io_device.hh revision 2901 
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 system that device/port are in. This is used to select which mode
64     * we are currently operating in. */
65    System *sys;
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    /** Number of timing requests that are emulating the device timing before
110     * attempting to end up on the bus.
111     */
112    int outTiming;
113
114    /** If we need to drain, keep the drain event around until we're done
115     * here.*/
116    Event *drainEvent;
117
118    /** Schedule a sendTiming() event to be called in the future. */
119    void sendTiming(Packet *pkt, Tick time)
120    { outTiming++; new PioPort::SendEvent(this, pkt, time); }
121
122    /** This function is notification that the device should attempt to send a
123     * packet again. */
124    virtual void recvRetry();
125
126  public:
127    PioPort(PioDevice *dev, System *s, std::string pname = "-pioport");
128
129    unsigned int drain(Event *de);
130
131  friend class PioPort::SendEvent;
132};
133
134
135class DmaPort : public Port
136{
137  protected:
138    struct DmaReqState : public Packet::SenderState
139    {
140        /** Event to call on the device when this transaction (all packets)
141         * complete. */
142        Event *completionEvent;
143
144        /** Where we came from for some sanity checking. */
145        Port *outPort;
146
147        /** Total number of bytes that this transaction involves. */
148        Addr totBytes;
149
150        /** Number of bytes that have been acked for this transaction. */
151        Addr numBytes;
152
153        DmaReqState(Event *ce, Port *p, Addr tb)
154            : completionEvent(ce), outPort(p), totBytes(tb), numBytes(0)
155        {}
156    };
157
158    DmaDevice *device;
159    std::list<Packet*> transmitList;
160
161    /** The system that device/port are in. This is used to select which mode
162     * we are currently operating in. */
163    System *sys;
164
165    /** Number of outstanding packets the dma port has. */
166    int pendingCount;
167
168    /** If a dmaAction is in progress. */
169    int actionInProgress;
170
171    /** If we need to drain, keep the drain event around until we're done
172     * here.*/
173    Event *drainEvent;
174
175    virtual bool recvTiming(Packet *pkt);
176    virtual Tick recvAtomic(Packet *pkt)
177    { panic("dma port shouldn't be used for pio access."); }
178    virtual void recvFunctional(Packet *pkt)
179    { panic("dma port shouldn't be used for pio access."); }
180
181    virtual void recvStatusChange(Status status)
182    { ; }
183
184    virtual void recvRetry() ;
185
186    virtual void getDeviceAddressRanges(AddrRangeList &resp, AddrRangeList &snoop)
187    { resp.clear(); snoop.clear(); }
188
189    void sendDma(Packet *pkt, bool front = false);
190
191  public:
192    DmaPort(DmaDevice *dev, System *s);
193
194    void dmaAction(Packet::Command cmd, Addr addr, int size, Event *event,
195                   uint8_t *data = NULL);
196
197    bool dmaPending() { return pendingCount > 0; }
198
199    unsigned int drain(Event *de);
200};
201
202/**
203 * This device is the base class which all devices senstive to an address range
204 * inherit from. There are three pure virtual functions which all devices must
205 * implement addressRanges(), read(), and write(). The magic do choose which
206 * mode we are in, etc is handled by the PioPort so the device doesn't have to
207 * bother.
208 */
209
210class PioDevice : public MemObject
211{
212  protected:
213
214    /** The platform we are in. This is used to decide what type of memory
215     * transaction we should perform. */
216    Platform *platform;
217
218    System *sys;
219
220    /** The pioPort that handles the requests for us and provides us requests
221     * that it sees. */
222    PioPort *pioPort;
223
224    virtual void addressRanges(AddrRangeList &range_list) = 0;
225
226    /** As far as the devices are concerned they only accept atomic transactions
227     * which are converted to either a write or a read. */
228    Tick recvAtomic(Packet *pkt)
229    { return pkt->isRead() ? this->read(pkt) : this->write(pkt); }
230
231    /** Pure virtual function that the device must implement. Called when a read
232     * command is recieved by the port.
233     * @param pkt Packet describing this request
234     * @return number of ticks it took to complete
235     */
236    virtual Tick read(Packet *pkt) = 0;
237
238    /** Pure virtual function that the device must implement. Called when a
239     * write command is recieved by the port.
240     * @param pkt Packet describing this request
241     * @return number of ticks it took to complete
242     */
243    virtual Tick write(Packet *pkt) = 0;
244
245  public:
246    /** Params struct which is extended through each device based on the
247     * parameters it needs. Since we are re-writing everything, we might as well
248     * start from the bottom this time. */
249
250    struct Params
251    {
252        std::string name;
253        Platform *platform;
254        System *system;
255    };
256
257  protected:
258    Params *_params;
259
260  public:
261    const Params *params() const { return _params; }
262
263    PioDevice(Params *p)
264              : MemObject(p->name),  platform(p->platform), sys(p->system),
265              pioPort(NULL), _params(p)
266              {}
267
268    virtual ~PioDevice();
269
270    virtual void init();
271
272    virtual unsigned int drain(Event *de);
273
274    virtual Port *getPort(const std::string &if_name, int idx = -1)
275    {
276        if (if_name == "pio") {
277            if (pioPort != NULL)
278                panic("pio port already connected to.");
279            pioPort = new PioPort(this, sys);
280            return pioPort;
281        } else
282            return NULL;
283    }
284    friend class PioPort;
285
286};
287
288class BasicPioDevice : public PioDevice
289{
290  public:
291    struct Params :  public PioDevice::Params
292    {
293        Addr pio_addr;
294        Tick pio_delay;
295    };
296
297  protected:
298    /** Address that the device listens to. */
299    Addr pioAddr;
300
301    /** Size that the device's address range. */
302    Addr pioSize;
303
304    /** Delay that the device experinces on an access. */
305    Tick pioDelay;
306
307  public:
308    BasicPioDevice(Params *p)
309        : PioDevice(p), pioAddr(p->pio_addr), pioSize(0), pioDelay(p->pio_delay)
310    {}
311
312    /** return the address ranges that this device responds to.
313     * @params range_list range list to populate with ranges
314     */
315    void addressRanges(AddrRangeList &range_list);
316
317};
318
319class DmaDevice : public PioDevice
320{
321  protected:
322    DmaPort *dmaPort;
323
324  public:
325    DmaDevice(Params *p);
326    virtual ~DmaDevice();
327
328    void dmaWrite(Addr addr, int size, Event *event, uint8_t *data)
329    { dmaPort->dmaAction(Packet::WriteReq, addr, size, event, data) ; }
330
331    void dmaRead(Addr addr, int size, Event *event, uint8_t *data = NULL)
332    { dmaPort->dmaAction(Packet::ReadReq, addr, size, event, data); }
333
334    bool dmaPending() { return dmaPort->dmaPending(); }
335
336    virtual unsigned int drain(Event *de);
337
338    virtual Port *getPort(const std::string &if_name, int idx = -1)
339    {
340        if (if_name == "pio") {
341            if (pioPort != NULL)
342                panic("pio port already connected to.");
343            pioPort = new PioPort(this, sys);
344            return pioPort;
345        } else if (if_name == "dma") {
346            if (dmaPort != NULL)
347                panic("dma port already connected to.");
348            dmaPort = new DmaPort(this, sys);
349            return dmaPort;
350        } else
351            return NULL;
352    }
353
354    friend class DmaPort;
355};
356
357
358#endif // __DEV_IO_DEVICE_HH__
359