summaryrefslogtreecommitdiff
path: root/dev/io_device.hh
blob: ba16372cc181ded014becbc594c1951bdad2eab6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
/*
 * Copyright (c) 2004-2005 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.
 */

#ifndef __DEV_IO_DEVICE_HH__
#define __DEV_IO_DEVICE_HH__

#include "base/chunk_generator.hh"
#include "mem/port.hh"
#include "sim/eventq.hh"
#include "sim/sim_object.hh"

class Platform;
class PioDevice;
class DmaDevice;

/**
 * The PioPort class is a programmed i/o port that all devices that are
 * sensitive to an address range use. The port takes all the memory
 * access types and roles them into one read() and write() call that the device
 * must respond to. The device must also provide the addressRanges() function
 * with which it returns the address ranges it is interested in. An extra
 * sendTiming() function is implemented which takes an delay. In this way the
 * device can immediatly call sendTiming(pkt, time) after processing a request
 * and the request will be handled by the port even if the port bus the device
 * connects to is blocked.
 */
class PioPort : public Port
{
  protected:
    /** The device that this port serves. */
    PioDevice *device;

    /** The platform that device/port are in. This is used to select which mode
     * we are currently operating in. */
    Platform *platform;

    /** A list of outgoing timing response packets that haven't been serviced
     * yet. */
    std::list<Packet*> transmitList;

    /** The current status of the peer(bus) that we are connected to. */
    Status peerStatus;

    virtual bool recvTiming(Packet &pkt);

    virtual Tick recvAtomic(Packet &pkt);

    virtual void recvFunctional(Packet &pkt) ;

    virtual void recvStatusChange(Status status)
    { peerStatus = status; }

    virtual void getDeviceAddressRanges(AddrRangeList &range_list, bool &owner);

    /**
     * This class is used to implemented sendTiming() with a delay. When a delay
     * is requested a new event is created. When the event time expires it
     * attempts to send the packet. If it cannot, the packet is pushed onto the
     * transmit list to be sent when recvRetry() is called. */
    class SendEvent : public Event
    {
        PioPort *port;
        Packet packet;

        SendEvent(PioPort *p, Packet &pkt, Tick t)
            : Event(&mainEventQueue), packet(pkt)
        { schedule(curTick + t); }

        virtual void process();

        virtual const char *description()
        { return "Future scheduled sendTiming event"; }

        friend class PioPort;
    };

    /** Schedule a sendTiming() event to be called in the future. */
    void sendTiming(Packet &pkt, Tick time)
    { new PioPort::SendEvent(this, pkt, time); }

    /** This function pops the last element off the transmit list and sends it.*/
    virtual Packet *recvRetry();

  public:
    PioPort(PioDevice *dev, Platform *p);

  friend class PioPort::SendEvent;
};

class DmaPort : public Port
{
  protected:
    PioDevice *device;
    std::list<Packet*> transmitList;
    Event *completionEvent;


    virtual bool recvTiming(Packet &pkt);
    virtual Tick recvAtomic(Packet &pkt)
    { panic("dma port shouldn't be used for pio access."); }
    virtual void recvFunctional(Packet &pkt)
    { panic("dma port shouldn't be used for pio access."); }

    virtual void recvStatusChange(Status status)
    { ; }

    virtual Packet *recvRetry() ;

    virtual void getDeviceAddressRanges(AddrRangeList &range_list, bool &owner)
    { range_list.clear(); owner = true; }

    class SendEvent : public Event
    {
        DmaPort *port;
        Packet packet;

        SendEvent(PioPort *p, Packet &pkt, Tick t)
            : Event(&mainEventQueue), packet(pkt)
        { schedule(curTick + t); }

        virtual void process();

        virtual const char *description()
        { return "Future scheduled sendTiming event"; }

        friend class DmaPort;
    };

    void dmaAction(Command cmd, DmaPort port, Addr addr, int size,
              Event *event, uint8_t *data = NULL);

    void sendDma(Packet &pkt);

  public:
    DmaPort(DmaDevice *dev);

  friend class DmaPort::SendEvent;

};

/**
 * This device is the base class which all devices senstive to an address range
 * inherit from. There are three pure virtual functions which all devices must
 * implement addressRanges(), read(), and write(). The magic do choose which
 * mode we are in, etc is handled by the PioPort so the device doesn't have to
 * bother.
 */

class PioDevice : public SimObject
{
  protected:

    /** The platform we are in. This is used to decide what type of memory
     * transaction we should perform. */
    Platform *platform;

    /** The pioPort that handles the requests for us and provides us requests
     * that it sees. */
    PioPort *pioPort;

    virtual void addressRanges(AddrRangeList &range_list, bool &owner) = 0;

    /** As far as the devices are concerned they only accept atomic transactions
     * which are converted to either a write or a read. */
    Tick recvAtomic(Packet &pkt)
    { return pkt.cmd == Read ? this->read(pkt) : this->write(pkt); }

    /** Pure virtual function that the device must implement. Called when a read
     * command is recieved by the port. */
    virtual bool read(Packet &pkt) = 0;

    /** Pure virtual function that the device must implement. Called when a
     * write command is recieved by the port. */
    virtual bool write(Packet &pkt) = 0;

  public:
    PioDevice(const std::string &name, Platform *p);

    virtual ~PioDevice();

    virtual Port *getPort(const std::string &if_name)
    {
        if (if_name == "pio")
            return pioPort;
        else
            return NULL;
    }
    friend class PioPort;

};

class DmaDevice : public PioDevice
{
  protected:
    DmaPort *dmaPort;

  public:
    DmaDevice(const std::string &name, Platform *p);
    virtual ~DmaDevice();

    virtual Port *getPort(const std::string &if_name)
    {
        if (if_name == "pio")
            return pioPort;
        else if (if_name == "dma")
            return dmaPort;
        else
            return NULL;
    }

    friend class DmaPort;
};


#endif // __DEV_IO_DEVICE_HH__