packet.hh revision 3208
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 statistics we need max number of commands, hard code it at 62//for now. @todo fix later 63#define NUM_MEM_CMDS 1 << 10 64 65/** 66 * A Packet is used to encapsulate a transfer between two objects in 67 * the memory system (e.g., the L1 and L2 cache). (In contrast, a 68 * single Request travels all the way from the requester to the 69 * ultimate destination and back, possibly being conveyed by several 70 * different Packets along the way.) 71 */ 72class Packet 73{ 74 public: 75 /** Temporary FLAGS field until cache gets working, this should be in coherence/sender state. */ 76 uint64_t flags; 77 78 private: 79 /** A pointer to the data being transfered. It can be differnt 80 * sizes at each level of the heirarchy so it belongs in the 81 * packet, not request. This may or may not be populated when a 82 * responder recieves the packet. If not populated it memory 83 * should be allocated. 84 */ 85 PacketDataPtr data; 86 87 /** Is the data pointer set to a value that shouldn't be freed 88 * when the packet is destroyed? */ 89 bool staticData; 90 /** The data pointer points to a value that should be freed when 91 * the packet is destroyed. */ 92 bool dynamicData; 93 /** the data pointer points to an array (thus delete [] ) needs to 94 * be called on it rather than simply delete.*/ 95 bool arrayData; 96 97 98 /** The address of the request. This address could be virtual or 99 * physical, depending on the system configuration. */ 100 Addr addr; 101 102 /** The size of the request or transfer. */ 103 int size; 104 105 /** Device address (e.g., bus ID) of the source of the 106 * transaction. The source is not responsible for setting this 107 * field; it is set implicitly by the interconnect when the 108 * packet * is first sent. */ 109 short src; 110 111 /** Device address (e.g., bus ID) of the destination of the 112 * transaction. The special value Broadcast indicates that the 113 * packet should be routed based on its address. This field is 114 * initialized in the constructor and is thus always valid 115 * (unlike * addr, size, and src). */ 116 short dest; 117 118 /** Are the 'addr' and 'size' fields valid? */ 119 bool addrSizeValid; 120 /** Is the 'src' field valid? */ 121 bool srcValid; 122 123 124 public: 125 126 /** Used to calculate latencies for each packet.*/ 127 Tick time; 128 129 /** The special destination address indicating that the packet 130 * should be routed based on its address. */ 131 static const short Broadcast = -1; 132 133 /** A pointer to the original request. */ 134 RequestPtr req; 135 136 /** A virtual base opaque structure used to hold coherence-related 137 * state. A specific subclass would be derived from this to 138 * carry state specific to a particular coherence protocol. */ 139 class CoherenceState { 140 public: 141 virtual ~CoherenceState() {} 142 }; 143 144 /** This packet's coherence state. Caches should use 145 * dynamic_cast<> to cast to the state appropriate for the 146 * system's coherence protocol. */ 147 CoherenceState *coherence; 148 149 /** A virtual base opaque structure used to hold state associated 150 * with the packet but specific to the sending device (e.g., an 151 * MSHR). A pointer to this state is returned in the packet's 152 * response so that the sender can quickly look up the state 153 * needed to process it. A specific subclass would be derived 154 * from this to carry state specific to a particular sending 155 * device. */ 156 class SenderState { 157 public: 158 virtual ~SenderState() {} 159 }; 160 161 /** This packet's sender state. Devices should use dynamic_cast<> 162 * to cast to the state appropriate to the sender. */ 163 SenderState *senderState; 164 165 private: 166 /** List of command attributes. */ 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 }; 180 181 public: 182 /** List of all commands associated with a packet. */ 183 enum Command 184 { 185 InvalidCmd = 0, 186 ReadReq = IsRead | IsRequest | NeedsResponse, 187 WriteReq = IsWrite | IsRequest | NeedsResponse, 188 WriteReqNoAck = IsWrite | IsRequest, 189 ReadResp = IsRead | IsResponse | NeedsResponse, 190 WriteResp = IsWrite | IsResponse | NeedsResponse, 191 Writeback = IsWrite | IsRequest, 192 SoftPFReq = IsRead | IsRequest | IsSWPrefetch | NeedsResponse, 193 HardPFReq = IsRead | IsRequest | IsHWPrefetch | NeedsResponse, 194 SoftPFResp = IsRead | IsResponse | IsSWPrefetch | NeedsResponse, 195 HardPFResp = IsRead | IsResponse | IsHWPrefetch | NeedsResponse, 196 InvalidateReq = IsInvalidate | IsRequest, 197 WriteInvalidateReq = IsWrite | IsInvalidate | IsRequest, 198 UpgradeReq = IsInvalidate | IsRequest | IsUpgrade, 199 ReadExReq = IsRead | IsInvalidate | IsRequest | NeedsResponse, 200 ReadExResp = IsRead | IsInvalidate | IsResponse | NeedsResponse 201 }; 202 203 /** Return the string name of the cmd field (for debugging and 204 * tracing). */ 205 const std::string &cmdString() const; 206 207 /** Reutrn the string to a cmd given by idx. */ 208 const std::string &cmdIdxToString(Command idx); 209 210 /** Return the index of this command. */ 211 inline int cmdToIndex() const { return (int) cmd; } 212 213 /** The command field of the packet. */ 214 Command cmd; 215 216 bool isRead() { return (cmd & IsRead) != 0; } 217 bool isWrite() { return (cmd & IsWrite) != 0; } 218 bool isRequest() { return (cmd & IsRequest) != 0; } 219 bool isResponse() { return (cmd & IsResponse) != 0; } 220 bool needsResponse() { return (cmd & NeedsResponse) != 0; } 221 bool isInvalidate() { return (cmd & IsInvalidate) != 0; } 222 223 bool isCacheFill() { return (flags & CACHE_LINE_FILL) != 0; } 224 bool isNoAllocate() { return (flags & NO_ALLOCATE) != 0; } 225 bool isCompressed() { return (flags & COMPRESSED) != 0; } 226 227 bool nic_pkt() { assert("Unimplemented\n" && 0); return false; } 228 229 /** Possible results of a packet's request. */ 230 enum Result 231 { 232 Success, 233 BadAddress, 234 Nacked, 235 Unknown 236 }; 237 238 /** The result of this packet's request. */ 239 Result result; 240 241 /** Accessor function that returns the source index of the packet. */ 242 short getSrc() const { assert(srcValid); return src; } 243 void setSrc(short _src) { src = _src; srcValid = true; } 244 245 /** Accessor function that returns the destination index of 246 the packet. */ 247 short getDest() const { return dest; } 248 void setDest(short _dest) { dest = _dest; } 249 250 Addr getAddr() const { assert(addrSizeValid); return addr; } 251 int getSize() const { assert(addrSizeValid); return size; } 252 Addr getOffset(int blkSize) const { return addr & (Addr)(blkSize - 1); } 253 254 void addrOverride(Addr newAddr) { assert(addrSizeValid); addr = newAddr; } 255 void cmdOverride(Command newCmd) { cmd = newCmd; } 256 257 /** Constructor. Note that a Request object must be constructed 258 * first, but the Requests's physical address and size fields 259 * need not be valid. The command and destination addresses 260 * must be supplied. */ 261 Packet(Request *_req, Command _cmd, short _dest) 262 : data(NULL), staticData(false), dynamicData(false), arrayData(false), 263 addr(_req->paddr), size(_req->size), dest(_dest), 264 addrSizeValid(_req->validPaddr), 265 srcValid(false), 266 req(_req), coherence(NULL), senderState(NULL), cmd(_cmd), 267 result(Unknown) 268 { 269 flags = 0; 270 time = curTick; 271 } 272 273 /** Alternate constructor if you are trying to create a packet with 274 * a request that is for a whole block, not the address from the req. 275 * this allows for overriding the size/addr of the req.*/ 276 Packet(Request *_req, Command _cmd, short _dest, int _blkSize) 277 : data(NULL), staticData(false), dynamicData(false), arrayData(false), 278 addr(_req->paddr & ~(_blkSize - 1)), size(_blkSize), 279 dest(_dest), 280 addrSizeValid(_req->validPaddr), srcValid(false), 281 req(_req), coherence(NULL), senderState(NULL), cmd(_cmd), 282 result(Unknown) 283 { 284 flags = 0; 285 time = curTick; 286 } 287 288 /** Destructor. */ 289 ~Packet() 290 { deleteData(); } 291 292 /** Reinitialize packet address and size from the associated 293 * Request object, and reset other fields that may have been 294 * modified by a previous transaction. Typically called when a 295 * statically allocated Request/Packet pair is reused for 296 * multiple transactions. */ 297 void reinitFromRequest() { 298 assert(req->validPaddr); 299 addr = req->paddr; 300 size = req->size; 301 time = req->time; 302 addrSizeValid = true; 303 result = Unknown; 304 if (dynamicData) { 305 deleteData(); 306 dynamicData = false; 307 arrayData = false; 308 } 309 } 310 311 /** Take a request packet and modify it in place to be suitable 312 * for returning as a response to that request. Used for timing 313 * accesses only. For atomic and functional accesses, the 314 * request packet is always implicitly passed back *without* 315 * modifying the destination fields, so this function 316 * should not be called. */ 317 void makeTimingResponse() { 318 assert(needsResponse()); 319 assert(isRequest()); 320 int icmd = (int)cmd; 321 icmd &= ~(IsRequest); 322 icmd |= IsResponse; 323 cmd = (Command)icmd; 324 dest = src; 325 srcValid = false; 326 } 327 328 /** Take a request packet and modify it in place to be suitable 329 * for returning as a response to that request. 330 */ 331 void makeAtomicResponse() { 332 assert(needsResponse()); 333 assert(isRequest()); 334 int icmd = (int)cmd; 335 icmd &= ~(IsRequest); 336 icmd |= IsResponse; 337 cmd = (Command)icmd; 338 } 339 340 /** Take a request packet that has been returned as NACKED and modify it so 341 * that it can be sent out again. Only packets that need a response can be 342 * NACKED, so verify that that is true. */ 343 void reinitNacked() { 344 assert(needsResponse() && result == Nacked); 345 dest = Broadcast; 346 result = Unknown; 347 } 348 349 350 /** Set the data pointer to the following value that should not be freed. */ 351 template <typename T> 352 void dataStatic(T *p); 353 354 /** Set the data pointer to a value that should have delete [] called on it. 355 */ 356 template <typename T> 357 void dataDynamicArray(T *p); 358 359 /** set the data pointer to a value that should have delete called on it. */ 360 template <typename T> 361 void dataDynamic(T *p); 362 363 /** return the value of what is pointed to in the packet. */ 364 template <typename T> 365 T get(); 366 367 /** get a pointer to the data ptr. */ 368 template <typename T> 369 T* getPtr(); 370 371 /** set the value in the data pointer to v. */ 372 template <typename T> 373 void set(T v); 374 375 /** delete the data pointed to in the data pointer. Ok to call to matter how 376 * data was allocted. */ 377 void deleteData(); 378 379 /** If there isn't data in the packet, allocate some. */ 380 void allocate(); 381 382 /** Do the packet modify the same addresses. */ 383 bool intersect(Packet *p); 384}; 385 386bool fixPacket(Packet *func, Packet *timing); 387#endif //__MEM_PACKET_HH 388