io_device.hh revision 5386:5614618f4027 
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/fast_alloc.hh"
36#include "mem/mem_object.hh"
37#include "mem/packet.hh"
38#include "mem/tport.hh"
39#include "params/BasicPioDevice.hh"
40#include "params/DmaDevice.hh"
41#include "params/PioDevice.hh"
42#include "sim/sim_object.hh"
43
44class Event;
45class Platform;
46class PioDevice;
47class DmaDevice;
48class System;
49
50/**
51 * The PioPort class is a programmed i/o port that all devices that are
52 * sensitive to an address range use. The port takes all the memory
53 * access types and roles them into one read() and write() call that the device
54 * must respond to. The device must also provide the addressRanges() function
55 * with which it returns the address ranges it is interested in.
56 */
57class PioPort : public SimpleTimingPort
58{
59  protected:
60    /** The device that this port serves. */
61    PioDevice *device;
62
63    virtual Tick recvAtomic(PacketPtr pkt);
64
65    virtual void getDeviceAddressRanges(AddrRangeList &resp,
66                                        bool &snoop);
67
68  public:
69
70    PioPort(PioDevice *dev, System *s, std::string pname = "-pioport");
71};
72
73
74class DmaPort : public Port
75{
76  protected:
77    struct DmaReqState : public Packet::SenderState, public FastAlloc
78    {
79        /** Event to call on the device when this transaction (all packets)
80         * complete. */
81        Event *completionEvent;
82
83        /** Where we came from for some sanity checking. */
84        Port *outPort;
85
86        /** Total number of bytes that this transaction involves. */
87        Addr totBytes;
88
89        /** Number of bytes that have been acked for this transaction. */
90        Addr numBytes;
91
92        DmaReqState(Event *ce, Port *p, Addr tb)
93            : completionEvent(ce), outPort(p), totBytes(tb), numBytes(0)
94        {}
95    };
96
97    DmaDevice *device;
98    std::list<PacketPtr> transmitList;
99
100    /** The system that device/port are in. This is used to select which mode
101     * we are currently operating in. */
102    System *sys;
103
104    /** Number of outstanding packets the dma port has. */
105    int pendingCount;
106
107    /** If a dmaAction is in progress. */
108    int actionInProgress;
109
110    /** If we need to drain, keep the drain event around until we're done
111     * here.*/
112    Event *drainEvent;
113
114    /** time to wait between sending another packet, increases as NACKs are
115     * recived, decreases as responses are recived. */
116    Tick backoffTime;
117
118    /** If the port is currently waiting for a retry before it can send whatever
119     * it is that it's sending. */
120    bool inRetry;
121
122    virtual bool recvTiming(PacketPtr pkt);
123    virtual Tick recvAtomic(PacketPtr pkt)
124    { panic("dma port shouldn't be used for pio access."); M5_DUMMY_RETURN }
125    virtual void recvFunctional(PacketPtr pkt)
126    { panic("dma port shouldn't be used for pio access."); }
127
128    virtual void recvStatusChange(Status status)
129    { ; }
130
131    virtual void recvRetry() ;
132
133    virtual void getDeviceAddressRanges(AddrRangeList &resp,
134                                        bool &snoop)
135    { resp.clear(); snoop = false; }
136
137    void queueDma(PacketPtr pkt, bool front = false);
138    void sendDma();
139
140    /** event to give us a kick every time we backoff time is reached. */
141    EventWrapper<DmaPort, &DmaPort::sendDma> backoffEvent;
142
143  public:
144    DmaPort(DmaDevice *dev, System *s);
145
146    void dmaAction(Packet::Command cmd, Addr addr, int size, Event *event,
147                   uint8_t *data = NULL);
148
149    bool dmaPending() { return pendingCount > 0; }
150
151    int cacheBlockSize() { return peerBlockSize(); }
152    unsigned int drain(Event *de);
153};
154
155/**
156 * This device is the base class which all devices senstive to an address range
157 * inherit from. There are three pure virtual functions which all devices must
158 * implement addressRanges(), read(), and write(). The magic do choose which
159 * mode we are in, etc is handled by the PioPort so the device doesn't have to
160 * bother.
