io_device.hh revision 2784:6cff1a1c2935 
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    /**
86     * This class is used to implemented sendTiming() with a delay. When a delay
87     * is requested a new event is created. When the event time expires it
88     * attempts to send the packet. If it cannot, the packet is pushed onto the
89     * transmit list to be sent when recvRetry() is called. */
90    class SendEvent : public Event
91    {
92        PioPort *port;
93        Packet *packet;
94
95        SendEvent(PioPort *p, Packet *pkt, Tick t)
96            : Event(&mainEventQueue), port(p), packet(pkt)
97        { schedule(curTick + t); }
98
99        virtual void process();
100
101        virtual const char *description()
102        { return "Future scheduled sendTiming event"; }
103
104        friend class PioPort;
105    };
106
107    /** Schedule a sendTiming() event to be called in the future. */
108    void sendTiming(Packet *pkt, Tick time)
109    { new PioPort::SendEvent(this, pkt, time); }
110
111    /** This function is notification that the device should attempt to send a
112     * packet again. */
113    virtual void recvRetry();
114
115  public:
116    PioPort(PioDevice *dev, Platform *p);
117
118  friend class PioPort::SendEvent;
119};
120
121
122class DmaPort : public Port
123{
124  protected:
125    struct DmaReqState : public Packet::SenderState
126    {
127        /** Event to call on the device when this transaction (all packets)
128         * complete. */
129        Event *completionEvent;
130
131        /** Where we came from for some sanity checking. */
132        Port *outPort;
133
134        /** Total number of bytes that this transaction involves. */
135        Addr totBytes;
136
137        /** Number of bytes that have been acked for this transaction. */
138        Addr numBytes;
139
140        DmaReqState(Event *ce, Port *p, Addr tb)
141            : completionEvent(ce), outPort(p), totBytes(tb), numBytes(0)
142        {}
143    };
144
145    DmaDevice *device;
146    std::list<Packet*> transmitList;
147
148    /** The platform that device/port are in. This is used to select which mode
149     * we are currently operating in. */
150    Platform *platform;
151
152    /** Number of outstanding packets the dma port has. */
153    int pendingCount;
154
155    virtual bool recvTiming(Packet *pkt);
156    virtual Tick recvAtomic(Packet *pkt)
157    { panic("dma port shouldn't be used for pio access."); }
158    virtual void recvFunctional(Packet *pkt)
159    { panic("dma port shouldn't be used for pio access."); }
160
161    virtual void recvStatusChange(Status status)
162    { ; }
163
164    virtual void recvRetry() ;
165
166    virtual void getDeviceAddressRanges(AddrRangeList &resp, AddrRangeList &snoop)
167    { resp.clear(); snoop.clear(); }
168
169    void sendDma(Packet *pkt, bool front = false);
170
171  public:
172    DmaPort(DmaDevice *dev, Platform *p);
173
174    void dmaAction(Packet::Command cmd, Addr addr, int size, Event *event,
175                   uint8_t *data = NULL);
176
177    bool dmaPending() { return pendingCount > 0; }
178
179};
180
181/**
182 * This device is the base class which all devices senstive to an address range
183 * inherit from. There are three pure virtual functions which all devices must
184 * implement addressRanges(), read(), and write(). The magic do choose which
185 * mode we are in, etc is handled by the PioPort so the device doesn't have to
186 * bother.
187 */
188
189class PioDevice : public MemObject
190{
191  protected:
192
193    /** The platform we are in. This is used to decide what type of memory
194     * transaction we should perform. */
195    Platform *platform;
196
197    /** The pioPort that handles the requests for us and provides us requests
198     * that it sees. */
199    PioPort *pioPort;
200
201    virtual void addressRanges(AddrRangeList &range_list) = 0;
202
203    /** As far as the devices are concerned they only accept atomic transactions
204     * which are converted to either a write or a read. */
205    Tick recvAtomic(Packet *pkt)
206    { return pkt->isRead() ? this->read(pkt) : this->write(pkt); }
207
208    /** Pure virtual function that the device must implement. Called when a read
209     * command is recieved by the port.
210     * @param pkt Packet describing this request
211     * @return number of ticks it took to complete
212     */
213    virtual Tick read(Packet *pkt) = 0;
214
215    /** Pure virtual function that the device must implement. Called when a
216     * write command is recieved by the port.
217     * @param pkt Packet describing this request
218     * @return number of ticks it took to complete
219     */
220    virtual Tick write(Packet *pkt) = 0;
221
222  public:
223    /** Params struct which is extended through each device based on the
224     * parameters it needs. Since we are re-writing everything, we might as well
225     * start from the bottom this time. */
226
227    struct Params
228    {
229        std::string name;
230        Platform *platform;
231        System *system;
232    };
233
234  protected:
235    Params *_params;
236
237  public:
238    const Params *params() const { return _params; }
239
240    PioDevice(Params *p)
241              : MemObject(p->name),  platform(p->platform), pioPort(NULL),
242                _params(p)
243              {}
244
245    virtual ~PioDevice();
246
247    virtual void init();
248
249    virtual Port *getPort(const std::string &if_name, int idx = -1)
250    {
251        if (if_name == "pio") {
252            if (pioPort != NULL)
253                panic("pio port already connected to.");
254            pioPort = new PioPort(this, params()->platform);
255            return pioPort;
256        } else
257            return NULL;
258    }
259    friend class PioPort;
260
261};
262
263class BasicPioDevice : public PioDevice
264{
265  public:
266    struct Params :  public PioDevice::Params
267    {
268        Addr pio_addr;
269        Tick pio_delay;
270    };
271
272  protected:
273    /** Address that the device listens to. */
274    Addr pioAddr;
275
276    /** Size that the device's address range. */
277    Addr pioSize;
278
279    /** Delay that the device experinces on an access. */
280    Tick pioDelay;
281
282  public:
283    BasicPioDevice(Params *p)
284        : PioDevice(p), pioAddr(p->pio_addr), pioSize(0), pioDelay(p->pio_delay)
285    {}
286
287    /** return the address ranges that this device responds to.
288     * @params range_list range list to populate with ranges
289     */
290    void addressRanges(AddrRangeList &range_list);
291
292};
293
294class DmaDevice : public PioDevice
295{
296  protected:
297    DmaPort *dmaPort;
298
299  public:
300    DmaDevice(Params *p);
301    virtual ~DmaDevice();
302
303    void dmaWrite(Addr addr, int size, Event *event, uint8_t *data)
304    { dmaPort->dmaAction(Packet::WriteReq, addr, size, event, data) ; }
305
306    void dmaRead(Addr addr, int size, Event *event, uint8_t *data = NULL)
307    { dmaPort->dmaAction(Packet::ReadReq, addr, size, event, data); }
308
309    bool dmaPending() { return dmaPort->dmaPending(); }
310
311    virtual Port *getPort(const std::string &if_name, int idx = -1)
312    {
313        if (if_name == "pio") {
314            if (pioPort != NULL)
315                panic("pio port already connected to.");
316            pioPort = new PioPort(this, params()->platform);
317            return pioPort;
318        } else if (if_name == "dma") {
319            if (dmaPort != NULL)
320                panic("dma port already connected to.");
321            dmaPort = new DmaPort(this, params()->platform);
322            return dmaPort;
323        } else
324            return NULL;
325    }
326
327    friend class DmaPort;
328};
329
330
331#endif // __DEV_IO_DEVICE_HH__
332