lsq_unit_impl.hh revision 3594:e401993e0cbb 
1/*
2 * Copyright (c) 2004-2005 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: Kevin Lim
29 *          Korey Sewell
30 */
31
32#include "arch/locked_mem.hh"
33#include "config/use_checker.hh"
34
35#include "cpu/o3/lsq.hh"
36#include "cpu/o3/lsq_unit.hh"
37#include "base/str.hh"
38#include "mem/packet.hh"
39#include "mem/request.hh"
40
41#if USE_CHECKER
42#include "cpu/checker/cpu.hh"
43#endif
44
45template<class Impl>
46LSQUnit<Impl>::WritebackEvent::WritebackEvent(DynInstPtr &_inst, PacketPtr _pkt,
47                                              LSQUnit *lsq_ptr)
48    : Event(&mainEventQueue), inst(_inst), pkt(_pkt), lsqPtr(lsq_ptr)
49{
50    this->setFlags(Event::AutoDelete);
51}
52
53template<class Impl>
54void
55LSQUnit<Impl>::WritebackEvent::process()
56{
57    if (!lsqPtr->isSwitchedOut()) {
58        lsqPtr->writeback(inst, pkt);
59    }
60    delete pkt;
61}
62
63template<class Impl>
64const char *
65LSQUnit<Impl>::WritebackEvent::description()
66{
67    return "Store writeback event";
68}
69
70template<class Impl>
71void
72LSQUnit<Impl>::completeDataAccess(PacketPtr pkt)
73{
74    LSQSenderState *state = dynamic_cast<LSQSenderState *>(pkt->senderState);
75    DynInstPtr inst = state->inst;
76    DPRINTF(IEW, "Writeback event [sn:%lli]\n", inst->seqNum);
77    DPRINTF(Activity, "Activity: Writeback event [sn:%lli]\n", inst->seqNum);
78
79    //iewStage->ldstQueue.removeMSHR(inst->threadNumber,inst->seqNum);
80
81    if (isSwitchedOut() || inst->isSquashed()) {
82        iewStage->decrWb(inst->seqNum);
83        delete state;
84        delete pkt;
85        return;
86    } else {
87        if (!state->noWB) {
88            writeback(inst, pkt);
89        }
90
91        if (inst->isStore()) {
92            completeStore(state->idx);
93        }
94    }
95
96    delete state;
97    delete pkt;
98}
99
100template <class Impl>
101LSQUnit<Impl>::LSQUnit()
102    : loads(0), stores(0), storesToWB(0), stalled(false),
103      isStoreBlocked(false), isLoadBlocked(false),
104      loadBlockedHandled(false)
105{
106}
107
108template<class Impl>
109void
110LSQUnit<Impl>::init(Params *params, LSQ *lsq_ptr, unsigned maxLQEntries,
111                    unsigned maxSQEntries, unsigned id)
112{
113    DPRINTF(LSQUnit, "Creating LSQUnit%i object.\n",id);
114
115    switchedOut = false;
116
117    lsq = lsq_ptr;
118
119    lsqID = id;
120
121    // Add 1 for the sentinel entry (they are circular queues).
