diff options
Diffstat (limited to 'src/mem/cache')
| -rw-r--r-- | src/mem/cache/Cache.py | 12 | ||||
| -rw-r--r-- | src/mem/cache/SConscript | 3 | ||||
| -rw-r--r-- | src/mem/cache/mshr.cc | 5 | ||||
| -rw-r--r-- | src/mem/cache/noncoherent_cache.cc | 375 | ||||
| -rw-r--r-- | src/mem/cache/noncoherent_cache.hh | 133 | ||||
| -rw-r--r-- | src/mem/cache/queue.hh | 13 |
6 files changed, 529 insertions, 12 deletions
diff --git a/src/mem/cache/Cache.py b/src/mem/cache/Cache.py index a2fa4e90f..230131bdc 100644 --- a/src/mem/cache/Cache.py +++ b/src/mem/cache/Cache.py @@ -1,4 +1,4 @@ -# Copyright (c) 2012-2013, 2015 ARM Limited +# Copyright (c) 2012-2013, 2015, 2018 ARM Limited # All rights reserved. # # The license below extends only to copyright in the software and shall @@ -120,3 +120,13 @@ class BaseCache(MemObject): class Cache(BaseCache): type = 'Cache' cxx_header = 'mem/cache/cache.hh' + + +class NoncoherentCache(BaseCache): + type = 'NoncoherentCache' + cxx_header = 'mem/cache/noncoherent_cache.hh' + + # This is typically a last level cache and any clean + # writebacks would be unnecessary traffic to the main memory. + writeback_clean = False + diff --git a/src/mem/cache/SConscript b/src/mem/cache/SConscript index 1c9b0027c..244d61dc2 100644 --- a/src/mem/cache/SConscript +++ b/src/mem/cache/SConscript @@ -33,10 +33,11 @@ Import('*') SimObject('Cache.py') Source('base.cc') -Source('cache.cc') Source('blk.cc') +Source('cache.cc') Source('mshr.cc') Source('mshr_queue.cc') +Source('noncoherent_cache.cc') Source('write_queue.cc') Source('write_queue_entry.cc') diff --git a/src/mem/cache/mshr.cc b/src/mem/cache/mshr.cc index e05ec7cde..f5b346ee8 100644 --- a/src/mem/cache/mshr.cc +++ b/src/mem/cache/mshr.cc @@ -310,11 +310,6 @@ MSHR::allocateTarget(PacketPtr pkt, Tick whenReady, Counter _order, // outstanding miss assert(pkt->cmd != MemCmd::HardPFReq); - // uncacheable accesses always allocate a new MSHR, and cacheable - // accesses ignore any uncacheable MSHRs, thus we should never - // have targets addded if originally allocated uncacheable - assert(!_isUncacheable); - // if there's a request already in service for this MSHR, we will // have to defer the new target until after the response if any of // the following are true: diff --git a/src/mem/cache/noncoherent_cache.cc b/src/mem/cache/noncoherent_cache.cc new file mode 100644 index 000000000..bf75be4d6 --- /dev/null +++ b/src/mem/cache/noncoherent_cache.cc @@ -0,0 +1,375 @@ +/* + * Copyright (c) 2010-2018 ARM Limited + * All rights reserved. + * + * The license below extends only to copyright in the software and shall + * not be construed as granting a license to any other intellectual + * property including but not limited to intellectual property relating + * to a hardware implementation of the functionality of the software + * licensed hereunder. You may use the software subject to the license + * terms below provided that you ensure that this notice is replicated + * unmodified and in its entirety in all distributions of the software, + * modified or unmodified, in source code or in binary form. + * + * Copyright (c) 2002-2005 The Regents of The University of Michigan + * Copyright (c) 2010,2015 Advanced Micro Devices, Inc. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer; + * redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution; + * neither the name of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Authors: Erik Hallnor + * Dave Greene + * Nathan Binkert + * Steve Reinhardt + * Ron Dreslinski + * Andreas Sandberg + * Nikos Nikoleris + */ + +/** + * @file + * Cache definitions. + */ + +#include "mem/cache/noncoherent_cache.hh" + +#include <cassert> + +#include "base/logging.hh" +#include "base/trace.hh" +#include "base/types.hh" +#include "debug/Cache.hh" +#include "mem/cache/blk.hh" +#include "mem/cache/mshr.hh" +#include "params/NoncoherentCache.hh" + +NoncoherentCache::NoncoherentCache(const NoncoherentCacheParams *p) + : BaseCache(p, p->system->cacheLineSize()) +{ +} + +void +NoncoherentCache::satisfyRequest(PacketPtr pkt, CacheBlk *blk, bool, bool) +{ + // As this a non-coherent cache located below the point of + // coherency, we do not expect requests that are typically used to + // keep caches coherent (e.g., InvalidateReq or UpdateReq). + assert(pkt->isRead() || pkt->isWrite()); + BaseCache::satisfyRequest(pkt, blk); +} + +bool +NoncoherentCache::access(PacketPtr pkt, CacheBlk *&blk, Cycles &lat, + PacketList &writebacks) +{ + bool success = BaseCache::access(pkt, blk, lat, writebacks); + + if (pkt->isWriteback() || pkt->cmd == MemCmd::WriteClean) { + assert(blk && blk->isValid()); + // Writeback and WriteClean can allocate and fill even if the + // referenced block was not present or it was invalid. If that + // is the case, make sure that the new block is marked as + // writable + blk->status |= BlkWritable; + } + + return success; +} + +void +NoncoherentCache::doWritebacks(PacketList& writebacks, Tick forward_time) +{ + while (!writebacks.empty()) { + PacketPtr wb_pkt = writebacks.front(); + allocateWriteBuffer(wb_pkt, forward_time); + writebacks.pop_front(); + } +} + +void +NoncoherentCache::doWritebacksAtomic(PacketList& writebacks) +{ + while (!writebacks.empty()) { + PacketPtr wb_pkt = writebacks.front(); + memSidePort.sendAtomic(wb_pkt); + writebacks.pop_front(); + delete wb_pkt; + } +} + +void +NoncoherentCache::handleTimingReqMiss(PacketPtr pkt, CacheBlk *blk, + Tick forward_time, Tick request_time) +{ + // miss + Addr blk_addr = pkt->getBlockAddr(blkSize); + MSHR *mshr = mshrQueue.findMatch(blk_addr, pkt->isSecure(), false); + + // We can always write to a non coherent cache if the block is + // present and therefore if we have reached this point then the + // block should not be in the cache. + assert(mshr || !blk || !blk->isValid()); + + BaseCache::handleTimingReqMiss(pkt, mshr, blk, forward_time, request_time); +} + +void +NoncoherentCache::recvTimingReq(PacketPtr pkt) +{ + panic_if(pkt->cacheResponding(), "Should not see packets where cache " + "is responding"); + + panic_if(!(pkt->isRead() || pkt->isWrite()), + "Should only see read and writes at non-coherent cache\n"); + + BaseCache::recvTimingReq(pkt); +} + +PacketPtr +NoncoherentCache::createMissPacket(PacketPtr cpu_pkt, CacheBlk *blk, + bool needs_writable) const +{ + // We also fill for writebacks from the coherent caches above us, + // and they do not need responses + assert(cpu_pkt->needsResponse()); + + // A miss can happen only due to missing block + assert(!blk || !blk->isValid()); + + PacketPtr pkt = new Packet(cpu_pkt->req, MemCmd::ReadReq, blkSize); + + // the packet should be block aligned + assert(pkt->getAddr() == pkt->getBlockAddr(blkSize)); + + pkt->allocate(); + DPRINTF(Cache, "%s created %s from %s\n", __func__, pkt->print(), + cpu_pkt->print()); + return pkt; +} + + +Cycles +NoncoherentCache::handleAtomicReqMiss(PacketPtr pkt, CacheBlk *blk, + PacketList &writebacks) +{ + PacketPtr bus_pkt = createMissPacket(pkt, blk, true); + DPRINTF(Cache, "Sending an atomic %s\n", bus_pkt->print()); + + Cycles latency = ticksToCycles(memSidePort.sendAtomic(bus_pkt)); + + assert(bus_pkt->isResponse()); + // At the