)pkt->senderState)->pkt;
 310         ((MSHR*)pkt->senderState)->pkt = pkt;
 311         if (pkt->result == Packet::Nacked) {
 312             //pkt->reinitFromRequest();
 313             warn("NACKs from devices not connected to the same bus not implemented\n");
 314             return;
 315         }
 316         if (pkt->result == Packet::BadAddress) {
 317             //Make the response a Bad address and send it
 318         }
 319 //      MemDebug::cacheResponse(pkt);
 320         DPRINTF(Cache, "Handling reponse to %x, blk addr: %x\n",pkt->getAddr(),
 321                 pkt->getAddr() & (((ULL(1))<<48)-1));
 322
 323         if (pkt->isCacheFill() && !pkt->isNoAllocate()) {
 324             blk = tags->findBlock(pkt);
 325             CacheBlk::State old_state = (blk) ? blk->status : 0;
 326             PacketList writebacks;
 327             CacheBlk::State new_state = coherence->getNewState(pkt,old_state);
 328             if (old_state != new_state)
 329                 DPRINTF(Cache, "Block for blk addr %x moving from state %i to %i\n",
 330                         pkt->getAddr() & (((ULL(1))<<48)-1), old_state, new_state);
 331             blk = tags->handleFill(blk, (MSHR*)pkt->senderState,
 332                                    new_state, writebacks, pkt);
 333             while (!writebacks.empty()) {
 334                     missQueue->doWriteback(writebacks.front());
 335                     writebacks.pop_front();
 336             }
 337         }
 338         missQueue->handleResponse(pkt, curTick + hitLatency);
 339     }
 340 }
 341
 342 template<class TagStore, class Buffering, class Coherence>
 343 void
 344 Cache<TagStore,Buffering,Coherence>::pseudoFill(Addr addr)
 345 {
 346     // Need to temporarily move this blk into MSHRs
 347     MSHR *mshr = missQueue->allocateTargetList(addr);
 348     int lat;
 349     PacketList dummy;
 350     // Read the data into the mshr
 351     BlkType *blk = tags->handleAccess(mshr->pkt, lat, dummy, false);
 352     assert(dummy.empty());
 353     assert(mshr->pkt->flags & SATISFIED);
 354     // can overload order since it isn't used on non pending blocks
 355     mshr->order = blk->status;
 356     // temporarily remove the block from the cache.
 357     tags->invalidateBlk(addr);
 358 }
 359
 360 template<class TagStore, class Buffering, class Coherence>
 361 void
 362 Cache<TagStore,Buffering,Coherence>::pseudoFill(MSHR *mshr)
 363 {
 364     // Need to temporarily move this blk into MSHRs
 365     assert(mshr->pkt->cmd == Packet::ReadReq);
 366     int lat;
 367     PacketList dummy;
 368     // Read the data into the mshr
 369     BlkType *blk = tags->handleAccess(mshr->pkt, lat, dummy, false);
 370     assert(dummy.empty());
 371     assert(mshr->pkt->flags & SATISFIED);
 372     // can overload order since it isn't used on non pending blocks
 373     mshr->order = blk->status;
 374     // temporarily remove the block from the cache.
