io_device.hh revision 2521 
1/*
2 * Copyright (c) 2004-2005 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
29#ifndef __DEV_IO_DEVICE_HH__
30#define __DEV_IO_DEVICE_HH__
31
32#include "base/chunk_generator.hh"
33#include "mem/port.hh"
34#include "sim/eventq.hh"
35#include "sim/sim_object.hh"
36
37class Platform;
38class PioDevice;
39class DmaDevice;
40
41/**
42 * The PioPort class is a programmed i/o port that all devices that are
43 * sensitive to an address range use. The port takes all the memory
44 * access types and roles them into one read() and write() call that the device
45 * must respond to. The device must also provide the addressRanges() function
46 * with which it returns the address ranges it is interested in. An extra
47 * sendTiming() function is implemented which takes an delay. In this way the
48 * device can immediatly call sendTiming(pkt, time) after processing a request
49 * and the request will be handled by the port even if the port bus the device
50 * connects to is blocked.
51 */
52class PioPort : public Port
53{
54  protected:
55    /** The device that this port serves. */
56    PioDevice *device;
57
58    /** The platform that device/port are in. This is used to select which mode
59     * we are currently operating in. */
60    Platform *platform;
61
62    /** A list of outgoing timing response packets that haven't been serviced
63     * yet. */
64    std::list<Packet*> transmitList;
65
66    /** The current status of the peer(bus) that we are connected to. */
67    Status peerStatus;
68
69    virtual bool recvTiming(Packet &pkt);
70
71    virtual Tick recvAtomic(Packet &pkt);
72
73    virtual void recvFunctional(Packet &pkt) ;
74
75    virtual void recvStatusChange(Status status)
76    { peerStatus = status; }
77
78    virtual void getDeviceAddressRanges(AddrRangeList &resp, AddrRangeList &snoop);
79
80    /**
81     * This class is used to implemented sendTiming() with a delay. When a delay
82     * is requested a new event is created. When the event time expires it
83     * attempts to send the packet. If it cannot, the packet is pushed onto the
84     * transmit list to be sent when recvRetry() is called. */
85    class SendEvent : public Event
86    {
87        PioPort *port;
88        Packet packet;
89
90        SendEvent(PioPort *p, Packet &pkt, Tick t)
91            : Event(&mainEventQueue), packet(pkt)
92        { schedule(curTick + t); }
93
94        virtual void process();
95
96        virtual const char *description()
97        { return "Future scheduled sendTiming event"; }
98
99        friend class PioPort;
100    };
101
102    /** Schedule a sendTiming() event to be called in the future. */
103    void sendTiming(Packet &pkt, Tick time)
104    { new PioPort::SendEvent(this, pkt, time); }
105
106    /** This function pops the last element off the transmit list and sends it.*/
107    virtual Packet *recvRetry();
108
109  public:
110    PioPort(PioDevice *dev, Platform *p);
111
112  friend class PioPort::SendEvent;
113};
114
115class DmaPort : public Port
116{
117  protected:
118    PioDevice *device;
119    std::list<Packet*> transmitList;
120    Event *completionEvent;
121
122
123    virtual bool recvTiming(Packet &pkt);
124    virtual Tick recvAtomic(Packet &pkt)
125    { panic("dma port shouldn't be used for pio access."); }
126    virtual void recvFunctional(Packet &pkt)
127    { panic("dma port shouldn't be used for pio access."); }
128
129    virtual void recvStatusChange(Status status)
130    { ; }
131
132    virtual Packet *recvRetry() ;
133
134    virtual void getDeviceAddressRanges(AddrRangeList &resp, AddrRangeList &snoop)
135    { resp.clear(); snoop.clear(); }
136
137    class SendEvent : public Event
138    {
139        DmaPort *port;
140        Packet packet;
141
142        SendEvent(PioPort *p, Packet &pkt, Tick t)
143            : Event(&mainEventQueue), packet(pkt)
144        { schedule(curTick + t); }
145
146        virtual void process();
147
148        virtual const char *description()
149        { return "Future scheduled sendTiming event"; }
150
151        friend class DmaPort;
152    };
153
154    void dmaAction(Command cmd, DmaPort port, Addr addr, int size,
155              Event *event, uint8_t *data = NULL);
156
157    void sendDma(Packet &pkt);
158
159  public:
160    DmaPort(DmaDevice *dev);
161
162  friend class DmaPort::SendEvent;
163
164};
165
166/**
167 * This device is the base class which all devices senstive to an address range
168 * inherit from. There are three pure virtual functions which all devices must
169 * implement addressRanges(), read(), and write(). The magic do choose which
170 * mode we are in, etc is handled by the PioPort so the device doesn't have to
171 * bother.
172 */
173
174class PioDevice : public SimObject
175{
176  protected:
177
178    /** The platform we are in. This is used to decide what type of memory
179     * transaction we should perform. */
180    Platform *platform;
181
182    /** The pioPort that handles the requests for us and provides us requests
183     * that it sees. */
184    PioPort *pioPort;
185
186    virtual void addressRanges(AddrRangeList &range_list) = 0;
187
188    /** As far as the devices are concerned they only accept atomic transactions
189     * which are converted to either a write or a read. */
190    Tick recvAtomic(Packet &pkt)
191    { return pkt.cmd == Read ? this->read(pkt) : this->write(pkt); }
192
193    /** Pure virtual function that the device must implement. Called when a read
194     * command is recieved by the port. */
195    virtual Tick read(Packet &pkt) = 0;
196
197    /** Pure virtual function that the device must implement. Called when a
198     * write command is recieved by the port. */
199    virtual Tick write(Packet &pkt) = 0;
200
201  public:
202    /** Params struct which is extended through each device based on the
203     * parameters it needs. Since we are re-writing everything, we might as well
204     * start from the bottom this time. */
205
206    struct Params
207    {
208        std::string name;
209        Platform *platform;
210    };
211
212  protected:
213    Params *_params;
214
215  public:
216    const Params *params() const { return _params; }
217
218    PioDevice(Params *p)
219              : SimObject(params()->name), platform(p->platform), _params(p)
220              {}
221
222    virtual ~PioDevice();
223
224    virtual Port *getPort(const std::string &if_name)
225    {
226        if (if_name == "pio") {
227            if (pioPort != NULL)
228                panic("pio port already connected to.");
229            pioPort = new PioPort(this, params()->platform);
230            return pioPort;
231        } else
232            return NULL;
233    }
234    friend class PioPort;
235
236};
237
238class BasicPioDevice : public PioDevice
239{
240  public:
241    struct Params :  public PioDevice::Params
242    {
243        Addr pio_addr;
244        Tick pio_delay;
245    };
246
247  protected:
248    /** Address that the device listens to. */
249    Addr pioAddr;
250
251    /** Size that the device's address range. */
252    Addr pioSize;
253
254    /** Delay that the device experinces on an access. */
255    Tick pioDelay;
256
257  public:
258    BasicPioDevice(Params *p)
259        : PioDevice(p), pioAddr(p->pio_addr), pioSize(0), pioDelay(p->pio_delay)
260    {}
261
262};
263
264class DmaDevice : public PioDevice
265{
266  protected:
267    DmaPort *dmaPort;
268
269  public:
270    DmaDevice(Params *p);
271    virtual ~DmaDevice();
272
273    virtual Port *getPort(const std::string &if_name)
274    {
275        if (if_name == "pio")
276            return pioPort;
277        else if (if_name == "dma")
278            return dmaPort;
279        else
280            return NULL;
281    }
282
283    friend class DmaPort;
284};
285
286
287#endif // __DEV_IO_DEVICE_HH__
288