external_slave.hh revision 12492:4e76959883a6 
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
34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
35 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36 *
37 * Authors: Andrew Bardsley
38 */
39
40/**
41 * @file
42 *
43 * ExternalSlave is a memory object representing a binding from
44 * a gem5 master to a slave port in a system external to gem5.
45 *
46 * During initialisation, a `handler' for the port type specified in the
47 * port's port_type parameter is found from the registered port handlers
48 * provided with registerHandler.  Once a handler is found, it is passed the
49 * port_data parameter of the port which can be used to identify the external
50 * port which is to be bound to.  A port handler will usually construct a
51 * bridge object in the external system to accomodate the port-to-port
52 * mapping but this bridge is not exposed to gem5 other than be the
53 * presentation of the SlavePort which can be bound.
54 *
55 * The external port must provide a gem5 SlavePort interface (with the
56 * exception of getAddrRanges which is provided by the ExternalSlave
57 * object).
58 */
59
60#ifndef __MEM_EXTERNAL_SLAVE_HH__
61#define __MEM_EXTERNAL_SLAVE_HH__
62
63#include "mem/mem_object.hh"
64#include "params/ExternalSlave.hh"
65
66class ExternalSlave : public MemObject
67{
68  public:
69    /** Derive from this class to create an external port interface */
70    class Port : public SlavePort
71    {
72      protected:
73        ExternalSlave &owner;
74
75      public:
76        Port(const std::string &name_,
77            ExternalSlave &owner_) :
78            SlavePort(name_, &owner_), owner(owner_)
79        { }
80
81        ~Port() { }
82
83        /** Any or all of recv... can be overloaded to provide the port's
84         *  functionality */
85
86        AddrRangeList getAddrRanges() const;
87    };
88
89    /* Handlers are specific to *types* of port not specific port
90     * instantiations.  A handler will typically build a bridge to the
91     * external port from gem5 and provide gem5 with a SlavePort that can be
92     * bound to for each call to Handler::getExternalPort.*/
93    class Handler
94    {
95      public:
96        /** Create or find an external port which can be bound.  Returns
97         *  NULL on failure */
98        virtual Port *getExternalPort(
99            const std::string &name, ExternalSlave &owner,
100            const std::string &port_data) = 0;
101    };
102
103  protected:
104    /** The peer port for the gem5 port "port" */
105    Port *externalPort;
106
107    /** Name of the bound port.  This will be name() + ".port" */
108    std::string portName;
109
110    /** Key to select a port handler */
111    std::string portType;
112
113    /** Handler-specific port configuration */
114    std::string portData;
115
116    /** The Range of addresses supported by the devices on the external
117     *  side of this port */
118    AddrRangeList addrRanges;
119
120    /** Registered handlers.  Handlers are chosen using the port_type
121     *  parameter on ExternalSlaves.  port_types form a global namespace
122     *  across the simulation and so handlers are registered into a global
123     *  structure */
124    static std::map<std::string, Handler *> portHandlers;
125
126  public:
127    ExternalSlave(ExternalSlaveParams *params);
128
129    /** SlavePort interface.  Responds only to port "port" */
130    BaseSlavePort &getSlavePort(const std::string &if_name,
131        PortID idx = InvalidPortID);
132
133    /** Register a handler which can provide ports with port_type ==
134     *  handler_name */
135    static void registerHandler(const std::string &handler_name,
136        Handler *handler);
137
138    void init();
139};
140
141
142#endif //__MEM_EXTERNAL_SLAVE_HH__
143