packet.hh revision 3217
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//for now. @todo fix later 62#define NUM_MEM_CMDS 1 << 11 63/** 64 * A Packet is used to encapsulate a transfer between two objects in 65 * the memory system (e.g., the L1 and L2 cache). (In contrast, a 66 * single Request travels all the way from the requester to the 67 * ultimate destination and back, possibly being conveyed by several 68 * different Packets along the way.) 69 */ 70class Packet 71{ 72 public: 73 /** Temporary FLAGS field until cache gets working, this should be in coherence/sender state. */ 74 uint64_t flags; 75 76 private: 77 /** A pointer to the data being transfered. It can be differnt 78 * sizes at each level of the heirarchy so it belongs in the 79 * packet, not request. This may or may not be populated when a 80 * responder recieves the packet. If not populated it memory 81 * should be allocated. 82 */ 83 PacketDataPtr data; 84 85 /** Is the data pointer set to a value that shouldn't be freed 86 * when the packet is destroyed? */ 87 bool staticData; 88 /** The data pointer points to a value that should be freed when 89 * the packet is destroyed. */ 90 bool dynamicData; 91 /** the data pointer points to an array (thus delete [] ) needs to 92 * be called on it rather than simply delete.*/ 93 bool arrayData; 94 95 96 /** The address of the request. This address could be virtual or 97 * physical, depending on the system configuration. */ 98 Addr addr; 99 100 /** The size of the request or transfer. */ 101 int size; 102 103 /** Device address (e.g., bus ID) of the source of the 104 * transaction. The source is not responsible for setting this 105 * field; it is set implicitly by the interconnect when the 106 * packet * is first sent. */ 107 short src; 108 109 /** Device address (e.g., bus ID) of the destination of the 110 * transaction. The special value Broadcast indicates that the 111 * packet should be routed based on its address. This field is 112 * initialized in the constructor and is thus always valid 113 * (unlike * addr, size, and src). */ 114 short dest; 115 116 /** Are the 'addr' and 'size' fields valid? */ 117 bool addrSizeValid; 118 /** Is the 'src' field valid? */ 119 bool srcValid; 120 121 122 public: 123 124 /** Used to calculate latencies for each packet.*/ 125 Tick time; 126 127 /** The special destination address indicating that the packet 128 * should be routed based on its address. */ 129 static const short Broadcast = -1; 130 131 /** A pointer to the original request. */ 132 RequestPtr req; 133 134 /** A virtual base opaque structure used to hold coherence-related 135 * state. A specific subclass would be derived from this to 136 * carry state specific to a particular coherence protocol. */ 137 class CoherenceState { 138 public: 139 virtual ~CoherenceState() {} 140 }; 141 142 /** This packet's coherence state. Caches should use 143 * dynamic_cast<> to cast to the state appropriate for the 144 * system's coherence protocol. */ 145 CoherenceState *coherence; 146 147 /** A virtual base opaque structure used to hold state associated 148 * with the packet but specific to the sending device (e.g., an 149 * MSHR). A pointer to this state is returned in the packet's 150 * response so that the sender can quickly look up the state 151 * needed to process it. A specific subclass would be derived 152 * from this to carry state specific to a particular sending 153 * device. */ 154 class SenderState { 155 public: 156 virtual ~SenderState() {} 157 }; 158 159 /** This packet's sender state. Devices should use dynamic_cast<> 160 * to cast to the state appropriate to the sender. */ 161 SenderState *senderState; 162 163 private: 164 /** List of command attributes. */ 165 // If you add a new CommandAttribute, make sure to increase NUM_MEM_CMDS 166 // as well. 167 