/*
- * Copyright (c) 2011-2012 ARM Limited
+ * Copyright (c) 2011-2013 ARM Limited
* All rights reserved
*
* The license below extends only to copyright in the software and shall
#include "base/trace.hh"
#include "debug/Bus.hh"
#include "debug/BusAddrRanges.hh"
+#include "debug/Drain.hh"
#include "mem/bus.hh"
-Bus::Bus(const BusParams *p)
- : MemObject(p), clock(p->clock),
- headerCycles(p->header_cycles), width(p->width), tickNextIdle(0),
- drainEvent(NULL), busIdleEvent(this), inRetry(false),
- defaultPortId(Port::INVALID_PORT_ID),
+BaseBus::BaseBus(const BaseBusParams *p)
+ : MemObject(p),
+ headerCycles(p->header_cycles), width(p->width),
+ gotAddrRanges(p->port_default_connection_count +
+ p->port_master_connection_count, false),
+ gotAllAddrRanges(false), defaultPortID(InvalidPortID),
useDefaultRange(p->use_default_range),
- defaultBlockSize(p->block_size),
- cachedBlockSize(0), cachedBlockSizeValid(false)
+ blockSize(p->block_size)
+{}
+
+BaseBus::~BaseBus()
{
- //width, clock period, and header cycles must be positive
- if (width <= 0)
- fatal("Bus width must be positive\n");
- if (clock <= 0)
- fatal("Bus clock period must be positive\n");
- if (headerCycles <= 0)
- fatal("Number of header cycles must be positive\n");
-
- // create the ports based on the size of the master and slave
- // vector ports, and the presence of the default port, the ports
- // are enumerated starting from zero
- for (int i = 0; i < p->port_master_connection_count; ++i) {
- std::string portName = csprintf("%s-p%d", name(), i);
- MasterPort* bp = new BusMasterPort(portName, this, i);
- masterPorts.push_back(bp);
+ for (MasterPortIter m = masterPorts.begin(); m != masterPorts.end();
+ ++m) {
+ delete *m;
}
- // see if we have a default slave device connected and if so add
- // our corresponding master port
- if (p->port_default_connection_count) {
- defaultPortId = masterPorts.size();
- std::string portName = csprintf("%s-default", name());
- MasterPort* bp = new BusMasterPort(portName, this, defaultPortId);
- masterPorts.push_back(bp);
+ for (SlavePortIter s = slavePorts.begin(); s != slavePorts.end();
+ ++s) {
+ delete *s;
}
+}
+
+void
+BaseBus::init()
+{
+ // determine the maximum peer block size, look at both the
+ // connected master and slave modules
+ uint32_t peer_block_size = 0;
- // create the slave ports, once again starting at zero
- for (int i = 0; i < p->port_slave_connection_count; ++i) {
- std::string portName = csprintf("%s-p%d", name(), i);
- SlavePort* bp = new BusSlavePort(portName, this, i);
- slavePorts.push_back(bp);
+ for (MasterPortConstIter m = masterPorts.begin(); m != masterPorts.end();
+ ++m) {
+ peer_block_size = std::max((*m)->peerBlockSize(), peer_block_size);
}
- clearPortCache();
+ for (SlavePortConstIter s = slavePorts.begin(); s != slavePorts.end();
+ ++s) {
+ peer_block_size = std::max((*s)->peerBlockSize(), peer_block_size);
+ }
+
+ // if the peers do not have a block size, use the default value
+ // set through the bus parameters
+ if (peer_block_size != 0)
+ blockSize = peer_block_size;
+
+ // check if the block size is a value known to work
+ if (!(blockSize == 16 || blockSize == 32 || blockSize == 64 ||
+ blockSize == 128))
+ warn_once("Block size is neither 16, 32, 64 or 128 bytes.\n");
}
-MasterPort &
-Bus::getMasterPort(const std::string &if_name, int idx)
+BaseMasterPort &
+BaseBus::getMasterPort(const std::string &if_name, PortID idx)
{
if (if_name == "master" && idx < masterPorts.size()) {
// the master port index translates directly to the vector position
return *masterPorts[idx];
} else if (if_name == "default") {
- return *masterPorts[defaultPortId];
+ return *masterPorts[defaultPortID];
} else {
return MemObject::getMasterPort(if_name, idx);
}
}
-SlavePort &
-Bus::getSlavePort(const std::string &if_name, int idx)
+BaseSlavePort &
+BaseBus::getSlavePort(const std::string &if_name, PortID idx)
{
if (if_name == "slave" && idx < slavePorts.size()) {
// the slave port index translates directly to the vector position
}
void
-Bus::init()
+BaseBus::calcPacketTiming(PacketPtr pkt)
{
- // iterate over our slave ports and determine which of our
- // neighbouring master ports are snooping and add them as snoopers
- for (SlavePortConstIter p = slavePorts.begin(); p != slavePorts.end();
- ++p) {
- if ((*p)->getMasterPort().isSnooping()) {
- DPRINTF(BusAddrRanges, "Adding snooping neighbour %s\n",
- (*p)->getMasterPort().name());
- snoopPorts.push_back(*p);
- }
- }
-}
-
-Tick
-Bus::calcPacketTiming(PacketPtr pkt)
-{
- // determine the current time rounded to the closest following
- // clock edge
- Tick now = curTick();
- if (now % clock != 0) {
- now = ((now / clock) + 1) * clock;
- }
-
- Tick headerTime = now + headerCycles * clock;
-
- // The packet will be sent. Figure out how long it occupies the bus, and
- // how much of that time is for the first "word", aka bus width.