 375     tags->invalidateBlk(mshr->pkt->getAddr());
 376 }
 377
 378
 379 template<class TagStore, class Buffering, class Coherence>
 380 Packet *
 381 Cache<TagStore,Buffering,Coherence>::getCoherencePacket()
 382 {
 383     return coherence->getPacket();
 384 }
 385
 386 template<class TagStore, class Buffering, class Coherence>
 387 void
 388 Cache<TagStore,Buffering,Coherence>::sendCoherenceResult(Packet* &pkt,
 389                                                          MSHR *cshr,
 390                                                          bool success)
 391 {
 392     coherence->sendResult(pkt, cshr, success);
 393 }
 394
 395
 396 template<class TagStore, class Buffering, class Coherence>
 397 void
 398 Cache<TagStore,Buffering,Coherence>::snoop(Packet * &pkt)
 399 {
 400     if (pkt->req->isUncacheable()) {
 401         //Can't get a hit on an uncacheable address
 402         //Revisit this for multi level coherence
 403         return;
 404     }
 405     Addr blk_addr = pkt->getAddr() & ~(Addr(blkSize-1));
 406     BlkType *blk = tags->findBlock(pkt);
 407     MSHR *mshr = missQueue->findMSHR(blk_addr);
 408     if (coherence->hasProtocol()) { //@todo Move this into handle bus req
 409         //If we find an mshr, and it is in service, we need to NACK or invalidate
 410         if (mshr) {
 411             if (mshr->inService) {
 412                 if ((mshr->pkt->isInvalidate() || !mshr->pkt->isCacheFill())
 413                     && (pkt->cmd != Packet::InvalidateReq && pkt->cmd != Packet::WriteInvalidateReq)) {
 414                     //If the outstanding request was an invalidate (upgrade,readex,..)
 415                     //Then we need to ACK the request until we get the data
 416                     //Also NACK if the outstanding request is not a cachefill (writeback)
 417                     assert(!(pkt->flags & SATISFIED));
 418                     pkt->flags |= SATISFIED;
 419                     pkt->flags |= NACKED_LINE;
 420                     ///@todo NACK's from other levels
 421                     //warn("NACKs from devices not connected to the same bus not implemented\n");
 422                     //respondToSnoop(pkt, curTick + hitLatency);
 423                     return;
 424                 }
 425                 else {
 426                     //The supplier will be someone else, because we are waiting for
 427                     //the data.  This should cause this cache to be forced to go to
 428                     //the shared state, not the exclusive even though the shared line
 429                     //won't be asserted.  But for now we will just invlidate ourselves
 430                     //and allow the other cache to go into the exclusive state.
 431                     //@todo Make it so a read to a pending read doesn't invalidate.
 432                     //@todo Make it so that a read to a pending read can't be exclusive now.
 433
 434                     //Set the address so find match works
 435                     //panic("Don't have invalidates yet\n");
 436                     invalidatePkt->addrOverride(pkt->getAddr());
 437
 438                     //Append the invalidate on
 439                     missQueue->addTarget(mshr,invalidatePkt);
 440                     DPRINTF(Cache, "Appending Invalidate to blk_addr: %x\n", pkt->getAddr() & (((ULL(1))<<48)-1));
 441                     return;
 442                 }
 443             }
 444         }
 445         //We also need to check the writeback buffers and handle those
 446         std::vector<MSHR *> writebacks;
 447         if (missQueue->findWrites(blk_addr, writebacks)) {
 448             DPRINTF(Cache, "Snoop hit in writeback to blk_addr: %x\n", pkt->getAddr() & (((ULL(1))<<48)-1));
 449
 450             //Look through writebacks for any non-uncachable writes, use that
 451             for (int i=0; i<writebacks.size(); i++) {
 452                 mshr = writebacks[i];
 453
 454                 if (!mshr->pkt->req->isUncacheable()) {
 455                     if (pkt->isRead()) {
 456                         //Only Upgrades don't get here
 457                         //Supply the data
 458                         assert(!(pkt->flags & SATISFIED));
 459                         pkt->flags |= SATISFIED;
 460
 461                         //If we are in an exclusive protocol, make it ask again
 462                         //to get write permissions (upgrade), signal shared
