1/*
2 * Copyright (c) 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
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 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions are
16 * met: redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer;
18 * redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution;
21 * neither the name of the copyright holders nor the names of its
22 * contributors may be used to endorse or promote products derived from
23 * this software without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
26 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
27 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
28 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
29 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
30 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
31 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
35 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36 *
37 * Authors: Andreas Hansson
38 */
39
40/**
41 * @file
42 * DRAMSim2
43 */
44#ifndef __MEM_DRAMSIM2_HH__
45#define __MEM_DRAMSIM2_HH__
46
47#include <queue>
48#include <unordered_map>
49
50#include "mem/abstract_mem.hh"
51#include "mem/dramsim2_wrapper.hh"
52#include "mem/qport.hh"
53#include "params/DRAMSim2.hh"
54
55class DRAMSim2 : public AbstractMemory
56{
57  private:
58
59    /**
60     * The memory port has to deal with its own flow control to avoid
61     * having unbounded storage that is implicitly created in the port
62     * itself.
63     */
64    class MemoryPort : public SlavePort
65    {
66
67      private:
68
69        DRAMSim2& memory;
70
71      public:
72
73        MemoryPort(const std::string& _name, DRAMSim2& _memory);
74
75      protected:
76
77        Tick recvAtomic(PacketPtr pkt);
78
79        void recvFunctional(PacketPtr pkt);
80
81        bool recvTimingReq(PacketPtr pkt);
82
83        void recvRespRetry();
84
85        AddrRangeList getAddrRanges() const;
86
87    };
88
89    MemoryPort port;
90
91    /**
92     * The actual DRAMSim2 wrapper
93     */
94    DRAMSim2Wrapper wrapper;
95
96    /**
97     * Is the connected port waiting for a retry from us
98     */
99    bool retryReq;
100
101    /**
102     * Are we waiting for a retry for sending a response.
103     */
104    bool retryResp;
105
106    /**
107     * Keep track of when the wrapper is started.
108     */
109    Tick startTick;
110
111    /**
112     * Keep track of what packets are outstanding per
113     * address, and do so separately for reads and writes. This is
114     * done so that we can return the right packet on completion from
115     * DRAMSim.
116     */
117    std::unordered_map<Addr, std::queue<PacketPtr> > outstandingReads;
118    std::unordered_map<Addr, std::queue<PacketPtr> > outstandingWrites;
119
120    /**
121     * Count the number of outstanding transactions so that we can
122     * block any further requests until there is space in DRAMSim2 and
123     * the sending queue we need to buffer the response packets.
124     */
125    unsigned int nbrOutstandingReads;
126    unsigned int nbrOutstandingWrites;
127
128    /**
129     * Queue to hold response packets until we can send them
130     * back. This is needed as DRAMSim2 unconditionally passes
131     * responses back without any flow control.
132     */
133    std::deque<PacketPtr> responseQueue;
134
135    unsigned int nbrOutstanding() const;
136
137    /**
138     * When a packet is ready, use the "access()" method in
139     * AbstractMemory to actually create the response packet, and send
140     * it back to the outside world requestor.
141     *
142     * @param pkt The packet from the outside world
143     */
144    void accessAndRespond(PacketPtr pkt);
145
146    void sendResponse();
147
148    /**
149     * Event to schedule sending of responses
150     */
151    EventFunctionWrapper sendResponseEvent;
152
153    /**
154     * Progress the controller one clock cycle.
155     */
156    void tick();
157
158    /**
159     * Event to schedule clock ticks
160     */
161    EventFunctionWrapper tickEvent;
162
163    /**
164     * Upstream caches need this packet until true is returned, so
165     * hold it for deletion until a subsequent call
166     */
167    std::unique_ptr<Packet> pendingDelete;
168
169  public:
170
171    typedef DRAMSim2Params Params;
172    DRAMSim2(const Params *p);
173
174    /**
175     * Read completion callback.
176     *
177     * @param id Channel id of the responder
178     * @param addr Address of the request
179     * @param cycle Internal cycle count of DRAMSim2
180     */
181    void readComplete(unsigned id, uint64_t addr, uint64_t cycle);
182
183    /**
184     * Write completion callback.
185     *
186     * @param id Channel id of the responder
187     * @param addr Address of the request
188     * @param cycle Internal cycle count of DRAMSim2
189     */
190    void writeComplete(unsigned id, uint64_t addr, uint64_t cycle);
191
192    DrainState drain() override;
193
194    Port &getPort(const std::string &if_name,
195                  PortID idx=InvalidPortID) override;
196
197    void init() override;
198    void startup() override;
199
200  protected:
201
202    Tick recvAtomic(PacketPtr pkt);
203    void recvFunctional(PacketPtr pkt);
204    bool recvTimingReq(PacketPtr pkt);
205    void recvRespRetry();
206
207};
208
209#endif // __MEM_DRAMSIM2_HH__
210