base.cc revision 10052
12810SN/A/* 29546Sandreas.hansson@arm.com * Copyright (c) 2013 ARM Limited 39546Sandreas.hansson@arm.com * All rights reserved. 49546Sandreas.hansson@arm.com * 59546Sandreas.hansson@arm.com * The license below extends only to copyright in the software and shall 69546Sandreas.hansson@arm.com * not be construed as granting a license to any other intellectual 79546Sandreas.hansson@arm.com * property including but not limited to intellectual property relating 89546Sandreas.hansson@arm.com * to a hardware implementation of the functionality of the software 99546Sandreas.hansson@arm.com * licensed hereunder. You may use the software subject to the license 109546Sandreas.hansson@arm.com * terms below provided that you ensure that this notice is replicated 119546Sandreas.hansson@arm.com * unmodified and in its entirety in all distributions of the software, 129546Sandreas.hansson@arm.com * modified or unmodified, in source code or in binary form. 139546Sandreas.hansson@arm.com * 142810SN/A * Copyright (c) 2005 The Regents of The University of Michigan 152810SN/A * All rights reserved. 162810SN/A * 172810SN/A * Redistribution and use in source and binary forms, with or without 182810SN/A * modification, are permitted provided that the following conditions are 192810SN/A * met: redistributions of source code must retain the above copyright 202810SN/A * notice, this list of conditions and the following disclaimer; 212810SN/A * redistributions in binary form must reproduce the above copyright 222810SN/A * notice, this list of conditions and the following disclaimer in the 232810SN/A * documentation and/or other materials provided with the distribution; 242810SN/A * neither the name of the copyright holders nor the names of its 252810SN/A * contributors may be used to endorse or promote products derived from 262810SN/A * this software without specific prior written permission. 272810SN/A * 282810SN/A * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 292810SN/A * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 302810SN/A * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 312810SN/A * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 322810SN/A * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 332810SN/A * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 342810SN/A * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 352810SN/A * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 362810SN/A * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 372810SN/A * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 382810SN/A * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 392810SN/A * 402810SN/A * Authors: Ron Dreslinski 412810SN/A */ 422810SN/A 432810SN/A/** 442810SN/A * @file 452810SN/A * Hardware Prefetcher Definition. 