1/*
2 * Copyright (c) 2012-2015 ARM Limited
3 * All rights reserved
4 *
5 * The license below extends only to copyright in the software and shall
6 * not be construed as granting a license to any other intellectual
7 * property including but not limited to intellectual property relating
8 * to a hardware implementation of the functionality of the software
9 * licensed hereunder. You may use the software subject to the license
10 * terms below provided that you ensure that this notice is replicated
11 * unmodified and in its entirety in all distributions of the software,
12 * modified or unmodified, in source code or in binary form.
13 *
14 * Copyright (c) 2006 The Regents of The University of Michigan
15 * Copyright (c) 2010 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 CleanEvict,
91 SoftPFReq,
92 HardPFReq,
93 SoftPFResp,
94 HardPFResp,
95 WriteInvalidateReq,
96 WriteInvalidateResp,
97 UpgradeReq,
98 SCUpgradeReq, // Special "weak" upgrade for StoreCond
99 UpgradeResp,
100 SCUpgradeFailReq, // Failed SCUpgradeReq in MSHR (never sent)
101 UpgradeFailResp, // Valid for SCUpgradeReq only
102 ReadExReq,
103 ReadExResp,
104 ReadCleanReq,
105 ReadSharedReq,
106 LoadLockedReq,
107 StoreCondReq,
108 StoreCondFailReq, // Failed StoreCondReq in MSHR (never sent)
109 StoreCondResp,
110 SwapReq,
111 SwapResp,
112 MessageReq,
113 MessageResp,
114 // Error responses
115 // @TODO these should be classified as responses rather than
116 // requests; coding them as requests initially for backwards
117 // compatibility
118 InvalidDestError, // packet dest field invalid
119 BadAddressError, // memory address invalid
120 FunctionalReadError, // unable to fulfill functional read
121 FunctionalWriteError, // unable to fulfill functional write
122 // Fake simulator-only commands
123 PrintReq, // Print state matching address
124 FlushReq, //request for a cache flush
125 InvalidationReq, // request for address to be invalidated from lsq
126 NUM_MEM_CMDS
127 };
128
129 private:
130 /**
131 * List of command attributes.
132 */
133 enum Attribute
134 {
135 IsRead, //!< Data flows from responder to requester
136 IsWrite, //!< Data flows from requester to responder
137 IsUpgrade,
138 IsInvalidate,
139 NeedsExclusive, //!< Requires exclusive copy to complete in-cache
140 IsRequest, //!< Issued by requester
141 IsResponse, //!< Issue by responder
142 NeedsResponse, //!< Requester needs response from target
143 IsSWPrefetch,
144 IsHWPrefetch,
145 IsLlsc, //!< Alpha/MIPS LL or SC access
146 HasData, //!< There is an associated payload
147 IsError, //!< Error response
148 IsPrint, //!< Print state matching address (for debugging)
149 IsFlush, //!< Flush the address from caches
150 NUM_COMMAND_ATTRIBUTES
151 };
152
153 /**
154 * Structure that defines attributes and other data associated
155 * with a Command.
156 */
157 struct CommandInfo
158 {
159 /// Set of attribute flags.
160 const std::bitset<NUM_COMMAND_ATTRIBUTES> attributes;
161 /// Corresponding response for requests; InvalidCmd if no
162 /// response is applicable.
163 const Command response;
164 /// String representation (for printing)
165 const std::string str;
166 };
167
168 /// Array to map Command enum to associated info.
