gem5/src/cpu/translation.hh
Gabe Black 6833ca7eed Faults: Pass the StaticInst involved, if any, to a Fault's invoke method.
Also move the "Fault" reference counted pointer type into a separate file,
sim/fault.hh. It would be better to name this less similarly to sim/faults.hh
to reduce confusion, but fault.hh matches the name of the type. We could change
Fault to FaultPtr to match other pointer types, and then changing the name of
the file would make more sense.
2010-09-13 19:26:03 -07:00

241 lines
7.7 KiB
C++

/*
* Copyright (c) 2002-2005 The Regents of The University of Michigan
* Copyright (c) 2009 The University of Edinburgh
* 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: Gabe Black
* Timothy M. Jones
*/
#ifndef __CPU_TRANSLATION_HH__
#define __CPU_TRANSLATION_HH__
#include "sim/faults.hh"
#include "sim/tlb.hh"
/**
* This class captures the state of an address translation. A translation
* can be split in two if the ISA supports it and the memory access crosses
* a page boundary. In this case, this class is shared by two data
* translations (below). Otherwise it is used by a single data translation
* class. When each part of the translation is finished, the finish
* function is called which will indicate whether the whole translation is
* completed or not. There are also functions for accessing parts of the
* translation state which deal with the possible split correctly.
*/
class WholeTranslationState
{
protected:
int outstanding;
Fault faults[2];
public:
bool isSplit;
RequestPtr mainReq;
RequestPtr sreqLow;
RequestPtr sreqHigh;
uint8_t *data;
uint64_t *res;
BaseTLB::Mode mode;
/**
* Single translation state. We set the number of outstanding
* translations to one and indicate that it is not split.
*/
WholeTranslationState(RequestPtr _req, uint8_t *_data, uint64_t *_res,
BaseTLB::Mode _mode)
: outstanding(1), isSplit(false), mainReq(_req), sreqLow(NULL),
sreqHigh(NULL), data(_data), res(_res), mode(_mode)
{
faults[0] = faults[1] = NoFault;
assert(mode == BaseTLB::Read || mode == BaseTLB::Write);
}
/**
* Split translation state. We copy all state into this class, set the
* number of outstanding translations to two and then mark this as a
* split translation.
*/
WholeTranslationState(RequestPtr _req, RequestPtr _sreqLow,
RequestPtr _sreqHigh, uint8_t *_data, uint64_t *_res,
BaseTLB::Mode _mode)
: outstanding(2), isSplit(true), mainReq(_req), sreqLow(_sreqLow),
sreqHigh(_sreqHigh), data(_data), res(_res), mode(_mode)
{
faults[0] = faults[1] = NoFault;
assert(mode == BaseTLB::Read || mode == BaseTLB::Write);
}
/**
* Finish part of a translation. If there is only one request then this
* translation is completed. If the request has been split in two then
* the outstanding count determines whether the translation is complete.
* In this case, flags from the split request are copied to the main
* request to make it easier to access them later on.
*/
bool
finish(Fault fault, int index)
{
assert(outstanding);
faults[index] = fault;
outstanding--;
if (isSplit && outstanding == 0) {
// For ease later, we copy some state to the main request.
if (faults[0] == NoFault) {
mainReq->setPaddr(sreqLow->getPaddr());
}
mainReq->setFlags(sreqLow->getFlags());
mainReq->setFlags(sreqHigh->getFlags());
}
return outstanding == 0;
}
/**
* Determine whether this translation produced a fault. Both parts of the
* translation must be checked if this is a split translation.
*/
Fault
getFault() const
{
if (!isSplit)
return faults[0];
else if (faults[0] != NoFault)
return faults[0];
else if (faults[1] != NoFault)
return faults[1];
else
return NoFault;
}
/** Remove all faults from the translation. */
void
setNoFault()
{
faults[0] = faults[1] = NoFault;
}
/**
* Check if this request is uncacheable. We only need to check the main
* request because the flags will have been copied here on a split
* translation.
*/
bool
isUncacheable() const
{
return mainReq->isUncacheable();
}
/**
* Check if this request is a prefetch. We only need to check the main
* request because the flags will have been copied here on a split
* translation.
*/
bool
isPrefetch() const
{
return mainReq->isPrefetch();
}
/** Get the physical address of this request. */
Addr
getPaddr() const
{
return mainReq->getPaddr();
}
/**
* Get the flags associated with this request. We only need to access
* the main request because the flags will have been copied here on a
* split translation.
*/
unsigned
getFlags()
{
return mainReq->getFlags();
}
/** Delete all requests that make up this translation. */
void
deleteReqs()
{
delete mainReq;
if (isSplit) {
delete sreqLow;
delete sreqHigh;
}
}
};
/**
* This class represents part of a data address translation. All state for
* the translation is held in WholeTranslationState (above). Therefore this
* class does not need to know whether the translation is split or not. The
* index variable determines this but is simply passed on to the state class.
* When this part of the translation is completed, finish is called. If the
* translation state class indicate that the whole translation is complete
* then the execution context is informed.
*/
template <class ExecContext>
class DataTranslation : public BaseTLB::Translation
{
protected:
ExecContext *xc;
WholeTranslationState *state;
int index;
public:
DataTranslation(ExecContext *_xc, WholeTranslationState* _state)
: xc(_xc), state(_state), index(0)
{
}
DataTranslation(ExecContext *_xc, WholeTranslationState* _state,
int _index)
: xc(_xc), state(_state), index(_index)
{
}
/**
* Finish this part of the translation and indicate that the whole
* translation is complete if the state says so.
*/
void
finish(Fault fault, RequestPtr req, ThreadContext *tc,
BaseTLB::Mode mode)
{
assert(state);
assert(mode == state->mode);
if (state->finish(fault, index)) {
xc->finishTranslation(state);
}
delete this;
}
};
#endif // __CPU_TRANSLATION_HH__