packet.hh revision 2568
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 time(curTick), 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 time = curTick; 160 } 161 } 162 163 /** Set the data pointer to the following value that should not be freed. */ 164 template <typename T> 165 void dataStatic(T *p) { 166 assert(!dynamicData); 167 data = (PacketDataPtr)p; 168 staticData = true; 169 } 170 171 /** Set the data pointer to a value that should have delete [] called on it. 172 */ 173 template <typename T> 174 void dataDynamicArray(T *p) { 175 assert(!staticData && !dynamicData); 176 data = (PacketDataPtr)p; 177 dynamicData = true; 178 arrayData = true; 179 } 180 181 /** set the data pointer to a value that should have delete called on it. */ 182 template <typename T> 183 void dataDynamic(T *p) { 184 assert(!staticData && !dynamicData); 185 data = (PacketDataPtr)p; 186 dynamicData = true; 187 arrayData = false; 188 } 189 190 /** return the value of what is pointed to in the packet. */ 191 template <typename T> 192 T get() { 193 assert(staticData || dynamicData); 194 assert(sizeof(T) <= size); 195 return *(T*)data; 196 } 197 198 /** get a pointer to the data ptr. */ 199 template <typename T> 200 T* getPtr() { 201 assert(staticData || dynamicData); 202 return (T*)data; 203 } 204 205 206 /** set the value in the data pointer to v. */ 207 template <typename T> 208 void set(T v) { 209 assert(sizeof(T) <= size); 210 *(T*)data = v; 211 } 212 213 /** delete the data pointed to in the data pointer. Ok to call to matter how 214 * data was allocted. */ 215 void deleteData() { 216 assert(staticData || dynamicData); 217 if (staticData) 218 return; 219 220 if (arrayData) 221 delete [] data; 222 else 223 delete data; 224 } 225 226 /** If there isn't data in the packet, allocate some. */ 227 void allocate() { 228 if (data) 229 return; 230 assert(!staticData); 231 dynamicData = true; 232 arrayData = true; 233 data = new uint8_t[size]; 234 } 235 236 /** Do the packet modify the same addresses. */ 237 bool intersect(Packet *p) { 238 Addr s1 = addr; 239 Addr e1 = addr + size; 240 Addr s2 = p->addr; 241 Addr e2 = p->addr + p->size; 242 243 if (s1 >= s2 && s1 < e2) 244 return true; 245 if (e1 >= s2 && e1 < e2) 246 return true; 247 return false; 248 } 249}; 250 251bool fixPacket(Packet &func, Packet &timing); 252#endif //__MEM_PACKET_HH 253