enum CommandAttribute 168 { 169 IsRead = 1 << 0, 170 IsWrite = 1 << 1, 171 IsPrefetch = 1 << 2, 172 IsInvalidate = 1 << 3, 173 IsRequest = 1 << 4, 174 IsResponse = 1 << 5, 175 NeedsResponse = 1 << 6, 176 IsSWPrefetch = 1 << 7, 177 IsHWPrefetch = 1 << 8, 178 IsUpgrade = 1 << 9, 179 HasData = 1 << 10 180 }; 181 182 public: 183 /** List of all commands associated with a packet. */ 184 enum Command 185 { 186 InvalidCmd = 0, 187 ReadReq = IsRead | IsRequest | NeedsResponse, 188 WriteReq = IsWrite | IsRequest | NeedsResponse | HasData, 189 WriteReqNoAck = IsWrite | IsRequest | HasData, 190 ReadResp = IsRead | IsResponse | NeedsResponse | HasData, 191 WriteResp = IsWrite | IsResponse | NeedsResponse, 192 Writeback = IsWrite | IsRequest | HasData, 193 SoftPFReq = IsRead | IsRequest | IsSWPrefetch | NeedsResponse, 194 HardPFReq = IsRead | IsRequest | IsHWPrefetch | NeedsResponse, 195 SoftPFResp = IsRead | IsResponse | IsSWPrefetch 196 | NeedsResponse | HasData, 197 HardPFResp = IsRead | IsResponse | IsHWPrefetch 198 | NeedsResponse | HasData, 199 InvalidateReq = IsInvalidate | IsRequest, 200 WriteInvalidateReq = IsWrite | IsInvalidate | IsRequest | HasData, 201 UpgradeReq = IsInvalidate | IsRequest | IsUpgrade, 202 ReadExReq = IsRead | IsInvalidate | IsRequest | NeedsResponse, 203 ReadExResp = IsRead | IsInvalidate | IsResponse 204 | NeedsResponse | HasData 205 }; 206 207 /** Return the string name of the cmd field (for debugging and 208 * tracing). */ 209 const std::string &cmdString() const; 210 211 /** Reutrn the string to a cmd given by idx. */ 212 const std::string &cmdIdxToString(Command idx); 213 214 /** Return the index of this command. */ 215 inline int cmdToIndex() const { return (int) cmd; } 216 217 /** The command field of the packet. */ 218 Command cmd; 219 220 bool isRead() { return (cmd & IsRead) != 0; } 221 bool isWrite() { return (cmd & IsWrite) != 0; } 222 bool isRequest() { return (cmd & IsRequest) != 0; } 223 bool isResponse() { return (cmd & IsResponse) != 0; } 224 bool needsResponse() { return (cmd & NeedsResponse) != 0; } 225 bool isInvalidate() { return (cmd & IsInvalidate) != 0; } 226 bool hasData() { return (cmd & HasData) != 0; } 227 228 bool isCacheFill() { return (flags & CACHE_LINE_FILL) != 0; } 229 bool isNoAllocate() { return (flags & NO_ALLOCATE) != 0; } 230 bool isCompressed() { return (flags & COMPRESSED) != 0; } 231 232 bool nic_pkt() { assert("Unimplemented\n" && 0); return false; } 233 234 /** Possible results of a packet's request. */ 235 enum Result 236 { 237 Success, 238 BadAddress, 239 Nacked, 240 Unknown 241 }; 242 243 /** The result of this packet's request. */ 244 Result result; 245 246 /** Accessor function that returns the source index of the packet. */ 247 short getSrc() const { assert(srcValid); return src; } 248 void setSrc(short _src) { src = _src; srcValid = true; } 249 250 /** Accessor function that returns the destination index of 251 the packet. */ 252 short getDest() const { return dest; } 253 void setDest(short _dest) { dest = _dest; } 254 255 Addr getAddr() const { assert(addrSizeValid); return addr; } 256 int getSize() const { assert(addrSizeValid); return size; } 257 Addr getOffset(int blkSize) const { return addr & (Addr)(blkSize - 1); } 258 259 void addrOverride(Addr newAddr) { assert(addrSizeValid); addr = newAddr; } 260 void cmdOverride(Command newCmd) { cmd = newCmd; } 261 262 /** Constructor. Note that a Request object must be constructed 263 * first, but the Requests's physical address and size fields 264 * need not be valid. The command and destination addresses 265 * must be supplied. */ 266 Packet(Request *_req, Command _cmd, short _dest) 267 : data(NULL), staticData(false), dynamicData(false), arrayData(false), 268 addr(_req->paddr), size(_req->size), dest(_dest), 269 addrSizeValid(_req->validPaddr), 270 srcValid(false), 271 req(_req), coherence(NULL), senderState(NULL), cmd(_cmd), 272 result(Unknown) 273 { 274 flags = 0; 275 time = curTick; 276 } 277 278 /** Alternate constructor if you are trying to create a packet with 279 * a request that is for a whole block, not the address from the req. 280 * this allows for overriding the size/addr of the req.