bridge.cc revision 4986
12568SN/A 22568SN/A/* 32568SN/A * Copyright (c) 2006 The Regents of The University of Michigan 42568SN/A * All rights reserved. 52568SN/A * 62568SN/A * Redistribution and use in source and binary forms, with or without 72568SN/A * modification, are permitted provided that the following conditions are 82568SN/A * met: redistributions of source code must retain the above copyright 92568SN/A * notice, this list of conditions and the following disclaimer; 102568SN/A * redistributions in binary form must reproduce the above copyright 112568SN/A * notice, this list of conditions and the following disclaimer in the 122568SN/A * documentation and/or other materials provided with the distribution; 132568SN/A * neither the name of the copyright holders nor the names of its 142568SN/A * contributors may be used to endorse or promote products derived from 152568SN/A * this software without specific prior written permission. 162568SN/A * 172568SN/A * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 182568SN/A * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 192568SN/A * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 202568SN/A * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 212568SN/A * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 222568SN/A * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 232568SN/A * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 242568SN/A * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 252568SN/A * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 262568SN/A * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 272568SN/A * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 282665Ssaidi@eecs.umich.edu * 292665Ssaidi@eecs.umich.edu * Authors: Ali Saidi 302665Ssaidi@eecs.umich.edu * Steve Reinhardt 312568SN/A */ 322568SN/A 332568SN/A/** 342982Sstever@eecs.umich.edu * @file 352982Sstever@eecs.umich.edu * Definition of a simple bus bridge without buffering. 362568SN/A */ 372568SN/A 382643Sstever@eecs.umich.edu#include <algorithm> 392568SN/A 404965Ssaidi@eecs.umich.edu#include "base/range_ops.hh" 412568SN/A#include "base/trace.hh" 422568SN/A#include "mem/bridge.hh" 434762Snate@binkert.org#include "params/Bridge.hh" 442568SN/A 452643Sstever@eecs.umich.eduBridge::BridgePort::BridgePort(const std::string &_name, 462643Sstever@eecs.umich.edu Bridge *_bridge, BridgePort *_otherPort, 474435Ssaidi@eecs.umich.edu int _delay, int _nack_delay, int _req_limit, 484965Ssaidi@eecs.umich.edu int _resp_limit, 494965Ssaidi@eecs.umich.edu std::vector<Range<Addr> > filter_ranges) 502643Sstever@eecs.umich.edu : Port(_name), bridge(_bridge), otherPort(_otherPort), 514965Ssaidi@eecs.umich.edu delay(_delay), nackDelay(_nack_delay), filterRanges(filter_ranges), 524435Ssaidi@eecs.umich.edu outstandingResponses(0), queuedRequests(0), inRetry(false), 534435Ssaidi@eecs.umich.edu reqQueueLimit(_req_limit), respQueueLimit(_resp_limit), sendEvent(this) 542643Sstever@eecs.umich.edu{ 