bridge.cc revision 8232
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" 428232Snate@binkert.org#include "debug/BusBridge.hh" 432568SN/A#include "mem/bridge.hh" 444762Snate@binkert.org#include "params/Bridge.hh" 452568SN/A 462643Sstever@eecs.umich.eduBridge::BridgePort::BridgePort(const std::string &_name, 472643Sstever@eecs.umich.edu Bridge *_bridge, BridgePort *_otherPort, 484435Ssaidi@eecs.umich.edu int _delay, int _nack_delay, int _req_limit, 494965Ssaidi@eecs.umich.edu int _resp_limit, 504965Ssaidi@eecs.umich.edu std::vector<Range<Addr> > filter_ranges) 515606Snate@binkert.org : Port(_name, _bridge), bridge(_bridge), otherPort(_otherPort), 524965Ssaidi@eecs.umich.edu delay(_delay), nackDelay(_nack_delay), filterRanges(filter_ranges), 534435Ssaidi@eecs.umich.edu outstandingResponses(0), queuedRequests(0), inRetry(false), 544435Ssaidi@eecs.umich.edu reqQueueLimit(_req_limit), respQueueLimit(_resp_limit), sendEvent(this) 552643Sstever@eecs.umich.edu{ 562643Sstever@eecs.umich.edu} 572643Sstever@eecs.umich.edu 584435Ssaidi@eecs.umich.eduBridge::Bridge(Params *p) 595034Smilesck@eecs.umich.edu : MemObject(p), 604435Ssaidi@eecs.umich.edu portA(p->name + "-portA", this, &portB, p->delay, p->nack_delay, 614965Ssaidi@eecs.umich.edu p->req_size_a, p->resp_size_a, p->filter_ranges_a), 624435Ssaidi@eecs.umich.edu portB(p->name + "-portB", this, &portA, p->delay, p->nack_delay, 634965Ssaidi@eecs.umich.edu p->req_size_b, p->resp_size_b, p->filter_ranges_b), 644435Ssaidi@eecs.umich.edu ackWrites(p->write_ack), _params(p) 652643Sstever@eecs.umich.edu{ 664432Ssaidi@eecs.umich.edu if (ackWrites) 674432Ssaidi@eecs.umich.edu panic("No support for acknowledging writes\n"); 682643Sstever@eecs.umich.edu} 692643Sstever@eecs.umich.edu 702643Sstever@eecs.umich.eduPort * 712738Sstever@eecs.umich.eduBridge::getPort(const std::string &if_name, int idx) 722643Sstever@eecs.umich.edu{ 732643Sstever@eecs.umich.edu BridgePort *port; 742643Sstever@eecs.umich.edu 752643Sstever@eecs.umich.edu if (if_name == "side_a") 762643Sstever@eecs.umich.edu port = &portA; 772643Sstever@eecs.umich.edu else if (if_name == "side_b") 782643Sstever@eecs.umich.edu port = &portB; 792643Sstever@eecs.umich.edu else 802643Sstever@eecs.umich.edu return NULL; 812643Sstever@eecs.umich.edu 825283Sgblack@eecs.umich.edu if (port->getPeer() != NULL && !port->getPeer()->isDefaultPort()) 835283Sgblack@eecs.umich.edu panic("bridge side %s already connected to %s.", 845283Sgblack@eecs.umich.edu if_name, port->getPeer()->name()); 852643Sstever@eecs.umich.edu return port; 862643Sstever@eecs.umich.edu} 872643Sstever@eecs.umich.edu 882643Sstever@eecs.umich.edu 892568SN/Avoid 902568SN/ABridge::init() 912568SN/A{ 922568SN/A // Make sure that both sides are connected to. 935476Snate@binkert.org if (!portA.isConnected() || !portB.isConnected()) 944432Ssaidi@eecs.umich.edu fatal("Both ports of bus bridge are not connected to a bus.\n"); 954432Ssaidi@eecs.umich.edu 964432Ssaidi@eecs.umich.edu if (portA.peerBlockSize() != portB.peerBlockSize()) 976764SBrad.Beckmann@amd.com fatal("port A size %d, port B size %d \n " \ 986764SBrad.Beckmann@amd.com "Busses don't have the same block size... Not supported.