packet.hh revision 11306:a5340a2a24f9
1/* 2 * Copyright (c) 2012-2015 ARM Limited 3 * All rights reserved 4 * 5 * The license below extends only to copyright in the software and shall 6 * not be construed as granting a license to any other intellectual 7 * property including but not limited to intellectual property relating 8 * to a hardware implementation of the functionality of the software 9 * licensed hereunder. You may use the software subject to the license 10 * terms below provided that you ensure that this notice is replicated 11 * unmodified and in its entirety in all distributions of the software, 12 * modified or unmodified, in source code or in binary form. 13 * 14 * Copyright (c) 2006 The Regents of The University of Michigan 15 * Copyright (c) 2010,2015 Advanced Micro Devices, Inc. 16 * All rights reserved. 17 * 18 * Redistribution and use in source and binary forms, with or without 19 * modification, are permitted provided that the following conditions are 20 * met: redistributions of source code must retain the above copyright 21 * notice, this list of conditions and the following disclaimer; 22 * redistributions in binary form must reproduce the above copyright 23 * notice, this list of conditions and the following disclaimer in the 24 * documentation and/or other materials provided with the distribution; 25 * neither the name of the copyright holders nor the names of its 26 * contributors may be used to endorse or promote products derived from 27 * this software without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 30 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 31 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 32 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 33 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 34 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 35 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 36 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 37 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 38 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 39 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 40 * 41 * Authors: Ron Dreslinski 42 * Steve Reinhardt 43 * Ali Saidi 44 * Andreas Hansson 45 */ 46 47/** 48 * @file 49 * Declaration of the Packet class. 50 */ 51 52#ifndef __MEM_PACKET_HH__ 53#define __MEM_PACKET_HH__ 54 55#include <bitset> 56#include <cassert> 57#include <list> 58 59#include "base/cast.hh" 60#include "base/compiler.hh" 61#include "base/flags.hh" 62#include "base/misc.hh" 63#include "base/printable.hh" 64#include "base/types.hh" 65#include "mem/request.hh" 66#include "sim/core.hh" 67 68class Packet; 69typedef Packet *PacketPtr; 70typedef uint8_t* PacketDataPtr; 71typedef std::list<PacketPtr> PacketList; 72 73class MemCmd 74{ 75 friend class Packet; 76 77 public: 78 /** 79 * List of all commands associated with a packet. 80 */ 81 enum Command 82 { 83 InvalidCmd, 84 ReadReq, 85 ReadResp, 86 ReadRespWithInvalidate, 87 WriteReq, 88 WriteResp, 89 WritebackDirty, 90 WritebackClean, 91 CleanEvict, 92 SoftPFReq, 93 HardPFReq, 94 SoftPFResp, 95 HardPFResp, 96 WriteLineReq, 97 UpgradeReq, 98 SCUpgradeReq, // Special "weak" upgrade for StoreCond 99 UpgradeResp, 100 SCUpgradeFailReq, // Failed SCUpgradeReq in MSHR (never sent) 101 UpgradeFailResp, // Valid for SCUpgradeReq only 102 ReadExReq, 103 ReadExResp, 104 ReadCleanReq, 105 ReadSharedReq, 106 LoadLockedReq, 107 StoreCondReq, 108 StoreCondFailReq, // Failed StoreCondReq in MSHR (never sent) 109 StoreCondResp, 110 SwapReq, 111 SwapResp, 112 MessageReq, 113 MessageResp, 114 MemFenceReq, 115 MemFenceResp, 116 // Error responses 117 // @TODO these should be classified as responses rather than 118 // requests; coding them as requests initially for backwards 119 // compatibility 120 InvalidDestError, // packet dest field invalid 121 BadAddressError, // memory address invalid 122 FunctionalReadError, // unable to fulfill functional read 123 FunctionalWriteError, // unable to fulfill functional write 124 // Fake simulator-only commands 125 PrintReq, // Print state matching address 126 FlushReq, //request for a cache flush 127 InvalidateReq, // request for address to be invalidated 128 InvalidateResp, 129 NUM_MEM_CMDS 130 }; 131 132 private: 133 /** 134 * List of command attributes. 135 */ 136 enum Attribute 137 { 138 IsRead, //!< Data flows from responder to requester 139 IsWrite, //!< Data flows from requester to responder 140 IsUpgrade, 141 IsInvalidate, 142 NeedsWritable, //!< Requires writable copy to complete in-cache 143 IsRequest, //!< Issued by requester 144 IsResponse, //!< Issue by responder 145 NeedsResponse, //!