1/*
2 * Copyright (c) 2014 ARM Limited
3 * All rights reserved
4 *
5 * The license below extends only to copyright in the software and shall
6 * not be construed as granting a license to any other intellectual
7 * property including but not limited to intellectual property relating
8 * to a hardware implementation of the functionality of the software
9 * licensed hereunder.  You may use the software subject to the license
10 * terms below provided that you ensure that this notice is replicated
11 * unmodified and in its entirety in all distributions of the software,
12 * modified or unmodified, in source code or in binary form.
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions are
16 * met: redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer;
18 * redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution;
21 * neither the name of the copyright holders nor the names of its
22 * contributors may be used to endorse or promote products derived from
23 * this software without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
26 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
27 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
28 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
29 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
30 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
31 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
35 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36 *
37 * Authors: Rune Holm
38 *          Marco Elver
39 */
40
41#include "mem/mem_checker.hh"
42
43#include <cassert>
44
45void
46MemChecker::WriteCluster::startWrite(MemChecker::Serial serial, Tick _start,
47                                     uint8_t data)
48{
49    assert(!isComplete());
50
51    if (start == TICK_FUTURE) {
52        // Initialize a fresh write cluster
53        start = _start;
54    }
55    chatty_assert(start <= _start, "WriteClusters must filled in order!");
56
57    ++numIncomplete;
58
59    if (complete != TICK_FUTURE) {
60       // Reopen a closed write cluster
61        assert(_start < complete);  // should open a new write cluster, instead;
62        // also somewhat fishy wrt causality / ordering of calls vs time
63        // progression TODO: Check me!
64        complete = TICK_FUTURE;
65    }
66
67    // Create new transaction, and denote completion time to be in the future.
68    writes.insert(std::make_pair(serial,
69                  MemChecker::Transaction(serial, _start, TICK_FUTURE, data)));
70}
71
72void
73MemChecker::WriteCluster::completeWrite(MemChecker::Serial serial, Tick _complete)
74{
75    auto it = writes.find(serial);
76
77    if (it == writes.end()) {
78        warn("Could not locate write transaction: serial = %d, complete = %d\n",
79             serial, _complete);
80        return;
81    }
82
83    // Record completion time of the write
84    assert(it->second.complete == TICK_FUTURE);
85    it->second.complete = _complete;
86
87    // Update max completion time for the cluster
88    if (completeMax < _complete) {
89        completeMax = _complete;
90    }
91
92    if (--numIncomplete == 0) {
93        // All writes have completed, this cluster is now complete and will be
94        // assigned the max of completion tick values among all writes.
95        //
96        // Note that we cannot simply keep updating complete, because that would
97        // count the cluster as closed already.  Instead, we keep TICK_FUTURE
98        // until all writes have completed.
99        complete = completeMax;
100    }
101}
102
103void
104MemChecker::WriteCluster::abortWrite(MemChecker::Serial serial)
105{
106    if (!writes.erase(serial)) {
107        warn("Could not locate write transaction: serial = %d\n", serial);
108        return;
109    }
110
111    if (--numIncomplete == 0 && !writes.empty()) {
112        // This write cluster is now complete, and we can assign the current
113        // completeMax value.
114        complete = completeMax;
115    }
116
117    // Note: this WriteCluster is in pristine state if this was the only
118    // write present; the cluster will get reused through
119    // getIncompleteWriteCluster().
120}
121
122void
123MemChecker::ByteTracker::startRead(MemChecker::Serial serial, Tick start)
124{
125    outstandingReads.insert(std::make_pair(serial,
126            MemChecker::Transaction(serial, start, TICK_FUTURE)));
127}
128
129bool
130MemChecker::ByteTracker::inExpectedData(Tick start, Tick complete, uint8_t data)
131{
132    _lastExpectedData.clear();
133
134    bool wc_overlap = true;
135
136    // Find the last value read from the location
137    const Transaction& last_obs =
138        *lastCompletedTransaction(&readObservations, start);
139    bool last_obs_valid = (last_obs.complete != TICK_INITIAL);
140
141    // Scan backwards through the write clusters to find the closest younger
142    // preceding & overlapping writes.
143    for (auto cluster = writeClusters.rbegin();
144         cluster != writeClusters.rend() && wc_overlap; ++cluster) {
145        for (const auto& addr_write : cluster->writes) {
146            const Transaction& write = addr_write.second;
147
148            if (write.complete < last_obs.start) {
149                // If this write transaction completed before the last
150                // observation, we ignore it as the last_observation has the
151                // correct value
152                continue;
153            }
154
155            if (write.data == data) {
156                // Found a match, end search.
157                return true;
158            }
159
160            // Record possible, but non-matching data for debugging
161            _lastExpectedData.push_back(write.data);
162
163            if (write.complete > start) {
164                // This write overlapped with the transaction we want to check
165                // -> continue checking the overlapping write cluster
166                continue;
167            }
168
169            // This write cluster has writes that have completed before the
170            // checked transaction. There is no need to check an earlier
171            // write-cluster -> set the exit condition for the outer loop
172            wc_overlap = false;
173
174            if (last_obs.complete < write.start) {
175                // We found a write which started after the last observed read,
176                // therefore we can not longer consider the value seen by the
177                // last observation as a valid expected value.
178                //
179                // Once all writes have been iterated through, we can check if
180                // the last observation is still valid to compare against.
