packet.hh revision 2641:6d9d837e2032
1/* 2 * Copyright (c) 2006 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/** 47 * A Packet is the structure to handle requests between two levels 48 * of the memory system. The Request is a global object that trancends 49 * all of the memory heirarchy, but at each levels interface a packet 50 * is created to transfer data/requests. For example, a request would 51 * be used to initiate a request to go to memory/IOdevices, as the request 52 * passes through the memory system several packets will be created. One 53 * will be created to go between the L1 and L2 caches and another to go to 54 * the next level and so forth. 55 * 56 * Packets are assumed to be returned in the case of a single response. If 57 * the transaction has no response, then the consumer will delete the packet. 58 */ 59class Packet 60{ 61 private: 62 /** A pointer to the data being transfered. It can be differnt sizes 63 at each level of the heirarchy so it belongs in the packet, 64 not request. This may or may not be populated when a responder recieves 65 the packet. If not populated it memory should be allocated. 66 */ 67 PacketDataPtr data; 68 69 /** Is the data pointer set to a value that shouldn't be freed when the 70 * packet is destroyed? */ 71 bool staticData; 72 /** The data pointer points to a value that should be freed when the packet 73 * is destroyed. */ 74 bool dynamicData; 75 /** the data pointer points to an array (thus delete [] ) needs to be called 76 * on it rather than simply delete.*/ 77 bool arrayData; 78 79 80 /** The address of the request, could be virtual or physical (depending on 81 cache configurations). */ 82 Addr addr; 83 84 /** Indicates the size of the request. */ 85 int size; 86 87 /** A index of the source of the transaction. */ 88 short src; 89 90 /** A index to the destination of the transaction. */ 91 short dest; 92 93 bool addrValid; 94 bool sizeValid; 95 bool srcValid; 96 97 public: 98 99 static const short Broadcast = -1; 100 101 /** A pointer to the overall request. */ 102 RequestPtr req; 103 104 class CoherenceState { 105 public: 106 virtual ~CoherenceState() {} 107 }; 108 109 /** A virtual base opaque structure used to hold 110 coherence status messages. */ 111 CoherenceState *coherence; // virtual base opaque, 112 // assert(dynamic_cast<Foo>) etc. 113 114 class SenderState { 115 public: 116 virtual ~SenderState() {} 117 }; 118 119 /** A virtual base opaque structure used to hold the senders state. */ 120 SenderState *senderState; // virtual base opaque, 121 // assert(dynamic_cast<Foo>) etc. 122 123 private: 124 /** List of command attributes. */ 125 enum CommandAttribute 126 { 127 IsRead = 1 << 0, 128 IsWrite = 1 << 1, 129 IsPrefetch = 1 << 2, 130 IsInvalidate = 1 << 3, 131 IsRequest = 1 << 4, 132 IsResponse = 1 << 5, 133 NeedsResponse = 1 << 6, 134 }; 135 136 public: 137 /** List of all commands associated with a packet. */ 138 enum Command 139 { 140 ReadReq = IsRead | IsRequest | NeedsResponse, 141 WriteReq = IsWrite | IsRequest | NeedsResponse, 142 WriteReqNoAck = IsWrite | IsRequest, 143 ReadResp = IsRead | IsResponse, 144 WriteResp = IsWrite | IsResponse 145 }; 146 147 const std::string &cmdString() const; 148 149 /** The command of the transaction. */ 150 Command cmd; 151 152 bool isRead() { return (cmd & IsRead) != 0; } 153 bool isRequest() { return (cmd & IsRequest) != 0; } 154 bool isResponse() { return (cmd & IsResponse) != 0; } 155 bool needsResponse() { return (cmd & NeedsResponse) != 0; } 156 157 void makeTimingResponse() { 158 assert(needsResponse()); 159 int icmd = (int)cmd; 160 icmd &= ~(IsRequest | NeedsResponse); 161 icmd |= IsResponse; 162 cmd = (Command)icmd; 163 dest = src; 164 srcValid = false; 165 } 166 167 /** The time this request was responded to. Used to calculate latencies. */ 168 Tick time; 169 170 /** The result of a particular packets request. */ 171 enum Result 172 { 173 Success, 174 BadAddress, 175 Unknown 176 }; 177 178 /** The result of the packet transaction. */ 179 Result result; 180 181 /** Accessor function that returns the source index of the packet. */ 182 short getSrc() const { assert(srcValid); return src; } 183 void setSrc(short _src) { src = _src; srcValid = true; } 184 185 /** Accessor function that returns the destination index of 186 the packet. */ 187 short getDest() const { return dest; } 188 void setDest(short _dest) { dest = _dest; } 189 190 Addr getAddr() const { assert(addrValid); return addr; } 191 void setAddr(Addr _addr) { addr = _addr; addrValid = true; } 192 193 int getSize() const { assert(sizeValid); return size; } 194 void setSize(int _size) { size = _size; sizeValid = true; } 195 196 197 Packet(Request *_req, Command _cmd, short _dest) 198 : data(NULL), staticData(false), dynamicData(false), arrayData(false), 199 addr(_req->paddr), size(_req->size), dest(_dest), 200 addrValid(_req->validPaddr), sizeValid(_req->validSize), 201 srcValid(false), 202 req(_req), coherence(NULL), senderState(NULL), cmd(_cmd), 203 time(curTick), result(Unknown) 204 { 205 } 206 207 ~Packet() 208 { deleteData(); } 209 210 211 /** Minimally reset a packet so something like simple cpu can reuse it. */ 212 void reset(); 213 214 void reinitFromRequest() { 215 if (req->validPaddr) setAddr(req->paddr); 216 if (req->validSize) setSize(req->size); 217 } 218 219 /** Set the data pointer to the following value that should not be freed. */ 220 template <typename T> 221 void dataStatic(T *p); 222 223 /** Set the data pointer to a value that should have delete [] called on it. 224 */ 225 template <typename T> 226 void dataDynamicArray(T *p); 227 228 /** set the data pointer to a value that should have delete called on it. */ 229 template <typename T> 230 void dataDynamic(T *p); 231 232 /** return the value of what is pointed to in the packet. */ 233 template <typename T> 234 T get(); 235 236 /** get a pointer to the data ptr. */ 237 template <typename T> 238 T* getPtr(); 239 240 /** set the value in the data pointer to v. */ 241 template <typename T> 242 void set(T v); 243 244 /** delete the data pointed to in the data pointer. Ok to call to matter how 245 * data was allocted. */ 246 void deleteData(); 247 248 /** If there isn't data in the packet, allocate some. */ 249 void allocate(); 250 251 /** Do the packet modify the same addresses. */ 252 bool intersect(Packet *p); 253}; 254 255bool fixPacket(Packet *func, Packet *timing); 256#endif //__MEM_PACKET_HH 257