cache.cc revision 11558
12810Srdreslin@umich.edu/* 211375Sandreas.hansson@arm.com * Copyright (c) 2010-2016 ARM Limited 311051Sandreas.hansson@arm.com * All rights reserved. 411051Sandreas.hansson@arm.com * 511051Sandreas.hansson@arm.com * The license below extends only to copyright in the software and shall 611051Sandreas.hansson@arm.com * not be construed as granting a license to any other intellectual 711051Sandreas.hansson@arm.com * property including but not limited to intellectual property relating 811051Sandreas.hansson@arm.com * to a hardware implementation of the functionality of the software 911051Sandreas.hansson@arm.com * licensed hereunder. You may use the software subject to the license 1011051Sandreas.hansson@arm.com * terms below provided that you ensure that this notice is replicated 1111051Sandreas.hansson@arm.com * unmodified and in its entirety in all distributions of the software, 1211051Sandreas.hansson@arm.com * modified or unmodified, in source code or in binary form. 1311051Sandreas.hansson@arm.com * 1411051Sandreas.hansson@arm.com * Copyright (c) 2002-2005 The Regents of The University of Michigan 1511051Sandreas.hansson@arm.com * Copyright (c) 2010,2015 Advanced Micro Devices, Inc. 162810Srdreslin@umich.edu * All rights reserved. 172810Srdreslin@umich.edu * 182810Srdreslin@umich.edu * Redistribution and use in source and binary forms, with or without 192810Srdreslin@umich.edu * modification, are permitted provided that the following conditions are 202810Srdreslin@umich.edu * met: redistributions of source code must retain the above copyright 212810Srdreslin@umich.edu * notice, this list of conditions and the following disclaimer; 222810Srdreslin@umich.edu * redistributions in binary form must reproduce the above copyright 232810Srdreslin@umich.edu * notice, this list of conditions and the following disclaimer in the 242810Srdreslin@umich.edu * documentation and/or other materials provided with the distribution; 252810Srdreslin@umich.edu * neither the name of the copyright holders nor the names of its 262810Srdreslin@umich.edu * contributors may be used to endorse or promote products derived from 272810Srdreslin@umich.edu * this software without specific prior written permission. 282810Srdreslin@umich.edu * 292810Srdreslin@umich.edu * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 302810Srdreslin@umich.edu * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 312810Srdreslin@umich.edu * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 322810Srdreslin@umich.edu * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 332810Srdreslin@umich.edu * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 342810Srdreslin@umich.edu * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 352810Srdreslin@umich.edu * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 362810Srdreslin@umich.edu * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 372810Srdreslin@umich.edu * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 382810Srdreslin@umich.edu * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 392810Srdreslin@umich.edu * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 402810Srdreslin@umich.edu * 412810Srdreslin@umich.edu * Authors: Erik Hallnor 4211051Sandreas.hansson@arm.com * Dave Greene 4311051Sandreas.hansson@arm.com * Nathan Binkert 442810Srdreslin@umich.edu * Steve Reinhardt 4511051Sandreas.hansson@arm.com * Ron Dreslinski 4611051Sandreas.hansson@arm.com * Andreas Sandberg 472810Srdreslin@umich.edu */ 482810Srdreslin@umich.edu 492810Srdreslin@umich.edu/** 502810Srdreslin@umich.edu * @file 5111051Sandreas.hansson@arm.com * Cache definitions. 522810Srdreslin@umich.edu */ 532810Srdreslin@umich.edu 5411051Sandreas.hansson@arm.com#include "mem/cache/cache.hh" 552810Srdreslin@umich.edu 5611051Sandreas.hansson@arm.com#include "base/misc.hh" 5711051Sandreas.hansson@arm.com#include "base/types.hh" 5811051Sandreas.hansson@arm.com#include "debug/Cache.hh" 5911051Sandreas.hansson@arm.com#include "debug/CachePort.hh" 6011051Sandreas.hansson@arm.com#include "debug/CacheTags.hh" 6111288Ssteve.reinhardt@amd.com#include "debug/CacheVerbose.hh" 6211051Sandreas.hansson@arm.com#include "mem/cache/blk.hh" 6311051Sandreas.hansson@arm.com#include "mem/cache/mshr.hh" 6411051Sandreas.hansson@arm.com#include "mem/cache/prefetch/base.hh" 6511051Sandreas.hansson@arm.com#include "sim/sim_exit.hh" 6611051Sandreas.hansson@arm.com 6711053Sandreas.hansson@arm.comCache::Cache(const CacheParams *p) 6811053Sandreas.hansson@arm.com : BaseCache(p, p->system->cacheLineSize()), 6911051Sandreas.hansson@arm.com tags(p->tags), 7011051Sandreas.hansson@arm.com prefetcher(p->prefetcher), 7111051Sandreas.hansson@arm.com doFastWrites(true), 7211197Sandreas.hansson@arm.com prefetchOnAccess(p->prefetch_on_access), 7311197Sandreas.hansson@arm.com clusivity(p->clusivity), 7411199Sandreas.hansson@arm.com writebackClean(p->writeback_clean), 7511197Sandreas.hansson@arm.com tempBlockWriteback(nullptr), 7611197Sandreas.hansson@arm.com writebackTempBlockAtomicEvent(this, false, 7711197Sandreas.hansson@arm.com EventBase::Delayed_Writeback_Pri) 7811051Sandreas.hansson@arm.com{ 7911051Sandreas.hansson@arm.com tempBlock = new CacheBlk(); 8011051Sandreas.hansson@arm.com tempBlock->data = new uint8_t[blkSize]; 8111051Sandreas.hansson@arm.com 8211051Sandreas.hansson@arm.com cpuSidePort = new CpuSidePort(p->name + ".cpu_side", this, 8311051Sandreas.hansson@arm.com "CpuSidePort"); 8411051Sandreas.hansson@arm.com memSidePort = new MemSidePort(p->name + ".mem_side", this, 8511051Sandreas.hansson@arm.com "MemSidePort"); 8611051Sandreas.hansson@arm.com 8711051Sandreas.hansson@arm.com tags->setCache(this); 8811051Sandreas.hansson@arm.com if (prefetcher) 8911051Sandreas.hansson@arm.com prefetcher->setCache(this); 9011051Sandreas.hansson@arm.com} 9111051Sandreas.hansson@arm.com 9211051Sandreas.hansson@arm.comCache::~Cache() 9311051Sandreas.hansson@arm.com{ 9411051Sandreas.hansson@arm.com delete [] tempBlock->data; 9511051Sandreas.hansson@arm.com delete tempBlock; 9611051Sandreas.hansson@arm.com 9711051Sandreas.hansson@arm.com delete cpuSidePort; 9811051Sandreas.hansson@arm.com delete memSidePort; 9911051Sandreas.hansson@arm.com} 10011051Sandreas.hansson@arm.com 10111051Sandreas.hansson@arm.comvoid 10211051Sandreas.hansson@arm.comCache::regStats() 10311051Sandreas.hansson@arm.com{ 10411051Sandreas.hansson@arm.com BaseCache::regStats(); 10511051Sandreas.hansson@arm.com} 10611051Sandreas.hansson@arm.com 10711051Sandreas.hansson@arm.comvoid 10811051Sandreas.hansson@arm.comCache::cmpAndSwap(CacheBlk *blk, PacketPtr pkt) 10911051Sandreas.hansson@arm.com{ 11011051Sandreas.hansson@arm.com assert(pkt->isRequest()); 11111051Sandreas.hansson@arm.com 11211051Sandreas.hansson@arm.com uint64_t overwrite_val; 11311051Sandreas.hansson@arm.com bool overwrite_mem; 11411051Sandreas.hansson@arm.com uint64_t condition_val64; 11511051Sandreas.hansson@arm.com uint32_t condition_val32; 11611051Sandreas.hansson@arm.com 11711051Sandreas.hansson@arm.com int offset = tags->extractBlkOffset(pkt->getAddr()); 11811051Sandreas.hansson@arm.com uint8_t *blk_data = blk->data + offset; 11911051Sandreas.hansson@arm.com 12011051Sandreas.hansson@arm.com assert(sizeof(uint64_t) >= pkt->getSize()); 12111051Sandreas.hansson@arm.com 12211051Sandreas.hansson@arm.com overwrite_mem = true; 12311051Sandreas.hansson@arm.com // keep a copy of our possible write value, and copy what is at the 12411051Sandreas.hansson@arm.com // memory address into the packet 12511051Sandreas.hansson@arm.com pkt->writeData((uint8_t *)&overwrite_val); 12611051Sandreas.hansson@arm.com pkt->setData(blk_data); 12711051Sandreas.hansson@arm.com 12811051Sandreas.hansson@arm.com if (pkt->req->isCondSwap()) { 12911051Sandreas.hansson@arm.com if (pkt->getSize() == sizeof(uint64_t)) { 13011051Sandreas.hansson@arm.com condition_val64 = pkt->req->getExtraData(); 13111051Sandreas.hansson@arm.com overwrite_mem = !std::memcmp(&condition_val64, blk_data, 13211051Sandreas.hansson@arm.com sizeof(uint64_t)); 13311051Sandreas.hansson@arm.com } else if (pkt->getSize() == sizeof(uint32_t)) { 13411051Sandreas.hansson@arm.com condition_val32 = (uint32_t)pkt->req->getExtraData(); 13511051Sandreas.hansson@arm.com overwrite_mem = !std::memcmp(&condition_val32, blk_data, 13611051Sandreas.hansson@arm.com sizeof(uint32_t)); 13711051Sandreas.hansson@arm.com } else 13811051Sandreas.hansson@arm.com panic("Invalid size for conditional read/write\n"); 13911051Sandreas.hansson@arm.com } 14011051Sandreas.hansson@arm.com 14111051Sandreas.hansson@arm.com if (overwrite_mem) { 14211051Sandreas.hansson@arm.com std::memcpy(blk_data, &overwrite_val, pkt->getSize()); 14311051Sandreas.hansson@arm.com blk->status |= BlkDirty; 14411051Sandreas.hansson@arm.com } 14511051Sandreas.hansson@arm.com} 14611051Sandreas.hansson@arm.com 14711051Sandreas.hansson@arm.com 14811051Sandreas.hansson@arm.comvoid 14911051Sandreas.hansson@arm.comCache::satisfyCpuSideRequest(PacketPtr pkt, CacheBlk *blk, 15011051Sandreas.hansson@arm.com bool deferred_response, bool pending_downgrade) 15111051Sandreas.hansson@arm.com{ 15211051Sandreas.hansson@arm.com assert(pkt->isRequest()); 15311051Sandreas.hansson@arm.com 15411051Sandreas.hansson@arm.com assert(blk && blk->isValid()); 15511051Sandreas.hansson@arm.com // Occasionally this is not true... if we are a lower-level cache 15611051Sandreas.hansson@arm.com // satisfying a string of Read and ReadEx requests from 15711051Sandreas.hansson@arm.com // upper-level caches, a Read will mark the block as shared but we 15811051Sandreas.hansson@arm.com // can satisfy a following ReadEx anyway since we can rely on the 15911051Sandreas.hansson@arm.com // Read requester(s) to have buffered the ReadEx snoop and to 16011051Sandreas.hansson@arm.com // invalidate their blocks after receiving them. 16111284Sandreas.hansson@arm.com // assert(!pkt->needsWritable() || blk->isWritable()); 16211051Sandreas.hansson@arm.com assert(pkt->getOffset(blkSize) + pkt->getSize() <= blkSize); 16311051Sandreas.hansson@arm.com 16411051Sandreas.hansson@arm.com // Check RMW operations first since both isRead() and 16511051Sandreas.hansson@arm.com // isWrite() will be true for them 16611051Sandreas.hansson@arm.com if (pkt->cmd == MemCmd::SwapReq) { 16711051Sandreas.hansson@arm.com cmpAndSwap(blk, pkt); 16811051Sandreas.hansson@arm.com } else if (pkt->isWrite()) { 16911284Sandreas.hansson@arm.com // we have the block in a writable state and can go ahead, 17011284Sandreas.hansson@arm.com // note that the line may be also be considered writable in 17111284Sandreas.hansson@arm.com // downstream caches along the path to memory, but always 17211284Sandreas.hansson@arm.com // Exclusive, and never Modified 17311051Sandreas.hansson@arm.com assert(blk->isWritable()); 17411284Sandreas.hansson@arm.com // Write or WriteLine at the first cache with block in writable state 17511051Sandreas.hansson@arm.com if (blk->checkWrite(pkt)) { 17611051Sandreas.hansson@arm.com pkt->writeDataToBlock(blk->data, blkSize); 17711051Sandreas.hansson@arm.com } 17811284Sandreas.hansson@arm.com // Always mark the line as dirty (and thus transition to the 17911284Sandreas.hansson@arm.com // Modified state) even if we are a failed StoreCond so we 18011284Sandreas.hansson@arm.com // supply data to any snoops that have appended themselves to 18111284Sandreas.hansson@arm.com // this cache before knowing the store will fail. 18211051Sandreas.hansson@arm.com blk->status |= BlkDirty; 18311288Ssteve.reinhardt@amd.com DPRINTF(CacheVerbose, "%s for %s addr %#llx size %d (write)\n", 18411288Ssteve.reinhardt@amd.com __func__, pkt->cmdString(), pkt->getAddr(), pkt->getSize()); 18511051Sandreas.hansson@arm.com } else if (pkt->isRead()) { 18611051Sandreas.hansson@arm.com if (pkt->isLLSC()) { 18711051Sandreas.hansson@arm.com blk->trackLoadLocked(pkt); 18811051Sandreas.hansson@arm.com } 18911286Sandreas.hansson@arm.com 19011286Sandreas.hansson@arm.com // all read responses have a data payload 19111286Sandreas.hansson@arm.com assert(pkt->hasRespData()); 19211051Sandreas.hansson@arm.com pkt->setDataFromBlock(blk->data, blkSize); 19311286Sandreas.hansson@arm.com 19411051Sandreas.hansson@arm.com // determine if this read is from a (coherent) cache, or not 19511051Sandreas.hansson@arm.com // by looking at the command type; we could potentially add a 19611051Sandreas.hansson@arm.com // packet attribute such as 'FromCache' to make this check a 19711051Sandreas.hansson@arm.com // bit cleaner 19811051Sandreas.hansson@arm.com if (pkt->cmd == MemCmd::ReadExReq || 19911051Sandreas.hansson@arm.com pkt->cmd == MemCmd::ReadSharedReq || 20011051Sandreas.hansson@arm.com pkt->cmd == MemCmd::ReadCleanReq || 20111051Sandreas.hansson@arm.com pkt->cmd == MemCmd::SCUpgradeFailReq) { 20211051Sandreas.hansson@arm.com assert(pkt->getSize() == blkSize); 20311051Sandreas.hansson@arm.com // special handling for coherent block requests from 20411051Sandreas.hansson@arm.com // upper-level caches 20511284Sandreas.hansson@arm.com if (pkt->needsWritable()) { 20611051Sandreas.hansson@arm.com // sanity check 20711051Sandreas.hansson@arm.com assert(pkt->cmd == MemCmd::ReadExReq || 20811051Sandreas.hansson@arm.com pkt->cmd == MemCmd::SCUpgradeFailReq); 20911051Sandreas.hansson@arm.com 21011051Sandreas.hansson@arm.com // if we have a dirty copy, make sure the recipient 21111284Sandreas.hansson@arm.com // keeps it marked dirty (in the modified state) 21211051Sandreas.hansson@arm.com if (blk->isDirty()) { 21311284Sandreas.hansson@arm.com pkt->setCacheResponding(); 21411051Sandreas.hansson@arm.com } 21511197Sandreas.hansson@arm.com // on ReadExReq we give up our copy unconditionally, 21611197Sandreas.hansson@arm.com // even if this cache is mostly inclusive, we may want 21711197Sandreas.hansson@arm.com // to revisit this 21811197Sandreas.hansson@arm.com invalidateBlock(blk); 21911051Sandreas.hansson@arm.com } else if (blk->isWritable() && !pending_downgrade && 22011284Sandreas.hansson@arm.com !pkt->hasSharers() && 22111051Sandreas.hansson@arm.com pkt->cmd != MemCmd::ReadCleanReq) { 22211284Sandreas.hansson@arm.com // we can give the requester a writable copy on a read 22311284Sandreas.hansson@arm.com // request if: 22411284Sandreas.hansson@arm.com // - we have a writable copy at this level (& below) 22511051Sandreas.hansson@arm.com // - we don't have a pending snoop from below 22611051Sandreas.hansson@arm.com // signaling another read request 22711051Sandreas.hansson@arm.com // - no other cache above has a copy (otherwise it 22811284Sandreas.hansson@arm.com // would have set hasSharers flag when 22911284Sandreas.hansson@arm.com // snooping the packet) 23011284Sandreas.hansson@arm.com // - the read has explicitly asked for a clean 23111284Sandreas.hansson@arm.com // copy of the line 23211051Sandreas.hansson@arm.com if (blk->isDirty()) { 23311051Sandreas.hansson@arm.com // special considerations if we're owner: 23411051Sandreas.hansson@arm.com if (!deferred_response) { 23511284Sandreas.hansson@arm.com // respond with the line in Modified state 23611284Sandreas.hansson@arm.com // (cacheResponding set, hasSharers not set) 23711284Sandreas.hansson@arm.com pkt->setCacheResponding(); 23811197Sandreas.hansson@arm.com 23911284Sandreas.hansson@arm.com if (clusivity == Enums::mostly_excl) { 24011284Sandreas.hansson@arm.com // if this cache is mostly exclusive with 24111284Sandreas.hansson@arm.com // respect to the cache above, drop the 24211284Sandreas.hansson@arm.com // block, no need to first unset the dirty 24311284Sandreas.hansson@arm.com // bit 24411284Sandreas.hansson@arm.com invalidateBlock(blk); 24511284Sandreas.hansson@arm.com } else { 24611284Sandreas.hansson@arm.com // if this cache is mostly inclusive, we 24711284Sandreas.hansson@arm.com // keep the block in the Exclusive state, 24811284Sandreas.hansson@arm.com // and pass it upwards as Modified 24911284Sandreas.hansson@arm.com // (writable and dirty), hence we have 25011284Sandreas.hansson@arm.com // multiple caches, all on the same path 25111284Sandreas.hansson@arm.com // towards memory, all considering the 25211284Sandreas.hansson@arm.com // same block writable, but only one 25311284Sandreas.hansson@arm.com // considering it Modified 25411197Sandreas.hansson@arm.com 25511284Sandreas.hansson@arm.com // we get away with multiple caches (on 25611284Sandreas.hansson@arm.com // the same path to memory) considering 25711284Sandreas.hansson@arm.com // the block writeable as we always enter 25811284Sandreas.hansson@arm.com // the cache hierarchy through a cache, 25911284Sandreas.hansson@arm.com // and first snoop upwards in all other 26011284Sandreas.hansson@arm.com // branches 26111284Sandreas.hansson@arm.com blk->status &= ~BlkDirty; 26211197Sandreas.hansson@arm.com } 26311051Sandreas.hansson@arm.com } else { 26411051Sandreas.hansson@arm.com // if we're responding after our own miss, 26511051Sandreas.hansson@arm.com // there's a window where the recipient didn't 26611051Sandreas.hansson@arm.com // know it was getting ownership and may not 26711051Sandreas.hansson@arm.com // have responded to snoops correctly, so we 26811284Sandreas.hansson@arm.com // have to respond with a shared line 26911284Sandreas.hansson@arm.com pkt->setHasSharers(); 27011051Sandreas.hansson@arm.com } 27111051Sandreas.hansson@arm.com } 27211051Sandreas.hansson@arm.com } else { 27311051Sandreas.hansson@arm.com // otherwise only respond with a shared copy 27411284Sandreas.hansson@arm.com pkt->setHasSharers(); 27511051Sandreas.hansson@arm.com } 27611051Sandreas.hansson@arm.com } 27711051Sandreas.hansson@arm.com } else { 27811284Sandreas.hansson@arm.com // Upgrade or Invalidate 27911051Sandreas.hansson@arm.com assert(pkt->isUpgrade() || pkt->isInvalidate()); 28011197Sandreas.hansson@arm.com 28111197Sandreas.hansson@arm.com // for invalidations we could be looking at the temp block 28211197Sandreas.hansson@arm.com // (for upgrades we always allocate) 28311197Sandreas.hansson@arm.com invalidateBlock(blk); 28411288Ssteve.reinhardt@amd.com DPRINTF(CacheVerbose, "%s for %s addr %#llx size %d (invalidation)\n", 28511051Sandreas.hansson@arm.com __func__, pkt->cmdString(), pkt->getAddr(), pkt->getSize()); 28611051Sandreas.hansson@arm.com } 28711051Sandreas.hansson@arm.com} 28811051Sandreas.hansson@arm.com 28911051Sandreas.hansson@arm.com///////////////////////////////////////////////////// 29011051Sandreas.hansson@arm.com// 29111051Sandreas.hansson@arm.com// Access path: requests coming in from the CPU side 29211051Sandreas.hansson@arm.com// 29311051Sandreas.hansson@arm.com///////////////////////////////////////////////////// 29411051Sandreas.hansson@arm.com 29511051Sandreas.hansson@arm.combool 29611051Sandreas.hansson@arm.comCache::access(PacketPtr pkt, CacheBlk *&blk, Cycles &lat, 29711051Sandreas.hansson@arm.com PacketList &writebacks) 29811051Sandreas.hansson@arm.com{ 29911051Sandreas.hansson@arm.com // sanity check 30011051Sandreas.hansson@arm.com assert(pkt->isRequest()); 30111051Sandreas.hansson@arm.com 30211051Sandreas.hansson@arm.com chatty_assert(!(isReadOnly && pkt->isWrite()), 30311051Sandreas.hansson@arm.com "Should never see a write in a read-only cache %s\n", 30411051Sandreas.hansson@arm.com name()); 30511051Sandreas.hansson@arm.com 30611288Ssteve.reinhardt@amd.com DPRINTF(CacheVerbose, "%s for %s addr %#llx size %d\n", __func__, 30711051Sandreas.hansson@arm.com pkt->cmdString(), pkt->getAddr(), pkt->getSize()); 30811051Sandreas.hansson@arm.com 30911051Sandreas.hansson@arm.com if (pkt->req->isUncacheable()) { 31011051Sandreas.hansson@arm.com DPRINTF(Cache, "%s%s addr %#llx uncacheable\n", pkt->cmdString(), 31111051Sandreas.hansson@arm.com pkt->req->isInstFetch() ? " (ifetch)" : "", 31211051Sandreas.hansson@arm.com pkt->getAddr()); 31311051Sandreas.hansson@arm.com 31411051Sandreas.hansson@arm.com // flush and invalidate any existing block 31511051Sandreas.hansson@arm.com CacheBlk *old_blk(tags->findBlock(pkt->getAddr(), pkt->isSecure())); 31611051Sandreas.hansson@arm.com if (old_blk && old_blk->isValid()) { 31711199Sandreas.hansson@arm.com if (old_blk->isDirty() || writebackClean) 31811051Sandreas.hansson@arm.com writebacks.push_back(writebackBlk(old_blk)); 31911051Sandreas.hansson@arm.com else 32011051Sandreas.hansson@arm.com writebacks.push_back(cleanEvictBlk(old_blk)); 32111051Sandreas.hansson@arm.com tags->invalidate(old_blk); 32211051Sandreas.hansson@arm.com old_blk->invalidate(); 32311051Sandreas.hansson@arm.com } 32411051Sandreas.hansson@arm.com 32511484Snikos.nikoleris@arm.com blk = nullptr; 32611051Sandreas.hansson@arm.com // lookupLatency is the latency in case the request is uncacheable. 32711051Sandreas.hansson@arm.com lat = lookupLatency; 32811051Sandreas.hansson@arm.com return false; 32911051Sandreas.hansson@arm.com } 33011051Sandreas.hansson@arm.com 33111051Sandreas.hansson@arm.com ContextID id = pkt->req->hasContextId() ? 33211051Sandreas.hansson@arm.com pkt->req->contextId() : InvalidContextID; 33311051Sandreas.hansson@arm.com // Here lat is the value passed as parameter to accessBlock() function 33411051Sandreas.hansson@arm.com // that can modify its value. 