external_master.hh revision 10478:7135f938ff28 
1/*
2 * Copyright (c) 2012-2014 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 * 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;
18 * redistributions in binary form must reproduce the above copyright
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
27 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
28 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
29 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
30 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
31 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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35 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36 *
37 * Authors: Andrew Bardsley
38 *          Curtis Dunham
39 */
40
41/**
42 * @file
43 *
44 * ExternalMaster is a memory object representing a binding from
45 * a gem5 slave to a master port in a system external to gem5.
46 *
47 * During initialisation, a `handler' for the port type specified in the
48 * port's port_type parameter is found from the registered port handlers
49 * provided with registerHandler.  Once a handler is found, it is passed the
50 * port_data parameter of the port which can be used to identify the external
51 * port which is to be bound to.  A port handler will usually construct a
52 * bridge object in the external system to accomodate the port-to-port
53 * mapping but this bridge is not exposed to gem5 other than be the
54 * presentation of the MasterPort which can be bound.
55 *
56 * The external port must provide a gem5 MasterPort interface.
57 */
58
59#ifndef __MEM_EXTERNAL_MASTER__
60#define __MEM_EXTERNAL_MASTER__
61
62#include "mem/mem_object.hh"
63#include "params/ExternalMaster.hh"
64
65class ExternalMaster : public MemObject
66{
67  public:
68    /** Derive from this class to create an external port interface */
69    class Port : public MasterPort
70    {
71      protected:
72        ExternalMaster &owner;
73
74      public:
75        Port(const std::string &name_,
76            ExternalMaster &owner_) :
77            MasterPort(name_, &owner_), owner(owner_)
78        { }
79
80        ~Port() { }
81
82        /** Any or all of recv... can be overloaded to provide the port's
83         *  functionality */
84    };
85
86    /* Handlers are specific to *types* of port not specific port
87     * instantiations.  A handler will typically build a bridge to the
88     * external port from gem5 and provide gem5 with a MasterPort that can be
89     * bound to for each call to Handler::getExternalPort.*/
90    class Handler
91    {
92      public:
93        /** Create or find an external port which can be bound.  Returns
94         *  NULL on failure */
95        virtual Port *getExternalPort(
96            const std::string &name, ExternalMaster &owner,
97            const std::string &port_data) = 0;
98    };
99
100  protected:
101    /** The peer port for the gem5 port "port" */
102    Port *externalPort;
103
104    /** Name of the bound port.  This will be name() + ".port" */
105    std::string portName;
106
107    /** Key to select a port handler */
108    std::string portType;
109
110    /** Handler-specific port configuration */
111    std::string portData;
112
113    /** Registered handlers.  Handlers are chosen using the port_type
114     *  parameter on ExternalMasters.  port_types form a global namespace
115     *  across the simulation and so handlers are registered into a global
116     *  structure */
117    static std::map<std::string, Handler *> portHandlers;
118
119  public:
120    ExternalMaster(ExternalMasterParams *params);
121
122    /** MasterPort interface.  Responds only to port "port" */
123    BaseMasterPort &getMasterPort(const std::string &if_name,
124        PortID idx = InvalidPortID);
125
126    /** Register a handler which can provide ports with port_type ==
127     *  handler_name */
128    static void registerHandler(const std::string &handler_name,
129        Handler *handler);
130
131    void init();
132};
133
134
135#endif // __MEM_EXTERNAL_MASTER__
136