src/mem/bus.hh

   1 /*
   2  * Copyright (c) 2002-2005 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 Decleration of a bus object.
  31  */
  32
  33 #ifndef __MEM_BUS_HH__
  34 #define __MEM_BUS_HH__
  35
  36 #include <string>
  37 #include <list>
  38 #include <inttypes.h>
  39
  40 #include "base/range.hh"
  41 #include "mem/mem_object.hh"
  42 #include "mem/packet.hh"
  43 #include "mem/port.hh"
  44 #include "mem/request.hh"
  45
  46 class Bus : public MemObject
  47 {
  48     /** a globally unique id for this bus. */
  49     int busId;
  50
  51     struct DevMap {
  52         int portId;
  53         Range<Addr> range;
  54     };
  55     std::vector<DevMap> portList;
  56
  57
  58     /** Function called by the port when the bus is recieving a Timing
  59         transaction.*/
  60     bool recvTiming(Packet *pkt);
  61
  62     /** Function called by the port when the bus is recieving a Atomic
  63         transaction.*/
  64     Tick recvAtomic(Packet *pkt);
  65
  66     /** Function called by the port when the bus is recieving a Functional
  67         transaction.*/
  68     void recvFunctional(Packet *pkt);
  69
  70     /** Function called by the port when the bus is recieving a status change.*/
  71     void recvStatusChange(Port::Status status, int id);
  72
  73     /** Find which port connected to this bus (if any) should be given a packet
  74      * with this address.
  75      * @param addr Address to find port for.
  76      * @param id Id of the port this packet was received from (to prevent
  77      *             loops)
  78      * @return pointer to port that the packet should be sent out of.
  79      */
  80     Port *findPort(Addr addr, int id);
  81
  82     /** Process address range request.
  83      * @param resp addresses that we can respond to
  84      * @param snoop addresses that we would like to snoop
  85      * @param id ide of the busport that made the request.
  86      */
  87     void addressRanges(AddrRangeList &resp, AddrRangeList &snoop, int id);
  88
  89
  90     /** Decleration of the buses port type, one will be instantiated for each
  91         of the interfaces connecting to the bus. */
  92     class BusPort : public Port
  93     {
  94         /** A pointer to the bus to which this port belongs. */
  95         Bus *bus;
  96
  97         /** A id to keep track of the intercafe ID this port is connected to. */
  98         int id;
  99
 100       public:
 101
 102         /** Constructor for the BusPort.*/
 103         BusPort(Bus *_bus, int _id)
 104             : bus(_bus), id(_id)
 105         { }
 106
 107       protected:
 108
 109         /** When reciving a timing request from the peer port (at id),
 110             pass it to the bus. */
 111         virtual bool recvTiming(Packet *pkt)
 112         { pkt->src = id; return bus->recvTiming(pkt); }
 113
 114         /** When reciving a Atomic requestfrom the peer port (at id),
 115             pass it to the bus. */
 116         virtual Tick recvAtomic(Packet *pkt)
 117         { pkt->src = id; return bus->recvAtomic(pkt); }
 118
 119         /** When reciving a Functional requestfrom the peer port (at id),
 120             pass it to the bus. */
 121         virtual void recvFunctional(Packet *pkt)
 122         { pkt->src = id; bus->recvFunctional(pkt); }
 123
 124         /** When reciving a status changefrom the peer port (at id),
 125             pass it to the bus. */
 126         virtual void recvStatusChange(Status status)
 127         { bus->recvStatusChange(status, id); }
 128
 129         // This should return all the 'owned' addresses that are
 130         // downstream from this bus, yes?  That is, the union of all
 131         // the 'owned' address ranges of all the other interfaces on
 132         // this bus...
 133         virtual void getDeviceAddressRanges(AddrRangeList &resp,
 134                                             AddrRangeList &snoop)
 135         { bus->addressRanges(resp, snoop, id); }
 136
 137         // Hack to make translating port work without changes
 138         virtual int deviceBlockSize() { return 32; }
 139
 140     };
 141
 142     /** An array of pointers to the peer port interfaces
 143         connected to this bus.*/
 144     std::vector<Port*> interfaces;
 145
 146   public:
 147
 148     /** A function used to return the port associated with this bus object. */
 149     virtual Port *getPort(const std::string &if_name)
 150     {
 151         // if_name ignored?  forced to be empty?
 152         int id = interfaces.size();
 153         interfaces.push_back(new BusPort(this, id));
 154         return interfaces.back();
 155     }
 156
 157     virtual void init();
 158
 159     Bus(const std::string &n, int bus_id)
 160         : MemObject(n), busId(bus_id)  {}
 161
 162 };
 163
 164 #endif //__MEM_BUS_HH__