packet.hh revision 10660:87f7b5a07584
1/* 2 * Copyright (c) 2012-2014 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 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 Writeback, 90 SoftPFReq, 91 HardPFReq, 92 SoftPFResp, 93 HardPFResp, 94 WriteInvalidateReq, 95 WriteInvalidateResp, 96 UpgradeReq, 97 SCUpgradeReq, // Special "weak" upgrade for StoreCond 98 UpgradeResp, 99 SCUpgradeFailReq, // Failed SCUpgradeReq in MSHR (never sent) 100 UpgradeFailResp, // Valid for SCUpgradeReq only 101 ReadExReq, 102 ReadExResp, 103 LoadLockedReq, 104 StoreCondReq, 105 StoreCondFailReq, // Failed StoreCondReq in MSHR (never sent) 106 StoreCondResp, 107 SwapReq, 108 SwapResp, 109 MessageReq, 110 MessageResp, 111 // Error responses 112 // @TODO these should be classified as responses rather than 113 // requests; coding them as requests initially for backwards 114 // compatibility 115 InvalidDestError, // packet dest field invalid 116 BadAddressError, // memory address invalid 117 FunctionalReadError, // unable to fulfill functional read 118 FunctionalWriteError, // unable to fulfill functional write 119 // Fake simulator-only commands 120 PrintReq, // Print state matching address 121 FlushReq, //request for a cache flush 122 InvalidationReq, // request for address to be invalidated from lsq 123 NUM_MEM_CMDS 124 }; 125 126 private: 127 /** 128 * List of command attributes. 129 */ 130 enum Attribute 131 { 132 IsRead, //!< Data flows from responder to requester 133 IsWrite, //!< Data flows from requester to responder 134 IsUpgrade, 135 IsInvalidate, 136 NeedsExclusive, //!< Requires exclusive copy to complete in-cache 137 IsRequest, //!< Issued by requester 138 IsResponse, //!< Issue by responder 139 NeedsResponse, //!< Requester needs response from target 140 IsSWPrefetch, 141 IsHWPrefetch, 142 IsLlsc, //!< Alpha/MIPS LL or SC access 143 HasData, //!< There is an associated payload 144 IsError, //!< Error response 145 IsPrint, //!< Print state matching address (for debugging) 146 IsFlush, //!< Flush the address from caches 147 NUM_COMMAND_ATTRIBUTES 148 }; 149 150 /** 151 * Structure that defines attributes and other data associated 152 * with a Command. 153 */ 154 struct CommandInfo 155 { 156 /// Set of attribute flags. 157 const std::bitset<NUM_COMMAND_ATTRIBUTES> attributes; 158 /// Corresponding response for requests; InvalidCmd if no 159 /// response is applicable. 160 const Command response; 161 /// String representation (for printing) 162 const std::string str; 163 }; 164 165 /// Array to map Command enum to associated info. 166 static const CommandInfo commandInfo[]; 167 168 private: 169 170 Command cmd; 171 172 bool 173 testCmdAttrib(MemCmd::Attribute attrib) const 174 { 175 return commandInfo[cmd].attributes[attrib] != 0; 176 } 177 178 public: 179 180 bool isRead() const { return testCmdAttrib(IsRead); } 181 bool isWrite() const { return testCmdAttrib(IsWrite); } 182 bool isUpgrade() const { return testCmdAttrib(IsUpgrade); } 183 bool isRequest() const { return testCmdAttrib(IsRequest); } 184 bool isResponse() const { return testCmdAttrib(IsResponse); } 185 bool needsExclusive() const { return testCmdAttrib(NeedsExclusive); } 186 bool needsResponse() const { return testCmdAttrib(NeedsResponse); } 187 bool isInvalidate() const { return testCmdAttrib(IsInvalidate); } 188 bool isWriteInvalidate() const { return testCmdAttrib(IsWrite) && 189 testCmdAttrib(IsInvalidate); } 190 191 /** 192 * Check if this particular packet type carries payload data. Note 193 * that this does not reflect if the data pointer of the packet is 194 * valid or not. 195 */ 196 bool hasData() const { return testCmdAttrib(HasData); } 197 bool isLLSC() const { return testCmdAttrib(IsLlsc); } 198 bool isSWPrefetch() const { return testCmdAttrib(IsSWPrefetch); } 199 bool isHWPrefetch() const { return testCmdAttrib(IsHWPrefetch); } 200 bool isPrefetch() const { return testCmdAttrib(IsSWPrefetch) || 201 testCmdAttrib(IsHWPrefetch); } 202 bool isError() const { return