1/* 2 * Copyright (c) 2010-2016 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) 2013 Amin Farmahini-Farahani 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: Andreas Hansson 41 * Ani Udipi 42 * Neha Agarwal 43 * Omar Naji
| 1/* 2 * Copyright (c) 2010-2016 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) 2013 Amin Farmahini-Farahani 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: Andreas Hansson 41 * Ani Udipi 42 * Neha Agarwal 43 * Omar Naji
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| 44 * Wendy Elsasser
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44 */ 45 46#include "base/bitfield.hh" 47#include "base/trace.hh" 48#include "debug/DRAM.hh" 49#include "debug/DRAMPower.hh" 50#include "debug/DRAMState.hh" 51#include "debug/Drain.hh" 52#include "mem/dram_ctrl.hh" 53#include "sim/system.hh" 54 55using namespace std; 56using namespace Data; 57 58DRAMCtrl::DRAMCtrl(const DRAMCtrlParams* p) : 59 AbstractMemory(p), 60 port(name() + ".port", *this), isTimingMode(false), 61 retryRdReq(false), retryWrReq(false), 62 busState(READ),
| 45 */ 46 47#include "base/bitfield.hh" 48#include "base/trace.hh" 49#include "debug/DRAM.hh" 50#include "debug/DRAMPower.hh" 51#include "debug/DRAMState.hh" 52#include "debug/Drain.hh" 53#include "mem/dram_ctrl.hh" 54#include "sim/system.hh" 55 56using namespace std; 57using namespace Data; 58 59DRAMCtrl::DRAMCtrl(const DRAMCtrlParams* p) : 60 AbstractMemory(p), 61 port(name() + ".port", *this), isTimingMode(false), 62 retryRdReq(false), retryWrReq(false), 63 busState(READ),
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| 64 busStateNext(READ),
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63 nextReqEvent(this), respondEvent(this), 64 deviceSize(p->device_size), 65 deviceBusWidth(p->device_bus_width), burstLength(p->burst_length), 66 deviceRowBufferSize(p->device_rowbuffer_size), 67 devicesPerRank(p->devices_per_rank), 68 burstSize((devicesPerRank * burstLength * deviceBusWidth) / 8), 69 rowBufferSize(devicesPerRank * deviceRowBufferSize), 70 columnsPerRowBuffer(rowBufferSize / burstSize), 71 columnsPerStripe(range.interleaved() ? range.granularity() / burstSize : 1), 72 ranksPerChannel(p->ranks_per_channel), 73 bankGroupsPerRank(p->bank_groups_per_rank), 74 bankGroupArch(p->bank_groups_per_rank > 0), 75 banksPerRank(p->banks_per_rank), channels(p->channels), rowsPerBank(0), 76 readBufferSize(p->read_buffer_size), 77 writeBufferSize(p->write_buffer_size), 78 writeHighThreshold(writeBufferSize * p->write_high_thresh_perc / 100.0), 79 writeLowThreshold(writeBufferSize * p->write_low_thresh_perc / 100.0), 80 minWritesPerSwitch(p->min_writes_per_switch), 81 writesThisTime(0), readsThisTime(0), 82 tCK(p->tCK), tWTR(p->tWTR), tRTW(p->tRTW), tCS(p->tCS), tBURST(p->tBURST), 83 tCCD_L(p->tCCD_L), tRCD(p->tRCD), tCL(p->tCL), tRP(p->tRP), tRAS(p->tRAS), 84 tWR(p->tWR), tRTP(p->tRTP), tRFC(p->tRFC), tREFI(p->tREFI), tRRD(p->tRRD), 85 tRRD_L(p->tRRD_L), tXAW(p->tXAW), tXP(p->tXP), tXS(p->tXS), 86 activationLimit(p->activation_limit), 87 memSchedPolicy(p->mem_sched_policy), addrMapping(p->addr_mapping), 88 pageMgmt(p->page_policy), 89 maxAccessesPerRow(p->max_accesses_per_row), 90 frontendLatency(p->static_frontend_latency), 91 backendLatency(p->static_backend_latency), 92 busBusyUntil(0), prevArrival(0), 93 nextReqTime(0), activeRank(0), timeStampOffset(0) 94{ 95 // sanity check the ranks since we rely on bit slicing for the 96 // address decoding 97 fatal_if(!isPowerOf2(ranksPerChannel), "DRAM rank count of %d is not " 98 "allowed, must be a power of two\n", ranksPerChannel); 99 100 fatal_if(!isPowerOf2(burstSize), "DRAM burst size %d is not allowed, " 101 "must be a power of two\n", burstSize); 102 103 for (int i = 0; i < ranksPerChannel; i++) { 104 Rank* rank = new Rank(*this, p); 105 ranks.push_back(rank); 106 107 rank->actTicks.resize(activationLimit, 0); 108 rank->banks.resize(banksPerRank); 109 rank->rank = i; 110 111 for (int b = 0; b < banksPerRank; b++) { 112 rank->banks[b].bank = b; 113 // GDDR addressing of banks to BG is linear. 114 // Here we assume that all DRAM generations address bank groups as 115 // follows: 116 if (bankGroupArch) { 117 // Simply assign lower bits to bank group in order to 118 // rotate across bank groups as banks are incremented 119 // e.g. with 4 banks per bank group and 16 banks total: 120 // banks 0,4,8,12 are in bank group 0 121 // banks 1,5,9,13 are in bank group 1 122 // banks 2,6,10,14 are in bank group 2 123 // banks 3,7,11,15 are in bank group 3 124 rank->banks[b].bankgr = b % bankGroupsPerRank; 125 } else { 126 // No bank groups; simply assign to bank number 127 rank->banks[b].bankgr = b; 128 } 129 } 130 } 131 132 // perform a basic check of the write thresholds 133 if (p->write_low_thresh_perc >= p->write_high_thresh_perc) 134 fatal("Write buffer low threshold %d must be smaller than the " 135 "high threshold %d\n", p->write_low_thresh_perc, 136 p->write_high_thresh_perc); 137 138 // determine the rows per bank by looking at the total capacity 139 uint64_t capacity = ULL(1) << ceilLog2(AbstractMemory::size()); 140 141 // determine the dram actual capacity from the DRAM config in Mbytes 142 uint64_t deviceCapacity = deviceSize / (1024 * 1024) * devicesPerRank * 143 ranksPerChannel; 144 145 // if actual DRAM size does not match memory capacity in system warn! 146 if (deviceCapacity != capacity / (1024 * 1024)) 147 warn("DRAM device capacity (%d Mbytes) does not match the " 148 "address range assigned (%d Mbytes)\n", deviceCapacity, 149 capacity / (1024 * 1024)); 150 151 DPRINTF(DRAM, "Memory capacity %lld (%lld) bytes\n", capacity, 152 AbstractMemory::size()); 153 154 DPRINTF(DRAM, "Row buffer size %d bytes with %d columns per row buffer\n", 155 rowBufferSize, columnsPerRowBuffer); 156 157 rowsPerBank = capacity / (rowBufferSize * banksPerRank * ranksPerChannel); 158 159 // some basic sanity checks 160 if (tREFI <= tRP || tREFI <= tRFC) { 161 fatal("tREFI (%d) must be larger than tRP (%d) and tRFC (%d)\n", 162 tREFI, tRP, tRFC); 163 } 164 165 // basic bank group architecture checks -> 166 if (bankGroupArch) { 167 // must have at least one bank per bank group 168 if (bankGroupsPerRank > banksPerRank) { 169 fatal("banks per rank (%d) must be equal to or larger than " 170 "banks groups per rank (%d)\n", 171 banksPerRank, bankGroupsPerRank); 172 } 173 // must have same number of banks in each bank group 174 if ((banksPerRank % bankGroupsPerRank) != 0) { 175 fatal("Banks per rank (%d) must be evenly divisible by bank groups " 176 "per rank (%d) for equal banks per bank group\n", 177 banksPerRank, bankGroupsPerRank); 178 } 179 // tCCD_L should be greater than minimal, back-to-back burst delay 180 if (tCCD_L <= tBURST) { 181 fatal("tCCD_L (%d) should be larger than tBURST (%d) when " 182 "bank groups per rank (%d) is greater than 1\n", 183 tCCD_L, tBURST, bankGroupsPerRank); 184 } 185 // tRRD_L is greater than minimal, same bank group ACT-to-ACT delay 186 // some datasheets might specify it equal to tRRD 187 if (tRRD_L < tRRD) { 188 fatal("tRRD_L (%d) should be larger than tRRD (%d) when " 189 "bank groups per rank (%d) is greater than 1\n", 190 tRRD_L, tRRD, bankGroupsPerRank); 191 } 192 } 193 194} 195 196void 197DRAMCtrl::init() 198{ 199 AbstractMemory::init(); 200 201 if (!port.isConnected()) { 202 fatal("DRAMCtrl %s is unconnected!\n", name()); 203 } else { 204 port.sendRangeChange(); 205 } 206 207 // a bit of sanity checks on the interleaving, save it for here to 208 // ensure that the system pointer is initialised 209 if (range.interleaved()) { 210 if (channels != range.stripes()) 211 fatal("%s has %d interleaved address stripes but %d channel(s)\n", 212 name(), range.stripes(), channels); 213 214 if (addrMapping == Enums::RoRaBaChCo) { 215 if (rowBufferSize != range.granularity()) { 216 fatal("Channel interleaving of %s doesn't match RoRaBaChCo " 217 "address map\n", name()); 218 } 219 } else if (addrMapping == Enums::RoRaBaCoCh || 220 addrMapping == Enums::RoCoRaBaCh) { 221 // for the interleavings with channel bits in the bottom, 222 // if the system uses a channel striping granularity that 223 // is larger than the DRAM burst size, then map the 224 // sequential accesses within a stripe to a number of 225 // columns in the DRAM, effectively placing some of the 226 // lower-order column bits as the least-significant bits 227 // of the address (above the ones denoting the burst size) 228 assert(columnsPerStripe >= 1); 229 230 // channel striping has to be done at a granularity that 231 // is equal or larger to a cache line 232 if (system()->cacheLineSize() > range.granularity()) { 233 fatal("Channel interleaving of %s must be at least as large " 234 "as the cache line size\n", name()); 235 } 236 237 // ...and equal or smaller than the row-buffer size 238 if (rowBufferSize < range.granularity()) { 239 fatal("Channel interleaving of %s must be at most as large " 240 "as the row-buffer size\n", name()); 241 } 242 // this is essentially the check above, so just to be sure 243 assert(columnsPerStripe <= columnsPerRowBuffer); 244 } 245 } 246} 247 248void 249DRAMCtrl::startup() 250{ 251 // remember the memory system mode of operation 252 isTimingMode = system()->isTimingMode(); 253 254 if (isTimingMode) { 255 // timestamp offset should be in clock cycles for DRAMPower 256 timeStampOffset = divCeil(curTick(), tCK); 257 258 // update the start tick for the precharge accounting to the 259 // current tick 260 for (auto r : ranks) { 261 r->startup(curTick() + tREFI - tRP); 262 } 263 264 // shift the bus busy time sufficiently far ahead that we never 265 // have to worry about negative values when computing the time for 266 // the next request, this will add an insignificant bubble at the 267 // start of simulation 268 busBusyUntil = curTick() + tRP + tRCD + tCL; 269 } 270} 271 272Tick 273DRAMCtrl::recvAtomic(PacketPtr pkt) 274{ 275 DPRINTF(DRAM, "recvAtomic: %s 0x%x\n", pkt->cmdString(), pkt->getAddr()); 276 277 panic_if(pkt->cacheResponding(), "Should not see packets where cache " 278 "is responding"); 279 280 // do the actual memory access and turn the packet into a response 281 access(pkt); 282 283 Tick latency = 0; 284 if (pkt->hasData()) { 285 // this value is not supposed to be accurate, just enough to 286 // keep things going, mimic a closed page 287 latency = tRP + tRCD + tCL; 288 } 289 return latency; 290} 291 292bool 293DRAMCtrl::readQueueFull(unsigned int neededEntries) const 294{ 295 DPRINTF(DRAM, "Read queue limit %d, current size %d, entries needed %d\n", 296 readBufferSize, readQueue.size() + respQueue.size(), 297 neededEntries); 298 299 return 300 (readQueue.size() + respQueue.size() + neededEntries) > readBufferSize; 301} 302 303bool 304DRAMCtrl::writeQueueFull(unsigned int neededEntries) const 305{ 306 DPRINTF(DRAM, "Write queue limit %d, current size %d, entries needed %d\n", 307 writeBufferSize, writeQueue.size(), neededEntries); 308 return (writeQueue.size() + neededEntries) > writeBufferSize; 309} 310 311DRAMCtrl::DRAMPacket* 312DRAMCtrl::decodeAddr(PacketPtr pkt, Addr dramPktAddr, unsigned size, 313 bool isRead) 314{ 315 // decode the address based on the address mapping scheme, with 316 // Ro, Ra, Co, Ba and Ch denoting row, rank, column, bank and 317 // channel, respectively 318 uint8_t rank; 319 uint8_t bank; 320 // use a 64-bit unsigned during the computations as the row is 321 // always the top bits, and check before creating the DRAMPacket 322 uint64_t row; 323 324 // truncate the address to a DRAM burst, which makes it unique to 325 // a specific column, row, bank, rank and channel 326 Addr addr = dramPktAddr / burstSize; 327 328 // we have removed the lowest order address bits that denote the 329 // position within the column 330 if (addrMapping == Enums::RoRaBaChCo) { 331 // the lowest order bits denote the column to ensure that 332 // sequential cache lines occupy the same row 333 addr = addr / columnsPerRowBuffer; 334 335 // take out the channel part of the address 336 addr = addr / channels; 337 338 // after the channel bits, get the bank bits to interleave 339 // over the banks 340 bank = addr % banksPerRank; 341 addr = addr / banksPerRank; 342 343 // after the bank, we get the rank bits which thus interleaves 344 // over the ranks 345 rank = addr % ranksPerChannel; 346 addr = addr / ranksPerChannel; 347 348 // lastly, get the row bits, no need to remove them from addr 349 row = addr % rowsPerBank; 350 } else if (addrMapping == Enums::RoRaBaCoCh) { 351 // take out the lower-order column bits 352 addr = addr / columnsPerStripe; 353 354 // take out the channel part of the address 355 addr = addr / channels; 356 357 // next, the higher-order column bites 358 addr = addr / (columnsPerRowBuffer / columnsPerStripe); 359 360 // after the column bits, we get the bank bits to interleave 361 // over the banks 362 bank = addr % banksPerRank; 363 addr = addr / banksPerRank; 364 365 // after the bank, we get the rank bits which thus interleaves 366 // over the ranks 367 rank = addr % ranksPerChannel; 368 addr = addr / ranksPerChannel; 369 370 // lastly, get the row bits, no need to remove them from addr 371 row = addr % rowsPerBank; 372 } else if (addrMapping == Enums::RoCoRaBaCh) { 373 // optimise for closed page mode and utilise maximum 374 // parallelism of the DRAM (at the cost of power) 375 376 // take out the lower-order column bits 377 addr = addr / columnsPerStripe; 378 379 // take out the channel part of the address, not that this has 380 // to match with how accesses are interleaved between the 381 // controllers in the address mapping 382 addr = addr / channels; 383 384 // start with the bank bits, as this provides the maximum 385 // opportunity for parallelism between requests 386 bank = addr % banksPerRank; 387 addr = addr / banksPerRank; 388 389 // next get the rank bits 390 rank = addr % ranksPerChannel; 391 addr = addr / ranksPerChannel; 392 393 // next, the higher-order column bites 394 addr = addr / (columnsPerRowBuffer / columnsPerStripe); 395 396 // lastly, get the row bits, no need to remove them from addr 397 row = addr % rowsPerBank; 398 } else 399 panic("Unknown address mapping policy chosen!"); 400 401 assert(rank < ranksPerChannel); 402 assert(bank < banksPerRank); 403 assert(row < rowsPerBank); 404 assert(row < Bank::NO_ROW); 405 406 DPRINTF(DRAM, "Address: %lld Rank %d Bank %d Row %d\n", 407 dramPktAddr, rank, bank, row); 408 409 // create the corresponding DRAM packet with the entry time and 410 // ready time set to the current tick, the latter will be updated 411 // later 412 uint16_t bank_id = banksPerRank * rank + bank; 413 return new DRAMPacket(pkt, isRead, rank, bank, row, bank_id, dramPktAddr, 414 size, ranks[rank]->banks[bank], *ranks[rank]); 415} 416 417void 418DRAMCtrl::addToReadQueue(PacketPtr pkt, unsigned int pktCount) 419{ 420 // only add to the read queue here. whenever the request is 421 // eventually done, set the readyTime, and call schedule() 422 assert(!pkt->isWrite()); 423 424 assert(pktCount != 0); 425 426 // if the request size is larger than burst size, the pkt is split into 427 // multiple DRAM packets 428 // Note if the pkt starting address is not aligened to burst size, the 429 // address of first DRAM packet is kept unaliged. Subsequent DRAM packets 430 // are aligned to burst size boundaries. This is to ensure we accurately 431 // check read packets against packets in write queue. 432 Addr addr = pkt->getAddr(); 433 unsigned pktsServicedByWrQ = 0; 434 BurstHelper* burst_helper = NULL; 435 for (int cnt = 0; cnt < pktCount; ++cnt) { 436 unsigned size = std::min((addr | (burstSize - 1)) + 1, 437 pkt->getAddr() + pkt->getSize()) - addr; 438 readPktSize[ceilLog2(size)]++; 439 readBursts++; 440 441 // First check write buffer to see if the data is already at 442 // the controller 443 bool foundInWrQ = false; 444 Addr burst_addr = burstAlign(addr); 445 // if the burst address is not present then there is no need 446 // looking any further 447 if (isInWriteQueue.find(burst_addr) != isInWriteQueue.end()) { 448 for (const auto& p : writeQueue) { 449 // check if the read is subsumed in the write queue 450 // packet we are looking at 451 if (p->addr <= addr && (addr + size) <= (p->addr + p->size)) { 452 foundInWrQ = true; 453 servicedByWrQ++; 454 pktsServicedByWrQ++; 455 DPRINTF(DRAM, "Read to addr %lld with size %d serviced by " 456 "write queue\n", addr, size); 457 bytesReadWrQ += burstSize; 458 break; 459 } 460 } 461 } 462 463 // If not found in the write q, make a DRAM packet and 464 // push it onto the read queue 465 if (!foundInWrQ) { 466 467 // Make the burst helper for split packets 468 if (pktCount > 1 && burst_helper == NULL) { 469 DPRINTF(DRAM, "Read to addr %lld translates to %d " 470 "dram requests\n", pkt->getAddr(), pktCount); 471 burst_helper = new BurstHelper(pktCount); 472 } 473 474 DRAMPacket* dram_pkt = decodeAddr(pkt, addr, size, true); 475 dram_pkt->burstHelper = burst_helper; 476 477 assert(!readQueueFull(1)); 478 rdQLenPdf[readQueue.size() + respQueue.size()]++; 479 480 DPRINTF(DRAM, "Adding to read queue\n"); 481 482 readQueue.push_back(dram_pkt); 483
| 65 nextReqEvent(this), respondEvent(this), 66 deviceSize(p->device_size), 67 deviceBusWidth(p->device_bus_width), burstLength(p->burst_length), 68 deviceRowBufferSize(p->device_rowbuffer_size), 69 devicesPerRank(p->devices_per_rank), 70 burstSize((devicesPerRank * burstLength * deviceBusWidth) / 8), 71 rowBufferSize(devicesPerRank * deviceRowBufferSize), 72 columnsPerRowBuffer(rowBufferSize / burstSize), 73 columnsPerStripe(range.interleaved() ? range.granularity() / burstSize : 1), 74 ranksPerChannel(p->ranks_per_channel), 75 bankGroupsPerRank(p->bank_groups_per_rank), 76 bankGroupArch(p->bank_groups_per_rank > 0), 77 banksPerRank(p->banks_per_rank), channels(p->channels), rowsPerBank(0), 78 readBufferSize(p->read_buffer_size), 79 writeBufferSize(p->write_buffer_size), 80 writeHighThreshold(writeBufferSize * p->write_high_thresh_perc / 100.0), 81 writeLowThreshold(writeBufferSize * p->write_low_thresh_perc / 100.0), 82 minWritesPerSwitch(p->min_writes_per_switch), 83 writesThisTime(0), readsThisTime(0), 84 tCK(p->tCK), tWTR(p->tWTR), tRTW(p->tRTW), tCS(p->tCS), tBURST(p->tBURST), 85 tCCD_L(p->tCCD_L), tRCD(p->tRCD), tCL(p->tCL), tRP(p->tRP), tRAS(p->tRAS), 86 tWR(p->tWR), tRTP(p->tRTP), tRFC(p->tRFC), tREFI(p->tREFI), tRRD(p->tRRD), 87 tRRD_L(p->tRRD_L), tXAW(p->tXAW), tXP(p->tXP), tXS(p->tXS), 88 activationLimit(p->activation_limit), 89 memSchedPolicy(p->mem_sched_policy), addrMapping(p->addr_mapping), 90 pageMgmt(p->page_policy), 91 maxAccessesPerRow(p->max_accesses_per_row), 92 frontendLatency(p->static_frontend_latency), 93 backendLatency(p->static_backend_latency), 94 busBusyUntil(0), prevArrival(0), 95 nextReqTime(0), activeRank(0), timeStampOffset(0) 96{ 97 // sanity check the ranks since we rely on bit slicing for the 98 // address decoding 99 fatal_if(!isPowerOf2(ranksPerChannel), "DRAM rank count of %d is not " 100 "allowed, must be a power of two\n", ranksPerChannel); 101 102 fatal_if(!isPowerOf2(burstSize), "DRAM burst size %d is not allowed, " 103 "must be a power of two\n", burstSize); 104 105 for (int i = 0; i < ranksPerChannel; i++) { 106 Rank* rank = new Rank(*this, p); 107 ranks.push_back(rank); 108 109 rank->actTicks.resize(activationLimit, 0); 110 rank->banks.resize(banksPerRank); 111 rank->rank = i; 112 113 for (int b = 0; b < banksPerRank; b++) { 114 rank->banks[b].bank = b; 115 // GDDR addressing of banks to BG is linear. 116 // Here we assume that all DRAM generations address bank groups as 117 // follows: 118 if (bankGroupArch) { 119 // Simply assign lower bits to bank group in order to 120 // rotate across bank groups as banks are incremented 121 // e.g. with 4 banks per bank group and 16 banks total: 122 // banks 0,4,8,12 are in bank group 0 123 // banks 1,5,9,13 are in bank group 1 124 // banks 2,6,10,14 are in bank group 2 125 // banks 3,7,11,15 are in bank group 3 126 rank->banks[b].bankgr = b % bankGroupsPerRank; 127 } else { 128 // No bank groups; simply assign to bank number 129 rank->banks[b].bankgr = b; 130 } 131 } 132 } 133 134 // perform a basic check of the write thresholds 135 if (p->write_low_thresh_perc >= p->write_high_thresh_perc) 136 fatal("Write buffer low threshold %d must be smaller than the " 137 "high threshold %d\n", p->write_low_thresh_perc, 138 p->write_high_thresh_perc); 139 140 // determine the rows per bank by looking at the total capacity 141 uint64_t capacity = ULL(1) << ceilLog2(AbstractMemory::size()); 142 143 // determine the dram actual capacity from the DRAM config in Mbytes 144 uint64_t deviceCapacity = deviceSize / (1024 * 1024) * devicesPerRank * 145 ranksPerChannel; 146 147 // if actual DRAM size does not match memory capacity in system warn! 148 if (deviceCapacity != capacity / (1024 * 1024)) 149 warn("DRAM device capacity (%d Mbytes) does not match the " 150 "address range assigned (%d Mbytes)\n", deviceCapacity, 151 capacity / (1024 * 1024)); 152 153 DPRINTF(DRAM, "Memory capacity %lld (%lld) bytes\n", capacity, 154 AbstractMemory::size()); 155 156 DPRINTF(DRAM, "Row buffer size %d bytes with %d columns per row buffer\n", 157 rowBufferSize, columnsPerRowBuffer); 158 159 rowsPerBank = capacity / (rowBufferSize * banksPerRank * ranksPerChannel); 160 161 // some basic sanity checks 162 if (tREFI <= tRP || tREFI <= tRFC) { 163 fatal("tREFI (%d) must be larger than tRP (%d) and tRFC (%d)\n", 164 tREFI, tRP, tRFC); 165 } 166 167 // basic bank group architecture checks -> 168 if (bankGroupArch) { 169 // must have at least one bank per bank group 170 if (bankGroupsPerRank > banksPerRank) { 171 fatal("banks per rank (%d) must be equal to or larger than " 172 "banks groups per rank (%d)\n", 173 banksPerRank, bankGroupsPerRank); 174 } 175 // must have same number of banks in each bank group 176 if ((banksPerRank % bankGroupsPerRank) != 0) { 177 fatal("Banks per rank (%d) must be evenly divisible by bank groups " 178 "per rank (%d) for equal banks per bank group\n", 179 banksPerRank, bankGroupsPerRank); 180 } 181 // tCCD_L should be greater than minimal, back-to-back burst delay 182 if (tCCD_L <= tBURST) { 183 fatal("tCCD_L (%d) should be larger than tBURST (%d) when " 184 "bank groups per rank (%d) is greater than 1\n", 185 tCCD_L, tBURST, bankGroupsPerRank); 186 } 187 // tRRD_L is greater than minimal, same bank group ACT-to-ACT delay 188 // some datasheets might specify it equal to tRRD 189 if (tRRD_L < tRRD) { 190 fatal("tRRD_L (%d) should be larger than tRRD (%d) when " 191 "bank groups per rank (%d) is greater than 1\n", 192 tRRD_L, tRRD, bankGroupsPerRank); 193 } 194 } 195 196} 197 198void 199DRAMCtrl::init() 200{ 201 AbstractMemory::init(); 202 203 if (!port.isConnected()) { 204 fatal("DRAMCtrl %s is unconnected!