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  * Authors: Ron Dreslinski
  29  *          Ali Saidi
  30  */
  31
  32 /**
  33  * @file
  34  * Declaration of a bus object.
  35  */
  36
  37 #ifndef __MEM_BUS_HH__
  38 #define __MEM_BUS_HH__
  39
  40 #include <string>
  41 #include <list>
  42 #include <inttypes.h>
  43
  44 #include "base/range.hh"
  45 #include "mem/mem_object.hh"
  46 #include "mem/packet.hh"
  47 #include "mem/port.hh"
  48 #include "mem/request.hh"
  49
  50 class Bus : public MemObject
  51 {
  52     /** a globally unique id for this bus. */
  53     int busId;
  54
  55     static const int defaultId = -1;
  56
  57     struct DevMap {
  58         int portId;
  59         Range<Addr> range;
  60     };
  61     std::vector<DevMap> portList;
  62     AddrRangeList defaultRange;
  63
  64
  65     /** Function called by the port when the bus is recieving a Timing
  66       transaction.*/
  67     bool recvTiming(Packet *pkt);
  68
  69     /** Function called by the port when the bus is recieving a Atomic
  70       transaction.*/
  71     Tick recvAtomic(Packet *pkt);
  72
  73     /** Function called by the port when the bus is recieving a Functional
  74         transaction.*/
  75     void recvFunctional(Packet *pkt);
  76
  77     /** Timing function called by port when it is once again able to process
  78      * requests. */
  79     void recvRetry(int id);
  80
  81     /** Function called by the port when the bus is recieving a status change.*/
  82     void recvStatusChange(Port::Status status, int id);
  83
  84     /** Find which port connected to this bus (if any) should be given a packet
  85      * with this address.
  86      * @param addr Address to find port for.
  87      * @param id Id of the port this packet was received from (to prevent
  88      *             loops)
  89      * @return pointer to port that the packet should be sent out of.
  90      */
  91     Port *findPort(Addr addr, int id);
  92
  93     /** Process address range request.
  94      * @param resp addresses that we can respond to
  95      * @param snoop addresses that we would like to snoop
  96      * @param id ide of the busport that made the request.
  97      */
  98     void addressRanges(AddrRangeList &resp, AddrRangeList &snoop, int id);
  99
 100
 101     /** Declaration of the buses port type, one will be instantiated for each
 102         of the interfaces connecting to the bus. */
 103     class BusPort : public Port
 104     {
 105         /** A pointer to the bus to which this port belongs. */
 106         Bus *bus;
 107
 108         /** A id to keep track of the intercafe ID this port is connected to. */
 109         int id;
 110
 111       public:
 112
 113         /** Constructor for the BusPort.*/
 114         BusPort(const std::string &_name, Bus *_bus, int _id)
 115             : Port(_name), bus(_bus), id(_id)
 116         { }
 117
 118       protected:
 119
 120         /** When reciving a timing request from the peer port (at id),
 121             pass it to the bus. */
 122         virtual bool recvTiming(Packet *pkt)
 123         { pkt->setSrc(id); return bus->recvTiming(pkt); }
 124
 125         /** When reciving a Atomic requestfrom the peer port (at id),
 126             pass it to the bus. */
 127         virtual Tick recvAtomic(Packet *pkt)
 128         { pkt->setSrc(id); return bus->recvAtomic(pkt); }
 129
 130         /** When reciving a Functional requestfrom the peer port (at id),
 131             pass it to the bus. */
 132         virtual void recvFunctional(Packet *pkt)
 133         { pkt->setSrc(id); bus->recvFunctional(pkt); }
 134
 135         /** When reciving a status changefrom the peer port (at id),
 136             pass it to the bus. */
 137         virtual void recvStatusChange(Status status)
 138         { bus->recvStatusChange(status, id); }
 139
 140         /** When reciving a retry from the peer port (at id),
 141             pass it to the bus. */
 142         virtual void recvRetry()
 143         { bus->recvRetry(id); }
 144
 145         // This should return all the 'owned' addresses that are
 146         // downstream from this bus, yes?  That is, the union of all
 147         // the 'owned' address ranges of all the other interfaces on
 148         // this bus...
 149         virtual void getDeviceAddressRanges(AddrRangeList &resp,
 150                                             AddrRangeList &snoop)
 151         { bus->addressRanges(resp, snoop, id); }
 152
 153         // Hack to make translating port work without changes
 154         virtual int deviceBlockSize() { return 32; }
 155
 156     };
 157
 158     /** An array of pointers to the peer port interfaces
 159         connected to this bus.*/
 160     std::vector<Port*> interfaces;
 161
 162     /** An array of pointers to ports that retry should be called on because the
 163      * original send failed for whatever reason.*/
 164     std::list<Port*> retryList;
 165
 166     /** Port that handles requests that don't match any of the interfaces.*/
 167     Port *defaultPort;
 168
 169   public:
 170
 171     /** A function used to return the port associated with this bus object. */
 172     virtual Port *getPort(const std::string &if_name, int idx = -1);
 173
 174     virtual void init();
 175
 176     Bus(const std::string &n, int bus_id)
 177         : MemObject(n), busId(bus_id), defaultPort(NULL)  {}
 178
 179 };
 180
 181 #endif //__MEM_BUS_HH__