timing.hh revision 8737 
1/*
2 * Copyright (c) 2002-2005 The Regents of The University of Michigan
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Steve Reinhardt
29 */
30
31#ifndef __CPU_SIMPLE_TIMING_HH__
32#define __CPU_SIMPLE_TIMING_HH__
33
34#include "cpu/simple/base.hh"
35#include "cpu/translation.hh"
36#include "params/TimingSimpleCPU.hh"
37
38class TimingSimpleCPU : public BaseSimpleCPU
39{
40  public:
41
42    TimingSimpleCPU(TimingSimpleCPUParams * params);
43    virtual ~TimingSimpleCPU();
44
45    virtual void init();
46
47  public:
48    Event *drainEvent;
49
50  private:
51
52    /*
53     * If an access needs to be broken into fragments, currently at most two,
54     * the the following two classes are used as the sender state of the
55     * packets so the CPU can keep track of everything. In the main packet
56     * sender state, there's an array with a spot for each fragment. If a
57     * fragment has already been accepted by the CPU, aka isn't waiting for
58     * a retry, it's pointer is NULL. After each fragment has successfully
59     * been processed, the "outstanding" counter is decremented. Once the
60     * count is zero, the entire larger access is complete.
61     */
62    class SplitMainSenderState : public Packet::SenderState
63    {
64      public:
65        int outstanding;
66        PacketPtr fragments[2];
67
68        int
69        getPendingFragment()
70        {
71            if (fragments[0]) {
72                return 0;
73            } else if (fragments[1]) {
74                return 1;
75            } else {
76                return -1;
77            }
78        }
79    };
80
81    class SplitFragmentSenderState : public Packet::SenderState
82    {
83      public:
84        SplitFragmentSenderState(PacketPtr _bigPkt, int _index) :
85            bigPkt(_bigPkt), index(_index)
86        {}
87        PacketPtr bigPkt;
88        int index;
89
90        void
91        clearFromParent()
92        {
93            SplitMainSenderState * main_send_state =
94                dynamic_cast<SplitMainSenderState *>(bigPkt->senderState);
95            main_send_state->fragments[index] = NULL;
96        }
97    };
98
99    class FetchTranslation : public BaseTLB::Translation
100    {
101      protected:
102        TimingSimpleCPU *cpu;
103
104      public:
105        FetchTranslation(TimingSimpleCPU *_cpu)
106            : cpu(_cpu)
107        {}
108
109        void
110        markDelayed()
111        {
112            assert(cpu->_status == Running);
113            cpu->_status = ITBWaitResponse;
114        }
115
116        void
117        finish(Fault fault, RequestPtr req, ThreadContext *tc,
118               BaseTLB::Mode mode)
119        {
120            cpu->sendFetch(fault, req, tc);
121        }
122    };
123    FetchTranslation fetchTranslation;
124
125    void sendData(RequestPtr req, uint8_t *data, uint64_t *res, bool read);
126    void sendSplitData(RequestPtr req1, RequestPtr req2, RequestPtr req,
127                       uint8_t *data, bool read);
128
129    void translationFault(Fault fault);
130
131    void buildPacket(PacketPtr &pkt, RequestPtr req, bool read);
132    void buildSplitPacket(PacketPtr &pkt1, PacketPtr &pkt2,
133            RequestPtr req1, RequestPtr req2, RequestPtr req,
134            uint8_t *data, bool read);
135
136    bool handleReadPacket(PacketPtr pkt);
137    // This function always implicitly uses dcache_pkt.
138    bool handleWritePacket();
139
140    /**
141     * A TimingCPUPort overrides the default behaviour of the
142     * recvTiming and recvRetry and implements events for the
143     * scheduling of handling of incoming packets in the following
144     * cycle.
