io_device.hh revision 2846 
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 * Authors: Ali Saidi
29 *          Nathan Binkert
30 */
31
32#ifndef __DEV_IO_DEVICE_HH__
33#define __DEV_IO_DEVICE_HH__
34
35#include "base/chunk_generator.hh"
36#include "mem/mem_object.hh"
37#include "mem/packet_impl.hh"
38#include "sim/eventq.hh"
39#include "sim/sim_object.hh"
40
41class Platform;
42class PioDevice;
43class DmaDevice;
44class System;
45
46/**
47 * The PioPort class is a programmed i/o port that all devices that are
48 * sensitive to an address range use. The port takes all the memory
49 * access types and roles them into one read() and write() call that the device
50 * must respond to. The device must also provide the addressRanges() function
51 * with which it returns the address ranges it is interested in. An extra
52 * sendTiming() function is implemented which takes an delay. In this way the
53 * device can immediatly call sendTiming(pkt, time) after processing a request
54 * and the request will be handled by the port even if the port bus the device
55 * connects to is blocked.
56 */
57class PioPort : public Port
58{
59  protected:
60    /** The device that this port serves. */
61    PioDevice *device;
62
63    /** The platform that device/port are in. This is used to select which mode
64     * we are currently operating in. */
65    Platform *platform;
66
67    /** A list of outgoing timing response packets that haven't been serviced
68     * yet. */
69    std::list<Packet*> transmitList;
70
71    /** The current status of the peer(bus) that we are connected to. */
72    Status peerStatus;
73
74    virtual bool recvTiming(Packet *pkt);
75
76    virtual Tick recvAtomic(Packet *pkt);
77
78    virtual void recvFunctional(Packet *pkt) ;
79
80    virtual void recvStatusChange(Status status)
81    { peerStatus = status; }
82
83    virtual void getDeviceAddressRanges(AddrRangeList &resp, AddrRangeList &snoop);
84
85    void resendNacked(Packet *pkt);
86
87    /**
88     * This class is used to implemented sendTiming() with a delay. When a delay
89     * is requested a new event is created. When the event time expires it
90     * attempts to send the packet. If it cannot, the packet is pushed onto the
91     * transmit list to be sent when recvRetry() is called. */
92    class SendEvent : public Event
93    {
94        PioPort *port;
95        Packet *packet;
96
97        SendEvent(PioPort *p, Packet *pkt, Tick t)
98            : Event(&mainEventQueue), port(p), packet(pkt)
99        { schedule(curTick + t); }
100
101        virtual void process();
102
103        virtual const char *description()
104        { return "Future scheduled sendTiming event"; }
105
106        friend class PioPort;
107    };
108
109    /** Schedule a sendTiming() event to be called in the future. */
110    void sendTiming(Packet *pkt, Tick time)
111    { new PioPort::SendEvent(this, pkt, time); }
112
113    /** This function is notification that the device should attempt to send a
114     * packet again. */
115    virtual void recvRetry();
116
117  public:
118    PioPort(PioDevice *dev, Platform *p, std::string pname = "-pioport");
119
120  friend class PioPort::SendEvent;
121};
122
123
124class DmaPort : public Port
125{
126  protected:
127    struct DmaReqState : public Packet::SenderState
128    {
129        /** Event to call on the device when this transaction (all packets)
130         * complete. */
131        Event *completionEvent;
132
133        /** Where we came from for some sanity checking. */
134        Port *outPort;
135
136        /** Total number of bytes that this transaction involves. */
137        Addr totBytes;
138
139        /** Number of bytes that have been acked for this transaction. */
140        Addr numBytes;
141
142        DmaReqState(Event *ce, Port *p, Addr tb)
143            : completionEvent(ce), outPort(p), totBytes(tb), numBytes(0)
144        {}
145    };
146
147    DmaDevice *device;
148    std::list<Packet*> transmitList;
149
150    /** The platform that device/port are in. This is used to select which mode
151     * we are currently operating in. */
152    Platform *platform;
153
154    /** Number of outstanding packets the dma port has. */
155    int pendingCount;
156
157    virtual bool recvTiming(Packet *pkt);
158    virtual Tick recvAtomic(Packet *pkt)
159    { panic("dma port shouldn't be used for pio access."); }
160    virtual void recvFunctional(Packet *pkt)
161    { panic("dma port shouldn't be used for pio access."); }
162
163    virtual void recvStatusChange(Status status)
164    { ; }
165
166    virtual void recvRetry() ;
167
168    virtual void getDeviceAddressRanges(AddrRangeList &resp, AddrRangeList &snoop)
169    { resp.clear(); snoop.clear(); }
170
171    void sendDma(Packet *pkt, bool front = false);
172
173  public:
174    DmaPort(DmaDevice *dev, Platform *p);
175
176    void dmaAction(Packet::Command cmd, Addr addr, int size, Event *event,
177                   uint8_t *data = NULL);
178
179    bool dmaPending() { return pendingCount > 0; }
180
181};
182
183/**
184 * This device is the base class which all devices senstive to an address range
185 * inherit from. There are three pure virtual functions which all devices must
186 * implement addressRanges(), read(), and write(). The magic do choose which
187 * mode we are in, etc is handled by the PioPort so the device doesn't have to
188 * bother.
