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-rw-r--r--src/mem/bridge.cc118
1 files changed, 84 insertions, 34 deletions
diff --git a/src/mem/bridge.cc b/src/mem/bridge.cc
index e7d52b178..e89473be3 100644
--- a/src/mem/bridge.cc
+++ b/src/mem/bridge.cc
@@ -43,22 +43,22 @@
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");
@@ -94,11 +94,17 @@ Bridge::init()
}
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
@@ -113,14 +119,14 @@ Bridge::BridgePort::recvTiming(PacketPtr pkt)
DPRINTF(BusBridge, "recvTiming: src %d dest %d addr 0x%x\n",
pkt->getSrc(), pkt->getDest(), pkt->getAddr());
- if (pkt->isRequest() && otherPort->queueFull()) {
+ if (pkt->isRequest() && otherPort->reqQueueFull()) {
DPRINTF(BusBridge, "Remote queue full, nacking\n");
nackRequest(pkt);
return true;
}
if (pkt->needsResponse() && pkt->result != Packet::Nacked)
- if (queueFull()) {
+ 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);
@@ -144,12 +150,41 @@ Bridge::BridgePort::nackRequest(PacketPtr pkt)
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);
}
@@ -199,7 +234,6 @@ Bridge::BridgePort::trySend()
{
assert(!sendQueue.empty());
- bool was_full = queueFull();
int pbs = peerBlockSize();
PacketBuffer *buf = sendQueue.front();
@@ -245,15 +279,10 @@ Bridge::BridgePort::trySend()
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);
@@ -263,7 +292,12 @@ Bridge::BridgePort::trySend()
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
@@ -309,9 +343,12 @@ Bridge::BridgePort::getDeviceAddressRanges(AddrRangeList &resp,
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;
@@ -320,9 +357,12 @@ END_DECLARE_SIM_OBJECT_PARAMS(Bridge)
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")
@@ -331,8 +371,18 @@ END_INIT_SIM_OBJECT_PARAMS(Bridge)
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)
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-10 06:32:10 +0000