462810SN/A */ 472810SN/A 486658Snate@binkert.org#include <list> 496658Snate@binkert.org 505875Ssteve.reinhardt@amd.com#include "arch/isa_traits.hh" 512810SN/A#include "base/trace.hh" 526658Snate@binkert.org#include "config/the_isa.hh" 538232Snate@binkert.org#include "debug/HWPrefetch.hh" 548229Snate@binkert.org#include "mem/cache/prefetch/base.hh" 555338Sstever@gmail.com#include "mem/cache/base.hh" 562814SN/A#include "mem/request.hh" 578832SAli.Saidi@ARM.com#include "sim/system.hh" 582810SN/A 598831Smrinmoy.ghosh@arm.comBasePrefetcher::BasePrefetcher(const Params *p) 609288Sandreas.hansson@arm.com : ClockedObject(p), size(p->size), latency(p->latency), degree(p->degree), 618832SAli.Saidi@ARM.com useMasterId(p->use_master_id), pageStop(!p->cross_pages), 628832SAli.Saidi@ARM.com serialSquash(p->serial_squash), onlyData(p->data_accesses_only), 6310052Smitch.hayenga+gem5@gmail.com onMissOnly(p->on_miss_only), onReadOnly(p->on_read_only), 6410052Smitch.hayenga+gem5@gmail.com onPrefetch(p->on_prefetch), system(p->sys), 6510052Smitch.hayenga+gem5@gmail.com masterId(system->getMasterId(name())) 662810SN/A{ 672810SN/A} 682810SN/A 692810SN/Avoid 702810SN/ABasePrefetcher::setCache(BaseCache *_cache) 712810SN/A{ 722810SN/A cache = _cache; 732810SN/A blkSize = cache->getBlockSize(); 742810SN/A} 752810SN/A 762810SN/Avoid 778831Smrinmoy.ghosh@arm.comBasePrefetcher::regStats() 782810SN/A{ 792810SN/A pfIdentified 808831Smrinmoy.ghosh@arm.com .name(name() + ".prefetcher.num_hwpf_identified") 812810SN/A .desc("number of hwpf identified") 822810SN/A ; 832810SN/A 842810SN/A pfMSHRHit 858831Smrinmoy.ghosh@arm.com .name(name() + ".prefetcher.num_hwpf_already_in_mshr") 862810SN/A .desc("number of hwpf that were already in mshr") 872810SN/A ; 882810SN/A 892810SN/A pfCacheHit 908831Smrinmoy.ghosh@arm.com .name(name() + ".prefetcher.num_hwpf_already_in_cache") 912810SN/A .desc("number of hwpf that were already in the cache") 922810SN/A ; 932810SN/A 942810SN/A pfBufferHit 958831Smrinmoy.ghosh@arm.com .name(name() + ".prefetcher.num_hwpf_already_in_prefetcher") 962810SN/A .desc("number of hwpf that were already in the prefetch queue") 972810SN/A ; 982810SN/A 992810SN/A pfRemovedFull 1008831Smrinmoy.ghosh@arm.com .name(name() + ".prefetcher.num_hwpf_evicted") 1012810SN/A .desc("number of hwpf removed due to no buffer left") 1022810SN/A ; 1032810SN/A 1042810SN/A pfRemovedMSHR 1058831Smrinmoy.ghosh@arm.com .name(name() + ".prefetcher.num_hwpf_removed_MSHR_hit") 1062810SN/A .desc("number of hwpf removed because MSHR allocated") 1072810SN/A ; 1082810SN/A 1092810SN/A pfIssued 1108831Smrinmoy.ghosh@arm.com .name(name() + ".prefetcher.num_hwpf_issued") 1112810SN/A .desc("number of hwpf issued") 1122810SN/A ; 1132810SN/A 1142810SN/A pfSpanPage 1158831Smrinmoy.ghosh@arm.com .name(name() + ".prefetcher.num_hwpf_span_page") 1162810SN/A .desc("number of hwpf spanning a virtual page") 1172810SN/A ; 1182810SN/A 1192810SN/A pfSquashed 1208831Smrinmoy.ghosh@arm.com .name(name() + ".prefetcher.num_hwpf_squashed_from_miss") 1215875Ssteve.reinhardt@amd.com .desc("number of hwpf that got squashed due to a miss " 1225875Ssteve.reinhardt@amd.com "aborting calculation time") 1232810SN/A ; 1242810SN/A} 1252810SN/A 1263861SN/Ainline bool 12710028SGiacomo.Gabrielli@arm.comBasePrefetcher::inCache(Addr addr, bool is_secure) 1283861SN/A{ 12910028SGiacomo.Gabrielli@arm.com if (cache->inCache(addr, is_secure)) { 1303861SN/A pfCacheHit++; 1313861SN/A return true; 1323861SN/A } 1333861SN/A