122    LQEntries = maxLQEntries + 1;
123    SQEntries = maxSQEntries + 1;
124
125    loadQueue.resize(LQEntries);
126    storeQueue.resize(SQEntries);
127
128    loadHead = loadTail = 0;
129
130    storeHead = storeWBIdx = storeTail = 0;
131
132    usedPorts = 0;
133    cachePorts = params->cachePorts;
134
135    retryPkt = NULL;
136    memDepViolator = NULL;
137
138    blockedLoadSeqNum = 0;
139}
140
141template<class Impl>
142void
143LSQUnit<Impl>::setCPU(O3CPU *cpu_ptr)
144{
145    cpu = cpu_ptr;
146
147#if USE_CHECKER
148    if (cpu->checker) {
149        cpu->checker->setDcachePort(dcachePort);
150    }
151#endif
152}
153
154template<class Impl>
155std::string
156LSQUnit<Impl>::name() const
157{
158    if (Impl::MaxThreads == 1) {
159        return iewStage->name() + ".lsq";
160    } else {
161        return iewStage->name() + ".lsq.thread." + to_string(lsqID);
162    }
163}
164
165template<class Impl>
166void
167LSQUnit<Impl>::regStats()
168{
169    lsqForwLoads
170        .name(name() + ".forwLoads")
171        .desc("Number of loads that had data forwarded from stores");
172
173    invAddrLoads
174        .name(name() + ".invAddrLoads")
175        .desc("Number of loads ignored due to an invalid address");
176
177    lsqSquashedLoads
178        .name(name() + ".squashedLoads")
179        .desc("Number of loads squashed");
180
181    lsqIgnoredResponses
182        .name(name() + ".ignoredResponses")
183        .desc("Number of memory responses ignored because the instruction is squashed");
184
185    lsqMemOrderViolation
186        .name(name() + ".memOrderViolation")
187        .desc("Number of memory ordering violations");
188
189    lsqSquashedStores
190        .name(name() + ".squashedStores")
191        .desc("Number of stores squashed");
192
193    invAddrSwpfs
194        .name(name() + ".invAddrSwpfs")
195        .desc("Number of software prefetches ignored due to an invalid address");
196
197    lsqBlockedLoads
198        .name(name() + ".blockedLoads")
199        .desc("Number of blocked loads due to partial load-store forwarding");
200
201    lsqRescheduledLoads
202        .name(name() + ".rescheduledLoads")
203        .desc("Number of loads that were rescheduled");
204
205    lsqCacheBlocked
206        .name(name() + ".cacheBlocked")
207        .desc("Number of times an access to memory failed due to the cache being blocked");
208}
209
210template<class Impl>
211void
212LSQUnit<Impl>::clearLQ()
213{
214    loadQueue.clear();
215}
216
217template<class Impl>
218void
219LSQUnit<Impl>::clearSQ()
220{
221    storeQueue.clear();
222}
223
224template<class Impl>
225void
226LSQUnit<Impl>::switchOut()
227{
228    switchedOut = true;
229    for (int i = 0; i < loadQueue.size(); ++i) {
230        assert(!loadQueue[i]);
231        loadQueue[i] = NULL;
232    }
233
234    assert(storesToWB == 0);
235}
236
237template<class Impl>
238void
239LSQUnit<Impl>::takeOverFrom()
240{
241    switchedOut = false;
242    loads = stores = storesToWB = 0;
243
244    loadHead = loadTail = 0;
245
246    storeHead = storeWBIdx = storeTail = 0;
247
248    usedPorts = 0;
249
250    memDepViolator = NULL;
251
252    blockedLoadSeqNum = 0;
253
254    stalled = false;
255    isLoadBlocked = false;
256    loadBlockedHandled = false;
257}
258
259template<class Impl>
260void
261LSQUnit<Impl>::resizeLQ(unsigned size)
262{
263    unsigned size_plus_sentinel = size + 1;
264    assert(size_plus_sentinel >= LQEntries);
265
266    if (size_plus_sentinel > LQEntries) {
267        while (size_plus_sentinel > loadQueue.size()) {
268            DynInstPtr dummy;
269            loadQueue.push_back(dummy);
270            LQEntries++;
271        }
272    } else {
273        LQEntries = size_plus_sentinel;
274    }
275
276}
277
278template<class Impl>
279void
280LSQUnit<Impl>::resizeSQ(unsigned size)
281{
282    unsigned size_plus_sentinel = size + 1;
283    if (size_plus_sentinel > SQEntries) {
284        while (size_plus_sentinel > storeQueue.size()) {
285            SQEntry dummy;
286            storeQueue.push_back(dummy);
287            SQEntries++;
288        }
289    } else {
290        SQEntries = size_plus_sentinel;
291    }
292}
293
294template <class Impl>
295void
296LSQUnit<Impl>::insert(DynInstPtr &inst)
297{
298    assert(inst->isMemRef());
299
300    assert(inst->isLoad() || inst->isStore());
301
302    if (inst->isLoad()) {
303        insertLoad(inst);
304    } else {
305        insertStore(inst);
306    }
307
308    inst->setInLSQ();
309}
310
311template <class Impl>
312void
313LSQUnit<Impl>::insertLoad(DynInstPtr &load_inst)
314{
315    assert((loadTail + 1) % LQEntries != loadHead);
316    assert(loads < LQEntries);
317
318    DPRINTF(LSQUnit, "Inserting load PC %#x, idx:%i [sn:%lli]\n",
319            load_inst->readPC(), loadTail, load_inst->seqNum);
320
321    load_inst->lqIdx = loadTail;
322
323    if (stores == 0) {
324        load_inst->sqIdx = -1;
325    } else {
326        load_inst->sqIdx = storeTail;
327    }
328
329    loadQueue[loadTail] = load_inst;
330
331    incrLdIdx(loadTail);
332
333    ++loads;
334}
335
336template <class Impl>
337void
338LSQUnit<Impl>::insertStore(DynInstPtr &store_inst)
339{
340    // Make sure it is not full before inserting an instruction.
