| /* |
| * Copyright (c) 2012-2013, 2015-2016, 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) 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 |
| * Andreas Sandberg |
| * Andreas Hansson |
| */ |
| |
| /** @file |
| * Declaration of a high-level queue structure |
| */ |
| |
| #ifndef __MEM_CACHE_QUEUE_HH__ |
| #define __MEM_CACHE_QUEUE_HH__ |
| |
| #include <cassert> |
| #include <string> |
| |
| #include "base/logging.hh" |
| #include "base/trace.hh" |
| #include "base/types.hh" |
| #include "debug/Drain.hh" |
| #include "mem/cache/queue_entry.hh" |
| #include "mem/packet.hh" |
| #include "sim/core.hh" |
| #include "sim/drain.hh" |
| |
| /** |
| * A high-level queue interface, to be used by both the MSHR queue and |
| * the write buffer. |
| */ |
| template<class Entry> |
| class Queue : public Drainable |
| { |
| protected: |
| /** Local label (for functional print requests) */ |
| const std::string label; |
| |
| /** |
| * The total number of entries in this queue. This number is set |
| * as the number of entries requested plus any reserve. This |
| * allows for the same number of effective entries while still |
| * maintaining an overflow reserve. |
| */ |
| const int numEntries; |
| |
| /** |
| * The number of entries to hold as a temporary overflow |
| * space. This is used to allow temporary overflow of the number |
| * of entries as we only check the full condition under certain |
| * conditions. |
| */ |
| const int numReserve; |
| |
| /** Actual storage. */ |
| std::vector<Entry> entries; |
| /** Holds pointers to all allocated entries. */ |
| typename Entry::List allocatedList; |
| /** Holds pointers to entries that haven't been sent downstream. */ |
| typename Entry::List readyList; |
| /** Holds non allocated entries. */ |
| typename Entry::List freeList; |
| |
| typename Entry::Iterator addToReadyList(Entry* entry) |
| { |
| if (readyList.empty() || |
| readyList.back()->readyTime <= entry->readyTime) { |
| return readyList.insert(readyList.end(), entry); |
| } |
| |
| for (auto i = readyList.begin(); i != readyList.end(); ++i) { |
| if ((*i)->readyTime > entry->readyTime) { |
| return readyList.insert(i, entry); |
| } |
| } |
| panic("Failed to add to ready list."); |
| } |
| |
| /** The number of entries that are in service. */ |
| int _numInService; |
| |
| /** The number of currently allocated entries. */ |
| int allocated; |
| |
| public: |
| |
| /** |
| * Create a queue with a given number of entries. |
| * |
| * @param num_entries The number of entries in this queue. |
| * @param reserve The extra overflow entries needed. |
| */ |
| Queue(const std::string &_label, int num_entries, int reserve) : |
| label(_label), numEntries(num_entries + reserve), |
| numReserve(reserve), entries(numEntries), _numInService(0), |
| allocated(0) |
| { |
| for (int i = 0; i < numEntries; ++i) { |
| freeList.push_back(&entries[i]); |
| } |
| } |
| |
| bool isEmpty() const |
| { |
| return allocated == 0; |
| } |
| |
| bool isFull() const |
| { |
| return (allocated >= numEntries - numReserve); |
| } |
| |
| int numInService() const |
| { |
| return _numInService; |
| } |
| |
| /** |
| * 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, |
| bool ignore_uncacheable = true) const |
| { |
| for (const auto& entry : allocatedList) { |
| // we ignore any entries allocated for uncacheable |
| // accesses and simply ignore them when matching, in the |
| // cache we never check for matches when adding new |
| // uncacheable entries, and we do not want normal |
| // cacheable accesses being added to an WriteQueueEntry |
| // serving an uncacheable access |
| if (!(ignore_uncacheable && entry->isUncacheable()) && |
| entry->blkAddr == blk_addr && entry->isSecure == is_secure) { |
| return entry; |
| } |
| } |
| return nullptr; |
| } |
| |
| bool trySatisfyFunctional(PacketPtr pkt, Addr blk_addr) |
| { |
| pkt->pushLabel(label); |
| for (const auto& entry : allocatedList) { |
| if (entry->blkAddr == blk_addr && entry->trySatisfyFunctional(pkt)) { |
| pkt->popLabel(); |
| return true; |
| } |
| } |
| pkt->popLabel(); |
| return false; |
| } |
| |
| /** |
| * Find any pending requests that overlap the given request. |
| * @param blk_addr Block address. |
| * @param is_secure True if the target memory space is secure. |
| * @return A pointer to the earliest matching WriteQueueEntry. |
| */ |
| Entry* findPending(Addr blk_addr, bool is_secure) const |
| { |
| for (const auto& entry : readyList) { |
| if (entry->blkAddr == blk_addr && entry->isSecure == is_secure) { |
| return entry; |
| } |
| } |
| return nullptr; |
| } |
| |
| /** |
| * Returns the WriteQueueEntry at the head of the readyList. |
| * @return The next request to service. |
| */ |
| Entry* getNext() const |
| { |
| if (readyList.empty() || readyList.front()->readyTime > curTick()) { |
| return nullptr; |
| } |
| return readyList.front(); |
| } |
| |
| Tick nextReadyTime() const |
| { |
| return readyList.empty() ? MaxTick : readyList.front()->readyTime; |
| } |
| |
| /** |
| * Removes the given entry from the queue. This places the entry |
| * on the free list. |
| * |
| * @param entry |
| */ |
| void deallocate(Entry *entry) |
| { |
| allocatedList.erase(entry->allocIter); |
| freeList.push_front(entry); |
| allocated--; |
| if (entry->inService) { |
| _numInService--; |
| } else { |
| readyList.erase(entry->readyIter); |
| } |
| entry->deallocate(); |
| if (drainState() == DrainState::Draining && allocated == 0) { |
| // Notify the drain manager that we have completed |
| // draining if there are no other outstanding requests in |
| // this queue. |
| DPRINTF(Drain, "Queue now empty, signalling drained\n"); |
| signalDrainDone(); |
| } |
| } |
| |
| DrainState drain() override |
| { |
| return allocated == 0 ? DrainState::Drained : DrainState::Draining; |
| } |
| }; |
| |
| #endif //__MEM_CACHE_QUEUE_HH__ |
