summaryrefslogtreecommitdiff
path: root/src/mem/abstract_mem.cc
blob: d913f05d3447a37636ced66e1c77a5fda8b634dc (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
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
/*
 * Copyright (c) 2010-2012,2017-2019 ARM Limited
 * All rights reserved
 *
 * The license below extends only to copyright in the software and shall
 * not be construed as granting a license to any other intellectual
 * property including but not limited to intellectual property relating
 * to a hardware implementation of the functionality of the software
 * licensed hereunder.  You may use the software subject to the license
 * terms below provided that you ensure that this notice is replicated
 * unmodified and in its entirety in all distributions of the software,
 * modified or unmodified, in source code or in binary form.
 *
 * Copyright (c) 2001-2005 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
 *          Ali Saidi
 *          Andreas Hansson
 */

#include "mem/abstract_mem.hh"

#include <vector>

#include "arch/locked_mem.hh"
#include "cpu/base.hh"
#include "cpu/thread_context.hh"
#include "debug/LLSC.hh"
#include "debug/MemoryAccess.hh"
#include "mem/packet_access.hh"
#include "sim/system.hh"

using namespace std;

AbstractMemory::AbstractMemory(const Params *p) :
    ClockedObject(p), range(params()->range), pmemAddr(NULL),
    backdoor(params()->range, nullptr,
             (MemBackdoor::Flags)(MemBackdoor::Readable |
                                  MemBackdoor::Writeable)),
    confTableReported(p->conf_table_reported), inAddrMap(p->in_addr_map),
    kvmMap(p->kvm_map), _system(NULL),
    stats(*this)
{
}

void
AbstractMemory::init()
{
    assert(system());

    if (size() % _system->getPageBytes() != 0)
        panic("Memory Size not divisible by page size\n");
}

void
AbstractMemory::setBackingStore(uint8_t* pmem_addr)
{
    // If there was an existing backdoor, let everybody know it's going away.
    if (backdoor.ptr())
        backdoor.invalidate();

    // The back door can't handle interleaved memory.
    backdoor.ptr(range.interleaved() ? nullptr : pmem_addr);

    pmemAddr = pmem_addr;
}

AbstractMemory::MemStats::MemStats(AbstractMemory &_mem)
    : Stats::Group(&_mem), mem(_mem),
    bytesRead(this, "bytes_read",
              "Number of bytes read from this memory"),
    bytesInstRead(this, "bytes_inst_read",
                  "Number of instructions bytes read from this memory"),
    bytesWritten(this, "bytes_written",
                 "Number of bytes written to this memory"),
    numReads(this, "num_reads",
             "Number of read requests responded to by this memory"),
    numWrites(this, "num_writes",
              "Number of write requests responded to by this memory"),
    numOther(this, "num_other",
             "Number of other requests responded to by this memory"),
    bwRead(this, "bw_read",
           "Total read bandwidth from this memory (bytes/s)"),
    bwInstRead(this, "bw_inst_read",
               "Instruction read bandwidth from this memory (bytes/s)"),
    bwWrite(this, "bw_write",
            "Write bandwidth from this memory (bytes/s)"),
    bwTotal(this, "bw_total",
            "Total bandwidth to/from this memory (bytes/s)")
{
}

void
AbstractMemory::MemStats::regStats()
{
    using namespace Stats;

    Stats::Group::regStats();

