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Mem: Make errors in the memory system be responses, not requests. Fixes cache handling of error responses.

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--HG--
extra : convert_revision : 22309fc61bd1be0f8d31a3926f290290789a37e5
This commit is contained in:
Ali Saidi 2007-08-24 16:39:24 -04:00
parent e1054170b5
commit 4e89518817
13 changed files with 69 additions and 35 deletions
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2
src/cpu/o3/fetch_impl.hh
View file

@ -364,6 +364,8 @@ DefaultFetch<Impl>::processCacheCompletion(PacketPtr pkt)
DPRINTF(Fetch, "[tid:%u] Waking up from cache miss.\n",tid);
assert(!pkt->wasNacked());
// Only change the status if it's still waiting on the icache access
// to return.
if (fetchStatus[tid] != IcacheWaitResponse ||

2
src/cpu/o3/lsq_impl.hh
View file

@ -80,6 +80,8 @@ template <class Impl>
bool
LSQ<Impl>::DcachePort::recvTiming(PacketPtr pkt)
{
if (pkt->isError())
DPRINTF(LSQ, "Got error packet back for address: %#X\n", pkt->getAddr());
if (pkt->isResponse()) {
lsq->thread[pkt->req->getThreadNum()].completeDataAccess(pkt);
}

2
src/cpu/o3/lsq_unit_impl.hh
View file

@ -83,6 +83,8 @@ LSQUnit<Impl>::completeDataAccess(PacketPtr pkt)
//iewStage->ldstQueue.removeMSHR(inst->threadNumber,inst->seqNum);
assert(!pkt->wasNacked());
if (isSwitchedOut() || inst->isSquashed()) {
iewStage->decrWb(inst->seqNum);
} else {

2
src/cpu/simple/atomic.cc
View file

@ -311,6 +311,7 @@ AtomicSimpleCPU::read(Addr addr, T &data, unsigned flags)
dcache_latency = dcachePort.sendAtomic(&pkt);
}
dcache_access = true;
assert(!pkt.isError());
data = gtoh(data);
@ -536,6 +537,7 @@ AtomicSimpleCPU::tick()
else
icache_latency = icachePort.sendAtomic(&ifetch_pkt);
assert(!ifetch_pkt.isError());
// ifetch_req is initialized to read the instruction directly
// into the CPU object's inst field.

4
src/cpu/simple/timing.cc
View file

@ -564,7 +564,7 @@ TimingSimpleCPU::IcachePort::ITickEvent::process()
bool
TimingSimpleCPU::IcachePort::recvTiming(PacketPtr pkt)
{
if (pkt->isResponse()) {
if (pkt->isResponse() && !pkt->wasNacked()) {
// delay processing of returned data until next CPU clock edge
Tick next_tick = cpu->nextCycle(curTick);
@ -658,7 +658,7 @@ TimingSimpleCPU::DcachePort::setPeer(Port *port)
bool
TimingSimpleCPU::DcachePort::recvTiming(PacketPtr pkt)
{
if (pkt->isResponse()) {
if (pkt->isResponse() && !pkt->wasNacked()) {
// delay processing of returned data until next CPU clock edge
Tick next_tick = cpu->nextCycle(curTick);

2
src/dev/alpha/console.cc
View file

@ -107,6 +107,7 @@ AlphaConsole::read(PacketPtr pkt)
Addr daddr = pkt->getAddr() - pioAddr;
pkt->allocate();
pkt->makeAtomicResponse();
switch (pkt->getSize())
{
@ -188,7 +189,6 @@ AlphaConsole::read(PacketPtr pkt)
default:
pkt->setBadAddress();
}
pkt->makeAtomicResponse();
return pioDelay;
}

4
src/dev/isa_fake.cc
View file

@ -56,6 +56,7 @@ Tick
IsaFake::read(PacketPtr pkt)
{
pkt->makeAtomicResponse();
if (params()->warn_access != "")
warn("Device %s accessed by read to address %#x size=%d\n",
name(), pkt->getAddr(), pkt->getSize());
@ -83,7 +84,6 @@ IsaFake::read(PacketPtr pkt)
default:
panic("invalid access size!\n");
}
pkt->makeAtomicResponse();
}
return pioDelay;
}
@ -91,6 +91,7 @@ IsaFake::read(PacketPtr pkt)
Tick
IsaFake::write(PacketPtr pkt)
{
pkt->makeAtomicResponse();
if (params()->warn_access != "") {
uint64_t data;
switch (pkt->getSize()) {
@ -138,7 +139,6 @@ IsaFake::write(PacketPtr pkt)
panic("invalid access size!\n");
}
}
pkt->makeAtomicResponse();
}
return pioDelay;
}

