gem5/src/cpu/ozone/front_end.hh
2011-04-15 10:44:06 -07:00

325 lines
8.7 KiB
C++

/*
* Copyright (c) 2006 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: Kevin Lim
*/
#ifndef __CPU_OZONE_FRONT_END_HH__
#define __CPU_OZONE_FRONT_END_HH__
#include <deque>
#include "arch/utility.hh"
#include "config/the_isa.hh"
#include "cpu/o3/bpred_unit.hh"
#include "cpu/ozone/rename_table.hh"
#include "cpu/inst_seq.hh"
#include "cpu/timebuf.hh"
#include "mem/port.hh"
#include "mem/request.hh"
#include "sim/eventq.hh"
#include "sim/stats.hh"
class ThreadContext;
class MemObject;
template <class>
class OzoneThreadState;
class PageTable;
template <class>
class TimeBuffer;
template <class Impl>
class FrontEnd
{
public:
typedef typename Impl::Params Params;
typedef typename Impl::DynInst DynInst;
typedef typename Impl::DynInstPtr DynInstPtr;
typedef typename Impl::CPUType CPUType;
typedef typename Impl::BackEnd BackEnd;
typedef typename Impl::CPUType::OzoneTC OzoneTC;
typedef typename Impl::CPUType::CommStruct CommStruct;
/** IcachePort class. Handles doing the communication with the
* cache/memory.
*/
class IcachePort : public Port
{
protected:
/** Pointer to FE. */
FrontEnd<Impl> *fe;
public:
/** Default constructor. */
IcachePort(FrontEnd<Impl> *_fe)
: fe(_fe)
{ }
protected:
/** Atomic version of receive. Panics. */
virtual Tick recvAtomic(PacketPtr pkt);
/** Functional version of receive. Panics. */
virtual void recvFunctional(PacketPtr pkt);
/** Receives status change. Other than range changing, panics. */
virtual void recvStatusChange(Status status);
/** Returns the address ranges of this device. */
virtual void getDeviceAddressRanges(AddrRangeList &resp,
bool &snoop)
{ resp.clear(); snoop = true; }
/** Timing version of receive. Handles setting fetch to the
* proper status to start fetching. */
virtual bool recvTiming(PacketPtr pkt);
/** Handles doing a retry of a failed fetch. */
virtual void recvRetry();
};
FrontEnd(Params *params);
std::string name() const;
void setCPU(CPUType *cpu_ptr);
void setBackEnd(BackEnd *back_end_ptr)
{ backEnd = back_end_ptr; }
void setCommBuffer(TimeBuffer<CommStruct> *_comm);
void setTC(ThreadContext *tc_ptr);
void setThreadState(OzoneThreadState<Impl> *thread_ptr)
{ thread = thread_ptr; }
void regStats();
Port *getIcachePort() { return &icachePort; }
void tick();
Fault fetchCacheLine();
void processInst(DynInstPtr &inst);
void squash(const InstSeqNum &squash_num, const Addr &next_PC,
const bool is_branch = false, const bool branch_taken = false);
DynInstPtr getInst();
void processCacheCompletion(PacketPtr pkt);
void addFreeRegs(int num_freed);
bool isEmpty() { return instBuffer.empty(); }
void switchOut();
void doSwitchOut();
void takeOverFrom(ThreadContext *old_tc = NULL);
bool isSwitchedOut() { return switchedOut; }
bool switchedOut;
private:
void recvRetry();
bool updateStatus();
void checkBE();
DynInstPtr getInstFromCacheline();
void renameInst(DynInstPtr &inst);
// Returns true if we need to stop the front end this cycle
bool processBarriers(DynInstPtr &inst);
void handleFault(Fault &fault);
public:
Fault getFault() { return fetchFault; }
private:
Fault fetchFault;
// Align an address (typically a PC) to the start of an I-cache block.
// We fold in the PISA 64- to 32-bit conversion here as well.
