dram_ctrl.hh

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/*
 * Copyright (c) 2012-2016 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) 2013 Amin Farmahini-Farahani
 * 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: Andreas Hansson
 *          Ani Udipi
 *          Neha Agarwal
 *          Omar Naji
 *          Matthias Jung
 *          Wendy Elsasser
 */

#ifndef __MEM_DRAM_CTRL_HH__
#define __MEM_DRAM_CTRL_HH__

#include <deque>
#include <string>
#include <unordered_set>

#include "base/callback.hh"
#include "base/statistics.hh"
#include "enums/AddrMap.hh"
#include "enums/MemSched.hh"
#include "enums/PageManage.hh"
#include "mem/abstract_mem.hh"
#include "mem/qport.hh"
#include "params/DRAMCtrl.hh"
#include "sim/eventq.hh"
#include "mem/drampower.hh"

class DRAMCtrl : public AbstractMemory
{

  private:

    // For now, make use of a queued slave port to avoid dealing with
    // flow control for the responses being sent back
    class MemoryPort : public QueuedSlavePort
    {

        RespPacketQueue queue;
        DRAMCtrl& memory;

      public:

        MemoryPort(const std::string& name, DRAMCtrl& _memory);

      protected:

        Tick recvAtomic(PacketPtr pkt);

        void recvFunctional(PacketPtr pkt);

        bool recvTimingReq(PacketPtr);

        virtual AddrRangeList getAddrRanges() const;

    };

    MemoryPort port;

    bool isTimingMode;

    bool retryRdReq;
    bool retryWrReq;

    enum BusState {
        READ = 0,
        WRITE,
    };

    BusState busState;

    /* bus state for next request event triggered */
    BusState busStateNext;

    struct Command {
       Data::MemCommand::cmds type;
       uint8_t bank;
       Tick timeStamp;

       constexpr Command(Data::MemCommand::cmds _type, uint8_t _bank,
                         Tick time_stamp)
            : type(_type), bank(_bank), timeStamp(time_stamp)
        { }
    };

    class Bank
    {

      public:

        static const uint32_t NO_ROW = -1;

        uint32_t openRow;
        uint8_t bank;
        uint8_t bankgr;

        Tick colAllowedAt;
        Tick preAllowedAt;
        Tick actAllowedAt;

        uint32_t rowAccesses;
        uint32_t bytesAccessed;

        Bank() :
            openRow(NO_ROW), bank(0), bankgr(0),
            colAllowedAt(0), preAllowedAt(0), actAllowedAt(0),
            rowAccesses(0), bytesAccessed(0)
        { }
    };


     enum PowerState {
         PWR_IDLE = 0,
         PWR_REF,
         PWR_SREF,
         PWR_PRE_PDN,
         PWR_ACT,
         PWR_ACT_PDN
     };

     enum RefreshState {
         REF_IDLE = 0,
         REF_DRAIN,
         REF_PD_EXIT,
         REF_SREF_EXIT,
         REF_PRE,
         REF_START,
         REF_RUN
     };

    class Rank : public EventManager
    {

      private:

        DRAMCtrl& memory;

        PowerState pwrStateTrans;

        PowerState pwrStatePostRefresh;

        Tick pwrStateTick;

        Tick refreshDueAt;

        /*
         * Command energies
         */
        Stats::Scalar actEnergy;
        Stats::Scalar preEnergy;
        Stats::Scalar readEnergy;
        Stats::Scalar writeEnergy;
        Stats::Scalar refreshEnergy;

        /*
         * Active Background Energy
         */
        Stats::Scalar actBackEnergy;

        /*
         * Precharge Background Energy
         */
        Stats::Scalar preBackEnergy;

        /*
         * Active Power-Down Energy
         */
        Stats::Scalar actPowerDownEnergy;

        /*
         * Precharge Power-Down Energy
         */
        Stats::Scalar prePowerDownEnergy;

        /*
         * self Refresh Energy
         */
        Stats::Scalar selfRefreshEnergy;

        Stats::Scalar totalEnergy;
        Stats::Scalar averagePower;

        Stats::Scalar totalIdleTime;

        Stats::Vector pwrStateTime;

        void updatePowerStats();

        void schedulePowerEvent(PowerState pwr_state, Tick tick);

      public:

        PowerState pwrState;

        RefreshState refreshState;

        bool inLowPowerState;

        uint8_t rank;

        uint32_t readEntries;

        uint32_t writeEntries;

        uint8_t outstandingEvents;

        Tick wakeUpAllowedAt;

        DRAMPower power;

        std::vector<Command> cmdList;

        std::vector<Bank> banks;

        unsigned int numBanksActive;

        std::deque<Tick> actTicks;