    System *sys = mem.system();
    assert(sys);
    const auto max_masters = sys->maxMasters();

    bytesRead
        .init(max_masters)
        .flags(total | nozero | nonan)
        ;
    for (int i = 0; i < max_masters; i++) {
        bytesRead.subname(i, sys->getMasterName(i));
    }

    bytesInstRead
        .init(max_masters)
        .flags(total | nozero | nonan)
        ;
    for (int i = 0; i < max_masters; i++) {
        bytesInstRead.subname(i, sys->getMasterName(i));
    }

    bytesWritten
        .init(max_masters)
        .flags(total | nozero | nonan)
        ;
    for (int i = 0; i < max_masters; i++) {
        bytesWritten.subname(i, sys->getMasterName(i));
    }

    numReads
        .init(max_masters)
        .flags(total | nozero | nonan)
        ;
    for (int i = 0; i < max_masters; i++) {
        numReads.subname(i, sys->getMasterName(i));
    }

    numWrites
        .init(max_masters)
        .flags(total | nozero | nonan)
        ;
    for (int i = 0; i < max_masters; i++) {
        numWrites.subname(i, sys->getMasterName(i));
    }

    numOther
        .init(max_masters)
        .flags(total | nozero | nonan)
        ;
    for (int i = 0; i < max_masters; i++) {
        numOther.subname(i, sys->getMasterName(i));
    }

    bwRead
        .precision(0)
        .prereq(bytesRead)
        .flags(total | nozero | nonan)
        ;
    for (int i = 0; i < max_masters; i++) {
        bwRead.subname(i, sys->getMasterName(i));
    }

    bwInstRead
        .precision(0)
        .prereq(bytesInstRead)
        .flags(total | nozero | nonan)
        ;
    for (int i = 0; i < max_masters; i++) {
        bwInstRead.subname(i, sys->getMasterName(i));
    }

    bwWrite
        .precision(0)
        .prereq(bytesWritten)
        .flags(total | nozero | nonan)
        ;
    for (int i = 0; i < max_masters; i++) {
        bwWrite.subname(i, sys->getMasterName(i));
    }

    bwTotal
        .precision(0)
        .prereq(bwTotal)
        .flags(total | nozero | nonan)
        ;
    for (int i = 0; i < max_masters; i++) {
        bwTotal.subname(i, sys->getMasterName(i));
    }

    bwRead = bytesRead / simSeconds;
    bwInstRead = bytesInstRead / simSeconds;
    bwWrite = bytesWritten / simSeconds;
    bwTotal = (bytesRead + bytesWritten) / simSeconds;
}

AddrRange
AbstractMemory::getAddrRange() const
{
    return range;
}

// Add load-locked to tracking list.  Should only be called if the
// operation is a load and the LLSC flag is set.
void
AbstractMemory::trackLoadLocked(PacketPtr pkt)
{
    const RequestPtr &req = pkt->req;
    Addr paddr = LockedAddr::mask(req->getPaddr());

    // first we check if we already have a locked addr for this
    // xc.  Since each xc only gets one, we just update the
    // existing record with the new address.
    list<LockedAddr>::iterator i;

    for (i = lockedAddrList.begin(); i != lockedAddrList.end(); ++i) {
        if (i->matchesContext(req)) {
            DPRINTF(LLSC, "Modifying lock record: context %d addr %#x\n",
                    req->contextId(), paddr);
            i->addr = paddr;
            return;
        }
    }

    // no record for this xc: need to allocate a new one
    DPRINTF(LLSC, "Adding lock record: context %d addr %#x\n",
            req->contextId(), paddr);
    lockedAddrList.push_front(LockedAddr(req));
}


// Called on *writes* only... both regular stores and
// store-conditional operations.  Check for conventional stores which
// conflict with locked addresses, and for success/failure of store
// conditionals.
bool
AbstractMemory::checkLockedAddrList(PacketPtr pkt)
{
    const RequestPtr &req = pkt->req;
    Addr paddr = LockedAddr::mask(req->getPaddr());
    bool isLLSC = pkt->isLLSC();

    // Initialize return value.  Non-conditional stores always
    // succeed.  Assume conditional stores will fail until proven
    // otherwise.
    bool allowStore = !isLLSC;

