#include <algorithm>
+#include "base/range_ops.hh"
#include "base/trace.hh"
#include "mem/bridge.hh"
-#include "sim/builder.hh"
+#include "params/Bridge.hh"
Bridge::BridgePort::BridgePort(const std::string &_name,
Bridge *_bridge, BridgePort *_otherPort,
- int _delay, int _queueLimit)
- : Port(_name), bridge(_bridge), otherPort(_otherPort),
- delay(_delay), outstandingResponses(0),
- queueLimit(_queueLimit), sendEvent(this)
+ int _delay, int _nack_delay, int _req_limit,
+ int _resp_limit,
+ std::vector<Range<Addr> > filter_ranges)
+ : Port(_name, _bridge), bridge(_bridge), otherPort(_otherPort),
+ delay(_delay), nackDelay(_nack_delay), filterRanges(filter_ranges),
+ 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)
- : MemObject(n),
- portA(n + "-portA", this, &portB, _delay, qsa),
- portB(n + "-portB", this, &portA, _delay, qsa),
- ackWrites(write_ack)
+Bridge::Bridge(Params *p)
+ : MemObject(p),
+ portA(p->name + "-portA", this, &portB, p->delay, p->nack_delay,
+ p->req_size_a, p->resp_size_a, p->filter_ranges_a),
+ portB(p->name + "-portB", this, &portA, p->delay, p->nack_delay,
+ p->req_size_b, p->resp_size_b, p->filter_ranges_b),
+ ackWrites(p->write_ack), _params(p)
{
+ if (ackWrites)
+ panic("No support for acknowledging writes\n");
}
Port *
else
return NULL;
- if (port->getPeer() != NULL)
- panic("bridge side %s already connected to.", if_name);
+ if (port->getPeer() != NULL && !port->getPeer()->isDefaultPort())
+ panic("bridge side %s already connected to %s.",
+ if_name, port->getPeer()->name());
return port;
}
Bridge::init()
{
// Make sure that both sides are connected to.
- if (portA.getPeer() == NULL || portB.getPeer() == NULL)
- panic("Both ports of bus bridge are not connected to a bus.\n");
+ if (!portA.isConnected() || !portB.isConnected())
+ fatal("Both ports of bus bridge are not connected to a bus.\n");
+
+ if (portA.peerBlockSize() != portB.peerBlockSize())
+ fatal("port A size %d, port B size %d \n " \
+ "Busses don't have the same block size... Not supported.\n",
+ portA.peerBlockSize(), portB.peerBlockSize());
+}
+
+bool
+Bridge::BridgePort::respQueueFull()
+{
+ 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
* transaction.*/
bool
Bridge::BridgePort::recvTiming(PacketPtr pkt)
{
- if (pkt->flags & SNOOP_COMMIT) {
- DPRINTF(BusBridge, "recvTiming: src %d dest %d addr 0x%x\n",
+ DPRINTF(BusBridge, "recvTiming: src %d dest %d addr 0x%x\n",
pkt->getSrc(), pkt->getDest(), pkt->getAddr());
- return otherPort->queueForSendTiming(pkt);
+ DPRINTF(BusBridge, "Local queue size: %d outreq: %d outresp: %d\n",
+ sendQueue.size(), queuedRequests, outstandingResponses);
+ DPRINTF(BusBridge, "Remote queue size: %d outreq: %d outresp: %d\n",
+ otherPort->sendQueue.size(), otherPort->queuedRequests,
+ otherPort->outstandingResponses);
+
+ if (pkt->isRequest() && otherPort->reqQueueFull()) {
+ DPRINTF(BusBridge, "Remote queue full, nacking\n");
+ nackRequest(pkt);
+ return true;
+ }
+
+ 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",
+ sendQueue.size(), queuedRequests, outstandingResponses);
+ nackRequest(pkt);
+ return true;
+ } else {
+ DPRINTF(BusBridge, "Request Needs response, reserving space\n");
+ ++outstandingResponses;
+ }
+ }
+
+ otherPort->queueForSendTiming(pkt);
+
+ return true;
+}
+
+void
+Bridge::BridgePort::nackRequest(PacketPtr pkt)
+{
+ // Nack the packet
+ pkt->makeTimingResponse();
+ pkt->setNacked();
+
+ //put it on the list to send
+ 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());
+ schedule(sendEvent, readyTime);
+ sendQueue.push_back(buf);
+ return;
+ }
+
+ assert(sendEvent.scheduled() || inRetry);
+
+ // does it go at the end?
