diff options
| -rw-r--r-- | src/mem/cache/base.hh | 4 | ||||
| -rw-r--r-- | src/mem/cache/cache.hh | 11 | ||||
| -rw-r--r-- | src/mem/cache/cache_impl.hh | 36 | ||||
| -rw-r--r-- | src/mem/cache/mshr.cc | 6 | ||||
| -rw-r--r-- | src/mem/cache/mshr.hh | 2 | ||||
| -rw-r--r-- | src/mem/cache/mshr_queue.cc | 4 | ||||
| -rw-r--r-- | src/mem/cache/mshr_queue.hh | 7 |
7 files changed, 44 insertions, 26 deletions
diff --git a/src/mem/cache/base.hh b/src/mem/cache/base.hh index 845a689a4..0be6b7944 100644 --- a/src/mem/cache/base.hh +++ b/src/mem/cache/base.hh @@ -218,11 +218,11 @@ class BaseCache : public MemObject return mshr; } - void markInServiceInternal(MSHR *mshr, PacketPtr pkt) + void markInServiceInternal(MSHR *mshr, bool pending_dirty_resp) { MSHRQueue *mq = mshr->queue; bool wasFull = mq->isFull(); - mq->markInService(mshr, pkt); + mq->markInService(mshr, pending_dirty_resp); if (wasFull && !mq->isFull()) { clearBlocked((BlockedCause)mq->index); } diff --git a/src/mem/cache/cache.hh b/src/mem/cache/cache.hh index e0bd29752..21a00dbbd 100644 --- a/src/mem/cache/cache.hh +++ b/src/mem/cache/cache.hh @@ -375,12 +375,13 @@ class Cache : public BaseCache PacketPtr getTimingPacket(); /** - * Marks a request as in service (sent on the bus). This can have side - * effect since storage for no response commands is deallocated once they - * are successfully sent. - * @param pkt The request that was sent on the bus. + * Marks a request as in service (sent on the bus). This can have + * side effect since storage for no response commands is + * deallocated once they are successfully sent. Also remember if + * we are expecting a dirty response from another cache, + * effectively making this MSHR the ordering point. */ - void markInService(MSHR *mshr, PacketPtr pkt = NULL); + void markInService(MSHR *mshr, bool pending_dirty_resp); /** * Return whether there are any outstanding misses. diff --git a/src/mem/cache/cache_impl.hh b/src/mem/cache/cache_impl.hh index 0dd158afe..9ec0250e1 100644 --- a/src/mem/cache/cache_impl.hh +++ b/src/mem/cache/cache_impl.hh @@ -256,11 +256,9 @@ Cache<TagStore>::satisfyCpuSideRequest(PacketPtr pkt, BlkType *blk, template<class TagStore> void -Cache<TagStore>::markInService(MSHR *mshr, PacketPtr pkt) +Cache<TagStore>::markInService(MSHR *mshr, bool pending_dirty_resp) { - // packet can be either a request or response - - markInServiceInternal(mshr, pkt); + markInServiceInternal(mshr, pending_dirty_resp); #if 0 if (mshr->originalCmd == MemCmd::HardPFReq) { DPRINTF(HWPrefetch, "%s:Marking a HW_PF in service\n", @@ -1745,7 +1743,7 @@ Cache<TagStore>::recvTimingSnoopReq(PacketPtr pkt) if (pkt->isInvalidate()) { // Invalidation trumps our writeback... discard here - markInService(mshr); + markInService(mshr, false); delete wb_pkt; } } // writebacks.size() @@ -1910,9 +1908,10 @@ Cache<TagStore>::getTimingPacket() snoop_pkt.senderState = mshr; cpuSidePort->sendTimingSnoopReq(&snoop_pkt); - // Check to see if the prefetch was squashed by an upper cache - // Or if a writeback arrived between the time the prefetch was - // placed in the MSHRs and when it was selected to send. + // Check to see if the prefetch was squashed by an upper + // cache (to prevent us from grabbing the line) or if a + // writeback arrived between the time the prefetch was + // placed in the MSHRs and when it was selected to be sent. if (snoop_pkt.prefetchSquashed() || blk != NULL) { DPRINTF(Cache, "Prefetch squashed by cache. " "Deallocating mshr target %#x.