Bridge::BridgePort::BridgePort(const std::string &_name,
Bridge *_bridge, BridgePort *_otherPort,
- int _delay, int _queueLimit,
- bool fix_partial_write)
+ int _delay, int _nack_delay, int _req_limit,
+ int _resp_limit, bool fix_partial_write)
: Port(_name), bridge(_bridge), otherPort(_otherPort),
- delay(_delay), fixPartialWrite(fix_partial_write),
- outstandingResponses(0), queuedRequests(0),
- queueLimit(_queueLimit), sendEvent(this)
+ delay(_delay), nackDelay(_nack_delay), fixPartialWrite(fix_partial_write),
+ outstandingResponses(0), queuedRequests(0), inRetry(false),
+ reqQueueLimit(_req_limit), respQueueLimit(_resp_limit), sendEvent(this)
{
}
-Bridge::Bridge(const std::string &n, int qsa, int qsb,
- Tick _delay, int write_ack, bool fix_partial_write_a,
- bool fix_partial_write_b)
- : MemObject(n),
- portA(n + "-portA", this, &portB, _delay, qsa, fix_partial_write_a),
- portB(n + "-portB", this, &portA, _delay, qsa, fix_partial_write_b),
- ackWrites(write_ack)
+Bridge::Bridge(Params *p)
+ : MemObject(p->name),
+ portA(p->name + "-portA", this, &portB, p->delay, p->nack_delay,
+ p->req_size_a, p->resp_size_a, p->fix_partial_write_a),
+ portB(p->name + "-portB", this, &portA, p->delay, p->nack_delay,
+ p->req_size_b, p->resp_size_b, p->fix_partial_write_b),
+ ackWrites(p->write_ack), _params(p)
{
if (ackWrites)
panic("No support for acknowledging writes\n");
}
bool
-Bridge::BridgePort::queueFull()
+Bridge::BridgePort::respQueueFull()
{
- // use >= here because sendQueue could get larger because of
- // nacks getting inserted
- return queuedRequests + outstandingResponses >= queueLimit;
+ assert(outstandingResponses >= 0 && outstandingResponses <= respQueueLimit);
+ return outstandingResponses >= respQueueLimit;
+}
+
+bool
+Bridge::BridgePort::reqQueueFull()
+{
+ assert(queuedRequests >= 0 && queuedRequests <= reqQueueLimit);
+ return queuedRequests >= reqQueueLimit;
}
/** Function called by the port when the bus is receiving a Timing
bool
Bridge::BridgePort::recvTiming(PacketPtr pkt)
{
- if (!(pkt->flags & SNOOP_COMMIT))
- return true;
-
-
DPRINTF(BusBridge, "recvTiming: src %d dest %d addr 0x%x\n",
pkt->getSrc(), pkt->getDest(), pkt->getAddr());
- if (pkt->isRequest() && otherPort->queueFull()) {
+ 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",
+ otherPort->sendQueue.size(), otherPort->queuedRequests,
+ otherPort->outstandingResponses);
+
+ if (pkt->isRequest() && otherPort->reqQueueFull() && !pkt->wasNacked()) {
DPRINTF(BusBridge, "Remote queue full, nacking\n");
nackRequest(pkt);
return true;
}
- if (pkt->needsResponse() && pkt->result != Packet::Nacked)
- if (queueFull()) {
+ if (pkt->needsResponse() && !pkt->wasNacked())
+ if (respQueueFull()) {
DPRINTF(BusBridge, "Local queue full, no space for response, nacking\n");
DPRINTF(BusBridge, "queue size: %d outreq: %d outstanding resp: %d\n",
sendQueue.size(), queuedRequests, outstandingResponses);
Bridge::BridgePort::nackRequest(PacketPtr pkt)
{
// Nack the packet
- pkt->result = Packet::Nacked;
+ pkt->setNacked();
pkt->setDest(pkt->getSrc());
//put it on the list to send
- Tick readyTime = curTick + delay;
+ Tick readyTime = curTick + nackDelay;
PacketBuffer *buf = new PacketBuffer(pkt, readyTime, true);
+
+ // nothing on the list, add it and we're done
if (sendQueue.empty()) {
+ assert(!sendEvent.scheduled());
sendEvent.schedule(readyTime);
+ sendQueue.push_back(buf);
+ return;
}
- sendQueue.push_back(buf);
+
+ assert(sendEvent.scheduled() || inRetry);
+
+ // does it go at the end?