181                last_obs_valid = false;
182            }
183        }
184    }
185
186    // We have not found any matching write, so far; check other sources of
187    // confirmation
188    if (last_obs_valid) {
189        // The last observation is not outdated according to the writes we have
190        // seen so far.
191        assert(last_obs.complete <= start);
192        if (last_obs.data == data) {
193            // Matched data from last observation -> all good
194            return true;
195        }
196        // Record non-matching, but possible value
197        _lastExpectedData.push_back(last_obs.data);
198    } else {
199        // We have not seen any valid observation, and the only writes
200        // observed are overlapping, so anything (in particular the
201        // initialisation value) goes
202        // NOTE: We can overlap with multiple write clusters, here
203        if (!writeClusters.empty() && wc_overlap) {
204            // ensure that all write clusters really overlap this read
205            assert(writeClusters.begin()->start < complete &&
206                   writeClusters.rbegin()->complete > start);
207            return true;
208        }
209    }
210
211    if (_lastExpectedData.empty()) {
212        assert(last_obs.complete == TICK_INITIAL);
213        // We have not found any possible (non-matching data). Can happen in
214        // initial system state
215        DPRINTF(MemChecker, "no last observation nor write! start = %d, "\
216                "complete = %d, data = %#x\n", start, complete, data);
217        return true;
218    }
219    return false;
220}
221
222bool
223MemChecker::ByteTracker::completeRead(MemChecker::Serial serial,
224                                      Tick complete, uint8_t data)
225{
226    auto it = outstandingReads.find(serial);
227
228    if (it == outstandingReads.end()) {
229        // Can happen if concurrent with reset_address_range
230        warn("Could not locate read transaction: serial = %d, complete = %d\n",
231             serial, complete);
232        return true;
233    }
234
235    Tick start = it->second.start;
236    outstandingReads.erase(it);
237
238    // Verify data
239    const bool result = inExpectedData(start, complete, data);
240
241    readObservations.emplace_back(serial, start, complete, data);
242    pruneTransactions();
243
244    return result;
245}
246
247MemChecker::WriteCluster*
248MemChecker::ByteTracker::getIncompleteWriteCluster()
249{
250    if (writeClusters.empty() || writeClusters.back().isComplete()) {
251        writeClusters.emplace_back();
252    }
253
254    return &writeClusters.back();
255}
256
257void
258MemChecker::ByteTracker::startWrite(MemChecker::Serial serial, Tick start,
259                                    uint8_t data)
260{
261    getIncompleteWriteCluster()->startWrite(serial, start, data);
262}
263
264void
265MemChecker::ByteTracker::completeWrite(MemChecker::Serial serial, Tick complete)
266{
267    getIncompleteWriteCluster()->completeWrite(serial, complete);
268    pruneTransactions();
269}
270
271void
272MemChecker::ByteTracker::abortWrite(MemChecker::Serial serial)
273{
274    getIncompleteWriteCluster()->abortWrite(serial);
275}
276
277void
278MemChecker::ByteTracker::pruneTransactions()
279{
280    // Obtain tick of first outstanding read. If there are no outstanding
281    // reads, we use curTick(), i.e. we will remove all readObservation except
282    // the most recent one.
283    const Tick before = outstandingReads.empty() ? curTick() :
284                        outstandingReads.begin()->second.start;
285
286    // Pruning of readObservations
287    readObservations.erase(readObservations.begin(),
288                           lastCompletedTransaction(&readObservations, before));
289
290    // Pruning of writeClusters
291    if (!writeClusters.empty()) {
292        writeClusters.erase(writeClusters.begin(),
293                            lastCompletedTransaction(&writeClusters, before));
294    }
295}
296
297bool
298MemChecker::completeRead(MemChecker::Serial serial, Tick complete,
299                         Addr addr, size_t size, uint8_t *data)
300{
301    bool result = true;
302
303    DPRINTF(MemChecker,
304            "completing read: serial = %d, complete = %d, "
305            "addr = %#llx, size = %d\n", serial, complete, addr, size);
306
307    for (size_t i = 0; i < size; ++i) {
308        ByteTracker *tracker = getByteTracker(addr + i);
309
310        if (!tracker->completeRead(serial, complete, data[i])) {
311            // Generate error message, and aggregate all failures for the bytes
312            // considered in this transaction in one message.
313            if (result) {
314                result = false;
315                errorMessage = "";
316            } else {
317                errorMessage += "\n";
318            }
319
320            errorMessage += csprintf("  Read transaction for address %#llx "
321                                     "failed: received %#x, expected ",
322                                     (unsigned long long)(addr + i), data[i]);
323
324            for (size_t j = 0; j < tracker->lastExpectedData().size(); ++j) {
325                errorMessage +=
326                    csprintf("%#x%s",
327                             tracker->lastExpectedData()[j],
328                             (j == tracker->lastExpectedData().size() - 1)
329                             ? "" : "|");
330            }
331        }
332    }
333
334    if (!result) {
335        DPRINTF(MemChecker, "read of %#llx @ cycle %d failed:\n%s\n", addr,
336                complete, errorMessage);
337    }
338
339    return result;
340}
341
342void
343MemChecker::reset(Addr addr, size_t size)
344{
345    for (size_t i = 0; i < size; ++i) {
346        byte_trackers.erase(addr + i);
347    }
348}
349
350MemChecker*
351MemCheckerParams::create()
352{
353    return new MemChecker(this);
354}
355