src/dev/net/dist_packet.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
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   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  * Redistribution and use in source and binary forms, with or without
  15  * modification, are permitted provided that the following conditions are
  16  * met: redistributions of source code must retain the above copyright
  17  * notice, this list of conditions and the following disclaimer;
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  19  * notice, this list of conditions and the following disclaimer in the
  20  * documentation and/or other materials provided with the distribution;
  21  * neither the name of the copyright holders nor the names of its
  22  * contributors may be used to endorse or promote products derived from
  23  * this software without specific prior written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  26  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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  35  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38 /* @file
  39  * Header packet class for dist-gem5 runs.
  40  *
  41  * For a high level description about dist-gem5 see comments in
  42  * header file dist_iface.hh.
  43  *
  44  * The DistHeaderPkt class defines the format of message headers
  45  * sent among gem5 processes during a dist gem5 simulation. A header packet
  46  * can either carry the description of data packet (i.e. a simulated Ethernet
  47  * packet) or a synchronisation related control command. In case of
  48  * data packet description, the corresponding data packet always follows
  49  * the header packet back-to-back.
  50  */
  51 #ifndef __DEV_DIST_PACKET_HH__
  52 #define __DEV_DIST_PACKET_HH__
  53
  54 #include <cstring>
  55
  56 #include "base/types.hh"
  57
  58 class DistHeaderPkt
  59 {
  60   private:
  61     DistHeaderPkt() {}
  62     ~DistHeaderPkt() {}
  63
  64   public:
  65     enum class ReqType { immediate, collective, pending, none };
  66     /**
  67      *  The msg type defines what information a dist header packet carries.
  68      */
  69     enum class MsgType
  70     {
  71         dataDescriptor,
  72         cmdSyncReq,
  73         cmdSyncAck,
  74         unknown
  75     };
  76
  77     struct Header
  78     {
  79         /**
  80          * The msg type field is valid for all header packets.
  81          *
  82          * @note senderRank is used with data packets while collFlags are used
  83          * by sync ack messages to trigger collective ckpt or exit events.
  84          */
  85         MsgType msgType;
  86         Tick sendTick;
  87         /**
  88          * Length used for modeling timing in the simulator.
  89          * (from EthPacketData::simLength).
  90          */
  91         unsigned simLength;
  92         union {
  93             Tick sendDelay;
  94             Tick syncRepeat;
  95         };
  96         union {
  97             /**
  98              * Actual length of the simulated Ethernet packet.
  99              * (from EthPacketData::length).
 100              */
 101             unsigned dataPacketLength;
 102             struct {
 103                 ReqType needCkpt;
 104                 ReqType needStopSync;
 105                 ReqType needExit;
 106             };
 107         };
 108     };
 109 };
 110
 111 #endif