- int numCycles = 0;
- if (pkt->hasData()) {
- // If a packet has data, it needs ceil(size/width) cycles to send it
- int dataSize = pkt->getSize();
- numCycles += dataSize/width;
- if (dataSize % width)
- numCycles++;
- }
-
- // The first word will be delivered after the current tick, the delivery
- // of the address if any, and one bus cycle to deliver the data
- pkt->firstWordTime = headerTime + clock;
-
- pkt->finishTime = headerTime + numCycles * clock;
-
- return headerTime;
+ // the bus will be called at a time that is not necessarily
+ // coinciding with its own clock, so start by determining how long
+ // until the next clock edge (could be zero)
+ Tick offset = nextCycle() - curTick();
+
+ // determine how many cycles are needed to send the data
+ unsigned dataCycles = pkt->hasData() ? divCeil(pkt->getSize(), width) : 0;
+
+ // before setting the bus delay fields of the packet, ensure that
+ // the delay from any previous bus has been accounted for
+ if (pkt->busFirstWordDelay != 0 || pkt->busLastWordDelay != 0)
+ panic("Packet %s already has bus delay (%d, %d) that should be "
+ "accounted for.\n", pkt->cmdString(), pkt->busFirstWordDelay,
+ pkt->busLastWordDelay);
+
+ // The first word will be delivered on the cycle after the header.
+ pkt->busFirstWordDelay = (headerCycles + 1) * clockPeriod() + offset;
+
+ // Note that currently busLastWordDelay can be smaller than
+ // busFirstWordDelay if the packet has no data
+ pkt->busLastWordDelay = (headerCycles + dataCycles) * clockPeriod() +
+ offset;
}
-void Bus::occupyBus(Tick until)
+template <typename PortClass>
+BaseBus::Layer<PortClass>::Layer(BaseBus& _bus, const std::string& _name) :
+ Drainable(),
+ bus(_bus), _name(_name), state(IDLE), drainManager(NULL),
+ releaseEvent(this)
{
- if (until == 0) {
- // shortcut for express snoop packets
- return;
- }
-
- tickNextIdle = until;
- reschedule(busIdleEvent, tickNextIdle, true);
-
- DPRINTF(Bus, "The bus is now occupied from tick %d to %d\n",
- curTick(), tickNextIdle);
}
-bool
-Bus::isOccupied(PacketPtr pkt, Port* port)
+template <typename PortClass>
+void BaseBus::Layer<PortClass>::occupyLayer(Tick until)
{
- // first we see if the next idle tick is in the future, next the
- // bus is considered occupied if there are ports on the retry list
- // and we are not in a retry with the current port
- if (tickNextIdle > curTick() ||
- (!retryList.empty() && !(inRetry && port == retryList.front()))) {
- addToRetryList(port);
- return true;
- }
- return false;
+ // ensure the state is busy or in retry and never idle at this
+ // point, as the bus should transition from idle as soon as it has
+ // decided to forward the packet to prevent any follow-on calls to
+ // sendTiming seeing an unoccupied bus
+ assert(state != IDLE);
+
+ // note that we do not change the bus state here, if we are going
+ // from idle to busy it is handled by tryTiming, and if we
+ // are in retry we should remain in retry such that
+ // succeededTiming still sees the accurate state
+
+ // until should never be 0 as express snoops never occupy the bus
+ assert(until != 0);
+ bus.schedule(releaseEvent, until);
+
+ DPRINTF(BaseBus, "The bus is now busy from tick %d to %d\n",
+ curTick(), until);
}
+template <typename PortClass>
bool
-Bus::recvTimingReq(PacketPtr pkt)
+BaseBus::Layer<PortClass>::tryTiming(PortClass* port)
{
- // determine the source port based on the id
- SlavePort *src_port = slavePorts[pkt->getSrc()];
-
- // test if the bus should be considered occupied for the current
- // packet, and exclude express snoops from the check
- if (!pkt->isExpressSnoop() && isOccupied(pkt, src_port)) {
- DPRINTF(Bus, "recvTimingReq: src %s %s 0x%x BUSY\n",
- src_port->name(), pkt->cmdString(), pkt->getAddr());
- return false;
- }
-
- DPRINTF(Bus, "recvTimingReq: src %s %s 0x%x\n",
- src_port->name(), pkt->cmdString(), pkt->getAddr());
-
- Tick headerFinishTime = pkt->isExpressSnoop() ? 0 : calcPacketTiming(pkt);
- Tick packetFinishTime = pkt->isExpressSnoop() ? 0 : pkt->finishTime;
-
- // the packet is a memory-mapped request and should be
- // broadcasted to our snoopers but the source
- forwardTiming(pkt, pkt->getSrc());
-
- // remember if we add an outstanding req so we can undo it if
- // necessary, if the packet needs a response, we should add it
- // as outstanding and express snoops never fail so there is
- // not need to worry about them
- bool add_outstanding = !pkt->isExpressSnoop() && pkt->needsResponse();
-
- // keep track that we have an outstanding request packet
- // matching this request, this is used by the coherency
- // mechanism in determining what to do with snoop responses
