X-Git-Url: https://git.libre-soc.org/?a=blobdiff_plain;f=src%2Fmem%2Fbridge.cc;h=e9dc68a030570b9ff18278fb1e7d2845a03d34d8;hb=6721b3e325139fb4ace99d858f0bdec44ec6af1b;hp=6cfa5a2ac3a2de7f84fc10720896f9e7fc69af1c;hpb=142362b703e666f82c6b1f57e2d729e0641be166;p=gem5.git diff --git a/src/mem/bridge.cc b/src/mem/bridge.cc index 6cfa5a2ac..e9dc68a03 100644 --- a/src/mem/bridge.cc +++ b/src/mem/bridge.cc @@ -1,5 +1,16 @@ - /* + * Copyright (c) 2011-2012 ARM Limited + * All rights reserved + * + * The license below extends only to copyright in the software and shall + * not be construed as granting a license to any other intellectual + * property including but not limited to intellectual property relating + * to a hardware implementation of the functionality of the software + * licensed hereunder. You may use the software subject to the license + * terms below provided that you ensure that this notice is replicated + * unmodified and in its entirety in all distributions of the software, + * modified or unmodified, in source code or in binary form. + * * Copyright (c) 2006 The Regents of The University of Michigan * All rights reserved. * @@ -28,160 +39,198 @@ * * Authors: Ali Saidi * Steve Reinhardt + * Andreas Hansson */ /** * @file - * Definition of a simple bus bridge without buffering. + * Implementation of a memory-mapped bus bridge that connects a master + * and a slave through a request and response queue. */ -#include - #include "base/trace.hh" +#include "debug/BusBridge.hh" #include "mem/bridge.hh" #include "params/Bridge.hh" -Bridge::BridgePort::BridgePort(const std::string &_name, - Bridge *_bridge, BridgePort *_otherPort, - int _delay, int _nack_delay, int _req_limit, - int _resp_limit, bool fix_partial_write) - : Port(_name), bridge(_bridge), otherPort(_otherPort), - delay(_delay), nackDelay(_nack_delay), fixPartialWrite(fix_partial_write), - outstandingResponses(0), queuedRequests(0), inRetry(false), - reqQueueLimit(_req_limit), respQueueLimit(_resp_limit), sendEvent(this) +Bridge::BridgeSlavePort::BridgeSlavePort(const std::string &_name, + Bridge* _bridge, + BridgeMasterPort& _masterPort, + int _delay, int _nack_delay, + int _resp_limit, + std::vector > _ranges) + : SlavePort(_name, _bridge), bridge(_bridge), masterPort(_masterPort), + delay(_delay), nackDelay(_nack_delay), + ranges(_ranges.begin(), _ranges.end()), + outstandingResponses(0), inRetry(false), + respQueueLimit(_resp_limit), sendEvent(*this) +{ +} + +Bridge::BridgeMasterPort::BridgeMasterPort(const std::string &_name, + Bridge* _bridge, + BridgeSlavePort& _slavePort, + int _delay, int _req_limit) + : MasterPort(_name, _bridge), bridge(_bridge), slavePort(_slavePort), + delay(_delay), inRetry(false), reqQueueLimit(_req_limit), + sendEvent(*this) { } 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), + : MemObject(p), + slavePort(p->name + ".slave", this, masterPort, p->delay, + p->nack_delay, p->resp_size, p->ranges), + masterPort(p->name + ".master", this, slavePort, p->delay, p->req_size), ackWrites(p->write_ack), _params(p) { if (ackWrites) panic("No support for acknowledging writes\n"); } -Port * -Bridge::getPort(const std::string &if_name, int idx) +MasterPort& +Bridge::getMasterPort(const std::string &if_name, int idx) { - BridgePort *port; - - if (if_name == "side_a") - port = &portA; - else if (if_name == "side_b") - port = &portB; + if (if_name == "master") + return masterPort; else - return NULL; - - if (port->getPeer() != NULL) - panic("bridge side %s already connected to.", if_name); - return port; + // pass it along to our super class + return