    // Iterate over list.  Note that there could be multiple matching records,
    // as more than one context could have done a load locked to this location.
    // Only remove records when we succeed in finding a record for (xc, addr);
    // then, remove all records with this address.  Failed store-conditionals do
    // not blow unrelated reservations.
    list<LockedAddr>::iterator i = lockedAddrList.begin();

    if (isLLSC) {
        while (i != lockedAddrList.end()) {
            if (i->addr == paddr && i->matchesContext(req)) {
                // it's a store conditional, and as far as the memory system can
                // tell, the requesting context's lock is still valid.
                DPRINTF(LLSC, "StCond success: context %d addr %#x\n",
                        req->contextId(), paddr);
                allowStore = true;
                break;
            }
            // If we didn't find a match, keep searching!  Someone else may well
            // have a reservation on this line here but we may find ours in just
            // a little while.
            i++;
        }
        req->setExtraData(allowStore ? 1 : 0);
    }
    // LLSCs that succeeded AND non-LLSC stores both fall into here:
    if (allowStore) {
        // We write address paddr.  However, there may be several entries with a
        // reservation on this address (for other contextIds) and they must all
        // be removed.
        i = lockedAddrList.begin();
        while (i != lockedAddrList.end()) {
            if (i->addr == paddr) {
                DPRINTF(LLSC, "Erasing lock record: context %d addr %#x\n",
                        i->contextId, paddr);
                ContextID owner_cid = i->contextId;
                assert(owner_cid != InvalidContextID);
                ContextID requester_cid = req->hasContextId() ?
                                           req->contextId() :
                                           InvalidContextID;
                if (owner_cid != requester_cid) {
                    ThreadContext* ctx = system()->getThreadContext(owner_cid);
                    TheISA::globalClearExclusive(ctx);
                }
                i = lockedAddrList.erase(i);
            } else {
                i++;
            }
        }
    }

    return allowStore;
}

#if TRACING_ON
static inline void
tracePacket(System *sys, const char *label, PacketPtr pkt)
{
    int size = pkt->getSize();
#if THE_ISA != NULL_ISA
    if (size == 1 || size == 2 || size == 4 || size == 8) {
        DPRINTF(MemoryAccess,"%s from %s of size %i on address %#x data "
                "%#x %c\n", label, sys->getMasterName(pkt->req->masterId()),
                size, pkt->getAddr(), pkt->getUintX(TheISA::GuestByteOrder),
                pkt->req->isUncacheable() ? 'U' : 'C');
        return;
    }
#endif
    DPRINTF(MemoryAccess, "%s from %s of size %i on address %#x %c\n",
            label, sys->getMasterName(pkt->req->masterId()),
            size, pkt->getAddr(), pkt->req->isUncacheable() ? 'U' : 'C');
    DDUMP(MemoryAccess, pkt->getConstPtr<uint8_t>(), pkt->getSize());
}

#   define TRACE_PACKET(A) tracePacket(system(), A, pkt)
#else
#   define TRACE_PACKET(A)
#endif

void
AbstractMemory::access(PacketPtr pkt)
{
    if (pkt->cacheResponding()) {
        DPRINTF(MemoryAccess, "Cache responding to %#llx: not responding\n",
                pkt->getAddr());
        return;
    }

    if (pkt->cmd == MemCmd::CleanEvict || pkt->cmd == MemCmd::WritebackClean) {
        DPRINTF(MemoryAccess, "CleanEvict  on 0x%x: not responding\n",
                pkt->getAddr());
      return;
    }

    assert(pkt->getAddrRange().isSubset(range));

    uint8_t *hostAddr = pmemAddr + pkt->getAddr() - range.start();

    if (pkt->cmd == MemCmd::SwapReq) {
        if (pkt->isAtomicOp()) {
            if (pmemAddr) {
                pkt->setData(hostAddr);
                (*(pkt->getAtomicOp()))(hostAddr);
            }
        } else {
            std::vector<uint8_t> overwrite_val(pkt->getSize());
            uint64_t condition_val64;
            uint32_t condition_val32;

            panic_if(!pmemAddr, "Swap only works if there is real memory " \
                     "(i.e. null=False)");

