packet.hh revision 13367:dc06baae4275
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 "config/the_isa.hh" 67#include "mem/request.hh" 68#include "sim/core.hh" 69 70class Packet; 71typedef Packet *PacketPtr; 72typedef uint8_t* PacketDataPtr; 73typedef std::list<PacketPtr> PacketList; 74typedef uint64_t PacketId; 75 76class MemCmd 77{ 78 friend class Packet; 79 80 public: 81 /** 82 * List of all commands associated with a packet. 83 */ 84 enum Command 85 { 86 InvalidCmd, 87 ReadReq, 88 ReadResp, 89 ReadRespWithInvalidate, 90 WriteReq, 91 WriteResp, 92 WritebackDirty, 93 WritebackClean, 94 WriteClean, // writes dirty data below without evicting 95 CleanEvict, 96 SoftPFReq, 97 SoftPFExReq, 98 HardPFReq, 99 SoftPFResp, 100 HardPFResp, 101 WriteLineReq, 102 UpgradeReq, 103 SCUpgradeReq, // Special "weak" upgrade for StoreCond 104 UpgradeResp, 105 SCUpgradeFailReq, // Failed SCUpgradeReq in MSHR (never sent) 106 UpgradeFailResp, // Valid for SCUpgradeReq only 107 ReadExReq, 108 ReadExResp, 109 ReadCleanReq, 110 ReadSharedReq, 111 LoadLockedReq, 112 StoreCondReq, 113 StoreCondFailReq, // Failed StoreCondReq in MSHR (never sent) 114 StoreCondResp, 115 SwapReq, 116 SwapResp, 117 MessageReq, 118 MessageResp, 119 MemFenceReq, 120 MemFenceResp, 121 CleanSharedReq, 122 CleanSharedResp, 123 CleanInvalidReq, 124 CleanInvalidResp, 125 // Error responses 126 // @TODO these should be classified as responses rather than 127 // requests; coding them as requests initially for backwards 128 // compatibility 129 InvalidDestError, // packet dest field invalid 130 BadAddressError, // memory address invalid 131 FunctionalReadError, // unable to fulfill functional read 132 FunctionalWriteError, // unable to fulfill functional write 133 // Fake simulator-only commands 134 PrintReq, // Print state matching address 135 FlushReq, //request for a cache flush 136 InvalidateReq, // request for address to be invalidated 137 InvalidateResp, 138 NUM_MEM_CMDS 139 }; 140 141 private: 142 /** 143 * List of command attributes. 144 */ 145 enum Attribute 146 { 147 IsRead, //!< Data flows from responder to requester 148 IsWrite, //!< Data flows from requester to responder 149 IsUpgrade, 150 IsInvalidate, 151 IsClean, //!< Cleans any existing dirty blocks 152 NeedsWritable, //!< Requires writable copy to complete in-cache 153 IsRequest, //!< Issued by requester 154 IsResponse, //!< Issue by responder 155 NeedsResponse, //!< Requester needs response from target 156 IsEviction, 157 IsSWPrefetch, 158 IsHWPrefetch, 159 IsLlsc, //!< Alpha/MIPS LL or SC access 160 HasData, //!< There is an associated payload 161 IsError, //!< Error response 162 IsPrint, //!< Print state matching address (for debugging) 163 IsFlush, //!< Flush the address from caches 164 FromCache, //!< Request originated from a caching agent 165 NUM_COMMAND_ATTRIBUTES 166 }; 167 168 /** 169 * Structure that defines attributes and other data associated 170 * with a Command. 171 */ 172 struct CommandInfo 173 { 174 /// Set of attribute flags. 175 const std::bitset<NUM_COMMAND_ATTRIBUTES> attributes; 176 /// Corresponding response for requests; InvalidCmd if no 177 /// response is applicable. 178 const Command response; 179 /// String representation (for printing) 180 const std::string str; 181 }; 182 183 /// Array to map Command enum to associated info. 184 static const CommandInfo commandInfo[]; 185 186 private: 187 188 Command cmd; 189 190 bool 191 testCmdAttrib(MemCmd::Attribute attrib) const 192 { 193 return commandInfo[cmd].attributes[attrib] != 0; 194 } 195 196 public: 197 198 bool isRead() const { return testCmdAttrib(IsRead); } 199 bool isWrite() const { return testCmdAttrib(IsWrite); } 200 bool isUpgrade() const { return testCmdAttrib(IsUpgrade); } 201 bool isRequest() const { return testCmdAttrib(IsRequest); } 202 bool isResponse() const { return testCmdAttrib(IsResponse); } 203 bool needsWritable() const { return testCmdAttrib(NeedsWritable); } 204 bool needsResponse() const { return testCmdAttrib(NeedsResponse); } 205 bool isInvalidate() const { return testCmdAttrib(IsInvalidate); } 206 bool isEviction() const { return testCmdAttrib(IsEviction); } 207 bool isClean() const { return testCmdAttrib(IsClean); } 208 bool fromCache() const { return testCmdAttrib(FromCache); } 209 210 /** 211 * A writeback is an eviction that carries data. 212 */ 213 bool isWriteback() const { return testCmdAttrib(IsEviction) && 214 testCmdAttrib(HasData); } 215 216 /** 217 * Check if this particular packet type carries payload data. Note 218 * that this does not reflect if the data pointer of the packet is 219 * valid or not. 220 */ 221 bool hasData() const { return testCmdAttrib(HasData); } 222 bool isLLSC() const { return testCmdAttrib(IsLlsc); } 