33511051Sandreas.hansson@arm.com blk = tags->accessBlock(pkt->getAddr(), pkt->isSecure(), lat, id); 33611051Sandreas.hansson@arm.com 33711051Sandreas.hansson@arm.com DPRINTF(Cache, "%s%s addr %#llx size %d (%s) %s\n", pkt->cmdString(), 33811051Sandreas.hansson@arm.com pkt->req->isInstFetch() ? " (ifetch)" : "", 33911051Sandreas.hansson@arm.com pkt->getAddr(), pkt->getSize(), pkt->isSecure() ? "s" : "ns", 34011051Sandreas.hansson@arm.com blk ? "hit " + blk->print() : "miss"); 34111051Sandreas.hansson@arm.com 34211051Sandreas.hansson@arm.com 34311199Sandreas.hansson@arm.com if (pkt->isEviction()) { 34411051Sandreas.hansson@arm.com // We check for presence of block in above caches before issuing 34511051Sandreas.hansson@arm.com // Writeback or CleanEvict to write buffer. Therefore the only 34611051Sandreas.hansson@arm.com // possible cases can be of a CleanEvict packet coming from above 34711051Sandreas.hansson@arm.com // encountering a Writeback generated in this cache peer cache and 34811051Sandreas.hansson@arm.com // waiting in the write buffer. Cases of upper level peer caches 34911051Sandreas.hansson@arm.com // generating CleanEvict and Writeback or simply CleanEvict and 35011051Sandreas.hansson@arm.com // CleanEvict almost simultaneously will be caught by snoops sent out 35111051Sandreas.hansson@arm.com // by crossbar. 35211375Sandreas.hansson@arm.com WriteQueueEntry *wb_entry = writeBuffer.findMatch(pkt->getAddr(), 35311375Sandreas.hansson@arm.com pkt->isSecure()); 35411375Sandreas.hansson@arm.com if (wb_entry) { 35511199Sandreas.hansson@arm.com assert(wb_entry->getNumTargets() == 1); 35611199Sandreas.hansson@arm.com PacketPtr wbPkt = wb_entry->getTarget()->pkt; 35711199Sandreas.hansson@arm.com assert(wbPkt->isWriteback()); 35811199Sandreas.hansson@arm.com 35911199Sandreas.hansson@arm.com if (pkt->isCleanEviction()) { 36011199Sandreas.hansson@arm.com // The CleanEvict and WritebackClean snoops into other 36111199Sandreas.hansson@arm.com // peer caches of the same level while traversing the 36211199Sandreas.hansson@arm.com // crossbar. If a copy of the block is found, the 36311199Sandreas.hansson@arm.com // packet is deleted in the crossbar. Hence, none of 36411199Sandreas.hansson@arm.com // the other upper level caches connected to this 36511199Sandreas.hansson@arm.com // cache have the block, so we can clear the 36611199Sandreas.hansson@arm.com // BLOCK_CACHED flag in the Writeback if set and 36711199Sandreas.hansson@arm.com // discard the CleanEvict by returning true. 36811199Sandreas.hansson@arm.com wbPkt->clearBlockCached(); 36911199Sandreas.hansson@arm.com return true; 37011199Sandreas.hansson@arm.com } else { 37111199Sandreas.hansson@arm.com assert(pkt->cmd == MemCmd::WritebackDirty); 37211199Sandreas.hansson@arm.com // Dirty writeback from above trumps our clean 37311199Sandreas.hansson@arm.com // writeback... discard here 37411199Sandreas.hansson@arm.com // Note: markInService will remove entry from writeback buffer. 37511375Sandreas.hansson@arm.com markInService(wb_entry); 37611199Sandreas.hansson@arm.com delete wbPkt; 37711199Sandreas.hansson@arm.com } 37811051Sandreas.hansson@arm.com } 37911051Sandreas.hansson@arm.com } 38011051Sandreas.hansson@arm.com 38111051Sandreas.hansson@arm.com // Writeback handling is special case. We can write the block into 38211051Sandreas.hansson@arm.com // the cache without having a writeable copy (or any copy at all). 38311199Sandreas.hansson@arm.com if (pkt->isWriteback()) { 38411051Sandreas.hansson@arm.com assert(blkSize == pkt->getSize()); 38511199Sandreas.hansson@arm.com 38611199Sandreas.hansson@arm.com // we could get a clean writeback while we are having 38711199Sandreas.hansson@arm.com // outstanding accesses to a block, do the simple thing for 38811199Sandreas.hansson@arm.com // now and drop the clean writeback so that we do not upset 38911199Sandreas.hansson@arm.com // any ordering/decisions about ownership already taken 39011199Sandreas.hansson@arm.com if (pkt->cmd == MemCmd::WritebackClean && 39111199Sandreas.hansson@arm.com mshrQueue.findMatch(pkt->getAddr(), pkt->isSecure())) { 39211199Sandreas.hansson@arm.com DPRINTF(Cache, "Clean writeback %#llx to block with MSHR, " 39311199Sandreas.hansson@arm.com "dropping\n", pkt->getAddr()); 39411199Sandreas.hansson@arm.com return true; 39511199Sandreas.hansson@arm.com } 39611199Sandreas.hansson@arm.com 39711484Snikos.nikoleris@arm.com if (blk == nullptr) { 39811051Sandreas.hansson@arm.com // need to do a replacement 39911051Sandreas.hansson@arm.com blk = allocateBlock(pkt->getAddr(), pkt->isSecure(), writebacks); 40011484Snikos.nikoleris@arm.com if (blk == nullptr) { 40111051Sandreas.hansson@arm.com // no replaceable block available: give up, fwd to next level. 40211051Sandreas.hansson@arm.com incMissCount(pkt); 40311051Sandreas.hansson@arm.com return false; 40411051Sandreas.hansson@arm.com } 40511051Sandreas.hansson@arm.com tags->insertBlock(pkt, blk); 40611051Sandreas.hansson@arm.com 40711051Sandreas.hansson@arm.com blk->status = (BlkValid | BlkReadable); 40811051Sandreas.hansson@arm.com if (pkt->isSecure()) { 40911051Sandreas.hansson@arm.com blk->status |= BlkSecure; 41011051Sandreas.hansson@arm.com } 41111051Sandreas.hansson@arm.com } 41211199Sandreas.hansson@arm.com // only mark the block dirty if we got a writeback command, 41311199Sandreas.hansson@arm.com // and leave it as is for a clean writeback 41411199Sandreas.hansson@arm.com if (pkt->cmd == MemCmd::WritebackDirty) { 41511199Sandreas.hansson@arm.com blk->status |= BlkDirty; 41611199Sandreas.hansson@arm.com } 41711284Sandreas.hansson@arm.com // if the packet does not have sharers, it is passing 41811284Sandreas.hansson@arm.com // writable, and we got the writeback in Modified or Exclusive 41911284Sandreas.hansson@arm.com // state, if not we are in the Owned or Shared state 42011284Sandreas.hansson@arm.com if (!pkt->hasSharers()) { 42111051Sandreas.hansson@arm.com blk->status |= BlkWritable; 42211051Sandreas.hansson@arm.com } 42311051Sandreas.hansson@arm.com // nothing else to do; writeback doesn't expect response 42411051Sandreas.hansson@arm.com assert(!pkt->needsResponse()); 42511051Sandreas.hansson@arm.com std::memcpy(blk->data, pkt->getConstPtr<uint8_t>(), blkSize); 42611051Sandreas.hansson@arm.com DPRINTF(Cache, "%s new state is %s\n", __func__, blk->print()); 42711051Sandreas.hansson@arm.com incHitCount(pkt); 42811051Sandreas.hansson@arm.com return true; 42911051Sandreas.hansson@arm.com } else if (pkt->cmd == MemCmd::CleanEvict) { 43011484Snikos.nikoleris@arm.com if (blk != nullptr) { 43111051Sandreas.hansson@arm.com // Found the block in the tags, need to stop CleanEvict from 43211051Sandreas.hansson@arm.com // propagating further down the hierarchy. Returning true will 43311051Sandreas.hansson@arm.com // treat the CleanEvict like a satisfied write request and delete 43411051Sandreas.hansson@arm.com // it. 43511051Sandreas.hansson@arm.com return true; 43611051Sandreas.hansson@arm.com } 43711051Sandreas.hansson@arm.com // We didn't find the block here, propagate the CleanEvict further 43811051Sandreas.hansson@arm.com // down the memory hierarchy. Returning false will treat the CleanEvict 43911051Sandreas.hansson@arm.com // like a Writeback which could not find a replaceable block so has to 44011051Sandreas.hansson@arm.com // go to next level. 44111051Sandreas.hansson@arm.com return false; 44211484Snikos.nikoleris@arm.com } else if ((blk != nullptr) && 44311483Snikos.nikoleris@arm.com (pkt->needsWritable() ? blk->isWritable() : 44411483Snikos.nikoleris@arm.com blk->isReadable())) { 44511051Sandreas.hansson@arm.com // OK to satisfy access 44611051Sandreas.hansson@arm.com incHitCount(pkt); 44711051Sandreas.hansson@arm.com satisfyCpuSideRequest(pkt, blk); 44811051Sandreas.hansson@arm.com return true; 44911051Sandreas.hansson@arm.com } 45011051Sandreas.hansson@arm.com 45111484Snikos.nikoleris@arm.com // Can't satisfy access normally... either no block (blk == nullptr) 45211284Sandreas.hansson@arm.com // or have block but need writable 45311051Sandreas.hansson@arm.com 45411051Sandreas.hansson@arm.com incMissCount(pkt); 45511051Sandreas.hansson@arm.com 45611484Snikos.nikoleris@arm.com if (blk == nullptr && pkt->isLLSC() && pkt->isWrite()) { 45711051Sandreas.hansson@arm.com // complete miss on store conditional... just give up now 45811051Sandreas.hansson@arm.com pkt->req->setExtraData(0); 45911051Sandreas.hansson@arm.com return true; 46011051Sandreas.hansson@arm.com } 46111051Sandreas.hansson@arm.com 46211051Sandreas.hansson@arm.com return false; 46311051Sandreas.hansson@arm.com} 46411051Sandreas.hansson@arm.com 46511051Sandreas.hansson@arm.comvoid 46611051Sandreas.hansson@arm.comCache::doWritebacks(PacketList& writebacks, Tick forward_time) 46711051Sandreas.hansson@arm.com{ 46811051Sandreas.hansson@arm.com while (!writebacks.empty()) { 46911051Sandreas.hansson@arm.com PacketPtr wbPkt = writebacks.front(); 47011051Sandreas.hansson@arm.com // We use forwardLatency here because we are copying writebacks to 47111051Sandreas.hansson@arm.com // write buffer. Call isCachedAbove for both Writebacks and 47211051Sandreas.hansson@arm.com // CleanEvicts. If isCachedAbove returns true we set BLOCK_CACHED flag 47311051Sandreas.hansson@arm.com // in Writebacks and discard CleanEvicts. 47411051Sandreas.hansson@arm.com if (isCachedAbove(wbPkt)) { 47511051Sandreas.hansson@arm.com if (wbPkt->cmd == MemCmd::CleanEvict) { 47611051Sandreas.hansson@arm.com // Delete CleanEvict because cached copies exist above. The 47711051Sandreas.hansson@arm.com // packet destructor will delete the request object because 47811051Sandreas.hansson@arm.com // this is a non-snoop request packet which does not require a 47911051Sandreas.hansson@arm.com // response. 48011051Sandreas.hansson@arm.com delete wbPkt; 48111199Sandreas.hansson@arm.com } else if (wbPkt->cmd == MemCmd::WritebackClean) { 48211199Sandreas.hansson@arm.com // clean writeback, do not send since the block is 48311199Sandreas.hansson@arm.com // still cached above 48411199Sandreas.hansson@arm.com assert(writebackClean); 48511199Sandreas.hansson@arm.com delete wbPkt; 48611051Sandreas.hansson@arm.com } else { 48711199Sandreas.hansson@arm.com assert(wbPkt->cmd == MemCmd::WritebackDirty); 48811051Sandreas.hansson@arm.com // Set BLOCK_CACHED flag in Writeback and send below, so that 48911051Sandreas.hansson@arm.com // the Writeback does not reset the bit corresponding to this 49011051Sandreas.hansson@arm.com // address in the snoop filter below. 49111051Sandreas.hansson@arm.com wbPkt->setBlockCached(); 49211051Sandreas.hansson@arm.com allocateWriteBuffer(wbPkt, forward_time); 49311051Sandreas.hansson@arm.com } 49411051Sandreas.hansson@arm.com } else { 49511051Sandreas.hansson@arm.com // If the block is not cached above, send packet below. Both 49611051Sandreas.hansson@arm.com // CleanEvict and Writeback with BLOCK_CACHED flag cleared will 49711051Sandreas.hansson@arm.com // reset the bit corresponding to this address in the snoop filter 49811051Sandreas.hansson@arm.com // below. 49911051Sandreas.hansson@arm.com allocateWriteBuffer(wbPkt, forward_time); 50011051Sandreas.hansson@arm.com } 50111051Sandreas.hansson@arm.com writebacks.pop_front(); 50211051Sandreas.hansson@arm.com } 50311051Sandreas.hansson@arm.com} 50411051Sandreas.hansson@arm.com 50511130Sali.jafri@arm.comvoid 50611130Sali.jafri@arm.comCache::doWritebacksAtomic(PacketList& writebacks) 50711130Sali.jafri@arm.com{ 50811130Sali.jafri@arm.com while (!writebacks.empty()) { 50911130Sali.jafri@arm.com PacketPtr wbPkt = writebacks.front(); 51011130Sali.jafri@arm.com // Call isCachedAbove for both Writebacks and CleanEvicts. If 51111130Sali.jafri@arm.com // isCachedAbove returns true we set BLOCK_CACHED flag in Writebacks 51211130Sali.jafri@arm.com // and discard CleanEvicts. 51311130Sali.jafri@arm.com if (isCachedAbove(wbPkt, false)) { 51411199Sandreas.hansson@arm.com if (wbPkt->cmd == MemCmd::WritebackDirty) { 51511130Sali.jafri@arm.com // Set BLOCK_CACHED flag in Writeback and send below, 51611130Sali.jafri@arm.com // so that the Writeback does not reset the bit 51711130Sali.jafri@arm.com // corresponding to this address in the snoop filter 51811130Sali.jafri@arm.com // below. We can discard CleanEvicts because cached 51911130Sali.jafri@arm.com // copies exist above. Atomic mode isCachedAbove 52011130Sali.jafri@arm.com // modifies packet to set BLOCK_CACHED flag 52111130Sali.jafri@arm.com memSidePort->sendAtomic(wbPkt); 52211130Sali.jafri@arm.com } 52311130Sali.jafri@arm.com } else { 52411130Sali.jafri@arm.com // If the block is not cached above, send packet below. Both 52511130Sali.jafri@arm.com // CleanEvict and Writeback with BLOCK_CACHED flag cleared will 52611130Sali.jafri@arm.com // reset the bit corresponding to this address in the snoop filter 52711130Sali.jafri@arm.com // below. 52811130Sali.jafri@arm.com memSidePort->sendAtomic(wbPkt); 52911130Sali.jafri@arm.com } 53011130Sali.jafri@arm.com writebacks.pop_front(); 53111130Sali.jafri@arm.com // In case of CleanEvicts, the packet destructor will delete the 53211130Sali.jafri@arm.com // request object because this is a non-snoop request packet which 53311130Sali.jafri@arm.com // does not require a response. 53411130Sali.jafri@arm.com delete wbPkt; 53511130Sali.jafri@arm.com } 53611130Sali.jafri@arm.com} 53711130Sali.jafri@arm.com 53811051Sandreas.hansson@arm.com 53911051Sandreas.hansson@arm.comvoid 54011051Sandreas.hansson@arm.comCache::recvTimingSnoopResp(PacketPtr pkt) 54111051Sandreas.hansson@arm.com{ 54211051Sandreas.hansson@arm.com DPRINTF(Cache, "%s for %s addr %#llx size %d\n", __func__, 54311051Sandreas.hansson@arm.com pkt->cmdString(), pkt->getAddr(), pkt->getSize()); 54411051Sandreas.hansson@arm.com 54511051Sandreas.hansson@arm.com assert(pkt->isResponse()); 54611051Sandreas.hansson@arm.com assert(!system->bypassCaches()); 54711051Sandreas.hansson@arm.com 54811276Sandreas.hansson@arm.com // determine if the response is from a snoop request we created 54911276Sandreas.hansson@arm.com // (in which case it should be in the outstandingSnoop), or if we 55011276Sandreas.hansson@arm.com // merely forwarded someone else's snoop request 55111276Sandreas.hansson@arm.com const bool forwardAsSnoop = outstandingSnoop.find(pkt->req) == 55211276Sandreas.hansson@arm.com outstandingSnoop.end(); 55311276Sandreas.hansson@arm.com 55411276Sandreas.hansson@arm.com if (!forwardAsSnoop) { 55511276Sandreas.hansson@arm.com // the packet came from this cache, so sink it here and do not 55611276Sandreas.hansson@arm.com // forward it 55711051Sandreas.hansson@arm.com assert(pkt->cmd == MemCmd::HardPFResp); 55811276Sandreas.hansson@arm.com 55911276Sandreas.hansson@arm.com outstandingSnoop.erase(pkt->req); 56011276Sandreas.hansson@arm.com 56111276Sandreas.hansson@arm.com DPRINTF(Cache, "Got prefetch response from above for addr " 56211276Sandreas.hansson@arm.com "%#llx (%s)\n", pkt->getAddr(), pkt->isSecure() ? "s" : "ns"); 56311051Sandreas.hansson@arm.com recvTimingResp(pkt); 56411051Sandreas.hansson@arm.com return; 56511051Sandreas.hansson@arm.com } 56611051Sandreas.hansson@arm.com 56711051Sandreas.hansson@arm.com // forwardLatency is set here because there is a response from an 56811051Sandreas.hansson@arm.com // upper level cache. 56911051Sandreas.hansson@arm.com // To pay the delay that occurs if the packet comes from the bus, 57011051Sandreas.hansson@arm.com // we charge also headerDelay. 57111051Sandreas.hansson@arm.com Tick snoop_resp_time = clockEdge(forwardLatency) + pkt->headerDelay; 57211051Sandreas.hansson@arm.com // Reset the timing of the packet. 57311051Sandreas.hansson@arm.com pkt->headerDelay = pkt->payloadDelay = 0; 57411051Sandreas.hansson@arm.com memSidePort->schedTimingSnoopResp(pkt, snoop_resp_time); 57511051Sandreas.hansson@arm.com} 57611051Sandreas.hansson@arm.com 57711051Sandreas.hansson@arm.comvoid 57811051Sandreas.hansson@arm.comCache::promoteWholeLineWrites(PacketPtr pkt) 57911051Sandreas.hansson@arm.com{ 58011051Sandreas.hansson@arm.com // Cache line clearing instructions 58111051Sandreas.hansson@arm.com if (doFastWrites && (pkt->cmd == MemCmd::WriteReq) && 58211051Sandreas.hansson@arm.com (pkt->getSize() == blkSize) && (pkt->getOffset(blkSize) == 0)) { 58311051Sandreas.hansson@arm.com pkt->cmd = MemCmd::WriteLineReq; 58411051Sandreas.hansson@arm.com DPRINTF(Cache, "packet promoted from Write to WriteLineReq\n"); 58511051Sandreas.hansson@arm.com } 58611051Sandreas.hansson@arm.com} 58711051Sandreas.hansson@arm.com 58811051Sandreas.hansson@arm.combool 58911051Sandreas.hansson@arm.comCache::recvTimingReq(PacketPtr pkt) 59011051Sandreas.hansson@arm.com{ 59111051Sandreas.hansson@arm.com DPRINTF(CacheTags, "%s tags: %s\n", __func__, tags->print()); 59211051Sandreas.hansson@arm.com 59311051Sandreas.hansson@arm.com assert(pkt->isRequest()); 59411051Sandreas.hansson@arm.com 59511051Sandreas.hansson@arm.com // Just forward the packet if caches are disabled. 59611051Sandreas.hansson@arm.com if (system->bypassCaches()) { 59711051Sandreas.hansson@arm.com // @todo This should really enqueue the packet rather 59811051Sandreas.hansson@arm.com bool M5_VAR_USED success = memSidePort->sendTimingReq(pkt); 59911051Sandreas.hansson@arm.com assert(success); 60011051Sandreas.hansson@arm.com return true; 60111051Sandreas.hansson@arm.com } 60211051Sandreas.hansson@arm.com 60311051Sandreas.hansson@arm.com promoteWholeLineWrites(pkt); 60411051Sandreas.hansson@arm.com 60511284Sandreas.hansson@arm.com if (pkt->cacheResponding()) { 60611051Sandreas.hansson@arm.com // a cache above us (but not where the packet came from) is 60711284Sandreas.hansson@arm.com // responding to the request, in other words it has the line 60811284Sandreas.hansson@arm.com // in Modified or Owned state 60911284Sandreas.hansson@arm.com DPRINTF(Cache, "Cache above responding to %#llx (%s): " 61011284Sandreas.hansson@arm.com "not responding\n", 61111051Sandreas.hansson@arm.com pkt->getAddr(), pkt->isSecure() ? "s" : "ns"); 61211051Sandreas.hansson@arm.com 61311284Sandreas.hansson@arm.com // if the packet needs the block to be writable, and the cache 61411284Sandreas.hansson@arm.com // that has promised to respond (setting the cache responding 61511284Sandreas.hansson@arm.com // flag) is not providing writable (it is in Owned rather than 61611284Sandreas.hansson@arm.com // the Modified state), we know that there may be other Shared 61711284Sandreas.hansson@arm.com // copies in the system; go out and invalidate them all 61811334Sandreas.hansson@arm.com assert(pkt->needsWritable() && !pkt->responderHadWritable()); 61911284Sandreas.hansson@arm.com 62011334Sandreas.hansson@arm.com // an upstream cache that had the line in Owned state 62111334Sandreas.hansson@arm.com // (dirty, but not writable), is responding and thus 62211334Sandreas.hansson@arm.com // transferring the dirty line from one branch of the 62311334Sandreas.hansson@arm.com // cache hierarchy to another 62411284Sandreas.hansson@arm.com 62511334Sandreas.hansson@arm.com // send out an express snoop and invalidate all other 62611334Sandreas.hansson@arm.com // copies (snooping a packet that needs writable is the 62711334Sandreas.hansson@arm.com // same as an invalidation), thus turning the Owned line 62811334Sandreas.hansson@arm.com // into a Modified line, note that we don't invalidate the 62911334Sandreas.hansson@arm.com // block in the current cache or any other cache on the 63011334Sandreas.hansson@arm.com // path to memory 63111051Sandreas.hansson@arm.com 63211334Sandreas.hansson@arm.com // create a downstream express snoop with cleared packet 63311334Sandreas.hansson@arm.com // flags, there is no need to allocate any data as the 63411334Sandreas.hansson@arm.com // packet is merely used to co-ordinate state transitions 63511334Sandreas.hansson@arm.com Packet *snoop_pkt = new Packet(pkt, true, false); 63611051Sandreas.hansson@arm.com 63711334Sandreas.hansson@arm.com // also reset the bus time that the original packet has 63811334Sandreas.hansson@arm.com // not yet paid for 63911334Sandreas.hansson@arm.com snoop_pkt->headerDelay = snoop_pkt->payloadDelay = 0; 64011051Sandreas.hansson@arm.com 64111334Sandreas.hansson@arm.com // make this an instantaneous express snoop, and let the 64211334Sandreas.hansson@arm.com // other caches in the system know that the another cache 64311334Sandreas.hansson@arm.com // is responding, because we have found the authorative 64411334Sandreas.hansson@arm.com // copy (Modified or Owned) that will supply the right 64511334Sandreas.hansson@arm.com // data 64611334Sandreas.hansson@arm.com snoop_pkt->setExpressSnoop(); 64711334Sandreas.hansson@arm.com snoop_pkt->setCacheResponding(); 64811051Sandreas.hansson@arm.com 64911334Sandreas.hansson@arm.com // this express snoop travels towards the memory, and at 65011334Sandreas.hansson@arm.com // every crossbar it is snooped upwards thus reaching 65111334Sandreas.hansson@arm.com // every cache in the system 65211334Sandreas.hansson@arm.com bool M5_VAR_USED success = memSidePort->sendTimingReq(snoop_pkt); 65311334Sandreas.hansson@arm.com // express snoops always succeed 65411334Sandreas.hansson@arm.com assert(success); 65511334Sandreas.hansson@arm.com 65611334Sandreas.hansson@arm.com // main memory will delete the snoop packet 65711051Sandreas.hansson@arm.com 65811284Sandreas.hansson@arm.com // queue for deletion, as opposed to immediate deletion, as 65911284Sandreas.hansson@arm.com // the sending cache is still relying on the packet 66011190Sandreas.hansson@arm.com pendingDelete.reset(pkt); 66111051Sandreas.hansson@arm.com 66211334Sandreas.hansson@arm.com // no need to take any further action in this particular cache 66311334Sandreas.hansson@arm.com // as an upstram cache has already committed to responding, 66411334Sandreas.hansson@arm.com // and we have already sent out any express snoops in the 66511334Sandreas.hansson@arm.com // section above to ensure all other copies in the system are 66611334Sandreas.hansson@arm.com // invalidated 66711051Sandreas.hansson@arm.com return true; 66811051Sandreas.hansson@arm.com } 66911051Sandreas.hansson@arm.com 67011051Sandreas.hansson@arm.com // anything that is merely forwarded pays for the forward latency and 67111051Sandreas.hansson@arm.com // the delay provided by the crossbar 67211051Sandreas.hansson@arm.com Tick forward_time = clockEdge(forwardLatency) + pkt->headerDelay; 67311051Sandreas.hansson@arm.com 67411051Sandreas.hansson@arm.com // We use lookupLatency here because it is used to specify the latency 67511051Sandreas.hansson@arm.com // to access. 