bridge.cc revision 4432
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 402568SN/A#include "base/trace.hh" 412568SN/A#include "mem/bridge.hh" 422568SN/A#include "sim/builder.hh" 432568SN/A 442643Sstever@eecs.umich.eduBridge::BridgePort::BridgePort(const std::string &_name, 452643Sstever@eecs.umich.edu Bridge *_bridge, BridgePort *_otherPort, 464432Ssaidi@eecs.umich.edu int _delay, int _queueLimit, 474432Ssaidi@eecs.umich.edu bool fix_partial_write) 482643Sstever@eecs.umich.edu : Port(_name), bridge(_bridge), otherPort(_otherPort), 494432Ssaidi@eecs.umich.edu delay(_delay), fixPartialWrite(fix_partial_write), 504432Ssaidi@eecs.umich.edu outstandingResponses(0), queueLimit(_queueLimit), sendEvent(this) 512643Sstever@eecs.umich.edu{ 522643Sstever@eecs.umich.edu} 532643Sstever@eecs.umich.edu 542643Sstever@eecs.umich.eduBridge::Bridge(const std::string &n, int qsa, int qsb, 554432Ssaidi@eecs.umich.edu Tick _delay, int write_ack, bool fix_partial_write_a, 564432Ssaidi@eecs.umich.edu bool fix_partial_write_b) 572643Sstever@eecs.umich.edu : MemObject(n), 584432Ssaidi@eecs.umich.edu portA(n + "-portA", this, &portB, _delay, qsa, fix_partial_write_a), 594432Ssaidi@eecs.umich.edu portB(n + "-portB", this, &portA, _delay, qsa, fix_partial_write_b), 602643Sstever@eecs.umich.edu ackWrites(write_ack) 612643Sstever@eecs.umich.edu{ 624432Ssaidi@eecs.umich.edu if (ackWrites) 634432Ssaidi@eecs.umich.edu panic("No support for acknowledging writes\n"); 642643Sstever@eecs.umich.edu} 652643Sstever@eecs.umich.edu 662643Sstever@eecs.umich.eduPort * 672738Sstever@eecs.umich.eduBridge::getPort(const std::string &if_name, int idx) 682643Sstever@eecs.umich.edu{ 692643Sstever@eecs.umich.edu BridgePort *port; 702643Sstever@eecs.umich.edu 712643Sstever@eecs.umich.edu if (if_name == "side_a") 722643Sstever@eecs.umich.edu port = &portA; 732643Sstever@eecs.umich.edu else if (if_name == "side_b") 742643Sstever@eecs.umich.edu port = &portB; 752643Sstever@eecs.umich.edu else 762643Sstever@eecs.umich.edu return NULL; 772643Sstever@eecs.umich.edu 782643Sstever@eecs.umich.edu if (port->getPeer() != NULL) 792643Sstever@eecs.umich.edu panic("bridge side %s already connected to.", if_name); 802643Sstever@eecs.umich.edu return port; 812643Sstever@eecs.umich.edu} 822643Sstever@eecs.umich.edu 832643Sstever@eecs.umich.edu 842568SN/Avoid 852568SN/ABridge::init() 862568SN/A{ 872568SN/A // Make sure that both sides are connected to. 882643Sstever@eecs.umich.edu if (portA.getPeer() == NULL || portB.getPeer() == NULL) 894432Ssaidi@eecs.umich.edu fatal("Both ports of bus bridge are not connected to a bus.\n"); 904432Ssaidi@eecs.umich.edu 914432Ssaidi@eecs.umich.edu if (portA.peerBlockSize() != portB.peerBlockSize()) 924432Ssaidi@eecs.umich.edu fatal("Busses don't have the same block size... Not supported.\n"); 932568SN/A} 942568SN/A 952568SN/A 962643Sstever@eecs.umich.edu/** Function called by the port when the bus is receiving a Timing 972568SN/A * transaction.