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/*
* 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.
*/
/**
* @file
* Port Object Declaration.
*/
#ifndef __MEM_PORT_HH__
#define __MEM_PORT_HH__
#include "base/addr_range.hh"
#include "mem/packet.hh"
#include "mem/protocol/atomic.hh"
#include "mem/protocol/functional.hh"
#include "mem/protocol/timing.hh"
#include "sim/port.hh"
namespace gem5
{
class SimObject;
/** Forward declaration */
class MasterPort;
class SlavePort;
class ResponsePort;
/**
* A RequestPort is a specialisation of a Port, 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.
*
* The three protocols are atomic, timing, and functional, each with its own
* header file.
*/
class RequestPort: public Port, public AtomicRequestProtocol,
public TimingRequestProtocol, public FunctionalRequestProtocol
{
friend class ResponsePort;
private:
ResponsePort *_responsePort;
protected:
SimObject &owner;
public:
[[deprecated("RequestPort ownership is deprecated. "
"Owner should now be registered in derived classes.")]]
RequestPort(const std::string& name, SimObject* _owner,
PortID id=InvalidPortID);
RequestPort(const std::string& name, PortID id=InvalidPortID);
virtual ~RequestPort();
/**
* Bind this request port to a response port. This also does the
* mirror action and binds the response port to the request port.
*/
void bind(Port &peer) override;
/**
* Unbind this request port and the associated response port.
*/
void unbind() override;
/**
* Determine if this request port is snooping or not. The default
* implementation returns false and thus tells the neighbour we
* are not snooping. Any request 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 responder 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);
public:
/* The atomic protocol. */
/**
* 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);
public:
/* The functional protocol. */
/**
* 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) const;
/**
* Send a request for a back door to a range of memory.
*
* @param req An object which describes what back door is being requested.
* @param backdoor Can be set to a back door pointer by the target to let
* caller have direct access to the requested range. The original
* caller should initialize this pointer to nullptr. If a receiver
* does not want to provide a back door, they should leave this
* value. If an intermediary wants to support a back door across it,
* it should pass this pointer through, or if not, return without
* passing the request further downstream.
*/
void sendMemBackdoorReq(const MemBackdoorReq &req,
MemBackdoorPtr &backdoor);
public:
/* The timing protocol. */
/**
* Attempt to send a timing request to the responder 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 responder 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 successful or not.
*/
bool tryTiming(PacketPtr pkt) const;
/**
* Attempt to send a timing snoop response packet to the response
* 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 response port that previously attempted a
* sendTimingResp to this request 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();
protected:
/**
* Called to receive an address range change from the peer response
* 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() { }
/**
* Default implementations.
*/
Tick
recvAtomicSnoop(PacketPtr pkt) override
{
panic("%s was not expecting an atomic snoop request\n", name());
return 0;
}
void
recvFunctionalSnoop(PacketPtr pkt) override
{
panic("%s was not expecting a functional snoop request\n", name());
}
void
recvTimingSnoopReq(PacketPtr pkt) override
{
panic("%s was not expecting a timing snoop request.\n", name());
}
void
recvRetrySnoopResp() override
{
panic("%s was not expecting a snoop retry.\n", name());
}
};
class [[deprecated]] MasterPort : public RequestPort
{
public:
using RequestPort::RequestPort;
};
/**
* A ResponsePort is a specialization of a port. In addition to the
* basic functionality of sending packets to its requestor peer, it also
* has functions specific to a responder, e.g. to send range changes
* and get the address ranges that the port responds to.
*
* The three protocols are atomic, timing, and functional, each with its own
* header file.
*/
class ResponsePort : public Port, public AtomicResponseProtocol,
public TimingResponseProtocol, public FunctionalResponseProtocol
{
friend class RequestPort;
private:
RequestPort* _requestPort;
bool defaultBackdoorWarned;
protected:
SimObject& owner;
public:
[[deprecated("ResponsePort ownership is deprecated. "
"Owner should now be registered in derived classes.")]]
ResponsePort(const std::string& name, SimObject* _owner,
PortID id=InvalidPortID);
ResponsePort(const std::string& name, PortID id=InvalidPortID);
virtual ~ResponsePort();
/**
* Find out if the peer request port is snooping or not.
*
* @return true if the peer request port is snooping
*/
bool isSnooping() const { return _requestPort->isSnooping(); }
/**
* Called by the owner to send a range change
*/
void sendRangeChange() const { _requestPort->recvRangeChange(); }
/**
* Get a list of the non-overlapping address ranges the owner is
* responsible for. All response 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 request port do the work, so these don't do anything.
