SimObjectParam<System *> system;
SimObjectParam<Platform *> platform;
+ Param<Tick> min_backoff_delay;
+ Param<Tick> max_backoff_delay;
SimObjectParam<PciConfigData *> configdata;
Param<uint32_t> pci_bus;
Param<uint32_t> pci_dev;
INIT_PARAM(system, "System pointer"),
INIT_PARAM(platform, "Platform pointer"),
+ INIT_PARAM(min_backoff_delay, "Minimum delay after receving a nack packed"),
+ INIT_PARAM(max_backoff_delay, "Maximum delay after receving a nack packed"),
INIT_PARAM(configdata, "PCI Config data"),
INIT_PARAM(pci_bus, "PCI bus ID"),
INIT_PARAM(pci_dev, "PCI device number"),
params->name = getInstanceName();
params->platform = platform;
params->system = system;
+ params->min_backoff_delay = min_backoff_delay;
+ params->max_backoff_delay = max_backoff_delay;
params->configData = configdata;
params->busNum = pci_bus;
params->deviceNum = pci_dev;
SimObjectParam<System *> system;
SimObjectParam<Platform *> platform;
+ Param<Tick> min_backoff_delay;
+ Param<Tick> max_backoff_delay;
SimObjectParam<PciConfigData *> configdata;
Param<uint32_t> pci_bus;
Param<uint32_t> pci_dev;
INIT_PARAM(system, "System pointer"),
INIT_PARAM(platform, "Platform pointer"),
+ INIT_PARAM(min_backoff_delay, "Minimum delay after receving a nack packed"),
+ INIT_PARAM(max_backoff_delay, "Maximum delay after receving a nack packed"),
INIT_PARAM(configdata, "PCI Config data"),
INIT_PARAM(pci_bus, "PCI bus ID"),
INIT_PARAM(pci_dev, "PCI device number"),
params->name = getInstanceName();
params->platform = platform;
params->system = system;
+ params->min_backoff_delay = min_backoff_delay;
+ params->max_backoff_delay = max_backoff_delay;
params->configData = configdata;
params->busNum = pci_bus;
params->deviceNum = pci_dev;
DmaPort::DmaPort(DmaDevice *dev, System *s)
: Port(dev->name() + "-dmaport", dev), device(dev), sys(s),
- pendingCount(0), actionInProgress(0), drainEvent(NULL)
+ pendingCount(0), actionInProgress(0), drainEvent(NULL),
+ backoffTime(0), inRetry(false), backoffEvent(this)
{ }
bool
if (pkt->result == Packet::Nacked) {
DPRINTF(DMA, "Received nacked Pkt %#x with State: %#x Addr: %#x\n",
pkt, pkt->senderState, pkt->getAddr());
+
+ if (backoffTime < device->minBackoffDelay)
+ backoffTime = device->minBackoffDelay;
+ else if (backoffTime < device->maxBackoffDelay)
+ backoffTime <<= 1;
+
+ if (backoffEvent.scheduled())
+ backoffEvent.reschedule(curTick + backoffTime);
+ else
+ backoffEvent.schedule(curTick + backoffTime);
+
+ DPRINTF(DMA, "Backoff time set to %d ticks\n", backoffTime);
+
pkt->reinitNacked();
- sendDma(pkt, true);
+ queueDma(pkt, true);
} else if (pkt->senderState) {
DmaReqState *state;
- DPRINTF(DMA, "Received response Pkt %#x with State: %#x Addr: %#x\n",
- pkt, pkt->senderState, pkt->getAddr());
+ backoffTime >>= 2;
+
+ DPRINTF(DMA, "Received response Pkt %#x with State: %#x Addr: %#x size: %#x\n",
+ pkt, pkt->senderState, pkt->getAddr(), pkt->req->getSize());
state = dynamic_cast<DmaReqState*>(pkt->senderState);
pendingCount--;
assert(state);
state->numBytes += pkt->req->getSize();
+ assert(state->totBytes >= state->numBytes);
if (state->totBytes == state->numBytes) {
state->completionEvent->process();
delete state;
}
DmaDevice::DmaDevice(Params *p)
- : PioDevice(p), dmaPort(NULL)
+ : PioDevice(p), dmaPort(NULL), minBackoffDelay(p->min_backoff_delay),
+ maxBackoffDelay(p->max_backoff_delay)
{ }
void
DmaPort::recvRetry()
{
+ assert(transmitList.size());
PacketPtr pkt = transmitList.front();
bool result = true;
- while (result && transmitList.size()) {
+ do {
DPRINTF(DMA, "Retry on Packet %#x with senderState: %#x\n",
pkt, pkt->senderState);
result = sendTiming(pkt);
if (result) {
DPRINTF(DMA, "-- Done\n");
transmitList.pop_front();
+ inRetry = false;
} else {
+ inRetry = true;
DPRINTF(DMA, "-- Failed, queued\n");
}
+ } while (!backoffTime && result && transmitList.size());
+
