gem5/cpu/ozone/lw_lsq_impl.hh
Kevin Lim 6b4396111b Updates for OzoneCPU.
cpu/static_inst.hh:
    Updates for new CPU, also include a classification of quiesce instructions.

--HG--
extra : convert_revision : a34cd56da88fe57d7de24674fbb375bbf13f887f
2006-04-22 19:10:39 -04:00

766 lines
21 KiB
C++

/*
* Copyright (c) 2004-2005 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.
*/
#include "arch/isa_traits.hh"
#include "base/str.hh"
#include "cpu/ozone/lw_lsq.hh"
template <class Impl>
OzoneLWLSQ<Impl>::StoreCompletionEvent::StoreCompletionEvent(DynInstPtr &_inst,
BackEnd *_be,
Event *wb_event,
OzoneLWLSQ<Impl> *lsq_ptr)
: Event(&mainEventQueue),
inst(_inst),
be(_be),
wbEvent(wb_event),
lsqPtr(lsq_ptr)
{
this->setFlags(Event::AutoDelete);
}
template <class Impl>
void
OzoneLWLSQ<Impl>::StoreCompletionEvent::process()
{
DPRINTF(OzoneLSQ, "Cache miss complete for store [sn:%lli]\n",
inst->seqNum);
//lsqPtr->removeMSHR(lsqPtr->storeQueue[storeIdx].inst->seqNum);
// lsqPtr->cpu->wakeCPU();
if (wbEvent) {
wbEvent->process();
delete wbEvent;
}
lsqPtr->completeStore(inst->sqIdx);
be->removeDcacheMiss(inst);
}
template <class Impl>
const char *
OzoneLWLSQ<Impl>::StoreCompletionEvent::description()
{
return "LSQ store completion event";
}
template <class Impl>
OzoneLWLSQ<Impl>::OzoneLWLSQ()
: loads(0), stores(0), storesToWB(0), stalled(false), isLoadBlocked(false),
loadBlockedHandled(false)
{
}
template<class Impl>
void
OzoneLWLSQ<Impl>::init(Params *params, unsigned maxLQEntries,
unsigned maxSQEntries, unsigned id)
{
DPRINTF(OzoneLSQ, "Creating OzoneLWLSQ%i object.\n",id);
lsqID = id;
LQEntries = maxLQEntries;
SQEntries = maxSQEntries;
for (int i = 0; i < LQEntries * 10; i++) {
LQIndices.push(i);
SQIndices.push(i);
}
// May want to initialize these entries to NULL
// loadHead = loadTail = 0;
// storeHead = storeWBIdx = storeTail = 0;
usedPorts = 0;
cachePorts = params->cachePorts;
dcacheInterface = params->dcacheInterface;
loadFaultInst = storeFaultInst = memDepViolator = NULL;
blockedLoadSeqNum = 0;
}
template<class Impl>
std::string
OzoneLWLSQ<Impl>::name() const
{
return "lsqunit";
}
template<class Impl>
void
OzoneLWLSQ<Impl>::clearLQ()
{
loadQueue.clear();
}
template<class Impl>
void
OzoneLWLSQ<Impl>::clearSQ()
{
storeQueue.clear();
}
template<class Impl>
void
OzoneLWLSQ<Impl>::setPageTable(PageTable *pt_ptr)
{
DPRINTF(OzoneLSQ, "Setting the page table pointer.\n");
pTable = pt_ptr;
}
template<class Impl>
void
OzoneLWLSQ<Impl>::resizeLQ(unsigned size)
{
assert( size >= LQEntries);
if (size > LQEntries) {
while (size > loadQueue.size()) {
DynInstPtr dummy;
loadQueue.push_back(dummy);
LQEntries++;
}
} else {
LQEntries = size;
}
}
template<class Impl>
void
OzoneLWLSQ<Impl>::resizeSQ(unsigned size)
{
if (size > SQEntries) {
while (size > storeQueue.size()) {
SQEntry dummy;
storeQueue.push_back(dummy);
SQEntries++;
}
} else {
SQEntries = size;
}
}
template <class Impl>
void
OzoneLWLSQ<Impl>::insert(DynInstPtr &inst)
{
// Make sure we really have a memory reference.
assert(inst->isMemRef());
// Make sure it's one of the two classes of memory references.
