src/mem/mem_checker.cc - public/gem5 - Git at Google

 /*
  * Copyright (c) 2014 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.
  *
  * 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.
  */

 #include "mem/mem_checker.hh"

 #include "base/logging.hh"

 void
 MemChecker::WriteCluster::startWrite(MemChecker::Serial serial, Tick _start,
                                      uint8_t data)
 {
     assert(!isComplete());

     if (start == TICK_FUTURE) {
         // Initialize a fresh write cluster
         start = _start;
     }
     chatty_assert(start <= _start, "WriteClusters must filled in order!");

     ++numIncomplete;

     if (complete != TICK_FUTURE) {
         // Reopen a closed write cluster
         assert(_start < complete); // Should open a new write cluster instead
         // Also somewhat fishy wrt causality / ordering of calls vs time
         // progression TODO: Check me!
         complete = TICK_FUTURE;
     }

     // Create new transaction, and denote completion time to be in the future.
     writes.insert(std::make_pair(serial,
                   MemChecker::Transaction(serial, _start, TICK_FUTURE, data)));
 }

 void
 MemChecker::WriteCluster::completeWrite(MemChecker::Serial serial,
     Tick _complete)
 {
     auto it = writes.find(serial);

     if (it == writes.end()) {
         warn("Could not locate write transaction: serial = %d, "
              "complete = %d\n", serial, _complete);
         return;
     }

     // Record completion time of the write
     assert(it->second.complete == TICK_FUTURE);
     it->second.complete = _complete;

     // Update max completion time for the cluster
     if (completeMax < _complete) {
         completeMax = _complete;
     }

     if (--numIncomplete == 0) {
         // All writes have completed, this cluster is now complete and will be
         // assigned the max of completion tick values among all writes.
         //
         // Note that we cannot simply keep updating complete, because that
         // would count the cluster as closed already.  Instead, we keep
         // TICK_FUTURE until all writes have completed.
         complete = completeMax;
     }
 }

 void
 MemChecker::WriteCluster::abortWrite(MemChecker::Serial serial)
 {
     if (!writes.erase(serial)) {
         warn("Could not locate write transaction: serial = %d\n", serial);
         return;
     }

     if (--numIncomplete == 0 && !writes.empty()) {
         // This write cluster is now complete, and we can assign the current
         // completeMax value.
         complete = completeMax;
     }

     // Note: this WriteCluster is in pristine state if this was the only
     // write present; the cluster will get reused through
     // getIncompleteWriteCluster().
 }

 void
 MemChecker::ByteTracker::startRead(MemChecker::Serial serial, Tick start)
 {
     outstandingReads.insert(std::make_pair(serial,
             MemChecker::Transaction(serial, start, TICK_FUTURE)));
 }

 bool
 MemChecker::ByteTracker::inExpectedData(Tick start, Tick complete,
     uint8_t data)
 {
     _lastExpectedData.clear();

     bool wc_overlap = true;

     // Find the last value read from the location
     const Transaction& last_obs =
         *lastCompletedTransaction(&readObservations, start);
     bool last_obs_valid = (last_obs.complete != TICK_INITIAL);

     // Scan backwards through the write clusters to find the closest younger
     // preceding & overlapping writes.
     for (auto cluster = writeClusters.rbegin();
          cluster != writeClusters.rend() && wc_overlap; ++cluster) {
         for (const auto& addr_write : cluster->writes) {
             const Transaction& write = addr_write.second;

             if (write.complete < last_obs.start) {
                 // If this write transaction completed before the last
                 // observation, we ignore it as the last_observation has the
                 // correct value
                 continue;
             }

             if (write.data == data) {
                 // Found a match, end search.
                 return true;
             }

             // Record possible, but non-matching data for debugging
             _lastExpectedData.push_back(write.data);

             if (write.complete > start) {
                 // This write overlapped with the transaction we want to check
                 // -> continue checking the overlapping write cluster
                 continue;
             }

             // This write cluster has writes that have completed before the
             // checked transaction. There is no need to check an earlier
             // write-cluster -> set the exit condition for the outer loop
             wc_overlap = false;

             if (last_obs.complete < write.start) {
                 // We found a write which started after the last observed read,
                 // therefore we can not longer consider the value seen by the
                 // last observation as a valid expected value.
                 //
                 // Once all writes have been iterated through, we can check if
                 // the last observation is still valid to compare against.
                 last_obs_valid = false;
             }
         }
     }

