src/mem/cache/miss/mshr_queue.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 /** @file
  32  * Definition of the MSHRQueue.
  33  */
  34
  35 #include "mem/cache/miss/mshr_queue.hh"
  36 #include "sim/eventq.hh"
  37
  38 using namespace std;
  39
  40 MSHRQueue::MSHRQueue(int num_mshrs, int reserve)
  41     : numMSHRs(num_mshrs + reserve - 1), numReserve(reserve)
  42 {
  43     allocated = 0;
  44     inServiceMSHRs = 0;
  45     allocatedTargets = 0;
  46     registers = new MSHR[numMSHRs];
  47     for (int i = 0; i < numMSHRs; ++i) {
  48         freeList.push_back(&registers[i]);
  49     }
  50 }
  51
  52 MSHRQueue::~MSHRQueue()
  53 {
  54     delete [] registers;
  55 }
  56
  57 MSHR*
  58 MSHRQueue::findMatch(Addr addr) const
  59 {
  60     MSHR::ConstIterator i = allocatedList.begin();
  61     MSHR::ConstIterator end = allocatedList.end();
  62     for (; i != end; ++i) {
  63         MSHR *mshr = *i;
  64         if (mshr->addr == addr) {
  65             return mshr;
  66         }
  67     }
  68     return NULL;
  69 }
  70
  71 bool
  72 MSHRQueue::findMatches(Addr addr, vector<MSHR*>& matches) const
  73 {
  74     // Need an empty vector
  75     assert(matches.empty());
  76     bool retval = false;
  77     MSHR::ConstIterator i = allocatedList.begin();
  78     MSHR::ConstIterator end = allocatedList.end();
  79     for (; i != end; ++i) {
  80         MSHR *mshr = *i;
  81         if (mshr->addr == addr) {
  82             retval = true;
  83             matches.push_back(mshr);
  84         }
  85     }
  86     return retval;
  87
  88 }
  89
  90 MSHR*
  91 MSHRQueue::findPending(PacketPtr &pkt) const
  92 {
  93     MSHR::ConstIterator i = pendingList.begin();
  94     MSHR::ConstIterator end = pendingList.end();
  95     for (; i != end; ++i) {
  96         MSHR *mshr = *i;
  97         if (mshr->addr < pkt->getAddr()) {
  98             if (mshr->addr + mshr->pkt->getSize() > pkt->getAddr()) {
  99                 return mshr;
 100             }
 101         } else {
 102             if (pkt->getAddr() + pkt->getSize() > mshr->addr) {
 103                 return mshr;
 104             }
 105         }
 106     }
 107     return NULL;
 108 }
 109
 110 MSHR*
 111 MSHRQueue::allocate(PacketPtr &pkt, int size)
 112 {
 113     Addr aligned_addr = pkt->getAddr() & ~((Addr)size - 1);
 114     assert(!freeList.empty());
 115     MSHR *mshr = freeList.front();
 116     assert(mshr->getNumTargets() == 0);
 117     freeList.pop_front();
 118
 119     if (!pkt->needsResponse()) {
 120         mshr->allocateAsBuffer(pkt);
 121     } else {
 122         mshr->allocate(pkt->cmd, aligned_addr, size, pkt);
 123         allocatedTargets += 1;
 124     }
 125     mshr->allocIter = allocatedList.insert(allocatedList.end(), mshr);
 126     mshr->readyIter = pendingList.insert(pendingList.end(), mshr);
 127
 128     allocated += 1;
 129     return mshr;
 130 }
 131
 132 MSHR*
 133 MSHRQueue::allocateFetch(Addr addr, int size, PacketPtr &target)
 134 {
 135     MSHR *mshr = freeList.front();
 136     assert(mshr->getNumTargets() == 0);
 137     freeList.pop_front();
 138     mshr->allocate(MemCmd::ReadReq, addr, size, target);
 139     mshr->allocIter = allocatedList.insert(allocatedList.end(), mshr);
