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/*
* Copyright (c) 2012-2014 ARM Limited
* All rights reserved
*
* The license below extends only to copyright in the software and shall
* not be construed as granting a license to any other intellectual
* property including but not limited to intellectual property relating
* to a hardware implementation of the functionality of the software
* licensed hereunder. You may use the software subject to the license
* terms below provided that you ensure that this notice is replicated
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* modified or unmodified, in source code or in binary form.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
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* redistributions in binary form must reproduce the above copyright
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* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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*/
/**
* @file
*
* ExternalMaster is a memory object representing a binding from
* a gem5 responder to a request port in a system external to gem5.
*
* During initialisation, a `handler' for the port type specified in the
* port's port_type parameter is found from the registered port handlers
* provided with registerHandler. Once a handler is found, it is passed the
* port_data parameter of the port which can be used to identify the external
* port which is to be bound to. A port handler will usually construct a
* bridge object in the external system to accomodate the port-to-port
* mapping but this bridge is not exposed to gem5 other than be the
* presentation of the RequestPort which can be bound.
*
* The external port must provide a gem5 RequestPort interface.
*/
#ifndef __MEM_EXTERNAL_MASTER_HH__
#define __MEM_EXTERNAL_MASTER_HH__
#include "mem/port.hh"
#include "params/ExternalMaster.hh"
#include "sim/sim_object.hh"
namespace gem5
{
class ExternalMaster : public SimObject
{
public:
/** Derive from this class to create an external port interface */
class ExternalPort : public RequestPort
{
protected:
ExternalMaster &owner;
public:
ExternalPort(const std::string &name_,
ExternalMaster &owner_) :
RequestPort(name_), owner(owner_)
{ }
~ExternalPort() { }
/** Any or all of recv... can be overloaded to provide the port's
* functionality */
};
/* Handlers are specific to *types* of port not specific port
* instantiations. A handler will typically build a bridge to the
* external port from gem5 and provide gem5 with a RequestPort that can be
* bound to for each call to Handler::getExternalPort.*/
class Handler
{
public:
/** Create or find an external port which can be bound. Returns
* NULL on failure */
virtual ExternalPort *getExternalPort(
const std::string &name, ExternalMaster &owner,
const std::string &port_data) = 0;
};
protected:
/** The peer port for the gem5 port "port" */
ExternalPort *externalPort;
/** Name of the bound port. This will be name() + ".port" */
std::string portName;
/** Key to select a port handler */
std::string portType;
/** Handler-specific port configuration */
std::string portData;
/** Registered handlers. Handlers are chosen using the port_type
* parameter on ExternalMasters. port_types form a global namespace
* across the simulation and so handlers are registered into a global
* structure */
static std::map<std::string, Handler *> portHandlers;
public:
ExternalMaster(const ExternalMasterParams &params);
/** Port interface. Responds only to port "port" */
Port &getPort(const std::string &if_name,
PortID idx=InvalidPortID) override;
/** Register a handler which can provide ports with port_type ==
* handler_name */
static void registerHandler(const std::string &handler_name,
Handler *handler);
void init() override;
const RequestorID id;
};
} // namespace gem5
#endif //__MEM_EXTERNAL_MASTER_HH__