diff options
Diffstat (limited to 'src/mem/cache/miss')
| -rw-r--r-- | src/mem/cache/miss/blocking_buffer.cc | 245 | ||||
| -rw-r--r-- | src/mem/cache/miss/blocking_buffer.hh | 256 | ||||
| -rw-r--r-- | src/mem/cache/miss/miss_queue.cc | 757 | ||||
| -rw-r--r-- | src/mem/cache/miss/miss_queue.hh | 349 | ||||
| -rw-r--r-- | src/mem/cache/miss/mshr.cc | 182 | ||||
| -rw-r--r-- | src/mem/cache/miss/mshr.hh | 179 | ||||
| -rw-r--r-- | src/mem/cache/miss/mshr_queue.cc | 269 | ||||
| -rw-r--r-- | src/mem/cache/miss/mshr_queue.hh | 239 |
8 files changed, 2476 insertions, 0 deletions
diff --git a/src/mem/cache/miss/blocking_buffer.cc b/src/mem/cache/miss/blocking_buffer.cc new file mode 100644 index 000000000..10d53b109 --- /dev/null +++ b/src/mem/cache/miss/blocking_buffer.cc @@ -0,0 +1,245 @@ +/* + * Copyright (c) 2003-2005 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 + */ + +/** + * @file + * Definitions of a simple buffer for a blocking cache. + */ + +#include "cpu/smt.hh" //for maxThreadsPerCPU +#include "mem/cache/base_cache.hh" +#include "mem/cache/miss/blocking_buffer.hh" +#include "mem/cache/prefetch/base_prefetcher.hh" +#include "sim/eventq.hh" // for Event declaration. +#include "mem/request.hh" + +using namespace TheISA; + +/** + * @todo Move writebacks into shared BaseBuffer class. + */ +void +BlockingBuffer::regStats(const std::string &name) +{ + using namespace Stats; + writebacks + .init(maxThreadsPerCPU) + .name(name + ".writebacks") + .desc("number of writebacks") + .flags(total) + ; +} + +void +BlockingBuffer::setCache(BaseCache *_cache) +{ + cache = _cache; + blkSize = cache->getBlockSize(); +} + +void +BlockingBuffer::setPrefetcher(BasePrefetcher *_prefetcher) +{ + prefetcher = _prefetcher; +} +void +BlockingBuffer::handleMiss(Packet * &pkt, int blk_size, Tick time) +{ + Addr blk_addr = pkt->getAddr() & ~(Addr)(blk_size - 1); + if (pkt->isWrite() && (pkt->req->isUncacheable() || !writeAllocate || + !pkt->needsResponse())) { + if (!pkt->needsResponse()) { + wb.allocateAsBuffer(pkt); + } else { + wb.allocate(pkt->cmd, blk_addr, pkt->req->getAsid(), blk_size, pkt); + } + + memcpy(wb.pkt->getPtr<uint8_t>(), pkt->getPtr<uint8_t>(), blk_size); + + cache->setBlocked(Blocked_NoWBBuffers); + cache->setMasterRequest(Request_WB, time); + return; + } + + if (!pkt->needsResponse()) { + miss.allocateAsBuffer(pkt); + } else { + miss.allocate(pkt->cmd, blk_addr, pkt->req->getAsid(), blk_size, pkt); + } + if (!pkt->req->isUncacheable()) { + miss.pkt->flags |= CACHE_LINE_FILL; + } + cache->setBlocked(Blocked_NoMSHRs); + cache->setMasterRequest(Request_MSHR, time); +} + +Packet * +BlockingBuffer::getPacket() +{ + if (miss.pkt && !miss.inService) { + return miss.pkt; + } + return wb.pkt; +} + +void +BlockingBuffer::setBusCmd(Packet * &pkt, Packet::Command cmd) +{ + MSHR *mshr = (MSHR*) pkt->senderState; + mshr->originalCmd = pkt->cmd; + if (pkt->isCacheFill()) + pkt->cmdOverride(cmd); +} + +void +BlockingBuffer::restoreOrigCmd(Packet * &pkt) +{ + pkt->cmdOverride(((MSHR*)(pkt->senderState))->originalCmd); +} + +void +BlockingBuffer::markInService(Packet * &pkt) +{ + if (!pkt->isCacheFill() && pkt->isWrite()) { + // Forwarding a write/ writeback, don't need to change + // the command + assert((MSHR*)pkt->senderState == &wb); + cache->clearMasterRequest(Request_WB); + if (!pkt->needsResponse()) { + assert(wb.getNumTargets() == 0); + wb.deallocate(); + cache->clearBlocked(Blocked_NoWBBuffers); + } else { + wb.inService = true; + } + } else { + assert((MSHR*)pkt->senderState == &miss); + cache->clearMasterRequest(Request_MSHR); + if (!pkt->needsResponse()) { + assert(miss.getNumTargets() == 0); + miss.deallocate(); + cache->clearBlocked(Blocked_NoMSHRs); + } else { + //mark in service + miss.inService = true; + } + } +} + +void +BlockingBuffer::handleResponse(Packet * &pkt, Tick time) +{ + if (pkt->isCacheFill()) { + // targets were handled in the cache tags + assert((MSHR*)pkt->senderState == &miss); + miss.deallocate(); + cache->clearBlocked(Blocked_NoMSHRs); + } else { + if (((MSHR*)(pkt->senderState))->hasTargets()) { + // Should only have 1 target if we had any + assert(((MSHR*)(pkt->senderState))->getNumTargets() == 1); + Packet * target = ((MSHR*)(pkt->senderState))->getTarget(); + ((MSHR*)(pkt->senderState))->popTarget(); + if (pkt->isRead()) { + memcpy(target->getPtr<uint8_t>(), pkt->getPtr<uint8_t>(), target->getSize()); + } + cache->respond(target, time); + assert(!((MSHR*)(pkt->senderState))->hasTargets()); + } + + if (pkt->isWrite()) { + assert(((MSHR*)(pkt->senderState)) == &wb); + wb.deallocate(); + cache->clearBlocked(Blocked_NoWBBuffers); + } else { + miss.deallocate(); + cache->clearBlocked(Blocked_NoMSHRs); + } + } +} + +void +BlockingBuffer::squash(int threadNum) +{ + if (miss.threadNum == threadNum) { + Packet * target = miss.getTarget(); + miss.popTarget(); + assert(target->req->getThreadNum() == threadNum); + target = NULL; + assert(!miss.hasTargets()); + miss.ntargets=0; + if (!miss.inService) { + miss.deallocate(); + cache->clearBlocked(Blocked_NoMSHRs); + cache->clearMasterRequest(Request_MSHR); + } + } +} + +void +BlockingBuffer::doWriteback(Addr addr, int asid, + int size, uint8_t *data, bool compressed) +{ + // Generate request + Request * req = new Request(addr, size, 0); + Packet * pkt = new Packet(req, Packet::Writeback, -1); + pkt->allocate(); + if (data) { + memcpy(pkt->getPtr<uint8_t>(), data, size); + } + + if (compressed) { + pkt->flags |= COMPRESSED; + } + + ///All writebacks charged to same thread @todo figure this out + writebacks[pkt->req->getThreadNum()]++; + + wb.allocateAsBuffer(pkt); + cache->setMasterRequest(Request_WB, curTick); + cache->setBlocked(Blocked_NoWBBuffers); +} + + + +void +BlockingBuffer::doWriteback(Packet * &pkt) +{ + writebacks[pkt->req->getThreadNum()]++; + + wb.allocateAsBuffer(pkt); + + // Since allocate as buffer copies the request, + // need to copy data here. + memcpy(wb.pkt->getPtr<uint8_t>(), pkt->getPtr<uint8_t>(), pkt->getSize()); + + cache->setBlocked(Blocked_NoWBBuffers); + cache->setMasterRequest(Request_WB, curTick); +} diff --git a/src/mem/cache/miss/blocking_buffer.hh b/src/mem/cache/miss/blocking_buffer.hh new file mode 100644 index 000000000..39a06a377 --- /dev/null +++ b/src/mem/cache/miss/blocking_buffer.hh @@ -0,0 +1,256 @@ +/* + * Copyright (c) 2003-2005 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 + */ + +/** + * @file + * Declaration of a simple buffer for a blocking cache. + */ + +#ifndef __BLOCKING_BUFFER_HH__ +#define __BLOCKING_BUFFER_HH__ + +#include <vector> + +#include "mem/cache/miss/mshr.hh" +#include "base/statistics.hh" + +class BaseCache; +class BasePrefetcher; + +/** + * Miss and writeback storage for a blocking cache. + */ +class BlockingBuffer +{ +protected: + /** Miss storage. */ + MSHR miss; + /** WB storage. */ + MSHR wb; + + //Params + + /** Allocate on write misses. */ + const bool writeAllocate; + + /** Pointer to the parent cache. */ + BaseCache* cache; + + BasePrefetcher* prefetcher; + + /** Block size of the parent cache. */ + int blkSize; + + // Statistics + /** + * @addtogroup CacheStatistics + * @{ + */ + /** Number of blocks written back per thread. */ + Stats::Vector<> writebacks; + + /** + * @} + */ + +public: + /** + * Builds and initializes this buffer. + * @param write_allocate If true, treat write misses the same as reads. + */ + BlockingBuffer(bool write_allocate) + : writeAllocate(write_allocate) + { + } + + /** + * Register statistics for this object. + * @param name The name of the parent cache. + */ + void