diff options
Diffstat (limited to 'src/mem/physical.cc')
-rw-r--r-- | src/mem/physical.cc | 110 |
1 files changed, 97 insertions, 13 deletions
diff --git a/src/mem/physical.cc b/src/mem/physical.cc index 8fea733ec..070693442 100644 --- a/src/mem/physical.cc +++ b/src/mem/physical.cc @@ -110,28 +110,112 @@ PhysicalMemory::calculateLatency(Packet *pkt) return lat; } + + +// Add load-locked to tracking list. Should only be called if the +// operation is a load and the LOCKED flag is set. +void +PhysicalMemory::trackLoadLocked(Request *req) +{ + Addr paddr = LockedAddr::mask(req->getPaddr()); + + // first we check if we already have a locked addr for this + // xc. Since each xc only gets one, we just update the + // existing record with the new address. + list<LockedAddr>::iterator i; + + for (i = lockedAddrList.begin(); i != lockedAddrList.end(); ++i) { + if (i->matchesContext(req)) { + DPRINTF(LLSC, "Modifying lock record: cpu %d thread %d addr %#x\n", + req->getCpuNum(), req->getThreadNum(), paddr); + i->addr = paddr; + return; + } + } + + // no record for this xc: need to allocate a new one + DPRINTF(LLSC, "Adding lock record: cpu %d thread %d addr %#x\n", + req->getCpuNum(), req->getThreadNum(), paddr); + lockedAddrList.push_front(LockedAddr(req)); +} + + +// Called on *writes* only... both regular stores and +// store-conditional operations. Check for conventional stores which +// conflict with locked addresses, and for success/failure of store +// conditionals. +bool +PhysicalMemory::checkLockedAddrList(Request *req) +{ + Addr paddr = LockedAddr::mask(req->getPaddr()); + bool isLocked = req->isLocked(); + + // Initialize return value. Non-conditional stores always + // succeed. Assume conditional stores will fail until proven + // otherwise. + bool success = !isLocked; + + // Iterate over list. Note that there could be multiple matching + // records, as more than one context could have done a load locked + // to this location. + list<LockedAddr>::iterator i = lockedAddrList.begin(); + + while (i != lockedAddrList.end()) { + + if (i->addr == paddr) { + // we have a matching address + + if (isLocked && i->matchesContext(req)) { + // it's a store conditional, and as far as the memory + // system can tell, the requesting context's lock is + // still valid. + DPRINTF(LLSC, "StCond success: cpu %d thread %d addr %#x\n", + req->getCpuNum(), req->getThreadNum(), paddr); + success = true; + } + + // Get rid of our record of this lock and advance to next + DPRINTF(LLSC, "Erasing lock record: cpu %d thread %d addr %#x\n", + i->cpuNum, i->threadNum, paddr); + i = lockedAddrList.erase(i); + } + else { + // no match: advance to next record + ++i; + } + } + + if (isLocked) { + req->setScResult(success ? 1 : 0); + } + + return success; +} + void PhysicalMemory::doFunctionalAccess(Packet *pkt) { assert(pkt->getAddr() + pkt->getSize() < params()->addrRange.size()); - switch (pkt->cmd) { - case Packet::ReadReq: + if (pkt->isRead()) { + if (pkt->req->isLocked()) { + trackLoadLocked(pkt->req); + } memcpy(pkt->getPtr<uint8_t>(), pmemAddr + pkt->getAddr() - params()->addrRange.start, pkt->getSize()); - break; - case Packet::WriteReq: - memcpy(pmemAddr + pkt->getAddr() - params()->addrRange.start, - pkt->getPtr<uint8_t>(), - pkt->getSize()); - // temporary hack: will need to add real LL/SC implementation - // for cacheless systems later. - if (pkt->req->getFlags() & LOCKED) { - pkt->req->setScResult(1); + } + else if (pkt->isWrite()) { + if (writeOK(pkt->req)) { + memcpy(pmemAddr + pkt->getAddr() - params()->addrRange.start, + pkt->getPtr<uint8_t>(), pkt->getSize()); } - break; - default: + } + else if (pkt->isInvalidate()) { + //upgrade or invalidate + pkt->flags |= SATISFIED; + } + else { panic("unimplemented"); } |