packet.hh revision 10583
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 * Source port identifier set on a request packet to enable 300 * appropriate routing of the responses. The source port 301 * identifier is set by any multiplexing component, e.g. a 302 * crossbar, as the timing responses need this information to be 303 * routed back to the appropriate port at a later point in 304 * time. The field can be updated (over-written) as the request 305 * packet passes through additional multiplexing components, and 306 * it is their responsibility to remember the original source port 307 * identifier, for example by using an appropriate sender 308 * state. The latter is done in the cache and bridge. 309 */ 310 PortID src; 311 312 /** 313 * Destination port identifier that is present on all response 314 * packets that passed through a multiplexing component as a 315 * request packet. The source port identifier is turned into a 316 * destination port identifier when the packet is turned into a 317 * response, and the destination is used, e.g. by the crossbar, to 318 * select the appropriate path through the interconnect. 319 */ 320 PortID dest; 321 322 /** 323 * The original value of the command field. Only valid when the 324 * current command field is an error condition; in that case, the 325 * previous contents of the command field are copied here. This 326 * field is *not* set on non-error responses. 327 */ 328 MemCmd origCmd; 329 330 /** 331 * These values specify the range of bytes found that satisfy a 332 * functional read. 333 */ 334 uint16_t bytesValidStart; 335 uint16_t bytesValidEnd; 336 337 public: 338 339 /** 340 * The extra delay from seeing the packet until the first word is 341 * transmitted. This delay is used to communicate the crossbar 342 * forwarding latency to the neighbouring object (e.g. a cache) 343 * that actually makes the packet wait. As the delay is relative, 344 * a 32-bit unsigned should be sufficient. 345 */ 346 uint32_t firstWordDelay; 347 348 /** 349 * The extra pipelining delay from seeing the packet until the 350 * last word is transmitted by the component that provided it (if 351 * any). This includes the first word delay. Similar to the first 352 * word delay, this is used to make up for the fact that the 353 * crossbar does not make the packet wait. As the delay is 354 * relative, a 32-bit unsigned should be sufficient. 355 */ 356 uint32_t lastWordDelay; 357 358 /** 359 * A virtual base opaque structure used to hold state associated 360 * with the packet (e.g., an MSHR), specific to a MemObject that 361 * sees the packet. A pointer to this state is returned in the 362 * packet's response so that the MemObject in question can quickly 363 * look up the state needed to process it. A specific subclass 364 * would be derived from this to carry state specific to a 365 * particular sending device. 366 * 367 * As multiple MemObjects may add their SenderState throughout the 368 * memory system, the SenderStates create a stack, where a 369 * MemObject can add a new Senderstate, as long as the 370 * predecessing SenderState is restored when the response comes 371 * back. For this reason, the predecessor should always be 372 * populated with the current SenderState of a packet before 373 * modifying the senderState field in the request packet. 374 */ 375 struct SenderState 376 { 377 SenderState* predecessor; 378 SenderState() : predecessor(NULL) {} 379 virtual ~SenderState() {} 380 }; 381 382 /** 383 * Object used to maintain state of a PrintReq. The senderState 384 * field of a PrintReq should always be of this type. 385 */ 386 class PrintReqState : public SenderState 387 { 388 private: 389 /** 390 * An entry in the label stack. 