src/mem/cache/base_cache.cc

   1 /*
   2  * Copyright (c) 2003-2005 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  */
  30
  31 /**
  32  * @file
  33  * Definition of BaseCache functions.
  34  */
  35
  36 #include "cpu/base.hh"
  37 #include "cpu/smt.hh"
  38 #include "mem/cache/base_cache.hh"
  39 #include "mem/cache/miss/mshr.hh"
  40
  41 using namespace std;
  42
  43 BaseCache::CachePort::CachePort(const std::string &_name, BaseCache *_cache,
  44                                 bool _isCpuSide)
  45     : Port(_name, _cache), cache(_cache), isCpuSide(_isCpuSide)
  46 {
  47     blocked = false;
  48     waitingOnRetry = false;
  49     //Start ports at null if more than one is created we should panic
  50     //cpuSidePort = NULL;
  51     //memSidePort = NULL;
  52 }
  53
  54 void
  55 BaseCache::CachePort::recvStatusChange(Port::Status status)
  56 {
  57     cache->recvStatusChange(status, isCpuSide);
  58 }
  59
  60 void
  61 BaseCache::CachePort::getDeviceAddressRanges(AddrRangeList &resp,
  62                                        AddrRangeList &snoop)
  63 {
  64     cache->getAddressRanges(resp, snoop, isCpuSide);
  65 }
  66
  67 int
  68 BaseCache::CachePort::deviceBlockSize()
  69 {
  70     return cache->getBlockSize();
  71 }
  72
  73 bool
  74 BaseCache::CachePort::recvTiming(PacketPtr pkt)
  75 {
  76     if (isCpuSide
  77         && !pkt->req->isUncacheable()
  78         && pkt->isInvalidate()
  79         && !pkt->isRead() && !pkt->isWrite()) {
  80         //Upgrade or Invalidate
  81         //Look into what happens if two slave caches on bus
  82         DPRINTF(Cache, "%s %x ?\n", pkt->cmdString(), pkt->getAddr());
  83
  84         assert(!(pkt->flags & SATISFIED));
  85         pkt->flags |= SATISFIED;
  86         //Invalidates/Upgrades need no response if they get the bus
  87         return true;
  88     }
  89
  90     if (pkt->isRequest() && blocked)
  91     {
  92         DPRINTF(Cache,"Scheduling a retry while blocked\n");
  93         mustSendRetry = true;
  94         return false;
  95     }
  96     return cache->doTimingAccess(pkt, this, isCpuSide);
  97 }
  98
  99 Tick
 100 BaseCache::CachePort::recvAtomic(PacketPtr pkt)
 101 {
 102     return cache->doAtomicAccess(pkt, isCpuSide);
 103 }
 104
 105 void
 106 BaseCache::CachePort::recvFunctional(PacketPtr pkt)
 107 {
 108     //Check storage here first
 109     list<PacketPtr>::iterator i = drainList.begin();
 110     list<PacketPtr>::iterator end = drainList.end();
 111     for (; i != end; ++i) {
 112         PacketPtr target = *i;
 113         // If the target contains data, and it overlaps the
 114         // probed request, need to update data
 115         if (target->intersect(pkt)) {
 116             fixPacket(pkt, target);
 117         }
 118     }
 119     cache->doFunctionalAccess(pkt, isCpuSide);
 120 }
 121
 122 void
 123 BaseCache::CachePort::recvRetry()
 124 {
 125     PacketPtr pkt;
 126     assert(waitingOnRetry);
 127     if (!drainList.empty()) {
 128         DPRINTF(CachePort, "%s attempting to send a retry for response\n", name());
 129         //We have some responses to drain first
 130         if (sendTiming(drainList.front())) {
 131             DPRINTF(CachePort, "%s sucessful in sending a retry for response\n", name());
 132             drainList.pop_front();
 133             if (!drainList.empty() ||
 134                 !isCpuSide && cache->doMasterRequest() ||
 135                 isCpuSide && cache->doSlaveRequest()) {
 136
 137                 DPRINTF(CachePort, "%s has more responses/requests\n", name());
 138                 BaseCache::CacheEvent * reqCpu = new BaseCache::CacheEvent(this);
 139                 reqCpu->schedule(curTick + 1);
 140             }
 141             waitingOnRetry = false;
 142         }
 143     }
 144     else if (!isCpuSide)
 145     {
 146         DPRINTF(CachePort, "%s attempting to send a retry for MSHR\n", name());
 147         if (!cache->doMasterRequest()) {
 148             //This can happen if I am the owner of a block and see an upgrade
 149             //while the block was in my WB Buffers.  I just remove the
 150             //wb and de-assert the masterRequest
 151             waitingOnRetry = false;
 152             return;
 153         }
