1/* |
2 * Copyright (c) 2012-2013 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 --- 33 unchanged lines hidden (view full) --- 44/** 45 * @file 46 * SimpleMemory declaration 47 */ 48 49#ifndef __SIMPLE_MEMORY_HH__ 50#define __SIMPLE_MEMORY_HH__ 51 |
52#include <deque> 53 |
54#include "mem/abstract_mem.hh" |
55#include "mem/port.hh" |
56#include "params/SimpleMemory.hh" 57 58/** 59 * The simple memory is a basic single-ported memory controller with |
60 * a configurable throughput and latency. 61 * |
62 * @sa \ref gem5MemorySystem "gem5 Memory System" 63 */ 64class SimpleMemory : public AbstractMemory 65{ 66 67 private: 68 |
69 /** 70 * A deferred packet stores a packet along with its scheduled 71 * transmission time 72 */ 73 class DeferredPacket |
74 { 75 |
76 public: 77 78 const Tick tick; 79 const PacketPtr pkt; 80 81 DeferredPacket(PacketPtr _pkt, Tick _tick) : tick(_tick), pkt(_pkt) 82 { } 83 }; 84 85 class MemoryPort : public SlavePort 86 { 87 |
88 private: 89 |
90 SimpleMemory& memory; 91 92 public: 93 94 MemoryPort(const std::string& _name, SimpleMemory& _memory); 95 96 protected: 97 98 Tick recvAtomic(PacketPtr pkt); 99 100 void recvFunctional(PacketPtr pkt); 101 102 bool recvTimingReq(PacketPtr pkt); 103 |
104 void recvRetry(); 105 |
106 AddrRangeList getAddrRanges() const; 107 108 }; 109 110 MemoryPort port; 111 |
112 /** 113 * Latency from that a request is accepted until the response is 114 * ready to be sent. 115 */ 116 const Tick latency; |
117 |
118 /** 119 * Fudge factor added to the latency. 120 */ 121 const Tick latency_var; 122 123 /** 124 * Internal (unbounded) storage to mimic the delay caused by the 125 * actual memory access. Note that this is where the packet spends 126 * the memory latency. 127 */ 128 std::deque<DeferredPacket> packetQueue; 129 130 /** 131 * Bandwidth in ticks per byte. The regulation affects the 132 * acceptance rate of requests and the queueing takes place after 133 * the regulation. 134 */ |
135 const double bandwidth; 136 137 /** 138 * Track the state of the memory as either idle or busy, no need 139 * for an enum with only two states. 140 */ 141 bool isBusy; 142 143 /** 144 * Remember if we have to retry an outstanding request that 145 * arrived while we were busy. 146 */ 147 bool retryReq; 148 149 /** |
150 * Remember if we failed to send a response and are awaiting a 151 * retry. This is only used as a check. 152 */ 153 bool retryResp; 154 155 /** |
156 * Release the memory after being busy and send a retry if a 157 * request was rejected in the meanwhile. 158 */ 159 void release(); 160 161 EventWrapper<SimpleMemory, &SimpleMemory::release> releaseEvent; 162 |
163 /** 164 * Dequeue a packet from our internal packet queue and move it to 165 * the port where it will be sent as soon as possible. 166 */ 167 void dequeue(); 168 169 EventWrapper<SimpleMemory, &SimpleMemory::dequeue> dequeueEvent; 170 171 /** 172 * Detemine the latency. 173 * 174 * @return the latency seen by the current packet 175 */ 176 Tick getLatency() const; 177 |
178 /** @todo this is a temporary workaround until the 4-phase code is 179 * committed. upstream caches needs this packet until true is returned, so 180 * hold onto it for deletion until a subsequent call 181 */ 182 std::vector<PacketPtr> pendingDelete; 183 |
184 /** 185 * If we need to drain, keep the drain manager around until we're 186 * done here. 187 */ 188 DrainManager *drainManager; 189 |
190 public: 191 192 SimpleMemory(const SimpleMemoryParams *p); |
193 194 unsigned int drain(DrainManager *dm); 195 |
196 BaseSlavePort& getSlavePort(const std::string& if_name, 197 PortID idx = InvalidPortID); 198 void init(); |
199 200 protected: 201 |
202 Tick recvAtomic(PacketPtr pkt); 203 204 void recvFunctional(PacketPtr pkt); 205 |
206 bool recvTimingReq(PacketPtr pkt); |
207 |
208 void recvRetry(); 209 |
210}; 211 212#endif //__SIMPLE_MEMORY_HH__ |