Addr icacheBlockAlignPC(Addr addr)
{
return (addr & ~(cacheBlkMask));
}
InstSeqNum getAndIncrementInstSeq()
{ return cpu->globalSeqNum++; }
public:
CPUType *cpu;
BackEnd *backEnd;
ThreadContext *tc;
OzoneThreadState<Impl> *thread;
enum Status {
Running,
Idle,
IcacheWaitResponse,
IcacheWaitRetry,
IcacheAccessComplete,
SerializeBlocked,
SerializeComplete,
RenameBlocked,
QuiescePending,
TrapPending,
BEBlocked
};
Status status;
private:
TimeBuffer<CommStruct> *comm;
typename TimeBuffer<CommStruct>::wire fromCommit;
typedef typename Impl::BranchPred BranchPred;
BranchPred branchPred;
IcachePort icachePort;
RequestPtr memReq;
/** Mask to get a cache block's address. */
Addr cacheBlkMask;
unsigned cacheBlkSize;
Addr cacheBlkPC;
/** The cache line being fetched. */
uint8_t *cacheData;
bool fetchCacheLineNextCycle;
bool cacheBlkValid;
bool cacheBlocked;
/** The packet that is waiting to be retried. */
PacketPtr retryPkt;
public:
RenameTable<Impl> renameTable;
private:
Addr PC;
Addr nextPC;
public:
void setPC(Addr val) { PC = val; }
void setNextPC(Addr val) { nextPC = val; }
void wakeFromQuiesce();
void dumpInsts();
private:
TimeBuffer<int> numInstsReady;
typedef typename std::deque<DynInstPtr> InstBuff;
typedef typename InstBuff::iterator InstBuffIt;
InstBuff feBuffer;
InstBuff instBuffer;
int instBufferSize;
int maxInstBufferSize;
int latency;
int width;
int freeRegs;
int numPhysRegs;
bool serializeNext;
DynInstPtr barrierInst;
public:
bool interruptPending;
private:
// number of idle cycles
/*
Stats::Average notIdleFraction;
Stats::Formula idleFraction;
*/
// @todo: Consider making these vectors and tracking on a per thread basis.
/** Stat for total number of cycles stalled due to an icache miss. */
Stats::Scalar icacheStallCycles;
/** Stat for total number of fetched instructions. */
Stats::Scalar fetchedInsts;
Stats::Scalar fetchedBranches;
/** Stat for total number of predicted branches. */
Stats::Scalar predictedBranches;
/** Stat for total number of cycles spent fetching. */
Stats::Scalar fetchCycles;
Stats::Scalar fetchIdleCycles;
/** Stat for total number of cycles spent squashing. */
Stats::Scalar fetchSquashCycles;
/** Stat for total number of cycles spent blocked due to other stages in
* the pipeline.
*/
Stats::Scalar fetchBlockedCycles;
/** Stat for total number of fetched cache lines. */
Stats::Scalar fetchedCacheLines;
Stats::Scalar fetchIcacheSquashes;
/** Distribution of number of instructions fetched each cycle. */
Stats::Distribution fetchNisnDist;
// Stats::Vector qfull_iq_occupancy;
// Stats::VectorDistribution qfull_iq_occ_dist_;
Stats::Formula idleRate;
Stats::Formula branchRate;
Stats::Formula fetchRate;
Stats::Scalar IFQCount; // cumulative IFQ occupancy
Stats::Formula IFQOccupancy;
Stats::Formula IFQLatency;
Stats::Scalar IFQFcount; // cumulative IFQ full count
Stats::Formula IFQFullRate;
Stats::Scalar dispatchCountStat;
Stats::Scalar dispatchedSerializing;
Stats::Scalar dispatchedTempSerializing;
Stats::Scalar dispatchSerializeStallCycles;
Stats::Formula dispatchRate;
Stats::Formula regIntFull;
Stats::Formula regFpFull;
};
#endif // __CPU_OZONE_FRONT_END_HH__