src/mem/bus.cc

   1 /*
   2  * Copyright (c) 2006 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: Ali Saidi
  29  */
  30
  31 /**
  32  * @file
  33  * Definition of a bus object.
  34  */
  35
  36
  37 #include "base/misc.hh"
  38 #include "base/trace.hh"
  39 #include "mem/bus.hh"
  40 #include "sim/builder.hh"
  41
  42 Port *
  43 Bus::getPort(const std::string &if_name, int idx)
  44 {
  45     if (if_name == "default")
  46         if (defaultPort == NULL) {
  47             defaultPort = new BusPort(csprintf("%s-default",name()), this,
  48                     defaultId);
  49             return defaultPort;
  50         } else
  51             fatal("Default port already set\n");
  52
  53     // if_name ignored?  forced to be empty?
  54     int id = interfaces.size();
  55     BusPort *bp = new BusPort(csprintf("%s-p%d", name(), id), this, id);
  56     interfaces.push_back(bp);
  57     return bp;
  58 }
  59
  60 /** Get the ranges of anyone other buses that we are connected to. */
  61 void
  62 Bus::init()
  63 {
  64     std::vector<Port*>::iterator intIter;
  65
  66     for (intIter = interfaces.begin(); intIter != interfaces.end(); intIter++)
  67         (*intIter)->sendStatusChange(Port::RangeChange);
  68 }
  69
  70
  71 /** Function called by the port when the bus is receiving a Timing
  72  * transaction.*/
  73 bool
  74 Bus::recvTiming(Packet *pkt)
  75 {
  76     Port *port;
  77     DPRINTF(Bus, "recvTiming: packet src %d dest %d addr 0x%x cmd %s\n",
  78             pkt->getSrc(), pkt->getDest(), pkt->getAddr(), pkt->cmdString());
  79
  80     short dest = pkt->getDest();
  81     if (dest == Packet::Broadcast) {
  82         port = findPort(pkt->getAddr(), pkt->getSrc());
  83     } else {
  84         assert(dest >= 0 && dest < interfaces.size());
  85         assert(dest != pkt->getSrc()); // catch infinite loops
  86         port = interfaces[dest];
  87     }
  88     if (port->sendTiming(pkt))  {
  89         // packet was successfully sent, just return true.
  90         return true;
  91     }
  92
  93     // packet not successfully sent
  94     retryList.push_back(interfaces[pkt->getSrc()]);
  95     return false;
  96 }
  97
  98 void
  99 Bus::recvRetry(int id)
 100 {
 101     // Go through all the elements on the list calling sendRetry on each
 102     // This is not very efficient at all but it works. Ultimately we should end
 103     // up with something that is more intelligent.
 104     int initialSize = retryList.size();
 105     int i;
 106     Port *p;
 107
 108     for (i = 0; i < initialSize; i++) {
 109         assert(retryList.size() > 0);
 110         p = retryList.front();
 111         retryList.pop_front();
 112         p->sendRetry();
 113     }
 114 }
 115
 116
 117 Port *
 118 Bus::findPort(Addr addr, int id)
 119 {
 120     /* An interval tree would be a better way to do this. --ali. */
 121     int dest_id = -1;
 122     int i = 0;
 123     bool found = false;
 124     AddrRangeIter iter;
 125
 126     while (i < portList.size() && !found)
 127     {
 128         if (portList[i].range == addr) {
 129             dest_id = portList[i].portId;
 130             found = true;
 131             DPRINTF(Bus, "  found addr 0x%llx on device %d\n", addr, dest_id);
 132         }
 133         i++;
 134     }
 135
 136     // Check if this matches the default range
 137     if (dest_id == -1) {
 138         for (iter = defaultRange.begin(); iter != defaultRange.end(); iter++) {
 139             if (*iter == addr) {
 140                 DPRINTF(Bus, "  found addr 0x%llx on default\n", addr);
 141                 return defaultPort;
 142             }
 143         }
 144         panic("Unable to find destination for addr: %llx", addr);
 145     }
 146
 147
 148     // we shouldn't be sending this back to where it came from
 149     assert(dest_id != id);
 150
 151     return interfaces[dest_id];
 152 }
 153
 154 /** Function called by the port when the bus is receiving a Atomic
 155  * transaction.*/
 156 Tick
 157 Bus::recvAtomic(Packet *pkt)
 158 {
 159     DPRINTF(Bus, "recvAtomic: packet src %d dest %d addr 0x%x cmd %s\n",
 160             pkt->getSrc(), pkt->getDest(), pkt->getAddr(), pkt->cmdString());
 161     assert(pkt->getDest() == Packet::Broadcast);
 162     return findPort(pkt->getAddr(), pkt->getSrc())->sendAtomic(pkt);
 163 }
 164
 165 /** Function called by the port when the bus is receiving a Functional
 166  * transaction.*/
 167 void
 168 Bus::recvFunctional(Packet *pkt)
 169 {
 170     DPRINTF(Bus, "recvFunctional: packet src %d dest %d addr 0x%x cmd %s\n",
 171             pkt->getSrc(), pkt->getDest(), pkt->getAddr(), pkt->cmdString());
 172     assert(pkt->getDest() == Packet::Broadcast);
