packet.hh revision 3218
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 "sim/host.hh" 43#include "sim/root.hh" 44#include <list> 45#include <cassert> 46 47struct Packet; 48typedef Packet* PacketPtr; 49typedef uint8_t* PacketDataPtr; 50typedef std::list<PacketPtr> PacketList; 51 52//Coherence Flags 53#define NACKED_LINE 1 << 0 54#define SATISFIED 1 << 1 55#define SHARED_LINE 1 << 2 56#define CACHE_LINE_FILL 1 << 3 57#define COMPRESSED 1 << 4 58#define NO_ALLOCATE 1 << 5 59#define SNOOP_COMMIT 1 << 6 60 61/** 62 * A Packet is used to encapsulate a transfer between two objects in 63 * the memory system (e.g., the L1 and L2 cache). (In contrast, a 64 * single Request travels all the way from the requester to the 65 * ultimate destination and back, possibly being conveyed by several 66 * different Packets along the way.) 67 */ 68class Packet 69{ 70 public: 71 /** Temporary FLAGS field until cache gets working, this should be in coherence/sender state. */ 72 uint64_t flags; 73 74 private: 75 /** A pointer to the data being transfered. It can be differnt 76 * sizes at each level of the heirarchy so it belongs in the 77 * packet, not request. This may or may not be populated when a 78 * responder recieves the packet. If not populated it memory 79 * should be allocated. 80 */ 81 PacketDataPtr data; 82 83 /** Is the data pointer set to a value that shouldn't be freed 84 * when the packet is destroyed? */ 85 bool staticData; 86 /** The data pointer points to a value that should be freed when 87 * the packet is destroyed. */ 88 bool dynamicData; 89 /** the data pointer points to an array (thus delete [] ) needs to 90 * be called on it rather than simply delete.*/ 91 bool arrayData; 92 93 /** The address of the request. This address could be virtual or 94 * physical, depending on the system configuration. */ 95 Addr addr; 96 97 /** The size of the request or transfer. */ 98 int size; 99 100 /** Device address (e.g., bus ID) of the source of the 101 * transaction. The source is not responsible for setting this 102 * field; it is set implicitly by the interconnect when the 103 * packet * is first sent. */ 104 short src; 105 106 /** Device address (e.g., bus ID) of the destination of the 107 * transaction. The special value Broadcast indicates that the 108 * packet should be routed based on its address. This field is 109 * initialized in the constructor and is thus always valid 110 * (unlike * addr, size, and src). */ 111 short dest; 112 113 /** Are the 'addr' and 'size' fields valid? */ 114 bool addrSizeValid; 115 /** Is the 'src' field valid? */ 116 bool srcValid; 117 118 119 public: 120 121 /** Used to calculate latencies for each packet.*/ 122 Tick time; 123 124 /** The time at which the packet will be fully transmitted */ 125 Tick finishTime; 126 127 /** The time at which the first chunk of the packet will be transmitted */ 128 Tick firstWordTime; 129 130 /** The special destination address indicating that the packet 131 * should be routed based on its address. */ 132 static const short Broadcast = -1; 133 134 /** A pointer to the original request. */ 135 RequestPtr req; 136 137 /** A virtual base opaque structure used to hold coherence-related 138 * state. A specific subclass would be derived from this to 139 * carry state specific to a particular coherence protocol. */ 140 class CoherenceState { 141 public: 142 virtual ~CoherenceState() {} 143 }; 144 145 /** This packet's coherence state. Caches should use 146 * dynamic_cast<> to cast to the state appropriate for the 147 * system's coherence protocol. */ 148 CoherenceState *coherence; 149 150 /** A virtual base opaque structure used to hold state associated 151 * with the packet but specific to the sending device (e.g., an 152 * MSHR). A pointer to this state is returned in the packet's 153 * response so that the sender can quickly look up the state 154 * needed to process it. A specific subclass would be derived 155 * from this to carry state specific to a particular sending 156 * device. */ 157 class