67611051Sandreas.hansson@arm.com Cycles lat = lookupLatency; 67711484Snikos.nikoleris@arm.com CacheBlk *blk = nullptr; 67811051Sandreas.hansson@arm.com bool satisfied = false; 67911051Sandreas.hansson@arm.com { 68011051Sandreas.hansson@arm.com PacketList writebacks; 68111051Sandreas.hansson@arm.com // Note that lat is passed by reference here. The function 68211051Sandreas.hansson@arm.com // access() calls accessBlock() which can modify lat value. 68311051Sandreas.hansson@arm.com satisfied = access(pkt, blk, lat, writebacks); 68411051Sandreas.hansson@arm.com 68511051Sandreas.hansson@arm.com // copy writebacks to write buffer here to ensure they logically 68611051Sandreas.hansson@arm.com // proceed anything happening below 68711051Sandreas.hansson@arm.com doWritebacks(writebacks, forward_time); 68811051Sandreas.hansson@arm.com } 68911051Sandreas.hansson@arm.com 69011051Sandreas.hansson@arm.com // Here we charge the headerDelay that takes into account the latencies 69111051Sandreas.hansson@arm.com // of the bus, if the packet comes from it. 69211051Sandreas.hansson@arm.com // The latency charged it is just lat that is the value of lookupLatency 69311051Sandreas.hansson@arm.com // modified by access() function, or if not just lookupLatency. 69411051Sandreas.hansson@arm.com // In case of a hit we are neglecting response latency. 69511051Sandreas.hansson@arm.com // In case of a miss we are neglecting forward latency. 69611051Sandreas.hansson@arm.com Tick request_time = clockEdge(lat) + pkt->headerDelay; 69711051Sandreas.hansson@arm.com // Here we reset the timing of the packet. 69811051Sandreas.hansson@arm.com pkt->headerDelay = pkt->payloadDelay = 0; 69911051Sandreas.hansson@arm.com 70011051Sandreas.hansson@arm.com // track time of availability of next prefetch, if any 70111051Sandreas.hansson@arm.com Tick next_pf_time = MaxTick; 70211051Sandreas.hansson@arm.com 70311051Sandreas.hansson@arm.com bool needsResponse = pkt->needsResponse(); 70411051Sandreas.hansson@arm.com 70511051Sandreas.hansson@arm.com if (satisfied) { 70611051Sandreas.hansson@arm.com // should never be satisfying an uncacheable access as we 70711051Sandreas.hansson@arm.com // flush and invalidate any existing block as part of the 70811051Sandreas.hansson@arm.com // lookup 70911051Sandreas.hansson@arm.com assert(!pkt->req->isUncacheable()); 71011051Sandreas.hansson@arm.com 71111051Sandreas.hansson@arm.com // hit (for all other request types) 71211051Sandreas.hansson@arm.com 71311483Snikos.nikoleris@arm.com if (prefetcher && (prefetchOnAccess || 71411483Snikos.nikoleris@arm.com (blk && blk->wasPrefetched()))) { 71511051Sandreas.hansson@arm.com if (blk) 71611051Sandreas.hansson@arm.com blk->status &= ~BlkHWPrefetched; 71711051Sandreas.hansson@arm.com 71811051Sandreas.hansson@arm.com // Don't notify on SWPrefetch 71911051Sandreas.hansson@arm.com if (!pkt->cmd.isSWPrefetch()) 72011051Sandreas.hansson@arm.com next_pf_time = prefetcher->notify(pkt); 72111051Sandreas.hansson@arm.com } 72211051Sandreas.hansson@arm.com 72311051Sandreas.hansson@arm.com if (needsResponse) { 72411051Sandreas.hansson@arm.com pkt->makeTimingResponse(); 72511051Sandreas.hansson@arm.com // @todo: Make someone pay for this 72611051Sandreas.hansson@arm.com pkt->headerDelay = pkt->payloadDelay = 0; 72711051Sandreas.hansson@arm.com 72811051Sandreas.hansson@arm.com // In this case we are considering request_time that takes 72911051Sandreas.hansson@arm.com // into account the delay of the xbar, if any, and just 73011051Sandreas.hansson@arm.com // lat, neglecting responseLatency, modelling hit latency 73111051Sandreas.hansson@arm.com // just as lookupLatency or or the value of lat overriden 73211051Sandreas.hansson@arm.com // by access(), that calls accessBlock() function. 73311194Sali.jafri@arm.com cpuSidePort->schedTimingResp(pkt, request_time, true); 73411051Sandreas.hansson@arm.com } else { 73511199Sandreas.hansson@arm.com DPRINTF(Cache, "%s satisfied %s addr %#llx, no response needed\n", 73611558Snikos.nikoleris@arm.com __func__, pkt->cmdString(), pkt->getAddr()); 73711199Sandreas.hansson@arm.com 73811190Sandreas.hansson@arm.com // queue the packet for deletion, as the sending cache is 73911190Sandreas.hansson@arm.com // still relying on it; if the block is found in access(), 74011190Sandreas.hansson@arm.com // CleanEvict and Writeback messages will be deleted 74111190Sandreas.hansson@arm.com // here as well 74211190Sandreas.hansson@arm.com pendingDelete.reset(pkt); 74311051Sandreas.hansson@arm.com } 74411051Sandreas.hansson@arm.com } else { 74511051Sandreas.hansson@arm.com // miss 74611051Sandreas.hansson@arm.com 74711051Sandreas.hansson@arm.com Addr blk_addr = blockAlign(pkt->getAddr()); 74811051Sandreas.hansson@arm.com 74911051Sandreas.hansson@arm.com // ignore any existing MSHR if we are dealing with an 75011051Sandreas.hansson@arm.com // uncacheable request 75111051Sandreas.hansson@arm.com MSHR *mshr = pkt->req->isUncacheable() ? nullptr : 75211051Sandreas.hansson@arm.com mshrQueue.findMatch(blk_addr, pkt->isSecure()); 75311051Sandreas.hansson@arm.com 75411051Sandreas.hansson@arm.com // Software prefetch handling: 75511051Sandreas.hansson@arm.com // To keep the core from waiting on data it won't look at 75611051Sandreas.hansson@arm.com // anyway, send back a response with dummy data. Miss handling 75711051Sandreas.hansson@arm.com // will continue asynchronously. Unfortunately, the core will 75811051Sandreas.hansson@arm.com // insist upon freeing original Packet/Request, so we have to 75911051Sandreas.hansson@arm.com // create a new pair with a different lifecycle. Note that this 76011051Sandreas.hansson@arm.com // processing happens before any MSHR munging on the behalf of 76111051Sandreas.hansson@arm.com // this request because this new Request will be the one stored 76211051Sandreas.hansson@arm.com // into the MSHRs, not the original. 76311051Sandreas.hansson@arm.com if (pkt->cmd.isSWPrefetch()) { 76411051Sandreas.hansson@arm.com assert(needsResponse); 76511051Sandreas.hansson@arm.com assert(pkt->req->hasPaddr()); 76611051Sandreas.hansson@arm.com assert(!pkt->req->isUncacheable()); 76711051Sandreas.hansson@arm.com 76811051Sandreas.hansson@arm.com // There's no reason to add a prefetch as an additional target 76911051Sandreas.hansson@arm.com // to an existing MSHR. If an outstanding request is already 77011051Sandreas.hansson@arm.com // in progress, there is nothing for the prefetch to do. 77111051Sandreas.hansson@arm.com // If this is the case, we don't even create a request at all. 77211051Sandreas.hansson@arm.com PacketPtr pf = nullptr; 77311051Sandreas.hansson@arm.com 77411051Sandreas.hansson@arm.com if (!mshr) { 77511051Sandreas.hansson@arm.com // copy the request and create a new SoftPFReq packet 77611051Sandreas.hansson@arm.com RequestPtr req = new Request(pkt->req->getPaddr(), 77711051Sandreas.hansson@arm.com pkt->req->getSize(), 77811051Sandreas.hansson@arm.com pkt->req->getFlags(), 77911051Sandreas.hansson@arm.com pkt->req->masterId()); 78011051Sandreas.hansson@arm.com pf = new Packet(req, pkt->cmd); 78111051Sandreas.hansson@arm.com pf->allocate(); 78211051Sandreas.hansson@arm.com assert(pf->getAddr() == pkt->getAddr()); 78311051Sandreas.hansson@arm.com assert(pf->getSize() == pkt->getSize()); 78411051Sandreas.hansson@arm.com } 78511051Sandreas.hansson@arm.com 78611051Sandreas.hansson@arm.com pkt->makeTimingResponse(); 78711286Sandreas.hansson@arm.com 78811051Sandreas.hansson@arm.com // request_time is used here, taking into account lat and the delay 78911051Sandreas.hansson@arm.com // charged if the packet comes from the xbar. 79011194Sali.jafri@arm.com cpuSidePort->schedTimingResp(pkt, request_time, true); 79111051Sandreas.hansson@arm.com 79211051Sandreas.hansson@arm.com // If an outstanding request is in progress (we found an 79311051Sandreas.hansson@arm.com // MSHR) this is set to null 79411051Sandreas.hansson@arm.com pkt = pf; 79511051Sandreas.hansson@arm.com } 79611051Sandreas.hansson@arm.com 79711051Sandreas.hansson@arm.com if (mshr) { 79811051Sandreas.hansson@arm.com /// MSHR hit 79911051Sandreas.hansson@arm.com /// @note writebacks will be checked in getNextMSHR() 80011051Sandreas.hansson@arm.com /// for any conflicting requests to the same block 80111051Sandreas.hansson@arm.com 80211051Sandreas.hansson@arm.com //@todo remove hw_pf here 80311051Sandreas.hansson@arm.com 80411051Sandreas.hansson@arm.com // Coalesce unless it was a software prefetch (see above). 80511051Sandreas.hansson@arm.com if (pkt) { 80611199Sandreas.hansson@arm.com assert(!pkt->isWriteback()); 80711199Sandreas.hansson@arm.com // CleanEvicts corresponding to blocks which have 80811199Sandreas.hansson@arm.com // outstanding requests in MSHRs are simply sunk here 80911051Sandreas.hansson@arm.com if (pkt->cmd == MemCmd::CleanEvict) { 81011190Sandreas.hansson@arm.com pendingDelete.reset(pkt); 81111051Sandreas.hansson@arm.com } else { 81211483Snikos.nikoleris@arm.com DPRINTF(Cache, "%s coalescing MSHR for %s addr %#llx " 81311483Snikos.nikoleris@arm.com "size %d\n", __func__, pkt->cmdString(), 81411483Snikos.nikoleris@arm.com pkt->getAddr(), pkt->getSize()); 81511051Sandreas.hansson@arm.com 81611051Sandreas.hansson@arm.com assert(pkt->req->masterId() < system->maxMasters()); 81711051Sandreas.hansson@arm.com mshr_hits[pkt->cmdToIndex()][pkt->req->masterId()]++; 81811051Sandreas.hansson@arm.com // We use forward_time here because it is the same 81911051Sandreas.hansson@arm.com // considering new targets. We have multiple 82011051Sandreas.hansson@arm.com // requests for the same address here. It 82111051Sandreas.hansson@arm.com // specifies the latency to allocate an internal 82211051Sandreas.hansson@arm.com // buffer and to schedule an event to the queued 82311051Sandreas.hansson@arm.com // port and also takes into account the additional 82411051Sandreas.hansson@arm.com // delay of the xbar. 82511197Sandreas.hansson@arm.com mshr->allocateTarget(pkt, forward_time, order++, 82611197Sandreas.hansson@arm.com allocOnFill(pkt->cmd)); 82711051Sandreas.hansson@arm.com if (mshr->getNumTargets() == numTarget) { 82811051Sandreas.hansson@arm.com noTargetMSHR = mshr; 82911051Sandreas.hansson@arm.com setBlocked(Blocked_NoTargets); 83011051Sandreas.hansson@arm.com // need to be careful with this... if this mshr isn't 83111051Sandreas.hansson@arm.com // ready yet (i.e. time > curTick()), we don't want to 83211051Sandreas.hansson@arm.com // move it ahead of mshrs that are ready 83311051Sandreas.hansson@arm.com // mshrQueue.moveToFront(mshr); 83411051Sandreas.hansson@arm.com } 83511051Sandreas.hansson@arm.com } 83611051Sandreas.hansson@arm.com // We should call the prefetcher reguardless if the request is 83711483Snikos.nikoleris@arm.com // satisfied or not, reguardless if the request is in the MSHR 83811483Snikos.nikoleris@arm.com // or not. The request could be a ReadReq hit, but still not 83911051Sandreas.hansson@arm.com // satisfied (potentially because of a prior write to the same 84011051Sandreas.hansson@arm.com // cache line. So, even when not satisfied, tehre is an MSHR 84111483Snikos.nikoleris@arm.com // already allocated for this, we need to let the prefetcher 84211483Snikos.nikoleris@arm.com // know about the request 84311051Sandreas.hansson@arm.com if (prefetcher) { 84411051Sandreas.hansson@arm.com // Don't notify on SWPrefetch 84511051Sandreas.hansson@arm.com if (!pkt->cmd.isSWPrefetch()) 84611051Sandreas.hansson@arm.com next_pf_time = prefetcher->notify(pkt); 84711051Sandreas.hansson@arm.com } 84811051Sandreas.hansson@arm.com } 84911051Sandreas.hansson@arm.com } else { 85011051Sandreas.hansson@arm.com // no MSHR 85111051Sandreas.hansson@arm.com assert(pkt->req->masterId() < system->maxMasters()); 85211051Sandreas.hansson@arm.com if (pkt->req->isUncacheable()) { 85311051Sandreas.hansson@arm.com mshr_uncacheable[pkt->cmdToIndex()][pkt->req->masterId()]++; 85411051Sandreas.hansson@arm.com } else { 85511051Sandreas.hansson@arm.com mshr_misses[pkt->cmdToIndex()][pkt->req->masterId()]++; 85611051Sandreas.hansson@arm.com } 85711051Sandreas.hansson@arm.com 85811199Sandreas.hansson@arm.com if (pkt->isEviction() || 85911051Sandreas.hansson@arm.com (pkt->req->isUncacheable() && pkt->isWrite())) { 86011051Sandreas.hansson@arm.com // We use forward_time here because there is an 86111051Sandreas.hansson@arm.com // uncached memory write, forwarded to WriteBuffer. 86211051Sandreas.hansson@arm.com allocateWriteBuffer(pkt, forward_time); 86311051Sandreas.hansson@arm.com } else { 86411051Sandreas.hansson@arm.com if (blk && blk->isValid()) { 86511051Sandreas.hansson@arm.com // should have flushed and have no valid block 86611051Sandreas.hansson@arm.com assert(!pkt->req->isUncacheable()); 86711051Sandreas.hansson@arm.com 86811051Sandreas.hansson@arm.com // If we have a write miss to a valid block, we 86911051Sandreas.hansson@arm.com // need to mark the block non-readable. Otherwise 87011051Sandreas.hansson@arm.com // if we allow reads while there's an outstanding 87111051Sandreas.hansson@arm.com // write miss, the read could return stale data 87211051Sandreas.hansson@arm.com // out of the cache block... a more aggressive 87311051Sandreas.hansson@arm.com // system could detect the overlap (if any) and 87411051Sandreas.hansson@arm.com // forward data out of the MSHRs, but we don't do 87511051Sandreas.hansson@arm.com // that yet. Note that we do need to leave the 87611051Sandreas.hansson@arm.com // block valid so that it stays in the cache, in 87711051Sandreas.hansson@arm.com // case we get an upgrade response (and hence no 87811051Sandreas.hansson@arm.com // new data) when the write miss completes. 87911051Sandreas.hansson@arm.com // As long as CPUs do proper store/load forwarding 88011051Sandreas.hansson@arm.com // internally, and have a sufficiently weak memory 88111051Sandreas.hansson@arm.com // model, this is probably unnecessary, but at some 88211051Sandreas.hansson@arm.com // point it must have seemed like we needed it... 88311284Sandreas.hansson@arm.com assert(pkt->needsWritable()); 88411051Sandreas.hansson@arm.com assert(!blk->isWritable()); 88511051Sandreas.hansson@arm.com blk->status &= ~BlkReadable; 88611051Sandreas.hansson@arm.com } 88711051Sandreas.hansson@arm.com // Here we are using forward_time, modelling the latency of 88811051Sandreas.hansson@arm.com // a miss (outbound) just as forwardLatency, neglecting the 88911051Sandreas.hansson@arm.com // lookupLatency component. 89011051Sandreas.hansson@arm.com allocateMissBuffer(pkt, forward_time); 89111051Sandreas.hansson@arm.com } 89211051Sandreas.hansson@arm.com 89311051Sandreas.hansson@arm.com if (prefetcher) { 89411051Sandreas.hansson@arm.com // Don't notify on SWPrefetch 89511051Sandreas.hansson@arm.com if (!pkt->cmd.isSWPrefetch()) 89611051Sandreas.hansson@arm.com next_pf_time = prefetcher->notify(pkt); 89711051Sandreas.hansson@arm.com } 89811051Sandreas.hansson@arm.com } 89911051Sandreas.hansson@arm.com } 90011051Sandreas.hansson@arm.com 90111051Sandreas.hansson@arm.com if (next_pf_time != MaxTick) 90211051Sandreas.hansson@arm.com schedMemSideSendEvent(next_pf_time); 90311051Sandreas.hansson@arm.com 90411051Sandreas.hansson@arm.com return true; 90511051Sandreas.hansson@arm.com} 90611051Sandreas.hansson@arm.com 90711051Sandreas.hansson@arm.comPacketPtr 90811452Sandreas.hansson@arm.comCache::createMissPacket(PacketPtr cpu_pkt, CacheBlk *blk, 90911452Sandreas.hansson@arm.com bool needsWritable) const 91011051Sandreas.hansson@arm.com{ 91111452Sandreas.hansson@arm.com // should never see evictions here 91211452Sandreas.hansson@arm.com assert(!cpu_pkt->isEviction()); 91311452Sandreas.hansson@arm.com 91411051Sandreas.hansson@arm.com bool blkValid = blk && blk->isValid(); 91511051Sandreas.hansson@arm.com 91611452Sandreas.hansson@arm.com if (cpu_pkt->req->isUncacheable() || 91711452Sandreas.hansson@arm.com (!blkValid && cpu_pkt->isUpgrade())) { 91811452Sandreas.hansson@arm.com // uncacheable requests and upgrades from upper-level caches 91911452Sandreas.hansson@arm.com // that missed completely just go through as is 92011452Sandreas.hansson@arm.com return nullptr; 92111051Sandreas.hansson@arm.com } 92211051Sandreas.hansson@arm.com 92311051Sandreas.hansson@arm.com assert(cpu_pkt->needsResponse()); 92411051Sandreas.hansson@arm.com 92511051Sandreas.hansson@arm.com MemCmd cmd; 92611051Sandreas.hansson@arm.com // @TODO make useUpgrades a parameter. 92711051Sandreas.hansson@arm.com // Note that ownership protocols require upgrade, otherwise a 92811051Sandreas.hansson@arm.com // write miss on a shared owned block will generate a ReadExcl, 92911051Sandreas.hansson@arm.com // which will clobber the owned copy. 93011051Sandreas.hansson@arm.com const bool useUpgrades = true; 93111051Sandreas.hansson@arm.com if (blkValid && useUpgrades) { 93211284Sandreas.hansson@arm.com // only reason to be here is that blk is read only and we need 93311284Sandreas.hansson@arm.com // it to be writable 93411284Sandreas.hansson@arm.com assert(needsWritable); 93511051Sandreas.hansson@arm.com assert(!blk->isWritable()); 93611051Sandreas.hansson@arm.com cmd = cpu_pkt->isLLSC() ? MemCmd::SCUpgradeReq : MemCmd::UpgradeReq; 93711051Sandreas.hansson@arm.com } else if (cpu_pkt->cmd == MemCmd::SCUpgradeFailReq || 93811051Sandreas.hansson@arm.com cpu_pkt->cmd == MemCmd::StoreCondFailReq) { 93911051Sandreas.hansson@arm.com // Even though this SC will fail, we still need to send out the 94011051Sandreas.hansson@arm.com // request and get the data to supply it to other snoopers in the case 94111051Sandreas.hansson@arm.com // where the determination the StoreCond fails is delayed due to 94211051Sandreas.hansson@arm.com // all caches not being on the same local bus. 94311051Sandreas.hansson@arm.com cmd = MemCmd::SCUpgradeFailReq; 94411352Sandreas.hansson@arm.com } else if (cpu_pkt->cmd == MemCmd::WriteLineReq || 94511352Sandreas.hansson@arm.com cpu_pkt->cmd == MemCmd::InvalidateReq) { 94611051Sandreas.hansson@arm.com // forward as invalidate to all other caches, this gives us 94711284Sandreas.hansson@arm.com // the line in Exclusive state, and invalidates all other 94811051Sandreas.hansson@arm.com // copies 94911051Sandreas.hansson@arm.com cmd = MemCmd::InvalidateReq; 95011051Sandreas.hansson@arm.com } else { 95111051Sandreas.hansson@arm.com // block is invalid 95211284Sandreas.hansson@arm.com cmd = needsWritable ? MemCmd::ReadExReq : 95311051Sandreas.hansson@arm.com (isReadOnly ? MemCmd::ReadCleanReq : MemCmd::ReadSharedReq); 95411051Sandreas.hansson@arm.com } 95511051Sandreas.hansson@arm.com PacketPtr pkt = new Packet(cpu_pkt->req, cmd, blkSize); 95611051Sandreas.hansson@arm.com 95711284Sandreas.hansson@arm.com // if there are upstream caches that have already marked the 95811284Sandreas.hansson@arm.com // packet as having sharers (not passing writable), pass that info 95911284Sandreas.hansson@arm.com // downstream 96011284Sandreas.hansson@arm.com if (cpu_pkt->hasSharers()) { 96111051Sandreas.hansson@arm.com // note that cpu_pkt may have spent a considerable time in the 96211051Sandreas.hansson@arm.com // MSHR queue and that the information could possibly be out 96311051Sandreas.hansson@arm.com // of date, however, there is no harm in conservatively 96411284Sandreas.hansson@arm.com // assuming the block has sharers 96511284Sandreas.hansson@arm.com pkt->setHasSharers(); 96611284Sandreas.hansson@arm.com DPRINTF(Cache, "%s passing hasSharers from %s to %s addr %#llx " 96711284Sandreas.hansson@arm.com "size %d\n", 96811051Sandreas.hansson@arm.com __func__, cpu_pkt->cmdString(), pkt->cmdString(), 96911051Sandreas.hansson@arm.com pkt->getAddr(), pkt->getSize()); 97011051Sandreas.hansson@arm.com } 97111051Sandreas.hansson@arm.com 97211051Sandreas.hansson@arm.com // the packet should be block aligned 97311051Sandreas.hansson@arm.com assert(pkt->getAddr() == blockAlign(pkt->getAddr())); 97411051Sandreas.hansson@arm.com 97511051Sandreas.hansson@arm.com pkt->allocate(); 97611051Sandreas.hansson@arm.com DPRINTF(Cache, "%s created %s from %s for addr %#llx size %d\n", 97711051Sandreas.hansson@arm.com __func__, pkt->cmdString(), cpu_pkt->cmdString(), pkt->getAddr(), 97811051Sandreas.hansson@arm.com pkt->getSize()); 97911051Sandreas.hansson@arm.com return pkt; 98011051Sandreas.hansson@arm.com} 98111051Sandreas.hansson@arm.com 98211051Sandreas.hansson@arm.com 98311051Sandreas.hansson@arm.comTick 98411051Sandreas.hansson@arm.comCache::recvAtomic(PacketPtr pkt) 98511051Sandreas.hansson@arm.com{ 98611051Sandreas.hansson@arm.com // We are in atomic mode so we pay just for lookupLatency here. 98711051Sandreas.hansson@arm.com Cycles lat = lookupLatency; 98811051Sandreas.hansson@arm.com 98911051Sandreas.hansson@arm.com // Forward the request if the system is in cache bypass mode. 99011051Sandreas.hansson@arm.com if (system->bypassCaches()) 99111051Sandreas.hansson@arm.com