223 bool isSWPrefetch() const { return testCmdAttrib(IsSWPrefetch); } 224 bool isHWPrefetch() const { return testCmdAttrib(IsHWPrefetch); } 225 bool isPrefetch() const { return testCmdAttrib(IsSWPrefetch) || 226 testCmdAttrib(IsHWPrefetch); } 227 bool isError() const { return testCmdAttrib(IsError); } 228 bool isPrint() const { return testCmdAttrib(IsPrint); } 229 bool isFlush() const { return testCmdAttrib(IsFlush); } 230 231 Command 232 responseCommand() const 233 { 234 return commandInfo[cmd].response; 235 } 236 237 /// Return the string to a cmd given by idx. 238 const std::string &toString() const { return commandInfo[cmd].str; } 239 int toInt() const { return (int)cmd; } 240 241 MemCmd(Command _cmd) : cmd(_cmd) { } 242 MemCmd(int _cmd) : cmd((Command)_cmd) { } 243 MemCmd() : cmd(InvalidCmd) { } 244 245 bool operator==(MemCmd c2) const { return (cmd == c2.cmd); } 246 bool operator!=(MemCmd c2) const { return (cmd != c2.cmd); } 247}; 248 249/** 250 * A Packet is used to encapsulate a transfer between two objects in 251 * the memory system (e.g., the L1 and L2 cache). (In contrast, a 252 * single Request travels all the way from the requester to the 253 * ultimate destination and back, possibly being conveyed by several 254 * different Packets along the way.) 255 */ 256class Packet : public Printable 257{ 258 public: 259 typedef uint32_t FlagsType; 260 typedef ::Flags<FlagsType> Flags; 261 262 private: 263 264 enum : FlagsType { 265 // Flags to transfer across when copying a packet 266 COPY_FLAGS = 0x0000003F, 267 268 // Does this packet have sharers (which means it should not be 269 // considered writable) or not. See setHasSharers below. 270 HAS_SHARERS = 0x00000001, 271 272 // Special control flags 273 /// Special timing-mode atomic snoop for multi-level coherence. 274 EXPRESS_SNOOP = 0x00000002, 275 276 /// Allow a responding cache to inform the cache hierarchy 277 /// that it had a writable copy before responding. See 278 /// setResponderHadWritable below. 279 RESPONDER_HAD_WRITABLE = 0x00000004, 280 281 // Snoop co-ordination flag to indicate that a cache is 282 // responding to a snoop. See setCacheResponding below. 283 CACHE_RESPONDING = 0x00000008, 284 285 // The writeback/writeclean should be propagated further 286 // downstream by the receiver 287 WRITE_THROUGH = 0x00000010, 288 289 // Response co-ordination flag for cache maintenance 290 // operations 291 SATISFIED = 0x00000020, 292 293 /// Are the 'addr' and 'size' fields valid? 294 VALID_ADDR = 0x00000100, 295 VALID_SIZE = 0x00000200, 296 297 /// Is the data pointer set to a value that shouldn't be freed 298 /// when the packet is destroyed? 299 STATIC_DATA = 0x00001000, 300 /// The data pointer points to a value that should be freed when 301 /// the packet is destroyed. The pointer is assumed to be pointing 302 /// to an array, and delete [] is consequently called 303 DYNAMIC_DATA = 0x00002000, 304 305 /// suppress the error if this packet encounters a functional 306 /// access failure. 307 SUPPRESS_FUNC_ERROR = 0x00008000, 308 309 // Signal block present to squash prefetch and cache evict packets 310 // through express snoop flag 311 BLOCK_CACHED = 0x00010000 312 }; 313 314 Flags flags; 315 316 public: 317 typedef MemCmd::Command Command; 318 319 /// The command field of the packet. 320 MemCmd cmd; 321 322 const PacketId id; 323 324 /// A pointer to the original request. 325 RequestPtr req; 326 327 private: 328 /** 329 * A pointer to the data being transferred. It can be different 330 * sizes at each level of the hierarchy so it belongs to the 331 * packet, not request. This may or may not be populated when a 332 * responder receives the packet. If not populated memory should 333 * be allocated. 334 */ 335 PacketDataPtr data; 336 337 /// The address of the request. This address could be virtual or 338 /// physical, depending on the system configuration. 339 Addr addr; 340 341 /// True if the request targets the secure memory space. 342 bool _isSecure; 343 344 /// The size of the request or transfer. 345 unsigned size; 346 347 /** 348 * Track the bytes found that satisfy a functional read. 349 */ 350 std::vector<bool> bytesValid; 351 352 // Quality of Service priority value 353 uint8_t _qosValue; 354 355 public: 356 357 /** 358 * The extra delay from seeing the packet until the header is 359 * transmitted. This delay is used to communicate the crossbar 360 * forwarding latency to the neighbouring object (e.g. a cache) 361 * that actually makes the packet wait. As the delay is relative, 362 * a 32-bit unsigned should be sufficient. 363 */ 364 uint32_t headerDelay; 365 366 /** 367 * Keep track of the extra delay incurred by snooping upwards 368 * before sending a request down the memory system. This is used 369 * by the coherent crossbar to account for the additional request 370 * delay. 