packet.hh revision 3156:2e6fc95d9ccf
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//20 for now. @todo fix later 63#define NUM_MEM_CMDS 1 << 9 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 HasData = 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,// | HasData, 188 WriteReqNoAck = IsWrite | IsRequest,// | HasData, 189 ReadResp = IsRead | IsResponse | NeedsResponse,// | HasData, 190 WriteResp = IsWrite | IsResponse | NeedsResponse, 191 Writeback = IsWrite | IsRequest,// | HasData, 192 SoftPFReq = IsRead | IsRequest | IsSWPrefetch | NeedsResponse, 193 HardPFReq = IsRead | IsRequest | IsHWPrefetch | NeedsResponse, 194 SoftPFResp = IsRead | IsResponse | IsSWPrefetch 195 | NeedsResponse,// | HasData, 196 HardPFResp = IsRead | IsResponse | IsHWPrefetch 197 | NeedsResponse,// | HasData, 198 InvalidateReq = IsInvalidate | IsRequest, 199 WriteInvalidateReq = IsWrite | IsInvalidate | IsRequest,// | HasData, 200 UpgradeReq = IsInvalidate | IsRequest | NeedsResponse, 201 UpgradeResp = IsInvalidate | IsResponse | NeedsResponse, 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 command or 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 cmd = (Command)icmd; 329 dest = src; 330 srcValid = false; 331 } 332 333 /** Take a request packet that has been returned as NACKED and modify it so 334 * that it can be sent out again. Only packets that need a response can be 335 * NACKED, so verify that that is true. */ 336 void reinitNacked() { 337 assert(needsResponse() && result == Nacked); 338 dest = Broadcast; 339 result = Unknown; 340 } 341 342 343 /** Set the data pointer to the following value that should not be freed. */ 344 template <typename T> 345 void dataStatic(T *p); 346 347 /** Set the data pointer to a value that should have delete [] called on it. 348 */ 349 template <typename T> 350 void dataDynamicArray(T *p); 351 352 /** set the data pointer to a value that should have delete called on it. */ 353 template <typename T> 354 void dataDynamic(T *p); 355 356 /** return the value of what is pointed to in the packet. */ 357 template <typename T> 358 T get(); 359 360 /** get a pointer to the data ptr. */ 361 template <typename T> 362 T* getPtr(); 363 364 /** set the value in the data pointer to v. */ 365 template <typename T> 366 void set(T v); 367 368 /** delete the data pointed to in the data pointer. Ok to call to matter how 369 * data was allocted. */ 370 void deleteData(); 371 372 /** If there isn't data in the packet, allocate some. */ 373 void allocate(); 374 375 /** Do the packet modify the same addresses. */ 376 bool intersect(Packet *p); 377}; 378 379bool fixPacket(Packet *func, Packet *timing); 380#endif //__MEM_PACKET_HH 381