 140     mshr->readyIter = pendingList.insert(pendingList.end(), mshr);
 141
 142     allocated += 1;
 143     return mshr;
 144 }
 145
 146 MSHR*
 147 MSHRQueue::allocateTargetList(Addr addr, int size)
 148 {
 149     MSHR *mshr = freeList.front();
 150     assert(mshr->getNumTargets() == 0);
 151     freeList.pop_front();
 152     PacketPtr dummy;
 153     mshr->allocate(MemCmd::ReadReq, addr, size, dummy);
 154     mshr->allocIter = allocatedList.insert(allocatedList.end(), mshr);
 155     mshr->inService = true;
 156     ++inServiceMSHRs;
 157     ++allocated;
 158     return mshr;
 159 }
 160
 161
 162 void
 163 MSHRQueue::deallocate(MSHR* mshr)
 164 {
 165     deallocateOne(mshr);
 166 }
 167
 168 MSHR::Iterator
 169 MSHRQueue::deallocateOne(MSHR* mshr)
 170 {
 171     MSHR::Iterator retval = allocatedList.erase(mshr->allocIter);
 172     freeList.push_front(mshr);
 173     allocated--;
 174     allocatedTargets -= mshr->getNumTargets();
 175     if (mshr->inService) {
 176         inServiceMSHRs--;
 177     } else {
 178         pendingList.erase(mshr->readyIter);
 179     }
 180     mshr->deallocate();
 181     return retval;
 182 }
 183
 184 void
 185 MSHRQueue::moveToFront(MSHR *mshr)
 186 {
 187     if (!mshr->inService) {
 188         assert(mshr == *(mshr->readyIter));
 189         pendingList.erase(mshr->readyIter);
 190         mshr->readyIter = pendingList.insert(pendingList.begin(), mshr);
 191     }
 192 }
 193
 194 void
 195 MSHRQueue::markInService(MSHR* mshr)
 196 {
 197     //assert(mshr == pendingList.front());
 198     if (!mshr->pkt->needsResponse() && !(mshr->pkt->cmd == MemCmd::UpgradeReq)) {
 199         assert(mshr->getNumTargets() == 0);
 200         deallocate(mshr);
 201         return;
 202     }
 203     mshr->inService = true;
 204     pendingList.erase(mshr->readyIter);
 205     //mshr->readyIter = NULL;
 206     inServiceMSHRs += 1;
 207     //pendingList.pop_front();
 208 }
 209
 210 void
 211 MSHRQueue::markPending(MSHR* mshr, MemCmd cmd)
 212 {
 213     //assert(mshr->readyIter == NULL);
 214     mshr->pkt->cmd = cmd;
 215     mshr->pkt->flags &= ~SATISFIED;
 216     mshr->inService = false;
 217     --inServiceMSHRs;
 218     /**
 219      * @ todo might want to add rerequests to front of pending list for
 220      * performance.
 221      */
 222     mshr->readyIter = pendingList.insert(pendingList.end(), mshr);
 223 }
 224
 225 void
 226 MSHRQueue::squash(int threadNum)
 227 {
 228     MSHR::Iterator i = allocatedList.begin();
 229     MSHR::Iterator end = allocatedList.end();
 230     for (; i != end;) {
 231         MSHR *mshr = *i;
 232         if (mshr->threadNum == threadNum) {
 233             while (mshr->hasTargets()) {
 234                 PacketPtr target = mshr->getTarget();
 235                 mshr->popTarget();
 236
 237                 assert(0/*target->req->getThreadNum()*/ == threadNum);
 238                 target = NULL;
 239             }
 240             assert(!mshr->hasTargets());
 241             assert(mshr->ntargets==0);
 242             if (!mshr->inService) {
 243                 i = deallocateOne(mshr);
 244             } else {
 245                 //mshr->pkt->flags &= ~CACHE_LINE_FILL;
 246                 ++i;
 247             }
 248         } else {
 249             ++i;
 250         }
 251     }
 252 }