- // (in recvTimingSnoop)
- if (add_outstanding) {
- // we should never have an exsiting request outstanding
- assert(outstandingReq.find(pkt->req) == outstandingReq.end());
- outstandingReq.insert(pkt->req);
- }
-
- // since it is a normal request, determine the destination
- // based on the address and attempt to send the packet
- bool success = masterPorts[findPort(pkt->getAddr())]->sendTimingReq(pkt);
-
- if (!success) {
- // inhibited packets should never be forced to retry
- assert(!pkt->memInhibitAsserted());
-
- // if it was added as outstanding and the send failed, then
- // erase it again
- if (add_outstanding)
- outstandingReq.erase(pkt->req);
-
- DPRINTF(Bus, "recvTimingReq: src %s %s 0x%x RETRY\n",
- src_port->name(), pkt->cmdString(), pkt->getAddr());
-
- addToRetryList(src_port);
- occupyBus(headerFinishTime);
-
+ // first we see if the bus is busy, next we check if we are in a
+ // retry with a port other than the current one
+ if (state == BUSY || (state == RETRY && port != retryList.front())) {
+ // put the port at the end of the retry list
+ retryList.push_back(port);
return false;
}
- succeededTiming(packetFinishTime);
+ // update the state which is shared for request, response and
+ // snoop responses, if we were idle we are now busy, if we are in
+ // a retry, then do not change
+ if (state == IDLE)
+ state = BUSY;
return true;
}
-bool
-Bus::recvTimingResp(PacketPtr pkt)
+template <typename PortClass>
+void
+BaseBus::Layer<PortClass>::succeededTiming(Tick busy_time)
{
- // determine the source port based on the id
- MasterPort *src_port = masterPorts[pkt->getSrc()];
-
- // test if the bus should be considered occupied for the current
- // packet
- if (isOccupied(pkt, src_port)) {
- DPRINTF(Bus, "recvTimingResp: src %s %s 0x%x BUSY\n",
- src_port->name(), pkt->cmdString(), pkt->getAddr());
- return false;
+ // if a retrying port succeeded, also take it off the retry list
+ if (state == RETRY) {
+ DPRINTF(BaseBus, "Remove retry from list %s\n",
+ retryList.front()->name());
+ retryList.pop_front();
+ state = BUSY;
}
- DPRINTF(Bus, "recvTimingResp: src %s %s 0x%x\n",
- src_port->name(), pkt->cmdString(), pkt->getAddr());
+ // we should either have gone from idle to busy in the
+ // tryTiming test, or just gone from a retry to busy
+ assert(state == BUSY);
- calcPacketTiming(pkt);
- Tick packetFinishTime = pkt->finishTime;
-
- // the packet is a normal response to a request that we should
- // have seen passing through the bus
- assert(outstandingReq.find(pkt->req) != outstandingReq.end());
-
- // remove it as outstanding
- outstandingReq.erase(pkt->req);
-
- // send the packet to the destination through one of our slave
- // ports, as determined by the destination field
- bool success M5_VAR_USED = slavePorts[pkt->getDest()]->sendTimingResp(pkt);
-
- // currently it is illegal to block responses... can lead to
- // deadlock
- assert(success);
-
- succeededTiming(packetFinishTime);
-
- return true;
+ // occupy the bus accordingly
+ occupyLayer(busy_time);
}
+template <typename PortClass>
void
-Bus::recvTimingSnoopReq(PacketPtr pkt)
-{
- DPRINTF(Bus, "recvTimingSnoopReq: src %s %s 0x%x\n",
- masterPorts[pkt->getSrc()]->name(), pkt->cmdString(),
- pkt->getAddr());
-
- // we should only see express snoops from caches
- assert(pkt->isExpressSnoop());
-
- // forward to all snoopers
- forwardTiming(pkt, Port::INVALID_PORT_ID);
-
- // a snoop request came from a connected slave device (one of
- // our master ports), and if it is not coming from the slave
- // device responsible for the address range something is
- // wrong, hence there is nothing further to do as the packet
- // would be going back to where it came from
- assert(pkt->getSrc() == findPort(pkt->getAddr()));
-
- // this is an express snoop and is never forced to retry
- assert(!inRetry);
-}
-
-bool
-Bus::recvTimingSnoopResp(PacketPtr pkt)
+BaseBus::Layer<PortClass>::failedTiming(PortClass* port, Tick busy_time)
{
- // determine the source port based on the id
- SlavePort* src_port = slavePorts[pkt->getSrc()];
-
- if (isOccupied(pkt, src_port)) {
- DPRINTF(Bus, "recvTimingSnoopResp: src %s %s 0x%x BUSY\n",
- src_port->name(), pkt->cmdString(), pkt->getAddr());
- return false;
+ // if we are not in a retry, i.e. busy (but never idle), or we are
+ // in a retry but not for the current port, then add the port at
+ // the end of the retry list
+ if (state != RETRY || port != retryList.front()) {
+ retryList.push_back(port);
}
- DPRINTF(Bus, "recvTimingSnoop: src %s %s 0x%x\n",
- src_port->name(), pkt->cmdString(), pkt->getAddr());
-
- // get the destination from the packet
