sanchayanmaity/gem5
1
0
Fork 0
Code Issues Pull requests Packages Projects Releases Wiki Activity

Potentially functional partially timed bandwidth limitted bus model.

Browse source 
src/mem/bus.cc:
    Fixes to the previous hand merging, and put the snooping back into recvTiming and out of it's own function.
src/mem/bus.hh:
    Put snooping back into recvTiming and not in it's own function.

--HG--
extra : convert_revision : fd031b7e6051a5be07ed6926454fde73b1739dc6
This commit is contained in:
Gabe Black 2006-10-09 18:12:45 -04:00
parent 2df9053bb0
commit 187dcb18bf
2 changed files with 33 additions and 37 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

61
src/mem/bus.cc
View file

@ -118,25 +118,26 @@ Bus::recvTiming(Packet *pkt)
DPRINTF(Bus, "recvTiming: packet src %d dest %d addr 0x%x cmd %s\n",
pkt->getSrc(), pkt->getDest(), pkt->getAddr(), pkt->cmdString());
Port *pktPort = interfaces[pkt->getSrc()];
short dest = pkt->getDest();
if (dest == Packet::Broadcast) {
if ( timingSnoopPhase1(pkt) )
if (timingSnoop(pkt))
{
timingSnoopPhase2(pkt);
if (timingSnoop(pkt)) {
pkt->flags |= SNOOP_COMMIT;
bool success = timingSnoop(pkt);
assert(success);
if (pkt->flags & SATISFIED) {
//Cache-Cache transfer occuring
if (retryingPort) {
retryList.pop_front();
retryingPort = NULL;
}
return true;
}
port = findPort(pkt->getAddr(), pkt->getSrc());
}
else
{
} else {
//Snoop didn't succeed
retryList.push_back(interfaces[pkt->getSrc()]);
addToRetryList(pktPort);
return false;
}
} else {
@ -144,6 +145,30 @@ Bus::recvTiming(Packet *pkt)
assert(dest != pkt->getSrc()); // catch infinite loops
port = interfaces[dest];
}
// The packet will be sent. Figure out how long it occupies the bus.
int numCycles = 0;
// Requests need one cycle to send an address
if (pkt->isRequest())
numCycles++;
else if (pkt->isResponse() || pkt->hasData()) {
// If a packet has data, it needs ceil(size/width) cycles to send it
// We're using the "adding instead of dividing" trick again here
if (pkt->hasData()) {
int dataSize = pkt->getSize();
for (int transmitted = 0; transmitted < dataSize;
transmitted += width) {
numCycles++;
}
} else {
// If the packet didn't have data, it must have been a response.
// Those use the bus for one cycle to send their data.
numCycles++;
}
}
occupyBus(numCycles);
if (port->sendTiming(pkt)) {
// Packet was successfully sent. Return true.
// Also take care of retries
@ -175,26 +200,6 @@ Bus::recvRetry(int id)
}
}
Port *
Bus::findDestPort(PacketPtr pkt, int id)
{
Port * port = NULL;
short dest = pkt->getDest();
if (dest == Packet::Broadcast) {
if (timingSnoopPhase1(pkt)) {
timingSnoopPhase2(pkt);
port = findPort(pkt->getAddr(), pkt->getSrc());
}
//else, port stays NULL
} else {
assert(dest >= 0 && dest < interfaces.size());
assert(dest != pkt->getSrc()); // catch infinite loops
port = interfaces[dest];
}
return port;
}
Port *
Bus::findPort(Addr addr, int id)
{

9
src/mem/bus.hh
View file

@ -97,15 +97,6 @@ class Bus : public MemObject
*/
Port *findPort(Addr addr, int id);
/** Finds the port a packet should be sent to. If the bus is blocked, no port
* is returned.
* @param pkt Packet to find a destination port for.
* @param id Id of the port this packet was received from
* (to prevent loops)
*/
Port *findDestPort(PacketPtr pkt, int id);
/** Find all ports with a matching snoop range, except src port. Keep in mind
* that the ranges shouldn't overlap or you will get a double snoop to the same
* interface.and the cache will assert out.