391 */ 392 struct LabelStackEntry 393 { 394 const std::string label; 395 std::string *prefix; 396 bool labelPrinted; 397 LabelStackEntry(const std::string &_label, std::string *_prefix); 398 }; 399 400 typedef std::list<LabelStackEntry> LabelStack; 401 LabelStack labelStack; 402 403 std::string *curPrefixPtr; 404 405 public: 406 std::ostream &os; 407 const int verbosity; 408 409 PrintReqState(std::ostream &os, int verbosity = 0); 410 ~PrintReqState(); 411 412 /** 413 * Returns the current line prefix. 414 */ 415 const std::string &curPrefix() { return *curPrefixPtr; } 416 417 /** 418 * Push a label onto the label stack, and prepend the given 419 * prefix string onto the current prefix. Labels will only be 420 * printed if an object within the label's scope is printed. 421 */ 422 void pushLabel(const std::string &lbl, 423 const std::string &prefix = " "); 424 425 /** 426 * Pop a label off the label stack. 427 */ 428 void popLabel(); 429 430 /** 431 * Print all of the pending unprinted labels on the 432 * stack. Called by printObj(), so normally not called by 433 * users unless bypassing printObj(). 434 */ 435 void printLabels(); 436 437 /** 438 * Print a Printable object to os, because it matched the 439 * address on a PrintReq. 440 */ 441 void printObj(Printable *obj); 442 }; 443 444 /** 445 * This packet's sender state. Devices should use dynamic_cast<> 446 * to cast to the state appropriate to the sender. The intent of 447 * this variable is to allow a device to attach extra information 448 * to a request. A response packet must return the sender state 449 * that was attached to the original request (even if a new packet 450 * is created). 451 */ 452 SenderState *senderState; 453 454 /** 455 * Push a new sender state to the packet and make the current 456 * sender state the predecessor of the new one. This should be 457 * prefered over direct manipulation of the senderState member 458 * variable. 459 * 460 * @param sender_state SenderState to push at the top of the stack 461 */ 462 void pushSenderState(SenderState *sender_state); 463 464 /** 465 * Pop the top of the state stack and return a pointer to it. This 466 * assumes the current sender state is not NULL. This should be 467 * preferred over direct manipulation of the senderState member 468 * variable. 469 * 470 * @return The current top of the stack 471 */ 472 SenderState *popSenderState(); 473 474 /** 475 * Go through the sender state stack and return the first instance 476 * that is of type T (as determined by a dynamic_cast). If there 477 * is no sender state of type T, NULL is returned. 478 * 479 * @return The topmost state of type T 480 */ 481 template <typename T> 482 T * findNextSenderState() const 483 { 484 T *t = NULL; 485 SenderState* sender_state = senderState; 486 while (t == NULL && sender_state != NULL) { 487 t = dynamic_cast<T*>(sender_state); 488 sender_state = sender_state->predecessor; 489 } 490 return t; 491 } 492 493 /// Return the string name of the cmd field (for debugging and 494 /// tracing). 495 const std::string &cmdString() const { return cmd.toString(); } 496 497 /// Return the index of this command. 498 inline int cmdToIndex() const { return cmd.toInt(); } 499 500 bool isRead() const { return cmd.isRead(); } 501 bool isWrite() const { return cmd.isWrite(); } 502 bool isUpgrade() const { return cmd.isUpgrade(); } 503 bool isRequest() const { return cmd.isRequest(); } 504 bool isResponse() const { return cmd.isResponse(); } 505 bool needsExclusive() const { return cmd.needsExclusive(); } 506 bool needsResponse() const { return cmd.needsResponse(); } 507 bool isInvalidate() const { return cmd.isInvalidate(); } 508 bool isWriteInvalidate() const { return cmd.isWriteInvalidate(); } 509 bool hasData() const { return cmd.hasData(); } 510 bool isLLSC() const { return cmd.isLLSC(); } 511 bool isError() const { return cmd.isError(); } 