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