*/ 982568SN/Abool 993349Sbinkertn@umich.eduBridge::BridgePort::recvTiming(PacketPtr pkt) 1002568SN/A{ 1013662Srdreslin@umich.edu if (pkt->flags & SNOOP_COMMIT) { 1023662Srdreslin@umich.edu DPRINTF(BusBridge, "recvTiming: src %d dest %d addr 0x%x\n", 1033662Srdreslin@umich.edu pkt->getSrc(), pkt->getDest(), pkt->getAddr()); 1042643Sstever@eecs.umich.edu 1053662Srdreslin@umich.edu return otherPort->queueForSendTiming(pkt); 1063662Srdreslin@umich.edu } 1073662Srdreslin@umich.edu else { 1083662Srdreslin@umich.edu // Else it's just a snoop, properly return if we are blocking 1093662Srdreslin@umich.edu return !queueFull(); 1103662Srdreslin@umich.edu } 1112657Ssaidi@eecs.umich.edu} 1122657Ssaidi@eecs.umich.edu 1132657Ssaidi@eecs.umich.edu 1142657Ssaidi@eecs.umich.edubool 1153349Sbinkertn@umich.eduBridge::BridgePort::queueForSendTiming(PacketPtr pkt) 1162657Ssaidi@eecs.umich.edu{ 1174432Ssaidi@eecs.umich.edu if (queueFull()) { 1184432Ssaidi@eecs.umich.edu DPRINTF(BusBridge, "Queue full, returning false\n"); 1192657Ssaidi@eecs.umich.edu return false; 1204432Ssaidi@eecs.umich.edu } 1212657Ssaidi@eecs.umich.edu 1222657Ssaidi@eecs.umich.edu if (pkt->isResponse()) { 1232643Sstever@eecs.umich.edu // This is a response for a request we forwarded earlier. The 1242643Sstever@eecs.umich.edu // corresponding PacketBuffer should be stored in the packet's 1252643Sstever@eecs.umich.edu // senderState field. 1262643Sstever@eecs.umich.edu PacketBuffer *buf = dynamic_cast<PacketBuffer*>(pkt->senderState); 1272643Sstever@eecs.umich.edu assert(buf != NULL); 1282643Sstever@eecs.umich.edu // set up new packet dest & senderState based on values saved 1292643Sstever@eecs.umich.edu // from original request 1302643Sstever@eecs.umich.edu buf->fixResponse(pkt); 1312657Ssaidi@eecs.umich.edu DPRINTF(BusBridge, "restoring sender state: %#X, from packet buffer: %#X\n", 1322657Ssaidi@eecs.umich.edu pkt->senderState, buf); 1332643Sstever@eecs.umich.edu DPRINTF(BusBridge, " is response, new dest %d\n", pkt->getDest()); 1342643Sstever@eecs.umich.edu delete buf; 1352643Sstever@eecs.umich.edu } 1362643Sstever@eecs.umich.edu 1372643Sstever@eecs.umich.edu Tick readyTime = curTick + delay; 1382643Sstever@eecs.umich.edu PacketBuffer *buf = new PacketBuffer(pkt, readyTime); 1392657Ssaidi@eecs.umich.edu DPRINTF(BusBridge, "old sender state: %#X, new sender state: %#X\n", 1402657Ssaidi@eecs.umich.edu buf->origSenderState, buf); 1412643Sstever@eecs.umich.edu 1422643Sstever@eecs.umich.edu // If we're about to put this packet at the head of the queue, we 1432643Sstever@eecs.umich.edu // need to schedule an event to do the transmit. Otherwise there 1442643Sstever@eecs.umich.edu // should already be an event scheduled for sending the head 1452643Sstever@eecs.umich.edu // packet. 1462643Sstever@eecs.umich.edu if (sendQueue.empty()) { 1472643Sstever@eecs.umich.edu sendEvent.schedule(readyTime); 1482568SN/A } 1492643Sstever@eecs.umich.edu 1502643Sstever@eecs.umich.edu sendQueue.push_back(buf); 1512643Sstever@eecs.umich.edu 1522568SN/A return true; 1532568SN/A} 1542568SN/A 1552568SN/Avoid 1562643Sstever@eecs.umich.eduBridge::BridgePort::trySend() 1572568SN/A{ 1582643Sstever@eecs.umich.edu assert(!sendQueue.empty()); 1592568SN/A 1602657Ssaidi@eecs.umich.edu bool