/*
* Copyright (c) 2011-2012,2015,2017 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
* unmodified and in its entirety in all distributions of the software,
* modified or unmodified, in source code or in binary form.
*
* Copyright (c) 2002-2005 The Regents of The University of Michigan
* All rights reserved.
*
* 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
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* 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
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Authors: Ron Dreslinski
* Andreas Hansson
* William Wang
*/
/**
* @file
* Port Object Declaration.
*/
#ifndef __MEM_PORT_HH__
#define __MEM_PORT_HH__
#include "base/addr_range.hh"
#include "mem/backdoor.hh"
#include "mem/packet.hh"
#include "sim/port.hh"
class SimObject;
/** Forward declaration */
class BaseSlavePort;
/**
* A BaseMasterPort is a protocol-agnostic master port, responsible
* only for the structural connection to a slave port. The final
* master port that inherits from the base class must override the
* bind member function for the specific slave port class.
*/
class BaseMasterPort : public Port
{
protected:
BaseSlavePort* _baseSlavePort;
BaseMasterPort(const std::string& name, PortID id=InvalidPortID);
virtual ~BaseMasterPort();
public:
BaseSlavePort& getSlavePort() const;
};
/**
* A BaseSlavePort is a protocol-agnostic slave port, responsible
* only for the structural connection to a master port.
*/
class BaseSlavePort : public Port
{
protected:
BaseMasterPort* _baseMasterPort;
BaseSlavePort(const std::string& name, PortID id=InvalidPortID);
virtual ~BaseSlavePort();
public:
BaseMasterPort& getMasterPort() const;
};
/** Forward declaration */
class SlavePort;
/**
* A MasterPort is a specialisation of a BaseMasterPort, which
* implements the default protocol for the three different level of
* transport functions. In addition to the basic functionality of
* sending packets, it also has functions to receive range changes or
* determine if the port is snooping or not.
*/
class MasterPort : public BaseMasterPort
{
friend class SlavePort;
private:
SlavePort* _slavePort;
protected:
SimObject& owner;
public:
MasterPort(const std::string& name, SimObject* _owner,
PortID id=InvalidPortID);
virtual ~MasterPort();
/**
* Bind this master port to a slave port. This also does the
* mirror action and binds the slave port to the master port.
*/
void bind(Port &peer) override;
/**
* Unbind this master port and the associated slave port.
*/
void unbind() override;
/**
* Send an atomic request packet, where the data is moved and the
* state is updated in zero time, without interleaving with other
* memory accesses.
*
* @param pkt Packet to send.
*
* @return Estimated latency of access.
*/
Tick sendAtomic(PacketPtr pkt);
/**
* Send an atomic request packet like above, but also request a backdoor
* to the data being accessed.
*
* @param pkt Packet to send.
* @param backdoor Can be set to a back door pointer by the target to let
* caller have direct access to the requested data.
*
* @return Estimated latency of access.
*/
Tick sendAtomicBackdoor(PacketPtr pkt, MemBackdoorPtr &backdoor);
/**
* Send a functional request packet, where the data is instantly
* updated everywhere in the memory system, without affecting the
* current state of any block or moving the block.
*
* @param pkt Packet to send.
*/
void sendFunctional(PacketPtr pkt);
/**
* Attempt to send a timing request to the slave port by calling
* its corresponding receive function. If the send does not
* succeed, as indicated by the return value, then the sender must
* wait for a recvReqRetry at which point it can re-issue a
* sendTimingReq.
*
* @param pkt Packet to send.
*
* @return If the send was succesful or not.
*/
bool sendTimingReq(PacketPtr pkt);
/**
* Check if the slave can handle a timing request.
*
* If the send cannot be handled at the moment, as indicated by
* the return value, then the sender will receive a recvReqRetry
* at which point it can re-issue a sendTimingReq.
*
* @param pkt Packet to send.
*
* @return If the send was succesful or not.
*/
bool tryTiming(PacketPtr pkt) const;
/**
* Attempt to send a timing snoop response packet to the slave
* port by calling its corresponding receive function. If the send
* does not succeed, as indicated by the return value, then the
* sender must wait for a recvRetrySnoop at which point it can
* re-issue a sendTimingSnoopResp.
*
* @param pkt Packet to send.
*/
bool sendTimingSnoopResp(PacketPtr pkt);
/**
* Send a retry to the slave port that previously attempted a
* sendTimingResp to this master port and failed. Note that this
* is virtual so that the "fake" snoop response port in the
* coherent crossbar can override the behaviour.
*/
virtual void sendRetryResp();
/**
* Determine if this master port is snooping or not. The default
* implementation returns false and thus tells the neighbour we
* are not snooping. Any master port that wants to receive snoop
* requests (e.g. a cache connected to a bus) has to override this
* function.
*
* @return true if the port should be considered a snooper
*/
virtual bool isSnooping() const { return false; }
/**
* Get the address ranges of the connected slave port.
*/
AddrRangeList getAddrRanges() const;
/** Inject a PrintReq for the given address to print the state of
* that address throughout the memory system. For debugging.
*/
void printAddr(Addr a);
protected:
/**
* Receive an atomic snoop request packet from the slave port.
*/
virtual Tick recvAtomicSnoop(PacketPtr pkt)
{
panic("%s was not expecting an atomic snoop request\n", name());
return 0;
}
/**
* Receive a functional snoop request packet from the slave port.