return ticksToCycles(memSidePort->sendAtomic(pkt)); 99211051Sandreas.hansson@arm.com 99311051Sandreas.hansson@arm.com promoteWholeLineWrites(pkt); 99411051Sandreas.hansson@arm.com 99511333Sandreas.hansson@arm.com // follow the same flow as in recvTimingReq, and check if a cache 99611333Sandreas.hansson@arm.com // above us is responding 99711284Sandreas.hansson@arm.com if (pkt->cacheResponding()) { 99811333Sandreas.hansson@arm.com DPRINTF(Cache, "Cache above responding to %#llx (%s): " 99911333Sandreas.hansson@arm.com "not responding\n", 100011333Sandreas.hansson@arm.com pkt->getAddr(), pkt->isSecure() ? "s" : "ns"); 100111333Sandreas.hansson@arm.com 100211333Sandreas.hansson@arm.com // if a cache is responding, and it had the line in Owned 100311333Sandreas.hansson@arm.com // rather than Modified state, we need to invalidate any 100411333Sandreas.hansson@arm.com // copies that are not on the same path to memory 100511334Sandreas.hansson@arm.com assert(pkt->needsWritable() && !pkt->responderHadWritable()); 100611334Sandreas.hansson@arm.com lat += ticksToCycles(memSidePort->sendAtomic(pkt)); 100711051Sandreas.hansson@arm.com 100811051Sandreas.hansson@arm.com return lat * clockPeriod(); 100911051Sandreas.hansson@arm.com } 101011051Sandreas.hansson@arm.com 101111051Sandreas.hansson@arm.com // should assert here that there are no outstanding MSHRs or 101211051Sandreas.hansson@arm.com // writebacks... that would mean that someone used an atomic 101311051Sandreas.hansson@arm.com // access in timing mode 101411051Sandreas.hansson@arm.com 101511484Snikos.nikoleris@arm.com CacheBlk *blk = nullptr; 101611051Sandreas.hansson@arm.com PacketList writebacks; 101711051Sandreas.hansson@arm.com bool satisfied = access(pkt, blk, lat, writebacks); 101811051Sandreas.hansson@arm.com 101911051Sandreas.hansson@arm.com // handle writebacks resulting from the access here to ensure they 102011051Sandreas.hansson@arm.com // logically proceed anything happening below 102111130Sali.jafri@arm.com doWritebacksAtomic(writebacks); 102211051Sandreas.hansson@arm.com 102311051Sandreas.hansson@arm.com if (!satisfied) { 102411051Sandreas.hansson@arm.com // MISS 102511051Sandreas.hansson@arm.com 102611452Sandreas.hansson@arm.com // deal with the packets that go through the write path of 102711452Sandreas.hansson@arm.com // the cache, i.e. any evictions and uncacheable writes 102811452Sandreas.hansson@arm.com if (pkt->isEviction() || 102911452Sandreas.hansson@arm.com (pkt->req->isUncacheable() && pkt->isWrite())) { 103011452Sandreas.hansson@arm.com lat += ticksToCycles(memSidePort->sendAtomic(pkt)); 103111452Sandreas.hansson@arm.com return lat * clockPeriod(); 103211452Sandreas.hansson@arm.com } 103311452Sandreas.hansson@arm.com // only misses left 103411452Sandreas.hansson@arm.com 103511452Sandreas.hansson@arm.com PacketPtr bus_pkt = createMissPacket(pkt, blk, pkt->needsWritable()); 103611051Sandreas.hansson@arm.com 103711484Snikos.nikoleris@arm.com bool is_forward = (bus_pkt == nullptr); 103811051Sandreas.hansson@arm.com 103911051Sandreas.hansson@arm.com if (is_forward) { 104011051Sandreas.hansson@arm.com // just forwarding the same request to the next level 104111051Sandreas.hansson@arm.com // no local cache operation involved 104211051Sandreas.hansson@arm.com bus_pkt = pkt; 104311051Sandreas.hansson@arm.com } 104411051Sandreas.hansson@arm.com 104511051Sandreas.hansson@arm.com DPRINTF(Cache, "Sending an atomic %s for %#llx (%s)\n", 104611051Sandreas.hansson@arm.com bus_pkt->cmdString(), bus_pkt->getAddr(), 104711051Sandreas.hansson@arm.com bus_pkt->isSecure() ? "s" : "ns"); 104811051Sandreas.hansson@arm.com 104911051Sandreas.hansson@arm.com#if TRACING_ON 105011051Sandreas.hansson@arm.com CacheBlk::State old_state = blk ? blk->status : 0; 105111051Sandreas.hansson@arm.com#endif 105211051Sandreas.hansson@arm.com 105311051Sandreas.hansson@arm.com lat += ticksToCycles(memSidePort->sendAtomic(bus_pkt)); 105411051Sandreas.hansson@arm.com 105511452Sandreas.hansson@arm.com bool is_invalidate = bus_pkt->isInvalidate(); 105611452Sandreas.hansson@arm.com 105711051Sandreas.hansson@arm.com // We are now dealing with the response handling 105811483Snikos.nikoleris@arm.com DPRINTF(Cache, "Receive response: %s for addr %#llx (%s) in " 105911483Snikos.nikoleris@arm.com "state %i\n", bus_pkt->cmdString(), bus_pkt->getAddr(), 106011051Sandreas.hansson@arm.com bus_pkt->isSecure() ? "s" : "ns", 106111051Sandreas.hansson@arm.com old_state); 106211051Sandreas.hansson@arm.com 106311051Sandreas.hansson@arm.com // If packet was a forward, the response (if any) is already 106411051Sandreas.hansson@arm.com // in place in the bus_pkt == pkt structure, so we don't need 106511051Sandreas.hansson@arm.com // to do anything. Otherwise, use the separate bus_pkt to 106611051Sandreas.hansson@arm.com // generate response to pkt and then delete it. 106711051Sandreas.hansson@arm.com if (!is_forward) { 106811051Sandreas.hansson@arm.com if (pkt->needsResponse()) { 106911051Sandreas.hansson@arm.com assert(bus_pkt->isResponse()); 107011051Sandreas.hansson@arm.com if (bus_pkt->isError()) { 107111051Sandreas.hansson@arm.com pkt->makeAtomicResponse(); 107211051Sandreas.hansson@arm.com pkt->copyError(bus_pkt); 107311051Sandreas.hansson@arm.com } else if (pkt->cmd == MemCmd::WriteLineReq) { 107411051Sandreas.hansson@arm.com // note the use of pkt, not bus_pkt here. 107511051Sandreas.hansson@arm.com 107611051Sandreas.hansson@arm.com // write-line request to the cache that promoted 107711051Sandreas.hansson@arm.com // the write to a whole line 107811197Sandreas.hansson@arm.com blk = handleFill(pkt, blk, writebacks, 107911197Sandreas.hansson@arm.com allocOnFill(pkt->cmd)); 108011452Sandreas.hansson@arm.com assert(blk != NULL); 108111452Sandreas.hansson@arm.com is_invalidate = false; 108211051Sandreas.hansson@arm.com satisfyCpuSideRequest(pkt, blk); 108311051Sandreas.hansson@arm.com } else if (bus_pkt->isRead() || 108411051Sandreas.hansson@arm.com bus_pkt->cmd == MemCmd::UpgradeResp) { 108511051Sandreas.hansson@arm.com // we're updating cache state to allow us to 108611051Sandreas.hansson@arm.com // satisfy the upstream request from the cache 108711197Sandreas.hansson@arm.com blk = handleFill(bus_pkt, blk, writebacks, 108811197Sandreas.hansson@arm.com allocOnFill(pkt->cmd)); 108911051Sandreas.hansson@arm.com satisfyCpuSideRequest(pkt, blk); 109011051Sandreas.hansson@arm.com } else { 109111051Sandreas.hansson@arm.com // we're satisfying the upstream request without 109211051Sandreas.hansson@arm.com // modifying cache state, e.g., a write-through 109311051Sandreas.hansson@arm.com pkt->makeAtomicResponse(); 109411051Sandreas.hansson@arm.com } 109511051Sandreas.hansson@arm.com } 109611051Sandreas.hansson@arm.com delete bus_pkt; 109711051Sandreas.hansson@arm.com } 109811452Sandreas.hansson@arm.com 109911452Sandreas.hansson@arm.com if (is_invalidate && blk && blk->isValid()) { 110011452Sandreas.hansson@arm.com invalidateBlock(blk); 110111452Sandreas.hansson@arm.com } 110211051Sandreas.hansson@arm.com } 110311051Sandreas.hansson@arm.com 110411051Sandreas.hansson@arm.com // Note that we don't invoke the prefetcher at all in atomic mode. 110511051Sandreas.hansson@arm.com // It's not clear how to do it properly, particularly for 110611051Sandreas.hansson@arm.com // prefetchers that aggressively generate prefetch candidates and 110711051Sandreas.hansson@arm.com // rely on bandwidth contention to throttle them; these will tend 110811051Sandreas.hansson@arm.com // to pollute the cache in atomic mode since there is no bandwidth 110911051Sandreas.hansson@arm.com // contention. If we ever do want to enable prefetching in atomic 111011051Sandreas.hansson@arm.com // mode, though, this is the place to do it... see timingAccess() 111111051Sandreas.hansson@arm.com // for an example (though we'd want to issue the prefetch(es) 111211051Sandreas.hansson@arm.com // immediately rather than calling requestMemSideBus() as we do 111311051Sandreas.hansson@arm.com // there). 111411051Sandreas.hansson@arm.com 111511197Sandreas.hansson@arm.com // do any writebacks resulting from the response handling 111611130Sali.jafri@arm.com doWritebacksAtomic(writebacks); 111711051Sandreas.hansson@arm.com 111811197Sandreas.hansson@arm.com // if we used temp block, check to see if its valid and if so 111911197Sandreas.hansson@arm.com // clear it out, but only do so after the call to recvAtomic is 112011197Sandreas.hansson@arm.com // finished so that any downstream observers (such as a snoop 112111197Sandreas.hansson@arm.com // filter), first see the fill, and only then see the eviction 112211197Sandreas.hansson@arm.com if (blk == tempBlock && tempBlock->isValid()) { 112311197Sandreas.hansson@arm.com // the atomic CPU calls recvAtomic for fetch and load/store 112411197Sandreas.hansson@arm.com // sequentuially, and we may already have a tempBlock 112511197Sandreas.hansson@arm.com // writeback from the fetch that we have not yet sent 112611197Sandreas.hansson@arm.com if (tempBlockWriteback) { 112711197Sandreas.hansson@arm.com // if that is the case, write the prevoius one back, and 112811197Sandreas.hansson@arm.com // do not schedule any new event 112911197Sandreas.hansson@arm.com writebackTempBlockAtomic(); 113011197Sandreas.hansson@arm.com } else { 113111197Sandreas.hansson@arm.com // the writeback/clean eviction happens after the call to 113211197Sandreas.hansson@arm.com // recvAtomic has finished (but before any successive 113311197Sandreas.hansson@arm.com // calls), so that the response handling from the fill is 113411197Sandreas.hansson@arm.com // allowed to happen first 113511197Sandreas.hansson@arm.com schedule(writebackTempBlockAtomicEvent, curTick()); 113611197Sandreas.hansson@arm.com } 113711197Sandreas.hansson@arm.com 113811199Sandreas.hansson@arm.com tempBlockWriteback = (blk->isDirty() || writebackClean) ? 113911199Sandreas.hansson@arm.com writebackBlk(blk) : cleanEvictBlk(blk); 114011197Sandreas.hansson@arm.com blk->invalidate(); 114111197Sandreas.hansson@arm.com } 114211197Sandreas.hansson@arm.com 114311051Sandreas.hansson@arm.com if (pkt->needsResponse()) { 114411051Sandreas.hansson@arm.com pkt->makeAtomicResponse(); 114511051Sandreas.hansson@arm.com } 114611051Sandreas.hansson@arm.com 114711051Sandreas.hansson@arm.com return lat * clockPeriod(); 114811051Sandreas.hansson@arm.com} 114911051Sandreas.hansson@arm.com 115011051Sandreas.hansson@arm.com 115111051Sandreas.hansson@arm.comvoid 115211051Sandreas.hansson@arm.comCache::functionalAccess(PacketPtr pkt, bool fromCpuSide) 115311051Sandreas.hansson@arm.com{ 115411051Sandreas.hansson@arm.com if (system->bypassCaches()) { 115511051Sandreas.hansson@arm.com // Packets from the memory side are snoop request and 115611051Sandreas.hansson@arm.com // shouldn't happen in bypass mode. 115711051Sandreas.hansson@arm.com assert(fromCpuSide); 115811051Sandreas.hansson@arm.com 115911051Sandreas.hansson@arm.com // The cache should be flushed if we are in cache bypass mode, 116011051Sandreas.hansson@arm.com // so we don't need to check if we need to update anything. 116111051Sandreas.hansson@arm.com memSidePort->sendFunctional(pkt); 116211051Sandreas.hansson@arm.com return; 116311051Sandreas.hansson@arm.com } 116411051Sandreas.hansson@arm.com 116511051Sandreas.hansson@arm.com Addr blk_addr = blockAlign(pkt->getAddr()); 116611051Sandreas.hansson@arm.com bool is_secure = pkt->isSecure(); 116711051Sandreas.hansson@arm.com CacheBlk *blk = tags->findBlock(pkt->getAddr(), is_secure); 116811051Sandreas.hansson@arm.com MSHR *mshr = mshrQueue.findMatch(blk_addr, is_secure); 116911051Sandreas.hansson@arm.com 117011051Sandreas.hansson@arm.com pkt->pushLabel(name()); 117111051Sandreas.hansson@arm.com 117211051Sandreas.hansson@arm.com CacheBlkPrintWrapper cbpw(blk); 117311051Sandreas.hansson@arm.com 117411051Sandreas.hansson@arm.com // Note that just because an L2/L3 has valid data doesn't mean an 117511051Sandreas.hansson@arm.com // L1 doesn't have a more up-to-date modified copy that still 117611051Sandreas.hansson@arm.com // needs to be found. As a result we always update the request if 117711051Sandreas.hansson@arm.com // we have it, but only declare it satisfied if we are the owner. 117811051Sandreas.hansson@arm.com 117911051Sandreas.hansson@arm.com // see if we have data at all (owned or otherwise) 118011051Sandreas.hansson@arm.com bool have_data = blk && blk->isValid() 118111051Sandreas.hansson@arm.com && pkt->checkFunctional(&cbpw, blk_addr, is_secure, blkSize, 118211051Sandreas.hansson@arm.com blk->data); 118311051Sandreas.hansson@arm.com 118411284Sandreas.hansson@arm.com // data we have is dirty if marked as such or if we have an 118511284Sandreas.hansson@arm.com // in-service MSHR that is pending a modified line 118611051Sandreas.hansson@arm.com bool have_dirty = 118711051Sandreas.hansson@arm.com have_data && (blk->isDirty() || 118811284Sandreas.hansson@arm.com (mshr && mshr->inService && mshr->isPendingModified())); 118911051Sandreas.hansson@arm.com 119011051Sandreas.hansson@arm.com bool done = have_dirty 119111051Sandreas.hansson@arm.com || cpuSidePort->checkFunctional(pkt) 119211051Sandreas.hansson@arm.com || mshrQueue.checkFunctional(pkt, blk_addr) 119311051Sandreas.hansson@arm.com || writeBuffer.checkFunctional(pkt, blk_addr) 119411051Sandreas.hansson@arm.com || memSidePort->checkFunctional(pkt); 119511051Sandreas.hansson@arm.com 119611288Ssteve.reinhardt@amd.com DPRINTF(CacheVerbose, "functional %s %#llx (%s) %s%s%s\n", 119711051Sandreas.hansson@arm.com pkt->cmdString(), pkt->getAddr(), is_secure ? "s" : "ns", 119811051Sandreas.hansson@arm.com (blk && blk->isValid()) ? "valid " : "", 119911051Sandreas.hansson@arm.com have_data ? "data " : "", done ? "done " : ""); 120011051Sandreas.hansson@arm.com 120111051Sandreas.hansson@arm.com // We're leaving the cache, so pop cache->name() label 120211051Sandreas.hansson@arm.com pkt->popLabel(); 120311051Sandreas.hansson@arm.com 120411051Sandreas.hansson@arm.com if (done) { 120511051Sandreas.hansson@arm.com pkt->makeResponse(); 120611051Sandreas.hansson@arm.com } else { 120711051Sandreas.hansson@arm.com // if it came as a request from the CPU side then make sure it 120811051Sandreas.hansson@arm.com // continues towards the memory side 120911051Sandreas.hansson@arm.com if (fromCpuSide) { 121011051Sandreas.hansson@arm.com memSidePort->sendFunctional(pkt); 121111485Snikos.nikoleris@arm.com } else if (cpuSidePort->isSnooping()) { 121211051Sandreas.hansson@arm.com // if it came from the memory side, it must be a snoop request 121311051Sandreas.hansson@arm.com // and we should only forward it if we are forwarding snoops 121411051Sandreas.hansson@arm.com cpuSidePort->sendFunctionalSnoop(pkt); 121511051Sandreas.hansson@arm.com } 121611051Sandreas.hansson@arm.com } 121711051Sandreas.hansson@arm.com} 121811051Sandreas.hansson@arm.com 121911051Sandreas.hansson@arm.com 122011051Sandreas.hansson@arm.com///////////////////////////////////////////////////// 122111051Sandreas.hansson@arm.com// 122211051Sandreas.hansson@arm.com// Response handling: responses from the memory side 122311051Sandreas.hansson@arm.com// 122411051Sandreas.hansson@arm.com///////////////////////////////////////////////////// 122511051Sandreas.hansson@arm.com 122611051Sandreas.hansson@arm.com 122711051Sandreas.hansson@arm.comvoid 122811375Sandreas.hansson@arm.comCache::handleUncacheableWriteResp(PacketPtr pkt) 122911375Sandreas.hansson@arm.com{ 123011375Sandreas.hansson@arm.com Tick completion_time = clockEdge(responseLatency) + 123111375Sandreas.hansson@arm.com pkt->headerDelay + pkt->payloadDelay; 123211375Sandreas.hansson@arm.com 123311453Sandreas.hansson@arm.com // Reset the bus additional time as it is now accounted for 123411453Sandreas.hansson@arm.com pkt->headerDelay = pkt->payloadDelay = 0; 123511375Sandreas.hansson@arm.com 123611453Sandreas.hansson@arm.com cpuSidePort->schedTimingResp(pkt, completion_time, true); 123711375Sandreas.hansson@arm.com} 123811375Sandreas.hansson@arm.com 123911375Sandreas.hansson@arm.comvoid 124011051Sandreas.hansson@arm.comCache::recvTimingResp(PacketPtr pkt) 124111051Sandreas.hansson@arm.com{ 124211051Sandreas.hansson@arm.com assert(pkt->isResponse()); 124311051Sandreas.hansson@arm.com 124411051Sandreas.hansson@arm.com // all header delay should be paid for by the crossbar, unless 124511051Sandreas.hansson@arm.com // this is a prefetch response from above 124611051Sandreas.hansson@arm.com panic_if(pkt->headerDelay != 0 && pkt->cmd != MemCmd::HardPFResp, 124711051Sandreas.hansson@arm.com "%s saw a non-zero packet delay\n", name()); 124811051Sandreas.hansson@arm.com 124911051Sandreas.hansson@arm.com bool is_error = pkt->isError(); 125011051Sandreas.hansson@arm.com 125111051Sandreas.hansson@arm.com if (is_error) { 125211051Sandreas.hansson@arm.com DPRINTF(Cache, "Cache received packet with error for addr %#llx (%s), " 125311051Sandreas.hansson@arm.com "cmd: %s\n", pkt->getAddr(), pkt->isSecure() ? "s" : "ns", 125411051Sandreas.hansson@arm.com pkt->cmdString()); 125511051Sandreas.hansson@arm.com } 125611051Sandreas.hansson@arm.com 125711051Sandreas.hansson@arm.com DPRINTF(Cache, "Handling response %s for addr %#llx size %d (%s)\n", 125811051Sandreas.hansson@arm.com pkt->cmdString(), pkt->getAddr(), pkt->getSize(), 125911051Sandreas.hansson@arm.com pkt->isSecure() ? "s" : "ns"); 126011051Sandreas.hansson@arm.com 126111375Sandreas.hansson@arm.com // if this is a write, we should be looking at an uncacheable 126211375Sandreas.hansson@arm.com // write 126311375Sandreas.hansson@arm.com if (pkt->isWrite()) { 126411375Sandreas.hansson@arm.com assert(pkt->req->isUncacheable()); 126511375Sandreas.hansson@arm.com handleUncacheableWriteResp(pkt); 126611375Sandreas.hansson@arm.com return; 126711375Sandreas.hansson@arm.com } 126811375Sandreas.hansson@arm.com 126911375Sandreas.hansson@arm.com // we have dealt with any (uncacheable) writes above, from here on 127011375Sandreas.hansson@arm.com // we know we are dealing with an MSHR due to a miss or a prefetch 127111453Sandreas.hansson@arm.com MSHR *mshr = dynamic_cast<MSHR*>(pkt->popSenderState()); 127211375Sandreas.hansson@arm.com assert(mshr); 127311051Sandreas.hansson@arm.com 127411051Sandreas.hansson@arm.com if (mshr == noTargetMSHR) { 127511051Sandreas.hansson@arm.com // we always clear at least one target 127611051Sandreas.hansson@arm.com clearBlocked(Blocked_NoTargets); 127711484Snikos.nikoleris@arm.com noTargetMSHR = nullptr; 127811051Sandreas.hansson@arm.com } 127911051Sandreas.hansson@arm.com 128011051Sandreas.hansson@arm.com // Initial target is used just for stats 128111051Sandreas.hansson@arm.com MSHR::Target *initial_tgt = mshr->getTarget(); 128211051Sandreas.hansson@arm.com int stats_cmd_idx = initial_tgt->pkt->cmdToIndex(); 128311051Sandreas.hansson@arm.com Tick miss_latency = curTick() - initial_tgt->recvTime; 128411051Sandreas.hansson@arm.com 128511051Sandreas.hansson@arm.com if (pkt->req->isUncacheable()) { 128611051Sandreas.hansson@arm.com assert(pkt->req->masterId() < system->maxMasters()); 128711051Sandreas.hansson@arm.com mshr_uncacheable_lat[stats_cmd_idx][pkt->req->masterId()] += 128811051Sandreas.hansson@arm.com miss_latency; 128911051Sandreas.hansson@arm.com } else { 129011051Sandreas.hansson@arm.com assert(pkt->req->masterId() < system->maxMasters()); 129111051Sandreas.hansson@arm.com mshr_miss_latency[stats_cmd_idx][pkt->req->masterId()] += 129211051Sandreas.hansson@arm.com miss_latency; 129311051Sandreas.hansson@arm.com } 129411051Sandreas.hansson@arm.com 129511375Sandreas.hansson@arm.com bool wasFull = mshrQueue.isFull(); 129611375Sandreas.hansson@arm.com 129711375Sandreas.hansson@arm.com PacketList writebacks; 129811375Sandreas.hansson@arm.com 129911375Sandreas.hansson@arm.com Tick forward_time = clockEdge(forwardLatency) + pkt->headerDelay; 130011375Sandreas.hansson@arm.com 130111284Sandreas.hansson@arm.com // upgrade deferred targets if the response has no sharers, and is 130211284Sandreas.hansson@arm.com // thus passing writable 130311284Sandreas.hansson@arm.com if (!pkt->hasSharers()) { 130411284Sandreas.hansson@arm.com mshr->promoteWritable(); 130511177Sandreas.hansson@arm.com } 130611177Sandreas.hansson@arm.com 130711051Sandreas.hansson@arm.com bool is_fill = !mshr->isForward && 130811051Sandreas.hansson@arm.com (pkt->isRead() || pkt->cmd == MemCmd::UpgradeResp); 130911051Sandreas.hansson@arm.com 131011177Sandreas.hansson@arm.com CacheBlk *blk = tags->findBlock(pkt->getAddr(), pkt->isSecure()); 131111177Sandreas.hansson@arm.com 131211051Sandreas.hansson@arm.com if (is_fill && !is_error) { 131311051Sandreas.hansson@arm.com DPRINTF(Cache, "Block for addr %#llx being updated in Cache\n", 131411051Sandreas.hansson@arm.com pkt->getAddr()); 131511051Sandreas.hansson@arm.com 131611197Sandreas.hansson@arm.com blk = handleFill(pkt, blk, writebacks, mshr->allocOnFill); 131711484Snikos.nikoleris@arm.com assert(blk != nullptr); 131811051Sandreas.hansson@arm.com } 131911051Sandreas.hansson@arm.com 132011051Sandreas.hansson@arm.com // allow invalidation responses originating from write-line 132111051Sandreas.hansson@arm.com // requests to be discarded 132211136Sandreas.hansson@arm.com bool is_invalidate = pkt->isInvalidate(); 132311051Sandreas.hansson@arm.com 132411051Sandreas.hansson@arm.com // First offset for critical word first calculations 132511051Sandreas.hansson@arm.com int initial_offset = initial_tgt->pkt->getOffset(blkSize); 132611051Sandreas.hansson@arm.com 132711051Sandreas.hansson@arm.com while (mshr->hasTargets()) { 132811051Sandreas.hansson@arm.com MSHR::Target *target = mshr->getTarget(); 132911051Sandreas.hansson@arm.com Packet *tgt_pkt = target->pkt; 133011051Sandreas.hansson@arm.com 133111051Sandreas.hansson@arm.com switch (target->source) { 133211051Sandreas.hansson@arm.com case MSHR::Target::FromCPU: 133311051Sandreas.hansson@arm.com Tick completion_time; 133411051Sandreas.hansson@arm.com // Here we charge on completion_time the delay of the xbar if the 133511051Sandreas.hansson@arm.com // packet comes from it, charged on headerDelay. 