+ if (readyTime >= sendQueue.back()->ready) {
+ sendQueue.push_back(buf);
+ return;
+ }
+
+ // ok, somewhere in the middle, fun
+ std::list<PacketBuffer*>::iterator i = sendQueue.begin();
+ std::list<PacketBuffer*>::iterator end = sendQueue.end();
+ std::list<PacketBuffer*>::iterator begin = sendQueue.begin();
+ bool done = false;
+
+ while (i != end && !done) {
+ if (readyTime < (*i)->ready) {
+ if (i == begin)
+ sendEvent.reschedule(readyTime);
+ sendQueue.insert(i,buf);
+ done = true;
+ }
+ i++;
+ }
+ assert(done);
}
void
Bridge::BridgePort::queueForSendTiming(PacketPtr pkt)
{
- if (pkt->isResponse() || pkt->result == Packet::Nacked) {
+ if (pkt->isResponse() || pkt->wasNacked()) {
// This is a response for a request we forwarded earlier. The
// corresponding PacketBuffer should be stored in the packet's
// senderState field.
// from original request
buf->fixResponse(pkt);
- // Check if this packet was expecting a response (this is either it or
- // its a nacked packet and we won't be seeing that response)
- if (buf->expectResponse)
+ // 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, "restoring sender state: %#X, from packet buffer: %#X\n",
- pkt->senderState, buf);
- DPRINTF(BusBridge, " is response, new dest %d\n", pkt->getDest());
+ DPRINTF(BusBridge, "response, new dest %d\n", pkt->getDest());
delete buf;
}
+
+ if (pkt->isRequest() && !pkt->wasNacked()) {
+ ++queuedRequests;
+ }
+
+
+
Tick readyTime = curTick + delay;
PacketBuffer *buf = new PacketBuffer(pkt, readyTime);
- DPRINTF(BusBridge, "old sender state: %#X, new sender state: %#X\n",
- buf->origSenderState, buf);
// If we're about to put this packet at the head of the queue, we
// need to schedule an event to do the transmit. Otherwise there
if (sendQueue.empty()) {
sendEvent.schedule(readyTime);
}
- ++queuedRequests;
sendQueue.push_back(buf);
}
{
assert(!sendQueue.empty());
- bool was_full = queueFull();
- int pbs = peerBlockSize();
-
PacketBuffer *buf = sendQueue.front();
assert(buf->ready <= curTick);
PacketPtr pkt = buf->pkt;
- pkt->flags &= ~SNOOP_COMMIT; //CLear it if it was set
-
+ // Ugly! @todo When multilevel coherence works this will be removed
if (pkt->cmd == MemCmd::WriteInvalidateReq && fixPartialWrite &&
- pkt->result != Packet::Nacked && pkt->getOffset(pbs) &&
- pkt->getSize() != pbs) {
- buf->partialWriteFix(this);
- pkt = buf->pkt;
+ !pkt->wasNacked()) {
+ PacketPtr funcPkt = new Packet(pkt->req, MemCmd::WriteReq,
+ Packet::Broadcast);
+ funcPkt->dataStatic(pkt->getPtr<uint8_t>());
+ sendFunctional(funcPkt);
+ pkt->cmd = MemCmd::WriteReq;
+ delete funcPkt;
}
DPRINTF(BusBridge, "trySend: origSrc %d dest %d addr 0x%x\n",
buf->origSrc, pkt->getDest(), pkt->getAddr());
+ bool wasReq = pkt->isRequest();
+ bool wasNacked = pkt->wasNacked();
if (sendTiming(pkt)) {
// send successful
delete buf;
}
- if (!buf->nacked)
+ if (!wasNacked) {
+ if (wasReq)
--queuedRequests;
+ else
+ --outstandingResponses;
+ }
// If there are more packets to send, schedule event to try again.
