summaryrefslogtreecommitdiff
path: root/src/mem/packet.hh
blob: 4d57aee75c4bdd91e09242cc7b53fc4991cc721a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
/*
 * Copyright (c) 2006 The Regents of The University of Michigan
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met: redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer;
 * redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution;
 * neither the name of the copyright holders nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Authors: Ron Dreslinski
 *          Steve Reinhardt
 *          Ali Saidi
 */

/**
 * @file
 * Declaration of the Packet class.
 */

#ifndef __MEM_PACKET_HH__
#define __MEM_PACKET_HH__

#include "mem/request.hh"
#include "sim/host.hh"
#include "sim/root.hh"
#include <list>
#include <cassert>

struct Packet;
typedef Packet* PacketPtr;
typedef uint8_t* PacketDataPtr;
typedef std::list<PacketPtr> PacketList;

//Coherence Flags
#define NACKED_LINE 1 << 0
#define SATISFIED 1 << 1
#define SHARED_LINE 1 << 2
#define CACHE_LINE_FILL 1 << 3
#define COMPRESSED 1 << 4
#define NO_ALLOCATE 1 << 5
#define SNOOP_COMMIT 1 << 6

/**
 * A Packet is used to encapsulate a transfer between two objects in
 * the memory system (e.g., the L1 and L2 cache).  (In contrast, a
 * single Request travels all the way from the requester to the
 * ultimate destination and back, possibly being conveyed by several
 * different Packets along the way.)
 */
class Packet
{
  public:
    /** Temporary FLAGS field until cache gets working, this should be in coherence/sender state. */
    uint64_t flags;

  private:
   /** A pointer to the data being transfered.  It can be differnt
    *    sizes at each level of the heirarchy so it belongs in the
    *    packet, not request. This may or may not be populated when a
    *    responder recieves the packet. If not populated it memory
    *    should be allocated.
    */
    PacketDataPtr data;

    /** Is the data pointer set to a value that shouldn't be freed
     *   when the packet is destroyed? */
    bool staticData;
    /** The data pointer points to a value that should be freed when
     *   the packet is destroyed. */
    bool dynamicData;
    /** the data pointer points to an array (thus delete [] ) needs to
     *   be called on it rather than simply delete.*/
    bool arrayData;


    /** The address of the request.  This address could be virtual or
     *   physical, depending on the system configuration. */
    Addr addr;

     /** The size of the request or transfer. */
    int size;

    /** Device address (e.g., bus ID) of the source of the
     *   transaction. The source is not responsible for setting this
     *   field; it is set implicitly by the interconnect when the
     *   packet * is first sent.  */
    short src;

    /** Device address (e.g., bus ID) of the destination of the
     *   transaction. The special value Broadcast indicates that the
     *   packet should be routed based on its address. This field is
     *   initialized in the constructor and is thus always valid
     *   (unlike * addr, size, and src). */
    short dest;

    /** Are the 'addr' and 'size' fields valid? */
    bool addrSizeValid;
    /** Is the 'src' field valid? */
    bool srcValid;


  public:

    /** Used to calculate latencies for each packet.*/
    Tick time;

    /** The special destination address indicating that the packet
     *   should be routed based on its address. */
    static const short Broadcast = -1;

    /** A pointer to the original request. */
    RequestPtr req;

    /** A virtual base opaque structure used to hold coherence-related
     *    state.  A specific subclass would be derived from this to
     *    carry state specific to a particular coherence protocol.  */
    class CoherenceState {
      public:
        virtual ~CoherenceState() {}
    };

    /** This packet's coherence state.  Caches should use
     *   dynamic_cast<> to cast to the state appropriate for the
     *   system's coherence protocol.  */
    CoherenceState *coherence;

    /** A virtual base opaque structure used to hold state associated
     *    with the packet but specific to the sending device (e.g., an
     *    MSHR).  A pointer to this state is returned in the packet's
     *    response so that the sender can quickly look up the state
     *    needed to process it.  A specific subclass would be derived
     *    from this to carry state specific to a particular sending
     *    device.  */
    class SenderState {
      public:
        virtual ~SenderState() {}
    };

