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authorAli Saidi <saidi@eecs.umich.edu>2007-05-09 18:20:24 -0400
committerAli Saidi <saidi@eecs.umich.edu>2007-05-09 18:20:24 -0400
commit3c608bf76535dc1f08a9563b417b5c6fadeab3ff (patch)
treec262a231f9858a75eeac4f863ab1c288b5100a8d /src/dev
parent37b45e3c8cb2aef57e1d5dd8efd46705b8d46c16 (diff)
downloadgem5-3c608bf76535dc1f08a9563b417b5c6fadeab3ff.tar.xz
add a backoff algorithm when nacks are received by devices
add seperate response buffers and request queue sizes in bus bridge add delay to respond to a nack in the bus bridge src/dev/i8254xGBe.cc: src/dev/ide_ctrl.cc: src/dev/ns_gige.cc: src/dev/pcidev.hh: src/dev/sinic.cc: add backoff delay parameters src/dev/io_device.cc: src/dev/io_device.hh: add a backoff algorithm when nacks are received. src/mem/bridge.cc: src/mem/bridge.hh: add seperate response buffers and request queue sizes add a new parameters to specify how long before a nack in ready to go after a packet that needs to be nacked is received src/mem/cache/cache_impl.hh: assert on the src/mem/tport.cc: add a friendly assert to make sure the packet was inserted into the list --HG-- extra : convert_revision : 3595ad932015a4ce2bb72772da7850ad91bd09b1
Diffstat (limited to 'src/dev')
-rw-r--r--src/dev/i8254xGBe.cc6
-rw-r--r--src/dev/ide_ctrl.cc6
-rw-r--r--src/dev/io_device.cc90
-rw-r--r--src/dev/io_device.hh25
-rw-r--r--src/dev/ns_gige.cc6
-rw-r--r--src/dev/pcidev.hh2
-rw-r--r--src/dev/sinic.cc6
7 files changed, 122 insertions, 19 deletions
diff --git a/src/dev/i8254xGBe.cc b/src/dev/i8254xGBe.cc
index 6acd06132..e54249dee 100644
--- a/src/dev/i8254xGBe.cc
+++ b/src/dev/i8254xGBe.cc
@@ -1460,6 +1460,8 @@ BEGIN_DECLARE_SIM_OBJECT_PARAMS(IGbE)
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;
@@ -1481,6 +1483,8 @@ BEGIN_INIT_SIM_OBJECT_PARAMS(IGbE)
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"),
@@ -1505,6 +1509,8 @@ CREATE_SIM_OBJECT(IGbE)
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;
diff --git a/src/dev/ide_ctrl.cc b/src/dev/ide_ctrl.cc
index 1afad529f..921ba1cd0 100644
--- a/src/dev/ide_ctrl.cc
+++ b/src/dev/ide_ctrl.cc
@@ -751,6 +751,8 @@ BEGIN_DECLARE_SIM_OBJECT_PARAMS(IdeController)
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;
@@ -765,6 +767,8 @@ BEGIN_INIT_SIM_OBJECT_PARAMS(IdeController)
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"),
@@ -781,6 +785,8 @@ CREATE_SIM_OBJECT(IdeController)
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;
diff --git a/src/dev/io_device.cc b/src/dev/io_device.cc
index a1285fefc..9384c4b92 100644
--- a/src/dev/io_device.cc
+++ b/src/dev/io_device.cc
@@ -93,7 +93,8 @@ BasicPioDevice::addressRanges(AddrRangeList &range_list)
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
@@ -104,12 +105,27 @@ DmaPort::recvTiming(PacketPtr pkt)
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--;
@@ -117,6 +133,7 @@ DmaPort::recvTiming(PacketPtr pkt)
assert(state);
state->numBytes += pkt->req->getSize();
+ assert(state->totBytes >= state->numBytes);
if (state->totBytes == state->numBytes) {
state->completionEvent->process();
delete state;
@@ -136,7 +153,8 @@ DmaPort::recvTiming(PacketPtr pkt)
}
DmaDevice::DmaDevice(Params *p)
- : PioDevice(p), dmaPort(NULL)
+ : PioDevice(p), dmaPort(NULL), minBackoffDelay(p->min_backoff_delay),
+ maxBackoffDelay(p->max_backoff_delay)
{ }
@@ -165,19 +183,31 @@ DmaPort::drain(Event *de)
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());
}
@@ -204,33 +234,61 @@ DmaPort::dmaAction(Packet::Command cmd, Addr addr, int size, Event *event,
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);
diff --git a/src/dev/io_device.hh b/src/dev/io_device.hh
index cd7a5296a..bd150bfe4 100644
--- a/src/dev/io_device.hh
+++ b/src/dev/io_device.hh
@@ -107,6 +107,14 @@ class DmaPort : public Port
* 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 }
@@ -122,7 +130,11 @@ class DmaPort : public Port
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);
@@ -249,8 +261,17 @@ class BasicPioDevice : public PioDevice
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);
diff --git a/src/dev/ns_gige.cc b/src/dev/ns_gige.cc
index 86f56b62e..bec1fb848 100644
--- a/src/dev/ns_gige.cc
+++ b/src/dev/ns_gige.cc
@@ -2812,6 +2812,8 @@ BEGIN_DECLARE_SIM_OBJECT_PARAMS(NSGigE)
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;
@@ -2846,6 +2848,8 @@ BEGIN_INIT_SIM_OBJECT_PARAMS(NSGigE)
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"),
@@ -2884,6 +2888,8 @@ CREATE_SIM_OBJECT(NSGigE)
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;
diff --git a/src/dev/pcidev.hh b/src/dev/pcidev.hh
index 56e3ffb4a..5044e2932 100644
--- a/src/dev/pcidev.hh
+++ b/src/dev/pcidev.hh
@@ -105,7 +105,7 @@ class PciDev : public DmaDevice
};
public:
- struct Params : public PioDevice::Params
+ struct Params : public DmaDevice::Params
{
/**
* A pointer to the object that contains the first 64 bytes of
diff --git a/src/dev/sinic.cc b/src/dev/sinic.cc
index f61c161aa..1a72652da 100644
--- a/src/dev/sinic.cc
+++ b/src/dev/sinic.cc
@@ -1635,6 +1635,8 @@ BEGIN_DECLARE_SIM_OBJECT_PARAMS_WNS(Sinic, SinicDevice)
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;
@@ -1678,6 +1680,8 @@ BEGIN_INIT_SIM_OBJECT_PARAMS_WNS(Sinic, SinicDevice)
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"),
@@ -1723,6 +1727,8 @@ CREATE_SIM_OBJECT_WNS(Sinic, SinicDevice)
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;