was_full = queueFull(); 1614432Ssaidi@eecs.umich.edu int pbs = peerBlockSize(); 1622657Ssaidi@eecs.umich.edu 1632643Sstever@eecs.umich.edu PacketBuffer *buf = sendQueue.front(); 1642643Sstever@eecs.umich.edu 1652643Sstever@eecs.umich.edu assert(buf->ready <= curTick); 1662643Sstever@eecs.umich.edu 1673349Sbinkertn@umich.edu PacketPtr pkt = buf->pkt; 1682643Sstever@eecs.umich.edu 1694432Ssaidi@eecs.umich.edu pkt->flags &= ~SNOOP_COMMIT; //CLear it if it was set 1704432Ssaidi@eecs.umich.edu 1714432Ssaidi@eecs.umich.edu if (pkt->cmd == MemCmd::WriteInvalidateReq && fixPartialWrite && 1724432Ssaidi@eecs.umich.edu pkt->getOffset(pbs) && pkt->getSize() != pbs) { 1734432Ssaidi@eecs.umich.edu buf->partialWriteFix(this); 1744432Ssaidi@eecs.umich.edu pkt = buf->pkt; 1754432Ssaidi@eecs.umich.edu } 1764432Ssaidi@eecs.umich.edu 1772643Sstever@eecs.umich.edu DPRINTF(BusBridge, "trySend: origSrc %d dest %d addr 0x%x\n", 1782643Sstever@eecs.umich.edu buf->origSrc, pkt->getDest(), pkt->getAddr()); 1792643Sstever@eecs.umich.edu 1804432Ssaidi@eecs.umich.edu 1812643Sstever@eecs.umich.edu if (sendTiming(pkt)) { 1822643Sstever@eecs.umich.edu // send successful 1832643Sstever@eecs.umich.edu sendQueue.pop_front(); 1842643Sstever@eecs.umich.edu buf->pkt = NULL; // we no longer own packet, so it's not safe to look at it 1852657Ssaidi@eecs.umich.edu 1862657Ssaidi@eecs.umich.edu if (buf->expectResponse) { 1872657Ssaidi@eecs.umich.edu // Must wait for response. We just need to count outstanding 1882657Ssaidi@eecs.umich.edu // responses (in case we want to cap them); PacketBuffer 1892657Ssaidi@eecs.umich.edu // pointer will be recovered on response. 1902657Ssaidi@eecs.umich.edu ++outstandingResponses; 1912657Ssaidi@eecs.umich.edu DPRINTF(BusBridge, " successful: awaiting response (%d)\n", 1922657Ssaidi@eecs.umich.edu outstandingResponses); 1932657Ssaidi@eecs.umich.edu } else { 1942657Ssaidi@eecs.umich.edu // no response expected... deallocate packet buffer now. 1952657Ssaidi@eecs.umich.edu DPRINTF(BusBridge, " successful: no response expected\n"); 1962657Ssaidi@eecs.umich.edu delete buf; 1972657Ssaidi@eecs.umich.edu } 1982657Ssaidi@eecs.umich.edu 1992657Ssaidi@eecs.umich.edu // If there are more packets to send, schedule event to try again. 2002657Ssaidi@eecs.umich.edu if (!sendQueue.empty()) { 2012657Ssaidi@eecs.umich.edu buf = sendQueue.front(); 2022657Ssaidi@eecs.umich.edu sendEvent.schedule(std::max(buf->ready, curTick + 1)); 2032657Ssaidi@eecs.umich.edu } 2042657Ssaidi@eecs.umich.edu // Let things start sending again 2052657Ssaidi@eecs.umich.edu if (was_full) { 2062657Ssaidi@eecs.umich.edu DPRINTF(BusBridge, "Queue was full, sending retry\n"); 2072657Ssaidi@eecs.umich.edu otherPort->sendRetry(); 2082657Ssaidi@eecs.umich.edu } 2092657Ssaidi@eecs.umich.edu 2102643Sstever@eecs.umich.edu } else { 2112643Sstever@eecs.umich.edu DPRINTF(BusBridge, " unsuccessful\n"); 2124432Ssaidi@eecs.umich.edu buf->undoPartialWriteFix(); 2132643Sstever@eecs.umich.edu } 2142568SN/A} 2152568SN/A 2162568SN/A 2172657Ssaidi@eecs.umich.eduvoid 2182568SN/ABridge::BridgePort::recvRetry() 2192568SN/A{ 2202657Ssaidi@eecs.umich.edu trySend(); 2212568SN/A} 2222568SN/A 2232643Sstever@eecs.umich.edu/** Function called by the port when the bus is receiving a Atomic 2242568SN/A * transaction.