341    assert((storeTail + 1) % SQEntries != storeHead);
342    assert(stores < SQEntries);
343
344    DPRINTF(LSQUnit, "Inserting store PC %#x, idx:%i [sn:%lli]\n",
345            store_inst->readPC(), storeTail, store_inst->seqNum);
346
347    store_inst->sqIdx = storeTail;
348    store_inst->lqIdx = loadTail;
349
350    storeQueue[storeTail] = SQEntry(store_inst);
351
352    incrStIdx(storeTail);
353
354    ++stores;
355}
356
357template <class Impl>
358typename Impl::DynInstPtr
359LSQUnit<Impl>::getMemDepViolator()
360{
361    DynInstPtr temp = memDepViolator;
362
363    memDepViolator = NULL;
364
365    return temp;
366}
367
368template <class Impl>
369unsigned
370LSQUnit<Impl>::numFreeEntries()
371{
372    unsigned free_lq_entries = LQEntries - loads;
373    unsigned free_sq_entries = SQEntries - stores;
374
375    // Both the LQ and SQ entries have an extra dummy entry to differentiate
376    // empty/full conditions.  Subtract 1 from the free entries.
377    if (free_lq_entries < free_sq_entries) {
378        return free_lq_entries - 1;
379    } else {
380        return free_sq_entries - 1;
381    }
382}
383
384template <class Impl>
385int
386LSQUnit<Impl>::numLoadsReady()
387{
388    int load_idx = loadHead;
389    int retval = 0;
390
391    while (load_idx != loadTail) {
392        assert(loadQueue[load_idx]);
393
394        if (loadQueue[load_idx]->readyToIssue()) {
395            ++retval;
396        }
397    }
398
399    return retval;
400}
401
402template <class Impl>
403Fault
404LSQUnit<Impl>::executeLoad(DynInstPtr &inst)
405{
406    // Execute a specific load.
407    Fault load_fault = NoFault;
408
409    DPRINTF(LSQUnit, "Executing load PC %#x, [sn:%lli]\n",
410            inst->readPC(),inst->seqNum);
411
412    load_fault = inst->initiateAcc();
413
414    // If the instruction faulted, then we need to send it along to commit
415    // without the instruction completing.
416    if (load_fault != NoFault) {
417        // Send this instruction to commit, also make sure iew stage
418        // realizes there is activity.
419        // Mark it as executed unless it is an uncached load that
420        // needs to hit the head of commit.
421        if (!(inst->req->isUncacheable()) || inst->isAtCommit()) {
422            inst->setExecuted();
423        }
424        iewStage->instToCommit(inst);
425        iewStage->activityThisCycle();
426    }
427
428    return load_fault;
429}
430
431template <class Impl>
432Fault
433LSQUnit<Impl>::executeStore(DynInstPtr &store_inst)
434{
435    using namespace TheISA;
436    // Make sure that a store exists.
437    assert(stores != 0);
438
439    int store_idx = store_inst->sqIdx;
440
441    DPRINTF(LSQUnit, "Executing store PC %#x [sn:%lli]\n",
442            store_inst->readPC(), store_inst->seqNum);
443
444    // Check the recently completed loads to see if any match this store's
445    // address.  If so, then we have a memory ordering violation.
446    int load_idx = store_inst->lqIdx;
447
448    Fault store_fault = store_inst->initiateAcc();
449
450    if (storeQueue[store_idx].size == 0) {
451        DPRINTF(LSQUnit,"Fault on Store PC %#x, [sn:%lli],Size = 0\n",
452                store_inst->readPC(),store_inst->seqNum);
453
454        return store_fault;
455    }
456
457    assert(store_fault == NoFault);
458
459    if (store_inst->isStoreConditional()) {
460        // Store conditionals need to set themselves as able to
461        // writeback if we haven't had a fault by here.
