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+/*
+ * 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.
+ */
+
+/**
+ * @file
+ * Declaration of the Packet Class, a packet is a transaction occuring
+ * between a single level of the memory heirarchy (ie L1->L2).
+ */
+
+#ifndef __MEM_PACKET_HH__
+#define __MEM_PACKET_HH__
+
+#include "mem/request.hh"
+#include "arch/isa_traits.hh"
+#include "sim/root.hh"
+
+struct Packet;
+typedef Packet* PacketPtr;
+typedef uint8_t* PacketDataPtr;
+
+/**
+ * A Packet is the structure to handle requests between two levels
+ * of the memory system. The Request is a global object that trancends
+ * all of the memory heirarchy, but at each levels interface a packet
+ * is created to transfer data/requests. For example, a request would
+ * be used to initiate a request to go to memory/IOdevices, as the request
+ * passes through the memory system several packets will be created. One
+ * will be created to go between the L1 and L2 caches and another to go to
+ * the next level and so forth.
+ *
+ * Packets are assumed to be returned in the case of a single response. If
+ * the transaction has no response, then the consumer will delete the packet.
+ */
+class Packet
+{
+ private:
+ /** A pointer to the data being transfered. It can be differnt sizes
+ at each level of the heirarchy so it belongs in the packet,
+ not request. This may or may not be populated when a responder recieves
+ the packet. If not populated it memory should be allocated.
+ */
+ PacketDataPtr data;
+
+ /** Is the data pointer set to a value that shouldn't be freed when the
+ * packet is destroyed? */
+ bool staticData;
+ /** The data pointer points to a value that should be freed when the packet
+ * is destroyed. */
+ bool dynamicData;
+ /** the data pointer points to an array (thus delete [] ) needs to be called
+ * on it rather than simply delete.*/
+ bool arrayData;
+
+
+ /** The address of the request, could be virtual or physical (depending on
+ cache configurations). */
+ Addr addr;
+
+ /** Indicates the size of the request. */
+ int size;
+
+ /** A index of the source of the transaction. */
+ short src;
+
+ /** A index to the destination of the transaction. */
+ short dest;
+
+ bool addrValid;
+ bool sizeValid;
+ bool srcValid;
+
+ public:
+
+ static const short Broadcast = -1;
+
+ /** A pointer to the overall request. */
+ RequestPtr req;
+
+ class CoherenceState {
+ public:
+ virtual ~CoherenceState() {}
+ };
+
+ /** A virtual base opaque structure used to hold
+ coherence status messages. */
+ CoherenceState *coherence; // virtual base opaque,
+ // assert(dynamic_cast<Foo>) etc.
+
+ class SenderState {
+ public:
+ virtual ~SenderState() {}
+ };
+
+ /** A virtual base opaque structure used to hold the senders state. */
+ SenderState *senderState; // virtual base opaque,
+ // assert(dynamic_cast<Foo>) etc.
+
+ private:
+ /** List of command attributes. */
+ enum CommandAttribute
+ {
+ IsRead = 1 << 0,
+ IsWrite = 1 << 1,
+ IsPrefetch = 1 << 2,
+ IsInvalidate = 1 << 3,
+ IsRequest = 1 << 4,
+ IsResponse = 1 << 5,
+ NeedsResponse = 1 << 6,
+ };
+
+ public:
+ /** List of all commands associated with a packet. */
+ enum Command
+ {
+ ReadReq = IsRead | IsRequest | NeedsResponse,
+ WriteReq = IsWrite | IsRequest | NeedsResponse,
+ WriteReqNoAck = IsWrite | IsRequest,
+ ReadResp = IsRead | IsResponse,
+ WriteResp = IsWrite | IsResponse
+ };
+
+ const std::string &cmdString() const;
+
+ /** The command of the transaction. */
+ Command cmd;
+
+ bool isRead() { return (cmd & IsRead) != 0; }
+ bool isRequest() { return (cmd & IsRequest) != 0; }
+ bool isResponse() { return (cmd & IsResponse) != 0; }
+ bool needsResponse() { return (cmd & NeedsResponse) != 0; }
+
+ void makeTimingResponse() {
+ assert(needsResponse());
+ int icmd = (int)cmd;
+ icmd &= ~(IsRequest | NeedsResponse);
+ icmd |= IsResponse;
+ cmd = (Command)icmd;
+ dest = src;
+ srcValid = false;
+ }
+
+ /** The time this request was responded to. Used to calculate latencies. */
+ Tick time;
+
+ /** The result of a particular packets request. */
+ enum Result
+ {
+ Success,
+ BadAddress,
+ Unknown
+ };
+
+ /** The result of the packet transaction. */
+ Result result;
+
+ /** 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; }
+
+ /** Accessor function that returns the destination index of
+ the packet. */
+ short getDest() const { return dest; }
+ void setDest(short _dest) { dest = _dest; }
+
+ Addr getAddr() const { assert(addrValid); return addr; }
+ void setAddr(Addr _addr) { addr = _addr; addrValid = true; }
+
+ int getSize() const { assert(sizeValid); return size; }
+ void setSize(int _size) { size = _size; sizeValid = true; }
+
+
+ Packet(Request *_req, Command _cmd, short _dest)
+ : data(NULL), staticData(false), dynamicData(false), arrayData(false),
+ addr(_req->paddr), size(_req->size), dest(_dest),
+ addrValid(_req->validPaddr), sizeValid(_req->validSize),
+ srcValid(false),
+ req(_req), coherence(NULL), senderState(NULL), cmd(_cmd),
+ time(curTick), result(Unknown)
+ {
+ }
+
+ ~Packet()
+ { deleteData(); }
+
+
+ /** Minimally reset a packet so something like simple cpu can reuse it. */
+ void reset();
+
+ void reinitFromRequest() {
+ if (req->validPaddr) setAddr(req->paddr);
+ if (req->validSize) setSize(req->size);
+ }
+
+ /** Set the data pointer to the following value that should not be freed. */
+ template <typename T>
+ void dataStatic(T *p);
+
+ /** Set the data pointer to a value that should have delete [] called on it.
+ */
+ template <typename T>
+ void dataDynamicArray(T *p);
+
+ /** set the data pointer to a value that should have delete called on it. */
+ template <typename T>
+ void dataDynamic(T *p);
+
+ /** return the value of what is pointed to in the packet. */
+ template <typename T>
+ T get();
+
+ /** get a pointer to the data ptr. */
+ template <typename T>
+ T* getPtr();
+
+ /** set the value in the data pointer to v. */
+ template <typename T>
+ void set(T v);
+
+ /** 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();
+
+ /** Do the packet modify the same addresses. */
+ bool intersect(Packet *p);
+};
+
+bool fixPacket(Packet *func, Packet *timing);
+#endif //__MEM_PACKET_HH
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