*/
void unbind() override {}
void bind(Port &peer) override {}
public:
/* The atomic protocol. */
/**
* 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)
{
try {
return AtomicResponseProtocol::sendSnoop(_requestPort, pkt);
} catch (UnboundPortException) {
reportUnbound();
}
}
public:
/* The functional protocol. */
/**
* 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) const
{
try {
FunctionalResponseProtocol::sendSnoop(_requestPort, pkt);
} catch (UnboundPortException) {
reportUnbound();
}
}
public:
/* The timing protocol. */
/**
* Attempt to send a timing response to the request 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 successful or not.
*/
bool
sendTimingResp(PacketPtr pkt)
{
try {
return TimingResponseProtocol::sendResp(_requestPort, pkt);
} catch (UnboundPortException) {
reportUnbound();
}
}
/**
* Attempt to send a timing snoop request packet to the request 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)
{
try {
TimingResponseProtocol::sendSnoopReq(_requestPort, pkt);
} catch (UnboundPortException) {
reportUnbound();
}
}
/**
* Send a retry to the request port that previously attempted a
* sendTimingReq to this response port and failed.
*/
void
sendRetryReq()
{
try {
TimingResponseProtocol::sendRetryReq(_requestPort);
} catch (UnboundPortException) {
reportUnbound();
}
}
/**
* Send a retry to the request port that previously attempted a
* sendTimingSnoopResp to this response port and failed.
*/
void
sendRetrySnoopResp()
{
try {
TimingResponseProtocol::sendRetrySnoopResp(_requestPort);
} catch (UnboundPortException) {
reportUnbound();
}
}
protected:
/**
* Called by the request port to unbind. Should never be called
* directly.
*/
void responderUnbind();
/**
* Called by the request port to bind. Should never be called
* directly.
*/
void responderBind(RequestPort& request_port);
/**
* Default implementations.
*/
Tick recvAtomicBackdoor(PacketPtr pkt, MemBackdoorPtr &backdoor) override;
void recvMemBackdoorReq(const MemBackdoorReq &req,
MemBackdoorPtr &backdoor) override;
bool
tryTiming(PacketPtr pkt) override
{
panic("%s was not expecting a %s\n", name(), __func__);
}
bool
recvTimingSnoopResp(PacketPtr pkt) override
{
panic("%s was not expecting a timing snoop response\n", name());
}
};
class [[deprecated]] SlavePort : public ResponsePort
{
public:
using ResponsePort::ResponsePort;
};
inline Tick
RequestPort::sendAtomic(PacketPtr pkt)
{
try {
return AtomicRequestProtocol::send(_responsePort, pkt);
} catch (UnboundPortException) {
reportUnbound();
}
}
inline Tick
RequestPort::sendAtomicBackdoor(PacketPtr pkt, MemBackdoorPtr &backdoor)
{
try {
return AtomicRequestProtocol::sendBackdoor(_responsePort,
pkt, backdoor);
} catch (UnboundPortException) {
reportUnbound();
}
}
inline void
RequestPort::sendFunctional(PacketPtr pkt) const
{
try {
return FunctionalRequestProtocol::send(_responsePort, pkt);
} catch (UnboundPortException) {
reportUnbound();
}
}
inline void
RequestPort::sendMemBackdoorReq(const MemBackdoorReq &req,
MemBackdoorPtr &backdoor)
{
try {
return FunctionalRequestProtocol::sendMemBackdoorReq(
_responsePort, req, backdoor);
} catch (UnboundPortException) {
reportUnbound();
}
}
inline bool
RequestPort::sendTimingReq(PacketPtr pkt)
{
try {
return TimingRequestProtocol::sendReq(_responsePort, pkt);
} catch (UnboundPortException) {
reportUnbound();
}
}
inline bool
RequestPort::tryTiming(PacketPtr pkt) const
{
try {
return TimingRequestProtocol::trySend(_responsePort, pkt);
} catch (UnboundPortException) {
reportUnbound();
}
}
inline bool
RequestPort::sendTimingSnoopResp(PacketPtr pkt)
{
try {
return TimingRequestProtocol::sendSnoopResp(_responsePort, pkt);
} catch (UnboundPortException) {
reportUnbound();
}
}
inline void
RequestPort::sendRetryResp()
{
try {
TimingRequestProtocol::sendRetryResp(_responsePort);
} catch (UnboundPortException) {
reportUnbound();
}
}
} // namespace gem5
#endif //__MEM_PORT_HH__