packet.hh revision 2566
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 private: 80 /** A pointer to the data being transfered. It can be differnt sizes 81 at each level of the heirarchy so it belongs in the packet, 82 not request. This may or may not be populated when a responder recieves 83 the packet. If not populated it memory should be allocated. 84 */ 85 PacketDataPtr data; 86 87 /** Is the data pointer set to a value that shouldn't be freed when the 88 * packet is destroyed? */ 89 bool staticData; 90 /** The data pointer points to a value that should be freed when the packet 91 * is destroyed. */ 92 bool dynamicData; 93 /** the data pointer points to an array (thus delete [] ) needs to be called 94 * on it rather than simply delete.*/ 95 bool arrayData; 96 97 98 public: 99 /** The address of the request, could be virtual or physical (depending on 100 cache configurations). */ 101 Addr addr; 102 103 /** Flag structure to hold flags for this particular packet */ 104 uint64_t flags; 105 106 /** A pointer to the overall request. */ 107 RequestPtr req; 108 109 /** A virtual base opaque structure used to hold 110 coherence status messages. */ 111 Coherence *coherence; // virtual base opaque, 112 // assert(dynamic_cast<Foo>) etc. 113 114 /** A virtual base opaque structure used to hold the senders state. */ 115 void *senderState; // virtual base opaque, 116 // assert(dynamic_cast<Foo>) etc. 117 118 /** Indicates the size of the request. */ 119 int size; 120 121 /** A index of the source of the transaction. */ 122 short src; 123 124 /** A index to the destination of the transaction. */ 125 short dest; 126 127 /** The command of the transaction. */ 128 Command cmd; 129 130 /** The time this request was responded to. Used to calculate latencies. */ 131 Tick time; 132 133 /** The result of the packet transaction. */ 134 PacketResult result; 135 136 /** Accessor function that returns the source index of the packet. */ 137 short getSrc() const { return src; } 138 139 /** Accessor function that returns the destination index of 140 the packet. */ 141 short getDest() const { return dest; } 142 143 Packet() 144 : data(NULL), staticData(false), dynamicData(false), arrayData(false), 145 result(Unknown) 146 {} 147 148 ~Packet() 149 { deleteData(); } 150 151 152 /** Minimally reset a packet so something like simple cpu can reuse it. */ 153 void reset() { 154 result = Unknown; 155 if (dynamicData) { 156 deleteData(); 157 dynamicData = false; 158 arrayData = false; 159 } 160 } 161 162 /** Set the data pointer to the following value that should not be freed. */ 163 template <typename T> 164 void dataStatic(T *p) { 165 assert(!dynamicData); 166 data = (PacketDataPtr)p; 167 staticData = true; 168 } 169 170 /** Set the data pointer to a value that should have delete [] called on it. 171 */ 172 template <typename T> 173 void dataDynamicArray(T *p) { 174 assert(!staticData && !dynamicData); 175 data = (PacketDataPtr)p; 176 dynamicData = true; 177 arrayData = true; 178 } 179 180 /** set the data pointer to a value that should have delete called on it. */ 181 template <typename T> 182 void dataDynamic(T *p) { 183 assert(!staticData && !dynamicData); 184 data = (PacketDataPtr)p; 185 dynamicData = true; 186 arrayData = false; 187 } 188 189 /** return the value of what is pointed to in the packet. */ 190 template <typename T> 191 T get() { 192 assert(staticData || dynamicData); 193 assert(sizeof(T) <= size); 194 return *(T*)data; 195 } 196 197 /** get a pointer to the data ptr. */ 198 template <typename T> 199 T* getPtr() { 200 assert(staticData || dynamicData); 201 return (T*)data; 202 } 203 204 205 /** set the value in the data pointer to v. */ 206 template <typename T> 207 void set(T v) { 208 assert(sizeof(T) <= size); 209 *(T*)data = v; 210 } 211 212 /** delete the data pointed to in the data pointer. Ok to call to matter how 213 * data was allocted. */ 214 void deleteData() { 215 assert(staticData || dynamicData); 216 if (staticData) 217 return; 218 219 if (arrayData) 220 delete [] data; 221 else 222 delete data; 223 } 224 225 /** If there isn't data in the packet, allocate some. */ 226 void allocate() { 227 if (data) 228 return; 229 assert(!staticData); 230 dynamicData = true; 231 arrayData = true; 232 data = new uint8_t[size]; 233 } 234}; 235 236#endif //__MEM_PACKET_HH 237