- Packet::NodeID dest = pkt->getDest();
-
- // responses are never express snoops
- assert(!pkt->isExpressSnoop());
+ // even if we retried the current one and did not succeed,
+ // we are no longer retrying but instead busy
+ state = BUSY;
- calcPacketTiming(pkt);
- Tick packetFinishTime = pkt->finishTime;
-
- // determine if the response is from a snoop request we
- // created as the result of a normal request (in which case it
- // should be in the outstandingReq), or if we merely forwarded
- // someone else's snoop request
- if (outstandingReq.find(pkt->req) == outstandingReq.end()) {
- // this is a snoop response to a snoop request we
- // forwarded, e.g. coming from the L1 and going to the L2
- // this should be forwarded as a snoop response
- bool success M5_VAR_USED = masterPorts[dest]->sendTimingSnoopResp(pkt);
- assert(success);
- } else {
- // we got a snoop response on one of our slave ports,
- // i.e. from a coherent master connected to the bus, and
- // since we created the snoop request as part of
- // recvTiming, this should now be a normal response again
- outstandingReq.erase(pkt->req);
-
- // this is a snoop response from a coherent master, with a
- // destination field set on its way through the bus as
- // request, hence it should never go back to where the
- // snoop response came from, but instead to where the
- // original request came from
- assert(pkt->getSrc() != dest);
-
- // as a normal response, it should go back to a master
- // through one of our slave ports
- bool success M5_VAR_USED = slavePorts[dest]->sendTimingResp(pkt);
-
- // currently it is illegal to block responses... can lead
- // to deadlock
- assert(success);
- }
-
- succeededTiming(packetFinishTime);
-
- return true;
-}
-
-
-void
-Bus::succeededTiming(Tick busy_time)
-{
// occupy the bus accordingly
- occupyBus(busy_time);
-
- // if a retrying port succeeded, also take it off the retry list
- if (inRetry) {
- DPRINTF(Bus, "Remove retry from list %s\n",
- retryList.front()->name());
- retryList.pop_front();
- inRetry = false;
- }
-}
-
-void
-Bus::forwardTiming(PacketPtr pkt, int exclude_slave_port_id)
-{
- for (SlavePortIter s = snoopPorts.begin(); s != snoopPorts.end(); ++s) {
- SlavePort *p = *s;
- // we could have gotten this request from a snooping master
- // (corresponding to our own slave port that is also in
- // snoopPorts) and should not send it back to where it came
- // from
- if (exclude_slave_port_id == Port::INVALID_PORT_ID ||
- p->getId() != exclude_slave_port_id) {
- // cache is not allowed to refuse snoop
- p->sendTimingSnoopReq(pkt);
- }
- }
+ occupyLayer(busy_time);
}
+template <typename PortClass>
void
-Bus::releaseBus()
+BaseBus::Layer<PortClass>::releaseLayer()
{
// releasing the bus means we should now be idle
- assert(curTick() >= tickNextIdle);
+ assert(state == BUSY);
+ assert(!releaseEvent.scheduled());
+
+ // update the state
+ state = IDLE;
// bus is now idle, so if someone is waiting we can retry
if (!retryList.empty()) {
// busy, and in the latter case the bus may be released before
// we see a retry from the destination
retryWaiting();
- }
-
- //If we weren't able to drain before, we might be able to now.
- if (drainEvent && retryList.empty() && curTick() >= tickNextIdle) {
- drainEvent->process();
+ } else if (drainManager) {
+ DPRINTF(Drain, "Bus done draining, signaling drain manager\n");
+ //If we weren't able to drain before, do it now.
+ drainManager->signalDrainDone();
// Clear the drain event once we're done with it.
- drainEvent = NULL;
+ drainManager = NULL;
}
}
+template <typename PortClass>
void
-Bus::retryWaiting()
+BaseBus::Layer<PortClass>::retryWaiting()
{
// this should never be called with an empty retry list
assert(!retryList.empty());
- // send a retry to the port at the head of the retry list
- inRetry = true;
+ // we always go to retrying from idle
+ assert(state == IDLE);
+
+ // update the state which is shared for request, response and
+ // snoop responses
+ state = RETRY;
// note that we might have blocked on the receiving port being
// busy (rather than the bus itself) and now call retry before the
// destination called retry on the bus
retryList.front()->sendRetry();
- // If inRetry is still true, sendTiming wasn't called in zero time
- // (e.g. the cache does this)
- if (inRetry) {
+ // If the bus is still in the retry state, sendTiming wasn't
+ // called in zero time (e.g. the cache does this)
+ if (state == RETRY) {
retryList.pop_front();
- inRetry = false;
-
- //Bring tickNextIdle up to the present
- while (tickNextIdle < curTick())
- tickNextIdle += clock;
//Burn a cycle for the missed grant.