161 */
162class PioDevice : public MemObject
163{
164  protected:
165
166    /** The platform we are in. This is used to decide what type of memory
167     * transaction we should perform. */
168    Platform *platform;
169
170    System *sys;
171
172    /** The pioPort that handles the requests for us and provides us requests
173     * that it sees. */
174    PioPort *pioPort;
175
176    virtual void addressRanges(AddrRangeList &range_list) = 0;
177
178    /** Pure virtual function that the device must implement. Called
179     * when a read command is recieved by the port.
180     * @param pkt Packet describing this request
181     * @return number of ticks it took to complete
182     */
183    virtual Tick read(PacketPtr pkt) = 0;
184
185    /** Pure virtual function that the device must implement. Called when a
186     * write command is recieved by the port.
187     * @param pkt Packet describing this request
188     * @return number of ticks it took to complete
189     */
190    virtual Tick write(PacketPtr pkt) = 0;
191
192  public:
193    typedef PioDeviceParams Params;
194    PioDevice(const Params *p);
195    virtual ~PioDevice();
196
197    const Params *
198    params() const
199    {
200        return dynamic_cast<const Params *>(_params);
201    }
202
203    virtual void init();
204
205    virtual unsigned int drain(Event *de);
206
207    virtual Port *getPort(const std::string &if_name, int idx = -1)
208    {
209        if (if_name == "pio") {
210            if (pioPort != NULL)
211                panic("pio port already connected to.");
212            pioPort = new PioPort(this, sys);
213            return pioPort;
214        } else
215            return NULL;
216    }
217    friend class PioPort;
218
219};
220
221class BasicPioDevice : public PioDevice
222{
223  protected:
224    /** Address that the device listens to. */
225    Addr pioAddr;
226
227    /** Size that the device's address range. */
228    Addr pioSize;
229
230    /** Delay that the device experinces on an access. */
231    Tick pioDelay;
232
233  public:
234    typedef BasicPioDeviceParams Params;
235    BasicPioDevice(const Params *p);
236
237    const Params *
238    params() const
239    {
240        return dynamic_cast<const Params *>(_params);
241    }
242
243    /** return the address ranges that this device responds to.
244     * @param range_list range list to populate with ranges
245     */
246    void addressRanges(AddrRangeList &range_list);
247
248};
249
250class DmaDevice : public PioDevice
251{
252   protected:
253    DmaPort *dmaPort;
254    Tick minBackoffDelay;
255    Tick maxBackoffDelay;
256
257  public:
258    typedef DmaDeviceParams Params;
259    DmaDevice(const Params *p);
260    virtual ~DmaDevice();
261
262    const Params *
263    params() const
264    {
265        return dynamic_cast<const Params *>(_params);
266    }
267
268    void dmaWrite(Addr addr, int size, Event *event, uint8_t *data)
269    {
270        dmaPort->dmaAction(MemCmd::WriteReq, addr, size, event, data);
271    }
272
273    void dmaRead(Addr addr, int size, Event *event, uint8_t *data)
274    {
275        dmaPort->dmaAction(MemCmd::ReadReq, addr, size, event, data);
276    }
277
278    bool dmaPending() { return dmaPort->dmaPending(); }
279
280    virtual unsigned int drain(Event *de);
281
282    int cacheBlockSize() { return dmaPort->cacheBlockSize(); }
283
284    virtual Port *getPort(const std::string &if_name, int idx = -1)
285    {
286        if (if_name == "pio") {
287            if (pioPort != NULL)
288                panic("pio port already connected to.");
289            pioPort = new PioPort(this, sys);
290            return pioPort;
291        } else if (if_name == "dma") {
292            if (dmaPort != NULL)
293                panic("dma port already connected to.");
294            dmaPort = new DmaPort(this, sys);
295            return dmaPort;
296        } else
297            return NULL;
298    }
299
300    friend class DmaPort;
301};
302
303
304#endif // __DEV_IO_DEVICE_HH__
305