return false; 1343861SN/A} 1353861SN/A 1363861SN/Ainline bool 13710028SGiacomo.Gabrielli@arm.comBasePrefetcher::inMissQueue(Addr addr, bool is_secure) 1383861SN/A{ 13910028SGiacomo.Gabrielli@arm.com if (cache->inMissQueue(addr, is_secure)) { 1403861SN/A pfMSHRHit++; 1413861SN/A return true; 1423861SN/A } 1433861SN/A return false; 1443861SN/A} 1453861SN/A 1463349SN/APacketPtr 1472810SN/ABasePrefetcher::getPacket() 1482810SN/A{ 1495875Ssteve.reinhardt@amd.com DPRINTF(HWPrefetch, "Requesting a hw_pf to issue\n"); 1502810SN/A 1512810SN/A if (pf.empty()) { 1525875Ssteve.reinhardt@amd.com DPRINTF(HWPrefetch, "No HW_PF found\n"); 1532810SN/A return NULL; 1542810SN/A } 1552810SN/A 1569546Sandreas.hansson@arm.com PacketPtr pkt = pf.begin()->pkt; 1578509SAli.Saidi@ARM.com while (!pf.empty()) { 1589546Sandreas.hansson@arm.com pkt = pf.begin()->pkt; 1592810SN/A pf.pop_front(); 1605875Ssteve.reinhardt@amd.com 1618509SAli.Saidi@ARM.com Addr blk_addr = pkt->getAddr() & ~(Addr)(blkSize-1); 16210028SGiacomo.Gabrielli@arm.com bool is_secure = pkt->isSecure(); 1638509SAli.Saidi@ARM.com 16410028SGiacomo.Gabrielli@arm.com if (!inCache(blk_addr, is_secure) && !inMissQueue(blk_addr, is_secure)) 1658509SAli.Saidi@ARM.com // we found a prefetch, return it 1668509SAli.Saidi@ARM.com break; 1678509SAli.Saidi@ARM.com 16810028SGiacomo.Gabrielli@arm.com DPRINTF(HWPrefetch, "addr 0x%x (%s) in cache, skipping\n", 16910028SGiacomo.Gabrielli@arm.com pkt->getAddr(), is_secure ? "s" : "ns"); 1708509SAli.Saidi@ARM.com delete pkt->req; 1718509SAli.Saidi@ARM.com delete pkt; 1725875Ssteve.reinhardt@amd.com 1732810SN/A if (pf.empty()) { 1744628SN/A cache->deassertMemSideBusRequest(BaseCache::Request_PF); 1758509SAli.Saidi@ARM.com return NULL; // None left, all were in cache 1762810SN/A } 1778509SAli.Saidi@ARM.com } 1782810SN/A 1792810SN/A pfIssued++; 1805875Ssteve.reinhardt@amd.com assert(pkt != NULL); 18110028SGiacomo.Gabrielli@arm.com DPRINTF(HWPrefetch, "returning 0x%x (%s)\n", pkt->getAddr(), 18210028SGiacomo.Gabrielli@arm.com pkt->isSecure() ? "s" : "ns"); 1832810SN/A return pkt; 1842810SN/A} 1852810SN/A 1865875Ssteve.reinhardt@amd.com 1875875Ssteve.reinhardt@amd.comTick 1889546Sandreas.hansson@arm.comBasePrefetcher::notify(PacketPtr &pkt, Tick tick) 1892810SN/A{ 19010052Smitch.hayenga+gem5@gmail.com // Don't consult the prefetcher if any of the following conditons are true 19110052Smitch.hayenga+gem5@gmail.com // 1) The request is uncacheable 19210052Smitch.hayenga+gem5@gmail.com // 2) The request is a fetch, but we are only prefeching data 19310052Smitch.hayenga+gem5@gmail.com // 3) The request is a cache hit, but we are only training on misses 19410052Smitch.hayenga+gem5@gmail.com // 4) THe request is a write, but we are only training on reads 19510052Smitch.hayenga+gem5@gmail.com if (!pkt->req->isUncacheable() && !(pkt->req->isInstFetch() && onlyData) && 19610052Smitch.hayenga+gem5@gmail.com !(onMissOnly && inCache(pkt->getAddr(), true)) && 19710052Smitch.hayenga+gem5@gmail.com !