- tickNextIdle += clock;
- reschedule(busIdleEvent, tickNextIdle, true);
+ // update the state which is shared for request, response and
+ // snoop responses
+ state = BUSY;
+
+ // occupy the bus layer until the next cycle ends
+ occupyLayer(bus.clockEdge(Cycles(1)));
}
}
+template <typename PortClass>
void
-Bus::recvRetry(Port::PortId id)
+BaseBus::Layer<PortClass>::recvRetry()
{
// we got a retry from a peer that we tried to send something to
// and failed, but we sent it on the account of someone else, and
// that source port should be on our retry list, however if the
- // bus is released before this happens and the retry (from the bus
- // point of view) is successful then this no longer holds and we
- // could in fact have an empty retry list
+ // bus layer is released before this happens and the retry (from
+ // the bus point of view) is successful then this no longer holds
+ // and we could in fact have an empty retry list
if (retryList.empty())
return;
- // if the bus isn't busy
- if (curTick() >= tickNextIdle) {
+ // if the bus layer is idle
+ if (state == IDLE) {
// note that we do not care who told us to retry at the moment, we
// merely let the first one on the retry list go
retryWaiting();
}
}
-int
-Bus::findPort(Addr addr)
+PortID
+BaseBus::findPort(Addr addr)
{
- /* An interval tree would be a better way to do this. --ali. */
- int dest_id;
+ // we should never see any address lookups before we've got the
+ // ranges of all connected slave modules
+ assert(gotAllAddrRanges);
- dest_id = checkPortCache(addr);
- if (dest_id != Port::INVALID_PORT_ID)
+ // Check the cache
+ PortID dest_id = checkPortCache(addr);
+ if (dest_id != InvalidPortID)
return dest_id;
- // Check normal port ranges
- PortIter i = portMap.find(RangeSize(addr,1));
+ // Check the address map interval tree
+ PortMapConstIter i = portMap.find(addr);
if (i != portMap.end()) {
dest_id = i->second;
- updatePortCache(dest_id, i->first.start, i->first.end);
+ updatePortCache(dest_id, i->first);
return dest_id;
}
// Check if this matches the default range
if (useDefaultRange) {
- AddrRangeIter a_end = defaultRange.end();
- for (AddrRangeIter i = defaultRange.begin(); i != a_end; i++) {
- if (*i == addr) {
- DPRINTF(Bus, " found addr %#llx on default\n", addr);
- return defaultPortId;
- }
+ if (defaultRange.contains(addr)) {
+ DPRINTF(BusAddrRanges, " found addr %#llx on default\n",
+ addr);
+ return defaultPortID;
}
- } else if (defaultPortId != Port::INVALID_PORT_ID) {
- DPRINTF(Bus, "Unable to find destination for addr %#llx, "
+ } else if (defaultPortID != InvalidPortID) {
+ DPRINTF(BusAddrRanges, "Unable to find destination for addr %#llx, "
"will use default port\n", addr);
- return defaultPortId;
+ return defaultPortID;
}
// we should use the range for the default port and it did not
name());
}
-Tick
-Bus::recvAtomic(PacketPtr pkt)
-{
- DPRINTF(Bus, "recvAtomic: packet src %s addr 0x%x cmd %s\n",
- slavePorts[pkt->getSrc()]->name(), pkt->getAddr(),
- pkt->cmdString());
-
- // forward to all snoopers but the source
- std::pair<MemCmd, Tick> snoop_result = forwardAtomic(pkt, pkt->getSrc());
- MemCmd snoop_response_cmd = snoop_result.first;
- Tick snoop_response_latency = snoop_result.second;
-
- // even if we had a snoop response, we must continue and also
- // perform the actual request at the destination
- int dest_id = findPort(pkt->getAddr());
-
- // forward the request to the appropriate destination
- Tick response_latency = masterPorts[dest_id]->sendAtomic(pkt);
-
- // if we got a response from a snooper, restore it here
- if (snoop_response_cmd != MemCmd::InvalidCmd) {
- // no one else should have responded
- assert(!pkt->isResponse());
- pkt->cmd = snoop_response_cmd;
- response_latency = snoop_response_latency;
- }
-
- pkt->finishTime = curTick() + response_latency;
- return response_latency;
-}
-
-Tick
-Bus::recvAtomicSnoop(PacketPtr pkt)
+/** Function called by the port when the bus is receiving a range change.*/
+void
+BaseBus::recvRangeChange(PortID master_port_id)
{
- DPRINTF(Bus, "recvAtomicSnoop: packet src %s addr 0x%x cmd %s\n",
- masterPorts[pkt->getSrc()]->name(), pkt->getAddr(),
- pkt->cmdString());
-
- // forward to all snoopers
- std::pair<MemCmd, Tick> snoop_result =
- forwardAtomic(pkt, Port::INVALID_PORT_ID);
- MemCmd snoop_response_cmd = snoop_result.first;
- Tick snoop_response_latency = snoop_result.second;
+ DPRINTF(BusAddrRanges, "Received range change from slave port %s\n",
+ masterPorts[master_port_id]->getSlavePort().name());
+
+ // remember that we got a range from this master port and thus the
+ // connected slave module
+ gotAddrRanges[master_port_id] = true;
+
+ // update the global flag
+ if (!gotAllAddrRanges) {
+ // take a logical AND of all the ports and see if we got
+ // ranges from everyone
+ gotAllAddrRanges = true;
+ std::vector<bool>::const_iterator r = gotAddrRanges.begin();
+ while (gotAllAddrRanges && r != gotAddrRanges.end()) {
+ gotAllAddrRanges &= *r++;
+ }
+ if (gotAllAddrRanges)
+ DPRINTF(BusAddrRanges, "Got address ranges from all slaves\n");
+ }
+
+ // note that we could get the range from the default port at any
+ // point in time, and we cannot assume that the default range is
+ // set before the other ones are, so we do additional checks once
+ // all ranges are provided
+ if (master_port_id == defaultPortID) {
+ // only update if we are indeed checking ranges for the
+ // default port since the port might not have a valid range
+ // otherwise
+ if (useDefaultRange) {