 154         pkt = cache->getPacket();
 155         MSHR* mshr = (MSHR*) pkt->senderState;
 156         //Copy the packet, it may be modified/destroyed elsewhere
 157         PacketPtr copyPkt = new Packet(*pkt);
 158         copyPkt->dataStatic<uint8_t>(pkt->getPtr<uint8_t>());
 159         mshr->pkt = copyPkt;
 160
 161         bool success = sendTiming(pkt);
 162         DPRINTF(Cache, "Address %x was %s in sending the timing request\n",
 163                 pkt->getAddr(), success ? "succesful" : "unsuccesful");
 164
 165         waitingOnRetry = !success;
 166         if (waitingOnRetry) {
 167             DPRINTF(CachePort, "%s now waiting on a retry\n", name());
 168         }
 169
 170         cache->sendResult(pkt, mshr, success);
 171
 172         if (success && cache->doMasterRequest())
 173         {
 174             DPRINTF(CachePort, "%s has more requests\n", name());
 175             //Still more to issue, rerequest in 1 cycle
 176             BaseCache::CacheEvent * reqCpu = new BaseCache::CacheEvent(this);
 177             reqCpu->schedule(curTick + 1);
 178         }
 179     }
 180     else
 181     {
 182         assert(cache->doSlaveRequest());
 183         //pkt = cache->getCoherencePacket();
 184         //We save the packet, no reordering on CSHRS
 185         pkt = cache->getCoherencePacket();
 186         MSHR* cshr = (MSHR*)pkt->senderState;
 187         bool success = sendTiming(pkt);
 188         cache->sendCoherenceResult(pkt, cshr, success);
 189         waitingOnRetry = !success;
 190         if (success && cache->doSlaveRequest())
 191         {
 192             DPRINTF(CachePort, "%s has more requests\n", name());
 193             //Still more to issue, rerequest in 1 cycle
 194             BaseCache::CacheEvent * reqCpu = new BaseCache::CacheEvent(this);
 195             reqCpu->schedule(curTick + 1);
 196         }
 197     }
 198     if (waitingOnRetry) DPRINTF(CachePort, "%s STILL Waiting on retry\n", name());
 199     else DPRINTF(CachePort, "%s no longer waiting on retry\n", name());
 200     return;
 201 }
 202 void
 203 BaseCache::CachePort::setBlocked()
 204 {
 205     assert(!blocked);
 206     DPRINTF(Cache, "Cache Blocking\n");
 207     blocked = true;
 208     //Clear the retry flag
 209     mustSendRetry = false;
 210 }
 211
 212 void
 213 BaseCache::CachePort::clearBlocked()
 214 {
 215     assert(blocked);
 216     DPRINTF(Cache, "Cache Unblocking\n");
 217     blocked = false;
 218     if (mustSendRetry)
 219     {
 220         DPRINTF(Cache, "Cache Sending Retry\n");
 221         mustSendRetry = false;
 222         sendRetry();
 223     }
 224 }
 225
 226 BaseCache::CacheEvent::CacheEvent(CachePort *_cachePort)
 227     : Event(&mainEventQueue, CPU_Tick_Pri), cachePort(_cachePort)
 228 {
 229     this->setFlags(AutoDelete);
 230     pkt = NULL;
 231 }
 232
 233 BaseCache::CacheEvent::CacheEvent(CachePort *_cachePort, PacketPtr _pkt)
 234     : Event(&mainEventQueue, CPU_Tick_Pri), cachePort(_cachePort), pkt(_pkt)
 235 {
 236     this->setFlags(AutoDelete);
 237 }
 238
 239 void
 240 BaseCache::CacheEvent::process()
 241 {
 242     if (!pkt)
 243     {
 244         if (cachePort->waitingOnRetry) return;
 245        //We have some responses to drain first
 246         if (!cachePort->drainList.empty()) {
 247             DPRINTF(CachePort, "%s trying to drain a response\n", cachePort->name());
 248             if (cachePort->sendTiming(cachePort->drainList.front())) {
 249                 DPRINTF(CachePort, "%s drains a response succesfully\n", cachePort->name());
 250                 cachePort->drainList.pop_front();
 251                 if (!cachePort->drainList.empty() ||
 252                     !cachePort->isCpuSide && cachePort->cache->doMasterRequest() ||
 253                     cachePort->isCpuSide && cachePort->cache->doSlaveRequest()) {
 254
 255                     DPRINTF(CachePort, "%s still has outstanding bus reqs\n", cachePort->name());
 256                     this->schedule(curTick + 1);
 257                 }
 258             }
 259             else {
 260                 cachePort->waitingOnRetry = true;
 261                 DPRINTF(CachePort, "%s now waiting on a retry\n", cachePort->name());
 262             }
 263         }
 264         else if (!cachePort->isCpuSide)