assert(inst->isLoad() || inst->isStore());
if (inst->isLoad()) {
insertLoad(inst);
} else {
insertStore(inst);
}
// inst->setInLSQ();
}
template <class Impl>
void
OzoneLWLSQ<Impl>::insertLoad(DynInstPtr &load_inst)
{
assert(!LQIndices.empty());
int load_index = LQIndices.front();
LQIndices.pop();
DPRINTF(OzoneLSQ, "Inserting load PC %#x, idx:%i [sn:%lli]\n",
load_inst->readPC(), load_index, load_inst->seqNum);
load_inst->lqIdx = load_index;
loadQueue.push_front(load_inst);
LQItHash[load_index] = loadQueue.begin();
++loads;
}
template <class Impl>
void
OzoneLWLSQ<Impl>::insertStore(DynInstPtr &store_inst)
{
// Make sure it is not full before inserting an instruction.
assert(stores - storesToWB < SQEntries);
assert(!SQIndices.empty());
int store_index = SQIndices.front();
SQIndices.pop();
DPRINTF(OzoneLSQ, "Inserting store PC %#x, idx:%i [sn:%lli]\n",
store_inst->readPC(), store_index, store_inst->seqNum);
store_inst->sqIdx = store_index;
SQEntry entry(store_inst);
if (loadQueue.empty()) {
entry.lqIt = loadQueue.end();
} else {
entry.lqIt = loadQueue.begin();
}
storeQueue.push_front(entry);
SQItHash[store_index] = storeQueue.begin();
++stores;
}
template <class Impl>
typename Impl::DynInstPtr
OzoneLWLSQ<Impl>::getMemDepViolator()
{
DynInstPtr temp = memDepViolator;
memDepViolator = NULL;
return temp;
}
template <class Impl>
unsigned
OzoneLWLSQ<Impl>::numFreeEntries()
{
unsigned free_lq_entries = LQEntries - loads;
unsigned free_sq_entries = SQEntries - stores;
// Both the LQ and SQ entries have an extra dummy entry to differentiate
// empty/full conditions. Subtract 1 from the free entries.
if (free_lq_entries < free_sq_entries) {
return free_lq_entries - 1;
} else {
return free_sq_entries - 1;
}
}
template <class Impl>
int
OzoneLWLSQ<Impl>::numLoadsReady()
{
int retval = 0;
LQIt lq_it = loadQueue.begin();
LQIt end_it = loadQueue.end();
while (lq_it != end_it) {
if ((*lq_it)->readyToIssue()) {
++retval;
}
}
return retval;
}
template <class Impl>
Fault
OzoneLWLSQ<Impl>::executeLoad(DynInstPtr &inst)
{
// Execute a specific load.
Fault load_fault = NoFault;
DPRINTF(OzoneLSQ, "Executing load PC %#x, [sn:%lli]\n",
inst->readPC(),inst->seqNum);
// Make sure it's really in the list.
// Normally it should always be in the list. However,
/* due to a syscall it may not be the list.
#ifdef DEBUG
int i = loadHead;
while (1) {
if (i == loadTail && !find(inst)) {
assert(0 && "Load not in the queue!");
} else if (loadQueue[i] == inst) {
break;
}
i = i + 1;
if (i >= LQEntries) {
i = 0;
}
}
#endif // DEBUG*/
load_fault = inst->initiateAcc();
// Might want to make sure that I'm not overwriting a previously faulting
// instruction that hasn't been checked yet.
// Actually probably want the oldest faulting load
if (load_fault != NoFault) {
DPRINTF(OzoneLSQ, "Load [sn:%lli] has a fault\n", inst->seqNum);
// Maybe just set it as can commit here, although that might cause
// some other problems with sending traps to the ROB too quickly.
be->instToCommit(inst);
// iewStage->activityThisCycle();
}
return load_fault;
}
template <class Impl>
Fault
OzoneLWLSQ<Impl>::executeStore(DynInstPtr &store_inst)
{
// Make sure that a store exists.