        Rank(DRAMCtrl& _memory, const DRAMCtrlParams* _p);

        const std::string name() const
        {
            return csprintf("%s_%d", memory.name(), rank);
        }

        void startup(Tick ref_tick);

        void suspend();

        bool isAvailable() const { return refreshState == REF_IDLE; }

        bool inPwrIdleState() const { return pwrState == PWR_IDLE; }

        bool forceSelfRefreshExit() const {
            return (readEntries != 0) ||
                   ((memory.busStateNext == WRITE) && (writeEntries != 0));
        }

        bool lowPowerEntryReady() const;

        void checkDrainDone();

        void flushCmdList();

        /*
         * Function to register Stats
         */
        void regStats();

        void computeStats();

        void powerDownSleep(PowerState pwr_state, Tick tick);

        void scheduleWakeUpEvent(Tick exit_delay);

        void processWriteDoneEvent();
        EventWrapper<Rank, &Rank::processWriteDoneEvent>
        writeDoneEvent;

        void processActivateEvent();
        EventWrapper<Rank, &Rank::processActivateEvent>
        activateEvent;

        void processPrechargeEvent();
        EventWrapper<Rank, &Rank::processPrechargeEvent>
        prechargeEvent;

        void processRefreshEvent();
        EventWrapper<Rank, &Rank::processRefreshEvent>
        refreshEvent;

        void processPowerEvent();
        EventWrapper<Rank, &Rank::processPowerEvent>
        powerEvent;

        void processWakeUpEvent();
        EventWrapper<Rank, &Rank::processWakeUpEvent>
        wakeUpEvent;

    };

    // define the process to compute stats on simulation exit
    // defined per rank as the per rank stats are based on state
    // transition and periodically updated, requiring re-sync at
    // exit.
    class RankDumpCallback : public Callback
    {
        Rank *ranks;
      public:
        RankDumpCallback(Rank *r) : ranks(r) {}
        virtual void process() { ranks->computeStats(); };
    };

    class BurstHelper {

      public:

        const unsigned int burstCount;

        unsigned int burstsServiced;

        BurstHelper(unsigned int _burstCount)
            : burstCount(_burstCount), burstsServiced(0)
        { }
    };

    class DRAMPacket {

      public:

        const Tick entryTime;

        Tick readyTime;

        const PacketPtr pkt;

        const bool isRead;

        const uint8_t rank;
        const uint8_t bank;
        const uint32_t row;

        const uint16_t bankId;

        Addr addr;

        unsigned int size;

        BurstHelper* burstHelper;
        Bank& bankRef;
        Rank& rankRef;

        DRAMPacket(PacketPtr _pkt, bool is_read, uint8_t _rank, uint8_t _bank,
                   uint32_t _row, uint16_t bank_id, Addr _addr,
                   unsigned int _size, Bank& bank_ref, Rank& rank_ref)
            : entryTime(curTick()), readyTime(curTick()),
              pkt(_pkt), isRead(is_read), rank(_rank), bank(_bank), row(_row),
              bankId(bank_id), addr(_addr), size(_size), burstHelper(NULL),
              bankRef(bank_ref), rankRef(rank_ref)
        { }

    };

    void processNextReqEvent();
    EventWrapper<DRAMCtrl,&DRAMCtrl::processNextReqEvent> nextReqEvent;

    void processRespondEvent();
    EventWrapper<DRAMCtrl, &DRAMCtrl::processRespondEvent> respondEvent;

    bool readQueueFull(unsigned int pktCount) const;

    bool writeQueueFull(unsigned int pktCount) const;

    void addToReadQueue(PacketPtr pkt, unsigned int pktCount);

    void addToWriteQueue(PacketPtr pkt, unsigned int pktCount);

    void doDRAMAccess(DRAMPacket* dram_pkt);

    void accessAndRespond(PacketPtr pkt, Tick static_latency);

    DRAMPacket* decodeAddr(PacketPtr pkt, Addr dramPktAddr, unsigned int size,
                           bool isRead);

    bool chooseNext(std::deque<DRAMPacket*>& queue, Tick extra_col_delay);

    bool reorderQueue(std::deque<DRAMPacket*>& queue, Tick extra_col_delay);

    std::pair<uint64_t, bool> minBankPrep(const std::deque<DRAMPacket*>& queue,
                                          Tick min_col_at) const;

    void activateBank(Rank& rank_ref, Bank& bank_ref, Tick act_tick,
                      uint32_t row);

    void prechargeBank(Rank& rank_ref, Bank& bank_ref,
                       Tick pre_at, bool trace = true);

    void printQs() const;