133611051Sandreas.hansson@arm.com completion_time = pkt->headerDelay; 133711051Sandreas.hansson@arm.com 133811051Sandreas.hansson@arm.com // Software prefetch handling for cache closest to core 133911051Sandreas.hansson@arm.com if (tgt_pkt->cmd.isSWPrefetch()) { 134011483Snikos.nikoleris@arm.com // a software prefetch would have already been ack'd 134111483Snikos.nikoleris@arm.com // immediately with dummy data so the core would be able to 134211483Snikos.nikoleris@arm.com // retire it. This request completes right here, so we 134311483Snikos.nikoleris@arm.com // deallocate it. 134411051Sandreas.hansson@arm.com delete tgt_pkt->req; 134511051Sandreas.hansson@arm.com delete tgt_pkt; 134611051Sandreas.hansson@arm.com break; // skip response 134711051Sandreas.hansson@arm.com } 134811051Sandreas.hansson@arm.com 134911051Sandreas.hansson@arm.com // unlike the other packet flows, where data is found in other 135011051Sandreas.hansson@arm.com // caches or memory and brought back, write-line requests always 135111051Sandreas.hansson@arm.com // have the data right away, so the above check for "is fill?" 135211051Sandreas.hansson@arm.com // cannot actually be determined until examining the stored MSHR 135311051Sandreas.hansson@arm.com // state. We "catch up" with that logic here, which is duplicated 135411051Sandreas.hansson@arm.com // from above. 135511051Sandreas.hansson@arm.com if (tgt_pkt->cmd == MemCmd::WriteLineReq) { 135611051Sandreas.hansson@arm.com assert(!is_error); 135711284Sandreas.hansson@arm.com // we got the block in a writable state, so promote 135811284Sandreas.hansson@arm.com // any deferred targets if possible 135911284Sandreas.hansson@arm.com mshr->promoteWritable(); 136011051Sandreas.hansson@arm.com // NB: we use the original packet here and not the response! 136111197Sandreas.hansson@arm.com blk = handleFill(tgt_pkt, blk, writebacks, mshr->allocOnFill); 136211484Snikos.nikoleris@arm.com assert(blk != nullptr); 136311051Sandreas.hansson@arm.com 136411051Sandreas.hansson@arm.com // treat as a fill, and discard the invalidation 136511051Sandreas.hansson@arm.com // response 136611051Sandreas.hansson@arm.com is_fill = true; 136711136Sandreas.hansson@arm.com is_invalidate = false; 136811051Sandreas.hansson@arm.com } 136911051Sandreas.hansson@arm.com 137011051Sandreas.hansson@arm.com if (is_fill) { 137111051Sandreas.hansson@arm.com satisfyCpuSideRequest(tgt_pkt, blk, 137211051Sandreas.hansson@arm.com true, mshr->hasPostDowngrade()); 137311051Sandreas.hansson@arm.com 137411051Sandreas.hansson@arm.com // How many bytes past the first request is this one 137511051Sandreas.hansson@arm.com int transfer_offset = 137611051Sandreas.hansson@arm.com tgt_pkt->getOffset(blkSize) - initial_offset; 137711051Sandreas.hansson@arm.com if (transfer_offset < 0) { 137811051Sandreas.hansson@arm.com transfer_offset += blkSize; 137911051Sandreas.hansson@arm.com } 138011051Sandreas.hansson@arm.com 138111051Sandreas.hansson@arm.com // If not critical word (offset) return payloadDelay. 138211051Sandreas.hansson@arm.com // responseLatency is the latency of the return path 138311051Sandreas.hansson@arm.com // from lower level caches/memory to an upper level cache or 138411051Sandreas.hansson@arm.com // the core. 138511051Sandreas.hansson@arm.com completion_time += clockEdge(responseLatency) + 138611051Sandreas.hansson@arm.com (transfer_offset ? pkt->payloadDelay : 0); 138711051Sandreas.hansson@arm.com 138811051Sandreas.hansson@arm.com assert(!tgt_pkt->req->isUncacheable()); 138911051Sandreas.hansson@arm.com 139011051Sandreas.hansson@arm.com assert(tgt_pkt->req->masterId() < system->maxMasters()); 139111051Sandreas.hansson@arm.com missLatency[tgt_pkt->cmdToIndex()][tgt_pkt->req->masterId()] += 139211051Sandreas.hansson@arm.com completion_time - target->recvTime; 139311051Sandreas.hansson@arm.com } else if (pkt->cmd == MemCmd::UpgradeFailResp) { 139411051Sandreas.hansson@arm.com // failed StoreCond upgrade 139511051Sandreas.hansson@arm.com assert(tgt_pkt->cmd == MemCmd::StoreCondReq || 139611051Sandreas.hansson@arm.com tgt_pkt->cmd == MemCmd::StoreCondFailReq || 139711051Sandreas.hansson@arm.com tgt_pkt->cmd == MemCmd::SCUpgradeFailReq); 139811051Sandreas.hansson@arm.com // responseLatency is the latency of the return path 139911051Sandreas.hansson@arm.com // from lower level caches/memory to an upper level cache or 140011051Sandreas.hansson@arm.com // the core. 140111051Sandreas.hansson@arm.com completion_time += clockEdge(responseLatency) + 140211051Sandreas.hansson@arm.com pkt->payloadDelay; 140311051Sandreas.hansson@arm.com tgt_pkt->req->setExtraData(0); 140411051Sandreas.hansson@arm.com } else { 140511051Sandreas.hansson@arm.com // not a cache fill, just forwarding response 140611051Sandreas.hansson@arm.com // responseLatency is the latency of the return path 140711051Sandreas.hansson@arm.com // from lower level cahces/memory to the core. 140811051Sandreas.hansson@arm.com completion_time += clockEdge(responseLatency) + 140911051Sandreas.hansson@arm.com pkt->payloadDelay; 141011051Sandreas.hansson@arm.com if (pkt->isRead() && !is_error) { 141111051Sandreas.hansson@arm.com // sanity check 141211051Sandreas.hansson@arm.com assert(pkt->getAddr() == tgt_pkt->getAddr()); 141311051Sandreas.hansson@arm.com assert(pkt->getSize() >= tgt_pkt->getSize()); 141411051Sandreas.hansson@arm.com 141511051Sandreas.hansson@arm.com tgt_pkt->setData(pkt->getConstPtr<uint8_t>()); 141611051Sandreas.hansson@arm.com } 141711051Sandreas.hansson@arm.com } 141811051Sandreas.hansson@arm.com tgt_pkt->makeTimingResponse(); 141911051Sandreas.hansson@arm.com // if this packet is an error copy that to the new packet 142011051Sandreas.hansson@arm.com if (is_error) 142111051Sandreas.hansson@arm.com tgt_pkt->copyError(pkt); 142211051Sandreas.hansson@arm.com if (tgt_pkt->cmd == MemCmd::ReadResp && 142311136Sandreas.hansson@arm.com (is_invalidate || mshr->hasPostInvalidate())) { 142411051Sandreas.hansson@arm.com // If intermediate cache got ReadRespWithInvalidate, 142511051Sandreas.hansson@arm.com // propagate that. Response should not have 142611051Sandreas.hansson@arm.com // isInvalidate() set otherwise. 142711051Sandreas.hansson@arm.com tgt_pkt->cmd = MemCmd::ReadRespWithInvalidate; 142811051Sandreas.hansson@arm.com DPRINTF(Cache, "%s updated cmd to %s for addr %#llx\n", 142911051Sandreas.hansson@arm.com __func__, tgt_pkt->cmdString(), tgt_pkt->getAddr()); 143011051Sandreas.hansson@arm.com } 143111051Sandreas.hansson@arm.com // Reset the bus additional time as it is now accounted for 143211051Sandreas.hansson@arm.com tgt_pkt->headerDelay = tgt_pkt->payloadDelay = 0; 143311194Sali.jafri@arm.com cpuSidePort->schedTimingResp(tgt_pkt, completion_time, true); 143411051Sandreas.hansson@arm.com break; 143511051Sandreas.hansson@arm.com 143611051Sandreas.hansson@arm.com case MSHR::Target::FromPrefetcher: 143711051Sandreas.hansson@arm.com assert(tgt_pkt->cmd == MemCmd::HardPFReq); 143811051Sandreas.hansson@arm.com if (blk) 143911051Sandreas.hansson@arm.com blk->status |= BlkHWPrefetched; 144011051Sandreas.hansson@arm.com delete tgt_pkt->req; 144111051Sandreas.hansson@arm.com delete tgt_pkt; 144211051Sandreas.hansson@arm.com break; 144311051Sandreas.hansson@arm.com 144411051Sandreas.hansson@arm.com case MSHR::Target::FromSnoop: 144511051Sandreas.hansson@arm.com // I don't believe that a snoop can be in an error state 144611051Sandreas.hansson@arm.com assert(!is_error); 144711051Sandreas.hansson@arm.com // response to snoop request 144811051Sandreas.hansson@arm.com DPRINTF(Cache, "processing deferred snoop...\n"); 144911136Sandreas.hansson@arm.com assert(!(is_invalidate && !mshr->hasPostInvalidate())); 145011051Sandreas.hansson@arm.com handleSnoop(tgt_pkt, blk, true, true, mshr->hasPostInvalidate()); 145111051Sandreas.hansson@arm.com break; 145211051Sandreas.hansson@arm.com 145311051Sandreas.hansson@arm.com default: 145411051Sandreas.hansson@arm.com panic("Illegal target->source enum %d\n", target->source); 145511051Sandreas.hansson@arm.com } 145611051Sandreas.hansson@arm.com 145711051Sandreas.hansson@arm.com mshr->popTarget(); 145811051Sandreas.hansson@arm.com } 145911051Sandreas.hansson@arm.com 146011051Sandreas.hansson@arm.com if (blk && blk->isValid()) { 146111051Sandreas.hansson@arm.com // an invalidate response stemming from a write line request 146211051Sandreas.hansson@arm.com // should not invalidate the block, so check if the 146311051Sandreas.hansson@arm.com // invalidation should be discarded 146411136Sandreas.hansson@arm.com if (is_invalidate || mshr->hasPostInvalidate()) { 146511197Sandreas.hansson@arm.com invalidateBlock(blk); 146611051Sandreas.hansson@arm.com } else if (mshr->hasPostDowngrade()) { 146711051Sandreas.hansson@arm.com blk->status &= ~BlkWritable; 146811051Sandreas.hansson@arm.com } 146911051Sandreas.hansson@arm.com } 147011051Sandreas.hansson@arm.com 147111051Sandreas.hansson@arm.com if (mshr->promoteDeferredTargets()) { 147211051Sandreas.hansson@arm.com // avoid later read getting stale data while write miss is 147311051Sandreas.hansson@arm.com // outstanding.. see comment in timingAccess() 147411051Sandreas.hansson@arm.com if (blk) { 147511051Sandreas.hansson@arm.com blk->status &= ~BlkReadable; 147611051Sandreas.hansson@arm.com } 147711375Sandreas.hansson@arm.com mshrQueue.markPending(mshr); 147811051Sandreas.hansson@arm.com schedMemSideSendEvent(clockEdge() + pkt->payloadDelay); 147911051Sandreas.hansson@arm.com } else { 148011375Sandreas.hansson@arm.com mshrQueue.deallocate(mshr); 148111375Sandreas.hansson@arm.com if (wasFull && !mshrQueue.isFull()) { 148211375Sandreas.hansson@arm.com clearBlocked(Blocked_NoMSHRs); 148311051Sandreas.hansson@arm.com } 148411051Sandreas.hansson@arm.com 148511051Sandreas.hansson@arm.com // Request the bus for a prefetch if this deallocation freed enough 148611051Sandreas.hansson@arm.com // MSHRs for a prefetch to take place 148711375Sandreas.hansson@arm.com if (prefetcher && mshrQueue.canPrefetch()) { 148811051Sandreas.hansson@arm.com Tick next_pf_time = std::max(prefetcher->nextPrefetchReadyTime(), 148911051Sandreas.hansson@arm.com clockEdge()); 149011051Sandreas.hansson@arm.com if (next_pf_time != MaxTick) 149111051Sandreas.hansson@arm.com schedMemSideSendEvent(next_pf_time); 149211051Sandreas.hansson@arm.com } 149311051Sandreas.hansson@arm.com } 149411051Sandreas.hansson@arm.com // reset the xbar additional timinig as it is now accounted for 149511051Sandreas.hansson@arm.com pkt->headerDelay = pkt->payloadDelay = 0; 149611051Sandreas.hansson@arm.com 149711051Sandreas.hansson@arm.com // copy writebacks to write buffer 149811051Sandreas.hansson@arm.com doWritebacks(writebacks, forward_time); 149911051Sandreas.hansson@arm.com 150011051Sandreas.hansson@arm.com // if we used temp block, check to see if its valid and then clear it out 150111051Sandreas.hansson@arm.com if (blk == tempBlock && tempBlock->isValid()) { 150211051Sandreas.hansson@arm.com // We use forwardLatency here because we are copying 150311051Sandreas.hansson@arm.com // Writebacks/CleanEvicts to write buffer. It specifies the latency to 150411051Sandreas.hansson@arm.com // allocate an internal buffer and to schedule an event to the 150511051Sandreas.hansson@arm.com // queued port. 150611199Sandreas.hansson@arm.com if (blk->isDirty() || writebackClean) { 150711051Sandreas.hansson@arm.com PacketPtr wbPkt = writebackBlk(blk); 150811051Sandreas.hansson@arm.com allocateWriteBuffer(wbPkt, forward_time); 150911051Sandreas.hansson@arm.com // Set BLOCK_CACHED flag if cached above. 151011051Sandreas.hansson@arm.com if (isCachedAbove(wbPkt)) 151111051Sandreas.hansson@arm.com wbPkt->setBlockCached(); 151211051Sandreas.hansson@arm.com } else { 151311051Sandreas.hansson@arm.com PacketPtr wcPkt = cleanEvictBlk(blk); 151411051Sandreas.hansson@arm.com // Check to see if block is cached above. If not allocate 151511051Sandreas.hansson@arm.com // write buffer 151611051Sandreas.hansson@arm.com if (isCachedAbove(wcPkt)) 151711051Sandreas.hansson@arm.com delete wcPkt; 151811051Sandreas.hansson@arm.com else 151911051Sandreas.hansson@arm.com allocateWriteBuffer(wcPkt, forward_time); 152011051Sandreas.hansson@arm.com } 152111051Sandreas.hansson@arm.com blk->invalidate(); 152211051Sandreas.hansson@arm.com } 152311051Sandreas.hansson@arm.com 152411288Ssteve.reinhardt@amd.com DPRINTF(CacheVerbose, "Leaving %s with %s for addr %#llx\n", __func__, 152511051Sandreas.hansson@arm.com pkt->cmdString(), pkt->getAddr()); 152611051Sandreas.hansson@arm.com delete pkt; 152711051Sandreas.hansson@arm.com} 152811051Sandreas.hansson@arm.com 152911051Sandreas.hansson@arm.comPacketPtr 153011051Sandreas.hansson@arm.comCache::writebackBlk(CacheBlk *blk) 153111051Sandreas.hansson@arm.com{ 153211199Sandreas.hansson@arm.com chatty_assert(!isReadOnly || writebackClean, 153311199Sandreas.hansson@arm.com "Writeback from read-only cache"); 153411199Sandreas.hansson@arm.com assert(blk && blk->isValid() && (blk->isDirty() || writebackClean)); 153511051Sandreas.hansson@arm.com 153611051Sandreas.hansson@arm.com writebacks[Request::wbMasterId]++; 153711051Sandreas.hansson@arm.com 153811199Sandreas.hansson@arm.com Request *req = new Request(tags->regenerateBlkAddr(blk->tag, blk->set), 153911199Sandreas.hansson@arm.com blkSize, 0, Request::wbMasterId); 154011051Sandreas.hansson@arm.com if (blk->isSecure()) 154111199Sandreas.hansson@arm.com req->setFlags(Request::SECURE); 154211051Sandreas.hansson@arm.com 154311199Sandreas.hansson@arm.com req->taskId(blk->task_id); 154411051Sandreas.hansson@arm.com blk->task_id= ContextSwitchTaskId::Unknown; 154511051Sandreas.hansson@arm.com blk->tickInserted = curTick(); 154611051Sandreas.hansson@arm.com 154711199Sandreas.hansson@arm.com PacketPtr pkt = 154811199Sandreas.hansson@arm.com new Packet(req, blk->isDirty() ? 154911199Sandreas.hansson@arm.com MemCmd::WritebackDirty : MemCmd::WritebackClean); 155011199Sandreas.hansson@arm.com 155111199Sandreas.hansson@arm.com DPRINTF(Cache, "Create Writeback %#llx writable: %d, dirty: %d\n", 155211199Sandreas.hansson@arm.com pkt->getAddr(), blk->isWritable(), blk->isDirty()); 155311199Sandreas.hansson@arm.com 155411051Sandreas.hansson@arm.com if (blk->isWritable()) { 155511051Sandreas.hansson@arm.com // not asserting shared means we pass the block in modified 155611051Sandreas.hansson@arm.com // state, mark our own block non-writeable 155711051Sandreas.hansson@arm.com blk->status &= ~BlkWritable; 155811051Sandreas.hansson@arm.com } else { 155911284Sandreas.hansson@arm.com // we are in the Owned state, tell the receiver 156011284Sandreas.hansson@arm.com pkt->setHasSharers(); 156111051Sandreas.hansson@arm.com } 156211051Sandreas.hansson@arm.com 156311199Sandreas.hansson@arm.com // make sure the block is not marked dirty 156411199Sandreas.hansson@arm.com blk->status &= ~BlkDirty; 156511051Sandreas.hansson@arm.com 156611199Sandreas.hansson@arm.com pkt->allocate(); 156711199Sandreas.hansson@arm.com std::memcpy(pkt->getPtr<uint8_t>(), blk->data, blkSize); 156811199Sandreas.hansson@arm.com 156911199Sandreas.hansson@arm.com return pkt; 157011051Sandreas.hansson@arm.com} 157111051Sandreas.hansson@arm.com 157211051Sandreas.hansson@arm.comPacketPtr 157311051Sandreas.hansson@arm.comCache::cleanEvictBlk(CacheBlk *blk) 157411051Sandreas.hansson@arm.com{ 157511199Sandreas.hansson@arm.com assert(!writebackClean); 157611051Sandreas.hansson@arm.com assert(blk && blk->isValid() && !blk->isDirty()); 157711051Sandreas.hansson@arm.com // Creating a zero sized write, a message to the snoop filter 157811051Sandreas.hansson@arm.com Request *req = 157911051Sandreas.hansson@arm.com new Request(tags->regenerateBlkAddr(blk->tag, blk->set), blkSize, 0, 158011051Sandreas.hansson@arm.com Request::wbMasterId); 158111051Sandreas.hansson@arm.com if (blk->isSecure()) 158211051Sandreas.hansson@arm.com req->setFlags(Request::SECURE); 158311051Sandreas.hansson@arm.com 158411051Sandreas.hansson@arm.com req->taskId(blk->task_id); 158511051Sandreas.hansson@arm.com blk->task_id = ContextSwitchTaskId::Unknown; 158611051Sandreas.hansson@arm.com blk->tickInserted = curTick(); 158711051Sandreas.hansson@arm.com 158811051Sandreas.hansson@arm.com PacketPtr pkt = new Packet(req, MemCmd::CleanEvict); 158911051Sandreas.hansson@arm.com pkt->allocate(); 159011051Sandreas.hansson@arm.com DPRINTF(Cache, "%s%s %x Create CleanEvict\n", pkt->cmdString(), 159111051Sandreas.hansson@arm.com pkt->req->isInstFetch() ? " (ifetch)" : "", 159211051Sandreas.hansson@arm.com pkt->getAddr()); 159311051Sandreas.hansson@arm.com 159411051Sandreas.hansson@arm.com return pkt; 159511051Sandreas.hansson@arm.com} 159611051Sandreas.hansson@arm.com 159711051Sandreas.hansson@arm.comvoid 159811051Sandreas.hansson@arm.comCache::memWriteback() 159911051Sandreas.hansson@arm.com{ 160011051Sandreas.hansson@arm.com CacheBlkVisitorWrapper visitor(*this, &Cache::writebackVisitor); 160111051Sandreas.hansson@arm.com tags->forEachBlk(visitor); 160211051Sandreas.hansson@arm.com} 160311051Sandreas.hansson@arm.com 160411051Sandreas.hansson@arm.comvoid 160511051Sandreas.hansson@arm.comCache::memInvalidate() 160611051Sandreas.hansson@arm.com{ 160711051Sandreas.hansson@arm.com CacheBlkVisitorWrapper visitor(*this, &Cache::invalidateVisitor); 160811051Sandreas.hansson@arm.com tags->forEachBlk(visitor); 160911051Sandreas.hansson@arm.com} 161011051Sandreas.hansson@arm.com 161111051Sandreas.hansson@arm.combool 161211051Sandreas.hansson@arm.comCache::isDirty() const 161311051Sandreas.hansson@arm.com{ 161411051Sandreas.hansson@arm.com CacheBlkIsDirtyVisitor visitor; 161511051Sandreas.hansson@arm.com tags->forEachBlk(visitor); 161611051Sandreas.hansson@arm.com 161711051Sandreas.hansson@arm.com return visitor.isDirty(); 161811051Sandreas.hansson@arm.com} 161911051Sandreas.hansson@arm.com 162011051Sandreas.hansson@arm.combool 162111051Sandreas.hansson@arm.comCache::writebackVisitor(CacheBlk &blk) 162211051Sandreas.hansson@arm.com{ 162311051Sandreas.hansson@arm.com if (blk.isDirty()) { 162411051Sandreas.hansson@arm.com assert(blk.isValid()); 162511051Sandreas.hansson@arm.com 162611051Sandreas.hansson@arm.com Request request(tags->regenerateBlkAddr(blk.tag, blk.set), 162711051Sandreas.hansson@arm.com blkSize, 0, Request::funcMasterId); 162811051Sandreas.hansson@arm.com request.taskId(blk.task_id); 162911051Sandreas.hansson@arm.com 163011051Sandreas.hansson@arm.com Packet packet(&request, MemCmd::WriteReq); 163111051Sandreas.hansson@arm.com packet.dataStatic(blk.data); 163211051Sandreas.hansson@arm.com 163311051Sandreas.hansson@arm.com memSidePort->sendFunctional(&packet); 163411051Sandreas.hansson@arm.com 163511051Sandreas.hansson@arm.com blk.status &= ~BlkDirty; 163611051Sandreas.hansson@arm.com } 163711051Sandreas.hansson@arm.com 163811051Sandreas.hansson@arm.com return true; 163911051Sandreas.hansson@arm.com} 164011051Sandreas.hansson@arm.com 164111051Sandreas.hansson@arm.combool 164211051Sandreas.hansson@arm.comCache::invalidateVisitor(CacheBlk &blk) 164311051Sandreas.hansson@arm.com{ 164411051Sandreas.hansson@arm.com 164511051Sandreas.hansson@arm.com if (blk.isDirty()) 164611051Sandreas.hansson@arm.com warn_once("Invalidating dirty cache lines. Expect things to break.\n"); 164711051Sandreas.hansson@arm.com 164811051Sandreas.hansson@arm.com if (blk.isValid()) { 164911051Sandreas.hansson@arm.com assert(!blk.isDirty()); 165011051Sandreas.hansson@arm.com tags->invalidate(&blk); 165111051Sandreas.hansson@arm.com blk.invalidate(); 165211051Sandreas.hansson@arm.com } 165311051Sandreas.hansson@arm.com 165411051Sandreas.hansson@arm.com return true; 165511051Sandreas.hansson@arm.com} 165611051Sandreas.hansson@arm.com 165711051Sandreas.hansson@arm.comCacheBlk* 165811051Sandreas.hansson@arm.comCache::allocateBlock(Addr addr, bool is_secure, PacketList &writebacks) 165911051Sandreas.hansson@arm.com{ 166011051Sandreas.hansson@arm.com CacheBlk *blk = tags->findVictim(addr); 166111051Sandreas.hansson@arm.com 166211484Snikos.nikoleris@arm.com // It is valid to return nullptr if there is no victim 166311051Sandreas.hansson@arm.com if (!blk) 166411051Sandreas.hansson@arm.com return nullptr; 166511051Sandreas.hansson@arm.com 166611051Sandreas.hansson@arm.com if (blk->isValid()) { 166711051Sandreas.hansson@arm.com Addr repl_addr = tags->regenerateBlkAddr(blk->tag, blk->set); 166811051Sandreas.hansson@arm.com MSHR *repl_mshr = mshrQueue.findMatch(repl_addr, blk->isSecure()); 166911051Sandreas.hansson@arm.com if (repl_mshr) { 167011051Sandreas.hansson@arm.com // must be an outstanding upgrade request 167111051Sandreas.hansson@arm.com // on a block we're about to replace... 