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, int asid) 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, int asid, 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(Packet * &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->addr) {
  98             if (mshr->addr + mshr->pkt->size > pkt->addr) {
  99                 return mshr;
 100             }
 101         } else {
 102             if (pkt->addr + pkt->size > mshr->addr) {
 103                 return mshr;
 104             }
 105         }
 106
 107         //need to check destination address for copies.
 108         if (mshr->pkt->cmd == Copy) {
 109             Addr dest = mshr->pkt->dest;
 110             if (dest < pkt->addr) {
 111                 if (dest + mshr->pkt->size > pkt->addr) {
 112                     return mshr;
 113                 }
 114             } else {
 115                 if (pkt->addr + pkt->size > dest) {
 116                     return mshr;
 117                 }
 118             }
 119         }
 120     }
 121     return NULL;
 122 }
 123
 124 MSHR*
 125 MSHRQueue::allocate(Packet * &pkt, int size)
 126 {
 127     Addr aligned_addr = pkt->addr & ~((Addr)size - 1);
 128     MSHR *mshr = freeList.front();
 129     assert(mshr->getNumTargets() == 0);
 130     freeList.pop_front();
 131
 132     if (pkt->cmd.isNoResponse()) {
 133         mshr->allocateAsBuffer(pkt);
 134     } else {
 135         assert(size !=0);
 136         mshr->allocate(pkt->cmd, aligned_addr, pkt->req->req->asid, size, pkt);
 137         allocatedTargets += 1;
 138     }
 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::allocateFetch(Addr addr, int asid, int size, Packet * &target)
 148 {
 149     MSHR *mshr = freeList.front();
 150     assert(mshr->getNumTargets() == 0);
 151     freeList.pop_front();
 152     mshr->allocate(Read, addr, asid, size, target);
 153     mshr->allocIter = allocatedList.insert(allocatedList.end(), mshr);
 154     mshr->readyIter = pendingList.insert(pendingList.end(), mshr);
 155
 156     allocated += 1;
 157     return mshr;
 158 }
 159
 160 MSHR*
 161 MSHRQueue::allocateTargetList(Addr addr, int asid, int size)
 162 {
 163     MSHR *mshr = freeList.front();
 164     assert(mshr->getNumTargets() == 0);
 165     freeList.pop_front();
 166     Packet * dummy;
 167     mshr->allocate(Read, addr, asid, size, dummy);
 168     mshr->allocIter = allocatedList.insert(allocatedList.end(), mshr);
 169     mshr->inService = true;
 170     ++inServiceMSHRs;
 171     ++allocated;
 172     return mshr;
 173 }
 174
 175
 176 void
 177 MSHRQueue::deallocate(MSHR* mshr)
 178 {
 179     deallocateOne(mshr);
 180 }
 181
 182 MSHR::Iterator
 183 MSHRQueue::deallocateOne(MSHR* mshr)
 184 {
 185     MSHR::Iterator retval = allocatedList.erase(mshr->allocIter);
 186     freeList.push_front(mshr);
 187     allocated--;
 188     allocatedTargets -= mshr->getNumTargets();
 189     if (mshr->inService) {
 190         inServiceMSHRs--;
 191     } else {
 192         pendingList.erase(mshr->readyIter);
 193     }
 194     mshr->deallocate();
 195     return retval;
 196 }
 197
 198 void
 199 MSHRQueue::moveToFront(MSHR *mshr)
 200 {
 201     if (!mshr->inService) {
 202         assert(mshr == *(mshr->readyIter));
 203         pendingList.erase(mshr->readyIter);
 204         mshr->readyIter = pendingList.insert(pendingList.begin(), mshr);
 205     }
 206 }
 207
 208 void
 209 MSHRQueue::markInService(MSHR* mshr)
 210 {
 211     //assert(mshr == pendingList.front());
 212     if (mshr->pkt->cmd.isNoResponse()) {
 213         assert(mshr->getNumTargets() == 0);
 214         deallocate(mshr);
 215         return;
 216     }
 217     mshr->inService = true;
 218     pendingList.erase(mshr->readyIter);
 219     mshr->readyIter = NULL;
 220     inServiceMSHRs += 1;
 221     //pendingList.pop_front();
 222 }
 223
 224 void
 225 MSHRQueue::markPending(MSHR* mshr, Packet::Command cmd)
 226 {
 227     assert(mshr->readyIter == NULL);
 228     mshr->pkt->cmd = cmd;
 229     mshr->pkt->flags &= ~SATISFIED;
 230     mshr->inService = false;
 231     --inServiceMSHRs;
 232     /**
 233      * @ todo might want to add rerequests to front of pending list for
 234      * performance.
 235      */
 236     mshr->readyIter = pendingList.insert(pendingList.end(), mshr);
 237 }
 238
 239 void
 240 MSHRQueue::squash(int req->getThreadNum()ber)
 241 {
 242     MSHR::Iterator i = allocatedList.begin();
 243     MSHR::Iterator end = allocatedList.end();
 244     for (; i != end;) {
 245         MSHR *mshr = *i;
 246         if (mshr->setThreadNum() == req->getThreadNum()ber) {
 247             while (mshr->hasTargets()) {
 248                 Packet * target = mshr->getTarget();
 249                 mshr->popTarget();
 250
 251                 assert(target->req->setThreadNum() == req->getThreadNum()ber);
 252                 if (target->completionEvent != NULL) {
 253                     delete target->completionEvent;
 254                 }
 255                 target = NULL;
 256             }
 257             assert(!mshr->hasTargets());
 258             assert(mshr->ntargets==0);
 259             if (!mshr->inService) {
 260                 i = deallocateOne(mshr);
 261             } else {
 262                 //mshr->pkt->flags &= ~CACHE_LINE_FILL;
 263                 ++i;
 264             }
 265         } else {
 266             ++i;
 267         }
 268     }
 269 }