512 bool isPrint() const { return cmd.isPrint(); } 513 bool isFlush() const { return cmd.isFlush(); } 514 515 // Snoop flags 516 void assertMemInhibit() 517 { 518 assert(isRequest()); 519 assert(!flags.isSet(MEM_INHIBIT)); 520 flags.set(MEM_INHIBIT); 521 } 522 bool memInhibitAsserted() const { return flags.isSet(MEM_INHIBIT); } 523 void assertShared() { flags.set(SHARED); } 524 bool sharedAsserted() const { return flags.isSet(SHARED); } 525 526 // Special control flags 527 void setExpressSnoop() { flags.set(EXPRESS_SNOOP); } 528 bool isExpressSnoop() const { return flags.isSet(EXPRESS_SNOOP); } 529 void setSupplyExclusive() { flags.set(SUPPLY_EXCLUSIVE); } 530 void clearSupplyExclusive() { flags.clear(SUPPLY_EXCLUSIVE); } 531 bool isSupplyExclusive() const { return flags.isSet(SUPPLY_EXCLUSIVE); } 532 void setSuppressFuncError() { flags.set(SUPPRESS_FUNC_ERROR); } 533 bool suppressFuncError() const { return flags.isSet(SUPPRESS_FUNC_ERROR); } 534 void setPrefetchSquashed() { flags.set(PREFETCH_SNOOP_SQUASH); } 535 bool prefetchSquashed() const { return flags.isSet(PREFETCH_SNOOP_SQUASH); } 536 537 // Network error conditions... encapsulate them as methods since 538 // their encoding keeps changing (from result field to command 539 // field, etc.) 540 void 541 setBadAddress() 542 { 543 assert(isResponse()); 544 cmd = MemCmd::BadAddressError; 545 } 546 547 bool hadBadAddress() const { return cmd == MemCmd::BadAddressError; } 548 void copyError(Packet *pkt) { assert(pkt->isError()); cmd = pkt->cmd; } 549 550 /// Accessor function to get the source index of the packet. 551 PortID getSrc() const { return src; } 552 /// Accessor function to set the source index of the packet. 553 void setSrc(PortID _src) { src = _src; } 554 555 /// Accessor function for the destination index of the packet. 556 PortID getDest() const { return dest; } 557 /// Accessor function to set the destination index of the packet. 558 void setDest(PortID _dest) { dest = _dest; } 559 /// Reset destination field, e.g. to turn a response into a request again. 560 void clearDest() { dest = InvalidPortID; } 561 562 Addr getAddr() const { assert(flags.isSet(VALID_ADDR)); return addr; } 563 /** 564 * Update the address of this packet mid-transaction. This is used 565 * by the address mapper to change an already set address to a new 566 * one based on the system configuration. It is intended to remap 567 * an existing address, so it asserts that the current address is 568 * valid. 569 */ 570 void setAddr(Addr _addr) { assert(flags.isSet(VALID_ADDR)); addr = _addr; } 571 572 unsigned getSize() const { assert(flags.isSet(VALID_SIZE)); return size; } 573 Addr getOffset(int blkSize) const { return getAddr() & (Addr)(blkSize - 1); } 574 575 bool isSecure() const 576 { 577 assert(flags.isSet(VALID_ADDR)); 578 return _isSecure; 579 } 580 581 /** 582 * It has been determined that the SC packet should successfully update 583 * memory. Therefore, convert this SC packet to a normal write. 584 */ 585 void 586 convertScToWrite() 587 { 588 assert(isLLSC()); 589 assert(isWrite()); 590 cmd = MemCmd::WriteReq; 591 } 592 593 /** 594 * When ruby is in use, Ruby will monitor the cache line and thus M5 595 * phys memory should treat LL ops as normal reads. 596 */ 597 void 598 convertLlToRead() 599 { 600 assert(isLLSC()); 601 assert(isRead()); 602 cmd = MemCmd::ReadReq; 603 } 604 605 /** 606 * Constructor. Note that a Request object must be constructed 607 * first, but the Requests's physical address and size fields need 608 * not be valid. The command must be supplied. 