167211051Sandreas.hansson@arm.com assert(!blk->isWritable() || blk->isDirty()); 167311284Sandreas.hansson@arm.com assert(repl_mshr->needsWritable()); 167411051Sandreas.hansson@arm.com // too hard to replace block with transient state 167511051Sandreas.hansson@arm.com // allocation failed, block not inserted 167611484Snikos.nikoleris@arm.com return nullptr; 167711051Sandreas.hansson@arm.com } else { 167811483Snikos.nikoleris@arm.com DPRINTF(Cache, "replacement: replacing %#llx (%s) with %#llx " 167911483Snikos.nikoleris@arm.com "(%s): %s\n", repl_addr, blk->isSecure() ? "s" : "ns", 168011051Sandreas.hansson@arm.com addr, is_secure ? "s" : "ns", 168111051Sandreas.hansson@arm.com blk->isDirty() ? "writeback" : "clean"); 168211051Sandreas.hansson@arm.com 168311436SRekai.GonzalezAlberquilla@arm.com if (blk->wasPrefetched()) { 168411436SRekai.GonzalezAlberquilla@arm.com unusedPrefetches++; 168511436SRekai.GonzalezAlberquilla@arm.com } 168611051Sandreas.hansson@arm.com // Will send up Writeback/CleanEvict snoops via isCachedAbove 168711051Sandreas.hansson@arm.com // when pushing this writeback list into the write buffer. 168811199Sandreas.hansson@arm.com if (blk->isDirty() || writebackClean) { 168911051Sandreas.hansson@arm.com // Save writeback packet for handling by caller 169011051Sandreas.hansson@arm.com writebacks.push_back(writebackBlk(blk)); 169111051Sandreas.hansson@arm.com } else { 169211051Sandreas.hansson@arm.com writebacks.push_back(cleanEvictBlk(blk)); 169311051Sandreas.hansson@arm.com } 169411051Sandreas.hansson@arm.com } 169511051Sandreas.hansson@arm.com } 169611051Sandreas.hansson@arm.com 169711051Sandreas.hansson@arm.com return blk; 169811051Sandreas.hansson@arm.com} 169911051Sandreas.hansson@arm.com 170011197Sandreas.hansson@arm.comvoid 170111197Sandreas.hansson@arm.comCache::invalidateBlock(CacheBlk *blk) 170211197Sandreas.hansson@arm.com{ 170311197Sandreas.hansson@arm.com if (blk != tempBlock) 170411197Sandreas.hansson@arm.com tags->invalidate(blk); 170511197Sandreas.hansson@arm.com blk->invalidate(); 170611197Sandreas.hansson@arm.com} 170711051Sandreas.hansson@arm.com 170811051Sandreas.hansson@arm.com// Note that the reason we return a list of writebacks rather than 170911051Sandreas.hansson@arm.com// inserting them directly in the write buffer is that this function 171011051Sandreas.hansson@arm.com// is called by both atomic and timing-mode accesses, and in atomic 171111051Sandreas.hansson@arm.com// mode we don't mess with the write buffer (we just perform the 171211051Sandreas.hansson@arm.com// writebacks atomically once the original request is complete). 171311051Sandreas.hansson@arm.comCacheBlk* 171411197Sandreas.hansson@arm.comCache::handleFill(PacketPtr pkt, CacheBlk *blk, PacketList &writebacks, 171511197Sandreas.hansson@arm.com bool allocate) 171611051Sandreas.hansson@arm.com{ 171711051Sandreas.hansson@arm.com assert(pkt->isResponse() || pkt->cmd == MemCmd::WriteLineReq); 171811051Sandreas.hansson@arm.com Addr addr = pkt->getAddr(); 171911051Sandreas.hansson@arm.com bool is_secure = pkt->isSecure(); 172011051Sandreas.hansson@arm.com#if TRACING_ON 172111051Sandreas.hansson@arm.com CacheBlk::State old_state = blk ? blk->status : 0; 172211051Sandreas.hansson@arm.com#endif 172311051Sandreas.hansson@arm.com 172411375Sandreas.hansson@arm.com // When handling a fill, we should have no writes to this line. 172511375Sandreas.hansson@arm.com assert(addr == blockAlign(addr)); 172611375Sandreas.hansson@arm.com assert(!writeBuffer.findMatch(addr, is_secure)); 172711051Sandreas.hansson@arm.com 172811484Snikos.nikoleris@arm.com if (blk == nullptr) { 172911051Sandreas.hansson@arm.com // better have read new data... 173011051Sandreas.hansson@arm.com assert(pkt->hasData()); 173111051Sandreas.hansson@arm.com 173211051Sandreas.hansson@arm.com // only read responses and write-line requests have data; 173311051Sandreas.hansson@arm.com // note that we don't write the data here for write-line - that 173411051Sandreas.hansson@arm.com // happens in the subsequent satisfyCpuSideRequest. 173511051Sandreas.hansson@arm.com assert(pkt->isRead() || pkt->cmd == MemCmd::WriteLineReq); 173611051Sandreas.hansson@arm.com 173711197Sandreas.hansson@arm.com // need to do a replacement if allocating, otherwise we stick 173811197Sandreas.hansson@arm.com // with the temporary storage 173911484Snikos.nikoleris@arm.com blk = allocate ? allocateBlock(addr, is_secure, writebacks) : nullptr; 174011197Sandreas.hansson@arm.com 174111484Snikos.nikoleris@arm.com if (blk == nullptr) { 174211197Sandreas.hansson@arm.com // No replaceable block or a mostly exclusive 174311197Sandreas.hansson@arm.com // cache... just use temporary storage to complete the 174411197Sandreas.hansson@arm.com // current request and then get rid of it 174511051Sandreas.hansson@arm.com assert(!tempBlock->isValid()); 174611051Sandreas.hansson@arm.com blk = tempBlock; 174711051Sandreas.hansson@arm.com tempBlock->set = tags->extractSet(addr); 174811051Sandreas.hansson@arm.com tempBlock->tag = tags->extractTag(addr); 174911051Sandreas.hansson@arm.com // @todo: set security state as well... 175011051Sandreas.hansson@arm.com DPRINTF(Cache, "using temp block for %#llx (%s)\n", addr, 175111051Sandreas.hansson@arm.com is_secure ? "s" : "ns"); 175211051Sandreas.hansson@arm.com } else { 175311051Sandreas.hansson@arm.com tags->insertBlock(pkt, blk); 175411051Sandreas.hansson@arm.com } 175511051Sandreas.hansson@arm.com 175611051Sandreas.hansson@arm.com // we should never be overwriting a valid block 175711051Sandreas.hansson@arm.com assert(!blk->isValid()); 175811051Sandreas.hansson@arm.com } else { 175911051Sandreas.hansson@arm.com // existing block... probably an upgrade 176011051Sandreas.hansson@arm.com assert(blk->tag == tags->extractTag(addr)); 176111051Sandreas.hansson@arm.com // either we're getting new data or the block should already be valid 176211051Sandreas.hansson@arm.com assert(pkt->hasData() || blk->isValid()); 176311051Sandreas.hansson@arm.com // don't clear block status... if block is already dirty we 176411051Sandreas.hansson@arm.com // don't want to lose that 176511051Sandreas.hansson@arm.com } 176611051Sandreas.hansson@arm.com 176711051Sandreas.hansson@arm.com if (is_secure) 176811051Sandreas.hansson@arm.com blk->status |= BlkSecure; 176911051Sandreas.hansson@arm.com blk->status |= BlkValid | BlkReadable; 177011051Sandreas.hansson@arm.com 177111137Sandreas.hansson@arm.com // sanity check for whole-line writes, which should always be 177211137Sandreas.hansson@arm.com // marked as writable as part of the fill, and then later marked 177311137Sandreas.hansson@arm.com // dirty as part of satisfyCpuSideRequest 177411137Sandreas.hansson@arm.com if (pkt->cmd == MemCmd::WriteLineReq) { 177511284Sandreas.hansson@arm.com assert(!pkt->hasSharers()); 177611137Sandreas.hansson@arm.com // at the moment other caches do not respond to the 177711137Sandreas.hansson@arm.com // invalidation requests corresponding to a whole-line write 177811284Sandreas.hansson@arm.com assert(!pkt->cacheResponding()); 177911137Sandreas.hansson@arm.com } 178011137Sandreas.hansson@arm.com 178111284Sandreas.hansson@arm.com // here we deal with setting the appropriate state of the line, 178211284Sandreas.hansson@arm.com // and we start by looking at the hasSharers flag, and ignore the 178311284Sandreas.hansson@arm.com // cacheResponding flag (normally signalling dirty data) if the 178411284Sandreas.hansson@arm.com // packet has sharers, thus the line is never allocated as Owned 178511284Sandreas.hansson@arm.com // (dirty but not writable), and always ends up being either 178611284Sandreas.hansson@arm.com // Shared, Exclusive or Modified, see Packet::setCacheResponding 178711284Sandreas.hansson@arm.com // for more details 178811284Sandreas.hansson@arm.com if (!pkt->hasSharers()) { 178911284Sandreas.hansson@arm.com // we could get a writable line from memory (rather than a 179011284Sandreas.hansson@arm.com // cache) even in a read-only cache, note that we set this bit 179111284Sandreas.hansson@arm.com // even for a read-only cache, possibly revisit this decision 179211051Sandreas.hansson@arm.com blk->status |= BlkWritable; 179311051Sandreas.hansson@arm.com 179411284Sandreas.hansson@arm.com // check if we got this via cache-to-cache transfer (i.e., from a 179511284Sandreas.hansson@arm.com // cache that had the block in Modified or Owned state) 179611284Sandreas.hansson@arm.com if (pkt->cacheResponding()) { 179711284Sandreas.hansson@arm.com // we got the block in Modified state, and invalidated the 179811284Sandreas.hansson@arm.com // owners copy 179911051Sandreas.hansson@arm.com blk->status |= BlkDirty; 180011051Sandreas.hansson@arm.com 180111051Sandreas.hansson@arm.com chatty_assert(!isReadOnly, "Should never see dirty snoop response " 180211051Sandreas.hansson@arm.com "in read-only cache %s\n", name()); 180311051Sandreas.hansson@arm.com } 180411051Sandreas.hansson@arm.com } 180511051Sandreas.hansson@arm.com 180611051Sandreas.hansson@arm.com DPRINTF(Cache, "Block addr %#llx (%s) moving from state %x to %s\n", 180711051Sandreas.hansson@arm.com addr, is_secure ? "s" : "ns", old_state, blk->print()); 180811051Sandreas.hansson@arm.com 180911051Sandreas.hansson@arm.com // if we got new data, copy it in (checking for a read response 181011051Sandreas.hansson@arm.com // and a response that has data is the same in the end) 181111051Sandreas.hansson@arm.com if (pkt->isRead()) { 181211051Sandreas.hansson@arm.com // sanity checks 181311051Sandreas.hansson@arm.com assert(pkt->hasData()); 181411051Sandreas.hansson@arm.com assert(pkt->getSize() == blkSize); 181511051Sandreas.hansson@arm.com 181611051Sandreas.hansson@arm.com std::memcpy(blk->data, pkt->getConstPtr<uint8_t>(), blkSize); 181711051Sandreas.hansson@arm.com } 181811051Sandreas.hansson@arm.com // We pay for fillLatency here. 181911051Sandreas.hansson@arm.com blk->whenReady = clockEdge() + fillLatency * clockPeriod() + 182011051Sandreas.hansson@arm.com pkt->payloadDelay; 182111051Sandreas.hansson@arm.com 182211051Sandreas.hansson@arm.com return blk; 182311051Sandreas.hansson@arm.com} 182411051Sandreas.hansson@arm.com 182511051Sandreas.hansson@arm.com 182611051Sandreas.hansson@arm.com///////////////////////////////////////////////////// 182711051Sandreas.hansson@arm.com// 182811051Sandreas.hansson@arm.com// Snoop path: requests coming in from the memory side 182911051Sandreas.hansson@arm.com// 183011051Sandreas.hansson@arm.com///////////////////////////////////////////////////// 183111051Sandreas.hansson@arm.com 183211051Sandreas.hansson@arm.comvoid 183311051Sandreas.hansson@arm.comCache::doTimingSupplyResponse(PacketPtr req_pkt, const uint8_t *blk_data, 183411051Sandreas.hansson@arm.com bool already_copied, bool pending_inval) 183511051Sandreas.hansson@arm.com{ 183611051Sandreas.hansson@arm.com // sanity check 183711051Sandreas.hansson@arm.com assert(req_pkt->isRequest()); 183811051Sandreas.hansson@arm.com assert(req_pkt->needsResponse()); 183911051Sandreas.hansson@arm.com 184011051Sandreas.hansson@arm.com DPRINTF(Cache, "%s for %s addr %#llx size %d\n", __func__, 184111051Sandreas.hansson@arm.com req_pkt->cmdString(), req_pkt->getAddr(), req_pkt->getSize()); 184211051Sandreas.hansson@arm.com // timing-mode snoop responses require a new packet, unless we 184311051Sandreas.hansson@arm.com // already made a copy... 184411051Sandreas.hansson@arm.com PacketPtr pkt = req_pkt; 184511051Sandreas.hansson@arm.com if (!already_copied) 184611051Sandreas.hansson@arm.com // do not clear flags, and allocate space for data if the 184711051Sandreas.hansson@arm.com // packet needs it (the only packets that carry data are read 184811051Sandreas.hansson@arm.com // responses) 184911051Sandreas.hansson@arm.com pkt = new Packet(req_pkt, false, req_pkt->isRead()); 185011051Sandreas.hansson@arm.com 185111051Sandreas.hansson@arm.com assert(req_pkt->req->isUncacheable() || req_pkt->isInvalidate() || 185211284Sandreas.hansson@arm.com pkt->hasSharers()); 185311051Sandreas.hansson@arm.com pkt->makeTimingResponse(); 185411051Sandreas.hansson@arm.com if (pkt->isRead()) { 185511051Sandreas.hansson@arm.com pkt->setDataFromBlock(blk_data, blkSize); 185611051Sandreas.hansson@arm.com } 185711051Sandreas.hansson@arm.com if (pkt->cmd == MemCmd::ReadResp && pending_inval) { 185811051Sandreas.hansson@arm.com // Assume we defer a response to a read from a far-away cache 185911051Sandreas.hansson@arm.com // A, then later defer a ReadExcl from a cache B on the same 186011284Sandreas.hansson@arm.com // bus as us. We'll assert cacheResponding in both cases, but 186111284Sandreas.hansson@arm.com // in the latter case cacheResponding will keep the 186211284Sandreas.hansson@arm.com // invalidation from reaching cache A. This special response 186311284Sandreas.hansson@arm.com // tells cache A that it gets the block to satisfy its read, 186411284Sandreas.hansson@arm.com // but must immediately invalidate it. 186511051Sandreas.hansson@arm.com pkt->cmd = MemCmd::ReadRespWithInvalidate; 186611051Sandreas.hansson@arm.com } 186711051Sandreas.hansson@arm.com // Here we consider forward_time, paying for just forward latency and 186811051Sandreas.hansson@arm.com // also charging the delay provided by the xbar. 186911051Sandreas.hansson@arm.com // forward_time is used as send_time in next allocateWriteBuffer(). 187011051Sandreas.hansson@arm.com Tick forward_time = clockEdge(forwardLatency) + pkt->headerDelay; 187111051Sandreas.hansson@arm.com // Here we reset the timing of the packet. 187211051Sandreas.hansson@arm.com pkt->headerDelay = pkt->payloadDelay = 0; 187311288Ssteve.reinhardt@amd.com DPRINTF(CacheVerbose, 187411288Ssteve.reinhardt@amd.com "%s created response: %s addr %#llx size %d tick: %lu\n", 187511051Sandreas.hansson@arm.com __func__, pkt->cmdString(), pkt->getAddr(), pkt->getSize(), 187611051Sandreas.hansson@arm.com forward_time); 187711051Sandreas.hansson@arm.com memSidePort->schedTimingSnoopResp(pkt, forward_time, true); 187811051Sandreas.hansson@arm.com} 187911051Sandreas.hansson@arm.com 188011127Sandreas.hansson@arm.comuint32_t 188111051Sandreas.hansson@arm.comCache::handleSnoop(PacketPtr pkt, CacheBlk *blk, bool is_timing, 188211051Sandreas.hansson@arm.com bool is_deferred, bool pending_inval) 188311051Sandreas.hansson@arm.com{ 188411288Ssteve.reinhardt@amd.com DPRINTF(CacheVerbose, "%s for %s addr %#llx size %d\n", __func__, 188511051Sandreas.hansson@arm.com pkt->cmdString(), pkt->getAddr(), pkt->getSize()); 188611051Sandreas.hansson@arm.com // deferred snoops can only happen in timing mode 188711051Sandreas.hansson@arm.com assert(!(is_deferred && !is_timing)); 188811051Sandreas.hansson@arm.com // pending_inval only makes sense on deferred snoops 188911051Sandreas.hansson@arm.com assert(!(pending_inval && !is_deferred)); 189011051Sandreas.hansson@arm.com assert(pkt->isRequest()); 189111051Sandreas.hansson@arm.com 189211051Sandreas.hansson@arm.com // the packet may get modified if we or a forwarded snooper 189311051Sandreas.hansson@arm.com // responds in atomic mode, so remember a few things about the 189411051Sandreas.hansson@arm.com // original packet up front 189511051Sandreas.hansson@arm.com bool invalidate = pkt->isInvalidate(); 189611284Sandreas.hansson@arm.com bool M5_VAR_USED needs_writable = pkt->needsWritable(); 189711051Sandreas.hansson@arm.com 189811285Sandreas.hansson@arm.com // at the moment we could get an uncacheable write which does not 189911285Sandreas.hansson@arm.com // have the invalidate flag, and we need a suitable way of dealing 190011285Sandreas.hansson@arm.com // with this case 190111285Sandreas.hansson@arm.com panic_if(invalidate && pkt->req->isUncacheable(), 190211285Sandreas.hansson@arm.com "%s got an invalidating uncacheable snoop request %s to %#llx", 190311285Sandreas.hansson@arm.com name(), pkt->cmdString(), pkt->getAddr()); 190411285Sandreas.hansson@arm.com 190511127Sandreas.hansson@arm.com uint32_t snoop_delay = 0; 190611127Sandreas.hansson@arm.com 190711051Sandreas.hansson@arm.com if (forwardSnoops) { 190811051Sandreas.hansson@arm.com // first propagate snoop upward to see if anyone above us wants to 190911051Sandreas.hansson@arm.com // handle it. save & restore packet src since it will get 191011051Sandreas.hansson@arm.com // rewritten to be relative to cpu-side bus (if any) 191111284Sandreas.hansson@arm.com bool alreadyResponded = pkt->cacheResponding(); 191211051Sandreas.hansson@arm.com if (is_timing) { 191311051Sandreas.hansson@arm.com // copy the packet so that we can clear any flags before 191411051Sandreas.hansson@arm.com // forwarding it upwards, we also allocate data (passing 191511051Sandreas.hansson@arm.com // the pointer along in case of static data), in case 191611051Sandreas.hansson@arm.com // there is a snoop hit in upper levels 191711051Sandreas.hansson@arm.com Packet snoopPkt(pkt, true, true); 191811051Sandreas.hansson@arm.com snoopPkt.setExpressSnoop(); 191911051Sandreas.hansson@arm.com // the snoop packet does not need to wait any additional 192011051Sandreas.hansson@arm.com // time 192111051Sandreas.hansson@arm.com snoopPkt.headerDelay = snoopPkt.payloadDelay = 0; 192211051Sandreas.hansson@arm.com cpuSidePort->sendTimingSnoopReq(&snoopPkt); 192311127Sandreas.hansson@arm.com 192411127Sandreas.hansson@arm.com // add the header delay (including crossbar and snoop 192511127Sandreas.hansson@arm.com // delays) of the upward snoop to the snoop delay for this 192611127Sandreas.hansson@arm.com // cache 192711127Sandreas.hansson@arm.com snoop_delay += snoopPkt.headerDelay; 192811127Sandreas.hansson@arm.com 192911284Sandreas.hansson@arm.com if (snoopPkt.cacheResponding()) { 193011051Sandreas.hansson@arm.com // cache-to-cache response from some upper cache 193111051Sandreas.hansson@arm.com assert(!alreadyResponded); 193211284Sandreas.hansson@arm.com pkt->setCacheResponding(); 193311051Sandreas.hansson@arm.com } 193411284Sandreas.hansson@arm.com // upstream cache has the block, or has an outstanding 193511284Sandreas.hansson@arm.com // MSHR, pass the flag on 193611284Sandreas.hansson@arm.com if (snoopPkt.hasSharers()) { 193711284Sandreas.hansson@arm.com pkt->setHasSharers(); 193811051Sandreas.hansson@arm.com } 193911051Sandreas.hansson@arm.com // If this request is a prefetch or clean evict and an upper level 194011051Sandreas.hansson@arm.com // signals block present, make sure to propagate the block 194111051Sandreas.hansson@arm.com // presence to the requester. 194211051Sandreas.hansson@arm.com if (snoopPkt.isBlockCached()) { 194311051Sandreas.hansson@arm.com pkt->setBlockCached(); 194411051Sandreas.hansson@arm.com } 194511051Sandreas.hansson@arm.com } else { 194611051Sandreas.hansson@arm.com cpuSidePort->sendAtomicSnoop(pkt); 194711284Sandreas.hansson@arm.com if (!alreadyResponded && pkt->cacheResponding()) { 194811051Sandreas.hansson@arm.com // cache-to-cache response from some upper cache: 194911051Sandreas.hansson@arm.com // forward response to original requester 195011051Sandreas.hansson@arm.com assert(pkt->isResponse()); 195111051Sandreas.hansson@arm.com } 195211051Sandreas.hansson@arm.com } 195311051Sandreas.hansson@arm.com } 195411051Sandreas.hansson@arm.com 195511051Sandreas.hansson@arm.com if (!blk || !blk->isValid()) { 195611493Sandreas.hansson@arm.com if (is_deferred) { 195711493Sandreas.hansson@arm.com // we no longer have the block, and will not respond, but a 195811493Sandreas.hansson@arm.com // packet was allocated in MSHR::handleSnoop and we have 195911493Sandreas.hansson@arm.com // to delete it 196011493Sandreas.hansson@arm.com assert(pkt->needsResponse()); 196111493Sandreas.hansson@arm.com 196211493Sandreas.hansson@arm.com // we have passed the block to a cache upstream, that 196311493Sandreas.hansson@arm.com // cache should be responding 196411493Sandreas.hansson@arm.com assert(pkt->cacheResponding()); 196511493Sandreas.hansson@arm.com 196611493Sandreas.hansson@arm.com delete pkt; 196711493Sandreas.hansson@arm.com } 196811493Sandreas.hansson@arm.com 196911288Ssteve.reinhardt@amd.com DPRINTF(CacheVerbose, "%s snoop miss for %s addr %#llx size %d\n", 197011051Sandreas.hansson@arm.com __func__, pkt->cmdString(), pkt->getAddr(), pkt->getSize()); 197111127Sandreas.hansson@arm.com return snoop_delay; 197211051Sandreas.hansson@arm.com } else { 197311288Ssteve.reinhardt@amd.com DPRINTF(Cache, "%s snoop hit for %s addr %#llx size %d, " 197411288Ssteve.reinhardt@amd.com "old state is %s\n", __func__, pkt->cmdString(), 197511288Ssteve.reinhardt@amd.com pkt->getAddr(), pkt->getSize(), blk->print()); 197611051Sandreas.hansson@arm.com } 197711051Sandreas.hansson@arm.com 197811051Sandreas.hansson@arm.com chatty_assert(!(isReadOnly && blk->isDirty()), 197911051Sandreas.hansson@arm.com "Should never have a dirty block in a read-only cache %s\n", 198011051Sandreas.hansson@arm.com name()); 198111051Sandreas.hansson@arm.com 198211051Sandreas.hansson@arm.com // We may end up modifying both the block state and the packet (if 198311051Sandreas.hansson@arm.com // we respond in atomic mode), so just figure out what to do now 198411051Sandreas.hansson@arm.com // and then do it later. If we find dirty data while snooping for 198511051Sandreas.hansson@arm.com // an invalidate, we don't need to send a response. The 198611051Sandreas.hansson@arm.com // invalidation itself is taken care of below. 198711051Sandreas.hansson@arm.com bool respond = blk->isDirty() && pkt->needsResponse() && 198811051Sandreas.hansson@arm.com pkt->cmd != MemCmd::InvalidateReq; 198911284Sandreas.hansson@arm.com bool have_writable = blk->isWritable(); 199011051Sandreas.hansson@arm.com 199111051Sandreas.hansson@arm.com // Invalidate any prefetch's from below that would strip write permissions 199211051Sandreas.hansson@arm.com // MemCmd::HardPFReq is only observed by upstream caches. After missing 199311051Sandreas.hansson@arm.com // above and in it's own cache, a new MemCmd::ReadReq is created that 199411051Sandreas.hansson@arm.com // downstream caches observe. 