packet.hh revision 12652:bae1a1865204
1/* 2 * Copyright (c) 2012-2018 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 * Nikos Nikoleris 46 */ 47 48/** 49 * @file 50 * Declaration of the Packet class. 51 */ 52 53#ifndef __MEM_PACKET_HH__ 54#define __MEM_PACKET_HH__ 55 56#include <bitset> 57#include <cassert> 58#include <list> 59 60#include "base/cast.hh" 61#include "base/compiler.hh" 62#include "base/flags.hh" 63#include "base/logging.hh" 64#include "base/printable.hh" 65#include "base/types.hh" 66#include "mem/request.hh" 67#include "sim/core.hh" 68 69class Packet; 70typedef Packet *PacketPtr; 71typedef uint8_t* PacketDataPtr; 72typedef std::list<PacketPtr> PacketList; 73typedef uint64_t PacketId; 74 75class MemCmd 76{ 77 friend class Packet; 78 79 public: 80 /** 81 * List of all commands associated with a packet. 82 */ 83 enum Command 84 { 85 InvalidCmd, 86 ReadReq, 87 ReadResp, 88 ReadRespWithInvalidate, 89 WriteReq, 90 WriteResp, 91 WritebackDirty, 92 WritebackClean, 93 WriteClean, // writes dirty data below without evicting 94 CleanEvict, 95 SoftPFReq, 96 HardPFReq, 97 SoftPFResp, 98 HardPFResp, 99 WriteLineReq, 100 UpgradeReq, 101 SCUpgradeReq, // Special "weak" upgrade for StoreCond 102 UpgradeResp, 103 SCUpgradeFailReq, // Failed SCUpgradeReq in MSHR (never sent) 104 UpgradeFailResp, // Valid for SCUpgradeReq only 105 ReadExReq, 106 ReadExResp, 107 ReadCleanReq, 108 ReadSharedReq, 109 LoadLockedReq, 110 StoreCondReq, 111 StoreCondFailReq, // Failed StoreCondReq in MSHR (never sent) 112 StoreCondResp, 113 SwapReq, 114 SwapResp, 115 MessageReq, 116 MessageResp, 117 MemFenceReq, 118 MemFenceResp, 119 CleanSharedReq, 120 CleanSharedResp, 121 CleanInvalidReq, 122 CleanInvalidResp, 123 // Error responses 124 // @TODO these should be classified as responses rather than 125 // requests; coding them as requests initially for backwards 126 // compatibility 127 InvalidDestError, // packet dest field invalid 128 BadAddressError, // memory address invalid 129 FunctionalReadError, // unable to fulfill functional read 130 FunctionalWriteError, // unable to fulfill functional write 131 // Fake simulator-only commands 132 PrintReq, // Print state matching address 133 FlushReq, //request for a cache flush 134 InvalidateReq, // request for address to be invalidated 135 InvalidateResp, 136 NUM_MEM_CMDS 137 }; 138 139 private: 140 /** 141 * List of command attributes. 142 */ 143 enum Attribute 144 { 145 IsRead, //!< Data flows from responder to requester 146 IsWrite, //!< Data flows from requester to responder 147 IsUpgrade, 148 IsInvalidate, 149 IsClean, //!< Cleans any existing dirty blocks 150 NeedsWritable, //!< Requires writable copy to complete in-cache 151 IsRequest, //!< Issued by requester 152 IsResponse, //!< Issue by responder 153 NeedsResponse, //!< Requester needs response from target 154 IsEviction, 155 IsSWPrefetch, 156 IsHWPrefetch, 157 IsLlsc, //!< Alpha/MIPS LL or SC access 158 HasData, //!< There is an associated payload 159 IsError, //!< Error response 160 IsPrint, //!< Print state matching address (for debugging) 161 IsFlush, //!< Flush the address from caches 162 FromCache, //!< Request originated from a caching agent 163 NUM_COMMAND_ATTRIBUTES 164 }; 165 166 /** 167 * Structure that defines attributes and other data associated 168 * with a Command. 169 */ 170 struct CommandInfo 171 { 172 /// Set of attribute flags. 173 const std::bitset<NUM_COMMAND_ATTRIBUTES> attributes; 174 /// Corresponding response for requests; InvalidCmd if no 175 /// response is applicable. 176 const Command response; 177 /// String representation (for printing) 178 const std::string str; 179 }; 180 181 /// Array to map Command enum to associated info. 182 static const CommandInfo commandInfo[]; 183 184 private: 185 186 Command cmd; 187 188 bool 189 testCmdAttrib(MemCmd::Attribute attrib) const 190 { 191 return commandInfo[cmd].attributes[attrib] != 0; 192 } 193 194 public: 195 196 bool isRead() const { return testCmdAttrib(IsRead); } 197 bool isWrite() const { return testCmdAttrib(IsWrite); } 198 bool isUpgrade() const { return testCmdAttrib(IsUpgrade); } 199 bool isRequest() const { return testCmdAttrib(IsRequest); } 200 bool isResponse() const { return testCmdAttrib(IsResponse); } 201 bool needsWritable() const { return testCmdAttrib(NeedsWritable); } 202 bool needsResponse() const { return testCmdAttrib(NeedsResponse); } 203 bool isInvalidate() const { return testCmdAttrib(IsInvalidate); } 204 bool isEviction() const { return testCmdAttrib(IsEviction); } 205 bool isClean() const { return testCmdAttrib(IsClean); } 206 bool fromCache() const { return testCmdAttrib(FromCache); } 207 208 /** 209 * A writeback is an eviction that carries