< Requester needs response from target 146 IsEviction, 147 IsSWPrefetch, 148 IsHWPrefetch, 149 IsLlsc, //!< Alpha/MIPS LL or SC access 150 HasData, //!< There is an associated payload 151 IsError, //!< Error response 152 IsPrint, //!< Print state matching address (for debugging) 153 IsFlush, //!< Flush the address from caches 154 NUM_COMMAND_ATTRIBUTES 155 }; 156 157 /** 158 * Structure that defines attributes and other data associated 159 * with a Command. 160 */ 161 struct CommandInfo 162 { 163 /// Set of attribute flags. 164 const std::bitset<NUM_COMMAND_ATTRIBUTES> attributes; 165 /// Corresponding response for requests; InvalidCmd if no 166 /// response is applicable. 167 const Command response; 168 /// String representation (for printing) 169 const std::string str; 170 }; 171 172 /// Array to map Command enum to associated info. 173 static const CommandInfo commandInfo[]; 174 175 private: 176 177 Command cmd; 178 179 bool 180 testCmdAttrib(MemCmd::Attribute attrib) const 181 { 182 return commandInfo[cmd].attributes[attrib] != 0; 183 } 184 185 public: 186 187 bool isRead() const { return testCmdAttrib(IsRead); } 188 bool isWrite() const { return testCmdAttrib(IsWrite); } 189 bool isUpgrade() const { return testCmdAttrib(IsUpgrade); } 190 bool isRequest() const { return testCmdAttrib(IsRequest); } 191 bool isResponse() const { return testCmdAttrib(IsResponse); } 192 bool needsWritable() const { return testCmdAttrib(NeedsWritable); } 193 bool needsResponse() const { return testCmdAttrib(NeedsResponse); } 194 bool isInvalidate() const { return testCmdAttrib(IsInvalidate); } 195 bool isEviction() const { return testCmdAttrib(IsEviction); } 196 197 /** 198 * A writeback is an eviction that carries data. 199 */ 200 bool isWriteback() const { return testCmdAttrib(IsEviction) && 201 testCmdAttrib(HasData); } 202 203 /** 204 * Check if this particular packet type carries payload data. Note 205 * that this does not reflect if the data pointer of the packet is 206 * valid or not. 207 */ 208 bool hasData() const { return testCmdAttrib(HasData); } 209 bool isLLSC() const { return testCmdAttrib(IsLlsc); } 210 bool isSWPrefetch() const { return testCmdAttrib(IsSWPrefetch); } 211 bool isHWPrefetch() const { return testCmdAttrib(IsHWPrefetch); } 212 bool isPrefetch() const { return testCmdAttrib(IsSWPrefetch) || 213 testCmdAttrib(IsHWPrefetch); } 214 bool isError() const { return testCmdAttrib(IsError); } 215 bool isPrint() const { return testCmdAttrib(IsPrint); } 216 bool isFlush() const { return testCmdAttrib(IsFlush); } 217 218 Command 219 responseCommand() const 220 { 221 return commandInfo[cmd].response; 222 } 223 224 /// Return the string to a cmd given by idx. 225 const std::string &toString() const { return commandInfo[cmd].str; } 226 int toInt() const { return (int)cmd; } 227 228 MemCmd(Command _cmd) : cmd(_cmd) { } 229 MemCmd(int _cmd) : cmd((Command)_cmd) { } 230 MemCmd() : cmd(InvalidCmd) { } 231 232 bool operator==(MemCmd c2) const { return (cmd == c2.cmd); } 233 bool operator!=(MemCmd c2) const { return (cmd != c2.cmd); } 234}; 235 236/** 237 * A Packet is used to encapsulate a transfer between two objects in 238 * the memory system (e.g., the L1 and L2 cache). (In contrast, a 239 * single Request travels all the way from the requester to the 240 * ultimate destination and back, possibly being conveyed by several 241 * different Packets along the way.) 242 */ 243class Packet : public Printable 244{ 245 public: 246 typedef uint32_t FlagsType; 247 typedef ::Flags<FlagsType> Flags; 248 249 private: 250 251 enum : FlagsType { 252 // Flags to transfer across when copying a packet 253 COPY_FLAGS = 0x0000000F, 254 255 // Does this packet have sharers (which means it should not be 256 // considered writable) or not. See setHasSharers below. 257 HAS_SHARERS = 0x00000001, 258 259 // Special control flags 260 /// Special timing-mode atomic snoop for multi-level coherence. 261 EXPRESS_SNOOP = 0x00000002, 262 263 /// Allow a responding cache to inform the cache hierarchy 264 /// that it had a writable copy before responding. See 265 /// setResponderHadWritable below. 266 RESPONDER_HAD_WRITABLE = 0x00000004, 267 268 // Snoop co-ordination flag to indicate that a cache is 269 // responding to a snoop. See setCacheResponding below. 270 CACHE_RESPONDING = 0x00000008, 271 272 /// Are the 'addr' and 'size' fields valid? 273 VALID_ADDR = 0x00000100, 274 VALID_SIZE = 0x00000200, 275 276 /// Is the data pointer set to a value that shouldn't be freed 277 /// when the packet is destroyed? 