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 * Authors: Nathan Binkert
41 */
42
43/* @file
44 * Device module for modelling a fixed bandwidth full duplex ethernet link
45 */
46
47#ifndef __DEV_NET_ETHERLINK_HH__
48#define __DEV_NET_ETHERLINK_HH__
49
50#include <queue>
51
52#include "base/types.hh"
53#include "dev/net/etherint.hh"
54#include "dev/net/etherpkt.hh"
55#include "params/EtherLink.hh"
56#include "sim/eventq.hh"
57#include "sim/sim_object.hh"
58
59class EtherDump;
60class Checkpoint;
61/*
62 * Model for a fixed bandwidth full duplex ethernet link
63 */
64class EtherLink : public SimObject
65{
66  protected:
67    class Interface;
68
69    /*
70     * Model for a single uni-directional link
71     */
72    class Link
73    {
74      protected:
75        const std::string objName;
76
77        EtherLink *const parent;
78        const int number;
79
80        Interface *txint;
81        Interface *rxint;
82
83        const double ticksPerByte;
84        const Tick linkDelay;
85        const Tick delayVar;
86        EtherDump *const dump;
87
88      protected:
89        /*
90         * Transfer is complete
91         */
92        EthPacketPtr packet;
93        void txDone();
94        EventFunctionWrapper doneEvent;
95
96        /**
97         * Maintain a queue of in-flight packets. Assume that the
98         * delay is non-zero and constant (i.e., at most one packet
99         * per tick).
100         */
101        std::deque<std::pair<Tick, EthPacketPtr>> txQueue;
102
103        void processTxQueue();
104        EventFunctionWrapper txQueueEvent;
105
106        void txComplete(EthPacketPtr packet);
107
108      public:
109        Link(const std::string &name, EtherLink *p, int num,
110             double rate, Tick delay, Tick delay_var, EtherDump *dump);
111        ~Link() {}
112
113        const std::string name() const { return objName; }
114
115        bool busy() const { return (bool)packet; }
116        bool transmit(EthPacketPtr packet);
117
118        void setTxInt(Interface *i) { assert(!txint); txint = i; }
119        void setRxInt(Interface *i) { assert(!rxint); rxint = i; }
120
121        void serialize(const std::string &base, CheckpointOut &cp) const;
122        void unserialize(const std::string &base, CheckpointIn &cp);
123    };
124
125    /*
126     * Interface at each end of the link
127     */
128    class Interface : public EtherInt
129    {
130      private:
131        Link *txlink;
132
133      public:
134        Interface(const std::string &name, Link *txlink, Link *rxlink);
135        bool recvPacket(EthPacketPtr packet) { return txlink->transmit(packet); }
136        void sendDone() { peer->sendDone(); }
137        bool isBusy() { return txlink->busy(); }
138    };
139
140    Link *link[2];
141    Interface *interface[2];
142
143  public:
144    typedef EtherLinkParams Params;
145    EtherLink(const Params *p);
146    virtual ~EtherLink();
147
148    const Params *
149    params() const
150    {
151        return dynamic_cast<const Params *>(_params);
152    }
153
154    Port &getPort(const std::string &if_name,
155                  PortID idx=InvalidPortID) override;
156
157    void serialize(CheckpointOut &cp) const override;
158    void unserialize(CheckpointIn &cp) override;
159
160};
161
162#endif // __DEV_NET_ETHERLINK_HH__
163