\n", name()); 205 } else { 206 port.sendRangeChange(); 207 } 208 209 // a bit of sanity checks on the interleaving, save it for here to 210 // ensure that the system pointer is initialised 211 if (range.interleaved()) { 212 if (channels != range.stripes()) 213 fatal("%s has %d interleaved address stripes but %d channel(s)\n", 214 name(), range.stripes(), channels); 215 216 if (addrMapping == Enums::RoRaBaChCo) { 217 if (rowBufferSize != range.granularity()) { 218 fatal("Channel interleaving of %s doesn't match RoRaBaChCo " 219 "address map\n", name()); 220 } 221 } else if (addrMapping == Enums::RoRaBaCoCh || 222 addrMapping == Enums::RoCoRaBaCh) { 223 // for the interleavings with channel bits in the bottom, 224 // if the system uses a channel striping granularity that 225 // is larger than the DRAM burst size, then map the 226 // sequential accesses within a stripe to a number of 227 // columns in the DRAM, effectively placing some of the 228 // lower-order column bits as the least-significant bits 229 // of the address (above the ones denoting the burst size) 230 assert(columnsPerStripe >= 1); 231 232 // channel striping has to be done at a granularity that 233 // is equal or larger to a cache line 234 if (system()->cacheLineSize() > range.granularity()) { 235 fatal("Channel interleaving of %s must be at least as large " 236 "as the cache line size\n", name()); 237 } 238 239 // ...and equal or smaller than the row-buffer size 240 if (rowBufferSize < range.granularity()) { 241 fatal("Channel interleaving of %s must be at most as large " 242 "as the row-buffer size\n", name()); 243 } 244 // this is essentially the check above, so just to be sure 245 assert(columnsPerStripe <= columnsPerRowBuffer); 246 } 247 } 248} 249 250void 251DRAMCtrl::startup() 252{ 253 // remember the memory system mode of operation 254 isTimingMode = system()->isTimingMode(); 255 256 if (isTimingMode) { 257 // timestamp offset should be in clock cycles for DRAMPower 258 timeStampOffset = divCeil(curTick(), tCK); 259 260 // update the start tick for the precharge accounting to the 261 // current tick 262 for (auto r : ranks) { 263 r->startup(curTick() + tREFI - tRP); 264 } 265 266 // shift the bus busy time sufficiently far ahead that we never 267 // have to worry about negative values when computing the time for 268 // the next request, this will add an insignificant bubble at the 269 // start of simulation 270 busBusyUntil = curTick() + tRP + tRCD + tCL; 271 } 272} 273 274Tick 275DRAMCtrl::recvAtomic(PacketPtr pkt) 276{ 277 DPRINTF(DRAM, "recvAtomic: %s 0x%x\n", pkt->cmdString(), pkt->getAddr()); 278 279 panic_if(pkt->cacheResponding(), "Should not see packets where cache " 280 "is responding"); 281 282 // do the actual memory access and turn the packet into a response 283 access(pkt); 284 285 Tick latency = 0; 286 if (pkt->hasData()) { 287 // this value is not supposed to be accurate, just enough to 288 // keep things going, mimic a closed page 289 latency = tRP + tRCD + tCL; 290 } 291 return latency; 292} 293 294bool 295DRAMCtrl::readQueueFull(unsigned int neededEntries) const 296{ 297 DPRINTF(DRAM, "Read queue limit %d, current size %d, entries needed %d\n", 298 readBufferSize, readQueue.size() + respQueue.size(), 299 neededEntries); 300 301 return 302 (readQueue.size() + respQueue.size() + neededEntries) > readBufferSize; 303} 304 305bool 306DRAMCtrl::writeQueueFull(unsigned int neededEntries) const 307{ 308 DPRINTF(DRAM, "Write queue limit %d, current size %d, entries needed %d\n", 309 writeBufferSize, writeQueue.size(), neededEntries); 310 return (writeQueue.size() + neededEntries) > writeBufferSize; 311} 312 313DRAMCtrl::DRAMPacket* 314DRAMCtrl::decodeAddr(PacketPtr pkt, Addr dramPktAddr, unsigned size, 315 bool isRead) 316{ 317 // decode the address based on the address mapping scheme, with 318 // Ro, Ra, Co, Ba and Ch denoting row, rank, column, bank and 319 // channel, respectively 320 uint8_t rank; 321 uint8_t bank; 322 // use a 64-bit unsigned during the computations as the row is 323 // always the top bits, and check before creating the DRAMPacket 324 uint64_t row; 325 326 // truncate the address to a DRAM burst, which makes it unique to 327 // a specific column, row, bank, rank and channel 328 Addr addr = dramPktAddr / burstSize; 329 330 // we have removed the lowest order address bits that denote the 331 // position within the column 332 if (addrMapping == Enums::RoRaBaChCo) { 333 // the lowest order bits denote the column to ensure that 334 // sequential cache lines occupy the same row 335 addr = addr / columnsPerRowBuffer; 336 337 // take out the channel part of the address 338 addr = addr / channels; 339 340 // after the channel bits, get the bank bits to interleave 341 // over the banks 342 bank = addr % banksPerRank; 343 addr = addr / banksPerRank; 344 345 // after the bank, we get the rank bits which thus interleaves 346 // over the ranks 347 rank = addr % ranksPerChannel; 348 addr = addr / ranksPerChannel; 349 350 // lastly, get the row bits, no need to remove them from addr 351 row = addr % rowsPerBank; 352 } else if (addrMapping == Enums::RoRaBaCoCh) { 353 // take out the lower-order column bits 354 addr = addr / columnsPerStripe; 355 356 // take out the channel part of the address 357 addr = addr / channels; 358 359 // next, the higher-order column bites 360 addr = addr / (columnsPerRowBuffer / columnsPerStripe); 361 362 // after the column bits, we get the bank bits to interleave 363 // over the banks 364 bank = addr % banksPerRank; 365 addr = addr / banksPerRank; 366 367 // after the bank, we get the rank bits which thus interleaves 368 // over the ranks 369 rank = addr % ranksPerChannel; 370 addr = addr / ranksPerChannel; 371 372 // lastly, get the row bits, no need to remove them from addr 373 row = addr % rowsPerBank; 374 } else if (addrMapping == Enums::RoCoRaBaCh) { 375 // optimise for closed page mode and utilise maximum 376 // parallelism of the DRAM (at the cost of power) 377 378 // take out the lower-order column bits 379 addr = addr / columnsPerStripe; 380 381 // take out the channel part of the address, not that this has 382 // to match with how accesses are interleaved between the 383 // controllers in the address mapping 384 addr = addr / channels; 385 386 // start with the bank bits, as this provides the maximum 387 // opportunity for parallelism between requests 388 bank = addr % banksPerRank; 389 addr = addr / banksPerRank; 390 391 // next get the rank bits 392 rank = addr % ranksPerChannel; 393 addr = addr / ranksPerChannel; 394 395 // next, the higher-order column bites 396 addr = addr / (columnsPerRowBuffer / columnsPerStripe); 397 398 // lastly, get the row bits, no need to remove them from addr 399 row = addr % rowsPerBank; 400 } else 401 panic("Unknown address mapping policy chosen!"); 402 403 assert(rank < ranksPerChannel); 404 assert(bank < banksPerRank); 405 assert(row < rowsPerBank); 406 assert(row < Bank::NO_ROW); 407 408 DPRINTF(DRAM, "Address: %lld Rank %d Bank %d Row %d\n", 409 dramPktAddr, rank, bank, row); 410 411 // create the corresponding DRAM packet with the entry time and 412 // ready time set to the current tick, the latter will be updated 413 // later 414 uint16_t bank_id = banksPerRank * rank + bank; 415 return new DRAMPacket(pkt, isRead, rank, bank, row, bank_id, dramPktAddr, 416 size, ranks[rank]->banks[bank], *ranks[rank]); 417} 418 419void 420DRAMCtrl::addToReadQueue(PacketPtr pkt, unsigned int pktCount) 421{ 422 // only add to the read queue here. whenever the request is 423 // eventually done, set the readyTime, and call schedule() 424 assert(!pkt->isWrite()); 425 426 assert(pktCount != 0); 427 428 // if the request size is larger than burst size, the pkt is split into 429 // multiple DRAM packets 430 // Note if the pkt starting address is not aligened to burst size, the 431 // address of first DRAM packet is kept unaliged. Subsequent DRAM packets 432 // are aligned to burst size boundaries. This is to ensure we accurately 433 // check read packets against packets in write queue. 434 Addr addr = pkt->getAddr(); 435 unsigned pktsServicedByWrQ = 0; 436 BurstHelper* burst_helper = NULL; 437 for (int cnt = 0; cnt < pktCount; ++cnt) { 438 unsigned size = std::min((addr | (burstSize - 1)) + 1, 439 pkt->getAddr() + pkt->getSize()) - addr; 440 readPktSize[ceilLog2(size)]++; 441 readBursts++; 442 443 // First check write buffer to see if the data is already at 444 // the controller 445 bool foundInWrQ = false; 446 Addr burst_addr = burstAlign(addr); 447 // if the burst address is not present then there is no need 448 // looking any further 449 if (isInWriteQueue.find(burst_addr) != isInWriteQueue.end()) { 450 for (const auto& p : writeQueue) { 451 // check if the read is subsumed in the write queue 452 // packet we are looking at 453 if (p->addr <= addr && (addr + size) <= (p->addr + p->size)) { 454 foundInWrQ = true; 455 servicedByWrQ++; 456 pktsServicedByWrQ++; 457 DPRINTF(DRAM, "Read to addr %lld with size %d serviced by " 458 "write queue\n", addr, size); 459 bytesReadWrQ += burstSize; 460 break; 461 } 462 } 463 } 464 465 // If not found in the write q, make a DRAM packet and 466 // push it onto the read queue 467 if (!foundInWrQ) { 468 469 // Make the burst helper for split packets 470 if (pktCount > 1 && burst_helper == NULL) { 471 DPRINTF(DRAM, "Read to addr %lld translates to %d " 472 "dram requests\n", pkt->getAddr(), pktCount); 473 burst_helper = new BurstHelper(pktCount); 474 } 475 476 DRAMPacket* dram_pkt = decodeAddr(pkt, addr, size, true); 477 dram_pkt->burstHelper = burst_helper; 478 479 assert(!readQueueFull(1)); 480 rdQLenPdf[readQueue.size() + respQueue.size()]++; 481 482 DPRINTF(DRAM, "Adding to read queue\n"); 483 484 readQueue.push_back(dram_pkt); 485
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| 486 // increment read entries of the rank 487 ++dram_pkt->rankRef.readEntries; 488
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484 // Update stats 485 avgRdQLen = readQueue.size() + respQueue.size(); 486 } 487 488 // Starting address of next dram pkt (aligend to burstSize boundary) 489 addr = (addr | (burstSize - 1)) + 1; 490 } 491 492 // If all packets are serviced by write queue, we send the repsonse back 493 if (pktsServicedByWrQ == pktCount) { 494 accessAndRespond(pkt, frontendLatency); 495 return; 496 } 497 498 // Update how many split packets are serviced by write queue 499 if (burst_helper != NULL) 500 burst_helper->burstsServiced = pktsServicedByWrQ; 501 502 // If we are not already scheduled to get a request out of the 503 // queue, do so now 504 if (!nextReqEvent.scheduled()) { 505 DPRINTF(DRAM, "Request scheduled immediately\n"); 506 schedule(nextReqEvent, curTick()); 507 } 508} 509 510void 511DRAMCtrl::addToWriteQueue(PacketPtr pkt, unsigned int pktCount) 512{ 513 // only add to the write queue here. whenever the request is 514 // eventually done, set the readyTime, and call schedule() 515 assert(pkt->isWrite()); 516 517 // if the request size is larger than burst size, the pkt is split into 518 // multiple DRAM packets 519 Addr addr = pkt->getAddr(); 520 for (int cnt = 0; cnt < pktCount; ++cnt) { 521 unsigned size = std::min((addr | (burstSize - 1)) + 1, 522 pkt->getAddr() + pkt->getSize()) - addr; 523 writePktSize[ceilLog2(size)]++; 524 writeBursts++; 525 526 // see if we can merge with an existing item in the write 527 // queue and keep track of whether we have merged or not 528 bool merged = isInWriteQueue.find(burstAlign(addr)) != 529 isInWriteQueue.end(); 530 531 // if the item was not merged we need to create a new write 532 // and enqueue it 533 if (!merged) { 534 DRAMPacket* dram_pkt = decodeAddr(pkt, addr, size, false); 535 536 assert(writeQueue.size() < writeBufferSize); 537 wrQLenPdf[writeQueue.size()]++; 538 539 DPRINTF(DRAM, "Adding to write queue\n"); 540 541 writeQueue.push_back(dram_pkt); 542 isInWriteQueue.insert(burstAlign(addr)); 543 assert(writeQueue.size() == isInWriteQueue.size()); 544 545 // Update stats 546 avgWrQLen = writeQueue.size();
| 489 // Update stats 490 avgRdQLen = readQueue.size() + respQueue.size(); 491 } 492 493 // Starting address of next dram pkt (aligend to burstSize boundary) 494 addr = (addr | (burstSize - 1)) + 1; 495 } 496 497 // If all packets are serviced by write queue, we send the repsonse back 498 if (pktsServicedByWrQ == pktCount) { 499 accessAndRespond(pkt, frontendLatency); 500 return; 501 } 502 503 // Update how many split packets are serviced by write queue 504 if (burst_helper != NULL) 505 burst_helper->burstsServiced = pktsServicedByWrQ; 506 507 // If we are not already scheduled to get a request out of the 508 // queue, do so now 509 if (!nextReqEvent.scheduled()) { 510 DPRINTF(DRAM, "Request scheduled immediately\n"); 511 schedule(nextReqEvent, curTick()); 512 } 513} 514 515void 516DRAMCtrl::addToWriteQueue(PacketPtr pkt, unsigned int pktCount) 517{ 518 // only add to the write queue here. whenever the request is 519 // eventually done, set the readyTime, and call schedule() 520 assert(pkt->isWrite()); 521 522 // if the request size is larger than burst size, the pkt is split into 523 // multiple DRAM packets 524 Addr addr = pkt->getAddr(); 525 for (int cnt = 0; cnt < pktCount; ++cnt) { 526 unsigned size = std::min((addr | (burstSize - 1)) + 1, 527 pkt->getAddr() + pkt->getSize()) - addr; 528 writePktSize[ceilLog2(size)]++; 529 writeBursts++; 530 531 // see if we can merge with an existing item in the write 532 // queue and keep track of whether we have merged or not 533 bool merged = isInWriteQueue.find(burstAlign(addr)) != 534 isInWriteQueue.end(); 535 536 // if the item was not merged we need to create a new write 537 // and enqueue it 538 if (!merged) { 539 DRAMPacket* dram_pkt = decodeAddr(pkt, addr, size, false); 540 541 assert(writeQueue.size() < writeBufferSize); 542 wrQLenPdf[writeQueue.size()]++; 543 544 DPRINTF(DRAM, "Adding to write queue\n"); 545 546 writeQueue.push_back(dram_pkt); 547 isInWriteQueue.insert(burstAlign(addr)); 548 assert(writeQueue.size() == isInWriteQueue.size()); 549 550 // Update stats 551 avgWrQLen = writeQueue.size();
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| 552 553 // increment write entries of the rank 554 ++dram_pkt->rankRef.writeEntries;
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547 } else { 548 DPRINTF(DRAM, "Merging write burst with existing queue entry\n"); 549 550 // keep track of the fact that this burst effectively 551 // disappeared as it was merged with an existing one 552 mergedWrBursts++; 553 } 554 555 // Starting address of next dram pkt (aligend to burstSize boundary) 556 addr = (addr | (burstSize - 1)) + 1; 557 } 558 559 // we do not wait for the writes to be send to the actual memory, 560 // but instead take responsibility for the consistency here and 561 // snoop the write queue for any upcoming reads 562 // @todo, if a pkt size is larger than burst size, we might need a 563 // different front end latency 564 accessAndRespond(pkt, frontendLatency); 565 566 // If we are not already scheduled to get a request out of the 567 // queue, do so now 568 if (!nextReqEvent.scheduled()) { 569 DPRINTF(DRAM, "Request scheduled immediately\n"); 570 schedule(nextReqEvent, curTick()); 571 } 572} 573 574void 575DRAMCtrl::printQs() const { 576 DPRINTF(DRAM, "===READ QUEUE===\n\n"); 577 for (auto i = readQueue.begin() ; i != readQueue.end() ; ++i) { 578 DPRINTF(DRAM, "Read %lu\n", (*i)->addr); 579 } 580 DPRINTF(DRAM, "\n===RESP QUEUE===\n\n"); 581 for (auto i = respQueue.begin() ; i != respQueue.end() ; ++i) { 582 DPRINTF(DRAM, "Response %lu\n", (*i)->addr); 583 } 584 DPRINTF(DRAM, "\n===WRITE QUEUE===\n\n"); 585 for (auto i = writeQueue.begin() ; i != writeQueue.end() ; ++i) { 586 DPRINTF(DRAM, "Write %lu\n", (*i)->addr); 587 } 588} 589 590bool 591DRAMCtrl::recvTimingReq(PacketPtr pkt) 592{ 593 // This is where we enter from the outside world 594 DPRINTF(DRAM, "recvTimingReq: request %s addr %lld size %d\n", 595 pkt->cmdString(), pkt->getAddr(), pkt->getSize()); 596 597 panic_if(pkt->cacheResponding(), "Should not see packets where cache " 598 "is responding"); 599 600 panic_if(!(pkt->isRead() || pkt->isWrite()), 601 "Should only see read and writes at memory controller\n"); 602 603 // Calc avg gap between requests 604 if (prevArrival != 0) { 605 totGap += curTick() - prevArrival; 606 } 607 prevArrival = curTick(); 608 609 610 // Find out how many dram packets a pkt translates to 611 // If the burst size is equal or larger than the pkt size, then a pkt 612 // translates to only one dram packet. Otherwise, a pkt translates to 613 // multiple dram packets 614 unsigned size = pkt->getSize(); 615 unsigned offset = pkt->getAddr() & (burstSize - 1); 616 unsigned int dram_pkt_count = divCeil(offset + size, burstSize); 617 618 // check local buffers and do not accept if full 619 if (pkt->isRead()) { 620 assert(size != 0); 621 if (readQueueFull(dram_pkt_count)) { 622 DPRINTF(DRAM, "Read queue full, not accepting\n"); 623 // remember that we have to retry this port 624 retryRdReq = true; 625 numRdRetry++; 626 return false; 627 } else { 628 addToReadQueue(pkt, dram_pkt_count); 629 readReqs++; 630 bytesReadSys += size; 631 } 632 } else { 633 assert(pkt->isWrite()); 634 assert(size != 0); 635 if (writeQueueFull(dram_pkt_count)) { 636 DPRINTF(DRAM, "Write queue full, not accepting\n"); 637 // remember that we have to retry this port 638 retryWrReq = true; 639 numWrRetry++; 640 return false; 641 } else { 642 addToWriteQueue(pkt, dram_pkt_count); 643 writeReqs++; 644 bytesWrittenSys += size; 645 } 646 } 647 648 return true; 649} 650 651void 652DRAMCtrl::processRespondEvent() 653{ 654 DPRINTF(DRAM, 655 "processRespondEvent(): Some req has reached its readyTime\n"); 656 657 DRAMPacket* dram_pkt = respQueue.front(); 658
| 555 } else { 556 DPRINTF(DRAM, "Merging write burst with existing queue entry\n"); 557 558 // keep track of the fact that this burst effectively 559 // disappeared as it was merged with an existing one 560 mergedWrBursts++; 561 } 562 563 // Starting address of next dram pkt (aligend to burstSize boundary) 564 addr = (addr | (burstSize - 1)) + 1; 565 } 566 567 // we do not wait for the writes to be send to the actual memory, 568 // but instead take responsibility for the consistency here and 569 // snoop the write queue for any upcoming reads 570 // @todo, if a pkt size is larger than burst size, we might need a 571 // different front end latency 572 accessAndRespond(pkt, frontendLatency); 573 574 // If we are not already scheduled to get a request out of the 575 // queue, do so now 576 if (!nextReqEvent.scheduled()) { 577 DPRINTF(DRAM, "Request scheduled immediately\n"); 578 schedule(nextReqEvent, curTick()); 579 } 580} 581 582void 583DRAMCtrl::printQs() const { 584 DPRINTF(DRAM, "===READ QUEUE===\n\n"); 585 for (auto i = readQueue.begin() ; i != readQueue.end() ; ++i) { 586 DPRINTF(DRAM, "Read %lu\n", (*i)->addr); 587 } 588 DPRINTF(DRAM, "\n===RESP QUEUE===\n\n"); 589 for (auto i = respQueue.begin() ; i != respQueue.end() ; ++i) { 590 DPRINTF(DRAM, "Response %lu\n", (*i)->addr); 591 } 592 DPRINTF(DRAM, "\n===WRITE QUEUE===\n\n"); 593 for (auto i = writeQueue.begin() ; i != writeQueue.end() ; ++i) { 594 DPRINTF(DRAM, "Write %lu\n", (*i)->addr); 595 } 596} 597 598bool 599DRAMCtrl::recvTimingReq(PacketPtr pkt) 600{ 601 // This is where we enter from the outside world 602 DPRINTF(DRAM, "recvTimingReq: request %s addr %lld size %d\n", 603 pkt->cmdString(), pkt->getAddr(), pkt->getSize()); 604 605 panic_if(pkt->cacheResponding(), "Should not see packets where cache " 606 "is responding"); 607 608 panic_if(!(pkt->isRead() || pkt->isWrite()), 609 "Should only see read and writes at memory controller\n"); 610 611 // Calc avg gap between requests 612 if (prevArrival != 0) { 613 totGap += curTick() - prevArrival; 614 } 615 prevArrival = curTick(); 616 617 618 // Find out how many dram packets a pkt translates to 619 // If the burst size is equal or larger than the pkt size, then a pkt 620 // translates to only one dram packet. Otherwise, a pkt translates to 621 // multiple dram packets 622 unsigned size = pkt->getSize(); 623 unsigned offset = pkt->getAddr() & (burstSize - 1); 624 unsigned int dram_pkt_count = divCeil(offset + size, burstSize); 625 626 // check local buffers and do not accept if full 627 if (pkt->isRead()) { 628 assert(size != 0); 629 if (readQueueFull(dram_pkt_count)) { 630 DPRINTF(DRAM, "Read queue full, not accepting\n"); 631 // remember that we have to retry this port 632 retryRdReq = true; 633 numRdRetry++; 634 return false; 635 } else { 636 addToReadQueue(pkt, dram_pkt_count); 637 readReqs++; 638 bytesReadSys += size; 639 } 640 } else { 641 assert(pkt->isWrite()); 642 assert(size != 0); 643 if (writeQueueFull(dram_pkt_count)) { 644 DPRINTF(DRAM, "Write queue full, not accepting\n"); 645 // remember that we have to retry this port 646 retryWrReq = true; 647 numWrRetry++; 648 return false; 649 } else { 650 addToWriteQueue(pkt, dram_pkt_count); 651 writeReqs++; 652 bytesWrittenSys += size; 653 } 654 } 655 656 return true; 657} 658 659void 660DRAMCtrl::processRespondEvent() 661{ 662 DPRINTF(DRAM, 663 "processRespondEvent(): Some req has reached its readyTime\n"); 664 665 DRAMPacket* dram_pkt = respQueue.front(); 666