552643Sstever@eecs.umich.edu} 562643Sstever@eecs.umich.edu 574435Ssaidi@eecs.umich.eduBridge::Bridge(Params *p) 584435Ssaidi@eecs.umich.edu : MemObject(p->name), 594435Ssaidi@eecs.umich.edu portA(p->name + "-portA", this, &portB, p->delay, p->nack_delay, 604965Ssaidi@eecs.umich.edu p->req_size_a, p->resp_size_a, p->filter_ranges_a), 614435Ssaidi@eecs.umich.edu portB(p->name + "-portB", this, &portA, p->delay, p->nack_delay, 624965Ssaidi@eecs.umich.edu p->req_size_b, p->resp_size_b, p->filter_ranges_b), 634435Ssaidi@eecs.umich.edu ackWrites(p->write_ack), _params(p) 642643Sstever@eecs.umich.edu{ 654432Ssaidi@eecs.umich.edu if (ackWrites) 664432Ssaidi@eecs.umich.edu panic("No support for acknowledging writes\n"); 672643Sstever@eecs.umich.edu} 682643Sstever@eecs.umich.edu 692643Sstever@eecs.umich.eduPort * 702738Sstever@eecs.umich.eduBridge::getPort(const std::string &if_name, int idx) 712643Sstever@eecs.umich.edu{ 722643Sstever@eecs.umich.edu BridgePort *port; 732643Sstever@eecs.umich.edu 742643Sstever@eecs.umich.edu if (if_name == "side_a") 752643Sstever@eecs.umich.edu port = &portA; 762643Sstever@eecs.umich.edu else if (if_name == "side_b") 772643Sstever@eecs.umich.edu port = &portB; 782643Sstever@eecs.umich.edu else 792643Sstever@eecs.umich.edu return NULL; 802643Sstever@eecs.umich.edu 812643Sstever@eecs.umich.edu if (port->getPeer() != NULL) 822643Sstever@eecs.umich.edu panic("bridge side %s already connected to.", if_name); 832643Sstever@eecs.umich.edu return port; 842643Sstever@eecs.umich.edu} 852643Sstever@eecs.umich.edu 862643Sstever@eecs.umich.edu 872568SN/Avoid 882568SN/ABridge::init() 892568SN/A{ 902568SN/A // Make sure that both sides are connected to. 912643Sstever@eecs.umich.edu if (portA.getPeer() == NULL || portB.getPeer() == NULL) 924432Ssaidi@eecs.umich.edu fatal("Both ports of bus bridge are not connected to a bus.\n"); 934432Ssaidi@eecs.umich.edu 944432Ssaidi@eecs.umich.edu if (portA.peerBlockSize() != portB.peerBlockSize()) 954432Ssaidi@eecs.umich.edu fatal("Busses don't have the same block size... Not supported.\n"); 962568SN/A} 972568SN/A 984433Ssaidi@eecs.umich.edubool 994435Ssaidi@eecs.umich.eduBridge::BridgePort::respQueueFull() 1004433Ssaidi@eecs.umich.edu{ 1014435Ssaidi@eecs.umich.edu assert(outstandingResponses >= 0 && outstandingResponses <= respQueueLimit); 1024435Ssaidi@eecs.umich.edu return outstandingResponses >= respQueueLimit; 1034435Ssaidi@eecs.umich.edu} 1044435Ssaidi@eecs.umich.edu 1054435Ssaidi@eecs.umich.edubool 1064435Ssaidi@eecs.umich.eduBridge::BridgePort::reqQueueFull() 1074435Ssaidi@eecs.umich.edu{ 1084435Ssaidi@eecs.umich.edu assert(queuedRequests >= 0 && queuedRequests <= reqQueueLimit); 1094435Ssaidi@eecs.umich.edu return queuedRequests >= reqQueueLimit; 1104433Ssaidi@eecs.umich.edu} 1112568SN/A 1122643Sstever@eecs.umich.edu/** Function called by the port when the bus is receiving a Timing 1132568SN/A * transaction.