if (!sendQueue.empty()) {
DPRINTF(BusBridge, "Scheduling next send\n");
sendEvent.schedule(std::max(buf->ready, curTick + 1));
}
- // Let things start sending again
- if (was_full && !queueFull()) {
- DPRINTF(BusBridge, "Queue was full, sending retry\n");
- otherPort->sendRetry();
- }
-
} else {
DPRINTF(BusBridge, " unsuccessful\n");
- buf->undoPartialWriteFix();
+ inRetry = true;
}
DPRINTF(BusBridge, "trySend: queue size: %d outreq: %d outstanding resp: %d\n",
sendQueue.size(), queuedRequests, outstandingResponses);
void
Bridge::BridgePort::recvRetry()
{
- trySend();
+ inRetry = false;
+ Tick nextReady = sendQueue.front()->ready;
+ if (nextReady <= curTick)
+ trySend();
+ else
+ sendEvent.schedule(nextReady);
}
/** Function called by the port when the bus is receiving a Atomic
Tick
Bridge::BridgePort::recvAtomic(PacketPtr pkt)
{
- return otherPort->sendAtomic(pkt) + delay;
+ // fix partial atomic writes... similar to the timing code that does the
+ // same... will be removed once our code gets this right
+ if (pkt->cmd == MemCmd::WriteInvalidateReq && fixPartialWrite) {
+
+ PacketPtr funcPkt = new Packet(pkt->req, MemCmd::WriteReq,
+ Packet::Broadcast);
+ funcPkt->dataStatic(pkt->getPtr<uint8_t>());
+ otherPort->sendFunctional(funcPkt);
+ delete funcPkt;
+ pkt->cmd = MemCmd::WriteReq;
+ }
+ return delay + otherPort->sendAtomic(pkt);
}
/** Function called by the port when the bus is receiving a Functional
Bridge::BridgePort::recvFunctional(PacketPtr pkt)
{
std::list<PacketBuffer*>::iterator i;
- bool pktContinue = true;
for (i = sendQueue.begin(); i != sendQueue.end(); ++i) {
- if (pkt->intersect((*i)->pkt)) {
- pktContinue &= fixPacket(pkt, (*i)->pkt);
- }
+ if (pkt->checkFunctional((*i)->pkt))
+ return;
}
- if (pktContinue) {
- otherPort->sendFunctional(pkt);
- }
+ // fall through if pkt still not satisfied
+ otherPort->sendFunctional(pkt);
}
/** Function called by the port when the bus is receiving a status change.*/
void
Bridge::BridgePort::getDeviceAddressRanges(AddrRangeList &resp,
- AddrRangeList &snoop)
+ bool &snoop)
{
otherPort->getPeerAddressRanges(resp, snoop);
+ // we don't allow snooping across bridges
+ snoop = false;
}
BEGIN_DECLARE_SIM_OBJECT_PARAMS(Bridge)
- Param<int> queue_size_a;
- Param<int> queue_size_b;
+ Param<int> req_size_a;
+ Param<int> req_size_b;
+ Param<int> resp_size_a;
+ Param<int> resp_size_b;
Param<Tick> delay;
+ Param<Tick> nack_delay;
Param<bool> write_ack;
Param<bool> fix_partial_write_a;
Param<bool> fix_partial_write_b;
BEGIN_INIT_SIM_OBJECT_PARAMS(Bridge)
- INIT_PARAM(queue_size_a, "The size of the queue for data coming into side a"),
- INIT_PARAM(queue_size_b, "The size of the queue for data coming into side b"),
+ INIT_PARAM(req_size_a, "The size of the queue for requests coming into side a"),
+ INIT_PARAM(req_size_b, "The size of the queue for requests coming into side b"),
+ INIT_PARAM(resp_size_a, "The size of the queue for responses coming into side a"),
+ INIT_PARAM(resp_size_b, "The size of the queue for responses coming into side b"),
INIT_PARAM(delay, "The miminum delay to cross this bridge"),
+ INIT_PARAM(nack_delay, "The minimum delay to nack a packet"),
INIT_PARAM(write_ack, "Acknowledge any writes that are received."),
INIT_PARAM(fix_partial_write_a, "Fixup any partial block writes that are received"),
INIT_PARAM(fix_partial_write_b, "Fixup any partial block writes that are received")
CREATE_SIM_OBJECT(Bridge)
{
- return new Bridge(getInstanceName(), queue_size_a, queue_size_b, delay,
- write_ack, fix_partial_write_a, fix_partial_write_b);
+ Bridge::Params *p = new Bridge::Params;
+ p->name = getInstanceName();
+ p->req_size_a = req_size_a;
+ p->req_size_b = req_size_b;
+ p->resp_size_a = resp_size_a;
+ p->resp_size_b = resp_size_b;
+ p->delay = delay;
+ p->nack_delay = nack_delay;
+ p->write_ack = write_ack;
+ p->fix_partial_write_a = fix_partial_write_a;
+ p->fix_partial_write_b = fix_partial_write_b;
+ return new Bridge(p);
}
REGISTER_SIM_OBJECT("Bridge", Bridge)
+
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