371 */ 372 uint32_t snoopDelay; 373 374 /** 375 * The extra pipelining delay from seeing the packet until the end of 376 * payload is transmitted by the component that provided it (if 377 * any). This includes the header delay. Similar to the header 378 * delay, this is used to make up for the fact that the 379 * crossbar does not make the packet wait. As the delay is 380 * relative, a 32-bit unsigned should be sufficient. 381 */ 382 uint32_t payloadDelay; 383 384 /** 385 * A virtual base opaque structure used to hold state associated 386 * with the packet (e.g., an MSHR), specific to a MemObject that 387 * sees the packet. A pointer to this state is returned in the 388 * packet's response so that the MemObject in question can quickly 389 * look up the state needed to process it. A specific subclass 390 * would be derived from this to carry state specific to a 391 * particular sending device. 392 * 393 * As multiple MemObjects may add their SenderState throughout the 394 * memory system, the SenderStates create a stack, where a 395 * MemObject can add a new Senderstate, as long as the 396 * predecessing SenderState is restored when the response comes 397 * back. For this reason, the predecessor should always be 398 * populated with the current SenderState of a packet before 399 * modifying the senderState field in the request packet. 400 */ 401 struct SenderState 402 { 403 SenderState* predecessor; 404 SenderState() : predecessor(NULL) {} 405 virtual ~SenderState() {} 406 }; 407 408 /** 409 * Object used to maintain state of a PrintReq. The senderState 410 * field of a PrintReq should always be of this type. 411 */ 412 class PrintReqState : public SenderState 413 { 414 private: 415 /** 416 * An entry in the label stack. 417 */ 418 struct LabelStackEntry 419 { 420 const std::string label; 421 std::string *prefix; 422 bool labelPrinted; 423 LabelStackEntry(const std::string &_label, std::string *_prefix); 424 }; 425 426 typedef std::list<LabelStackEntry> LabelStack; 427 LabelStack labelStack; 428 429 std::string *curPrefixPtr; 430 431 public: 432 std::ostream &os; 433 const int verbosity; 434 435 PrintReqState(std::ostream &os, int verbosity = 0); 436 ~PrintReqState(); 437 438 /** 439 * Returns the current line prefix. 440 */ 441 const std::string &curPrefix() { return *curPrefixPtr; } 442 443 /** 444 * Push a label onto the label stack, and prepend the given 445 * prefix string onto the current prefix. Labels will only be 446 * printed if an object within the label's scope is printed. 447 */ 448 void pushLabel(const std::string &lbl, 449 const std::string &prefix = " "); 450 451 /** 452 * Pop a label off the label stack. 453 */ 454 void popLabel(); 455 456 /** 457 * Print all of the pending unprinted labels on the 458 * stack. Called by printObj(), so normally not called by 459 * users unless bypassing printObj(). 460 */ 461 void printLabels(); 462 463 /** 464 * Print a Printable object to os, because it matched the 465 * address on a PrintReq. 466 */ 467 void printObj(Printable *obj); 468 }; 469 470 /** 471 * This packet's sender state. Devices should use dynamic_cast<> 472 * to cast to the state appropriate to the sender. The intent of 473 * this variable is to allow a device to attach extra information 474 * to a request. A response packet must return the sender state 475 * that was attached to the original request (even if a new packet 476 * is created). 477 */ 478 SenderState *senderState; 479 480 /** 481 * Push a new sender state to the packet and make the current 482 * sender state the predecessor of the new one. This should be 483 * prefered over direct manipulation of the senderState member 484 * variable. 485 * 486 * @param sender_state SenderState to push at the top of the stack 487 */ 488 void pushSenderState(SenderState *sender_state); 489 490 /** 491 * Pop the top of the state stack and return a pointer to it. This 492 * assumes the current sender state is not NULL. This should be 493 * preferred over direct manipulation of the senderState member 494 * variable. 495 * 496 * @return The current top of the stack 497 */ 498 SenderState *popSenderState(); 499 500 /** 501 * Go through the sender state stack and return the first instance 502 * that is of type T (as determined by a dynamic_cast). If there 503 * is no sender state of type T, NULL is returned. 504 * 505 * @return The topmost state of type T 506 */ 507 template <typename T> 508 T * findNextSenderState() const 509 { 510 T *t = NULL; 511 SenderState* sender_state = senderState; 512 while (t == NULL && sender_state != NULL) { 513 t = dynamic_cast<T*>(sender_state); 514 sender_state = sender_state->predecessor; 515 } 516 return t; 517 } 518 519 /// Return the string name of the cmd field (for debugging and 520 /// tracing). 