199511051Sandreas.hansson@arm.com if (pkt->mustCheckAbove()) { 199611483Snikos.nikoleris@arm.com DPRINTF(Cache, "Found addr %#llx in upper level cache for snoop %s " 199711483Snikos.nikoleris@arm.com "from lower cache\n", pkt->getAddr(), pkt->cmdString()); 199811051Sandreas.hansson@arm.com pkt->setBlockCached(); 199911127Sandreas.hansson@arm.com return snoop_delay; 200011051Sandreas.hansson@arm.com } 200111051Sandreas.hansson@arm.com 200211285Sandreas.hansson@arm.com if (pkt->isRead() && !invalidate) { 200311285Sandreas.hansson@arm.com // reading without requiring the line in a writable state 200411284Sandreas.hansson@arm.com assert(!needs_writable); 200511284Sandreas.hansson@arm.com pkt->setHasSharers(); 200611285Sandreas.hansson@arm.com 200711285Sandreas.hansson@arm.com // if the requesting packet is uncacheable, retain the line in 200811285Sandreas.hansson@arm.com // the current state, otherwhise unset the writable flag, 200911285Sandreas.hansson@arm.com // which means we go from Modified to Owned (and will respond 201011285Sandreas.hansson@arm.com // below), remain in Owned (and will respond below), from 201111285Sandreas.hansson@arm.com // Exclusive to Shared, or remain in Shared 201211285Sandreas.hansson@arm.com if (!pkt->req->isUncacheable()) 201311285Sandreas.hansson@arm.com blk->status &= ~BlkWritable; 201411051Sandreas.hansson@arm.com } 201511051Sandreas.hansson@arm.com 201611051Sandreas.hansson@arm.com if (respond) { 201711051Sandreas.hansson@arm.com // prevent anyone else from responding, cache as well as 201811051Sandreas.hansson@arm.com // memory, and also prevent any memory from even seeing the 201911284Sandreas.hansson@arm.com // request 202011284Sandreas.hansson@arm.com pkt->setCacheResponding(); 202111284Sandreas.hansson@arm.com if (have_writable) { 202211284Sandreas.hansson@arm.com // inform the cache hierarchy that this cache had the line 202311284Sandreas.hansson@arm.com // in the Modified state so that we avoid unnecessary 202411284Sandreas.hansson@arm.com // invalidations (see Packet::setResponderHadWritable) 202511284Sandreas.hansson@arm.com pkt->setResponderHadWritable(); 202611284Sandreas.hansson@arm.com 202711081Sandreas.hansson@arm.com // in the case of an uncacheable request there is no point 202811284Sandreas.hansson@arm.com // in setting the responderHadWritable flag, but since the 202911284Sandreas.hansson@arm.com // recipient does not care there is no harm in doing so 203011284Sandreas.hansson@arm.com } else { 203111284Sandreas.hansson@arm.com // if the packet has needsWritable set we invalidate our 203211284Sandreas.hansson@arm.com // copy below and all other copies will be invalidates 203311284Sandreas.hansson@arm.com // through express snoops, and if needsWritable is not set 203411284Sandreas.hansson@arm.com // we already called setHasSharers above 203511051Sandreas.hansson@arm.com } 203611284Sandreas.hansson@arm.com 203711285Sandreas.hansson@arm.com // if we are returning a writable and dirty (Modified) line, 203811285Sandreas.hansson@arm.com // we should be invalidating the line 203911285Sandreas.hansson@arm.com panic_if(!invalidate && !pkt->hasSharers(), 204011285Sandreas.hansson@arm.com "%s is passing a Modified line through %s to %#llx, " 204111285Sandreas.hansson@arm.com "but keeping the block", 204211285Sandreas.hansson@arm.com name(), pkt->cmdString(), pkt->getAddr()); 204311285Sandreas.hansson@arm.com 204411051Sandreas.hansson@arm.com if (is_timing) { 204511051Sandreas.hansson@arm.com doTimingSupplyResponse(pkt, blk->data, is_deferred, pending_inval); 204611051Sandreas.hansson@arm.com } else { 204711051Sandreas.hansson@arm.com pkt->makeAtomicResponse(); 204811286Sandreas.hansson@arm.com // packets such as upgrades do not actually have any data 204911286Sandreas.hansson@arm.com // payload 205011286Sandreas.hansson@arm.com if (pkt->hasData()) 205111286Sandreas.hansson@arm.com pkt->setDataFromBlock(blk->data, blkSize); 205211051Sandreas.hansson@arm.com } 205311051Sandreas.hansson@arm.com } 205411051Sandreas.hansson@arm.com 205511051Sandreas.hansson@arm.com if (!respond && is_timing && is_deferred) { 205611271Sandreas.hansson@arm.com // if it's a deferred timing snoop to which we are not 205711271Sandreas.hansson@arm.com // responding, then we've made a copy of both the request and 205811271Sandreas.hansson@arm.com // the packet, delete them here 205911051Sandreas.hansson@arm.com assert(pkt->needsResponse()); 206011493Sandreas.hansson@arm.com assert(!pkt->cacheResponding()); 206111051Sandreas.hansson@arm.com delete pkt->req; 206211051Sandreas.hansson@arm.com delete pkt; 206311051Sandreas.hansson@arm.com } 206411051Sandreas.hansson@arm.com 206511051Sandreas.hansson@arm.com // Do this last in case it deallocates block data or something 206611051Sandreas.hansson@arm.com // like that 206711051Sandreas.hansson@arm.com if (invalidate) { 206811197Sandreas.hansson@arm.com invalidateBlock(blk); 206911051Sandreas.hansson@arm.com } 207011051Sandreas.hansson@arm.com 207111051Sandreas.hansson@arm.com DPRINTF(Cache, "new state is %s\n", blk->print()); 207211127Sandreas.hansson@arm.com 207311127Sandreas.hansson@arm.com return snoop_delay; 207411051Sandreas.hansson@arm.com} 207511051Sandreas.hansson@arm.com 207611051Sandreas.hansson@arm.com 207711051Sandreas.hansson@arm.comvoid 207811051Sandreas.hansson@arm.comCache::recvTimingSnoopReq(PacketPtr pkt) 207911051Sandreas.hansson@arm.com{ 208011288Ssteve.reinhardt@amd.com DPRINTF(CacheVerbose, "%s for %s addr %#llx size %d\n", __func__, 208111051Sandreas.hansson@arm.com pkt->cmdString(), pkt->getAddr(), pkt->getSize()); 208211051Sandreas.hansson@arm.com 208311051Sandreas.hansson@arm.com // Snoops shouldn't happen when bypassing caches 208411051Sandreas.hansson@arm.com assert(!system->bypassCaches()); 208511051Sandreas.hansson@arm.com 208611130Sali.jafri@arm.com // no need to snoop requests that are not in range 208711051Sandreas.hansson@arm.com if (!inRange(pkt->getAddr())) { 208811051Sandreas.hansson@arm.com return; 208911051Sandreas.hansson@arm.com } 209011051Sandreas.hansson@arm.com 209111051Sandreas.hansson@arm.com bool is_secure = pkt->isSecure(); 209211051Sandreas.hansson@arm.com CacheBlk *blk = tags->findBlock(pkt->getAddr(), is_secure); 209311051Sandreas.hansson@arm.com 209411051Sandreas.hansson@arm.com Addr blk_addr = blockAlign(pkt->getAddr()); 209511051Sandreas.hansson@arm.com MSHR *mshr = mshrQueue.findMatch(blk_addr, is_secure); 209611051Sandreas.hansson@arm.com 209711127Sandreas.hansson@arm.com // Update the latency cost of the snoop so that the crossbar can 209811127Sandreas.hansson@arm.com // account for it. Do not overwrite what other neighbouring caches 209911127Sandreas.hansson@arm.com // have already done, rather take the maximum. The update is 210011127Sandreas.hansson@arm.com // tentative, for cases where we return before an upward snoop 210111127Sandreas.hansson@arm.com // happens below. 210211127Sandreas.hansson@arm.com pkt->snoopDelay = std::max<uint32_t>(pkt->snoopDelay, 210311127Sandreas.hansson@arm.com lookupLatency * clockPeriod()); 210411127Sandreas.hansson@arm.com 210511051Sandreas.hansson@arm.com // Inform request(Prefetch, CleanEvict or Writeback) from below of 210611051Sandreas.hansson@arm.com // MSHR hit, set setBlockCached. 210711051Sandreas.hansson@arm.com if (mshr && pkt->mustCheckAbove()) { 210811051Sandreas.hansson@arm.com DPRINTF(Cache, "Setting block cached for %s from" 210911051Sandreas.hansson@arm.com "lower cache on mshr hit %#x\n", 211011051Sandreas.hansson@arm.com pkt->cmdString(), pkt->getAddr()); 211111051Sandreas.hansson@arm.com pkt->setBlockCached(); 211211051Sandreas.hansson@arm.com return; 211311051Sandreas.hansson@arm.com } 211411051Sandreas.hansson@arm.com 211511051Sandreas.hansson@arm.com // Let the MSHR itself track the snoop and decide whether we want 211611051Sandreas.hansson@arm.com // to go ahead and do the regular cache snoop 211711051Sandreas.hansson@arm.com if (mshr && mshr->handleSnoop(pkt, order++)) { 211811051Sandreas.hansson@arm.com DPRINTF(Cache, "Deferring snoop on in-service MSHR to blk %#llx (%s)." 211911051Sandreas.hansson@arm.com "mshrs: %s\n", blk_addr, is_secure ? "s" : "ns", 212011051Sandreas.hansson@arm.com mshr->print()); 212111051Sandreas.hansson@arm.com 212211051Sandreas.hansson@arm.com if (mshr->getNumTargets() > numTarget) 212311051Sandreas.hansson@arm.com warn("allocating bonus target for snoop"); //handle later 212411051Sandreas.hansson@arm.com return; 212511051Sandreas.hansson@arm.com } 212611051Sandreas.hansson@arm.com 212711051Sandreas.hansson@arm.com //We also need to check the writeback buffers and handle those 212811375Sandreas.hansson@arm.com WriteQueueEntry *wb_entry = writeBuffer.findMatch(blk_addr, is_secure); 212911375Sandreas.hansson@arm.com if (wb_entry) { 213011051Sandreas.hansson@arm.com DPRINTF(Cache, "Snoop hit in writeback to addr %#llx (%s)\n", 213111051Sandreas.hansson@arm.com pkt->getAddr(), is_secure ? "s" : "ns"); 213211051Sandreas.hansson@arm.com // Expect to see only Writebacks and/or CleanEvicts here, both of 213311051Sandreas.hansson@arm.com // which should not be generated for uncacheable data. 213411051Sandreas.hansson@arm.com assert(!wb_entry->isUncacheable()); 213511051Sandreas.hansson@arm.com // There should only be a single request responsible for generating 213611051Sandreas.hansson@arm.com // Writebacks/CleanEvicts. 213711051Sandreas.hansson@arm.com assert(wb_entry->getNumTargets() == 1); 213811051Sandreas.hansson@arm.com PacketPtr wb_pkt = wb_entry->getTarget()->pkt; 213911199Sandreas.hansson@arm.com assert(wb_pkt->isEviction()); 214011051Sandreas.hansson@arm.com 214111199Sandreas.hansson@arm.com if (pkt->isEviction()) { 214211051Sandreas.hansson@arm.com // if the block is found in the write queue, set the BLOCK_CACHED 214311051Sandreas.hansson@arm.com // flag for Writeback/CleanEvict snoop. On return the snoop will 214411051Sandreas.hansson@arm.com // propagate the BLOCK_CACHED flag in Writeback packets and prevent 214511051Sandreas.hansson@arm.com // any CleanEvicts from travelling down the memory hierarchy. 214611051Sandreas.hansson@arm.com pkt->setBlockCached(); 214711051Sandreas.hansson@arm.com DPRINTF(Cache, "Squashing %s from lower cache on writequeue hit" 214811051Sandreas.hansson@arm.com " %#x\n", pkt->cmdString(), pkt->getAddr()); 214911051Sandreas.hansson@arm.com return; 215011051Sandreas.hansson@arm.com } 215111051Sandreas.hansson@arm.com 215211332Sandreas.hansson@arm.com // conceptually writebacks are no different to other blocks in 215311332Sandreas.hansson@arm.com // this cache, so the behaviour is modelled after handleSnoop, 215411332Sandreas.hansson@arm.com // the difference being that instead of querying the block 215511332Sandreas.hansson@arm.com // state to determine if it is dirty and writable, we use the 215611332Sandreas.hansson@arm.com // command and fields of the writeback packet 215711332Sandreas.hansson@arm.com bool respond = wb_pkt->cmd == MemCmd::WritebackDirty && 215811332Sandreas.hansson@arm.com pkt->needsResponse() && pkt->cmd != MemCmd::InvalidateReq; 215911332Sandreas.hansson@arm.com bool have_writable = !wb_pkt->hasSharers(); 216011332Sandreas.hansson@arm.com bool invalidate = pkt->isInvalidate(); 216111332Sandreas.hansson@arm.com 216211332Sandreas.hansson@arm.com if (!pkt->req->isUncacheable() && pkt->isRead() && !invalidate) { 216311332Sandreas.hansson@arm.com assert(!pkt->needsWritable()); 216411332Sandreas.hansson@arm.com pkt->setHasSharers(); 216511332Sandreas.hansson@arm.com wb_pkt->setHasSharers(); 216611332Sandreas.hansson@arm.com } 216711332Sandreas.hansson@arm.com 216811332Sandreas.hansson@arm.com if (respond) { 216911284Sandreas.hansson@arm.com pkt->setCacheResponding(); 217011332Sandreas.hansson@arm.com 217111332Sandreas.hansson@arm.com if (have_writable) { 217211332Sandreas.hansson@arm.com pkt->setResponderHadWritable(); 217311051Sandreas.hansson@arm.com } 217411332Sandreas.hansson@arm.com 217511051Sandreas.hansson@arm.com doTimingSupplyResponse(pkt, wb_pkt->getConstPtr<uint8_t>(), 217611051Sandreas.hansson@arm.com false, false); 217711051Sandreas.hansson@arm.com } 217811051Sandreas.hansson@arm.com 217911332Sandreas.hansson@arm.com if (invalidate) { 218011051Sandreas.hansson@arm.com // Invalidation trumps our writeback... discard here 218111051Sandreas.hansson@arm.com // Note: markInService will remove entry from writeback buffer. 218211375Sandreas.hansson@arm.com markInService(wb_entry); 218311051Sandreas.hansson@arm.com delete wb_pkt; 218411051Sandreas.hansson@arm.com } 218511051Sandreas.hansson@arm.com } 218611051Sandreas.hansson@arm.com 218711051Sandreas.hansson@arm.com // If this was a shared writeback, there may still be 218811051Sandreas.hansson@arm.com // other shared copies above that require invalidation. 218911051Sandreas.hansson@arm.com // We could be more selective and return here if the 219011051Sandreas.hansson@arm.com // request is non-exclusive or if the writeback is 219111051Sandreas.hansson@arm.com // exclusive. 219211127Sandreas.hansson@arm.com uint32_t snoop_delay = handleSnoop(pkt, blk, true, false, false); 219311127Sandreas.hansson@arm.com 219411127Sandreas.hansson@arm.com // Override what we did when we first saw the snoop, as we now 219511127Sandreas.hansson@arm.com // also have the cost of the upwards snoops to account for 219611127Sandreas.hansson@arm.com pkt->snoopDelay = std::max<uint32_t>(pkt->snoopDelay, snoop_delay + 219711127Sandreas.hansson@arm.com lookupLatency * clockPeriod()); 219811051Sandreas.hansson@arm.com} 219911051Sandreas.hansson@arm.com 220011051Sandreas.hansson@arm.combool 220111051Sandreas.hansson@arm.comCache::CpuSidePort::recvTimingSnoopResp(PacketPtr pkt) 220211051Sandreas.hansson@arm.com{ 220311051Sandreas.hansson@arm.com // Express snoop responses from master to slave, e.g., from L1 to L2 220411051Sandreas.hansson@arm.com cache->recvTimingSnoopResp(pkt); 220511051Sandreas.hansson@arm.com return true; 220611051Sandreas.hansson@arm.com} 220711051Sandreas.hansson@arm.com 220811051Sandreas.hansson@arm.comTick 220911051Sandreas.hansson@arm.comCache::recvAtomicSnoop(PacketPtr pkt) 221011051Sandreas.hansson@arm.com{ 221111051Sandreas.hansson@arm.com // Snoops shouldn't happen when bypassing caches 221211051Sandreas.hansson@arm.com assert(!system->bypassCaches()); 221311051Sandreas.hansson@arm.com 221411130Sali.jafri@arm.com // no need to snoop requests that are not in range. 221511130Sali.jafri@arm.com if (!inRange(pkt->getAddr())) { 221611051Sandreas.hansson@arm.com return 0; 221711051Sandreas.hansson@arm.com } 221811051Sandreas.hansson@arm.com 221911051Sandreas.hansson@arm.com CacheBlk *blk = tags->findBlock(pkt->getAddr(), pkt->isSecure()); 222011127Sandreas.hansson@arm.com uint32_t snoop_delay = handleSnoop(pkt, blk, false, false, false); 222111127Sandreas.hansson@arm.com return snoop_delay + lookupLatency * clockPeriod(); 222211051Sandreas.hansson@arm.com} 222311051Sandreas.hansson@arm.com 222411051Sandreas.hansson@arm.com 222511375Sandreas.hansson@arm.comQueueEntry* 222611375Sandreas.hansson@arm.comCache::getNextQueueEntry() 222711051Sandreas.hansson@arm.com{ 222811051Sandreas.hansson@arm.com // Check both MSHR queue and write buffer for potential requests, 222911051Sandreas.hansson@arm.com // note that null does not mean there is no request, it could 223011051Sandreas.hansson@arm.com // simply be that it is not ready 223111375Sandreas.hansson@arm.com MSHR *miss_mshr = mshrQueue.getNext(); 223211375Sandreas.hansson@arm.com WriteQueueEntry *wq_entry = writeBuffer.getNext(); 223311051Sandreas.hansson@arm.com 223411051Sandreas.hansson@arm.com // If we got a write buffer request ready, first priority is a 223511453Sandreas.hansson@arm.com // full write buffer, otherwise we favour the miss requests 223611453Sandreas.hansson@arm.com if (wq_entry && (writeBuffer.isFull() || !miss_mshr)) { 223711051Sandreas.hansson@arm.com // need to search MSHR queue for conflicting earlier miss. 223811051Sandreas.hansson@arm.com MSHR *conflict_mshr = 223911375Sandreas.hansson@arm.com mshrQueue.findPending(wq_entry->blkAddr, 224011375Sandreas.hansson@arm.com wq_entry->isSecure); 224111375Sandreas.hansson@arm.com 224211375Sandreas.hansson@arm.com if (conflict_mshr && conflict_mshr->order < wq_entry->order) { 224311051Sandreas.hansson@arm.com // Service misses in order until conflict is cleared. 224411051Sandreas.hansson@arm.com return conflict_mshr; 224511051Sandreas.hansson@arm.com 224611051Sandreas.hansson@arm.com // @todo Note that we ignore the ready time of the conflict here 224711051Sandreas.hansson@arm.com } 224811051Sandreas.hansson@arm.com 224911051Sandreas.hansson@arm.com // No conflicts; issue write 225011375Sandreas.hansson@arm.com return wq_entry; 225111051Sandreas.hansson@arm.com } else if (miss_mshr) { 225211051Sandreas.hansson@arm.com // need to check for conflicting earlier writeback 225311375Sandreas.hansson@arm.com WriteQueueEntry *conflict_mshr = 225411051Sandreas.hansson@arm.com writeBuffer.findPending(miss_mshr->blkAddr, 225511051Sandreas.hansson@arm.com miss_mshr->isSecure); 225611051Sandreas.hansson@arm.com if (conflict_mshr) { 225711051Sandreas.hansson@arm.com // not sure why we don't check order here... it was in the 225811051Sandreas.hansson@arm.com // original code but commented out. 225911051Sandreas.hansson@arm.com 226011051Sandreas.hansson@arm.com // The only way this happens is if we are 226111051Sandreas.hansson@arm.com // doing a write and we didn't have permissions 226211051Sandreas.hansson@arm.com // then subsequently saw a writeback (owned got evicted) 226311051Sandreas.hansson@arm.com // We need to make sure to perform the writeback first 226411051Sandreas.hansson@arm.com // To preserve the dirty data, then we can issue the write 226511051Sandreas.hansson@arm.com 226611375Sandreas.hansson@arm.com // should we return wq_entry here instead? I.e. do we 226711051Sandreas.hansson@arm.com // have to flush writes in order? I don't think so... not 226811051Sandreas.hansson@arm.com // for Alpha anyway. Maybe for x86? 226911051Sandreas.hansson@arm.com return conflict_mshr; 227011051Sandreas.hansson@arm.com 227111051Sandreas.hansson@arm.com // @todo Note that we ignore the ready time of the conflict here 227211051Sandreas.hansson@arm.com } 227311051Sandreas.hansson@arm.com 227411051Sandreas.hansson@arm.com // No conflicts; issue read 227511051Sandreas.hansson@arm.com return miss_mshr; 227611051Sandreas.hansson@arm.com } 227711051Sandreas.hansson@arm.com 227811051Sandreas.hansson@arm.com // fall through... no pending requests. Try a prefetch. 227911375Sandreas.hansson@arm.com assert(!miss_mshr && !wq_entry); 228011051Sandreas.hansson@arm.com if (prefetcher && mshrQueue.canPrefetch()) { 228111051Sandreas.hansson@arm.com // If we have a miss queue slot, we can try a prefetch 228211051Sandreas.hansson@arm.com PacketPtr pkt = prefetcher->getPacket(); 228311051Sandreas.hansson@arm.com if (pkt) { 228411051Sandreas.hansson@arm.com Addr pf_addr = blockAlign(pkt->getAddr()); 228511051Sandreas.hansson@arm.com if (!tags->findBlock(pf_addr, pkt->isSecure()) && 228611051Sandreas.hansson@arm.com !mshrQueue.findMatch(pf_addr, pkt->isSecure()) && 228711051Sandreas.hansson@arm.com !writeBuffer.findMatch(pf_addr, pkt->isSecure())) { 228811051Sandreas.hansson@arm.com // Update statistic on number of prefetches issued 228911051Sandreas.hansson@arm.com // (hwpf_mshr_misses) 229011051Sandreas.hansson@arm.com assert(pkt->req->masterId() < system->maxMasters()); 229111051Sandreas.hansson@arm.com mshr_misses[pkt->cmdToIndex()][pkt->req->masterId()]++; 229211051Sandreas.hansson@arm.com 229311051Sandreas.hansson@arm.com // allocate an MSHR and return it, note 229411051Sandreas.hansson@arm.com // that we send the packet straight away, so do not 229511051Sandreas.hansson@arm.com // schedule the send 229611051Sandreas.hansson@arm.com return allocateMissBuffer(pkt, curTick(), false); 229711051Sandreas.hansson@arm.com } else { 229811051Sandreas.hansson@arm.com // free the request and packet 229911051Sandreas.hansson@arm.com delete pkt->req; 230011051Sandreas.hansson@arm.com delete pkt; 230111051Sandreas.hansson@arm.com } 230211051Sandreas.hansson@arm.com } 230311051Sandreas.hansson@arm.com } 230411051Sandreas.hansson@arm.com 230511375Sandreas.hansson@arm.com return nullptr; 230611051Sandreas.hansson@arm.com} 230711051Sandreas.hansson@arm.com 230811051Sandreas.hansson@arm.combool 230911130Sali.jafri@arm.comCache::isCachedAbove(PacketPtr pkt, bool is_timing) const 231011051Sandreas.hansson@arm.com{ 231111051Sandreas.hansson@arm.com if (!forwardSnoops) 231211051Sandreas.hansson@arm.com return false; 231311051Sandreas.hansson@arm.com // Mirroring the flow of HardPFReqs, the cache sends CleanEvict and 231411051Sandreas.hansson@arm.com // Writeback snoops into upper level caches to check for copies of the 231511051Sandreas.hansson@arm.com // same block. Using the BLOCK_CACHED flag with the Writeback/CleanEvict 231611051Sandreas.hansson@arm.com // packet, the cache can inform the crossbar below of presence or absence 231711051Sandreas.hansson@arm.com // of the block. 231811130Sali.jafri@arm.com if (is_timing) { 231911130Sali.jafri@arm.com Packet snoop_pkt(pkt, true, false); 232011130Sali.jafri@arm.com snoop_pkt.setExpressSnoop(); 232111130Sali.jafri@arm.com // Assert that packet is either Writeback or CleanEvict and not a 232211130Sali.jafri@arm.com // prefetch request because prefetch requests need an MSHR and may 232311130Sali.jafri@arm.com // generate a snoop response. 