169 static const CommandInfo commandInfo[];
170
171 private:
172
173 Command cmd;
174
175 bool
176 testCmdAttrib(MemCmd::Attribute attrib) const
177 {
178 return commandInfo[cmd].attributes[attrib] != 0;
179 }
180
181 public:
182
183 bool isRead() const { return testCmdAttrib(IsRead); }
184 bool isWrite() const { return testCmdAttrib(IsWrite); }
185 bool isUpgrade() const { return testCmdAttrib(IsUpgrade); }
186 bool isRequest() const { return testCmdAttrib(IsRequest); }
187 bool isResponse() const { return testCmdAttrib(IsResponse); }
188 bool needsExclusive() const { return testCmdAttrib(NeedsExclusive); }
189 bool needsResponse() const { return testCmdAttrib(NeedsResponse); }
190 bool isInvalidate() const { return testCmdAttrib(IsInvalidate); }
191 bool isWriteInvalidate() const { return testCmdAttrib(IsWrite) &&
192 testCmdAttrib(IsInvalidate); }
193
194 /**
195 * Check if this particular packet type carries payload data. Note
196 * that this does not reflect if the data pointer of the packet is
197 * valid or not.
198 */
199 bool hasData() const { return testCmdAttrib(HasData); }
200 bool isLLSC() const { return testCmdAttrib(IsLlsc); }
201 bool isSWPrefetch() const { return testCmdAttrib(IsSWPrefetch); }
202 bool isHWPrefetch() const { return testCmdAttrib(IsHWPrefetch); }
203 bool isPrefetch() const { return testCmdAttrib(IsSWPrefetch) ||
204 testCmdAttrib(IsHWPrefetch); }
205 bool isError() const { return testCmdAttrib(IsError); }
206 bool isPrint() const { return testCmdAttrib(IsPrint); }
207 bool isFlush() const { return testCmdAttrib(IsFlush); }
208
209 const Command
210 responseCommand() const
211 {
212 return commandInfo[cmd].response;
213 }
214
215 /// Return the string to a cmd given by idx.
216 const std::string &toString() const { return commandInfo[cmd].str; }
217 int toInt() const { return (int)cmd; }
218
219 MemCmd(Command _cmd) : cmd(_cmd) { }
220 MemCmd(int _cmd) : cmd((Command)_cmd) { }
221 MemCmd() : cmd(InvalidCmd) { }
222
223 bool operator==(MemCmd c2) const { return (cmd == c2.cmd); }
224 bool operator!=(MemCmd c2) const { return (cmd != c2.cmd); }
225};
226
227/**
228 * A Packet is used to encapsulate a transfer between two objects in
229 * the memory system (e.g., the L1 and L2 cache). (In contrast, a
230 * single Request travels all the way from the requester to the
231 * ultimate destination and back, possibly being conveyed by several
232 * different Packets along the way.)
233 */
234class Packet : public Printable
235{
236 public:
237 typedef uint32_t FlagsType;
238 typedef ::Flags<FlagsType> Flags;
239
240 private:
241 static const FlagsType PUBLIC_FLAGS = 0x00000000;
242 static const FlagsType PRIVATE_FLAGS = 0x00007F0F;
243 static const FlagsType COPY_FLAGS = 0x0000000F;
244
245 static const FlagsType SHARED = 0x00000001;
246 // Special control flags
247 /// Special timing-mode atomic snoop for multi-level coherence.
248 static const FlagsType EXPRESS_SNOOP = 0x00000002;
249 /// Does supplier have exclusive copy?
250 /// Useful for multi-level coherence.
251 static const FlagsType SUPPLY_EXCLUSIVE = 0x00000004;
252 // Snoop response flags
253 static const FlagsType MEM_INHIBIT = 0x00000008;
254 /// Are the 'addr' and 'size' fields valid?
255 static const FlagsType VALID_ADDR = 0x00000100;
256 static const FlagsType VALID_SIZE = 0x00000200;
257 /// Is the data pointer set to a value that shouldn't be freed
258 /// when the packet is destroyed?
259 static const FlagsType STATIC_DATA = 0x00001000;
260 /// The data pointer points to a value that should be freed when
261 /// the packet is destroyed. The pointer is assumed to be pointing
262 /// to an array, and delete [] is consequently called
263 static const FlagsType DYNAMIC_DATA = 0x00002000;
264 /// suppress the error if this packet encounters a functional
265 /// access failure.
