| /* |
| * Copyright (c) 2012-2013 ARM Limited |
| * All rights reserved |
| * |
| * The license below extends only to copyright in the software and shall |
| * not be construed as granting a license to any other intellectual |
| * property including but not limited to intellectual property relating |
| * to a hardware implementation of the functionality of the software |
| * licensed hereunder. You may use the software subject to the license |
| * terms below provided that you ensure that this notice is replicated |
| * unmodified and in its entirety in all distributions of the software, |
| * modified or unmodified, in source code or in binary form. |
| * |
| * Copyright (c) 2001-2005 The Regents of The University of Michigan |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are |
| * met: redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer; |
| * redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution; |
| * neither the name of the copyright holders nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| /** |
| * @file |
| * SimpleMemory declaration |
| */ |
| |
| #ifndef __MEM_SIMPLE_MEMORY_HH__ |
| #define __MEM_SIMPLE_MEMORY_HH__ |
| |
| #include <list> |
| |
| #include "mem/abstract_mem.hh" |
| #include "mem/port.hh" |
| #include "params/SimpleMemory.hh" |
| |
| namespace gem5 |
| { |
| |
| namespace memory |
| { |
| |
| /** |
| * The simple memory is a basic single-ported memory controller with |
| * a configurable throughput and latency. |
| * |
| * @sa \ref gem5MemorySystem "gem5 Memory System" |
| */ |
| class SimpleMemory : public AbstractMemory |
| { |
| |
| private: |
| |
| /** |
| * A deferred packet stores a packet along with its scheduled |
| * transmission time |
| */ |
| class DeferredPacket |
| { |
| |
| public: |
| |
| const Tick tick; |
| const PacketPtr pkt; |
| |
| DeferredPacket(PacketPtr _pkt, Tick _tick) : tick(_tick), pkt(_pkt) |
| { } |
| }; |
| |
| class MemoryPort : public ResponsePort |
| { |
| private: |
| SimpleMemory& mem; |
| |
| public: |
| MemoryPort(const std::string& _name, SimpleMemory& _memory); |
| |
| protected: |
| Tick recvAtomic(PacketPtr pkt) override; |
| Tick recvAtomicBackdoor( |
| PacketPtr pkt, MemBackdoorPtr &_backdoor) override; |
| void recvFunctional(PacketPtr pkt) override; |
| void recvMemBackdoorReq(const MemBackdoorReq &req, |
| MemBackdoorPtr &backdoor) override; |
| bool recvTimingReq(PacketPtr pkt) override; |
| void recvRespRetry() override; |
| AddrRangeList getAddrRanges() const override; |
| }; |
| |
| MemoryPort port; |
| |
| /** |
| * Latency from that a request is accepted until the response is |
| * ready to be sent. |
| */ |
| const Tick latency; |
| |
| /** |
| * Fudge factor added to the latency. |
| */ |
| const Tick latency_var; |
| |
| /** |
| * Internal (unbounded) storage to mimic the delay caused by the |
| * actual memory access. Note that this is where the packet spends |
| * the memory latency. |
| */ |
| std::list<DeferredPacket> packetQueue; |
| |
| /** |
| * Bandwidth in ticks per byte. The regulation affects the |
| * acceptance rate of requests and the queueing takes place after |
| * the regulation. |
| */ |
| const double bandwidth; |
| |
| /** |
| * Track the state of the memory as either idle or busy, no need |
| * for an enum with only two states. |
| */ |
| bool isBusy; |
| |
| /** |
| * Remember if we have to retry an outstanding request that |
| * arrived while we were busy. |
| */ |
| bool retryReq; |
| |
| /** |
| * Remember if we failed to send a response and are awaiting a |
| * retry. This is only used as a check. |
| */ |
| bool retryResp; |
| |
| /** |
| * Release the memory after being busy and send a retry if a |
| * request was rejected in the meanwhile. |
| */ |
| void release(); |
| |
| EventFunctionWrapper releaseEvent; |
| |
| /** |
| * Dequeue a packet from our internal packet queue and move it to |
| * the port where it will be sent as soon as possible. |
| */ |
| void dequeue(); |
| |
| EventFunctionWrapper dequeueEvent; |
| |
| /** |
| * Detemine the latency. |
| * |
| * @return the latency seen by the current packet |
| */ |
| Tick getLatency() const; |
| |
| /** |
| * Upstream caches need this packet until true is returned, so |
| * hold it for deletion until a subsequent call |
| */ |
| std::unique_ptr<Packet> pendingDelete; |
| |
| public: |
| |
| SimpleMemory(const SimpleMemoryParams &p); |
| |
| DrainState drain() override; |
| |
| Port &getPort(const std::string &if_name, |
| PortID idx=InvalidPortID) override; |
| void init() override; |
| |
| protected: |
| Tick recvAtomic(PacketPtr pkt); |
| Tick recvAtomicBackdoor(PacketPtr pkt, MemBackdoorPtr &_backdoor); |
| void recvFunctional(PacketPtr pkt); |
| void recvMemBackdoorReq(const MemBackdoorReq &req, |
| MemBackdoorPtr &backdoor); |
| bool recvTimingReq(PacketPtr pkt); |
| void recvRespRetry(); |
| }; |
| |
| } // namespace memory |
| } // namespace gem5 |
| |
| #endif //__MEM_SIMPLE_MEMORY_HH__ |