\n", 996764SBrad.Beckmann@amd.com portA.peerBlockSize(), portB.peerBlockSize()); 1002568SN/A} 1012568SN/A 1024433Ssaidi@eecs.umich.edubool 1034435Ssaidi@eecs.umich.eduBridge::BridgePort::respQueueFull() 1044433Ssaidi@eecs.umich.edu{ 1054435Ssaidi@eecs.umich.edu assert(outstandingResponses >= 0 && outstandingResponses <= respQueueLimit); 1064435Ssaidi@eecs.umich.edu return outstandingResponses >= respQueueLimit; 1074435Ssaidi@eecs.umich.edu} 1084435Ssaidi@eecs.umich.edu 1094435Ssaidi@eecs.umich.edubool 1104435Ssaidi@eecs.umich.eduBridge::BridgePort::reqQueueFull() 1114435Ssaidi@eecs.umich.edu{ 1124435Ssaidi@eecs.umich.edu assert(queuedRequests >= 0 && queuedRequests <= reqQueueLimit); 1134435Ssaidi@eecs.umich.edu return queuedRequests >= reqQueueLimit; 1144433Ssaidi@eecs.umich.edu} 1152568SN/A 1162643Sstever@eecs.umich.edu/** Function called by the port when the bus is receiving a Timing 1172568SN/A * transaction.*/ 1182568SN/Abool 1193349Sbinkertn@umich.eduBridge::BridgePort::recvTiming(PacketPtr pkt) 1202568SN/A{ 1214433Ssaidi@eecs.umich.edu DPRINTF(BusBridge, "recvTiming: src %d dest %d addr 0x%x\n", 1223662Srdreslin@umich.edu pkt->getSrc(), pkt->getDest(), pkt->getAddr()); 1232643Sstever@eecs.umich.edu 1244450Ssaidi@eecs.umich.edu DPRINTF(BusBridge, "Local queue size: %d outreq: %d outresp: %d\n", 1254450Ssaidi@eecs.umich.edu sendQueue.size(), queuedRequests, outstandingResponses); 1264986Ssaidi@eecs.umich.edu DPRINTF(BusBridge, "Remote queue size: %d outreq: %d outresp: %d\n", 1274450Ssaidi@eecs.umich.edu otherPort->sendQueue.size(), otherPort->queuedRequests, 1284450Ssaidi@eecs.umich.edu otherPort->outstandingResponses); 1294450Ssaidi@eecs.umich.edu 1304986Ssaidi@eecs.umich.edu if (pkt->isRequest() && otherPort->reqQueueFull()) { 1314433Ssaidi@eecs.umich.edu DPRINTF(BusBridge, "Remote queue full, nacking\n"); 1324433Ssaidi@eecs.umich.edu nackRequest(pkt); 1334433Ssaidi@eecs.umich.edu return true; 1343662Srdreslin@umich.edu } 1354433Ssaidi@eecs.umich.edu 1365562Snate@binkert.org if (pkt->needsResponse()) { 1374435Ssaidi@eecs.umich.edu if (respQueueFull()) { 1384433Ssaidi@eecs.umich.edu DPRINTF(BusBridge, "Local queue full, no space for response, nacking\n"); 1394433Ssaidi@eecs.umich.edu DPRINTF(BusBridge, "queue size: %d outreq: %d outstanding resp: %d\n", 1404433Ssaidi@eecs.umich.edu sendQueue.size(), queuedRequests, outstandingResponses); 1414433Ssaidi@eecs.umich.edu nackRequest(pkt); 1424433Ssaidi@eecs.umich.edu return true; 1434433Ssaidi@eecs.umich.edu } else { 1444433Ssaidi@eecs.umich.edu DPRINTF(BusBridge, "Request Needs response, reserving space\n"); 1454433Ssaidi@eecs.umich.edu ++outstandingResponses; 1464433Ssaidi@eecs.umich.edu } 1475562Snate@binkert.org } 1484433Ssaidi@eecs.umich.edu 1494433Ssaidi@eecs.umich.edu otherPort->queueForSendTiming(pkt); 1504433Ssaidi@eecs.umich.edu 1514433Ssaidi@eecs.umich.edu return true; 1522657Ssaidi@eecs.umich.edu} 1532657Ssaidi@eecs.umich.edu 1544433Ssaidi@eecs.umich.eduvoid 1554433Ssaidi@eecs.umich.eduBridge::BridgePort::nackRequest(PacketPtr pkt) 1564433Ssaidi@eecs.umich.edu{ 1574433Ssaidi@eecs.umich.edu // Nack the packet 1584986Ssaidi@eecs.umich.edu pkt->makeTimingResponse(); 1594870Sstever@eecs.umich.edu pkt->setNacked(); 1602657Ssaidi@eecs.umich.edu 1614433Ssaidi@eecs.umich.edu //put it on the list to send 1627823Ssteve.reinhardt@amd.com