609 */ 610 Packet(const RequestPtr _req, MemCmd _cmd) 611 : cmd(_cmd), req(_req), data(nullptr), addr(0), _isSecure(false), 612 size(0), src(InvalidPortID), dest(InvalidPortID), 613 bytesValidStart(0), bytesValidEnd(0), 614 firstWordDelay(0), lastWordDelay(0), 615 senderState(NULL) 616 { 617 if (req->hasPaddr()) { 618 addr = req->getPaddr(); 619 flags.set(VALID_ADDR); 620 _isSecure = req->isSecure(); 621 } 622 if (req->hasSize()) { 623 size = req->getSize(); 624 flags.set(VALID_SIZE); 625 } 626 } 627 628 /** 629 * Alternate constructor if you are trying to create a packet with 630 * a request that is for a whole block, not the address from the 631 * req. this allows for overriding the size/addr of the req. 632 */ 633 Packet(const RequestPtr _req, MemCmd _cmd, int _blkSize) 634 : cmd(_cmd), req(_req), data(nullptr), addr(0), _isSecure(false), 635 src(InvalidPortID), dest(InvalidPortID), 636 bytesValidStart(0), bytesValidEnd(0), 637 firstWordDelay(0), lastWordDelay(0), 638 senderState(NULL) 639 { 640 if (req->hasPaddr()) { 641 addr = req->getPaddr() & ~(_blkSize - 1); 642 flags.set(VALID_ADDR); 643 _isSecure = req->isSecure(); 644 } 645 size = _blkSize; 646 flags.set(VALID_SIZE); 647 } 648 649 /** 650 * Alternate constructor for copying a packet. Copy all fields 651 * *except* if the original packet's data was dynamic, don't copy 652 * that, as we can't guarantee that the new packet's lifetime is 653 * less than that of the original packet. In this case the new 654 * packet should allocate its own data. 655 */ 656 Packet(PacketPtr pkt, bool clear_flags, bool alloc_data) 657 : cmd(pkt->cmd), req(pkt->req), 658 data(nullptr), 659 addr(pkt->addr), _isSecure(pkt->_isSecure), size(pkt->size), 660 src(pkt->src), dest(pkt->dest), 661 bytesValidStart(pkt->bytesValidStart), 662 bytesValidEnd(pkt->bytesValidEnd), 663 firstWordDelay(pkt->firstWordDelay), 664 lastWordDelay(pkt->lastWordDelay), 665 senderState(pkt->senderState) 666 { 667 if (!clear_flags) 668 flags.set(pkt->flags & COPY_FLAGS); 669 670 flags.set(pkt->flags & (VALID_ADDR|VALID_SIZE)); 671 672 // should we allocate space for data, or not, the express 673 // snoops do not need to carry any data as they only serve to 674 // co-ordinate state changes 675 if (alloc_data) { 676 // even if asked to allocate data, if the original packet 677 // holds static data, then the sender will not be doing 678 // any memcpy on receiving the response, thus we simply 679 // carry the pointer forward 680 if (pkt->flags.isSet(STATIC_DATA)) { 681 data = pkt->data; 682 flags.set(STATIC_DATA); 683 } else { 684 allocate(); 685 } 686 } 687 } 688 689 /** 690 * Change the packet type based on request type. 691 */ 692 void 693 refineCommand() 694 { 695 if (cmd == MemCmd::ReadReq) { 696 if (req->isLLSC()) { 697 cmd = MemCmd::LoadLockedReq; 698 } else if (req->isPrefetch()) { 699 cmd = MemCmd::SoftPFReq; 700 } 701 } else if (cmd == MemCmd::WriteReq) { 702 if (req->isLLSC()) { 703 cmd = MemCmd::StoreCondReq; 704 } else if (req->isSwap()) { 705 cmd = MemCmd::SwapReq; 706 } 707 } 708 } 709 710 /** 711 * Constructor-like methods that return Packets based on Request objects. 712 * Will call refineCommand() to fine-tune the Packet type if it's not a 713 * vanilla read or write. 714 */ 715 static PacketPtr 716 createRead(const RequestPtr req) 717 { 718 PacketPtr pkt = new Packet(req, MemCmd::ReadReq); 719 pkt->refineCommand(); 720 return pkt; 721 } 722 723 static PacketPtr 724 createWrite(const RequestPtr req) 725 { 726 PacketPtr pkt = new Packet(req, MemCmd::WriteReq); 727 pkt->refineCommand(); 728 return pkt; 729 } 730 731 /** 732 * clean up packet variables 733 */ 734 ~Packet() 735 { 736 // If this is a request packet for which there's no response, 737 // delete the request object here, since the requester will 738 // never get the chance. 739 if (req && isRequest() && !needsResponse()) 740 delete req; 741 deleteData(); 742 } 743 744 /** 745 * Take a request packet and modify it in place to be suitable for 746 * returning as a response to that request. The source field is 747 * turned into the destination, and subsequently cleared. Note 748 * that the latter is not necessary for atomic requests, but 749 * causes no harm as neither field is valid. 