coherent_xbar.cc revision 11130
12497SN/A/* 210719SMarco.Balboni@ARM.com * Copyright (c) 2011-2015 ARM Limited 38711SN/A * All rights reserved 48711SN/A * 58711SN/A * The license below extends only to copyright in the software and shall 68711SN/A * not be construed as granting a license to any other intellectual 78711SN/A * property including but not limited to intellectual property relating 88711SN/A * to a hardware implementation of the functionality of the software 98711SN/A * licensed hereunder. You may use the software subject to the license 108711SN/A * terms below provided that you ensure that this notice is replicated 118711SN/A * unmodified and in its entirety in all distributions of the software, 128711SN/A * modified or unmodified, in source code or in binary form. 138711SN/A * 142497SN/A * Copyright (c) 2006 The Regents of The University of Michigan 152497SN/A * All rights reserved. 162497SN/A * 172497SN/A * Redistribution and use in source and binary forms, with or without 182497SN/A * modification, are permitted provided that the following conditions are 192497SN/A * met: redistributions of source code must retain the above copyright 202497SN/A * notice, this list of conditions and the following disclaimer; 212497SN/A * redistributions in binary form must reproduce the above copyright 222497SN/A * notice, this list of conditions and the following disclaimer in the 232497SN/A * documentation and/or other materials provided with the distribution; 242497SN/A * neither the name of the copyright holders nor the names of its 252497SN/A * contributors may be used to endorse or promote products derived from 262497SN/A * this software without specific prior written permission. 272497SN/A * 282497SN/A * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 292497SN/A * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 302497SN/A * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 312497SN/A * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 322497SN/A * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 332497SN/A * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 342497SN/A * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 352497SN/A * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 362497SN/A * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 372497SN/A * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 382497SN/A * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 392665SN/A * 402665SN/A * Authors: Ali Saidi 418715SN/A * Andreas Hansson 428922SN/A * William Wang 432497SN/A */ 442497SN/A 452497SN/A/** 462982SN/A * @file 4710405Sandreas.hansson@arm.com * Definition of a crossbar object. 482497SN/A */ 492497SN/A 502846SN/A#include "base/misc.hh" 512548SN/A#include "base/trace.hh" 5210405Sandreas.hansson@arm.com#include "debug/AddrRanges.hh" 5310405Sandreas.hansson@arm.com#include "debug/CoherentXBar.hh" 5410405Sandreas.hansson@arm.com#include "mem/coherent_xbar.hh" 559524SN/A#include "sim/system.hh" 562497SN/A 5710405Sandreas.hansson@arm.comCoherentXBar::CoherentXBar(const CoherentXBarParams *p) 5810719SMarco.Balboni@ARM.com : BaseXBar(p), system(p->system), snoopFilter(p->snoop_filter), 5910719SMarco.Balboni@ARM.com snoopResponseLatency(p->snoop_response_latency) 607523SN/A{ 618851SN/A // create the ports based on the size of the master and slave 628948SN/A // vector ports, and the presence of the default port, the ports 638948SN/A // are enumerated starting from zero 648851SN/A for (int i = 0; i < p->port_master_connection_count; ++i) { 659095SN/A std::string portName = csprintf("%s.master[%d]", name(), i); 6610405Sandreas.hansson@arm.com MasterPort* bp = new CoherentXBarMasterPort(portName, *this, i); 678922SN/A masterPorts.push_back(bp); 689715SN/A reqLayers.push_back(new ReqLayer(*bp, *this, 699715SN/A csprintf(".reqLayer%d", i))); 7010713Sandreas.hansson@arm.com snoopLayers.push_back(new SnoopRespLayer(*bp, *this, 7110713Sandreas.hansson@arm.com csprintf(".snoopLayer%d", i))); 728851SN/A } 738851SN/A 748948SN/A // see if we have a default slave device connected and if so add 758948SN/A // our corresponding master port 768915SN/A if (p->port_default_connection_count) { 779031SN/A defaultPortID = masterPorts.size(); 789095SN/A std::string portName = name() + ".default"; 7910405Sandreas.hansson@arm.com MasterPort* bp = new CoherentXBarMasterPort(portName, *this, 809036SN/A defaultPortID); 818922SN/A masterPorts.push_back(bp); 829715SN/A reqLayers.push_back(new ReqLayer(*bp, *this, csprintf(".reqLayer%d", 839715SN/A defaultPortID))); 8410713Sandreas.hansson@arm.com snoopLayers.push_back(new SnoopRespLayer(*bp, *this, 8510713Sandreas.hansson@arm.com csprintf(".snoopLayer%d", 8610713Sandreas.hansson@arm.com defaultPortID))); 878915SN/A } 888915SN/A 898948SN/A // create the slave ports, once again starting at zero 908851SN/A for (int i = 0; i < p->port_slave_connection_count; ++i) { 919095SN/A std::string portName = csprintf("%s.slave[%d]", name(), i); 9210888Sandreas.hansson@arm.com QueuedSlavePort* bp = new CoherentXBarSlavePort(portName, *this, i); 938922SN/A slavePorts.push_back(bp); 949715SN/A respLayers.push_back(new RespLayer(*bp, *this, 959715SN/A csprintf(".respLayer%d", i))); 969716SN/A snoopRespPorts.push_back(new SnoopRespPort(*bp, *this)); 978851SN/A } 988851SN/A 9910402SN/A if (snoopFilter) 10010402SN/A snoopFilter->setSlavePorts(slavePorts); 10110402SN/A 1027523SN/A clearPortCache(); 1037523SN/A} 1047523SN/A 10510405Sandreas.hansson@arm.comCoherentXBar::~CoherentXBar() 1069715SN/A{ 10710405Sandreas.hansson@arm.com for (auto l: reqLayers) 10810405Sandreas.hansson@arm.com delete l; 