+ AddrRangeList ranges = masterPorts[master_port_id]->getAddrRanges();
- if (snoop_response_cmd != MemCmd::InvalidCmd)
- pkt->cmd = snoop_response_cmd;
+ if (ranges.size() != 1)
+ fatal("Bus %s may only have a single default range",
+ name());
- pkt->finishTime = curTick() + snoop_response_latency;
- return snoop_response_latency;
-}
-
-std::pair<MemCmd, Tick>
-Bus::forwardAtomic(PacketPtr pkt, int exclude_slave_port_id)
-{
- // the packet may be changed on snoops, record the original source
- // and command to enable us to restore it between snoops so that
- // additional snoops can take place properly
- Packet::NodeID orig_src_id = pkt->getSrc();
- MemCmd orig_cmd = pkt->cmd;
- MemCmd snoop_response_cmd = MemCmd::InvalidCmd;
- Tick snoop_response_latency = 0;
-
- for (SlavePortIter s = snoopPorts.begin(); s != snoopPorts.end(); ++s) {
- SlavePort *p = *s;
- // we could have gotten this request from a snooping master
- // (corresponding to our own slave port that is also in
- // snoopPorts) and should not send it back to where it came
- // from
- if (exclude_slave_port_id == Port::INVALID_PORT_ID ||
- p->getId() != exclude_slave_port_id) {
- Tick latency = p->sendAtomicSnoop(pkt);
- // in contrast to a functional access, we have to keep on
- // going as all snoopers must be updated even if we get a
- // response
- if (pkt->isResponse()) {
- // response from snoop agent
- assert(pkt->cmd != orig_cmd);
- assert(pkt->memInhibitAsserted());
- // should only happen once
- assert(snoop_response_cmd == MemCmd::InvalidCmd);
- // save response state
- snoop_response_cmd = pkt->cmd;
- snoop_response_latency = latency;
- // restore original packet state for remaining snoopers
- pkt->cmd = orig_cmd;
- pkt->setSrc(orig_src_id);
- pkt->clearDest();
+ defaultRange = ranges.front();
+ }
+ } else {
+ // the ports are allowed to update their address ranges
+ // dynamically, so remove any existing entries
+ if (gotAddrRanges[master_port_id]) {
+ for (PortMapIter p = portMap.begin(); p != portMap.end(); ) {
+ if (p->second == master_port_id)
+ // erasing invalidates the iterator, so advance it
+ // before the deletion takes place
+ portMap.erase(p++);
+ else
+ p++;
}
}
- }
- // the packet is restored as part of the loop and any potential
- // snoop response is part of the returned pair
- return std::make_pair(snoop_response_cmd, snoop_response_latency);
-}
-
-void
-Bus::recvFunctional(PacketPtr pkt)
-{
- if (!pkt->isPrint()) {
- // don't do DPRINTFs on PrintReq as it clutters up the output
- DPRINTF(Bus,
- "recvFunctional: packet src %s addr 0x%x cmd %s\n",
- slavePorts[pkt->getSrc()]->name(), pkt->getAddr(),
- pkt->cmdString());
- }
-
- // forward to all snoopers but the source
- forwardFunctional(pkt, pkt->getSrc());
+ AddrRangeList ranges = masterPorts[master_port_id]->getAddrRanges();
- // there is no need to continue if the snooping has found what we
- // were looking for and the packet is already a response
- if (!pkt->isResponse()) {
- int dest_id = findPort(pkt->getAddr());
-
- masterPorts[dest_id]->sendFunctional(pkt);
- }
-}
-
-void
-Bus::recvFunctionalSnoop(PacketPtr pkt)
-{
- if (!pkt->isPrint()) {
- // don't do DPRINTFs on PrintReq as it clutters up the output
- DPRINTF(Bus,
- "recvFunctionalSnoop: packet src %s addr 0x%x cmd %s\n",
- masterPorts[pkt->getSrc()]->name(), pkt->getAddr(),
- pkt->cmdString());
- }
-
- // forward to all snoopers
- forwardFunctional(pkt, Port::INVALID_PORT_ID);
-}
-
-void
-Bus::forwardFunctional(PacketPtr pkt, int exclude_slave_port_id)
-{
- for (SlavePortIter s = snoopPorts.begin(); s != snoopPorts.end(); ++s) {
- SlavePort *p = *s;
- // we could have gotten this request from a snooping master
- // (corresponding to our own slave port that is also in
- // snoopPorts) and should not send it back to where it came
- // from
- if (exclude_slave_port_id == Port::INVALID_PORT_ID ||
- p->getId() != exclude_slave_port_id)
- p->sendFunctionalSnoop(pkt);
-
- // if we get a response we are done
- if (pkt->isResponse()) {
- break;
+ for (AddrRangeConstIter r = ranges.begin(); r != ranges.end(); ++r) {
+ DPRINTF(BusAddrRanges, "Adding range %s for id %d\n",
+ r->to_string(), master_port_id);
+ if (portMap.insert(*r, master_port_id) == portMap.end()) {
+ PortID conflict_id = portMap.find(*r)->second;
+ fatal("%s has two ports with same range:\n\t%s\n\t%s\n",
+ name(),
+ masterPorts[master_port_id]->getSlavePort().name(),
+ masterPorts[conflict_id]->getSlavePort().name());
+ }
}
}
-}
-/** Function called by the port when the bus is receiving a range change.*/
-void
-Bus::recvRangeChange(Port::PortId id)
-{
- AddrRangeList ranges;
- AddrRangeIter iter;
+ // if we have received ranges from all our neighbouring slave
+ // modules, go ahead and tell our connected master modules in
+ // turn, this effectively assumes a tree structure of the system
+ if (gotAllAddrRanges) {
+ DPRINTF(BusAddrRanges, "Aggregating bus ranges\n");
+ busRanges.clear();
- if (inRecvRangeChange.count(id))
- return;
- inRecvRangeChange.insert(id);
+ // start out with the default range
+ if (useDefaultRange) {
+ if (!gotAddrRanges[defaultPortID])
+ fatal("Bus %s uses default range, but none provided",
+ name());
- DPRINTF(BusAddrRanges, "received RangeChange from device id %d\n", id);
+ busRanges.push_back(defaultRange);
+ DPRINTF(BusAddrRanges, "-- Adding default %s\n",
+ defaultRange.to_string());
+ }
- clearPortCache();
- if (id == defaultPortId) {
- defaultRange.clear();
- // Only try to update these ranges if the user set a default responder.