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| 667 // if a read has reached its ready-time, decrement the number of reads 668 // At this point the packet has been handled and there is a possibility 669 // to switch to low-power mode if no other packet is available 670 --dram_pkt->rankRef.readEntries; 671 DPRINTF(DRAM, "number of read entries for rank %d is %d\n", 672 dram_pkt->rank, dram_pkt->rankRef.readEntries); 673 674 // counter should at least indicate one outstanding request 675 // for this read 676 assert(dram_pkt->rankRef.outstandingEvents > 0); 677 // read response received, decrement count 678 --dram_pkt->rankRef.outstandingEvents; 679 680 // at this moment should be either ACT or IDLE depending on 681 // if PRE has occurred to close all banks 682 assert((dram_pkt->rankRef.pwrState == PWR_ACT) || 683 (dram_pkt->rankRef.pwrState == PWR_IDLE)); 684 685 // track if this is the last packet before idling 686 // and that there are no outstanding commands to this rank 687 if (dram_pkt->rankRef.lowPowerEntryReady()) { 688 // verify that there are no events scheduled 689 assert(!dram_pkt->rankRef.activateEvent.scheduled()); 690 assert(!dram_pkt->rankRef.prechargeEvent.scheduled()); 691 assert(dram_pkt->rankRef.refreshState == REF_IDLE); 692 693 // if coming from active state, schedule power event to 694 // active power-down else go to precharge power-down 695 DPRINTF(DRAMState, "Rank %d sleep at tick %d; current power state is " 696 "%d\n", dram_pkt->rank, curTick(), dram_pkt->rankRef.pwrState); 697 698 // default to ACT power-down unless already in IDLE state 699 // could be in IDLE if PRE issued before data returned 700 PowerState next_pwr_state = PWR_ACT_PDN; 701 if (dram_pkt->rankRef.pwrState == PWR_IDLE) { 702 next_pwr_state = PWR_PRE_PDN; 703 } 704 705 dram_pkt->rankRef.powerDownSleep(next_pwr_state, curTick()); 706 } 707
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659 if (dram_pkt->burstHelper) { 660 // it is a split packet 661 dram_pkt->burstHelper->burstsServiced++; 662 if (dram_pkt->burstHelper->burstsServiced == 663 dram_pkt->burstHelper->burstCount) { 664 // we have now serviced all children packets of a system packet 665 // so we can now respond to the requester 666 // @todo we probably want to have a different front end and back 667 // end latency for split packets 668 accessAndRespond(dram_pkt->pkt, frontendLatency + backendLatency); 669 delete dram_pkt->burstHelper; 670 dram_pkt->burstHelper = NULL; 671 } 672 } else { 673 // it is not a split packet 674 accessAndRespond(dram_pkt->pkt, frontendLatency + backendLatency); 675 } 676 677 delete respQueue.front(); 678 respQueue.pop_front(); 679 680 if (!respQueue.empty()) { 681 assert(respQueue.front()->readyTime >= curTick()); 682 assert(!respondEvent.scheduled()); 683 schedule(respondEvent, respQueue.front()->readyTime); 684 } else { 685 // if there is nothing left in any queue, signal a drain 686 if (drainState() == DrainState::Draining && 687 writeQueue.empty() && readQueue.empty() && allRanksDrained()) { 688 689 DPRINTF(Drain, "DRAM controller done draining\n"); 690 signalDrainDone(); 691 } 692 } 693 694 // We have made a location in the queue available at this point, 695 // so if there is a read that was forced to wait, retry now 696 if (retryRdReq) { 697 retryRdReq = false; 698 port.sendRetryReq(); 699 } 700} 701 702bool 703DRAMCtrl::chooseNext(std::deque<DRAMPacket*>& queue, Tick extra_col_delay) 704{ 705 // This method does the arbitration between requests. The chosen 706 // packet is simply moved to the head of the queue. The other 707 // methods know that this is the place to look. For example, with 708 // FCFS, this method does nothing 709 assert(!queue.empty()); 710 711 // bool to indicate if a packet to an available rank is found 712 bool found_packet = false; 713 if (queue.size() == 1) { 714 DRAMPacket* dram_pkt = queue.front(); 715 // available rank corresponds to state refresh idle 716 if (ranks[dram_pkt->rank]->isAvailable()) { 717 found_packet = true; 718 DPRINTF(DRAM, "Single request, going to a free rank\n"); 719 } else { 720 DPRINTF(DRAM, "Single request, going to a busy rank\n"); 721 } 722 return found_packet; 723 } 724 725 if (memSchedPolicy == Enums::fcfs) { 726 // check if there is a packet going to a free rank 727 for (auto i = queue.begin(); i != queue.end() ; ++i) { 728 DRAMPacket* dram_pkt = *i; 729 if (ranks[dram_pkt->rank]->isAvailable()) { 730 queue.erase(i); 731 queue.push_front(dram_pkt); 732 found_packet = true; 733 break; 734 } 735 } 736 } else if (memSchedPolicy == Enums::frfcfs) { 737 found_packet = reorderQueue(queue, extra_col_delay); 738 } else 739 panic("No scheduling policy chosen\n"); 740 return found_packet; 741} 742 743bool 744DRAMCtrl::reorderQueue(std::deque<DRAMPacket*>& queue, Tick extra_col_delay) 745{ 746 // Only determine this if needed 747 uint64_t earliest_banks = 0; 748 bool hidden_bank_prep = false; 749 750 // search for seamless row hits first, if no seamless row hit is 751 // found then determine if there are other packets that can be issued 752 // without incurring additional bus delay due to bank timing 753 // Will select closed rows first to enable more open row possibilies 754 // in future selections 755 bool found_hidden_bank = false; 756 757 // remember if we found a row hit, not seamless, but bank prepped 758 // and ready 759 bool found_prepped_pkt = false; 760 761 // if we have no row hit, prepped or not, and no seamless packet, 762 // just go for the earliest possible 763 bool found_earliest_pkt = false; 764 765 auto selected_pkt_it = queue.end(); 766 767 // time we need to issue a column command to be seamless 768 const Tick min_col_at = std::max(busBusyUntil - tCL + extra_col_delay, 769 curTick()); 770 771 for (auto i = queue.begin(); i != queue.end() ; ++i) { 772 DRAMPacket* dram_pkt = *i; 773 const Bank& bank = dram_pkt->bankRef; 774 775 // check if rank is available, if not, jump to the next packet 776 if (dram_pkt->rankRef.isAvailable()) { 777 // check if it is a row hit 778 if (bank.openRow == dram_pkt->row) { 779 // no additional rank-to-rank or same bank-group 780 // delays, or we switched read/write and might as well 781 // go for the row hit 782 if (bank.colAllowedAt <= min_col_at) { 783 // FCFS within the hits, giving priority to 784 // commands that can issue seamlessly, without 785 // additional delay, such as same rank accesses 786 // and/or different bank-group accesses 787 DPRINTF(DRAM, "Seamless row buffer hit\n"); 788 selected_pkt_it = i; 789 // no need to look through the remaining queue entries 790 break; 791 } else if (!found_hidden_bank && !found_prepped_pkt) { 792 // if we did not find a packet to a closed row that can 793 // issue the bank commands without incurring delay, and 794 // did not yet find a packet to a prepped row, remember 795 // the current one 796 selected_pkt_it = i; 797 found_prepped_pkt = true; 798 DPRINTF(DRAM, "Prepped row buffer hit\n"); 799 } 800 } else if (!found_earliest_pkt) { 801 // if we have not initialised the bank status, do it 802 // now, and only once per scheduling decisions 803 if (earliest_banks == 0) { 804 // determine entries with earliest bank delay 805 pair<uint64_t, bool> bankStatus = 806 minBankPrep(queue, min_col_at); 807 earliest_banks = bankStatus.first; 808 hidden_bank_prep = bankStatus.second; 809 } 810 811 // bank is amongst first available banks 812 // minBankPrep will give priority to packets that can 813 // issue seamlessly 814 if (bits(earliest_banks, dram_pkt->bankId, dram_pkt->bankId)) { 815 found_earliest_pkt = true; 816 found_hidden_bank = hidden_bank_prep; 817 818 // give priority to packets that can issue 819 // bank commands 'behind the scenes' 820 // any additional delay if any will be due to 821 // col-to-col command requirements 822 if (hidden_bank_prep || !found_prepped_pkt) 823 selected_pkt_it = i; 824 } 825 } 826 } 827 } 828 829 if (selected_pkt_it != queue.end()) { 830 DRAMPacket* selected_pkt = *selected_pkt_it; 831 queue.erase(selected_pkt_it); 832 queue.push_front(selected_pkt); 833 return true; 834 } 835 836 return false; 837} 838 839void 840DRAMCtrl::accessAndRespond(PacketPtr pkt, Tick static_latency) 841{ 842 DPRINTF(DRAM, "Responding to Address %lld.. ",pkt->getAddr()); 843 844 bool needsResponse = pkt->needsResponse(); 845 // do the actual memory access which also turns the packet into a 846 // response 847 access(pkt); 848 849 // turn packet around to go back to requester if response expected 850 if (needsResponse) { 851 // access already turned the packet into a response 852 assert(pkt->isResponse()); 853 // response_time consumes the static latency and is charged also 854 // with headerDelay that takes into account the delay provided by 855 // the xbar and also the payloadDelay that takes into account the 856 // number of data beats. 857 Tick response_time = curTick() + static_latency + pkt->headerDelay + 858 pkt->payloadDelay; 859 // Here we reset the timing of the packet before sending it out. 860 pkt->headerDelay = pkt->payloadDelay = 0; 861 862 // queue the packet in the response queue to be sent out after 863 // the static latency has passed 864 port.schedTimingResp(pkt, response_time, true); 865 } else { 866 // @todo the packet is going to be deleted, and the DRAMPacket 867 // is still having a pointer to it 868 pendingDelete.reset(pkt); 869 } 870 871 DPRINTF(DRAM, "Done\n"); 872 873 return; 874} 875 876void 877DRAMCtrl::activateBank(Rank& rank_ref, Bank& bank_ref, 878 Tick act_tick, uint32_t row) 879{ 880 assert(rank_ref.actTicks.size() == activationLimit); 881 882 DPRINTF(DRAM, "Activate at tick %d\n", act_tick); 883 884 // update the open row 885 assert(bank_ref.openRow == Bank::NO_ROW); 886 bank_ref.openRow = row; 887 888 // start counting anew, this covers both the case when we 889 // auto-precharged, and when this access is forced to 890 // precharge 891 bank_ref.bytesAccessed = 0; 892 bank_ref.rowAccesses = 0; 893 894 ++rank_ref.numBanksActive; 895 assert(rank_ref.numBanksActive <= banksPerRank); 896 897 DPRINTF(DRAM, "Activate bank %d, rank %d at tick %lld, now got %d active\n", 898 bank_ref.bank, rank_ref.rank, act_tick, 899 ranks[rank_ref.rank]->numBanksActive); 900 901 rank_ref.cmdList.push_back(Command(MemCommand::ACT, bank_ref.bank, 902 act_tick)); 903 904 DPRINTF(DRAMPower, "%llu,ACT,%d,%d\n", divCeil(act_tick, tCK) - 905 timeStampOffset, bank_ref.bank, rank_ref.rank); 906 907 // The next access has to respect tRAS for this bank 908 bank_ref.preAllowedAt = act_tick + tRAS; 909 910 // Respect the row-to-column command delay 911 bank_ref.colAllowedAt = std::max(act_tick + tRCD, bank_ref.colAllowedAt); 912 913 // start by enforcing tRRD 914 for (int i = 0; i < banksPerRank; i++) { 915 // next activate to any bank in this rank must not happen 916 // before tRRD 917 if (bankGroupArch && (bank_ref.bankgr == rank_ref.banks[i].bankgr)) { 918 // bank group architecture requires longer delays between 919 // ACT commands within the same bank group. Use tRRD_L 920 // in this case 921 rank_ref.banks[i].actAllowedAt = std::max(act_tick + tRRD_L, 922 rank_ref.banks[i].actAllowedAt); 923 } else { 924 // use shorter tRRD value when either 925 // 1) bank group architecture is not supportted 926 // 2) bank is in a different bank group 927 rank_ref.banks[i].actAllowedAt = std::max(act_tick + tRRD, 928 rank_ref.banks[i].actAllowedAt); 929 } 930 } 931 932 // next, we deal with tXAW, if the activation limit is disabled 933 // then we directly schedule an activate power event 934 if (!rank_ref.actTicks.empty()) { 935 // sanity check 936 if (rank_ref.actTicks.back() && 937 (act_tick - rank_ref.actTicks.back()) < tXAW) { 938 panic("Got %d activates in window %d (%llu - %llu) which " 939 "is smaller than %llu\n", activationLimit, act_tick - 940 rank_ref.actTicks.back(), act_tick, 941 rank_ref.actTicks.back(), tXAW); 942 } 943 944 // shift the times used for the book keeping, the last element 945 // (highest index) is the oldest one and hence the lowest value 946 rank_ref.actTicks.pop_back(); 947 948 // record an new activation (in the future) 949 rank_ref.actTicks.push_front(act_tick); 950 951 // cannot activate more than X times in time window tXAW, push the 952 // next one (the X + 1'st activate) to be tXAW away from the 953 // oldest in our window of X 954 if (rank_ref.actTicks.back() && 955 (act_tick - rank_ref.actTicks.back()) < tXAW) { 956 DPRINTF(DRAM, "Enforcing tXAW with X = %d, next activate " 957 "no earlier than %llu\n", activationLimit, 958 rank_ref.actTicks.back() + tXAW); 959 for (int j = 0; j < banksPerRank; j++) 960 // next activate must not happen before end of window 961 rank_ref.banks[j].actAllowedAt = 962 std::max(rank_ref.actTicks.back() + tXAW, 963 rank_ref.banks[j].actAllowedAt); 964 } 965 } 966 967 // at the point when this activate takes place, make sure we 968 // transition to the active power state 969 if (!rank_ref.activateEvent.scheduled()) 970 schedule(rank_ref.activateEvent, act_tick); 971 else if (rank_ref.activateEvent.when() > act_tick) 972 // move it sooner in time 973 reschedule(rank_ref.activateEvent, act_tick); 974} 975 976void 977DRAMCtrl::prechargeBank(Rank& rank_ref, Bank& bank, Tick pre_at, bool trace) 978{ 979 // make sure the bank has an open row 980 assert(bank.openRow != Bank::NO_ROW); 981 982 // sample the bytes per activate here since we are closing 983 // the page 984 bytesPerActivate.sample(bank.bytesAccessed); 985 986 bank.openRow = Bank::NO_ROW; 987 988 // no precharge allowed before this one 989 bank.preAllowedAt = pre_at; 990 991 Tick pre_done_at = pre_at + tRP; 992 993 bank.actAllowedAt = std::max(bank.actAllowedAt, pre_done_at); 994 995 assert(rank_ref.numBanksActive != 0); 996 --rank_ref.numBanksActive; 997 998 DPRINTF(DRAM, "Precharging bank %d, rank %d at tick %lld, now got " 999 "%d active\n", bank.bank, rank_ref.rank, pre_at, 1000 rank_ref.numBanksActive); 1001 1002 if (trace) { 1003 1004 rank_ref.cmdList.push_back(Command(MemCommand::PRE, bank.bank, 1005 pre_at)); 1006 DPRINTF(DRAMPower, "%llu,PRE,%d,%d\n", divCeil(pre_at, tCK) - 1007 timeStampOffset, bank.bank, rank_ref.rank); 1008 } 1009 // if we look at the current number of active banks we might be 1010 // tempted to think the DRAM is now idle, however this can be 1011 // undone by an activate that is scheduled to happen before we 1012 // would have reached the idle state, so schedule an event and 1013 // rather check once we actually make it to the point in time when 1014 // the (last) precharge takes place
| 708 if (dram_pkt->burstHelper) { 709 // it is a split packet 710 dram_pkt->burstHelper->burstsServiced++; 711 if (dram_pkt->burstHelper->burstsServiced == 712 dram_pkt->burstHelper->burstCount) { 713 // we have now serviced all children packets of a system packet 714 // so we can now respond to the requester 715 // @todo we probably want to have a different front end and back 716 // end latency for split packets 717 accessAndRespond(dram_pkt->pkt, frontendLatency + backendLatency); 718 delete dram_pkt->burstHelper; 719 dram_pkt->burstHelper = NULL; 720 } 721 } else { 722 // it is not a split packet 723 accessAndRespond(dram_pkt->pkt, frontendLatency + backendLatency); 724 } 725 726 delete respQueue.front(); 727 respQueue.pop_front(); 728 729 if (!respQueue.empty()) { 730 assert(respQueue.front()->readyTime >= curTick()); 731 assert(!respondEvent.scheduled()); 732 schedule(respondEvent, respQueue.front()->readyTime); 733 } else { 734 // if there is nothing left in any queue, signal a drain 735 if (drainState() == DrainState::Draining && 736 writeQueue.empty() && readQueue.empty() && allRanksDrained()) { 737 738 DPRINTF(Drain, "DRAM controller done draining\n"); 739 signalDrainDone(); 740 } 741 } 742 743 // We have made a location in the queue available at this point, 744 // so if there is a read that was forced to wait, retry now 745 if (retryRdReq) { 746 retryRdReq = false; 747 port.sendRetryReq(); 748 } 749} 750 751bool 752DRAMCtrl::chooseNext(std::deque<DRAMPacket*>& queue, Tick extra_col_delay) 753{ 754 // This method does the arbitration between requests. The chosen 755 // packet is simply moved to the head of the queue. The other 756 // methods know that this is the place to look. For example, with 757 // FCFS, this method does nothing 758 assert(!queue.empty()); 759 760 // bool to indicate if a packet to an available rank is found 761 bool found_packet = false; 762 if (queue.size() == 1) { 763 DRAMPacket* dram_pkt = queue.front(); 764 // available rank corresponds to state refresh idle 765 if (ranks[dram_pkt->rank]->isAvailable()) { 766 found_packet = true; 767 DPRINTF(DRAM, "Single request, going to a free rank\n"); 768 } else { 769 DPRINTF(DRAM, "Single request, going to a busy rank\n"); 770 } 771 return found_packet; 772 } 773 774 if (memSchedPolicy == Enums::fcfs) { 775 // check if there is a packet going to a free rank 776 for (auto i = queue.begin(); i != queue.end() ; ++i) { 777 DRAMPacket* dram_pkt = *i; 778 if (ranks[dram_pkt->rank]->isAvailable()) { 779 queue.erase(i); 780 queue.push_front(dram_pkt); 781 found_packet = true; 782 break; 783 } 784 } 785 } else if (memSchedPolicy == Enums::frfcfs) { 786 found_packet = reorderQueue(queue, extra_col_delay); 787 } else 788 panic("No scheduling policy chosen\n"); 789 return found_packet; 790} 791 792bool 793DRAMCtrl::reorderQueue(std::deque<DRAMPacket*>& queue, Tick extra_col_delay) 794{ 795 // Only determine this if needed 796 uint64_t earliest_banks = 0; 797 bool hidden_bank_prep = false; 798 799 // search for seamless row hits first, if no seamless row hit is 800 // found then determine if there are other packets that can be issued 801 // without incurring additional bus delay due to bank timing 802 // Will select closed rows first to enable more open row possibilies 803 // in future selections 804 bool found_hidden_bank = false; 805 806 // remember if we found a row hit, not seamless, but bank prepped 807 // and ready 808 bool found_prepped_pkt = false; 809 810 // if we have no row hit, prepped or not, and no seamless packet, 811 // just go for the earliest possible 812 bool found_earliest_pkt = false; 813 814 auto selected_pkt_it = queue.end(); 815 816 // time we need to issue a column command to be seamless 817 const Tick min_col_at = std::max(busBusyUntil - tCL + extra_col_delay, 818 curTick()); 819 820 for (auto i = queue.begin(); i != queue.end() ; ++i) { 821 DRAMPacket* dram_pkt = *i; 822 const Bank& bank = dram_pkt->bankRef; 823 824 // check if rank is available, if not, jump to the next packet 825 if (dram_pkt->rankRef.isAvailable()) { 826 // check if it is a row hit 827 if (bank.openRow == dram_pkt->row) { 828 // no additional rank-to-rank or same bank-group 829 // delays, or we switched read/write and might as well 830 // go for the row hit 831 if (bank.colAllowedAt <= min_col_at) { 832 // FCFS within the hits, giving priority to 833 // commands that can issue seamlessly, without 834 // additional delay, such as same rank accesses 835 // and/or different bank-group accesses 836 DPRINTF(DRAM, "Seamless row buffer hit\n"); 837 selected_pkt_it = i; 838 // no need to look through the remaining queue entries 839 break; 840 } else if (!found_hidden_bank && !found_prepped_pkt) { 841 // if we did not find a packet to a closed row that can 842 // issue the bank commands without incurring delay, and 843 // did not yet find a packet to a prepped row, remember 844 // the current one 845 selected_pkt_it = i; 846 found_prepped_pkt = true; 847 DPRINTF(DRAM, "Prepped row buffer hit\n"); 848 } 849 } else if (!found_earliest_pkt) { 850 // if we have not initialised the bank status, do it 851 // now, and only once per scheduling decisions 852 if (earliest_banks == 0) { 853 // determine entries with earliest bank delay 854 pair<uint64_t, bool> bankStatus = 855 minBankPrep(queue, min_col_at); 856 earliest_banks = bankStatus.first; 857 hidden_bank_prep = bankStatus.second; 858 } 859 860 // bank is amongst first available banks 861 // minBankPrep will give priority to packets that can 862 // issue seamlessly 863 if (bits(earliest_banks, dram_pkt->bankId, dram_pkt->bankId)) { 864 found_earliest_pkt = true; 865 found_hidden_bank = hidden_bank_prep; 866 867 // give priority to packets that can issue 868 // bank commands 'behind the scenes' 869 // any additional delay if any will be due to 870 // col-to-col command requirements 871 if (hidden_bank_prep || !found_prepped_pkt) 872 selected_pkt_it = i; 873 } 874 } 875 } 876 } 877 878 if (selected_pkt_it != queue.end()) { 879 DRAMPacket* selected_pkt = *selected_pkt_it; 880 queue.erase(selected_pkt_it); 881 queue.push_front(selected_pkt); 882 return true; 883 } 884 885 return false; 886} 887 888void 889DRAMCtrl::accessAndRespond(PacketPtr pkt, Tick static_latency) 890{ 891 DPRINTF(DRAM, "Responding to Address %lld.. ",pkt->getAddr()); 892 893 bool needsResponse = pkt->needsResponse(); 894 // do the actual memory access which also turns the packet into a 895 // response 896 access(pkt); 897 898 // turn packet around to go back to requester if response expected 899 if (needsResponse) { 900 // access already turned the packet into a response 901 assert(pkt->isResponse()); 902 // response_time consumes the static latency and is charged also 903 // with headerDelay that takes into account the delay provided by 904 // the xbar and also the payloadDelay that takes into account the 905 // number of data beats. 