266 static const FlagsType SUPPRESS_FUNC_ERROR = 0x00008000;
267 // Signal block present to squash prefetch and cache evict packets
268 // through express snoop flag
269 static const FlagsType BLOCK_CACHED = 0x00010000;
270
271 Flags flags;
272
273 public:
274 typedef MemCmd::Command Command;
275
276 /// The command field of the packet.
277 MemCmd cmd;
278
279 /// A pointer to the original request.
280 const RequestPtr req;
281
282 private:
283 /**
284 * A pointer to the data being transfered. It can be differnt
285 * sizes at each level of the heirarchy so it belongs in the
286 * packet, not request. This may or may not be populated when a
287 * responder recieves the packet. If not populated it memory should
288 * be allocated.
289 */
290 PacketDataPtr data;
291
292 /// The address of the request. This address could be virtual or
293 /// physical, depending on the system configuration.
294 Addr addr;
295
296 /// True if the request targets the secure memory space.
297 bool _isSecure;
298
299 /// The size of the request or transfer.
300 unsigned size;
301
302 /**
303 * The original value of the command field. Only valid when the
304 * current command field is an error condition; in that case, the
305 * previous contents of the command field are copied here. This
306 * field is *not* set on non-error responses.
307 */
308 MemCmd origCmd;
309
310 /**
311 * Track the bytes found that satisfy a functional read.
312 */
313 std::vector<bool> bytesValid;
314
315 public:
316
317 /**
318 * The extra delay from seeing the packet until the header is
319 * transmitted. This delay is used to communicate the crossbar
320 * forwarding latency to the neighbouring object (e.g. a cache)
321 * that actually makes the packet wait. As the delay is relative,
322 * a 32-bit unsigned should be sufficient.
323 */
324 uint32_t headerDelay;
325
326 /**
327 * The extra pipelining delay from seeing the packet until the end of
328 * payload is transmitted by the component that provided it (if
329 * any). This includes the header delay. Similar to the header
330 * delay, this is used to make up for the fact that the
331 * crossbar does not make the packet wait. As the delay is
332 * relative, a 32-bit unsigned should be sufficient.
333 */
334 uint32_t payloadDelay;
335
336 /**
337 * A virtual base opaque structure used to hold state associated
338 * with the packet (e.g., an MSHR), specific to a MemObject that
339 * sees the packet. A pointer to this state is returned in the
340 * packet's response so that the MemObject in question can quickly
341 * look up the state needed to process it. A specific subclass
342 * would be derived from this to carry state specific to a
343 * particular sending device.
344 *
345 * As multiple MemObjects may add their SenderState throughout the
346 * memory system, the SenderStates create a stack, where a
347 * MemObject can add a new Senderstate, as long as the
348 * predecessing SenderState is restored when the response comes
349 * back. For this reason, the predecessor should always be
350 * populated with the current SenderState of a packet before
351 * modifying the senderState field in the request packet.
352 */
353 struct SenderState
354 {
355 SenderState* predecessor;
356 SenderState() : predecessor(NULL) {}
357 virtual ~SenderState() {}
358 };
359
360 /**
361 * Object used to maintain state of a PrintReq. The senderState
362 * field of a PrintReq should always be of this type.
363 */
364 class PrintReqState : public SenderState
365 {
366 private:
367 /**
368 * An entry in the label stack.
369 */
370 struct LabelStackEntry
371 {
372 const std::string label;
373 std::string *prefix;
374 bool labelPrinted;
375 LabelStackEntry(const std::string &_label, std::string *_prefix);
376 };
377
378 typedef std::list<LabelStackEntry> LabelStack;
379 LabelStack labelStack;
380
381 std::string *curPrefixPtr;
382
383 public:
384 std::ostream &os;
385 const int verbosity;
386
387 PrintReqState(std::ostream &os, int verbosity = 0);
388 ~PrintReqState();
389
390 /**
391 * Returns the current line prefix.
