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Diffstat (limited to 'src/mem/cache/base_cache.cc')
-rw-r--r--src/mem/cache/base_cache.cc131
1 files changed, 118 insertions, 13 deletions
diff --git a/src/mem/cache/base_cache.cc b/src/mem/cache/base_cache.cc
index a172847df..71ea58416 100644
--- a/src/mem/cache/base_cache.cc
+++ b/src/mem/cache/base_cache.cc
@@ -44,6 +44,8 @@ BaseCache::CachePort::CachePort(const std::string &_name, BaseCache *_cache,
: Port(_name), cache(_cache), isCpuSide(_isCpuSide)
{
blocked = false;
+ cshrRetry = NULL;
+ waitingOnRetry = false;
//Start ports at null if more than one is created we should panic
//cpuSidePort = NULL;
//memSidePort = NULL;
@@ -71,7 +73,23 @@ BaseCache::CachePort::deviceBlockSize()
bool
BaseCache::CachePort::recvTiming(Packet *pkt)
{
- if (blocked)
+ if (isCpuSide
+ && !pkt->req->isUncacheable()
+ && pkt->isInvalidate()
+ && !pkt->isRead() && !pkt->isWrite()) {
+ //Upgrade or Invalidate
+ //Look into what happens if two slave caches on bus
+ DPRINTF(Cache, "%s %x ? blk_addr: %x\n", pkt->cmdString(),
+ pkt->getAddr() & (((ULL(1))<<48)-1),
+ pkt->getAddr() & ~((Addr)cache->blkSize - 1));
+
+ assert(!(pkt->flags & SATISFIED));
+ pkt->flags |= SATISFIED;
+ //Invalidates/Upgrades need no response if they get the bus
+ return true;
+ }
+
+ if (pkt->isRequest() && blocked)
{
DPRINTF(Cache,"Scheduling a retry while blocked\n");
mustSendRetry = true;
@@ -96,16 +114,44 @@ void
BaseCache::CachePort::recvRetry()
{
Packet *pkt;
-
- if (!isCpuSide)
+ assert(waitingOnRetry);
+ if (!drainList.empty()) {
+ DPRINTF(CachePort, "%s attempting to send a retry for response\n", name());
+ //We have some responses to drain first
+ if (sendTiming(drainList.front())) {
+ DPRINTF(CachePort, "%s sucessful in sending a retry for response\n", name());
+ drainList.pop_front();
+ if (!drainList.empty() ||
+ !isCpuSide && cache->doMasterRequest() ||
+ isCpuSide && cache->doSlaveRequest()) {
+
+ DPRINTF(CachePort, "%s has more responses/requests\n", name());
+ BaseCache::CacheEvent * reqCpu = new BaseCache::CacheEvent(this);
+ reqCpu->schedule(curTick + 1);
+ }
+ waitingOnRetry = false;
+ }
+ }
+ else if (!isCpuSide)
{
+ DPRINTF(CachePort, "%s attempting to send a retry for MSHR\n", name());
+ if (!cache->doMasterRequest()) {
+ //This can happen if I am the owner of a block and see an upgrade
+ //while the block was in my WB Buffers. I just remove the
+ //wb and de-assert the masterRequest
+ waitingOnRetry = false;
+ return;
+ }
pkt = cache->getPacket();
+ MSHR* mshr = (MSHR*)pkt->senderState;
bool success = sendTiming(pkt);
DPRINTF(Cache, "Address %x was %s in sending the timing request\n",
pkt->getAddr(), success ? "succesful" : "unsuccesful");
- cache->sendResult(pkt, success);
+ cache->sendResult(pkt, mshr, success);
+ waitingOnRetry = !success;
if (success && cache->doMasterRequest())
{
+ DPRINTF(CachePort, "%s has more requests\n", name());
//Still more to issue, rerequest in 1 cycle
pkt = NULL;
BaseCache::CacheEvent * reqCpu = new BaseCache::CacheEvent(this);
@@ -114,17 +160,23 @@ BaseCache::CachePort::recvRetry()
}
else
{
- pkt = cache->getCoherencePacket();
+ assert(cshrRetry);
+ //pkt = cache->getCoherencePacket();
+ //We save the packet, no reordering on CSHRS
+ pkt = cshrRetry;
bool success = sendTiming(pkt);
+ waitingOnRetry = !success;
if (success && cache->doSlaveRequest())
{
//Still more to issue, rerequest in 1 cycle
pkt = NULL;
BaseCache::CacheEvent * reqCpu = new BaseCache::CacheEvent(this);
reqCpu->schedule(curTick + 1);
+ cshrRetry = NULL;
}
-
}
