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