521 const std::string &cmdString() const { return cmd.toString(); } 522 523 /// Return the index of this command. 524 inline int cmdToIndex() const { return cmd.toInt(); } 525 526 bool isRead() const { return cmd.isRead(); } 527 bool isWrite() const { return cmd.isWrite(); } 528 bool isUpgrade() const { return cmd.isUpgrade(); } 529 bool isRequest() const { return cmd.isRequest(); } 530 bool isResponse() const { return cmd.isResponse(); } 531 bool needsWritable() const 532 { 533 // we should never check if a response needsWritable, the 534 // request has this flag, and for a response we should rather 535 // look at the hasSharers flag (if not set, the response is to 536 // be considered writable) 537 assert(isRequest()); 538 return cmd.needsWritable(); 539 } 540 bool needsResponse() const { return cmd.needsResponse(); } 541 bool isInvalidate() const { return cmd.isInvalidate(); } 542 bool isEviction() const { return cmd.isEviction(); } 543 bool isClean() const { return cmd.isClean(); } 544 bool fromCache() const { return cmd.fromCache(); } 545 bool isWriteback() const { return cmd.isWriteback(); } 546 bool hasData() const { return cmd.hasData(); } 547 bool hasRespData() const 548 { 549 MemCmd resp_cmd = cmd.responseCommand(); 550 return resp_cmd.hasData(); 551 } 552 bool isLLSC() const { return cmd.isLLSC(); } 553 bool isError() const { return cmd.isError(); } 554 bool isPrint() const { return cmd.isPrint(); } 555 bool isFlush() const { return cmd.isFlush(); } 556 557 bool isWholeLineWrite(unsigned blk_size) 558 { 559 return (cmd == MemCmd::WriteReq || cmd == MemCmd::WriteLineReq) && 560 getOffset(blk_size) == 0 && getSize() == blk_size; 561 } 562 563 //@{ 564 /// Snoop flags 565 /** 566 * Set the cacheResponding flag. This is used by the caches to 567 * signal another cache that they are responding to a request. A 568 * cache will only respond to snoops if it has the line in either 569 * Modified or Owned state. Note that on snoop hits we always pass 570 * the line as Modified and never Owned. In the case of an Owned 571 * line we proceed to invalidate all other copies. 572 * 573 * On a cache fill (see Cache::handleFill), we check hasSharers 574 * first, ignoring the cacheResponding flag if hasSharers is set. 575 * A line is consequently allocated as: 576 * 577 * hasSharers cacheResponding state 578 * true false Shared 579 * true true Shared 580 * false false Exclusive 581 * false true Modified 582 */ 583 void setCacheResponding() 584 { 585 assert(isRequest()); 586 assert(!flags.isSet(CACHE_RESPONDING)); 587 flags.set(CACHE_RESPONDING); 588 } 589 bool cacheResponding() const { return flags.isSet(CACHE_RESPONDING); } 590 /** 591 * On fills, the hasSharers flag is used by the caches in 592 * combination with the cacheResponding flag, as clarified 593 * above. If the hasSharers flag is not set, the packet is passing 594 * writable. Thus, a response from a memory passes the line as 595 * writable by default. 596 * 597 * The hasSharers flag is also used by upstream caches to inform a 598 * downstream cache that they have the block (by calling 599 * setHasSharers on snoop request packets that hit in upstream 600 * cachs tags or MSHRs). If the snoop packet has sharers, a 601 * downstream cache is prevented from passing a dirty line upwards 602 * if it was not explicitly asked for a writable copy. See 603 * Cache::satisfyCpuSideRequest. 604 * 605 * The hasSharers flag is also used on writebacks, in 606 * combination with the WritbackClean or WritebackDirty commands, 607 * to allocate the block downstream either as: 608 * 609 * command hasSharers state 610 * WritebackDirty false Modified 611 * WritebackDirty true Owned 612 * WritebackClean false Exclusive 613 * WritebackClean true Shared 614 */ 615 void setHasSharers() { flags.set(HAS_SHARERS); } 616 bool hasSharers() const { return flags.isSet(HAS_SHARERS); } 617 //@} 618 619 /** 620 * The express snoop flag is used for two purposes. Firstly, it is 621 * used to bypass flow control for normal (non-snoop) requests 622 * going downstream in the memory system. In cases where a cache 623 * is responding to a snoop from another cache (it had a dirty 624 * line), but the line is not writable (and there are possibly 625 * other copies), the express snoop flag is set by the downstream 626 * cache to invalidate all other copies in zero time. Secondly, 627 * the express snoop flag is also set to be able to distinguish 628 * snoop packets that came from a downstream cache, rather than 629 * snoop packets from neighbouring caches. 