278 STATIC_DATA = 0x00001000, 279 /// The data pointer points to a value that should be freed when 280 /// the packet is destroyed. The pointer is assumed to be pointing 281 /// to an array, and delete [] is consequently called 282 DYNAMIC_DATA = 0x00002000, 283 284 /// suppress the error if this packet encounters a functional 285 /// access failure. 286 SUPPRESS_FUNC_ERROR = 0x00008000, 287 288 // Signal block present to squash prefetch and cache evict packets 289 // through express snoop flag 290 BLOCK_CACHED = 0x00010000 291 }; 292 293 Flags flags; 294 295 public: 296 typedef MemCmd::Command Command; 297 298 /// The command field of the packet. 299 MemCmd cmd; 300 301 /// A pointer to the original request. 302 const RequestPtr req; 303 304 private: 305 /** 306 * A pointer to the data being transfered. It can be differnt 307 * sizes at each level of the heirarchy so it belongs in the 308 * packet, not request. This may or may not be populated when a 309 * responder recieves the packet. If not populated it memory should 310 * be allocated. 311 */ 312 PacketDataPtr data; 313 314 /// The address of the request. This address could be virtual or 315 /// physical, depending on the system configuration. 316 Addr addr; 317 318 /// True if the request targets the secure memory space. 319 bool _isSecure; 320 321 /// The size of the request or transfer. 322 unsigned size; 323 324 /** 325 * Track the bytes found that satisfy a functional read. 326 */ 327 std::vector<bool> bytesValid; 328 329 public: 330 331 /** 332 * The extra delay from seeing the packet until the header is 333 * transmitted. This delay is used to communicate the crossbar 334 * forwarding latency to the neighbouring object (e.g. a cache) 335 * that actually makes the packet wait. As the delay is relative, 336 * a 32-bit unsigned should be sufficient. 337 */ 338 uint32_t headerDelay; 339 340 /** 341 * Keep track of the extra delay incurred by snooping upwards 342 * before sending a request down the memory system. This is used 343 * by the coherent crossbar to account for the additional request 344 * delay. 345 */ 346 uint32_t snoopDelay; 347 348 /** 349 * The extra pipelining delay from seeing the packet until the end of 350 * payload is transmitted by the component that provided it (if 351 * any). This includes the header delay. Similar to the header 352 * delay, this is used to make up for the fact that the 353 * crossbar does not make the packet wait. As the delay is 354 * relative, a 32-bit unsigned should be sufficient. 355 */ 356 uint32_t payloadDelay; 357 358 /** 359 * A virtual base opaque structure used to hold state associated 360 * with the packet (e.g., an MSHR), specific to a MemObject that 361 * sees the packet. A pointer to this state is returned in the 362 * packet's response so that the MemObject in question can quickly 363 * look up the state needed to process it. A specific subclass 364 * would be derived from this to carry state specific to a 365 * particular sending device. 366 * 367 * As multiple MemObjects may add their SenderState throughout the 368 * memory system, the SenderStates create a stack, where a 369 * MemObject can add a new Senderstate, as long as the 370 * predecessing SenderState is restored when the response comes 371 * back. For this reason, the predecessor should always be 372 * populated with the current SenderState of a packet before 373 * modifying the senderState field in the request packet. 374 */ 375 struct SenderState 376 { 377 SenderState* predecessor; 378 SenderState() : predecessor(NULL) {} 379 virtual ~SenderState() {} 380 }; 381 382 /** 383 * Object used to maintain state of a PrintReq. The senderState 384 * field of a PrintReq should always be of this type. 385 */ 386 class PrintReqState : public SenderState 387 { 388 private: 389 /** 390 * An entry in the label stack. 391 */ 392 struct LabelStackEntry 393 { 394 const std::string label; 395 std::string *prefix; 396 bool labelPrinted; 397 LabelStackEntry(const std::string &_label, std::string *_prefix); 398 }; 399 400 typedef std::list<LabelStackEntry> LabelStack; 401 LabelStack labelStack; 402 403 std::string *curPrefixPtr; 404 405 public: 406 std::ostream &os; 407 const int verbosity; 408 409 PrintReqState(std::ostream &os, int verbosity = 0); 410 ~PrintReqState(); 411 412 /** 413 * Returns the current line prefix. 414 */ 415 const std::string &curPrefix() { return *curPrefixPtr; } 416 417 /** 418 * Push a label onto the label stack, and prepend the given 419 * prefix string onto the current prefix. Labels will only be 420 * printed if an object within the label's scope is printed. 421 */ 422 void pushLabel(const std::string &lbl, 423 const std::string &prefix = " "); 424 425 /** 426 * Pop a label off the label stack. 