+ if (waitingOnRetry) DPRINTF(CachePort, "%s STILL Waiting on retry\n", name());
+ else DPRINTF(CachePort, "%s no longer waiting on retry\n", name());
return;
}
void
@@ -169,16 +221,47 @@ BaseCache::CacheEvent::process()
{
if (!pkt)
{
- if (!cachePort->isCpuSide)
- {
- //MSHR
+ if (cachePort->waitingOnRetry) return;
+ //We have some responses to drain first
+ if (!cachePort->drainList.empty()) {
+ DPRINTF(CachePort, "%s trying to drain a response\n", cachePort->name());
+ if (cachePort->sendTiming(cachePort->drainList.front())) {
+ DPRINTF(CachePort, "%s drains a response succesfully\n", cachePort->name());
+ cachePort->drainList.pop_front();
+ if (!cachePort->drainList.empty() ||
+ !cachePort->isCpuSide && cachePort->cache->doMasterRequest() ||
+ cachePort->isCpuSide && cachePort->cache->doSlaveRequest()) {
+
+ DPRINTF(CachePort, "%s still has outstanding bus reqs\n", cachePort->name());
+ this->schedule(curTick + 1);
+ }
+ }
+ else {
+ cachePort->waitingOnRetry = true;
+ DPRINTF(CachePort, "%s now waiting on a retry\n", cachePort->name());
+ }
+ }
+ else if (!cachePort->isCpuSide)
+ { //MSHR
+ DPRINTF(CachePort, "%s trying to send a MSHR request\n", cachePort->name());
+ if (!cachePort->cache->doMasterRequest()) {
+ //This can happen if I am the owner of a block and see an upgrade
+ //while the block was in my WB Buffers. I just remove the
+ //wb and de-assert the masterRequest
+ return;
+ }
+
pkt = cachePort->cache->getPacket();
+ MSHR* mshr = (MSHR*) pkt->senderState;
bool success = cachePort->sendTiming(pkt);
DPRINTF(Cache, "Address %x was %s in sending the timing request\n",
pkt->getAddr(), success ? "succesful" : "unsuccesful");
- cachePort->cache->sendResult(pkt, success);
+ cachePort->cache->sendResult(pkt, mshr, success);
+ cachePort->waitingOnRetry = !success;
+ if (cachePort->waitingOnRetry) DPRINTF(CachePort, "%s now waiting on a retry\n", cachePort->name());
if (success && cachePort->cache->doMasterRequest())
{
+ DPRINTF(CachePort, "%s still more MSHR requests to send\n", cachePort->name());
//Still more to issue, rerequest in 1 cycle
pkt = NULL;
this->schedule(curTick+1);
@@ -186,10 +269,16 @@ BaseCache::CacheEvent::process()
}
else
{
+ assert(cachePort->cache->doSlaveRequest());
//CSHR
pkt = cachePort->cache->getCoherencePacket();
bool success = cachePort->sendTiming(pkt);
- if (success && cachePort->cache->doSlaveRequest())
+ if (!success) {
+ //Need to send on a retry
+ cachePort->cshrRetry = pkt;
+ cachePort->waitingOnRetry = true;
+ }
+ else if (cachePort->cache->doSlaveRequest())
{
//Still more to issue, rerequest in 1 cycle
pkt = NULL;
@@ -199,8 +288,24 @@ BaseCache::CacheEvent::process()
return;
}
//Response
- //Know the packet to send, no need to mark in service (must succed)
- assert(cachePort->sendTiming(pkt));
+ //Know the packet to send
+ if (pkt->flags & NACKED_LINE)
+ pkt->result = Packet::Nacked;
+ else
+ pkt->result = Packet::Success;
+ pkt->makeTimingResponse();
+ DPRINTF(CachePort, "%s attempting to send a response\n", cachePort->name());
+ if (!cachePort->drainList.empty() || cachePort->waitingOnRetry) {
+ //Already have a list, just append
+ cachePort->drainList.push_back(pkt);
+ DPRINTF(CachePort, "%s appending response onto drain list\n", cachePort->name());
+ }
+ else if (!cachePort->sendTiming(pkt)) {
+ //It failed, save it to list of drain events
+ DPRINTF(CachePort, "%s now waiting for a retry\n", cachePort->name());
+ cachePort->drainList.push_back(pkt);
+ cachePort->waitingOnRetry = true;
+ }
}
const char *
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-17 04:24:52 +0000