+ if (readyTime >= sendQueue.back()->ready) {
+ sendQueue.push_back(buf);
+ return;
}
- else {
- // Else it's just a snoop, properly return if we are blocking
- return !queueFull();
+
+ // 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)
+ reschedule(sendEvent, readyTime);
+ sendQueue.insert(i,buf);
+ done = true;
+ }
+ i++;
}
+ assert(done);
}
-bool
+void
Bridge::BridgePort::queueForSendTiming(PacketPtr pkt)
{
- if (queueFull())
- return false;
-
- if (pkt->isResponse()) {
+ 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);
- 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()) {
+ ++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
// should already be an event scheduled for sending the head
// packet.
if (sendQueue.empty()) {
- sendEvent.schedule(readyTime);
+ schedule(sendEvent, readyTime);
}
-
sendQueue.push_back(buf);
-
- return true;
}
void
{
assert(!sendQueue.empty());
- bool was_full = queueFull();
-
PacketBuffer *buf = sendQueue.front();
assert(buf->ready <= curTick);
DPRINTF(BusBridge, "trySend: origSrc %d dest %d addr 0x%x\n",
buf->origSrc, pkt->getDest(), pkt->getAddr());
- pkt->flags &= ~SNOOP_COMMIT; //CLear it if it was set
+ bool wasReq = pkt->isRequest();
+ 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
sendQueue.pop_front();
buf->pkt = NULL; // we no longer own packet, so it's not safe to look at it
if (buf->expectResponse) {
- // Must wait for response. We just need to count outstanding
- // responses (in case we want to cap them); PacketBuffer
- // pointer will be recovered on response.
- ++outstandingResponses;
+ // Must wait for response
DPRINTF(BusBridge, " successful: awaiting response (%d)\n",
outstandingResponses);
} else {
delete buf;
}
+ if (wasReq)
+ --queuedRequests;
+ else if (!was_nacked_here)
+ --outstandingResponses;
+
// If there are more packets to send, schedule event to try again.
if (!sendQueue.empty()) {
buf = sendQueue.front();
- sendEvent.schedule(std::max(buf->ready, curTick + 1));
- }
- // Let things start sending again
- if (was_full) {
- DPRINTF(BusBridge, "Queue was full, sending retry\n");
- otherPort->sendRetry();
+ DPRINTF(BusBridge, "Scheduling next send\n");
+ schedule(sendEvent, std::max(buf->ready, curTick + 1));
}
-
} 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);
}
void
Bridge::BridgePort::recvRetry()
{
- trySend();
+ inRetry = false;
+ Tick nextReady = sendQueue.front()->ready;
+ if (nextReady <= curTick)
+ trySend();
+ else
+ schedule(sendEvent, nextReady);
}
/** Function called by the port when the bus is receiving a Atomic
Tick
Bridge::BridgePort::recvAtomic(PacketPtr pkt)
{
- return otherPort->sendAtomic(pkt) + delay;
+ 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;
+
+ pkt->pushLabel(name());
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);
- }
+ pkt->popLabel();
+
+ // 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);
+ FilterRangeList(filterRanges, resp);
+ // 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<Tick> delay;
- Param<bool> write_ack;
-
-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(delay, "The miminum delay to cross this bridge"),
- INIT_PARAM(write_ack, "Acknowledge any writes that are received.")
-
-END_INIT_SIM_OBJECT_PARAMS(Bridge)
-
-CREATE_SIM_OBJECT(Bridge)
+Bridge *
+BridgeParams::create()
{
- return new Bridge(getInstanceName(), queue_size_a, queue_size_b, delay,
- write_ack);
+ return new Bridge(this);
}
-
-REGISTER_SIM_OBJECT("Bridge", Bridge)
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