392 */
393 const std::string &curPrefix() { return *curPrefixPtr; }
394
395 /**
396 * Push a label onto the label stack, and prepend the given
397 * prefix string onto the current prefix. Labels will only be
398 * printed if an object within the label's scope is printed.
399 */
400 void pushLabel(const std::string &lbl,
401 const std::string &prefix = " ");
402
403 /**
404 * Pop a label off the label stack.
405 */
406 void popLabel();
407
408 /**
409 * Print all of the pending unprinted labels on the
410 * stack. Called by printObj(), so normally not called by
411 * users unless bypassing printObj().
412 */
413 void printLabels();
414
415 /**
416 * Print a Printable object to os, because it matched the
417 * address on a PrintReq.
418 */
419 void printObj(Printable *obj);
420 };
421
422 /**
423 * This packet's sender state. Devices should use dynamic_cast<>
424 * to cast to the state appropriate to the sender. The intent of
425 * this variable is to allow a device to attach extra information
426 * to a request. A response packet must return the sender state
427 * that was attached to the original request (even if a new packet
428 * is created).
429 */
430 SenderState *senderState;
431
432 /**
433 * Push a new sender state to the packet and make the current
434 * sender state the predecessor of the new one. This should be
435 * prefered over direct manipulation of the senderState member
436 * variable.
437 *
438 * @param sender_state SenderState to push at the top of the stack
439 */
440 void pushSenderState(SenderState *sender_state);
441
442 /**
443 * Pop the top of the state stack and return a pointer to it. This
444 * assumes the current sender state is not NULL. This should be
445 * preferred over direct manipulation of the senderState member
446 * variable.
447 *
448 * @return The current top of the stack
449 */
450 SenderState *popSenderState();
451
452 /**
453 * Go through the sender state stack and return the first instance
454 * that is of type T (as determined by a dynamic_cast). If there
455 * is no sender state of type T, NULL is returned.
456 *
457 * @return The topmost state of type T
458 */
459 template <typename T>
460 T * findNextSenderState() const
461 {
462 T *t = NULL;
463 SenderState* sender_state = senderState;
464 while (t == NULL && sender_state != NULL) {
465 t = dynamic_cast<T*>(sender_state);
466 sender_state = sender_state->predecessor;
467 }
468 return t;
469 }
470
471 /// Return the string name of the cmd field (for debugging and
472 /// tracing).
473 const std::string &cmdString() const { return cmd.toString(); }
474
475 /// Return the index of this command.
476 inline int cmdToIndex() const { return cmd.toInt(); }
477
478 bool isRead() const { return cmd.isRead(); }
479 bool isWrite() const { return cmd.isWrite(); }
480 bool isUpgrade() const { return cmd.isUpgrade(); }
481 bool isRequest() const { return cmd.isRequest(); }
482 bool isResponse() const { return cmd.isResponse(); }
483 bool needsExclusive() const { return cmd.needsExclusive(); }
484 bool needsResponse() const { return cmd.needsResponse(); }
485 bool isInvalidate() const { return cmd.isInvalidate(); }
486 bool isWriteInvalidate() const { return cmd.isWriteInvalidate(); }
487 bool hasData() const { return cmd.hasData(); }
488 bool isLLSC() const { return cmd.isLLSC(); }
489 bool isError() const { return cmd.isError(); }
490 bool isPrint() const { return cmd.isPrint(); }
491 bool isFlush() const { return cmd.isFlush(); }
492
493 // Snoop flags
494 void assertMemInhibit()
495 {
496 assert(isRequest());
497 assert(!flags.isSet(MEM_INHIBIT));
498 flags.set(MEM_INHIBIT);
499 }
500 bool memInhibitAsserted() const { return flags.isSet(MEM_INHIBIT); }
501 void assertShared() { flags.set(SHARED); }
502 bool sharedAsserted() const { return flags.isSet(SHARED); }
503
504 // Special control flags
505 void setExpressSnoop() { flags.set(EXPRESS_SNOOP); }
506 bool isExpressSnoop() const { return flags.isSet(EXPRESS_SNOOP); }
507 void setSupplyExclusive() { flags.set(SUPPLY_EXCLUSIVE); }
508 void clearSupplyExclusive() { flags.clear(SUPPLY_EXCLUSIVE); }
509 bool isSupplyExclusive() const { return flags.isSet(SUPPLY_EXCLUSIVE); }
510 void setSuppressFuncError() { flags.set(SUPPRESS_FUNC_ERROR); }
511 bool suppressFuncError() const { return flags.isSet(SUPPRESS_FUNC_ERROR); }
512 void setBlockCached() { flags.set(BLOCK_CACHED); }
513 bool isBlockCached() const { return flags.isSet(BLOCK_CACHED); }
514 void clearBlockCached() { flags.clear(BLOCK_CACHED); }
515
516 // Network error conditions... encapsulate them as methods since
517 // their encoding keeps changing (from result field to command
518 // field, etc.)