data. 210 */ 211 bool isWriteback() const { return testCmdAttrib(IsEviction) && 212 testCmdAttrib(HasData); } 213 214 /** 215 * Check if this particular packet type carries payload data. Note 216 * that this does not reflect if the data pointer of the packet is 217 * valid or not. 218 */ 219 bool hasData() const { return testCmdAttrib(HasData); } 220 bool isLLSC() const { return testCmdAttrib(IsLlsc); } 221 bool isSWPrefetch() const { return testCmdAttrib(IsSWPrefetch); } 222 bool isHWPrefetch() const { return testCmdAttrib(IsHWPrefetch); } 223 bool isPrefetch() const { return testCmdAttrib(IsSWPrefetch) || 224 testCmdAttrib(IsHWPrefetch); } 225 bool isError() const { return testCmdAttrib(IsError); } 226 bool isPrint() const { return testCmdAttrib(IsPrint); } 227 bool isFlush() const { return testCmdAttrib(IsFlush); } 228 229 Command 230 responseCommand() const 231 { 232 return commandInfo[cmd].response; 233 } 234 235 /// Return the string to a cmd given by idx. 236 const std::string &toString() const { return commandInfo[cmd].str; } 237 int toInt() const { return (int)cmd; } 238 239 MemCmd(Command _cmd) : cmd(_cmd) { } 240 MemCmd(int _cmd) : cmd((Command)_cmd) { } 241 MemCmd() : cmd(InvalidCmd) { } 242 243 bool operator==(MemCmd c2) const { return (cmd == c2.cmd); } 244 bool operator!=(MemCmd c2) const { return (cmd != c2.cmd); } 245}; 246 247/** 248 * A Packet is used to encapsulate a transfer between two objects in 249 * the memory system (e.g., the L1 and L2 cache). (In contrast, a 250 * single Request travels all the way from the requester to the 251 * ultimate destination and back, possibly being conveyed by several 252 * different Packets along the way.) 253 */ 254class Packet : public Printable 255{ 256 public: 257 typedef uint32_t FlagsType; 258 typedef ::Flags<FlagsType> Flags; 259 260 private: 261 262 enum : FlagsType { 263 // Flags to transfer across when copying a packet 264 COPY_FLAGS = 0x0000003F, 265 266 // Does this packet have sharers (which means it should not be 267 // considered writable) or not. See setHasSharers below. 268 HAS_SHARERS = 0x00000001, 269 270 // Special control flags 271 /// Special timing-mode atomic snoop for multi-level coherence. 272 EXPRESS_SNOOP = 0x00000002, 273 274 /// Allow a responding cache to inform the cache hierarchy 275 /// that it had a writable copy before responding. See 276 /// setResponderHadWritable below. 277 RESPONDER_HAD_WRITABLE = 0x00000004, 278 279 // Snoop co-ordination flag to indicate that a cache is 280 // responding to a snoop. See setCacheResponding below. 281 CACHE_RESPONDING = 0x00000008, 282 283 // The writeback/writeclean should be propagated further 284 // downstream by the receiver 285 WRITE_THROUGH = 0x00000010, 286 287 // Response co-ordination flag for cache maintenance 288 // operations 289 SATISFIED = 0x00000020, 290 291 /// Are the 'addr' and 'size' fields valid? 292 VALID_ADDR = 0x00000100, 293 VALID_SIZE = 0x00000200, 294 295 /// Is the data pointer set to a value that shouldn't be freed 296 /// when the packet is destroyed? 297 STATIC_DATA = 0x00001000, 298 /// The data pointer points to a value that should be freed when 299 /// the packet is destroyed. The pointer is assumed to be pointing 300 /// to an array, and delete [] is consequently called 301 DYNAMIC_DATA = 0x00002000, 302 303 /// suppress the error if this packet encounters a functional 304 /// access failure. 305 SUPPRESS_FUNC_ERROR = 0x00008000, 306 307 // Signal block present to squash prefetch and cache evict packets 308 // through express snoop flag 309 BLOCK_CACHED = 0x00010000 310 }; 311 312 Flags flags; 313 314 public: 315 typedef MemCmd::Command Command; 316 317 /// The command field of the packet. 318 MemCmd cmd; 319 320 const PacketId id; 321 322 /// A pointer to the original request. 323 const RequestPtr req; 324 325 private: 326 /** 327 * A pointer to the data being transferred. It can be different 328 * sizes at each level of the hierarchy so it belongs to the 329 * packet, not request. This may or may not be populated when a 330 * responder receives the packet. If not populated memory should 331 * be allocated. 332 */ 333 PacketDataPtr data; 334 335 /// The address of the request. This address could be virtual or 336 /// physical, depending on the system configuration. 337 Addr addr; 338 339 /// True if the request targets the secure memory space. 340 bool _isSecure; 341 342 /// The size of the request or transfer. 343 unsigned size; 344 345 /** 346 * Track the bytes found that satisfy a functional read. 347 */ 348 std::vector<bool> bytesValid; 349 350 public: 351 352 /** 353 * The extra delay from seeing the packet until the header is 354 * transmitted. This delay is used to communicate the crossbar 355 * forwarding latency to the neighbouring object (e.g. a cache) 356 * that actually makes the packet wait. As the delay is relative, 357 * a 32-bit unsigned should be sufficient. 