io_device.hh revision 2569 
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/mem_object.hh"
34#include "sim/eventq.hh"
35#include "sim/sim_object.hh"
36
37class Platform;
38class PioDevice;
39class DmaDevice;
40class System;
41
42/**
43 * The PioPort class is a programmed i/o port that all devices that are
44 * sensitive to an address range use. The port takes all the memory
45 * access types and roles them into one read() and write() call that the device
46 * must respond to. The device must also provide the addressRanges() function
47 * with which it returns the address ranges it is interested in. An extra
48 * sendTiming() function is implemented which takes an delay. In this way the
49 * device can immediatly call sendTiming(pkt, time) after processing a request
50 * and the request will be handled by the port even if the port bus the device
51 * connects to is blocked.
52 */
53class PioPort : public Port
54{
55  protected:
56    /** The device that this port serves. */
57    PioDevice *device;
58
59    /** The platform that device/port are in. This is used to select which mode
60     * we are currently operating in. */
61    Platform *platform;
62
63    /** A list of outgoing timing response packets that haven't been serviced
64     * yet. */
65    std::list<Packet*> transmitList;
66
67    /** The current status of the peer(bus) that we are connected to. */
68    Status peerStatus;
69
70    virtual bool recvTiming(Packet &pkt);
71
72    virtual Tick recvAtomic(Packet &pkt);
73
74    virtual void recvFunctional(Packet &pkt) ;
75
76    virtual void recvStatusChange(Status status)
77    { peerStatus = status; }
78
79    virtual void getDeviceAddressRanges(AddrRangeList &resp, AddrRangeList &snoop);
80
81    /**
82     * This class is used to implemented sendTiming() with a delay. When a delay
83     * is requested a new event is created. When the event time expires it
84     * attempts to send the packet. If it cannot, the packet is pushed onto the
85     * transmit list to be sent when recvRetry() is called. */
86    class SendEvent : public Event
87    {
88        PioPort *port;
89        Packet packet;
90
91        SendEvent(PioPort *p, Packet &pkt, Tick t)
92            : Event(&mainEventQueue), packet(pkt)
93        { schedule(curTick + t); }
94
95        virtual void process();
96
97        virtual const char *description()
98        { return "Future scheduled sendTiming event"; }
99
100        friend class PioPort;
101    };
102
103    /** Schedule a sendTiming() event to be called in the future. */
104    void sendTiming(Packet &pkt, Tick time)
105    { new PioPort::SendEvent(this, pkt, time); }
106
107    /** This function pops the last element off the transmit list and sends it.*/
108    virtual Packet *recvRetry();
109
110  public:
111    PioPort(PioDevice *dev, Platform *p);
112
113  friend class PioPort::SendEvent;
114};
115
116
117struct DmaReqState
118{
119    Event *completionEvent;
120    bool final;
121    DmaReqState(Event *ce, bool f)
122        : completionEvent(ce), final(f)
123    {}
124};
125
126class DmaPort : public Port
127{
128  protected:
129    DmaDevice *device;
130    std::list<Packet*> transmitList;
131
132    /** The platform that device/port are in. This is used to select which mode
133     * we are currently operating in. */
134    Platform *platform;
135
136    /** Number of outstanding packets the dma port has. */
137    int pendingCount;
138
139    virtual bool recvTiming(Packet &pkt);
140    virtual Tick recvAtomic(Packet &pkt)
141    { panic("dma port shouldn't be used for pio access."); }
142    virtual void recvFunctional(Packet &pkt)
143    { panic("dma port shouldn't be used for pio access."); }
144
145    virtual void recvStatusChange(Status status)
146    { ; }
147
148    virtual Packet *recvRetry() ;
149
150    virtual void getDeviceAddressRanges(AddrRangeList &resp, AddrRangeList &snoop)
151    { resp.clear(); snoop.clear(); }
152
153    class SendEvent : public Event
154    {
155        DmaPort *port;
156        Packet packet;
157
158        SendEvent(PioPort *p, Packet &pkt, Tick t)
159            : Event(&mainEventQueue), packet(pkt)
160        { schedule(curTick + t); }
161
162        virtual void process();
163
164        virtual const char *description()
165        { return "Future scheduled sendTiming event"; }
166
167        friend class DmaPort;
168    };
169
170    void sendDma(Packet *pkt);
171
172  public:
173    DmaPort(DmaDevice *dev, Platform *p);
174
175    void dmaAction(Command cmd, Addr addr, int size, Event *event,
176            uint8_t *data = NULL);
177
178    bool dmaPending() { return pendingCount > 0; }
179
180  friend class DmaPort::SendEvent;
181
182};
183
184/**
185 * This device is the base class which all devices senstive to an address range
186 * inherit from. There are three pure virtual functions which all devices must
187 * implement addressRanges(), read(), and write(). The magic do choose which
188 * mode we are in, etc is handled by the PioPort so the device doesn't have to
189 * bother.