750 */ 751 void 752 makeResponse() 753 { 754 assert(needsResponse()); 755 assert(isRequest()); 756 origCmd = cmd; 757 cmd = cmd.responseCommand(); 758 759 // responses are never express, even if the snoop that 760 // triggered them was 761 flags.clear(EXPRESS_SNOOP); 762 763 dest = src; 764 src = InvalidPortID; 765 } 766 767 void 768 makeAtomicResponse() 769 { 770 makeResponse(); 771 } 772 773 void 774 makeTimingResponse() 775 { 776 makeResponse(); 777 } 778 779 void 780 setFunctionalResponseStatus(bool success) 781 { 782 if (!success) { 783 if (isWrite()) { 784 cmd = MemCmd::FunctionalWriteError; 785 } else { 786 cmd = MemCmd::FunctionalReadError; 787 } 788 } 789 } 790 791 void 792 setSize(unsigned size) 793 { 794 assert(!flags.isSet(VALID_SIZE)); 795 796 this->size = size; 797 flags.set(VALID_SIZE); 798 } 799 800 801 /** 802 * Set the data pointer to the following value that should not be 803 * freed. Static data allows us to do a single memcpy even if 804 * multiple packets are required to get from source to destination 805 * and back. In essence the pointer is set calling dataStatic on 806 * the original packet, and whenever this packet is copied and 807 * forwarded the same pointer is passed on. When a packet 808 * eventually reaches the destination holding the data, it is 809 * copied once into the location originally set. On the way back 810 * to the source, no copies are necessary. 811 */ 812 template <typename T> 813 void 814 dataStatic(T *p) 815 { 816 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 817 data = (PacketDataPtr)p; 818 flags.set(STATIC_DATA); 819 } 820 821 /** 822 * Set the data pointer to the following value that should not be 823 * freed. This version of the function allows the pointer passed 824 * to us to be const. To avoid issues down the line we cast the 825 * constness away, the alternative would be to keep both a const 826 * and non-const data pointer and cleverly choose between 827 * them. Note that this is only allowed for static data. 828 */ 829 template <typename T> 830 void 831 dataStaticConst(const T *p) 832 { 833 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 834 data = const_cast<PacketDataPtr>(p); 835 flags.set(STATIC_DATA); 836 } 837 838 /** 839 * Set the data pointer to a value that should have delete [] 840 * called on it. Dynamic data is local to this packet, and as the 841 * packet travels from source to destination, forwarded packets 842 * will allocate their own data. When a packet reaches the final 843 * destination it will populate the dynamic data of that specific 844 * packet, and on the way back towards the source, memcpy will be 845 * invoked in every step where a new packet was created e.g. in 846 * the caches. Ultimately when the response reaches the source a 847 * final memcpy is needed to extract the data from the packet 848 * before it is deallocated. 849 */ 850 template <typename T> 851 void 852 dataDynamic(T *p) 853 { 854 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 855 data = (PacketDataPtr)p; 856 flags.set(DYNAMIC_DATA); 857 } 858 859 /** 860 * get a pointer to the data ptr. 861 */ 862 template <typename T> 863 T* 864 getPtr() 865 { 866 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA)); 867 return (T*)data; 868 } 869 870 template <typename T> 871 const T* 872 getConstPtr() const 873 { 874 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA)); 875 return (const T*)data; 876 } 877 878 /** 879 * return the value of what is pointed to in the packet. 