 265         {            //MSHR
 266             DPRINTF(CachePort, "%s trying to send a MSHR request\n", cachePort->name());
 267             if (!cachePort->cache->doMasterRequest()) {
 268                 //This can happen if I am the owner of a block and see an upgrade
 269                 //while the block was in my WB Buffers.  I just remove the
 270                 //wb and de-assert the masterRequest
 271                 return;
 272             }
 273
 274             pkt = cachePort->cache->getPacket();
 275             MSHR* mshr = (MSHR*) pkt->senderState;
 276             //Copy the packet, it may be modified/destroyed elsewhere
 277             PacketPtr copyPkt = new Packet(*pkt);
 278             copyPkt->dataStatic<uint8_t>(pkt->getPtr<uint8_t>());
 279             mshr->pkt = copyPkt;
 280
 281             bool success = cachePort->sendTiming(pkt);
 282             DPRINTF(Cache, "Address %x was %s in sending the timing request\n",
 283                     pkt->getAddr(), success ? "succesful" : "unsuccesful");
 284
 285             cachePort->waitingOnRetry = !success;
 286             if (cachePort->waitingOnRetry) {
 287                 DPRINTF(CachePort, "%s now waiting on a retry\n", cachePort->name());
 288             }
 289
 290             cachePort->cache->sendResult(pkt, mshr, success);
 291             if (success && cachePort->cache->doMasterRequest())
 292             {
 293                 DPRINTF(CachePort, "%s still more MSHR requests to send\n",
 294                         cachePort->name());
 295                 //Still more to issue, rerequest in 1 cycle
 296                 pkt = NULL;
 297                 this->schedule(curTick+1);
 298             }
 299         }
 300         else
 301         {
 302             //CSHR
 303             assert(cachePort->cache->doSlaveRequest());
 304             pkt = cachePort->cache->getCoherencePacket();
 305             MSHR* cshr = (MSHR*) pkt->senderState;
 306             bool success = cachePort->sendTiming(pkt);
 307             cachePort->cache->sendCoherenceResult(pkt, cshr, success);
 308             cachePort->waitingOnRetry = !success;
 309             if (cachePort->waitingOnRetry)
 310                 DPRINTF(CachePort, "%s now waiting on a retry\n", cachePort->name());
 311             if (success && cachePort->cache->doSlaveRequest())
 312             {
 313                 DPRINTF(CachePort, "%s still more CSHR requests to send\n",
 314                         cachePort->name());
 315                 //Still more to issue, rerequest in 1 cycle
 316                 pkt = NULL;
 317                 this->schedule(curTick+1);
 318             }
 319         }
 320         return;
 321     }
 322     //Response
 323     //Know the packet to send
 324     if (pkt->flags & NACKED_LINE)
 325         pkt->result = Packet::Nacked;
 326     else
 327         pkt->result = Packet::Success;
 328     pkt->makeTimingResponse();
 329     DPRINTF(CachePort, "%s attempting to send a response\n", cachePort->name());
 330     if (!cachePort->drainList.empty() || cachePort->waitingOnRetry) {
 331         //Already have a list, just append
 332         cachePort->drainList.push_back(pkt);
 333         DPRINTF(CachePort, "%s appending response onto drain list\n", cachePort->name());
 334     }
 335     else if (!cachePort->sendTiming(pkt)) {
 336         //It failed, save it to list of drain events
 337         DPRINTF(CachePort, "%s now waiting for a retry\n", cachePort->name());
 338         cachePort->drainList.push_back(pkt);
 339         cachePort->waitingOnRetry = true;
 340     }
 341 }
 342
 343 const char *
 344 BaseCache::CacheEvent::description()
 345 {
 346     return "timing event\n";
 347 }
 348
 349 Port*
 350 BaseCache::getPort(const std::string &if_name, int idx)
 351 {
 352     if (if_name == "")
 353     {
 354         if(cpuSidePort == NULL)
 355             cpuSidePort = new CachePort(name() + "-cpu_side_port", this, true);
 356         return cpuSidePort;
 357     }
 358     else if (if_name == "functional")
 359     {
 360         return new CachePort(name() + "-cpu_side_port", this, true);
 361     }
 362     else if (if_name == "cpu_side")
 363     {
 364         if(cpuSidePort == NULL)