(onReadOnly && !pkt->isRead())) { 1985875Ssteve.reinhardt@amd.com // Calculate the blk address 1995875Ssteve.reinhardt@amd.com Addr blk_addr = pkt->getAddr() & ~(Addr)(blkSize-1); 20010028SGiacomo.Gabrielli@arm.com bool is_secure = pkt->isSecure(); 2012810SN/A 2025875Ssteve.reinhardt@amd.com // Check if miss is in pfq, if so remove it 20310028SGiacomo.Gabrielli@arm.com std::list<DeferredPacket>::iterator iter = inPrefetch(blk_addr, 20410028SGiacomo.Gabrielli@arm.com is_secure); 2052810SN/A if (iter != pf.end()) { 2065875Ssteve.reinhardt@amd.com DPRINTF(HWPrefetch, "Saw a miss to a queued prefetch addr: " 20710028SGiacomo.Gabrielli@arm.com "0x%x (%s), removing it\n", blk_addr, 20810028SGiacomo.Gabrielli@arm.com is_secure ? "s" : "ns"); 2092810SN/A pfRemovedMSHR++; 2109546Sandreas.hansson@arm.com delete iter->pkt->req; 2119546Sandreas.hansson@arm.com delete iter->pkt; 2128991SAli.Saidi@ARM.com iter = pf.erase(iter); 2132810SN/A if (pf.empty()) 2144628SN/A cache->deassertMemSideBusRequest(BaseCache::Request_PF); 2152810SN/A } 2162810SN/A 2175875Ssteve.reinhardt@amd.com // Remove anything in queue with delay older than time 2185875Ssteve.reinhardt@amd.com // since everything is inserted in time order, start from end 2195875Ssteve.reinhardt@amd.com // and work until pf.empty() or time is earlier 2205875Ssteve.reinhardt@amd.com // This is done to emulate Aborting the previous work on a new miss 2215875Ssteve.reinhardt@amd.com // Needed for serial calculators like GHB 2222810SN/A if (serialSquash) { 2232810SN/A iter = pf.end(); 2248991SAli.Saidi@ARM.com if (iter != pf.begin()) 2258991SAli.Saidi@ARM.com iter--; 2269546Sandreas.hansson@arm.com while (!pf.empty() && iter->tick >= tick) { 2272810SN/A pfSquashed++; 2285875Ssteve.reinhardt@amd.com DPRINTF(HWPrefetch, "Squashing old prefetch addr: 0x%x\n", 2299546Sandreas.hansson@arm.com iter->pkt->getAddr()); 2309546Sandreas.hansson@arm.com delete iter->pkt->req; 2319546Sandreas.hansson@arm.com delete iter->pkt; 2328991SAli.Saidi@ARM.com iter = pf.erase(iter); 2338991SAli.Saidi@ARM.com if (iter != pf.begin()) 2348991SAli.Saidi@ARM.com iter--; 2352810SN/A } 2362810SN/A if (pf.empty()) 2374628SN/A cache->deassertMemSideBusRequest(BaseCache::Request_PF); 2382810SN/A } 2392810SN/A 2402810SN/A 2412810SN/A std::list<Addr> addresses; 2429288Sandreas.hansson@arm.com std::list<Cycles> delays; 2432810SN/A calculatePrefetch(pkt, addresses, delays); 2442810SN/A 2455875Ssteve.reinhardt@amd.com std::list<Addr>::iterator addrIter = addresses.begin(); 2469288Sandreas.hansson@arm.com std::list<Cycles>::iterator delayIter = delays.begin(); 2475875Ssteve.reinhardt@amd.com for (; addrIter != addresses.end(); ++addrIter, ++delayIter) { 2485875Ssteve.reinhardt@amd.com Addr addr = *addrIter; 2495875Ssteve.reinhardt@amd.com 2502810SN/A pfIdentified++; 2515875Ssteve.reinhardt@amd.com 2525875Ssteve.reinhardt@amd.com DPRINTF(HWPrefetch, "Found a pf candidate addr: 0x%x, " 2535875Ssteve.reinhardt@amd.com "inserting into prefetch queue with delay %d time %d\n", 2545875Ssteve.reinhardt@amd.com addr, *delayIter, time); 2555875Ssteve.reinhardt@amd.com 2565875Ssteve.reinhardt@amd.com // Check if it is already in the pf buffer 25710028SGiacomo.Gabrielli@arm.com if (inPrefetch(addr, is_secure) != pf.end()) { 2585875Ssteve.reinhardt@amd.com