testCmdAttrib(IsError); } 203 bool isPrint() const { return testCmdAttrib(IsPrint); } 204 bool isFlush() const { return testCmdAttrib(IsFlush); } 205 206 const Command 207 responseCommand() const 208 { 209 return commandInfo[cmd].response; 210 } 211 212 /// Return the string to a cmd given by idx. 213 const std::string &toString() const { return commandInfo[cmd].str; } 214 int toInt() const { return (int)cmd; } 215 216 MemCmd(Command _cmd) : cmd(_cmd) { } 217 MemCmd(int _cmd) : cmd((Command)_cmd) { } 218 MemCmd() : cmd(InvalidCmd) { } 219 220 bool operator==(MemCmd c2) const { return (cmd == c2.cmd); } 221 bool operator!=(MemCmd c2) const { return (cmd != c2.cmd); } 222}; 223 224/** 225 * A Packet is used to encapsulate a transfer between two objects in 226 * the memory system (e.g., the L1 and L2 cache). (In contrast, a 227 * single Request travels all the way from the requester to the 228 * ultimate destination and back, possibly being conveyed by several 229 * different Packets along the way.) 230 */ 231class Packet : public Printable 232{ 233 public: 234 typedef uint32_t FlagsType; 235 typedef ::Flags<FlagsType> Flags; 236 237 private: 238 static const FlagsType PUBLIC_FLAGS = 0x00000000; 239 static const FlagsType PRIVATE_FLAGS = 0x00007F0F; 240 static const FlagsType COPY_FLAGS = 0x0000000F; 241 242 static const FlagsType SHARED = 0x00000001; 243 // Special control flags 244 /// Special timing-mode atomic snoop for multi-level coherence. 245 static const FlagsType EXPRESS_SNOOP = 0x00000002; 246 /// Does supplier have exclusive copy? 247 /// Useful for multi-level coherence. 248 static const FlagsType SUPPLY_EXCLUSIVE = 0x00000004; 249 // Snoop response flags 250 static const FlagsType MEM_INHIBIT = 0x00000008; 251 /// Are the 'addr' and 'size' fields valid? 252 static const FlagsType VALID_ADDR = 0x00000100; 253 static const FlagsType VALID_SIZE = 0x00000200; 254 /// Is the data pointer set to a value that shouldn't be freed 255 /// when the packet is destroyed? 256 static const FlagsType STATIC_DATA = 0x00001000; 257 /// The data pointer points to a value that should be freed when 258 /// the packet is destroyed. The pointer is assumed to be pointing 259 /// to an array, and delete [] is consequently called 260 static const FlagsType DYNAMIC_DATA = 0x00002000; 261 /// suppress the error if this packet encounters a functional 262 /// access failure. 263 static const FlagsType SUPPRESS_FUNC_ERROR = 0x00008000; 264 // Signal prefetch squash through express snoop flag 265 static const FlagsType PREFETCH_SNOOP_SQUASH = 0x00010000; 266 267 Flags flags; 268 269 public: 270 typedef MemCmd::Command Command; 271 272 /// The command field of the packet. 273 MemCmd cmd; 274 275 /// A pointer to the original request. 276 const RequestPtr req; 277 278 private: 279 /** 280 * A pointer to the data being transfered. It can be differnt 281 * sizes at each level of the heirarchy so it belongs in the 282 * packet, not request. This may or may not be populated when a 283 * responder recieves the packet. If not populated it memory should 284 * be allocated. 285 */ 286 PacketDataPtr data; 287 288 /// The address of the request. This address could be virtual or 289 /// physical, depending on the system configuration. 290 Addr addr; 291 292 /// True if the request targets the secure memory space. 293 bool _isSecure; 294 295 /// The size of the request or transfer. 296 unsigned size; 297 298 /** 299 * The original value of the command field. Only valid when the 300 * current command field is an error condition; in that case, the 301 * previous contents of the command field are copied here. This 302 * field is *not* set on non-error responses. 303 */ 304 MemCmd origCmd; 305 306 /** 307 * These values specify the range of bytes found that satisfy a 308 * functional read. 309 */ 310 uint16_t bytesValidStart; 311 uint16_t bytesValidEnd; 312 313 public: 314 315 /** 316 * The extra delay from seeing the packet until the first word is 317 * transmitted. This delay is used to communicate the crossbar 318 * forwarding latency to the neighbouring object (e.g. a cache) 319 * that actually makes the packet wait. As the delay is relative, 320 * a 32-bit unsigned should be sufficient. 