462        storeQueue[store_idx].canWB = true;
463
464        ++storesToWB;
465    }
466
467    if (!memDepViolator) {
468        while (load_idx != loadTail) {
469            // Really only need to check loads that have actually executed
470            // It's safe to check all loads because effAddr is set to
471            // InvalAddr when the dyn inst is created.
472
473            // @todo: For now this is extra conservative, detecting a
474            // violation if the addresses match assuming all accesses
475            // are quad word accesses.
476
477            // @todo: Fix this, magic number being used here
478            if ((loadQueue[load_idx]->effAddr >> 8) ==
479                (store_inst->effAddr >> 8)) {
480                // A load incorrectly passed this store.  Squash and refetch.
481                // For now return a fault to show that it was unsuccessful.
482                memDepViolator = loadQueue[load_idx];
483                ++lsqMemOrderViolation;
484
485                return genMachineCheckFault();
486            }
487
488            incrLdIdx(load_idx);
489        }
490
491        // If we've reached this point, there was no violation.
492        memDepViolator = NULL;
493    }
494
495    return store_fault;
496}
497
498template <class Impl>
499void
500LSQUnit<Impl>::commitLoad()
501{
502    assert(loadQueue[loadHead]);
503
504    DPRINTF(LSQUnit, "Committing head load instruction, PC %#x\n",
505            loadQueue[loadHead]->readPC());
506
507    loadQueue[loadHead] = NULL;
508
509    incrLdIdx(loadHead);
510
511    --loads;
512}
513
514template <class Impl>
515void
516LSQUnit<Impl>::commitLoads(InstSeqNum &youngest_inst)
517{
518    assert(loads == 0 || loadQueue[loadHead]);
519
520    while (loads != 0 && loadQueue[loadHead]->seqNum <= youngest_inst) {
521        commitLoad();
522    }
523}
524
525template <class Impl>
526void
527LSQUnit<Impl>::commitStores(InstSeqNum &youngest_inst)
528{
529    assert(stores == 0 || storeQueue[storeHead].inst);
530
531    int store_idx = storeHead;
532
533    while (store_idx != storeTail) {
534        assert(storeQueue[store_idx].inst);
535        // Mark any stores that are now committed and have not yet
536        // been marked as able to write back.
537        if (!storeQueue[store_idx].canWB) {
538            if (storeQueue[store_idx].inst->seqNum > youngest_inst) {
539                break;
540            }
541            DPRINTF(LSQUnit, "Marking store as able to write back, PC "
542                    "%#x [sn:%lli]\n",
543                    storeQueue[store_idx].inst->readPC(),
544                    storeQueue[store_idx].inst->seqNum);
545
546            storeQueue[store_idx].canWB = true;
547
548            ++storesToWB;
549        }
550
551        incrStIdx(store_idx);
552    }
553}
554
555template <class Impl>
556void
557LSQUnit<Impl>::writebackStores()
558{
559    while (storesToWB > 0 &&
560           storeWBIdx != storeTail &&
561           storeQueue[storeWBIdx].inst &&
562           storeQueue[storeWBIdx].canWB &&
563           usedPorts < cachePorts) {
564
565        if (isStoreBlocked || lsq->cacheBlocked()) {
566            DPRINTF(LSQUnit, "Unable to write back any more stores, cache"
567                    " is blocked!\n");
568            break;
569        }
570
571        // Store didn't write any data so no need to write it back to
572        // memory.
573        if (storeQueue[storeWBIdx].size == 0) {
574            completeStore(storeWBIdx);
575
576            incrStIdx(storeWBIdx);
577
578            continue;
579        }
580
581        ++usedPorts;
582
583        if (storeQueue[storeWBIdx].inst->isDataPrefetch()) {
584            incrStIdx(storeWBIdx);
585
586            continue;
587        }
588
589        assert(storeQueue[storeWBIdx].req);
590        assert(!storeQueue[storeWBIdx].committed);
591
592        DynInstPtr inst = storeQueue[storeWBIdx].inst;
593
594        Request *req = storeQueue[storeWBIdx].req;
595        storeQueue[storeWBIdx].committed = true;
596
597        assert(!inst->memData);
598        inst->memData = new uint8_t[64];
599        memcpy(inst->memData, (uint8_t *)&storeQueue[storeWBIdx].data,
600               req->getSize());
601
602        PacketPtr data_pkt = new Packet(req, Packet::WriteReq, Packet::Broadcast);
603        data_pkt->dataStatic(inst->memData);
604
605        LSQSenderState *state = new LSQSenderState;
606        state->isLoad = false;
607        state->idx = storeWBIdx;
608        state->inst = inst;
609        data_pkt->senderState = state;
610
611        DPRINTF(LSQUnit, "D-Cache: Writing back store idx:%i PC:%#x "
612                "to Addr:%#x, data:%#x [sn:%lli]\n",
613                storeWBIdx, inst->readPC(),
614                req->getPaddr(), *(inst->memData),
615                inst->seqNum);
616
617        // @todo: Remove this SC hack once the memory system handles it.
