packet.hh revision 3039
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 60//For statistics we need max number of commands, hard code it at 61//20 for now. @todo fix later 62#define NUM_MEM_CMDS 1 << 9 63 64/** 65 * A Packet is used to encapsulate a transfer between two objects in 66 * the memory system (e.g., the L1 and L2 cache). (In contrast, a 67 * single Request travels all the way from the requester to the 68 * ultimate destination and back, possibly being conveyed by several 69 * different Packets along the way.) 70 */ 71class Packet 72{ 73 public: 74 /** Temporary FLAGS field until cache gets working, this should be in coherence/sender state. */ 75 uint64_t flags; 76 77 private: 78 /** A pointer to the data being transfered. It can be differnt 79 * sizes at each level of the heirarchy so it belongs in the 80 * packet, not request. This may or may not be populated when a 81 * responder recieves the packet. If not populated it memory 82 * should be allocated. 83 */ 84 PacketDataPtr data; 85 86 /** Is the data pointer set to a value that shouldn't be freed 87 * when the packet is destroyed? */ 88 bool staticData; 89 /** The data pointer points to a value that should be freed when 90 * the packet is destroyed. */ 91 bool dynamicData; 92 /** the data pointer points to an array (thus delete [] ) needs to 93 * be called on it rather than simply delete.*/ 94 bool arrayData; 95 96 97 /** The address of the request. This address could be virtual or 98 * physical, depending on the system configuration. */ 99 Addr addr; 100 101 /** The size of the request or transfer. */ 102 int size; 103 104 /** Device address (e.g., bus ID) of the source of the 105 * transaction. The source is not responsible for setting this 106 * field; it is set implicitly by the interconnect when the 107 * packet * is first sent. */ 108 short src; 109 110 /** Device address (e.g., bus ID) of the destination of the 111 * transaction. The special value Broadcast indicates that the 112 * packet should be routed based on its address. This field is 113 * initialized in the constructor and is thus always valid 114 * (unlike * addr, size, and src). */ 115 short dest; 116 117 /** Are the 'addr' and 'size' fields valid? */ 118 bool addrSizeValid; 119 /** Is the 'src' field valid? */ 120 bool srcValid; 121 122 123 public: 124 125 /** Used to calculate latencies for each packet.*/ 126 Tick time; 127 128 /** The special destination address indicating that the packet 129 * should be routed based on its address. */ 130 static const short Broadcast = -1; 131 132 /** A pointer to the original request. */ 133 RequestPtr req; 134 135 /** A virtual base opaque structure used to hold coherence-related 136 * state. A specific subclass would be derived from this to 137 * carry state specific to a particular coherence protocol. */ 138 class CoherenceState { 139 public: 140 virtual ~CoherenceState() {} 141 }; 142 143 /** This packet's coherence state. Caches should use 144 * dynamic_cast<> to cast to the state appropriate for the 145 * system's coherence protocol. */ 146 CoherenceState *coherence; 147 148 /** A virtual base opaque structure used to hold state associated 149 * with the packet but specific to the sending device (e.g., an 150 * MSHR). A pointer to this state is returned in the packet's 151 * response so that the sender can quickly look up the state 152 * needed to process it. A specific subclass would be derived 153 * from this to carry state specific to a particular sending 154 * device. */ 155 class SenderState { 156 public: 157 virtual ~SenderState() {} 158 }; 159 160 /** This packet's sender state. Devices