packet.hh revision 2812
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 * Authors: Ron Dreslinski 29 * Steve Reinhardt 30 * Ali Saidi 31 */ 32 33/** 34 * @file 35 * Declaration of the Packet class. 36 */ 37 38#ifndef __MEM_PACKET_HH__ 39#define __MEM_PACKET_HH__ 40 41#include "mem/request.hh" 42#include "arch/isa_traits.hh" 43#include "sim/root.hh" 44#include <list> 45 46struct Packet; 47typedef Packet* PacketPtr; 48typedef uint8_t* PacketDataPtr; 49typedef std::list<PacketPtr> PacketList; 50 51//Coherence Flags 52#define NACKED_LINE 1 << 0 53#define SATISFIED 1 << 1 54#define SHARED_LINE 1 << 2 55 56//For statistics we need max number of commands, hard code it at 57//20 for now. @todo fix later 58#define NUM_MEM_CMDS 1 << 9 59 60/** 61 * A Packet is used to encapsulate a transfer between two objects in 62 * the memory system (e.g., the L1 and L2 cache). (In contrast, a 63 * single Request travels all the way from the requester to the 64 * ultimate destination and back, possibly being conveyed by several 65 * different Packets along the way.) 66 */ 67class Packet 68{ 69 private: 70 /** A pointer to the data being transfered. It can be differnt 71 * sizes at each level of the heirarchy so it belongs in the 72 * packet, not request. This may or may not be populated when a 73 * responder recieves the packet. If not populated it memory 74 * should be allocated. 75 */ 76 PacketDataPtr data; 77 78 /** Is the data pointer set to a value that shouldn't be freed 79 * when the packet is destroyed? */ 80 bool staticData; 81 /** The data pointer points to a value that should be freed when 82 * the packet is destroyed. */ 83 bool dynamicData; 84 /** the data pointer points to an array (thus delete [] ) needs to 85 * be called on it rather than simply delete.*/ 86 bool arrayData; 87 88 89 /** The address of the request. This address could be virtual or 90 * physical, depending on the system configuration. */ 91 Addr addr; 92 93 /** The size of the request or transfer. */ 94 int size; 95 96 /** Device address (e.g., bus ID) of the source of the 97 * transaction. The source is not responsible for setting this 98 * field; it is set implicitly by the interconnect when the 99 * packet * is first sent. */ 100 short src; 101 102 /** Device address (e.g., bus ID) of the destination of the 103 * transaction. The special value Broadcast indicates that the 104 * packet should be routed based on its address. This field is 105 * initialized in the constructor and is thus always valid 106 * (unlike * addr, size, and src). */ 107 short dest; 108 109 /** Are the 'addr' and 'size' fields valid? */ 110 bool addrSizeValid; 111 /** Is the 'src' field valid? */ 112 bool srcValid; 113 114 public: 115 116 /** Used to calculate latencies for each packet.*/ 117 Tick time; 118 119 /** The special destination address indicating that the packet 120 * should be routed based on its address. */ 121 static const short Broadcast = -1; 122 123 /** A pointer to the original request. */ 124 RequestPtr req; 125 126 /** A virtual base opaque structure used to hold coherence-related 127 * state. A specific subclass would be derived from this to 128 * carry state specific to a particular coherence protocol. */ 129 class CoherenceState { 130 public: 131 virtual ~CoherenceState() {} 132 }; 133 134 /** This packet's coherence state. Caches should use 135 * dynamic_cast<> to cast to the state appropriate for the 136 * system's coherence protocol. */ 137 CoherenceState *coherence; 138 139 /** A virtual base opaque structure used to hold state associated 140 * with the packet but specific to the sending device (e.g., an 141 * MSHR). A pointer to this state is returned in the packet's 142 * response so that the sender can quickly look up the state 143 * needed to process it. A specific subclass would be derived 144 * from this to carry state specific to a particular sending 145 * device. */ 146 class SenderState { 147 public: 148 virtual ~SenderState() {} 149 }; 150 151 /** This packet's sender state. Devices should use dynamic_cast<> 152 * to cast to the state appropriate to the sender. */ 153 SenderState *senderState; 154 155 private: 156 /** List of command attributes. */ 157 enum CommandAttribute 158 { 159 IsRead = 1 << 0, 160 IsWrite = 1 << 1, 161 IsPrefetch = 1 << 2, 162 IsInvalidate = 1 << 3, 163 IsRequest = 1 << 4, 164 IsResponse = 1 << 5, 165 NeedsResponse = 1 << 6, 166 IsSWPrefetch = 1 << 7, 167 IsHWPrefetch = 1 << 8 168 }; 169 170 public: 171 /** List of all commands associated with a packet. */ 172 enum Command 173 { 174 ReadReq = IsRead | IsRequest | NeedsResponse, 175 WriteReq = IsWrite | IsRequest | NeedsResponse, 176 WriteReqNoAck = IsWrite | IsRequest, 177 ReadResp = IsRead | IsResponse, 178 WriteResp = IsWrite | IsResponse, 179 Writeback = IsWrite | IsRequest, 180 SoftPFReq = IsRead | IsRequest | IsSWPrefetch | NeedsResponse, 181 HardPFReq = IsRead | IsRequest | IsHWPrefetch | NeedsResponse, 182 SoftPFResp = IsRead | IsRequest | IsSWPrefetch | IsResponse, 183 HardPFResp = IsRead | IsRequest | IsHWPrefetch | IsResponse, 184 InvalidateReq = IsInvalidate | IsRequest, 185 WriteInvalidateReq = IsWrite | IsInvalidate | IsRequest, 186 UpgradeReq = IsInvalidate | NeedsResponse 187 }; 188 189 /** Return the string name of the cmd field (for debugging and 190 * tracing). */ 191 const std::string &cmdString() const; 192 193 /** Reutrn the string to a cmd given by idx. */ 194 const std::string &cmdIdxToString(Command idx); 195 196 /** Return the index of this command. */ 197 inline int cmdToIndex() const { return (int) cmd; } 198 199 /** The command field of the packet. */ 200 Command cmd; 201 202 bool isRead() { return (cmd & IsRead) != 0; } 203 bool isWrite() { return (cmd & IsWrite) != 0; } 204 bool isRequest() { return (cmd & IsRequest) != 0; } 205 bool isResponse() { return (cmd & IsResponse) != 0; } 206 bool needsResponse() { return (cmd & NeedsResponse) != 0; } 207 bool isInvalidate() { return (cmd * IsInvalidate) != 0; } 208 209 bool isCacheFill() { assert("Unimplemented yet\n" && 0); } 210 bool isNoAllocate() { assert("Unimplemented yet\n" && 0); } 211 212 /** Possible results of a packet's request. */ 213 enum Result 214 { 215 Success, 216 BadAddress, 217 Nacked, 218 Unknown 219 }; 220 221 /** The result of this packet's request. */ 222 Result result; 223 224 /** Accessor function that returns the source index of the packet. */ 225 short getSrc() const { assert(srcValid); return src; } 226 void setSrc(short _src) { src = _src; srcValid = true; } 227 228 /** Accessor function that returns the destination index of 229 the packet. */ 230 short getDest() const { return dest; } 231 void setDest(short _dest) { dest = _dest; } 232 233 Addr getAddr() const { assert(addrSizeValid); return addr; } 234 int getSize() const { assert(addrSizeValid); return size; } 235 236 /** Constructor. Note that a Request object must be constructed 237 * first, but the Requests's physical address and size fields 238 * need not be valid. The command and destination addresses 239 * must be supplied. */ 240 Packet(Request *_req, Command _cmd, short _dest) 241 : data(NULL), staticData(false), dynamicData(false), arrayData(false), 242 addr(_req->paddr), size(_req->size), dest(_dest), 243 addrSizeValid(_req->validPaddr), 244 srcValid(false), 245 req(_req), coherence(NULL), senderState(NULL), cmd(_cmd), 246 result(Unknown) 247 { 248 } 249 250 /** Destructor. */ 251 ~Packet() 252 { deleteData(); } 253 254 /** Reinitialize packet address and size from the associated 255 * Request object, and reset other fields that may have been 256 * modified by a previous transaction. Typically called when a 257 * statically allocated Request/Packet pair is reused for 258 * multiple transactions. */ 259 void reinitFromRequest() { 260 assert(req->validPaddr); 261 addr = req->paddr; 262 size = req->size; 263 addrSizeValid = true; 264 result = Unknown; 265 if (dynamicData) { 266 deleteData(); 267 dynamicData = false; 268 arrayData = false; 269 } 270 } 271 272 /** Take a request packet and modify it in place to be suitable 273 * for returning as a response to that request. Used for timing 274 * accesses only. For atomic and functional accesses, the 275 * request packet is always implicitly passed back *without* 276 * modifying the command or destination fields, so this function 277 * should not be called. */ 278 void makeTimingResponse() { 279 assert(needsResponse()); 280 int icmd = (int)cmd; 281 icmd &= ~(IsRequest | NeedsResponse); 282 icmd |= IsResponse; 283 cmd = (Command)icmd; 284 dest = src; 285 srcValid = false; 286 } 287 288 /** Take a request packet that has been returned as NACKED and modify it so 289 * that it can be sent out again. Only packets that need a response can be 290 * NACKED, so verify that that is true. */ 291 void reinitNacked() { 292 assert(needsResponse() && result == Nacked); 293 dest = Broadcast; 294 result = Unknown; 295 } 296 297 298 /** Set the data pointer to the following value that should not be freed. */ 299 template <typename T> 300 void dataStatic(T *p); 301 302 /** Set the data pointer to a value that should have delete [] called on it. 303 */ 304 template <typename T> 305 void dataDynamicArray(T *p); 306 307 /** set the data pointer to a value that should have delete called on it. */ 308 template <typename T> 309 void dataDynamic(T *p); 310 311 /** return the value of what is pointed to in the packet. */ 312 template <typename T> 313 T get(); 314 315 /** get a pointer to the data ptr. */ 316 template <typename T> 317 T* getPtr(); 318 319 /** set the value in the data pointer to v. */ 320 template <typename T> 321 void set(T v); 322 323 /** delete the data pointed to in the data pointer. Ok to call to matter how 324 * data was allocted. */ 325 void deleteData(); 326 327 /** If there isn't data in the packet, allocate some. */ 328 void allocate(); 329 330 /** Do the packet modify the same addresses. */ 331 bool intersect(Packet *p); 332}; 333 334bool fixPacket(Packet *func, Packet *timing); 335#endif //__MEM_PACKET_HH 336