SenderState { 158 public: 159 virtual ~SenderState() {} 160 }; 161 162 /** This packet's sender state. Devices should use dynamic_cast<> 163 * to cast to the state appropriate to the sender. */ 164 SenderState *senderState; 165 166 private: 167 /** List of command attributes. */ 168 // If you add a new CommandAttribute, make sure to increase NUM_MEM_CMDS 169 // as well. 170 enum CommandAttribute 171 { 172 IsRead = 1 << 0, 173 IsWrite = 1 << 1, 174 IsPrefetch = 1 << 2, 175 IsInvalidate = 1 << 3, 176 IsRequest = 1 << 4, 177 IsResponse = 1 << 5, 178 NeedsResponse = 1 << 6, 179 IsSWPrefetch = 1 << 7, 180 IsHWPrefetch = 1 << 8, 181 HasData = 1 << 9 182 }; 183 184//For statistics we need max number of commands, hard code it at 185//20 for now. @todo fix later 186#define NUM_MEM_CMDS 1 << 10 187 188 public: 189 /** List of all commands associated with a packet. */ 190 enum Command 191 { 192 InvalidCmd = 0, 193 ReadReq = IsRead | IsRequest | NeedsResponse, 194 WriteReq = IsWrite | IsRequest | NeedsResponse | HasData, 195 WriteReqNoAck = IsWrite | IsRequest | HasData, 196 ReadResp = IsRead | IsResponse | NeedsResponse | HasData, 197 WriteResp = IsWrite | IsResponse | NeedsResponse, 198 Writeback = IsWrite | IsRequest | HasData, 199 SoftPFReq = IsRead | IsRequest | IsSWPrefetch | NeedsResponse, 200 HardPFReq = IsRead | IsRequest | IsHWPrefetch | NeedsResponse, 201 SoftPFResp = IsRead | IsResponse | IsSWPrefetch 202 | NeedsResponse | HasData, 203 HardPFResp = IsRead | IsResponse | IsHWPrefetch 204 | NeedsResponse | HasData, 205 InvalidateReq = IsInvalidate | IsRequest, 206 WriteInvalidateReq = IsWrite | IsInvalidate | IsRequest | HasData, 207 UpgradeReq = IsInvalidate | IsRequest, 208 ReadExReq = IsRead | IsInvalidate | IsRequest | NeedsResponse, 209 ReadExResp = IsRead | IsInvalidate | IsResponse 210 | NeedsResponse | HasData 211 }; 212 213 /** Return the string name of the cmd field (for debugging and 214 * tracing). */ 215 const std::string &cmdString() const; 216 217 /** Reutrn the string to a cmd given by idx. */ 218 const std::string &cmdIdxToString(Command idx); 219 220 /** Return the index of this command. */ 221 inline int cmdToIndex() const { return (int) cmd; } 222 223 /** The command field of the packet. */ 224 Command cmd; 225 226 bool isRead() { return (cmd & IsRead) != 0; } 227 bool isWrite() { return (cmd & IsWrite) != 0; } 228 bool isRequest() { return (cmd & IsRequest) != 0; } 229 bool isResponse() { return (cmd & IsResponse) != 0; } 230 bool needsResponse() { return (cmd & NeedsResponse) != 0; } 231 bool isInvalidate() { return (cmd & IsInvalidate) != 0; } 232 bool hasData() { return (cmd & HasData) != 0; } 233 234 bool isCacheFill() { return (flags & CACHE_LINE_FILL) != 0; } 235 bool isNoAllocate() { return (flags & NO_ALLOCATE) != 0; } 236 bool isCompressed() { return (flags & COMPRESSED) != 0; } 237 238 bool nic_pkt() { assert("Unimplemented\n" && 0); return false; } 239 240 /** Possible results of a packet's request. */ 241 enum Result 242 { 243 Success, 244 BadAddress, 245 Nacked, 246 Unknown 247 }; 248 249 /** The result of this packet's request. */ 250 Result result; 251 252 /** Accessor function that returns the source index of the packet. */ 253 short getSrc() const { assert(srcValid); return src; } 254 void setSrc(short _src) { src = _src; srcValid = true; } 255 256 /** Accessor function that returns the destination index of 257 the packet. */ 258 short getDest() const { return dest; } 259 void setDest(short _dest) { dest = _dest; } 260 261 Addr getAddr() const { assert(addrSizeValid); return addr; } 262 int getSize() const { assert(addrSizeValid); return size; } 263 Addr getOffset(int blkSize) const { return addr & (Addr)(blkSize - 1); } 264 265 void addrOverride(Addr newAddr) { assert(addrSizeValid); addr = newAddr; } 266 void cmdOverride(Command newCmd) { cmd = newCmd; } 267 268 /** Constructor. Note that a Request object must be constructed 269 * first, but the Requests's physical address and size fields 270 * need not be valid. The command