 173     findPort(pkt->getAddr(), pkt->getSrc())->sendFunctional(pkt);
 174 }
 175
 176 /** Function called by the port when the bus is receiving a status change.*/
 177 void
 178 Bus::recvStatusChange(Port::Status status, int id)
 179 {
 180     AddrRangeList ranges;
 181     AddrRangeList snoops;
 182     int x;
 183     AddrRangeIter iter;
 184
 185     assert(status == Port::RangeChange &&
 186            "The other statuses need to be implemented.");
 187
 188     DPRINTF(BusAddrRanges, "received RangeChange from device id %d\n", id);
 189
 190     if (id == defaultId) {
 191         defaultRange.clear();
 192         defaultPort->getPeerAddressRanges(ranges, snoops);
 193         assert(snoops.size() == 0);
 194         for(iter = ranges.begin(); iter != ranges.end(); iter++) {
 195             defaultRange.push_back(*iter);
 196             DPRINTF(BusAddrRanges, "Adding range %llx - %llx for default\n",
 197                     iter->start, iter->end);
 198         }
 199     } else {
 200
 201         assert((id < interfaces.size() && id >= 0) || id == -1);
 202         Port *port = interfaces[id];
 203         std::vector<DevMap>::iterator portIter;
 204
 205         // Clean out any previously existent ids
 206         for (portIter = portList.begin(); portIter != portList.end(); ) {
 207             if (portIter->portId == id)
 208                 portIter = portList.erase(portIter);
 209             else
 210                 portIter++;
 211         }
 212
 213         port->getPeerAddressRanges(ranges, snoops);
 214
 215         // not dealing with snooping yet either
 216         assert(snoops.size() == 0);
 217         for(iter = ranges.begin(); iter != ranges.end(); iter++) {
 218             DevMap dm;
 219             dm.portId = id;
 220             dm.range = *iter;
 221
 222             DPRINTF(BusAddrRanges, "Adding range %llx - %llx for id %d\n",
 223                     dm.range.start, dm.range.end, id);
 224             portList.push_back(dm);
 225         }
 226     }
 227     DPRINTF(MMU, "port list has %d entries\n", portList.size());
 228
 229     // tell all our peers that our address range has changed.
 230     // Don't tell the device that caused this change, it already knows
 231     for (x = 0; x < interfaces.size(); x++)
 232         if (x != id)
 233             interfaces[x]->sendStatusChange(Port::RangeChange);
 234
 235     if (id != defaultId && defaultPort)
 236         defaultPort->sendStatusChange(Port::RangeChange);
 237 }
 238
 239 void
 240 Bus::addressRanges(AddrRangeList &resp, AddrRangeList &snoop, int id)
 241 {
 242     std::vector<DevMap>::iterator portIter;
 243     AddrRangeIter dflt_iter;
 244     bool subset;
 245
 246     resp.clear();
 247     snoop.clear();
 248
 249     DPRINTF(BusAddrRanges, "received address range request, returning:\n");
 250
 251     for (dflt_iter = defaultRange.begin(); dflt_iter != defaultRange.end();
 252             dflt_iter++) {
 253         resp.push_back(*dflt_iter);
 254         DPRINTF(BusAddrRanges, "  -- %#llX : %#llX\n",dflt_iter->start,
 255                 dflt_iter->end);
 256     }
 257     for (portIter = portList.begin(); portIter != portList.end(); portIter++) {
 258         subset = false;
 259         for (dflt_iter = defaultRange.begin(); dflt_iter != defaultRange.end();
 260                 dflt_iter++) {
 261             if ((portIter->range.start < dflt_iter->start &&
 262                 portIter->range.end >= dflt_iter->start) ||
 263                (portIter->range.start < dflt_iter->end &&
 264                 portIter->range.end >= dflt_iter->end))
 265                 fatal("Devices can not set ranges that itersect the default set\
 266                         but are not a subset of the default set.\n");
 267             if (portIter->range.start >= dflt_iter->start &&
 268                 portIter->range.end <= dflt_iter->end) {
 269                 subset = true;
 270                 DPRINTF(BusAddrRanges, "  -- %#llX : %#llX is a SUBSET\n",
 271                     portIter->range.start, portIter->range.end);
 272             }
 273         }
 274         if (portIter->portId != id && !subset) {
 275             resp.push_back(portIter->range);
 276             DPRINTF(BusAddrRanges, "  -- %#llX : %#llX\n",
 277                     portIter->range.start, portIter->range.end);
 278         }
 279     }
 280 }
 281
 282 BEGIN_DECLARE_SIM_OBJECT_PARAMS(Bus)
 283
 284     Param<int> bus_id;
 285
 286 END_DECLARE_SIM_OBJECT_PARAMS(Bus)
 287
 288 BEGIN_INIT_SIM_OBJECT_PARAMS(Bus)
 289     INIT_PARAM(bus_id, "a globally unique bus id")
 290 END_INIT_SIM_OBJECT_PARAMS(Bus)
 291
 292 CREATE_SIM_OBJECT(Bus)
 293 {
 294     return new Bus(getInstanceName(), bus_id);
 295 }
 296
 297 REGISTER_SIM_OBJECT("Bus", Bus)