906 Tick response_time = curTick() + static_latency + pkt->headerDelay + 907 pkt->payloadDelay; 908 // Here we reset the timing of the packet before sending it out. 909 pkt->headerDelay = pkt->payloadDelay = 0; 910 911 // queue the packet in the response queue to be sent out after 912 // the static latency has passed 913 port.schedTimingResp(pkt, response_time, true); 914 } else { 915 // @todo the packet is going to be deleted, and the DRAMPacket 916 // is still having a pointer to it 917 pendingDelete.reset(pkt); 918 } 919 920 DPRINTF(DRAM, "Done\n"); 921 922 return; 923} 924 925void 926DRAMCtrl::activateBank(Rank& rank_ref, Bank& bank_ref, 927 Tick act_tick, uint32_t row) 928{ 929 assert(rank_ref.actTicks.size() == activationLimit); 930 931 DPRINTF(DRAM, "Activate at tick %d\n", act_tick); 932 933 // update the open row 934 assert(bank_ref.openRow == Bank::NO_ROW); 935 bank_ref.openRow = row; 936 937 // start counting anew, this covers both the case when we 938 // auto-precharged, and when this access is forced to 939 // precharge 940 bank_ref.bytesAccessed = 0; 941 bank_ref.rowAccesses = 0; 942 943 ++rank_ref.numBanksActive; 944 assert(rank_ref.numBanksActive <= banksPerRank); 945 946 DPRINTF(DRAM, "Activate bank %d, rank %d at tick %lld, now got %d active\n", 947 bank_ref.bank, rank_ref.rank, act_tick, 948 ranks[rank_ref.rank]->numBanksActive); 949 950 rank_ref.cmdList.push_back(Command(MemCommand::ACT, bank_ref.bank, 951 act_tick)); 952 953 DPRINTF(DRAMPower, "%llu,ACT,%d,%d\n", divCeil(act_tick, tCK) - 954 timeStampOffset, bank_ref.bank, rank_ref.rank); 955 956 // The next access has to respect tRAS for this bank 957 bank_ref.preAllowedAt = act_tick + tRAS; 958 959 // Respect the row-to-column command delay 960 bank_ref.colAllowedAt = std::max(act_tick + tRCD, bank_ref.colAllowedAt); 961 962 // start by enforcing tRRD 963 for (int i = 0; i < banksPerRank; i++) { 964 // next activate to any bank in this rank must not happen 965 // before tRRD 966 if (bankGroupArch && (bank_ref.bankgr == rank_ref.banks[i].bankgr)) { 967 // bank group architecture requires longer delays between 968 // ACT commands within the same bank group. Use tRRD_L 969 // in this case 970 rank_ref.banks[i].actAllowedAt = std::max(act_tick + tRRD_L, 971 rank_ref.banks[i].actAllowedAt); 972 } else { 973 // use shorter tRRD value when either 974 // 1) bank group architecture is not supportted 975 // 2) bank is in a different bank group 976 rank_ref.banks[i].actAllowedAt = std::max(act_tick + tRRD, 977 rank_ref.banks[i].actAllowedAt); 978 } 979 } 980 981 // next, we deal with tXAW, if the activation limit is disabled 982 // then we directly schedule an activate power event 983 if (!rank_ref.actTicks.empty()) { 984 // sanity check 985 if (rank_ref.actTicks.back() && 986 (act_tick - rank_ref.actTicks.back()) < tXAW) { 987 panic("Got %d activates in window %d (%llu - %llu) which " 988 "is smaller than %llu\n", activationLimit, act_tick - 989 rank_ref.actTicks.back(), act_tick, 990 rank_ref.actTicks.back(), tXAW); 991 } 992 993 // shift the times used for the book keeping, the last element 994 // (highest index) is the oldest one and hence the lowest value 995 rank_ref.actTicks.pop_back(); 996 997 // record an new activation (in the future) 998 rank_ref.actTicks.push_front(act_tick); 999 1000 // cannot activate more than X times in time window tXAW, push the 1001 // next one (the X + 1'st activate) to be tXAW away from the 1002 // oldest in our window of X 1003 if (rank_ref.actTicks.back() && 1004 (act_tick - rank_ref.actTicks.back()) < tXAW) { 1005 DPRINTF(DRAM, "Enforcing tXAW with X = %d, next activate " 1006 "no earlier than %llu\n", activationLimit, 1007 rank_ref.actTicks.back() + tXAW); 1008 for (int j = 0; j < banksPerRank; j++) 1009 // next activate must not happen before end of window 1010 rank_ref.banks[j].actAllowedAt = 1011 std::max(rank_ref.actTicks.back() + tXAW, 1012 rank_ref.banks[j].actAllowedAt); 1013 } 1014 } 1015 1016 // at the point when this activate takes place, make sure we 1017 // transition to the active power state 1018 if (!rank_ref.activateEvent.scheduled()) 1019 schedule(rank_ref.activateEvent, act_tick); 1020 else if (rank_ref.activateEvent.when() > act_tick) 1021 // move it sooner in time 1022 reschedule(rank_ref.activateEvent, act_tick); 1023} 1024 1025void 1026DRAMCtrl::prechargeBank(Rank& rank_ref, Bank& bank, Tick pre_at, bool trace) 1027{ 1028 // make sure the bank has an open row 1029 assert(bank.openRow != Bank::NO_ROW); 1030 1031 // sample the bytes per activate here since we are closing 1032 // the page 1033 bytesPerActivate.sample(bank.bytesAccessed); 1034 1035 bank.openRow = Bank::NO_ROW; 1036 1037 // no precharge allowed before this one 1038 bank.preAllowedAt = pre_at; 1039 1040 Tick pre_done_at = pre_at + tRP; 1041 1042 bank.actAllowedAt = std::max(bank.actAllowedAt, pre_done_at); 1043 1044 assert(rank_ref.numBanksActive != 0); 1045 --rank_ref.numBanksActive; 1046 1047 DPRINTF(DRAM, "Precharging bank %d, rank %d at tick %lld, now got " 1048 "%d active\n", bank.bank, rank_ref.rank, pre_at, 1049 rank_ref.numBanksActive); 1050 1051 if (trace) { 1052 1053 rank_ref.cmdList.push_back(Command(MemCommand::PRE, bank.bank, 1054 pre_at)); 1055 DPRINTF(DRAMPower, "%llu,PRE,%d,%d\n", divCeil(pre_at, tCK) - 1056 timeStampOffset, bank.bank, rank_ref.rank); 1057 } 1058 // if we look at the current number of active banks we might be 1059 // tempted to think the DRAM is now idle, however this can be 1060 // undone by an activate that is scheduled to happen before we 1061 // would have reached the idle state, so schedule an event and 1062 // rather check once we actually make it to the point in time when 1063 // the (last) precharge takes place
|
1015 if (!rank_ref.prechargeEvent.scheduled())
| 1064 if (!rank_ref.prechargeEvent.scheduled()) {
|
1016 schedule(rank_ref.prechargeEvent, pre_done_at);
| 1065 schedule(rank_ref.prechargeEvent, pre_done_at);
|
1017 else if (rank_ref.prechargeEvent.when() < pre_done_at)
| 1066 // New event, increment count 1067 ++rank_ref.outstandingEvents; 1068 } else if (rank_ref.prechargeEvent.when() < pre_done_at) {
|
1018 reschedule(rank_ref.prechargeEvent, pre_done_at);
| 1069 reschedule(rank_ref.prechargeEvent, pre_done_at);
|
| 1070 }
|
1019} 1020 1021void 1022DRAMCtrl::doDRAMAccess(DRAMPacket* dram_pkt) 1023{ 1024 DPRINTF(DRAM, "Timing access to addr %lld, rank/bank/row %d %d %d\n", 1025 dram_pkt->addr, dram_pkt->rank, dram_pkt->bank, dram_pkt->row); 1026 1027 // get the rank 1028 Rank& rank = dram_pkt->rankRef; 1029
| 1071} 1072 1073void 1074DRAMCtrl::doDRAMAccess(DRAMPacket* dram_pkt) 1075{ 1076 DPRINTF(DRAM, "Timing access to addr %lld, rank/bank/row %d %d %d\n", 1077 dram_pkt->addr, dram_pkt->rank, dram_pkt->bank, dram_pkt->row); 1078 1079 // get the rank 1080 Rank& rank = dram_pkt->rankRef; 1081
|
| 1082 // are we in or transitioning to a low-power state and have not scheduled 1083 // a power-up event? 1084 // if so, wake up from power down to issue RD/WR burst 1085 if (rank.inLowPowerState) { 1086 assert(rank.pwrState != PWR_SREF); 1087 rank.scheduleWakeUpEvent(tXP); 1088 } 1089
|
1030 // get the bank 1031 Bank& bank = dram_pkt->bankRef; 1032 1033 // for the state we need to track if it is a row hit or not 1034 bool row_hit = true; 1035 1036 // respect any constraints on the command (e.g. tRCD or tCCD) 1037 Tick cmd_at = std::max(bank.colAllowedAt, curTick()); 1038 1039 // Determine the access latency and update the bank state 1040 if (bank.openRow == dram_pkt->row) { 1041 // nothing to do 1042 } else { 1043 row_hit = false; 1044 1045 // If there is a page open, precharge it. 1046 if (bank.openRow != Bank::NO_ROW) { 1047 prechargeBank(rank, bank, std::max(bank.preAllowedAt, curTick())); 1048 } 1049 1050 // next we need to account for the delay in activating the 1051 // page 1052 Tick act_tick = std::max(bank.actAllowedAt, curTick()); 1053 1054 // Record the activation and deal with all the global timing 1055 // constraints caused be a new activation (tRRD and tXAW) 1056 activateBank(rank, bank, act_tick, dram_pkt->row); 1057 1058 // issue the command as early as possible 1059 cmd_at = bank.colAllowedAt; 1060 } 1061 1062 // we need to wait until the bus is available before we can issue 1063 // the command 1064 cmd_at = std::max(cmd_at, busBusyUntil - tCL); 1065 1066 // update the packet ready time 1067 dram_pkt->readyTime = cmd_at + tCL + tBURST; 1068 1069 // only one burst can use the bus at any one point in time 1070 assert(dram_pkt->readyTime - busBusyUntil >= tBURST); 1071 1072 // update the time for the next read/write burst for each 1073 // bank (add a max with tCCD/tCCD_L here) 1074 Tick cmd_dly; 1075 for (int j = 0; j < ranksPerChannel; j++) { 1076 for (int i = 0; i < banksPerRank; i++) { 1077 // next burst to same bank group in this rank must not happen 1078 // before tCCD_L. Different bank group timing requirement is 1079 // tBURST; Add tCS for different ranks 1080 if (dram_pkt->rank == j) { 1081 if (bankGroupArch && 1082 (bank.bankgr == ranks[j]->banks[i].bankgr)) { 1083 // bank group architecture requires longer delays between 1084 // RD/WR burst commands to the same bank group. 1085 // Use tCCD_L in this case 1086 cmd_dly = tCCD_L; 1087 } else { 1088 // use tBURST (equivalent to tCCD_S), the shorter 1089 // cas-to-cas delay value, when either: 1090 // 1) bank group architecture is not supportted 1091 // 2) bank is in a different bank group 1092 cmd_dly = tBURST; 1093 } 1094 } else { 1095 // different rank is by default in a different bank group 1096 // use tBURST (equivalent to tCCD_S), which is the shorter 1097 // cas-to-cas delay in this case 1098 // Add tCS to account for rank-to-rank bus delay requirements 1099 cmd_dly = tBURST + tCS; 1100 } 1101 ranks[j]->banks[i].colAllowedAt = std::max(cmd_at + cmd_dly, 1102 ranks[j]->banks[i].colAllowedAt); 1103 } 1104 } 1105 1106 // Save rank of current access 1107 activeRank = dram_pkt->rank; 1108 1109 // If this is a write, we also need to respect the write recovery 1110 // time before a precharge, in the case of a read, respect the 1111 // read to precharge constraint 1112 bank.preAllowedAt = std::max(bank.preAllowedAt, 1113 dram_pkt->isRead ? cmd_at + tRTP : 1114 dram_pkt->readyTime + tWR); 1115 1116 // increment the bytes accessed and the accesses per row 1117 bank.bytesAccessed += burstSize; 1118 ++bank.rowAccesses; 1119 1120 // if we reached the max, then issue with an auto-precharge 1121 bool auto_precharge = pageMgmt == Enums::close || 1122 bank.rowAccesses == maxAccessesPerRow; 1123 1124 // if we did not hit the limit, we might still want to 1125 // auto-precharge 1126 if (!auto_precharge && 1127 (pageMgmt == Enums::open_adaptive || 1128 pageMgmt == Enums::close_adaptive)) { 1129 // a twist on the open and close page policies: 1130 // 1) open_adaptive page policy does not blindly keep the 1131 // page open, but close it if there are no row hits, and there 1132 // are bank conflicts in the queue 1133 // 2) close_adaptive page policy does not blindly close the 1134 // page, but closes it only if there are no row hits in the queue. 1135 // In this case, only force an auto precharge when there 1136 // are no same page hits in the queue 1137 bool got_more_hits = false; 1138 bool got_bank_conflict = false; 1139 1140 // either look at the read queue or write queue 1141 const deque<DRAMPacket*>& queue = dram_pkt->isRead ? readQueue : 1142 writeQueue; 1143 auto p = queue.begin(); 1144 // make sure we are not considering the packet that we are 1145 // currently dealing with (which is the head of the queue) 1146 ++p; 1147 1148 // keep on looking until we find a hit or reach the end of the queue 1149 // 1) if a hit is found, then both open and close adaptive policies keep 1150 // the page open 1151 // 2) if no hit is found, got_bank_conflict is set to true if a bank 1152 // conflict request is waiting in the queue 1153 while (!got_more_hits && p != queue.end()) { 1154 bool same_rank_bank = (dram_pkt->rank == (*p)->rank) && 1155 (dram_pkt->bank == (*p)->bank); 1156 bool same_row = dram_pkt->row == (*p)->row; 1157 got_more_hits |= same_rank_bank && same_row; 1158 got_bank_conflict |= same_rank_bank && !same_row; 1159 ++p; 1160 } 1161 1162 // auto pre-charge when either 1163 // 1) open_adaptive policy, we have not got any more hits, and 1164 // have a bank conflict 1165 // 2) close_adaptive policy and we have not got any more hits 1166 auto_precharge = !got_more_hits && 1167 (got_bank_conflict || pageMgmt == Enums::close_adaptive); 1168 } 1169 1170 // DRAMPower trace command to be written 1171 std::string mem_cmd = dram_pkt->isRead ? "RD" : "WR"; 1172 1173 // MemCommand required for DRAMPower library 1174 MemCommand::cmds command = (mem_cmd == "RD") ? MemCommand::RD : 1175 MemCommand::WR; 1176 1177 // Update bus state 1178 busBusyUntil = dram_pkt->readyTime; 1179 1180 DPRINTF(DRAM, "Access to %lld, ready at %lld bus busy until %lld.\n", 1181 dram_pkt->addr, dram_pkt->readyTime, busBusyUntil); 1182 1183 dram_pkt->rankRef.cmdList.push_back(Command(command, dram_pkt->bank, 1184 cmd_at)); 1185 1186 DPRINTF(DRAMPower, "%llu,%s,%d,%d\n", divCeil(cmd_at, tCK) - 1187 timeStampOffset, mem_cmd, dram_pkt->bank, dram_pkt->rank); 1188 1189 // if this access should use auto-precharge, then we are 1190 // closing the row after the read/write burst 1191 if (auto_precharge) { 1192 // if auto-precharge push a PRE command at the correct tick to the 1193 // list used by DRAMPower library to calculate power 1194 prechargeBank(rank, bank, std::max(curTick(), bank.preAllowedAt)); 1195 1196 DPRINTF(DRAM, "Auto-precharged bank: %d\n", dram_pkt->bankId); 1197 } 1198 1199 // Update the minimum timing between the requests, this is a 1200 // conservative estimate of when we have to schedule the next 1201 // request to not introduce any unecessary bubbles. In most cases 1202 // we will wake up sooner than we have to. 1203 nextReqTime = busBusyUntil - (tRP + tRCD + tCL); 1204 1205 // Update the stats and schedule the next request 1206 if (dram_pkt->isRead) { 1207 ++readsThisTime; 1208 if (row_hit) 1209 readRowHits++; 1210 bytesReadDRAM += burstSize; 1211 perBankRdBursts[dram_pkt->bankId]++; 1212 1213 // Update latency stats 1214 totMemAccLat += dram_pkt->readyTime - dram_pkt->entryTime; 1215 totBusLat += tBURST; 1216 totQLat += cmd_at - dram_pkt->entryTime; 1217 } else { 1218 ++writesThisTime; 1219 if (row_hit) 1220 writeRowHits++; 1221 bytesWritten += burstSize; 1222 perBankWrBursts[dram_pkt->bankId]++; 1223 } 1224} 1225 1226void 1227DRAMCtrl::processNextReqEvent() 1228{ 1229 int busyRanks = 0; 1230 for (auto r : ranks) { 1231 if (!r->isAvailable()) {
| 1090 // get the bank 1091 Bank& bank = dram_pkt->bankRef; 1092 1093 // for the state we need to track if it is a row hit or not 1094 bool row_hit = true; 1095 1096 // respect any constraints on the command (e.g. tRCD or tCCD) 1097 Tick cmd_at = std::max(bank.colAllowedAt, curTick()); 1098 1099 // Determine the access latency and update the bank state 1100 if (bank.openRow == dram_pkt->row) { 1101 // nothing to do 1102 } else { 1103 row_hit = false; 1104 1105 // If there is a page open, precharge it. 1106 if (bank.openRow != Bank::NO_ROW) { 1107 prechargeBank(rank, bank, std::max(bank.preAllowedAt, curTick())); 1108 } 1109 1110 // next we need to account for the delay in activating the 1111 // page 1112 Tick act_tick = std::max(bank.actAllowedAt, curTick()); 1113 1114 // Record the activation and deal with all the global timing 1115 // constraints caused be a new activation (tRRD and tXAW) 1116 activateBank(rank, bank, act_tick, dram_pkt->row); 1117 1118 // issue the command as early as possible 1119 cmd_at = bank.colAllowedAt; 1120 } 1121 1122 // we need to wait until the bus is available before we can issue 1123 // the command 1124 cmd_at = std::max(cmd_at, busBusyUntil - tCL); 1125 1126 // update the packet ready time 1127 dram_pkt->readyTime = cmd_at + tCL + tBURST; 1128 1129 // only one burst can use the bus at any one point in time 1130 assert(dram_pkt->readyTime - busBusyUntil >= tBURST); 1131 1132 // update the time for the next read/write burst for each 1133 // bank (add a max with tCCD/tCCD_L here) 1134 Tick cmd_dly; 1135 for (int j = 0; j < ranksPerChannel; j++) { 1136 for (int i = 0; i < banksPerRank; i++) { 1137 // next burst to same bank group in this rank must not happen 1138 // before tCCD_L. Different bank group timing requirement is 1139 // tBURST; Add tCS for different ranks 1140 if (dram_pkt->rank == j) { 1141 if (bankGroupArch && 1142 (bank.bankgr == ranks[j]->banks[i].bankgr)) { 1143 // bank group architecture requires longer delays between 1144 // RD/WR burst commands to the same bank group. 1145 // Use tCCD_L in this case 1146 cmd_dly = tCCD_L; 1147 } else { 1148 // use tBURST (equivalent to tCCD_S), the shorter 1149 // cas-to-cas delay value, when either: 1150 // 1) bank group architecture is not supportted 1151 // 2) bank is in a different bank group 1152 cmd_dly = tBURST; 1153 } 1154 } else { 1155 // different rank is by default in a different bank group 1156 // use tBURST (equivalent to tCCD_S), which is the shorter 1157 // cas-to-cas delay in this case 1158 // Add tCS to account for rank-to-rank bus delay requirements 1159 cmd_dly = tBURST + tCS; 1160 } 1161 ranks[j]->banks[i].colAllowedAt = std::max(cmd_at + cmd_dly, 1162 ranks[j]->banks[i].colAllowedAt); 1163 } 1164 } 1165 1166 // Save rank of current access 1167 activeRank = dram_pkt->rank; 1168 1169 // If this is a write, we also need to respect the write recovery 1170 // time before a precharge, in the case of a read, respect the 1171 // read to precharge constraint 1172 bank.preAllowedAt = std::max(bank.preAllowedAt, 1173 dram_pkt->isRead ? cmd_at + tRTP : 1174 dram_pkt->readyTime + tWR); 1175 1176 // increment the bytes accessed and the accesses per row 1177 bank.bytesAccessed += burstSize; 1178 ++bank.rowAccesses; 1179 1180 // if we reached the max, then issue with an auto-precharge 1181 bool auto_precharge = pageMgmt == Enums::close || 1182 bank.rowAccesses == maxAccessesPerRow; 1183 1184 // if we did not hit the limit, we might still want to 1185 // auto-precharge 1186 if (!auto_precharge && 1187 (pageMgmt == Enums::open_adaptive || 1188 pageMgmt == Enums::close_adaptive)) { 1189 // a twist on the open and close page policies: 1190 // 1) open_adaptive page policy does not blindly keep the 1191 // page open, but close it if there are no row hits, and there 1192 // are bank conflicts in the queue 1193 // 2) close_adaptive page policy does not blindly close the 1194 // page, but closes it only if there are no row hits in the queue. 1195 // In this case, only force an auto precharge when there 1196 // are no same page hits in the queue 1197 bool got_more_hits = false; 1198 bool got_bank_conflict = false; 1199 1200 // either look at the read queue or write queue 1201 const deque<DRAMPacket*>& queue = dram_pkt->isRead ? readQueue : 1202 writeQueue; 1203 auto p = queue.begin(); 1204 // make sure we are not considering the packet that we are 1205 // currently dealing with (which is the head of the queue) 1206 ++p; 1207 1208 // keep on looking until we find a hit or reach the end of the queue 1209 // 1) if a hit is found, then both open and close adaptive policies keep 1210 // the page open 1211 // 2) if no hit is found, got_bank_conflict is set to true if a bank 1212 // conflict request is waiting in the queue 1213 while (!got_more_hits && p != queue.end()) { 1214 bool same_rank_bank = (dram_pkt->rank == (*p)->rank) && 1215 (dram_pkt->bank == (*p)->bank); 1216 bool same_row = dram_pkt->row == (*p)->row; 1217 got_more_hits |= same_rank_bank && same_row; 1218 got_bank_conflict |= same_rank_bank && !same_row; 1219 ++p; 1220 } 1221 1222 // auto pre-charge when either 1223 // 1) open_adaptive policy, we have not got any more hits, and 1224 // have a bank conflict 1225 // 2) close_adaptive policy and we have not got any more hits 1226 auto_precharge = !got_more_hits && 1227 (got_bank_conflict || pageMgmt == Enums::close_adaptive); 1228 } 1229 1230 // DRAMPower trace command to be written 1231 std::string mem_cmd = dram_pkt->isRead ? "RD" : "WR"; 1232 1233 // MemCommand required for DRAMPower library 1234 MemCommand::cmds command = (mem_cmd == "RD") ? MemCommand::RD : 1235 MemCommand::WR; 1236 1237 // Update bus state 1238 busBusyUntil = dram_pkt->readyTime; 1239 1240 DPRINTF(DRAM, "Access to %lld, ready at %lld bus busy until %lld.\n", 1241 dram_pkt->addr, dram_pkt->readyTime, busBusyUntil); 1242 1243 dram_pkt->rankRef.cmdList.push_back(Command(command, dram_pkt->bank, 1244 cmd_at)); 1245 1246 DPRINTF(DRAMPower, "%llu,%s,%d,%d\n", divCeil(cmd_at, tCK) - 1247 timeStampOffset, mem_cmd, dram_pkt->bank, dram_pkt->rank); 1248 1249 // if this access should use auto-precharge, then we are 1250 // closing the row after the read/write burst 1251 if (auto_precharge) { 1252 // if auto-precharge push a PRE command at the correct tick to the 1253 // list used by DRAMPower library to calculate power 1254 prechargeBank(rank, bank, std::max(curTick(), bank.preAllowedAt)); 1255 1256 DPRINTF(DRAM, "Auto-precharged bank: %d\n", dram_pkt->bankId); 1257 } 1258 1259 // Update the minimum timing between the requests, this is a 1260 // conservative estimate of when we have to schedule the next 1261 // request to not introduce any unecessary bubbles. In most cases 1262 // we will wake up sooner than we have to. 1263 nextReqTime = busBusyUntil - (tRP + tRCD + tCL); 1264 1265 // Update the stats and schedule the next request 1266 if (dram_pkt->isRead) { 1267 ++readsThisTime; 1268 if (row_hit) 1269 readRowHits++; 1270 bytesReadDRAM += burstSize; 1271 perBankRdBursts[dram_pkt->bankId]++; 1272 1273 // Update latency stats 1274 totMemAccLat += dram_pkt->readyTime - dram_pkt->entryTime; 1275 totBusLat += tBURST; 1276 totQLat += cmd_at - dram_pkt->entryTime; 1277 } else { 1278 ++writesThisTime; 1279 if (row_hit) 1280 writeRowHits++; 1281 bytesWritten += burstSize; 1282 perBankWrBursts[dram_pkt->bankId]++; 1283 } 1284} 1285 1286void 1287DRAMCtrl::processNextReqEvent() 1288{ 1289 int busyRanks = 0; 1290 for (auto r : ranks) { 1291 if (!r->isAvailable()) {
