gem5/src/mem/mem_checker_monitor.hh
Andreas Hansson f26a289295 mem: Split port retry for all different packet classes
This patch fixes a long-standing isue with the port flow
control. Before this patch the retry mechanism was shared between all
different packet classes. As a result, a snoop response could get
stuck behind a request waiting for a retry, even if the send/recv
functions were split. This caused message-dependent deadlocks in
stress-test scenarios.

The patch splits the retry into one per packet (message) class. Thus,
sendTimingReq has a corresponding recvReqRetry, sendTimingResp has
recvRespRetry etc. Most of the changes to the code involve simply
clarifying what type of request a specific object was accepting.

The biggest change in functionality is in the cache downstream packet
queue, facing the memory. This queue was shared by requests and snoop
responses, and it is now split into two queues, each with their own
flow control, but the same physical MasterPort. These changes fixes
the previously seen deadlocks.
2015-03-02 04:00:35 -05:00

241 lines
6.5 KiB
C++

/*
* 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
* unmodified and in its entirety in all distributions of the software,
* 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
* 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: Thomas Grass
* Andreas Hansson
* Marco Elver
*/
#ifndef __MEM_MEM_CHECKER_MONITOR_HH__
#define __MEM_MEM_CHECKER_MONITOR_HH__
#include "base/statistics.hh"
#include "mem/mem_checker.hh"
#include "mem/mem_object.hh"
#include "params/MemCheckerMonitor.hh"
#include "sim/system.hh"
/**
* Implements a MemChecker monitor, to be inserted between two ports.
*/
class MemCheckerMonitor : public MemObject
{
public:
/** Parameters of memchecker monitor */
typedef MemCheckerMonitorParams Params;
const Params* params() const
{ return reinterpret_cast<const Params*>(_params); }
/**
* Constructor based on the Python params
*
* @param params Python parameters
*/
MemCheckerMonitor(Params* params);
/** Destructor */
~MemCheckerMonitor();
virtual BaseMasterPort& getMasterPort(const std::string& if_name,
PortID idx = InvalidPortID);
virtual BaseSlavePort& getSlavePort(const std::string& if_name,
PortID idx = InvalidPortID);
virtual void init();
private:
struct MemCheckerMonitorSenderState : public Packet::SenderState
{
MemCheckerMonitorSenderState(MemChecker::Serial _serial)
: serial(_serial)
{}
MemChecker::Serial serial;
};
/**
* This is the master port of the communication monitor. All recv
* functions call a function in MemCheckerMonitor, where the
* send function of the slave port is called. Besides this, these
* functions can also perform actions for capturing statistics.
*/
class MonitorMasterPort : public MasterPort
{
public:
MonitorMasterPort(const std::string& _name, MemCheckerMonitor& _mon)
: MasterPort(_name, &_mon), mon(_mon)
{ }
protected:
void recvFunctionalSnoop(PacketPtr pkt)
{
mon.recvFunctionalSnoop(pkt);
}
Tick recvAtomicSnoop(PacketPtr pkt)
{
return mon.recvAtomicSnoop(pkt);
}
bool recvTimingResp(PacketPtr pkt)
{
return mon.recvTimingResp(pkt);
}
void recvTimingSnoopReq(PacketPtr pkt)
{
mon.recvTimingSnoopReq(pkt);
}
void recvRangeChange()
{
mon.recvRangeChange();
}
bool isSnooping() const
{
return mon.isSnooping();
}
void recvReqRetry()
{
mon.recvReqRetry();
}
private:
MemCheckerMonitor& mon;
};
/** Instance of master port, facing the memory side */
MonitorMasterPort masterPort;
/**
* This is the slave port of the communication monitor. All recv
* functions call a function in MemCheckerMonitor, where the
* send function of the master port is called. Besides this, these
* functions can also perform actions for capturing statistics.
*/
class MonitorSlavePort : public SlavePort
{
public:
MonitorSlavePort(const std::string& _name, MemCheckerMonitor& _mon)
: SlavePort(_name, &_mon), mon(_mon)
{ }
protected:
void recvFunctional(PacketPtr pkt)
{
mon.recvFunctional(pkt);
}
Tick recvAtomic(PacketPtr pkt)
{
return mon.recvAtomic(pkt);
}
bool recvTimingReq(PacketPtr pkt)
{
return mon.recvTimingReq(pkt);
}
bool recvTimingSnoopResp(PacketPtr pkt)
{
return mon.recvTimingSnoopResp(pkt);
}
AddrRangeList getAddrRanges() const
{
return mon.getAddrRanges();
}
void recvRespRetry()
{
mon.recvRespRetry();
}
private:
MemCheckerMonitor& mon;
};
/** Instance of slave port, i.e. on the CPU side */
MonitorSlavePort slavePort;
void recvFunctional(PacketPtr pkt);
void recvFunctionalSnoop(PacketPtr pkt);
Tick recvAtomic(PacketPtr pkt);
Tick recvAtomicSnoop(PacketPtr pkt);
bool recvTimingReq(PacketPtr pkt);
bool recvTimingResp(PacketPtr pkt);
void recvTimingSnoopReq(PacketPtr pkt);
bool recvTimingSnoopResp(PacketPtr pkt);
AddrRangeList getAddrRanges() const;
bool isSnooping() const;
void recvReqRetry();
void recvRespRetry();
void recvRangeChange();
bool warnOnly;
MemChecker *memchecker;
};
#endif //__MEM_MEM_CHECKER_MONITOR_HH__