packet.hh revision 2394
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 "targetarch/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}; 59 60class SenderState{}; 61class Coherence{}; 62 63/** 64 * A Packet is the structure to handle requests between two levels 65 * of the memory system. The Request is a global object that trancends 66 * all of the memory heirarchy, but at each levels interface a packet 67 * is created to transfer data/requests. For example, a request would 68 * be used to initiate a request to go to memory/IOdevices, as the request 69 * passes through the memory system several packets will be created. One 70 * will be created to go between the L1 and L2 caches and another to go to 71 * the next level and so forth. 72 * 73 * Packets are assumed to be returned in the case of a single response. If 74 * the transaction has no response, then the consumer will delete the packet. 75 */ 76struct Packet 77{ 78 /** The address of the request, could be virtual or physical (depending on 79 cache configurations). */ 80 Addr addr; 81 82 /** Flag structure to hold flags for this particular packet */ 83 uint64_t flags; 84 85 /** A pointer to the overall request. */ 86 RequestPtr req; 87 88 /** A virtual base opaque structure used to hold 89 coherence status messages. */ 90 Coherence *coherence; // virtual base opaque, 91 // assert(dynamic_cast<Foo>) etc. 92 93 /** A virtual base opaque structure used to hold the senders state. */ 94 SenderState *senderState; // virtual base opaque, 95 // assert(dynamic_cast<Foo>) etc. 96 97 /** A pointer to the data being transfered. It can be differnt sizes 98 at each level of the heirarchy so it belongs in the packet, 99 not request*/ 100 PacketDataPtr data; 101 102 /** Indicates the size of the request. */ 103 int size; 104 105 /** A index of the source of the transaction. */ 106 short src; 107 108 /** A index to the destination of the transaction. */ 109 short dest; 110 111 /** The command of the transaction. */ 112 Command cmd; 113 114 /** The result of the packet transaction. */ 115 PacketResult result; 116 117 /** Accessor function that returns the source index of the packet. */ 118 short getSrc() const { return src; } 119 120 /** Accessor function that returns the destination index of 121 the packet. */ 122 short getDest() const { return dest; } 123}; 124 125#endif //__MEM_PACKET_HH 126