427 */ 428 void popLabel(); 429 430 /** 431 * Print all of the pending unprinted labels on the 432 * stack. Called by printObj(), so normally not called by 433 * users unless bypassing printObj(). 434 */ 435 void printLabels(); 436 437 /** 438 * Print a Printable object to os, because it matched the 439 * address on a PrintReq. 440 */ 441 void printObj(Printable *obj); 442 }; 443 444 /** 445 * This packet's sender state. Devices should use dynamic_cast<> 446 * to cast to the state appropriate to the sender. The intent of 447 * this variable is to allow a device to attach extra information 448 * to a request. A response packet must return the sender state 449 * that was attached to the original request (even if a new packet 450 * is created). 451 */ 452 SenderState *senderState; 453 454 /** 455 * Push a new sender state to the packet and make the current 456 * sender state the predecessor of the new one. This should be 457 * prefered over direct manipulation of the senderState member 458 * variable. 459 * 460 * @param sender_state SenderState to push at the top of the stack 461 */ 462 void pushSenderState(SenderState *sender_state); 463 464 /** 465 * Pop the top of the state stack and return a pointer to it. This 466 * assumes the current sender state is not NULL. This should be 467 * preferred over direct manipulation of the senderState member 468 * variable. 469 * 470 * @return The current top of the stack 471 */ 472 SenderState *popSenderState(); 473 474 /** 475 * Go through the sender state stack and return the first instance 476 * that is of type T (as determined by a dynamic_cast). If there 477 * is no sender state of type T, NULL is returned. 478 * 479 * @return The topmost state of type T 480 */ 481 template <typename T> 482 T * findNextSenderState() const 483 { 484 T *t = NULL; 485 SenderState* sender_state = senderState; 486 while (t == NULL && sender_state != NULL) { 487 t = dynamic_cast<T*>(sender_state); 488 sender_state = sender_state->predecessor; 489 } 490 return t; 491 } 492 493 /// Return the string name of the cmd field (for debugging and 494 /// tracing). 495 const std::string &cmdString() const { return cmd.toString(); } 496 497 /// Return the index of this command. 498 inline int cmdToIndex() const { return cmd.toInt(); } 499 500 bool isRead() const { return cmd.isRead(); } 501 bool isWrite() const { return cmd.isWrite(); } 502 bool isUpgrade() const { return cmd.isUpgrade(); } 503 bool isRequest() const { return cmd.isRequest(); } 504 bool isResponse() const { return cmd.isResponse(); } 505 bool needsWritable() const 506 { 507 // we should never check if a response needsWritable, the 508 // request has this flag, and for a response we should rather 509 // look at the hasSharers flag (if not set, the response is to 510 // be considered writable) 511 assert(isRequest()); 512 return cmd.needsWritable(); 513 } 514 bool needsResponse() const { return cmd.needsResponse(); } 515 bool isInvalidate() const { return cmd.isInvalidate(); } 516 bool isEviction() const { return cmd.isEviction(); } 517 bool isWriteback() const { return cmd.isWriteback(); } 518 bool hasData() const { return cmd.hasData(); } 519 bool hasRespData() const 520 { 521 MemCmd resp_cmd = cmd.responseCommand(); 522 return resp_cmd.hasData(); 523 } 524 bool isLLSC() const { return cmd.isLLSC(); } 525 bool isError() const { return cmd.isError(); } 526 bool isPrint() const { return cmd.isPrint(); } 527 bool isFlush() const { return cmd.isFlush(); } 528 529 //@{ 530 /// Snoop flags 531 /** 532 * Set the cacheResponding flag. This is used by the caches to 533 * signal another cache that they are responding to a request. A 534 * cache will only respond to snoops if it has the line in either 535 * Modified or Owned state. Note that on snoop hits we always pass 536 * the line as Modified and never Owned. In the case of an Owned 537 * line we proceed to invalidate all other copies. 538 * 539 * On a cache fill (see Cache::handleFill), we check hasSharers 540 * first, ignoring the cacheResponding flag if hasSharers is set. 541 * A line is consequently allocated as: 542 * 543 * hasSharers cacheResponding state 544 * true false Shared 545 * true true Shared 546 * false false Exclusive 547 * false true Modified 548 */ 549 void setCacheResponding() 550 { 551 assert(isRequest()); 552 assert(!flags.isSet(CACHE_RESPONDING)); 553 flags.set(CACHE_RESPONDING); 554 } 555 bool cacheResponding() const { return flags.isSet(CACHE_RESPONDING); } 556 /** 557 * On fills, the hasSharers flag is used by the caches in 558 * combination with the cacheResponding flag, as clarified 559 * above. If the hasSharers flag is not set, the packet is passing 560 * writable. Thus, a response from a memory passes the line as 561 * writable by default. 