assert(stores != 0);
int store_idx = store_inst->sqIdx;
SQHashIt sq_hash_it = SQItHash.find(store_idx);
assert(sq_hash_it != SQItHash.end());
DPRINTF(OzoneLSQ, "Executing store PC %#x [sn:%lli]\n",
store_inst->readPC(), store_inst->seqNum);
SQIt sq_it = (*sq_hash_it).second;
Fault store_fault = store_inst->initiateAcc();
// Store size should now be available. Use it to get proper offset for
// addr comparisons.
int size = (*sq_it).size;
if (size == 0) {
DPRINTF(OzoneLSQ,"Fault on Store PC %#x, [sn:%lli],Size = 0\n",
store_inst->readPC(),store_inst->seqNum);
return store_fault;
}
assert(store_fault == NoFault);
if (!storeFaultInst) {
if (store_fault != NoFault) {
panic("Fault in a store instruction!");
storeFaultInst = store_inst;
} else if (store_inst->isNonSpeculative()) {
// Nonspeculative accesses (namely store conditionals)
// need to set themselves as able to writeback if we
// haven't had a fault by here.
(*sq_it).canWB = true;
++storesToWB;
DPRINTF(OzoneLSQ, "Nonspeculative store! storesToWB:%i\n",
storesToWB);
}
}
LQIt lq_it = --(loadQueue.end());
if (!memDepViolator) {
while (lq_it != loadQueue.end()) {
if ((*lq_it)->seqNum < store_inst->seqNum) {
lq_it--;
continue;
}
// Actually should only check loads that have actually executed
// Might be safe because effAddr is set to InvalAddr when the
// dyn inst is created.
// Must actually check all addrs in the proper size range
// Which is more correct than needs to be. What if for now we just
// assume all loads are quad-word loads, and do the addr based
// on that.
// @todo: Fix this, magic number being used here
if (((*lq_it)->effAddr >> 8) ==
(store_inst->effAddr >> 8)) {
// A load incorrectly passed this store. Squash and refetch.
// For now return a fault to show that it was unsuccessful.
memDepViolator = (*lq_it);
return TheISA::genMachineCheckFault();
}
lq_it--;
}
// If we've reached this point, there was no violation.
memDepViolator = NULL;
}
return store_fault;
}
template <class Impl>
void
OzoneLWLSQ<Impl>::commitLoad()
{
assert(!loadQueue.empty());
DPRINTF(OzoneLSQ, "[sn:%lli] Committing head load instruction, PC %#x\n",
loadQueue.back()->seqNum, loadQueue.back()->readPC());
LQIndices.push(loadQueue.back()->lqIdx);
LQItHash.erase(loadQueue.back()->lqIdx);
loadQueue.pop_back();
--loads;
}
template <class Impl>
void
OzoneLWLSQ<Impl>::commitLoads(InstSeqNum &youngest_inst)
{
assert(loads == 0 || !loadQueue.empty());
while (loads != 0 &&
loadQueue.back()->seqNum <= youngest_inst) {
commitLoad();
}
}
template <class Impl>
void
OzoneLWLSQ<Impl>::commitStores(InstSeqNum &youngest_inst)
{
assert(stores == 0 || !storeQueue.empty());
SQIt sq_it = --(storeQueue.end());
while (!storeQueue.empty() && sq_it != storeQueue.end()) {
assert((*sq_it).inst);
if (!(*sq_it).canWB) {
if ((*sq_it).inst->seqNum > youngest_inst) {
break;
}
++storesToWB;
DPRINTF(OzoneLSQ, "Marking store as able to write back, PC "
"%#x [sn:%lli], storesToWB:%i\n",
(*sq_it).inst->readPC(),
(*sq_it).inst->seqNum,
storesToWB);
(*sq_it).canWB = true;
}
sq_it--;
}
}
template <class Impl>
void
OzoneLWLSQ<Impl>::writebackStores()
{
SQIt sq_it = --(storeQueue.end());
while (storesToWB > 0 &&
sq_it != storeQueue.end() &&
(*sq_it).inst &&
(*sq_it).canWB &&
usedPorts < cachePorts) {
DynInstPtr inst = (*sq_it).inst;
if ((*sq_it).size == 0 && !(*sq_it).completed) {
sq_it--;
completeStore(inst->sqIdx);
continue;
}
if (inst->isDataPrefetch() || (*sq_it).committed) {
