io_device.hh revision 2592 
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 "mem/packet_impl.hh"
35#include "sim/eventq.hh"
36#include "sim/sim_object.hh"
37
38class Platform;
39class PioDevice;
40class DmaDevice;
41class System;
42
43/**
44 * The PioPort class is a programmed i/o port that all devices that are
45 * sensitive to an address range use. The port takes all the memory
46 * access types and roles them into one read() and write() call that the device
47 * must respond to. The device must also provide the addressRanges() function
48 * with which it returns the address ranges it is interested in. An extra
49 * sendTiming() function is implemented which takes an delay. In this way the
50 * device can immediatly call sendTiming(pkt, time) after processing a request
51 * and the request will be handled by the port even if the port bus the device
52 * connects to is blocked.
53 */
54class PioPort : public Port
55{
56  protected:
57    /** The device that this port serves. */
58    PioDevice *device;
59
60    /** The platform that device/port are in. This is used to select which mode
61     * we are currently operating in. */
62    Platform *platform;
63
64    /** A list of outgoing timing response packets that haven't been serviced
65     * yet. */
66    std::list<Packet*> transmitList;
67
68    /** The current status of the peer(bus) that we are connected to. */
69    Status peerStatus;
70
71    virtual bool recvTiming(Packet &pkt);
72
73    virtual Tick recvAtomic(Packet &pkt);
74
75    virtual void recvFunctional(Packet &pkt) ;
76
77    virtual void recvStatusChange(Status status)
78    { peerStatus = status; }
79
80    virtual void getDeviceAddressRanges(AddrRangeList &resp, AddrRangeList &snoop);
81
82    /**
83     * This class is used to implemented sendTiming() with a delay. When a delay
84     * is requested a new event is created. When the event time expires it
85     * attempts to send the packet. If it cannot, the packet is pushed onto the
86     * transmit list to be sent when recvRetry() is called. */
87    class SendEvent : public Event
88    {
89        PioPort *port;
90        Packet packet;
91
92        SendEvent(PioPort *p, Packet &pkt, Tick t)
93            : Event(&mainEventQueue), packet(pkt)
94        { schedule(curTick + t); }
95
96        virtual void process();
97
98        virtual const char *description()
99        { return "Future scheduled sendTiming event"; }
100
101        friend class PioPort;
102    };
103
104    /** Schedule a sendTiming() event to be called in the future. */
105    void sendTiming(Packet &pkt, Tick time)
106    { new PioPort::SendEvent(this, pkt, time); }
107
108    /** This function pops the last element off the transmit list and sends it.*/
109    virtual Packet *recvRetry();
110
111  public:
112    PioPort(PioDevice *dev, Platform *p);
113
114  friend class PioPort::SendEvent;
115};
116
117
118struct DmaReqState
119{
120    Event *completionEvent;
121    bool final;
122    DmaReqState(Event *ce, bool f)
123        : completionEvent(ce), final(f)
124    {}
125};
126
127class DmaPort : public Port
128{
129  protected:
130    DmaDevice *device;
131    std::list<Packet*> transmitList;
132
133    /** The platform that device/port are in. This is used to select which mode
134     * we are currently operating in. */
135    Platform *platform;
136
137    /** Number of outstanding packets the dma port has. */
138    int pendingCount;
139
140    virtual bool recvTiming(Packet &pkt);
141    virtual Tick recvAtomic(Packet &pkt)
142    { panic("dma port shouldn't be used for pio access."); }
143    virtual void recvFunctional(Packet &pkt)
144    { panic("dma port shouldn't be used for pio access."); }
145
146    virtual void recvStatusChange(Status status)
147    { ; }
148
149    virtual Packet *recvRetry() ;
150
151    virtual void getDeviceAddressRanges(AddrRangeList &resp, AddrRangeList &snoop)
152    { resp.clear(); snoop.clear(); }
153
154    class SendEvent : public Event
155    {
156        DmaPort *port;
157        Packet packet;
158
159        SendEvent(PioPort *p, Packet &pkt, Tick t)
160            : Event(&mainEventQueue), packet(pkt)
161        { schedule(curTick + t); }
162
163        virtual void process();
164
165        virtual const char *description()
166        { return "Future scheduled sendTiming event"; }
167
168        friend class DmaPort;
169    };
170
171    void sendDma(Packet *pkt);
172
173  public:
174    DmaPort(DmaDevice *dev, Platform *p);
175
176    void dmaAction(Command cmd, Addr addr, int size, Event *event,
177            uint8_t *data = NULL);
178
179    bool dmaPending() { return pendingCount > 0; }
180
181  friend class DmaPort::SendEvent;
182
183};
184
185/**
186 * This device is the base class which all devices senstive to an address range
187 * inherit from. There are three pure virtual functions which all devices must
188 * implement addressRanges(), read(), and write(). The magic do choose which
189 * mode we are in, etc is handled by the PioPort so the device doesn't have to
190 * bother.
