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Diffstat (limited to 'cpu/ozone/lsq_unit_impl.hh')
| -rw-r--r-- | cpu/ozone/lsq_unit_impl.hh | 846 |
1 files changed, 846 insertions, 0 deletions
diff --git a/cpu/ozone/lsq_unit_impl.hh b/cpu/ozone/lsq_unit_impl.hh new file mode 100644 index 000000000..726348d76 --- /dev/null +++ b/cpu/ozone/lsq_unit_impl.hh @@ -0,0 +1,846 @@ +/* + * 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/lsq_unit.hh" + +template <class Impl> +OzoneLSQ<Impl>::StoreCompletionEvent::StoreCompletionEvent(int store_idx, + Event *wb_event, + OzoneLSQ<Impl> *lsq_ptr) + : Event(&mainEventQueue), + storeIdx(store_idx), + wbEvent(wb_event), + lsqPtr(lsq_ptr) +{ + this->setFlags(Event::AutoDelete); +} + +template <class Impl> +void +OzoneLSQ<Impl>::StoreCompletionEvent::process() +{ + DPRINTF(OzoneLSQ, "Cache miss complete for store idx:%i\n", storeIdx); + + //lsqPtr->removeMSHR(lsqPtr->storeQueue[storeIdx].inst->seqNum); + +// lsqPtr->cpu->wakeCPU(); + if (wbEvent) + wbEvent->process(); + lsqPtr->completeStore(storeIdx); +} + +template <class Impl> +const char * +OzoneLSQ<Impl>::StoreCompletionEvent::description() +{ + return "LSQ store completion event"; +} + +template <class Impl> +OzoneLSQ<Impl>::OzoneLSQ() + : loads(0), stores(0), storesToWB(0), stalled(false), isLoadBlocked(false) +{ +} + +template<class Impl> +void +OzoneLSQ<Impl>::init(Params *params, unsigned maxLQEntries, + unsigned maxSQEntries, unsigned id) + +{ + DPRINTF(OzoneLSQ, "Creating OzoneLSQ%i object.\n",id); + + lsqID = id; + + LQEntries = maxLQEntries; + SQEntries = maxSQEntries; + + loadQueue.resize(LQEntries); + storeQueue.resize(SQEntries); + + + // 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; +} + +template<class Impl> +std::string +OzoneLSQ<Impl>::name() const +{ + return "lsqunit"; +} + +template<class Impl> +void +OzoneLSQ<Impl>::clearLQ() +{ + loadQueue.clear(); +} + +template<class Impl> +void +OzoneLSQ<Impl>::clearSQ() +{ + storeQueue.clear(); +} + +template<class Impl> +void +OzoneLSQ<Impl>::setPageTable(PageTable *pt_ptr) +{ + DPRINTF(OzoneLSQ, "Setting the page table pointer.\n"); + pTable = pt_ptr; +} + +template<class Impl> +void +OzoneLSQ<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 +OzoneLSQ<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 +OzoneLSQ<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 +OzoneLSQ<Impl>::insertLoad(DynInstPtr &load_inst) +{ + assert((loadTail + 1) % LQEntries != loadHead && loads < LQEntries); + + DPRINTF(OzoneLSQ, "Inserting load PC %#x, idx:%i [sn:%lli]\n", + load_inst->readPC(), loadTail, load_inst->seqNum); + + load_inst->lqIdx = loadTail; + + if (stores == 0) { + load_inst->sqIdx = -1; + } else { + load_inst->sqIdx = storeTail; + } + + loadQueue[loadTail] = load_inst; + + incrLdIdx(loadTail); + + ++loads; +} + +template <class Impl> +void +OzoneLSQ<Impl>::insertStore(DynInstPtr &store_inst) +{ + // Make sure it is not full before inserting an instruction. + assert((storeTail + 1) % SQEntries != storeHead); + assert(stores < SQEntries); + + DPRINTF(OzoneLSQ, "Inserting store PC %#x, idx:%i [sn:%lli]\n", + store_inst->readPC(), storeTail, store_inst->seqNum); + + store_inst->sqIdx = storeTail; + store_inst->lqIdx = loadTail; + + storeQueue[storeTail] = SQEntry(store_inst); + + incrStIdx(storeTail); + + ++stores; + +} + +template <class Impl> +typename Impl::DynInstPtr +OzoneLSQ<Impl>::getMemDepViolator() +{ + DynInstPtr temp = memDepViolator; + + memDepViolator = NULL; + + return temp; +} + +template <class Impl> +unsigned +OzoneLSQ<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 +OzoneLSQ<Impl>::numLoadsReady() +{ + int load_idx = loadHead; + int retval = 0; + + while (load_idx != loadTail) { + assert(loadQueue[load_idx]); + + if (loadQueue[load_idx]->readyToIssue()) { + ++retval; + } + } + + return retval; +} + +#if 0 +template <class Impl> +Fault +OzoneLSQ<Impl>::executeLoad() +{ + Fault load_fault = NoFault; + DynInstPtr load_inst; + + assert(readyLoads.size() != 0); + + // Execute a ready load. + LdMapIt ready_it = readyLoads.begin(); + + load_inst = (*ready_it).second; + + // Execute the instruction, which is held in the data portion of the + // iterator. + load_fault = load_inst->execute(); + + // If it executed successfully, then switch it over to the executed + // loads list. + if (load_fault == NoFault) { + executedLoads[load_inst->seqNum] = load_inst; + + readyLoads.erase(ready_it); + } else { + loadFaultInst = load_inst; + } + + return load_fault; +} +#endif + +template <class Impl> +Fault +OzoneLSQ<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) { + // Maybe just set it as can commit here, although that might cause + // some other problems with sending traps to the ROB too quickly. +// iewStage->instToCommit(inst); +// iewStage->activityThisCycle(); + } + + return load_fault; +} + +template <class Impl> +Fault +OzoneLSQ<Impl>::executeLoad(int lq_idx) +{ + // Very hackish. Not sure the best way to check that this + // instruction is at the head of the ROB. I should have some sort + // of extra information here so that I'm not overloading the + // canCommit signal for 15 different things. + loadQueue[lq_idx]->setCanCommit(); + Fault ret_fault = executeLoad(loadQueue[lq_idx]); + loadQueue[lq_idx]->clearCanCommit(); + return ret_fault; +} + +template <class Impl> +Fault +OzoneLSQ<Impl>::executeStore(DynInstPtr &store_inst) +{ + // Make sure that a store exists. + assert(stores != 0); + + int store_idx = store_inst->sqIdx; + + DPRINTF(OzoneLSQ, "Executing store PC %#x [sn:%lli]\n", + store_inst->readPC(), store_inst->seqNum); + + // Check the recently completed loads to see if any match this store's + // address. If so, then we have a memory ordering violation. + int load_idx = store_inst->lqIdx; + + Fault store_fault = store_inst->initiateAcc(); + + // Store size should now be available. Use it to get proper offset for + // addr comparisons. + int size = storeQueue[store_idx].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. + storeQueue[store_idx].canWB = true; + + ++storesToWB; + } + } + + if (!memDepViolator) { + while (load_idx != loadTail) { + // 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 ((loadQueue[load_idx]->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 = loadQueue[load_idx]; + + return TheISA::genMachineCheckFault(); + } + + incrLdIdx(load_idx); + } + + // If we've reached this point, there was no violation. + memDepViolator = NULL; + } + + return store_fault; +} + +template <class Impl> +void +OzoneLSQ<Impl>::commitLoad() +{ + assert(loadQueue[loadHead]); + + DPRINTF(OzoneLSQ, "[sn:%lli] Committing head load instruction, PC %#x\n", + loadQueue[loadHead]->seqNum, loadQueue[loadHead]->readPC()); + + + loadQueue[loadHead] = NULL; + + incrLdIdx(loadHead); + + --loads; +} + +template <class Impl> +void +OzoneLSQ<Impl>::commitLoad(InstSeqNum &inst) +{ + // Hopefully I don't use this function too much + panic("Don't use this function!"); + + int i = loadHead; + while (1) { + if (i == loadTail) { + assert(0 && "Load not in the queue!"); + } else if (loadQueue[i]->seqNum == inst) { + break; + } + + ++i; + if (i >= LQEntries) { + i = 0; + } + } + +// loadQueue[i]->removeInLSQ(); + loadQueue[i] = NULL; + --loads; +} + +template <class Impl> +void +OzoneLSQ<Impl>::commitLoads(InstSeqNum &youngest_inst) +{ + assert(loads == 0 || loadQueue[loadHead]); + + while (loads != 0 && loadQueue[loadHead]->seqNum <= youngest_inst) { + commitLoad(); + } +} + +template <class Impl> +void +OzoneLSQ<Impl>::commitStores(InstSeqNum &youngest_inst) +{ + assert(stores == 0 || storeQueue[storeHead].inst); + + int store_idx = storeHead; + + while (store_idx != storeTail) { + assert(storeQueue[store_idx].inst); + if (!storeQueue[store_idx].canWB) { + if (storeQueue[store_idx].inst->seqNum > youngest_inst) { + break; + } + DPRINTF(OzoneLSQ, "Marking store as able to write back, PC " + "%#x [sn:%lli]\n", + storeQueue[store_idx].inst->readPC(), + storeQueue[store_idx].inst->seqNum); + + storeQueue[store_idx].canWB = true; + +// --stores; + ++storesToWB; + } + + incrStIdx(store_idx); + } +} + +template <class Impl> +void +OzoneLSQ<Impl>::writebackStores() +{ + while (storesToWB > 0 && + storeWBIdx != storeTail && + storeQueue[storeWBIdx].inst && + storeQueue[storeWBIdx].canWB && + usedPorts < cachePorts) { + + if (storeQueue[storeWBIdx].size == 0) { + completeStore(storeWBIdx); + + incrStIdx(storeWBIdx); + + continue; + } + + if (dcacheInterface && dcacheInterface->isBlocked()) { + DPRINTF(OzoneLSQ, "Unable to write back any more stores, cache" + " is blocked!\n"); + break; + } + + ++usedPorts; + + if (storeQueue[storeWBIdx].inst->isDataPrefetch()) { + incrStIdx(storeWBIdx); + + continue; + } + + assert(storeQueue[storeWBIdx].req); + assert(!storeQueue[storeWBIdx].committed); + + MemReqPtr req = storeQueue[storeWBIdx].req; + storeQueue[storeWBIdx].committed = true; + +// Fault fault = cpu->translateDataReadReq(req); + req->cmd = Write; + req->completionEvent = NULL; + req->time = curTick; + assert(!req->data); + req->data = new uint8_t[64]; + memcpy(req->data, (uint8_t *)&storeQueue[storeWBIdx].data, req->size); + + DPRINTF(OzoneLSQ, "D-Cache: Writing back store idx:%i PC:%#x " + "to Addr:%#x, data:%#x [sn:%lli]\n", + storeWBIdx,storeQueue[storeWBIdx].inst->readPC(), + req->paddr, *(req->data), + storeQueue[storeWBIdx].inst->seqNum); + +// if (fault != NoFault) { + //What should we do if there is a fault??? + //for now panic +// panic("Page Table Fault!!!!!\n"); +// } + + if (dcacheInterface) { + MemAccessResult result = dcacheInterface->access(req); + + //@todo temp fix for LL/SC (works fine for 1 CPU) + if (req->flags & LOCKED) { + req->result=1; + panic("LL/SC! oh no no support!!!"); + } + + if (isStalled() && + storeQueue[storeWBIdx].inst->seqNum == stallingStoreIsn) { + DPRINTF(OzoneLSQ, "Unstalling, stalling store [sn:%lli] " + "load idx:%i\n", + stallingStoreIsn, stallingLoadIdx); + stalled = false; + stallingStoreIsn = 0; + be->replayMemInst(loadQueue[stallingLoadIdx]); + } + + if (result != MA_HIT && dcacheInterface->doEvents()) { + Event *wb = NULL; +/* + typename IEW::LdWritebackEvent *wb = NULL; + if (req->flags & LOCKED) { + // Stx_C does not generate a system port transaction. + req->result=0; + wb = new typename IEW::LdWritebackEvent(storeQueue[storeWBIdx].inst, + iewStage); + } +*/ + DPRINTF(OzoneLSQ,"D-Cache Write Miss!\n"); + +// DPRINTF(Activity, "Active st accessing mem miss [sn:%lli]\n", +// storeQueue[storeWBIdx].inst->seqNum); + + // Will stores need their own kind of writeback events? + // Do stores even need writeback events? + assert(!req->completionEvent); + req->completionEvent = new + StoreCompletionEvent(storeWBIdx, wb, this); + + lastDcacheStall = curTick; + + _status = DcacheMissStall; + + //mshrSeqNums.push_back(storeQueue[storeWBIdx].inst->seqNum); + + //DPRINTF(OzoneLSQ, "Added MSHR. count = %i\n",mshrSeqNums.size()); + + // Increment stat here or something + } else { + DPRINTF(OzoneLSQ,"D-Cache: Write Hit on idx:%i !\n", + storeWBIdx); + +// DPRINTF(Activity, "Active st accessing mem hit [sn:%lli]\n", +// storeQueue[storeWBIdx].inst->seqNum); + + if (req->flags & LOCKED) { + // Stx_C does not generate a system port transaction. + req->result=1; + typename BackEnd::LdWritebackEvent *wb = + new typename BackEnd::LdWritebackEvent(storeQueue[storeWBIdx].inst, + be); + wb->schedule(curTick); + } + + completeStore(storeWBIdx); + } + + incrStIdx(storeWBIdx); + } 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 +OzoneLSQ<Impl>::removeMSHR(InstSeqNum seqNum) +{ + list<InstSeqNum>::iterator mshr_it = find(mshrSeqNums.begin(), + mshrSeqNums.end(), + seqNum); + + if (mshr_it != mshrSeqNums.end()) { + mshrSeqNums.erase(mshr_it); + DPRINTF(OzoneLSQ, "Removing