packet.hh

来自「M5,一个功能强大的多处理器系统模拟器.很多针对处理器架构,性能的研究都使用它作」· HH 代码 · 共 666 行 · 第 1/2 页

         * prefix string onto the current prefix.  Labels will only be
         * printed if an object within the label's scope is
         * printed. */
        void pushLabel(const std::string &lbl,
                       const std::string &prefix = "  ");
        /** Pop a label off the label stack. */
        void popLabel();
        /** Print all of the pending unprinted labels on the
         * stack. Called by printObj(), so normally not called by
         * users unless bypassing printObj(). */
        void printLabels();
        /** Print a Printable object to os, because it matched the
         * address on a PrintReq. */
        void printObj(Printable *obj);
    };

    /** This packet's sender state.  Devices should use dynamic_cast<>
     *   to cast to the state appropriate to the sender. */
    SenderState *senderState;

    /** Return the string name of the cmd field (for debugging and
     *   tracing). */
    const std::string &cmdString() const { return cmd.toString(); }

    /** Return the index of this command. */
    inline int cmdToIndex() const { return cmd.toInt(); }

    bool isRead() const         { return cmd.isRead(); }
    bool isWrite()  const       { return cmd.isWrite(); }
    bool isRequest() const      { return cmd.isRequest(); }
    bool isResponse() const     { return cmd.isResponse(); }
    bool needsExclusive() const { return cmd.needsExclusive(); }
    bool needsResponse() const  { return cmd.needsResponse(); }
    bool isInvalidate() const   { return cmd.isInvalidate(); }
    bool hasData() const        { return cmd.hasData(); }
    bool isReadWrite() const    { return cmd.isReadWrite(); }
    bool isLocked() const       { return cmd.isLocked(); }
    bool isError() const        { return cmd.isError(); }
    bool isPrint() const        { return cmd.isPrint(); }

    // Snoop flags
    void assertMemInhibit()     { flags[MemInhibit] = true; }
    bool memInhibitAsserted()   { return flags[MemInhibit]; }
    void assertShared()         { flags[Shared] = true; }
    bool sharedAsserted()       { return flags[Shared]; }

    // Special control flags
    void setExpressSnoop()      { flags[ExpressSnoop] = true; }
    bool isExpressSnoop()       { return flags[ExpressSnoop]; }
    void setSupplyExclusive()   { flags[SupplyExclusive] = true; }
    bool isSupplyExclusive()    { return flags[SupplyExclusive]; }

    // Network error conditions... encapsulate them as methods since
    // their encoding keeps changing (from result field to command
    // field, etc.)
    void setNacked()     { assert(isResponse()); cmd = MemCmd::NetworkNackError; }
    void setBadAddress() { assert(isResponse()); cmd = MemCmd::BadAddressError; }
    bool wasNacked()     { return cmd == MemCmd::NetworkNackError; }
    bool hadBadAddress() { return cmd == MemCmd::BadAddressError; }
    void copyError(Packet *pkt) { assert(pkt->isError()); cmd = pkt->cmd; }

    bool nic_pkt() { panic("Unimplemented"); M5_DUMMY_RETURN }

    /** Accessor function that returns the source index of the packet. */
    short getSrc() const    { assert(srcValid); return src; }
    void setSrc(short _src) { src = _src; srcValid = true; }
    /** Reset source field, e.g. to retransmit packet on different bus. */
    void clearSrc() { srcValid = false; }

    /** Accessor function that returns the destination index of
        the packet. */
    short getDest() const     { assert(destValid); return dest; }
    void setDest(short _dest) { dest = _dest; destValid = true; }

    Addr getAddr() const { assert(addrSizeValid); return addr; }
    int getSize() const  { assert(addrSizeValid); return size; }
    Addr getOffset(int blkSize) const { return addr & (Addr)(blkSize - 1); }

    /** Constructor.  Note that a Request object must be constructed
     *   first, but the Requests's physical address and size fields
     *   need not be valid. The command and destination addresses
     *   must be supplied.  */
    Packet(Request *_req, MemCmd _cmd, short _dest)
        :  cmd(_cmd), req(_req),
           data(NULL), staticData(false), dynamicData(false), arrayData(false),
           addr(_req->paddr), size(_req->size), dest(_dest),
           addrSizeValid(_req->validPaddr), srcValid(false), destValid(true),
           flags(0), time(curTick), senderState(NULL)
    {
    }

    /** Alternate constructor if you are trying to create a packet with
     *  a request that is for a whole block, not the address from the req.
     *  this allows for overriding the size/addr of the req.*/
    Packet(Request *_req, MemCmd _cmd, short _dest, int _blkSize)
        :  cmd(_cmd), req(_req),
           data(NULL), staticData(false), dynamicData(false), arrayData(false),
           addr(_req->paddr & ~(_blkSize - 1)), size(_blkSize), dest(_dest),
           addrSizeValid(_req->validPaddr), srcValid(false), destValid(true),
           flags(0), time(curTick), senderState(NULL)
    {
    }

    /** Alternate constructor for copying a packet.  Copy all fields
     * *except* if the original packet's data was dynamic, don't copy
     * that, as we can't guarantee that the new packet's lifetime is
     * less than that of the original packet.  In this case the new
     * packet should allocate its own data. */
    Packet(Packet *origPkt, bool clearFlags = false)
        :  cmd(origPkt->cmd), req(origPkt->req),
           data(origPkt->staticData ? origPkt->data : NULL),
           staticData(origPkt->staticData),
           dynamicData(false), arrayData(false),
           addr(origPkt->addr), size(origPkt->size),
           src(origPkt->src), dest(origPkt->dest),
           addrSizeValid(origPkt->addrSizeValid),
           srcValid(origPkt->srcValid), destValid(origPkt->destValid),
           flags(clearFlags ? 0 : origPkt->flags),
           time(curTick), senderState(origPkt->senderState)
    {
    }