40
src/mem/bridge.cc
View file

@ -119,17 +119,17 @@ Bridge::BridgePort::recvTiming(PacketPtr pkt)
DPRINTF(BusBridge, "Local queue size: %d outreq: %d outresp: %d\n",
sendQueue.size(), queuedRequests, outstandingResponses);
DPRINTF(BusBridge, "Remove queue size: %d outreq: %d outresp: %d\n",
DPRINTF(BusBridge, "Remote queue size: %d outreq: %d outresp: %d\n",
otherPort->sendQueue.size(), otherPort->queuedRequests,
otherPort->outstandingResponses);
if (pkt->isRequest() && otherPort->reqQueueFull() && !pkt->wasNacked()) {
if (pkt->isRequest() && otherPort->reqQueueFull()) {
DPRINTF(BusBridge, "Remote queue full, nacking\n");
nackRequest(pkt);
return true;
}
if (pkt->needsResponse() && !pkt->wasNacked())
if (pkt->needsResponse())
if (respQueueFull()) {
DPRINTF(BusBridge, "Local queue full, no space for response, nacking\n");
DPRINTF(BusBridge, "queue size: %d outreq: %d outstanding resp: %d\n",
@ -150,8 +150,8 @@ void
Bridge::BridgePort::nackRequest(PacketPtr pkt)
{
// Nack the packet
pkt->makeTimingResponse();
pkt->setNacked();
pkt->setDest(pkt->getSrc());
//put it on the list to send
Tick readyTime = curTick + nackDelay;
@ -195,27 +195,23 @@ Bridge::BridgePort::nackRequest(PacketPtr pkt)
void
Bridge::BridgePort::queueForSendTiming(PacketPtr pkt)
{
if (pkt->isResponse() || pkt->wasNacked()) {
if (pkt->isResponse()) {
// This is a response for a request we forwarded earlier. The
// corresponding PacketBuffer should be stored in the packet's
// senderState field.
PacketBuffer *buf = dynamic_cast<PacketBuffer*>(pkt->senderState);
assert(buf != NULL);
// set up new packet dest & senderState based on values saved
// from original request
buf->fixResponse(pkt);
// Check if this packet was expecting a response and it's a nacked
// packet, in which case we will never being seeing it
if (buf->expectResponse && pkt->wasNacked())
--outstandingResponses;
DPRINTF(BusBridge, "response, new dest %d\n", pkt->getDest());
delete buf;
}
if (pkt->isRequest() && !pkt->wasNacked()) {
if (pkt->isRequest()) {
++queuedRequests;
}
@ -249,7 +245,15 @@ Bridge::BridgePort::trySend()
buf->origSrc, pkt->getDest(), pkt->getAddr());
bool wasReq = pkt->isRequest();
bool wasNacked = pkt->wasNacked();
bool was_nacked_here = buf->nackedHere;
// If the send was successful, make sure sender state was set to NULL
// otherwise we could get a NACK back of a packet that didn't expect a
// response and we would try to use freed memory.
Packet::SenderState *old_sender_state = pkt->senderState;
if (pkt->isRequest() && !buf->expectResponse)
pkt->senderState = NULL;
if (sendTiming(pkt)) {
// send successful
@ -266,12 +270,10 @@ Bridge::BridgePort::trySend()
delete buf;
}
if (!wasNacked) {
if (wasReq)
--queuedRequests;
else
--outstandingResponses;
}
if (wasReq)
--queuedRequests;
else if (!was_nacked_here)
--outstandingResponses;
// If there are more packets to send, schedule event to try again.
if (!sendQueue.empty()) {
@ -281,8 +283,10 @@ Bridge::BridgePort::trySend()
}
} else {
DPRINTF(BusBridge, " unsuccessful\n");
pkt->senderState = old_sender_state;
inRetry = true;
}
DPRINTF(BusBridge, "trySend: queue size: %d outreq: %d outstanding resp: %d\n",
sendQueue.size(), queuedRequests, outstandingResponses);
}

8
src/mem/bridge.hh
View file

@ -78,17 +78,19 @@ class Bridge : public MemObject
public:
Tick ready;
PacketPtr pkt;
bool nackedHere;
Packet::SenderState *origSenderState;
short origSrc;
bool expectResponse;
PacketBuffer(PacketPtr _pkt, Tick t, bool nack = false)
: ready(t), pkt(_pkt),
origSenderState(_pkt->senderState), origSrc(_pkt->getSrc()),
: ready(t), pkt(_pkt), nackedHere(nack),
origSenderState(_pkt->senderState),
origSrc(nack ? _pkt->getDest() : _pkt->getSrc() ),
expectResponse(_pkt->needsResponse() && !nack)
{
if (!pkt->isResponse() && !nack && !pkt->wasNacked())
if (!pkt->isResponse() && !nack)
pkt->senderState = this;
}

1
src/mem/bus.cc
View file

@ -237,6 +237,7 @@ Bus::recvTiming(PacketPtr pkt)
if (dest_port_id == src) {
// Must be forwarded snoop up from below...
assert(dest == Packet::Broadcast);
assert(src != defaultId); // catch infinite loops
} else {
// send to actual target
if (!dest_port->sendTiming(pkt)) {