    /** This packet's sender state.  Devices should use dynamic_cast<>
     *   to cast to the state appropriate to the sender. */
    SenderState *senderState;

  private:
    /** List of command attributes. */
    // If you add a new CommandAttribute, make sure to increase NUM_MEM_CMDS
    // as well.
    enum CommandAttribute
    {
        IsRead		= 1 << 0,
        IsWrite		= 1 << 1,
        IsPrefetch	= 1 << 2,
        IsInvalidate	= 1 << 3,
        IsRequest	= 1 << 4,
        IsResponse 	= 1 << 5,
        NeedsResponse	= 1 << 6,
        IsSWPrefetch    = 1 << 7,
        IsHWPrefetch    = 1 << 8,
        HasData		= 1 << 9
    };

//For statistics we need max number of commands, hard code it at
//20 for now.  @todo fix later
#define NUM_MEM_CMDS 1 << 10

  public:
    /** List of all commands associated with a packet. */
    enum Command
    {
        InvalidCmd      = 0,
        ReadReq		= IsRead  | IsRequest | NeedsResponse,
        WriteReq	= IsWrite | IsRequest | NeedsResponse | HasData,
        WriteReqNoAck	= IsWrite | IsRequest | HasData,
        ReadResp	= IsRead  | IsResponse | NeedsResponse | HasData,
        WriteResp	= IsWrite | IsResponse | NeedsResponse,
        Writeback       = IsWrite | IsRequest | HasData,
        SoftPFReq       = IsRead  | IsRequest | IsSWPrefetch | NeedsResponse,
        HardPFReq       = IsRead  | IsRequest | IsHWPrefetch | NeedsResponse,
        SoftPFResp      = IsRead  | IsResponse | IsSWPrefetch
                                | NeedsResponse | HasData,
        HardPFResp      = IsRead  | IsResponse | IsHWPrefetch
                                | NeedsResponse | HasData,
        InvalidateReq   = IsInvalidate | IsRequest,
        WriteInvalidateReq = IsWrite | IsInvalidate | IsRequest | HasData,
        UpgradeReq      = IsInvalidate | IsRequest,
        ReadExReq       = IsRead | IsInvalidate | IsRequest | NeedsResponse,
        ReadExResp      = IsRead | IsInvalidate | IsResponse
                                | NeedsResponse | HasData
    };

    /** Return the string name of the cmd field (for debugging and
     *   tracing). */
    const std::string &cmdString() const;

    /** Reutrn the string to a cmd given by idx. */
    const std::string &cmdIdxToString(Command idx);

    /** Return the index of this command. */
    inline int cmdToIndex() const { return (int) cmd; }

    /** The command field of the packet. */
    Command cmd;

    bool isRead() 	 { return (cmd & IsRead)  != 0; }
    bool isWrite()       { return (cmd & IsWrite) != 0; }
    bool isRequest()	 { return (cmd & IsRequest)  != 0; }
    bool isResponse()	 { return (cmd & IsResponse) != 0; }
    bool needsResponse() { return (cmd & NeedsResponse) != 0; }
    bool isInvalidate()  { return (cmd & IsInvalidate) != 0; }
    bool hasData()	 { return (cmd & HasData) != 0; }

    bool isCacheFill() { return (flags & CACHE_LINE_FILL) != 0; }
    bool isNoAllocate() { return (flags & NO_ALLOCATE) != 0; }
    bool isCompressed() { return (flags & COMPRESSED) != 0; }

    bool nic_pkt() { assert("Unimplemented\n" && 0); return false; }

    /** Possible results of a packet's request. */
    enum Result
    {
        Success,
        BadAddress,
        Nacked,
        Unknown
    };

    /** The result of this packet's request. */
    Result result;

    /** Accessor function that returns the source index of the packet. */
    short getSrc() const { assert(srcValid); return src; }
    void setSrc(short _src) { src = _src; srcValid = true; }

    /** Accessor function that returns the destination index of
        the packet. */
    short getDest() const { return dest; }
    void setDest(short _dest) { dest = _dest; }

    Addr getAddr() const { assert(addrSizeValid); return addr; }
    int getSize() const { assert(addrSizeValid); return size; }
    Addr getOffset(int blkSize) const { return addr & (Addr)(blkSize - 1); }

    void addrOverride(Addr newAddr) { assert(addrSizeValid); addr = newAddr; }
    void cmdOverride(Command newCmd) { cmd = newCmd; }