10910405Sandreas.hansson@arm.com for (auto l: respLayers) 11010405Sandreas.hansson@arm.com delete l; 11110405Sandreas.hansson@arm.com for (auto l: snoopLayers) 11210405Sandreas.hansson@arm.com delete l; 11310405Sandreas.hansson@arm.com for (auto p: snoopRespPorts) 11410405Sandreas.hansson@arm.com delete p; 1159715SN/A} 1169715SN/A 1172568SN/Avoid 11810405Sandreas.hansson@arm.comCoherentXBar::init() 1192568SN/A{ 1209278SN/A // the base class is responsible for determining the block size 12110405Sandreas.hansson@arm.com BaseXBar::init(); 1229278SN/A 1238948SN/A // iterate over our slave ports and determine which of our 1248948SN/A // neighbouring master ports are snooping and add them as snoopers 12510405Sandreas.hansson@arm.com for (const auto& p: slavePorts) { 1269088SN/A // check if the connected master port is snooping 12710405Sandreas.hansson@arm.com if (p->isSnooping()) { 12810405Sandreas.hansson@arm.com DPRINTF(AddrRanges, "Adding snooping master %s\n", 12910405Sandreas.hansson@arm.com p->getMasterPort().name()); 13010405Sandreas.hansson@arm.com snoopPorts.push_back(p); 1318711SN/A } 1328711SN/A } 1332568SN/A 1349036SN/A if (snoopPorts.empty()) 13510405Sandreas.hansson@arm.com warn("CoherentXBar %s has no snooping ports attached!\n", name()); 1363244SN/A} 1373244SN/A 1388948SN/Abool 13910405Sandreas.hansson@arm.comCoherentXBar::recvTimingReq(PacketPtr pkt, PortID slave_port_id) 1403244SN/A{ 14110883Sali.jafri@arm.com // @todo temporary hack to deal with memory corruption issue until 14210883Sali.jafri@arm.com // 4-phase transactions are complete 14310883Sali.jafri@arm.com for (int x = 0; x < pendingDelete.size(); x++) 14410883Sali.jafri@arm.com delete pendingDelete[x]; 14510883Sali.jafri@arm.com pendingDelete.clear(); 14610883Sali.jafri@arm.com 1478975SN/A // determine the source port based on the id 1489032SN/A SlavePort *src_port = slavePorts[slave_port_id]; 1493244SN/A 1509091SN/A // remember if the packet is an express snoop 1519091SN/A bool is_express_snoop = pkt->isExpressSnoop(); 15210656Sandreas.hansson@arm.com bool is_inhibited = pkt->memInhibitAsserted(); 15310656Sandreas.hansson@arm.com // for normal requests, going downstream, the express snoop flag 15410656Sandreas.hansson@arm.com // and the inhibited flag should always be the same 15510656Sandreas.hansson@arm.com assert(is_express_snoop == is_inhibited); 1569091SN/A 1579612SN/A // determine the destination based on the address 1589712SN/A PortID master_port_id = findPort(pkt->getAddr()); 1599612SN/A 16010405Sandreas.hansson@arm.com // test if the crossbar should be considered occupied for the current 1619033SN/A // port, and exclude express snoops from the check 1629715SN/A if (!is_express_snoop && !reqLayers[master_port_id]->tryTiming(src_port)) { 16310405Sandreas.hansson@arm.com DPRINTF(CoherentXBar, "recvTimingReq: src %s %s 0x%x BUSY\n", 1648949SN/A src_port->name(), pkt->cmdString(), pkt->getAddr()); 1653244SN/A return false; 1663244SN/A } 1673244SN/A 16810405Sandreas.hansson@arm.com DPRINTF(CoherentXBar, "recvTimingReq: src %s %s expr %d 0x%x\n", 1699091SN/A src_port->name(), pkt->cmdString(), is_express_snoop, 1709091SN/A pkt->getAddr()); 1715197SN/A 1729712SN/A // store size and command as they might be modified when 1739712SN/A // forwarding the packet 1749712SN/A unsigned int pkt_size = pkt->hasData() ? pkt->getSize() : 0; 1759712SN/A unsigned int pkt_cmd = pkt->cmdToIndex(); 1769712SN/A 17710719SMarco.Balboni@ARM.com // store the old header delay so we can restore it if needed 17810719SMarco.Balboni@ARM.com Tick old_header_delay = pkt->headerDelay; 17910719SMarco.Balboni@ARM.com 18010719SMarco.Balboni@ARM.com // a request sees the frontend and forward latency 18110719SMarco.Balboni@ARM.com Tick xbar_delay = (frontendLatency + forwardLatency) * clockPeriod(); 18210719SMarco.Balboni@ARM.com 18310719SMarco.Balboni@ARM.com // set the packet header and payload delay 18410719SMarco.Balboni@ARM.com calcPacketTiming(pkt, xbar_delay); 18510719SMarco.Balboni@ARM.com 18610719SMarco.Balboni@ARM.com // determine how long to be crossbar layer is busy 18710719SMarco.Balboni@ARM.com Tick packetFinishTime = clockEdge(Cycles(1)) + pkt->payloadDelay; 1884912SN/A 18910821Sandreas.hansson@arm.com if (!system->bypassCaches()) { 19011127Sandreas.hansson@arm.com assert(pkt->snoopDelay == 0); 19111127Sandreas.hansson@arm.com 1928979SN/A // the packet is a memory-mapped request and should be 1938979SN/A // broadcasted to our snoopers but the source 19410402SN/A if (snoopFilter) { 19510402SN/A // check with the snoop filter where to forward this packet 19610402SN/A auto sf_res = snoopFilter->lookupRequest(pkt, *src_port); 19711126Sandreas.hansson@arm.com // the time required by a packet to be delivered through 19811126Sandreas.hansson@arm.com // the xbar has to be charged also with to lookup latency 19911126Sandreas.hansson@arm.com // of the snoop filter 20010719SMarco.Balboni@ARM.com pkt->headerDelay += sf_res.second * clockPeriod(); 20110405Sandreas.hansson@arm.com DPRINTF(CoherentXBar, "recvTimingReq: src %s %s 0x%x"\ 20210402SN/A " SF size: %i lat: %i\n", src_port->name(), 20310402SN/A pkt->cmdString(), pkt->getAddr(), sf_res.first.size(), 20410402SN/A sf_res.second); 20510402SN/A forwardTiming(pkt, slave_port_id, sf_res.first); 20610402SN/A } else { 20710402SN/A forwardTiming(pkt, slave_port_id); 20810402SN/A } 20911127Sandreas.hansson@arm.com 21011127Sandreas.hansson@arm.com // add the snoop delay to our header delay, and then reset it 21111127Sandreas.hansson@arm.com pkt->headerDelay += pkt->snoopDelay; 21211127Sandreas.hansson@arm.com pkt->snoopDelay = 0; 2138979SN/A } 2148948SN/A 