MemObject::getMasterPort(if_name, idx); } +SlavePort& +Bridge::getSlavePort(const std::string &if_name, int idx) +{ + if (if_name == "slave") + return slavePort; + else + // pass it along to our super class + return MemObject::getSlavePort(if_name, idx); +} void Bridge::init() { - // Make sure that both sides are connected to. - if (portA.getPeer() == NULL || portB.getPeer() == NULL) + // make sure both sides are connected and have the same block size + if (!slavePort.isConnected() || !masterPort.isConnected()) fatal("Both ports of bus bridge are not connected to a bus.\n"); - if (portA.peerBlockSize() != portB.peerBlockSize()) - fatal("Busses don't have the same block size... Not supported.\n"); + if (slavePort.peerBlockSize() != masterPort.peerBlockSize()) + fatal("Slave port size %d, master port size %d \n " \ + "Busses don't have the same block size... Not supported.\n", + slavePort.peerBlockSize(), masterPort.peerBlockSize()); + + // notify the master side of our address ranges + slavePort.sendRangeChange(); } bool -Bridge::BridgePort::respQueueFull() +Bridge::BridgeSlavePort::respQueueFull() { - assert(outstandingResponses >= 0 && outstandingResponses <= respQueueLimit); - return outstandingResponses >= respQueueLimit; + return outstandingResponses == respQueueLimit; } bool -Bridge::BridgePort::reqQueueFull() +Bridge::BridgeMasterPort::reqQueueFull() { - assert(queuedRequests >= 0 && queuedRequests <= reqQueueLimit); - return queuedRequests >= reqQueueLimit; + return requestQueue.size() == reqQueueLimit; +} + +bool +Bridge::BridgeMasterPort::recvTimingResp(PacketPtr pkt) +{ + // all checks are done when the request is accepted on the slave + // side, so we are guaranteed to have space for the response + DPRINTF(BusBridge, "recvTiming: response %s addr 0x%x\n", + pkt->cmdString(), pkt->getAddr()); + + DPRINTF(BusBridge, "Request queue size: %d\n", requestQueue.size()); + + slavePort.queueForSendTiming(pkt); + + return true; } -/** Function called by the port when the bus is receiving a Timing - * transaction.*/ bool -Bridge::BridgePort::recvTiming(PacketPtr pkt) +Bridge::BridgeSlavePort::recvTimingReq(PacketPtr pkt) { - DPRINTF(BusBridge, "recvTiming: src %d dest %d addr 0x%x\n", - pkt->getSrc(), pkt->getDest(), pkt->getAddr()); + DPRINTF(BusBridge, "recvTiming: request %s addr 0x%x\n", + pkt->cmdString(), pkt->getAddr()); - DPRINTF(BusBridge, "Local queue size: %d outreq: %d outresp: %d\n", - sendQueue.size(), queuedRequests, outstandingResponses); - DPRINTF(BusBridge, "Remove queue size: %d outreq: %d outresp: %d\n", - otherPort->sendQueue.size(), otherPort->queuedRequests, - otherPort->outstandingResponses); + DPRINTF(BusBridge, "Response queue size: %d outresp: %d\n", + responseQueue.size(), outstandingResponses); - if (pkt->isRequest() && otherPort->reqQueueFull() && !pkt->wasNacked()) { - DPRINTF(BusBridge, "Remote queue full, nacking\n"); + if (masterPort.reqQueueFull()) { + DPRINTF(BusBridge, "Request queue full, nacking\n"); nackRequest(pkt); return true; } - if (pkt->needsResponse() && !pkt->wasNacked()) + if (pkt->needsResponse()) { 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); + DPRINTF(BusBridge, + "Response queue full, no space for response, nacking\n"); + DPRINTF(BusBridge, + "queue size: %d outstanding resp: %d\n", + responseQueue.size(), outstandingResponses); nackRequest(pkt); return true; } else { DPRINTF(BusBridge, "Request Needs response, reserving space\n"); + assert(outstandingResponses != respQueueLimit); ++outstandingResponses; } + } - otherPort->queueForSendTiming(pkt); + masterPort.queueForSendTiming(pkt); return true; } void -Bridge::BridgePort::nackRequest(PacketPtr pkt) +Bridge::BridgeSlavePort::nackRequest(PacketPtr pkt) { // Nack the packet + pkt->makeTimingResponse(); pkt->setNacked(); - pkt->setDest(pkt->getSrc()); - //put it on the list to send - Tick readyTime = curTick + nackDelay; - PacketBuffer *buf = new PacketBuffer(pkt, readyTime, true); + // The Nack packets are stored in the response queue just like any + // other response, but they do not occupy any space as this is + // tracked by the outstandingResponses, this guarantees space for + // the Nack packets, but implicitly means we have an (unrealistic) + // unbounded Nack queue. + + // put it on the list to send + Tick readyTime = curTick() + nackDelay; + DeferredResponse resp(pkt, readyTime, true); // nothing on the list, add it and we're done - if (sendQueue.empty()) { + if (responseQueue.empty()) { assert(!sendEvent.scheduled()); - sendEvent.schedule(readyTime); - sendQueue.push_back(buf); + bridge->schedule(sendEvent, readyTime); + responseQueue.push_back(resp); return; } assert(sendEvent.scheduled() || inRetry); // does it go at the end? - if (readyTime >= sendQueue.back()->ready) { - sendQueue.push_back(buf); + if (readyTime >= responseQueue.back().ready) { + responseQueue.push_back(resp); return; } // ok, somewhere in the middle, fun - std::list::iterator i = sendQueue.begin(); - std::list::iterator end = sendQueue.end(); - std::list::iterator begin = sendQueue.begin(); + std::list::iterator i = responseQueue.begin(); + std::list::iterator end = responseQueue.end(); + std::list::iterator begin = responseQueue.begin(); bool done = false; while (i != end && !done) { - if (readyTime < (*i)->ready) { + if (readyTime < (*i).ready) { if (i == begin) - sendEvent.reschedule(readyTime); - sendQueue.insert(i,buf); + bridge->reschedule(sendEvent, readyTime); + responseQueue.insert(i, resp); done = true; } i++; @@ -189,174 +238,214 @@ Bridge::BridgePort::nackRequest(PacketPtr pkt) assert(done); } - void -Bridge::BridgePort::queueForSendTiming(PacketPtr pkt) +Bridge::BridgeMasterPort::queueForSendTiming(PacketPtr pkt) { - if (pkt->isResponse() || pkt->wasNacked()) { - // This is a response for a request we forwarded earlier. The - // corresponding PacketBuffer should be stored in the packet's - // senderState field. - PacketBuffer *buf = dynamic_cast(pkt->senderState); - assert(buf != NULL); - // set up new packet dest & senderState based on values saved - // from original request - buf->fixResponse(pkt); - - // Check if this packet was expecting a response and it's a nacked - // packet, in which case we will never being seeing it - if (buf->expectResponse && pkt->wasNacked()) - --outstandingResponses; - - DPRINTF(BusBridge, "response, new dest %d\n", pkt->getDest()); - delete buf; + Tick readyTime = curTick() + delay; + + // If we expect to see a response, we need to restore the source + // and destination field that is potentially changed by a second + // bus + if (!pkt->memInhibitAsserted() && pkt->needsResponse()) { + // Update the sender state so we can deal with the response + // appropriately + RequestState *req_state = new RequestState(pkt); + pkt->senderState = req_state; } - - if (pkt->isRequest() && !pkt->wasNacked()) { - ++queuedRequests; + // If we're about to put this packet at the head of the queue, we + // need to schedule an event to do the transmit. Otherwise there + // should already be an event scheduled for sending the head + // packet. + if (requestQueue.empty()) { + bridge->schedule(sendEvent, readyTime); } + assert(requestQueue.size() != reqQueueLimit); + requestQueue.push_back(DeferredRequest(pkt, readyTime)); +} - Tick