562 * 563 * The hasSharers flag is also used by upstream caches to inform a 564 * downstream cache that they have the block (by calling 565 * setHasSharers on snoop request packets that hit in upstream 566 * cachs tags or MSHRs). If the snoop packet has sharers, a 567 * downstream cache is prevented from passing a dirty line upwards 568 * if it was not explicitly asked for a writable copy. See 569 * Cache::satisfyCpuSideRequest. 570 * 571 * The hasSharers flag is also used on writebacks, in 572 * combination with the WritbackClean or WritebackDirty commands, 573 * to allocate the block downstream either as: 574 * 575 * command hasSharers state 576 * WritebackDirty false Modified 577 * WritebackDirty true Owned 578 * WritebackClean false Exclusive 579 * WritebackClean true Shared 580 */ 581 void setHasSharers() { flags.set(HAS_SHARERS); } 582 bool hasSharers() const { return flags.isSet(HAS_SHARERS); } 583 //@} 584 585 /** 586 * The express snoop flag is used for two purposes. Firstly, it is 587 * used to bypass flow control for normal (non-snoop) requests 588 * going downstream in the memory system. In cases where a cache 589 * is responding to a snoop from another cache (it had a dirty 590 * line), but the line is not writable (and there are possibly 591 * other copies), the express snoop flag is set by the downstream 592 * cache to invalidate all other copies in zero time. Secondly, 593 * the express snoop flag is also set to be able to distinguish 594 * snoop packets that came from a downstream cache, rather than 595 * snoop packets from neighbouring caches. 596 */ 597 void setExpressSnoop() { flags.set(EXPRESS_SNOOP); } 598 bool isExpressSnoop() const { return flags.isSet(EXPRESS_SNOOP); } 599 600 /** 601 * On responding to a snoop request (which only happens for 602 * Modified or Owned lines), make sure that we can transform an 603 * Owned response to a Modified one. If this flag is not set, the 604 * responding cache had the line in the Owned state, and there are 605 * possibly other Shared copies in the memory system. A downstream 606 * cache helps in orchestrating the invalidation of these copies 607 * by sending out the appropriate express snoops. 608 */ 609 void setResponderHadWritable() 610 { 611 assert(cacheResponding()); 612 flags.set(RESPONDER_HAD_WRITABLE); 613 } 614 bool responderHadWritable() const 615 { return flags.isSet(RESPONDER_HAD_WRITABLE); } 616 617 void setSuppressFuncError() { flags.set(SUPPRESS_FUNC_ERROR); } 618 bool suppressFuncError() const { return flags.isSet(SUPPRESS_FUNC_ERROR); } 619 void setBlockCached() { flags.set(BLOCK_CACHED); } 620 bool isBlockCached() const { return flags.isSet(BLOCK_CACHED); } 621 void clearBlockCached() { flags.clear(BLOCK_CACHED); } 622 623 // Network error conditions... encapsulate them as methods since 624 // their encoding keeps changing (from result field to command 625 // field, etc.) 626 void 627 setBadAddress() 628 { 629 assert(isResponse()); 630 cmd = MemCmd::BadAddressError; 631 } 632 633 void copyError(Packet *pkt) { assert(pkt->isError()); cmd = pkt->cmd; } 634 635 Addr getAddr() const { assert(flags.isSet(VALID_ADDR)); return addr; } 636 /** 637 * Update the address of this packet mid-transaction. This is used 638 * by the address mapper to change an already set address to a new 639 * one based on the system configuration. It is intended to remap 640 * an existing address, so it asserts that the current address is 641 * valid. 642 */ 643 void setAddr(Addr _addr) { assert(flags.isSet(VALID_ADDR)); addr = _addr; } 644 645 unsigned getSize() const { assert(flags.isSet(VALID_SIZE)); return size; } 646 647 Addr getOffset(unsigned int blk_size) const 648 { 649 return getAddr() & Addr(blk_size - 1); 650 } 651 652 Addr getBlockAddr(unsigned int blk_size) const 653 { 654 return getAddr() & ~(Addr(blk_size - 1)); 655 } 656 657 bool isSecure() const 658 { 659 assert(flags.isSet(VALID_ADDR)); 660 return _isSecure; 661 } 662 663 /** 664 * Accessor function to atomic op. 665 */ 666 AtomicOpFunctor *getAtomicOp() const { return req->getAtomicOpFunctor(); } 667 bool isAtomicOp() const { return req->isAtomic(); } 668 669 /** 670 * It has been determined that the SC packet should successfully update 671 * memory. Therefore, convert this SC packet to a normal write. 672 */ 673 void 674 convertScToWrite() 675 { 676 assert(isLLSC()); 677 assert(isWrite()); 678 cmd = MemCmd::WriteReq; 679 } 680 681 /** 682 * When ruby is in use, Ruby will monitor the cache line and the 683 * phys memory should treat LL ops as normal reads. 