358 */ 359 uint32_t headerDelay; 360 361 /** 362 * Keep track of the extra delay incurred by snooping upwards 363 * before sending a request down the memory system. This is used 364 * by the coherent crossbar to account for the additional request 365 * delay. 366 */ 367 uint32_t snoopDelay; 368 369 /** 370 * The extra pipelining delay from seeing the packet until the end of 371 * payload is transmitted by the component that provided it (if 372 * any). This includes the header delay. Similar to the header 373 * delay, this is used to make up for the fact that the 374 * crossbar does not make the packet wait. As the delay is 375 * relative, a 32-bit unsigned should be sufficient. 376 */ 377 uint32_t payloadDelay; 378 379 /** 380 * A virtual base opaque structure used to hold state associated 381 * with the packet (e.g., an MSHR), specific to a MemObject that 382 * sees the packet. A pointer to this state is returned in the 383 * packet's response so that the MemObject in question can quickly 384 * look up the state needed to process it. A specific subclass 385 * would be derived from this to carry state specific to a 386 * particular sending device. 387 * 388 * As multiple MemObjects may add their SenderState throughout the 389 * memory system, the SenderStates create a stack, where a 390 * MemObject can add a new Senderstate, as long as the 391 * predecessing SenderState is restored when the response comes 392 * back. For this reason, the predecessor should always be 393 * populated with the current SenderState of a packet before 394 * modifying the senderState field in the request packet. 395 */ 396 struct SenderState 397 { 398 SenderState* predecessor; 399 SenderState() : predecessor(NULL) {} 400 virtual ~SenderState() {} 401 }; 402 403 /** 404 * Object used to maintain state of a PrintReq. The senderState 405 * field of a PrintReq should always be of this type. 406 */ 407 class PrintReqState : public SenderState 408 { 409 private: 410 /** 411 * An entry in the label stack. 412 */ 413 struct LabelStackEntry 414 { 415 const std::string label; 416 std::string *prefix; 417 bool labelPrinted; 418 LabelStackEntry(const std::string &_label, std::string *_prefix); 419 }; 420 421 typedef std::list<LabelStackEntry> LabelStack; 422 LabelStack labelStack; 423 424 std::string *curPrefixPtr; 425 426 public: 427 std::ostream &os; 428 const int verbosity; 429 430 PrintReqState(std::ostream &os, int verbosity = 0); 431 ~PrintReqState(); 432 433 /** 434 * Returns the current line prefix. 435 */ 436 const std::string &curPrefix() { return *curPrefixPtr; } 437 438 /** 439 * Push a label onto the label stack, and prepend the given 440 * prefix string onto the current prefix. Labels will only be 441 * printed if an object within the label's scope is printed. 442 */ 443 void pushLabel(const std::string &lbl, 444 const std::string &prefix = " "); 445 446 /** 447 * Pop a label off the label stack. 448 */ 449 void popLabel(); 450 451 /** 452 * Print all of the pending unprinted labels on the 453 * stack. Called by printObj(), so normally not called by 454 * users unless bypassing printObj(). 455 */ 456 void printLabels(); 457 458 /** 459 * Print a Printable object to os, because it matched the 460 * address on a PrintReq. 461 */ 462 void printObj(Printable *obj); 463 }; 464 465 /** 466 * This packet's sender state. Devices should use dynamic_cast<> 467 * to cast to the state appropriate to the sender. The intent of 468 * this variable is to allow a device to attach extra information 469 * to a request. A response packet must return the sender state 470 * that was attached to the original request (even if a new packet 471 * is created). 472 */ 473 SenderState *senderState; 474 475 /** 476 * Push a new sender state to the packet and make the current 477 * sender state the predecessor of the new one. This should be 478 * prefered over direct manipulation of the senderState member 479 * variable. 480 * 481 * @param sender_state SenderState to push at the top of the stack 482 */ 483 void pushSenderState(SenderState *sender_state); 484 485 /** 486 * Pop the top of the state stack and return a pointer to it. This 487 * assumes the current sender state is not NULL. This should be 488 * preferred over direct manipulation of the senderState member 489 * variable. 490 * 491 * @return The current top of the stack 492 */ 493 SenderState *popSenderState(); 494 495 /** 496 * Go through the sender state stack and return the first instance 497 * that is of type T (as determined by a dynamic_cast). If there 498 * is no sender state of type T, NULL is returned. 