    /** Constructor.  Note that a Request object must be constructed
     *   first, but the Requests's physical address and size fields
     *   need not be valid. The command and destination addresses
     *   must be supplied.  */
    Packet(Request *_req, Command _cmd, short _dest)
        :  data(NULL), staticData(false), dynamicData(false), arrayData(false),
           addr(_req->paddr), size(_req->size), dest(_dest),
           addrSizeValid(_req->validPaddr),
           srcValid(false),
           req(_req), coherence(NULL), senderState(NULL), cmd(_cmd),
           result(Unknown)
    {
        flags = 0;
        time = curTick;
    }

    /** Alternate constructor if you are trying to create a packet with
     *  a request that is for a whole block, not the address from the req.
     *  this allows for overriding the size/addr of the req.*/
    Packet(Request *_req, Command _cmd, short _dest, int _blkSize)
        :  data(NULL), staticData(false), dynamicData(false), arrayData(false),
           addr(_req->paddr & ~(_blkSize - 1)), size(_blkSize),
           dest(_dest),
           addrSizeValid(_req->validPaddr), srcValid(false),
           req(_req), coherence(NULL), senderState(NULL), cmd(_cmd),
           result(Unknown)
    {
        flags = 0;
        time = curTick;
    }

    /** Destructor. */
    ~Packet()
    { deleteData(); }

    /** Reinitialize packet address and size from the associated
     *   Request object, and reset other fields that may have been
     *   modified by a previous transaction.  Typically called when a
     *   statically allocated Request/Packet pair is reused for
     *   multiple transactions. */
    void reinitFromRequest() {
        assert(req->validPaddr);
        addr = req->paddr;
        size = req->size;
        time = req->time;
        addrSizeValid = true;
        result = Unknown;
        if (dynamicData) {
            deleteData();
            dynamicData = false;
            arrayData = false;
        }
    }

    /** Take a request packet and modify it in place to be suitable
     *   for returning as a response to that request.  Used for timing
     *   accesses only.  For atomic and functional accesses, the
     *   request packet is always implicitly passed back *without*
     *   modifying the destination fields, so this function
     *   should not be called. */
    void makeTimingResponse() {
        assert(needsResponse());
        assert(isRequest());
        int icmd = (int)cmd;
        icmd &= ~(IsRequest);
        icmd |= IsResponse;
        cmd = (Command)icmd;
        dest = src;
        srcValid = false;
    }

    /** Take a request packet and modify it in place to be suitable
     *   for returning as a response to that request.
     */
    void makeAtomicResponse() {
        assert(needsResponse());
        assert(isRequest());
        int icmd = (int)cmd;
        icmd &= ~(IsRequest);
        icmd |= IsResponse;
        cmd = (Command)icmd;
    }

    /** Take a request packet that has been returned as NACKED and modify it so
     * that it can be sent out again. Only packets that need a response can be
     * NACKED, so verify that that is true. */
    void reinitNacked() {
        assert(needsResponse() && result == Nacked);
        dest =  Broadcast;
        result = Unknown;
    }


    /** Set the data pointer to the following value that should not be freed. */
    template <typename T>
    void dataStatic(T *p);

    /** Set the data pointer to a value that should have delete [] called on it.
     */
    template <typename T>
    void dataDynamicArray(T *p);

    /** set the data pointer to a value that should have delete called on it. */
    template <typename T>
    void dataDynamic(T *p);

    /** return the value of what is pointed to in the packet. */
    template <typename T>
    T get();

    /** get a pointer to the data ptr. */
    template <typename T>
    T* getPtr();

    /** set the value in the data pointer to v. */
    template <typename T>
    void set(T v);

    /** delete the data pointed to in the data pointer. Ok to call to matter how
     * data was allocted. */
    void deleteData();

    /** If there isn't data in the packet, allocate some. */
    void allocate();

    /** Do the packet modify the same addresses. */
    bool intersect(Packet *p);
};

bool fixPacket(Packet *func, Packet *timing);
#endif //__MEM_PACKET_HH