moment the only supported downstream requests we issue + // are ReadReq and therefore here we should only see the + // corresponding responses + assert(bus_pkt->isRead()); + assert(pkt->cmd != MemCmd::UpgradeResp); + assert(!bus_pkt->isInvalidate()); + assert(!bus_pkt->hasSharers()); + + // We are now dealing with the response handling + DPRINTF(Cache, "Receive response: %s\n", bus_pkt->print()); + + if (!bus_pkt->isError()) { + // Any reponse that does not have an error should be filling, + // afterall it is a read response + DPRINTF(Cache, "Block for addr %#llx being updated in Cache\n", + bus_pkt->getAddr()); + blk = handleFill(bus_pkt, blk, writebacks, allocOnFill(bus_pkt->cmd)); + assert(blk); + } + satisfyRequest(pkt, blk); + + maintainClusivity(true, blk); + + // Use the separate bus_pkt to generate response to pkt and + // then delete it. + if (!pkt->isWriteback() && pkt->cmd != MemCmd::WriteClean) { + assert(pkt->needsResponse()); + pkt->makeAtomicResponse(); + if (bus_pkt->isError()) { + pkt->copyError(bus_pkt); + } + } + + delete bus_pkt; + + return latency; +} + +Tick +NoncoherentCache::recvAtomic(PacketPtr pkt) +{ + panic_if(pkt->cacheResponding(), "Should not see packets where cache " + "is responding"); + + panic_if(!(pkt->isRead() || pkt->isWrite()), + "Should only see read and writes at non-coherent cache\n"); + + return BaseCache::recvAtomic(pkt); +} + + +void +NoncoherentCache::functionalAccess(PacketPtr pkt, bool from_cpu_side) +{ + panic_if(!from_cpu_side, "Non-coherent cache received functional snoop" + " request\n"); + + BaseCache::functionalAccess(pkt, from_cpu_side); +} + +void +NoncoherentCache::serviceMSHRTargets(MSHR *mshr, const PacketPtr pkt, + CacheBlk *blk, PacketList &writebacks) +{ + MSHR::Target *initial_tgt = mshr->getTarget(); + // First offset for critical word first calculations + const int initial_offset = initial_tgt->pkt->getOffset(blkSize); + + MSHR::TargetList targets = mshr->extractServiceableTargets(pkt); + for (auto &target: targets) { + Packet *tgt_pkt = target.pkt; + + switch (target.source) { + case MSHR::Target::FromCPU: + // handle deferred requests comming from a cache or core + // above + + Tick completion_time; + // Here we charge on completion_time the delay of the xbar if the + // packet comes from it, charged on headerDelay. + completion_time = pkt->headerDelay; + + satisfyRequest(tgt_pkt, blk); + + // How many bytes past the first request is this one + int transfer_offset; + transfer_offset = tgt_pkt->getOffset(blkSize) - initial_offset; + if (transfer_offset < 0) { + transfer_offset += blkSize; + } + // If not critical word (offset) return payloadDelay. + // responseLatency is the latency of the return path + // from lower level caches/memory to an upper level cache or + // the core. + completion_time += clockEdge(responseLatency) + + (transfer_offset ? pkt->payloadDelay : 0); + + assert(tgt_pkt->req->masterId() < system->maxMasters()); + missLatency[tgt_pkt->cmdToIndex()][tgt_pkt->req->masterId()] += + completion_time - target.recvTime; + + tgt_pkt->makeTimingResponse(); + if (pkt->isError()) + tgt_pkt->copyError(pkt); + + // Reset the bus additional time as it is now accounted for + tgt_pkt->headerDelay = tgt_pkt->payloadDelay = 0; + cpuSidePort.schedTimingResp(tgt_pkt, completion_time, true); + break; + + case MSHR::Target::FromPrefetcher: + // handle deferred requests comming from a prefetcher + // attached to this cache + assert(tgt_pkt->cmd == MemCmd::HardPFReq); + + if (blk) + blk->status |= BlkHWPrefetched; + + // We have filled the block and the prefetcher does not + // require responses. + delete tgt_pkt->req; + delete tgt_pkt; + break; + + default: + // we should never see FromSnoop Targets as this is a + // non-coherent cache + panic("Illegal target->source enum %d\n", target.source); + } + } + + // Reponses are filling and bring in writable blocks, therefore + // there should be no deferred targets and all the non-deferred + // targets are now serviced. + assert(mshr->getNumTargets() == 0); +} + +void +NoncoherentCache::recvTimingResp(PacketPtr pkt) +{ + assert(pkt->isResponse()); + // At the moment the only supported downstream requests we issue + // are ReadReq and therefore here we should only see the + // corresponding responses + assert(pkt->isRead()); + assert(pkt->cmd != MemCmd::UpgradeResp); + assert(!pkt->isInvalidate()); + // This cache is non-coherent and any memories below are + // non-coherent too (non-coherent caches or the main memory), + // therefore the fetched block can be marked as writable. + assert(!pkt->hasSharers()); + + BaseCache::recvTimingResp(pkt); +} + +PacketPtr +NoncoherentCache::evictBlock(CacheBlk *blk) +{ + // A dirty block is always written back. + + // A clean block can we written back, if we turned on writebacks + // for clean blocks. This could be useful if there is a cache + // below and we want to make sure the block is cached but if the + // memory below is the main memory WritebackCleans are + // unnecessary. + + // If we clean writebacks are not enabled, we do not take any + // further action for evictions of clean blocks (i.e., CleanEvicts + // are unnecessary). + PacketPtr pkt = (blk->isDirty() || writebackClean) ? + writebackBlk(blk) : nullptr; + + invalidateBlock(blk); + + return pkt; +} + +void +NoncoherentCache::evictBlock(CacheBlk *blk, PacketList &writebacks) +{ + PacketPtr pkt = evictBlock(blk); + if (pkt) { + writebacks.push_back(pkt); + } +} + +NoncoherentCache* +NoncoherentCacheParams::create() +{ + assert(tags); + assert(replacement_policy); + + return new NoncoherentCache(this); +} diff --git a/src/mem/cache/noncoherent_cache.hh b/src/mem/cache/noncoherent_cache.hh new file mode 100644 index 000000000..09012ba10 --- /dev/null +++ b/src/mem/cache/noncoherent_cache.hh @@ -0,0 +1,133 @@ +/* + * Copyright (c) 2012-2018 ARM Limited + * All rights reserved. + * + * The license below extends only to copyright in the software and shall + * not be construed as granting a license to any other intellectual + * property including but not limited to intellectual property relating + * to a hardware implementation of the functionality of the software + * licensed hereunder. You may use the software subject to the license + * terms below provided that you ensure that this notice is replicated + * unmodified and in its entirety in all distributions of the software, + * modified or unmodified, in source code or in binary form. + * + * Copyright (c) 2002-2005 The Regents of The University of Michigan + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer; + * redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution; + * neither the name of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Authors: Erik Hallnor + * Dave Greene + * Steve Reinhardt + * Ron Dreslinski + * Andreas Hansson + * Nikos Nikoleris + */ + +/** + * @file + * Specifies a non-coherent cache. The non-coherent cache is expected + * to be located below the point of coherency. All valid blocks in the + * non-coherent cache can always be written to without any prior + * invalidations or snoops. + */ + +#ifndef __MEM_CACHE_NONCOHERENT_CACHE_HH__ +#define __MEM_CACHE_NONCOHERENT_CACHE_HH__ + +#include "base/logging.hh" +#include "base/types.hh" +#include "mem/cache/base.hh" +#include "mem/packet.hh" + +class CacheBlk; +class MSHR; +struct NoncoherentCacheParams; + +/** + * A non-coherent cache + */ +class NoncoherentCache : public BaseCache +{ + protected: + bool access(PacketPtr pkt, CacheBlk *&blk, Cycles &lat, + PacketList &writebacks) override; + + void handleTimingReqMiss(PacketPtr pkt, CacheBlk *blk, + Tick forward_time, + Tick request_time) override; + + void recvTimingReq(PacketPtr pkt) override; + + void doWritebacks(PacketList& writebacks, + Tick forward_time) override; + + void doWritebacksAtomic(PacketList& writebacks) override; + + void serviceMSHRTargets(MSHR *mshr, const PacketPtr pkt, + CacheBlk *blk, PacketList& writebacks) override; + + void recvTimingResp(PacketPtr pkt) override; + + void recvTimingSnoopReq(PacketPtr pkt) override { + panic("Unexpected timing snoop request %s", pkt->print()); + } + + void recvTimingSnoopResp(PacketPtr pkt) override { + panic("Unexpected timing snoop response %s", pkt->print()); + } + + Cycles handleAtomicReqMiss(PacketPtr pkt, CacheBlk *blk, + PacketList &writebacks) override; + + Tick recvAtomic(PacketPtr pkt) override; + + Tick recvAtomicSnoop(PacketPtr pkt) override { + panic("Unexpected atomic snoop request %s", pkt->print()); + } + + void functionalAccess(PacketPtr pkt, bool from_cpu_side) override; + + void satisfyRequest(PacketPtr pkt, CacheBlk *blk, + bool deferred_response = false, + bool pending_downgrade = false) override; + + /* + * Creates a new packet with the request to be send to the memory + * below. The noncoherent cache is below the point of coherence + * and therefore all fills bring in writable, therefore the + * needs_writeble parameter is ignored. + */ + PacketPtr createMissPacket(PacketPtr cpu_pkt, CacheBlk *blk, + bool needs_writable) const override; + + M5_NODISCARD PacketPtr evictBlock(CacheBlk *blk) override; + + void evictBlock(CacheBlk *blk, PacketList &writebacks) override; + + public: + NoncoherentCache(const NoncoherentCacheParams *p); +}; + +#endif // __MEM_CACHE_NONCOHERENTCACHE_HH__ diff --git a/src/mem/cache/queue.hh b/src/mem/cache/queue.hh index f6941e64a..f603ea84e 100644 --- a/src/mem/cache/queue.hh +++ b/src/mem/cache/queue.hh @@ -1,5 +1,5 @@ /* - * Copyright (c) 2012-2013, 2015-2016 ARM Limited + * Copyright (c) 2012-2013, 2015-2016, 2018 ARM Limited * All rights reserved. * * The license below extends only to copyright in the software and shall @@ -148,12 +148,15 @@ class Queue : public Drainable } /** - * Find the first WriteQueueEntry that matches the provided address. + * Find the first entry that matches the provided address. + * * @param blk_addr The block address to find. * @param is_secure True if the target memory space is secure. + * @param ignore_uncacheable Should uncacheables be ignored or not * @return Pointer to the matching WriteQueueEntry, null if not found. */ - Entry* findMatch(Addr blk_addr, bool is_secure) const + Entry* findMatch(Addr blk_addr, bool is_secure, + bool ignore_uncacheable = true) const { for (const auto& entry : allocatedList) { // we ignore any entries allocated for uncacheable @@ -162,8 +165,8 @@ class Queue : public Drainable // uncacheable entries, and we do not want normal // cacheable accesses being added to an WriteQueueEntry // serving an uncacheable access - if (!entry->isUncacheable() && entry->blkAddr == blk_addr && - entry->isSecure == is_secure) { + if (!(ignore_uncacheable && entry->isUncacheable()) && + entry->blkAddr == blk_addr && entry->isSecure == is_secure) { return entry; } } |