src/dev/net/etherlink.hh

   1 /*
   2  * Copyright (c) 2015 ARM Limited
   3  * All rights reserved
   4  *
   5  * The license below extends only to copyright in the software and shall
   6  * not be construed as granting a license to any other intellectual
   7  * property including but not limited to intellectual property relating
   8  * to a hardware implementation of the functionality of the software
   9  * licensed hereunder.  You may use the software subject to the license
  10  * terms below provided that you ensure that this notice is replicated
  11  * unmodified and in its entirety in all distributions of the software,
  12  * modified or unmodified, in source code or in binary form.
  13  *
  14  * Copyright (c) 2002-2005 The Regents of The University of Michigan
  15  * All rights reserved.
  16  *
  17  * Redistribution and use in source and binary forms, with or without
  18  * modification, are permitted provided that the following conditions are
  19  * met: redistributions of source code must retain the above copyright
  20  * notice, this list of conditions and the following disclaimer;
  21  * redistributions in binary form must reproduce the above copyright
  22  * notice, this list of conditions and the following disclaimer in the
  23  * documentation and/or other materials provided with the distribution;
  24  * neither the name of the copyright holders nor the names of its
  25  * contributors may be used to endorse or promote products derived from
  26  * this software without specific prior written permission.
  27  *
  28  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  29  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  30  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  31  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  32  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  33  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  34  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  35  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  36  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  37  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  38  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  39  */
  40
  41 /* @file
  42  * Device module for modelling a fixed bandwidth full duplex ethernet link
  43  */
  44
  45 #ifndef __DEV_NET_ETHERLINK_HH__
  46 #define __DEV_NET_ETHERLINK_HH__
  47
  48 #include <queue>
  49
  50 #include "base/types.hh"
  51 #include "dev/net/etherint.hh"
  52 #include "dev/net/etherpkt.hh"
  53 #include "params/EtherLink.hh"
  54 #include "sim/eventq.hh"
  55 #include "sim/sim_object.hh"
  56
  57 class EtherDump;
  58 class Checkpoint;
  59 /*
  60  * Model for a fixed bandwidth full duplex ethernet link
  61  */
  62 class EtherLink : public SimObject
  63 {
  64   protected:
  65     class Interface;
  66
  67     /*
  68      * Model for a single uni-directional link
  69      */
  70     class Link
  71     {
  72       protected:
  73         const std::string objName;
  74
  75         EtherLink *const parent;
  76         const int number;
  77
  78         Interface *txint;
  79         Interface *rxint;
  80
  81         const double ticksPerByte;
  82         const Tick linkDelay;
  83         const Tick delayVar;
  84         EtherDump *const dump;
  85
  86       protected:
  87         /*
  88          * Transfer is complete
  89          */
  90         EthPacketPtr packet;
  91         void txDone();
  92         EventFunctionWrapper doneEvent;
  93
  94         /**
  95          * Maintain a queue of in-flight packets. Assume that the
  96          * delay is non-zero and constant (i.e., at most one packet
  97          * per tick).
  98          */
  99         std::deque<std::pair<Tick, EthPacketPtr>> txQueue;
 100
 101         void processTxQueue();
 102         EventFunctionWrapper txQueueEvent;
 103
 104         void txComplete(EthPacketPtr packet);
 105
 106       public:
 107         Link(const std::string &name, EtherLink *p, int num,
 108              double rate, Tick delay, Tick delay_var, EtherDump *dump);
 109         ~Link() {}
 110
 111         const std::string name() const { return objName; }
 112
 113         bool busy() const { return (bool)packet; }
 114         bool transmit(EthPacketPtr packet);
 115
 116         void setTxInt(Interface *i) { assert(!txint); txint = i; }
 117         void setRxInt(Interface *i) { assert(!rxint); rxint = i; }
 118
 119         void serialize(const std::string &base, CheckpointOut &cp) const;
 120         void unserialize(const std::string &base, CheckpointIn &cp);
 121     };
 122
 123     /*
 124      * Interface at each end of the link
 125      */
 126     class Interface : public EtherInt
 127     {
 128       private:
 129         Link *txlink;
 130
 131       public:
 132         Interface(const std::string &name, Link *txlink, Link *rxlink);
 133         bool recvPacket(EthPacketPtr packet) { return txlink->transmit(packet); }
 134         void sendDone() { peer->sendDone(); }
 135         bool isBusy() { return txlink->busy(); }
 136     };
 137
 138     Link *link[2];
 139     Interface *interface[2];
 140
 141   public:
 142     typedef EtherLinkParams Params;
 143     EtherLink(const Params *p);
 144     virtual ~EtherLink();
 145
 146     const Params *
 147     params() const
 148     {
 149         return dynamic_cast<const Params *>(_params);
 150     }
 151
 152     Port &getPort(const std::string &if_name,
 153                   PortID idx=InvalidPortID) override;
 154
 155     void serialize(CheckpointOut &cp) const override;
 156     void unserialize(CheckpointIn &cp) override;
 157
 158 };
 159
 160 #endif // __DEV_NET_ETHERLINK_HH__