|
1232 // rank is busy refreshing 1233 busyRanks++;
| 1292 if (r->pwrState != PWR_SREF) { 1293 // rank is busy refreshing 1294 DPRINTF(DRAMState, "Rank %d is not available\n", r->rank); 1295 busyRanks++;
|
1234
| 1296
|
1235 // let the rank know that if it was waiting to drain, it 1236 // is now done and ready to proceed 1237 r->checkDrainDone();
| 1297 // let the rank know that if it was waiting to drain, it 1298 // is now done and ready to proceed 1299 r->checkDrainDone(); 1300 } 1301 1302 // check if we were in self-refresh and haven't started 1303 // to transition out 1304 if ((r->pwrState == PWR_SREF) && r->inLowPowerState) { 1305 DPRINTF(DRAMState, "Rank %d is in self-refresh\n", r->rank); 1306 // if we have commands queued to this rank and we don't have 1307 // a minimum number of active commands enqueued, 1308 // exit self-refresh 1309 if (r->forceSelfRefreshExit()) { 1310 DPRINTF(DRAMState, "rank %d was in self refresh and" 1311 " should wake up\n", r->rank); 1312 //wake up from self-refresh 1313 r->scheduleWakeUpEvent(tXS); 1314 // things are brought back into action once a refresh is 1315 // performed after self-refresh 1316 // continue with selection for other ranks 1317 } 1318 }
|
1238 } 1239 } 1240 1241 if (busyRanks == ranksPerChannel) { 1242 // if all ranks are refreshing wait for them to finish 1243 // and stall this state machine without taking any further 1244 // action, and do not schedule a new nextReqEvent 1245 return; 1246 } 1247
| 1319 } 1320 } 1321 1322 if (busyRanks == ranksPerChannel) { 1323 // if all ranks are refreshing wait for them to finish 1324 // and stall this state machine without taking any further 1325 // action, and do not schedule a new nextReqEvent 1326 return; 1327 } 1328
|
1248 // pre-emptively set to false. Overwrite if in READ_TO_WRITE 1249 // or WRITE_TO_READ state
| 1329 // pre-emptively set to false. Overwrite if in transitioning to 1330 // a new state
|
1250 bool switched_cmd_type = false;
| 1331 bool switched_cmd_type = false;
|
1251 if (busState == READ_TO_WRITE) { 1252 DPRINTF(DRAM, "Switching to writes after %d reads with %d reads " 1253 "waiting\n", readsThisTime, readQueue.size());
| 1332 if (busState != busStateNext) { 1333 if (busState == READ) { 1334 DPRINTF(DRAM, "Switching to writes after %d reads with %d reads " 1335 "waiting\n", readsThisTime, readQueue.size());
|
1254
| 1336
|
1255 // sample and reset the read-related stats as we are now 1256 // transitioning to writes, and all reads are done 1257 rdPerTurnAround.sample(readsThisTime); 1258 readsThisTime = 0;
| 1337 // sample and reset the read-related stats as we are now 1338 // transitioning to writes, and all reads are done 1339 rdPerTurnAround.sample(readsThisTime); 1340 readsThisTime = 0;
|
1259
| 1341
|
1260 // now proceed to do the actual writes 1261 busState = WRITE; 1262 switched_cmd_type = true; 1263 } else if (busState == WRITE_TO_READ) { 1264 DPRINTF(DRAM, "Switching to reads after %d writes with %d writes " 1265 "waiting\n", writesThisTime, writeQueue.size());
| 1342 // now proceed to do the actual writes 1343 switched_cmd_type = true; 1344 } else { 1345 DPRINTF(DRAM, "Switching to reads after %d writes with %d writes " 1346 "waiting\n", writesThisTime, writeQueue.size());
|
1266
| 1347
|
1267 wrPerTurnAround.sample(writesThisTime); 1268 writesThisTime = 0;
| 1348 wrPerTurnAround.sample(writesThisTime); 1349 writesThisTime = 0;
|
1269
| 1350
|
1270 busState = READ; 1271 switched_cmd_type = true;
| 1351 switched_cmd_type = true; 1352 } 1353 // update busState to match next state until next transition 1354 busState = busStateNext;
|
1272 } 1273 1274 // when we get here it is either a read or a write 1275 if (busState == READ) { 1276 1277 // track if we should switch or not 1278 bool switch_to_writes = false; 1279 1280 if (readQueue.empty()) { 1281 // In the case there is no read request to go next, 1282 // trigger writes if we have passed the low threshold (or 1283 // if we are draining) 1284 if (!writeQueue.empty() && 1285 (drainState() == DrainState::Draining || 1286 writeQueue.size() > writeLowThreshold)) { 1287 1288 switch_to_writes = true; 1289 } else { 1290 // check if we are drained 1291 // not done draining until in PWR_IDLE state 1292 // ensuring all banks are closed and 1293 // have exited low power states 1294 if (drainState() == DrainState::Draining && 1295 respQueue.empty() && allRanksDrained()) { 1296 1297 DPRINTF(Drain, "DRAM controller done draining\n"); 1298 signalDrainDone(); 1299 } 1300 1301 // nothing to do, not even any point in scheduling an 1302 // event for the next request 1303 return; 1304 } 1305 } else { 1306 // bool to check if there is a read to a free rank 1307 bool found_read = false; 1308 1309 // Figure out which read request goes next, and move it to the 1310 // front of the read queue 1311 // If we are changing command type, incorporate the minimum 1312 // bus turnaround delay which will be tCS (different rank) case 1313 found_read = chooseNext(readQueue, 1314 switched_cmd_type ? tCS : 0); 1315 1316 // if no read to an available rank is found then return 1317 // at this point. There could be writes to the available ranks 1318 // which are above the required threshold. However, to 1319 // avoid adding more complexity to the code, return and wait 1320 // for a refresh event to kick things into action again. 1321 if (!found_read) 1322 return; 1323 1324 DRAMPacket* dram_pkt = readQueue.front(); 1325 assert(dram_pkt->rankRef.isAvailable());
| 1355 } 1356 1357 // when we get here it is either a read or a write 1358 if (busState == READ) { 1359 1360 // track if we should switch or not 1361 bool switch_to_writes = false; 1362 1363 if (readQueue.empty()) { 1364 // In the case there is no read request to go next, 1365 // trigger writes if we have passed the low threshold (or 1366 // if we are draining) 1367 if (!writeQueue.empty() && 1368 (drainState() == DrainState::Draining || 1369 writeQueue.size() > writeLowThreshold)) { 1370 1371 switch_to_writes = true; 1372 } else { 1373 // check if we are drained 1374 // not done draining until in PWR_IDLE state 1375 // ensuring all banks are closed and 1376 // have exited low power states 1377 if (drainState() == DrainState::Draining && 1378 respQueue.empty() && allRanksDrained()) { 1379 1380 DPRINTF(Drain, "DRAM controller done draining\n"); 1381 signalDrainDone(); 1382 } 1383 1384 // nothing to do, not even any point in scheduling an 1385 // event for the next request 1386 return; 1387 } 1388 } else { 1389 // bool to check if there is a read to a free rank 1390 bool found_read = false; 1391 1392 // Figure out which read request goes next, and move it to the 1393 // front of the read queue 1394 // If we are changing command type, incorporate the minimum 1395 // bus turnaround delay which will be tCS (different rank) case 1396 found_read = chooseNext(readQueue, 1397 switched_cmd_type ? tCS : 0); 1398 1399 // if no read to an available rank is found then return 1400 // at this point. There could be writes to the available ranks 1401 // which are above the required threshold. However, to 1402 // avoid adding more complexity to the code, return and wait 1403 // for a refresh event to kick things into action again. 1404 if (!found_read) 1405 return; 1406 1407 DRAMPacket* dram_pkt = readQueue.front(); 1408 assert(dram_pkt->rankRef.isAvailable());
|
| 1409
|
1326 // here we get a bit creative and shift the bus busy time not 1327 // just the tWTR, but also a CAS latency to capture the fact 1328 // that we are allowed to prepare a new bank, but not issue a 1329 // read command until after tWTR, in essence we capture a 1330 // bubble on the data bus that is tWTR + tCL 1331 if (switched_cmd_type && dram_pkt->rank == activeRank) { 1332 busBusyUntil += tWTR + tCL; 1333 } 1334 1335 doDRAMAccess(dram_pkt); 1336 1337 // At this point we're done dealing with the request 1338 readQueue.pop_front(); 1339
| 1410 // here we get a bit creative and shift the bus busy time not 1411 // just the tWTR, but also a CAS latency to capture the fact 1412 // that we are allowed to prepare a new bank, but not issue a 1413 // read command until after tWTR, in essence we capture a 1414 // bubble on the data bus that is tWTR + tCL 1415 if (switched_cmd_type && dram_pkt->rank == activeRank) { 1416 busBusyUntil += tWTR + tCL; 1417 } 1418 1419 doDRAMAccess(dram_pkt); 1420 1421 // At this point we're done dealing with the request 1422 readQueue.pop_front(); 1423
|
| 1424 // Every respQueue which will generate an event, increment count 1425 ++dram_pkt->rankRef.outstandingEvents; 1426
|
1340 // sanity check 1341 assert(dram_pkt->size <= burstSize); 1342 assert(dram_pkt->readyTime >= curTick()); 1343 1344 // Insert into response queue. It will be sent back to the 1345 // requestor at its readyTime 1346 if (respQueue.empty()) { 1347 assert(!respondEvent.scheduled()); 1348 schedule(respondEvent, dram_pkt->readyTime); 1349 } else { 1350 assert(respQueue.back()->readyTime <= dram_pkt->readyTime); 1351 assert(respondEvent.scheduled()); 1352 } 1353 1354 respQueue.push_back(dram_pkt); 1355 1356 // we have so many writes that we have to transition 1357 if (writeQueue.size() > writeHighThreshold) { 1358 switch_to_writes = true; 1359 } 1360 } 1361 1362 // switching to writes, either because the read queue is empty 1363 // and the writes have passed the low threshold (or we are 1364 // draining), or because the writes hit the hight threshold 1365 if (switch_to_writes) { 1366 // transition to writing
| 1427 // sanity check 1428 assert(dram_pkt->size <= burstSize); 1429 assert(dram_pkt->readyTime >= curTick()); 1430 1431 // Insert into response queue. It will be sent back to the 1432 // requestor at its readyTime 1433 if (respQueue.empty()) { 1434 assert(!respondEvent.scheduled()); 1435 schedule(respondEvent, dram_pkt->readyTime); 1436 } else { 1437 assert(respQueue.back()->readyTime <= dram_pkt->readyTime); 1438 assert(respondEvent.scheduled()); 1439 } 1440 1441 respQueue.push_back(dram_pkt); 1442 1443 // we have so many writes that we have to transition 1444 if (writeQueue.size() > writeHighThreshold) { 1445 switch_to_writes = true; 1446 } 1447 } 1448 1449 // switching to writes, either because the read queue is empty 1450 // and the writes have passed the low threshold (or we are 1451 // draining), or because the writes hit the hight threshold 1452 if (switch_to_writes) { 1453 // transition to writing
|
1367 busState = READ_TO_WRITE;
| 1454 busStateNext = WRITE;
|
1368 } 1369 } else { 1370 // bool to check if write to free rank is found 1371 bool found_write = false; 1372 1373 // If we are changing command type, incorporate the minimum 1374 // bus turnaround delay 1375 found_write = chooseNext(writeQueue, 1376 switched_cmd_type ? std::min(tRTW, tCS) : 0); 1377 1378 // if no writes to an available rank are found then return. 1379 // There could be reads to the available ranks. However, to avoid 1380 // adding more complexity to the code, return at this point and wait 1381 // for a refresh event to kick things into action again. 1382 if (!found_write) 1383 return; 1384 1385 DRAMPacket* dram_pkt = writeQueue.front(); 1386 assert(dram_pkt->rankRef.isAvailable()); 1387 // sanity check 1388 assert(dram_pkt->size <= burstSize); 1389 1390 // add a bubble to the data bus, as defined by the 1391 // tRTW when access is to the same rank as previous burst 1392 // Different rank timing is handled with tCS, which is 1393 // applied to colAllowedAt 1394 if (switched_cmd_type && dram_pkt->rank == activeRank) { 1395 busBusyUntil += tRTW; 1396 } 1397 1398 doDRAMAccess(dram_pkt); 1399 1400 writeQueue.pop_front();
| 1455 } 1456 } else { 1457 // bool to check if write to free rank is found 1458 bool found_write = false; 1459 1460 // If we are changing command type, incorporate the minimum 1461 // bus turnaround delay 1462 found_write = chooseNext(writeQueue, 1463 switched_cmd_type ? std::min(tRTW, tCS) : 0); 1464 1465 // if no writes to an available rank are found then return. 1466 // There could be reads to the available ranks. However, to avoid 1467 // adding more complexity to the code, return at this point and wait 1468 // for a refresh event to kick things into action again. 1469 if (!found_write) 1470 return; 1471 1472 DRAMPacket* dram_pkt = writeQueue.front(); 1473 assert(dram_pkt->rankRef.isAvailable()); 1474 // sanity check 1475 assert(dram_pkt->size <= burstSize); 1476 1477 // add a bubble to the data bus, as defined by the 1478 // tRTW when access is to the same rank as previous burst 1479 // Different rank timing is handled with tCS, which is 1480 // applied to colAllowedAt 1481 if (switched_cmd_type && dram_pkt->rank == activeRank) { 1482 busBusyUntil += tRTW; 1483 } 1484 1485 doDRAMAccess(dram_pkt); 1486 1487 writeQueue.pop_front();
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| 1488 1489 // removed write from queue, decrement count 1490 --dram_pkt->rankRef.writeEntries; 1491 1492 // Schedule write done event to decrement event count 1493 // after the readyTime has been reached 1494 // Only schedule latest write event to minimize events 1495 // required; only need to ensure that final event scheduled covers 1496 // the time that writes are outstanding and bus is active 1497 // to holdoff power-down entry events 1498 if (!dram_pkt->rankRef.writeDoneEvent.scheduled()) { 1499 schedule(dram_pkt->rankRef.writeDoneEvent, dram_pkt->readyTime); 1500 // New event, increment count 1501 ++dram_pkt->rankRef.outstandingEvents; 1502 1503 } else if (dram_pkt->rankRef.writeDoneEvent.when() < 1504 dram_pkt-> readyTime) { 1505 reschedule(dram_pkt->rankRef.writeDoneEvent, dram_pkt->readyTime); 1506 } 1507
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1401 isInWriteQueue.erase(burstAlign(dram_pkt->addr)); 1402 delete dram_pkt; 1403 1404 // If we emptied the write queue, or got sufficiently below the 1405 // threshold (using the minWritesPerSwitch as the hysteresis) and 1406 // are not draining, or we have reads waiting and have done enough 1407 // writes, then switch to reads. 1408 if (writeQueue.empty() || 1409 (writeQueue.size() + minWritesPerSwitch < writeLowThreshold && 1410 drainState() != DrainState::Draining) || 1411 (!readQueue.empty() && writesThisTime >= minWritesPerSwitch)) { 1412 // turn the bus back around for reads again
| 1508 isInWriteQueue.erase(burstAlign(dram_pkt->addr)); 1509 delete dram_pkt; 1510 1511 // If we emptied the write queue, or got sufficiently below the 1512 // threshold (using the minWritesPerSwitch as the hysteresis) and 1513 // are not draining, or we have reads waiting and have done enough 1514 // writes, then switch to reads. 1515 if (writeQueue.empty() || 1516 (writeQueue.size() + minWritesPerSwitch < writeLowThreshold && 1517 drainState() != DrainState::Draining) || 1518 (!readQueue.empty() && writesThisTime >= minWritesPerSwitch)) { 1519 // turn the bus back around for reads again
|
1413 busState = WRITE_TO_READ;
| 1520 busStateNext = READ;
|
1414 1415 // note that the we switch back to reads also in the idle 1416 // case, which eventually will check for any draining and 1417 // also pause any further scheduling if there is really 1418 // nothing to do 1419 } 1420 } 1421 // It is possible that a refresh to another rank kicks things back into 1422 // action before reaching this point. 1423 if (!nextReqEvent.scheduled()) 1424 schedule(nextReqEvent, std::max(nextReqTime, curTick())); 1425 1426 // If there is space available and we have writes waiting then let 1427 // them retry. This is done here to ensure that the retry does not 1428 // cause a nextReqEvent to be scheduled before we do so as part of 1429 // the next request processing 1430 if (retryWrReq && writeQueue.size() < writeBufferSize) { 1431 retryWrReq = false; 1432 port.sendRetryReq(); 1433 } 1434} 1435 1436pair<uint64_t, bool> 1437DRAMCtrl::minBankPrep(const deque<DRAMPacket*>& queue, 1438 Tick min_col_at) const 1439{ 1440 uint64_t bank_mask = 0; 1441 Tick min_act_at = MaxTick; 1442 1443 // latest Tick for which ACT can occur without incurring additoinal 1444 // delay on the data bus 1445 const Tick hidden_act_max = std::max(min_col_at - tRCD, curTick()); 1446 1447 // Flag condition when burst can issue back-to-back with previous burst 1448 bool found_seamless_bank = false; 1449 1450 // Flag condition when bank can be opened without incurring additional 1451 // delay on the data bus 1452 bool hidden_bank_prep = false; 1453 1454 // determine if we have queued transactions targetting the 1455 // bank in question 1456 vector<bool> got_waiting(ranksPerChannel * banksPerRank, false); 1457 for (const auto& p : queue) { 1458 if (p->rankRef.isAvailable()) 1459 got_waiting[p->bankId] = true; 1460 } 1461 1462 // Find command with optimal bank timing 1463 // Will prioritize commands that can issue seamlessly. 1464 for (int i = 0; i < ranksPerChannel; i++) { 1465 for (int j = 0; j < banksPerRank; j++) { 1466 uint16_t bank_id = i * banksPerRank + j; 1467 1468 // if we have waiting requests for the bank, and it is 1469 // amongst the first available, update the mask 1470 if (got_waiting[bank_id]) { 1471 // make sure this rank is not currently refreshing. 1472 assert(ranks[i]->isAvailable()); 1473 // simplistic approximation of when the bank can issue 1474 // an activate, ignoring any rank-to-rank switching 1475 // cost in this calculation 1476 Tick act_at = ranks[i]->banks[j].openRow == Bank::NO_ROW ? 1477 std::max(ranks[i]->banks[j].actAllowedAt, curTick()) : 1478 std::max(ranks[i]->banks[j].preAllowedAt, curTick()) + tRP; 1479 1480 // When is the earliest the R/W burst can issue? 1481 Tick col_at = std::max(ranks[i]->banks[j].colAllowedAt, 1482 act_at + tRCD); 1483 1484 // bank can issue burst back-to-back (seamlessly) with 1485 // previous burst 1486 bool new_seamless_bank = col_at <= min_col_at; 1487 1488 // if we found a new seamless bank or we have no 1489 // seamless banks, and got a bank with an earlier 1490 // activate time, it should be added to the bit mask 1491 if (new_seamless_bank || 1492 (!found_seamless_bank && act_at <= min_act_at)) { 1493 // if we did not have a seamless bank before, and 1494 // we do now, reset the bank mask, also reset it 1495 // if we have not yet found a seamless bank and 1496 // the activate time is smaller than what we have 1497 // seen so far 1498 if (!found_seamless_bank && 1499 (new_seamless_bank || act_at < min_act_at)) { 1500 bank_mask = 0; 1501 } 1502 1503 found_seamless_bank |= new_seamless_bank; 1504 1505 // ACT can occur 'behind the scenes' 1506 hidden_bank_prep = act_at <= hidden_act_max; 1507 1508 // set the bit corresponding to the available bank 1509 replaceBits(bank_mask, bank_id, bank_id, 1); 1510 min_act_at = act_at; 1511 } 1512 } 1513 } 1514 } 1515 1516 return make_pair(bank_mask, hidden_bank_prep); 1517} 1518 1519DRAMCtrl::Rank::Rank(DRAMCtrl& _memory, const DRAMCtrlParams* _p) 1520 : EventManager(&_memory), memory(_memory),