pfBufferHit++; 2595875Ssteve.reinhardt@amd.com DPRINTF(HWPrefetch, "Prefetch addr already in pf buffer\n"); 2605875Ssteve.reinhardt@amd.com continue; 2615875Ssteve.reinhardt@amd.com } 2625875Ssteve.reinhardt@amd.com 2635875Ssteve.reinhardt@amd.com // create a prefetch memreq 2648832SAli.Saidi@ARM.com Request *prefetchReq = new Request(*addrIter, blkSize, 0, masterId); 26510028SGiacomo.Gabrielli@arm.com if (is_secure) 26610028SGiacomo.Gabrielli@arm.com prefetchReq->setFlags(Request::SECURE); 26710024Sdam.sunwoo@arm.com prefetchReq->taskId(ContextSwitchTaskId::Prefetcher); 2685875Ssteve.reinhardt@amd.com PacketPtr prefetch = 2698949Sandreas.hansson@arm.com new Packet(prefetchReq, MemCmd::HardPFReq); 2702825SN/A prefetch->allocate(); 2715714Shsul@eecs.umich.edu prefetch->req->setThreadContext(pkt->req->contextId(), 2725714Shsul@eecs.umich.edu pkt->req->threadId()); 2732814SN/A 27410052Smitch.hayenga+gem5@gmail.com // Tag orefetch reqeuests with corresponding PC to train lower 27510052Smitch.hayenga+gem5@gmail.com // cache-level prefetchers 27610052Smitch.hayenga+gem5@gmail.com if (onPrefetch && pkt->req->hasPC()) 27710052Smitch.hayenga+gem5@gmail.com prefetch->req->setPC(pkt->req->getPC()); 27810052Smitch.hayenga+gem5@gmail.com 2795875Ssteve.reinhardt@amd.com // We just remove the head if we are full 2805875Ssteve.reinhardt@amd.com if (pf.size() == size) { 2812810SN/A pfRemovedFull++; 2829546Sandreas.hansson@arm.com PacketPtr old_pkt = pf.begin()->pkt; 2835875Ssteve.reinhardt@amd.com DPRINTF(HWPrefetch, "Prefetch queue full, " 2845875Ssteve.reinhardt@amd.com "removing oldest 0x%x\n", old_pkt->getAddr()); 2855875Ssteve.reinhardt@amd.com delete old_pkt->req; 2865875Ssteve.reinhardt@amd.com delete old_pkt; 2872810SN/A pf.pop_front(); 2882810SN/A } 2892810SN/A 2909546Sandreas.hansson@arm.com pf.push_back(DeferredPacket(tick + clockPeriod() * *delayIter, 2919546Sandreas.hansson@arm.com prefetch)); 2922810SN/A } 2932810SN/A } 2945875Ssteve.reinhardt@amd.com 2959546Sandreas.hansson@arm.com return pf.empty() ? 0 : pf.front().tick; 2962810SN/A} 2972810SN/A 2989546Sandreas.hansson@arm.comstd::list<BasePrefetcher::DeferredPacket>::iterator 29910028SGiacomo.Gabrielli@arm.comBasePrefetcher::inPrefetch(Addr address, bool is_secure) 3002810SN/A{ 3015875Ssteve.reinhardt@amd.com // Guaranteed to only be one match, we always check before inserting 3029546Sandreas.hansson@arm.com std::list<DeferredPacket>::iterator iter; 3035875Ssteve.reinhardt@amd.com for (iter = pf.begin(); iter != pf.end(); iter++) { 30410028SGiacomo.Gabrielli@arm.com if (((*iter).pkt->getAddr() & ~(Addr)(blkSize-1)) == address && 30510028SGiacomo.Gabrielli@arm.com (*iter).pkt->isSecure() == is_secure) { 3062810SN/A return iter; 3072810SN/A } 3082810SN/A } 3092810SN/A return pf.end(); 3102810SN/A} 3112810SN/A 3125875Ssteve.reinhardt@amd.combool 3135875Ssteve.reinhardt@amd.comBasePrefetcher::samePage(Addr a, Addr b) 3145875Ssteve.reinhardt@amd.com{ 3155875Ssteve.reinhardt@amd.com return roundDown(a, TheISA::VMPageSize) == roundDown(b, TheISA::VMPageSize); 3165875Ssteve.reinhardt@amd.com} 3178831Smrinmoy.ghosh@arm.com 3188831Smrinmoy.ghosh@arm.com 319