499 * 500 * @return The topmost state of type T 501 */ 502 template <typename T> 503 T * findNextSenderState() const 504 { 505 T *t = NULL; 506 SenderState* sender_state = senderState; 507 while (t == NULL && sender_state != NULL) { 508 t = dynamic_cast<T*>(sender_state); 509 sender_state = sender_state->predecessor; 510 } 511 return t; 512 } 513 514 /// Return the string name of the cmd field (for debugging and 515 /// tracing). 516 const std::string &cmdString() const { return cmd.toString(); } 517 518 /// Return the index of this command. 519 inline int cmdToIndex() const { return cmd.toInt(); } 520 521 bool isRead() const { return cmd.isRead(); } 522 bool isWrite() const { return cmd.isWrite(); } 523 bool isUpgrade() const { return cmd.isUpgrade(); } 524 bool isRequest() const { return cmd.isRequest(); } 525 bool isResponse() const { return cmd.isResponse(); } 526 bool needsWritable() const 527 { 528 // we should never check if a response needsWritable, the 529 // request has this flag, and for a response we should rather 530 // look at the hasSharers flag (if not set, the response is to 531 // be considered writable) 532 assert(isRequest()); 533 return cmd.needsWritable(); 534 } 535 bool needsResponse() const { return cmd.needsResponse(); } 536 bool isInvalidate() const { return cmd.isInvalidate(); } 537 bool isEviction() const { return cmd.isEviction(); } 538 bool isClean() const { return cmd.isClean(); } 539 bool fromCache() const { return cmd.fromCache(); } 540 bool isWriteback() const { return cmd.isWriteback(); } 541 bool hasData() const { return cmd.hasData(); } 542 bool hasRespData() const 543 { 544 MemCmd resp_cmd = cmd.responseCommand(); 545 return resp_cmd.hasData(); 546 } 547 bool isLLSC() const { return cmd.isLLSC(); } 548 bool isError() const { return cmd.isError(); } 549 bool isPrint() const { return cmd.isPrint(); } 550 bool isFlush() const { return cmd.isFlush(); } 551 552 //@{ 553 /// Snoop flags 554 /** 555 * Set the cacheResponding flag. This is used by the caches to 556 * signal another cache that they are responding to a request. A 557 * cache will only respond to snoops if it has the line in either 558 * Modified or Owned state. Note that on snoop hits we always pass 559 * the line as Modified and never Owned. In the case of an Owned 560 * line we proceed to invalidate all other copies. 561 * 562 * On a cache fill (see Cache::handleFill), we check hasSharers 563 * first, ignoring the cacheResponding flag if hasSharers is set. 564 * A line is consequently allocated as: 565 * 566 * hasSharers cacheResponding state 567 * true false Shared 568 * true true Shared 569 * false false Exclusive 570 * false true Modified 571 */ 572 void setCacheResponding() 573 { 574 assert(isRequest()); 575 assert(!flags.isSet(CACHE_RESPONDING)); 576 flags.set(CACHE_RESPONDING); 577 } 578 bool cacheResponding() const { return flags.isSet(CACHE_RESPONDING); } 579 /** 580 * On fills, the hasSharers flag is used by the caches in 581 * combination with the cacheResponding flag, as clarified 582 * above. If the hasSharers flag is not set, the packet is passing 583 * writable. Thus, a response from a memory passes the line as 584 * writable by default. 585 * 586 * The hasSharers flag is also used by upstream caches to inform a 587 * downstream cache that they have the block (by calling 588 * setHasSharers on snoop request packets that hit in upstream 589 * cachs tags or MSHRs). If the snoop packet has sharers, a 590 * downstream cache is prevented from passing a dirty line upwards 591 * if it was not explicitly asked for a writable copy. See 592 * Cache::satisfyCpuSideRequest. 593 * 594 * The hasSharers flag is also used on writebacks, in 595 * combination with the WritbackClean or WritebackDirty commands, 596 * to allocate the block downstream either as: 597 * 598 * command hasSharers state 599 * WritebackDirty false Modified 600 * WritebackDirty true Owned 601 * WritebackClean false Exclusive 602 * WritebackClean true Shared 603 */ 604 void setHasSharers() { flags.set(HAS_SHARERS); } 605 bool hasSharers() const { return flags.isSet(HAS_SHARERS); } 606 //@} 607 608 /** 609 * The express snoop flag is used for two purposes. Firstly, it is 610 * used to bypass flow control for normal (non-snoop) requests 611 * going downstream in the memory system. In cases where a cache 612 * is responding to a snoop from another cache (it had a dirty 613 * line), but the line is not writable (and there are possibly 614 * other copies), the express snoop flag is set by the downstream 615 * cache to invalidate all other copies in zero time. Secondly, 616 * the express snoop flag is also set to be able to distinguish 617 * snoop packets that came from a downstream cache, rather than 618 * snoop packets from neighbouring caches. 