684 */ 685 void 686 convertLlToRead() 687 { 688 assert(isLLSC()); 689 assert(isRead()); 690 cmd = MemCmd::ReadReq; 691 } 692 693 /** 694 * Constructor. Note that a Request object must be constructed 695 * first, but the Requests's physical address and size fields need 696 * not be valid. The command must be supplied. 697 */ 698 Packet(const RequestPtr _req, MemCmd _cmd) 699 : cmd(_cmd), req(_req), data(nullptr), addr(0), _isSecure(false), 700 size(0), headerDelay(0), snoopDelay(0), payloadDelay(0), 701 senderState(NULL) 702 { 703 if (req->hasPaddr()) { 704 addr = req->getPaddr(); 705 flags.set(VALID_ADDR); 706 _isSecure = req->isSecure(); 707 } 708 if (req->hasSize()) { 709 size = req->getSize(); 710 flags.set(VALID_SIZE); 711 } 712 } 713 714 /** 715 * Alternate constructor if you are trying to create a packet with 716 * a request that is for a whole block, not the address from the 717 * req. this allows for overriding the size/addr of the req. 718 */ 719 Packet(const RequestPtr _req, MemCmd _cmd, int _blkSize) 720 : cmd(_cmd), req(_req), data(nullptr), addr(0), _isSecure(false), 721 headerDelay(0), snoopDelay(0), payloadDelay(0), 722 senderState(NULL) 723 { 724 if (req->hasPaddr()) { 725 addr = req->getPaddr() & ~(_blkSize - 1); 726 flags.set(VALID_ADDR); 727 _isSecure = req->isSecure(); 728 } 729 size = _blkSize; 730 flags.set(VALID_SIZE); 731 } 732 733 /** 734 * Alternate constructor for copying a packet. Copy all fields 735 * *except* if the original packet's data was dynamic, don't copy 736 * that, as we can't guarantee that the new packet's lifetime is 737 * less than that of the original packet. In this case the new 738 * packet should allocate its own data. 739 */ 740 Packet(const PacketPtr pkt, bool clear_flags, bool alloc_data) 741 : cmd(pkt->cmd), req(pkt->req), 742 data(nullptr), 743 addr(pkt->addr), _isSecure(pkt->_isSecure), size(pkt->size), 744 bytesValid(pkt->bytesValid), 745 headerDelay(pkt->headerDelay), 746 snoopDelay(0), 747 payloadDelay(pkt->payloadDelay), 748 senderState(pkt->senderState) 749 { 750 if (!clear_flags) 751 flags.set(pkt->flags & COPY_FLAGS); 752 753 flags.set(pkt->flags & (VALID_ADDR|VALID_SIZE)); 754 755 // should we allocate space for data, or not, the express 756 // snoops do not need to carry any data as they only serve to 757 // co-ordinate state changes 758 if (alloc_data) { 759 // even if asked to allocate data, if the original packet 760 // holds static data, then the sender will not be doing 761 // any memcpy on receiving the response, thus we simply 762 // carry the pointer forward 763 if (pkt->flags.isSet(STATIC_DATA)) { 764 data = pkt->data; 765 flags.set(STATIC_DATA); 766 } else { 767 allocate(); 768 } 769 } 770 } 771 772 /** 773 * Generate the appropriate read MemCmd based on the Request flags. 774 */ 775 static MemCmd 776 makeReadCmd(const RequestPtr req) 777 { 778 if (req->isLLSC()) 779 return MemCmd::LoadLockedReq; 780 else if (req->isPrefetch()) 781 return MemCmd::SoftPFReq; 782 else 783 return MemCmd::ReadReq; 784 } 785 786 /** 787 * Generate the appropriate write MemCmd based on the Request flags. 788 */ 789 static MemCmd 790 makeWriteCmd(const RequestPtr req) 791 { 792 if (req->isLLSC()) 793 return MemCmd::StoreCondReq; 794 else if (req->isSwap()) 795 return MemCmd::SwapReq; 796 else 797 return MemCmd::WriteReq; 798 } 799 800 /** 801 * Constructor-like methods that return Packets based on Request objects. 802 * Fine-tune the MemCmd type if it's not a vanilla read or write. 803 */ 804 static PacketPtr 805 createRead(const RequestPtr req) 806 { 807 return new Packet(req, makeReadCmd(req)); 808 } 809 810 static PacketPtr 811 createWrite(const RequestPtr req) 812 { 813 return new Packet(req, makeWriteCmd(req)); 814 } 815 816 /** 817 * clean up packet variables 818 */ 819 ~Packet() 820 { 821 // Delete the request object if this is a request packet which 822 // does not need a response, because the requester will not get 823 // a chance. If the request packet needs a response then the 824 // request will be deleted on receipt of the response 825 // packet. We also make sure to never delete the request for 826 // express snoops, even for cases when responses are not 827 // needed (CleanEvict and Writeback), since the snoop packet 828 // re-uses the same request. 829 if (req && isRequest() && !needsResponse() && 830 !isExpressSnoop()) { 831 delete req; 832 } 833 deleteData(); 834 } 835 836 /** 837 * Take a request packet and modify it in place to be suitable for 838 * returning as a response to that request. 