+ if (transmitList.size() && backoffTime && !inRetry) {
+ DPRINTF(DMA, "Scheduling backoff for %d\n", curTick+backoffTime);
+ if (!backoffEvent.scheduled())
+ backoffEvent.schedule(backoffTime+curTick);
}
+ DPRINTF(DMA, "TransmitList: %d, backoffTime: %d inRetry: %d es: %d\n",
+ transmitList.size(), backoffTime, inRetry,
+ backoffEvent.scheduled());
}
assert(pendingCount >= 0);
pendingCount++;
- sendDma(pkt);
+ queueDma(pkt);
}
}
+void
+DmaPort::queueDma(PacketPtr pkt, bool front)
+{
+
+ if (front)
+ transmitList.push_front(pkt);
+ else
+ transmitList.push_back(pkt);
+ sendDma();
+}
+
void
-DmaPort::sendDma(PacketPtr pkt, bool front)
+DmaPort::sendDma()
{
// some kind of selction between access methods
// more work is going to have to be done to make
// switching actually work
+ assert(transmitList.size());
+ PacketPtr pkt = transmitList.front();
System::MemoryMode state = sys->getMemoryMode();
if (state == System::Timing) {
+ if (backoffEvent.scheduled() || inRetry) {
+ DPRINTF(DMA, "Can't send immediately, waiting for retry or backoff timer\n");
+ return;
+ }
+
DPRINTF(DMA, "Attempting to send Packet %#x with addr: %#x\n",
pkt, pkt->getAddr());
- if (transmitList.size() || !sendTiming(pkt)) {
- if (front)
- transmitList.push_front(pkt);
- else
- transmitList.push_back(pkt);
- DPRINTF(DMA, "-- Failed: queued\n");
- } else {
- DPRINTF(DMA, "-- Done\n");
+
+ bool result;
+ do {
+ result = sendTiming(pkt);
+ if (result) {
+ transmitList.pop_front();
+ DPRINTF(DMA, "-- Done\n");
+ } else {
+ inRetry = true;
+ DPRINTF(DMA, "-- Failed: queued\n");
+ }
+ } while (result && !backoffTime && transmitList.size());
+
+ if (transmitList.size() && backoffTime && !inRetry &&
+ !backoffEvent.scheduled()) {
+ backoffEvent.schedule(backoffTime+curTick);
}
} else if (state == System::Atomic) {
+ transmitList.pop_front();
+
Tick lat;
lat = sendAtomic(pkt);
assert(pkt->senderState);
* here.*/
Event *drainEvent;
+ /** time to wait between sending another packet, increases as NACKs are
+ * recived, decreases as responses are recived. */
+ Tick backoffTime;
+
+ /** If the port is currently waiting for a retry before it can send whatever
+ * it is that it's sending. */
+ bool inRetry;
+
virtual bool recvTiming(PacketPtr pkt);
virtual Tick recvAtomic(PacketPtr pkt)
{ panic("dma port shouldn't be used for pio access."); M5_DUMMY_RETURN }
AddrRangeList &snoop)
{ resp.clear(); snoop.clear(); }
- void sendDma(PacketPtr pkt, bool front = false);
+ void queueDma(PacketPtr pkt, bool front = false);
+ void sendDma();
+
+ /** event to give us a kick every time we backoff time is reached. */
+ EventWrapper<DmaPort, &DmaPort::sendDma> backoffEvent;
public:
DmaPort(DmaDevice *dev, System *s);
class DmaDevice : public PioDevice
{
- protected:
+ public:
+ struct Params : public PioDevice::Params
+ {
+ Tick min_backoff_delay;
+ Tick max_backoff_delay;
+ };
+
+ protected:
DmaPort *dmaPort;
+ Tick minBackoffDelay;
+ Tick maxBackoffDelay;
public:
DmaDevice(Params *p);
SimObjectParam<System *> system;
SimObjectParam<Platform *> platform;
+ Param<Tick> min_backoff_delay;
+ Param<Tick> max_backoff_delay;
SimObjectParam<PciConfigData *> configdata;
Param<uint32_t> pci_bus;
Param<uint32_t> pci_dev;
INIT_PARAM(system, "System pointer"),
INIT_PARAM(platform, "Platform pointer"),
+ INIT_PARAM(min_backoff_delay, "Minimum delay after receving a nack packed"),
+ INIT_PARAM(max_backoff_delay, "Maximum delay after receving a nack packed"),
INIT_PARAM(configdata, "PCI Config data"),
INIT_PARAM(pci_bus, "PCI bus ID"),
INIT_PARAM(pci_dev, "PCI device number"),
params->name = getInstanceName();
params->platform = platform;
params->system = system;
+ params->min_backoff_delay = min_backoff_delay;
+ params->max_backoff_delay = max_backoff_delay;
params->configData = configdata;
params->busNum = pci_bus;
params->deviceNum = pci_dev;
};
public:
- struct Params : public PioDevice::Params
+ struct Params : public DmaDevice::Params
{
/**
* A pointer to the object that contains the first 64 bytes of
SimObjectParam<System *> system;
SimObjectParam<Platform *> platform;
+ Param<Tick> min_backoff_delay;
+ Param<Tick> max_backoff_delay;
SimObjectParam<PciConfigData *> configdata;
Param<uint32_t> pci_bus;
Param<uint32_t> pci_dev;
INIT_PARAM(system, "System pointer"),
INIT_PARAM(platform, "Platform pointer"),
+ INIT_PARAM(min_backoff_delay, "Minimum delay after receving a nack packed"),
+ INIT_PARAM(max_backoff_delay, "Maximum delay after receving a nack packed"),
INIT_PARAM(configdata, "PCI Config data"),
INIT_PARAM(pci_bus, "PCI bus ID"),
INIT_PARAM(pci_dev, "PCI device number"),
params->name = getInstanceName();
params->platform = platform;
params->system = system;
+ params->min_backoff_delay = min_backoff_delay;
+ params->max_backoff_delay = max_backoff_delay;
params->configData = configdata;
params->busNum = pci_bus;
params->deviceNum = pci_dev;
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
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);
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);
}
{
assert(!sendQueue.empty());
- bool was_full = queueFull();
int pbs = peerBlockSize();
PacketBuffer *buf = sendQueue.front();
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
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)
/** Minimum delay though this bridge. */
Tick delay;
+ /** Min delay to respond to a nack. */
+ Tick nackDelay;
+
bool fixPartialWrite;
class PacketBuffer : public Packet::SenderState {
int outstandingResponses;
int queuedRequests;
+ /** If we're waiting for a retry to happen.*/
+ bool inRetry;
+
/** Max queue size for outbound packets */
- int queueLimit;
+ int reqQueueLimit;
+
+ /** Max queue size for reserved responses. */
+ int respQueueLimit;
/**
* Is this side blocked from accepting outbound packets?
*/
- bool queueFull();
+ bool respQueueFull();
+ bool reqQueueFull();
void queueForSendTiming(PacketPtr pkt);
SendEvent sendEvent;
public:
-
/** Constructor for the BusPort.*/
- BridgePort(const std::string &_name,
- Bridge *_bridge, BridgePort *_otherPort,
- int _delay, int _queueLimit, bool fix_partial_write);
+ BridgePort(const std::string &_name, Bridge *_bridge,
+ BridgePort *_otherPort, int _delay, int _nack_delay,
+ int _req_limit, int _resp_limit, bool fix_partial_write);
protected:
bool ackWrites;
public:
+ struct Params
+ {
+ std::string name;
+ int req_size_a;
+ int req_size_b;
+ int resp_size_a;
+ int resp_size_b;
+ Tick delay;
+ Tick nack_delay;
+ bool write_ack;
+ bool fix_partial_write_a;
+ bool fix_partial_write_b;
+ };
+
+ protected:
+ Params *_params;
+
+ public:
+ const Params *params() const { return _params; }
/** A function used to return the port associated with this bus object. */
virtual Port *getPort(const std::string &if_name, int idx = -1);
virtual void init();
- Bridge(const std::string &n, int qsa, int qsb, Tick _delay, int write_ack,
- bool fix_partial_write_a, bool fix_partial_write_b);
+ Bridge(Params *p);
};
#endif //__MEM_BUS_HH__
bool
Cache<TagStore,Coherence>::CpuSidePort::recvTiming(PacketPtr pkt)
{
+ assert(pkt->result != Packet::Nacked);
+
if (!pkt->req->isUncacheable()
&& pkt->isInvalidate()
&& !pkt->isRead() && !pkt->isWrite()) {
bool
Cache<TagStore,Coherence>::MemSidePort::recvTiming(PacketPtr pkt)
{
+ // this needs to be fixed so that the cache updates the mshr and sends the
+ // packet back out on the link, but it probably won't happen so until this
+ // gets fixed, just panic when it does
+ if (pkt->result == Packet::Nacked)
+ panic("Need to implement cache resending nacked packets!\n");
+
if (pkt->isRequest() && blocked)
{
DPRINTF(Cache,"Scheduling a retry while blocked\n");
}
i++;
}
+ assert(done);
}
void
projects / gem5.git / commitdiff