519 void
520 setBadAddress()
521 {
522 assert(isResponse());
523 cmd = MemCmd::BadAddressError;
524 }
525
526 bool hadBadAddress() const { return cmd == MemCmd::BadAddressError; }
527 void copyError(Packet *pkt) { assert(pkt->isError()); cmd = pkt->cmd; }
528
529 Addr getAddr() const { assert(flags.isSet(VALID_ADDR)); return addr; }
530 /**
531 * Update the address of this packet mid-transaction. This is used
532 * by the address mapper to change an already set address to a new
533 * one based on the system configuration. It is intended to remap
534 * an existing address, so it asserts that the current address is
535 * valid.
536 */
537 void setAddr(Addr _addr) { assert(flags.isSet(VALID_ADDR)); addr = _addr; }
538
539 unsigned getSize() const { assert(flags.isSet(VALID_SIZE)); return size; }
540 Addr getOffset(int blkSize) const { return getAddr() & (Addr)(blkSize - 1); }
541
542 bool isSecure() const
543 {
544 assert(flags.isSet(VALID_ADDR));
545 return _isSecure;
546 }
547
548 /**
549 * It has been determined that the SC packet should successfully update
550 * memory. Therefore, convert this SC packet to a normal write.
551 */
552 void
553 convertScToWrite()
554 {
555 assert(isLLSC());
556 assert(isWrite());
557 cmd = MemCmd::WriteReq;
558 }
559
560 /**
561 * When ruby is in use, Ruby will monitor the cache line and thus M5
562 * phys memory should treat LL ops as normal reads.
563 */
564 void
565 convertLlToRead()
566 {
567 assert(isLLSC());
568 assert(isRead());
569 cmd = MemCmd::ReadReq;
570 }
571
572 /**
573 * Constructor. Note that a Request object must be constructed
574 * first, but the Requests's physical address and size fields need
575 * not be valid. The command must be supplied.
576 */
577 Packet(const RequestPtr _req, MemCmd _cmd)
578 : cmd(_cmd), req(_req), data(nullptr), addr(0), _isSecure(false),
579 size(0), headerDelay(0), payloadDelay(0),
580 senderState(NULL)
581 {
582 if (req->hasPaddr()) {
583 addr = req->getPaddr();
584 flags.set(VALID_ADDR);
585 _isSecure = req->isSecure();
586 }
587 if (req->hasSize()) {
588 size = req->getSize();
589 flags.set(VALID_SIZE);
590 }
591 }
592
593 /**
594 * Alternate constructor if you are trying to create a packet with
595 * a request that is for a whole block, not the address from the
596 * req. this allows for overriding the size/addr of the req.