630 */ 631 void setExpressSnoop() { flags.set(EXPRESS_SNOOP); } 632 bool isExpressSnoop() const { return flags.isSet(EXPRESS_SNOOP); } 633 634 /** 635 * On responding to a snoop request (which only happens for 636 * Modified or Owned lines), make sure that we can transform an 637 * Owned response to a Modified one. If this flag is not set, the 638 * responding cache had the line in the Owned state, and there are 639 * possibly other Shared copies in the memory system. A downstream 640 * cache helps in orchestrating the invalidation of these copies 641 * by sending out the appropriate express snoops. 642 */ 643 void setResponderHadWritable() 644 { 645 assert(cacheResponding()); 646 assert(!responderHadWritable()); 647 flags.set(RESPONDER_HAD_WRITABLE); 648 } 649 bool responderHadWritable() const 650 { return flags.isSet(RESPONDER_HAD_WRITABLE); } 651 652 /** 653 * A writeback/writeclean cmd gets propagated further downstream 654 * by the receiver when the flag is set. 655 */ 656 void setWriteThrough() 657 { 658 assert(cmd.isWrite() && 659 (cmd.isEviction() || cmd == MemCmd::WriteClean)); 660 flags.set(WRITE_THROUGH); 661 } 662 void clearWriteThrough() { flags.clear(WRITE_THROUGH); } 663 bool writeThrough() const { return flags.isSet(WRITE_THROUGH); } 664 665 /** 666 * Set when a request hits in a cache and the cache is not going 667 * to respond. This is used by the crossbar to coordinate 668 * responses for cache maintenance operations. 669 */ 670 void setSatisfied() 671 { 672 assert(cmd.isClean()); 673 assert(!flags.isSet(SATISFIED)); 674 flags.set(SATISFIED); 675 } 676 bool satisfied() const { return flags.isSet(SATISFIED); } 677 678 void setSuppressFuncError() { flags.set(SUPPRESS_FUNC_ERROR); } 679 bool suppressFuncError() const { return flags.isSet(SUPPRESS_FUNC_ERROR); } 680 void setBlockCached() { flags.set(BLOCK_CACHED); } 681 bool isBlockCached() const { return flags.isSet(BLOCK_CACHED); } 682 void clearBlockCached() { flags.clear(BLOCK_CACHED); } 683 684 /** 685 * QoS Value getter 686 * Returns 0 if QoS value was never set (constructor default). 687 * 688 * @return QoS priority value of the packet 689 */ 690 inline uint8_t qosValue() const { return _qosValue; } 691 692 /** 693 * QoS Value setter 694 * Interface for setting QoS priority value of the packet. 695 * 696 * @param qos_value QoS priority value 697 */ 698 inline void qosValue(const uint8_t qos_value) 699 { _qosValue = qos_value; } 700 701 inline MasterID masterId() const { return req->masterId(); } 702 703 // Network error conditions... encapsulate them as methods since 704 // their encoding keeps changing (from result field to command 705 // field, etc.) 706 void 707 setBadAddress() 708 { 709 assert(isResponse()); 710 cmd = MemCmd::BadAddressError; 711 } 712 713 void copyError(Packet *pkt) { assert(pkt->isError()); cmd = pkt->cmd; } 714 715 Addr getAddr() const { assert(flags.isSet(VALID_ADDR)); return addr; } 716 /** 717 * Update the address of this packet mid-transaction. This is used 718 * by the address mapper to change an already set address to a new 719 * one based on the system configuration. It is intended to remap 720 * an existing address, so it asserts that the current address is 721 * valid. 722 */ 723 void setAddr(Addr _addr) { assert(flags.isSet(VALID_ADDR)); addr = _addr; } 724 725 unsigned getSize() const { assert(flags.isSet(VALID_SIZE)); return size; } 726 727 Addr getOffset(unsigned int blk_size) const 728 { 729 return getAddr() & Addr(blk_size - 1); 730 } 731 732 Addr getBlockAddr(unsigned int blk_size) const 733 { 734 return getAddr() & ~(Addr(blk_size - 1)); 735 } 736 737 bool isSecure() const 738 { 739 assert(flags.isSet(VALID_ADDR)); 740 return _isSecure; 741 } 742 743 /** 744 * Accessor function to atomic op. 745 */ 746 AtomicOpFunctor *getAtomicOp() const { return req->getAtomicOpFunctor(); } 747 bool isAtomicOp() const { return req->isAtomic(); } 748 749 /** 750 * It has been determined that the SC packet should successfully update 751 * memory. Therefore, convert this SC packet to a normal write. 752 */ 753 void 754 convertScToWrite() 755 { 756 assert(isLLSC()); 757 assert(isWrite()); 758 cmd = MemCmd::WriteReq; 759 } 760 761 /** 762 * When ruby is in use, Ruby will monitor the cache line and the 763 * phys memory should treat LL ops as normal reads. 764 */ 765 void 766 convertLlToRead() 767 { 768 assert(isLLSC()); 769 assert(isRead()); 770 cmd = MemCmd::ReadReq; 771 } 772 773 /** 774 * Constructor. Note that a Request object must be constructed 775 * first, but the Requests's physical address and size fields need 776 * not be valid. The command must be supplied. 