MSHR. count = %i\n",mshrSeqNums.size()); + } +}*/ + +template <class Impl> +void +OzoneLSQ<Impl>::squash(const InstSeqNum &squashed_num) +{ + DPRINTF(OzoneLSQ, "Squashing until [sn:%lli]!" + "(Loads:%i Stores:%i)\n",squashed_num,loads,stores); + + int load_idx = loadTail; + decrLdIdx(load_idx); + + while (loads != 0 && loadQueue[load_idx]->seqNum > squashed_num) { + + // Clear the smart pointer to make sure it is decremented. + DPRINTF(OzoneLSQ,"Load Instruction PC %#x squashed, " + "[sn:%lli]\n", + loadQueue[load_idx]->readPC(), + loadQueue[load_idx]->seqNum); + + if (isStalled() && load_idx == stallingLoadIdx) { + stalled = false; + stallingStoreIsn = 0; + stallingLoadIdx = 0; + } + +// loadQueue[load_idx]->squashed = true; + loadQueue[load_idx] = NULL; + --loads; + + // Inefficient! + loadTail = load_idx; + + decrLdIdx(load_idx); + } + + int store_idx = storeTail; + decrStIdx(store_idx); + + while (stores != 0 && storeQueue[store_idx].inst->seqNum > squashed_num) { + + // Clear the smart pointer to make sure it is decremented. + DPRINTF(OzoneLSQ,"Store Instruction PC %#x squashed, " + "idx:%i [sn:%lli]\n", + storeQueue[store_idx].inst->readPC(), + store_idx, storeQueue[store_idx].inst->seqNum); + + // I don't think this can happen. It should have been cleared by the + // stalling load. + if (isStalled() && + storeQueue[store_idx].inst->seqNum == stallingStoreIsn) { + panic("Is stalled should have been cleared by stalling load!\n"); + stalled = false; + stallingStoreIsn = 0; + } + +// storeQueue[store_idx].inst->squashed = true; + storeQueue[store_idx].inst = NULL; + storeQueue[store_idx].canWB = 0; + + if (storeQueue[store_idx].req) { + assert(!storeQueue[store_idx].req->completionEvent); + } + storeQueue[store_idx].req = NULL; + --stores; + + // Inefficient! + storeTail = store_idx; + + decrStIdx(store_idx); + } +} + +template <class Impl> +void +OzoneLSQ<Impl>::dumpInsts() +{ + cprintf("Load store queue: Dumping instructions.\n"); + cprintf("Load queue size: %i\n", loads); + cprintf("Load queue: "); + + int load_idx = loadHead; + + while (load_idx != loadTail && loadQueue[load_idx]) { + cprintf("[sn:%lli] %#x ", loadQueue[load_idx]->seqNum, + loadQueue[load_idx]->readPC()); + + incrLdIdx(load_idx); + } + + cprintf("\nStore queue size: %i\n", stores); + cprintf("Store queue: "); + + int store_idx = storeHead; + + while (store_idx != storeTail && storeQueue[store_idx].inst) { + cprintf("[sn:%lli] %#x ", storeQueue[store_idx].inst->seqNum, + storeQueue[store_idx].inst->readPC()); + + incrStIdx(store_idx); + } + + cprintf("\n"); +} + +template <class Impl> +void +OzoneLSQ<Impl>::completeStore(int store_idx) +{ + assert(storeQueue[store_idx].inst); + storeQueue[store_idx].completed = true; + --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(); + + if (store_idx == storeHead) { + do { + incrStIdx(storeHead); + + --stores; + } while (storeQueue[storeHead].completed && + storeHead != storeTail); + +// be->updateLSQNextCycle = true; + } + + DPRINTF(OzoneLSQ, "Store head idx:%i\n", storeHead); + + if (isStalled() && + storeQueue[store_idx].inst->seqNum == stallingStoreIsn) { + DPRINTF(OzoneLSQ, "Unstalling, stalling store [sn:%lli] " + "load idx:%i\n", + stallingStoreIsn, stallingLoadIdx); + stalled = false; + stallingStoreIsn = 0; + be->replayMemInst(loadQueue[stallingLoadIdx]); + } +} + +template <class Impl> +inline void +OzoneLSQ<Impl>::incrStIdx(int &store_idx) +{ + if (++store_idx >= SQEntries) + store_idx = 0; +} + +template <class Impl> +inline void +OzoneLSQ<Impl>::decrStIdx(int &store_idx) +{ + if (--store_idx < 0) + store_idx += SQEntries; +} + +template <class Impl> +inline void +OzoneLSQ<Impl>::incrLdIdx(int &load_idx) +{ + if (++load_idx >= LQEntries) + load_idx = 0; +} + +template <class Impl> +inline void +OzoneLSQ<Impl>::decrLdIdx(int &load_idx) +{ + if (--load_idx < 0) + load_idx += LQEntries; +} |