 463                         pkt->flags |= SHARED_LINE;
 464
 465                         assert(pkt->isRead());
 466                         Addr offset = pkt->getAddr() & (blkSize - 1);
 467                         assert(offset < blkSize);
 468                         assert(pkt->getSize() <= blkSize);
 469                         assert(offset + pkt->getSize() <=blkSize);
 470                         memcpy(pkt->getPtr<uint8_t>(), mshr->pkt->getPtr<uint8_t>() + offset, pkt->getSize());
 471
 472                         respondToSnoop(pkt, curTick + hitLatency);
 473                     }
 474
 475                     if (pkt->isInvalidate()) {
 476                         //This must be an upgrade or other cache will take ownership
 477                         missQueue->markInService(mshr->pkt, mshr);
 478                     }
 479                     return;
 480                 }
 481             }
 482         }
 483     }
 484     CacheBlk::State new_state;
 485     bool satisfy = coherence->handleBusRequest(pkt,blk,mshr, new_state);
 486     if (satisfy) {
 487         DPRINTF(Cache, "Cache snooped a %s request for addr %x and now supplying data,"
 488                 "new state is %i\n",
 489                 pkt->cmdString(), blk_addr, new_state);
 490
 491         tags->handleSnoop(blk, new_state, pkt);
 492         respondToSnoop(pkt, curTick + hitLatency);
 493         return;
 494     }
 495     if (blk) DPRINTF(Cache, "Cache snooped a %s request for addr %x, new state is %i\n",
 496                      pkt->cmdString(), blk_addr, new_state);
 497     tags->handleSnoop(blk, new_state);
 498 }
 499
 500 template<class TagStore, class Buffering, class Coherence>
 501 void
 502 Cache<TagStore,Buffering,Coherence>::snoopResponse(Packet * &pkt)
 503 {
 504     //Need to handle the response, if NACKED
 505     if (pkt->flags & NACKED_LINE) {
 506         //Need to mark it as not in service, and retry for bus
 507         assert(0); //Yeah, we saw a NACK come through
 508
 509         //For now this should never get called, we return false when we see a NACK
 510         //instead, by doing this we allow the bus_blocked mechanism to handle the retry
 511         //For now it retrys in just 2 cycles, need to figure out how to change that
 512         //Eventually we will want to also have success come in as a parameter
 513         //Need to make sure that we handle the functionality that happens on successufl
 514         //return of the sendAddr function
 515     }
 516 }
 517
 518 template<class TagStore, class Buffering, class Coherence>
 519 void
 520 Cache<TagStore,Buffering,Coherence>::invalidateBlk(Addr addr)
 521 {
 522     tags->invalidateBlk(addr);
 523 }
 524
 525
 526 /**
 527  * @todo Fix to not assume write allocate
 528  */
 529 template<class TagStore, class Buffering, class Coherence>
 530 Tick
 531 Cache<TagStore,Buffering,Coherence>::probe(Packet * &pkt, bool update, CachePort* otherSidePort)
 532 {
 533 //    MemDebug::cacheProbe(pkt);
 534     if (!pkt->req->isUncacheable()) {
 535         if (pkt->isInvalidate() && !pkt->isRead()
 536             && !pkt->isWrite()) {
 537             //Upgrade or Invalidate, satisfy it, don't forward
 538             DPRINTF(Cache, "%s %x ? blk_addr: %x\n", pkt->cmdString(),
 539                     pkt->getAddr() & (((ULL(1))<<48)-1),
 540                     pkt->getAddr() & ~((Addr)blkSize - 1));
 541             pkt->flags |= SATISFIED;
 542             return 0;
 543         }
 544     }
 545
 546     PacketList writebacks;
 547     int lat;
 548     BlkType *blk = tags->handleAccess(pkt, lat, writebacks, update);
 549
 550     DPRINTF(Cache, "%s %x %s blk_addr: %x\n", pkt->cmdString(),
 551             pkt->getAddr() & (((ULL(1))<<48)-1), (blk) ? "hit" : "miss",
 552             pkt->getAddr() & ~((Addr)blkSize - 1));
 553
 554     if (!blk) {
 555         // Need to check for outstanding misses and writes
 556         Addr blk_addr = pkt->getAddr() & ~(blkSize - 1);
 557
 558         // There can only be one matching outstanding miss.
 559         MSHR* mshr = missQueue->findMSHR(blk_addr);
 560
 561         // There can be many matching outstanding writes.
 562         std::vector<MSHR*> writes;
 563         missQueue->findWrites(blk_addr, writes);
 564
 565         if (!update) {
 566                 otherSidePort->sendFunctional(pkt);
 567
 568             // Check for data in MSHR and writebuffer.