\n", mshr->addr); @@ -1926,8 +1925,13 @@ Cache<TagStore>::getTimingPacket() return NULL; } + // Check if the prefetch hit a writeback in an upper cache + // and if so we will eventually get a HardPFResp from + // above if (snoop_pkt.memInhibitAsserted()) { - markInService(mshr, &snoop_pkt); + // If we are getting a non-shared response it is dirty + bool pending_dirty_resp = !snoop_pkt.sharedAsserted(); + markInService(mshr, pending_dirty_resp); DPRINTF(Cache, "Upward snoop of prefetch for addr" " %#x (%s) hit\n", tgt_pkt->getAddr(), tgt_pkt->isSecure()? "s": "ns"); @@ -2148,7 +2152,19 @@ Cache<TagStore>::MemSidePacketQueue::sendDeferredPacket() // care about this packet and might override it before // it gets retried } else { - cache.markInService(mshr, pkt); + // As part of the call to sendTimingReq the packet is + // forwarded to all neighbouring caches (and any + // caches above them) as a snoop. The packet is also + // sent to any potential cache below as the + // interconnect is not allowed to buffer the + // packet. Thus at this point we know if any of the + // neighbouring, or the downstream cache is + // responding, and if so, if it is with a dirty line + // or not. + bool pending_dirty_resp = !pkt->sharedAsserted() && + pkt->memInhibitAsserted(); + + cache.markInService(mshr, pending_dirty_resp); } } } diff --git a/src/mem/cache/mshr.cc b/src/mem/cache/mshr.cc index 793db02c2..50196edd1 100644 --- a/src/mem/cache/mshr.cc +++ b/src/mem/cache/mshr.cc @@ -238,7 +238,7 @@ MSHR::clearDownstreamPending() } bool -MSHR::markInService(PacketPtr pkt) +MSHR::markInService(bool pending_dirty_resp) { assert(!inService); if (isForwardNoResponse()) { @@ -249,10 +249,8 @@ MSHR::markInService(PacketPtr pkt) return true; } - assert(pkt != NULL); inService = true; - pendingDirty = targets.needsExclusive || - (!pkt->sharedAsserted() && pkt->memInhibitAsserted()); + pendingDirty = targets.needsExclusive || pending_dirty_resp; postInvalidate = postDowngrade = false; if (!downstreamPending) { diff --git a/src/mem/cache/mshr.hh b/src/mem/cache/mshr.hh index 65357b9e6..c8967d2ea 100644 --- a/src/mem/cache/mshr.hh +++ b/src/mem/cache/mshr.hh @@ -225,7 +225,7 @@ class MSHR : public Packet::SenderState, public Printable void allocate(Addr addr, int size, PacketPtr pkt, Tick when, Counter _order); - bool markInService(PacketPtr pkt); + bool markInService(bool pending_dirty_resp); void clearDownstreamPending(); diff --git a/src/mem/cache/mshr_queue.cc b/src/mem/cache/mshr_queue.cc index cdd6da52c..72e9b2ec3 100644 --- a/src/mem/cache/mshr_queue.cc +++ b/src/mem/cache/mshr_queue.cc @@ -214,9 +214,9 @@ MSHRQueue::moveToFront(MSHR *mshr) } void -MSHRQueue::markInService(MSHR *mshr, PacketPtr pkt) +MSHRQueue::markInService(MSHR *mshr, bool pending_dirty_resp) { - if (mshr->markInService(pkt)) { + if (mshr->markInService(pending_dirty_resp)) { deallocate(mshr); } else { readyList.erase(mshr->readyIter); diff --git a/src/mem/cache/mshr_queue.hh b/src/mem/cache/mshr_queue.hh index 7050421fe..1e1218782 100644 --- a/src/mem/cache/mshr_queue.hh +++ b/src/mem/cache/mshr_queue.hh @@ -183,10 +183,13 @@ class MSHRQueue : public Drainable /** * Mark the given MSHR as in service. This removes the MSHR from the - * readyList. Deallocates the MSHR if it does not expect a response. + * readyList or deallocates the MSHR if it does not expect a response. + * * @param mshr The MSHR to mark in service. + * @param pending_dirty_resp Whether we expect a dirty response + * from another cache */ - void markInService(MSHR *mshr, PacketPtr pkt); + void markInService(MSHR *mshr, bool pending_dirty_resp); /** * Mark an in service entry as pending, used to resend a request. |