sq_it--;
continue;
}
if (dcacheInterface && dcacheInterface->isBlocked()) {
DPRINTF(OzoneLSQ, "Unable to write back any more stores, cache"
" is blocked!\n");
break;
}
++usedPorts;
assert((*sq_it).req);
assert(!(*sq_it).committed);
MemReqPtr req = (*sq_it).req;
(*sq_it).committed = true;
req->cmd = Write;
req->completionEvent = NULL;
req->time = curTick;
assert(!req->data);
req->data = new uint8_t[64];
memcpy(req->data, (uint8_t *)&(*sq_it).data, req->size);
DPRINTF(OzoneLSQ, "D-Cache: Writing back store idx:%i PC:%#x "
"to Addr:%#x, data:%#x [sn:%lli]\n",
inst->sqIdx,inst->readPC(),
req->paddr, *(req->data),
inst->seqNum);
if (dcacheInterface) {
MemAccessResult result = dcacheInterface->access(req);
if (isStalled() &&
inst->seqNum == stallingStoreIsn) {
DPRINTF(OzoneLSQ, "Unstalling, stalling store [sn:%lli] "
"load [sn:%lli]\n",
stallingStoreIsn, (*stallingLoad)->seqNum);
stalled = false;
stallingStoreIsn = 0;
be->replayMemInst((*stallingLoad));
}
if (result != MA_HIT && dcacheInterface->doEvents()) {
// Event *wb = NULL;
typename BackEnd::LdWritebackEvent *wb = NULL;
if (req->flags & LOCKED) {
// Stx_C does not generate a system port transaction.
req->result=1;
wb = new typename BackEnd::LdWritebackEvent(inst,
be);
}
DPRINTF(OzoneLSQ,"D-Cache Write Miss!\n");
// DPRINTF(Activity, "Active st accessing mem miss [sn:%lli]\n",
// inst->seqNum);
// Will stores need their own kind of writeback events?
// Do stores even need writeback events?
assert(!req->completionEvent);
req->completionEvent = new
StoreCompletionEvent(inst, be, wb, this);
be->addDcacheMiss(inst);
lastDcacheStall = curTick;
_status = DcacheMissStall;
// Increment stat here or something
sq_it--;
} else {
DPRINTF(OzoneLSQ,"D-Cache: Write Hit on idx:%i !\n",
inst->sqIdx);
// DPRINTF(Activity, "Active st accessing mem hit [sn:%lli]\n",
// inst->seqNum);
if (req->flags & LOCKED) {
// Stx_C does not generate a system port transaction.
if (req->flags & UNCACHEABLE) {
req->result = 2;
} else {
req->result = 1;
}
typename BackEnd::LdWritebackEvent *wb =
new typename BackEnd::LdWritebackEvent(inst,
be);
wb->schedule(curTick);
}
sq_it--;
completeStore(inst->sqIdx);
}
} else {
panic("Must HAVE DCACHE!!!!!\n");
}
}
// Not sure this should set it to 0.
usedPorts = 0;
assert(stores >= 0 && storesToWB >= 0);
}
template <class Impl>
void
OzoneLWLSQ<Impl>::squash(const InstSeqNum &squashed_num)
{
DPRINTF(OzoneLSQ, "Squashing until [sn:%lli]!"
"(Loads:%i Stores:%i)\n",squashed_num,loads,stores);
LQIt lq_it = loadQueue.begin();
while (loads != 0 && (*lq_it)->seqNum > squashed_num) {
assert(!loadQueue.empty());
// Clear the smart pointer to make sure it is decremented.
DPRINTF(OzoneLSQ,"Load Instruction PC %#x squashed, "
"[sn:%lli]\n",
(*lq_it)->readPC(),
(*lq_it)->seqNum);
if (isStalled() && lq_it == stallingLoad) {
stalled = false;
stallingStoreIsn = 0;
stallingLoad = NULL;
}
--loads;
// Inefficient!
LQHashIt lq_hash_it = LQItHash.find((*lq_it)->lqIdx);
assert(lq_hash_it != LQItHash.end());
LQItHash.erase(lq_hash_it);
LQIndices.push((*lq_it)->lqIdx);
loadQueue.erase(lq_it++);
}
if (isLoadBlocked) {
if (squashed_num < blockedLoadSeqNum) {
isLoadBlocked = false;
loadBlockedHandled = false;
blockedLoadSeqNum = 0;
}
}
SQIt sq_it = storeQueue.begin();
while (stores != 0 && (*sq_it).inst->seqNum > squashed_num) {
assert(!storeQueue.empty());
// Clear the smart pointer to make sure it is decremented.