 569             if (mshr) {
 570                 warn("Found outstanding miss on an non-update probe");
 571                 MSHR::TargetList *targets = mshr->getTargetList();
 572                 MSHR::TargetList::iterator i = targets->begin();
 573                 MSHR::TargetList::iterator end = targets->end();
 574                 for (; i != end; ++i) {
 575                     Packet * target = *i;
 576                     // If the target contains data, and it overlaps the
 577                     // probed request, need to update data
 578                     if (target->isWrite() && target->intersect(pkt)) {
 579                         uint8_t* pkt_data;
 580                         uint8_t* write_data;
 581                         int data_size;
 582                         if (target->getAddr() < pkt->getAddr()) {
 583                             int offset = pkt->getAddr() - target->getAddr();
 584                             pkt_data = pkt->getPtr<uint8_t>();
 585                             write_data = target->getPtr<uint8_t>() + offset;
 586                             data_size = target->getSize() - offset;
 587                             assert(data_size > 0);
 588                             if (data_size > pkt->getSize())
 589                                 data_size = pkt->getSize();
 590                         } else {
 591                             int offset = target->getAddr() - pkt->getAddr();
 592                             pkt_data = pkt->getPtr<uint8_t>() + offset;
 593                             write_data = target->getPtr<uint8_t>();
 594                             data_size = pkt->getSize() - offset;
 595                             assert(data_size > pkt->getSize());
 596                             if (data_size > target->getSize())
 597                                 data_size = target->getSize();
 598                         }
 599
 600                         if (pkt->isWrite()) {
 601                             memcpy(pkt_data, write_data, data_size);
 602                         } else {
 603                             memcpy(write_data, pkt_data, data_size);
 604                         }
 605                     }
 606                 }
 607             }
 608             for (int i = 0; i < writes.size(); ++i) {
 609                 Packet * write = writes[i]->pkt;
 610                 if (write->intersect(pkt)) {
 611                     warn("Found outstanding write on an non-update probe");
 612                     uint8_t* pkt_data;
 613                     uint8_t* write_data;
 614                     int data_size;
 615                     if (write->getAddr() < pkt->getAddr()) {
 616                         int offset = pkt->getAddr() - write->getAddr();
 617                         pkt_data = pkt->getPtr<uint8_t>();
 618                         write_data = write->getPtr<uint8_t>() + offset;
 619                         data_size = write->getSize() - offset;
 620                         assert(data_size > 0);
 621                         if (data_size > pkt->getSize())
 622                             data_size = pkt->getSize();
 623                     } else {
 624                         int offset = write->getAddr() - pkt->getAddr();
 625                         pkt_data = pkt->getPtr<uint8_t>() + offset;
 626                         write_data = write->getPtr<uint8_t>();
 627                         data_size = pkt->getSize() - offset;
 628                         assert(data_size > pkt->getSize());
 629                         if (data_size > write->getSize())
 630                             data_size = write->getSize();
 631                     }
 632
 633                     if (pkt->isWrite()) {
 634                         memcpy(pkt_data, write_data, data_size);
 635                     } else {
 636                         memcpy(write_data, pkt_data, data_size);
 637                     }
 638
 639                 }
 640             }
 641             return 0;
 642         } else {
 643             // update the cache state and statistics
 644             if (mshr || !writes.empty()){
 645                 // Can't handle it, return pktuest unsatisfied.