readyTime = curTick + delay; - PacketBuffer *buf = new PacketBuffer(pkt, readyTime); + +void +Bridge::BridgeSlavePort::queueForSendTiming(PacketPtr pkt) +{ + // This is a response for a request we forwarded earlier. The + // corresponding request state should be stored in the packet's + // senderState field. + RequestState *req_state = dynamic_cast(pkt->senderState); + assert(req_state != NULL); + // set up new packet dest & senderState based on values saved + // from original request + req_state->fixResponse(pkt); + + // the bridge assumes that at least one bus has set the + // destination field of the packet + assert(pkt->isDestValid()); + DPRINTF(BusBridge, "response, new dest %d\n", pkt->getDest()); + delete req_state; + + Tick readyTime = curTick() + delay; // If we're about to put this packet at the head of the queue, we // need to schedule an event to do the transmit. Otherwise there // should already be an event scheduled for sending the head // packet. - if (sendQueue.empty()) { - sendEvent.schedule(readyTime); + if (responseQueue.empty()) { + bridge->schedule(sendEvent, readyTime); } - sendQueue.push_back(buf); + responseQueue.push_back(DeferredResponse(pkt, readyTime)); } void -Bridge::BridgePort::trySend() +Bridge::BridgeMasterPort::trySend() { - assert(!sendQueue.empty()); + assert(!requestQueue.empty()); + + DeferredRequest req = requestQueue.front(); - PacketBuffer *buf = sendQueue.front(); + assert(req.ready <= curTick()); - assert(buf->ready <= curTick); + PacketPtr pkt = req.pkt; - PacketPtr pkt = buf->pkt; + DPRINTF(BusBridge, "trySend request: addr 0x%x\n", pkt->getAddr()); + + if (sendTimingReq(pkt)) { + // send successful + requestQueue.pop_front(); - // Ugly! @todo When multilevel coherence works this will be removed - if (pkt->cmd == MemCmd::WriteInvalidateReq && fixPartialWrite && - !pkt->wasNacked()) { - PacketPtr funcPkt = new Packet(pkt->req, MemCmd::WriteReq, - Packet::Broadcast); - funcPkt->dataStatic(pkt->getPtr()); - sendFunctional(funcPkt); - pkt->cmd = MemCmd::WriteReq; - delete funcPkt; + // If there are more packets to send, schedule event to try again. + if (!requestQueue.empty()) { + req = requestQueue.front(); + DPRINTF(BusBridge, "Scheduling next send\n"); + bridge->schedule(sendEvent, + std::max(req.ready, curTick() + 1)); + } + } else { + inRetry = true; } - DPRINTF(BusBridge, "trySend: origSrc %d dest %d addr 0x%x\n", - buf->origSrc, pkt->getDest(), pkt->getAddr()); + DPRINTF(BusBridge, "trySend: request queue size: %d\n", + requestQueue.size()); +} - bool wasReq = pkt->isRequest(); - bool wasNacked = pkt->wasNacked(); +void +Bridge::BridgeSlavePort::trySend() +{ + assert(!responseQueue.empty()); - if (sendTiming(pkt)) { - // send successful - sendQueue.pop_front(); - buf->pkt = NULL; // we no longer own packet, so it's not safe to look at it + DeferredResponse resp = responseQueue.front(); - if (buf->expectResponse) { - // Must wait for response - DPRINTF(BusBridge, " successful: awaiting response (%d)\n", - outstandingResponses); - } else { - // no response expected... deallocate packet buffer now. - DPRINTF(BusBridge, " successful: no response expected\n"); - delete buf; - } + assert(resp.ready <= curTick()); + + PacketPtr pkt = resp.pkt; + + DPRINTF(BusBridge, "trySend response: dest %d addr 0x%x\n", + pkt->getDest(), pkt->getAddr()); - if (!wasNacked) { - if (wasReq) - --queuedRequests; - else - --outstandingResponses; + bool was_nacked_here = resp.nackedHere; + + if (sendTimingResp(pkt)) { + DPRINTF(BusBridge, " successful\n"); + // send successful + responseQueue.pop_front(); + + if (!was_nacked_here) { + assert(outstandingResponses != 0); + --outstandingResponses; } // If there are more packets to send, schedule event to try again. - if (!sendQueue.empty()) { - buf = sendQueue.front(); + if (!responseQueue.empty()) { + resp = responseQueue.front(); DPRINTF(BusBridge, "Scheduling next send\n"); - sendEvent.schedule(std::max(buf->ready, curTick + 1)); + bridge->schedule(sendEvent, + std::max(resp.ready, curTick() + 1)); } } else { DPRINTF(BusBridge, " unsuccessful\n"); inRetry = true; } - DPRINTF(BusBridge, "trySend: queue size: %d outreq: %d outstanding resp: %d\n", - sendQueue.size(), queuedRequests, outstandingResponses); + + DPRINTF(BusBridge, "trySend: queue size: %d outstanding resp: %d\n", + responseQueue.size(), outstandingResponses); } +void +Bridge::BridgeMasterPort::recvRetry() +{ + inRetry = false; + Tick nextReady = requestQueue.front().ready; + if (nextReady <= curTick()) + trySend(); + else + bridge->schedule(sendEvent, nextReady); +} void -Bridge::BridgePort::recvRetry() +Bridge::BridgeSlavePort::recvRetry() { inRetry = false; - Tick nextReady = sendQueue.front()->ready; - if (nextReady <= curTick) + Tick nextReady = responseQueue.front().ready; + if (nextReady <= curTick()) trySend(); else - sendEvent.schedule(nextReady); + bridge->schedule(sendEvent, nextReady); } -/** Function called by the port when the bus is receiving a Atomic - * transaction.*/ Tick -Bridge::BridgePort::recvAtomic(PacketPtr pkt) +Bridge::BridgeSlavePort::recvAtomic(PacketPtr pkt) { - // fix partial atomic writes... similar to the timing code that does the - // same... will be removed once our code gets this right - if (pkt->cmd == MemCmd::WriteInvalidateReq && fixPartialWrite) { - - PacketPtr funcPkt = new Packet(pkt->req, MemCmd::WriteReq, - Packet::Broadcast); - funcPkt->dataStatic(pkt->getPtr()); - otherPort->sendFunctional(funcPkt); - delete funcPkt; - pkt->cmd = MemCmd::WriteReq; - } - return delay + otherPort->sendAtomic(pkt); + return delay + masterPort.sendAtomic(pkt); } -/** Function called by the port when the bus is receiving a Functional - * transaction.*/ void -Bridge::BridgePort::recvFunctional(PacketPtr pkt) +Bridge::BridgeSlavePort::recvFunctional(PacketPtr pkt) { - std::list::iterator i; + std::list::iterator i; + + pkt->pushLabel(name()); - for (i = sendQueue.begin(); i != sendQueue.end(); ++i) { - if (pkt->checkFunctional((*i)->pkt)) + // check the response queue + for (i = responseQueue.begin(); i != responseQueue.end(); ++i) { + if (pkt->checkFunctional((*i).pkt)) { + pkt->makeResponse(); return; + } } + // also check the master port's request queue + if (masterPort.checkFunctional(pkt)) { + return; + } + + pkt->popLabel(); + // fall through if pkt still not satisfied - otherPort->sendFunctional(pkt); + masterPort.sendFunctional(pkt); } -/** Function called by the port when the bus is receiving a status change.*/ -void -Bridge::BridgePort::recvStatusChange(Port::Status status) +bool +Bridge::BridgeMasterPort::checkFunctional(PacketPtr pkt) { - otherPort->sendStatusChange(status); + bool found = false; + std::list::iterator i = requestQueue.begin(); + + while(i != requestQueue.end() && !found) { + if (pkt->checkFunctional((*i).pkt)) { + pkt->makeResponse(); + found = true; + } + ++i; + } + + return found; } -void -Bridge::BridgePort::getDeviceAddressRanges(AddrRangeList &resp, - bool &snoop) +AddrRangeList +Bridge::BridgeSlavePort::getAddrRanges() const { - otherPort->getPeerAddressRanges(resp, snoop); - // we don't allow snooping across bridges - snoop = false; + return ranges; } Bridge *