777 */ 778 Packet(const RequestPtr &_req, MemCmd _cmd) 779 : cmd(_cmd), id((PacketId)_req.get()), req(_req), 780 data(nullptr), addr(0), _isSecure(false), size(0), 781 _qosValue(0), headerDelay(0), snoopDelay(0), 782 payloadDelay(0), senderState(NULL) 783 { 784 if (req->hasPaddr()) { 785 addr = req->getPaddr(); 786 flags.set(VALID_ADDR); 787 _isSecure = req->isSecure(); 788 } 789 if (req->hasSize()) { 790 size = req->getSize(); 791 flags.set(VALID_SIZE); 792 } 793 } 794 795 /** 796 * Alternate constructor if you are trying to create a packet with 797 * a request that is for a whole block, not the address from the 798 * req. this allows for overriding the size/addr of the req. 799 */ 800 Packet(const RequestPtr &_req, MemCmd _cmd, int _blkSize, PacketId _id = 0) 801 : cmd(_cmd), id(_id ? _id : (PacketId)_req.get()), req(_req), 802 data(nullptr), addr(0), _isSecure(false), 803 _qosValue(0), headerDelay(0), 804 snoopDelay(0), payloadDelay(0), senderState(NULL) 805 { 806 if (req->hasPaddr()) { 807 addr = req->getPaddr() & ~(_blkSize - 1); 808 flags.set(VALID_ADDR); 809 _isSecure = req->isSecure(); 810 } 811 size = _blkSize; 812 flags.set(VALID_SIZE); 813 } 814 815 /** 816 * Alternate constructor for copying a packet. Copy all fields 817 * *except* if the original packet's data was dynamic, don't copy 818 * that, as we can't guarantee that the new packet's lifetime is 819 * less than that of the original packet. In this case the new 820 * packet should allocate its own data. 821 */ 822 Packet(const PacketPtr pkt, bool clear_flags, bool alloc_data) 823 : cmd(pkt->cmd), id(pkt->id), req(pkt->req), 824 data(nullptr), 825 addr(pkt->addr), _isSecure(pkt->_isSecure), size(pkt->size), 826 bytesValid(pkt->bytesValid), 827 _qosValue(pkt->qosValue()), 828 headerDelay(pkt->headerDelay), 829 snoopDelay(0), 830 payloadDelay(pkt->payloadDelay), 831 senderState(pkt->senderState) 832 { 833 if (!clear_flags) 834 flags.set(pkt->flags & COPY_FLAGS); 835 836 flags.set(pkt->flags & (VALID_ADDR|VALID_SIZE)); 837 838 // should we allocate space for data, or not, the express 839 // snoops do not need to carry any data as they only serve to 840 // co-ordinate state changes 841 if (alloc_data) { 842 // even if asked to allocate data, if the original packet 843 // holds static data, then the sender will not be doing 844 // any memcpy on receiving the response, thus we simply 845 // carry the pointer forward 846 if (pkt->flags.isSet(STATIC_DATA)) { 847 data = pkt->data; 848 flags.set(STATIC_DATA); 849 } else { 850 allocate(); 851 } 852 } 853 } 854 855 /** 856 * Generate the appropriate read MemCmd based on the Request flags. 857 */ 858 static MemCmd 859 makeReadCmd(const RequestPtr &req) 860 { 861 if (req->isLLSC()) 862 return MemCmd::LoadLockedReq; 863 else if (req->isPrefetchEx()) 864 return MemCmd::SoftPFExReq; 865 else if (req->isPrefetch()) 866 return MemCmd::SoftPFReq; 867 else 868 return MemCmd::ReadReq; 869 } 870 871 /** 872 * Generate the appropriate write MemCmd based on the Request flags. 873 */ 874 static MemCmd 875 makeWriteCmd(const RequestPtr &req) 876 { 877 if (req->isLLSC()) 878 return MemCmd::StoreCondReq; 879 else if (req->isSwap() || req->isAtomic()) 880 return MemCmd::SwapReq; 881 else if (req->isCacheInvalidate()) { 882 return req->isCacheClean() ? MemCmd::CleanInvalidReq : 883 MemCmd::InvalidateReq; 884 } else if (req->isCacheClean()) { 885 return MemCmd::CleanSharedReq; 886 } else 887 return MemCmd::WriteReq; 888 } 889 890 /** 891 * Constructor-like methods that return Packets based on Request objects. 892 * Fine-tune the MemCmd type if it's not a vanilla read or write. 893 */ 894 static PacketPtr 895 createRead(const RequestPtr &req) 896 { 897 return new Packet(req, makeReadCmd(req)); 898 } 899 900 static PacketPtr 901 createWrite(const RequestPtr &req) 902 { 903 return new Packet(req, makeWriteCmd(req)); 904 } 905 906 /** 907 * clean up packet variables 908 */ 909 ~Packet() 910 { 911 deleteData(); 912 } 913 914 /** 915 * Take a request packet and modify it in place to be suitable for 916 * returning as a response to that request. 917 */ 918 void 919 makeResponse() 920 { 921 assert(needsResponse()); 922 assert(isRequest()); 923 cmd = cmd.responseCommand(); 924 925 // responses are never express, even if the snoop that 926 // triggered them was 927 flags.clear(EXPRESS_SNOOP); 928 } 929 930 void 931 makeAtomicResponse() 932 { 933 makeResponse(); 934 } 935 936 void 937 makeTimingResponse() 938 { 939 makeResponse(); 940 } 941 942 void 943 setFunctionalResponseStatus(bool success) 944 { 945 if (!success) { 946 if (isWrite()) { 947 cmd = MemCmd::FunctionalWriteError; 948 } else { 949 cmd = MemCmd::FunctionalReadError; 950 } 951 } 952 } 953 954 void 955 setSize(unsigned size) 956 { 957 assert(!flags.isSet(VALID_SIZE)); 958 959 this->size = size; 960 flags.set(VALID_SIZE); 961 } 962 963 964 public: 965 /** 966 * @{ 967 * @name Data accessor mehtods 968 */ 969 970 /** 971 * Set the data pointer to the following value that should not be 972 * freed. Static data allows us to do a single memcpy even if 973 * multiple packets are required to get from source to destination 974 * and back. In essence the pointer is set calling dataStatic on 975 * the original packet, and whenever this packet is copied and 976 * forwarded the same pointer is passed on. When a packet 977 * eventually reaches the destination holding the data, it is 978 * copied once into the location originally set. On the way back 979 * to the source, no copies are necessary. 