 646                 panic("Atomic access ran into outstanding MSHR's or WB's!");
 647             }
 648             if (!pkt->req->isUncacheable()) {
 649                 // Fetch the cache block to fill
 650                 BlkType *blk = tags->findBlock(pkt);
 651                 Packet::Command temp_cmd = coherence->getBusCmd(pkt->cmd,
 652                                                    (blk)? blk->status : 0);
 653
 654                 Packet * busPkt = new Packet(pkt->req,temp_cmd, -1, blkSize);
 655
 656                 busPkt->allocate();
 657
 658                 busPkt->time = curTick;
 659
 660                 DPRINTF(Cache, "Sending a atomic %s for %x blk_addr: %x\n",
 661                         busPkt->cmdString(),
 662                         busPkt->getAddr() & (((ULL(1))<<48)-1),
 663                         busPkt->getAddr() & ~((Addr)blkSize - 1));
 664
 665                 lat = memSidePort->sendAtomic(busPkt);
 666
 667                 //Be sure to flip the response to a request for coherence
 668                 if (busPkt->needsResponse()) {
 669                     busPkt->makeAtomicResponse();
 670                 }
 671
 672 /*              if (!(busPkt->flags & SATISFIED)) {
 673                     // blocked at a higher level, just return
 674                     return 0;
 675                 }
 676
 677 */              misses[pkt->cmdToIndex()][0/*pkt->req->getThreadNum()*/]++;
 678
 679                 CacheBlk::State old_state = (blk) ? blk->status : 0;
 680                 CacheBlk::State new_state = coherence->getNewState(busPkt, old_state);
 681                     DPRINTF(Cache, "Receive response:%s for blk addr %x in state %i\n",
 682                             busPkt->cmdString(),
 683                             busPkt->getAddr() & (((ULL(1))<<48)-1), old_state);
 684                 if (old_state != new_state)
 685                     DPRINTF(Cache, "Block for blk addr %x moving from state %i to %i\n",
 686                             busPkt->getAddr() & (((ULL(1))<<48)-1), old_state, new_state);
 687
 688                 tags->handleFill(blk, busPkt,
 689                                  new_state,
 690                                  writebacks, pkt);
 691                 //Free the packet
 692                 delete busPkt;
 693
 694                 // Handle writebacks if needed
 695                 while (!writebacks.empty()){
 696                     Packet *wbPkt = writebacks.front();
 697                     memSidePort->sendAtomic(wbPkt);
 698                     writebacks.pop_front();
 699                     delete wbPkt;
 700                 }
 701                 return lat + hitLatency;
 702             } else {
 703                 return memSidePort->sendAtomic(pkt);
 704             }
 705         }
 706     } else {
 707         // There was a cache hit.
 708         // Handle writebacks if needed
 709         while (!writebacks.empty()){
 710             memSidePort->sendAtomic(writebacks.front());
 711             writebacks.pop_front();
 712         }
 713
 714         if (update) {
 715             hits[pkt->cmdToIndex()][0/*pkt->req->getThreadNum()*/]++;
 716         } else if (pkt->isWrite()) {
 717             // Still need to change data in all locations.
 718             otherSidePort->sendFunctional(pkt);
 719         }
 720         return hitLatency;
 721     }
 722     fatal("Probe not handled.\n");
 723     return 0;
 724 }
 725
 726 template<class TagStore, class Buffering, class Coherence>
 727 Tick
 728 Cache<TagStore,Buffering,Coherence>::snoopProbe(PacketPtr &pkt)
 729 {
 730         Addr blk_addr = pkt->getAddr() & ~(Addr(blkSize-1));
 731         BlkType *blk = tags->findBlock(pkt);
 732         MSHR *mshr = missQueue->findMSHR(blk_addr);
 733         CacheBlk::State new_state = 0;
 734         bool satisfy = coherence->handleBusRequest(pkt,blk,mshr, new_state);
 735         if (satisfy) {
 736             DPRINTF(Cache, "Cache snooped a %s request for addr %x and now supplying data,"
 737                     "new state is %i\n",
 738                     pkt->cmdString(), blk_addr, new_state);
 739
 740             tags->handleSnoop(blk, new_state, pkt);
 741             return hitLatency;
 742         }
 743         if (blk) DPRINTF(Cache, "Cache snooped a %s request for addr %x, new state is %i\n",
 744                      pkt->cmdString(), blk_addr, new_state);
 745         tags->handleSnoop(blk, new_state);
 746         return 0;
 747 }
 748