    Addr burstAlign(Addr addr) const { return (addr & ~(Addr(burstSize - 1))); }

    std::deque<DRAMPacket*> readQueue;
    std::deque<DRAMPacket*> writeQueue;

    std::unordered_set<Addr> isInWriteQueue;

    std::deque<DRAMPacket*> respQueue;

    std::vector<Rank*> ranks;

    const uint32_t deviceSize;
    const uint32_t deviceBusWidth;
    const uint32_t burstLength;
    const uint32_t deviceRowBufferSize;
    const uint32_t devicesPerRank;
    const uint32_t burstSize;
    const uint32_t rowBufferSize;
    const uint32_t columnsPerRowBuffer;
    const uint32_t columnsPerStripe;
    const uint32_t ranksPerChannel;
    const uint32_t bankGroupsPerRank;
    const bool bankGroupArch;
    const uint32_t banksPerRank;
    const uint32_t channels;
    uint32_t rowsPerBank;
    const uint32_t readBufferSize;
    const uint32_t writeBufferSize;
    const uint32_t writeHighThreshold;
    const uint32_t writeLowThreshold;
    const uint32_t minWritesPerSwitch;
    uint32_t writesThisTime;
    uint32_t readsThisTime;

    const Tick M5_CLASS_VAR_USED tCK;
    const Tick tWTR;
    const Tick tRTW;
    const Tick tCS;
    const Tick tBURST;
    const Tick tCCD_L;
    const Tick tRCD;
    const Tick tCL;
    const Tick tRP;
    const Tick tRAS;
    const Tick tWR;
    const Tick tRTP;
    const Tick tRFC;
    const Tick tREFI;
    const Tick tRRD;
    const Tick tRRD_L;
    const Tick tXAW;
    const Tick tXP;
    const Tick tXS;
    const uint32_t activationLimit;

    Enums::MemSched memSchedPolicy;
    Enums::AddrMap addrMapping;
    Enums::PageManage pageMgmt;

    const uint32_t maxAccessesPerRow;

    const Tick frontendLatency;

    const Tick backendLatency;

    Tick busBusyUntil;

    Tick prevArrival;

    Tick nextReqTime;

    // All statistics that the model needs to capture
    Stats::Scalar readReqs;
    Stats::Scalar writeReqs;
    Stats::Scalar readBursts;
    Stats::Scalar writeBursts;
    Stats::Scalar bytesReadDRAM;
    Stats::Scalar bytesReadWrQ;
    Stats::Scalar bytesWritten;
    Stats::Scalar bytesReadSys;
    Stats::Scalar bytesWrittenSys;
    Stats::Scalar servicedByWrQ;
    Stats::Scalar mergedWrBursts;
    Stats::Scalar neitherReadNorWrite;
    Stats::Vector perBankRdBursts;
    Stats::Vector perBankWrBursts;
    Stats::Scalar numRdRetry;
    Stats::Scalar numWrRetry;
    Stats::Scalar totGap;
    Stats::Vector readPktSize;
    Stats::Vector writePktSize;
    Stats::Vector rdQLenPdf;
    Stats::Vector wrQLenPdf;
    Stats::Histogram bytesPerActivate;
    Stats::Histogram rdPerTurnAround;
    Stats::Histogram wrPerTurnAround;

    // Latencies summed over all requests
    Stats::Scalar totQLat;
    Stats::Scalar totMemAccLat;
    Stats::Scalar totBusLat;

    // Average latencies per request
    Stats::Formula avgQLat;
    Stats::Formula avgBusLat;
    Stats::Formula avgMemAccLat;

    // Average bandwidth
    Stats::Formula avgRdBW;
    Stats::Formula avgWrBW;
    Stats::Formula avgRdBWSys;
    Stats::Formula avgWrBWSys;
    Stats::Formula peakBW;
    Stats::Formula busUtil;
    Stats::Formula busUtilRead;
    Stats::Formula busUtilWrite;

    // Average queue lengths
    Stats::Average avgRdQLen;
    Stats::Average avgWrQLen;

    // Row hit count and rate
    Stats::Scalar readRowHits;
    Stats::Scalar writeRowHits;
    Stats::Formula readRowHitRate;
    Stats::Formula writeRowHitRate;
    Stats::Formula avgGap;

    // DRAM Power Calculation
    Stats::Formula pageHitRate;

    // Holds the value of the rank of burst issued
    uint8_t activeRank;

    // timestamp offset
    uint64_t timeStampOffset;

    std::unique_ptr<Packet> pendingDelete;

    void updatePowerStats(Rank& rank_ref);

    static bool sortTime(const Command& cmd, const Command& cmd_next) {
        return cmd.timeStamp < cmd_next.timeStamp;
    };

  public:

    void regStats() override;

    DRAMCtrl(const DRAMCtrlParams* p);

    DrainState drain() override;

    virtual BaseSlavePort& getSlavePort(const std::string& if_name,
                                        PortID idx = InvalidPortID) override;

    virtual void init() override;
    virtual void startup() override;
    virtual void drainResume() override;

    bool allRanksDrained() const;

  protected:

    Tick recvAtomic(PacketPtr pkt);
    void recvFunctional(PacketPtr pkt);
    bool recvTimingReq(PacketPtr pkt);

};

#endif //__MEM_DRAM_CTRL_HH__