21510883Sali.jafri@arm.com // forwardTiming snooped into peer caches of the sender, and if 21610883Sali.jafri@arm.com // this is a clean evict, but the packet is found in a cache, do 21710883Sali.jafri@arm.com // not forward it 21810883Sali.jafri@arm.com if (pkt->cmd == MemCmd::CleanEvict && pkt->isBlockCached()) { 21910883Sali.jafri@arm.com DPRINTF(CoherentXBar, "recvTimingReq: Clean evict 0x%x still cached, " 22010883Sali.jafri@arm.com "not forwarding\n", pkt->getAddr()); 22110883Sali.jafri@arm.com 22210883Sali.jafri@arm.com // update the layer state and schedule an idle event 22310883Sali.jafri@arm.com reqLayers[master_port_id]->succeededTiming(packetFinishTime); 22410883Sali.jafri@arm.com pendingDelete.push_back(pkt); 22510883Sali.jafri@arm.com return true; 22610883Sali.jafri@arm.com } 22710883Sali.jafri@arm.com 22810656Sandreas.hansson@arm.com // remember if the packet will generate a snoop response 22910656Sandreas.hansson@arm.com const bool expect_snoop_resp = !is_inhibited && pkt->memInhibitAsserted(); 23010656Sandreas.hansson@arm.com const bool expect_response = pkt->needsResponse() && 23110656Sandreas.hansson@arm.com !pkt->memInhibitAsserted(); 2328915SN/A 2339612SN/A // since it is a normal request, attempt to send the packet 2349712SN/A bool success = masterPorts[master_port_id]->sendTimingReq(pkt); 2358948SN/A 23610821Sandreas.hansson@arm.com if (snoopFilter && !system->bypassCaches()) { 23710402SN/A // Let the snoop filter know about the success of the send operation 23810402SN/A snoopFilter->updateRequest(pkt, *src_port, !success); 23910402SN/A } 24010402SN/A 24110656Sandreas.hansson@arm.com // check if we were successful in sending the packet onwards 24210656Sandreas.hansson@arm.com if (!success) { 24310656Sandreas.hansson@arm.com // express snoops and inhibited packets should never be forced 24410656Sandreas.hansson@arm.com // to retry 24510656Sandreas.hansson@arm.com assert(!is_express_snoop); 24610656Sandreas.hansson@arm.com assert(!pkt->memInhibitAsserted()); 24710656Sandreas.hansson@arm.com 24810719SMarco.Balboni@ARM.com // restore the header delay 24910719SMarco.Balboni@ARM.com pkt->headerDelay = old_header_delay; 25010656Sandreas.hansson@arm.com 25110656Sandreas.hansson@arm.com DPRINTF(CoherentXBar, "recvTimingReq: src %s %s 0x%x RETRY\n", 25210656Sandreas.hansson@arm.com src_port->name(), pkt->cmdString(), pkt->getAddr()); 25310656Sandreas.hansson@arm.com 25410656Sandreas.hansson@arm.com // update the layer state and schedule an idle event 25510656Sandreas.hansson@arm.com reqLayers[master_port_id]->failedTiming(src_port, 25610719SMarco.Balboni@ARM.com clockEdge(Cycles(1))); 2579091SN/A } else { 25810656Sandreas.hansson@arm.com // express snoops currently bypass the crossbar state entirely 25910656Sandreas.hansson@arm.com if (!is_express_snoop) { 26010656Sandreas.hansson@arm.com // if this particular request will generate a snoop 26110656Sandreas.hansson@arm.com // response 26210656Sandreas.hansson@arm.com if (expect_snoop_resp) { 26310656Sandreas.hansson@arm.com // we should never have an exsiting request outstanding 26410656Sandreas.hansson@arm.com assert(outstandingSnoop.find(pkt->req) == 26510656Sandreas.hansson@arm.com outstandingSnoop.end()); 26610656Sandreas.hansson@arm.com outstandingSnoop.insert(pkt->req); 2678948SN/A 26810656Sandreas.hansson@arm.com // basic sanity check on the outstanding snoops 26910656Sandreas.hansson@arm.com panic_if(outstandingSnoop.size() > 512, 27010656Sandreas.hansson@arm.com "Outstanding snoop requests exceeded 512\n"); 27110656Sandreas.hansson@arm.com } 2728948SN/A 27310656Sandreas.hansson@arm.com // remember where to route the normal response to 27410656Sandreas.hansson@arm.com if (expect_response || expect_snoop_resp) { 27510656Sandreas.hansson@arm.com assert(routeTo.find(pkt->req) == routeTo.end()); 27610656Sandreas.hansson@arm.com routeTo[pkt->req] = slave_port_id; 2779549SN/A 27810656Sandreas.hansson@arm.com panic_if(routeTo.size() > 512, 27910656Sandreas.hansson@arm.com "Routing table exceeds 512 packets\n"); 28010656Sandreas.hansson@arm.com } 2818948SN/A 28210405Sandreas.hansson@arm.com // update the layer state and schedule an idle event 2839715SN/A reqLayers[master_port_id]->succeededTiming(packetFinishTime); 2849091SN/A } 2858975SN/A 28610656Sandreas.hansson@arm.com // stats updates only consider packets that were successfully sent 2879712SN/A pktCount[slave_port_id][master_port_id]++; 28810405Sandreas.hansson@arm.com pktSize[slave_port_id][master_port_id] += pkt_size; 2899712SN/A transDist[pkt_cmd]++; 29010656Sandreas.hansson@arm.com 29110656Sandreas.hansson@arm.com if (is_express_snoop) 29210656Sandreas.hansson@arm.com snoops++; 2939712SN/A } 2949712SN/A 2959091SN/A return success; 2968975SN/A} 2978975SN/A 2988975SN/Abool 29910405Sandreas.hansson@arm.comCoherentXBar::recvTimingResp(PacketPtr pkt, PortID master_port_id) 3008975SN/A{ 3018975SN/A // determine the source port based on the id 3029032SN/A MasterPort *src_port = masterPorts[master_port_id]; 3038975SN/A 30410656Sandreas.hansson@arm.com // determine the destination 30510656Sandreas.hansson@arm.com const auto route_lookup = routeTo.find(pkt->req); 30610656Sandreas.hansson@arm.com assert(route_lookup != routeTo.end()); 30710656Sandreas.hansson@arm.com const PortID slave_port_id = route_lookup->second; 30810572Sandreas.hansson@arm.com assert(slave_port_id != InvalidPortID); 30910572Sandreas.hansson@arm.com assert(slave_port_id < respLayers.size()); 3109713SN/A 31110405Sandreas.hansson@arm.com // test if the crossbar should be considered occupied for the 31210405Sandreas.hansson@arm.com // current port 