880 */ 881 template <typename T> 882 T get() const; 883 884 /** 885 * set the value in the data pointer to v. 886 */ 887 template <typename T> 888 void set(T v); 889 890 /** 891 * Copy data into the packet from the provided pointer. 892 */ 893 void 894 setData(const uint8_t *p) 895 { 896 // we should never be copying data onto itself, which means we 897 // must idenfity packets with static data, as they carry the 898 // same pointer from source to destination and back 899 assert(p != getPtr<uint8_t>() || flags.isSet(STATIC_DATA)); 900 901 if (p != getPtr<uint8_t>()) 902 // for packet with allocated dynamic data, we copy data from 903 // one to the other, e.g. a forwarded response to a response 904 std::memcpy(getPtr<uint8_t>(), p, getSize()); 905 } 906 907 /** 908 * Copy data into the packet from the provided block pointer, 909 * which is aligned to the given block size. 910 */ 911 void 912 setDataFromBlock(const uint8_t *blk_data, int blkSize) 913 { 914 setData(blk_data + getOffset(blkSize)); 915 } 916 917 /** 918 * Copy data from the packet to the provided block pointer, which 919 * is aligned to the given block size. 920 */ 921 void 922 writeData(uint8_t *p) const 923 { 924 std::memcpy(p, getConstPtr<uint8_t>(), getSize()); 925 } 926 927 /** 928 * Copy data from the packet to the memory at the provided pointer. 929 */ 930 void 931 writeDataToBlock(uint8_t *blk_data, int blkSize) const 932 { 933 writeData(blk_data + getOffset(blkSize)); 934 } 935 936 /** 937 * delete the data pointed to in the data pointer. Ok to call to 938 * matter how data was allocted. 939 */ 940 void 941 deleteData() 942 { 943 if (flags.isSet(DYNAMIC_DATA)) 944 delete [] data; 945 946 flags.clear(STATIC_DATA|DYNAMIC_DATA); 947 data = NULL; 948 } 949 950 /** Allocate memory for the packet. */ 951 void 952 allocate() 953 { 954 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA)); 955 flags.set(DYNAMIC_DATA); 956 data = new uint8_t[getSize()]; 957 } 958 959 /** 960 * Check a functional request against a memory value stored in 961 * another packet (i.e. an in-transit request or 962 * response). Returns true if the current packet is a read, and 963 * the other packet provides the data, which is then copied to the 964 * current packet. If the current packet is a write, and the other 965 * packet intersects this one, then we update the data 966 * accordingly. 967 */ 968 bool 969 checkFunctional(PacketPtr other) 970 { 971 // all packets that are carrying a payload should have a valid 972 // data pointer 973 return checkFunctional(other, other->getAddr(), other->isSecure(), 974 other->getSize(), 975 other->hasData() ? 976 other->getPtr<uint8_t>() : NULL); 977 } 978 979 /** 980 * Check a functional request against a memory value represented 981 * by a base/size pair and an associated data array. If the 982 * current packet is a read, it may be satisfied by the memory 983 * value. If the current packet is a write, it may update the 984 * memory value. 985 */ 986 bool 987 checkFunctional(Printable *obj, Addr base, bool is_secure, int size, 988 uint8_t *_data); 989 990 /** 991 * Push label for PrintReq (safe to call unconditionally). 992 */ 993 void 994 pushLabel(const std::string &lbl) 995 { 996 if (isPrint()) 997 safe_cast<PrintReqState*>(senderState)->pushLabel(lbl); 998 } 999 1000 /** 1001 * Pop label for PrintReq (safe to call unconditionally). 1002 */ 1003 void 1004 popLabel() 1005 { 1006 if (isPrint()) 1007 safe_cast<PrintReqState*>(senderState)->popLabel(); 1008 } 1009 1010 void print(std::ostream &o, int verbosity = 0, 1011 const std::string &prefix = "") const; 1012 1013 /** 1014 * A no-args wrapper of print(std::ostream...) 1015 * meant to be invoked from DPRINTFs 1016 * avoiding string overheads in fast mode 1017 * @return string with the request's type and start<->end addresses 1018 */ 1019 std::string print() const; 1020}; 1021 1022#endif //__MEM_PACKET_HH 1023