980 */ 981 template <typename T> 982 void 983 dataStatic(T *p) 984 { 985 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 986 data = (PacketDataPtr)p; 987 flags.set(STATIC_DATA); 988 } 989 990 /** 991 * Set the data pointer to the following value that should not be 992 * freed. This version of the function allows the pointer passed 993 * to us to be const. To avoid issues down the line we cast the 994 * constness away, the alternative would be to keep both a const 995 * and non-const data pointer and cleverly choose between 996 * them. Note that this is only allowed for static data. 997 */ 998 template <typename T> 999 void 1000 dataStaticConst(const T *p) 1001 { 1002 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 1003 data = const_cast<PacketDataPtr>(p); 1004 flags.set(STATIC_DATA); 1005 } 1006 1007 /** 1008 * Set the data pointer to a value that should have delete [] 1009 * called on it. Dynamic data is local to this packet, and as the 1010 * packet travels from source to destination, forwarded packets 1011 * will allocate their own data. When a packet reaches the final 1012 * destination it will populate the dynamic data of that specific 1013 * packet, and on the way back towards the source, memcpy will be 1014 * invoked in every step where a new packet was created e.g. in 1015 * the caches. Ultimately when the response reaches the source a 1016 * final memcpy is needed to extract the data from the packet 1017 * before it is deallocated. 1018 */ 1019 template <typename T> 1020 void 1021 dataDynamic(T *p) 1022 { 1023 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 1024 data = (PacketDataPtr)p; 1025 flags.set(DYNAMIC_DATA); 1026 } 1027 1028 /** 1029 * get a pointer to the data ptr. 1030 */ 1031 template <typename T> 1032 T* 1033 getPtr() 1034 { 1035 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA)); 1036 return (T*)data; 1037 } 1038 1039 template <typename T> 1040 const T* 1041 getConstPtr() const 1042 { 1043 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA)); 1044 return (const T*)data; 1045 } 1046 1047 /** 1048 * Get the data in the packet byte swapped from big endian to 1049 * host endian. 1050 */ 1051 template <typename T> 1052 T getBE() const; 1053 1054 /** 1055 * Get the data in the packet byte swapped from little endian to 1056 * host endian. 1057 */ 1058 template <typename T> 1059 T getLE() const; 1060 1061 /** 1062 * Get the data in the packet byte swapped from the specified 1063 * endianness. 1064 */ 1065 template <typename T> 1066 T get(ByteOrder endian) const; 1067 1068#if THE_ISA != NULL_ISA 1069 /** 1070 * Get the data in the packet byte swapped from guest to host 1071 * endian. 1072 */ 1073 template <typename T> 1074 T get() const 1075 M5_DEPRECATED_MSG("The memory system should be ISA independent."); 1076#endif 1077 1078 /** Set the value in the data pointer to v as big endian. */ 1079 template <typename T> 1080 void setBE(T v); 1081 1082 /** Set the value in the data pointer to v as little endian. */ 1083 template <typename T> 1084 void setLE(T v); 1085 1086 /** 1087 * Set the value in the data pointer to v using the specified 1088 * endianness. 1089 */ 1090 template <typename T> 1091 void set(T v, ByteOrder endian); 1092 1093#if THE_ISA != NULL_ISA 1094 /** Set the value in the data pointer to v as guest endian. */ 1095 template <typename T> 1096 void set(T v) 1097 M5_DEPRECATED_MSG("The memory system should be ISA independent."); 1098#endif 1099 1100 /** 1101 * Get the data in the packet byte swapped from the specified 1102 * endianness and zero-extended to 64 bits. 1103 */ 1104 uint64_t getUintX(ByteOrder endian) const; 1105 1106 /** 1107 * Set the value in the word w after truncating it to the length 1108 * of the packet and then byteswapping it to the desired 1109 * endianness. 1110 */ 1111 void setUintX(uint64_t w, ByteOrder endian); 1112 1113 /** 1114 * Copy data into the packet from the provided pointer. 