3139715SN/A if (!respLayers[slave_port_id]->tryTiming(src_port)) { 31410405Sandreas.hansson@arm.com DPRINTF(CoherentXBar, "recvTimingResp: src %s %s 0x%x BUSY\n", 3158975SN/A src_port->name(), pkt->cmdString(), pkt->getAddr()); 3168975SN/A return false; 3178975SN/A } 3188975SN/A 31910405Sandreas.hansson@arm.com DPRINTF(CoherentXBar, "recvTimingResp: src %s %s 0x%x\n", 3208975SN/A src_port->name(), pkt->cmdString(), pkt->getAddr()); 3218975SN/A 3229712SN/A // store size and command as they might be modified when 3239712SN/A // forwarding the packet 3249712SN/A unsigned int pkt_size = pkt->hasData() ? pkt->getSize() : 0; 3259712SN/A unsigned int pkt_cmd = pkt->cmdToIndex(); 3269712SN/A 32710719SMarco.Balboni@ARM.com // a response sees the response latency 32810719SMarco.Balboni@ARM.com Tick xbar_delay = responseLatency * clockPeriod(); 32910719SMarco.Balboni@ARM.com 33010719SMarco.Balboni@ARM.com // set the packet header and payload delay 33110719SMarco.Balboni@ARM.com calcPacketTiming(pkt, xbar_delay); 33210719SMarco.Balboni@ARM.com 33310719SMarco.Balboni@ARM.com // determine how long to be crossbar layer is busy 33410719SMarco.Balboni@ARM.com Tick packetFinishTime = clockEdge(Cycles(1)) + pkt->payloadDelay; 3358975SN/A 33610821Sandreas.hansson@arm.com if (snoopFilter && !system->bypassCaches()) { 33710402SN/A // let the snoop filter inspect the response and update its state 33810402SN/A snoopFilter->updateResponse(pkt, *slavePorts[slave_port_id]); 33910402SN/A } 34010402SN/A 34110888Sandreas.hansson@arm.com // send the packet through the destination slave port and pay for 34210888Sandreas.hansson@arm.com // any outstanding header delay 34310888Sandreas.hansson@arm.com Tick latency = pkt->headerDelay; 34410888Sandreas.hansson@arm.com pkt->headerDelay = 0; 34510888Sandreas.hansson@arm.com slavePorts[slave_port_id]->schedTimingResp(pkt, curTick() + latency); 3468975SN/A 34710656Sandreas.hansson@arm.com // remove the request from the routing table 34810656Sandreas.hansson@arm.com routeTo.erase(route_lookup); 34910656Sandreas.hansson@arm.com 3509715SN/A respLayers[slave_port_id]->succeededTiming(packetFinishTime); 3518975SN/A 3529712SN/A // stats updates 3539712SN/A pktCount[slave_port_id][master_port_id]++; 35410405Sandreas.hansson@arm.com pktSize[slave_port_id][master_port_id] += pkt_size; 3559712SN/A transDist[pkt_cmd]++; 3569712SN/A 3578975SN/A return true; 3588975SN/A} 3598975SN/A 3608975SN/Avoid 36110405Sandreas.hansson@arm.comCoherentXBar::recvTimingSnoopReq(PacketPtr pkt, PortID master_port_id) 3628975SN/A{ 36310405Sandreas.hansson@arm.com DPRINTF(CoherentXBar, "recvTimingSnoopReq: src %s %s 0x%x\n", 3649032SN/A masterPorts[master_port_id]->name(), pkt->cmdString(), 3658975SN/A pkt->getAddr()); 3668975SN/A 3679712SN/A // update stats here as we know the forwarding will succeed 3689712SN/A transDist[pkt->cmdToIndex()]++; 36910405Sandreas.hansson@arm.com snoops++; 3709712SN/A 3718975SN/A // we should only see express snoops from caches 3728975SN/A assert(pkt->isExpressSnoop()); 3738975SN/A 37411127Sandreas.hansson@arm.com // set the packet header and payload delay, for now use forward latency 37511127Sandreas.hansson@arm.com // @todo Assess the choice of latency further 37611127Sandreas.hansson@arm.com calcPacketTiming(pkt, forwardLatency * clockPeriod()); 37711127Sandreas.hansson@arm.com 37810656Sandreas.hansson@arm.com // remeber if the packet is inhibited so we can see if it changes 37910656Sandreas.hansson@arm.com const bool is_inhibited = pkt->memInhibitAsserted(); 3809032SN/A 38111127Sandreas.hansson@arm.com assert(pkt->snoopDelay == 0); 38211127Sandreas.hansson@arm.com 38310402SN/A if (snoopFilter) { 38410402SN/A // let the Snoop Filter work its magic and guide probing 38510402SN/A auto sf_res = snoopFilter->lookupSnoop(pkt); 38611126Sandreas.hansson@arm.com // the time required by a packet to be delivered through 38711126Sandreas.hansson@arm.com // the xbar has to be charged also with to lookup latency 38811126Sandreas.hansson@arm.com // of the snoop filter 38911126Sandreas.hansson@arm.com pkt->headerDelay += sf_res.second * clockPeriod(); 39010405Sandreas.hansson@arm.com DPRINTF(CoherentXBar, "recvTimingSnoopReq: src %s %s 0x%x"\ 39110402SN/A " SF size: %i lat: %i\n", masterPorts[master_port_id]->name(), 39210402SN/A pkt->cmdString(), pkt->getAddr(), sf_res.first.size(), 39310402SN/A sf_res.second); 39410402SN/A 39510402SN/A // forward to all snoopers 39610402SN/A forwardTiming(pkt, InvalidPortID, sf_res.first); 39710402SN/A } else { 39810402SN/A forwardTiming(pkt, InvalidPortID); 39910402SN/A } 4008975SN/A 40111127Sandreas.hansson@arm.com // add the snoop delay to our header delay, and then reset it 40211127Sandreas.hansson@arm.com pkt->headerDelay += pkt->snoopDelay; 40311127Sandreas.hansson@arm.com pkt->snoopDelay = 0; 40411127Sandreas.hansson@arm.com 40510656Sandreas.hansson@arm.com // if we can expect a response, remember how to route it 40610656Sandreas.hansson@arm.com if (!is_inhibited && pkt->memInhibitAsserted()) { 40710656Sandreas.hansson@arm.com assert(routeTo.find(pkt->req) == routeTo.end()); 40810656Sandreas.hansson@arm.com routeTo[pkt->req] = master_port_id; 40910656Sandreas.hansson@arm.com } 41010656Sandreas.hansson@arm.com 4118975SN/A // a snoop request came from a connected slave device (one of 4128975SN/A // our master ports), and if it is not coming from the slave 4138975SN/A // device responsible for the address range something is 4148975SN/A // wrong, hence there is nothing further to do as the packet 4158975SN/A // would be going back to where it came from 4169032SN/A assert(master_port_id == findPort(pkt->getAddr())); 