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     return port->sendTiming(pkt);
  76 }
  77
  78 Port *
  79 Bus::findPort(Addr addr, int id)
  80 {
  81     /* An interval tree would be a better way to do this. --ali. */
  82     int dest_id = -1;
  83     int i = 0;
  84     bool found = false;
  85
  86     while (i < portList.size() && !found)
  87     {
  88         if (portList[i].range == addr) {
  89             dest_id = portList[i].portId;
  90             found = true;
  91             DPRINTF(Bus, "  found addr 0x%llx on device %d\n", addr, dest_id);
  92         }
  93         i++;
  94     }
  95     if (dest_id == -1)
  96         panic("Unable to find destination for addr: %llx", addr);
  97
  98     // we shouldn't be sending this back to where it came from
  99     assert(dest_id != id);
 100
 101     return interfaces[dest_id];
 102 }
 103
 104 /** Function called by the port when the bus is receiving a Atomic
 105  * transaction.*/
 106 Tick
 107 Bus::recvAtomic(Packet *pkt)
 108 {
 109     DPRINTF(Bus, "recvAtomic: packet src %d dest %d addr 0x%x cmd %s\n",
 110             pkt->getSrc(), pkt->getDest(), pkt->getAddr(), pkt->cmdString());
 111     assert(pkt->getDest() == Packet::Broadcast);
 112     return findPort(pkt->getAddr(), pkt->getSrc())->sendAtomic(pkt);
 113 }
 114
 115 /** Function called by the port when the bus is receiving a Functional
 116  * transaction.*/
 117 void
 118 Bus::recvFunctional(Packet *pkt)
 119 {
 120     DPRINTF(Bus, "recvFunctional: packet src %d dest %d addr 0x%x cmd %s\n",
 121             pkt->getSrc(), pkt->getDest(), pkt->getAddr(), pkt->cmdString());
 122     assert(pkt->getDest() == Packet::Broadcast);
 123     findPort(pkt->getAddr(), pkt->getSrc())->sendFunctional(pkt);
 124 }
 125
 126 /** Function called by the port when the bus is receiving a status change.*/
 127 void
 128 Bus::recvStatusChange(Port::Status status, int id)
 129 {
 130     assert(status == Port::RangeChange &&
 131            "The other statuses need to be implemented.");
 132
 133     DPRINTF(BusAddrRanges, "received RangeChange from device id %d\n", id);
 134
 135     assert(id < interfaces.size() && id >= 0);
 136     int x;
 137     Port *port = interfaces[id];
 138     AddrRangeList ranges;
 139     AddrRangeList snoops;
 140     AddrRangeIter iter;
 141     std::vector<DevMap>::iterator portIter;
 142
 143     // Clean out any previously existent ids
 144     for (portIter = portList.begin(); portIter != portList.end(); ) {
 145         if (portIter->portId == id)
 146             portIter = portList.erase(portIter);
 147         else
 148             portIter++;
 149     }
 150
 151     port->getPeerAddressRanges(ranges, snoops);
 152
 153     // not dealing with snooping yet either
 154     assert(snoops.size() == 0);
 155     for(iter = ranges.begin(); iter != ranges.end(); iter++) {
 156         DevMap dm;
 157         dm.portId = id;
 158         dm.range = *iter;
 159
 160         DPRINTF(BusAddrRanges, "Adding range %llx - %llx for id %d\n",
 161                 dm.range.start, dm.range.end, id);
 162         portList.push_back(dm);
 163     }
 164     DPRINTF(MMU, "port list has %d entries\n", portList.size());
 165
 166     // tell all our peers that our address range has changed.
 167     // Don't tell the device that caused this change, it already knows
 168     for (x = 0; x < interfaces.size(); x++)
 169         if (x != id)
 170             interfaces[x]->sendStatusChange(Port::RangeChange);
 171 }
 172
 173 void
 174 Bus::addressRanges(AddrRangeList &resp, AddrRangeList &snoop, int id)
 175 {
 176     std::vector<DevMap>::iterator portIter;
 177
 178     resp.clear();
 179     snoop.clear();
 180
 181     DPRINTF(BusAddrRanges, "received address range request, returning:\n");
 182     for (portIter = portList.begin(); portIter != portList.end(); portIter++) {
 183         if (portIter->portId != id) {
 184             resp.push_back(portIter->range);
 185             DPRINTF(BusAddrRanges, "  -- %#llX : %#llX\n",
 186                     portIter->range.start, portIter->range.end);
 187         }
 188     }
 189 }
 190
 191 BEGIN_DECLARE_SIM_OBJECT_PARAMS(Bus)
 192
 193     Param<int> bus_id;
 194
 195 END_DECLARE_SIM_OBJECT_PARAMS(Bus)
 196
 197 BEGIN_INIT_SIM_OBJECT_PARAMS(Bus)
 198     INIT_PARAM(bus_id, "a globally unique bus id")
 199 END_INIT_SIM_OBJECT_PARAMS(Bus)
 200
 201 CREATE_SIM_OBJECT(Bus)
 202 {
 203     return new Bus(getInstanceName(), bus_id);
 204 }
 205
 206 REGISTER_SIM_OBJECT("Bus", Bus)