| 1521 1522 // note that the we switch back to reads also in the idle 1523 // case, which eventually will check for any draining and 1524 // also pause any further scheduling if there is really 1525 // nothing to do 1526 } 1527 } 1528 // It is possible that a refresh to another rank kicks things back into 1529 // action before reaching this point. 1530 if (!nextReqEvent.scheduled()) 1531 schedule(nextReqEvent, std::max(nextReqTime, curTick())); 1532 1533 // If there is space available and we have writes waiting then let 1534 // them retry. This is done here to ensure that the retry does not 1535 // cause a nextReqEvent to be scheduled before we do so as part of 1536 // the next request processing 1537 if (retryWrReq && writeQueue.size() < writeBufferSize) { 1538 retryWrReq = false; 1539 port.sendRetryReq(); 1540 } 1541} 1542 1543pair<uint64_t, bool> 1544DRAMCtrl::minBankPrep(const deque<DRAMPacket*>& queue, 1545 Tick min_col_at) const 1546{ 1547 uint64_t bank_mask = 0; 1548 Tick min_act_at = MaxTick; 1549 1550 // latest Tick for which ACT can occur without incurring additoinal 1551 // delay on the data bus 1552 const Tick hidden_act_max = std::max(min_col_at - tRCD, curTick()); 1553 1554 // Flag condition when burst can issue back-to-back with previous burst 1555 bool found_seamless_bank = false; 1556 1557 // Flag condition when bank can be opened without incurring additional 1558 // delay on the data bus 1559 bool hidden_bank_prep = false; 1560 1561 // determine if we have queued transactions targetting the 1562 // bank in question 1563 vector<bool> got_waiting(ranksPerChannel * banksPerRank, false); 1564 for (const auto& p : queue) { 1565 if (p->rankRef.isAvailable()) 1566 got_waiting[p->bankId] = true; 1567 } 1568 1569 // Find command with optimal bank timing 1570 // Will prioritize commands that can issue seamlessly. 1571 for (int i = 0; i < ranksPerChannel; i++) { 1572 for (int j = 0; j < banksPerRank; j++) { 1573 uint16_t bank_id = i * banksPerRank + j; 1574 1575 // if we have waiting requests for the bank, and it is 1576 // amongst the first available, update the mask 1577 if (got_waiting[bank_id]) { 1578 // make sure this rank is not currently refreshing. 1579 assert(ranks[i]->isAvailable()); 1580 // simplistic approximation of when the bank can issue 1581 // an activate, ignoring any rank-to-rank switching 1582 // cost in this calculation 1583 Tick act_at = ranks[i]->banks[j].openRow == Bank::NO_ROW ? 1584 std::max(ranks[i]->banks[j].actAllowedAt, curTick()) : 1585 std::max(ranks[i]->banks[j].preAllowedAt, curTick()) + tRP; 1586 1587 // When is the earliest the R/W burst can issue? 1588 Tick col_at = std::max(ranks[i]->banks[j].colAllowedAt, 1589 act_at + tRCD); 1590 1591 // bank can issue burst back-to-back (seamlessly) with 1592 // previous burst 1593 bool new_seamless_bank = col_at <= min_col_at; 1594 1595 // if we found a new seamless bank or we have no 1596 // seamless banks, and got a bank with an earlier 1597 // activate time, it should be added to the bit mask 1598 if (new_seamless_bank || 1599 (!found_seamless_bank && act_at <= min_act_at)) { 1600 // if we did not have a seamless bank before, and 1601 // we do now, reset the bank mask, also reset it 1602 // if we have not yet found a seamless bank and 1603 // the activate time is smaller than what we have 1604 // seen so far 1605 if (!found_seamless_bank && 1606 (new_seamless_bank || act_at < min_act_at)) { 1607 bank_mask = 0; 1608 } 1609 1610 found_seamless_bank |= new_seamless_bank; 1611 1612 // ACT can occur 'behind the scenes' 1613 hidden_bank_prep = act_at <= hidden_act_max; 1614 1615 // set the bit corresponding to the available bank 1616 replaceBits(bank_mask, bank_id, bank_id, 1); 1617 min_act_at = act_at; 1618 } 1619 } 1620 } 1621 } 1622 1623 return make_pair(bank_mask, hidden_bank_prep); 1624} 1625 1626DRAMCtrl::Rank::Rank(DRAMCtrl& _memory, const DRAMCtrlParams* _p) 1627 : EventManager(&_memory), memory(_memory),
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1521 pwrStateTrans(PWR_IDLE), pwrState(PWR_IDLE), pwrStateTick(0), 1522 refreshState(REF_IDLE), refreshDueAt(0), 1523 power(_p, false), numBanksActive(0), 1524 activateEvent(*this), prechargeEvent(*this), 1525 refreshEvent(*this), powerEvent(*this)
| 1628 pwrStateTrans(PWR_IDLE), pwrStatePostRefresh(PWR_IDLE), 1629 pwrStateTick(0), refreshDueAt(0), pwrState(PWR_IDLE), 1630 refreshState(REF_IDLE), inLowPowerState(false), rank(0), 1631 readEntries(0), writeEntries(0), outstandingEvents(0), 1632 wakeUpAllowedAt(0), power(_p, false), numBanksActive(0), 1633 writeDoneEvent(*this), activateEvent(*this), prechargeEvent(*this), 1634 refreshEvent(*this), powerEvent(*this), wakeUpEvent(*this)
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1526{ } 1527 1528void 1529DRAMCtrl::Rank::startup(Tick ref_tick) 1530{ 1531 assert(ref_tick > curTick()); 1532 1533 pwrStateTick = curTick(); 1534 1535 // kick off the refresh, and give ourselves enough time to 1536 // precharge 1537 schedule(refreshEvent, ref_tick); 1538} 1539 1540void 1541DRAMCtrl::Rank::suspend() 1542{ 1543 deschedule(refreshEvent); 1544 1545 // Update the stats 1546 updatePowerStats();
| 1635{ } 1636 1637void 1638DRAMCtrl::Rank::startup(Tick ref_tick) 1639{ 1640 assert(ref_tick > curTick()); 1641 1642 pwrStateTick = curTick(); 1643 1644 // kick off the refresh, and give ourselves enough time to 1645 // precharge 1646 schedule(refreshEvent, ref_tick); 1647} 1648 1649void 1650DRAMCtrl::Rank::suspend() 1651{ 1652 deschedule(refreshEvent); 1653 1654 // Update the stats 1655 updatePowerStats();
|
| 1656 1657 // don't automatically transition back to LP state after next REF 1658 pwrStatePostRefresh = PWR_IDLE;
|
1547} 1548
| 1659} 1660
|
| 1661bool 1662DRAMCtrl::Rank::lowPowerEntryReady() const 1663{ 1664 bool no_queued_cmds = ((memory.busStateNext == READ) && (readEntries == 0)) 1665 || ((memory.busStateNext == WRITE) && 1666 (writeEntries == 0)); 1667 1668 if (refreshState == REF_RUN) { 1669 // have not decremented outstandingEvents for refresh command 1670 // still check if there are no commands queued to force PD 1671 // entry after refresh completes 1672 return no_queued_cmds; 1673 } else { 1674 // ensure no commands in Q and no commands scheduled 1675 return (no_queued_cmds && (outstandingEvents == 0)); 1676 } 1677} 1678
|
1549void 1550DRAMCtrl::Rank::checkDrainDone() 1551{ 1552 // if this rank was waiting to drain it is now able to proceed to 1553 // precharge 1554 if (refreshState == REF_DRAIN) { 1555 DPRINTF(DRAM, "Refresh drain done, now precharging\n"); 1556
| 1679void 1680DRAMCtrl::Rank::checkDrainDone() 1681{ 1682 // if this rank was waiting to drain it is now able to proceed to 1683 // precharge 1684 if (refreshState == REF_DRAIN) { 1685 DPRINTF(DRAM, "Refresh drain done, now precharging\n"); 1686
|
1557 refreshState = REF_PRE;
| 1687 refreshState = REF_PD_EXIT;
|
1558 1559 // hand control back to the refresh event loop 1560 schedule(refreshEvent, curTick()); 1561 } 1562} 1563 1564void 1565DRAMCtrl::Rank::flushCmdList() 1566{ 1567 // at the moment sort the list of commands and update the counters 1568 // for DRAMPower libray when doing a refresh 1569 sort(cmdList.begin(), cmdList.end(), DRAMCtrl::sortTime); 1570 1571 auto next_iter = cmdList.begin(); 1572 // push to commands to DRAMPower 1573 for ( ; next_iter != cmdList.end() ; ++next_iter) { 1574 Command cmd = *next_iter; 1575 if (cmd.timeStamp <= curTick()) { 1576 // Move all commands at or before curTick to DRAMPower 1577 power.powerlib.doCommand(cmd.type, cmd.bank, 1578 divCeil(cmd.timeStamp, memory.tCK) - 1579 memory.timeStampOffset); 1580 } else { 1581 // done - found all commands at or before curTick() 1582 // next_iter references the 1st command after curTick 1583 break; 1584 } 1585 } 1586 // reset cmdList to only contain commands after curTick 1587 // if there are no commands after curTick, updated cmdList will be empty 1588 // in this case, next_iter is cmdList.end() 1589 cmdList.assign(next_iter, cmdList.end()); 1590} 1591 1592void 1593DRAMCtrl::Rank::processActivateEvent() 1594{ 1595 // we should transition to the active state as soon as any bank is active 1596 if (pwrState != PWR_ACT) 1597 // note that at this point numBanksActive could be back at 1598 // zero again due to a precharge scheduled in the future 1599 schedulePowerEvent(PWR_ACT, curTick()); 1600} 1601 1602void 1603DRAMCtrl::Rank::processPrechargeEvent() 1604{
| 1688 1689 // hand control back to the refresh event loop 1690 schedule(refreshEvent, curTick()); 1691 } 1692} 1693 1694void 1695DRAMCtrl::Rank::flushCmdList() 1696{ 1697 // at the moment sort the list of commands and update the counters 1698 // for DRAMPower libray when doing a refresh 1699 sort(cmdList.begin(), cmdList.end(), DRAMCtrl::sortTime); 1700 1701 auto next_iter = cmdList.begin(); 1702 // push to commands to DRAMPower 1703 for ( ; next_iter != cmdList.end() ; ++next_iter) { 1704 Command cmd = *next_iter; 1705 if (cmd.timeStamp <= curTick()) { 1706 // Move all commands at or before curTick to DRAMPower 1707 power.powerlib.doCommand(cmd.type, cmd.bank, 1708 divCeil(cmd.timeStamp, memory.tCK) - 1709 memory.timeStampOffset); 1710 } else { 1711 // done - found all commands at or before curTick() 1712 // next_iter references the 1st command after curTick 1713 break; 1714 } 1715 } 1716 // reset cmdList to only contain commands after curTick 1717 // if there are no commands after curTick, updated cmdList will be empty 1718 // in this case, next_iter is cmdList.end() 1719 cmdList.assign(next_iter, cmdList.end()); 1720} 1721 1722void 1723DRAMCtrl::Rank::processActivateEvent() 1724{ 1725 // we should transition to the active state as soon as any bank is active 1726 if (pwrState != PWR_ACT) 1727 // note that at this point numBanksActive could be back at 1728 // zero again due to a precharge scheduled in the future 1729 schedulePowerEvent(PWR_ACT, curTick()); 1730} 1731 1732void 1733DRAMCtrl::Rank::processPrechargeEvent() 1734{
|
| 1735 // counter should at least indicate one outstanding request 1736 // for this precharge 1737 assert(outstandingEvents > 0); 1738 // precharge complete, decrement count 1739 --outstandingEvents; 1740
|
1605 // if we reached zero, then special conditions apply as we track 1606 // if all banks are precharged for the power models 1607 if (numBanksActive == 0) {
| 1741 // if we reached zero, then special conditions apply as we track 1742 // if all banks are precharged for the power models 1743 if (numBanksActive == 0) {
|
1608 // we should transition to the idle state when the last bank 1609 // is precharged 1610 schedulePowerEvent(PWR_IDLE, curTick());
| 1744 // no reads to this rank in the Q and no pending 1745 // RD/WR or refresh commands 1746 if (lowPowerEntryReady()) { 1747 // should still be in ACT state since bank still open 1748 assert(pwrState == PWR_ACT); 1749 1750 // All banks closed - switch to precharge power down state. 1751 DPRINTF(DRAMState, "Rank %d sleep at tick %d\n", 1752 rank, curTick()); 1753 powerDownSleep(PWR_PRE_PDN, curTick()); 1754 } else { 1755 // we should transition to the idle state when the last bank 1756 // is precharged 1757 schedulePowerEvent(PWR_IDLE, curTick()); 1758 }
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1611 } 1612} 1613 1614void
| 1759 } 1760} 1761 1762void
|
| 1763DRAMCtrl::Rank::processWriteDoneEvent() 1764{ 1765 // counter should at least indicate one outstanding request 1766 // for this write 1767 assert(outstandingEvents > 0); 1768 // Write transfer on bus has completed 1769 // decrement per rank counter 1770 --outstandingEvents; 1771} 1772 1773void
|
1615DRAMCtrl::Rank::processRefreshEvent() 1616{ 1617 // when first preparing the refresh, remember when it was due
| 1774DRAMCtrl::Rank::processRefreshEvent() 1775{ 1776 // when first preparing the refresh, remember when it was due
|
1618 if (refreshState == REF_IDLE) {
| 1777 if ((refreshState == REF_IDLE) || (refreshState == REF_SREF_EXIT)) {
|
1619 // remember when the refresh is due 1620 refreshDueAt = curTick(); 1621 1622 // proceed to drain 1623 refreshState = REF_DRAIN; 1624
| 1778 // remember when the refresh is due 1779 refreshDueAt = curTick(); 1780 1781 // proceed to drain 1782 refreshState = REF_DRAIN; 1783
|
| 1784 // make nonzero while refresh is pending to ensure 1785 // power down and self-refresh are not entered 1786 ++outstandingEvents; 1787
|
1625 DPRINTF(DRAM, "Refresh due\n"); 1626 } 1627 1628 // let any scheduled read or write to the same rank go ahead, 1629 // after which it will 1630 // hand control back to this event loop 1631 if (refreshState == REF_DRAIN) { 1632 // if a request is at the moment being handled and this request is 1633 // accessing the current rank then wait for it to finish 1634 if ((rank == memory.activeRank) 1635 && (memory.nextReqEvent.scheduled())) { 1636 // hand control over to the request loop until it is 1637 // evaluated next 1638 DPRINTF(DRAM, "Refresh awaiting draining\n"); 1639 1640 return; 1641 } else {
| 1788 DPRINTF(DRAM, "Refresh due\n"); 1789 } 1790 1791 // let any scheduled read or write to the same rank go ahead, 1792 // after which it will 1793 // hand control back to this event loop 1794 if (refreshState == REF_DRAIN) { 1795 // if a request is at the moment being handled and this request is 1796 // accessing the current rank then wait for it to finish 1797 if ((rank == memory.activeRank) 1798 && (memory.nextReqEvent.scheduled())) { 1799 // hand control over to the request loop until it is 1800 // evaluated next 1801 DPRINTF(DRAM, "Refresh awaiting draining\n"); 1802 1803 return; 1804 } else {
|
| 1805 refreshState = REF_PD_EXIT; 1806 } 1807 } 1808 1809 // at this point, ensure that rank is not in a power-down state 1810 if (refreshState == REF_PD_EXIT) { 1811 // if rank was sleeping and we have't started exit process, 1812 // wake-up for refresh 1813 if (inLowPowerState) { 1814 DPRINTF(DRAM, "Wake Up for refresh\n"); 1815 // save state and return after refresh completes 1816 scheduleWakeUpEvent(memory.tXP); 1817 return; 1818 } else {
|
1642 refreshState = REF_PRE; 1643 } 1644 } 1645 1646 // at this point, ensure that all banks are precharged 1647 if (refreshState == REF_PRE) {
| 1819 refreshState = REF_PRE; 1820 } 1821 } 1822 1823 // at this point, ensure that all banks are precharged 1824 if (refreshState == REF_PRE) {
|
1648 // precharge any active bank if we are not already in the idle 1649 // state 1650 if (pwrState != PWR_IDLE) {
| 1825 // precharge any active bank 1826 if (numBanksActive != 0) {
|
1651 // at the moment, we use a precharge all even if there is 1652 // only a single bank open 1653 DPRINTF(DRAM, "Precharging all\n"); 1654 1655 // first determine when we can precharge 1656 Tick pre_at = curTick(); 1657 1658 for (auto &b : banks) { 1659 // respect both causality and any existing bank 1660 // constraints, some banks could already have a 1661 // (auto) precharge scheduled 1662 pre_at = std::max(b.preAllowedAt, pre_at); 1663 } 1664 1665 // make sure all banks per rank are precharged, and for those that 1666 // already are, update their availability 1667 Tick act_allowed_at = pre_at + memory.tRP; 1668 1669 for (auto &b : banks) { 1670 if (b.openRow != Bank::NO_ROW) { 1671 memory.prechargeBank(*this, b, pre_at, false); 1672 } else { 1673 b.actAllowedAt = std::max(b.actAllowedAt, act_allowed_at); 1674 b.preAllowedAt = std::max(b.preAllowedAt, pre_at); 1675 } 1676 } 1677 1678 // precharge all banks in rank 1679 cmdList.push_back(Command(MemCommand::PREA, 0, pre_at)); 1680 1681 DPRINTF(DRAMPower, "%llu,PREA,0,%d\n", 1682 divCeil(pre_at, memory.tCK) - 1683 memory.timeStampOffset, rank);
| 1827 // at the moment, we use a precharge all even if there is 1828 // only a single bank open 1829 DPRINTF(DRAM, "Precharging all\n"); 1830 1831 // first determine when we can precharge 1832 Tick pre_at = curTick(); 1833 1834 for (auto &b : banks) { 1835 // respect both causality and any existing bank 1836 // constraints, some banks could already have a 1837 // (auto) precharge scheduled 1838 pre_at = std::max(b.preAllowedAt, pre_at); 1839 } 1840 1841 // make sure all banks per rank are precharged, and for those that 1842 // already are, update their availability 1843 Tick act_allowed_at = pre_at + memory.tRP; 1844 1845 for (auto &b : banks) { 1846 if (b.openRow != Bank::NO_ROW) { 1847 memory.prechargeBank(*this, b, pre_at, false); 1848 } else { 1849 b.actAllowedAt = std::max(b.actAllowedAt, act_allowed_at); 1850 b.preAllowedAt = std::max(b.preAllowedAt, pre_at); 1851 } 1852 } 1853 1854 // precharge all banks in rank 1855 cmdList.push_back(Command(MemCommand::PREA, 0, pre_at)); 1856 1857 DPRINTF(DRAMPower, "%llu,PREA,0,%d\n", 1858 divCeil(pre_at, memory.tCK) - 1859 memory.timeStampOffset, rank);
|
1684 } else {
| 1860 } else if ((pwrState == PWR_IDLE) && (outstandingEvents == 1)) { 1861 // Banks are closed, have transitioned to IDLE state, and 1862 // no outstanding ACT,RD/WR,Auto-PRE sequence scheduled
|
1685 DPRINTF(DRAM, "All banks already precharged, starting refresh\n"); 1686
| 1863 DPRINTF(DRAM, "All banks already precharged, starting refresh\n"); 1864
|
1687 // go ahead and kick the power state machine into gear if
| 1865 // go ahead and kick the power state machine into gear since
|
1688 // we are already idle 1689 schedulePowerEvent(PWR_REF, curTick());
| 1866 // we are already idle 1867 schedulePowerEvent(PWR_REF, curTick());
|
| 1868 } else { 1869 // banks state is closed but haven't transitioned pwrState to IDLE 1870 // or have outstanding ACT,RD/WR,Auto-PRE sequence scheduled 1871 // should have outstanding precharge event in this case 1872 assert(prechargeEvent.scheduled()); 1873 // will start refresh when pwrState transitions to IDLE
|
1690 } 1691
| 1874 } 1875
|
1692 refreshState = REF_RUN;
| |
1693 assert(numBanksActive == 0); 1694 1695 // wait for all banks to be precharged, at which point the 1696 // power state machine will transition to the idle state, and 1697 // automatically move to a refresh, at that point it will also 1698 // call this method to get the refresh event loop going again 1699 return; 1700 } 1701 1702 // last but not least we perform the actual refresh
| 1876 assert(numBanksActive == 0); 1877 1878 // wait for all banks to be precharged, at which point the 1879 // power state machine will transition to the idle state, and 1880 // automatically move to a refresh, at that point it will also 1881 // call this method to get the refresh event loop going again 1882 return; 1883 } 1884 1885 // last but not least we perform the actual refresh
|
1703 if (refreshState == REF_RUN) {
| 1886 if (refreshState == REF_START) {
|
1704 // should never get here with any banks active 1705 assert(numBanksActive == 0); 1706 assert(pwrState == PWR_REF); 1707 1708 Tick ref_done_at = curTick() + memory.tRFC; 1709 1710 for (auto &b : banks) { 1711 b.actAllowedAt = ref_done_at; 1712 } 1713 1714 // at the moment this affects all ranks 1715 cmdList.push_back(Command(MemCommand::REF, 0, curTick())); 1716 1717 // Update the stats 1718 updatePowerStats(); 1719 1720 DPRINTF(DRAMPower, "%llu,REF,0,%d\n", divCeil(curTick(), memory.tCK) - 1721 memory.timeStampOffset, rank); 1722
| 1887 // should never get here with any banks active 1888 assert(numBanksActive == 0); 1889 assert(pwrState == PWR_REF); 1890 1891 Tick ref_done_at = curTick() + memory.tRFC; 1892 1893 for (auto &b : banks) { 1894 b.actAllowedAt = ref_done_at; 1895 } 1896 1897 // at the moment this affects all ranks 1898 cmdList.push_back(Command(MemCommand::REF, 0, curTick())); 1899 1900 // Update the stats 1901 updatePowerStats(); 1902 1903 DPRINTF(DRAMPower, "%llu,REF,0,%d\n", divCeil(curTick(), memory.tCK) - 1904 memory.timeStampOffset, rank); 1905
|
| 1906 // Update for next refresh 1907 refreshDueAt += memory.tREFI; 1908
|
1723 // make sure we did not wait so long that we cannot make up 1724 // for it
| 1909 // make sure we did not wait so long that we cannot make up 1910 // for it
|
1725 if (refreshDueAt + memory.tREFI < ref_done_at) {
| 1911 if (refreshDueAt < ref_done_at) {
|
1726 fatal("Refresh was delayed so long we cannot catch up\n"); 1727 } 1728
| 1912 fatal("Refresh was delayed so long we cannot catch up\n"); 1913 } 1914
|
1729 // compensate for the delay in actually performing the refresh 1730 // when scheduling the next one 1731 schedule(refreshEvent, refreshDueAt + memory.tREFI - memory.tRP);
| 1915 // Run the refresh and schedule event to transition power states 1916 // when refresh completes 1917 refreshState = REF_RUN; 1918 schedule(refreshEvent, ref_done_at); 1919 return; 1920 }
|
1732
| 1921
|
| 1922 if (refreshState == REF_RUN) { 1923 // should never get here with any banks active 1924 assert(numBanksActive == 0); 1925 assert(pwrState == PWR_REF); 1926
|
1733 assert(!powerEvent.scheduled()); 1734
| 1927 assert(!powerEvent.scheduled()); 1928
|
1735 // move to the idle power state once the refresh is done, this 1736 // will also move the refresh state machine to the refresh 1737 // idle state 1738 schedulePowerEvent(PWR_IDLE, ref_done_at);
| 1929 if ((memory.drainState() == DrainState::Draining) || 1930 (memory.drainState() == DrainState::Drained)) { 1931 // if draining, do not re-enter low-power mode. 1932 // simply go to IDLE and wait 1933 schedulePowerEvent(PWR_IDLE, curTick()); 1934 } else { 1935 // At the moment, we sleep when the refresh ends and wait to be 1936 // woken up again if previously in a low-power state. 1937 if (pwrStatePostRefresh != PWR_IDLE) { 1938 // power State should be power Refresh 1939 assert(pwrState == PWR_REF); 1940 DPRINTF(DRAMState, "Rank %d sleeping after refresh and was in " 1941 "power state %d before refreshing\n", rank, 1942 pwrStatePostRefresh); 1943 powerDownSleep(pwrState, curTick());
|
1739
| 1944
|