*/
virtual void recvFunctionalSnoop(PacketPtr pkt)
{
panic("%s was not expecting a functional snoop request\n", name());
}
/**
* Receive a timing response from the slave port.
*/
virtual bool recvTimingResp(PacketPtr pkt) = 0;
/**
* Receive a timing snoop request from the slave port.
*/
virtual void recvTimingSnoopReq(PacketPtr pkt)
{
panic("%s was not expecting a timing snoop request\n", name());
}
/**
* Called by the slave port if sendTimingReq was called on this
* master port (causing recvTimingReq to be called on the slave
* port) and was unsuccesful.
*/
virtual void recvReqRetry() = 0;
/**
* Called by the slave port if sendTimingSnoopResp was called on this
* master port (causing recvTimingSnoopResp to be called on the slave
* port) and was unsuccesful.
*/
virtual void recvRetrySnoopResp()
{
panic("%s was not expecting a snoop retry\n", name());
}
/**
* Called to receive an address range change from the peer slave
* port. The default implementation ignores the change and does
* nothing. Override this function in a derived class if the owner
* needs to be aware of the address ranges, e.g. in an
* interconnect component like a bus.
*/
virtual void recvRangeChange() { }
};
/**
* A SlavePort is a specialisation of a port. In addition to the
* basic functionality of sending packets to its master peer, it also
* has functions specific to a slave, e.g. to send range changes
* and get the address ranges that the port responds to.
*/
class SlavePort : public BaseSlavePort
{
friend class MasterPort;
private:
MasterPort* _masterPort;
bool defaultBackdoorWarned;
protected:
SimObject& owner;
public:
SlavePort(const std::string& name, SimObject* _owner,
PortID id=InvalidPortID);
virtual ~SlavePort();
/**
* Send an atomic snoop request packet, where the data is moved
* and the state is updated in zero time, without interleaving
* with other memory accesses.
*
* @param pkt Snoop packet to send.
*
* @return Estimated latency of access.
*/
Tick sendAtomicSnoop(PacketPtr pkt);
/**
* Send a functional snoop request packet, where the data is
* instantly updated everywhere in the memory system, without
* affecting the current state of any block or moving the block.
*
* @param pkt Snoop packet to send.
*/
void sendFunctionalSnoop(PacketPtr pkt);
/**
* Attempt to send a timing response to the master port by calling
* its corresponding receive function. If the send does not
* succeed, as indicated by the return value, then the sender must
* wait for a recvRespRetry at which point it can re-issue a
* sendTimingResp.
*
* @param pkt Packet to send.
*
* @return If the send was succesful or not.
*/
bool sendTimingResp(PacketPtr pkt);
/**
* Attempt to send a timing snoop request packet to the master port
* by calling its corresponding receive function. Snoop requests
* always succeed and hence no return value is needed.
*
* @param pkt Packet to send.
*/
void sendTimingSnoopReq(PacketPtr pkt);
/**
* Send a retry to the master port that previously attempted a
* sendTimingReq to this slave port and failed.
*/
void sendRetryReq();
/**
* Send a retry to the master port that previously attempted a
* sendTimingSnoopResp to this slave port and failed.
*/
void sendRetrySnoopResp();
/**
* Find out if the peer master port is snooping or not.
*
* @return true if the peer master port is snooping
*/
bool isSnooping() const { return _masterPort->isSnooping(); }
/**
* Called by the owner to send a range change
*/
void sendRangeChange() const {
if (!_masterPort)
fatal("%s cannot sendRangeChange() without master port", name());
_masterPort->recvRangeChange();
}
/**
* Get a list of the non-overlapping address ranges the owner is
* responsible for. All slave ports must override this function
* and return a populated list with at least one item.
*
* @return a list of ranges responded to
*/
virtual AddrRangeList getAddrRanges() const = 0;
/**
* We let the master port do the work, so these don't do anything.
*/
void unbind() override {}
void bind(Port &peer) override {}
protected:
/**
* Called by the master port to unbind. Should never be called
* directly.
*/
void slaveUnbind();
/**
* Called by the master port to bind. Should never be called
* directly.
*/
void slaveBind(MasterPort& master_port);
/**
* Receive an atomic request packet from the master port.
*/
virtual Tick recvAtomic(PacketPtr pkt) = 0;
/**
* Receive an atomic request packet from the master port, and optionally
* provide a backdoor to the data being accessed.
*/
virtual Tick recvAtomicBackdoor(PacketPtr pkt, MemBackdoorPtr &backdoor);
/**
* Receive a functional request packet from the master port.
*/
virtual void recvFunctional(PacketPtr pkt) = 0;
/**
* Receive a timing request from the master port.
*/
virtual bool recvTimingReq(PacketPtr pkt) = 0;
/**
* Availability request from the master port.
*/
virtual bool tryTiming(PacketPtr pkt) {
panic("%s was not expecting a %s\n", name(), __func__);
}
/**
* Receive a timing snoop response from the master port.
*/
virtual bool recvTimingSnoopResp(PacketPtr pkt)
{
panic("%s was not expecting a timing snoop response\n", name());
}
/**
* Called by the master port if sendTimingResp was called on this
* slave port (causing recvTimingResp to be called on the master
* port) and was unsuccesful.
*/
virtual void recvRespRetry() = 0;
};
#endif //__MEM_PORT_HH__