 365             cpuSidePort = new CachePort(name() + "-cpu_side_port", this, true);
 366         return cpuSidePort;
 367     }
 368     else if (if_name == "mem_side")
 369     {
 370         if (memSidePort != NULL)
 371             panic("Already have a mem side for this cache\n");
 372         memSidePort = new CachePort(name() + "-mem_side_port", this, false);
 373         return memSidePort;
 374     }
 375     else panic("Port name %s unrecognized\n", if_name);
 376 }
 377
 378 void
 379 BaseCache::init()
 380 {
 381     if (!cpuSidePort || !memSidePort)
 382         panic("Cache not hooked up on both sides\n");
 383     cpuSidePort->sendStatusChange(Port::RangeChange);
 384 }
 385
 386 void
 387 BaseCache::regStats()
 388 {
 389     Request temp_req((Addr) NULL, 4, 0);
 390     Packet::Command temp_cmd = Packet::ReadReq;
 391     Packet temp_pkt(&temp_req, temp_cmd, 0);  //@todo FIx command strings so this isn't neccessary
 392     temp_pkt.allocate(); //Temp allocate, all need data
 393
 394     using namespace Stats;
 395
 396     // Hit statistics
 397     for (int access_idx = 0; access_idx < NUM_MEM_CMDS; ++access_idx) {
 398         Packet::Command cmd = (Packet::Command)access_idx;
 399         const string &cstr = temp_pkt.cmdIdxToString(cmd);
 400
 401         hits[access_idx]
 402             .init(maxThreadsPerCPU)
 403             .name(name() + "." + cstr + "_hits")
 404             .desc("number of " + cstr + " hits")
 405             .flags(total | nozero | nonan)
 406             ;
 407     }
 408
 409     demandHits
 410         .name(name() + ".demand_hits")
 411         .desc("number of demand (read+write) hits")
 412         .flags(total)
 413         ;
 414     demandHits = hits[Packet::ReadReq] + hits[Packet::WriteReq];
 415
 416     overallHits
 417         .name(name() + ".overall_hits")
 418         .desc("number of overall hits")
 419         .flags(total)
 420         ;
 421     overallHits = demandHits + hits[Packet::SoftPFReq] + hits[Packet::HardPFReq]
 422         + hits[Packet::Writeback];
 423
 424     // Miss statistics
 425     for (int access_idx = 0; access_idx < NUM_MEM_CMDS; ++access_idx) {
 426         Packet::Command cmd = (Packet::Command)access_idx;
 427         const string &cstr = temp_pkt.cmdIdxToString(cmd);
 428
 429         misses[access_idx]
 430             .init(maxThreadsPerCPU)
 431             .name(name() + "." + cstr + "_misses")
 432             .desc("number of " + cstr + " misses")
 433             .flags(total | nozero | nonan)
 434             ;
 435     }
 436
 437     demandMisses
 438         .name(name() + ".demand_misses")
 439         .desc("number of demand (read+write) misses")
 440         .flags(total)
 441         ;
 442     demandMisses = misses[Packet::ReadReq] + misses[Packet::WriteReq];
 443
 444     overallMisses
 445         .name(name() + ".overall_misses")
 446         .desc("number of overall misses")
 447         .flags(total)
 448         ;
 449     overallMisses = demandMisses + misses[Packet::SoftPFReq] +
 450         misses[Packet::HardPFReq] + misses[Packet::Writeback];
 451
 452     // Miss latency statistics
 453     for (int access_idx = 0; access_idx < NUM_MEM_CMDS; ++access_idx) {
 454         Packet::Command cmd = (Packet::Command)access_idx;
 455         const string &cstr = temp_pkt.cmdIdxToString(cmd);
 456
 457         missLatency[access_idx]
 458             .init(maxThreadsPerCPU)
 459             .name(name() + "." + cstr + "_miss_latency")
 460             .desc("number of " + cstr + " miss cycles")
 461             .flags(total | nozero | nonan)
 462             ;
 463     }
 464
 465     demandMissLatency
 466         .name(name() + ".demand_miss_latency")
 467         .desc("number of demand (read+write) miss cycles")
 468         .flags(total)
 469         ;
 470     demandMissLatency = missLatency[Packet::ReadReq] + missLatency[Packet::WriteReq];
 471
 472     overallMissLatency
 473         .name(name() + ".overall_miss_latency")
 474         .desc("number of overall miss cycles")
 475         .flags(total)
 476         ;
 477     overallMissLatency = demandMissLatency + missLatency[Packet::SoftPFReq] +
 478         missLatency[Packet::HardPFReq];
 479
 480     // access formulas
 481     for (int access_idx = 0; access_idx < NUM_MEM_CMDS; ++access_idx) {
