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