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