321 */ 322 uint32_t firstWordDelay; 323 324 /** 325 * The extra pipelining delay from seeing the packet until the 326 * last word is transmitted by the component that provided it (if 327 * any). This includes the first word delay. Similar to the first 328 * word delay, this is used to make up for the fact that the 329 * crossbar does not make the packet wait. As the delay is 330 * relative, a 32-bit unsigned should be sufficient. 331 */ 332 uint32_t lastWordDelay; 333 334 /** 335 * A virtual base opaque structure used to hold state associated 336 * with the packet (e.g., an MSHR), specific to a MemObject that 337 * sees the packet. A pointer to this state is returned in the 338 * packet's response so that the MemObject in question can quickly 339 * look up the state needed to process it. A specific subclass 340 * would be derived from this to carry state specific to a 341 * particular sending device. 342 * 343 * As multiple MemObjects may add their SenderState throughout the 344 * memory system, the SenderStates create a stack, where a 345 * MemObject can add a new Senderstate, as long as the 346 * predecessing SenderState is restored when the response comes 347 * back. For this reason, the predecessor should always be 348 * populated with the current SenderState of a packet before 349 * modifying the senderState field in the request packet. 350 */ 351 struct SenderState 352 { 353 SenderState* predecessor; 354 SenderState() : predecessor(NULL) {} 355 virtual ~SenderState() {} 356 }; 357 358 /** 359 * Object used to maintain state of a PrintReq. The senderState 360 * field of a PrintReq should always be of this type. 361 */ 362 class PrintReqState : public SenderState 363 { 364 private: 365 /** 366 * An entry in the label stack. 367 */ 368 struct LabelStackEntry 369 { 370 const std::string label; 371 std::string *prefix; 372 bool labelPrinted; 373 LabelStackEntry(const std::string &_label, std::string *_prefix); 374 }; 375 376 typedef std::list<LabelStackEntry> LabelStack; 377 LabelStack labelStack; 378 379 std::string *curPrefixPtr; 380 381 public: 382 std::ostream &os; 383 const int verbosity; 384 385 PrintReqState(std::ostream &os, int verbosity = 0); 386 ~PrintReqState(); 387 388 /** 389 * Returns the current line prefix. 390 */ 391 const std::string &curPrefix() { return *curPrefixPtr; } 392 393 /** 394 * Push a label onto the label stack, and prepend the given 395 * prefix string onto the current prefix. Labels will only be 396 * printed if an object within the label's scope is printed. 397 */ 398 void pushLabel(const std::string &lbl, 399 const std::string &prefix = " "); 400 401 /** 402 * Pop a label off the label stack. 403 */ 404 void popLabel(); 405 406 /** 407 * Print all of the pending unprinted labels on the 408 * stack. Called by printObj(), so normally not called by 409 * users unless bypassing printObj(). 410 */ 411 void printLabels(); 412 413 /** 414 * Print a Printable object to os, because it matched the 415 * address on a PrintReq. 416 */ 417 void printObj(Printable *obj); 418 }; 419 420 /** 421 * This packet's sender state. Devices should use dynamic_cast<> 422 * to cast to the state appropriate to the sender. The intent of 423 * this variable is to allow a device to attach extra information 424 * to a request. A response packet must return the sender state 425 * that was attached to the original request (even if a new packet 426 * is created). 427 */ 428 SenderState *senderState; 429 430 /** 431 * Push a new sender state to the packet and make the current 432 * sender state the predecessor of the new one. This should be 433 * prefered over direct manipulation of the senderState member 434 * variable. 