should use dynamic_cast<> 161 * to cast to the state appropriate to the sender. */ 162 SenderState *senderState; 163 164 private: 165 /** List of command attributes. */ 166 enum CommandAttribute 167 { 168 IsRead = 1 << 0, 169 IsWrite = 1 << 1, 170 IsPrefetch = 1 << 2, 171 IsInvalidate = 1 << 3, 172 IsRequest = 1 << 4, 173 IsResponse = 1 << 5, 174 NeedsResponse = 1 << 6, 175 IsSWPrefetch = 1 << 7, 176 IsHWPrefetch = 1 << 8 177 }; 178 179 public: 180 /** List of all commands associated with a packet. */ 181 enum Command 182 { 183 InvalidCmd = 0, 184 ReadReq = IsRead | IsRequest | NeedsResponse, 185 WriteReq = IsWrite | IsRequest | NeedsResponse, 186 WriteReqNoAck = IsWrite | IsRequest, 187 ReadResp = IsRead | IsResponse | NeedsResponse, 188 WriteResp = IsWrite | IsResponse | NeedsResponse, 189 Writeback = IsWrite | IsRequest, 190 SoftPFReq = IsRead | IsRequest | IsSWPrefetch | NeedsResponse, 191 HardPFReq = IsRead | IsRequest | IsHWPrefetch | NeedsResponse, 192 SoftPFResp = IsRead | IsResponse | IsSWPrefetch | NeedsResponse, 193 HardPFResp = IsRead | IsResponse | IsHWPrefetch | NeedsResponse, 194 InvalidateReq = IsInvalidate | IsRequest, 195 WriteInvalidateReq = IsWrite | IsInvalidate | IsRequest, 196 UpgradeReq = IsInvalidate | IsRequest | NeedsResponse, 197 UpgradeResp = IsInvalidate | IsResponse | NeedsResponse, 198 ReadExReq = IsRead | IsInvalidate | IsRequest | NeedsResponse, 199 ReadExResp = IsRead | IsInvalidate | IsResponse | NeedsResponse 200 }; 201 202 /** Return the string name of the cmd field (for debugging and 203 * tracing). */ 204 const std::string &cmdString() const; 205 206 /** Reutrn the string to a cmd given by idx. */ 207 const std::string &cmdIdxToString(Command idx); 208 209 /** Return the index of this command. */ 210 inline int cmdToIndex() const { return (int) cmd; } 211 212 /** The command field of the packet. */ 213 Command cmd; 214 215 bool isRead() { return (cmd & IsRead) != 0; } 216 bool isWrite() { return (cmd & IsWrite) != 0; } 217 bool isRequest() { return (cmd & IsRequest) != 0; } 218 bool isResponse() { return (cmd & IsResponse) != 0; } 219 bool needsResponse() { return (cmd & NeedsResponse) != 0; } 220 bool isInvalidate() { return (cmd & IsInvalidate) != 0; } 221 222 bool isCacheFill() { return (flags & CACHE_LINE_FILL) != 0; } 223 bool isNoAllocate() { return (flags & NO_ALLOCATE) != 0; } 224 bool isCompressed() { return (flags & COMPRESSED) != 0; } 225 226 bool nic_pkt() { assert("Unimplemented\n" && 0); return false; } 227 228 /** Possible results of a packet's request. */ 229 enum Result 230 { 231 Success, 232 BadAddress, 233 Nacked, 234 Unknown 235 }; 236 237 /** The result of this packet's request. */ 238 Result result; 239 240 /** Accessor function that returns the source index of the packet. */ 241 short getSrc() const { assert(srcValid); return src; } 242 void setSrc(short _src) { src = _src; srcValid = true; } 243 244 /** Accessor function that returns the destination index of 245 the packet. */ 246 short getDest() const { return dest; } 247 void setDest(short _dest) { dest = _dest; } 248 249 Addr getAddr() const { assert(addrSizeValid); return addr; } 250 int getSize() const { assert(addrSizeValid); return size; } 251 Addr getOffset(int blkSize) const { return addr & (Addr)(blkSize - 1); } 252 253 void addrOverride(Addr newAddr) { assert(addrSizeValid); addr = newAddr; } 254 void cmdOverride(Command newCmd) { cmd = newCmd; } 255 256 /** Constructor. Note that a Request object must be constructed 257 * first, but the Requests's physical address and size fields 258 * need not be valid. The command and destination