597 */
598 Packet(const RequestPtr _req, MemCmd _cmd, int _blkSize)
599 : cmd(_cmd), req(_req), data(nullptr), addr(0), _isSecure(false),
600 headerDelay(0), payloadDelay(0),
601 senderState(NULL)
602 {
603 if (req->hasPaddr()) {
604 addr = req->getPaddr() & ~(_blkSize - 1);
605 flags.set(VALID_ADDR);
606 _isSecure = req->isSecure();
607 }
608 size = _blkSize;
609 flags.set(VALID_SIZE);
610 }
611
612 /**
613 * Alternate constructor for copying a packet. Copy all fields
614 * *except* if the original packet's data was dynamic, don't copy
615 * that, as we can't guarantee that the new packet's lifetime is
616 * less than that of the original packet. In this case the new
617 * packet should allocate its own data.
618 */
619 Packet(PacketPtr pkt, bool clear_flags, bool alloc_data)
620 : cmd(pkt->cmd), req(pkt->req),
621 data(nullptr),
622 addr(pkt->addr), _isSecure(pkt->_isSecure), size(pkt->size),
623 bytesValid(pkt->bytesValid),
624 headerDelay(pkt->headerDelay),
625 payloadDelay(pkt->payloadDelay),
626 senderState(pkt->senderState)
627 {
628 if (!clear_flags)
629 flags.set(pkt->flags & COPY_FLAGS);
630
631 flags.set(pkt->flags & (VALID_ADDR|VALID_SIZE));
632
633 // should we allocate space for data, or not, the express
634 // snoops do not need to carry any data as they only serve to
635 // co-ordinate state changes
636 if (alloc_data) {
637 // even if asked to allocate data, if the original packet
638 // holds static data, then the sender will not be doing
639 // any memcpy on receiving the response, thus we simply
640 // carry the pointer forward
641 if (pkt->flags.isSet(STATIC_DATA)) {
642 data = pkt->data;
643 flags.set(STATIC_DATA);
644 } else {
645 allocate();
646 }
647 }
648 }
649
650 /**
651 * Generate the appropriate read MemCmd based on the Request flags.
652 */
653 static MemCmd
654 makeReadCmd(const RequestPtr req)
655 {
656 if (req->isLLSC())
657 return MemCmd::LoadLockedReq;
658 else if (req->isPrefetch())
659 return MemCmd::SoftPFReq;
660 else
661 return MemCmd::ReadReq;
662 }
663
664 /**
665 * Generate the appropriate write MemCmd based on the Request flags.
666 */
667 static MemCmd
668 makeWriteCmd(const RequestPtr req)
669 {
670 if (req->isLLSC())
671 return MemCmd::StoreCondReq;
672 else if (req->isSwap())
673 return MemCmd::SwapReq;
674 else
675 return MemCmd::WriteReq;
676 }
677
678 /**
679 * Constructor-like methods that return Packets based on Request objects.
680 * Fine-tune the MemCmd type if it's not a vanilla read or write.
681 */
682 static PacketPtr
683 createRead(const RequestPtr req)
684 {
685 return new Packet(req, makeReadCmd(req));
686 }
687
688 static PacketPtr
689 createWrite(const RequestPtr req)
690 {
691 return new Packet(req, makeWriteCmd(req));
692 }
693
694 /**
695 * clean up packet variables
696 */
697 ~Packet()
698 {
699 // Delete the request object if this is a request packet which
700 // does not need a response, because the requester will not get
701 // a chance. If the request packet needs a response then the
702 // request will be deleted on receipt of the response
703 // packet. We also make sure to never delete the request for
704 // express snoops, even for cases when responses are not
705 // needed (CleanEvict and Writeback), since the snoop packet
706 // re-uses the same request.
707 if (req && isRequest() && !needsResponse() &&
708 !isExpressSnoop()) {
709 delete req;
710 }
711 deleteData();
712 }
713
714 /**
715 * Take a request packet and modify it in place to be suitable for
716 * returning as a response to that request.