232411199Sandreas.hansson@arm.com assert(pkt->isEviction()); 232511484Snikos.nikoleris@arm.com snoop_pkt.senderState = nullptr; 232611130Sali.jafri@arm.com cpuSidePort->sendTimingSnoopReq(&snoop_pkt); 232711130Sali.jafri@arm.com // Writeback/CleanEvict snoops do not generate a snoop response. 232811284Sandreas.hansson@arm.com assert(!(snoop_pkt.cacheResponding())); 232911130Sali.jafri@arm.com return snoop_pkt.isBlockCached(); 233011130Sali.jafri@arm.com } else { 233111130Sali.jafri@arm.com cpuSidePort->sendAtomicSnoop(pkt); 233211130Sali.jafri@arm.com return pkt->isBlockCached(); 233311130Sali.jafri@arm.com } 233411051Sandreas.hansson@arm.com} 233511051Sandreas.hansson@arm.com 233611375Sandreas.hansson@arm.comTick 233711375Sandreas.hansson@arm.comCache::nextQueueReadyTime() const 233811051Sandreas.hansson@arm.com{ 233911375Sandreas.hansson@arm.com Tick nextReady = std::min(mshrQueue.nextReadyTime(), 234011375Sandreas.hansson@arm.com writeBuffer.nextReadyTime()); 234111375Sandreas.hansson@arm.com 234211375Sandreas.hansson@arm.com // Don't signal prefetch ready time if no MSHRs available 234311375Sandreas.hansson@arm.com // Will signal once enoguh MSHRs are deallocated 234411375Sandreas.hansson@arm.com if (prefetcher && mshrQueue.canPrefetch()) { 234511375Sandreas.hansson@arm.com nextReady = std::min(nextReady, 234611375Sandreas.hansson@arm.com prefetcher->nextPrefetchReadyTime()); 234711051Sandreas.hansson@arm.com } 234811051Sandreas.hansson@arm.com 234911375Sandreas.hansson@arm.com return nextReady; 235011375Sandreas.hansson@arm.com} 235111375Sandreas.hansson@arm.com 235211375Sandreas.hansson@arm.combool 235311375Sandreas.hansson@arm.comCache::sendMSHRQueuePacket(MSHR* mshr) 235411375Sandreas.hansson@arm.com{ 235511375Sandreas.hansson@arm.com assert(mshr); 235611375Sandreas.hansson@arm.com 235711051Sandreas.hansson@arm.com // use request from 1st target 235811051Sandreas.hansson@arm.com PacketPtr tgt_pkt = mshr->getTarget()->pkt; 235911375Sandreas.hansson@arm.com 236011375Sandreas.hansson@arm.com DPRINTF(Cache, "%s MSHR %s for addr %#llx size %d\n", __func__, 236111375Sandreas.hansson@arm.com tgt_pkt->cmdString(), tgt_pkt->getAddr(), 236211375Sandreas.hansson@arm.com tgt_pkt->getSize()); 236311051Sandreas.hansson@arm.com 236411051Sandreas.hansson@arm.com CacheBlk *blk = tags->findBlock(mshr->blkAddr, mshr->isSecure); 236511051Sandreas.hansson@arm.com 236611051Sandreas.hansson@arm.com if (tgt_pkt->cmd == MemCmd::HardPFReq && forwardSnoops) { 236711375Sandreas.hansson@arm.com // we should never have hardware prefetches to allocated 236811375Sandreas.hansson@arm.com // blocks 236911484Snikos.nikoleris@arm.com assert(blk == nullptr); 237011375Sandreas.hansson@arm.com 237111051Sandreas.hansson@arm.com // We need to check the caches above us to verify that 237211051Sandreas.hansson@arm.com // they don't have a copy of this block in the dirty state 237311051Sandreas.hansson@arm.com // at the moment. Without this check we could get a stale 237411051Sandreas.hansson@arm.com // copy from memory that might get used in place of the 237511051Sandreas.hansson@arm.com // dirty one. 237611051Sandreas.hansson@arm.com Packet snoop_pkt(tgt_pkt, true, false); 237711051Sandreas.hansson@arm.com snoop_pkt.setExpressSnoop(); 237811275Sandreas.hansson@arm.com // We are sending this packet upwards, but if it hits we will 237911275Sandreas.hansson@arm.com // get a snoop response that we end up treating just like a 238011275Sandreas.hansson@arm.com // normal response, hence it needs the MSHR as its sender 238111275Sandreas.hansson@arm.com // state 238211051Sandreas.hansson@arm.com snoop_pkt.senderState = mshr; 238311051Sandreas.hansson@arm.com cpuSidePort->sendTimingSnoopReq(&snoop_pkt); 238411051Sandreas.hansson@arm.com 238511051Sandreas.hansson@arm.com // Check to see if the prefetch was squashed by an upper cache (to 238611051Sandreas.hansson@arm.com // prevent us from grabbing the line) or if a Check to see if a 238711051Sandreas.hansson@arm.com // writeback arrived between the time the prefetch was placed in 238811051Sandreas.hansson@arm.com // the MSHRs and when it was selected to be sent or if the 238911051Sandreas.hansson@arm.com // prefetch was squashed by an upper cache. 239011051Sandreas.hansson@arm.com 239111284Sandreas.hansson@arm.com // It is important to check cacheResponding before 239211284Sandreas.hansson@arm.com // prefetchSquashed. If another cache has committed to 239311284Sandreas.hansson@arm.com // responding, it will be sending a dirty response which will 239411284Sandreas.hansson@arm.com // arrive at the MSHR allocated for this request. Checking the 239511284Sandreas.hansson@arm.com // prefetchSquash first may result in the MSHR being 239611284Sandreas.hansson@arm.com // prematurely deallocated. 239711284Sandreas.hansson@arm.com if (snoop_pkt.cacheResponding()) { 239811276Sandreas.hansson@arm.com auto M5_VAR_USED r = outstandingSnoop.insert(snoop_pkt.req); 239911276Sandreas.hansson@arm.com assert(r.second); 240011284Sandreas.hansson@arm.com 240111284Sandreas.hansson@arm.com // if we are getting a snoop response with no sharers it 240211284Sandreas.hansson@arm.com // will be allocated as Modified 240311284Sandreas.hansson@arm.com bool pending_modified_resp = !snoop_pkt.hasSharers(); 240411284Sandreas.hansson@arm.com markInService(mshr, pending_modified_resp); 240511284Sandreas.hansson@arm.com 240611051Sandreas.hansson@arm.com DPRINTF(Cache, "Upward snoop of prefetch for addr" 240711051Sandreas.hansson@arm.com " %#x (%s) hit\n", 240811051Sandreas.hansson@arm.com tgt_pkt->getAddr(), tgt_pkt->isSecure()? "s": "ns"); 240911375Sandreas.hansson@arm.com return false; 241011051Sandreas.hansson@arm.com } 241111051Sandreas.hansson@arm.com 241211375Sandreas.hansson@arm.com if (snoop_pkt.isBlockCached()) { 241311051Sandreas.hansson@arm.com DPRINTF(Cache, "Block present, prefetch squashed by cache. " 241411051Sandreas.hansson@arm.com "Deallocating mshr target %#x.\n", 241511051Sandreas.hansson@arm.com mshr->blkAddr); 241611375Sandreas.hansson@arm.com 241711051Sandreas.hansson@arm.com // Deallocate the mshr target 241811375Sandreas.hansson@arm.com if (mshrQueue.forceDeallocateTarget(mshr)) { 241911277Sandreas.hansson@arm.com // Clear block if this deallocation resulted freed an 242011277Sandreas.hansson@arm.com // mshr when all had previously been utilized 242111375Sandreas.hansson@arm.com clearBlocked(Blocked_NoMSHRs); 242211051Sandreas.hansson@arm.com } 242311375Sandreas.hansson@arm.com return false; 242411051Sandreas.hansson@arm.com } 242511051Sandreas.hansson@arm.com } 242611051Sandreas.hansson@arm.com 242711375Sandreas.hansson@arm.com // either a prefetch that is not present upstream, or a normal 242811375Sandreas.hansson@arm.com // MSHR request, proceed to get the packet to send downstream 242911452Sandreas.hansson@arm.com PacketPtr pkt = createMissPacket(tgt_pkt, blk, mshr->needsWritable()); 243011375Sandreas.hansson@arm.com 243111484Snikos.nikoleris@arm.com mshr->isForward = (pkt == nullptr); 243211375Sandreas.hansson@arm.com 243311375Sandreas.hansson@arm.com if (mshr->isForward) { 243411375Sandreas.hansson@arm.com // not a cache block request, but a response is expected 243511375Sandreas.hansson@arm.com // make copy of current packet to forward, keep current 243611375Sandreas.hansson@arm.com // copy for response handling 243711375Sandreas.hansson@arm.com pkt = new Packet(tgt_pkt, false, true); 243811375Sandreas.hansson@arm.com assert(!pkt->isWrite()); 243911375Sandreas.hansson@arm.com } 244011375Sandreas.hansson@arm.com 244111375Sandreas.hansson@arm.com // play it safe and append (rather than set) the sender state, 244211375Sandreas.hansson@arm.com // as forwarded packets may already have existing state 244311375Sandreas.hansson@arm.com pkt->pushSenderState(mshr); 244411375Sandreas.hansson@arm.com 244511375Sandreas.hansson@arm.com if (!memSidePort->sendTimingReq(pkt)) { 244611375Sandreas.hansson@arm.com // we are awaiting a retry, but we 244711375Sandreas.hansson@arm.com // delete the packet and will be creating a new packet 244811375Sandreas.hansson@arm.com // when we get the opportunity 244911375Sandreas.hansson@arm.com delete pkt; 245011375Sandreas.hansson@arm.com 245111375Sandreas.hansson@arm.com // note that we have now masked any requestBus and 245211375Sandreas.hansson@arm.com // schedSendEvent (we will wait for a retry before 245311375Sandreas.hansson@arm.com // doing anything), and this is so even if we do not 245411375Sandreas.hansson@arm.com // care about this packet and might override it before 245511375Sandreas.hansson@arm.com // it gets retried 245611375Sandreas.hansson@arm.com return true; 245711375Sandreas.hansson@arm.com } else { 245811375Sandreas.hansson@arm.com // As part of the call to sendTimingReq the packet is 245911375Sandreas.hansson@arm.com // forwarded to all neighbouring caches (and any caches 246011375Sandreas.hansson@arm.com // above them) as a snoop. Thus at this point we know if 246111375Sandreas.hansson@arm.com // any of the neighbouring caches are responding, and if 246211375Sandreas.hansson@arm.com // so, we know it is dirty, and we can determine if it is 246311375Sandreas.hansson@arm.com // being passed as Modified, making our MSHR the ordering 246411375Sandreas.hansson@arm.com // point 246511375Sandreas.hansson@arm.com bool pending_modified_resp = !pkt->hasSharers() && 246611375Sandreas.hansson@arm.com pkt->cacheResponding(); 246711375Sandreas.hansson@arm.com markInService(mshr, pending_modified_resp); 246811375Sandreas.hansson@arm.com return false; 246911375Sandreas.hansson@arm.com } 247011375Sandreas.hansson@arm.com} 247111375Sandreas.hansson@arm.com 247211375Sandreas.hansson@arm.combool 247311375Sandreas.hansson@arm.comCache::sendWriteQueuePacket(WriteQueueEntry* wq_entry) 247411375Sandreas.hansson@arm.com{ 247511375Sandreas.hansson@arm.com assert(wq_entry); 247611375Sandreas.hansson@arm.com 247711375Sandreas.hansson@arm.com // always a single target for write queue entries 247811375Sandreas.hansson@arm.com PacketPtr tgt_pkt = wq_entry->getTarget()->pkt; 247911375Sandreas.hansson@arm.com 248011375Sandreas.hansson@arm.com DPRINTF(Cache, "%s write %s for addr %#llx size %d\n", __func__, 248111375Sandreas.hansson@arm.com tgt_pkt->cmdString(), tgt_pkt->getAddr(), 248211375Sandreas.hansson@arm.com tgt_pkt->getSize()); 248311375Sandreas.hansson@arm.com 248411453Sandreas.hansson@arm.com // forward as is, both for evictions and uncacheable writes 248511453Sandreas.hansson@arm.com if (!memSidePort->sendTimingReq(tgt_pkt)) { 248611375Sandreas.hansson@arm.com // note that we have now masked any requestBus and 248711375Sandreas.hansson@arm.com // schedSendEvent (we will wait for a retry before 248811375Sandreas.hansson@arm.com // doing anything), and this is so even if we do not 248911375Sandreas.hansson@arm.com // care about this packet and might override it before 249011375Sandreas.hansson@arm.com // it gets retried 249111375Sandreas.hansson@arm.com return true; 249211375Sandreas.hansson@arm.com } else { 249311375Sandreas.hansson@arm.com markInService(wq_entry); 249411375Sandreas.hansson@arm.com return false; 249511051Sandreas.hansson@arm.com } 249611051Sandreas.hansson@arm.com} 249711051Sandreas.hansson@arm.com 249811051Sandreas.hansson@arm.comvoid 249911051Sandreas.hansson@arm.comCache::serialize(CheckpointOut &cp) const 250011051Sandreas.hansson@arm.com{ 250111051Sandreas.hansson@arm.com bool dirty(isDirty()); 250211051Sandreas.hansson@arm.com 250311051Sandreas.hansson@arm.com if (dirty) { 250411051Sandreas.hansson@arm.com warn("*** The cache still contains dirty data. ***\n"); 250511051Sandreas.hansson@arm.com warn(" Make sure to drain the system using the correct flags.\n"); 250611483Snikos.nikoleris@arm.com warn(" This checkpoint will not restore correctly and dirty data " 250711483Snikos.nikoleris@arm.com " in the cache will be lost!\n"); 250811051Sandreas.hansson@arm.com } 250911051Sandreas.hansson@arm.com 251011051Sandreas.hansson@arm.com // Since we don't checkpoint the data in the cache, any dirty data 251111051Sandreas.hansson@arm.com // will be lost when restoring from a checkpoint of a system that 251211051Sandreas.hansson@arm.com // wasn't drained properly. Flag the checkpoint as invalid if the 251311051Sandreas.hansson@arm.com // cache contains dirty data. 251411051Sandreas.hansson@arm.com bool bad_checkpoint(dirty); 251511051Sandreas.hansson@arm.com SERIALIZE_SCALAR(bad_checkpoint); 251611051Sandreas.hansson@arm.com} 251711051Sandreas.hansson@arm.com 251811051Sandreas.hansson@arm.comvoid 251911051Sandreas.hansson@arm.comCache::unserialize(CheckpointIn &cp) 252011051Sandreas.hansson@arm.com{ 252111051Sandreas.hansson@arm.com bool bad_checkpoint; 252211051Sandreas.hansson@arm.com UNSERIALIZE_SCALAR(bad_checkpoint); 252311051Sandreas.hansson@arm.com if (bad_checkpoint) { 252411051Sandreas.hansson@arm.com fatal("Restoring from checkpoints with dirty caches is not supported " 252511051Sandreas.hansson@arm.com "in the classic memory system. Please remove any caches or " 252611051Sandreas.hansson@arm.com " drain them properly before taking checkpoints.\n"); 252711051Sandreas.hansson@arm.com } 252811051Sandreas.hansson@arm.com} 252911051Sandreas.hansson@arm.com 253011051Sandreas.hansson@arm.com/////////////// 253111051Sandreas.hansson@arm.com// 253211051Sandreas.hansson@arm.com// CpuSidePort 253311051Sandreas.hansson@arm.com// 253411051Sandreas.hansson@arm.com/////////////// 253511051Sandreas.hansson@arm.com 253611051Sandreas.hansson@arm.comAddrRangeList 253711051Sandreas.hansson@arm.comCache::CpuSidePort::getAddrRanges() const 253811051Sandreas.hansson@arm.com{ 253911051Sandreas.hansson@arm.com return cache->getAddrRanges(); 254011051Sandreas.hansson@arm.com} 254111051Sandreas.hansson@arm.com 254211051Sandreas.hansson@arm.combool 254311051Sandreas.hansson@arm.comCache::CpuSidePort::recvTimingReq(PacketPtr pkt) 254411051Sandreas.hansson@arm.com{ 254511051Sandreas.hansson@arm.com assert(!cache->system->bypassCaches()); 254611051Sandreas.hansson@arm.com 254711051Sandreas.hansson@arm.com bool success = false; 254811051Sandreas.hansson@arm.com 254911334Sandreas.hansson@arm.com // always let express snoop packets through if even if blocked 255011334Sandreas.hansson@arm.com if (pkt->isExpressSnoop()) { 255111051Sandreas.hansson@arm.com // do not change the current retry state 255211051Sandreas.hansson@arm.com bool M5_VAR_USED bypass_success = cache->recvTimingReq(pkt); 255311051Sandreas.hansson@arm.com assert(bypass_success); 255411051Sandreas.hansson@arm.com return true; 255511051Sandreas.hansson@arm.com } else if (blocked || mustSendRetry) { 255611051Sandreas.hansson@arm.com // either already committed to send a retry, or blocked 255711051Sandreas.hansson@arm.com success = false; 255811051Sandreas.hansson@arm.com } else { 255911051Sandreas.hansson@arm.com // pass it on to the cache, and let the cache decide if we 256011051Sandreas.hansson@arm.com // have to retry or not 256111051Sandreas.hansson@arm.com success = cache->recvTimingReq(pkt); 256211051Sandreas.hansson@arm.com } 256311051Sandreas.hansson@arm.com 256411051Sandreas.hansson@arm.com // remember if we have to retry 256511051Sandreas.hansson@arm.com mustSendRetry = !success; 256611051Sandreas.hansson@arm.com return success; 256711051Sandreas.hansson@arm.com} 256811051Sandreas.hansson@arm.com 256911051Sandreas.hansson@arm.comTick 257011051Sandreas.hansson@arm.comCache::CpuSidePort::recvAtomic(PacketPtr pkt) 257111051Sandreas.hansson@arm.com{ 257211051Sandreas.hansson@arm.com return cache->recvAtomic(pkt); 257311051Sandreas.hansson@arm.com} 257411051Sandreas.hansson@arm.com 257511051Sandreas.hansson@arm.comvoid 257611051Sandreas.hansson@arm.comCache::CpuSidePort::recvFunctional(PacketPtr pkt) 257711051Sandreas.hansson@arm.com{ 257811051Sandreas.hansson@arm.com // functional request 257911051Sandreas.hansson@arm.com cache->functionalAccess(pkt, true); 258011051Sandreas.hansson@arm.com} 258111051Sandreas.hansson@arm.com 258211051Sandreas.hansson@arm.comCache:: 258311051Sandreas.hansson@arm.comCpuSidePort::CpuSidePort(const std::string &_name, Cache *_cache, 258411051Sandreas.hansson@arm.com const std::string &_label) 258511051Sandreas.hansson@arm.com : BaseCache::CacheSlavePort(_name, _cache, _label), cache(_cache) 258611051Sandreas.hansson@arm.com{ 258711051Sandreas.hansson@arm.com} 258811051Sandreas.hansson@arm.com 258911053Sandreas.hansson@arm.comCache* 259011053Sandreas.hansson@arm.comCacheParams::create() 259111053Sandreas.hansson@arm.com{ 259211053Sandreas.hansson@arm.com assert(tags); 259311053Sandreas.hansson@arm.com 259411053Sandreas.hansson@arm.com return new Cache(this); 259511053Sandreas.hansson@arm.com} 259611051Sandreas.hansson@arm.com/////////////// 259711051Sandreas.hansson@arm.com// 259811051Sandreas.hansson@arm.com// MemSidePort 259911051Sandreas.hansson@arm.com// 260011051Sandreas.hansson@arm.com/////////////// 260111051Sandreas.hansson@arm.com 260211051Sandreas.hansson@arm.combool 260311051Sandreas.hansson@arm.comCache::MemSidePort::recvTimingResp(PacketPtr pkt) 260411051Sandreas.hansson@arm.com{ 260511051Sandreas.hansson@arm.com cache->recvTimingResp(pkt); 260611051Sandreas.hansson@arm.com return true; 260711051Sandreas.hansson@arm.com} 260811051Sandreas.hansson@arm.com 260911051Sandreas.hansson@arm.com// Express snooping requests to memside port 261011051Sandreas.hansson@arm.comvoid 261111051Sandreas.hansson@arm.comCache::MemSidePort::recvTimingSnoopReq(PacketPtr pkt) 261211051Sandreas.hansson@arm.com{ 261311051Sandreas.hansson@arm.com // handle snooping requests 261411051Sandreas.hansson@arm.com cache->recvTimingSnoopReq(pkt); 261511051Sandreas.hansson@arm.com} 261611051Sandreas.hansson@arm.com 261711051Sandreas.hansson@arm.comTick 261811051Sandreas.hansson@arm.comCache::MemSidePort::recvAtomicSnoop(PacketPtr pkt) 261911051Sandreas.hansson@arm.com{ 262011051Sandreas.hansson@arm.com return cache->recvAtomicSnoop(pkt); 262111051Sandreas.hansson@arm.com} 262211051Sandreas.hansson@arm.com 262311051Sandreas.hansson@arm.comvoid 262411051Sandreas.hansson@arm.comCache::MemSidePort::recvFunctionalSnoop(PacketPtr pkt) 262511051Sandreas.hansson@arm.com{ 262611051Sandreas.hansson@arm.com // functional snoop (note that in contrast to atomic we don't have 262711051Sandreas.hansson@arm.com // a specific functionalSnoop method, as they have the same 262811051Sandreas.hansson@arm.com // behaviour regardless) 262911051Sandreas.hansson@arm.com cache->functionalAccess(pkt, false); 263011051Sandreas.hansson@arm.com} 263111051Sandreas.hansson@arm.com 263211051Sandreas.hansson@arm.comvoid 263311051Sandreas.hansson@arm.comCache::CacheReqPacketQueue::sendDeferredPacket() 263411051Sandreas.hansson@arm.com{ 263511051Sandreas.hansson@arm.com // sanity check 263611051Sandreas.hansson@arm.com assert(!waitingOnRetry); 263711051Sandreas.hansson@arm.com 263811051Sandreas.hansson@arm.com // there should never be any deferred request packets in the 263911051Sandreas.hansson@arm.com // queue, instead we resly on the cache to provide the packets 264011051Sandreas.hansson@arm.com // from the MSHR queue or write queue 264111051Sandreas.hansson@arm.com assert(deferredPacketReadyTime() == MaxTick); 264211051Sandreas.hansson@arm.com 264311051Sandreas.hansson@arm.com // check for request packets (requests & writebacks) 264411375Sandreas.hansson@arm.com QueueEntry* entry = cache.getNextQueueEntry(); 264511375Sandreas.hansson@arm.com 264611375Sandreas.hansson@arm.com if (!entry) { 264711051Sandreas.hansson@arm.com // can happen if e.g. we attempt a writeback and fail, but 264811051Sandreas.hansson@arm.com // before the retry, the writeback is eliminated because 264911051Sandreas.hansson@arm.com // we snoop another cache's ReadEx. 265011051Sandreas.hansson@arm.com } else { 265111051Sandreas.hansson@arm.com // let our snoop responses go first if there are responses to 265211375Sandreas.hansson@arm.com // the same addresses 265311375Sandreas.hansson@arm.com if (checkConflictingSnoop(entry->blkAddr)) { 265411051Sandreas.hansson@arm.com return; 265511051Sandreas.hansson@arm.com } 265611375Sandreas.hansson@arm.com waitingOnRetry = entry->sendPacket(cache); 265711051Sandreas.hansson@arm.com } 265811051Sandreas.hansson@arm.com 265911051Sandreas.hansson@arm.com // if we succeeded and are not waiting for a retry, schedule the 266011375Sandreas.hansson@arm.com // next send considering when the next queue is ready, note that 266111051Sandreas.hansson@arm.com // snoop responses have their own packet queue and thus schedule 266211051Sandreas.hansson@arm.com // their own events 266311051Sandreas.hansson@arm.com if (!waitingOnRetry) { 266411375Sandreas.hansson@arm.com schedSendEvent(cache.nextQueueReadyTime()); 266511051Sandreas.hansson@arm.com } 266611051Sandreas.hansson@arm.com} 266711051Sandreas.hansson@arm.com 266811051Sandreas.hansson@arm.comCache:: 266911051Sandreas.hansson@arm.comMemSidePort::MemSidePort(const std::string &_name, Cache *_cache, 267011051Sandreas.hansson@arm.com const std::string &_label) 267111051Sandreas.hansson@arm.com : BaseCache::CacheMasterPort(_name, _cache, _reqQueue, _snoopRespQueue), 267211051Sandreas.hansson@arm.com _reqQueue(*_cache, *this, _snoopRespQueue, _label), 267311051Sandreas.hansson@arm.com _snoopRespQueue(*_cache, *this, _label), cache(_cache) 267411051Sandreas.hansson@arm.com{ 267511051Sandreas.hansson@arm.com} 2676