4178975SN/A} 4188975SN/A 4198975SN/Abool 42010405Sandreas.hansson@arm.comCoherentXBar::recvTimingSnoopResp(PacketPtr pkt, PortID slave_port_id) 4218975SN/A{ 4228975SN/A // determine the source port based on the id 4239032SN/A SlavePort* src_port = slavePorts[slave_port_id]; 4248975SN/A 42510656Sandreas.hansson@arm.com // get the destination 42610656Sandreas.hansson@arm.com const auto route_lookup = routeTo.find(pkt->req); 42710656Sandreas.hansson@arm.com assert(route_lookup != routeTo.end()); 42810656Sandreas.hansson@arm.com const PortID dest_port_id = route_lookup->second; 42910572Sandreas.hansson@arm.com assert(dest_port_id != InvalidPortID); 4309714SN/A 4319714SN/A // determine if the response is from a snoop request we 4329714SN/A // created as the result of a normal request (in which case it 43310656Sandreas.hansson@arm.com // should be in the outstandingSnoop), or if we merely forwarded 4349714SN/A // someone else's snoop request 43510656Sandreas.hansson@arm.com const bool forwardAsSnoop = outstandingSnoop.find(pkt->req) == 43610656Sandreas.hansson@arm.com outstandingSnoop.end(); 4379714SN/A 43810405Sandreas.hansson@arm.com // test if the crossbar should be considered occupied for the 43910405Sandreas.hansson@arm.com // current port, note that the check is bypassed if the response 44010405Sandreas.hansson@arm.com // is being passed on as a normal response since this is occupying 44110405Sandreas.hansson@arm.com // the response layer rather than the snoop response layer 4429715SN/A if (forwardAsSnoop) { 44310572Sandreas.hansson@arm.com assert(dest_port_id < snoopLayers.size()); 4449715SN/A if (!snoopLayers[dest_port_id]->tryTiming(src_port)) { 44510405Sandreas.hansson@arm.com DPRINTF(CoherentXBar, "recvTimingSnoopResp: src %s %s 0x%x BUSY\n", 4469715SN/A src_port->name(), pkt->cmdString(), pkt->getAddr()); 4479715SN/A return false; 4489715SN/A } 4499716SN/A } else { 4509716SN/A // get the master port that mirrors this slave port internally 4519716SN/A MasterPort* snoop_port = snoopRespPorts[slave_port_id]; 45210572Sandreas.hansson@arm.com assert(dest_port_id < respLayers.size()); 4539716SN/A if (!respLayers[dest_port_id]->tryTiming(snoop_port)) { 45410405Sandreas.hansson@arm.com DPRINTF(CoherentXBar, "recvTimingSnoopResp: src %s %s 0x%x BUSY\n", 4559716SN/A snoop_port->name(), pkt->cmdString(), pkt->getAddr()); 4569716SN/A return false; 4579716SN/A } 4588975SN/A } 4598975SN/A 46010405Sandreas.hansson@arm.com DPRINTF(CoherentXBar, "recvTimingSnoopResp: src %s %s 0x%x\n", 4618975SN/A src_port->name(), pkt->cmdString(), pkt->getAddr()); 4628975SN/A 4639712SN/A // store size and command as they might be modified when 4649712SN/A // forwarding the packet 4659712SN/A unsigned int pkt_size = pkt->hasData() ? pkt->getSize() : 0; 4669712SN/A unsigned int pkt_cmd = pkt->cmdToIndex(); 4679712SN/A 4688975SN/A // responses are never express snoops 4698975SN/A assert(!pkt->isExpressSnoop()); 4708975SN/A 47110719SMarco.Balboni@ARM.com // a snoop response sees the snoop response latency, and if it is 47210719SMarco.Balboni@ARM.com // forwarded as a normal response, the response latency 47310719SMarco.Balboni@ARM.com Tick xbar_delay = 47410719SMarco.Balboni@ARM.com (forwardAsSnoop ? snoopResponseLatency : responseLatency) * 47510719SMarco.Balboni@ARM.com clockPeriod(); 47610719SMarco.Balboni@ARM.com 47710719SMarco.Balboni@ARM.com // set the packet header and payload delay 47810719SMarco.Balboni@ARM.com calcPacketTiming(pkt, xbar_delay); 47910719SMarco.Balboni@ARM.com 48010719SMarco.Balboni@ARM.com // determine how long to be crossbar layer is busy 48110719SMarco.Balboni@ARM.com Tick packetFinishTime = clockEdge(Cycles(1)) + pkt->payloadDelay; 4828975SN/A 4839714SN/A // forward it either as a snoop response or a normal response 4849714SN/A if (forwardAsSnoop) { 4859714SN/A // this is a snoop response to a snoop request we forwarded, 4869714SN/A // e.g. coming from the L1 and going to the L2, and it should 4879714SN/A // be forwarded as a snoop response 48810402SN/A 48910402SN/A if (snoopFilter) { 49010402SN/A // update the probe filter so that it can properly track the line 49110402SN/A snoopFilter->updateSnoopForward(pkt, *slavePorts[slave_port_id], 49210402SN/A *masterPorts[dest_port_id]); 49310402SN/A } 49410402SN/A 4959712SN/A bool success M5_VAR_USED = 4969712SN/A masterPorts[dest_port_id]->sendTimingSnoopResp(pkt); 4979712SN/A pktCount[slave_port_id][dest_port_id]++; 49810405Sandreas.hansson@arm.com pktSize[slave_port_id][dest_port_id] += pkt_size; 4998975SN/A assert(success); 5009714SN/A 5019715SN/A snoopLayers[dest_port_id]->succeededTiming(packetFinishTime); 5023244SN/A } else { 5038975SN/A // we got a snoop response on one of our slave ports, 50410405Sandreas.hansson@arm.com // i.e. from a coherent master connected to the crossbar, and 50510405Sandreas.hansson@arm.com // since we created the snoop request as part of recvTiming, 50610405Sandreas.hansson@arm.com // this should now be a normal response again 50710656Sandreas.hansson@arm.com outstandingSnoop.erase(pkt->req); 5088948SN/A 50910656Sandreas.hansson@arm.com // this is a snoop response from a coherent master, hence it 51010656Sandreas.hansson@arm.com // should never go back to where the snoop response came from, 51110656Sandreas.hansson@arm.com // but instead to where the original request came from 5129712SN/A assert(slave_port_id != dest_port_id); 5138948SN/A 51410402SN/A if (snoopFilter) { 51510402SN/A // update the probe filter so that it can properly track the line 51610402SN/A snoopFilter->updateSnoopResponse(pkt, *slavePorts[slave_port_id], 51710402SN/A *slavePorts[dest_port_id]); 51810402SN/A } 51910402SN/A 52010405Sandreas.hansson@arm.com DPRINTF(CoherentXBar, "recvTimingSnoopResp: src %s %s 0x%x"\ 52110402SN/A " FWD RESP\n", src_port->name(), pkt->cmdString(), 52210402SN/A pkt->getAddr()); 52310402SN/A 5249714SN/A // as a normal response, it should go back to a master through 52510888Sandreas.hansson@arm.com // one of our slave ports, we also pay for any outstanding 52610888Sandreas.hansson@arm.com // header latency 52710888Sandreas.hansson@arm.com Tick latency = pkt->headerDelay; 52810888Sandreas.hansson@arm.com pkt->headerDelay = 0; 52910888Sandreas.hansson@arm.com slavePorts[dest_port_id]->schedTimingResp(pkt, curTick() + latency); 5309716SN/A 5319716SN/A respLayers[dest_port_id]->succeededTiming(packetFinishTime); 5323244SN/A } 5333244SN/A 53410656Sandreas.hansson@arm.com // remove the request from the routing table 53510656Sandreas.hansson@arm.com routeTo.erase(route_lookup); 53610656Sandreas.hansson@arm.com 5379712SN/A // stats updates 5389712SN/A transDist[pkt_cmd]++; 53910405Sandreas.hansson@arm.com snoops++; 5409712SN/A 5418948SN/A return true; 5428948SN/A} 5438948SN/A 5443210SN/A 5458948SN/Avoid 54610405Sandreas.hansson@arm.comCoherentXBar::forwardTiming(PacketPtr pkt, PortID exclude_slave_port_id, 54710888Sandreas.hansson@arm.com const std::vector<QueuedSlavePort*>& dests) 5488948SN/A{ 54910405Sandreas.hansson@arm.com DPRINTF(CoherentXBar, "%s for %s address %x size %d\n", __func__, 5509663SN/A pkt->cmdString(), pkt->getAddr(), pkt->getSize()); 5519663SN/A 5529524SN/A // snoops should only happen if the system isn't bypassing caches 5539524SN/A assert(!system->bypassCaches()); 5549524SN/A 55510401SN/A unsigned fanout = 0; 55610401SN/A 55710405Sandreas.hansson@arm.com for (const auto& p: dests) { 5588948SN/A // we could have gotten this request from a snooping master 5598948SN/A // (corresponding to our own slave port that is also in 5608948SN/A // snoopPorts) and should not send it back to where it came 5618948SN/A // from 5629031SN/A if (exclude_slave_port_id == InvalidPortID || 5638948SN/A p->getId() != exclude_slave_port_id) { 5648948SN/A // cache is not allowed to refuse snoop 5658975SN/A p->sendTimingSnoopReq(pkt); 56610401SN/A fanout++; 5678948SN/A } 5688948SN/A } 56910401SN/A 57010401SN/A // Stats for fanout of this forward operation 57110401SN/A snoopFanout.sample(fanout); 5722497SN/A} 5732497SN/A 5749092SN/Avoid 57510713Sandreas.hansson@arm.comCoherentXBar::recvReqRetry(PortID master_port_id) 5769092SN/A{ 5779093SN/A // responses and snoop responses never block on forwarding them, 5789093SN/A // so the retry will always be coming from a port to which we 5799093SN/A // tried to forward a request 5809715SN/A reqLayers[master_port_id]->recvRetry(); 5819092SN/A} 5829092SN/A 5839036SN/ATick 58410405Sandreas.hansson@arm.comCoherentXBar::recvAtomic(PacketPtr pkt, PortID slave_port_id) 5852657SN/A{ 58610405Sandreas.hansson@arm.com DPRINTF(CoherentXBar, "recvAtomic: packet src %s addr 0x%x cmd %s\n", 5879032SN/A slavePorts[slave_port_id]->name(), pkt->getAddr(), 5888949SN/A pkt->cmdString()); 5898915SN/A 59010405Sandreas.hansson@arm.com unsigned int pkt_size = pkt->hasData() ? pkt->getSize() : 0; 59110405Sandreas.hansson@arm.com unsigned int pkt_cmd = pkt->cmdToIndex(); 5929712SN/A 5938979SN/A MemCmd snoop_response_cmd = MemCmd::InvalidCmd; 5948979SN/A Tick snoop_response_latency = 0; 5958979SN/A 59610821Sandreas.hansson@arm.com if (!system->bypassCaches()) { 5978979SN/A // forward to all snoopers but the source 59810402SN/A std::pair<MemCmd, Tick> snoop_result; 59910402SN/A if (snoopFilter) { 60010402SN/A // check with the snoop filter where to forward this packet 60110402SN/A auto sf_res = 60210402SN/A snoopFilter->lookupRequest(pkt, *slavePorts[slave_port_id]); 60310402SN/A snoop_response_latency += sf_res.second * clockPeriod(); 60410405Sandreas.hansson@arm.com DPRINTF(CoherentXBar, "%s: src %s %s 0x%x"\ 60510402SN/A " SF size: %i lat: %i\n", __func__, 60610402SN/A slavePorts[slave_port_id]->name(), pkt->cmdString(), 60710402SN/A pkt->getAddr(), sf_res.first.size(), sf_res.second); 60811130Sali.jafri@arm.com 60911130Sali.jafri@arm.com // let the snoop filter know about the success of the send 61011130Sali.jafri@arm.com // operation, and do it even before sending it onwards to 61111130Sali.jafri@arm.com // avoid situations where atomic upward snoops sneak in 61211130Sali.jafri@arm.com // between and change the filter state 61311130Sali.jafri@arm.com snoopFilter->updateRequest(pkt, *slavePorts[slave_port_id], false); 61411130Sali.jafri@arm.com 61510402SN/A snoop_result = forwardAtomic(pkt, slave_port_id, InvalidPortID, 61610402SN/A sf_res.first); 61710402SN/A } else { 61810402SN/A snoop_result = forwardAtomic(pkt, slave_port_id); 61910402SN/A } 6208979SN/A snoop_response_cmd = snoop_result.first; 62110402SN/A snoop_response_latency += snoop_result.second; 6228979SN/A } 6238915SN/A 62411130Sali.jafri@arm.com // forwardAtomic snooped into peer caches of the sender, and if 62511130Sali.jafri@arm.com // this is a clean evict, but the packet is found in a cache, do 62611130Sali.jafri@arm.com // not forward it 62711130Sali.jafri@arm.com if (pkt->cmd == MemCmd::CleanEvict && pkt->isBlockCached()) { 62811130Sali.jafri@arm.com DPRINTF(CoherentXBar, "recvAtomic: Clean evict 0x%x still cached, " 62911130Sali.jafri@arm.com "not forwarding\n", pkt->getAddr()); 63011130Sali.jafri@arm.com return 0; 63111130Sali.jafri@arm.com } 63211130Sali.jafri@arm.com 6338948SN/A // even if we had a snoop response, we must continue and also 6348948SN/A // perform the actual request at the destination 