618        if (req->isLocked()) {
619            // Disable recording the result temporarily.  Writing to
620            // misc regs normally updates the result, but this is not
621            // the desired behavior when handling store conditionals.
622            inst->recordResult = false;
623            bool success = TheISA::handleLockedWrite(inst.get(), req);
624            inst->recordResult = true;
625
626            if (!success) {
627                // Instantly complete this store.
628                DPRINTF(LSQUnit, "Store conditional [sn:%lli] failed.  "
629                        "Instantly completing it.\n",
630                        inst->seqNum);
631                WritebackEvent *wb = new WritebackEvent(inst, data_pkt, this);
632                wb->schedule(curTick + 1);
633                delete state;
634                completeStore(storeWBIdx);
635                incrStIdx(storeWBIdx);
636                continue;
637            }
638        } else {
639            // Non-store conditionals do not need a writeback.
640            state->noWB = true;
641        }
642
643        if (!dcachePort->sendTiming(data_pkt)) {
644            if (data_pkt->result == Packet::BadAddress) {
645                panic("LSQ sent out a bad address for a completed store!");
646            }
647            // Need to handle becoming blocked on a store.
648            DPRINTF(IEW, "D-Cache became blcoked when writing [sn:%lli], will"
649                    "retry later\n",
650                    inst->seqNum);
651            isStoreBlocked = true;
652            ++lsqCacheBlocked;
653            assert(retryPkt == NULL);
654            retryPkt = data_pkt;
655            lsq->setRetryTid(lsqID);
656        } else {
657            storePostSend(data_pkt);
658        }
659    }
660
661    // Not sure this should set it to 0.
662    usedPorts = 0;
663
664    assert(stores >= 0 && storesToWB >= 0);
665}
666
667/*template <class Impl>
668void
669LSQUnit<Impl>::removeMSHR(InstSeqNum seqNum)
670{
671    list<InstSeqNum>::iterator mshr_it = find(mshrSeqNums.begin(),
672                                              mshrSeqNums.end(),
673                                              seqNum);
674
675    if (mshr_it != mshrSeqNums.end()) {
676        mshrSeqNums.erase(mshr_it);
677        DPRINTF(LSQUnit, "Removing MSHR. count = %i\n",mshrSeqNums.size());
678    }
679}*/
680
681template <class Impl>
682void
683LSQUnit<Impl>::squash(const InstSeqNum &squashed_num)
684{
685    DPRINTF(LSQUnit, "Squashing until [sn:%lli]!"
686            "(Loads:%i Stores:%i)\n", squashed_num, loads, stores);
687
688    int load_idx = loadTail;
689    decrLdIdx(load_idx);
690
691    while (loads != 0 && loadQueue[load_idx]->seqNum > squashed_num) {
692        DPRINTF(LSQUnit,"Load Instruction PC %#x squashed, "
693                "[sn:%lli]\n",
694                loadQueue[load_idx]->readPC(),
695                loadQueue[load_idx]->seqNum);
696
697        if (isStalled() && load_idx == stallingLoadIdx) {
698            stalled = false;
699            stallingStoreIsn = 0;
700            stallingLoadIdx = 0;
701        }
702
703        // Clear the smart pointer to make sure it is decremented.
704        loadQueue[load_idx]->setSquashed();
705        loadQueue[load_idx] = NULL;
706        --loads;
707
708        // Inefficient!