1115 */ 1116 void 1117 setData(const uint8_t *p) 1118 { 1119 // we should never be copying data onto itself, which means we 1120 // must idenfity packets with static data, as they carry the 1121 // same pointer from source to destination and back 1122 assert(p != getPtr<uint8_t>() || flags.isSet(STATIC_DATA)); 1123 1124 if (p != getPtr<uint8_t>()) 1125 // for packet with allocated dynamic data, we copy data from 1126 // one to the other, e.g. a forwarded response to a response 1127 std::memcpy(getPtr<uint8_t>(), p, getSize()); 1128 } 1129 1130 /** 1131 * Copy data into the packet from the provided block pointer, 1132 * which is aligned to the given block size. 1133 */ 1134 void 1135 setDataFromBlock(const uint8_t *blk_data, int blkSize) 1136 { 1137 setData(blk_data + getOffset(blkSize)); 1138 } 1139 1140 /** 1141 * Copy data from the packet to the memory at the provided pointer. 1142 * @param p Pointer to which data will be copied. 1143 */ 1144 void 1145 writeData(uint8_t *p) const 1146 { 1147 std::memcpy(p, getConstPtr<uint8_t>(), getSize()); 1148 } 1149 1150 /** 1151 * Copy data from the packet to the provided block pointer, which 1152 * is aligned to the given block size. 1153 * @param blk_data Pointer to block to which data will be copied. 1154 * @param blkSize Block size in bytes. 1155 */ 1156 void 1157 writeDataToBlock(uint8_t *blk_data, int blkSize) const 1158 { 1159 writeData(blk_data + getOffset(blkSize)); 1160 } 1161 1162 /** 1163 * delete the data pointed to in the data pointer. Ok to call to 1164 * matter how data was allocted. 1165 */ 1166 void 1167 deleteData() 1168 { 1169 if (flags.isSet(DYNAMIC_DATA)) 1170 delete [] data; 1171 1172 flags.clear(STATIC_DATA|DYNAMIC_DATA); 1173 data = NULL; 1174 } 1175 1176 /** Allocate memory for the packet. */ 1177 void 1178 allocate() 1179 { 1180 // if either this command or the response command has a data 1181 // payload, actually allocate space 1182 if (hasData() || hasRespData()) { 1183 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 1184 flags.set(DYNAMIC_DATA); 1185 data = new uint8_t[getSize()]; 1186 } 1187 } 1188 1189 /** @} */ 1190 1191 /** Get the data in the packet without byte swapping. */ 1192 template <typename T> 1193 T getRaw() const; 1194 1195 /** Set the value in the data pointer to v without byte swapping. */ 1196 template <typename T> 1197 void setRaw(T v); 1198 1199 public: 1200 /** 1201 * Check a functional request against a memory value stored in 1202 * another packet (i.e. an in-transit request or 1203 * response). Returns true if the current packet is a read, and 1204 * the other packet provides the data, which is then copied to the 1205 * current packet. If the current packet is a write, and the other 1206 * packet intersects this one, then we update the data 1207 * accordingly. 1208 */ 1209 bool 1210 trySatisfyFunctional(PacketPtr other) 1211 { 1212 // all packets that are carrying a payload should have a valid 1213 // data pointer 1214 return trySatisfyFunctional(other, other->getAddr(), other->isSecure(), 1215 other->getSize(), 1216 other->hasData() ? 1217 other->getPtr<uint8_t>() : NULL); 1218 } 1219 1220 /** 1221 * Does the request need to check for cached copies of the same block 1222 * in the memory hierarchy above. 1223 **/ 1224 bool 1225 mustCheckAbove() const 1226 { 1227 return cmd == MemCmd::HardPFReq || isEviction(); 1228 } 1229 1230 /** 1231 * Is this packet a clean eviction, including both actual clean 1232 * evict packets, but also clean writebacks. 1233 */ 1234 bool 1235 isCleanEviction() const 1236 { 1237 return cmd == MemCmd::CleanEvict || cmd == MemCmd::WritebackClean; 1238 } 1239 1240 /** 1241 * Check a functional request against a memory value represented 1242 * by a base/size pair and an associated data array. If the 1243 * current packet is a read, it may be satisfied by the memory 1244 * value. If the current packet is a write, it may update the 1245 * memory value. 1246 */ 1247 bool 1248 trySatisfyFunctional(Printable *obj, Addr base, bool is_secure, int size, 1249 uint8_t *_data); 1250 1251 /** 1252 * Push label for PrintReq (safe to call unconditionally). 1253 */ 1254 void 1255 pushLabel(const std::string &lbl) 1256 { 1257 if (isPrint()) 1258 safe_cast<PrintReqState*>(senderState)->pushLabel(lbl); 1259 } 1260 1261 /** 1262 * Pop label for PrintReq (safe to call unconditionally). 1263 */ 1264 void 1265 popLabel() 1266 { 1267 if (isPrint()) 1268 safe_cast<PrintReqState*>(senderState)->popLabel(); 1269 } 1270 1271 void print(std::ostream &o, int verbosity = 0, 1272 const std::string &prefix = "") const; 1273 1274 /** 1275 * A no-args wrapper of print(std::ostream...) 1276 * meant to be invoked from DPRINTFs 1277 * avoiding string overheads in fast mode 1278 * @return string with the request's type and start<->end addresses 1279 */ 1280 std::string print() const; 1281}; 1282 1283#endif //__MEM_PACKET_HH 1284