DPRINTF(OzoneLSQ,"Store Instruction PC %#x idx:%i squashed [sn:%lli]\n",
(*sq_it).inst->readPC(), (*sq_it).inst->sqIdx,
(*sq_it).inst->seqNum);
// I don't think this can happen. It should have been cleared by the
// stalling load.
if (isStalled() &&
(*sq_it).inst->seqNum == stallingStoreIsn) {
panic("Is stalled should have been cleared by stalling load!\n");
stalled = false;
stallingStoreIsn = 0;
}
SQHashIt sq_hash_it = SQItHash.find((*sq_it).inst->sqIdx);
assert(sq_hash_it != SQItHash.end());
SQItHash.erase(sq_hash_it);
SQIndices.push((*sq_it).inst->sqIdx);
(*sq_it).inst = NULL;
(*sq_it).canWB = 0;
if ((*sq_it).req) {
assert(!(*sq_it).req->completionEvent);
}
(*sq_it).req = NULL;
--stores;
storeQueue.erase(sq_it++);
}
}
template <class Impl>
void
OzoneLWLSQ<Impl>::dumpInsts()
{
cprintf("Load store queue: Dumping instructions.\n");
cprintf("Load queue size: %i\n", loads);
cprintf("Load queue: ");
LQIt lq_it = --(loadQueue.end());
while (lq_it != loadQueue.end() && (*lq_it)) {
cprintf("[sn:%lli] %#x ", (*lq_it)->seqNum,
(*lq_it)->readPC());
lq_it--;
}
cprintf("\nStore queue size: %i\n", stores);
cprintf("Store queue: ");
SQIt sq_it = --(storeQueue.end());
while (sq_it != storeQueue.end() && (*sq_it).inst) {
cprintf("[sn:%lli]\nPC:%#x\nSize:%i\nCommitted:%i\nCompleted:%i\ncanWB:%i\n",
(*sq_it).inst->seqNum,
(*sq_it).inst->readPC(),
(*sq_it).size,
(*sq_it).committed,
(*sq_it).completed,
(*sq_it).canWB);
sq_it--;
}
cprintf("\n");
}
template <class Impl>
void
OzoneLWLSQ<Impl>::completeStore(int store_idx)
{
SQHashIt sq_hash_it = SQItHash.find(store_idx);
assert(sq_hash_it != SQItHash.end());
SQIt sq_it = (*sq_hash_it).second;
assert((*sq_it).inst);
(*sq_it).completed = true;
DynInstPtr inst = (*sq_it).inst;
--storesToWB;
if (isStalled() &&
inst->seqNum == stallingStoreIsn) {
DPRINTF(OzoneLSQ, "Unstalling, stalling store [sn:%lli] "
"load [sn:%lli]\n",
stallingStoreIsn, (*stallingLoad)->seqNum);
stalled = false;
stallingStoreIsn = 0;
be->replayMemInst((*stallingLoad));
}
DPRINTF(OzoneLSQ, "Completing store idx:%i [sn:%lli], storesToWB:%i\n",
inst->sqIdx, inst->seqNum, storesToWB);
// A bit conservative because a store completion may not free up entries,
// but hopefully avoids two store completions in one cycle from making
// the CPU tick twice.
// cpu->activityThisCycle();
assert(!storeQueue.empty());
SQItHash.erase(sq_hash_it);
SQIndices.push(inst->sqIdx);
storeQueue.erase(sq_it);
--stores;
/*
SQIt oldest_store_it = --(storeQueue.end());
if (sq_it == oldest_store_it) {
do {
inst = (*oldest_store_it).inst;
sq_hash_it = SQItHash.find(inst->sqIdx);
assert(sq_hash_it != SQItHash.end());
SQItHash.erase(sq_hash_it);
SQIndices.push(inst->sqIdx);
storeQueue.erase(oldest_store_it--);
--stores;
} while ((*oldest_store_it).completed &&
oldest_store_it != storeQueue.end());
// be->updateLSQNextCycle = true;
}
*/
}