and destination addresses 271 * must be supplied. */ 272 Packet(Request *_req, Command _cmd, short _dest) 273 : data(NULL), staticData(false), dynamicData(false), arrayData(false), 274 addr(_req->paddr), size(_req->size), dest(_dest), 275 addrSizeValid(_req->validPaddr), 276 srcValid(false), 277 req(_req), coherence(NULL), senderState(NULL), cmd(_cmd), 278 result(Unknown) 279 { 280 flags = 0; 281 time = curTick; 282 } 283 284 /** Alternate constructor if you are trying to create a packet with 285 * a request that is for a whole block, not the address from the req. 286 * this allows for overriding the size/addr of the req.*/ 287 Packet(Request *_req, Command _cmd, short _dest, int _blkSize) 288 : data(NULL), staticData(false), dynamicData(false), arrayData(false), 289 addr(_req->paddr & ~(_blkSize - 1)), size(_blkSize), 290 dest(_dest), 291 addrSizeValid(_req->validPaddr), srcValid(false), 292 req(_req), coherence(NULL), senderState(NULL), cmd(_cmd), 293 result(Unknown) 294 { 295 flags = 0; 296 time = curTick; 297 } 298 299 /** Destructor. */ 300 ~Packet() 301 { deleteData(); } 302 303 /** Reinitialize packet address and size from the associated 304 * Request object, and reset other fields that may have been 305 * modified by a previous transaction. Typically called when a 306 * statically allocated Request/Packet pair is reused for 307 * multiple transactions. */ 308 void reinitFromRequest() { 309 assert(req->validPaddr); 310 addr = req->paddr; 311 size = req->size; 312 time = req->time; 313 addrSizeValid = true; 314 result = Unknown; 315 if (dynamicData) { 316 deleteData(); 317 dynamicData = false; 318 arrayData = false; 319 } 320 } 321 322 /** Take a request packet and modify it in place to be suitable 323 * for returning as a response to that request. Used for timing 324 * accesses only. For atomic and functional accesses, the 325 * request packet is always implicitly passed back *without* 326 * modifying the destination fields, so this function 327 * should not be called. */ 328 void makeTimingResponse() { 329 assert(needsResponse()); 330 assert(isRequest()); 331 int icmd = (int)cmd; 332 icmd &= ~(IsRequest); 333 icmd |= IsResponse; 334 cmd = (Command)icmd; 335 dest = src; 336 srcValid = false; 337 } 338 339 /** Take a request packet and modify it in place to be suitable 340 * for returning as a response to that request. 341 */ 342 void makeAtomicResponse() { 343 assert(needsResponse()); 344 assert(isRequest()); 345 int icmd = (int)cmd; 346 icmd &= ~(IsRequest); 347 icmd |= IsResponse; 348 cmd = (Command)icmd; 349 } 350 351 /** Take a request packet that has been returned as NACKED and modify it so 352 * that it can be sent out again. Only packets that need a response can be 353 * NACKED, so verify that that is true. */ 354 void reinitNacked() { 355 assert(needsResponse() && result == Nacked); 356 dest = Broadcast; 357 result = Unknown; 358 } 359 360 361 /** Set the data pointer to the following value that should not be freed. */ 362 template <typename T> 363 void dataStatic(T *p); 364 365 /** Set the data pointer to a value that should have delete [] called on it. 366 */ 367 template <typename T> 368 void dataDynamicArray(T *p); 369 370 /** set the data pointer to a value that should have delete called on it. */ 371 template <typename T> 372 void dataDynamic(T *p); 373 374 /** return the value of what is pointed to in the packet. */ 375 template <typename T> 376 T get(); 377 378 /** get a pointer to the data ptr. */ 379 template <typename T> 380 T* getPtr(); 381 382 /** set the value in the data pointer to v. */ 383 template <typename T> 384 void set(T v); 385 386 /** delete the data pointed to in the data pointer. Ok to call to matter how 387 * data was allocted. */ 388 void deleteData(); 389 390 /** If there isn't data in the packet, allocate some. */ 391 void allocate(); 392 393 /** Do the packet modify the same addresses. */ 394 bool intersect(Packet *p); 395}; 396 397bool fixPacket(Packet *func, Packet *timing); 398#endif //__MEM_PACKET_HH 399