*/ 1142568SN/Abool 1153349Sbinkertn@umich.eduBridge::BridgePort::recvTiming(PacketPtr pkt) 1162568SN/A{ 1174433Ssaidi@eecs.umich.edu DPRINTF(BusBridge, "recvTiming: src %d dest %d addr 0x%x\n", 1183662Srdreslin@umich.edu pkt->getSrc(), pkt->getDest(), pkt->getAddr()); 1192643Sstever@eecs.umich.edu 1204450Ssaidi@eecs.umich.edu DPRINTF(BusBridge, "Local queue size: %d outreq: %d outresp: %d\n", 1214450Ssaidi@eecs.umich.edu sendQueue.size(), queuedRequests, outstandingResponses); 1224986Ssaidi@eecs.umich.edu DPRINTF(BusBridge, "Remote queue size: %d outreq: %d outresp: %d\n", 1234450Ssaidi@eecs.umich.edu otherPort->sendQueue.size(), otherPort->queuedRequests, 1244450Ssaidi@eecs.umich.edu otherPort->outstandingResponses); 1254450Ssaidi@eecs.umich.edu 1264986Ssaidi@eecs.umich.edu if (pkt->isRequest() && otherPort->reqQueueFull()) { 1274433Ssaidi@eecs.umich.edu DPRINTF(BusBridge, "Remote queue full, nacking\n"); 1284433Ssaidi@eecs.umich.edu nackRequest(pkt); 1294433Ssaidi@eecs.umich.edu return true; 1303662Srdreslin@umich.edu } 1314433Ssaidi@eecs.umich.edu 1324986Ssaidi@eecs.umich.edu if (pkt->needsResponse()) 1334435Ssaidi@eecs.umich.edu if (respQueueFull()) { 1344433Ssaidi@eecs.umich.edu DPRINTF(BusBridge, "Local queue full, no space for response, nacking\n"); 1354433Ssaidi@eecs.umich.edu DPRINTF(BusBridge, "queue size: %d outreq: %d outstanding resp: %d\n", 1364433Ssaidi@eecs.umich.edu sendQueue.size(), queuedRequests, outstandingResponses); 1374433Ssaidi@eecs.umich.edu nackRequest(pkt); 1384433Ssaidi@eecs.umich.edu return true; 1394433Ssaidi@eecs.umich.edu } else { 1404433Ssaidi@eecs.umich.edu DPRINTF(BusBridge, "Request Needs response, reserving space\n"); 1414433Ssaidi@eecs.umich.edu ++outstandingResponses; 1424433Ssaidi@eecs.umich.edu } 1434433Ssaidi@eecs.umich.edu 1444433Ssaidi@eecs.umich.edu otherPort->queueForSendTiming(pkt); 1454433Ssaidi@eecs.umich.edu 1464433Ssaidi@eecs.umich.edu return true; 1472657Ssaidi@eecs.umich.edu} 1482657Ssaidi@eecs.umich.edu 1494433Ssaidi@eecs.umich.eduvoid 1504433Ssaidi@eecs.umich.eduBridge::BridgePort::nackRequest(PacketPtr pkt) 1514433Ssaidi@eecs.umich.edu{ 1524433Ssaidi@eecs.umich.edu // Nack the packet 1534986Ssaidi@eecs.umich.edu pkt->makeTimingResponse(); 1544870Sstever@eecs.umich.edu pkt->setNacked(); 1552657Ssaidi@eecs.umich.edu 1564433Ssaidi@eecs.umich.edu //put it on the list to send 1574435Ssaidi@eecs.umich.edu Tick readyTime = curTick + nackDelay; 1584433Ssaidi@eecs.umich.edu PacketBuffer *buf = new PacketBuffer(pkt, readyTime, true); 1594435Ssaidi@eecs.umich.edu 1604435Ssaidi@eecs.umich.edu // nothing on the list, add it and we're done 1614433Ssaidi@eecs.umich.edu if (sendQueue.empty()) { 1624435Ssaidi@eecs.umich.edu assert(!sendEvent.scheduled()); 1634433Ssaidi@eecs.umich.edu sendEvent.schedule(readyTime); 1644435Ssaidi@eecs.umich.edu sendQueue.push_back(buf); 1654435Ssaidi@eecs.umich.edu return; 1664433Ssaidi@eecs.umich.edu } 1674435Ssaidi@eecs.umich.edu 1684435Ssaidi@eecs.umich.edu assert(sendEvent.scheduled() || inRetry); 