regStats(const std::string &name); + + /** + * Called by the parent cache to set the back pointer. + * @param _cache A pointer to the parent cache. + */ + void setCache(BaseCache *_cache); + + void setPrefetcher(BasePrefetcher *_prefetcher); + + /** + * Handle a cache miss properly. Requests the bus and marks the cache as + * blocked. + * @param req The request that missed in the cache. + * @param blk_size The block size of the cache. + * @param time The time the miss is detected. + */ + void handleMiss(Packet * &pkt, int blk_size, Tick time); + + /** + * Fetch the block for the given address and buffer the given target. + * @param addr The address to fetch. + * @param asid The address space of the address. + * @param blk_size The block size of the cache. + * @param time The time the miss is detected. + * @param target The target for the fetch. + */ + MSHR* fetchBlock(Addr addr, int asid, int blk_size, Tick time, + Packet * &target) + { + fatal("Unimplemented"); + } + + /** + * Selects a outstanding request to service. + * @return The request to service, NULL if none found. + */ + Packet * getPacket(); + + /** + * Set the command to the given bus command. + * @param req The request to update. + * @param cmd The bus command to use. + */ + void setBusCmd(Packet * &pkt, Packet::Command cmd); + + /** + * Restore the original command in case of a bus transmission error. + * @param req The request to reset. + */ + void restoreOrigCmd(Packet * &pkt); + + /** + * Marks a request as in service (sent on the bus). This can have side + * effect since storage for no response commands is deallocated once they + * are successfully sent. + * @param req The request that was sent on the bus. + */ + void markInService(Packet * &pkt); + + /** + * Frees the resources of the request and unblock the cache. + * @param req The request that has been satisfied. + * @param time The time when the request is satisfied. + */ + void handleResponse(Packet * &pkt, Tick time); + + /** + * Removes all outstanding requests for a given thread number. If a request + * has been sent to the bus, this function removes all of its targets. + * @param req->getThreadNum()ber The thread number of the requests to squash. + */ + void squash(int threadNum); + + /** + * Return the current number of outstanding misses. + * @return the number of outstanding misses. + */ + int getMisses() + { + return miss.getNumTargets(); + } + + /** + * Searches for the supplied address in the miss "queue". + * @param addr The address to look for. + * @param asid The address space id. + * @return A pointer to miss if it matches. + */ + MSHR* findMSHR(Addr addr, int asid) + { + if (miss.addr == addr && miss.pkt) + return &miss; + return NULL; + } + + /** + * Searches for the supplied address in the write buffer. + * @param addr The address to look for. + * @param asid The address space id. + * @param writes List of pointers to the matching writes. + * @return True if there is a matching write. + */ + bool findWrites(Addr addr, int asid, std::vector<MSHR*>& writes) + { + if (wb.addr == addr && wb.pkt) { + writes.push_back(&wb); + return true; + } + return false; + } + + + + /** + * Perform a writeback of dirty data to the given address. + * @param addr The address to write to. + * @param asid The address space id. + * @param size The number of bytes to write. + * @param data The data to write, can be NULL. + * @param compressed True if the data is compressed. + */ + void doWriteback(Addr addr, int asid, + int size, uint8_t *data, bool compressed); + + /** + * Perform a writeback request. + * @param req The writeback request. + */ + void doWriteback(Packet * &pkt); + + /** + * Returns true if there are outstanding requests. + * @return True if there are outstanding requests. + */ + bool havePending() + { + return !miss.inService || !wb.inService; + } + + /** + * Add a target to the given MSHR. This assumes it is in the miss queue. + * @param mshr The mshr to add a target to. + * @param req The target to add. + */ + void addTarget(MSHR *mshr, Packet * &pkt) + { + fatal("Shouldn't call this on a blocking buffer."); + } + + /** + * Dummy implmentation. + */ + MSHR* allocateTargetList(Addr addr, int asid) + { + fatal("Unimplemented"); + } +}; + +#endif // __BLOCKING_BUFFER_HH__ diff --git a/src/mem/cache/miss/miss_queue.cc b/src/mem/cache/miss/miss_queue.cc new file mode 100644 index 000000000..4a3dc1062 --- /dev/null +++ b/src/mem/cache/miss/miss_queue.cc @@ -0,0 +1,757 @@ +/* + * Copyright (c) 2003-2005 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 + * Ron Dreslinski + */ + +/** + * @file + * Miss and writeback queue definitions. + */ + +#include "cpu/smt.hh" //for maxThreadsPerCPU +#include "mem/cache/base_cache.hh" +#include "mem/cache/miss/miss_queue.hh" +#include "mem/cache/prefetch/base_prefetcher.hh" + +using namespace std; + +// simple constructor +/** + * @todo Remove the +16 from the write buffer constructor once we handle + * stalling on writebacks do to compression writes. + */ +MissQueue::MissQueue(int numMSHRs, int numTargets, int write_buffers, + bool write_allocate, bool prefetch_miss) + : mq(numMSHRs, 4), wb(write_buffers,numMSHRs+1000), numMSHR(numMSHRs), + numTarget(numTargets), writeBuffers(write_buffers), + writeAllocate(write_allocate), order(0), prefetchMiss(prefetch_miss) +{ + noTargetMSHR = NULL; +} + +void +MissQueue::regStats(const string &name) +{ + Request temp_req((Addr) NULL, 4, 0); + Packet::Command temp_cmd = Packet::ReadReq; + Packet temp_pkt(&temp_req, temp_cmd, 0); //@todo FIx command strings so this isn't neccessary + temp_pkt.allocate(); + + using namespace Stats; + + writebacks + .init(maxThreadsPerCPU) + .name(name + ".writebacks") + .desc("number of writebacks") + .flags(total) + ; + + // MSHR hit statistics + for (int access_idx = 0; access_idx < NUM_MEM_CMDS; ++access_idx) { + Packet::Command cmd = (Packet::Command)access_idx; + const string &cstr = temp_pkt.cmdIdxToString(cmd); + + mshr_hits[access_idx] + .init(maxThreadsPerCPU) + .name(name + "." + cstr + "_mshr_hits") + .desc("number of " + cstr + " MSHR hits") + .flags(total | nozero | nonan) + ; + } + + demandMshrHits + .name(name + ".demand_mshr_hits") + .desc("number of demand (read+write) MSHR hits") + .flags(total) + ; + demandMshrHits = mshr_hits[Packet::ReadReq] + mshr_hits[Packet::WriteReq]; + + overallMshrHits + .name(name + ".overall_mshr_hits") + .desc("number of overall MSHR hits") + .flags(total) + ; + overallMshrHits = demandMshrHits + mshr_hits[Packet::SoftPFReq] + + mshr_hits[Packet::HardPFReq]; + + // MSHR miss statistics + for (int access_idx = 0; access_idx < NUM_MEM_CMDS; ++access_idx) { + Packet::Command cmd = (Packet::Command)access_idx; + const string &cstr = temp_pkt.cmdIdxToString(cmd); + + mshr_misses[access_idx] + .init(maxThreadsPerCPU) + .name(name + "." + cstr + "_mshr_misses") + .desc("number of " + cstr + " MSHR misses") + .flags(total | nozero | nonan) + ; + } + + demandMshrMisses + .name(name + ".demand_mshr_misses") + .desc("number of demand (read+write) MSHR misses") + .flags(total) + ; + demandMshrMisses = mshr_misses[Packet::ReadReq] + mshr_misses[Packet::WriteReq]; + + overallMshrMisses + .name(name + ".overall_mshr_misses") + .desc("number of overall MSHR misses") + .flags(total) + ; + overallMshrMisses = demandMshrMisses + mshr_misses[Packet::SoftPFReq] + + mshr_misses[Packet::HardPFReq]; + + // MSHR miss latency statistics + for (int access_idx = 0; access_idx < NUM_MEM_CMDS; ++access_idx) { + Packet::Command cmd = (Packet::Command)access_idx; + const string &cstr = temp_pkt.cmdIdxToString(cmd); + + mshr_miss_latency[access_idx] + .init(maxThreadsPerCPU) + .name(name + "." + cstr + "_mshr_miss_latency") + .desc("number of " + cstr + " MSHR miss cycles") + .flags(total | nozero | nonan) + ; + } + + demandMshrMissLatency + .name(name + ".demand_mshr_miss_latency") + .desc("number of demand (read+write) MSHR miss cycles") + .flags(total) + ; + demandMshrMissLatency = mshr_miss_latency[Packet::ReadReq] + + mshr_miss_latency[Packet::WriteReq]; + + overallMshrMissLatency + .name(name + ".overall_mshr_miss_latency") + .desc("number of overall MSHR miss cycles") + .flags(total) + ; + overallMshrMissLatency = demandMshrMissLatency + + mshr_miss_latency[Packet::SoftPFReq] + mshr_miss_latency[Packet::HardPFReq]; + + // MSHR uncacheable statistics + for (int access_idx = 0; access_idx < NUM_MEM_CMDS; ++access_idx) { + Packet::Command cmd = (Packet::Command)access_idx; + const string &cstr = temp_pkt.cmdIdxToString(cmd); + + mshr_uncacheable[access_idx] + .init(maxThreadsPerCPU) + .name(name + "." + cstr + "_mshr_uncacheable") + .desc("number of " + cstr + " MSHR uncacheable") + .flags(total | nozero | nonan) + ; + } + + overallMshrUncacheable + .name(name + ".overall_mshr_uncacheable_misses") + .desc("number of overall MSHR uncacheable misses") + .flags(total) + ; + overallMshrUncacheable = mshr_uncacheable[Packet::ReadReq] + + mshr_uncacheable[Packet::WriteReq] + mshr_uncacheable[Packet::SoftPFReq] + + mshr_uncacheable[Packet::HardPFReq]; + + // MSHR miss latency statistics + for (int access_idx = 0; access_idx < NUM_MEM_CMDS; ++access_idx) { + Packet::Command cmd = (Packet::Command)access_idx; + const string &cstr = temp_pkt.cmdIdxToString(cmd); + + mshr_uncacheable_lat[access_idx] + .init(maxThreadsPerCPU) + .name(name + "." + cstr + "_mshr_uncacheable_latency") + .desc("number of " + cstr + " MSHR uncacheable cycles") + .flags(total | nozero | nonan) + ; + } + + overallMshrUncacheableLatency + .name(name + ".overall_mshr_uncacheable_latency") + .desc("number of overall MSHR uncacheable cycles") + .flags(total) + ; + overallMshrUncacheableLatency = mshr_uncacheable_lat[Packet::ReadReq] + + mshr_uncacheable_lat[Packet::WriteReq] + + mshr_uncacheable_lat[Packet::SoftPFReq] + + mshr_uncacheable_lat[Packet::HardPFReq]; + +#if 0 + // MSHR access formulas + for (int access_idx = 0; access_idx < NUM_MEM_CMDS; ++access_idx) { + Packet::Command cmd = (Packet::Command)access_idx; + const string &cstr = temp_pkt.cmdIdxToString(cmd); + + mshrAccesses[access_idx] + .name(name + "." + cstr + "_mshr_accesses") + .desc("number of " + cstr + " mshr accesses(hits+misses)") + .flags(total | nozero | nonan) + ; + mshrAccesses[access_idx] = + mshr_hits[access_idx] + mshr_misses[access_idx] + + mshr_uncacheable[access_idx]; + } + + demandMshrAccesses + .name(name + ".demand_mshr_accesses") + .desc("number of demand (read+write) mshr accesses") + .flags(total | nozero | nonan) + ; + demandMshrAccesses = demandMshrHits + demandMshrMisses; + + overallMshrAccesses + .name(name + ".overall_mshr_accesses") + .desc("number of overall (read+write) mshr accesses") + .flags(total | nozero | nonan) + ; + overallMshrAccesses = overallMshrHits + overallMshrMisses + + overallMshrUncacheable; +#endif + + // MSHR miss rate formulas + for (int access_idx = 0; access_idx < NUM_MEM_CMDS; ++access_idx) { + Packet::Command cmd = (Packet::Command)access_idx; + const string &cstr = temp_pkt.cmdIdxToString(cmd); + + mshrMissRate[access_idx] + .name(name + "." + cstr + "_mshr_miss_rate") + .desc("mshr miss rate for " + cstr + " accesses") + .flags(total | nozero | nonan) + ; + + mshrMissRate[access_idx] = + mshr_misses[access_idx] / cache->accesses[access_idx]; + } + + demandMshrMissRate + .name(name + ".demand_mshr_miss_rate") + .desc("mshr miss rate for demand accesses") + .flags(total) + ; + demandMshrMissRate = demandMshrMisses / cache->demandAccesses; + + overallMshrMissRate + .name(name + ".overall_mshr_miss_rate") + .desc("mshr miss rate for overall accesses") + .flags(total) + ; + overallMshrMissRate = overallMshrMisses / cache->overallAccesses; + + // mshrMiss latency formulas + for (int access_idx = 0; access_idx < NUM_MEM_CMDS; ++access_idx) { + Packet::Command cmd = (Packet::Command)access_idx; + const string &cstr = temp_pkt.cmdIdxToString(cmd); + + avgMshrMissLatency[access_idx] + .name(name + "." + cstr + "_avg_mshr_miss_latency") + .desc("average " + cstr + " mshr miss latency") + .flags(total | nozero | nonan) + ; + + avgMshrMissLatency[access_idx] = + mshr_miss_latency[access_idx] / mshr_misses[access_idx]; + } + + demandAvgMshrMissLatency + .name(name + ".demand_avg_mshr_miss_latency") + .desc("average overall mshr miss latency") + .flags(total) + ; + demandAvgMshrMissLatency = demandMshrMissLatency / demandMshrMisses; + + overallAvgMshrMissLatency + .name(name + ".overall_avg_mshr_miss_latency") + .desc("average overall mshr miss latency") + .flags(total) + ; + overallAvgMshrMissLatency = overallMshrMissLatency / overallMshrMisses; + + // mshrUncacheable latency formulas + for (int access_idx = 0; access_idx < NUM_MEM_CMDS; ++access_idx) { + Packet::Command cmd = (Packet::Command)access_idx; + const string &cstr = temp_pkt.cmdIdxToString(cmd); + + avgMshrUncacheableLatency[access_idx] + .name(name + "." + cstr + "_avg_mshr_uncacheable_latency") + .desc("average " + cstr + " mshr uncacheable latency") + .flags(total | nozero | nonan) + ; + + avgMshrUncacheableLatency[access_idx] = + mshr_uncacheable_lat[access_idx] / mshr_uncacheable[access_idx]; + } + + overallAvgMshrUncacheableLatency + .name(name + ".overall_avg_mshr_uncacheable_latency") + .desc("average overall mshr uncacheable latency") + .flags(total) + ; + overallAvgMshrUncacheableLatency = overallMshrUncacheableLatency / overallMshrUncacheable; + + mshr_cap_events + .init(maxThreadsPerCPU) + .name(name + ".mshr_cap_events") + .desc("number of times MSHR cap was activated") + .flags(total) + ; + + //software prefetching stats + soft_prefetch_mshr_full + .init(maxThreadsPerCPU) + .name(name + ".soft_prefetch_mshr_full") + .desc("number of mshr full events for SW prefetching instrutions") + .flags(total) + ; + + mshr_no_allocate_misses + .name(name +".no_allocate_misses") + .desc("Number of misses that were no-allocate") + ; + +} + +void +MissQueue::setCache(BaseCache *_cache) +{ + cache = _cache; + blkSize = cache->getBlockSize(); +} + +void +MissQueue::setPrefetcher(BasePrefetcher *_prefetcher) +{ + prefetcher = _prefetcher; +} + +MSHR* +MissQueue::allocateMiss(Packet * &pkt, int size, Tick time) +{ + MSHR* mshr = mq.allocate(pkt, blkSize); + mshr->order = order++; + if (!pkt->req->isUncacheable() ){//&& !pkt->isNoAllocate()) { + // Mark this as a cache line fill + mshr->pkt->flags |= CACHE_LINE_FILL; + } + if (mq.isFull()) { + cache->setBlocked(Blocked_NoMSHRs); + } + if (pkt->cmd != Packet::HardPFReq) { + //If we need to request the bus (not on HW prefetch), do so + cache->setMasterRequest(Request_MSHR, time); + } + return mshr; +} + + +MSHR* +MissQueue::allocateWrite(Packet * &pkt, int size, Tick time) +{ + MSHR* mshr = wb.allocate(pkt,blkSize); + mshr->order = order++; + +//REMOVING COMPRESSION FOR NOW +#if 0 + if (pkt->isCompressed()) { + mshr->pkt->deleteData(); + mshr->pkt->actualSize = pkt->actualSize; + mshr->pkt->data = new uint8_t[pkt->actualSize]; + memcpy(mshr->pkt->data, pkt->data, pkt->actualSize); + } else { +#endif + memcpy(mshr->pkt->getPtr<uint8_t>(), pkt->getPtr<uint8_t>(), pkt->getSize()); + //{ + + if (wb.isFull()) { + cache->setBlocked(Blocked_NoWBBuffers); + } + + cache->setMasterRequest(Request_WB, time); + + return mshr; +} + + +/** + * @todo Remove SW prefetches on mshr hits. + */ +void +MissQueue::handleMiss(Packet * &pkt, int blkSize, Tick time) +{ +// if (!cache->isTopLevel()) + if (prefetchMiss) prefetcher->handleMiss(pkt, time); + + int size = blkSize; + Addr blkAddr = pkt->getAddr() & ~(Addr)(blkSize-1); + MSHR* mshr = NULL; + if (!pkt->req->isUncacheable()) { + mshr = mq.findMatch(blkAddr, pkt->req->getAsid()); + if (mshr) { + //@todo remove hw_pf here + mshr_hits[pkt->cmdToIndex()][pkt->req->getThreadNum()]++; + if (mshr->threadNum != pkt->req->getThreadNum()) { + mshr->threadNum = -1; + } + mq.allocateTarget(mshr, pkt); + if (mshr->pkt->isNoAllocate() && !pkt->isNoAllocate()) { + //We are adding an allocate after a no-allocate + mshr->pkt->flags &= ~NO_ALLOCATE; + } + if (mshr->getNumTargets() == numTarget) { + noTargetMSHR = mshr; + cache->setBlocked(Blocked_NoTargets); + mq.moveToFront(mshr); + } + return; + } + if (pkt->isNoAllocate()) { + //Count no-allocate requests differently + mshr_no_allocate_misses++; + } + else { + mshr_misses[pkt->cmdToIndex()][pkt->req->getThreadNum()]++; + } + } else { + //Count uncacheable accesses + mshr_uncacheable[pkt->cmdToIndex()][pkt->req->getThreadNum()]++; + size = pkt->getSize(); + } + if (pkt->isWrite() && (pkt->req->isUncacheable() || !writeAllocate || + !pkt->needsResponse())) { + /** + * @todo Add write merging here. + */ + mshr = allocateWrite(pkt, blkSize, time); + return; + } + + mshr = allocateMiss(pkt, blkSize, time); +} + +MSHR* +MissQueue::fetchBlock(Addr addr, int asid, int blk_size, Tick time, + Packet * &target) +{ + Addr blkAddr = addr & ~(Addr)(blk_size - 1); + assert(mq.findMatch(addr, asid) == NULL); + MSHR *mshr = mq.allocateFetch(blkAddr, asid, blk_size, target); + mshr->order = order++; + mshr->pkt->flags |= CACHE_LINE_FILL; + if (mq.isFull()) { + cache->setBlocked(Blocked_NoMSHRs); + } + cache->setMasterRequest(Request_MSHR, time); + return mshr; +} + +Packet * +MissQueue::getPacket() +{ + Packet * pkt = mq.getReq(); + if (((wb.isFull() && wb.inServiceMSHRs == 0) || !pkt || + pkt->time > curTick) && wb.havePending()) { + pkt = wb.getReq(); + // Need to search for earlier miss. + MSHR *mshr = mq.findPending(pkt); + if (mshr && mshr->order < ((MSHR*)(pkt->senderState))->order) { + // Service misses in order until conflict is cleared. + return mq.getReq(); + } + } + if (pkt) { + MSHR* mshr = wb.findPending(pkt); + if (mshr /*&& mshr->order < pkt->senderState->order*/) { + // The only way this happens is if we are + // doing a write and we didn't have permissions + // then subsequently saw a writeback(owned got evicted) + // We need to make sure to perform the writeback first + // To preserve the dirty data, then we can issue the write + return wb.getReq(); + } + } + else if (!mq.isFull()){ + //If we have a miss queue slot, we can try a prefetch + pkt = prefetcher->getPacket(); + if (pkt) { + //Update statistic on number of prefetches issued (hwpf_mshr_misses) + mshr_misses[pkt->cmdToIndex()][pkt->req->getThreadNum()]++; + //It will request the bus for the future, but should clear that immedieatley + allocateMiss(pkt, pkt->getSize(), curTick); + pkt = mq.getReq(); + assert(pkt); //We should get back a req b/c we just put one in + } + } + return pkt; +} + +void +MissQueue::setBusCmd(Packet * &pkt, Packet::Command cmd) +{ + assert(pkt->senderState != 0); + MSHR * mshr = (MSHR*)pkt->senderState; + mshr->originalCmd = pkt->cmd; + if (pkt->isCacheFill() || pkt->isNoAllocate()) + pkt->cmd = cmd; +} + +void +MissQueue::restoreOrigCmd(Packet * &pkt) +{ + pkt->cmd = ((MSHR*)(pkt->senderState))->originalCmd; +} + +void +MissQueue::markInService(Packet * &pkt) +{ + assert(pkt->senderState != 0); + bool unblock = false; + BlockedCause cause = NUM_BLOCKED_CAUSES; + + /** + * @todo Should include MSHRQueue pointer in MSHR to select the correct + * one. + */ + if ((!pkt->isCacheFill() && pkt->isWrite())) { + // Forwarding a write/ writeback, don't need to change + // the command + unblock = wb.isFull(); + wb.markInService((MSHR*)pkt->senderState); + if (!wb.havePending()){ + cache->clearMasterRequest(Request_WB); + } + if (unblock) { + // Do we really unblock? + unblock = !wb.isFull(); + cause = Blocked_NoWBBuffers; + } + } else { + unblock = mq.isFull(); + mq.markInService((MSHR*)pkt->senderState); + if (!mq.havePending()){ + cache->clearMasterRequest(Request_MSHR); + } + if (((MSHR*)(pkt->senderState))->originalCmd == Packet::HardPFReq) { + DPRINTF(HWPrefetch, "%s:Marking a HW_PF in service\n", + cache->name()); + //Also clear pending if need be + if (!prefetcher->havePending()) + { + cache->clearMasterRequest(Request_PF); + } + } + if (unblock) { + unblock = !mq.isFull(); + cause = Blocked_NoMSHRs; + } + } + if (unblock) { + cache->clearBlocked(cause); + } +} + + +void +MissQueue::handleResponse(Packet * &pkt, Tick time) +{ + MSHR* mshr = (MSHR*)pkt->senderState; + if (((MSHR*)(pkt->senderState))->originalCmd == Packet::HardPFReq) { + DPRINTF(HWPrefetch, "%s:Handling the response to a HW_PF\n", + cache->name()); + } +#ifndef NDEBUG + int num_targets = mshr->getNumTargets(); +#endif + + bool unblock = false; + bool unblock_target = false; + BlockedCause cause = NUM_BLOCKED_CAUSES; + + if (pkt->isCacheFill() && !pkt->isNoAllocate()) { + mshr_miss_latency[mshr->originalCmd][pkt->req->getThreadNum()] += + curTick - pkt->time; + // targets were handled in the cache tags + if (mshr == noTargetMSHR) { + // we always clear at least one target + unblock_target = true; + cause = Blocked_NoTargets; + noTargetMSHR = NULL; + } + + if (mshr->hasTargets()) { + // Didn't satisfy all the targets, need to resend + Packet::Command cmd = mshr->getTarget()->cmd; + mq.markPending(mshr, cmd); + mshr->order = order++; + cache->setMasterRequest(Request_MSHR, time); + } + else { + unblock = mq.isFull(); + mq.deallocate(mshr); + if (unblock) { + unblock = !mq.isFull(); + cause = Blocked_NoMSHRs; + } + } + } else { + if (pkt->req->isUncacheable()) { + mshr_uncacheable_lat[pkt->cmd][pkt->req->getThreadNum()] += + curTick - pkt->time; + } + if (mshr->hasTargets() && pkt->req->isUncacheable()) { + // Should only have 1 target if we had any + assert(num_targets == 1); + Packet * target = mshr->getTarget(); + mshr->popTarget(); + if (pkt->isRead()) { + memcpy(target->getPtr<uint8_t>(), pkt->getPtr<uint8_t>(), + target->getSize()); + } + cache->respond(target, time); + assert(!mshr->hasTargets()); + } + else if (mshr->hasTargets()) { + //Must be a no_allocate with possibly more than one target + assert(mshr->pkt->isNoAllocate()); + while (mshr->hasTargets()) { + Packet * target = mshr->getTarget(); + mshr->popTarget(); + if (pkt->isRead()) { + memcpy(target->getPtr<uint8_t>(), pkt->getPtr<uint8_t>(), + target->getSize()); + } + cache->respond(target, time); + } + } + + if (pkt->isWrite()) { + // If the wrtie buffer is full, we might unblock now + unblock = wb.isFull(); + wb.deallocate(mshr); + if (unblock) { + // Did we really unblock? + unblock = !wb.isFull(); + cause = Blocked_NoWBBuffers; + } + } else { + unblock = mq.isFull(); + mq.deallocate(mshr); + if (unblock) { + unblock = !mq.isFull(); + cause = Blocked_NoMSHRs; + } + } + } + if (unblock || unblock_target) { + cache->clearBlocked(cause); + } +} + +void +MissQueue::squash(int threadNum) +{ + bool unblock = false; + BlockedCause cause = NUM_BLOCKED_CAUSES; + + if (noTargetMSHR && noTargetMSHR->threadNum == threadNum) { + noTargetMSHR = NULL; + unblock = true; + cause = Blocked_NoTargets; + } + if (mq.isFull()) { + unblock = true; + cause = Blocked_NoMSHRs; + } + mq.squash(threadNum); + if (!mq.havePending()) { + cache->clearMasterRequest(Request_MSHR); + } + if (unblock && !mq.isFull()) { + cache->clearBlocked(cause); + } + +} + +MSHR* +MissQueue::findMSHR(Addr addr, int asid) const +{ + return mq.findMatch(addr,asid); +} + +bool +MissQueue::findWrites(Addr addr, int asid, vector<MSHR*> &writes) const +{ + return wb.findMatches(addr,asid,writes); +} + +void +MissQueue::doWriteback(Addr addr, int asid, + int size, uint8_t *data, bool compressed) +{ + // Generate request + Request * req = new Request(addr, size, 0); + Packet * pkt = new Packet(req, Packet::Writeback, -1); + pkt->allocate(); + if (data) { + memcpy(pkt->getPtr<uint8_t>(), data, size); + } + + if (compressed) { + pkt->flags |= COMPRESSED; + } + + ///All writebacks charged to same thread @todo figure this out + writebacks[pkt->req->getThreadNum()]++; + + allocateWrite(pkt, 0, curTick); +} + + +void +MissQueue::doWriteback(Packet * &pkt) +{ + writebacks[pkt->req->getThreadNum()]++; + allocateWrite(pkt, 0, curTick); +} + + +MSHR* +MissQueue::allocateTargetList(Addr addr, int asid) +{ + MSHR* mshr = mq.allocateTargetList(addr, asid, blkSize); + mshr->pkt->flags |= CACHE_LINE_FILL; + if (mq.isFull()) { + cache->setBlocked(Blocked_NoMSHRs); + } + return mshr; +} + +bool +MissQueue::havePending() +{ + return mq.havePending() || wb.havePending() || prefetcher->havePending(); +} diff --git a/src/mem/cache/miss/miss_queue.hh b/src/mem/cache/miss/miss_queue.hh new file mode 100644 index 000000000..b88b7038c --- /dev/null +++ b/src/mem/cache/miss/miss_queue.hh @@ -0,0 +1,349 @@ +/* + * Copyright (c) 2003-2005 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 + */ + +/** + * @file + * Miss and writeback queue declarations. + */ + +#ifndef __MISS_QUEUE_HH__ +#define __MISS_QUEUE_HH__ + +#include <vector> + +#include "mem/cache/miss/mshr.hh" +#include "mem/cache/miss/mshr_queue.hh" +#include "base/statistics.hh" + +class BaseCache; +class BasePrefetcher; +/** + * Manages cache misses and writebacks. Contains MSHRs to store miss data + * and the writebuffer for writes/writebacks. + * @todo need to handle data on writes better (encapsulate). + * @todo need to make replacements/writebacks happen in Cache::access + */ +class MissQueue +{ + protected: + /** The MSHRs. */ + MSHRQueue mq; + /** Write Buffer. */ + MSHRQueue wb; + + // PARAMTERS + + /** The number of MSHRs in the miss queue. */ + const int numMSHR; + /** The number of targets for each MSHR. */ + const int numTarget; + /** The number of write buffers. */ + const int writeBuffers; + /** True if the cache should allocate on a write miss. */ + const bool writeAllocate; + /** Pointer to the parent cache. */ + BaseCache* cache; + + /** The Prefetcher */ + BasePrefetcher *prefetcher; + + /** The block size of the parent cache. */ + int blkSize; + + /** Increasing order number assigned to each incoming request. */ + uint64_t order; + + bool prefetchMiss; + + // Statistics + /** + * @addtogroup CacheStatistics + * @{ + */ + /** Number of blocks written back per thread. */ + Stats::Vector<> writebacks; + + /** Number of misses that hit in the MSHRs per command and thread. */ + Stats::Vector<> mshr_hits[NUM_MEM_CMDS]; + /** Demand misses that hit in the MSHRs. */ + Stats::Formula demandMshrHits; + /** Total number of misses that hit in the MSHRs. */ + Stats::Formula overallMshrHits; + + /** Number of misses that miss in the MSHRs, per command and thread. */ + Stats::Vector<> mshr_misses[NUM_MEM_CMDS]; + /** Demand misses that miss in the MSHRs. */ + Stats::Formula demandMshrMisses; + /** Total number of misses that miss in the MSHRs. */ + Stats::Formula overallMshrMisses; + + /** Number of misses that miss in the MSHRs, per command and thread. */ + Stats::Vector<> mshr_uncacheable[NUM_MEM_CMDS]; + /** Total number of misses that miss in the MSHRs. */ + Stats::Formula overallMshrUncacheable; + + /** Total cycle latency of each MSHR miss, per command and thread. */ + Stats::Vector<> mshr_miss_latency[NUM_MEM_CMDS]; + /** Total cycle latency of demand MSHR misses. */ + Stats::Formula demandMshrMissLatency; + /** Total cycle latency of overall MSHR misses. */ + Stats::Formula overallMshrMissLatency; + + /** Total cycle latency of each MSHR miss, per command and thread. */ + Stats::Vector<> mshr_uncacheable_lat[NUM_MEM_CMDS]; + /** Total cycle latency of overall MSHR misses. */ + Stats::Formula overallMshrUncacheableLatency; + + /** The total number of MSHR accesses per command and thread. */ + Stats::Formula mshrAccesses[NUM_MEM_CMDS]; + /** The total number of demand MSHR accesses. */ + Stats::Formula demandMshrAccesses; + /** The total number of MSHR accesses. */ + Stats::Formula overallMshrAccesses; + + /** The miss rate in the MSHRs pre command and thread. */ + Stats::Formula mshrMissRate[NUM_MEM_CMDS]; + /** The demand miss rate in the MSHRs. */ + Stats::Formula demandMshrMissRate; + /** The overall miss rate in the MSHRs. */ + Stats::Formula overallMshrMissRate; + + /** The average latency of an MSHR miss, per command and thread. */ + Stats::Formula avgMshrMissLatency[NUM_MEM_CMDS]; + /** The average latency of a demand MSHR miss. */ + Stats::Formula demandAvgMshrMissLatency; + /** The average overall latency of an MSHR miss. */ + Stats::Formula overallAvgMshrMissLatency; + + /** The average latency of an MSHR miss, per command and thread. */ + Stats::Formula avgMshrUncacheableLatency[NUM_MEM_CMDS]; + /** The average overall latency of an MSHR miss. */ + Stats::Formula overallAvgMshrUncacheableLatency; + + /** The number of times a thread hit its MSHR cap. */ + Stats::Vector<> mshr_cap_events; + /** The number of times software prefetches caused the MSHR to block. */ + Stats::Vector<> soft_prefetch_mshr_full; + + Stats::Scalar<> mshr_no_allocate_misses; + + /** + * @} + */ + + private: + /** Pointer to the MSHR that has no targets. */ + MSHR* noTargetMSHR; + + /** + * Allocate a new MSHR to handle the provided miss. + * @param req The miss to buffer. + * @param size The number of bytes to fetch. + * @param time The time the miss occurs. + * @return A pointer to the new MSHR. + */ + MSHR* allocateMiss(Packet * &pkt, int size, Tick time); + + /** + * Allocate a new WriteBuffer to handle the provided write. + * @param req The write to handle. + * @param size The number of bytes to write. + * @param time The time the write occurs. + * @return A pointer to the new write buffer. + */ + MSHR* allocateWrite(Packet * &pkt, int size, Tick time); + + public: + /** + * Simple Constructor. Initializes all needed internal storage and sets + * parameters. + * @param numMSHRs The number of outstanding misses to handle. + * @param numTargets The number of outstanding targets to each miss. + * @param write_buffers The number of outstanding writes to handle. + * @param write_allocate If true, treat write misses the same as reads. + */ + MissQueue(int numMSHRs, int numTargets, int write_buffers, + bool write_allocate, bool prefetch_miss); + + /** + * Deletes all allocated internal storage. + */ + ~MissQueue(); + + /** + * Register statistics for this object. + * @param name The name of the parent cache. + */ + void regStats(const std::string &name); + + /** + * Called by the parent cache to set the back pointer. + * @param _cache A pointer to the parent cache. + */ + void setCache(BaseCache *_cache); + + void setPrefetcher(BasePrefetcher *_prefetcher); + + /** + * Handle a cache miss properly. Either allocate an MSHR for the request, + * or forward it through