717 */
718 void
719 makeResponse()
720 {
721 assert(needsResponse());
722 assert(isRequest());
723 origCmd = cmd;
724 cmd = cmd.responseCommand();
725
726 // responses are never express, even if the snoop that
727 // triggered them was
728 flags.clear(EXPRESS_SNOOP);
729 }
730
731 void
732 makeAtomicResponse()
733 {
734 makeResponse();
735 }
736
737 void
738 makeTimingResponse()
739 {
740 makeResponse();
741 }
742
743 void
744 setFunctionalResponseStatus(bool success)
745 {
746 if (!success) {
747 if (isWrite()) {
748 cmd = MemCmd::FunctionalWriteError;
749 } else {
750 cmd = MemCmd::FunctionalReadError;
751 }
752 }
753 }
754
755 void
756 setSize(unsigned size)
757 {
758 assert(!flags.isSet(VALID_SIZE));
759
760 this->size = size;
761 flags.set(VALID_SIZE);
762 }
763
764
765 /**
766 * Set the data pointer to the following value that should not be
767 * freed. Static data allows us to do a single memcpy even if
768 * multiple packets are required to get from source to destination
769 * and back. In essence the pointer is set calling dataStatic on
770 * the original packet, and whenever this packet is copied and
771 * forwarded the same pointer is passed on. When a packet
772 * eventually reaches the destination holding the data, it is
773 * copied once into the location originally set. On the way back
774 * to the source, no copies are necessary.
775 */
776 template <typename T>
777 void
778 dataStatic(T *p)
779 {
780 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
781 data = (PacketDataPtr)p;
782 flags.set(STATIC_DATA);
783 }
784
785 /**
786 * Set the data pointer to the following value that should not be
787 * freed. This version of the function allows the pointer passed
788 * to us to be const. To avoid issues down the line we cast the
789 * constness away, the alternative would be to keep both a const
790 * and non-const data pointer and cleverly choose between
791 * them. Note that this is only allowed for static data.
792 */
793 template <typename T>
794 void
795 dataStaticConst(const T *p)
796 {
797 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
798 data = const_cast<PacketDataPtr>(p);
799 flags.set(STATIC_DATA);
800 }
801
802 /**
803 * Set the data pointer to a value that should have delete []
804 * called on it. Dynamic data is local to this packet, and as the
805 * packet travels from source to destination, forwarded packets
806 * will allocate their own data. When a packet reaches the final
807 * destination it will populate the dynamic data of that specific
808 * packet, and on the way back towards the source, memcpy will be
809 * invoked in every step where a new packet was created e.g. in
810 * the caches. Ultimately when the response reaches the source a
811 * final memcpy is needed to extract the data from the packet
812 * before it is deallocated.
813 */
814 template <typename T>
815 void
816 dataDynamic(T *p)
817 {
818 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
819 data = (PacketDataPtr)p;
820 flags.set(DYNAMIC_DATA);
821 }
822
823 /**
824 * get a pointer to the data ptr.
825 */
826 template <typename T>
827 T*
828 getPtr()
829 {
830 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA));
831 return (T*)data;
832 }
833
834 template <typename T>
835 const T*
836 getConstPtr() const
837 {
838 assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA));
839 return (const T*)data;
840 }
841
842 /**
843 * return the value of what is pointed to in the packet.
844 */
845 template <typename T>
846 T get() const;
847
848 /**
849 * set the value in the data pointer to v.
850 */
851 template <typename T>
852 void set(T v);
853
854 /**
855 * Copy data into the packet from the provided pointer.
856 */
857 void
858 setData(const uint8_t *p)
859 {
860 // we should never be copying data onto itself, which means we
861 // must idenfity packets with static data, as they carry the
862 // same pointer from source to destination and back
863 assert(p != getPtr<uint8_t>() || flags.isSet(STATIC_DATA));
864
865 if (p != getPtr<uint8_t>())
866 // for packet with allocated dynamic data, we copy data from
867 // one to the other, e.g. a forwarded response to a response
868 std::memcpy(getPtr<uint8_t>(), p, getSize());
869 }
870
871 /**
872 * Copy data into the packet from the provided block pointer,
873 * which is aligned to the given block size.