1740 DPRINTF(DRAMState, "Refresh done at %llu and next refresh at %llu\n", 1741 ref_done_at, refreshDueAt + memory.tREFI);
| 1945 // Force PRE power-down if there are no outstanding commands 1946 // in Q after refresh. 1947 } else if (lowPowerEntryReady()) { 1948 DPRINTF(DRAMState, "Rank %d sleeping after refresh but was NOT" 1949 " in a low power state before refreshing\n", rank); 1950 powerDownSleep(PWR_PRE_PDN, curTick()); 1951 1952 } else { 1953 // move to the idle power state once the refresh is done, this 1954 // will also move the refresh state machine to the refresh 1955 // idle state 1956 schedulePowerEvent(PWR_IDLE, curTick()); 1957 } 1958 } 1959 1960 // if transitioning to self refresh do not schedule a new refresh; 1961 // when waking from self refresh, a refresh is scheduled again. 1962 if (pwrStateTrans != PWR_SREF) { 1963 // compensate for the delay in actually performing the refresh 1964 // when scheduling the next one 1965 schedule(refreshEvent, refreshDueAt - memory.tRP); 1966 1967 DPRINTF(DRAMState, "Refresh done at %llu and next refresh" 1968 " at %llu\n", curTick(), refreshDueAt); 1969 }
|
1742 } 1743} 1744 1745void 1746DRAMCtrl::Rank::schedulePowerEvent(PowerState pwr_state, Tick tick) 1747{ 1748 // respect causality 1749 assert(tick >= curTick()); 1750 1751 if (!powerEvent.scheduled()) { 1752 DPRINTF(DRAMState, "Scheduling power event at %llu to state %d\n", 1753 tick, pwr_state); 1754 1755 // insert the new transition 1756 pwrStateTrans = pwr_state; 1757 1758 schedule(powerEvent, tick); 1759 } else { 1760 panic("Scheduled power event at %llu to state %d, " 1761 "with scheduled event at %llu to %d\n", tick, pwr_state, 1762 powerEvent.when(), pwrStateTrans); 1763 } 1764} 1765 1766void
| 1970 } 1971} 1972 1973void 1974DRAMCtrl::Rank::schedulePowerEvent(PowerState pwr_state, Tick tick) 1975{ 1976 // respect causality 1977 assert(tick >= curTick()); 1978 1979 if (!powerEvent.scheduled()) { 1980 DPRINTF(DRAMState, "Scheduling power event at %llu to state %d\n", 1981 tick, pwr_state); 1982 1983 // insert the new transition 1984 pwrStateTrans = pwr_state; 1985 1986 schedule(powerEvent, tick); 1987 } else { 1988 panic("Scheduled power event at %llu to state %d, " 1989 "with scheduled event at %llu to %d\n", tick, pwr_state, 1990 powerEvent.when(), pwrStateTrans); 1991 } 1992} 1993 1994void
|
| 1995DRAMCtrl::Rank::powerDownSleep(PowerState pwr_state, Tick tick) 1996{ 1997 // if low power state is active low, schedule to active low power state. 1998 // in reality tCKE is needed to enter active low power. This is neglected 1999 // here and could be added in the future. 2000 if (pwr_state == PWR_ACT_PDN) { 2001 schedulePowerEvent(pwr_state, tick); 2002 // push command to DRAMPower 2003 cmdList.push_back(Command(MemCommand::PDN_F_ACT, 0, tick)); 2004 DPRINTF(DRAMPower, "%llu,PDN_F_ACT,0,%d\n", divCeil(tick, 2005 memory.tCK) - memory.timeStampOffset, rank); 2006 } else if (pwr_state == PWR_PRE_PDN) { 2007 // if low power state is precharge low, schedule to precharge low 2008 // power state. In reality tCKE is needed to enter active low power. 2009 // This is neglected here. 2010 schedulePowerEvent(pwr_state, tick); 2011 //push Command to DRAMPower 2012 cmdList.push_back(Command(MemCommand::PDN_F_PRE, 0, tick)); 2013 DPRINTF(DRAMPower, "%llu,PDN_F_PRE,0,%d\n", divCeil(tick, 2014 memory.tCK) - memory.timeStampOffset, rank); 2015 } else if (pwr_state == PWR_REF) { 2016 // if a refresh just occured 2017 // transition to PRE_PDN now that all banks are closed 2018 // do not transition to SREF if commands are in Q; stay in PRE_PDN 2019 if (pwrStatePostRefresh == PWR_ACT_PDN || !lowPowerEntryReady()) { 2020 // prechage power down requires tCKE to enter. For simplicity 2021 // this is not considered. 2022 schedulePowerEvent(PWR_PRE_PDN, tick); 2023 //push Command to DRAMPower 2024 cmdList.push_back(Command(MemCommand::PDN_F_PRE, 0, tick)); 2025 DPRINTF(DRAMPower, "%llu,PDN_F_PRE,0,%d\n", divCeil(tick, 2026 memory.tCK) - memory.timeStampOffset, rank); 2027 } else { 2028 // last low power State was power precharge 2029 assert(pwrStatePostRefresh == PWR_PRE_PDN); 2030 // self refresh requires time tCKESR to enter. For simplicity, 2031 // this is not considered. 2032 schedulePowerEvent(PWR_SREF, tick); 2033 // push Command to DRAMPower 2034 cmdList.push_back(Command(MemCommand::SREN, 0, tick)); 2035 DPRINTF(DRAMPower, "%llu,SREN,0,%d\n", divCeil(tick, 2036 memory.tCK) - memory.timeStampOffset, rank); 2037 } 2038 } 2039 // Ensure that we don't power-down and back up in same tick 2040 // Once we commit to PD entry, do it and wait for at least 1tCK 2041 // This could be replaced with tCKE if/when that is added to the model 2042 wakeUpAllowedAt = tick + memory.tCK; 2043 2044 // Transitioning to a low power state, set flag 2045 inLowPowerState = true; 2046} 2047 2048void 2049DRAMCtrl::Rank::scheduleWakeUpEvent(Tick exit_delay) 2050{ 2051 Tick wake_up_tick = std::max(curTick(), wakeUpAllowedAt); 2052 2053 DPRINTF(DRAMState, "Scheduling wake-up for rank %d at tick %d\n", 2054 rank, wake_up_tick); 2055 2056 // if waking for refresh, hold previous state 2057 // else reset state back to IDLE 2058 if (refreshState == REF_PD_EXIT) { 2059 pwrStatePostRefresh = pwrState; 2060 } else { 2061 // don't automatically transition back to LP state after next REF 2062 pwrStatePostRefresh = PWR_IDLE; 2063 } 2064 2065 // schedule wake-up with event to ensure entry has completed before 2066 // we try to wake-up 2067 schedule(wakeUpEvent, wake_up_tick); 2068 2069 for (auto &b : banks) { 2070 // respect both causality and any existing bank 2071 // constraints, some banks could already have a 2072 // (auto) precharge scheduled 2073 b.colAllowedAt = std::max(wake_up_tick + exit_delay, b.colAllowedAt); 2074 b.preAllowedAt = std::max(wake_up_tick + exit_delay, b.preAllowedAt); 2075 b.actAllowedAt = std::max(wake_up_tick + exit_delay, b.actAllowedAt); 2076 } 2077 // Transitioning out of low power state, clear flag 2078 inLowPowerState = false; 2079 2080 // push to DRAMPower 2081 // use pwrStateTrans for cases where we have a power event scheduled 2082 // to enter low power that has not yet been processed 2083 if (pwrStateTrans == PWR_ACT_PDN) { 2084 cmdList.push_back(Command(MemCommand::PUP_ACT, 0, wake_up_tick)); 2085 DPRINTF(DRAMPower, "%llu,PUP_ACT,0,%d\n", divCeil(wake_up_tick, 2086 memory.tCK) - memory.timeStampOffset, rank); 2087 2088 } else if (pwrStateTrans == PWR_PRE_PDN) { 2089 cmdList.push_back(Command(MemCommand::PUP_PRE, 0, wake_up_tick)); 2090 DPRINTF(DRAMPower, "%llu,PUP_PRE,0,%d\n", divCeil(wake_up_tick, 2091 memory.tCK) - memory.timeStampOffset, rank); 2092 } else if (pwrStateTrans == PWR_SREF) { 2093 cmdList.push_back(Command(MemCommand::SREX, 0, wake_up_tick)); 2094 DPRINTF(DRAMPower, "%llu,SREX,0,%d\n", divCeil(wake_up_tick, 2095 memory.tCK) - memory.timeStampOffset, rank); 2096 } 2097} 2098 2099void 2100DRAMCtrl::Rank::processWakeUpEvent() 2101{ 2102 // Should be in a power-down or self-refresh state 2103 assert((pwrState == PWR_ACT_PDN) || (pwrState == PWR_PRE_PDN) || 2104 (pwrState == PWR_SREF)); 2105 2106 // Check current state to determine transition state 2107 if (pwrState == PWR_ACT_PDN) { 2108 // banks still open, transition to PWR_ACT 2109 schedulePowerEvent(PWR_ACT, curTick()); 2110 } else { 2111 // transitioning from a precharge power-down or self-refresh state 2112 // banks are closed - transition to PWR_IDLE 2113 schedulePowerEvent(PWR_IDLE, curTick()); 2114 } 2115} 2116 2117void
|
1767DRAMCtrl::Rank::processPowerEvent() 1768{
| 2118DRAMCtrl::Rank::processPowerEvent() 2119{
|
| 2120 assert(curTick() >= pwrStateTick);
|
1769 // remember where we were, and for how long 1770 Tick duration = curTick() - pwrStateTick; 1771 PowerState prev_state = pwrState; 1772 1773 // update the accounting 1774 pwrStateTime[prev_state] += duration; 1775
| 2121 // remember where we were, and for how long 2122 Tick duration = curTick() - pwrStateTick; 2123 PowerState prev_state = pwrState; 2124 2125 // update the accounting 2126 pwrStateTime[prev_state] += duration; 2127
|
| 2128 // track to total idle time 2129 if ((prev_state == PWR_PRE_PDN) || (prev_state == PWR_ACT_PDN) || 2130 (prev_state == PWR_SREF)) { 2131 totalIdleTime += duration; 2132 } 2133
|
1776 pwrState = pwrStateTrans; 1777 pwrStateTick = curTick(); 1778
| 2134 pwrState = pwrStateTrans; 2135 pwrStateTick = curTick(); 2136
|
1779 if (pwrState == PWR_IDLE) { 1780 DPRINTF(DRAMState, "All banks precharged\n");
| 2137 // if rank was refreshing, make sure to start scheduling requests again 2138 if (prev_state == PWR_REF) { 2139 // bus IDLED prior to REF 2140 // counter should be one for refresh command only 2141 assert(outstandingEvents == 1); 2142 // REF complete, decrement count 2143 --outstandingEvents;
|
1781
| 2144
|
1782 // if we were refreshing, make sure we start scheduling requests again 1783 if (prev_state == PWR_REF) { 1784 DPRINTF(DRAMState, "Was refreshing for %llu ticks\n", duration); 1785 assert(pwrState == PWR_IDLE); 1786 1787 // kick things into action again
| 2145 DPRINTF(DRAMState, "Was refreshing for %llu ticks\n", duration); 2146 // if sleeping after refresh 2147 if (pwrState != PWR_IDLE) { 2148 assert((pwrState == PWR_PRE_PDN) || (pwrState == PWR_SREF)); 2149 DPRINTF(DRAMState, "Switching to power down state after refreshing" 2150 " rank %d at %llu tick\n", rank, curTick()); 2151 } 2152 if (pwrState != PWR_SREF) { 2153 // rank is not available in SREF 2154 // don't transition to IDLE in this case
|
1788 refreshState = REF_IDLE;
| 2155 refreshState = REF_IDLE;
|
1789 // a request event could be already scheduled by the state 1790 // machine of the other rank 1791 if (!memory.nextReqEvent.scheduled()) 1792 schedule(memory.nextReqEvent, curTick()); 1793 } else { 1794 assert(prev_state == PWR_ACT);
| 2156 } 2157 // a request event could be already scheduled by the state 2158 // machine of the other rank 2159 if (!memory.nextReqEvent.scheduled()) { 2160 DPRINTF(DRAM, "Scheduling next request after refreshing rank %d\n", 2161 rank); 2162 schedule(memory.nextReqEvent, curTick()); 2163 } 2164 } else if (pwrState == PWR_ACT) { 2165 if (refreshState == REF_PD_EXIT) { 2166 // kick the refresh event loop into action again 2167 assert(prev_state == PWR_ACT_PDN);
|
1795
| 2168
|
| 2169 // go back to REF event and close banks 2170 refreshState = REF_PRE; 2171 schedule(refreshEvent, curTick()); 2172 } 2173 } else if (pwrState == PWR_IDLE) { 2174 DPRINTF(DRAMState, "All banks precharged\n"); 2175 if (prev_state == PWR_SREF) { 2176 // set refresh state to REF_SREF_EXIT, ensuring isAvailable 2177 // continues to return false during tXS after SREF exit 2178 // Schedule a refresh which kicks things back into action 2179 // when it finishes 2180 refreshState = REF_SREF_EXIT; 2181 schedule(refreshEvent, curTick() + memory.tXS); 2182 } else {
|
1796 // if we have a pending refresh, and are now moving to
| 2183 // if we have a pending refresh, and are now moving to
|
1797 // the idle state, direclty transition to a refresh 1798 if (refreshState == REF_RUN) { 1799 // there should be nothing waiting at this point 1800 assert(!powerEvent.scheduled()); 1801 1802 // update the state in zero time and proceed below 1803 pwrState = PWR_REF;
| 2184 // the idle state, directly transition to a refresh 2185 if ((refreshState == REF_PRE) || (refreshState == REF_PD_EXIT)) { 2186 // ensure refresh is restarted only after final PRE command. 2187 // do not restart refresh if controller is in an intermediate 2188 // state, after PRE_PDN exit, when banks are IDLE but an 2189 // ACT is scheduled. 2190 if (!activateEvent.scheduled()) { 2191 // there should be nothing waiting at this point 2192 assert(!powerEvent.scheduled()); 2193 // update the state in zero time and proceed below 2194 pwrState = PWR_REF; 2195 } else { 2196 // must have PRE scheduled to transition back to IDLE 2197 // and re-kick off refresh 2198 assert(prechargeEvent.scheduled()); 2199 }
|
1804 }
| 2200 }
|
1805 }
| 2201 }
|
1806 } 1807 1808 // we transition to the refresh state, let the refresh state 1809 // machine know of this state update and let it deal with the 1810 // scheduling of the next power state transition as well as the 1811 // following refresh 1812 if (pwrState == PWR_REF) {
| 2202 } 2203 2204 // we transition to the refresh state, let the refresh state 2205 // machine know of this state update and let it deal with the 2206 // scheduling of the next power state transition as well as the 2207 // following refresh 2208 if (pwrState == PWR_REF) {
|
| 2209 assert(refreshState == REF_PRE || refreshState == REF_PD_EXIT);
|
1813 DPRINTF(DRAMState, "Refreshing\n");
| 2210 DPRINTF(DRAMState, "Refreshing\n");
|
| 2211
|
1814 // kick the refresh event loop into action again, and that 1815 // in turn will schedule a transition to the idle power 1816 // state once the refresh is done
| 2212 // kick the refresh event loop into action again, and that 2213 // in turn will schedule a transition to the idle power 2214 // state once the refresh is done
|
1817 assert(refreshState == REF_RUN); 1818 processRefreshEvent();
| 2215 if (refreshState == REF_PD_EXIT) { 2216 // Wait for PD exit timing to complete before issuing REF 2217 schedule(refreshEvent, curTick() + memory.tXP); 2218 } else { 2219 schedule(refreshEvent, curTick()); 2220 } 2221 // Banks transitioned to IDLE, start REF 2222 refreshState = REF_START;
|
1819 } 1820} 1821 1822void 1823DRAMCtrl::Rank::updatePowerStats() 1824{ 1825 // All commands up to refresh have completed 1826 // flush cmdList to DRAMPower 1827 flushCmdList(); 1828 1829 // update the counters for DRAMPower, passing false to 1830 // indicate that this is not the last command in the 1831 // list. DRAMPower requires this information for the 1832 // correct calculation of the background energy at the end 1833 // of the simulation. Ideally we would want to call this 1834 // function with true once at the end of the 1835 // simulation. However, the discarded energy is extremly 1836 // small and does not effect the final results. 1837 power.powerlib.updateCounters(false); 1838 1839 // call the energy function 1840 power.powerlib.calcEnergy(); 1841 1842 // Get the energy and power from DRAMPower 1843 Data::MemoryPowerModel::Energy energy = 1844 power.powerlib.getEnergy(); 1845 Data::MemoryPowerModel::Power rank_power = 1846 power.powerlib.getPower(); 1847 1848 actEnergy = energy.act_energy * memory.devicesPerRank; 1849 preEnergy = energy.pre_energy * memory.devicesPerRank; 1850 readEnergy = energy.read_energy * memory.devicesPerRank; 1851 writeEnergy = energy.write_energy * memory.devicesPerRank; 1852 refreshEnergy = energy.ref_energy * memory.devicesPerRank; 1853 actBackEnergy = energy.act_stdby_energy * memory.devicesPerRank; 1854 preBackEnergy = energy.pre_stdby_energy * memory.devicesPerRank;
| 2223 } 2224} 2225 2226void 2227DRAMCtrl::Rank::updatePowerStats() 2228{ 2229 // All commands up to refresh have completed 2230 // flush cmdList to DRAMPower 2231 flushCmdList(); 2232 2233 // update the counters for DRAMPower, passing false to 2234 // indicate that this is not the last command in the 2235 // list. DRAMPower requires this information for the 2236 // correct calculation of the background energy at the end 2237 // of the simulation. Ideally we would want to call this 2238 // function with true once at the end of the 2239 // simulation. However, the discarded energy is extremly 2240 // small and does not effect the final results. 2241 power.powerlib.updateCounters(false); 2242 2243 // call the energy function 2244 power.powerlib.calcEnergy(); 2245 2246 // Get the energy and power from DRAMPower 2247 Data::MemoryPowerModel::Energy energy = 2248 power.powerlib.getEnergy(); 2249 Data::MemoryPowerModel::Power rank_power = 2250 power.powerlib.getPower(); 2251 2252 actEnergy = energy.act_energy * memory.devicesPerRank; 2253 preEnergy = energy.pre_energy * memory.devicesPerRank; 2254 readEnergy = energy.read_energy * memory.devicesPerRank; 2255 writeEnergy = energy.write_energy * memory.devicesPerRank; 2256 refreshEnergy = energy.ref_energy * memory.devicesPerRank; 2257 actBackEnergy = energy.act_stdby_energy * memory.devicesPerRank; 2258 preBackEnergy = energy.pre_stdby_energy * memory.devicesPerRank;
|
| 2259 actPowerDownEnergy = energy.f_act_pd_energy * memory.devicesPerRank; 2260 prePowerDownEnergy = energy.f_pre_pd_energy * memory.devicesPerRank; 2261 selfRefreshEnergy = energy.sref_energy * memory.devicesPerRank;
|
1855 totalEnergy = energy.total_energy * memory.devicesPerRank; 1856 averagePower = rank_power.average_power * memory.devicesPerRank; 1857} 1858 1859void 1860DRAMCtrl::Rank::computeStats() 1861{ 1862 DPRINTF(DRAM,"Computing final stats\n"); 1863 1864 // Force DRAM power to update counters based on time spent in 1865 // current state up to curTick() 1866 cmdList.push_back(Command(MemCommand::NOP, 0, curTick())); 1867 1868 // Update the stats 1869 updatePowerStats(); 1870 1871 // final update of power state times 1872 pwrStateTime[pwrState] += (curTick() - pwrStateTick); 1873 pwrStateTick = curTick(); 1874 1875} 1876 1877void 1878DRAMCtrl::Rank::regStats() 1879{ 1880 using namespace Stats; 1881 1882 pwrStateTime
| 2262 totalEnergy = energy.total_energy * memory.devicesPerRank; 2263 averagePower = rank_power.average_power * memory.devicesPerRank; 2264} 2265 2266void 2267DRAMCtrl::Rank::computeStats() 2268{ 2269 DPRINTF(DRAM,"Computing final stats\n"); 2270 2271 // Force DRAM power to update counters based on time spent in 2272 // current state up to curTick() 2273 cmdList.push_back(Command(MemCommand::NOP, 0, curTick())); 2274 2275 // Update the stats 2276 updatePowerStats(); 2277 2278 // final update of power state times 2279 pwrStateTime[pwrState] += (curTick() - pwrStateTick); 2280 pwrStateTick = curTick(); 2281 2282} 2283 2284void 2285DRAMCtrl::Rank::regStats() 2286{ 2287 using namespace Stats; 2288 2289 pwrStateTime
|
1883 .init(5)
| 2290 .init(6)
|
1884 .name(name() + ".memoryStateTime") 1885 .desc("Time in different power states"); 1886 pwrStateTime.subname(0, "IDLE"); 1887 pwrStateTime.subname(1, "REF");
| 2291 .name(name() + ".memoryStateTime") 2292 .desc("Time in different power states"); 2293 pwrStateTime.subname(0, "IDLE"); 2294 pwrStateTime.subname(1, "REF");
|
1888 pwrStateTime.subname(2, "PRE_PDN"); 1889 pwrStateTime.subname(3, "ACT"); 1890 pwrStateTime.subname(4, "ACT_PDN");
| 2295 pwrStateTime.subname(2, "SREF"); 2296 pwrStateTime.subname(3, "PRE_PDN"); 2297 pwrStateTime.subname(4, "ACT"); 2298 pwrStateTime.subname(5, "ACT_PDN");
|
1891 1892 actEnergy 1893 .name(name() + ".actEnergy") 1894 .desc("Energy for activate commands per rank (pJ)"); 1895 1896 preEnergy 1897 .name(name() + ".preEnergy") 1898 .desc("Energy for precharge commands per rank (pJ)"); 1899 1900 readEnergy 1901 .name(name() + ".readEnergy") 1902 .desc("Energy for read commands per rank (pJ)"); 1903 1904 writeEnergy 1905 .name(name() + ".writeEnergy") 1906 .desc("Energy for write commands per rank (pJ)"); 1907 1908 refreshEnergy 1909 .name(name() + ".refreshEnergy") 1910 .desc("Energy for refresh commands per rank (pJ)"); 1911 1912 actBackEnergy 1913 .name(name() + ".actBackEnergy") 1914 .desc("Energy for active background per rank (pJ)"); 1915 1916 preBackEnergy 1917 .name(name() + ".preBackEnergy") 1918 .desc("Energy for precharge background per rank (pJ)"); 1919
| 2299 2300 actEnergy 2301 .name(name() + ".actEnergy") 2302 .desc("Energy for activate commands per rank (pJ)"); 2303 2304 preEnergy 2305 .name(name() + ".preEnergy") 2306 .desc("Energy for precharge commands per rank (pJ)"); 2307 2308 readEnergy 2309 .name(name() + ".readEnergy") 2310 .desc("Energy for read commands per rank (pJ)"); 2311 2312 writeEnergy 2313 .name(name() + ".writeEnergy") 2314 .desc("Energy for write commands per rank (pJ)"); 2315 2316 refreshEnergy 2317 .name(name() + ".refreshEnergy") 2318 .desc("Energy for refresh commands per rank (pJ)"); 2319 2320 actBackEnergy 2321 .name(name() + ".actBackEnergy") 2322 .desc("Energy for active background per rank (pJ)"); 2323 2324 preBackEnergy 2325 .name(name() + ".preBackEnergy") 2326 .desc("Energy for precharge background per rank (pJ)"); 2327
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| 2328 actPowerDownEnergy 2329 .name(name() + ".actPowerDownEnergy") 2330 .desc("Energy for active power-down per rank (pJ)"); 2331 2332 prePowerDownEnergy 2333 .name(name() + ".prePowerDownEnergy") 2334 .desc("Energy for precharge power-down per rank (pJ)"); 2335 2336 selfRefreshEnergy 2337 .name(name() + ".selfRefreshEnergy") 2338 .desc("Energy for self refresh per rank (pJ)"); 2339
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1920 totalEnergy 1921 .name(name() + ".totalEnergy") 1922 .desc("Total energy per rank (pJ)"); 1923 1924 averagePower 1925 .name(name() + ".averagePower") 1926 .desc("Core power per rank (mW)"); 1927
| 2340 totalEnergy 2341 .name(name() + ".totalEnergy") 2342 .desc("Total energy per rank (pJ)"); 2343 2344 averagePower 2345 .name(name() + ".averagePower") 2346 .desc("Core power per rank (mW)"); 2347
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| 2348 totalIdleTime 2349 .name(name() + ".totalIdleTime") 2350 .desc("Total Idle time Per DRAM Rank"); 2351