*/ 2252568SN/ATick 2263349Sbinkertn@umich.eduBridge::BridgePort::recvAtomic(PacketPtr pkt) 2272568SN/A{ 2282643Sstever@eecs.umich.edu return otherPort->sendAtomic(pkt) + delay; 2292568SN/A} 2302568SN/A 2312643Sstever@eecs.umich.edu/** Function called by the port when the bus is receiving a Functional 2322568SN/A * transaction.*/ 2332568SN/Avoid 2343349Sbinkertn@umich.eduBridge::BridgePort::recvFunctional(PacketPtr pkt) 2352568SN/A{ 2362643Sstever@eecs.umich.edu std::list<PacketBuffer*>::iterator i; 2372568SN/A bool pktContinue = true; 2382568SN/A 2392643Sstever@eecs.umich.edu for (i = sendQueue.begin(); i != sendQueue.end(); ++i) { 2402643Sstever@eecs.umich.edu if (pkt->intersect((*i)->pkt)) { 2412643Sstever@eecs.umich.edu pktContinue &= fixPacket(pkt, (*i)->pkt); 2422568SN/A } 2432568SN/A } 2442568SN/A 2452568SN/A if (pktContinue) { 2462643Sstever@eecs.umich.edu otherPort->sendFunctional(pkt); 2472568SN/A } 2482568SN/A} 2492568SN/A 2502643Sstever@eecs.umich.edu/** Function called by the port when the bus is receiving a status change.*/ 2512568SN/Avoid 2522643Sstever@eecs.umich.eduBridge::BridgePort::recvStatusChange(Port::Status status) 2532568SN/A{ 2542643Sstever@eecs.umich.edu otherPort->sendStatusChange(status); 2552568SN/A} 2562568SN/A 2572568SN/Avoid 2582643Sstever@eecs.umich.eduBridge::BridgePort::getDeviceAddressRanges(AddrRangeList &resp, 2592643Sstever@eecs.umich.edu AddrRangeList &snoop) 2602568SN/A{ 2612643Sstever@eecs.umich.edu otherPort->getPeerAddressRanges(resp, snoop); 2622568SN/A} 2632568SN/A 2642568SN/ABEGIN_DECLARE_SIM_OBJECT_PARAMS(Bridge) 2652568SN/A 2662568SN/A Param<int> queue_size_a; 2672568SN/A Param<int> queue_size_b; 2682568SN/A Param<Tick> delay; 2692568SN/A Param<bool> write_ack; 2704432Ssaidi@eecs.umich.edu Param<bool> fix_partial_write_a; 2714432Ssaidi@eecs.umich.edu Param<bool> fix_partial_write_b; 2722568SN/A 2732568SN/AEND_DECLARE_SIM_OBJECT_PARAMS(Bridge) 2742568SN/A 2752568SN/ABEGIN_INIT_SIM_OBJECT_PARAMS(Bridge) 2762568SN/A 2772568SN/A INIT_PARAM(queue_size_a, "The size of the queue for data coming into side a"), 2782568SN/A INIT_PARAM(queue_size_b, "The size of the queue for data coming into side b"), 2792568SN/A INIT_PARAM(delay, "The miminum delay to cross this bridge"), 2804432Ssaidi@eecs.umich.edu INIT_PARAM(write_ack, "Acknowledge any writes that are received."), 2814432Ssaidi@eecs.umich.edu INIT_PARAM(fix_partial_write_a, "Fixup any partial block writes that are received"), 2824432Ssaidi@eecs.umich.edu INIT_PARAM(fix_partial_write_b, "Fixup any partial block writes that are received") 2832568SN/A 2842568SN/AEND_INIT_SIM_OBJECT_PARAMS(Bridge) 2852568SN/A 2862568SN/ACREATE_SIM_OBJECT(Bridge) 2872568SN/A{ 2882568SN/A return new Bridge(getInstanceName(), queue_size_a, queue_size_b, delay, 2894432Ssaidi@eecs.umich.edu write_ack, fix_partial_write_a, fix_partial_write_b); 2902568SN/A} 2912568SN/A 2922568SN/AREGISTER_SIM_OBJECT("Bridge", Bridge) 293