     // We have not found any matching write, so far; check other sources of
     // confirmation
     if (last_obs_valid) {
         // The last observation is not outdated according to the writes we have
         // seen so far.
         assert(last_obs.complete <= start);
         if (last_obs.data == data) {
             // Matched data from last observation -> all good
             return true;
         }
         // Record non-matching, but possible value
         _lastExpectedData.push_back(last_obs.data);
     } else {
         // We have not seen any valid observation, and the only writes
         // observed are overlapping, so anything (in particular the
         // initialisation value) goes
         // NOTE: We can overlap with multiple write clusters, here
         if (!writeClusters.empty() && wc_overlap) {
             // ensure that all write clusters really overlap this read
             assert(writeClusters.begin()->start < complete &&
                    writeClusters.rbegin()->complete > start);
             return true;
         }
     }

     if (_lastExpectedData.empty()) {
         assert(last_obs.complete == TICK_INITIAL);
         // We have not found any possible (non-matching data). Can happen in
         // initial system state
         DPRINTF(MemChecker, "no last observation nor write! start = %d, "\
                 "complete = %d, data = %#x\n", start, complete, data);
         return true;
     }
     return false;
 }

 bool
 MemChecker::ByteTracker::completeRead(MemChecker::Serial serial,
                                       Tick complete, uint8_t data)
 {
     auto it = outstandingReads.find(serial);

     if (it == outstandingReads.end()) {
         // Can happen if concurrent with reset_address_range
         warn("Could not locate read transaction: serial = %d, complete = %d\n",
              serial, complete);
         return true;
     }

     Tick start = it->second.start;
     outstandingReads.erase(it);

     // Verify data
     const bool result = inExpectedData(start, complete, data);

     readObservations.emplace_back(serial, start, complete, data);
     pruneTransactions();

     return result;
 }

 MemChecker::WriteCluster*
 MemChecker::ByteTracker::getIncompleteWriteCluster()
 {
     if (writeClusters.empty() || writeClusters.back().isComplete()) {
         writeClusters.emplace_back();
     }

     return &writeClusters.back();
 }

 void
 MemChecker::ByteTracker::startWrite(MemChecker::Serial serial, Tick start,
                                     uint8_t data)
 {
     getIncompleteWriteCluster()->startWrite(serial, start, data);
 }

 void
 MemChecker::ByteTracker::completeWrite(MemChecker::Serial serial,
     Tick complete)
 {
     getIncompleteWriteCluster()->completeWrite(serial, complete);
     pruneTransactions();
 }

 void
 MemChecker::ByteTracker::abortWrite(MemChecker::Serial serial)
 {
     getIncompleteWriteCluster()->abortWrite(serial);
 }

 void
 MemChecker::ByteTracker::pruneTransactions()
 {
     // Obtain tick of first outstanding read. If there are no outstanding
     // reads, we use curTick(), i.e. we will remove all readObservation except
     // the most recent one.
     const Tick before = outstandingReads.empty() ? curTick() :
                         outstandingReads.begin()->second.start;

     // Pruning of readObservations
     readObservations.erase(readObservations.begin(),
         lastCompletedTransaction(&readObservations, before));

     // Pruning of writeClusters
     if (!writeClusters.empty()) {
         writeClusters.erase(writeClusters.begin(),
                             lastCompletedTransaction(&writeClusters, before));
     }
 }

 bool
 MemChecker::completeRead(MemChecker::Serial serial, Tick complete,
                          Addr addr, size_t size, uint8_t *data)
 {
     bool result = true;

     DPRINTF(MemChecker,
             "completing read: serial = %d, complete = %d, "
             "addr = %#llx, size = %d\n", serial, complete, addr, size);

     for (size_t i = 0; i < size; ++i) {
         ByteTracker *tracker = getByteTracker(addr + i);

         if (!tracker->completeRead(serial, complete, data[i])) {
             // Generate error message, and aggregate all failures for the bytes
             // considered in this transaction in one message.
             if (result) {
                 result = false;
                 errorMessage = "";
             } else {
                 errorMessage += "\n";
             }

             errorMessage += csprintf("  Read transaction for address %#llx "
                                      "failed: received %#x, expected ",
                                      (unsigned long long)(addr + i), data[i]);

             for (size_t j = 0; j < tracker->lastExpectedData().size(); ++j) {
                 errorMessage +=
                     csprintf("%#x%s",
                              tracker->lastExpectedData()[j],
                              (j == tracker->lastExpectedData().size() - 1)
                              ? "" : "|");
             }
         }
     }

     if (!result) {
         DPRINTF(MemChecker, "read of %#llx @ cycle %d failed:\n%s\n", addr,
                 complete, errorMessage);
     }

     return result;
 }

 void
 MemChecker::reset(Addr addr, size_t size)
 {
     for (size_t i = 0; i < size; ++i) {
         byte_trackers.erase(addr + i);
     }
 }
	/*
	* Copyright (c) 2014 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.
	*
	* 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.
	*/