435 * 436 * @param sender_state SenderState to push at the top of the stack 437 */ 438 void pushSenderState(SenderState *sender_state); 439 440 /** 441 * Pop the top of the state stack and return a pointer to it. This 442 * assumes the current sender state is not NULL. This should be 443 * preferred over direct manipulation of the senderState member 444 * variable. 445 * 446 * @return The current top of the stack 447 */ 448 SenderState *popSenderState(); 449 450 /** 451 * Go through the sender state stack and return the first instance 452 * that is of type T (as determined by a dynamic_cast). If there 453 * is no sender state of type T, NULL is returned. 454 * 455 * @return The topmost state of type T 456 */ 457 template <typename T> 458 T * findNextSenderState() const 459 { 460 T *t = NULL; 461 SenderState* sender_state = senderState; 462 while (t == NULL && sender_state != NULL) { 463 t = dynamic_cast<T*>(sender_state); 464 sender_state = sender_state->predecessor; 465 } 466 return t; 467 } 468 469 /// Return the string name of the cmd field (for debugging and 470 /// tracing). 471 const std::string &cmdString() const { return cmd.toString(); } 472 473 /// Return the index of this command. 474 inline int cmdToIndex() const { return cmd.toInt(); } 475 476 bool isRead() const { return cmd.isRead(); } 477 bool isWrite() const { return cmd.isWrite(); } 478 bool isUpgrade() const { return cmd.isUpgrade(); } 479 bool isRequest() const { return cmd.isRequest(); } 480 bool isResponse() const { return cmd.isResponse(); } 481 bool needsExclusive() const { return cmd.needsExclusive(); } 482 bool needsResponse() const { return cmd.needsResponse(); } 483 bool isInvalidate() const { return cmd.isInvalidate(); } 484 bool isWriteInvalidate() const { return cmd.isWriteInvalidate(); } 485 bool hasData() const { return cmd.hasData(); } 486 bool isLLSC() const { return cmd.isLLSC(); } 487 bool isError() const { return cmd.isError(); } 488 bool isPrint() const { return cmd.isPrint(); } 489 bool isFlush() const { return cmd.isFlush(); } 490 491 // Snoop flags 492 void assertMemInhibit() 493 { 494 assert(isRequest()); 495 assert(!flags.isSet(MEM_INHIBIT)); 496 flags.set(MEM_INHIBIT); 497 } 498 bool memInhibitAsserted() const { return flags.isSet(MEM_INHIBIT); } 499 void assertShared() { flags.set(SHARED); } 500 bool sharedAsserted() const { return flags.isSet(SHARED); } 501 502 // Special control flags 503 void setExpressSnoop() { flags.set(EXPRESS_SNOOP); } 504 bool isExpressSnoop() const { return flags.isSet(EXPRESS_SNOOP); } 505 void setSupplyExclusive() { flags.set(SUPPLY_EXCLUSIVE); } 506 void clearSupplyExclusive() { flags.clear(SUPPLY_EXCLUSIVE); } 507 bool isSupplyExclusive() const { return flags.isSet(SUPPLY_EXCLUSIVE); } 508 void setSuppressFuncError() { flags.set(SUPPRESS_FUNC_ERROR); } 509 bool suppressFuncError() const { return flags.isSet(SUPPRESS_FUNC_ERROR); } 510 void setPrefetchSquashed() { flags.set(PREFETCH_SNOOP_SQUASH); } 511 bool prefetchSquashed() const { return flags.isSet(PREFETCH_SNOOP_SQUASH); } 512 513 // Network error conditions... encapsulate them as methods since 514 // their encoding keeps changing (from result field to command 515 // field, etc.) 516 void 517 setBadAddress() 518 { 519 assert(isResponse()); 520 cmd = MemCmd::BadAddressError; 521 } 522 523 bool hadBadAddress() const { return cmd == MemCmd::BadAddressError; } 524 void copyError(Packet *pkt) { assert(pkt->isError()); cmd = pkt->cmd; } 525 526 Addr getAddr() const { assert(flags.isSet(VALID_ADDR)); return addr; } 527 /** 528 * Update the address of this packet mid-transaction. This is used 529 * by the address mapper to change an already set address to a new 530 * one based on the system configuration. It is intended to remap 531 * an existing address, so it asserts that the current address is 532 * valid. 533 */ 534 void setAddr(Addr _addr) { assert(flags.isSet(VALID_ADDR)); addr = _addr; } 535 536 unsigned getSize() const { assert(flags.isSet(VALID_SIZE)); return size; } 537 Addr getOffset(int blkSize) const { return getAddr() & (Addr)(blkSize - 1); } 538 539 bool isSecure() const 540 { 541 assert(flags.isSet(VALID_ADDR)); 542 return _isSecure; 543 } 544 545 /** 546 * It has been determined that the SC packet should successfully update 547 * memory. Therefore, convert this SC packet to a normal write. 