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Diffstat (limited to 'src/mem/ruby/structures/BankedArray.cc')
-rw-r--r-- | src/mem/ruby/structures/BankedArray.cc | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/src/mem/ruby/structures/BankedArray.cc b/src/mem/ruby/structures/BankedArray.cc new file mode 100644 index 000000000..0644ffe8b --- /dev/null +++ b/src/mem/ruby/structures/BankedArray.cc @@ -0,0 +1,85 @@ +/* + * Copyright (c) 2012 Advanced Micro Devices, Inc. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer; + * redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution; + * neither the name of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Author: Brad Beckmann + * + */ + +#include "base/intmath.hh" +#include "mem/ruby/structures/BankedArray.hh" +#include "mem/ruby/system/System.hh" + +BankedArray::BankedArray(unsigned int banks, Cycles accessLatency, + unsigned int startIndexBit) +{ + this->banks = banks; + this->accessLatency = accessLatency; + this->startIndexBit = startIndexBit; + + if (banks != 0) { + bankBits = floorLog2(banks); + } + + busyBanks.resize(banks); +} + +bool +BankedArray::tryAccess(Index idx) +{ + if (accessLatency == 0) + return true; + + unsigned int bank = mapIndexToBank(idx); + assert(bank < banks); + + if (busyBanks[bank].endAccess >= curTick()) { + if (!(busyBanks[bank].startAccess == curTick() && + busyBanks[bank].idx == idx)) { + return false; + } else { + // We tried to allocate resources twice + // in the same cycle for the same addr + return true; + } + } + + busyBanks[bank].idx = idx; + busyBanks[bank].startAccess = curTick(); + busyBanks[bank].endAccess = curTick() + + (accessLatency-1) * g_system_ptr->clockPeriod(); + + return true; +} + +unsigned int +BankedArray::mapIndexToBank(Index idx) +{ + if (banks == 1) { + return 0; + } + return idx % banks; +} |