Tick readyTime = curTick() + nackDelay; 1634433Ssaidi@eecs.umich.edu PacketBuffer *buf = new PacketBuffer(pkt, readyTime, true); 1644435Ssaidi@eecs.umich.edu 1654435Ssaidi@eecs.umich.edu // nothing on the list, add it and we're done 1664433Ssaidi@eecs.umich.edu if (sendQueue.empty()) { 1674435Ssaidi@eecs.umich.edu assert(!sendEvent.scheduled()); 1685606Snate@binkert.org schedule(sendEvent, readyTime); 1694435Ssaidi@eecs.umich.edu sendQueue.push_back(buf); 1704435Ssaidi@eecs.umich.edu return; 1714433Ssaidi@eecs.umich.edu } 1724435Ssaidi@eecs.umich.edu 1734435Ssaidi@eecs.umich.edu assert(sendEvent.scheduled() || inRetry); 1744435Ssaidi@eecs.umich.edu 1754435Ssaidi@eecs.umich.edu // does it go at the end? 1764435Ssaidi@eecs.umich.edu if (readyTime >= sendQueue.back()->ready) { 1774435Ssaidi@eecs.umich.edu sendQueue.push_back(buf); 1784435Ssaidi@eecs.umich.edu return; 1794435Ssaidi@eecs.umich.edu } 1804435Ssaidi@eecs.umich.edu 1814435Ssaidi@eecs.umich.edu // ok, somewhere in the middle, fun 1824435Ssaidi@eecs.umich.edu std::list<PacketBuffer*>::iterator i = sendQueue.begin(); 1834435Ssaidi@eecs.umich.edu std::list<PacketBuffer*>::iterator end = sendQueue.end(); 1844435Ssaidi@eecs.umich.edu std::list<PacketBuffer*>::iterator begin = sendQueue.begin(); 1854435Ssaidi@eecs.umich.edu bool done = false; 1864435Ssaidi@eecs.umich.edu 1874435Ssaidi@eecs.umich.edu while (i != end && !done) { 1884435Ssaidi@eecs.umich.edu if (readyTime < (*i)->ready) { 1894435Ssaidi@eecs.umich.edu if (i == begin) 1905606Snate@binkert.org reschedule(sendEvent, readyTime); 1914435Ssaidi@eecs.umich.edu sendQueue.insert(i,buf); 1924435Ssaidi@eecs.umich.edu done = true; 1934435Ssaidi@eecs.umich.edu } 1944435Ssaidi@eecs.umich.edu i++; 1954435Ssaidi@eecs.umich.edu } 1964435Ssaidi@eecs.umich.edu assert(done); 1974433Ssaidi@eecs.umich.edu} 1984433Ssaidi@eecs.umich.edu 1994433Ssaidi@eecs.umich.edu 2004433Ssaidi@eecs.umich.eduvoid 2013349Sbinkertn@umich.eduBridge::BridgePort::queueForSendTiming(PacketPtr pkt) 2022657Ssaidi@eecs.umich.edu{ 2034986Ssaidi@eecs.umich.edu if (pkt->isResponse()) { 2042643Sstever@eecs.umich.edu // This is a response for a request we forwarded earlier. The 2052643Sstever@eecs.umich.edu // corresponding PacketBuffer should be stored in the packet's 2062643Sstever@eecs.umich.edu // senderState field. 2074986Ssaidi@eecs.umich.edu 2082643Sstever@eecs.umich.edu PacketBuffer *buf = dynamic_cast<PacketBuffer*>(pkt->senderState); 2092643Sstever@eecs.umich.edu assert(buf != NULL); 2102643Sstever@eecs.umich.edu // set up new packet dest & senderState based on values saved 2112643Sstever@eecs.umich.edu // from original request 2122643Sstever@eecs.umich.edu buf->fixResponse(pkt); 2134433Ssaidi@eecs.umich.edu 2144739Sstever@eecs.umich.edu DPRINTF(BusBridge, "response, new dest %d\n", pkt->getDest()); 2152643Sstever@eecs.umich.edu delete buf; 2162643Sstever@eecs.umich.edu } 2172643Sstever@eecs.umich.edu 2184450Ssaidi@eecs.umich.edu 2194986Ssaidi@eecs.umich.edu if (pkt->isRequest()) { 2204450Ssaidi@eecs.umich.edu ++queuedRequests; 2214450Ssaidi@eecs.umich.edu } 2224450Ssaidi@eecs.umich.edu 2234450Ssaidi@eecs.umich.edu 2244450Ssaidi@eecs.umich.edu 2257823Ssteve.reinhardt@amd.com Tick readyTime = curTick() + delay; 2262643Sstever@eecs.umich.edu PacketBuffer *buf = new PacketBuffer(pkt, readyTime); 2272643Sstever@eecs.umich.edu 2282643Sstever@eecs.umich.edu // If we're about to put this packet at the head of the queue, we 2292643Sstever@eecs.umich.edu // need to schedule an event to do the transmit. Otherwise there 2302643Sstever@eecs.umich.edu // should already be an event scheduled for sending the head 2312643Sstever@eecs.umich.edu // packet. 