1694435Ssaidi@eecs.umich.edu 1704435Ssaidi@eecs.umich.edu // does it go at the end? 1714435Ssaidi@eecs.umich.edu if (readyTime >= sendQueue.back()->ready) { 1724435Ssaidi@eecs.umich.edu sendQueue.push_back(buf); 1734435Ssaidi@eecs.umich.edu return; 1744435Ssaidi@eecs.umich.edu } 1754435Ssaidi@eecs.umich.edu 1764435Ssaidi@eecs.umich.edu // ok, somewhere in the middle, fun 1774435Ssaidi@eecs.umich.edu std::list<PacketBuffer*>::iterator i = sendQueue.begin(); 1784435Ssaidi@eecs.umich.edu std::list<PacketBuffer*>::iterator end = sendQueue.end(); 1794435Ssaidi@eecs.umich.edu std::list<PacketBuffer*>::iterator begin = sendQueue.begin(); 1804435Ssaidi@eecs.umich.edu bool done = false; 1814435Ssaidi@eecs.umich.edu 1824435Ssaidi@eecs.umich.edu while (i != end && !done) { 1834435Ssaidi@eecs.umich.edu if (readyTime < (*i)->ready) { 1844435Ssaidi@eecs.umich.edu if (i == begin) 1854435Ssaidi@eecs.umich.edu sendEvent.reschedule(readyTime); 1864435Ssaidi@eecs.umich.edu sendQueue.insert(i,buf); 1874435Ssaidi@eecs.umich.edu done = true; 1884435Ssaidi@eecs.umich.edu } 1894435Ssaidi@eecs.umich.edu i++; 1904435Ssaidi@eecs.umich.edu } 1914435Ssaidi@eecs.umich.edu assert(done); 1924433Ssaidi@eecs.umich.edu} 1934433Ssaidi@eecs.umich.edu 1944433Ssaidi@eecs.umich.edu 1954433Ssaidi@eecs.umich.eduvoid 1963349Sbinkertn@umich.eduBridge::BridgePort::queueForSendTiming(PacketPtr pkt) 1972657Ssaidi@eecs.umich.edu{ 1984986Ssaidi@eecs.umich.edu if (pkt->isResponse()) { 1992643Sstever@eecs.umich.edu // This is a response for a request we forwarded earlier. The 2002643Sstever@eecs.umich.edu // corresponding PacketBuffer should be stored in the packet's 2012643Sstever@eecs.umich.edu // senderState field. 2024986Ssaidi@eecs.umich.edu 2032643Sstever@eecs.umich.edu PacketBuffer *buf = dynamic_cast<PacketBuffer*>(pkt->senderState); 2042643Sstever@eecs.umich.edu assert(buf != NULL); 2052643Sstever@eecs.umich.edu // set up new packet dest & senderState based on values saved 2062643Sstever@eecs.umich.edu // from original request 2072643Sstever@eecs.umich.edu buf->fixResponse(pkt); 2084433Ssaidi@eecs.umich.edu 2094739Sstever@eecs.umich.edu DPRINTF(BusBridge, "response, new dest %d\n", pkt->getDest()); 2102643Sstever@eecs.umich.edu delete buf; 2112643Sstever@eecs.umich.edu } 2122643Sstever@eecs.umich.edu 2134450Ssaidi@eecs.umich.edu 2144986Ssaidi@eecs.umich.edu if (pkt->isRequest()) { 2154450Ssaidi@eecs.umich.edu ++queuedRequests; 2164450Ssaidi@eecs.umich.edu } 2174450Ssaidi@eecs.umich.edu 2184450Ssaidi@eecs.umich.edu 2194450Ssaidi@eecs.umich.edu 2202643Sstever@eecs.umich.edu Tick readyTime = curTick + delay; 2212643Sstever@eecs.umich.edu PacketBuffer *buf = new PacketBuffer(pkt, readyTime); 2222643Sstever@eecs.umich.edu 2232643Sstever@eecs.umich.edu // If we're about to put this packet at the head of the queue, we 2242643Sstever@eecs.umich.edu // need to schedule an event to do the transmit. Otherwise there 2252643Sstever@eecs.umich.edu // should already be an event scheduled for sending the head 2262643Sstever@eecs.umich.edu // packet. 