            bool overwrite_mem = true;
            // keep a copy of our possible write value, and copy what is at the
            // memory address into the packet
            pkt->writeData(&overwrite_val[0]);
            pkt->setData(hostAddr);

            if (pkt->req->isCondSwap()) {
                if (pkt->getSize() == sizeof(uint64_t)) {
                    condition_val64 = pkt->req->getExtraData();
                    overwrite_mem = !std::memcmp(&condition_val64, hostAddr,
                                                 sizeof(uint64_t));
                } else if (pkt->getSize() == sizeof(uint32_t)) {
                    condition_val32 = (uint32_t)pkt->req->getExtraData();
                    overwrite_mem = !std::memcmp(&condition_val32, hostAddr,
                                                 sizeof(uint32_t));
                } else
                    panic("Invalid size for conditional read/write\n");
            }

            if (overwrite_mem)
                std::memcpy(hostAddr, &overwrite_val[0], pkt->getSize());

            assert(!pkt->req->isInstFetch());
            TRACE_PACKET("Read/Write");
            stats.numOther[pkt->req->masterId()]++;
        }
    } else if (pkt->isRead()) {
        assert(!pkt->isWrite());
        if (pkt->isLLSC()) {
            assert(!pkt->fromCache());
            // if the packet is not coming from a cache then we have
            // to do the LL/SC tracking here
            trackLoadLocked(pkt);
        }
        if (pmemAddr) {
            pkt->setData(hostAddr);
        }
        TRACE_PACKET(pkt->req->isInstFetch() ? "IFetch" : "Read");
        stats.numReads[pkt->req->masterId()]++;
        stats.bytesRead[pkt->req->masterId()] += pkt->getSize();
        if (pkt->req->isInstFetch())
            stats.bytesInstRead[pkt->req->masterId()] += pkt->getSize();
    } else if (pkt->isInvalidate() || pkt->isClean()) {
        assert(!pkt->isWrite());
        // in a fastmem system invalidating and/or cleaning packets
        // can be seen due to cache maintenance requests

        // no need to do anything
    } else if (pkt->isWrite()) {
        if (writeOK(pkt)) {
            if (pmemAddr) {
                pkt->writeData(hostAddr);
                DPRINTF(MemoryAccess, "%s wrote %i bytes to address %x\n",
                        __func__, pkt->getSize(), pkt->getAddr());
            }
            assert(!pkt->req->isInstFetch());
            TRACE_PACKET("Write");
            stats.numWrites[pkt->req->masterId()]++;
            stats.bytesWritten[pkt->req->masterId()] += pkt->getSize();
        }
    } else {
        panic("Unexpected packet %s", pkt->print());
    }

    if (pkt->needsResponse()) {
        pkt->makeResponse();
    }
}

void
AbstractMemory::functionalAccess(PacketPtr pkt)
{
    assert(pkt->getAddrRange().isSubset(range));

    uint8_t *hostAddr = pmemAddr + pkt->getAddr() - range.start();

    if (pkt->isRead()) {
        if (pmemAddr) {
            pkt->setData(hostAddr);
        }
        TRACE_PACKET("Read");
        pkt->makeResponse();
    } else if (pkt->isWrite()) {
        if (pmemAddr) {
            pkt->writeData(hostAddr);
        }
        TRACE_PACKET("Write");
        pkt->makeResponse();
    } else if (pkt->isPrint()) {
        Packet::PrintReqState *prs =
            dynamic_cast<Packet::PrintReqState*>(pkt->senderState);
        assert(prs);
        // Need to call printLabels() explicitly since we're not going
        // through printObj().
        prs->printLabels();
        // Right now we just print the single byte at the specified address.
        ccprintf(prs->os, "%s%#x\n", prs->curPrefix(), *hostAddr);
    } else {
        panic("AbstractMemory: unimplemented functional command %s",
              pkt->cmdString());
    }
}