191 */
192
193class PioDevice : public MemObject
194{
195  protected:
196
197    /** The platform we are in. This is used to decide what type of memory
198     * transaction we should perform. */
199    Platform *platform;
200
201    /** The pioPort that handles the requests for us and provides us requests
202     * that it sees. */
203    PioPort *pioPort;
204
205    virtual void addressRanges(AddrRangeList &range_list) = 0;
206
207    /** As far as the devices are concerned they only accept atomic transactions
208     * which are converted to either a write or a read. */
209    Tick recvAtomic(Packet &pkt)
210    { return pkt.cmd == Read ? this->read(pkt) : this->write(pkt); }
211
212    /** Pure virtual function that the device must implement. Called when a read
213     * command is recieved by the port.
214     * @param pkt Packet describing this request
215     * @return number of ticks it took to complete
216     */
217    virtual Tick read(Packet &pkt) = 0;
218
219    /** Pure virtual function that the device must implement. Called when a
220     * write command is recieved by the port.
221     * @param pkt Packet describing this request
222     * @return number of ticks it took to complete
223     */
224    virtual Tick write(Packet &pkt) = 0;
225
226  public:
227    /** Params struct which is extended through each device based on the
228     * parameters it needs. Since we are re-writing everything, we might as well
229     * start from the bottom this time. */
230
231    struct Params
232    {
233        std::string name;
234        Platform *platform;
235        System *system;
236    };
237
238  protected:
239    Params *_params;
240
241  public:
242    const Params *params() const { return _params; }
243
244    PioDevice(Params *p)
245              : MemObject(p->name),  platform(p->platform), pioPort(NULL),
246                _params(p)
247              {}
248
249    virtual ~PioDevice();
250
251    virtual void init();
252
253    virtual Port *getPort(const std::string &if_name)
254    {
255        if (if_name == "pio") {
256            if (pioPort != NULL)
257                panic("pio port already connected to.");
258            pioPort = new PioPort(this, params()->platform);
259            return pioPort;
260        } else
261            return NULL;
262    }
263    friend class PioPort;
264
265};
266
267class BasicPioDevice : public PioDevice
268{
269  public:
270    struct Params :  public PioDevice::Params
271    {
272        Addr pio_addr;
273        Tick pio_delay;
274    };
275
276  protected:
277    /** Address that the device listens to. */
278    Addr pioAddr;
279
280    /** Size that the device's address range. */
281    Addr pioSize;
282
283    /** Delay that the device experinces on an access. */
284    Tick pioDelay;
285
286  public:
287    BasicPioDevice(Params *p)
288        : PioDevice(p), pioAddr(p->pio_addr), pioSize(0), pioDelay(p->pio_delay)
289    {}
290
291    /** return the address ranges that this device responds to.
292     * @params range_list range list to populate with ranges
293     */
294    void addressRanges(AddrRangeList &range_list);
295
296};
297
298class DmaDevice : public PioDevice
299{
300  protected:
301    DmaPort *dmaPort;
302
303  public:
304    DmaDevice(Params *p);
305    virtual ~DmaDevice();
306
307    void dmaWrite(Addr addr, int size, Event *event, uint8_t *data)
308    { dmaPort->dmaAction(Write, addr, size, event, data) ; }
309
310    void dmaRead(Addr addr, int size, Event *event, uint8_t *data = NULL)
311    { dmaPort->dmaAction(Read, addr, size, event, data); }
312
313    bool dmaPending() { return dmaPort->dmaPending(); }
314
315    virtual Port *getPort(const std::string &if_name)
316    {
317        if (if_name == "pio") {
318            if (pioPort != NULL)
319                panic("pio port already connected to.");
320            pioPort = new PioPort(this, params()->platform);
321            return pioPort;
322        } else if (if_name == "dma") {
323            if (dmaPort != NULL)
324                panic("dma port already connected to.");
325            dmaPort = new DmaPort(this, params()->platform);
326            return dmaPort;
327        } else
328            return NULL;
329    }
330
331    friend class DmaPort;
332};
333
334
335#endif // __DEV_IO_DEVICE_HH__
336