63510405Sandreas.hansson@arm.com PortID master_port_id = findPort(pkt->getAddr()); 63610405Sandreas.hansson@arm.com 63710405Sandreas.hansson@arm.com // stats updates for the request 63810405Sandreas.hansson@arm.com pktCount[slave_port_id][master_port_id]++; 63910405Sandreas.hansson@arm.com pktSize[slave_port_id][master_port_id] += pkt_size; 64010405Sandreas.hansson@arm.com transDist[pkt_cmd]++; 6418948SN/A 6428948SN/A // forward the request to the appropriate destination 64310405Sandreas.hansson@arm.com Tick response_latency = masterPorts[master_port_id]->sendAtomic(pkt); 6448948SN/A 64511130Sali.jafri@arm.com // if lower levels have replied, tell the snoop filter 64611130Sali.jafri@arm.com if (!system->bypassCaches() && snoopFilter && pkt->isResponse()) { 64710402SN/A snoopFilter->updateResponse(pkt, *slavePorts[slave_port_id]); 64810402SN/A } 64910402SN/A 6508948SN/A // if we got a response from a snooper, restore it here 6518948SN/A if (snoop_response_cmd != MemCmd::InvalidCmd) { 6528948SN/A // no one else should have responded 6538948SN/A assert(!pkt->isResponse()); 6548948SN/A pkt->cmd = snoop_response_cmd; 6558948SN/A response_latency = snoop_response_latency; 6568948SN/A } 6578948SN/A 6589712SN/A // add the response data 65910405Sandreas.hansson@arm.com if (pkt->isResponse()) { 66010405Sandreas.hansson@arm.com pkt_size = pkt->hasData() ? pkt->getSize() : 0; 66110405Sandreas.hansson@arm.com pkt_cmd = pkt->cmdToIndex(); 66210405Sandreas.hansson@arm.com 66310405Sandreas.hansson@arm.com // stats updates 66410405Sandreas.hansson@arm.com pktCount[slave_port_id][master_port_id]++; 66510405Sandreas.hansson@arm.com pktSize[slave_port_id][master_port_id] += pkt_size; 66610405Sandreas.hansson@arm.com transDist[pkt_cmd]++; 66710405Sandreas.hansson@arm.com } 6689712SN/A 66910694SMarco.Balboni@ARM.com // @todo: Not setting header time 67010694SMarco.Balboni@ARM.com pkt->payloadDelay = response_latency; 6718948SN/A return response_latency; 6728948SN/A} 6738948SN/A 6748948SN/ATick 67510405Sandreas.hansson@arm.comCoherentXBar::recvAtomicSnoop(PacketPtr pkt, PortID master_port_id) 6768948SN/A{ 67710405Sandreas.hansson@arm.com DPRINTF(CoherentXBar, "recvAtomicSnoop: packet src %s addr 0x%x cmd %s\n", 6789032SN/A masterPorts[master_port_id]->name(), pkt->getAddr(), 6798949SN/A pkt->cmdString()); 6808948SN/A 6819712SN/A // add the request snoop data 68210405Sandreas.hansson@arm.com snoops++; 6839712SN/A 6848948SN/A // forward to all snoopers 68510402SN/A std::pair<MemCmd, Tick> snoop_result; 68610402SN/A Tick snoop_response_latency = 0; 68710402SN/A if (snoopFilter) { 68810402SN/A auto sf_res = snoopFilter->lookupSnoop(pkt); 68910402SN/A snoop_response_latency += sf_res.second * clockPeriod(); 69010405Sandreas.hansson@arm.com DPRINTF(CoherentXBar, "%s: src %s %s 0x%x SF size: %i lat: %i\n", 69110402SN/A __func__, masterPorts[master_port_id]->name(), pkt->cmdString(), 69210402SN/A pkt->getAddr(), sf_res.first.size(), sf_res.second); 69310402SN/A snoop_result = forwardAtomic(pkt, InvalidPortID, master_port_id, 69410402SN/A sf_res.first); 69510402SN/A } else { 69610402SN/A snoop_result = forwardAtomic(pkt, InvalidPortID); 69710402SN/A } 6988948SN/A MemCmd snoop_response_cmd = snoop_result.first; 69910402SN/A snoop_response_latency += snoop_result.second; 7008948SN/A 7018948SN/A if (snoop_response_cmd != MemCmd::InvalidCmd) 7028948SN/A pkt->cmd = snoop_response_cmd; 7038948SN/A 7049712SN/A // add the response snoop data 70510401SN/A if (pkt->isResponse()) { 70610405Sandreas.hansson@arm.com snoops++; 70710401SN/A } 7089712SN/A 70910694SMarco.Balboni@ARM.com // @todo: Not setting header time 71010694SMarco.Balboni@ARM.com pkt->payloadDelay = snoop_response_latency; 7118948SN/A return snoop_response_latency; 7128948SN/A} 7138948SN/A 7148948SN/Astd::pair<MemCmd, Tick> 71510405Sandreas.hansson@arm.comCoherentXBar::forwardAtomic(PacketPtr pkt, PortID exclude_slave_port_id, 71610402SN/A PortID source_master_port_id, 71710888Sandreas.hansson@arm.com const std::vector<QueuedSlavePort*>& dests) 7188948SN/A{ 7199032SN/A // the packet may be changed on snoops, record the original 7209032SN/A // command to enable us to restore it between snoops so that 7218948SN/A // additional snoops can take place properly 7224626SN/A MemCmd orig_cmd = pkt->cmd; 7234879SN/A MemCmd snoop_response_cmd = MemCmd::InvalidCmd; 7244879SN/A Tick snoop_response_latency = 0; 7253662SN/A 7269524SN/A // snoops should only happen if the system isn't bypassing caches 7279524SN/A assert(!system->bypassCaches()); 7289524SN/A 72910401SN/A unsigned fanout = 0; 73010401SN/A 73110405Sandreas.hansson@arm.com for (const auto& p: dests) { 7328915SN/A // we could have gotten this request from a snooping master 7338915SN/A // (corresponding to our own slave port that is also in 7348915SN/A // snoopPorts) and should not send it back to where it came 7358915SN/A // from 73610402SN/A if (exclude_slave_port_id != InvalidPortID && 73710402SN/A p->getId() == exclude_slave_port_id) 73810402SN/A continue; 73910401SN/A 74010402SN/A Tick latency = p->sendAtomicSnoop(pkt); 74110402SN/A fanout++; 74210402SN/A 74310402SN/A // in contrast to a functional access, we have to keep on 74410402SN/A // going as all snoopers must be updated even if we get a 74510402SN/A // response 74610402SN/A if (!pkt->isResponse()) 74710402SN/A continue; 74810402SN/A 74910402SN/A // response from snoop agent 75010402SN/A assert(pkt->cmd != orig_cmd); 75110402SN/A assert(pkt->memInhibitAsserted()); 75210402SN/A // should only happen once 75310402SN/A assert(snoop_response_cmd == MemCmd::InvalidCmd); 75410402SN/A // save response state 75510402SN/A