the write buffer. + * @param req The request that missed in the cache. + * @param blk_size The block size of the cache. + * @param time The time the miss is detected. + */ + void handleMiss(Packet * &pkt, int blk_size, Tick time); + + /** + * Fetch the block for the given address and buffer the given target. + * @param addr The address to fetch. + * @param asid The address space of the address. + * @param blk_size The block size of the cache. + * @param time The time the miss is detected. + * @param target The target for the fetch. + */ + MSHR* fetchBlock(Addr addr, int asid, int blk_size, Tick time, + Packet * &target); + + /** + * Selects a outstanding request to service. + * @return The request to service, NULL if none found. + */ + Packet * getPacket(); + + /** + * Set the command to the given bus command. + * @param req The request to update. + * @param cmd The bus command to use. + */ + void setBusCmd(Packet * &pkt, Packet::Command cmd); + + /** + * Restore the original command in case of a bus transmission error. + * @param req The request to reset. + */ + void restoreOrigCmd(Packet * &pkt); + + /** + * Marks a request as in service (sent on the bus). This can have side + * effect since storage for no response commands is deallocated once they + * are successfully sent. + * @param req The request that was sent on the bus. + */ + void markInService(Packet * &pkt); + + /** + * Collect statistics and free resources of a satisfied request. + * @param req The request that has been satisfied. + * @param time The time when the request is satisfied. + */ + void handleResponse(Packet * &pkt, Tick time); + + /** + * Removes all outstanding requests for a given thread number. If a request + * has been sent to the bus, this function removes all of its targets. + * @param req->getThreadNum()ber The thread number of the requests to squash. + */ + void squash(int threadNum); + + /** + * Return the current number of outstanding misses. + * @return the number of outstanding misses. + */ + int getMisses() + { + return mq.getAllocatedTargets(); + } + + /** + * Searches for the supplied address in the miss queue. + * @param addr The address to look for. + * @param asid The address space id. + * @return The MSHR that contains the address, NULL if not found. + * @warning Currently only searches the miss queue. If non write allocate + * might need to search the write buffer for coherence. + */ + MSHR* findMSHR(Addr addr, int asid) const; + + /** + * Searches for the supplied address in the write buffer. + * @param addr The address to look for. + * @param asid The address space id. + * @param writes The list of writes that match the address. + * @return True if any writes are found + */ + bool findWrites(Addr addr, int asid, std::vector<MSHR*>& writes) const; + + /** + * Perform a writeback of dirty data to the given address. + * @param addr The address to write to. + * @param asid The address space id. + * @param xc The execution context of the address space. + * @param size The number of bytes to write. + * @param data The data to write, can be NULL. + * @param compressed True if the data is compressed. + */ + void doWriteback(Addr addr, int asid, + int size, uint8_t *data, bool compressed); + + /** + * Perform the given writeback request. + * @param req The writeback request. + */ + void doWriteback(Packet * &pkt); + + /** + * Returns true if there are outstanding requests. + * @return True if there are outstanding requests. + */ + bool havePending(); + + /** + * Add a target to the given MSHR. This assumes it is in the miss queue. + * @param mshr The mshr to add a target to. + * @param req The target to add. + */ + void addTarget(MSHR *mshr, Packet * &pkt) + { + mq.allocateTarget(mshr, pkt); + } + + /** + * Allocate a MSHR to hold a list of targets to a block involved in a copy. + * If the block is marked done then the MSHR already holds the data to + * fill the block. Otherwise the block needs to be fetched. + * @param addr The address to buffer. + * @param asid The address space ID. + * @return A pointer to the allocated MSHR. + */ + MSHR* allocateTargetList(Addr addr, int asid); + +}; + +#endif //__MISS_QUEUE_HH__ diff --git a/src/mem/cache/miss/mshr.cc b/src/mem/cache/miss/mshr.cc new file mode 100644 index 000000000..db2f40c56 --- /dev/null +++ b/src/mem/cache/miss/mshr.cc @@ -0,0 +1,182 @@ +/* + * 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 + */ + +/** + * @file + * Miss Status and Handling Register (MSHR) definitions. + */ + +#include <assert.h> +#include <string> +#include <vector> + +#include "mem/cache/miss/mshr.hh" +#include "sim/root.hh" // for curTick +#include "sim/host.hh" +#include "base/misc.hh" +#include "mem/cache/cache.hh" + +using namespace std; + +MSHR::MSHR() +{ + inService = false; + ntargets = 0; + threadNum = -1; +} + +void +MSHR::allocate(Packet::Command cmd, Addr _addr, int _asid, int size, + Packet * &target) +{ + addr = _addr; + if (target) + { + //Have a request, just use it + pkt = new Packet(target->req, cmd, Packet::Broadcast, size); + pkt->time = curTick; + pkt->allocate(); + pkt->senderState = (Packet::SenderState *)this; + allocateTarget(target); + } + else + { + //need a request first + Request * req = new Request(); + req->setPhys(addr, size, 0); + //Thread context?? + pkt = new Packet(req, cmd, Packet::Broadcast, size); + pkt->time = curTick; + pkt->allocate(); + pkt->senderState = (Packet::SenderState *)this; + } +} + +// Since we aren't sure if data is being used, don't copy here. +/** + * @todo When we have a "global" data flag, might want to copy data here. + */ +void +MSHR::allocateAsBuffer(Packet * &target) +{ + addr = target->getAddr(); + asid = target->req->getAsid(); + threadNum = target->req->getThreadNum(); + pkt = new Packet(target->req, target->cmd, -1); + pkt->allocate(); + pkt->senderState = (Packet::SenderState*)this; + pkt->time = curTick; +} + +void +MSHR::deallocate() +{ + assert(targets.empty()); + assert(ntargets == 0); + pkt = NULL; + inService = false; + allocIter = NULL; + readyIter = NULL; +} + +/* + * Adds a target to an MSHR + */ +void +MSHR::allocateTarget(Packet * &target) +{ + //If we append an invalidate and we issued a read to the bus, + //but now have some pending writes, we need to move + //the invalidate to before the first non-read + if (inService && pkt->isRead() && target->isInvalidate()) { + std::list<Packet *> temp; + + while (!targets.empty()) { + if (!targets.front()->isRead()) break; + //Place on top of temp stack + temp.push_front(targets.front()); + //Remove from targets + targets.pop_front(); + } + + //Now that we have all the reads off until first non-read, we can + //place the invalidate on + targets.push_front(target); + + //Now we pop off the temp_stack and put them back + while (!temp.empty()) { + targets.push_front(temp.front()); + temp.pop_front(); + } + } + else { + targets.push_back(target); + } + + ++ntargets; + assert(targets.size() == ntargets); + /** + * @todo really prioritize the target commands. + */ + + if (!inService && target->isWrite()) { + pkt->cmd = Packet::WriteReq; + } +} + + + +void +MSHR::dump() +{ + ccprintf(cerr, + "inService: %d thread: %d\n" + "Addr: %x asid: %d ntargets %d\n" + "Targets:\n", + inService, threadNum, addr, asid, ntargets); + + TargetListIterator tar_it = targets.begin(); + for (int i = 0; i < ntargets; i++) { + assert(tar_it != targets.end()); + + ccprintf(cerr, "\t%d: Addr: %x cmd: %d\n", + i, (*tar_it)->getAddr(), (*tar_it)->cmdToIndex()); + + tar_it++; + } + ccprintf(cerr, "\n"); +} + +MSHR::~MSHR() +{ + if (pkt) + pkt = NULL; +} diff --git a/src/mem/cache/miss/mshr.hh b/src/mem/cache/miss/mshr.hh new file mode 100644 index 000000000..167aa26cd --- /dev/null +++ b/src/mem/cache/miss/mshr.hh @@ -0,0 +1,179 @@ +/* + * 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 + */ + +/** + * @file + * Miss Status and Handling Register (MSHR) declaration. + */ + +#ifndef __MSHR_HH__ +#define __MSHR_HH__ + +#include "mem/packet.hh" +#include <list> +#include <deque> + +class MSHR; + +/** + * Miss Status and handling Register. This class keeps all the information + * needed to handle a cache miss including a list of target requests. + */ +class MSHR { + public: + /** Defines the Data structure of the MSHR targetlist. */ + typedef std::list<Packet *> TargetList; + /** Target list iterator. */ + typedef std::list<Packet *>::iterator TargetListIterator; + /** A list of MSHRs. */ + typedef std::list<MSHR *> List; + /** MSHR list iterator. */ + typedef List::iterator Iterator; + /** MSHR list const_iterator. */ + typedef List::const_iterator ConstIterator; + + /** Address of the miss. */ + Addr addr; + /** Adress space id of the miss. */ + short asid; + /** True if the request has been sent to the bus. */ + bool inService; + /** Thread number of the miss. */ + int threadNum; + /** The request that is forwarded to the next level of the hierarchy. */ + Packet * pkt; + /** The number of currently allocated targets. */ + short ntargets; + /** The original requesting command. */ + Packet::Command originalCmd; + /** Order number of assigned by the miss queue. */ + uint64_t order; + + /** + * Pointer to this MSHR on the ready list. + * @sa MissQueue, MSHRQueue::readyList + */ + Iterator readyIter; + /** + * Pointer to this MSHR on the allocated list. + * @sa MissQueue, MSHRQueue::allocatedList + */ + Iterator allocIter; + +private: + /** List of all requests that match the address */ + TargetList targets; + +public: + /** + * Allocate a miss to this MSHR. + * @param cmd The requesting command. + * @param addr The address of the miss. + * @param asid The address space id of the miss. + * @param size The number of bytes to request. + * @param req The original miss. + */ + void allocate(Packet::Command cmd, Addr addr, int asid, int size, + Packet * &pkt); + + /** + * Allocate this MSHR as a buffer for the given request. + * @param target The memory request to buffer. + */ + void allocateAsBuffer(Packet * &target); + + /** + * Mark this MSHR as free. + */ + void deallocate(); + + /** + * Add a request to the list of targets. + * @param target The target. + */ + void allocateTarget(Packet * &target); + + /** A simple constructor. */ + MSHR(); + /** A simple destructor. */ + ~MSHR(); + + /** + * Returns the current number of allocated targets. + * @return The current number of allocated targets. + */ + int getNumTargets() + { + return(ntargets); + } + + /** + * Returns a pointer to the target list. + * @return a pointer to the target list. + */ + TargetList* getTargetList() + { + return &targets; + } + + /** + * Returns a reference to the first target. + * @return A pointer to the first target. + */ + Packet * getTarget() + { + return targets.front(); + } + + /** + * Pop first target. + */ + void popTarget() + { + --ntargets; + targets.pop_front(); + } + + /** + * Returns true if there are targets left. + * @return true if there are targets + */ + bool hasTargets() + { + return !targets.empty(); + } + + /** + * Prints the contents of this MSHR to stderr. + */ + void dump(); +}; + +#endif //__MSHR_HH__ diff --git a/src/mem/cache/miss/mshr_queue.cc b/src/mem/cache/miss/mshr_queue.cc new file mode 100644 index 000000000..6516a99f8 --- /dev/null +++ b/src/mem/cache/miss/mshr_queue.cc @@ -0,0 +1,269 @@ +/* + * Copyright (c) 2003-2005 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 + */ + +/** @file + * Definition of the MSHRQueue. + */ + +#include "mem/cache/miss/mshr_queue.hh" +#include "sim/eventq.hh" + +using namespace std; + +MSHRQueue::MSHRQueue(int num_mshrs, int reserve) + : numMSHRs(num_mshrs + reserve - 1), numReserve(reserve) +{ + allocated = 0; + inServiceMSHRs = 0; + allocatedTargets = 0; + registers = new MSHR[numMSHRs]; + for (int i = 0; i < numMSHRs; ++i) { + freeList.push_back(®isters[i]); + } +} + +MSHRQueue::~MSHRQueue() +{ + delete [] registers; +} + +MSHR* +MSHRQueue::findMatch(Addr addr, int asid) const +{ + MSHR::ConstIterator i = allocatedList.begin(); + MSHR::ConstIterator end = allocatedList.end(); + for (; i != end; ++i) { + MSHR *mshr = *i; + if (mshr->addr == addr) { + return mshr; + } + } + return NULL; +} + +bool +MSHRQueue::findMatches(Addr addr, int asid, vector<MSHR*>& matches) const +{ + // Need an empty vector + assert(matches.empty()); + bool retval = false; + MSHR::ConstIterator i = allocatedList.begin(); + MSHR::ConstIterator end = allocatedList.end(); + for (; i != end; ++i) { + MSHR *mshr = *i; + if (mshr->addr == addr) { + retval = true; + matches.push_back(mshr); + } + } + return retval; + +} + +MSHR* +MSHRQueue::findPending(Packet * &pkt) const +{ + MSHR::ConstIterator i = pendingList.begin(); + MSHR::ConstIterator end = pendingList.end(); + for (; i != end; ++i) { + MSHR *mshr = *i; + if (mshr->addr < pkt->getAddr()) { + if (mshr->addr + mshr->pkt->getSize() > pkt->getAddr()) { + return mshr; + } + } else { + if (pkt->getAddr() + pkt->getSize() > mshr->addr) { + return mshr; + } + } + + //need to check destination address for copies. + //TEMP NOT DOING COPIES +#if 0 + if (mshr->pkt->cmd == Copy) { + Addr dest = mshr->pkt->dest; + if (dest < pkt->addr) { + if (dest + mshr->pkt->size > pkt->addr) { + return mshr; + } + } else { + if (pkt->addr + pkt->size > dest) { + return mshr; + } + } + } +#endif + } + return NULL; +} + +MSHR* +MSHRQueue::allocate(Packet * &pkt, int size) +{ + Addr aligned_addr = pkt->getAddr() & ~((Addr)size - 1); + MSHR *mshr = freeList.front(); + assert(mshr->getNumTargets() == 0); + freeList.pop_front(); + + if (!pkt->needsResponse()) { + mshr->allocateAsBuffer(pkt); + } else { + assert(size !=0); + mshr->allocate(pkt->cmd, aligned_addr, pkt->req->getAsid(), size, pkt); + allocatedTargets += 1; + } + mshr->allocIter = allocatedList.insert(allocatedList.end(), mshr); + mshr->readyIter = pendingList.insert(pendingList.end(), mshr); + + allocated += 1; + return mshr; +} + +MSHR* +MSHRQueue::allocateFetch(Addr addr, int asid, int size, Packet * &target) +{ + MSHR *mshr = freeList.front(); + assert(mshr->getNumTargets() == 0); + freeList.pop_front(); + mshr->allocate(Packet::ReadReq, addr, asid, size, target); + mshr->allocIter = allocatedList.insert(allocatedList.end(), mshr); + mshr->readyIter = pendingList.insert(pendingList.end(), mshr); + + allocated += 1; + return mshr; +} + +MSHR* +MSHRQueue::allocateTargetList(Addr addr, int asid, int size) +{ + MSHR *mshr = freeList.front(); + assert(mshr->getNumTargets() == 0); + freeList.pop_front(); + Packet * dummy; + mshr->allocate(Packet::ReadReq, addr, asid, size, dummy); + mshr->allocIter = allocatedList.insert(allocatedList.end(), mshr); + mshr->inService = true; + ++inServiceMSHRs; + ++allocated; + return mshr; +} + + +void +MSHRQueue::deallocate(MSHR* mshr) +{ + deallocateOne(mshr); +} + +MSHR::Iterator +MSHRQueue::deallocateOne(MSHR* mshr) +{ + MSHR::Iterator retval = allocatedList.erase(mshr->allocIter); + freeList.push_front(mshr); + allocated--; + allocatedTargets -= mshr->getNumTargets(); + if (mshr->inService) { + inServiceMSHRs--; + } else { + pendingList.erase(mshr->readyIter); + } + mshr->deallocate(); + return retval; +} + +void +MSHRQueue::moveToFront(MSHR *mshr) +{ + if (!mshr->inService) { + assert(mshr == *(mshr->readyIter)); + pendingList.erase(mshr->readyIter); + mshr->readyIter = pendingList.insert(pendingList.begin(), mshr); + } +} + +void +MSHRQueue::markInService(MSHR* mshr) +{ + //assert(mshr == pendingList.front()); + if (!mshr->pkt->needsResponse()) { + assert(mshr->getNumTargets() == 0); + deallocate(mshr); + return; + } + mshr->inService = true; + pendingList.erase(mshr->readyIter); + mshr->readyIter = NULL; + inServiceMSHRs += 1; + //pendingList.pop_front(); +} + +void +MSHRQueue::markPending(MSHR* mshr, Packet::Command cmd) +{ + assert(mshr->readyIter == NULL); + mshr->pkt->cmd = cmd; + mshr->pkt->flags &= ~SATISFIED; + mshr->inService = false; + --inServiceMSHRs; + /** + * @ todo might want to add rerequests to front of pending list for + * performance. + */ + mshr->readyIter = pendingList.insert(pendingList.end(), mshr); +} + +void +MSHRQueue::squash(int threadNum) +{ + MSHR::Iterator i = allocatedList.begin(); + MSHR::Iterator end = allocatedList.end(); + for (; i != end;) { + MSHR *mshr = *i; + if (mshr->threadNum == threadNum) { + while (mshr->hasTargets()) { + Packet * target = mshr->getTarget(); + mshr->popTarget(); + + assert(target->req->getThreadNum() == threadNum); + target = NULL; + } + assert(!mshr->hasTargets()); + assert(mshr->ntargets==0); + if (!mshr->inService) { + i = deallocateOne(mshr); + } else { + //mshr->pkt->flags &= ~CACHE_LINE_FILL; + ++i; + } + } else { + ++i; + } + } +} diff --git a/src/mem/cache/miss/mshr_queue.hh b/src/mem/cache/miss/mshr_queue.hh new file mode 100644 index 000000000..a67f1b9a6 --- /dev/null +++ b/src/mem/cache/miss/mshr_queue.hh @@ -0,0 +1,239 @@ +/* + * Copyright (c) 2003-2005 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 + */ + +/** @file + * Declaration of a structure to manage MSHRs. + */ + +#ifndef __MSHR_QUEUE_HH__ +#define __MSHR_QUEUE_HH__ + +#include <vector> +#include "mem/cache/miss/mshr.hh" + +/** + * A Class for maintaining a list of pending and allocated memory requests. + */ +class MSHRQueue { + private: + /** MSHR storage. */ + MSHR* registers; + /** Holds pointers to all allocated MSHRs. */ + MSHR::List allocatedList; + /** Holds pointers to MSHRs that haven't been sent to the bus. */ + MSHR::List pendingList; + /** Holds non allocated MSHRs. */ + MSHR::List freeList; + + // Parameters + /** + * The total number of MSHRs in this queue. This number is set as the + * number of MSHRs requested plus (numReserve - 1). This allows for + * the same number of effective MSHRs while still maintaining the reserve. + */ + const int numMSHRs; + + /** + * The number of MSHRs to hold in reserve. This is needed because copy + * operations can allocate upto 4 MSHRs at one time. + */ + const int numReserve; + + public: + /** The number of allocated MSHRs. */ + int allocated; + /** The number of MSHRs that have been forwarded to the bus. */ + int inServiceMSHRs; + /** The number of targets waiting for response. */ + int allocatedTargets; + + /** + * Create a queue with a given number of MSHRs. + * @param num_mshrs The number of MSHRs in this queue. + * @param reserve The minimum number of MSHRs needed to satisfy any access. + */ + MSHRQueue(int num_mshrs, int reserve = 1); + + /** Destructor */ + ~MSHRQueue(); + + /** + * Find the first MSHR that matches the provide address and asid. + * @param addr The address to find. + * @param asid The address space id. + * @return Pointer to the matching MSHR, null if not found. + */ + MSHR* findMatch(Addr addr, int asid) const; + + /** + * Find and return all the matching MSHRs in the provided vector. + * @param addr The address to find. + * @param asid The address space ID. + * @param matches The vector to return pointers to the matching MSHRs. + * @return True if any matches are found, false otherwise. + * @todo Typedef the vector?? + */ + bool findMatches(Addr addr, int asid, std::vector<MSHR*>& matches) const; + + /** + * Find any pending requests that overlap the given request. + * @param req The request to find. + * @return A pointer to the earliest matching MSHR. + */ + MSHR* findPending(Packet * &pkt) const; + + /** + * Allocates a new MSHR for the request and size. This places the request + * as the first target in the MSHR. + * @param req The request to handle. + * @param size The number in bytes to fetch from memory. + * @return The a pointer to the MSHR allocated. + * + * @pre There are free MSHRs. + */ + MSHR* allocate(Packet * &pkt, int size = 0); + + /** + * Allocate a read request for the given address, and places the given + * target on the target list. + * @param addr The address to fetch. + * @param asid The address space for the fetch. + * @param size The number of bytes to request. + * @param target The first target for the request. + * @return Pointer to the new MSHR. + */ + MSHR* allocateFetch(Addr addr, int asid, int size, Packet * &target); + + /** + * Allocate a target list for the given address. + * @param addr The address to fetch. + * @param asid The address space for the fetch. + * @param size The number of bytes to request. + * @return Pointer to the new MSHR. + */ + MSHR* allocateTargetList(Addr addr, int asid, int size); + + /** + * Removes the given MSHR from the queue. This places the MSHR on the + * free list. + * @param mshr + */ + void deallocate(MSHR* mshr); + + /** + * Allocates a target to the given MSHR. Used to keep track of the number + * of outstanding targets. + * @param mshr The MSHR to allocate the target to. + * @param req The target request. + */ + void allocateTarget(MSHR* mshr, Packet * &pkt) + { + mshr->allocateTarget(pkt); + allocatedTargets += 1; + } + + /** + * Remove a MSHR from the queue. Returns an iterator into the allocatedList + * for faster squash implementation. + * @param mshr The MSHR to remove. + * @return An iterator to the next entry in the allocatedList. + */ + MSHR::Iterator deallocateOne(MSHR* mshr); + + /** + * Moves the MSHR to the front of the pending list if it is not in service. + * @param mshr The mshr to move. + */ + void moveToFront(MSHR *mshr); + + /** + * Mark the given MSHR as in service. This removes the MSHR from the + * pendingList. Deallocates the MSHR if it does not expect a response. + * @param mshr The MSHR to mark in service. + */ + void markInService(MSHR* mshr); + + /** + * Mark an in service mshr as pending, used to resend a request. + * @param mshr The MSHR to resend. + * @param cmd The command to resend. + */ + void markPending(MSHR* mshr, Packet::Command cmd); + + /** + * Squash outstanding requests with the given thread number. If a request + * is in service, just squashes the targets. + * @param req->getThreadNum()ber The thread to squash. + */ + void squash(int threadNum); + + /** + * Returns true if the pending list is not empty. + * @return True if there are outstanding requests. + */ + bool havePending() const + { + return !pendingList.empty(); + } + + /** + * Returns true if there are no free MSHRs. + * @return True if this queue is full. + */ + bool isFull() const + { + return (allocated > numMSHRs - numReserve); + } + + /** + * Returns the request at the head of the pendingList. + * @return The next request to service. + */ + Packet * getReq() const + { + if (pendingList.empty()) { + return NULL; + } + MSHR* mshr = pendingList.front(); + return mshr->pkt; + } + + /** + * Returns the number of outstanding targets. + * @return the number of allocated targets. + */ + int getAllocatedTargets() const + { + return allocatedTargets; + } + +}; + +#endif //__MSHR_QUEUE_HH__ |