874 */
875 void
876 setDataFromBlock(const uint8_t *blk_data, int blkSize)
877 {
878 setData(blk_data + getOffset(blkSize));
879 }
880
881 /**
882 * Copy data from the packet to the provided block pointer, which
883 * is aligned to the given block size.
884 */
885 void
886 writeData(uint8_t *p) const
887 {
888 std::memcpy(p, getConstPtr<uint8_t>(), getSize());
889 }
890
891 /**
892 * Copy data from the packet to the memory at the provided pointer.
893 */
894 void
895 writeDataToBlock(uint8_t *blk_data, int blkSize) const
896 {
897 writeData(blk_data + getOffset(blkSize));
898 }
899
900 /**
901 * delete the data pointed to in the data pointer. Ok to call to
902 * matter how data was allocted.
903 */
904 void
905 deleteData()
906 {
907 if (flags.isSet(DYNAMIC_DATA))
908 delete [] data;
909
910 flags.clear(STATIC_DATA|DYNAMIC_DATA);
911 data = NULL;
912 }
913
914 /** Allocate memory for the packet. */
915 void
916 allocate()
917 {
918 assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
919 flags.set(DYNAMIC_DATA);
920 data = new uint8_t[getSize()];
921 }
922
923 /**
924 * Check a functional request against a memory value stored in
925 * another packet (i.e. an in-transit request or
926 * response). Returns true if the current packet is a read, and
927 * the other packet provides the data, which is then copied to the
928 * current packet. If the current packet is a write, and the other
929 * packet intersects this one, then we update the data
930 * accordingly.
931 */
932 bool
933 checkFunctional(PacketPtr other)
934 {
935 // all packets that are carrying a payload should have a valid
936 // data pointer
937 return checkFunctional(other, other->getAddr(), other->isSecure(),
938 other->getSize(),
939 other->hasData() ?
940 other->getPtr<uint8_t>() : NULL);
941 }
942
943 /**
944 * Is this request notification of a clean or dirty eviction from the cache.
945 **/
946 bool
947 evictingBlock() const
948 {
949 return (cmd == MemCmd::Writeback ||
950 cmd == MemCmd::CleanEvict);
951 }
952
953 /**
954 * Does the request need to check for cached copies of the same block
955 * in the memory hierarchy above.
956 **/
957 bool
958 mustCheckAbove() const
959 {
960 return (cmd == MemCmd::HardPFReq ||
961 evictingBlock());
962 }
963
964 /**
965 * Check a functional request against a memory value represented
966 * by a base/size pair and an associated data array. If the
967 * current packet is a read, it may be satisfied by the memory
968 * value. If the current packet is a write, it may update the
969 * memory value.
970 */
971 bool
972 checkFunctional(Printable *obj, Addr base, bool is_secure, int size,
973 uint8_t *_data);
974
975 /**
976 * Push label for PrintReq (safe to call unconditionally).
977 */
978 void
979 pushLabel(const std::string &lbl)
980 {
981 if (isPrint())
982 safe_cast<PrintReqState*>(senderState)->pushLabel(lbl);
983 }
984
985 /**
986 * Pop label for PrintReq (safe to call unconditionally).
987 */
988 void
989 popLabel()
990 {
991 if (isPrint())
992 safe_cast<PrintReqState*>(senderState)->popLabel();
993 }
994
995 void print(std::ostream &o, int verbosity = 0,
996 const std::string &prefix = "") const;
997
998 /**
999 * A no-args wrapper of print(std::ostream...)
1000 * meant to be invoked from DPRINTFs
1001 * avoiding string overheads in fast mode
1002 * @return string with the request's type and start<->end addresses
1003 */
1004 std::string print() const;
1005};
1006
1007#endif //__MEM_PACKET_HH