709        loadTail = load_idx;
710
711        decrLdIdx(load_idx);
712        ++lsqSquashedLoads;
713    }
714
715    if (isLoadBlocked) {
716        if (squashed_num < blockedLoadSeqNum) {
717            isLoadBlocked = false;
718            loadBlockedHandled = false;
719            blockedLoadSeqNum = 0;
720        }
721    }
722
723    int store_idx = storeTail;
724    decrStIdx(store_idx);
725
726    while (stores != 0 &&
727           storeQueue[store_idx].inst->seqNum > squashed_num) {
728        // Instructions marked as can WB are already committed.
729        if (storeQueue[store_idx].canWB) {
730            break;
731        }
732
733        DPRINTF(LSQUnit,"Store Instruction PC %#x squashed, "
734                "idx:%i [sn:%lli]\n",
735                storeQueue[store_idx].inst->readPC(),
736                store_idx, storeQueue[store_idx].inst->seqNum);
737
738        // I don't think this can happen.  It should have been cleared
739        // by the stalling load.
740        if (isStalled() &&
741            storeQueue[store_idx].inst->seqNum == stallingStoreIsn) {
742            panic("Is stalled should have been cleared by stalling load!\n");
743            stalled = false;
744            stallingStoreIsn = 0;
745        }
746
747        // Clear the smart pointer to make sure it is decremented.
748        storeQueue[store_idx].inst->setSquashed();
749        storeQueue[store_idx].inst = NULL;
750        storeQueue[store_idx].canWB = 0;
751
752        storeQueue[store_idx].req = NULL;
753        --stores;
754
755        // Inefficient!
756        storeTail = store_idx;
757
758        decrStIdx(store_idx);
759        ++lsqSquashedStores;
760    }
761}
762
763template <class Impl>
764void
765LSQUnit<Impl>::storePostSend(PacketPtr pkt)
766{
767    if (isStalled() &&
768        storeQueue[storeWBIdx].inst->seqNum == stallingStoreIsn) {
769        DPRINTF(LSQUnit, "Unstalling, stalling store [sn:%lli] "
770                "load idx:%i\n",
771                stallingStoreIsn, stallingLoadIdx);
772        stalled = false;
773        stallingStoreIsn = 0;
774        iewStage->replayMemInst(loadQueue[stallingLoadIdx]);
775    }
776
777    if (!storeQueue[storeWBIdx].inst->isStoreConditional()) {
778        // The store is basically completed at this time. This
779        // only works so long as the checker doesn't try to
780        // verify the value in memory for stores.
781        storeQueue[storeWBIdx].inst->setCompleted();
782#if USE_CHECKER
783        if (cpu->checker) {
784            cpu->checker->verify(storeQueue[storeWBIdx].inst);
785        }
786#endif
787    }
788
789    if (pkt->result != Packet::Success) {
790        DPRINTF(LSQUnit,"D-Cache Write Miss on idx:%i!\n",
791                storeWBIdx);
792
793        DPRINTF(Activity, "Active st accessing mem miss [sn:%lli]\n",
794                storeQueue[storeWBIdx].inst->seqNum);
795
796        //mshrSeqNums.push_back(storeQueue[storeWBIdx].inst->seqNum);
797
798        //DPRINTF(LSQUnit, "Added MSHR. count = %i\n",mshrSeqNums.size());
799
800        // @todo: Increment stat here.
801    } else {
802        DPRINTF(LSQUnit,"D-Cache: Write Hit on idx:%i !\n",
803                storeWBIdx);
804
805        DPRINTF(Activity, "Active st accessing mem hit [sn:%lli]\n",
806                storeQueue[storeWBIdx].inst->seqNum);
807    }
808
809    incrStIdx(storeWBIdx);
810}
811
812template <class Impl>
813void
814LSQUnit<Impl>::writeback(DynInstPtr &inst, PacketPtr pkt)
815{
816    iewStage->wakeCPU();
817
818    // Squashed instructions do not need to complete their access.
819    if (inst->isSquashed()) {
820        iewStage->decrWb(inst->seqNum);
821        assert(!inst->isStore());
822        ++lsqIgnoredResponses;
823        return;
824    }
825
826    if (!inst->isExecuted()) {
827        inst->setExecuted();
828
829        // Complete access to copy data to proper place.
