packet.hh revision 2497
1/* 2 * Copyright (c) 2003 The Regents of The University of Michigan 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer; 9 * redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution; 12 * neither the name of the copyright holders nor the names of its 13 * contributors may be used to endorse or promote products derived from 14 * this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29/** 30 * @file 31 * Declaration of the Packet Class, a packet is a transaction occuring 32 * between a single level of the memory heirarchy (ie L1->L2). 33 */ 34 35#ifndef __MEM_PACKET_HH__ 36#define __MEM_PACKET_HH__ 37 38#include "mem/request.hh" 39#include "arch/isa_traits.hh" 40#include "sim/root.hh" 41 42struct Packet; 43typedef Packet* PacketPtr; 44typedef uint8_t* PacketDataPtr; 45 46/** List of all commands associated with a packet. */ 47enum Command 48{ 49 Read, 50 Write 51}; 52 53/** The result of a particular pakets request. */ 54enum PacketResult 55{ 56 Success, 57 BadAddress, 58 Unknown 59}; 60 61class SenderState{}; 62class Coherence{}; 63 64/** 65 * A Packet is the structure to handle requests between two levels 66 * of the memory system. The Request is a global object that trancends 67 * all of the memory heirarchy, but at each levels interface a packet 68 * is created to transfer data/requests. For example, a request would 69 * be used to initiate a request to go to memory/IOdevices, as the request 70 * passes through the memory system several packets will be created. One 71 * will be created to go between the L1 and L2 caches and another to go to 72 * the next level and so forth. 73 * 74 * Packets are assumed to be returned in the case of a single response. If 75 * the transaction has no response, then the consumer will delete the packet. 76 */ 77struct Packet 78{ 79 /** The address of the request, could be virtual or physical (depending on 80 cache configurations). */ 81 Addr addr; 82 83 /** Flag structure to hold flags for this particular packet */ 84 uint64_t flags; 85 86 /** A pointer to the overall request. */ 87 RequestPtr req; 88 89 /** A virtual base opaque structure used to hold 90 coherence status messages. */ 91 Coherence *coherence; // virtual base opaque, 92 // assert(dynamic_cast<Foo>) etc. 93 94 /** A virtual base opaque structure used to hold the senders state. */ 95 SenderState *senderState; // virtual base opaque, 96 // assert(dynamic_cast<Foo>) etc. 97 98 /** A pointer to the data being transfered. It can be differnt sizes 99 at each level of the heirarchy so it belongs in the packet, 100 not request*/ 101 PacketDataPtr data; 102 103 /** Indicates the size of the request. */ 104 int size; 105 106 /** A index of the source of the transaction. */ 107 short src; 108 109 /** A index to the destination of the transaction. */ 110 short dest; 111 112 /** The command of the transaction. */ 113 Command cmd; 114 115 /** The time this request was responded to. Used to calculate latencies. */ 116 Tick time; 117 118 /** The result of the packet transaction. */ 119 PacketResult result; 120 121 /** Accessor function that returns the source index of the packet. */ 122 short getSrc() const { return src; } 123 124 /** Accessor function that returns the destination index of 125 the packet. */ 126 short getDest() const { return dest; } 127}; 128 129#endif //__MEM_PACKET_HH 130