- if (useDefaultRange) {
- AddrRangeList ranges =
- masterPorts[id]->getSlavePort().getAddrRanges();
- for(iter = ranges.begin(); iter != ranges.end(); iter++) {
- defaultRange.push_back(*iter);
- DPRINTF(BusAddrRanges, "Adding range %#llx - %#llx for default range\n",
- iter->start, iter->end);
+ // merge all interleaved ranges and add any range that is not
+ // a subset of the default range
+ std::vector<AddrRange> intlv_ranges;
+ for (AddrRangeMap<PortID>::const_iterator r = portMap.begin();
+ r != portMap.end(); ++r) {
+ // if the range is interleaved then save it for now
+ if (r->first.interleaved()) {
+ // if we already got interleaved ranges that are not
+ // part of the same range, then first do a merge
+ // before we add the new one
+ if (!intlv_ranges.empty() &&
+ !intlv_ranges.back().mergesWith(r->first)) {
+ DPRINTF(BusAddrRanges, "-- Merging range from %d ranges\n",
+ intlv_ranges.size());
+ AddrRange merged_range(intlv_ranges);
+ // next decide if we keep the merged range or not
+ if (!(useDefaultRange &&
+ merged_range.isSubset(defaultRange))) {
+ busRanges.push_back(merged_range);
+ DPRINTF(BusAddrRanges, "-- Adding merged range %s\n",
+ merged_range.to_string());
+ }
+ intlv_ranges.clear();
+ }
+ intlv_ranges.push_back(r->first);
+ } else {
+ // keep the current range if not a subset of the default
+ if (!(useDefaultRange &&
+ r->first.isSubset(defaultRange))) {
+ busRanges.push_back(r->first);
+ DPRINTF(BusAddrRanges, "-- Adding range %s\n",
+ r->first.to_string());
+ }
}
}
- } else {
-
- assert(id < masterPorts.size() && id >= 0);
- MasterPort *port = masterPorts[id];
- // Clean out any previously existent ids
- for (PortIter portIter = portMap.begin();
- portIter != portMap.end(); ) {
- if (portIter->second == id)
- portMap.erase(portIter++);
- else
- portIter++;
+ // if there is still interleaved ranges waiting to be merged,
+ // go ahead and do it
+ if (!intlv_ranges.empty()) {
+ DPRINTF(BusAddrRanges, "-- Merging range from %d ranges\n",
+ intlv_ranges.size());
+ AddrRange merged_range(intlv_ranges);
+ if (!(useDefaultRange && merged_range.isSubset(defaultRange))) {
+ busRanges.push_back(merged_range);
+ DPRINTF(BusAddrRanges, "-- Adding merged range %s\n",
+ merged_range.to_string());
+ }
}
- ranges = port->getSlavePort().getAddrRanges();
-
- for (iter = ranges.begin(); iter != ranges.end(); iter++) {
- DPRINTF(BusAddrRanges, "Adding range %#llx - %#llx for id %d\n",
- iter->start, iter->end, id);
- if (portMap.insert(*iter, id) == portMap.end()) {
- int conflict_id = portMap.find(*iter)->second;
- fatal("%s has two ports with same range:\n\t%s\n\t%s\n",
- name(), masterPorts[id]->getSlavePort().name(),
- masterPorts[conflict_id]->getSlavePort().name());
+ // also check that no range partially overlaps with the
+ // default range, this has to be done after all ranges are set
+ // as there are no guarantees for when the default range is
+ // update with respect to the other ones
+ if (useDefaultRange) {
+ for (AddrRangeConstIter r = busRanges.begin();
+ r != busRanges.end(); ++r) {
+ // see if the new range is partially
+ // overlapping the default range
+ if (r->intersects(defaultRange) &&
+ !r->isSubset(defaultRange))
+ fatal("Range %s intersects the " \
+ "default range of %s but is not a " \
+ "subset\n", r->to_string(), name());
}
}
- }
- DPRINTF(BusAddrRanges, "port list has %d entries\n", portMap.size());
- // tell all our neighbouring master ports that our address range
- // has changed
- for (SlavePortConstIter p = slavePorts.begin(); p != slavePorts.end();
- ++p)
- (*p)->sendRangeChange();
+ // tell all our neighbouring master ports that our address
+ // ranges have changed
+ for (SlavePortConstIter s = slavePorts.begin(); s != slavePorts.end();
+ ++s)
+ (*s)->sendRangeChange();
+ }
- inRecvRangeChange.erase(id);
+ clearPortCache();
}