snoop_response_cmd = pkt->cmd; 75610402SN/A snoop_response_latency = latency; 75710402SN/A 75810402SN/A if (snoopFilter) { 75910402SN/A // Handle responses by the snoopers and differentiate between 76010402SN/A // responses to requests from above and snoops from below 76110402SN/A if (source_master_port_id != InvalidPortID) { 76210402SN/A // Getting a response for a snoop from below 76310402SN/A assert(exclude_slave_port_id == InvalidPortID); 76410402SN/A snoopFilter->updateSnoopForward(pkt, *p, 76510402SN/A *masterPorts[source_master_port_id]); 76610402SN/A } else { 76710402SN/A // Getting a response for a request from above 76810402SN/A assert(source_master_port_id == InvalidPortID); 76910402SN/A snoopFilter->updateSnoopResponse(pkt, *p, 77010402SN/A *slavePorts[exclude_slave_port_id]); 7714626SN/A } 7724626SN/A } 77310402SN/A // restore original packet state for remaining snoopers 77410402SN/A pkt->cmd = orig_cmd; 7754626SN/A } 7764626SN/A 77710401SN/A // Stats for fanout 77810401SN/A snoopFanout.sample(fanout); 77910401SN/A 7808948SN/A // the packet is restored as part of the loop and any potential 7818948SN/A // snoop response is part of the returned pair 7828948SN/A return std::make_pair(snoop_response_cmd, snoop_response_latency); 7832497SN/A} 7842497SN/A 7852497SN/Avoid 78610405Sandreas.hansson@arm.comCoherentXBar::recvFunctional(PacketPtr pkt, PortID slave_port_id) 7872497SN/A{ 7888663SN/A if (!pkt->isPrint()) { 7898663SN/A // don't do DPRINTFs on PrintReq as it clutters up the output 79010405Sandreas.hansson@arm.com DPRINTF(CoherentXBar, 7918949SN/A "recvFunctional: packet src %s addr 0x%x cmd %s\n", 7929032SN/A slavePorts[slave_port_id]->name(), pkt->getAddr(), 7938663SN/A pkt->cmdString()); 7948663SN/A } 7958663SN/A 79610821Sandreas.hansson@arm.com if (!system->bypassCaches()) { 7978979SN/A // forward to all snoopers but the source 7989032SN/A forwardFunctional(pkt, slave_port_id); 7998979SN/A } 8004912SN/A 8018948SN/A // there is no need to continue if the snooping has found what we 8028948SN/A // were looking for and the packet is already a response 8038948SN/A if (!pkt->isResponse()) { 80410888Sandreas.hansson@arm.com // since our slave ports are queued ports we need to check them as well 80510888Sandreas.hansson@arm.com for (const auto& p : slavePorts) { 80610888Sandreas.hansson@arm.com // if we find a response that has the data, then the 80710888Sandreas.hansson@arm.com // downstream caches/memories may be out of date, so simply stop 80810888Sandreas.hansson@arm.com // here 80910888Sandreas.hansson@arm.com if (p->checkFunctional(pkt)) { 81010888Sandreas.hansson@arm.com if (pkt->needsResponse()) 81110888Sandreas.hansson@arm.com pkt->makeResponse(); 81210888Sandreas.hansson@arm.com return; 81310888Sandreas.hansson@arm.com } 81410888Sandreas.hansson@arm.com } 81510888Sandreas.hansson@arm.com 8169031SN/A PortID dest_id = findPort(pkt->getAddr()); 8178948SN/A 8188948SN/A masterPorts[dest_id]->sendFunctional(pkt); 8198948SN/A } 8208948SN/A} 8218948SN/A 8228948SN/Avoid 82310405Sandreas.hansson@arm.comCoherentXBar::recvFunctionalSnoop(PacketPtr pkt, PortID master_port_id) 8248948SN/A{ 8258948SN/A if (!pkt->isPrint()) { 8268948SN/A // don't do DPRINTFs on PrintReq as it clutters up the output 82710405Sandreas.hansson@arm.com DPRINTF(CoherentXBar, 8288949SN/A "recvFunctionalSnoop: packet src %s addr 0x%x cmd %s\n", 8299032SN/A masterPorts[master_port_id]->name(), pkt->getAddr(), 8308948SN/A pkt->cmdString()); 8318948SN/A } 8328948SN/A 8338948SN/A // forward to all snoopers 8349031SN/A forwardFunctional(pkt, InvalidPortID); 8358948SN/A} 8368948SN/A 8378948SN/Avoid 83810405Sandreas.hansson@arm.comCoherentXBar::forwardFunctional(PacketPtr pkt, PortID exclude_slave_port_id) 8398948SN/A{ 8409524SN/A // snoops should only happen if the system isn't bypassing caches 8419524SN/A assert(!system->bypassCaches()); 8429524SN/A 84310405Sandreas.hansson@arm.com for (const auto& p: snoopPorts) { 8448915SN/A // we could have gotten this request from a snooping master 8458915SN/A // (corresponding to our own slave port that is also in 8468915SN/A // snoopPorts) and should not send it back to where it came 8478915SN/A // from 8489031SN/A if (exclude_slave_port_id == InvalidPortID || 8498948SN/A p->getId() != exclude_slave_port_id) 8508948SN/A p->sendFunctionalSnoop(pkt); 8518915SN/A 8528948SN/A // if we get a response we are done 8538948SN/A if (pkt->isResponse()) { 8548948SN/A break; 8558915SN/A } 8563650SN/A } 8572497SN/A} 8582497SN/A 8599712SN/Avoid 86010405Sandreas.hansson@arm.comCoherentXBar::regStats() 8619712SN/A{ 86210405Sandreas.hansson@arm.com // register the stats of the base class and our layers 86310405Sandreas.hansson@arm.com BaseXBar::regStats(); 86410405Sandreas.hansson@arm.com for (auto l: reqLayers) 86510405Sandreas.hansson@arm.com l->regStats(); 86610405Sandreas.hansson@arm.com for (auto l: respLayers) 86710405Sandreas.hansson@arm.com l->regStats(); 86810405Sandreas.hansson@arm.com for (auto l: snoopLayers) 86910405Sandreas.hansson@arm.com l->regStats(); 8709712SN/A 87110405Sandreas.hansson@arm.com snoops 87210405Sandreas.hansson@arm.com .name(name() + ".snoops") 87310401SN/A .desc("Total snoops (count)") 87410401SN/A ; 87510401SN/A 87610401SN/A snoopFanout 87710401SN/A .init(0, snoopPorts.size(), 1) 87810401SN/A .name(name() + ".snoop_fanout") 87910401SN/A .desc("Request fanout histogram") 88010401SN/A ; 8819712SN/A} 8829712SN/A 88310405Sandreas.hansson@arm.comCoherentXBar * 88410405Sandreas.hansson@arm.comCoherentXBarParams::create() 8852497SN/A{ 88610405Sandreas.hansson@arm.com return new CoherentXBar(this); 8872497SN/A} 888