*/ 281 Packet(Request *_req, Command _cmd, short _dest, int _blkSize) 282 : data(NULL), staticData(false), dynamicData(false), arrayData(false), 283 addr(_req->paddr & ~(_blkSize - 1)), size(_blkSize), 284 dest(_dest), 285 addrSizeValid(_req->validPaddr), srcValid(false), 286 req(_req), coherence(NULL), senderState(NULL), cmd(_cmd), 287 result(Unknown) 288 { 289 flags = 0; 290 time = curTick; 291 } 292 293 /** Destructor. */ 294 ~Packet() 295 { deleteData(); } 296 297 /** Reinitialize packet address and size from the associated 298 * Request object, and reset other fields that may have been 299 * modified by a previous transaction. Typically called when a 300 * statically allocated Request/Packet pair is reused for 301 * multiple transactions. */ 302 void reinitFromRequest() { 303 assert(req->validPaddr); 304 addr = req->paddr; 305 size = req->size; 306 time = req->time; 307 addrSizeValid = true; 308 result = Unknown; 309 if (dynamicData) { 310 deleteData(); 311 dynamicData = false; 312 arrayData = false; 313 } 314 } 315 316 /** Take a request packet and modify it in place to be suitable 317 * for returning as a response to that request. Used for timing 318 * accesses only. For atomic and functional accesses, the 319 * request packet is always implicitly passed back *without* 320 * modifying the destination fields, so this function 321 * should not be called. */ 322 void makeTimingResponse() { 323 assert(needsResponse()); 324 assert(isRequest()); 325 int icmd = (int)cmd; 326 icmd &= ~(IsRequest); 327 icmd |= IsResponse; 328 if (isRead()) 329 icmd |= HasData; 330 if (isWrite()) 331 icmd &= ~HasData; 332 cmd = (Command)icmd; 333 dest = src; 334 srcValid = false; 335 } 336 337 /** Take a request packet and modify it in place to be suitable 338 * for returning as a response to that request. 339 */ 340 void makeAtomicResponse() { 341 assert(needsResponse()); 342 assert(isRequest()); 343 int icmd = (int)cmd; 344 icmd &= ~(IsRequest); 345 icmd |= IsResponse; 346 cmd = (Command)icmd; 347 } 348 349 /** Take a request packet that has been returned as NACKED and modify it so 350 * that it can be sent out again. Only packets that need a response can be 351 * NACKED, so verify that that is true. */ 352 void reinitNacked() { 353 assert(needsResponse() && result == Nacked); 354 dest = Broadcast; 355 result = Unknown; 356 } 357 358 359 /** Set the data pointer to the following value that should not be freed. */ 360 template <typename T> 361 void dataStatic(T *p); 362 363 /** Set the data pointer to a value that should have delete [] called on it. 364 */ 365 template <typename T> 366 void dataDynamicArray(T *p); 367 368 /** set the data pointer to a value that should have delete called on it. */ 369 template <typename T> 370 void dataDynamic(T *p); 371 372 /** return the value of what is pointed to in the packet. */ 373 template <typename T> 374 T get(); 375 376 /** get a pointer to the data ptr. */ 377 template <typename T> 378 T* getPtr(); 379 380 /** set the value in the data pointer to v. */ 381 template <typename T> 382 void set(T v); 383 384 /** delete the data pointed to in the data pointer. Ok to call to matter how 385 * data was allocted. */ 386 void deleteData(); 387 388 /** If there isn't data in the packet, allocate some. */ 389 void allocate(); 390 391 /** Do the packet modify the same addresses. */ 392 bool intersect(Packet *p); 393}; 394 395bool fixPacket(Packet *func, Packet *timing); 396#endif //__MEM_PACKET_HH 397