AddrRangeList
-Bus::getAddrRanges(Port::PortId id)
+BaseBus::getAddrRanges() const
{
- AddrRangeList ranges;
+ // we should never be asked without first having sent a range
+ // change, and the latter is only done once we have all the ranges
+ // of the connected devices
+ assert(gotAllAddrRanges);
- DPRINTF(BusAddrRanges, "received address range request, returning:\n");
+ // at the moment, this never happens, as there are no cycles in
+ // the range queries and no devices on the master side of a bus
+ // (CPU, cache, bridge etc) actually care about the ranges of the
+ // ports they are connected to
- for (AddrRangeIter dflt_iter = defaultRange.begin();
- dflt_iter != defaultRange.end(); dflt_iter++) {
- ranges.push_back(*dflt_iter);
- DPRINTF(BusAddrRanges, " -- Dflt: %#llx : %#llx\n",dflt_iter->start,
- dflt_iter->end);
- }
- for (PortIter portIter = portMap.begin();
- portIter != portMap.end(); portIter++) {
- bool subset = false;
- for (AddrRangeIter dflt_iter = defaultRange.begin();
- dflt_iter != defaultRange.end(); dflt_iter++) {
- if ((portIter->first.start < dflt_iter->start &&
- portIter->first.end >= dflt_iter->start) ||
- (portIter->first.start < dflt_iter->end &&
- portIter->first.end >= dflt_iter->end))
- fatal("Devices can not set ranges that itersect the default set\
- but are not a subset of the default set.\n");
- if (portIter->first.start >= dflt_iter->start &&
- portIter->first.end <= dflt_iter->end) {
- subset = true;
- DPRINTF(BusAddrRanges, " -- %#llx : %#llx is a SUBSET\n",
- portIter->first.start, portIter->first.end);
- }
- }
- if (portIter->second != id && !subset) {
- ranges.push_back(portIter->first);
- DPRINTF(BusAddrRanges, " -- %#llx : %#llx\n",
- portIter->first.start, portIter->first.end);
- }
- }
-
- return ranges;
-}
+ DPRINTF(BusAddrRanges, "Received address range request\n");
-bool
-Bus::isSnooping(Port::PortId id) const
-{
- // in essence, answer the question if there are snooping ports
- return !snoopPorts.empty();
+ return busRanges;
}
unsigned
-Bus::findBlockSize(Port::PortId id)
+BaseBus::deviceBlockSize() const
{
- if (cachedBlockSizeValid)
- return cachedBlockSize;
-
- unsigned max_bs = 0;
-
- PortIter p_end = portMap.end();
- for (PortIter p_iter = portMap.begin(); p_iter != p_end; p_iter++) {
- unsigned tmp_bs = masterPorts[p_iter->second]->peerBlockSize();
- if (tmp_bs > max_bs)
- max_bs = tmp_bs;
- }
-
- for (SlavePortConstIter s = snoopPorts.begin(); s != snoopPorts.end();
- ++s) {
- unsigned tmp_bs = (*s)->peerBlockSize();
- if (tmp_bs > max_bs)
- max_bs = tmp_bs;
- }
- if (max_bs == 0)
- max_bs = defaultBlockSize;
-
- if (max_bs != 64)
- warn_once("Blocksize found to not be 64... hmm... probably not.\n");
- cachedBlockSize = max_bs;
- cachedBlockSizeValid = true;
- return max_bs;
+ return blockSize;
}
-
+template <typename PortClass>
unsigned int
-Bus::drain(Event * de)
+BaseBus::Layer<PortClass>::drain(DrainManager *dm)
{
//We should check that we're not "doing" anything, and that noone is
//waiting. We might be idle but have someone waiting if the device we
//contacted for a retry didn't actually retry.
- if (!retryList.empty() || (curTick() < tickNextIdle &&
- busIdleEvent.scheduled())) {
- drainEvent = de;
+ if (!retryList.empty() || state != IDLE) {
+ DPRINTF(Drain, "Bus not drained\n");
+ drainManager = dm;
return 1;
}
return 0;
}
-void
-Bus::startup()
-{
- if (tickNextIdle < curTick())
- tickNextIdle = (curTick() / clock) * clock + clock;
-}
-
-Bus *
-BusParams::create()
-{
- return new Bus(this);
-}
+/**
+ * Bus layer template instantiations. Could be removed with _impl.hh
+ * file, but since there are only two given options (MasterPort and
+ * SlavePort) it seems a bit excessive at this point.
+ */
+template class BaseBus::Layer<SlavePort>;
+template class BaseBus::Layer<MasterPort>;
projects / gem5.git / blobdiff