    /** Destructor. */
    ~Packet()
    { if (staticData || dynamicData) deleteData(); }

    /** Reinitialize packet address and size from the associated
     *   Request object, and reset other fields that may have been
     *   modified by a previous transaction.  Typically called when a
     *   statically allocated Request/Packet pair is reused for
     *   multiple transactions. */
    void reinitFromRequest() {
        assert(req->validPaddr);
        flags = 0;
        addr = req->paddr;
        size = req->size;
        time = req->time;
        addrSizeValid = true;
        if (dynamicData) {
            deleteData();
            dynamicData = false;
            arrayData = false;
        }
    }

    /**
     * Take a request packet and modify it in place to be suitable for
     * returning as a response to that request.  The source and
     * destination fields are *not* modified, as is appropriate for
     * atomic accesses.
     */
    void makeResponse()
    {
        assert(needsResponse());
        assert(isRequest());
        origCmd = cmd;
        cmd = cmd.responseCommand();
        dest = src;
        destValid = srcValid;
        srcValid = false;
    }

    void makeAtomicResponse()
    {
        makeResponse();
    }

    void makeTimingResponse()
    {
        makeResponse();
    }

    /**
     * Take a request packet that has been returned as NACKED and
     * modify it so that it can be sent out again. Only packets that
     * need a response can be NACKED, so verify that that is true.
     */
    void
    reinitNacked()
    {
        assert(wasNacked());
        cmd = origCmd;
        assert(needsResponse());
        setDest(Broadcast);
    }


    /**
     * Set the data pointer to the following value that should not be
     * freed.
     */
    template <typename T>
    void
    dataStatic(T *p)
    {
        if(dynamicData)
            dynamicData = false;
        data = (PacketDataPtr)p;
        staticData = true;
    }

    /**
     * Set the data pointer to a value that should have delete []
     * called on it.
     */
    template <typename T>
    void
    dataDynamicArray(T *p)
    {
        assert(!staticData && !dynamicData);
        data = (PacketDataPtr)p;
        dynamicData = true;
        arrayData = true;
    }

    /**
     * set the data pointer to a value that should have delete called
     * on it.
     */
    template <typename T>
    void
    dataDynamic(T *p)
    {
        assert(!staticData && !dynamicData);
        data = (PacketDataPtr)p;
        dynamicData = true;
        arrayData = false;
    }

    /** get a pointer to the data ptr. */
    template <typename T>
    T*
    getPtr()
    {
        assert(staticData || dynamicData);
        return (T*)data;
    }

    /** return the value of what is pointed to in the packet. */
    template <typename T>
    T get();

    /** set the value in the data pointer to v. */
    template <typename T>
    void set(T v);

    /**
     * Copy data into the packet from the provided pointer.
     */
    void setData(uint8_t *p)
    {
        std::memcpy(getPtr<uint8_t>(), p, getSize());
    }

    /**
     * Copy data into the packet from the provided block pointer,
     * which is aligned to the given block size.
     */
    void setDataFromBlock(uint8_t *blk_data, int blkSize)
    {
        setData(blk_data + getOffset(blkSize));
    }

    /**
     * Copy data from the packet to the provided block pointer, which
     * is aligned to the given block size.
     */
    void writeData(uint8_t *p)
    {
        std::memcpy(p, getPtr<uint8_t>(), getSize());
    }

    /**
     * Copy data from the packet to the memory at the provided pointer.
     */
    void writeDataToBlock(uint8_t *blk_data, int blkSize)
    {
        writeData(blk_data + getOffset(blkSize));
    }

    /**
     * delete the data pointed to in the data pointer. Ok to call to
     * matter how data was allocted.
     */
    void deleteData();

    /** If there isn't data in the packet, allocate some. */
    void allocate();

    /**
     * Check a functional request against a memory value represented
     * by a base/size pair and an associated data array.  If the
     * functional request is a read, it may be satisfied by the memory
     * value.  If the functional request is a write, it may update the
     * memory value.
     */
    bool checkFunctional(Printable *obj, Addr base, int size, uint8_t *data);

    /**
     * Check a functional request against a memory value stored in
     * another packet (i.e. an in-transit request or response).
     */
    bool checkFunctional(PacketPtr otherPkt) {
        return checkFunctional(otherPkt,
                               otherPkt->getAddr(), otherPkt->getSize(),
                               otherPkt->hasData() ?
                                   otherPkt->getPtr<uint8_t>() : NULL);
    }

    /**
     * Push label for PrintReq (safe to call unconditionally).
     */
    void pushLabel(const std::string &lbl) {
        if (isPrint()) {
            dynamic_cast<PrintReqState*>(senderState)->pushLabel(lbl);
        }
    }

    /**
     * Pop label for PrintReq (safe to call unconditionally).
     */
    void popLabel() {
        if (isPrint()) {
            dynamic_cast<PrintReqState*>(senderState)->popLabel();
        }
    }

    void print(std::ostream &o, int verbosity = 0,
               const std::string &prefix = "") const;
};

#endif //__MEM_PACKET_HH