548 */ 549 void 550 convertScToWrite() 551 { 552 assert(isLLSC()); 553 assert(isWrite()); 554 cmd = MemCmd::WriteReq; 555 } 556 557 /** 558 * When ruby is in use, Ruby will monitor the cache line and thus M5 559 * phys memory should treat LL ops as normal reads. 560 */ 561 void 562 convertLlToRead() 563 { 564 assert(isLLSC()); 565 assert(isRead()); 566 cmd = MemCmd::ReadReq; 567 } 568 569 /** 570 * Constructor. Note that a Request object must be constructed 571 * first, but the Requests's physical address and size fields need 572 * not be valid. The command must be supplied. 573 */ 574 Packet(const RequestPtr _req, MemCmd _cmd) 575 : cmd(_cmd), req(_req), data(nullptr), addr(0), _isSecure(false), 576 size(0), bytesValidStart(0), bytesValidEnd(0), 577 firstWordDelay(0), lastWordDelay(0), 578 senderState(NULL) 579 { 580 if (req->hasPaddr()) { 581 addr = req->getPaddr(); 582 flags.set(VALID_ADDR); 583 _isSecure = req->isSecure(); 584 } 585 if (req->hasSize()) { 586 size = req->getSize(); 587 flags.set(VALID_SIZE); 588 } 589 } 590 591 /** 592 * Alternate constructor if you are trying to create a packet with 593 * a request that is for a whole block, not the address from the 594 * req. this allows for overriding the size/addr of the req. 595 */ 596 Packet(const RequestPtr _req, MemCmd _cmd, int _blkSize) 597 : cmd(_cmd), req(_req), data(nullptr), addr(0), _isSecure(false), 598 bytesValidStart(0), bytesValidEnd(0), 599 firstWordDelay(0), lastWordDelay(0), 600 senderState(NULL) 601 { 602 if (req->hasPaddr()) { 603 addr = req->getPaddr() & ~(_blkSize - 1); 604 flags.set(VALID_ADDR); 605 _isSecure = req->isSecure(); 606 } 607 size = _blkSize; 608 flags.set(VALID_SIZE); 609 } 610 611 /** 612 * Alternate constructor for copying a packet. Copy all fields 613 * *except* if the original packet's data was dynamic, don't copy 614 * that, as we can't guarantee that the new packet's lifetime is 615 * less than that of the original packet. In this case the new 616 * packet should allocate its own data. 617 */ 618 Packet(PacketPtr pkt, bool clear_flags, bool alloc_data) 619 : cmd(pkt->cmd), req(pkt->req), 620 data(nullptr), 621 addr(pkt->addr), _isSecure(pkt->_isSecure), size(pkt->size), 622 bytesValidStart(pkt->bytesValidStart), 623 bytesValidEnd(pkt->bytesValidEnd), 624 firstWordDelay(pkt->firstWordDelay), 625 lastWordDelay(pkt->lastWordDelay), 626 senderState(pkt->senderState) 627 { 628 if (!clear_flags) 629 flags.set(pkt->flags & COPY_FLAGS); 630 631 flags.set(pkt->flags & (VALID_ADDR|VALID_SIZE)); 632 633 // should we allocate space for data, or not, the express 634 // snoops do not need to carry any data as they only serve to 635 // co-ordinate state changes 636 if (alloc_data) { 637 // even if asked to allocate data, if the original packet 638 // holds static data, then the sender will not be doing 639 // any memcpy on receiving the response, thus we simply 640 // carry the pointer forward 641 if (pkt->flags.isSet(STATIC_DATA)) { 642 data = pkt->data; 643 flags.set(STATIC_DATA); 644 } else { 645 allocate(); 646 } 647 } 648 } 649 650 /** 651 * Change the packet type based on request type. 652 */ 653 void 654 refineCommand() 655 { 656 if (cmd == MemCmd::ReadReq) { 657 if (req->isLLSC()) { 658 cmd = MemCmd::LoadLockedReq; 659 } else if (req->isPrefetch()) { 660 cmd = MemCmd::SoftPFReq; 661 } 662 } else if (cmd == MemCmd::WriteReq) { 663 if (req->isLLSC()) { 664 cmd = MemCmd::StoreCondReq; 665 } else if (req->isSwap()) { 666 cmd = MemCmd::SwapReq; 667 } 668 } 669 } 670 671 /** 672 * Constructor-like methods that return Packets based on Request objects. 673 * Will call refineCommand() to fine-tune the Packet type if it's not a 674 * vanilla read or write. 