packet.hh revision 2392
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 40/** List of all commands associated with a packet. */ 41enum Command 42{ 43 Read, 44 Write 45}; 46 47/** The result of a particular pakets request. */ 48enum PacketResult 49{ 50 Success, 51 BadAddress 52}; 53 54class SenderState{}; 55class Coherence{}; 56 57typedef PacketDataPtr *unit8_t; 58 59/** 60 * A Packet is the structure to handle requests between two levels 61 * of the memory system. The Request is a global object that trancends 62 * all of the memory heirarchy, but at each levels interface a packet 63 * is created to transfer data/requests. For example, a request would 64 * be used to initiate a request to go to memory/IOdevices, as the request 65 * passes through the memory system several packets will be created. One 66 * will be created to go between the L1 and L2 caches and another to go to 67 * the next level and so forth. 68 * 69 * Packets are assumed to be returned in the case of a single response. If 70 * the transaction has no response, then the consumer will delete the packet. 71 */ 72struct Packet 73{ 74 /** The address of the request, could be virtual or physical (depending on 75 cache configurations). */ 76 Addr addr; 77 78 /** Flag structure to hold flags for this particular packet */ 79 uint64_t flags; 80 81 /** A pointer to the overall request. */ 82 RequestPtr req; 83 84 /** A virtual base opaque structure used to hold 85 coherence status messages. */ 86 Coherence *coherence; // virtual base opaque, 87 // assert(dynamic_cast<Foo>) etc. 88 89 /** A virtual base opaque structure used to hold the senders state. */ 90 SenderState *senderState; // virtual base opaque, 91 // assert(dynamic_cast<Foo>) etc. 92 93 /** A pointer to the data being transfered. It can be differnt sizes 94 at each level of the heirarchy so it belongs in the packet, 95 not request*/ 96 PacketDataPtr data; 97 98 /** Indicates the size of the request. */ 99 int size; 100 101 /** A index of the source of the transaction. */ 102 short src; 103 104 /** A index to the destination of the transaction. */ 105 short dest; 106 107 /** The command of the transaction. */ 108 Command cmd; 109 110 /** The result of the packet transaction. */ 111 PacketResult result; 112 113 /** Accessor function that returns the source index of the packet. */ 114 short getSrc() const { return src; } 115 116 /** Accessor function that returns the destination index of 117 the packet. */ 118 short getDest() const { return dest; } 119}; 120 121typedef PacketPtr *Packet; 122 123#endif //__MEM_PACKET_HH 124