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->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         //need to check destination address for copies.
 108         //TEMP NOT DOING COPIES
 109 #if 0
 110         if (mshr->pkt->cmd == Copy) {
 111             Addr dest = mshr->pkt->dest;
 112             if (dest < pkt->addr) {
 113                 if (dest + mshr->pkt->size > pkt->addr) {
 114                     return mshr;
 115                 }
 116             } else {
 117                 if (pkt->addr + pkt->size > dest) {
 118                     return mshr;
 119                 }
 120             }
 121         }
 122 #endif
 123     }
 124     return NULL;
 125 }
 126
 127 MSHR*
 128 MSHRQueue::allocate(Packet * &pkt, int size)
 129 {
 130     Addr aligned_addr = pkt->getAddr() & ~((Addr)size - 1);
 131     MSHR *mshr = freeList.front();
 132     assert(mshr->getNumTargets() == 0);
 133     freeList.pop_front();
 134
 135     if (!pkt->needsResponse()) {
 136         mshr->allocateAsBuffer(pkt);
 137     } else {
 138         assert(size !=0);
 139         mshr->allocate(pkt->cmd, aligned_addr, pkt->req->getAsid(), size, pkt);
 140         allocatedTargets += 1;
 141     }
 142     mshr->allocIter = allocatedList.insert(allocatedList.end(), mshr);
 143     mshr->readyIter = pendingList.insert(pendingList.end(), mshr);
 144
 145     allocated += 1;
 146     return mshr;
 147 }
 148
 149 MSHR*
 150 MSHRQueue::allocateFetch(Addr addr, int asid, int size, Packet * &target)
 151 {
 152     MSHR *mshr = freeList.front();
 153     assert(mshr->getNumTargets() == 0);
 154     freeList.pop_front();
 155     mshr->allocate(Packet::ReadReq, addr, asid, size, target);
 156     mshr->allocIter = allocatedList.insert(allocatedList.end(), mshr);
 157     mshr->readyIter = pendingList.insert(pendingList.end(), mshr);
 158
 159     allocated += 1;
 160     return mshr;
 161 }
 162
 163 MSHR*
 164 MSHRQueue::allocateTargetList(Addr addr, int asid, int size)
 165 {
 166     MSHR *mshr = freeList.front();
 167     assert(mshr->getNumTargets() == 0);
 168     freeList.pop_front();
 169     Packet * dummy;
 170     mshr->allocate(Packet::ReadReq, addr, asid, size, dummy);
 171     mshr->allocIter = allocatedList.insert(allocatedList.end(), mshr);
 172     mshr->inService = true;
 173     ++inServiceMSHRs;
 174     ++allocated;
 175     return mshr;
 176 }
 177
 178
 179 void
 180 MSHRQueue::deallocate(MSHR* mshr)
 181 {
 182     deallocateOne(mshr);
 183 }
 184
 185 MSHR::Iterator
 186 MSHRQueue::deallocateOne(MSHR* mshr)
 187 {
 188     MSHR::Iterator retval = allocatedList.erase(mshr->allocIter);
 189     freeList.push_front(mshr);
 190     allocated--;
 191     allocatedTargets -= mshr->getNumTargets();
 192     if (mshr->inService) {
 193         inServiceMSHRs--;
 194     } else {
 195         pendingList.erase(mshr->readyIter);
 196     }
 197     mshr->deallocate();
 198     return retval;
 199 }
 200
 201 void
 202 MSHRQueue::moveToFront(MSHR *mshr)
 203 {
 204     if (!mshr->inService) {
 205         assert(mshr == *(mshr->readyIter));
 206         pendingList.erase(mshr->readyIter);
 207         mshr->readyIter = pendingList.insert(pendingList.begin(), mshr);
 208     }
 209 }
 210
 211 void
 212 MSHRQueue::markInService(MSHR* mshr)
 213 {
 214     //assert(mshr == pendingList.front());
 215     if (!mshr->pkt->needsResponse()) {
 216         assert(mshr->getNumTargets() == 0);
 217         deallocate(mshr);
 218         return;
 219     }
 220     mshr->inService = true;
 221     pendingList.erase(mshr->readyIter);
 222     //mshr->readyIter = NULL;
 223     inServiceMSHRs += 1;
 224     //pendingList.pop_front();
 225 }
 226
 227 void
 228 MSHRQueue::markPending(MSHR* mshr, Packet::Command cmd)
 229 {
 230     //assert(mshr->readyIter == NULL);
 231     mshr->pkt->cmd = cmd;
 232     mshr->pkt->flags &= ~SATISFIED;
 233     mshr->inService = false;
 234     --inServiceMSHRs;
 235     /**
 236      * @ todo might want to add rerequests to front of pending list for
 237      * performance.
 238      */
 239     mshr->readyIter = pendingList.insert(pendingList.end(), mshr);
 240 }
 241
 242 void
 243 MSHRQueue::squash(int threadNum)
 244 {
 245     MSHR::Iterator i = allocatedList.begin();
 246     MSHR::Iterator end = allocatedList.end();
 247     for (; i != end;) {
 248         MSHR *mshr = *i;
 249         if (mshr->threadNum == threadNum) {
 250             while (mshr->hasTargets()) {
 251                 Packet * target = mshr->getTarget();
 252                 mshr->popTarget();
 253
 254                 assert(target->req->getThreadNum() == threadNum);
 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 }