	#include "mem/mem_checker.hh"

	#include "base/logging.hh"

	void
	MemChecker::WriteCluster::startWrite(MemChecker::Serial serial, Tick _start,
	uint8_t data)
	{
	assert(!isComplete());

	if (start == TICK_FUTURE) {
	// Initialize a fresh write cluster
	start = _start;
	}
	chatty_assert(start <= _start, "WriteClusters must filled in order!");

	++numIncomplete;

	if (complete != TICK_FUTURE) {
	// Reopen a closed write cluster
	assert(_start < complete); // Should open a new write cluster instead
	// Also somewhat fishy wrt causality / ordering of calls vs time
	// progression TODO: Check me!
	complete = TICK_FUTURE;
	}

	// Create new transaction, and denote completion time to be in the future.
	writes.insert(std::make_pair(serial,
	MemChecker::Transaction(serial, _start, TICK_FUTURE, data)));
	}

	void
	MemChecker::WriteCluster::completeWrite(MemChecker::Serial serial,
	Tick _complete)
	{
	auto it = writes.find(serial);

	if (it == writes.end()) {
	warn("Could not locate write transaction: serial = %d, "
	"complete = %d\n", serial, _complete);
	return;
	}

	// Record completion time of the write
	assert(it->second.complete == TICK_FUTURE);
	it->second.complete = _complete;

	// Update max completion time for the cluster
	if (completeMax < _complete) {
	completeMax = _complete;
	}

	if (--numIncomplete == 0) {
	// All writes have completed, this cluster is now complete and will be
	// assigned the max of completion tick values among all writes.
	//
	// Note that we cannot simply keep updating complete, because that
	// would count the cluster as closed already. Instead, we keep
	// TICK_FUTURE until all writes have completed.
	complete = completeMax;
	}
	}

	void
	MemChecker::WriteCluster::abortWrite(MemChecker::Serial serial)
	{
	if (!writes.erase(serial)) {
	warn("Could not locate write transaction: serial = %d\n", serial);
	return;
	}

	if (--numIncomplete == 0 && !writes.empty()) {
	// This write cluster is now complete, and we can assign the current
	// completeMax value.
	complete = completeMax;
	}

	// Note: this WriteCluster is in pristine state if this was the only
	// write present; the cluster will get reused through
	// getIncompleteWriteCluster().
	}

	void
	MemChecker::ByteTracker::startRead(MemChecker::Serial serial, Tick start)
	{
	outstandingReads.insert(std::make_pair(serial,
	MemChecker::Transaction(serial, start, TICK_FUTURE)));
	}

	bool
	MemChecker::ByteTracker::inExpectedData(Tick start, Tick complete,
	uint8_t data)
	{
	_lastExpectedData.clear();

	bool wc_overlap = true;

	// Find the last value read from the location
	const Transaction& last_obs =
	*lastCompletedTransaction(&readObservations, start);
	bool last_obs_valid = (last_obs.complete != TICK_INITIAL);

	// Scan backwards through the write clusters to find the closest younger
	// preceding & overlapping writes.
	for (auto cluster = writeClusters.rbegin();
	cluster != writeClusters.rend() && wc_overlap; ++cluster) {
	for (const auto& addr_write : cluster->writes) {
	const Transaction& write = addr_write.second;

	if (write.complete < last_obs.start) {
	// If this write transaction completed before the last
	// observation, we ignore it as the last_observation has the
	// correct value
	continue;
	}

	if (write.data == data) {
	// Found a match, end search.
	return true;
	}

	// Record possible, but non-matching data for debugging
	_lastExpectedData.push_back(write.data);

	if (write.complete > start) {
	// This write overlapped with the transaction we want to check
	// -> continue checking the overlapping write cluster
	continue;
	}

	// This write cluster has writes that have completed before the
	// checked transaction. There is no need to check an earlier
	// write-cluster -> set the exit condition for the outer loop
	wc_overlap = false;

	if (last_obs.complete < write.start) {
	// We found a write which started after the last observed read,
	// therefore we can not longer consider the value seen by the
	// last observation as a valid expected value.
	//
	// Once all writes have been iterated through, we can check if
	// the last observation is still valid to compare against.
	last_obs_valid = false;
	}
	}
	}