619 */ 620 void setExpressSnoop() { flags.set(EXPRESS_SNOOP); } 621 bool isExpressSnoop() const { return flags.isSet(EXPRESS_SNOOP); } 622 623 /** 624 * On responding to a snoop request (which only happens for 625 * Modified or Owned lines), make sure that we can transform an 626 * Owned response to a Modified one. If this flag is not set, the 627 * responding cache had the line in the Owned state, and there are 628 * possibly other Shared copies in the memory system. A downstream 629 * cache helps in orchestrating the invalidation of these copies 630 * by sending out the appropriate express snoops. 631 */ 632 void setResponderHadWritable() 633 { 634 assert(cacheResponding()); 635 assert(!responderHadWritable()); 636 flags.set(RESPONDER_HAD_WRITABLE); 637 } 638 bool responderHadWritable() const 639 { return flags.isSet(RESPONDER_HAD_WRITABLE); } 640 641 /** 642 * A writeback/writeclean cmd gets propagated further downstream 643 * by the receiver when the flag is set. 644 */ 645 void setWriteThrough() 646 { 647 assert(cmd.isWrite() && 648 (cmd.isEviction() || cmd == MemCmd::WriteClean)); 649 flags.set(WRITE_THROUGH); 650 } 651 void clearWriteThrough() { flags.clear(WRITE_THROUGH); } 652 bool writeThrough() const { return flags.isSet(WRITE_THROUGH); } 653 654 /** 655 * Set when a request hits in a cache and the cache is not going 656 * to respond. This is used by the crossbar to coordinate 657 * responses for cache maintenance operations. 658 */ 659 void setSatisfied() 660 { 661 assert(cmd.isClean()); 662 assert(!flags.isSet(SATISFIED)); 663 flags.set(SATISFIED); 664 } 665 bool satisfied() const { return flags.isSet(SATISFIED); } 666 667 void setSuppressFuncError() { flags.set(SUPPRESS_FUNC_ERROR); } 668 bool suppressFuncError() const { return flags.isSet(SUPPRESS_FUNC_ERROR); } 669 void setBlockCached() { flags.set(BLOCK_CACHED); } 670 bool isBlockCached() const { return flags.isSet(BLOCK_CACHED); } 671 void clearBlockCached() { flags.clear(BLOCK_CACHED); } 672 673 // Network error conditions... encapsulate them as methods since 674 // their encoding keeps changing (from result field to command 675 // field, etc.) 676 void 677 setBadAddress() 678 { 679 assert(isResponse()); 680 cmd = MemCmd::BadAddressError; 681 } 682 683 void copyError(Packet *pkt) { assert(pkt->isError()); cmd = pkt->cmd; } 684 685 Addr getAddr() const { assert(flags.isSet(VALID_ADDR)); return addr; } 686 /** 687 * Update the address of this packet mid-transaction. This is used 688 * by the address mapper to change an already set address to a new 689 * one based on the system configuration. It is intended to remap 690 * an existing address, so it asserts that the current address is 691 * valid. 692 */ 693 void setAddr(Addr _addr) { assert(flags.isSet(VALID_ADDR)); addr = _addr; } 694 695 unsigned getSize() const { assert(flags.isSet(VALID_SIZE)); return size; } 696 697 Addr getOffset(unsigned int blk_size) const 698 { 699 return getAddr() & Addr(blk_size - 1); 700 } 701 702 Addr getBlockAddr(unsigned int blk_size) const 703 { 704 return getAddr() & ~(Addr(blk_size - 1)); 705 } 706 707 bool isSecure() const 708 { 709 assert(flags.isSet(VALID_ADDR)); 710 return _isSecure; 711 } 712 713 /** 714 * Accessor function to atomic op. 715 */ 716 AtomicOpFunctor *getAtomicOp() const { return req->getAtomicOpFunctor(); } 717 bool isAtomicOp() const { return req->isAtomic(); } 718 719 /** 720 * It has been determined that the SC packet should successfully update 721 * memory. Therefore, convert this SC packet to a normal write. 722 */ 723 void 724 convertScToWrite() 725 { 726 assert(isLLSC()); 727 assert(isWrite()); 728 cmd = MemCmd::WriteReq; 729 } 730 731 /** 732 * When ruby is in use, Ruby will monitor the cache line and the 733 * phys memory should treat LL ops as normal reads. 734 */ 735 void 736 convertLlToRead() 737 { 738 assert(isLLSC()); 739 assert(isRead()); 740 cmd = MemCmd::ReadReq; 741 } 742 743 /** 744 * Constructor. Note that a Request object must be constructed 745 * first, but the Requests's physical address and size fields need 746 * not be valid. The command must be supplied. 