addresses 259 * must be supplied. */ 260 Packet(Request *_req, Command _cmd, short _dest) 261 : data(NULL), staticData(false), dynamicData(false), arrayData(false), 262 addr(_req->paddr), size(_req->size), dest(_dest), 263 addrSizeValid(_req->validPaddr), 264 srcValid(false), 265 req(_req), coherence(NULL), senderState(NULL), cmd(_cmd), 266 result(Unknown) 267 { 268 flags = 0; 269 } 270 271 /** Alternate constructor if you are trying to create a packet with 272 * a request that is for a whole block, not the address from the req. 273 * this allows for overriding the size/addr of the req.*/ 274 Packet(Request *_req, Command _cmd, short _dest, int _blkSize) 275 : data(NULL), staticData(false), dynamicData(false), arrayData(false), 276 addr(_req->paddr & ~(_blkSize - 1)), size(_blkSize), 277 dest(_dest), 278 addrSizeValid(_req->validPaddr), srcValid(false), 279 req(_req), coherence(NULL), senderState(NULL), cmd(_cmd), 280 result(Unknown) 281 { 282 flags = 0; 283 } 284 285 /** Destructor. */ 286 ~Packet() 287 { deleteData(); } 288 289 /** Reinitialize packet address and size from the associated 290 * Request object, and reset other fields that may have been 291 * modified by a previous transaction. Typically called when a 292 * statically allocated Request/Packet pair is reused for 293 * multiple transactions. */ 294 void reinitFromRequest() { 295 assert(req->validPaddr); 296 addr = req->paddr; 297 size = req->size; 298 addrSizeValid = true; 299 result = Unknown; 300 if (dynamicData) { 301 deleteData(); 302 dynamicData = false; 303 arrayData = false; 304 } 305 } 306 307 /** Take a request packet and modify it in place to be suitable 308 * for returning as a response to that request. Used for timing 309 * accesses only. For atomic and functional accesses, the 310 * request packet is always implicitly passed back *without* 311 * modifying the command or destination fields, so this function 312 * should not be called. */ 313 void makeTimingResponse() { 314 assert(needsResponse()); 315 assert(isRequest()); 316 int icmd = (int)cmd; 317 icmd &= ~(IsRequest); 318 icmd |= IsResponse; 319 cmd = (Command)icmd; 320 dest = src; 321 srcValid = false; 322 } 323 324 /** Take a request packet that has been returned as NACKED and modify it so 325 * that it can be sent out again. Only packets that need a response can be 326 * NACKED, so verify that that is true. */ 327 void reinitNacked() { 328 assert(needsResponse() && result == Nacked); 329 dest = Broadcast; 330 result = Unknown; 331 } 332 333 334 /** Set the data pointer to the following value that should not be freed. */ 335 template <typename T> 336 void dataStatic(T *p); 337 338 /** Set the data pointer to a value that should have delete [] called on it. 339 */ 340 template <typename T> 341 void dataDynamicArray(T *p); 342 343 /** set the data pointer to a value that should have delete called on it. */ 344 template <typename T> 345 void dataDynamic(T *p); 346 347 /** return the value of what is pointed to in the packet. */ 348 template <typename T> 349 T get(); 350 351 /** get a pointer to the data ptr. */ 352 template <typename T> 353 T* getPtr(); 354 355 /** set the value in the data pointer to v. */ 356 template <typename T> 357 void set(T v); 358 359 /** delete the data pointed to in the data pointer. Ok to call to matter how 360 * data was allocted. */ 361 void deleteData(); 362 363 /** If there isn't data in the packet, allocate some. */ 364 void allocate(); 365 366 /** Do the packet modify the same addresses. */ 367 bool intersect(Packet *p); 368}; 369 370bool fixPacket(Packet *func, Packet *timing); 371#endif //__MEM_PACKET_HH 372