189 */
190
191class PioDevice : public MemObject
192{
193  protected:
194
195    /** The platform we are in. This is used to decide what type of memory
196     * transaction we should perform. */
197    Platform *platform;
198
199    /** The pioPort that handles the requests for us and provides us requests
200     * that it sees. */
201    PioPort *pioPort;
202
203    virtual void addressRanges(AddrRangeList &range_list) = 0;
204
205    /** As far as the devices are concerned they only accept atomic transactions
206     * which are converted to either a write or a read. */
207    Tick recvAtomic(Packet *pkt)
208    { return pkt->isRead() ? this->read(pkt) : this->write(pkt); }
209
210    /** Pure virtual function that the device must implement. Called when a read
211     * command is recieved by the port.
212     * @param pkt Packet describing this request
213     * @return number of ticks it took to complete
214     */
215    virtual Tick read(Packet *pkt) = 0;
216
217    /** Pure virtual function that the device must implement. Called when a
218     * write command is recieved by the port.
219     * @param pkt Packet describing this request
220     * @return number of ticks it took to complete
221     */
222    virtual Tick write(Packet *pkt) = 0;
223
224  public:
225    /** Params struct which is extended through each device based on the
226     * parameters it needs. Since we are re-writing everything, we might as well
227     * start from the bottom this time. */
228
229    struct Params
230    {
231        std::string name;
232        Platform *platform;
233        System *system;
234    };
235
236  protected:
237    Params *_params;
238
239  public:
240    const Params *params() const { return _params; }
241
242    PioDevice(Params *p)
243              : MemObject(p->name),  platform(p->platform), pioPort(NULL),
244                _params(p)
245              {}
246
247    virtual ~PioDevice();
248
249    virtual void init();
250
251    virtual Port *getPort(const std::string &if_name, int idx = -1)
252    {
253        if (if_name == "pio") {
254            if (pioPort != NULL)
255                panic("pio port already connected to.");
256            pioPort = new PioPort(this, params()->platform);
257            return pioPort;
258        } else
259            return NULL;
260    }
261    friend class PioPort;
262
263};
264
265class BasicPioDevice : public PioDevice
266{
267  public:
268    struct Params :  public PioDevice::Params
269    {
270        Addr pio_addr;
271        Tick pio_delay;
272    };
273
274  protected:
275    /** Address that the device listens to. */
276    Addr pioAddr;
277
278    /** Size that the device's address range. */
279    Addr pioSize;
280
281    /** Delay that the device experinces on an access. */
282    Tick pioDelay;
283
284  public:
285    BasicPioDevice(Params *p)
286        : PioDevice(p), pioAddr(p->pio_addr), pioSize(0), pioDelay(p->pio_delay)
287    {}
288
289    /** return the address ranges that this device responds to.
290     * @params range_list range list to populate with ranges
291     */
292    void addressRanges(AddrRangeList &range_list);
293
294};
295
296class DmaDevice : public PioDevice
297{
298  protected:
299    DmaPort *dmaPort;
300
301  public:
302    DmaDevice(Params *p);
303    virtual ~DmaDevice();
304
305    void dmaWrite(Addr addr, int size, Event *event, uint8_t *data)
306    { dmaPort->dmaAction(Packet::WriteReq, addr, size, event, data) ; }
307
308    void dmaRead(Addr addr, int size, Event *event, uint8_t *data = NULL)
309    { dmaPort->dmaAction(Packet::ReadReq, addr, size, event, data); }
310
311    bool dmaPending() { return dmaPort->dmaPending(); }
312
313    virtual Port *getPort(const std::string &if_name, int idx = -1)
314    {
315        if (if_name == "pio") {
316            if (pioPort != NULL)
317                panic("pio port already connected to.");
318            pioPort = new PioPort(this, params()->platform);
319            return pioPort;
320        } else if (if_name == "dma") {
321            if (dmaPort != NULL)
322                panic("dma port already connected to.");
323            dmaPort = new DmaPort(this, params()->platform);
324            return dmaPort;
325        } else
326            return NULL;
327    }
328
329    friend class DmaPort;
330};
331
332
333#endif // __DEV_IO_DEVICE_HH__
334