747 */ 748 Packet(const RequestPtr _req, MemCmd _cmd) 749 : cmd(_cmd), id((PacketId)_req), req(_req), data(nullptr), addr(0), 750 _isSecure(false), size(0), headerDelay(0), snoopDelay(0), 751 payloadDelay(0), senderState(NULL) 752 { 753 if (req->hasPaddr()) { 754 addr = req->getPaddr(); 755 flags.set(VALID_ADDR); 756 _isSecure = req->isSecure(); 757 } 758 if (req->hasSize()) { 759 size = req->getSize(); 760 flags.set(VALID_SIZE); 761 } 762 } 763 764 /** 765 * Alternate constructor if you are trying to create a packet with 766 * a request that is for a whole block, not the address from the 767 * req. this allows for overriding the size/addr of the req. 768 */ 769 Packet(const RequestPtr _req, MemCmd _cmd, int _blkSize, PacketId _id = 0) 770 : cmd(_cmd), id(_id ? _id : (PacketId)_req), req(_req), data(nullptr), 771 addr(0), _isSecure(false), headerDelay(0), snoopDelay(0), 772 payloadDelay(0), senderState(NULL) 773 { 774 if (req->hasPaddr()) { 775 addr = req->getPaddr() & ~(_blkSize - 1); 776 flags.set(VALID_ADDR); 777 _isSecure = req->isSecure(); 778 } 779 size = _blkSize; 780 flags.set(VALID_SIZE); 781 } 782 783 /** 784 * Alternate constructor for copying a packet. Copy all fields 785 * *except* if the original packet's data was dynamic, don't copy 786 * that, as we can't guarantee that the new packet's lifetime is 787 * less than that of the original packet. In this case the new 788 * packet should allocate its own data. 789 */ 790 Packet(const PacketPtr pkt, bool clear_flags, bool alloc_data) 791 : cmd(pkt->cmd), id(pkt->id), req(pkt->req), 792 data(nullptr), 793 addr(pkt->addr), _isSecure(pkt->_isSecure), size(pkt->size), 794 bytesValid(pkt->bytesValid), 795 headerDelay(pkt->headerDelay), 796 snoopDelay(0), 797 payloadDelay(pkt->payloadDelay), 798 senderState(pkt->senderState) 799 { 800 if (!clear_flags) 801 flags.set(pkt->flags & COPY_FLAGS); 802 803 flags.set(pkt->flags & (VALID_ADDR|VALID_SIZE)); 804 805 // should we allocate space for data, or not, the express 806 // snoops do not need to carry any data as they only serve to 807 // co-ordinate state changes 808 if (alloc_data) { 809 // even if asked to allocate data, if the original packet 810 // holds static data, then the sender will not be doing 811 // any memcpy on receiving the response, thus we simply 812 // carry the pointer forward 813 if (pkt->flags.isSet(STATIC_DATA)) { 814 data = pkt->data; 815 flags.set(STATIC_DATA); 816 } else { 817 allocate(); 818 } 819 } 820 } 821 822 /** 823 * Generate the appropriate read MemCmd based on the Request flags. 824 */ 825 static MemCmd 826 makeReadCmd(const RequestPtr req) 827 { 828 if (req->isLLSC()) 829 return MemCmd::LoadLockedReq; 830 else if (req->isPrefetch()) 831 return MemCmd::SoftPFReq; 832 else 833 return MemCmd::ReadReq; 834 } 835 836 /** 837 * Generate the appropriate write MemCmd based on the Request flags. 838 */ 839 static MemCmd 840 makeWriteCmd(const RequestPtr req) 841 { 842 if (req->isLLSC()) 843 return MemCmd::StoreCondReq; 844 else if (req->isSwap()) 845 return MemCmd::SwapReq; 846 else if (req->isCacheInvalidate()) { 847 return req->isCacheClean() ? MemCmd::CleanInvalidReq : 848 MemCmd::InvalidateReq; 849 } else if (req->isCacheClean()) { 850 return MemCmd::CleanSharedReq; 851 } else 852 return MemCmd::WriteReq; 853 } 854 855 /** 856 * Constructor-like methods that return Packets based on Request objects. 857 * Fine-tune the MemCmd type if it's not a vanilla read or write. 858 */ 859 static PacketPtr 860 createRead(const RequestPtr req) 861 { 862 return new Packet(req, makeReadCmd(req)); 863 } 864 865 static PacketPtr 866 createWrite(const RequestPtr req) 867 { 868 return new Packet(req, makeWriteCmd(req)); 869 } 870 871 /** 872 * clean up packet variables 873 */ 874 ~Packet() 875 { 876 // Delete the request object if this is a request packet which 877 // does not need a response, because the requester will not get 878 // a chance. If the request packet needs a response then the 879 // request will be deleted on receipt of the response 880 // packet. We also make sure to never delete the request for 881 // express snoops, even for cases when responses are not 882 // needed (CleanEvict and Writeback), since the snoop packet 883 // re-uses the same request. 884 if (req && isRequest() && !needsResponse() && 885 !isExpressSnoop()) { 886 delete req; 887 } 888 deleteData(); 889 } 890 891 /** 892 * Take a request packet and modify it in place to be suitable for 893 * returning as a response to that request. 