25
src/mem/cache/cache_impl.hh vendored
View file

@ -606,7 +606,13 @@ Cache<TagStore>::atomicAccess(PacketPtr pkt)
DPRINTF(Cache, "Receive response: %s for addr %x in state %i\n",
busPkt->cmdString(), busPkt->getAddr(), old_state);
if (isCacheFill) {
bool is_error = busPkt->isError();
assert(!busPkt->wasNacked());
if (is_error && pkt->needsResponse()) {
pkt->makeAtomicResponse();
pkt->copyError(busPkt);
} else if (isCacheFill && !is_error) {
PacketList writebacks;
blk = handleFill(busPkt, blk, writebacks);
satisfyCpuSideRequest(pkt, blk);
@ -667,6 +673,8 @@ Cache<TagStore>::handleResponse(PacketPtr pkt)
{
Tick time = curTick + hitLatency;
MSHR *mshr = dynamic_cast<MSHR*>(pkt->senderState);
bool is_error = pkt->isError();
assert(mshr);
if (pkt->wasNacked()) {
@ -675,7 +683,11 @@ Cache<TagStore>::handleResponse(PacketPtr pkt)
"not implemented\n");
return;
}
assert(!pkt->isError());
if (is_error) {
DPRINTF(Cache, "Cache received packet with error for address %x, "
"cmd: %s\n", pkt->getAddr(), pkt->cmdString());
}
DPRINTF(Cache, "Handling response to %x\n", pkt->getAddr());
MSHRQueue *mq = mshr->queue;
@ -702,7 +714,7 @@ Cache<TagStore>::handleResponse(PacketPtr pkt)
miss_latency;
}
if (mshr->isCacheFill) {
if (mshr->isCacheFill && !is_error) {
DPRINTF(Cache, "Block for addr %x being updated in Cache\n",
pkt->getAddr());
@ -744,13 +756,18 @@ Cache<TagStore>::handleResponse(PacketPtr pkt)
} else {
// not a cache fill, just forwarding response
completion_time = tags->getHitLatency() + pkt->finishTime;
if (pkt->isRead()) {
if (pkt->isRead() && !is_error) {
target->pkt->setData(pkt->getPtr<uint8_t>());
}
}
target->pkt->makeTimingResponse();
// if this packet is an error copy that to the new packet
if (is_error)
target->pkt->copyError(pkt);
cpuSidePort->respond(target->pkt, completion_time);
} else {
// I don't believe that a snoop can be in an error state
assert(!is_error);
// response to snoop request
DPRINTF(Cache, "processing deferred snoop...\n");
handleSnoop(target->pkt, blk, true, true);

6
src/mem/packet.cc
View file

@ -117,11 +117,11 @@ MemCmd::commandInfo[] =
{ SET5(IsRead, IsWrite, NeedsExclusive, IsResponse, HasData),
InvalidCmd, "SwapResp" },
/* NetworkNackError -- nacked at network layer (not by protocol) */
{ SET2(IsRequest, IsError), InvalidCmd, "NetworkNackError" },
{ SET2(IsResponse, IsError), InvalidCmd, "NetworkNackError" },
/* InvalidDestError -- packet dest field invalid */
{ SET2(IsRequest, IsError), InvalidCmd, "InvalidDestError" },
{ SET2(IsResponse, IsError), InvalidCmd, "InvalidDestError" },
/* BadAddressError -- memory address invalid */
{ SET2(IsRequest, IsError), InvalidCmd, "BadAddressError" }
{ SET2(IsResponse, IsError), InvalidCmd, "BadAddressError" }
};

6
src/mem/packet.hh
View file

@ -332,10 +332,11 @@ class Packet : public FastAlloc
// Network error conditions... encapsulate them as methods since
// their encoding keeps changing (from result field to command
// field, etc.)
void setNacked() { origCmd = cmd; cmd = MemCmd::NetworkNackError; }
void setBadAddress() { origCmd = cmd; cmd = MemCmd::BadAddressError; }
void setNacked() { assert(isResponse()); cmd = MemCmd::NetworkNackError; }
void setBadAddress() { assert(isResponse()); cmd = MemCmd::BadAddressError; }
bool wasNacked() { return cmd == MemCmd::NetworkNackError; }
bool hadBadAddress() { return cmd == MemCmd::BadAddressError; }
void copyError(Packet *pkt) { assert(pkt->isError()); cmd = pkt->cmd; }
bool nic_pkt() { panic("Unimplemented"); M5_DUMMY_RETURN }
@ -431,6 +432,7 @@ class Packet : public FastAlloc
{
assert(needsResponse());
assert(isRequest());
origCmd = cmd;
cmd = cmd.responseCommand();
dest = src;
destValid = srcValid;