675 */ 676 static PacketPtr 677 createRead(const RequestPtr req) 678 { 679 PacketPtr pkt = new Packet(req, MemCmd::ReadReq); 680 pkt->refineCommand(); 681 return pkt; 682 } 683 684 static PacketPtr 685 createWrite(const RequestPtr req) 686 { 687 PacketPtr pkt = new Packet(req, MemCmd::WriteReq); 688 pkt->refineCommand(); 689 return pkt; 690 } 691 692 /** 693 * clean up packet variables 694 */ 695 ~Packet() 696 { 697 // If this is a request packet for which there's no response, 698 // delete the request object here, since the requester will 699 // never get the chance. 700 if (req && isRequest() && !needsResponse()) 701 delete req; 702 deleteData(); 703 } 704 705 /** 706 * Take a request packet and modify it in place to be suitable for 707 * returning as a response to that request. 708 */ 709 void 710 makeResponse() 711 { 712 assert(needsResponse()); 713 assert(isRequest()); 714 origCmd = cmd; 715 cmd = cmd.responseCommand(); 716 717 // responses are never express, even if the snoop that 718 // triggered them was 719 flags.clear(EXPRESS_SNOOP); 720 } 721 722 void 723 makeAtomicResponse() 724 { 725 makeResponse(); 726 } 727 728 void 729 makeTimingResponse() 730 { 731 makeResponse(); 732 } 733 734 void 735 setFunctionalResponseStatus(bool success) 736 { 737 if (!success) { 738 if (isWrite()) { 739 cmd = MemCmd::FunctionalWriteError; 740 } else { 741 cmd = MemCmd::FunctionalReadError; 742 } 743 } 744 } 745 746 void 747 setSize(unsigned size) 748 { 749 assert(!flags.isSet(VALID_SIZE)); 750 751 this->size = size; 752 flags.set(VALID_SIZE); 753 } 754 755 756 /** 757 * Set the data pointer to the following value that should not be 758 * freed. Static data allows us to do a single memcpy even if 759 * multiple packets are required to get from source to destination 760 * and back. In essence the pointer is set calling dataStatic on 761 * the original packet, and whenever this packet is copied and 762 * forwarded the same pointer is passed on. When a packet 763 * eventually reaches the destination holding the data, it is 764 * copied once into the location originally set. On the way back 765 * to the source, no copies are necessary. 766 */ 767 template <typename T> 768 void 769 dataStatic(T *p) 770 { 771 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 772 data = (PacketDataPtr)p; 773 flags.set(STATIC_DATA); 774 } 775 776 /** 777 * Set the data pointer to the following value that should not be 778 * freed. This version of the function allows the pointer passed 779 * to us to be const. To avoid issues down the line we cast the 780 * constness away, the alternative would be to keep both a const 781 * and non-const data pointer and cleverly choose between 782 * them. Note that this is only allowed for static data. 783 */ 784 template <typename T> 785 void 786 dataStaticConst(const T *p) 787 { 788 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 789 data = const_cast<PacketDataPtr>(p); 790 flags.set(STATIC_DATA); 791 } 792 793 /** 794 * Set the data pointer to a value that should have delete [] 795 * called on it. Dynamic data is local to this packet, and as the 796 * packet travels from source to destination, forwarded packets 797 * will allocate their own data. When a packet reaches the final 798 * destination it will populate the dynamic data of that specific 799 * packet, and on the way back towards the source, memcpy will be 800 * invoked in every step where a new packet was created e.g. in 801 * the caches. Ultimately when the response reaches the source a 802 * final memcpy is needed to extract the data from the packet 803 * before it is deallocated. 804 */ 805 template <typename T> 806 void 807 dataDynamic(T *p) 808 { 809 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 810 data = (PacketDataPtr)p; 811 flags.set(DYNAMIC_DATA); 812 } 813 814 /** 815 * get a pointer to the data ptr. 816 */ 817 template <typename T> 818 T* 819 getPtr() 820 { 821 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA)); 822 return (T*)data; 823 } 824 825 template <typename T> 826 const T* 827 getConstPtr() const 828 { 829 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA)); 830 return (const T*)data; 831 } 832 833 /** 834 * return the value of what is pointed to in the packet. 