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authorAli Saidi <saidi@eecs.umich.edu>2008-08-13 17:41:58 -0400
committerAli Saidi <saidi@eecs.umich.edu>2008-08-13 17:41:58 -0400
commit6248e12704275bf4cc88f1743bb3a4bff7adcf9f (patch)
tree7c85da7cb7e7148f82c474776e7dac89de7c8093 /src/dev
parent549c43b2d0cd2411f7c8eda3f89ce1fd695c17e9 (diff)
downloadgem5-6248e12704275bf4cc88f1743bb3a4bff7adcf9f.tar.xz
Add the ability to specify a think time before descriptor fetch/writeback starts/ends as well as after read/write dmas
Diffstat (limited to 'src/dev')
-rw-r--r--src/dev/Ethernet.py7
-rw-r--r--src/dev/i8254xGBe.cc10
-rw-r--r--src/dev/i8254xGBe.hh75
3 files changed, 71 insertions, 21 deletions
diff --git a/src/dev/Ethernet.py b/src/dev/Ethernet.py
index 2beb0d537..01384b32b 100644
--- a/src/dev/Ethernet.py
+++ b/src/dev/Ethernet.py
@@ -98,6 +98,13 @@ class IGbE(EtherDevice):
InterruptLine = 0x1e
InterruptPin = 0x01
BAR0Size = '128kB'
+ wb_delay = Param.Latency('10ns', "delay before desc writeback occurs")
+ fetch_delay = Param.Latency('10ns', "delay before desc fetch occurs")
+ fetch_comp_delay = Param.Latency('10ns', "delay after desc fetch occurs")
+ wb_comp_delay = Param.Latency('10ns', "delay after desc wb occurs")
+ tx_read_delay = Param.Latency('0ns', "delay after tx dma read")
+ rx_write_delay = Param.Latency('0ns', "delay after rx dma read")
+
class EtherDevBase(EtherDevice):
type = 'EtherDevBase'
diff --git a/src/dev/i8254xGBe.cc b/src/dev/i8254xGBe.cc
index 98040a252..ca60d2e7d 100644
--- a/src/dev/i8254xGBe.cc
+++ b/src/dev/i8254xGBe.cc
@@ -57,7 +57,11 @@ using namespace Net;
IGbE::IGbE(const Params *p)
: EtherDevice(p), etherInt(NULL), drainEvent(NULL), useFlowControl(p->use_flow_control),
rxFifo(p->rx_fifo_size), txFifo(p->tx_fifo_size), rxTick(false),
- txTick(false), txFifoTick(false), rxDmaPacket(false), rdtrEvent(this), radvEvent(this),
+ txTick(false), txFifoTick(false), rxDmaPacket(false),
+ fetchDelay(p->fetch_delay), wbDelay(p->wb_delay),
+ fetchCompDelay(p->fetch_comp_delay), wbCompDelay(p->wb_comp_delay),
+ rxWriteDelay(p->rx_write_delay), txReadDelay(p->tx_read_delay),
+ rdtrEvent(this), radvEvent(this),
tadvEvent(this), tidvEvent(this), tickEvent(this), interEvent(this),
rxDescCache(this, name()+".RxDesc", p->rx_desc_cache_size),
txDescCache(this, name()+".TxDesc", p->tx_desc_cache_size),
@@ -714,7 +718,7 @@ IGbE::RxDescCache::writePacket(EthPacketPtr packet)
pktPtr = packet;
pktDone = false;
igbe->dmaWrite(igbe->platform->pciToDma(unusedCache.front()->buf),
- packet->length, &pktEvent, packet->data);
+ packet->length, &pktEvent, packet->data, igbe->rxWriteDelay);
}
void
@@ -932,7 +936,7 @@ IGbE::TxDescCache::getPacketData(EthPacketPtr p)
DPRINTF(EthernetDesc, "Starting DMA of packet at offset %d\n", p->length);
igbe->dmaRead(igbe->platform->pciToDma(TxdOp::getBuf(desc)),
- TxdOp::getLen(desc), &pktEvent, p->data + p->length);
+ TxdOp::getLen(desc), &pktEvent, p->data + p->length, igbe->txReadDelay);
}
diff --git a/src/dev/i8254xGBe.hh b/src/dev/i8254xGBe.hh
index de73eda79..66a93a509 100644
--- a/src/dev/i8254xGBe.hh
+++ b/src/dev/i8254xGBe.hh
@@ -83,6 +83,11 @@ class IGbE : public EtherDevice
bool rxDmaPacket;
+ // Delays in managaging descriptors
+ Tick fetchDelay, wbDelay;
+ Tick fetchCompDelay, wbCompDelay;
+ Tick rxWriteDelay, txReadDelay;
+
// Event and function to deal with RDTR timer expiring
void rdtrProcess() {
rxDescCache.writeback(0);
@@ -217,7 +222,8 @@ class IGbE : public EtherDevice
public:
DescCache(IGbE *i, const std::string n, int s)
: igbe(i), _name(n), cachePnt(0), size(s), curFetching(0), wbOut(0),