2272643Sstever@eecs.umich.edu if (sendQueue.empty()) { 2282643Sstever@eecs.umich.edu sendEvent.schedule(readyTime); 2292568SN/A } 2302643Sstever@eecs.umich.edu sendQueue.push_back(buf); 2312568SN/A} 2322568SN/A 2332568SN/Avoid 2342643Sstever@eecs.umich.eduBridge::BridgePort::trySend() 2352568SN/A{ 2362643Sstever@eecs.umich.edu assert(!sendQueue.empty()); 2372568SN/A 2382643Sstever@eecs.umich.edu PacketBuffer *buf = sendQueue.front(); 2392643Sstever@eecs.umich.edu 2402643Sstever@eecs.umich.edu assert(buf->ready <= curTick); 2412643Sstever@eecs.umich.edu 2423349Sbinkertn@umich.edu PacketPtr pkt = buf->pkt; 2432643Sstever@eecs.umich.edu 2442643Sstever@eecs.umich.edu DPRINTF(BusBridge, "trySend: origSrc %d dest %d addr 0x%x\n", 2452643Sstever@eecs.umich.edu buf->origSrc, pkt->getDest(), pkt->getAddr()); 2462643Sstever@eecs.umich.edu 2474450Ssaidi@eecs.umich.edu bool wasReq = pkt->isRequest(); 2484986Ssaidi@eecs.umich.edu bool was_nacked_here = buf->nackedHere; 2494986Ssaidi@eecs.umich.edu 2504986Ssaidi@eecs.umich.edu // If the send was successful, make sure sender state was set to NULL 2514986Ssaidi@eecs.umich.edu // otherwise we could get a NACK back of a packet that didn't expect a 2524986Ssaidi@eecs.umich.edu // response and we would try to use freed memory. 2534986Ssaidi@eecs.umich.edu 2544986Ssaidi@eecs.umich.edu Packet::SenderState *old_sender_state = pkt->senderState; 2554986Ssaidi@eecs.umich.edu if (pkt->isRequest() && !buf->expectResponse) 2564986Ssaidi@eecs.umich.edu pkt->senderState = NULL; 2574432Ssaidi@eecs.umich.edu 2582643Sstever@eecs.umich.edu if (sendTiming(pkt)) { 2592643Sstever@eecs.umich.edu // send successful 2602643Sstever@eecs.umich.edu sendQueue.pop_front(); 2612643Sstever@eecs.umich.edu buf->pkt = NULL; // we no longer own packet, so it's not safe to look at it 2622657Ssaidi@eecs.umich.edu 2632657Ssaidi@eecs.umich.edu if (buf->expectResponse) { 2644433Ssaidi@eecs.umich.edu // Must wait for response 2652657Ssaidi@eecs.umich.edu DPRINTF(BusBridge, " successful: awaiting response (%d)\n", 2662657Ssaidi@eecs.umich.edu outstandingResponses); 2672657Ssaidi@eecs.umich.edu } else { 2682657Ssaidi@eecs.umich.edu // no response expected... deallocate packet buffer now. 2692657Ssaidi@eecs.umich.edu DPRINTF(BusBridge, " successful: no response expected\n"); 2702657Ssaidi@eecs.umich.edu delete buf; 2712657Ssaidi@eecs.umich.edu } 2722657Ssaidi@eecs.umich.edu 2734986Ssaidi@eecs.umich.edu if (wasReq) 2744986Ssaidi@eecs.umich.edu --queuedRequests; 2754986Ssaidi@eecs.umich.edu else if (!was_nacked_here) 2764986Ssaidi@eecs.umich.edu --outstandingResponses; 2774433Ssaidi@eecs.umich.edu 2782657Ssaidi@eecs.umich.edu // If there are more packets to send, schedule event to try again. 