2322643Sstever@eecs.umich.edu if (sendQueue.empty()) { 2335606Snate@binkert.org schedule(sendEvent, readyTime); 2342568SN/A } 2352643Sstever@eecs.umich.edu sendQueue.push_back(buf); 2362568SN/A} 2372568SN/A 2382568SN/Avoid 2392643Sstever@eecs.umich.eduBridge::BridgePort::trySend() 2402568SN/A{ 2412643Sstever@eecs.umich.edu assert(!sendQueue.empty()); 2422568SN/A 2432643Sstever@eecs.umich.edu PacketBuffer *buf = sendQueue.front(); 2442643Sstever@eecs.umich.edu 2457823Ssteve.reinhardt@amd.com assert(buf->ready <= curTick()); 2462643Sstever@eecs.umich.edu 2473349Sbinkertn@umich.edu PacketPtr pkt = buf->pkt; 2482643Sstever@eecs.umich.edu 2492643Sstever@eecs.umich.edu DPRINTF(BusBridge, "trySend: origSrc %d dest %d addr 0x%x\n", 2502643Sstever@eecs.umich.edu buf->origSrc, pkt->getDest(), pkt->getAddr()); 2512643Sstever@eecs.umich.edu 2524450Ssaidi@eecs.umich.edu bool wasReq = pkt->isRequest(); 2534986Ssaidi@eecs.umich.edu bool was_nacked_here = buf->nackedHere; 2544986Ssaidi@eecs.umich.edu 2554986Ssaidi@eecs.umich.edu // If the send was successful, make sure sender state was set to NULL 2564986Ssaidi@eecs.umich.edu // otherwise we could get a NACK back of a packet that didn't expect a 2574986Ssaidi@eecs.umich.edu // response and we would try to use freed memory. 2584986Ssaidi@eecs.umich.edu 2594986Ssaidi@eecs.umich.edu Packet::SenderState *old_sender_state = pkt->senderState; 2604986Ssaidi@eecs.umich.edu if (pkt->isRequest() && !buf->expectResponse) 2614986Ssaidi@eecs.umich.edu pkt->senderState = NULL; 2624432Ssaidi@eecs.umich.edu 2632643Sstever@eecs.umich.edu if (sendTiming(pkt)) { 2642643Sstever@eecs.umich.edu // send successful 2652643Sstever@eecs.umich.edu sendQueue.pop_front(); 2662643Sstever@eecs.umich.edu buf->pkt = NULL; // we no longer own packet, so it's not safe to look at it 2672657Ssaidi@eecs.umich.edu 2682657Ssaidi@eecs.umich.edu if (buf->expectResponse) { 2694433Ssaidi@eecs.umich.edu // Must wait for response 2702657Ssaidi@eecs.umich.edu DPRINTF(BusBridge, " successful: awaiting response (%d)\n", 2712657Ssaidi@eecs.umich.edu outstandingResponses); 2722657Ssaidi@eecs.umich.edu } else { 2732657Ssaidi@eecs.umich.edu // no response expected... deallocate packet buffer now. 2742657Ssaidi@eecs.umich.edu DPRINTF(BusBridge, " successful: no response expected\n"); 2752657Ssaidi@eecs.umich.edu delete buf; 2762657Ssaidi@eecs.umich.edu } 2772657Ssaidi@eecs.umich.edu 2784986Ssaidi@eecs.umich.edu if (wasReq) 2794986Ssaidi@eecs.umich.edu --queuedRequests; 2804986Ssaidi@eecs.umich.edu else if (!was_nacked_here) 2814986Ssaidi@eecs.umich.edu --outstandingResponses; 2824433Ssaidi@eecs.umich.edu 2832657Ssaidi@eecs.umich.edu // If there are more packets to send, schedule event to try again. 