839 */ 840 void 841 makeResponse() 842 { 843 assert(needsResponse()); 844 assert(isRequest()); 845 cmd = cmd.responseCommand(); 846 847 // responses are never express, even if the snoop that 848 // triggered them was 849 flags.clear(EXPRESS_SNOOP); 850 } 851 852 void 853 makeAtomicResponse() 854 { 855 makeResponse(); 856 } 857 858 void 859 makeTimingResponse() 860 { 861 makeResponse(); 862 } 863 864 void 865 setFunctionalResponseStatus(bool success) 866 { 867 if (!success) { 868 if (isWrite()) { 869 cmd = MemCmd::FunctionalWriteError; 870 } else { 871 cmd = MemCmd::FunctionalReadError; 872 } 873 } 874 } 875 876 void 877 setSize(unsigned size) 878 { 879 assert(!flags.isSet(VALID_SIZE)); 880 881 this->size = size; 882 flags.set(VALID_SIZE); 883 } 884 885 886 public: 887 /** 888 * @{ 889 * @name Data accessor mehtods 890 */ 891 892 /** 893 * Set the data pointer to the following value that should not be 894 * freed. Static data allows us to do a single memcpy even if 895 * multiple packets are required to get from source to destination 896 * and back. In essence the pointer is set calling dataStatic on 897 * the original packet, and whenever this packet is copied and 898 * forwarded the same pointer is passed on. When a packet 899 * eventually reaches the destination holding the data, it is 900 * copied once into the location originally set. On the way back 901 * to the source, no copies are necessary. 902 */ 903 template <typename T> 904 void 905 dataStatic(T *p) 906 { 907 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 908 data = (PacketDataPtr)p; 909 flags.set(STATIC_DATA); 910 } 911 912 /** 913 * Set the data pointer to the following value that should not be 914 * freed. This version of the function allows the pointer passed 915 * to us to be const. To avoid issues down the line we cast the 916 * constness away, the alternative would be to keep both a const 917 * and non-const data pointer and cleverly choose between 918 * them. Note that this is only allowed for static data. 919 */ 920 template <typename T> 921 void 922 dataStaticConst(const T *p) 923 { 924 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 925 data = const_cast<PacketDataPtr>(p); 926 flags.set(STATIC_DATA); 927 } 928 929 /** 930 * Set the data pointer to a value that should have delete [] 931 * called on it. Dynamic data is local to this packet, and as the 932 * packet travels from source to destination, forwarded packets 933 * will allocate their own data. When a packet reaches the final 934 * destination it will populate the dynamic data of that specific 935 * packet, and on the way back towards the source, memcpy will be 936 * invoked in every step where a new packet was created e.g. in 937 * the caches. Ultimately when the response reaches the source a 938 * final memcpy is needed to extract the data from the packet 939 * before it is deallocated. 940 */ 941 template <typename T> 942 void 943 dataDynamic(T *p) 944 { 945 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 946 data = (PacketDataPtr)p; 947 flags.set(DYNAMIC_DATA); 948 } 949 950 /** 951 * get a pointer to the data ptr. 952 */ 953 template <typename T> 954 T* 955 getPtr() 956 { 957 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA)); 958 return (T*)data; 959 } 960 961 template <typename T> 962 const T* 963 getConstPtr() const 964 { 965 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA)); 966 return (const T*)data; 967 } 968 969 /** 970 * Get the data in the packet byte swapped from big endian to 971 * host endian. 972 */ 973 template <typename T> 974 T getBE() const; 975 976 /** 977 * Get the data in the packet byte swapped from little endian to 978 * host endian. 979 */ 980 template <typename T> 981 T getLE() const; 982 983 /** 984 * Get the data in the packet byte swapped from the specified 985 * endianness. 986 */ 987 template <typename T> 988 T get(ByteOrder endian) const; 989 990 /** 991 * Get the data in the packet byte swapped from guest to host 992 * endian. 993 */ 994 template <typename T> 995 T get() const; 996 997 /** Set the value in the data pointer to v as big endian. */ 998 template <typename T> 999 void setBE(T v); 1000 1001 /** Set the value in the data pointer to v as little endian. */ 1002 template <typename T> 1003 void setLE(T v); 1004 1005 /** 1006 * Set the value in the data pointer to v using the specified 1007 * endianness. 1008 */ 1009 template <typename T> 1010 void set(T v, ByteOrder endian); 1011 1012 /** Set the value in the data pointer to v as guest endian. */ 1013 template <typename T> 1014 void set(T v); 1015 1016 /** 1017 * Copy data into the packet from the provided pointer. 