2792657Ssaidi@eecs.umich.edu if (!sendQueue.empty()) { 2802657Ssaidi@eecs.umich.edu buf = sendQueue.front(); 2814433Ssaidi@eecs.umich.edu DPRINTF(BusBridge, "Scheduling next send\n"); 2822657Ssaidi@eecs.umich.edu sendEvent.schedule(std::max(buf->ready, curTick + 1)); 2832657Ssaidi@eecs.umich.edu } 2842643Sstever@eecs.umich.edu } else { 2852643Sstever@eecs.umich.edu DPRINTF(BusBridge, " unsuccessful\n"); 2864986Ssaidi@eecs.umich.edu pkt->senderState = old_sender_state; 2874435Ssaidi@eecs.umich.edu inRetry = true; 2882643Sstever@eecs.umich.edu } 2894986Ssaidi@eecs.umich.edu 2904433Ssaidi@eecs.umich.edu DPRINTF(BusBridge, "trySend: queue size: %d outreq: %d outstanding resp: %d\n", 2914433Ssaidi@eecs.umich.edu sendQueue.size(), queuedRequests, outstandingResponses); 2922568SN/A} 2932568SN/A 2942568SN/A 2952657Ssaidi@eecs.umich.eduvoid 2962568SN/ABridge::BridgePort::recvRetry() 2972568SN/A{ 2984435Ssaidi@eecs.umich.edu inRetry = false; 2994435Ssaidi@eecs.umich.edu Tick nextReady = sendQueue.front()->ready; 3004435Ssaidi@eecs.umich.edu if (nextReady <= curTick) 3014435Ssaidi@eecs.umich.edu trySend(); 3024435Ssaidi@eecs.umich.edu else 3034435Ssaidi@eecs.umich.edu sendEvent.schedule(nextReady); 3042568SN/A} 3052568SN/A 3062643Sstever@eecs.umich.edu/** Function called by the port when the bus is receiving a Atomic 3072568SN/A * transaction.*/ 3082568SN/ATick 3093349Sbinkertn@umich.eduBridge::BridgePort::recvAtomic(PacketPtr pkt) 3102568SN/A{ 3114454Ssaidi@eecs.umich.edu return delay + otherPort->sendAtomic(pkt); 3122568SN/A} 3132568SN/A 3142643Sstever@eecs.umich.edu/** Function called by the port when the bus is receiving a Functional 3152568SN/A * transaction.*/ 3162568SN/Avoid 3173349Sbinkertn@umich.eduBridge::BridgePort::recvFunctional(PacketPtr pkt) 3182568SN/A{ 3192643Sstever@eecs.umich.edu std::list<PacketBuffer*>::iterator i; 3202568SN/A 3212643Sstever@eecs.umich.edu for (i = sendQueue.begin(); i != sendQueue.end(); ++i) { 3224626Sstever@eecs.umich.edu if (pkt->checkFunctional((*i)->pkt)) 3234626Sstever@eecs.umich.edu return; 3242568SN/A } 3252568SN/A 3264626Sstever@eecs.umich.edu // fall through if pkt still not satisfied 3274626Sstever@eecs.umich.edu otherPort->sendFunctional(pkt); 3282568SN/A} 3292568SN/A 3302643Sstever@eecs.umich.edu/** Function called by the port when the bus is receiving a status change.*/ 3312568SN/Avoid 3322643Sstever@eecs.umich.eduBridge::BridgePort::recvStatusChange(Port::Status status) 3332568SN/A{ 3342643Sstever@eecs.umich.edu otherPort->sendStatusChange(status); 3352568SN/A} 3362568SN/A 3372568SN/Avoid 3382643Sstever@eecs.umich.eduBridge::BridgePort::getDeviceAddressRanges(AddrRangeList &resp, 3394475Sstever@eecs.umich.edu bool &snoop) 3402568SN/A{ 3412643Sstever@eecs.umich.edu otherPort->getPeerAddressRanges(resp, snoop); 3424965Ssaidi@eecs.umich.edu FilterRangeList(filterRanges, resp); 3434877Sstever@eecs.umich.edu // we don't allow snooping across bridges 3444877Sstever@eecs.umich.edu snoop = false; 3452568SN/A} 3462568SN/A 3474762Snate@binkert.orgBridge * 3484762Snate@binkert.orgBridgeParams::create() 3492568SN/A{ 3504762Snate@binkert.org return new Bridge(this); 3512568SN/A} 352