2842657Ssaidi@eecs.umich.edu if (!sendQueue.empty()) { 2852657Ssaidi@eecs.umich.edu buf = sendQueue.front(); 2864433Ssaidi@eecs.umich.edu DPRINTF(BusBridge, "Scheduling next send\n"); 2877823Ssteve.reinhardt@amd.com schedule(sendEvent, std::max(buf->ready, curTick() + 1)); 2882657Ssaidi@eecs.umich.edu } 2892643Sstever@eecs.umich.edu } else { 2902643Sstever@eecs.umich.edu DPRINTF(BusBridge, " unsuccessful\n"); 2914986Ssaidi@eecs.umich.edu pkt->senderState = old_sender_state; 2924435Ssaidi@eecs.umich.edu inRetry = true; 2932643Sstever@eecs.umich.edu } 2944986Ssaidi@eecs.umich.edu 2954433Ssaidi@eecs.umich.edu DPRINTF(BusBridge, "trySend: queue size: %d outreq: %d outstanding resp: %d\n", 2964433Ssaidi@eecs.umich.edu sendQueue.size(), queuedRequests, outstandingResponses); 2972568SN/A} 2982568SN/A 2992568SN/A 3002657Ssaidi@eecs.umich.eduvoid 3012568SN/ABridge::BridgePort::recvRetry() 3022568SN/A{ 3034435Ssaidi@eecs.umich.edu inRetry = false; 3044435Ssaidi@eecs.umich.edu Tick nextReady = sendQueue.front()->ready; 3057823Ssteve.reinhardt@amd.com if (nextReady <= curTick()) 3064435Ssaidi@eecs.umich.edu trySend(); 3074435Ssaidi@eecs.umich.edu else 3085606Snate@binkert.org schedule(sendEvent, nextReady); 3092568SN/A} 3102568SN/A 3112643Sstever@eecs.umich.edu/** Function called by the port when the bus is receiving a Atomic 3122568SN/A * transaction.*/ 3132568SN/ATick 3143349Sbinkertn@umich.eduBridge::BridgePort::recvAtomic(PacketPtr pkt) 3152568SN/A{ 3164454Ssaidi@eecs.umich.edu return delay + otherPort->sendAtomic(pkt); 3172568SN/A} 3182568SN/A 3192643Sstever@eecs.umich.edu/** Function called by the port when the bus is receiving a Functional 3202568SN/A * transaction.*/ 3212568SN/Avoid 3223349Sbinkertn@umich.eduBridge::BridgePort::recvFunctional(PacketPtr pkt) 3232568SN/A{ 3242643Sstever@eecs.umich.edu std::list<PacketBuffer*>::iterator i; 3252568SN/A 3265314Sstever@gmail.com pkt->pushLabel(name()); 3275314Sstever@gmail.com 3282643Sstever@eecs.umich.edu for (i = sendQueue.begin(); i != sendQueue.end(); ++i) { 3297668Ssteve.reinhardt@amd.com if (pkt->checkFunctional((*i)->pkt)) { 3307668Ssteve.reinhardt@amd.com pkt->makeResponse(); 3314626Sstever@eecs.umich.edu return; 3327668Ssteve.reinhardt@amd.com } 3332568SN/A } 3342568SN/A 3355314Sstever@gmail.com pkt->popLabel(); 3365314Sstever@gmail.com 3374626Sstever@eecs.umich.edu // fall through if pkt still not satisfied 3384626Sstever@eecs.umich.edu otherPort->sendFunctional(pkt); 3392568SN/A} 3402568SN/A 3412643Sstever@eecs.umich.edu/** Function called by the port when the bus is receiving a status change.*/ 3422568SN/Avoid 3432643Sstever@eecs.umich.eduBridge::BridgePort::recvStatusChange(Port::Status status) 3442568SN/A{ 3452643Sstever@eecs.umich.edu otherPort->sendStatusChange(status); 3462568SN/A} 3472568SN/A 3482568SN/Avoid 3492643Sstever@eecs.umich.eduBridge::BridgePort::getDeviceAddressRanges(AddrRangeList &resp, 3504475Sstever@eecs.umich.edu bool &snoop) 3512568SN/A{ 3522643Sstever@eecs.umich.edu otherPort->getPeerAddressRanges(resp, snoop); 3534965Ssaidi@eecs.umich.edu FilterRangeList(filterRanges, resp); 3544877Sstever@eecs.umich.edu // we don't allow snooping across bridges 3554877Sstever@eecs.umich.edu snoop = false; 3562568SN/A} 3572568SN/A 3584762Snate@binkert.orgBridge * 3594762Snate@binkert.orgBridgeParams::create() 3602568SN/A{ 3614762Snate@binkert.org return new Bridge(this); 3622568SN/A} 363