835 */ 836 template <typename T> 837 T get() const; 838 839 /** 840 * set the value in the data pointer to v. 841 */ 842 template <typename T> 843 void set(T v); 844 845 /** 846 * Copy data into the packet from the provided pointer. 847 */ 848 void 849 setData(const uint8_t *p) 850 { 851 // we should never be copying data onto itself, which means we 852 // must idenfity packets with static data, as they carry the 853 // same pointer from source to destination and back 854 assert(p != getPtr<uint8_t>() || flags.isSet(STATIC_DATA)); 855 856 if (p != getPtr<uint8_t>()) 857 // for packet with allocated dynamic data, we copy data from 858 // one to the other, e.g. a forwarded response to a response 859 std::memcpy(getPtr<uint8_t>(), p, getSize()); 860 } 861 862 /** 863 * Copy data into the packet from the provided block pointer, 864 * which is aligned to the given block size. 865 */ 866 void 867 setDataFromBlock(const uint8_t *blk_data, int blkSize) 868 { 869 setData(blk_data + getOffset(blkSize)); 870 } 871 872 /** 873 * Copy data from the packet to the provided block pointer, which 874 * is aligned to the given block size. 875 */ 876 void 877 writeData(uint8_t *p) const 878 { 879 std::memcpy(p, getConstPtr<uint8_t>(), getSize()); 880 } 881 882 /** 883 * Copy data from the packet to the memory at the provided pointer. 884 */ 885 void 886 writeDataToBlock(uint8_t *blk_data, int blkSize) const 887 { 888 writeData(blk_data + getOffset(blkSize)); 889 } 890 891 /** 892 * delete the data pointed to in the data pointer. Ok to call to 893 * matter how data was allocted. 894 */ 895 void 896 deleteData() 897 { 898 if (flags.isSet(DYNAMIC_DATA)) 899 delete [] data; 900 901 flags.clear(STATIC_DATA|DYNAMIC_DATA); 902 data = NULL; 903 } 904 905 /** Allocate memory for the packet. */ 906 void 907 allocate() 908 { 909 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 910 flags.set(DYNAMIC_DATA); 911 data = new uint8_t[getSize()]; 912 } 913 914 /** 915 * Check a functional request against a memory value stored in 916 * another packet (i.e. an in-transit request or 917 * response). Returns true if the current packet is a read, and 918 * the other packet provides the data, which is then copied to the 919 * current packet. If the current packet is a write, and the other 920 * packet intersects this one, then we update the data 921 * accordingly. 922 */ 923 bool 924 checkFunctional(PacketPtr other) 925 { 926 // all packets that are carrying a payload should have a valid 927 // data pointer 928 return checkFunctional(other, other->getAddr(), other->isSecure(), 929 other->getSize(), 930 other->hasData() ? 931 other->getPtr<uint8_t>() : NULL); 932 } 933 934 /** 935 * Check a functional request against a memory value represented 936 * by a base/size pair and an associated data array. If the 937 * current packet is a read, it may be satisfied by the memory 938 * value. If the current packet is a write, it may update the 939 * memory value. 940 */ 941 bool 942 checkFunctional(Printable *obj, Addr base, bool is_secure, int size, 943 uint8_t *_data); 944 945 /** 946 * Push label for PrintReq (safe to call unconditionally). 947 */ 948 void 949 pushLabel(const std::string &lbl) 950 { 951 if (isPrint()) 952 safe_cast<PrintReqState*>(senderState)->pushLabel(lbl); 953 } 954 955 /** 956 * Pop label for PrintReq (safe to call unconditionally). 957 */ 958 void 959 popLabel() 960 { 961 if (isPrint()) 962 safe_cast<PrintReqState*>(senderState)->popLabel(); 963 } 964 965 void print(std::ostream &o, int verbosity = 0, 966 const std::string &prefix = "") const; 967 968 /** 969 * A no-args wrapper of print(std::ostream...) 970 * meant to be invoked from DPRINTFs 971 * avoiding string overheads in fast mode 972 * @return string with the request's type and start<->end addresses 973 */ 974 std::string print() const; 975}; 976 977#endif //__MEM_PACKET_HH 978