830        inst->completeAcc(pkt);
831    }
832
833    // Need to insert instruction into queue to commit
834    iewStage->instToCommit(inst);
835
836    iewStage->activityThisCycle();
837}
838
839template <class Impl>
840void
841LSQUnit<Impl>::completeStore(int store_idx)
842{
843    assert(storeQueue[store_idx].inst);
844    storeQueue[store_idx].completed = true;
845    --storesToWB;
846    // A bit conservative because a store completion may not free up entries,
847    // but hopefully avoids two store completions in one cycle from making
848    // the CPU tick twice.
849    cpu->wakeCPU();
850    cpu->activityThisCycle();
851
852    if (store_idx == storeHead) {
853        do {
854            incrStIdx(storeHead);
855
856            --stores;
857        } while (storeQueue[storeHead].completed &&
858                 storeHead != storeTail);
859
860        iewStage->updateLSQNextCycle = true;
861    }
862
863    DPRINTF(LSQUnit, "Completing store [sn:%lli], idx:%i, store head "
864            "idx:%i\n",
865            storeQueue[store_idx].inst->seqNum, store_idx, storeHead);
866
867    if (isStalled() &&
868        storeQueue[store_idx].inst->seqNum == stallingStoreIsn) {
869        DPRINTF(LSQUnit, "Unstalling, stalling store [sn:%lli] "
870                "load idx:%i\n",
871                stallingStoreIsn, stallingLoadIdx);
872        stalled = false;
873        stallingStoreIsn = 0;
874        iewStage->replayMemInst(loadQueue[stallingLoadIdx]);
875    }
876
877    storeQueue[store_idx].inst->setCompleted();
878
879    // Tell the checker we've completed this instruction.  Some stores
880    // may get reported twice to the checker, but the checker can
881    // handle that case.
882#if USE_CHECKER
883    if (cpu->checker) {
884        cpu->checker->verify(storeQueue[store_idx].inst);
885    }
886#endif
887}
888
889template <class Impl>
890void
891LSQUnit<Impl>::recvRetry()
892{
893    if (isStoreBlocked) {
894        assert(retryPkt != NULL);
895
896        if (dcachePort->sendTiming(retryPkt)) {
897            if (retryPkt->result == Packet::BadAddress) {
898                panic("LSQ sent out a bad address for a completed store!");
899            }
900            storePostSend(retryPkt);
901            retryPkt = NULL;
902            isStoreBlocked = false;
903            lsq->setRetryTid(-1);
904        } else {
905            // Still blocked!
906            ++lsqCacheBlocked;
907            lsq->setRetryTid(lsqID);
908        }
909    } else if (isLoadBlocked) {
910        DPRINTF(LSQUnit, "Loads squash themselves and all younger insts, "
911                "no need to resend packet.\n");
912    } else {
913        DPRINTF(LSQUnit, "Retry received but LSQ is no longer blocked.\n");
914    }
915}
916
917template <class Impl>
918inline void
919LSQUnit<Impl>::incrStIdx(int &store_idx)
920{
921    if (++store_idx >= SQEntries)
922        store_idx = 0;
923}
924
925template <class Impl>
926inline void
927LSQUnit<Impl>::decrStIdx(int &store_idx)
928{
929    if (--store_idx < 0)
930        store_idx += SQEntries;
931}
932
933template <class Impl>
934inline void
935LSQUnit<Impl>::incrLdIdx(int &load_idx)
936{
937    if (++load_idx >= LQEntries)
938        load_idx = 0;
939}
940
941template <class Impl>
942inline void
943LSQUnit<Impl>::decrLdIdx(int &load_idx)
944{
945    if (--load_idx < 0)
946        load_idx += LQEntries;
947}
948
949template <class Impl>
950void
951LSQUnit<Impl>::dumpInsts()
952{
953    cprintf("Load store queue: Dumping instructions.\n");
954    cprintf("Load queue size: %i\n", loads);
955    cprintf("Load queue: ");
956
957    int load_idx = loadHead;
958
959    while (load_idx != loadTail && loadQueue[load_idx]) {
960        cprintf("%#x ", loadQueue[load_idx]->readPC());
961
962        incrLdIdx(load_idx);
963    }
964
965    cprintf("Store queue size: %i\n", stores);
966    cprintf("Store queue: ");
967
968    int store_idx = storeHead;
969
970    while (store_idx != storeTail && storeQueue[store_idx].inst) {
971        cprintf("%#x ", storeQueue[store_idx].inst->readPC());
972
973        incrStIdx(store_idx);
974    }
975
976    cprintf("\n");
977}
978