	// We have not found any matching write, so far; check other sources of
	// confirmation
	if (last_obs_valid) {
	// The last observation is not outdated according to the writes we have
	// seen so far.
	assert(last_obs.complete <= start);
	if (last_obs.data == data) {
	// Matched data from last observation -> all good
	return true;
	}
	// Record non-matching, but possible value
	_lastExpectedData.push_back(last_obs.data);
	} else {
	// We have not seen any valid observation, and the only writes
	// observed are overlapping, so anything (in particular the
	// initialisation value) goes
	// NOTE: We can overlap with multiple write clusters, here
	if (!writeClusters.empty() && wc_overlap) {
	// ensure that all write clusters really overlap this read
	assert(writeClusters.begin()->start < complete &&
	writeClusters.rbegin()->complete > start);
	return true;
	}
	}

	if (_lastExpectedData.empty()) {
	assert(last_obs.complete == TICK_INITIAL);
	// We have not found any possible (non-matching data). Can happen in
	// initial system state
	DPRINTF(MemChecker, "no last observation nor write! start = %d, "\
	"complete = %d, data = %#x\n", start, complete, data);
	return true;
	}
	return false;
	}

	bool
	MemChecker::ByteTracker::completeRead(MemChecker::Serial serial,
	Tick complete, uint8_t data)
	{
	auto it = outstandingReads.find(serial);

	if (it == outstandingReads.end()) {
	// Can happen if concurrent with reset_address_range
	warn("Could not locate read transaction: serial = %d, complete = %d\n",
	serial, complete);
	return true;
	}

	Tick start = it->second.start;
	outstandingReads.erase(it);

	// Verify data
	const bool result = inExpectedData(start, complete, data);

	readObservations.emplace_back(serial, start, complete, data);
	pruneTransactions();

	return result;
	}

	MemChecker::WriteCluster*
	MemChecker::ByteTracker::getIncompleteWriteCluster()
	{
	if (writeClusters.empty() \|\| writeClusters.back().isComplete()) {
	writeClusters.emplace_back();
	}

	return &writeClusters.back();
	}

	void
	MemChecker::ByteTracker::startWrite(MemChecker::Serial serial, Tick start,
	uint8_t data)
	{
	getIncompleteWriteCluster()->startWrite(serial, start, data);
	}

	void
	MemChecker::ByteTracker::completeWrite(MemChecker::Serial serial,
	Tick complete)
	{
	getIncompleteWriteCluster()->completeWrite(serial, complete);
	pruneTransactions();
	}

	void
	MemChecker::ByteTracker::abortWrite(MemChecker::Serial serial)
	{
	getIncompleteWriteCluster()->abortWrite(serial);
	}

	void
	MemChecker::ByteTracker::pruneTransactions()
	{
	// Obtain tick of first outstanding read. If there are no outstanding
	// reads, we use curTick(), i.e. we will remove all readObservation except
	// the most recent one.
	const Tick before = outstandingReads.empty() ? curTick() :
	outstandingReads.begin()->second.start;

	// Pruning of readObservations
	readObservations.erase(readObservations.begin(),
	lastCompletedTransaction(&readObservations, before));

	// Pruning of writeClusters
	if (!writeClusters.empty()) {
	writeClusters.erase(writeClusters.begin(),
	lastCompletedTransaction(&writeClusters, before));
	}
	}

	bool
	MemChecker::completeRead(MemChecker::Serial serial, Tick complete,
	Addr addr, size_t size, uint8_t *data)
	{
	bool result = true;

	DPRINTF(MemChecker,
	"completing read: serial = %d, complete = %d, "
	"addr = %#llx, size = %d\n", serial, complete, addr, size);

	for (size_t i = 0; i < size; ++i) {
	ByteTracker *tracker = getByteTracker(addr + i);

	if (!tracker->completeRead(serial, complete, data[i])) {
	// Generate error message, and aggregate all failures for the bytes
	// considered in this transaction in one message.
	if (result) {
	result = false;
	errorMessage = "";
	} else {
	errorMessage += "\n";
	}

	errorMessage += csprintf(" Read transaction for address %#llx "
	"failed: received %#x, expected ",
	(unsigned long long)(addr + i), data[i]);

	for (size_t j = 0; j < tracker->lastExpectedData().size(); ++j) {
	errorMessage +=
	csprintf("%#x%s",
	tracker->lastExpectedData()[j],
	(j == tracker->lastExpectedData().size() - 1)
	? "" : "\|");
	}
	}
	}

	if (!result) {
	DPRINTF(MemChecker, "read of %#llx @ cycle %d failed:\n%s\n", addr,
	complete, errorMessage);
	}

	return result;
	}

	void
	MemChecker::reset(Addr addr, size_t size)
	{
	for (size_t i = 0; i < size; ++i) {
	byte_trackers.erase(addr + i);
	}
	}