io_device.hh revision 5732:1a24f9a28729 
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        /** Amount to delay completion of dma by */
93        Tick delay;
94
95        DmaReqState(Event *ce, Port *p, Addr tb, Tick _delay)
96            : completionEvent(ce), outPort(p), totBytes(tb), numBytes(0),
97              delay(_delay)
98        {}
99    };
100
101    DmaDevice *device;
102    std::list<PacketPtr> transmitList;
103
104    /** The system that device/port are in. This is used to select which mode
105     * we are currently operating in. */
106    System *sys;
107
108    /** Number of outstanding packets the dma port has. */
109    int pendingCount;
110
111    /** If a dmaAction is in progress. */
112    int actionInProgress;
113
114    /** If we need to drain, keep the drain event around until we're done
115     * here.*/
116    Event *drainEvent;
117
118    /** time to wait between sending another packet, increases as NACKs are
119     * recived, decreases as responses are recived. */
120    Tick backoffTime;
121
122    /** If the port is currently waiting for a retry before it can send whatever
123     * it is that it's sending. */
124    bool inRetry;
125
126    virtual bool recvTiming(PacketPtr pkt);
127    virtual Tick recvAtomic(PacketPtr pkt)
128    { panic("dma port shouldn't be used for pio access."); M5_DUMMY_RETURN }
129    virtual void recvFunctional(PacketPtr pkt)
130    { panic("dma port shouldn't be used for pio access."); }
131
132    virtual void recvStatusChange(Status status)
133    { ; }
134
135    virtual void recvRetry() ;
136
137    virtual void getDeviceAddressRanges(AddrRangeList &resp,
138                                        bool &snoop)
139    { resp.clear(); snoop = false; }
140
141    void queueDma(PacketPtr pkt, bool front = false);
142    void sendDma();
143
144    /** event to give us a kick every time we backoff time is reached. */
145    EventWrapper<DmaPort, &DmaPort::sendDma> backoffEvent;
146
147  public:
148    DmaPort(DmaDevice *dev, System *s);
149
150    void dmaAction(Packet::Command cmd, Addr addr, int size, Event *event,
151                   uint8_t *data, Tick delay);
152
153    bool dmaPending() { return pendingCount > 0; }
154
155    int cacheBlockSize() { return peerBlockSize(); }
156    unsigned int drain(Event *de);
157};
158
159/**
160 * This device is the base class which all devices senstive to an address range
161 * inherit from. There are three pure virtual functions which all devices must
162 * implement addressRanges(), read(), and write(). The magic do choose which
163 * mode we are in, etc is handled by the PioPort so the device doesn't have to
164 * bother.
165 */
166class PioDevice : public MemObject
167{
168  protected:
169
170    /** The platform we are in. This is used to decide what type of memory
171     * transaction we should perform. */
172    Platform *platform;
173
174    System *sys;
175
176    /** The pioPort that handles the requests for us and provides us requests
177     * that it sees. */
178    PioPort *pioPort;
179
180    virtual void addressRanges(AddrRangeList &range_list) = 0;
181
182    /** Pure virtual function that the device must implement. Called
183     * when a read command is recieved by the port.
184     * @param pkt Packet describing this request
185     * @return number of ticks it took to complete
186     */
187    virtual Tick read(PacketPtr pkt) = 0;
188
189    /** Pure virtual function that the device must implement. Called when a
190     * write command is recieved by the port.
191     * @param pkt Packet describing this request
192     * @return number of ticks it took to complete
193     */
194    virtual Tick write(PacketPtr pkt) = 0;
195
196  public:
197    typedef PioDeviceParams Params;
198    PioDevice(const Params *p);
199    virtual ~PioDevice();
200
201    const Params *
202    params() const
203    {
204        return dynamic_cast<const Params *>(_params);
205    }
206
207    virtual void init();
208
209    virtual unsigned int drain(Event *de);
210
211    virtual Port *getPort(const std::string &if_name, int idx = -1)
212    {
213        if (if_name == "pio") {
214            if (pioPort != NULL)
215                fatal("%s: pio port already connected to %s",
216                      name(), pioPort->getPeer()->name());
217            pioPort = new PioPort(this, sys);
218            return pioPort;
219        } else
220            return NULL;
221    }
222    friend class PioPort;
223
224};
225
226class BasicPioDevice : public PioDevice
227{
228  protected:
229    /** Address that the device listens to. */
230    Addr pioAddr;
231
232    /** Size that the device's address range. */
233    Addr pioSize;
234
235    /** Delay that the device experinces on an access. */
236    Tick pioDelay;
237
238  public:
239    typedef BasicPioDeviceParams Params;
240    BasicPioDevice(const Params *p);
241
242    const Params *
243    params() const
244    {
245        return dynamic_cast<const Params *>(_params);
246    }
247
248    /** return the address ranges that this device responds to.
249     * @param range_list range list to populate with ranges
250     */
251    void addressRanges(AddrRangeList &range_list);
252
253};
254
255class DmaDevice : public PioDevice
256{
257   protected:
258    DmaPort *dmaPort;
259    Tick minBackoffDelay;
260    Tick maxBackoffDelay;
261
262  public:
263    typedef DmaDeviceParams Params;
264    DmaDevice(const Params *p);
265    virtual ~DmaDevice();
266
267    const Params *
268    params() const
269    {
270        return dynamic_cast<const Params *>(_params);
271    }
272
273    void dmaWrite(Addr addr, int size, Event *event, uint8_t *data, Tick delay = 0)
274    {
275        dmaPort->dmaAction(MemCmd::WriteReq, addr, size, event, data, delay);
276    }
277
278    void dmaRead(Addr addr, int size, Event *event, uint8_t *data, Tick delay = 0)
279    {
280        dmaPort->dmaAction(MemCmd::ReadReq, addr, size, event, data, delay);
281    }
282
283    bool dmaPending() { return dmaPort->dmaPending(); }
284
285    virtual unsigned int drain(Event *de);
286
287    int cacheBlockSize() { return dmaPort->cacheBlockSize(); }
288
289    virtual Port *getPort(const std::string &if_name, int idx = -1)
290    {
291        if (if_name == "pio") {
292            if (pioPort != NULL)
293                fatal("%s: pio port already connected to %s",
294                      name(), pioPort->getPeer()->name());
295            pioPort = new PioPort(this, sys);
296            return pioPort;
297        } else if (if_name == "dma") {
298            if (dmaPort != NULL)
299                fatal("%s: dma port already connected to %s",
300                      name(), dmaPort->getPeer()->name());
301            dmaPort = new DmaPort(this, sys);
302            return dmaPort;
303        } else
304            return NULL;
305    }
306
307    friend class DmaPort;
308};
309
310
311#endif // __DEV_IO_DEVICE_HH__
312