190 */
191
192class PioDevice : public MemObject
193{
194  protected:
195
196    /** The platform we are in. This is used to decide what type of memory
197     * transaction we should perform. */
198    Platform *platform;
199
200    /** The pioPort that handles the requests for us and provides us requests
201     * that it sees. */
202    PioPort *pioPort;
203
204    virtual void addressRanges(AddrRangeList &range_list) = 0;
205
206    /** As far as the devices are concerned they only accept atomic transactions
207     * which are converted to either a write or a read. */
208    Tick recvAtomic(Packet &pkt)
209    { return pkt.cmd == Read ? this->read(pkt) : this->write(pkt); }
210
211    /** Pure virtual function that the device must implement. Called when a read
212     * command is recieved by the port.
213     * @param pkt Packet describing this request
214     * @return number of ticks it took to complete
215     */
216    virtual Tick read(Packet &pkt) = 0;
217
218    /** Pure virtual function that the device must implement. Called when a
219     * write command is recieved by the port.
220     * @param pkt Packet describing this request
221     * @return number of ticks it took to complete
222     */
223    virtual Tick write(Packet &pkt) = 0;
224
225  public:
226    /** Params struct which is extended through each device based on the
227     * parameters it needs. Since we are re-writing everything, we might as well
228     * start from the bottom this time. */
229
230    struct Params
231    {
232        std::string name;
233        Platform *platform;
234        System *system;
235    };
236
237  protected:
238    Params *_params;
239
240  public:
241    const Params *params() const { return _params; }
242
243    PioDevice(Params *p)
244              : MemObject(p->name),  platform(p->platform), pioPort(NULL),
245                _params(p)
246              {}
247
248    virtual ~PioDevice();
249
250    virtual void init();
251
252    virtual Port *getPort(const std::string &if_name)
253    {
254        if (if_name == "pio") {
255            if (pioPort != NULL)
256                panic("pio port already connected to.");
257            pioPort = new PioPort(this, params()->platform);
258            return pioPort;
259        } else
260            return NULL;
261    }
262    friend class PioPort;
263
264};
265
266class BasicPioDevice : public PioDevice
267{
268  public:
269    struct Params :  public PioDevice::Params
270    {
271        Addr pio_addr;
272        Tick pio_delay;
273    };
274
275  protected:
276    /** Address that the device listens to. */
277    Addr pioAddr;
278
279    /** Size that the device's address range. */
280    Addr pioSize;
281
282    /** Delay that the device experinces on an access. */
283    Tick pioDelay;
284
285  public:
286    BasicPioDevice(Params *p)
287        : PioDevice(p), pioAddr(p->pio_addr), pioSize(0), pioDelay(p->pio_delay)
288    {}
289
290    /** return the address ranges that this device responds to.
291     * @params range_list range list to populate with ranges
292     */
293    void addressRanges(AddrRangeList &range_list);
294
295};
296
297class DmaDevice : public PioDevice
298{
299  protected:
300    DmaPort *dmaPort;
301
302  public:
303    DmaDevice(Params *p);
304    virtual ~DmaDevice();
305
306    void dmaWrite(Addr addr, int size, Event *event, uint8_t *data)
307    { dmaPort->dmaAction(Write, addr, size, event, data) ; }
308
309    void dmaRead(Addr addr, int size, Event *event, uint8_t *data = NULL)
310    { dmaPort->dmaAction(Read, addr, size, event, data); }
311
312    bool dmaPending() { return dmaPort->dmaPending(); }
313
314    virtual Port *getPort(const std::string &if_name)
315    {
316        if (if_name == "pio") {
317            if (pioPort != NULL)
318                panic("pio port already connected to.");
319            pioPort = new PioPort(this, params()->platform);
320            return pioPort;
321        } else if (if_name == "dma") {
322            if (dmaPort != NULL)
323                panic("dma port already connected to.");
324            dmaPort = new DmaPort(this, params()->platform);
325            return dmaPort;
326        } else
327            return NULL;
328    }
329
330    friend class DmaPort;
331};
332
333
334#endif // __DEV_IO_DEVICE_HH__
335