- pktPtr(NULL), fetchEvent(this), wbEvent(this)
+ pktPtr(NULL), wbDelayEvent(this), fetchDelayEvent(this),
+ fetchEvent(this), wbEvent(this)
{
fetchBuf = new T[size];
wbBuf = new T[size];
@@ -244,6 +250,21 @@ class IGbE : public EtherDevice
void writeback(Addr aMask)
{
+ if (wbOut) {
+ if (aMask < wbAlignment) {
+ moreToWb = true;
+ wbAlignment = aMask;
+ }
+ return;
+ }
+
+ wbAlignment = aMask;
+ if (!wbDelayEvent.scheduled())
+ wbDelayEvent.schedule(igbe->wbDelay + curTick);
+ }
+
+ void writeback1()
+ {
int curHead = descHead();
int max_to_wb = usedCache.size();
@@ -252,26 +273,13 @@ class IGbE : public EtherDevice
curHead, descTail(), descLen(), cachePnt, max_to_wb,
descLeft());
- // Check if this writeback is less restrictive that the previous
- // and if so setup another one immediately following it
- if (wbOut && (aMask < wbAlignment)) {
- moreToWb = true;
- wbAlignment = aMask;
- DPRINTF(EthernetDesc, "Writing back already in process, returning\n");
- return;
- }
-
-
- moreToWb = false;
- wbAlignment = aMask;
-
if (max_to_wb + curHead >= descLen()) {
max_to_wb = descLen() - curHead;
moreToWb = true;
// this is by definition aligned correctly
- } else if (aMask != 0) {
+ } else if (wbAlignment != 0) {
// align the wb point to the mask
- max_to_wb = max_to_wb & ~aMask;
+ max_to_wb = max_to_wb & ~wbAlignment;
}
DPRINTF(EthernetDesc, "Writing back %d descriptors\n", max_to_wb);
@@ -291,14 +299,23 @@ class IGbE : public EtherDevice
assert(wbOut);
igbe->dmaWrite(igbe->platform->pciToDma(descBase() + curHead * sizeof(T)),
- wbOut * sizeof(T), &wbEvent, (uint8_t*)wbBuf);
+ wbOut * sizeof(T), &wbEvent, (uint8_t*)wbBuf,
+ igbe->wbCompDelay);
}
+ EventWrapper<DescCache, &DescCache::writeback1> wbDelayEvent;
/** Fetch a chunk of descriptors into the descriptor cache.
* Calls fetchComplete when the memory system returns the data
*/
+
void fetchDescriptors()
{
+ if (!fetchDelayEvent.scheduled())
+ fetchDelayEvent.schedule(igbe->fetchDelay + curTick);
+ }
+
+ void fetchDescriptors1()
+ {
size_t max_to_fetch;
if (curFetching)
@@ -331,9 +348,11 @@ class IGbE : public EtherDevice
curFetching * sizeof(T));
assert(curFetching);
igbe->dmaRead(igbe->platform->pciToDma(descBase() + cachePnt * sizeof(T)),
- curFetching * sizeof(T), &fetchEvent, (uint8_t*)fetchBuf);
+ curFetching * sizeof(T), &fetchEvent, (uint8_t*)fetchBuf,
+ igbe->fetchCompDelay);
}
+ EventWrapper<DescCache, &DescCache::fetchDescriptors1> fetchDelayEvent;
/** Called by event when dma to read descriptors is completed
*/
@@ -391,6 +410,7 @@ class IGbE : public EtherDevice
// If we still have more to wb, call wb now
intAfterWb();
if (moreToWb) {
+ moreToWb = false;
DPRINTF(EthernetDesc, "Writeback has more todo\n");
writeback(wbAlignment);
}
@@ -463,6 +483,16 @@ class IGbE : public EtherDevice
arrayParamOut(os, csprintf("unusedCache_%d", x),
(uint8_t*)unusedCache[x],sizeof(T));
}
+
+ Tick fetch_delay = 0, wb_delay = 0;
+ if (fetchDelayEvent.scheduled())
+ fetch_delay = fetchDelayEvent.when();
+ SERIALIZE_SCALAR(fetch_delay);
+ if (wbDelayEvent.scheduled())
+ wb_delay = wbDelayEvent.when();
+ SERIALIZE_SCALAR(wb_delay);
+
+
}
virtual void unserialize(Checkpoint *cp, const std::string &section)
@@ -491,6 +521,15 @@ class IGbE : public EtherDevice
(uint8_t*)temp,sizeof(T));
unusedCache.push_back(temp);
}
+ Tick fetch_delay = 0, wb_delay = 0;
+ UNSERIALIZE_SCALAR(fetch_delay);
+ UNSERIALIZE_SCALAR(wb_delay);
+ if (fetch_delay)
+ fetchDelayEvent.schedule(fetch_delay);
+ if (wb_delay)
+ wbDelayEvent.schedule(wb_delay);
+
+
}
virtual bool hasOutstandingEvents() {
return wbEvent.scheduled() || fetchEvent.scheduled();