145     */
146    class TimingCPUPort : public CpuPort
147    {
148      public:
149
150        TimingCPUPort(const std::string& _name, TimingSimpleCPU* _cpu)
151            : CpuPort(_name, _cpu), cpu(_cpu), retryEvent(this)
152        { }
153
154      protected:
155
156        TimingSimpleCPU* cpu;
157
158        struct TickEvent : public Event
159        {
160            PacketPtr pkt;
161            TimingSimpleCPU *cpu;
162            CpuPort *port;
163
164            TickEvent(TimingSimpleCPU *_cpu) : pkt(NULL), cpu(_cpu) {}
165            const char *description() const { return "Timing CPU tick"; }
166            void schedule(PacketPtr _pkt, Tick t);
167        };
168
169        EventWrapper<Port, &Port::sendRetry> retryEvent;
170    };
171
172    class IcachePort : public TimingCPUPort
173    {
174      public:
175
176        IcachePort(TimingSimpleCPU *_cpu)
177            : TimingCPUPort(_cpu->name() + "-iport", _cpu),
178              tickEvent(_cpu)
179        { }
180
181      protected:
182
183        virtual bool recvTiming(PacketPtr pkt);
184
185        virtual void recvRetry();
186
187        struct ITickEvent : public TickEvent
188        {
189
190            ITickEvent(TimingSimpleCPU *_cpu)
191                : TickEvent(_cpu) {}
192            void process();
193            const char *description() const { return "Timing CPU icache tick"; }
194        };
195
196        ITickEvent tickEvent;
197
198    };
199
200    class DcachePort : public TimingCPUPort
201    {
202      public:
203
204        DcachePort(TimingSimpleCPU *_cpu)
205            : TimingCPUPort(_cpu->name() + "-dport", _cpu), tickEvent(_cpu)
206        { }
207
208      protected:
209
210        virtual bool recvTiming(PacketPtr pkt);
211
212        virtual void recvRetry();
213
214        struct DTickEvent : public TickEvent
215        {
216            DTickEvent(TimingSimpleCPU *_cpu)
217                : TickEvent(_cpu) {}
218            void process();
219            const char *description() const { return "Timing CPU dcache tick"; }
220        };
221
222        DTickEvent tickEvent;
223
224    };
225
226    IcachePort icachePort;
227    DcachePort dcachePort;
228
229    PacketPtr ifetch_pkt;
230    PacketPtr dcache_pkt;
231
232    Tick previousTick;
233
234  public:
235
236    virtual Port *getPort(const std::string &if_name, int idx = -1);
237
238    virtual void serialize(std::ostream &os);
239    virtual void unserialize(Checkpoint *cp, const std::string &section);
240
241    virtual unsigned int drain(Event *drain_event);
242    virtual void resume();
243
244    void switchOut();
245    void takeOverFrom(BaseCPU *oldCPU);
246
247    virtual void activateContext(ThreadID thread_num, int delay);
248    virtual void suspendContext(ThreadID thread_num);
249
250    Fault readMem(Addr addr, uint8_t *data, unsigned size, unsigned flags);
251
252    Fault writeMem(uint8_t *data, unsigned size,
253                   Addr addr, unsigned flags, uint64_t *res);
254
255    void fetch();
256    void sendFetch(Fault fault, RequestPtr req, ThreadContext *tc);
257    void completeIfetch(PacketPtr );
258    void completeDataAccess(PacketPtr pkt);
259    void advanceInst(Fault fault);
260
261    /**
262     * Print state of address in memory system via PrintReq (for
263     * debugging).
264     */
265    void printAddr(Addr a);
266
267    /**
268     * Finish a DTB translation.
269     * @param state The DTB translation state.
270     */
271    void finishTranslation(WholeTranslationState *state);
272
273  private:
274
275    typedef EventWrapper<TimingSimpleCPU, &TimingSimpleCPU::fetch> FetchEvent;
276    FetchEvent fetchEvent;
277
278    struct IprEvent : Event {
279        Packet *pkt;
280        TimingSimpleCPU *cpu;
281        IprEvent(Packet *_pkt, TimingSimpleCPU *_cpu, Tick t);
282        virtual void process();
283        virtual const char *description() const;
284    };
285
286    void completeDrain();
287};
288
289#endif // __CPU_SIMPLE_TIMING_HH__
290