 482         Packet::Command cmd = (Packet::Command)access_idx;
 483         const string &cstr = temp_pkt.cmdIdxToString(cmd);
 484
 485         accesses[access_idx]
 486             .name(name() + "." + cstr + "_accesses")
 487             .desc("number of " + cstr + " accesses(hits+misses)")
 488             .flags(total | nozero | nonan)
 489             ;
 490
 491         accesses[access_idx] = hits[access_idx] + misses[access_idx];
 492     }
 493
 494     demandAccesses
 495         .name(name() + ".demand_accesses")
 496         .desc("number of demand (read+write) accesses")
 497         .flags(total)
 498         ;
 499     demandAccesses = demandHits + demandMisses;
 500
 501     overallAccesses
 502         .name(name() + ".overall_accesses")
 503         .desc("number of overall (read+write) accesses")
 504         .flags(total)
 505         ;
 506     overallAccesses = overallHits + overallMisses;
 507
 508     // miss rate formulas
 509     for (int access_idx = 0; access_idx < NUM_MEM_CMDS; ++access_idx) {
 510         Packet::Command cmd = (Packet::Command)access_idx;
 511         const string &cstr = temp_pkt.cmdIdxToString(cmd);
 512
 513         missRate[access_idx]
 514             .name(name() + "." + cstr + "_miss_rate")
 515             .desc("miss rate for " + cstr + " accesses")
 516             .flags(total | nozero | nonan)
 517             ;
 518
 519         missRate[access_idx] = misses[access_idx] / accesses[access_idx];
 520     }
 521
 522     demandMissRate
 523         .name(name() + ".demand_miss_rate")
 524         .desc("miss rate for demand accesses")
 525         .flags(total)
 526         ;
 527     demandMissRate = demandMisses / demandAccesses;
 528
 529     overallMissRate
 530         .name(name() + ".overall_miss_rate")
 531         .desc("miss rate for overall accesses")
 532         .flags(total)
 533         ;
 534     overallMissRate = overallMisses / overallAccesses;
 535
 536     // miss latency formulas
 537     for (int access_idx = 0; access_idx < NUM_MEM_CMDS; ++access_idx) {
 538         Packet::Command cmd = (Packet::Command)access_idx;
 539         const string &cstr = temp_pkt.cmdIdxToString(cmd);
 540
 541         avgMissLatency[access_idx]
 542             .name(name() + "." + cstr + "_avg_miss_latency")
 543             .desc("average " + cstr + " miss latency")
 544             .flags(total | nozero | nonan)
 545             ;
 546
 547         avgMissLatency[access_idx] =
 548             missLatency[access_idx] / misses[access_idx];
 549     }
 550
 551     demandAvgMissLatency
 552         .name(name() + ".demand_avg_miss_latency")
 553         .desc("average overall miss latency")
 554         .flags(total)
 555         ;
 556     demandAvgMissLatency = demandMissLatency / demandMisses;
 557
 558     overallAvgMissLatency
 559         .name(name() + ".overall_avg_miss_latency")
 560         .desc("average overall miss latency")
 561         .flags(total)
 562         ;
 563     overallAvgMissLatency = overallMissLatency / overallMisses;
 564
 565     blocked_cycles.init(NUM_BLOCKED_CAUSES);
 566     blocked_cycles
 567         .name(name() + ".blocked_cycles")
 568         .desc("number of cycles access was blocked")
 569         .subname(Blocked_NoMSHRs, "no_mshrs")
 570         .subname(Blocked_NoTargets, "no_targets")
 571         ;
 572
 573
 574     blocked_causes.init(NUM_BLOCKED_CAUSES);
 575     blocked_causes
 576         .name(name() + ".blocked")
 577         .desc("number of cycles access was blocked")
 578         .subname(Blocked_NoMSHRs, "no_mshrs")
 579         .subname(Blocked_NoTargets, "no_targets")
 580         ;
 581
 582     avg_blocked
 583         .name(name() + ".avg_blocked_cycles")
 584         .desc("average number of cycles each access was blocked")
 585         .subname(Blocked_NoMSHRs, "no_mshrs")
 586         .subname(Blocked_NoTargets, "no_targets")
 587         ;
 588
 589     avg_blocked = blocked_cycles / blocked_causes;
 590
 591     fastWrites
 592         .name(name() + ".fast_writes")
 593         .desc("number of fast writes performed")
 594         ;
 595
 596     cacheCopies
 597         .name(name() + ".cache_copies")
 598         .desc("number of cache copies performed")
 599         ;
 600
 601 }