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1928 registerDumpCallback(new RankDumpCallback(this)); 1929} 1930void 1931DRAMCtrl::regStats() 1932{ 1933 using namespace Stats; 1934 1935 AbstractMemory::regStats(); 1936 1937 for (auto r : ranks) { 1938 r->regStats(); 1939 } 1940 1941 readReqs 1942 .name(name() + ".readReqs") 1943 .desc("Number of read requests accepted"); 1944 1945 writeReqs 1946 .name(name() + ".writeReqs") 1947 .desc("Number of write requests accepted"); 1948 1949 readBursts 1950 .name(name() + ".readBursts") 1951 .desc("Number of DRAM read bursts, " 1952 "including those serviced by the write queue"); 1953 1954 writeBursts 1955 .name(name() + ".writeBursts") 1956 .desc("Number of DRAM write bursts, " 1957 "including those merged in the write queue"); 1958 1959 servicedByWrQ 1960 .name(name() + ".servicedByWrQ") 1961 .desc("Number of DRAM read bursts serviced by the write queue"); 1962 1963 mergedWrBursts 1964 .name(name() + ".mergedWrBursts") 1965 .desc("Number of DRAM write bursts merged with an existing one"); 1966 1967 neitherReadNorWrite 1968 .name(name() + ".neitherReadNorWriteReqs") 1969 .desc("Number of requests that are neither read nor write"); 1970 1971 perBankRdBursts 1972 .init(banksPerRank * ranksPerChannel) 1973 .name(name() + ".perBankRdBursts") 1974 .desc("Per bank write bursts"); 1975 1976 perBankWrBursts 1977 .init(banksPerRank * ranksPerChannel) 1978 .name(name() + ".perBankWrBursts") 1979 .desc("Per bank write bursts"); 1980 1981 avgRdQLen 1982 .name(name() + ".avgRdQLen") 1983 .desc("Average read queue length when enqueuing") 1984 .precision(2); 1985 1986 avgWrQLen 1987 .name(name() + ".avgWrQLen") 1988 .desc("Average write queue length when enqueuing") 1989 .precision(2); 1990 1991 totQLat 1992 .name(name() + ".totQLat") 1993 .desc("Total ticks spent queuing"); 1994 1995 totBusLat 1996 .name(name() + ".totBusLat") 1997 .desc("Total ticks spent in databus transfers"); 1998 1999 totMemAccLat 2000 .name(name() + ".totMemAccLat") 2001 .desc("Total ticks spent from burst creation until serviced " 2002 "by the DRAM"); 2003 2004 avgQLat 2005 .name(name() + ".avgQLat") 2006 .desc("Average queueing delay per DRAM burst") 2007 .precision(2); 2008 2009 avgQLat = totQLat / (readBursts - servicedByWrQ); 2010 2011 avgBusLat 2012 .name(name() + ".avgBusLat") 2013 .desc("Average bus latency per DRAM burst") 2014 .precision(2); 2015 2016 avgBusLat = totBusLat / (readBursts - servicedByWrQ); 2017 2018 avgMemAccLat 2019 .name(name() + ".avgMemAccLat") 2020 .desc("Average memory access latency per DRAM burst") 2021 .precision(2); 2022 2023 avgMemAccLat = totMemAccLat / (readBursts - servicedByWrQ); 2024 2025 numRdRetry 2026 .name(name() + ".numRdRetry") 2027 .desc("Number of times read queue was full causing retry"); 2028 2029 numWrRetry 2030 .name(name() + ".numWrRetry") 2031 .desc("Number of times write queue was full causing retry"); 2032 2033 readRowHits 2034 .name(name() + ".readRowHits") 2035 .desc("Number of row buffer hits during reads"); 2036 2037 writeRowHits 2038 .name(name() + ".writeRowHits") 2039 .desc("Number of row buffer hits during writes"); 2040 2041 readRowHitRate 2042 .name(name() + ".readRowHitRate") 2043 .desc("Row buffer hit rate for reads") 2044 .precision(2); 2045 2046 readRowHitRate = (readRowHits / (readBursts - servicedByWrQ)) * 100; 2047 2048 writeRowHitRate 2049 .name(name() + ".writeRowHitRate") 2050 .desc("Row buffer hit rate for writes") 2051 .precision(2); 2052 2053 writeRowHitRate = (writeRowHits / (writeBursts - mergedWrBursts)) * 100; 2054 2055 readPktSize 2056 .init(ceilLog2(burstSize) + 1) 2057 .name(name() + ".readPktSize") 2058 .desc("Read request sizes (log2)"); 2059 2060 writePktSize 2061 .init(ceilLog2(burstSize) + 1) 2062 .name(name() + ".writePktSize") 2063 .desc("Write request sizes (log2)"); 2064 2065 rdQLenPdf 2066 .init(readBufferSize) 2067 .name(name() + ".rdQLenPdf") 2068 .desc("What read queue length does an incoming req see"); 2069 2070 wrQLenPdf 2071 .init(writeBufferSize) 2072 .name(name() + ".wrQLenPdf") 2073 .desc("What write queue length does an incoming req see"); 2074 2075 bytesPerActivate 2076 .init(maxAccessesPerRow) 2077 .name(name() + ".bytesPerActivate") 2078 .desc("Bytes accessed per row activation") 2079 .flags(nozero); 2080 2081 rdPerTurnAround 2082 .init(readBufferSize) 2083 .name(name() + ".rdPerTurnAround") 2084 .desc("Reads before turning the bus around for writes") 2085 .flags(nozero); 2086 2087 wrPerTurnAround 2088 .init(writeBufferSize) 2089 .name(name() + ".wrPerTurnAround") 2090 .desc("Writes before turning the bus around for reads") 2091 .flags(nozero); 2092 2093 bytesReadDRAM 2094 .name(name() + ".bytesReadDRAM") 2095 .desc("Total number of bytes read from DRAM"); 2096 2097 bytesReadWrQ 2098 .name(name() + ".bytesReadWrQ") 2099 .desc("Total number of bytes read from write queue"); 2100 2101 bytesWritten 2102 .name(name() + ".bytesWritten") 2103 .desc("Total number of bytes written to DRAM"); 2104 2105 bytesReadSys 2106 .name(name() + ".bytesReadSys") 2107 .desc("Total read bytes from the system interface side"); 2108 2109 bytesWrittenSys 2110 .name(name() + ".bytesWrittenSys") 2111 .desc("Total written bytes from the system interface side"); 2112 2113 avgRdBW 2114 .name(name() + ".avgRdBW") 2115 .desc("Average DRAM read bandwidth in MiByte/s") 2116 .precision(2); 2117 2118 avgRdBW = (bytesReadDRAM / 1000000) / simSeconds; 2119 2120 avgWrBW 2121 .name(name() + ".avgWrBW") 2122 .desc("Average achieved write bandwidth in MiByte/s") 2123 .precision(2); 2124 2125 avgWrBW = (bytesWritten / 1000000) / simSeconds; 2126 2127 avgRdBWSys 2128 .name(name() + ".avgRdBWSys") 2129 .desc("Average system read bandwidth in MiByte/s") 2130 .precision(2); 2131 2132 avgRdBWSys = (bytesReadSys / 1000000) / simSeconds; 2133 2134 avgWrBWSys 2135 .name(name() + ".avgWrBWSys") 2136 .desc("Average system write bandwidth in MiByte/s") 2137 .precision(2); 2138 2139 avgWrBWSys = (bytesWrittenSys / 1000000) / simSeconds; 2140 2141 peakBW 2142 .name(name() + ".peakBW") 2143 .desc("Theoretical peak bandwidth in MiByte/s") 2144 .precision(2); 2145 2146 peakBW = (SimClock::Frequency / tBURST) * burstSize / 1000000; 2147 2148 busUtil 2149 .name(name() + ".busUtil") 2150 .desc("Data bus utilization in percentage") 2151 .precision(2); 2152 busUtil = (avgRdBW + avgWrBW) / peakBW * 100; 2153 2154 totGap 2155 .name(name() + ".totGap") 2156 .desc("Total gap between requests"); 2157 2158 avgGap 2159 .name(name() + ".avgGap") 2160 .desc("Average gap between requests") 2161 .precision(2); 2162 2163 avgGap = totGap / (readReqs + writeReqs); 2164 2165 // Stats for DRAM Power calculation based on Micron datasheet 2166 busUtilRead 2167 .name(name() + ".busUtilRead") 2168 .desc("Data bus utilization in percentage for reads") 2169 .precision(2); 2170 2171 busUtilRead = avgRdBW / peakBW * 100; 2172 2173 busUtilWrite 2174 .name(name() + ".busUtilWrite") 2175 .desc("Data bus utilization in percentage for writes") 2176 .precision(2); 2177 2178 busUtilWrite = avgWrBW / peakBW * 100; 2179 2180 pageHitRate 2181 .name(name() + ".pageHitRate") 2182 .desc("Row buffer hit rate, read and write combined") 2183 .precision(2); 2184 2185 pageHitRate = (writeRowHits + readRowHits) / 2186 (writeBursts - mergedWrBursts + readBursts - servicedByWrQ) * 100; 2187} 2188 2189void 2190DRAMCtrl::recvFunctional(PacketPtr pkt) 2191{ 2192 // rely on the abstract memory 2193 functionalAccess(pkt); 2194} 2195 2196BaseSlavePort& 2197DRAMCtrl::getSlavePort(const string &if_name, PortID idx) 2198{ 2199 if (if_name != "port") { 2200 return MemObject::getSlavePort(if_name, idx); 2201 } else { 2202 return port; 2203 } 2204} 2205 2206DrainState 2207DRAMCtrl::drain() 2208{ 2209 // if there is anything in any of our internal queues, keep track 2210 // of that as well 2211 if (!(writeQueue.empty() && readQueue.empty() && respQueue.empty() && 2212 allRanksDrained())) { 2213 2214 DPRINTF(Drain, "DRAM controller not drained, write: %d, read: %d," 2215 " resp: %d\n", writeQueue.size(), readQueue.size(), 2216 respQueue.size()); 2217
| 2352 registerDumpCallback(new RankDumpCallback(this)); 2353} 2354void 2355DRAMCtrl::regStats() 2356{ 2357 using namespace Stats; 2358 2359 AbstractMemory::regStats(); 2360 2361 for (auto r : ranks) { 2362 r->regStats(); 2363 } 2364 2365 readReqs 2366 .name(name() + ".readReqs") 2367 .desc("Number of read requests accepted"); 2368 2369 writeReqs 2370 .name(name() + ".writeReqs") 2371 .desc("Number of write requests accepted"); 2372 2373 readBursts 2374 .name(name() + ".readBursts") 2375 .desc("Number of DRAM read bursts, " 2376 "including those serviced by the write queue"); 2377 2378 writeBursts 2379 .name(name() + ".writeBursts") 2380 .desc("Number of DRAM write bursts, " 2381 "including those merged in the write queue"); 2382 2383 servicedByWrQ 2384 .name(name() + ".servicedByWrQ") 2385 .desc("Number of DRAM read bursts serviced by the write queue"); 2386 2387 mergedWrBursts 2388 .name(name() + ".mergedWrBursts") 2389 .desc("Number of DRAM write bursts merged with an existing one"); 2390 2391 neitherReadNorWrite 2392 .name(name() + ".neitherReadNorWriteReqs") 2393 .desc("Number of requests that are neither read nor write"); 2394 2395 perBankRdBursts 2396 .init(banksPerRank * ranksPerChannel) 2397 .name(name() + ".perBankRdBursts") 2398 .desc("Per bank write bursts"); 2399 2400 perBankWrBursts 2401 .init(banksPerRank * ranksPerChannel) 2402 .name(name() + ".perBankWrBursts") 2403 .desc("Per bank write bursts"); 2404 2405 avgRdQLen 2406 .name(name() + ".avgRdQLen") 2407 .desc("Average read queue length when enqueuing") 2408 .precision(2); 2409 2410 avgWrQLen 2411 .name(name() + ".avgWrQLen") 2412 .desc("Average write queue length when enqueuing") 2413 .precision(2); 2414 2415 totQLat 2416 .name(name() + ".totQLat") 2417 .desc("Total ticks spent queuing"); 2418 2419 totBusLat 2420 .name(name() + ".totBusLat") 2421 .desc("Total ticks spent in databus transfers"); 2422 2423 totMemAccLat 2424 .name(name() + ".totMemAccLat") 2425 .desc("Total ticks spent from burst creation until serviced " 2426 "by the DRAM"); 2427 2428 avgQLat 2429 .name(name() + ".avgQLat") 2430 .desc("Average queueing delay per DRAM burst") 2431 .precision(2); 2432 2433 avgQLat = totQLat / (readBursts - servicedByWrQ); 2434 2435 avgBusLat 2436 .name(name() + ".avgBusLat") 2437 .desc("Average bus latency per DRAM burst") 2438 .precision(2); 2439 2440 avgBusLat = totBusLat / (readBursts - servicedByWrQ); 2441 2442 avgMemAccLat 2443 .name(name() + ".avgMemAccLat") 2444 .desc("Average memory access latency per DRAM burst") 2445 .precision(2); 2446 2447 avgMemAccLat = totMemAccLat / (readBursts - servicedByWrQ); 2448 2449 numRdRetry 2450 .name(name() + ".numRdRetry") 2451 .desc("Number of times read queue was full causing retry"); 2452 2453 numWrRetry 2454 .name(name() + ".numWrRetry") 2455 .desc("Number of times write queue was full causing retry"); 2456 2457 readRowHits 2458 .name(name() + ".readRowHits") 2459 .desc("Number of row buffer hits during reads"); 2460 2461 writeRowHits 2462 .name(name() + ".writeRowHits") 2463 .desc("Number of row buffer hits during writes"); 2464 2465 readRowHitRate 2466 .name(name() + ".readRowHitRate") 2467 .desc("Row buffer hit rate for reads") 2468 .precision(2); 2469 2470 readRowHitRate = (readRowHits / (readBursts - servicedByWrQ)) * 100; 2471 2472 writeRowHitRate 2473 .name(name() + ".writeRowHitRate") 2474 .desc("Row buffer hit rate for writes") 2475 .precision(2); 2476 2477 writeRowHitRate = (writeRowHits / (writeBursts - mergedWrBursts)) * 100; 2478 2479 readPktSize 2480 .init(ceilLog2(burstSize) + 1) 2481 .name(name() + ".readPktSize") 2482 .desc("Read request sizes (log2)"); 2483 2484 writePktSize 2485 .init(ceilLog2(burstSize) + 1) 2486 .name(name() + ".writePktSize") 2487 .desc("Write request sizes (log2)"); 2488 2489 rdQLenPdf 2490 .init(readBufferSize) 2491 .name(name() + ".rdQLenPdf") 2492 .desc("What read queue length does an incoming req see"); 2493 2494 wrQLenPdf 2495 .init(writeBufferSize) 2496 .name(name() + ".wrQLenPdf") 2497 .desc("What write queue length does an incoming req see"); 2498 2499 bytesPerActivate 2500 .init(maxAccessesPerRow) 2501 .name(name() + ".bytesPerActivate") 2502 .desc("Bytes accessed per row activation") 2503 .flags(nozero); 2504 2505 rdPerTurnAround 2506 .init(readBufferSize) 2507 .name(name() + ".rdPerTurnAround") 2508 .desc("Reads before turning the bus around for writes") 2509 .flags(nozero); 2510 2511 wrPerTurnAround 2512 .init(writeBufferSize) 2513 .name(name() + ".wrPerTurnAround") 2514 .desc("Writes before turning the bus around for reads") 2515 .flags(nozero); 2516 2517 bytesReadDRAM 2518 .name(name() + ".bytesReadDRAM") 2519 .desc("Total number of bytes read from DRAM"); 2520 2521 bytesReadWrQ 2522 .name(name() + ".bytesReadWrQ") 2523 .desc("Total number of bytes read from write queue"); 2524 2525 bytesWritten 2526 .name(name() + ".bytesWritten") 2527 .desc("Total number of bytes written to DRAM"); 2528 2529 bytesReadSys 2530 .name(name() + ".bytesReadSys") 2531 .desc("Total read bytes from the system interface side"); 2532 2533 bytesWrittenSys 2534 .name(name() + ".bytesWrittenSys") 2535 .desc("Total written bytes from the system interface side"); 2536 2537 avgRdBW 2538 .name(name() + ".avgRdBW") 2539 .desc("Average DRAM read bandwidth in MiByte/s") 2540 .precision(2); 2541 2542 avgRdBW = (bytesReadDRAM / 1000000) / simSeconds; 2543 2544 avgWrBW 2545 .name(name() + ".avgWrBW") 2546 .desc("Average achieved write bandwidth in MiByte/s") 2547 .precision(2); 2548 2549 avgWrBW = (bytesWritten / 1000000) / simSeconds; 2550 2551 avgRdBWSys 2552 .name(name() + ".avgRdBWSys") 2553 .desc("Average system read bandwidth in MiByte/s") 2554 .precision(2); 2555 2556 avgRdBWSys = (bytesReadSys / 1000000) / simSeconds; 2557 2558 avgWrBWSys 2559 .name(name() + ".avgWrBWSys") 2560 .desc("Average system write bandwidth in MiByte/s") 2561 .precision(2); 2562 2563 avgWrBWSys = (bytesWrittenSys / 1000000) / simSeconds; 2564 2565 peakBW 2566 .name(name() + ".peakBW") 2567 .desc("Theoretical peak bandwidth in MiByte/s") 2568 .precision(2); 2569 2570 peakBW = (SimClock::Frequency / tBURST) * burstSize / 1000000; 2571 2572 busUtil 2573 .name(name() + ".busUtil") 2574 .desc("Data bus utilization in percentage") 2575 .precision(2); 2576 busUtil = (avgRdBW + avgWrBW) / peakBW * 100; 2577 2578 totGap 2579 .name(name() + ".totGap") 2580 .desc("Total gap between requests"); 2581 2582 avgGap 2583 .name(name() + ".avgGap") 2584 .desc("Average gap between requests") 2585 .precision(2); 2586 2587 avgGap = totGap / (readReqs + writeReqs); 2588 2589 // Stats for DRAM Power calculation based on Micron datasheet 2590 busUtilRead 2591 .name(name() + ".busUtilRead") 2592 .desc("Data bus utilization in percentage for reads") 2593 .precision(2); 2594 2595 busUtilRead = avgRdBW / peakBW * 100; 2596 2597 busUtilWrite 2598 .name(name() + ".busUtilWrite") 2599 .desc("Data bus utilization in percentage for writes") 2600 .precision(2); 2601 2602 busUtilWrite = avgWrBW / peakBW * 100; 2603 2604 pageHitRate 2605 .name(name() + ".pageHitRate") 2606 .desc("Row buffer hit rate, read and write combined") 2607 .precision(2); 2608 2609 pageHitRate = (writeRowHits + readRowHits) / 2610 (writeBursts - mergedWrBursts + readBursts - servicedByWrQ) * 100; 2611} 2612 2613void 2614DRAMCtrl::recvFunctional(PacketPtr pkt) 2615{ 2616 // rely on the abstract memory 2617 functionalAccess(pkt); 2618} 2619 2620BaseSlavePort& 2621DRAMCtrl::getSlavePort(const string &if_name, PortID idx) 2622{ 2623 if (if_name != "port") { 2624 return MemObject::getSlavePort(if_name, idx); 2625 } else { 2626 return port; 2627 } 2628} 2629 2630DrainState 2631DRAMCtrl::drain() 2632{ 2633 // if there is anything in any of our internal queues, keep track 2634 // of that as well 2635 if (!(writeQueue.empty() && readQueue.empty() && respQueue.empty() && 2636 allRanksDrained())) { 2637 2638 DPRINTF(Drain, "DRAM controller not drained, write: %d, read: %d," 2639 " resp: %d\n", writeQueue.size(), readQueue.size(), 2640 respQueue.size()); 2641
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2218 // the only part that is not drained automatically over time
| 2642 // the only queue that is not drained automatically over time
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2219 // is the write queue, thus kick things into action if needed 2220 if (!writeQueue.empty() && !nextReqEvent.scheduled()) { 2221 schedule(nextReqEvent, curTick()); 2222 }
| 2643 // is the write queue, thus kick things into action if needed 2644 if (!writeQueue.empty() && !nextReqEvent.scheduled()) { 2645 schedule(nextReqEvent, curTick()); 2646 }
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| 2647 2648 // also need to kick off events to exit self-refresh 2649 for (auto r : ranks) { 2650 // force self-refresh exit, which in turn will issue auto-refresh 2651 if (r->pwrState == PWR_SREF) { 2652 DPRINTF(DRAM,"Rank%d: Forcing self-refresh wakeup in drain\n", 2653 r->rank); 2654 r->scheduleWakeUpEvent(tXS); 2655 } 2656 } 2657
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2223 return DrainState::Draining; 2224 } else { 2225 return DrainState::Drained; 2226 } 2227} 2228 2229bool 2230DRAMCtrl::allRanksDrained() const 2231{ 2232 // true until proven false 2233 bool all_ranks_drained = true; 2234 for (auto r : ranks) { 2235 // then verify that the power state is IDLE 2236 // ensuring all banks are closed and rank is not in a low power state 2237 all_ranks_drained = r->inPwrIdleState() && all_ranks_drained; 2238 } 2239 return all_ranks_drained; 2240} 2241 2242void 2243DRAMCtrl::drainResume() 2244{ 2245 if (!isTimingMode && system()->isTimingMode()) { 2246 // if we switched to timing mode, kick things into action, 2247 // and behave as if we restored from a checkpoint 2248 startup(); 2249 } else if (isTimingMode && !system()->isTimingMode()) { 2250 // if we switch from timing mode, stop the refresh events to 2251 // not cause issues with KVM 2252 for (auto r : ranks) { 2253 r->suspend(); 2254 } 2255 } 2256 2257 // update the mode 2258 isTimingMode = system()->isTimingMode(); 2259} 2260 2261DRAMCtrl::MemoryPort::MemoryPort(const std::string& name, DRAMCtrl& _memory) 2262 : QueuedSlavePort(name, &_memory, queue), queue(_memory, *this), 2263 memory(_memory) 2264{ } 2265 2266AddrRangeList 2267DRAMCtrl::MemoryPort::getAddrRanges() const 2268{ 2269 AddrRangeList ranges; 2270 ranges.push_back(memory.getAddrRange()); 2271 return ranges; 2272} 2273 2274void 2275DRAMCtrl::MemoryPort::recvFunctional(PacketPtr pkt) 2276{ 2277 pkt->pushLabel(memory.name()); 2278 2279 if (!queue.checkFunctional(pkt)) { 2280 // Default implementation of SimpleTimingPort::recvFunctional() 2281 // calls recvAtomic() and throws away the latency; we can save a 2282 // little here by just not calculating the latency. 2283 memory.recvFunctional(pkt); 2284 } 2285 2286 pkt->popLabel(); 2287} 2288 2289Tick 2290DRAMCtrl::MemoryPort::recvAtomic(PacketPtr pkt) 2291{ 2292 return memory.recvAtomic(pkt); 2293} 2294 2295bool 2296DRAMCtrl::MemoryPort::recvTimingReq(PacketPtr pkt) 2297{ 2298 // pass it to the memory controller 2299 return memory.recvTimingReq(pkt); 2300} 2301 2302DRAMCtrl* 2303DRAMCtrlParams::create() 2304{ 2305 return new DRAMCtrl(this); 2306}
| 2658 return DrainState::Draining; 2659 } else { 2660 return DrainState::Drained; 2661 } 2662} 2663 2664bool 2665DRAMCtrl::allRanksDrained() const 2666{ 2667 // true until proven false 2668 bool all_ranks_drained = true; 2669 for (auto r : ranks) { 2670 // then verify that the power state is IDLE 2671 // ensuring all banks are closed and rank is not in a low power state 2672 all_ranks_drained = r->inPwrIdleState() && all_ranks_drained; 2673 } 2674 return all_ranks_drained; 2675} 2676 2677void 2678DRAMCtrl::drainResume() 2679{ 2680 if (!isTimingMode && system()->isTimingMode()) { 2681 // if we switched to timing mode, kick things into action, 2682 // and behave as if we restored from a checkpoint 2683 startup(); 2684 } else if (isTimingMode && !system()->isTimingMode()) { 2685 // if we switch from timing mode, stop the refresh events to 2686 // not cause issues with KVM 2687 for (auto r : ranks) { 2688 r->suspend(); 2689 } 2690 } 2691 2692 // update the mode 2693 isTimingMode = system()->isTimingMode(); 2694} 2695 2696DRAMCtrl::MemoryPort::MemoryPort(const std::string& name, DRAMCtrl& _memory) 2697 : QueuedSlavePort(name, &_memory, queue), queue(_memory, *this), 2698 memory(_memory) 2699{ } 2700 2701AddrRangeList 2702DRAMCtrl::MemoryPort::getAddrRanges() const 2703{ 2704 AddrRangeList ranges; 2705 ranges.push_back(memory.getAddrRange()); 2706 return ranges; 2707} 2708 2709void 2710DRAMCtrl::MemoryPort::recvFunctional(PacketPtr pkt) 2711{ 2712 pkt->pushLabel(memory.name()); 2713 2714 if (!queue.checkFunctional(pkt)) { 2715 // Default implementation of SimpleTimingPort::recvFunctional() 2716 // calls recvAtomic() and throws away the latency; we can save a 2717 // little here by just not calculating the latency. 2718 memory.recvFunctional(pkt); 2719 } 2720 2721 pkt->popLabel(); 2722} 2723 2724Tick 2725DRAMCtrl::MemoryPort::recvAtomic(PacketPtr pkt) 2726{ 2727 return memory.recvAtomic(pkt); 2728} 2729 2730bool 2731DRAMCtrl::MemoryPort::recvTimingReq(PacketPtr pkt) 2732{ 2733 // pass it to the memory controller 2734 return memory.recvTimingReq(pkt); 2735} 2736 2737DRAMCtrl* 2738DRAMCtrlParams::create() 2739{ 2740 return new DRAMCtrl(this); 2741}
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