1018 */ 1019 void 1020 setData(const uint8_t *p) 1021 { 1022 // we should never be copying data onto itself, which means we 1023 // must idenfity packets with static data, as they carry the 1024 // same pointer from source to destination and back 1025 assert(p != getPtr<uint8_t>() || flags.isSet(STATIC_DATA)); 1026 1027 if (p != getPtr<uint8_t>()) 1028 // for packet with allocated dynamic data, we copy data from 1029 // one to the other, e.g. a forwarded response to a response 1030 std::memcpy(getPtr<uint8_t>(), p, getSize()); 1031 } 1032 1033 /** 1034 * Copy data into the packet from the provided block pointer, 1035 * which is aligned to the given block size. 1036 */ 1037 void 1038 setDataFromBlock(const uint8_t *blk_data, int blkSize) 1039 { 1040 setData(blk_data + getOffset(blkSize)); 1041 } 1042 1043 /** 1044 * Copy data from the packet to the provided block pointer, which 1045 * is aligned to the given block size. 1046 */ 1047 void 1048 writeData(uint8_t *p) const 1049 { 1050 std::memcpy(p, getConstPtr<uint8_t>(), getSize()); 1051 } 1052 1053 /** 1054 * Copy data from the packet to the memory at the provided pointer. 1055 */ 1056 void 1057 writeDataToBlock(uint8_t *blk_data, int blkSize) const 1058 { 1059 writeData(blk_data + getOffset(blkSize)); 1060 } 1061 1062 /** 1063 * delete the data pointed to in the data pointer. Ok to call to 1064 * matter how data was allocted. 1065 */ 1066 void 1067 deleteData() 1068 { 1069 if (flags.isSet(DYNAMIC_DATA)) 1070 delete [] data; 1071 1072 flags.clear(STATIC_DATA|DYNAMIC_DATA); 1073 data = NULL; 1074 } 1075 1076 /** Allocate memory for the packet. */ 1077 void 1078 allocate() 1079 { 1080 // if either this command or the response command has a data 1081 // payload, actually allocate space 1082 if (hasData() || hasRespData()) { 1083 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 1084 flags.set(DYNAMIC_DATA); 1085 data = new uint8_t[getSize()]; 1086 } 1087 } 1088 1089 /** @} */ 1090 1091 private: // Private data accessor methods 1092 /** Get the data in the packet without byte swapping. */ 1093 template <typename T> 1094 T getRaw() const; 1095 1096 /** Set the value in the data pointer to v without byte swapping. */ 1097 template <typename T> 1098 void setRaw(T v); 1099 1100 public: 1101 /** 1102 * Check a functional request against a memory value stored in 1103 * another packet (i.e. an in-transit request or 1104 * response). Returns true if the current packet is a read, and 1105 * the other packet provides the data, which is then copied to the 1106 * current packet. If the current packet is a write, and the other 1107 * packet intersects this one, then we update the data 1108 * accordingly. 1109 */ 1110 bool 1111 checkFunctional(PacketPtr other) 1112 { 1113 // all packets that are carrying a payload should have a valid 1114 // data pointer 1115 return checkFunctional(other, other->getAddr(), other->isSecure(), 1116 other->getSize(), 1117 other->hasData() ? 1118 other->getPtr<uint8_t>() : NULL); 1119 } 1120 1121 /** 1122 * Does the request need to check for cached copies of the same block 1123 * in the memory hierarchy above. 1124 **/ 1125 bool 1126 mustCheckAbove() const 1127 { 1128 return cmd == MemCmd::HardPFReq || isEviction(); 1129 } 1130 1131 /** 1132 * Is this packet a clean eviction, including both actual clean 1133 * evict packets, but also clean writebacks. 1134 */ 1135 bool 1136 isCleanEviction() const 1137 { 1138 return cmd == MemCmd::CleanEvict || cmd == MemCmd::WritebackClean; 1139 } 1140 1141 /** 1142 * Check a functional request against a memory value represented 1143 * by a base/size pair and an associated data array. If the 1144 * current packet is a read, it may be satisfied by the memory 1145 * value. If the current packet is a write, it may update the 1146 * memory value. 1147 */ 1148 bool 1149 checkFunctional(Printable *obj, Addr base, bool is_secure, int size, 1150 uint8_t *_data); 1151 1152 /** 1153 * Push label for PrintReq (safe to call unconditionally). 1154 */ 1155 void 1156 pushLabel(const std::string &lbl) 1157 { 1158 if (isPrint()) 1159 safe_cast<PrintReqState*>(senderState)->pushLabel(lbl); 1160 } 1161 1162 /** 1163 * Pop label for PrintReq (safe to call unconditionally). 1164 */ 1165 void 1166 popLabel() 1167 { 1168 if (isPrint()) 1169 safe_cast<PrintReqState*>(senderState)->popLabel(); 1170 } 1171 1172 void print(std::ostream &o, int verbosity = 0, 1173 const std::string &prefix = "") const; 1174 1175 /** 1176 * A no-args wrapper of print(std::ostream...) 1177 * meant to be invoked from DPRINTFs 1178 * avoiding string overheads in fast mode 1179 * @return string with the request's type and start<->end addresses 1180 */ 1181 std::string print() const; 1182}; 1183 1184#endif //__MEM_PACKET_HH 1185