queue.hh revision 12726:850e9965525b
1/* 2 * Copyright (c) 2012-2013, 2015-2016, 2018 ARM Limited 3 * All rights reserved. 4 * 5 * The license below extends only to copyright in the software and shall 6 * not be construed as granting a license to any other intellectual 7 * property including but not limited to intellectual property relating 8 * to a hardware implementation of the functionality of the software 9 * licensed hereunder. You may use the software subject to the license 10 * terms below provided that you ensure that this notice is replicated 11 * unmodified and in its entirety in all distributions of the software, 12 * modified or unmodified, in source code or in binary form. 13 * 14 * Copyright (c) 2003-2005 The Regents of The University of Michigan 15 * All rights reserved. 16 * 17 * Redistribution and use in source and binary forms, with or without 18 * modification, are permitted provided that the following conditions are 19 * met: redistributions of source code must retain the above copyright 20 * notice, this list of conditions and the following disclaimer; 21 * redistributions in binary form must reproduce the above copyright 22 * notice, this list of conditions and the following disclaimer in the 23 * documentation and/or other materials provided with the distribution; 24 * neither the name of the copyright holders nor the names of its 25 * contributors may be used to endorse or promote products derived from 26 * this software without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 39 * 40 * Authors: Erik Hallnor 41 * Andreas Sandberg 42 * Andreas Hansson 43 */ 44 45/** @file 46 * Declaration of a high-level queue structure 47 */ 48 49#ifndef __MEM_CACHE_QUEUE_HH__ 50#define __MEM_CACHE_QUEUE_HH__ 51 52#include <cassert> 53 54#include "base/trace.hh" 55#include "debug/Drain.hh" 56#include "mem/cache/queue_entry.hh" 57#include "sim/drain.hh" 58 59/** 60 * A high-level queue interface, to be used by both the MSHR queue and 61 * the write buffer. 62 */ 63template<class Entry> 64class Queue : public Drainable 65{ 66 protected: 67 /** Local label (for functional print requests) */ 68 const std::string label; 69 70 /** 71 * The total number of entries in this queue. This number is set 72 * as the number of entries requested plus any reserve. This 73 * allows for the same number of effective entries while still 74 * maintaining an overflow reserve. 75 */ 76 const int numEntries; 77 78 /** 79 * The number of entries to hold as a temporary overflow 80 * space. This is used to allow temporary overflow of the number 81 * of entries as we only check the full condition under certain 82 * conditions. 83 */ 84 const int numReserve; 85 86 /** Actual storage. */ 87 std::vector<Entry> entries; 88 /** Holds pointers to all allocated entries. */ 89 typename Entry::List allocatedList; 90 /** Holds pointers to entries that haven't been sent downstream. */ 91 typename Entry::List readyList; 92 /** Holds non allocated entries. */ 93 typename Entry::List freeList; 94 95 typename Entry::Iterator addToReadyList(Entry* entry) 96 { 97 if (readyList.empty() || 98 readyList.back()->readyTime <= entry->readyTime) { 99 return readyList.insert(readyList.end(), entry); 100 } 101 102 for (auto i = readyList.begin(); i != readyList.end(); ++i) { 103 if ((*i)->readyTime > entry->readyTime) { 104 return readyList.insert(i, entry); 105 } 106 } 107 assert(false); 108 return readyList.end(); // keep stupid compilers happy 109 } 110 111 /** The number of entries that are in service. */ 112 int _numInService; 113 114 /** The number of currently allocated entries. */ 115 int allocated; 116 117 public: 118 119 /** 120 * Create a queue with a given number of entries. 121 * 122 * @param num_entries The number of entries in this queue. 123 * @param reserve The extra overflow entries needed. 124 */ 125 Queue(const std::string &_label, int num_entries, int reserve) : 126 label(_label), numEntries(num_entries + reserve), 127 numReserve(reserve), entries(numEntries), _numInService(0), 128 allocated(0) 129 { 130 for (int i = 0; i < numEntries; ++i) { 131 freeList.push_back(&entries[i]); 132 } 133 } 134 135 bool isEmpty() const 136 { 137 return allocated == 0; 138 } 139 140 bool isFull() const 141 { 142 return (allocated >= numEntries - numReserve); 143 } 144 145 int numInService() const 146 { 147 return _numInService; 148 } 149 150 /** 151 * Find the first entry that matches the provided address. 152 * 153 * @param blk_addr The block address to find. 154 * @param is_secure True if the target memory space is secure. 155 * @param ignore_uncacheable Should uncacheables be ignored or not 156 * @return Pointer to the matching WriteQueueEntry, null if not found. 157 */ 158 Entry* findMatch(Addr blk_addr, bool is_secure, 159 bool ignore_uncacheable = true) const 160 { 161 for (const auto& entry : allocatedList) { 162 // we ignore any entries allocated for uncacheable 163 // accesses and simply ignore them when matching, in the 164 // cache we never check for matches when adding new 165 // uncacheable entries, and we do not want normal 166 // cacheable accesses being added to an WriteQueueEntry 167 // serving an uncacheable access 168 if (!(ignore_uncacheable && entry->isUncacheable()) && 169 entry->blkAddr == blk_addr && entry->isSecure == is_secure) { 170 return entry; 171 } 172 } 173 return nullptr; 174 } 175 176 bool checkFunctional(PacketPtr pkt, Addr blk_addr) 177 { 178 pkt->pushLabel(label); 179 for (const auto& entry : allocatedList) { 180 if (entry->blkAddr == blk_addr && entry->checkFunctional(pkt)) { 181 pkt->popLabel(); 182 return true; 183 } 184 } 185 pkt->popLabel(); 186 return false; 187 } 188 189 /** 190 * Find any pending requests that overlap the given request. 191 * @param blk_addr Block address. 192 * @param is_secure True if the target memory space is secure. 193 * @return A pointer to the earliest matching WriteQueueEntry. 194 */ 195 Entry* findPending(Addr blk_addr, bool is_secure) const 196 { 197 for (const auto& entry : readyList) { 198 if (entry->blkAddr == blk_addr && entry->isSecure == is_secure) { 199 return entry; 200 } 201 } 202 return nullptr; 203 } 204 205 /** 206 * Returns the WriteQueueEntry at the head of the readyList. 207 * @return The next request to service. 208 */ 209 Entry* getNext() const 210 { 211 if (readyList.empty() || readyList.front()->readyTime > curTick()) { 212 return nullptr; 213 } 214 return readyList.front(); 215 } 216 217 Tick nextReadyTime() const 218 { 219 return readyList.empty() ? MaxTick : readyList.front()->readyTime; 220 } 221 222 /** 223 * Removes the given entry from the queue. This places the entry 224 * on the free list. 225 * 226 * @param entry 227 */ 228 void deallocate(Entry *entry) 229 { 230 allocatedList.erase(entry->allocIter); 231 freeList.push_front(entry); 232 allocated--; 233 if (entry->inService) { 234 _numInService--; 235 } else { 236 readyList.erase(entry->readyIter); 237 } 238 entry->deallocate(); 239 if (drainState() == DrainState::Draining && allocated == 0) { 240 // Notify the drain manager that we have completed 241 // draining if there are no other outstanding requests in 242 // this queue. 243 DPRINTF(Drain, "Queue now empty, signalling drained\n"); 244 signalDrainDone(); 245 } 246 } 247 248 DrainState drain() override 249 { 250 return allocated == 0 ? DrainState::Drained : DrainState::Draining; 251 } 252}; 253 254#endif //__MEM_CACHE_QUEUE_HH__ 255