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