894 */ 895 void 896 makeResponse() 897 { 898 assert(needsResponse()); 899 assert(isRequest()); 900 cmd = cmd.responseCommand(); 901 902 // responses are never express, even if the snoop that 903 // triggered them was 904 flags.clear(EXPRESS_SNOOP); 905 } 906 907 void 908 makeAtomicResponse() 909 { 910 makeResponse(); 911 } 912 913 void 914 makeTimingResponse() 915 { 916 makeResponse(); 917 } 918 919 void 920 setFunctionalResponseStatus(bool success) 921 { 922 if (!success) { 923 if (isWrite()) { 924 cmd = MemCmd::FunctionalWriteError; 925 } else { 926 cmd = MemCmd::FunctionalReadError; 927 } 928 } 929 } 930 931 void 932 setSize(unsigned size) 933 { 934 assert(!flags.isSet(VALID_SIZE)); 935 936 this->size = size; 937 flags.set(VALID_SIZE); 938 } 939 940 941 public: 942 /** 943 * @{ 944 * @name Data accessor mehtods 945 */ 946 947 /** 948 * Set the data pointer to the following value that should not be 949 * freed. Static data allows us to do a single memcpy even if 950 * multiple packets are required to get from source to destination 951 * and back. In essence the pointer is set calling dataStatic on 952 * the original packet, and whenever this packet is copied and 953 * forwarded the same pointer is passed on. When a packet 954 * eventually reaches the destination holding the data, it is 955 * copied once into the location originally set. On the way back 956 * to the source, no copies are necessary. 957 */ 958 template <typename T> 959 void 960 dataStatic(T *p) 961 { 962 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 963 data = (PacketDataPtr)p; 964 flags.set(STATIC_DATA); 965 } 966 967 /** 968 * Set the data pointer to the following value that should not be 969 * freed. This version of the function allows the pointer passed 970 * to us to be const. To avoid issues down the line we cast the 971 * constness away, the alternative would be to keep both a const 972 * and non-const data pointer and cleverly choose between 973 * them. Note that this is only allowed for static data. 974 */ 975 template <typename T> 976 void 977 dataStaticConst(const T *p) 978 { 979 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 980 data = const_cast<PacketDataPtr>(p); 981 flags.set(STATIC_DATA); 982 } 983 984 /** 985 * Set the data pointer to a value that should have delete [] 986 * called on it. Dynamic data is local to this packet, and as the 987 * packet travels from source to destination, forwarded packets 988 * will allocate their own data. When a packet reaches the final 989 * destination it will populate the dynamic data of that specific 990 * packet, and on the way back towards the source, memcpy will be 991 * invoked in every step where a new packet was created e.g. in 992 * the caches. Ultimately when the response reaches the source a 993 * final memcpy is needed to extract the data from the packet 994 * before it is deallocated. 995 */ 996 template <typename T> 997 void 998 dataDynamic(T *p) 999 { 1000 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 1001 data = (PacketDataPtr)p; 1002 flags.set(DYNAMIC_DATA); 1003 } 1004 1005 /** 1006 * get a pointer to the data ptr. 1007 */ 1008 template <typename T> 1009 T* 1010 getPtr() 1011 { 1012 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA)); 1013 return (T*)data; 1014 } 1015 1016 template <typename T> 1017 const T* 1018 getConstPtr() const 1019 { 1020 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA)); 1021 return (const T*)data; 1022 } 1023 1024 /** 1025 * Get the data in the packet byte swapped from big endian to 1026 * host endian. 1027 */ 1028 template <typename T> 1029 T getBE() const; 1030 1031 /** 1032 * Get the data in the packet byte swapped from little endian to 1033 * host endian. 1034 */ 1035 template <typename T> 1036 T getLE() const; 1037 1038 /** 1039 * Get the data in the packet byte swapped from the specified 1040 * endianness. 1041 */ 1042 template <typename T> 1043 T get(ByteOrder endian) const; 1044 1045 /** 1046 * Get the data in the packet byte swapped from guest to host 1047 * endian. 1048 */ 1049 template <typename T> 1050 T get() const; 1051 1052 /** Set the value in the data pointer to v as big endian. */ 1053 template <typename T> 1054 void setBE(T v); 1055 1056 /** Set the value in the data pointer to v as little endian. */ 1057 template <typename T> 1058 void setLE(T v); 1059 1060 /** 1061 * Set the value in the data pointer to v using the specified 1062 * endianness. 1063 */ 1064 template <typename T> 1065 void set(T v, ByteOrder endian); 1066 1067 /** Set the value in the data pointer to v as guest endian. */ 1068 template <typename T> 1069 void set(T v); 1070 1071 1072 /** 1073 * Get the data in the packet byte swapped from the specified 1074 * endianness and zero-extended to 64 bits. 1075 */ 1076 uint64_t getUintX(ByteOrder endian) const; 1077 1078 /** 1079 * Set the value in the word w after truncating it to the length 1080 * of the packet and then byteswapping it to the desired 1081 * endianness. 1082 */ 1083 void setUintX(uint64_t w, ByteOrder endian); 1084 1085 /** 1086 * Copy data into the packet from the provided pointer. 1087 */ 1088 void 1089 setData(const uint8_t *p) 1090 { 1091 // we should never be copying data onto itself, which means we 1092 // must idenfity packets with static data, as they carry the 1093 // same pointer from source to destination and back 1094 assert(p != getPtr<uint8_t>() || flags.isSet(STATIC_DATA)); 1095 1096 if (p != getPtr<uint8_t>()) 1097 // for packet with allocated dynamic data, we copy data from 1098 // one to the other, e.g. a forwarded response to a response 1099 std::memcpy(getPtr<uint8_t>(), p, getSize()); 1100 } 1101 1102 /** 1103 * Copy data into the packet from the provided block pointer, 1104 * which is aligned to the given block size. 1105 */ 1106 void 1107 setDataFromBlock(const uint8_t *blk_data, int blkSize) 1108 { 1109 setData(blk_data + getOffset(blkSize)); 1110 } 1111 1112 /** 1113 * Copy data from the packet to the memory at the provided pointer. 1114 * @param p Pointer to which data will be copied. 1115 */ 1116 void 1117 writeData(uint8_t *p) const 1118 { 1119 std::memcpy(p, getConstPtr<uint8_t>(), getSize()); 1120 } 1121 1122 /** 1123 * Copy data from the packet to the provided block pointer, which 1124 * is aligned to the given block size. 1125 * @param blk_data Pointer to block to which data will be copied. 1126 * @param blkSize Block size in bytes. 1127 */ 1128 void 1129 writeDataToBlock(uint8_t *blk_data, int blkSize) const 1130 { 1131 writeData(blk_data + getOffset(blkSize)); 1132 } 1133 1134 /** 1135 * delete the data pointed to in the data pointer. Ok to call to 1136 * matter how data was allocted. 1137 */ 1138 void 1139 deleteData() 1140 { 1141 if (flags.isSet(DYNAMIC_DATA)) 1142 delete [] data; 1143 1144 flags.clear(STATIC_DATA|DYNAMIC_DATA); 1145 data = NULL; 1146 } 1147 1148 /** Allocate memory for the packet. */ 1149 void 1150 allocate() 1151 { 1152 // if either this command or the response command has a data 1153 // payload, actually allocate space 1154 if (hasData() || hasRespData()) { 1155 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 1156 flags.set(DYNAMIC_DATA); 1157 data = new uint8_t[getSize()]; 1158 } 1159 } 1160 1161 /** @} */ 1162 1163 private: // Private data accessor methods 1164 /** Get the data in the packet without byte swapping. */ 1165 template <typename T> 1166 T getRaw() const; 1167 1168 /** Set the value in the data pointer to v without byte swapping. */ 1169 template <typename T> 1170 void setRaw(T v); 1171 1172 public: 1173 /** 1174 * Check a functional request against a memory value stored in 1175 * another packet (i.e. an in-transit request or 1176 * response). Returns true if the current packet is a read, and 1177 * the other packet provides the data, which is then copied to the 1178 * current packet. If the current packet is a write, and the other 1179 * packet intersects this one, then we update the data 1180 * accordingly. 1181 */ 1182 bool 1183 checkFunctional(PacketPtr other) 1184 { 1185 // all packets that are carrying a payload should have a valid 1186 // data pointer 1187 return checkFunctional(other, other->getAddr(), other->isSecure(), 1188 other->getSize(), 1189 other->hasData() ? 1190 other->getPtr<uint8_t>() : NULL); 1191 } 1192 1193 /** 1194 * Does the request need to check for cached copies of the same block 1195 * in the memory hierarchy above. 1196 **/ 1197 bool 1198 mustCheckAbove() const 1199 { 1200 return cmd == MemCmd::HardPFReq || isEviction(); 1201 } 1202 1203 /** 1204 * Is this packet a clean eviction, including both actual clean 1205 * evict packets, but also clean writebacks. 1206 */ 1207 bool 1208 isCleanEviction() const 1209 { 1210 return cmd == MemCmd::CleanEvict || cmd == MemCmd::WritebackClean; 1211 } 1212 1213 /** 1214 * Check a functional request against a memory value represented 1215 * by a base/size pair and an associated data array. If the 1216 * current packet is a read, it may be satisfied by the memory 1217 * value. If the current packet is a write, it may update the 1218 * memory value. 1219 */ 1220 bool 1221 checkFunctional(Printable *obj, Addr base, bool is_secure, int size, 1222 uint8_t *_data); 1223 1224 /** 1225 * Push label for PrintReq (safe to call unconditionally). 1226 */ 1227 void 1228 pushLabel(const std::string &lbl) 1229 { 1230 if (isPrint()) 1231 safe_cast<PrintReqState*>(senderState)->pushLabel(lbl); 1232 } 1233 1234 /** 1235 * Pop label for PrintReq (safe to call unconditionally). 1236 */ 1237 void 1238 popLabel() 1239 { 1240 if (isPrint()) 1241 safe_cast<PrintReqState*>(senderState)->popLabel(); 1242 } 1243 1244 void print(std::ostream &o, int verbosity = 0, 1245 const std::string &prefix = "") const; 1246 1247 /** 1248 * A no-args wrapper of print(std::ostream...) 1249 * meant to be invoked from DPRINTFs 1250 * avoiding string overheads in fast mode 1251 * @return string with the request's type and start<->end addresses 1252 */ 1253 std::string print() const; 1254}; 1255 1256#endif //__MEM_PACKET_HH 1257